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Quantitative Measures (quantitative + measure)
Selected AbstractsComparing Quantitative Measures of Erythema, Pigmentation and Skin Response using ReflectometryPIGMENT CELL & MELANOMA RESEARCH, Issue 5 2002Jennifer K. Wagner We measured a number of pigmentation and skin response phenotypes in a sample of volunteers (n=397) living in State College, PA. The majority of this sample was composed of four groups based on stated ancestry: African-American, European-American, Hispanic and East Asian. Several measures of melanin concentration (L*, melanin index and adjusted melanin index) were estimated by diffuse reflectance spectroscopy and compared. The efficacy of these measures for assessing constitutive pigmentation and melanogenic dose,response was evaluated. Similarly, several measures of erythema (a*, erythema index and adjusted erythema index) were compared and evaluated in their efficacy in measuring erythema and erythemal dose,response. We show a high correspondence among all of the measures for the assessment of constitutive pigmentation and baseline erythema. However, our results demonstrate that evaluating melanogenic dose,response is highly dependent on the summary statistic used: while L* is a valid measure of constitutive pigmentation it is not an effective measure of melanogenic dose,response. Our results also confirm the use of a*, as it is shown to be highly correlated with the adjusted erythema index, a more advanced measure of erythema based on the apparent absorbance. Diffuse reflectance spectroscopy can be used to quantify the constitutive pigmentation, melanogenic dose,response at 7 d and erythemal dose,response at both 24 h and 7 d postexposure. [source] Medial septal modulation of the ascending brainstem hippocampal synchronizing pathways in the freely moving ratHIPPOCAMPUS, Issue 1 2006Brian H. Bland Abstract Rats implanted with hippocampal recording electrodes were tested in a wheel-running apparatus under three conditions: (1) independent electrical stimulation of the medial septal nucleus (MS); (2) independent electrical stimulation of the posterior hypothalamic nucleus (PH); and (3) combined electrical stimulation of the MS and PH using pairings of two stimulation conditions, 7 or10 Hz stimulation of the MS, and a low- or high-intensity PH stimulation. Quantitative measures of running speed were taken, and hippocampal recordings were subjected to fast-Fourier transform analysis. Electrical stimulation of the PH induced wheel-running behavior; running speed and the accompanying hippocampus (HPC) theta frequency increased with increase in stimulation intensity. Electrical stimulation of the MS failed to induce wheel-running behavior despite the fact that HPC theta was induced at the frequency of the applied stimulation (7 and 10 Hz). Electrical stimulation of the MS reset the frequency of HPC theta induced by PH stimulation in both the upward and downward directions and increased theta power, while wheel-running speed was modulated in a downward direction only. © 2005 Wiley-Liss, Inc. [source] Interpreting sediment delivery processes using suspended sediment-discharge hysteresis patterns from nested upland catchments, south-eastern AustraliaHYDROLOGICAL PROCESSES, Issue 17 2009Hugh G. Smith Abstract In this study, suspended sediment concentration (SSC) and discharge (Q) hysteresis patterns recorded at the outlets of two nested upland catchments in south-eastern Australia were examined. Detailed monitoring of sediment flux was undertaken in a 1·64 km2 sub-catchment located within a 53·5 km2 catchment for which sediment yield was measured and the extent of incised channels mapped. The analysis of SSC,Q hysteresis patterns was supplemented by these additional datasets to contribute to the explanation of observed patterns. Clockwise SSC,Q hysteresis loops (with the suspended sediment peak leading the discharge peak) were recorded most frequently at both sites. This was attributed to initial rapid delivery of sediment from channel banks, the dominant sediment source in the sub-catchment and probably also for the catchment, in conjunction with remobilization of in-channel fine sediment deposits. Sediment exhaustion effects were considered to enhance clockwise hysteresis, with reduced SSC on the falling limb of event hydrographs. Pronounced exhaustion effects were observed on some multi-rise events, with subsequent flow peaks associated with much reduced sediment peaks. To compare SSC,Q hysteresis patterns between the two catchments, a dimensionless similarity function (SF) was derived to differentiate paired-event hysteresis patterns according to the extent of pattern similarity. This analysis, coupled with the other datasets, provided insight into the function of erosion and sediment delivery processes across the spatial scales examined and indicated the dependency of between-scale suspended sediment transfer on defined flow event scenarios. Quantitative measures of event SSC,Q hysteresis pattern similarity may provide a mechanism for linking the timing and magnitude of process response across spatial scales. This may offer useful insights into the between-scale linkage of dominant processes and the extent of downstream suspended sediment delivery. Copyright © 2009 John Wiley & Sons, Ltd. [source] Vascular alterations in the rabbit patellar tendon after surgical incisionJOURNAL OF ANATOMY, Issue 5 2001M. R. DOSCHAK Open incision of the patellar tendon (PT) is thought to promote acute vascular responses which ultimately result in an enhanced degree of tendon repair. Such a clinical procedure is commonly applied to patients with refractory tendinitis. The objective of this study was to quantify the vascular adaptations (both anatomical and physiological) to longitudinal incision of the PT, and the resultant effects on tendon organisation. Fifty-four New Zealand White rabbits were separated into 3 experimental groups and 2 control groups. Experimental groups underwent surgical incision of the right PT, and were assessed 3 d, 10 d and 42 d following injury; normal unoperated controls were evaluated at time zero, and sham-operated controls were evaluated at 3 d to control for the effects of incising the overlying skin. Quantitative measures of PT blood supply (blood flow, microvascular