989 resultados para dubbelexamen, double degree, tuplatutkinto, motivation, universitetsstuderande
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Concrete curing is closely related to cement hydration, microstructure development, and concrete performance. Application of a liquid membrane-forming curing compound is among the most widely used curing methods for concrete pavements and bridge decks. Curing compounds are economical, easy to apply, and maintenance free. However, limited research has been done to investigate the effectiveness of different curing compounds and their application technologies. No reliable standard testing method is available to evaluate the effectiveness of curing, especially of the field concrete curing. The present research investigates the effects of curing compound materials and application technologies on concrete properties, especially on the properties of surface concrete. This report presents a literature review of curing technology, with an emphasis on curing compounds, and the experimental results from the first part of this research—lab investigation. In the lab investigation, three curing compounds were selected and applied to mortar specimens at three different times after casting. Two application methods, single- and double-layer applications, were employed. Moisture content, conductivity, sorptivity, and degree of hydration were measured at different depths of the specimens. Flexural and compressive strength of the specimens were also tested. Statistical analysis was conducted to examine the relationships between these material properties. The research results indicate that application of a curing compound significantly increased moisture content and degree of cement hydration and reduced sorptivity of the near-surface-area concrete. For given concrete materials and mix proportions, optimal application time of curing compounds depended primarily upon the weather condition. If a sufficient amount of a high-efficiency-index curing compound was uniformly applied, no double-layer application was necessary. Among all test methods applied, the sorptivity test is the most sensitive one to provide good indication for the subtle changes in microstructure of the near-surface-area concrete caused by different curing materials and application methods. Sorptivity measurement has a close relation with moisture content and degree of hydration. The research results have established a baseline for and provided insight into the further development of testing procedures for evaluation of curing compounds in field. Recommendations are provided for further field study.
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1. We compared the changes in binding energy generated by two mutations that shift in divergent directions the constitutive activity of the human beta(2) adrenergic receptor (beta(2)AR). 2. A constitutively activating mutant (CAM) and the double alanine replacement (AA mutant) of catechol-binding serines (S204A, S207A) in helix 5 were stably expressed in CHO cell lines, and used to measure the binding affinities of more than 40 adrenergic ligands. Moreover, the efficacy of the same group of compounds was determined as intrinsic activity for maximal adenylyl cyclase stimulation in wild-type beta(2)AR. 3. Although the two mutations had opposite effects on ligand affinity, the extents of change were in both cases largely correlated with the degree of ligand efficacy. This was particularly evident if the extra loss of binding energy due to hydrogen bond deletion in the AA mutant was taken into account. Thus the data demonstrate that there is an overall linkage between the configuration of the binding pocket and the intrinsic equilibrium between active and inactive receptor forms. 4. We also found that AA mutation-induced affinity changes for catecholamine congeners gradually lacking ethanolamine substituents were linearly correlated to the loss of affinity that such modifications of the ligand cause for wild-type receptor. This indicates that the strength of bonds between catechol ring and helix 5 is critically dependent on the rest of interactions of the beta-ethanolamine tail with other residues of the beta(2)-AR binding pocket.
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In this chapter, after pointing out the different logics that lie behind the familiar ideas of democracy and federalism, I have dealt with the case of plurinational federal democracies. Having put forward a double criterion of an empirical nature with which to differentiate between the existence of minority nations within plurinational democracies (section 2), I suggest three theoretical criteria for the political accommodation of these democracies. In the following section, I show the agonistic nature of the normative discussion of the political accommodation of this kind of democracies, which bring monist and pluralist versions of the demos of the polity into conflict (section 3.1), as well as a number of conclusions which are the result of a comparative study of 19 federal and regional democracies using four analytical axes: the uninational/plurinational axis; the unitarianism-federalism axis; the centralisation-decentralisation axis; and the symmetry-asymmetry axis (section 3.2). This analysis reveals shortcomings in the constitutional recognition of national pluralism in federal and regional cases with a large number of federated units/regions with political autonomy; a lower degree of constitutional federalism and a greater asymmetry in the federated entities or regions of plurinational democracies. It also reveals difficulties to establish clear formulas in these democracies in order to encourage a “federalism of trust” based on the participation and protection of national minorities in the shared government of plurinational federations/regional states. Actually, there is a federal deficit in this kind polities according to normative liberal-democratic patterns and to what comparative analysis show. Finally, this chapter advocates the need for a greater normative and institutional refinement in plurinational federal democracies. In order to achieve this, it is necessary to introduce a deeper form of “ethical” pluralism -which displays normative agonistic trends, as well as a more “confederal/asymmetrical” perspective, congruent with the national pluralism of these kind of polities.
