Sample records for variation method cvm
-
Gauge-free cluster variational method by maximal messages and moment matching.
Domínguez, Eduardo; Lage-Castellanos, Alejandro; Mulet, Roberto; Ricci-Tersenghi, Federico
2017-04-01
We present an implementation of the cluster variational method (CVM) as a message passing algorithm. The kind of message passing algorithm used for CVM, usually named generalized belief propagation (GBP), is a generalization of the belief propagation algorithm in the same way that CVM is a generalization of the Bethe approximation for estimating the partition function. However, the connection between fixed points of GBP and the extremal points of the CVM free energy is usually not a one-to-one correspondence because of the existence of a gauge transformation involving the GBP messages. Our contribution is twofold. First, we propose a way of defining messages (fields) in a generic CVM approximation, such that messages arrive on a given region from all its ancestors, and not only from its direct parents, as in the standard parent-to-child GBP. We call this approach maximal messages. Second, we focus on the case of binary variables, reinterpreting the messages as fields enforcing the consistency between the moments of the local (marginal) probability distributions. We provide a precise rule to enforce all consistencies, avoiding any redundancy, that would otherwise lead to a gauge transformation on the messages. This moment matching method is gauge free, i.e., it guarantees that the resulting GBP is not gauge invariant. We apply our maximal messages and moment matching GBP to obtain an analytical expression for the critical temperature of the Ising model in general dimensions at the level of plaquette CVM. The values obtained outperform Bethe estimates, and are comparable with loop corrected belief propagation equations. The method allows for a straightforward generalization to disordered systems.
-
Gauge-free cluster variational method by maximal messages and moment matching
NASA Astrophysics Data System (ADS)
Domínguez, Eduardo; Lage-Castellanos, Alejandro; Mulet, Roberto; Ricci-Tersenghi, Federico
2017-04-01
We present an implementation of the cluster variational method (CVM) as a message passing algorithm. The kind of message passing algorithm used for CVM, usually named generalized belief propagation (GBP), is a generalization of the belief propagation algorithm in the same way that CVM is a generalization of the Bethe approximation for estimating the partition function. However, the connection between fixed points of GBP and the extremal points of the CVM free energy is usually not a one-to-one correspondence because of the existence of a gauge transformation involving the GBP messages. Our contribution is twofold. First, we propose a way of defining messages (fields) in a generic CVM approximation, such that messages arrive on a given region from all its ancestors, and not only from its direct parents, as in the standard parent-to-child GBP. We call this approach maximal messages. Second, we focus on the case of binary variables, reinterpreting the messages as fields enforcing the consistency between the moments of the local (marginal) probability distributions. We provide a precise rule to enforce all consistencies, avoiding any redundancy, that would otherwise lead to a gauge transformation on the messages. This moment matching method is gauge free, i.e., it guarantees that the resulting GBP is not gauge invariant. We apply our maximal messages and moment matching GBP to obtain an analytical expression for the critical temperature of the Ising model in general dimensions at the level of plaquette CVM. The values obtained outperform Bethe estimates, and are comparable with loop corrected belief propagation equations. The method allows for a straightforward generalization to disordered systems.
-
The Cluster Variation Method: A Primer for Neuroscientists.
Maren, Alianna J
2016-09-30
Effective Brain-Computer Interfaces (BCIs) require that the time-varying activation patterns of 2-D neural ensembles be modelled. The cluster variation method (CVM) offers a means for the characterization of 2-D local pattern distributions. This paper provides neuroscientists and BCI researchers with a CVM tutorial that will help them to understand how the CVM statistical thermodynamics formulation can model 2-D pattern distributions expressing structural and functional dynamics in the brain. The premise is that local-in-time free energy minimization works alongside neural connectivity adaptation, supporting the development and stabilization of consistent stimulus-specific responsive activation patterns. The equilibrium distribution of local patterns, or configuration variables , is defined in terms of a single interaction enthalpy parameter ( h ) for the case of an equiprobable distribution of bistate (neural/neural ensemble) units. Thus, either one enthalpy parameter (or two, for the case of non-equiprobable distribution) yields equilibrium configuration variable values. Modeling 2-D neural activation distribution patterns with the representational layer of a computational engine, we can thus correlate variational free energy minimization with specific configuration variable distributions. The CVM triplet configuration variables also map well to the notion of a M = 3 functional motif. This paper addresses the special case of an equiprobable unit distribution, for which an analytic solution can be found.
-
The Cluster Variation Method: A Primer for Neuroscientists
Maren, Alianna J.
2016-01-01
Effective Brain–Computer Interfaces (BCIs) require that the time-varying activation patterns of 2-D neural ensembles be modelled. The cluster variation method (CVM) offers a means for the characterization of 2-D local pattern distributions. This paper provides neuroscientists and BCI researchers with a CVM tutorial that will help them to understand how the CVM statistical thermodynamics formulation can model 2-D pattern distributions expressing structural and functional dynamics in the brain. The premise is that local-in-time free energy minimization works alongside neural connectivity adaptation, supporting the development and stabilization of consistent stimulus-specific responsive activation patterns. The equilibrium distribution of local patterns, or configuration variables, is defined in terms of a single interaction enthalpy parameter (h) for the case of an equiprobable distribution of bistate (neural/neural ensemble) units. Thus, either one enthalpy parameter (or two, for the case of non-equiprobable distribution) yields equilibrium configuration variable values. Modeling 2-D neural activation distribution patterns with the representational layer of a computational engine, we can thus correlate variational free energy minimization with specific configuration variable distributions. The CVM triplet configuration variables also map well to the notion of a M = 3 functional motif. This paper addresses the special case of an equiprobable unit distribution, for which an analytic solution can be found. PMID:27706022
-
[Advances in congenital vertebral malformation caused by genomic copy number variation].
Liu, Zhenlei; Wu, Nan; Wu, Zhihong; Zuo, Yuzhi; Qiu, Guixing
2016-04-01
Congenital vertebral malformation (CVM) is a congenital vertebral structural deformity caused by abnormal somitogenesis during embryonic development, of which the reason lies in gene mutation or abnormal regulation of the genes that coordinate somitogenesis during embryonic period. ICVAS had proposed a new classification algorithm for CVM, which facilitated exploration for its genetic etiology. Genomic Copy Number Variation (CNV) is a kind of DNA mutation, which is important for human evolution, phenotype polymorphism and diseases. Series of advances have been made on genetic causes of CVM, especially on CVM caused by CNV. CNVs of chromosome 16p11.2, 10q24.31, 17p11.2, 20p11, 22q11.2 and a few other regions are associated with CVM, indicating that gene dosage may play important roles in the development of the spinal cord.
-
Health care contingent valuation studies: a review and classification of the literature.
Diener, A; O'Brien, B; Gafni, A
1998-06-01
The contingent valuation method (CVM) is a survey-based approach for eliciting consumer's monetary valuations for programme benefits for use in cost-benefit analysis (CBA). We used the conceptual framework of O'Brien and Gafni (1996) to classify and critically appraise health care CVM studies. Search of computerized health care and economic citation databases (e.g. MEDLINE, ECONLIT) and manual search for papers published between 1984 1996 reporting primary data valuing health programme benefits in monetary units by CVM using willingness-to-pay (WTP) or accept (WTA). We classified studies using both empirical (i.e. who was surveyed and how) and conceptual criteria (i.e. which measure of consumer utility was measured and why). 48 CVM studies were retrieved; the majority (42) undertook money valuation in the context of cost benefit analysis (CBA), with the remainder being pricing/demand studies. Among the 42 CBA studies, the consumer utility being measured (i.e. compensating (CV) vs. equivalent variation (EV) was explicitly stated in only three (7%) studies). WTP was measured in 95% of studies and WTA in 5%. By cross-tabulation, 42 (91%) studies were designed as WTP/CV, two (4%) were WTP/EV, two (4%) were WTA/CV and no studies used WTA/EV. Most studies were administered by mail (52%) with 38% being in-person interviews. Value elicitation techniques included open-ended questions (38%), payment cards (19%) discrete choice questions (26%) or bidding games (29%). Some form of construct validation tests, particularly associations between WTP and income, were done in 21 studies (50%). (i) The number of health care CVM studies is growing rapidly and the majority are done in the context of CBA; (ii) there is wide variation among health care CVM studies in terms of the types of questions being posed and the elicitation formats being used; (iii) classification and appraisal of the literature is difficult because reporting of methods and their relationship with the conceptual framework of CBA is poor; (iii) the applicability to health care of the CVM guidelines issued by the National Oceanic and Atmospheric Administration (NOAA) panel for environmental economics is unclear.
-
Quantum cluster variational method and message passing algorithms revisited
NASA Astrophysics Data System (ADS)
Domínguez, E.; Mulet, Roberto
2018-02-01
We present a general framework to study quantum disordered systems in the context of the Kikuchi's cluster variational method (CVM). The method relies in the solution of message passing-like equations for single instances or in the iterative solution of complex population dynamic algorithms for an average case scenario. We first show how a standard application of the Kikuchi's CVM can be easily translated to message passing equations for specific instances of the disordered system. We then present an "ad hoc" extension of these equations to a population dynamic algorithm representing an average case scenario. At the Bethe level, these equations are equivalent to the dynamic population equations that can be derived from a proper cavity ansatz. However, at the plaquette approximation, the interpretation is more subtle and we discuss it taking also into account previous results in classical disordered models. Moreover, we develop a formalism to properly deal with the average case scenario using a replica-symmetric ansatz within this CVM for quantum disordered systems. Finally, we present and discuss numerical solutions of the different approximations for the quantum transverse Ising model and the quantum random field Ising model in two-dimensional lattices.
-
Shono, Aiko; Kondo, Masahide; Ohmae, Hiroshi; Okubo, Ichiro
2014-06-01
In the health sectors of low- and middle-income countries, contingent valuation method (CVM) studies on willingness to pay (WTP) have been used to gather information on demand variation or financial perspectives alongside price setting, such as the introduction of user fees and valuation of quality improvements. However, WTP found in most CVM studies have only explored the preferences that consumers express through their WTP without exploring whether they are actually able to pay for it. Therefore, this study examines the issues pertaining to WTP estimation for health services using the conventional CVM. We conducted 202 household interviews in 2008, in which we asked respondents about three types of public health services in Indonesia and assessed WTP estimated by the conventional CVM as well as in the scenario of "resorting to debt" to recognize their budget constraints. We find that all the demand curves for both WTP scenarios show gaps. Furthermore, the gap for midwife services is negatively affected by household income and is larger for the poor. These results prove that CVM studies on WTP do not always reveal WTP in the latter scenario. Those findings suggest that WTP elicited by the conventional CVM is different to that from the maximum price that prevents respondents from resorting to debt as their WTP. In order to bridge this gap in the body of knowledge on this topic, studies should improve the scenarios that CVM analyses use to explore WTP. Furthermore, because valuing or pricing health services based on the results of CVM studies on WTP alone can exacerbate the inequity of access to these services, information provided by such studies requires careful interpretation when used for this purpose, especially for the poor and vulnerable sections of society. Copyright © 2014 Elsevier Ltd. All rights reserved.
-
Cervical vertebrae maturation method morphologic criteria: poor reproducibility.
Nestman, Trenton S; Marshall, Steven D; Qian, Fang; Holton, Nathan; Franciscus, Robert G; Southard, Thomas E
2011-08-01
The cervical vertebrae maturation (CVM) method has been advocated as a predictor of peak mandibular growth. A careful review of the literature showed potential methodologic errors that might influence the high reported reproducibility of the CVM method, and we recently established that the reproducibility of the CVM method was poor when these potential errors were eliminated. The purpose of this study was to further investigate the reproducibility of the individual vertebral patterns. In other words, the purpose was to determine which of the individual CVM vertebral patterns could be classified reliably and which could not. Ten practicing orthodontists, trained in the CVM method, evaluated the morphology of cervical vertebrae C2 through C4 from 30 cephalometric radiographs using questions based on the CVM method. The Fleiss kappa statistic was used to assess interobserver agreement when evaluating each cervical vertebrae morphology question for each subject. The Kendall coefficient of concordance was used to assess the level of interobserver agreement when determining a "derived CVM stage" for each subject. Interobserver agreement was high for assessment of the lower borders of C2, C3, and C4 that were either flat or curved in the CVM method, but interobserver agreement was low for assessment of the vertebral bodies of C3 and C4 when they were either trapezoidal, rectangular horizontal, square, or rectangular vertical; this led to the overall poor reproducibility of the CVM method. These findings were reflected in the Fleiss kappa statistic. Furthermore, nearly 30% of the time, individual morphologic criteria could not be combined to generate a final CVM stage because of incompatible responses to the 5 questions. Intraobserver agreement in this study was only 62%, on average, when the inconclusive stagings were excluded as disagreements. Intraobserver agreement was worse (44%) when the inconclusive stagings were included as disagreements. For the group of subjects that could be assigned a CVM stage, the level of interobserver agreement as measured by the Kendall coefficient of concordance was only 0.45, indicating moderate agreement. The weakness of the CVM method results, in part, from difficulty in classifying the vertebral bodies of C3 and C4 as trapezoidal, rectangular horizontal, square, or rectangular vertical. This led to the overall poor reproducibility of the CVM method and our inability to support its use as a strict clinical guideline for the timing of orthodontic treatment. Copyright © 2011 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.
-
Cervical vertebral maturation as a biologic indicator of skeletal maturity.
Santiago, Rodrigo César; de Miranda Costa, Luiz Felipe; Vitral, Robert Willer Farinazzo; Fraga, Marcelo Reis; Bolognese, Ana Maria; Maia, Lucianne Cople
2012-11-01
To identify and review the literature regarding the reliability of cervical vertebrae maturation (CVM) staging to predict the pubertal spurt. The selection criteria included cross-sectional and longitudinal descriptive studies in humans that evaluated qualitatively or quantitatively the accuracy and reproducibility of the CVM method on lateral cephalometric radiographs, as well as the correlation with a standard method established by hand-wrist radiographs. The searches retrieved 343 unique citations. Twenty-three studies met the inclusion criteria. Six articles had moderate to high scores, while 17 of 23 had low scores. Analysis also showed a moderate to high statistically significant correlation between CVM and hand-wrist maturation methods. There was a moderate to high reproducibility of the CVM method, and only one specific study investigated the accuracy of the CVM index in detecting peak pubertal growth. This systematic review has shown that the studies on CVM method for radiographic assessment of skeletal maturation stages suffer from serious methodological failures. Better-designed studies with adequate accuracy, reproducibility, and correlation analysis, including studies with appropriate sensitivity-specificity analysis, should be performed.
-
Szemraj, Agnieszka; Wojtaszek-Słomińska, Anna; Racka-Pilszak, Bogna
2018-05-01
Chronological age provides only general information on the development of a child/adolescent. However, the biological age of the patient is more significant. One of the methods is the determination of the bone age based on the development of the hand and wrist bones. In 1972 a method for assessing cervical vertebral maturation on the cephalometric radiographs was introduced (CVM method). As a result, additional patient radiation was eliminated. Currently, this type of radiograph is routinely applied in orthodontic treatment. The aim of the study was to assess the usefulness of the CVM method and to verify the assumption, according to which the CVM method modified by Baccetti et al. may replace the method for the assessment of skeletal maturation based on a hand-wrist X-ray, which is known as the hand-wrist maturation (HWM) method. The present study reviewed the literature between 2006 and 2016. In the first stage of selection 905 articles were obtained. Finally, 10 articles were enrolled for the review. All of the studies presented a high level of correlation between the examined methods. In eight articles the researchers admitted that the CVM classification could replace the HWM method, known as the "gold standard". In two studies , the researchers suggested considering the CVM method an additional method despite its compatibility and usefulness. The lowest correlation coefficient was 0.616 and the highest 0.937. The assessment of the skeletal age with the CVM is done on a cephalometric radiograph, routinely used in orthodontic practice, which makes it easy to apply. The determination of features of only C2, C3 and C4 vertebrae is possible even if the patient wears an X-ray protective thyroid collar. Therefore, the radiation dose is minimized. The CVM method shows a high level of correlation with the HWM method. Copyright © 2018 Elsevier B.V. All rights reserved.
-
Fudalej, Piotr; Bollen, Anne-Marie
2010-01-01
Our aim was to assess effectiveness of the cervical vertebral maturation (CVM) method to predict circumpubertal craniofacial growth in the postpeak period. The CVM stage was determined in 176 subjects (51 adolescent boys and 125 adolescent girls) on cephalograms taken at the end of treatment (T2; mean ages, 15.75 years [boys] and 15.23 years [girls]) in subjects from the postretention database at the University of Washington in Seattle. Craniofacial growth was evaluated from the following measurements on cephalograms at T2 and end of follow-up (T3) (mean ages, 29.01 years [men] and 28.08 years [women]): condylion to gnathion, condylion to gonion, gonion to gnathion, sella to gnathion, nasion to menton, anterior nasal spine to menton, and sella to gonion. The change of each variable from T2 to T3 was assessed with paired t tests. Parametric (t tests or analysis of variance [ANOVA]) or nonparametric (Mann-Whitney or Kruskal-Wallis) tests were used to detect intergroup differences. One hundred eight subjects (35 boys, 73 girls) demonstrated CVM stage 3, 56 (16 boys, 40 girls) were in CVM stage 4, and 12 (all girls) were in CVM stage 5 at T2. Intrasex comparisons showed that boys in CVM stages 3 and 4 could be differentiated regarding changes of all variables. In the girls, only those in CVM stages 3 and 4 could be differentiated based on the amount of changes of 2 measurements: condylion to gonion and sella to gonion. Intersex comparisons showed that boys in CVM stage 3 had significantly more changes than girls (P <0.01). Boys in CVM stage 4 showed significant differences compared with girls in CVM stage 4 for only 2 variables (sella to gonion and condylion to gonion; P <0.001 and P = 0.012, respectively). The CVM method was modestly effective in determining the amount of postpeak circumpubertal craniofacial growth. Copyright 2010 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.
-
Giri, Jamal; Shrestha, Basanta Kumar; Yadav, Rajiv; Ghimire, Tika Ram
2016-01-01
Assessment of growth status of a patient is a key component in orthodontic diagnosis and treatment planning for growing patients with skeletal discrepancy. Skeletal maturation based on hand-wrist radiograph and cervical vertebral maturation (CVM) are commonly used methods of growth assessment. Studies have shown that stages of dental calcification can also be used to assess skeletal maturation status of an individual, whereas other studies have suggested that the relationship between dental calcification and skeletal maturation should be interpreted with caution owing to racial variation. To evaluate the relationship between permanent mandibular second molar calcification stages and skeletal maturity assessed by CVM among a group of Nepalese orthodontic patients. One hundred and sixty-eight digital radiographs (84 orthopantomograms and 84 lateral cephalograms) were obtained from the records of 84 patients who sought orthodontic treatment in Orthodontic and Dentofacial Orthopaedic Unit, Department of Dentistry, Institute of Medicine, Kathmandu. Two parameters were used in this study, namely, CVM stages from lateral cephalogram and Demirjian index (DI) stages from orthopantomogram. The evaluation of digital radiographs was carried out on a computer screen with a resolution of 1,280×800 pixels. The association between DI stages of permanent mandibular second molar and CVM stages was assessed. A statistically significant association was found between DI and CVM stages for both male and female subjects with Pearson's contingency coefficient value of 0.751 and 0.766 for male and female subjects, respectively. Skeletal maturation can be reliably assessed with dental calcification stages of permanent mandibular second molar for Nepalese orthodontic patients.
-
Use of cervical vertebral maturation to determine skeletal age.
Wong, Ricky W K; Alkhal, Hessa A; Rabie, A Bakr M
2009-10-01
The purpose of this study was to evaluate the validity of the cervical vertebral maturation (CVM) method as an indicator of skeletal age in the circumpubertal period by correlating it to the hand-wrist method (HWM). Hand-wrist and lateral cephalometric radiographs of 400 Chinese subjects were randomly selected. Their ages were 10 to 15 years for girls and 12 to 17 years for boys, so they were within the circumpubertal period. Skeletal ages were assessed according to the CVM method and the HWM. The CVM was significantly correlated with HWM skeletal age (Spearman r = 0.9521 [boys] and 0.9408 [girls]). All patients in cervical vertebral stage 3 of the CVM corresponded to stages MP3-FG or MP3-G (around the peak of the growth spurt) in the HWM. The CVM is a valid indicator of skeletal growth during the circumpubertal period, providing information for timing of growth modification.
-
Perinetti, Giuseppe; Bianchet, Alberto; Franchi, Lorenzo; Contardo, Luca
2017-05-01
To date, little information is available regarding individual cervical vertebral maturation (CVM) morphologic changes. Moreover, contrasting results regarding the repeatability of the CVM method call for the use of objective and transparent reporting procedures. In this study, we used a rigorous morphometric objective CVM code staging system, called the "CVM code" that was applied to a 6-year longitudinal circumpubertal analysis of individual CVM morphologic changes to find cases outside the reported norms and analyze individual maturation processes. From the files of the Oregon Growth Study, 32 subjects (17 boys, 15 girls) with 6 annual lateral cephalograms taken from 10 to 16 years of age were included, for a total of 221 recordings. A customized cephalometric analysis was used, and each recording was converted into a CVM code according to the concavities of cervical vertebrae (C) C2 through C4 and the shapes of C3 and C4. The retrieved CVM codes, either falling within the reported norms (regular cases) or not (exception cases), were also converted into the CVM stages. Overall, 31 exception cases (14%) were seen. with most of them accounting for pubertal CVM stage 4. The overall durations of the CVM stages 2 to 4 were about 1 year, even though only 4 subjects had regular annual durations of CVM stages 2 to 5. Whereas the overall CVM changes are consistent with previous reports, intersubject variability must be considered when dealing with individual treatment timing. Future research on CVM may take advantage of the CVM code system. Copyright © 2017 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.
-
Nunn, Kenetta L.; Wang, Ying-Ying; Harit, Dimple; Humphrys, Michael S.; Ma, Bing; Cone, Richard; Ravel, Jacques
2015-01-01
ABSTRACT Cervicovaginal mucus (CVM) can provide a barrier that precludes HIV and other sexually transmitted virions from reaching target cells in the vaginal epithelium, thereby preventing or reducing infections. However, the barrier properties of CVM differ from woman to woman, and the causes of these variations are not yet well understood. Using high-resolution particle tracking of fluorescent HIV-1 pseudoviruses, we found that neither pH nor Nugent scores nor total lactic acid levels correlated significantly with virus trapping in unmodified CVM from diverse donors. Surprisingly, HIV-1 was generally trapped in CVM with relatively high concentrations of d-lactic acid and a Lactobacillus crispatus-dominant microbiota. In contrast, a substantial fraction of HIV-1 virions diffused rapidly through CVM with low concentrations of d-lactic acid that had a Lactobacillus iners-dominant microbiota or significant amounts of Gardnerella vaginalis, a bacterium associated with bacterial vaginosis. Our results demonstrate that the vaginal microbiota, including specific species of Lactobacillus, can alter the diffusional barrier properties of CVM against HIV and likely other sexually transmitted viruses and that these microbiota-associated changes may account in part for the elevated risks of HIV acquisition linked to bacterial vaginosis or intermediate vaginal microbiota. PMID:26443453
-
First-principles study of intermetallic phase stability in the ternary Ti-Al-Nb alloy system
DOE Office of Scientific and Technical Information (OSTI.GOV)
Asta, M.; Ormeci, A.; Wills, J.M.
The stability of bcc-based phases in the Ti-Al-Nb alloy system has been studied from first-principles using a combination of ab-initio total energy and cluster variation method (CVM) calculations. Total energies have been computed for 18 binary and ternary bcc superstructures in order to determine low temperature ordering tendencies. From the results of these calculations a set of effective cluster interaction parameters have been derived. These interaction parameters are required input for CVM computations of alloy thermodynamic properties. The CVM has been used to study the effect of composition on finite-temperature ordering tendencies and site preferences for bcc-based phases. Strong orderingmore » tendencies are observed for binary Nb-Al and Ti-Al bcc phases as well as for ternary alloys with compositions near Ti{sub 2}AlNb. For selected superstructures we have also analyzed structural stabilities with respect to tetragonal distortions which transform the bcc into an fcc lattice. Instabilities with respect to such distortions are found to exist for binary but not ternary bcc compounds.« less
-
A new EEG measure using the 1D cluster variation method
NASA Astrophysics Data System (ADS)
Maren, Alianna J.; Szu, Harold H.
2015-05-01
A new information measure, drawing on the 1-D Cluster Variation Method (CVM), describes local pattern distributions (nearest-neighbor and next-nearest neighbor) in a binary 1-D vector in terms of a single interaction enthalpy parameter h for the specific case where the fractions of elements in each of two states are the same (x1=x2=0.5). An example application of this method would be for EEG interpretation in Brain-Computer Interfaces (BCIs), especially in the frontier of invariant biometrics based on distinctive and invariant individual responses to stimuli containing an image of a person with whom there is a strong affiliative response (e.g., to a person's grandmother). This measure is obtained by mapping EEG observed configuration variables (z1, z2, z3 for next-nearest neighbor triplets) to h using the analytic function giving h in terms of these variables at equilibrium. This mapping results in a small phase space region of resulting h values, which characterizes local pattern distributions in the source data. The 1-D vector with equal fractions of units in each of the two states can be obtained using the method for transforming natural images into a binarized equi-probability ensemble (Saremi & Sejnowski, 2014; Stephens et al., 2013). An intrinsically 2-D data configuration can be mapped to 1-D using the 1-D Peano-Hilbert space-filling curve, which has demonstrated a 20 dB lower baseline using the method compared with other approaches (cf. SPIE ICA etc. by Hsu & Szu, 2014). This CVM-based method has multiple potential applications; one near-term one is optimizing classification of the EEG signals from a COTS 1-D BCI baseball hat. This can result in a convenient 3-D lab-tethered EEG, configured in a 1-D CVM equiprobable binary vector, and potentially useful for Smartphone wireless display. Longer-range applications include interpreting neural assembly activations via high-density implanted soft, cellular-scale electrodes.
-
Perinetti, Giuseppe; Primozic, Jasmina; Sharma, Bhavna; Cioffi, Iacopo; Contardo, Luca
2018-03-28
The capability of the cervical vertebral maturation (CVM) method in the identification of the mandibular growth peak on an individual basis remains undetermined. The diagnostic reliability of the six-stage CVM method in the identification of the mandibular growth peak was thus investigated. From the files of the Oregon and Burlington Growth Studies (data obtained between early 1950s and middle 1970s), 50 subjects (26 females, 24 males) with at least seven annual lateral cephalograms taken from 9 to 16 years were identified. Cervical vertebral maturation was assessed according to the CVM code staging system, and mandibular growth was defined as annual increments in Co-Gn distance. A diagnostic reliability analysis was carried out to establish the capability of the circumpubertal CVM stages 2, 3, and 4 in the identification of the imminent mandibular growth peak. Variable durations of each of the CVM stages 2, 3, and 4 were seen. The overall diagnostic accuracy values for the CVM stages 2, 3, and 4 were 0.70, 0.76, and 0.77, respectively. These low values appeared to be due to false positive cases. Secular trends in conjunction with the use of a discrete staging system. In most of the Burlington Growth Study sample, the lateral head film at age 15 was missing. None of the CVM stages 2, 3, and 4 reached a satisfactorily diagnostic reliability in the identification of imminent mandibular growth peak.
-
Fan, Zi Juan; Ao, Chang Lin; Mao, Bi Qi; Chen, Hong Guang; Wang, Xu Dong
2017-02-01
Stated preference method is usually used to evaluate the non-market value of environmental goods which includes contingent valuation method (CVM) and choice experiments (CE). In this paper, stated preference method was adopted to evaluate the non-market value of Sanjiang Plain wetland. A willingness to pay (WTP) evaluation model of stated preference method was constructed based on the random utility theory. The average WTP of CVM and CE was obtained, respectively. The average WTP elicited by CE was 379 yuan per year, and the marginal WTPs of different selection properties including water conservation, wetland area, natural landscape and biodiversity were114.00, 72.55, 59.55 and 37.09 yuan per year, respectively. Meanwhile, the average WTP elicited by CVM was 134 yuan per year. The influence of factors on WTP was analyzed and reasons for protest responses were discussed. Results showed that the respondents' WTP elicited by CE was signi-ficantly higher than that by CVM, and respondents' socio-economic attitudes such as level of education and personal annual income had a significant positive impact on respondents' WTP. There were no significant difference in the reasons of protest responses between CVM and CE. Besides, respondents' multiple attributes and multiple levels analysis could be carried out by CE and the WTP of wetland's selection attributes could be calculated. Therefore, CE had the better ability of revealing respondents' preference information than CVM and its assessment results were more close to the actual value.
-
Reliability of the cervical vertebrae maturation (CVM) method.
Predko-Engel, A; Kaminek, M; Langova, K; Kowalski, P; Fudalej, P S
2015-01-01
To assess the reliability of the cervical vertebrae maturation method (CVM). Skeletal maturity estimation can influence the manner and time of orthodontic treatment. The CVM method evaluates skeletal growth on the basis of the changes in the morphology of cervical vertebrae C2, C3, C4 during growth. These vertebrae are visible on a lateral cephalogram, so the method does not require an additional radiograph. In this website based study, 10 orthodontists with a long clinical practice (3 routinely using the method - "Routine user - RU" and 7 with less experience in the CVM method - "Non-Routine user - nonRU") rated twice cervical vertebrae maturation with the CVM method on 50 cropped scans of lateral cephalograms of children in circumpubertal age (for boys: 11.5 to 15.5 years; for girls: 10 to 14 years). Kappa statistics (with lower limits of 95% confidence intervals (CI)) and proportion of complete agreement on staging was used to evaluate intra- and inter-assessor agreement. The mean weighted kappa for intra-assessor agreement was 0.44 (range: 0.30-0.64; range of lower limits of 95% CI: 0.12-0.48) and for inter-assessor agreement was 0.28 (range: -0.01-0.58; range of lower limits of 95% CI: -0.14-0.42). The mean proportion of identical scores assigned by the same assessor was 55.2 %(range: 44-74 %) and for different pairs of assessors was 42 % (range: 16-68 %). The reliability of the CVM method is questionable and if orthodontic treatment should be initiated relative to the maximum growth, the use of additional biologic indicators should be considered (Tab. 4, Fig. 1, Ref. 24).
-
Alkhal, Hessa Abdulla; Wong, Ricky W K; Rabie, A Bakr M
2008-07-01
To investigate the correlation between chronological age, cervical vertebral maturation (CVM), and Fishman's hand-wrist skeletal maturity indicators in southern Chinese. Four hundred contemporary hand-wrist and lateral cephalometric radiographs of southern Chinese subjects were randomly selected and analyzed. The female subjects were between 10 and 15 years of age, and the male subjects were between 12 and 17 years of age; all subjects were within the circumpubertal period. The CVM was assessed using the method developed by Baccetti and coworkers, but the hand-wrist maturation was assessed using the method developed by Fishman. These two methods and the chronological age were correlated using the Spearman rank correlation analysis. The CVM was significantly correlated with the hand-wrist skeletal age (Spearman r male = 0.9206, female = 0.9363). All patients in the cervical maturation stage (CS3) of CVM were discovered to be in the skeletal maturational indicator (SMI2 or SMI3) stages of hand-wrist maturation (HWM), which was around the peak of the growth spurt. Low correlations were found between the CVM and chronological age (male r = 0.7577; female r = 0.7877) and between the HWM and chronological age (male r = 0.7492; female r = 0.7758). CVM is a valid indicator of skeletal growth during the circumpubertal and has a high correlation with the HWM for the southern Chinese population. However, the low correlations found between the chronological age and both CVM and HWM showed that the chronological age was not suitable to measure skeletal maturity.
-
Estimating the economic impact of climate change on cardiovascular diseases--evidence from Taiwan.
Liao, Shu-Yi; Tseng, Wei-Chun; Chen, Pin-Yu; Chen, Chi-Chung; Wu, Wei-Min
2010-12-01
The main purpose of this study was to investigate how climate change affects blood vessel-related heart disease and hypertension and to estimate the associated economic damage. In this paper, both the panel data model and the contingent valuation method (CVM) approaches are applied. The empirical results indicate that the number of death from cardiovascular diseases would be increased by 0.226% as the variation in temperature increases by 1%. More importantly, the number of death from cardiovascular diseases would be increased by 1.2% to 4.1% under alternative IPCC climate change scenarios. The results from the CVM approach show that each person would be willing to pay US$51 to US$97 per year in order to avoid the increase in the mortality rate of cardiovascular diseases caused by climate change.
-
Estimating the Economic Impact of Climate Change on Cardiovascular Diseases—Evidence from Taiwan
Liao, Shu-Yi; Tseng, Wei-Chun; Chen, Pin-Yu; Chen, Chi-Chung; Wu, Wei-Min
2010-01-01
The main purpose of this study was to investigate how climate change affects blood vessel-related heart disease and hypertension and to estimate the associated economic damage. In this paper, both the panel data model and the contingent valuation method (CVM) approaches are applied. The empirical results indicate that the number of death from cardiovascular diseases would be increased by 0.226% as the variation in temperature increases by 1%. More importantly, the number of death from cardiovascular diseases would be increased by 1.2% to 4.1% under alternative IPCC climate change scenarios. The results from the CVM approach show that each person would be willing to pay US$51 to US$97 per year in order to avoid the increase in the mortality rate of cardiovascular diseases caused by climate change. PMID:21318006
-
Agreement of Tracing and Direct Viewing Techniques for Cervical Vertebral Maturation Assessment.
Wiwatworakul, Opas; Manosudprasit, Montian; Pisek, Poonsak; Chatrchaiwiwatana, Supaporn; Wangsrimongkol, Tasanee
2015-08-01
This study aimed to evaluate agreement among three methods for cervical vertebral maturation (CVM) assessment, comprising direct viewing, tracing only, and tracing with digitized points. Two examiners received training and tests of reliability with each CVM method before evaluation of agreement among methods. The subjects were 96 female-cleft lateral cephalometric radiographs (films of eight subjects for each age ranged from seven to 18 years). The examiners interpreted CVM stages of the subjects with four-week interval between uses of each method. The range of weighted kappa values for paired comparisons among the three methods were: 0.96-0.98 for direct viewing and tracing only comparison; 0.93-0.94 for direct viewing and tracing with digitized points comparison; and 0.96-0.97 for tracing only and tracing with digitized points comparison. The intraclass correlation coefficient (ICC) value among the three methods was 0.95. These results indicated very good agreement among methods. Use of direct viewing is suitable for CVM assessment without spending more time for tracing. However, the three methods might be used interchangeably.
-
Reliability of cervical vertebral maturation staging.
Rainey, Billie-Jean; Burnside, Girvan; Harrison, Jayne E
2016-07-01
Growth and its prediction are important for the success of many orthodontic treatments. The aim of this study was to determine the reliability of the cervical vertebral maturation (CVM) method for the assessment of mandibular growth. A group of 20 orthodontic clinicians, inexperienced in CVM staging, was trained to use the improved version of the CVM method for the assessment of mandibular growth with a teaching program. They independently assessed 72 consecutive lateral cephalograms, taken at Liverpool University Dental Hospital, on 2 occasions. The cephalograms were presented in 2 different random orders and interspersed with 11 additional images for standardization. The intraobserver and interobserver agreement values were evaluated using the weighted kappa statistic. The intraobserver and interobserver agreement values were substantial (weighted kappa, 0.6-0.8). The overall intraobserver agreement was 0.70 (SE, 0.01), with average agreement of 89%. The interobserver agreement values were 0.68 (SE, 0.03) for phase 1 and 0.66 (SE, 0.03) for phase 2, with average interobserver agreement of 88%. The intraobserver and interobserver agreement values of classifying the vertebral stages with the CVM method were substantial. These findings demonstrate that this method of CVM classification is reproducible and reliable. Copyright © 2016 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.
-
Fudalej, Piotr; Rothe, Laura E; Bollen, Anne-Marie
2008-08-01
Our aim was to test the hypothesis that relapse of incisor alignment is associated with skeletal maturity at the end of treatment, as assessed with the cervical vertebral maturation (CVM) method. This was a case-control study with information from the postretention database at the University of Washington. Mandibular incisor irregularity (II) at least 10 years out of retention (T3) was used to define the subjects (II >6 mm, relapse group) and the controls (II <3.5 mm, stable group). The following model measurements were made: II at pretreatment (T1), II at posttreatment (T2), and intercanine width at T1 and T2. On cephalograms taken T2, the CVM status was determined. Logistic regression analyses were used to determine the association between relapse and CVM status after treatment. The models were adjusted for potentially confounding variables (II at pretreatment and posttreatment, intercanine width change during treatment, sex, age at T2, and treatment alternatives). No association between CVM stage at T2 and relapse was found (P = 0.89). Both groups had similar distributions of the CVM stages (P >0.05). Pretreatment II and postretention time were found to be correlated with long-term incisor stability (P = 0.007 and 0.034, respectively). Sex was not related to relapse (P = 0.33). Maturity of craniofacial structures at the end of treatment evaluated with the CVM method is not associated with long-term stability of incisor alignment.
-
Cossellu, G; Biagi, R; Pisani, L; Barbieri, V; Farronato, G
2014-12-01
The aim of this study was to investigate the relationship between the stages of calcification of the mandibular second molar and the stages of skeletal maturity among Italian children and young adults. Cross-sectional descriptive study. The samples were derived from panoramic radiographs and lateral cephalograms of 500 Italian subjects aged from 10 to 20 years. Dental maturity index (DM) was assessed by calcification stages of the mandibular second molars according to the Demirjian method; skeletal maturity was evaluated with cervical vertebrae maturation index (CVM) according to Hassel and Farman. The Pearson r coefficient and Spearman rank correlation coefficient were estimated to determine the relationship between DM and CVM. Skeletal maturation stages occurred earlier in females (about 6 months). A highly significant correlation between CVM and DM (0.78-0.86 cor according to Pearson test and 0.81-0.85 rho according to Spearman test) was found. DM stage E corresponds to phase CVM 1 and 2 (the phase prior to the growth spurt), DM stage F corresponds to the phase of pubertal growth spurt, stages CVM 2 and CVM 3; DM stage G is indicator of the growth spurt underway (CVM 3-4), but it can still be found during CVM 5 in females. The second mandibular molars can be considered reliable indicators for the evaluation of the growth phases. In case of females the end of the growth spurt it is not clearly associated with a dental maturity stage and needs to be stated with further parameters such as CVM.
-
[Contribution of the cervical vertebral maturation (CVM) method to dentofacial orthopedics: update].
Elhaddaoui, R; Benyahia, H; Azaroual, F; Zaoui, F
2014-11-01
The successful orthopedic treatment of skeletal Class II malocclusions is closely related to the reasoned determination of the optimal time to initiate the treatment. This is why various methods have been proposed to assess skeletal maturation, such as a hand-wrist radiograph or the cervical vertebral maturation (CVM) method. The hand-wrist radiograph was up to now the most frequently used method to assess skeletal maturation. However, the clinical and biological limitations of this technique, as well as the need to perform an additional radiograph, were reasons to develop another method to explore the maturation stages of visible cervical vertebrae on a simple lateral cephalometric radiograph. The authors compare the 2 methods and prove the greater contribution of the CVM method compared to the hand-wrist radiograph. Copyright © 2014 Elsevier Masson SAS. All rights reserved.
-
2011-01-01
Background It is desirable that those at highest risk of cardiovascular disease should have priority for preventive measures, eg. treatment with prescription drugs to modify their risk. We wanted to investigate to what extent present use of cardiovascular medication (CVM) correlates with cardiovascular risk estimated by three different risk scores (Framingham, SCORE and NORRISK) ten years ago. Methods Prospective logitudinal observational study of 20 252 participants in The Hordaland Health Study born 1950-57, not using CVM in 1997-99. Prescription data obtained from The Norwegian Prescription Database in 2008. Results 26% of men and 22% of women aged 51-58 years had started to use some CVM during the previous decade. As a group, persons using CVM scored significantly higher on the risk algorithms Framingham, SCORE and NORRISK compared to those not treated. 16-20% of men and 20-22% of women with risk scores below the high-risk thresholds for the three risk scores were treated with CVM, while 60-65% of men and 25-45% of women with scores above the high-risk thresholds received no treatment. Among women using CVM, only 2.2% (NORRISK), 4.4% (SCORE) and 14.5% (Framingham) had risk scores above the high-risk values. Low education, poor self-reported general health, muscular pains, mental distress (in females only) and a family history of premature cardiovascular disease correlated with use of CVM. Elevated blood pressure was the single factor most strongly predictive of CVM treatment. Conclusion Prescription of CVM to middle-aged individuals by large seems to occur independently of estimated total cardiovascular risk, and this applies especially to females. PMID:21366925
-
Analysis of Maternal Risk Factors Associated With Congenital Vertebral Malformations
Hesemann, Jennifer; Lauer, Emily; Ziska, Stephen; Noonan, Kenneth; Nemeth, Blaise; Scott-Schwoerer, Jessica; McCarty, Catherine; Rasmussen, Kristen; Goldberg, Jacob M.; Sund, Sarah; Eickhoff, Jens; Raggio, Cathleen L.; Giampietro, Philip F.
2014-01-01
Study Design A retrospective chart review of cases with congenital vertebral malformations (CVM) and controls with normal spine morphology. Objective To determine the relative contribution of maternal environmental factors (MEF) during pregnancy including maternal insulin dependent diabetes mellitus, valproic acid, alcohol, smoking, hyperthermia, twin gestation, assisted reproductive technology, in-vitro fertilization and maternal clomiphene usage to CVM development. Summary of Background Data Congenital vertebral malformations (CVM) represent defects in formation and segmentation of somites occurring with an estimated incidence of between 0.13–0.50 per 1000 live births. CVM may be associated with congenital scoliosis, Klippel-Feil syndrome, hemifacial microsomia and VACTERL syndromes, and represent significant morbidity due to pain and cosmetic disfigurement. Methods A multicenter retrospective chart review of 229 cases with CVM and 267 controls with normal spine morphology between the ages of 1–50 years was performed in order to obtain the odds ratio (OR) of MEF related to CVM among cases vs. controls. CVM due to an underlying syndrome associated with a known gene mutation or chromosome etiology were excluded. An imputation based analysis was performed in which subjects with no documentation of MEF history were treated as no maternal exposure.” Univariate and multivariate analysis was conducted to calculate the OR. Results Of the 229 total cases, 104 cases had single or multiple CVM without additional congenital malformations (CM) (Group 1) and 125 cases had single or multiple CVM and additional CM (Group 2). Nineteen percent of total cases had an identified MEF. The OR (95% CI, P-value) for MEF history for Group 1 was 6.0 (2.4–15.1, P<0.001) in the univariate analysis. The OR for MEF history in Group 2 was 9.1 (95%CI, P-value) (3.8–21.6, P<0.001) in the univariate analysis. The results were confirmed in the multivariate analysis, after adjusting for age, gender, and institution. Discussion These results support a hypothesis for an association between the above MEF during pregnancy and CVM and have implications for development of prevention strategies. Further prospective studies are needed to quantify association between CVM and specific MEF. PMID:23446706
-
Effect of Coriolus versicolor Mycelia Extract on Exercise Performance and Physical Fatigue in Mice.
Ho, Chun-Sheng; Tung, Yu-Tang; Kung, Woon-Man; Huang, Wen-Ching; Leung, Wing-Ki; Huang, Chi-Chang; Wu, Jyh-Horng
2017-01-01
In this study, Coriolus versicolor mycelia (CVM) was evaluated the ergogenic and anti-fatigue activities. Male ICR mice were divided into four groups ( n = 8/group) to receive vehicle or CVM by oral gavage for 4 weeks at 0, 615, 1230 or 3075 mg/kg/day, which were respectively designated the vehicle, CVM-1X, CVM-2X and CVM-5X groups. Forelimb grip strength, endurance swimming time, and levels of physical fatigue-associated parameters serum lactate, ammonia, glucose and creatine kinase (CK) after physical challenge were performed to evaluate exercise performance and anti-fatigue activity. Results revealed that the forelimb grip strength of mice in group CVM-1X, CVM-2X and CVM-5X were significantly increased by 1.20-, 1.18- and 1.23-fold, respectively, compared to the vehicle group. After the 15 minute swimming exercise, the levels of serum lactate of CVM-1X, CVM-2X and CVM-5X groups were significantly lower than the vehicle control group by 29%, 23% and 31%, respectively. The levels of ammonia in CVM-1X, CVM-2X and CVM-5X groups were significantly lowered by 22%, 25% and 41%, respectively, compared to the vehicle control group. In addition, the levels of serum CK in CVM-2X and CVM-5X groups were significantly lowered by 13% and 11%, respectively, compared to the vehicle control group. Accordingly, the supplementation with CVM has beneficial effects on performance improvement and anti-fatigue activity, and thus has great potential as a source for natural health products.
-
Effect of Coriolus versicolor Mycelia Extract on Exercise Performance and Physical Fatigue in Mice
Ho, Chun-Sheng; Tung, Yu-Tang; Kung, Woon-Man; Huang, Wen-Ching; Leung, Wing-Ki; Huang, Chi-Chang; Wu, Jyh-Horng
2017-01-01
In this study, Coriolus versicolor mycelia (CVM) was evaluated the ergogenic and anti-fatigue activities. Male ICR mice were divided into four groups (n = 8/group) to receive vehicle or CVM by oral gavage for 4 weeks at 0, 615, 1230 or 3075 mg/kg/day, which were respectively designated the vehicle, CVM-1X, CVM-2X and CVM-5X groups. Forelimb grip strength, endurance swimming time, and levels of physical fatigue-associated parameters serum lactate, ammonia, glucose and creatine kinase (CK) after physical challenge were performed to evaluate exercise performance and anti-fatigue activity. Results revealed that the forelimb grip strength of mice in group CVM-1X, CVM-2X and CVM-5X were significantly increased by 1.20-, 1.18- and 1.23-fold, respectively, compared to the vehicle group. After the 15 minute swimming exercise, the levels of serum lactate of CVM-1X, CVM-2X and CVM-5X groups were significantly lower than the vehicle control group by 29%, 23% and 31%, respectively. The levels of ammonia in CVM-1X, CVM-2X and CVM-5X groups were significantly lowered by 22%, 25% and 41%, respectively, compared to the vehicle control group. In addition, the levels of serum CK in CVM-2X and CVM-5X groups were significantly lowered by 13% and 11%, respectively, compared to the vehicle control group. Accordingly, the supplementation with CVM has beneficial effects on performance improvement and anti-fatigue activity, and thus has great potential as a source for natural health products. PMID:29104465
-
Validity and reliability of a method for assessment of cervical vertebral maturation.
Zhao, Xiao-Guang; Lin, Jiuxiang; Jiang, Jiu-Hui; Wang, Qingzhu; Ng, Sut Hong
2012-03-01
To evaluate the validity and reliability of the cervical vertebral maturation (CVM) method with a longitudinal sample. Eighty-six cephalograms from 18 subjects (5 males and 13 females) were selected from the longitudinal database. Total mandibular length was measured on each film; an increased rate served as the gold standard in examination of the validity of the CVM method. Eleven orthodontists, after receiving intensive training in the CVM method, evaluated all films twice. Kendall's W and the weighted kappa statistic were employed. Kendall's W values were higher than 0.8 at both times, indicating strong interobserver reproducibility, but interobserver agreement was documented twice at less than 50%. A wide range of intraobserver agreement was noted (40.7%-79.1%), and substantial intraobserver reproducibility was proved by kappa values (0.53-0.86). With regard to validity, moderate agreement was reported between the gold standard and observer staging at the initial time (kappa values 0.44-0.61). However, agreement seemed to be unacceptable for clinical use, especially in cervical stage 3 (26.8%). Even though the validity and reliability of the CVM method proved statistically acceptable, we suggest that many other growth indicators should be taken into consideration in evaluating adolescent skeletal maturation.
-
Comparison of three methods to assess individual skeletal maturity.
