Lösungsstrategien im Physikunterricht

Eine der wichtigsten zu erlernenden Kompetenzen und gleichzeitig auch Ziel des Physikunterrichts ist das Lösen von realen, physikalischen Problemstellungen. Oftmals wird die Strategie zum Lösen des Problems eher unbewusst erlernt und angewandt, so dass die Lernenden die Problemstellungen meist intuitiv lösen. Zur Steigerung der Problemlösefähigkeit sollten diese jedoch bewusst angeeignet werden. Aus pragmatischer und neurowissenschaftlicher Sicht werden Denk- und Handlungsmuster betrachtet. Des Weiteren werden die grundlegenden Heuristiken (d.h. die Kunst des Problemlösens) in den fächerübergreifenden Strategien, den fachspezifischen Prinzipien und den situationsspezifischen Hilfsmitteln vorgestellt. Wir schildern unsere Erfahrungen aus dem Unterricht und stellen die Ergebnisse eines Modultages vor

Lösungsstrategien im Physikunterricht

Eine der wichtigsten zu erlernenden Kompetenzen und gleichzeitig auch Ziel des Physikunterrichts ist das Lösen von realen, physikalischen Problemstellungen. Oftmals wird die Strategie zum Lösen des Problems eher unbewusst erlernt und angewandt, so dass die Lernenden die Problemstellungen meist intuitiv lösen. Zur Steigerung der Problemlösefähigkeit sollten diese jedoch bewusst angeeignet werden. Aus pragmatischer und neurowissenschaftlicher Sicht werden Denk- und Handlungsmuster betrachtet. Des Weiteren werden die grundlegenden Heuristiken (d.h. die Kunst des Problemlösens) in den fächerübergreifenden Strategien, den fachspezifischen Prinzipien und den situationsspezifischen Hilfsmitteln vorgestellt. Wir schildern unsere Erfahrungen aus dem Unterricht und stellen die Ergebnisse eines Modultages vor

A nucleosome assembly protein-like polypeptide binds to chloroplast group II intron RNA in Chlamydomonas reinhardtii

In the unicellular green alga Chlamydomonas reinhardtii, the chloroplast-encoded tscA RNA is part of a tripartite group IIB intron, which is involved in trans-splicing of precursor mRNAs. We have used the yeast three-hybrid system to identify chloroplast group II intron RNA-binding proteins, capable of interacting with the tscA RNA. Of 14 candidate cDNAs, 13 encode identical polypeptides with significant homology to members of the nuclear nucleosome assembly protein (NAP) family. The RNA-binding property of the identified polypeptide was demonstrated by electrophoretic mobility shift assays using different domains of the tripartite group II intron as well as further chloroplast transcripts. Because of its binding to chloroplast RNA it was designated as NAP-like (cNAPL). In silico analysis revealed that the derived polypeptide carries a 46 amino acid chloroplast leader peptide, in contrast to nuclear NAPs. The chloroplast localization of cNAPL was demonstrated by laser scanning confocal fluorescence microscopy using different chimeric cGFP fusion proteins. Phylogenetic analysis shows that no homologues of cNAPL and its related nuclear counterparts are present in prokaryotic genomes. These data indicate that the chloroplast protein described here is a novel member of the NAP family and most probably has not been acquired from a prokaryotic endosymbiont

A nucleosome assembly protein-like polypeptide binds to chloroplast group II intron RNA in Chlamydomonas reinhardtii

In the unicellular green alga Chlamydomonas reinhardtii, the chloroplast-encoded tscA RNA is part of a tripartite group IIB intron, which is involved in trans-splicing of precursor mRNAs. We have used the yeast three-hybrid system to identify chloroplast group II intron RNA-binding proteins, capable of interacting with the tscA RNA. Of 14 candidate cDNAs, 13 encode identical polypeptides with significant homology to members of the nuclear nucleosome assembly protein (NAP) family. The RNA-binding property of the identified polypeptide was demonstrated by electrophoretic mobility shift assays using different domains of the tripartite group II intron as well as further chloroplast transcripts. Because of its binding to chloroplast RNA it was designated as NAP-like (cNAPL). In silico analysis revealed that the derived polypeptide carries a 46 amino acid chloroplast leader peptide, in contrast to nuclear NAPs. The chloroplast localization of cNAPL was demonstrated by laser scanning confocal fluorescence microscopy using different chimeric cGFP fusion proteins. Phylogenetic analysis shows that no homologues of cNAPL and its related nuclear counterparts are present in prokaryotic genomes. These data indicate that the chloroplast protein described here is a novel member of the NAP family and most probably has not been acquired from a prokaryotic endosymbiont

