1
|
Ross CA, Phillips AK, Gospodyn L, Oswald CJ, Wellen CC, Sorichetti RJ. Improving the representation of stream water sources in surrogate nutrient models with water isotope data. Sci Total Environ 2023:164544. [PMID: 37270007 DOI: 10.1016/j.scitotenv.2023.164544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 05/01/2023] [Accepted: 05/27/2023] [Indexed: 06/05/2023]
Abstract
An important part of meeting nutrient reduction goals in the lower Great Lakes basin and assessing the success of different land management strategies is modeling nutrient losses from agricultural land. This study aimed to improve the representation of water source contributions to streamflow in generalized additive models for predicting nutrient fluxes from three headwater agricultural streams in southern Ontario monitored during the Multi-Watershed Nutrient Study (MWNS). The previous development of these models represented baseflow contributions to streamflow using the baseflow proportion derived using an uncalibrated recursive digital filter. Recursive digital filters are commonly used to partition stream discharge into separate components from slower and faster pathways. In this study, we calibrated the recursive digital filter using stream water source information from stable isotopes of oxygen in water. Across sites, optimization of the filter parameters reduced bias in baseflow estimates by as much as 68 %. In most cases, calibrating the filter also improved agreement between filter-derived baseflow and baseflow calculated from isotope and streamflow data: the average Kling-Gupta Efficiencies using default and calibrated parameters were 0.44 and 0.82, respectively. When incorporated into the generalized additive models, the revised baseflow proportion predictor was more often statistically significant, improved model parsimony, and reduced prediction uncertainty. Moreover, this information allowed for a more rigorous interpretation of how different stream water sources influence nutrient losses from the agricultural MWNS watersheds.
Collapse
Affiliation(s)
- C A Ross
- Department of Geography and Environmental Studies, Toronto Metropolitan University, Toronto, Canada.
| | - A K Phillips
- Department of Geography and Environmental Studies, Toronto Metropolitan University, Toronto, Canada
| | - L Gospodyn
- Department of Geography and Environmental Management, University of Waterloo, Waterloo, Canada
| | - C J Oswald
- Department of Geography and Environmental Studies, Toronto Metropolitan University, Toronto, Canada
| | - C C Wellen
- Department of Geography and Environmental Studies, Toronto Metropolitan University, Toronto, Canada
| | - R J Sorichetti
- Ontario Ministry of the Environment, Conservation and Parks, Toronto, Canada
| |
Collapse
|
2
|
Ross CA, Moslenko LL, Biagi KM, Oswald CJ, Wellen CC, Thomas JL, Raby M, Sorichetti RJ. Total and dissolved phosphorus losses from agricultural headwater streams during extreme runoff events. Sci Total Environ 2022; 848:157736. [PMID: 35926630 DOI: 10.1016/j.scitotenv.2022.157736] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 07/17/2022] [Accepted: 07/27/2022] [Indexed: 06/15/2023]
Abstract
Eutrophication continues to be a concerning global water quality issue. Managing and mitigating harmful algal blooms demands clear information on the conditions promoting large phosphorus losses from contributing watersheds. Of particular concern is the amount and form of phosphorus loading to receiving water bodies during extreme runoff events, which are expected to increase in frequency due to climate change. Five years (2015 to 2020) of water quantity and quality data from 11 agricultural watersheds in the lower Great Lakes basin were analyzed and used to model total and dissolved phosphorus losses. This study aimed to assess temporal dynamics in phosphorus concentrations and losses over runoff events covering a wide range of hydrologic conditions and to quantify their relative importance on annual phosphorus losses. Event concentration-discharge relationships for total and dissolved phosphorus were hysteretic and had contrasting dominant patterns across watersheds. The proportion of annual phosphorus losses during events was highly variable between watersheds, accounting for 47-94 %. Extreme events were particularly impactful: as few as three events per year were found to be responsible for nearly half of total phosphorus (20-50 %) and total dissolved phosphorus (14-44 %) losses. Variability in total and dissolved phosphorus losses and concentrations over a wide range of flow conditions suggests that event magnitude is an important control on the relative mobility of particulate and dissolved phosphorus fractions. This study showed that insights into nutrient dynamics and phosphorus budgets in the lower Great Lakes basin and agriculture dominated environments more broadly can be gained by assessing event nutrient losses with respect to flow conditions and patterns in concentration-discharge relationships.
Collapse
Affiliation(s)
- C A Ross
- Department of Geography and Environmental Studies, Toronto Metropolitan University, 350 Victoria St, Toronto M5B 2K3, Canada.
| | - L L Moslenko
- Department of Geography and Environmental Studies, Toronto Metropolitan University, 350 Victoria St, Toronto M5B 2K3, Canada
| | - K M Biagi
- Department of Geography and Environmental Studies, Toronto Metropolitan University, 350 Victoria St, Toronto M5B 2K3, Canada
| | - C J Oswald
- Department of Geography and Environmental Studies, Toronto Metropolitan University, 350 Victoria St, Toronto M5B 2K3, Canada
| | - C C Wellen
- Department of Geography and Environmental Studies, Toronto Metropolitan University, 350 Victoria St, Toronto M5B 2K3, Canada
| | - J L Thomas
- Ontario Ministry of the Environment, Conservation and Parks, 125 Resources Rd, Toronto M9P 3V6, Canada
| | - M Raby
- Ontario Ministry of the Environment, Conservation and Parks, 125 Resources Rd, Toronto M9P 3V6, Canada
| | - R J Sorichetti
- Ontario Ministry of the Environment, Conservation and Parks, 125 Resources Rd, Toronto M9P 3V6, Canada
| |
Collapse
|
3
|
Biagi KM, Ross CA, Oswald CJ, Sorichetti RJ, Thomas JL, Wellen CC. Novel predictors related to hysteresis and baseflow improve predictions of watershed nutrient loads: An example from Ontario's lower Great Lakes basin. Sci Total Environ 2022; 826:154023. [PMID: 35202681 DOI: 10.1016/j.scitotenv.2022.154023] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 01/13/2022] [Accepted: 02/16/2022] [Indexed: 06/14/2023]
Abstract
Eutrophication has re-emerged in the lower Great Lakes basin resulting in critical water quality issues. Models that accurately predict nutrient loading from streams are needed to inform appropriate nutrient management decisions. Generalized additive models (GAMs) that use surrogate data from sensors to predict nutrient loads offer an alternative to commonly applied linear regression and may better handle relationship non-linearities and skewed water quality data. Five years (2015-2020) of water quantity and quality data from 11 agricultural watersheds in southern Ontario were used to develop GAMs to predict total phosphorus (TP) and nitrate (NO3-) loads. This study aimed to 1) use GAMs to predict nutrient loads using both common and novel predictors and 2) quantify and examine the variability in seasonal and annual nutrient loads. Along with routine surrogate model predictors (i.e., flow, turbidity, and seasonality), the addition of the baseflow proportion and the hydrograph position of flow observations improved model performance. Conversely, including the antecedent precipitation index minimally affected model performance, regardless of constituent. Seasonal and annual patterns in TP and NO3- load predictions mirrored that of the hydrologic regime. This study showed that parsimonious GAMs featuring novel model predictors can be used to predict nutrient loads while accounting for the partitioning of surface and subsurface flow paths and hysteresis between streamflow and water quality parameters that are frequently observed in a wide range of environments.
Collapse
Affiliation(s)
- K M Biagi
- Department of Geography and Environmental Studies, Ryerson University, 350 Victoria St, Toronto M5B 2K3, Canada
| | - C A Ross
- Department of Geography and Environmental Studies, Ryerson University, 350 Victoria St, Toronto M5B 2K3, Canada.
| | - C J Oswald
- Department of Geography and Environmental Studies, Ryerson University, 350 Victoria St, Toronto M5B 2K3, Canada
| | - R J Sorichetti
- Ontario Ministry of the Environment, Conservation and Parks, 125 Resources Rd, Toronto M9P 3V6, Canada
| | - J L Thomas
- Ontario Ministry of the Environment, Conservation and Parks, 125 Resources Rd, Toronto M9P 3V6, Canada
| | - C C Wellen
- Department of Geography and Environmental Studies, Ryerson University, 350 Victoria St, Toronto M5B 2K3, Canada
| |
Collapse
|
4
|
|
5
|
Cheng LC, Bai W, Fernandez Martin E, Tu KH, Ntetsikas K, Liontos G, Avgeropoulos A, Ross CA. Morphology, directed self-assembly and pattern transfer from a high molecular weight polystyrene-block-poly(dimethylsiloxane) block copolymer film. Nanotechnology 2017; 28:145301. [PMID: 28221161 DOI: 10.1088/1361-6528/aa61c9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The self-assembly of block copolymers with large feature sizes is inherently challenging as the large kinetic barrier arising from chain entanglement of high molecular weight (MW) polymers limits the extent over which long-range ordered microdomains can be achieved. Here, we illustrate the evolution of thin film morphology from a diblock copolymer of polystyrene-block-poly(dimethylsiloxane) exhibiting total number average MW of 123 kg mol-1, and demonstrate the formation of layers of well-ordered cylindrical microdomains under appropriate conditions of binary solvent mix ratio, commensurate film thickness, and solvent vapor annealing time. Directed self-assembly of the block copolymer within lithographically patterned trenches occurs with alignment of cylinders parallel to the sidewalls. Fabrication of ordered cobalt nanowire arrays by pattern transfer was also implemented, and their magnetic properties and domain wall behavior were characterized.