Pasciuti, Enzo; Franchi, Lorenzo; Baccetti, Tiziano; Milani, Silvano; Farronato, Giampietro
2013-09-01
The knowledge of facial growth and development is fundamental to determine the optimal timing for different treatment procedures in the growing patient. To analyze the reproducibility of three methods in assessing individual skeletal maturity, and to evaluate any degree of concordance among them. In all, 100 growing subjects were enrolled to test three methods: the hand-wrist, cervical vertebral maturation (CVM), and medial phalanges of the third finger method (MP3). Four operators determined the skeletal maturity of the subjects to evaluate the reproducibility of each method. After 30 days the operators repeated the analysis to assess the repeatability of each method. Finally, one operator examined all subjects' radiographs to detect any concordance among the three methods. The weighted kappa values for inter-operator variability were 0.94, 0.91, and 0.90, for the WRI, CVM, and MP3 methods, respectively. The weighted kappa values for intra-operator variability were 0.92, 0.91, and 0.92, for the WRI, CVM, and MP3 methods, respectively. The three methods revealed a high degree of repeatability and reproducibility. Complete agreement among the three methods was observed in 70% of the analyzed samples. The CVM method has the advantage of not necessitating an additional radiograph. The MP3 method is a simple and practical alternative as it requires only a standard dental x-ray device.
-
Soegiharto, Benny M; Cunningham, Susan J; Moles, David R
2008-08-01
The purpose of this study was to describe the stages of skeletal maturity of Deutero-Malay Indonesian children according to the hand-wrist and cervical vertebrae methods and to compare them with white children. The study included 2167 patients with hand-wrist radiographs and lateral cephalometric radiographs. Of these, there were 648 Indonesian boys, 303 white boys (age range of boys, 10-17 years), 774 Indonesian girls, and 442 white girls (age range of girls, 8-15 years). The skeletal maturation index (SMI) was used to evaluate the stages of skeletal maturity from hand-wrist radiographs, and the cervical vertebrae maturation (CVM) index was used to evaluate the stages of skeletal maturity from lateral cephalometric radiographs. One observer made all observations, and a repeatability study was undertaken. Box-and-whisker plots were used to show the age distribution on attainment of each maturation stage based on the SMI and CVM. On average, both the SMI and the CVM showed that white children attained each maturation stage about 0.5 to 1 year earlier than their Indonesian peers, although the differences were less obvious in girls than in boys. Multiple regression analysis was used to predict the SMI from the chronologic age. Both the Indonesian and the white boys groups showed a good relationship between predicted SMI and chronologic age (R(2) = 0.728 and 0.739, respectively), as did the Indonesian and white girls groups (R(2) = 0.755 and 0.748, respectively). Further multiple regression analyses used to investigate the differences in the ages of attainment of skeletal development between Indonesian and white subjects indicated that, across the age ranges investigated, on average for a particular age, the white boys were 1 SMI stage ahead of the Indonesian boys, and the white girls were about 0.5 SMI stage ahead of their Indonesian peers. Because the CVM has only 5 categories, it was not considered appropriate to use this form of multiple regression analysis. The findings confirmed marked variations in the chronologic ages for each skeletal maturity stage and also showed differences between the timing of skeletal maturity with both the SMI and the CVM between the sexes and the ethnic groups. These differences should be considered during orthodontic diagnosis and treatment planning.
-
Nunn, Kenetta L; Wang, Ying-Ying; Harit, Dimple; Humphrys, Michael S; Ma, Bing; Cone, Richard; Ravel, Jacques; Lai, Samuel K
2015-10-06
Cervicovaginal mucus (CVM) can provide a barrier that precludes HIV and other sexually transmitted virions from reaching target cells in the vaginal epithelium, thereby preventing or reducing infections. However, the barrier properties of CVM differ from woman to woman, and the causes of these variations are not yet well understood. Using high-resolution particle tracking of fluorescent HIV-1 pseudoviruses, we found that neither pH nor Nugent scores nor total lactic acid levels correlated significantly with virus trapping in unmodified CVM from diverse donors. Surprisingly, HIV-1 was generally trapped in CVM with relatively high concentrations of d-lactic acid and a Lactobacillus crispatus-dominant microbiota. In contrast, a substantial fraction of HIV-1 virions diffused rapidly through CVM with low concentrations of d-lactic acid that had a Lactobacillus iners-dominant microbiota or significant amounts of Gardnerella vaginalis, a bacterium associated with bacterial vaginosis. Our results demonstrate that the vaginal microbiota, including specific species of Lactobacillus, can alter the diffusional barrier properties of CVM against HIV and likely other sexually transmitted viruses and that these microbiota-associated changes may account in part for the elevated risks of HIV acquisition linked to bacterial vaginosis or intermediate vaginal microbiota. Variations in the vaginal microbiota, especially shifts away from Lactobacillus-dominant microbiota, are associated with differential risks of acquiring HIV or other sexually transmitted infections. However, emerging evidence suggests that Lactobacillus iners frequently colonizes women with recurring bacterial vaginosis, raising the possibility that L. iners may not be as protective as other Lactobacillus species. Our study was designed to improve understanding of how the cervicovaginal mucus barrier against HIV may vary between women along with the vaginal microbiota and led to the finding that the vaginal microbiota, including specific species of Lactobacillus, can directly alter the diffusional barrier properties of cervicovaginal mucus. This work advances our understanding of the complex barrier properties of mucus and highlights the differential protective ability of different species of Lactobacillus, with Lactobacillus crispatus and possibly other species playing a key role in protection against HIV and other sexually transmitted infections. These findings could lead to the development of novel strategies to protect women against HIV. Copyright © 2015 Nunn et al.
-
Coherent Anomaly Method Calculation on the Cluster Variation Method. II.
NASA Astrophysics Data System (ADS)
Wada, Koh; Watanabe, Naotosi; Uchida, Tetsuya
The critical exponents of the bond percolation model are calculated in the D(= 2,3,…)-dimensional simple cubic lattice on the basis of Suzuki's coherent anomaly method (CAM) by making use of a series of the pair, the square-cactus and the square approximations of the cluster variation method (CVM) in the s-state Potts model. These simple approximations give reasonable values of critical exponents α, β, γ and ν in comparison with ones estimated by other methods. It is also shown that the results of the pair and the square-cactus approximations can be derived as exact results of the bond percolation model on the Bethe and the square-cactus lattice, respectively, in the presence of ghost field without recourse to the s→1 limit of the s-state Potts model.
-
Zhang, Di-qing; Chen, Zi-qiang; Li, Ming
2011-03-01
To investigate the reliability of cervical vertebral maturation (CVM) and to verify the possibility in the growth evaluation of female adolescent idiopathic scoliosis patients as a helpful supplementary to the Risser sign. Coronal and lateral full-length spine X-ray film and left hand-wrist radiographs of 77 female adolescent patients with idiopathic scoliosis were selected from January 2010 to October 2010. The interval period between lateral length of the spine and left hand-wrist radiographs did not exceed 3 months. The CVM was assessed by a method developed by Baccetti and co-workers, whereas hand-wrist maturation was assessed by Fishman's method. The results were analyzed by Spearman correlation with patients Risser sign, chronological age, and menarche period. There were strong correlations between CVM and SMI or Risser sign (r = 0.862 and 0.762, P < 0.01). While in 26 patients whose Risser sign were 0-I, the correlation between CVM and SMI was more pronounced (r = 0.761, P < 0.01), compared with the correlation between Risser sign and SMI (r = 0.641, P < 0.01). CVM is a valid indicator of skeletal growth evaluation and can be used as a helpful supplementary to Risser sign.
-
2010-01-01
Background Bovine leukocyte adhesion deficiency (BLAD), deficiency of uridine monophosphate synthase (DUMPS), complex vertebral malformation (CVM), bovine citrullinaemia (BC) and factor XI deficiency (FXID) are autosomal recessive hereditary disorders, which have had significant economic impact on dairy cattle breeding worldwide. In this study, 350 Holstein cows reared in Turkey were screened for BLAD, DUMPS, CVM, BC and FXID genotypes to obtain an indication on the importance of these defects in Turkish Holsteins. Methods Genomic DNA was obtained from blood and the amplicons of BLAD, DUMPS, CVM, BC and FXID were obtained by using PCR. PCR products were digested with TaqI, AvaI and AvaII restriction enzymes for BLAD, DUMPS, and BC, respectively. These digested products and PCR product of FXID were analyzed by agarose gel electrophoresis stained with ethidium bromide. CVM genotypes were detected by DNA sequencing. Additionally, all genotypes were confirmed by DNA sequencing to determine whether there was a mutant allele or not. Results Fourteen BLAD, twelve CVM and four FXID carriers were found among the 350 Holstein cows examined, while carriers of DUMPS and BC were not detected. The mutant allele frequencies were calculated as 0.02, 0.017, and 0.006 for BLAD, CVM and FXID, respectively with corresponding carrier prevalence of 4.0% (BLAD), 3.4% (CVM) and 1.2% (FXID). Conclusion This study demonstrates that carriers of BLAD, CVM and FXID are present in the Turkish Holstein population, although at a low frequency. The actual number of clinical cases is unknown, but sporadic cases may appear. As artificial insemination is widely used in dairy cattle breeding, carriers of BLAD, CVM and FXID are likely present within the population of breeding sires. It is recommended to screen breeding sires for these defective genes in order to avoid an unwanted spread within the population. PMID:20929557
-
NASA Astrophysics Data System (ADS)
Cadeville, M. C.; Pierron-Bohnes, V.; Bouzidi, L.; Sanchez, J. M.
1993-01-01
Local and average electronic and magnetic properties of transition metal alloys are strongly correlated to the distribution of atoms on the lattice sites. The ability of some systems to form long range ordered structures at low temperature allows to discuss their properties in term of well identified occupation operators as those related to long range order (LRO) parameters. We show that using theoretical determinations of these LRO parameters through statistical models like the cluster variation method (CVM) developed to simulate the experimental phase diagrams, we are able to reproduce a lot of physical properties. In this paper we focus on two points: (i) a comparison between CVM results and an experimental determination of the LRO parameter by NMR at 59Co in a CoPt3 compound, and (ii) the modelling of the resistivity of ferromagnetic and paramagnetic intermetallic compounds belonging to Co-Pt, Ni-Pt and Fe-Al systems. All experiments were performed on samples in identified thermodynamic states, implying that kinetic effects are thoroughly taken into account.
-
New method for evaluation of cervical vertebral maturation based on angular measurements.
Alhadlaq, Adel M; Al-Shayea, Eman I
2013-04-01
To investigate the validity of a new approach to assess the cervical vertebral maturation based on angular measurements of the lower border concavity of cervical vertebral bodies. Hand-wrist and lateral cephalometric radiographs of 197 male subjects with age range of 10-15 years attending the orthodontic clinic at King Saud University, Riyadh, Kingdom of Saudi Arabia were utilized. The study was carried out between September 2009 and May 2011. The study sample was divided into 6 groups (group 1: 10 years to group 6: 15 years) based on the chronological age of the subject. The skeletal age of the subjects was determined using Greulich and Pyle's standard radiographic atlas, and skeletal maturation was assessed by Fishman's skeletal maturity indicators. The cervical vertebral maturation (CVM) of subjects was determined using angular measurements of the second, third, and fourth cervical vertebral bodies. The validity of the newly developed method was assessed by examining the correlation between CVM stages determined by the angular measurements and the skeletal maturation level as determined by the standard hand-wrist methods. A significant correlation (r=0.94) was found between the angular CVM stages and the skeletal age determined by Greulich and Pyle's atlas from hand-wrist radiographs. Also, a high correlation (r=0.94) was found between the angular CVM stages and the Fishman's hand-wrist skeletal maturity indicators. The new angular measurement approach to determine CVM is valid and has the potential to be applied in assessing skeletal maturity level in growing male children.
-
Lake Powell management alternatives and values: CVM estimates of recreation benefits
Douglas, A.J.; Harpman, D.A.
2004-01-01
This paper presents data analyses based on information gathered from a recreation survey distributed during the spring of 1997 at Lake Powell. Recreation-linked management issues are the foci of the survey and this discussion. Survey responses to contingent valuation method (CVM) queries included in the questionnaire quantify visitor recreation values. The CVM estimates of the benefits provided by potential resource improvements are compared with the costs of the improvements in a benefit-cost analysis. The CVM questions covered three resources management issues including water quality improvement, sport fish harvest enhancement, and archeological site protection and restoration. The estimated benefits are remarkably high relative to the costs and range from $6 to $60 million per year. The dichotomous choice format was used in each of three resource CVM question scenarios. There were two levels of enhancement for each resource. There are, therefore, several consistency requirements—some of them unique to the dichotomous choice format—that the data and benefit estimates must satisfy. These consistency tests are presented in detail in the ensuing analysis.
-
Handgrip force steadiness in young and older adults: a reproducibility study.
Blomkvist, Andreas W; Eika, Fredrik; de Bruin, Eling D; Andersen, Stig; Jorgensen, Martin
2018-04-02
Force steadiness is a quantitative measure of the ability to control muscle tonus. It is an independent predictor of functional performance and has shown to correlate well with different degrees of motor impairment following stroke. Despite being clinically relevant, few studies have assessed the validity of measuring force steadiness. The aim of this study was to explore the reproducibility of handgrip force steadiness, and to assess age difference in steadiness. Intrarater reproducibility (the degree to which a rating gives consistent result on separate occasions) was investigated in a test-retest design with seven days between sessions. Ten young and thirty older adults were recruited and handgrip steadiness was tested at 5%, 10% and 25% of maximum voluntary contraction (MVC) using Nintendo Wii Balance Board (WBB). Coefficients of variation were calculated from the mean force produced (CVM) and the target force (CVT). Area between the force curve and the target force line (Area) was also calculated. For the older adults we explored reliability using intraclass correlation coefficient (ICC) and agreement using standard error of measurement (SEM), limits of agreement (LOA) and smallest real difference (SRD). A systematic improvement in handgrip steadiness was found between sessions for all measures (CVM, CVT, Area). CVM and CVT at 5% of MVC showed good to high reliability, while Area had poor reliability for all percentages of MVC. Averaged ICC for CVM, CVT and Area was 0.815, 0.806 and 0.464, respectively. Averaged ICC on 5%, 10%, and 25% of MVC was 0.751, 0.667 and 0.668, respectively. Measures of agreement showed similar trends with better results for CVM and CVT than for Area. Young adults had better handgrip steadiness than older adults across all measures. The CVM and CVT measures demonstrated good reproducibility at lower percentages of MVC using the WBB, and could become relevant measures in the clinical setting. The Area measure had poor reproducibility. Young adults have better handgrip steadiness than old adults.
-
NASA Astrophysics Data System (ADS)
Wada, Koh; Watanabe, Naotosi; Uchida, Tetsuya
1991-10-01
The critical exponents of the bond percolation model are calculated in the D(=2, 3, \\cdots)-dimensional simple cubic lattice on the basis of Suzuki’s coherent anomaly method (CAM) by making use of a series of the pair, the square-cactus and the square approximations of the cluster variation method (CVM) in the s-state Potts model. These simple approximations give reasonable values of critical exponents α, β, γ and ν in comparison with ones estimated by other methods. It is also shown that the results of the pair and the square-cactus approximations can be derived as exact results of the bond percolation model on the Bethe and the square-cactus lattice, respectively, in the presence of ghost field without recourse to the s→1 limit of the s-state Potts model.
-
ERIC Educational Resources Information Center
Ajayi, A. O.
2006-01-01
This study assessed farmers' willingness to pay (WTP) for extension services. The Contingent Valuation Method (CVM) was used to assess the amount which farmers are willing to pay. Primary data on the demographic, socio-economic variables of farmers and their WTP were collected from 228 farmers selected randomly in a stage-wise sampling procedure…
-
Chen, Li-Li; Xu, Tian-Min; Jiang, Jiu-Hui; Zhang, Xing-Zhong; Lin, Jiu-Xiang
2008-12-01
The purpose of this study was to establish a quantitative cervical vertebral maturation (CVM) system for adolescents with normal occlusion. Mixed longitudinal data were used. The subjects included 87 children and adolescents from 8 to 18 years old with normal occlusion (32 boys, 55 girls) selected from 901 candidates. Sequential lateral cephalograms and hand-wrist films were taken once a year for 6 years. The lateral cephalograms of all subjects were divided into 11 maturation groups according to the Fishman skeletal maturity indicators. The morphologic characteristics of the second, third, and fourth cervical vertebrae at 11 developmental stages were measured and analyzed. Three characteristic parameters (H4/W4, AH3/PH3, @2) were selected to determine the classification of CVM. With 3 morphologic variables, the quantitative CVM system including 4 maturational stages was established. An equation that can accurately estimate the maturation of the cervical vertebrae was established: CVM stage=-4.13+3.57xH4/W4+4.07xAH3/PH3+0.03x@2. The quantitative CVM method is an efficient, objective, and relatively simple approach to assess the level of skeletal maturation during adolescence.
-
Trakinienė, Giedrė; Smailienė, Dalia; Kučiauskienė, Ainė
2016-08-01
The objective of this study was to evaluate whether the calcification stages of maxillary canine, mandibular second molar, and mandibular third molar can be used for assessment of growth phase. The study group consisted of 274 subjects. Pre-treatment digital panoramic and lateral cephalometric radiographs of the patients were analysed. The patients' age was ranging from 7 to 19 years. Right maxillary canine, mandibular second molar and third molar were used as a sample. The teeth mineralization was assessed using modification of Gleiser and Hunt method. The skeletal maturation was assessed by the cervical vertebrae maturation (CVM) method. A significant association was found between CVM stage 2 and maxillary canine (UC) stage 4, mandibular second molar (LM2) stage 4, and mandibular third molar (LM3) stage 1. CVM stage 3 corresponded with UC stage 5, LM2 stage 5, LM3 stage 2. CVM stage 4 matched with UC stage 5, LM2 stage 6 and LM3 stage 3. The highest correlations between CVM and calcification stages were in the group of the maxillary canine (r = 0.812, P < 0.01) and mandibular second molar (r = 0.824, P < 0.01). Limitation of our study was that the study sample was not very big and the distribution value in the groups was very high, so it was impossible to check more statistical parameters. The calcification stages of UC, LM2, and LM3 as indicators of skeletal maturity could be clinically used with caution, until this method is verified with a larger sample group. © The Author 2015. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com.
-
A semi-automated method for bone age assessment using cervical vertebral maturation.
Baptista, Roberto S; Quaglio, Camila L; Mourad, Laila M E H; Hummel, Anderson D; Caetano, Cesar Augusto C; Ortolani, Cristina Lúcia F; Pisa, Ivan T
2012-07-01
To propose a semi-automated method for pattern classification to predict individuals' stage of growth based on morphologic characteristics that are described in the modified cervical vertebral maturation (CVM) method of Baccetti et al. A total of 188 lateral cephalograms were collected, digitized, evaluated manually, and grouped into cervical stages by two expert examiners. Landmarks were located on each image and measured. Three pattern classifiers based on the Naïve Bayes algorithm were built and assessed using a software program. The classifier with the greatest accuracy according to the weighted kappa test was considered best. The classifier showed a weighted kappa coefficient of 0.861 ± 0.020. If an adjacent estimated pre-stage or poststage value was taken to be acceptable, the classifier would show a weighted kappa coefficient of 0.992 ± 0.019. Results from this study show that the proposed semi-automated pattern classification method can help orthodontists identify the stage of CVM. However, additional studies are needed before this semi-automated classification method for CVM assessment can be implemented in clinical practice.
-
John Loomis; Armando Gonzalez-Caban; Joseph Champ
2011-01-01
Over the past four decades teh contingent valuation method (CVM) has become a technique frequently used by economists to estimate willingness-to-pay (WTP) for improvements in environmental quality and prot3tion of natural resources. The CVM was originall applied to estmate recreation use values (Davis, 1963; Hammack and Brown, 1974)and air quality (Brookshire et al....
-
[Sincerity of effort: isokinetic evaluation of knee extension].
Colombo, R; Demaiti, G; Sartorio, F; Orlandini, D; Vercelli, S; Ferriero, G
2008-01-01
The aim of this study was to find a reliable method to evaluate the sincerity of the muscular maximal effort performed in a dynamometric isokinetic test of knee flexion-extension. The coefficient of variation of the peak torque (CV) and 3 new indices were analysed: (1) the average coefficient of variation calculated on the complete peak torque curve (CVM); (2) the slope of the regression line in an endurance test (PRR); (3) the correlation coefficient of the peak torques in the same endurance test (CCR). Twenty healthy subjects underwent assessment in two different trials, maximal (MX) and 50% submaximal (SMX), with 20 minutes of rest between trials. Each trial consisted of 4 tests, each of 3 repetitions, at angular speed of 30, 180, 30, and 180 degrees/s, respectively, and 1 test of 15 repetitions at 240 degrees/s. Our findings confirmed the ability of CV to detect a high percentage of sincere efforts: at 30 degrees/s Sensibility (Sns)=100% and Specificity (Spc)=70%; at 180 degrees/s Sns=75%, Spc=95%. The 3 new indices here proposed showed high characteristics of Sns and Spc, generally better than those of CV. CVM showed at 180 degrees/s Sns=90% and Spc=100%, while at 30 degrees/s Sns=90%, Spc=75%. PRR was the best index identifying all the efforts, except one (Sns=100%, Spc=95%). The CCR coefficient showed Sns and Spc values both of 90%.
-
Shi, Yingzhong; Chung, Fu-Lai; Wang, Shitong
2015-09-01
Recently, a time-adaptive support vector machine (TA-SVM) is proposed for handling nonstationary datasets. While attractive performance has been reported and the new classifier is distinctive in simultaneously solving several SVM subclassifiers locally and globally by using an elegant SVM formulation in an alternative kernel space, the coupling of subclassifiers brings in the computation of matrix inversion, thus resulting to suffer from high computational burden in large nonstationary dataset applications. To overcome this shortcoming, an improved TA-SVM (ITA-SVM) is proposed using a common vector shared by all the SVM subclassifiers involved. ITA-SVM not only keeps an SVM formulation, but also avoids the computation of matrix inversion. Thus, we can realize its fast version, that is, improved time-adaptive core vector machine (ITA-CVM) for large nonstationary datasets by using the CVM technique. ITA-CVM has the merit of asymptotic linear time complexity for large nonstationary datasets as well as inherits the advantage of TA-SVM. The effectiveness of the proposed classifiers ITA-SVM and ITA-CVM is also experimentally confirmed.
-
Litsas, George; Lucchese, Alessandra
2016-01-01
Purpose: To investigate the relationship between dental, chronological, and cervical vertebral maturation growth in the peak growth period, as well as to study the association between the dental calcification phases and the skeletal maturity stages during the same growth period. Methods: Subjects were selected from orthodontic pre-treatment cohorts consisting of 420 subjects where 255 were identified and enrolled into the study, comprising 145 girls and 110 boys. The lateral cephalometric and panoramic radiographs were examined from the archives of the Department of Orthodontics, Aristotle University of Thessaloniki, Greece. Dental age was assessed according to the method of Demirjian, and skeletal maturation according to the Cervical Vertebral Maturation Method. Statistical elaboration included Spearman Brown formula, descriptive statistics, Pearson’s correlation coefficient and regression analysis, paired samples t-test, and Spearman’s rho correlation coefficient. Results: Chronological and dental age showed a high correlation for both gender(r =0.741 for boys, r = 0.770 for girls, p<0.001). The strongest correlation was for the CVM Stage IV for both males (r=0.554) and females (r=0.68). The lowest correlation was for the CVM Stage III in males (r=0.433, p<0.001) and for the CVM Stage II in females (r=0.393, p>0.001). The t-test revealed statistically significant differences between these variables (p<0.001) during the peak period. A statistically significant correlation (p<0.001) between tooth calcification and CVM stages was determined. The second molars showed the highest correlation with CVM stages (CVMS) (r= 0.65 for boys, r = 0.72 for girls). Conclusion: Dental age was more advanced than chronological for both boys and girls for all CVMS. During the peak period these differences were more pronounced. Moreover, all correlations between skeletal and dental stages were statistically significant. The second molars showed the highest correlation whereas the canines showed the lowest correlation for both gender. PMID:27335610
-
Comparisons of modified Vasco X-2 and AISI 9310 gear steels
NASA Technical Reports Server (NTRS)
Townsend, D. P.; Zaretsky, E. V.
1980-01-01
Endurance tests were conducted with four groups of spur gears manufactured from three heats of consumable electrode vacuum melted (CVM) modified Vasco X-2. Endurance tests were also conducted with gears manufactured from CVM AISI 9310. Bench type rolling element fatigue tests were conducted with both materials. Hardness measurements were made to 811 K. There was no statistically significant life difference between the two materials. Life differences between the different heats of modified Vasco X-2 can be attributed to heat treat variation and resultant hardness. Carburization of gear flanks only can eliminate tooth fracture as a primary failure mode for modified Vasco X-2. However, a tooth surface fatigue spall can act as a nucleus of a tooth fracture failure for the modified Vasco X-2.
-
Shapland, Fiona; Lewis, Mary E
2014-01-01
The assessment of age-at-death in non-adult skeletal remains is under constant review. However, in many past societies an individual's physical maturation may have been more important in social terms than their exact age, particularly during the period of adolescence. In a recent article (Shapland and Lewis: Am J Phys Anthropol 151 (2013) 302-310) highlighted a set of dental and skeletal indicators that may be useful in mapping the progress of the pubertal growth spurt. This article presents a further skeletal indicator of adolescent development commonly used by modern clinicians: cervical vertebrae maturation (CVM). This method is applied to a collection of 594 adolescents from the medieval cemetery of St. Mary Spital, London. Analysis reveals a potential delay in ages of attainment of the later CVM stages compared with modern adolescents, presumably reflecting negative environmental conditions for growth and development. The data gathered on CVM is compared to other skeletal indicators of pubertal maturity and long bone growth from this site to ascertain the usefulness of this method on archaeological collections. Copyright © 2013 Wiley Periodicals, Inc.
-
Chongcharueyskul, Pathomporn; Wangsrimonkol, Tasanee; Pisek, Poonsak; Pisek, Araya; Manosudprasit, Montian
2015-08-01
To examine correlations between cervical vertebral maturation stages (CVMs) and dental development stages, and cervical vertebral maturation (CVM) stage 6 and completion of root formation of mandibular third molar in Thai cleft patients. Lateral cephalograms of 366 cleft subjects aged 7-9 years were assessed for CVMs using Baccetti method. Calcication stages of all left mandibular teeth within each CVMs were assessed from panoramic films using Demirjian method. Spearman rank correlation coefficients comparing CVMs and teeth were 0.51-0.79 (p<0.001). Second molar had the highest and central incisor had the lowest correlations. In CVMs 6, 2.9% of third molars had completed root formation. However, only CVMs 6 could be predicted from third molar stage G that had a high likelihood ratio (30.94). Dental development was highly correlated with CVM in clefts. Third molar stage G could predict completed growth of mandible in individual patients, but it should be combined with other maturation indicators.
-
Adnane, Mounir; Chapwanya, Aspinas; Kaidi, Rachid; Meade, Kieran G; O'Farrelly, Cliona
2017-11-01
Endometritis significantly impacts fertility and milk yield, thus reducing profitability of the dairy production. In cows that develop endometritis, normal postpartum endometrial inflammation is dysregulated. Here, we propose that endometrial inflammation is reflected in cervico-vaginal mucus (CVM) which could therefore be used as a prognostic tool. CVM was collected from 20 dairy cows (10 with clinical endometritis and 10 healthy) 7 and 21 days postpartum (DPP). Polymorphonuclear (PMN), mononuclear leukocyte and epithelial cells were counted, total protein levels were estimated and levels of IL-1β, IL-6, IL-8, serum amyloid A (SAA), haptoglobin (Hp) and C5b were analyzed by ELISA in CVM. PMN were consistently high in CVM from 7 to 21 DPP, but were higher in CVM from cows with clinical endometritis 21 DPP compared with healthy cows. In contrast, there were more epithelial cells in healthy cows 21 DPP than in clinical endometritis animals. Total protein levels decreased significantly in CVM from healthy cows between days 7 and 21 postpartum. All inflammatory biomarkers except C5b, remained high in cows with clinical endometritis from 7 to 21 DPP, indicating sustained and chronic endometrial inflammation. IL1, IL-6, IL-8 and Hp levels were higher in CVM from cows with clinical endometritis compared to healthy cows 21 DPP. Interestingly IL-1β levels were raised in CVM from clinical endometritis but not in healthy cows 7 DPP suggesting that early measurement of IL-1β levels might provide a useful predictive marker of clinical endometritis. In contrast, SAA and C5b levels were increased in healthy cows 21 DPP, compared to cows with clinical endometritis suggesting that these acute phase proteins might have an anti-inflammatory role. Our results show that CVM is convenient for profiling disease-associated changes in key inflammatory molecules postpartum and reaffirms that sustained inflammation is a key feature of clinical endometritis in the dairy cow. Copyright © 2017. Published by Elsevier Inc.
-
Altınel, Ahmet
2017-01-01
Complex vertebral malformation (CVM) is an inherited, autosomal recessive disorder of Holstein cattle. The aim of this study was to compare sensitivity, specificity, positive and negative predictive values, accuracy, and rapidity of allele-specific polymerase chain reaction (AS-PCR), created restriction-site PCR (CRS-PCR), and PCR with primer-introduced restriction analysis (PCR-PIRA), three methods used in identification of CVM carriers in a Holstein cattle population. In order to screen for the G>T mutation in the solute carrier family 35 member A3 (SLC35A3) gene, DNA sequencing as the gold standard method was used. The prevalence of carriers and the mutant allele frequency were 3.2% and 0.016, respectively, among Holstein cattle in the Thrace region of Turkey. Among the three methods, the fastest but least accurate was AS-PCR. Although the rapidity of CRS-PCR and PCR-PIRA were nearly equal, the accuracy of PCR-PIRA was higher than that of CRS-PCR. Therefore, among the three methods, PCR-PIRA appears to be the most efficacious for screening of mutant alleles when identifying CVM carriers in a Holstein cattle population. PMID:28927256
-
Development of plasma chemical vaporization machining
NASA Astrophysics Data System (ADS)
Mori, Yuzo; Yamauchi, Kazuto; Yamamura, Kazuya; Sano, Yasuhisa
2000-12-01
Conventional machining processes, such as turning, grinding, or lapping are still applied for many materials including functional ones. But those processes are accompanied with the formation of a deformed layer, so that machined surfaces cannot perform their original functions. In order to avoid such points, plasma chemical vaporization machining (CVM) has been developed. Plasma CVM is a chemical machining method using neutral radicals, which are generated by the atmospheric pressure plasma. By using a rotary electrode for generation of plasma, a high density of neutral radicals was formed, and we succeeded in obtaining high removal rate of several microns to several hundred microns per minute for various functional materials such as fused silica, single crystal silicon, molybdenum, tungsten, silicon carbide, and diamond. Especially, a high removal rate equal to lapping in the mechanical machining of fused silica and silicon was realized. 1.4 nm (p-v) was obtained as a surface roughness in the case of machining a silicon wafer. The defect density of a silicon wafer surface polished by various machining method was evaluated by the surface photo voltage spectroscopy. As a result, the defect density of the surface machined by plasma CVM was under 1/100 in comparison with the surface machined by mechanical polishing and argon ion sputtering, and very low defect density which was equivalent to the chemical etched surface was realized. A numerically controlled CVM machine for x-ray mirror fabrication is detailed in the accompanying article in this issue.
-
Transverse maxillary deficit and its influence on the cervical vertebrae maturation index.
Cossellu, G; Farronato, G; Nicotera, O; Biagi, R
2016-06-01
The aim of this study is to evaluate whether a transverse maxillary deficit can cause an alteration of vertebral development and therefore of the skeletal maturation comparing the cervical maturation stages index with the hand-wrist index. For the study were selected 200 patients aged 7-14 years, equally distributed by gender and divided into 100 study subjects with maxillary deficit and 100 controls without maxillary deficit. The skeletal maturation index (SM according to Fishman) was evaluated and compared with the hand-wrist x-rays and the cervical vertebrae maturation (CVM according to Hassel and Farmann). Forty-one per cent of the subjects in the test group show a discrepancy between CVM and SM. Among these 73% (30 subjects) present an advanced stage of CVM compared with the corresponding SM. Only 16% of the subjects in the control group show a discrepancy between CVM and SM. Among these 69% (11 subjects) appear in an advanced CVM stage. The analysis of the CVM stage in subjects with transverse maxillary deficit appears to be altered compared with the SM identified through a hand-wrist x-ray. In the case of individuals with transverse maxillary deficit it is advisable to use also a hand-wrist x-ray, thus not relying only on CVM for the evaluation of the skeletal growth stages.
-
Clarke, Philip M
2002-03-01
In this study, the convergent validity of the contingent valuation method (CVM) and travel cost method (TCM) is tested by comparing estimates of the willingness to pay (WTP) for improving access to mammographic screening in rural areas of Australia. It is based on a telephone survey of 458 women in 19 towns, in which they were asked about their recent screening behaviour and their WTP to have a mobile screening unit visit their nearest town. After eliminating missing data and other non-usable responses the contingent valuation experiment and travel cost model were based on information from 372 and 319 women, respectively. Estimates of the maximum WTP for the use of mobile screening units were derived using both methods and compared. The highest mean WTP estimated using the TCM was $83.10 (95% C.I. $99.06-$68.53), which is significantly less than the estimate of $148.09 ($131.13-$166.60) using the CVM. This could be due to the CVM estimates also reflecting non-use values such as altruism, or a range of potential biases that are known to affect both methods. Further tests of validity are required in order to gain a greater understanding of the relationship between these two methods of estimating WTP. Copyright 2001 John Wiley & Sons, Ltd.
-
Meydan, Hasan; Yildiz, Mehmet A; Agerholm, Jørgen S
2010-10-07
Bovine leukocyte adhesion deficiency (BLAD), deficiency of uridine monophosphate synthase (DUMPS), complex vertebral malformation (CVM), bovine citrullinaemia (BC) and factor XI deficiency (FXID) are autosomal recessive hereditary disorders, which have had significant economic impact on dairy cattle breeding worldwide. In this study, 350 Holstein cows reared in Turkey were screened for BLAD, DUMPS, CVM, BC and FXID genotypes to obtain an indication on the importance of these defects in Turkish Holsteins. Genomic DNA was obtained from blood and the amplicons of BLAD, DUMPS, CVM, BC and FXID were obtained by using PCR. PCR products were digested with TaqI, AvaI and AvaII restriction enzymes for BLAD, DUMPS, and BC, respectively. These digested products and PCR product of FXID were analyzed by agarose gel electrophoresis stained with ethidium bromide. CVM genotypes were detected by DNA sequencing. Additionally, all genotypes were confirmed by DNA sequencing to determine whether there was a mutant allele or not. Fourteen BLAD, twelve CVM and four FXID carriers were found among the 350 Holstein cows examined, while carriers of DUMPS and BC were not detected. The mutant allele frequencies were calculated as 0.02, 0.017, and 0.006 for BLAD, CVM and FXID, respectively with corresponding carrier prevalence of 4.0% (BLAD), 3.4% (CVM) and 1.2% (FXID). This study demonstrates that carriers of BLAD, CVM and FXID are present in the Turkish Holstein population, although at a low frequency. The actual number of clinical cases is unknown, but sporadic cases may appear. As artificial insemination is widely used in dairy cattle breeding, carriers of BLAD, CVM and FXID are likely present within the population of breeding sires. It is recommended to screen breeding sires for these defective genes in order to avoid an unwanted spread within the population.
-
Safavi, Seyed Mohammadreza; Beikaii, Hanie; Hassanizadeh, Raheleh; Younessian, Farnaz; Baghban, Alireza Akbarzadeh
2015-01-01
Correlation between chronological age at different stages of cervical vertebral maturation (CVM) is important in clinical orthodontic practice. The objective of this study was to evaluate the correlation between CVM stage and chronological age in a group of Iranian female patients. This study was conducted on 196 digital lateral cephalometry of female patients with the age ranged 9-14 years. The CVM stage was determined with two calibrated examiners, using the method developed by Baccetti and its correlation with mean chronological age was assessed by the Spearman rank-order. The intra and inter-agreements were evaluated by weighted Kappa statistics in overall diagnosis of stages, in addition to determination of presence or absent of concavities at the lower border of second, third and fourth cervical vertebrae and the shapes of the third and fourth vertebrae. P < 0.05 was considered as significant. The correlation coefficient between CVM stages and chronological age was relatively low (r = 0.62). The least amount of inter-observer agreement was determined to be at the clinical decision of the shape of the fourth vertebra. Regarding the low reported correlation, the concomitant usage of other skeletal indicators seems necessary for precise determination of physiological age of the patients.
-
Vitrigel-eye irritancy test method using HCE-T cells.
Yamaguchi, Hiroyuki; Kojima, Hajime; Takezawa, Toshiaki
2013-10-01
We previously reported that the time-dependent relative changes of transepithelial electrical resistance (TEER) after exposing four different chemicals to a human corneal epithelium (HCE) model were well correlated to the potential of ocular irritancy. Meanwhile, we recently developed a collagen vitrigel membrane (CVM) chamber possessing a scaffold composed of high-density collagen fibrils equivalent to connective tissues in vivo as a three-dimensional culture tool. The CVM chamber is useful for biomedical assays and immunohistology using cryosections that are inappropriate to be performed using the conventional Millicell chamber with a polyethylene terephthalate membrane. In this study, we aimed to develop a new eye irritancy test (EIT) method called "Vitrigel-EIT method" that can facilitate to briefly and accurately estimate the widespread irritancy of test chemicals by applying the TEER assay system to a HCE model fabricated in the CVM chamber. HCE-T cells (a HCE-derived cell strain) were cultured in the CVM chamber for 6 days, and consequently, the Vitrigel-HCE model possessing the following characteristics of HCE in vivo was formed: six cell layers with specific protein expressions and their barrier function. Time-dependent profiles of TEER values after exposing 30 test chemicals to the HCE model were converted into the scores of three indexes (time lag, intensity, and plateau level), and each chemical was successfully classified into irritant or nonirritant category by utilizing the criteria for the indexes, resulting in the excellent correlation with Globally Harmonized System of Classification and Labelling of Chemicals (GHS) classification (sensitivity: 100%, specificity: 75%, accuracy: 90%). These data suggest that the widespread eye irritancy of chemicals can be predicted without false negatives by the Vitrigel-EIT method. Interestingly, the disruption of tight junctions was immunohistologically observed after exposing not only irritants but also three compounds classified as nonirritant by GHS but found positive in our Vitrigel-EIT method confirming a possible mild irritant property.
-
Molina, Juan Ramón; Moreno, Roberto; Castillo, Miguel; Rodríguez Y Silva, Francisco
2018-04-01
Large fires are the most important disturbances at landscape-level due to their ecological and socioeconomic impacts. This study aimed to develop an approach for the assessment of the socio-economic landscape susceptibility to fire. Our methodology focuses on the integration of economic components of landscape management based on contingent valuation method (CVM) and net-value change (NVC). This former component has been estimated using depreciation rates or changes on the number of arrivals to different natural protected areas after a large fire occurrence. Landscape susceptibility concept has been motivated by the need to assist fire prevention programs and environmental management. There was a remarkable variation in annual economic value attributed to each protected area based on the CVM scenario, ranging from 40,189-46,887$/year ("Tolhuaca National Park") to 241,000-341,953$/year ("Conguillio National Park"). We added landscape susceptibility using depreciation rates or tourist arrival decrease which varied from 2.04% (low fire intensity in "Tolhuaca National Park") to 76.67% (high fire intensity in "Conguillio National Park"). The integration of this approach and future studies about vegetation resilience should seek management strategies to increase economic efficiency in the fire prevention activities. Copyright © 2017 Elsevier B.V. All rights reserved.
-
McKinley, Scott A; Chen, Alex; Shi, Feng; Wang, Simi; Mucha, Peter J; Forest, M Gregory; Lai, Samuel K
2014-01-01
Eliciting broadly neutralizing antibodies (bnAb) in cervicovaginal mucus (CVM) represents a promising "first line of defense" strategy to reduce vaginal HIV transmission. However, it remains unclear what levels of bnAb must be present in CVM to effectively reduce infection. We approached this complex question by modeling the dynamic tally of bnAb coverage on HIV. This analysis introduces a critical, timescale-dependent competition: to protect, bnAb must accumulate at sufficient stoichiometry to neutralize HIV faster than virions penetrate CVM and reach target cells. We developed a model that incorporates concentrations and diffusivities of HIV and bnAb in semen and CVM, kinetic rates for binding (kon) and unbinding (koff) of select bnAb, and physiologically relevant thicknesses of CVM and semen layers. Comprehensive model simulations lead to robust conclusions about neutralization kinetics in CVM. First, due to the limited time virions in semen need to penetrate CVM, substantially greater bnAb concentrations than in vitro estimates must be present in CVM to neutralize HIV. Second, the model predicts that bnAb with more rapid kon, almost independent of koff, should offer greater neutralization potency in vivo. These findings suggest the fastest arriving virions at target cells present the greatest likelihood of infection. It also implies the marked improvements in in vitro neutralization potency of many recently discovered bnAb may not translate to comparable reduction in the bnAb dose needed to confer protection against initial vaginal infections. Our modeling framework offers a valuable tool to gaining quantitative insights into the dynamics of mucosal immunity against HIV and other infectious diseases.
-
Screening for toxic phorbol esters in jerky pet treat products using LC-MS.
Nishshanka, Upul; Jayasuriya, Hiranthi; Chattopadhaya, Chaitali; Kijak, Philip J; Chu, Pak-Sin; Reimschuessel, Renate; Tkachenko, Andriy; Ceric, Olgica; De Alwis, Hemakanthi G
2016-05-01
Since 2007, the U.S. FDA's Center for Veterinary Medicine (CVM) has been investigating reports of pets becoming ill after consuming jerky pet treats. Jerky used in pet treats contains glycerin, which can be made from vegetable oil or as a byproduct of biodiesel production. Because some biodiesel is produced using oil from Jatropha curcas, a plant that contains toxic compounds including phorbol esters, CVM developed a liquid chromatography-mass spectrometry (LC-MS) screening method to evaluate investigational jerky samples for the presence of these toxins. Results indicated that the samples analyzed with the new method did not contain Jatropha toxins at or above the lowest concentration tested. Published by Elsevier B.V.
-
Racial and sex differences in timing of the cervical vertebrae maturation stages.
Montasser, Mona A; Viana, Grace; Evans, Carla A
2017-04-01
Our objective was to investigate skeletal maturation of female and male subjects from different racial groups by comparing the cervical vertebrae maturation (CVM) stages. The study included 3 racial groups: white, African American, and Hispanic subjects. Each group was subdivided into female and male. The age range of the subjects was between 7 and 18 years. The sample included 60 lateral cephalographs for each subgroup. Skeletal maturation of the cervical vertebrae was assessed according to a method that described 6 CVM stages. Racial differences were evident in the mean ages of CVM stages 2, 3, 4, and 5 (P = 0.002; P = 0.003; P = 0.001; and P = 0.001, respectively) among females; among males, only stage 3 was different (P = 0.001). Sex differences in the mean ages of stages 1, 2, and 3 in Hispanic subjects (P <0.001), and in stages 2 and 3 in African American subjects (P = 0.019 and P <0.001) and white subjects (P = 0.004 and P <0.001) were detected. In both sexes, racial differences were not apparent between whites and African Americans, but differences were evident between Hispanics vs both whites and African Americans. Sex differences were apparent between the sexes in each of the 3 ethnic groups in CVM stages 2 and 3. No sex differences were detected in stages 4, 5, or 6 in any of the 3 racial groups. It is recommended to consider racial and sex differences when using the CVM stage as a skeletal maturation indicator. Copyright © 2016 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.
-
Flores-Mir, Carlos; Burgess, Corr A; Champney, Mitchell; Jensen, Robert J; Pitcher, Micheal R; Major, Paul W
2006-01-01
The aim of this study was to assess the correlation between the Fishman maturation prediction method (FMP) and the cervical vertebral maturation (CVM) method for skeletal maturation stage determination. Hand-wrist and lateral cephalograms from 79 subjects (52 females and 27 males) were used. Hand-wrist radiographs were analyzed using the FMP to determine skeletal maturation level (advanced, average, or delayed) and stage (relative position of the individual in the pubertal growth curve). Cervical vertebrae (C2, C3, and C4) outlines obtained from lateral cephalograms were analyzed using the CVM to determine skeletal maturation stage. Intraexaminer reliability (Intraclass correlation coefficient [ICC]) for both methods was calculated from 10 triplicate hand-wrist and lateral cephalograms from the same patients. An ICC coefficient of 0.985 for FMP and an ICC of 0.889 for CVM were obtained. A Spearman correlation value of 0.72 (P < .001) was found between the skeletal maturation stages of both methods. When the sample was subgrouped according to skeletal maturation level, the following correlation values were found: for early mature adolescents 0.73, for average mature adolescents 0.70, and for late mature adolescents 0.87. All these correlation values were statistically different from zero (P < .024). Correlation values between both skeletal maturation methods were moderately high. This may be high enough to use either of the methods indistinctively for research purposes but not for the assessment of individual patients. Skeletal level influences the correlation values and, therefore, it should be considered whenever possible.
-
Zuo, Changyan; Cong, Chao; Wang, Shihui; Gu, Yan
2015-10-01
To compare the difference of corresponding age at cervical vertebral maturation (CVM) stages among different skeletal malocclusions and provide clinic guideline on optimal treatment timing for skeletal malocclusion. Based on ANB angle, 2 575 cephalograms collected from Department of Orthodontics, Peking University School and Hospital of Stomatology from May, 2006 to November, 2014 were classified into skeletal Class I (ANB 0°~5°, 1 317 subjects), Class II (ANB > 5°, 685 subjects) and Class III (ANB < 0°, 573 subjects) groups. CVM stages were evaluated with the modified version of CVM method. Independent sample t test was performed to analyze the difference of age at different CVM stages among various skeletal groups. Significant gender difference of age was found at CS3 to CS6 for skeletal Class I group (P < 0.05), at CS5 and CS6 for skeletal Class II group (P < 0.05), and at CS3 and CS5 for skeletal Class III group (P < 0.05). At CS3 stage, the average age of male in skeletal Class II and skeletal Class III groups was (11.6 ± 1.5) years old and (10.3 ± 1.9) years old, respectively; the average age of females in those two groups was (11.7 ± 1.3) years old and (9.3 ± 1.5) years old, respectively, and significant difference was found in both comparisons (P < 0.05). Compared average age at CS5 and CS6 between skeletal Class II and skeletal Class III groups [the ages of male was (15.1 ± 1.7) and (16.8 ± 1.6) years old, the ages of male was (14.6 ± 1.2) and (15.7 ± 2.5) years old], significant difference was also found (P < 0.05). Significant gender differences were found when evaluated CVM stage and age in skeletal Class I, II and III groups. Significant differences of age at different CVM stage was noted when skeletal Class II was compared with skeletal Class III groups.
-
Evaluation of CBS 600 carburized steel as a gear material
NASA Technical Reports Server (NTRS)
Townsend, D. P.; Parker, R. J.; Zaretsky, E. V.
1979-01-01
Gear endurance tests were conducted with one lot of consumable-electrode vacuum-melted (CVM) AISI 9310 gears and one lot of air-melt CBS 600 gears. The gears were 8 pitch with a pitch diameter of 8.89 centimeters (3.5 in.). Bench-type rolling-element fatigue tests were also conducted with one lot of CVM AISI 9310, three lots of CVM CBS 600, and one of air-melt CBS 600 material. The rolling-element bars were 0.952 centimeter (0.375 in.) in diameter. The CBS 600 material exhibited pitting fatigue lives in both rolling-element specimens and gears at least equivalent to that of CVM AISI 9310. Tooth fracture failure occurred with the CBS 600 gears after overrunning a fatigue spall, but it did not occur with the CVM AISI 9310 gears. Tooth fracture in the CBS 600 was attributed to excessive carbon content in the case, excessive case depth, and a higher than normal core hardness.
