Introduction of external magnetic fields in entropic moment modelling for radiotherapy

One of the big challenges of the emerging MRI-guided radiotherapy is the prediction of an external magnetic field effect on the deposited dose induced by a beam of charged particles. In this paper, we present the results of the implementation of the Lorentz force in the deterministic M1 model. The validation of our code is performed by comparisons with the Monte-Carlo code FLUKA. The relevant examples show a significant modification of the shape of dose deposition volume induced by the external magnetic field in presence of heterogeneities. A gamma-index analysis 3%/3mm shows a good agreement of our model with FLUKA simulations.

GW170104: Observation of a 50-Solar-Mass Binary Black Hole Coalescence at Redshift 0.2

We describe the observation of GW170104, a gravitational-wave signal produced by the coalescence of a pair of stellar-mass black holes. The signal was measured on January 4, 2017 at 10∶11:58.6 UTC by the twin advanced detectors of the Laser Interferometer Gravitational-Wave Observatory during their second observing run, with a network signal-to-noise ratio of 13 and a false alarm rate less than 1 in 70 000 years. The inferred component black hole masses are 31.2_{-6.0}^{+8.4}M_{⊙} and 19.4_{-5.9}^{+5.3}M_{⊙} (at the 90% credible level). The black hole spins are best constrained through measurement of the effective inspiral spin parameter, a mass-weighted combination of the spin components perpendicular to the orbital plane, χ_{eff}=-0.12_{-0.30}^{+0.21}. This result implies that spin configurations with both component spins positively aligned with the orbital angular momentum are disfavored. The source luminosity distance is 880_{-390}^{+450}  Mpc corresponding to a redshift of z=0.18_{-0.07}^{+0.08}. We constrain the magnitude of modifications to the gravitational-wave dispersion relation and perform null tests of general relativity. Assuming that gravitons are dispersed in vacuum like massive particles, we bound the graviton mass to m_{g}≤7.7×10^{-23}  eV/c^{2}. In all cases, we find that GW170104 is consistent with general relativity.

Upper Limits on the Stochastic Gravitational-Wave Background from Advanced LIGO's First Observing Run

A wide variety of astrophysical and cosmological sources are expected to contribute to a stochastic gravitational-wave background. Following the observations of GW150914 and GW151226, the rate and mass of coalescing binary black holes appear to be greater than many previous expectations. As a result, the stochastic background from unresolved compact binary coalescences is expected to be particularly loud. We perform a search for the isotropic stochastic gravitational-wave background using data from Advanced Laser Interferometer Gravitational Wave Observatory's (aLIGO) first observing run. The data display no evidence of a stochastic gravitational-wave signal. We constrain the dimensionless energy density of gravitational waves to be Ω_{0}<1.7×10^{-7} with 95% confidence, assuming a flat energy density spectrum in the most sensitive part of the LIGO band (20-86 Hz). This is a factor of ∼33 times more sensitive than previous measurements. We also constrain arbitrary power-law spectra. Finally, we investigate the implications of this search for the background of binary black holes using an astrophysical model for the background.

Directional Limits on Persistent Gravitational Waves from Advanced LIGO's First Observing Run

We employ gravitational-wave radiometry to map the stochastic gravitational wave background expected from a variety of contributing mechanisms and test the assumption of isotropy using data from the Advanced Laser Interferometer Gravitational Wave Observatory's (aLIGO) first observing run. We also search for persistent gravitational waves from point sources with only minimal assumptions over the 20-1726 Hz frequency band. Finding no evidence of gravitational waves from either point sources or a stochastic background, we set limits at 90% confidence. For broadband point sources, we report upper limits on the gravitational wave energy flux per unit frequency in the range F_{α,Θ}(f)<(0.1-56)×10^{-8}    erg cm^{-2} s^{-1} Hz^{-1}(f/25  Hz)^{α-1} depending on the sky location Θ and the spectral power index α. For extended sources, we report upper limits on the fractional gravitational wave energy density required to close the Universe of Ω(f,Θ)<(0.39-7.6)×10^{-8}  sr^{-1}(f/25  Hz)^{α} depending on Θ and α. Directed searches for narrowband gravitational waves from astrophysically interesting objects (Scorpius X-1, Supernova 1987 A, and the Galactic Center) yield median frequency-dependent limits on strain amplitude of h_{0}<(6.7,5.5,  and  7.0)×10^{-25}, respectively, at the most sensitive detector frequencies between 130-175 Hz. This represents a mean improvement of a factor of 2 across the band compared to previous searches of this kind for these sky locations, considering the different quantities of strain constrained in each case.