Collapse
Affiliation(s)
- Li-Chen Cheng
- Department of Materials Science and Engineering, MIT, Cambridge MA 02139, United States of America
| | | | | | | | | | | | | | | |
Collapse
|
6
|
Kubota Y, Murata K, Miyawaki J, Ozawa K, Onbasli MC, Shirasawa T, Feng B, Yamamoto S, Liu RY, Yamamoto S, Mahatha SK, Sheverdyaeva P, Moras P, Ross CA, Suga S, Harada Y, Wang KL, Matsuda I. Interface electronic structure at the topological insulator-ferrimagnetic insulator junction. J Phys Condens Matter 2017; 29:055002. [PMID: 27911879 DOI: 10.1088/1361-648x/29/5/055002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
An interface electron state at the junction between a three-dimensional topological insulator film, Bi2Se3, and a ferrimagnetic insulator film, Y3Fe5O12 (YIG), was investigated by measurements of angle-resolved photoelectron spectroscopy and x-ray absorption magnetic circular dichroism. The surface state of the Bi2Se3 film was directly observed and localized 3d spin states of the Fe3+ in the YIG film were confirmed. The proximity effect is likely described in terms of the exchange interaction between the localized Fe 3d electrons in the YIG film and delocalized electrons of the surface and bulk states in the Bi2Se3 film.
Collapse
Affiliation(s)
- Y Kubota
- Institute for Solid State Physics, The University of Tokyo, Kashiwa, Chiba 277-8581, Japan
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
7
|
Lee K, Kreider M, Bai W, Cheng LC, Dinachali SS, Tu KH, Huang T, Ntetsikas K, Liontos G, Avgeropoulos A, Ross CA. UV-solvent annealing of PDMS-majority and PS-majority PS-b-PDMS block copolymer films. Nanotechnology 2016; 27:465301. [PMID: 27736809 DOI: 10.1088/0957-4484/27/46/465301] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The response of polystyrene-block-poly(dimethylsiloxane) (PS-b-PDMS) thin films to UV exposure during solvent vapor annealing is described, in order to improve their applicability in nanolithography and nanofabrication. Two BCPs were examined, one with the PS block as majority (f PS = 68%, M n = 53 kg mol-1), the other with PDMS block as majority (f PDMS = 67%, M n = 44 kg mol-1). A 5 min UV irradiation was applied during solvent vapor annealing which led to both partial crosslinking of the polymer and a small increase in the temperature of the annealing chamber. This approach was effective for improving the correlation length of the self-assembled microdomain arrays and in limiting subsequent flow of the PDMS in the PDMS-majority BCP to preserve the post-anneal morphology. Ordering and orientation of microdomains were controlled by directed self-assembly of the BCPs in trench substrates. Highly-ordered perpendicular nanochannel arrays were obtained in the PDMS-majority BCP.
Collapse
Affiliation(s)
- Keehong Lee
- Department of Materials Science and Engineering, MIT, Cambridge MA 02139, USA. Semiconductor R&D Center, Samsung Electronics, Hwasung-City, Gyeonggi-do, Korea
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Carlozzi NE, Schilling SG, Lai JS, Paulsen JS, Hahn EA, Perlmutter JS, Ross CA, Downing NR, Kratz AL, McCormack MK, Nance MA, Quaid KA, Stout JC, Gershon RC, Ready RE, Miner JA, Barton SK, Perlman SL, Rao SM, Frank S, Shoulson I, Marin H, Geschwind MD, Dayalu P, Goodnight SM, Cella D. HDQLIFE: development and assessment of health-related quality of life in Huntington disease (HD). Qual Life Res 2016; 25:2441-2455. [PMID: 27522213 PMCID: PMC6108175 DOI: 10.1007/s11136-016-1386-3] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/03/2016] [Indexed: 11/25/2022]
Abstract
PURPOSE Huntington disease (HD) is a chronic, debilitating genetic disease that affects physical, emotional, cognitive, and social health. Existing patient-reported outcomes (PROs) of health-related quality of life (HRQOL) used in HD are neither comprehensive, nor do they adequately account for clinically meaningful changes in function. While new PROs examining HRQOL (i.e., Neuro-QoL-Quality of Life in Neurological Disorders and PROMIS-Patient-Reported Outcomes Measurement Information System) offer solutions to many of these shortcomings, they do not include HD-specific content, nor have they been validated in HD. HDQLIFE addresses this by validating 12 PROMIS/Neuro-QoL domains in individuals with HD and by using established PROMIS methodology to develop new, HD-specific content. METHODS New item pools were developed using cognitive debriefing with individuals with HD, and expert, literacy, and translatability reviews. Existing item banks and new item pools were field tested in 536 individuals with prodromal, early-, or late-stage HD. RESULTS Moderate to strong relationships between Neuro-QoL/PROMIS measures and generic self-report measures of HRQOL, and moderate relationships between Neuro-QoL/PROMIS and clinician-rated measures of similar constructs supported the validity of Neuro-QoL/PROMIS in individuals with HD. Exploratory and confirmatory factor analysis, item response theory, and differential item functioning analyses were utilized to develop new item banks for Chorea, Speech Difficulties, Swallowing Difficulties, and Concern with Death and Dying, with corresponding six-item short forms. A four-item short form was developed for Meaning and Purpose. CONCLUSIONS HDQLIFE encompasses both validated Neuro-QoL/PROMIS measures, as well as five new scales in order to provide a comprehensive assessment of HRQOL in HD.
Collapse
Affiliation(s)
- N E Carlozzi
- Department of Physical Medicine and Rehabilitation, University of Michigan, North Campus Research Complex, 2800 Plymouth Road, Building NCRC B14, Room G216, Ann Arbor, MI, 48109-2800, USA.
| | - S G Schilling
- Department of Physical Medicine and Rehabilitation, University of Michigan, North Campus Research Complex, 2800 Plymouth Road, Building NCRC B14, Room G216, Ann Arbor, MI, 48109-2800, USA
- Institute for Social Research, University of Michigan, Ann Arbor, MI, USA
| | - J-S Lai
- Department of Medical Social Sciences, Northwestern University, Chicago, IL, USA
| | - J S Paulsen
- Department of Psychiatry, Carver College of Medicine, The University of Iowa, Iowa City, IA, USA
- Department of Neurology, Carver College of Medicine, The University of Iowa, Iowa City, IA, USA
- Department of Psychology, The University of Iowa, Iowa City, IA, USA
| | - E A Hahn
- Department of Medical Social Sciences, Northwestern University, Chicago, IL, USA
| | - J S Perlmutter
- Departments of Neurology, Radiology, and Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, MO, USA
- Program in Occupational Therapy and Program in Physical Therapy, Washington University School of Medicine, St. Louis, MO, USA
| | - C A Ross
- Departments of Psychiatry, Neurology, Pharmacology and Neuroscience, Johns Hopkins University, Baltimore, MD, USA
| | - N R Downing
- College of Nursing, The University of Iowa, Iowa City, IA, USA
| | - A L Kratz
- Department of Physical Medicine and Rehabilitation, University of Michigan, North Campus Research Complex, 2800 Plymouth Road, Building NCRC B14, Room G216, Ann Arbor, MI, 48109-2800, USA
| | - M K McCormack
- Department of Pathology, Rowan University, Piscataway, NJ, USA
| | - M A Nance
- Struthers Parkinson's Center, Golden Valley, MN, USA
- Hennepin County Medical Center, Minneapolis, MN, USA
| | - K A Quaid
- Department of Medical and Molecular Genetics, Indiana University, Indianapolis, IN, USA
| | - J C Stout
- School of Psychological Sciences, Monash University, Clayton, VIC, Australia
| | - R C Gershon
- Department of Medical Social Sciences, Northwestern University, Chicago, IL, USA
- Department of Preventative Medicine, Northwestern University, Evanston, IL, USA
| | - R E Ready
- Department of Psychological and Brain Sciences, University of Massachusetts, Amherst, MA, USA
| | - J A Miner
- Department of Physical Medicine and Rehabilitation, University of Michigan, North Campus Research Complex, 2800 Plymouth Road, Building NCRC B14, Room G216, Ann Arbor, MI, 48109-2800, USA
| | - S K Barton
- Departments of Neurology, Radiology, and Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, MO, USA
| | - S L Perlman
- Department of Neurology, David Geffen School of Medicine, UCLA, Los Angeles, CA, USA
| | - S M Rao
- Department of Psychiatry and Psychology, Cleveland Clinic, Cleveland, OH, USA
| | - S Frank
- Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - I Shoulson
- Department of Neurology, Georgetown University, Washington, DC, USA
| | - H Marin
- Department of Psychiatry, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, USA
| | - M D Geschwind
- Memory and Aging Center, UCSF, San Francisco, CA, USA
| | - P Dayalu
- Department of Neurology, University of Michigan, Ann Arbor, MI, USA
| | - S M Goodnight
- Department of Physical Medicine and Rehabilitation, University of Michigan, North Campus Research Complex, 2800 Plymouth Road, Building NCRC B14, Room G216, Ann Arbor, MI, 48109-2800, USA
| | - D Cella
- Department of Medical Social Sciences, Northwestern University, Chicago, IL, USA
| |
Collapse
|
9
|
Biglan KM, Dorsey ER, Evans RVV, Ross CA, Hersch S, Shoulson I, Matson W, Kieburtz K. Plasma 8-hydroxy-2'-deoxyguanosine Levels in Huntington Disease and Healthy Controls Treated with Coenzyme Q10. J Huntingtons Dis 2016; 1:65-9. [PMID: 25063191 DOI: 10.3233/jhd-2012-120007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
We analyzed plasma 8OHdG concentrations in 20 individuals enrolled in the Pre-2CARE study before and after treatment with CoQ. Treatment resulted in a mean reduction in 8OHdG of 2.9 ± 2.9 pg/ml for the cohort (p = 0.0003) and 3.0 ± 2.6 pg/ml, for the HD group (p = 0.002). Baseline 8OHdG levels were not different between individuals with HD and controls (19.3 ± 3.2 pg/ml vs. 19.5 ± 4.7 pg/ml, p = 0.87) though baseline CoQ levels were elevated in HD compared with controls (p < 0.001). CoQ treatment reduces plasma 8OHdG and this reduction may serve as a marker of pharmacologic activity of CoQ in HD.