-
Demirturk Kocasarac, Husniye; Altan, Ayse Burcu; Yerlikaya, Canan; Sinanoglu, Alper; Noujeim, Marcel
2017-03-01
To assess the correlation between third molar mineralization (TMM), spheno-occipital synchondrosis (SOS) fusion, chronologic age and cervical vertebrae maturation (CVM) for skeletal maturation. Radiographs for 116 patients between 8 and 28 years were evaluated for age determination using mandibular TMM, SOS fusion and CVM. Spearman Correlation and Kappa test analyses were used to assess the relationship between variables and for intraobserver reliability. Strong correlation was found between chronological age and TMM for males (r = .802) and females (r = .842), very strong correlation was found between age and CVM for males (r = .812) and moderate for females (r = .449), it was strong between age and SOS fusion for males (r = .810) and females (r = .643). Correlation between TMM and SOS was found to be strong for males (r = .759) and moderate for females (r = .534), it was strong between TMM and CVM for males (r = .723) and weak for females (r = .371). Very strong correlation was found between CVM and SOS fusion for males (r = .851) and strong correlation for females (r = .618). Good correlation was found between the degrees of TMM, fusion of SOS and CVM in young Turkish population.
-
The cervical vertebral maturation method: A user's guide.
McNamara, James A; Franchi, Lorenzo
2018-03-01
The cervical vertebral maturation (CVM) method is used to determine the craniofacial skeletal maturational stage of an individual at a specific time point during the growth process. This diagnostic approach uses data derived from the second (C2), third (C3), and fourth (C4) cervical vertebrae, as visualized in a two-dimensional lateral cephalogram. Six maturational stages of those three cervical vertebrae can be determined, based on the morphology of their bodies. The first step is to evaluate the inferior border of these vertebral bodies, determining whether they are flat or concave (ie, presence of a visible notch). The second step in the analysis is to evaluate the shape of C3 and C4. These vertebral bodies change in shape in a typical sequence, progressing from trapezoidal to rectangular horizontal, to square, and to rectangular vertical. Typically, cervical stages (CSs) 1 and CS 2 are considered prepubertal, CS 3 and CS 4 circumpubertal, and CS 5 and CS 6 postpubertal. Criticism has been rendered as to the reproducibility of the CVM method. Diminished reliability may be observed at least in part due to the lack of a definitive description of the staging procedure in the literature. Based on the now nearly 20 years of experience in staging cervical vertebrae, this article was prepared as a "user's guide" that describes the CVM stages in detail in attempt to help the reader use this approach in everyday clinical practice.
-
Clinical, Genetic and Environmental Factors Associated with Congenital Vertebral Malformations
Giampietro, P.F.; Raggio, C.L.; Blank, R.D.; McCarty, C.; Broeckel, U.; Pickart, M.A.
2013-01-01
Congenital vertebral malformations (CVM) pose a significant health problem because they can be associated with spinal deformities, such as congenital scoliosis and kyphosis, in addition to various syndromes and other congenital malformations. Additional information remains to be learned regarding the natural history of congenital scoliosis and related health problems. Although significant progress has been made in understanding the process of somite formation, which gives rise to vertebral bodies, there is a wide gap in our understanding of how genetic factors contribute to CVM development. Maternal diabetes during pregnancy most commonly contributes to the occurrence of CVM, followed by other factors such as hypoxia and anticonvulsant medications. This review highlights several emerging clinical issues related to CVM, including pulmonary and orthopedic outcome in congenital scoliosis. Recent breakthroughs in genetics related to gene and environment interactions associated with CVM development are discussed. The Klippel-Feil syndrome which is associated with cervical segmentation abnormalities is illustrated as an example in which animal models, such as the zebrafish, can be utilized to provide functional evidence of pathogenicity of identified mutations. PMID:23653580
-
Diagnostic performance of skeletal maturity for the assessment of midpalatal suture maturation.
Angelieri, Fernanda; Franchi, Lorenzo; Cevidanes, Lucia H S; McNamara, James A
2015-12-01
The aim of this study was to analyze the diagnostic performance of the cervical vertebral maturation (CVM) method in estimating accurately the stages of maturation of the midpalatal suture. Cone-beam computed tomography (CBCT) images from 142 subjects (84 female, 58 male; mean age, 14.8 ± 9.7 years) were analyzed by 2 calibrated examiners to define, by visual analysis, the maturational stages of the cervical vertebrae and the midpalatal suture. These CBCT images were required by orthodontists and surgeons for diagnosis and treatment purposes. Positive likelihood ratios (LHRs) were calculated to evaluate the diagnostic performance of the CVM stages in identifying the maturational stages of the midpalatal suture. Positive LHRs greater than 10 were found for several cervical vertebral stages (CSs), including CS1 and CS2 for the identification of midpalatal suture stages A and B, CS3 for the diagnosis of midpalatal suture stage C, and CS5 for the assessment of midpalatal suture stages D and E. These positive LHRs indicated large and often conclusive increases in the likelihood that the CVM stages were associated with specific stages of midpalatal suture maturation. At CS4, there were a moderate positive LHR for stage C and low positive LHRs for stages D and E. Most CVM stages can be used for the diagnosis of the stages of maturation of the midpalatal suture, so that CBCT imaging may not be necessary in these patients. In the postpubertal period, however, an assessment of the midpalatal suture maturation using CBCT images may be indicated in deciding between conventional rapid maxillary expansion and surgically assisted rapid maxillary expansion. On the other hand, if the CVM stage cannot be assessed, chronologic age may be a viable alternative to predict some midpalatal suture stages (particularly the early stages). Copyright © 2015 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.
-
Perinetti, G; Perillo, L; Franchi, L; Di Lenarda, R; Contardo, L
2014-11-01
Diagnostic agreement on individual basis between the third middle phalanx maturation (MPM) method and the cervical vertebral maturation (CVM) method has conjecturally been based mainly on overall correlation analyses. Herein, the true agreement between methods according to stage and sex has been evaluated through a comprehensive diagnostic performance analysis. Four hundred and fifty-one Caucasian subjects were included in the study, 231 females and 220 males (mean age, 12.2 ± 2.5 years; range, 7.0-17.9 years). The X-rays of the middle phalanx of the third finger and the lateral cephalograms were examined for staging by blinded operators, blinded for MPM stages and subjects' age. The MPM and CVM methods based on six stages, two pre-pubertal (1 and 2), two pubertal (3 and 4), and two post-pubertal (5 and 6), were considered. Specifically, for each MPM stage, the diagnostic performance in the identification of the corresponding CVM stage was described by Bayesian statistics. For both sexes, overall agreement was 77.6%. Most of the disagreement was due to 1 stage apart. Slight disagreement was seen for the stages 5 and 6, where the third middle phalanx shows an earlier maturation. The two maturational methods show an overall satisfactorily diagnostic agreement. However, at post-pubertal stages, the middle phalanx of the third finger appears to mature earlier than the cervical vertebrae. Post-pubertal growth phase should thus be based on the presence of stage 6 in MPM. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
-
Determining skeletal maturation using insulin-like growth factor I (IGF-I) test.
Gupta, Shreya; Jain, Sandhya; Gupta, Puneet; Deoskar, Anuradha
2012-11-01
To investigate the validity of Insulin like Growth Factor -1(IGF-1) as a skeletal maturity indicator by comparing serum IGF-1 levels with the stages in cervical vertebral maturation (CVM) and in the middle phalanx of the third finger (MP3). The study population was selected by using simple random sampling technique and consisted of 30 female subjects in the age range of 8-23 years who had blood sample, cephalometric and MP3 radiographs taken on the same day. Serum IGF-I estimation was carried out on the blood samples using chemiluminescence immunoassay (CLIA) method. CVM was evaluated using method by Baccetti et al and MP3 staging was done using Rajagopal & Kansal method. Mean IGF-1 level between the stages was compared by Kruskal-Wallis and Mann Whitney test. Serum IGF-1 levels in females correlate well with skeletal maturity determined by CVM and MP3 stages and increase sharply during early pubertal stages followed by a decrease in late puberty. In addition we hypothesis that serum IGF-1 testing can be undertaken as a preliminary screening test in patients in whom the orthodontist predicts the possibility of using myofunctional appliance but in whom the chronologic age is not suggestive for a growth modification therapy. The finding of the study highlights the fact that the serum IGF-1 estimation can be a valuable tool in assessing skeletal maturation. Copyright © 2012 Società Italiana di Ortodonzia SIDO. Published by Elsevier Srl. All rights reserved.
-
NASA Astrophysics Data System (ADS)
Loomis, John; McTernan, James
2014-03-01
Whitewater river kayaking and river rafting require adequate instream flows that are often adversely affected by upstream water diversions. However, there are very few studies in the USA of the economic value of instream flow to inform environmental managers. This study estimates the economic value of instream flow to non-commercial kayakers derived using a Travel Cost Method recreation demand model and Contingent Valuation Method (CVM), a type of Contingent Behavior Method (CBM). Data were obtained from a visitor survey administered along the Poudre River in Colorado. In the dichotomous choice CVM willingness to pay (WTP) question, visitors were asked if they would still visit the river if the cost of their trip was Y higher, and the level of Y was varied across the sample. The CVM yielded an estimate of WTP that was sensitive to flows ranging from 55 per person per day at 300 Cubic Feet per Second (CFS) to a maximum 97 per person per day at flows of 1900 CFS. The recreation demand model estimated a boater's number of trips per season. We found the number of trips taken was also sensitive to flow, ranging from as little as 1.63 trips at 300 CFS to a maximum number of 14 trips over the season at 1900 CFS. Thus, there is consistency between peak benefits per trip and number of trips, respectively. With an average of about 100 non-commercial boaters per day, the maximum marginal values per acre foot averages about 220. This value exceeds irrigation water values in this area of Colorado.
-
Paiva, D S; Fonseca, I; Pinto, I S B; Ianella, P; Campos, T A; Caetano, A R; Paiva, S R; Silva, M V G B; Martins, M F
2013-08-29
Among the various hereditary diseases that have been widely studied in dairy cattle, bovine leukocyte adhesion deficiency (BLAD), deficiency of uridine-5-monophosphate synthase (DUMPS), and complex vertebral malformation (CVM) are noteworthy because of their high impact on overall herd productivity as a consequence of increased calf mortality. The aim of this study was to verify the frequency of carriers of BLAD, CVM, and DUMPS mutant alleles in cows and bulls from the National Girolando Progeny Test carried out in Brazil by using polymerase chain reaction (PCR)-restriction fragment length polymorphism and allele-specific PCR assays. A total of 777 animals were genotyped for BLAD, 783 for CVM, and 122 for DUMPS. The frequencies of carriers for BLAD and CVM were 0.77 and 1.53%, respectively, whereas no carriers of DUMPS were observed.
-
An unbalanced spectra classification method based on entropy
NASA Astrophysics Data System (ADS)
Liu, Zhong-bao; Zhao, Wen-juan
2017-05-01
How to solve the problem of distinguishing the minority spectra from the majority of the spectra is quite important in astronomy. In view of this, an unbalanced spectra classification method based on entropy (USCM) is proposed in this paper to deal with the unbalanced spectra classification problem. USCM greatly improves the performances of the traditional classifiers on distinguishing the minority spectra as it takes the data distribution into consideration in the process of classification. However, its time complexity is exponential with the training size, and therefore, it can only deal with the problem of small- and medium-scale classification. How to solve the large-scale classification problem is quite important to USCM. It can be easily obtained by mathematical computation that the dual form of USCM is equivalent to the minimum enclosing ball (MEB), and core vector machine (CVM) is introduced, USCM based on CVM is proposed to deal with the large-scale classification problem. Several comparative experiments on the 4 subclasses of K-type spectra, 3 subclasses of F-type spectra and 3 subclasses of G-type spectra from Sloan Digital Sky Survey (SDSS) verify USCM and USCM based on CVM perform better than kNN (k nearest neighbor) and SVM (support vector machine) in dealing with the problem of rare spectra mining respectively on the small- and medium-scale datasets and the large-scale datasets.
-
Karnasuta, Chitraporn; Vasan, Sandhya; Rerks-Ngarm, Supachai; Pitisuttithum, Punnee; Madnote, Sirinan; Savadsuk, Hathairat; Rittiroongrad, Surawach; Puangkaew, Jiraporn; Phogat, Sanjay; Tartaglia, James; Sinangil, Faruk; de Souza, Mark S.; Excler, Jean-Louis; Kim, Jerome H.; Robb, Merlin L.; Michael, Nelson L.; Ngauy, Viseth; O'Connell, Robert J.; Karasavvas, Nicos
2018-01-01
Sexual transmission is the principal driver of the human immunodeficiency virus (HIV) pandemic. Understanding HIV vaccine-induced immune responses at mucosal surfaces can generate hypotheses regarding mechanisms of protection, and may influence vaccine development. The RV144 (ClinicalTrials.gov NCT00223080) efficacy trial showed protection against HIV infections but mucosal samples were not collected, therefore, the contribution of mucosal antibodies to preventing HIV-1 acquisition is unknown. Here, we report the generation, magnitude and persistence of antibody responses to recombinant gp120 envelope and antigens including variable one and two loop scaffold antigens (gp70V1V2) previously shown to correlate with risk in RV144. We evaluated antibody responses to gp120 A244gD and gp70V1V2 92TH023 (both CRF01_AE) and Case A2 (subtype B) in cervico-vaginal mucus (CVM), seminal plasma (SP) and rectal secretions (RS) from HIV-uninfected RV144 vaccine recipients, who were randomized to receive two late boosts of ALVAC-HIV/AIDSVAX®B/E, AIDSVAX®B/E, or ALVAC-HIV alone at 0 and 6 months. Late vaccine boosting increased IgG geometric mean titers (GMT) to gp120 A244gD in AIDSVAX®B/E and ALVAC-HIV/AIDSVAX®B/E CVM (28 and 17 fold, respectively), followed by SP and RS. IgG to gp70V1V2 92TH023 increased in AIDSVAX®B/E and ALVAC-HIV/AIDSVAX®B/E CVM (11–17 fold) and SP (2 fold) two weeks post first boost. IgG to Case A2 was only detected in AIDSVAX®B/E and ALVAC-HIV/AIDSVAX®B/E CVM. Mucosal IgG to gp120 A244gD (CVM, SP, RS), gp70V1V2 92TH023 (CVM, SP), and Case A2 (CVM) correlated with plasma IgG levels (p<0.001). Although the magnitude of IgG responses declined after boosting, anti-gp120 A244gD IgG responses in CVM persisted for 12 months post final vaccination. Further studies in localization, persistence and magnitude of envelope specific antibodies (IgG and dimeric IgA) in anogenital secretions will help determine their role in preventing mucosal HIV acquisition. PMID:29702672
-
Spheno-Occipital Synchondrosis Fusion Correlates with Cervical Vertebrae Maturation.
Fernández-Pérez, María José; Alarcón, José Antonio; McNamara, James A; Velasco-Torres, Miguel; Benavides, Erika; Galindo-Moreno, Pablo; Catena, Andrés
2016-01-01
The aim of this study was to determine the relationship between the closure stage of the spheno-occipital synchondrosis and the maturational stage of the cervical vertebrae (CVM) in growing and young adult subjects using cone beam computed tomography (CBCT). CBCT images with an extended field of view obtained from 315 participants (148 females and 167 males; mean age 15.6 ±7.3 years; range 6 to 23 years) were analyzed. The fusion status of the synchondrosis was determined using a five-stage scoring system; the vertebral maturational status was evaluated using a six-stage stratification (CVM method). Ordinal regression was used to study the ability of the synchondrosis stage to predict the vertebral maturation stage. Vertebrae and synchondrosis had a strong significant correlation (r = 0.89) that essential was similar for females (r = 0.88) and males (r = 0.89). CVM stage could be accurately predicted from synchondrosis stage by ordinal regression models. Prediction equations of the vertebral stage using synchondrosis stage, sex and biological age as predictors were developed. Thus this investigation demonstrated that the stage of spheno-occipital synchondrosis, as determined in CBCT images, is a reasonable indicator of growth maturation.
-
Spheno-Occipital Synchondrosis Fusion Correlates with Cervical Vertebrae Maturation
Fernández-Pérez, María José; McNamara, James A.; Velasco-Torres, Miguel; Benavides, Erika; Galindo-Moreno, Pablo; Catena, Andrés
2016-01-01
The aim of this study was to determine the relationship between the closure stage of the spheno-occipital synchondrosis and the maturational stage of the cervical vertebrae (CVM) in growing and young adult subjects using cone beam computed tomography (CBCT). CBCT images with an extended field of view obtained from 315 participants (148 females and 167 males; mean age 15.6 ±7.3 years; range 6 to 23 years) were analyzed. The fusion status of the synchondrosis was determined using a five-stage scoring system; the vertebral maturational status was evaluated using a six-stage stratification (CVM method). Ordinal regression was used to study the ability of the synchondrosis stage to predict the vertebral maturation stage. Vertebrae and synchondrosis had a strong significant correlation (r = 0.89) that essential was similar for females (r = 0.88) and males (r = 0.89). CVM stage could be accurately predicted from synchondrosis stage by ordinal regression models. Prediction equations of the vertebral stage using synchondrosis stage, sex and biological age as predictors were developed. Thus this investigation demonstrated that the stage of spheno-occipital synchondrosis, as determined in CBCT images, is a reasonable indicator of growth maturation. PMID:27513752
-
Rosso, Luigi; Riatti, Riccardo
2016-01-01
The knowledge of the associations between the timing of skeletal maturation and craniofacial growth is of primary importance when planning a functional treatment for most of the skeletal malocclusions. This cross-sectional study was thus aimed at evaluating whether sagittal and vertical craniofacial growth has an association with the timing of circumpubertal skeletal maturation. A total of 320 subjects (160 females and 160 males) were included in the study (mean age, 12.3 ± 1.7 years; range, 7.6–16.7 years). These subjects were equally distributed in the circumpubertal cervical vertebral maturation (CVM) stages 2 to 5. Each CVM stage group also had equal number of females and males. Multiple regression models were run for each CVM stage group to assess the significance of the association of cephalometric parameters (ANB, SN/MP, and NSBa angles) with age of attainment of the corresponding CVM stage (in months). Significant associations were seen only for stage 3, where the SN/MP angle was negatively associated with age (β coefficient, −0.7). These results show that hyperdivergent and hypodivergent subjects may have an anticipated and delayed attainment of the pubertal CVM stage 3, respectively. However, such association remains of little entity and it would become clinically relevant only in extreme cases. PMID:27995136
-
Perinetti, Giuseppe; Rosso, Luigi; Riatti, Riccardo; Contardo, Luca
2016-01-01
The knowledge of the associations between the timing of skeletal maturation and craniofacial growth is of primary importance when planning a functional treatment for most of the skeletal malocclusions. This cross-sectional study was thus aimed at evaluating whether sagittal and vertical craniofacial growth has an association with the timing of circumpubertal skeletal maturation. A total of 320 subjects (160 females and 160 males) were included in the study (mean age, 12.3 ± 1.7 years; range, 7.6-16.7 years). These subjects were equally distributed in the circumpubertal cervical vertebral maturation (CVM) stages 2 to 5. Each CVM stage group also had equal number of females and males. Multiple regression models were run for each CVM stage group to assess the significance of the association of cephalometric parameters (ANB, SN/MP, and NSBa angles) with age of attainment of the corresponding CVM stage (in months). Significant associations were seen only for stage 3, where the SN/MP angle was negatively associated with age (β coefficient, -0.7). These results show that hyperdivergent and hypodivergent subjects may have an anticipated and delayed attainment of the pubertal CVM stage 3, respectively. However, such association remains of little entity and it would become clinically relevant only in extreme cases.
-
Evaluation of efficacy of heartworm preventive products at the FDA.
Hampshire, Victoria A
2005-10-24
The Center for Veterinary Medicine, U.S. Food and Drug Administration (FDA/CVM) has authority under the United States Code 21 under Section 514.80 to monitor for adverse experiences of approved animal products. Although veterinarians voluntarily report suspect drug-related events to manufacturers, firms that market FDA-approved animal products must report serious events to the FDA within 15 working days of the veterinarian or pet-owner's call to them. Under the present regulations, canine heartworm preventatives are approved for 100% efficacy after testing in laboratory and field conditions. The report of lack of efficacy against heartworm larvae is a serious adverse drug event because the resulting condition or the treatment of the condition is life threatening. Information on lack of effect that are deemed possibly, probably, or definitely drug-related available for review under generic product on the FDA/CVM website Surveillance of these reports indicates there are some failures for virtually all heartworm prevention product categories. Most failures have been reported in heartworm-endemic states. At this time, it is unclear whether these are representative of the rare occurrences of failure that have been in existence for a long time, but not reported regularly or promptly, or whether there is a true increase in complaints of ineffectiveness and real variability between products. This paper discusses methods, personnel, and procedures in place in the Division of Surveillance that will aid the FDA to better assess heartworm preventive treatment failures. It discusses scoring paradigms presently utilized by FDA/CVM to assess severity of complaints of lack of efficacy against heartworms, and welcomes audience input as to how to improve existing processes. Results suggest that more comprehensive reporting will provide FDA/CVM more accurate surveillance information regarding efficacy problems. Such practices will permit FDA/CVM to better interpret both incidence and severity of in-effect and possible patterns of emerging resistance and to convey this in any necessary updated labeling. It also indicates that as part of that process, practitioners should return to a more conservative testing schedule.
-
Inflammatory responses and side effects generated by several adjuvant-containing vaccines in turbot.
Noia, M; Domínguez, B; Leiro, J; Blanco-Méndez, J; Luzardo-Álvarez, A; Lamas, J
2014-05-01
Several of the adjuvants used in fish vaccines cause adhesions in internal organs when they are injected intraperitoneally. We describe the damage caused by vaccines containing different adjuvants in the turbot Scophthalmus maximus and show that internal adhesions can be greatly reduced by injecting the fish in a specific way. Injection of fish with the needle directed towards the anterior part of the peritoneal cavity induced formation of a single cell-vaccine mass (CVM) that became attached to the parietal peritoneum. However, injection of the fish with the needle pointing in the opposite direction generated many small CVM that became attached to the visceral and parietal peritoneum and in some cases caused internal adhesions. We describe the structural and cellular changes in the adjuvant-induced CVMs. The CVMs mainly comprised neutrophils and macrophages, although most of the former underwent apoptosis, which was particularly evident from day 3 post-injection. The apoptotic cells were phagocytosed by macrophages, which were the dominant cell type from the first days onwards. All of the vaccines induced angiogenesis in the area of contact between the CVM and the mesothelium. Vaccines containing oil-based adjuvants or microspheres induced the formation of granulomas in the CVM; however, no granulomas were observed in the CVM induced by vaccines containing aluminium hydroxide or Matrix-Q(®) as adjuvants. All of the vaccines induced strong migration of cells to the peritoneal cavity. Although some of these cells remained unattached in the peritoneal cavity, most of them formed part of the CVM. We also observed migration of the cells from the peritoneal cavity to lymphoid organs, indicating bidirectional traffic of cells between the inflamed areas and these organs. Copyright © 2014 Elsevier Ltd. All rights reserved.
-
Regmi, Prajwal R; Shaw, Ashley L; Hungerford, Laura L; Messenheimer, Janis R; Zhou, Tong; Pillai, Padmakumar; Omer, Amy; Gilbert, Jeffrey M
2016-12-01
Histomoniasis, commonly referred to as blackhead disease, is a serious threat to the turkey and game bird industries worldwide, and it is having an increasingly negative impact on the chicken industry as well. The Food and Drug Administration's (FDA) Center for Veterinary Medicine (CVM), charged with the approval and regulation of new animal drugs in the United States, understands the rising need for the availability of therapeutic options against histomoniasis. CVM has actively engaged in discussions with the poultry industry, academic institutions, and animal health companies regarding the current status of histomoniasis in the United States and varied success of past and current management, prophylactic, and therapeutic interventions that have been used against the disease. As effective options against the disease are severely limited, CVM encourages the poultry industry, academic institutions, and animal health companies to work together to research and develop viable management, prophylactic, and therapeutic strategies, such as litter management, deworming programs, vaccines or other biologics, novel technologies, and animal drugs. CVM also recognizes the potential challenges that the poultry industry, academic institutions, and animal health companies may encounter while working towards the approval of safe and effective drug products for the treatment and control of histomoniasis. With that recognition, CVM encourages interested parties to begin discussions with CVM early in order to align research of the drug product against histomoniasis with the drug approval requirements, such that it leads to the approval of a new animal drug in an efficient and expedient manner. This article provides information about the FDA's regulatory process for the approval of new animal drugs in the United States, with especial emphasis on drug products for the treatment and control of histomoniasis in turkeys, chickens, and game birds.
-
Using S3 cloud storage with ROOT and CvmFS
NASA Astrophysics Data System (ADS)
Arsuaga-Ríos, María; Heikkilä, Seppo S.; Duellmann, Dirk; Meusel, René; Blomer, Jakob; Couturier, Ben
2015-12-01
Amazon S3 is a widely adopted web API for scalable cloud storage that could also fulfill storage requirements of the high-energy physics community. CERN has been evaluating this option using some key HEP applications such as ROOT and the CernVM filesystem (CvmFS) with S3 back-ends. In this contribution we present an evaluation of two versions of the Huawei UDS storage system stressed with a large number of clients executing HEP software applications. The performance of concurrently storing individual objects is presented alongside with more complex data access patterns as produced by the ROOT data analysis framework. Both Huawei UDS generations show a successful scalability by supporting multiple byte-range requests in contrast with Amazon S3 or Ceph which do not support these commonly used HEP operations. We further report the S3 integration with recent CvmFS versions and summarize the experience with CvmFS/S3 for publishing daily releases of the full LHCb experiment software stack.
-
Chen, Hong-Guang; Wang, Qiu-Dan; Li, Chen-Yang
2014-09-01
Contingent valuation method (CVM) is the most widespread method to assess resources and value of environmental goods and services. The guidance technology of willingness to pay (WTP) is an important means of CVM. Therefore, the study on the WTP guidance technology is an important approach to improve the reliability and validity of CVM. This article conducted comprehensive evaluation on non-use value of eco-tourism water resources in Sanjiang Plain by using payment card, single-bound dichotomous choice and double-bound dichotomous choice. Results showed that the socio-economic attributes were consistent with the willingness to pay in the three formats, and the tender value, age, educational level, annual income and the concern level had significant effect on the willingness to pay, while gender and job did not have significant influence. The WTP value was 112.46 yuan per capita with the payment card, 136.15 with the single-bound dichotomous choice, and 168.74 with the double-bound dichotomous choice. Comprehensive consideration of the nature of the investigation, investigation costs and statistical techniques, the result of double-bound dichotomous choice (47.86 x 10(8) yuan · a(-1)) was best in accordance with the reality, and could be used as non-use value of eco-tourism water resources in Sanjiang Plain. The format of questionnaire was very important to improve its validity, and made a great influence on the WTP.
-
Eden, Martin; Payne, Katherine; Combs, Ryan M; Hall, Georgina; McAllister, Marion; Black, Graeme C M
2013-08-01
Technological advances present an opportunity for more people with, or at risk of, developing retinitis pigmentosa (RP) to be offered genetic testing. Valuation of these tests using current evaluative frameworks is problematic since benefits may be derived from diagnostic information rather than improvements in health. This pilot study aimed to explore if contingent valuation method (CVM) can be used to value the benefits of genetic testing for RP. CVM was used to elicit willingness-to-pay (WTP) values for (1) genetic counselling and (2) genetic counselling with genetic testing. Telephone and face-to-face interviews with a purposive sample of individuals with (n=25), and without (n=27), prior experience of RP were used to explore the feasibility and validity of CVM in this context. Faced with a hypothetical scenario, the majority of participants stated that they would seek genetic counselling and testing in the context of RP. Between participant groups, respondents offered similar justifications for stated WTP values. Overall stated WTP was higher for genetic counselling plus testing (median=£524.00) compared with counselling alone (median=£224.50). Between-group differences in stated WTP were statistically significant; participants with prior knowledge of the condition were willing to pay more for genetic ophthalmology services. Participants were able to attach a monetary value to the perceived potential benefit that genetic testing offered regardless of prior experience of the condition. This exploratory work represents an important step towards evaluating these services using formal cost-benefit analysis.
-
A Vs30-derived Near-surface Seismic Velocity Model
NASA Astrophysics Data System (ADS)
Ely, G. P.; Jordan, T. H.; Small, P.; Maechling, P. J.
2010-12-01
Shallow material properties, S-wave velocity in particular, strongly influence ground motions, so must be accurately characterized for ground-motion simulations. Available near-surface velocity information generally exceeds that which is accommodated by crustal velocity models, such as current versions of the SCEC Community Velocity Model (CVM-S4) or the Harvard model (CVM-H6). The elevation-referenced CVM-H voxel model introduces rasterization artifacts in the near-surface due to course sample spacing, and sample depth dependence on local topographic elevation. To address these issues, we propose a method to supplement crustal velocity models, in the upper few hundred meters, with a model derived from available maps of Vs30 (the average S-wave velocity down to 30 meters). The method is universally applicable to regions without direct measures of Vs30 by using Vs30 estimates from topographic slope (Wald, et al. 2007). In our current implementation for Southern California, the geology-based Vs30 map of Wills and Clahan (2006) is used within California, and topography-estimated Vs30 is used outside of California. Various formulations for S-wave velocity depth dependence, such as linear spline and polynomial interpolation, are evaluated against the following priorities: (a) capability to represent a wide range of soil and rock velocity profile types; (b) smooth transition to the crustal velocity model; (c) ability to reasonably handle poor spatial correlation of Vs30 and crustal velocity data; (d) simplicity and minimal parameterization; and (e) computational efficiency. The favored model includes cubic and square-root depth dependence, with the model extending to a depth of 350 meters. Model parameters are fit to Boore and Joyner's (1997) generic rock profile as well as CVM-4 soil profiles for the NEHRP soil classification types. P-wave velocity and density are derived from S-wave velocity by the scaling laws of Brocher (2005). Preliminary assessment of the new model is preformed with ground motion simulations for a selection of likely M > 7 scenario events for Southern California (as define by the SCEC Big Ten project).
-
Graves, Robert W.; Aagaard, Brad T.
2011-01-01
Using a suite of five hypothetical finite-fault rupture models, we test the ability of long-period (T>2.0 s) ground-motion simulations of scenario earthquakes to produce waveforms throughout southern California consistent with those recorded during the 4 April 2010 Mw 7.2 El Mayor-Cucapah earthquake. The hypothetical ruptures are generated using the methodology proposed by Graves and Pitarka (2010) and require, as inputs, only a general description of the fault location and geometry, event magnitude, and hypocenter, as would be done for a scenario event. For each rupture model, two Southern California Earthquake Center three-dimensional community seismic velocity models (CVM-4m and CVM-H62) are used, resulting in a total of 10 ground-motion simulations, which we compare with recorded ground motions. While the details of the motions vary across the simulations, the median levels match the observed peak ground velocities reasonably well, with the standard deviation of the residuals generally within 50% of the median. Simulations with the CVM-4m model yield somewhat lower variance than those with the CVM-H62 model. Both models tend to overpredict motions in the San Diego region and underpredict motions in the Mojave desert. Within the greater Los Angeles basin, the CVM-4m model generally matches the level of observed motions, whereas the CVM-H62 model tends to overpredict the motions, particularly in the southern portion of the basin. The variance in the peak velocity residuals is lowest for a rupture that has significant shallow slip (<5 km depth), whereas the variance in the residuals is greatest for ruptures with large asperities below 10 km depth. Overall, these results are encouraging and provide confidence in the predictive capabilities of the simulation methodology, while also suggesting some regions in which the seismic velocity models may need improvement.
-
Economic amenity values of wildlife: Six case studies in Pennsylvania
NASA Astrophysics Data System (ADS)
Shafer, Elwood L.; Carline, Robert; Guldin, Richard W.; Cordell, H. Ken
1993-09-01
The travel clost method (TCM) and contingent valuation method (CVM) were used to evaluate the economic value of six different ecotourism activities involving observation of wildlife in Pennsylvania. The six activities were: catch-and-release trout fishing; catch-and-release trout fishing with fly-fishing equipment; viewing waterfowl; watching elk; observing migration flights of raptors; and seeing live wildlife in an environmental education setting. TCM results provided significant statistical relationships between level of use and travel costs for the two types of trout fishing activities. CVM provided estimates of consumer surplus for the other four sites. The consumers' surplus value (1988 dollars) of all six activities to participants amounted to a total of more than 1.28 million annually—twice the total out-of-pocket expenditures of approximately 640,000 spent to visit the sites. The economic amenity values of the six activities compare favorably with similarly derived values in other studies for hunting, fishing, hiking, and backpacking in dispersed recreation environments and wilderness areas in western states.
-
Draft genome sequences of Streptococcus bovis strains ATCC 33317 and JB1
USDA-ARS?s Scientific Manuscript database
We report the draft genome sequences of Streptococcus bovis type strain ATTC 33317 (CVM42251) isolated from cow dung and strain JB1 (CVM42252) isolated from a cow rumen in 1977. Strains were subjected to Next Generation sequencing and the genome sizes are approximately 2 MB and 2.2 MB, respectively....
-
Różyło-Kalinowska, Ingrid; Kolasa--Rączka, Anna; Kalinowski, Paweł
2011-02-01
The purpose of the study was to investigate the relationship between Demirjian's method and the improved cervical vertebrae maturation (CVM) method. The material consisted of the clinical files and panoramic and lateral cephalometric radiographs of 718 children (431 girls and 287 boys) aged from 6 to 17 years, inhabitants of the Mazovia region (Central Poland). Dental age according to Demirjian was estimated using panoramic radiographs and the cervical stages (CS) of the CVM were evaluated on cephalometric radiographs. Descriptive statistics of the chronological and dental ages of the patients for a particular CS of skeletal maturity was calculated for girls and boys separately. Linear regression analysis and correlation (Pearson's r coefficient), as well as the Spearman rank correlation coefficient (R) were applied to measure the association between CS and dental calcification stages of all analysed teeth. A consistently earlier occurrence (by about 6 months) for each CS was observed in females. A moderate, but statistically significant, correlation between Demirjian's dental developmental stages and CS was determined. The level of the correlation was different for individual teeth: the teeth showing the highest relationship with CVM were the second premolars and canines (in female and male subjects, respectively). The central incisor demonstrated the poorest correlation in both genders. The findings confirmed that both dental and skeletal maturity should be assessed if the maturity stage of a growing child is to be relevant to clinical practice. The results indicate the usefulness of dental calcification stages as a simple first-level diagnostic test to determine the skeletal maturity status of a subject.
-
Estimating residents' willingness to pay for groundwater protection in the Vietnamese Mekong Delta
NASA Astrophysics Data System (ADS)
Vo, Danh Thanh; Huynh, Khai Viet
2017-03-01
Groundwater in the Vietnamese Mekong Delta is facing the pollution and it needs to be protected. Searching literature reviews on economic valuation techniques, the contingent valuation method (CVM) has been popularly applied to estimate the economic value of water protection. This approach is based on a hypothetical scenario in which respondents are requested through questionnaires to reveal their maximum willingness to pay (WTP) for the water protection project. The study used the approach of CVM to analyze the households' motivations and their WTP for the program of groundwater protection in the Mekong Delta. The study performed that the residents in the delta were willing to pay approximately 141,730 VND (US6.74) per household a year. Groundwater could be an inferior good with the negative income effect found in the demanding for clean groundwater. Respondent's gender and groundwater-related health risk consideration were factors sensitively affecting the probability of demanding for groundwater protection.
-
TeleOperator/telePresence System (TOPS) Concept Verification Model (CVM) development
NASA Technical Reports Server (NTRS)
Shimamoto, Mike S.
1993-01-01
The development of an anthropomorphic, undersea manipulator system, the TeleOperator/telePresence System (TOPS) Concept Verification Model (CVM) is described. The TOPS system's design philosophy, which results from NRaD's experience in undersea vehicles and manipulator systems development and operations, is presented. The TOPS design approach, task teams, manipulator, and vision system development and results, conclusions, and recommendations are presented.
-
ERIC Educational Resources Information Center
Mechling, Linda C.; Ayres, Kevin M.; Bryant, Kathryn J.; Foster, Ashley L.
2014-01-01
The current study evaluated a relatively new video-based procedure, continuous video modeling (CVM), to teach multi-step cleaning tasks to high school students with moderate intellectual disability. CVM in contrast to video modeling and video prompting allows repetition of the video model (looping) as many times as needed while the user completes…
-
Cao, Guojie; Allard, Marc; Hoffmann, Maria; Muruvanda, Tim; Luo, Yan; Payne, Justin; Meng, Kevin; Zhao, Shaohua; McDermott, Patrick; Brown, Eric; Meng, Jianghong
2018-06-01
Multidrug-resistant (MDR) plasmids play an important role in disseminating antimicrobial resistance genes. To elucidate the antimicrobial resistance gene compositions in A/C incompatibility complex (IncA/C) plasmids carried by animal-derived MDR Salmonella Newport, and to investigate the spread mechanism of IncA/C plasmids, this study characterizes the complete nucleotide sequences of IncA/C plasmids by comparative analysis. Complete nucleotide sequencing of plasmids and chromosomes of six MDR Salmonella Newport strains was performed using PacBio RSII. Open reading frames were assigned using prokaryotic genome annotation pipeline (PGAP). To understand genomic diversity and evolutionary relationships among Salmonella Newport IncA/C plasmids, we included three complete IncA/C plasmid sequences with similar backbones from Salmonella Newport and Escherichia coli: pSN254, pAM04528, and peH4H, and additional 200 draft chromosomes. With the exception of canine isolate CVM22462, which contained an additional IncI1 plasmid, each of the six MDR Salmonella Newport strains contained only the IncA/C plasmid. These IncA/C plasmids (including references) ranged in size from 80.1 (pCVM21538) to 176.5 kb (pSN254) and carried various resistance genes. Resistance genes floR, tetA, tetR, strA, strB, sul, and mer were identified in all IncA/C plasmids. Additionally, bla CMY-2 and sugE were present in all IncA/C plasmids, excepting pCVM21538. Plasmid pCVM22462 was capable of being transferred by conjugation. The IncI1 plasmid pCVM22462b in CVM22462 carried bla CMY-2 and sugE. Our data showed that MDR Salmonella Newport strains carrying similar IncA/C plasmids clustered together in the phylogenetic tree using chromosome sequences and the IncA/C plasmids from animal-derived Salmonella Newport contained diverse resistance genes. In the current study, we analyzed genomic diversities and phylogenetic relationships among MDR Salmonella Newport using complete plasmids and chromosome sequences and provided possible spread mechanism of IncA/C plasmids in Salmonella Newport Lineage II.
-
Montasser, Mona A; Viana, Grace; Evans, Carla A
2017-04-01
To investigate the presence of secular trends in skeletal maturation of girls and boys as assessed by the use of cervical vertebrae bones. The study compared two main groups: the first included data collected from the Denver growth study (1930s to 1960s) and the second included data collected from recent pretreatment records (1980s to 2010s) of patients from the orthodontic clinic of a North American University. The records from the two groups were all for Caucasian subjects. The sample for each group included 78 lateral cephalographs for girls and the same number for boys. The age of the subjects ranged from 7 to 18 years. Cervical vertebrae maturation (CVM) stages were directly assessed from the radiographs according to the method described by Hassel and Farman in which six CVM stages were designated from cervical vertebrae 2, 3, and 4. The mean age of girls from the Denver growth study and girls from the university clinic in each of the six CVM stages was not different at P ≤0.05. However, the mean age of boys from the two groups was not different only in stage 3 (P = 0.139) and stage 4 (P = 0.211). The results showed no evidence to indicate a tendency for earlier skeletal maturation of girls or boys. Boys in the university group started their skeletal maturation later than boys in the Denver group and completed their maturation earlier. Gender was a significant factor affecting skeletal maturation stages in both Denver and university groups. © The Author 2016. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com
-
Estimating irrigation water demand in the Moroccan Drâa Valley using contingent valuation.
Storm, Hugo; Heckelei, Thomas; Heidecke, Claudia
2011-10-01
Irrigation water management is crucial for agricultural production and livelihood security in Morocco as in many other parts of the world. For the implementation of an effective water management, knowledge about farmers' demand for irrigation water is crucial to assess reactions to water pricing policy, to establish a cost-benefit analysis of water supply investments or to determine the optimal water allocation between different users. Previously used econometric methods providing this information often have prohibitive data requirements. In this paper, the Contingent Valuation Method (CVM) is adjusted to derive a demand function for irrigation water along farmers' willingness to pay for one additional unit of surface water or groundwater. An application in the Middle Drâa Valley in Morocco shows that the method provides reasonable results in an environment with limited data availability. For analysing the censored survey data, the Least Absolute Deviation estimator was found to be a more suitable alternative to the Tobit model as errors are heteroscedastic and non-normally distributed. The adjusted CVM to derive demand functions is especially attractive for water scarce countries under limited data availability. Copyright © 2011 Elsevier Ltd. All rights reserved.
-
AntigenMap 3D: an online antigenic cartography resource.
Barnett, J Lamar; Yang, Jialiang; Cai, Zhipeng; Zhang, Tong; Wan, Xiu-Feng
2012-05-01
Antigenic cartography is a useful technique to visualize and minimize errors in immunological data by projecting antigens to 2D or 3D cartography. However, a 2D cartography may not be sufficient to capture the antigenic relationship from high-dimensional immunological data. AntigenMap 3D presents an online, interactive, and robust 3D antigenic cartography construction and visualization resource. AntigenMap 3D can be applied to identify antigenic variants and vaccine strain candidates for pathogens with rapid antigenic variations, such as influenza A virus. http://sysbio.cvm.msstate.edu/AntigenMap3D
-
Byun, Bo-Ram; Kim, Yong-Il; Yamaguchi, Tetsutaro; Maki, Koutaro; Ko, Ching-Chang; Hwang, Dea-Seok; Park, Soo-Byung; Son, Woo-Sung
2015-11-01
The purpose of this study was to establish multivariable regression models for the estimation of skeletal maturation status in Japanese boys and girls using the cone-beam computed tomography (CBCT)-based cervical vertebral maturation (CVM) assessment method and hand-wrist radiography. The analyzed sample consisted of hand-wrist radiographs and CBCT images from 47 boys and 57 girls. To quantitatively evaluate the correlation between the skeletal maturation status and measurement ratios, a CBCT-based CVM assessment method was applied to the second, third, and fourth cervical vertebrae. Pearson's correlation coefficient analysis and multivariable regression analysis were used to determine the ratios for each of the cervical vertebrae (p < 0.05). Four characteristic parameters ((OH2 + PH2)/W2, (OH2 + AH2)/W2, D2, AH3/W3), as independent variables, were used to build the multivariable regression models: for the Japanese boys, the skeletal maturation status according to the CBCT-based quantitative cervical vertebral maturation (QCVM) assessment was 5.90 + 99.11 × AH3/W3 - 14.88 × (OH2 + AH2)/W2 + 13.24 × D2; for the Japanese girls, it was 41.39 + 59.52 × AH3/W3 - 15.88 × (OH2 + PH2)/W2 + 10.93 × D2. The CBCT-generated CVM images proved very useful to the definition of the cervical vertebral body and the odontoid process. The newly developed CBCT-based QCVM assessment method showed a high correlation between the derived ratios from the second cervical vertebral body and odontoid process. There are high correlations between the skeletal maturation status and the ratios of the second cervical vertebra based on the remnant of dentocentral synchondrosis.
-
Diagnostic performance of dental maturity for identification of skeletal maturation phase.
Perinetti, G; Contardo, L; Gabrieli, P; Baccetti, T; Di Lenarda, R
2012-08-01
The objective of this study is to analyse the diagnostic performance of the circumpubertal dental maturation phases for the identification of individual-specific skeletal maturation phases. A total of 354 healthy subjects, 208 females and 146 males (mean age, 11.1 ± 2.4 years; range, 6.8-17.1 years), were enrolled in the study. Dental maturity was assessed through the calcification stages from panoramic radiographs of the mandibular canine, the first and second premolars, and the second molar. Determination of skeletal maturity was according to the cervical vertebra maturation (CVM) method on lateral cephalograms. Diagnostic performances were evaluated according to the dental maturation stages for each tooth for the identification of the CVM stages and growth phases (as pre-pubertal, pubertal, and post-pubertal) using positive likelihood ratios (LHRs). A positive LHR threshold of 10 or more was considered for satisfactory reliability of any dental maturation stage for the identification of any of the CVM stages or growth phases. The positive LHRs were generally less than 2.0, with a few exceptions. These four teeth showed positive LHRs greater than 10 only for the identification of the pre-pubertal growth phase, with values from 10.8 for the second molar (stage E) to 39.3 for the first premolar (stage E). Dental maturation assessment is only useful for diagnosis of the pre-pubertal growth phase, and thus, precise information in relation to the timing of the onset of the growth spurt is not provided by these indices.
-
DOE Office of Scientific and Technical Information (OSTI.GOV)
Heiblum, Reuven H.; Altaratz, Orit; Koren, Ilan
2016-06-07
In Part I of this work a 3D cloud tracking algorithm and phase-space of center of gravity altitude versus cloud liquid water mass (CvM space) were introduced and described in detail. We showed how new physical insight can be gained by following cloud trajectories in the CvM space. Here, this approach is used to investigate aerosol effects on cloud fields of warm cumuli. We show a clear effect of the aerosol loading on the shape and size of CvM clusters. We also find fundamental differences in the CvM space between simulations using bin versus bulk microphysical schemes, with the binmore » scheme precipitation expressing much higher sensitivity to changes in aerosol concentrations. Using the bin microphysical scheme, we find that the increase in cloud center of gravity altitude with increase in aerosol concentrations occurs for a wide range of cloud sizes. This is attributed to reduced sedimentation, increased buoyancy and vertical velocities, and increased environmental instability, all of which are tightly coupled to inhibition of precipitation processes and subsequent feedbacks of clouds on their environment. Many of the physical processes shown here are consistent with processes typically associated with cloud invigoration.« less
-
John B. Loomis; Le Trong Hung; Armando Gonzalez-Caban
2009-01-01
This research uses the Contingent Valuation Method to test whether willingness to pay increases for larger reductions in acres of forests burned by wildfires across the states of California. Florida and Montana. This is known as a test of scope, a measure of internal validity of the contingent valuation method (CVM). The scope test is conducted separately for White...
-
Demand for health care in Denmark: results of a national sample survey using contingent valuation.
Gyldmark, M; Morrison, G C
2001-10-01
In this paper we use willingness to pay (WTP) to elicit values for private insurance covering treatment for four different health problems. By way of obtaining these values, we test the viability of the contingent valuation method (CVM) and econometric techniques, respectively, as means of eliciting and analysing values from the general public. WTP responses from a Danish national sample survey, which was designed in accordance with existing guidelines, are analysed in terms of consistency and validity checks. Large numbers of zero responses are common in WTP studies, and are found here; therefore, the Heckman selectivity model and log-transformed OLS are employed. The selectivity model is rejected, but test results indicate that the lognormal model yields efficient and unbiased estimates. The results give confidence in the WTP estimates obtained and, more generally, in CVM as a means of valuing publicly provided goods and in econometrics as a tool for analysing WTP results containing many zero responses.
-
Zhao, Jun; Liu, Qiuxia; Lin, Liqing; Lv, Huafang; Wang, Yao
2013-08-01
Around 2000, China began to address the comprehensive restoration of its urban rivers and attempt to restore river ecosystem services. This paper reports an integrated contingent valuation of the ecosystem services of Zhangjiabang Creek in Shanghai, which is in the most developed region of China. A total of 1440 questionnaires were delivered, and 1153 were returned as usable in August 2008. The willingness to pay for the restoration of the urban river is 20.22 RMB (2.91 USD) per month per household under the payment card and 110.64 RMB (15.92 USD) under the dichotomous format. Several important methodological issues of the contingent valuation method (CVM) are observed, including the disparity between willingness to pay and willingness to accept, the difference between payment card and dichotomous choice question formats, and the comparison of different models in welfare estimation using dichotomous choice data. Several new findings are disclosed for these three issues of CVM. Copyright © 2013 Elsevier B.V. All rights reserved.
