Modified Form (modified + form)

Distribution by Scientific Domains


Selected Abstracts


Age-dependent variations of cell response to oxidative stress: Proteomic approach to protein expression and phosphorylation

ELECTROPHORESIS, Issue 14 2005
Yuri Miura Dr.
Abstract We investigated the protein profiles of variously aged rat astrocytes in response to oxidative stress. After H2O2 -exposure of cells at 100,µM for 30,min, the relative intensity of ten protein spots changed on two-dimensional (2-D) gels compared with control gels after silver staining. Matrix-assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS) analysis after in-gel digestion revealed that six of these spots corresponded to three kinds of proteins, each of which was composed of a protein and its modified form with a different isoelectric point (pI). These three proteins were identified as peroxiredoxins (PRDXs) II and III, and calpactin I light chain (p11). H2O2 -exposure increased the intensity of the spot with lower pI and simultaneously decreased that of the spot with higher pI for both PRDXs II and III. In addition, the expression of annexin VII, S -adenosyl- L -homocysteine hydrolase, elongation factor II fragment (EF-II), and adenosine deaminase was increased by H2O2 -exposure in astrocytes from variously aged rats. Using the Pro-Q® Diamond staining, heat shock protein 60,kDa (Hsp 60) and ,-tubulin were observed to be phosphorylated upon H2O2 -exposure. While phosphorylation of ,-tubulin was correlated positively with age, the changes in abundance of ten protein spots as described above were independent of age. These results suggest that aging does not suppress the responses aimed at limiting injury and promoting repair brought about by severe oxidative stress, and might affect cell dynamics including the formation of microtubules. [source]


A case series evaluation of a modified version of interpersonal psychotherapy (IPT) for the treatment of bulimic eating disorders: A pilot study

EUROPEAN EATING DISORDERS REVIEW, Issue 4 2009
Jon Arcelus
Abstract Objective To determine the therapeutic outcome of a modified form of (IPT-BNm) amongst patients with Bulimia Nervosa (BN) and Eating Disorders Not Otherwise Specified (EDNOS). Method Following initial assessment, 59 patients with diagnoses of BN or EDNOS entered treatment in the form of 16 sessions of IPT-BNm. At initial assessment, patients completed measures of general psychopathology (SCL-90), Self esteem (RSE), eating psychopathology (EDE-Q), interpersonal functioning (Inventory of Interpersonal Functioning; IIP-32) and depression (BDI). At the middle and end of treatment, EDE-Q, IIP-32 and BDI measures were repeated. Results By the middle of therapy, patients had made significant improvements in terms of their eating disordered cognitions and behaviours (including reductions in EDE-Q scores, bingeing and self-induced vomiting), interpersonal functioning and levels of depression. Conclusions IPT-BNm is an effective treatment for patients with Bulimic Eating Disorders and appears to work quickly, as there were significant reductions in eating disorders symptoms within the first eight sessions of treatment. Copyright © 2009 John Wiley & Sons, Ltd and Eating Disorders Association. [source]