volume) and geometric properties of PT substance were obtained for each PT. Histomorphology was assessed to evaluate vascular remodelling and matrix organisation in the healing PT. Longitudinal open incision surgery of the PT led to rapid increases in both blood flow and vascular volume. The incision of overlying tissues alone (sham-operated) contributed to this measurable increase, and accounted for 36% and 42% of the elevated blood flow and vascular volume respectively at the 3 d interval. In the incised PT, blood flow significantly increased by 3 d compared with both time zero and sham-operated controls, and remained significantly elevated at the 10 d interval. Similarly, vascular volume of the incised PT increased at 3 d compared both with time zero and sham-operated controls. At the 10 d interval, the increase in vascular volume was greatest in the central PT substance. By 42 d both blood flow and vascular volume of the incised tendon had diminished, with only blood flow remaining significantly different from controls. In the contralateral limb, a significant neurogenically mediated vasodilation was measured in the contralateral PTs at both early time intervals, but was not seen by the later 42 d interval. With respect to PT geometric properties in the experimental animals, a larger PT results as the tendon matrix and blood vessels remodel. PT cross-sectional area increased rapidly by 3 d to 1·3 times control values, and remained significantly elevated at 42 d postinjury. Morphological assessments demonstrated the disruption of matrix organisation by vascular and soft tissue components associated with the longitudinal incisions. Substantial changes in matrix organisation persisted at 42 d after surgery. These findings suggest that open longitudinal incision of the PT increases the vascular supply to deep tendon early after injury. These changes probably arise through both vasomotor and angiogenic activity in the tissue. Since PT blood flow and vascular volume return towards control levels after 6 wk but structural features remain disorganised, we propose that vascular remodelling is more rapid and complete than matrix remodelling after surgical incision of the PT. [source] Reducing morphological variability of the cervical carotid artery in serial magnetic resonance imaging using a head and neck immobilization deviceJOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 1 2008Brian E. Chapman PhD Abstract Purpose To evaluate how well a head and neck immobilization device performed in reducing lumen morphology variability in repeated MR imaging of the carotid artery. Materials and Methods Quantitative measures of lumen and plaque characteristics may be important for longitudinal management of carotid atherosclerotic disease. However, quantitative measurements of the carotid artery are limited by their dependence on patient positioning, which can be quite variable. We created a head and neck immobilization device to reduce the variability of patient positioning during MR imaging of the carotid artery. In this article we describe the design and use of the immobilization device and assess how well its use reduced variability in vascular orientation and measurements of the carotid lumen cross-sectional area. Evaluation was based on 15 subjects who were repeatedly imaged without the immobilization device and 14 subjects who were repeatedly imaged with the device. Results Use of the immobilization device decreased the orientation variability from 9.1° to 5.3° (P = 0.0006) and the variability (defined as the standard deviation divided by the mean) of the cross-sectional area decreased from 0.24 to 0.18 (P = 0.04). Conclusion Using the immobilization device effectively reduces variability in repeated imaging of the carotid arteries. J. Magn. Reson. Imaging 2008;28:258,262. © 2008 Wiley-Liss, Inc. [source] Functional morphology and patterns of blood flow in the heart of Python regius,JOURNAL OF MORPHOLOGY, Issue 6 2009J. Matthias Starck Abstract Brightness-modulated ultrasonography, continuous-wave Doppler, and pulsed-wave Doppler-echocardiography were used to analyze the functional morphology of the undisturbed heart of ball pythons. In particular, the action of the muscular ridge and the atrio-ventricular valves are key features to understand how patterns of blood flow emerge from structures directing blood into the various chambers of the heart. A step-by-step image analysis of echocardiographs shows that during ventricular diastole, the atrio-ventricular valves block the interventricular canals so that blood from the right atrium first fills the cavum venosum, and blood from the left atrium fills the cavum arteriosum. During diastole, blood from the cavum venosum crosses the muscular ridge into the cavum pulmonale. During middle to late systole the muscular ridge closes, thus prohibiting further blood flow into the cavum pulmonale. At the same time, the atrio-ventricular valves open the interventricular canal and allow blood from the cavum arteriosum to flow into the cavum venosum. In the late phase of ventricular systole, all blood from the cavum pulmonale is pressed into the pulmonary trunk; all blood from the cavum venosum is pressed into both aortas. Quantitative measures of blood flow volume showed that resting snakes bypass the pulmonary circulation and shunt about twice the blood volume into the systemic circulation as into the pulmonary circulation. When digesting, the oxygen demand of snakes increased tremendously. This is associated with shunting more blood into the pulmonary circulation. The results of this study allow the presentation of a detailed functional model of the python heart. They are also the basis for a functional hypothesis of how shunting is achieved. Further, it was shown that shunting is an active regulation process in response to changing demands of the organism (here, oxygen demand). Finally, the results of this study support earlier reports about a dual pressure circulation in Python regius. J. Morphol., 2009. © 2008 Wiley-Liss, Inc. [source] Promoting Physical Activity in GirlsJOURNAL OF SCHOOL HEALTH, Issue 2 2005A Case Study of One School's Success ABSTRACT: This case study profiles one of 24 high schools that participated in a school-based, NIH-funded study to increase physical activity among high