Collapse
Affiliation(s)
- K M Biglan
- Department of Neurology, University of Rochester Medical Center, Rochester, NY, USA.
| | - E R Dorsey
- Department of Neurology, University of Rochester Medical Center, Rochester, NY, USA Department of Neurology, Johns Hopkins University, Baltimore, MD, USA
| | - R V V Evans
- Department of Neurology, University of Rochester Medical Center, Rochester, NY, USA
| | - C A Ross
- Departments of Psychiatry, Neurology, Neuroscience and Pharmacology, Johns Hopkins University, Baltimore, MD, USA
| | - S Hersch
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - I Shoulson
- Department of Neurology, University of Rochester Medical Center, Rochester, NY, USA Department of Neurology, Georgetown University, Washington, D.C., USA
| | - W Matson
- Boston University School of Medicine, Boston, MA, USA
| | - K Kieburtz
- Department of Neurology, University of Rochester Medical Center, Rochester, NY, USA
| | | |
Collapse
|
10
|
van Bergen JMG, Hua J, Unschuld PG, Lim IAL, Jones CK, Margolis RL, Ross CA, van Zijl PCM, Li X. Quantitative Susceptibility Mapping Suggests Altered Brain Iron in Premanifest Huntington Disease. AJNR Am J Neuroradiol 2016; 37:789-96. [PMID: 26680466 DOI: 10.3174/ajnr.a4617] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Accepted: 09/22/2015] [Indexed: 12/27/2022]
Abstract
BACKGROUND AND PURPOSE In patients with premanifest (nonsymptomatic) and advanced Huntington disease, changes in brain iron levels in the basal ganglia have been previously reported, especially in the striatum. Quantitative susceptibility mapping by using MR phase imaging allows in vivo measurements of tissue magnetic susceptibility, which has been shown to correlate well with iron levels in brain gray matter and is believed to be more specific than other imaging-based iron measures. The purpose of this study was to investigate the use of magnetic susceptibility as a biomarker of disease progression. MATERIALS AND METHODS Fifteen subjects with premanifest Huntington disease and 16 age-matched healthy controls were scanned at 7T. Magnetic susceptibility, effective relaxation, and tissue volume in deep gray matter structures were quantified and compared with genetic and clinical measures. RESULTS Subjects with premanifest Huntington disease showed significantly higher susceptibility values in the caudate nucleus, putamen, and globus pallidus, indicating increased iron levels in these structures. Significant decreases in magnetic susceptibility were found in the substantia nigra and hippocampus. In addition, significant volume loss (atrophy) and an increase effective relaxation were observed in the caudate nucleus and putamen. Susceptibility values in the caudate nucleus and putamen were found to be inversely correlated with structure volumes and directly correlated with the genetic burdens, represented by cytosine-adenine-guanine repeat age-product-scaled scores. CONCLUSIONS The significant magnetic susceptibility differences between subjects with premanifest Huntington disease and controls and their correlation with genetic burden scores indicate the potential use of magnetic susceptibility as a biomarker of disease progression in premanifest Huntington disease.
Collapse
Affiliation(s)
- J M G van Bergen
- From the Departments of Radiology and Radiological Sciences (J.M.G.v.B., J.H., I.A.L.L., C.K.J., P.C.M.v.Z., X.L.) F.M. Kirby Research Center for Functional Brain Imaging (J.M.G.v.B., J.H., I.A.L.L., C.K.J., P.C.M.v.Z., X.L.), Kennedy Krieger Institute, Baltimore, Maryland
| | - J Hua
- From the Departments of Radiology and Radiological Sciences (J.M.G.v.B., J.H., I.A.L.L., C.K.J., P.C.M.v.Z., X.L.) F.M. Kirby Research Center for Functional Brain Imaging (J.M.G.v.B., J.H., I.A.L.L., C.K.J., P.C.M.v.Z., X.L.), Kennedy Krieger Institute, Baltimore, Maryland
| | - P G Unschuld
- Psychiatry and Behavioral Sciences (P.G.U., R.L.M., C.A.R.) Division of Psychiatry Research and Psychogeriatric Medicine (P.G.U.), University of Zurich, Zurich, Switzerland
| | - I A L Lim
- From the Departments of Radiology and Radiological Sciences (J.M.G.v.B., J.H., I.A.L.L., C.K.J., P.C.M.v.Z., X.L.) F.M. Kirby Research Center for Functional Brain Imaging (J.M.G.v.B., J.H., I.A.L.L., C.K.J., P.C.M.v.Z., X.L.), Kennedy Krieger Institute, Baltimore, Maryland
| | - C K Jones
- From the Departments of Radiology and Radiological Sciences (J.M.G.v.B., J.H., I.A.L.L., C.K.J., P.C.M.v.Z., X.L.) F.M. Kirby Research Center for Functional Brain Imaging (J.M.G.v.B., J.H., I.A.L.L., C.K.J., P.C.M.v.Z., X.L.), Kennedy Krieger Institute, Baltimore, Maryland
| | - R L Margolis
- Psychiatry and Behavioral Sciences (P.G.U., R.L.M., C.A.R.) Neurology (R.L.M., C.A.R.), Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - C A Ross
- Psychiatry and Behavioral Sciences (P.G.U., R.L.M., C.A.R.) Neurology (R.L.M., C.A.R.), Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - P C M van Zijl
- From the Departments of Radiology and Radiological Sciences (J.M.G.v.B., J.H., I.A.L.L., C.K.J., P.C.M.v.Z., X.L.) F.M. Kirby Research Center for Functional Brain Imaging (J.M.G.v.B., J.H., I.A.L.L., C.K.J., P.C.M.v.Z., X.L.), Kennedy Krieger Institute, Baltimore, Maryland
| | - X Li
- From the Departments of Radiology and Radiological Sciences (J.M.G.v.B., J.H., I.A.L.L., C.K.J., P.C.M.v.Z., X.L.) F.M. Kirby Research Center for Functional Brain Imaging (J.M.G.v.B., J.H., I.A.L.L., C.K.J., P.C.M.v.Z., X.L.), Kennedy Krieger Institute, Baltimore, Maryland
| |
Collapse
|
11
|
Yoshimoto T, Goto T, Isogai R, Nakamura Y, Takagi H, Ross CA, Inoue M. Magnetophotonic crystal with cerium substituted yttrium iron garnet and enhanced Faraday rotation angle. Opt Express 2016; 24:8746-8753. [PMID: 27137308 DOI: 10.1364/oe.24.008746] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Magnetophotonic crystals (MPCs) comprising cerium-substituted yttrium iron garnet (CeYIG) sandwiched by two Bragg mirrors were fabricated by vacuum annealing. CeYIG was deposited on Bragg mirrors at room temperature and annealed in 5 Pa of residual air. No ceria or other non-garnet phases were detected. Cerium 3 + ions substituted on the yttrium sites and no cerium 4 + ions were found. The Faraday rotation angle of the MPC was -2.92° at a wavelength of λ = 1570 nm was 30 times larger than that of the CeYIG film. These results showed good agreement with calculated values derived using a matrix approach.
Collapse
|
12
|
Florez JM, Negrete OA, Vargas P, Ross CA. Geometrically frustrated Fe2P-like systems: beyond the Fe-trimer approximation. J Phys Condens Matter 2015; 27:286004. [PMID: 26125529 DOI: 10.1088/0953-8984/27/28/286004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Fe(2)P-like structures can be strongly frustrated magnets due to their Kagome/triangular intercalated-layer structure. A complete magnetic solution of the complex spin architecture, and hence the full potential of the magnetic phenomena in Fe(2)P-like material prototypes, is yet to be found. A previous magnetic model for a representative FeCrAs-like system used a mean-field effective-spin to describe the 3g-Wyckoff located Fe-triangles. Such an approach demonstrated the outstanding magnetocaloric properties of the material but left the question of whether the intra-trimer interaction could lead to new physical phenomena and therefore more potentially useful properties. In this work Monte Carlo simulations are employed in order to understand both the influence of the additional degrees of freedom introduced by the Fe-trimers and the changes caused by all the possible exchange couplings between them. Complex scenarios arise, in which FM coupling in the trimers gives rise to both in-plane and out-of-plane inter-layer AFM states; whereas AFM exchange in the trimers gives rise to three distinct states, i.e. AFM-canted layers, a non-collinear superposition of ferromagnetic Kagome/triangular orderings, and tilted inter-planar AFM order. These last three configurations generate a double bifurcated magnetic phase diagram while the first one mimics the behavior seen in a model that treats the trimer as an effective-spin under an applied magnetic field.
