A new solution for mirror coating in γ\gamma-ray Cherenkov Astronomy

In the $\gamma$-ray Cherenkov Astronomy framework mirror coating plays a crucial role in defining the light response of the telescope. We carried out a study for new mirror coating solutions with both a numerical simulation software and a vacuum chamber for small sample production. In this article, we present a new mirror coating solution consisting of a 28-layer interferometric SiO$_{2}$-TiO$_{2}$-HfO$_{2}$ design deposited on a glass substrate, whose average reflectance is above $90\%$ for normally incident light in the wavelength range between 300 and 550 nm.Comment: 6 pages, 5 figures. Article submitted to Experimental Astronomy, the final publication is available at link.springer.co

The Role Of Genetic And Phenotypic Variation In The Colonization Biology Of The Weedy Nightshade, Solanum Ptycanthum Dun

Solanum ptycanthum (eastern black nightshade) is a serious weed of tomato and soybean crops at the northern margin of its distribution in southwestern Ontario. Evidence for direct immigration, albeit at low, sporadic frequencies, of nightshade into these agrestal habitats occurs via tomato transplants imported from Georgia and North Carolina. Northern ruderal populations are also common in a variety of natural habitats. Outcrossing rates in northern and southern genotypes were compared in simulated populations grown in northern agricultural habitats. Greenhouse experiments were used to examine levels of genetic variation and phenotypic plasticity in life history traits among ruderal, agrestal and southern populations in response to abiotic factors which would be experienced when invading northern agroecosystems.;Genotypes from recently colonized northern populations (both agrestal and ruderal) had lower outcrossing rates ({dollar}\u3c{dollar}3%) than those originating from the south (3-17%).;Northern agrestal populations were not less genetically variable, and did not express greater phenotypic plasticity than northern ruderal or southern agrestal populations under a wide range of greenhouse conditions. Germination speed was greater, and the number of degree days to reach 50% germination was less in ruderal families, suggesting that ruderal populations would emerge earlier than agrestal populations. The germination response to temperature was similar between northern and southern agrestal populations, suggesting that these populations would emerge synchronously.;Ruderal and northern agrestal populations were equally tolerant to low doses of metribuzin, while populations originating from Georgia were extremely susceptible to both levels of metribuzin tested. North Carolina seedlings were as tolerant as northern agrestal populations. Northern agrestal populations were more tolerant than ruderal populations at the highest dose of metribuzin.;There was no divergence in the phenotype expressed by ruderal and northern agrestal individuals in response to variation in nutrients. There was no evidence for selection for increased yield response in agrestals grown under high nutrient conditions. However, delayed reproduction of southern compared to northern plants may limit the production of viable seed in northern short-season crops. Developmental pattern and age to first reproduction were canalized within southern populations, suggesting lack of sufficient genetic variability to respond to selection encountered during colonization of northern agroecosystems

Profiling Regional Watershed Management on the Northeast Avalon: Integrating Practices for Drinking Water Quality

This study investigated watershed management in the Northeast Avalon (NEA) region and six targeted municipalities by 1) mapping watershed boundaries and intactness to inform water and wetland management; and 2) understanding the issues around drinking water in each municipality. Residents, planners, developers and municipal staff were interviewed. Many of the watersheds have experienced significant development resulting in a loss of watershed health; few areas have large intact areas remaining. As larger watersheds are shared among municipalities, it is imperative that a planning platform be developed to engage and promote regional planning to ensure watershed health and sustainable drinking water into the future. Mechanisms that encourage as well as discourage regional collaboration around issues of watershed management are outlined

