GW170814: A Three-Detector Observation of Gravitational Waves from a Binary Black Hole Coalescence

On August 14, 2017 at 10∶30:43 UTC, the Advanced Virgo detector and the two Advanced LIGO detectors coherently observed a transient gravitational-wave signal produced by the coalescence of two stellar mass black holes, with a false-alarm rate of ≲1 in 27 000 years. The signal was observed with a three-detector network matched-filter signal-to-noise ratio of 18. The inferred masses of the initial black holes are 30.5_{-3.0}^{+5.7}M_{⊙} and 25.3_{-4.2}^{+2.8}M_{⊙} (at the 90% credible level). The luminosity distance of the source is 540_{-210}^{+130}  Mpc, corresponding to a redshift of z=0.11_{-0.04}^{+0.03}. A network of three detectors improves the sky localization of the source, reducing the area of the 90% credible region from 1160   deg^{2} using only the two LIGO detectors to 60  deg^{2} using all three detectors. For the first time, we can test the nature of gravitational-wave polarizations from the antenna response of the LIGO-Virgo network, thus enabling a new class of phenomenological tests of gravity.

Stability of nano-sized permethrin in its colloidal state and its effect on the physiological and biochemical profile of Culex tritaeniorhynchus larvae

The occurrence of pesticidal pollution in the environment and the resistance in the mosquito species makes an urge for the safer and an effective pesticide. Permethrin, a poorly water-soluble pyrethroid pesticide, was formulated into a hydrodispersible nanopowder through rapid solvent evaporation of pesticide-loaded oil in water microemulsion. Stability studies confirmed that the nanopermethrin dispersion was stable in paddy field water for 5 days with the mean particle sizes of 175.3 ± 0.75 nm and zeta potential of -30.6 ± 0.62 mV. The instability rate of the nanopermethrin particles was greater in alkaline (pH 10) medium when compared with the neutral (pH 7) and acidic (pH 4) dispersion medium. The colloidal dispersion at 45°C was found to be less stable compared with the dispersions at 25 and 5°C. The 12- and 24-h lethal indices (LC50) for nanopermethrin were found to be 0.057 and 0.014 mg l-1, respectively. These results were corroborative with the severity of damages observed in the mosquito larvae manifested in epithelial cells and the evacuation of the midgut contents. Further, the results were substantiated by the decrease in cellular biomolecules and biomarker enzyme activity in nanopermethrin treated larvae when compared to bulk and control treatment.

Respiratory-syncytial-virus- and rhinovirus-related bronchiolitis in children aged <2 years in an English district general hospital

BACKGROUND

Bronchiolitis is the most common reason for hospitalization in young children. In addition to respiratory syncytial virus (RSV), other viruses have been increasingly implicated. Guidance on testing has also changed.

AIMS

To compare clinicopathological outcomes in young children admitted with bronchiolitis due to RSV in comparison with rhinovirus (RV), and identify associated risk/epidemiological factors.

METHODS

Children aged less than two years admitted to hospital with a clinical diagnosis of bronchiolitis with positive results for either RSV or RV were included in this study. Polymerase-chain-reaction-negative cases using an extended respiratory virus panel served as a control group. Retrospective data were collected on sex, risk factors, respiratory support, intravenous fluids and antibiotics. Outcomes such as length of stay (LOS) and need for transfer to the high-dependency unit/paediatric intensive care unit were included.

FINDINGS

Two hundred and twenty-seven out of 437 nasopharyngeal aspirate samples were positive for either RSV (N = 162) or RV (N = 65). The median age of cases was three months and 75% had at least one risk factor. Risk factors were higher in the RV group (P = 0.004). RV accounted for the majority of cases outside the RSV season (P < 0.01). RV-associated bronchiolitis had a longer LOS (more than seven days) (P < 0.05) and increased need for chest X-rays and/or antibiotics (P < 0.05). Use of intravenous fluids and respiratory support were higher in the RV group, but the difference was not significant.

