Methodological Improvements (methodological + improvement)

Distribution by Scientific Domains


Selected Abstracts


Neutron Activation Analysis, Atomic Absorption and X-Ray Fluorescence Spectrometry Review for 2003

GEOSTANDARDS & GEOANALYTICAL RESEARCH, Issue 1 2005
L. Paul Bédard
This review for the year 2003 deals with three relatively well-established, mature, analytical techniques (neutron activation analysis, atomic absorption spectrometry and X-ray fluorescence spectrometry) that nevertheless remain very important for the characterisation of geological and environmental samples. Developments in neutron activation analysis included modification to the technique in relation to the determination of platinum-group elements, as well as consideration of sample size in ore grade estimation. A considerable body of literature was published on the application of atomic absorption spectrometry in the analysis of environmental samples. Many of these proposed technical and methodological improvements, notably in extraction procedures. X-ray fluorescence spectrometry saw developments in in situ analysis, synchrotron micro-XRF (,-SRXRF) and a confocal X-ray set-up for 3D elemental imaging. XRF technologies were used in the analysis of geological samples, reference materials, glasses, solutes and environmental materials. [source]


Compatibility, Leisure, and Satisfaction in Marital Relationships

JOURNAL OF MARRIAGE AND FAMILY, Issue 2 2002
Duane W. Crawford
This study challenges the prevailing view that marital companionship promotes marital satisfaction. By following a cohort of married couples for over a decade and by incorporating several methodological improvements,such as refining the measurement of marital satisfaction, determining how much spouses enjoy doing the leisure activities they pursue together and apart, and using diary data to portray marital leisure patterns,we found that the association between companionship and satisfaction is less robust than previously believed, and that it depends on how often spouses pursue activities that reflect their own and their partner's leisure preferences. Over time, involvement in leisure liked by husbands but disliked by wives, whether as a couple or by husbands alone, is both a cause and a consequence of wives' dissatisfaction. [source]


Reproducibility of tricuspid regurgitant jet velocity measurements in children and young adults with sickle cell disease undergoing screening for pulmonary hypertension,

AMERICAN JOURNAL OF HEMATOLOGY, Issue 10 2010
Robert I. Liem
The reproducibility of tricuspid regurgitant jet velocity (TRJV) measurements by Doppler echocardiography has not been subjected to systematic evaluation among individuals with sickle cell disease (SCD) undergoing screening for pulmonary hypertension. We examined sources of disagreement associated with peak TRJV in children and young adults with SCD. Peak TRJV was independently measured and interpreted a week apart by separate sonographers and readers, respectively, in 30 subjects (mean age, 15.8 ± 3.3 years) who provided 120 observations. We assessed intra-/inter-reader, intra-/inter-sonographer, sonographer-reader, and within subject agreement using Intraclass Correlation Coefficient (ICC) and Cohen's kappa (,). Agreement was examined graphically using Bland-Altman plots. Although sonographers could estimate and measure peak TRJV in all subjects, readers designated tricuspid regurgitation nonquantifiable in 10,17% of their final interpretations. Intra-reader agreement was highest (ICC = 0.93 [95% CI 0.86, 0.97], P = 0.0001) and within subject agreement lowest (ICC = 0.36 [95% CI 0.02, 0.64], P = 0.021) for single TRJV measurements. Similarly, intra-reader agreement was highest (, = 0.74 [95% CI 0.53, 0.95], P = 0.0001) and within subject lowest (, = 0.14 [95% CI ,0.17, 0.46], P = 0.38) when sonographers and readers categorized TRJV measurements. On Bland-Altman plots, absolute differences in observations increased with higher mean TRJV readings for intra-/inter-reader agreement. Peak TRJV measurements in individual children and young adults with SCD are affected by several sources of disagreement, underscoring the need for methodological improvements that ensure reproducibility of this screening modality for making clinical decisions in this population. Am. J. Hematol., 2010. © 2010 Wiley-Liss, Inc. [source]


Glutamic acid decarboxylase and IA-2 autoantibodies in type 1 diabetes: comparing sample substrates for autoantibody determinations

