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911.
912.
The Andean Condor (Vultur gryphus) in Ecuador is classified as Critically Endangered. Before 2015, standardized and systematic estimates of geographic distribution, population size and structure were not available for this species, hampering the assessment of its current status and hindering the design and implementation of effective conservation actions. In this study, we performed the first quantitative assessment of geographic distribution, population size and population viability of Andean Condor in Ecuador. We used a methodological approach that included an ecological niche model to study geographic distribution, a simultaneous survey of 70 roosting sites to estimate population size and a population viability analysis (PVA) for the next 100 years. Geographic distribution in the form of extent of occurrence was 49 725 km2. During a two-day census, 93 Andean Condors were recorded and a population of 94 to 102 individuals was estimated. In this population, adult-to-immature ratio was 1:0.5. In the modeled PVA scenarios, the probability of extinction, mean time to extinction and minimum population size varied from zero to 100%, 63 years and 193 individuals, respectively. Habitat loss is the greatest threat to the conservation of Andean Condor populations in Ecuador. Population size reduction in scenarios that included habitat loss began within the first 15 years of this threat. Population reinforcement had no effects on the recovery of Andean Condor populations given the current status of the species in Ecuador. The population size estimate presented in this study is the lower than those reported previously in other countries where the species occur. The inferences derived from the population viability analysis have implications for Condor management in Ecuador. This study highlights the need to redirect efforts from captive breeding and population reinforcement to habitat conservation. 相似文献
913.
Miguel Angel Martínez‐Morales Iriana Zuria Leonardo Chapa‐Vargas Ian MacGregor‐Fors Rubén Ortega‐Álvarez Edgar Romero‐Águila Pilar Carbó 《Diversity & distributions》2010,16(5):786-797
Aim The Rufous‐backed Robin Turdus rufopalliatus is a bird endemic to the Pacific slope of Mexico. The species recently established populations in several localities in the Mexican Central Highlands. Based on available data, we modelled the range expansion of the Rufous‐backed Robin in Mexico to understand the pattern, mechanisms and ecological and biogeographic implications of its expansion. Location Mexico. Methods We assessed the species’ presence and habitat requirements at two spatial scales. At the site level, we evaluated the relationship between land use and species presence in an urban environment. At the country level, we generated a niche model. We then produced a dispersion model through the interpolation of points generated from information derived from the niche model, the location of records within and outside its native distribution range, the species’ natural history, habitat requirements and its estimated dispersion rate (4.2 km year?1). Results The dispersion model predicted that the species will significantly increase its distribution range in Mexico in the coming decades. Its expansion would occur by a stepping‐stone colonization of suitable habitat in areas of native vegetation and human settlements. The model predicted that the species should arrive on the Gulf slope of Mexico before 2025. Main conclusions Mechanisms that could explain the species’ success in establishing viable populations outside its native distribution include its dispersion ability, competitive release, the urban heat island phenomenon and the trade of wild birds. The geographic range expansion of the Rufous‐backed Robin will probably create new interactions with other species, particularly with close taxonomic and ecological relatives. The increase in the distribution range of the Rufous‐backed Robin has resulted from direct and indirect human‐induced dispersion; therefore, it cannot be considered a fading endemism. In part of its expanded range (to date the Mexican Central Highlands), it should be considered an invasive alien species. 相似文献
914.
915.
Kate Morrow Guthrie Sara Vargas Julia G. Shaw Rochelle K. Rosen Jacob J. van den Berg Patrick F. Kiser Karen Buckheit Dana Bregman Lara Thompson Kathleen Jensen Todd Johnson Robert W. Buckheit 《PloS one》2015,10(12)
Intravaginal rings (IVRs) are currently under investigation as devices for the delivery of agents to protect against the sexual transmission of HIV and STIs, as well as pregnancy. To assist product developers in creating highly acceptable rings, we sought to identify characteristics that intravaginal ring users consider when making decisions about ring use or non-use. We conducted four semi-structured focus groups with 21 women (aged 18–45) who reported using an IVR in the past 12 months. Participants manipulated four prototype rings in their hands, discussed ring materials, dimensionality, and “behavior,” and shared perceptions and appraisals. Five salient ring characteristics were identified: 1) appearance of the rings’ surfaces, 2) tactile sensations of the cylinder material, 3) materials properties, 4) diameter of the cylinder, and 5) ring circumference. Pliability (or flexibility) was generally considered the most important mechanical property. Several ring properties (e.g., porousness, dimensionality) were associated with perceptions of efficacy. Women also revealed user behaviors that may impact the effectiveness of certain drugs, such as removing, rinsing and re-inserting the ring while bathing, and removing the ring during sexual encounters. As product developers explore IVRs as prevention delivery systems, it is critical to balance product materials and dimensions with use parameters to optimize drug delivery and the user experience. It is also critical to consider how user behaviors (e.g., removing the ring) might impact drug delivery. 相似文献
916.
