Sperm death and dumping in Drosophila

Mating with more than one male is the norm for females of many species. In addition to generating competition between the ejaculates of different males, multiple mating may allow females to bias sperm use. In Drosophila melanogaster, the last male to inseminate a female sires approximately 80% of subsequent progeny. Both sperm displacement, where resident sperm are removed from storage by the incoming ejaculate of the copulating male, and sperm incapacitation, where incoming seminal fluids supposedly interfere with resident sperm, have been implicated in this pattern of sperm use. But the idea of incapacitation is problematic because there are no known mechanisms by which an individual could damage rival sperm and not their own. Females also influence the process of sperm use, but exactly how is unclear. Here we show that seminal fluids do not kill rival sperm and that any 'incapacitation' is probably due to sperm ageing during sperm storage. We also show that females release stored sperm from the reproductive tract (sperm dumping) after copulation with a second male and that this requires neither incoming sperm nor seminal fluids. Instead, males may cause stored sperm to be dumped or females may differentially eject sperm from the previous mating

Paving (through) Amazonia: Neoliberal Urbanism and the Reperipheralization of Roraima

This paper examines the neoliberal reshaping of infrastructure provision in Brazil's extreme north since the mid-1990s, when roadway investments resulted in unprecedented regional connectivity. The BR-174 upgrade, the era's most important project, marked a transition from resource-based developmentalism to free-market transnationalism. Primarily concerned with urban competitiveness, the federal government funded the trunk roadway's paving to facilitate manufacturing exports from Manaus. While an effort was made to minimize deforestation, planners sidelined development implications in adjacent Roraima. The state's urban system has thus experienced reperipheralization and intensified primacy. Market-led growth now compounds the inheritance of hierarchical centralism and ongoing governmental neglect. Our study shows a vast territory dependent on primate cities for basic goods and services. Travelling with Roraimans from bypassed towns, we detected long-distance passenger transportation and surface logistics with selective routes. Heterogeneous Roraiman (im)mobilities comprise middle-class tourism and heightened consumerism as well as informal mobility tactics and transnational circulations of precarious labor. The paper exhorts neoliberal urbanism research to look beyond both Euro America's metropoles and their Global South counterparts. Urbanization dynamics in Brazil's extreme north demonstrate that market-disciplined investments to globalize cities produce far-reaching spatial effects. These are felt even by functionally-articulated-yet-marginalized peripheries in ostensibly remote locations

A novel case of human visceral leishmaniasis from the urban area of the city of Rio de Janeiro: autochthonous or imported from Spain ?

Universidade Federal do Estado do Rio de Janeiro. Centro de Ciências Biológicas e da Saúde. Hospital Universitário Gaffrée e Guinle, 10ª Enfermaria. Rio de Janeiro, RJ, Brasil.Universidade Federal do Estado do Rio de Janeiro. Centro de Ciências Biológicas e da Saúde. Hospital Universitário Gaffrée e Guinle, 10ª Enfermaria. Rio de Janeiro, RJ, Brasil.Universidade Federal do Estado do Rio de Janeiro. Centro de Ciências Biológicas e da Saúde. Hospital Universitário Gaffrée e Guinle, 10ª Enfermaria. Rio de Janeiro, RJ, Brasil.Universidade Federal do Estado do Rio de Janeiro. Centro de Ciências Biológicas e da Saúde. Hospital Universitário Gaffrée e Guinle, 10ª Enfermaria. Rio de Janeiro, RJ, Brasil.Universidade Federal do Estado do Rio de Janeiro. Centro de Ciências Biológicas e da Saúde. Hospital Universitário Gaffrée e Guinle, 10ª Enfermaria. Rio de Janeiro, RJ, Brasil.Universidade Federal do Estado do Rio de Janeiro. Centro de Ciências Biológicas e da Saúde. Hospital Universitário Gaffrée e Guinle, 10ª Enfermaria. Rio de Janeiro, RJ, Brasil.Universidade Federal do Estado do Rio de Janeiro. Centro de Ciências Biológicas e da Saúde. Hospital Universitário Gaffrée e Guinle, 10ª Enfermaria. Rio de Janeiro, RJ, Brasil.Universidade Federal do Estado do Rio de Janeiro. Centro de Ciências Biológicas e da Saúde. Hospital Universitário Gaffrée e Guinle, 10ª Enfermaria. Rio de Janeiro, RJ, Brasil.Universidade Federal do Estado do Rio de Janeiro. Centro de Ciências Biológicas e da Saúde. Hospital Universitário Gaffrée e Guinle, 10ª Enfermaria. Rio de Janeiro, RJ, Brasil.Universidade Federal do Estado do Rio de Janeiro. Centro de Ciências Biológicas e da Saúde. Hospital Universitário Gaffrée e Guinle. Serviço de Anatomia Patológica. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Nacional de Infectologia Evandro Chagas. Laboratório de Pesquisa Clínica e Vigilância em Leishmanioses. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Nacional de Infectologia Evandro Chagas. Laboratório de Pesquisa Clínica e Vigilância em Leishmanioses. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Nacional de Infectologia Evandro Chagas. Laboratório de Pesquisa Clínica e Vigilância em Leishmanioses. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Nacional de Infectologia Evandro Chagas. Laboratório de Pesquisa Clínica e Vigilância em Leishmanioses. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Nacional de Infectologia Evandro Chagas. Laboratório de Pesquisa Clínica e Vigilância em Leishmanioses. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Nacional de Infectologia Evandro Chagas. Laboratório de Pesquisa Clínica e Vigilância em Leishmanioses. Rio de Janeiro, RJ, Brasil

