Thermal-biological aspects on the seed germination of Cucumis anguria L.: influence of the seed coat

The seed coat influences the early stages of germination of many seeds and sometimes maintains seed dormancy. Early reports have shown that the testa influences the germination response of Cucumis anguria seeds to light although the response to temperature as influenced by the tegument is not well understood. The main purpose of this study was to observe the influence of the testa on the germination of Cucumis anguria by using parameters as germinability and isothermal germination rate. The assays were carried out in a thermal-gradient block with water imbibed seeds kept in darkness. Estimates of the activation enthalpies (deltaH) show |deltaH| < 50 kJ.mol-1 between 26.1 °C and 35.2 °C (intact seeds) and between 25.4 °C and 35.2 °C (scarified seeds), whereas at temperatures greater than 35.2 °C the germination may be limited by processes with |deltaH| > 125 kJ.mol-1. It is suggested that the testa limits embryo expansion rather than interfering with diffusion processes.

Thermal biology, activity, and population parameters of Cnemidophorus vacariensis (Squamata, Teiidae), a lizard endemic to southern Brazil

We investigated the following aspects of the biology of a population of Cnemidophorus vacariensis Feltrim & Lema, 2000 during the four seasons: thermal biology, relationship with the thermal environment, daily and seasonal activity, population structure and growth rate. Cnemidophorus vacariensis is restricted to rocky outcrops of the "campos de cima da serra" grasslands on the Araucaria Plateau, southern Brazil, and is currently listed as regionally and nationally threatened with extinction. Data were collected from October 2004 through September 2007 in the state of Rio Grande do Sul. Sampling was conducted randomly from 08:00 a.m. to 6:00 p.m. The capture-mark-recapture method was employed. The lizards were captured by hand, and their cloacal temperature, sex, snout-ventral length (SVL), mass, and the temperature of their microhabitat (substrate temperature and air temperature) were recorded. Individuals were then marked by toe-clipping and released at the site of capture. Body temperatures were obtained for 175 individuals, activity data for 96 individuals, and data on population structure and growth for 59 individuals. All data were obtained monthly, at different times of the day. Cnemidophorus vacariensis average body temperature was 23.84ºC, ranging between 9.6 and 38.2ºC. Temperatures ranged between 21 and 29ºC. The correlation between external heat sources, substrate and air were positive and significant and there was a greater correlation between lizard's temperature and the temperature of the substrate (tigmothermic species). The relatively low body temperatures of individuals are associated with the climate of their environment (altitude up to 1,400 m), with large variations in temperature throughout the day and the year, and low temperatures in winter. The average body temperature observed for C. vacariensis was low when compared with that of phylogenetically related species, suggesting that the thermal biology of this species reflects adaptations to the temperate region where it lives. The monthly rates of activity of lizards were related to monthly variations in the ambient temperatures. Our data suggest that the daily and seasonal activity of C. vacariensis result from the interaction between two factors: changes in the environment temperature and the relationship between individuals and their thermal environment. The population structure of C. vacariensis varied throughout the study period, with maximum biomass in January and maximum density in February (recruitment period). The sex ratio diverged from the expected 1:1. The growth analysis showed a negative relationship between the growth rate of individuals and the SVL, revealing that young individuals grow faster than adults, a typical pattern for short-lived species. The population studied showed a seasonal and cyclical variation associated with the reproductive cycle. The life strategy of C. vacariensis seems to include adaptations to the seasonal variations in temperature, typical of its environment.

A new approach to evaluate immobilization of β-galactosidase on Eupergit® C: structural, kinetic, and thermal characterization

This study aimed to evaluate β-galactosidase immobilization. For this purpose, the ionic strength of the buffer, reaction time, amount of the immobilization support, and pH were evaluated by a central composite design. Assay 8, which consisted of 1.5 mol L-1 phosphate buffer (pH 7.5) and a reaction time of 2 h, produced the maximum yield. Eupergit® C (400 mg) was subsequently used as an immobilization support. Immobilization kinetics wereinvestigated, and a significant increase in the yield was obtained after immobilization compared with that obtained from assay 8 (22.0 U mL-1 vs. 15.6 U mL-1). The enzyme efficiency of actuation was evaluated using o-nitrophenyl-β-D-galactopyranoside and lactose, with lactose providing better results. The reuse of β-galactosidase was evaluated, and more than 50% of the initial enzyme activity was maintained after five cycles of use. Enzyme characterization revealed that immobilization improved some aspects of the thermostability of β-galactosidase.

