975 resultados para FREE ABELIAN-GROUP
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PURPOSE: This article reports the overall survival, failure-free survival, local failure, and late radiation toxicity of a phase II trial of preoperative radiotherapy with continuous infusion 5-fluorouracil for rectal cancer after a minimum 3.5 years of follow-up. METHODS: Eligible patients were those with newly diagnosed localized adenocarcinoma of the rectum, within 12 cm of the anal verge, staged T3-T4 and deemed suitable for curative resection. Radiotherapy (50.4 Gy in 28 fractions in five weeks and three days) was given with continuous infusion 5-fluorouracil throughout the course of radiotherapy. RESULTS: A total of 82 patients were accrued in 13 months. The median follow-up time was 4.1 (range, 2.3-4.5) years. There were 55 males (67 percent) and the median age was 59 (range, 27-87) years. Patients were staged pretreatment as T3 (89 percent) and resectable T4 (11 percent). Endorectal ultrasound was performed in 70 percent and magnetic resonance imaging in another 5 percent. The four-year overall and failure-free survival rates were 82 percent (95 percent Cl: 72-89) and 69 percent (95 percent Cl: 58-78), respectively. The cumulative incidence of local failure at four years was 3.9 percent (95 percent CI: 1.3-11). Risk of failures, local and distant, has not reached a plateau phase. CONCLUSION: This regimen can be delivered safely and without leading to a significant increase in late toxicity. It provides excellent local control and favorable overall survival. There is a need for longer follow-up than has commonly been used for the proper evaluation of failures after an effective regimen of preoperative chemoradiation.
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The aim of this in vitro study was to evaluate the fracture load and marginal accuracy of crowns made from a shrinkage-free ZrSiO4 ceramic cemented with glass-ionomer or composite cement after chewing simulation. Thirty-two human mandibular molars were randomly divided into two groups. All teeth were prepared for and restored with shrinkage-free ZrSiO4 ceramic crowns (Everest HPC (R), KaVo). The crowns of group A (N = 16) were luted to the teeth using KetacCem (R) and group B (N = 16) were adhesively cemented using Panavia (R) 21EX. Measurements of the marginal accuracy before and after cementation were made using replicas and an image analysis system. All specimens were exposed to 1.2 million cycles of thermo-mechanical fatigue in a chewing simulator. Surviving specimens were subsequently loaded until fracture in a static testing device. Fracture loads (N) were recorded. All specimens survived chewing simulation. The mean fracture loads (+/- s.d.) were Group A, 1622 N (+/- 433); group B, 1957 N (+/- 806). There was no significant difference between the two groups (P > 0.05). The marginal gap values before cementation were (mean +/- s.d.): Group A, 32.7 mu m (+/- 6.8); group B, 33.0 mu m (+/- 6.7).The mean marginal gap values after cementation were (+/- s.d.): Group A, 44.6 mu m (+/- 6.7); group B, 46.6 mu m (+/- 7.7). The marginal openings were significantly higher after cementation for both groups (P < 0.05). All test groups demonstrated fracture load and marginal accuracy values within the range of clinical acceptability.
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We evaluated the effect of adjuvant whole brain irradiation (WBI) after surgery or radiosurgery for solitary brain metastases in a Phase III multicentre trial with randomization to 30-36 Gy WBI or observation. The study was closed early due to slow accrual after 19 patients (WBI 10, observation 9). There was no difference in CNS failure-free survival or overall survival between the arms. There was a trend to reduced CNS relapse with WBI (30% versus 78%, P = 0.12). Limited analysis of quality of life and neurocognitive function data revealed no evidence of difference between the arms. Our results are not inconsistent with two larger randomized trials and support the use of upfront WBI to decrease brain recurrence in this setting. (c) 2006 Elsevier Ireland Ltd. All rights reserved.
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There are no controlled experiments in macroeconomic policy, nor in systematic programs of microeconomic reform, but a comparison between New Zealand and Australia over the period since 1984 provides as close an approach to such an experiment as is ever likely to be possible. From quite similar starting points the two countries pursued liberal reform programs that differed sharply, mainly as a result of exogenous differences in constitutional structures and the personal styles of the central actors. Australia followed a more cautious, piecemeal, consensus-based approach, whereas New Zealand, in contrast, adopted a radical, rapid, 'purist' platform. The NZ reform package was generally seen by contemporary commentators as representing a 'textbook' model for best practice reform. However, Australia since 1984 has performed much better than New Zealand, whose per capita GDP growth indeed ranked at or near the bottom of the OECD. In this paper, we assess a variety of explanations for the divergences in policies and outcomes.
