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Texto completo SciELO Costa Rica
Texto completo
Id: lil-662241
Autor: Cebrian, Just; Stutes, Adrienne L.; Phipps, Scott; Stutes, Jason P.; Christiaen, Bart; Pennock, Jonathan R..
Título: Effects of short-term sediment nutrient enrichment and grazer (Neritina reclivata) removal on sediment microalgae in a shallow eutrophic estuary (Alabama, USA)
Fonte: Rev. biol. trop;60(4):1687-1706, Dec. 2012. ilus, graf, tab.
Idioma: en.
Resumo: The olive snail (Neritina reclivata) is ubiquitous in tropical and sub-tropical systems of the Gulf of Mexico, however its impacts on sediment microalgae have been little studied. Many coastal systems around the world are being eutrophied due to human activities, and seemingly they will continue to be eutrophied to a further extent in the future. Exploring the single and combined impacts of further nutrient enrichment and grazing by the olive snail on sediment microalgae in such eutrophic systems is an important question for our understanding and management of these systems. Here we examine the effects of short-term nutrient enrichment and grazing by the olive snail N. reclivata on sediment microalgal biomass and composition in a shallow eutrophic estuary (Weeks Bay, Alabama, USA) of the Northern Gulf of Mexico. For this, we performed a series of factorial experiments adding or not nutrients and removing or not the snail, for a total of four treatments in each experiment: ambient grazing, ambient nutrients; ambient grazing, increased nutrients; no grazing, ambient nutrients; and no grazing, increased nutrients. We did not find any significant impact of nutrient addition in any of the eight short-term (i.e. four days) experiments carried out. Impacts by the snail were minor; we only found a decrease in biomass due to snail grazing in one of the eight experiments, and no impacts on microalgal (i.e. diatom) composition. High ambient nutrient concentrations in the sediment porewater and low snail abundances on the sediment could explain these findings. Our results suggest that ephemeral, short-term nutrient pulses into eutrophic coastal systems of the Northern Gulf of Mexico, such as Weeks Bay (Alabama, USA), should not greatly affect the abundance of sediment microalgae, even though those pulses occur in well-lit areas. The results further suggest the snail N. reclivata is not a major control of sediment microalgal populations in the subtidal sedimentary areas studied. Our findings contrast with the results of past work in sediments with well-lit and nutrient poor conditions, or sediments with high densities of other snail grazers. In conjunction this and other investigations indicate that the response of sediment microalgae to nutrient enrichment and modified grazer abundance depends to a large extent on the initial levels of nutrient availability and grazing before the system is altered.

El caracol Neritina reclivata está presente en los sistemas tropicales y subtropicales del Golfo de México, sin embargo, su impacto en los sedimentos de microalgas ha sido poco estudiado. Muchos de los sistemas costeros de todo el mundo están siendo eutrofizados debido a actividades humanas, y al parecer van a seguir siendo eutrofizados en mayor grado en el futuro. La exploración de los efectos individuales y combinados de un mayor enriquecimiento de nutrientes y la herviboría por este caracol en microalgas de sedimentos en estos sistemas eutróficos es una cuestión importante para la comprensión y el manejo de estos sistemas. Aquí se examinan los efectos a corto plazo del enriquecimiento de nutrientes y herviboría del caracol de olivo sobre la biomasa y composición de microalgas de sedimentos en un estuario eutrófico superficial (Weeks Bay. Alabama, USA) del norte del Golfo de México. Para esto se llevaron a cabo una serie de experimentos factoriales añadiendo o no nutrientes y removiendo o no el caracol, para un total de cuatro tratamientos en cada experimento: ambiente con herviboría sin nutrimentos añadidos, ambiente con herviboría y nutrimentos añadidos, ambiente sin herviboría sin nutrimentos añadidos, y ambiente sin herviboría con nutrimentos añadidos. No se encontró ningún impacto significativo por la adición de nutrimentos en ninguno de los ocho experimentos a corto plazo (i.e. cuatro días). Los impactos debidos al caracol fueron menores, sólo se encontró un decrecimiento en la biomasa por herviboría del caracol en uno de los ocho experimentos, y no hubo impacto en la composición de microalgas (i.e. diatomeas). Ambientes con alta concentración de nutrimentos del sedimento y baja abundancia del caracol sobre el sedimento pueden explicar estos resultados. Los resultados obtenidos sugieren que pulsos efímeros y de corto plazo en sistemas costeros eutrofizados del Norte del Golfo de México tal como Weeks Bay (Alabama, USA), no deberían afectar de gran manera la abundancia de microalgas sobre el sedimento, a pesar de que los pulsos ocurran en áreas bien iluminadas. Además los resultados sugieren que el caracol N. reclivata no ejerce mayor control sobre las poblaciones de microalgas en las áreas submareales y sedimentarias estudiadas. Nuestros hallazgos contrastan con resultados de trabajos anteriores en sedimentos con buena iluminación y pobres condiciones nutritivas, o sedimentos con altas densidades de otros caracoles herbívoros. En conjunto, esta y otras investigaciones indican que la respuesta de microalgas en sedimentos al enriquecimiento de nutrientes y abundancia modificada de herbívoros depende en gran medida de los niveles iniciales de disponibilidad de nutrientes y herviboría antes de que el sistema se vea alterado.
Descritores: Ecossistema
Sedimentos Geológicos
Sedimentos Geológicos/microbiologia
Estações do Ano
Limites: Animais
Tipo de Publ: Research Support, Non-U.S. Gov't
Responsável: CR1.1 - BINASSS - Biblioteca Nacional de Salud y Seguridad Social

