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Clear Impact (clear + impact)
Selected AbstractsHarmonization of light scatter and fluorescence flow cytometry profiles obtained after staining peripheral blood leucocytes for cell surface-only versus intracellular antigens with the Fix & PermÔ reagent,,§CYTOMETRY, Issue 1 2010Elaine Sobral da Costa Abstract Staining for intracellular markers with the Fix & PermÔ reagent is associated with variations in the scatter properties of leucocytes, limiting automated analysis of flow cytometry (FCM) data. Here, we investigated those variables significantly contributing to changes in the light scatter, autofluorescence, and bcl2 staining characteristics of peripheral blood (PB) leucocytes, after fixation with Fix & PermTM. Our major aim was to evaluate a new mathematical approach for automated harmonization of FCM data from datafiles corresponding to aliquots of a sample treated with cell-surface-only versus Fix & Perm intracellular staining techniques. Overall, neither the anticoagulant used nor sample storage for <24 h showed significant impact on the light scatter and fluorescence properties of PB leucocytes; similarly, the duration of the fixation period (once >15 min were used) had a minimum impact on the FCM properties of PB leucocytes. Conversely, changes in cell/protein concentrations and the fixative/sample (vol/vol) ratio had a clear impact on the light scatter features of some populations of leucocytes. Accordingly, lower cell/protein concentrations were associated with lower scatter values, particularly for the neutrophils. Such changes could be partially corrected through the use of higher fixative to sample volume ratios. Despite the variable changes detected between aliquots of the same sample treated with cell surface-only versus intracellular staining procedures, the new mathematical approach here proposed and evaluated for automated harmonization of common parameters in both datafiles, could correct the FCM profiles of leucocytes derived from cells undergoing conventional fixation/permeabilization procedures, and made them indistinguishable from those corresponding to aliquots of the same sample treated with cell-surface-only staining techniques. © 2009 Clinical Cytometry Society [source] Cutaneous melanoma: interferon alpha adjuvant therapy for patients at high risk for recurrent diseaseDERMATOLOGIC THERAPY, Issue 1 2006Marko Lens ABSTRACT:, Systemic adjuvant therapy in melanoma patients is the systemic treatment that is administered with the goal of eradicating micrometastatic deposits in patients who are clinically free of disease after surgical removal of the primary melanoma, but with a high risk of systemic recurrence. Interferon-alpha (IFN-,) is one of the most frequently used adjuvant therapies. Several randomized trials evaluated the efficacy of IFN-, in melanoma patients. However, results from conducted trials are controversial. Twelve randomized IFN-, trials are discussed in detail. All trials, including meta-analysis, failed to demonstrate a clear impact of IFN-, therapy on overall survival in melanoma patients. Based on currently available evidence, IFN-, therapy in the adjuvant setting should not be considered standard of care for patients who have melanoma. Results from ongoing studies are awaited. Further research for this therapy is required. [source] Epoxiconazole causes changes in testicular histology and sperm production in the Japanese quail (Coturnix coturnix japonica)ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 11 2008Konstanze Grote Abstract The fungicide epoxiconazole (Epox), a triazole, belongs to the group of azole compounds that are extensively used as fungicides in various fruit crops. The frequent use of agricultural lands for wintering by migrating birds can be the source of their increased dietary intake of agricultural pesticides. We investigated whether exposure to Epox causes effects on avian fertility and reproduction, using the Japanese quail (Coturnix coturnix japonica) as a model species for the assessment of reproductive effects of pesticides in wild birds. Epox was administered to adult Japanese quail for three weeks at dietary levels of 10, 50, and 500 ppm, and possible effects on reproduction were investigated. Epox administration resulted in a significantly decreased number of spermatids in the 50- and 500-ppm dose groups. Histopathology showed a reduced number of testicular canaliculi with visible germ cells and a reduction in spermatid number. However, testis weight was not affected up to the highest dose level. No impact was observed on hormone levels, fertility, and reproductive outcome, as laying rate and percentage of fertile eggs were not altered. Likewise, treatment had no influence on the egg or chick parameters evaluated. A time- and dose-related transfer of Epox into the eggs was determined in all treatment groups. We conclude that dietary treatment of Japanese quail with 50 and 500 ppm of the triazole fungicide Epox resulted in a clear impact on the testis. The evaluation of the additional endpoints spermatid