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Direct Measure (direct + measure)
Selected AbstractsExpectations Formation and Business Cycle Fluctuations: An Empirical Analysis of Actual and Expected Output in UK Manufacturing, 1975,1996OXFORD BULLETIN OF ECONOMICS & STATISTICS, Issue 4 2000Kevin Lee Direct measures of expectations, derived from survey data, are used in a Vector Autoregressive (VAR) model of actual and expected output in eight industries in the UK manufacturing sector. No evidence is found with which to reject rationality in the derived expectations series when measurement error is appropriately taken into account. The VAR analysis illustrates the importance of intersectoral interactions and business confidence in explaining the time profile of industrial outputs, examines the mechanisms by which shocks are propagated across sectors and over time and investigates the relative importance of sectoral and aggregate shocks of different types. [source] Reduction rate of lymph node metastasis as a significant prognostic factor in esophageal cancer patients treated with neoadjuvant chemoradiation therapyDISEASES OF THE ESOPHAGUS, Issue 2 2007S. Aiko SUMMARY., Tumor regression is used widely as a measure of tumor response following radiation therapy or chemoradiation therapy (CRT). In cases of esophageal cancer, a different pattern of tumor shrinkage is often observed between primary tumors and metastatic lymph nodes (MLNs). Regression of MLNs surrounded by normal tissue may be a more direct measure of the response to CRT than regression of a primary tumor as exfoliative mechanical clearance does not participate in shrinkage of MLNs. In this study we evaluated the significance of the reduction rate (RR) of MLNs as a prognostic factor in esophageal cancer patients treated with neoadjuvant CRT. Forty-two patients with marked MLNs were selected from 93 patients with esophageal carcinoma who had received neoadjuvant CRT. The RRs of the primary tumor and the MLNs were calculated from computed tomography scans. In 20 patients, surgical resection was carried out following CRT. Univariate analysis was used to determine which of the following variables were related to survival: size of the primary tumor and MLNs; RRs of both lesions; degree of lymph node (LN) metastasis; clinical stage; and surgical resection. Multivariate analysis was then performed to assess the prognostic relevance of each variable. The primary tumor was larger than the MLNs in 69% of patients before CRT and in 40% of patients after CRT. In 79% of the patients, the RR of the primary tumor was greater than the RR of the MLNs. The results of the univariate analyses showed that a high RR of the MLNs and surgical resection after CRT were associated with significantly improved survival. The multivariate analysis demonstrated that the RR of MLNs had the strongest influence on survival. The RR of LN metastasis should be evaluated as an important prognostic predictor in patients with marked LN metastasis of esophageal cancer treated with CRT. [source] Economic Sentiment and Yield Spreads in EuropeEUROPEAN FINANCIAL MANAGEMENT, Issue 2 2008Eva Ferreira G12; E43 Abstract According toHarvey (1988), the forecasting ability of the term spread on economic growth is due to the fact that interest rates reflect investors' expectations about the future economic situation when deciding their plans for consumption and investment. Past literature has used ex post data on output or consumption growth as proxies for their expected value. In this paper, we employ a direct measure of economic agents' expectations, the Economic Sentiment Indicator elaborated by the European Commission, to test this hypothesis. Our results indicate that a linear combination of European yield spreads explains a surprising 93.7\% of the variability of the Economic Sentiment Indicator. This ability of yield spreads to capture economic agent expectations may be the actual reason for the predictive power of yield spreads about future business cycle. [source] Decline in the quality of suspended fine particulate matter as a food resource for chironomids downstream of an urban areaFRESHWATER BIOLOGY, Issue 5 2004Emma J. Rosi-MarshallArticle first published online: 16 APR 200 Summary 1. Urbanization and its associated contamination could degrade the quality of suspended fine particulate organic matter (SFPM) (20 ,m to 1 mm) as a food resource for aquatic insects. SFPM was collected at four sites along the main stem of the Chattahoochee River, which drains metropolitan Atlanta at base and high flow during four seasons. 2. Composition of SFPM was estimated using measures conventionally associated with food quality: bacteria, N/C ratio, caloric content, % inorganic, and % lipids, and metal (Cd, Cu, Pb, and Zn) concentration. In SFPM collected during base flow, % inorganic matter, calories, Cu, Pb, and Zn concentrations increased with cumulative permitted wastewater treatment discharge (an indicator of extent of urbanization upstream). In SFPM samples collected during high flow, % diatoms, Cu, Pb and Zn concentrations increased with urbanization. 