126 research outputs found
Introducción a la taxonomía : manual de ejercitaciones
Fil: Fernández, Marta Susana. Cátedra de Introducción a la Taxonomía. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Brusa, Francisco. Cátedra de Introducción a la Taxonomía. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Damborenea, María Cristina. Cátedra de Introducción a la Taxonomía. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Dellapé, Pablo Matias. Cátedra de Introducción a la Taxonomía. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Gallardo, Fabiana Edith. Cátedra de Introducción a la Taxonomía. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; Argentin
Investigaciones e investigadores de la UAM
Continuamos en este número de la revista con la sección: Investigaciones en la Universidad Autónoma de Madrid, con la que se pretende dar a conocer investigaciones relacionadas con diversas disciplinas científicas que se han desarrollado o se están llevando a cabo en la UAM, con el fin de describir de una forma simple y didáctica tales trabajos, y con ello los contenidos de diversas ramas del conocimiento, y cumplir así con la finalidad inherente a esta revista de divulgar la ciencia así como de contribuir al surgimiento de posibles ideas o iniciativas para posteriores investigaciones por parte de los jóvenes científicos, o de estudiantes universitarios de grado o posgrado que están en disposición y voluntad de llegar a serlo. Se recogen a continuación algunos relatos de investigaciones realizadas por varios profesores de la UAM, los cuales se recogieron en una publicación conmemorativa del cumplimiento de los cuarenta años por parte de esta universidad y relativos a las siguientes disciplinas: Biomedicina, Historia Contemporánea, Química y alimentación, Matemáticas y Bioquímic
Instruments for assessing the risk of falls in acute hospitalized patients: a systematic review and meta-analysis
Background
Falls are a serious problem for hospitalized patients, reducing the duration and quality of life. It is estimated that over 84% of all adverse events in hospitalized patients are related to falls. Some fall risk assessment tools have been developed and tested in environments other than those for which they were developed with serious validity discrepancies. The aim of this review is to determine the accuracy of instruments for detecting fall risk and predicting falls in acute hospitalized patients.
Methods
Systematic review and meta-analysis. Main databases, related websites and grey literature were searched. Two blinded reviewers evaluated title and abstracts of the selected articles and, if they met inclusion criteria, methodological quality was assessed in a new blinded process. Meta-analyses of diagnostic ORs (DOR) and likelihood (LH) coefficients were performed with the random effects method. Forest plots were calculated for sensitivity and specificity, DOR and LH. Additionally, summary ROC (SROC) curves were calculated for every analysis.
Results
Fourteen studies were selected for the review. The meta-analysis was performed with the Morse (MFS), STRATIFY and Hendrich II Fall Risk Model scales. The STRATIFY tool provided greater diagnostic validity, with a DOR value of 7.64 (4.86 - 12.00). A meta-regression was performed to assess the effect of average patient age over 65 years and the performance or otherwise of risk reassessments during the patient’s stay. The reassessment showed a significant reduction in the DOR on the MFS (rDOR 0.75, 95% CI: 0.64 - 0.89, p = 0.017).
Conclusions
The STRATIFY scale was found to be the best tool for assessing the risk of falls by hospitalized acutely-ill adults. However, the behaviour of these instruments varies considerably depending on the population and the environment, and so their operation should be tested prior to implementation. Further studies are needed to investigate the effect of the reassessment of these instruments with respect to hospitalized adult patients, and to consider the real compliance by healthcare personnel with procedures related to patient safety, and in particular concerning the prevention of falls
TRPC Channels: Dysregulation and Ca2+ Mishandling in Ischemic Heart Disease
Transient receptor potential canonical (TRPC) channels are ubiquitously expressed in excitable and non-excitable cardiac cells where they sense and respond to a wide variety of physical and chemical stimuli. As other TRP channels, TRPC channels may form homo or heterotetramericion channels, and they can associate with other membrane receptors and ion channels to regulate intracellular calcium concentration. Dysfunctions of TRPC channels are involved in many types of cardiovascular diseases. Significant increase in the expression of different TRPC isoforms was observed in different animal models of heart infarcts and in vitro experimental models of ischemia and reperfusion. TRPC channel-mediated increase of the intracellular Ca2+ concentration seems to be required for the activation of the signaling pathway that plays minor roles in the healthy heart, but they are more relevant for cardiac responses to ischemia, such as the activation of different factors of transcription and cardiac hypertrophy, fibrosis, and angiogenesis. In this review, we highlight the current knowledge regarding TRPC implication in different cellular processes related to ischemia and reperfusion and to heart infarction
