2,218 research outputs found
Modelling the burden caused by gene expression: an in silico investigation into the interactions between synthetic gene circuits and their chassis cell
In this paper we motivate and develop a model of gene expression for the
purpose of studying the interaction between synthetic gene circuits and the
chassis cell within which they are in- serted. This model focuses on the
translational aspect of gene expression as this is where the literature
suggests the crucial interaction between gene expression and shared resources
lies
Gastrointestinal parasites of feral cats from Christmas Island
Objective To investigate the gastrointestinal parasites present in feral cats on Christmas Island, with particular interest in the protozoan parasite Toxoplasma gondii. Procedure Faecal and serum samples were collected from 28 and 25 cats respectively that were trapped as part of an ongoing eradication program being run on Christmas Island by the Department of Environment and Conservation. Faecal samples were screened microscopically for helminth and protozoan parasites. Serum samples were screened for antibodies to T gondii using a commercial indirect immunofluorescence assay (IFA) and a latex agglutination test (LAT). Results The most common helminth parasites detected were Toxocara cati (present in 15 of 28 faecal samples), Strongyloides sp (13/28), Aelurostrongylus abstrusus, (7/28), an unidentified capillarid (6/28) and Ancylostoma sp (4/28). Based on serology, T gondii was the most common parasite detected (protozoan or otherwise) with antibodies detected in 24 serum samples by IFA and 23 serum samples by LAT. Conclusion Cats on Christmas Island harbour many of the helminth and protozoan parasites reported from feral cats elsewhere in Australia. The high seroprevalence of T gondii in these cats indicates a high level of exposure to the parasite in this environment
Metabolomic characterization of strawberry cultivars during postharvest
The cultivated strawberry (Fragaria x ananassa) is the berry most consumed worldwide and is well-known for its delicate flavour and nutritional characteristics. However, strawberries possess a very short postharvest shelf-life due to their high respiration rate and their susceptibility to water loss, mechanical damage and fungi deterioration. Extension of fruit shelf-life is a major economic goal, and measures are commercially taken to delay senescence. These procedures include low temperature, controlled atmosphere and/or chemical treatments, being the first one the most commonly applied. To improve our understanding of the molecular and biochemical mechanisms underlying the deterioration of fruit quality attributes during senescence, we monitored the metabolomic profiles of five commercial strawberry cultivars under different postharvest treatments. Ripe fruits of F x ananassa cv. ‘Amiga’, ‘Camarosa’, ‘Candonga’, ‘Fortuna’ and ‘Santa Clara’ were harvested and kept at 4ºC during three, six and ten days in normal, CO2-enriched and O3-enriched atmospheres. We used a combination of GC-TOF-MS, LC-MS and GC-SPME-MS to identify and semi-quantify 49 primary metabolites (sugars, amino and organic acids), 132 polar secondary metabolites and 70 volatile compounds in all different treatments along postharvest stages. Multivariate statistical approaches, including hierarchical cluster analysis, partial least squares discriminant analyses and k-means clustering, were used to characterize the variation in metabolite content during the strawberry fruit postharvest life and to identify the biochemical pathways which are most affected in the senescence processes. Here, we present the main changes in volatile compounds, primary and secondary metabolites as a consequence of postharvest storage, highlighting the differences between cultivars and treatments. Network-based methods will allow us to point out the regulatory factors and molecular mechanisms underlying fruit senescence.Universidad de Málaga. Campus de Excelencia Internacional AndalucÃa Tech
The knowledge and attitude of family members who have receIved predictive genetic test results for hereditary nonpolyposis colorectal cancer in South Africa
Includes bibliographical references (leaves 134-145).Predictive genetic testing for hereditary nonpolyposis colorectal cancer (HNPC) has been offered to families with known mutations in South Africa since 1997. The aim of this study is to evaluate the benefits and limitations, as perceived by family members, of the current management of inherited colorectal cancer
Stretched to the limit : leaf tensile properties and lignin content of resurrection plants
