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101.
OBJECTIVE: To identify patterns and correlations of gross, histologic, and gene expression characteristics of articular cartilage from horses with osteoarthritis. ANIMALS: 10 clinically normal horses and 11 horses with osteoarthritis of the metacarpal condyles. PROCEDURES: Metacarpophalangeal joints were opened and digitally photographed, and gross lesions were scored and quantified. Representative cartilage specimens were stained for histologic scoring. Total RNA from dorsal and palmar articular surfaces was processed on an equine gene expression microarray. RESULTS: Histologic scores were greater in both regions of osteoarthritic joints, compared with corresponding regions in control joints. Cartilage from the palmar aspect of diseased joints had the highest histologic scores of osteoarthritic sites or of either region in control joints. A different set of genes for dorsal and palmar osteoarthritis was identified for high and low gene expression. Articular cartilage from the dorsal region had surface fraying and greater expression of genes coding for collagen matrix components and proteins with anti-apoptotic function, compared with control specimens. Articular cartilage from the palmar region had greater fraying, deep fissures, and less expression of genes coding for glycosaminoglycan matrix formation and proteins with anti-apoptotic function, compared with cartilage from disease-free joints and the dorsal aspect of affected joints. CONCLUSIONS AND CLINICAL RELEVANCE: Metacarpal condyles of horses with naturally occurring osteoarthritis had an identifiable and regional gene expression signature with typical morphologic features.  相似文献   
102.
Due to increases in tree density and hazardous fuel loading in Sierra Nevadan forests, land management is focusing on fuel reduction treatments to moderate the risk of catastrophic fires. Fuel treatments involving mechanical and prescribed fire methods can reduce surface as well as canopy fuel loads. Mastication is a mechanical method which shreds smaller trees and brush onto the surface fuel layer. Little data exist quantifying masticated fuel beds. Despite the paucity of data on masticated fuels, land managers desire fuel loading, potential fire behavior and fire effects such as tree mortality information for masticated areas. In this study we measured fuel characteristics before and after mastication and mastication plus prescribed burn treatments in a 25-year old ponderosa pine (Pinus ponderosa C. Lawson) plantation. In addition to surface fuel characteristics and tree data collection, bulk density samples were gathered for masticated material. Regressions were created predicting masticated fuel loading from masticated fuel bed depth. Total masticated fuel load prior to fire treatment ranged from 25.9 to 42.9 Mg ha−1, and the bulk density of masticated fuel was 125 kg m−3. Mastication treatment alone showed increases in most surface fuel loadings and decreases in canopy fuel loads. Masticated treatment in conjunction with prescribed burning reduced both surface and canopy fuel loads. Detailed information on fuel structure in masticated areas will allow for better predictions of fire behavior and fire effects for fire in masticated fuel types. Understanding potential fire behavior and fire effects associated with masticated fuels will allow managers to make decisions on the possibility of mastication to create fuel breaks or enhance forest health.  相似文献   
103.
Tropical deforestation and habitat fragmentation in areas around conservation areas have been an important element for discussion in the conservation and policy-making community. In this paper, we evaluate land cover change processes around one of the most important tropical dry forest reserves in the Americas: the Chamela-Cuixmala Biosphere Reserve, Mexico. The analysis is conducted at three scales: regional scale (coast of the State of Jalisco), proximity to the reserve (via a 30-km buffer zone analysis), and inside the Biosphere Reserve. The proximity analysis is complemented by a unique data set that represents the extent and boundaries of Ejidos (local land management units) in the region. Results indicate that areas surrounding the reserve have low deforestation, with Ejidos and buffer areas having more forest cover as they get closer to the reserve. The nature of this important phenomenon is discussed in the context of the socio-economic conditions of the local communities. Our work suggests that the creation of a network of “Ejidos’ Conservation Areas”, in the context of an approach that will recognize payments for environmental services provided to local communities, could contribute to the conservation and maintenance of the rich biodiversity in a region that has one of the highest levels of endemism in the world.  相似文献   
104.
Understanding tropical forest succession is critical for the development of tropical forest conservation strategies worldwide, given that tropical secondary forests can be considered the forests of the future. Tropical dry forests (TDF) are among the most threatened tropical ecosystems, there are more secondary forests and forest restoration efforts that require a better understanding of successional processes. The main goal of this synthesis for this special issue on the ecology and management of tropical dry forests in the Americas is to present a summarized review of the current knowledge of the ecology and management implications associated to TDF succession. We explore specific issues associated to tropical dry forest succession with emphasis on the use of chronosequences, plant diversity and composition, plant phenology and remote sensing, pollination, and animal–plant interactions; all under the integrating umbrella of ecosystem succession. We also emphasize the need to conduct socio-ecological research to understand changes in land-use history and its effects on succession and forest regeneration of TDF. We close this paper with some thoughts and ideas associated with the strong need for an integrating dimension not considered until today: the role of cyberinfrastructure and eco-informatics as a tool to support sound conservation, management and understanding of TDF in the Americas.  相似文献   
105.
106.