-
Padalino, Saverio; Sfondrini, Maria Francesca; Chenuil, Laura; Scudeller, Luigia; Gandini, Paola
2014-12-01
The aim of this study was to assess the feasibility of skeletal maturation analysis using the Cervical Vertebrae Maturation (CVM) method by means of dedicated software, developed in collaboration with Outside Format (Paullo-Milan), as compared with manual analysis. From a sample of patients aged 7-21 years, we gathered 100 lateral cephalograms, 20 for each of the five CVM stages. For each cephalogram, we traced cervical vertebrae C2, C3 and C4 by hand using a lead pencil and an acetate sheet and dedicated software. All the tracings were made by an experienced operator (a dentofacial orthopedics resident) and by an inexperienced operator (a student in dental surgery). Each operator recorded the time needed to make each tracing in order to demonstrate differences in the times taken. Concordance between the manual analysis and the analysis performed using the dedicated software was 94% for the resident and 93% for the student. Interobserver concordance was 99%. The hand-tracing was quicker than that performed by means of the software (28 seconds more on average). The cervical vertebrae analysis software offers excellent clinical performance, even if the method takes longer than the manual technique. Copyright © 2014 Elsevier Masson SAS. All rights reserved.
-
DOE Office of Scientific and Technical Information (OSTI.GOV)
Heiblum, Reuven H.; Altaratz, Orit; Koren, Ilan
We study the evolution of warm convective cloud fields using large eddy simulations of continental and trade cumulus. Individual clouds are tracked a posteriori from formation to dissipation using a 3D cloud tracking algorithm and results are presented in the phase- space of center of gravity altitude versus cloud liquid water mass (CvM space). The CvM space is shown to contain rich information on cloud field characteristics, cloud morphology, and common cloud development pathways, together facilitating a comprehensive understanding of the cloud field. In this part we show how the meteorological (thermodynamic) conditions that determine the cloud properties are projectedmore » on the CvM phase space and how changes in the initial conditions affect the clouds' trajectories in this space. This part sets the stage for a detailed microphysical analysis that will be shown in part II.« less
-
Cervical vertebral bone mineral density changes in adolescents during orthodontic treatment.
Crawford, Bethany; Kim, Do-Gyoon; Moon, Eun-Sang; Johnson, Elizabeth; Fields, Henry W; Palomo, J Martin; Johnston, William M
2014-08-01
The cervical vertebral maturation (CVM) stages have been used to estimate facial growth status. In this study, we examined whether cone-beam computed tomography images can be used to detect changes of CVM-related parameters and bone mineral density distribution in adolescents during orthodontic treatment. Eighty-two cone-beam computed tomography images were obtained from 41 patients before (14.47 ± 1.42 years) and after (16.15 ± 1.38 years) orthodontic treatment. Two cervical vertebral bodies (C2 and C3) were digitally isolated from each image, and their volumes, means, and standard deviations of gray-level histograms were measured. The CVM stages and mandibular lengths were also estimated after converting the cone-beam computed tomography images. Significant changes for the examined variables were detected during the observation period (P ≤0.018) except for C3 vertebral body volume (P = 0.210). The changes of CVM stage had significant positive correlations with those of vertebral body volume (P ≤0.021). The change of the standard deviation of bone mineral density (variability) showed significant correlations with those of vertebral body volume and mandibular length for C2 (P ≤0.029). The means and variability of the gray levels account for bone mineral density and active remodeling, respectively. Our results indicate that bone mineral density distribution and the volume of the cervical vertebral body changed because of active bone remodeling during maturation. Copyright © 2014 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.
-
NASA Technical Reports Server (NTRS)
Kimmel, W. M.; Kuhn, N. S.; Berry, R. F.; Newman, J. A.
2001-01-01
An overview and status of current activities seeking alternatives to 200 grade 18Ni Steel CVM alloy for cryogenic wind tunnel models is presented. Specific improvements in material selection have been researched including availability, strength, fracture toughness and potential for use in transonic wind tunnel testing. Potential benefits from utilizing damage tolerant life-prediction methods, recently developed fatigue crack growth codes and upgraded NDE methods are also investigated. Two candidate alloys are identified and accepted for cryogenic/transonic wind tunnel models and hardware.
-
Tuliani, Tushar A; Shenoy, Maithili; Belgrave, Kevin; Deshmukh, Abhishek; Pant, Sadip; Hilliard, Anthony; Afonso, Luis
2017-09-01
Studies suggest that subclinical hypothyroidism (SCH) is related to cardiovascular mortality (CVM). We explored the role of microalbuminuria (MIA) as a predictor of long-term CVM in population with and without SCH with normal kidney function. We examined the National Health and Nutrition Education Survey - III database (n = 6,812). Individuals younger than 40 years, thyroid-stimulating hormone levels ≥20 and ≤0.35mIU/L, estimated glomerular filtration rate <60mL/minute/1.73m 2 and urine albumin-to-creatinine ratio of >250mg/g in men and >355mg/g in women were excluded. SCH was defined as thyroid-stimulating hormone levels between 5 and 19.99mIU/L and serum T4 levels between 5 and 12µg/dL. MIA was defined as urine albumin-to-creatinine ratio of 17-250mg/g in men and 25-355mg/g in women. Patients were categorized into the following 4 groups: (1) no SCH or MIA, (2) MIA, but no SCH, (3) SCH, but no MIA and (4) both SCH and MIA. Prevalence of MIA in the subclinical hypothyroid cohort was 21% compared to 16.4% in those without SCH (P = 0.03). SCH was a significant independent predictor of MIA (n = 6,812), after adjusting for traditional risk factors (unadjusted odds ratio = 1.75; 95% CI: 1.24-2.48; P = 0.002 and adjusted odds ratio = 1.83; 95% CI: 1.2-2.79; P = 0.006). MIA was a significant independent predictor of long-term all-cause (adjusted hazard ratio = 1.7, 95% CI: 1.24-2.33) and CVM (adjusted hazard ratio = 1.72, 95% CI: 1.07-2.76) in subclinical hypothyroid individuals. In a cohort of subclinical hypothyroid individuals, the presence of MIA predicts increased risk of CVM as compared to nonmicroalbuminurics with SCH. Further randomized trials are needed to assess the benefits of treating microalbuminuric subclinical hypothyroid individuals and impact on CVM. Copyright © 2017 Southern Society for Clinical Investigation. Published by Elsevier Inc. All rights reserved.
-
Qi, Xiaoyang; Flick, Matthew J.; Frederick, Malinda; Chu, Zhengtao; Mason, Rachel; DeLay, Monica; Thornton, Sherry
2012-01-01
Rheumatoid arthritis is a chronic inflammatory disease affecting approximately 1% of the population and is characterized by cartilage and bone destruction ultimately leading to loss of joint function. Early detection and intervention of disease provides the best hope for successful treatment and preservation of joint mobility and function. Reliable and non-invasive techniques that accurately measure arthritic disease onset and progression are lacking. We recently developed a novel agent, SapC-DOPS, which is composed of the membrane-associated lysosomal protein saposin C (SapC) incorporated into 1,2-dioleoyl-sn-glycero-3-phospho-L-serine (DOPS) lipid nanovesicles. SapC-DOPS has a high fusogenic affinity for phosphatidylserine-enriched microdomains on surfaces of target cell membranes. Incorporation of a far-red fluorophore, CellVue Maroon (CVM), into the nanovesicles allows for in vivo non-invasive visualization of the agent in targeted tissue. Given that phosphatidylserine is present only on the inner leaflet of healthy plasma membranes but is “flipped” to the outer leaflet upon cell damage, we hypothesized that SapC-DOPS would target tissue damage associated with inflammatory arthritis due to local surface-exposure of phosphatidylserine. Optical imaging with SapC-DOPS-CVM in two distinct models of arthritis, serum-transfer arthritis (e.g., K/BxN) and collagen-induced arthritis (CIA) revealed robust SapC-DOPS-CVM specific localization to arthritic paws and joints in live animals. Importantly, intensity of localized fluorescent signal correlated with macroscopic arthritic disease severity and increased with disease progression. Flow cytometry of cells extracted from arthritic joints demonstrated that SapC-DOPS-CVM localized to an average of 7–8% of total joint cells and primarily to CD11b+Gr-1+ cells. Results from the current studies strongly support the application of SapC-DOPS-CVM for advanced clinical and research applications including: detecting early arthritis onset, assessing disease progression real-time in live subjects, and providing novel information regarding cell types that may mediate arthritis progression within joints. PMID:22470501
-
Dental and skeletal maturation in female adolescents with temporomandibular joint osteoarthritis.
Kang, J-H; Yang, I-H; Hyun, H-K; Lee, J-Y
2017-11-01
Occurrence of temporomandibular disorders (TMDs) and temporomandibular joint (TMJ) osteoarthritis (OA) during adolescence may have interactions with mandibular and dental development. The aim of the present study was to investigate relationships between occurrence of TMD and TMJ OA and extents of dental and skeletal development in juvenile female patients. In total, 95 female adolescents (age range, 11-15 years) were selected. Among them, 15 subjects (control) had no signs of TMD, 39 TMD patients did not have OA (TMDnoOA), 17 TMD patients were at initial stage of TMJ OA (TMJOA), and 27 patients showed progressive stage of TMJ OA (TMJOA). Dental age was estimated by Demirjian's stages used in a previous study with Korean adolescents. Craniofacial parameters and cervical vertebrae maturation (CVM) stages, representing skeletal maturity levels, were measured using lateral cephalograms. The estimated dental age was significantly lower than chronological age in all groups, but CVM differences were not statistically significant. Dental age was the lowest, and differences between the chronological age and estimated dental age were the highest among initial stage of TMJOAs followed by progressive stage of TMJOAs, TMDnoOAs and control and were not associated with CVM stages. Cephalometric parameters revealed significant clockwise rotation of the mandible among the TMJOAs compared with controls and TMDnoOAs and were not associated with CVM stages as well. The juvenile female patients with TMD, particularly TMJ OA, showed retarded dental development, mandibular backward positioning and hyperdivergent facial profiles. The TMJ OA may be associated with retarded dental development but not with skeletal maturations. © 2017 John Wiley & Sons Ltd.
-
Passive imaging of hydrofractures in the South Belridge diatomite
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ilderton, D.C.; Patzek, T.W.; Rector, J.W.
1996-03-01
The authors present the results of a seismic analysis of two hydrofractures spanning the entire diatomite column (1,110--1,910 ft or 338--582 m) in Shell`s Phase 2 steam drive pilot in South Belridge, California. These hydrofractures were induced at two depths (1,110--1,460 and 1,560--1,910 ft) and imaged passively using the seismic energy released during fracturing. The arrivals of shear waves from the cracking rock (microseismic events) were recorded at a 1 ms sampling rate by 56 geophones in three remote observation wells, resulting in 10 GB of raw data. These arrival times were then inverted for the event locations, from whichmore » the hydrofracture geometry was inferred. A five-dimensional conjugate-gradient algorithm with a depth-dependent, but otherwise constant shear wave velocity model (CVM) was developed for the inversions. To validate CVM, they created a layered shear wave velocity model of the formation and used it to calculate synthetic arrival times from known locations chosen at various depths along the estimated fracture plane. These arrival times were then inverted with CVM and the calculated locations compared with the known ones, quantifying the systematic error associated with the assumption of constant shear wave velocity. They also performed Monte Carlo sensitivity analyses on the synthetic arrival times to account for all other random errors that exist in field data. After determining the limitations of the inversion algorithm, they hand-picked the shear wave arrival times for both hydrofractures and inverted them with CVM.« less
-
NASA Astrophysics Data System (ADS)
Lee, En-Jui; Chen, Po
2017-04-01
More precise spatial descriptions of fault systems play an essential role in tectonic interpretations, deformation modeling, and seismic hazard assessments. The recent developed full-3D waveform tomography techniques provide high-resolution images and are able to image the material property differences across faults to assist the understanding of fault systems. In the updated seismic velocity model for Southern California, CVM-S4.26, many velocity gradients show consistency with surface geology and major faults defined in the Community Fault Model (CFM) (Plesch et al. 2007), which was constructed by using various geological and geophysical observations. In addition to faults in CFM, CVM-S4.26 reveals a velocity reversal mainly beneath the San Gabriel Mountain and Western Mojave Desert regions, which is correlated with the detachment structure that has also been found in other independent studies. The high-resolution tomographic images of CVM-S4.26 could assist the understanding of fault systems in Southern California and therefore benefit the development of fault models as well as other applications, such as seismic hazard analysis, tectonic reconstructions, and crustal deformation modeling.
-
Eruption of the permanent maxillary canines in relation to mandibular second molar maturity.
Perinetti, Giuseppe; Callovi, Marilena; Salgarello, Stefano; Biasotto, Matteo; Contardo, Luca
2013-07-01
To evaluate the timing of spontaneous maxillary canine eruption in relation to stages of mandibular second molar maturation. Potential confounding effects from such factors as age, growth phase, and facial features were also explored. A sample of 106 healthy subjects (48 females and 58 males; age range, 9.4-14.3 years) with both permanent maxillary canines during the final phase of intraoral eruption were included. Mandibular second molar maturation (stages E to H) was assessed according to the method of Demirjian. Skeletal maturity was determined using the cervical vertebral maturational (CVM) method. Facial vertical and sagittal relationships were evaluated by recording the Sella-Nasion/mandibular plane (SN/MP) angle and the ANB angle. An ordered multiple logistic regression was run to evaluate adjusted correlation of each parameter with the mandibular second molar maturational stage. Overall, the prevalence of the different second molar maturational stages was 36.8%, 37.8%, and 27.4% for stages E, F and G, respectively. According to the regression model, this relation was not influenced by sex, CVM stage, SN/MP angle, and ANB angle. Irrespective of sex, growth phase, and facial features, the maturational stage of the mandibular second molar may be a reliable indicator for the timing of spontaneous eruption of the maxillary canine.
-
Perinetti, G; Baccetti, T; Contardo, L; Di Lenarda, R
2011-02-01
To evaluate the gingival crevicular fluid (GCF) alkaline phosphatase (ALP) activity in growing subjects in relation to the stages of individual skeletal maturation. The Department of Biomedicine, University of Trieste. Seventy-two healthy growing subjects (45 women and 27 men; range, 7.8-17.7 years). Double-blind, prospective, cross-sectional design. Samples of GCF were collected from each subject at the mesial and distal sites of both of the central incisors, in the maxilla and mandible. Skeletal maturation phase was assessed through the cervical vertebral maturation (CVM) method. Enzymatic activity was determined spectrophotometrically. The relationship between GCF ALP activity and CVM stages was significant. In particular, a twofold peak in enzyme activity was seen at the CS3 and CS4 pubertal stages, compared to the pre-pubertal stages (CS1 and CS2) and post-pubertal stages (CS5 and CS6), at both the maxillary and mandibular sites. No differences were seen between the maxillary and mandibular sites, or between the sexes. As an adjunct to standard methods based upon radiographic parameters, the GCF ALP may be a candidate as a non-invasive clinical biomarker for the identification of the pubertal growth spurt in periodontally healthy subjects scheduled for orthodontic treatment. © 2010 John Wiley & Sons A/S.
-
Muco-inert nanoparticle probes and drug carriers
NASA Astrophysics Data System (ADS)
Wang, Ying-Ying
2011-12-01
Mucus coats the exposed surfaces of the eyes and respiratory, gastrointestinal (GI) and cervicovaginal (CV) tracts, and protects mucosal tissues against pathogens and other foreign particulates. Most foreign particles are effectively trapped in mucus through steric and adhesive interactions, and are rapidly eliminated by different mucus clearance mechanisms. Nevertheless, mucus also immobilizes conventional drug and gene carriers, thereby precluding sustained and targeted drug delivery to mucosal sites. Synthetic particles engineered with muco-inert surfaces, and some viruses, can readily penetrate mucus gel, and may serve as useful probes to understand the biophysical barrier properties of mucus. Improved understanding of the mucus barrier could provide insights into methods to enhance drug and gene delivery at mucosal surfaces, as well as understanding the occasional failure of mucus to protect against infection or injury. Recently, muco-inert nanoparticles were developed by conjugating a dense layer of low MW polyethylene glycol to particle surfaces. Since they are slowed only by steric obstruction from the mucus mesh, various sized muco-inert nanoparticles can be used to probe the microstructure and microrheology of mucus. I applied this technique to determine whether the mucus barrier may be altered by exogenous factors, including the presence of detergent, pH changes and synthetic nanoparticles. I first studied the microrheology of native human cervicovaginal mucus (CVM), and found that CVM behaves as a viscoelastic solid at length scales ≥ 1 microm (preventing large particles from diffusing through) but as a viscoelastic liquid at length scales up to at least 500 nm (allowing smaller particles to diffuse through low viscosity fluid-filled pores). Treating CVM with a nonionic detergent, N9, shifted the viscoelastic liquid-solid transition point to < 200 nm, suggesting hydrophobic interactions between mucin fibers play an important role in regulating the mucus microstructure and consequently the microrheology. Indeed, N9 caused the average mucus pore size to decrease from ˜340 nm to 130 nm. I then looked at the effect of pH on mucus and found that the microstructure of CVM is essentially pH-independent over a broad range of physiological pH. Between pH 4 (the native pH of CVM) and 6--7, the average pore size in the mucus mesh remained unchanged, and between pH 1--2 and 8--9, there was at most a 2-fold drop in the average pore size (likely due to changes in electrostatic vs. hydrophobic interactions between mucin fibers). Finally, I found that mucoadhesive synthetic nanoparticles, at sufficiently high concentrations, can bundle mucin fibers and create large openings in the mucus microstructure. Disruption of the mucus barrier in this manner allowed a greater fraction of large (1 microm) muco-inert particles to diffuse through the mucus mesh. Muco-inert nanoparticles---also referred to as "mucus-penetrating particles" (MPP)---offer the potential for sustained and targeted drug delivery to mucosal surfaces. By penetrating luminal mucus layers, MPP may be able to reach the slowly cleared adherent mucus layer or deep folds of the epithelium and thereby achieve prolonged retention. I first measured the long range penetration of MPP compared to conventional mucoadhesive particles (CP) into CVM. With minimal dilution of CVM, MPP could penetrate up to 200 microm over 1 hr with ˜530 particles/mm2 penetrating 100 microm or more, while CP remained immobilized (note that physiological mucus layer thicknesses are no more than ˜200 microm). Furthermore, with 30% v/v dilution, MPP could penetrate up to 1.5 mm over 1 hr with ˜74,000 particles/mm2 penetrating 100 microm or more, while CP continued to remain stuck. I then studied the distribution and retention of MPP vs. CP in the mouse vagina to determine whether improved mucus penetration leads to more uniform distribution and prolonged retention. I found that MPP were not only more uniformly distributed in the vaginal lumen, but also penetrated deep into epithelial folds. In contrast, CP were aggregated by luminal mucus and failed to reach the epithelium. Several-fold more MPP were retained on the vaginal epithelial surface than CP over at least ˜1 day. Drug and gene carriers that provide more uniform and longer-lasting coverage of mucosal surfaces may greatly improve the treatment or prevention of diseases at mucosal sites.
-
2018-01-01
A gambling or “game” phenomenon can be observed in the complex relationship between sources and receptors of ecological compensation among multiple stakeholders. This paper investigates the problem of gambling to determine payment amounts, and details a method to estimate the ecological compensation amount related to water resources in the Wuxijiang River reservoir area in China. Public statistics and first-hand data obtained from a field investigation were used as data sources. Estimation of the source and receptor amount of ecological compensation relevant to the water resource being investigated was achieved using the contingent valuation method (CVM). The ecological compensation object and its benefit and gambling for the Wuxijiang River water source area are also analyzed in this paper. According to the results of a CVM survey, the ecological compensation standard for the Wuxijiang River was determined by the CVM, and the amount of compensation was estimated. Fifteen blocks downstream of the Wuxijiang River and 12 blocks in the water source area were used as samples to administer a survey that estimated the willingness to pay (WTP) and the willingness to accept (WTA) the ecological compensation of Wuxijiang River for both nonparametric and parametric estimation. Finally, the theoretical value of the ecological compensation amount was estimated. Without taking other factors into account, the WTP of residents in the Wuxi River water source was 297.48 yuan per year, while the WTAs were 3864.48 yuan per year. The theoretical standard of ecological compensation is 2294.39–2993.81 yuan per year. Under the parameter estimation of other factors, the WTP of residents in the Wuxi River water source area was 528.72 yuan per year, while the WTA was 1514.04 yuan per year. The theoretical standard of ecological compensation is 4076.25–5434.99 yuan per year. The main factors influencing the WTP ecological compensation in the Wuxi River basin are annual income and age. The main factors affecting WTA are gender and attention to the environment, age, marital status, local birth, and location in the main village. PMID:29568707
-
Shu, Lin
2018-01-01
A gambling or "game" phenomenon can be observed in the complex relationship between sources and receptors of ecological compensation among multiple stakeholders. This paper investigates the problem of gambling to determine payment amounts, and details a method to estimate the ecological compensation amount related to water resources in the Wuxijiang River reservoir area in China. Public statistics and first-hand data obtained from a field investigation were used as data sources. Estimation of the source and receptor amount of ecological compensation relevant to the water resource being investigated was achieved using the contingent valuation method (CVM). The ecological compensation object and its benefit and gambling for the Wuxijiang River water source area are also analyzed in this paper. According to the results of a CVM survey, the ecological compensation standard for the Wuxijiang River was determined by the CVM, and the amount of compensation was estimated. Fifteen blocks downstream of the Wuxijiang River and 12 blocks in the water source area were used as samples to administer a survey that estimated the willingness to pay (WTP) and the willingness to accept (WTA) the ecological compensation of Wuxijiang River for both nonparametric and parametric estimation. Finally, the theoretical value of the ecological compensation amount was estimated. Without taking other factors into account, the WTP of residents in the Wuxi River water source was 297.48 yuan per year, while the WTAs were 3864.48 yuan per year. The theoretical standard of ecological compensation is 2294.39-2993.81 yuan per year. Under the parameter estimation of other factors, the WTP of residents in the Wuxi River water source area was 528.72 yuan per year, while the WTA was 1514.04 yuan per year. The theoretical standard of ecological compensation is 4076.25-5434.99 yuan per year. The main factors influencing the WTP ecological compensation in the Wuxi River basin are annual income and age. The main factors affecting WTA are gender and attention to the environment, age, marital status, local birth, and location in the main village.
-
Yu, Tao; Wang, Ying-Ying; Yang, Ming; Schneider, Craig; Zhong, Weixi; Pulicare, Sarah; Choi, Woo-Jin; Mert, Olcay; Fu, Jie; Lai, Samuel K.; Hanes, Justin
2013-01-01
Mucus secretions coating entry points to the human body that are not covered by skin efficiently trap and clear conventional drug carriers, limiting controlled drug delivery at mucosal surfaces. To overcome this challenge, we recently engineered nanoparticles that readily penetrate a variety of human mucus secretions, which we termed mucus-penetrating particles (MPP). Here, we report a new biodegradable MPP formulation based on diblock copolymers of poly(lactic-co-glycolic acid) and poly(ethylene glycol) (PLGA-PEG). PLGA-PEG nanoparticles prepared by a solvent diffusion method rapidly diffused through fresh, undiluted human cervicovaginal mucus (CVM) with an average speed only eightfold lower than their theoretical speed in water. In contrast, PLGA nanoparticles were slowed more than 12,000-fold in the same CVM secretions. Based on the measured diffusivities, as much as 75% of the PLGA-PEG nanoparticles are expected to penetrate a 10-μm-thick mucus layer within 30 min, whereas virtually no PLGA nanoparticles are expected to do so over the same duration. These results encourage further development of PLGA-PEG nanoparticles as mucus-penetrating drug carriers for improved drug and gene delivery to mucosal surfaces. PMID:24205449
-
NASA Astrophysics Data System (ADS)
Harvey, Jean-Philippe
In this work, the possibility to calculate and evaluate with a high degree of precision the Gibbs energy of complex multiphase equilibria for which chemical ordering is explicitly and simultaneously considered in the thermodynamic description of solid (short range order and long range order) and liquid (short range order) metallic phases is studied. The cluster site approximation (CSA) and the cluster variation method (CVM) are implemented in a new minimization technique of the Gibbs energy of multicomponent and multiphase systems to describe the thermodynamic behaviour of metallic solid solutions showing strong chemical ordering. The modified quasichemical model in the pair approximation (MQMPA) is also implemented in the new minimization algorithm presented in this work to describe the thermodynamic behaviour of metallic liquid solutions. The constrained minimization technique implemented in this work consists of a sequential quadratic programming technique based on an exact Newton’s method (i.e. the use of exact second derivatives in the determination of the Hessian of the objective function) combined to a line search method to identify a direction of sufficient decrease of the merit function. The implementation of a new algorithm to perform the constrained minimization of the Gibbs energy is justified by the difficulty to identify, in specific cases, the correct multiphase assemblage of a system where the thermodynamic behaviour of the equilibrium phases is described by one of the previously quoted models using the FactSage software (ex.: solid_CSA+liquid_MQMPA; solid1_CSA+solid2_CSA). After a rigorous validation of the constrained Gibbs energy minimization algorithm using several assessed binary and ternary systems found in the literature, the CVM and the CSA models used to describe the energetic behaviour of metallic solid solutions present in systems with key industrial applications such as the Cu-Zr and the Al-Zr systems are parameterized using fully consistent thermodynamic an structural data generated from a Monte Carlo (MC) simulator also implemented in the framework of this project. In this MC simulator, the modified embedded atom model in the second nearest neighbour formalism (MEAM-2NN) is used to describe the cohesive energy of each studied structure. A new Al-Zr MEAM-2NN interatomic potential needed to evaluate the cohesive energy of the condensed phases of this system is presented in this work. The thermodynamic integration (TI) method implemented in the MC simulator allows the evaluation of the absolute Gibbs energy of the considered solid or liquid structures. The original implementation of the TI method allowed us to evaluate theoretically for the first time all the thermodynamic mixing contributions (i.e., mixing enthalpy and mixing entropy contributions) of a metallic liquid (Cu-Zr and Al-Zr) and of a solid solution (face-centered cubic (FCC) Al-Zr solid solution) described by the MEAM-2NN. Thermodynamic and structural data obtained from MC and molecular dynamic simulations are then used to parameterize the CVM for the Al-Zr FCC solid solution and the MQMPA for the Al-Zr and the Cu-Zr liquid phase respectively. The extended thermodynamic study of these systems allow the introduction of a new type of configuration-dependent excess parameters in the definition of the thermodynamic function of solid solutions described by the CVM or the CSA. These parameters greatly improve the precision of these thermodynamic models based on experimental evidences found in the literature. A new parameterization approach of the MQMPA model of metallic liquid solutions is presented throughout this work. In this new approach, calculated pair fractions obtained from MC/MD simulations are taken into account as well as configuration-independent volumetric relaxation effects (regular like excess parameters) in order to parameterize precisely the Gibbs energy function of metallic melts. The generation of a complete set of fully consistent thermodynamic, physical and structural data for solid, liquid, and stoichiometric compounds and the subsequent parameterization of their respective thermodynamic model lead to the first description of the complete Al-Zr phase diagram in the range of composition [0 ≤ XZr ≤ 5 / 9] based on theoretical and fully consistent thermodynamic properties. MC and MD simulations are performed for the Al-Zr system to define for the first time the precise thermodynamic behaviour of the amorphous phase for its entire range of composition. Finally, all the thermodynamic models for the liquid phase, the FCC solid solution and the amorphous phase are used to define conditions based on thermodynamic and volumetric considerations that favor the amorphization of Al-Zr alloys.
-
Byun, Bo-Ram; Kim, Yong-Il; Yamaguchi, Tetsutaro; Maki, Koutaro; Son, Woo-Sung
2015-01-01
This study was aimed to examine the correlation between skeletal maturation status and parameters from the odontoid process/body of the second vertebra and the bodies of third and fourth cervical vertebrae and simultaneously build multiple regression models to be able to estimate skeletal maturation status in Korean girls. Hand-wrist radiographs and cone beam computed tomography (CBCT) images were obtained from 74 Korean girls (6-18 years of age). CBCT-generated cervical vertebral maturation (CVM) was used to demarcate the odontoid process and the body of the second cervical vertebra, based on the dentocentral synchondrosis. Correlation coefficient analysis and multiple linear regression analysis were used for each parameter of the cervical vertebrae (P < 0.05). Forty-seven of 64 parameters from CBCT-generated CVM (independent variables) exhibited statistically significant correlations (P < 0.05). The multiple regression model with the greatest R (2) had six parameters (PH2/W2, UW2/W2, (OH+AH2)/LW2, UW3/LW3, D3, and H4/W4) as independent variables with a variance inflation factor (VIF) of <2. CBCT-generated CVM was able to include parameters from the second cervical vertebral body and odontoid process, respectively, for the multiple regression models. This suggests that quantitative analysis might be used to estimate skeletal maturation status.
-
Casey, Christine; Gill, Daljit S; Jones, Steven P
2013-12-01
The aims of this study were to (1) investigate if there is a difference in skeletal maturation between tooth agenesis and control patients and (2) whether skeletal maturation is affected by the severity of tooth agenesis. The cervical vertebral maturation (CVM) index can be used to assess skeletal maturation. A retrospective cross-sectional study. Eastman Dental Hospital, London, UK. A total of 360 cephalograms of patients aged 9-17 years (164 males and 196 females) allocated to four subgroups (mild, moderate and severe tooth agenesis patients, and controls) were assessed retrospectively. There were 90 patients in each of the four subgroups. The skeletal maturation of each subject was assessed both quantitatively and qualitatively using the CVM index. All patients in the study were either currently receiving treatment or had been discharged from the hospital. There was no statistically significant relationship between skeletal maturation and the presence of tooth agenesis. Furthermore, there was no statistically significant relationship between the skeletal maturity of patients and different severities of tooth agenesis. The data obtained from this group of patients and using this measurement tool alone does not supply sufficient reason to reject the null hypothesis. However, it suggests that it is possible that no difference exists between the groups.
-
Comparing Value of Urban Green Space Using Contingent Valuation and Travel Cost Methods
NASA Astrophysics Data System (ADS)
Chintantya, Dea; Maryono
2018-02-01
Green urban open space are an important element of the city. They gives multiple benefits for social life, human health, biodiversity, air quality, carbon sequestration, and water management. Travel Cost Method (TCM) and Contingent Valuation Method (CVM) are the most frequently used method in various studies that assess environmental good and services in monetary term for valuing urban green space. Both of those method are determined the value of urban green space through willingness to pay (WTP) for ecosystem benefit and collected data through direct interview and questionnaire. Findings of this study showed the weaknesses and strengths of both methods for valuing urban green space and provided factors influencing the probability of user's willingness to pay in each method.
-
Automated detection of cracks on the faying surface within high-load transfer bolted speciments
NASA Astrophysics Data System (ADS)
Wheatley, Gregory; Kollgaard, Jeffrey R.
2003-07-01
Boeing is currently conducting evaluation testing of the Comparative Vacuum Monitoring (CVMTM) system offered by Structural Monitoring Systems, Ltd (SMS). Initial testing has been conducted by SMS, with further test lab validations to be performed at Boeing in Seattle. Testing has been conducted on dog bone type specimens that have been cut at the center line. A notch was cut at one of the bolt holes and a CVM sensor installed on both sides of the plate. The doublers were added and a single line of 4 bolts along the longitudinal center line were used to attach the doubler plates to the dog bone type specimen. In this way, a high load transfer situation exists between the two halves of the dog bone specimen and the doubler plates. The CVM sensors are slightly over 0.004" (0.1mm) in thickness and are installed directly upon the faying surface of the dog bone specimen. Testing was conducted on an Instron 8501 Servohydraulic testing machine at the Department of Mechanical and Materials Engineering, University of Western Australia. The standard laboratory equipment offered by Structural Monitoring Systems, Ltd was used for crack detection. This equipment included the Kvac (vacuum supply) and the Sim8 (flow meter). The Sim8 was electrically connected to the Instron machine so that as soon as a crack was detected, fatigue loading was halted. The aim of the experiment was for CVM to detect a crack on the faying surface of the specimens at a length of 0.050" +/- 0.010". This was accomplished successfully. CVM has been developed on the principle that a small volume maintained at a low vacuum is extremely sensitive to any ingress of air. In addition to the load bearing sensors described above, self-adhesive, elastomeric sensors with fine channels on the adhesive face have been developed. When the sensors have been adhered to the structure under test, these fine channels, and the structure itself, form a manifold of galleries alternately at low vacuum and atmospheric pressure. When a crack develops, it forms a leakage path between the atmospheric and vacuum galleries, producing a measurable change in the vacuum level. The sensors have several advantages over standard test methodologies. As the structure under test effectively becomes part of the sensor, the system measures the physical crack; there can be no false negatives. The elastomeric nature of the sensors allows them to conform to complex curves, and individual sensors can cover relatively large areas. The sensors are transparent; allowing visual inspection to occur without removal. Independent testing by a SMS client has confirmed that eddy current testing can be conducted through CVM sensors of 1mm thickness. The sensitivity of the sensor is governed by the gallery spacing and may be as low as 0.010" (250 μm). Finally, the sensors are also able to detect surface corrosion of aluminium structure. US Navy are monitoring crack growth on an H-53 helicopter with the portable CVM system offered by SMS.
-
Meullemiestre, A; Petitcolas, E; Maache-Rezzoug, Z; Chemat, F; Rezzoug, S A
2016-01-01
Maritime pine sawdust, a by-product from industry of wood transformation, has been investigated as a potential source of polyphenols which were extracted by ultrasound-assisted maceration (UAM). UAM was optimized for enhancing extraction efficiency of polyphenols and reducing time-consuming. In a first time, a preliminary study was carried out to optimize the solid/liquid ratio (6g of dry material per mL) and the particle size (0.26 cm(2)) by conventional maceration (CVM). Under these conditions, the optimum conditions for polyphenols extraction by UAM, obtained by response surface methodology, were 0.67 W/cm(2) for the ultrasonic intensity (UI), 40°C for the processing temperature (T) and 43 min for the sonication time (t). UAM was compared with CVM, the results showed that the quantity of polyphenols was improved by 40% (342.4 and 233.5mg of catechin equivalent per 100g of dry basis, respectively for UAM and CVM). A multistage cross-current extraction procedure allowed evaluating the real impact of UAM on the solid-liquid extraction enhancement. The potential industrialization of this procedure was implemented through a transition from a lab sonicated reactor (3 L) to a large scale one with 30 L volume. Copyright © 2015 Elsevier B.V. All rights reserved.
-
Englar, Ryane E; Williams, Melanie; Weingand, Kurt
2016-01-01
Effective communication in health care benefits patients. Medical and veterinary schools not only have a responsibility to teach communication skills, the American Veterinary Medical Association (AVMA) Council on Education (COE) requires that communication be taught in all accredited colleges of veterinary medicine. However, the best strategy for designing a communications curriculum is unclear. The Calgary-Cambridge Guide (CCG) is one of many models developed in human medicine as an evidence-based approach to structuring the clinical consultation through 71 communication skills. The model has been revised by Radford et al. (2006) for use in veterinary curricula; however, the best approach for veterinary educators to teach communication remains to be determined. This qualitative study investigated if one adaptation of the CCG currently taught at Midwestern University College of Veterinary Medicine (MWU CVM) fulfills client expectations of what constitutes clinically effective communication. Two focus groups (cat owners and dog owners) were conducted with a total of 13 participants to identify common themes in veterinary communication. Participants compared communication skills they valued to those taught by MWU CVM. The results indicated that while the CCG skills that MWU CVM adopted are applicable to cat and dog owners, they are not comprehensive. Participants expressed the need to expand the skillset to include compassionate transparency and unconditional positive regard. Participants also expressed different communication needs that were attributed to the species of companion animal owned.
-
Byun, Bo-Ram; Kim, Yong-Il; Maki, Koutaro; Son, Woo-Sung
2015-01-01
This study was aimed to examine the correlation between skeletal maturation status and parameters from the odontoid process/body of the second vertebra and the bodies of third and fourth cervical vertebrae and simultaneously build multiple regression models to be able to estimate skeletal maturation status in Korean girls. Hand-wrist radiographs and cone beam computed tomography (CBCT) images were obtained from 74 Korean girls (6–18 years of age). CBCT-generated cervical vertebral maturation (CVM) was used to demarcate the odontoid process and the body of the second cervical vertebra, based on the dentocentral synchondrosis. Correlation coefficient analysis and multiple linear regression analysis were used for each parameter of the cervical vertebrae (P < 0.05). Forty-seven of 64 parameters from CBCT-generated CVM (independent variables) exhibited statistically significant correlations (P < 0.05). The multiple regression model with the greatest R 2 had six parameters (PH2/W2, UW2/W2, (OH+AH2)/LW2, UW3/LW3, D3, and H4/W4) as independent variables with a variance inflation factor (VIF) of <2. CBCT-generated CVM was able to include parameters from the second cervical vertebral body and odontoid process, respectively, for the multiple regression models. This suggests that quantitative analysis might be used to estimate skeletal maturation status. PMID:25878721
-
Correlation between dental maturity and cervical vertebral maturity.
Chen, Jianwei; Hu, Haikun; Guo, Jing; Liu, Zeping; Liu, Renkai; Li, Fan; Zou, Shujuan
2010-12-01
The aim of this study was to investigate the association between dental and skeletal maturity. Digital panoramic radiographs and lateral skull cephalograms of 302 patients (134 boys and 168 girls, ranging from 8 to 16 years of age) were examined. Dental maturity was assessed by calcification stages of the mandibular canines, first and second premolars, and second molars, whereas skeletal maturity was estimated by the cervical vertebral maturation (CVM) stages. The Spearman rank-order correlation coefficient was used to measure the association between CVM stage and dental calcification stage of individual teeth. The mean chronologic age of girls was significantly lower than that of boys in each CVM stage. The Spearman rank-order correlation coefficients between dental maturity and cervical vertebral maturity ranged from 0.391 to 0.582 for girls and from 0.464 to 0.496 for boys (P < 0.05). In girls, the mandibular second molar had the highest and the canine the lowest correlation. In boys, the canine had the highest and the first premolar the lowest correlation. Tooth calcification stage was significantly correlated with cervical vertebral maturation stage. The development of the mandibular second molar in females and that of the mandibular canine in males had the strongest correlations with cervical vertebral maturity. Therefore, it is practical to consider the relationship between dental and skeletal maturity when planning orthodontic treatment. Copyright © 2010 Mosby, Inc. All rights reserved.
-
Van Moorsel, Guillaume
2005-01-01
Libraries often do not know how clients value their product/ service offerings. Yet at a time when the mounting costs for library support are increasingly difficult to justify to the parent institution, the library's ability to gauge the value of its offerings to clients has never been more critical. Client Value Models (CVMs) establish a common definition of value elements-or a "value vocabulary"-for libraries and their clients, thereby providing a basis upon which to make rational planning decisions regarding product/service acquisition and development. The CVM concept is borrowed from business and industry, but its application has a natural fit in libraries. This article offers a theoretical consideration and practical illustration of CVM application in libraries.
-
A Quantitative Evaluation of SCEC Community Velocity Model Version 3.0
NASA Astrophysics Data System (ADS)
Chen, P.; Zhao, L.; Jordan, T. H.
2003-12-01
We present a systematic methodology for evaluating and improving 3D seismic velocity models using broadband waveform data from regional earthquakes. The operator that maps a synthetic waveform into an observed waveform is expressed in the Rytov form D(ω ) = {exp}[{i} ω δ τ {p}(ω ) - ω δ τ {q}(ω )]. We measure the phase delay time δ τ p(ω ) and the amplitude reduction time δ τ q(ω ) as a function of frequency ω using Gee & Jordan's [1992] isolation-filter technique, and we correct the data for frequency-dependent interference and frequency-independent source statics. We have applied this procedure to a set of small events in Southern California. Synthetic seismograms were computed using three types of velocity models: the 1D Standard Southern California Crustal Model (SoCaL) [Dreger & Helmberger, 1993], the 3D SCEC Community Velocity Model, Version 3.0 (CVM3.0) [Magistrale et al., 2000], and a set of path-averaged 1D models (A1D) extracted from CVM3.0 by horizontally averaging wave slownesses along source-receiver paths. The 3D synthetics were computed using K. Olsen's finite difference code. More than 1000 measurements were made on both P and S waveforms at frequencies ranging from 0.2 to 1 Hz. Overall, the 3D model provided a substantially better fit to the waveform data than either laterally homogeneous or path-dependent 1D models. Relative to SoCaL, CVM3.0 provided a variance reduction of about 64% in δ τ p, and 41% in δ τ q. Relative to A1D, the variance reduction is about 46% and 20%, respectively. The same set of measurements can be employed to invert for both seismic source properties and seismic velocity structures. Fully numerical methods are being developed to compute the Fréchet kernels for these measurements [L. Zhao et. al., this meeting]. This methodology thus provides a unified framework for regional studies of seismic sources and Earth structure in Southern California and elsewhere.
-
How Much Are Floridians Willing to Pay for Protecting Sea Turtles from Sea Level Rise?
NASA Astrophysics Data System (ADS)
Hamed, Ahmed; Madani, Kaveh; Von Holle, Betsy; Wright, James; Milon, J. Walter; Bossick, Matthew
2016-01-01
Sea level rise (SLR) is posing a great inundation risk to coastal areas. Some coastal nesting species, including sea turtle species, have experienced diminished habitat from SLR. Contingent valuation method (CVM) was used in an effort to assess the economic loss impacts of SLR on sea turtle nesting habitats for Florida coasts; and to elicit values of willingness to pay (WTP) of Central Florida residents to implement certain mitigation strategies, which would protect Florida's east coast sea turtle nesting areas. Using the open-ended and dichotomous choice CVM, we sampled residents of two Florida communities: Cocoa Beach and Oviedo. We estimated the WTP of households from these two cities to protect sea turtle habitat to be between 42 and 57 per year for 5 years. Additionally, we attempted to assess the impact of the both the respondents' demographics and their perception toward various situations on their WTP value. Findings include a negative correlation between the age of a respondent and the probability of an individual willing to pay the hypothetical WTP amount. We found that WTP of an individual was not dependent on prior knowledge of the effects of SLR on sea turtle habitat. The greatest indicators of whether or not an individual was willing to pay to protect sea turtle habitat were the respondents' perception regarding the trustworthiness and efficiency of the party which will implement the conservation measures and their confidence in the conservation methods used. Respondents who perceive sea turtles having an effect on their life were also more likely to pay.
-
How Much Are Floridians Willing to Pay for Protecting Sea Turtles from Sea Level Rise?
Hamed, Ahmed; Madani, Kaveh; Von Holle, Betsy; Wright, James; Milon, J Walter; Bossick, Matthew
2016-01-01
Sea level rise (SLR) is posing a great inundation risk to coastal areas. Some coastal nesting species, including sea turtle species, have experienced diminished habitat from SLR. Contingent valuation method (CVM) was used in an effort to assess the economic loss impacts of SLR on sea turtle nesting habitats for Florida coasts; and to elicit values of willingness to pay (WTP) of Central Florida residents to implement certain mitigation strategies, which would protect Florida's east coast sea turtle nesting areas. Using the open-ended and dichotomous choice CVM, we sampled residents of two Florida communities: Cocoa Beach and Oviedo. We estimated the WTP of households from these two cities to protect sea turtle habitat to be between $42 and $57 per year for 5 years. Additionally, we attempted to assess the impact of the both the respondents' demographics and their perception toward various situations on their WTP value. Findings include a negative correlation between the age of a respondent and the probability of an individual willing to pay the hypothetical WTP amount. We found that WTP of an individual was not dependent on prior knowledge of the effects of SLR on sea turtle habitat. The greatest indicators of whether or not an individual was willing to pay to protect sea turtle habitat were the respondents' perception regarding the trustworthiness and efficiency of the party which will implement the conservation measures and their confidence in the conservation methods used. Respondents who perceive sea turtles having an effect on their life were also more likely to pay.
-
Aspects of fracture mechanics in cryogenic model design. Part 2: NTF materials
NASA Technical Reports Server (NTRS)
Newman, J. C., Jr.; Lisagor, W. B.
1983-01-01
Results of fatigue crack growth and fracture toughness tests conducted on three candidate materials are presented. Fatigue crack growth and fracture toughness tests were conducted on NITRONIC 40 at room temperature and -275 F. Fracture toughness tests were also conducted on Vascomax 200 and 250 maraging steel from room temperature to -320 F. NITRONIC 40 was used to make the Pathfinder 1 model. The fatigue crack growth rate tests were conducted at room temperature and -275 F on three-point notch bend specimens. The fracture toughness tests on the as received and stress relieved materials at -275 F were conducted on the center crack tension specimens. Toughness tests were also conducted on Vascomax CVM-200 and CVM-250 maraging steel from room temperature to -320 F using round and rectangular compact specimens.
-
Chen, Alex; McKinley, Scott A.; Shi, Feng; Wang, Simi; Mucha, Peter J.; Harit, Dimple; Forest, M. Gregory; Lai, Samuel K.
2015-01-01
Secretory immunoglobulin A (sIgA), a dimeric antibody found in high quantities in the gastrointestinal mucosa, is broadly associated with mucosal immune protection. A distinguishing feature of sIgA is its ability to crosslink pathogens, thereby creating pathogen/sIgA aggregates that are too large to traverse the dense matrix of mucin fibers in mucus layers overlying epithelial cells and consequently reducing infectivity. Here, we use modeling to investigate this mechanism of “immune exclusion” based on sIgA-mediated agglutination, in particular the potential use of sIgA to agglutinate HIV in cervicovaginal mucus (CVM) and prevent HIV transmission. Utilizing reported data on HIV diffusion in CVM and semen, we simulate HIV collision kinetics in physiologically-thick mucus layers–a necessary first step for sIgA-induced aggregation. We find that even at the median HIV load in semen of acutely infected individuals possessing high viral titers, over 99% of HIV virions will penetrate CVM and reach the vaginal epithelium without colliding with another virion. These findings imply that agglutination is unlikely to be the dominant mechanism of sIgA-mediated protection against HIV or other sexually transmitted pathogens. Rather, we surmise that agglutination is most effective against pathogens either present at exceedingly high concentrations or that possess motility mechanisms other than Brownian diffusion that significantly enhance encounter rates. PMID:26132216
-
Englar, Ryane E
Experiential learning through the use of standardized patients (SPs) is the primary way by which human medical schools teach clinical communication. The profession of veterinary medicine has followed suit in response to new graduates' and their employers' concerns that veterinary interpersonal skills are weak and unsatisfactory. As a result, standardized clients (SCs) are increasingly relied upon as invaluable teaching tools within veterinary curricula to advance relationship-centered care in the context of a clinical scenario. However, there is little to no uniformity in the approach that various colleges of veterinary medicine take when designing simulation-based education (SBE). A further complication is that programs with pre-conceived curricula must now make room for training in clinical communication. Curricular time constraints challenge veterinary colleges to individually decide how best to utilize SCs in what time is available. Because it is a new program, Midwestern University College of Veterinary Medicine (MWU CVM) has had the flexibility and the freedom to prioritize an innovative approach to SBE. The author discusses the SBE that is currently underway at MWU CVM, which incorporates 27 standardized client encounters over eight consecutive pre-clinical quarters. Prior to entering clinical rotations, MWU CVM students are exposed to a variety of simulation formats, species, clients, settings, presenting complaints, and communication tasks. These represent key learning opportunities for students to practice clinical communication, develop self-awareness, and strategize their approach to future clinical experiences.
