A new species of Calloconophora Dietrich (Hemiptera, Membracidae) from the semi-arid region of northeastern Brazil

A new species of treehopper, Calloconophora gaudencia sp. nov., from Araruna, Paraíba State, is described and illustrated.

Duas novas espécies de Enchenopa Amyot & Serville (Hemiptera, Membracidae) do semi-árido do Estado da Paraíba, Brasil

Enchenopa eunicea sp. nov. e Enchenopa minuta sp. nov. (ambas de São José dos Cordeiros, Paraíba, Brasil ) são descritas e ilustradas.

Cannabis use as a means of socialization?: new consumption patterns among heavy users

Purpose: After tobacco and alcohol, cannabis is the most used substance among adolescents in Switzerland. Our aim is to assess whether cannabis use has become an ordinary means of socialization. We hypothesize that cannabis consumption has become a normative, although still illegal, behavior. Methods: As part of a larger qualitative study aimed at assessing new ways [patterns] of cannabis consumption, 16 daily cannabis consumers (11 males) and 2 former heavy consumers (both females), aged 15 to 20 years, participated in interviews and focus groups. Data were transcribed verbatim and analyzed using Atlas.ti qualitative analysis software. Results: Most consumers define the beginning of their consumption as a moment when they made new friends. They commonly use cannabis in group settings, which encourages the belief that all adolescents use cannabis. Thus, cannabis is mainly identified as an everyday social act. Joints are smoked like cigarettes: at all times of the day, during or after school or work with peers, often starting at lunch break, and mostly in public places. Friends offer a joint in a group setting, much like beer in a bar, as a means of making contact. Consumption invariably increases while socializing on vacation: "During vacation, we smoke up to 10-15 joints a day; at the end we're just dead." Additionally, in order to obtain cannabis, consumers have to be part of the right networks; they generally have several dealers to assure their supply, buy and sell themselves, or practice group-buying. As a result, all friends or acquaintances of consumers are themselves cannabis users. For instance, 4 boys, who say they are best friends, always smoke together and that, in order to quit, "All four of us should say to ourselves, 'Okay, now, let's all stop smoking'. That would be the only solution. . .but it would be impossible!" The 2 former consumers state that when they started using cannabis, "I found myself little by little in a vicious circle where I saw only people who also smoked". When they quit, they separated from their group of friends: "Either you make new friends who don't smoke or you smoke." Conclusions: Discussions with consumers demonstrate a normative facet of cannabis consumption as part of teenage socialization. Consequently, cannabis consumers develop a significant dependency since a majority of their friends use cannabis and their consumption involves most of their daily social life. Our study highlights the need for clear messages about the harmful aspects of using this substance while also suggesting that cessation efforts should include helping users separate from their consumption milieu. Sources of Support: Dept. of Public Health of the canton of Vaud.

Breeding system and genetic variance in the monogamous, semi-social shrew, Crocidura russula

The population-genetic consequences of monogamy and male philopatry (a rare breeding system in mammals) were investigated using microsatellite markers in the semisocial and anthropophilic shrew Crocidura russula. A hierarchical sampling design over a 16-km geographical transect revealed a large genetic diversity (h = 0.813) with significant differentiation among subpopulations (F-ST = 5-6%), which suggests an exchange of 4.4 migrants per generation. Demic effective-size estimates were very high, due both to this limited gene inflow and to the inner structure of subpopulations. These were made of 13-20 smaller units (breeding groups), comprising an estimate of four breeding pairs each. Members of the same breeding groups displayed significant coancestries (F-LS = 9-10%), which was essentially due to strong male kinship: syntopic males were on average related at the half-sib level. Female dispersal among breeding groups was not complete (similar to 39%), and insufficient to prevent inbreeding. From our results, the breeding strategy of C. russula seems less efficient than classical mammalian systems (polygyny and male dispersal) in disentangling coancestry from inbreeding, but more so in retaining genetic variance.

