Erosive processes due to physical-biological interactions based in a cellular automata model

The Bahía Blanca Estuary (38° 50' S, 62° 30' W) presents salt marshes where interactions between the local main plant and the dominant crab generate some very characteristics salt pans. These pans alter the normal water circulation and condition its trajectory generating an erosive process. The removed sediment is then exported to the main estuary through the creeks that evolve from those biological-physical interactions. To study it, a conceptual model is proposed, based on the laws deduced from observation of these phenomena in the field, and then verified with measurable data within macroscale time units. The objective of this article is to model how the interaction between the crab C. granulata and the plant S. perennis modifies the landscape of the salt marsh and influences the loss of sediment with a Cellular Automata Model. Originally developed to study the effect of the interaction plant - crab in the formation of tidal creeks, the model copies the basic laws that dominate the problem based on purely biological factors. Finally, the volume of sediment that is removed and how it varies in time are evaluated. The model results a very good tool to integrate a large quantity of data collected recently and to be able to extract conclusions on processes that have a very slow dynamics. Additionally, it could reproduce faithfully the salt marsh landscape product of the plants - crab interaction

Trends of and factors associated with live-birth and abortion rates among HIV-positive and HIV-negative women

Little is known about fertility choices and pregnancy outcome rates among HIV-infected women in the current combination ART era

Beyond belief: Strategic taboos and organizational identity in strategic agenda setting

A comprehensive strategic agenda matters for fundamental strategic change. Our study seeks to explore and theorize how organizational identity beliefs influence the judgment of strategic actors when setting an organization’s strategic agenda. We offer the notion of “strategic taboo” as those strategic options initially disqualified and deemed inconsistent with the organizational identity beliefs of strategic actors. Our study is concerned with how strategic actors confront strategic taboos in the process of setting an organization’s strategic agenda. Based on a revelatory inductive case study, we find that strategic actors engage in assessing the concordance of the strategic taboos with organizational identity beliefs and, more specifically, that they focus on key identity elements (philosophy; priorities; practices) when doing so. We develop a typology of three reinterpretation practices that are each concerned with a key identity element. While contextualizing assesses the potential concordance of a strategic taboo with an organization’s overall philosophy and purpose, instrumentalizing assesses such concordance with respect to what actors deem an organization’s priorities to be. Finally, normalizing explores concordance with respect to compatibility and fit with the organization’s practices. We suggest that assessing concordance of a strategic taboo with identity elements consists in reinterpreting collective identity beliefs in ways that make them consistent with what organizational actors deem the right course of action. This article discusses the implications for theory and research on strategic agenda setting, strategic change, a practice-based perspective on strategy, and on organizational identity. © The Author(s) 2014

Advances in thermal hydraulic and neutronic simulation for reactor analysis and safety

This paper describes several large-scale computational models developed at Argonne National Laboratory for the simulation and analysis of thermal-hydraulic and neutronic events in nuclear reactors and nuclear power plants. The impact of advanced parallel computing technologies on these computational models is emphasized

Juxta-articular myxoma of the knee in a 5-year-old boy: a case report and review of the literature (2009: 12b)

Juxta-articular myxoma (JAM) is a relatively rare variant of myxoma that occurs in the vicinity of large joints. It is composed of fibroblast-like cells that produce an excessive amount of glycosaminoglycans rich in hyaluronic acid. The peak incidence is between the 3rd and 5th decades of life. In this report we describe an extremely rare case of JAM in the knee of a 5-year-old child. The clinical presentation, radiological features and histopathologic findings are described, and the relevant literature is reviewed

Cervical Screening within HIV Care: Findings from an HIV-Positive Cohort in Ukraine

HIV-positive women have an increased risk of invasive cervical cancer but cytologic screening is effective in reducing incidence. Little is known about cervical screening coverage or the prevalence of abnormal cytology among HIV-positive women in Ukraine, which has the most severe HIV epidemic in Europe

