No Evolutionary Shift in the Mating System of North American Ambrosia artemisiifolia (Asteraceae) Following Its Introduction to China

The mating system plays a key role during the process of plant invasion. Contemporary evolution of uniparental reproduction (selfing or asexuality) can relieve the challenges of mate limitation in colonizing populations by providing reproductive assurance. Here we examined aspects of the genetics of colonization in Ambrosia artemisiifolia, a North American native that is invasive in China. This species has been found to possess a strong self-incompatibility system and have high outcrossing rates in North America and we examined whether there has been an evolutionary shift towards the dependence on selfing in the introduced range. Specifically, we estimated outcrossing rates in one native and five invasive populations and compared levels of genetic diversity between North America and China. Based on six microsatellite loci we found that, like the native North American population, all five Chinese populations possessed a completely outcrossing mating system. The estimates of paternity correlations were low, ranging from 0.028–0.122, which suggests that populations possessed ∼8–36 pollen donor parents contributing to each maternal plant in the invasive populations. High levels of genetic diversity for both native and invasive populations were found with the unbiased estimate of gene diversity ranging from 0.262–0.289 for both geographic ranges based on AFLP markers. Our results demonstrate that there has been no evolutionary shift from outcrossing to selfing during A. artemisiifolia's invasion of China. Furthermore, high levels of genetic variation in North America and China indicate that there has been no erosion of genetic variance due to a bottleneck during the introduction process. We suggest that the successful invasion of A. artemisiifolia into Asia was facilitated by repeated introductions from multiple source populations in the native range creating a diverse gene pool within Chinese populations

Island Invasion by a Threatened Tree Species: Evidence for Natural Enemy Release of Mahogany (Swietenia macrophylla) on Dominica, Lesser Antilles

Despite its appeal to explain plant invasions, the enemy release hypothesis (ERH) remains largely unexplored for tropical forest trees. Even scarcer are ERH studies conducted on the same host species at both the community and biogeographical scale, irrespective of the system or plant life form. In Cabrits National Park, Dominica, we observed patterns consistent with enemy release of two introduced, congeneric mahogany species, Swietenia macrophylla and S. mahagoni, planted almost 50 years ago. Swietenia populations at Cabrits have reproduced, with S. macrophylla juveniles established in and out of plantation areas at densities much higher than observed in its native range. Swietenia macrophylla juveniles also experienced significantly lower leaf-level herbivory (∼3.0%) than nine co-occurring species native to Dominica (8.4–21.8%), and far lower than conspecific herbivory observed in its native range (11%–43%, on average). These complimentary findings at multiple scales support ERH, and confirm that Swietenia has naturalized at Cabrits. However, Swietenia abundance was positively correlated with native plant diversity at the seedling stage, and only marginally negatively correlated with native plant abundance for stems ≥1-cm dbh. Taken together, these descriptive patterns point to relaxed enemy pressure from specialized enemies, specifically the defoliator Steniscadia poliophaea and the shoot-borer Hypsipyla grandella, as a leading explanation for the enhanced recruitment of Swietenia trees documented at Cabrits

Diversity, Loss, and Gain of Malaria Parasites in a Globally Invasive Bird

Invasive species can displace natives, and thus identifying the traits that make aliens successful is crucial for predicting and preventing biodiversity loss. Pathogens may play an important role in the invasive process, facilitating colonization of their hosts in new continents and islands. According to the Novel Weapon Hypothesis, colonizers may out-compete local native species by bringing with them novel pathogens to which native species are not adapted. In contrast, the Enemy Release Hypothesis suggests that flourishing colonizers are successful because they have left their pathogens behind. To assess the role of avian malaria and related haemosporidian parasites in the global spread of a common invasive bird, we examined the prevalence and genetic diversity of haemosporidian parasites (order Haemosporida, genera Plasmodium and Haemoproteus) infecting house sparrows (Passer domesticus). We sampled house sparrows (N = 1820) from 58 locations on 6 continents. All the samples were tested using PCR-based methods; blood films from the PCR-positive birds were examined microscopically to identify parasite species. The results show that haemosporidian parasites in the house sparrows' native range are replaced by species from local host-generalist parasite fauna in the alien environments of North and South America. Furthermore, sparrows in colonized regions displayed a lower diversity and prevalence of parasite infections. Because the house sparrow lost its native parasites when colonizing the American continents, the release from these natural enemies may have facilitated its invasion in the last two centuries. Our findings therefore reject the Novel Weapon Hypothesis and are concordant with the Enemy Release Hypothesis

The Effects of Copper Pollution on Fouling Assemblage Diversity: A Tropical-Temperate Comparison

