4,629 research outputs found

    Enhanced immunogenicity of Renibacterium salmoninarum in chinook salmon after removal of the bacterial cell surface-associated 57 kDa protein

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    A study was conducted to determine the effect of endogenous serine protease activity on the immunogenicity of Renibacterium salmoninarum cells in chinook salmon Oncorhynchus tshawytscha. Salmon were immunized with either R. salmoninarum cells possessing p57 (p57(+)) or substantially depleted of p57 (p57(-)). The resultant antisera were examined by whole cell ELISA and immunoblot procedures using p57(+), p57(-), proteinase-K-treated, and periodate-treated whole cells. These analyses revealed that the removal of p57 by the endogenous serine protease significantly enhanced the immunogenicity of the cell, resulting in a 20-fold increase in detectable antibody titers. The bulk of this antibody activity was directed at sites blocked by the presence of the p57 molecule. Furthermore, proteinase-K and periodate treatment of R. salmoninarum cells revealed that the increased antibody activity almost exclusively reacted with carbohydrate moieties on the p57(-) cell

    Luminosities of AGB Variables

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    The prevailing evidence suggests that most large-amplitude AGB variables follow the period luminosity (PL) relation that has been established for Miras in the LMC and galactic globular clusters. Hipparcos observations indicate that most Miras in the solar neighbourhood are consistent with such a relation. There are two groups of stars with luminosities that are apparently greater than the PL relation would predict: (1) in the LMC and SMC there are large amplitude variables, with long periods, P> 420 days, which are probably undergoing hot bottom burning, but which are very clearly more luminous than the PL relation (these are visually bright and are likely to be among the first stars discovered in more distant intermediate age populations); (2) in the solar neighbourhood there are short period, P<235 days, red stars which are probably more luminous than the PL relation. Similar short-period red stars, with high luminosities, have not been identified in the Magellanic Clouds.Comment: 8 pages, 2 figure, to be published in Mass-Losing Pulsating Stars and their Circumstellar Matter, Y. Nakada & M. Honma (eds) Kluwer ASSL serie

    Stormflow hydrochemistry in a river draining an abandoned metal mine: the Afon Twymyn, central Wales

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    Contaminated drainage from metal mines is a serious water-quality problem facing nations that exploit metal mineral resources. Measurements of river hydrochemistry during baseflow are common at mine sites, whilst detailed hydrochemical information regarding stormflow is limited and often confined to a single event. This study investigates the seasonal evolution of stormflow hydrochemistry at an abandoned metal mine in central Wales, UK, and the possible sources and mechanisms of metal release. Significant flushing of metals was observed during stormflow events, resulting in concentrations that severely exceeded water-quality guidelines. The relationship between metal concentrations and river discharge suggests dissolution of efflorescent metal sulphates on the surface of the mine spoil as the principal source of the contamination. High fluxes of Pb during stormflows are linked to extended periods of dry weather prior to storm events that produced water table drawdown and encouraged oxidation of Pb sulphide in the mine spoil. However, some Pb flushing also occurred following wet antecedent conditions. It is suggested that Fe oxide reduction in mine spoil and translatory flows involving metal-rich pore waters results in flushing during wetter periods. Detailed measurements of stormflow hydrochemistry at mine sites are essential for accurate forecasting of long-term trends in metals flux to understand metal sources and mechanisms of release, to assess potential risks to water quality and instream ecology, and to gauge the potential effectiveness of remediation. In order to protect riverine and riparian ecosystems, it is suggested that routine monitoring of stormflows becomes part of catchment management in mining-impacted regions

    Short-term fluctuations in heavy metal concentrations during flood events through abandoned metal mines, with implications for aquatic ecology and mine water treatment

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    The variability in heavy metal concentrations and physico-chemical parameters during rain-fed river floods that pass through abandoned metal mines is poorly understood due to the difficulties of sampling these events. Such information is essential for the characterisation of contaminant dynamics and for investigations of contaminant/ecosystem relations and the effectiveness of remediation. This study investigates the role of flood flows in contaminant mobilisation and temporary increases in toxicity at an abandoned metal mine in central Wales, UK. Flood events substantially increase the potential toxicity of river water. The principal contaminants are dissolved Pb, mobilized by increased acidity resulting from the dissolution and flushing of efflourescent salts accumulated on the surface of mine spoil. The implications of flood runoff and contaminant mobilisation for aquatic ecology and mine water treatment are discussed

    HDX and In Silico Docking Reveal that Excipients Stabilize G-CSF via a Combination of Preferential Exclusion and Specific Hotspot Interactions

