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排序方式: 共有369条查询结果,搜索用时 15 毫秒
361.
Geórgia Camargo Góss Fabricio Desconsi Mozzaquatro Raphaela Vanhove Lilian Pinto Camargo Gabriela Döwich Pradella Carla Teixeira Leite Etiele Maldonado Gomes Ana Luisa Moreira Carneiro Gabriel Feix Heckler Claudia Acosta Duarte 《Anatomia, histologia, embryologia》2021,50(3):493-499
The physiological measurements of collateral ligaments of distal interphalangeal joint (CL-DIPJ) differ in the literature. The factors that influence these differences are not well described. The aims of this study are to compare CL-DIPJ sizes in equines with different withers height, as well as to correlate body weight and hoof size to the size of these ligaments. In total, 52 horses were used in the study. They were divided into two groups according to wither height: Group 1 (G1) - 21 animals with up to 147 cm - and group 2 (G2) - 21 animals with greater than 148 cm. CL-DIPJ was ultrasonographically measured in order to find the mean of dorso-palmar (DPD) and latero-medial (LMD) diameters and the cross-sectional area (CSA). Hoof width and length were measured, and the results were used to calculate the hoof surface area. Withers height and body weight were also measured. Groups were statistically compared by Student's t test and Pearson's correlation application to each group. Groups were different in body size, HS and CL-DIPJ size when p < .05, except for the LMD of the medial collateral ligament of left thoracic limb. Withers height and body weight did not show significant correlations to CL-DIPJ size in G1, but they had little influence on the size of CL-DIPJ on G2. No correlation between the hoof size and the CL-DIPJ was noted in any of the two groups. In conclusion, the CL-DIPJ were larger in taller horses and their sizes were correlated to their height and weight, but they were not correlated to hoof size. 相似文献
362.
Gabriela Valeria Villavicencio Valdez Eric N. Hansen John Bliss 《Small-Scale Forestry》2012,11(3):339-363
In most developing countries where local community ownership is common, successful forest conservation initiatives must be adapted to engage and train rural communities. Decentralization of decision-making and stewardship by the State is required to maintain forests as a common good with extended benefits to society. Despite a tendency to operate in isolation, three Oaxacan community forest enterprises (CFEs), Textitlán, Ixtlán and Pueblos Mancomunados, have vertically integrated from forest management to retailing furniture through a company: TIP Muebles. This exploratory study aims to provide insight and outline the factors impacting the ability of CFEs to succeed in the marketplace given the fact that each deals with the same regulation structure of public forest policy. The results of this research suggest that the main challenges are related to human capital, regulatory challenges and centralized forest policy for forest product production, the taxation system for timber production, and endogenous factors such as the forest quality and the decisions based on tradition rather than efficiency. In this context, the integration of chains of production is a fact in only a few cases and financial success continues to be slow. The studied CFEs are resilient and slightly surpassing the profitability threshold despite the challenges identified. Adaptation of their decision-making structure allows them to face the changing dynamics of the market. More democratic approaches to decentralization of Mexican forest policy, trust development between social and private enterprises, and an improvement in internal CFEs systems could offer opportunities for improved competitiveness for CFEs. CFE strategies need to be understood as part of a complex rural livelihood where diversification of income generating activities often conflicts with competitive and specialized production. 相似文献
363.
Mergers play an important role in galaxy evolution and are key to understanding the correlation between central-black hole mass and host-galaxy properties. We used the new technology of adaptive optics at the Keck II telescope to observe NGC 6240, a merger between two disk galaxies. Our high-resolution near-infrared images, combined with radio and x-ray positions, revealed the location and environment of two central supermassive black holes. Each is at the center of a rotating stellar disk, surrounded by a cloud of young star clusters. The brightest of these young clusters lie in the plane of each disk, but surprisingly are seen only on the disks' receding side. 相似文献
364.
