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Influence of Rainfall Pattern in the Seasonal Variation of Fish Abundance in a Tropical Estuary with Restricted Marine Communication  [PDF]
Manuel Castillo-Rivera
Journal of Water Resource and Protection (JWARP) , 2013, DOI: 10.4236/jwarp.2013.53A032
Abstract:
Pueblo Viejo Lagoon is an estuary with restricted communication with the sea, so the freshwater influence tends to be more important. Therefore, the study focused on testing the hypothesis that the seasonal changes in species abundance would be mainly related to the local rainfall pattern. Monthly samplings were carried out over a one-year, using a seine net. A total of 9108 individuals were caught, corresponding to 66 species of fish, most of them with marine origin. Canonical correspondence analysis revealed that the rainfall-salinity gradient was revealed to be the most important driving force in the seasonal variation of fish composition. In this way, it was observed that seasonal fluctuations in total fish number were linked to preceding fluctuations (one month) in local rainfall. Similar pattern was exhibited by the abundance of Anchoa mitchilli (the most abundant species), Oreochromis mossambicus and Ariopsis felis, and this delayed effect was significant (cross-correlation analyses). In addition, the rainfall showed a direct influence (significant positive correlations) on abundance of D. auratus and M. martinica. The association between fish number and the rainfall regime seems to be related to lagoon productivity and the trophic responses of these species. By contrast, Brevoortia gunteri and Menidia beryllina showed an inverse correlation with rainfall. Other environmental variables (also influenced by rainfall regime) showed a significant relationship with A. hepsetus (salinity), B. chrysoura (depth) and M. curema (turbidity). Thus, at least 12 species showed some relationship with local rainfall, which accounted for 81.27% of the total number of fish collected. Although it is difficult to separate the relative importance of
A Case of Ectopic Growth Hormone Releasing Hormone (GHRH) from Pancreatic Neuroendocrine Tumor Resistant to Therapy  [PDF]
Ohoud Almohareb, Juan Rivera
Open Journal of Endocrine and Metabolic Diseases (OJEMD) , 2013, DOI: 10.4236/ojemd.2013.37037
Abstract:

Introduction: Ectopic secretion of GHRH is a rare cause of acromegaly. However, its recognition is clinically important because different therapeutic approaches are required. Case Presentation: We present a challenging case of acromegaly secondary to ectopic GHRH secretion from pancreatic neuroendocrine tumor in a 52-year-old female. The patient is treated with different modalities which include pegvisomant in an attempt to control the stimulated GH-axis considering the limited data about its use in treatment of ectopic acromegaly. Conclusion: GHRH-secreting tumor is a rare cause of acromegaly. Surgical resection of the tumor is the therapy of choice whenever possible. However, further studies are warranted for unresectable tumor or resistant cases.

Facing the 2013 Gold Rush: A Population Viability Analysis for the Endangered White-Lipped Peccary (Tayassu pecari) in Corcovado National Park, Costa Rica  [PDF]
Christian J. Rivera
Natural Resources (NR) , 2014, DOI: 10.4236/nr.2014.516085
Abstract: The white-lipped peccary (Tayassu pecari) is facing range-wide declines throughout the Neotropics. It has been eliminated from about 89% of its historical range in Costa Rica. Corcovado National Park, in the Osa Peninsula of Costa Rica, is the last remaining stronghold for the white-lipped peccary in the country. In 2013, the Park experienced a sudden gold rush that brought with it a wave of 250 miners and vigorous hunting pressures on the population. Given that the species is endangered and is susceptible to hunting due to its herding behavior and tendency to cohere and attack when threatened rather than flee, it is important to assess its probability of extinction under various hunting scenarios. Incorporating data from studies on the life history of the species throughout its range in the Neotropics and in Corcovado, I used the population viability analysis software VORTEX to simulate the population trajectories and probabilities of extinction of the species under current hunting pressures and under various management scenarios. The results of this study revealed that under the 2013 scenario where 250 miners were present in the Park, the population of white-lipped peccaries has a about a 40% chance of extinction within five years and about a 99% chance of extinction within 10 years. Moreover, there is an “extinction threshold” for the population between the presence of 100 and 150 miners hunting in the Park. At this threshold, the population growth rate, r, drops from a positive growth rate (r = 0.09, SD = 0.08) to a negative one (r = -0.07, SD = 0.29). I suggest that anti-mining and anti-poaching laws be enforced immediately, and that the number of miners be reduced to 100 at a minimum, if not completely, in order to ensure that the population of white-lipped peccaries becomes viable and evades a local extinction.
La ca?a de azúcar y sus derivados en la huasteca san luís potosí méxico
Aguilar Rivera,Noé;
Diálogos Revista Electrónica de Historia , 2010,
Abstract: sugar cane is the first and most important harvest in mexico, the sugar the change was drastic because of the larger native population and the spaniards’ interest in other commodities such as minerals and other agricultural products. in this paper its present a summary of the evolution and strategies for the development of sugar industry in la huasteca potosina san luis potosi at the viceroyalty of new spain.