Entwicklung von Cs 2 Te Photokathoden für UV-Detektoren

Das Ziel vieler wissenschaftlicher Untersuchungen ist die Messung des Lichtspektrums eines astronomischen Objekts, um daraus Rückschlüsse auf seine chemische Komposition und makroskopische Eigenschaften wie Masse, Ausdehnung, Temperatur und Abstand zur Erde zu ermitteln. Für astronomische Beobachtungen im ultravioletten Bereich werden zudem Satelliten benötigt, da die Erdatmosphäre einen Großteil der auftreffenden Strahlung absorbiert. Am Institut für Astronomie und Astrophysik Tübingen (IAAT) wird daher basierend auf den Erfahrungen mit früheren Instrumenten, namentlich das Orbitale und Rückführbare Fern- und Extremultraviolett Spektrometer (ORFEUS) von 1990, ein photonenzählender, ortsauflösender Mikrokanalplattendetektor für den Einsatz in einem Spektrographen entwickelt. Diese Entwicklung wurde ursprünglich durch die potentielle Teilnahme an einem russisch-deutschen Gemeinschaftsprojekt, dem World Space Observatory (WSO/UV), angestoßen und wird seit 2013 durch das deutsche Zentrum für Luft und Raumfahrt als allgemeine Detektorentwicklung gefördert. Wird ein Spektrograph eingesetzt, spaltet dieser das aufgefangene Licht entsprechend seiner Wellenlänge räumlich auf und leitet es auf den Detektor, der nur noch den Ort der auftreffenden Photonen messen muss. Unser Detektor besteht daher aus einer Photokathode, mehreren Mikrokanalplatten und einer Anode. Die Photokathode wandelt ein einzelnes auftreffendes Photon in ein Elektron um, das von den Mikrokanalplatten vervielfältigt wird, sodass eine Elektronenwolke auf die Anode trifft. Dort wird der Ladungsmittelpunkt der auftreffenden Ladungswolke bestimmt und daraus die Ursprungsposition des Photons errechnet und in Kombination mit dem Wissen um die Aufspaltung im Spektrographen ist damit die Wellenlänge des ursprünglichen Photons bekannt. Der Schwerpunkt dieser Arbeit liegt auf der Entwicklung der Photokathoden für den Detektor. Im Zuge dessen wurde ein neuer Versuchsaufbau in Betrieb genommen und für die Herstellung von Cäsiumtellurid-Photokathoden optimiert. In der vorliegenden Arbeit werden im ersten Kapitel die Grundlagen von Detektoren für UVAnwendungen mit Schwerpunkt auf den verwendeten Mikrokanalplattendetektoren beschrieben und die technischen Herausforderungen am Beispiel von ORFEUS und anderen UV-Instrumenten herausgearbeitet. Zusätzlich werden das Detektorkonzept, das am IAAT entwickelt wurde, sowieder aktuelle Stand der Entwicklung vorgestellt. Im zweiten Kapitel wird ein Überblick über die theoretische Funktionsweise von Photokathoden geliefert, sowie exemplarisch an drei relevanten Materialien erörtert, die ebenfalls potentiell in unserem Detektor eingesetzt werden sollen. Der Schwerpunkt liegt auf den Eigenschaften von Cäsiumtellurid, da es als besonders zuverlässig gilt. Im dritten Kapitel werden der vorhandene Versuchsaufbau im Detail beschrieben, sowie die Änderungen, Optimierungen und Probleme skizziert, die im Laufe der letzten vier Jahre auftraten. Anschließend werden mögliche Verbesserungen und Änderungen aufgezeigt, die in nächster Zeit implementiert werden sollen und eine weitere Verbesserung der Ergebnisse versprechen. Weiterhin werden die Versuche zu Germaniumschichten auf geschlossenen Anoden angesprochen und die technische Realisierung beschrieben. Im vierten Kapitel wird der zeitliche Ablauf der Arbeit skizziert, die gefundene Standardprozedur zur Herstellung von Cäsiumtellurid-Photokathoden beschrieben und die dazu gehörigen Messergebnisse vorgestellt. Es werden die Versuche an kalten und warmen Substraten, sowie die neuesten Erkenntnisse von Photokathoden auf einer zusätzlichen leitenden Metallschicht vorgestellt. Insgesamt wird mit dieser Arbeit die Grundlage für die Herstellung von Photokathoden für den Einsatz in unserem Detektor gelegt und deren Erfolg durch erste vielversprechende Proben belegt

Gatekeeping effects of a publisher on daily newspapers a case study of the Windsor Star.

