Human subcortical brain asymmetries in 15,847 people worldwide reveal effects of age and sex

The two hemispheres of the human brain differ functionally and structurally. Despite over a century of research, the extent to which brain asymmetry is influenced by sex, handedness, age, and genetic factors is still controversial. Here we present the largest ever analysis of subcortical brain asymmetries, in a harmonized multi-site study using meta-analysis methods. Volumetric asymmetry of seven subcortical structures was assessed in 15,847 MRI scans from 52 datasets worldwide. There were sex differences in the asymmetry of the globus pallidus and putamen. Heritability estimates, derived from 1170 subjects belonging to 71 extended pedigrees, revealed that additive genetic factors influenced the asymmetry of these two structures and that of the hippocampus and thalamus. Handedness had no detectable effect on subcortical asymmetries, even in this unprecedented sample size, but the asymmetry of the putamen varied with age. Genetic drivers of asymmetry in the hippocampus, thalamus and basal ganglia may affect variability in human cognition, including susceptibility to psychiatric disorders

Monitor Unit Verification for Radiotherapy Irregular Fields Based On the Clarkson Method Combined With In-House MLC Shaper Software

Introduction: In the present scenario, high precision-radiotherapy is delivered through Linear accelerators in which the dose delivery is achieved by delivering the proper monitor unit (MU). Treatment planning for the patients is carried out through treatment planning systems (TPS) in which the precise computation of MU is crucial. This TPS - calculated MU has to be verified using manual calculations for accurate dose delivery. In this study, we incorporated our in-house developed multi leaf collimator(MLC) shaper software and the well-known Clarkson method to compare the calculated MUs to the TPS-generated MUs.Material and Methods: Conformal treatment plans of various sites of 30 patients were randomly selected containing different MLC-shaped field sizes. All the fields were shaped using MLC (leaf width of 1cm, 40 pairs) in the TPS. MLC log files were exported and fed into the in-house shaper software to get crucial inputs for the Clarkson-based calculation. The Tissue Maximum Ratio(TMR) & Scatter Maximum ratio(SMR) were utilized in our investigation. The Clarkson MU calculation was compared with the TPS calculation method. Paired t-test was performed for the statistical significance.Results: The Clarkson method-based calculated had significant differences for all the esophageal cancers (p<0.05); however no significant difference was found in the other sites.Conclusion: The compared MUs were within the acceptable deviation with the TPS for Head & Neck, Prostrate and Cervical cancer. The estimated MUs had significant difference in non-homogenous medium. The shaper software can be further enhanced to receive MLC log files from the TPS

Multi-messenger observations of a binary neutron star merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

Search for Dark Matter and Supersymmetry with a Compressed Mass Spectrum in the Vector Boson Fusion Topology in Proton-Proton Collisions at root s=8 TeV

Peer reviewe

A STUDY ON PATTERN OF ALCOHOL USE USING AUDIT AMONG THE COLLEGE STUDENTS IN A MEDICAL COLLEGE OF NORTH INDIA

ABSTRACT Background: Alcohol and other substance use by medical students poses risks to them and can also have serious consequences on their effectiveness and fitness to practise as tomorrow&apos;s doctors. The aim of the study was to find out the prevalence of alcohol use among the undergraduates of Rohilkhand Medical College, Bareilly and the factors affecting its use

Shear Forces during Blast, Not Abrupt Changes in Pressure Alone, Generate Calcium Activity in Human Brain Cells

Blast-Induced Traumatic Brain Injury (bTBI) describes a spectrum of injuries caused by an explosive force that results in changes in brain function. The mechanism responsible for primary bTBI following a blast shockwave remains unknown. We have developed a pneumatic device that delivers shockwaves, similar to those known to induce bTBI, within a chamber optimal for fluorescence microscopy. Abrupt changes in pressure can be created with and without the presence of shear forces at the surface of cells. In primary cultures of human central nervous system cells, the cellular calcium response to shockwaves alone was negligible. Even when the applied pressure reached 15 atm, there was no damage or excitation, unless concomitant shear forces, peaking between 0.3 to 0.7 Pa, were present at the cell surface. The probability of cellular injury in response to a shockwave was low and cell survival was unaffected 20 hours after shockwave exposure

A Two-year Outcome of Various Techniques of Discectomy On Complications: A Multicentric Retrospective Study