Oprea GE Kröber S McWhorter ML Rossoll W Müller S Krawczak M Bassell GJ Beattie CE Wirth B 《Science (New York, N.Y.)》2008,320(5875):524-527
Homozygous deletion of the survival motor neuron 1 gene (SMN1) causes spinal muscular atrophy (SMA), the most frequent genetic cause of early childhood lethality. In rare instances, however, individuals are asymptomatic despite carrying the same SMN1 mutations as their affected siblings, thereby suggesting the influence of modifier genes. We discovered that unaffected SMN1-deleted females exhibit significantly higher expression of plastin 3 (PLS3) than their SMA-affected counterparts. We demonstrated that PLS3 is important for axonogenesis through increasing the F-actin level. Overexpression of PLS3 rescued the axon length and outgrowth defects associated with SMN down-regulation in motor neurons of SMA mouse embryos and in zebrafish. Our study suggests that defects in axonogenesis are the major cause of SMA, thereby opening new therapeutic options for SMA and similar neuromuscular diseases. 相似文献
365.
Elisa Chan‐Vivas Magaa‐Gallegos Edn Carlos Maldonado Karla Escalante Gabriela Gaxiola Gerard Cuzon 《Journal of the World Aquaculture Society》2019,50(2):460-468
In a 45‐d experiment, Litopenaeus vannamei was cultured in two treatments, biofloc technology or clear water recirculating aquaculture system, to evaluate the effect on growth and survival, energy balance, and texture of the marketable product. The experimental design consisted of 40 plastic tanks of 54 L (20 tanks per treatment), with a density of 140 organisms/m3 in each culture system. The final body weight, daily growth coefficient, and survival were significantly higher (P < 0.05) in biofloc technology (12.40 g, 5.0%g/d, and 87.1%, respectively) than in the clear water system (7.0 g, 1.4%g/d, and 74.2%). The retained energy and energy content of exuviae were significantly higher for shrimp in the biofloc technology (448.5 ± 36.4 and 22.4 ± 1.8 J/shrimp/d, respectively) than in clear water (246.3 ± 40.9 and 12.3 ± 2.0 J/shrimp/d, respectively). Routine metabolism was significantly higher for the clear water treatment (411.4 ± 123.8 J/shrimp/d). Shear force was higher in the biofloc technology, indicating greater muscle firmness; this matched the gel electrophoresis patterns of the proteins extracted from the muscle tissues. This suggests that biofloc technology could be used not only to improve growth and survival in L. vannamei but also to enhance the final product quality and acceptability in the market. 相似文献
366.
367.
Nelly Tremblay Marcelo García-Guerrero Fernando Díaz Claudia Caamal-Monsreal Gabriela Rodríguez-Fuentes Kurt Paschke Paulina Gebauer Carlos Rosas 《Aquaculture Research》2022,53(1):63-74
The present study was designed to assess the performance of the freshwater prawn Macrobrachium tenellum in optimal and sub-optimal dissolved oxygen conditions, considering increasing environmental pressures. Thermal tolerance and thermal metabolic scope (TMS) with related integrated biomarker response (IBR) were measured in prawns exposed to normoxia (80% air saturation), mild (40% air saturation) and severe hypoxia (25% air saturation) at three exposure time points (10, 20 and 30 days). Effects of hypoxia on thermal tolerance were not detectable over time; they were perhaps masked by hyperventilation, or by an increase or diversion of haemolymph processes. After 30 days, TMS was 11% higher in mild hypoxia compared with normoxia, while it was 64% lower in severe hypoxia, indicating the loss of aerobic metabolism capacity during the latter. Mild-hypoxia prawns maintained a high IBR over time, supported by antioxidant enzyme activities (mainly superoxide dismutase), which helped avoid the serious oxidative damage (proteins and lipids) seen in severe hypoxia animals, as well as lower acetylcholinesterase activity that indicated failure of communication between the nervous and locomotor systems. Our results documented a high tolerance by M. tenellum to mild-hypoxia events, which should be further tested under seasonal and extreme habitat/tank temperatures. 相似文献
368.
