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71.
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
72.
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
73.
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
74.
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
75.
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
76.
77.
Marston Christopher G. Wilkinson David M. Reynolds Sally C. Louys Julien O’Regan Hannah J. 《Landscape Ecology》2019,34(1):131-145
Landscape Ecology - The heterogeneous mosaic nature of African savannah vegetation is a key aspect of its ecology. This study evaluates mosaic distributions and characteristics across sub-Saharan... 相似文献
78.
Ali Serhan Tarkan Gordon H. Copp Grzegorz Zięba Michael J. Godard Julien Cucherousset 《水产资源保护:海洋与淡水生态系统》2009,19(7):797-805
- 1. The crucian carp Carassius carassius is a species of cyprinid fish native to south‐east England, but few studies exist on its growth and reproduction in England, and the species is threatened by introductions of its Asiatic congener, goldfish Carassius auratus. To increase knowledge of the crucian carp as a means of aiding its conservation, the present study assesses the growth (back‐calculated length at age, body condition) and reproduction (fecundity, egg size, length and age at maturity) of crucian carp in small ponds of Epping Forest (north‐east London, England).
- 2. Evaluation of growth and reproduction data with published data for populations from northern Europe (i.e. latitude ?50°) suggest that growth is very variable, even within the same area, and that data on reproductive indices, in particular length and age at maturity, are scarce. In England, the length at age trajectory of crucian carp living in sympatry with feral goldfish Carassius auratus did not differ significantly from allopatric crucian carp populations, but crucian carp body condition and relative fecundity (eggs per body weight) were highest, and mean age and standard length at maturity were lowest in sympatry with goldfish.
- 3. These data suggest that somatic growth and reproductive output may be maximized in crucian carp when confronted by coexistence with feral goldfish. However, the potential impact of goldfish introductions on crucian carp growth and reproduction requires further study, involving a much larger number of crucian carp populations, both in allopatry and sympatry with feral goldfish populations.
79.
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
80.
Resistance Evaluation of Some Chinese Leading Rice Maintainer, Restorer lines and Their Hybrids to Magnaporthe grisea 总被引:1,自引:0,他引:1
ZHUXu-dong SHENYing HenriADREIT JulienFROUIN DidierHARREAU 《水稻科学》2004,11(3):101-105
Six isolates of Magnaporthe grisea were selected to inoculate on 10 Chinese leading maintainer lines (B-lines), 14 restorer lines (R-lines) and their F1 hybrid plants. In the tested rice materials, R-lines were proved to be more resistant to blast than B-lines. The resistance frequency of about 25% F1 hybrid plants was less than their parents. In addition, 26 isolates of M. grisea collected from different rice growing areas of China were inoculated on 13 new improved hybrid rice combinations. The resistance frequencies of 5 improved hybrids were better than those of the controls and leading varieties in rice production of China. 相似文献