Collapse
Affiliation(s)
- J M Florez
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. Departamento de Física, Universidad Técnica Federico Santa María, PO Box 110-V, Valparaíso, Chile
| | | | | | | |
Collapse
|
13
|
Hannon AF, Bai W, Alexander-Katz A, Ross CA. Simulation methods for solvent vapor annealing of block copolymer thin films. Soft Matter 2015; 11:3794-3805. [PMID: 25850069 DOI: 10.1039/c5sm00324e] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Recent progress in modelling the solvent vapor annealing of thin film block copolymers is examined in the context of a self-consistent field theory framework. Key control variables in determining the final microdomain morphologies include swelling ratio or swollen film solvent volume fraction, swollen film thickness, substrate and vapor atmosphere surface energies, effective volume fraction, and effective Flory-Huggins interaction parameter. The regime of solvent vapor annealing studied is where the block copolymer has a high enough Flory-Huggins parameter that ordered structures form during swelling and are then trapped in the system through quenching. Both implicit and explicit consideration of the solvent vapor is considered to distinguish the cases in which solvent vapor leads to a non-bulk morphology. Block-selective solvents are considered based on the experimental systems of polystyrene-b-polydimethylsiloxane annealed with toluene and heptane. The results of these simulations are compared with these experiments.
Collapse
Affiliation(s)
- A F Hannon
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA.
| | | | | | | |
Collapse
|
14
|
Onbaşlı MC, Goto T, Tang A, Pan A, Battal E, Okyay AK, Dionne GF, Ross CA. Oxygen partial pressure dependence of magnetic, optical and magneto-optical properties of epitaxial cobalt-substituted SrTiO₃ films. Opt Express 2015; 23:13399-13409. [PMID: 26074589 DOI: 10.1364/oe.23.013399] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Cobalt-substituted SrTiO3 films (SrTi0.70Co0.30O(3-δ)) were grown on SrTiO3 substrates using pulsed laser deposition under oxygen pressures ranging from 1 μTorr to 20 mTorr. The effect of oxygen pressure on structural, magnetic, optical, and magneto-optical properties of the films was investigated. The film grown at 3 μTorr has the highest Faraday rotation (FR) and magnetic saturation moment (M(s)). Increasing oxygen pressure during growth reduced M(s), FR and optical absorption in the near-infrared. This trend is attributed to decreasing Co2+ ion concentration and oxygen vacancy concentration with higher oxygen partial pressure during growth.
Collapse
|
15
|
Sun XY, Veis M, Kousal J, Jesenska E, Zhang C, Aimon NM, Goto T, Onbasli MC, Kim DH, Choi HK, Ross CA. SrGa(0.7)Co(0.3)O(3-δ) perovskite-cobalt oxide-metal nanocomposite films: magnetic and optical properties. Nanotechnology 2015; 26:115701. [PMID: 25706414 DOI: 10.1088/0957-4484/26/11/115701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Two-phase nanocomposite films consisting of metallic Co nanoparticles below 50 nm diameter in a perovskite matrix were grown by pulsed laser deposition onto (LaAlO3)0.3(Sr2AlTaO6)0.7 (LSAT) and silicon substrates from a target of SrGa0.73Co0.27O3. The particles made up about 6% by volume of the film and were present within the film and at the substrate interface. The saturation magnetization of the film was up to 85 emu cm(-3) at 80 nm thickness and the Faraday rotation (FR) tracked the out-of-plane hysteresis loop, reaching 3000 deg cm(-1) at 10 kOe for 1550 nm wavelength. The magneto-optical figure of merit defined as FR divided by optical absorption was 0.04-0.06 deg dB(-1) due to the high optical absorption of the Co particles.
Collapse
Affiliation(s)
- Xue Yin Sun
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, People's Republic of China
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Aimon NM, Kim DH, Sun X, Ross CA. Multiferroic behavior of templated BiFeO3-CoFe2O4 self-assembled nanocomposites. ACS Appl Mater Interfaces 2015; 7:2263-2268. [PMID: 25559139 DOI: 10.1021/am506089c] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Self-assembled BiFeO3-CoFe2O4 nanocomposites were templated into ordered structures in which the ferrimagnetic CoFe2O4 pillars form square arrays of periods 60-100 nm in a ferroelectric BiFeO3 matrix. The ferroelectricity, magnetism, conductivity, and magnetoelectric coupling of the ordered nanocomposites were characterized by scanning probe microscopy. The insulating BiFeO3 matrix exhibited ferroelectric domains, whereas the resistive CoFe2O4 pillars exhibited single-domain magnetic contrast with high anisotropy due to the magnetoelasticity of the spinel phase. Magnetoelectric coupling was observed in which an applied voltage led to reversal of the magnetic pillars.
Collapse
Affiliation(s)
- Nicolas M Aimon
- Department of Materials Science and Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States
| | | | | | | |
Collapse
|
17
|
Onbasli MC, Goto T, Sun X, Huynh N, Ross CA. Integration of bulk-quality thin film magneto-optical cerium-doped yttrium iron garnet on silicon nitride photonic substrates. Opt Express 2014; 22:25183-25192. [PMID: 25401550 DOI: 10.1364/oe.22.025183] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Cerium substituted yttrium iron garnet (Ce:YIG) films were grown on yttrium iron garnet (YIG) seed layers on silicon nitride films using pulsed laser deposition. Optimal process conditions for forming garnet films on silicon nitride are presented. Bulk or near-bulk magnetic and magneto-optical properties were observed for 160 nm thick Ce:YIG films grown at 640 °C on rapid thermal annealed 40 nm thick YIG grown at 640 °C and 2 Hz pulse rate. The effect of growth temperature and deposition rate on structural, magnetic and magneto-optical properties has been investigated.
Collapse
|
18
|
Goto T, Onbasli MC, Kim DH, Singh V, Inoue M, Kimerling LC, Ross CA. A nonreciprocal racetrack resonator based on vacuum-annealed magnetooptical cerium-substituted yttrium iron garnet. Opt Express 2014; 22:19047-19054. [PMID: 25320991 DOI: 10.1364/oe.22.019047] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Vacuum annealed polycrystalline cerium substituted yttrium iron garnet (CeYIG) films deposited by radio frequency magnetron sputtering on non-garnet substrates were used in nonreciprocal racetrack resonators. CeYIG annealed at 800°C for 30 min provided a large Faraday rotation angle, close to the single crystal value. Crystallinity, magnetic properties, refractive indices and absorption coefficients were measured. The resonant transmission peak of the racetrack resonator covered with CeYIG was non-reciprocally shifted by applying an in-plane magnetic field.
Collapse
|
19
|
Meads C, Nyssen OP, Wong G, Steed L, Bourke L, Ross CA, Hayman S, Field V, Lord J, Greenhalgh T, Taylor SJC. Protocol for an HTA report: Does therapeutic writing help people with long-term conditions? Systematic review, realist synthesis and economic modelling. BMJ Open 2014; 4:e004377. [PMID: 24549165 PMCID: PMC3932001 DOI: 10.1136/bmjopen-2013-004377] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
INTRODUCTION Long-term medical conditions (LTCs) cause reduced health-related quality of life and considerable health service expenditure. Writing therapy has potential to improve physical and mental health in people with LTCs, but its effectiveness is not established. This project aims to establish the clinical and cost-effectiveness of therapeutic writing in LTCs by systematic review and economic evaluation, and to evaluate context and mechanisms by which it might work, through realist synthesis. METHODS Included are any comparative study of therapeutic writing compared with no writing, waiting list, attention control or placebo writing in patients with any diagnosed LTCs that report at least one of the following: relevant clinical outcomes; quality of life; health service use; psychological, behavioural or social functioning; adherence or adverse events. Searches will be conducted in the main medical databases including MEDLINE, EMBASE, PsycINFO, The Cochrane Library and Science Citation Index. For the realist review, further purposive and iterative searches through snowballing techniques will be undertaken. Inclusions, data extraction and quality assessment will be in duplicate with disagreements resolved through discussion. Quality assessment will include using Grading of Recommendations Assessment, Development and Evaluation (GRADE) criteria. Data synthesis will be narrative and tabular with meta-analysis where appropriate. De novo economic modelling will be attempted in one clinical area if sufficient evidence is available and performed according to the National Institute for Health and Care Excellence (NICE) reference case.
Collapse
Affiliation(s)
- C Meads
- Health Economics Research Group, Brunel University, Middlesex, UK
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Abstract
A two-stage annealing process for block copolymer films was introduced consisting of a solvent vapor exposure followed by a thermal cycle. By heating the film but not the chamber, changes in the ambient vapor pressure of the solvent were avoided. Films of block copolymers and homopolymers showed transient nonmonotonic swelling behavior immediately after solvent exposure that was dependent on how the thin film was cast before the anneal. Thermal cycling of the solvent-swelled block copolymer films during the solvent vapor anneal (SVA) caused the films to deswell in 1-10 s and produced well-ordered microdomains in templated 45.5 and 51.5 kg/mol polystyrene-block-polydimethylsiloxane films annealed in toluene and n-heptane vapors for total process times of 30 s to 5 min.
