922 resultados para Spaces physical and symbolic
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We give a sufficient condition for a set of block subspaces in an infinite-dimensional Banach space to be weakly Ramsey. Using this condition we prove that in the Levy-collapse of a Mahlo cardinal, every projective set is weakly Ramsey. This, together with a construction of W. H. Woodin, is used to show that the Axiom of Projective Determinacy implies that every projective set is weakly Ramsey. In the case of co we prove similar results for a stronger Ramsey property. And for hereditarily indecomposable spaces we show that the Axiom of Determinacy plus the Axiom of Dependent Choices imply that every set is weakly Ramsey. These results are the generalizations to the class of projective sets of some theorems from W. T. Gowers, and our paper "Weakly Ramsey sets in Banach spaces."
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Much research studies how individuals cope with disease threat by blaming out-groups and protecting the in-group. The model of collective symbolic coping (CSC) describes four stages by which representations of a threatening event are elaborated in the mass media: awareness, divergence, convergence, and normalization. We used the CSC model to predict when symbolic in-group protection (othering) would occur in the case of the avian influenza (AI) outbreak. Two studies documented CSC stages and showed that othering occurred during the divergence stage, characterized by an uncertain symbolic environment. Study 1 analysed media coverage of AI over time, documenting CSC stages of awareness and divergence. In Study 2, a two-wave repeated cross-sectional survey was conducted just after the divergence stage and a year later. Othering was measured by the number of foreign countries erroneously ticked by participants as having human victims. Individual differences in germ aversion and social dominance orientation interacted to predict othering during the divergence stage but not a year later. Implications for research on CSC and symbolic in-group protection strategies resulting from disease threat are discussed.
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OBJECTIVES: Many nanomaterials (materials with structures smaller than 100 nm) have chemical, physical and bioactive characteristics of interest for novel applications. Considerable research efforts have been launched in this field. This study aimed to study exposure scenarios commonly encountered in research settings. METHODS: We studied one of the leading Swiss universities and first identified all research units dealing with nanomaterials. After a preliminary evaluation of quantities and process types used, a detailed analysis was conducted in units where more than a few micrograms were used per week. RESULTS: In the investigated laboratories, background levels were usually low and in the range of a few thousand particles per cubic centimeter. Powder applications resulted in concentrations of 10,000 to 100,000 particles/cm(3) when measured inside fume hoods, but there were no or mostly minimal increases in the breathing zone of researchers. Mostly low exposures were observed for activities involving liquid applications. However, centrifugation and lyophilization of nanoparticle-containing solutions resulted in high particle number levels (up to 300,000 particles/cm(3)) in work spaces where researchers did not always wear respiratory protection. No significant increases were found for processes involving nanoparticles bound to surfaces, nor were they found in laboratories that were visualizing properties and structure of small amounts of nanomaterials. CONCLUSIONS: Research activities in modern laboratories equipped with control techniques were associated with minimal releases of nanomaterials into the working space. However, the focus should not only be on processes involving nanopowders but should also be on processes involving nanoparticle-containing liquids, especially if the work involves physical agitation, aerosolization or drying of the liquids.
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Background: A holistic perspective on health implies giving careful consideration to the relationship between physical and mental health. In this regard the present study sought to determine the level of Positive Mental Health (PMH) among people with chronic physical health problems, and to examine the relationship between the observed levels of PMH and both physical health status and socio-demographic variables. Methods: The study was based on the Multifactor Model of Positive Mental Health (Lluch, 1999), which comprises six factors: Personal Satisfaction (F1), Prosocial Attitude (F2), Self-control (F3), Autonomy (F4), Problem-solving and Self-actualization (F5), and Interpersonal Relationship Skills (F6). The sample comprised 259 adults with chronic physical health problems who were recruited through a primary care center in the province of Barcelona (Spain). Positive mental health was assessed by means of the Positive Mental Health Questionnaire (Lluch, 1999). Results: Levels of PMH differed, either on the global scale or on specific factors, in relation to the following variables: age: global PMH scores decreased with age (r=-0.129; p=0.038); b) gender: men scored higher on F1 (t=2.203; p=0.028) and F4 (t=3.182; p=0.002), while women scored higher on F2 (t -3.086; p=0.002) and F6 (t=-2.744; p=0.007); c) number of health conditions: the fewer the number of health problems the higher the PMH score on F5 (r=-0.146; p=0.019); d) daily medication: polymedication patients had lower PMH scores, both globally and on various factors; e) use of analgesics: occasional use of painkillers was associated with higher PMH scores on F1 (t=-2.811; p=0.006). There were no significant differences in global PMH scores according to the type of chronic health condition. The only significant difference in the analysis by factors was that patients with hypertension obtained lower PMH scores on the factor Autonomy (t=2.165; p=0.032). Conclusions: Most people with chronic physical health problems have medium or high levels of PMH. The variables that adversely affect PMH are old age, polypharmacy and frequent consumption of analgesics. The type of health problem does not influence the levels of PMH. Much more extensive studies with samples without chronic pathology are now required in order to be able to draw more robust conclusions.