school girls. The case study school was one of 12 randomly assigned to the intervention group. The study intervention was based on the premise that a successful intervention is developed and tailored by teachers and staff to fit the context of their school. Intervention guidelines (Essential Elements) and the Coordinated School Health Program (CSHP) model were used to direct intervention activities for physical education, health education, school environment, school health services, faculty/staff health promotion, and family/community involvement. All girls at the case study school received the intervention. A team of school employees provided leadership to develop and implement the intervention in collaboration with a university project staff. Data collected over a two-year period were used to describe changes that occurred in each CSHP area. Key changes were made in the school environment, curricula, policies, and practices. Qualitative measures showed girls more involved in physical activity. Quantitative measures taken in eighth grade, and repeated with the same set of girls in ninth grade, showed increases in both moderate-to-vigorous physical activity (p = < .01) and vigorous physical activity (p = .04). Other schools can use this case to modify components of the CSHP model to increase physical activity among high school girls. [source] Atrazine increases the sodium absorption in frog (Rana esculenta) skinENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 2 2006Giuseppe Cassano Abstract The presence of atrazine in agricultural sites has been linked to the decline in amphibian populations. The efforts of the scientific community generally are directed toward investigating the long-term effect of atrazine on complex functions (reproduction or respiration), but in the present study, we investigated the short-term effect on the short-circuit current (ISC), a quantitative measure of the ion transport operated by frog (Rana esculenta) skin. Treatment with 5 ,M atrazine (1.08 mg/L) does not affect the transepithelial outfluxes of [14C]mannitol or [14C]urea; therefore, atrazine does not damage the barrier properties of frog skin. Atrazine causes a dose-dependent increase in the short-circuit current, with a minimum of 4.64 ± 0.76 ,A/cm2 (11.05% ± 1.22%) and a maximum of 12.7 ± 0.7 ,A/cm2 (35% ± 2.4%) measured at 10 nM and 5 ,M, respectively. An increase in ISC also is caused by 5 ,M ametryne, prometryn, simazine, terbuthylazine, or terbutryn (other atrazine derivatives). In particular, atrazine increases the transepithelial 22Na+ influx without affecting the outflux. Finally, stimulation of ISC by atrazine is suppressed by SQ 22536, H89, U73122, 2-aminoethoxydiphenyl borate, and W7 (blockers of adenylate cyclase, protein kinase A, phospholipase C, intracellular Ca2+ increase, and calmodulin, respectively), whereas indomethacin and calphostin C (inhibitors of cyclooxygenase and protein kinase C, respectively) have no effect. [source] Astrocytes in the hippocampus of patients with temporal lobe epilepsy display changes in potassium conductancesEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 6 2000Stefan Hinterkeuser Abstract Functional properties of astrocytes were investigated with the patch-clamp technique in acute hippocampal brain slices obtained from surgical specimens of patients suffering from pharmaco-resistant temporal lobe epilepsy (TLE). In patients with significant neuronal cell loss, i.e. Ammon's horn sclerosis, the glial current patterns resembled properties characteristic of immature astrocytes in the murine or rat hippocampus. Depolarizing voltage steps activated delayed rectifier and transient K+ currents as well as tetrodotoxin-sensitive Na+ currents in all astrocytes analysed in the sclerotic human tissue. Hyperpolarizing voltages elicited inward rectifier currents that inactivated at membrane potentials negative to -130 mV. Comparative recordings were performed in astrocytes from patients with lesion-associated TLE that lacked significant histopathological hippocampal alterations. These cells displayed stronger inward rectification. To obtain a quantitative measure, current densities were calculated and the ratio of inward to outward K+ conductances was determined. Both values were significantly smaller in astrocytes from the sclerotic group compared with lesion-associated TLE. During normal development of rodent brain, astroglial inward rectification gradually increases. It thus appears reasonable to suggest that astrocytes in human sclerotic tissue return to an immature current pattern. Reduced astroglial inward rectification in conjunction with seizure-induced shrinkage of the extracellular space may lead to impaired spatial K+ buffering. This will result in stronger and prolonged depolarization of glial cells and neurons in response to activity-dependent K+ release, and may thus contribute to seizure generation in this particular condition of human TLE. [source] Common birds facing global changes: what makes a species at risk?GLOBAL CHANGE BIOLOGY, Issue 1 2004Romain Julliard Abstract Climate change, habitat degradation, and direct exploitation are thought to threaten biodiversity. But what makes some species more sensitive to global change than others? Approaches to this question have relied on comparing the fate of contrasting groups of species. However, if some ecological parameter affects the fate of species faced with global change, species response should vary smoothly along the parameter gradient. Thus, grouping species into few, often two, discrete classes weakens the approach. Using data from the common breeding bird survey in France , a large set of species with much variability with respect to the variables considered , we show that a quantitative measure of habitat specialization and of latitudinal distribution both predict recent 13 year trends of population abundance among 77 terrestrial species: the more northerly distributed and the more specialized a species is, the sharper its decline. On the other hand, neither hunting status, migrating strategy nor body mass predicted population growth rate variation among common bird species. Overall, these results are qualitatively very similar to the equivalent relationships found among the British butterfly populations. This constitutes additional evidence