Collapse
Affiliation(s)
- Kevin W Gotrik
- Department of Materials Science and Engineering, Massachusetts Institute of Technology , 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
| | | |
Collapse
|
21
|
Unschuld PG, Buchholz AS, Varvaris M, van Zijl PCM, Ross CA, Pekar JJ, Hock C, Sweeney JA, Tamminga CA, Keshavan MS, Pearlson GD, Thaker GK, Schretlen DJ. Prefrontal brain network connectivity indicates degree of both schizophrenia risk and cognitive dysfunction. Pharmacopsychiatry 2013. [DOI: 10.1055/s-0033-1353346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
22
|
Florez JM, Vargas P, Garcia C, Ross CA. Magnetic entropy change plateau in a geometrically frustrated layered system: FeCrAs-like iron-pnictide structure as a magnetocaloric prototype. J Phys Condens Matter 2013; 25:226004. [PMID: 23673475 DOI: 10.1088/0953-8984/25/22/226004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Monte Carlo modeling suggests that the magnetothermal features of the Fe2P-structured FeCrAs-like compound offer a promising route for the design of magnetocaloric materials. The prototype structure is modeled as antiferromagnetically coupled layered Heisenberg systems mimicking the distorted Kagome/triangular stacked architecture of FeCrAs iron-pnictide. The magnetic entropy change ΔSm(T) presents a plateau-like behavior which can be tailored by tuning either the JCr-Fe/JCr-Cr exchange energy ratio or the magnetic field. The plateau is defined by cooperative spin ordering within a ferrimagnetic region which exists between two critical temperatures separating at the lower bound (Tac) a canted antiferromagnetic phase and at the upper bound (Tdc) the thermally disordered phase. The refrigerant capacity and adiabatic change of temperature are A(H)(Tdc - Tac) and A(H)Tp/Cm respectively, with Tac < Tp < Tdc, A(H) an increasing positive function of the field defining the height of the plateau and Cm the magnetic specific heat, whose critical behavior is related to the T(a,d)(c) values.
Collapse
Affiliation(s)
- J M Florez
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | | | | | | |
Collapse
|
23
|
Park WI, You BK, Mun BH, Seo HK, Lee JY, Hosaka S, Yin Y, Ross CA, Lee KJ, Jung YS. Self-assembled incorporation of modulated block copolymer nanostructures in phase-change memory for switching power reduction. ACS Nano 2013; 7:2651-2658. [PMID: 23451771 DOI: 10.1021/nn4000176] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Phase change memory (PCM), which exploits the phase change behavior of chalcogenide materials, affords tremendous advantages over conventional solid-state memory due to its nonvolatility, high speed, and scalability. However, high power consumption of PCM poses a critical challenge and has been the most significant obstacle to its widespread commercialization. Here, we present a novel approach based on the self-assembly of a block copolymer (BCP) to form a thin nanostructured SiOx layer that locally blocks the contact between a heater electrode and a phase change material. The writing current is decreased 5-fold (corresponding to a power reduction by 1/20) as the occupying area fraction of SiOx nanostructures is increased from a fill factor of 9.1% to 63.6%. Simulation results theoretically explain the current reduction mechanism by localized switching of BCP-blocked phase change materials.
Collapse
Affiliation(s)
- Woon Ik Park
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea
| | | | | | | | | | | | | | | | | | | |
Collapse
|
24
|
Kim DH, Aimon NM, Bi L, Florez JM, Dionne GF, Ross CA. Magnetostriction in epitaxial SrTi(1-x)Fe(x)O(3-δ) perovskite films with x = 0.13 and 0.35. J Phys Condens Matter 2013; 25:026002. [PMID: 23178936 DOI: 10.1088/0953-8984/25/2/026002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The crystal structure, magnetic anisotropy and magnetoelasticity of epitaxial SrTi(0.87)Fe(0.13)O(3-δ) (STF13) and SrTi(0.65)Fe(0.35)O(3-δ) (STF35) films grown on (001), (011), and (111) oriented SrTiO(3) substrates were investigated. The films grew with compressive in-plane strain and underwent tetragonal, monoclinic, and rhombohedral distortions on the (001), (011), and (111) substrates, respectively. All samples showed room temperature magnetic hysteresis loops with strong out-of-plane anisotropy. The resulting magnetoelastic anisotropy was an order of magnitude greater than the magnetocrystalline and shape anisotropies. Magnetoelastic coefficients of B(1) =- 6.7 × 10(6) and B(2) =- 28 to -26 × 10(6) erg cm(-3) for STF13 and B(1) =- 2.0 × 10(6) and B(2) =- 5.4 to -3.9 × 10(6) erg cm(-3) for STF35 were determined from the magnetic anisotropy and lattice strain, corresponding to magnetostriction constants of λ(100) = 2.09 × 10(-6) and λ(111) = 7.68 × 10(-6) for STF13, and λ(100) = 0.62 × 10(-6) and λ(111) = 1.07 × 10(-6) for STF35.
Collapse
Affiliation(s)
- Dong Hun Kim
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, USA
| | | | | | | | | | | |
Collapse
|
25
|
Goto T, Onbaşlı MC, Ross CA. Magneto-optical properties of cerium substituted yttrium iron garnet films with reduced thermal budget for monolithic photonic integrated circuits. Opt Express 2012; 20:28507-28517. [PMID: 23263087 DOI: 10.1364/oe.20.028507] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Thin films of polycrystalline cerium substituted yttrium iron garnet (CeYIG) were grown on an yttrium iron garnet (YIG) seed layer on Si and Si-on-insulator substrates by pulsed laser deposition, and their optical and magneto-optical properties in the near-IR region were measured. A YIG seed layer of ~30 nm thick processed by rapid thermal anneal at 800°C provided a virtual substrate to promote crystallization of the CeYIG. The effect of the thermal budget of the YIG/CeYIG growth process on the film structure, magnetic and magnetooptical properties was determined.
Collapse
Affiliation(s)
- Taichi Goto
- Department of Materials and Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA.
| | | | | |
Collapse
|
26
|
Mattis VB, Svendsen SP, Ebert A, Svendsen CN, King AR, Casale M, Winokur ST, Batugedara G, Vawter M, Donovan PJ, Lock LF, Thompson LM, Zhu Y, Fossale E, Atwal RS, Gillis T, Mysore J, Li JH, Seong IS, Shen Y, Chen X, Wheeler VC, MacDonald ME, Gusella JF, Akimov S, Arbez N, Juopperi T, Ratovitski T, Chiang JH, Kim WR, Chighladze E, Watkin E, Zhong C, Makri G, Cole RN, Margolis RL, Song H, Ming G, Ross CA, Kaye JA, Daub A, Sharma P, Mason AR, Finkbeiner S, Yu J, Thomson JA, Rushton D, Brazier SP, Battersby AA, Redfern A, Tseng HE, Harrison AW, Kemp PJ, Allen ND, Onorati M, Castiglioni V, Cattaneo E, Arjomand J. A11 Induced pluripotent stem cells for basic and translational research on HD. J Neurol Neurosurg Psychiatry 2012. [DOI: 10.1136/jnnp-2012-303524.11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
27
|
Lee JM, Ramos EM, Lee JH, Gillis T, Mysore JS, Hayden MR, Warby SC, Morrison P, Nance M, Ross CA, Margolis RL, Squitieri F, Orobello S, Di Donato S, Gomez-Tortosa E, Ayuso C, Suchowersky O, Trent RJA, McCusker E, Novelletto A, Frontali M, Jones R, Ashizawa T, Frank S, Saint-Hilaire MH, Hersch SM, Rosas HD, Lucente D, Harrison MB, Zanko A, Abramson RK, Marder K, Sequeiros J, Paulsen JS, Landwehrmeyer GB, Myers RH, MacDonald ME, Gusella JF. CAG repeat expansion in Huntington disease determines age at onset in a fully dominant fashion. Neurology 2012; 78:690-5. [PMID: 22323755 DOI: 10.1212/wnl.0b013e318249f683] [Citation(s) in RCA: 220] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE Age at onset of diagnostic motor manifestations in Huntington disease (HD) is strongly correlated with an expanded CAG trinucleotide repeat. The length of the normal CAG repeat allele has been reported also to influence age at onset, in interaction with the expanded allele. Due to profound implications for disease mechanism and modification, we tested whether the normal allele, interaction between the expanded and normal alleles, or presence of a second expanded allele affects age at onset of HD motor signs. METHODS We modeled natural log-transformed age at onset as a function of CAG repeat lengths of expanded and normal alleles and their interaction by linear regression. RESULTS An apparently significant effect of interaction on age at motor onset among 4,068 subjects was dependent on a single outlier data point. A rigorous statistical analysis with a well-behaved dataset that conformed to the fundamental assumptions of linear regression (e.g., constant variance and normally distributed error) revealed significance only for the expanded CAG repeat, with no effect of the normal CAG repeat. Ten subjects with 2 expanded alleles showed an age at motor onset consistent with the length of the larger expanded allele. CONCLUSIONS Normal allele CAG length, interaction between expanded and normal alleles, and presence of a second expanded allele do not influence age at onset of motor manifestations, indicating that the rate of HD pathogenesis leading to motor diagnosis is determined by a completely dominant action of the longest expanded allele and as yet unidentified genetic or environmental factors.
