4,187 research outputs found

    Taxonomic review of the Neotropical Tetragonoderus quadriguttatus assemblage (Coleoptera: Carabidae: Cyclosomini) with description of T. deuvei, new species, and new West Indian and Nearctic locality records

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    The Tetragonoderus (Peronoscelis) quadriguttatus assemblage is a postulated monophyletic part of the intersectus complex. This assemblage is characterized against a background that includes review of a classification of the genus and comparison, in the form of a key, to other unrelated Western Hemisphere genera that share elongate tibial spurs with Tetragonoderus Dejean. The principal, easily observed feature that unites the three members (T. laevigatus Chaudoir, 1876; T. deuvei, new species (type locality: Cuijaba, Mato Grosso, Brazil), and T. quadriguttatus Dejean) of the quadriguttatus assemblage is the four-spotted elytra (two spots per elytron). These species are treated in detail, including key, synonymy (as required), comparisons, description (external and male genitalic features), habitat (if known), locality data, and geographical range map. Also, T. subfasciatus Putzeys, 1846, the elytral color pattern of whose members may be confused with the spotted pattern of the quadriguttatus assemblage, is treated similarly. The following new synonymies were established: T. quadriguttatus Dejean 1829 = T. columbicus Steinheil 1875 = T. lacordairei Chaudoir 1876 = T. tetragrammus Chaudoir 1876; and T. laevigatus Chaudoir 1876 = T. chaudoiri Liebke 1928 (replacement name for the junior homonym, T. unicolor Chaudoir, 1876). Lectotypes are designated for T. unicolor Chaudoir, T. lacordairei Chaudoir, and T. subfasciatus Putzeys. A neotype is designated for T. quadriguttatus Dejean. New distribution records in the West Indies for T. quadriguttatus are recorded for the islands of Grand Cayman, Jamaica and Hispaniola. These records may be the result of recent natural overseas dispersal from northern South America, or they may be the result of human-mediated accidental introduction, or a combination of both. The southern Floridian (Nearctic) records for T. laevigatus probably represent a recent accidental introduction through commerce, followed by dispersal through flights of adults

    A taxonomic review of the subtribe Pericalina (Coleoptera: Carabidae: Lebiini) in the Western hemisphere : with descriptions of new species and notes about classification and zoogeography

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    A taxonomic review of the lebiine sub tribe Pericalina in the Western Hemisphere, this paper includes a treatment of the genus-groups, a key to the genera, keys to subgenera, species groups, and species of each polybasic genus, descriptions of new species and new subgenera, new locality records for previously described species, re-rankings, and new synonymy. In total, 111 species and subspecies are treated, 26 of which are described as new

    A taxonomic review of species of the Neotropical pericaline genus Oreodicastes Maindron, 1905 (Coleoptera: Carabidae: Lebiini)

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    Based on adult character states, a key is provided to the seven known species of Oreodicastes Maindron 1905 (type species Oxyglossus subcyaneus Chaudoir 1843). Two new species (with type locality) are described: O. virginia (Fa zenda dos Campos, Virginia, state of Minas Gerais, Brazil) and O. zikani (Macieiras, Itatiaia, state of Rio de Janeiro, Brazil)

    Los Platynini (Coleoptera: Carabidae) de Colombia

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    La familia Carabidae es uno de los grupos de coleópteros más grandes en el Mundo, con alrededor de 40000 especies (Erwin 1991), de las cuales 8000 están en la Región Neotropical (Erwin 2003). La familia hace parte del suborden Adephaga y junto con Trachypachidae conforman la subdivisión Geadephaga (Beutel 1998). Estos insectos son básicamente depredadores y ocupan una variedad de hábitats, como ambientes de agua dulce, playas de mar, hendiduras en rocas, cavernas, glaciares de alta montaña, desde el subsuelo a las copas de los árboles (Erwin 1991). Los carábidos son uno de los taxones mejor estudiados debido a su diversidad, larga historia evolutiva, amplio espectro de comportamiento y sensibilidad a cambios ambientales (Erwin et al.1979; Thiele 1977); se han utilizado en trabajos biogeográficos (Erwin et al. 1979), estudios ecológicos (Lövei & Sunderland 1996) y de fragmentación y monitoreos de hábitat (Davies & Margules 1998; Thacker 1996)

