893 research outputs found

    Analysis of Fluorinated Polyimides Flown on the Materials International Space Station Experiment

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    This Technical Memorandum documents the results from the Materials on International Space Station Experiment (MISSE) series involving fluorinated polyimide films analyzed at NASA Marshall Space Flight Center. These films may be used in thermal control, sunshield, solar sail, solar concentrator, and other lightweight polymer film applications. Results include postflight structural integrity, visual observations, determination of atomic oxygen erosion yield, and optical property changes as compared to preflight values

    Multiple Captures of White-footed Mice (Peromyscus leucopus): Evidence for Social Structure?

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    Multiple captures (34 double, 6 triple) in standard Sherman live traps accounted for 6.3% of 1355 captures of Peromyscus leucopus (white-footed mice) in forested habitat in southern Illinois, from Oct. 2004 through Oct. 2005. There was a significant positive relationship between both the number and the proportion of multiple captures and estimated monthly population size. Multiple captures were all intraspecific and occurred significantly more often from Nov. through Mar. when animals were not reproductively active, but this was confounded by seasonal changes in abundance. Age/gender distribution of animals in double captures did not differ from that expected from random pairing. We suggest that sociality and synchronous entry of two white-footed mice into traps were the primary determinants of double captures; sensitivity of traps may have been the primary factor in triple capture

    Safety and Preliminary Immunogenicity of Recombinant Hepatitis B (Bio Farma) Vaccine in Adults and Children: A Phase 1 Clinical Trial

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    Background: In order to fulfil the requirements of the national immunization program and sustain the production capacity of the monovalent Hepatitis B vaccine, this study aimed to assess the safety and immunogenicity of the recombinant Hepatitis B Vaccine (Bio Farma) using the new Hepatitis B bulk. Methods: This study was an experimental, randomized, double-blinded, and controlled Phase I clinical trial, with 100 healthy subjects divided into 50 adults and 50 adolescents. Subjects were randomly assigned to receive either the Bio Farma registered Recombinant Hepatitis B Vaccine (group A) or a new source of Hepatitis B bulk (group B). Subjects received one or three doses of vaccine, depending on the baseline anti-Hbs titer. Subjects were given diary cards to record solicited and unsolicited adverse events for 28 days following vaccination. Vaccine immunogenicity was assessed by measuring the level of HBsAg antibody titer elevation.Results: No serious adverse events were reported during clinical trials. The frequencies of adverse events were not significantly different between the two vaccine-randomized groups. The most immediately observed local reaction was local pain, reported by 35.7–42.8% of adults and 24.0–26.3% of adolescents, without any systemic reactions. Seroconversion in adults in group B reached 100% and 78.5% in group A, meanwhile in adolescent subjects in both groups it reached 100%. A substantial increase in geometric mean titer (GMT) was observed in the majority of subjects after immunization.Conclusion: Recombinant Hepatitis B Vaccine with a new source of HBsAg B bulk is safe, well tolerated, and highly immunogenic

    Effects of bark beetle outbreaks on forest landscape pattern in the southern rocky mountains, U.S.A.

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    Since the late 1990s, extensive outbreaks of native bark beetles (Curculionidae: Scolytinae) have affected coniferous forests throughout Europe and North America, driving changes in carbon storage, wildlife habitat, nutrient cycling, and water resource provisioning. Remote sensing is a cru-cial tool for quantifying the effects of these disturbances across broad landscapes. In particular, Landsat time series (LTS) are increasingly used to characterize outbreak dynamics, including the presence and severity of bark beetle-caused tree mortality, though broad-scale LTS-based maps are rarely informed by detailed field validation. Here we used spatial and temporal information from LTS products, in combination with extensive field data and Random Forest (RF) models, to develop 30-m maps of the presence (i.e., any occurrence) and severity (i.e., cumulative percent basal area mortality) of beetle-caused tree mortality 1997–2019 in subalpine forests throughout the Southern Rocky Mountains, USA. Using resultant maps, we also quantified spatial patterns of cumulative tree mortality throughout the region, an important yet poorly understood concept in beetle-affected forests. RF models using LTS products to predict presence and severity performed well, with 80.3% correctly classified (Kappa = 0.61) and R2 = 0.68 (RMSE = 17.3), respectively. We found that ≥10,256 km2 of subalpine forest area (39.5% of the study area) was affected by bark beetles and 19.3% of the study area experienced ≥70% tree mortality over the twenty-three year period. Variograms indi-cated that severity was autocorrelated at scales \u3c 250 km. Interestingly, cumulative patch-size dis-tributions showed that areas with a near-total loss of the overstory canopy (i.e., ≥90% mortality) were relatively small (\u3c0.24 km2) and isolated throughout the study area. Our findings help to in-form an understanding of the variable effects of bark beetle outbreaks across complex forested regions and provide insight into patterns of disturbance legacies, landscape connectivity, and susceptibility to future disturbance
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