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Quantitative Indices (quantitative + index)
Selected AbstractsA Surface-Based Approach to Measuring Spatial SegregationGEOGRAPHICAL ANALYSIS, Issue 2 2007David O'Sullivan Quantitative indices of residential segregation have been with us for half a century, but suffer significant limitations. While useful for comparison among regions, summary indices fail to reveal spatial aspects of segregation. Such measures generally consider only the population mix within zones, not between them. Zone boundaries are treated as impenetrable barriers to interaction between population subgroups, so that measurement of segregation is constrained by the zoning system, which bears no necessary relation to interaction among population subgroups. A segregation measurement approach less constrained by the chosen zoning system, which enables visualization of segregation levels at the local scale and accounts for the spatial dimension of segregation, is required. We propose a kernel density estimation approach to model spatial aspects of segregation. This provides an explicitly geographical framework for modeling and visualizing local spatial segregation. The density estimation approach lends itself to development of an index of spatial segregation with the advantage of functional compatibility with the most widely used index of segregation (the dissimilarity index D). We provide a short review of the literature on measuring segregation, briefly describe the kernel density estimation method, and illustrate how the method can be used for measuring segregation. Examples using a simulated landscape and two empirical cases in Washington, DC and Philadelphia, PA are presented. [source] A Clinical Index for Disease Activity in Cats with Chronic EnteropathyJOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 5 2010A.E. Jergens Background: There is a need for a clinically useful, quantitative index for measurement of disease activity in cats with chronic enteropathy (CE). Objective: To develop a numerical activity index that is of practical value to clinicians treating CE in cats. Animals: Eighty-two cats with CE. Methods: Retrospective case review of 59 cats diagnosed with inflammatory bowel disease (IBD). Prospective validation study of 23 cats having either IBD or food-responsive enteropathy (FRE). Multivariate regression analysis was used to identify which combination of clinical and laboratory variables were best associated with intestinal inflammation of IBD. This combination of variables was expressed in a score that was used as an activity index for the prospective assessment of disease activity and of the effect of treatment in cats with IBD or FRE. Results: The combination of gastrointestinal signs, endoscopic abnormalities, serum total protein, serum alanine transaminase/alkaline phosphatase activity, and serum phosphorous concentration had the best correlation with histopathologic inflammation and comprise the feline chronic enteropathy activity index (FCEAI). Positive treatment responses in cats with CE were accompanied by significant (P < .05) reductions in FCEAI scores after treatment. Conclusions and Clinical Importance: The FCEAI is a simple numerical measure of inflammatory activity in cats with CE. The scoring index can be reliably used in the initial assessment of disease severity for both IBD and FRE and as a measure of clinical response to treatment for these disorders. [source] Evolution and modulation of intracellular calcium release during long-lasting, depleting depolarization in mouse muscleTHE JOURNAL OF PHYSIOLOGY, Issue 19 2008Leandro Royer Intracellular calcium signals regulate multiple cellular functions. They depend on release of Ca2+ from cellular stores into the cytosol, a process that in many types of cells appears to be tightly controlled by changes in [Ca2+] within the store. In contrast with cardiac muscle, where depletion of Ca2+ in the sarcoplasmic reticulum is a crucial determinant of termination of Ca2+ release, in skeletal muscle there is no agreement regarding the sign, or even the existence of an effect of SR Ca2+ level on Ca2+ release. To address this issue we measured Ca2+ transients in mouse flexor digitorum brevis (FDB) skeletal muscle fibres under voltage clamp, using confocal microscopy and the Ca2+ monitor rhod-2. The evolution of Ca2+ release flux was quantified during long-lasting depolarizations that reduced severely the Ca2+ content of the SR. As in all previous determinations in mammals and non-mammals, release flux consisted of an early peak, relaxing to a lower level from which it continued to decay more slowly. Decay of flux in this second stage, which has been attributed largely to depletion of SR Ca2+, was studied in detail. A simple depletion mechanism without change in release permeability predicts an exponential decay with time. In contrast, flux decreased non-exponentially, to a finite, measurable level that could be maintained for the longest pulses applied (1.8 s). An algorithm on the flux record allowed us to define a quantitative index, the normalized flux rate of change (NFRC), which was shown to be proportional to the ratio of release permeability P and inversely proportional to Ca2+ buffering power B of the SR, thus quantifying the ,evacuability' or ability of the SR to empty its content. When P and B were constant, flux then decayed exponentially, and NFRC was equal to the exponential rate constant. Instead, in most cases NFRC increased during the pulse, from a minimum reached immediately after the early peak in flux, to a time between 200 and 250 ms, when the index was no longer defined. NFRC increased by 