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Dissolution studies have become of great significance because, in most cases, drug dissolution is the rate-limiting step in the absorption process. As occurs with solid oral dosage forms, heterogeneous disperse systems (suspensions) could also have some problems with their in vitro dissolution. The objective of this study was to evaluate influence of the excipients on the release of spironolactone from four alcohol free suspensions (pharmaceutical compounding) of spironolactone 5 mg/mL suitable for pediatric use. Also the comparison of the physical and chemical stability of the suspensions stored at 4, 25 and 40 ºC over a 60- day period has been studied. Rheological behavior, particle size, a prediction of long-term physical stability, pH and assay of spironolactone by HPLC were assessed at prefixed times. The dissolution profile of each suspension was determined and compared with that of the commercial tablets. A microbiological study of the best formula was also performed. Chemically, the four spironolactone suspensions were stable for 60 days stored at three temperatures; Suspension IV had optimum pH values and the highest recovery percentage. In terms of physical stability, sedimentation occurred in Suspension IV and flotation of spironolactone in Suspensions I, II and III. Suspension III had the highest viscosity and the slowest drug release. Suspension IV was also microbiologically stable for 60 days. In conclusion, Suspension IV had the best properties and the least suitable form was Suspension III, as its high viscosity made it difficult to achieve homogeneous redispersion, and it had the slowest dissolution profile.
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ABSTRACT The objective of this study was to evaluate the chemical and physical attributes of different soil cover in a Oxisol with a strong wavy relief in the Atlantic Forest Biome, in which were selected three watersheds, employed with grazing (watershed P), forest (watershed M) and coffee (watershed C). Deformed and not deformed samples were collected in three depths for physical and chemical characterization. The chemical characteristics of soil in different watershed studies presented low levels of fertility. It was observed an elevation of pH in the soil and contents of Ca2+ and Mg2+ in the watersheds P and C in relation to the watershed M. Due to deforestation and the establishment of agriculture and livestock, there was a decrease in the contents of soil organic matter in the watershed P and C, not altering the physical characteristics of the soil in the watershed P. The implementation of coffee plantation is causing a reduction in the soil quality of watershed C in comparison to the watershed P and M, therefore indicating a need to adequate soil management in this area.
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Several equipments and methodologies have been developed to make available precision agriculture, especially considering the high cost of its implantation and sampling. An interesting possibility is to define management zones aim at dividing producing areas in smaller management zones that could be treated differently, serving as a source of recommendation and analysis. Thus, this trial used physical and chemical properties of soil and yield aiming at the generation of management zones in order to identify whether they can be used as recommendation and analysis. Management zones were generated by the Fuzzy C-Means algorithm and their evaluation was performed by calculating the reduction of variance and performing means tests. The division of the area into two management zones was considered appropriate for the present distinct averages of most soil properties and yield. The used methodology allowed the generation of management zones that can serve as source of recommendation and soil analysis; despite the relative efficiency has shown a reduced variance for all attributes in divisions in the three sub-regions, the ANOVA did not show significative differences among the management zones.
