203 research outputs found
Fragment reattachment, reproductive status, and health indicators of the invasive colonial tunicate Didemnum vexillum with implications for dispersal
This manuscript is not subject to U.S. copyright. The definitive version was published in Biological Invasions 14 (2012): 2133-2140, doi:10.1007/s10530-012-0219-8.The invasive colonial tunicate Didemnum vexillum is now widespread in coastal and offshore waters of New England, USA. D. vexillum can inflict ecological and economic damage through biofouling and habitat modification. Natural and anthropogenic processes that fragment colonies of D. vexillum may be accelerating the spread of this invader. Reattachment success and fragment viability were confirmed in the laboratory after four weeks of suspension in experimental aquaria. The shape of suspended D. vexillum fragments progressed from flattened to globular spheres and then flattened again after reattachment to the substrate. Reproductive activity, confirmed by the presence of eggs and larvae, was observed for fragments suspended up to three weeks suggesting that D. vexillum is capable of reproducing while in a fragmented, suspended state. An index of colony health was used to monitor change in D. vexillum health while in suspension. Overall, colony health declined with time in suspension although colonies that appeared dead (black and gray in overall color) still contained a substantial number of healthy live zooids. These results suggest that activities that cause fragmentation can significantly facilitate the spread of D. vexillum. Coastal managers should consider reducing or eliminating, when practical, activities that return fragmented colonies of D. vexillum to the water. In-water cleaning of biofouling and dredging are likely expediting the spread of this invasive species unless biofouling can be contained and removed from the water.This research was funded by the NOAA Aquatic Invasive Species Program
Cost-Effectiveness Analysis of Insulin Detemir Compared to Neutral Protamine Hagedorn (NPH) in Patients with Type 1 and Type 2 Diabetes Mellitus in Spain
Introduction: An Excel® (Microsoft Corporation) model was adapted to estimate the short-term (1-year) cost effectiveness of insulin detemir (IDet) versus neutral protamine Hagedorn (NPH) insulin in patients initiating insulin treatment with type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) in Spain.
Methods: Clinical benefits included the non-severe hypoglycemia rate for T1DM and T2DM, and weight change for T2DM. Three scenarios were included with different hypoglycemia rates estimated on the basis of clinical trials and observational studies. Costs, estimated from perspective of the Spanish Public Healthcare System (Euros 2014), included insulin treatment and non-severe hypoglycemia management costs. Non-severe hypoglycemia, defined as a self-managed event, implied the use of extra glucose testing strips and a general practitioner visit during the week following the event for 25% of patients. An average disutility value was associated to non-severe hypoglycemia events and, for T2DM, to one body mass index unit gain to calculate quality-adjusted life years (QALYs).
Results: For the three scenarios a range of 0.025–0.076 QALYs for T1DM and 0.014–0.051 QALYs for T2DM were gained for IDet versus NPH due to non-severe hypoglycemia and weight gain avoidance, in return of an incremental cost of €145–192 for T1DM and €128–206 for T2DM. This resulted in the IDet versus NPH incremental cost-effectiveness ratio (ICER) ranging between €1910/QALY and €7682/QALY for T1DM and €2522/QALY and €15,009/QALY for T2DM.