111% on average (in 27 images from 18 cells), reaching 300% in some cases. The increase may reflect an increase in P, a decrease in B, or both. On experimental and theoretical grounds, both changes are to be expected upon SR depletion. A variable evacuability helps maintain a constant Ca2+ output under conditions of diminishing store Ca2+ load. [source] Circulating CD10,/CD16low neutrophils provide a quantitative index of active bone marrow neutrophil releaseBRITISH JOURNAL OF HAEMATOLOGY, Issue 4 2005Y. Orr Summary Circulating neutrophil phenotype and function are altered during neutrophilia associated with acute inflammatory states, however, the contribution of bone marrow neutrophil release to these changes has been difficult to quantify in humans. Accelerated release of neutrophils, with potentially distinct attributes, from the bone marrow and their dilution within the circulating pool may produce these apparent changes. Unfortunately selective analysis of these newly emergent neutrophils is difficult given their morphologic similarity to those already in the circulation and the coincident effect of soluble inflammatory mediators on circulating neutrophil phenotype and function. Using whole blood flow cytometry and cardiac surgery as an inflammatory stimulus, we demonstrate the emergence of a unique subpopulation of circulating neutrophils characterised as CD10,/CD16low, indicative of active bone marrow neutrophil release peri-operatively. CD10,/CD16low neutrophils emerge at the same operative stages as band forms and a left shift, yet represent over 40% of circulating neutrophils postoperatively, and generate a greater stimulus-induced [Ca2+]i flux than their CD10+ counterparts. We conclude that CD10,/CD16low neutrophils represent a significant proportion of the circulating pool after cardiac surgery and that bone marrow release, a major contributor to neutrophilia, influences the phenotype and functional activity of circulating neutrophils following this acute inflammatory stimulus. [source] Quantitative evaluation of corneal epithelial oedema by confocal microscopyCLINICAL & EXPERIMENTAL OPHTHALMOLOGY, Issue 3 2009Naoyuki Morishige MD PhD Abstract Background:, To develop a novel quantitative index for evaluation of corneal epithelial oedema, the pixel intensity of confocal microscopic images was measured derived from the basal cell layer (BCL) of the corneal epithelium in normal eyes, eyes before and after cataract surgery, and eyes affected by bullous keratopathy. Methods:, Five eyes of five normal volunteers, 14 eyes of 11 cataract patients and 12 eyes of 12 bullous keratopathy patients were examined by confocal microscopy. The cataract patients underwent cataract surgery, and they were examined by confocal microscopy, corneal pachymetry, and anterior fluorometry both before and at various times after surgery. The pixel intensity of BCL images obtained by confocal microscopy was measured and expressed as the BCL index. Results:, The coefficient of variation for repeated (five times) measurement of the BCL index in each of the five normal eyes was 3.4%. The BCL index was 54.8 ± 5.3 (mean ± SD) before surgery, increased significantly to 65.2 ± 10.0 on the day after surgery, and gradually decreased thereafter in the cataract patients. The time-course of the BCL index coincided well with that of corneal thickness and anterior fluorometry value. The BCL index in eyes affected by bullous keratopathy was significantly increased at 95.0 ± 6.4. Conclusion:, The BCL index was increased after cataract surgery and in eyes affected by bullous keratopathy, conditions associated with corneal epithelial oedema. This quantitative measure obtained by confocal microscopy may prove useful in the clinical evaluation of corneal epithelial oedema. [source] The European perspective of psychiatric reformACTA PSYCHIATRICA SCANDINAVICA, Issue 2001T. Becker Objective:,To provide a framework of mental health care reform across Europe. Method:,On the basis of summary quantitative indices and expert ratings of broad aspects of mental health care structure, the process and outcome of psychiatric reform common trends and differences are outlined. Results:,There has been a broad trend away from an institutional model of care with the mental hospital as the dominant institution, and community- and general hospital-based mental health services of varying comprehensiveness are in place in most countries. The social and broad community aspects of psychiatric reform have generally been somewhat less successful than changes in service set-up. Assessment of reform outcomes proves particularly difficult. Conclusion:,Psychiatric reform processes have achieved some of their aims, and there are broadly similar trends. Regional variation is substantial and may be as important as cross-national differences. Mental health care reform is ongoing across the European region. [source] Quantitative and Qualitative Measures of Hippocampal Atrophy Are Not Correlated in Healthy Older MenJOURNAL OF NEUROIMAGING, Issue 2 2010Karen J. Ferguson PhD ABSTRACT BACKGROUND AND PURPOSE In neuroimaging studies of dementia and mild cognitive impairment, hippocampal atrophy (HA) is commonly assessed by qualitative ratings of hippocampal appearance, or by measuring hippocampal volumes. These estimates of HA are considered to be equivalent. However, few studies have examined their relationship, especially in healthy older individuals. We therefore examined the relationship between hippocampal qualitative atrophy scores and quantitative volumetric measurements in healthy older men. METHODS Ninety-seven healthy community-dwelling 65-70-year-old men underwent magnetic