Food resources influencing the asexual reproductive cycle of coronate Scyphozoa

The study of the strobilation process, a feature unique in the class Scyphozoa, is an issue that helps understanding the patterns of asexual reproduction in sessile invertebrates. Many inducers of asexual reproduction are known for scyphozoans. However, the influence of food resources on the strobilation of Coronate Scyphozoa has never been tested. WO observed strobilation of a large number of polyps of Nausithoe aurea, from a wide sampling area along the South Atlantic coast of Brazil, through the administration of controlled number of hatched nauplii of Artemia franciscana under a previous tested starvation and feeding protocol. The number of strobilations between and within groups varied and the fate and shape of strobilation deviated from the biology reported in the original description. Artificial seawater was used to reduce the influence of dissolved organic matter as likely important alternative nourishment.

Reproductive cycle of Ophionereis reticulata (Ophiuroidea, Echinodermata) on the southeast coast of Brazil

The reproductive cycle of Ophionereis reticulata, a common sediment-rocky shore-interface ophiuroid, was examined monthly from January 2002 to January 2003 at Praia Grande beach (Sao Sesbatiao, state of Sao Paulo, Brazil). Mature individuals were found from January 2002 to April 2002 and from November 2002 to January 2003. Spawning was regcorded from January 2002 to March 2002 and from November 2002 to January 2003. Mature sperm is still present in April which could be involved in the fertilization of the last oocytes spawned in March and April. November and December marked the final point in the maturation process, with a high concentration of yolk and lipid nutrients in the oocytes. Ophionereis reticulata showed, for the period analyzed, a single spawning period, during spring and summer.

Do individuals in better condition survive for longer? Field survival estimates according to male alternative reproductive tactics and sex

There is a gap in terms of the supposed survival differences recorded in the field according to individual condition. This is partly due to our inability to assess survival in the wild. Here we applied modern statistical techniques to field-gathered data in two damselfly species whose males practice alternative reproductive tactics (ARTs) and whose indicators of condition in both sexes are known. In Paraphlebia zoe, there are two ART: a larger black-winged (BW) male which defends mating territories and a smaller hyaline-winged (HW) male that usually acts as a satellite. In this species, condition in both morphs is correlated with body size. In Calopteryx haemorrhoidalis, males follow tactics according to their condition with males in better condition practicing a territorial ART. In addition, in this species, condition correlates positively with wing pigmentation in both sexes. Our prediction for both species was that males practicing the territorial tactic will survive less longer than males using a nonterritorial tactic, and larger or more pigmented animals will survive for longer. In P. zoe, BW males survived less than females but did not differ from HW males, and not necessarily larger individuals survived for longer. In fact, size affected survival but only when group identity was analysed, showing a positive relationship in females and a slightly negative relationship in both male morphs. For C. haemorrhoidalis, survival was larger for more pigmented males and females, but size was not a good survival predictor. Our results partially confirm assumptions based on the maintenance of ARTs. Our results also indicate that female pigmentation, correlates with a fitness component - survival - as proposed by recent sexual selection ideas applied to females.

Violence and reproductive health preceding flight from war : accounts from Somali born women in Sweden

Background: Political violence and war are push factors for migration and social determinants of health among migrants. Somali migration to Sweden has increased threefold since 2004, and now comprises refugees with more than 20 years of war experiences. Health is influenced by earlier life experiences with adverse sexual and reproductive health, violence, and mental distress being linked. Adverse pregnancy outcomes are reported among Somali born refugees in high-income countries. The aim of this study was to explore experiences and perceptions on war, violence, and reproductive health before migration among Somali born women in Sweden. Method: Qualitative semi-structured individual interviews were conducted with 17 Somali born refugee women of fertile age living in Sweden. Thematic analysis was applied. Results: Before migration, widespread war-related violence in the community had created fear, separation, and interruption in daily life in Somalia, and power based restrictions limited access to reproductive health services. The lack of justice and support for women exposed to non-partner sexual violence or intimate partner violence reinforced the risk of shame, stigmatization, and silence. Social networks, stoicism, and faith constituted survival strategies in the context of war. Conclusions: Several factors reinforced non-disclosure of violence exposure among the Somali born women before migration. Therefore, violence-related illness might be overlooked in the health care system. Survival strategies shaped by war contain resources for resilience and enhancement of well-being and sexual and reproductive health and rights in receiving countries after migration.

