998 resultados para leaf epidermal features
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Land plants have developed a cuticle preventing uncontrolled water loss. Here we report that an ATP-binding cassette (ABC) subfamily G (ABCG) full transporter is required for leaf water conservation in both wild barley and rice. A spontaneous mutation, eibi1.b, in wild barley has a low capacity to retain leaf water, a phenotype associated with reduced cutin deposition and a thin cuticle. Map-based cloning revealed that Eibi1 encodes an HvABCG31 full transporter. The gene was highly expressed in the elongation zone of a growing leaf (the site of cutin synthesis), and its gene product also was localized in developing, but not in mature tissue. A de novo wild barley mutant named "eibi1.c," along with two transposon insertion lines of rice mutated in the ortholog of HvABCG31 also were unable to restrict water loss from detached leaves. HvABCG31 is hypothesized to function as a transporter involved in cutin formation. Homologs of HvABCG31 were found in green algae, moss, and lycopods, indicating that this full transporter is highly conserved in the evolution of land plants.
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Advances in wound care are of great importance in clinical injury management. In this respect, the nuclear receptor peroxisome proliferator-activated receptor (PPAR)beta/delta occupies a unique position at the intersection of diverse inflammatory or anti-inflammatory signals that influence wound repair. This study shows how changes in PPARbeta/delta expression have a profound effect on wound healing. Using two different in vivo models based on topical application of recombinant transforming growth factor (TGF)-beta1 and ablation of the Smad3 gene, we show that prolonged expression and activity of PPARbeta/delta accelerate wound closure. The results reveal a dual role of TGF-beta1 as a chemoattractant of inflammatory cells and repressor of inflammation-induced PPARbeta/delta expression. Also, they provide insight into the so far reported paradoxical effects of the application of exogenous TGF-beta1 at wound sites.
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Biological features and social preferences have been studied separately as factors influencing human strategic behaviour. We run two studies in order to explore the interplay between these two sets of factors. In the first study, we investigate to what extent social preferences may have some biological underpinnings. We use simple one-shot distribution experiments to attribute subjects one out of four types of social preferences: Self-interested (SI), Competitive (C), Inequality averse (IA) and Efficiency-seeking (ES). We then investigate whether these four groups display differences in their levels of facial Fluctuating Asymmetry (FA) and in proxies for exposure to testosterone during phoetal development and puberty. We observe that development-related biological features and social preferences are relatively independent. In the second study, we compare the relative weight of these two set of factors by studying how they affect subjects’ behaviour in the Ultimatum Game (UG). We find differences in offers made and rejection rates across the four social preference groups. The effect of social preferences is stronger than the effect of biological features even though the latter is significant. We also report a novel link between facial masculinity (a proxy for exposure to testosterone during puberty) and rejection rates in the UG. Our results suggest that biological features influence behaviour both directly and through their relation with the type of social preferences that individuals hold.
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The present paper analyzes the extent to which attractiveness-related variables affect cooperative behavior in women. Cooperativeness is evaluated through a Prisoner's Dilemma Game (PDG). We consider several morphometric variables related to attractiveness: Fluctuating Asymmetry (FA), Waist-Hip Ratio (WHR, Body Mass Index (BMI) and Facial Femininity (FF). These variables have been shown to predict human behavior. We also include as a control variable a score for Self-Perceived Attractiveness (SPA). We test differences in these variables according to behavior in the PDG. Our results reveal that low FA women cooperate less frequently in the PDG. We also find that women with lower WHR are more cooperative. This result contradicts the expected relation between WHR and behavior in the PDG. We show that this effect of WHR on cooperation operates through its influence on the expectation that participants hold on the cooperative intent of their counterpart. In addition, we show that the effect of attractive features on cooperation occurs independently of the participants' perception of their own appeal. Finally, we discuss our results in the context of the evolution of cooperative behavior and under the hypothesis that attractiveness is a reliable indicator of phenotypic quality.
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Purpose: 1. To provide an overview of the different types of internal hernia (IH) occurring after laparoscopic Roux-en-Y gastric bypass (LRYGBP) performed for morbid obesity. 2. To describe the correspondent MDCT features in relation with the underlying anatomical landmarks in order to differentiate their localisation and to direct the surgeon during following laparoscopic closure of mesenteric defects. Methods and materials: LRYGBP performed for morbid obesity is associated with less perioperative complications, shorter hospital stay and a more rapid recovery compared with the open surgical procedure. However, a relatively high incidence of IH is seen that may be due to the laparoscopic approach, but also caused by rapid weight loss with consecutive loosening of the mesenteric sutures. Results: After briefly reviewing the surgical procedure of LRYGBP (ante- versus retrocolic) we describe the exact anatomical landmarks of the different types of IH occurring at any time after operation: They are caused by surgical defects either at the level of the transverse colon mesentery, at the Petersen's space, which represents an opening between the mesocolon and jejunal mesentery, or at the enteroenterostomy site. Typical MDCT features of each IH type in axial and coronal plane as well as targeted vascular reconstructions are demonstrated. Conclusion: Exact knowledge about underlying pathophysiology and anatomical landmarks is essential for distinguishing the different types of IH occurring after LRYGBP on MDCT, since radiological features are difficult to recognize and may even overlap. The radiologist should be aware of the potential anatomic sites to ensure subsequent straightforward laparoscopic exploration.