Dept. of Communication Studies. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1985 .H475. Source: Masters Abstracts International, Volume: 40-07, page: . Thesis (M.A.)--University of Windsor (Canada), 1985

Early Career Teachers\u27 Efficacy in Working with Families

Partnering effectively with families is an important skill for teachers to have to support student achievement, and one that is especially important for early career teachers in order to protect them from burnout and attrition. However, research has demonstrated that teachers do not feel prepared to work with families, and further research is needed to see what difficulties are specific to early career teachers. The following research questions were addressed in the study: 1) What current situation and prior training factors affect early career teachers’ perceptions of efficacy in working with families? 2) Which family-school partnering topics do teachers report the most experience in their prior preparation programs and in their current daily practice? 3) Is there a relationship between number of years reported teaching and overall efficacy scores? 4) What family-school partnering training do early career teachers believe would have been or would be beneficial to receive in their teacher preparation programs versus during their first five years of practice? A survey was created which included a pre-existing self-efficacy scale adapted to reflect family partnering language. This survey was disseminated to 76 first through fifth year Colorado teachers. Results indicate that age of current school placement had a significant effect on overall self-efficacy scale scores, while several other variables had an effect on subscales of the efficacy scale. Recommendations are presented for future research, teacher preparation programs, and school district mentoring

Captan Toxicity to Fathead Minnows (\u3ci\u3ePimephales promelas\u3c/i\u3e), Bluegills (\u3ci\u3eLepomis macrochirus\u3c/i\u3e), and Brook Trout (\u3ci\u3eSalvelinus fontinalis\u3c/i\u3e)

The toxic effects of capt an on survival, growth, and reproduction of fathead minnows (Pimephales promelas) and on survival of bluegiIIs (Lepomis macrochirus) and brook trout (Salvelinus fontinalis) were determined in a flow-through system. In a 45-week exposure of fathead minnows, survival and growth were adversely affected at 39.5 μLg/Iiter. Adverse effects on spawning were suspected but not statisticaIly demonstrated at 39.5 and 16.5 μLg/Iiter. The maximum acceptable toxicant concentration (MATC), based on survival and growth, lies between 39.5 and 16.5 μLg/liter. The lethal threshold concentration (LTC) derived from acute exposures was 64 μLg/liter, resulting in an application factor (MATC/LTC) between 0.26 and 0.62. LTC values for the bluegill and brook trout were 72 and 29 μLg/liter, respectively. The estimated MATC is between 44.6 and 18.7 μLg/liter for the bluegill and between 18.0 and 7.5 μLg/liter for the brook trout. The half-life of captan in Lake Superior water with a pH of 7.6 is about 7 hr at 12 C and about 1 hr at 25 C. Breakdown products from an initial 550 μLg/Iiter of captan were not lethal to 3-month-old fathead minnows

The effect of clone size on seed production in Canada goldenrod, Solidago canadensis L.

Source: Masters Abstracts International, Volume: 40-07, page: . Thesis (M.Sc.)--University of Windsor (Canada), 1981

Comparison of the collagen haemostat Sangustop(R) versus a carrier-bound fibrin sealant during liver resection; ESSCALIVER-study

Background: Haemostasis in liver surgery remains a challenge despite improved resection techniques. Oozing from blood vessels too small to be ligated necessitate a treatment with haemostats in order to prevent complications attributed to bleeding. There is good evidence from randomised trials for the efficacy of fibrin sealants, on their own or in combination with a carrier material. A new haemostatic device is Sangustop(R). It is a collagen based material without any coagulation factors. Pre-clinical data for Sangustop(R) showed superior haemostatic effect. This present study aims to show that in the clinical situation Sangustop(R) is not inferior to a carrier-bound fibrin sealant (Tachosil(R)) as a haemostatic treatment in hepatic resection. Methods: This is a multi-centre, patient-blinded, intra-operatively randomised controlled trial. A total of 126 patients planned for an elective liver resection will be enrolled in eight surgical centres. The primary objective of this study is to show the non-inferiority of Sangustop(R) versus a carrier-bound fibrin sealant (Tachosil(R)) in achieving haemostasis after hepatic resection. The surgical intervention is standardised with regard to devices and techniques used for resection and primary haemostasis. Patients will be followed-up for three months for complications and adverse events. Discussion: This randomised controlled trial (ESSCALIVER) aims to compare the new collagen haemostat Sangustop(R) with a carrier-bound fibrin sealant which can be seen as a "gold standard" in hepatic and other visceral organ surgery. If non-inferiority is shown other criteria than the haemostatic efficacy (e.g. costs, adverse events rate) may be considered for the choice of the most appropriate treatment. Trial Registration: NCT0091861