Substrate-induced band gap opening in epitaxial graphene

Graphene has shown great application potentials as the host material for next generation electronic devices. However, despite its intriguing properties, one of the biggest hurdles for graphene to be useful as an electronic material is its lacking of an energy gap in the electronic spectra. This, for example, prevents the use of graphene in making transistors. Although several proposals have been made to open a gap in graphene's electronic spectra, they all require complex engineering of the graphene layer. Here we show that when graphene is epitaxially grown on the SiC substrate, a gap of ~ 0.26 is produced. This gap decreases as the sample thickness increases and eventually approaches zero when the number of layers exceeds four. We propose that the origin of this gap is the breaking of sublattice symmetry owing to the graphene-substrate interaction. We believe our results highlight a promising direction for band gap engineering of graphene.Comment: 10 pages, 4 figures; updated reference

Testing the cognitive-behavioural maintenance models across DSM-5 bulimic-type eating disorder diagnostic groups: A multi-centre study

The original cognitive-behavioural (CB) model of bulimia nervosa, which provided the basis for the widely used CB therapy, proposed that specific dysfunctional cognitions and behaviours maintain the disorder. However, amongst treatment completers, only 40–50 % have a full and lasting response. The enhanced CB model (CB-E), upon which the enhanced version of the CB treatment was based, extended the original approach by including four additional maintenance factors. This study evaluated and compared both CB models in a large clinical treatment seeking sample (N = 679), applying both DSM-IV and DSM-5 criteria for bulimic-type eating disorders. Application of the DSM-5 criteria reduced the number of cases of DSM-IV bulimic-type eating disorders not otherwise specified to 29.6 %. Structural equation modelling analysis indicated that (a) although both models provided a good fit to the data, the CB-E model accounted for a greater proportion of variance in eating-disordered behaviours than the original one, (b) interpersonal problems, clinical perfectionism and low self-esteem were indirectly associated with dietary restraint through over-evaluation of shape and weight, (c) interpersonal problems and mood intolerance were directly linked to binge eating, whereas restraint only indirectly affected binge eating through mood intolerance, suggesting that factors other than restraint may play a more critical role in the maintenance of binge eating. In terms of strength of the associations, differences across DSM-5 bulimic-type eating disorder diagnostic groups were not observed. The results are discussed with reference to theory and research, including neurobiological findings and recent hypotheses

Adding 5-hydroxytryptamine receptor type 3 antagonists may reduce drug-induced nausea in poor insight obsessive-compulsive patients taking off-label doses of selective serotonin reuptake inhibitors: a 52-week follow-up case report

Poor-insight obsessive-compulsive disorder (PI-OCD) is a severe form of OCD where the 'typically obsessive' features of intrusive, 'egodystonic' feelings and thoughts are absent. PI-OCD is difficult to treat, often requiring very high doses of serotonergic drugs as well as antipsychotic augmentation. When this occurs, unpleasant side effects as nausea are common, eventually further reducing compliance to medication and increasing the need for pharmacological alternatives. We present the case of a PI-OCD patient who developed severe nausea after response to off-label doses of the selective serotonin reuptake inhibitor (SSRI), fluoxetine. Drug choices are discussed, providing pharmacodynamic rationales and hypotheses along with reports of rating scale scores, administered within a follow-up period of 52 weeks. A slight reduction of fluoxetine dose, augmentation with mirtazapine and a switch from amisulpride to olanzapine led to resolution of nausea while preserving the anti-OCD therapeutic effect. Mirtazapine and olanzapine have already been suggested for OCD treatment, although a lack of evidence exists about their role in the course of PI-OCD. Both mirtazapine and olanzapine also act as 5-hydroxytryptamine receptor type 3 (5-HT3) blockers, making them preferred choices especially in cases of drug-induced nausea

β-Adrenoceptor blockade modulates fusiform gyrus activity to black versus white faces.

