2,130 research outputs found
Elevated Depressive Symptoms In A Community Sample Of African-Americans And Whites
This study examined demographic and psychosocial correlates of elevated depressive symptoms among African-Americans and Whites from comparable socioeconomic and neighborhood backgrounds. 851 African-Americans and 597 Whites from adjacent census tracts were interviewed using previously validated indicators of depressive symptoms, social support, religious practices and various demographic characteristics. More Whites than African-Americans reported elevated depressive symptoms and the groups also differed on several demographic variables and psychosocial variables. Employment, marital status and age were salient demographic covariates for African Americans, while income was for Whites. For both groups, social support and church attendance were inversely associated with depressive symptoms. Prayer was positively associated with depressive symptoms. Future research should explore within racial/ethnic group variations in depressive symptoms. Insights also are needed into possible changes over time in the relationship between religious variables and depressive symptoms, and how social support limits depressive symptoms in diverse populations
Very Rapid Onset Cannabis Dependence Risk in Relation to Co-Occurring Use of Other Psychoactive Drugs
Background: Epidemiological estimates for lifetime cumulative incidence indicate that for every 9-11 who start using cannabis, one becomes a case of the cannabis dependence syndrome (CDS) – i.e., roughly 9%-11%. More recent estimates clarify that CDS risk might be much lower among ’cannabis only’ users, due in part to the fact that many ’cannabis only’ users try the drug a few times and never again. We turned to Hill functional analysis in order to study CDS probability soon after 1st cannabis use, estimated across strata defined by the number of recent days of cannabis use, with an acknowledgment that a persistence of cannabis use beyond a few trials (may signify a potentially higher risk subgroup).
Methods: United States National Surveys on Drug Use and Health (NSDUH), 2004-2014, sampled and assessed more than 500,000 participants, yielding a nationally representative probability sample of 13,874 newly incident cannabis users, with CDS assessment no more than 12 months since 1st use. For this analysis, we focused on the subgroup of 4,934 subjects with persistence of cannabis use into the 30 days prior to assessment. For this subgroup, we used Hill functions to estimate variations in CDS probability across strata defined by cannabis-using days during the 30 days prior to assessment, and by history of using other psychoactive drug compounds.
Results: Our preliminary results show that among ’cannabis only’ users (n=1,811) the probability of CDS starts at about 1% for occasional users (95% bootstrap confidence interval, CI: 0, 2), rising to about 9% for daily users (95% CI: 4.5, 23). However, estimated probability of CDS for daily users is greater when cannabis plus ethanol (but no other drugs) is being used (n=1,753): 63% (95% CI: 47, 84); here, use on same day is not required. Our presentation will show additional Hill function estimates for other cannabis and drug combinations (e.g., cannabis and tobacco, cannabis and alcohol and tobacco).
Conclusions: Notwithstanding NSDUH self-report methods and other limitations, the main finding is that probability of observing cannabis dependence is greater when cannabis use co-occurs with other psychoactive drug use. CDS probability is relatively low for ’cannabis only’ users even when ’trial’ users are excluded. These epidemiological estimates are consistent with a re-appraisal of cannabis dependence risk for ’cannabis only’ users
Improving the Health of African Americans in the USA: An Overdue Opportunity for Social Justice
Using a modified social ecological model, we conducted a review of the literature and nationwide statistics on African American health. We discuss the main social determinants of health and main health disparities, risk factors, the leading causes of morbidity and mortality, and access to health services for blacks in the USA. The mechanisms through which social determinants, including racism, exert their deleterious effects on black health are discussed at the macro and individual levels. Incarceration and mental health care issues are highlighted as priorities to be addressed. African Americans remain the least healthy ethnic group in the USA, a somber legacy of years of racial and social injustice and a formidable challenge to equitable health care for all. Systemic causes of suboptimal black health require equally systemic solutions; positive trends in black health indicators seem to be driven by social development programs, economic investment in education, participation of African Americans in policy, and decision-making and expansion of access to health care
A responsabilidade social no Brasil: O caso da cooperativa COCAMAR
Neste trabalho analisamos como a responsabilidade social e ambiental se inserem na estratégia da Cocamar ? Cooperativa Agroindustrial de Maringá. O estudo do caso é apoiado em dados primários e secundários, em particular em entrevistas com os colaboradores da Cocamar diretamente envolvidos nos programas de responsabilidade social e ambiental. Ilustramos as mudanças organizacionais e dos valores culturais da cooperativa que suportam o leque de projetos sociais desenvolvidos junto àcomunidade interna e externa. Concluimos com a análise de como a responsabilidade social corporativa se insere na estratégia das empresas, implicações para a teoria e a prática e sugestão de investigações futuras.Responsabilidade social, responsabilidade ambiental, estratégia empresarial, cooperativas.
