Bourgin-Yang version of the Borsuk-Ulam theorem for Z(pk)-equivariant maps

Let G = Z(pk) be a cyclic group of prime power order and let V and W be orthogonal representations of G with V-G = W-G = W-G = {0}. Let S(V) be the sphere of V and suppose f: S(V) -> W is a G-equivariant mapping. We give an estimate for the dimension of the set f(-1){0} in terms of V and W. This extends the Bourgin-Yang version of the Borsuk-Ulam theorem to this class of groups. Using this estimate, we also estimate the size of the G-coincidences set of a continuous map from S(V) into a real vector space W'.

What do medical students think about their quality of life? A qualitative study

Background: Medical education can affect medical students' physical and mental health as well as their quality of life. The aim of this study was to assess medical students' perceptions of their quality of life and its relationship with medical education. Methods: First-to sixth-year students from six Brazilian medical schools were interviewed using focus groups to explore what medical student's lives are like, factors related to increases and decreases of their quality of life during medical school, and how they deal with the difficulties in their training. Results: Students reported a variety of difficulties and crises during medical school. Factors that were reported to decrease their quality of life included competition, unprepared teachers, excessive activities, and medical school schedules that demanded exclusive dedication. Contact with pain, death and suffering and harsh social realities influence their quality of life, as well as frustrations with the program and insecurity regarding their professional future. The scarcity of time for studying, leisure activities, relationships, and rest was considered the main factor of influence. Among factors that increase quality of life are good teachers, classes with good didactic approaches, active learning methodologies, contact with patients, and efficient time management. Students also reported that meaningful relationships with family members, friends, or teachers increase their quality of life. Conclusion: Quality of teachers, curricula, healthy lifestyles related to eating habits, sleep, and physical activity modify medical students' quality of life. Lack of time due to medical school obligations was a major impact factor. Students affirm their quality of life is influenced by their medical school experiences, but they also reframe their difficulties, herein represented by their poor quality of life, understood as necessary and inherent to the process of becoming doctors.

NONSPECIFIC INFECTIOUS DISEASES IN PREHISTORIC SAN PEDRO DE ATACAMA, NORTHERN CHILE

The region of San Pedro de Atacama, Northern Chile, has undergone several cultural and social changes after humans settled in Atacama Desert around 500 BC. The Atacameno people experienced the highest degree of social and cultural changes between 400 and 900 AD when they were assimilated into the Tiwanaku trade and political web that influenced most of the Central-Southern Andes. Under the influence of Tiwanaku, San Pedro de Atacama experienced its greatest economic development. Prior analyses of local human skeletal remains have shown a significant increase in the stature of the local population during the same period. In this paper, we investigate the impact of the Tiwanaku influence on the local epidemiological profile using the incidence of periostitis and osteomyelitis as indicators of biological stress. Surprisingly, the best epidemiological condition occurred during the final phase of influence of Tiwanaku (910-960 AD), and not during the apex influence (480-920 AD), as expected by the archaeological context. We suggest that population growth and aggregation may have counteracted the benefits of improved nutrition during the peak Tiwanaku influence. A severe drought occurred between 1,100 and 1,400 AD in Northern Chile. This could also explain the marked increase of bone infections in the post-Tiwanaku period (920-1,240 AD).

Economia política da arte moderna II/ notas para uma sistematização provisória

Paradigma tradicional de excelência artesanal, com que meios pode a pintura responder à abstração do trabalho e à sua ordenação serial, inerentes à modernização capitalista? O texto presente busca sistematizar os momentos decisivos de um percurso que se estende de Manet (1832-1883) a Rothko (1903-1970). Constitui o capítulo conclusivo de uma investigação sobre a transformação crítica do modo de pintar em modo de fabricação, fundado na superação reflexiva da dicotomia entre trabalho intelectual e corporal, imposta historicamente à sociedade. Atualizada criticamente e assinalando um fecho possível do processo da arte moderna, a pintura de Rothko põe-se como a negação de todo aspecto individual da pintura e de unidade orgânica e monádica da obra. Alcança-se assim o último termo de um processo; termo que assinala o fim do ciclo da autonomia estética como forma ligada à liberdade do sujeito, idealizado como natureza desinteressada. Para o trabalho de resistência contra a aceleração da barbárie é fundamental doravante levar em conta os fatores de heteronomia supraindividuais que, se não logram controlar toda a produção, detêm a hegemonia na esfera da circulação.

Presença e distribuição de espécies exóticas na zona de influência de duas trilhas no Parque Nacional da Serra do Cipó - MG

The presence of visitors in national parks is desirable and agrees with their management objectives. However, areas and paths under the influence of visitors are sites with a great possibility of change in the composition of vegetation due to the effects caused by the influence of walking, bicycles and horseback riding. In this work, two trails of the Serra do Cipo National Park were evaluated with the aim of studying and knowing the distribution of native and exotic species in their areas of influence. The theme of biological invasions in protected areas has been an important focus of studies since they represent a threat to biodiversity. The results show differences in the presence of exotic plants and conservation conditions between the two tracks studied.

