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Quantitative Examination (quantitative + examination)
Selected AbstractsReproductive asynchrony in natural butterfly populations and its consequences for female matelessnessJOURNAL OF ANIMAL ECOLOGY, Issue 4 2008Justin M. Calabrese Summary 1Reproductive asynchrony, where individuals in a population are short-lived relative to the population-level reproductive period, has been identified recently as a theoretical mechanism of the Allee effect that could operate in diverse plant and insect species. The degree to which this effect impinges on the growth potential of natural populations is not yet well understood. 2Building on previous models of reproductive timing, we develop a general framework that allows a detailed, quantitative examination of the reproductive potential lost to asynchrony in small natural populations. 3Our framework includes a range of biologically plausible submodels that allow details of mating biology of different species to be incorporated into the basic reproductive timing model. 4We tailor the parameter estimation methods of the full model (basic model plus mating biology submodels) to take full advantage of data from detailed field studies of two species of Parnassius butterflies whose mating status may be assessed easily in the field. 5We demonstrate that for both species, a substantial portion of the female population (6·5,18·6%) is expected to die unmated. These analyses provide the first direct, quantitative evidence of female reproductive failure due to asynchrony in small natural populations, and suggest that reproductive asynchrony exerts a strong and largely unappreciated influence on the population dynamics of these butterflies and other species with similarly asynchronous reproductive phenology. [source] Elastic deformations in a perfect bulk Si crystal studied by high-energy X-raysJOURNAL OF APPLIED CRYSTALLOGRAPHY, Issue 5 2009Alexander Gröschel Long-range strain fields induced in highly perfect bulk crystals during the manufacturing process significantly affect the quality and may even lead to spontaneous fracturing. Obviously a quantitative assessment of these deformations is crucial. A possible means is to examine the diffraction of X-rays by strained crystals, as the deformations bear on the diffraction characteristics of such crystals. In this report a quantitative examination of the diffraction characteristics of a perfect silicon bulk crystal with long-range strain fields in a well defined geometry is presented. The experiments were carried out using a high-energy X-ray laboratory source. By simulating the elastic deformation of the crystal by a finite element program the strain fields of the diffracting crystal are accessed. From these, simulated data values for integrated intensities can be derived on the basis of the dynamical diffraction theory for slightly distorted crystals. The theoretical calculations show good agreement with the experimental measured values. The smallest deformation yielding a noticeable change of the integrated intensity can be associated with a bending radius of the diffracting lattice planes of 16,km. [source] The validation of a rating scale to assess dietitians' use of behaviour change skillsJOURNAL OF HUMAN NUTRITION & DIETETICS, Issue 4 2008G. Bonner Background:, Evidence suggests that education alone is unlikely to elicit dietary-behavioural change (Contento, 1995). Consequently, many dietitians are moving from a traditional advice-giving role to one which utilises ,behaviour change skills' (BCS) in dietary counselling. BCS is an umbrella term used to cover a wide range of skills and techniques drawn from the fields of counselling, motivational interviewing (MI) and cognitive behavioural therapy (CBT). In order to assess the efficacy of this approach, a means of quantifying BCS-use is required. This two-stage study aimed to validate a newly-devised scale to assess dietitians' BCS-use in one-to-one dietary counselling. Methods:, Items for the scale were generated by drawing on the literature, syllabi for training in BCS and its parent disciplines (counselling, MI and CBT), and specialist dietitians. The resulting scale and manual were revised following assessment of content validity by expert panel and piloting. In stage one, 21 dietetic consultations were audiotaped and rated for BCS-use by three BCS-trained dietitians. Inter-rater agreement was calculated using the kappa statistic and intra-class correlation (ICC), to give a ,chance corrected' measure of agreement. Validity was tested using a psychologist's subjective assessment of BCS-use as a proxy ,gold-standard' compared with the dietitians' ratings, again using kappa and ICC. In stage two the scale was further revised before an additional 20 audiotaped consultations were analysed using the same procedure. Ethical approval for the study was given by the appropriate NHS and university research ethics committees. Results:, At stage one, although kappas were fairly poor for agreement on individual criteria, the ICC for overall scores indicated a ,fair' level of agreement, according