INTRODUCTION: The beta-adrenoceptor antagonist propranolol is known to reduce peripheral and central activity of noradrenaline. A recent study found that intervention with propranolol diminished negative implicit racial bias. MATERIALS AND METHOD: The current study used functional magnetic resonance imaging (fMRI) in order to determine the neural correlates of this effect. Healthy volunteers (N = 40) of white ethnic origin received a single oral dose (40 mg) of propranolol, in a randomised, double-blind, parallel group, placebo-controlled design, before viewing unfamiliar faces of same and other race. RESULTS AND DISCUSSION: We found significantly reduced activity in the fusiform gyrus and thalamus following propranolol to out-group faces only. Additionally, propranolol lowered the implicit attitude score, without affecting explicit prejudice measure. CONCLUSION: These findings suggest that noradrenaline pathways might modulate racial bias by acting on the processing of categorisation in the fusiform gyrus

Water quality and planktonic microbial assemblages of isolated wetlands in an agricultural landscape

Author Posting. © The Author(s), 2011. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Wetlands 31 (2011): 885-894, doi:10.1007/s13157-011-0203-6.Wetlands provide ecosystem services including flood protection, water quality enhancement, food chain support, carbon sequestration, and support regional biodiversity. Wetlands occur in human-altered landscapes, and the ongoing ability of these wetlands to provide ecosystem services is lacking. Additionally, the apparent lack of connection of some wetlands, termed geographically isolated, to permanent waters has resulted in little regulatory recognition. We examined the influence of intensive agriculture on water quality and planktonic microbial assemblages of intermittently inundated wetlands. We sampled 10 reference and 10 agriculturally altered wetlands in the Gulf Coastal Plain of Georgia. Water quality measures included pH, alkalinity, dissolved organic carbon, nutrients (nitrate, ammonium, and phosphate), and filterable solids (dry mass and ash-free dry mass). We measured abundance and relative size distribution of the planktonic microbial assemblage (< 45 μm) using flow cytometry. Water quality in agricultural wetlands was characterized by elevated nutrients, pH, and suspended solids. Autotrophic microbial cells were largely absent from both wetland types. Heterotrophic microbial abundance was influenced by nutrients and suspended matter concentration. Agriculture caused changes in microbial assemblages forming the base of wetland food webs. Yet, these wetlands potentially support important ecological services in a highly altered landscape.Funding was provided by the Joseph W. Jones Ecological Research Center.2012-07-2

Comportamentos agressivos em crianças e adolescentes com risco para esquizofrenia: diferenças entre gêneros

OBJECTIVE: This study aimed to investigate whether differences in aggression-related behavioral problems occur between boys and girls at high risk for schizophrenia living in the city of São Paulo, Brazil. METHOD: Using the Child Behavior Checklist, we compared the prevalence of behavioral problems between genders for the offspring (6-18 years) of mothers with diagnosis of schizophrenia and a comparison group of children born to women with no severe mental disorders recruited at the gynecology outpatient clinic of the same hospital. The Structured Clinical Interview for DSM-IV Axis I Disorders, Patient Edition was applied for the evaluation of diagnostic status of mothers. RESULTS: Male children of women with schizophrenia had a lower prevalence of aggressive behavior compared to females (4% vs. 36%; p = 0.005), whereas no gender differences regarding aggression were detected in the comparison group (24% vs. 32%; p = 0.53). Logistic regression analyses showed that male gender and being a child of women with schizophrenia interacted so as to favor lower prevalence of aggressive behavior (p = 0.03). CONCLUSION: These findings reinforce the notion that behavioral gender differences related to schizophrenia are already detectable in childhood.OBJETIVO: Investigar diferenças da ocorrência de comportamentos agressivos entre crianças e adolescentes do sexo masculino e feminino com risco genético para desenvolver esquizofrenia. MÉTODO: A prevalência de comportamentos agressivos foi medida utilizando o inventário de comportamentos para crianças e adolescentes, Child Behavior Checklist, e comparada entre os gêneros para o grupo de crianças filhas de mulheres com esquizofrenia e para um grupo de crianças filhas de mulheres atendidas no serviço de ginecologia do mesmo hospital. A entrevista clínica estruturada para DSM-IV (The Structured Clinical Interview for DSM-IV Axis I Disorders Patient Edition) foi utilizada para confirmar o diagnóstico materno. RESULTADOS: Os filhos de mulheres com esquizofrenia do sexo masculino apresentaram prevalência menor de comportamentos agressivos quando comparados às meninas (4% x 36%; p = 0,005), o que não ocorreu para o grupo comparativo (24% x 32%; p = 0,53). A análise de regressão logística mostrou que pertencer ao sexo masculino e ser filho de mulher com esquizofrenia interagiram de forma a favorecer menor prevalência de comportamentos agressivos (p = 0,03). CONCLUSÃO: Esses achados corroboram para a noção que as diferenças comportamentais entre os gêneros na esquizofrenia podem ser detectadas precocemente durante a infância

