120 research outputs found
A new method for nocturnal aerosol measurements with a lunar photometer prototype
This paper presents the preliminary results of nocturnal Aerosol Optical Depth (τa) and Angström Exponent (α) obtained from a new lunar photometer prototype, trade name Cimel CE-318U. Due to the variation of the moon's illumination inherent to the lunar cycle, the typical Langley-plot Method used in solar photometry to calibrate these instruments cannot be applied. In this paper, we propose three different methods to carry out the lunar-photometer calibration. In order to validate the results, we have selected three events which encompass seven nights and ten days under different atmospheric conditions, including several saharan dust intrusions episodes. Method#1 is introduced in this work as a modification of the usual Langley Method.The Aeronet sunphotometer at Izana has been calibrated within ˜ AERONET-EUROPE TNA supported by the European Community – Research Infrastructure Action under the FP7 “Capacities” specific programme for Integrating Activities, ACTRIS Grant Agreement no. 262254
Lack of evidence for participation of TMEM150C in sensory mechanotransduction
The membrane protein TMEM150C has been proposed to form a mechanosensitive ion channel that is required for normal proprioceptor function. Here, we examined whether expression of TMEM150C in neuroblastoma cells lacking Piezo1 is associated with the appearance of mechanosensitive currents. Using three different modes of mechanical stimuli, indentation, membrane stretch, and substrate deflection, we could not evoke mechanosensitive currents in cells expressing TMEM150C. We next asked if TMEM150C is necessary for the normal mechanosensitivity of cutaneous sensory neurons. We used an available mouse model in which the Tmem150c locus was disrupted through the insertion of a LacZ cassette with a splice acceptor that should lead to transcript truncation. Analysis of these mice indicated that ablation of the Tmem150c gene was not complete in sensory neurons of the dorsal root ganglia (DRG). Using a CRISPR/Cas9 strategy, we made a second mouse model in which a large part of the Tmem150c gene was deleted and established that these Tmem150c(-/-) mice completely lack TMEM150C protein in the DRGs. We used an ex vivo skin nerve preparation to characterize the mechanosenstivity of mechanoreceptors and nociceptors in the glabrous skin of the Tmem150c(-/-) mice. We found no quantitative alterations in the physiological properties of any type of cutaneous sensory fiber in Tmem150c(-/-) mice. Since it has been claimed that TMEM150C is required for normal proprioceptor function, we made a quantitative analysis of locomotion in Tmem150c(-/-) mice. Here again, we found no indication that there was altered gait in Tmem150c(-/-) mice compared to wild-type controls. In summary, we conclude that existing mouse models that have been used to investigate TMEM150C function in vivo are problematic. Furthermore, we could find no evidence that TMEM150C forms a mechanosensitive channel or that it is necessary for the normal mechanosensitivity of cutaneous sensory neurons
Brain tissue recovery in obstructive congenital hydrocephalus after intraventricular transplantation of mesenchymal stem cells
Introduction: Bone marrow-derived mesenchymal stem cells (BM-MSC) are a potential therapeutic tool due to their ability for migrating and producing neuroprotector factors when transplanted. The aim of this study was to evaluate the short-time effects of a BM-MSC experimental therapy in the hyh mouse model with severe obstructive hydrocephalus.
Methods: BM-MSC were characterized in vitro and then injected into the ventricles of hyh mice. Wild-type and saline-injected hyh mice were used as controls. Samples were studied by analyzing and comparing mRNA, protein and metabolites level expression in control and damaged tissue.
Results: Undifferentiated BM-MSC were found to: i) spread into the periventricular astrocyte reaction region after four days post-injection, and, ii) be producing neuroprotector factors (GDNF and VEGF). Astrocytes located in periventricular edematous region increased their aquaporin-4 expression, as well as Slit2 expression (neuroprotective and anti-inflammatory molecule). There was also a significant reduction of osmolytes such as taurine and neuroexcytotoxic glutamate. Halved apoptotic cell death was detected in the periventricular walls.
Conclusions: BM-MSC lead to recovery of the severe neurodegenerative conditions associated to congenital hydrocephalus mediated by reactive astrocytes.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech.
