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161.
Leandro Silveira Rahel Sollmann Anah T. A. Jácomo José A. F. Diniz Filho Natália M. Tôrres 《Landscape Ecology》2014,29(7):1213-1223
Most large reserves in Brazil do not hold viable populations of jaguars to guarantee the species’ long-term survival. Corridors linking populations have been identified as a potential tool to avoid negative effects of isolation, increasing population viability. Here, we performed a Brazil-wide evaluation of potential large scale corridors connecting protected jaguar populations. Six variables (human population size, dam reservoir size, number of dams, roads, railways and cities) expected to negatively impact jaguar movement were analyzed across 180 potential corridors connecting 298 protected jaguar areas. We established overall disturbance scores for the corridors using a principal components analysis and compared them among the Brazilian biomes. We further investigated which variables separated biomes using a canonical variates analysis. The Atlantic Forest and the semi-arid Caatinga have the most impacted potential corridors, whereas the Amazon and Pantanal still have the best potential corridors. Corridor quality in the Cerrado grasslands was intermediate. All variables but human population size and corridor length contributed significantly to differences in corridor variables among biomes. Our conclusions suggest that we need to plan the implementation of large scale corridors in the Amazon, Pantanal and particularly the Cerrado soon, while potential corridors might still be economically viable. In the much more impacted Atlantic Forest and Caatinga, the need for conservation actions is strongest, but logistical difficulties and costs may turn implementation of corridors unfeasible. 相似文献
162.
Silvio F. B. Ferraz Katia M. P. M. B. Ferraz Carla C. Cassiano Pedro Henrique S. Brancalion Daniela T. A. da Luz Thais N. Azevedo Leandro R. Tambosi Jean Paul Metzger 《Landscape Ecology》2014,29(2):187-200
Native forests play an important role regarding ecosystem services related to biodiversity, water, and nutrient cycling, and the intensity of those services should be related to the amount, configuration and quality of the forest. However, in highly dynamic landscapes, such as some tropical regions, ecosystem services are potentially affected not only by the present landscape structure, but also by the historical land use. Here we propose a simple methodological framework to evaluate the contribution of past landscape dynamics and present landscape structure in the provision of ecosystem services. We applied this framework to a traditional agricultural landscape from the Brazilian Atlantic Forest hotspot, where natural forests cover has increased from 8 to 16 % in the last 60 years (1962–2008), and where old forests are being reduced while young forests are being regenerated. Forests of different ages, in association with current landscape structure, reveal a mosaic of forest patches under different conditions, implying different abilities to deliver ecosystem services. With the replacement of old-growth forests by young-regenerating forests and a high level of forest fragmentation, less than 1/4 of the current forest cover is able to fully satisfy the ecosystem service demands. To avoid such tendency, government policies should not only focus on increasing forest cover, but also in conserving old-growth forest fragments or increasing forest quality. The proposed methodology allows integrating historical land use and current landscape structure to evaluate ecosystem services provision and can be useful to establish programs of payment for ecosystem services. 相似文献
163.
Gretchen L. Stokes Leandro Castello Thiago A. Petersen Steven J. Cooke Michael Power Jansen Zuanon Eduardo G. Martins 《水产资源保护:海洋与淡水生态系统》2021,31(6):1257-1268
- Arapaima (Arapaima sp.) are highly overexploited fish endemic to the Amazon basin. Because the fish are obligate air-breathers, it is possible to use surface-breathing events to count individuals visually for population censuses important for conservation, yet uncertainties remain about body size and environmental influences on air-breathing intervals, and thus count accuracy.
- This study examined relationships between breathing intervals and environmental parameters (e.g. water temperature and transparency) and body size for radio-tagged arapaima (n = 12) in an upland river-floodplain (Lake Ayapuá, Amazonas, Brazil). Generalized additive mixed models were used to evaluate environmental, size, and behavioural correlates of breathing intervals.
