Adenovirus infection in ovine kidney and liver     

JW FINNIE  JG SWIFT 《Australian veterinary journal》1991,68(5):184-184

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Lack of effect of combining different stressors on innate immune responses of seabream (Sparus aurata L.)   总被引：1，自引：0，他引：1  

Ortuño J  Esteban MA  Meseguer J 《Veterinary immunology and immunopathology》2002,84(1-2):17-27

A complex stressful event, which commonly occurs in modern aquacultural practices, was broken down into factors that were analysed both individually and jointly to assess their effect on two stress indicators (blood glucose and serum cortisol levels) and two activities of the innate immune response (serum complement and head-kidney leukocyte respiratory burst). For this, gilthead seabream (Sparus aurata L.) specimens were exposed to the following stressors: physical disturbance, crowding, anaesthesia with 2-phenoxyethanol and air exposure. At 0, 1, 2, 3 and 4 days post-stress, blood and serum samples were collected to measure glucose concentration and cortisol and complement levels, respectively. Head-kidney leukocytes were isolated and assayed to evaluate respiratory burst activity. The results show that physical disturbance, crowding and anaesthesia produced an occasional increase in glucose and cortisol concentrations. Crowding and anaesthesia induced a depression in complement activity, while hypoxia by air exposure caused a reduction in the respiratory burst. When all factors were jointly applied both humoral and cellular defences were compromised and cortisol values remained high throughout the experimental period. Any long-term effects of this abnormal serum cortisol levels on the immune system remain unknown.  相似文献   

Effect of setting a maximum milking time,from peak lactation,on production,milking time and udder health     

JG Jago  JE McGowan  JH Williamson 《New Zealand veterinary journal》2013,61(5):246-252

Abstract

AIM: To examine the effect of setting a maximum milking time, from peak lactation until drying-off, on production, duration of milking, and udder health of dairy cows.

METHODS: Forty cows were assigned in twin-pairs to be either milked until cups were removed at a milk flow-rate threshold of 0.35 kg/minute (Control), or until cups were removed at a milk flow-rate threshold of 0.35 kg/minute, or maximum time, whichever came first (MaxT). The maximum time was set by determining the milking time of the 70th percentile cow when ranked from fastest to slowest, irrespective of yield. The milking routine was typical of that practised on dairy farms in New Zealand, and involved no pre-milking preparation. The study began at peak lactation (68 (SD 7) days in milk; DIM) and continued for 26 weeks. Duration of milking and milk yield were measured for each milking. Composition of milk was determined from weekly herd tests, and milk quality from fortnightly somatic cell counts (SCC). Completeness of milking and teat condition were assessed during the study. The bacterial status of quarter milk samples was determined at the beginning and end of the study, and all treated cases of clinical mastitis recorded. ANOVA was used to examine the effect of treatment group on variables of interest.

RESULTS: Total milk, fat and protein yields during the study period did not differ between treatments. On average, 30.3% of the morning and 27.6% of the afternoon milkings of MaxT cows reached the maximum time at which cups were removed, and were therefore shortened. While the average milking time of the slowest-milking cow was longer for the Control compared with MaxT group in Weeks 1–18, the average milking time did not differ between treatments. There was no difference in overall SCC, and the incidence of clinical mastitis, or the percentage of infected quarters at drying-off, was similar for the MaxT and Control cows.

CONCLUSION: The results show that setting a maximum milking time can reduce the milking time of slower-milking cows in a herd without compromising overall herd production and udder health.

CLINICAL RELEVANCE: Although the numbers of cows in the study were small there was no evidence of a major increase in SCC, or subclinical or clinical mastitis when a maximum milking time was set for slower-milking cows.  相似文献   

Arsenic and Heavy Metal Uptake and Accumulation in Native Plant Species from Soils Polluted by Mining Activities   总被引：1，自引：0，他引：1  

Sara García-Salgado  David García-Casillas  Ma. Angeles Quijano-Nieto  Ma. Milagros Bonilla-Simón 《Water, air, and soil pollution》2012,223(2):559-572

