976 resultados para CHROMOSOMAL GAINS


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The provision of advisory support to small firms is almost ubiquitous in OECD countries, although it is organised in different ways and is justified on slightly different grounds. In England publicly supported advisory services are provided through the Business Link (BL) network. Here, we consider two questions: what sort of companies receive advisory support from BL; and, what types of firms benefit most from that support? Our analysis is based on a telephone survey of 2000 firms, around half of which had received intensive assistance from BL between April and October 2003. Probit analysis suggests that the probability of receiving assistance was greater among younger businesses, those with larger numbers of directors in the firm, and those with more gender diversity among the firm's leadership team. Our business-growth models suggest that BL intensive assistance was having a positive effect on employment growth in 2003. BL had a positive but insignificant impact on sales growth over the period. Employment growth effects tend to be larger where firms have a management and organisational structure, which is more conducive to absorbing and making use of external advice. The analysis suggests that BL might increase its impact through targeting these larger, more export-orientated, businesses. Employment growth effects differ little, however, depending on either the ethnic or the gender diversity of the leadership team.

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There is a growing literature explaining foreign direct investment flows in terms of 'technology sourcing', whereby multinational firms invest in certain locations not to exploit their firm-specific assets in the host environment, but to access technology that is generated by host country firms. However, it is far from clear whether the literature has found significant evidence of such activity beyond a few isolated examples. This paper extends this work by allowing for the possibility of multinational enterprises (MNEs) sourcing technology not only from host country firms but also from each other within a host economy. The paper demonstrates that MNEs in the UK do indeed appropriate spillovers both from indigenous firms and from other foreign investors, but that there are also significant competition effects that act to reduce productivity in certain industries. The paper also explores which countries' affiliates gain most from technology sourcing in the UK, and which generate the greatest spillovers within the foreign-owned sector. © Scottish Economic Society 2005.

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The chromosomal ß-lactamase of Pseudomonas aeruginosa SAlconst (a derepressed laboratory strain) was isolated and purified. Two peaks of activity were observed on gel permeation chromatography (one major peak mol. wt. 45 kD and one minor peak of 54 kD). Preparations from 12 clinical derepressed strains showed identical results. Chromosomal ß-lactamase production in both normal and derepressed P. aeruginosa strains was induced both by iron restricted growth conditions and by penicillin G. The majority of the enzyme (80-90%) was found in the periplasm and cytoplasm but a significant amount (2-20%) was associated with the outer membrane (OM). The growth conditions did not affect the distribution of the enzyme between subcellular fractions although higher activity was found in the cells grown under iron limitation and/ or in the presence of ß-lactams. The penicillanate sulphone inhibitor, tazobactam, displayed irreversible kinetics whilst cloxacillin, cefotaxime, ampicillin and penicillin G were all competitive inhibitors of the enzyme. Similar results were obtained for the Enterobacter cloacae P99 [ß-lactamase, but tazobactam displayed a non-classical kinetic pattern for the Staphylococcus aureus PC1 ß-lactamase. The residues involved in ß-lactam hydrolysis by the P aeruginosa SAlconst enzyme were detennined by affinity labelling with tazobactam. A tryptic digestion fragment of the inhibited enzyme contained the amino acids D, T, S, E, P, G, A, C, V, M, I, Y, F, H, K, R. This suggests the involvement of the conserved SVSK, DAE and KTG motifs found in all penicillin sensitive proteins. A model of the 3-D structure of the active site of the P aeruginosa SAlconst chromosomal ß-!actamase was constructed from the published amino acid sequence of P aeruginosa chromosomal ß-lactamase and the a-carbon coordinates of the S. aureus PCI ß-lactamase by homology modelling and energy minimisation. The crystal structure of tazobactam was determined and energy minimised. Computer graphics docking identified Ser 72 as a possible residue involved in a secondary attack on the C5 position of tazobactam after initial ß-lactam hydrolysis by serine 70. The enhanced activity of tazobactam over sulbactam might be explained by the triazole substituent which might participate in favourable hydrogen bonding between N3 and active site residues.

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In this paper we examine the impact that the new trading system SETSmm had on market quality measures such as firm value, liquidity and pricing efficiency. This system was introduced for mid-cap securities on the London Stock Exchange in 2003. We show that there is a small SETSmm return premium associated with the announcement that securities are to migrate to the new trading system. We find that migration to SETSmm also improves liquidity and pricing efficiency and these changes are related to the return premium. We also find that these gains are stronger for firms with high pre SETSmm liquidity and weaker for firms with low SETSmm liquidity.

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Background Abnormalities in incentive decision making, typically assessed using the Iowa Gambling Task (IGT), have been reported in both schizophrenia (SZ) and bipolar disorder (BD). We applied the Expectancy-Valence (E-V) model to determine whether motivational, cognitive and response selection component processes of IGT performance are differentially affected in SZ and BD. Method Performance on the IGT was assessed in 280 individuals comprising 70 remitted patients with SZ, 70 remitted patients with BD and 140 age-, sex-and IQ-matched healthy individuals. Based on the E-V model, we extracted three parameters, 'attention to gains or loses', 'expectancy learning' and 'response consistency', that respectively reflect motivational, cognitive and response selection influences on IGT performance. Results Both patient groups underperformed in the IGT compared to healthy individuals. However, the source of these deficits was diagnosis specific. Associative learning underlying the representation of expectancies was disrupted in SZ whereas BD was associated with increased incentive salience of gains. These findings were not attributable to non-specific effects of sex, IQ, psychopathology or medication. Conclusions Our results point to dissociable processes underlying abnormal incentive decision making in BD and SZ that could potentially be mapped to different neural circuits. © 2012 Cambridge University Press.

