284 research outputs found

    Reimagining the journey to recovery: The COVID-19 pandemic and global mental health

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    In this editorial, guest editors Vikram Patel, Daisy Fancourt, Lola Kola, and Toshi Furukawa discuss the contents of the special issue on the pandemic and global mental health, highlighting key themes and providing important context

    Magnetron sputtering of thin nitride films

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    The objective in this investigation was to design and commission a magnetron sputter deposition system and investigate the properties of hard coatings for mechanical and biomedical applications. The deposition of titanium (Ti) and titanium nitride (TiN) was undertaken as part of the commissioning tests and further work was conducted on the effect of the deposition parameters on the properties of TiN, specifically for biocompatible applications. A thorough understanding of the deposition process, film microstructure and sample preparation was achieved, and several measurement techniques utilised in the characterisation of the films. The nature of TiN as a biocompatible coating, and the effect of the deposition parameters on the hermeticity of the film was investigated by using electrographic printing as a technique for observing the pinhole defects on the film surface. It was found however, that the fluid used in the printing method caused corrosion of the substrate material and hence may have caused increased pinhole size. The second topic of investigation was the novel film caibon nitride (CNX), a new and promising coating in the area of tribological coatings. Investigations were undertaken to deposit the theoretical coating P-C3N4, a material harder than diamond. The understoichiometric CNX form was deposited successfully, and the films characterised optically, structurally, compositionally and topographically. An investigation of the effect of the deposition parameters - magnetron current, substrate bias, system pressure and nitrogen partial pressure on film properties revealed that the films were amorphous in nature with nitrogen incorporation of upto 18.5 % atomic. The films showed evidence of carbon bonding ,as detected by infra-red spectroscopy. It was also found that increased graphitic bonding occurred during nitrogen partial pressure increase but that a reduction in the graphitic nature was seen for films deposited at high magnetron current, low system pressure and high negative substrate bias, all of which affect the ion bombardment of the film. The film surface was smooth and featureless and brown in colour. Tribological evaluation was undertaken of caibon nitride films deposited onto tool steel and surgical steel. It was found that the films possessed low coefficients of friction and good wear resistance, but these properties were dependent on the substrate material due to the thinness of the films. An investigation of adhesion promoted by interiayer growth was also conducted, and it was found for carbon nitride coatings on steel substrates, that Ti and TiN interlayers promoted adhesion, but there was no advantage in a TiC interiayer. Carbon nitride has good tribological properties, and could possibly be used in both mechanical and biomedical applications

    Comparing the personal oral hygiene practices among Government and Private school children of Mahabubnagar, Telangana state - A cross sectional study

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    Introduction: Oral health is fundamental to general health and well-being. A healthy mouth enables an individual to talk, eat, and socialize without experiencing active disease, discomfort, or embarrassment. Objectives: To assess the knowledge and oral hygiene practices of school children from both Government and Private schools in Mahabubnagar district. Materials and Methods: A total of 150 children aged 11–15 years were randomly selected from six Private and six Government schools. A questionnaire related to their personal and oral hygiene practices was distributed to the school children. Results: The results of this study showed thatmost respondents had a good knowledge of basic hygiene measures and positive attitude towards oral hygiene. The students of both schools exhibited poor oral hygiene practices but were significantly reported more in the Government school than in the Private schools (p<0.005). Majority of the respondents (91.3%) used a commercial toothbrush and toothpaste and half of them (50%) reported brushing twice a day. Two-third of the respondents (75%), had never visited a dental clinic. Conclusion: The results of the present study showed that the knowledge and oral hygiene practices of Government school children were less satisfactory in someaspects when compared to private school children.&nbsp

    Optimum Design of Thin Wideband Multilayer Electromagnetic Shield Using Evolutionary Algorithms

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    This paper describes the method of optimum design of multilayer perforated electromagnetic shield using Evolutionary algorithms, namely Particle Swarm Optimization Algorithm (PSO) and Genetic Algorithm (GA). Different parameters which are inherently conflicting in nature corresponds to the multilayer structure of the electromagnetic shields have been considered. The goal is to minimize the overall mass of the shield with respect to its shielding effectiveness and cost. Three different models are considered and synthesized using evolutionary algorithms. Numerical optimal results for each model using different algorithms are presented and compared with each other to establish the effectiveness of the proposed method of designing

