2,783 research outputs found

    Deformation of ambient chemical gradients by sinking spheres

    Get PDF

    Detection of spatiotemporal variation in ranavirus distribution using eDNA

    Get PDF
    Amphibian population declines have been associated with emerging diseases including ranaviruses, which can cause mass die‐offs across entire amphibian communities. Understanding and mitigating disease spread requires knowledge of spatial and temporal patterns of pathogen distribution, but also how environmental factors influence pathogen occurrence. We applied environmental DNA (eDNA) detection tools to survey spatial and temporal distributions of ranaviruses by sampling 103 waterbodies in southeastern Ontario, Canada and assessed the role of abiotic factors as predictors of pathogen occurrence. Ten waterbodies sampled during June–August (>30 km between sites) revealed that ranavirus was marginally more prevalent (p = .055) during the latter part of the summer. Ninety‐three sites sampled at a finer scale (<10 km between sites) exhibited seasonal variability in ranavirus detection (site prevalence: 56% May; 66% July). Occupancy modeling revealed that wetland size and elevation influenced ranavirus occurrence while sampling date and water temperature influenced probability of detection. These findings indicate that biotic factors, such as host density and alternative hosts, should be investigated further as likely determinants of ranavirus prevalence across the landscape. Further, these results highlight the sensitivity of eDNA for detecting widespread presence of ranavirus and that abiotic factors may have a limited role in determining its prevalence and infectivity

    Extraction and Fractionation of Pigments from Saccharina latissima (Linnaeus, 2006) Using an Ionic Liquid plus Oil plus Water System

    Get PDF
    There is a strong industrial interest in the development of greener and more sustainable processes based on the use of renewable resources, and a biorefinery based on marine resources, such as macroalgae, stands as a major opportunity toward that end. In this work, Saccharina latissima (Linnaeus), a brown macroalga, was used as a source of pigments to develop an integrated platform that is able to promote the extraction and separation of chlorophyll and fucoxanthin in one single step. The process was studied, and its operational conditions were optimized with yields of extraction of chlorophyll and fucoxanthin of 4.93 ± 0.22 mgchl·gdry biomass–1 and 1956 ± 84 μgfuco·gdry biomass–1, respectively. These results were achieved with extraction systems composed of 84% of an aqueous solution of a tensioactive phosphonium-based ionic liquid (IL) at 350 mM + 16% of sunflower oil, during 40 min, using a solid–liquid ratio of 0.017 gdry biomass·mLsolvent–1. After the separation of both aqueous IL-rich and oil-rich phases, the IL content in both phases was investigated, the oil phase being free of IL. Envisioning the industrial potential of the process developed in this work, the recovery of the IL from the aqueous IL-rich phase of the initial system was attempted by a back-extraction using organic solvents immiscible in water, being shown that 82% of the IL can be recovered and reused in new cycles of extraction. The environmental and economic impacts of the final process proposed for the extraction and fractionation of chlorophyll and fucoxanthin were evaluated. Different scenarios were considered, but summing up the main results, the solvents’ recycling allowed better results, proving the economic and environmental viability of the overall process

    Combined In Silico, In Vivo, and In Vitro Studies Shed Insights into the Acute Inflammatory Response in Middle-Aged Mice

    Get PDF
    We combined in silico, in vivo, and in vitro studies to gain insights into age-dependent changes in acute inflammation in response to bacterial endotoxin (LPS). Time-course cytokine, chemokine, and NO2-/NO3- data from "middle-aged" (6-8 months old) C57BL/6 mice were used to re-parameterize a mechanistic mathematical model of acute inflammation originally calibrated for "young" (2-3 months old) mice. These studies suggested that macrophages from middle-aged mice are more susceptible to cell death, as well as producing higher levels of pro-inflammatory cytokines, vs. macrophages from young mice. In support of the in silico-derived hypotheses, resident peritoneal cells from endotoxemic middle-aged mice exhibited reduced viability and produced elevated levels of TNF-α, IL-6, IL-10, and KC/CXCL1 as compared to cells from young mice. Our studies demonstrate the utility of a combined in silico, in vivo, and in vitro approach to the study of acute inflammation in shock states, and suggest hypotheses with regard to the changes in the cytokine milieu that accompany aging. © 2013 Namas et al