Species Distribution During Solid Electrolyte Interphase Formation on Lithium Using MD/DFT-Parameterized Kinetic Monte Carlo Simulations
Lithium metal batteries are one of the promising technologies for future energy storage. One open challenge is the generation of a stable and well performing Solid Electrolyte Interphase (SEI) between lithium metal and electrolyte. Understanding the complex interaction of reactions at the lithium surface and the resulting SEI is crucial for knowledge-driven improvement of the SEI. This study reveals the internal species distribution and geometrical aspects of the native SEI during formation by model-based analysis. To achieve this, a combination of molecular dynamics, density functional theory, and stand-alone 3D-kinetic Monte Carlo simulations is used. The kinetic Monte Carlo model determines the SEI growth features over a long time and length scale so that the SEI can be analyzed quantitatively. The simulation confirms the frequently postulated layered SEI structure arising from the decomposition of an ethylene carbonate/lithium hexafluorophosphate (2 M) electrolyte with lithium metal. These layers are not clearly separated, which is contrary to what is often reported. The gradient distribution of the species within the SEI therefore corresponds to a partly mosaic structured SEI at the borders of the layers. At the lithium surface, an inorganic layer of lithium
fluoride and then lithium carbonate is observed, followed by an organic, more porous SEI layer consisting of lithium ethylene dicarbonate. Simulations further reveal the strong prevalence of corrosion processes of the metal, which provide more than 99% of the lithium for the SEI reaction processes. The salt contributes less than 1% to the SEI formation. Additionally, SEI formation below and above the initial interface was observable. The here presented novel modeling approach allows an unprecedented in-depth analysis of processes during native SEI formation that can be used to improve design for high battery performance and durability
Incoherent electronic band states in Mn substituted BaFeAs
Chemical substitution is commonly used to explore new ground states in
materials, yet the role of disorder is often overlooked. In Mn-substituted
BaFeAs (MnBFA), superconductivity (SC) is absent, despite being
observed for nominal hole-doped phases. Instead, a glassy magnetic phase
emerges, associated with the Mn local spins. In this work, we present a
comprehensive investigation of the electronic structure of MnBFA using
angle-resolved photoemission spectroscopy (ARPES). We find that Mn causes
electron pockets to shrink, disrupting the nesting condition in MnBFA. Notably,
we propose that electronic disorder, along with magnetic scattering, primarily
contributes to suppressing the itinerant magnetic order in MnBFA. This finding
connects the MnBFA electronic band structure properties to the glassy magnetic
behavior observed in these materials and suggests that SC is absent because of
the collective magnetic impurity behavior that scatters the Fe-derived
excitations. Moreover, we suggest that Mn tunes MnBFA to a phase in between the
correlated metal in BaFeAs and the Hund insulator phase in
BaMnAs.Comment: main 7 pages, 3 figures + supp 5 pages, 5 figure
Wnt signaling and Loxl2 promote aggressive osteosarcoma
Osteosarcoma (OS) is the most frequent primary malignant bone tumor in urgent need of better therapies. Using genetically
modified mouse models (GEMMs), we demonstrate that Wnt signaling promotes c-Fos-induced OS formation via the actions of the
collagen-modifying enzyme Loxl2. c-Fos/AP-1 directly regulates the expression of the Wnt ligands Wnt7b and Wnt9a in OS cells
through promoter binding, and Wnt7b and Wnt9a in turn promote Loxl2 expression in murine and human OS cells through the
transcription factors Zeb1 and Zeb2. Concordantly, inhibition of Wnt ligand secretion by inactivating the Wnt-less (Wls) gene in