that biodiversity in Western Europe is under the double negative influence of climate change and land use change. [source] Spectral Welfare Cost FunctionsINTERNATIONAL ECONOMIC REVIEW, Issue 2 2001Christopher Otrok If preferences are not time-separable, economic agents care not only about the magnitude of fluctuations in consumption but also about the persistence and other temporal characteristics of those fluctuations. This paper extends and develops the theory of spectral utility functions, which measure utility frequency by frequency, to illustrate the interaction between consumption volatility and time-non-separable preferences. To highlight the economic implications of the interaction, spectral welfare cost functions are developed to provide a quantitative measure of the importance to economic agents of the temporal delivery of consumption volatility. [source] Valence and extra-valence orbitals in main group and transition metal bondingJOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 1 2007C. R. Landis Abstract We address the issue first raised by Maseras and Morokuma with regard to the questionable treatment of empty p-orbitals in the algorithm for natural atomic/bond orbitals (NAOs, NBOs) and associated natural population analysis. We quantify this issue in terms of the numerical error (root-mean-square density deviation) resulting from the two alternative treatments of empty p-sets, leading to distinct NAOs, atomic charges, and idealized Lewis structural representations. Computational application of this criterion to a broad spectrum of main group and transition group species (employing both single- and multi-structure resonance models) reveals the interesting general pattern of (i) relatively insignificant differences for normal-valent species, where a single resonance structure is usually adequate, but (ii) clear superiority of the standard NAO algorithm for hypervalent species, where multi-resonance character is pronounced. These comparisons show how the divisive issue of "valence shell expansion" in transition metal bonding is deeply linked to competing conceptual models of hypervalency (viz., "p-orbital participation" in skeletal hybridization vs. 3c/4e resonance character). The results provide a quantitative measure of superiority both for the standard NAO evaluation of atomic charges as well as the general 3c/4e (A: B-C , A-B :C resonance) picture of main- and transition-group hypervalency. © 2006 Wiley Periodicals, Inc. J Comput Chem, 2007 [source] Force Transmissibility Performance of Parallel ManipulatorsJOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 11 2003Wen-Tung Chang In this paper, a new force transmission index called the mean force transmission index (MFTI) is proposed, and the force transmissibility analysis procedure is established for parallel manipulators. The MFTI is an extended definition of the force transmission index (FTI) introduced by the authors previously. It is shown that the FTI is a function of the input velocity ratio (IVR) for a multi-DOF mechanism of the same configuration. To represent the force transmissibility by a definite value, the MFTI is defined as the mean value of the normalized FTIs function over the whole range of the IVR. The force transmissibility analysis of two planar parallel manipulators is illustrated using the MFTI method. The result is compared with that of the Jacobian matrix method and the joint force index (JFI) method. It shows that, especially for symmetric parallel manipulators, an approximate inverse-proportionality relationship exists between the JFI and MFTI, and between the maximum input torque/force and MFTI. It is concluded that the MFTI can be used as a quantitative measure of the force transmissibility performance for parallel manipulators. In the end, a design optimization problem is studied by taking the global force transmission index as the objective function. © 2003 Wiley Periodicals, Inc. [source] Stiffness characteristics and kinematics analysis of two-link elastic underactuated manipulatorsJOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 4 2002Jian S. Dai This article investigates the stiffness characteristics of two-link underactuated manipulators, examines the effect on the torque resulting in the passive joint, and develops a stiffness model in analysing the behaviors of the manipulators. The kinematic analysis leads to the trajectory of the end-effector, which is associated with the stiffness coupled between the active and passive joints and with the constraint forces, and the kinematic coupling is shown in the angular displacement and in the resulting torque. The stiffness characteristics are illustrated in the directional stiffness mapping, which gives a quantitative measure of stiffness with respect to displacement direction. © 2002 Wiley Periodicals, Inc. [source] Preliminary evaluation of a scale to assess cognitive function in adults with Down's syndrome: the Prudhoe Cognitive Function TestJOURNAL OF INTELLECTUAL DISABILITY RESEARCH, Issue 3 2003D. W. K. Kay Abstract Background In the clinical diagnosis of dementia in Down's syndrome (DS), it may be difficult to distinguish between cognitive deterioration and the various degrees of pre-existing intellectual disability (ID). Serial measurements of both cognitive function and behaviour are required. The aim of the present study was to evaluate the performance of non-demented adults with DS on a subject-directed instrument, the Prudhoe Cognitive Function Test (PCFT), preliminary to its serial use in a prospective study. Methods From 1985 to 1986, 85 non-demented hospitalized adults with DS were interviewed using the PCFT. The Adaptive Behavior Scale (ABS) was administered to the carers. The subjects' levels of ID (graded from mild through moderate, severe and profound to untestable) were based on their scores on the Stanford,Binet Intelligence Scale, as reported in the medical records, and the relationship between level of disability and performance on the PCFT and ABS, and their respective domains, was examined. Results Both scales produced a wide range of scores and the correlation between them was highly significant. Both scales correlated highly significantly with the degree of ID, but more subjects with high levels (i.e. profound to untestable) of disability obtained