Methodology for DSC calibration in high heating rates

Despite the large use of differential scanning calorimetry (DSC) technique in advanced polymer materials characterization, the new methodology called DSC in high heating rates was developed. The heating rate during conventional DSC experiments varying from 10 to 20°C.min-1, sample mass from 10 to 15mg and standard aluminum sample pan weighting, approximately, 27mg. In order to contribute to a better comprehension of DSC behavior in different heating rates, this work correlates as high heating rate influences to the thermal events in DSC experiments. Samples of metallic standard (In, Pb, Sn and Zn) with masses varying from 0.570mg to 20.9mg were analyzed in multiples sample heating rate from 4 to 324°C. min-1. In order to make properly all those experiments, a precise and careful temperature and enthalpy calibrations were performed and deeply discussed. Thus, this work shows a DSC methodology able to generate good and reliable results on experiments under any researcher choice heating rates to characterize the advanced materials used, for example, for aerospace industry. Also it helps the DSC users to find in their available instruments, already installed, a better and more accurate DSC test results, improving in just one shot the analysis sensitivity and resolution. Polypropylene melting and enthalpy thermal events are also studied using both the conventional DSC method and high heating rate method.

Import substitution in high-tech industries: Prebisch lives in Asia!

Includes bibliography

Informe del Seminario Regional sobre Políticas Agrarias y Sobrevivencia Campesina en Ecosistemas de Altura = Report of the Regional Seminar on Agrarian Policies and Peasant Survival in High-Altitude Ecosystems

Conclusiones y recomendaciones del Seminario cuyo objetivo fue analizar los problemas del campesinado andino en ecosistemas de altura relacionados con la penetración del estilo de desarrollo predominante en Latinoamérica, resaltando los complejos influjos recíprocos entre la oferta ambiental de recursos, las particularidades de los distintos pisos ecológicos, las formas y sistemas de organización social, los cambios y tendencias de la situación ambiental, para recomendar políticas de desarrollo que sean opciones viables para resolver los problemas del campesino de esas áreas. Incluye lista de participantes y documentos presentados.

Metabolic profile response to administration of epigallocatechin-3-gallate in high-fat-fed mice

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Isosinglet neutral heavy lepton production in high energy e-γ collisions

We evaluate the potential for searching for isosinglet neutral heavy leptons (N), such as right-handed neutrinos, in the next generation of e+e- linear colliders, paying special attention to contributions from the reaction γe→WN initiated by photons from beamstrahlung and laser back-scattering. We find that these mechanisms are both competitive and complementary to the standard e+e-→vN annihilation process for producing neutral heavy leptons in these machines and greatly extends the search range over HERA and LEP200.

Sexual haressement in dentistry: prevalence in dental school

OBJECTIVE: Sexual harassment is unlawful in all work and educational environments in most nations of the world. The goals of this study were to describe the sexual harassment prevalence and to evaluate the experiences and attitudes of undergraduate students in one dental school in Brazil. MATERIAL AND METHODS: An 18-item questionnaire was administered to 254 dental students with a completion rate of 82% (208). Students were requested to respond to questions about their background and academic level in dental school, their personal experiences with sexual harassment and their observation of someone else being sexually harassed. Bivariate statistical analyses were performed. RESULTS: Fifteen percent of the students reported being sexually harassed by a patient, by a relative of a patient or by a professor. Male students had 3 times higher probability of being sexually harassed than female student [OR=2.910 (1.113-7.611)]. Additionally, 25.4% of the students reported witnessing sexual harassment at the school environment. The majority of students did not feel professionally prepared to respond to unwanted sexual behaviors. CONCLUSION: These findings demonstrate that sexual harassment can occur in a dental school setting. There is a need for ongoing sexual harassment education programs for students and university staff. Increased knowledge of sexual harassment during graduation can better prepare dental professionals to respond to sexual harassment during their practice.

The interactive whiteboard in primary school: a case study of a brazilian district school

Interactive whiteboards (IWB) consist of a set of technological equipment organized in order to fulfill a specific task, enabling the development of didactic activities. Because they are associated to computers’ potentiality, interactive whiteboards can provide bigger interactivity between: teacher and students, students and content, and among students. This work’s main objective is to present some of the results yielded from a research related to the way students perceive interactive whiteboards in the classroom. In order to analyze the IWB usage dynamics, some educational applications in the field of mathematics were applied in the 3rd grade of elementary school. Aside from observation, video recordings were made and students were interviewed about the interactive whiteboard, in order to understand how these students observe and engage with the technological tool. IWB do not transform classroom’s reality by themselves, however, their physical presence and usage amount to external reinforcement can change student’s behavior positively.