Assessment of rainfall-runoff models based upon wavelet analysis

HYDROLOGICAL PROCESSES, Issue 5 2007
Stuart N. Lane
Abstract A basic hypothesis is proposed: given that wavelet-based analysis has been used to interpret runoff time-series, it may be extended to evaluation of rainfall-runoff model results. Conventional objective functions make certain assumptions about the data series to which they are applied (e.g. uncorrelated error, homoscedasticity). The difficulty that objective functions have in distinguishing between different realizations of the same model, or different models of the same system, is that they may have contributed in part to the occurrence of model equifinality. Of particular concern is the fact that the error present in a rainfall-runoff model may be time dependent, requiring some form of time localization in both identification of error and derivation of global objective functions. We explore the use of a complex Gaussian (order 2) wavelet to describe: (1) a measured hydrograph; (2) the same hydrograph with different simulated errors introduced; and (3) model predictions of the same hydrograph based upon a modified form of TOPMODEL. The analysis of results was based upon: (a) differences in wavelet power (the wavelet power error) between the measured hydrograph and both the simulated error and modelled hydrographs; and (b) the wavelet phase. Power difference and wavelet phase were used to develop two objective functions, RMSE(power) and RMS(phase), which were shown to distinguish between simulated errors and model predictions with similar values of the commonly adopted Nash-Sutcliffe efficiency index. These objective functions suffer because they do not retain time, frequency or time-frequency localization. Consideration of wavelet power spectra and time- and frequency-integrated power spectra shows that the impacts of different types of simulated error can be seen through retention of some localization, especially in relation to when and the scale over which error was manifest. Theoretical objections to the use of wavelet analysis for this type of application are noted, especially in relation to the dependence of findings upon the wavelet chosen. However, it is argued that the benefits of localization and the qualitatively low sensitivity of wavelet power and phase to wavelet choice are sufficient to warrant further exploration of wavelet-based approaches to rainfall-runoff model evaluation. Copyright © 2006 John Wiley & Sons, Ltd. [source]


The canopy conductance of a boreal aspen forest, Prince Albert National Park, Canada

HYDROLOGICAL PROCESSES, Issue 9 2004
P. D. Blanken
Abstract Annual fluxes of canopy-level heat, water vapour and carbon dioxide were measured using eddy covariance both above the aspen overstory (Populus tremuloides Michx.) and hazelnut understory (Corylus cornuta Marsh.) of a boreal aspen forest (53·629 °N 106·200 °W). Partitioning of the fluxes between overstory and understory components allowed the calculation of canopy conductance to water vapour for both species. On a seasonal basis, the canopy conductance of the aspen accounted for 70% of the surface conductance, with the latter a strong function of the forest's leaf area index. On a half-hour basis, the canopy conductance of both species decreased non-linearly as the leaf-surface saturation deficits increased, and was best parameterized and showed similar sensitivities to a modified form of the Ball,Berry,Woodrow index, where relative humidity was replaced with the reciprocal of the saturation deficit. The negative feedback between the forest evaporation and the saturation deficit in the convective boundary layer varied from weak when the forest was at full leaf to strong when the forest was developing or loosing leaves. The coupling between the air at the leaf surface and the convective boundary layer also varied seasonally, with coupling decreasing with increasing leaf area. Compared with coniferous boreal forests, the seasonal changes in leaf area had a unique impact on vegetation,atmosphere interactions. Copyright © 2004 John Wiley & Sons, Ltd. [source]


State-space time integration with energy control and fourth-order accuracy for linear dynamic systems

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 5 2006
Steen Krenk
Abstract A fourth-order accurate time integration algorithm with exact energy conservation for linear structural dynamics is presented. It is derived by integrating the phase-space representation and evaluating the resulting displacement and velocity integrals via integration by parts, substituting the time derivatives from the original differential equations. The resulting algorithm has an exact energy equation, in which the change of energy is equal to the work of the external forces minus a quadratic form of the damping matrix. This implies unconditional stability of the algorithm, and the relative phase error is of fourth-order. An optional high-frequency algorithmic damping is constructed by optimal combination of three different damping matrices, each proportional to either the mass or the stiffness matrix. This leads to a modified form of the undamped algorithm with scalar weights on some of the matrices introducing damping of fourth-order in the frequency. Thus, the low-frequency response is virtually undamped, and the algorithm remains third-order accurate even when algorithmic damping is included. The accuracy of the algorithm is illustrated by an application to pulse propagation in an elastic medium, where the algorithmic damping is used to reduce dispersion due to the spatial discretization, leading to a smooth solution with a clearly defined wave front. Copyright © 2005 John Wiley & Sons, Ltd. [source]


Adaptive unknown input observer approach for aircraft actuator fault detection and isolation