very low or zero scores on the PCFT and its domains than on the ABS. Conclusions The PCFT provides a reliable quantitative measure of cognitive function in subjects with DS, and could be a useful adjunct to the diagnosis of dementia in prospective studies. However, the almost uniformly low scores obtained by those with high levels of ID suggests that its power to detect cognitive decline will be limited to those who are less disabled, while the ABS may be more useful than the PCFT in detecting deterioration in people with profound ID. [source] Game theoretic approach to multiobjective designs: Focus on inherent safetyAICHE JOURNAL, Issue 1 2006Anjana Meel Abstract A method for designing processes that are inherently safer,with the primary focus on disturbances having the potential for unbounded hazardous responses,is introduced. In cases where safety is not threatened (as in isothermal fermentation reactors), but product quality can rapidly degrade, this method provides designs that ensure high product quality (as in pharmaceutical processes). Using game theory, the method accounts for the trade-offs in profitability, controllability, safety and/or product quality, and flexibility. For nonlinear processes that are hard to control; that is, have an unstable and/or nonminimum-phase steady state, over a wide range of operating conditions, extended bifurcation diagrams are introduced. When a steady state is nonminimum phase, the process may exhibit inverse response. The steady states of processes are classified on the basis of instability and nonminimum-phase behavior to segregate the operating regimes into distinct zones. Locally optimal designs, one corresponding to each zone, are obtained first. These are compared with other locally optimal designs at alternate operating conditions, and/or process reconfigurations, to obtain the globally optimal design using game theory. Four indices,profitability, controllability, safety and/or product quality, and flexibility,characterize the optimality of a design. A novel index for safe operation and/or product quality at a steady state is formulated as a function of the eigenvalues of the Jacobian of the process model and the Jacobian of the process zero dynamics, providing a quantitative measure of instability and nonminimum-phase behavior. The application of the proposed method to an isothermal, continuous stirred-tank reactor (CSTR) with van der Vusse reactions, an exothermic CSTR, and an anaerobic fermentor with substrate and product inhibition is presented. © 2005 American Institute of Chemical Engineers AIChE J, 2006 [source] Rapid quantitative bioassay of osteoinductionJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 3 2000Huston Davis Adkisson We developed a reproducible, relatively rapid bioassay that quantitatively correlates with the osteoinductive capacity of demineralized bone matrix obtained from human long bones. We have found that Saos human osteosarcoma cells proliferate in response to incubation with demineralized bone matrix and that an index of this proliferative activity correlates with demineralized bone matrix-induced osteogenesis in vivo. The bioassay (Saos cell proliferation) had an interassay coefficient of variation of 23 ± 2% and an intra-assay cocfficient of 11 ± 1%. Cell proliferation was normalized to a standard sample of demineralized bone matrix with a clinically high osteoinductive capacity, which was assigned a value of one. The Saos cell proliferation for each sample was related to the standard and assigned a value placing it into thc low (0.00-0.39), intermediate (0.40-0.69). or high (0.70-1.49) osteoinductivc index group. Osteoinduction of human demineralized bone matrix was quantitated by expressing new bone formation as a function of the total bone volume (new bone plus the demineralized bone powder). The demineralized bone matrix was placed in pouches formed in the rectus abdominis muscles of athymic rats, and endochondral bone formation was assessed at 35 days following implantation, when marrow spaces in the ossicles were formed by new bone bridging the spaces between demineralized bone matrix particles. The proliferative index correlated with the area of new bone formation in histological sections ol the newly formed ossicles. When the proliferative index (the osteoinductive index) was divided into low, intermediate. and high groups, the correlation between it and new bone formation (osteoinduction) was 0.850 (p < 0.0005) in 25 samples of demineralized bone matrix. There was no overlap in the osteoinduction stimulated between the samples with low and high osteoinductive indices. We conclude that the proliferation assay is useful for the routine screening of bone allograft donors for osteoinductivc potential. Furthermore, the two-dimensional area of new bone formation. as it relates to total new bone area, is a quantitative measure of osteoinduction. [source] Quantitative comparison of the cytocidal effect of seven macrolide antibiotics on human periodontal ligament fibroblastsJOURNAL OF PERIODONTAL RESEARCH, Issue 4 2002Noriko Maizumi The cytocidal effect of seven macrolide antibiotics on human periodontal ligament fibroblasts (Pel cells) was studied. Pel cells were exposed for 48 h to erythromycin (EM), clarithromycin (CAM), roxithromycin (RXM), azithromycin (AZM), josamycin (JM), midecamycin (MDM), and rokitamycin (RKM), and allowed to form colonies. The cytocidal effect of the macrolides was measured as a decrease in colony-forming efficiency and was found to increase with the concentration. To obtain a quantitative measure of the cytocidal effect, the LD50, i.e. the concentration that decreases colony-forming efficiency 50% relative to control cells, was extrapolated from the concentration-response curves. The rank of the macrolides according to their cytocidal effect (LD50) was RKM > RXM > CAM > AZM > JM > MDM , EM. RKM, RXM, CAM, AZM, and JM were at least 1.7,12.2 times more cytocidal than MDM or EM. When extrapolated from the concentration-response curves, the relative survival of the Pel cells exposed to each of the macrolides at the MIC90 concentrations for periodontopathic bacteria was estimated to be: ,,53.8% for RKM, , 92.7% for RXM, , 94.6% for CAM, , 97.1% for AZM, and , 86.2% for EM. The effect of the antibiotics on the mRNA expression of