Leaf tensile strength was measured for four resurrection plants, Craterostigma wilmsii Engl, Xerophyta schlecteri (Baker) N.L. Menezes, Xerophyta humilis (Baker) T. Durand & Schinz and Sporobolus stapfianus Gandoger, as well as two desiccation-sensitive controls, Zea mays L. and Arabidopsis thaliana (L.) Heynh. (ecotype Columbia) at full hydration and after dehydration, both on the plant (naturally-dried) and rapidly off the plant causing death (flash-dried). In the desiccation-tolerant plants, leaf tensile strength was higher in the monocots than the dicots at full hydration. Three different mechanisms of cell protection occur in resurrection plants on drying: cell-wall folding, packing vacuoles with non-aqueous solute or a combination of the two. Tensile strength in C. wilmsii ( dicot) increased when naturally-dried but decreased when flash-dried, possibly due to the nature of the drying mechanisms (wall folding). The, leaf tensile strength of the Xerophyte species, both monocots, increased when naturally dried and when flashdried. Xerophyte species pack their vacuoles during desiccation. S. stapfianus, a grass which uses a combination of wall folding and vacuole packing, had the highest tensile strength possibly due to its unique architectural structure. Differences in leaf architecture, in terms of lignin content, were examined using light microscopy after histo-chemical staining for lignin, which showed that monocotyledons had a higher percentage of lignin per unit leaf cross-sectional area than dicotyledons. A regression analysis revealed that leaf tensile strength and lignin content were positively correlated in fully hydrated leaves I but no relationship existed between lignin content and naturally dried leaves. This may be due to variations of protective mechanisms induced during desiccation by the four resurrection plants. Notching was observed in X schlechteri, behaving differently to grasses which are notch-insensitive, possibly due to large lignin contents on the outer edges of the leaves
Determinants of gemmae output in the liverwort Lophozia ventricosa
The spacial variation and population parameters affecting gemmae output of a boreal and arctic liverwort species, Lophozia ventricosa, were studied in Trnndelag, a boreal region of central Norway and in the arctic tundra on Svalbard. The population parameters investigated included colony size, colony shoot density, number of gemmae per shoot, proportion of gemmiferous shoots and gemmiferous shoot density. The gemmae output in a colony was calculated as the product of the number of gemmae per shoot, colony size and gemmifeorus shoot density. A Nested Analysis of Variance was used to partition population parameters spacially and a Pearsons Product-Moment Correlation was used to evaluate which of these population parameters affect gemmae output in a colony. The number of gemmae per shoot differed significantly between areas, populations and colonies, and was significantly varied between populations and colonies on Svalbard. No significant variation in the number of gemmae per shoot was found in Trnndelag. Population influences on shoot density, gemmiferous shoot density and gemmae output were significant in Trnndelag. This was expected, as more shoots in a colony is thought to influence gemmiferous shoot density and gemmae output. In Trnndelag, the only significant relation that can explain gemmae output is colony size whereas on Svalbard, gemmae output in a colony is affected by colony size, shoot density and number of gemmae per shoot. The results indicate that most of the variation in gemmae output occurs at the population level and that gemmae output differs between the arctic and boreal regions
Relación entre la enseñanza de lenguas y el funcionamiento cerebral
Treball Final de Grau en Mestre o Mestra d'Educació Primà ria. Codi: MP1040. Curs acadèmic: 2016/2017It was disturbing to the fact that in current society, all have a scientific basis, but, however, education is not the best example of this fact. The education laws and who is available to them is not concerned with the needs of the learner, even not to equip teachers and future teachers of the training required implementing real pedagogies. Therefore, in the present work, spoke of the utopian alliance between neuroscience and psychology, for the teaching of languages, especially the L2. I walked in topics in neuroscience, psychological and social services necessary for the beneficial development of language skills. I stood at a critical stance of the education of the languages in Spain and how relevant information and practice mentioned several pedagogical practices that have proven to be fruitful for the learning of the L1 and L2. With this work I try to show a part of the education essential to our formation with the idea of dealing with the problems and situations that may create in language learning. Not only of this discipline but in general education. And that science has shown that the process of learning has very specific characteristics and as teachers we must know them to exploit and develop the full potential of students.Resulta inquietante el hecho de que en la sociedad actual todo tenga una base cientÃfica, pero, sin embargo, la educación no es el mejor ejemplo de este hecho. Las leyes educativas y quien se dispone a hacerlas no se preocupa por las necesidades del educando, ni por dotar a los docentes y futuros docentes de la formación requerida para poner en práctica pedagogÃas reales. Por