Cross-cultural validity of the German version of the Pediatric Evaluation of Disability Inventory (PEDI-G)-a Rasch model application

AIM

The aim of this study was to evaluate the cross-cultural validity of the German version of the Pediatric Evaluation of Disability Inventory (PEDI-G) when used in Austria, Germany and Switzerland.

METHOD

A total of 118 girls and 144 boys participated in this study; 198 of the children (75.6%) had a developmental disability and 64 (24.4%) were without a known disability. The mean age was four years (range 11 months to 10 years and six months, SD 1.91). Item goodness of fit, differential item functioning (DIF) and differential test functioning (DTF) were evaluated by use of a Rasch model.

RESULTS

Twenty-four (11.6%) out of 206 items of the Functional Skills Scale and one (5%) out of 20 items of the Caregiver Assistance Scale demonstrated misfit according to the Rasch model. Thirty-four (16.5%) out of 206 items of the Functional Skills Scale and no item from the Caregiver Assistance Scale demonstrated DIF. Almost half (46%) of the items demonstrating misfit also demonstrated DIF, indicating an association between them. The DIF by country only demonstrated a minimal impact on the person measures of the PEDI-G.

INTERPRETATION

Even though some items did not meet the statistical and clinical criteria set, the PEDI-G can be used, on a preliminary basis as a valid tool to measure activities of daily living of children with and without a disability in these countries. Further larger studies are needed to evaluate more psychometric item properties of the PEDI-G in relation to context.

[Infant respiratory distress revealing Jeune syndrome]

Jeune syndrome (asphyxiating thoracic dystrophy) is a rare autosomal recessive osteochondrodysplasia with a variable degree of severity, clinically characterized by respiratory distress with a narrow chest and limb shortness. The reported incidence is one to five in 500,000 live births. Most patients develop severe respiratory failure during the first 2 years of life, leading to death in 60-80 % of cases. Survivors may suffer from renal, hepatic, or pancreatic complications. Expanding thoracic surgery can be used for severe cases. We describe the case of an 18-month-old boy who developed mild respiratory distress. The patient showed typical radiological features of Jeune syndrome: narrow thorax with short ribs and trident appearance of the pelvis. This case underscores the value of the right interpretation of the chest radiograph of the infant with a respiratory distress syndrome.

Alterations in chromosomal synapses and DNA repair in apoptotic spermatocytes of Mus m. domesticus

We investigated whether apoptotic spermatocytes from the mouse Mus m. domesticus presented alterations in chromosomal synapses and DNA repair. To enrich for apoptotic spermatocytes, the scrotum's temperature was raised by partially exposing animals for 15 min to a 42ºC water bath. Spermatocytes in initial apoptosis were identified in situ by detecting activated Caspase-9.  SYCP1 and SYCP3 were markers for evaluating synapses or the structure of synaptonemal complexes and Rad51 and γH2AX for detecting DNA repair and chromatin remodeling. Apoptotic spermatocytes were concentrated in spermatogenic cycle stages III-IV (50.3%), XI-XII (44.1%) and IX-X (4.2%). Among apoptotic spermatocytes, 48% were in middle pachytene, 44% in metaphase and 6% in diplotene. Moreover, apoptotic spermatocytes showed several structural anomalies in autosomal bivalents, including splitting of chromosomal axes and partial asynapses between homologous chromosomes. gH2AX and Rad51 were atypically distributed during pachytene and as late as diplotene and associated with asynaptic chromatin, single chromosome axes or discontinuous chromosome axes. Among apoptotic spermatocytes at pachytene, 70% showed changes in the structure of synapses, 67% showed changes in gH2AX and Rad51 distribution and 50% shared alterations in both synapses and DNA repair. Our results showed that apoptotic spermatocytes from Mus m. domesticus contain a high frequency of alterations in chromosomal synapses and in the recruitment and distribution of DNA repair proteins. Together, these observations suggest that these alterations may have been detected by meiotic checkpoints triggering apoptosis.

