Demographic characteristics of exploited tropical lutjanids: a comparative analysis

Demographic parameters from seven exploited coral reef lutjanid species were compared as a case study of the implications of intrafamily variation in life histories for multispecies harvest management. Modal lengths varied by 4 cm among four species (Lutjanus fulviflamma, L. vitta, L. carponotatus, L. adetii), which were at least 6 cm smaller than the modal lengths of the largest species (L. gibbus, Symphorus nematophorus, Aprion virescens). Modal ages, indicating ages of full selection to fishing gear, were 10 years or less for all species, but maximum ages ranged from 12 (L. gibbus) to 36 years (S. nematophorus). Each species had a unique growth pattern, with differences in length-at-age and mean asymptotic fork length (L∞), but smaller species generally grew fast during the first 1–2 years of life and larger species grew more slowly over a longer period. Total mortality rates varied among species; L. gibbus had the highest mortality and L. fulviflamma, the lowest mortality. The variability in life history strategies of these tropical lutjanids makes generalizations about lutjanid life histories difficult, but the fact that all seven had characteristics that would make them particularly vulnerable to fishing indicates that harvest of tropical lutjanids should be managed with caution

A brief mindfulness-based intervention reduces eating disorder symptoms and improves eating self-efficacy and emotion regulation among adults seeking bariatric surgery

Background Up to 64% of bariatric (weight-loss) surgery-seeking adults report eating disorder (ED) symptoms (i.e., binge eating, emotional eating, addictive-like eating, and grazing) that can interfere with surgery outcomes. Well-designed pre-surgical interventions targeting eating behaviours may reduce ED symptoms and protect against suboptimal surgery outcomes. Objectives Provide proof-of-concept data to inform the design and optimization of a pre-surgical mindfulness-based intervention (MBI) for ED symptoms. Evaluate whether the MBI produces meaningful improvements in ED symptoms and clarify the mechanisms-of-action by which the MBI impacts ED symptoms. Methods Twenty-one pre-surgical patients with obesity and ED symptoms referred to a MBI completed self-report measures of addictive-like eating, binge eating, emotional eating, grazing, mindful eating, eating self-efficacy, and emotion regulation pre-(T1) and post-(T2) MBI. Results Repeated-measures ANOVAs revealed improvements in binge eating symptoms (F (1,20) = 30.38, ηp2 = .60, p < .001) and grazing (F (1,20) = 7.57, ηp2 = .28, p = .012), pre- to post-MBI. Adjusting for multiple comparisons, no significant improvements were found for addictive-like eating or emotional eating. Eating self-efficacy (F (1,20) = 29.70, ηp2 = .60, p < .001) and emotion regulation (F (1,20) = 7.18, ηp2 = .26, p = .014) improved, while mindful eating decreased (F (1,20) = 16.25, ηp2 = .45, p = .001), following the MBI. Bivariate correlations found associations between improvements in the mechanism of eating self-efficacy and improvements in the ED symptom of grazing pre- to post-MBI (r = 0.46, p < .05).  As well, improvements in emotion regulation were associated with positive changes in binge and emotional eating and grazing (r = 0.55, p < .001, r = 0.66, p < .001, r = 0.61, p < .05, respectively). Conclusions After participating in the MBI binge eating, grazing, eating self-efficacy, and emotion regulation abilities improved. Further work is needed to understand and mitigate deterioration in mindful eating. Moreover, acceptability and feasibility of the MBI should be assessed prior to testing the MBI in a large-scale efficacy trial. Future research should assess the the impact of this intervention on post-surgery weight-loss, weight-loss maintenance, and maintenance of improvements in ED symptoms

Effects of increasing the affinity of CarD for RNA polymerase on Mycobacterium tuberculosis growth, rRNA transcription, and virulence

CarD is an essential RNA polymerase (RNAP) interacting protein in Mycobacterium tuberculosis that stimulates formation of RNAP-promoter open complexes. CarD plays a complex role in M. tuberculosis growth and virulence that is not fully understood. Therefore, to gain further insight into the role of CarD in M. tuberculosis growth and virulence, we determined the effect of increasing the affinity of CarD for RNAP. Using site-directed mutagenesis guided by crystal structures of CarD bound to RNAP, we identified amino acid substitutions that increase the affinity of CarD for RNAP. Using these substitutions, we show that increasing the affinity of CarD for RNAP increases the stability of the CarD protein in M. tuberculosis. In addition, we show that increasing the affinity of CarD for RNAP increases the growth rate in M. tuberculosis without affecting 16S rRNA levels. We further show that increasing the affinity of CarD for RNAP reduces M. tuberculosis virulence in a mouse model of infection despite the improved growth rate in vitro. Our findings suggest that the CarD-RNAP interaction protects CarD from proteolytic degradation in M. tuberculosis, establish that growth rate and rRNA levels can be uncoupled in M. tuberculosis and demonstrate that the strength of the CarD-RNAP interaction has been finely tuned to optimize virulence. IMPORTANCE Mycobacterium tuberculosis, the causative agent of tuberculosis, remains a major global health problem. In order to develop new strategies to battle this pathogen, we must gain a better understanding of the molecular processes involved in its survival and pathogenesis. We have previously identified CarD as an essential transcriptional regulator in mycobacteria. In this study, we detail the effects of increasing the affinity of CarD for RNAP on transcriptional regulation, CarD protein stability, and virulence. These studies expand our understanding of the global transcription regulator CarD, provide insight into how CarD activity is regulated, and broaden our understanding of prokaryotic transcription