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OBJECTIVE: To assess the effectiveness of pulsed signal therapy in the treatment of knee osteoarthritis (Kellgren II or III). METHODS: A randomized, double-blind controlled clinical trial. The first 95 patients sent to the clinic with knee osteo-arthritis were selected and randomized into treatment with pulsed signal therapy or conventional physiotherapy. Assessment included recording of usual demographic data, pertinent history, baseline medication and radiographs. Clinical evaluation was made at baseline, 6 weeks and 6 months after the end of treatment by the same blinded doctor. At each follow-up time, the patient was asked to complete a visual analogue pain scale and a Lequesne score. The doctor recorded the degree of pain on motion and the ability to move the affected knee. RESULTS: Both treatments resulted in significant improvements in pain and physical function. A statistical difference was observed only for activities of daily living, where the physiotherapy was more efficient (p<0.03). The cost of treatment with pulsed signal therapy was significantly higher, double the treatment cost of conventional physiotherapy. CONCLUSION: Like physiotherapy, pulsed signal therapy has improved the clinical state of treated patients but with no significant statistical difference. Pulsed signal therapy is, however, more expensive.
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Reproductive isolation between lineages is expected to accumulate with divergence time, but the time taken to speciate may strongly vary between different groups of organisms. In anuran amphibians, laboratory crosses can still produce viable hybrid offspring >20 My after separation, but the speed of speciation in closely related anuran lineages under natural conditions is poorly studied. Palearctic green toads (Bufo viridis subgroup) offer an excellent system to address this question, comprising several lineages that arose at different times and form secondary contact zones. Using mitochondrial and nuclear markers, we previously demonstrated that in Sicily, B. siculus and B. balearicus developed advanced reproductive isolation after Plio-Pleistocene divergence (2.6 My, 3.3-1.9), with limited historic mtDNA introgression, scarce nuclear admixture, but low, if any, current gene flow. Here, we study genetic interactions between younger lineages of early Pleistocene divergence (1.9 My, 2.5-1.3) in northeastern Italy (B. balearicus, B. viridis). We find significantly more, asymmetric nuclear and wider, differential mtDNA introgression. The population structure seems to be molded by geographic distance and barriers (rivers), much more than by intrinsic genomic incompatibilities. These differences of hybridization between zones may be partly explained by differences in the duration of previous isolation. Scattered research on other anurans suggests that wide hybrid zones with strong introgression may develop when secondary contacts occur <2 My after divergence, whereas narrower zones with restricted gene flow form when divergence exceeds 3 My. Our study strengthens support for this rule of thumb by comparing lineages with different divergence times within the same radiation.
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Zeta potential is a physico-chemical parameter of particular importance to describe sorption of contaminants at the surface of gas bubbles. Nevertheless, the interpretation of electrophoretic mobilities of gas bubbles is complex. This is due to the specific behavior of the gas at interface and to the excess of electrical charge at interface, which is responsible for surface conductivity. We developed a surface complexation model based on the presence of negative surface sites because the balance of accepting and donating hydrogen bonds is broken at interface. By considering protons adsorbed on these sites followed by a diffuse layer, the electrical potential at the head-end of the diffuse layer is computed and considered to be equal to the zeta potential. The predicted zeta potential values are in very good agreement with the experimental data of H-2 bubbles for a broad range of pH and NaCl concentrations. This implies that the shear plane is located at the head-end of the diffuse layer, contradicting the assumption of the presence of a stagnant diffuse layer at the gas/water interface. Our model also successfully predicts the surface tension of air bubbles in a KCl solution. (c) 2012 Elsevier Inc. All rights reserved.