BACKGROUND: The invasion of habitats by non-indigenous species (NIS) occurs at a global scale and can generate significant ecological, evolutionary, economic and social consequences. Estuarine and coastal ecosystems are particularly vulnerable to pollution from numerous sources due to years of human-induced degradation and shipping. Pollution is considered as a class of disturbance with anthropogenic roots and recent studies have concluded that high frequencies of disturbance may facilitate invasions by increasing the availability of resources. METHODOLOGY/PRINCIPAL FINDINGS: To examine the effects of heavy metal pollution as disturbance in shaping patterns of exotic versus native diversity in marine fouling communities we exposed fouling communities to different concentrations of copper in one temperate (Virginia) and one tropical (Panama) region. Diversity was categorized as total, native and non-indigenous and we also incorporated taxonomic and functional richness. Our findings indicate that total fouling diversity decreased with increasing copper pollution, whether taxonomic or functional diversity is considered. Both native and non-indigenous richness decreased with increasing copper concentrations at the tropical site whereas at the temperate site, non-indigenous richness was too low to detect any effect. CONCLUSIONS/SIGNIFICANCE: Non-indigenous richness decreased with increasing metal concentrations, contradicting previous investigations that evaluate the influence of heavy metal pollution on diversity and invasibility of fouling assemblages. These results provide first insights on how the invasive species pool in a certain region may play a key role in the disturbance vs. non-indigenous diversity relationship

The impact of conservation-driven translocations on blood parasite prevalence in the Seychelles warbler

Introduced populations often lose the parasites they carried in their native range, but little is known about which processes may cause parasite loss during host movement. Conservation-driven translocations could provide an opportunity to identify the mechanisms involved. Using 3,888 blood samples collected over 22 years, we investigated parasite prevalence in populations of Seychelles warblers (Acrocephalus sechellensis) after individuals were translocated from Cousin Island to four new islands (Aride, Cousine, Denis and Frégate). Only a single parasite (Haemoproteus nucleocondensus) was detected on Cousin (prevalence = 52%). This parasite persisted on Cousine (prevalence = 41%), but no infection was found in individuals hatched on Aride, Denis or Frégate. It is not known whether the parasite ever arrived on Aride, but it has not been detected there despite 20 years of post-translocation sampling. We confirmed that individuals translocated to Denis and Frégate were infected, with initial prevalence similar to Cousin. Over time, prevalence decreased on Denis and Frégate until the parasite was not found on Denis two years after translocation, and was approaching zero prevalence on Frégate. The loss (Denis) or decline (Frégate) of H. nucleocondensus, despite successful establishment of infected hosts, must be due to factors affecting parasite transmission on these islands

Mapping the evidence for the prevention and treatment of eating disorders in young people

ABSTRACT: Eating disorders often develop during adolescence and young adulthood, and are associated with significant psychological and physical burden. Identifying evidence-based interventions is critical and there is need to take stock of the extant literature, to inform clinical practice regarding well-researched interventions and to direct future research agendas by identifying gaps in the evidence base. AIM: To investigate and quantify the nature and distribution of existing high-quality research on the prevention and treatment of eating disorders in young people using evidence mapping methodology. METHOD: A systematic search for prevention and treatment intervention studies in adolescents and young adults (12-25 years) was conducted using EMBASE, PSYCINFO and MEDLINE. Studies were screened and mapped according to disorder, intervention modality, stage of eating disorder and study design. Included studies were restricted to controlled trials and systematic reviews published since 1980. RESULTS: The eating disorders evidence map included 197 trials and 22 systematic reviews. Prevention research was dominated by trials of psychoeducation (PE). Bulimia nervosa (BN) received the most attention in the treatment literature, with cognitive behavioural therapy (CBT) and antidepressants the most common interventions. For anorexia nervosa (AN), family based therapy (FBT) was the most studied. Lacking were trials exploring treatments for binge eating disorder (BED) and eating disorder not otherwise specified (EDNOS). Relapse prevention strategies were notably absent across the eating disorders. CONCLUSIONS: Despite substantial literature devoted to the prevention and treatment of eating disorders in young people, the evidence base is not well established and significant gaps remain. For those identified as being at-risk, there is need for prevention research exploring strategies other than passive PE. Treatment interventions targeting BED and EDNOS are required, as are systematic reviews synthesising BN treatment trials (e.g., CBT, antidepressants). FBTs for AN require investigation against other validated psychological interventions, and the development of relapse prevention strategies is urgently required. By systematically identifying existing interventions for young people with eating disorders and exposing gaps in the current literature, the evidence map can inform researchers, funding bodies and policy makers as to the opportunities for future research

Biologia Acuática Núm. 29 (2014)

