Spectral Density Regression for Bivariate Extremes

We introduce a density regression model for the spectral density of a bivariate extreme value distribution, that allows us to assess how extremal dependence can change over a covariate. Inference is performed through a double kernel estimator, which can be seen as an extension of the Nadaraya–Watson estimator where the usual scalar responses are replaced by mean constrained densities on the unit interval. Numerical experiments with the methods illustrate their resilience in a variety of contexts of practical interest. An extreme temperature dataset is used to illustrate our methods

Shadows of the colonial past – diverging plant use in Northern Peru and Southern Ecuador

This paper examines the traditional use of medicinal plants in Northern Peru and Southern Ecuador, with special focus on the Departments of Piura, Lambayeque, La Libertad, Cajamarca, and San Martin, and in Loja province, with special focus on the development since the early colonial period. Northern Peru represents the locus of the old Central Andean "Health Axis." The roots of traditional healing practices in this region go as far back as the Cupisnique culture early in the first millennium BC

High malnutrition rate in Venezuelan Yanomami compared to Warao Amerindians and Creoles: significant associations with intestinal parasites and anemia

Contains fulltext : 125614.pdf (publisher's version ) (Open Access)BACKGROUND: Children in rural areas experience the interrelated problems of poor growth, anemia and parasitic infections. We investigated the prevalence of and associations between intestinal helminth and protozoan infections, malnutrition and anemia in school-age Venezuelan children. METHODS: This cross-sectional study was conducted in 390 children aged 4-16 years from three rural areas of Venezuela: the Amazon Region, Orinoco Delta and Carabobo State. Stool samples were collected for direct parasitic examinations. Anthropometric indicators of chronic (height-for-age Z score) and acute (weight-for-height and Body Mass Index (BMI)-for-age Z score in respectively children under 5 years of age and children aged 5 years and above) malnutrition were calculated. Multivariate linear and logistic regression models were built to determine factors associated with nutritional status and polyparasitism. RESULTS: Hookworm and Strongyloides stercoralis prevalences were highest in children from the Amazon rainforest (respectively 72% and 18%) while children from the Orinoco Delta and Carabobo State showed higher rates of Ascaris lumbricoides (respectively 28% and 37%) and Trichuris trichiura (40% in both regions). The prevalence of Giardia lamblia infection was not significantly different between regions (average: 18%). Anemia prevalence was highest in the Amazon Region (24%). Hemoglobin levels were significantly decreased in children with a hookworm infection. Malnutrition was present in respectively 84%, 30% and 13% of children from the Amazon Region, Orinoco Delta and Carabobo State. In multivariate analysis including all regions, G. lamblia and helminth infections were significantly and negatively associated with respectively height-for-age and weight-for-height/BMI-for-age Z scores. Furthermore, hemoglobin levels were positively associated with the height-for-age Z score (0.11, 95% CI 0.02 - 0.20). CONCLUSIONS: In rural populations in Venezuela helminthiasis and giardiasis were associated with acute and chronic nutritional status respectively. These data highlight the need for an integrated approach to control transmission of parasites and improve the health status of rural Venezuelan children

'Suerte' (Luck): spirituality and well-being in El Alto, Bolivia.

This paper addresses the importance of faith and the consequent resort to supernatural forces to acquire a sense of well-being in a poor neighbourhood in the city of El Alto, Bolivia. Religious beliefs and practices have provided an important idiom for the expression of aspirations and the pursuit of ideals. The social role of emotions and its effect on well-being have been widely investigated in anthropology, especially in relation to issues of solidarity, feelings of confidence, and a sense of full personhood and empowerment (Barbalet 2001; Turner 2002; Bendelow and Williams 1997). The importance of faith is emphasised in my ethnography, showing how people’s loyalty to their notions of self-worth and the cosmological order is essential for their sense of fulfilment and empowerment. Thus, faith principles are fundamental to shed light on ideas of what people identify as well-being and fulfilment. My informants believe that luck can be controlled and changed by treating the spirits better. It can be bought and acquired by asking for protection from the spiritual forces living in the Bolivian plateau. Luck is inextricably connected with ideas of protection, destiny control and future aspirations. Bad luck is a moment of passage that leads to good luck. However, this is not a simple process. It requires a complex involvement of people, who carefully have to invest their time and money in changing their situation through various cultural practices of divination and control of destiny. Unless you are a breech baby, you are not born lucky, but you become so if you invest your resources in nourishing the forces that support the world. In exchange, these forces will assure and control an individual’s luck, freeing him/her from evil eye and envy-major sources of ill-being. This can be achieved through a ritual performed by a yatiri—local shaman, or other means, such as participating and dancing in a religious celebration in honour of a patron saint or engaging in regular acts of faith. The paper is based on ethnographic research carried out in Senkata, a poor neighbourhood in the city of El Alto, between November 2003 and November 2004. I spent 12 months in Bolivia in order to collect data for my Phd thesis. My methodology was mainly based on participant observation, informal conversations and a few formal interviews

Co-option of neutrophil fates by tissue environments

Classically considered short-lived and purely defensive leukocytes, neutrophils are unique in their fast and moldable response to stimulation. This plastic behavior may underlie variable and even antagonistic functions during inflammation or cancer, yet the full spectrum of neutrophil properties as they enter healthy tissues remains unexplored. Using a new model to track neutrophil fates, we found short but variable lifetimes across multiple tissues. Through analysis of the receptor, transcriptional, and chromatin accessibility landscapes, we identify varying neutrophil states and assign non-canonical functions, including vascular repair and hematopoietic homeostasis. Accordingly, depletion of neutrophils compromised angiogenesis during early age, genotoxic injury, and viral infection, and impaired hematopoietic recovery after irradiation. Neutrophils acquired these properties in target tissues, a process that, in the lungs, occurred in CXCL12-rich areas and relied on CXCR4. Our results reveal that tissues co-opt neutrophils en route for elimination to induce programs that support their physiological demands