Inactivation of genes coding for mitochondrial Nd7 and Nd9 complex I subunits in Chlamydomonas reinhardtii. Impact of complex I loss on respiration and energetic metabolism.

In Chlamydomonas, unlike in flowering plants, genes coding for Nd7 (NAD7/49kDa) and Nd9 (NAD9/30kDa) core subunits of mitochondrial respiratory-chain complex I are nucleus-encoded. Both genes possess all the features that facilitate their expression and proper import of the polypeptides in mitochondria. By inactivating their expression by RNA interference or insertional mutagenesis, we show that both subunits are required for complex I assembly and activity. Inactivation of complex I impairs the cell growth rate, reduces the respiratory rate, leads to lower intracellular ROS production and lower expression of ROS scavenging enzymes, and is associated to a diminished capacity to concentrate CO2 without compromising photosynthetic capacity.Peer reviewe

Inactivation of genes coding for mitochondrial Nd7 and Nd9 complex I subunits in Chlamydomonas reinhardtii. Impact of complex I loss on respiration and energetic metabolism.

In Chlamydomonas, unlike in flowering plants, genes coding for Nd7 (NAD7/49kDa) and Nd9 (NAD9/30kDa) core subunits of mitochondrial respiratory-chain complex I are nucleus-encoded. Both genes possess all the features that facilitate their expression and proper import of the polypeptides in mitochondria. By inactivating their expression by RNA interference or insertional mutagenesis, we show that both subunits are required for complex I assembly and activity. Inactivation of complex I impairs the cell growth rate, reduces the respiratory rate, leads to lower intracellular ROS production and lower expression of ROS scavenging enzymes, and is associated to a diminished capacity to concentrate CO2 without compromising photosynthetic capacity.Peer reviewe

¿Protege o predispone la actividad física a las adicciones conductuales y otros problemas de autorregulación?

This cross-sectional survey study had the aim of clarifying the relationships between leisure time physical activity (LTPA) and non-drugrelated self-regulation problems (non-drug-related SRPs), including behavioral addictions, and the role of impulsive personality traits therein. Spanish university students (N = 329; Mage = 21.20) completed questionnaires for each of these constructs. Fitness and Bodybuilding LTPA was negatively associated with video gaming-related SRPs, r = -.13, p = .019, 95% CI (bootstrapped) [-.23, -.02], and positively associated with sex-related SRPs, r = .16, p = .005, 95% CI (bootstrapped) [.04, .30]. Endurance LTPA was associated with higher scores in eating-related SRPs, r = .17, p = .003, 95% CI (bootstrapped) [.02, .31]. The proportion of participants presenting scores above the clinically significant threshold in eating-related SRPs was 2.64 times higher for respondents in an Excessive Endurance LTPA cluster compared to the other respondents, Fisher’s exact test, p = .017, OR = 3.10, 95% CI [1.26, 7.63], and the proportion of participants reporting vomiting to control weight was 2.12 times higher, Fisher’s exact test, p = .040, OR = 2.43, 95% CI [1.06, 5.57]. The associations were largely independent of impulsive personality traits. We identified an elevated risk of eating pathology in a subgroup of participants with anomalously high participation in endurance physical activity. This overlap is consistent with the secondary dependence hypothesis of exercise addiction.This cross-sectional survey study had the aim of clarifying the relationships between leisure time physical activity (LTPA) and non-drugrelated self-regulation problems (non-drug-related SRPs), including behavioral addictions, and the role of impulsive personality traits therein. Spanish university students (N = 329; Mage = 21.20) completed questionnaires for each of these constructs. Fitness and Bodybuilding LTPA was negatively associated with video gaming-related SRPs, r = -.13, p = .019, 95% CI (bootstrapped) [-.23, -.02], and positively associated with sex-related SRPs, r = .16, p = .005, 95% CI (bootstrapped) [.04, .30]. Endurance LTPA was associated with higher scores in eating-related SRPs, r = .17, p = .003, 95% CI (bootstrapped) [.02, .31]. The proportion of participants presenting scores above the clinically significant threshold in eating-related SRPs was 2.64 times higher for respondents in an Excessive Endurance LTPA cluster compared to the other respondents, Fisher’s exact test, p = .017, OR = 3.10, 95% CI [1.26, 7.63], and the proportion of participants reporting vomiting to control weight was 2.12 times higher, Fisher’s exact test, p = .040, OR = 2.43, 95% CI [1.06, 5.57]. The associations were largely independent of impulsive personality traits. We identified an elevated risk of eating pathology in a subgroup of participants with anomalously high participation in endurance physical activity. This overlap is consistent with the secondary dependence hypothesis of exercise addiction.Research described in this manuscript has been funded by a grant to the last author, JCP, from the Spanish Government (Ministerio de Economía y Competitividad, Secretaría de Estado de Investigación, Desarrollo e Innovación; Convocatoria 2013 de Proyectos I+D de Excelencia), with reference number PSI2013-45055-P

