The value of performance studies of irrigation projects for lending agencies     

Herve Plusquellec 《Irrigation and Drainage Systems》1993,7(4):263-271

This paper looks at the World Bank's experience with irrigation and drainage projects and compares their performance expected at appraisal stage with the performance re-assessed at completion and at the time of impact evaluation, typically 3 to 5 years later when projects have reached their full potential. This review confirms the over-optimistic assumptions of project performance at appraisal and completion stages. The deficiencies in water distribution are far greater than suspected, affecting cropping intensity and crop yields much more than originally thought. An important lesson from this memo is the need to adopt more realistic values of key parameters in the preparation of irrigation projects.  相似文献   

Distribution analyses of Meloidogyne spp. and Pratylenchus coffeae sensu lato in coffee plots in Costa Rica and Guatemala     

G. Herve  B. Bertrand  L. Villain  D. Licardie  C. Cilas † 《Plant pathology》2005,54(4):471-475

The distribution of the plant-parasitic nematodes Pratylenchus coffeae sensu lato and Meloidogyne spp. were studied in two plots, one in Guatemala ( P. coffeae and M. paranaensis ) and the other in Costa Rica ( P. coffeae and M. exigua ). The quantity of nematodes per g fresh weight root were counted for each coffee tree sampled. The distributions were aggregated, and generally fitted well to negative binomial distributions. Population aggregation was greater when a smaller number of nematodes were involved, suggesting that initial colonization develops in foci. Analyses of the relationships between population levels of the species suggested that there was competition between Pratylenchus coffeae and Meloidogyne spp. This competition was expressed differently depending on the relative population density of the different species.  相似文献   

Regional variations in the nematode worm populations of breeding ewes in New Zealand     

Herve M  McAnulty RW  Logan CM  Sykes AR 《New Zealand veterinary journal》2003,51(4):159-164

AIM: To determine whether the generic composition of nematode parasites in lactating ewes varies between geographic regions in New Zealand and whether age and fecundity of ewes affect nematode egg output. METHODS: Four ram breeding properties in each of the northern (NNI) and southern (SNI) North Island and the northern South Island (NSI) regions, together with six properties in the southern South Island (SSI) were investigated. Faecal samples were obtained on one occasion, 2-6 weeks after lambing, from at least 60 ewes on each property, stratified according to age and reproductive status. Nematode eggs were counted and coprocultures prepared to identify genera present. Information on the history of anthelmintic use on each property was also collected. RESULTS: Highest faecal egg counts (FEC) were observed from ewes in the NNI and SSI regions. Lambed hoggets and twin-rearing two-tooth ewes had higher FEC than their unlambed or single-lamb-rearing contemporaries, respectively. However, no significant effect of reproductive effort on FEC was demonstrated in mixed-aged ewes. Significant regional differences in generic composition of nematode parasites were observed: Teladorsagia spp (also referred to as Ostertagia spp) eggs made up 56% of total eggs shed from sheep in the SSI compared with14% in the NNI, and values for Haemonchus spp were 1%and 24% for these same regions, respectively. Trichostrongylus colubriformis and T. vitrinus together made up 7, 15, 13 and15% of eggs counted from sheep in the SSI, NSI, SNI and NNI, respectively. CONCLUSIONS: More comprehensive epidemiological information may suggest regional-specific approaches to the management of nematode parasites in ewes should be devised in the future.  相似文献   

Thoracoscopic treatment of bullous emphysema in 3 dogs     

Brissot HN  Dupre GP  Bouvy BM  Paquet L 《Veterinary surgery : VS》2003,32(6):524-529

OBJECTIVE: To report thorascopic partial lobectomy for treatment of bullous emphysema in dogs. STUDY DESIGN: Prospective clinical study. ANIMALS: Three dogs with spontaneous pneumothorax. METHODS: Thoracoscopy without pulmonary exclusion was used to identify bulla. The thorascope was introduced into the thorax lateral to the xyphoid process, and instrument portals were made at different levels along the thoracic wall between the third and tenth intercostal spaces. The thorascope was passed through the mediastinum to view the opposite pleural cavity. After identification of bullae, the affected lung was excised using an endoscopic stapler, and the incision line was checked for air leakage. Thoracic drains were used for air aspiration for 2 days after surgery. RESULTS: Bullae were confirmed histologically as emphysematous lesions. Lung inflation did not interfere with identification of bullae or with surgery. All dogs had full recovery without recurrence for 18 to 29 months after surgery. CONCLUSIONS: Identification and ablation of bulla can be performed thoracoscopically without pulmonary exclusion in dogs. CLINICAL RELEVANCE: Thoracoscopy offers several advantages compared with thoracotomy for treatment and diagnosis of idiopathic pneumothorax, including ease of identification of bullae and reduced postoperative pain and morbidity.  相似文献   

Validation and accreditation of a duplex real‐time PCR test for reliable in planta detection of Chalara fraxinea1     

R. Ioos  C. Fourrier 《EPPO Bulletin》2011,41(1):21-26

This work reports the optimization and provides statistically supported validation data for a real‐time detection tool targeting the emerging fungus Chalara fraxinea. The test proved to be specific and inclusive, based on computer simulation and in vitro assessments, and could detect as little as 20 fg of C. fraxinea DNA. The duplex real‐time polymerase chain reaction assay proved to be significantly more efficient and rapid than isolation on agar plates. To monitor the performance of the whole analysis process and to ensure reliability of the results, a set of controls was used systematically during the assays. A diagnosis flow diagram is proposed. The Laboratoire National de la Protection des végétaux was recently accredited by the French accreditation body for this protocol.  相似文献   

Étude anatomique, f onctionelle et radiologique de l'ensemble cervico-céphalique dorsal du Chien. Applications aux problêmes du port de tête en station erigée chez les Hominidés.     

