On the origin of the selectivity of plasmidic H-NS towards horizontally acquired DNA: Linking H-NS oligomerization and cooperative DNA binding

The nucleoid-associated protein H-NS is a global modulator of the expression of genes associated with adaptation to environmental changes. A variant of H-NS expressed in the R27 plasmid was previously shown to selectively modulate the expression of horizontally acquired genes, with minimal effects on core genes that are repressed by the chromosomal form of H-NS. Both H-NS proteins are formed by an oligomerization domain and a DNA-binding domain, which are connected by a linker that is highly flexible in the absence of DNA. We studied DNA binding by means of oligomer-forming chimeric proteins in which domains of the chromosomal and plasmidic variants are exchanged, as well as in monomeric truncated forms containing the DNA-binding domain and variable portions of the linker. Point mutations in the linker were also examined in full-length and truncated H-NS constructs. These experiments show that the linker region contributes to DNA binding affinity and that it is a main component of the distinct DNA binding properties of chromosomal and plasmidic H-NS. We propose that interactions between the linker and DNA limit the flexibility of the connection between H- NS oligomerization and DNA binding and provide an allosteric indirect readout mechanism to detect long- range distortions of DNA, thus enabling discrimination between core and horizontally acquired DNA.

Helena Valentí, fúria i traducció

La filòloga i novel·lista Helena Valentí i Petit (Barcelona, 1940-1990) s’exilià de ben jove a Anglaterra, on buscà en la traducció el mitjà de vida. Entre altres autors i autores, traslladà al castellà William Blake, Marilyn French, Nicholas Guild, Najib Mahfuz, Harold Robbins, Bernice Rubens, Roger T. Taylor i Doris Lessing, de la qual traduí El quadern daurat. De retorn a Catalunya, el 1974, decidí compaginar la traducció amb la narrativa pròpia. Girà a la llengua catalana Al far i Una cambra pròpia de l’anglesa Virginia Woolf i La garden party i altres contes i Un home casat i altres crueltats de la neozelandesa Katherine Mansfield. En els anys vuitanta traslladà El factor humà de Graham Greene i Jo, Claudi de Robert Graves, i féu una breu incursió en la narrativa per a joves. Viatges indiscrets de Lisa St. Aubin, un recull de contes d’autores del segle XX, fou l’última traducció.

Biosynthesis of panaxynol and panaxydol in Panax ginseng

The natural formation of the bioactive C17-polyacetylenes (−)-(R)-panaxynol and panaxydol was analyzed by 13C-labeling experiments. For this purpose, plants of Panax ginseng were supplied with 13CO2 under field conditions or, alternatively, sterile root cultures of P. ginseng were supplemented with [U-13C6]glucose. The polyynes were isolated from the labeled roots or hairy root cultures, respectively, and analyzed by quantitative NMR spectroscopy. The same mixtures of eight doubly 13C-labeled isotopologues and one single labeled isotopologue were observed in the C17-polyacetylenes obtained from the two experiments. The polyketide-type labeling pattern is in line with the biosynthetic origin of the compounds via decarboxylation of fatty acids, probably of crepenynic acid. The 13C-study now provides experimental evidence for the biosynthesis of panaxynol and related polyacetylenes in P. ginseng under in planta conditions as well as in root cultures. The data also show that 13CO2 experiments under field conditions are useful to elucidate the biosynthetic pathways of metabolites, including those from roots.

Transcriptional regulator PRDM12 is essential for human pain perception.

Pain perception has evolved as a warning mechanism to alert organisms to tissue damage and dangerous environments. In humans, however, undesirable, excessive or chronic pain is a common and major societal burden for which available medical treatments are currently suboptimal. New therapeutic options have recently been derived from studies of individuals with congenital insensitivity to pain (CIP). Here we identified 10 different homozygous mutations in PRDM12 (encoding PRDI-BF1 and RIZ homology domain-containing protein 12) in subjects with CIP from 11 families. Prdm proteins are a family of epigenetic regulators that control neural specification and neurogenesis. We determined that Prdm12 is expressed in nociceptors and their progenitors and participates in the development of sensory neurons in Xenopus embryos. Moreover, CIP-associated mutants abrogate the histone-modifying potential associated with wild-type Prdm12. Prdm12 emerges as a key factor in the orchestration of sensory neurogenesis and may hold promise as a target for new pain therapeutics.