An overview of domestic aspects in US climate policy

The article shows how domestic aspects influence the United States national and international climate policy. To accomplish the task, the authors analyzes the discussions when Bill Clinton was ruling the country, a time during which global discussions were forwarded. The paper recalls the debate in the Bush administration and the growing polarization since Barack Obama took office.

Chemical, morphological, rheological and thermal properties of Solanum lycocarpum phosphorylated starches

The increasing need for starches with specific characteristics makes it important to study unconventional starches and their modifications in order to meet consumer demands. The aim of this work was to study physicochemical characteristics of native starch and phosphate starch of S. lycocarpum. Native starch was phosphated with sodium tripolyphosphate (5-11%) added with stirring. Chemical composition, morphology, density, binding ability to cold water, swelling power and solubility index, turbidity and syneresis, rheological and calorimetric properties were determined. Phosphorus was not detected in the native sample, but the phosphating process produced modified starches with phosphorus contents of 0.015, 0.092 and 0.397%, with the capacity of absorbing more water, either cold or hot. Rheological data showed the strong influence of phosphorus content on viscosity of phosphate starch, with lower pasting temperature and peak viscosity higher than those of native starch. Enthalpy was negatively correlated with the phosphorus content, requiring 9.7; 8.5; 8.1 and 6.4 kJ g-1 of energy for the transition from the amorphous to the crystalline state for the starch granules with phosphorus contents of 0; 0.015; 0.092 and 0.397%, respectively. Cluster analysis and principal component analysis showed that starches with 0.015 and 0.092% phosphorus have similar characteristics and are different from the others. Our results show that the characteristics of phosphate modified S. lycocarpum starch have optimal conditions to meet the demands of raw materials, which require greater consistency in stickiness, combined with low rates of retrogradation and syneresis.

Some aspects of implementing Regulatory Impact Analysis in Brazil

In an increasingly complex society, regulatory polices emerge as an important tool in public management. Nevertheless, regulation per se is no longer enough, and the agenda for a regulatory reform is increasing. Following this context, Brazil has implemented Regulatory Impact Analysis (RIA) in its regulatory agencies. Thus, Brazilian specificities have to be considered and, in this regard, a systematic approach provides a significant contribution. This article aims to address some critical reflections about which policy-makers should ask themselves before joining the implementation of a RIA system in the Brazilian context. Through a long-term perspective, the implementation of RIA must be seen as part of a permanent change in the administrative culture, understanding that RIA should be used as a further resource in the decision-making process, rather than a final solution.

Ecological aspects of American cutaneous leishmaniasis: 4. Observations on the endophilic behavior of the sandfly and the vectorial role of Psychodopygus intermedius in the Ribeira Valley region of the S.Paulo State, Brazil

The invasive tendency of Psychodopygus intermedius in the home environment, observed initially by Forattini et al. (1976), has now been confirmed by the demonstration of its high endophilic ability and by the use of human residences for shelter. Populations such as Lutzomyia migonei and Pintomyia fischeri were also present in that environment, though their low densities registered during this investigation could be an indication of their poor ability to overcome the barriers raised by the artificial environment. An objective epidemiological analysis based on the variables here given showed that human infection takes place in the extraforest environment, and the principal vectorial function falls, without doubt, on P. intermedius.

