The influence of pain obesity and quadriceps strength on the gait of osteoarthritis patients

info:eu-repo/semantics/publishedVersio

Peroxisomal metabolism alterations associated to Z. aethiopica spathe senescence and regreening

The development of the C3 monocot Zantedeschia aethiopica floral spathe has been used as a natural model for studying the physiological and biochemical features of senescence. This photosynthetic leaf-like organ undergoes senescence displaying the common features of leaf senescence, such as loss of protein, chlorophyll and a decline on photosynthetic ability. Fruiting inhibits the ongoing spathe senescence and the regreening of its abaxial parenchyma cells is observed. Previous results have suggested that during the spathe whitening the peroxisomes differentiate into glyoxysomes and that the regreening process is followed by their conversion back into peroxisomes, resulting in the re-acquisition of photorespiratory capacity. In this work, changes in peroxisomal metabolism were studied in what concerns key-enzymes of glyoxylate and glycolate pathways. An increase in isocitrate lyase (ICL) activity during the late stages of spathe whitening suggests that there is an induction of glyoxysomal metabolism. The increase of hydroxypyruvate reductase (HPR) activity during spathe regreening, accompanied with the decrease of the glyoxylate key-enzyme ICL, points to an induction of leaf-type peroxisome metabolism thus suggesting the conversion of glyoxysomes back into peroxisomes. This hypothesis is further supported by the expression analysis of genes encoding enzymes from glycolate and glyoxylate pathways. The results will be discussed taking into account hydrogen peroxide levels evaluated during the time course of Z. aethiopica spathe development.Fundação para a Ciência e a Tecnologia (FCT) - grant ref. SFRH/BD/12081/2003

Changes in peroxisomal metabolism during Zantedeschia aethiopica spathe senescence and regreening : differential expression of two catalase genes

Poster apresentado no 14th Federation of European Societies of Plant Biology Congress, em 2004, Cracóvia, Polónia.Zantedeschia aethiopica spathe undergoes whitening displaying the common features of foliar senescence. After pollination, the spathe region surrounding the fruits undergo regreening, thus reacquiring photosynthetic ability. In this work, changes in peroxisomal metabolism were studied in what concerns key-enzymes of glyoxylate and glycolate pathways. Putative roles for CAT1 and CAT2 are discussed. Material and Methods: Spathes during the time course of senescence and regreening were harvested from field-grown plants. The content in hydrogen peroxide (H2O2) followed Loreto et al (2001). Catalase activity was determined by following the decomposition of H2O2 at 240 nm (Aebi, 1983). Northern analysis was performed using Z. aethiopica Cat1 (AF207906) and Cat2 (AF332973) cDNAs as homologous probes. The activity of the glyoxysomal-marker enzyme isocitrate lyase (ICL) and leaf-type peroxisomal marker enzyme hydroxypyruvate reductase (HPR) were determined according to Zelitch (1988) and Liang et al. (1984), respectively. Results and Conclusions: Changes in ICL and HPR activitiy suggest that during Z. aethiopica spathe development there is an induction of glyoxysomal metabolism during the late stages of whitening, followed by the induction of leaf-type peroxisome metabolism during regreening. In addition, the levels of H2O2 during the initial stages of spathe whitening seems to paralell catalase activity. As the transcript levels of Cat1 increase until the late stages of spathe whitening, CAT1 is probably associated to scavenging of glyoxysomal H2O2. The higher expression of Cat2 during spathe regreening suggests that CAT2 is specifically associated to photorespiratory H2O2 decomposition. However, as Cat1 expression is also strongly induced during regreening, a dual role of CAT1 in scavenging leaf-type peroxisomal and glyoxysomal H2O2 can also be considered.Fundação para a Ciência e a Tecnologia (FCT) - Ref. SFRH/BD/12081/2003

Changes in peroxisomal metabolism during Z. aethiopica spathe senescence and regreening : differential expression of two catalase genes

