929 resultados para Writers and readers formation


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Desegregation of social and public spaces was the most visible result of the Civil Rights Movement. After 1960, the integration of schools in Mississippi became a source of conflict. The social change of Civil Rights attacked the social order of White Resistance that supported the state superstructure. The public schools were a place for the discovery of identity for Blacks. The integrated on of the schools caused many Whites to leave rather than be integrated with Blacks. Desegregation of schools was also a slow process because the local and state government could not enforce the decisions of the US Courts, leading Blacks to realize their place in American society could only be secured through individual action. ^ This work explains the role of schooling during the integration of the Holly Springs Separate School System. The process of forging a new identity by local Blacks is examined against the forces of social change and resistance. I addition, this work examines the perils for the Blacks as they faced the uncertainty of change in the crucial Civil Rights years between 1964 and 1974. ^ This work analyzes how the Black community dealt with the problems triggered by the desegregation of the school system in Holly Springs, of a constructed social condition, a psychological state of being, the realities of racism and segregation, and the change and resistance between the individual and the collective. It is based on six months of field work investigation. Although the schools were a crucial aspect of community life for Blacks and Whites, Blacks did form their identity in them. Other institutions, such churches were more crucial. Second, the aspect of politeness and belief in law made the experience in Holly Springs unique to that place, and thus, warrants further study to determine its place within the Civil Rights Movement. Finally, while the political and economic control of Holly Springs remained with Whites, desegregation led to the resegregation of the public schools: as Whites left to private schools. ^

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The Balmis expedition, sent to America by the Spanish monarch Charles IV in 1803, was a watershed in the history of Medicine as it made smallpox vaccination available for the first time, effectively prevented the disease from spreading, and saved thousands of lives. Immunization required complex administrative measures and political decisions including the creation of Vaccination Boards, all of which involved different sectors of Spanish American society. This dissertation argues that at the beginning of the nineteenth century the Spanish American colonial state had reached some level of maturity and cohesion that made it capable of executing this complex project in public health. The significance of this mobilization and the every-day experience in implementing this new public health measure is the center of this work. It is situated geographically in Venezuela and Cuba, entities which took different evolutionary paths in the nineteenth century. The organization and functioning of Vaccination Boards in these two areas are used to illustrate the state formation process, and sharp political differences in this critical period.

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This dissertation explores how economic, organizational, and personal factors affect self-employment transitions, occupational decisions, and firm formation activities of individuals at different positions in the skill distribution. The first essay of my dissertation studies how local unemployment rates differentially affect entry into self-employment by individuals at different places in the skill distribution. The empirical results show a positive correlation between local unemployment rates and entry into self-employment for low-ability workers, but not for high-ability workers. Including employer size to eliminate possible distortions showed that the positive association between unemployment and self-employment among low-ability workers is in fact driven by the small firm effect. Controlling for firm size yields a negative association between unemployment and self-employment among high-ability workers. Effects of organizational capital, human capital and physical capital, on the firm formation activities of people at distinct skill levels depend on the type of the industry which is chosen for the new firm. Two types of industries, capital-intensive and ability-intensive, are utilized to explore this hypothesis in the second essay. A capital-intensive industry requires more physical investment, and consequently more funds, whereas, an ability-intensive industry requires more human capital. It is shown that high human capital requirements are associated with higher earnings among the most able individuals, and therefore makes them more likely to found firms in an ability-intensive industry. Wealthy people are more likely to establish both capital-intensive and ability-intensive firms, even though the amount of funds necessary for two industry types differs. Moreover, entry into both industries is predicted to happen later in life due to the removal of entry barriers constituted by required investment spending using savings when old. Empirical mixed results are observed. The third essay investigates earning differentials between future entrepreneurs and their non-entrepreneurial colleagues. Results show that high-ability firm-owners in an ability-intensive industry were earning more than those that remained in wage-work, whereas, low-ability firm-owners in a capital-intensive industry were earning less than those remaining in paid-work.

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Pseudomonas aeruginosa is an opportunistic pathogen found in a wide variety of environments. It is one of the leading causes of morbidity and mortality in cystic fibrosis patients, and one of the main sources of nosocomial infections in the United States. One of the most prominent features of this pathogen is its wide resistance to antibiotics. P. aeruginosa employs a variety of mechanisms including efflux pumps and the expression of B-lactamases to overcome antibiotic treatment. Two chromosomally encoded lactamases, ampC and poxB, have been identified in P. aeruginosa. Sequence analyses have shown the presence of a two-component system (TCS) called MifSR (MifS-Sensor and MifR-Response Regulator), immediately upstream of the poxAB operon. It is hypothesized that the MifSR TCS is involved in B-lactam resistance via the regulation of poxB. Recently, the response regulator MifR has been reported to play a crucial role in biofilm formation, a major characteristic of chronic infections and increased antibiotic resistance. In this study, mifR and mifSR deletion mutants were constructed, and compared to the wild type parent strain PAOl for differences in growth and B-lactam sensitivity. Results obtained thus far indicate that mifR and mifSR are not essential for growth, and do not confer B-lactam resistance under the conditions tested. This study is significant because biofilm formation and antibiotic resistance are two hallmarks of P. aeruginosa infections, and finding a link between these two may lead to the development of improved treatment strategies.

