1,220 research outputs found
Intersection of ecosystem and biodiversity concerns in the management of rangelands
Maintenance of ecological functions and disturbance regimes within ecosystems is as important as preserving species populations or their genetic structure, biotic communities, and landscapes. There is considerable dispute as to how species diversity influences productivity and stability of various ecosystem structural and dynamic attributes. Some view each and every species as making an incremental contribution to these features. Others assume that some redundancy exists. Addition or loss of species can be anecdotally shown to influence ecosystems in proportion to the role such organisms. Subtle but essential interactions are easy to overlook, however. We should try to keep all the parts until more definitive research is available on this topic. Sustainable development will require balancing resource use with maintenance of our natural legacies. Ecosystem perspectives must contribute to decisions on where the balance exists
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Diffusion Tensor Imaging, Structural Connectivity, and Schizophrenia
A fundamental tenet of the “disconnectivity” theories of schizophrenia is that the disorder is ultimately caused by abnormal communication between spatially disparate brain structures. Given that the white matter fasciculi represent the primary infrastructure for long distance communication in the brain, abnormalities in these fiber bundles have been implicated in the etiology of schizophrenia. Diffusion tensor imaging (DTI) is a magnetic resonance imaging (MRI) technique that enables the visualization of white matter macrostructure in vivo, and which has provided unprecedented insight into the existence and nature of white matter abnormalities in schizophrenia. The paper begins with an overview of DTI and more commonly used diffusion metrics and moves on to a brief review of the schizophrenia literature. The functional implications of white matter abnormalities are considered, particularly with respect to myelin's role in modulating the transmission velocity of neural discharges. The paper concludes with a speculative hypothesis about the relationship between gray and white matter abnormalities associated with schizophrenia
Letter Referred to the Adjunct General of Augusta, ME. Requesting Information about an unknown agency from, E. L. Whitford
https://digitalmaine.com/arc_me_militia/1007/thumbnail.jp
Cumulative sociodemographic disadvantage partially mediates associations between childhood trauma and schizotypy
Objectives: Risk for psychosis in the general population is characterized by a set of multidimensional traits that are referred to as schizotypy. Higher levels of schizotypy are associated with socioeconomic disadvantage and childhood trauma, just as these risk factors are associated with schizophrenia and bipolar disorder. Here, we set out to investigate whether cumulative sociodemographic disadvantage mediates associations between childhood trauma and schizotypy in adulthood. Methods: A sociodemographic cumulative risk (SDCR) score was derived from six risk indices spanning employment, education, income, socioeconomic status, marital, and living circumstances for 197 participants that included both healthy (n = 57) and clinical samples with schizophrenia or schizoaffective disorder (n = 65) or bipolar disorder (n = 75). A series of multiple linear regressions was used to examine the direct and indirect associations among childhood trauma (measured with the Childhood Trauma Questionnaire), the SDCR index, and levels of schizotypy (measured with the Schizotypal Personality Questionnaire). Results: Schizotypy was independently associated with trauma and the SDCR index. In addition, the SDCR index partially mediated associations between trauma and schizotypy. Conclusions: These findings in a mixed sample of healthy and clinical participants represent the full spectrum of schizotypy across health and illness and suggest that effects of childhood trauma on schizotypal personality organization may operate via cumulative socioeconomic disadvantage in adulthood. Practitioner points: The strong associations between trauma and schizotypy suggest that systematic health screening of children exposed to early life trauma may assist to identify those at risk of developing psychosis. Clinicians should pay attention to various indicators of sociodemographic disadvantage in patients prone to psychosis, in addition to any exposure to trauma during childhood
The Ratio of Total to Selective Extinction Toward Baade's Window
We measure the ratio of total to selective extinction, R_{VI}=A_V/E(V-I),
toward Baade's Window by comparing the VIK colors of 132 Baade's Window G and K
giants from Tiede, Frogel, & Terndrup with the solar-neighborhood (V-I),(V-K)
relation from Bessell & Brett. We find R_{VI}=2.283 +/- 0.016, and show that
our measurement has no significant dependence on stellar type from G0 to K4.
Adjusting the Paczynski et al. determination of the centroid of the dereddened
Baade's Window clump for this revised value of , we find I_{0,RC}=14.43
and (V-I)_{0,RC}=1.058. This implies a distance to the Baade's Window clump of
d_{BW} = 8.63 +/- 0.16 kpc, where the error bar takes account of statistical
but not systematic uncertainties.Comment: 8 pages, 1 figure, submitted to Ap
A refined hydrogen bond potential for flexible protein models
One of the major disadvantages of coarse-grained hydrogen bond potentials, for their use in protein folding simulations, is the appearance of abnormal structures when these potentials are used in flexible chain models, and no other geometrical restrictions or energetic contributions are defined into the system.We have efficiently overcome this problem, for chains of adequate size in a relevant temperature range, with a refined coarse-grained hydrogen bond potential. With it, we have been able to obtain nativelike alpha-helices and beta-sheets in peptidic systems, and successfully reproduced the competition between the populations of these secondary structure elements by the effect of temperature and concentration changes. In this manuscript we detail the design of the interaction potential and thoroughly examine its applicability in energetic and structural terms, considering factors such as chain length, concentration, and temperature
Peer support for patients with type 2 diabetes: cluster randomised controlled trial
Objective To test the effectiveness of peer support for patients with type 2 diabetes
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