26 research outputs found
Specific teacher self-efficacy in teacher students. An integration of two measurement instruments
Die Lehrkraft-Selbstwirksamkeitserwartung (SWE) im Studium kann die spätere Berufstätigkeit von Lehrkräften langfristig positiv beeinflussen. Im deutschen Sprachraum fehlen Instrumente, die die Lehrkraft-SWE mit spezifischen Subskalen zu einem frühen Zeitpunkt im Studium messen. Vorgestellt wird eine adaptierte Skala basierend auf der Fragestruktur der Skala Lehrerselbstwirksamkeit (WirkLehr; Schmitz & Schwarzer, 2000) sowie den Inhalten der Teachers\u27 Sense of Efficacy Scale (TSES; Tschannen-Moran & Woolfolk Hoy, 2001) mit den Subskalen Engagement, Instruktionen und Classroom-Management. Die psychometrischen Kennwerte der adaptierten Skala wurden mittels konfirmatorischer Faktorenanalyse anhand von N = 618 Studierenden (drittes Semester) überprüft. Es zeigte sich ein besserer Modellfit für ein Drei-Faktoren- gegenüber einem Ein- Faktor-Modell. Bezüglich der drei Subskalen ergaben sich positive Korrelationen mit WirkLehr, negative Korrelationen mit dem Stresserleben (Perceived Stress Scale; Büssing, 2011) sowie positive Korrelationen mit einer zweiten Messung einen Monat später. Zusätzlich wurde die adaptierte Skala im Rahmen einer Classroom-Management-Trainingsevaluation eingesetzt. Hier zeigte sich eine höhere Lehrkraft-SWE einer Trainings- gegenüber einer Kontrollgruppe für die Bereiche Classroom- Management und Instruktionen. Aufgrund der zufriedenstellenden Validitäts- und Reliabilitätsbelege kann die adaptierte Skala zur Messung der spezifischen Lehrkraft-SWE bei Studierenden eingesetzt werden. (DIPF/Orig.)Students\u27 self-efficacy can have a long-term beneficial influence on their later teaching profession. However, there is a lack of German instruments that consider specific aspects of teacher self-efficacy at an early stage of teacher training. An adapted teacher self-efficacy scale is presented based on the scale Lehrerselbstwirksamkeit (WirkLehr; Schmitz & Schwarzer, 2000) and on the Teachers\u27 Sense of Efficacy Scale (TSES; Tschannen-Moran & Woolfolk Hoy, 2001) with the subscales engagement, instruction, and classroom management. Confirmatory factor analysis (N = 618 students, third semester) indicated a better model fit for a three-factor-model compared to a singlefactor-model. Investigations revealed positive correlations of the three subscales with teacher self efficacy (WirkLehr), negative correlations with stress (Perceived Stress Scale, PSS; Büssing, 2011), and positive correlations of the subscales with their second measurements one month later. The adapted scale was also implemented in a classroom management training evaluation; the training group showed higher self-efficacy in classroom management and instructions than the control group. Given the evidence of satisfactory validity and reliability, the adapted scale can be used to assess specific teacher self-efficacy in teacher students. (DIPF/Orig.
