27 resultados para Mosaic

em BORIS: Bern Open Repository and Information System - Berna - Suiça


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Soilborne wheat mosaic virus (SBWMV) is one of the most important winter wheat pathogens worldwide. To identify genes for resistance to the virus in U.S. winter wheat, association study was conducted using a selected panel of 205 elite experimental lines and cultivars from U.S. hard and soft winter wheat breeding programs. Virus symptoms were evaluated twice in virus-infected fields for the panel at Manhattan, KS in spring 2010 and 2011 and for a subpanel of 137 hard winter wheat accessions at Stillwater, OK in spring 2008. At the two locations, 69.8 and 79.5% of cultivars were resistant or moderately resistant to the disease, respectively. After 282 simple-sequence repeat markers covering all wheat chromosome arms were scanned for association in the panel, marker Xgwm469 on the long arm of chromosome 5D (5DL) showed a significant association with the disease rating. Three alleles (Xgwm469-165bp, -167bp, and -169bp) were associated with resistance and the null allele was associated with susceptibility. Correlations between the marker and the disease rating were highly significant (0.80 in Manhattan at P < 0.0001 and 0.63 in Stillwater at P < 0.0001). The alleles Xgwm469-165bp and Xgwm469-169bp were present mainly in the hard winter wheat group, whereas allele Xgwm469-167bp was predominant in the soft winter wheat. The 169 bp allele can be traced back to 'Newton', and the 165 bp allele to Aegilops tauschii. In addition, a novel locus on the short arm of chromosome 4D (4DS) was also identified to associate with the disease rating. Marker Xgwm469-5DL is closely linked to SBWMV resistance and highly polymorphic across the winter wheat accessions sampled in the study and, thus, should be useful in marker-assisted selection in U.S. winter wheat.

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One Arabian and 5 Hungarian half-bred horses were used to study the macroscopic and microscopic survival of autologous osteochondral grafts in the weight-bearing surface of the medial femoral condyle (MFC). Grafts were harvested from the cranial surface of the medial femoral trochlea (MFT) under arthroscopic control. Three of them were transplanted into the weight-bearing surface of the contralateral MFC using an arthrotomy approach. Three months later this transplantation procedure was repeated on the opposite stifle joints in the same animals, but at that time transplantation was performed arthroscopically. Follow-up arthroscopy was carried out 12 months after the first operations, and biopsies were taken from both the recipient and the donor sites for histological examination. During follow-up arthroscopy, the transplanted areas looked congruent and smooth. Microscopically, the characteristics of hyaline cartilage were present in 5 out of the 10 biopsies examined; however, in the other half of biopsies glycosaminoglycan (GAG) loss and change in the architecture of the transplanted cartilage was observed. In a 16-year-old horse, all grafts broke during harvesting, and thus transplantation was not performed. No radiological signs of osteoarthritic changes were detected 9 to 12 months after the operations in the donor and recipient joints. Clinically, no lameness or effusion was present three months after the transplantations.

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The pathophysiology of mucosal changes observed in infants with chronic protracted diarrhea is poorly understood. We report on two brothers suffering from a special form of sucrase isomaltase (SI) deficiency. The children presented with weight loss and dyspepsia after sucrose exposition. We performed an H respiration test, which showed a pathologic result in the younger brother. Analysis of the brush border enzyme activities showed low expression of lactase and SI. Immunoelectron microscopy of duodenal biopsies showed an isolated SI deficiency in a mosaic pattern [e.g., 42% (14%) crypt enterocytes and 64% (59%) villus enterocytes with decreased amounts of SI on microvilli], whereas lactase and aminopeptidase n (ApN) were present at the apical membrane of all cells in a normal range. The SI mosaic pattern of these patients shows that the enterocytes contain low amounts of SI on the apical membrane but express normal quantities of other disaccharidases. These findings suggest the existence of different clonal expressions or specific (posttranslational) mechanisms of postGolgi transportation for individual brush border enzymes. It remains unresolved whether the mosaic distribution is part of a normal maturation process or caused by a lack of an overall control mechanism in the expression of brush border hydrolases.

