100 research outputs found
Microbiome dynamics during the HI-SEAS IV mission, and implications for future crewed missions beyond Earth.
Background: Human health is closely interconnected with its microbiome. Resilient microbiomes in, on, and around the human body will be key for safe and successful long-term space travel. However, longitudinal dynamics of microbiomes inside confined built environments are still poorly understood. Herein, we used the Hawaii Space Exploration Analog and Simulation IV (HI-SEAS IV) mission, a 1 year-long isolation study, to investigate microbial transfer between crew and habitat, in order to understand adverse developments which may occur in a future outpost on the Moon or Mars.
Results: Longitudinal 16S rRNA gene profiles, as well as quantitative observations, revealed significant differences in microbial diversity, abundance, and composition between samples of the built environment and its crew. The microbiome composition and diversity associated with abiotic surfaces was found to be rather stable, whereas the microbial skin profiles of individual crew members were highly dynamic, resulting in an increased microbiome diversity at the end of the isolation period. The skin microbiome dynamics were especially pronounced by a regular transfer of the indicator species Methanobrevibacter between crew members within the first 200 days. Quantitative information was used to track the propagation of antimicrobial resistance in the habitat. Together with functional and phenotypic predictions, quantitative and qualitative data supported the observation of a delayed longitudinal microbial homogenization between crew and habitat surfaces which was mainly caused by a malfunctioning sanitary facility.
Conclusions: This study highlights main routes of microbial transfer, interaction of the crew, and origins of microbial dynamics in an isolated environment. We identify key targets of microbial monitoring, and emphasize the need for defined baselines of microbiome diversity and abundance on surfaces and crew skin. Targeted manipulation to counteract adverse developments of the microbiome could be a highly important strategy to ensure safety during future space endeavors
Arachnida at "Reserva Ducke", Central Amazonia/Brazil
The class Arachnida contains 11 recent orders: Acari, Amblypygi, Araneae, Opiliones, Palpigradi, Pseudoscorpiones, Ricinulei, Schizomida, Scorpiones, Solifugae and Uropygi (Thelyphonida). In total, >570 families, >9165 genera and >93455 species are known world-wide. More than 136 families, >482 genera and >1547 described species occur in Amazonia. Data show, that almost one-fourth of the families presently known in the Arachnida and about 2% of the worlds described species are represented in Amazonia. In the forest reserve 'Reserva Ducke' near Manaus, the Acari-Oribatida represent 45 families, 72 genera and 35 described species, the Aranea 30 families, 143 genera and 295 described species, the Opiliones 5 families, 7 genera and 8 decribed species, the Scorpiones 2 families, 4 genera and 5 described species, the Pseudoscorpiones 6 families, 11 genera, and 15 described species, the Schizomida, 1 family, 2 genera and 2 described species, and the Amblypygi, Palpigradi, Solifugae and Uropygi (Thelyphonida) one species each. Most names are liste
Ranking protected areas in the Azores using standardised sampling of soil epigean arthropods
Copyright © Springer 2005.Nineteen areas in seven of the nine Azorean islands were evaluated for species diversity and rarity based on soil epigean arthropods. Fifteen out of the 19 study areas are managed as Natural Forest Reserves and the remaining four were included due to their importance as indigenous forest cover. Four of the 19 areas are not included in the European Conservation network, NATURA 2000. Two sampling replicates were run per study area, and a total of 191 species were collected; 43 of those species (23%) are endemic to the archipelago and 12 have yet to be described. To produce an unbiased multiple-criteria index (importance value for conservation, IV-C) incorporating diversity and rarity based indices, an iterative partial multiple regression analysis was performed. In addition, an irreplaceability index and the complementarity method (using both optimisation and heuristic methods) were used for priority-reserves analyses. It was concluded that at least one well-managed reserve per island is absolutely necessary to have a good fraction of the endemic arthropods preserved. We found that for presence/absence data the suboptimal complementarity algorithm provides solutions as good as the optimal algorithm. For