1,664 research outputs found

    Gesellschaftliche Leistungen der biologischen Landwirtschaft

    Get PDF
    Zusammenfassuung: In diesem Bericht werden die wissenschaftlichen Ergebnisse nationaler und internationaler Studien zu den gesellschaftlichen Leistungen des Biolandbaus zusammengefasst. Als Referenzen werden dabei sowohl die konventionelle wie auch die integrierte Landwirtschaft herangezogen. Es ist den Autoren bewusst, dass alle Landwirtschaftsmethoden in der Schweiz und im Ausland eine grosse Streubreite aufweisen, da der Einfluss der regionalen sozioökonomischen Rahmenbedingungen, der Standortfaktoren, der Betriebsleiter und der unterschiedlichen staatlichen und privaten Regulierungen gross ist. Trotzdem ergeben sich fĂŒr die verschiedenen Landwirtschaftsmethoden klare Unterschiede, die bei den agrarpolitischen Massnahmen berĂŒcksichtigt werden mĂŒssen. BezĂŒglich der positiven ExternalitĂ€ten weist der Biolandbau klare Mehrleistungen in der BiodiversitĂ€t auf. Dies sowohl auf der Ebene der Genetik, der Arten und besonders auch der Habitate. Deutlich sind die Mehrleistungen des Biolandbaus auch im Bereich des Humusaufbaus, was eine höhere CO2-Sequestrierung zur Folge hat. Obwohl eine dauerhafte Honorierung der Vermeidung negativer ExternalitĂ€ten im bisherigen Konzept der Weiterentwicklung des Direktzahlungssystems (WDZ) nicht vorgesehen ist, sind hier die Vorteile der biologischen Landwirtschaft betrĂ€chtlich. Dies betrifft die NĂ€hrstoff- und Pflanzenschutzmittelverluste in Grund- und OberflĂ€chengewĂ€sser sowie in andere Umweltkompartimente, der Verbrauch von nicht erneuerbarer Energie, die Emissionen von Klimagasen und die Belastungen mit Tiermedikamenten. Die nationalen und internationalen Studien zeigen auf, dass der Biolandbau sich besonders durch Systemwirkungen auszeichnet: erhöhte BiodiversitĂ€t, verbesserter Schutz des Bodens, wirksame Vermeidung von Umweltbelastungen, effiziente Nutzung von natĂŒrlichen Ressourcen, geringer Verbrauch nicht erneuerbarer Energie und verbessertes Tierwohl. Dies sind die Effekte von komplexen Response-Massnahmen der Betriebsleiter auf einfach zu kontrollierende EinschrĂ€nkungen und Verbote. Dadurch entstehen nicht zu unterschĂ€tzende Zusatzleistungen und Synergien bei der Erreichung der vom Bund definierten Ziele. Um den Mehrleistungen des Biolandbaus gerecht zu werden, schlagen die Autoren zwei neue Massnahmen vor: 1) BiodiversitĂ€tsbeitrag fĂŒr Acker, Sonderkulturen und intensive Wiesen und 2) CO2-SequestrationsbeitrĂ€ge. Damit sind aber die gesellschaftlich wichtigen Mehrleistungen des Biolandbaus noch nicht abgegolten. Bei der Vermeidung negativer ExternalitĂ€ten werden höhere umweltschutzrelevante Effekte erzielt. Diese können i) durch die EinfĂŒhrung eines negativen Anreizsystems nach dem Polluter-Pays-Principle (z.B. Stickstoffsteuer, CO2 - Abgabe), ii) durch ein höheres Einstiegsniveau bei den Cross-Compliance-Massnahmen fĂŒr alle Betriebe (ÖLNplus) oder iii) durch einen finanziellen Ausgleich fĂŒr die Mehrleistungen des Biolandbaus abgegolten werden. Die „Förderung des Biolandbaus“ als systemorientierte Massnahme macht auch nach dem Grundsatz des effizienten Einsatzes von Steuermitteln Sinn und stellt eine kosteneffektive Massnahme dar. Einerseits können damit die deutlich höheren positiven ExternalitĂ€ten abgegolten werden, andererseits wird die stĂ€rkere Vermeidung von negativen ExternalitĂ€ten genĂŒgend berĂŒcksichtigt

    Abrupt changes in alpha decay systematics as a manifestation of collective nuclear modes

    Full text link
    An abrupt change in α\alpha decay systematics around the N=126 neutron shell closure is discussed. It is explained as a sudden hindrance of the clustering of the nucleons that eventually form the α\alpha particle. This is because the clustering induced by the pairing mode acting upon the four nucleons is inhibited if the configuration space does not allow a proper manifestation of the pairing collectivity.Comment: 6 pages, 3 figures, submitted to Phys. Rev. C, a few new references adde