CONCLUSIONS

RV is the second most common pathogen associated with bronchiolitis and is isolated all year round. This may be important in those with risk factors resulting in prolonged LOS. Further research is necessary to establish the exact role of RV in this common condition, particularly outside the traditional RSV season.

Nanoscale adhesion and sliding on biased semiconductors

We present experimental and theoretical results on controlling nanoscale sliding friction and adhesion by electric fields on model contacts realized by bringing a conductive atomic force microscope tip into contact with the surface of a silicon-oxide/silicon wafer. We find that applying a bias voltage on silicon (or on the conductive tip) enables a noticeable control of the sliding forces. Two electrostatic interactions are identified as being relevant for the friction variation as a function of applied voltage. The first is a short-range electrostatic interaction between opposite charges localized at oxide-silicon/silicon and tip/silicon-oxide interfaces. This attractive interaction results from the high capacity of the oxide-semiconductor interface to change its charge density in response to a bias voltage. Various regimes of charging resulting from silicon electronic bands' alignment and deformation are evidenced. We mainly focused here on the strong charge accumulation and inversion domains. The second longer-range electrostatic interaction is between the voltage-induced bulk and surface charges of both tip and sample. This interaction decreases very slowly with the distance between tip and silicon surface, i.e. oxide thickness, and can be attractive or repulsive depending on voltage polarity. Our results demonstrate the possibility of controlling nanoscale friction/adhesion in nanoscale contacts involving semiconductors. These results are relevant for the operation of nanoscale devices or for on-surface nanomanipulation of metallic nanoparticles. We model the experimental results by adding an electrostatic energy contribution to the tip-surface binding energy, which translates into an increase or decrease of the normal force and ultimately of the sliding friction.

Terrestrial water load and groundwater fluctuation in the Bengal Basin

Groundwater-level fluctuations represent hydraulic responses to changes in groundwater storage due to aquifer recharge and drainage as well as to changes in stress that include water mass loading and unloading above the aquifer surface. The latter 'poroelastic' response of confined aquifers is a well-established phenomenon which has been demonstrated in diverse hydrogeological environments but is frequently ignored in assessments of groundwater resources. Here we present high-frequency groundwater measurements over a twelve-month period from the tropical, fluvio-deltaic Bengal Aquifer System (BAS), the largest aquifer in south Asia. The groundwater level fluctuations are dominated by the aquifer poroelastic response to changes in terrestrial water loading by processes acting over periods ranging from hours to months; the effects of groundwater flow are subordinate. Our measurements represent the first direct, quantitative identification of loading effects on groundwater levels in the BAS. Our analysis highlights the potential limitations of hydrogeological analyses which ignore loading effects in this environment. We also demonstrate the potential for employing poroelastic responses in the BAS and across other tropical fluvio-deltaic regions as a direct, in-situ measure of changes in terrestrial water storage to complement analyses from the Gravity and Climate Experiment (GRACE) mission but at much higher resolution.

Abstract P1-02-06: Serial monitoring of circulating tumor DNA in patients with metastatic breast cancer

Background: For patients with MBC, there is currently no evidence that changing therapy on the basis of biomarker results improves outcome. Clinical benefit of treatment is defined as complete response, objective response, or stable disease as determined by RECIST criteria on radiological evaluation. Serial measurements of serum biomarkers such as CA2729 and CTCs have proven unsuccessful in predicting clinical benefit. Circulating tumor DNA(ctDNA) has emerged as a potential biomarker that may predict response to therapy or progression of disease. The present retrospective study was conducted to evaluate the relationship between change in ctDNA with clinical benefit determined by clinical and radiological evaluations of patients with MBC patients.

Methods: We conducted a retrospective, single-institutional study to determine if serial monitoring of ctDNA allele frequency levels predict clinical benefit of a treatment. 55 patients with measurable MBC who had serial monitoring of ctDNA between August 2014 and May 2016 were included. The median age was 55.9 (27–94) years). Clinical outcomes were determined as per standard guidelines. The analysis was performed on all cases that had serial measurements of ctDNA with no change in therapy in between and the repeat blood draw was done within 30 days of repeat radiographic evaluation. The dataset contained 125 observations from 48 unique patients. The relationship between the change in ctDNA and clinical benefit was analyzed using a generalized linear model with a random subject effect to account for the intrapatient dependence occurring from obtaining multiple evaluations from the same patient. A logit link function was used akin to logistic regression and a compound symmetric correlation structure was assumed.

