996 resultados para PUERTO-RICO
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Geographical variation in the reproductive biology of widespread species often occurs at their distributional boundaries. We sought to determine whether such variation has occurred in an invasive orchid, Oeceoclades maculata, across its naturalized range. We compared its reproductive biology in a Brazilian population with that published for a population on the Caribbean island of Puerto Rico. In the state of Sao Paulo, O. maculata flowers between December and February, at the height of the rainy season. Similar fruit sets were observed in manual self (76%) and cross (70.4%) pollination treatments. The fruit set of plants protected from both pollinators and rainfall was 6.1%, whereas plants exposed only to rainfall had a fruit set of 41.4%, slightly less than the controls (48.3%). Like the Puerto Rico population, reproduction is primarily through rain-assisted autogamy, but unlike observations made on the island, outcrossing can eventually occur. We observed two butterfly species (Heliconius ethilla narcaea and Heliconius erato phyllis) pollinating O. maculata. Secretory epidermal cells and trichomes of the spur lumen produced 0.7 mu L of 25% (sucrose equivalents) nectar per flower each morning, which was stored in a dilated basal portion of the spur and reabsorbed by the afternoon. Thus, geographical variation in reproductive biology exists across the broad invasive range of O. maculata.
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A phylogenetic analysis of a fragment of the mitochondrial gene 16S was used to test the monophyletic status of Potimirim. Existing doubts on the taxonomic status of brasiliana (once P glabra) and P potimirim (once P mexicana) were clarified. Potimirim mexicana and P potimirim are distinct species according to molecular data and appendix masculina morphology. A new species (Potimirim sp. 1) from Puerto Rico was revealed with molecular data, and it is evolutionarily related to P potimirim and P mexicana according to our analysis. We found out three distinct species under the name P glabra. Then, we recommend the application of the name P glabra for the populations of the Pacific slope of Central America and revalidation of P brasiliana for the Brazilian ones. The need for a new name to those "P glabra" of the Caribbean is highlighted, and it was provisionally referred as Potimirim sp. 2. The ontogenetic (juveniles to adults) development of the appendix masculina of P brasiliana was observed and compared to the other species of Potimirim (adults). In the light of our phylogenetic hypothesis, we postulate a pattern of character addition for the evolution of the appendix masculina of Potimirim. This hypothesis is plausible for two key reasons. First. Potimirim is a monophyletic group according to our hypothesis. Second, the shape of appendix masculina found in adults of P. americana is similar and comparable to those found in the earliest juvenile stages of P brasiliana, a derived species according to our phylogeny (P americana, ((P mexicana, Potimirim sp. 1. P potimirim), (P glabra, (brasiliana, Potimirim sp. 2)))). As so, the basal P americana retain the ancestral morphological state of the appendix masculina when compared to the other species of Potimirim. In our interpretation the ontogeny of the appendix masculina recapitulated the proposed phylogeny, giving further support to it.
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Background: Kinins, with bradykinin and des-Arg(9)-bradykinin being the most important ones, are pro-inflammatory peptides released after tissue injury including stroke. Although the actions of bradykinin are in general well characterized; it remains controversial whether the effects of bradykinin are beneficial or not. Kinin-B2 receptor activation participates in various physiological processes including hypotension, neurotransmission and neuronal differentiation. The bradykinin metabolite des-Arg(9)-bradykinin as well as Lys-des-Arg(9)-bradykinin activates the kinin-B1 receptor known to be expressed under inflammatory conditions. We have investigated the effects of kinin-B1 and B2 receptor activation on N-methyl-Daspartate (NMDA)-induced excitotoxicity measured as decreased capacity to produce synaptically evoked population spikes in the CA1 area of rat hippocampal slices. Principal Findings: Bradykinin at 10 nM and 1 mu M concentrations triggered a neuroprotective cascade via kinin-B2 receptor activation which conferred protection against NMDA-induced excitotoxicity. Recovery of population spikes induced by 10 nM bradykinin was completely abolished when the peptide was co-applied with the selective kinin-B2 receptor antagonist HOE-140. Kinin-B2 receptor activation promoted survival of hippocampal neurons via phosphatidylinositol 3-kinase, while MEK/MAPK signaling was not involved in protection against NMDA-evoked excitotoxic effects. However, 100 nM Lys-des-Arg(9)-bradykinin, a potent kinin-B1 receptor agonist, reversed bradykinin-induced population spike recovery. The inhibition of population spikes recovery was reversed by PD98059,showing that MEK/MAPK was involved in the induction of apoptosis mediated by the B1 receptor. Conclusions: Bradykinin exerted protection against NMDA-induced excitotoxicity which is reversed in the presence of a kinin-B1 receptor agonist. As bradykinin is converted to the kinin-B1 receptor metabolite des-Arg(9)-bradykinin by carboxypeptidases, present in different areas including in brain, our results provide a mechanism for the neuroprotective effect in vitro despite of the deleterious effect observed in vivo.