    Alpha Decay Hindrance Factors: A Probe of Mean Field Wave Functions

    Full text link
    A simple model to calculate alpha-decay Hindrance Factors is presented. Using deformation values obtained from PES calculations as the only input, Hindrance Factors for the alpha-decay of Rn- and Po-isotopes are calculated. It is found that the intrinsic structure around the Fermi surface determined by the deformed mean field plays an important role in determining the hindrance of alpha-decay. The fair agreement between experimental and theoretical Hindrance Factors suggest that the wave function obtained from the energy minima of the PES calculations contains an important part of the correlations that play a role for the alpha-decay. The calculated HF that emerges from these calculations render a different interpretation than the commonly assumed n-particle n-hole picture.Comment: 7 pages, 9 figure

    Can Action Research Strengthen District Health Management and Improve Health Workforce Performance? A Research Protocol.

    Get PDF
    The single biggest barrier for countries in sub-Saharan Africa (SSA) to scale up the necessary health services for addressing the three health-related Millennium Development Goals and achieving Universal Health Coverage is the lack of an adequate and well-performing health workforce. This deficit needs to be addressed both by training more new health personnel and by improving the performance of the existing and future health workforce. However, efforts have mostly been focused on training new staff and less on improving the performance of the existing health workforce. The purpose of this paper is to disseminate the protocol for the PERFORM project and reflect on the key challenges encountered during the development of this methodology and how they are being overcome. The overall aim of the PERFORM project is to identify ways of strengthening district management in order to address health workforce inadequacies by improving health workforce performance in SSA. The study will take place in three districts each in Ghana, Tanzania and Uganda using an action research approach. With the support of the country research teams, the district health management teams (DHMTs) will lead on planning, implementation, observation, reflection and redefinition of the activities in the study. Taking into account the national and local human resource (HR) and health systems (HS) policies and practices already in place, 'bundles' of HR/HS strategies that are feasible within the context and affordable within the districts' budget will be developed by the DHMTs to strengthen priority areas of health workforce performance. A comparative analysis of the findings from the three districts in each country will add new knowledge on the effects of these HR/HS bundles on DHMT management and workforce performance and the impact of an action research approach on improving the effectiveness of the DHMTs in implementing these interventions. Different challenges were faced during the development of the methodology. These include the changing context in the study districts, competing with other projects and duties for the time of district managers, complexity of the study design, maintaining the anonymity and confidentiality of study participants as well as how to record the processes during the study. We also discuss how these challenges are being addressed. The dissemination of this research protocol is intended to generate interest in the PERFORM project and also stimulate discussion on the use of action research in complex studies such as this on strengthening district health management to improve health workforce performance

    Magnetization reversal of an individual exchange biased permalloy nanotube

    Get PDF
    We investigate the magnetization reversal mechanism in an individual permalloy (Py) nanotube (NT) using a hybrid magnetometer consisting of a nanometer-scale SQUID (nanoSQUID) and a cantilever torque sensor. The Py NT is affixed to the tip of a Si cantilever and positioned in order to optimally couple its stray flux into a Nb nanoSQUID. We are thus able to measure both the NT's volume magnetization by dynamic cantilever magnetometry and its stray flux using the nanoSQUID. We observe a training effect and temperature dependence in the magnetic hysteresis, suggesting an exchange bias. We find a low blocking temperature TB=18±2T_B = 18 \pm 2 K, indicating the presence of a thin antiferromagnetic native oxide, as confirmed by X-ray absorption spectroscopy on similar samples. Furthermore, we measure changes in the shape of the magnetic hysteresis as a function of temperature and increased training. These observations show that the presence of a thin exchange-coupled native oxide modifies the magnetization reversal process at low temperatures. Complementary information obtained via cantilever and nanoSQUID magnetometry allows us to conclude that, in the absence of exchange coupling, this reversal process is nucleated at the NT's ends and propagates along its length as predicted by theory.Comment: 8 pages, 4 figure

    Glasslike Arrest in Spinodal Decomposition as a Route to Colloidal Gelation

    Get PDF
    Colloid-polymer mixtures can undergo spinodal decomposition into colloid-rich and colloid-poor regions. Gelation results when interconnected colloid-rich regions solidify. We show that this occurs when these regions undergo a glass transition, leading to dynamic arrest of the spinodal decomposition. The characteristic length scale of the gel decreases with increasing quench depth, and the nonergodicity parameter exhibits a pronounced dependence on scattering vector. Mode coupling theory gives a good description of the dynamics, provided we use the full static structure as input.Comment: 14 pages, 4 figures; replaced with published versio

    Left bundle branch block causes relative but not absolute septal underperfusion during exercise