alkaline phosphatase (ALP) and type I procollagen (COL) was examined in Pel cells exposed for 48 h to RXM, CAM, AZM, and EM, which exhibited strong, moderate, and weak cytocidal activity. The constitutive levels of both ALP and COL mRNA were retained in cells exposed to RXM at ,3 ,M, CAM at ,10 ,M, and AZM or EM at ,3 ,M. The MIC90 against periodontopathic bacteria is ,4.8 ,M for RXM, 5.3 ,M for CAM, 2.7 ,M for AZM, and 21.8 ,M for EM. These results suggest that topical administration of CAM or AZM to the gingival crevice at their MIC90 concentration for periodontopathic bacteria would have little adverse effect on the growth and differentiation of the periodontal ligament. It is important to note, however, that these findings have yet to be extrapolated to in vivo conditions. [source] Sources of Dietary Fluoride Intake in 6,7-Year-Old English Children Receiving Optimally, Sub-optimally, and Non-fluoridated waterJOURNAL OF PUBLIC HEALTH DENTISTRY, Issue 4 2006Fatemeh V. Zohouri BSc, RPHNutr Abstract Objectives:Due to increased consumption of pre-packaged drinks, tap water may no longer be the principal source of water intake and consequently fluoride intake. Little is known about the importance of solid foods as fluoride sources and how the relative contribution of foods/drinks to fluoride intake is affected by residing in fluoridated or non-fluoridated areas. This study investigated the relative contributions of different dietary sources to dietary fluoride intake and compared this in children residing in optimally artificially fluoridated, sub-optimally artificially fluoridated, and non-fluoridated areas. Methods:Thirty-three healthy children aged 6 years were recruited from fluoridated and non-fluoridated communities and categorised into three groups based on fluoride content of home tap water: optimally fluoridated (<0.7 mgF/L), sub-optimally fluoridated (>0.3 to <0.7 mgF/L) and non-fluoridated (<0.3 mgF/L) drinking water. A 3-day dietary diary collected dietary information. Samples of foods/drinks consumed were collected and analyzed for fluoride content. Results:Drinks provided 59%, 55% and 32% of dietary fluoride intake in optimally, sub-optimally and non-fluoridated areas respectively. Tap water, fruit squashes and cordials (extremely sweet non-alcoholic fruit flavoured drink concentrates) prepared with tap water, as well as cooked rice, pasta and vegetables were important sources of fluoride in optimally and sub-optimally fluoridated areas. Carbonated soft drinks and bread were the most important contributors to dietary fluoride intake in the non-fluoridated area. Conclusion:The main contributory sources to dietary fluoride differ between fluoridated and non-fluoridated areas. Estimating total fluoride intake from levels of fluoride in tap water alone is unlikely to provide a reliable quantitative measure of intake. Studies monitoring dietary fluoride exposure should consider intake from all foods and drinks. [source] Experimental and statistical analysis methods for peptide detection using surface-enhanced Raman spectroscopyJOURNAL OF RAMAN SPECTROSCOPY, Issue 3 2008Breeana L. Mitchell Abstract Surface-enhanced Raman spectroscopy (SERS) has the potential to make a significant impact in biology research due to its ability to provide information orthogonal to that obtained by traditional techniques such as mass spectrometry (MS). While SERS has been well studied for its use in chemical applications, detailed investigations with biological molecules are less common. In addition, a clear understanding of how methodology and molecular characteristics impact the intensity, the number of peaks, and the signal-to-noise of SERS spectra is largely missing. By varying the concentration and order of addition of the SERS-enhancer salt (LiCl) with colloidal silver, we were able to evaluate the impact of these variables on peptide spectra using a quantitative measure of spectra quality based on the number of peaks and peak intensity. The LiCl concentration and order of addition that produced the best SERS spectra were applied to a panel of synthetic peptides with a range of charges and isoelectric points (pIs) where the pI was directly correlated with higher spectral quality. Those peptides with moderate to high pIs and spectra quality scores were differentiated from each other using the improved method and a hierarchical clustering algorithm. In addition, the same method and algorithm was applied to a set of highly similar phosphorylated peptides, and it was possible to successfully classify the majority of peptides on the basis of species-specific peak differences. Copyright © 2008 John Wiley & Sons, Ltd. [source] Estimating the audience level for library resourcesJOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE AND TECHNOLOGY, Issue 13 2008Edward T. O'Neill WorldCat, OCLC's bibliographic database, identifies books and the libraries that hold them. The holdings provide detailed information about the type and number of libraries that have acquired the material. Using this information, it is possible to infer the type of audience for which the material is intended. A quantitative measure, the audience level, is derived from the types of libraries that have selected the resource. The audience level can be used to refine discovery, analyze collections, advise readers, and enhance reference services. [source] Development of a quantitative tool for the comparison of the prebiotic effect of dietary oligosaccharidesLETTERS IN APPLIED MICROBIOLOGY, Issue 4 2003R. Palframan Abstract Aims: To develop a quantitative equation [prebiotic index (PI)] to aid the analysis of prebiotic fermentation of commercially available and novel prebiotic carbohydrates in vitro, using previously published fermentation data. Methods: The PI equation is based on the changes in key bacterial groups during fermentation. The bacterial groups incorporated into this PI equation were bifidobacteria, lactobacilli, clostridia and bacteroides. The changes in these bacterial groups from previous studies were entered into the PI equation in order to determine a quantitative PI score. PI scores were than compared with the qualitative conclusions made in these publications. In general the PI scores agreed with the qualitative conclusions drawn and provided a quantitative