From benzos to berries: treatment offered at an Aboriginal youth solvent abuse treatment centre relays the importance of culture.

First Nations and Inuit youth who abuse solvents are one of the most highly stigmatized substance-abusing groups in Canada. Drawing on a residential treatment response that is grounded in a culture-based model of resiliency, this article discusses the cultural implications for psychiatry's individualized approach to treating mental disorders. A systematic review of articles published in The Canadian Journal of Psychiatry during the past decade, augmented with a review of Canadian and international literature, revealed a gap in understanding and practice between Western psychiatric disorder-based and Aboriginal culture-based approaches to treatment and healing from substance abuse and mental disorders. Differing conceptualizations of mental health and substance abuse are discussed from Western psychiatric and Aboriginal worldviews, with a focus on connection to self, community, and political context. Applying an Aboriginal method of knowledge translation-storytelling-experiences from front-line workers in a youth solvent abuse treatment centre relay the difficulties with applying Western responses to Aboriginal healing. This lends to a discussion of how psychiatry can capitalize on the growing debate regarding the role of culture in the treatment of Aboriginal youth who abuse solvents. There is significant need for culturally competent psychiatric research specific to diagnosing and treating First Nations and Inuit youth who abuse substances, including solvents. Such understanding for front-line psychiatrists is necessary to improve practice. A health promotion perspective may be a valuable beginning point for attaining this understanding, as it situates psychiatry's approach to treating mental disorders within the etiology for Aboriginal Peoples

An approach to measure compliance to clinical guidelines in psychiatric care

<p>Abstract</p> <p>Background</p> <p>The aim of this study was to measure six months compliance to Swedish clinical guidelines in psychiatric care after an active supported implementation process, using structured measures derived from the guidelines.</p> <p>Methods</p> <p>In this observational study four psychiatric clinics each participated in active implementation of the clinical guidelines for the assessment and treatment of depression and guidelines for assessment and treatment of patients with suicidal behaviours developed by The Stockholm Medical Advisory Board for Psychiatry. The implementation programme included seminars, local implementation teams, regular feedback and academic visits. Additionally two clinics only received the guidelines and served as controls. Compliance to guidelines was measured using indicators, which operationalised requirements of preferred clinical practice. 725 patient records were included, 365 before the implementation and 360 six months after.</p> <p>Results</p> <p>Analyses of indicators registered showed that the actively implementing clinics significantly improved their compliance to the guidelines. The total score differed significantly between implementation clinics and control clinics for management of depression (mean scores 9.5 (1.3) versus 5.0 (1.5), p < 0.001) as well as for the management of suicide (mean scores 8.1 (2.3) versus 4.5 (1.9), p < 0.001). No changes were found in the control clinics and only one of the OR was significant.</p> <p>Conclusion</p> <p>Compliance to clinical guidelines measured by process indicators of required clinical practice was enhanced by an active implementation.</p