-
Perinetti, Giuseppe; Caprioglio, Alberto; Contardo, Luca
2014-11-01
To evaluate the diagnostic accuracy and repeatability of the visual assessment of the cervical vertebral maturation (CVM) stages. Ten operators underwent training sessions in visual assessment of CVM staging. Subsequently, they were asked to stage 72 cases equally divided into the six stages. Such assessment was repeated twice in two sessions (T1 and T2) 4 weeks apart. A reference standard for each case was created according to a cephalometric analysis of both the concavities and shapes of the cervical vertebrae. The overall agreement with the reference standard was about 68% for both sessions and 76.9% for intrarater repeatability. The overall kappa coefficients with the reference standard were up to 0.86 for both sessions, and 0.88 for intrarater repeatability. Overall, disagreements one stage and twp stage apart were 23.5% (T1) and 5.1% (T2), respectively. Sensitivity ranged from 53.3% for CS5 (T1) to 99.9% for CS1 (T2), positive predictive values ranged from 52.4% for CS5 (T2) to 94.3% for CS6 (T1), and accuracy ranged from 83.6% for CS4 (T2) to 94.9% for CS1 (T1). Visual assessment of the CVM stages is accurate and repeatable to a satisfactory level. About one in three cases remain misclassified; disagreement is generally limited to one stage and is mostly seen in stages 4 and 5.
-
Sims, Lee B; Frieboes, Hermann B; Steinbach-Rankins, Jill M
2018-01-01
A variety of drug-delivery platforms have been employed to deliver therapeutic agents across cervicovaginal mucus (CVM) and the vaginal mucosa, offering the capability to increase the longevity and retention of active agents to treat infections of the female reproductive tract (FRT). Nanoparticles (NPs) have been shown to improve retention, diffusion, and cell-specific targeting via specific surface modifications, relative to other delivery platforms. In particular, polymeric NPs represent a promising option that has shown improved distribution through the CVM. These NPs are typically fabricated from nontoxic, non-inflammatory, US Food and Drug Administration-approved polymers that improve biocompatibility. This review summarizes recent experimental studies that have evaluated NP transport in the FRT, and highlights research areas that more thoroughly and efficiently inform polymeric NP design, including mathematical modeling. An overview of the in vitro, ex vivo, and in vivo NP studies conducted to date - whereby transport parameters are determined, extrapolated, and validated - is presented first. The impact of different NP design features on transport through the FRT is summarized, and gaps that exist due to the limitations of iterative experimentation alone are identified. The potential of mathematical modeling to complement the characterization and evaluation of diffusion and transport of delivery vehicles and active agents through the CVM and mucosa is discussed. Lastly, potential advancements combining experimental and mathematical knowledge are suggested to inform next-generation NP designs, such that infections in the FRT may be more effectively treated.
-
Yasunaga, Hideo; Ide, Hiroo; Imamura, Tomoaki; Ohe, Kazuhiko
2006-02-20
The application of Willingness To Pay (WTP) measurement with Contingent Valuation Method (CVM) to medical services is gradually increasing. Knowing what influences WTP is an important matter because validity of CVM in medical services remains controversial. The objective of this survey is to measure WTP for the treatment of typical acute illnesses and to analyze the factors affecting WTP. A questionnaire survey was conducted over the Internet, in which 795 men and women between 40 and 59 years old responded to questions about WTP for medical expenses in three hypothetical scenarios: common cold (CC), retinal detachment (RD) and myocardiac infarction (MI). Mean WTP was $29.9 for CC, $2,233 for RD, and $8,976 for MI. WTP for RD and MI was lower in the low-income group. While WTP for CC did not vary with income, WTP was higher in groups whose current subjective fitness levels were low. Although WTP measurements are criticized frequently for their validity and reliability, they are still useful for determining the economic value of medical services. Based on the results of this study, it is deemed necessary to enhance safety nets for low-income earners in regards to serious illnesses that incur high medical expenses. Further, it is recommended that the rate of co-payments be set relatively high with respect to mild illnesses for which alternative services are available.
-
Ticks and Lyme Disease: Symptoms, Treatment, and Prevention
... for ticks after outdoor activities. Lyme Disease in Dogs and Other Pets Household pets can get Lyme ... FDA’s Center for Veterinary Medicine (CVM) say that dogs with Lyme disease occasionally develop serious kidney disease ...
-
Hrabcová, Dana; Pásek, Michal; Šimurda, Jiří; Christé, Georges
2013-12-13
We have developed a computer model of human cardiac ventricular myocyte (CVM), including t-tubular and cleft spaces with the aim of evaluating the impact of accumulation-depletion of ions in restricted extracellular spaces on transmembrane ion transport and ionic homeostasis in human CVM. The model was based on available data from human CVMs. Under steady state, the effect of ion concentration changes in extracellular spaces on [Ca2+]i-transient was explored as a function of critical fractions of ion transporters in t-tubular membrane (not documented for human CVM). Depletion of Ca2+ and accumulation of K+ occurring in extracellular spaces slightly affected the transmembrane Ca2+ flux, but not the action potential duration (APD90). The [Ca2+]i-transient was reduced (by 2%-9%), depending on the stimulation frequency, the rate of ion exchange between t-tubules and clefts and fractions of ion-transfer proteins in the t-tubular membrane. Under non-steady state, the responses of the model to changes of stimulation frequency were analyzed. A sudden increase of frequency (1-2.5 Hz) caused a temporal decrease of [Ca2+] in both extracellular spaces, a reduction of [Ca2+]i-transient (by 15%) and APD90 (by 13 ms). The results reveal different effects of activity-related ion concentration changes in human cardiac t-tubules (steady-state effects) and intercellular clefts (transient effects) in the modulation of membrane ion transport and Ca2+ turnover.
-
Federal Register 2010, 2011, 2012, 2013, 2014
2013-08-02
... the full cost recovery of FDA reinspection or recall oversight could impose severe economic hardship... Safety and Applied Nutrition (CFSAN) and the Center for Veterinary Medicine (CVM). Thus, as the starting...
-
SCEC UCVM - Unified California Velocity Model
NASA Astrophysics Data System (ADS)
Small, P.; Maechling, P. J.; Jordan, T. H.; Ely, G. P.; Taborda, R.
2011-12-01
The SCEC Unified California Velocity Model (UCVM) is a software framework for a state-wide California velocity model. UCVM provides researchers with two new capabilities: (1) the ability to query Vp, Vs, and density from any standard regional California velocity model through a uniform interface, and (2) the ability to combine multiple velocity models into a single state-wide model. These features are crucial in order to support large-scale ground motion simulations and to facilitate improvements in the underlying velocity models. UCVM provides integrated support for the following standard velocity models: SCEC CVM-H, SCEC CVM-S and the CVM-SI variant, USGS Bay Area (cencalvm), Lin-Thurber Statewide, and other smaller regional models. New models may be easily incorporated as they become available. Two query interfaces are provided: a Linux command line program, and a C application programming interface (API). The C API query interface is simple, fully independent of any specific model, and MPI-friendly. Input coordinates are geographic longitude/latitude and the vertical coordinate may be either depth or elevation. Output parameters include Vp, Vs, and density along with the identity of the model from which these material properties were obtained. In addition to access to the standard models, UCVM also includes a high resolution statewide digital elevation model, Vs30 map, and an optional near-surface geo-technical layer (GTL) based on Ely's Vs30-derived GTL. The elevation and Vs30 information is bundled along with the returned Vp,Vs velocities and density, so that all relevant information is retrieved with a single query. When the GTL is enabled, it is blended with the underlying crustal velocity models along a configurable transition depth range with an interpolation function. Multiple, possibly overlapping, regional velocity models may be combined together into a single state-wide model. This is accomplished by tiling the regional models on top of one another in three dimensions in a researcher-specified order. No reconciliation is performed within overlapping model regions, although a post-processing tool is provided to perform a simple numerical smoothing. Lastly, a 3D region from a combined model may be extracted and exported into a CVM-Etree. This etree may then be queried by UCVM much like a standard velocity model but with less overhead and generally better performance due to the efficiency of the etree data structure.
-
Brocal, Josep; De Decker, Steven; José-López, Roberto; Guevar, Julien; Ortega, Maria; Parkin, Tim; Ter Haar, Gert; Gutierrez-Quintana, Rodrigo
2018-05-19
Congenital vertebral malformations (CVM) are common in brachycephalic 'screw-tailed' dogs; they can be associated with neurological deficits and a genetic predisposition has been suggested. The purpose of this study was to evaluate radiography as a screening method for congenital thoracic vertebral malformations in brachycephalic 'screw-tailed' dogs by comparing it with CT. Forty-nine dogs that had both radiographic and CT evaluations of the thoracic vertebral column were included. Three observers retrospectively reviewed the images independently to detect CVMs. When identified, they were classified according to a previously published radiographic classification scheme. A CT consensus was then reached. All observers identified significantly more affected vertebrae when evaluating orthogonal radiographic views compared with lateral views alone; and more affected vertebrae with the CT consensus compared with orthogonal radiographic views. Given the high number of CVMs per dog, the number of dogs classified as being CVM free was not significantly different between CT and radiography. Significantly more midline closure defects were also identified with CT compared with radiography. Malformations classified as symmetrical or ventral hypoplasias on radiography were frequently classified as ventral and medial aplasias on CT images. Our results support that CT is better than radiography for the classification of CVMs and this will be important when further evidence of which are the most clinically relevant CVMs is identified. These findings are of particular importance for designing screening schemes of CVMs that could help selective breeding programmes based on phenotype and future studies. © British Veterinary Association (unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
-
Gupta, Shreya; Deoskar, Anuradha; Gupta, Puneet; Jain, Sandhya
2015-01-01
OBJECTIVE: The aim of this cross sectional study was to assess serum insulin-like growth factor-1 (IGF-1) levels in female and male subjects at various cervical vertebral maturation (CVM) stages. MATERIAL AND METHODS: The study sample consisted of 60 subjects, 30 females and 30 males, in the age range of 8-23 years. For all subjects, serum IGF-1 level was estimated from blood samples by means of chemiluminescence immunoassay (CLIA). CVM was assessed on lateral cephalograms using the method described by Baccetti. Serum IGF-1 level and cervical staging data of 30 female subjects were included and taken from records of a previous study. Data were analyzed by Kruska-Wallis and Mann Whitney test. Bonferroni correction was carried out and alpha value was set at 0.003. RESULTS: Peak value of serum IGF-1 was observed in cervical stages CS3 in females and CS4 in males. Differences between males and females were observed in mean values of IGF-1 at stages CS3, 4 and 5. The highest mean IGF-1 levels in males was observed in CS4 followed by CS5 and third highest in CS3; whereas in females the highest mean IGF-1 levelswas observed in CS3 followed by CS4 and third highest in CS5. Trends of IGF-1 in relation to the cervical stages also differed between males and females. The greatest mean serum IGF-1 value for both sexes was comparable, for females (397 ng/ml) values were slightly higher than in males (394.8 ng/ml). CONCLUSIONS: Males and females showed differences in IGF-1 trends and levels at different cervical stages. PMID:25992990
-
Chen, Wendy Y; Hua, Junyi
2015-05-15
Protest response is a common aspect of contingent valuation (CV) studies, which has attracted growing attention from scholars worldwide. Distrust of government, understood as one of the major reasons for protest response, has been prevalent across transitional China experiencing dramatic changes in its economy, society and natural environment. Citizen distrust of government would significantly hinder the efficiency and validity of the contingent valuation method (CVM) application focusing on the provision of public environmental and ecological goods in China, as a large proportion of protest responses might be induced. Hitherto little has been done to link residents' trust in government to their environmental behaviors in developing and transitional economies like China where CVM has been increasingly applied to generate meaningful and reliable information for integrating both ecological and socioeconomic perspectives into policy decisions. This study aims to investigate the discrepancies between protest responses induced by distrust of government and non-protest responses, using the contingent valuation of heritage trees in Guangzhou as a case. The combination of a set of debriefing questions and several attitudinal questions is employed in the questionnaire. Based on logit analysis and discriminant analysis, it has been found that protestors who distrust government and non-protestors share similar salient values associated with urban heritage trees in Guangzhou, especially their distinctive historical and cultural values, in comparison with ordinary urban trees. Residents with low familiarity with heritage trees (who rarely visit sites with heritage trees, know little about management and conservation techniques, and consider present management to be ineffective) are likely to act as protesters with the "distrust of government" belief. Only if more opportunities are provided for residents to obtain access to urban heritage tree sites, more information (about urban heritage trees and other environmental and ecological goods) is disseminated, and more effective management is implemented, can better governmental trust be developed and stronger public participation and support secured. The results of this study can shed light on understanding protest responses in CV studies and improving the reliability and efficiency of CVM in China and other developing countries where a low level of trust in government prevails. Copyright © 2015 Elsevier Ltd. All rights reserved.
-
NASA Astrophysics Data System (ADS)
Souza, Wanderley De Jesus; Rodrigues Sinobas, Leonor; Sánchez, Raúl; Arriel Botrel, Tarlei; Duarte Coelho, Rubens
2013-04-01
Root and soil intrusion into the conventional emitters is one of the major disadvantages to obtain a good uniformity of water application in subsurface drip irrigation (SDI). In the last years, there have been different approaches to reduce these problems such as the impregnation of emitters with herbicide, and the search for an emitter geometry impairing the intrusion of small roots. Within the last this study, has developed and evaluated an emitter model which geometry shows specific physical features to prevent emitter clogging. This work was developed at the Biosystems Engineering Department at ESALQ-USP/Brazil, and it is a part of a research in which an innovated emitteŕs model for SDI has been developed to prevent root and soil particles intrusion. An emitter with a mechanical-hydraulic mechanism (opening and closing the water outlet) for SDI was developed and manufactured using a mechanical lathe process. It was composed by a silicon elastic membrane a polyethylene tube and a Vnyl Polychloride membrane protector system. In this study the performance of the developed prototype was assessed in the laboratory and in the field conditions. In the laboratory, uniformity of water application was calculated by the water emission uniformity coefficient (CUE), and the manufacturer's coefficient of variation (CVm). In addition, variation in the membrane diameter submitted to internal pressures; head losses along the membrane, using the energy equation; and, precision and accuracy of the equation model, analyzed by Pearson's correlation coefficient (r), and by Willmott's concordance index (d) were also calculated with samples of the developed emitters. In the field, the emitters were installed in pots with and without sugar cane culture from October 2010 to January 2012. During this time, flow rate in 20 emitters were measured periodically, and the aspects of them about clogging at the end of the experiment. Emitters flow rates were measured quarterly to calculate: relative flow rate (QR); flow disturbance (FD); CUE; and, variation coefficient of relative flow (CVQR). In the laboratory, both "CVm" and "CUE" were small since emitters were manufactured manually, the manufacturing variation was higher than in processed emitters. Variation in the membrane diameter decreased 1/4.5 from the central toward to the emitter end; and, the head loss increased. Estimated pressures were in good agreement to the observed ones with r and d values of 0.95, and 0.85, respectively. In the field tests, coefficients CVQR and QR were variable showing a poor classification according with ABNT (1986) and Solomon (1984). FD values were ranged between 11 and 24%and there was no observed clogging by roots and/or soil intrusion at the end of the experiment. On the other hand, emitter's flows were close to the average, indicating that water application kept according to the initial results. This study shows the suitability of this emitter model to prevent root and soil intrusion within the research conditions however further studies would be needed assessing the membrane performance, emitter physical characteristics, and control of emitter flow rate in order to develop the final prototype.
-
Bioavailability of catechins from tea: the effect of milk.
van het Hof, K H; Kivits, G A; Weststrate, J A; Tijburg, L B
1998-05-01
To assess the blood concentration of catechins following green or black tea ingestion and the effect of addition of milk to black tea. Twelve volunteers received a single dose of green tea, black tea and black tea with milk in a randomized cross-over design with one-week intervals. Blood samples were drawn before and up to eight hours after tea consumption. The study was performed at the Unilever Research Vlaardingen in The Netherlands. Twelve healthy adult volunteers (7 females, 5 males) participated in the study. They were recruited among employees of Unilever Research Vlaardingen. Green tea, black tea and black tea with semi-skimmed milk (3 g tea solids each). Consumption of green tea (0.9 g total catechins) or black tea (0.3 g total catechins) resulted in a rapid increase of catechin levels in blood with an average maximum change from baseline (CVM) of 0.46 micromol/l (13%) after ingestion of green tea and 0.10 micromol/l (13%) in case of black tea. These maximum changes were reached after (mean (s.e.m.)) t=2.3 h (0.2) and t=2.2 h (0.2) for green and black tea respectively. Blood levels rapidly declined with an elimination rate (mean (CVM)) of t1/2=4.8 h (5%) for green tea and t1/2=6.9 h (8%) for black tea. Addition of milk to black tea (100 ml in 600 ml) did not significantly affect the blood catechin levels (areas under the curves (mean (CVM) of 0.53 h. micromol/l (11%) vs 0.60 h. micromol/l (9%) for black tea and black tea with milk respectively. Catechins from green tea and black tea are rapidly absorbed and milk does not impair the bioavailability of tea catechins.
-
NASA Astrophysics Data System (ADS)
Oscandar, Fahmi; Malinda, Yuti; Azhari, H.; Murniati, Nani; Yeh Ong, Sing; Subiyanto; Supian, Sudradjat
2018-01-01
In this paper, Cervical Vertebral Maturation method was used to assess the mandibular growth in Deutero-Malay sub race. Twenty eight laterals Cephalometric radiographs of Deutero-Malay sub race aged 9-15 were observed. The observation used stratified random sampling by measuring the quantitative and qualitative assessment of the 2nd through 4th cervical vertebra of the subjects. It produced the diagram of developmental stages of cervical vertebrae for Deutero-Malay sub race. The diagram can be used to determine mandibular growth in term of qualitative by matching the shape of cervical vertebrae. It was obtained that the Cervical Vertebral Maturation method can be used to assess mandibular growth in Deutero-Malay sub race by matching the shape of cervical vertebrae to the diagram of developmental stages of cervical vertebrae. In addition, Cervical Vertebral Maturation method can be used to identification person’s age.
-
Schmidt, Peggy L; Trevejo, Rosalie T; Tkalcic, Suzana
2008-01-01
As detailed in the Association of Schools of Public Health / Association of American Veterinary Medical Colleges 2007 Joint Symposium on Veterinary Public Health, veterinary public health (VPH) can no longer be viewed as a unique sub-specialty of veterinary medicine. Rather, its practice pervades nearly every aspect of the veterinary profession, regardless of whether the practitioner is engaged in small-animal, large-animal, research, corporate, or military practice. In congruence with the practice of VPH, the teaching of VPH should also pervade nearly every aspect of veterinary education. Accordingly, at Western University of Health Sciences, College of Veterinary Medicine (WU-CVM), public health is not simply taught as an individual course but, rather, is interwoven into almost every aspect of the curriculum, continually emphasizing the relevance of this discipline to the practice of veterinary medicine. This article outlines the teaching philosophy of WU-CVM, provides an overview of the curriculum, and describes the integral nature of public health throughout all four years of the educational program.
-
Exploring the use of tablet PCs in veterinary medical education: opportunity or obstacle?
Wang, Hong; Rush, Bonnie R; Wilkerson, Melinda; van der Merwe, Deon
2014-01-01
A tablet PC is a laptop computer with a touch screen and a digital pen or stylus that can be used for handwritten notes and drawings. The use of tablet PCs has been investigated in many disciplines such as engineering, mathematics, science, and education. The purpose of this article is to explore student and faculty attitudes toward and experiences with tablet PCs 6 years after the implementation of a tablet PC program in the College of Veterinary Medicine (CVM) at Kansas State University (K-State). This study reports that the use of tablet PCs has enhanced students' learning experiences through learner-interface interaction, learner-content interaction, learner-instructor interaction, and learner-learner interaction. This study also identifies digital distraction as the major negative experience with tablet PCs during class time. The tablet PC program provides CVM faculty the potential to pursue technology integration strategies that support expected learning outcomes and provides students the potential to develop self-monitoring and self-discipline skills that support learning with digital technologies.
-
Perinetti, Giuseppe; Contardo, Luca; Castaldo, Attilio; McNamara, James A; Franchi, Lorenzo
2016-07-01
To evaluate the capability of both cervical vertebral maturation (CVM) stages 3 and 4 (CS3-4 interval) and the peak in standing height to identify the mandibular growth spurt throughout diagnostic reliability analysis. A previous longitudinal data set derived from 24 untreated growing subjects (15 females and nine males,) detailed elsewhere were reanalyzed. Mandibular growth was defined as annual increments in Condylion (Co)-Gnathion (Gn) (total mandibular length) and Co-Gonion Intersection (Goi) (ramus height) and their arithmetic mean (mean mandibular growth [mMG]). Subsequently, individual annual increments in standing height, Co-Gn, Co-Goi, and mMG were arranged according to annual age intervals, with the first and last intervals defined as 7-8 years and 15-16 years, respectively. An analysis was performed to establish the diagnostic reliability of the CS3-4 interval or the peak in standing height in the identification of the maximum individual increments of each Co-Gn, Co-Goi, and mMG measurement at each annual age interval. CS3-4 and standing height peak show similar but variable accuracy across annual age intervals, registering values between 0.61 (standing height peak, Co-Gn) and 0.95 (standing height peak and CS3-4, mMG). Generally, satisfactory diagnostic reliability was seen when the mandibular growth spurt was identified on the basis of the Co-Goi and mMG increments. Both CVM interval CS3-4 and peak in standing height may be used in routine clinical practice to enhance efficiency of treatments requiring identification of the mandibular growth spurt.
-
Chen, Wendy Y; Aertsens, Joris; Liekens, Inge; Broekx, Steven; De Nocker, Leo
2014-08-01
The strategic importance of ecosystem service valuation as an operational basis for policy decisions on natural restoration has been increasingly recognized in order to align the provision of ecosystem services with the expectation of human society. The contingent valuation method (CVM) is widely used to quantify various ecosystem services. However, two areas of concern arise: (1) whether people value specific functional ecosystem services and overlook some intrinsic aspects of natural restoration, and (2) whether people understand the temporal dimension of ecosystem services and payment schedules given in the contingent scenarios. Using a peri-urban riparian meadow restoration project in Flanders, Belgium as a case, we explored the impacts of residents' perceived importance of various ecosystem services and stated financial constraints on their willingness-to-pay for the proposed restoration project employing the CVM. The results indicated that people tended to value all the benefits of riparian ecosystem restoration concurrently, although they accorded different importances to each individual category of ecosystem services. A longer payment scheme can help the respondents to think more about the flow of ecosystem services into future generations. A weak temporal embedding effect can be detected, which might be attributed to respondents' concern about current financial constraints, rather than financial bindings associated with their income and perceived future financial constraints. This demonstrates the multidimensionality of respondents' financial concerns in CV. This study sheds light on refining future CV studies, especially with regard to public expectation of ecosystem services and the temporal dimension of ecosystem services and payment schedules.
-
NASA Astrophysics Data System (ADS)
Chen, Wendy Y.; Aertsens, Joris; Liekens, Inge; Broekx, Steven; De Nocker, Leo
2014-08-01
The strategic importance of ecosystem service valuation as an operational basis for policy decisions on natural restoration has been increasingly recognized in order to align the provision of ecosystem services with the expectation of human society. The contingent valuation method (CVM) is widely used to quantify various ecosystem services. However, two areas of concern arise: (1) whether people value specific functional ecosystem services and overlook some intrinsic aspects of natural restoration, and (2) whether people understand the temporal dimension of ecosystem services and payment schedules given in the contingent scenarios. Using a peri-urban riparian meadow restoration project in Flanders, Belgium as a case, we explored the impacts of residents' perceived importance of various ecosystem services and stated financial constraints on their willingness-to-pay for the proposed restoration project employing the CVM. The results indicated that people tended to value all the benefits of riparian ecosystem restoration concurrently, although they accorded different importances to each individual category of ecosystem services. A longer payment scheme can help the respondents to think more about the flow of ecosystem services into future generations. A weak temporal embedding effect can be detected, which might be attributed to respondents' concern about current financial constraints, rather than financial bindings associated with their income and perceived future financial constraints. This demonstrates the multidimensionality of respondents' financial concerns in CV. This study sheds light on refining future CV studies, especially with regard to public expectation of ecosystem services and the temporal dimension of ecosystem services and payment schedules.
-
Federal Register 2010, 2011, 2012, 2013, 2014
2010-02-05
... Center for Veterinary Medicine AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The... purposes in electronic format to the Center for Veterinary Medicine (CVM). DATES: Submit written or... Intent to Slaughter for Human Food Purposes in Electronic Format to the Center for Veterinary Medicine...
-
USDA-ARS?s Scientific Manuscript database
We report draft genomes of Salmonella enterica subsp. enterica Serovar Cubana strain CVM42234 isolated from chick feed in 2012 and Salmonella Cubana strain 76814 isolated from swine in 2004. The genome sizes are 4,975,046 and 4,936,251 base pairs, respectively....
-
Developmental Exposure to a Thyroid Disrupting Chemical Stimulates Phagocytosis in Juvenile Sprague-Dawley Rats.
AA Rooney1, R Matulka2, and R Luebke3. 1NCSU/US EPA CVM, Department of Anatomy, Physiological Sciences and Radiology, Raleigh, NC;2UNC Department of Toxicology, Cha... -
Economic Valuation of Air Force Environmental Resources: A Contingent Valuation Case Study.
1996-12-01
Empirical Measures of Welfare Change: A Comparison of Non-market Techniques," Land Economics: 156-175 (Vol. 61, No. 2, 1985). Sen , Amartya K...shackles of the traditional [observed] approach" ( Sen , 1977). The flexibility of a properly designed contingent valuation study allows CVM to measure
-
Federal Register 2010, 2011, 2012, 2013, 2014
2010-05-05
...] Guidance for Industry on Documenting Statistical Analysis Programs and Data Files; Availability AGENCY... Programs and Data Files.'' This guidance is provided to inform study statisticians of recommendations for documenting statistical analyses and data files submitted to the Center for Veterinary Medicine (CVM) for the...
-
Federal Register 2010, 2011, 2012, 2013, 2014
2010-02-05
... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2010-D-0043... Center for Veterinary Medicine AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The... format to the Center for Veterinary Medicine (CVM). DATES: Submit written or electronic comments on the...
-
Federal Register 2010, 2011, 2012, 2013, 2014
2013-08-30
... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2013-N-0519... Veterinary Medicine Using the Food and Drug Administration Electronic Submission Gateway AGENCY: Food and... Center for Veterinary Medicine (CVM) accepts certain types of submissions electronically with no...
-
Federal Register 2010, 2011, 2012, 2013, 2014
2010-02-05
... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2010-N-0057... How to Submit Information in Electronic Format to the Center for Veterinary Medicine Using the Food... on the reporting requirements for the Center for Veterinary Medicine's (CVM's) ``Guidance for...
-
Prasad, Mandava; Ganji, Venkata Suresh Kumar; George, Suja Ani; Talapaneni, Ashok Kumar; Shetty, Sharath Kumar
2013-01-01
Objective: Evaluation of skeletal maturity in human individuals is an important aspect in orthodontics and dentofacial orthopedics because, growth guidance and fundamental structural changes are essential for treatment of skeletal discrepancies in all the three planes. Among various growth assessment methods, cervical vertebra maturation stages and hand wrist have been correlated with the individual growth changes during puberty. The purpose of this study is to determine correlation of the CVM index with the modified median phalanx index (MP3) as described by Rajagopal and Kansal. Materials and Methods: 200 subjects (100 males and 100 females) of Nellore, Indian origin boys aged between 10 to 19 years and girls of 8 to 16 years were selected for the study. The subjects are selected randomly from patients visiting the Departments of Orthodontics and Dentofacial Orthopedics, Pediatric dentistry and Oral medicine and Radiology at Narayana Dental College and Hospital. Nellore. Radiographs of left hand MP3 and lateral cephalogram were taken. Results: Cohen's kappa statistic was used to assess the agreement between the two measurements based on categorical variables. Conclusions: There was a good concordance between 6 stages of CVMI (Hassel and Farman) and the 6 stages of MP3 (Rajagopal and Kansal). Physiological maturity was earlier in females than in males when compared to the individuals of opposite sex of same chronological age. Chronological age was not a valid predictor of assessing the skeletal maturity because of significant variations in the distribution of CVMI and MP3 stages with respect to individual chronological age distribution. PMID:23633839
-
Mucus-penetrating nanoparticles for vaginal and gastrointestinal drug delivery
NASA Astrophysics Data System (ADS)
Ensign-Hodges, Laura
A method that could provide more uniform and longer-lasting drug delivery to mucosal surfaces holds the potential to greatly improve the effectiveness of prophylactic and therapeutic approaches for numerous diseases and conditions, including sexually transmitted infections and inflammatory bowel disease. However, the body's natural defenses, including adhesive, rapidly cleared mucus linings coating nearly all entry points to the body not covered by skin, has limited the effectiveness of drug and gene delivery by nanoscale delivery systems. Here, we investigate the use of muco-inert mucus-penetrating nanoparticles (MPP) for improving vaginal and gastrointestinal drug delivery. Conventional hydrophobic nanoparticles strongly adhere to mucus, facilitating rapid clearance from the body. Here, we demonstrate that mucoadhesive polystyrene nanoparticles (conventional nanoparticles, CP) become mucus-penetrating in human cervicovaginal mucus (CVM) after pretreatment with sufficient concentrations of Pluronic F127. Importantly, the diffusion rate of large MPP did not change in F127 pretreated CVM, implying there is no affect on the native pore structure of CVM. Additionally, there was no increase in inflammatory cytokine release in the vaginal tract of mice after daily application of 1% F127 for one week. Importantly, HSV virus remains adherent in F127-pretreated CVM. Mucosal epithelia use osmotic gradients for fluid absorption and secretion. We hypothesized that hypotonically-induced fluid uptake could be advantageous for rapidly delivering drugs through mucus to the vaginal epithelium. We evaluated hypotonic formulations for delivering water-soluble drugs and for drug delivery with MPP. Hypotonic formulations markedly increased the rate at which drugs and MPP reached the epithelial surface. Additionally, hypotonic formulations greatly enhanced drug and MPP delivery to the entire epithelial surface, including deep into the vaginal folds (rugae) that isotonic formulations failed to reach. However, hypotonic formulations caused free drugs to be drawn through the epithelium, reducing vaginal retention. In contrast, hypotonic formulations caused MPP to accumulate rapidly and uniformly on vaginal surfaces, ideally positioned for sustained drug delivery. Using a mouse model of vaginal genital herpes (HSV-2) infection, we found that hypotonic delivery of free drug led to improved immediate protection, but diminished longer-term protection. Minimally hypotonic formulations provided rapid and uniform delivery of MPP to the entire vaginal surface, thus enabling formulations with minimal risk of epithelial toxicity. We then describe an ex vivo method for characterizing particle transport on freshly excised mucosal tissues. By directly observing MPP transport on vaginal, gastrointestinal, and respiratory tissue, we were able to determine an innate difference in mucus mesh size at different anatomical locations. In addition, we were able to optimize particle size for gastrointestinal delivery in mice. As described here, there are numerous barriers to effective drug delivery in the gastrointestinal tract, including the mucus barrier. We go on to demonstrate that MPP can improve delivery in the gastrointestinal tract, both by rectal and oral administration. Finally, we describe the use of MPP for improving vaginal drug delivery. Incomplete drug coverage and short duration of action limit the effectiveness of vaginally administered drugs, including microbicides for preventing sexually transmitted infections. We show that MPP provide uniform distribution over the vaginal epithelium, whereas CP are aggregated by mouse vaginal mucus, leading to poor distribution. By penetrating into the deepest mucus layers in the rugae, more MPP were retained in the vaginal tract compared to CP. After 24 h, when delivered in a conventional vaginal gel, patches of a model drug remained on the vaginal epithelium, whereas the epithelium was coated with drug delivered by MPP. We then demonstrate that when administered 30 min prior to inoculum, anti-HSV-2 MPP protected 53% of mice compared to only 16% protected by soluble drug. Overall, MPP improved vaginal drug distribution and retention, provided more effective protection against vaginal viral challenge than soluble drug, and were non-toxic when administered daily for one week.
-
PERINATAL EXPOSURE TO ATRAZINE SUPPRESSES JUVENILE IMMUNE FUNCTION IN MALE, BUT NOT FEMALE SPRAGUE-DAWLEY RATS. AA Rooney1 and RW Luebke2. 1NCSU/USEPA CVM, Department of Anatomy, Physiological Sciences, and Radiology, Raleigh, NC;2USEPA, NHEERL, RTP, NC.
The ability of the ... -
Federal Register 2010, 2011, 2012, 2013, 2014
2010-04-30
... Electronic Format to the Center for Veterinary Medicine AGENCY: Food and Drug Administration, HHS. ACTION... Intent to Slaughter for Human Food Purposes in Electronic Format to The Center for Veterinary Medicine... Medicine (CVM) issues to a new animal drug sponsor (sponsor) a slaughter authorization letter that sets the...
-
Federal Register 2010, 2011, 2012, 2013, 2014
2011-02-03
...] Draft Guidance for Industry on ``Target Animal Safety and Effectiveness Protocol Development and...) entitled ``Target Animal Safety and Effectiveness Protocol Development and Submission.'' The purpose of... Center for Veterinary Medicine (CVM), Office of New Animal Drug Evaluation (ONADE), to reduce the time to...
-
Federal Register 2010, 2011, 2012, 2013, 2014
2010-02-18
... How to Submit a Protocol Without Data in Electronic Format to the Center for Veterinary Medicine... a Protocol Without Data in Electronic Format to the Center for Veterinary Medicine''--21 CFR 58.120... the animal drug sponsors, the Center for Veterinary Medicine (CVM) reviews protocols for safety and...
-
Depletion of penicillin G residues in sows after intramuscular injection
USDA-ARS?s Scientific Manuscript database
The US-FDA CVM has not established a tolerance for penicillin residues in swine tissues, but across much of Europe and Asia a tolerance of 50 ppb penicillin G is in effect. In the US, heavy sows are often treated with extra-label doses of penicillin G, however appropriate pre-slaughter withdrawal p...
-
Yamaguchi, Hiroyuki; Takezawa, Toshiaki
2018-05-29
A collagen vitrigel membrane (CVM) we developed can function as both a scaffold for cells and a pathway for chemicals. To extrapolate the corneal permeability of chemicals in vivo, we proposed six corneal models using the CVM. Thin and thick CVMs were utilized as models for Bowman's membrane (BM) and an acellular-stroma (AS), respectively. Models for a corneal epithelium (CEpi), a corneal epithelium-acellular stroma (CEpi-AS), a corneal epithelium-endothelium (CEpi-Endo) and a corneal epithelium-acellular stroma-endothelium (CEpi-AS-Endo) were fabricated by culturing corneal epithelial cells and/or corneal endothelial cells on the surface of CVMs. Subsequently, the permeability coefficient (P app ) value of each model was calculated using five chemicals with different molecular radii; cyanocobalamin and four FITC-dextrans (FD-4, FD-10, FD-20 and FD-40). The slopes of P app versus molecular radii of those chemicals in the both BM and AS models were almost similar to data using an excised rabbit corneal stroma. The ratios of P app values in models for BM, CEpi and CEpi-Endo against those in data using an excised rabbit cornea were calculated as 75.4, 6.4 and 4.5-folds for FD-4 and 38.7, 10.0 and 4.2-folds for FD-10, respectively. Similarly, those in models for AS, CEpi-AS and CEpi-AS-Endo were calculated as 26.1, 2.5 and 0.6-folds for FD-4 and 26.1, 1.5 and 0.6-folds for FD-10, respectively. These results suggest that the CEpi-AS-Endo model with both the barrier function of corneal cell layers and the diffusion capacity of chemicals in thick CVM is most appropriate for extrapolating the corneal permeability of chemicals in vivo . The American Society for Pharmacology and Experimental Therapeutics.
-
Serum IGF-1, IGFBP-3 and their ratio: Potential biochemical growth maturity indicators.
Jain, Nimisha; Tripathi, Tulika; Gupta, S K; Rai, Priyank; Kanase, Anup; Kalra, Shilpa
2017-12-01
Determination of skeletal maturation and remaining growth potential is an essential part of treatment planning in orthodontics. The aim of our study was to determine the relationship between IGF-1 levels, IGFBP-3 levels with CVM staging to track the pre pubertal and pubertal growth spurts in female patients in North Indian population. This cross-sectional study was conducted on ninety female subjects in the age group of 8-20 years. Blood samples were collected and centrifuged and serum samples were then analysed by Human IGF-1 and IGFBP-3 enzyme-linked immunosorbent assay kits, specific for IGF-1 and IGFBP-3, respectively. CVM staging on lateral cephalometric radiograph was determined for all patients. Analysis of variance test followed by a post hoc test was used to compare mean IGF-1 and IGFBP-3 corresponding to six stages of cervical vertebrae maturation stages. Linear Pearson's correlations were performed to determine the trends of IGF-1, IGFBP-3, and its ratio relating to CVM stage. The kappa statistic was used to measure inter and intra examiner reliability. P value <0.05 was considered as statistically significant. Mean serum IGF-1 levels were found to be highest (403.3 ± 12.3 ng/ml) at CVMI3 stage of CVMI. The post-hoc test revealed a significant difference in IGF-1 levels between all stages of CVMI, thereby indicating a specific range of IGF-1 levels for a specific skeletal stage. Mean serum IGFBP-3 levels were found to be highest (5186.8 ± 1384.2 ng/ml) at CVMI4 stage of CVMI. The mean serum IGFBP-3 levels at CVMI4 were found to be significantly higher than the levels at all other CVMI stages except CVMI3 stage. IGF-1 and IGFBP-3 can serve as a potential biochemical indicator for assessment of skeletal maturity.
-
Gupta, Shreya; Deoskar, Anuradha; Gupta, Puneet; Jain, Sandhya
2015-01-01
The aim of this cross sectional study was to assess serum insulin-like growth factor-1 (IGF-1) levels in female and male subjects at various cervical vertebral maturation (CVM) stages. The study sample consisted of 60 subjects, 30 females and 30 males, in the age range of 8-23 years. For all subjects, serum IGF-1 level was estimated from blood samples by means of chemiluminescence immunoassay (CLIA). CVM was assessed on lateral cephalograms using the method described by Baccetti. Serum IGF-1 level and cervical staging data of 30 female subjects were included and taken from records of a previous study. Data were analyzed by Kruska-Wallis and Mann Whitney test. Bonferroni correction was carried out and alpha value was set at 0.003. Peak value of serum IGF-1 was observed in cervical stages CS3 in females and CS4 in males. Differences between males and females were observed in mean values of IGF-1 at stages CS3, 4 and 5. The highest mean IGF-1 levels in males was observed in CS4 followed by CS5 and third highest in CS3; whereas in females the highest mean IGF-1 levelswas observed in CS3 followed by CS4 and third highest in CS5. Trends of IGF-1 in relation to the cervical stages also differed between males and females. The greatest mean serum IGF-1 value for both sexes was comparable, for females (397 ng/ml) values were slightly higher than in males (394.8 ng/ml). Males and females showed differences in IGF-1 trends and levels at different cervical stages.
-
ASSESSING THE ALLERGIC POTENTIAL OF INDOOR AIR FUNGAL CONTAMINANTS
Assessing the Allergic Potential of Indoor Air Fungal Contaminants
Marsha D W Ward1, Michael E Viana2, Yonjoo Chung3, Najwa Haykal-Coates1, Lisa B Copeland1, Steven H Gavett1, and MaryJane K Selgrade1. 1US EPA, ORD, NHEERL, RTP, NC, USA. 2NCSU, CVM, Raleigh, NC, USA, 3 UNC, S... -
ASSESSING ALLERGENICITY OF INDOOR AIR FUNGAL CONTAMINANTS
Assessing Allergenicity of Indoor Air Fungal Contaminants
M D W Ward1, M E Viana2, N Haykal-Coates1, L B Copeland1, S H Gavett1, and MJ K Selgrade1. 1US EPA, ORD, NHEERL, RTP, NC, USA. 2NCSU, CVM, Raleigh, NC, USA.
Rationale: The indoor environment has increased in impor... -
THE ALLERGENIC POTENTIAL OF INDOOR AIR FUNGAL CONTAMINANTS
The Allergenic Potential of Indoor Air Fungal Contaminants
Marsha D W Ward1, Michael E Viana2, Yongjoo Chung3, Najwa Haykal-Coates1, Lisa B Copeland1, Steven H Gavett1, and MaryJane K Selgrade1. 1US EPA, ORD, NHEERL, RTP, NC, USA. 2NCSU, CVM, Raleigh, NC, USA, 3 UNC, SPH,... -
ASSESSMENT OF IMMUNE RESPONSES TO PENICILLIUM CHRYSOGENUM AND CHARACTERIZATION OF ITS ALLERGENS
Assessment of immune responses to Penicillium chrysogenum and characterization of its allergens
Yongjoo Chung1, Michael E Viana2, Lisa B Copeland3, and MaryJane K Selgrade3, Marsha D W Ward3. 1 UNC, SPH, Chapel Hill, NC, 2NCSU, CVM, Raleigh, NC, 3US EPA, ORD, NHEERL, RTP,...
-
Autosomal Dominant Polycystic Kidney Disease (ADPKD) is one of the worlds most common life threatening genetic diseases. Over 95 percent of diagnosed...several genetic models to induce mutations: two during embryogenesis (with Six2-cre and CVM-cre) and one in the adult (Villin-cre). One of the embryonic
-
Concepts and applications for influenza antigenic cartography
Cai, Zhipeng; Zhang, Tong; Wan, Xiu-Feng
2011-01-01
Influenza antigenic cartography projects influenza antigens into a two or three dimensional map based on immunological datasets, such as hemagglutination inhibition and microneutralization assays. A robust antigenic cartography can facilitate influenza vaccine strain selection since the antigenic map can simplify data interpretation through intuitive antigenic map. However, antigenic cartography construction is not trivial due to the challenging features embedded in the immunological data, such as data incompleteness, high noises, and low reactors. To overcome these challenges, we developed a computational method, temporal Matrix Completion-Multidimensional Scaling (MC-MDS), by adapting the low rank MC concept from the movie recommendation system in Netflix and the MDS method from geographic cartography construction. The application on H3N2 and 2009 pandemic H1N1 influenza A viruses demonstrates that temporal MC-MDS is effective and efficient in constructing influenza antigenic cartography. The web sever is available at http://sysbio.cvm.msstate.edu/AntigenMap. PMID:21761589
-
Usha, K; Baskaranarayanan, Balashanmugam; Nagarajan, D; Selvarani, R; Vijjaykanth, M
2016-10-01
The cervical vertebral maturation (CVM) method is a vital tool for assessing the biological maturation of the orthodontic patient to evaluate the amount of mandibular bone growth left. To assess and visualize the cervical vertebral morphology (bone density) of orthodontic patients of the age group 9,16,27 years. Twenty four subjects with age group of 9,16,27 who were randomly selected and subjected to 3d tomographic study to estimate the biological age of the orthodontic patients by analyzing c1 c2 and c3 vertebrae. The results showed that bone density of males is lesser than females in 9 and 16 years, whereas they have more bone density than females in 27 years. The study provides qualitative method of assessing the biological age of the patient by using images of cervical vertebrae by three dimensional approach. Hence it can be useful for orthodontic diagnosis and treatment plan.
-
Prasad, Mandava; Ganji, Venkata Suresh Kumar; George, Suja Ani; Talapaneni, Ashok Kumar; Shetty, Sharath Kumar
2013-01-01
Evaluation of skeletal maturity in human individuals is an important aspect in orthodontics and dentofacial orthopedics because, growth guidance and fundamental structural changes are essential for treatment of skeletal discrepancies in all the three planes. Among various growth assessment methods, cervical vertebra maturation stages and hand wrist have been correlated with the individual growth changes during puberty. The purpose of this study is to determine correlation of the CVM index with the modified median phalanx index (MP3) as described by Rajagopal and Kansal. 200 subjects (100 males and 100 females) of Nellore, Indian origin boys aged between 10 to 19 years and girls of 8 to 16 years were selected for the study. The subjects are selected randomly from patients visiting the Departments of Orthodontics and Dentofacial Orthopedics, Pediatric dentistry and Oral medicine and Radiology at Narayana Dental College and Hospital. Nellore. Radiographs of left hand MP3 and lateral cephalogram were taken. Cohen's kappa statistic was used to assess the agreement between the two measurements based on categorical variables. There was a good concordance between 6 stages of CVMI (Hassel and Farman) and the 6 stages of MP3 (Rajagopal and Kansal). Physiological maturity was earlier in females than in males when compared to the individuals of opposite sex of same chronological age. Chronological age was not a valid predictor of assessing the skeletal maturity because of significant variations in the distribution of CVMI and MP3 stages with respect to individual chronological age distribution.
-
76 FR 45811 - Animal Drug User Fee Rates and Payment Procedures for Fiscal Year 2012
Federal Register 2010, 2011, 2012, 2013, 2014
2011-08-01
... Lisa Kable, Center for Veterinary Medicine (HFV-10), Food and Drug Administration, 7529 Standish Pl... Medicine (CVM) at: [email protected] . SUPPLEMENTARY INFORMATION: I. Background Section 740 of the FD&C... from the base years in column 3. At the bottom right of the table the sum of the values in column 5 is...
-
What ignited Forest Service interest in nonmarket valuation in fire economics?
John B. Loomis; Armando González-Cabán
2009-01-01
This paper traces the origin and evolution of the application of nonmarket valuation techniques to fire management within the USDA Forest Service. The motivation for contingent valuation (CVM) studies that quantify existence value is traced to the need for monetary benefits of protecting spotted owl old-growth forest habitat from fire in the early 1990s. Two large...
-
Federal Register 2010, 2011, 2012, 2013, 2014
2010-09-24
... health industry that submits new animal drug applications to CVM's Office of New Animal Drug Evaluation... agreed to in the Animal Drug User Fee Amendments (ADUFA II) of 2008 ( http://www.fda.gov/ForIndustry/UserFees/AnimalDrugUserFeeActADUFA/ucm044941.htm ). The ONADE will be soliciting feedback on both the e...
-
Multi-view L2-SVM and its multi-view core vector machine.
Huang, Chengquan; Chung, Fu-lai; Wang, Shitong
2016-03-01
In this paper, a novel L2-SVM based classifier Multi-view L2-SVM is proposed to address multi-view classification tasks. The proposed Multi-view L2-SVM classifier does not have any bias in its objective function and hence has the flexibility like μ-SVC in the sense that the number of the yielded support vectors can be controlled by a pre-specified parameter. The proposed Multi-view L2-SVM classifier can make full use of the coherence and the difference of different views through imposing the consensus among multiple views to improve the overall classification performance. Besides, based on the generalized core vector machine GCVM, the proposed Multi-view L2-SVM classifier is extended into its GCVM version MvCVM which can realize its fast training on large scale multi-view datasets, with its asymptotic linear time complexity with the sample size and its space complexity independent of the sample size. Our experimental results demonstrated the effectiveness of the proposed Multi-view L2-SVM classifier for small scale multi-view datasets and the proposed MvCVM classifier for large scale multi-view datasets. Copyright © 2015 Elsevier Ltd. All rights reserved.
-
RESPIRATORY PHYSIOLOGICAL AND ALLERGIC-TYPE RESPONSES TO AN EXTRACT OF Stachybotrys chartarum IN BALB/C MICE. ME Viana1, N Haykal-Coates2, S H Gavett2, MJ Selgrade2, and M D W Ward2. 1APR/CVM, NCSU, Raleigh, NC, USA. 2NHEERL, ORD, US EPA, RTP, NC, USA.
Rationale: assess the ab... -
Federal Register 2010, 2011, 2012, 2013, 2014
2011-05-23
... questions in the survey are designed to elicit expert opinions and clarify areas of agreement and... Federal Register for comment prior to finalizing them for the pretest and the actual survey. (CVM's... respondent responses (in hours) \\2\\ Pretest 5 1 5 20/60 1.65 Survey 100 1 100 20/60 33 Total 34.65 \\1\\ There...
-
ERIC Educational Resources Information Center
Mechling, Linda C.; Ayres, Kevin M.; Bryant, Kathryn J.; Foster, Ashley L.
