Chronic Progressive External Ophthalmoplegia Is Associated with a Novel Mutation in the Mitochondrial tRNA(Asn) Gene

Chronic progressive external ophthalmoplegia (CPEO) is caused by a decreased oxidative phosphorylation (OXPHOS) activity due to large-scale deletions of the mitochondrial genome in 50 % of the patients. The deletions encompass structural OXPHOS genes as well as tRNA genes, required for their expression so that the pathogenesis could be due to the deleted OXPHOS subunits or to an impaired mitochondrial translation. We have analyzed the mitochondrial genome of a patient presenting with CPEO for single base substitutions and discovered a novel heteroplasmic mutation in the tRNAAsn gene at position 5692 that converts a highly conserved adenine into a guanine. This mutation is unique because it is located at the transition of the anticodon loop to the anticodon stem and it leads to an additional base pair, thus reducing the number of loop-forming nucleotides from seven to five. Our findings suggest that CPEO can be caused by a single base substition in a mitochondrial tRNA gene so that the mitochondrial protein synthesis becomes the rate limiting step in OXPHOS fidelity

Effects of a multi-component exercise program and calcium–vitamin-D3-fortified milk on bone mineral density in older men : a randomised controlled trial

Summary We examined the independent and combined effects of a multi-component exercise program and calcium&ndash;vitamin-D3-fortified milk on bone mineral density (BMD) in older men. Exercise resulted in a 1.8% net gain in femoral neck BMD, but additional calcium&ndash;vitamin D3 did not enhance the response in this group of older well-nourished men.Introduction This 12-month randomised controlled trial assessed whether calcium&ndash;vitamin-D3-fortified milk could enhance the effects of a multi-component exercise program on BMD in older men.Methods Men (n&thinsp; =&thinsp;180) aged 50&ndash;79 years were randomised into: (1) exercise + fortified milk; (2) exercise; (3) fortified milk; or (4) controls. Exercise consisted of high intensity progressive resistance training with weight-bearing impact exercise. Men assigned to fortified milk consumed 400 mL/day of low fat milk providing an additional 1,000 mg/day calcium and 800 IU/day vitamin D3. Femoral neck (FN), total hip, lumbar spine and trochanter BMD and body composition (DXA), muscle strength 25-hydroxyvitamin D and parathyroid hormone (PTH) were assessed.Results There were no exercise-by-fortified milk interactions at any skeletal site. Exercise resulted in a 1.8% net gain in FN BMD relative to no-exercise (p&thinsp;&lt;&thinsp;0.001); lean mass (0.6 kg, p&thinsp;&lt;&thinsp;0.05) and muscle strength (20&ndash;52%, p&thinsp;&lt;&thinsp;0.001) also increased in response to exercise. For lumbar spine BMD, there was a net 1.4&ndash;1.5% increase in all treatment groups relative to controls (all p&thinsp;&lt;&thinsp;0.01). There were no main effects of fortified milk at any skeletal site.Conclusion A multi-component community-based exercise program was effective for increasing FN BMD in older men, but additional calcium&ndash;vitamin D3 did not enhance the osteogenic response.<br /

Rapid mapping of visual receptive fields by filtered back-projection: application to multi-neuronal electrophysiology and imaging

Neurons in the visual system vary widely in the spatiotemporal properties of their receptive fields (RFs), and understanding these variations is key to elucidating how visual information is processed. We present a new approach for mapping RFs based on the filtered back projection (FBP), an algorithm used for tomographic reconstructions. To estimate RFs, a series of bars were flashed across the retina at pseudo‐random positions and at a minimum of five orientations. We apply this method to retinal neurons and show that it can accurately recover the spatial RF and impulse response of ganglion cells recorded on a multi‐electrode array. We also demonstrate its utility for in vivo imaging by mapping the RFs of an array of bipolar cell synapses expressing a genetically encoded Ca2+ indicator. We find that FBP offers several advantages over the commonly used spike‐triggered average (STA): (i) ON and OFF components of a RF can be separated; (ii) the impulse response can be reconstructed at sample rates of 125 Hz, rather than the refresh rate of a monitor; (iii) FBP reveals the response properties of neurons that are not evident using STA, including those that display orientation selectivity, or fire at low mean spike rates; and (iv) the FBP method is fast, allowing the RFs of all the bipolar cell synaptic terminals in a field of view to be reconstructed in under 4 min. Use of the FBP will benefit investigations of the visual system that employ electrophysiology or optical reporters to measure activity across populations of neurons

Cognitive Rehearsal Training for Upskilling Undergraduate Nursing Students Against Bullying: A Qualitative Pilot Study