Results: 68.8% of the cases were hormone receptor-positive, 18.8% HER2-positive, and 27.1% TNBC. The treatments received were 58.4% hormonal therapy, 31.2% chemotherapy, 26.4% included anti-HER2 therapy, 2 cases were on targeted therapy, and 1 case was not on any treatment. Three patients had stage 4 disease in complete remission. ctDNA analysis was repeated on average 4 days prior to radiological evaluation. The average time between repeat assessments was 108.5 days. 93% of the patients had a genomic alteration detected at some point during their course of disease. The most common mutations detected were TP53 41.7%, PIK3CA 35.4%, ESR1 18.8%, and ERBB2 amplifications 6.3%. A dichotomized change in ctDNA is a significant predictor of clinical benefit (p &lt; 0.0001). The intrapatient correlation is estimated to be 0.273 for the transformed variable. The model yields a predicted probability of clinical benefit of 26.9% when the increase in ctDNA is greater than or equal to 0.5 and when the increase in ctDNA is less than 0.5, the a predicted probability of clinical benefit is 78.4%. The concordance of change in ctDNA and change in CA 27-29 was 76.2%.

Conclusions: Serial evaluation of serum ctDNA may be useful to evaluate molecular response to treatment which may correlate with clinical benefit and potentially guide treatment decisions. Early indication that a chosen therapy is not effective may lead to avoidance of overtreatment and initiation of an alternative regimen. Further, prospective studies are needed.

Citation Format: Patel A, Mukherjee A, Hwang D, Ensor J, Patel TA, Chang JC, Rodriguez AA. Serial monitoring of circulating tumor DNA in patients with metastatic breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-02-06.

Improved frame-based estimation of head motion in PET brain imaging

PURPOSE

Head motion during PET brain imaging can cause significant degradation of image quality. Several authors have proposed ways to compensate for PET brain motion to restore image quality and improve quantitation. Head restraints can reduce movement but are unreliable; thus the need for alternative strategies such as data-driven motion estimation or external motion tracking. Herein, the authors present a data-driven motion estimation method using a preprocessing technique that allows the usage of very short duration frames, thus reducing the intraframe motion problem commonly observed in the multiple frame acquisition method.

METHODS

The list mode data for PET acquisition is uniformly divided into 5-s frames and images are reconstructed without attenuation correction. Interframe motion is estimated using a 3D multiresolution registration algorithm and subsequently compensated for. For this study, the authors used 8 PET brain studies that used F-18 FDG as the tracer and contained minor or no initial motion. After reconstruction and prior to motion estimation, known motion was introduced to each frame to simulate head motion during a PET acquisition. To investigate the trade-off in motion estimation and compensation with respect to frames of different length, the authors summed 5-s frames accordingly to produce 10 and 60 s frames. Summed images generated from the motion-compensated reconstructed frames were then compared to the original PET image reconstruction without motion compensation.

RESULTS

The authors found that our method is able to compensate for both gradual and step-like motions using frame times as short as 5 s with a spatial accuracy of 0.2 mm on average. Complex volunteer motion involving all six degrees of freedom was estimated with lower accuracy (0.3 mm on average) than the other types investigated. Preprocessing of 5-s images was necessary for successful image registration. Since their method utilizes nonattenuation corrected frames, it is not susceptible to motion introduced between CT and PET acquisitions.

CONCLUSIONS

The authors have shown that they can estimate motion for frames with time intervals as short as 5 s using nonattenuation corrected reconstructed FDG PET brain images. Intraframe motion in 60-s frames causes degradation of accuracy to about 2 mm based on the motion type.

