2,261 research outputs found

    Formal development and verification of a distributed railway control system

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    Mouse Emi2 is required to enter meiosis II by reestablishing cyclin B1 during interkinesis

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    During interkinesis, a metaphase II (MetII) spindle is built immediately after the completion of meiosis I. Oocytes then remain MetII arrested until fertilization. In mouse, we find that early mitotic inhibitor 2 (Emi2), which is an anaphase-promoting complex inhibitor, is involved in both the establishment and the maintenance of MetII arrest. In MetII oocytes, Emi2 needs to be degraded for oocytes to exit meiosis, and such degradation, as visualized by fluorescent protein tagging, occurred tens of minutes ahead of cyclin B1

    Invasibility of three major non-native invasive shrubs and associated factors in Upper Midwest U.S. forest lands

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    We used non-native invasive plant data from the US Forest Service’s Forest Inventory and Analysis (FIA) program, spatial statistical methods, and the space (cover class)-for-time approach to quantify the invasion potential and success (‘‘invasibility”) of three major invasive shrubs (multiflora rose, non-native bush honeysuckles, and common buckthorn) in broadly classified forest-type groups in seven Upper Midwest states. Smoothed maps of presence and cover percent showed a strong clustering pattern for all three invasive shrubs despite their different ranges. The species are clustered around major cities or urban areas (e.g., Chicago, Illinois, and Des Moines, Iowa), indicating the potential role humans played in their invasion and spread on the landscape and throughout the Midwest. Conditional inference tree (ctree) models further quantified the significant factors contributing to the observed regional patterns: for distribution of multiflora rose, percentage of forest cover in the county (measuring human disturbance intensity) and stand density index; for distribution of common buckthorn, distance to major highways. Non-native bush honeysuckles were not associated with any disturbance and site/stand variables except for latitude and longitude. The infested FIA plots by cover class were positively associated in space, signifying a concentric-like spread trend from previously infested sites (hot spots) to surrounding areas. By forest-type groups or as a whole, the three species spread slowly at earlier stages, but recently have increased significantly in presence/ expansion. Oak/hickory and elm/ash/cottonwood forests were more susceptible to the three invasive shrubs compared to other forests. We recommend that resource managers and planners prescribe control and mitigation treatments for non-native invasive plants by forest types and spatial locations close to highways and residences

    Maternal demographic and clinical variables do not predict intrauterine contraception placement: Evidence for postplacental intrauterine contraception placement

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    Objective: Determine if specific demographic and clinical variables are associated with intra-uterine contraception (IUC) placement by eight weeks postpartum. Methods: This retrospective cohort study included all patients who delivered at Dartmouth-Hitchcock Medical Center (DHMC) (July-December 2008) who identified IUC as their preferred postpartum contraceptive method. Medical records of patients identified from the birth log were reviewed for preferred contraception, demographics, medical, obstetric, and social histories, as well as payer status. Chi-squared analysis was performed for categorical variables, and Mann-Whitney U test was used for continuous variables. Nonparametric continuous variables were categorized for regression modeling. Results: 224 (34%) patients who delivered identified IUC as their preferred method of postpartum contraception. Of these, 94 (49.7%) women had an IUC placed by 8 weeks postpartum. In univariate analyses comparing those who received an IUC versus those patients who did not, only mean interdelivery interval in months (39.7 vs. 35.5, p=0.027) and mean gravidity (2.3 vs. 2.8, p=0.036) were statistically significant. In multivariate regression modeling, no variables were significantly associated with IUC placement. Conclusions: While statically significant interdelivery interval and gravidity are not likely to be clinically significant. Multivariate modeling failed to identify a model associated with IUC placement suggesting that postpartum IUC placement is not well predicted by patient variables. Lack of identifying factors may support offering postplacental IUC placement to all patients who indicate IUC as their preferred contraceptive method

    Invasibility of three major non-native invasive shrubs and associated factors in Upper Midwest U.S. forest lands

