Survival and activity patterns of snowshoe hares (Lepus americanus) in interior Alaska

Thesis (M.S.) University of Alaska Fairbanks, 2013Snowshoe hare (Lepus americanus) survival depends on the interaction of habitat characteristics with numerous biological and environmental variables. In boreal regions where considerable habitat heterogeneity exists, hares balance food availability with predation risk by moving among habitats seasonally, but it is largely unknown how often they move at shorter time scales. I investigated the seasonal effects of habitat, weather, and individual hare characteristics on survival and movement in two common but fundamentally different boreal habitats. Survival was highest in summer, for hares with higher body condition, and in black spruce rather than early successional forest. Hares moved among core use areas in different habitats twice per day on average, using more open areas at night when they were presumably feeding on preferred browse. Movement rates were lowest in mid-afternoon when hares appeared to be resting under dense cover. Behavior of individuals varied greatly with some hares repeatedly moving up to 1 km between defined patches in less than 5 hours and others remaining roughly within a 1 ha area. These findings illustrate the complexity of snowshoe hare ecology in an area where habitat variation promotes daily movement of hares among radically different habitats over a few hundred meters.Chapter 1. Spatial and temporal patterns of survival for snowshoe hares (Lepus americanus) in interior Alaska -- Chapter 2: Movement, activity patterns, and habitat use of snowshoe hares (Lepus americanus) in interior Alaska -- General conclusions

Cable-stayed glass façades - 15 years of innovation at the cutting edge

Today’s demand for highly transparent building envelopes calls for innovativesolutions. Cable-stayed glass façades make it possible to dematerialize the buildingenvelope so as to make it almost imperceptible. Werner Sobek has designed a greatnumber and variety of cable-stayed façades. The primary structural system carryingmost of these façades consists of straight tension members (e.g. tension rods,cables), typically in a parallel arrangement. The tension members transfer the deadload of the glazing very efficiently to the supports. Under wind load the membersundergo large deflections thus activating their lateral stiffness. As a result, thedetailing of these façades requires innovative design approaches and special care toallow for such large deflections. Besides this, each project has its individualchallenges such as a complex geometry, large openings, difficult edge conditions,warping of IG units, bomb blast requirements, etc. The present article gives anoverview of the development of cable-stayed façades as designed by Werner Sobekover the last 15 years. The overview includes completed projects as well as façadescurrently under construction or in the design phase

First sequence-confirmed case of infection with the new influenza A(H1N1) strain in Germany

Here, we report on the first sequence-confirmed case of infection with the new influenza A(H1N1) virus in Germany. Two direct contacts of the patient were laboratory-confirmed as cases and demonstrate a chain of direct human-to-human transmission

An inconvenient truth? Interpersonal and career consequences of “maybe baby” expectations

This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.We examine a counterintuitive effect of motherhood and parental leave policies: supervisors and coworkers may view early career women who have yet to have children (i.e., childless women) with greater uncertainty and inconvenience than their counterparts (i.e., childless men), especially in organizations offering more maternal than paternal leave. We propose that these “maybe baby” expectations manifest as workplace incivility, which predicts later career withdrawal. In a time-lagged survey study, we examined 474 early career employees' experiences of workplace incivility and career withdrawal cognitions one year later; we also collected objective data on organizations' maternal and paternal leave policies. As expected, childless women experienced more incivility than their counterparts, a difference that was greater in organizations with larger differences between maternal leave and paternal leave policies and positively associated with subsequent career withdrawal. Discussion focuses on the importance of examining individual- and organizational-level work-family antecedents for understanding modern workplace mistreatment and its career effects in context, as well as the effective design and implementation of work-family policies

Comparison of four different treatment strategies in teeth with molar-incisor hypomineralization-related enamel breakdown–A retrospective cohort study

Background There is little information available on the longevity of non-invasive glass ionomer cement (GIC) and composite restorations as well as conventional composite and ceramic restorations placed on permanent teeth with enamel breakdowns due to molar-incisor hypomineralization (MIH). Aim To compare the longevity of the abovementioned treatment procedures. Design Of 377 identified MIH patients, 118 individuals received restorative treatment and were invited for clinical examination, including caries and MIH status. Finally, survival data from 204 MIH-related restorations placed on 127 teeth were retrospectively collected from 52 children, monitored between 2010 and 2018. Descriptive and explorative analyses were performed, including Kaplan-Meier estimators and the Cox regression model. Results The mean patient observation time was 42.9 months (SD = 35.1). The cumulative survival probabilities after 36 months—7.0% (GIC, N = 28), 29.9% (non-invasive composite restoration, N = 126), 76.2% (conventional composite restoration, N = 27) and 100.0% (ceramic restoration, N = 23)—differed significantly in the regression analysis. Conclusions Conventional restorations were associated with moderate-to-high survival rates in MIH teeth. In contrast, non-invasive composite restorations, which were predominately used in younger or less cooperative children, were linked to lower survival rates