3. A growth assay was used as an integrated and direct measure of SFPM quality as a food resource. The instantaneous growth rate (IGR) of chironomids fed SFPM collected during base flow declined downstream of the city. IGRs of chironomids fed SFPM collected at all sites during high flow were as low as the lowest IGR measured during base flow. 4. Insects fed SFPM collected from the Chattahoochee River had IGRs only 20% of those of chironomids fed SFPM collected from the Little Tennessee River, a relatively undisturbed river in North Carolina. The mortality rate of chironomids fed SFPM was not different among sites or rivers. While the decline in SFPM quality in the Chattahoochee River is probably attributable to some aspect of urbanization, the decline was not related to conventional measures of food quality or metal contamination. [source] FxJj43: A window into a 1.5-million-year-old palaeolandscape in the Okote Member of the Koobi Fora Formation, northern KenyaGEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 4 2002Nicola Stern FxJj43 differs from most other archaeological sites preserved in the Okote Member of the Koobi Fora Formation in ways that make it especially suited to the problem of clarifying the behavioral information encapsulated in fine time-lines. At this site in northern Kenya, a continuous strip of outcrops, preserving a set of interlocking landforms, can be traced around the modern erosion front for more than half a kilometer. The characteristics and three-dimensional geometries of the beds making up these outcrops show that they have preserved the southern bank, levee, and floodplain of a westerly flowing sandy channel. Both stone tools and animal bones are strewn across the eroding surfaces of these outcrops, and excavations show that they are derived from a narrow stratigraphic horizon immediately overlying the volcanic ash at the base of the sequence. The blue tuff, and the archaeological horizon that overlies it, have been dated using the 40Ar- 39Ar method on single crystals of alkali feldspar. Although there is no direct measure of how long it took the archaeological horizon to accumulate, it probably accumulated over a time span of 102,103 years. Thus the locality may be used to test the proposition that the analysis of archaeological debris from fine-time lines will help to resolve ambiguities in the interpretation of early Pleistocene archaeological assemblages. © 2002 Wiley Periodicals, Inc. [source] Infant health production functions: what a difference the data makeHEALTH ECONOMICS, Issue 7 2009Nancy E. Reichman Abstract We examine the extent to which infant health production functions are sensitive to model specification and measurement error. We focus on the importance of typically unobserved but theoretically important variables (typically unobserved variables, TUVs), other non-standard covariates (NSCs), input reporting, and characterization of infant health. The TUVs represent wantedness, taste for risky behavior, and maternal health endowment. The NSCs include father characteristics. We estimate the effects of prenatal drug use, prenatal cigarette smoking, and first trimester prenatal care on birth weight, low birth weight, and a measure of abnormal infant health conditions. We compare estimates using self-reported inputs versus input measures that combine information from medical records and self-reports. We find that TUVs and NSCs are significantly associated with both inputs and outcomes, but that excluding them from infant health production functions does not appreciably affect the input estimates. However, using self-reported inputs leads to overestimated effects of inputs, particularly prenatal care, on outcomes, and using a direct measure of infant health does not always yield input estimates similar to those when using birth weight outcomes. The findings have implications for research, data collection, and public health policy. Copyright © 2008 John Wiley & Sons, Ltd. [source] Adaptive secure multicast in wireless networksINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 9 2009Yiliang Han Abstract Secure multicast is one of the majority services in the near future. The frameworks for IP multicast cannot be directly applied in wireless networks. To address the natural issues of wireless multicast and enhance the efficiency, an adaptive secure multicast framework based on a new primitive called multi-recipient generalized signcryption and a multi-recipient generalized signcryption scheme based on the gap Diffie,Hellman problem (MGSC-GDH) are proposed. The key technologies to construct a high-performance adaptive scheme including identification function, randomness reusing are investigated. The framework provides separate or joint encryption and signature functions according to users' identities and requirements transparently, and has the ability to aggregate multiple unicast besides the common multicast service. Therefore, overheads are reduced sharply for multiple functions which are provided with a single primitive. By the precise reduction, the gap-bridge between the security of a base scheme and the corresponding multi-recipient generalized signcryption scheme is built, which is a direct measure to quantify the security. Analysis shows that MGSC-GDH is a semantic secure multi-recipient generalized signcryption scheme and more efficient than other similar schemes in computational and communicational aspects. It is suitable for dynamic environment for rekeying is avoided when membership changes. Copyright © 2009 John Wiley & Sons, Ltd. [source] Predicting time-specific changes in demographic processes using remote-sensing dataJOURNAL OF APPLIED ECOLOGY, Issue 2 2006HENRIK B. RASMUSSEN Summary 1Models of wildlife population dynamics are crucial for sustainable utilization and management strategies. Fluctuating ecological conditions are often key factors influencing both carrying capacity, mortality and reproductive rates in ungulates. To be reliable, demographic models should preferably rely on easily obtainable variables that are directly linked to the ecological processes regulating a population. 