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The north-eastern escarpment of Madagascar contains the island’s last remaining large-scale humid forest massifs surrounded by diverse small-scale agricultural mosaics. There is high deforestation mainly caused by shifting cultivation practiced by local land users to produce upland rice for subsistence. Today, large protected areas restrict land users’ access to forests to collect wood and other forest products. Moreover, they are no more able to expand their cultivated land, which leads to shorter shifting cultivation cycles and decreasing plot sizes for irrigated rice and cash crop cultivation. Cash crop production of clove and vanilla is exposed to risks such as extreme inter-annual price fluctuations, pests and cyclones. In the absence of work opportunities, agricultural extension services and micro-finance schemes people are stuck in a poverty trap. New development strategies are needed to mitigate the trade-offs between forest conservation and human well-being. As landscape composition and livelihood strategies vary across the region, these strategies need to be spatially differentiated to avoid implementing generic solutions, which do not fit the local context. However, up to date, little is known about the spatial patterns of shifting cultivation and other land use systems at the regional level. This is mainly due to the high spatial and temporal dynamics inherent to shifting cultivation, which makes it difficult to monitor the dynamics of this land use system with remote sensing methods. Furthermore, knowledge about land users’ livelihood strategies and the risks and opportunities they face stems from very few local case studies. To overcome this challenge, firstly, we used remote sensing data and a landscape mosaic approach to delineate the main landscape types at the regional level. Secondly, we developed a land user typology based on socio-ecological data from household surveys in 45 villages spread throughout the region. Combining the land user typology with the landscape mosaic map allowed us to reveal spatial patterns of the interaction between landscapes and people and to better understand the trade-offs between forest conservation and local wellbeing. While shifting cultivation systems are being transformed into more intensive permanent agricultural systems in many countries around the globe, Madagascar seems to be an exception to this trend. Linking land cover information to human-environmental interactions over large areas is crucial to designing policies and to inform decision making for a more sustainable development of this resource-rich but poverty-prone context.

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Due to its extraordinary biodiversity and rapid deforestation, north-eastern Madagascar is a conservation hotspot of global importance. Reducing shifting cultivation is a high priority for policy-makers and conservationists; however, spatially explicit evidence of shifting cultivation is lacking due to the difficulty of mapping it with common remote sensing methods. To overcome this challenge, we adopted a landscape mosaic approach to assess the changes between natural forests, shifting cultivation and permanent cultivation systems at the regional level from 1995 to 2011. Our study confirmed that shifting cultivation is still being used to produce subsistence rice throughout the region, but there is a trend of intensification away from shifting cultivation towards permanent rice production, especially near protected areas. While large continuous forest exists today only in the core zones of protected areas, the agricultural matrix is still dominated by a dense cover of tree crops and smaller forest fragments. We believe that this evidence makes a crucial contribution to the development of interventions to prevent further conversion of forest to agricultural land while improving local land users' well-being.

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The aim of this article is to disclose the characteristics of postmortem forensic imaging; give an overview of the several possible findings in postmortem imaging, which are uncommon or new to clinical radiologists; and discuss the possible pitfalls. Unspecific postmortem signs are enlisted and specific signs shall be presented, which are typical for one cause of death. Unspecific signs. Livor mortis may not only be seen from the outside, but also inside the body in the lungs: in chest CT internal livor mortis appear as ground glass opacity in the dependent lower lobes. The aortic wall is often hyperdense in postmortem CT due to wall contraction and loss of luminal pressure. Gas bubbles are very common postmortem due to systemic gas embolism after major open trauma, artificial respiration or initial decomposition; in particular putrefaction produces gas bubbles globally. Specific signs. Intracranial bleeding is hyperattenuating both in radiology and in postmortem imaging. Signs of strangulation are hemorrhage in the soft tissue of the neck like skin, subcutaneous tissue, platysma muscle and lymph nodes. The "vanishing" aorta is indicative for exsanguination. Fluid in the airways with mosaic lung densities and emphysema (aquosum) is typical for fresh-water drowning.