Collapse
Affiliation(s)
- J-M Lee
- Center for Human Genetic Research, Massachusetts General Hospital, Boston, MA, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
28
|
Abstract
OBJECTIVE Catatonia is considered a unique syndrome of motor signs, at times life-threatening when aggravated by autonomic dysfunction and fever, but eminently treatable with specific medical treatments, if recognized early. Catatonia commonly occurs in children and adolescents with a wide range of associated disorders. The role of deprivation, abuse, or trauma in the development of pediatric catatonia is examined. METHOD Reports considering deprivation, abuse, or trauma as precipitants of catatonia in pediatric cases are culled from the classic writings on catatonia and from a selective review of modern contributions. RESULTS Kahlbaum gave trauma a central role in catatonia in many young adult cases. Kanner described children with psychogenic catalepsy. Anaclitic depression, a condition found by Spitz in deprived institutionalized children, strongly resembles stuporous catatonia. Leonhard considered lack of communication with the mother or substitute mother as an important risk factor for childhood catatonia. Children including those with autism who experience emotional and physical trauma sometimes develop catatonia. The clinical descriptions of children with classic catatonic syndromes and those of contemporary refugee children with a syndrome labeled Pervasive Refusal Syndrome are similar. CONCLUSION The literature supports the view that deprivation, abuse, and trauma can precipitate catatonia in children and adolescents.
Collapse
Affiliation(s)
- D M Dhossche
- Department of Psychiatry, University of Mississippi Medical Center, Jackson, 39216, USA.
| | | | | |
Collapse
|
29
|
Li X, Tamashiro KLK, Liu Z, Bello NT, Wang X, Aja S, Bi S, Ladenheim EE, Ross CA, Moran TH, Smith WW. A novel obesity model: synphilin-1-induced hyperphagia and obesity in mice. Int J Obes (Lond) 2011; 36:1215-21. [PMID: 22158267 PMCID: PMC3439552 DOI: 10.1038/ijo.2011.235] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Aims The pathogenesis of obesity remains incompletely understood and the exploration of the role of novel proteins in obesity may provide important insights into its causes and treatments. Here we report a previously unidentified role for synphilin-1 in the controls of food intake and body weight. Synphilin-1, a cytoplasmic protein, was initially identified as an interaction partner of alpha-synuclein, and has implications in Parkinson's disease pathogenesis related to protein aggregation. Subjects and methods To study the in vivo role of synphilin-1, we characterized a human synphilin-1 transgenic mouse (SP1) by assessing synphilin-1 expression, plasma parameters, food intake and spontaneous activity to determine the major behavioral changes and their consequences in the development of the obesity phenotype. Results Expression of human synphilin-1 in brain neurons in SP1 mice resulted in increased food intake, body weight and body fat. SP1 mice also displayed hyperinsulinemia, hyperleptinemia and impaired glucose tolerance. Pair-feeding SP1 mice to amounts consumed by non-transgenic mice prevented the increased body weight, adiposity, hyperinsulinemia and hyperleptinemia demonstrating that these were all the consequences of increased food intake. Transgenic expression of synphilin-1 was enriched in hypothalamic nuclei involved in feeding control, and fasting induced elevated endogenous synphilin-1 levels at these sites, suggesting that synphilin-1 is an important player in the hypothalamic energy balance regulatory system. Conclusion These studies identify a novel function of synphilin-1 in controlling food intake and body weight, and may provide a unique obesity model for future studies of obesity pathogenesis and therapeutics.
Collapse
Affiliation(s)
- X Li
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD 21201, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Jeong JW, Park WI, Kim MJ, Ross CA, Jung YS. Highly tunable self-assembled nanostructures from a poly(2-vinylpyridine-b-dimethylsiloxane) block copolymer. Nano Lett 2011; 11:4095-101. [PMID: 21950245 DOI: 10.1021/nl2016224] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
An extraordinarily large degree of tunability in geometry and dimension is demonstrated in films of a self-assembled block copolymer. A poly(2-vinylpyridine-b-dimethylsiloxane) block copolymer with highly incompatible blocks was spun-cast on patterned substrates and treated with various solvent vapors. The degree of selective swelling in the poly(2-vinylpyridine) matrix block could be controlled over an extensive range, leading to the formation of various microdomain morphologies such as spheres, cylinders, hexagonally perforated lamellae, and lamellae from the same block copolymer. The systematic control of swelling ratio and the choice of solvent vapors offer the unusual ability to control the width of very well-ordered linear features within a range between 6 and 31 nm. This methodology is particularly useful for nanolithography based on directed self-assembly in that a single block copolymer film can form microdomains with a broad range of geometries and sizes without the need to change molecular weight or volume fraction.
Collapse
Affiliation(s)
- Jae Won Jeong
- Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology , 291 Daehak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea
| | | | | | | | | |
Collapse
|
31
|
Sanz R, Navas D, Vazquez M, Hernández-Vélez M, Ross CA. Preparation and magnetic properties of cylindrical NiFe films and antidot arrays. J Nanosci Nanotechnol 2010; 10:6775-6778. [PMID: 21137795 DOI: 10.1166/jnn.2010.2525] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Continuous NiFe (Permalloy) cylindrical films and arrays of cylindrical NiFe antidots 7 nm thick have been prepared by sputtering onto cylindrical aluminum wires and onto wires anodized to form a porous anodic alumina layer. The antidots are arranged in a close-packed pattern determined by the hexagonal pore arrangement in the porous alumina, with period 103 nm and diameter 42 nm. Hysteresis loops were measured at different angles with respect to the cylinder axis and indicate an easy plane normal to the radius of the wire. The antidots enhance the coercivity compared to the continuous cylindrical film.
Collapse
Affiliation(s)
- R Sanz
- Instituto de Ciencia de Materiales de Madrid, CSIC. 28049 Madrid, Spain
| | | | | | | | | |
Collapse
|
32
|
Jung YS, Lee JH, Lee JY, Ross CA. Fabrication of diverse metallic nanowire arrays based on block copolymer self-assembly. Nano Lett 2010; 10:3722-3726. [PMID: 20698484 DOI: 10.1021/nl1023518] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Metallic nanowires are useful for fabricating highly integrated nanoscale electrical, magnetic, and photonic devices. However, conventional methods based on bottom-up growth techniques are subject to concerns such as broad distributions in their dimension as well and difficulties in precise placement of the nanowires. These issues can be solved by the guided self-assembly of block copolymer thin films that can produce periodic arrays of monodisperse nanoscale features with excellent positional accuracy. Here, we report transfer of high-quality linear block copolymer patterns into various metals, Ti, W, Pt, Co, Ni, Ta, Au, and Al, to fabricate highly ordered nanowire arrays with widths down to 9 nm. This novel patterning process does not require specific film deposition techniques or etch-chemistries. We also describe their structural, magnetic, and electrical properties.
Collapse
Affiliation(s)
- Yeon Sik Jung
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
| | | | | | | |
Collapse
|
33
|
Yang JKW, Jung YS, Chang JB, Mickiewicz RA, Alexander-Katz A, Ross CA, Berggren KK. Complex self-assembled patterns using sparse commensurate templates with locally varying motifs. Nat Nanotechnol 2010; 5:256-60. [PMID: 20228786 DOI: 10.1038/nnano.2010.30] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2009] [Accepted: 02/01/2010] [Indexed: 05/20/2023]
Abstract
Templated self-assembly of block copolymer thin films can generate periodic arrays of microdomains within a sparse template, or complex patterns using 1:1 templates. However, arbitrary pattern generation directed by sparse templates remains elusive. Here, we show that an array of carefully spaced and shaped posts, prepared by electron-beam patterning of an inorganic resist, can be used to template complex patterns in a cylindrical-morphology block copolymer. We use two distinct methods: making the post spacing commensurate with the equilibrium periodicity of the polymer, which controls the orientation of the linear features, and making local changes to the shape or distribution of the posts, which direct the formation of bends, junctions and other aperiodic features in specific locations. The first of these methods permits linear patterns to be directed by a sparse template that occupies only a few percent of the area of the final self-assembled pattern, while the second method can be used to selectively and locally template complex linear patterns.
Collapse
Affiliation(s)
- Joel K W Yang
- Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
| | | | | | | | | | | | | |
Collapse
|
34
|
Abstract
The templated self-assembly of block copolymer (BCP) thin films can generate regular arrays of 10-50 nm scale features with good positional and orientational accuracy, but the ordering, registration and pattern transfer of sub-10-nm feature sizes is not well established. Here, we report solvent-annealing and templating methods that enable the formation of highly ordered grating patterns with a line width of 8 nm and period 17 nm from a self-assembled poly(styrene-b-dimethylsiloxane) (PS-PDMS) diblock copolymer. The BCP patterns can be registered hierarchically on a larger-period BCP pattern, which can potentially diversify the available pattern geometries and enables precise pattern registration at small feature sizes. Sub-10-nm-wide tungsten nanowires with excellent order and uniformity were fabricated from the self-assembled patterns using a reactive ion etching process.
