9,028 research outputs found

    Shannon entropy of brain functional complex networks under the influence of the psychedelic Ayahuasca

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    The entropic brain hypothesis holds that the key facts concerning psychedelics are partially explained in terms of increased entropy of the brain's functional connectivity. Ayahuasca is a psychedelic beverage of Amazonian indigenous origin with legal status in Brazil in religious and scientific settings. In this context, we use tools and concepts from the theory of complex networks to analyze resting state fMRI data of the brains of human subjects under two distinct conditions: (i) under ordinary waking state and (ii) in an altered state of consciousness induced by ingestion of Ayahuasca. We report an increase in the Shannon entropy of the degree distribution of the networks subsequent to Ayahuasca ingestion. We also find increased local and decreased global network integration. Our results are broadly consistent with the entropic brain hypothesis. Finally, we discuss our findings in the context of descriptions of "mind-expansion" frequently seen in self-reports of users of psychedelic drugs.Comment: 27 pages, 6 figure

    Importância das folhas do imbuzeiro (Spondias tuberosa Arruda) na alimentação de caprinos e ovinos no Nordeste semi-árido.

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    O objetivo deste trabalho foi avaliar o consumo de folhas verdes e secas do imbuzeiro pelos caprinos e ovinos em áreas de caatinga de duas comunidades da região semi-árida dos Estados da Bahia e Pernambuco

    Diversidade árborea de uma floresta sob produção sustentável de madeira no Estado do Acre.

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    O inventário é uma etapa básica do manejo florestal em que é avaliada a diversidade arbórea da floresta e a sua potencialidade para o manejo. Este trabalho apresenta resultados de inventário florestal a 100% de um projeto de manejo florestal comunitário madeireiro conduzido pela Embrapa Acre em parceria com um grupo de produtores do Projeto de Colonização Pedro Peixoto, no estado Acre. A área total inventariada foi de 206,8 ha, composta por 57 talhões de tamanho médio de 3,6 ha cada um, correspondente a 48% da área total sob manejo de 12 pequenas propriedades. Foram abordadas todas as árvores com DAP a 50,0 cm. Os resultados foram expressos, por espécie, por propriedade e para a área total em: número total de árvores (NT); abundância por hectare (AB); volume total (VT); volume por hectare (V); área basal total (ABsT); área basal por hectare (ABs); índice de importância da espécie (IND); e condição de aproveitamento da tora. [...] Foram reconhecidas em campo 204 espécies, pertencentes a 136 gêneros e a 43 famílias. Foi observado acentuada concentração dos dados dendrométricos em poucas espécies, pois somente cinco espécies respondem por um terço (33,6%) do IND total

    (In)Consistencies in responses to sodium bicarbonate supplementation: a randomised, repeated measures, counterbalanced and double-blind study

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    Objectives: Intervention studies do not account for high within-individual variation potentially compromising the magnitude of an effect. Repeat administration of a treatment allows quantification of individual responses and determination of the consistency of responses. We determined the consistency of metabolic and exercise responses following repeated administration of sodium bicarbonate (SB). Design and Methods: 15 physically active males (age 25 ± 4 y; body mass 76.0 ± 7.3 kg; height 1.77 ± 0.05 m) completed six cycling capacity tests at 110% of maximum power output (CCT 110% ) following ingestion of either 0.3 g.kg -1 BM of SB (4 trials) or placebo (PL, 2 trials). Blood pH, bicarbonate, base excess and lactate were determined at baseline, pre-exercise, post-exercise and 5-min post-exercise. Total work done (TWD) was recorded as the exercise outcome. Results: SB supplementation increased blood pH, bicarbonate and base excess prior to every trial (all p ≤0.001); absolute changes in pH, bicarbonate and base excess from baseline to pre-exercise were similar in all SB trials (all p > 0.05). Blood lactate was elevated following exercise in all trials (p ≤ 0.001), and was higher in some, but not all, SB trials compared to PL. TWD was not significantly improved with SB vs. PL in any trial (SB1: +3.6%; SB2 +0.3%; SB3: +2.1%; SB4: +6.7%; all p > 0.05), although magnitude-based inferences suggested a 93% likely improvement in SB4. Individual analysis showed ten participants improved in at least one SB trial above the normal variation of the test although five improved in none. Conclusions: The mechanism for improved exercise with SB was consistently in place prior to exercise, although this only resulted in a likely improvement in one trial. SB does not consistently improve high intensity cycling capacity, with results suggesting that caution should be taken when interpreting the results from single trials as to the efficacy of SB supplementation. Trial Registration: ClinicalTrials.gov NCT0247462

    Wasted positive intentions: the role of affection and abundance on household food waste.