- Temperature was the most influential predictor of air-breathing intervals, followed by body size. The shortest breathing intervals were associated with consecutive ‘aggressive’ breaths while the longest breathing intervals had consecutive ‘calm’ breaths. Type of breath, size, and temperature predictors revealed that breathing intervals ranged from 4 to 46 min and were not significantly different among life stages ( = 15.9 min for sub-adults and adults (>1 m); = 14.8 min for juveniles (<1 m)).
- Whereas the current population census method uses fish counts in 20-min intervals, this study found that 15% of observed breaths, and two thirds of fish, took longer than 20 min to breathe. These findings were obtained in relatively cool-water environments, so it is recommended that future population census methods consider water temperature (e.g. extend intervals used for counts in cooler waters), which may improve the accuracy of census counts and thus further enhance arapaima conservation efforts.
- This study demonstrated an effective method in which fundamental biological information is used to inform and improve population census methods for an imperilled fish in a region where traditional stock assessment is ineffective. Similar approaches for adaptive stock assessments could be applied to improve conservation of other air-breathing fishes (e.g. lungfishes) globally.
164.
Ériton Egidio Lisboa Valente Mário Fonseca Paulino Edenio Detmann Sebastião Campos Valadares de Filho Lívia Vieira Barros Nelcino Francisco de Paula Sidnei Antônio Lopes Daniel Majeste de Almeida Leandro Soares Martins 《Tropical animal health and production》2013,45(2):487-495
The effects of supplementation of beef calves on weight gain, intake and digestibility of pasture, milk production and composition of their dams, and behavior of the pair cow–calf were assessed. Fifty-five beef cows with an initial average body weight of 449?±?8 kg and their respective offspring, with an initial average body weight of 138?+?3 kg and aged between 90 and 150 days, were used. Animals were submitted to an experimental period of 112 days. The experimental treatments consisted of: control?=?mineral mixture only, plan 1?=?high protein and high carbohydrate multiple supplement, plan 2?= high protein and low carbohydrate multiple supplement, plan 3?=?low protein and high carbohydrate multiple supplement, and plan 4?=?low protein and low carbohydrate multiple supplement. About 25 and 12.5 % of the protein requirements were supplied by the high and low protein supplements, respectively, and 15 and 7.5 % of total digestible nutrient requirements by the high and low carbohydrate supplements, respectively. Grazing behavior, performance, milk production, milk composition, intake, and digestibility of the cows were not affected (P?>?0.05) by the supplementation of the calves. The supplemented calves had greater (P?<?0.05) performance (as measured by final body weight, average daily gain, and final body condition score), intake and idle time, and lower (P?<?0.05) grazing time, but supplementation did not affect (P?>?0.05) suckling time and suckling frequency. It can be concluded that supplementation affects the behavior and feed intake of calves. However, it does not affect the suckling time and suckling frequency of calves. Additionally, performance, milk production, nutritional characteristics, and behavior of their dams are not affected. 相似文献
165.
Aleksandro Schafer Da Silva Alexandre Alberto Tonin Leandro Sâmia Lopes 《Journal of Equine Veterinary Science》2013
The aim of this study is to report an outbreak of lice (Bovicola equi) in horses in southern Brazil, focusing on epidemiology, diagnosis, and treatment. Twenty-three horses in a stud farm presented with intense itching, crusted lesions, focal alopecia, and scaly skin. The outbreak occurred during the winter and probably due to the absence of sanitary barriers on the property. The diagnosis was carried out based on clinical signs associated with macroscopic and microscopic visualization of lice identified as B. equi. The treatment was performed with a single dose of Fipronil (Topline® Merial Brasil, Campinas, São Paulo, Brazil) spray (0.5%), eliminating immature and adult stages of lice. The clinical signs caused by the lice in horses disappeared few days after treatment. 相似文献
166.