abundance data, optimal solutions indicate that most reserves are needed if we want that at least 50% of endemic arthropod populations are represented in a minimum set of reserves. Consistently, two of the four areas not included in the NATURA 2000 framework were considered of high priority, indicating that vascular plants and bird species used to determine NATURA 2000 sites are not good surrogates of arthropod diversity in the Azores. The most irreplaceable reserves are those located in older islands, which indicates that geological history plays an important role in explaining faunal diversity of arthropods in the Azores. Based both on the uniqueness of species composition and high species richness, conservation efforts should be focused on the unmanaged Pico Alto region in the archipelago’s oldest island, Santa Maria
New records and detailed distribution and abundance of selected arthropod species collected between 1999 and 2011 in Azorean native forests
[Background] In this contribution we present detailed distribution and abundance data for arthropod species identified during the BALA ¿ Biodiversity of Arthropods from the Laurisilva of the Azores (1999-2004) and BALA2 projects (2010-2011) from 18 native forest fragments in seven of the nine Azorean islands (all excluding Graciosa and Corvo islands, which have no native forest left).[New information] Of the total 286 species identified, 81% were captured between 1999 and 2000, a period during which only 39% of all the samples were collected. On average, arthropod richness for each island increased by 10% during the time frame of these projects. The classes Arachnida, Chilopoda and Diplopoda represent the most remarkable cases of new island records, with more than 30% of the records being novelties. This study stresses the need to expand the approaches applied in these projects to other habitats in the Azores, and more importantly to other less surveyed taxonomic groups (e.g. Diptera and Hymenoptera). These steps are fundamental for getting a more accurate assessment of biodiversity in the archipelago.AMCS was supported by a Marie Curie Intra-European Fellowship (IEF 331623 ‘COMMSTRUCT’) and by a Juan de la Cierva Fellowship (IJCI-2014-19502) funded by the Spanish ‘Ministerio de Economía y Competitividad’.Peer Reviewe
Factors associated with diversity, quantity and zoonotic potential of ectoparasites on urban mice and voles
Wild rodents are important hosts for tick larvae but co-infestations with other mites and insects are largely neglected. Small rodents were trapped at four study sites in Berlin, Germany, to quantify their ectoparasite diversity. Host-specific, spatial and temporal occurrence of ectoparasites was determined to assess their influence on direct and indirect zoonotic risk due to mice and voles in an urban agglomeration. Rodent-associated arthropods were diverse, including 63 species observed on six host species with an overall prevalence of 99%. The tick Ixodes ricinus was the most prevalent species, found on 56% of the rodents. The trapping location clearly affected the presence of different rodent species and, therefore, the occurrence of particular host-specific parasites. In Berlin, fewer temporary and periodic parasite species as well as non-parasitic species (fleas, chiggers and nidicolous Gamasina) were detected than reported from rural areas. In addition, abundance of parasites with low host-specificity (ticks, fleas and chiggers) apparently decreased with increasing landscape fragmentation associated with a gradient of urbanisation. In contrast, stationary ectoparasites, closely adapted to the rodent host, such as the fur mites Myobiidae and Listrophoridae, were most abundant at the two urban sites. A direct zoonotic risk of infection for people may only be posed by Nosopsyllus fasciatus fleas, which were prevalent even in the city centre. More importantly, peridomestic rodents clearly supported the life cycle of ticks in the city as hosts for their subadult stages. In addition to trapping location, season, host species, body condition and host sex, infestation with fleas, gamasid Laelapidae mites and prostigmatic Myobiidae mites were associated with significantly altered abundance of I. ricinus larvae on mice and voles. Whether this is caused by predation, grooming behaviour or interaction with the host immune system is unclear. The present study constitutes a basis to identify interactions and vector function of rodent-associated arthropods and their potential impact on zoonotic diseases
A medium-spatial scale distribution pattern of pseudoscorpionida (arachnida) in a gradient of topography (altitude and inclination), soil factors, and litter in a central Amazonia forest reserve, Brazil