The canonical correlation between the biological markers of performance and physical fitness in high level judo athletes

The objective of this research was to verify the relationship between biological markers of performance of elite judo athletes and performance in different physical fitness tests. Twenty-one judo athletes were involved in the present observational and correlational study. Dermatoglyphic variables and the 2D:4D digit ratio were considered as biological markers, while the physical fitness variables analyzed were body fat, maximal strength, muscular power, the aerobic and anaerobic profile, and performance in specific tests. The statistics involved canonical correlations and a multivariate technique. A high and significant canonical correlation was observed between groups of variables, the first expressed by 1=0.999 (p<0.0001) and the second by 2=0.997 (p<0.001). It appears that, beyond height and body mass, total ridge count, pattern intensity for fingers and 2D:4D had more canonical loading. The physical fitness component of the first canonical variable incorporated, with high intensity were: the sum of skinfold thickness, the bench press onerepetition maximum (1RM), upper and lower body aerobic power. In the second canonical variable, physical fitness was composed of the squat 1RM, suspension time on the bar, the SJFT-index, and mean power during the upper body Wingate test. The data of this investigation showed the interdependence between biological markers of performance and physical fitness in high level judo athletes.

Is Competition Making a Comeback? Discovering Methods to Keep Female Adolescents Engaged in STEM: A Phenomenological Approach

The decreasing number of women who are graduating in the Science, Technology, Engineering and Mathematics (STEM) fields continues to be a major concern. Despite national support in the form of grants provided by National Science Foundation, National Center for Information and Technology and legislation passed such as the Deficit Reduction Act of 2005 that encourages women to enter the STEM fields, the number of women actually graduating in these fields is surprisingly low. This research study focuses on a robotics competition and its ability to engage female adolescents in STEM curricula. Data have been collected to help explain why young women are reticent to take technology or engineering type courses in high school and college. Factors that have been described include attitudes, parental support, social aspects, peer pressure, and lack of role models. Often these courses were thought to have masculine and “nerdy” overtones. The courses were usually majority male enrollments and appeared to be very competitive. With more female adolescents engaging in this type of competitive atmosphere, this study gathered information to discover what about the competition appealed to these young women. Focus groups were used to gather information from adolescent females who were participating in the First Lego League (FLL) and CEENBoT competitions. What enticed them to participate in a curriculum that data demonstrated many of their peers avoided? FLL and CEENBoT are robotics programs based on curricula that are taught in afterschool programs in non-formal environments. These programs culminate in a very large robotics competition. My research questions included: What are the factors that encouraged participants to participate in the robotics competition? What was the original enticement to the FLL and CEENBoT programs? What will make participants want to come back and what are the participants’ plans for the future? My research mirrored data of previous findings such as lack of role models, the need for parental support, social stigmatisms and peer pressure are still major factors that determine whether adolescent females seek out STEM activities. An interesting finding, which was an exception to previous findings, was these female adolescents enjoyed the challenge of the competition. The informal learning environments encouraged an atmosphere of social engagement and cooperative learning. Many volunteers that led the afterschool programs were women (role models) and a majority of parents showed support by accommodating an afterschool situation. The young women that were engaged in the competition noted it was a friendly competition, but they were all there to win. All who participated in the competition had a similar learning environment: competitive but cooperative. Further research is needed to determine if it is the learning environment that lures adolescent females to the program and entices them to continue in the STEM fields or if it is the competitive aspect of the culminating activity. Advisors: James King and Allen Steckelberg

Does group size matter? Cheating and cooperation in Brazilian school children

Cooperation between individuals is an important requisite for the maintenance of social relationships. The purpose of this study was to investigate cooperation in children in the school environment, where individuals could cooperate or not with their classmates in a public goods game. We investigated which of the following variables influenced cooperation in children: sex, group size, and information on the number of sessions. Group size was the only factor to significantly affect cooperation, with small-group children cooperating significantly more than those in large groups. Both sex and information had no effect on cooperation. We suggest that these results reflect the fact that, in small groups, individuals were more efficient in controlling and retaliating theirs peers than in large groups. (C) 2008 Elsevier Inc. All rights reserved.

Pentraxin 3 accelerates lung injury in high tidal volume ventilation in mice

Mechanical ventilation is the major cause of iatrogenic lung damage in intensive care units. Although inflammation is known to be involved in ventilator-induced lung injury (VILI), several aspects of this process are still unknown. Pentraxin 3 (PTX3) is an acute phase protein with important regulatory functions in inflammation which has been found elevated in patients with acute respiratory distress syndrome. This study aimed at investigating the direct effect of PTX3 production in the pathogenesis of VILI. Genetically modified mice deficient and that over express murine Ptx3 gene were subjected to high tidal volume ventilation (V-T = 45 mL/kg, PEEPzero). Morphological changes and time required for 50% increase in respiratory system elastance were evaluated. Gene expression profile in the lungs was also investigated in earlier times in Ptx3-overexpressing mice. Ptx3 knockout and wild-type mice developed same lung injury degree in similar times (156 +/- 42 min and 148 +/- 41 min, respectively: p = 0.8173). However, Ptx3 overexpression led to a faster development of VILI in Ptx3-overexpressing mice (77 +/- 29 min vs 118 +/- 41 min, p = 0.0225) which also displayed a faster kinetics of Il1b expression and elevated Ptx3, Cxcl1 and Ccl2 transcripts levels in comparison with wild-type mice assessed by quantitative real-time polymerase chain reaction. Ptx3 deficiency did not impacted the time for VILI induced by high tidal volume ventilation but Ptx3-overexpression increased inflammatory response and reflected in a faster VILI development. (C) 2012 Elsevier Ltd. All rights reserved.