2014-01-01
This study compared the effects of three procedures (video prompting: VP, video modeling: VM, and continuous video modeling: CVM) on task completion by three high school students with moderate intellectual disability. The comparison was made across three sets of fundamentally different tasks (putting away household items in clusters of two items;…
-
R.A. Souter; J. Michael Bowker
1996-01-01
It is a generally known statistical fact that the mean of a nonlinear function of a set of random variables is not equivalent to the function evaluated at the means of the variables. However, in dichotomous choice contingent valuation studies, a common practice is to calculate an overall mean (or median) by integrating over offer space (numerically or analytically) an...
-
Kaga, Satoshi; Suzuki, Teppei
2017-01-01
Background In Japan over the past few years, more attention has been focused on unnoticed solitary death in the context of an aging society and the trend toward nuclear family. A number of institutions and companies have implemented a prevention measure with digital terrestrial broadcasting telecare services for the elderly: Hokkaido University; TV-Asahi Corporation; Hitachi, Ltd; Iwamizawa City; Hokkaido Television Broadcasting Co, Ltd; and Hamanasu Information Co, Ltd. Although this system is provided free of charge as a demonstration test, determining the appropriate price for the service is required for its sustainable operation. Objective The aim of this study was to quantify individual willingness to pay (WTP) so as to test the tenability of digital terrestrial broadcasting service for elderly telecare. Methods We used the contingent valuation method (CVM) to estimate the WTP for this service among 305 citizens (valid response rate 76.0%) living in Japan. A questionnaire survey was conducted for people aged 18 to 100 years according to Japanese age distribution from September 2016. To elicit WTP, we adopted a double-bound dichotomous choice method to ask the respondents whether they agree or disagree with the price we offered. Results The median WTP for this service’s monthly fee is estimated to be 431 JPY (approximately US $3.7). The finding suggests that gender (0.66, P=.01), health consciousness (1.08, P=.01), willingness to use (2.38, P<.001), and seeing others less than once a week (1.00, P=.06) made a positive effect on WTP. Conclusions We conclude that reliable WTP was elicited by CVM based on an Internet survey. Calculated median WTP for digital terrestrial broadcasting service for elderly telecare was 431 JPY (approximately US $3.7). In the analysis of factors that affect WTP, constant factors, log-bid, health consciousness, gender, see others less than one time for week, and willingness to use made positive effect to probability of acceptance. In comparison of WTP in different groups, age groups showed that WTP of the elderly group was higher than WTP of the middle age group and younger age group. However, WTP surveys need to be carefully conducted to minimize the sampling bias and allocate accurate structure of gender distribution. PMID:29066428
-
NASA Astrophysics Data System (ADS)
Loomis, John; Smith, Adam; Huszar, Paul
2005-08-01
The contingent valuation method (CVM) was used to estimate homeowners' willingness to pay for water leasing to maintain stable lake levels at an irrigation reservoir in a residential neighborhood. A binary logit model was used to analyze households' voter referendum responses for maintaining the lake level. The median willingness to pay (WTP) was found to be $368 per year for lakefront residents and $59 per year for off-lake residents. The median WTP for lakefront residents was significantly different from off-lake residents at the 90% confidence level. Using the median WTP for lakefront and nonlakefront residents, we found that the increase in homeowner association fees would generate approximately $43,000, enough money to lease sufficient water to reach the target higher lake level in a normal water year.
-
Reading, Stacey A; Prickett, Karel
2013-06-01
New-generation active videogames (AVGs) use motion-capture video cameras to connect a player's arm, leg, and body movements through three-dimensional space to on-screen activity. We sought to determine if the whole-body movements required to play the AVG elicited moderate-intensity physical activity (PA) in children. A secondary aim was to examine the utility of using accelerometry to measure the activity intensity of AVG play in this age group. The PA levels of boys (n=26) and girls (n=15) 5-12 years of age were measured by triaxial accelerometry (n=25) or accelerometry and indirect calorimetry (IC) (n=16) while playing the "Kinect Adventures!" videogame for the Xbox Kinect (Microsoft(®), Redmond, WA) gaming system. The experiment simulated a typical 20-minute in-home free-play gaming session. Using 10-second recording epochs, the average (mean±standard deviation) PA intensity over 20 minutes was 4.4±0.9, 3.2±0.7, and 3.3±0.6 metabolic equivalents (METs) when estimated by IC or vertical axis (Crouter et al. intermittent lifestyle equation for vertical axis counts/10 seconds [Cva2RM]) and vector magnitude (Crouter et al. intermittent lifestyle equation for vector magnitude counts/10 seconds [Cvm2RM]) accelerometry. In total, 16.9±3.2 (IC), 10.6±4.5 (Cva2RM), and 11.1±3.9 (Cvm2RM) minutes of game playing time were at a 3 MET intensity or higher. In this study, children played the Xbox Kinect AVG at moderate-intensity PA levels. The study also showed that current accelerometry-based methods underestimated the PA of AVG play compared with IC. With proper guidance and recommendations for use, video motion-capture AVG systems could reduce sedentary screen time and increase total daily moderate PA levels for children. Further study of these AVG systems is warranted.
-
Ahmed, Adeel; Masud, Muhammad Mehedi; Al-Amin, Abul Quasem; Yahaya, Siti Rohani Binti; Rahman, Mahfuzur; Akhtar, Rulia
2015-06-01
This study empirically estimates farmers' willingness to pay (WTP) for a planned adaptation programme for addressing climate issues in Pakistan's agricultural sectors. The contingent valuation method (CVM) was employed to determine a monetary valuation of farmers' preferences for a planned adaptation programme by ascertaining the value attached to address climatic issues. The survey was conducted by distributing structured questionnaires among Pakistani farmers. The study found that 67 % of respondents were willing to pay for a planned adaptation programme. However, several socioeconomic and motivational factors exert greater influence on their willingness to pay (WTP). This paper specifies the steps needed for all institutional bodies to better address issues in climate change. The outcomes of this paper will support attempts by policy makers to design an efficient adaptation framework for mitigating and adapting to the adverse impacts of climate change.
-
Masud, Muhammad Mehedi; Junsheng, Ha; Akhtar, Rulia; Al-Amin, Abul Quasem; Kari, Fatimah Binti
2015-02-01
This paper estimates Malaysian farmers' willingness to pay (WTP) for a planned adaptation programme for addressing climate issues in the Malaysian agricultural sector. We used the contingent valuation method (CVM) for a monetary valuation of farmers' preferences for a planned adaptation programme by ascertaining the value attached to address climatic issues in the Malaysian agricultural sector. Structured questionnaires were distributed among the sampled farmers. The study found that 74 % of respondents were willing to pay for a planned adaptation programme and that several socioeconomic and motivation factors have greater influence on their WTP. This paper clearly specifies the steps needed for all institutional bodies to better address issues in climate change. The outcomes of this paper will support policy makers to better design an efficient adaptation framework for adapting to the adverse impacts of climate change.
-
Assessment of immune responses to Penicillium chrysogenum and characterization of its allergens
Yongjoo Chung1, Michael E Viana2, Lisa B Copeland3, and MaryJane K Selgrade3, Marsha D W Ward3. 1 UNC, SPH, Chapel Hill, NC, 2NCSU, CVM, Raleigh, NC, 3US EPA, ORD, NHEERL, RTP,... -
Maternal caffeine consumption and risk of cardiovascular malformations.
Browne, Marilyn L; Bell, Erin M; Druschel, Charlotte M; Gensburg, Lenore J; Mitchell, Allen A; Lin, Angela E; Romitti, Paul A; Correa, Adolfo
2007-07-01
The physiologic effects and common use of caffeine during pregnancy call for examination of maternal caffeine consumption and risk of birth defects. Epidemiologic studies have yielded mixed results, but such studies have grouped etiologically different defects and have not evaluated effect modification. The large sample size and precise case classification of the National Birth Defects Prevention Study allowed us to examine caffeine consumption and specific cardiovascular malformation (CVM) case groups. We studied consumption of caffeinated coffee, tea, soda, and chocolate to estimate total caffeine intake and separately examined exposure to each caffeinated beverage. Smoking, alcohol, vasoactive medications, folic acid supplement use, and infant gender were evaluated for effect modification. Maternal interview reports for 4,196 CVM case infants overall and 3,957 control infants were analyzed. We did not identify any significant positive associations between maternal caffeine consumption and CVMs. For tetralogy of Fallot, nonsignificant elevations in risk were observed for moderate (but not high) caffeine intake overall and among nonsmokers (ORs of 1.3 to 1.5). Risk estimates for both smoking and consuming caffeine were less than the sum of the excess risks for each exposure. We observed an inverse trend between coffee intake and risk of atrial septal defect; however, this single significant pattern of association might have been a chance finding. Our study found no evidence for an appreciable teratogenic effect of caffeine with regard to CVMs. (c) 2007 Wiley-Liss, Inc.
-
Biodegradable polymer nanoparticles that rapidly penetrate the human mucus barrier
Tang, Benjamin C.; Dawson, Michelle; Lai, Samuel K.; Wang, Ying-Ying; Suk, Jung Soo; Yang, Ming; Zeitlin, Pamela; Boyle, Michael P.; Fu, Jie; Hanes, Justin
2009-01-01
Protective mucus coatings typically trap and rapidly remove foreign particles from the eyes, gastrointestinal tract, airways, nasopharynx, and female reproductive tract, thereby strongly limiting opportunities for controlled drug delivery at mucosal surfaces. No synthetic drug delivery system composed of biodegradable polymers has been shown to penetrate highly viscoelastic human mucus, such as non-ovulatory cervicovaginal mucus, at a significant rate. We prepared nanoparticles composed of a biodegradable diblock copolymer of poly(sebacic acid) and poly(ethylene glycol) (PSA-PEG), both of which are routinely used in humans. In fresh undiluted human cervicovaginal mucus (CVM), which has a bulk viscosity approximately 1,800-fold higher than water at low shear, PSA-PEG nanoparticles diffused at an average speed only 12-fold lower than the same particles in pure water. In contrast, similarly sized biodegradable nanoparticles composed of PSA or poly(lactic-co-glycolic acid) (PLGA) diffused at least 3,300-fold slower in CVM than in water. PSA-PEG particles also rapidly penetrated sputum expectorated from the lungs of patients with cystic fibrosis, a disease characterized by hyperviscoelastic mucus secretions. Rapid nanoparticle transport in mucus is made possible by the efficient partitioning of PEG to the particle surface during formulation. Biodegradable polymeric nanoparticles capable of overcoming human mucus barriers and providing sustained drug release open significant opportunities for improved drug and gene delivery at mucosal surfaces. PMID:19901335
-
Kaga, Satoshi; Suzuki, Teppei; Ogasawara, Katsuhiko
2017-10-24
In Japan over the past few years, more attention has been focused on unnoticed solitary death in the context of an aging society and the trend toward nuclear family. A number of institutions and companies have implemented a prevention measure with digital terrestrial broadcasting telecare services for the elderly: Hokkaido University; TV-Asahi Corporation; Hitachi, Ltd; Iwamizawa City; Hokkaido Television Broadcasting Co, Ltd; and Hamanasu Information Co, Ltd. Although this system is provided free of charge as a demonstration test, determining the appropriate price for the service is required for its sustainable operation. The aim of this study was to quantify individual willingness to pay (WTP) so as to test the tenability of digital terrestrial broadcasting service for elderly telecare. We used the contingent valuation method (CVM) to estimate the WTP for this service among 305 citizens (valid response rate 76.0%) living in Japan. A questionnaire survey was conducted for people aged 18 to 100 years according to Japanese age distribution from September 2016. To elicit WTP, we adopted a double-bound dichotomous choice method to ask the respondents whether they agree or disagree with the price we offered. The median WTP for this service's monthly fee is estimated to be 431 JPY (approximately US $3.7). The finding suggests that gender (0.66, P=.01), health consciousness (1.08, P=.01), willingness to use (2.38, P<.001), and seeing others less than once a week (1.00, P=.06) made a positive effect on WTP. We conclude that reliable WTP was elicited by CVM based on an Internet survey. Calculated median WTP for digital terrestrial broadcasting service for elderly telecare was 431 JPY (approximately US $3.7). In the analysis of factors that affect WTP, constant factors, log-bid, health consciousness, gender, see others less than one time for week, and willingness to use made positive effect to probability of acceptance. In comparison of WTP in different groups, age groups showed that WTP of the elderly group was higher than WTP of the middle age group and younger age group. However, WTP surveys need to be carefully conducted to minimize the sampling bias and allocate accurate structure of gender distribution. ©Satoshi Kaga, Teppei Suzuki, Katsuhiko Ogasawara. Originally published in the Interactive Journal of Medical Research (http://www.i-jmr.org/), 24.10.2017.
-
Yang, Xiaobin; Chen, Zhilong; Guo, Dongjun
2015-07-01
Urban underground transportation projects are introduced to address problems of scarce green land and traffic pollution. As construction of urban underground transportation is still in its infancy, there is no definite quantitative measurement on whether the construction is beneficial and what influences it will place on the region in China. This study intends to construct a comprehensive evaluation method for evaluating social, economic and environmental benefits of urban underground transportation projects and proposes the concept, role and principle for evaluation of environmental and economic benefits. It figures out relationship between the environment and factors of city development. It also summarizes three relevant factors, including transportation, biophysics and social economy, and works out indicators to evaluate the influence of urban underground transportation construction. Based on Contingent Valuation Method (CVM), Cost of Illness Approach (CIA), Human Capital Approach (HCA), this paper constructs 13 monetization calculation models for social, economic and environmental benefits in response to seven aspects, namely, reducing noise pollution and air pollution, using land efficiently, improving traffic safety, reducing traffic congestion, saving shipping time and minimizing transportation costs.
-
NASA Astrophysics Data System (ADS)
Harvey, J.-P.; Gheribi, A. E.; Chartrand, P.
2012-12-01
In this work, an in silico procedure to generate a fully coherent set of thermodynamic properties obtained from classical molecular dynamics (MD) and Monte Carlo (MC) simulations is proposed. The procedure is applied to the Al-Zr system because of its importance in the development of high strength Al-Li alloys and of bulk metallic glasses. Cohesive energies of the studied condensed phases of the Al-Zr system (the liquid phase, the fcc solid solution, and various orthorhombic stoichiometric compounds) are calculated using the modified embedded atom model (MEAM) in the second-nearest-neighbor formalism (2NN). The Al-Zr MEAM-2NN potential is parameterized in this work using ab initio and experimental data found in the literature for the AlZr3-L12 structure, while its predictive ability is confirmed for several other solid structures and for the liquid phase. The thermodynamic integration (TI) method is implemented in a general MC algorithm in order to evaluate the absolute Gibbs energy of the liquid and the fcc solutions. The entropy of mixing calculated from the TI method, combined to the enthalpy of mixing and the heat capacity data generated from MD/MC simulations performed in the isobaric-isothermal/canonical (NPT/NVT) ensembles are used to parameterize the Gibbs energy function of all the condensed phases in the Al-rich side of the Al-Zr system in a CALculation of PHAse Diagrams (CALPHAD) approach. The modified quasichemical model in the pair approximation (MQMPA) and the cluster variation method (CVM) in the tetrahedron approximation are used to define the Gibbs energy of the liquid and the fcc solid solution respectively for their entire range of composition. Thermodynamic and structural data generated from our MD/MC simulations are used as input data to parameterize these thermodynamic models. A detailed analysis of the validity and transferability of the Al-Zr MEAM-2NN potential is presented throughout our work by comparing the predicted properties obtained from this formalism with available ab initio and experimental data for both liquid and solid phases.
-
Long, Andrew M; Short, Steven M
2016-01-01
To address questions about algal virus persistence (i.e., continued existence) in the environment, rates of decay of infectivity for two viruses that infect Chlorella-like algae, ATCV-1 and CVM-1, and a virus that infects the prymnesiophyte Chrysochromulina parva, CpV-BQ1, were estimated from in situ incubations in a temperate, seasonally frozen pond. A series of experiments were conducted to estimate rates of decay of infectivity in all four seasons with incubations lasting 21 days in spring, summer and autumn, and 126 days in winter. Decay rates observed across this study were relatively low compared with previous estimates obtained for other algal viruses, and ranged from 0.012 to 11% h−1. Overall, the virus CpV-BQ1 decayed most rapidly whereas ATCV-1 decayed most slowly, but for all viruses the highest decay rates were observed during the summer and the lowest were observed during the winter. Furthermore, the winter incubations revealed the ability of each virus to overwinter under ice as ATCV-1, CVM-1 and CpV-BQ1 retained up to 48%, 19% and 9% of their infectivity after 126 days, respectively. The observed resilience of algal viruses in a seasonally frozen freshwater pond provides a mechanism that can support the maintenance of viral seed banks in nature. However, the high rates of decay observed in the summer demonstrate that virus survival and therefore environmental persistence can be subject to seasonal bottlenecks. PMID:26943625
-
Gray, Ryan S; Wilm, Thomas P; Smith, Jeff; Bagnat, Michel; Dale, Rodney M; Topczewski, Jacek; Johnson, Stephen L; Solnica-Krezel, Lilianna
2014-02-01
Congenital vertebral malformations (CVM) occur in 1 in 1000 live births and in many cases can cause spinal deformities, such as scoliosis, and result in disability and distress of affected individuals. Many severe forms of the disease, such as spondylocostal dystostosis, are recessive monogenic traits affecting somitogenesis, however the etiologies of the majority of CVM cases remain undetermined. Here we demonstrate that morphological defects of the notochord in zebrafish can generate congenital-type spine defects. We characterize three recessive zebrafish leviathan/col8a1a mutant alleles ((m531, vu41, vu105)) that disrupt collagen type VIII alpha1a (col8a1a), and cause folding of the embryonic notochord and consequently adult vertebral column malformations. Furthermore, we provide evidence that a transient loss of col8a1a function or inhibition of Lysyl oxidases with drugs during embryogenesis was sufficient to generate vertebral fusions and scoliosis in the adult spine. Using periodic imaging of individual zebrafish, we correlate focal notochord defects of the embryo with vertebral malformations (VM) in the adult. Finally, we show that bends and kinks in the notochord can lead to aberrant apposition of osteoblasts normally confined to well-segmented areas of the developing vertebral bodies. Our results afford a novel mechanism for the formation of VM, independent of defects of somitogenesis, resulting from aberrant bone deposition at regions of misshapen notochord tissue. Copyright © 2013 Elsevier Inc. All rights reserved.
-
Gray, Ryan S.; Wilm, Thomas; Smith, Jeff; Bagnat, Michel; Dale, Rodney M.; Topczewski, Jacek; Johnson, Stephen L.; Solnica-Krezel, Lilianna
2014-01-01
Congenital vertebral malformations (CVM) occur in 1 in 1,000 live births and in many cases can cause spinal deformities, such as scoliosis, and result in disability and distress of affected individuals. Many severe forms of the disease, such as spondylocostal dystostosis, are recessive monogenic traits affecting somitogenesis, however the etiologies of the majority of CVM cases remain undetermined. Here we demonstrate that morphological defects of the notochord in zebrafish can generate congenital-type spine defects. We characterize three recessive zebrafish leviathan/col8a1a mutant alleles (m531, vu41, vu105) that disrupt collagen type VIII alpha1a (col8a1a), and cause folding of the embryonic notochord and consequently adult vertebral column malformations. Furthermore, we provide evidence that a transient loss of col8a1a function or inhibition of Lysyl oxidases with drugs during embryogenesis was sufficient to generate vertebral fusions and scoliosis in the adult spine. Using periodic imaging of individual zebrafish, we correlate focal notochord defects of the embryo with vertebral malformations (VM) in the adult. Finally, we show that bends and kinks in the notochord can lead to aberrant apposition of osteoblasts normally confined to well-segmented areas of the developing vertebral bodies. Our results afford a novel mechanism for the formation of VM, independent of defects of somitogenesis, resulting from aberrant bone deposition at regions of misshapen notochord tissue. PMID:24333517
-
2012-04-30
al 2002, Flores and Barnett 2009, Franchi 2011, Howe 1983, Huanca Ghislanzoni, et al 2012, Illing and Morris 1998, Liu et al. 2007, McNamara et...skeletal correction with elastics is questionable (Moore 1959). Additionally, it has been found advantageous to use appliances that control the vertical...as an indicator to detect the optimal time to start treatment with functional appliances (Baccetti et al. 2005). One benefit to the patient with CVM
-
NASA Astrophysics Data System (ADS)
Kopsidas, Odysseas; Batzias, Fragiskos
2012-12-01
In this work, a methodological framework under the form of an algorithmic procedure, including 28 activity stages and 6 decision nodes, has been developed for evaluating environmental impact caused by industrial activities. The main part of this procedure is a modification of the Contingent Valuation Method (CVM), which is heavily relied on survey-based estimation of WTP-WTA (willingness to pay/accept, respectively). The survey may take place either under a strictly controlled environment or in situ and as-is ('laboratory conditions' or 'field conditions', respectively, in the terminology of experimental economics). Implementation of this methodology is presented, referring to three cases of industrial pollution (in three different sites) caused by (i) a cement producing units, (ii) an oil refinery complex, and (iii) an industrialized small city with an intensively polluted port, where several industrial units co-exist, all of them located in the vicinity of Athens, Greece. The results are interpreted/discussed and conclusions are drawn.
-
NTF: Soldering Technology Development for Cryogenics
NASA Technical Reports Server (NTRS)
Hall, E. T., Jr.
1985-01-01
The advent of the National Transonic Facility (NTF) brought about a new application for an old joining method, soldering. Soldering for use at cryogenic temperatures requires that solders remain ductile and free from tin-pest (grey tin), have toughness to withstand aerodynamic loads associated with flight research, and maintain their surface finishes. Solders are used to attach 347 Stainless-Steel tubing in surface grooves of models. The solder must fill up the gap and metallurgically bound to the tubing and model. Cryogenic temperatures require that only specific materials for models can be used, including: Vasco Max 200 CVM, lescalloy A-286 Vac Arc, pH 13-8 Mo. Solders identified for testing at this time are: 50% Sn - 49.5% Pb - 0.5% Sb, 95% Sn - 5% Sb, 50% In 50% Pb, and 37.5% Sn - 37.5% Pb - 25% In. With these materials and solders, it is necessary to determine their solderability. After solderability is determined, tube/groove specimens are fabricated and stressed under cryogenic temperatures. Compatible solders are then used for acutual models.
-
Christantoni, Maria; Damigos, Dimitris
2018-05-15
In many instances, Contingent Valuation practitioners rely on voluntary monetary contributions, despite the fact that they are deemed to be neither incentive compatible in theory nor demand revealing in practice. The reason is that they are suitable for most field applications and offer benefits that may outweigh their drawbacks. This paper endeavors to contribute to the literature by exploring the effect of donation payments with differing incentive structures and information levels on contingent values and on respondents' uncertainty regarding the donations declared. To this end, a field survey was conducted using a sample of 332 respondents who were randomly assigned to one of three different mechanisms: (1) individual contribution (hereinafter CVM treatment); (2) individual contribution with provision point mechanism (PPM), where the total cost of the project is unknown (hereinafter PPM treatment); and (3) individual contribution with PPM, where the total cost of the project is known (hereinafter PPM-INF treatment). The results indicate that there are no statistically significant differences in willingness to pay (WTP) estimates between the CVM and PPM treatments nor between the PPM and the PPM-INF treatments. The results also indicate that the PPM has a positive effect on respondents' certainty level, but there is no evidence that the certainty level is affected by the project information cost. The results are mixed compared to previous research efforts. Thus, further tests are necessary in field comparisons and under different information environments before any definite recommendations can be made. Copyright © 2017 Elsevier B.V. All rights reserved.
-
Simjee, S; White, D G; McDermott, P F; Wagner, D D; Zervos, M J; Donabedian, S M; English, L L; Hayes, J R; Walker, R D
2002-12-01
Thirty-five enterococcal isolates were recovered from dogs diagnosed with urinary tract infections at the Michigan State University Veterinary Teaching Hospital over a 2-year period (1996 to 1998). Isolated species included Enterococcus faecium (n = 13), Enterococcus faecalis (n = 7), Enterococcus gallinarum (n = 11), and Enterococcus casseliflavus (n = 4). Antimicrobial susceptibility testing revealed several different resistance phenotypes, with the majority of the enterococcal isolates exhibiting resistance to three or more antibiotics. One E. faecium isolate, CVM1869, displayed high-level resistance to vancomycin (MIC > 32 micro g/ml) and gentamicin (MIC > 2,048 micro g/ml). Molecular analysis of this isolate revealed the presence of Tn1546 (vanA), responsible for high-level vancomycin resistance, and Tn5281 carrying aac6'-aph2", conferring high-level aminoglycoside resistance. Pulsed-field gel electrophoresis analysis revealed that CVM1869 was a canine E. faecium clone that had acquired Tn1546, perhaps from a human vancomycin-resistant E. faecium. Transposons Tn5281 and Tn1546 were located on two different conjugative plasmids. Sequence analysis revealed that in Tn1546, ORF1 had an 889-bp deletion and an IS1216V insertion at the 5' end and an IS1251 insertion between vanS and vanH. To date, this particular form of Tn1546 has only been described in human clinical vancomycin-resistant enterococcus isolates unique to the United States. Additionally, this is the first report of a vancomycin-resistant E. faecium isolated from a companion animal in the United States.
-
Fales-Williams, Amanda; Kramer, Travis; Heer, Rex; Danielson, Jared
2005-01-01
Senior veterinary students in the Iowa State University College of Veterinary Medicine (ISU CVM) participate in clinical rotations, among them a two-week necropsy rotation. The students have access to the rotation syllabus on the ISU CVM intranet site. To promote rapid comprehension of necropsy protocol, students completed a pre-exam on the syllabus. This exercise evolved from a paper quiz to an online pre-exam, using course management software to improve use of class time, increase feedback, and shift the focus to acquisition of knowledge. The students were encouraged to work collaboratively on the pre-exam and could make repeated attempts. We predicted that professional students would make multiple attempts at the pre-exam until the desired score was attained. This exercise achieves multiple goals. First, the exam encourages early review of necropsy protocol. Second, use of WebCT allows for instant, automatic, and consistent feedback from the instructor, reducing redundancy while improving the quality of communication between student and instructor and thus using faculty time more efficiently. The instructor can quickly identify and rectify common misunderstandings through this interface. Third, by allowing discussion and repeated attempts, we can ensure that there is less pressure associated with the exam. Statistical analysis of the students' performance supports the prediction that students would repeat the exam until the desired score was achieved. Subjectively, as a result of implementation of an online pre-exam, the instructor has observed students to be more engaged with the material at an earlier point in the rotation.
-
NASA Astrophysics Data System (ADS)
Zhao, L.; Chen, P.; Jordan, T. H.; Olsen, K. B.; Maechling, P.; Faerman, M.
2004-12-01
The Southern California Earthquake Center (SCEC) is developing a Community Modeling Environment (CME) to facilitate the computational pathways of physics-based seismic hazard analysis (Maechling et al., this meeting). Major goals are to facilitate the forward modeling of seismic wavefields in complex geologic environments, including the strong ground motions that cause earthquake damage, and the inversion of observed waveform data for improved models of Earth structure and fault rupture. Here we report on a unified approach to these coupled inverse problems that is based on the ability to generate and manipulate wavefields in densely gridded 3D Earth models. A main element of this approach is a database of receiver Green tensors (RGT) for the seismic stations, which comprises all of the spatial-temporal displacement fields produced by the three orthogonal unit impulsive point forces acting at each of the station locations. Once the RGT database is established, synthetic seismograms for any earthquake can be simply calculated by extracting a small, source-centered volume of the RGT from the database and applying the reciprocity principle. The partial derivatives needed for point- and finite-source inversions can be generated in the same way. Moreover, the RGT database can be employed in full-wave tomographic inversions launched from a 3D starting model, because the sensitivity (Fréchet) kernels for travel-time and amplitude anomalies observed at seismic stations in the database can be computed by convolving the earthquake-induced displacement field with the station RGTs. We illustrate all elements of this unified analysis with an RGT database for 33 stations of the California Integrated Seismic Network in and around the Los Angeles Basin, which we computed for the 3D SCEC Community Velocity Model (SCEC CVM3.0) using a fourth-order staggered-grid finite-difference code. For a spatial grid spacing of 200 m and a time resolution of 10 ms, the calculations took ~19,000 node-hours on the Linux cluster at USC's High-Performance Computing Center. The 33-station database with a volume of ~23.5 TB was archived in the SCEC digital library at the San Diego Supercomputer Center using the Storage Resource Broker (SRB). From a laptop, anyone with access to this SRB collection can compute synthetic seismograms for an arbitrary source in the CVM in a matter of minutes. Efficient approaches have been implemented to use this RGT database in the inversions of waveforms for centroid and finite moment tensors and tomographic inversions to improve the CVM. Our experience with these large problems suggests areas where the cyberinfrastructure currently available for geoscience computation needs to be improved.
-
NASA Astrophysics Data System (ADS)
Zhu, Jun
Ru and Pt are candidate additional component for improving the high temperature properties of Ni-base superalloys. A thermodynamic description of the Ni-Al-Cr-Ru-Pt system, serving as an essential knowledge base for better alloy design and processing control, was developed in the present study by means of thermodynamic modeling coupled with experimental investigations of phase equilibria. To deal with the order/disorder transition occurring in the Ni-base superalloys, a physical sound model, Cluster/Site Approximation (CSA) was used to describe the fcc phases. The CSA offers computational advantages, without loss of accuracy, over the Cluster Variation Method (CVM) in the calculation of multicomponent phase diagrams. It has been successfully applied to fcc phases in calculating technologically important Ni-Al-Cr phase diagrams. Our effort in this study focused on the two key ternary systems: Ni-Al-Ru and Ni-Al-Pt. The CSA calculated Ni-Al-Ru ternary phase diagrams are in good agreement with the experimental results in the literature and from the current study. A thermodynamic description of quaternary Ni-Al-Cr-Ru was obtained based on the descriptions of the lower order systems and the calculated results agree with experimental data available in literature and in the current study. The Ni-Al-Pt system was thermodynamically modeled based on the limited experimental data available in the literature and obtained from the current study. With the help of the preliminary description, a number of alloy compositions were selected for further investigation. The information obtained was used to improve the current modeling. A thermodynamic description of the Ni-Al-Cr-Pt quaternary was then obtained via extrapolation from its constituent lower order systems. The thermodynamic description for Ni-base superalloy containing Al, Cr, Ru and Pt was obtained via extrapolation. It is believed to be reliable and useful to guide the alloy design and further experimental investigation.
-
Fritz, Sébastien; Capitan, Aurelien; Djari, Anis; Rodriguez, Sabrina C; Barbat, Anne; Baur, Aurélia; Grohs, Cécile; Weiss, Bernard; Boussaha, Mekki; Esquerré, Diane; Klopp, Christophe; Rocha, Dominique; Boichard, Didier
2013-01-01
The regular decrease of female fertility over time is a major concern in modern dairy cattle industry. Only half of this decrease is explained by indirect response to selection on milk production, suggesting the existence of other factors such as embryonic lethal genetic defects. Genomic regions harboring recessive deleterious mutations were detected in three dairy cattle breeds by identifying frequent haplotypes (>1%) showing a deficit in homozygotes among Illumina Bovine 50k Beadchip haplotyping data from the French genomic selection database (47,878 Holstein, 16,833 Montbéliarde, and 11,466 Normande animals). Thirty-four candidate haplotypes (p<10(-4)) including previously reported regions associated with Brachyspina, CVM, HH1, and HH3 in Holstein breed were identified. Haplotype length varied from 1 to 4.8 Mb and frequencies from 1.7 up to 9%. A significant negative effect on calving rate, consistent in heifers and in lactating cows, was observed for 9 of these haplotypes in matings between carrier bulls and daughters of carrier sires, confirming their association with embryonic lethal mutations. Eight regions were further investigated using whole genome sequencing data from heterozygous bull carriers and control animals (45 animals in total). Six strong candidate causative mutations including polymorphisms previously reported in FANCI (Brachyspina), SLC35A3 (CVM), APAF1 (HH1) and three novel mutations with very damaging effect on the protein structure, according to SIFT and Polyphen-2, were detected in GART, SHBG and SLC37A2 genes. In conclusion, this study reveals a yet hidden consequence of the important inbreeding rate observed in intensively selected and specialized cattle breeds. Counter-selection of these mutations and management of matings will have positive consequences on female fertility in dairy cattle.
-
Reed, S M; Howe, D K; Morrow, J K; Graves, A; Yeargan, M R; Johnson, A L; MacKay, R J; Furr, M; Saville, W J A; Williams, N M
2013-01-01
Recent work demonstrated the value of antigen-specific antibody indices (AI and C-value) to detect intrathecal antibody production against Sarcocystis neurona for antemortem diagnosis of equine protozoal myeloencephalitis (EPM). The study was conducted to assess whether the antigen-specific antibody indices can be reduced to a simple serum : cerebrospinal fluid (CSF) titer ratio to achieve accurate EPM diagnosis. Paired serum and CSF samples from 128 horses diagnosed by postmortem examination. The sample set included 44 EPM cases, 35 cervical-vertebral malformation (CVM) cases, 39 neurologic cases other than EPM or CVM, and 10 non-neurologic cases. Antibodies against S. neurona were measured in serum and CSF pairs using the SnSAG2 and SnSAG4/3 (SnSAG2, 4/3) ELISAs, and the ratio of each respective serum titer to CSF titer was determined. Likelihood ratios and diagnostic sensitivity and specificity were calculated based on serum titers, CSF titers, and serum : CSF titer ratios. Excellent diagnostic sensitivity and specificity was obtained from the SnSAG2, 4/3 serum : CSF titer ratio. Sensitivity and specificity of 93.2 and 81.1%, respectively, were achieved using a ratio cutoff of ≤100, whereas sensitivity and specificity were 86.4 and 95.9%, respectively, if a more rigorous cutoff of ≤50 was used. Antibody titers in CSF also provided good diagnostic accuracy. Serum antibody titers alone yielded much lower sensitivity and specificity. The study confirms the value of detecting intrathecal antibody production for antemortem diagnosis of EPM, and they further show that the antigen-specific antibody indices can be reduced in practice to a simple serum : CSF titer ratio. Copyright © 2013 by the American College of Veterinary Internal Medicine.
-
CyberShake: A Physics-Based Seismic Hazard Model for Southern California
NASA Astrophysics Data System (ADS)
Graves, Robert; Jordan, Thomas H.; Callaghan, Scott; Deelman, Ewa; Field, Edward; Juve, Gideon; Kesselman, Carl; Maechling, Philip; Mehta, Gaurang; Milner, Kevin; Okaya, David; Small, Patrick; Vahi, Karan
2011-03-01
CyberShake, as part of the Southern California Earthquake Center's (SCEC) Community Modeling Environment, is developing a methodology that explicitly incorporates deterministic source and wave propagation effects within seismic hazard calculations through the use of physics-based 3D ground motion simulations. To calculate a waveform-based seismic hazard estimate for a site of interest, we begin with Uniform California Earthquake Rupture Forecast, Version 2.0 (UCERF2.0) and identify all ruptures within 200 km of the site of interest. We convert the UCERF2.0 rupture definition into multiple rupture variations with differing hypocenter locations and slip distributions, resulting in about 415,000 rupture variations per site. Strain Green Tensors are calculated for the site of interest using the SCEC Community Velocity Model, Version 4 (CVM4), and then, using reciprocity, we calculate synthetic seismograms for each rupture variation. Peak intensity measures are then extracted from these synthetics and combined with the original rupture probabilities to produce probabilistic seismic hazard curves for the site. Being explicitly site-based, CyberShake directly samples the ground motion variability at that site over many earthquake cycles (i.e., rupture scenarios) and alleviates the need for the ergodic assumption that is implicitly included in traditional empirically based calculations. Thus far, we have simulated ruptures at over 200 sites in the Los Angeles region for ground shaking periods of 2 s and longer, providing the basis for the first generation CyberShake hazard maps. Our results indicate that the combination of rupture directivity and basin response effects can lead to an increase in the hazard level for some sites, relative to that given by a conventional Ground Motion Prediction Equation (GMPE). Additionally, and perhaps more importantly, we find that the physics-based hazard results are much more sensitive to the assumed magnitude-area relations and magnitude uncertainty estimates used in the definition of the ruptures than is found in the traditional GMPE approach. This reinforces the need for continued development of a better understanding of earthquake source characterization and the constitutive relations that govern the earthquake rupture process.
-
CyberShake: A Physics-Based Seismic Hazard Model for Southern California
Graves, R.; Jordan, T.H.; Callaghan, S.; Deelman, E.; Field, E.; Juve, G.; Kesselman, C.; Maechling, P.; Mehta, G.; Milner, K.; Okaya, D.; Small, P.; Vahi, K.
2011-01-01
CyberShake, as part of the Southern California Earthquake Center's (SCEC) Community Modeling Environment, is developing a methodology that explicitly incorporates deterministic source and wave propagation effects within seismic hazard calculations through the use of physics-based 3D ground motion simulations. To calculate a waveform-based seismic hazard estimate for a site of interest, we begin with Uniform California Earthquake Rupture Forecast, Version 2.0 (UCERF2.0) and identify all ruptures within 200 km of the site of interest. We convert the UCERF2.0 rupture definition into multiple rupture variations with differing hypocenter locations and slip distributions, resulting in about 415,000 rupture variations per site. Strain Green Tensors are calculated for the site of interest using the SCEC Community Velocity Model, Version 4 (CVM4), and then, using reciprocity, we calculate synthetic seismograms for each rupture variation. Peak intensity measures are then extracted from these synthetics and combined with the original rupture probabilities to produce probabilistic seismic hazard curves for the site. Being explicitly site-based, CyberShake directly samples the ground motion variability at that site over many earthquake cycles (i. e., rupture scenarios) and alleviates the need for the ergodic assumption that is implicitly included in traditional empirically based calculations. Thus far, we have simulated ruptures at over 200 sites in the Los Angeles region for ground shaking periods of 2 s and longer, providing the basis for the first generation CyberShake hazard maps. Our results indicate that the combination of rupture directivity and basin response effects can lead to an increase in the hazard level for some sites, relative to that given by a conventional Ground Motion Prediction Equation (GMPE). Additionally, and perhaps more importantly, we find that the physics-based hazard results are much more sensitive to the assumed magnitude-area relations and magnitude uncertainty estimates used in the definition of the ruptures than is found in the traditional GMPE approach. This reinforces the need for continued development of a better understanding of earthquake source characterization and the constitutive relations that govern the earthquake rupture process. ?? 2010 Springer Basel AG.
-
Li, Zheng-Ling; Chen, Ming-Yong; Wu, Zhao-Lu; Wang, Qian; Dong, Yong-Hua
2009-06-01
By using contingent valuation method (CVM), an investigation was made from November 2007 to March 2008 on the perception and attitude of 196 households in 5 villages within 2 planned Asian elephant conservation corridors in Xishuangbanna to the construction of the corridors. 80.61% of the interviewees conditionally supported the corridors construction. The main factors affecting the interviewees' support willingness included their education level, per capita income, and perceptions to Asian elephant protection, human-elephant relations, and corridor utilization patterns and its beneficiaries, among which, the interviewees' awareness of Asian elephant conservation, corridor utilization patterns, and corridor beneficiaries had strong influence on the support willingness, with the correlation coefficient being 0.231, 0.236, and -0.304, respectively. The rural community holding the land tenure played a key role in the corridors construction. To effectively design and planning the construction of biological conservation corridor, it is necessary to have a deep understanding on the perceptions and attitudes of rural community to the construction of the corridor and to obtain their support and participation for this construction.
-
Romano, Karen Rodrigues; Dias Bartolomeu Abadio Finco, Fernanda; Rosenthal, Amauri; Vinicius Alves Finco, Marcus; Deliza, Rosires
2016-11-01
This study aimed at estimating the consumer's willingness to pay (WTP) more for value-added pomegranate juice using the contingent valuation method (CVM). The WTP was estimated applying the open-ended elicitation technique with 454 consumers in two supermarkets located in Rio de Janeiro, Brazil. The average consumer's WTP more for pomegranate juice was estimated in R$2.04 (Brazilian currency) and the income elasticity coefficient at the midpoint was 0.19, i.e., a 10% increase in consumer income will increase, on average, 1.9% the WTP of pomegranate juice (ceteris paribus). Therefore, the income elasticity coefficient was considered inelastic, once an increase in income would have low effect on the WTP for these consumers. The results indicated that the consumers were interested in acquiring a non-traditional juice processed using a technology that preserves vitamins and antioxidants, maintains the flavor of "fresh juice" without colorants and preservatives, despite the pomegranate is not part of the Brazilian diet. Copyright © 2016 Elsevier Ltd. All rights reserved.
-
Earthquake source tensor inversion with the gCAP method and 3D Green's functions
NASA Astrophysics Data System (ADS)
Zheng, J.; Ben-Zion, Y.; Zhu, L.; Ross, Z.
2013-12-01
We develop and apply a method to invert earthquake seismograms for source properties using a general tensor representation and 3D Green's functions. The method employs (i) a general representation of earthquake potency/moment tensors with double couple (DC), compensated linear vector dipole (CLVD), and isotropic (ISO) components, and (ii) a corresponding generalized CAP (gCap) scheme where the continuous wave trains are broken into Pnl and surface waves (Zhu & Ben-Zion, 2013). For comparison, we also use the waveform inversion method of Zheng & Chen (2012) and Ammon et al. (1998). Sets of 3D Green's functions are calculated on a grid of 1 km3 using the 3-D community velocity model CVM-4 (Kohler et al. 2003). A bootstrap technique is adopted to establish robustness of the inversion results using the gCap method (Ross & Ben-Zion, 2013). Synthetic tests with 1-D and 3-D waveform calculations show that the source tensor inversion procedure is reasonably reliable and robust. As initial application, the method is used to investigate source properties of the March 11, 2013, Mw=4.7 earthquake on the San Jacinto fault using recordings of ~45 stations up to ~0.2Hz. Both the best fitting and most probable solutions include ISO component of ~1% and CLVD component of ~0%. The obtained ISO component, while small, is found to be a non-negligible positive value that can have significant implications for the physics of the failure process. Work on using higher frequency data for this and other earthquakes is in progress.
-
Hu, Wenjun; Chung, Fu-Lai; Wang, Shitong
2012-03-01
Although pattern classification has been extensively studied in the past decades, how to effectively solve the corresponding training on large datasets is a problem that still requires particular attention. Many kernelized classification methods, such as SVM and SVDD, can be formulated as the corresponding quadratic programming (QP) problems, but computing the associated kernel matrices requires O(n2)(or even up to O(n3)) computational complexity, where n is the size of the training patterns, which heavily limits the applicability of these methods for large datasets. In this paper, a new classification method called the maximum vector-angular margin classifier (MAMC) is first proposed based on the vector-angular margin to find an optimal vector c in the pattern feature space, and all the testing patterns can be classified in terms of the maximum vector-angular margin ρ, between the vector c and all the training data points. Accordingly, it is proved that the kernelized MAMC can be equivalently formulated as the kernelized Minimum Enclosing Ball (MEB), which leads to a distinctive merit of MAMC, i.e., it has the flexibility of controlling the sum of support vectors like v-SVC and may be extended to a maximum vector-angular margin core vector machine (MAMCVM) by connecting the core vector machine (CVM) method with MAMC such that the corresponding fast training on large datasets can be effectively achieved. Experimental results on artificial and real datasets are provided to validate the power of the proposed methods. Copyright © 2011 Elsevier Ltd. All rights reserved.
-
Cericato, G O; Bittencourt, M A V; Paranhos, L R
2015-01-01
To perform a systematic review with meta-analysis to answer the question: is the cervical vertebrae maturation index (CVMI) effective to replace hand-wrist radiograph (gold standard) in determining the pubertal growth spurt in patients undergoing bone growth? A search in three databases was performed, in which studies were selected that compared one of the two main assessment methods for cervical vertebrae (Hassel B, Farman AG. Skeletal maturation evaluation using cervical vertebrae. Am J Orthod Dentofacial Orthop 1995; 107: 58-66, or Baccetti T, Franchi L, McNamara JA Jr. An improved version of the cervical vertebral maturation (CVM) method for the assessment of mandibular growth. Angle Orthod 2002; 72: 316-23) to a carpal assessment method. The main methodological data from each of the texts were collected and tabulated after. Later, the meta-analysis of the correlation coefficients obtained was performed. 19 articles were selected from an initial 206 articles collected. Regardless of the method used, the results of the meta-analysis showed that every article selected presented a positive correlation between skeletal maturation assessment performed by cervical vertebrae and carpal methods, with discrepancy of values between genders indicating higher correlation for the female gender (0.925; 0.878) than for the male (0.879; 0.842). When the assessment was performed without gender separation, correlation was significant (0.592; 0.688) but lower in the cases when genders were separated. With the results of this meta-analysis, it is safe to affirm that both CVMIs used in the present study are reliable to replace the hand-wrist radiograph in predicting the pubertal growth spurt, considering that the highest values were found in female samples, especially in the method by Hassel and Farman.
-
NASA Technical Reports Server (NTRS)
Pamnani, M. B.; Chen, S.; Haddy, F. J.; Yuan, C.; Mo, Z.
1998-01-01
We have examined the role of plasma Na+-K+ pump inhibitor (SPI) in the hypertension of streptozotocin induced insulin dependent diabetes (IDDM) in reduced renal mass rats. The increase in blood pressure (BP) was associated with an increase in extracellular fluid volume (ECFV), and SPI and a decrease in myocardial Na+,K+ATPase (NKA) activity, suggesting that increased SPI, which inhibits cardiovascular muscle (CVM) cell NKA activity, may be involved in the mechanism of IDDM-hypertension. In a second study, using prolonged suspension resulted in a decrease in cardiac NKA activity, suggesting that cardiovascular deconditioning following space flight might in part result from insufficient SPI.
-
Seagraves, Nikki J.; McBride, Kim L.
