Universidade Federal de Santa Catarina

About: Universidade Federal de Santa Catarina is a education organization based out in Florianópolis, Brazil. It is known for research contribution in the topics: Population & Context (language use). The organization has 28408 authors who have published 55433 publications receiving 714461 citations.

Fish antioxidant defenses--a comparative approach

Abstract: There are few comparative studies of vertebrate antioxidant defenses (AD) in the literature Enzymatic (superoxide dismutase, SOD, and catalase, CAT) and non-enzymatic (alpha-tocopherol, beta-carotene, ubiquinol 10 and blood glutathione) antioxidant defenses were investigated in the liver and blood of 37 fish species, 15 marine species of the southeastern Brazilian coast and 22 freshwater species from the Central Amazon basin More active marine species displayed in general higher concentrations of SOD and CAT in the liver and blood, compared to those of sedentary or bottom-dwelling species AD status in marine fish m ay be related to the oxygen consumption of the tissues and of the whole organism, while in freshwater AD may be related to physical and chemical characteristics of the environment rather than to activity level As thermoconformer organisms, most fish must routinely cope with environmental temperature changes and, consequently, with changes in their metabolic rates The relatively high antioxidant defense levels that typify fishes, even when compared to endotherms such as birds and mammals, may protect aquatic organisms against the consequences of temperature oscillations

Seaweeds: an opportunity for wealth and sustainable livelihood for coastal communities

Abstract: The European, Canadian, and Latin American seaweed industries rely on the sustainable harvesting of natural resources. As several countries wish to increase their activity, the harvest should be managed according to integrated and participatory governance regimes to ensure production within a long-term perspective. Development of regulations and directives enabling the sustainable exploitation of natural resources must therefore be brought to the national and international political agenda in order to ensure environmental, social, and economic values in the coastal areas around the world. In Europe, Portugal requires an appraisal of seaweed management plans while Norway and Canada have developed and implemented coastal management plans including well-established and sustainable exploitation of their natural seaweed resources. Whereas, in Latin America, different scenarios of seaweed exploitation can be observed; each country is however in need of long-term and ecosystem-based management plans to ensure that exploitation is sustainable. These plans are required particularly in Peru and Brazil, while Chile has succeeded in establishing a sustainable seaweed-harvesting plan for most of the economically important seaweeds. Furthermore, in both Europe and Latin America, seaweed aquaculture is at its infancy and development will have to overcome numerous challenges at different levels (i.e., technology, biology, policy). Thus, there is a need for regulations and establishment of “best practices” for seaweed harvesting, management, and cultivation. Trained human resources will also be required to provide information and education to the communities involved, to enable seaweed utilization to become a profitable business and provide better income opportunities to coastal communities.

Generation of a family of non-isolated DC-DC PWM converters using new three-state switching cells

Abstract: This paper introduces a new family of PWM DC-DC nonisolated converters. The new converters are generated using three-state commutation cells, comprising two active switches, two diodes and coupled inductors. The main advantages over the classical converters are low conduction and commutation losses, and low input and output current ripple. Due to these features, the new converters are suitable for low voltage and high current applications. Theoretical analysis and experimentation results are presented.

Comment on “The global tree restoration potential”

Abstract: Bastin et al.’s estimate (Reports, 5 July 2019, p. 76) that tree planting for climate change mitigation could sequester 205 gigatonnes of carbon is approximately five times too large. Their analysis inflated soil organic carbon gains, failed to safeguard against warming from trees at high latitudes and elevations, and considered afforestation of savannas, grasslands, and shrublands to be restoration.

Birth in Brazil: national survey into labour and birth

Abstract: Background: Caesarean section rates in Brazil have been steadily increasing. In 2009, for the first time, the number of children born by this type of procedure was greater than the number of vaginal births. Caesarean section is associated with a series of adverse effects on the women and newborn, and recent evidence suggests that the increasing rates of prematurity and low birth weight in Brazil are associated to the increasing rates of Caesarean section and labour induction. Methods: Nationwide hospital-based cohort study of postnatal women and their offspring with follow-up at 45 to 60 days after birth. The sample was stratified by geographic macro-region, type of the municipality and by type of hospital governance. The number of postnatal women sampled was 23,940, distributed in 191 municipalities throughout Brazil. Two electronic questionnaires were applied to the postnatal women, one baseline face-to-face and one follow-up telephone interview. Two other questionnaires were filled with information on patients’ medical records and to assess hospital facilities. The primary outcome was the percentage of Caesarean sections (total, elective and according to Robson’s groups). Secondary outcomes were: post-partum pain; breastfeeding initiation; severe/near miss maternal morbidity; reasons for maternal mortality; prematurity; low birth weight; use of oxygen use after birth and mechanical ventilation; admission to neonatal ICU; stillbirths; neonatal mortality; readmission in hospital; use of surfactant; asphyxia; severe/near miss neonatal morbidity. The association between variables were investigated using bivariate, stratified and multivariate model analyses. Statistical tests were applied according to data distribution and homogeneity of variances of groups to be compared. All analyses were taken into consideration for the complex sample design. Discussion: This study, for the first time, depicts a national panorama of labour and birth outcomes in Brazil. Regardless of the socioeconomic level, demand for Caesarean section appears to be based on the belief that the quality of obstetric care is closely associated to the technology used in labour and birth. Within this context, it was justified to conduct a nationwide study to understand the reasons that lead pregnant women to submit to Caesarean sections and to verify any association between this type of birth and it’s consequences on postnatal health.