Objective Various techniques of performing lumbar discectomy are prevalent, each having its rationale and claimed benefits. The authors ventured to assess the total complication rate of lumbar discectomy as well as the complication rates of individual complications, namely CSF leaks, superficial wound infections, deep wound infections, recurrence rates, re-operation rates, and wrong level surgery. Methods This was a retrospective study of patients operated using open discectomy (OD), microdiscectomy (MD), microendoscopic discectomy (MED), interlaminar endoscopic lumbar discectomy (IELD), transforaminal endoscopic lumbar discectomy (TELD), and Destandau techniques (DT) with a minimum follow-up of 2 years. The inclusion criteria were age>15 years, failed conservative treatment for 4-6 weeks, and the involvement of a single lumbar level. Results There is no statistically significant association between surgical technique and complications. The total complication rate was 12.89% in 946 operated cases. The most common complication was recurrence (5.81%), followed by re-operation (3.69%), CSF leak (1.90%), wrong level surgery (0.63%), superficial infection (0.52%) and deep infection (0.31%). There were minor differences in the incidence of complications between techniques. Conclusion This is the first study to compare the complication rates of all the prevalent discectomy techniques across the globe in 946 patients. Although there were minor differences in incidences of complications between individual techniques, there was no statistical significance. The various rates of individual complications provide a reference value for future studies related to complications following discectomy

Anti-Bacterial Effects of Poly-N-Acetyl-Glucosamine Nanofibers in Cutaneous Wound Healing: Requirement for Akt1

Treatment of cutaneous wounds with poly-N-acetyl-glucosamine nanofibers (sNAG) results in increased kinetics of wound closure in diabetic animal models, which is due in part to increased expression of several cytokines, growth factors, and innate immune activation. Defensins are also important for wound healing and anti-microbial activities. Therefore, we tested whether sNAG nanofibers induce defensin expression resulting in bacterial clearance.The role of sNAG in defensin expression was examined using immunofluoresence microscopy, pharmacological inhibition, and shRNA knockdown in vitro. The ability of sNAG treatment to induce defensin expression and bacterial clearance in WT and AKT1-/- mice was carried out using immunofluoresent microscopy and tissue gram staining. Neutralization, using an antibody directed against β-defensin 3, was utilized to determine if the antimicrobial properties of sNAG are dependent on the induction of defensin expression.sNAG treatment causes increased expression of both α- and β-type defensins in endothelial cells and β-type defensins in keratinocytes. Pharmacological inhibition and shRNA knockdown implicates Akt1 in sNAG-dependent defensin expression in vitro, an activity also shown in an in vivo wound healing model. Importantly, sNAG treatment results in increased kinetics of wound closure in wild type animals. sNAG treatment decreases bacterial infection of cutaneous wounds infected with Staphylococcus aureus in wild type control animals but not in similarly treated Akt1 null animals. Furthermore, sNAG treatment of S. aureus infected wounds show an increased expression of β-defensin 3 which is required for sNAG-dependent bacterial clearance. Our findings suggest that Akt1 is involved in the regulation of defensin expression and the innate immune response important for bacterial clearance. Moreover, these findings support the use of sNAG nanofibers as a novel method for enhancing wound closure while simultaneously decreasing wound infection

Sodium Selenide Toxicity Is Mediated by O2-Dependent DNA Breaks

Hydrogen selenide is a recurrent metabolite of selenium compounds. However, few experiments studied the direct link between this toxic agent and cell death. To address this question, we first screened a systematic collection of Saccharomyces cerevisiae haploid knockout strains for sensitivity to sodium selenide, a donor for hydrogen selenide (H2Se/HSe−/Se2−). Among the genes whose deletion caused hypresensitivity, homologous recombination and DNA damage checkpoint genes were over-represented, suggesting that DNA double-strand breaks are a dominant cause of hydrogen selenide toxicity. Consistent with this hypothesis, treatment of S. cerevisiae cells with sodium selenide triggered G2/M checkpoint activation and induced in vivo chromosome fragmentation. In vitro, sodium selenide directly induced DNA phosphodiester-bond breaks via an O2-dependent reaction. The reaction was inhibited by mannitol, a hydroxyl radical quencher, but not by superoxide dismutase or catalase, strongly suggesting the involvement of hydroxyl radicals and ruling out participations of superoxide anions or hydrogen peroxide. The •OH signature could indeed be detected by electron spin resonance upon exposure of a solution of sodium selenide to O2. Finally we showed that, in vivo, toxicity strictly depended on the presence of O2. Therefore, by combining genome-wide and biochemical approaches, we demonstrated that, in yeast cells, hydrogen selenide induces toxic DNA breaks through an O2-dependent radical-based mechanism