Schülervorstellungen zu Bedrohung und Verwundbarkeit durch den globalen Klimawandel

The investigation of students' ideas and pre-instructional conceptions has become one of the most important fields of science education research. While some studies have investigated students' mental models of the greenhouse effect already, only little is known about students' ideas concerning the impacts of climate change and the vulnerability of people in different regions of the world. This study analysises students’ ideas about the vulnerability of people in Germany and Africa due to global climate change. The study is based on interviews with 25 students aged 18-19 from different schools in Germany. All in all the students in this study have basic conceptions about the different vulnerability of people in Germany and Africa, but there seems to be a tendency to emphasize natural hazards and natural conditions. There is a lack in the perception of socio-economic and political dimensions of vulnerability in terms of both sensitivity and adaptive capacity. For instructional settings it is important to take students ideas as a starting point and resource for further learning and to help students recognizing the structure and limits oft their own alternative conceptions

Die Ludwigsburg-Luzerner Bibliographie zur Alltagsvorstellungsforschung in den Geowissenschaften – ein Projekt zur Erfassung der internationalen Forschungsliteratur

This paper is a report about the compilation and structure of the Ludwigsburg-Lucerne bibliography on research about alternative conceptions in geography and the geosciences. The bibliography is of great importance because research on students and teachers conceptual frameworks in geography and the geosciences is attracting more and more attention in geography education. Although the research area concerning alternative conceptions has been flourishing in science education in the last 30 years it has not been very prominent in geography until recently. The bibliography documents publications on conceptual frameworks and conceptual change in the geosciences and is work in progress. It is a valuable source of information that facilitates the accessibility to the relevant research papers. Until March 2008 the authors compiled 317 references concerning empirical investigations and theoretical considerations about students' and teachers' conceptual frameworks and conceptual change as well as research on teaching and learning related to conceptual change in the geosciences. The publications were categorized according to the terminology related to the concept of the nested geosphere (e.g. lithosphere, pedosphere, hydrosphere, atmosphere) and sub-categorized using keywords typical for geoscience phenomena of the distinct spheres. The quantification of the number of references in each geoscience field considered helped to get an overview of what has been achieved so far in conceptual change research in the geosciences and revealed research deficits to be tackled in the future. The bibliography can be downloaded at www.ph-ludwigsburg.de/geographie

Natural Disasters in Geography Education

The impact of students’ conceptions and interests on organisation and effectivity of teaching is undisputable. The following article presents the results of different empirical studies dealing with natural disasters. In 2006, a study on students’ interests was carried out in 6th grade of all school types. The central results - which have not been published so far – are presented on the basis of certain facets, contexts and operation methods of the topic natural disasters. Regarding the aspect “students’ conceptions” the results of selected international studies are described. Here, emphasis is put on two studies from Taiwan and Florida, which consider the meta-level of Weltanschauung in student explanations of natural disasters, and thus differentiate between mythological and scientific approaches concerning students’ conceptions. Didactical-methodological reflections and models on how to deal with natural disasters in geography lessons as well as perspectives on scientific education research complete this article

Correction of endothelial dysfunction in chronic heart failure: additional effects of exercise training and oral L-arginine supplementation

AbstractOBJECTIVESThe aim of this study was to analyze whether L-arginine (L-arg.) has comparable or additive effects to physical exercise regarding endothelium-dependent vasodilation in patients with chronic heart failure (CHF).BACKGROUNDEndothelial dysfunction in patients with CHF can be corrected by both dietary supplementation with L-arg. and regular physical exercise.METHODSForty patients with severe CHF (left ventricular ejection fraction 19 ± 9%) were randomized to an L-arg. group (8 g/day), a training group (T) with daily handgrip training, L-arg. and T (L-arg. + T) or an inactive control group (C). The mean internal radial artery diameter was determined at the beginning and after four weeks in response to brachial arterial administration of acetylcholine (ACh) (7.5, 15, 30 μg/min) and nitroglycerin (0.2 mg/min) with a transcutaneous high-resolution 10 MHz A-mode echo tracking system coupled with a Doppler device. The power of the study to detect clinically significant differences in endothelium-dependent vasodilation was 96.6%.RESULTSAt the beginning, the mean endothelium-dependent vasodilation in response to ACh, 30 μg/min was 2.54 ± 0.09% (p = NS between groups). After four weeks, internal radial artery diameter increased by 8.8 ± 0.9% after ACh 30 μg/min in L-arg. (p < 0.001 vs. C), by 8.6 ± 0.9% in T (p < 0.001 vs. C) and by 12.0 ± 0.3% in L-arg. + T (p < 0.005 vs. C, L-arg. and T). Endothelium-independent vasodilation as assessed by infusion of nitroglycerin was similar in all groups at the beginning and at the end of the study.CONCLUSIONSDietary supplementation of L-arg. as well as regular physical exercise improved agonist-mediated, endothelium-dependent vasodilation to a similar extent. Both interventions together seem to produce additive effects with respect to endothelium-dependent vasodilation

