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排序方式: 共有333条查询结果,搜索用时 15 毫秒
51.
Zineb Choury Tatiana A. Shestakova Hocine Himrane Ramzi Touchan Dalila Kherchouche J. Julio Camarero Jordi Voltas 《European Journal of Forest Research》2017,136(1):139-152
The Algerian Green Barrier, mainly composed of native and artificial Aleppo pine forests, spreads along the pre-Saharan steppes and is threatened by anthropogenic and natural disturbances, including climate change. We hypothesized that the ecophysiological functioning of this conifer has been substantially modified in reaction to recent warming and drought much beyond the expected effect of CO2 fertilization. Our aim was to characterize the long-term performance (1925–2013) of native Aleppo pines thriving at their southernmost distribution. We used tree-ring width (TRW) and carbon isotope discrimination (Δ13C) to characterize basal area increment (BAI) and intrinsic water-use efficiency (WUEi) at three sites. BAI remained stable or slightly increased over time, with mean values ranging between 4.0 and 6.3 cm2 year?1. Conversely, site-Δ13C decreased from ?0.022 to ?0.014‰ year?1 along time, which translated into WUEi increases of ca. 39%. This strong physiological reaction indicated that pines were responding simultaneously to rising CO2 and drier conditions, inducing a progressively tighter stomatal control of water losses. However, WUEi increments were essentially unrelated to BAI and did not affect carbon reserves, which suggests a high resilience to climate change. This finding could be due to shifts in growing season towards earlier months in winter–spring, as suggested by temporal changes in climate factors underlying Δ13C and TRW. Our study highlights the substantial plasticity of Aleppo pine, but this species is unlikely to follow a similar pace of ecophysiological adjustments according to unprecedented low Δ13C records and lack of WUEi stimulation observed from 2000 onwards. 相似文献
52.
Marisela Bernal-González Julio Alberto Solís-Fuentes María-del-Carmen Durán-Domínguez-de-Bazúa 《Water, air, and soil pollution》2017,228(12):456
The process for extracting sugarcane juice (Saccharum officinarum) represents the point of greatest contamination in sugarcane mills. Sodium dithiocarbamate also known as metam-sodium or MS is added to inhibit the growth of microorganisms especially Leuconostoc mesenteroides which is responsible for forming polysaccharides. Metam-sodium, upon decomposition, produces highly toxic byproducts. According to literature, under acidic conditions, MS is hydrolyzed resulting in methylamine (MA), CH3NH2, and carbon disulfide (CS2), and in dilute alkaline solutions, MS produces an oxidation reaction characterized by the formation of elemental sulfur (S) and methyl isothiocyanate (MITC). In this paper, it was studied how MS decomposes to MITC and/or MA considering the effects of the matrix (methanol and water); of temperature (4 and 25 °C); of processing time (0, 1, 2, 3, 4 days); and of pH (4.0, 4.5, 7.0). A second experimental design considering the effects of the matrix (water and sugarcane juice); of temperature (4, 25, 35, 45 °C); of processing time (30, 300 min); and of pH (4.0, 4.5, 7.0) was derived from the results obtained considering MITC and/or MA formation. According to the statistical analysis of these results (p < 0.05), the order of the influential factors was as follows: time > matrix > pH > temperature. Results also indicated that the water matrix at pH = 4.5 and 45 °C had the lowest degradation rate (k), with a value of 8.82 day?1, while for the sugarcane juice matrix at the same pH and temperature conditions was larger, with a k value of 30.07 day?1. These results show that the matrix is also important for the degradation of dithiocarbamate to MITC and to MA. 相似文献
53.