eso, en el presente trabajo hablo de la utópica alianza entre la neurociencia y la psicologÃa, para la enseñanza de lenguas, sobre todo las L2. Me encamino en temas neurocientÃficos, psicológicos y sociales necesario para el beneficioso desarrollo de las competencias lingüÃsticas. Me sitúo en una postura crÃtica de la educación de las lenguas en España y como información relevante y práctica menciono varias practicas pedagógicas que han demostrado ser fructÃferas para el aprendizaje de las L1 y L2. Con este trabajo intento mostrar una parte de la educación esencial para nuestra formación ante la idea de abordar los problemas y situaciones que se puedan crear en el aprendizaje de lenguas. Y ya no solo de esta disciplina sino en la enseñanza en general. Y a que la ciencia ha demostrado que el proceso de aprendizaje tiene unas caracterÃsticas muy especÃficas y como docentes debemos conocerlas para aprovechar y desarrollar al máximo el potencial de los estudiantes
Recent trends in analytical methods to determine new psychoactive substances in hair
New Psychoactive Substances (NPS) belong to several chemical classes, including phenethylamines, piperazines, synthetic cathinones and synthetic cannabinoids. Development and validation of analytical methods for the determination of NPS both in traditional and alternative matrices is of crucial importance to study drug metabolism and to associate consumption to clinical outcomes and eventual intoxication symptoms. Among different biological matrices, hair is the one with the widest time window to investigate drug-related history and demonstrate past intake. The aim of this paper was to overview the trends of the rapidly evolving analytical methods for the determination of NPS in hair and the usefulness of these methods when applied to real cases. A number of rapid and sensitive methods for the determination of NPS in hair matrix has been recently published, most of them using liquid chromatography coupled to mass spectrometry. Hair digestion and subsequent solid phase extraction or liquid-liquid extraction were described as well as extraction in organic solvents. For most of the methods limits of quantification at picogram per milligram hair were obtained. The measured concentrations for most of the NPS in real samples were in the range of picograms of drug per milligram of hair. Interpretation of the results and lack of cut-off values for the discrimination between chronic consumption and occasional use or external contamination are still challenging. Methods for the determination of NPS in hair are continually emerging to include as many NPS as possible due to the great demand for their detection
El consum matern de substà ncies d'abús pot provocar canvis adversos en la placenta
Investigadors de la UAB han realitzat un estudi en el que controlant el creixement de més de dues-centes placentes han pogut apreciar canvis en els vasos sanguinis d'aquestes deguts al consum matern de substà ncies d'abús, com el tabac o l'alcohol. Aquests canvis porten a una baixa aportació de sang a la placenta i al fetus, provocant aixà un ambient pobre en oxigen. Aquest tipus de canvis adversos es poden donar abans, durant i fins i tot, després del naixement. Segons aquests investigadors, calen més estudis per entendre millor els mecanismes pels quals el consum d'aquestes substà ncies en les mares provoca una disminució en pes i talla en els acabats de néixer.Investigadores de la UAB han realizado un estudio en el que controlando el crecimiento de más de doscientas placentas han podido apreciar cambios en los vasos sanguÃneos de estas debidos al consumo de sustancias de abuso, como el tabaco o el alcohol por de la madre. Estos cambios llevan a una baja aportación de sangre a la placenta y al feto, provocando asà un ambiente pobre en oxÃgeno. Este tipo de cambios adversos se pueden dar antes, durante e incluso después del nacimiento. Según estos investigadores, se necesitan más estudios para entender mejor los mecanismos por los que el consumo de estas sustancias en las madres provoca una disminución en peso y talla en los recién nacidos
Els fetus pateixen els efectes de la nicotina
El consum de tabac durant l'embarà s exposa al fetus a possibles efectes deleteris de la nicotina que poden afectar els resultats perinatals i la salut del nen. La nicotina sembla afectar el desenvolupament neurològic normal del fetus al principi de la vida. A més, s'ha observat que l'exposició del fetus dins de l'úter al consum de tabac per part de la mare podria induir una sÃndrome d'abstinència neonatal a la nicotina.El consumo de tabaco durante el embarazo expone al feto a posibles efectos dañinos de la nicotina que pueden afectar a los resultados perinatales y a la salud del niño. La nicotina parece afectar el desarrollo neurológico normal del feto al principio de la vida. Además, se ha observado que la exposición del feto, dentro del útero, al consumo de tabaco por parte de la madre podrÃa inducir un sÃndrome de abstinencia neonatal a la nicotina
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