Collapse
Affiliation(s)
- Yeon Sik Jung
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
| | | | | | | | | |
Collapse
|
35
|
Li X, Liu Z, Tamashiro K, Shi B, Rudnicki DD, Ross CA, Moran TH, Smith WW. Synphilin-1 exhibits trophic and protective effects against Rotenone toxicity. Neuroscience 2010; 165:455-62. [PMID: 19857556 DOI: 10.1016/j.neuroscience.2009.10.042] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2009] [Accepted: 10/19/2009] [Indexed: 12/21/2022]
Abstract
Synphilin-1 is a cytoplasmic protein with unclear function. Synphilin-1 has been identified as an interaction partner of alpha-synuclein. The interaction between synphilin-1 and alpha-synuclein has implications in Parkinson's disease. In this study, we stably overexpressed human synphilin-1 in mouse N1E-115 neuroblastoma cells. We found that overexpression of synphilin-1 shortened cell growth doubling time and increased neurite outgrowth. Knockdown of endogenous synphilin-1 caused neuronal toxicity and shortened neurite outgrowth. We further found that synphilin-1 increased activation of the extracellular signal-regulated kinases (ERK1/2) and mediated neurite outgrowth. Rotenone, mitochondrial complex I inhibitor, has been shown previously to induce dopaminergic neurodegeneration and Parkinsonism in rats and Drosophila. We found that Rotenone induced apoptotic cell death in N1E-115 cells via caspase-3 activation and poly (ADP-ribose) polymerase (PARP) cleavage. Overexpression of synphilin-1 significantly reduced Rotenone-induced cell death, caspase-3 activation and PARP cleavage. The results indicate that synphilin-1 displays trophic and protective effects in vitro, suggesting that synphilin-1 may play a protective role in Parkinson's disease (PD) pathogenesis and may lead to a potential therapeutic target for PD intervention.
Collapse
Affiliation(s)
- X Li
- Xi'an Jiaotong University School of Medicine, Xi'an, Shaanxi, PR China
| | | | | | | | | | | | | | | |
Collapse
|
36
|
Ross CA, Goldner EM. Stigma, negative attitudes and discrimination towards mental illness within the nursing profession: a review of the literature. J Psychiatr Ment Health Nurs 2009; 16:558-67. [PMID: 19594679 DOI: 10.1111/j.1365-2850.2009.01399.x] [Citation(s) in RCA: 219] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The aim of this paper was to review the existing literature pertaining to stigma, negative attitudes and discrimination towards mental illness, specifically as viewed through the lens of the nursing profession. The results of the literature review were synthesized and analysed, and the major themes drawn from this were found to correspond with Schulze's model identifying three positions that healthcare workers may assume in relation to stigma of mental illness: 'stigmatizers', 'stigmatized' and 'de-stigmatizers'. In this paper, the nursing profession is examined from the perspectives of the first two major themes: the 'stigmatizers' and 'stigmatized'. Their primary sub-themes are identified and discussed: (1) Nurses as 'the stigmatizers': (a) nurses' attitudes in general medical settings towards patients with psychiatric illness and (b) psychiatric nurses; (2) Nurses as 'the stigmatized': (a) nurses who have mental illness and (b) stigma within the profession against psychiatric nurses and/or psychiatry in general. The secondary and tertiary sub-themes are also identified and reviewed.
Collapse
Affiliation(s)
- C A Ross
- BSN Program, Faculty of Health Sciences, Douglas College, Coquitlam, BC, Canada.
| | | |
Collapse
|
37
|
Reading S, McEntee J, Tennis R, Bakker A, Yoritomo N, Pekar J, Mori S, van Zijl P, Margolis RL, Ross CA. Relationship of frontal lobe bold signal and fractional anisotropy in subjects with schizophrenia during a Stroop interference task. Neuroimage 2009. [DOI: 10.1016/s1053-8119(09)71655-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
|
38
|
Nopoulos PC, Johnson HJ, Magnotta VA, Pierson RK, Langbehn DR, Ross CA, Aylward EH, Paulsen JS. Global and Regional Brain Morphology in Subjects with Huntington's Disease Prior to Diagnosis. Neuroimage 2009. [DOI: 10.1016/s1053-8119(09)70715-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
|
39
|
Aylward EH, Nopoulos PC, Pierson RK, Langbehn DR, Ross CA, Paulsen JS. Longitudinal Change in Striatal Volume in Pre-Clinical Huntington's Disease. Neuroimage 2009. [DOI: 10.1016/s1053-8119(09)70738-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
|
40
|
Jung YS, Jung W, Tuller HL, Ross CA. Nanowire conductive polymer gas sensor patterned using self-assembled block copolymer lithography. Nano Lett 2008; 8:3776-3780. [PMID: 18954147 DOI: 10.1021/nl802099k] [Citation(s) in RCA: 123] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Nanostructured conjugated organic thin films are essential building blocks for highly integrated organic devices. We demonstrate the large-area fabrication of an array of well-ordered 15 nm wide conducting polymer nanowires by using an etch mask consisting of self-assembled patterns of cylinder-forming poly(styrene-b-dimethylsiloxane) diblock copolymer confined in topographic templates. The poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) nanowires operated as an ethanol vapor sensor, suggesting that the electronic properties of the organic film were preserved during the patterning processes. The higher sensitivity to ethanol vapor, compared to an unpatterned film with the same thickness, was attributed to the enhanced surface-to-volume ratio of the nanowire array.
Collapse
Affiliation(s)
- Yeon Sik Jung
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | | | | | | |
Collapse
|
41
|
Jung YS, Jung W, Ross CA. Nanofabricated concentric ring structures by templated self-assembly of a diblock copolymer. Nano Lett 2008; 8:2975-2981. [PMID: 18687011 DOI: 10.1021/nl802011w] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The formation of well-controlled circular patterns on the nanoscale is important for the fabrication of a range of devices such as sensors, memories, lasers, transistors, and quantum devices. Concentric, smooth ring patterns with tunable dimensions have been formed from a cylinder-forming poly(styrene- b-dimethylsiloxane) (PS-PDMS) diblock copolymer under confinement in shallow circular trenches. The high etch selectivity between PS and PDMS facilitates pattern transfer, illustrated by the fabrication of arrays of ferromagnetic cobalt rings with a density of 1.1 x 10 (9)/cm (2). The effects of confinement diameter and commensurability on the diameter and period of the concentric rings are analyzed using a free energy model that includes interfacial, strain, and bending energies. This work provides a simple process for the fabrication of nanoscale circular patterns with very narrow line width using a much coarser-scale template, and may facilitate the miniaturization of a variety of microelectronic devices.
Collapse
Affiliation(s)
- Yeon Sik Jung
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | | | | |
Collapse
|
42
|
Paulsen JS, Langbehn DR, Stout JC, Aylward E, Ross CA, Nance M, Guttman M, Johnson S, MacDonald M, Beglinger LJ, Duff K, Kayson E, Biglan K, Shoulson I, Oakes D, Hayden M. Detection of Huntington's disease decades before diagnosis: the Predict-HD study. J Neurol Neurosurg Psychiatry 2008; 79:874-80. [PMID: 18096682 PMCID: PMC2569211 DOI: 10.1136/jnnp.2007.128728] [Citation(s) in RCA: 588] [Impact Index Per Article: 36.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
OBJECTIVE The objective of the Predict-HD study is to use genetic, neurobiological and refined clinical markers to understand the early progression of Huntington's disease (HD), prior to the point of traditional diagnosis, in persons with a known gene mutation. Here we estimate the approximate onset and initial course of various measurable aspects of HD relative to the time of eventual diagnosis. METHODS We studied 438 participants who were positive for the HD gene mutation, but did not yet meet the diagnostic criteria for HD and had no functional decline. Predictability of baseline cognitive, motor, psychiatric and imaging measures was modelled non-linearly using estimated time until diagnosis (based on CAG repeat length and current age) as the predictor. RESULTS Estimated time to diagnosis was related to most clinical and neuroimaging markers. The patterns of association suggested the commencement of detectable changes one to two decades prior to the predicted time of clinical diagnosis. The patterns were highly robust and consistent, despite the varied types of markers and diverse measurement methodologies. CONCLUSIONS These findings from the Predict-HD study suggest the approximate time scale of measurable disease development, and suggest candidate disease markers for use in preventive HD trials.
Collapse
Affiliation(s)
- J S Paulsen
- University of Iowa, Roy J and Lucille A Carver College of Medicine Research, 1-305 Medical Education Building, Iowa City, IA 52242-1000, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
43
|
Pletnikov MV, Ayhan Y, Nikolskaia O, Xu Y, Ovanesov MV, Huang H, Mori S, Moran TH, Ross CA. Inducible expression of mutant human DISC1 in mice is associated with brain and behavioral abnormalities reminiscent of schizophrenia. Mol Psychiatry 2008; 13:173-86, 115. [PMID: 17848917 DOI: 10.1038/sj.mp.4002079] [Citation(s) in RCA: 288] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
A strong candidate gene for schizophrenia and major mental disorders, disrupted-in-schizophrenia 1 (DISC1) was first described in a large Scottish family in which a balanced chromosomal translocation segregates with schizophrenia and other psychiatric illnesses. The translocation mutation may result in loss of DISC1 function via haploinsufficiency or dominant-negative effects of a predicted mutant DISC1 truncated protein product. DISC1 has been implicated in neurodevelopment, including maturation of the cerebral cortex. To evaluate the neuronal and behavioral effects of mutant DISC1, the Tet-off system under the regulation of the CAMKII promoter was used to generate transgenic mice with inducible expression of mutant human DISC1 (hDISC1) limited to forebrain regions, including cerebral cortex, hippocampus and striatum. Expression of mutant hDISC1 was not associated with gross neurodevelopmental abnormalities, but led to a mild enlargement of the lateral ventricles and attenuation of neurite outgrowth in primary cortical neurons. These morphological changes were associated with decreased protein levels of endogenous mouse DISC1, LIS1 and SNAP-25. Compared to their sex-matched littermate controls, mutant hDISC1 transgenic male mice exhibited spontaneous hyperactivity in the open field and alterations in social interaction, and transgenic female mice showed deficient spatial memory. The results show that the neuronal and behavioral effects of mutant hDISC1 are consistent with a dominant-negative mechanism, and are similar to some features of schizophrenia. The present mouse model may facilitate the study of aspects of the pathogenesis of schizophrenia.