Trainer/in für Classroom-Management werden – Ein Schulungskonzept
Im Rahmen der Lehramtsausbildung werden an der TU Braunschweig zur Vorbereitung auf
das sechswöchige Allgemeine Schulpraktikum (ASP) Classroom-Management-Trainings für
Lehramtsstudierende durchgefĂĽhrt. Damit perspektivisch alle Lehramtsstudierenden an
diesen Trainings teilnehmen können, ist es notwendig, entsprechend viele Trainerinnen und
Trainer durch eine Schulung zur Durchführung dieses Trainings zu befähigen. Vorgestellt
werden in diesem Beitrag zunächst die strukturelle Ausgangssituation, das Konzept des
Classroom-Management-Trainings, die Kompetenzen, welche Classroom-Management-
Trainerinnen und -Trainer benötigen sowie das Konzept der Schulung und Möglichkeiten
der Evaluation und Qualitätssicherung
Training zur Förderung von Classroom-Management-Kompetenzen bei Lehramtsstudierenden: 2. Evaluationsstudie
Im Zentrum steht die Evaluation des Braunschweiger Classroom-Management-Trainings
(CM-Training), insbesondere Trainingseffekte auf Wissen, Kompetenzen und die Einsicht in
die Notwendigkeit von Selbstreflexion. In einem randomisierten Prä-Post-Design absolvierten
133 Lehramtsstudierende ein CM-Training (Interventionsgruppe, TG); 234 nahmen zu
einem späteren Zeitpunkt an einer alternativen CM-Veranstaltung teil (Wartekontrollgruppe,
KG). Die Teilnehmenden der TG berichteten zur Post-Messung höheres Wissen und
höhere Kompetenzen im CM als Teilnehmende der KG. Die Befunde bekräftigen damit die
Ergebnisse, die im Rahmen einer ersten Evaluationsstudie zum CM-Training berichtet wurden
(Hannemann, Uhde & Thies, eingereicht). Teilnehmende der TG berichteten nach dem
Training eine höhere Notwendigkeit an Selbstreflexion. Die Werte der Selbstreflexionsskalen
Einsicht und Engagement sowie die internale Kontrollüberzeugung blieben unverändert,
während sich diese in der KG signifikant verschlechterten. Hinsichtlich der Ergebnisse
in einem CM-Wissenstest unterschieden sich die Gruppen nicht signifikant im Zuwachs. ZukĂĽnftig
ist die Nachhaltigkeit der Effekte sowie das Gelingen des Transfers in die Schulpraxis
zu untersuchen
Asymmetric and symmetric dimethylarginine in high altitude pulmonary hypertension (HAPH) and high altitude pulmonary edema (HAPE)
Introduction: High altitude exposure may lead to high altitude pulmonary hypertension (HAPH) and high altitude pulmonary edema (HAPE). The pathophysiologic processes of both entities have been linked to decreased nitric oxide (NO) availability.Methods: We studied the effect of acute high altitude exposure on the plasma concentrations of asymmetric (ADMA) and symmetric dimethylarginine (SDMA), L-arginine, L-ornithine, and L-citrulline in two independent studies. We further investigated whether these biomarkers involved in NO metabolism were related to HAPH and HAPE, respectively. Fifty (study A) and thirteen (study B) non-acclimatized lowlanders were exposed to 4,559Â m for 44 and 67Â h, respectively. In contrast to study A, the participants in study B were characterized by a history of at least one episode of HAPE. Arterial blood gases and biomarker concentrations in venous plasma were assessed at low altitude (baseline) and repeatedly at high altitude. HAPE was diagnosed by chest radiography, and HAPH by measuring right ventricular to atrial pressure gradient (RVPG) with transthoracic echocardiography. AMS was evaluated with the Lake Louise Score (LLS) and the AMS-C score.Results: In both studies SDMA concentration significantly increased at high altitude. ADMA baseline concentrations were higher in individuals with HAPE susceptibility (study B) compared to those without (study A). However, upon high altitude exposure ADMA only increased in individuals without HAPE susceptibility, while there was no further increase in those with HAPE susceptibility. We observed an acute and transient decrease of L-ornithine and a more delayed but prolonged reduction of L-citrulline during high altitude exposure. In both studies SDMA positively correlated and L-ornithine negatively correlated with RVPG. ADMA was significantly associated with the occurrence of HAPE (study B). ADMA and SDMA were inversely correlated with alveolar PO2, while L-ornithine was inversely correlated with blood oxygenation and haemoglobin levels, respectively.Discussion: In non-acclimatized individuals ADMA and SDMA, two biomarkers decreasing endothelial NO production, increased after acute exposure to 4,559Â m. The observed biomarker changes suggest that both NO synthesis and arginase pathways are involved in the pathophysiology of HAPH and HAPE
The Effect of Obstructive Sleep Apnea and Continuous Positive Airway Pressure Therapy on Skeletal Muscle Lipid Content in Obese and Nonobese Men.