III Simpósio Brasileiro de Captação de Água de Chuva no Semi-Árido - os Sistemas de Water Harvesting e sua Aplicação em Cabo Verde

A localização geográfica do arquipélago de Cabo Verde na zona saheliana entre as isoietas de 250 mm e 500 mm aproximadamente, aliada aos condicionalismos físicos, climáticos e económicos explicam em grande parte, os escassos recursos hídricos disponíveis. Devido ao caracter torrencial das chuvas, os resultados de aplicação das diferentes técnicas e sistemas de “water harvesting”, provaram no passado de que se tratam de tecnologias que podem contribuir para uma melhor gestão dos recursos hídricos. Por esta razão, deverão continuar a fazer parte dos programas de investigação aplicada, aperfeiçoadas e divulgadas no seio das comunidades rurais e nas áreas urbanas devido ao baixo custo do preço da água captada e as vantagens de caracter ambiental. Este trabalho faz uma abordagem sobre as tecnologias de aproveitamento de águas superficiais, com destaque para os sistemas de “water harvesting”, e discute as potencialidades do seu desenvolvimento em Cabo Verde.

Seasonality of insects in the semi-arid Caatinga of northeastern Brazil

Insects are essential to tropical ecosystems functioning. In semi-arid regions, the increase in abundance and/or activity (e.g. reproduction and foraging behavior) of insects is usually associated with climatic variables. The present study investigates which climatic variables are best predictors of insect abundance in an area of Caatinga in northeastern Brazil. Individuals were sampled for 24 months using Malaise and pitfall traps, and beating trays. A total of 58925 individuals belonging to 20 insect orders were collected. The most abundant orders were Hymenoptera, Diptera, Collembola and Coleoptera. Most orders studied showed a clear maximum abundance in the rainy season. Rainfall and humidity were the best predictors of insect abundance in the Caatinga. However, no climatic variable could explain Psocoptera and Blattodea variance in abundance/activity. Our results suggest that climatic changes associated with rainfall patterns in the Caatinga may affect ecosystem processes and services that depend direct or indirectly on insect abundance/activity.

Fick's law adapted to cationic diffusion in a semi-infinite solid: application to spinel megacrystals

In alkaline lavas, the chemical zoning of megacrystals of spinel is due to the cationic exchange between the latter and the host lava. The application of Fick's law to cationic diffusion profiles allows to calculate the time these crystals have stayed in the lava. Those which are in a chemical equilibrium were in contact with the lava during 20 to 30 days, whereas megacrystals lacking this equilibrium were in contact only for 3 or 4 days. The duration of the rise of an ultrabasic nodule in the volcanic chimney was calculated by applying Stokes' law.

Seasonal activity of Dinoponera quadriceps Santschi (Formicidae, Ponerinae) in the semi-arid Caatinga of northeastern Brazil

Seasonal activity of Dinoponera quadriceps Santschi (Formicidae, Ponerinae) in the semi-arid Caatinga of northeastern Brazil. We studied seasonal foraging patterns of the queenless ant D. quadriceps (Formicidae, Ponerinae) for 24 months in a Caatinga area of northeastern Brazil, an ecosystem characterized by strong climatic changes throughout the year, in order to determine if regulation of worker activity is based on environmental conditions (air temperature, relative humidity, precipitation) and/or food resources (potential prey: Coleoptera, Diptera, Hemiptera, Hymenoptera, Lepidoptera, Orthoptera, Araneae, Chilopoda and Diplopoda). Foraging activity of D. quadriceps varied over the course of both years, with the highest frequency occurring from May to August, corresponding to the late rainy season and early dry season. This foraging activity was negatively correlated with temperature and positively correlated with the availability of potential prey, but not with total abundance of soil arthropods or with rainfall and relative humidity. Diet composition, in relation to the main taxonomic prey groups, seems to be common to the species, regardless of habitat. Our results suggest that D. quadriceps workers adjust foraging activity to the most suitable period of the year, to avoid thermal stress and increase efficiency. Thus, they present an appropriate behavioral response to seasonal fluctuations in the Caatinga.