Caio P Fernandes Alexandre Xavier João Pedro Furtado Pacheco Marcelo Guerra Santos Rodrigo Mexas Norman A Ratcliffe Marcelo Salabert Gonzalez Cícero Brasileiro Mello Leandro Rocha Denise Feder 《Pest management science》2013,69(2):292-301
BACKGROUND: Studies were carried out to evaluate the effects of Manilkara subsericea extracts and triterpenes on the development of two species of agricultural pest insects, Oncopelus fasciatus and Dysdercus peruvianus. RESULTS: All treatments of insects with M. subsericea extracts induced mortality, delayed development and inhibited moulting. Some extracts assayed (FH, FB and FD in D. peruvianus, and FH, FB and FEA in O. fasciatus) also produced body deformities in the few adults that emerged. Other extracts (FH, FEA, FB, FD and LET in both insects), however, induced either permanent (overaged) or extranumerary nymphs, both of which were unable to achieve the adult stage and reproductive status. The insects were also treated with triterpenes (α‐ and β‐amyrin acetates) which showed high lethality at 30 days after treatment and delayed the intermoult period so that overaged nymphs were detected. CONCLUSION: The results indicate that extracts and triterpenes from Manilkara subsericea act as potent growth inhibitors of phytophagous hemipteran nymphs. It is also concluded that the mixture of several different molecules in the extracts used produces synergic effects that do not occur after using the triterpenes (PFT) alone. These secondary metabolites in the M. subsericea extracts can potentially be used in integrated control programmes against crop pests. Copyright © 2012 Society of Chemical Industry 相似文献
167.
Zimbres Barbara Furtado Mariana M. Jácomo Anah T. A. Silveira Leandro Sollmann Rahel Tôrres Natália M. Machado Ricardo B. Marinho-Filho Jader 《Landscape Ecology》2013,28(2):259-269
Landscape Ecology - The impact of deforestation and fragmentation upon ecologically important and poorly known groups is currently an important issue for conservation biology. Herein we describe... 相似文献
168.
169.
Alba Maria M. Shank Leandro B. C. Teixeria Richard R. Dubielzig 《Veterinary ophthalmology》2019,22(1):76-87
Corneal vascular neoplasms (hemangioma and hemangiosarcoma) are rare in all species. Reported cases are single case reports in a single species. Archived cases of corneal hemangioma and hemangiosarcoma from dogs, cats, and horses were obtained from the Comparative Ocular Pathology Lab of Wisconsin (COPLOW, Madison, WI), tabulated, and examined. This retrospective study describes the breeds, ages, tumor types, and characteristics of vascular neoplasms that appeared to be primarily corneal in location, in feline, canine, and equine patients, with gross and histologic images. There is a discussion of predisposing factors and speculated association with chronic ocular surface disease. 相似文献
170.
Andrs M. Komromy Dineli Bras Douglas W. Esson Ronald L. Fellman Sinisa D. Grozdanic Larry Kagemann Paul E. Miller Sayoko E. Moroi Caryn E. Plummer John S. Sapienza Eric S. Storey Leandro B. Teixeira Carol B. Toris Terah R. Webb 《Veterinary ophthalmology》2019,22(5):726-740
Canine glaucoma is a group of disorders that are generally associated with increased intraocular pressure (IOP) resulting in a characteristic optic neuropathy. Glaucoma is a leading cause of irreversible vision loss in dogs and may be either primary or secondary. Despite the growing spectrum of medical and surgical therapies, there is no cure, and many affected dogs go blind. Often eyes are enucleated because of painfully high, uncontrollable IOP. While progressive vision loss due to primary glaucoma is considered preventable in some humans, this is mostly not true for dogs. There is an urgent need for more effective, affordable treatment options. Because newly developed glaucoma medications are emerging at a very slow rate and may not be effective in dogs, work toward improving surgical options may be the most rewarding approach in the near term. This Viewpoint Article summarizes the discussions and recommended research strategies of both a Think Tank and a Consortium focused on the development of more effective therapies for canine glaucoma; both were organized and funded by the American College of Veterinary Ophthalmologists Vision for Animals Foundation (ACVO‐VAF). The recommendations consist of (a) better understanding of disease mechanisms, (b) early glaucoma diagnosis and disease staging, (c) optimization of IOP‐lowering medical treatment, (d) new surgical therapies to control IOP, and (e) novel treatment strategies, such as gene and stem cell therapies, neuroprotection, and neuroregeneration. In order to address these needs, increases in research funding specifically focused on canine glaucoma are necessary. 相似文献