measure. Conclusions: The PI allows the magnitude of prebiotic effects to be quantified rather than evaluations being solely qualitative. Significance and Impact of the Study: The PI equation may be of great use in quantifying prebiotic effects in vitro. It is expected that this will facilitate more rational food product development and the development of more potent prebiotics with activity at lower doses. [source] Price adjustment in Italy: evidence from micro producer and consumer pricesMANAGERIAL AND DECISION ECONOMICS, Issue 2-3 2010Silvia Fabiani This paper investigates the behaviour of consumer and producer prices in Italy using micro data. The frequency of price changes is computed in order to obtain a quantitative measure of the unconditional degree of price rigidity at both the consumption and the production stage. On average, producer prices tend to remain unchanged for around 6 months, whereas consumer prices exhibit a longer duration, of 10 months. A comparison of the price behaviour of similar items confirms that prices are more flexible at the production stage. Prices, however, are not adjusted uniformly across sectors. The duration of producer prices is less for food and non-energy intermediate products and greater for non-food consumer and investment goods. At the consumption stage, price spells are longer for non-energy industrial goods and services, much shorter for energy products. In exploring the possible reasons for the differences, we observe that a higher share of labour in total costs is associated with lower frequency of price adjustment. Moreover, the structure and functioning of the retail sector in Italy may slow price adjustment at the consumption stage, together with other specific economic factors that affect mainly consumer price behaviour, such as menu costs and attractive pricing policies. Copyright © 2009 John Wiley & Sons, Ltd. [source] FLIPPER RUBBING BEHAVIORS IN WILD BOTTLENOSE DOLPHINS (TURSIOPS ADUNCUS)MARINE MAMMAL SCIENCE, Issue 4 2006Mai Sakai Abstract "Flipper rubbing" behavior was quantitatively analyzed in wild Indo-Pacific bottlenose dolphins (Tursiops aduncus) around Mikura Island, Tokyo, Japan. We observed two types of flipper rubbing: (1) F-B rubbing; one dolphin (Rubber) rubbed its flipper over various parts of a partner's (Rubbee) body, and (2) F-F rubbing; both dolphins rubbed each other's anterior flipper edge in alternating shifts. F-B rubbings tended to be initiated by the Rubbee and were terminated by the Rubber. The Rubbee often moved actively its body part that was in contact with the Rubber's flipper, and assumed side-up, upside-down, or other postures while the Rubber remained horizontal in most cases. These facts suggest that the Rubbee engaged in F-B rubbing more actively than the Rubber, and might receive some benefit from the frictional contact during F-B rubbing. Dolphins often switched their roles as Rubber and Rubbee between episodes of flipper rubbing bout. Adults and sub-adults exchanged F-B rubbing and F-F rubbing most often with individuals of the same sex in the same age class. F-B rubbing was frequent in mother-and-calf dyads. Our results suggest that flipper rubbing is an affiliative behavior which could be a quantitative measure of social relationships among individuals of this species in future studies. [source] The Infant Feeding Intentions scale demonstrates construct validity and comparability in quantifying maternal breastfeeding intentions across multiple ethnic groupsMATERNAL & CHILD NUTRITION, Issue 3 2010Laurie A. Nommsen-Rivers Abstract Research tools that are comparable across ethnic groups are needed in order to understand sociodemographic disparities in breastfeeding rates. The Infant Feeding Intentions (IFI) scale provides a quantitative measure of maternal breastfeeding intentions. IFI score ranges from 0 (no intention to breastfeed) to 16 (very strong intentions to fully breastfeed for 6 months). The objective of this study was to examine intra- and inter-ethnic validity of the IFI scale. The IFI scale was administered to 218 white non-Hispanic, 75 African-American, 80 English-speaking Hispanic, 62 Spanish-speaking Hispanic and 64 Asian expectant primiparae. Participants were asked their planned duration of providing breast milk as the sole source of milk (full breastfeeding). The IFI scale was examined for intra-ethnic internal consistency and construct validity and for inter-ethnic comparability. For all five ethnic categories, principal component analysis separated the scale into the same two factors: intention to initiate breastfeeding and intention to continue full breastfeeding. Across ethnic categories, the range in Cronbach's alpha was 0.70,0.85 for the initiation factor and 0.90,0.93 for the continuation factor. Within each ethnic category, IFI score increased as planned duration of full breastfeeding increased (P < 0.0001 for all). Within the planned duration categories of <1, 1,3, 3,6 and ,6 months, the median IFI score by ethnic category ranged from (low,high) 5,8, 9,10, 12,14 and 16,16, respectively. The IFI scale provides a valid measure of breastfeeding intentions in diverse populations of English- and Spanish-speaking primiparae, and may be a useful tool when researching disparities in breastfeeding practices. [source] MODEL UNCERTAINTY AND ITS IMPACT ON THE PRICING OF DERIVATIVE INSTRUMENTSMATHEMATICAL FINANCE, Issue 3 2006Rama Cont Uncertainty on the choice of an option pricing model can lead to "model risk" in the valuation of portfolios of options. After discussing some properties which a quantitative measure of model uncertainty should verify in order to be useful and relevant in the context of risk management of derivative instruments, we introduce a quantitative framework for measuring model uncertainty in the context of derivative pricing. Two methods are proposed: the first method is based on a coherent risk measure compatible with market prices of derivatives, while the second method is based on a convex risk measure. Our measures of model risk lead to a premium for model uncertainty which is comparable to other risk measures and compatible with observations of market prices of a set of benchmark derivatives. Finally, we discuss some implications for the management of "model risk." [source] Improvement in a quantitative measure of