432 research outputs found
Vom Zwang zur Pockenschutzimpfung zum Nationalen Impfplan
Im Deutschen Reich wurden Pockenschutzimpfungen staatlich organisiert. Eine reichsweite Impfpflicht wurde 1874 eingefĂŒhrt, die in der Bundesrepublik Deutschland (BRD) und Deutschen Demokratischen Republik (DDR) bis 1982/1983 fortgefĂŒhrt wurde. ZustĂ€ndig fĂŒr Impfungen waren die 1935 gegrĂŒndeten GesundheitsĂ€mter. In der DDR wurde das Impfwesen straff organisiert: Man unternahm groĂe Anstrengungen zur Erzielung hoher Impfquoten. Die diesbezĂŒglichen ZustĂ€ndigkeiten waren auf allen Ebenen und fĂŒr jedes Lebensalter klar definiert. WĂ€hrend es zunĂ€chst nur regionale Impfpflichten gab, enthielt der spĂ€tere Impfkalender in Form einer Rechtsvorschrift nationale Pflichtimpfungen beispielsweise gegen Masern. Auch in der BRD bestanden zunĂ€chst auf LĂ€nderebene vereinzelte Impfpflichten. Mit EinfĂŒhrung des Bundes-Seuchengesetzes 1961 setzte man auf freiwillige Impfungen basierend auf Impfempfehlungen. Seit den 1980er-Jahren verlagerte sich die DurchfĂŒhrung von Impfungen zunehmend vom öffentlichen Gesundheitsdienst (ĂGD) hin zu den niedergelassenen Ărzten. Inzwischen impft der ĂGD ĂŒberwiegend nur noch subsidiĂ€r und 2007 wurden Impfungen Pflichtleistungen der gesetzlichen Krankenkassen. Die LĂ€nder entwickelten unlĂ€ngst zur Förderung von Impfstrategien einen Nationalen Impfplan.In the German Reich, smallpox vaccinations were organized by the state. A mandatory vaccination throughout the empire was introduced in 1874, which was continued in the Federal Republic of Germany (FRG) and the German Democratic Republic (GDR) until 1982/1983. From 1935, health departments were responsible for vaccinations. In the GDR, immunization was tightly organized: The state made great efforts to achieve high vaccination rates. Responsibilities were clearly defined at all levels and for all ages. While vaccination was initially mandatory only at the regional level, the legally mandated immunization schedule later contained compulsory vaccinations, e.g., against measles. In the beginning there were mandatory vaccinations in the FRG at the LĂ€nder level. Since 1961, the Federal Epidemics Act has impeded obligatory vaccinations. Instead, voluntary vaccinations based on recommendations were stressed. Since the 1980s, vaccinations have been shifted from the public health service sector to office-based physicians. Today, public health authorities offer mainly supplementary vaccinations. In 2007, protective immunizations were introduced as compulsory benefits of the statutory health insurance (SHI). Recently, the German federal states developed a National Vaccination Plan to support immunization strategies
Counteranion and Solvent Assistance in Ruthenium-Mediated Alkyne to Vinylidene Isomerizations
The complex [Cp*RuCl(iPr2PNHPy)] (1) reacts with 1-alkynes HCâĄCR (R = COOMe, C6H4CF3) in
dichloromethane furnishing the corresponding vinylidene complexes [Cp*RuâĄCâĄCHR(iPr2PNHPy)]Cl (R = COOMe (2a-
Cl), C6H4CF3 (2b-Cl)), whereas reaction of 1 with NaBPh4 in MeOH followed by addition of HCâĄCR (R = COOMe,
C6H4CF3) yields the metastable Ï-alkyne complexes [Cp*Ru(η2-HCâĄCR)(iPr2PNHPy)][BPh4] (R = COOMe (3a-BPh4),
C6H4CF3 (3b-BPh4)). The transformation of 3a-BPh4/3b-BPh4 into their respective vinylidene isomers in dichloromethane is
very slow and requires hours to its completion. However, this process is accelerated by addition of LiCl in methanol solution.