    High energy emission from microquasars

    Full text link
    The microquasar phenomenon is associated with the production of jets by X-ray binaries and, as such, may be associated with the majority of such systems. In this chapter we briefly outline the associations, definite, probable, possible, and speculative, between such jets and X-ray, gamma-ray and particle emission.Comment: Contributing chapter to the book Cosmic Gamma-Ray Sources, K.S. Cheng and G.E. Romero (eds.), to be published by Kluwer Academic Publishers, Dordrecht, 2004. (19 pages

    Enhancement of outflow facility in the murine eye by targeting selected tight-junctions of Schlemm's canal endothelia

    Get PDF
    The juxtacanalicular connective tissue of the trabecular meshwork together with inner wall endothelium of Schlemm’s canal (SC) provide the bulk of resistance to aqueous outflow from the anterior chamber. Endothelial cells lining SC elaborate tight junctions (TJs), down-regulation of which may widen paracellular spaces between cells, allowing greater fluid outflow. We observed significant increase in paracellular permeability following siRNA-mediated suppression of TJ transcripts, claudin-11, zonula-occludens-1 (ZO-1) and tricellulin in human SC endothelial monolayers. In mice claudin-11 was not detected, but intracameral injection of siRNAs targeting ZO-1 and tricellulin increased outflow facility significantly. Structural qualitative and quantitative analysis of SC inner wall by transmission electron microscopy revealed significantly more open clefts between endothelial cells treated with targeting, as opposed to non-targeting siRNA. These data substantiate the concept that the continuity of SC endothelium is an important determinant of outflow resistance, and suggest that SC endothelial TJs represent a specific target for enhancement of aqueous movement through the conventional outflow system

    Dysthanasia: nursing professionals' perception

    Get PDF
    Dysthanasia means slow and painful death without quality of life. This study aimed to know whether nurses identify dysthanasia as part of the final process of the lives of terminal patients hospitalized at an adult ICU. This is an exploratory-qualitative study. Data were collected through semi-structured interviews with ten nurses with at least one year of experience in an ICU, and interpreted through content analysis. Results indicate that nurses understand and identify dysthanasia, do not agree with it and recognize elements of orthonasia as the adequate procedure for terminal patients. We conclude that nurses interpret dysthanasia as extending life with pain and suffering, while terminal patients are submitted to futile treatments that do not benefit them. They also identify dysthanasia using elements of orthonasia to explain it.Distanasia significa muerte lenta, con sufrimiento y sin calidad de vida. En esta investigación se buscó conocer si los enfermeros identifican la distanasia como parte del proceso final de la vida de personas en estado terminal, internadas en una UTI para adultos. El estudio es de naturaleza exploratoria, con abordaje cualitativo. Los datos fueron recolectados por medio de entrevista semiestructurada con 10 enfermeros con un mínimo de un año de experiencia en UTI; los datos fueron interpretados por el análisis de contenido. Se obtuvo como resultado que los enfermeros comprenden e identifican la distanasia y se oponen a la misma, presentando elementos de ortotanasia como procedimiento adecuado para pacientes en estado terminal. Se concluye que los enfermeros interpretan la distanasia como el prolongamiento de la vida con dolor y sufrimiento, en el cual los pacientes terminales son sometidos a tratamientos fútiles que no traen beneficios. También identifican la distanasia, usando elementos de la ortotanasia para hacerla explicita.Distanásia significa morte lenta, sofrida e sem qualidade de vida. Nesta pesquisa buscou-se conhecer se os enfermeiros identificam a distanásia como parte do processo final da vida de pessoas em terminalidade, internadas em UTI adulto. O estudo é de natureza exploratória, com abordagem qualitativa. Os dados foram coletados por meio de entrevista semiestruturada com 10 enfermeiros com, no mínimo, um ano de experiência em UTI, e interpretados pela análise de conteúdo. Teve-se como resultado que os enfermeiros compreendem e identificam a distanásia e se opõem à mesma, trazendo elementos da ortotanásia como procedimento adequado para pacientes em terminalidade. Conclui-se que os enfermeiros interpretam a distanásia como o prolongamento de vida com dor e sofrimento, onde os pacientes terminais são submetidos a tratamentos fúteis que não trazem benefícios. E também identificam a distanásia, usando elementos da ortotanásia para explicitá-la