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[EN] A meridional hydrographic section was made in August–September 1997 at 66°W from the coast of Venezuela to Woods Hole aboard the R/V Knorr. In this report, we concentrate on near surface measurements in the Caribbean. The data show two distinct water masses with different origins. From approximately 14°N to Puerto Rico, Caribbean Surface Water and Subtropical Under Water with their source in the North Atlantic are found, as previously observed. From Venezuela to approximately 13°N, a less saline water mass with its source in the Tropics and South Atlantic is found. Within the southern portion of the section, two different velocity patterns are observed, namely, an eastward flow with a subsurface maximum near the coast of Venezuela, and a surface intensified westward jet with Velocities of 130 cm s−1 in midbasin.
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L'elaborato intende proporre un'analisi sociolinguistica della comunità portoricana di New York. Il lavoro di ricerca, condotto proprio nella città di New York, ha lo scopo di fornire una prospettiva, il più ampia possibile, sull'uso dell'inglese, dello spagnolo e delle pratiche linguistiche legate allo Spanglish da parte di questa specifica comunità ispanofona. Lo studio si è concentrato prevalentemente sull'analisi del comportamento linguistico di due generazioni di portoricani, i cui usi linguistici variano in relazione a specifici parametri riscontrati all'interno dell'organizzazione sociale.
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Tropical trees have been shown to be more susceptible to warming compared to temperate species, and have shown growth and photosynthetic declines at elevated temperatures as little as 3oC above ambient. However, regional and global vegetation models lack the data needed to accurately represent physiological response to increased temperatures in tropical forests. We compared the instantaneous photosynthetic responses to elevated temperatures of four mature tropical rainforest tree species in Puerto Rico and the temperate broadleaf species sugar maple (Acer saccharum) in Michigan. Contrary to expectations, leaves in the upper canopy of both temperate and tropical forests had temperature optima that are already exceeded by mean daily leaf temperatures. This indicates that tropical and temperate forests are already seeing photosynthesis decline at mid-day temperature. This decline may worsen as air temperatures rise with climate change if trees are unable to acclimate, increasing the likelihood that forests may shift from carbon sinks to sources. A secondary study was conducted on experimentally warmed sugar maple seedlings to determine if photosynthesis had been able to acclimate to +5oC air temperature over four years. Species abundance models had predicted a decline of sugar maple within the Upper Peninsula of Michigan over the next 100 years, due to elevated temperature and altered precipitation. Instantaneous photosynthetic temperature response curves on both control and heated seedlings showed that the differences between treatments were not statistically significant, though there was a 16% increase in temperature optima and a 3% increase in maximum rates of photosynthesis in warmed plots. Though evidence of acclimation was not significant, the seedlings did not fare poorly as the models suggest.
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BACKGROUND: Renal involvement is a serious manifestation of systemic lupus erythematosus (SLE); it may portend a poor prognosis as it may lead to end-stage renal disease (ESRD). The purpose of this study was to determine the factors predicting the development of renal involvement and its progression to ESRD in a multi-ethnic SLE cohort (PROFILE). METHODS AND FINDINGS: PROFILE includes SLE patients from five different United States institutions. We examined at baseline the socioeconomic-demographic, clinical, and genetic variables associated with the development of renal involvement and its progression to ESRD by univariable and multivariable Cox proportional hazards regression analyses. Analyses of onset of renal involvement included only patients with renal involvement after SLE diagnosis (n = 229). Analyses of ESRD included all patients, regardless of whether renal involvement occurred before, at, or after SLE diagnosis (34 of 438 patients). In addition, we performed a multivariable logistic regression analysis of the variables associated with the development of renal involvement at any time during the course of SLE.In the time-dependent multivariable analysis, patients developing renal involvement were more likely to have more American College of Rheumatology criteria for SLE, and to be younger, hypertensive, and of African-American or Hispanic (from Texas) ethnicity. Alternative regression models were consistent with these results. In addition to greater accrued disease damage (renal damage excluded), younger age, and Hispanic ethnicity (from Texas), homozygosity for the valine allele of FcgammaRIIIa (FCGR3A*GG) was a significant predictor of ESRD. Results from the multivariable logistic regression model that included all cases of renal involvement were consistent with those from the Cox model. CONCLUSIONS: Fcgamma receptor genotype is a risk factor for progression of renal disease to ESRD. Since the frequency distribution of FCGR3A alleles does not vary significantly among the ethnic groups studied, the additional factors underlying the ethnic disparities in renal disease progression remain to be elucidated.