Pharmacokinetics of isoniazid, rifampicin, pyrazinamide and ethambutol in HIV-infected Indian children

SETTING

Co-infection with the human immunodeficiency virus (HIV) may lead to inadequate plasma concentrations of anti-tuberculosis drugs in children with tuberculosis (TB).

OBJECTIVE

To describe the influence of HIV infection on the pharmacokinetics of isoniazid, rifampicin, pyrazinamide and ethambutol in children.

DESIGN

Prospective drug estimation study in two cohorts of children: HIV-infected (n = 24) and non-HIV-infected (n = 32) with TB. Dosages used were based on earlier World Health Organization recommendations. All four drugs were estimated simultaneously using liquid chromatography mass spectrometry.

RESULTS

The HIV-TB co-infected children had a mean age of 105.9 months (standard deviation 43.1); there were 10 girls (41.7%). The maximum plasma concentration (Cmax), time taken to achieve Cmax, area under curve from 0-4 h and 2 h concentrations of isoniazid (INH), rifampicin (RMP) and pyrazinamide (PZA) were not affected by the HIV status of the children. Ethambutol (EMB) concentrations were lower in HIV-TB co-infected children. Inadequate 2 h concentrations of INH, RMP and EMB were found in the majority of the children in both groups. PZA concentrations were adequate in almost all children. Younger age and lower dose were associated with lower 2 h concentrations of INH and RMP.

CONCLUSION

Inadequate concentrations of INH, RMP and EMB in both HIV-TB-infected and non-HIV-infected children provide support for the recently revised recommended doses of INH and RMP. EMB levels were lower in HIV-infected children; however, more studies are needed to validate this observation.

Spastic quadriparesis due to pathological fracture of odontoid secondary to carcinoma prostate: A rare presentation

Prostate carcinoma presenting as symptomatic metastases to atlantoaxial spine is extremely rare. Spastic quadriparesis due to pathological fracture of odontoid as the only initial manifestation without symptoms of primary malignancy is rarer still. We report a 64-year-old male who presented with progressive spastic quadriparesis along with urinary retention of 3 weeks duration. Computed tomography and magnetic resonance imaging cervical spine and craniovertebral junction showed type III pathological fracture of odontoid with anterior translation of C1 with spinal cord compression. Biopsy from an enlarged prostate showed adenocarcinoma of prostate. The patient was managed conservatively from neurological aspect as he refused for any surgical intervention.

Hydrogeological typologies of the Indo-Gangetic basin alluvial aquifer, South Asia

The Indo-Gangetic aquifer is one of the world's most important transboundary water resources, and the most heavily exploited aquifer in the world. To better understand the aquifer system, typologies have been characterized for the aquifer, which integrate existing datasets across the Indo-Gangetic catchment basin at a transboundary scale for the first time, and provide an alternative conceptualization of this aquifer system. Traditionally considered and mapped as a single homogenous aquifer of comparable aquifer properties and groundwater resource at a transboundary scale, the typologies illuminate significant spatial differences in recharge, permeability, storage, and groundwater chemistry across the aquifer system at this transboundary scale. These changes are shown to be systematic, concurrent with large-scale changes in sedimentology of the Pleistocene and Holocene alluvial aquifer, climate, and recent irrigation practices. Seven typologies of the aquifer are presented, each having a distinct set of challenges and opportunities for groundwater development and a different resilience to abstraction and climate change. The seven typologies are: (1) the piedmont margin, (2) the Upper Indus and Upper-Mid Ganges, (3) the Lower Ganges and Mid Brahmaputra, (4) the fluvially influenced deltaic area of the Bengal Basin, (5) the Middle Indus and Upper Ganges, (6) the Lower Indus, and (7) the marine-influenced deltaic areas.

Essential oil micro- and nanoemulsions: promising roles in antimicrobial therapy targeting human pathogens

Antimicrobial resistance is a major health concern worldwide. A narrowing of the antibiotic development pipeline and a resurgence in public opinion towards 'natural' therapies have renewed the interest in using essential oils as antimicrobial agents. The drawbacks of bulk dosing of essential oils can be mitigated by formulating them as micro- and nanoemulsions. These emulsions have an added advantage as they are in the nanometre size range whose thermodynamic properties enable them to be used as an effective drug delivery system. This review describes the current work on the antimicrobial activities of essential oil micro- and nanoemulsions and their role as drug delivery vehicles.