INTERNATIONAL JOURNAL OF ADAPTIVE CONTROL AND SIGNAL PROCESSING, Issue 1 2007
Dan Wang
Abstract In this paper, an adaptive unknown input observer (UIO) approach is developed to detect and isolate aircraft actuator faults. In a multiple-model scheme, a bank of parallel observers are constructed, each of which is based on a model that describes the system in the presence of a particular actuator fault. The observers are constructed based on a modified form of the standard UIO to generate fault-dependant residual signals, such that when a model matches the system, the residual signal will be zero. Otherwise, the residual will be definitely non-zero and governed uniquely by the faulty signal. For locked actuators and loss of actuator effectiveness, in which the locked position and the reduced effectiveness are additional unknowns, we develop an adaptive scheme to estimate these unknown parameters. To the best of our knowledge, this is the first adaptive UIO presented. We prove that the proposed adaptive algorithms guarantee that both the residual signals and the estimation errors of the unknown parameters converge exponentially when a model matches the plant. By further designing a model-matching index, the fault can be isolated accurately. A condition for the approach is that for an nth order system, there must be n independent measurements available. This requirement limits the applicability of our proposed approach. The condition is certainly satisfied by all state-feedback control systems. However, for some other systems, extra efforts may be needed to increase the number of measurements. The method is applied to a linear model of the F-16 aircraft with controller. The results show that the approach is effective. Copyright © 2006 John Wiley & Sons, Ltd. [source]


Constructing a non-linear relationship between the incoming solar radiation and bright sunshine duration

INTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 12 2010
Khil-Ha Lee
Abstract This paper reports the application of a non-linear relationship between the incoming shortwave solar radiation and bright sunshine duration. The newly suggested equation is a modified form of the existing Angstrom equation. Measurements of solar radiation and sunshine radiation from 1997 to 2006 at 21 meteorological stations were used to calibrate and validate the suggested equation. The model parameters required to specify the nature of the relationship between solar radiation and sunshine duration were determined by automatically minimizing the difference between the modelled and measured solar radiation. At the 21 meteorological stations, the absolute error (AE) is in the range of ,0.126,0.158 MJm,2 day,1 for the original Angstrom equation, while it is in the range of ,0.089,0.154 MJm,2 day,1 for the modified equation. The root mean square error (RMSE) is also improved by 7,8% for the modified method. The results show that the newly suggested equation generally provides better performance than the existing Angstrom equation. Copyright © 2009 Royal Meteorological Society [source]


A systematic review of hand-assisted laparoscopic live donor nephrectomy

INTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 5 2004
P. Dasgupta
Summary We provide a systematic review of hand-assisted laparoscopic live donor nephrectomy (HALDN), a relatively new procedure. Medline search of HALDN between 1995 and 2002 was conducted. Published studies were scored by two independent assessors using a modified form of 11 generic questions. All questions required one of three responses: 0 , criterion not reported, 1 , criterion reported but inadequate, 2 , criterion reported and adequate. The studies were placed according to their scoRes in category A (score 20,22), category B (17,19) and category C (16 or less). Higher scores indicate better quality of studies. Where possible, statistical analysis of comparative data was performed. Most reports of HALDN are expert series, some comparative and a few prospective. There was good correlation between the assessors (r = 0.91), and of the seven published series on HALDN, two fell into category B and five into category C. At present, there is only one published randomised-controlled trial of HALDN vs. open donor nephrectomy; this is the only such trial in laparoscopic urology. HALDN allows kidneys to be harvested with short operating and warm ischaemia times and fewer ureteric complications. HALDN is a relatively new and effective technique, designed to make kidney donation more attractive and minimally invasive without affecting recipient outcomes. More prospective data of this technique is needed, and wide variation in reported outcome parameters need to be standardised to allow meaningful comparison. [source]


The construct validity of the client questionnaire of the Wisconsin Quality of Life Index , a cross-validation study