Chronic pain in families:A cross-sectional study of shared social, behavioural, and environmental influences

Chronic pain is common and creates a significant burden to the individual and society. Emerging research has shown the influence of the family environment on pain outcomes. However, it is not clear what shared factors between family members associate with chronic pain. This study aimed to investigate the family-level contribution to an individual's chronic pain status. This was a cross-sectional study using the Generation Scotland: Scottish Family Health Study data set. This study focused on a nested cohort of dyads (only 2 relatives per family, n = 2714). Multi-level modelling was first performed to estimate the extent of variance in chronic pain at the family level. Then each member of the dyad was randomly assigned as either the exposure or outcome family member, and logistic regression was used to identify shared factors associated with the outcome of chronic pain status. Multi-level modelling showed just under 10% of variation in chronic pain status was at a family level. There was an increase in odds of chronic pain if exposure family member had chronic pain (odds ratio [OR]: 1.30, 95% confidence interval [CI]: 1.02-1.65), if both were women (OR: 1.39, 95% CI: 0.99-1.94), if both were older in age (OR: 1.80, 95% CI: 1.31-2.48), and if both had low household income (OR: 3.27, 95% CI: 1.72-6.21). These findings show that most explanation for chronic pain is still at the individual level. However, some significant shared effects between family members associate with chronic pain, and this highlights the influence of the family context

A forward genetic screen to identify hydrogenase-deficient mutants in the unicellular green alga Chlamydomonas reinhardtii

The ability of the unicellular green alga Chlamydomonas reinhardtii to evolve molecular hydrogen (H2) is due to the presence of oxygen-sensitive Fe-hydrogenases (HydA1/2), expressed in anoxic conditions that drive the photosynthetic electron flow to reduce protons into H2. In order to identify new players involved in H2 photoproduction in Chlamydomonas, an insertion mutant library was generated using cassettes conferring resistance to hygromycin or paromomycin. Hydrogenase activity is physiologically relevant during a transition from dark anoxia to light. In dark anoxic conditions, the cellular redox poise is high and the photosynthetic electron transport chain is fully reduced. Upon illumination, hydrogenase activity allows the reoxidation of photosynthetic intersystem electron carriers until oxic conditions and carbon fixation ability are restored. We thus designed an in vivo fluorescence imaging screen based on the different kinetics of photosynthesis induction between wild type and hydrogenase-deficient mutants [1]. At this stage, three putative hydrogenase mutants have been identified on 10,000 transformants. Molecular characterization of the insertion site of the resistance cassette by TAIL-PCR and genetic analyses of the linkage between the antibiotic resistance and the fluorescence phenotype showed that one mutant was untagged with the resistance while two tagged mutants were deficient for the HydG assembly factor

Photosynthesis in the smallest free-living eukaryotic organism: light utilisation and capture in the picoeukaryote Ostreococcus

Peer reviewe

Health professionals' perceptions of cultural influences on stroke experiences and rehabilitation in Kuwait

This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2012 Informa UK Ltd.Purpose: The aim of this study was to investigate the perceptions of health professionals who treat stroke patients in Kuwait regarding cultural influences on the experience of stroke and rehabilitation in Kuwait. Health professionals interviewed were from a variety of cultural backgrounds thus providing an opportunity to investigate how they perceived the influence of culture on stroke recovery and rehabilitation in Kuwait. Method: Semi-structured interviews were carried out with 12 health professionals with current/recent stroke rehabilitation experience in Kuwait, followed by thematic analysis of the verbatim transcripts. Results: The health professionals identified several features of the Kuwaiti culture that they believed affected the experiences of stroke patients. These were religious beliefs, family involvement, limited education and public information about stroke, prevailing negative attitudes toward stroke, access to finances for private treatment, social stigma and the public invisibility of disabled people, difficulties identifying meaningful goals for rehabilitation, and an acceptance of dependency linked with the widespread presence of maids and other paid assistants in most Kuwaiti homes. Conclusion: To offer culturally sensitive care, these issues should be taken into account during the rehabilitation of Kuwaiti stroke patients in their home country and elsewhere