Retinal damage induced by commercial light emitting diodes (LEDs).

Spectra of "white LEDs" are characterized by an intense emission in the blue region of the visible spectrum, absent in daylight spectra. This blue component and the high intensity of emission are the main sources of concern about the health risks of LEDs with respect to their toxicity to the eye and the retina. The aim of our study was to elucidate the role of blue light from LEDs in retinal damage. Commercially available white LEDs and four different blue LEDs (507, 473, 467, and 449nm) were used for exposure experiments on Wistar rats. Immunohistochemical stain, transmission electron microscopy, and Western blot were used to exam the retinas. We evaluated LED-induced retinal cell damage by studying oxidative stress, stress response pathways, and the identification of cell death pathways. LED light caused a state of suffering of the retina with oxidative damage and retinal injury. We observed a loss of photoreceptors and the activation of caspase-independent apoptosis, necroptosis, and necrosis. A wavelength dependence of the effects was observed. Phototoxicity of LEDs on the retina is characterized by a strong damage of photoreceptors and by the induction of necrosis.

Uptake and factors that influence the use of ‘sit less, move more’ occupational intervention strategies in Spanish office employees

Background Little is known about the types of ‘sit less, move more’ strategies that appeal to office employees, or what factors influence their use. This study assessed the uptake of strategies in Spanish university office employees engaged in an intervention, and those factors that enabled or limited strategy uptake. Methods The study used a mixed method design. Semi-structured interviews were conducted with academics and administrators (n = 12; 44 ± 12 mean SD age; 6 women) at three points across the five-month intervention, and data used to identify factors that influenced the uptake of strategies. Employees who finished the intervention then completed a survey rating (n = 88; 42 ± 8 mean SD age; 51 women) the extent to which strategies were used [never (1) to usually (4)]; additional survey items (generated from interviewee data) rated the impact of factors that enabled or limited strategy uptake [no influence (1) to very strong influence (4)]. Survey score distributions and averages were calculated and findings triangulated with interview data. Results Relative to baseline, 67% of the sample increased step counts post intervention (n = 59); 60% decreased occupational sitting (n = 53). ‘Active work tasks’ and ‘increases in walking intensity’ were the strategies most frequently used by employees (89% and 94% sometimes or usually utilised these strategies); ‘walk-talk meetings’ and ‘lunchtime walking groups’ were the least used (80% and 96% hardly ever or never utilised these strategies). ‘Sitting time and step count logging’ was the most important enabler of behaviour change (mean survey score of 3.1 ± 0.8); interviewees highlighted the motivational value of being able to view logged data through visual graphics in a dedicated website, and gain feedback on progress against set goals. ‘Screen based work’ (mean survey score of 3.2 ± 0.8) was the most significant barrier limiting the uptake of strategies. Inherent time pressures and cultural norms that dictated sedentary work practices limited the adoption of ‘walk-talk meetings’ and ‘lunch time walking groups’. Conclusions The findings provide practical insights into which strategies and influences practitioners need to target to maximise the impact of ‘sit less, move more’ occupational intervention strategies.

Interrogantes educativos desde la sociedad del conocimiento

La Sociedad del conocimiento y la forma como hoy gestionamos la información se han traducido en la introducción de las TICs en el sistema educativo, incorporando muchas veces la terminología (Escuela 2.0, aprendizaje digital, ) pero no los auténticos cambios que esas tecnologías han provocado en la Sociedad y, por ende, en nuestros estudiantes. En este artículo se plantean 9 de los temas más relevantes que son objeto de discusión social: la autoridad del experto cuestionada por la inteligencia colectiva, la superficialidad del conocimiento denunciada por Carr, la inestabilidad de los documentos y de sus contenidos sujetos a cambio en cualquier momento, la inabarcabilidad de la información que hace "imposible incluso al especialista estar al día", los derechos del autor y el propio concepto de autor en la era de la "segunda oralidad", la democracia informativa como alternativa al "cuarto poder", el acceso global superando fronteras, el respeto a la privacidad y la identidad digital. Frente a esos temas la escuela o la universidad introducen las tecnologías sin alterar su modelo ni sus prácticas. El objetivo final de este texto es invitar a los educadores a reflexionar sobre su práctica docente.