Alternative Oxidase Dependent Respiration Leads to an Increased Mitochondrial Content in Two Long-Lived Mutants of the Ageing Model Podospora anserina

The retrograde response constitutes an important signalling pathway from mitochondria to the nucleus which induces several genes to allow compensation of mitochondrial impairments. In the filamentous ascomycete Podospora anserina, an example for such a response is the induction of a nuclear-encoded and iron-dependent alternative oxidase (AOX) occurring when cytochrome-c oxidase (COX) dependent respiration is affected. Several long-lived mutants are known which predominantly or exclusively respire via AOX. Here we show that two AOX-utilising mutants, grisea and PaCox17::ble, are able to compensate partially for lowered OXPHOS efficiency resulting from AOX-dependent respiration by increasing mitochondrial content. At the physiological level this is demonstrated by an elevated oxygen consumption and increased heat production. However, in the two mutants, ATP levels do not reach WT levels. Interestingly, mutant PaCox17::ble is characterized by a highly increased release of the reactive oxygen species (ROS) hydrogen peroxide. Both grisea and PaCox17::ble contain elevated levels of mitochondrial proteins involved in quality control, i. e. LON protease and the molecular chaperone HSP60. Taken together, our work demonstrates that AOX-dependent respiration in two mutants of the ageing model P. anserina is linked to a novel mechanism involved in the retrograde response pathway, mitochondrial biogenesis, which might also play an important role for cellular maintenance in other organisms

Chlamydomonas reinhardtii

binds to chloroplast group II intron RNA i

Low-dose, non-supervised, health insurance initiated exercise for the treatment and prevention of chronic low back pain in employees. Results from a randomized controlled trial

<div><p>Objective</p><p>Back pain is a major problem requiring pragmatic interventions, low in costs for health care providers and feasible for individuals to perform. Our objective was to test the effectiveness of a low-dose 5-month exercise intervention with small personnel investment on low back strength and self-perceived pain.</p><p>Methods</p><p>Two hundred twenty-six employees (age: 42.7±10.2 years) from three mid-size companies were randomized to 5-month non-supervised training at home (3 times/week for 20 minutes) or wait-list-control. Health insurance professionals instructed the participants on trunk exercises at the start and then supervised participants once a month.</p><p>Results</p><p>Muscle strength for back extension increased after the 5-month intervention with a significant between-group difference (mean 27.4 Newton [95%CI 2.2; 60.3]) favoring the exercise group (p = 0.035). Low back pain was reduced more in subjects after exercise than control (mean difference –0.74 cm [95%CI –1.17; –0.27], p = 0.002). No between-group differences were observed for back pain related disability and work ability. After stratified analysis only subjects with preexisting chronic low back pain showed a between-group difference (exercise versus controls) after the intervention in their strength for back extension (mean 55.7 Newton [95%CI 2.8; 108.5], p = 0.039), self-perceived pain (mean –1.42 cm [95%CI –2.32; –0.51], p = 0.003) and work ability (mean 2.1 points [95%CI 0.2; 4.0], p = 0.032). Significant between-group differences were not observed in subjects without low back pain: strength for back extension (mean 23.4 Newton [95%CI –11.2; 58.1], p = 0.184), self-perceived pain (mean –0.48 cm [95%CI –0.99; 0.04], p = 0.067) and work ability (mean –0.1 points [95%CI –0.9; 0.9], p = 0.999). An interaction between low back pain subgroups and the study intervention (exercise versus control) was exclusively observed for the work ability index (p = 0.016).</p><p>Conclusion</p><p>In middle-aged employees a low-dose, non-supervised exercise program implemented over 20 weeks improved trunk muscle strength and low back pain, and in those with preexisting chronic low back pain improved work ability.</p></div

Changes from baseline for each study group and mean differences between groups for primary and key secondary outcomes.

<p>Changes from baseline for each study group and mean differences between groups for primary and key secondary outcomes.</p

Effects of 5 months of exercise for subjects with or without pre-existing chronic low back pain.

<p>Maximum force for isometric low back extension (left panel), low back pain as assessed with a 10 cm visual analog scale (VAS, middle panel), and the work ability index (total score) from the work ability questionnaire (right panel) before and after 5 months exercise or control. Subjects are stratified for the presence of chronic low back pain at baseline, defined as having experienced low back pain almost every day for a minimum of three months per year. Data are mean ± SE. The framed p-values are given for between-group differences (exercise- versus control group) over time as analyzed with an ANCOVA model. * indicates p<0.05 for the interaction (subgroup [chronic LBP or no chronic LBP] x intervention [exercise or control]) included as covariate in the primary analysis model.</p

Baseline data and differences between groups over time for subjects with and without chronic low.

<p>Baseline data and differences between groups over time for subjects with and without chronic low.</p