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The research was carried out within a major public company. It sought to implement an approach to strategic planning which accounted for organisational values as well as employing a holistic value-free analysis of the firm and its environment. To this end, an 'ecological' model of the firm was formulated. A series of value-free strategic policies for its development were generated. These policies were validated by the company's top-management.They compared favourably with their own planning outcomes. The approach appeared to be diagnostically strong but lacked sufficient depth in the context of finding realistic corrective measures. However, feedback from the company showed it to be a useful complementary process to conventional procedures, in providing an explicitly different perspective. The research empirically evaluated the company's value-systems and their influence on strategy. It introduced the idea of an organisational 'self-concept' pre-determining the acceptability of various strategies.The values and the "self-concept' of the company were identified and validated, They appeared to have considerable influence on strategy. In addition, tho company's planning process within the decentralised structure was shown to be sub-optimal. This resulted from the variety of value systems maintained by different parts of the organisation. Proposals attempting to redress this situation were ofJered and several accepted. The study was postured as process-action research and the chosen perspective could be succinctly described as a 'worm's-eye view', akin to that of many real planners operating at some distance from the decision-making body. In this way, the normal strategic functionings of the firm and any changes resulting from the researcher's intervention were observed and recorded. Recurrent difficulties of the planning process resulting from the decentralised structure were identified. The overall procedure suggested as a result of the research aimed to increase the viabiIity of planning and the efficiency of the process. It is considered to be flexible enough to be applicable in a broader context.
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In memory of Professor D. Doitchinov ∗ This paper was written while the first author was supported by the Swiss National Science Foundation under grants 21–30585.91 and 2000-041745.94/1 and by the Spanish Ministry of Education and Sciences under DGES grant SAB94-0120. The second author was supported under DGES grant PB95-0737. During her stay at the University of Berne the third author was supported by the first author’s grant 2000-041745.94/1 from the Swiss National Science Foundation.
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We define Picard cycles on each smooth three-sheeted Galois cover C of the Riemann sphere. The moduli space of all these algebraic curves is a nice Shimura surface, namely a symmetric quotient of the projective plane uniformized by the complex two-dimensional unit ball. We show that all Picard cycles on C form a simple orbit of the Picard modular group of Eisenstein numbers. The proof uses a special surface classification in connection with the uniformization of a classical Picard-Fuchs system. It yields an explicit symplectic representation of the braid groups (coloured or not) of four strings.
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2000 Mathematics Subject Classification: 11G15, 11G18, 14H52, 14J25, 32L07.
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2000 Mathematics Subject Classification: 17B01, 17B30, 17B40.
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2000 Mathematics Subject Classification: 17B01, 17B30, 17B40.
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Oxygen-derived free radicals are important agents of tissue injury during ischemia and reperfusion. The aim of this study was to investigate changes in protein and lipid oxidation and antioxidant status in beating heart coronary artery surgery and conventional bypass and to compare oxidative stress parameters between the two bypass methods. Serum lipid hydroperoxide, nitric oxide, protein carbonyl, nitrotyrosine, vitamin E, and β-carotene levels and total antioxidant capacity were measured in blood of 30 patients undergoing beating heart coronary artery surgery (OPCAB, off-pump coronary artery bypass grafting) and 12 patients undergoing conventional bypass (CABG, on-pump coronary artery bypass grafting). In the OPCAB group, nitric oxide and nitrotyrosine levels decreased after reperfusion. Similarly, β-carotene level and total antioxidant capacity also decreased after anesthesia and reperfusion. In the CABG group, nitric oxide and nitrotyrosine levels decreased after ischemia and reperfusion. However, protein carbonyl levels elevated after ischemia and reperfusion. Vitamin E, β-carotene, and total antioxidant capacity decreased after ischemia and reperfusion. Significantly decreased nitration and impaired antioxidant status were seen after reperfusion in both groups. Moreover, elevated protein carbonyls were found in the CABG group. The off-pump procedure is associated with lower degree of oxidative stress than on-pump coronary surgery. © 2011 Pleiades Publishing, Ltd.