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The aim of this study was to investigate the effects of a 6-month exercise program on cognitive function and blood viscosity in sedentary elderly men. Forty-six healthy inactive men, aged 60–75 years were randomly distributed into a control group (n=23) and an experimental group (n=23). Participants underwent blood analysis and physical and memory evaluation, before and after the 6-month program of physical exercise. The control group was instructed not to alter its everyday activities; the experimental group took part in the fitness program. The program was conducted using a cycle ergometer, 3 times per week on alternate days, with intensity and volume individualized at ventilatory threshold 1. Sessions were continuous and maximum duration was 60 min each. There was significant improvement in memory (21%; P<0.05), decreased blood viscosity (−19%; P<0.05), and higher aerobic capacity (48%; P<0.05) among participants in the experimental group compared with the control group. These data suggest that taking part in an aerobic physical fitness program at an intensity corresponding to ventilatory threshold-1 may be considered a nonmedication alternative to improve physical and cognitive function.
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Strawberries were submitted to freezing after pre-treatments with hydrocolloid and calcium salts (pectin and calcium chloride) at different concentrations, in the attempt to establish a correlation of the effects of these substances and their processing, on the physical and microstructural characteristics of fruits after thawing. Strawberry halves were submitted to impregnation with controlled vacuum pressure of 84.4, 50.5 and 16.6 kPa; comprising pectin at concentrations of 0, 1.5 and 3%; with the addition of calcium chloride at concentrations of 0, 3 and 6%; and glucose at 20%, for 4 hours. Measurements were made of the total soluble solid contents, cellular fluid loss, texture and viscosity of the solution, before and after the freezing/thawing. Images of the tissue cuts during the freezing, in function of time, were taken in an optic microscope coupled to a cold-stage and controlled temperature system, where the reduction of the cellular area was quantified using an image analyzing software. The pectin concentration had an influence on and demonstrated a potential for protection of the frozen tissue samples. The photomicrographs showed that the loss of cellular fluid occurs during the growth of ice formed in the intercellular spaces and it is retarded through treatments with high pectin concentrations.
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Research has noted both physical and psychosocial benefits when children participate in regular physical activity. Recent studies are indicating that there may also be academic benefits and that students may be more efficient learners with participation in physical activity. This study investigated the influence of acute moderate-to-vigorous physical activity on four cognitive functions: planning, attention, simultaneous processing, and successive processing. Three classes (59 students) were each tested twice using a balanced design (intervention, balance, and control groups). It was found that the intervention group had a large increase in planning abiHty (ES = 1.67) when compared to the balance (ES = .80) and control (ES = -.89) groups. On the three remaining cognitive functions, the intervention group showed effect sizes similar to that of the balance and control groups. These results indicate that improved planning after physical activity may playa role in improving student performance.
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Background: The purpose of this study was to examine the relationships between physical activity and healthy eating behaviour with the participant's motives and goals for each health behaviour. Methods: Participants (N 121; 93.2% female) enrolled in commercial weightloss programs at the time of data collection, completed self-reported instruments using a web-based interface that were in accordance with Deci and Ryan's (2002) Self-Determination Theory (SDT). Results: Multiple linear regression models revealed that motivation and goals collectively accounted for between 0.21 to 0.29 percent and 0.03 to 0.16 percent of the variance in physical and healthy eating behaviours in this sample. In general, goals regarding either behaviour did not appear to have strong predictive relationships with each health behaviour beyond the contributions of motives. Discussion: Overall, findings from this study suggest that motives seem to mattermore than goals for both physical activity and healthy eating behaviour in clientele of commercial weight-loss programs. Therefore commercial weight-loss program implementers may want to consider placing more attention on motives I than goals for their clientele when designing weight-loss and weight-maintenance initiatives.
