RESUMEN
Cerrado is the second largest biome in Brazil, and it is responsible for providing us several ecosystem services, including the functions of storing Carbon and biodiversity conservation. In this study, we developed a modeling approach to predict the Aboveground biomass (AGB) in Cerrado vegetation using Artificial Neural Networks (ANNs), vegetation indices retrieved from RapidEye satellite imagery, and field data acquired within the Federal District territory, Brazil. Correlation testing was performed to identify potential vegetation index candidates to be used as input in the AGB modeling. Several ANNs were trained to predict the AGB in the study area using vegetation indices and field data. The optimum ANN was selected according to criteria of mean error of the estimate, correlation coefficient, and graphical analysis. The best performing ANN showed a predictive power of 90% and RMSE less than 17%. The validation tests showed no significant difference between the observed and ANN-predicted values. We estimated an average AGB of 16.55± 8.6 Mg.ha-1 in shrublands in the study area. Our study results indicate that vegetation indices and ANNs combined could accurately estimate the AGB in the Cerrado vegetation in the study area, showing to be a promising methodological approach to be broadly applied throughout the Cerrado biome.
Asunto(s)
Biomasa , Redes Neurales de la Computación , Tecnología de Sensores Remotos , Brasil , Ecosistema , Monitoreo del Ambiente/métodosRESUMEN
The Pacific oyster (Crassostrea gigas) is one of the world's most widespread bivalves and a suitable species for biomonitoring metals in coastal environments. In the present research, wild individuals were collected from an Argentinian estuary and the coastal beaches nearby. The concentrations of eight metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) were quantified in the soft tissues of the Pacific oyster. Among the metals, Cu, Fe and Zn reached the highest concentrations in the soft tissues over the rest of the elements. The results showed the highest values to be estuary related, with the beach site achieving the lowest values. These results possibly lie on the impact of human activities surrounding the estuary, as well as streams and rivers that outflow within it. Higher Cu and Zn levels, both port related, were mainly found toward the outer estuary. On the other hand, high levels of Cr, Fe and Mn were found toward the inner zone of the estuary, an area with sewage sludge from the cities located on the margins of the BBE. Regarding the potential risk to public health, Cu and Zn levels found in C. gigas were above national and international safety guidelines in 100% and 11% of the samples, respectively.
Asunto(s)
Crassostrea/química , Metales Pesados/análisis , Contaminantes Químicos del Agua/análisis , Animales , Monitoreo del Ambiente/métodos , Estuarios , Contaminación de Alimentos/análisis , Ríos , Mariscos/análisisRESUMEN
Cow raw milk cheese is widely eaten in Brazil. These products may be contaminated with pathogenic bacteria. In this work, we investigated the presence of Escherichia coli in raw milk cheese from different States in Brazil. From 147 "Minas" cheese samples, 28 cheeses were positive for E. coli. Among 39 E. coli isolates of the cheeses, one was positive for eae and negative for bpfA and efa1/lifA using PCR, and so was classified as atypical Enteropathogenic E. coli (aEPEC). Two other isolates were positive for extraintestinal pathogenic E. coli (ExPEC) genes. The aEPEC isolate belongs to serogroup O127 and was classified in A phylogenetic group, and ExPEC isolates were found in O73:H12 (EC-2 strain) and O64474:H8 (EC-9 strain) serotype. This ExPEC belongs to A and C phylogenetic group, respectively. Most of E. coli strains belonged to Clermont phylogenetic groups A (28.2%), C, and E (23.1%). Six strains (15.4%) of E. coli were positive for group B1 and two (5.1%) for B2. E. coli isolates presented an aggregative (46.0%) and diffuse (12.6%) adherence pattern to HeLa cells, and the other isolates did not show adhesion (41.4%). Four E. coli isolates (10.3%) were shown to produce moderate biofilm. The antimicrobial resistance rate was tetracycline (25.6%), followed by ampicillin (17.9%), cefoxitin (7.7%), nalidixic acid (5.1%), and amoxicillin-clavulanic acid (2.6%). One strain was resistant to three antimicrobials (tetracycline, ampicillin, and nalidixic acid). The presence of these microorganisms, the O127 strain, and a new serogroup in Brazil is a potential risk for public health.
Asunto(s)
Queso/microbiología , Farmacorresistencia Bacteriana Múltiple/genética , Escherichia coli Enteropatógena/genética , Leche/microbiología , Combinación Amoxicilina-Clavulanato de Potasio/farmacología , Ampicilina/farmacología , Animales , Antibacterianos/farmacología , Adhesión Bacteriana , Brasil , Cefoxitina/farmacología , ADN Bacteriano/genética , ADN Bacteriano/aislamiento & purificación , Escherichia coli Enteropatógena/efectos de los fármacos , Escherichia coli Enteropatógena/aislamiento & purificación , Contaminación de Alimentos , Microbiología de Alimentos , Células HeLa , Humanos , Pruebas de Sensibilidad Microbiana , Ácido Nalidíxico/farmacología , Pasteurización , Filogenia , Serogrupo , Serotipificación , Tetraciclina/farmacologíaRESUMEN
O propósito deste trabalho foi estudar a flutuação populacional de cigarrinhas em pormar cítrico em formação. A população de cigarrinhas foi monitorada usando-se armadilhas amarelas. A espécie mais abundante foi Bucephalogonia xanthophis (Berg). Baixas populações de Acrogonia sp., Dilobopterus costalimai Young e Oncometopia facialis (Signoret) foram detectadas durante o experimento.
The purpose of this research was to study the population fluctuation of sharpshooters in young citrus groves. The sharpshooters population was monitored using yellow stick traps. The most abundant species was Bucephalogonia xanthophis (Berg). Low populations of Acrogonia sp., Dilobopterus costalimai Young and Oncometopia facialis (Signoret) were detected throughout the trial.