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Este artículo explora la figura del travesti en la novela de Mayra Santos- Febres, Sirena Selena vestida de pena (2000) como una metáfora cultural y punto de confluencia de diversos “intereses vestidos". Analizamos esta novela prestando atención al uso literario de la metáfora y a los simbolismos representados a través de la figura del travesti. Es interesante examinar como la literatura puertorriqueña de finales del siglo XX recurre a la figura del travesti por su poder metafórico, y Sirena Selena vestida de pena es un claro ejemplo de dicho poder metafórico de la figura del travesti, una figura que intentamos deconstruir en las siguientes páginas. Hacemos un breve recorrido por la historia del país natal de la escritora, Puerto Rico, ya que esto nos ayuda a identificar un número de metáforas y simbolismos que explotan la realidad del país, y a través de las cuales Santos-Febres llama la atención hacia la movilidad de lo marginal. Hacemos un análisis de las distintas metáforas presentes en el cuerpo del travesti, desde el país colonizado hasta una metáfora del deseo, pasando por el lenguaje, el sistema político, la modernización del país y el Caribe. Por último, analizamos el travestismo como identidad de género en el personaje de Sirena Selena. Sirena es un personaje complejo, un cruce de géneros que acusa la falta de una identidad fija. Investigamos como por medio de la voz y del idioma, toda su vida como cantante y travesti va encaminada a la búsqueda de dicha identidad, tan necesaria para la construcción de un sujeto humano.
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Fil: Pró, Diego F..
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ANTECEDENTES: La mayoría de las islas en West Indies no tienen leyes liberales sobre el aborto, ni programas para la prevención del embarazo (contracepción). El presente trabajo presenta los resultados de una revisión de la literatura sobre la actitud de los proveedores del cuidado de la salud y las mujeres hacia la contracepción y el aborto inducido (emergencia), prevalencia, métodos y aspectos jurídicos del aborto inducido y políticas de prevención. MÉTODOS: Se obtuvieron artículos de PubMed, EMBASE, MEDLINE, PsychINFO y SocIndex (1999 a 2010) que usaban como palabras claves contracepción, aborto inducido, terminación de embarazo, aborto médico y West Indies. RESULTADOS: Treinta y siete artículos correspondían al criterio de inclusión: 18 sobre contracepción, 17 sobre aborto inducido y 2 sobre ambos asuntos. Los resultados principales indicaron que los conocimientos de los proveedores de cuidado de la salud acerca de la contracepción de emergencia, eran pobres. Los estudios mostraron un conocimiento pobre de la contracepción, pero las sesiones de counseling aumentaron su efectividad. No se encontraron números exactos sobre la prevalencia del aborto. Se estima que el número total de abortos por año en West Indies es de 300 000. Uno de cada cuatro embarazos termina en aborto. El uso de misoprostol disminuyó las complicaciones de abortos inseguros.La legislación sobre el aborto varía ampliamente en las diferentes islas del Caribe: Cuba, Puerto Rico, Martinica, Guadalupe y San Martín tienen abortos legales. Barbados fue la primera isla angloparlante con legislación liberal para el aborto. Todas las otras islas tienen leyes restrictivas. CONCLUSIÓN: A pesar del alto número de abortos, según se estima, no hay investigaciones sobre la prevalencia del aborto. Los estudios mostraron un pobre conocimiento de la contracepción y un uso bajo entre los adolescentes. La mayoría de las islas del Caribe tienen leyes restrictivas contra el aborto.
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This publication is the result of a comparative analysis of laws and health regulations governing access to legal abortion in 13 countries: Bolivia, Brazil, Canada, Colombia, Guyana, Italy, Mexico, Norway, Panama, Peru, Puerto Rico, South Africa, and Spain. It seeks to promote access to safe and legal abortion services by developing health regulations and guidelines that are grounded in a human rights framework.
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El presente documento de trabajo de la Iniciativa del Caribe Sobre Aborto y Anticoncepción pretende: documentar las leyes de aborto en varios países caribeños no independientes e independientes; Examinar la relación entre las leyes de aborto (de jure) y sus aplicaciones (de facto); Analizar la continua influencia del derecho colonial en la política y práctica del aborto en el Caribe; Documentar los patrones migratorios de poblaciones caribeñas, con el propósito de asegurar servicios de aborto; Diseñar una metodología adecuada para recabar la información arriba mencionada en contextos criminales, así como legales.