Epidemiological aspects of centipede (Scolopendromorphae: Chilopoda) bites registered in Greater S. Paulo, SP, Brazil

INTRODUCTION: The lack of basic knowledge on venomous arthropods and the benignity of the clinical manifestations contribute to the centipede bite victims' not being taken to a treatment reference center, leading to underestimation of the number of cases and minimizing the possibility of a broader epidemiological view. An inventory of the centipede bite occurrences in Greater S. Paulo, Brazil, and the therapeutic methods employed, by the main Brazilian medical center for the notification of poisoning by venomous animals, is presented. METHOD: All patient cards of the period 1980-1989 have been checked as to place, month and time of occurrence; sex, age, affected part of the body, signs and symptoms have been observed, as well as the therapeutic methods employed. The centipedes that caused the accidents were identified at the Arthropods Laboratory. RESULTS: It was registered 216 accidents, with a 69% predominance of the Greater S. Paulo and in only 63% of the cases (136) was the agent brought in by the victim for identification. The genera most frequently represented were Cryptops (58%), Otostigmus (33%) and Scolopendra (4%). Of the 136 cases, 87% showed erythema, edema, hemorrhage, burns, cephalalgia, and intense pain. There was a predominance of accidents in the warm rainy season, in the morning and for females between 21 and 60 years of age. Hands and feet were the parts of the body most affected. The benign evolution of the clinical picture (54%) made therapeutical treatment unnecessary. Only the victims of Scolopendra and Otostigmus (46%) were medicated with anesthetics (51%), analgesics (25%), antihistamines and cortisone (24%). CONCLUSION: The reproductive period of the centipedes, associated with their sinanthropic habits, contributes to the greater incidence of accidents in urban areas in the warm rainy season. Only patients bitten by Scolopendra and Otostigmus require therapeutical treatment.

Entomological aspects of Chagas' disease transmission in the domestic habitat, Argentina

OBJECTIVE: To study the risk of Trypanosoma cruzi domestic transmission using an entomological index and to explore its relationship with household's characteristics and cultural aspects. METHODS: There were studied 158 households in an endemic area in Argentina. Each household was classified according to an entomological risk indicator (number of risky bites/human). A questionnaire was administered to evaluate risk factors among householders. RESULTS: Infested households showed a wide range of risk values (0 to 5 risky bites/human) with skewed distribution, a high frequency of lower values and few very high risk households. Of all collected Triatoma infestans, 44% had had human blood meals whereas 27% had had dogs or chickens blood meals. Having dogs and birds sharing room with humans increased the risk values. Tidy clean households had contributed significantly to lower risk values as a result of low vector density. The infested households showed a 24.3% correlation between time after insecticide application and the number of vectors. But there was no correlation between the time after insecticide application and T. infestans' infectivity. The statistical analysis showed a high correlation between current values of the entomological risk indicator and Trypanosoma cruzi seroprevalence in children. CONCLUSIONS: The risk of T. cruzi domestic transmission assessed using an entomological index show a correlation with children seroprevalence for Chagas' disease and householders' habits.

Multidimensional aspects related to shiftworkers' health and well-being

The impact of shift and night work on health shows a high inter- and intra-individual variability, both in terms of kind of troubles and temporal occurrence, related to various intervening factors dealing with individual characteristics, lifestyles, work demands, company organisation, family relations and social conditions. The way we define "health" and "well-being" can significantly influence appraisals, outcomes and interventions. As the goal is the optimisation of shiftworkers' health, it is necessary to go beyond the health protection and to act for health promotion. In this perspective, not only people related to medical sciences, but many other actors (ergonomists, psychologists, sociologists, educators, legislators), as well as shiftworkers themselves. Many models have been proposed aimed at describing the intervening variables mediating and/or moderating the effects; they try to define the interactions and the pathways connecting risk factors and outcomes through several human dimensions, which refer to physiology, psychology, pathology, sociology, ergonomics, economics, politics, and ethics. So, different criteria can be used to evaluate shiftworkers' health and well-being, starting from biological rhythms and ending in severe health disorders, passing through psychological strain, job dissatisfaction, family perturbation and social dis-adaptation, both in the short- and long-term. Consequently, it appears rather arbitrary to focus the problem of shiftworkers' health and tolerance only on specific aspects (e.g. individual characteristics), but a systemic approach appears more appropriate, able to match as many variables as possible, and aimed at defining which factors are the most relevant for those specific work and social conditions. This can support a more effective and profitable (for individuals, companies, and society) adoption of preventive and compensative measures, that must refer more to "countervalues" rather than to "counterweights".