resonance imaging scanning. Hippocampal volumes were measured and adjusted for intracranial size. A validated 4-point visual rating scale was used to assess hippocampal atrophy. RESULTS There was a wide range of unadjusted hippocampal volumes among subjects (right: 2,582 to 5,196 mm3[mean 3,626 mm3; SD 465.5 mm3] and left: 2,111 to 4,580 mm3[mean 3,501 mm3; SD 439.5 mm3]), which was maintained following adjustment for intracranial size. However, only 9% of subjects were rated as having moderate or severe HA. Qualitative and quantitative measures were not significantly correlated (left hippocampus: rho = .07, P= .52; right hippocampus: rho = .10, P= .34). CONCLUSIONS This study shows that qualitative and quantitative indices of hippocampal atrophy in healthy older men are not equivalent. Small hippocampal volumes do not necessarily equate to hippocampal atrophy. [source] Isotropic Component Trace AnalysisJOURNAL OF NEUROIMAGING, Issue 3 2005Hitoshi Matsuzawa MD ABSTRACT A new method for analyzing diffusion tensor imaging (DTI) of the brain, based on a recently introduced algorithm, lambda chart analysis (LCA), is presented. Pretreatment of a given DTI data set with LCA, which effectively segregates isotropic and aniso tropic components, allows for total removal of the anisotropic component from the DTI data set. The remaining pure isotropic component can therefore be subjected to further analysis simi lar to that applied in the trace histogram method. Deconvolution of the trace function yielded 3 Gaussian elements. Remapping of these 3 deconvoluted isotropic elements back onto the 2-dimensional image plane provided anatomical correlates of each element. The algorithm, referred to here as isotropic com ponent trace analysis, can be used as a pictorial analytic tool, as well as a numerical analytical tool, for the noninvasive assess ment of isotropic parenchymal components. The presented method provides quantitative indices of certain parenchymal parameters with better clarity than currently available methods. A ready-to-use program, EZ-LCA, for this powerful method is provided (available at http://coe.bri.niigata-u.ac.jp). [source] Estimating the potential role of commercial over-harvesting in resource viability: a case study of five useful tree species in South AfricaLAND DEGRADATION AND DEVELOPMENT, Issue 3 2005C. M. Shackleton Abstract There is a growing commercialization of non-timber forest products (NTFPs) as a means of livelihood by rural communities throughout the developing world. This often occurs in the absence of any clear understanding of or guidelines regarding sustainable yields and ecological impacts, which may undermine the success of NTFP enterprises, especially from arid regions. This paper reports on the use of size class profiles and three quantitative indices to examine population profiles of five potentially useful tree species used as NTFPs in the semiarid lowveld of South Africa. We also contrast the population densities of the five tree species in 2003 with data from 1992. Low stem densities and population profiles indicated that three of the five species would preclude the establishment of NTFP enterprises based on their products. The other two species seem to have sufficient densities for some harvesting to take place, within an adaptive management framework. However, the longitudinal data indicated that the density of both these species had significantly declined over an eleven-year period, highlighting the need for appropriate management institutions. Additionally, the proportion of mature stems cut, and the degree of cutting per stem, had increased for all five species over the eleven years. The three quantitative indices of population stability were not correlated with one another, and hence provided a useful suite of measures sensitive to different aspects of size class profiles and their interpretation. Copyright © 2005 John Wiley & Sons, Ltd. [source] Can we use diffusion MRI as a bio-marker of neurodegenerative processes?BIOESSAYS, Issue 11-12 2008Yaniv Assaf Magnetic resonance imaging (MRI) is an imaging technique with a rapidly expanding application range. This methodology, which relies on quantum physics and substance magnetic properties, is now being routinely used in the clinics and medical research. With the advent of measuring functional brain activity with MRI (functional MRI), this methodology has reached a larger section of the neuroscience community (e.g. psychologists, neurobiologists). In the past, the use of MRI as a biomarker or as an assay to probe tissue pathophysiological condition was limited. However, with the new applications of MRI: molecular imaging, contrast-enhanced imaging and diffusion imaging, MRI is turning into a powerful tool for in vivo characterization of tissue pathophysiology. This review focuses on the diffusion MRI. Although it only measures the averaged Brownian translational motion of water molecules, using different analysis schemes, one can extract a wide range of quantitative indices that represent tissue morphology and compartmentalization. Statistical and visualization routines help to relate these indices to biologically relevant measures such as cell density, water content and size distribution. The aim of this review is to shed light on the potential of this methodology to be used in biological research. To that end, this review is intended for the non-MRI specialists who wish to pursue biological research with this methodology. We will overview the current applications of diffusion MRI and its relation to cellular biology of brain tissue. BioEssays 30:1235,1245, 2008. © 2008 Wiley Periodicals, Inc. [source] | |||||||||||||