Interrogantes educativos desde la sociedad del conocimiento

La Sociedad del conocimiento y la forma como hoy gestionamos la información se han traducido en la introducción de las TICs en el sistema educativo, incorporando muchas veces la terminología (Escuela 2.0, aprendizaje digital, ) pero no los auténticos cambios que esas tecnologías han provocado en la Sociedad y, por ende, en nuestros estudiantes. En este artículo se plantean 9 de los temas más relevantes que son objeto de discusión social: la autoridad del experto cuestionada por la inteligencia colectiva, la superficialidad del conocimiento denunciada por Carr, la inestabilidad de los documentos y de sus contenidos sujetos a cambio en cualquier momento, la inabarcabilidad de la información que hace "imposible incluso al especialista estar al día", los derechos del autor y el propio concepto de autor en la era de la "segunda oralidad", la democracia informativa como alternativa al "cuarto poder", el acceso global superando fronteras, el respeto a la privacidad y la identidad digital. Frente a esos temas la escuela o la universidad introducen las tecnologías sin alterar su modelo ni sus prácticas. El objetivo final de este texto es invitar a los educadores a reflexionar sobre su práctica docente.

Self-reported sitting time and physical activity: interactive associations with mental well-being and productivity in office employees

Abstract Background: Little is known about how sitting time, alone or in combination with markers of physical activity (PA), influences mental well-being and work productivity. Given the need to develop workplace PA interventions that target employees’ health related efficiency outcomes; this study examined the associations between self-reported sitting time, PA, mental well-being and work productivity in office employees. Methods: Descriptive cross-sectional study. Spanish university office employees (n = 557) completed a survey measuring socio-demographics, total and domain specific (work and travel) self-reported sitting time, PA (International Physical Activity Questionnaire short version), mental well-being (Warwick-Edinburg Mental Well-Being Scale) and work productivity (Work Limitations Questionnaire). Multivariate linear regression analyses determined associations between the main variables adjusted for gender, age, body mass index and occupation. PA levels (low, moderate and high) were introduced into the model to examine interactive associations. Results: Higher volumes of PA were related to higher mental well-being, work productivity and spending less time sitting at work, throughout the working day and travelling during the week, including the weekends (p < 0.05). Greater levels of sitting during weekends was associated with lower mental well-being (p < 0.05). Similarly, more sitting while travelling at weekends was linked to lower work productivity (p < 0.05). In highly active employees, higher sitting times on work days and occupational sitting were associated with decreased mental well-being (p < 0.05). Higher sitting times while travelling on weekend days was also linked to lower work productivity in the highly active (p < 0.05). No significant associations were observed in low active employees. Conclusions: Employees’ PA levels exerts different influences on the associations between sitting time, mental well-being and work productivity. The specific associations and the broad sweep of evidence in the current study suggest that workplace PA strategies to improve the mental well-being and productivity of all employees should focus on reducing sitting time alongside efforts to increase PA.

Patterns of impact resulting from a 'sit less, move more' web-based program in sedentary office employees