Effects of prior repeated-sprints with different recovery duration on oxygen uptake kinetics during subsequent heavy-exercise

Introduction: Prior repeated-sprints (6) has become an interesting method to resolve the debate surrounding the principal factors that limits the oxygen uptake (V'O2) kinetics at the onset of exercise [i.e., muscle O2 delivery (5) or metabolic inertia (3)]. The aim of this study was to compare the effects of two repeated-sprints sets of 6x6s separated by different recovery duration between the sprints on V'O2 and muscular de-oxygenation [HHb] kinetics during a subsequent heavy-intensity exercise. Methods: 10 male subjects performed a 6-min constant-load cycling test (T50) at intensity corresponding to half of the difference between V'O2max and the ventilatory threshold. Then, they performed two repeated-sprints sets of 6x6s all-out separated by different recovery duration between the sprints (S1:30s and S2:3min) followed, after 7-min-recovery, by the T50 (S1T50 and S2T50, respectively). V'O2, [HHb] of the vastus lateralis (VL) and surface electromyography activity [i.e., root-mean-square (RMS) and the median frequency of the power density spectrum (MDF)] from VL and vastus medialis (VM) were recorded throughout T50. Models using a bi-exponential function for the overall T50 and a mono-exponential for the first 90s of T50 were used to define V'O2 and [HHb] kinetics respectively. Results: V'O2 mean value was higher in S1 (2.9±0.3l.min-1) than in S2 (1.2±0.3l.min-1); (p<0.001). The peripheral blood flow was increased after sprints as attested by a higher basal heart rate (HRbaseline) (S1T50: +22%; S2T50: +17%; p≤0.008). Time delay [HHb] was shorter for S1T50 and S2T50 than for T50 (-22% for both; p≤0.007) whereas the mean response time of V'O2 was accelerated only after S1 (S1T50: 32.3±2.5s; S2T50: 34.4±2.6s; T50: 35.7±5.4s; p=0.031). There were no significant differences in RMS between the three conditions (p>0.05). MDF of VM was higher during the first 3-min in S1T50 than in T50 (+6%; p≤0.05). Conclusion: The study show that V'O2 kinetics was speeded by prior repeated-sprints with a short (30s) but not a long (3min) inter-sprints-recovery even though the [HHb] kinetics was accelerated and the peripheral blood flow was enhanced after both sprints. S1, inducing a greater PCr depletion (1) and change in the pattern of the fibres recruitment (increase in MDF) compared with S2, may decrease metabolic inertia (2), stimulate the oxidative phosphorylation activation (4) and accelerate V'O2 kinetics at the beginning of the subsequent high-intensity exercise.

O Sistema Semi-Presidencialista Cabo-verdiano: A Relação entre os Poderes Executivo e Legislativo

O artigo procura analisar a relação que se estabelece entre o poder executivo e legislativo no sistema de governo cabo-verdiano, onde Investigadores buscam compreendê-lo, tendo em conta a sua configuração prática, teórica e constitucional. Há que realçar a proeminência do debate e dos estudos realizados no sentido de compreender como é que a academia científica procura debelar esta problemática. Duas questões são pertinentes neste debate: a primeira refere-se à configuração teórico-constitucional do sistema de governo cabo-verdiano e a outra à prática política e legislativa.

The semi-presidential system of Cape Verde: the relationship between the executive and the legislative powers = O sistema semi-presidencialista caboverdiano: a relação entre os poderes executivo e legislativo

e article analyses the relationship established between the executive and legislative powers in the Cape Verdean government system where researchers seek to understand it, taking into account their theoretical and constitutional setting practice. It should be noted the prominence of the debate and studies undertaken to understand how the scienti c academy seeks to eradicate this problem. Two issues are relevant in this debate: the rst reporting to the theoretical and constitutional con guration of Cape Verdean government system and the other to its policy and legislative practice. Keywords: Cape Verde. Semi-presidential System. Systems of Government. Legislative and Executive Powers.