    Synthesis of Steered Flat-top Beam Pattern Using Evolutionary Algorithm

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    In this paper a pattern synthesis method based on Evolutionary Algorithm is presented. A Flat-top beam pattern has been generated from a concentric ring array of isotropic elements by finding out the optimum set of elements amplitudes and phases using Differential Evolution algorithm. The said pattern is generated in three predefined azimuth planes instate of a single phi plane and also verified for a range of azimuth plane for the same optimum excitations. The main beam is steered to an elevation angle of 30 degree with lower peak SLL and ripple. Dynamic range ratio (DRR) is also being improved by eliminating the weakly excited array elements, which simplify the design complexity of feed networks

    Kinstate intervention in ethnic conflicts : Albania and Turkey compared

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    Albania and Turkey did not act in overtly irredentist ways towards their ethnic brethren in neighboring states after the end of communism. Why, nonetheless, did Albania facilitate the increase of ethnic conflict in Kosovo and Macedonia, while Turkey did not, with respect to the Turks of Bulgaria? I argue that kin-states undergoing transition are more prone to intervene in external conflicts than states that are not, regardless of the salience of minority demands in the host-state. The transition weakens the institutions of the kin-state. Experiencing limited institutional constraints, self-seeking state officials create alliances with secessionist and autonomist movements across borders alongside their own ideological, clan-based and particularistic interests. Such alliances are often utilized to advance radical domestic agendas. Unlike in Albania's transition environment, in Turkey there were no emerging elites that could potentially form alliances and use external movements to legitimize their own domestic existence or claims

    The Orexigenic Effect of Ghrelin Is Mediated through Central Activation of the Endogenous Cannabinoid System

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    INTRODUCTION Ghrelin and cannabinoids stimulate appetite, this effect possibly being mediated by the activation of hypothalamic AMP-activated protein kinase (AMPK), a key enzyme in appetite and metabolism regulation. The cannabinoid receptor type 1 (CB1) antagonist rimonabant can block the orexigenic effect of ghrelin. In this study, we have elucidated the mechanism of the putative ghrelin-cannabinoid interaction. METHODS The effects of ghrelin and CB1 antagonist rimonabant in wild-type mice, and the effect of ghrelin in CB1-knockout animals, were studied on food intake, hypothalamic AMPK activity and endogenous cannabinoid content. In patch-clamp electrophysiology experiments the effect of ghrelin was assessed on the synaptic inputs in parvocellular neurons of the hypothalamic paraventricular nucleus, with or without the pre-administration of a CB1 antagonist or of cannabinoid synthesis inhibitors. RESULTS AND CONCLUSIONS Ghrelin did not induce an orexigenic effect in CB1-knockout mice. Correspondingly, both the genetic lack of CB1 and the pharmacological blockade of CB1 inhibited the effect of ghrelin on AMPK activity. Ghrelin increased the endocannabinoid content of the hypothalamus in wild-type mice and this effect was abolished by rimonabant pre-treatment, while no effect was observed in CB1-KO animals. Electrophysiology studies showed that ghrelin can inhibit the excitatory inputs on the parvocellular neurons of the paraventricular nucleus, and that this effect is abolished by administration of a CB1 antagonist or an inhibitor of the DAG lipase, the enzyme responsible for 2-AG synthesis. The effect is also lost in the presence of BAPTA, an intracellular calcium chelator, which inhibits endocannabinoid synthesis in the recorded parvocellular neuron and therefore blocks the retrograde signaling exerted by endocannabinoids. In summary, an intact cannabinoid signaling pathway is necessary for the stimulatory effects of ghrelin on AMPK activity and food intake, and for the inhibitory effect of ghrelin on paraventricular neurons

    Ghrelin Modulates the fMRI BOLD Response of Homeostatic and Hedonic Brain Centers Regulating Energy Balance in the Rat