Liposomal Doxorubicin in Breast Cancer

Drug-delivery carriers represent an important step in the development of targeted therapy. Encapsulation of drug into liposomes represents such a carrier, and helps to minimize side effects of conventional doxorubicin by improving the tumor-specific biodistribution profile. We review the development of the two liposomal doxorubicin formulations, pegylated liposomal doxorubicin and liposomal-encapsulated doxorubicin citrate from reconstitution and comparative pharmacokinetics to pivotal Phase III trials, with special emphasis in breast cancer. The relative differences in the toxicity profile can be attributed to their differences in the liposomal formulations. Areas of special interest include the reduction in cardiac toxicities and the improved efficacy, such as in the treatment of ovarian cancer. These improvements have also increased the potential of these liposomal formulations of doxorubicin for combination and sequencing with other biological and cytotoxic agents for clinical benefit.

Multimodal characterization of radiologically detectable lung lesions

Diagnosing radiologically detectable lung lesions on the basis of cyto/histopathological staining often suffers from ambiguity, leading to faulty detection of lung diseases, especially cancer. Present study attempted to perform a multimodal characterzation of clinical samples from patients with radiologically detected lung lesions, in order to classify diseases with higher precision. The study included analysing nuclear morphometric and intensity based differences between benign and malignant lung lesions in a quantitative way. Simultaneous analysis of serum samples taken from similar sets of patients was performed by Fourier transform infra red (FTIR) spectroscopy which provided differential global biochemical insights of normal and diseased states. Both nuclear and serum biochemical features were helpful in accomplishing high classification accuracy in distinguishing benign and different malignant cases.

Trigeminal Autonomic Cephalgias and Variants: Clinical Profile in Indian Patients

The present study summarizes the authors' experience of the clinical profile of short-lasting trigeminal autonomic cephalgias (TAC) in Indian patients. Over a period of 17 years a total of 41 cases of episodic cluster headache, seven cases of chronic cluster headache, six cases of variant cluster headache, three cases of paroxysomal hemicrania, and a single case of SUNCT syndrome were encountered. TACs appear to be rare in Indian patients and cluster headache seems to be exclusively a disease of men. The present report is to the best of our knowledge the first of its kind to be reported from India.

Migraine Pain Location at Onset and During Established Headaches in Children and Adolescents: A Clinic-Based Study from Eastern India

Literature documenting the location of pain at onset of migraine attacks and during established headaches in children and adolescents is sparse. Through a prospective study (2003–2005) of 200 children with migraine (ICHD-2: 1.1 and 1.2.1), we set out to document (i) the site of onset of pain and (ii) the location of pain during established attacks (on >50% of occasions) through semistructured interviews of patients and parents. Of the 200 children, the male:female ratio was 118 : 82 (1 : 0.69), the age range was 7–15 years (mean 11.8 years) and the duration of migraine 6 months to 4 years (mean 1.6 years). Ninety-three percent of subjects were ethnic Bengalis from the eastern Indian state of West Bengal, capital city Calcutta. Migraine types were: 1.1, 197 (98.5%); 1.2.1, three (1.5%). Location of pain at onset: 20.5% of subjects had unilateral onset; of these, 26.8% had eye pain, 65.9% frontal and 12.3% temporal pain. Thirty-three percent had bilateral location of pain, mostly bifrontal or ocular. None had vertex onset pain. However, in 35% of subjects, pain was holocranial at onset. Only 11.5% experienced pain in the occipito-cervical region at onset. Location of established headaches: in 53.7% of subjects with unilateral onset, headaches subsequently became holocranial. Hemicranial headaches occurred in only 19.5%. Of bilateral onset pains, 57.8% also became holocranial subsequently. In all, 73.5% of children ultimately experienced holocranial headaches. This study documents pain location at onset and during established headaches in children with migraine largely from a specific ethnic group.