Reaction of 1 with HCâĄCR (R = COOMe, C6H4CF3) in MeOH goes through the intermediacy of the Ï-alkyne complexes
[Cp*Ru(η2-HCâĄCR)(iPr2PNHPy)]Cl (R = COOMe (3a-Cl), C6H4CF3 (3b-Cl)), which rearrange to vinylidenes in minutes,
i.e., much faster than their counterparts containing the [BPh4]â anion. The kinetics of these isomerizations has been studied in
solution by NMR. With the help of DFT studies, these observations have been interpreted in terms of chloride- and methanolassisted
hydrogen migrations. Calculations suggest participation of a hydridoâalkynyl intermediate in the process, in which the
hydrogen atom can be transferred from the metal to the ÎČ-carbon by means of species with weak basic character acting as proton
shuttles
North American extreme precipitation events and related large-scale meteorological patterns: a review of statistical methods, dynamics, modeling, and trends
This paper surveys the current state of knowledge regarding large-scale meteorological patterns (LSMPs) associated with short-duration (less than 1 week) extreme precipitation events over North America. In contrast to teleconnections, which are typically defined based on the characteristic spatial variations of a meteorological field or on the remote circulation response to a known forcing, LSMPs are defined relative to the occurrence of a specific phenomenon-here, extreme precipitation-and with an emphasis on the synoptic scales that have a primary influence in individual events, have medium-range weather predictability, and are well-resolved in both weather and climate models. For the LSMP relationship with extreme precipitation, we consider the previous literature with respect to definitions and data, dynamical mechanisms, model representation, and climate change trends. There is considerable uncertainty in identifying extremes based on existing observational precipitation data and some limitations in analyzing the associated LSMPs in reanalysis data. Many different definitions of "extreme" are in use, making it difficult to directly compare different studies. Dynamically, several types of meteorological systems-extratropical cyclones, tropical cyclones, mesoscale convective systems, and mesohighs-and several mechanisms-fronts, atmospheric rivers, and orographic ascent-have been shown to be important aspects of extreme precipitation LSMPs. The extreme precipitation is often realized through mesoscale processes organized, enhanced, or triggered by the LSMP. Understanding of model representation, trends, and projections for LSMPs is at an early stage, although some promising analysis techniques have been identified and the LSMP perspective is useful for evaluating the model dynamics associated with extremes.11Ysciescopu
Versatile Coordination of Cyclopentadienyl-Arene Ligands and Its Role in Titanium-Catalyzed Ethylene Trimerization
Cationic titanium(IV) complexes with ansa-(η5-cyclopentadienyl,η6-arene) ligands were synthesized and characterized by X-ray crystallography. The strength of the metal-arene interaction in these systems was studied by variable-temperature NMR spectroscopy. Complexes with a C1 bridge between the cyclopentadienyl and arene moieties feature hemilabile coordination behavior of the ligand and consequently are active ethylene trimerization catalysts. Reaction of the titanium(IV) dimethyl cations with CO results in conversion to the analogous cationic titanium(II) dicarbonyl species. Metal-to-ligand backdonation in these formally low-valent complexes gives rise to a strongly bonded, partially reduced arene moiety. In contrast to the η6-arene coordination mode observed for titanium, the more electron-rich vanadium(V) cations [cyclopentadienyl-arene]V(NiPr2)(NC6H4-4-Me)+ feature η1-arene binding, as determined by a crystallographic study. The three different metal-arene coordination modes that we experimentally observed model intermediates in the cycle for titanium-catalyzed ethylene trimerization. The nature of the metal-arene interaction in these systems was studied by DFT calculations.
TURBOMOLE: Modular program suite for ab initio quantum-chemical and condensed-matter simulations
TURBOMOLE is a collaborative, multi-national software development project aiming to provide highly efficient and stable computational tools for quantum chemical simulations of molecules, clusters, periodic systems, and solutions. The TURBOMOLE software suite is optimized for widely available, inexpensive, and resource-efficient hardware such as multi-core workstations and small computer clusters. TURBOMOLE specializes in electronic structure methods with outstanding accuracyâcost ratio, such as density functional theory including local hybrids and the random phase approximation (RPA), GW-BetheâSalpeter methods, second-order MĂžllerâPlesset theory, and explicitly correlated coupled-cluster methods. TURBOMOLE is based on Gaussian basis sets and has been pivotal for the development of many fast and low-scaling algorithms in the past three decades, such as integral-direct methods, fast multipole methods, the resolution-of-the-identity approximation, imaginary frequency integration, Laplace transform, and pair natural orbital methods. This review focuses on recent additions to TURBOMOLEâs functionality, including excited-state methods, RPA and Greenâs function methods, relativistic approaches, high-order molecular properties, solvation effects, and periodic systems. A variety of illustrative applications along with accuracy and timing data are discussed. Moreover, available interfaces to users as well as other software are summarized. TURBOMOLEâs current licensing, distribution, and support model are discussed, and an overview of TURBOMOLEâs development workflow is provided. Challenges such as communication and outreach, software infrastructure, and funding are highlighted