Torus Spectroscopy of the Gross-Neveu-Yukawa Quantum Field Theory: Free Dirac versus Chiral Ising Fixed Point

We establish the universal torus low-energy spectra at the free Dirac fixed point and at the strongly coupled {\em chiral Ising} fixed point and their subtle crossover behaviour in the Gross-Neuveu-Yukawa field theory with ${n_\text{D}=4}$ component Dirac spinors in $D=(2+1)$ dimensions. These fixed points and the field theories are directly relevant for the long-wavelength physics of certain interacting Dirac systems, such as repulsive spinless fermions on the honeycomb lattice or $\pi$-flux square lattice. The torus spectrum has been shown previously to serve as a characteristic fingerprint of relativistic fixed points and is a powerful tool to discriminate quantum critical behaviour in numerical simulations. Here we use a combination of exact diagonalization and quantum Monte Carlo simulations of strongly interacting fermionic lattice models, to compute the critical energy spectrum on finite-size clusters with periodic boundaries and extrapolate them to the thermodynamic limit. Additionally, we compute the torus spectrum analytically using the perturbative expansion in ${\epsilon = 4 - D}$, which is in good agreement with the numerical results, thereby validating the presence of the chiral Ising fixed point in the lattice models at hand. We show that the strong interaction between the spinor field and the scalar order-parameter field strongly influences the critical torus spectrum. Building on these results we are able to address the subtle crossover physics of the low-energy spectrum flowing from the chiral Ising fixed point to the Dirac fixed point, and analyze earlier flawed attempts to extract Fermi velocity renormalizations from the low-energy spectrum.Comment: 24 pages, 14 figure

Rationale and Design of the Leipzig (LIFE) Heart Study: Phenotyping and Cardiovascular Characteristics of Patients with Coronary Artery Disease

We established the Leipzig (LIFE) Heart Study, a biobank and database of patients with different stages of coronary artery disease (CAD) for studies of clinical, metabolic, cellular and genetic factors of cardiovascular diseases.The Leipzig (LIFE) Heart Study (NCT00497887) is an ongoing observational angiographic study including subjects with different entities of CAD. Cohort 1, patients undergoing first-time diagnostic coronary angiography due to suspected stable CAD with previously untreated coronary arteries. Cohort 2, patients with acute myocardial infarction (MI) requiring percutaneous revascularization. Cohort 3, patients with known left main coronary artery disease (LMCAD).We present preliminary results of demographics and phenotyping based on a 4-years analysis of a total of 3,165 subjects. Cohort 1 (n=2,274) shows the typical distribution of elective coronary angiography cohorts with 43% cases with obstructive CAD and 37% normal angiograms. Cohorts 2 and 3 consist of 590 and 301 subjects, respectively, adding patients with severe forms of CAD. The suitability of the database and biobank to perform association studies was confirmed by replication of the CAD susceptibility locus on chromosome 9p21 (OR per allele: 1.55 (any CAD), 1.54 (MI), 1.74 (LMCAD), p<10(-6), respectively). A novel finding was that patients with LMCAD had a stronger association with 9p21 than patients with obstructive CAD without LMCAD (OR 1.22, p=0.042). In contrast, 9p21 did not associate with myocardial infarction in excess of stable CAD.The Leipzig (LIFE) Heart Study provides a basis to identify molecular targets related to atherogenesis and associated metabolic disorders. The study may contribute to an improvement of individual prediction, prevention, and treatment of CAD

Comparison of different methods for post-therapeutic dosimetry in [177Lu]Lu-PSMA-617 radioligand therapy