INTERNATIONAL JOURNAL OF METHODS IN PSYCHIATRIC RESEARCH, Issue 3 2003
Jean Caron
Abstract The Wisconsin Quality of Life Index (W-QLI, Becker, Diamond and Sainfort, 1993) consists of eight scales: satisfaction with life domains, occupational activities, symptoms, physical health, social relations/support, finances, psychological wellbeing, and activities of daily living. The W-QLI has been modified to fit the characteristics of the Canadian population, the universal Canadian health system, and community and social services in Canada and the modified form was named CaW-QLI (Diaz, Mercier, Hachey, Caron, and Boyer, 1999). This study will verify the empirical basis of these theoretical dimensions by applying a cross-validation procedure on two samples, most of whose subjects have a serious mental illness. Confirmatory factor analyses and exploratory factor analyses using the principal component extraction technique with varimax rotation were applied. With the exception of the occupational activities domain, the remaining scales were correctly identified by the factor analyses on each sample. The occupational activities scale should be developed by additional items for representing this scale, which is too brief, and two other items should be revised in order to improve the quality of the instrument. Copyright © 2003 Whurr Publishers Ltd. [source]


Explicitly correlated SCF study of anharmonic vibrations in (H2O)2

INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 4-5 2002
Donald D. Shillady
Abstract Modeling solvation in high-pressure liquid chromatography (HPLC) requires calculation of anharmonic vibrational frequencies of solvent clusters for a statistical partition function. An efficient computational method that includes electron correlation is highly desirable for large clusters. A modified version of the "soft Coulomb hole" method of Chakravorty and Clementi has recently been implemented in a Gaussian-lobe-orbital (GLO) program (PCLOBE) to include explicit electron,electron correlation in molecules. The soft Coulomb hole is based on a modified form of Coulomb's law: An algorithm has been developed to obtain the parameter "w" from a polynomial in the effective scaling of each primitive Gaussian orbital relative to the best single Gaussian of the H1s orbital. This method yields over 90% of the correlation energy for molecules of low symmetry for which the original formula of Chakravorty and Clementi does not apply. In this work, all the vibrations of the water dimer are treated anharmonically. A quartic perturbation of the harmonic vibrational modes is constrained to be equal to the exact Morse potential eigenvalue based on a three-point fit. This work evaluates the usefulness of fitting a Morse potential to a hydrogen bond vibrational mode and finds it to be slightly better than using MP2 vibrational analysis for this important dimer. A three-point estimate of the depth, De, of a Morse potential leads to a correction formula for anharmonicity in terms of the perturbed harmonic frequency: When scaled by 0.9141, the harmonic Morse method leads to essentially the same results as scaling the BPW91 local density method by 0.9827. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002 [source]


Effective thermal conductivity behavior of filled vulcanized perfluoromethyl vinyl ether rubber

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2008
Li Wang
Abstract The effective thermal conductivity behavior of vulcanized perfluoromethyl vinyl ether (PMVE) rubber filled with various inorganic fillers was investigated and analyzed with thermal conductivity models. Experimental results showed that there was no significant improvement in the thermal conductivity of PMVE rubber if the intrinsic thermal conductivity of the fillers was greater than 100 times that of the rubber matrix, and this agreed with the prediction of Maxwell's equation. The thermal conductivity of PMVE rubber filled with larger size silicon carbide (SiC) particles was greater than that of PMVE filled with smaller size SiC because of the lower interfacial thermal resistance, and there existed a transition filler loading at about 60 vol %. It was also found that flocculent graphite was the most effective thermally conductive filler among the fillers studied. A modified form of Agari's equation with a parameter independent on the units used was proposed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source]


Life satisfaction among older people (65+) with reduced self-care capacity: the relationship to social, health and financial aspects