2We compared the explanatory power of rainfall, a commonly used proxy for variability in ecological conditions, with normalized differential vegetation index (NDVI), a remote-sensing index value that is a more direct measure of vegetation productivity, to predict time-specific conception rates of an elephant population in northern Kenya. Season-specific conception rates were correlated with both quality measures. However, generalized linear logistic models compared using Akaike's information criteria showed that a model based on the NDVI measure outperformed models based on rainfall measures. 3A predictive model based on coarse demographic data and the maximum seasonal NDVI value was able to trace the large variation in observed season-specific conception rates (Range 0,0·4), with a low median deviation from observed values of 0·07. 4By combining the model of season-specific conception rates with the average seasonal distribution of conception dates, the monthly number of conceptions (range 0,22) could be predicted within ±3 with 80% confidence. 5Synthesis and applications. The strong predictive power of the normalized differential vegetation index on time-specific variation in a demographic variable is likely to be generally applicable to resource-limited ungulate species occurring in ecologically variable ecosystems, and could potentially be a powerful factor in demographic population modelling. [source] Is there a Difference?JOURNAL OF BUSINESS FINANCE & ACCOUNTING, Issue 1-2 2007The Performance Characteristics of SRI Equity Indices Abstract:, This study analyses whether stock indices that represent socially responsible investments (SRI) exhibit a different performance compared to conventional benchmark indices. In contrast to other studies, the analysis concentrates on SRI indices and not on investment funds. This has several advantages, since transaction costs of funds, the timing activities and the skill of the fund management do not have to be considered. A direct measure of the performance effects of SRI screens is therefore examined. The 29 SRI stock indices are analysed by single-equation models as well as by multi-equation systems that exploit the information in the cross-section. SRI stock indices do not exhibit a different level of risk-adjusted return than conventional benchmarks. But many SRI indices have a higher risk relative to the benchmarks. The findings are robust to the use of different benchmark indices and apply to all common types of SRI screening. [source] Human Capital and Stock Returns: Is the Value Premium an Approximation for Return on Human Capital?JOURNAL OF BUSINESS FINANCE & ACCOUNTING, Issue 3-4 2004Article first published online: 28 MAY 200, Bo Hansson This study, using a direct measure of the wage growth rate within firms, examines the value premium in relation to human capital. The results suggest that the dispersion in wage growth in value and growth stocks explains a large portion of the differences in stock returns. It appears that value stocks are less exposed to shocks in rents to human capital. Differences in labor force characteristics among value and growth stocks also proved to be an important factor in determining both the impact of future changes in labor income growth rate and firm value. The present findings are understood to mean that the ability of investors to forecast the dispersion in wage growth in firms is limited. [source] Mechanistic studies of branched-chain alkanols as skin permeation enhancersJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 3 2004Doungdaw Chantasart Abstract As part of a long-term effort to understand the structure/function relationship between chemical permeation enhancers and skin permeation enhancement, the present study examined the influence of hydrocarbon chain branching on the effectiveness of skin permeation enhancers of the type that possesses a polar group (e.g., the hydroxyl group) attached to a hydrocarbon chain(s). The effects of x -hexanol, x -heptanol, x -octanol, and x -nonanol (where x is the position of the hydroxyl group ranging from 1 up to 5) on the transport of a probe permeant, corticosterone, across hairless mouse skin (HMS) were investigated. Isoenhancement concentrations are defined as the aqueous concentrations for which different enhancers induce the same extent of permeant transport enhancement, E, across the lipoidal pathway of stratum corneum (SC). The isoenhancement concentrations of 2-alkanol, 3-alkanol, 4-alkanol, and 5-alkanol to induce E,=,10 were approximately 1.9-, 2.6-, 3.1-, and 3.9-fold higher, respectively, than those of the 1-alkanols of the same molecular formula. This suggested that the branched-chain alkanols have lower enhancer potency than the 1-alkanols of the same molecular formula; the potency decreases as the hydroxyl group moves from the end of the chain towards the center of the enhancer alkyl chain. To further investigate the mechanism(s) of action of the branched-chain alkanols as skin permeation enhancers, the equilibrium uptake of the enhancers into the hairless mouse skin stratum corneum (HMS SC) from aqueous enhancer solutions of E,=,10 was determined. The data from these experiments provided a direct measure of the "intrinsic" potency of the enhancer. In the same experiments, the equilibrium partitioning (distribution) of a surrogate permeant, estradiol (E2,), into the HMS SC was also determined and compared to the partitioning from PBS (no enhancer present). The uptake amounts (micromole/mg SC) for 1-alkanols into the intercellular lipids of the SC were found to be essentially the same at their isoenhancement concentrations. However, at their isoenhancement concentrations, the uptake amounts of the branched-chain alkanols into the intercellular lipids of HMS SC were higher than those of the 1-alkanols. These results support the view that: (1) the intrinsic potencies of the 1-alkanols are essentially the same and independent of their 1-alkyl chain length at their isoenhancement concentrations, (2) the intrinsic potencies of the branched-chain alkanols are lower than those of the normal alkanols, and (3) branching of the alkyl chain reduces the ability of the enhancer to effect lipid fluidization in the SC lipid lamellae at the target site(s). The enhancement effects of the branched-chain alkanols and the 1-alkanols at their isoenhancement concentrations upon E2, partitioning into the SC intercellular lipids were found to be approximately the same and in the range of five- to eight-fold enhancement. The constancy of this enhancement for E2, partitioning suggests that the mechanism of enhancement action for the branched-chain alkanols and the 1-alkanols are the same. Additionally, a good correlation of the intercellular lipid/PBS partition coefficients of both the branched-chain alkanols and the 1-alkanols with the n -octanol/PBS partition coefficients was found. This supports the view that the chemical microenvironment of the polar head group and the alkyl group of the studied enhancers at the site of skin permeation enhancer action in the SC lipid lamellae can be represented by water-saturated n -octanol for both the branched-chain alkanols and the 1-alkanols. © 2004 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 93:762,779, 2004 [source] An Inside View: Professional Judges' and Lay Judges' Support for Mixed TribunalsLAW & POLICY, Issue 2 2003Sanja Kutnjak Ivkovi This paper studies the level of specific and general support for mixed tribunals, a form of lay participation in the government. The analyses focus on the opinions provided by 229 Croatian lay judges and eighty professional judges , the insiders in mixed tribunals. The results indicate that the judge's lay or professional role in the criminal justice system and the type of court exhibit stronger influence on the general level of support than any of the variables measuring specific support. Nevertheless, the perceived frequency of lay judges' comments, the most direct measure of members' crucial activity during trials and deliberations among the specific variables included in the models, is significantly related to the respondents' general opinions about mixed tribunals. [source] Solid-state NMR studies of the molecular structure of TaxolMAGNETIC RESONANCE IN CHEMISTRY, Issue 6 2006Yu Ho Abstract Solid-state 13C{1H} cross-polarization/magic angle spinning spectroscopy (CP/MAS) has been utilized to extract the molecular structure information of Taxol, which is an anti-tumor therapeutic medicine extracted from the yew bark. The 13C signals have chemical shift values quite consistent with those measured in solution phase, and the overall chemical shift range is over 200 ppm. Notably, most of the 13C resonances of the taxane ring have two clearly resolved spectral components except the resonance peaks of C-15, C-16 and C-17, which are located at the central part of the taxane ring. On the basis of our NMR data, we propose that these doublets originate from two slightly different molecular conformations of the taxane ring and still the central part of the ring remains structurally similar. Furthermore, it is demonstrated that the 13C chemical shift difference deduced from the doublet splittings can serve as a direct measure of the structural difference between the two conformations, which could possibly correlate with the anti-tumor activity of Taxol. Copyright © 2006 John Wiley & Sons, Ltd. [source] Measurement of xylem sap amino acid concentrations in conjunction with whole tree transpiration estimates spring N remobilization by cherry (Prunus avium L.) treesPLANT CELL & ENVIRONMENT, Issue 12 2002G. GRASSI Abstract Prunus avium trees were grown in sand culture for one vegetative season with contrasting N supplies, in order to precondition their N storage capacities. During the spring of the second year a constant amount of 15N was supplied to all the trees, and the recovery of unlabelled N in the new biomass production was used as a direct measure of N remobilization. Destructive harvests were taken during spring to determine the pattern of N remobilization and uptake. Measurements of both xylem sap amino acid profiles and whole tree transpiration rates were taken, to determine whether specific amino acids are translocated as a consequence of N remobilization and if remobilization can be quantified by calculating the flux of these amino acids in the xylem. Whereas remobilization started immediately after bud burst, N derived from uptake by root appeared in the leaves only 3 weeks later. The tree internal N status affected both the amount of N remobilization and its dynamics. The concentration of xylem sap amino acids peaked shortly after bud burst, concurrently with the period of fastest remobilization. Few amino acids and amides (Gln, Asn and Asp) were responsible for most of N translocated through the xylem; however, their relative concentration varied over spring, demonstrating that the transport of remobilized N occurred mainly with Gln whereas transport of N taken up from roots occurred mainly with Asn. Coupling measurements of amino acid N in the xylem sap with transpiration values was well correlated with the recovery of unlabelled N in the new biomass production. These results are discussed in relation to the possibility of measuring the spring remobilization of N in field-grown trees by calculating the flux of N translocation in the xylem. [source] Runner balancing by a direct genetic optimization of shrinkagePOLYMER ENGINEERING & SCIENCE, Issue 10 2004Kevin Alam The proposed approach to the runner-balancing