Patrícia Fernanda Schuck Estela Natacha Brandt Busanello Alana Pimentel Moura Anelise Miotti Tonin Mateus Grings Luciana Ritter Carmen Regla Vargas Gustavo da Costa Ferreira Moacir Wajner 《Neurochemical research》2010,35(2):298-305
High concentrations of ethylmalonic acid are found in tissues and biological fluids of patients affected by ethylmalonic encephalopathy,
deficiency of short-chain acyl-CoA dehydrogenase activity and other illnesses characterized by developmental delay and neuromuscular
symptoms. The pathophysiological mechanisms responsible for the brain damage in these patients are virtually unknown. Therefore,
in the present work we investigated the in vitro effect of EMA on oxidative stress parameters in rat cerebral cortex. EMA
significantly increased chemiluminescence and thiobarbituric acid-reactive species levels (lipoperoxidation), as well as carbonyl
content and oxidation of sulfhydryl groups (protein oxidative damage) and DCFH. EMA also significantly decreased the levels
of reduced glutathione (non-enzymatic antioxidant defenses). In contrast, nitrate and nitrite levels were not affected by
this short organic acid. It is therefore presumed that oxidative stress may represent a pathomechanism involved in the pathophysiology
of the neurologic symptoms manifested by patients affected by disorders in which EMA accumulates. 相似文献
917.
Allergic sensitization increases the amount of extracellular ATP hydrolyzed by guinea pig leukocytes
Chávez Jaime Vargas Mario H. Martínez-Zúñiga Jesús Falfán-Valencia Ramcés Ambrocio-Ortiz Enrique Carbajal Verónica Sandoval-Roldán Rosa 《Purinergic signalling》2019,15(1):69-76
Purinergic Signalling - Increased levels of ATP have been found in the bronchoalveolar lavage of patients with asthma, and subjects with this disease, but not healthy subjects, develop bronchospasm... 相似文献
918.
Renata da Silva Pereira Saccol Karine Lanes da Silveira Stephen Adeniyi Adefegha Alessandra Guedes Manzoni Leonardo Lanes da Silveira Ana Paula Visintainer Coelho Livia Gelain Castilhos Ftima Husein Abdalla Lara Vargas Becker Nara Maria Beck Martins Juliana Sorraila Oliveira Emerson Andr Casali Daniela Bitencourt Rosa Leal 《Cell biochemistry and function》2019,37(7):474-485
919.
920.
T. A. Green R. J. Prokopy R. I. Vargas D. Kanehisa C. Albrecht 《Entomologia Experimentalis et Applicata》1993,66(1):13-20
Promising diets were screened and the most successful modified with additives used in artificial diets for other entomophagous
insects. Two suitable diets were obtained, one for adults and one for larvae ofChilocorus nigritus (Fabricius) (Coleoptera: Coccinellidae). They were still inferior to natural prey and not adequate as the sole food source
for rearing consecutive generations. They are valuable as substitute food in the insectary during shortages of natural prey.
Oleander scaleAspidiotus nerii Bouché andAsterolecanium miliaris (Boisduval) were evaluated as natural prey forC. nigritus and two other potential biocontrol agents in southern Africa,C. bipustulatus (Linnaeus) andC. infernalis Mulsant.A. nerii andA. miliaris were suitable for all life stages ofC. nigritus and adults ofC. bipustulatus andC. infernalis. A. miliaris was inadequate for larvae ofC. bipustulatus andC. infernalis. 相似文献