Mitochondrial differentiation, introgression and phylogeny of species in the Tegenaria atrica group (Araneae, Agelenidae)

The relationships between the three members of the Tegenaria atrica group (T. atrica, T. saeva and T. gigantea) were examined with DNA sequence data from mitochondrial CO1, 16S rRNA, tRNAleu(CUN) and ND1 genes. Members of this group of large house spiders have overlapping distributions in western Europe and hybridize with each other to a variable degree. The close relatedness of all three species was supported by all analyses. T. saeva and T. gigantea are more closely affiliated than either is to T. atrica. Haplotypes clearly assignable to T. gigantea were also present in many specimens of T. saeva suggesting asymmetrical introgression of mtDNA from T. gigantea into T. saeva. Molecular clock calibrations (CO1) suggest that deeper divisions within the genus Tegenaria may be in excess of 10 million years old, and that the evolutionary history of the T. atrica group has been moulded by Quaternary glacial-interglacial cycles

Introduction to the Special Issue: An Overview of the Gulf of Mexico Research Initiative

Prior to the Deepwater Horizon (DWH) incident on April 20, 2010, in the Gulf of Mexico, the state of knowledge concerning oil in the sea was well summarized by the third National Research Council report (National Research Council, 2003). Since that report was published, several ongoing studies have examined spills in cold and shallow waters, for example, Peterson et al. (2003) and Wiens (2013) on the legacies and lessons of the 1989 Exxon Valdez oil spill. Oil exploration and production has moved further offshore and into much deeper water in recent decades. The DWH/Macondo blowout occurred in water over 1,000 m deep, in a relatively warm near-surface water environment, and in a region where naturally occurring seeps of oil are also common. Despite ongoing general oceanographic research in the Gulf of Mexico, establishment of ocean observing systems, and several programs funded by the US Bureau of Ocean Energy Management (BOEM, formerly Minerals Management Service), prior knowledge of oceanography in the Gulf proved to be inadequate, and not fully appropriate, for this unprecedented event, as observations in the vicinity of the spill rapidly demonstrated (see Overton et al. and Passow and Hetland in this issue). Major environmental events like the DWH spill trigger a legal process called Natural Resource Damage Assessment (NRDA) that brings together federal agencies, states, and Native American tribes to evaluate the impacts of the event on natural resources, in this case, along the nation’s coast. Because there were legal and procedural constraints on resulting field programs, data collection, and other research by US federal government agencies and their contractors as well as on BP investigations, a major program of independent scientific investigations was urgently needed. Fortunately, BP quickly established the Gulf of Mexico Research Initiative (GoMRI) to address this knowledge deficit, and GoMRI has been able to support unfettered and independent research (see Colwell). This article provides an overview of the science undertaken by the GoMRI program and its management

Intervento alla tavola rotonda "Dove sta andando la critica letteraria?"

Marginalità rispetto alle altre letterature e alle altre forme di comunicazione. È questa, secondo lo studioso, la condizione attuale della letteratura italiana nel sistema globalizzato. È necessario che l'interprete riscopra la sua triplice funzione - critico, filologo, storico della letteratura - per tentare di penetrare nel testo, anche grazie agli apporti fecondi della critica tematica e ai nuovi approcci interdisciplinari della comparatistica

Multiple uncontrolled conditions and blood pressure medication intensification: an observational study

Abstract Background Multiple uncontrolled medical conditions may act as competing demands for clinical decision making. We hypothesized that multiple uncontrolled cardiovascular risk factors would decrease blood pressure (BP) medication intensification among uncontrolled hypertensive patients. Methods We observed 946 encounters at two VA primary care clinics from May through August 2006. After each encounter, clinicians recorded BP medication intensification (BP medication was added or titrated). Demographic, clinical, and laboratory information were collected from the medical record. We examined BP medication intensification by presence and control of diabetes and/or hyperlipidemia. 'Uncontrolled' was defined as hemoglobin A1c ≥ for diabetes, BP ≥ 140/90 mmHg (≥ 130/80 mmHg if diabetes present) for hypertension, and low density lipoprotein cholesterol (LDL-c) ≥ 130 mg/dl (≥ 100 mg/dl if diabetes present) for hyperlipidemia. Hierarchical regression models accounted for patient clustering and adjusted medication intensification for age, systolic BP, and number of medications. Results Among 387 patients with uncontrolled hypertension, 51.4% had diabetes (25.3% were uncontrolled) and 73.4% had hyperlipidemia (22.7% were uncontrolled). The BP medication intensification rate was 34.9% overall, but higher in individuals with uncontrolled diabetes and uncontrolled hyperlipidemia: 52.8% overall and 70.6% if systolic BP ≥ 10 mmHg above goal. Intensification rates were lowest if diabetes or hyperlipidemia were controlled, lower than if diabetes or hyperlipidemia were not present. Multivariable adjustment yielded similar results. Conclusions The presence of uncontrolled diabetes and hyperlipidemia was associated with more guideline-concordant hypertension care, particularly if BP was far from goal. Efforts to understand and improve BP medication intensification in patients with controlled diabetes and/or hyperlipidemia are warranted.http://deepblue.lib.umich.edu/bitstream/2027.42/78266/1/1748-5908-5-55.xmlhttp://deepblue.lib.umich.edu/bitstream/2027.42/78266/2/1748-5908-5-55.pdfPeer Reviewe