Carbendazim, iprodione, prochloraz-Mn, thiabendazole and thiophanate-methyl were tested in vitro and in vivo for their effect on Mycogone perniciosa, the mycoparasite that causes wet bubble disease of white button mushroom. In vitro experiments showed that prochloraz-Mn (ED50 = 0.006–0.064 μg ml−1) and carbendazim (ED50 = 0.031–0.097 μg ml−1) were the most effective fungicides for inhibiting the mycelial growth of M. perniciosa, while iprodione (ED50 = 1.90–3.80 μg ml−1) was the least effective. The resistance factors calculated for the five fungicides were between 1.4 and 2. The results obtained suggest that there is very little risk that M. perniciosa will develop resistance to the fungicides assayed. The in vivo efficacy of fungicides for control of wet bubble was studied in two mushroom cropping experiments, which were artificially infected with two doses of M. perniciosa, 106 and 107 spores m−2, respectively. There was, in the low dose inoculum experiment, a very high degree of effectiveness (96.5–100.0%) with all the fungicides assayed. However, iprodione performed poorly (20.5–24.4%) compared with the other fungicides (88.7–100.0%) in the high concentration inoculum experiment. The most effective treatments for controlling wet bubble did not improve the biological efficiency of Agaricus bisporus. 相似文献
54.
Maria Barrandeguy Julio Perkins Jorge Mac Donough Aldana Vissani Cecilia Olguin Etienne Thiry 《Journal of Equine Veterinary Science》2010
Equine coital exanthema (ECE) is an acute, venereal disease caused by equid herpesvirus 3 (EHV-3), characterized by the formation of papules, vesicles, pustules, and ulcers on the vaginal and vestibular mucosa as well as on the skin of the penis, prepuce, and perineal region of mares and stallions. The present work describes an outbreak of ECE characterized by typical lesions around the anus and on the perineal skin, discomfort, and anorectal lymphadenopathy, which occurred in a large number of donor and recipient mares at an embryo transfer center in Argentina. We found that the horses' movement pattern, the environmental conditions, and the management procedures could have favored the introduction and/or reactivation from latency and spread of EHV-3. Although this is the first report of an outbreak of ECE in an embryo transfer facility, it reinforces the need to introduce additional hygienic and preventive measures to avoid EHV-3 spread and future ECE outbreaks. 相似文献
55.
56.
Sánchez Ramos O González Pose A Gómez-Puerta S Noda Gomez J Vega Redondo A Águila Benites JC Suárez Amarán L Parra NC Toledo Alonso JR 《Comparative immunology, microbiology and infectious diseases》2011,34(3):259-265
Recombinant adenoviral vectors have emerged as an attractive system for veterinary vaccines development. However, for poultry vaccination a very important criterion for an ideal vaccine is its low cost. The objective of this study was to test the ability of chicken CD154 to enhance the immunogenicity of an adenoviral vector-based vaccine against avian influenza virus in order to reduce the amount of antigen required to induce an effective immune response in avian. Chickens were vaccinated with three different doses of adenoviral vectors encoding either HA (AdHA), or HA fused to extracellular domain chicken's CD154 (AdHACD). Hemagglutination inhibition (HI) assay and relative quantification of IFN-γ showed that the adenoviral vector encoding for the chimeric antigen is able to elicit an improved humoral and cellular immune response, which demonstrated that CD154 can be used as a molecular adjuvant allowing to reduce in about 50-fold the amount of adenoviral vector vaccine required to induce an effective immune response. 相似文献
57.
Marino Garcia-Montijano J. Julio de Lucas María Dolores de San Andrés 《Research in veterinary science》2011,90(2):288-290
The pharmacokinetics properties of marbofloxacin were studied in adult Eurassian Griffon vulture after single-dose intravenous (IV) administration of 2 mg/kg. Drug concentration in plasma was determined by high-performance liquid chromatography and the data obtained were subjected to compartmental and non-compartmental kinetic analysis. Marbofloxacin presented a volume of distribution at steady-state (Vdss) of 1.51 ± 0.22 L and total plasma clearance (Cl) of 0.109 ± 0.023 L/h kg. The permanence of this drug was long in vultures (T1/2λ = 12.51 ± 2.52 h; MRT∞ = 13.54 ± 2.29 h). The optimal dose of marbofloxacin estimated is 2.73 mg/kg per day for the treatment of infections in vultures with MIC90 = 0.2 μg/mL. 相似文献
58.