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    This qualitative study, grounded theory oriented, identifies familial affection and preference for abundance as major drivers of wasted food in lower-middle income American families. These positive intentions provide an improved understanding of household food waste, a problem with high environmental impact and moral implications. Based on empirical data collected with twenty caregivers via in-depth interviews, observations, and analysis of photos, this study provides novel explanations, such as on how stockpiling comfort foods in abundance ? a form of both boosting positive self-emotions and showing affection for kids ? can promote more wasted food. Other antecedents identified include multiplicity of choices, convenience, procrastination and unplanned routines. In sum, this research identifies a negative outcome of affection and food abundance in the family context, while providing a theoretically relevant general framework to help understand the food waste phenomenon. Authors suggest increasing the awareness of nutritional gatekeepers through behavioral economics principles

    Food waste paradox: antecedents of food disposal in low income households.

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    This article aims to identify antecedents of food waste among lower-middle class families ? a paradox, given the financial constraints this population faces. The importance of this research is evident in escalating environmental pressures for better use of our planet?s scarce resources. Given that most of the world is low-income, any behavioral change in this population is likely to have a considerable impact. Empirical data were collected from 14 lower-middle income Brazilian households, based on observations, in-depth interviews, photographs and a focus group (n56). Five major categories of food waste antecedents were identified: (1) excessive purchasing, (2) overpreparation, (3) caring for a pet, (4) avoidance of leftovers and (5) inappropriate food conservation. Several subcategories were also found, including impulse buying, lack of planning and preference for large packages. Surprisingly, findings show that strategies used to save money ? such as buying groceries in bulk, monthly shopping trips, preference for supermarkets and cooking from scratch ? actually end up generating more food waste. This mitigates the savings made during the purchasing phase

    A sustainable system for animal production in the brazilian semi-arid region.

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    In the semi-arid Northeast, there are about 1.0 million of farming units. Such units operate on a region characterized by heavy constraints in tenns of soil and water resources. The production systems show a low technological pattem, in sufficient to achieve an appropriate standard of living for the farmer, and, to avoid the continuous deterioration of the natural resources, mainly of the caatinga vegetation. Some studies have shown that the subsistence type of agriculture today practiced, only is successful on three in every ten years, and that livestock production, by its lower vulnerability to drought effects, has constituted the main anti-migration factor in the semi-and region. Results of a recent study conducted by Embrapa Semi-Arid workers, including small farms of 107 counties, confrrmed that trend, showing a gross income increase as livestock participation in the farm activities becomes higher. Research on livestock Production in Nontheast has generated a vast number of technologies, which, if adequately combined and operated, can assure, with no environrnental damage, economical levels of productivity and a more equitable distribution of the benefits

    Iron Compounds in Brazilian Pre-Columbian Pigments Identified by \u3csup\u3e57\u3c/sup\u3eFe Mossbauer Spectroscopy and X-Ray Powder Diffraction

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    Mossbauer spectroscopy and X-ray powder diffraction have been used to identify iron compounds in pre-Columbian pigments, probably used for art decorating, collected from the oldest archaeological site of Early Man presently known in American at Sao Raimundo Nonato, in Northeastern Brazil. The iron compounds were identified as being alpha-Fe203 (haematite) with full Morin transition supressed and small particles of alpha-FeOOH (goethite)

    Modelagem da paisagem no Parque Estadual Carlos Botelho (SP) e entorno.

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    The aim of this study was to model landscape change in a nature conservation area located in the Atlantic Forest within São Paulo State, Brazil, called Carlos Botelho State Park ? CBSP, and also in its surroundings, both currently under anthropogenic pressure. A cellular automata stochastic simulation platform - Dinamica EGO ? was used, which embodies neighborhood-based transition algorithms and the weights of evidence method as a parameterization approach. Water bodies, forest, agriculture, and forestry (eucalyptus) were considered as land cover categories in this model. Variables like distance to roads and distance to existent types of land cover in the area were crucial to explain the observed landscape changes. The prevailing conversion of land-use/land-cover was agriculture to eucalyptus. There were no findings of significant increase of human pressure in CBSP, except in a small stretch in the northwest of the Park. There is evidence that the establishment of a nature conservation area in the eastern sector of CBSP might be feasible, since it would strengthen an ecological corridor towards the Jurupará Park. Fiscalization and routine monitoring should be strictly observed, considering that the CBSP may suffer greater pressure of the eucalyptus plantations that increasingly expand into surrounding the region analyzed. To improve this research, more variables should be investigated, for example, the role the role of distance to suppliers / markets and roads, soil categories, as well as socioeconomic factors through coupled models of dynamic systems
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