Phelps Scholars Program

PSP offers first year students a vivid personal and cultural experience steeped in a living and learning community. Their holistic journey reflects innovation as it includes a team-taught First Year Seminar, community placements, bi-monthly meetings and group travel that explores our global society

DECAIMIENTO DE LA ECUACIÓN DE ONDA CON DISIPACIÓN

In this work, we consider the problem of existence of global solutions for a scalar wave equation with dissipation. We study also, the asymptotic behaviour of the solutions. In this part of the paper; we present an alternative method - inspired in nonlinear techniques. In order lo attack this problem, specifically, we used the Conrad - Rao method [l]

The Glial Cell of Human Cutaneous Sensory Corpuscles: Origin, Characterization, and Putative Roles

Sensory corpuscles of human skin are structures located at the peripheral end of the mechanoreceptive neurons and function as low-threshold mechanoreceptors (LTMRs). In its structure, in addition to the axon, there are glial cells, not myelinating, that are organized in different ways according to the morphotype of sensitive corpuscle, forming the so-called laminar cells of Meissner’s corpuscles, the laminar cells of the inner core of Pacinian corpuscles, or cells of the inner core in Ruffini’s corpuscles. Classically the glial cells of sensory corpuscles have been considered support cells and passive in the process of mechanotransduction. However, the presence of ion channels and synapses-like systems between them and the axon suggests that corpuscular glial cells are actively involved in the transformation of mechanical into electrical impulses. This chapter is an update on the origin, development, cytoarchitecture, and protein profile of glial cells of sensitive corpuscles especially those of human glabrous skin

The Cutaneous Biopsy for the Diagnosis of Peripheral Neuropathies: Meissner’s Corpuscles and Merkel’s Cells

Cutaneous biopsy is a complementary method, alternative to peripheral nerve biopsy, for the analysis of nerve involvement in peripheral neuropathies, systemic diseases, and several pathologies of the central nervous system. Most of these neuropathological studies were focused on the intraepithelial nerve fibers (thin-myelinated Aδ fibers and unmyelinated C fibers), and few studies investigated the variations in dermal innervation, that is, large myelinated fibers, Merkel’s cell-neurite complexes, and Meissner’s corpuscles. Here, we updated and summarized the current data about the quantitative and qualitative changes that undergo MCs and MkCs in peripheral neuropathies. Moreover, we provide a comprehensive rationale to include MCs in the study of cutaneous biopsies when analyzing the peripheral neuropathies and aim to provide a protocol to study them

Molecular epidemiology, phylogeny, and phylodynamics of CRF63_02A1, a recently originated HIV-1 circulating recombinant form spreading in Siberia

The HIV-1 epidemic in Russia is dominated by the former Soviet Union subtype A (A(FSU)) variant, but other genetic forms are circulating in the country. One is the recently described CRF63_02A1, derived from recombination between a CRF02_AG variant circulating in Central Asia and A(FSU), which has spread in the Novosibirsk region, Siberia. Here we phylogenetically analyze pol and env segments from 24 HIV-1 samples from the Novosibirsk region collected in 2013, with characterization of three new near full-length genome CRF63_02A1 sequences, and estimate the time of the most recent common ancestor (tMRCA) and the demographic growth of CRF63_02A1 using a Bayesian method. The analyses revealed that CRF63_02A1 is highly predominant in the Novosibirsk region (81.2% in pol sequences) and is transmitted both among injecting drug users and by heterosexual contact. Similarity searches with database sequences combined with phylogenetic analyses show that CRF63_02A1 is circulating in East Kazakhstan and the Eastern area of Russia bordering China. The analyses of near full-length genome sequences show that its mosaic structure is more complex than reported, with 18 breakpoints. The tMRCA of CRF63_02A1 was estimated around 2006, with exponential growth in 2008-2009 and subsequent stabilization. These results provide new insights into the molecular epidemiology, phylogeny, and phylodynamics of CRF63_02A1.We thank the personnel at the Genomic Unit of Instituto de Salud Carlos III, Majadahonda, Madrid, Spain, for technical assistance in sequencing, and Bonnie Mathieson, from the Office of AIDS Research, National Institutes of Health, Bethesda, Maryland for her support of this study. This work was funded by Office of AIDS Research, National Institutes of Health, through the training program “Molecular Epidemiology of HIV-1 in Eastern Europe and Its Significance for Vaccine Development.”S