In order to describe the normal bacterial flora in vaginas of Criollo Limonero cows, 51 healthy multiparous cows, at least
90-day postpartum, were selected. Duplicated swabs (N = 102) were taken from the vaginal fornix of cows to perform aerobic and anaerobic cultures as well as conventional biochemical
tests. Out of 102 swabs, bacterial growth was obtained in 55 (53.9%) while the remaining 47 (46.1%) did not exhibited any
bacterial growth. Of the 55 bacterial growths, 23 (41.8%) were aerobic whereas 32 (58.1%) were anaerobic. Likewise, 29 (52.72%)
of bacterial growths were pure and 26 (47.27%) were mixed. Under both aerobic and anaerobic conditions, Gram positive bacteria
were predominant (81.82% and 73.08%, respectively) over Gram negative bacteria (18.18% and 26.92%, respectively). Isolated
bacteria were Arcanobacterium pyogenes (22.92%), Staphylococcus aureus (15.63%), Staphylococcus coagulase negative (17.71%), Erysipelothrix rhusiopathiae (6.25%), Bacteroides spp. (13.54%), and Peptostreptococcus spp. (7.29%). In conclusion, normal vaginal bacterial flora of Criollo Limonero cows was predominantly Gram positive and included
A. pyogenes, S. aureus, coagulase negative Staphylococcus, E. rhusiopathiae, Bacteroides spp., and Peptostreptococcus spp. In Criollo Limonero cattle, adaptive aspects such as development of humoral and physical mechanisms for defense, and bacterial
adaptation to host deserve research attention. 相似文献
59.
Proaño-Pérez F Benitez-Ortiz W Desmecht D Coral M Ortiz J Ron L Portaels F Rigouts L Linden A 《Preventive veterinary medicine》2011,101(1-2):65-72
Veterinary inspection in slaughterhouses allows for the detection of macroscopic lesions reminiscent of bovine tuberculosis, but the presence of Mycobacterium bovis must be confirmed by laboratory methods. This study aimed at comparing the performances of the standard diagnostic tools used to identify M. bovis in tissue specimens sampled from suspicious animals. During a two years period, 1390 cattle were inspected at the Machachi abattoir in the Mejia canton - Ecuador. A total of 33 animals with granulomatous lesions were detected, representing 2.33% (16/687) and 2.42% (17/703) animals examined in 2007 and 2008, respectively. Ninety-four tissue specimens were sampled and screened for the presence of mycobacteria. Acid-fast bacilli were identified in one third of the suspicious cattle (11/33) and suggestive microscopic lesions in 27.3% (9/33) of the samples examined by direct microscopy and histopathology, respectively. Culturing on Stonebrink medium and 16S-rRNA-based polymerase chain reaction (PCR) yielded 36.4% (12/33) and 27.3% (9/33) of positives, respectively. Compared to culture, other diagnostic procedures displayed a lower sensitivity, with 56.5% for PCR, and 43.5% for direct microscopy and histopathology; however, the specificity was higher (94.4% for PCR and microscopy, and 97.2% for histopathology). We conclude that reliable post-mortem laboratory testing either requires the combination of a set of available diagnostic tools or necessitates the development of improved new-generation tools with better sensitivity and specificity characteristics. 相似文献
60.
Robles Jimenez Lizbeth E. Ruiz Perez Jose A. Nicolas Di Lorenzo Chay Canul Alfonso J. Ramirez-Rivera Julio Cesar Villegas-Estrada Daniela Vargas-Bello-Pérez Einar Gonzalez-Ronquillo Manuel 《Tropical animal health and production》2020,52(3):1257-1267
Tropical Animal Health and Production - Currently for the reduction of methane (CH4) emissions are using fodder rich in condensed tannins, however, not yet known exactly how they act in the rumen... 相似文献