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    The orexigenic gut-brain peptide, ghrelin and its G-protein coupled receptor, the growth hormone secretagogue receptor 1a (GHS-R1A) are pivotal regulators of hypothalamic feeding centers and reward processing neuronal circuits of the brain. These systems operate in a cooperative manner and receive a wide array of neuronal hormone/transmitter messages and metabolic signals. Functional magnetic resonance imaging was employed in the current study to map BOLD responses to ghrelin in different brain regions with special reference on homeostatic and hedonic regulatory centers of energy balance. Experimental groups involved male, ovariectomized female and ovariectomized estradiol-replaced rats. Putative modulation of ghrelin signaling by endocannabinoids was also studied. Ghrelin-evoked effects were calculated as mean of the BOLD responses 30 minutes after administration. In the male rat, ghrelin evoked a slowly decreasing BOLD response in all studied regions of interest (ROI) within the limbic system. This effect was antagonized by pretreatment with GHS-R1A antagonist JMV2959. The comparison of ghrelin effects in the presence or absence of JMV2959 in individual ROIs revealed significant changes in the prefrontal cortex, nucleus accumbens of the telencephalon, and also within hypothalamic centers like the lateral hypothalamus, ventromedial nucleus, paraventricular nucleus and suprachiasmatic nucleus. In the female rat, the ghrelin effects were almost identical to those observed in males. Ovariectomy and chronic estradiol replacement had no effect on the BOLD response. Inhibition of the endocannabinoid signaling by rimonabant significantly attenuated the response of the nucleus accumbens and septum. In summary, ghrelin can modulate hypothalamic and mesolimbic structures controlling energy balance in both sexes. The endocannabinoid signaling system contributes to the manifestation of ghrelin’s BOLD effect in a region specific manner. In females, the estradiol milieu does not influence the BOLD response to ghrelin

    Targeting pathogen metabolism without collateral damage to the host

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    The development of drugs that can inactivate disease-causing cells (e.g. cancer cells or parasites) without causing collateral damage to healthy or to host cells is complicated by the fact that many proteins are very similar between organisms. Nevertheless, due to subtle, quantitative differences between the biochemical reaction networks of target cell and host, a drug can limit the flux of the same essential process in one organism more than in another. We identified precise criteria for this â €network-based' drug selectivity, which can serve as an alternative or additive to structural differences. We combined computational and experimental approaches to compare energy metabolism in the causative agent of sleeping sickness, Trypanosoma brucei, with that of human erythrocytes, and identified glucose transport and glyceraldehyde-3-phosphate dehydrogenase as the most selective antiparasitic targets. Computational predictions were validated experimentally in a novel parasite-erythrocytes co-culture system. Glucose-transport inhibitors killed trypanosomes without killing erythrocytes, neurons or liver cells

    A pilot randomized controlled trial of a stepped care intervention package for depression in primary care in Nigeria

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    Background Depression is common in primary care and is often unrecognized and untreated. Studies are needed to demonstrate the feasibility of implementing evidence-based depression care provided by primary health care workers (PHCWs) in sub-Saharan Africa. We carried out a pilot two-parallel arm cluster randomized controlled trial of a package of care for depression in primary care. Methods Six primary health care centers (PHCC) in two Local Government Areas of Oyo State, South West Nigeria were randomized into 3 intervention and 3 control clinics. Three PHCWs were selected for training from each of the participating clinics. The PHCWs from the intervention clinics were trained to deliver a manualized multicomponent stepped care intervention package for depression consisting of psychoeducation, activity scheduling, problem solving treatment and medication for severe depression. Providers from the control clinics delivered care as usual, enhanced by a refresher training on depression diagnosis and management. Outcome measures Patient’s Health Questionnaire (PHQ-9), WHO quality of Life instrument (WHOQOL-Bref) and the WHO disability assessment schedule (WHODAS) were administered in the participants’ home at baseline, 3 and 6 months. Results About 98% of the consecutive attendees to the clinics agreed to have the screening interview. Of those screened, 284 (22.7%) were positive (PHQ-9 score ≥ 8) and 234 gave consent for inclusion in the study: 165 from intervention and 69 from control clinics. The rates of eligible and consenting participants were similar in the control and intervention arms. In all 85.9% (92.8% in intervention and 83% in control) of the participants were successfully administered outcome assessments at 6 months. The PHCWs had little difficulty in delivering the intervention package. At 6 months follow up, depression symptoms had improved in 73.0% from the intervention arm compared to 51.6% control. Compared to the mean scores at baseline, there was improvement in the mean scores on all outcome measures in both arms at six months. Conclusion The results provide support for the feasibility of conducting a fully-powered randomized study in this setting and suggest that the instruments used may have the potential to detect differences between the arms
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