Herbicides in the upper Poxim River, Sergipe, and the risk of contamination of water resources

Increased agricultural activity in watershed areas has been causing concern over contamination by herbicides in agricultural areas. The problem becomes more important when contamination can affect water for human consumption, as happens with water from the Poxim river, which supplies the city of Aracaju, capital of the State of Sergipe. The aim of this study was to evaluate the risk of contamination by herbicides to both surface and groundwater in the upper sub-basin of the Poxim River, and to detect the presence of the active ingredients Diuron and Ametrine up-river from the sugar-cane plantations. Risk analysis was carried out using criteria from the Environmental Protection Agency (EPA), the GUS index, and the GOSS method. It was observed that several active ingredients are at risk of leaching, demonstrating the importance of monitoring the river to control both the quality of water and the frequency and volume of herbicides used in the region. Based on the results, monitoring was carried out bi-monthly from July 2009 to July 2010 at two sampling points. Water samples were analyzed in the laboratory, where the presence of Diuron and Ametrine was noted. Water quality in the Sub-basin of the Rio Poxim is being influenced by the use of herbicides in the region. There was an increase in herbicide concentration in the surface water during the rainy season, possibly caused by soil runoff.

INFLUENZA VIRUSES IN ADULT DOGS RAISED IN RURAL AND URBAN AREAS IN THE STATE OF SAO PAULO, BRAZIL

In 1970, searching for the interspecies transmission of influenza viruses led to the first study on influenza viruses in domestic animals. Birds and mammals, including human beings, are their natural hosts; however, other animals may also play a role in the virus epidemiology. The objective was to investigate the incidence of influenza viruses in adult dogs raised in rural (9, 19.56%) and urban (37, 80.43%) areas in the state of Sao Paulo, Brazil. Dog serum samples were examined for antibodies to influenza viruses by the hemagglutination inhibition (HI) test using the corresponding antigens from the circulating viruses in Brazil. Dogs from rural areas presented antibodies to influenza A H3N2, and influenza A H7N7 and H3N8. In rural areas, dog sera displayed mean titers as 94.37, 227.88, 168.14, 189.62 HIU/25 mu L for subtypes H1N1, H3N2, H7N7, H3N8, respectively. About 84% and 92% of dogs from urban areas exhibited antibodies to human influenza A H1N1 and H3N2, respectively, with statistical difference at p < 0.05 between the mean titers of antibodies to H1N1 and H3N2. About 92% and 100% were positive for H7N7 and H3N8, respectively. In dogs from urban areas, the mean titers of antibodies against influenza A H1N1, H3N2, H7N7 and H3N8, were 213.96, 179.42, 231.76, 231.35 HIU/25 mu L respectively. The difference among them was not statistically significant at p > 0.05. In conclusion, these dogs were positive for both human and equine influenza viruses. The present study suggests the first evidence that influenza viruses circulate among dogs in Brazil.

Computational and experimental characterization of a low-cost piezoelectric valveless diaphragm pump

Flow pumps act as important devices in areas such as Bioengineering, Medicine, and Pharmacy, among other areas of Engineering, mainly for delivering liquids or gases at small-scale and precision flow rate quantities. Principles for pumping fluids based on piezoelectric actuators have been widely studied, since they allow the construction of pump systems for displacement of small fluid volumes with low power consumption. This work studies valveless piezoelectric diaphragm pumps for flow generation, which uses a piezoelectric ceramic (PZT) as actuator to move a membrane (diaphragm) up and down as a piston. The direction of the flow is guaranteed by valveless configuration based on a nozzle-diffuser system that privileges the flow in just one pumping direction. Most research efforts on development of valveless flow pump deal either with computational simulations based on simplified models or with simplified physical approaches based on analytical models. The main objective of this work is the study of a methodology to develop a low-cost valveless piezoelectric diaphragm flow pump using computational simulations, parametric study, prototype manufacturing, and experimental characterization. The parametric study has shown that the eccentricity of PZT layer and metal layer plays a key role in the performance of the pump.

