Anomalous Electron Transport in Field-Effect Transistors with Titanium Ditelluride Semimetal Thin-Film Channels

We report on "graphene-like" mechanical exfoliation of thin films of titanium ditelluride and investigation of their electronic properties. The exfoliated crystalline TiTe2 films were used as the channel layers in the back-gated field-effect transistors fabricated with Ti/Al/Au metal contacts on SiO2/Si substrates. The room-temperature current-voltage characteristics revealed strongly non-linear behavior with signatures of the source-drain threshold voltage similar to those observed in the charge-density-wave devices. The drain-current showed an unusual non-monotonic dependence on the gate bias characterized by the presence of multiple peaks. The obtained results can be potentially used for implementation of the non-Boolean logic gates.Comment: 11 pages, 4 figure

Effects of Serotonin Transporter Gene Variation on Impulsivity Mediated by Default Mode Network: A Family Study of Depression

Serotonergic neurotransmission, potentially through effects on the brain’s default mode network (DMN), may regulate aspects of attention including impulse control. Indeed, genetic variants of the serotonin transporter (5-HTT) have been implicated in impulsivity and related psychopathology. Yet it remains unclear the mechanism by which the 5-HTT genetic variants contribute to individual variability in impulse control. Here, we tested whether DMN connectivity mediates an association between the 5-HTT genetic variants and impulsivity. Participants (N = 92) were from a family cohort study of depression in which we have previously shown a broad distribution of 5-HTT variants. We genotyped for 5-HTTLPR and rs25531 (stratified by transcriptional efficiency: 8 low/low, 53 low/high, and 31 high/high), estimated DMN structural connectivity using diffusion probabilistic tractography, and assessed behavioral measures of impulsivity (from 12 low/low, 48 low/high, and 31 high/high) using the Continuous Performance Task. We found that low transcriptional efficiency genotypes were associated with decreased connection strength between the posterior DMN and the superior frontal gyrus (SFG). Path modeling demonstrated that decreased DMN–SFG connectivity mediated the association between low-efficiency genotypes and increased impulsivity. Taken together, this study suggests a gene-brain-behavior pathway that perhaps underlies the role of the serotonergic neuromodulation in impulse control

GREEN PRODUCTIVITY: AN APPROACH FOR SUSTAINABLE DEVELOPMENT OF AGRO-FORESTRY IN SRI LANKA.

The agricultural and forest resources in Sri Lanka are diminishing while thepopulation is still growing. Hence, designing of resource-efficient agroforestrysystems has considerable potential not only to improve forest andagricultural production but also to enhance and maintain overall productivityof sustainable small farm units. The different types of agro forestry systemsin the country are highly diverse and complex in characters and functions.However, the productivity of agro-forestry system and the role inenvironmental conservation are lower than their potential due to lack ofproper management practices. Green Productivity (GP) approach emphasizesthe sustainable development of agro-forestry systems enhancing productivityand using resources efficiently while protecting the environment.The paper attempts to discuss the concept, methodology, principle stage,implementation strategies and impact assessment of GP approach with theview of sustainable development of agro-forestry systems in Sri Lanka. TheGP concept emphasizes environmentally sound technology transfer to keepagro forestry systems competitive; environmental regulations to extendfarmers responsibility; and cleaner production enhancing productivity andenvironmental performance of the agro-forestry systems. The methodologyof GP would consist of problem-solving steps, selecting tools, techniques andtechnologies useful for solving problems in agro forestry and application ofsocio-economic and environmental principles and values for agro-forestryimprovements. The six principle stages of GP are described in terms ofgetting started to gain base-line information and identify problems in agroforestrysystems: generation and evaluation of GP options to meet theobjectives and targets of the agro-forestry system: implementation of GPoptions involving performance and the targets being achieved: and sustainingGP through corrective options to achieve objectives and targets of thesustainable agro forestry systems

Evaluation of pesticide impact rating index (PIRI) model as a pesticide risk indicator