Characterization of a New mtDNA Minicircle in a Chewing Louse, Geomydoecus aurei

The mitochondrion, an organelle responsible for generating cellular energy, is unlike the majority of organelles in animal cells. Because of its symbiotic origins, the mitochondrion contains its own genetic information (mtDNA) that is predominantly maternally inherited. In most animals, the mitochondrial DNA is arranged in one circular chromosome containing 13 protein coding genes, 22 tRNAs and two rRNAs. In Geomydoecus aurei, a chewing louse, these same genes have been disbursed among at least 13 independent minicircle chromosomes. We have worked to map this atypical genome to gain insights into its development and to further understanding of genomic rearrangements in this important genetic material. Identification and characterization of the unique nature of this mtDNA may lead to a better understanding of many debilitating disorders associated with mitochondrial dysfunction

Resolving the cofactor-binding site in the proline biosynthetic enzyme human pyrroline-5-carboxylate reductase 1

Pyrroline-5-carboxylate reductase (PYCR) is the final enzyme in proline biosynthesis, catalyzing the NAD(P)H-dependent reduction of [?]1-pyrroline-5-carboxylate (P5C) to proline. Mutations in the PYCR1 gene alter mitochondrial function and cause the connective tissue disorder cutis laxa. Furthermore, PYCR1 is overexpressed in multiple cancers, and the PYCR1 knock-out suppresses tumorigenic growth, suggesting that PYCR1 is a potential cancer target. However, inhibitor development has been stymied by limited mechanistic details for the enzyme, particularly in light of a previous crystallographic study that placed the cofactor-binding site in the C-terminal domain rather than the anticipated Rossmann fold of the N-terminal domain. To fill this gap, we report crystallographic, sedimentation- velocity, and kinetics data for human PYCR1. Structures of binary complexes of PYCR1 with NADPH or proline determined at 1.9 Å resolution provide insight into cofactor and substrate recognition.WeseeNADPHbound to the Rossmann fold, over 25 Å from the previously proposed site. The 1.85 Å resolution structure of a ternary complex containing NADPH and a P5C/proline analog provides a model of the Michaelis complex formed during hydride transfer. Sedimentation velocity shows that PYCR1 forms a concentration-dependent decamer in solution, consistent with the pentamer-of-dimers assembly seen crystallographically. Kinetic and mutational analysis confirmed several features seen in the crystal structure, including the importance of a hydrogen bond between Thr-238 and the substrate as well as limited cofactor discrimination

Mitochondrial genome of Geomydoecus aurei, a pocket-gopher louse

Parasitic lice demonstrate an unusual array of mitochondrial genome architectures and gene arrangements. We characterized the mitochondrial genome of Geomydoecus aurei, a chewing louse (Phthiraptera: Trichodectidae) found on pocket gophers (Rodentia: Geomyidae) using reads from both Illumina and Oxford Nanopore sequencing coupled with PCR, cloning, and Sanger sequencing to verify structure and arrangement for each chromosome. The genome consisted of 12 circular mitochondrial chromosomes ranging in size from 1,318 to 2,088 nucleotides (nt). Total genome size was 19,015 nt. All 37 genes typical of metazoans (2 rRNA genes, 22 tRNA genes, and 13 protein-coding genes) were present. An average of 26% of each chromosome was composed of non-gene sequences. Within the nongene region of each chromosome, there was a 79-nt nucleotide sequence that was identical among chromosomes and a conserved sequence with secondary structure that was always followed by a poly-T region. We hypothesize that these regions may be important in the initiation of transcription and DNA replication, respectively. The G. aurei genome shares 8 derived gene clusters with other chewing lice of mammals, but in G. aurei, genes on several chromosomes are not contiguous

Relationship of homestead food production with night blindness among children below 5 years of age in Bangladesh

Abstract Objective To examine the relationship between homestead food production and night blindness among pre-school children in rural Bangladesh in the presence of a national vitamin A supplementation programme. Design A cross-sectional study. Setting A population-based sample of six rural divisions of Bangladesh assessed in the Bangladesh Nutrition Surveillance Project 2001-2005. Subjects A total of 158 898 children aged 12-59 months. Results The prevalence rates of night blindness in children among those who did and did not receive vitamin A capsules in the last 6 months were 0·07 % and 0·13 %, respectively. Given the known effect of vitamin A supplementation on night blindness, the analysis was stratified by children's receipt of vitamin A capsules in the last 6 months. Among children who did not receive vitamin A capsules in the last 6 months, the lack of a home garden was associated with increased odds of night blindness (OR = 3·16, 95 % CI 1·76, 5·68; P = 0·0001). Among children who received vitamin A capsules in the last 6 months, the lack of a home garden was not associated with night blindness (OR = 1·28, 95 % CI 0·71, 2·31; P = 0·4). Conclusions Homestead food production confers a protective effect against night blindness among pre-school children who missed vitamin A supplementation in rural Banglades

Action research in physical education: focusing beyond myself through cooperative learning

This paper reports on the pedagogical changes that I experienced as a teacher engaged in an action research project in which I designed and implemented an indirect, developmentally appropriate and child‐centred approach to my teaching. There have been repeated calls to expunge – or at least rationalise – the use of traditional, teacher‐led practice in physical education. Yet despite the advocacy of many leading academics there is little evidence that such a change of approach is occurring. In my role as teacher‐as‐researcher I sought to implement a new pedagogical approach, in the form of cooperative learning, and bring about a positive change in the form of enhanced pupil learning. Data collection included a reflective journal, post‐teaching reflective analysis, pupil questionnaires, student interviews, document analysis, and non‐participant observations. The research team analysed the data using inductive analysis and constant comparison. Six themes emerged from the data: teaching and learning, reflections on cooperation, performance, time, teacher change, and social interaction. The paper argues that cooperative learning allowed me to place social and academic learning goals on an even footing, which in turn placed a focus on pupils’ understanding and improvement of skills in athletics alongside their interpersonal development