Conclusion: IDet was a cost-effective alternative to NPH insulin in the first year of treatment of patients with T1DM and patients with T2DM in Spain, with ICERs under the threshold value commonly accepted in Spain (€30,000/QALY)
Sequential Effects in Judgements of Attractiveness: The Influences of Face Race and Sex
In perceptual decision-making, a person’s response on a given trial is influenced by their response on the immediately preceding trial. This sequential effect was initially demonstrated in psychophysical tasks, but has now been found in more complex, real-world judgements. The similarity of the current and previous stimuli determines the nature of the effect, with more similar items producing assimilation in judgements, while less similarity can cause a contrast effect. Previous research found assimilation in ratings of facial attractiveness, and here, we investigated whether this effect is influenced by the social categories of the faces presented. Over three experiments, participants rated the attractiveness of own- (White) and other-race (Chinese) faces of both sexes that appeared successively. Through blocking trials by race (Experiment 1), sex (Experiment 2), or both dimensions (Experiment 3), we could examine how sequential judgements were altered by the salience of different social categories in face sequences. For sequences that varied in sex alone, own-race faces showed significantly less opposite-sex assimilation (male and female faces perceived as dissimilar), while other-race faces showed equal assimilation for opposite- and same-sex sequences (male and female faces were not differentiated). For sequences that varied in race alone, categorisation by race resulted in no opposite-race assimilation for either sex of face (White and Chinese faces perceived as dissimilar). For sequences that varied in both race and sex, same-category assimilation was significantly greater than opposite-category. Our results suggest that the race of a face represents a superordinate category relative to sex. These findings demonstrate the importance of social categories when considering sequential judgements of faces, and also highlight a novel approach for investigating how multiple social dimensions interact during decision-making
A mechanism for the inhibition of DNA-PK-mediated DNA sensing by a virus
The innate immune system is critical in the response to infection by pathogens and it is activated by pattern recognition receptors (PRRs) binding to pathogen associated molecular patterns (PAMPs). During viral infection, the direct recognition of the viral nucleic acids, such as the genomes of DNA viruses, is very important for activation of innate immunity. Recently, DNA-dependent protein kinase (DNA-PK), a heterotrimeric complex consisting of the Ku70/Ku80 heterodimer and the catalytic subunit DNA-PKcs was identified as a cytoplasmic PRR for DNA that is important for the innate immune response to intracellular DNA and DNA virus infection. Here we show that vaccinia virus (VACV) has evolved to inhibit this function of DNA-PK by expression of a highly conserved protein called C16, which was known to contribute to virulence but by an unknown mechanism. Data presented show that C16 binds directly to the Ku heterodimer and thereby inhibits the innate immune response to DNA in fibroblasts, characterised by the decreased production of cytokines and chemokines. Mechanistically, C16 acts by blocking DNA-PK binding to DNA, which correlates with reduced DNA-PK-dependent DNA sensing. The C-terminal region of C16 is sufficient for binding Ku and this activity is conserved in the variola virus (VARV) orthologue of C16. In contrast, deletion of 5 amino acids in this domain is enough to knockout this function from the attenuated vaccine strain modified vaccinia virus Ankara (MVA). In vivo a VACV mutant lacking C16 induced higher levels of cytokines and chemokines early after infection compared to control viruses, confirming the role of this virulence factor in attenuating the innate immune response. Overall this study describes the inhibition of DNA-PK-dependent DNA sensing by a poxvirus protein, adding to the evidence that DNA-PK is a critical component of innate immunity to DNA viruses
Biodiversity of the Deep-Sea Continental Margin Bordering the Gulf of Maine (NW Atlantic): Relationships among Sub-Regions and to Shelf Systems
Background: In contrast to the well-studied continental shelf region of the Gulf of Maine, fundamental questions regarding
the diversity, distribution, and abundance of species living in deep-sea habitats along the adjacent continental margin
remain unanswered. Lack of such knowledge precludes a greater understanding of the Gulf of Maine ecosystem and limits
development of alternatives for conservation and management.
Methodology/Principal Findings: We use data from the published literature, unpublished studies, museum records and
online sources, to: (1) assess the current state of knowledge of species diversity in the deep-sea habitats adjacent to the Gulf
of Maine (39–43uN, 63–71uW, 150–3000 m depth); (2) compare patterns of taxonomic diversity and distribution of
megafaunal and macrofaunal species among six distinct sub-regions and to the continental shelf; and (3) estimate the
amount of unknown diversity in the region. Known diversity for the deep-sea region is 1,671 species; most are narrowly
distributed and known to occur within only one sub-region. The number of species varies by sub-region and is directly
related to sampling effort occurring within each. Fishes, corals, decapod crustaceans, molluscs, and echinoderms are
relatively well known, while most other taxonomic groups are poorly known. Taxonomic diversity decreases with increasing
distance from the continental shelf and with changes in benthic topography. Low similarity in faunal composition suggests
the deep-sea region harbours faunal communities distinct from those of the continental shelf. Non-parametric estimators of
species richness suggest a minimum of 50% of the deep-sea species inventory remains to be discovered.
