103 research outputs found
Einstellung von Schülern zu Schule und Sachunterricht:Erfassung und Differenzierung von typologischen Einstellungsausprägungen bei Grundschülern
Zur Erfassung der Einstellung von Grundschulkindern zur Schule und zum Sachunterricht wurde ein Erhebungsinstrument im Sinne der klassischen Testtheorie und Testkonstruktion (z.B. Rost, 1996) entwickelt. Dieses Instrument ist ein systematisch konstruierter Fragebogen mit vier verschiedenen Subskalen („Schule und Lernen“, „Bedeutung von Lernen im Sachunterricht“, „Verhalten zu Mitschülern“, „didaktischmethodische Ausgestaltung des Sachunterrichts“), das letztlich mit insgesamt 29 Items (von zuvor 87 Items) die Einstellung der Schüler zu Schule und Sachunterricht operationalisiert. Mit diesem Instrument wurden insgesamt 344 Grundschüler der Jahrgangsstufen 1-4 befragt. Mit Hilfe spezifischer, statistischer Verfahren konnten drei „Einstellungstypen“ identifiziert und beschrieben werden: Der Lernfreude-Typ, der Gelangweilt-Frustrierte Typ und der Zielorientierte Leistungs-Typ. Die didaktisch-methodische Ausgestaltung des Sachunterrichtes im Schülerurteil hat einen bedeutenden Einfluss auf die Lernprozesse. Deshalb stehen mögliche didaktisch-methodische Konsequenzen für den Sach- bzw. Biologieunterricht im Focus des Interesses
Is there a Jordan geometry underlying quantum physics?
There have been several propositions for a geometric and essentially
non-linear formulation of quantum mechanics. From a purely mathematical point
of view, the point of view of Jordan algebra theory might give new strength to
such approaches: there is a ``Jordan geometry'' belonging to the Jordan part of
the algebra of observables, in the same way as Lie groups belong to the Lie
part. Both the Lie geometry and the Jordan geometry are well-adapted to
describe certain features of quantum theory. We concentrate here on the
mathematical description of the Jordan geometry and raise some questions
concerning possible relations with foundational issues of quantum theory.Comment: 30 page
Nonparametric Information Geometry
The differential-geometric structure of the set of positive densities on a
given measure space has raised the interest of many mathematicians after the
discovery by C.R. Rao of the geometric meaning of the Fisher information. Most
of the research is focused on parametric statistical models. In series of
papers by author and coworkers a particular version of the nonparametric case
has been discussed. It consists of a minimalistic structure modeled according
the theory of exponential families: given a reference density other densities
are represented by the centered log likelihood which is an element of an Orlicz
space. This mappings give a system of charts of a Banach manifold. It has been
observed that, while the construction is natural, the practical applicability
is limited by the technical difficulty to deal with such a class of Banach
spaces. It has been suggested recently to replace the exponential function with
other functions with similar behavior but polynomial growth at infinity in
order to obtain more tractable Banach spaces, e.g. Hilbert spaces. We give
first a review of our theory with special emphasis on the specific issues of
the infinite dimensional setting. In a second part we discuss two specific
topics, differential equations and the metric connection. The position of this
line of research with respect to other approaches is briefly discussed.Comment: Submitted for publication in the Proceedings od GSI2013 Aug 28-30
2013 Pari
Fredholmness of Toeplitz operators on the Fock space
The Fredholm property of Toeplitz operators on the -Fock spaces on is studied. A general Fredholm criterion for arbitrary operators from the Toeplitz algebra on in terms of the invertibility of limit operators is derived. This paper is based on previous work, which establishes corresponding results on the unit balls
Naïve and informed views on the nature of scientific inquiry in large-scale assessments: Two sides of the same coin or different currencies
Many models in the field of epistemic cognition conceptualize students' views as being on a continuum between the poles of naïve and informed views. Against this background, the aim of the present study was to find out whether views on the nature of scientific inquiry (NOSI views) should be conceptualized and quantitatively assessed in a more multiplistic manner, considering naïve and informed views in their own, separate dimensions. Based on a competence model defining three inquiry methods, we developed a Likert-scaled questionnaire containing 10 scales, each assessing one NOSI view. We administered the questionnaire to a sample of 802 students in the lower and upper levels of secondary school. Based on structural equation modeling, the analyses confirmed a 10-dimensional model, distinguishing between each naïve and informed views as the only adequate representation of the data. Latent class analysis and interview data revealed four profiles of NOSI views in the data, which differed with regard to their agreement or disagreement with different naïve and informed views. We interpret these findings as evidence that supports more multiplistic models, with relevance to conceptualizing, measuring, and fostering NOSI views. We derive future directions of nature of science and NOSI research linking basic and applied research using experimental studies. © 2019 The Author. Journal of Research in Science Teaching published by Wiley Periodicals, Inc
Metabolomic profiles predict individual multidisease outcomes