JOURNAL OF CLINICAL NURSING, Issue 5 2006
Christel Borg RN
Aims and objectives., This study aimed at investigating life satisfaction and its relation to living conditions, overall health, self-care capacity, feeling lonely, physical activities and financial resources among people (65+) with reduced self-care capacity. Background., Knowledge about factors related to low life satisfaction among older people with reduced self-care capacity is sparse, although this is important in health care and nursing so that the care is adapted to their needs and perspective. Previous research has mainly focused on isolated aspects such as pain in relation to life satisfaction among older people in general and less among so those with reduced self-care capacity in general. Design and method., A subsample of 522 persons was selected from a randomly selected cross-sectional survey using a modified form of the Older Americans' Resources Schedule and Life Satisfaction Index Z. Results., The mean age in the total sample was 77·9; women (79·5) were significantly older than men (77·0). Low life satisfaction was found among women, as well as those living in special accommodations. Life Satisfaction Index Z was 15·3 (SD 5·6) in the total sample. Gender and living conditions did not explain life satisfaction whilst poor overall self-reported health and poor financial resources in relation to needs had the strongest explanatory value. Also of significant importance were loneliness, the degree of reduced self-care capacity and feeling worried. Conclusion., Life satisfaction in older people with reduced self-care capacity is determined by several factors, with social, physical, mental and financial aspects probably interacting with each other; especially feeling lonely, degree of self-care capacity, poor overall health, feeling worried and poor financial resources in relation to needs. These factors need to be considered in the care of these people to preserve or improve their life satisfaction. Relevance to clinical practice., Nursing interventions in terms of preventive home visits, rehabilitation, health education directed towards physical, psychological, social and economic aspects of importance may help to preserve or improve life satisfaction for those with reduced self-care capacity. [source]


Indicators Nurses Employ in Deciding to Test for Hyperbilirubinemia

JOURNAL OF OBSTETRIC, GYNECOLOGIC & NEONATAL NURSING, Issue 6 2001
Anita J. Gagnon RN
Objective: To identify the indicators nurses employ in deciding to test healthy full-term newborns for total serum bilirubin in the absence of a written protocol. Design: Secondary analysis of data available on 130 mother-newborn pairs and informal interviews of 30 postpartum unit nurses. Setting: Two university teaching hospitals. Participants: All tested newborns and a 33% random sample of remaining newborns from a control group data set created during a previous study and a convenience sample of postpartum nurses from all shifts. Measurement: Outcome data were obtained from a review of records. Background data were obtained from a review of records and questionnaires. Nurse data were obtained through a modified form of participant observation. Results: Ninety-one percent of newborns tested for bilirubin were tested unnecessarily. In logistic regression analyses, variables predictive of nurse-driven total serum bilirubin testing were presence of jaundice, odds ratio (OR) = 31.95 (95% confidence interval, 6.71, 152.03), and feeding frequency, OR = 0.28 (0.11, 0.72). Identifying both presence and location of jaundice simultaneously did not significantly predict testing, OR = 1.82 (0.66, 5.04). Fifty-three percent of nurses who were interviewed identified both the presence of jaundice and feeding as indicators to consider for testing. Conclusion: Newborns are overtested for bilirubin. Indicators used by nurses in deciding to test a healthy newborn for total serum bilirubin are the presence of jaundice and feeding frequency. Nurses who assess feeding frequency are less likely to order bilirubin testing. [source]


Carbon combustion synthesis of complex oxides: Process demonstration and features

AICHE JOURNAL, Issue 10 2005
K. S. Martirosyan
Abstract Carbon combustion synthesis of oxides (CCSO) is a novel process to rapidly produce high-purity, submicron, and porous powders of complex oxides. It is a modified form of self-propagating high temperature synthesis (SHS) that uses carbon as the fuel instead of a pure metal. The CO2 release increases the porosity and friability of the products. Like SHS, it is much faster (order of minutes) than the calcination processes (order of hours). CCSO has several advantages over SHS (the initial components are less expensive, porosity of the products is up to 70%). CCSO can produce complex oxides, such as LaGaO3, which cannot be produced by SHS. The feasibility and features of CCSO are illustrated by its use in producing barium titanate, lithium manganese, and lanthanum gallium oxides. The carbon concentration enabled control of the moving front temperature and average velocity and the particle size and surface area. © 2005 American Institute of Chemical Engineers AIChE J, 2005 [source]