    Synopsis of the genera and subgenera of the tribe Peleciini, and revision of the neotropical and oriental species (Coleoptera: Carabidae)

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    Phylogenetic analysis of structural features of adults shows that the tribe Peleciini comprises eight genera, grouped in two subtribes: the southeastern Australian Agonicina (new status), including Pseudagonica Moore, 1960 (type species P. nitida Moore, 1960) and Agonica Sloane, 1920 (type species A. simsoni Sloane, 1920); and the Inabresian Peleciina (new status, with Peleciini and Disphaericini of authors), including the Neotropical Eripus Dejean, 1829 (type species E. scydmaenoides Dejean, 1829), Pelecium Kirby, 1817 (type species P. cyanipes Kirby, 1817), and Stricteripus, new genus (type species Pelecium peruvianum Straneo, 1953), the Oriental Ardistomopsis, new genus (type species Disphaericus myrmex, Andrewes, 1923), and the Afrotropical Dyschiridium Chaudoir, 1861 (type species D. ebeninum Chaudoir, 1861) and Disphaericus Waterhouse, 1842 (type species D. gambianus Waterhouse, 1842). A key is provided to distinguish among these genera, and the structural features of each genus are described and illustrated, with habitus and SEM photographs. For the genera Eripus, Pelecium, Stricteripus, and Ardistomopsis, the species are keyed and characterized in terms of structural features and geographical distribution, and illustrations of habitus and range maps are provided. Application of names is based on study of type material

    Citrate and malonate increase microbial activity and alter microbial community composition in uncontaminated and diesel-contaminated soil microcosms

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    Petroleum hydrocarbons (PHCs) are among the most prevalent sources of environmental contamination. It has been hypothesized that plant root exudation of low molecular weight organic acid anions (carboxylates) may aid degradation of PHCs by stimulating heterotrophic microbial activity. To test their potential implication for bioremediation, we applied two commonly exuded carboxylates (citrate and malonate) to uncontaminated and diesel-contaminated microcosms (10 000 mg kg−1; aged 40 days) and determined their impact on the microbial community and PHC degradation. Every 48 h for 18 days, soil received 5 µmol g−1 of (i) citrate, (ii) malonate, (iii) citrate + malonate or (iv) water. Microbial activity was measured daily as the flux of CO2. After 18 days, changes in the microbial community were assessed by a community-level physiological profile (CLPP) and 16S rRNA bacterial community profiles determined by denaturing gradient gel electrophoresis (DGGE). Saturated PHCs remaining in the soil were assessed by gas chromatography–mass spectrometry (GC-MS). Cumulative soil respiration increased 4- to 6-fold with the addition of carboxylates, while diesel contamination resulted in a small, but similar, increase across all carboxylate treatments. The addition of carboxylates resulted in distinct changes to the microbial community in both contaminated and uncontaminated soils but only a small increase in the biodegradation of saturated PHCs as measured by the n-C17 : pristane biomarker. We conclude that while the addition of citrate and malonate had little direct effect on the biodegradation of saturated hydrocarbons present in diesel, their effect on the microbial community leads us to suggest further studies using a variety of soils and organic acids, and linked to in situ studies of plants, to investigate the role of carboxylates in microbial community dynamics

    Low molecular weight organic anions (carboxylates) increase microbial activity and alter microbial community composition in uncontaminated and diesel contaminated soil