Minimal
Rivera,Pablo;
ARQ (Santiago) , 2002, DOI: 10.4067/S0717-69962002005000012
Abstract: the minimal art project involved an indoor installation placed inside an art gallery in santiago, another outdoor structure located in front of a finnish museum and lately a construction placed in xxv sao paulo bienal. these works that apparently merely pursue formal games, relate to architecture from the perspective of the social housing policies, that shape, standardise, and serialise forms of life by virtue of the minimum dwelling space
Ensaio sobre o espa?o e o sujeito: Lygia Clark e a psicanálise
Rivera, Tania;
ágora: Estudos em Teoria Psicanalítica , 2008, DOI: 10.1590/S1516-14982008000200004
Abstract: an essay about space and subject: lygia clark and psychoanalysis. the present essay defends the idea that the psychoanalytic reflection about the subject implies a consideration of space and its configuration as freud's topical concern and lacan's topological search already indicate. the displacement of the subject would thus be joined by a subversion of space, which has been culturally explored, throughout the 20th century, by works of modern and contemporary art. therefore a dialogue with this body of work is sought; a dialogue which is specifically focused on the works of brazilian artist lygia clark, so as to propose, as a counterpoint to such works, renewed considerations concerning the psychic work throughout fantasy.
Abonos verdes e inoculación micorrízica de posturas de cafeto sobre suelos Fersialíticos Rojos Lixiviados
Rivera,R;
Cultivos Tropicales , 2010,
Abstract: sorghum vulgare, crotalaria juncea and canavalia ensiformis were seeded and characterized, with the aim of evaluating green manure management in the mycorhized coffee seedling production on chromic luvisols; after 70 days, they were added to the soil for obtaining different substrates, in order to study seedling response to g. fasciculatum inoculation, on a randomized complete design with (5x2) factorial arrangement, besides including the treatments of single soil and soil/earthworm humus (3/1). inoculation of the same effective strain was further studied on the substrates, made up of complementary earthworm humus added to the incorporated sorghum, at the rates of 9/1, 7/1, 5/1, besides including both treatments through a (6x2) factorial arrangement. the greatest dry weight production as well as the highest p and k extractions by sorghum, and n extractions by crotalaria were recorded. green manures increased coffee growth and native mycorhization; however, there was always a significant coffee response to inoculation, with the biggest effects in the substrate made up by crotalaria. nevertheless, even in presence of such a substrate, inoculated seedlings did not show an effective mycorhization and they were inferior to those obtained by the reference treatment of soil/humus (3/1). therefore, to obtain healthy seedlings and an effective mycorhization, it was necessary, besides inoculating, to add complementary earthworm humus at the rate of 9/1 on the incorporated crotalaria substrate.
Internacionalización de movimientos sociales. ?Cuán efectivas son las redes transnacionales de apoyo
Rivera,Claudio;
Papel Politico , 2010,
Abstract: environmental conflicts reflect and reproduce power configurations. this paper assesses three environmental conflicts in chile's post-transition in which different actors such as developers, state agencies, grassroots organizations and environmental ngos collide over the use of natural resources. using the literature on transnational advocacy networks as analytical framework the paper analyzes the conditions under which local environmental conflicts reach international visibility. the paper discusses how two interdisciplinary field such as environmental justice and political ecology to could advance in a better understanding of the effectiveness of networks at the international, national and local levels.
Estudios sobre represión estatal en regímenes democráticos: Teorías, métodos, hallazgos y desafíos
Rivera, Mauricio;
Política y gobierno , 2010,
Abstract: some democracies around the world -including those from latin america- present equal or higher levels of state repression than the global mean of autocratic regimes. despite the political and normative relevance of this phenomenon, comparative research on democratic repression is scanty and poorly systematized. introducing the distinction between centralized and decentralized state repression, and considering advances derived from the global agenda and area studies of latin america, this article presents a review of theories and empirical explanations that can contribute to the construction of a theory of democratic state repression. moreover, this paper presents a catalog about the challenges related to the processes of theory generation and empirical evaluation, and offers alternatives to those challenges. the main conclusion is that modeling the use of state violence in terms of principal-agent relations (electedpoliticians-state security agencies, state security agencies-citizenship) la-area studies offer fruitful analytical tools for comparative research on democratic state repression.
A letra e a imagem: Gary Hill, videoarte e psicanálise
Rivera, Tania;
Psicologia & Sociedade , 2009, DOI: 10.1590/S0102-71822009000400006
Abstract: this paper investigates the relationship between image and language, especially by using the lacanian concept of letter. this question is particularly explored in two works by the american videoartist gary hill: around and about (1980) and ura aru (1985-86). we argue that the letter has two ways of incidence: a mix with image or a strong tension with it. this tension can, in some conditions, lead to a break in specular mode of functioning and provoke a kind of reversion of the imaginary, letting us approach what we name the "reverse of the imaginary". in this turning, the subject emerges in his utopic condition, since he has no definite place, but stands in an unforeseeable future.
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