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College students have diverse ways of expressing their spirituality. The purpose of this review is to examine and critique the research used to study college students’ spiritual and religious formation. Implications for faculty, student affairs professionals, and ministers doing research on spiritual formation in higher education are discussed.

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This thesis describes a study conducted to develop and refine a measure, the Social Institutions Rating (SIR), a group administered, self-report measure of institutional attributes and characteristics. This thesis reports data on the psychometric properties of the SIR. Exploratory analyses are reported investigating the empirical effects of social institutions on identity formation within two ethnic/cultural groups, Euroamericans and Hispanics. Based on previous studies with ethnic minorities, a directional hypothesis was tested. The hypothesis that subjects in the Euroamerican sample have a higher identity status than the Hispanic sample for three identity domains (personal, interpersonal, and world view) was not confirmed. The hypothesis that subjects in the Euroamerican sample would score higher on identity satisfaction and lower on identity dissatisfaction than the Hispanic sample for nine content areas of identity was partially supported but in the opposite direction. Hispanics reported higher satisfaction on sense of self and religious issues than Euroamericans.

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We present the essential features of the dissipative parametric instability, in the universal complex Ginzburg- Landau equation. Dissipative parametric instability is excited through a parametric modulation of frequency dependent losses in a zig-zag fashion in the spectral domain. Such damping is introduced respectively for spectral components in the +ΔF and in the -ΔF region in alternating fashion, where F can represent wavenumber or temporal frequency depending on the applications. Such a spectral modulation can destabilize the homogeneous stationary solution of the system leading to growth of spectral sidebands and to the consequent pattern formation: both stable and unstable patterns in one- and in two-dimensional systems can be excited. The dissipative parametric instability provides an useful and interesting tool for the control of pattern formation in nonlinear optical systems with potentially interesting applications in technological applications, like the design of mode- locked lasers emitting pulse trains with tunable repetition rate; but it could also find realizations in nanophotonics circuits or in dissipative polaritonic Bose-Einstein condensates.

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Germanium (Ge) nanowires are of current research interest for high speed nanoelectronic devices due to the lower band gap and high carrier mobility compatible with high K-dielectrics and larger excitonic Bohr radius ensuing a more pronounced quantum confinement effect [1-6]. A general way for the growth of Ge nanowires is to use liquid or a solid growth promoters in a bottom-up approach which allow control of the aspect ratio, diameter, and structure of 1D crystals via external parameters, such as precursor feedstock, temperature, operating pressure, precursor flow rate etc [3, 7-11]. The Solid-phase seeding is preferred for more control processing of the nanomaterials and potential suppression of the unintentional incorporation of high dopant concentrations in semiconductor nanowires and unrequired compositional tailing of the seed-nanowire interface [2, 5, 9, 12]. There are therefore distinct features of the solid phase seeding mechanism that potentially offer opportunities for the controlled processing of nanomaterials with new physical properties. A superior control over the growth kinetics of nanowires could be achieved by controlling the inherent growth constraints instead of external parameters which always account for instrumental inaccuracy. The high dopant concentrations in semiconductor nanowires can result from unintentional incorporation of atoms from the metal seed material, as described for the Al catalyzed VLS growth of Si nanowires [13] which can in turn be depressed by solid-phase seeding. In addition, the creation of very sharp interfaces between group IV semiconductor segments has been achieved by solid seeds [14], whereas the traditionally used liquid Au particles often leads to compositional tailing of the interface [15] . Korgel et al. also described the superior size retention of metal seeds in a SFSS nanowire growth process, when compared to a SFLS process using Au colloids [12]. Here in this work we have used silver and alloy seed particle with different compositions to manipulate the growth of nanowires in sub-eutectic regime. The solid seeding approach also gives an opportunity to influence the crystallinity of the nanowires independent of the substrate. Taking advantage of the readily formation of stacking faults in metal nanoparticles, lamellar twins in nanowires could be formed.