Background Dosimetry is of high importance for optimization of patient-individual PSMA-targeted radioligand therapy (PSMA-RLT). The aim of our study was to evaluate and compare the feasibility of different approaches of image-based absorbed dose estimation in terms of accuracy and effort in clinical routine. Methods Whole-body planar images and SPECT/CT images were acquired from 24 patients and 65 cycles at 24h, 48h, and ≥96h after administration of a mean activity of 6.4 GBq [177Lu]Lu-PSMA-617 (range 3–10.9 GBq). Dosimetry was performed by use of the following approaches: 2D planar-based dosimetry, 3D SPECT/CT-based dosimetry, and hybrid dosimetry combining 2D and 3D data. Absorbed doses were calculated according to IDAC 2.1 for the kidneys, the liver, the salivary glands, and bone metastases. Results Mean absorbed doses estimated by 3D dosimetry (the reference method) were 0.54 ± 0.28 Gy/GBq for the kidneys, 0.10 ± 0.05 Gy/GBq for the liver, 0.81 ± 0.34 Gy/GBq for the parotid gland, 0.72 ± 0.39 Gy/GBq for the submandibular gland, and 1.68 ± 1.32 Gy/GBq for bone metastases. Absorbed doses of normal organs estimated by hybrid dosimetry showed small, non-significant differences (median up to 4.0%) to the results of 3D dosimetry. Using 2D dosimetry, in contrast, significant differences (median up to 10.9%) were observed. Regarding bone metastases, small, but significant differences (median up to 7.0%) of absorbed dose were found for both, 2D dosimetry and hybrid dosimetry. Bland-Altman analysis revealed high agreement between hybrid dosimetry and 3D dosimetry for normal organs and bone metastases, but substantial differences between 2D dosimetry and 3D dosimetry. Conclusion Hybrid dosimetry provides high accuracy in estimation of absorbed dose in comparison to 3D dosimetry for all important organs and is therefore feasible for use in individualized PSMA-RLT

Detection efficacy of [89Zr]Zr-PSMA-617 PET/CT in [68Ga]Ga-PSMA-11 PET/CT-negative biochemical recurrence of prostate cancer

Rationale In patients with biochemical recurrence of prostate cancer (BCR), preliminary data suggest that prostate-specifc membrane antigen (PSMA) ligand radiotracers labeled with zirconium-89 (89Zr; half-life ~ 78.41 h), which allow imaging≥24 h post-injection, detect suspicious lesions that are missed when using tracers incorporating short-lived radionuclides. Materials and methods To confrm [ 89Zr]Zr-PSMA-617 positron emission tomography/computed tomography (PET/CT) detection efcacy regarding such lesions, and compare quality of 1-h, 24-h, and 48-h [ 89Zr]Zr-PSMA-617 scans, we retrospectively analyzed visual fndings and PET variables refecting lesional [ 89Zr]Zr-PSMA-617 uptake and lesion-to-background ratio. The cohort comprised 23 men with BCR post-prostatectomy, median (minimum–maximum) prostate-specifc antigen (PSA) 0.54 (0.11–2.50) ng/mL, and negative [ 68Ga]Ga-PSMA-11 scans 40±28 d earlier. Primary endpoints were percentages of patients with, and classifcations of, suspicious lesions. Results Altogether, 18/23 patients (78%) had 36 suspicious lesions (minimum–maximum per patient: 1–4) on both 24-h and 48-h scans (n=33 lesions) or only 48-h scans (n=3 lesions). Only one lesion appeared on a 1-h scan. Lesions putatively represented local recurrence in 11 cases, and nodal or bone metastasis in 21 or 4 cases, respectively; 1/1 lesion was histologically confrmed as a nodal metastasis. In all 15 patients given radiotherapy based on [ 89Zr]Zr-PSMA-617 PET/CT, PSA values decreased after this treatment. Comparison of PET variables in 24-h vs 48-h scans suggested no clear superiority of either regarding radiotracer uptake, but improved lesion-to-background ratio at 48 h. Conclusions In men with BCR and low PSA, [ 89Zr]Zr-PSMA-617 PET/CT seems efective in fnding prostate malignancy not seen on [ 68Ga]Ga-PSMA-11 PET/CT. The higher detection rates and lesion-to-background ratios of 48-h scans versus 24-h scans suggest that imaging at the later time may be preferable. Prospective study of [ 89Zr]Zr-PSMA-617 PET/CT is warranted

Gemcitabine and Docetaxel for Epithelioid Sarcoma: Results from a Retrospective, Multi-Institutional Analysis

Objective: Epithelioid sarcoma (ES) presents unique clinical features in comparison to other sarcoma subtypes. Data regarding the benefits of chemotherapy are very limited. Combination regimens using gemcitabine and docetaxel (Gem/Doce) have proven to be effective, especially in uterine and nonuterine leiomyosarcoma. Yet, there is no available data on the efficacy of Gem/Doce in ES. Methods: A retrospective analysis of the three participating institutions was performed. Twenty-eight patients with an ES diagnosis presented at one of the participating institutions between 1989 and 2012. Of this group, 17 patients received chemotherapy. Results: Patients' median overall survival (OS) after the beginning of palliative chemotherapy was 21 months, and the 1-year OS was 87%. Twelve patients received Gem/Doce with a clinical benefit rate of 83%. The median progression-free survival (PFS) was 8 months for all patients receiving Gem/Doce. The best response was complete remission in 1 patient and partial remission in 6 patients. All 6 patients receiving Gem/Doce as a first-line treatment showed measurable responses with a median PFS of 9 months. Conclusions: In this retrospective study, Gem/Doce was an effective chemotherapeutic regimen for ES. Prospective studies are needed to better assess the effects of this combination drug therapy