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    Assuring the stability of therapeutic proteins is a major challenge in the biopharmaceutical industry, and a better molecular understanding of the mechanisms through which formulations influence their stability is an ongoing priority. While the preferential exclusion effects of excipients are well known, the additional presence and impact of specific protein–excipient interactions have proven to be more elusive to identify and characterize. We have taken a combined approach of in silico molecular docking and hydrogen deuterium exchange-mass spectrometry (HDX-MS) to characterize the interactions between granulocyte colony-stimulating factor (G-CSF), and some common excipients. These interactions were related to their influence on the thermal-melting temperatures (Tm) for the nonreversible unfolding of G-CSF in liquid formulations. The residue-level interaction sites predicted in silico correlated well with those identified experimentally and highlighted the potential impact of specific excipient interactions on the Tm of G-CSF

    Parameter estimations of sigmoidal models of cancer

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    Phylogeny, biogeography and diversification patterns of side-necked turtles (Testudines: Pleurodira)

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    Pleurodires or side-necked turtles are today restricted to freshwater environments of South America, Africa– Madagascar and Australia, but in the past they were distributed much more broadly, being found also on Eurasia, India and North America, and marine environments. Two hypotheses were proposed to explain this distribution; in the first, vicariance would have shaped the current geographical distribution and, in the second, extinctions constrained a previously widespread distribution. Here, we aim to reconstruct pleurodiran biogeographic history and diversification patterns based on a new phylogenetic hypothesis recovered from the analysis of the largest morphological dataset yet compiled for the lineage, testing which biogeographical process prevailed during its evolutionary history. The resulting topology generally agrees with previous hypotheses of the group and shows that most diversification shifts were related to the exploration of new niches, e.g. littoral or marine radiations. In addition, as other turtles, pleurodires do not seem to have been much affected by either the Cretaceous– Palaeogene or the Eocene–Oligocene mass extinctions. The biogeographic analyses highlight the predominance of both anagenetic and cladogenetic dispersal events and support the importance of transoceanic dispersals as a more common driver of area changes than previously thought, agreeing with previous studies with other non-turtle lineages.Fil: Ferreira, Gabriel S.. Universidade de Sao Paulo; Brasil. Senckenberg Centre For Human Evolution And Palaeoenvironment; Alemania. Universität Tübingen; AlemaniaFil: Bronzati Filho, Mario. Bayerische Staatssammlung für Paläontologie und Geologie; AlemaniaFil: Langer, Max C.. Universidade de Sao Paulo; BrasilFil: Sterli, Juliana. Museo Paleontológico Egidio Feruglio; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Disease-associated gut microbiome and metabolome changes in patients with chronic obstructive pulmonary disease.

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    Chronic obstructive pulmonary disease (COPD) is the third commonest cause of death globally, and manifests as a progressive inflammatory lung disease with no curative treatment. The lung microbiome contributes to COPD progression, but the function of the gut microbiome remains unclear. Here we examine the faecal microbiome and metabolome of COPD patients and healthy controls, finding 146 bacterial species differing between the two groups. Several species, including Streptococcus sp000187445, Streptococcus vestibularis and multiple members of the family Lachnospiraceae, also correlate with reduced lung function. Untargeted metabolomics identifies a COPD signature comprising 46% lipid, 20% xenobiotic and 20% amino acid related metabolites. Furthermore, we describe a disease-associated network connecting Streptococcus parasanguinis_B with COPD-associated metabolites, including N-acetylglutamate and its analogue N-carbamoylglutamate. While correlative, our results suggest that the faecal microbiome and metabolome of COPD patients are distinct from those of healthy individuals, and may thus aid in the search for biomarkers for COPD

    Malpais spring virus is a new species in the genus vesiculovirus

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    BACKGROUND: Malpais Spring virus (MSPV) is a mosquito-borne rhabdovirus that infects a variety of wild and feral ungulates in New Mexico, including horses and deer. Although, initial serologic tests and electron microscopy at the time of isolation nearly 25 years ago provided evidence that MSPV is a novel virus, possibly related to vesiculoviruses, the virus still has not been approved as a new species. FINDINGS: Use of the illumina platform allowed us to obtain the complete genome of MSPV. Analysis of the complete 11019 nt genome sequence of the prototype 85-488NM strain of MSPV indicates that it encodes the five common rhabdovirus structural proteins (N, P, M, G and L) with alternative ORFs (> 180 nt) in the N, M and G genes, including a 249 nt ORF in the G gene predicted to encode a 9.26 kDa highly basic transmembrane protein. Although antigenically very distant, phylogenetic analysis of the L gene indicates that MSPV is most closely related to Jurona virus, also isolated from mosquitoes in Brazil, as well as a number of other vesiculoviruses. CONCLUSIONS: In sum, our analysis indicates MSPV should be classified as a member of the genus Vesiculovirus, family Rhabdoviridae. The complete genome sequence of MSPV will be helpful in the development of a reverse genetics system to study the unique aspects of this vesiculovirus in vivo and in vitro, and will assist development of specific diagnostic tests to study the epidemiology of MSPV infection
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