Fixação do N2 em leucena (Leucaena leucocephala) em solo da região semi-árida brasileira submetido à salinização

Com a finalidade de avaliar a tolerância de rhizobium loti em Leucaena leucocephala cv K8, submetida a níveis crescentes de salinidade, realizou-se um experimento em casa de vegetação, usando-se um Podzólico Vermelho-Amarelo textura franco-arenosa, coletado em Serra Talhada (PE). O experimento obedeceu ao arranjo fatorial 5 x 4, no delineamento em blocos ao acaso, com 3 repetições. Foram usados 5 níveis de salinidade do solo (C.E. = 1,5; 6,6; 10,1; 12,8 e 14,4 dS m-1) e 2 tratamentos inoculados (NFB 494 e SEMIA 6069), fertilização nitrogenada com 200 mg kg-1 de N (NH4NO3), e o controle sem inoculação e sem adubação nitrogenada. O incremento dos níveis crescentes de salinidade reduziu a nodulação (número e massa de nódulos), o rendimento de matéria seca e a acumulação de N na parte aérea. O tratamento com fertilização nitrogenada inibiu totalmente a nodulação em leucena, em todos os níveis de salinidade; contudo, promoveu melhores rendimentos na acumulação de N e na produção de matéria seca. Observou-se resposta significativa das plantas inoculadas com a estirpe SEMIA 6069, em todas as características avaliadas, superando os resultados obtidos com o isolado NFB 494.

Study of the variability in chemical composition of bark layers of Quercus Suber L. from different production areas

Cork is the bark of the cork oak tree (Quercus suber L), a renewable and biodegradable raw bioresource concentrated mainly in the Mediterranean region. Development of its potential uses as a biosorbent will require the investigation of its chemical composition; such information can be of help to understand its interactions with organic pollutants. The present study investigates the summative chemical composition of three bark layers (back, cork, and belly) of five Spanish cork samples and one cork sample from Portugal. Suberin was the main component in all the samples (21.1 to 53.1%), followed by lignin (14.8 to 31%), holocellulose (2.3 to 33.6%), extractives (7.3 to 20.4%), and ash (0.4 to 3.3%). The Kruskal-Wallis test was used to determine whether the variations in chemical composition with respect to the production area and bark layers were significant. The results indicate that, with respect to the bark layer, significant differences were found only for suberin and holocellulose contents: they were higher in the belly and cork than in the back. Based on the results presented, cork is a material with a lot of potential because of its heterogeneity in chemical composition

Influence of tree species on the herbaceous understory and soil chemical characteristics in a silvopastoral system in semi-arid northeastern Brazil

Studies from some semi-arid regions of the world have shown the beneficial effect of trees in silvopastoral systems, by promoting the formation of resource islands and increasing the sustainability of the system. No data are available in this respect for tree species of common occurrence in semi-arid Northeastern Brazil. In the present study, conducted in the summer of 1996, three tree species (Zyziphus joazeiro, Spondias tuberosa and Prosopis juliflora: ) found within Cenchrus ciliaris pastures were selected to evaluate differences on herbaceous understory and soil chemical characteristics between samples taken under the tree canopy and in open grass areas. Transects extending from the tree trunk to open grass areas were established, and soil (0-15 cm) and herbaceous understory (standing live biomass in 1 m² plots) samples were taken at 0, 25, 50, 100, 150 and 200% of the average canopy radius (average radius was 6.6 ± 0.5, 4.5 ± 0.5, and 5.3 ± 0.8 m for Z. joazeiro, P. juliflora, and S. tuberosa , respectively). Higher levels of soil C, N, P, Ca, Mg, K, and Na were found under the canopies of Z. joazeiro and P. juliflora: trees, as compared to open grass areas. Only soil Mg organic P were higher under the canopies of S. tuberosa trees, as compared to open grass areas. Herbaceous understory biomass was significantly lower under the canopy of S. tuberosa and P. juliflora trees (107 and 96 g m-2, respectively) relatively to open grass areas (145 and 194 g m-2). No herbaceous biomass differences were found between Z. joazeiro canopies and open grass areas (107 and 87 g m-2, respectively). Among the three tree species studied, Z. joazeiro was the one that presented the greatest potential for use in a silvopastoral system at the study site, since it had a larger nutrient stock in the soil without negatively affecting herbaceous understory biomass, relatively to open grass areas.