    Information security: Listening to the perspective of organisational insiders

    Get PDF
    Aligned with the strategy-as-practice research tradition, this article investigates how organisational insiders understand and perceive their surrounding information security practices, how they interpret them, and how they turn such interpretations into strategic actions. The study takes a qualitative case study approach, and participants are employees at the Research & Development department of a multinational original brand manufacturer. The article makes an important contribution to organisational information security management. It addresses the behaviour of organisational insiders – a group whose role in the prevention, response and mitigation of information security incidents is critical. The article identifies a set of organisational insiders’ perceived components of effective information security practices (organisational mission statement; common understanding of information security; awareness of threats; knowledge of information security incidents, routines and policy; relationships between employees; circulation of stories; role of punishment provisions; and training), based on which more successful information security strategies can be developed

    PCR-based methods for the detection of L1014 kdr mutation in Anopheles culicifacies sensu lato

    Get PDF
    <p>Abstract</p> <p>Background</p> <p><it>Anopheles culicifacies s.l</it>., a major malaria vector in India, has developed widespread resistance to DDT and is becoming resistant to pyrethroids–the only insecticide class recommended for the impregnation of bed nets. Knock-down resistance due to a point mutation in the voltage gated sodium channel at L1014 residue (<it>kdr</it>) is a common mechanism of resistance to DDT and pyrethroids. The selection of this resistance may pose a serious threat to the success of the pyrethroid-impregnated bed net programme. This study reports the presence of <it>kdr </it>mutation (L1014F) in a field population of <it>An. culicifacies s.l</it>. and three new PCR-based methods for <it>kdr </it>genotyping.</p> <p>Methods</p> <p>The IIS4-IIS5 linker to IIS6 segments of the para type voltage gated sodium channel gene of DDT and pyrethroid resistant <it>An. culicifacies s.l</it>. population from the Surat district of India was sequenced. This revealed the presence of an A-to-T substitution at position 1014 leading to a leucine-phenylalanine mutation (L1014F) in a few individuals. Three molecular methods viz. Allele Specific PCR (AS-PCR), an Amplification Refractory Mutation System (ARMS) and Primer Introduced Restriction Analysis-PCR (PIRA-PCR) were developed and tested for <it>kdr </it>genotyping. The specificity of the three assays was validated following DNA sequencing of the samples genotyped.</p> <p>Results</p> <p>The genotyping of this <it>An. culicifacies s.l</it>. population by the three PCR based assays provided consistent result and were in agreement with DNA sequencing result. A low frequency of the <it>kdr </it>allele mostly in heterozygous condition was observed in the resistant population. Frequencies of the different genotypes were in Hardy-Weinberg equilibrium.</p> <p>Conclusion</p> <p>The Leu-Phe mutation, which generates the <it>kdr </it>phenotype in many insects, was detected in a pyrethroid and DDT resistant <it>An. culicifacies s.l</it>. population. Three PCR-based methods were developed for <it>kdr </it>genotyping. All the three assays were specific. The ARMS method was refractory to non-specific amplification in non-stringent amplification conditions. The PIRA-PCR assay is able to detect both the codons for the phenylalanine mutation at <it>kdr </it>locus, i.e., TTT and TTC, in a single assay, although the latter codon was not found in the population genotyped.</p

    Evaluación funcional en ancianos intervenidos de fractura de cadera

    Get PDF
    Estudio observacional prospectivo en pacientes mayores de 65 años intervenidos de fractura de cadera. El objetivo fue conocer la evolución funcional de los pacientes a los tres meses del alta hospitalaria, identificar variables relacionadas con dicha recuperación funcional, describir la mortalidad e institucionalización asociadas al proceso. Se analizaron variables demográficas como edad, sexo, convivencia. Otros aspectos registrados fueron: comorbilidad, deterioro cognitivo, capacidad para caminar, nivel de dependencia según índice de Barthel, institucionalización y mortalidad. Se recogió la información al ingreso y a los 3 meses del alta. El 89,6% de la muestra, fueron mujeres, la edad media fue de 83,56 años. El 40% de los pacientes recuperaron la independencia previa registrándose una mortalidad del 16,7% así como una leve progresión hacia la institucionalización. La capacidad funcional y el deterioro cognitivo del paciente, previos a la fractura condicionan su recuperación funcional y dependencias posteriores
    corecore