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In this paper, we use density functional theory corrected for on-site Coulomb interactions (DFT + U) and hybrid DFT (HSE06 functional) to study the defects formed when the ceria (110) surface is doped with a series of trivalent dopants, namely, Al3+, Sc3+, Y3+, and In 3+. Using the hybrid DFT HSE06 exchange-correlation functional as a benchmark, we show that doping the (110) surface with a single trivalent ion leads to formation of a localized MCe / + O O • (M = the 3+ dopant), O- hole state, confirming the description found with DFT + U. We use DFT + U to investigate the energetics of dopant compensation through formation of the 2MCe ′ +VO ̈ defect, that is, compensation of two dopants with an oxygen vacancy. In conjunction with earlier work on La-doped CeO2, we find that the stability of the compensating anion vacancy depends on the dopant ionic radius. For Al3+, which has the smallest ionic radius, and Sc3+ and In3+, with intermediate ionic radii, formation of a compensating oxygen vacancy is stable. On the other hand, the Y3+ dopant, with an ionic radius close to that of Ce4+, shows a positive anion vacancy formation energy, as does La3+, which is larger than Ce4+ (J. Phys.: Condens. Matter 2010, 20, 135004). When considering the resulting electronic structure, in Al3+ doping, oxygen hole compensation is found. However, Sc 3+, In3+, and Y3+ show the formation of a reduced Ce3+ cation and an uncompensated oxygen hole, similar to La3+. These results suggest that the ionic radius of trivalent dopants strongly influences the final defect formed when doping ceria with 3+ cations. In light of these findings, experimental investigations of these systems will be welcome.

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Although anthropogenic infuences such as global warming, overfishing, and eutrophication may contribute to jellyfish blooms, little is known about the effects of ocean acidification on jellyfish. Most medusae form statoliths of calcium sulfate hemihydrate that are components of their balance organs (statocysts). This study was designed to test the effects of pH (7.9, within the average current range, 7.5, expected by 2100, and 7.2, expected by 2300) combined with two temperatures (9 and 15°C) on asexual reproduction and statolith formation of the moon jellyfish, Aurelia labiata. Polyp survival was 100% after 122 d in seawater in all six temperature and pH combinations. Because few polyps at 9°C strobilated, and temperature effects on budding were consistent with published results, we did not analyze data from those three treatments further. At 15°C, there were no significant effects of pH on the numbers of ephyrae or buds produced per polyp or on the numbers of statoliths per statocyst; however, statolith size was signi?cantly smaller in ephyrae released from polyps reared at low pH. Our results indicate that A. labiata polyps are quite tolerant of low pH, surviving and reproducing asexually even at the lowest tested pH; however, the effects of small statoliths on ephyra fitness are unknown. Future research on the behavior of ephyrae with small statoliths would further our understanding of how ocean acidi?cation may affect jellyfish survival in nature.

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Postharvest treatments with nano-silver (NS) alleviate bacteria-related stem blockage of some cut flowers to extend their longevity. Gladiolus (Gladiolus hybridus) is a commercially important cut flower species. For the first time, the effects of NS pulses on cut gladiolus ‘Eerde’ spikes were investigated towards reducing bacterial colonization of and biofilm formation on their stems. As compared with a deionized water (DIW) control, pulse treatments with NS at 10, 25 and 50 mg L−1 for 24 h significantly (P ≤ 0.05) prolonged the vase life of cut gladiolus spikes moved into vases containing DIW. The NS treatments enhanced floret ‘opening rate’ and ‘daily ornamental value’. Although there were no significant differences among NS treatments, a 25 mg L−1 NS pulse treatment tended to give the longest vase life and the best ‘display quality’. All NS pulse treatments significantly improved water uptake by and reduced water loss from flowering spikes, thereby delaying the loss of water balance and maintaining relative fresh weight. Fifty (50) mg L−1 NS pulse-treated cut gladiolus spikes tended to exhibit the most water uptake and highest water balance over the vase period. However, there was no significant difference between 25 and 50 mg L−1 NS pulse treatments. Observations of stem-end bacterial proliferation during the vase period on cut gladiolus spikes either with or without NS pulse treatments were performed by confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). As compared to the control treatment, they revealed that the 25 mg L−1 NS pulse treatment effectively inhibited bacterial colonization and biofilm formation on the stem-end cut surface and in the xylem vessels, respectively. In vitro culture of the bacterial microflora and analysis of biofilm architecture using CLSM revealed that NS treatment restricted bacterial biofilm formation. After static culture for 24 h at 35 °C with 25 mg L−1 NS in the medium, no biofilm form or structure was evident. Rather, only limited bacterial cell number and scanty extracellular polysaccharide (EPS) material were observed. In contrast, mature bacterial biofilm architecture comprised of abundant bacteria interwoven with EPS formed in the absence of NS.