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In this paper we examine the impact that the new trading system SETSmm had on market quality measures such as firm value, liquidity and pricing efficiency. This system was introduced for mid-cap securities on the London Stock Exchange in 2003. We show that there is a small SETSmm return premium associated with the announcement that securities are to migrate to the new trading system. We find that migration to SETSmm also improves liquidity and pricing efficiency and these changes are related to the return premium. We also find that these gains are stronger for firms with high pre SETSmm liquidity and weaker for firms with low SETSmm liquidity. © 2013 John Wiley & Sons Ltd.

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The purpose of this research was to determine whether initial developmental delay, site of intervention, frequency of intervention, age of the child, socio-economic status (SES), gender and ethnicity significantly predict developmental gains in a group of children enrolled in an early intervention setting. The records of 134 children enrolled in an inner-city program in Miami, Florida were reviewed for inclusion in this study. ^ Demographic variables, site placement and treatment frequencies were collected during a retrospective chart review. Level of delay was expressed using the developmental quotient and developmental gain was calculated using the mean gain on age equivalent scores or developmental tests. A multiple regression analysis was performed to determine which of the above variables significantly predicted developmental gains. Multivariate analysis compared developmental gains for all the developmental domains based on intervention site (center versus home-based) while controlling for developmental delay. ^ Children made greater developmental gains if they had higher developmental quotients and if they were younger at the time services were initiated. Frequency of intervention significantly improved developmental outcomes in children attending center-based programs. Children attending center-based programs also made significantly greater gains in gross motor skills compared to children attending home-based programs. ^ These findings emphasize the importance of early screening and referral of children with developmental delay and adjusting intervention for the child's developmental quotient. Children should receive intense treatment to maximize results. Decisions regarding program placement should be individualized according to the child's unique developmental pattern. Policy and program decisions affecting the curriculum of a child in early intervention need to reflect these multivariate considerations. ^

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Black students, in general, are underserved academically (Darling-Hammond, 2000; Townsend, 2002) and overrepresented in special education (Donovan & Cross, 2002). Black students with disabilities are further overrepresented in more restrictive educational environments (Skiba, Poloni-Staudinger, Gallini, Simmons & Feggins-Azziz, 2006). Although the National Longitudinal Transition Study 2 (NLTS2) revealed that the academic performance of students with learning disabilities is positively related to the percentage of courses taken in the general education setting (Newman, 2006), the research specifically on placement of Black students with disabilities, particularly at the secondary level, as it relates to academic achievement is lacking. While previous studies have sought to determine which placement is better for students with disabilities, no study was found that specifically examined the impact of placement specific to Black students with specific learning disabilities (SLD) in urban settings (Fore, III, Hagan-Burke, Burke, Boon & Smith, 2008; Rea, McLaughlin & Walther-Thomas, 2002). This study examined educational placement, instructional best practices, and achievement gains of Black students with SLD in urban secondary settings using an ex post facto research design. Achievement, placement, and demographic data were collected and analyzed on approximately 314 Black eighth grade students with SLD. The Teacher Instructional Practices Survey was developed and used to collect and analyze data from the teachers of 78 of these students as it relates to instructional best practices. Results indicate no significant difference in reading but a significant difference in math gains of students served in inclusive settings as compared to resource settings with a small effect size. Also, no significant relationship was found between achievement gains and the reported use of instructional best practices. However, there was a relationship between educational placement and the use of instructional best practices. The results implied that there is a need for training with both general and special education teachers on instructional best practices for SWD and that there should be certain IEP team considerations when making placement decisions for this population of students with disabilities. It is recommended that future research in this area include classroom observations and factors other than test scores to measure growth in achievement.

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This study was conducted to determine if the use of the technology known as Classroom Performance System (CPS), specifically referred to as "Clickers", improves the learning gains of students enrolled in a biology course for science majors. CPS is one of a group of developing technologies adapted for providing feedback in the classroom using a learner-centered approach. It supports and facilitates discussion among students and between them and teachers, and provides for participation by passive students. Advocates, influenced by constructivist theories, claim increased academic achievement. In science teaching, the results have been mixed, but there is some evidence of improvements in conceptual understanding. The study employed a pretest-posttest, non-equivalent groups experimental design. The sample consisted of 226 participants in six sections of a college biology course at a large community college in South Florida with two instructors trained in the use of clickers. Each instructor randomly selected their sections into CPS (treatment) and non-CPS (control) groups. All participants filled out a survey that included demographic data at the beginning of the semester. The treatment group used clicker questions throughout, with discussions as necessary, whereas the control groups answered the same questions as quizzes, similarly engaging in discussion where necessary. The learning gains were assessed on a pre/post-test basis. The average learning gains, defined as the actual gain divided by the possible gain, were slightly better in the treatment group than in the control group, but the difference was statistically non-significant. An Analysis of Covariance (ANCOVA) statistic with pretest scores as the covariate was conducted to test for significant differences between the treatment and control groups on the posttest. A second ANCOVA was used to determine the significance of differences between the treatment and control groups on the posttest scores, after controlling for sex, GPA, academic status, experience with clickers, and instructional style. The results indicated a small increase in learning gains but these were not statistically significant. The data did not support an increase in learning based on the use of the CPS technology. This study adds to the body of research that questions whether CPS technology merits classroom adaptation.

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Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.