Differences in activities of daily living (ADL) abilities of children across world regions: a validity study of the assessment of motor and process skills

BACKGROUND

One important goal of paediatric occupational therapy services is to improve activities of daily living (ADL) abilities of children. In order to plan and evaluate the effectiveness of targeted interventions, valid assessments are critically needed. The Assessment of Motor and Process Skills (AMPS) is an internationally standardized assessment of ADL performance that has not been validated for use with children in Middle Europe.

AIM

To evaluate for (i) significant differences in mean ADL motor and mean ADL process ability measures among children from Middle Europe compared with children from North America, UK/Republic of Ireland, Nordic countries, Western Europe, Australia/New Zealand and Asia; and (ii) meaningful differences between the international age-normative means of the AMPS and those for children from Middle Europe.

METHOD

We analysed data of children across world regions extracted from the international AMPS database using many-facet Rasch and two-way anova analyses and by estimating contrasts to evaluate for significant group differences.

RESULTS

anova analyses of data for 11 189 children ages 2-15 revealed significant effects for mean ADL motor and ADL process ability by region [F ≥ 15.32, d.f. = (6, 11 091), MSE ≥ 0.20, P < 0.001, ή(2) ≥ 0.008], and age [F ≥ 253.47, d.f. = (13, 11 091), MSE ≥ 0.20, P < 0.001, ή(2) ≥ 0.229], and a significant interaction effect for mean ADL process ability [F = 1.48, d.f. = (78, 11 091), P = 0.004, ή(2) = 0.010]. Out of 168 estimated contrasts between Middle Europe and the other world regions for mean ADL motor and ADL process ability, seven were statistically significant (4.17%), but none exceeded ±1SE from the international means.

CONCLUSION

The AMPS remains free of relevant differences in mean ADL ability measures between Middle Europe and other world regions, indicating that the international age-normative mean values are likely to be applicable to children from Middle Europe. The AMPS can be used internationally to evaluate ADL performance in children and to determine if the child is eligible for occupational therapy services.

Impact of the point spread function on maximum standardized uptake value measurements in patients with pulmonary cancer

Maximum standardized uptake value (SUVmax) from fluorodeoxyglucose (FDG) positron emission tomography (PET) scans is a semi quantitative measure that is increasingly used in the clinical practice for diagnostic and therapeutic response assessment purposes. Technological advances such as the implementation of the point spread function (PSF) in the reconstruction algorithm have led to higher signal to noise ratio and increased spatial resolution. The impact on SUVmax measurements has not been studied in clinical setting. We studied the impact of PSF on SUVmax in 30 consecutive lung cancer patients. SUVmax values were measured on PET-computed tomography (CT) scans reconstructed iteratively with and without PSF (respectively high-definition [HD] and non-HD). HD SUVmax values were significantly higher than non-HD SUVmax. There was excellent correlation between HD and non-HD values. Details of reconstruction and PSF implementation in particular have important consequences on SUV values. Nuclear Medicine physicians and radiologists should be aware of the reconstruction parameters of PET-CT scans when they report or rely on SUV measurements.

