Winter variation in xylem sap pH of walnut trees: involvement of plasma membrane H+-ATPase of vessel-associated cells     

Alves G  Ameglio T  Guilliot A  Fleurat-Lessard P  Lacointe A  Sakr S  Petel G  Julien JL 《Tree physiology》2004,24(1):99-105

We studied seasonal variation in xylem sap pH of Juglans regia L. Our main objectives were to (1) test the effect of temperature on seasonal changes in xylem sap pH and (2) study the involvement of plasma membrane H+-ATPase of vessel-associated cells in the control of sap pH. For this purpose, orchard-grown trees were compared with trees grown in a heated (> or = 15 degrees C) greenhouse. During autumn, sap pH was not directly influenced by temperature. A seasonal change in H+-ATPase activity resulting from seasonal variation in the amount of protein was measured in orchard-grown trees, whereas no significant seasonal changes were recorded in greenhouse-grown trees. Our data suggest that H+-ATPase does not regulate xylem sap pH directly by donating protons to the xylem, but by facilitating secondary active H+/sugar transport, among other mechanisms.  相似文献   

Introducing Cash Crops in Shifting Cultivation Regions – The Experience with Cardamom in Laos     

Olivier Ducourtieux  Phoui Visonnavong  Julien Rossard 《Agroforestry Systems》2006,66(1):65-76

Farmers are often blamed for destroying the tropical forest, especially in Laos. Converting shifting cultivation into cash crop based agriculture is frequently presented as the solution for merging forest protection and poverty alleviation, but many attempts have ended in failure. A rural development project has attempted to introduce medicinal cardamom (Amomum villosum) cultivation in the notably remote region of Phongsaly (northern Laos), for export to China. With nearly 300 ha planted, the crop now involves about 75% of the farmers in the region. Farmers fitted cardamom into their farming system, to suit their needs for sustainability with a crop compatible with existing practices. Results indicate that introducing a cash crop into a shifting cultivation region is possible if a greater attention is paid to: (i) appraise how the new crop fits into the farming systems; (ii) prioritise economic issues over agronomic matters, in particular identify markets, traders or commercial risks.  相似文献   

Anatomic variations of feline internal and external jugular veins     

Specchi S  Olive J  Auriemma E  Blond L 《Veterinary radiology & ultrasound》2012,53(4):367-370

We evaluated 50 feline head and neck computed tomography examinations to determine the prevalence of vascular variation in the internal and external jugular veins. We identified three distinct anatomic conformations of the internal jugular vein. No variation of external jugular vein morphology was detected. Feline patients can have different internal jugular vein morphology that should be recognized for surgical planning.  相似文献   

Alphaherpesvirus infections in semidomesticated reindeer: A cross-sectional serological study     

Carlos G. das Neves  Julien Thiry  Eystein Skjerve  Nigel G. Yoccoz  Espen Rimstad  Etienne Thiry  Morten Tryland 《Veterinary microbiology》2009,139(3-4):262-269

Alphaherpesviruses infect a wide range of animal species and cause diseases. Cervid herpesvirus 2 (CvHV-2) was originally isolated from reindeer in Finland but the impact of CvHV-2 infections on reindeer remains unclear. CvHV-2 infection could be partly responsible for calf losses as there are indications that it is associated with abortions and neonatal diseases. Previous serosurveys of reindeer (Rangifer tarandus tarandus) have shown that an alphaherpesvirus is circulating among reindeer in Norway. The aim of the present study was to determine the prevalence of CvHV-2 infection among reindeer in various herding districts in Finnmark, the largest reindeer area in Norway, and to identify factors associated with becoming infected with CvHV-2. A total of 3062 serum samples were tested using an ELISA and a sub-set of samples was further tested using a seroneutralization test. The ELISA revealed that 49% of samples were positive. Extrapolation of the results to the total population (111,350 animals; 66% of the Finnmark reindeer population) showed that the seroprevalence in the population was 48%. Seroprevalence varied from 7.6% to 90.7% between districts and was affected by age, weight and population density. ELISA-positive samples neutralized CvHV-2 at serum dilutions greater than those required for neutralization of bovine herpesvirus type 1. It is concluded that CvHV-2 is endemic throughout the reindeer herding districts of northern Norway.  相似文献   

