Large spin-relaxation anisotropy in bilayer-graphene/WS2 heterostructures

We study spin-transport in bilayer-graphene (BLG), spin-orbit coupled to a tungsten di sulfide (WS$_2$) substrate, and measure a record spin lifetime anisotropy ~40-70, i.e. ratio between the out-of-plane $\tau_{\perp}$ and in-plane spin relaxation time $\tau_{||}$. We control the injection and detection of in-plane and out-of-plane spins via the shape-anisotropy of the ferromagnetic electrodes. We estimate $\tau_{\perp}$ ~ 1-2 ns via Hanle measurements at high perpendicular magnetic fields and via a new tool we develop: Oblique Spin Valve measurements. Using Hanle spin-precession experiments we find a low $\tau_{||}$ ~ 30 ps in the electron-doped regime which only weakly depends on the carrier density in the BLG and conductivity of the underlying WS$_2$, indicating proximity-induced spin-orbit coupling (SOC) in the BLG. Such high $\tau_{\perp}$ and spin lifetime anisotropy are clear signatures of strong spin-valley coupling for out-of-plane spins in BLG/WS$_2$ systems in the presence of SOC, and unlock the potential of BLG/transition metal dichalcogenide heterostructures for developing future spintronic applications.Comment: 19 figures, 13 page

In Vitro Inoculation of Asparagus Officinalis Tissue Culture Shoots with Fusarium Prolifera Tum

Artificially inoculated asparagus tissue culture plantlets with a virulent fungus, Fusarium proliferatum showed signs of infection as early as 4 days after inoculation. Macroscopic observations revealed presence of early symptoms such as necrotic lesions at the affected area and light microscopic examinations clearly revealed the post-penetration events that took place including the destruction of surrounding cells. However, little is known of the hyphal activity or advancement on the host's surface at the initial stage after inoculation. Scanning electron microscopic examination clearly revealed the hyphal advancement on the surface and the mode of entrance into the host tissues beneath. Four days after inoculation, the fungi proceeded to spread out from the inoculation point onto the host surface which eventually developed into a sparse network of both aerial and non-aerial hyphae. Non-aerial hyphae form a network of mycelium that adheres to the surface and it's movement appeared to be oriented towards the stomata. Hyphal penetration occurs more often through the stomata, natural openings or wounds. In some cases, the hyphae crossed over the stomatal opening without entering the host tissues. At places where the cuticle layer is absent or not well developed the hyphae successfully grew in between the epidermal cells into the tissues beneath

Perturbative approach to the structure of rapidly rotating neutron stars

We construct models of rotating stars using the perturbative approach introduced by J. Hartle in 1967, and a set of equations of state proposed to model hadronic interactions in the inner core of neutron stars. We integrate the equations of stellar structure to third order in the angular velocity and show, comparing our results to those obtained with fully non linear codes, to what extent third order corrections are needed to accurately reproduce the moment of inertia of a star which rotates at rates comparable to that of the fastest isolated pulsars.Comment: 17 pages, 5 figures, minor changes to match version accepted by Phys. Rev.

Necessary and sufficient condition for longitudinal magnetoresistance

Since the Lorentz force is perpendicular to the magnetic field, it should not affect the motion of a charge along the field. This argument seems to imply absence of longitudinal magnetoresistance (LMR) which is, however, observed in many materials and reproduced by standard semiclassical transport theory applied to particular metals. We derive a necessary and sufficient condition on the shape of the Fermi surface for non-zero LMR. Although an anisotropic spectrum is a pre-requisite for LMR, not all types of anisotropy can give rise to the effect: a spectrum should not be separable in any sense. More precisely, the combination $k_{\rho}v_{\phi}/v_{\rho}$, where $k_\rho$ is the radial component of the momentum in a cylindrical system with the z-axis along the magnetic field and $v_{\rho} (v_{\phi}$) is the radial (tangential) component of the velocity, should depend on the momentum along the field. For some lattice types, this condition is satisfied already at the level of nearest-neighbor hopping; for others, the required non-separabality occurs only if next-to-nearest-neighbor hopping is taken into account.Comment: 7 pages, 2 figure

Outbreak of gastroenteritis caused by Yersinia pestis in Afghanistan.