Photosynthetic electron flow affects H2O2 signaling by inactivation of catalase in Chlamydomonas reinhardtii

A specific signaling role for H2O2 in Chlamydomonas reinhardtii was demonstrated by the definition of a promoter that specifically responded to this ROS. Expression of a nuclear-encoded reporter gene driven by this promoter was shown to depend not only on the level of exogenously added H2O2 but also on light. In the dark, the induction of the reporter gene by H2O2 was much lower than in the light. This lower induction was correlated with an accelerated disappearance of H2O2 from the culture medium in the dark. Due to a light-induced reduction in catalase activity, H2O2 levels in the light remained higher. Photosynthetic electron transport mediated the light-controlled down-regulation of the catalase activity since it was prevented by 3-(3′4′-dichlorophenyl)-1,1-dimethylurea (DCMU), an inhibitor of photosystem II. In the presence of light and DCMU, expression of the reporter gene was low while the addition of aminotriazole, a catalase inhibitor, led to a higher induction of the reporter gene by H2O2 in the dark. The role of photosynthetic electron transport and thioredoxin in this regulation was investigated by using mutants deficient in photosynthetic electron flow and by studying the correlation between NADP-malate dehydrogenase and catalase activities. It is proposed that, contrary to expectations, a controlled down-regulation of catalase activity occurs upon a shift of cells from dark to light. This down-regulation apparently is necessary to maintain a certain level of H2O2 required to activate H2O2-dependent signaling pathways

A Systematic Review of Argumentation Related to the Engineering-Designed World

Background Across academic disciplines, researchers have found that argumentation‐based pedagogies increase learners\u27 achievement and engagement. Engineering educational researchers and teachers of engineering may benefit from knowledge regarding how argumentation related to engineering has been practiced and studied. Purpose/Hypothesis Drawing from terms and concepts used in national standards for K‐12 education and accreditation requirements for undergraduate engineering education, this study was designed to identify how arguments and argumentation related to the engineering‐designed world were operationalized in relevant literature. Methodology Specified search terms and inclusion criteria were used to identify 117 empirical studies related to engineering argumentation and educational research. A qualitative content analysis was used to identify trends across these studies. Findings Overall, engineering‐related argumentation was associated with a variety of positive learner outcomes. Across many studies, arguments were operationalized in practice as statements regarding whether an existing technology should be adopted in a given context, usually with a limited number of supports (e.g., costs and ethics) provided for each claim. Relatively few studies mentioned empirical practices, such as tests. Most studies did not name the race/ethnicity of participants nor report engineering‐specific outcomes. Conclusions Engineering educators in K‐12 and undergraduate settings can create learning environments in which learners use a range of epistemic practices, including empirical practices, to support a range of claims. Researchers can study engineering‐specific outcomes while specifying relevant demographics of their research participants

Effects of Precursor Concentration and Acidic Sulfate in Aqueous Glyoxal−OH Radical Oxidation and Implications for Secondary Organic Aerosol

Previous experiments demonstrated that aqueous OH radical oxidation of glyoxal yields low-volatility compounds. When this chemistry takes place in clouds and fogs, followed by droplet evaporation (or if it occurs in aerosol water), the products are expected to remain partially in the particle phase, forming secondary organic aerosol (SOA). Acidic sulfate exists ubiquitously in atmospheric water and has been shown to enhance SOA formation through aerosol phase reactions. In this work, we investigate how starting concentrations of glyoxal (30−3000 μM) and the presence of acidic sulfate (0−840 μM) affect product formation in the aqueous reaction between glyoxal and OH radical. The oxalic acid yield decreased with increasing precursor concentrations, and the presence of sulfuric acid did not alter oxalic acid concentrations significantly. A dilute aqueous chemistry model successfully reproduced oxalic acid concentrations, when the experiment was performed at cloud-relevant concentrations (glyoxal <300 μM), but predictions deviated from measurements at increasing concentrations. Results elucidate similarities and differences in aqueous glyoxal chemistry in clouds and in wet aerosols. They validate for the first time the accuracy of model predictions at cloud-relevant concentrations. These results suggest that cloud processing of glyoxal could be an important source of SOA