problem evaluates differences in shrinkage among the cavities and uses this direct measure of product quality to balance runner systems instead of the indirect methods traditionally used. The runner-balancing problem was characterized by multiple objectives, which consider both cost and product quality. The resulting multi-objective optimization problem was solved with a multi-objective genetic algorithm. Runner-balancing optimizations varied the diameters and lengths of the runners and the processing conditions. The results suggest that balanced runner systems, which exhibit large differences in cavity pressure profiles, can have lower product costs than systems characterized by similar fill times and cavity pressure profiles. The optimization of the secondary runner lengths and processing conditions also reduced costs significantly. Polym. Eng. Sci. 44:1949,1959, 2004. © 2004 Society of Plastics Engineers. [source] A preliminary investigation of the concurrent validity of reading comprehension rate: A direct, dynamic measure of reading comprehensionPSYCHOLOGY IN THE SCHOOLS, Issue 4 2007Christine E. Neddenriep Reading comprehension rate (RCR) is a direct measure of reading skills that may be useful in formatively evaluating students reading beyond the fourth-grade level. To investigate the concurrent validity of RCR, we correlated RCR, reading comprehension level (RCL), and words correct per minute (WC/M) with the Broad Reading Cluster Scores of the Woodcock-Johnson III Tests of Achievement (WJ-III ACH) across 88 students in 4th, 5th, and 10th grades. Results showed that aloud-RCR was significantly correlated with the WJ-III ACH scores for 4th-grade (r = .90; n = 22), 5th-grade (r = .87; n = 29), and 10th-grade (r = .65; n = 37) students. Regression analysis specified a one-predictor model for 4th-grade students (aloud-RCR), a two-predictor model for 5th-grade students (WC/M and aloud-RCR), and a one-predictor model for 10th-grade students (WC/M). Discussion focuses on directions for future research and applied issues related to RCR probe passage development. © 2007 Wiley Periodicals, Inc. Psychol Schs 44: 373,388, 2007. [source] Cancer-specific worry interference in women attending a breast and ovarian cancer risk evaluation program: impact on emotional distress and health functioningPSYCHO-ONCOLOGY, Issue 5 2001Peter C. Trask Intrusive thoughts about cancer, often identified as ,cancer-specific worries' or ,cancer-specific distress', have been postulated to be associated with dysfunction in women at increased risk of developing breast or ovarian cancer. The current study discusses the development and validation of a measure designed to assess women's perceptions of the interference such worries create in their daily functioning. Analyses revealed that approximately two-thirds of a high-risk breast cancer clinic sample perceived worries about breast cancer as interfering with their functioning across a variety of life domains. Multiple regression analyses indicated that worry interference scores predicted Profile of Mood States (POMS) Anxiety and Confusion, and Short Form-36 (SF-36) Role-Emotional and Mental Health scores after the effects of other variables such as frequency of worry about breast cancer, and having a family history of cancer had been considered. Women who perceived their worries as interfering with their functioning reported higher levels of anxiety and confusion, and diminished mental health and role functioning. The results add to the expanding area of anxiety/distress in at-risk populations by providing (1) a direct measure of the perceived interference associated with breast cancer-specific thoughts, (2) a validation of the measure via its associations with standard measures of emotional distress and health functioning, and (3) evidence of the measure's incremental predictive value in explaining distress and quality of life, after consideration of background variables, such as having a family history of cancer. Copyright © 2001 John Wiley & Sons, Ltd. [source] Vacancy-ordering effects in AlB2 -type ErGe2 ,x (0.4 < x, 0.5)ACTA CRYSTALLOGRAPHICA SECTION B, Issue 3 2008Jeppe Christensen In the Er,Ge system, the compostion range ErGe2 to Er2Ge3 has been investigated. Eight samples were produced by arc melting of the elements, and analyzed using X-ray powder diffraction. Nine crystal structures were found to be present in the samples. The structures are described as a homologous series and presented within the superspace formalism using the superspace group X2/m(,0,)0s, X representing the centring vector (½, ½, 0, ½). In this description the modulation vector q = (,a* + ,c*) is shown to be a direct measure of the Ge content as ErGe2,,,, (, falls in the range to ½). The large composition range is achieved by extended vacancy ordering in the planar 63 net of Ge with subsequent relaxation. [source] Efficiency measure, modelling and estimation in combined array designsAPPLIED STOCHASTIC MODELS IN BUSINESS AND INDUSTRY, Issue 4 2003Tak Mak Abstract In off-line quality control, the settings that minimize the variance of a quality characteristic are unknown and must be determined based on an estimated dual response model of mean and variance. The present paper proposes a direct measure of the efficiency of any given design-estimation procedure for variance minimization. This not only facilitates the comparison of different design-estimation procedures, but may also provide a guideline for choosing a better solution when the estimated dual response model suggests multiple solutions. Motivated by the analysis of an industrial experiment on spray painting, the present paper also applies a class of link functions to