Browsing by Author "Araujo Palharini, Rayana Santos"

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    Evaluation of the Integrated Multi-SatellitE Retrievals for the Global Precipitation Measurement (IMERG) Product in the Sao Francisco Basin (Brazil)
    (2021) Rodrigues, Daniele Torres; Santos e Silva, Claudio Moises; dos Reis, Jean Souza; Araujo Palharini, Rayana Santos; Cabral Junior, Jorio Bezerra; Farias da Silva, Helder Jose; Mutti, Pedro Rodrigues; Bezerra, Bergson Guedes; Goncalves, Weber Andrade
    The Sao Francisco River basin is one of the largest in the Brazilian territory. This basin has enormous economic, social and cultural importance for the country. Its water is used for human and animal supply, irrigation and energy production. This basin is located in an area with different climatic characteristics (humid and semiarid) and studies related to precipitation are very important in this region. In this scenario, the objective of this investigation is to present an assessment of rainfall estimated through the Integrated Multi-SatellitE Retrievals for Global Precipitation Measurement (IMERG) product compared with rain gauges over the Sao Francisco river basin in Brazil. For that, a period from of 20 years and 18 surface weather stations were used to evaluate the product. Based on different evaluation techniques, the study found that the IMERG is appropriate to represent precipitation over the basin. According to the results, the performance of the IMERG product depends on the location where the rain occurs. The bias ranged from -1.67 to 0.34 mm, the RMSE ranged from 5.36 to 10.36 mm and the values of the correlation coefficients between the daily data from the IMERG and rain gauge ranged from 0.28 to 0.61. The results obtained by Student t-test, density curves and regression analysis, in general, show that the IMERG is able to satisfactorily represent rain gauge data. The exception is the eastern portion of the basin, where the product, on average, underestimates the precipitation (p-value < 0.05) and presents the worst statistical metrics.
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    Prevalence and Distribution of Salmonella in Water Bodies in South America: A Systematic Review
    (2025) González Reyes, Makarena Sofia; Araujo Palharini, Rayana Santos; Ferreira Monteiro, Felipe; Ayala, Salvador; Undurraga Fourcade, Eduardo Andrés
    The presence of Salmonella in rivers, lakes, or beaches in South America represents a challenge to public health and aquatic ecosystems. This review explores the distribution, prevalence, and the main factors contributing to the survival and spread of Salmonella, including wastewater discharge, agricultural runoff, and climatic variables such as high temperatures and precipitation. These factors also facilitate the distribution of multidrug-resistant strains in water. The review is based on bibliographic searches in various databases, focusing on Salmonella species, South American countries, and types of water bodies. Predominant serovars include S. Enteritidis and S. Typhimurium, with S. Typhi and S. Panama frequently detected in Chile, S. Enteritidis in Argentina, and S. Typhimurium in Brazil. Less common serovars, including S. Dublin and S. Paratyphi B, were identified, along with subspecies such as diarizonae and houtenae. These findings highlight the role of environmental, physicochemical, and anthropogenic factors influencing Salmonella dynamics. The review identifies research gaps, advocating for further studies to better understand the interactions between Salmonella, climate change, and human activity. Strengthening surveillance and mitigation strategies is crucial to protect water resources and public health in South America.