M. Sakka    C. Aaron  D. Herve 《Anatomia, histologia, embryologia》1976,5(1):14-20

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Decreasing trend and fluctuations in the mean ring density of Norway spruce through the twentieth century     

Tony Franceschini  Jean-Daniel Bontemps  Pierre Gelhaye  Daniel Rittie  Jean-Christophe Herve  Jean-Claude Gegout  Jean-Michel Leban 《Annals of Forest Science》2010,67(8):816-816

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• Studies on wood density variations are necessary for estimating the forest carbon pool. Further, they can help predict the technological properties of wooden end-products. While there have been frequent reports on the relationships between wood density, cambial age, and ring width, there is little information about the historical trend in wood density for the last century, particularly in the context of global climate change.  相似文献    8. Conidial production and viability of Calonectria pseudonaviculata on infected boxwood leaves as affected by temperature,wetness, and dryness periods      Herve F. Avenot  Anton Baudoin  Chuanxue Hong 《Plant pathology》2022,71(3):696-701 Calonectria pseudonaviculata causes lesions on boxwood leaves and twigs. Controlled-environment experiments were conducted to determine the effects of temperature and leaf wetness period on C. pseudonaviculata sporulation on diseased (cv. Suffruticosa) leaves and of dryness periods and high temperature on conidial survival. Infected leaves were incubated in moist chambers and subjected to six temperatures (9, 13, 17, 21, 25, and 29°C) and six leaf wetness periods (0, 12, 24, 40, 48, and 72 h). Spore production was influenced significantly by wetness period, temperature, and their interaction. Increasing duration of leaf wetness and increasing temperature generally increased sporulation, with no sporulation occurring at 29°C or 9 and 13°C, except at 72 h of wetness exposure, while it was optimal at 21°C. Detached leaves with profuse conidia were subjected to a range of drying (relative humidity at 65%) times (0, 2, 4, 6, and 8 h) at two temperatures of 21 and 29°C. Conidia were then harvested and plated on water agar. Germinating conidia were counted to measure the spore viability. Spore mortality increased with increasing dryness duration at both temperatures but occurred more quickly and severely at 29 than 21°C. Overall, this study extended biological knowledge of conditions required for crucial stages of the C. pseudonaviculata disease cycle and the obtained results will be vital for developing boxwood blight forecasting and management tools.  相似文献    9. Assessment of molecular detection of Fusarium circinatum in insects and passive spore traps in Pinus radiata plantations      Jaime Aguayo  Cline Fourrier‐Jeandel  Xavier Capdevielle  Fabrice Vtillard  Dominique Piou  Eugenia Iturritxa  Ccile Robin 《Forest Pathology》2020,50(1) Fusarium circinatum is the causal agent of pitch canker, a destructive disease that threatens natural and planted pine forests around the world. Although pitch canker has caused problems in Spain and Portugal, concerning Europe as a whole, the fungus is not established across the pine distribution area. Its dispersion by wind and/or insect vectors could nevertheless play a role in the colonization of currently uninfected stands. It is therefore crucial to develop monitoring tools for its detection. To this end, we assessed the molecular detection of the pathogen in environmental samples of bark beetles and passive spore traps, collected in two infected Pinus radiata plantations in Basque country, Spain. The spread pattern of F. circinatum was assessed by an experimental design that included insect and spore traps installed at the centre, at the edge and outside the plots. Our results showed that F. circinatum was detected in both types of samples, at almost all collection dates. In both type of samples, positive detections were mainly found at the centre of the plots, a lower proportion at the edge, and very few outside. This suggests that long‐distance dispersion of Fusarium circinatum does not rely on wind spore dispersal neither on insect flight. Our study also shows that molecular methods are a powerful tool to monitor the pathogen in environmental samples.  相似文献    10. Off-Season Spawning of Eurasian Perch Perca Fluviatilis      Herve Migaud  Jean-Noel Gardeur  Patrick Kestemont  Pascal Fontaine 《Aquaculture International》2004,12(1):87-102 This study was designed to determine the effects of the selection for body weight and of two final warming durations during an out-of-season reproductive cycle on gonad recrudescence, plasma steroid levels and spawning in Eurasian perch Perca fluviatilis males and females. Two different bodyweight classes (200–250 and 350–400 g) and two different warming periods (1 or 2 months) were studied.At the end of the chilling period, a significant effect of the selection for body weight was observed on gonad development whereas fish were the same age. According to higher levels in testosterone (12 ng mL–1), a better development was recorded for smaller breeders (P < 0.05). A short water warming period up to 14°C (1 month v.s. 2 months) allowed higher rates of females with completed gonadogenesis (33–38% v.s. 7–8%) and spawning (31–33% v.s. 0%) (P < 0.05). Spontaneous out-of-season spawning (17 ribbons) and larvae were obtained. Relative fecundity was about 100 eggs g–1 of female body weight. Five ribbons were partly fertilized with a rate ranging from 5 to 90%. These studies have shown that delayed spawning in Eurasian perch can be obtained by a temperature manipulation, but results are not sufficient because of low stimulation rate of females, low spawning rates and high heteroge-neity of fertilization rates. The effects of other environmental factors like photoperiod should be tested in further experiment to improve the protocol inducing out-of-season spawning production.  相似文献    1 [2] [3] [4] [5] 下一页 » 末  页»