model process variances in off-line quality control. For model fitting, a parametric distribution is employed in updating the variance estimates used in an iteratively weighted least squares procedure for mean estimation. In analysing combined array experiments, Engel and Huele (Technometrics, 1996; 39:365) used log-link to model process variances and considered an iteratively weighted least squares leading to the pseudo-likelihood estimates of variances as discussed in Carroll and Ruppert (Transformation and Weighting in Regression, Chapman & Hall: New York). Their method is a special case of the approach considered in this paper. It is seen for the spray paint data that the log-link may not be satisfactory and the class of link functions considered here improves substantially the fit to process variances. This conclusion is reached with a suggested method of comparing ,empirical variances' with the ,theoretical variances' based on the assumed model. Copyright © 2003 John Wiley & Sons, Ltd. [source] Does equipartition hold in HFPs?ASTRONOMISCHE NACHRICHTEN, Issue 2-3 2009D. Dallacasa Abstract Equipartition of energy between relativistic particles and magnetic field is known to be consistent with observations in most of the large size (hundreds of kpc) radio galaxies. Here we discuss whether such a property holds in the smallest and youngest radio sources, the High Frequency Peakers (HFPs). A few sources have small components with a turnover frequency occurring at a few GHz and therefore a direct measure of the magnetic field intensity can be derived from the spectral peak assuming the spectral turnover is originated by synchrotron self-absorption. The field strengths computed in this way are generally in excellent agreement with the equipartition fields. However, a few exceptions have been found, in sources with an extra deficit of photons in the optically thick part of the spectrum as a consequence of free-free absorption (FFA) (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Reciprocal 13C-Labeling: A Method for Investigating the Catabolism of CosubstratesBIOTECHNOLOGY PROGRESS, Issue 2 2002Bjarke Christensen The principle of reciprocal labeling is to use a uniformly 13C-labeled substrate as the primary carbon source and a naturally labeled cosubstrate. Metabolites derived from a naturally labeled cosubstrate, in this case amino acids, can then be identified by their relatively lower content of 13C, and information on the degradation pathway can be deduced. The technique is based on GC,MS measurements of amino acid labeling patterns, making the technique well suited for investigating the relative importance of amino acid biosynthesis and amino acid uptake from the medium, as the 13C content of the amino acids incorporated into biomass is a direct measure of the amino acid biosyntheses. The technique is illustrated by the investigation of the degradation of phenoxyacetic acid, a medium component that is essential for production of penicillin V by Penicillium chrysogenum. Glucose was used as the uniformly labeled primary carbon source. [source] Multiple P2Y receptor subtypes in the apical membranes of polarized epithelial cellsBRITISH JOURNAL OF PHARMACOLOGY, Issue 8 2000H L McAlroy Apical ATP, ATP, UTP and UDP evoked transient increases in short circuit current (ISC, a direct measure of transepithelial ion transport) in confluent Caco-2 cells grown on permeable supports. These responses were mediated by a population of at least three pharmacologically distinct receptors. Experiments using cells grown on glass coverslips showed that ATP and UTP consistently increased intracellular free calcium ([Ca2+]i) whilst sensitivity to UDP was variable. Cross desensitization experiments suggested that the responses to UTP and ATP were mediated by a common receptor population. Messenger RNA transcripts corresponding to the P2Y2, P2Y4 and P2Y6 receptors genes were detected in cells grown on Transwell membranes by the reverse transcriptase,polymerase chain reaction. Identical results were obtained for cells grown on glass. Experiments in which ISC and [Ca2+]i were monitored simultaneously in cells on Transwell membranes, confirmed that apical ATP and UTP increased both parameters and showed that the UDP-evoked increase in ISC was accompanied by a [Ca2+]i -signal. Ionomycin consistently increased [Ca2+]i in such polarized cells but caused no discernible change in ISC. However, subsequent application of apical ATP or UTP evoked a small rise in ISC but no rise in [Ca2+]i. UDP evoked no such response. As well as evoking increases in [Ca2+]i, the ATP/UTP-sensitive receptors present in Caco-2 cells thus allow direct control over ion channels in the apical membrane. The UDP-sensitive receptors, however, appear to simply evoke a rise in [Ca2+]i. British Journal of Pharmacology (2000) 131, 1651,1658; doi:10.1038/sj.bjp.0703743 [source] Increased insulin sensitivity in young, growth hormone deficient childrenCLINICAL ENDOCRINOLOGY, Issue 1 2001Sandra Husbands OBJECTIVE Although growth hormone (GH) has well documented insulin antagonistic effects, GH deficient adults often demonstrate insulin resistance. In young GH deficient children, increased susceptibility to hypoglycaemia might indicate increased insulin sensitivity; however, this has not been documented. We therefore determined insulin sensitivity in GH deficient and GH sufficient children. DESIGN AND PATIENTS Prospective study of children undergoing insulin tolerance tests for clinical investigation of GH or cortisol secretion at a regional Paediatric Endocrine/Growth Clinic between October 1986 and December 1997. Ninety-one tests were performed in children with GH deficiency and 142 tests in children