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P>Outcrossing Arabidopsis species that diverged from their inbreeding relative Arabidopsis thaliana 5 million yr ago and display a biogeographical pattern of interspecific sympatry vs intraspecific allopatry provides an ideal model for studying impacts of gene introgression and polyploidization on species diversification. Flow cytometry analyses detected ploidy polymorphisms of 2x and 4x in Arabidopsis lyrata ssp. kamchatica of Taiwan. Genomic divergence between species/subspecies was estimated based on 98 randomly chosen nuclear genes. Multilocus analyses revealed a mosaic genome in diploid A. l. kamchatica composed of Arabidopsis halleri-like and A. lyrata-like alleles. Coalescent analyses suggest that the segregation of ancestral polymorphisms alone cannot explain the high inconsistency between gene trees across loci, and that gene introgression via diploid A. l. kamchatica likely distorts the molecular phylogenies of Arabidopsis species. However, not all genes migrated across species freely. Gene ontology analyses suggested that some nonmigrating genes were constrained by natural selection. High levels of estimated ancestral polymorphisms between A. halleri and A. lyrata suggest that gene flow between these species has not completely ceased since their initial isolation. Polymorphism data of extant populations also imply recent gene flow between the species. Our study reveals that interspecific gene flow affects the genome evolution in Arabidopsis.

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Making research relevant to development is a complex, non-linear and often unpredictable process which requires very particular skills and strategies on the part of researchers. The National Centre of Competence in Research (NCCR) North-South provides financial and technical support for researchers so that they can effectively cooperate with policy-makers and practitioners. An analysis of 10 years of experience translating research into development practise in the NCCR North-South revealed the following four strategies as particularly relevant: a) research orientation towards the needs and interests of partners; b) implementation of promising methods and approaches; c) communication and dissemination of research results; and d) careful analysis of the political context through monitoring and learning approaches. The NCCR North-South experience shows that “doing excellent research” is just one piece of the mosaic. It is equally important to join hands with non-academic partners from the very beginning of a research project, in order to develop and test new pathways for sustainable development. Capacity building – in the North and South – enables researchers to do both: To do excellent research and to make it relevant for development.

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It is a globally important challenge to meet increasing demands for resources and, at the same time, protect biodiversity and ecosystem services. Farming is usually regarded as a major threat to biodiversity due to its expansion into natural areas. We compared biodiversity of bees and wasps between heterogeneous small-scale farming areas and protected forest in northern coastal Belize, Central America. Malaise traps operated for three months during the transition from wet to dry season. Farming areas consisted of a mosaic of mixed crop types, open habitat, secondary forest, and agroforestry. Mean species richness per site (alpha diversity), as well as spatial and temporal community variation (beta diversity) of bees and wasps were equal or higher in farming areas compared to protected forest. The higher species richness and community variation in farmland was due to additional species that did not occur in the forest, whereas most species trapped in forest were also found in farming areas. The overall regional species richness (gamma diversity) increased by 70% with the inclusion of farming areas. Our results suggest that small-scale farming systems adjacent to protected forest may not only conserve, but even favour, biodiversity of some taxonomic groups. We can, however, not exclude possible declines of bee and wasp diversity in more intensified farmland or in landscapes completely covered by heterogeneous farming systems.

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The aim of this study was to identify the classic autopsy signs of drowning in post-mortem multislice computed tomography (MSCT). Therefore, the post-mortem pre-autopsy MSCT- findings of ten drowning cases were correlated with autopsy and statistically compared with the post-mortem MSCT of 20 non-drowning cases. Fluid in the airways was present in all drowning cases. Central aspiration in either the trachea or the main bronchi was usually observed. Consecutive bronchospasm caused emphysema aquosum. Sixty percent of drowning cases showed a mosaic pattern of the lung parenchyma due to regions of hypo- and hyperperfused lung areas of aspiration. The resorption of fresh water in the lung resulted in hypodensity of the blood representing haemodilution and possible heart failure. Swallowed water distended the stomach and duodenum; and inflow of water filled the paranasal sinuses (100%). All the typical findings of drowning, except Paltau's spots, were detected using post-mortem MSCT, and a good correlation of MSCT and autopsy was found. The advantage of MSCT was the direct detection of bronchospasm, haemodilution and water in the paranasal sinus, which is rather complicated or impossible at the classical autopsy.

