Landscape change under indirect effects of human use: the Savanna of Central Chile     

Eduardo R. Fuentes  Reinaldo Avilés  Alejandro Segura 《Landscape Ecology》1989,2(2):73-80

The Chilean Intermediate Depression to the north of Santiago has experienced a physiognomical transformation from a Prosopis chilensis woodland to an Acacia caven savanna. Today P. chilensis trees are scarce and belong mostly to the larger size classes. By contrast A. caven seems to reproduce frequently and its populations consist of individuals of all size classes. In this paper we document these changes and report the results of tests aimed at determining the causes of these physiognomical changes. We found that livestock, leporids, introduced Mediterranean forbs and agriculture account for differences in seed dispersal and survival of A. caven and P. chilensis, which can explain the documented changes in the Chilean landscape.  相似文献   

Occurrence of horse sickness virus type 9 in the Republic of Algeria: identification of virus strains isolated in 1965-1966     

E Pilo-Moron  J Vincent  P Sureau 《Revue d'élevage et de médecine vétérinaire des pays tropicaux》1967,20(1):5-20

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Morphogenesis in leaf and single-cell cultures of mature Juniperus oxycedrus     

Gomez MP  Segura J 《Tree physiology》1996,16(8):681-686

Single cells were mechanically isolated from leaf-derived callus of mature Juniperus oxycedrus L. These cells divided and gave rise to callus when plated on medium containing growth regulators. Best plating efficiency was obtained on a modified Schenk and Hildebrandt medium supplemented with 0.6 micro M 2,4-dichlorophenoxyacetic acid and 100 mg l(-1) casein hydrolyzate. Although single-cell-derived callus showed poor morphogenic potential, both adventitious shoots and embryogenic tissues differentiated from the callus. We also achieved induction of somatic embryogenesis in leaf explants of mature J. oxycedrus trees cultured in the presence of 6.0 or 10.0 micro M 2,4-dichlorophenoxyacetic acid or picloram. Frequency of embryogenic callus ranged from 6 to 18%; however, under the culture conditions tested, isolated embryos failed to develop into plants.  相似文献   

Anatomical characterization of hoof growth pattern in six Iranian sheep breeds and its possible implication for trimming recommendations     

Azarpajouh  S.  Marchewka  J.  Segura Correa  J. C.  Calderón Díaz  J. A. 《Tropical animal health and production》2018,50(6):1343-1348

Tropical Animal Health and Production - The objective of this study was to compare hoof anatomy, hoof growth pattern, and hoof weight-bearing surface of six different Iranian sheep breeds to...  相似文献   

Diagnostic accuracy of optical coherence tomography for assessing surgical margins of canine soft tissue sarcomas in observers of different specialties     

Josephine A. Dornbusch  Laura E. Selmic  Pin‐Chieh Huang  Jonathan P. Samuelson  Eric M. McLaughlin  Vincent A. Wavreille  Jessica A. Ogden  Brittany Abrams  Alex Kalamaras  Eric Green  Eric T. Hostnik  Lincoln Every  Jason A. Fuerst  Ryan Jennings  Christopher Premanandan  Joshua N. Lorbach  Sarah C. Linn  Aneesh Alex  Janet E. Sorrells  Lingxiao Yang  Stephen A. Boppart 《Veterinary surgery : VS》2021,50(1):111-120

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Opioid requirements after locoregional anaesthesia in dogs undergoing tibial plateau levelling osteotomy: a pilot study     

Vincent Marolf  Claudia Spadavecchia  Nicole Müller  Charlotte Sandersen  Helene Rohrbach 《Veterinary anaesthesia and analgesia》2021,48(3):398-406

ObjectiveTo determine the intraoperative and early postoperative opioid requirement after ultrasound-guided sciatic and/or femoral nerve block or epidural anaesthesia in dogs undergoing tibial plateau levelling osteotomy (TPLO).Study designProspective, masked, pilot, randomized, clinical trial.AnimalsA total of 40 client-owned dogs undergoing TPLO.MethodsEach dog was randomly assigned to group SF (combined sciatic and femoral nerve block), group S (sciatic nerve block), group F (femoral nerve block) or group E (epidural anaesthesia). A total of 0.3 mL kg^–1 of ropivacaine 0.5% was administered to each nerve or in the epidural space. Intraoperatively, fentanyl (2 μg kg^–1) was administered intravenously when heart rate, mean arterial pressure or respiratory rate increased by >30% compared with baseline values. Postoperatively, a visual analogue scale (VAS) and a modified German version of the French pain scale (4AVet) were used to assess pain every 30 minutes for 150 minutes and again once the morning after surgery. Methadone (0.1 mg kg^–1) was administered intravenously if the VAS was ≥ 4 cm [maximal value 10 cm; median (interquartile range)] or the composite pain score was ≥5 [maximal value 15; median (interquartile range)]. Significance was defined as p ≤ 0.05.ResultsGroups SF and E required less total intraoperative and early postoperative opioid doses compared with groups S and F (p = 0.031). No dogs in group SF had a block failure or required postoperative methadone. A reduced methadone requirement was found in group SF compared with all the other groups up to 150 minutes after recovery (p = 0.041).Conclusions and clinical relevanceCombined sciatic and femoral nerve block and epidural anaesthesia lead to less cumulative consumption of perioperative opioids than single nerve blockade. Sciatic or femoral nerve block alone might be insufficient to control nociception and early postoperative pain in dogs undergoing TPLO.  相似文献   