Obstructive sleep apnea (OSA), independently of obesity (OBS), predisposes to insulin resistance (IR) for largely unknown reasons. Because OSA-related intermittent hypoxia triggers lipolysis, overnight increases in circulating free fatty acids (FFAs) including palmitic acid (PA) may lead to ectopic intramuscular lipid accumulation potentially contributing to IR. Using 3-T-1H-magnetic resonance spectroscopy, we therefore compared intramyocellular and extramyocellular lipid (IMCL and EMCL) in the vastus lateralis muscle at approximately 7 am between 26 male patients with moderate-to-severe OSA (17 obese, 9 nonobese) and 23 healthy male controls (12 obese, 11 nonobese). Fiber type composition was evaluated by muscle biopsies. Moreover, we measured fasted FFAs including PA, glycated hemoglobin A1c, thigh subcutaneous fat volume (ScFAT, 1.5-T magnetic resonance tomography), and maximal oxygen uptake (VO2max). Fourteen patients were reassessed after continuous positive airway pressure (CPAP) therapy. Total FFAs and PA were significantly (by 178% and 166%) higher in OSA patients vs controls and correlated with the apnea-hypopnea index (AHI) (r ≥ 0.45, P < .01). Moreover, IMCL and EMCL were 55% (P < .05) and 40% (P < .05) higher in OSA patients, that is, 114% and 103% in nonobese, 24.4% and 8.4% in obese participants (with higher control levels). Overall, PA, FFAs (minus PA), and ScFAT significantly contributed to IMCL (multiple r = 0.568, P = .002). CPAP significantly decreased EMCL (-26%) and, by trend only, IMCL, total FFAs, and PA. Muscle fiber composition was unaffected by OSA or CPAP. Increases in IMCL and EMCL are detectable at approximately 7 am in OSA patients and are partly attributable to overnight FFA excesses and high ScFAT or body mass index. CPAP decreases FFAs and IMCL by trend but significantly reduces EMCL
Association of Genes of the NO Pathway with Altitude Disease and Hypoxic Pulmonary Hypertension
Chronic intermittent hypoxia leads to high-altitude pulmonary hypertension, which is associated with high asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide synthesis. Therefore, we aimed to understand the relation of single nucleotide polymorphisms in this pathway to high-altitude pulmonary hypertension (HAPH). We genotyped 69 healthy male Chileans subjected to chronic intermittent hypoxia. Acclimatization to altitude was determined using the Lake Louise Score and the presence of acute mountain sickness. Echocardiography was performed after six months in 24 individuals to estimate pulmonary arterial pressure. The minor allele of dimethylarginine dimethylaminohydrolase (DDAH)1 rs233112 was associated with high-baseline plasma ADMA concentration, while individuals homozygous for the major allele of DDAH2 rs805304 had a significantly greater increase in ADMA during chronic intermittent hypoxia. The major allele of alanine glyoxylate aminotransferase-2 (AGXT2) rs37369 was associated with a greater reduction of plasma symmetric dimethylarginine (SDMA). Several genes were associated with high-altitude pulmonary hypertension, and the nitric oxide synthase (NOS)3 and DDAH2 genes were related to acute mountain sickness. In conclusion, DDAH1 determines baseline plasma ADMA, while DDAH2 modulates ADMA increase in hypoxia. AGXT2 may be up-regulated in hypoxia. Genomic variation in the dimethylarginine pathway affects the development of HAPH and altitude acclimatization
TBC-8, a Putative RAB-2 GAP, Regulates Dense Core Vesicle Maturation in <em>Caenorhabditis elegans</em>
<div><p>Dense core vesicles (DCVs) are thought to be generated at the late Golgi apparatus as immature DCVs, which subsequently undergo a maturation process through clathrin-mediated membrane remodeling events. This maturation process is required for efficient processing of neuropeptides within DCVs and for removal of factors that would otherwise interfere with DCV release. Previously, we have shown that the GTPase, RAB-2, and its effector, RIC-19, are involved in DCV maturation in <em>Caenorhabditis elegans</em> motoneurons. In <em>rab-2</em> mutants, specific cargo is lost from maturing DCVs and missorted into the endosomal/lysosomal degradation route. Cargo loss could be prevented by blocking endosomal delivery. This suggests that RAB-2 is involved in retention of DCV components during the sorting process at the Golgi-endosomal interface. To understand how RAB-2 activity is regulated at the Golgi, we screened for RAB-2–specific GTPase activating proteins (GAPs). We identified a potential RAB-2 GAP, TBC-8, which is exclusively expressed in neurons and which, when depleted, shows similar DCV maturation defects as <em>rab-2</em> mutants. We could demonstrate that RAB-2 binds to its putative GAP, TBC-8. Interestingly, TBC-8 also binds to the RAB-2 effector, RIC-19. This interaction appears to be conserved as TBC-8 also interacted with the human ortholog of RIC-19, ICA69. Therefore, we propose that a dynamic ON/OFF cycling of RAB-2 at the Golgi induced by the GAP/effector complex is required for proper DCV maturation.</p> </div
TBC-8 is a putative RAB-2 GAP.