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Multidetector row computed tomography (MDCT) is the imaging modality of reference for the diagnosis of bronchiectasis. MDCT may also detect a focal stenosis, a tumor or multiple morphologic abnormalities of the bronchial tree. It may orient the endoscopist towards the abnormal bronchi, and in all cases assess the extent of the bronchial lesions. The CT findings of bronchial abnormalities include anomalies of bronchial division and origin, bronchial stenosis, bronchial wall thickening, lumen dilatation, and mucoid impaction. The main CT features of bronchiectasis are increased bronchoarterial ratio, lack of bronchial tapering, and visibility of peripheral airways. Other bronchial abnormalities include excessive bronchial collapse at expiration, outpouchings and diverticula, dehiscence, fistulas, and calcifications.
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Climate change has been taking place at unprecedented rates over the past decades. These fast alterations caused by human activities are leading to a global warming of the planet. Warmer temperatures are going to have important effects on vegetation and especially on tropical forests. Insects as well will be affected by climate change. This study tested the hypothesis that higher temperatures lead to a higher insect pressure on vegetation. Visual estimations of leaf damage were recorded and used to assess the extent of herbivory in nine 0.1ha plots along an altitudinal gradient, and therefore a temperature gradient. These estimations were made at both a community level and a species level, on 2 target species. Leaf toughness tests were performed on samples from the target species from each plot. Results showed a strong evidence of increasing insect damage along increasing temperature, with no significant effect from the leaf toughness.
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This work covers two aspects. First, it generally compares and summarizes the similarities and differences of state of the art feature detector and descriptor and second it presents a novel approach of detecting intestinal content (in particular bubbles) in capsule endoscopy images. Feature detectors and descriptors providing invariance to change of perspective, scale, signal-noise-ratio and lighting conditions are important and interesting topics in current research and the number of possible applications seems to be numberless. After analysing a selection of in the literature presented approaches, this work investigates in their suitability for applications information extraction in capsule endoscopy images. Eventually, a very good performing detector of intestinal content in capsule endoscopy images is presented. A accurate detection of intestinal content is crucial for all kinds of machine learning approaches and other analysis on capsule endoscopy studies because they occlude the field of view of the capsule camera and therefore those frames need to be excluded from analysis. As a so called “byproduct” of this investigation a graphical user interface supported Feature Analysis Tool is presented to execute and compare the discussed feature detectors and descriptor on arbitrary images, with configurable parameters and visualized their output. As well the presented bubble classifier is part of this tool and if a ground truth is available (or can also be generated using this tool) a detailed visualization of the validation result will be performed.
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Optical and electron microscopical evidences of focal matrix degradation were frequently seen in liver sections taken from patients with periportal ("pipe-stem") fibrosis caused by schistosomiasis mansoni. Besides present of focal areas of rarefaction, fragmentation and dispersion of collagen fibers, the enlargend portal spaces also showed hyperplasia of elastic tisue and disarray of smooth muscle fibers following the destrution of portal vein branches. Ultrastructural cahnges represented by focal lytic and/or electron dense alterations of colagen fibrils were similar to those first seen in experimental material and designated as "chronic collagen degradation". Elastin and related microfibrils were also affected by focal condensation, fragmentation, distorsion and dissolution. Schistosome eggs were scanty in the tissue sections examined. Matrix degradation represented involuting changes related to the progressive diminution of parasite aggression, which occurs spontaneously with age or after cure by chemotherapy. Changes of focal matrix degradation now being described represent the basic morphological counterpart of periportal fibrosis involution documented clinically, especially by ultrasonography, in patients with hepatosplenic schistosomiasis submitted to curative chemotherapy.
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Achievements and successes have been obtained in schistosomiasis control in China. An epidemic survey was carried out and its results analyzed.
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Some bacteria have the capacity to reduce incidence and severity of plant diseases either by inhibiting the pathogen or by modulating the resistance response of the plant. Plants dispose of different resistance mechanisms that are influenced by the biotic and abiotic environment. The present experiments explored the effects of biocontrol strains of Pseudomonas fluorescens on the resistance of wheat varieties against brown rust disease caused by Puccinia triticina. Root inoculation with biocontrol pseudomonads reduced the disease severity on the leaves. The plant response depended on the genotype of both the microbes and the wheat varieties, suggesting a straight interaction at the molecular level.
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According to the IPCC (2007), the Mediterranean basin is expected to suffer important changes in temperature and precipitation in the next few decades, leading the climate warmer and dryer. Therefore, it is necessary to determine the possible effects of increased drought on species with different structural and physiological traits, to be able to predict possible changes in the structure and composition of Mediterranean forests. Moreover, it will be necessary to assess whether traditional management practices can mitigate the effects of climate change on these forests. The main aim of this study has been to analyze the effects of increased drought on the mortality, growth and resprouting patterns of two co-occurring Mediterranean oak species with contrasting leaf habit (the evergreen Quercus ilex and the winter-deciduous Quercus cerrioides), and to assess the effects of selective thinning on their response to increased drought. Our results show a differential effect of increased drought between species: no differences were observed in the growth of Q. ilex while Q. cerrioides reduced its growth under increased drought conditions. Selective thinning reduced the negative effects of increased drought on tree growth, although this beneficial effect tended to decrease during the experiment. Our results show that increasing aridity in Mediterranean areas can be a constraining factor for deciduous oaks, thus potentially causing their decline in mixed forests and favouring their substitution by the evergreen congeneric species. However, as seen in this study, management can strongly encourage growth both for deciduous and evergreen species, thus reversing the effects of increased water stress on Mediterranean coppices.