Dynamics of cohesin subunits in grasshopper meiotic divisions

The cohesin complex plays a key role for the maintenance of sister chromatid cohesion and faithful chromosome segregation in both mitosis and meiosis. This complex is formed by two structural maintenance of chromosomes protein family (SMC) subunits and two non-SMC subunits: an α-kleisin subunit SCC1/RAD21/REC8 and an SCC3-like protein. Several studies carried out in different species have revealed that the distribution of the cohesin subunits along the chromosomes during meiotic prophase I is not regular and that some subunits are distinctly incorporated at different cell stages. However, the accurate distribution of the different cohesin subunits in condensed meiotic chromosomes is still controversial. Here, we describe the dynamics of the cohesin subunits SMC1α, SMC3, RAD21 and SA1 during both meiotic divisions in grasshoppers. Although these subunits show a similar patched labelling at the interchromatid domain of metaphase I bivalents, SMCs and non-SMCs subunits do not always colocalise. Indeed, SA1 is the only cohesin subunit accumulated at the centromeric region of all metaphase I chromosomes. Additionally, non-SMC subunits do not appear at the interchromatid domain in either single X or B chromosomes. These data suggest the existence of several cohesin complexes during metaphase I. The cohesin subunits analysed are released from chromosomes at the beginning of anaphase I, with the exception of SA1 which can be detected at the centromeres until telophase II. These observations indicate that the cohesin components may be differentially loaded and released from meiotic chromosomes during the first and second meiotic divisions. The roles of these cohesin complexes for the maintenance of chromosome structure and their involvement in homologous segregation at first meiotic division are proposed and discussed.

Abstract P1-15-01: Patterns of granulocyte colony stimulating factor (G-CSF) use in elderly breast cancer (BC) patients receiving myelosuppressive chemotherapy

Background: Febrile neutropenia (FN) is a common and potentially serious complication of myelosuppressive chemotherapy treatment in cancer patients. Oncology guidelines recommend primary G-CSF prophylaxis (PPG) in patients with a high risk of developing FN, which is risk &gt;20% based on myelotoxicity of the regimen itself or from a combination of the therapy, older age, comorbidities and disease characteristics (Lyman Cancer 2011). Current patterns of G-CSF use and FN occurrence among elderly patients receiving myelosuppressive chemotherapy for BC have not been previously reported. To determine this, we performed a retrospective analysis using a subset of the Medicare 5% database.

Methods: The Medicare 5% claims data set (includes a representative 5% systematic sample of Medicare beneficiaries) was used to identify BC patients age 65+ initiating chemotherapy between 7/1/2003 and 6/30/2009. Chemotherapy courses were identified for each patient; only the first course was used for this analysis. Using the National Comprehensive Cancer Network guidelines on Myeloid Growth Factors (NCCN V1.2012), chemotherapy course regimens were classified as high risk (HR) or intermediate risk (IR) for FN. Duration of first cycle was from date of first chemotherapy claim to the chemotherapy claim at day 21 or later, which defined the first day of the second cycle, etc., to a maximum of 9 cycles. First administration of G-CSF [filgrastim (NEUPOGEN®) or pegfilgrastim (Neulasta®)] was classified as either PPG (within first 5 days of first cycle), secondary prophylaxis (within first 5 days of second or subsequent cycles), or reactive (day 6 or later of first or subsequent cycles). FN assessed during the chemotherapy course was defined as hospitalization with a code for neutropenia in any position.

Results: 885 courses with high FN risk and 1046 with IR FN risk were identified. The HR cohort was younger (71.4 vs 74.5 yrs) and had fewer comorbidities than the IR cohort. Selected aspects of G-CSF use patterns are summarized in the table. Among HR courses, 11.8% had ≥1 FN hospitalization and 2.1% had 2+; among IR courses 5.6% had ≥1 and 0.4% had 2+.

Conclusion: NCCN recommends PPG be used with HR regimens and older age (notably &gt;65 yr), an important risk factor for developing severe neutropenic complications. Despite this, PPG was used for elderly breast cancer patients in only 52% of chemotherapy courses with high risk of FN and in 10% of IR courses. More than 10% of patients with a HR regimen had an FN hospitalization. Careful attention to FN risk factors, including regimen and patient age, is needed when planning treatment strategy.