Supported by Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech, and PI15/0619 (ISCIII/FEDER)
The MACC-II 2007–2008 reanalysis: atmospheric dust evaluation and characterization over northern Africa and the Middle East
In the present work, atmospheric mineral dust from a MACC-II short reanalysis run for 2 years (2007–2008) has been evaluated over northern Africa and the Middle East using satellite aerosol products (from MISR, MODIS and OMI satellite sensors), ground-based AERONET data, in situ PM10 concentrations from AMMA, and extinction vertical profiles from two ground-based lidars and CALIOP satellite-based lidar. The MACC-II aerosol optical depth (AOD) spatial and temporal (seasonal and interannual) variability shows good agreement with those provided by satellite sensors. The capability of the model to reproduce the AOD, Ångström exponent (AE) and dust optical depth (DOD) from daily to seasonal time-scale is quantified over 26 AERONET stations located in eight geographically distinct regions by using statistical parameters. Overall DOD seasonal variation is fairly well simulated by MACC-II in all regions, although the correlation is significantly higher in dust transport regions than in dust source regions. The ability of MACC-II in reproducing dust vertical profiles has been assessed by comparing seasonal averaged extinction vertical profiles simulated by MACC-II under dust conditions with corresponding extinction profiles obtained with lidar instruments at M'Bour and Santa Cruz de Tenerife, and with CALIOP.This work has been supported by EU-project Monitoring Atmospheric Composition and Climate (MACC-II) under the European Union Seventh Framework Programme, grant agreement number 283576. J. M. Baldasano and S. Basart acknowledge the Severo Ochoa (SEV-2011-00067) program of the Spanish Government and the mobility program from the Catalan Government (BE-DGR 2012)
Apoptosis, cambio estructural y generación reactiva de especies reactivas de oxígeno en neutrófilos humanos expuestos a olanzapine, una droga antipsicótica atípica
Los efectos de olanzapine (olz) sobre la viabilidad y el funcionamiento de células humanas polimorfonucleares (pmn, por sus siglas en inglés) claramente son opuestos a los señalados para la clozapine (clz). En efecto, después de 4-24 h de tratamiento con 20-50 μM olz, se observó una inhibición significativa del estallido respiratorio en pmn activados con zimosan o con forbol acetato miristato, mientras que la inhibición provocada por el formil-metionil-leucil-fenilalanina fue sólo inhibida a 50 μM de olz. En las mismas condiciones, la apoptosis espontánea se aceleró con 20-50 μM olz, mientras que la adición exógena de H2O2 dio lugar a la apoptosis de pmn en dosis dependiente inhibida por olz en el rango entero de concentraciones. Sin embargo, cuando se generó H2O2 intracelular por tratamiento con pma, la apoptosis inducida se disminuyó solamente con 2 μM olz. Las exploraciones de los espectros de absorbancia revelaron que olz puede reaccionar con cantidades equimolares de H2O2 o de HOCL. Estos resultados sugieren que olz inhibe ambos tipos de apoptosis de pmn (la inducida por especies reactivas oxigenadas y por estallido respiratorio debido a atrapadores extracelulares de estas especies reactivas oxigenadas)
Surgical multicenter collaborative studies: ¿What happen in Latin America?
Antecedentes: GlobalSurg es un grupo internacional de investigadores que tiene como propósito la conducción y la diseminación de robustos estudios colaborativos, internacionales y multicéntricos. Objetivo: Exponer las estrategias necesarias y las barreras encontradas en la conducción de estudios multicéntricos masivos en cirugía. Método: Durante el segundo semestre del año 2020 se llevó a cabo el estudio Surg-Week Prospective International Cohort Study, hasta la fecha el estudio internacional más grande en el campo de la cirugía, con 141,582 pacientes incluidos. Un total de 4975 miniequipos, de uno a cinco integrantes, recopilaron datos de 116 países de todos los continentes. Resultados: La creación de un sitio web oficial del estudio, reportes con información relevante vía e-mail o grupos vía WhatsApp, conformación de un comité de diseminación del protocolo, dictado de webinars sobre publicaciones recientes del equipo, designación de líderes nacionales e internacionales, y la divulgación por medio de sociedades, fueron las estrategias utilizadas para el desarrollo de la investigación. Sin embargo, las barreras detectadas para llevar a cabo el estudio multicéntrico fueron variadas. Conclusiones: Los trabajos colaborativos permiten establecer redes entre diferentes profesionales con el fin de mejorar la calidad de la gestión, las políticas sanitarias y la atención a los pacientes en tiempos de constante cambio.Background: GlobalSurg is an international group of researchers whose purpose is to conduct and disseminate robust collaborative, international and multicenter studies. Objective: To expose the necessary strategies and the barriers crossed in conducting massive multicenter studies in surgery. Method: During the second semester of 2020, the study Surg-Week Prospective International Cohort Study was carried out. Surg-Week has been the largest international study in the field of surgery to date, with 141,582 patients included. A total of 4975 mini-teams, of between 1 and 5 members, collected data from 116 countries on all continents. Results: The creation of an official website for the study, reports with relevant information via email or groups via WhatsApp, formation of a Dissemination Committee of the protocol, delivery of webinars on recent team publications, appointment of leaders at the national and international level, and outreach through partnerships, were the strategies used for the development of the research. However, the barriers turned out to involve different aspects. Conclusions: Collaborative work allows establishing networks between different professionals with the goal of improving the quality of management, health policies and care of our patients in a timely manner of constant change
Switch of noninvasive ventilation (NIV) to continuous positive airway pressure (CPAP) in patients with obesity hypoventilation syndrome: a pilot study
International audienceObesity is a major worldwide public health issue. The main respiratory complication stemming from obesity is obesity hypoventilation syndrome (OHS). Most of the OHS patients diagnosed during an exacerbation are treated with non invasive ventilation (NIV). Up to date, no prospective study has demonstrated in real life conditions the feasibility of a systematic protocoled switch of NIV to continuous positive airway pressure (CPAP), once stability is achieved
Predictive modeling of suitable habitats for threatened marine invertebrates and implications for conservation assessment in Brazil
“Tourism, water, and gender”—An international review of an unexplored nexus
This international literature review of the tourism–water nexus identifies a gender gap. Tourism development can affect water supply both quantitatively and qualitatively. Many regions will face considerable problems of water availability and quality, affecting their tourism sector and increasing competition with local residents, and other industries especially agriculture. This international review of literature explores the tourism–water nexus, comparing and contrasting literature published in English, Chinese, and Spanish. Securing access to safe water for continued tourism development is a common theme and the vast majority of work has focused on hotels including water pricing, water-saving practices and innovative management methods. In all continents, struggles are apparent, and the unsustainability of tourism is having impacts on water quantity and quality. This article identifies significant gaps in the literature including climate change, the energy-water nexus, and the links with the Sustainable Development Goals. Furthermore, studies from a gendered perspective are minimal and the potential for areas of further gendered studies within the tourism–water nexus are highlighted including intersectionality, water insecurity and sanitation, tourism and gender based violence, and additional unpaid care work
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