Knowledge and perceptions regarding sexual and reproductive health among high school students in Kathmandu, Nepal

Background: Nepal recently began teaching sexual education in the school system and has established youth friendly services in order to meet the need of increased sexual and reproductive knowledge among the youth. Objective: To examine the sexual and reproductive knowledge and perceptions among young people attending schools in Kathmandu. Method: A written questionnaire was distributed to 160 students, in a classroom environment, in four schools in Kathmandu. Results: Two thirds of the females and nearly 60% of the males knew that it was possible to get sexually transmitted infection (STI) during one sexual encounter and more than half of the students knew when in the menstrual cycle conception was more likely to occur . One third of the participants did not know that it was possible to become pregnant after having intercourse once. The males demonstrated less knowledge than the females regarding every aspect of sex and reproduction, with the exception of pregnancy prevention. Conclusion and clinical implications: For the youths in this study, it was more important to prevent unwanted pregnancies than to protect oneself from STIs. Establishment of a hotline on the internet, where personalized and confidential counselling can be offered may complement the comprehensive sexual education in schools.

Negotiating collective and individual agency : a qualitative study of young women's reproductive health in rural India

The societal changes in India and the available variety of reproductive health services call for evidence to inform health systems how to satisfy young women's reproductive health needs. Inspired by Foucault's power idiom and Bandura's agency framework, we explore young women's opportunities to practice reproductive agency in the context of collective social expectations. We carried out in-depth interviews with 19 young women in rural Rajasthan. Our findings highlight how changes in notions of agency across generations enable young women's reproductive intentions and desires, and call for effective means of reproductive control. However, the taboo around sex without the intention to reproduce made contraceptive use unfeasible. Instead, abortions were the preferred method for reproductive control. In conclusion, safe abortion is key, along with the need to address the taboo around sex to enable use of "modern" contraception. This approach could prevent unintended pregnancies and expand young women's agency.

Violence and reproductive health preceding flight from war : accounts from Somali born women in Sweden

Background: Political violence and war are push factors for migration and social determinants of health among migrants. Somali migration to Sweden has increased threefold since 2004, and now comprises refugees with more than 20 years of war experiences. Health is influenced by earlier life experiences with adverse sexual and reproductive health, violence, and mental distress being linked. Adverse pregnancy outcomes are reported among Somali born refugees in high-income countries. The aim of this study was to explore experiences and perceptions on war, violence, and reproductive health before migration among Somali born women in Sweden. Method: Qualitative semi-structured individual interviews were conducted with 17 Somali born refugee women of fertile age living in Sweden. Thematic analysis was applied. Results: Before migration, widespread war-related violence in the community had created fear, separation, and interruption in daily life in Somalia, and power based restrictions limited access to reproductive health services. The lack of justice and support for women exposed to non-partner sexual violence or intimate partner violence reinforced the risk of shame, stigmatization, and silence. Social networks, stoicism, and faith constituted survival strategies in the context of war. Conclusions: Several factors reinforced non-disclosure of violence exposure among the Somali born women before migration. Therefore, violence-related illness might be overlooked in the health care system. Survival strategies shaped by war contain resources for resilience and

Entrepreneurial risk and labour's share in output

This paper presents a theoretical model which discusses the role played by the entrepreneurial risk on the distribution of the national income. In a two-period general equilibrium framework with competitive risk-averse entrepreneurs it is shown that the highest the risk borne by firms, the lower will be real wages, employment and the labour's share in output. The model helps explain the fall of the labour's share in the Brazilian output during the 1980s.

Output convergence in Mercosur: multivariate time series evidence

The aim of this paper is to provide evidence on output convergence among the Mercosur countries and associates, using multivariate time-series tests. The methodology is based on a combination of tests and estimation procedures, both univariate and multivariate, applied to the differences in per capita real income. We use the definitions of time-series convergence proposed by Bernard & Durlauf and apply unit root and tests proposed by Abuaf & Jorion and Taylor & Sarno. In this same multivariate context, the Flôres, Preumont & Szafarz and Breuer, MbNown & Wallace tests, which allow for the existence of correlations across the series without imposing a common speed of mean reversion, identify the countries that convergence. Concerning the empirical results, there is evidence of long-run convergence or, at least, catching up, for the smaller countries, Bolivia, Paraguay, Peru and Uruguay, towards Brazil and, to some extent, Argentina. In contrast, the evidence on convergence for the larger countries is weaker, as they have followed different (or rather opposing) macroeconomic policy strategies. Thus the future of the whole area will critically depend on the ability of Brazil, Argentina and Chile to find some scope for more cooperative policy actions.