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    Petroleum hydrocarbons (PHCs) are among the most prevalent sources of environmental contamination. It has been hypothesized that plant root exudation of low molecular weight organic acid anions (carboxylates) may aid degradation of PHCs by stimulating heterotrophic microbial activity. We, therefore, applied two commonly-exuded carboxylates (citrate and malonate) to uncontaminated and diesel contaminated microcosms (10,000 mg kg–1; aged 40 days) to determine their impact on the microbial community and PHC degradation. Every 48 hours for 18 days, soil received 5 μmol g–1 of i) citrate, ii) malonate, iii) citrate + malonate or iv) water. Microbial activity was measured daily as the flux of CO2. After 18 days, changes in the microbial community were assessed by community level physiological profiles and 16S rRNA bacterial community profiles determined by denaturing gradient gel electrophoresis. Saturated PHCs remaining in the soil were assessed by GCMS. Cumulative soil respiration increased four- to six-fold with the addition of carboxylates, while diesel contamination resulted in a small, but similar, increase across all carboxylate treatments. The addition of carboxylates resulted in distinct changes to the microbial community, but only a small decrease in the n-C17: pristane biomarker. We conclude that carboxylate addition can increase microbial activity and modify the microbial community in both uncontaminated and diesel-contaminated soils. The impact of these changes on PHC biodegradation and rhizosphere processes, more generally, merits further research

    Harvard Personal Genome Project: lessons from participatory public research

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    Background: Since its initiation in 2005, the Harvard Personal Genome Project has enrolled thousands of volunteers interested in publicly sharing their genome, health and trait data. Because these data are highly identifiable, we use an ‘open consent’ framework that purposefully excludes promises about privacy and requires participants to demonstrate comprehension prior to enrollment. Discussion Our model of non-anonymous, public genomes has led us to a highly participatory model of researcher-participant communication and interaction. The participants, who are highly committed volunteers, self-pursue and donate research-relevant datasets, and are actively engaged in conversations with both our staff and other Personal Genome Project participants. We have quantitatively assessed these communications and donations, and report our experiences with returning research-grade whole genome data to participants. We also observe some of the community growth and discussion that has occurred related to our project. Summary We find that public non-anonymous data is valuable and leads to a participatory research model, which we encourage others to consider. The implementation of this model is greatly facilitated by web-based tools and methods and participant education. Project results are long-term proactive participant involvement and the growth of a community that benefits both researchers and participants

    Misregulation of mitochondria-lysosome contact dynamics in Charcot-Marie-Tooth Type 2B disease Rab7 mutant sensory peripheral neurons

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    Inter-organelle contact sites between mitochondria and lysosomes mediate the crosstalk and bidirectional regulation of their dynamics in health and disease. However, mitochondria-lysosome contact sites and their misregulation have not been investigated in peripheral sensory neurons. Charcot-Marie-Tooth type 2B disease is an autosomal dominant axonal neuropathy affecting peripheral sensory neurons caused by mutations in the GTPase Rab7. Using live super-resolution and confocal time-lapse microscopy, we showed that mitochondria-lysosome contact sites dynamically form in the soma and axons of peripheral sensory neurons. Interestingly, Charcot-Marie-Tooth type 2B mutant Rab7 led to prolonged mitochondria-lysosome contact site tethering preferentially in the axons of peripheral sensory neurons, due to impaired Rab7 GTP hydrolysis-mediated contact site untethering. We further generated a Charcot-Marie-Tooth type 2B mutant Rab7 knock-in mouse model which exhibited prolonged axonal mitochondria-lysosome contact site tethering and defective downstream axonal mitochondrial dynamics due to impaired Rab7 GTP hydrolysis as well as fragmented mitochondria in the axon of the sciatic nerve. Importantly, mutant Rab7 mice further demonstrated preferential sensory behavioral abnormalities and neuropathy, highlighting an important role for mutant Rab7 in driving degeneration of peripheral sensory neurons. Together, this study identifies an important role for mitochondria-lysosome contact sites in the pathogenesis of peripheral neuropathy
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