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As the population of the United States becomes more diverse and the immigrant Hispanic, limited English proficient (LEP) school age population continues to grow, understanding and addressing the needs of these students becomes a pressing question. The purpose of this study was to investigate the effects of group counseling, by a bilingual counselor, on the self-esteem, attendance and counselor utilization of Hispanic LEP high school students. The design for this study was a quasi-experimental design. The experimental and control groups consisted of one class from each of the four levels of English for Speakers of Other Languages (ESOL), I-IV. The counseling intervention, the independent variable, was delivered by a bilingual counselor once a week, for fifteen weeks.^ A total of 112 immigrant Hispanic LEP students selected from the total ESOL student population participated in the study. The experimental and control groups were administered the Culture Free Self Esteem Inventory (CFSEI) Form AD as a pretest and posttest. The Background Information Questionnaire (BIQ) was utilized to gather information on counselor utilization and demographic data. Attendance data were obtained from the students' computer records. At the conclusion of the study the differences between the experimental and control groups on the three dependent variables were compared.^ Statistical analyses of the data were done using SPSS statistical software. A multivariate analysis of variance (MANOVA) was utilized to determine if there were significant differences in the self-esteem scores, attendance and counselor utilization. Correlational analyses was utilized to determine if there was a relationship between English language proficiency and self-esteem and between acculturation level and self-esteem.^ The study results indicate that there were no significant differences in the self-esteem scores and attendance of the subjects in the experimental group at the completion of the group counseling treatment. Counselor utilization was statistically significant for the targeted population. A relationship was found between English language proficiency level and self-esteem scores for students in ESOL levels II, III and IV. No significant correlation was found between acculturation and self-esteem.^ Research on the dropout rates of LEP coupled with the results of this study show that students at the intermediate and advanced levels of ESOL (III and IV) exhibit more positive self-esteem and achieve higher graduation rates that levels I and II. LEP students at levels I and II, once they became familiar with the role and function of school counselors through group counseling, utilized their services. ^
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Tobacco was of primary importance to Spain, and its impact on Cuba's economy and society was greater than just the numbers of farms, workers, or production, demonstrated by the Spanish crown's outlay of monies for capital assets, bureaucrats' salaries, and payments to farmers for their crop. This study is a micro- and macro-level study of rural life in colonial Cuba and the interconnected relationships among society, agricultural production, state control, and the island's economic development. ^ By placing Cuba's tobacco farmers at the forefront of this social history, this work revisits and offers alternatives to two prevailing historiographical views of rural Cuba from 1763 (the year Havana returned to Spanish control following the Seven Years' War) to 1817 (the final year of the 100-year royal monopoly on Cuban tobacco). Firstly, it argues against the primacy of sugar over other agricultural crops, a view that has shaped decades of scholarship, and challenges the thesis which maintains the Cuban tobacco farmer was almost exclusively poor, white, and employed free labor, rather than slaves, in the production of their crop. ^ This study establishes the importance of tobacco as an agricultural product, and argues that Cuban tobacco growers were a heterogeneous group, revealing the role that its cultivation may have played in helping some slaves earn their freedom. ^
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The Rauer Group is an archipelago in Prydz Bay, East Antarctica. The ice-free islands and the surrounding shallow marine areas provide valuable archives for the reconstruction of the late Pleistocene and Holocene environmental and climatic history of the region. Two sediment records from two marine inlets of Rauer Group have been studied for their sedimentological, geochemical, and biological characteristics. Radiocarbon ages from one of the inlets indicate ice-free conditions within the last glacial cycle, probably during the second half of Marine Isotope Stage 3. Subsequent ice sheet coverage of Rauer Group during the Last Glacial Maxiumum (LGM) can be inferred from a till layer recovered in one of the basins. The inlets became ice-free prior to 11,200 cal yr BP, when biogenic sedimentation started. Deglacial processes in the catchments, however, influenced the inlets until ~9200 cal. yr BP as evidenced by the input of minerogenic material. Marine productivity under relatively open water conditions indicates an early Holocene climate optimum until 8200 cal. yr BP, which is followed by a cooler period with increased sea ice. Warmer conditions are inferred for the mid Holocene, when both basins experienced an input of freshwater between ~5700-3500 cal. yr BP, probably due to ice-sheet melting and increased precipitation on the islands. Neoglacial cooling in the late Holocene since c. 3500 cal yr BP is reflected by an increase in sea ice in both inlets.
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Limited information on the East Antarctic Ice Sheet (EAIS) geometry during Marine Isotope Stage 3 (MIS 3; 60-25 ka) restricts our understanding of its behaviour during periods of climate and sea level change. Ice sheet models forced by global parameters suggest an expanded EAIS compared to the Holocene during MIS 3, but field evidence from East Antarctic coastal areas contradicts such modelling, and suggests that the ice sheet margins were no more advanced than at present. Here we present a new lake sediment record, and cosmogenic exposure results from bedrock, which confirm that Rauer Group (eastern Prydz Bay) was ice-free for much of MIS 3. We also refine the likely duration of the Last Glacial Maximum (LGM) glaciation in the region. Lacustrine and marine sediments from Rauer Group indicate the penultimate period of ice retreat predates 50 ka. The lacustrine record indicates a change from warmer/wetter conditions to cooler/drier conditions after ca. 35 ka. Substantive ice sheet re-advance, however, may not have occurred until much closer to 20 ka. Contemporary coastal areas were still connected to the sea during MIS 3, restricting the possible extent of grounded ice in Prydz Bay on the continental shelf. In contrast, relative sea levels (RSL) deduced from field evidence indicate an extra ice load averaging several hundred metres thicker ice across the Bay between 45 and 32 ka. Thus, ice must either have been thicker immediately inland (with a steeper ice profile), or there were additional ice domes on the shallow banks of the outer continental shelf. Further work is required to reconcile the differences between empirical evidence of past ice sheet histories, and the history predicted by ice sheet models from far-field temperature and sea level records.