Este número contiene los resúmenes de los trabajos presentados en el VI Congreso Argentino de Limnología: Agua, Ambiente y Sociedad. Se exponen avances en las  investigaciones limnológicas y su potencial transferencia a la sociedad orientados a mejorar el manejo y  preservación de los ambientes acuáticos y sus recursos a partir de un enfoque diverso e integral. Su  principal propósito es abrir un ámbito de debate sobre temas relevantes como los relacionados con la calidad del agua y del hábitat de lagos, lagunas, embalses, ríos y estuarios, la conservación de la biodiversidad y de la integridad biótica y ecológica de los ecosistemas acuáticos

Equity LA II. Impacto de las estrategias de integración de la atención en redes de servicios de salud de América Latina. Resultados comparativos 2015/2017

Equity LA II es un proyecto de investigación multicéntrico cuyo objetivo es evaluar la efectividad de diferentes estrategias de integración de la atención en la mejora de la coordinación y la calidad de la atención en diferentes redes integradas de servicios de salud (RISS) en seis países de América Latina: Colombia, Brasil, Argentina, Chile, México y Uruguay. En Argentina, el proyecto se desarrolló en la red de servicios de salud municipal de la ciudad de Rosario. Equity LA II adopta un enfoque innovador de investigación – acción, con un diseño cuasi – experimental. La investigación se desarrolló en cuatro fases, entre los años 2013-2019. En la fase 1 se desarrolló un estudio de línea de base con un componente cualitativo y otro cuantitativo, para identificar los problemas de coordinación existentes; en la fase 2 se diseñó e implementó una intervención para mejorar los problemas identificados en la fase previa, en la fase 3 se realizó una evaluación (cuantitativa-cualitativa) de la intervención implementada y la fase 4 se centra en el estudio comparativo internacional entre los 6 países participantes. La presente publicación tiene como objetivo sistematizar y difundir los resultados comparativos de las encuestas realizadas en 2015 (línea de base) y 2017 (evaluación) a médicos, para conocer los cambios en las experiencias sobre la coordinación de la atención y a usuarios, para conocer los cambios en sus opiniones sobre la continuidad de la atención, en las dos subredes en estudio. Así mismo presenta los cambios más relevantes implementados en la red en materia de coordinación, durante los años 2015 – 2017, desde la perspectiva de diferentes actores entrevistados.Fil: Maestría en Salud Pública, Centro de Estudios Interdisciplinarios. Universidad Nacional de Rosario; Argentin

Aging and Psychological Well-Being: The Possible Role of Inhibition Skills

(1) Background: Psychological well-being (PWB) is a multidimensional construct which is a key protective factor against chronic diseases in older adults. Numerous psychological and cognitive factors can influence older people’s PWB. However, while most studies have explored the effect of general cognition, only a few investigated the role of specific cognitive functions such as the efficiency of executive functions. Thus, the present study aimed to directly explore the relationships between PWB, age, and the core executive functions (namely working memory, flexibility, and inhibition). (2) Methods: A sample of 51 healthy older adults (age range: 60–88) were enrolled and tested both for PWB (by Ryff’s psychological well-being scale) and the core executive functions (by the Digit span backward, the Trail Making Test, and the Stroop test). (3) Results: Age and inhibitory skills are negatively correlated to the personal growth subscale of the PWB scale. Moreover, a hierarchical regression analysis showed that inhibition, but not working memory and flexibility, predicted the sense of continued growth and development (personal growth) of older adults, even after controlling for age and educational levels. Limitations and implications for future research and prevention interventions are discussed

Aging and Psychological Well-Being: The Possible Role of Inhibition Skills

(1) Background: Psychological well-being (PWB) is a multidimensional construct which is a key protective factor against chronic diseases in older adults. Numerous psychological and cognitive factors can influence older people’s PWB. However, while most studies have explored the effect of general cognition, only a few investigated the role of specific cognitive functions such as the efficiency of executive functions. Thus, the present study aimed to directly explore the relationships between PWB, age, and the core executive functions (namely working memory, flexibility, and inhibition). (2) Methods: A sample of 51 healthy older adults (age range: 60–88) were enrolled and tested both for PWB (by Ryff’s psychological well-being scale) and the core executive functions (by the Digit span backward, the Trail Making Test, and the Stroop test). (3) Results: Age and inhibitory skills are negatively correlated to the personal growth subscale of the PWB scale. Moreover, a hierarchical regression analysis showed that inhibition, but not working memory and flexibility, predicted the sense of continued growth and development (personal growth) of older adults, even after controlling for age and educational levels. Limitations and implications for future research and prevention interventions are discussed