with normal GH response to insulin (peak GH , 20 IU/l). MEASUREMENTS The standard insulin tolerance test was modified to permit frequent measurements of glucose (0, 5, 10, 15, 20, 30, 45, 60 and 90 minutes). Rate of log glucose disappearance in the first 15 minutes was calculated as a direct measure of insulin sensitivity. RESULTS GH deficient children were more insulin sensitive than GH sufficient children (P = 0·004) and had lower glucose nadirs post-insulin (P = 0·005). Subgroup analysis revealed that these differences were greater in younger (< 12 years old) or pre/early pubertal children. In 14 prepubertal children, exogenous sex steroid priming resulted in lower insulin sensitivity (P < 0·05) compared to nonprimed tests. CONCLUSIONS Young GH deficient children were more insulin sensitive than children with normal GH secretion. This difference attenuated with age and puberty, possibly secondary to pubertal sex steroids; however, insulin resistance as reported in GH deficient adults, was not observed in adolescents. [source] Testing neural models of the development of infant visual attentionDEVELOPMENTAL PSYCHOBIOLOGY, Issue 3 2002John E. Richards Abstract Several models of the development of infant visual attention have used information about neural development. Most of these models have been based on nonhuman animal studies and have relied on indirect measures of neural development in human infants. This article discusses methods for studying a "neurodevelopmental" model of infant visual attention using indirect and direct measures of cortical activity. We concentrate on the effect of attention on eye movement control and show how animal-based models, indirect measurement in human infants, and direct measurement of brain activity inform this model. © 2002 Wiley Periodicals, Inc. Dev Psychobiol 40: 226,236, 2002. DOI 10.1002/dev.10029 [source] Exposure and effects assessment of resident mink (Mustela vison) exposed to polychlorinated dibenzofurans and other dioxin-like compounds in the Tittabawassee River basin, Midland, Michigan, USA,ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 10 2008Matthew J. Zwiernik Abstract Historically, sediments and floodplain soils of the Tittabawassee River (TR; MI, USA) have been contaminated with polychlorinated dibenzofurans (PCDFs), polychlorinated dibenzo- p -dioxins (PCDDs), and polychlorinatedbiphenyls (PCBs). Median concentrations of 2,3,7,8-tetrachlorodibenzo- p -dioxin equivalents (TEQs) based on 2006 World Health Organization tetrachloro-dibenzo- p -dioxin toxic equivalency factors (TEFs) in the diet of mink (Mustela vison) ranged from 6.8 × 10,1 ng TEQ/kg wet weight upstream of the primary source of PCDF to 3.1 × 101 ng TEQ/kg wet weight downstream. Estimates of toxicity reference values (TRVs) derived from laboratory studies with individual PCDDs/PCDFs and PCB congeners or mixtures of those congeners, as well as application of TEFs, were compared to site-specific measures of mink exposure. Hazard quotients based on exposures expressed as concentrations of TEQs in the 95th percentile of the mink diet or liver and the no-observable-adverse-effect TRVs were determined to be 1.7 and 8.6, respectively. The resident mink survey, however, including number of mink present, morphological measures, sex ratios, population age structure, and gross and histological tissue examination, indicated no observable adverse effects. This resulted for multiple reasons: First, the exposure estimate was conservative, and second, the predominantly PCDF congener mixture present in the TR appeared to be less potent than predicted from TEQs based on dose,response comparisons. Given this, there appears to be great uncertainty in comparing the measured concentrations of TEQs at this site to TRVs derived from different congeners or congener mixtures. Based on the lack of negative outcomes for any measurement endpoints examined, including jaw lesions, a sentinel indicator of possible adverse effects, and direct measures of effects on individual mink and their population, it was concluded that current concentrations of PCDDs/PCDFs were not causing adverse effects on resident mink of the TR. [source] Assessment of multiple implicit self-concept dimensions using the Extrinsic Affective Simon Task (EAST)EUROPEAN JOURNAL OF PERSONALITY, Issue 6 2004Sarah Teige This study explored the psychometric properties of the Extrinsic Affective Simon Task (EAST; De Houwer, 2003a) as adapted for the measurement of the implicit self-concept of personality. The EAST was adapted to allow the simultaneous assessment of the three traits shyness, anxiousness, and angriness. In order to test the EAST's psychometric properties, 100 participants completed a trait EAST, Implicit Association Tests (IATs), and direct self-ratings. The EAST showed low internal consistencies and correlated neither with the IATs nor with the direct measures. The main problem of the EAST, namely its low reliability, is discussed, and general conclusions regarding the indirect assessment of the personality self-concept by EASTs are derived. Copyright © 2004 John Wiley & Sons, Ltd. [source] Democrats with adjectives: Linking direct and indirect measures of democratic supportEUROPEAN JOURNAL OF POLITICAL RESEARCH, Issue 5 2007ANDREAS SCHEDLER Since people may entertain competing democratic ideas and ideals, however, the academic community ignores the extent to which standard questions capture citizen support for liberal democracy. To solve the validity problems associated with direct measures of democratic support, this article proposes linking them to more concrete, indirect measures of support for democratic principles and institutions. It employs the statistical