2012-01-01
Maternal phenylketonuria (MPKU) is a syndrome including cardiovascular malformations (CVMs), microcephaly, intellectual impairment, and small for gestational age, caused by in-utero exposure to elevated serum phenylalanine (Phe) due to PKU in the mother. It is becoming a public health concern as more women with PKU reach child bearing age. Although a mouse model of PKU, BTBR Pahenu2, has been available for 20 years, it has not been well utilized for studying MPKU. We used this model to delineate critical parameters in Phe cardiovascular teratogenicity and study the effect of genetic background. Dosing and timing experiments were performed with the BTBR Pahenu2 mouse. A dose response curve was noted, with CVM rates at maternal serum Phe levels <360 μM (control), 360 – 600 μM (low), 600 – 900 μM (mid), and >900μM (high) of 11.86%, 16.67%, 30.86%, and 46.67% respectively. A variety of CVMs were noted on the BTBR background, including double outlet right ventricle (DORV), aortic arch artery (AAA)abnormalities, and ventricular septal defects (VSDs). Timed exposure experiments identified a teratogenic window from embryonic day 8.5-13.5, with higher rates of conotruncal and valve defects occurring in early exposure time and persistent truncus arteriosus (PTA) and aortic arch branching abnormalities occurring with late exposure. Compared to the BTBR strain, N10+ Pahenu2 congenics on the C3H/HeJ background had higher rates of CVMs in general and propensity to left ventricular outflow tract (LVOT) malformations, while the C57B/L6 background had similar CVM rates but predominately AAA abnormalities. We have delineated key parameters of Phe cardiovascular teratogenicity, demonstrated the utility of this MPKU model on different mouse strains, and shown how genetic background profoundly affects the phenotype. PMID:22951387
-
Fritz, Sébastien; Capitan, Aurelien; Djari, Anis; Rodriguez, Sabrina C.; Barbat, Anne; Baur, Aurélia; Grohs, Cécile; Weiss, Bernard; Boussaha, Mekki; Esquerré, Diane; Klopp, Christophe; Rocha, Dominique; Boichard, Didier
2013-01-01
The regular decrease of female fertility over time is a major concern in modern dairy cattle industry. Only half of this decrease is explained by indirect response to selection on milk production, suggesting the existence of other factors such as embryonic lethal genetic defects. Genomic regions harboring recessive deleterious mutations were detected in three dairy cattle breeds by identifying frequent haplotypes (>1%) showing a deficit in homozygotes among Illumina Bovine 50k Beadchip haplotyping data from the French genomic selection database (47,878 Holstein, 16,833 Montbéliarde, and 11,466 Normande animals). Thirty-four candidate haplotypes (p<10−4) including previously reported regions associated with Brachyspina, CVM, HH1, and HH3 in Holstein breed were identified. Haplotype length varied from 1 to 4.8 Mb and frequencies from 1.7 up to 9%. A significant negative effect on calving rate, consistent in heifers and in lactating cows, was observed for 9 of these haplotypes in matings between carrier bulls and daughters of carrier sires, confirming their association with embryonic lethal mutations. Eight regions were further investigated using whole genome sequencing data from heterozygous bull carriers and control animals (45 animals in total). Six strong candidate causative mutations including polymorphisms previously reported in FANCI (Brachyspina), SLC35A3 (CVM), APAF1 (HH1) and three novel mutations with very damaging effect on the protein structure, according to SIFT and Polyphen-2, were detected in GART, SHBG and SLC37A2 genes. In conclusion, this study reveals a yet hidden consequence of the important inbreeding rate observed in intensively selected and specialized cattle breeds. Counter-selection of these mutations and management of matings will have positive consequences on female fertility in dairy cattle. PMID:23762392
-
Lai, Eddie Hsiang-Hua; Chang, Jenny Zwei-Chieng; Jane Yao, Chung-Chen; Tsai, Shih-Jaw; Liu, Jen-Pei; Chen, Yi-Jane; Lin, Chun-Pin
2008-07-01
The age at menarche reflects a pubertal girl's physiologic maturity. The aims of this study were to evaluate the relationship between the age at menarche and skeletal maturation in female orthodontic patients. Hand-wrist radiographs and lateral cephalometric radiographs from 304 adolescent female subjects (age, 8-18.9 years) were selected from the files of the Department of Orthodontics, National Taiwan University Hospital (NTUH). Hand-wrist bone maturation stages were assessed using the NTUH Skeletal Maturation Index (NTUH-SMI). Cervical vertebral maturation stages (CVMS) were determined using the latest CVMS Index. Menarcheal ages were self-reported by the patients and verified by the patients' mothers. The relationships between the NTUH-SMI or CVM stages and menarcheal status were investigated. More than 90% of the 148 subjects who had already attained menstruation had skeletal maturation beyond the NTUH-SMI stage four or CVMS III. However, the subjects who had never experienced menarche mostly had skeletal maturation before NTUH-SMI stage five or CVMS IV. During the period of orthodontic treatment, 19 females experienced their menarche. The mean age at menarche for the 167 female patients in total was 11.97 years. In average, menarche occurred between NTUH-SMI stages four and five or between CVM stages III and IV. The percentage of girls with menses increased from 1.2% at age 9 to 6.6% at age 10, 39.5% at age 11, 81.4% at age 12, 97% at age 13, and 100% at age 14. Compared with the results obtained 20 years previously, we found a downward shift of 0.47 years per decade for the mean age at menarche in female orthodontic patients. The majority of female orthodontic patients have passed the pubertal growth spurt when they experience their menarche. Menarche usually follows the pubertal growth spurt by about 1 year and occurs after NTUH-SMI stage four or CVMS III.
-
Purushotham, Chetana B; Robin, V V
2016-10-01
Various mechanisms of isolation can structure populations and result in cultural and genetic differentiation. Similar to genetic markers, for songbirds, culturally transmitted sexual signals such as breeding song can be used as a measure of differentiation as songs can also be impacted by geographic isolation resulting in population-level differences in song structure. Several studies have found differences in song structure either across ancient geographic barriers or across contemporary habitat barriers owing to deforestation. However, very few studies have examined the effect of both ancient barriers and recent deforestation in the same system. In this study, we examined the geographic variation in song structure across six populations of the White-bellied Shortwing, a threatened and endemic songbird species complex found on isolated mountaintops or "sky islands" of the Western Ghats. While some sky islands in the system are isolated by ancient valleys, others are separated by deforestation. We examined 14 frequency and temporal spectral traits and two syntax traits from 835 songs of 38 individuals across the six populations. We identified three major song clusters based on a discriminant model of spectral traits, degree of similarity of syntax features, as well as responses of birds to opportunistic playback. However, some traits like complex vocal mechanisms (CVM), relating to the use of syrinxes, clearly differentiated both ancient and recently fragmented populations. We suggest that CVMs may have a cultural basis and can be used to identify culturally isolated populations that cannot be differentiated using genetic markers or commonly used frequency-based song traits. Our results demonstrate the use of bird songs to reconstruct phylogenetic groups and impacts of habitat fragmentation even in complex scenarios of historic and contemporary isolation.
-
CyberShake: Running Seismic Hazard Workflows on Distributed HPC Resources
NASA Astrophysics Data System (ADS)
Callaghan, S.; Maechling, P. J.; Graves, R. W.; Gill, D.; Olsen, K. B.; Milner, K. R.; Yu, J.; Jordan, T. H.
2013-12-01
As part of its program of earthquake system science research, the Southern California Earthquake Center (SCEC) has developed a simulation platform, CyberShake, to perform physics-based probabilistic seismic hazard analysis (PSHA) using 3D deterministic wave propagation simulations. CyberShake performs PSHA by simulating a tensor-valued wavefield of Strain Green Tensors, and then using seismic reciprocity to calculate synthetic seismograms for about 415,000 events per site of interest. These seismograms are processed to compute ground motion intensity measures, which are then combined with probabilities from an earthquake rupture forecast to produce a site-specific hazard curve. Seismic hazard curves for hundreds of sites in a region can be used to calculate a seismic hazard map, representing the seismic hazard for a region. We present a recently completed PHSA study in which we calculated four CyberShake seismic hazard maps for the Southern California area to compare how CyberShake hazard results are affected by different SGT computational codes (AWP-ODC and AWP-RWG) and different community velocity models (Community Velocity Model - SCEC (CVM-S4) v11.11 and Community Velocity Model - Harvard (CVM-H) v11.9). We present our approach to running workflow applications on distributed HPC resources, including systems without support for remote job submission. We show how our approach extends the benefits of scientific workflows, such as job and data management, to large-scale applications on Track 1 and Leadership class open-science HPC resources. We used our distributed workflow approach to perform CyberShake Study 13.4 on two new NSF open-science HPC computing resources, Blue Waters and Stampede, executing over 470 million tasks to calculate physics-based hazard curves for 286 locations in the Southern California region. For each location, we calculated seismic hazard curves with two different community velocity models and two different SGT codes, resulting in over 1100 hazard curves. We will report on the performance of this CyberShake study, four times larger than previous studies. Additionally, we will examine the challenges we face applying these workflow techniques to additional open-science HPC systems and discuss whether our workflow solutions continue to provide value to our large-scale PSHA calculations.
-
Tricco, Andrea C; Strifler, Lisa; Veroniki, Areti-Angeliki; Yazdi, Fatemeh; Khan, Paul A; Scott, Alistair; Ng, Carmen; Antony, Jesmin; Mrklas, Kelly; D'Souza, Jennifer; Cardoso, Roberta; Straus, Sharon E
2015-10-26
To compare the safety and effectiveness of long-acting β-antagonists (LABA), long-acting antimuscarinic agents (LAMA) and inhaled corticosteroids (ICS) for managing chronic obstructive pulmonary disease (COPD). Systematic review and network meta-analysis (NMA). 208 randomised clinical trials (RCTs) including 134,692 adults with COPD. LABA, LAMA and/or ICS, alone or in combination, versus each other or placebo. The proportion of patients with moderate-to-severe exacerbations. The number of patients experiencing mortality, pneumonia, serious arrhythmia and cardiovascular-related mortality (CVM) were secondary outcomes. NMA was conducted including 20 RCTs for moderate-to-severe exacerbations for 26,141 patients with an exacerbation in the past year. 32 treatments were effective versus placebo including: tiotropium, budesonide/formoterol, salmeterol, indacaterol, fluticasone/salmeterol, indacaterol/glycopyrronium, tiotropium/fluticasone/salmeterol and tiotropium/budesonide/formoterol. Tiotropium/budesonide/formoterol was most effective (99.2% probability of being the most effective according to the Surface Under the Cumulative RAnking (SUCRA) curve). NMA was conducted on mortality (88 RCTs, 97 526 patients); fluticasone/salmeterol was more effective in reducing mortality than placebo, formoterol and fluticasone alone, and was the most effective (SUCRA=71%). NMA was conducted on CVM (37 RCTs, 55,156 patients) and the following were safest: salmeterol versus each OF placebo, tiotropium and tiotropium (Soft Mist Inhaler (SMR)); fluticasone versus tiotropium (SMR); and salmeterol/fluticasone versus tiotropium and tiotropium (SMR). Triamcinolone acetonide was the most harmful (SUCRA=81%). NMA was conducted on pneumonia occurrence (54 RCTs, 61 551 patients). 24 treatments were more harmful, including 2 that increased risk of pneumonia versus placebo; fluticasone and fluticasone/salmeterol. The most harmful agent was fluticasone/salmeterol (SUCRA=89%). NMA was conducted for arrhythmia; no statistically significant differences between agents were identified. Many inhaled agents are available for COPD, some are safer and more effective than others. Our results can be used by patients and physicians to tailor administration of these agents. PROSPERO # CRD42013006725. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/
-
NASA Astrophysics Data System (ADS)
Klemperer, S. L.; Barak, S.
2016-12-01
We present a new 2D shear-wave velocity model of the crust and upper-mantle across the Salton Trough, southern California, obtained by jointly inverting our new dataset of receiver functions and our previously published Rayleigh-wave group-velocity model (Barak et al., G-cubed, 2015), obtained from ambient-noise tomography. Our results show an upper-mantle low-velocity zone (LVZ) with Vs ≤4.2 km/s extending from the Elsinore Fault to the Sand Hills Fault, that together bracket the full width of major San Andreas dextral motion since its inception 6 Ma b.p., and underlying the full width of low topography of the Imperial Valley and Salton Trough. The lateral extent of the LVZ is coincident with the lateral extent of an upper-mantle anisotropic region interpreted as a zone of SAF-parallel melt pockets (Barak & Klemperer, Geology, 2016). The shallowest part of the LVZ is 40 km depth, coincident with S-receiver function images. The western part of the LVZ, between the Elsinore and San Jacinto faults (the region of greatest modern dextral slip), appears to continue to significantly greater depth; but a puzzling feature of our preliminary models is that the eastern part of the LVZ, from the San Jacinto Fault to the Sand Hills Fault, appears to be underlain by more-normalvelocity upper mantle (Vs ≥ 4.5 km/s) below 75 km depth. We compare our model to the current SCEC community models CVM-H and CVM-S, and to P-wave velocity models obtained by the active-source Salton Sea Imaging Project (SSIP). The hypothesized lower-crustal low-velocity zone beneath the Salton Trough in our previous model (Barak et al., G-cubed, 2015), there interpreted as a region of partial melt, is not supported by our new modeling. Melt may be largely absent from the lower crust of the Salton trough; but appears required in the upper mantle at depths as shallow as 40 km.
-
Acceptability and willingness to pay for telemedicine services in Enugu state, southeast Nigeria
Arize, Ifeyinwa; Onwujekwe, Obinna
2017-01-01
Background This study examines the level of awareness, acceptability and consumers’ willingness to pay (WTP) for telemedicine services using the contingent valuation method (CVM). This work is important as it elicits the value that consumers attach to telemedicine given there is a gap in this knowledge in many sub-Saharan countries such as in Nigeria. Methods The study was based on primary data obtained through an interviewer-administered questionnaire of 370 individuals including both males and females from 25 years and over, to collect data on respondents’ awareness of, acceptability of, and WTP for telemedicine, using the bidding game question format. A socioeconomic status (SES) index was created, based on information on household assets, and was used to categorize respondents into SES quartiles. The data were analyzed using a combination of descriptive techniques, logistics and the Tobit regression model (Tobit Type 1) methods. Results The study found that majority of the people (58.9%) had no knowledge of telemedicine. However, 48.7% of the respondents were willing to pay for telemedicine. The mean WTP for a telemedicine was US$2.04 for each visit. Tobit regression analysis showed that respondents’ socioeconomic status (SES) was the main statistically significant variable that explained their WTP for telemedicine. Conclusion The study has shown that there is a low-level awareness of and WTP for telemedicine services in Enugu State, South East of Nigeria. The finding of a positive relationship between SES and WTP implies that the poor may not be able to pay for telemedicine and may need government subsidies to be able to benefit from such service. Also, government and their partners need to undertake wide scale campaign before the introduction of telemedicine. PMID:29942606
-
NASA Astrophysics Data System (ADS)
Xu, Guangping; Wang, Jiasong
2017-10-01
Two dynamical models, the traditional method of moments coupled model (MCM) and Taylor-series expansion method of moments coupled model (TECM) for particle dispersion distribution and gravitation deposition are developed in three-dimensional ventilated environments. The turbulent airflow field is modeled with the renormalization group (RNG) k-ε turbulence model. The particle number concentration distribution in a ventilated room is obtained by solving the population balance equation coupled with the airflow field. The coupled dynamical models are validated using experimental data. A good agreement between the numerical and experimental results can be achieved. Both models have a similar characteristic for the spatial distribution of particle concentration. Relative to the MCM model, the TECM model presents a more close result to the experimental data. The vortex structure existed in the air flow makes a relative large concentration difference at the center region and results in a spatial non-uniformity of concentration field. With larger inlet velocity, the mixing level of particles in the room is more uniform. In general, the new dynamical models coupled with computational fluid dynamics (CFD) in the current study provide a reasonable and accurate method for the temporal and spatial evolution of particles effected by the deposition and dispersion behaviors. In addition, two ventilation modes with different inlet velocities are proceeded to study the effect on the particle evolution. The results show that with the ceiling ventilation mode (CVM), the particles can be better mixed and the concentration level is also higher. On the contrast, with the side ceiling ventilation mode (SVM), the particle concentration has an obvious stratified distribution with a relative lower level and it makes a much better environment condition to the human exposure.
-
Boundary lubrication of formulated C-ethers in air to 300 C. 2: Organic acid additives
NASA Technical Reports Server (NTRS)
Jones, W. R., Jr.
1973-01-01
Friction and wear measurements were made on CVM M-50 steel lubricated with three C-ether (modified polyphenyl ether) formulations in dry and moist air. Results were compared to those obtained with a formulated Type 2 ester and the C-ether base fluid. A ball-on-disk sliding friction apparatus was used. Experimental conditions were a 1-kilogram load, a 17-meter/minute surface speed, and a 25 to 300 C (77 to 572 F) disk temperature range. The three C-ether formulations yielded better boundary lubricating characteristics than the Type 2 ester under most test conditions. All C-ether formulations exhibited higher friction coefficients than the ester from 150 to 300 C (302 to 572 F) and similar or lower values from 25 to 150 C (77 to 302 F).
-
NASA Astrophysics Data System (ADS)
Swindell, Paul; Doyle, Jon; Roach, Dennis
2017-02-01
The Federal Aviation Administration (FAA) started a research program in structural health monitoring (SHM) in 2011. The program's goal was to understand the technical gaps of implementing SHM on commercial aircraft and the potential effects on FAA regulations and guidance. The program evolved into a demonstration program consisting of a team from Sandia National Labs Airworthiness Assurance NDI Center (AANC), the Boeing Corporation, Delta Air Lines, Structural Monitoring Systems (SMS), Anodyne Electronics Manufacturing Corp (AEM) and the FAA. This paper will discuss the program from the selection of the inspection problem, the SHM system (Comparative Vacuum Monitoring-CVM) that was selected as the inspection solution and the testing completed to provide sufficient data to gain the first approved use of an SHM system for routine maintenance on commercial US aircraft.
-
Lubricant and additive effects on spur gear fatigue life
NASA Technical Reports Server (NTRS)
Townsend, D. P.; Zaretsky, E. V.; Scibbe, H. W.
1985-01-01
Spur gear endurance tests were conducted with six lubricants using a single lot of consumable-electrode vacuum melted (CVM) AISI 9310 spur gears. The sixth lubricant was divided into four batches each of which had a different additive content. Lubricants tested with a phosphorus-type load carrying additive showed a statistically significant improvement in life over lubricants without this type of additive. The presence of sulfur type antiwear additives in the lubricant did not appear to affect the surface fatigue life of the gears. No statistical difference in life was produced with those lubricants of different base stocks but with similar viscosity, pressure-viscosity coefficients and antiwear additives. Gears tested with a 0.1 wt % sulfur and 0.1 wt % phosphorus EP additives in the lubricant had reactive films that were 200 to 400 (0.8 to 1.6 microns) thick.
-
Effect of five lubricants on life of AISI 9310 spur gears
NASA Technical Reports Server (NTRS)
Townsend, D. P.; Zaretsky, E. V.
1985-01-01
Spur-gear surface fatigue tests were conducted with five lubricants using a single lot of consumable-electrode vacuum melted (CVM) AISI 9310 spur gears. The lot of gears was divided into five groups, each of which was tested with a different lubricant. The test lubricants are classified as either a synthetic hydrocarbon, mineral oil, or ester-based lubricant. All five lubricants have imilar viscosity and pressure-viscosity coefficients. A pentaerythritol base stock without sufficient antiwear additives produced a surface fatigue life pproximately 22 percent that of the same base stock with chlorine and phosphorus type additives. The presence of sulfur type antiwear additives in the lubricant did not appear to affect the surface fatigue life of the gears tested. No statistical difference in the 10-percent surface fatigue life was produced with four of the five lubricants.
-
Riverine based eco-tourism: Trinity River non-market benefits estimates
Douglas, A.J.; Taylor, J.G.
1998-01-01
California's Central Valley Project (CVP) was approved by voters in a statewide referendum in 1933. CVP referendum approval initiated funding for construction of important water development projects that had far reaching effects on regional water supplies. The construction of Trinity Dam in 1963 and the subsequent transbasin diversion of Trinity River flow was one of several CVP projects that had noteworthy adverse environmental and regional economic impacts. The Trinity River is the largest tributary of the Klamath River, and has its headwaters in the Trinity Alps of north-central California. After the construction of Trinity Dam in 1963, 90% of the Trinity River flow at Lewiston was moved to the Sacramento River via the Clear Creek Tunnel. Before 1963, the Trinity River was a major recreation resource of Northern California. The loss of streamflow has had a marked adverse impact on Trinity River-related recreation activities and the size and robustness of Trinity River salmon, steelhead, shad, and sturgeon runs. Trinity River water produces hydropower during its transit via Bureau of Reclamation canals and pumps to the northern San Joaquin Valley, where it is used for irrigated agriculture. The benefits provided by Trinity River instream flow-related environmental amenities were estimated with the travel cost method (TCM). Trinity River non-market benefits are about $406 million per annum, while the social cost of sending water down the Trinity River ranges from $17 to $42 million per annum, depending on the exact flow. We also discuss the relative magnitude of Trinity River survey data contingent value method (CVM) benefits estimates.
-
Li, Sheng; Guo, Zong-xiang; Yang, Huai-yu; Yang, Zheng-yong
2009-12-01
Pond aquaculture has existed in China for thousands of years, which has not only contributed great economic value, but also presented cultural value for human beings. With the development and upgrading of Chinese economy and culture, these values will be highlighted further. To evaluate the cultural service value of pond aquaculture ecosystem would provide a scientific base to the policy-making to avoid or reduce the wrong design-making or avoid the policy-malfunction, and also, to promote the development of aquaculture and related recreational fishing industry, increase the added value of aquaculture and the income of fish-farmers, and promote the economic development of rural area. Based on the survey data from the aquaculture ponds in the water conservation area of Dianshan Lake in Qingpu District of Shanghai and the related statistical data, the cultural service value including recreational value and existence value of the aquaculture pond ecosystem in the area was estimated by means of travel cost method (TCM) and contingent valuation method (CVM). The total cultural service value of this ecosystem was about 213 million Yuan x a(-1) or 231296. 69 Yuan x hm(-2) x a(-1), being 5. 25 times of the market value of aquaculture products, among which, recreational value was about 189 million Yuan x a(-1), and existence value was about 24 million Yuan x a(-1). It was suggested that in the construction of new rural areas of Shanghai, sufficient attention should be paid on the full play of the cultural service value of aquaculture pond ecosystem.
-
An introduction to analytical methods for the postmarketing surveillance of veterinary vaccines.
Siev, D
1999-01-01
Any analysis of spontaneous AER data must consider the many biases inherent in the observation and reporting of vaccine adverse events. The absence of a clear probability structure requires statistical procedures to be used in a spirit of exploratory description rather than definitive confirmation. The extent of such descriptions should be temperate, without the implication that they extend to parent populations. It is important to recognize the presence of overdispersion in selecting methods and constructing models. Important stochastic or systematic features of the data may always be unknown. Our attempts to delineate what constitutes an AER have not eliminated all the fuzziness in its definition. Some count every event in a report as a separate AER. Besides confusing the role of event and report, this introduces a complex correlational structure, since multiple event descriptions received in a single report can hardly be considered independent. The many events described by one reporter would then become inordinately weighted. The alternative is to record an AER once, regardless of how many event descriptions it includes. As a practical compromise, many regard the simultaneous submission of several report forms by one reporter as a single AER, and the next submission by that reporter as another AER. This method is reasonable when reporters submit AERs very infrequently. When individual reporters make frequent reports, it becomes difficult to justify the inconsistency of counting multiple events as a single AER when they are submitted together, but as separate AERs when they are reported at different times. While either choice is imperfect, the latter approach is currently used by the USDA and its licensed manufacturers in developing a mandatory postmarketing surveillance system for veterinary immunobiologicals in the United States. Under the proposed system, summaries of an estimated 10,000 AERs received annually by the manufacturers would be submitted to the USDA. In quantitative summaries, AERs received from lay consumers are usually weighted equally with those received from veterinary health professionals, although arguments have been advanced for separate classifications. The emphasis on AER rate estimation differentiates the surveillance of veterinary vaccines by the USDA CVB from the surveillance of veterinary drugs as practiced by the Food and Drug Administration (FDA) Center for Veterinary Medicine (CVM). The FDA CVM does, in fact, perform a retrodictive causality assessment for individual AERs (Parkhie et al., 1995). This distinction reflects the differences between vaccines and drugs, as well as the difference in regulatory philosophy between the FDA and the USDA. The modified Kramer algorithm (Kramer et al., 1979) used by the FDA relies on features more appropriate to drug therapy than vaccination, such as an ongoing treatment regimen which allows evaluation of the response to dechallenge and rechallenge. In tracking AERs, the FDA has emphasized the inclusion of clinical manifestations on labels and inserts, while the USDA has been reluctant to have such information appear in product literature or to use postmarketing data for this purpose. The potential for the misuse of spontaneous AER data is great. Disinformation is likely when the nature of this type of data is misunderstood and inappropriate analytical methods blindly employed. A greater danger lies in the glib transformation of AER data into something else entirely. Since approval before publication is not required, advertisements for veterinary vaccines appear with claims such as "over 3 million doses, 99.9905% satisfaction rating," or "11,500,000 doses, 99.98% reaction free." These claims, presumably based on spontaneous AERs, are almost fraudulent in their deceptiveness. Are we to suppose that 11.5 million vaccinations were observed for reactions? In comparing the two advertisements, we find the second presumed AER rate is double the first. (ABSTRACT TRU
-
Study of Patients' Willingness to Pay for a Cure of Chronic Obstructive Pulmonary Disease in Taiwan.
Chen, Yi-Ting; Ying, Yung-Hsiang; Chang, Koyin; Hsieh, Ya-Hui
2016-03-01
Chronic Obstructive Pulmonary Disease (COPD) is one of the fastest growing causes of death worldwide. However, few studies, if any, have been conducted that have investigated patient profiles in Asia. This paper analyzes patient willingness to pay (WTP) as a function of patient disease severity, health-related quality of life (HRQL), and smoking behavior in Taiwan. A cross-sectional survey was conducted using in-person interviews with COPD patients. A hypothetical scenario was designed and presented to ascertain each subject's willingness to pay (WTP) for a cure for COPD. A survey of subjects with COPD was performed in Taiwan. The contingent valuation method (CVM) was employed to measure patient financial burden, which was analyzed along with covariates that included various types of health-related quality of life (HRQL), severity level, and demographic background. Multivariate regression and simulation methods were employed for analysis. A total of 142 subjects were interviewed, with an average annual WTP of approximately $1422 USD (or 42,662.37 NTD, New Taiwan Dollars). The annual WTP for patients 55 years of age or younger, $5709.06, was the highest and equivalent to approximately one-third of Taiwan average annual personal income or quadruple the spending amount of the Taiwan National Bureau of Health Insurance (NBHI) for each COPD patient. Current cigarette smokers were willing to pay a substantially higher amount than former smokers and nonsmokers, which reflects a psychological desire for redemption in COPD patients. The results of this study provide directions for the relevant authorities regarding the alleviation of suffering as a result of COPD. Appropriate health promotion measures, such as measures to reduce tobacco usage, early diagnosis, and active treatment, may be necessary to contain the escalating costs related to COPD and to prevent this epidemic from worsening.
-
VMCast: A VM-Assisted Stability Enhancing Solution for Tree-Based Overlay Multicast
Gu, Weidong; Zhang, Xinchang; Gong, Bin; Zhang, Wei; Wang, Lu
2015-01-01
Tree-based overlay multicast is an effective group communication method for media streaming applications. However, a group member’s departure causes all of its descendants to be disconnected from the multicast tree for some time, which results in poor performance. The above problem is difficult to be addressed because overlay multicast tree is intrinsically instable. In this paper, we proposed a novel stability enhancing solution, VMCast, for tree-based overlay multicast. This solution uses two types of on-demand cloud virtual machines (VMs), i.e., multicast VMs (MVMs) and compensation VMs (CVMs). MVMs are used to disseminate the multicast data, whereas CVMs are used to offer streaming compensation. The used VMs in the same cloud datacenter constitute a VM cluster. Each VM cluster is responsible for a service domain (VMSD), and each group member belongs to a specific VMSD. The data source delivers the multicast data to MVMs through a reliable path, and MVMs further disseminate the data to group members along domain overlay multicast trees. The above approach structurally improves the stability of the overlay multicast tree. We further utilized CVM-based streaming compensation to enhance the stability of the data distribution in the VMSDs. VMCast can be used as an extension to existing tree-based overlay multicast solutions, to provide better services for media streaming applications. We applied VMCast to two application instances (i.e., HMTP and HCcast). The results show that it can obviously enhance the stability of the data distribution. PMID:26562152
-
VMCast: A VM-Assisted Stability Enhancing Solution for Tree-Based Overlay Multicast.
Gu, Weidong; Zhang, Xinchang; Gong, Bin; Zhang, Wei; Wang, Lu
2015-01-01
Tree-based overlay multicast is an effective group communication method for media streaming applications. However, a group member's departure causes all of its descendants to be disconnected from the multicast tree for some time, which results in poor performance. The above problem is difficult to be addressed because overlay multicast tree is intrinsically instable. In this paper, we proposed a novel stability enhancing solution, VMCast, for tree-based overlay multicast. This solution uses two types of on-demand cloud virtual machines (VMs), i.e., multicast VMs (MVMs) and compensation VMs (CVMs). MVMs are used to disseminate the multicast data, whereas CVMs are used to offer streaming compensation. The used VMs in the same cloud datacenter constitute a VM cluster. Each VM cluster is responsible for a service domain (VMSD), and each group member belongs to a specific VMSD. The data source delivers the multicast data to MVMs through a reliable path, and MVMs further disseminate the data to group members along domain overlay multicast trees. The above approach structurally improves the stability of the overlay multicast tree. We further utilized CVM-based streaming compensation to enhance the stability of the data distribution in the VMSDs. VMCast can be used as an extension to existing tree-based overlay multicast solutions, to provide better services for media streaming applications. We applied VMCast to two application instances (i.e., HMTP and HCcast). The results show that it can obviously enhance the stability of the data distribution.
-
Study of Patients’ Willingness to Pay for a Cure of Chronic Obstructive Pulmonary Disease in Taiwan
Chen, Yi-Ting; Ying, Yung-Hsiang; Chang, Koyin; Hsieh, Ya-Hui
2016-01-01
Objectives: Chronic Obstructive Pulmonary Disease (COPD) is one of the fastest growing causes of death worldwide. However, few studies, if any, have been conducted that have investigated patient profiles in Asia. This paper analyzes patient willingness to pay (WTP) as a function of patient disease severity, health-related quality of life (HRQL), and smoking behavior in Taiwan. Study Design: A cross-sectional survey was conducted using in-person interviews with COPD patients. A hypothetical scenario was designed and presented to ascertain each subject’s willingness to pay (WTP) for a cure for COPD. Methods: A survey of subjects with COPD was performed in Taiwan. The contingent valuation method (CVM) was employed to measure patient financial burden, which was analyzed along with covariates that included various types of health-related quality of life (HRQL), severity level, and demographic background. Multivariate regression and simulation methods were employed for analysis. Results: A total of 142 subjects were interviewed, with an average annual WTP of approximately $1422 USD (or 42,662.37 NTD, New Taiwan Dollars). The annual WTP for patients 55 years of age or younger, $5709.06, was the highest and equivalent to approximately one-third of Taiwan average annual personal income or quadruple the spending amount of the Taiwan National Bureau of Health Insurance (NBHI) for each COPD patient. Current cigarette smokers were willing to pay a substantially higher amount than former smokers and nonsmokers, which reflects a psychological desire for redemption in COPD patients. Conclusions: The results of this study provide directions for the relevant authorities regarding the alleviation of suffering as a result of COPD. Appropriate health promotion measures, such as measures to reduce tobacco usage, early diagnosis, and active treatment, may be necessary to contain the escalating costs related to COPD and to prevent this epidemic from worsening. PMID:26938547
-
Endurance and failure characteristics of main-shaft jet engine bearings at 3x10 to the 6th power DN
NASA Technical Reports Server (NTRS)
Bamberger, E. N.; Zaretsky, E. V.; Signer, H.
1976-01-01
Groups of thirty 120-mm bore angular contact ball bearings were endurance tested at a speed of 12,000 and 25,000 rpm and a thrust load of 66 721 N. The bearings were manufactured from a single heat of VIM-VAR AISI M-50 steel. At 1.44X1 million and 3.0x1 million DN, 84 483 and 74 800 bearing test hours were accumulated, respectively. Test results were compared with similar bearings made from CVM AISI M-50 steel run under the same conditions. Bearing lives at speeds of 3x1 million DN with the VIM-VAR AISI M-50 steel were nearly equivalent to those obtained at lower speeds. A combined processing and material life factor of 44 was found for VIM-VAR AISI M-50 steel. Continuous running after a spall has occurred at 3.0x1 million DN can result in a destructive fracture of the bearing inner race.
-
NASA Astrophysics Data System (ADS)
Yoo, J.; Kong, K.
2010-12-01
This research the findings from a discrete-choice experiment designed to estimate the economic benefits associated with the Anyangcheon watershed improvements in Rep. of Korea. The Anyangcheon watershed has suffered from streamflow depletion and poor stream quality, which often negatively affect instream and near-stream ecologic integrity, as well as water supply. Such distortions in the hydrologic cycle mainly result from rapid increase of impermeable area due to urbanization, decreases of baseflow runoff due to groundwater pumping, and reduced precipitation inputs driven by climate forcing. As well, combined sewer overflows and increase of non-point source pollution from urban regions decrease water quality. The appeal of choice experiments (CE) in economic analysis is that it is based on random utility theory (McFadden, 1974; Ben-Akiva and Lerman, 1985). In contrast to contingent valuation method (CVM), which asks people to choose between a base case and a specific alternative, CE asks people to choice between cases that are described by attributes. The attributes of this study were selected from hydrologic vulnerability components that represent flood damage possibility, instreamflow depletion, water quality deterioration, form of the watershed and tax. Their levels were divided into three grades include status quo. Two grades represented the ideal conditions. These scenarios were constructed from a 35 orthogonal main effect design. This design resulted in twenty-seven choice sets. The design had nine different choice scenarios presented to each respondent. The most popular choice models in use are the conditional logit (CNL). This model provides closed-form choice probability calculation. The shortcoming of CNL comes from irrelevant alternatives (IIA). In this paper, the mixed logit (ML) is applied to allow the coefficient’s variation for random taste heterogeneity in the population. The mixed logit model(with normal distributions for the attributes) fit the data best, indication that allowing for both heterogeneous preferences across households and correlation between repeated choices may represent actual choice behaviors best of all the estimated models. The annual benefits to improve of the Anyancheon watershed for 1% improvement of each attribute was 406.7 billion Won(0.34 billion USD). This study is expected to contribute to the decision-making process for policy-makers by providing useful methodological framework and quantitative information related to watershed improvement projects.Table 1. Estimated Results of Conditional Logit and Mixed Logit Model 1) t-values are shown in brackets
-
Cervical vertebral maturation of children with orofacial clefts.
Sun, Ling; Li, Wei Ran
2012-11-01
To evaluate the skeletal maturation of male children with orofacial clefts using the cervical vertebral maturation (CVM) method. Case-control study. The School of Stomatology, Peking University. Subjects were 443 boys with cleft lip and/or cleft palate (CL/P) aged 8 to 16 years who were compared with 1772 boys without clefts in an age-matched control group. The 8- to 10-year-old boys of both groups were in CS1. Most of the 11- to 14-year-old boys without CL/P were in CS3 and CS4, though it was not so obvious in boys with CL/P. Most 15- to 16-year-old boys without CL/P were in CS5 and CS6, while there were a lot of boys with CL/P who were still in cervical stages before CS5. Clefts had a significant effect on growth, and boys without CL/P were 1.737 times more likely to have achieved higher cervical stages. From Mann-Whitney test of every age phase, the difference existed in each year of the age range of 11 to 16 years, except from 12 to 13 years (p = .100). In these age phases, the cervical stages of boys with CL/P were lower than those for boys without CL/P. By the age of 14, children with CL/P had a 4.679 times higher risk of delayed CS3, and the 95% confidence interval for the odds ratio was 2.129 to 10.286. Boys with CL/P are at a higher risk of delayed growth period and retarded pubertal growth peak.
-
Lewis, Mary; Shapland, Fiona; Watts, Rebecca
2016-01-01
This study provides the first large scale analysis of the age at which adolescents in medieval England entered and completed the pubertal growth spurt. This new method has implications for expanding our knowledge of adolescent maturation across different time periods and regions. In total, 994 adolescent skeletons (10-25 years) from four urban sites in medieval England (AD 900-1550) were analyzed for evidence of pubertal stage using new osteological techniques developed from the clinical literature (i.e., hamate hook development, cervical vertebral maturation (CVM), canine mineralization, iliac crest ossification, and radial fusion). Adolescents began puberty at a similar age to modern children at around 10-12 years, but the onset of menarche in girls was delayed by up to 3 years, occurring around 15 for most in the study sample and 17 years for females living in London. Modern European males usually complete their maturation by 16-18 years; medieval males took longer with the deceleration stage of the growth spurt extending as late as 21 years. This research provides the first attempt to directly assess the age of pubertal development in adolescents during the 10th-17th centuries. Poor diet, infections, and physical exertion may have contributed to delayed development in the medieval adolescents, particularly for those living in the city of London. This study sheds new light on the nature of adolescence in the medieval period, highlighting an extended period of physical and social transition. © 2015 Wiley Periodicals, Inc.
-
Measurement System Analyses - Gauge Repeatability and Reproducibility Methods
NASA Astrophysics Data System (ADS)
Cepova, Lenka; Kovacikova, Andrea; Cep, Robert; Klaput, Pavel; Mizera, Ondrej
2018-02-01
The submitted article focuses on a detailed explanation of the average and range method (Automotive Industry Action Group, Measurement System Analysis approach) and of the honest Gauge Repeatability and Reproducibility method (Evaluating the Measurement Process approach). The measured data (thickness of plastic parts) were evaluated by both methods and their results were compared on the basis of numerical evaluation. Both methods were additionally compared and their advantages and disadvantages were discussed. One difference between both methods is the calculation of variation components. The AIAG method calculates the variation components based on standard deviation (then a sum of variation components does not give 100 %) and the honest GRR study calculates the variation components based on variance, where the sum of all variation components (part to part variation, EV & AV) gives the total variation of 100 %. Acceptance of both methods among the professional society, future use, and acceptance by manufacturing industry were also discussed. Nowadays, the AIAG is the leading method in the industry.
-
Lu, Tzong-Shi; Yiao, Szu-Yu; Lim, Kenneth; Jensen, Roderick V; Hsiao, Li-Li
2010-07-01
The identification of differences in protein expression resulting from methodical variations is an essential component to the interpretation of true, biologically significant results. We used the Lowry and Bradford methods- two most commonly used methods for protein quantification, to assess whether differential protein expressions are a result of true biological or methodical variations. MATERIAL #ENTITYSTARTX00026; Differential protein expression patterns was assessed by western blot following protein quantification by the Lowry and Bradford methods. We have observed significant variations in protein concentrations following assessment with the Lowry versus Bradford methods, using identical samples. Greater variations in protein concentration readings were observed over time and in samples with higher concentrations, with the Bradford method. Identical samples quantified using both methods yielded significantly different expression patterns on Western blot. We show for the first time that methodical variations observed in these protein assay techniques, can potentially translate into differential protein expression patterns, that can be falsely taken to be biologically significant. Our study therefore highlights the pivotal need to carefully consider methodical approaches to protein quantification in techniques that report quantitative differences.
-
NASA Astrophysics Data System (ADS)
Lü, Xiaozhou; Xie, Kai; Xue, Dongfeng; Zhang, Feng; Qi, Liang; Tao, Yebo; Li, Teng; Bao, Weimin; Wang, Songlin; Li, Xiaoping; Chen, Renjie
2017-10-01
Micro-capacitance sensors are widely applied in industrial applications for the measurement of mechanical variations. The measurement accuracy of micro-capacitance sensors is highly dependent on the capacitance measurement circuit. To overcome the inability of commonly used methods to directly measure capacitance variation and deal with the conflict between the measurement range and accuracy, this paper presents a capacitance variation measurement method which is able to measure the output capacitance variation (relative value) of the micro-capacitance sensor with a continuously variable measuring range. We present the principles and analyze the non-ideal factors affecting this method. To implement the method, we developed a capacitance variation measurement circuit and carried out experiments to test the circuit. The result shows that the circuit is able to measure a capacitance variation range of 0-700 pF linearly with a maximum relative accuracy of 0.05% and a capacitance range of 0-2 nF (with a baseline capacitance of 1 nF) with a constant resolution of 0.03%. The circuit is proposed as a new method to measure capacitance and is expected to have applications in micro-capacitance sensors for measuring capacitance variation with a continuously variable measuring range.
-
Damigos, Dimitris; Menegaki, Maria; Kaliampakos, Dimitris
2016-05-01
Despite the emerging global attention towards promoting waste management policies that reduce environmental impacts and conserve natural resources, landfilling still remains the dominant waste management practice in many parts of the world. Owing to this situation, environmental burdens are bequeathed to and large amounts of potentially valuable materials are lost for future generations. As a means to undo these adverse effects a process known as landfill mining (LFM) could be implemented provided that economic feasibility is ensured. So far, only a few studies have focused on the economic feasibility of LFM from a private point of view and even less studies have attempted to economically justify the need for LMF projects from a social point of view. This paper, aiming to add to the limited literature in the field, presents the results of a survey conducted in a rural district in Greece, by means of the Contingent Valuation method (CVM) in order to estimate society's willingness to pay for LFM programs. According to the empirical survey, more than 95% of the respondents recognize the need for LFM programs. Nevertheless, only one-fourth of the respondents are willing to pay through increased taxes for LFM, owing mainly to economic depression and unemployment. Those who accept the increased tax are willing to pay about €50 per household per year, on average, which results in a mean willingness to pay (WTP) for the entire population under investigation of around €12 per household per year. The findings of this research work provide useful insights about the 'dollar-based' benefits of LFM in the context of social cost-benefit analysis of LFM projects. Yet, it is evident that further research is necessary. Copyright © 2015 Elsevier Ltd. All rights reserved.
-
NASA Astrophysics Data System (ADS)
Jalilov, S.; Fukushi, K.
2016-12-01
Population growth, high rates of economic development and rapid urbanization in the developing countries of Southeast Asia (SEA) have resulted in degradation and depletion of natural resources, including water resources and related ecosystem services. Many urban rivers in the region are highly polluted with domestic, industrial and agricultural wastes. Policymakers are often aware of the direct value of water resources for domestic and industrial consumption, but they often underestimate the indirect value of these functions, since they are not exchanged in the market and do not appear in national income accounts. Underestimation of pollution and over-exploitation of water resources result in a loss of these benefits and have adverse impacts on nearby residents, threatening the long-term sustainable development of natural resources in the region. Behind these constraints lies a lack of knowledge (ignorance) from governments that a clean water environment could bring significant economic benefits. This study has been initiated to tackle this issue and to foster a more rational approach for sustainable urban development in Metro Manila in the Philippines. We applied a Contingent Valuation Method (CVM) based on Computer-Assisted Personal Interviewing (CAPI) technique. Results show that users are willing to pay up to PHP 102.42 (2.18) monthly to improve quality of urban waterbodies whereas nonusers are willing to pay up to PHP 366.53 (7.80) as one-time payment towards water quality improvement. The estimated monetary value of water quality improvements would be a useful variable in cost-benefit analyses of various water quality-related policies, in both public and private sectors in Metro Manila. This survey design could serve as a useful template for similar water quality studies in other SEA countries.
-
Wang, Keran; Wu, Jinyi; Wang, Rui; Yang, Yingying; Chen, Renjie; Maddock, Jay E; Lu, Yuanan
2015-11-15
Shanghai, along with many major cities in China, faces deterioration of air quality and increases in air pollution-related respiratory diseases (RDs) in children due to rapid industrialization and urbanization. The Contingent Valuation Method (CVM) was used to qualitatively and quantitatively measure the willingness to pay (WTP) for reducing children's RDs through air quality improvement. Between April and May, 2014, 975 face-to-face interviews were collected from parents in a community-based and a hospital-setting in Shanghai. Multiple imputation and the Probit model were used to determine the relationship between the WTP and the related environmental factors, child health factors and the socio-economic status. Most respondents reported being willing to make a financial contribution to improve air quality in both the community (52.6%) and hospital (70.2%) samples. Those in the hospital setting were willing to pay significantly more ¥504 (USD$80.7) compared to the community sample ¥428 ($68.5) as expected. Reasons for those not being willing to pay included lack of disposable income and believing that responsibility of the air quality was a community issue. These did not differ by sample. Annual household income and education were related to WTP. This study indicated that parents in Shanghai would be willing to pay for improved air quality. Children's health can be the incentive for the citizens' participation and support in the air quality improvement, therefore, hospital settings may present unique places to improve education about air quality and enhance advocacy efforts. This study also suggested that future environmental policies be addressed more rigorously for targeted populations. Copyright © 2015 Elsevier B.V. All rights reserved.
-
Comparison of variational real-space representations of the kinetic energy operator
NASA Astrophysics Data System (ADS)
Skylaris, Chris-Kriton; Diéguez, Oswaldo; Haynes, Peter D.; Payne, Mike C.
2002-08-01
We present a comparison of real-space methods based on regular grids for electronic structure calculations that are designed to have basis set variational properties, using as a reference the conventional method of finite differences (a real-space method that is not variational) and the reciprocal-space plane-wave method which is fully variational. We find that a definition of the finite-difference method [P. Maragakis, J. Soler, and E. Kaxiras, Phys. Rev. B 64, 193101 (2001)] satisfies one of the two properties of variational behavior at the cost of larger errors than the conventional finite-difference method. On the other hand, a technique which represents functions in a number of plane waves which is independent of system size closely follows the plane-wave method and therefore also the criteria for variational behavior. Its application is only limited by the requirement of having functions strictly localized in regions of real space, but this is a characteristic of an increasing number of modern real-space methods, as they are designed to have a computational cost that scales linearly with system size.
-
Variation block-based genomics method for crop plants.
Kim, Yul Ho; Park, Hyang Mi; Hwang, Tae-Young; Lee, Seuk Ki; Choi, Man Soo; Jho, Sungwoong; Hwang, Seungwoo; Kim, Hak-Min; Lee, Dongwoo; Kim, Byoung-Chul; Hong, Chang Pyo; Cho, Yun Sung; Kim, Hyunmin; Jeong, Kwang Ho; Seo, Min Jung; Yun, Hong Tai; Kim, Sun Lim; Kwon, Young-Up; Kim, Wook Han; Chun, Hye Kyung; Lim, Sang Jong; Shin, Young-Ah; Choi, Ik-Young; Kim, Young Sun; Yoon, Ho-Sung; Lee, Suk-Ha; Lee, Sunghoon
2014-06-15
In contrast with wild species, cultivated crop genomes consist of reshuffled recombination blocks, which occurred by crossing and selection processes. Accordingly, recombination block-based genomics analysis can be an effective approach for the screening of target loci for agricultural traits. We propose the variation block method, which is a three-step process for recombination block detection and comparison. The first step is to detect variations by comparing the short-read DNA sequences of the cultivar to the reference genome of the target crop. Next, sequence blocks with variation patterns are examined and defined. The boundaries between the variation-containing sequence blocks are regarded as recombination sites. All the assumed recombination sites in the cultivar set are used to split the genomes, and the resulting sequence regions are termed variation blocks. Finally, the genomes are compared using the variation blocks. The variation block method identified recurring recombination blocks accurately and successfully represented block-level diversities in the publicly available genomes of 31 soybean and 23 rice accessions. The practicality of this approach was demonstrated by the identification of a putative locus determining soybean hilum color. We suggest that the variation block method is an efficient genomics method for the recombination block-level comparison of crop genomes. We expect that this method will facilitate the development of crop genomics by bringing genomics technologies to the field of crop breeding.
-
Speckle reduction in optical coherence tomography by adaptive total variation method
NASA Astrophysics Data System (ADS)
Wu, Tong; Shi, Yaoyao; Liu, Youwen; He, Chongjun
2015-12-01
An adaptive total variation method based on the combination of speckle statistics and total variation restoration is proposed and developed for reducing speckle noise in optical coherence tomography (OCT) images. The statistical distribution of the speckle noise in OCT image is investigated and measured. With the measured parameters such as the mean value and variance of the speckle noise, the OCT image is restored by the adaptive total variation restoration method. The adaptive total variation restoration algorithm was applied to the OCT images of a volunteer's hand skin, which showed effective speckle noise reduction and image quality improvement. For image quality comparison, the commonly used median filtering method was also applied to the same images to reduce the speckle noise. The measured results demonstrate the superior performance of the adaptive total variation restoration method in terms of image signal-to-noise ratio, equivalent number of looks, contrast-to-noise ratio, and mean square error.
-
NASA Technical Reports Server (NTRS)
Ibrahim, A. H.; Tiwari, S. N.; Smith, R. E.
1997-01-01
Variational methods (VM) sensitivity analysis employed to derive the costate (adjoint) equations, the transversality conditions, and the functional sensitivity derivatives. In the derivation of the sensitivity equations, the variational methods use the generalized calculus of variations, in which the variable boundary is considered as the design function. The converged solution of the state equations together with the converged solution of the costate equations are integrated along the domain boundary to uniquely determine the functional sensitivity derivatives with respect to the design function. The application of the variational methods to aerodynamic shape optimization problems is demonstrated for internal flow problems at supersonic Mach number range. The study shows, that while maintaining the accuracy of the functional sensitivity derivatives within the reasonable range for engineering prediction purposes, the variational methods show a substantial gain in computational efficiency, i.e., computer time and memory, when compared with the finite difference sensitivity analysis.
-
NASA Astrophysics Data System (ADS)
Wang, Yi-Hong; Wu, Guo-Cheng; Baleanu, Dumitru
2013-10-01
The variational iteration method is newly used to construct various integral equations of fractional order. Some iterative schemes are proposed which fully use the method and the predictor-corrector approach. The fractional Bagley-Torvik equation is then illustrated as an example of multi-order and the results show the efficiency of the variational iteration method's new role.