Animals and Their Unicellular Ancestors

Animals belong to the Opisthokonta, one of the major divisions of the eukaryotic Tree of Life. This supergroup also includes other well?known groups such as fungi and choanoflagellates, in addition to some newly discovered unicellular taxa as the Ichthyosporea or the Filasterea. To unveil the origin of animal multicellularity, it is vital to understand the evolution of their single?celled relatives, as they might hold key genetic clues that might help us understand how the unicellular ancestors of animals became animals. Our current knowledge of unicellular animal relatives, their specific phylogenetic relationships and the role they might play in future research is being improved, thanks to molecular data

Discovering Diversity with High-Throughput Approaches: Introduction to a Virtual Symposium in The Biological Bulletin

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Mitochondrial genomes of Clymenella torquata (Maldanidae) and Riftia pachyptila (Siboglinidae) : evidence for conserved gene order in Annelida

Author Posting. © The Authors, 2004. This is the author's version of the work. It is posted here by permission of Society for Molecular Biology and Evolution for personal use, not for redistribution. The definitive version was published in Molecular Biology and Evolution 22 (2005): 210-222, doi:10.1093/molbev/msi008.Mitochondrial genomes are useful tools for inferring evolutionary history. However, many taxa are poorly represented by available data. Thus, to further understand the phylogenetic potential of complete mitochondrial genome sequence data in Annelida (segmented worms), we examined the complete mitochondrial sequence for Clymenella torquata (Maldanidae) and an estimated 80% of the sequence of Riftia pachyptila (Siboglinidae). These genomes have remarkably similar gene orders to previously published annelid genomes, suggesting that gene order is conserved across annelids. This result is interesting given the high variation seen in the closely related Mollusca and Brachiopoda. Phylogenetic analyses of DNA sequence, amino acid sequence and gene order all support the recent hypothesis that Sipuncula and Annelida are closely related. Our findings suggest that gene order data is of limited utility in annelids but that sequence data holds promise. Additionally, these genomes show AT bias (~66%) and codon usage biases, but have a typical gene complement for bilaterian mitochondrial genomes.Support by CICOR to RJM is gratefully acknowledged. This work was support by the National Science Foundation grants (DEB-0075618 and EAR-0120646) to KMH

Effect of silicon additions on structure and tribomechanical properties of sintered Al-40Sn composites

The structure, mechanical and tribological properties of sintered (Al-Si)-40Sn composites were investigated in the present study. The composite materials were obtained by the sintering of the briquettes made from mixtures of tin and aluminum (Al, Al-0.5Si or Al-12Si) powders. It was found that the hot densification of the sintered composites substantially increases strength and also makes much higher their wear resistant under dry friction against a steel counterbody

Opsin evolution in the Ambulacraria

Opsins - G-protein coupled receptors involved in photoreception - have been extensively studied in the animal kingdom. The present work provides new insights into opsin-based photoreception and photoreceptor cell evolution with a first analysis of opsin sequence data for a major deuterostome clade, the Ambulacraria. Systematic data analysis, including for the first time hemichordate opsin sequences and an expanded echinoderm dataset, led to a robust opsin phylogeny for this cornerstone superphylum. Multiple genomic and transcriptomic resources were surveyed to cover each class of Hemichordata and Echinodermata. In total, 119 ambulacrarian opsin sequences were found, 22 new sequences in hemichordates and 97 in echinoderms (including 67 new sequences). We framed the ambulacrarian opsin repertoire within eumetazoan diversity by including selected reference opsins from non-ambulacrarians. Our findings corroborate the presence of all major ancestral bilaterian opsin groups in Ambulacraria. Furthermore, we identified two opsin groups specific to echinoderms. In conclusion, a molecular phylogenetic framework for investigating light-perception and photobiological behaviors in marine deuterostomes has been obtained

High-Throughput Sequencing Characterizes Intertidal Meiofaunal Communities in Northern Gulf of Mexico (Dauphin Island and Mobile Bay, Alabama)

Abstract. Meiofauna are important components of food webs and for nutrient exchange between the benthos and water column. Recent studies have focused on these communities in the Gulf of Mexico due to potential impacts of the Deepwater Horizon Oil Spill (DWHOS). In particular, intertidal meiofaunal communities from Mobile Bay and Dauphin Island, Alabama, were previously shown to shift from predominately metazoan taxa prior to DWHOS to a fungal-dominated community after the spill. However, knowledge of variability within these communities remains unknown. Herein, we used Illumina high-throughput amplicon sequencing to examine variation throughout a year for the same locations for which the organismal shift was noted. Sediment samples were collected bi-monthly for a year (July 2011–July 2012) from which the meiofaunal community was examined by sequencing the eukaryotic hypervariable V9 region of the 18S rRNA gene. Results showed that the presence of fungal taxa was limited within these communities, suggesting that previously reported acute impacts of the DWHOS on meiofauna were apparently short term. However, these meiofaunal communities show shifts in proportions of metazoan taxa compared to pre-spill samples. Whether this change is due to prolonged impacts of the spill or variation in community composition is unclear. Taxonomic variation within and between sampled locations throughout the study was observed, suggesting potential yearly variation in communities. Continued sampling over a longer timeframe will provide a more complete understanding of seasonality and variation within these communities. Such a baseline is required to assess future anthropogenic impacts.Publishedye