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Les oxydants infusés avec la nutrition parentéral (NP) néonatale induisent une modification du métabolisme des lipides et du glucose, donnant lieu à l’âge adulte à un phénotype de carence énergétique (faible poids, baisse de l’activité physique). L’hypothèse qu’une diète précoce riche en glucose prévient ces symptômes plus tard dans la vie, fut évalué chez le cobaye par un ANOVA en plan factoriel complet à deux facteurs (p < 0:05) : NP du jour 3 à 7, suivit d’une nourriture régulière (chow) (NP+) vs. chow à partir du 3ième jour (NP-), combiné avec une eau de consommation enrichie en glucose (G+) ou non (G-) à partir de la 3ième semaine. Les paramètres suivant ont été mesurés à l’âge de 9 semaine: taux de croissance, activité physique, activité de phosphofructokinase-1 et glucokinase (GK), niveau hépatique de glucose-6-phosphate (G6P), glycogène, pyruvate et potentiel redox du glutathion, poids du foie, glycémie, tolérance au glucose, concentrations hépatiques et plasmatiques en triacylglycérides (TG) et cholestérol. Le groupe G+ (vs. G-) avait un taux de croissance plus bas, une activité de GK et une concentration en G6P plus élevée, et un potentiel redox plus bas (moins oxydé). Le niveau plasmatique de TG était moins élevé dans le groupe NP+ (vs. NP-). Les traitements n’eurent aucun effet sur les autres paramètres. Ces résultats suggèrent qu’indépendamment de la NP, une alimentation riche en glucose stimule la glycolyse et déplace l’état redox vers un statut plus réduit, mais ne surmonte pas les effets de la NP sur le phénotype physique de carence énergétique.
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Cette thèse analyse les négociations interculturelles des Gens du Centre (groupe amazonien multi-ethnique) avec les discours universels de droits humains et de développement mobilisés par l’État colombien. L’analyse se concentre sur le Plan de sauvegarde ethnique Witoto chapitre Leticia (ESP), qui est un des 73 plans formulés et implémentés par l’État colombien pour reconnaître les droits des peuples autochtones en danger par le déplacement forcé causé par les conflits armés internes. J’analyse l’ESP à travers la notion de friction (Tsing, 2005) qui fait référence aux caractéristiques complexes, inégalitaires et changeantes des rencontres contemporaines entre les différences des savoirs locaux et globaux. Mon analyse se base aussi sur des approches foucaldiennes et/ou subalternes de pouvoir comme la recherche anticoloniale et de la décolonisation, les perspectives critiques et contre-hégémoniques des droits humains, le post-développement, et les critiques du féminisme au développement. L’objectif de la thèse est d’analyser les savoirs (concepts de loi, de justice et de développement); les logiques de pensée (pratiques, épistémologies, rôles et espaces pour partager et produire des savoirs); et les relations de pouvoir (formes de leadership, associations, réseaux, et formes d’empowerment et disempowerment) produits et recréés par les Gens du Centre au sein des frictions avec les discours de droits humains et du développement. La thèse introduit comment la région habitée par les Gens du Centre (le Milieu Amazone transfrontalier) a été historiquement connectée aux relations inégalitaires de pouvoir qui influencent les luttes actuelles de ce groupe autochtone pour la reconnaissance de leurs droits à travers l’ESP. L’analyse se base à la fois sur une recherche documentaire et sur deux terrains ethnographiques, réalisés selon une perspective critique et autoréflexive. Ma réflexion méthodologique explore comment la position des chercheurs sur le terrain influence le savoir ethnographique et peut contribuer à la création des relations interculturelles inclusives, flexibles et connectées aux besoins des groupes locaux. La section analytique se concentre sur comment le pouvoir circule simultanément à travers des échelles nationale, régionale et locale dans l’ESP. J’y analyse comment ces formes de pouvoir produisent des sujets individuels et collectifs et s’articulent à des savoirs globaux ou locaux pour donner lieu à de nouvelles formes d’exclusion ou d’émancipation des autochtones déplacés. Les résultats de la recherche suggèrent que les Gens du Centre approchent le discours des droits humains à travers leurs savoirs autochtones sur la « loi de l’origine ». Cette loi établit leur différence culturelle comme étant à la base du processus de reconnaissance de leurs droits comme peuple déplacé. D’ailleurs, les Gens du Centre approprient les discours et les projets de développement à travers la notion d’abondance qui, comprise comme une habileté collective qui connecte la spiritualité, les valeurs culturelles, et les rôles de genre, contribue à assurer l’existence physique et culturelle des groupes autochtones. Ma thèse soutient que, même si ces savoirs et logiques de pensée autochtones sont liés à des inégalités et à formes de pouvoir local, ils peuvent contribuer à des pratiques de droits humains et de développement plurielles, égalitaires et inclusives.