Molecular Characterization of a Strawberry FaASR Gene in Relation to Fruit Ripening

BACKGROUND: ABA-, stress- and ripening-induced (ASR) proteins have been reported to act as a downstream component involved in ABA signal transduction. Although much attention has been paid to the roles of ASR in plant development and stress responses, the mechanisms by which ABA regulate fruit ripening at the molecular level are not fully understood. In the present work, a strawberry ASR gene was isolated and characterized (FaASR), and a polyclonal antibody against FaASR protein was prepared. Furthermore, the effects of ABA, applied to two different developmental stages of strawberry, on fruit ripening and the expression of FaASR at transcriptional and translational levels were investigated. METHODOLOGY/PRINCIPAL FINDINGS: FaASR, localized in the cytoplasm and nucleus, contained 193 amino acids and shared common features with other plant ASRs. It also functioned as a transcriptional activator in yeast with trans-activation activity in the N-terminus. During strawberry fruit development, endogenous ABA content, levels of FaASR mRNA and protein increased significantly at the initiation of ripening at a white (W) fruit developmental stage. More importantly, application of exogenous ABA to large green (LG) fruit and W fruit markedly increased endogenous ABA content, accelerated fruit ripening, and greatly enhanced the expression of FaASR transcripts and the accumulation of FaASR protein simultaneously. CONCLUSIONS: These results indicate that FaASR may be involved in strawberry fruit ripening. The observed increase in endogenous ABA content, and enhanced FaASR expression at transcriptional and translational levels in response to ABA treatment might partially contribute to the acceleration of strawberry fruit ripening

Role of Human-Mediated Dispersal in the Spread of the Pinewood Nematode in China

Background: Intensification of world trade is responsible for an increase in the number of alien species introductions. Human-mediated dispersal promotes not only introductions but also expansion of the species distribution via long-distance dispersal. Thus, understanding the role of anthropogenic pathways in the spread of invading species has become one of the most important challenges nowadays. Methodology/Principal Findings: We analysed the invasion pattern of the pinewood nematode in China based on invasion data from 1982 to 2005 and monitoring data on 7 locations over 15 years. Short distance spread mediated by long-horned beetles was estimated at 7.5 km per year. Infested sites located further away represented more than 90% of observations and the mean long distance spread was estimated at 111–339 km. Railways, river ports, and lakes had significant effects on the spread pattern. Human population density levels explained 87% of the variation in the invasion probability (P,0.05).Since 2001, the number of new records of the nematode was multiplied by a factor of 5 and the spread distance by a factor of 2. We combined a diffusion model to describe the short distance spread with a stochastic,individual based model to describe the long distance jumps. This combined model generated an error of only 13% when used to predict the presence of the nematode. Under two climate scenarios (stable climate or moderate warming), projections of the invasion probability suggest that this pest could expand its distribution 40–55% by 2025. Conclusions/Significance: This study provides evidence that human-induced dispersal plays a fundamental role in the spread of the pinewood nematode, and appropriate control measures should be taken to stop or slow its expansion. This model can be applied to Europe, where the nematode had been introduced later, and is currently expanding its distribution. Similar models could also be derived for other species that could be accidentally transported by humans

Who Eats Whom in a Pool? A Comparative Study of Prey Selectivity by Predatory Aquatic Insects

Predatory aquatic insects are a diverse group comprising top predators in small fishless water bodies. Knowledge of their diet composition is fragmentary, which hinders the understanding of mechanisms maintaining their high local diversity and of their impacts on local food web structure and dynamics. We conducted multiple-choice predation experiments using nine common species of predatory aquatic insects, including adult and larval Coleoptera, adult Heteroptera and larval Odonata, and complemented them with literature survey of similar experiments. All predators in our experiments fed selectively on the seven prey species offered, and vulnerability to predation varied strongly between the prey. The predators most often preferred dipteran larvae; previous studies further reported preferences for cladocerans. Diet overlaps between all predator pairs and predator overlaps between all prey pairs were non-zero. Modularity analysis separated all primarily nectonic predator and prey species from two groups of large and small benthic predators and their prey. These results, together with limited evidence from the literature, suggest a highly interconnected food web with several modules, in which similarly sized predators from the same microhabitat are likely to compete strongly for resources in the field (observed Pianka’s diet overlap indices >0.85). Our experiments further imply that ontogenetic diet shifts are common in predatory aquatic insects, although we observed higher diet overlaps than previously reported. Hence, individuals may or may not shift between food web modules during ontogeny

Remote detection of invasive alien species

The spread of invasive alien species (IAS) is recognized as the most severe threat to biodiversity outside of climate change and anthropogenic habitat destruction. IAS negatively impact ecosystems, local economies, and residents. They are especially problematic because once established, they give rise to positive feedbacks, increasing the likelihood of further invasions and spread. The integration of remote sensing (RS) to the study of invasion, in addition to contributing to our understanding of invasion processes and impacts to biodiversity, has enabled managers to monitor invasions and predict the spread of IAS, thus supporting biodiversity conservation and management action. This chapter focuses on RS capabilities to detect and monitor invasive plant species across terrestrial, riparian, aquatic, and human-modified ecosystems. All of these environments have unique species assemblages and their own optimal methodology for effective detection and mapping, which we discuss in detail