to Shrout's (1998) classifications: ICC = 0.584 (CI 0.339,0.784). Results for validity were poor with the psychologist frequently rating higher than the dietitians. At stage two, following scale revision, results for inter-rater agreement improved with more criteria showing ,moderate' or ,substantial' agreement. Ten out of the 21 criteria achieved levels of agreement classified as ,fair' or higher for all three rater pairs. The ICC for overall scores improved to indicate ,moderate' agreement: ICC = 0.640 (CI 0.404,0.821). Validity results remained poor. Discussion:, The moderate level of overall inter-rater agreement observed in the revised scale is considered acceptable (Jones, 2006) and indicates this tool is useful. This measure is more relevant to the purpose of the tool than agreement on individual criteria given it is intended to classify consultations overall as low/medium/high use of BCS rather than to examine individual skills. However, in terms of validity, the discrepancy between dietitian and psychologist ratings requires further investigation. It is hypothesized that the dietitians had higher expectations of what a dietitian could achieve in terms of proficiency in BCS and, as such, rated more stringently than the psychologist. Achieving a clear picture of validity usually necessitates a series of assessments (Murphy & Davidshofer, 2005); the BCS rating scale is no exception with further testing required. Conclusions:, The revised scale shows acceptable inter-rater reliability and robust content validity in our study sample. However, quantitative examination of validity gave poor results and further assessment is required to provide a tool with which we can confidently assess dietitians' use of BCS. References, Contento, I., Balch, G.I., Bronner, Y.L. et al. (1995) The effectiveness of nutrition education and implications for nutrition education policy, programs, and research: a review of the research. J. Nutr. Educ.27, 355,364. Jones, J.M. (2006) Nutritional Screening and Assessment Tools. New York: Nova Science Publishers. Murphy, K.R. & Davidshofer, C.O. (2005) Psychological Testing , Principles and Applications, 6th edn. New Jersey: Pearson Education Inc. Shrout, P. (1998) Measurement reliability and agreement in psychiatry. Stat. Methods Med. Res. 7, 301,317. [source] Dimensions of style: Context, politics and motivation in gay Israeli speech1JOURNAL OF SOCIOLINGUISTICS, Issue 1 2009Erez Levon Sociolinguistic research has traditionally examined stylistic variation as a way of understanding how speakers may use language indexically. Quantitatively, research has sought to correlate observed patterns of variation across such external parameters as context or topic with the ways in which speakers linguistically orient themselves to their immediate surroundings or to some other socially-salient reference group. Recently, this approach has been criticized for being too mechanistic. In this paper, I present a new method for examining stylistic variation that addresses this critique, and demonstrate how an attention to speakers' motivations and interactional goals can be reconciled with a quantitative analysis of variation. I illustrate the proposed method with a quantitative examination of systematic patterns of prosodic variation in the speech of a group of Israeli men who are all members of various lesbian and gay political-activist groups. [source] Influence of nonspecific brain and plasma binding on CNS exposure: implications for rational drug discoveryBIOPHARMACEUTICS AND DRUG DISPOSITION, Issue 8 2002J. Cory Kalvass Abstract Relative plasma, brain and cerebrospinal fluid (CSF) exposures and unbound fractions in plasma and brain were examined for 18 proprietary compounds in rats. The relationship between in vivo brain-to-plasma ratio and in vitro plasma-to-brain unbound fraction (fu) was examined. In addition, plasma fu and brain fu were examined for their relationship to in vivo CSF-to-plasma and CSF-to-brain ratios, respectively. Findings were delineated based on the presence or absence of active efflux. Finally, the same comparisons were examined in FVB vs. MDR 1a/1b knockout mice for a selected P-glycoprotein (Pgp) substrate. For the nine compounds without indications of active efflux, predictive correlations were observed between ratios of brain-to-plasma exposure and plasma-to-brain fu (r2 = 0.98), CSF-to-brain exposure vs. brain fu (r2 = 0.72), and CSF-to-plasma exposure vs. plasma fu (r2 = 0.82). For the nine compounds with indications of active efflux, nonspecific binding data tended to over predict the brain-to-plasma and CSF-to-plasma exposure ratios. Interestingly, CSF-to-brain exposure ratio was consistently under predicted by brain fu for this set. Using a select Pgp substrate, it was demonstrated that the brain-to-plasma exposure ratio was identical to that predicted by plasma-to-brain fu ratio in MDR 1a/1b knockout mice. In FVB mice, plasma-to-brain fu over predicted brain-to-plasma exposure ratio to the same degree as the difference in brain-to-plasma exposure ratio between MDR 1a/1b and FVB mice. Consistent results were obtained