Climatic significance of glacier retreat and rockglaciers re-assessed in the light of cosmogenic dating and weathering rind thickness in Clarée valley (Briançonnais,French Alps)     

Etienne Cossart  Monique Fort  Didier Bourles  Julien Carcaillet  Romain Perrier  Lionel Siame  Régis Braucher 《CATENA》2010

Recent advances in geochronology provide opportunities to identify the glacial and periglacial sequences in mountain area. In this paper, we focus on the Upper Durance catchment (Southern French Alps), in the Clarée valley, where no absolute chronological benchmark was defined. Glacial remnants and periglacial features were investigated, integrated within a chronological scenario thanks to relative (weathering rind thickness) and absolute (CRE technique) dates. We find evidence of the existence of a Late-Glacial valley glacier, that has never been reported before. Then the upper valleys became ice-free during a period corresponding to the Early-Holocene Climate Optimum, whereas two sequences of cirque glaciation are identified during the second half of the Holocene. We also show evidence of three main generations of rockglaciers, which also mainly developed during the second half of the Holocene, probably at the end of the Subboreal period. The location and the altitudes of rockglaciers are strongly dependent on the geomorphic setting (especially the location of the sediment sources), hence complicating their palaeo-climatic interpretations.  相似文献   

Simulations of multipurpose water availability in a semi-arid catchment under different management strategies     

Julien Burte  Jean-Yves Jamin  Horst Frischkorn 《Agricultural Water Management》2009,96(8):1181-1190

In the semi-arid Brazilian Northeast, the exploitation of alluvial aquifers for irrigation and domestic supply to rural communities over the last 10 years has upset the traditional mechanisms of water resources management. In the Forquilha watershed (221 km²; 5°17″S, 39°30″W), the two main water resources are reservoirs (with a capacity exceeding 0.9-6.7 × 10⁶ m³), used for domestic water supply only, and an alluvial aquifer (2.3 × 10⁶ m³), used for irrigation and domestic water supply. From 1998 to 2006, the irrigated area with alluvial groundwater increased from 0 to 75 ha, and the fraction of population supplied through domestic water networks, using reservoirs and the aquifer, increased from 1% to 70%. Based on physical and socioeconomic issues, three main water territories have been defined (“Aquifer”, “Reservoirs”, and “Disperse Habitat”). Considering the next 30 years with a realistic population growth, three hypotheses regarding irrigated area (i.e., 0, 75, or 150 ha), and several possible water-management scenarios, hydrological balance models were built and used to simulate the different impacts on water resource availability and salinity. Simulation results showed that, in all cases, releases from the upstream main reservoir are necessary to keep reservoir salinity below 0.7 g L⁻¹ and for guaranteeing domestic needs in the whole watershed. As a consequence, a management approach that takes into account the interrelations among the three territories is necessary. Moreover, the simulations showed that the area of irrigated fields cannot exceed the current extent (75 ha), or serious restrictions on water availability and salinity will take place. Moreover, important socioeconomic problems are expected, including a high cost of palliative water supply with tank trucks from external sources.  相似文献   

Effects of breeding date,weaning date,and grazing season length on profitability of cow-calf production systems in southeastern Montana     

Julien DJ  Tess MW 《Journal of animal science》2002,80(6):1462-1469

Production data from 11 southeastern Montana ranches were used to parameterize a bio-economic computer model of cow/calf range production. Effects of changes in breeding date, weaning date, and range removal date on system performance for a ranch with a fixed forage resource base (3,060 animal unit months of range forage and 744 t of hay) were simulated. Input costs were locally established in 1994. Cattle prices were determined by week from 13-yr averages. For the base scenario, breeding season was 66 d with breeding starting on June 9. Weaning, range removal, and calf sales occurred on November 3. Cows were fed stored forages from November 3 until turnout to grazing (May 1). Five replications were simulated for combinations of breeding, weaning, and range removal dates in a factorial design. Each factor was deviated from the base scenario by +/- 14 and 28 d. Production efficiency was measured by break-even steer price. Gross margin (gross revenue - variable costs) was used as a measure of profitability. Increasing calf age (and weight) at sale time, by decreasing breeding date and(or) increasing weaning date, improved ranch efficiency and profitability. Increasing range removal date improved system performance even though extending the grazing season led to decreased herd size. Compared to the base system, the best system increased gross margin by approximately 17%. Responses for gross margin reflect the dynamics of herd size, purchased feed expense, and production efficiency. Results suggest that for range-based cow-calf enterprises in the northern Great Plains, production efficiency and profitability may be improved by increasing calf weaning age and extending the grazing season, even if herd size must be reduced.  相似文献   