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    We used non-native invasive plant data from the US Forest Service’s Forest Inventory and Analysis (FIA) program, spatial statistical methods, and the space (cover class)-for-time approach to quantify the invasion potential and success (‘‘invasibility”) of three major invasive shrubs (multiflora rose, non-native bush honeysuckles, and common buckthorn) in broadly classified forest-type groups in seven Upper Midwest states. Smoothed maps of presence and cover percent showed a strong clustering pattern for all three invasive shrubs despite their different ranges. The species are clustered around major cities or urban areas (e.g., Chicago, Illinois, and Des Moines, Iowa), indicating the potential role humans played in their invasion and spread on the landscape and throughout the Midwest. Conditional inference tree (ctree) models further quantified the significant factors contributing to the observed regional patterns: for distribution of multiflora rose, percentage of forest cover in the county (measuring human disturbance intensity) and stand density index; for distribution of common buckthorn, distance to major highways. Non-native bush honeysuckles were not associated with any disturbance and site/stand variables except for latitude and longitude. The infested FIA plots by cover class were positively associated in space, signifying a concentric-like spread trend from previously infested sites (hot spots) to surrounding areas. By forest-type groups or as a whole, the three species spread slowly at earlier stages, but recently have increased significantly in presence/ expansion. Oak/hickory and elm/ash/cottonwood forests were more susceptible to the three invasive shrubs compared to other forests. We recommend that resource managers and planners prescribe control and mitigation treatments for non-native invasive plants by forest types and spatial locations close to highways and residences

    Planet Four: A Neural Network’s search for polar spring-time fans on Mars

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    Dark deposits visible from orbit appear in the Martian south polar region during the springtime. These are thought to form from explosive jets of carbon dioxide gas breaking through the thawing seasonal ice cap, carrying dust and dirt which is then deposited onto the ice as dark ‘blotches’, or blown by the surface winds into streaks or ‘fans’. We investigate machine learning (ML) methods for automatically identifying these seasonal features in High Resolution Imaging Science Experiment (HiRISE) satellite imagery. We designed deep Convolutional Neural Networks (CNNs) that were trained and tested using the catalog generated by Planet Four, an online citizen science project mapping the south polar seasonal deposits. We validated the CNNs by comparing their results with those of ISODATA (Iterative Self-Organizing Data Analysis Technique) clustering and as expected, the CNNs were significantly better at predicting the results found by Planet Four, in both the area of predicted seasonal deposits and in delineating their boundaries. We found neither the CNNs or ISODATA were suited to predicting the source point and directions of seasonal fans, which is a strength of the citizen science approach. The CNNs showed good agreement with Planet Four in cross-validation metrics and detected some seasonal deposits in the HiRISE images missed in the Planet Four catalog; the total area of seasonal deposits predicted by the CNNs was 27% larger than that of the Planet Four catalog, but this aspect varied considerably on a per-image basis

    The Outbursts and Orbit of the Accreting Pulsar GS 1843-02 = 2S 1845-024

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    We present observations of a series of 10 outbursts of pulsed hard X-ray flux from the transient 10.6 mHz accreting pulsar GS 1843-02, using the Burst and Transient Source Experiment on the Compton Gamma Ray Observatory. These outbursts occurred regularly every 242 days, coincident with the ephemeris of the periodic transient GRO J1849-03 (Zhang et al. 1996), which has recently been identified with the SAS 3 source 2S 1845-024 (Soffitta et al. 1998). Our pulsed detection provides the first clear identification of GS 1843-02 with 2S 1845-024. We present a pulse timing analysis which shows that the 2S 1845-024 outbursts occur near the periastron passage of the neutron star's highly eccentric (e = 0.88+-0.01) 242.18+-0.01 day period binary orbit about a high mass (M > 7 solar masses) companion. The orbit and transient outburst pattern strongly suggest the pulsar is in a binary system with a Be star. Our observations show a long-term spin-up trend, with most of the spin-up occurring during the outbursts. From the measured spin-up rates and inferred luminosities we conclude that an accretion disk is present during the outbursts.Comment: Accepted for publication in Astrophysical Journa