Arsenic and heavy metal (specifically Cd, Cr, Cu, Ni, Pb, and Zn) uptake, translocation, and accumulation in ten native plant species spontaneously growing in soils polluted by mining activities were studied, with a focus on future phytoremediation work in polluted soils. Plant and soil samples were collected in the vicinity of the Mónica mine (NW Madrid, Spain). Soil analysis showed the ability of native plants for growing in soils with high concentration levels of Cd, Cu, Pb, Zn, and especially As. From these elements, the highest percentage of extractable elements was found for Cd and the lowest for Pb. A highly significant correlation was observed between total and extractable element concentrations in soils, except for Cu, indicating that total concentration is the most relevant factor for element mobility in these soils. Extractable elements in soils were better correlated with concentrations in plants than total elements in soils; thus, extraction methods applied are suitable to estimate the element phytoavailable fraction in soils, which depends on the plant species and not only on the element mobility in soils. High element concentrations were found in the aboveground parts of Corrigiola telephiifolia (As and Pb), Jasione montana (Cd and Zn), and Digitalis thapsi (As, Cd, Cu, Pb and Zn). However, considering the translocation and accumulation factors, together with the concentration levels found in roots and aboveground parts, only C. telephiifolia could be considered a Pb accumulator and an As hyperaccumulator plant, which could be used for future phytoremediation work in soils polluted with As.  相似文献   

Polyphenol oxidase and its relationship with oleuropein concentration in fruits and leaves of olive (Olea europaea) cv. 'Picual' trees during fruit ripening     

Ortega-García F  Blanco S  Peinado MA  Peragón J 《Tree physiology》2008,28(1):45-54

Oleuropein, the main phenolic compound of olive fruit, has important antioxidant properties that are responsible for some of the nutritional properties of fruits and the defence mechanism of leaves. Polyphenol oxidase (PPO) activity changes during fruit ripening in many plants. We studied the kinetics and molecular properties of PPO in fruits and leaves of olive (Olea europaea L.) cv. 'Picual' trees and the relationship between PPO and oleuropein concentration during fruit ripening. Polyphenol oxidase showed hyperbolic kinetics in fruits and leaves. Significant increases in PPO specific activity, V(max), K(m )and catalytic efficiency occurred during fruit ripening. Based on SDS-PAGE under partially denaturing conditions and in-gel staining with DL-3,4-dihydroxyphenylalanine, PPO activity was found in one major protein of 55 and 50 kDA in fruits and leaves, respectively. During the last stages of fruit maturation, a second 36 kDa protein was observed in fruits but not in leaves, indicating that this protein could serve as a marker of the final phase of fruit maturation. Under fully denaturing conditions, only one 27.7 kDa immunoreactive band was detected in fruits. Both the amount of PPO activity and the amount of PPO protein increased significantly during fruit maturation. Immunohistochemical studies indicated that PPO is located in the epidermis, parenchyma and companion vascular cells of leaves as well as in the epidermis of fruit. During fruit maturation, oleuropein concentration measured by HPLC significantly decreased in fruits and increased in leaves.  相似文献   

Citrus rootstock responses to water stress   总被引：1，自引：0，他引：1  

Juan Rodríguez-Gamir  Eduardo Primo-MilloJuan B. Forner  M. Angeles Forner-Giner 《Scientia Horticulturae》2010

Tolerance to drought-stress (DS) of the citrus rootstock Forner–Alcaide no. 5 (FA-5) was tested and compared with that of its parents, Cleopatra mandarin (CM) and Poncirus trifoliata (PT). Nine-month-old seedlings of CM, PT and FA-5 and 15-month-old grafted trees of ‘Valencia’ orange scions on these three rootstocks were cultivated in sand under glasshouse conditions and irrigated with a nutrient solution. Plants were drought-stressed by withholding irrigation until leaves were fully wilted. Survival time of both seedlings and grafted trees under DS was linked to the water extraction rate from the soil, which depended mainly on leaf biomass and on transpiration rate. Seedling responses to DS affecting leaf water relationships and gas exchange parameters varied among genotypes. FA-5 seedlings survived longer than the other seedlings, maintaining the highest levels of water potential, stomatal conductance, transpiration rate and net CO₂ assimilation towards the end of the experiment, when water stress was most severe. Thus, FA-5 was more resistant to DS than its parents (CM and PT). Moreover, rootstock affected the performance of grafted trees under water stress conditions. The higher drought tolerance induced by FA-5 rootstock could be related to the greater osmotic adjustment (OA), which was reflected by smaller reductions in leaf relative water content (RWC) and in higher turgor potentials and leaf gas exchange than the other rootstocks.  相似文献   

Alternative Washing Protocols for Releasing Metals Deposited on Leaf Surfaces     

Mildred Yanisa Barrios Arlanzón  Ma. del Carmen Angeles González-Chávez  Ariadna S. Sánchez-López  Luis Manuel Carrillo López 《Communications in Soil Science and Plant Analysis》2019,50(9):1148-1160

