Degeneration and Reorganization of Vestibular Epithelia after Local Aminoglycoside Application in the Mammalian Inner Ear

The development of degeneration of vestibular end organs and their possible reorganization have been observed over a 2 year period after local application of sisomicin in the inner ear using scanning electron microscopy (SEM). Degeneration of stereocilia took place as early as 5 days after the treatment in the utricule, the saccule and the cristae. At 10 days, almost the entire surface of these sensory epithelia presented a smooth aspect without specific structure. However, after 15 days, an epithelial reorganization developed with clear limits between cells. At 25 days, systematic kinociliary structures were observed at the apical surface of the cells. Five months after the treatment, the new kinocilium was still present and sometimes stereociliary-like structures appeared in the three types of vestibular organs. Two years after treatment, the kinocilium persisted and the embryonic-like ciliary tufts had disappeared. These SEM observations suggest that in mammals some vestibular epithelial regeneration is possible but stops at a stage which could correspond to an early developmental level

High impact weather and cyclones simultaneity in Catalonia

International audienceThe Western Mediterranean in general and Catalonia in particular are usually affected by high impact weather (HIW) events, mainly heavy rain (HR) and strong wind (SW). The improvement in the understanding and the accurate forecast of such events are major concerns for the meteorologists of the region. In the present study, HR and SW events in Catalonia are cross-referenced with an objective cyclone database for a 9-year period (from June 1995 to May 2004). Results show that in most of the HR events a cyclone is located close to Catalonia, in such a way that the feeding of a moist flow to the affected region was favoured. These cyclones can be either shallow and weak or deep and intense. A simultaneous cyclone also appears to be connected with many SW events. However, other SW events seem to be related to meso-scale circulations and, as a result, not always well captured in the cyclone database. Finally, coincident HR and SW events are analysed. In almost all of such events a deep cyclone is located in the vicinity of Catalonia

Comprehensive transcriptomic analysis of cell lines as models of primary tumors across 22 tumor types.

Cancer cell lines are a cornerstone of cancer research but previous studies have shown that not all cell lines are equal in their ability to model primary tumors. Here we present a comprehensive pan-cancer analysis utilizing transcriptomic profiles from The Cancer Genome Atlas and the Cancer Cell Line Encyclopedia to evaluate cell lines as models of primary tumors across 22 tumor types. We perform correlation analysis and gene set enrichment analysis to understand the differences between cell lines and primary tumors. Additionally, we classify cell lines into tumor subtypes in 9 tumor types. We present our pancreatic cancer results as a case study and find that the commonly used cell line MIA PaCa-2 is transcriptionally unrepresentative of primary pancreatic adenocarcinomas. Lastly, we propose a new cell line panel, the TCGA-110-CL, for pan-cancer studies. This study provides a resource to help researchers select more representative cell line models

Development of a single crystal sample holder for interfacing ultrahigh vacuum and electrochemical experimentation

Electrocatalyst surfaces prepared under ultrahigh vacuum (UHV) conditions can create model surfaces to better connect theoretical calculations with experimental studies. The development of a single crystal sample holder and inert electrochemical cells prepared with modularity and chemical stability in mind would allow for expensive single crystals to be reused indefinitely in both UHV and electrochemical settings. This sample holder shows reproducible surface preparations for single crystal samples and consistent electrochemical experiments without the introduction of impurities into the surface. The presented setup has been used as a critical piece for the characterization of Cu(111) surfaces under CO2 electrochemical reduction reaction conditions as a test case

Drift induced perpendicular transport of solar energetic particles

Drifts are known to play a role in galactic cosmic ray transport within the heliosphere and are a standard component of cosmic ray propagation models. However, the current paradigm of solar energetic particle (SEP) propagation holds the effects of drifts to be negligible, and they are not accounted for in most current SEP modeling efforts. We present full-orbit test particle simulations of SEP propagation in a Parker spiral interplanetary magnetic field (IMF), which demonstrate that high-energy particle drifts cause significant asymmetric propagation perpendicular to the IMF. Thus in many cases the assumption of field-aligned propagation of SEPs may not be valid. We show that SEP drifts have dependencies on energy, heliographic latitude, and charge-to-mass ratio that are capable of transporting energetic particles perpendicular to the field over significant distances within interplanetary space, e.g., protons of initial energy 100 MeV propagate distances across the field on the order of 1 AU, over timescales typical of a gradual SEP event. Our results demonstrate the need for current models of SEP events to include the effects of particle drift. We show that the drift is considerably stronger for heavy ion SEPs due to their larger mass-to-charge ratio. This paradigm shift has important consequences for the modeling of SEP events and is crucial to the understanding and interpretation of in situ observations. © 2013. The American Astronomical Society. All rights reserved.

