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191.
Thoracolumbar disc extrusions were diagnosed in three chondrodystrophic dogs with paraparesis of up to three days duration. All cases were managed by hemilaminectomy and removal of extruded disc material. In one dog, fenestration of the herniated disc space was also performed. Initially neurological function improved or was unchanged, but from two to ten days postoperatively clinical signs of deterioration became apparent. In all the dogs, recurrence of disc extrusion at the same location as the initial extrusion was diagnosed by computer tomography and at a second surgery abundant disc material was found at the hemilaminectomy site between the dura and an implanted graft of autogenous fat. 相似文献
192.
Fluturë Novakazi Olga Afanasenko Nina Lashina Gregory J. Platz Rod Snowdon Igor Loskutov Frank Ordon 《Plant Breeding》2020,139(3):521-535
Spot blotch caused by Bipolaris sorokiniana is an important disease in barley worldwide, causing considerable yield losses and reduced grain quality. In order to identify QTL conferring resistance to spot blotch, a highly diverse worldwide barley set comprising 449 accessions was phenotyped for seedling resistance with three isolates (No 31, SH 15 and SB 61) and for adult plant resistance at two locations (Russia and Australia) in two years. Genotyping with the 50 k iSelect barley SNP genotyping chip yielded 33,818 informative markers. Genome-wide association studies (GWAS) using a compressed mixed linear model, including population structure and kinship, revealed 38 significant marker-trait associations (MTA) for spot blotch resistance. The MTA corresponded to two major QTL on chromosomes 1H and 7H and a putative new minor QTL on chromosome 7H explaining between 2.79% and 13.67% of the phenotypic variance. A total of 10 and 14 high-confidence genes were identified in the respective major QTL regions, seven of which have a predicted involvement in pathogen recognition or defence. 相似文献
193.
Anaïs de Almeida Campos Cordeiro Sara Deambrozi Coelho Nina Celli Ramos João Augusto Alves Meira-Neto 《Agroforestry Systems》2018,92(6):1495-1505
The Serra do Brigadeiro State Park (PESB) is one of the largest fragments of Brazilian Atlantic Rainforest, and it is relevant for native species conservation. However, monocultures settled around the Park resulted in extensive open areas that facilitate the establishment of alien species on the PESB perimeter, which may threaten native species conservation therein, since biological invasion is the second main cause of global biodiversity loss. In this region, there are also farmers planting agroforestry systems (AFS), characterized by tree-based intercropping, which are structurally more similar to the Atlantic Rainforest reminiscent fragments present in the region and may limit local occurrence of potentially invasive exotic weeds for several reasons, such as the high levels of shade provided by trees, the groundcover that result from loss of tree leaves and the increased competition for belowground resources. This study aimed to test whether AFS limit exotic species establishment when compared to monoculture systems. Accordingly, three coffee monocultures and three agroforestry coffee plantations around the PESB were studied. In each of the six study areas, 30 plots of 1 m2 were established between the lines of coffee plantation, where all species present were surveyed. In both treatments, rarefaction curves were constructed to evaluate native and exotic richness, and diversity of these two categories was estimated through Simpson index inverse (1/D). All 13 sampled exotic species were present in monocultures, but only three of them occurred in AFS. Besides, alien diversity in monocultures (\(1/D\) = 2.173 ± 0.011) was significantly higher than in AFS (\(1/D\) = 1.031 ± 0.001). Such changes in alien plant community between land-use show that AFSs limit invasive species establishment. Therefore, when planted around protected areas, AFS may contribute to the control of biological invasions and to biodiversity conservation. 相似文献
194.