On Radio Detection of Ultra-High Energy Neutrinos in Antarctic Ice

Interactions of ultrahigh energy neutrinos of cosmological origin in large volumes of dense, radio-transparent media can be detected via coherent Cherenkov emission from accompanying electromagnetic showers. Antarctic ice meets the requirements for an efficient detection medium for a radio frequency neutrino telescope. We carefully estimate the sensitivity of realistic antennas embedded deep in the ice to 100 MHz - 1 GHz signals generated by predicted neutrino fluxes from active galactic nuclei. Our main conclusion is that a {\it single radio receiver} can probe a $\sim 1$ ${\rm km}^3$ volume for events with primary energy near 2 PeV and that the total number of events registered would be roughly 200 to 400 ${\rm year}^{-1}$ in our most conservative estimate. An array of such receivers would increase sensitivity dramatically. A radio neutrino telescope could directly observe and test our understanding of the most powerful particle accelerators in the universe, simultaneously testing the standard theory of particle physics at unprecedented energies.Comment: 45 pages, 21 figures, uuencoded, gzipped, submitted to Phys. Rev. D, also available at http://poincare.math.ukans.edu/~frichter/radio.html (Shading in Figure 21 fixed

Generalized cerebral atrophy seen on MRI in a naturally exposed animal model for creutzfeldt-jakob disease

<p>Abstract</p> <p>Background</p> <p>Magnetic resonance imaging has been used in the diagnosis of human prion diseases such as sCJD and vCJD, but patients are scanned only when clinical signs appear, often at the late stage of disease. This study attempts to answer the questions "Could MRI detect prion diseases before clinical symptoms appear?, and if so, with what confidence?"</p> <p>Methods</p> <p>Scrapie, the prion disease of sheep, was chosen for the study because sheep can fit into a human sized MRI scanner (and there were no large animal MRI scanners at the time of this study), and because the USDA had, at the time of the study, a sizeable sample of scrapie exposed sheep, which we were able to use for this purpose. 111 genetically susceptible sheep that were naturally exposed to scrapie were used in this study.</p> <p>Results</p> <p>Our MRI findings revealed no clear, consistent hyperintense or hypointense signal changes in the brain on either clinically affected or asymptomatic positive animals on any sequence. However, in all 37 PrP^Scpositive sheep (28 asymptomatic and 9 symptomatic), there was a greater ventricle to cerebrum area ratio on MRI compared to 74 PrP^Scnegative sheep from the scrapie exposed flock and 6 control sheep from certified scrapie free flocks as defined by immunohistochemistry (IHC).</p> <p>Conclusions</p> <p>Our findings indicate that MRI imaging can detect diffuse cerebral atrophy in asymptomatic and symptomatic sheep infected with scrapie. Nine of these 37 positive sheep, including 2 one-year old animals, were PrP^Scpositive only in lymph tissues but PrP^Scnegative in the brain. This suggests either 1) that the cerebral atrophy/neuronal loss is not directly related to the accumulation of PrP^Scwithin the brain or 2) that the amount of PrP^Scin the brain is below the detectable limits of the utilized immunohistochemistry assay. The significance of these findings remains to be confirmed in human subjects with CJD.</p

Psychosocial, socio-cultural, and environmental influences on mental health help-seeking among African-American men

http://dx.doi.org/10.1016/j.jomh.2012.03.00

Antiretroviral Therapy Initiation Before, During, or After Pregnancy in HIV-1-Infected Women: Maternal Virologic, Immunologic, and Clinical Response

Pregnancy has been associated with a decreased risk of HIV disease progression in the highly active antiretroviral therapy (HAART) era. The effect of timing of HAART initiation relative to pregnancy on maternal virologic, immunologic and clinical outcomes has not been assessed.We conducted a retrospective cohort study from 1997–2005 among 112 pregnant HIV-infected women who started HAART before (N = 12), during (N = 70) or after pregnancy (N = 30).0.01). There were no statistical differences in rates of HIV disease progression between groups.HAART initiation during pregnancy was associated with better immunologic and virologic responses than initiation after pregnancy