Experimental model of tooth movement in mice: A standardized protocol for studying bone remodeling under compression and tensile strains

During orthodontic tooth movement (OTM), alveolar bone is resorbed by osteoclasts in compression sites (CS) and is deposited by osteoblasts in tension sites (TS). The aim of this study was to develop a standardized OTM protocol in mice and to investigate the expression of bone resorption and deposition markers in CS and TS. An orthodontic appliance was placed in C57BL6/J mice. To define the ideal orthodontic force, the molars of the mice were subjected to forces of 0.1 N, 0.25 N, 0.35 N and 0.5 N. The expression of mediators that are involved in bone remodeling at CS and TS was analyzed using a Real-Time PCR. The data revealed that a force of 0.35 N promoted optimal OTM and osteoclast recruitment without root resorption. The levels of TNF-alpha, RANKL, MMP13 and OPG were all altered in CS and TS. Whereas TNF-a and Cathepsin K exhibited elevated levels in CS. RUNX2 and OCN levels were higher in TS. Our results suggest that 0.35 N is the ideal force for OTM in mice and has no side effects. Moreover, the expression of bone remodeling markers differed between the compression and the tension areas, potentially explaining the distinct cellular migration and differentiation patterns in each of these sites. (C) 2012 Elsevier Ltd. All rights reserved.

17 beta-Estradiol replacement in young, adult and middle-aged female ovariectomized rats promotes improvement of spatial reference memory and an antidepressant effect and alters monoamines and BDNF levels in memory- and depression-related brain areas

Clinical and experimental evidence suggest that estrogens have a major impact on cognition, presenting neurotrophic and neuroprotective actions in regions involved in such function. In opposite, some studies indicate that certain hormone therapy regimens may provoke detrimental effects over female cognitive and neurological function. Therefore, we decided to investigate how estrogen treatment would influence cognition and depression in different ages. For that matter, this study assessed the effects of chronic 17 beta-estradiol treatment over cognition and depressive-like behaviors of young (3 months old), adult (7 months old) and middle-aged (12 months old) reproductive female Wistar rats. These functions were also correlated with alterations in the serotonergic system, as well as hippocampal BDNF. 17 beta-Estradiol treatment did not influence animals' locomotor activity and exploratory behavior, but it was able to improve the performance of adult and middle-aged rats in the Morris water maze, the latter being more responsive to the treatment. Young and adult rats displayed decreased immobility time in the forced swimming test, suggesting an effect of 17 beta-estradiol also over such depressive-like behavior. This same test revealed increased swimming behavior, triggered by serotonergic pathway, in adult rats. Neurochemical evaluations indicated that 17 beta-estradiol treatment was able to increase serotonin turnover rate in the hippocampus of adult rats. Interestingly, estrogen treatment increased BDNF levels from animals of all ages. These findings support the notion that the beneficial effects of 17 beta-estradiol over spatial reference memory and depressive-like behavior are evident only when hormone therapy occurs at early ages and early stages of hormonal decline. (C) 2011 Elsevier B.V. All rights reserved.

The double task of preventing malnutrition and overweight: a quasi-experimental community-based trial

Background: The Maternal-Child Pastoral is a volunteer-based community organization of the Dominican Republic that works with families to improve child survival and development. A program that promotes key practices of maternal and child care through meetings with pregnant women and home visits to promote child growth and development was designed and implemented. This study aims to evaluate the impact of the program on nutritional status indicators of children in the first two years of age. Methods: A quasi-experimental design was used, with groups paired according to a socioeconomic index, comparing eight geographical areas of intervention with eight control areas. The intervention was carried out by lay health volunteers. Mothers in the intervention areas received home visits each month and participated in a group activity held biweekly during pregnancy and monthly after birth. The primary outcomes were length and body mass index for age. Statistical analyses were based on linear and logistic regression models. Results: 196 children in the intervention group and 263 in the control group were evaluated. The intervention did not show statistically significant effects on length, but point estimates found were in the desired direction: mean difference 0.21 (95%CI −0.02; 0.44) for length-for-age Z-score and OR 0.50 (95%CI 0.22; 1.10) for stunting. Significant reductions of BMI-for-age Z-score (−0.31, 95%CI −0.49; -0.12) and of BMI-for-age > 85th percentile (0.43, 95%CI 0.23; 0.77) were observed. The intervention showed positive effects in some indicators of intermediary factors such as growth monitoring, health promotion activities, micronutrient supplementation, exclusive breastfeeding and complementary feeding. Conclusions: Despite finding effect measures pointing to effects in the desired direction related to malnutrition, we could only detect a reduction in the risk of overweight attributable to the intervention. The findings related to obesity prevention may be of interest in the context of the nutritional transition. Given the size of this study, the results are encouraging and we believe a larger study is warranted.