Silvestre García de Jalón Paul J. Burgess Anil Graves Gerardo Moreno Jim McAdam Eric Pottier Sandra Novak Valerio Bondesan Rosa Mosquera-Losada Josep Crous-Durán Joao H. N. Palma Joana A. Paulo Tania S. Oliveira Eric Cirou Yousri Hannachi Anastasia Pantera Régis Wartelle Sonja Kay Nina Malignier Philippe Van Lerberghe Penka Tsonkova Jaconette Mirck Mercedes Rois Anne Grete Kongsted Claudine Thenail Boki Luske Staffan Berg Marie Gosme Andrea Vityi 《Agroforestry Systems》2018,92(4):829-848
Whilst the benefits of agroforestry are widely recognised in tropical latitudes few studies have assessed how agroforestry is perceived in temperate latitudes. This study evaluates how stakeholders and key actors including farmers, landowners, agricultural advisors, researchers and environmentalists perceive the implementation and expansion of agroforestry in Europe. Meetings were held with 30 stakeholder groups covering different agroforestry systems in 2014 in eleven EU countries (Denmark, France, Germany, Greece, Hungary, Italy, Netherlands, Portugal, Spain, Sweden and the United Kingdom). In total 344 valid responses were received to a questionnaire where stakeholders were asked to rank the positive and negative aspects of implementing agroforestry in their region. Improved biodiversity and wildlife habitats, animal health and welfare, and landscape aesthetics were seen as the main positive aspects of agroforestry. By contrast, increased labour, complexity of work, management costs and administrative burden were seen as the most important negative aspects. Overall, improving the environmental value of agriculture was seen as the main benefit of agroforestry, whilst management and socio-economic issues were seen as the greatest barriers. The great variability in the opportunities and barriers of the systems suggests enhanced adoption of agroforestry across Europe will be most likely to occur with specific initiatives for each type of system. 相似文献
195.
Introduction,IthasbeenwellKnownthatgiantpanda(AjluropodsmelsnoI6uca)isanendangeredandrarespeciesthatdistributesinChinaonly,whosepopulationisdiminishing.GiantpandahasattraCtedtheattentionsofscientistsfromdifferentwalksintheworld.Inoddertorescuethepreciousspecies,Chinaandtheworldhaveputgreatenergyinsuchcontribution.StudiesfromvariousdisciplineshavealsobeenconduCted.Onthereasonsoftheendangeringandmortalityofgiantpandas,differentscientistsfromdifferentdisciplineshavedifferentviewpoints.ZhuJing… 相似文献
196.
197.
Epron D Bahn M Derrien D Lattanzi FA Pumpanen J Gessler A Högberg P Maillard P Dannoura M Gérant D Buchmann N 《Tree physiology》2012,32(6):776-798
Pulse-labelling of trees with stable or radioactive carbon (C) isotopes offers the unique opportunity to trace the fate of labelled CO(2) into the tree and its release to the soil and the atmosphere. Thus, pulse-labelling enables the quantification of C partitioning in forests and the assessment of the role of partitioning in tree growth, resource acquisition and C sequestration. However, this is associated with challenges as regards the choice of a tracer, the methods of tracing labelled C in tree and soil compartments and the quantitative analysis of C dynamics. Based on data from 47 studies, the rate of transfer differs between broadleaved and coniferous species and decreases as temperature and soil water content decrease. Labelled C is rapidly transferred belowground-within a few days or less-and this transfer is slowed down by drought. Half-lives of labelled C in phloem sap (transfer pool) and in mature leaves (source organs) are short, while those of sink organs (growing tissues, seasonal storage) are longer. (13)C measurements in respiratory efflux at high temporal resolution provide the best estimate of the mean residence times of C in respiratory substrate pools, and the best basis for compartmental modelling. Seasonal C dynamics and allocation patterns indicate that sink strength variations are important drivers for C fluxes. We propose a conceptual model for temperate and boreal trees, which considers the use of recently assimilated C versus stored C. We recommend best practices for designing and analysing pulse-labelling experiments, and identify several topics which we consider of prime importance for future research on C allocation in trees: (i) whole-tree C source-sink relations, (ii) C allocation to secondary metabolism, (iii) responses to environmental change, (iv) effects of seasonality versus phenology in and across biomes, and (v) carbon-nitrogen interactions. Substantial progress is expected from emerging technologies, but the largest challenge remains to carry out in situ whole-tree labelling experiments on mature trees to improve our understanding of the environmental and physiological controls on C allocation. 相似文献
198.