Methodological aspects of the 1993 Pelotas (Brazil) birth cohort study

This paper describes the main methodological aspects of a cohort study, with emphasis on its recent phases, which may be relevant to investigators planning to carry out similar studies. In 1993, a population based study was launched in Pelotas, Southern Brazil. All 5,249 newborns delivered in the city's hospitals were enrolled, and sub-samples were visited at the ages of one, three and six months and of one and four years. In 2004-5 it was possible to trace 87.5% of the cohort at the age of 10-12 years. Sub-studies are addressing issues related to oral health, psychological development and mental health, body composition, and ethnography. Birth cohort studies are essential for investigating the early determinants of adult disease and nutritional status, yet few such studies are available from low and middle-income countries where these determinants may differ from those documented in more developed settings.

Clinical and functional aspects of work-related musculoskeletal disorders among active workers

OBJECTIVE: To evaluate musculoskeletal disorders among active industrial workers. METHODS: The study was carried out in São Carlos, Southeastern Brazil, in 2005. One hundred and thirty-four female workers were physically evaluated and answered questions about their physical symptoms, filled out a pain scale and gave responses in the Oswestry Disability Questionnaire, and the Work Ability Index questionnaire. The data were analyzed descriptively, and in correlation tests and through applying logistic regression. The outcome was evaluated in relation to the perceptions of pain, symptoms, physical assessment, ability to work and disability. RESULTS: Clinical evaluations and sick leave presented positive correlations with the subjective variables. The Work Ability Index presented a negative correlation with the physical disability index (r=-0.69). Symptoms reported at the time of the assessment presented a good correlation with the results from the pain scale and the clinical findings. Previous sick leave showed an association with disability (OR=1.13; 95% CI:1.08;1.18). CONCLUSION: Symptom reports and pain scales may be useful for assessing current conditions at the time of evaluating individuals with work-related musculoskeletal disorders, as they are easier to apply. In more severe cases of such injuries, clinical and functional evaluations and questionnaires such as those relating to ability to work and disability are preferable. Precise and specific evaluations of these disorders may contribute towards fairer legal and administrative decisions.

Epidemiological aspects of acute viral hepatitis in São Paulo, Brazil

As few reports on the prevalence of each type of viral hepatitis have been published in our country, we studied 154 patients with acute viral hepatitis consecutively seen at the Liver Unit from November 1980 to November 1984. The frequency of hepatitis A, B and non-A, non-B was 52.6%, 27.3% and 20.1% respectively. Greater frequency in young people, previous contact with infected patients and ingestion of suspected foods were the predominant epidemiological features in the hepatitis A group. Hepatitis B was characterized by the parenteral, non-transfusional exposure, previous contact and a high occurence in health-care workers. A history of blood transfusion was a significant finding in the hepatitis non-A, non-B group. Finally, the routes of transmission were unknown in 30-40% of the three groups of patients.

Histological and immunohistochemical aspects of cutaneous leishmaniasis in nicaragua

Sixty skin biopsies of fifty-eight non-treated patients with cutaneous leishmaniasis from Nicaragua were studied. Biopsies were classified according to Ridley's histopathologic groups: 36 (60%) were included in group B (diffuse necrosis), 14 in group C (focal necrosis), 7 (11.6%) in group D (reactive tuberculoid). Only three biopsies remained unclassified. None of our cases could be included in groups A and E. Immunohistochemistry disclosed in 17 cases Russel's bodies secreting IgM and only one IgG positive. There was no correlation between the histopathologic groups and the presence of Russel's bodies. However, we believe the presence of Russel's bodies help the diagnosis of leishmaniasis. Correlation between morphological patterns and the different leishmania species was also considered.