Plague, which is most often caused by the bite of Yersinia pestis-infected fleas, is a rapidly progressing, serious disease that can be fatal without prompt antibiotic treatment. In late December 2007, an outbreak of acute gastroenteritis occurred in Nimroz Province of southern Afghanistan. Of the 83 probable cases of illness, 17 died (case fatality 20·5%). Being a case was associated with consumption or handling of camel meat (adjusted odds ratio 4·4, 95% confidence interval 2·2-8·8, P<0·001). Molecular testing of patient clinical samples and of tissue from the camel using PCR/electrospray ionization-mass spectrometry revealed DNA signatures consistent with Yersinia pestis. Confirmatory testing using real-time PCR and immunological seroconversion of one of the patients confirmed that the outbreak was caused by plague, with a rare gastrointestinal presentation. The study highlights the challenges of identifying infectious agents in low-resource settings; it is the first reported occurrence of plague in Afghanistan

The HI content of the Eridanus group of galaxies

The HI content of galaxies in the Eridanus group is studied using the GMRT observations and the HIPASS data. A significant HI deficiency up to a factor of 2-3 is observed in galaxies in the high galaxy density regions. The HI deficiency in galaxies is observed to be directly correlated with the local projected galaxy density, and inversely correlated with the line-of-sight radial velocity. Furthermore, galaxies with larger optical diameters are predominantly in the lower galaxy density regions. It is suggested that the HI deficiency in Eridanus is due to tidal interactions. In some galaxies, evidences of tidal interactions are seen. An important implication is that significant evolution of galaxies can take place in the group environment. In the hierarchical way of formation of clusters via mergers of groups, a fraction of the observed HI deficiency in clusters could have originated in groups. The co-existence of S0's and severely HI deficient galaxies in the Eridanus group suggests that galaxy harassment is likely to be an effective mechanism for transforming spirals to S0's.Comment: 21 pages; Accepted for publication in Journal of Astroph. & Astron. March, 200

Effect of Global Warming Scenarios on Carotenoid Pigments Gracilaria changii

The phenomenon of global warming is an increase in the earth's temperature due to the greenhouse effect where 50% of the main contributors to the greenhouse effect are carbon dioxide (CO2). Carbon dioxide is one of the ingredients needed for photosynthesis. Photosynthesis is carried out by plants that have chloroplasts. Plants in the waters are Seaweed. Gracilaria changii is a type of red seaweed (Rhodophyceae). The dominant pigment from Gracilaria changii is carotenoids. Carotenoid serves as a light energy absorbent for photosynthesis and serves to protect chlorophyll from light damage. Seeing the important role of carotenoids in Gracilaria changii so that this study aims to determine the effect of increasing temperature and carbon dioxide on carotenoid pigments. Research on the scenario of global warming in this region was first carried out on a laboratory scale, many previous studies were carried out in the cultivation area. This study was conducted for 40 days, seaweed that has been cleaned is put into an aquarium and given an injection of CO2. We were exposed to present-day control seawater (400 ppm pCO2 ) and seawater treated with CO2 to simulate ocean conditions predicted for the next 50–100 years (700 ppm, 1000 ppm, and 1300 ppm) and temperature treatment (30 oC, 32 oC, 34 oC). The research design applied in this study is a Completely Randomized Design consisting of nine treatments with three replications. Data analysis used is Analysis of Variance (ANOVA) continued by Post hoc Test. The results obtained from this study there were significant differences (

Estimating the Population Standard Deviation with Confidence Interval: A Simulation Study under Skewed and Symmetric Conditions

This paper investigates the performance of ten methods for constructing a confidence interval estimator for the population standard deviation by a simulation study. Since a theoretical comparison among the interval estimators is not possible, a simulation study has been conducted to compare the performance of the selected interval estimators. Data were randomly generated from several distributions with a range of sample sizes. Various evaluation criterions are considered for performance comparison. Two health related data have been analyzed to illustrate the application of the proposed confidence intervals. Based on simulation results, some intervals with the best performance have been recommended for practitioners

Moderate hypothermia within 6 h of birth plus inhaled xenon versus moderate hypothermia alone after birth asphyxia (TOBY-Xe): a proof-of-concept, open-label, randomised controlled trial