Streptococcus suis infections in humans: the Chinese experience and the situation in North America   总被引：3，自引：0，他引：3  

Gottschalk M  Segura M  Xu J 《Animal health research reviews / Conference of Research Workers in Animal Diseases》2007,8(1):29-45

Infections caused by Streptococcus suis are considered a global problem in the swine industry. In this animal species, S. suis is associated with septicemia, meningitis, endocarditis, arthritis and, occasionally, other infections. Moreover, it is an agent of zoonosis that afflicts people in close contact with infected pigs or pork-derived products. Although sporadic cases of S. suis infection in humans have been reported, a large outbreak due to S. suis serotype 2 emerged in the summer of 2005 in Sichuan, China. A similar outbreak was observed in another Chinese province in 1998. Symptoms reported in these two outbreaks include high fever, malaise, nausea and vomiting, followed by nervous symptoms, subcutaneous hemorrhage, septic shock and coma in severe cases. The increased severity of S. suis infections in humans, such as a shorter incubation time, more rapid disease progression and higher rate of mortality, underscores the critical need to better understand the factors associated with pathogenesis of S. suis infection. From the 35 capsular serotypes currently known, serotype 2 is considered the most virulent and frequently isolated in both swine and humans. Here, we review the epidemiological, clinical and immunopathological features of S. suis infection in humans.  相似文献   

Assessment of the socio-economic impacts associated with the arrival of apple snail (Pomacea canaliculata) in Mwea irrigation scheme,Kenya     

Kate L. Constantine  Fernadis Makale  Idah Mugambi  Duncan Chacha  Harrison Rware  Alexander Muvea  Vincent K. Kipngetich  Justice Tambo  Adewale Ogunmodede  Djami Djeddour  Corin F. Pratt  Ivan Rwomushana  Frances Williams 《Pest management science》2023,79(11):4343-4356

Background

In Kenya, rice (Oryza sativa L.) is mainly produced under irrigation by small-scale farmers. Mwea irrigation scheme (MIS) in Kirinyaga County accounts for 80–88% of rice production. Here, rice is the main source of livelihood and a source of revenue generation for the county. However, a recently established invasive freshwater snail, Pomacea canaliculata (Lamarck) (family: Ampullariidae), a species of apple snail, presents a serious threat to rice production.

Results

Household surveys, focus group discussions and key informant interviews highlight apple snail as a serious problem in MIS. Households that observed at least a moderate level of infestation (>20% of cultivated area) experienced significant reductions in rice yield (~14%) and net rice income (~60%). Farmers reported increased use of chemical pesticides for management of apple snail. In addition, the cost of hired labor for physical removal of egg masses and snails is resulting in substantial negative effects on net income. Farmer age, area of land owned, responsibility for decision-making, receipt of extension advice, training, and membership of a farmer organization, were all statistically significant variables to explain farmers awareness of the need for area-wide apple snail management.

Conclusion

Strategies to limit the spread of apple snail are urgently needed. A Multi-Institutional Technical Team (MITT) has been established to spearhead management efforts and consolidate advice to farmers on how to manage apple snail. However, without action to mitigate spread, the consequences could be disastrous for rice production and food security in Kenya, and for other rice growing regions across Africa. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.  相似文献   

Landscape Ecology and Species Conservation   总被引：6，自引：0，他引：6  

Burke  Vincent J. 《Landscape Ecology》2000,15(1):1-3

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Conservation planning with spatially explicit models: a case for horseshoe bats in complex mountain landscapes     

Marie Le Roux  Mathilde Redon  Frédéric Archaux  Jed Long  Stéphane Vincent  Sandra Luque 《Landscape Ecology》2017,32(5):1005-1021

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