The well known metabolic functions of L-arginine have been recently increased with the discovery of its role as the substrate for the synthesis of nitric oxide (NO), which has emerged as an endogenous signaling molecule with potential therapeutic implications for cardiovascular disease. Steady-state levels of NO are derived in part from dietary sources. It has been reported that supplementation of L-arginine reduces atherosclerosis in rabbits and reduces the arterial pressure in hypertensive rats. Therefore, we investigated the effect of L-arginine supplementation using a group of induced hypercholesterolemic rats and a group of spontaneously hypertensive rats; the infarcted area in cardiac tissue of both groups was measured during the response to myocardial infarction in the ischemia-reperfusion model. Hypercholesterolemic rats supplemented with 170 mg kg−1 of L-arginine showed a significant (P ≤ 0.05) reduction in total cholesterol (25.2%) and LDL (27.8%). Spontaneously hypertensive rats supplemented with L-arginine presented a significant reduction (20.3%) in mean blood pressure (P ≤ 0.05). The index infarcted area / total heart area, in both: hypercholesterolemic and hypertensive rats supplemented with L-arginine, showed a significant 36% and 29% of cardio protection (P ≤ 0.05) effect, respectively. Dietary supplementation with L-arginine may represent a potentially novel nutritional strategy for the treatment of cardiovascular disease.  相似文献   
107.
For development to proceed normally, animal eggs must undergo a maturation process that ultimately depends on phosphorylations of key regulatory proteins. To analyze the kinases that mediate these phosphorylations, eggs of marine nemertean worms have been treated with pharmacological modulators of intracellular signaling pathways and subsequently probed with immunoblots employing phospho-specific antibodies. This article both reviews such analyses and compares them with those conducted on mammals, while focusing on how egg maturation in nemerteans is affected by signaling pathways involving cAMP, mitogen-activated protein kinases, Src-family kinases, protein kinase C isotypes, AMP-activated kinase, and the Cdc2 kinase of maturation-promoting factor.  相似文献   
108.
The open reading frame 2 (ORF2) of human astrovirus (HAstV) encodes the structural VP26 protein that seems to be the main antigenic viral protein. However, its functional role remains unclear. Bioinformatic predictions revealed that VP29 and VP26 proteins could be involved in virus-cell interaction. In this study, we describe for the first time the cloning and expression in Escherichia coli (E. coli) of a recombinant VP26 (rVP26) protein and a VP26 C-terminal truncated form (VP26 Delta C), followed by purification by NTA-Ni(2+) agarose affinity chromatography. Protein expression and purification were evaluated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot (WB). Then, the purified proteins were evaluated for antigenic properties in enzyme linked immunosorbent assay (ELISA) using a polyclonal antibody (PAb) and a neutralizing monoclonal antibody (nMAb) named PL2, both of them directed to HAstV. The results presented herein indicate that the C-terminal end of the VP26 protein is essential to maintain the neutralizing epitope recognized by nMAb PL2 and that the N-terminus of VP26 protein may contain antigenic lineal-epitopes recognized by PAb. Thus, these recombinant proteins can be ideal tools for further antigenic, biochemical, structural and functional VP26 protein characterization, in order to evaluate its potential role in immunodiagnosis and vaccine studies.  相似文献   
109.
Tuberculosis in goats (caused by Mycobacterium caprae and M. bovis) has become a significant concern in recent years because of its high prevalence in certain caprine herds in Spain and other European countries, and also due to the potential transmission to other animals and human beings. In the present study, a transthoracic model of tuberculosis infection was performed on goats. Animals were selected based on the serological response used to detect paratuberculosis in goats (negative and positive results). The kinetics of the immune response was evaluated using the interferon-γ (IFN-γ) assay, skin tests and serology of paratuberculosis during nine months post-challenge. At the end of the study the animals were necropsied, tuberculosis-lesions were scored and culture (M. caprae and M. avium subsp. paratuberculosis) was performed to determine the true infection status. Animals were positive to the IFN-γ assay 15 days post-challenge and the values were fluctuating throughout the study. A varied performance of the assay was observed between tuberculosis and tuberculosis-paratuberculosis mixed infection regarding both the number of positive results and the OD values obtained after stimulation with bovine and avian PPDs. Furthermore, the single intradermal comparative cervical tuberculin test did not detect all M. caprae-infected animals. At necropsy, a positive correlation between pathology score and bovine PPD specific IFN-γ response was found.  相似文献   
110.
1. Whale shark, the world's largest fish, is believed to be particularly vulnerable owing to its biological characteristics (slow growth, late maturation, great longevity) and is listed as Vulnerable by IUCN and included in Appendix II of CITES. 2. Whale sharks are occasionally encircled in tropical tuna purse‐seine nets, throughout this global fishery. Although apparent immediate survival rates following encirclement and release have recently been assessed through scientific onboard observer programmes, a more rigorous methodology is still required for studying post‐released survival. 3. This work provides a method for applying pop‐up satellite tags and reports an enhanced release procedure for whale sharks. The first assessment of survival after release from purse‐seine nets involved six whale sharks tagged between May and September 2014 in the eastern tropical Atlantic Ocean. Five tags transmitted data: three popped up as programmed (after 30 days), while two surfaced prematurely (one after 21 and the other after 71 days (programmed to pop off after 30 and 90 days, respectively)) but showed no sign of unusual behaviour. 4. Overall, whale sharks survived at least 21 days (one at least 71 days) after release from purse‐seine nets. These observations based on five large individuals (total length > 8 m), suggest that whale sharks have a good chance of survival when released with the proposed method. 5. Additional tagging in this and other oceans, especially of juveniles which may be more sensitive to encirclement and release operations, is essential to further assess whale shark post‐release survival rates in tuna purse‐seine fisheries. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   
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