Variant Creutzfeldt-Jakob disease: An unfolding epidemic of misfolded proteins

JOURNAL OF PAEDIATRICS AND CHILD HEALTH, Issue 6 2002
P Horby
Abstract: Variant Creutzfeldt-Jakob disease (vCJD) is an emerging infectious disease believed to be the human manifestation of bovine spongiform encephalopathy (BSE). Variant CJD belongs to a family of human and animal diseases called transmissible spongiform encephalopathies (TSE). The pathogenesis of TSE is not fully understood, but a modified form of a normal cellular protein plays a central role. Current measures to control vCJD aim to prevent transmission of the infectious agent from animals to humans through food or pharmaceutical products and to prevent transmission from person to person via medical interventions. The anticipated development of preclinical diagnostic tests and treatments for vCJD will create new control options and difficult choices. [source]


EFFECT OF HEN EGG PRODUCTION AND PROTEIN COMPOSITION ON TEXTURAL PROPERTIES OF EGG ALBUMEN GELS

JOURNAL OF TEXTURE STUDIES, Issue 2 2001
MARIANNE HAMMERSHØJ
The effect of hen age, strain and dietary amino acid intake on the egg albumen gel textural properties was studied in two experiments by textural profile analysis (TPA) and uniaxial compression (UC) tests. In experiment 1, eggs from 4 different hen flocks were heat processed industrially. Egg rejection due to poor albumen gelling was correlated to hen age (r = 0.502), albumen dry matter (r =,0.632), gel hardness of 1st compression (r =,0.765), and gel work of 1st compression (r =,0.740) in TPA. In experiment 2 two hen strains, representing two levels of egg production, were fed diets with supplementation of L-lysine, methionine or both amino acids compared to a control diet. The lysine intake ranged from 818,1272 mg/hen/day and methionine intake from 377,575 mg/hen/day among hen groups, but without significant effect on the albumen gel texture parameters. The hen strains differed significantly in egg production (P<0.001), physical (P<0.001), chemical (P<0.05) and gel textural parameters of egg albumen (P<0.01). Hen age was essential, and correlated to the industrial egg rejection (r = 0.729), albumen dry matter (r =,0.902) and gel stress at fracture (r =,0.884). Albumen gels with high fracture stress values were found to contain a modified form of ovofransferrin. [source]


Screening for High- and Moderate-Risk Drinking During Pregnancy: A Comparison of Several TWEAK-Based Screeners

ALCOHOLISM, Issue 9 2001
Deborah A. Dawson
Purpose: This study investigated the use of the TWEAK and nine alternative screeners for predicting high-risk and moderate-risk drinking during pregnancy. Method: The analysis was based on self-reports from 404 lifetime drinkers who presented for an initial visit at nine prenatal clinics in Washington, DC. Data were collected anonymously by having women directly enter their responses onto an audio, computer-assisted interview that was programmed onto a laptop computer. Pregnancy risk drinking status was based on both average daily volume of intake and frequency of drinking 3+ drinks in a day. Each of the alternative screeners was constructed by adding one additional risk indicator to the TWEAK, and three different scoring options were explored. Results: Using thresholds of 2 points for high-risk drinking and 1 point for moderate-risk drinking, the TWEAK demonstrated a sensitivity and specificity of 70.6% and 73.2% for high-risk drinking and a sensitivity and specificity of 65.6% and 63.7% for any (high- or moderate-) risk drinking during pregnancy. None of the alternative screeners resulted in significant improvement, but the addition of current smoking status showed enough promise to warrant further testing in larger samples. Conclusions: Despite some loss in sensitivity and specificity, the TWEAK, in its original or a modified form, can be extended to measures of high-risk drinking that incorporate infrequent heavy intake and can be used to test for moderate- as well as high-risk drinking. Because identification of moderate-risk drinkers substantially increases the pool of women targeted for intervention, cost implications must be considered in designing appropriate interventions. [source]