Regionalization and access to healthcare in Brazilian states: historical and political-institutional conditioning factors

This article examines the healthcare regionalization process in the Brazilian states in the period from 2007 to 2010, seeking to identify the conditions that favor or impede this process. Referential analysis of public policies and especially of historical institutionalism was used. Three dimensions sum up the conditioning factors of regionalization: context (historical-structural, political-institutional and conjunctural), directionality (ideology, object, actors, strategies and instruments) and regionalization features (institutionality and governance). The empirical research relied mainly on the analysis of official documents and interviews with key actors in 24 states. Distinct patterns of influence in the states were observed, with regionalization being marked by important gains in institutionality and governance in the period. Nevertheless, inherent difficulties of the contexts prejudice greater advances. There is a pressing need to broaden the territorial focus in government planning and to integrate sectorial policies for medium and long-term regional development in order to empower regionalization and to overcome obstacles to the access to healthcare services in Brazil.

Hydrochemical variability at the Upper Paraguay Basin and Pantanal wetland

Compartmentalization is a prerequisite to understand large wetlands that receive water from several sources. However, it faces the heterogeneity in space and time, resulting from physical, chemical and biological processes that are specific to wetlands. The Pantanal is a vast seasonally flooded continental wetland located in the centre of South America. The chemical composition of the waters that supply the Pantanal (70 rivers) has been studied in order to establish a compartmentalization of the wetland based on soil-water interactions. A PCA-based EMMA (End-Members Mixing Analysis) procedure shows that the chemistry of the rivers can be viewed as a mixture of 3 end-members, influenced by lithology and land use, and delimiting large regions. Although the chemical composition of the end-members changed between dry and wet seasons, their spatial distribution was maintained. The results were extended to the floodplain by simple tributary mixing calculation according to the hydrographical network and to the areas of influence for each river when in overflow conditions. The resulting map highlights areas of high geochemical contrast on either side of the river Cuiaba in the north, and of the rivers Aquidauana and Abobral in the south. The PCA-based treatment on a sampling conducted in the Nhecolandia, a large sub region of the Pantanal, allowed the identification and ordering of the processes that control the geochemical variability of the surface waters. Despite an enormous variability in electrical conductivity and pH, all data collected were in agreement with an evaporation process of the Taquari River water, which supplies the region. Evaporation and associated saline precipitations (Mg-calcite, Mg-silicates K-silicates) explained more than 77% of the total variability in the chemistry of the regional surface water sampling.

Self-potential signals from an analog biogeobattery mode

A tank experiment was conducted to check if self-potential (SP) signals can be generated when buried organic matter is wire-connected to a near-surface, oxygen-rich, sediment layer. This experiment demonstrated that once wired, there was a flux of electrons (hence an electric current) between the lower and upper layers of the sandbox with the system responding as a large-scale microbial fuel cell (a type of bioelectrochemical system). An electric current was generated by this process in the wire and the SP method was used to monitor the associated electric potential distribution at the top of the tank.. The electric field was controlled by the flux of electrons through the wire, the oxidation of the organic matter, the reduction of oxygen used as a terminal electron acceptor, and the distribution of the DC resistivity in the tank. The current density through the wire was limited by the availability of oxygen and not by the oxidation of the organic matter. This laboratory experiment incorporated key elements of the biogeobattery observed in some organic-rich contaminant plumes. This analogy includes the generation of SP signals associated with a flux of electrons, the capacity of buried organic matter in sustaining anodic reactions, network resistance connecting terminal redox reactions spatially separated in space, and the existence of anodic secondary coupled reactions. A resistivity tomogram of the tank, after almost a year in operation, suggests that oxidative processes triggered by this geobattery can be imaged with this method to determine the radius of influence of the bioelectrochemical system.

An investigation about Brazilian mango and grape exports

Purpose - The objective of this paper is to characterise the transactions between European buyers and Brazilian mango and grape producers. Design/methodology/approach - The method selected for this paper was multiple case studies. The Brazilian mango and grape supply chains' export activities to Europe were investigated. The field research was undertaken in Brazil, Germany, The Netherlands and the UK. In total, 41 face-to-face interviews were carried out. Findings - The supermarkets' literature tends to generalise the strategies of retailers focusing on differentiation and preferred suppliers. However, in empirical research conducted in the UK, Germany and The Netherlands it is possible to conclude that the procurement strategies of supermarkets can vary sharply. The results reveal the presence of different agents who demand different quality standards. The level of intensity depends on consumer behaviour, the features of product commercialised and the characteristics of the production segment in each country. Research limitations/implications - First, in relation to the empirical method there is a limitation because the case study does not allow statistical generalisation. Consequently, it will be interesting to undertake quantitative research in order to quantify the variables presented and their impact on the structure of value chains. Second, the research focuses only on two stages of the supply chain, producers and buyers. Practical implications - The differences between UK and German supermarkets challenge the supermarket literature, which tends to generalise the strategies of retailers focusing on differentiation and preferred suppliers. Originality/value - The study shows that the issue of influence and activities of retail agents along the value chain can be analysed taking several variables into consideration: the products commercialised; the distribution segment; and the consumer market. This result opens the way for analysing different structures of the value chain and the impact of these differences on the entry of producers for developing countries into the global market.