count and testicular histology have proven useful and are recommended for future studies on avian reproduction. [source] Literature, the Interpretive Mode, and Novice LearnersMODERN LANGUAGE JOURNAL, Issue 1 2007VIRGINIA M. SCOTT The qualitative study reported in this article analyzes how novice learners develop the interpretive mode (as outlined in Standard 1.2 of the Standards for Foreign Language Learning in the 21st Century, 1996, 1999) in a classroom setting when reading a literary text in a foreign language (FL). Using unmotivated looking through conversation analysis, we examined transcripts from video- and audiorecordings of students' discussions in a teacher-moderated classroom setting and in small groups of 3 to 4 students. Our findings indicate that novice learners were able to interpret and understand a challenging literary text (in this case, a poem) if they were in the teacher-moderated group. In addition, our findings suggest that use of the first language was effective in encouraging interpretive talk among students in the teacher-moderated classroom but not among students in small groups. Ultimately, these findings indicate that the nature of the teacher-moderated, yet distinctly student-centered, interaction had a clear impact on developing the interpretive mode in novice learners. [source] Do microsatellites reflect genome-wide genetic diversity in natural populations?MOLECULAR ECOLOGY, Issue 5 2010A comment on Väli et al. (2008) Abstract A recent study by Väli et al. (2008) highlights that microsatellites will often provide a poor prediction of the genome-wide nucleotide diversity of wild populations, but does not fully explain why. To clarify and stress the importance of identity disequilibrium and marker variability for correlations between multilocus heterozygosity and genome-wide genetic variability, we performed a simple simulation with different types of markers, corresponding to microsatellites and SNPs, in populations with different inbreeding history. The importance of identity disequilibrium was apparent for both markers and there was a clear impact of marker variability. [source] Curricula and the use of ICT in education: Two worlds apart?BRITISH JOURNAL OF EDUCATIONAL TECHNOLOGY, Issue 6 2007Jo Tondeur In many countries, information and communication technology (ICT) has a clear impact on the development of educational curricula. In Flanders, the education government has identified and defined a framework of ICT competencies for expected outcomes, related to knowledge, skills and attitudes that pupils are expected to achieve at the end of primary school. However, it has never been examined whether teachers are using ICT in accordance with the competencies proposed by the Flemish government. In order to answer this question, a survey was conducted among 570 respondents in a stratified sample of 53 primary schools. Results show that teachers mainly focus on the development of technical ICT skills, whereas the ICT curriculum centres on the integrated use of ICT within the learning and teaching process. This indicates the existence of a gap between the proposed and the implemented curriculum for ICT. The paper concludes with the potential value of a school-based ICT curriculum that ,translates' the national ICT-related curriculum into an ICT plan as part of the overall school policy. [source] Fetal programming: Adaptive life-history tactics or making the best of a bad start?AMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 1 2005James Holland Jones Fetal programming is an ontogenetic phenomenon of increasing interest to human biologists. Because the downstream consequences of fetal programming have clear impacts on specific life-history traits (e.g., age at first reproduction and the general age-pattern of reproductive investments), a number of authors have raised the question of the adaptive significance of fetal programming. In this paper, I review in some detail several classical models in life-history theory and discuss their relative merits and weaknesses for human biology. I suggest that an adequate model of human life-history evolution must account for the highly structured nature of the human life cycle, with its late age at first reproduction, large degree of iteroparity, highly overlapping generations, and extensive, post-weaning parental investment. I further suggest that an understanding of stochastic demography is essential for answering the question of the adaptive significance of fetal programming, and specifically the finding of low birth weight on smaller adult body size and earlier age at first reproduction. Using a stage-structured stochastic population model, I show that the downstream consequences of early deprivation may be "making the best of a bad start" rather than an adaptation per se. When a high-investment strategy entails survival costs, the alternate strategy of early reproduction with relatively low investment may have higher fitness than trying to play the high-investment strategy and failing. Am. J. Hum. Biol. 17:22,33, 2005. © 2004 Wiley-Liss, Inc. [source] | ||||||||||