Impact craters in the northern hemisphere of Mars: Layered ejecta and central pit characteristics

METEORITICS & PLANETARY SCIENCE, Issue 10 2006
Nadine G. Barlow
Analysis of data in the revised catalog provides new details on the distribution and morphologic details of 6795 impact craters in the northern hemisphere of Mars. This report focuses on the ejecta morphologies and central pit characteristics of these craters. The results indicate that single-layer ejecta (SLE) morphology is most consistent with impact into an ice-rich target. Double-layer ejecta (DLE) and multiple-layer ejecta (MLE) craters also likely form in volatile-rich materials, but the interaction of the ejecta curtain and target-produced vapor with the thin Martian atmosphere may be responsible for the large runout distances of these ejecta. Pancake craters appear to be a modified form of double-layer craters where the thin outer layer has been destroyed or is unobservable at present resolutions. Pedestal craters are proposed to form in an icerich mantle deposited during high obliquity periods from which the ice has subsequently sublimated. Central pits likely form by the release of vapor produced by impact into ice-soil mixed targets. Therefore, results from the present study are consistent with target volatiles playing a dominant role in the formation of crater morphologies found in the Martian northern hemisphere. [source]


Effective Contracting of Social Services

NONPROFIT MANAGEMENT & LEADERSHIP, Issue 1 2001
Barbara Peat
The continued growth in the use of privatization for the delivery of social services increases the need for a systematic method to analyze the contracting process. Using a modified form of the basic systems model, the authors examine the impact of antecedents and situational factors and explore the use of traditional management steps in the contracting process. The authors focus on one state's experience with contracting to explore the implications of such a model. [source]


A new linear viscoelastic model for emulsions and suspensions

POLYMER ENGINEERING & SCIENCE, Issue 7 2008
Rajinder Pal
A new modified form of the Palierne model is proposed to describe the linear viscoelastic behavior of concentrated emulsions and suspensions. The proposed model takes into consideration the crowding effect and packing limit of particles. The model is verified using two sets of experimental data on the storage and loss moduli of emulsions and suspensions. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers [source]


Assessing the outdoor operating temperature of photovoltaic modules

PROGRESS IN PHOTOVOLTAICS: RESEARCH & APPLICATIONS, Issue 4 2008
David Faiman
Abstract By a careful study of data collected from seven varieties of photovoltaic (PV) module it is demonstrated that a simple modified form of the Hottel,Whillier,Bliss (HWB) equation, familiar from the analysis of flat-plate solar,thermal collectors, can be employed to predict module temperatures within an accuracy comparable to the cell-to-cell temperature differences typically encountered within a module. Furthermore, for modules within the range of construction parameters employed in this study, the actual values of the two modified HWB constants do not appear to depend upon module type. The implication of these results for the accuracy of outdoor module characterization is discussed. Copyright © 2008 John Wiley & Sons, Ltd. [source]


Weakly nonlocal irreversible thermodynamics

ANNALEN DER PHYSIK, Issue 3 2003
P. Ván
Abstract Weakly nonlocal thermodynamic theories are critically revisited. A relocalized, irreversible thermodynamic theory of nonlocal phenomena is given, based on a modified form of the entropy current and new kind of internal variables, the so called current multipliers. The treatment is restricted to deal with nonlocality connected to dynamic thermodynamic variables. Several classical equations are derived, including Guyer-Krumhansl, Ginzburg-Landau and Cahn-Hilliard type equations. [source]


A genetic algorithm for the identification of conformationally invariant regions in protein molecules