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Contexte: L’arthrite juvénile idiopathique (AJI) est l’une des maladies chroniques auto-immune les plus répandues chez les enfants et est caractérisée par des enflures articulaires (maladie active), de la douleur, de la fatigue et des raideurs matinales pouvant restreindre leur niveau de participation aux activités quotidiennes (par exemple: les loisirs, l’activité physique, la mobilité et les soins personnels) à la maison comme à l’école. Participer aux activités de loisirs et à l’activité physique a des bienfaits au niveau de la santé et du développement de tous les enfants et démontrent aussi des effets positifs qui réduisent les symptômes des maladies chroniques telle l’AJI. Malgré ces bienfaits la participation aux loisirs chez les jeunes avec l’AJI demeure largement sous-étudiée. Objectifs: Cette étude vise à évaluer le niveau de participation aux loisirs et à l’activité physique chez les enfants et les adolescents atteints d’AJI, ainsi qu’à identifier les facteurs liés à la maladie, la personne et l’environnement. Méthodes : L’évaluation du niveau de participation et l’exploration des facteurs associés aux loisirs et à l’activité physique ont été complétés par l’entremise d’une revue systématique de la littérature, l’analyse de données d’un échantillon national représentatif d’enfants canadiens atteints d’arthrite âgés entre 5 et 14 ans (npondéré = 4350), ainsi que l’analyse standardisée du niveau de participation aux loisirs à l’aide du Children’s Assessment of Participation and Enjoyment (n=107) et la mesure objective de l’activité physique par accéléromètre (n=76) auprès d’un échantillon d’enfants (âgés entre 8 et 11 ans ) et d’adolescents (âgés entre 12 et 17 ans) suivis en clinique de rhumatologie à l’hôpital de Montréal pour enfants, Centre Universitaire de Santé McGill. Les résultats cliniques ont été comparés à des données normatives, ainsi qu’à un groupe contrôle sans AJI. Nous avons exploré les facteurs associés avec le niveau de participation aux loisirs et à l’activité physique en utilisant les modèles de régression linéaire multiple et l’analyse hiérarchique. Résultats : Les enfants et les adolescents atteints d’AJI participent à une multitude d’activités de loisirs; cependant ils sont moins souvent impliqués dans des activités physiques et de raffinement en comparaison aux autres types d’activités de loisirs. Ceux avec l’AJI étaient en général moins actifs que leurs pairs sans arthrite et la plupart n’atteignaient pas les recommandations nationales d’activité physique. Les garçons avec l’AJI participent plus souvent à des activités physiques et moins aux activités sociales, de raffinement et de développement de soi en comparaison avec les filles ayant l’AJI. En général, être un garçon, être plus âgé, avoir une meilleure motivation pour participer aux activités de motricité globale, avoir un statut socio-économique plus élevé et être d’origine culturelle canadienne sont associés à un niveau de participation plus élevé aux activités physiques. La préférence pour les activités de raffinement, un niveau d’éducation maternelle plus élevé et être une fille étaient associés à un niveau de participation plus élevé aux activités de raffinement. Conclusion: La participation aux loisirs et à l’activité physique en AJI est un concept complexe et semble surtout être expliqué par des facteurs personnels et environnementaux. L’identification des facteurs associés aux loisirs et à l’activité physique est très importante en AJI puisqu’elle peut permettre aux professionnels de la santé de développer des interventions significatives basées sur les activités préférées des enfants, améliorer l’observance au traitement et promouvoir des habitudes de vie saine.
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The objective of the preset work is to develop optical fiber sensors for various physical and chemical parameters. As a part of this we initially investigated trace analysis of silica, ammonia, iron and phosphate in water. For this purpose the author has implemented a dual wavelength probing scheme which has many advantages over conventional evanescent wave sensors. Dual wavelength probing makes the design more reliable and repeatable and this design makes the sensor employable for concentration, chemical content, adulteration level, monitoring and control in industries or any such needy environments. Use of low cost components makes the system cost effective and simple. The Dual wavelength probing scheme is employed for the trace analysis of silica, iron, phosphate, and ammonia in water. Such sensors can be employed for the steam and water quality analysers in power plants. Few samples from a power plant are collected and checked the performance of developed system for practical applications.