PEDIATRIC DIABETES, Issue 1 2000
C Wasserfall
Large-scale programs designed to assess risk for type 1 diabetes through serologic assessment of autoantibodies to recombinant ,-cell autoantigens are hampered by several limitations, including the methods for sample collection and assay performance, as well as the volume required for autoantibody determinations. The present study was designed to develop a low sample-volume, primary screening method for autoantibody detection of high specificity and sensitivity, and to determine the feasibility of dried blood spots collected on filter paper in serving as vehicles for such determinations. Autoantibodies to glutamic acid decarboxylase (GAD) and ICA512bdc (IA-2), both individually and in combination, were determined in persons with type 1 diabetes, healthy controls, or individuals with other autoimmune disorders. Autoantibody results for serum, plasma, and dried blood spots were compared. GAD, IA-2, and combined GAD/IA-2 autoantibodies were concordant in their measurement from minimal volumes of serum, plasma, and whole blood extracted from dried filter paper. The autoantibody levels from the dried blood spots were, however, lower than corresponding serum samples, and, as currently designed, failed to detect low-titer autoantibodies. Despite this limitation, screening for diabetes risk can be performed using small volumes of whole blood, serum, or plasma collected onto filter paper. These methodological improvements should simplify matters, reduce costs, and increase the efficacy of screening programs for type 1 diabetes. Further development of better substrates/methods for blood-specimen collection seems necessary to exploit the full potential of this and other autoantibody measurement strategies for screening large populations. [source]


Are apes inequity averse?

AMERICAN JOURNAL OF PRIMATOLOGY, Issue 2 2009
New data on the token-exchange paradigm
Abstract Recent studies have produced mixed evidence about inequity aversion in nonhuman primates. Brosnan et al. [Proceedings of the Royal Society of London. Series B. Biological Sciences 272:253,258, 2005] found inequity aversion in chimpanzees and argued that effort is crucial, if subjects are to evaluate how they are rewarded in comparison to a competitor for an identical performance. In this study we investigated inequity aversion with chimpanzees, bonobos and orangutans, using the method of Brosnan et al. [Proceedings of the Royal Society of London. Series B. Biological Sciences 272:253,258, 2005] after introducing some methodological improvements. Subjects always received a less-preferred food in exchange for a token, whereas the competitor received either the same type of food for their token (equity) or a more favored food for it (inequity). Apes did not refuse more of the less-preferred food when a competitor had received the more favored food. Thus, with an improved methodology we failed to reproduce the findings of Brosnan et al. [Proceedings of the Royal Society of London. Series B. Biological Sciences 272:253,258, 2005] that apes show inequity aversion. Am. J. Primatol. 71:175,181, 2009. © 2008 Wiley-Liss, Inc. [source]


A new index of access to primary care services in rural areas

AUSTRALIAN AND NEW ZEALAND JOURNAL OF PUBLIC HEALTH, Issue 5 2009
Matthew R. McGrail
Abstract Objective: To outline a new index of access to primary care services in rural areas that has been specifically designed to overcome weaknesses of using existing geographical classifications. Methods: Access was measured by four key dimensions of availability, proximity, health needs and mobility. Population data were obtained through the national census and primary care service data were obtained through the Medical Directory of Australia. All data were calculated at the smallest feasible geographical unit (collection districts). The index of access was measured using a modified two-step floating catchment area (2SFCA) method, which incorporates two necessary additional spatial functions (distance-decay and capping) and two additional non-spatial dimensions (health needs and mobility). Results: An improved index of access, specifically designed to better capture access to primary care in rural areas, is achieved. These improvements come from: 1) incorporation of actual health service data in the index; 2) methodological improvements to existing access measures, which enable both proximity to be differentiated within catchments and the use of varying catchment sizes; and 3) improved sensitivity to small-area variations. Conclusion: Despite their recognised weaknesses, the Australian government uses broad geographical classifications as proxy measures of access to underpin significant rural health funding programs. This new index of access could provide a more equitable means for resource allocation. Implications: Significant government funding, aimed at improving health service access inequities in rural areas, could be better targeted by underpinning programs with our improved access measure. [source]