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Oculofaciocardiodental (OFCD) and Lenz microphthalmia syndromes form part of a spectrum of X-linked microphthalmia disorders characterized by ocular, dental, cardiac and skeletal anomalies and mental retardation. The two syndromes are allelic, caused by mutations in the BCL-6 corepressor gene (BCOR). To extend the series of phenotypes associated with pathogenic mutations in BCOR, we sequenced the BCOR gene in patients with (1) OFCD syndrome, (2) putative X-linked ('Lenz') microphthalmia syndrome, (3) isolated ocular defects and (4) laterality phenotypes. We present a new cohort of females with OFCD syndrome and null mutations in BCOR, supporting the hypothesis that BCOR is the sole molecular cause of this syndrome. We identify for the first time mosaic BCOR mutations in two females with OFCD syndrome and one apparently asymptomatic female. We present a female diagnosed with isolated ocular defects and identify minor features of OFCD syndrome, suggesting that OFCD syndrome may be mild and underdiagnosed. We have sequenced a cohort of males diagnosed with putative X-linked microphthalmia and found a mutation, p.P85L, in a single case, suggesting that BCOR mutations are not a major cause of X-linked microphthalmia in males. The absence of BCOR mutations in a panel of patients with non-specific laterality defects suggests that mutations in BCOR are not a major cause of isolated heart and laterality defects. Phenotypic analysis of OFCD and Lenz microphthalmia syndromes shows that in addition to the standard diagnostic criteria of congenital cataract, microphthalmia and radiculomegaly, patients should be examined for skeletal defects, particularly radioulnar synostosis, and cardiac/laterality defects.

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Enzootic pneumonia (EP) of pigs, caused by Mycoplasma hyopneumoniae has been a notifiable disease in Switzerland since May 2003. The diagnosis of EP has been based on multiple methods, including clinical, bacteriological and epidemiological findings as well as pathological examination of lungs (mosaic diagnosis). With the recent development of a real-time PCR (rtPCR) assay with 2 target sequences a new detection method for M. hyopneumoniae became available. This assay was tested for its applicability to nasal swab material from live animals. Pigs from 74 herds (average 10 pigs per herd) were tested. Using the mosaic diagnosis, 22 herds were classified as EP positive and 52 as EP negative. From the 730 collected swab samples we were able to demonstrate that the rtPCR test was 100% specific. In cases of cough the sensitivity on herd level of the rtPCR is 100%. On single animal level and in herds without cough the sensitivity was lower. In such cases, only a positive result would be proof for an infection with M. hyopneumoniae. Our study shows that the rtPCR on nasal swabs from live pigs allows a fast and accurate diagnosis in cases of suspected EP.

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In order to improve the diagnosis of enzootic pneumonia (EP) in pigs two real-time polymerase chain reaction (rtPCR) assays for the detection of Mycoplasma hyopneumoniae in bronchial swabs from lung necropsies were established and validated in parallel. As a gold standard, the current "mosaic diagnosis" was taken, including epidemiological tracing, clinical signs, macro- and histopathological lesions of the lungs and immunofluorescence. One rtPCR is targeting a repeated DNA element of the M. hyopneumoniae genome (REP assay), the other a putative ABC transporter gene (ABC assay). Both assays were shown to be specific for M. hyopneumoniae and did not cross react with other bacteria and mollicutes from pig. With material from pigs of defined EP-negative farms the two assays showed to be 100% specific. When testing lungs from pig farms with EP, the REP assay detected 50% and the ABC assay 90% of the farms as positive. Both tests together detected all positive farms. Within a positive herd the two assays tested similarly with on average over 90% of the lung samples analysed from a single farm showing positive scores. A series of samples with suspicion of EP and samples from pigs with diseases other than respiratory taken from current routine diagnostic was assayed. None of the assays showed false positive results. The sensitivities in this sample group were 50% for the REP and 70% for the ABC assays and for both assays together 85%. The two assays run in parallel are therefore a valuable tool for the improvement of the current diagnosis of EP.