A Framework for Quality K-12 Engineering Education: Research and Development

Recent U.S. national documents have laid the foundation for highlighting the connection between science, technology, engineering and mathematics at the K-12 level. However, there is not a clear definition or a well-established tradition of what constitutes a quality engineering education at the K-12 level. The purpose of the current work has been the development of a framework for describing what constitutes a quality K-12 engineering education. The framework presented in this paper is the result of a research project focused on understanding and identifying the ways in which teachers and schools implement engineering and engineering design in their classrooms. The development of the key indicators that are included in the framework were determined based on an extensive review of the literature, established criteria for undergraduate and professional organizations, document content analysis of state academic content standards in science, mathematics, and technology, and in consultation with experts in the fields of engineering and engineering education. The framework is designed to be used as a tool for evaluating the degree to which academic standards, curricula, and teaching practices address the important components of a quality K-12 engineering education. Additionally, this framework can be used to inform the development and structure of future K-12 engineering and STEM education standards and initiatives

Analysis of synoptic patterns in relationship with severe rainfall events in the Ebre Observatory (Catalonia)

The study has obtained a classification of the synoptic patterns associated with a selection of extreme rain episodes registered in the Ebre Observatory between 1905 and 2003, showing a return period of not less than 10 years for any duration from 5 min to 24 h. These episodes had been previously classified in four rainfall intensity groups attending to their meteorological time scale. The synoptic patterns related to every group have been obtained applying a multivariable analysis to three atmospheric levels: sea-level pressure, temperature, and geopotential at 500 hPa. Usually, the synoptic patterns associated with intense rain in southern Catalonia are featured by low-pressure systems advecting warm and wet air from the Mediterranean Sea at the low levels of the troposphere. The configuration in the middle levels of the troposphere is dominated by negative anomalies of geopotential, indicating the presence of a low or a cold front, and temperature anomalies, promoting the destabilization of the atmosphere. These configurations promote the occurrence of severe convective events due to the difference of temperature between the low and medium levels of troposphere and the contribution of humidity in the lowest levels of the atmosphere.Peer ReviewedPostprint (author's final draft

Negative regulation of syntaxin4/SNAP-23/VAMP2-mediated membrane fusion by Munc18c <i>In Vitro</i>

Background: Translocation of the facilitative glucose transporter GLUT4 from an intracellular store to the plasma membrane is responsible for the increased rate of glucose transport into fat and muscle cells in response to insulin. This represents a specialised form of regulated membrane trafficking. Intracellular membrane traffic is subject to multiple levels of regulation by conserved families of proteins in all eukaryotic cells. Notably, all intracellular fusion events require SNARE proteins and Sec1p/Munc18 family members. Fusion of GLUT4-containing vesicles with the plasma membrane of insulin-sensitive cells involves the SM protein Munc18c, and is regulated by the formation of syntaxin 4/SNAP23/VAMP2 SNARE complexes. Methodology/Principal Findings Here we have used biochemical approaches to characterise the interaction(s) of Munc18c with its cognate SNARE proteins and to examine the role of Munc18c in regulating liposome fusion catalysed by syntaxin 4/SNAP23/VAMP2 SNARE complex formation. We demonstrate that Munc18c makes contacts with both t- and v-SNARE proteins of this complex, and directly inhibits bilayer fusion mediated by the syntaxin 4/SNAP23/VAMP2 SNARE complex. Conclusion/Significance Our reductionist approach has enabled us to ascertain a direct inhibitory role for Munc18c in regulating membrane fusion mediated by syntaxin 4/SNAP23/VAMP2 SNARE complex formation. It is important to note that two different SM proteins have recently been shown to stimulate liposome fusion mediated by their cognate SNARE complexes. Given the structural similarities between SM proteins, it seems unlikely that different members of this family perform opposing regulatory functions. Hence, our findings indicate that Munc18c requires a further level of regulation in order to stimulate SNARE-mediated membrane fusion

Insuficiencia renal aguda (IRA) en unidades de cuidados intensivos

La Injuria Renal Aguda es reconocida por su impacto en la evolución de los pacientes admitidos en Unidades de cuidados Intensivos. La amplia variedad de definiciones utilizadas en los diversos estudios es responsable de las diferencias en los reportes de incidencia y de Mortalidad asociada.Facultad de Ciencias Médica