    Gastric cancer and Helicobacter pylori: a combined analysis of 12 case control studies nested within prospective cohorts

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    BACKGROUND: The magnitude of the association between Helicobacter pylori and incidence of gastric cancer is unclear. H pylori infection and the circulating antibody response can be lost with development of cancer; thus retrospective studies are subject to bias resulting from classifi- cation of cases as H pylori negative when they were infected in the past. AIMS: To combine data from all case control studies nested within prospective cohorts to assess more reliably the relative risk of gastric cancer associated with H pylori infection.To investigate variation in relative risk by age, sex, cancer type and subsite, and interval between blood sampling and cancer diagnosis. METHODS: Studies were eligible if blood samples for H pylori serology were collected before diagnosis of gastric cancer in cases. Identified published studies and two unpublished studies were included. Individual subject data were obtained for each. Matched odds ratios (ORs) and 95% confidence intervals (95% CI) were calculated for the association between H pylori and gastric cancer. RESULTS: Twelve studies with 1228 gastric cancer cases were considered. The association with H pylori was restricted to noncardia cancers (OR 3.0; 95% CI 2.3–3.8) and was stronger when blood samples for H pylori serology were collected 10+ years before cancer diagnosis (5.9; 3.4–10.3). H pylori infection was not associated with an altered overall risk of cardia cancer (1.0; 0.7–1.4). CONCLUSIONS: These results suggest that 5.9 is the best estimate of the relative risk of non-cardia cancer associated with H pylori infection and that H pylori does not increase the risk of cardia cancer. They also support the idea that when H pylori status is assessed close to cancer diagnosis, the magnitude of the non-cardia association may be underestimated

    Process mapping strategies to prevent subcutaneous implantable cardioverter-defibrillator infections

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    Background: Infection remains a major complication of cardiac implantable electronic devices and can lead to significant morbidity and mortality. Implantable devices that avoid transvenous leads, such as the subcutaneous implantable cardioverter-defibrillator (S-ICD), can reduce the risk of serious infection-related complications, such as bloodstream infection and infective endocarditis. While the 2017 AHA/ACC/HRS guidelines include recommendations for S-ICD use for patients at high risk of infection, currently, there are no clinical trial data that address best practices for the prevention of S-ICD infections. Therefore, an expert panel was convened to develop a consensus on these topics. Methods: An expert process mapping methodology was used to achieve consensus on the appropriate steps to minimize or prevent S-ICD infections. Two face-to-face meetings of high-volume S-ICD implanters and an infectious diseases specialist, with expertise in cardiovascular implantable electronic device infections, were conducted to develop consensus on useful strategies pre-, peri-, and postimplant to reduce S-ICD infection risk. Results: Expert panel consensus on recommended steps for patient preparation, S-ICD implantation, and postoperative management was developed to provide guidance in individual patient management. Conclusion: Achieving expert panel consensus by process mapping methodology for S-ICD infection prevention was attainable, and the results should be helpful to clinicians in adopting interventions to minimize risks of S-ICD infection

    Impact of an icy winter on the Pacific oyster (Crassostrea gigas Thunberg, 1793) populations in Scandinavia

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    The Pacific oyster (Crassostrea gigas) is an invasive species that has dispersed into Scandinavia during the last few decades. The objective of this study was to evaluate the effects of extreme winter conditions on the mortality of the Pacific oyster in Scandinavia. The study was done by compiling mortality data from independent surveys in Denmark, Sweden and Norway. Winter mortality of the oysters increased with latitude, which can be explained by the colder climate experienced at higher latitudes. Mortality was also found to be affected by site specific conditions such as water depth at the sampling sites of oyster populations. Despite the severe winter conditions of 2009/2010 causing high mortality, the Pacific oyster still exists in large numbers in Scandinavia. The present investigation indicates that extreme winter onditions may result in a temporary reduction of the density of the Pacific oyster, but that the species can be expected to continue its invasion of Scandinavian coastal areas.publishedVersio
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