Background Moderate cooling after birth asphyxia is associated with substantial reductions in death and disability, but additional therapies might provide further benefit. We assessed whether the addition of xenon gas, a promising novel therapy, after the initiation of hypothermia for birth asphyxia would result in further improvement. Methods Total Body hypothermia plus Xenon (TOBY-Xe) was a proof-of-concept, randomised, open-label, parallel-group trial done at four intensive-care neonatal units in the UK. Eligible infants were 36–43 weeks of gestational age, had signs of moderate to severe encephalopathy and moderately or severely abnormal background activity for at least 30 min or seizures as shown by amplitude-integrated EEG (aEEG), and had one of the following: Apgar score of 5 or less 10 min after birth, continued need for resuscitation 10 min after birth, or acidosis within 1 h of birth. Participants were allocated in a 1:1 ratio by use of a secure web-based computer-generated randomisation sequence within 12 h of birth to cooling to a rectal temperature of 33·5°C for 72 h (standard treatment) or to cooling in combination with 30% inhaled xenon for 24 h started immediately after randomisation. The primary outcomes were reduction in lactate to N-acetyl aspartate ratio in the thalamus and in preserved fractional anisotropy in the posterior limb of the internal capsule, measured with magnetic resonance spectroscopy and MRI, respectively, within 15 days of birth. The investigator assessing these outcomes was masked to allocation. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00934700, and with ISRCTN, as ISRCTN08886155. Findings The study was done from Jan 31, 2012, to Sept 30, 2014. We enrolled 92 infants, 46 of whom were randomly assigned to cooling only and 46 to xenon plus cooling. 37 infants in the cooling only group and 41 in the cooling plus xenon group underwent magnetic resonance assessments and were included in the analysis of the primary outcomes. We noted no significant differences in lactate to N-acetyl aspartate ratio in the thalamus (geometric mean ratio 1·09, 95% CI 0·90 to 1·32) or fractional anisotropy (mean difference −0·01, 95% CI −0·03 to 0·02) in the posterior limb of the internal capsule between the two groups. Nine infants died in the cooling group and 11 in the xenon group. Two adverse events were reported in the xenon group: subcutaneous fat necrosis and transient desaturation during the MRI. No serious adverse events were recorded. Interpretation Administration of xenon within the delayed timeframe used in this trial is feasible and apparently safe, but is unlikely to enhance the neuroprotective effect of cooling after birth asphyxia

Selected psychiatric problems among college students in two Arab countries: Comparison with the USA

Background: Psychiatric problems among college students on USA campuses are common. Little is known about similar problems in developing countries, particularly the Arab region. The goal of this study was to assess the frequency of selected psychiatric problems among college students in two Arab countries: Qatar and Lebanon, and to compare them to the USA. Methods: The Healthy Minds Study, an online confidential survey of common psychiatric symptoms designed for college campuses was used. We used the Patient Health Questionnaire-9 (PHQ-9) to screen for major depression, the Generalized Anxiety Disorder-7 (GAD-7) to screen for generalized anxiety and the SCOFF questionnaire to screen for eating disorders. Comparisons were made using ANOVA, Chi-Square tests and logistic regressions. Results: A total of 1841 students participated in the study. The rates of depression (PHQ-9 ? 12), generalized anxiety (GAD-7 ? 10) and eating disorders (SCOFF?3) at the combined Arab universities were 34.6, 36.1 and 20.4% respectively. The corresponding rates in the USA were: 12.8, 15.9 and 6.8% (p < 0.001 for all measures). The impact of psychiatric problems on functioning in general and academic performance in particular was more severe in the Arab countries compared to the USA (p < 0.001). Independent predictors of psychiatric problems in general included location, female gender, financial difficulties and poor grades. Being religious had a protective association with mental health. Conclusion: The rates of depression, anxiety and eating disorders were significantly higher among college students in Qatar and Lebanon compared to the USA. Additional research is needed to determine whether these results reflect methodological limitations or true differences in psychopathology across these populations. If replicated, the results indicate that the psychiatric problems on college campuses in the USA are a microcosm of a global problem that needs global solutions. 2018 The Author(s).This study was made possible by NPRP Grant 5–618–5-087 from the Qatar National Research Fund (a member of Qatar Foundation). The findings achieved herein are solely the responsibility of the authors.Scopu