Conclusions/Significance: The current state of knowledge of biodiversity in this deep-sea region is rudimentary. Our ability
to answer questions is hampered by a lack of sufficient data for many taxonomic groups, which is constrained by sampling
biases, life-history characteristics of target species, and the lack of trained taxonomists
A critical assessment of the WHO responsiveness tool: lessons from voluntary HIV testing and counselling services in Kenya
<p>Abstract</p> <p>Background</p> <p>Health, fair financing and responsiveness to the user's needs and expectations are seen as the essential objectives of health systems. Efforts have been made to conceptualise and measure responsiveness as a basis for evaluating the non-health aspects of health systems performance. This study assesses the applicability of the responsiveness tool developed by WHO when applied in the context of voluntary HIV counselling and testing services (VCT) at a district level in Kenya.</p> <p>Methods</p> <p>A mixed method study was conducted employing a combination of quantitative and qualitative research methods concurrently. The questionnaire proposed by WHO was administered to 328 VCT users and 36 VCT counsellors (health providers). In addition to the questionnaire, qualitative interviews were carried out among a total of 300 participants. Observational field notes were also written.</p> <p>Results</p> <p>A majority of the health providers and users indicated that the responsiveness elements were very important, e.g. confidentiality and autonomy were regarded by most users and health providers as very important and were also reported as being highly observed in the VCT room. However, the qualitative findings revealed other important aspects related to confidentiality, autonomy and other responsiveness elements that were not captured by the WHO tool. Striking examples were inappropriate location of the VCT centre, limited information provided, language problems, and concern about the quality of counselling.</p> <p>Conclusion</p> <p>The results indicate that the WHO developed responsiveness elements are relevant and important in measuring the performance of voluntary HIV counselling and testing. However, the tool needs substantial revision in order to capture other important dimensions or perspectives. The findings also confirm the importance of careful assessment and recognition of locally specific aspects when conducting comparative studies on responsiveness of HIV testing services.</p
Metagenomics reveals sediment microbial community response to Deepwater Horizon oil spill
The Deepwater Horizon (DWH) oil spill in the spring of 2010 resulted in an input of ∼4.1 million barrels of oil to the Gulf of Mexico; >22% of this oil is unaccounted for, with unknown environmental consequences. Here we investigated the impact of oil deposition on microbial communities in surface sediments collected at 64 sites by targeted sequencing of 16S rRNA genes, shotgun metagenomic sequencing of 14 of these samples and mineralization experiments using (14)C-labeled model substrates. The 16S rRNA gene data indicated that the most heavily oil-impacted sediments were enriched in an uncultured Gammaproteobacterium and a Colwellia species, both of which were highly similar to sequences in the DWH deep-sea hydrocarbon plume. The primary drivers in structuring the microbial community were nitrogen and hydrocarbons. Annotation of unassembled metagenomic data revealed the most abundant hydrocarbon degradation pathway encoded genes involved in degrading aliphatic and simple aromatics via butane monooxygenase. The activity of key hydrocarbon degradation pathways by sediment microbes was confirmed by determining the mineralization of (14)C-labeled model substrates in the following order: propylene glycol, dodecane, toluene and phenanthrene. Further, analysis of metagenomic sequence data revealed an increase in abundance of genes involved in denitrification pathways in samples that exceeded the Environmental Protection Agency (EPA)'s benchmarks for polycyclic aromatic hydrocarbons (PAHs) compared with those that did not. Importantly, these data demonstrate that the indigenous sediment microbiota contributed an important ecosystem service for remediation of oil in the Gulf. However, PAHs were more recalcitrant to degradation, and their persistence could have deleterious impacts on the sediment ecosystem
Solar Radiation and Tidal Exposure as Environmental Drivers of Enhalus acoroides Dominated Seagrass Meadows
There is strong evidence of a global long-term decline in seagrass meadows that is widely attributed to anthropogenic activity. Yet in many regions, attributing these changes to actual activities is difficult, as there exists limited understanding of the natural processes that can influence these valuable ecosystem service providers. Being able to separate natural from anthropogenic causes of seagrass change is important for developing strategies that effectively mitigate and manage anthropogenic impacts on seagrass, and promote coastal ecosystems resilient to future environmental change. The present study investigated the influence of environmental and climate related factors on seagrass biomass in a large ≈250 ha meadow in tropical north east Australia. Annual monitoring of the intertidal Enhalus acoroides (L.f.) Royle seagrass meadow over eleven years revealed a declining trend in above-ground biomass (54% significant overall reduction from 2000 to 2010). Partial Least Squares Regression found this reduction to be significantly and negatively correlated with tidal exposure, and significantly and negatively correlated with the amount of solar radiation. This study documents how natural long-term tidal variability can influence long-term seagrass dynamics. Exposure to desiccation, high UV, and daytime temperature regimes are discussed as the likely mechanisms for the action of these factors in causing this decline. The results emphasise the importance of understanding and assessing natural environmentally-driven change when interpreting the results of seagrass monitoring programs
Ongoing expansion of the worldwide invader Didemnum vexillum (Ascidiacea) in the Mediterranean Sea: high plasticity of its biological cycle promotes establishment in warm waters
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