TURBOMOLE: Modular program suite for ab initio quantum-chemical and condensed-matter simulations
TURBOMOLE is a collaborative, multi-national software development project aiming to provide highly efficient and stable computational tools for quantum chemical simulations of molecules, clusters, periodic systems, and solutions. The TURBOMOLE software suite is optimized for widely available, inexpensive, and resource-efficient hardware such as multi-core workstations and small computer clusters. TURBOMOLE specializes in electronic structure methods with outstanding accuracyâcost ratio, such as density functional theory including local hybrids and the random phase approximation (RPA), GW-BetheâSalpeter methods, second-order MĂžllerâPlesset theory, and explicitly correlated coupled-cluster methods. TURBOMOLE is based on Gaussian basis sets and has been pivotal for the development of many fast and low-scaling algorithms in the past three decades, such as integral-direct methods, fast multipole methods, the resolution-of-the-identity approximation, imaginary frequency integration, Laplace transform, and pair natural orbital methods. This review focuses on recent additions to TURBOMOLEâs functionality, including excited-state methods, RPA and Greenâs function methods, relativistic approaches, high-order molecular properties, solvation effects, and periodic systems. A variety of illustrative applications along with accuracy and timing data are discussed. Moreover, available interfaces to users as well as other software are summarized. TURBOMOLEâs current licensing, distribution, and support model are discussed, and an overview of TURBOMOLEâs development workflow is provided. Challenges such as communication and outreach, software infrastructure, and funding are highlighted
Unresolved issues and new challenges in teaching English to young learners:the case of South Korea
The introduction of languages, especially English, into the primary curriculum around the world has been one of the major language-in-education policy developments in recent years. In countries where English has been compulsory for a number of years, the question arises as to what extent the numerous and well-documented challenges faced by the initial implementation of early language learning policies have been overcome and whether new challenges have arisen as policies have become consolidated. This article therefore focuses on South Korea, where English has been compulsory in primary school since 1997. The issues raised by the introduction of English into the primary curriculum are reviewed and the current situation in South Korea is investigated. The results of a mixed methods study using survey data from 125 Korean primary school teachers, together with data from a small-scale case study of one teacher are presented. The study shows that, while some of the initial problems caused by the introduction of early language learning appear to have been addressed, other challenges persist. Moreover, the data reveal the emergence of a number of new challenges faced by primary school teachers of English as they seek to implement government policy
Present day greenhouse gases could cause more frequent and longer Dust Bowl heatwaves
Substantial warming occurred across North America, Europe and the Arctic over the early twentieth century1, including an increase in global drought2, that was partially forced by rising greenhouse gases (GHGs)3. The period included the 1930s Dust Bowl drought4,5,6,7 across North Americaâs Great Plains that caused widespread crop failures4,8, large dust storms9 and considerable out-migration10. This coincided with the central United States experiencing its hottest summers of the twentieth century11,12 in 1934 and 1936, with over 40 heatwave days and maximum temperatures surpassing 44â°C at some locations13,14. Here we use a large-ensemble regional modelling framework to show that GHG increases caused slightly enhanced heatwave activity over the eastern United States during 1934 and 1936. Instead of asking how a present-day heatwave would behave in a world without climate warming, we ask how these 1930s heatwaves would behave with present-day GHGs. Heatwave activity in similarly rare events would be much larger under todayâs atmospheric GHG forcing and the return period of a 1-in-100-year heatwave summer (as observed in 1936) would be reduced to about 1-in-40âyears. A key driver of the increasing heatwave activity and intensity is reduced evaporative cooling and increased sensible heating during dry springs and summers
Ocean and land forcing of the record-breaking Dust Bowl heat waves across central United States
International audienceThe severe drought of the 1930s Dust Bowl decade coincided with record-breaking summer heatwaves that contributed to the socioeconomic and ecological disaster over North America's Great Plains. It remains unresolved to what extent these exceptional heatwaves, hotter than in historically forced coupled climate model simulations, were forced by sea surface temperatures (SSTs) and exacerbated through human-induced deterioration of land cover. Here we show, using an atmospheric-only model, that anomalously warm North Atlantic SSTs enhance heatwave activity through an association with drier spring conditions resulting from weaker moisture transport. Model devegetation simulations, that represent the widespread exposure of bare soil in the 1930s, suggest human activity fueled stronger and more frequent heatwaves through greater evaporative drying in the warmer months. This study highlights the potential for the amplification of naturally occurring extreme events like droughts by vegetation feedbacks to create more extreme heatwaves in a warmer world
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