Distribution of repetitive DNAs and the hybrid origin of the red vizcacha rat (Octodontidae)

Great genome size (GS) variations described in desert-specialist octodontid rodents include diploid species ( Octomys mimax and Octodontomys gliroides ) and putative tetraploid species ( Tympanoctomys barrerae and Pipanacoctomys aureus ). Because of its high DNA content, elevated chromosome number, and gigas effect, the genome of T. barrerae is claimed to have resulted from tetraploidy. Alternatively, the origin of its GS has been attributed to the accumulation of repetitive sequences. To better characterize the extent and origin of these repetitive DNA, self-genomic in situ hybridization (self-GISH), whole-comparative genomic hybridization (W-CGH), and conventional GISH were conducted in mitotic and meiotic chromosomes. Self-GISH on T. barrerae mitotic plates together with comparative self-GISH (using its closest relatives) discriminate a pericentromeric and a telomeric DNA fraction. As most of the repetitive sequences are pericentromeric, it seems that the large GS of T. barrerae is not due to highly repeated sequences accumulated along chromosomes arms. W-CGH using red-labeled P. aureus DNA and green-labeled O. mimax DNA simultaneously on chromosomes of T. barrerae revealed a yellow-orange fluorescence over a repetitive fraction of the karyotype. However, distinctive red-only fluorescent signals were also detected at some centromeres and telomeres, indicating closer homology with the DNA sequences of P. aureus. Conventional GISH using an excess of blocking DNA from either P. aureus or O. mimax labeled only a fraction of the T. barrerae genome, indicating its double genome composition. These data point to a hybrid nature of the T. barrerae karyotype, suggesting a hybridization event in the origin of this species.

Apathy and Its Nonpharmacological Treatment in Dementia

Apathy is the most common behavioral symptom in Alzheimer’s disease. Apathy has been defined as a state characterized by simultaneous diminution in the overt behavioral, cognitive, and emotional concomitants of goal-directed behavior. In that sense, apathy refers to impairments in motor, cognitive, and emotional functions. To date, there is little empirical foundation for how these three levels interact in patients suffering from apathy. We describe here neurobiological foundations as well as clinical correlations between the severity of apathy and impairments in motor, cognitive, and emotional functions. Furthermore, we present a literature review of the nonpharmacological treatment options of apathy in dementia. We suggest that focusing on the motor, cognitive, and emotional aspects of apathy may help to implement successful treatment strategies. Multimodal, individualized approaches, including the use of physical activation and biography-based information to motivate dementia patients, seem to be of high relevance.

Chronic norovirus infection in pediatric hematopoietic stem cell transplant recipients: a cause of prolonged intestinal failure requiring intensive nutritional support

Norovirus infection is a major cause of nonbacterial gastroenteritis. In immunocompetent individuals the illness caused by norovirus is mostly self limiting. Excretion of norovirus has been reported to be prolonged in the immunocompromised including adult HSCT recipients. We report a case series of 13 children who received HSCT and required prolonged parenteral and enteral nutrition due to severe gut dysfunction accompanying protracted norovirus excretion that was monitored by RT-PCR. The median duration of viral excretion was 150 days (range 60-380) and the eventual clearance of norovirus from feces was closely associated with donor T cell recovery in the peripheral blood. There was no disease manifestation beyond the gut but the severity and length of norovirus associated illness suggests that HSCT should be delayed where possible in patients excreting the virus prior to conditioning therapy.

Caries control in health service practice

It is suggested that it makes sense for dentists providing care for individual patients to take account of caries risk (as assessed by presentation of active, non-cavitated lesions) when deciding how to allocate time and effort of themselves and their staff. However, there is a question as to how realistic it is to ask the dental team to provide a full diagnostic assessment and all the preventive treatment required for a patient for the payment provided by 1 UDA. It is to be hoped that one or more of the Steele pilots will come up with a practical solution for controlling caries in NHS practice.