Zantedeschia aethiopica spathe undergoes whitening displaying the common features of foliar senescence. After pollination, the spathe region surrounding the fruits undergo regreening, thus reacquiring photosynthetic ability. In this work, changes in peroxisomal metabolism were studied in what concerns key-enzymes of glyoxylate and glycolate pathways. Putative roles for CAT1 and CAT2 are discussed. Material and Methods: Spathes during the time course of senescence and regreening were harvested from field-grown plants. The content in hydrogen peroxide (H2O2) followed Loreto et al (2001). Catalase activity was determined by following the decomposition of H2O2 at 240 nm (Aebi, 1983). Northern analysis was performed using Z. aethiopica Cat1 (AF207906) and Cat2 (AF332973) cDNAs as homologous probes. The activity of the glyoxysomal-marker enzyme isocitrate lyase (ICL) and leaf-type peroxisomal marker enzyme hydroxypyruvate reductase (HPR) were determined according to Zelitch (1988) and Liang et al. (1984), respectively. Results and Conclusions: Changes in ICL and HPR activitiy suggest that during Z. aethiopica spathe development there is an induction of glyoxysomal metabolism during the late stages of whitening, followed by the induction of leaf-type peroxisome metabolism during regreening. In addition, the levels of H2O2 during the initial stages of spathe whitening seems to paralell catalase activity. As the transcript levels of Cat1 increase until the late stages of spathe whitening, CAT1 is probably associated to scavenging of glyoxysomal H2O2. The higher expression of Cat2 during spathe regreening suggests that CAT2 is specifically associated to photorespiratory H2O2 decomposition. However, as Cat1 expression is also strongly induced during regreening, a dual role of CAT1 in scavenging leaf-type peroxisomal and glyoxysomal H2O2 can also be considered.Fundação para a Ciência e a Tecnologia (FCT) - grant ref. SFRH/BD/10899/2002

Stress appraisal, coping, and work engagement among police recruits: an exploratory study.

This study investigated the influence of stress appraisal and coping on work engagement levels (Absorption, Vigour, and Dedication) of police recruits. Participants were 387 men, ages 20 to 33 yr. (M = 24.1, SD = 2.4), in their last month of academy training before becoming police officers. Partially in support of predictions, work engagement was associated with Stressor control perceived, but not Stress intensity experienced over a self-selected stressor. Although the three dimensions of work engagement were explained by Stressor control and coping, Absorption was the dimension better explained by these variables. Police recruits reporting higher Absorption, Vigour, and Dedication reported using more Active coping and less Behavioural disengagement. Results showed that stress appraisal and coping are important variables influencing work engagement among police recruits. Findings suggested that future applied interventions fostering work engagement among police recruits should reinforce perceptions of control over a stressor as well as Active coping strategies

Stigma consciousness and self-efficacy in infertile couples: correlation and gender differences