in rats, suggesting a similar kinetic behavior between species. These data illustrate how an understanding of relative tissue binding (plasma, brain) can allow for a quantitative examination of active processes that determine CNS exposure. The general applicability of this approach offers advantages over species- and mechanism-specific approaches. Copyright © 2002 John Wiley & Sons, Ltd. [source] Refocusing children's services: evaluation of an initial assessment processCHILD & FAMILY SOCIAL WORK, Issue 2 2001Platt This paper describes a small scale evaluation carried out in a social services department in England. It was concerned with the impact of a pilot initial assessment process used by social workers with children in need. The pilot was, in part, an attempt to adopt the ,refocusing' agenda of the late 1990s, and the analysis is presented within this context. The research involved quantitative examination of 47 cases, and qualitative interviews with the social worker and main carer/parent in a subsample of 10. The results suggested a high level of consumer satisfaction with the assessment/family support approach, and very little evidence that the use of broadly based assessments where there are low-key concerns about a child's safety would be a dangerous form of practice. A wholehearted commitment to refocusing children's services will, however, require attention to resourcing and management issues. [source] Image analysis and quantification in lung tissueCLINICAL & EXPERIMENTAL ALLERGY, Issue 3 2001W.I. De Boer On 9,10 September 1999, an international workshop on image analysis and quantification in lung tissue was held at the Leiden University Medical Center, Leiden, The Netherlands. Participants with expertise in pulmonary and/or pathology research discussed the validity and applicability of techniques used for quantitative examination of inflammatory cell patterns and gene expression in bronchial or parenchymal tissue in studies focusing on asthma and chronic obstructive pulmonary disease (COPD). Differences in techniques for tissue sampling and processing, immunohistochemistry, cell counting and densitometry are hampering the comparison of data between various laboratories. The main goals of the workshop were to make an inventory of the techniques that are currently available for each of these aspects, and in particular to address the validity and unresolved problems of using digital image analysis (DIA) as opposed to manual scoring methods for cell counting and assessment of gene and protein expression. Obviously, tissue sampling and handling, fixation and (immunohistochemical) staining, and microscope settings, are having a large impact on any quantitative analysis. In addition, careful choices will have to be made of the commercially available optical and recording systems as well as the application software in order to optimize quantitative DIA. Finally, it appears to be of equal importance to reach consensus on which histological areas are to be analysed. The current proceedings highlight recent advances and state of the art knowledge on digital image analysis for lung tissue, and summarize the established issues and remaining questions raised during the course of the workshop. [source] Three-dimensional CT angiography: A new technique for imaging microvascular anatomyCLINICAL ANATOMY, Issue 2 2007Ashley P. Tregaskiss Abstract To date there has been no satisfactory research method for imaging microvascular anatomy in three dimensions (3D). In this article we present a new technique that allows both qualitative and quantitative examination of the microvasculature in 3D. In 10 fresh cadavers (7 females, 3 males, mean age 68 years), selected arteries supplying the abdominal wall and back were injected with a lead oxide/gelatin contrast mixture. From these regions, 30 specimens were dissected free and imaged with a 16-slice spiral computed tomographic (CT) scanner. Using three-dimensional CT (3D-CT) angiography, reconstructions of the microvasculature of each specimen were produced and examined for their qualitative content. Two calibration tools were constructed to determine (1) the accuracy of linear measurements made with CT software tools, and (2) the smallest caliber blood vessel that is reliably represented on 3D-CT reconstructions. Three-dimensional CT angiography produced versatile, high quality angiograms of the microvasculature. Correlation between measurements made with electronic calipers and CT software tools was very high (Lin's concordance coefficient, 0.99 (95% CI 0.99,0.99)). The finest caliber of vessel reliably represented on the 3D-CT reconstructions was 0.4 mm internal diameter. In summary, 3D-CT angiography is a simple, accurate, and reproducible method that imparts a much improved perception of anatomy when compared with existing research methods. Measurement tools provide accurate quantitative data to aid vessel mapping and preoperative planning. Further work will be needed to explore the full utility of 3D-CT angiography in a clinical setting. Clin. Anat. 20:116,123, 2007. © 2006 Wiley-Liss, Inc. [source] | ||||||||||||||||