Do shocks permanently change output? : Local persistency in economic time series

While it is recognized that output fuctuations are highly persistent over certain range, less persistent results are also found around very long horizons (Conchrane, 1988), indicating the existence of local or temporary persistency. In this paper, we study time series with local persistency. A test for stationarity against locally persistent alternative is proposed. Asymptotic distributions of the test statistic are provided under both the null and the alternative hypothesis of local persistency. Monte Carlo experiment is conducted to study the power and size of the test. An empirical application reveals that many US real economic variables may exhibit local persistency.

Análise de ecossistemas aquáticos através do método input-output : estudo de caso lagoa Itapeva (sistema lagunar costeiro do Rio Grande do Sul)

A enorme complexidade dos sistemas ecológicos tem sido uma grande barreira para a compreensão e o gerenciamento da problemática ambiental. Neste sentido a modelagem matemática é uma valiosa ferramenta, devido a sua capacidade de organizar as informações disponíveis sobre estes sistemas e de fazer previsões a seu respeito para diferentes condições. Desta forma a análise de sistemas naturais vem sendo abordada de diferentes maneiras, sendo que nas últimas décadas a teoria de ecossistemas expandiu-se e ramos específicos, que permitem seguir e predizer a evolução de ecossistemas, foram formulados. Um destes enfoques, conhecido como análise do fluxo de insumo-produto, pode ser utilizado para explicar o funcionamento e estrutura dos subsistemas de um ecossistema através da descrição dos fluxos de matéria ou energia. A análise do fluxo de insumo-produto pode ser representada através de dois modelos: o modelo determinístico ou o modelo estocástico, tendo sua origem em estudos de caso com o objetivo de analisar a econômica norte-americana, sendo uma extensão prática da teoria clássica de interdependência geral. Este trabalho faz uma abordagem sintética da evolução desta análise, avaliando dados teóricos e principalmente dados referentes à Lagoa Itapeva. A análise de input-output (determinística e estocástica) com o propósito de obter informações no que diz respeito aos fluxos (matéria e energia), é bastante simples; sendo que os modelos determinísticos se prestam melhor para traçar um panorama global e para obter projeções para as variáveis já os modelos estocásticos são mais complexos, mas provêem uma descrição mais acurada. Na Lagoa Itapeva os processos determinísticos demonstraram um baixo índice de ciclagem do carbono entre os três compartimentos em estudo e o fluxo preferencial na normalização corresponde ao compartimento dos produtores primários, isto decorre de não existir loop nos compartimentos em estudo e também não existir fluxos em dois sentidos. Em relação à avaliação estocástica foram observadas uma baixa relação no sentido espacial superfície-meio-fundo da lagoa, e uma boa distribuição espacial norte-centro-sul. Quanto à distribuição temporal, foi constatada uma baixa concordância entre os dados analisados e os dados reais quanto das análises realizadas em intervalos de tempo pequeno (horas) e uma boa concordância nas medidas feitas quando o intervalo foi significativo (meses). Também em relação à Lagoa Itapeva, foi verificado nas análises estocásticas, utilizando-se operadores espaciais, que como a dinâmica biológica nem sempre é linear, os organismos não podem acompanhar imediatamente e perfeitamente as mudanças do ambiente, resultando em tempos de residência de matéria significativamente baixo. Além da análise dos fluxos ligados a este ecossistema lagunar, foram desenvolvidas técnicas de correção e adaptação de dados referentes à amostragem ocorrida na Lagoa durante um ano de campanha. Assim, propõe-se uma nova perspectiva no uso desta metodologia de forma simples e de fácil manipulação matemática.

The evolution of international output differences (1960-2000): From factors to productivity

This article presents a group of exercises of level and growth decomposition of output per worker using cross-country data from 1960 to 2000. It is shown that at least until 1975 factors of production (capital and education) were the main source of output dispersion across economies and that productivity variance was considerably smaller than in late years. Only after this date the prominence of productivity started to show up in the data, as the majority of the literature has found. The growth decomposition exercises showed that the reversal of relative importance of productivity vis-a-vis factors is explained by the very good (bad) performance of productivity of fast (slow) growing economies. Although growth in the period, on average, is mostly due to factors accumulation, its variance is explained by productivity.