Purpose Encouraging office workers to ‘sit less and move more’ encompasses two public health priorities. However, there is little evidence on the effectiveness of workplace interventions for reducing sitting, even less about the longer term effects of such interventions and still less on dual-focused interventions. This study assessed the short and mid-term impacts of a workplace web-based intervention (Walk@WorkSpain, W@WS; 2010-11) on self-reported sitting time, step counts and physical risk factors (waist circumference, BMI, blood pressure) for chronic disease. Methods Employees at six Spanish university campuses (n=264; 42±10 years; 171 female) were randomly assigned by worksite and campus to an Intervention (used W@WS; n=129; 87 female) or a Comparison group (maintained normal behavior; n=135; 84 female). This phased, 19-week program aimed to decrease occupational sitting time through increased incidental movement and short walks. A linear mixed model assessed changes in outcome measures between the baseline, ramping (8 weeks), maintenance (11 weeks) and followup (two months) phases for Intervention versus Comparison groups.A significant 2 (group) × 2 (program phases) interaction was found for self-reported occupational sitting (F[3]=7.97, p=0.046), daily step counts (F[3]=15.68, p=0.0013) and waist circumference (F[3]=11.67, p=0.0086). The Intervention group decreased minutes of daily occupational sitting while also increasing step counts from baseline (446±126; 8,862±2,475) through ramping (+425±120; 9,345±2,435), maintenance (+422±123; 9,638±3,131) and follow-up (+414±129; 9,786±3,205). In the Comparison group, compared to baseline (404±106), sitting time remained unchanged through ramping and maintenance, but decreased at follow-up (-388±120), while step counts diminished across all phases. The Intervention group significantly reduced waist circumference by 2.1cms from baseline to follow-up while the Comparison group reduced waist circumference by 1.3cms over the same period. Conclusions W@WSis a feasible and effective evidence-based intervention that can be successfully deployed with sedentary employees to elicit sustained changes on “sitting less and moving more”.

War Requiem op. 66

Digitoitu 5. 1. 2009

True believers: the recption of Descartes's meditations by Malebranche and Huet

Both Nicholas Malebranche and Pierre-Daniel Huet were at first positively influenced by Descartes's Meditations, and both came to perceive shortcomings in that work. With respect to mind-body dualism, Malebranche attempted to strengthen Descartes's position by jettisoning clarity and distinctness basing it instead on a principle of intentionality. Huet jettisoned the whole position in favor of skepticism. The source of their different responses lay in their different estimations of Descartes's integrity.

Eettinen kasvu ja dialogisuus draaman näyttämöllä : valokiilassa päiväkodin draamaprosessi

This research is a phenomenological-hermeneutic case-study based on the methods of action research in which narrative methods are used to examine a process drama carried out in a day-care centre, focusing on its dialogicality and possibilities of offering children and adults ethical problems to examine and solve. A process drama built around a story was carried out in a Finnish day-care centre in 1999 with the aim of bringing ethical education to the level of conscious consideration and action. The research consists of two case-studies. The first focuses on Risto, one of the children who participated in the process, his actions in group situations, his commitment to the rules set by the leaders, his attitude towards the group and its members as well as the common agreements concerning the group, and his solutions to fictive dilemmas in relation to Lawrence Kohlberg’s and Carol Gilligan’s concepts of justice and care. On this basis conclusions are made on how drama can be applied to dealing with ethical dilemmas with children aged four to seven. The second case-study searches for ethical themes and signs of dialogicality in the story that was created together by the children and leaders, and in the action that took place in the drama sessions. The subjects of this study consist of two groups participating in the process drama, both consisting of seven children aged four to seven. Narratives were written on each child based on his/her participation in four drama sessions selected to be used in this study. The narratives include the writer’s interpretations of the dialogicality of the drama and the ethical themes observed and recognised in the videos and in the transcriptions of the video recordings. The description and interpretation of the dialogicality and the ethical themes observed in the drama sessions is based on the researcher’s dialogue with the writings of Georg Henrik von Wright, Martin Buber and Mihail Bahtin, as well as Nicholas C. Burbules’ definitions of the basic conditions for dialogical teaching. As a result of the study, drama activity proved to be a means by which dialogically abstract ethical questions and conflicts could be dealt with even with young children and which revealed the zone of proximal development of both children and adults. Drama became a stage for ethical growth and dialogicality, and the common play of children and adults could be seen as an indicator of deep dialogicality. On the basis of this study, it can be said that drama is a very suitable way of establishing a shape and form of ethical education in which it is possible to make planned, target-oriented progress and which can be consciously observed by following the development of both the child and the educator.

24+1 kansainvälisten suhteiden perusoppikirjaa : havaintoja ja arvioita

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