ACTA CRYSTALLOGRAPHICA SECTION D, Issue 2 2002
Thomas R. Schneider
Understanding macromolecular function often relies on the comparison of different structural models of a molecule. In such a comparative analysis, the identification of the part of the molecule that is conformationally invariant with respect to a set of conformers is a critical step, as the corresponding subset of atoms constitutes the reference for subsequent analysis for example by least-squares superposition. A method is presented that categorizes atoms in a molecule as either conformationally invariant or flexible by automatic analysis of an ensemble of conformers (e.g. crystal structures from different crystal forms or molecules related by non-crystallographic symmetry). Different levels of coordinate precision, both for different models and for individual atoms, are taken explicitly into account via a modified form of Cruickshank's DPI [Cruickshank (1999), Acta Cryst. D55, 583,601] and are propagated into error-scaled difference distance matrices [Schneider (2000), Acta Cryst. D56, 715,721]. All pairwise error-scaled difference distance matrices are then analysed simultaneously using a genetic algorithm. The algorithm has been tested on several well known examples and has been found to converge rapidly to reasonable results using a standard set of parameters. In addition to the description of the algorithm, a criterion is suggested for testing the identity of two three-dimensional models within experimental error without any explicit superposition. [source]


Detection and characterization of variant and modified structures of proteins in blood and tissues by mass spectrometry

MASS SPECTROMETRY REVIEWS, Issue 5 2006
Akira Shimizu
Abstract Some variant proteins cause diseases, and some diseases result in increases of proteins with abnormally modified structures. The detection, characterization, and estimation of the relative amounts of protein variants and abnormally modified proteins are important for clinical diagnosis and for elucidation of the mechanisms of the pathogenesis of diseases. Analysis of the covalent structures of proteins using matrix-assisted laser desorption time-of-flight mass spectrometry (MALDI-TOF-MS) and liquid chromatography-electrospray ionization MS (LC-ESI-MS), which had been developed by the early 1990s, have largely replaced analyses by conventional protein chemistry. Here, we review the detection and characterization of hemoglobin variants, HbA1c measurement, detection of carbohydrate-deficient transferrin, and identification of variants of transthyretin (TTR) and Cu/Zn-superoxide dismutase (SOD-1) using soft ionization MS. We also propose the diagnostic application of the signals of modified forms of TTR, that is, S-sulfonated TTR and S-homocysteinyl TTR. The relative peak height ratio of the abnormal/normal components gives valuable information about the instability of variants and enables the detection of unstable Hb subunits or thalassemia heterozygotes. We found unique modified structures of TTR that suggested changes in amyloid fibrils. © 2006 Wiley Periodicals, Inc. [source]


Investigation of cytolysin variants by peptide mapping: enhanced protein characterization using complementary ionization and mass spectrometric techniques

RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 22 2002
Stanley M. Stevens Jr.
Matrix-assisted laser desorption/ionization (MALDI) and electrospray ionization (ESI) have been used in conjunction with time-of-flight (TOF) and quadrupole ion trap (IT) mass spectrometry, respectively, to analyze various cytolysin proteins isolated from the sea anemone Stichodactyla helianthus and digested by the protease trypsin. By employing different ionization methods, the subsequent changes in ionization selectivity for the peptides in the digested protein samples resulted in ion abundance variation reflected in the mass spectra. Upon investigation of this variation generated by the two ionization processes, it has been shown in this study that enhanced protein coverage (e.g., >95% for cytolysin III) can be achieved. Additionally, capillary and microbore reversed-phase high-performance liquid chromatography (RP-HPLC) coupled with ESI mass spectrometry (MS) as well as flow injection analysis by nanoflow ESI-MS afforded the necessary limit of detection (LOD) for detailed structural information of the cytolysin proteins by tandem mass spectrometry (MS/MS) methods. It can be concluded that cytolysins II and III correspond to sticholysins I and II, that "cytolysin I" is a mixture of modified forms of cytolysins II and III, and that "cytolysin IV" is an incompletely processed precursor of cytolysin III. Copyright © 2002 John Wiley & Sons, Ltd. [source]