Systematic methods for assessment of potential risk of pesticides to the environment can be consideredas valuable tools in decision-making and policy formulation. Pesticide Impact Rating Index (PIRI) isa user-friendly simple risk indicator and it can be used to rank pesticides in terms of their mobility. Thepredictions given by using PIRI for the pollution potential of pesticides on shallow ground waterbodies of Kalpitiya area in Sri Lanka was compared with the field experiments. Cultivated areas ofKalpitiya peninsula were selected for field trials.Oxytluorfen for onions, Chlorpyrifos, Diazinon, Dimethoate, Carbofuran, Carbaryl, Mcthornyl,Irnidacloprid, Fenthion and Captan for chili were applied in replicates at recommended applicationrates for particular crops. Each area was irrigated at the rate of 20 mm/day. The soil considered wasthe sandy soil with the organic matter of 1.6±0.2%. Residue levels of applied pesticides were measuredusing Gas Chromatographic and High Performance Liquid Chromatographi methods in irrigation wellsin 100 m diameter area at 3 m depth for 3 months in one week intervals from the time of pesticideapplication. The detected pesticides were confirmed using Gas Chromatographic MassSpectrophotometric method.Out of applied pesticides, Dirnethoate, Carbofuran, and Chlorpyrifos leached 3 m water table in 24±4days, 25±3 days and 3 5±6 days respectively after application of each pesticide. The field monitoringresults were 74% compatible with the predictions from PIRI. This indicates that PIRI can be used asa simple risk indicator model for the prediction of pesticide risk to water bodies.

Screening For Depression In African-american Churches

Introduction: Substantial racial/ethnic disparities exist in the identification and management of major depression. Faith-Based Health Promotion interventions reduce disparities in health screenings for numerous medical conditions. However, the feasibility of systematically screening for depression in faith-based settings has not been investigated. The purpose of this study was to assess the feasibility of using a validated instrument to screen for depression in African-American churches. Methods: Participants were recruited between October and November 2012 at three predominantly African-American churches in New York City. A participatory research approach was used to determine screening days. The Patient Health Questionnaire-9 (PHQ-9) was administered to 122 participants. Positive depression screen was defined as a PHQ-9 score Z10. Descriptive statistics were used to report sample characteristics, prevalence of participants who screened positive, and history of help seeking. Logistic regression analyses were conducted to determine the association of positive depression screen and sociodemographic characteristics. Initial analyses were conducted in 2013, with additional analyses in 2014. Results: The prevalence estimate for positive depression screen was 19.7%. More men (22.5%) screened positive than women (17.7%). Total household income was inversely related to positive depression screen. A similar percentage of respondents had previously sought help from primary care providers as from clergy. Conclusions: It was feasible to screen for depression with the PHQ-9 in African-American churches. The prevalence of positive depression screen was high, especially among black men. Churches may be an important setting in which to identify depressive symptoms in this underserved population

Nanomechanical probing of the layer/substrate interface of an exfoliated InSe sheet on sapphire

Van der Waals (vdW) layered crystals and heterostructures have attracted substantial interest for potential applications in a wide range of emerging technologies. An important, but often overlooked, consideration in the development of implementable devices is phonon transport through the structure interfaces. Here we report on the interface properties of exfoliated InSe on a sapphire substrate. We use a picosecond acoustic technique to probe the phonon resonances in the InSe vdW layered crystal. Analysis of the nanomechanics indicates that the InSe is mechanically decoupled from the substrate and thus presents an elastically imperfect interface. A high degree of phonon isolation at the interface points toward applications in thermoelectric devices, or the inclusion of an acoustic transition layer in device design. These findings demonstrate basic properties of layered structures and so illustrate the usefulness of nanomechanical probing in nanolayer/nanolayer or nanolayer/substrate interface tuning in vdW heterostructures

Treatment Of Maternal Depression In A Medication Clinical Trial And Its Effect On Children

Objective: Observational studies show that when a depressed mother’s symptoms remit, her children’s psychiatric symptoms decrease. Using randomized treatment assignment, the authors sought to determine the differential effects of a depressed mother’s treatment on her child. Method: The study was a randomized double-blind 12-week trial of escitalopram, bupropion, or the combination of the two in depressed mothers (N=76), with independent assessment of their children (N=135; ages 7–17 years). Results: There were no significant treatment differences in mothers’ depressive symptoms or remission. Children’s depressive symptoms and functioning improved significantly among those whose mothers were in the escitalopram group (compared with those whose mothers were in the bupropion and combination treatment groups). Only in the escitalopram group was significant improvement of mother’s depression associated with improvement in the child’s symptoms. Exploratory analyses suggested that this may be due to changes in parental functioning: Mothers in the escitalopram group reported significantly greater improvement, compared with the other groups, in their ability to listen and talk to their children, who as a group reported that their mothers were more caring over the 12 weeks. Maternal baseline negative affectivity appeared to moderate the effect of maternal treatment on children, although the effect was not statistically significant. Children of mothers with low negative affectivity improved in all treatment groups. Children of mothers with high negative affectivity improved significantly only for those whose mothers were in the escitalopram group. Conclusions: The effects of the depressed mother’s improvement on her children may depend on her type of treatment. Depressed mothers with high anxious distress and irritability may require medications that reduce these symptoms in order to show the effect of her remission on her children