The purpose of this qualitative study is to examine the effectiveness of an anti-bullying intervention called Cognitive Rehearsal Training (CRT) using a workshop format to increase third year nursing students’ knowledge and confidence to address bullying behaviour. A lanyard card identifying ten common bullying behaviours and possible phrases to stand up to bullying was used as a tool to Stop! Reflect! and Respond! as a process to resolve conflict (Griffin, 2004; Griffin & Clark, 2014). Although similar bullying interventions have been studied among practicing nurses, few studies exist that involve students within their pre-licensure training program (Iheduru-Anderson, 2014; Thomas, 2010) and none in Canada. Fifty eight third year undergraduate nursing students in two classrooms took part in an anti-bullying workshop introducing the use of CRT as a tool to address bullying behaviour, and provided feedback regarding the utility of the CRT tool. One significant theme was that confidence and competence are inextricably linked, and lack of confidence to address conflict was reported to result in absenteeism, depression, thoughts of quitting school, and withdrawal from school-related responsibilities. Another key theme was that faculty profoundly impact the outcomes of bullying; students expect faculty to be knowledgeable about bullying and to have the skills to mediate conflict. A third theme was that power is an integral element in bullying dynamics, and participants commonly described feelings of vulnerability, powerlessness, and a reluctance to respond assertively to conflict, and the belief that catastrophic things would happen if they did. The findings of the study support the use of the CRT tool and its integration into undergraduate nursing curricula. Résumé Le but de cette étude qualitative est d’explorer l’efficacité d’une intervention pour lutter contre l’intimidation, nommée l’entraînement par répétition cognitive (ERC). Le format d’atelier a été utilisé pour augmenter les connaissances et renforcer la confiance d’étudiantes de troisième année en sciences infirmières pour faire face aux comportements d’intimidation. Une cocarde portée autour du cou et identifiant dix comportements fréquents d’intimidation ainsi que des phrases possibles pour contrer l’intimidation a été utilisée comme outil pour Arrêter! Réfléchir! et Répondre! comme processus de résolution de conflit (Griffin, 2004; Griffin & Clark, 2014). Bien que des interventions similaires portant sur l’intimidation ont fait l’objet d’études chez des infirmières ayant obtenu leur permis d’exercice, peu d’études existent concernant les étudiantes au cours de leur programme de formation (Iheduru-Anderson, 2014; Thomas, 2010), et aucune étude n’a été réalisée au Canada. Cinquante-huit étudiantes de troisième année au premier cycle universitaire ont pris part en deux groupes classes à un atelier visant à contrer l’intimidation. L’ERC a été présenté comme outil pour faire face aux comportements d’intimidation et les étudiantes ont fourni leurs commentaires concernant l’utilité de l’outil d’ERC. Un thème central des résultats est à l’effet que la confiance et la compétence sont inextricablement liées. Il y est rapporté que le manque de confiance chez les étudiantes pour faire face à un conflit entraîne l\u27absentéisme, la dépression, des pensées quant à l\u27abandon des études et le retrait de leurs responsabilités liées au programme d’études. Un deuxième thème principal porte sur l’impact considérable du corps professoral sur les résultats de l’intimidation. Les étudiantes s’attendent à ce que les membres du corps professoral soient bien informés à propos de l’intimidation et qu’ils détiennent les habiletés nécessaires pour agir comme médiateur. Un troisième thème porte sur le pouvoir comme un élément intégral à la dynamique de l’intimidation. Les participantes ont décrit des sentiments de vulnérabilité et d’impuissance, et elles ont exprimé leur réticence à répondre avec assurance au conflit, et leur croyance que si elles répondent à l’intimidation avec assurance, la conséquence sera catastrophique. Les conclusions de l’étude soutiennent l’utilisation de l’outil ERC et son intégration dans les programmes de premier cycle en sciences infirmières

Temperature compensation of aerobic capacity and performance in the Antarctic pteropod, \u3cem\u3eClione antarctica\u3c/em\u3e, compared with its northern congener, \u3cem\u3eC. limacina\u3c/em\u3e

In ectotherms living in cold waters, locomotory performance is constrained by a slower generation of the ATP that is needed to fuel muscle contraction. Both polar and temperate pteropods of the genus Clione, however, are able to swim continuously by flapping their parapodia (wings) at comparable frequencies at their respective habitat temperatures. Therefore, we expected polar species to have increased aerobic capacities in their wing muscles when measured at common temperatures. We investigated muscle and mitochondrial ultrastructure of Clione antarctica from the Southern Ocean (−1.8°C) and populations of a sister species, Clione limacina, from the Arctic (−0.5 to 3°C) and from the North Atlantic (10°C). We also measured oxygen consumption and the activity of the mitochondrial enzyme citrate synthase (CS) in isolated wings of the two species. The Antarctic species showed a substantial up-regulation of the density of oxidative muscle fibers, but at the expense of fast-twitch muscle fibers. Mitochondrial capacity was also substantially increased in the Antarctic species, with the cristae surface density (58.2±1.3μm2μm−3) more than twice that found in temperate species (34.3±0.8μm2μm−3). Arctic C. limacina was intermediate between these two populations (43.7±0.5μm2μm−3). The values for cold-adapted populations are on par with those found in high-performance vertebrates. As a result of oxidative muscle proliferation, CS activity was 4-fold greater in C. antarctica wings than in temperate C. limacina when measured at a common temperature (20°C). Oxygen consumption of isolated wing preparations was comparable in the two species when measured at their respective habitat temperatures. These findings indicate complete compensation of ATP generation in wing muscles across a 10°C temperature range, which supports similar wing-beat frequencies during locomotion at each species\u27 respective temperature. The elevated capacity in the wing muscles is reflected in the partial compensation of whole-animal oxygen consumption and feeding rates

Tempeh flour as a substitute for soybean flour in coconut cookies.

The objective of this study was to prepare roasted and lyophilized tempeh flour with soybean cultivar BRS 267 to apply them in the formulation of coconut biscuits. The cookies produced with whole soy flour and mixed flour of soybean and tempeh were evaluated for proximate composition, fatty acid profile, and isoflavone aglycones in order to verify the effects of inoculation with the fungus Rhizopus oligosporus and those of the drying processes of roasting and lyophilization on the chemical characteristics of the final product. Sensory acceptance and purchase intention of the formulated products were also evaluated. The results indicate the maintenance of linolenic acid, which is important in the prevention of coronary diseases, and an increase in the aglycones levels when the tempeh flour was used. Lipids and proteins showed differences, and the sensory analyses demonstrated similarity between the cookies with satisfactory scores for aroma, flavor, texture, and overall acceptability for both samples. when compared to the control. Purchase intent was also positive for the lyophilized and toasted tempeh flours, thus enabling the use of the roasting process as a simple drying method, for processing tempeh and obtaining a flour rich in proteins and aglycones that can be used as a partial substitute for soy flour in cookies and other bakery products