<p>(A) TBC-8 contains two predicted domains: an N-terminal RUN domain (96 to 230 aa) (blue) and a C-terminal TBC-domain (621 to 862 aa) (purple). Mutation of the catalytically active arginine (R697) to alanine within the TBC-domain is indicated. Please see <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1002722#pgen.1002722.s004" target="_blank">Figure S4</a> for full protein sequence. (B) Alignment of the catalytic motif of TBC-8 and its orthologs in humans (SGSM1) and in <i>Drosophila melanogaster</i> (CG32506-PC) are shown. The arrow indicates the catalytic arginine residue necessary for GAP activity. (C) In a yeast two-hybrid assay, all <i>C. elegans</i> Rabs in their constitutively GTP-bound form were tested against wild type TBC-8 (upper panel) and a catalytically inactive form of TBC-8 (R697A) (lower panel), respectively. Strikingly, RAB-2 (Q65L) interacted with TBC-8 (R697A) but not with wild type TBC-8, suggesting that TBC-8 is the GAP for RAB-2. Unlike RAB-2, RAB-19 (Q69L) interacted weakly with both forms of TBC-8. (D) Interactions of RAB-2 and RAB-19 with TBC-8 occurred in a GTP-dependent manner. Constitutively active RAB-2 (Q65L) and RAB-19 (Q69L) interacted with TBC-8 whereas their dominant inactive forms [RAB-2 (S20N), RAB-19 (T24N)] did not. The closest paralog of RAB-2, RAB-14, did not show interaction with TBC-8 wild type or R697A in a yeast two-hybrid analysis. AD: Gal4p DNA activation domain fusion, BD: Gal4p DNA binding domain fusion, His: histidine, RAB<sub>GTP</sub>: constitutively GTP-bound RAB GTPase, “–”: empty vector pGADT7 was used for testing self-activation.</p
The RAB-2 effector, RIC-19/ICA69, interacts with TBC-8.
<p>(A) RIC-19-YFP is recruited to membranes in <i>tbc-8(tm3802)</i> mutants whereas it remained predominantly cytosolic in wild type neurons. Scale bar represents 3 µm. (B) NLP-21-derived VENUS analysis of the single mutants <i>ric-19(ok833), tbc-8(tm3802)</i> and the double mutant of both revealed that RIC-19 and TBC-8 are involved in the same genetic pathway. Scale bar represents 5 µm. Error bars = s.e.m. (***, P<0.0001; **, P<0.001, Student's t-test) (C) tagRFP-TBC-8 is able to recruit RIC-19-YFP to membranes resulting in a full co-localization in neurons. Scale bar represents 3 µm. This recruitment is also seen in an <i>unc-108/rab-2(nu415)</i> null mutant background. (D) Schematic representation of TBC-8 constructs (full-length and RUN domain (1–597 aa)) used for yeast two-hybrid analysis (Y2H) (E) and co-immunoprecipitation (co-IP) (F). (E) Y2H: RIC-19 and its human ortholog, ICA69, interacted with full length TBC-8 and TBC-8 RUN domain (1–597 aa) suggesting conservation of this interaction. (F) Co-IP: HEK293 cells were co-transfected with constructs expressing GFP-tagged RIC-19 (or GFP alone as control) and V5-TBC-8 (full length or RUN domain (1–597 aa)). An anti-GFP antibody was used to precipitate GFP-RIC-19 or GFP as control. Interactions between TBC-8 (full length and the RUN domain) with RIC-19 were visualized on Western blots. AD: Gal4p DNA activation domain fusion, BD: Gal4p DNA binding domain fusion, His: histidine, IN: Input, IP: immunoprecipitation, “– ”: empty vector pGADT7 was used for testing self-activation.</p
SV and DCV analysis determined by HPF EM.
<p>Only significant differences of mutant strains compared to wild type worms are indicated. Mean ± s.e.m. are shown (**, P<0.001; Student's t-test). The mean diameter of DCVs in <i>unc-108(n501)</i> mutants was more viable, which was shown previously <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1002722#pgen.1002722-Sumakovic1" target="_blank">[22]</a>.</p