Policy Recommendations for Meeting the Grand Challenge to Achieve Equal Opportunity and Justice

This brief was created forSocial Innovation for America’s Renewal, a policy conference organized by the Center for Social Development in collaboration with the American Academy of Social Work & Social Welfare, which is leading theGrand Challenges for Social Work initiative to champion social progress. The conference site includes links to speeches, presentations, and a full list of the policy briefs

"Acute kidney injury in critically ill patients with COVID-19 : The AKICOV multicenter study in Catalonia"

This study describes the incidence, evolution and prognosis of acute kidney injury (AKI) in critical COVID-19 during the first pandemic wave. We performed a prospective, observational, multicenter study of confirmed COVID-19 patients admitted to 19 intensive care units (ICUs) in Catalonia (Spain). Data regarding demographics, comorbidities, drug and medical treatment, physiological and laboratory results, AKI development, need for renal replacement therapy (RRT) and clinical outcomes were collected. Descriptive statistics and logistic regression analysis for AKI development and mortality were used. A total of 1,642 patients were enrolled (mean age 63 (15.95) years, 67.5% male). Mechanical ventilation (MV) was required for 80.8% and 64.4% of these patients, who were in prone position, while 67.7% received vasopressors. AKI at ICU admission was 28.4% and increased to 40.1% during ICU stay. A total of 172 (10.9%) patients required RRT, which represents 27.8% of the patients who developed AKI. AKI was more frequent in severe acute respiratory distress syndrome (ARDS) ARDS patients (68% vs 53.6%, p<0.001) and in MV patients (91.9% vs 77.7%, p<0.001), who required the prone position more frequently (74.8 vs 61%, p<0.001) and developed more infections. ICU and hospital mortality were increased in AKI patients (48.2% vs 17.7% and 51.1% vs 19%, p <0.001) respectively). AKI was an independent factor associated with mortality (IC 1.587-3.190). Mortality was higher in AKI patients who required RRT (55.8% vs 48.2%, p <0.04). Conclusions There is a high incidence of AKI in critically ill patients with COVID-19 disease and it is associated with higher mortality, increased organ failure, nosocomial infections and prolonged ICU stay

Microbiology and Nitrogen Cycle in the Benthic Sediments of a Glacial Oligotrophic Deep Andean Lake as Analog of Ancient Martian Lake-Beds

Potential benthic habitats of early Mars lakes, probably oligotrophic, could range from hydrothermal to cold sediments. Dynamic processes in the water column (such as turbidity or UV penetration) as well as in the benthic bed (temperature gradients, turbation, or sedimentation rate) contribute to supply nutrients to a potential microbial ecosystem. High altitude, oligotrophic, and deep Andean lakes with active deglaciation processes and recent or past volcanic activity are natural models to assess the feasibility of life in other planetary lake/ocean environments and to develop technology for their exploration. We sampled the benthic sediments (down to 269 m depth) of the oligotrophic lake Laguna Negra (Central Andes, Chile) to investigate its ecosystem through geochemical, biomarker profiling, and molecular ecology studies. The chemistry of the benthic water was similar to the rest of the water column, except for variable amounts of ammonium (up to 2.8 ppm) and nitrate (up to 0.13 ppm). A life detector chip with a 300-antibody microarray revealed the presence of biomass in the form of exopolysaccharides and other microbial markers associated to several phylogenetic groups and potential microaerobic and anaerobic metabolisms such as nitrate reduction. DNA analyses showed that 27% of the Archaea sequences corresponded to a group of ammonia-oxidizing archaea (AOA) similar (97%) to Nitrosopumilus spp. and Nitrosoarchaeum spp. (Thaumarchaeota), and 4% of Bacteria sequences to nitrite-oxidizing bacteria from the Nitrospira genus, suggesting a coupling between ammonia and nitrite oxidation. Mesocosm experiments with the specific AOA inhibitor 2-Phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide (PTIO) demonstrated an AOA-associated ammonia oxidation activity with the simultaneous accumulation of nitrate and sulfate. The results showed a rich benthic microbial community dominated by microaerobic and anaerobic metabolisms thriving under aphotic, low temperature (4°C), and relatively high pressure, that might be a suitable terrestrial analog of other planetary settings