Evaluation of lymphocyte apoptosis in dogs with inflammatory bowel disease     

Dandrieux JR  Bornand VF  Doherr MG  Kano R  Zurbriggen A  Burgener IA 《American journal of veterinary research》2008,69(10):1279-1285

Objective-To determine whether lymphocyte apoptosis in intestinal mucosae is more common in healthy dogs than dogs with inflammatory bowel disease (IBD) and whether numbers of apoptotic cells increase after successful treatment of affected dogs. Animals-8 dogs with IBD (IBD dogs) and 8 healthy control dogs. Procedures-Biopsy specimens of the duodenum and colon were obtained via endoscopy from dogs with IBD before and after 10 weeks of standard treatment and compared with specimens obtained from control dogs. Expression of activated caspase 3 (Casp3), caspase-cleaved fragment p85 from poly-ADP-ribose polymerase (PARP), and B-cell leukemia/lymphoma 2 (Bcl-2) was measured in the duodenal (villous tip and base) and colonic mucosae. Results-Expression of Casp3 was greater in the duodenal villous tips of control dogs, compared with expression in similar tissues from dogs with IBD before or after treatment. Despite clinical improvement of dogs with IBD, expression of Casp3 did not increase after treatment. Expression of PARP did not differ between groups at any time point. Expression of Bcl-2 was greater at all 3 tissue sites in control dogs, compared with expression at the same sites in dogs with IBD. Furthermore, Bcl-2 expression in duodenal villous tips was higher in dogs with IBD after treatment but was not higher elsewhere. In control dogs, expression patterns for all 3 markers were similar between sites (villous tip > villous base > colon). Conclusions and Clinical Relevance-Expression of Casp3 in lymphocytes in duodenal villous tips was significantly reduced in dogs with IBD, compared with expression in healthy dogs, but no increase was detected following successful treatment of IBD. Increased expression of Bcl-2 may be a potential marker of the success of treatment.  相似文献   

Breeding sites of bluetongue vectors in northern Europe     

Zimmer JY  Haubruge E  Francis F  Bortels J  Simonon G  Losson B  Mignon B  Paternostre J  De Deken R  De Deken G  Deblauwe I  Fassotte C  Cors R  Defrance T 《The Veterinary record》2008,162(4):131

  相似文献   

Whole body barometric plethysmography: a screening method to investigate airway reactivity and acute lung injuries in freely moving pigs     

Halloy DJ  Kirschvink NA  Vincke GL  Hamoir JN  Delvaux FH  Gustin PG 《Veterinary journal (London, England : 1997)》2004,168(3):276-284

The aim of this work was to investigate whether the Penh index, measured using whole body barometric plethysmography, can be used as a screening parameter to evaluate the airway reactivity and the intensity of the pulmonary response to endotoxins. Penh was firstly recorded in non-sedated freely moving piglets exposed (1) to a nebulized acetylcholine (Ach) pre-treated or not with clenbuterol, or (2) to endotoxin challenge. To measure Penh simultaneously with total pulmonary resistance (R(L)), dynamic compliance (C(dyn)) and intrapleural pressure changes (Max Delta Ppl), an oesophageal balloon catheter technique was used and the piglets were anaesthetised. The recordings were performed during (1) an intravenous metacholine (Mch) challenge and (2) in endotoxin-exposed animals. In freely moving animals, Ach induced a significant dose-dependent increase in Penh, which was significantly blocked by clenbuterol. Endotoxin instillation also resulted in a significant rise in Penh while the corresponding response measured under anaesthesia was significantly and positively correlated with R(L) and Max Delta Ppl. Similar results were obtained during Mch challenge but the Penh was negatively correlated with C(dyn). We conclude that Penh could be used in freely moving piglets as a screening index for airway reactivity and pulmonary functional changes in cholinergic and endotoxin challenges.  相似文献