Crop contamination by selected trace elements 总被引:2,自引:0,他引:2
Gabriela?Baran?íkováEmail author Mikulà??Madams Ondrej?Rybàr 《Journal of Soils and Sediments》2004,4(1):37-42
Goal and Background The regulatory limit for the allowable concentration of heavy metals (HM) in agricultural soils should be based both on HM
status and on soil parameters that influence HM mobility. In this paper, a soil categorization scheme is proposed which is
based on the main factors that influence HM mobility in soils. The scheme also makes use of the existing regulatory limits
for total concentrations of trace elements in Slovak soils but additionally takes into account the potential ability of the
soils to mobilize trace elements. A map of the Slovak Republic showing the soil categorization using this scheme is presented.
Methods Besides total soil content of Cd, Pb, Cr, Hg, As, Cu, Zn, Ni, soil parameters with dominant influence on HM mobility are included
in the scheme pH, organic matter content, quality of humus represented by spectral parameter Q4
6 and content of fraction f < 0.01 mm. Point rating approach was used for categorization. Database of localized soil data from
3556 locations was used for creation of map in GIS environment.
Results Based on the point scoring method described herein, soils are ranked from a (the least risk of crop contamination) to d (medium
risk). Categories e and f are reserved for soils where the risk exceeds the allowable regulatory limits. For each of the six
categories, the most suitable usage of agricultural land is recommended. The Slovak map presented shows that the main factor
that affect the spatial distribution of each soil category is soil parent material which governs the existing total HM content
and the predisposition for certain soil types to have high HM mobility. Agricultural usage of land in Slovakia is in most
cases limited by exceedences of Cr and Ni, originating from widespread flysch rock parent material.
Conclusions Application to regional geochemical data shows that, for more than half of Slovak agricultural land, risk of crop contamination
is low. For the rest of the area, planting should consider sensitivity of crops to HM uptake.
Recommendation and Outlook Evaluation of suitable agricultural usage based on HM contamination risk, should include not only the total HM content but
also the potential for HM mobility, which can increase the risk of plant contamination. Where HM mobility data are not available,
soil parameter data that influence HM mobility can be used to predict the potential HM soil contamination hazard. 相似文献
369.
Poplar growth and wood production on a grassland irrigated for decades with potato starch wastewater
Gabriela Lorenc-Plucińska Marta Walentynowicz Andrzej Lewandowski 《Agroforestry Systems》2017,91(2):307-324
Irrigation of grasslands with potato starch wastewater causes changes in soil quality parameters, often resulting in decreased crop yields and sometimes causing animal diseases. Reduced agricultural income leads to designation of such grasslands for afforestation aimed at production of bioenergy crops and improvement of soil quality. In this study, Populus alba L. and seven different poplar clones were planted in 2009 on the grassland irrigated in 1973–2008 with potato starch wastewater and in non-irrigated, experimental forest. The survival, growth and wood production potential of planted poplars after 2–3 growing seasons were analyzed. Morphophysiological parameters of leaves, nutrients in leaves and fine roots, sugars in fine roots, leaf rust resistance, frost hardiness and their effects on growth were also determined. Stem diameter and stem volume index of poplars growing on the grassland were higher than in the experimental forest. Only Populus deltoides Bartr. × P. maximowiczii Henry clone ‘Eridano’ (in short ERI) had a survival rate of 100 % and the highest values of stem diameter (77 mm) and stem volume index (0.034 m3) in comparison with other poplars in both sites after 3 growing seasons. Clone ERI was also characterized by a high leaf rust resistance and frost hardiness. The results suggest that clone ERI is suitable as a bioenergy crop on grasslands irrigated with potato starch wastewater. Afforestation of the grassland improved the fertility of the soil by increasing concentrations of soil organic matter and availability of mineral nutrients (N, P, K, S and Fe). 相似文献