bradykinesia after microelectrode recording in patients with Parkinson's disease during deep brain stimulation surgeryMOVEMENT DISORDERS, Issue 5 2006Mandy Miller Koop MS Abstract It is widely accepted that patients with Parkinson's disease experience immediate but temporary improvement in motor signs after surgical implantation of subthalamic nucleus (STN) deep brain stimulating electrodes before the electrodes are activated, although this has never been formally studied. Based on anecdotal observations that limb mobility improved just after microelectrode recording (MER) during deep brain stimulation (DBS) procedures, we designed a prospective study to measure upper extremity bradykinesia using a quantitative measure of angular velocity. Measurements were made pre- and post-MER and during intraoperative DBS. Analysis of 98 STN DBS procedures performed on 61 patients showed that MER did not create adverse clinical symptoms despite concerns that MER increases morbidity. Quantitative upper extremity bradykinesia improved after MER alone, and further improvement was seen during intraoperative DBS. Electrophysiological data from each case were then compared to the improvement in bradykinesia post-MER alone and a significant correlation was found between the improvement in arm bradykinesia, the number of passes through the STN with somatosensory driving, and also with the number of arm cells with somatosensory driving in the STN, but not with total number of passes, total number of passes through the STN, or total number of cells with somatosensory driving in the STN. This study demonstrates that there is a significant improvement in upper extremity bradykinesia just after MER, before inserting or activating the DBS electrode in patients with Parkinson's disease who undergo STN DBS. © 2006 Movement Disorder Society [source] Measuring performance status in pediatric patients with brain tumors,experience of the HIT-GBM-C protocol,,PEDIATRIC BLOOD & CANCER, Issue 3 2010Johannes E. A. Wolff MD Abstract Background Measuring the quality of life or performance status in pediatric neurooncology has proven a challenge. Here, we report in a treatment protocol for pediatric patients with high-grade glioma and diffuse intrinsic pontine glioma. Procedure The Fertigkeitenskala Münster,Heidelberg (FMH) is a 56-item quantitative measure of health status. The number of yes answers is transformed to age-dependent percentiles. Physicians were also asked the patients' health status by their own judgment on a 1,5 scale: normal, mild handicap, age-normal activity severely reduced but patient not in bed, in bed, and in ICU. Results Assessments were available from 50 of 97 eligible patients. For 22 patients both questionnaire and the physicians score obtained. At the beginning of the treatment, only 5 patients scored over 40 FMH%, and 4 of these survived. Of 16 patients who initially scored less than 40 FMH%, 15 died. During later assessments, most FMH measures became gradually worse. FMH scores improved in three patients. The physician's judgment was documented at diagnosis and during treatment (n,=,50). Per physician, 22% of the patients were normal before chemotherapy, decreasing to 16% in the middle of the protocol. At diagnosis only 16% of patients had severely reduced activity, which increased to 30.6% in the middle of the protocol. The FMH% correlated well with the physicians' judgments (P,<,0.005). Conclusion The FMH scale is easily obtained and provides a valid assessment of health status. Patients with poor performance at diagnosis had a poorer prognosis. Pediatr Blood Cancer. 2010;55:520,524. © 2010 Wiley-Liss, Inc. [source] Evolution of structure in the softening/melting regime of miscible polymer mixingPOLYMER ENGINEERING & SCIENCE, Issue 6 2001Heidi E. Burch Structure development in the softening/melting processing regime is investigated using the model miscible blend poly(styrene-co-acrylonitrile) (SAN)/poly(methyl methacrylate) (PMMA). Feed materials of four different particle sizes are compounded to study their effects upon structure development. Fourier-transform infrared spectroscopy is used to help determine the normalized sample variance, a quantitative measure of mixing. The normalized sample variance is determined both as a function of sample size and as a function of feed particle size in an effort to assess the characteristic size scale(s) present in the blend at short mixing times. Results of these experiments indicate that the distribution of size scales in the softening regime is at least bimodal. Optical examination of pigmented mixtures reveals that this multimodality is due to the operation of the Scott/Macosko sheeting mechanism of morphology development, which was previously shown to be active in immiscible blends. This is contrary to the currently accepted laminar mixing model, which postulates the formation of a striated mixture while ignoring the softening/melting regime. [source] Application of cycling index and input-output environs for interpretation of nutrient flows in mixed rice-beef production systems in JapanANIMAL SCIENCE JOURNAL, Issue 3 2009Yusuke TABATA ABSTRACT The objective of the present study was to apply two methods developed in ecology, the cycling index and input-output environs, to interpret nutrient flows in mixed rice-beef production systems. The cycling index (CI) was a quantitative measure of nutrient cycling. It was defined as the proportion of cycled nutrients to the total amount of nutrient flows. On the other hand, the input-output environs provide a quantitative distribution on a particular input or output. In this study, these methods were applied to the nutrient flows in the mixed rice-beef production systems in Japan. The results of CI provided information on the effects of nutrient cycling on the efficient conversion of nutrient imports to nutrient export. The results of input-output environs indicated that the indices represent indirect effects provided by the interaction between rice and beef production. In conclusion, these methods indicated new findings on nutrient utilization in the systems. The results of this study implied the further applicability of these two methods to the study of nutrient flows in mixed crop-animal production systems. [source] | ||||||||||||||||||||||||||||||||||||||||||||||