In Amazonia, nothing is known about the distribution of the invertebrates on a medium-spatial scale pattern. In a trail system of 64 km2 at Ducke Reserve, we sampled 72 transects using the hand-sorting method and Berlese-Tullgren extraction. The reserve possesses ecosystems of "terra-firme" forest and the trail system represents a gradient of topographic soil factors and vegetation, avoiding categorizations. Considering the abundance and diversity of Pseudoscorpionida, we investigated the relation of the community to environmental factors tested (topography, clay percentage, litter, and soil pH), to the two major drainage basins of the reserve, and if these invertebrates can be used as biological indicators to monitor changes. We registered two species for the first time in the reserve, increasing the known diversity to 17 species. The lack of correlation with the predictor variables and the large home range, indicate that pseudoscorpions are not good biological indicators in the reserve. As the eastern and western watersheds are not separate management units for the community, our results show that they are generalist predators. In spite of our results and lack of knowledge concerning their biology, life history and taxonomy, pseudoscorpions are cosmopolitan and easy to find and measure. Compared with previous studies in the reserve, they have a consistent pattern of abundance and diversity throughout the years showing the stability of the community which can be checked mainly by comparison with environmental changes that would occur in the reserve. An investigation on a medium-spatial scale pattern and over a long-term period including other habitats, and also other predictor variables, like humidity, the structure of the vegetation and canopy closure, will be necessary to reinforce the observed tendencies
Molecular phylogeny of the subfamily Stevardiinae Gill, 1858 (Characiformes: Characidae): classification and the evolution of reproductive traits
Abstract
Background
The subfamily Stevardiinae is a diverse and widely distributed clade of freshwater fishes from South and Central America, commonly known as “tetras” (Characidae). The group was named “clade A” when first proposed as a monophyletic unit of Characidae and later designated as a subfamily. Stevardiinae includes 48 genera and around 310 valid species with many species presenting inseminating reproductive strategy. No global hypothesis of relationships is available for this group and currently many genera are listed as incertae sedis or are suspected to be non-monophyletic.
Results
We present a molecular phylogeny with the largest number of stevardiine species analyzed so far, including 355 samples representing 153 putative species distributed in 32 genera, to test the group’s monophyly and internal relationships. The phylogeny was inferred using DNA sequence data from seven gene fragments (mtDNA: 12S, 16S and COI; nuclear: RAG1, RAG2, MYH6 and PTR). The results support the Stevardiinae as a monophyletic group and a detailed hypothesis of the internal relationships for this subfamily.
Conclusions
A revised classification based on the molecular phylogeny is proposed that includes seven tribes and also defines monophyletic genera, including a resurrected genus Eretmobrycon, and new definitions for Diapoma, Hemibrycon, Bryconamericus sensu stricto, and Knodus sensu stricto, placing some small genera as junior synonyms. Inseminating species are distributed in several clades suggesting that reproductive strategy is evolutionarily labile in this group of fishes.http://deepblue.lib.umich.edu/bitstream/2027.42/134621/1/12862_2015_Article_403.pd
New records and detailed distribution and abundance of selected arthropod species collected between 1999 and 2011 in Azorean native forests.
Of the total 286 species identified, 81% were captured between 1999 and 2000, a period
during which only 39% of all the samples were collected. On average, arthropod richness
for each island increased by 10% during the time frame of these projects. The classes
Arachnida, Chilopoda and Diplopoda represent the most remarkable cases of new island
records, with more than 30% of the records being novelties. This study stresses the need
to expand the approaches applied in these projects to other habitats in the Azores, and
more importantly to other less surveyed taxonomic groups (e.g. Diptera and Hymenoptera).
These steps are fundamental for getting a more accurate assessment of biodiversity in the
archipelago
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