This study was performed to test suitable washing protocols for removing potentially toxic elements (PTE) deposited on leaves of plants from metal mine tailings. Two experiments were performed; with five and four treatments, respectively. In both cases, a non-washed treatment was included too. All the washing protocols significantly (p ≤ 0.05) reduced PTE concentrations in leaves of Dalea bicolor and Aliona choisyi. A. choisyi leaves had higher PTE concentrations than those of D. bicolor. From the first experiment, the concentration of lead (Pb, mg/kg) in unwashed leaves of A. choisyi was 715; while in the washed leaves treatments, it was in the range of 142–308. For cadmium (Cd) it was 23 vs the range of 7–18, for copper (Cu) it was 210 vs the range of 35–115 and for zinc (Zn) it was 3398 vs the range of 777–380, respectively. The single use of water does not remove all PTE deposited in leaves and conduces to overestimation of PTE leaf concentrations. Washing effectiveness varied according to PTE, plant species and treatments, but not the time of washing. Cd was the least removed from leaf surface (up to 69%), while Cu and Zn were the most removed from D. bicolor leaves (98% to 100%). Treatments involving the use of diluted HCl and sodium hexametaphosphate had the highest removal of Pb and Zn, while diluted HCl was effective to release Cd and Cu from leaves. The conscious washing procedure before chemical analysis leaf PTE concentration might significantly modify PTE concentration and the perception of plant accumulation.  相似文献   

Hydrogen radicals, nitrogen radicals, and the production of O3 in the upper troposphere     

PO Wennberg  TF Hanisco  L Jaegle  DJ Jacob  EJ Hintsa  EJ Lanzendorf  JG Anderson  R Gao  ER Keim  SG Donnelly  LAD Negro  DW Fahey  SA McKeen  RJ Salawitch  CR Webster  RD May  RL Herman  MH Proffitt  JJ Margitan  EL Atlas  SM Schauffler  F Flocke  CT McElroy  TP Bui 《Science (New York, N.Y.)》1998,279(5347):49-53

The concentrations of the hydrogen radicals OH and HO2 in the middle and upper troposphere were measured simultaneously with those of NO, O3, CO, H2O, CH4, non-methane hydrocarbons, and with the ultraviolet and visible radiation field. The data allow a direct examination of the processes that produce O3 in this region of the atmosphere. Comparison of the measured concentrations of OH and HO2 with calculations based on their production from water vapor, ozone, and methane demonstrate that these sources are insufficient to explain the observed radical concentrations in the upper troposphere. The photolysis of carbonyl and peroxide compounds transported to this region from the lower troposphere may provide the source of HOx required to sustain the measured abundances of these radical species. The mechanism by which NO affects the production of O3 is also illustrated by the measurements. In the upper tropospheric air masses sampled, the production rate for ozone (determined from the measured concentrations of HO2 and NO) is calculated to be about 1 part per billion by volume each day. This production rate is faster than previously thought and implies that anthropogenic activities that add NO to the upper troposphere, such as biomass burning and aviation, will lead to production of more O3 than expected.  相似文献   

In situ observations of a high-pressure phase of H2O Ice     

IM Chou  JG Blank  AF Goncharov  H Mao  RJ Hemley 《Science (New York, N.Y.)》1998,281(5378):809-812

A previously unknown solid phase of H2O has been identified by its peculiar growth patterns, distinct pressure-temperature melting relations, and vibrational Raman spectra. Morphologies of ice crystals and their pressure-temperature melting relations were directly observed in a hydrothermal diamond-anvil cell for H2O bulk densities between 1203 and 1257 kilograms per cubic meter at temperatures between -10 degrees and 50 degreesC. Under these conditions, four different ice forms were observed to melt: two stable phases, ice V and ice VI, and two metastable phases, ice IV and the new ice phase. The Raman spectra and crystal morphology are consistent with a disordered anisotropic structure with some similarities to ice VI.  相似文献   

Principles for Sustainable Governance of the Oceans   总被引：1，自引：0，他引：1  

R Costanza  F Andrade  P Antunes  den Belt M  D Boersma  DF Boesch  F Catarino  S Hanna  K Limburg  B Low  M Molitor  JG Pereira  S Rayner  R Santos  J Wilson  M Young 《Science (New York, N.Y.)》1998,281(5374):198-199

Pressures being exerted on the ocean ecosystems through overfishing, pollution, and environmental and climate change are increasing. Six core principles are proposed to guide governance and use of ocean resources and to promote sustainability. Examples of governance structures that embody these principles are given.  相似文献