Introducción a la taxonomía
La Taxonomía, entendida como la teoría y práctica de la clasificación de los seres vivos, da sustento y nutre muchas otras ramas de la Biología. La práctica de esta disciplina, en su forma moderna, se remonta a mediados del siglo XVIII cuando se incorporó el concepto de Systema, para referirse al ordenamiento de los seres vivos, y la nomenclatura binominal de las especies dentro de un sistema jerárquico llevada a cabo por el botánico sueco Carlos Linneo (1753, 1758). La práctica de la Taxonomía comprende tanto la identificación, nominación y descripción de especies (microtaxonomía), como la clasificación de grupos taxonómicos mayores (macrotaxonomía). En nuestros días, esta disciplina enfrenta el desafío de incorporar nuevos métodos y técnicas de manejo y análisis de datos tanto a nivel de la micro como de la macrotaxonomía. Los métodos y técnicas de obtención de datos taxonómicos, su contrastación e interpretación están sometidos a un cambio drástico. Así, la identificación, caracterización, clasificación de las especies, y el análisis de sus relaciones filogenéticas se ven favorecidos y potenciados mediante la adopción de las tecnologías digitales y el uso de la infraestructura cibernética.\nEste manual propone introducir al alumno de grado de la carrera de Biología en la práctica taxonómica, comenzando por sus prácticas más sencillas y tradicionales, hasta sus prácticas más complejas e integradas; desde el uso y construcción de claves taxonómicas dicotómicas en papel, hasta el uso de claves taxonómicas interactivas disponibles en la web; y desde la construcción manual de redes y árboles filogenéticos, hasta la construcción, búsqueda e interpretaciones de árboles filogenéticos a partir de conjuntos de datos morfológicos y moleculares. La presente contribución consta de 64 ejercitaciones distribuidas en 8 capítulos, e incluye guías para el uso de software y/o bases de datos taxonómicas como material suplementario.Serie Libros de Cátedr
Isotopic labelling-based analysis elucidates biosynthesis pathways in Saccharomyces cerevisiae for Melatonin, Serotonin and Hydroxytyrosol formation
Yeasts can synthetise bioactive compounds such as Melatonin (MEL), Serotonin (SER) and Hydroxytyrosol (HT). Deciphering the mechanisms involved in their formation can lead to exploit this fact to increase the bioactive potential of fermented beverages. Quantitative analysis using labelled compounds, 15-N2 l-tryptophan and 13-C tyrosine, allowed tracking the formation of the above-mentioned bioactive compounds during the alcoholic fermentation of synthetic must by two different Saccharomyces cerevisiae strains. Labelled and unlabelled MEL, SER and HT were undoubtedly identified and quantified by High Resolution Mass Spectrometry (HRMS). Our results prove that there are at least two pathways involved in MEL biosynthesis by yeast. One starts with tryptophan as precursor being known for the vertebrates’ pathway. Additionally, MEL is produced from SER which in turn is consistent with the plants’ biosynthesis pathway. Concerning HT, it can be formed both from labelled tyrosine and from intermediates of the Erlich pathway.Ministerio de Economía y Competitividad AGL2016-77505-C3-2-RMinisterio de Ciencia, Innovación y Universidades PID2019-108722RB-C32Junta de Andalucía, Consejería de Economía y Conocimiento P18-RT-309
Influence of Large Periods of DC Current Injection in c-Si Photovoltaic Panels
Nowadays, electroluminescence imaging (Eli) appears as an emerging technique in the maintenance of
photovoltaic (PV) plants. There is a concern about how the current injection needed in ELi measurements can affect the PV modules service life, and how these periodical inspections can affect the long term life of the modules. In order to give a practical answer to this problem, a series of tests consisting of long periods of current injection on several monocrystalline silicon modules has been carried out. The modules tested had already fulfilled their useful life and present multiple defects. In order to analyze how the current injection affects the state of the module, images of infrared thermography (IRT) and ELi were acquired during the current injection period. The subsequent analysis of these images shows only a small effect during the heating period in the EL intensity results at the beginning of each test, not affecting the module performance.Proyecto de Investigación ENE2017-89561-C4-3-R (MCIN)Proyecto de Investigación RTC-2017-6712-3 (MCIN)Proyecto de Investigación VA283P18 (Junta de Castilla y León
Cyclometalated Iminophosphorane Gold(III) and Platinum(II) Complexes. A Highly Permeable Cationic Platinum(II) Compound with Promising Anticancer Properties