Tree plantations are often used to compensate for the destruction and conversion of natural forests in the tropics. An important question is whether these plantations allow for the regeneration of indigenous tree species and are expected to transform into more natural forests in the future. To evaluate the potential of differently managed forest types for seedling recruitment of indigenous tree species we studied structural characteristics as well as tree and seedling communities in stands of natural forest, different types of tree plantations and secondary forest in Kakamega Forest, western Kenya. Forest types differed considerably in structural characteristics and tree composition with stands of natural forest significantly differing from all other forest types in vertical foliage height diversity and number of late-successional tree species. By contrast, total seedling species richness and number did not differ among the forest types. Yet, number of seedlings of late-successional species decreased from natural forest and plantations of a mixture of indigenous tree species towards monocultures and secondary forests while number of seedlings of early-successional species increased in the same order. A joint Principal Component Analysis (PCA) corroborated higher similarity among seedling communities than among tree communities. Our results indicate a convergence of recruiting seedling communities in different forest management types suggesting that tree plantations might buffer forest loss to a certain extent and may have the potential to develop into more natural forest over time. 相似文献
199.
McKenzie F. Johnson Nina Kanderian Christopher C. Shank Haqiq Rahmani David Lawson Peter Smallwood 《Biological conservation》2012,148(1):146-155
Planning for protected area networks is often done on an ad hoc basis, especially in data-poor countries. Afghanistan, a country mired in conflict for the past 30 years, has little of the relevant data to plan a protected area network, and security concerns hinder collection of new data. However, conservation of Afghanistan’s natural resources will be critical to recovery efforts. To assist Afghanistan in planning for its protected area network, we conducted an analysis to identify ecologically important areas for conservation. We overlaid data from ecoregion, floral, and faunal analyses on a grid map of Afghanistan (313 cells each 2500 km2), and used a ranking system to determine those cells containing diverse and/or threatened ecosystems. A color gradation was applied to each cell (white – least diverse to black – most diverse) to produce a map visually depicting ecological diversity across Afghanistan. Those cells with the highest scores were labeled as Priority Zones – defined as areas in which Afghanistan should prioritize conservation activities for protected area designation. Our results formed the basis of the National Protected Area System Plan of Afghanistan, a document setting quantitative protected area targets and outlining a concrete plan of action for the designation of a protected area network. We found the Priority Zone model to be useful in helping Government partners locate areas potentially important for conservation and prioritize activities for protected area designation. This process may be useful for other conflict or post-conflict countries working to establish protected area networks in a data deficient environment. 相似文献
200.
Rosenblat M Volkova N Coleman R Aviram M 《Journal of agricultural and food chemistry》2006,54(5):1928-1935
The effects of a pomegranate byproduct (PBP, which includes the whole pomegranate fruit left after juice preparation) on atherosclerosis development in apolipoprotein E-deficient (E degrees ) mice were studied. Consumption of PBP (17 or 51.5 microg of gallic acid equiv/kg/day) by the mice resulted in a significant reduction in atherosclerotic lesion size by up to 57%. PBP consumption significantly reduced oxidative stress in the mice peritoneal macrophages (MPM): Cellular lipid peroxide content decreased by up to 42%, the reduced glutathione levels increased by up to 53%, and paraoxonase 2 lactonase activity increased by up to 50%, as compared to MPM from E degrees mice that consumed only water. Furthermore, oxidized low-density lipoprotein (Ox-LDL) uptake by the MPM was reduced by up to 19%. Similar results were observed also in vitro. Treatment of J774A.1 macrophages with PBP (10 or 50 micromol/L of total polyphenols) significantly decreased both cellular total peroxide content and Ox-LDL uptake. It was thus concluded that PBP significantly attenuates atherosclerosis development by its antioxidant properties. 相似文献