Collapse
Affiliation(s)
- M V Pletnikov
- Division of Neurobiology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
44
|
Pletnikov MV, Ayhan Y, Xu Y, Nikolskaia O, Ovanesov M, Huang H, Mori S, Moran TH, Ross CA. Enlargement of the lateral ventricles in mutant DISC1 transgenic mice. Mol Psychiatry 2008; 13:115. [PMID: 18202691 DOI: 10.1038/sj.mp.4002144] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- M V Pletnikov
- Division of Neurobiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
45
|
Ross CA, Becher MW, Colomer V, Engelender S, Wood JD, Sharp AH. Huntington's disease and dentatorubral-pallidoluysian atrophy: proteins, pathogenesis and pathology. Brain Pathol 2008; 7:1003-16. [PMID: 9217980 PMCID: PMC8098431 DOI: 10.1111/j.1750-3639.1997.tb00898.x] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Each of the glutamine repeat neurodegenerative diseases has a particular pattern of pathology largely restricted to the CNS. However, there is considerable overlap among the regions affected, suggesting that the diseases share pathogenic mechanisms, presumably involving the glutamine repeats. We focus on Huntington's disease (HD) and Dentatorubral-pallidoluysian atrophy (DRPLA) as models for this family of diseases, since they have striking similarities and also notable differences in their clinical features and pathology. We review the pattern of pathology in adult and juvenile onset cases. Despite selective pathology, the disease genes and their protein products (huntingtin and atrophin-1) are widely expressed. This presents a central problem for all the glutamine repeat diseases-how do widely expressed gene products give rise to restricted pathology? The pathogenic effects are believed to occur via a "gain of function" mechanism at the protein level. Mechanisms of cell death may include excitotoxicity, metabolic toxicity, apoptosis, and free radical stress. Emerging data indicate that huntingtin and atrophin-1 may have distinct protein interactions. The specific interaction partners may help explain the selective pathology of these diseases.
Collapse
Affiliation(s)
- C A Ross
- Department of Psychiatry, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205-2196, USA
| | | | | | | | | | | |
Collapse
|
46
|
Petrovich GD, Ross CA, Holland PC, Gallagher M. Medial prefrontal cortex is necessary for an appetitive contextual conditioned stimulus to promote eating in sated rats. J Neurosci 2007; 27:6436-41. [PMID: 17567804 PMCID: PMC3219438 DOI: 10.1523/jneurosci.5001-06.2007] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Motivation plays an important role in the control of food intake. A cue that acquires motivational properties through pairings with food consumption when an animal is hungry can override satiety and promote eating in sated rats. This phenomenon of conditioned potentiation of feeding is mediated by connections between the forebrain and the lateral hypothalamic area (LHA). In a recent study using markers for cellular activation, neurons in the ventral medial prefrontal cortex (vmPFC) that project directly to the LHA were strongly engaged after exposure to a conditioned cue that stimulates eating in sated rats. Here, we examined whether those vmPFC neurons are necessary for conditioned potentiation of eating. We trained rats in a paradigm in which the context provided conditioning cues. Rats with bilateral neurotoxic lesions of vmPFC were impaired in context-enhanced food consumption in tests when the rats were sated. At the same time, vmPFC lesions did not produce changes in food consumption in the home cage or changes in body weight during training. Thus, vmPFC neurotoxic lesions produced impairment in food consumption specifically driven by conditioned motivational cues. The current findings suggest a critical role for vmPFC in the brain network that mediates control of conditioned motivation to eat perhaps by a mechanism akin to appetite or craving.
Collapse
Affiliation(s)
- Gorica D Petrovich
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, Maryland 21218, USA.
| | | | | | | |
Collapse
|
47
|
Abstract
Templated self-assembly of a cylinder-forming poly(styrene-b-dimethylsiloxane) (PS-PDMS) diblock copolymer has been investigated for nanolithography applications. The large chi-parameter of the blocks and the use of a PDMS-brush substrate surface treatment are especially advantageous for achieving long-range ordering and minimizing defect densities, and the high Si content in PDMS leaves a robust oxide etch mask after two-step reactive ion etching. By adjusting mesa width and solvent-annealing vapor pressure and time, the cylinders can be intentionally oriented parallel or perpendicular to the trench walls. Pattern transfer into thin silica is also demonstrated. This block copolymer system has excellent characteristics for self-assembled nanolithography applications.
Collapse
Affiliation(s)
- Yeon Sik Jung
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | | |
Collapse
|
48
|
Abstract
The flux-closed or "vortex" state in thin-film magnetic rings has been proposed as a data storage token, but it has proven difficult to control the vortex chirality in a simple manner. Here, a model is described that predicts the vortex chirality of an elliptical magnetic ring as a function of the direction of the applied field and of the exchange bias, based on the change in energy of the system as the domain walls move. Experimental measurements of chirality in Co and Co/IrMn magnetic rings with 3.2 microm major axis are in excellent agreement with the model. The vortex circulation direction can therefore be tailored with an appropriate combination of applied field direction and exchange bias direction with respect to the major axis.
Collapse
Affiliation(s)
- W Jung
- Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | | | | |
Collapse
|
49
|
Petrovich GD, Ross CA, Gallagher M, Holland PC. Learned contextual cue potentiates eating in rats. Physiol Behav 2006; 90:362-7. [PMID: 17078980 PMCID: PMC1892280 DOI: 10.1016/j.physbeh.2006.09.031] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2006] [Revised: 09/08/2006] [Accepted: 09/22/2006] [Indexed: 01/13/2023]
Abstract
Explicit cues associated with food consumption when hunger prevails will enhance eating when they are subsequently presented under conditions of satiety. Here we examined whether contextual conditioned stimuli (CSs) paired with consumption of food pellets while rats were food-deprived would enhance consumption of this food in rats that were not food-deprived. The conditioning context enhanced rats' consumption of the training food, but it did not change their consumption of the familiar, lab chow. These results show that the contextual CSs, like discrete cues, could modulate food consumption in a CS-potentiated eating paradigm. Furthermore, the data suggest that CS-potentiation of eating does not induce a general motivation to eat, akin to hunger, but instead more likely produces a more specific motivational state, akin to craving.
Collapse
Affiliation(s)
- Gorica D Petrovich
- Department of Psychological and Brain Sciences, Johns Hopkins University, 3400 North Charles St., Baltimore, MD 21218, United States.
| | | | | | | |
Collapse
|
50
|
Holmes SE, Wentzell JS, Seixas AI, Callahan C, Silveira I, Ross CA, Margolis RL. A novel trinucleotide repeat expansion at chromosome 3q26.2 identified by a CAG/CTG repeat expansion detection array. Hum Genet 2006; 120:193-200. [PMID: 16783570 DOI: 10.1007/s00439-006-0207-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2006] [Revised: 05/11/2006] [Accepted: 05/12/2006] [Indexed: 11/30/2022]
Abstract
CAG/CTG repeat expansions cause at least 12 different neurological disorders, and additional disorders of this type probably exist. Using the repeat expansion detection (RED) assay, we identified an expanded CAG/CTG repeat in a 50-year-old woman with an autosomal dominant syndrome with prominent progressive sensory neuropathy. The expansion could not be accounted for by any of the CAG/CTG repeats known to undergo expansion. To identify the locus of the expansion, we created a PCR array to assess the repeat length of all repeats of eight or more CAG or CTG triplets in the human genome. The expansion was localized to a repeat contained in an intron of a Genscan-predicted gene, 185 nt downstream of a predicted exon that is conserved through mouse. The closest experimentally verified gene in the region (TNIK, encoding a serine/threonine kinase) occurs approximately 63 Kb downstream from the repeat. The length of the expansion in the proband is 98 triplets. This repeat is not expanded in the proband's cousin (the only other affected family member for whom DNA is currently available) and no expansions were detected in a set of 230 patients with movement disorders of unknown cause. An expanded allele containing 58 triplets was detected in a single control individual, and no other expansions were detected in a set of 255 controls. The normal repeat length ranges from 5 to 30 triplets, with 8 triplets the most common allele. Our results suggest that this new repeat expansion is probably not the direct cause of the phenotype in the proband. Whether the repeat contributes to the patient's phenotype, or is associated with another phenotype, remains to be determined.
Collapse
Affiliation(s)
- S E Holmes
- Laboratory of Genetic Neurobiology, Division of Neurobiology, Department of Psychiatry, The Johns Hopkins University School of Medicine, CMSC 8-121, Baltimore, MD 21287, USA.
| | | | | | | | | | | | | |
Collapse
|