Introducción: La infertilidad es cada vez mayor en las sociedades occidentales y sus consecuencias son muy problemáticas una vez que los problemas individuales y familiares se detectan en las parejas infértiles (IC). Investigaciones recientes sugieren que el estigma consciente (SC) y la autoeficacia (ES) pueden verse afectadas en estas parejas. Hipótesis: H1 - existe una correlación significativamente negativa entre SC y SE en hombres infértiles (IM) y en mujeres infértiles (IW). H2-IW muestran niveles más altos de SC y más bajos niveles de SE en comparación con IM. Método: Los participantes - IC (n = 59) se reclutaron en la consulta de un hospital de infertilidad. Instrumentos: se empleó un cuestionario sociodemográfico, la versión portuguesa del cuestionario Adapted Stigma Consciousness Questionnaire and of the Infertility Self-efficacy Scale. Procedimiento – a) autorización del Comité ético del Hospital, b) consentimiento informado, c) entrevista con el investigador y aplicación del cuestionario, d) análisis estadístico de la correlación entre SC y SE y de las diferencias entre los hombres infértiles y las mujeres en la SC y SE. Resultados: Existe una correlación negativa significativa entre SC y SE en IM y en IW. En comparación con los demás valores, IW presenta niveles significativamente más altos de SC y significativamente más bajos niveles de SE.Introduction: Infertility is increasing in western societies and consequences are deeply problematic once family and individual psychological problems are detected in infertile couples (IC) and rise up during medical treatment. Recent research suggests that stigma consciousness (SC) and self-efficacy (SE) may be affected in these couples. Hypothesis: H1 - There is a significantly negative correlation between SC and SE in infertile men (IM) and in infertile women (IW). H2 – IW show higher levels of SC and lower levels of SE when compared with IM. Method: Participants - IC (n = 59) attending an infertility hospital consultation were recruited. Instruments – a Socio-demographic Questionnaire, the Portuguese versions of the Adapted Stigma Consciousness Questionnaire and of the Infertility Self-efficacy Scale. Procedure – a) authorization of the Hospital’s Ethical Committee, b) Informed Consent, c) interview with the researcher and questionnaires application, d) statistical analysis of the correlation between SC and SE and of the differences between infertile men and women on SC and SE. Results: There is a significant negative correlation between SC and SE both in IM and in IW. When compared with their partners, IW present significantly higher levels of SC and significantly lower levels of SE.peerReviewe

The electromagnetic effects in Ke4K_{e4} decay

The final state interaction of pions in $K_{e4}$ decay allows one to obtain the value of the isospin and angular momentum zero $\pi\pi$ scattering length $a_0^0$.We take into account the electromagnetic interaction of pions and isospin symmetry breaking effects caused by different masses of neutral and charged pions and estimate the impact of these effects on the procedure of scattering length extraction from $K_{e4}$ decay.Comment: 8 pages,1 figur

Evidence of magnetic accretion in an SW Sex star: discovery of variable circular polarization in LS Pegasi

We report on the discovery of variable circular polarization in the SW Sex star LS Pegasi. The observed modulation has an amplitude of ~0.3 % and a period of 29.6 minutes, which we assume as the spin period of the magnetic white dwarf. We also detected periodic flaring in the blue wing of Hbeta, with a period of 33.5 minutes. The difference between both frequencies is just the orbital frequency, so we relate the 33.5-min modulation to the beat between the orbital and spin period. We propose a new accretion scenario in SW Sex stars, based on the shock of the disk-overflown gas stream against the white dwarf's magnetosphere, which extends to the corotation radius. From this geometry, we estimate a magnetic field strength of B(1) ~ 5-15 MG. Our results indicate that magnetic accretion plays an important role in SW Sex stars and we suggest that these systems are probably Intermediate Polars with the highest mass accretion rates.Comment: Accepted by ApJ Letters. LaTeX, 14 pages, 3 PostScript figure

Polyion Adsorption onto Catanionic Surfaces. A Monte Carlo Study

The adsorption of a single and negatively charged polyion with varying flexibility onto a surface carrying both negative and positive charges representing a charged membrane surface has been investigated by using a simple model employing Monte Carlo simulations. The polyion was represented by a sequence of negatively charged hard spheres connected with harmonic bonds. The charged surface groups were also represented by charged hard spheres, and they were positioned on a hard surface slightly protruding into the solution. The surface charges were either frozen in a liquidlike structure or laterally mobile. With a large excess of positive surface charges, the classical picture of a strongly adsorbed polyion with an extended and flat configuration emerged. However, adsorption also appeared at a net neutral surface or at a weakly negatively charged surface, and at these conditions the adsorption was stronger with a flexible polyion as compared to a semiflexible one, two features not appearing in simpler models containing homogeneously charged surfaces. The presence of charged surface patches (frozen surface charges) and the ability of polarization of the surface charges (mobile surface charges) are the main reasons for the enhanced adsorption. The stronger adsorption with the flexible chain is caused by its greater ability to spatially correlate with the surface charges