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This paper argues that low-stakes test scores, available in surveys, may be partially determined by test-taking motivation, which is associated with personality traits but not with cognitive ability. Therefore, such test score distributions may not be informative regarding cognitive ability distributions. Moreover, correlations, found in survey data, between high test scores and economic success may be partially caused by favorable personality traits. To demonstrate these points, I use the coding speed test that was administered without incentives to National Longitudinal Survey of Youth 1979 (NLSY) participants. I suggest that due to its simplicity its scores may especially depend on individuals' test-taking motivation. I show that controlling for conventional measures of cognitive skills, the coding speed scores are correlated with future earnings of male NLSY participants. Moreover, the coding speed scores of highly motivated, though less educated, population (potential enlists to the armed forces) are higher than NLSY participants' scores. I then use controlled experiments to show that when no performance-based incentives are provided, participants' characteristics, but not their cognitive skills, affect effort invested in the coding speed test. Thus, participants with the same ability (measured by their scores on an incentivized test) have significantly different scores on tests without performance- based incentives.
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Jacobins de la rue Saint-Jacques.
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Guided by a modified information-motivation-behavioral skills model, this study identified predictors of condom use among heterosexual people living with HIV with their steady partners. Consecutive patients at 14 European HIV outpatient clinics received an anonymous, standardized, self-administered questionnaire between March and December 2007. Data were analyzed using descriptive statistics and two-step backward elimination regression analyses stratified by gender. The survey included 651 participants (n = 364, 56% women; n = 287, 44%). Mean age was 39 years for women and 43 years for men. Most had acquired HIV sexually and more than half were in a serodiscordant relationship. Sixty-three percent (n = 229) of women and 59% of men (n = 169) reported at least one sexual encounter with a steady partner 6 months prior to the survey. Fifty-one percent (n = 116) of women and 59% of men (n = 99) used condoms consistently with that partner. In both genders, condom use was positively associated with subjective norm conducive to condom use, and self-efficacy to use condoms. Having a partner whose HIV status was positive or unknown reduced condom use. In men, higher education and knowledge about condom use additionally increased condom use, while the use of erectile-enhancing medication decreased it. For women, HIV disclosure to partners additionally reduced the likelihood of condom use. Positive attitudes to condom use and subjective norm increased self-efficacy in both genders, however, a number of gender-related differences appeared to influence self-efficacy. Service providers should pay attention to the identified predictors of condom use and adopt comprehensive and gender-related approaches for preventive interventions with people living with HIV.
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How people choose to live depends on a variety of social and economic circumstances. Single family dwellings, extended family compounds, and communal apartment blocks are all forms of residential architecture that have ancient roots and occur in every culture. Each form both reflects and affects the living styles of the people who reside there. The double house, which shelters two families in units separated by a wall or floor, balances the convenience of an apartment with the psychological comforts of a home. During the mid to late nineteenth and early twentieth centuries in the United States, the double house was hugely popular in some cities, such as Minneapolis and Milwaukee, but only a minimal presence in Des Moines
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Catecholamines and alpha(1)-adrenergic receptors (alpha(1)-ARs) cause cardiac hypertrophy in cultured myocytes and transgenic mice, but heart size is normal in single KOs of the main alpha(1)-AR subtypes, alpha(1A/C) and alpha(1B). Here we tested whether alpha(1)-ARs are required for developmental cardiac hypertrophy by generating alpha(1A/C) and alpha(1B) double KO (ABKO) mice, which had no cardiac alpha(1)-AR binding. In male ABKO mice, heart growth after weaning was 40% less than in WT, and the smaller heart was due to smaller myocytes. Body and other organ weights were unchanged, indicating a specific effect on the heart. Blood pressure in ABKO mice was the same as in WT, showing that the smaller heart was not due to decreased load. Contractile function was normal by echocardiography in awake mice, but the smaller heart and a slower heart rate reduced cardiac output. alpha(1)-AR stimulation did not activate extracellular signal-regulated kinase (Erk) and downstream kinases in ABKO myocytes, and basal Erk activity was lower in the intact ABKO heart. In female ABKO mice, heart size was normal, even after ovariectomy. Male ABKO mice had reduced exercise capacity and increased mortality with pressure overload. Thus, alpha(1)-ARs in male mice are required for the physiological hypertrophy of normal postnatal cardiac development and for an adaptive response to cardiac stress.