32 research outputs found

    The relationship between morphological and behavioral mimicry in hover flies (Diptera: Syrphidae).

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    Palatable (Batesian) mimics of unprofitable models could use behavioral mimicry to compensate for the ease with which they can be visually discriminated or to augment an already close morphological resemblance. We evaluated these contrasting predictions by assaying the behavior of 57 field-caught species of mimetic hover flies (Diptera: Syrphidae) and quantifying their morphological similarity to a range of potential hymenopteran models. A purpose-built phylogeny for the hover flies was used to control for potential lack of independence due to shared evolutionary history. Those hover fly species that engage in behavioral mimicry (mock stinging, leg waving, wing wagging) were all large wasp mimics within the genera Spilomyia and Temnostoma. While the behavioral mimics assayed were good morphological mimics, not all good mimics were behavioral mimics. Therefore, while the behaviors may have evolved to augment good morphological mimicry, they do not advantage all good mimics

    Effectiveness of psychotherapeutic, pharmacological, and combined treatments for chronic depression: a systematic review (METACHRON)

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    <p>Abstract</p> <p>Background</p> <p>Chronic depressions represent a substantial part of depressive disorders and are associated with severe consequences. Several studies were performed addressing the effectiveness of psychotherapeutic, pharmacological, and combined treatments for chronic depressions. Yet, a systematic review comparing the effectiveness of multiple treatment options and considering all subtypes of chronic depressions is still missing.</p> <p>Methods/Design</p> <p>Aim of this project is to summarize empirical evidence on efficacy and effectiveness of treatments for chronic depression by means of a systematic review. The primary objectives of the study are to examine, which interventions are effective; to examine, if any differences in effectiveness between active treatment options exist; and to find possible treatment effect modifiers. Psychotherapeutic, pharmacological, and combined treatments will be considered as experimental interventions and no treatment, wait-list, psychological/pharmacological placebo, treatment as usual, and other active treatments will be seen as comparators. The population of patients will include adults with chronic major depression, dysthymia, double depression, or recurrent depression without complete remission between episodes. Outcomes of the analyses are depressive symptoms, associated consequences, adverse events, and study discontinuation. Only randomized controlled trials will be considered.</p> <p>Discussion</p> <p>Given the high prevalence and serious consequences of chronic depression and a considerable amount of existing primary studies addressing the effectiveness of different treatments the present systematic review may be of high relevance. Special attention will be given to the use of current methodological standards. Findings are likely to provide crucial information that may help clinicians to choose the appropriate treatment for chronically depressed patients.</p

    Anchored enrichment dataset for true flies (order Diptera) reveals insights into the phylogeny of flower flies (family Syrphidae)

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    Background: Anchored hybrid enrichment is a form of next-generation sequencing that uses oligonucleotide probes to target conserved regions of the genome flanked by less conserved regions in order to acquire data useful for phylogenetic inference from a broad range of taxa. Once a probe kit is developed, anchored hybrid enrichment is superior to traditional PCR-based Sanger sequencing in terms of both the amount of genomic data that can be recovered and effective cost. Due to their incredibly diverse nature, importance as pollinators, and historical instability with regard to subfamilial and tribal classification, Syrphidae (flower flies or hoverflies) are an ideal candidate for anchored hybrid enrichment-based phylogenetics, especially since recent molecular phylogenies of the syrphids using only a few markers have resulted in highly unresolved topologies. Over 6200 syrphids are currently known and uncovering their phylogeny will help us to understand how these species have diversified, providing insight into an array of ecological processes, from the development of adult mimicry, the origin of adult migration, to pollination patterns and the evolution of larval resource utilization. Results: We present the first use of anchored hybrid enrichment in insect phylogenetics on a dataset containing 30 flower fly species from across all four subfamilies and 11 tribes out of 15. To produce a phylogenetic hypothesis, 559 loci were sampled to produce a final dataset containing 217,702 sites. We recovered a well resolved topology with bootstrap support values that were almost universally >95 %. The subfamily Eristalinae is recovered as paraphyletic, with the strongest support for this hypothesis to date. The ant predators in the Microdontinae are sister to all other syrphids. Syrphinae and Pipizinae are monophyletic and sister to each other. Larval predation on soft-bodied hemipterans evolved only once in this family. Conclusions: Anchored hybrid enrichment was successful in producing a robustly supported phylogenetic hypothesis for the syrphids. Subfamilial reconstruction is concordant with recent phylogenetic hypotheses, but with much higher support values. With the newly designed probe kit this analysis could be rapidly expanded with further sampling, opening the door to more comprehensive analyses targeting problem areas in syrphid phylogenetics and ecology.Peer reviewe

    Higher quality of life and lower depression for people on art in Uganda as compared to a community control group

