9 research outputs found

    Effect of temperature on questing activity of Ixodes scapularis in a laboratory setting

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    Understanding deer tick (Ixodes scapularis) behavior is increasingly important due to the species’ northerly range expansion, and consequently, increased human contact. Deer ticks are a major public health concern, as they are the primary vector of Lyme disease and other serious diseases. Differences in questing behavior are of considerable interest as fluctuating weather due to climate change effect the species’ range expansion and time spent questing. Although previous research has examined temperature preferences of tick behavior, there are conflicting reports about direct effects on questing activity. Therefore, I addressed the relationship between temperature and questing behavior of adult deer ticks. I predicted that most ticks exhibit questing behavior when exposed to intermediate temperatures, which are closest to average temperatures when ticks are active in Maine. My experiment exposed deer ticks to cold (10˚C), intermediate (20˚C), and warm temperatures (30˚C) in an enclosed arena with wooden rods placed into a leaf litter substrate. I observed the ticks determine the proportion that exhibit questing behavior, as well as location in the enclosure. For standardized observation, I counted the number of ticks crawling on the surface of the leaf litter, on arena walls, and on rods. The results revealed the highest questing activity occurred at the intermediate temperature. Overall, females quested more often than males. Females were much more likely to quest than males in the cold treatment. The results provide further understanding into tick questing behavior in three different temperatures

    Long-term prognosis for 1-year relapse-free survivors of CD34 cell-selected allogeneic hematopoietic stem cell transplantation : a landmark analysis

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    Altres ajuts: This research was supported in part by National Institutes of Health award number P01 CA23766 and NIH/NCI Cancer Center Support Grant P30 CA008748. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.CD34 selection significantly improves GVHD-free survival in allogeneic hematopoietic cell transplantation (allo-HSCT). Specific information regarding long-term prognosis and risk factors for late mortality after CD34-selected allo-HSCT is lacking, however. We conducted a single-center landmark analysis in 276 patients alive without relapse 1 year after CD34-selected allo-HSCT for AML (n=164), ALL (n=33), or MDS (n=79). At 5 years' follow-up after the 1-year landmark (range 0.03-13 years), estimated RFS was 73% and OS 76%. The 5-year cumulative incidence of relapse and NRM were 11% and 16%, respectively. In multivariate analysis, HCT-CI score ≥ 3 correlated with marginally worse RFS (HR 1.78, 95% CI 0.97-3.28, p=0.06) and significantly worse OS (HR 2.53, 95% CI 1.26-5.08, p=0.004). Despite only 24% of patients with acute GVHD within 1 year, this also significantly correlated with worse RFS and OS, with increasing grades of acute GVHD associating with increasingly poorer survival on multivariate analysis (p<0.0001). Of 63 deaths after the landmark, GVHD accounted for 27% of deaths and was the most common cause of late mortality, followed by relapse and infection. While prognosis is excellent for patients alive without relapse 1 year after CD34-selected allo-HSCT, risks of late relapse and NRM persist, particularly due to GVHD

    Data from: The influence of climatic variability on morphological integration, evolutionary rates, and disparity in the Carnivora

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    Biodiversity is unevenly distributed in space and time. One possible explanation is the influence of climate on the ecology, evolution, and morphology of taxa. Here we investigated the link between climatic variability and phenotypic integration, rates of morphological evolution, and disparity (morphological diversity) in three carnivoran clades (Canidae, Felidae, Mustelidae). We gathered landmark data from the lower jaw and extracted current temperature and precipitation data from range maps. We found a significant negative relationship between climatic variability and integration for canids and felids. Among canids variability in temperature was the key climatic variable, while in felids it was a combination of variability in temperature and precipitation. In both cases, relatively variable climates were associated with low phenotypic integration. We also found evidence for a negative association between climatic variability and both disparity and rates of morphological evolution in canids and mustelids. Selection can drive the evolution of jaw shape along lines of least resistance defined by patterns of integration, and this study suggests that climate may be a predictor of phenotypic integration. As a result, taxa in more variable regions (e.g., temperate, montane) may be more evolvable and more able to respond to fluctuating environmental conditions over a period of generations

    Supplementary tables S1-S10

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    Supplementary tables in Excel Workbook forma

    R Scripts, TPS files, tree, and raw data

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    Zip file contains all the raw data (in csv format), jaw landmark data (in TPS format), the tree (in Newick format), and R scripts to perform all analyses described in the main text

    Phylodynamics of deer tick virus in North America

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    The burden of ticks and the pathogens they carry is increasing worldwide. Powassan virus (POWV; Flaviviridae: ), the only known North American tick-borne flavivirus, is of particular concern due to rising cases and the severe morbidity of POWV encephalitis. Here, we use a multifaceted approach to evaluate the emergence of the II POWV lineage, known as deer tick virus (DTV), in parts of North America where human cases occur. We detected DTV-positive ticks from eight of twenty locations in the Northeast USA with an average infection rate of 1.4 per cent. High-depth, whole-genome sequencing of eighty-four POWV and DTV samples allowed us to assess geographic and temporal phylodynamics. We observed both stable infection in the Northeast USA and patterns of geographic dispersal within and between regions. A Bayesian skyline analysis demonstrated DTV population expansion over the last 50 years. This is concordant with the documented expansion of tick populations and suggests an increasing risk of human exposure as the vector spreads. Finally, we isolated sixteen novel viruses in cell culture and demonstrated limited genetic change after passage, a valuable resource for future studies investigating this emerging virus

    Long-term prognosis for 1-year relapse-free survivors of CD34 cell-selected allogeneic hematopoietic stem cell transplantation : a landmark analysis

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    Altres ajuts: This research was supported in part by National Institutes of Health award number P01 CA23766 and NIH/NCI Cancer Center Support Grant P30 CA008748. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.CD34 selection significantly improves GVHD-free survival in allogeneic hematopoietic cell transplantation (allo-HSCT). Specific information regarding long-term prognosis and risk factors for late mortality after CD34-selected allo-HSCT is lacking, however. We conducted a single-center landmark analysis in 276 patients alive without relapse 1 year after CD34-selected allo-HSCT for AML (n=164), ALL (n=33), or MDS (n=79). At 5 years' follow-up after the 1-year landmark (range 0.03-13 years), estimated RFS was 73% and OS 76%. The 5-year cumulative incidence of relapse and NRM were 11% and 16%, respectively. In multivariate analysis, HCT-CI score ≥ 3 correlated with marginally worse RFS (HR 1.78, 95% CI 0.97-3.28, p=0.06) and significantly worse OS (HR 2.53, 95% CI 1.26-5.08, p=0.004). Despite only 24% of patients with acute GVHD within 1 year, this also significantly correlated with worse RFS and OS, with increasing grades of acute GVHD associating with increasingly poorer survival on multivariate analysis (p<0.0001). Of 63 deaths after the landmark, GVHD accounted for 27% of deaths and was the most common cause of late mortality, followed by relapse and infection. While prognosis is excellent for patients alive without relapse 1 year after CD34-selected allo-HSCT, risks of late relapse and NRM persist, particularly due to GVHD
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