osteoblasts in c-Fos GEMMs either early or in a therapeutic setting reduces Loxl2 expression and progression of OS. Wls-deficient
osteosarcomas proliferate less, are less mineralized and are enriched in fibroblastic cells surrounded by collagen fibers. Importantly,
Loxl2 inhibition using either the pan-Lox inhibitor BAPN or a specific inducible shRNA reduces OS cell proliferation in vitro and
decreases tumor growth and lung colonization in murine and human orthotopic OS transplantation models. Finally, OS
development is delayed in c-Fos GEMMs treated with BAPN or with specific Loxl2 blocking antibodies. Congruently, a strong
correlation between c-FOS, LOXL2 and WNT7B/WNT9A expression is observed in human OS samples, and c-FOS/LOXL2 coexpression correlates with OS aggressiveness and decreased patient survival. Therefore, therapeutic targeting of Wnt and/or
Loxl2 should be considered to potentiate the inadequate current treatments for pediatric, recurrent, and metastatic OS
High pressure density and speed of sound of hydrofluoroether fluid 1,1,1,2,2,3,4,5,5,5-decafluoro-3-methoxy-4-(trifluoromethyl)-pentane (HFE-7300)
High pressure density measurements were carried out for the hydrofluoroether fluid HFE-7300. A total of 159 points have been measured in the pressure range from 0.1 to 140 MPa and along seven isotherms within the temperature interval (293.15–393.15) K. To perform these measurements, an Anton Paar vibrating tube densitometer was used. The experimental high pressure density data were correlated to a Tait-like equation and compared with the available literature. By deriving the Tait-like equation, the isothermal compressibility and isothermal compressibility were also determined in the same P and T ranges. The speed of sound measurements were performed along six isotherms from 293.15 to 333.15 K at 0.1 MPa. The isentropic compressibilities were also calculated from speed of sound and density data by means of the Laplace equatio
Can One Trust Quantum Simulators?
Various fundamental phenomena of strongly-correlated quantum systems such as
high- superconductivity, the fractional quantum-Hall effect, and quark
confinement are still awaiting a universally accepted explanation. The main
obstacle is the computational complexity of solving even the most simplified
theoretical models that are designed to capture the relevant quantum
correlations of the many-body system of interest. In his seminal 1982 paper
[Int. J. Theor. Phys. 21, 467], Richard Feynman suggested that such models
might be solved by "simulation" with a new type of computer whose constituent
parts are effectively governed by a desired quantum many-body dynamics.
Measurements on this engineered machine, now known as a "quantum simulator,"
would reveal some unknown or difficult to compute properties of a model of
interest. We argue that a useful quantum simulator must satisfy four
conditions: relevance, controllability, reliability, and efficiency. We review
the current state of the art of digital and analog quantum simulators. Whereas
so far the majority of the focus, both theoretically and experimentally, has
been on controllability of relevant models, we emphasize here the need for a
careful analysis of reliability and efficiency in the presence of
imperfections. We discuss how disorder and noise can impact these conditions,
and illustrate our concerns with novel numerical simulations of a paradigmatic
example: a disordered quantum spin chain governed by the Ising model in a
transverse magnetic field. We find that disorder can decrease the reliability
of an analog quantum simulator of this model, although large errors in local
observables are introduced only for strong levels of disorder. We conclude that
the answer to the question "Can we trust quantum simulators?" is... to some
extent.Comment: 20 pages. Minor changes with respect to version 2 (some additional
explanations, added references...
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