    Get PDF
    Aims Left bundle branch block (LBBB) often causes septal perfusion defects in radionuclide myocardial perfusion imaging using exercise (Ex) but rarely using vasodilator stress. We studied whether this is due to an underlying structural disease inherent to spontaneous LBBB or whether it is also found in temporary LBBB induced by right ventricular pacing (PM) indicating a functional rather than a structural alteration. Methods and results Regional myocardial blood flow (MBF) at rest and at Ex was measured with(15)O-H(2)O and PET in 10 age-matched healthy volunteers (controls), 10 LBBB patients and 10 PM patients with right ventricular pacing off and on (PM off and PM on). Although at Ex septal MBF tended to be higher in LBBB than in controls (3.04 +/- 1.18 vs. 2.27 +/- 0.72 mL/min/g; P= ns), the ratio septal/lateral MBF was 19% lower in LBBB than in controls (P < 0.05). Similarly, switching PM on at Ex decreased the ratio septal/lateral MBF by 17% (P < 0.005). Conclusion The apparent septal perfusion defect in LBBB is mainly due to a relative lateral hyperperfusion rather than to an absolute septal flow decrease. This pattern seems to be reversibly inducible by right ventricular pacing, suggesting a functional rather than a structural alteratio

    The catalytic subunit of Plasmodium falciparum casein kinase 2 is essential for gametocytogenesis

    Get PDF
    Casein kinase 2 (CK2) is a pleiotropic kinase phosphorylating substrates in different cellular compartments in eukaryotes. In the malaria parasite Plasmodium falciparum, PfCK2 is vital for asexual proliferation of blood-stage parasites. Here, we applied CRISPR/Cas9-based gene editing to investigate the function of the PfCK2alpha catalytic subunit in gametocytes, the sexual forms of the parasite that are essential for malaria transmission. We show that PfCK2alpha localizes to the nucleus and cytoplasm in asexual and sexual parasites alike. Conditional knockdown of PfCK2alpha expression prevented the transition of stage IV into transmission-competent stage V gametocytes, whereas the conditional knockout of pfck2a completely blocked gametocyte maturation already at an earlier stage of sexual differentiation. In summary, our results demonstrate that PfCK2alpha is not only essential for asexual but also sexual development of P. falciparum blood-stage parasites and encourage studies exploring PfCK2alpha as a potential target for dual-active antimalarial drugs

    Healthy aging in elderly cochlear implant recipients: a multinational observational study

    Get PDF
    Background: Given an increase in the aging population and its impact on healthcare systems, policy makers for provision of health and social services are aiming to keep older adults in good health for longer, in other words towards ‘healthy aging’. Our study objective is to show that rehabilitation with cochlear implant treatment in the elderly with hearing impairment improves the overall health-related quality of life and general well-being that translate into healthy aging. Methods: The multicentre, prospective, repeated measures, single-subject, clinical observational study will accrue 100 elderly, first-time, unilateral CI recipients (≄ 60 years) and analyze changes on specific measurement tools over ca. 20 months from preimplant to postimplant. Evaluations will consist of details collected through case history and interview questionnaires by clinicians, data logging, self-report questionnaires completed by the recipients and a series of commonly used audiometric measures and geriatric assessment tools. The primary indicator of changes in overall quality of life will be the HUI-3. Discussion: The protocol is designed to make use of measurement tools that have already been applied to the hearing-impaired population in order to compare effects of CI rehabilitation in adults immediately before their implantation, (pre-implant) and after gaining 1–1.5 years of experience (post-implant). The broad approach will lead to a greater understanding of how useful hearing impacts the quality of life in elderly individuals, and thus improves potentials for healthy aging. Outcomes will be described and analyzed in detail. Trial registration: This research has been registered in ClinicalTrials.gov (http://www.clinicaltrials.gov/), 7 March 2017 under the n° NCT03072862

    c-Maf enforces cytokine production and promotes memory-like responses in mouse and human type 2 innate lymphoid cells

    Get PDF
    Group-2 innate lymphoid cells (ILC2s), which are involved in type 2 inflammatory diseases such as allergy, can exhibit immunological memory, but the basis of this ILC2 "trained immunity" has remained unclear. Here, we found that stimulation with IL-33/IL-25 or exposure to the allergen papain induces the expression of the transcription factor c-Maf in mouse ILC2s. Chronic papain exposure results in high production of IL-5 and IL-13 cytokines and lung eosinophil recruitment, effects that are blocked by c-Maf deletion in ILCs. Transcriptomic analysis revealed that knockdown of c-Maf in ILC2s suppresses expression of type 2 cytokine genes, as well as of genes linked to a memory-like phenotype. Consistently, c-Maf was found highly expressed in human adult ILC2s but absent in cord blood and required for cytokine production in isolated human ILC2s. Furthermore, c-Maf-deficient mouse or human ILC2s failed to exhibit strengthened (“trained”) responses upon repeated challenge. Thus, the expression of c-Maf is indispensable for optimal type 2 cytokine production and proper memory-like responses in group-2 innate lymphoid cells
    • 

    corecore