Publisher Copyright: © 2022, The Author(s).Risk stratification is critical for the early identification of high-risk individuals and disease prevention. Here we explored the potential of nuclear magnetic resonance (NMR) spectroscopy-derived metabolomic profiles to inform on multidisease risk beyond conventional clinical predictors for the onset of 24 common conditions, including metabolic, vascular, respiratory, musculoskeletal and neurological diseases and cancers. Specifically, we trained a neural network to learn disease-specific metabolomic states from 168 circulating metabolic markers measured in 117,981 participants with ~1.4 million person-years of follow-up from the UK Biobank and validated the model in four independent cohorts. We found metabolomic states to be associated with incident event rates in all the investigated conditions, except breast cancer. For 10-year outcome prediction for 15 endpoints, with and without established metabolic contribution, a combination of age and sex and the metabolomic state equaled or outperformed established predictors. Moreover, metabolomic state added predictive information over comprehensive clinical variables for eight common diseases, including type 2 diabetes, dementia and heart failure. Decision curve analyses showed that predictive improvements translated into clinical utility for a wide range of potential decision thresholds. Taken together, our study demonstrates both the potential and limitations of NMR-derived metabolomic profiles as a multidisease assay to inform on the risk of many common diseases simultaneously.Peer reviewe
Critical evaluation of key evidence on the human health hazards of exposure to bisphenol A
Despite the fact that more than 5000 safety-related studies have been published on bisphenol A (BPA), there seems to be no resolution of the apparently deadlocked controversy as to whether exposure of the general population to BPA causes adverse effects due to its estrogenicity. Therefore, the Advisory Committee of the German Society of Toxicology reviewed the background and cutting-edge topics of this BPA controversy. The current tolerable daily intake value (TDI) of 0.05 mg/kg body weight [bw]/day, derived by the European Food Safety Authority (EFSA), is mainly based on body weight changes in two- and three-generation studies in mice and rats. Recently, these studies and the derivation of the TDI have been criticized. After having carefully considered all arguments, the Committee had to conclude that the criticism was scientifically not justified; moreover, recently published additional data further support the reliability of the two-and three-generation studies demonstrating a lack of estrogen-dependent effects at and below doses on which the current TDI is based. A frequently discussed topic is whether doses below 5 mg/ kg bw/day may cause adverse health effects in laboratory animals. Meanwhile, it has become clear that positive results from some explorative studies have not been confirmed in subsequent studies with higher numbers of animals or a priori defined hypotheses. Particularly relevant are some recent studies with negative outcomes that addressed effects of BPA on the brain, behavior, and the prostate in rodents for extrapolation to the human situation. The Committee came to the conclusion that rodent data can well be used as a basis for human risk evaluation. Currently published conjectures that rats are insensitive to estrogens compared to humans can be refuted. Data from toxicokinetics studies show that the half-life of BPA in adult human subjects is less than 2 hours and BPA is completely recovered in urine as BPA-conjugates. Tissue deconjugation of BPA-glucuronide and -sulfate may occur. Because of the extremely low quantities, it is only of minor relevance for BPA toxicity. Biomonitoring studies have been used to estimate human BPA exposure and show that the daily intake of BPA is far below the TDI for the general population. Further topics addressed in this article include reasons why some studies on BPA are not reproducible; the relevance of oral versus non-oral exposure routes; the degree to which newborns are at higher systemic BPA exposure; increased BPA exposure by infusions in intensive care units; mechanisms of action other than estrogen receptor activation; and the current regulatory status in Europe, as well as in the USA, Canada, Japan, New Zealand, and Australia. Overall, the Committee concluded that the current TDI for BPA is adequately justified and that the available evidence indicates that BPA exposure represents no noteworthy risk to the health of the human population, including newborns and babies
The Biochemical and Cellular Basis for Nutraceutical Strategies to Attenuate Neurodegeneration in Parkinson’s Disease
Future therapeutic intervention that could effectively decelerate the rate of degeneration within the substantia nigra pars compacta (SNc) could add years of mobility and reduce morbidity associated with Parkinson’s disease (PD). Neurodegenerative decline associated with PD is distinguished by extensive damage to SNc dopaminergic (DAergic) neurons and decay of the striatal tract. While genetic mutations or environmental toxins can precipitate pathology, progressive degenerative succession involves a gradual decline in DA neurotransmission/synaptic uptake, impaired oxidative glucose consumption, a rise in striatal lactate and chronic inflammation. Nutraceuticals play a fundamental role in energy metabolism and signaling transduction pathways that control neurotransmission and inflammation. However, the use of nutritional supplements to slow the progression of PD has met with considerable challenge and has thus far proven unsuccessful. This review re-examines precipitating factors and insults involved in PD and how nutraceuticals can affect each of these biological targets. Discussed are disease dynamics (Sections 1 and 2) and natural substances, vitamins and minerals that could impact disease processes (Section 3). Topics include nutritional influences on α-synuclein aggregation, ubiquitin proteasome function, mTOR signaling/lysosomal-autophagy, energy failure, faulty catecholamine trafficking, DA oxidation, synthesis of toxic DA-quinones, o-semiquinones, benzothiazolines, hyperhomocyseinemia, methylation, inflammation and irreversible oxidation of neuromelanin. In summary, it is clear that future research will be required to consider the multi-faceted nature of this disease and re-examine how and why the use of nutritional multi-vitamin-mineral and plant-based combinations could be used to slow the progression of PD, if possible
Non-perturbative Deformation Quantization of Cartan Domains
AbstractWe construct families of non-commuting C*-algebras of "quantized functions" for bounded irreducible Hermitian symmetric spaces. For this procedure, we use algebras of Toeplitz operators defined with respect to a perturbation of the ordinary Bergman metric. We prove the deformation quantization conditions for these algebras
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