Maternal obesity in high-risk pregnancies and postpartum infectious complications

Objective: To analyze the association between maternal obesity and postnatal infectious complications in high-risk pregnancies. Methods: Prospective study from August 2009 through August 2010 with the following inclusion criteria: women up to the 5th postpartum day; age L 18 years; high-risk pregnancy; singleton pregnancy with live fetus at labor onset; delivery at the institution; maternal weight measured on day of delivery. The nutritional status in late pregnancy was assessed by the body mass index (BMI), with the application of the Atalah et al. curve. Patients were graded as underweight, adequate weight, overweight, or obese. Postpartum complications investigated during the hospital stay and 30 days post-discharge were: surgical wound infection and/or secretion, urinary infection, postpartum infection, fever, hospitalization, antibiotic use, and composite morbidity (at least one of the complications mentioned). Results: 374 puerperal women were included, graded according to the final BMI as: underweight (n = 54, 14.4%); adequate weight (n = 126, 33.7%); overweight (n = 105, 28.1%); and obese (n = 89, 23.8%). Maternal obesity was shown to have a significant association with the following postpartum complications: surgical wound infection (16.7%, p = 0.042), urinary infection (9.0%, p = 0.004), antibiotic use (12.3%, p < 0.001), and composite morbidity (25.6%, p = 0.016). By applying the logistic regression model, obesity in late pregnancy was found to be an independent variable regardless of the composite morbidity predicted (OR: 2.09; 95% CI: 1.15-3.80, p = 0.015). Conclusion: Maternal obesity during late pregnancy in high-risk patients is independently associated with postpartum infectious complications, which demonstrates the need for a closer follow-up of maternal weight gain in these pregnancies.

Abrupt changes in high-latitude nutrient supply to the Atlantic during the last glacial cycle

The supply of nutrients to the low-latitude thermocline is largely controlled by intermediate-depth waters formed at the surface in the high southern latitudes. Silicic acid is an essential macronutrient for diatoms, which are responsible for a significant portion of marine carbon export production. Changes in ocean circulation, such as those observed during the last deglaciation, would influence the nutrient composition of the thermocline and, therefore, the relative abundance of diatoms in the low latitudes. Here we present the first record of the silicic acid content of the Atlantic over the last glacial cycle. Our results show that at intermediate depths of the South Atlantic, the silicic acid concentration was the same at the Last Glacial Maximum (LGM) as it is today, overprinted by high silicic acid pulses that coincided with abrupt changes in ocean and atmospheric circulation during Heinrich Stadials and the Younger Dryas. We suggest these pulses were caused by changes in intermediate water formation resulting from shifts in the subpolar hydrological cycle, with fundamental implications for the nutrient supply to the Atlantic.

Tributyrin attenuates obesity-associated inflammation and insulin resistance in high-fat-fed mice

Vinolo MA, Rodrigues HG, Festuccia WT, Crisma AR, Alves VS, Martins AR, Amaral CL, Fiamoncini J, Hirabara SM, Sato FT, Fock RA, Malheiros G, dos Santos MF, Curi R. Tributyrin attenuates obesity-associated inflammation and insulin resistance in high-fat-fed mice. Am J Physiol Endocrinol Metab 303: E272-E282, 2012. First published May 22, 2012; doi:10.1152/ajpendo.00053.2012.-The aim of this study was to investigate whether treatment with tributyrin (Tb; a butyrate prodrug) results in protection against diet-induced obesity and associated insulin resistance. C57BL/6 male mice fed a standard chow or high-fat diet were treated with Tb (2 g/kg body wt, 10 wk) and evaluated for glucose homeostasis, plasma lipid profile, and inflammatory status. Tb protected mice against obesity and obesity-associated insulin resistance and dyslipidemia without food consumption being affected. Tb attenuated the production of TNF alpha and IL-1 beta by peritoneal macrophages and their expression in adipose tissue. Furthermore, in the adipose tissue, Tb reduced the expression of MCP-1 and infiltration by leukocytes and restored the production of adiponectin. These effects were associated with a partial reversion of hepatic steatosis, reduction in liver and skeletal muscle content of phosphorylated JNK, and an improvement in muscle insulin-stimulated glucose uptake and Akt signaling. Although part of the beneficial effects of Tb are likely to be secondary to the reduction in body weight, we also found direct protective actions of butyrate reducing TNF alpha production after LPS injection and in vitro by LPS- or palmitic acid-stimulated macrophages and attenuating lipolysis in vitro and in vivo. The results, reported herein, suggest that Tb may be useful for the treatment and prevention of obesity-related metabolic disorders.