technique of cluster analysis to establish this linkage. Cluster analysis permits grouping respondents in a way that is open to complex and inconsistent attitudinal profiles. It permits the identification of ,democrats with adjectives' who support democracy in the abstract, while rejecting core principles of liberal democracy. The article demonstrates the fruitfulness of this approach by drawing a map of ,illiberal democrats' in Mexico on the basis of the country's 2003 National Survey on Political Culture. [source] Evaluating interactions between soil drainage and seedling performance in a restoration of Pinus sylvestris woodland, ScotlandGLOBAL ECOLOGY, Issue 2 2001M. D. Crowell Abstract 1,This paper evaluates the role of soil drainage in tree seedling performance at a site being restored from Calluna vulgaris moorland to Pinus sylvestris woodland, in Glen Affric, Scotland. The investigation focuses on the relationships between height of planted seedlings, type of ground vegetation and drainage conditions. 2,Slope, aspect, and soil depth were assessed as potential surrogates for direct measures of soil drainage, all of which were derived from digital terrain data. 3,Six variables related to drainage were recorded at 58 seedling locations and used in a factor analysis to understand links between soil moisture conditions, topographic variables and soil depth characteristics. 4,Factor analysis generated two factors that accounted for 70.5% of the variance in the correlation matrix of these variables: Factor 1 correlated strongly with variables that controlled peat accumulation and Factor 2 correlated strongly with topographic controls upon drainage patterns. 5,These two factors explained a significant amount of the variance in height of the Pinus seedlings planted at these locations. Significant differences were found between the factor scores associated with different types of ground vegetation, as well as between the seedling heights observed at locations with different vegetation types. 6,Multiple regressions were developed that indicated that slope, aspect, and soil depth were significant as independent variables in models where soil moisture content and aerobic soil depth were the dependent variables. [source] Teamworking and organizational performance: A review of survey-based researchINTERNATIONAL JOURNAL OF MANAGEMENT REVIEWS, Issue 2 2008Anne Delarue This paper presents a review of recent survey-based research looking at the contribution of teamwork to organizational performance. In particular, it focuses on empirical studies in which both teamwork and performance are directly measured in a quantitative way. The paper begins by identifying four interrelated dimensions of teamwork effectiveness: attitudinal, behavioural, operational and financial. The first two represent transmission mechanisms by which organizational performance can be improved. The latter two provide direct measures of organizational outcomes. The review shows that teamworking has a positive impact on all four dimensions of performance. It also reveals that, when teamwork is combined with structural change, performance can be further enhanced. The paper concludes by highlighting some important research gaps that future studies could address. [source] Preparing a large data set for analysis: using the Minimum Data Set to study perineal dermatitisJOURNAL OF ADVANCED NURSING, Issue 4 2005Kay Savik MS Aim., The aim of this paper is to present a practical example of preparing a large set of Minimum Data Set records for analysis, operationalizing Minimum Data Set items that defined risk factors for perineal dermatitis, our outcome variable. Background., Research with nursing home elders remains a vital need as ,baby boomers' age. Conducting research in nursing homes is a daunting task. The Minimum Data Set is a standardized instrument used to assess many aspects of a nursing home resident's functional capability. United States Federal Regulations require a Minimum Data Set assessment of all nursing home residents. These large data would be a useful resource for research studies, but need to be extensively refined for use in most statistical analyses. Although fairly comprehensive, the Minimum Data Set does not provide direct measures of all clinical outcomes and variables of interest. Method., Perineal dermatitis is not directly measured in the Minimum Data Set. Additional information from prescribers' (physician and nurse) orders was used to identify cases of perineal dermatitis. The following steps were followed to produce Minimum Data Set records appropriate for analysis: (1) identification of a subset of Minimum Data Set records specific to the research, (2) identification of perineal dermatitis cases from the prescribers' orders, (3) merging of the perineal dermatitis cases with the Minimum Data Set data set, (4) identification of Minimum Data Set items used to operationalize the variables in our model of perineal dermatitis, (5) determination of the appropriate way to aggregate individual Minimum Data Set items into composite measures of the variables, (6) refinement of these composites using item analysis and (7) assessment of the distribution of the composite variables and need for transformations to use in statistical analysis. Results., Cases of perineal dermatitis were successfully identified and composites were created that operationalized a model of perineal dermatitis. Conclusion., Following these steps resulted in a data set where data analysis could be pursued with confidence. Incorporating other sources of data, such as prescribers' orders, extends the usefulness of the Minimum Data Set for research use. [source] | ||||||||||||||||||||||||||||