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    Provision of antiretroviral treatment (ART) to people living with HIV (PLWH) has increased globally. Research measuring whether ART restores subjective well-being to "normal" levels is lacking, particularly in resource limited settings. The study objectives are to compare quality of life and depression symptoms for PLWH on ART to a general community population and to explore factors to explain these differences, including socio-economic status and the impact of urban or rural residence. PLWH on ART (n = 263) were recruited from ART delivery sites and participants not on ART (n = 160) were recruited from communities in Wakiso District, Uganda. Participants were interviewed using the translated World Health Organisation Quality of Life brief measure, the Hopkins Symptom Checklist depression section, and questions about socioeconomic status, residence as urban or rural and, for PLWH on ART, self-reported adherence and use of HIV counselling. Compared to the community sample and controlling for location of residence, PLWH on ART had significantly higher quality of life (QOL) for physical, psychological and environment domains, but not the social domain. These differences were not due to socio-economic status alone. Depression scores were significantly lower for PLWH on ART. Both comparisons controlled for the effect of location of residence. People on ART self-reported high adherence and the majority had used HIV counselling services. Our findings show better QOL amongst PLWH on ART compared to a general community sample, which cannot be explained solely by differences in socio-economic status nor location of residence. The general community sample results point towards the challenges of life in this setting. Access to health services may underpin this difference and further research should explore this finding, in addition to identification of psychological mechanisms that relate to better QOL. ART provision infrastructure has clear benefits. Further work should consider sustainability and replication for other health conditions. © 2014 Martin et al

    A comparative analysis of the evolution of imperfect mimicry.

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    Although exceptional examples of adaptation are frequently celebrated, some outcomes of natural selection seem far from perfect. For example, many hoverflies (Diptera: Syrphidae) are harmless (Batesian) mimics of stinging Hymenoptera. However, although some hoverfly species are considered excellent mimics, other species bear only a superficial resemblance to their models and it is unclear why this is so. To evaluate hypotheses that have been put forward to explain interspecific variation in the mimetic fidelity of Palearctic Syrphidae we use a comparative approach. We show that the most plausible explanation is that predators impose less selection for mimetic fidelity on smaller hoverfly species because they are less profitable prey items. In particular, our findings, in combination with previous results, allow us to reject several key hypotheses for imperfect mimicry: first, human ratings of mimetic fidelity are positively correlated with both morphometric measures and avian rankings, indicating that variation in mimetic fidelity is not simply an illusion based on human perception; second, no species of syrphid maps out in multidimensional space as being intermediate in appearance between several different hymenopteran model species, as the multimodel hypothesis requires; and third, we find no evidence for a negative relationship between mimetic fidelity and abundance, which calls into question the kin-selection hypothesis. By contrast, a strong positive relationship between mimetic fidelity and body size supports the relaxed-selection hypothesis, suggesting that reduced predation pressure on less profitable prey species limits the selection for mimetic perfection

    Argentinean Species of Chalarus Walker (Diptera: Pipunculidae): New Records and Description of Chalarus tani n. sp.

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    The Argentinean species of Chalarus Walker were studied. Pipunculidae adults belonging to four species, Chalarus chilensis Collin, Chalarus triramosus Rafael, Chalarus absonus Rafael and Chalarus tani n. sp. were described based on two male specimens collected in the La Rioja and Tucuman Provinces, northwestern region of Argentina. Chalarus absonus is recorded for the first time in Argentina. New distributional data and an identification key to the adult males of the Argentinean representatives are provided including figures. © 2012 Sociedade Entomológica do Brasil

    Pathogens, parasites, and parasitoids associated with bumble bees (Bombus spp.) from Uruguay

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    As elsewhere in the world, bumble bees play a vital role as pollinators in Uruguay, but knowledge on their health status is still limited. Between September 2012 and May 2013, 403 adult individuals of the two speciesof Bombus known for the country (Bombus atratus , Bombus bellicosus ) were collected in six localities.We found that 177 (119 B. atratus, 58 B. bellicosus ) were harboring one or two types of pathogens, parasites, or parasitoids.Identification of these natural enemies carried out by morphological or molecular procedures revealed the presence of two species of Microsporidia [Nosema ceranae (prevalence: 18.2 % in B. atratus; 44.9 % in B. bellicosus ),Tubulinosema pampeana (prevalence: 13 % in B. atratus )], two species of Nematoda [Sphaerularia bombi (prevalence: 40.4 % in B. atratus; 40% in B. bellicosus ) and an unidentified Mermithidae (prevalence: 0.8 % inB. bellicosus )], and one species of Diptera parasitoid (prevalence: 3.2 % in B. atratus ; 4.2 % in B. bellicosus ). Except N. ceranae , none of the other species have been previously reported in Uruguay.Fil: Plischuk, Santiago. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; ArgentinaFil: Salvarrey, Sheena. Universidad de la República. Facultad de Ciencias; UruguayFil: Arbulo, Natalia. Universidad de la República; UruguayFil: Santos, Estela. Universidad de la República. Facultad de Ciencias; UruguayFil: Skevington, Jeffrey H.. Canadian National Collection of Insects; CanadáFil: Kelso, Scott. Canadian National Collection of Insects; CanadáFil: Revainera, Pablo Damian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina. Universidad Nacional de Mar del Plata; ArgentinaFil: Maggi, Matías Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina. Universidad Nacional de Mar del Plata; ArgentinaFil: Invernizzi, Ciro. Universidad de la República. Facultad de Ciencias; UruguayFil: Lange, Carlos Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentin
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