New organometallic gold(III) and platinum(II) complexes containing iminophosphorane ligands are described. Most of them are more cytotoxic to a number of human cancer cell lines than cisplatin. Cationic Pt(II) derivatives 4 and 5, which differ only in the anion, Hg2Cl62– or PF6– respectively, display almost identical IC50 values in the sub-micromolar range (25–335-fold more active than cisplatin on these cell lines). The gold compounds induced mainly caspase-independent cell death, as previously reported for related cycloaurated compounds containing IM ligands. Cycloplatinated compounds 3, 4, and 5 can also activate alternative caspase-independent mechanisms of death. However, at short incubation times cell death seems to be mainly caspase dependent, suggesting that the main mechanism of cell death for these compounds is apoptosis. Mercury-free compound 5 does not interact with plasmid (pBR322) DNA or with calf thymus DNA. Permeability studies of 5 by two different assays, in vitro Caco-2 monolayers and a rat perfusion model, have revealed a high permeability profile for this compound (comparable to that of metoprolol or caffeine) and an estimated oral fraction absorbed of 100%, which potentially makes it a good candidate for oral administration
Development and characterization of cell models harbouring mtDNA deletions for <i>in vitro</i> study of Pearson syndrome
Pearson syndrome is a rare multisystem disease caused by single large-scale mitochondrial DNA deletions (SLSMDs). The syndrome presents early in infancy and is mainly characterised by refractory sideroblastic anaemia. Prognosis is poor and treatment is supportive, thus the development of new models for the study of Pearson syndrome and new therapy strategies is essential. In this work, we report three different cell models carrying an SLMSD: fibroblasts, transmitochondrial cybrids and induced pluripotent stem cells (iPSCs). All studied models exhibited an aberrant mitochondrial ultrastructure and defective oxidative phosphorylation system function, showing a decrease in different parameters, such as mitochondrial ATP, respiratory complex IV activity and quantity or oxygen consumption. Despite this, iPSCs harbouring ‘common deletion’ were able to differentiate into three germ layers. Additionally, cybrid clones only showed mitochondrial dysfunction when heteroplasmy level reached 70%. Some differences observed among models may depend on their metabolic profile; therefore, we consider that these three models are useful for the in vitro study of Pearson syndrome, as well as for testing new specific therapies.
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Prokaryotic Community Structure and Metabolisms in Shallow Subsurface of Atacama Desert Playas and Alluvial Fans After Heavy Rains: Repairing and Preparing for Next Dry Period
The Atacama Desert, the oldest and driest desert on Earth, displays significant rains only once per decade. To investigate how microbial communities take advantage of these sporadic wet events, we carried out a geomicrobiological study a few days after a heavy rain event in 2015. Different physicochemical and microbial community analyses were conducted on samples collected from playas and an alluvial fan from surface, 10, 20, 50, and 80 cm depth. Gravimetric moisture content peaks were measured in 10 and 20 cm depth samples (from 1.65 to 4.1% w/w maximum values) while, in general, main anions such as chloride, nitrate, and sulfate concentrations increased with depth, with maximum values of 13-1,125; 168-10,109; and 9,904-30,952 ppm, respectively. Small organic anions such as formate and acetate had maximum concentrations from 2.61 to 3.44 ppm and 6.73 to 28.75 ppm, respectively. Microbial diversity inferred from DNA analysis showed Actinobacteria and Alphaproteobacteria as the most abundant and widespread bacterial taxa among the samples, followed by Chloroflexi and Firmicutes at specific sites. Archaea were mainly dominated by Nitrososphaerales, Methanobacteria, with the detection of other groups such as Halobacteria. Metaproteomics showed a high and even distribution of proteins involved in primary metabolic processes such as energy production and biosynthetic pathways, and a limited but remarkable presence of proteins related to resistance to environmental stressors such as radiation, oxidation, or desiccation. The results indicated that extra humidity in the system allows the microbial community to repair, and prepare for the upcoming hyperarid period. Additionally, it supplies biomarkers to the medium whose preservation potential could be high under strong desiccation conditions and relevant for planetary exploration.Spanish Ministerio de Economia y Competitividad/Fondo Europeo de Desarrollo Regional Grants [ESP2014-58494-R, ESP2015-69540-R, ESP2017-89053-C2-2-P]; NASA ASTEP "Life in the Atacama (LITA)" project [NNX11AJ87G]; NASA Astrobiology Institute Colaborative Agreement 7 (CAN-7) project [NNX15BB01A]; Comunidad de Madrid/European Union YEI program; Spanish Ministry of Economy and Competitivity (MINECO); "Maria de Maeztu" program [MDM-2017-0737]Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
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