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Id: lil-356201
Autor: Velez, C. N.
Título: An overview of reported youth violence in Puerto Rico
Fonte: P. R. health sci. j;22(1):61-67, Mar. 2003.
Idioma: en.
Resumo: OBJECTIVES: The purpose of this paper is to describe the prevalence of school and youth violence in Puerto Rico based on several representative samples surveyed in the Island during the 1990's. BACKGROUND: Reviewing the available data on youth violence is necessary in order to decide the best strategies to follow in developing new ways to prevent and monitor it. METHODS: Three surveys were reviewed in this paper: The Youth Risk Behavior Survey conducted by the Center for Disease Control (1991, 1995, 1997); The Methods for the Epidemiology of Child and Adolescent Mental Disorders Study (1991); and the Youth Survey (1997-98). RESULTS: It was found that the prevalence of reported school violence in Puerto Rico tends to be somewhat lower than the prevalence reported in other sites of the U.S.A. Age and gender has a dramatic influence in the reports of youth violence in Puerto Rico. Male students are three times as likely to carry weapons than females and almost twice as likely to report hurting someone than females. Less than 10 per cent of the male students ages 12-13 report carrying a weapon while fully 30 per cent of those 18 year olds reported carrying a weapon. Being arrested also increases from only 3 per cent in the youngest students surveyed to 10 per cent on the oldest group (18 or older). CONCLUSION: The CDC has recently reported that since the early 90's there has been a decrease in reported school violence in the U.S.A. This analysis of youth surveys replicated a similar tendency for Puerto Rican youngsters. Implications for prevention programs are discussed.
Descritores: Comportamento do Adolescente
Instituições Acadêmicas/estatística & dados numéricos
Violência/estatística & dados numéricos
-Comportamento Agonístico
Armas de Fogo/estatística & dados numéricos
Coleta de Dados
Delinquência Juvenil/estatística & dados numéricos
Delinquência Juvenil/tendências
Porto Rico
Assunção de Riscos
Problemas Sociais
Violência/legislação & jurisprudência
Violência/prevenção & controle
Limites: Humanos
Tipo de Publ: Estudo Comparativo
Responsável: BR1.1 - BIREME

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Id: lil-332926
Autor: Medina-Franco, Heriberto; Urist, Marshall M.
Título: Occult breast carcinoma presenting with axillary lymph node metastases
Fonte: Rev. invest. clín;54(3):204-208, mayo-jun. 2002.
Idioma: en.
Resumo: BACKGROUND AND OBJECTIVES: Occult primary breast carcinoma is uncommon. Most reported series encompass a large periods of time with great variability in diagnostic and treatment approaches. The objective of the present study was to review the recent experience with this type of presentation of breast cancer in the University of Alabama at Birmingham. METHODS: Retrospective review of clinicopathological data of female patients presenting with axillary metastasis of adenocarcinoma with unknown primary and normal clinical and mammographic breast exam seen at UAB between 1985 and 1998. RESULTS: Ten patients were identified. Mean age was 56 years. Sixty per cent were white and postmenopausal. All patients had biopsy proven adenocarcinoma consistent with breast primary. All but one patient underwent an axillary dissection. Nine out of ten patients received some type of local treatment to the breast. Three of them underwent mastectomy and no invasive carcinoma was demonstrated in the surgical specimens. Six patients received radiation therapy to the breast. All patients received chemotherapy. With mean follow-up time of 48 months, two patients developed local recurrence to the axilla and four developed distant metastasis and eventually died. At last follow-up six patients are alive with no evidence of disease. CONCLUSIONS: In presence of axillary metastasis from an unknown breast primary, an extensive work-up evaluation is not necessary. An axillary dissection is recommended to provide prognostic indicators as well as local control. A breast conservation approach seems to be feasible without affect the local control and survival.
Descritores: Adenocarcinoma
Neoplasias da Mama
Metástase Linfática
Metástase Linfática/diagnóstico
Neoplasias Primárias Desconhecidas/diagnóstico
Neoplasias da Mama
Terapia Combinada
Neoplasias Pulmonares
Excisão de Linfonodo
Neoplasias Ósseas/secundário
Neoplasias Primárias Desconhecidas/mortalidade
Estudos Retrospectivos
Tomografia Computadorizada por Raios X
Resultado do Tratamento
Limites: Adulto
Pessoa de Meia-Idade
Responsável: BR1.1 - BIREME

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Id: lil-212532
Autor: Villavicencio, Rafael E; Mancao, Mary; Carnahan, Gary.
Título: Plasmodium vivax infection in a child residing in Mobile, Alabama
Fonte: P. R. health sci. j;16(3):275-7, sept. 1997. ilus.
Idioma: en.
Resumo: A previously healthy 4-year old male, born in India and residing in Mobile, Alabama since October 1996 came to the emergency department in April 1997 because of general malaise, fever and vomits of 5 days duration. A peripheral smear of the complete blood count revealed the presence of malarial parasites within the erythrocytes. Plasmodium vivax was later identified in serial thin peripheral smears. He defervesced after initial treatment with oral quinine and pyrimethamine-sulfadoxine, followed by primaquine for 14 days.
Descritores: Malária Vivax
Malária Vivax/diagnóstico
Malária Vivax/tratamento farmacológico
Limites: Humanos
Tipo de Publ: Relatos de Casos
Responsável: BR1.1 - BIREME

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