-
Using the Screened Coulomb Potential to Illustrate the Variational Method
ERIC Educational Resources Information Center
Zuniga, Jose; Bastida, Adolfo; Requena, Alberto
2012-01-01
The screened Coulomb potential, or Yukawa potential, is used to illustrate the application of the single and linear variational methods. The trial variational functions are expressed in terms of Slater-type functions, for which the integrals needed to carry out the variational calculations are easily evaluated in closed form. The variational…
-
Variational estimate method for solving autonomous ordinary differential equations
NASA Astrophysics Data System (ADS)
Mungkasi, Sudi
2018-04-01
In this paper, we propose a method for solving first-order autonomous ordinary differential equation problems using a variational estimate formulation. The variational estimate is constructed with a Lagrange multiplier which is chosen optimally, so that the formulation leads to an accurate solution to the problem. The variational estimate is an integral form, which can be computed using a computer software. As the variational estimate is an explicit formula, the solution is easy to compute. This is a great advantage of the variational estimate formulation.
-
Wagner Mackenzie, Brett; Waite, David W; Taylor, Michael W
2015-01-01
The human gut contains dense and diverse microbial communities which have profound influences on human health. Gaining meaningful insights into these communities requires provision of high quality microbial nucleic acids from human fecal samples, as well as an understanding of the sources of variation and their impacts on the experimental model. We present here a systematic analysis of commonly used microbial DNA extraction methods, and identify significant sources of variation. Five extraction methods (Human Microbiome Project protocol, MoBio PowerSoil DNA Isolation Kit, QIAamp DNA Stool Mini Kit, ZR Fecal DNA MiniPrep, phenol:chloroform-based DNA isolation) were evaluated based on the following criteria: DNA yield, quality and integrity, and microbial community structure based on Illumina amplicon sequencing of the V4 region of bacterial and archaeal 16S rRNA genes. Our results indicate that the largest portion of variation within the model was attributed to differences between subjects (biological variation), with a smaller proportion of variation associated with DNA extraction method (technical variation) and intra-subject variation. A comprehensive understanding of the potential impact of technical variation on the human gut microbiota will help limit preventable bias, enabling more accurate diversity estimates.
-
The Effects of Predator Evolution and Genetic Variation on Predator-Prey Population-Level Dynamics.
Cortez, Michael H; Patel, Swati
2017-07-01
This paper explores how predator evolution and the magnitude of predator genetic variation alter the population-level dynamics of predator-prey systems. We do this by analyzing a general eco-evolutionary predator-prey model using four methods: Method 1 identifies how eco-evolutionary feedbacks alter system stability in the fast and slow evolution limits; Method 2 identifies how the amount of standing predator genetic variation alters system stability; Method 3 identifies how the phase lags in predator-prey cycles depend on the amount of genetic variation; and Method 4 determines conditions for different cycle shapes in the fast and slow evolution limits using geometric singular perturbation theory. With these four methods, we identify the conditions under which predator evolution alters system stability and shapes of predator-prey cycles, and how those effect depend on the amount of genetic variation in the predator population. We discuss the advantages and disadvantages of each method and the relations between the four methods. This work shows how the four methods can be used in tandem to make general predictions about eco-evolutionary dynamics and feedbacks.
-
NASA Astrophysics Data System (ADS)
Wang, Min
2017-06-01
This paper aims to establish the Tikhonov regularization method for generalized mixed variational inequalities in Banach spaces. For this purpose, we firstly prove a very general existence result for generalized mixed variational inequalities, provided that the mapping involved has the so-called mixed variational inequality property and satisfies a rather weak coercivity condition. Finally, we establish the Tikhonov regularization method for generalized mixed variational inequalities. Our findings extended the results for the generalized variational inequality problem (for short, GVIP( F, K)) in R^n spaces (He in Abstr Appl Anal, 2012) to the generalized mixed variational inequality problem (for short, GMVIP(F,φ , K)) in reflexive Banach spaces. On the other hand, we generalized the corresponding results for the generalized mixed variational inequality problem (for short, GMVIP(F,φ ,K)) in R^n spaces (Fu and He in J Sichuan Norm Univ (Nat Sci) 37:12-17, 2014) to reflexive Banach spaces.
-
Introduction to the Special Issue on Advancing Methods for Analyzing Dialect Variation.
Clopper, Cynthia G
2017-07-01
Documenting and analyzing dialect variation is traditionally the domain of dialectology and sociolinguistics. However, modern approaches to acoustic analysis of dialect variation have their roots in Peterson and Barney's [(1952). J. Acoust. Soc. Am. 24, 175-184] foundational work on the acoustic analysis of vowels that was published in the Journal of the Acoustical Society of America (JASA) over 6 decades ago. Although Peterson and Barney (1952) were not primarily concerned with dialect variation, their methods laid the groundwork for the acoustic methods that are still used by scholars today to analyze vowel variation within and across languages. In more recent decades, a number of methodological advances in the study of vowel variation have been published in JASA, including work on acoustic vowel overlap and vowel normalization. The goal of this special issue was to honor that tradition by bringing together a set of papers describing the application of emerging acoustic, articulatory, and computational methods to the analysis of dialect variation in vowels and beyond.
-
NASA Astrophysics Data System (ADS)
Li, Shuo; Wang, Hui; Wang, Liyong; Yu, Xiangzhou; Yang, Le
2018-01-01
The uneven illumination phenomenon reduces the quality of remote sensing image and causes interference in the subsequent processing and applications. A variational method based on Retinex with double-norm hybrid constraints for uneven illumination correction is proposed. The L1 norm and the L2 norm are adopted to constrain the textures and details of reflectance image and the smoothness of the illumination image, respectively. The problem of separating the illumination image from the reflectance image is transformed into the optimal solution of the variational model. In order to accelerate the solution, the split Bregman method is used to decompose the variational model into three subproblems, which are calculated by alternate iteration. Two groups of experiments are implemented on two synthetic images and three real remote sensing images. Compared with the variational Retinex method with single-norm constraint and the Mask method, the proposed method performs better in both visual evaluation and quantitative measurements. The proposed method can effectively eliminate the uneven illumination while maintaining the textures and details of the remote sensing image. Moreover, the proposed method using split Bregman method is more than 10 times faster than the method with the steepest descent method.
-
Drake, Adryanna A S; Hafen, McArthur; Rush, Bonnie R
Much has been discussed about the high prevalence of psychological distress among veterinary medical students. Studies investigating general samples of veterinary medical students indicate that, on average, depression and anxiety symptoms are present at higher rates than in comparison samples. However, little is known about veterinary medical students who seek counseling. This study intends to expand the literature on veterinary student well-being, as the first to examine a sample of veterinary medical students seeking counseling services. It offers an overview of student distress and help-seeking trends from a decade of counseling services provided in one College of Veterinary Medicine (CVM) in the US. The sample includes data from 279 participants. Results indicate a steady increase in students seeking counseling over the last decade. First-year students sought services at higher rates but second-year students experienced the greatest distress when compared to other cohorts. Students seeking counseling services experienced levels of overall distress, symptoms of anxiety and depression, and social role concerns that were, on average, above cut-off scores. Physical health was significantly associated with student distress, suggesting opportunities for intervention.
-
NASA Astrophysics Data System (ADS)
Minakuchi, Shu; Tsukamoto, Haruka; Takeda, Nobuo
2009-03-01
This study proposes novel hierarchical sensing concept for detecting damages in composite structures. In the hierarchical system, numerous three-dimensionally structured sensor devices are distributed throughout the whole structural area and connected with the optical fiber network through transducing mechanisms. The distributed "sensory nerve cell" devices detect the damage, and the fiber optic "spinal cord" network gathers damage signals and transmits the information to a measuring instrument. This study began by discussing the basic concept of the hierarchical sensing system thorough comparison with existing fiber optic based systems and nerve systems in the animal kingdom. Then, in order to validate the proposed sensing concept, impact damage detection system for the composite structure was proposed. The sensor devices were developed based on Comparative Vacuum Monitoring (CVM) system and the Brillouin based distributed strain sensing was utilized to gather the damage signals from the distributed devices. Finally a verification test was conducted using prototype devices. Occurrence of barely visible impact damage was successfully detected and it was clearly indicated that the hierarchical system has better repairability, higher robustness, and wider monitorable area compared to existing systems utilizing embedded optical fiber sensors.
-
Experimental studies of breaking of elastic tired wheel under variable normal load
NASA Astrophysics Data System (ADS)
Fedotov, A. I.; Zedgenizov, V. G.; Ovchinnikova, N. I.
2017-10-01
The paper analyzes the braking of a vehicle wheel subjected to disturbances of normal load variations. Experimental tests and methods for developing test modes as sinusoidal force disturbances of the normal wheel load were used. Measuring methods for digital and analogue signals were used as well. Stabilization of vehicle wheel braking subjected to disturbances of normal load variations is a topical issue. The paper suggests a method for analyzing wheel braking processes under disturbances of normal load variations. A method to control wheel baking processes subjected to disturbances of normal load variations was developed.
-
Scaling up functional traits for ecosystem services with remote sensing: concepts and methods.
Abelleira Martínez, Oscar J; Fremier, Alexander K; Günter, Sven; Ramos Bendaña, Zayra; Vierling, Lee; Galbraith, Sara M; Bosque-Pérez, Nilsa A; Ordoñez, Jenny C
2016-07-01
Ecosystem service-based management requires an accurate understanding of how human modification influences ecosystem processes and these relationships are most accurate when based on functional traits. Although trait variation is typically sampled at local scales, remote sensing methods can facilitate scaling up trait variation to regional scales needed for ecosystem service management. We review concepts and methods for scaling up plant and animal functional traits from local to regional spatial scales with the goal of assessing impacts of human modification on ecosystem processes and services. We focus our objectives on considerations and approaches for (1) conducting local plot-level sampling of trait variation and (2) scaling up trait variation to regional spatial scales using remotely sensed data. We show that sampling methods for scaling up traits need to account for the modification of trait variation due to land cover change and species introductions. Sampling intraspecific variation, stratification by land cover type or landscape context, or inference of traits from published sources may be necessary depending on the traits of interest. Passive and active remote sensing are useful for mapping plant phenological, chemical, and structural traits. Combining these methods can significantly improve their capacity for mapping plant trait variation. These methods can also be used to map landscape and vegetation structure in order to infer animal trait variation. Due to high context dependency, relationships between trait variation and remotely sensed data are not directly transferable across regions. We end our review with a brief synthesis of issues to consider and outlook for the development of these approaches. Research that relates typical functional trait metrics, such as the community-weighted mean, with remote sensing data and that relates variation in traits that cannot be remotely sensed to other proxies is needed. Our review narrows the gap between functional trait and remote sensing methods for ecosystem service management.
-
Variational method for integrating radial gradient field
NASA Astrophysics Data System (ADS)
Legarda-Saenz, Ricardo; Brito-Loeza, Carlos; Rivera, Mariano; Espinosa-Romero, Arturo
2014-12-01
We propose a variational method for integrating information obtained from circular fringe pattern. The proposed method is a suitable choice for objects with radial symmetry. First, we analyze the information contained in the fringe pattern captured by the experimental setup and then move to formulate the problem of recovering the wavefront using techniques from calculus of variations. The performance of the method is demonstrated by numerical experiments with both synthetic and real data.
-
NASA Astrophysics Data System (ADS)
Kowalski, Dariusz
2017-06-01
The paper deals with the method to identify internal stresses in two-dimensional steel members. Steel members were investigated in the delivery stage and after assembly, by means of electric-arc welding. In order to perform the member assessment two methods to identify the stress variation were applied. The first is a non-destructive measurement method employing local external magnetic field and to detecting the induced voltage, including Barkhausen noise The analysis of the latter allows to assess internal stresses in a surface layer of the material. The second method, essential in the paper, is a semi-trepanation Mathar method of tensometric strain variation measurement in the course of a controlled void-making in the material. Variation of internal stress distribution in the material led to the choice of welding technology to join. The assembly process altered the actual stresses and made up new stresses, triggering post-welding stresses as a response for the excessive stress variation.
-
Estimation and Partitioning of Heritability in Human Populations using Whole Genome Analysis Methods
Vinkhuyzen, Anna AE; Wray, Naomi R; Yang, Jian; Goddard, Michael E; Visscher, Peter M
2014-01-01
Understanding genetic variation of complex traits in human populations has moved from the quantification of the resemblance between close relatives to the dissection of genetic variation into the contributions of individual genomic loci. But major questions remain unanswered: how much phenotypic variation is genetic, how much of the genetic variation is additive and what is the joint distribution of effect size and allele frequency at causal variants? We review and compare three whole-genome analysis methods that use mixed linear models (MLM) to estimate genetic variation, using the relationship between close or distant relatives based on pedigree or SNPs. We discuss theory, estimation procedures, bias and precision of each method and review recent advances in the dissection of additive genetic variation of complex traits in human populations that are based upon the application of MLM. Using genome wide data, SNPs account for far more of the genetic variation than the highly significant SNPs associated with a trait, but they do not account for all of the genetic variance estimated by pedigree based methods. We explain possible reasons for this ‘missing’ heritability. PMID:23988118
-
Second-order variational equations for N-body simulations
NASA Astrophysics Data System (ADS)
Rein, Hanno; Tamayo, Daniel
2016-07-01
First-order variational equations are widely used in N-body simulations to study how nearby trajectories diverge from one another. These allow for efficient and reliable determinations of chaos indicators such as the Maximal Lyapunov characteristic Exponent (MLE) and the Mean Exponential Growth factor of Nearby Orbits (MEGNO). In this paper we lay out the theoretical framework to extend the idea of variational equations to higher order. We explicitly derive the differential equations that govern the evolution of second-order variations in the N-body problem. Going to second order opens the door to new applications, including optimization algorithms that require the first and second derivatives of the solution, like the classical Newton's method. Typically, these methods have faster convergence rates than derivative-free methods. Derivatives are also required for Riemann manifold Langevin and Hamiltonian Monte Carlo methods which provide significantly shorter correlation times than standard methods. Such improved optimization methods can be applied to anything from radial-velocity/transit-timing-variation fitting to spacecraft trajectory optimization to asteroid deflection. We provide an implementation of first- and second-order variational equations for the publicly available REBOUND integrator package. Our implementation allows the simultaneous integration of any number of first- and second-order variational equations with the high-accuracy IAS15 integrator. We also provide routines to generate consistent and accurate initial conditions without the need for finite differencing.
-
2018-04-01
systems containing ionized gases. 2. Gibbs Method in the Integral Form As per the Gibbs general methodology , based on the concept of heterogeneous...ARL-TR-8348 ● APR 2018 US Army Research Laboratory The Gibbs Variational Method in Thermodynamics of Equilibrium Plasma: 1...ARL-TR-8348 ● APR 2018 US Army Research Laboratory The Gibbs Variational Method in Thermodynamics of Equilibrium Plasma: 1. General
-
The Schwinger Variational Method
NASA Technical Reports Server (NTRS)
Huo, Winifred M.
1995-01-01
Variational methods have proven invaluable in theoretical physics and chemistry, both for bound state problems and for the study of collision phenomena. For collisional problems they can be grouped into two types: those based on the Schroedinger equation and those based on the Lippmann-Schwinger equation. The application of the Schwinger variational (SV) method to e-molecule collisions and photoionization has been reviewed previously. The present chapter discusses the implementation of the SV method as applied to e-molecule collisions.
-
ERIC Educational Resources Information Center
Quinn, Terry; Rai, Sanjay
2012-01-01
The method of variation of parameters can be found in most undergraduate textbooks on differential equations. The method leads to solutions of the non-homogeneous equation of the form y = u[subscript 1]y[subscript 1] + u[subscript 2]y[subscript 2], a sum of function products using solutions to the homogeneous equation y[subscript 1] and…
-
Total generalized variation-regularized variational model for single image dehazing
NASA Astrophysics Data System (ADS)
Shu, Qiao-Ling; Wu, Chuan-Sheng; Zhong, Qiu-Xiang; Liu, Ryan Wen
2018-04-01
Imaging quality is often significantly degraded under hazy weather condition. The purpose of this paper is to recover the latent sharp image from its hazy version. It is well known that the accurate estimation of depth information could assist in improving dehazing performance. In this paper, a detail-preserving variational model was proposed to simultaneously estimate haze-free image and depth map. In particular, the total variation (TV) and total generalized variation (TGV) regularizers were introduced to restrain haze-free image and depth map, respectively. The resulting nonsmooth optimization problem was efficiently solved using the alternating direction method of multipliers (ADMM). Comprehensive experiments have been conducted on realistic datasets to compare our proposed method with several state-of-the-art dehazing methods. Results have illustrated the superior performance of the proposed method in terms of visual quality evaluation.
-
Willingness and ability to pay for artemisinin-based combination therapy in rural Tanzania
Saulo, Eleonor C; Forsberg, Birger C; Premji, Zul; Montgomery, Scott M; Björkman, Anders
2008-01-01
Background The aim of this study was to analyse willingness to pay (WTP) and ability to pay (ATP) for ACT for children below five years of age in a rural setting in Tanzania before the introduction of artemisinin-based combination therapy (ACT) as first-line treatment for uncomplicated malaria. Socio-economic factors associated with WTP and expectations on anti-malaria drugs, including ACT, were also explored. Methods Structured interviews and focus group discussions were held with mothers, household heads, health-care workers and village leaders in Ishozi, Gera and Ishunju wards in north-west Tanzania in 2004. Contingent valuation method (CVM) was used with "take-it-or-leave-it" as the eliciting method, expressed as WTP for a full course of ACT for a child and households' opportunity cost of ACT was used to assess ATP. The study included descriptive analyses with multivariate adjustment for potential confounding factors. Results Among 265 mothers and household heads, 244 (92%, CI = 88%–95%) were willing to pay Tanzanian Shillings (TSh) 500 (US$ 0.46) for a child's dose of ACT, but only 55% (49%–61%) were willing to pay more than TSh 500. Mothers were more often willing to pay than male household heads (adjusted odds ratio = 2.1, CI = 1.2–3.6). Socio-economic status had no significant effect on WTP. The median annual non-subsidized ACT cost for clinical malaria episodes in an average household was calculated as US$ 6.0, which would represent 0.9% of the average total consumption expenditures as estimated from official data in 2001. The cost of non-subsidized ACT represented 7.0% of reported total annual expenditure on food and 33.0% of total annual expenditure on health care. "Rapid effect," "no adverse effect" and "inexpensive" were the most desired features of an anti-malarial drug. Conclusion WTP for ACT in this study was less than its real cost and a subsidy is, therefore, needed to enable its equitable affordability. The decision taken in Tanzania to subsidize Coartem® fully at governmental health care facilities and at a consumer price of TSh 300–500 (US$ 0.28–0.46) at special designated shops through the programme of Accredited Drug Dispensing Outlets (ADDOs) appears to be well founded. PMID:18976453
-
Variational formulation of high performance finite elements: Parametrized variational principles
NASA Technical Reports Server (NTRS)
Felippa, Carlos A.; Militello, Carmello
1991-01-01
High performance elements are simple finite elements constructed to deliver engineering accuracy with coarse arbitrary grids. This is part of a series on the variational basis of high-performance elements, with emphasis on those constructed with the free formulation (FF) and assumed natural strain (ANS) methods. Parametrized variational principles that provide a foundation for the FF and ANS methods, as well as for a combination of both are presented.
-
Song, Junqiang; Leng, Hongze; Lu, Fengshun
2014-01-01
We present a new numerical method to get the approximate solutions of fractional differential equations. A new operational matrix of integration for fractional-order Legendre functions (FLFs) is first derived. Then a modified variational iteration formula which can avoid “noise terms” is constructed. Finally a numerical method based on variational iteration method (VIM) and FLFs is developed for fractional differential equations (FDEs). Block-pulse functions (BPFs) are used to calculate the FLFs coefficient matrices of the nonlinear terms. Five examples are discussed to demonstrate the validity and applicability of the technique. PMID:24511303
-
Iterative Nonlocal Total Variation Regularization Method for Image Restoration
Xu, Huanyu; Sun, Quansen; Luo, Nan; Cao, Guo; Xia, Deshen
2013-01-01
In this paper, a Bregman iteration based total variation image restoration algorithm is proposed. Based on the Bregman iteration, the algorithm splits the original total variation problem into sub-problems that are easy to solve. Moreover, non-local regularization is introduced into the proposed algorithm, and a method to choose the non-local filter parameter locally and adaptively is proposed. Experiment results show that the proposed algorithms outperform some other regularization methods. PMID:23776560
-
Accurate sparse-projection image reconstruction via nonlocal TV regularization.
Zhang, Yi; Zhang, Weihua; Zhou, Jiliu
2014-01-01
Sparse-projection image reconstruction is a useful approach to lower the radiation dose; however, the incompleteness of projection data will cause degeneration of imaging quality. As a typical compressive sensing method, total variation has obtained great attention on this problem. Suffering from the theoretical imperfection, total variation will produce blocky effect on smooth regions and blur edges. To overcome this problem, in this paper, we introduce the nonlocal total variation into sparse-projection image reconstruction and formulate the minimization problem with new nonlocal total variation norm. The qualitative and quantitative analyses of numerical as well as clinical results demonstrate the validity of the proposed method. Comparing to other existing methods, our method more efficiently suppresses artifacts caused by low-rank reconstruction and reserves structure information better.
-
Application of Variational Methods to the Thermal Entrance Region of Ducts
NASA Technical Reports Server (NTRS)
Sparrow, E. M.; Siegel. R.
1960-01-01
A variational method is presented for solving eigenvalue problems which arise in connection with the analysis of convective heat transfer in the thermal entrance region of ducts. Consideration is given, to both situations where the temperature profile depends upon one cross-sectional coordinate (e.g. circular tube) or upon two cross-sectional coordinates (e.g. rectangular duct). The variational method is illustrated and verified by application to laminar heat transfer in a circular tube and a parallel-plate channel, and good agreement with existing numerical solutions is attained. Then, application is made to laminar heat transfer in a square duct as a check, an alternate computation for the square duct is made using a method indicated by Misaps and Pohihausen. The variational method can, in principle, also be applied to problems in turbulent heat transfer.
-
Study of weak solutions for parabolic variational inequalities with nonstandard growth conditions.
Dong, Yan
2018-01-01
In this paper, we study the degenerate parabolic variational inequality problem in a bounded domain. First, the weak solutions of the variational inequality are defined. Second, the existence and uniqueness of the solutions in the weak sense are proved by using the penalty method and the reduction method.
-
NASA Technical Reports Server (NTRS)
Roth, Don J.; Farmer, Donald A.
1998-01-01
Abrasive cut-off wheels are at times unintentionally manufactured with nonuniformity that is difficult to identify and sufficiently characterize without time-consuming, destructive examination. One particular nonuniformity is a density variation condition occurring around the wheel circumference or along the radius, or both. This density variation, depending on its severity, can cause wheel warpage and wheel vibration resulting in unacceptable performance and perhaps premature failure of the wheel. Conventional nondestructive evaluation methods such as ultrasonic c-scan imaging and film radiography are inaccurate in their attempts at characterizing the density variation because a superimposing thickness variation exists as well in the wheel. In this article, the single transducer thickness-independent ultrasonic imaging method, developed specifically to allow more accurate characterization of aerospace components, is shown to precisely characterize the extent of the density variation in a cut-off wheel having a superimposing thickness variation. The method thereby has potential as an effective quality control tool in the abrasives industry for the wheel manufacturer.
-
A novel iterative scheme and its application to differential equations.
Khan, Yasir; Naeem, F; Šmarda, Zdeněk
2014-01-01
The purpose of this paper is to employ an alternative approach to reconstruct the standard variational iteration algorithm II proposed by He, including Lagrange multiplier, and to give a simpler formulation of Adomian decomposition and modified Adomian decomposition method in terms of newly proposed variational iteration method-II (VIM). Through careful investigation of the earlier variational iteration algorithm and Adomian decomposition method, we find unnecessary calculations for Lagrange multiplier and also repeated calculations involved in each iteration, respectively. Several examples are given to verify the reliability and efficiency of the method.
-
A Comparison of Cut Scores Using Multiple Standard Setting Methods.
ERIC Educational Resources Information Center
Impara, James C.; Plake, Barbara S.
This paper reports the results of using several alternative methods of setting cut scores. The methods used were: (1) a variation of the Angoff method (1971); (2) a variation of the borderline group method; and (3) an advanced impact method (G. Dillon, 1996). The results discussed are from studies undertaken to set the cut scores for fourth grade…
-
Solution of the Time-Dependent Schrödinger Equation by the Laplace Transform Method
Lin, S. H.; Eyring, H.
1971-01-01
The time-dependent Schrödinger equation for two quite general types of perturbation has been solved by introducing the Laplace transforms to eliminate the time variable. The resulting time-independent differential equation can then be solved by the perturbation method, the variation method, the variation-perturbation method, and other methods. PMID:16591898
-
Juárez, M; Polvillo, O; Contò, M; Ficco, A; Ballico, S; Failla, S
2008-05-09
Four different extraction-derivatization methods commonly used for fatty acid analysis in meat (in situ or one-step method, saponification method, classic method and a combination of classic extraction and saponification derivatization) were tested. The in situ method had low recovery and variation. The saponification method showed the best balance between recovery, precision, repeatability and reproducibility. The classic method had high recovery and acceptable variation values, except for the polyunsaturated fatty acids, showing higher variation than the former methods. The combination of extraction and methylation steps had great recovery values, but the precision, repeatability and reproducibility were not acceptable. Therefore the saponification method would be more convenient for polyunsaturated fatty acid analysis, whereas the in situ method would be an alternative for fast analysis. However the classic method would be the method of choice for the determination of the different lipid classes.
-
NASA Astrophysics Data System (ADS)
Huang, Z.; Chen, Q.; Shen, Y.; Chen, Q.; Liu, X.
2017-09-01
Variational pansharpening can enhance the spatial resolution of a hyperspectral (HS) image using a high-resolution panchromatic (PAN) image. However, this technology may lead to spectral distortion that obviously affect the accuracy of data analysis. In this article, we propose an improved variational method for HS image pansharpening with the constraint of spectral difference minimization. We extend the energy function of the classic variational pansharpening method by adding a new spectral fidelity term. This fidelity term is designed following the definition of spectral angle mapper, which means that for every pixel, the spectral difference value of any two bands in the HS image is in equal proportion to that of the two corresponding bands in the pansharpened image. Gradient descent method is adopted to find the optimal solution of the modified energy function, and the pansharpened image can be reconstructed. Experimental results demonstrate that the constraint of spectral difference minimization is able to preserve the original spectral information well in HS images, and reduce the spectral distortion effectively. Compared to original variational method, our method performs better in both visual and quantitative evaluation, and achieves a good trade-off between spatial and spectral information.
-
Takahashi, M; Tango, T
2001-05-01
As methods for estimating excess mortality associated with influenza-epidemic, the Serfling's cyclical regression model and the Kawai and Fukutomi model with seasonal indices have been proposed. Excess mortality under the old definition (i.e., the number of deaths actually recorded in excess of the number expected on the basis of past seasonal experience) covers the random error for that portion of variation regarded as due to chance. In addition, it disregards the range of random variation of mortality with the season. In this paper, we propose a new definition of excess mortality associated with influenza-epidemics and a new estimation method, considering these questions with the Kawai and Fukutomi method. The new definition of excess mortality and a novel method for its estimation were generated as follows. Factors bringing about variation in mortality in months with influenza-epidemics may be divided into two groups: 1. Influenza itself, 2. others (practically random variation). The range of variation of mortality due to the latter (normal range) can be estimated from the range for months in the absence of influenza-epidemics. Excess mortality is defined as death over the normal range. A new definition of excess mortality associated with influenza-epidemics and an estimation method are proposed. The new method considers variation in mortality in months in the absence of influenza-epidemics. Consequently, it provides reasonable estimates of excess mortality by separating the portion of random variation. Further, it is a characteristic that the proposed estimate can be used as a criterion of statistical significance test.
-
NASA Astrophysics Data System (ADS)
Norros, Veera; Laine, Marko; Lignell, Risto; Thingstad, Frede
2017-10-01
Methods for extracting empirically and theoretically sound parameter values are urgently needed in aquatic ecosystem modelling to describe key flows and their variation in the system. Here, we compare three Bayesian formulations for mechanistic model parameterization that differ in their assumptions about the variation in parameter values between various datasets: 1) global analysis - no variation, 2) separate analysis - independent variation and 3) hierarchical analysis - variation arising from a shared distribution defined by hyperparameters. We tested these methods, using computer-generated and empirical data, coupled with simplified and reasonably realistic plankton food web models, respectively. While all methods were adequate, the simulated example demonstrated that a well-designed hierarchical analysis can result in the most accurate and precise parameter estimates and predictions, due to its ability to combine information across datasets. However, our results also highlighted sensitivity to hyperparameter prior distributions as an important caveat of hierarchical analysis. In the more complex empirical example, hierarchical analysis was able to combine precise identification of parameter values with reasonably good predictive performance, although the ranking of the methods was less straightforward. We conclude that hierarchical Bayesian analysis is a promising tool for identifying key ecosystem-functioning parameters and their variation from empirical datasets.
-
Identification of Vibrotactile Patterns Encoding Obstacle Distance Information.
Kim, Yeongmi; Harders, Matthias; Gassert, Roger
2015-01-01
Delivering distance information of nearby obstacles from sensors embedded in a white cane-in addition to the intrinsic mechanical feedback from the cane-can aid the visually impaired in ambulating independently. Haptics is a common modality for conveying such information to cane users, typically in the form of vibrotactile signals. In this context, we investigated the effect of tactile rendering methods, tactile feedback configurations and directions of tactile flow on the identification of obstacle distance. Three tactile rendering methods with temporal variation only, spatio-temporal variation and spatial/temporal/intensity variation were investigated for two vibration feedback configurations. Results showed a significant interaction between tactile rendering method and feedback configuration. Spatio-temporal variation generally resulted in high correct identification rates for both feedback configurations. In the case of the four-finger vibration, tactile rendering with spatial/temporal/intensity variation also resulted in high distance identification rate. Further, participants expressed their preference for the four-finger vibration over the single-finger vibration in a survey. Both preferred rendering methods with spatio-temporal variation and spatial/temporal/intensity variation for the four-finger vibration could convey obstacle distance information with low workload. Overall, the presented findings provide valuable insights and guidance for the design of haptic displays for electronic travel aids for the visually impaired.
-
Survey Shows Variation in Ph.D. Methods Training.
ERIC Educational Resources Information Center
Steeves, Leslie; And Others
1983-01-01
Reports on a 1982 survey of journalism graduate studies indicating considerable variation in research methods requirements and emphases in 23 universities offering doctoral degrees in mass communication. (HOD)
-
Plate equations for piezoelectrically actuated flexural mode ultrasound transducers.
Perçin, Gökhan
2003-01-01
This paper considers variational methods to derive two-dimensional plate equations for piezoelectrically actuated flexural mode ultrasound transducers. In the absence of analytical expressions for the equivalent circuit parameters of a flexural mode transducer, it is difficult to calculate its optimal parameters and dimensions, and to choose suitable materials. The influence of coupling between flexural and extensional deformation, and coupling between the structure and the acoustic volume on the dynamic response of piezoelectrically actuated flexural mode transducer is analyzed using variational methods. Variational methods are applied to derive two-dimensional plate equations for the transducer, and to calculate the coupled electromechanical field variables. In these methods, the variations across the thickness direction vanish by using the stress resultants. Thus, two-dimensional plate equations for a stepwise laminated circular plate are obtained.
-
NASA Astrophysics Data System (ADS)
Maksimyuk, V. A.; Storozhuk, E. A.; Chernyshenko, I. S.
2012-11-01
Variational finite-difference methods of solving linear and nonlinear problems for thin and nonthin shells (plates) made of homogeneous isotropic (metallic) and orthotropic (composite) materials are analyzed and their classification principles and structure are discussed. Scalar and vector variational finite-difference methods that implement the Kirchhoff-Love hypotheses analytically or algorithmically using Lagrange multipliers are outlined. The Timoshenko hypotheses are implemented in a traditional way, i.e., analytically. The stress-strain state of metallic and composite shells of complex geometry is analyzed numerically. The numerical results are presented in the form of graphs and tables and used to assess the efficiency of using the variational finite-difference methods to solve linear and nonlinear problems of the statics of shells (plates)
-
NASA Astrophysics Data System (ADS)
Damay, Nicolas; Forgez, Christophe; Bichat, Marie-Pierre; Friedrich, Guy
2016-11-01
The entropy-variation of a battery is responsible for heat generation or consumption during operation and its prior measurement is mandatory for developing a thermal model. It is generally done through the potentiometric method which is considered as a reference. However, it requires several days or weeks to get a look-up table with a 5 or 10% SoC (State of Charge) resolution. In this study, a calorimetric method based on the inversion of a thermal model is proposed for the fast estimation of a nearly continuous curve of entropy-variation. This is achieved by separating the heats produced while charging and discharging the battery. The entropy-variation is then deduced from the extracted entropic heat. The proposed method is validated by comparing the results obtained with several current rates to measurements made with the potentiometric method.
-
Quantification of the Barkhausen noise method for the evaluation of time-dependent degradation
NASA Astrophysics Data System (ADS)
Kim, Dong-Won; Kwon, Dongil
2003-02-01
The Barkhausen noise (BN) method has long been applied to measure the bulk magnetic properties of magnetic materials. Recently, this important nondestructive testing (NDT) method has been applied to evaluate microstructure, stress distribution analysis, fatigue, creep and fracture characteristics. Until now the BN method has been used only qualitatively in evaluating the variation of BN with variations in material properties. For this reason, few NDT methods have been applied in industrial plants and laboratories. The present investigation studied the coercive force and BN while varying the microstructure of ultrafine-grained steels and SA508 cl.3 steels. This variation was carried out according to the second heat-treatment condition with rolling of ultrafine-grained steels and the simulated time-dependent degradation of SA 508 cl.3 steels. An attempt was also made to quantify BN from the relationship between the velocity of magnetic domain walls and the retarding force, using the coercive force of the domain wall movement. The microstructure variation was analyzed according to time-dependent degradation. Fracture toughness was evaluated quantitatively by measuring the BN from two intermediary parameters; grain size and distribution of nonmagnetic particles. From these measurements, the variation of microstructure and fracture toughness can be directly evaluated by the BN method as an accurate in situ NDT method.
-
Augmented classical least squares multivariate spectral analysis
Haaland, David M.; Melgaard, David K.
2004-02-03
A method of multivariate spectral analysis, termed augmented classical least squares (ACLS), provides an improved CLS calibration model when unmodeled sources of spectral variation are contained in a calibration sample set. The ACLS methods use information derived from component or spectral residuals during the CLS calibration to provide an improved calibration-augmented CLS model. The ACLS methods are based on CLS so that they retain the qualitative benefits of CLS, yet they have the flexibility of PLS and other hybrid techniques in that they can define a prediction model even with unmodeled sources of spectral variation that are not explicitly included in the calibration model. The unmodeled sources of spectral variation may be unknown constituents, constituents with unknown concentrations, nonlinear responses, non-uniform and correlated errors, or other sources of spectral variation that are present in the calibration sample spectra. Also, since the various ACLS methods are based on CLS, they can incorporate the new prediction-augmented CLS (PACLS) method of updating the prediction model for new sources of spectral variation contained in the prediction sample set without having to return to the calibration process. The ACLS methods can also be applied to alternating least squares models. The ACLS methods can be applied to all types of multivariate data.
-
Augmented Classical Least Squares Multivariate Spectral Analysis
Haaland, David M.; Melgaard, David K.
2005-07-26
A method of multivariate spectral analysis, termed augmented classical least squares (ACLS), provides an improved CLS calibration model when unmodeled sources of spectral variation are contained in a calibration sample set. The ACLS methods use information derived from component or spectral residuals during the CLS calibration to provide an improved calibration-augmented CLS model. The ACLS methods are based on CLS so that they retain the qualitative benefits of CLS, yet they have the flexibility of PLS and other hybrid techniques in that they can define a prediction model even with unmodeled sources of spectral variation that are not explicitly included in the calibration model. The unmodeled sources of spectral variation may be unknown constituents, constituents with unknown concentrations, nonlinear responses, non-uniform and correlated errors, or other sources of spectral variation that are present in the calibration sample spectra. Also, since the various ACLS methods are based on CLS, they can incorporate the new prediction-augmented CLS (PACLS) method of updating the prediction model for new sources of spectral variation contained in the prediction sample set without having to return to the calibration process. The ACLS methods can also be applied to alternating least squares models. The ACLS methods can be applied to all types of multivariate data.
-
Augmented Classical Least Squares Multivariate Spectral Analysis
Haaland, David M.; Melgaard, David K.
2005-01-11
A method of multivariate spectral analysis, termed augmented classical least squares (ACLS), provides an improved CLS calibration model when unmodeled sources of spectral variation are contained in a calibration sample set. The ACLS methods use information derived from component or spectral residuals during the CLS calibration to provide an improved calibration-augmented CLS model. The ACLS methods are based on CLS so that they retain the qualitative benefits of CLS, yet they have the flexibility of PLS and other hybrid techniques in that they can define a prediction model even with unmodeled sources of spectral variation that are not explicitly included in the calibration model. The unmodeled sources of spectral variation may be unknown constituents, constituents with unknown concentrations, nonlinear responses, non-uniform and correlated errors, or other sources of spectral variation that are present in the calibration sample spectra. Also, since the various ACLS methods are based on CLS, they can incorporate the new prediction-augmented CLS (PACLS) method of updating the prediction model for new sources of spectral variation contained in the prediction sample set without having to return to the calibration process. The ACLS methods can also be applied to alternating least squares models. The ACLS methods can be applied to all types of multivariate data.
-
NASA Astrophysics Data System (ADS)
Qiu, Tianlong; Zhang, Libin; Zhang, Tao; Bai, Yucen; Yang, Hongsheng
2014-07-01
There is substantial individual variation in the growth rates of sea cucumber Apostichopus japonicus individuals. This necessitates additional work to grade the seed stock and lengthens the production period. We evaluated the influence of three culture methods (free-mixed, isolated-mixed, isolated-alone) on individual variation in growth and assessed the relationship between feeding, energy conversion efficiency, and individual growth variation in individually cultured sea cucumbers. Of the different culture methods, animals grew best when reared in the isolated-mixed treatment (i.e., size classes were held separately), though there was no difference in individual variation in growth between rearing treatment groups. The individual variation in growth was primarily attributed to genetic factors. The difference in food conversion efficiency caused by genetic differences among individuals was thought to be the origin of the variance. The level of individual growth variation may be altered by interactions among individuals and environmental heterogeneity. Our results suggest that, in addition to traditional seed grading, design of a new kind of substrate that changes the spatial distribution of sea cucumbers would effectively enhance growth and reduce individual variation in growth of sea cucumbers in culture.
-
Statistics, Uncertainty, and Transmitted Variation
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wendelberger, Joanne Roth
2014-11-05
The field of Statistics provides methods for modeling and understanding data and making decisions in the presence of uncertainty. When examining response functions, variation present in the input variables will be transmitted via the response function to the output variables. This phenomenon can potentially have significant impacts on the uncertainty associated with results from subsequent analysis. This presentation will examine the concept of transmitted variation, its impact on designed experiments, and a method for identifying and estimating sources of transmitted variation in certain settings.
-
Reconstruction of fluorophore concentration variation in dynamic fluorescence molecular tomography.
Zhang, Xuanxuan; Liu, Fei; Zuo, Simin; Shi, Junwei; Zhang, Guanglei; Bai, Jing; Luo, Jianwen
2015-01-01
Dynamic fluorescence molecular tomography (DFMT) is a potential approach for drug delivery, tumor detection, diagnosis, and staging. The purpose of DFMT is to quantify the changes of fluorescent agents in the bodies, which offer important information about the underlying physiological processes. However, the conventional method requires that the fluorophore concentrations to be reconstructed are stationary during the data collection period. As thus, it cannot offer the dynamic information of fluorophore concentration variation within the data collection period. In this paper, a method is proposed to reconstruct the fluorophore concentration variation instead of the fluorophore concentration through a linear approximation. The fluorophore concentration variation rate is introduced by the linear approximation as a new unknown term to be reconstructed and is used to obtain the time courses of fluorophore concentration. Simulation and phantom studies are performed to validate the proposed method. The results show that the method is able to reconstruct the fluorophore concentration variation rates and the time courses of fluorophore concentration with relative errors less than 0.0218.
-
Effects of obstruent consonants on the F0 contour
NASA Astrophysics Data System (ADS)
Hanson, Helen M.
2003-10-01
When a vowel follows an obstruent consonant, the fundamental frequency in the first few tens of milliseconds of the vowel is influenced by the voicing characteristics of the consonant. The goal of the research reported here is to model this influence, with the intention of improving generation of F0 contours in rule-based speech synthesis. Data have been recorded from 10 subjects. Stops, fricatives, and the nasal /m/ were paired with the vowels /i,opena/ to form CVm syllables. The syllables mVm served as baselines with which to compare the obstruents. The target syllables were embedded in carrier sentences. Intonation was varied so that each target syllable was produced with either a high, low, or no pitch accent. Results vary among subjects, but in general, obstruent effects on F0 primarily occur when the syllable carries a high pitch. In that case, F0 is increased relative to the baseline following voiceless obstruents, but F0 closely follows the baseline following voiced obstruents. After voiceless obstruents, F0 may be increased for up to 80 ms following voicing onset. When a syllable carries a low or no pitch accent, F0 is increased slightly following all obstruents. [Work supported by NIH Grant No. DC04331.
-
On the structure of negative-parity states in 66Zn and 70Ge
NASA Astrophysics Data System (ADS)
Cleemann, L.; Eberth, J.; Neumann, W.; Zobel, V.
1982-09-01
Mean lifetimes of negative-parity states in 66Zn and 70Ge have been measured using the recoil distance Doppler shift technique. The states in 66Zn have been studied through the reaction 55Mn( 14N, 2pnγ) 66Zn at E = 47 MeV, those in 70Ge through the reaction 56Fe( 16O, 2pγ) 70Ge at E = 46 MeV. The measurements were performed with a plunger apparatus with a piezo-electric distance regulation. The mean lifetimes in 66Zn were measured to be 66 ± 4ps (5 - state), 43 ± 2 ps (6 - state), 192 ± 15 ps (7 - state), and 2.7 ± 1.2 ps (9 - state), those of 70Ge 19.7 ± 2 ps (5 - state), 51 ± 4 ps (6 - state), and 25.2 ± 1.4 ps (7 - state). Deduced B ( Ml) and B( E2) values are compared with theoretical predictions of a two-proton cluster-vibration coupling model (CVM) which describes these states as couplings of g {9}/{2} ⊗ (fp shell) proton clusters to zero, one and higher phonon excitations of the corresponding Ni and Zn cores. Good overall agreement between the theoretical values and the experimental data was found.
-
Nielsen, Marie Katrine Klose; Johansen, Sys Stybe; Linnet, Kristian
2014-01-01
Assessment of total uncertainty of analytical methods for the measurements of drugs in human hair has mainly been derived from the analytical variation. However, in hair analysis several other sources of uncertainty will contribute to the total uncertainty. Particularly, in segmental hair analysis pre-analytical variations associated with the sampling and segmentation may be significant factors in the assessment of the total uncertainty budget. The aim of this study was to develop and validate a method for the analysis of 31 common drugs in hair using ultra-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) with focus on the assessment of both the analytical and pre-analytical sampling variations. The validated method was specific, accurate (80-120%), and precise (CV≤20%) across a wide linear concentration range from 0.025-25 ng/mg for most compounds. The analytical variation was estimated to be less than 15% for almost all compounds. The method was successfully applied to 25 segmented hair specimens from deceased drug addicts showing a broad pattern of poly-drug use. The pre-analytical sampling variation was estimated from the genuine duplicate measurements of two bundles of hair collected from each subject after subtraction of the analytical component. For the most frequently detected analytes, the pre-analytical variation was estimated to be 26-69%. Thus, the pre-analytical variation was 3-7 folds larger than the analytical variation (7-13%) and hence the dominant component in the total variation (29-70%). The present study demonstrated the importance of including the pre-analytical variation in the assessment of the total uncertainty budget and in the setting of the 95%-uncertainty interval (±2CVT). Excluding the pre-analytical sampling variation could significantly affect the interpretation of results from segmental hair analysis. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.
-
Yoshida, Hiroyuki; Shibata, Hiroko; Izutsu, Ken-Ichi; Goda, Yukihiro
2017-01-01
The current Japanese Ministry of Health Labour and Welfare (MHLW)'s Guideline for Bioequivalence Studies of Generic Products uses averaged dissolution rates for the assessment of dissolution similarity between test and reference formulations. This study clarifies how the application of model-independent multivariate confidence region procedure (Method B), described in the European Medical Agency and U.S. Food and Drug Administration guidelines, affects similarity outcomes obtained empirically from dissolution profiles with large variations in individual dissolution rates. Sixty-one datasets of dissolution profiles for immediate release, oral generic, and corresponding innovator products that showed large variation in individual dissolution rates in generic products were assessed on their similarity by using the f 2 statistics defined in the MHLW guidelines (MHLW f 2 method) and two different Method B procedures, including a bootstrap method applied with f 2 statistics (BS method) and a multivariate analysis method using the Mahalanobis distance (MV method). The MHLW f 2 and BS methods provided similar dissolution similarities between reference and generic products. Although a small difference in the similarity assessment may be due to the decrease in the lower confidence interval for expected f 2 values derived from the large variation in individual dissolution rates, the MV method provided results different from those obtained through MHLW f 2 and BS methods. Analysis of actual dissolution data for products with large individual variations would provide valuable information towards an enhanced understanding of these methods and their possible incorporation in the MHLW guidelines.
-
NASA Astrophysics Data System (ADS)
Zhong, Qiu-Xiang; Wu, Chuan-Sheng; Shu, Qiao-Ling; Liu, Ryan Wen
2018-04-01
Image deblurring under impulse noise is a typical ill-posed problem which requires regularization methods to guarantee high-quality imaging. L1-norm data-fidelity term and total variation (TV) regularizer have been combined to contribute the popular regularization method. However, the TV-regularized variational image deblurring model often suffers from the staircase-like artifacts leading to image quality degradation. To enhance image quality, the detailpreserving total generalized variation (TGV) was introduced to replace TV to eliminate the undesirable artifacts. The resulting nonconvex optimization problem was effectively solved using the alternating direction method of multipliers (ADMM). In addition, an automatic method for selecting spatially adapted regularization parameters was proposed to further improve deblurring performance. Our proposed image deblurring framework is able to remove blurring and impulse noise effects while maintaining the image edge details. Comprehensive experiments have been conducted to demonstrate the superior performance of our proposed method over several state-of-the-art image deblurring methods.
-
NASA Technical Reports Server (NTRS)
Roth, Don J.
1996-01-01
This article describes a single transducer ultrasonic imaging method that eliminates the effect of plate thickness variation in the image. The method thus isolates ultrasonic variations due to material microstructure. The use of this method can result in significant cost savings because the ultrasonic image can be interpreted correctly without the need for machining to achieve precise thickness uniformity during nondestructive evaluations of material development. The method is based on measurement of ultrasonic velocity. Images obtained using the thickness-independent methodology are compared with conventional velocity and c-scan echo peak amplitude images for monolithic ceramic (silicon nitride), metal matrix composite and polymer matrix composite materials. It was found that the thickness-independent ultrasonic images reveal and quantify correctly areas of global microstructural (pore and fiber volume fraction) variation due to the elimination of thickness effects. The thickness-independent ultrasonic imaging method described in this article is currently being commercialized under a cooperative agreement between NASA Lewis Research Center and Sonix, Inc.
-
Alternative to the Palatini method: A new variational principle
DOE Office of Scientific and Technical Information (OSTI.GOV)
Goenner, Hubert
2010-06-15
A variational principle is suggested within Riemannian geometry, in which an auxiliary metric and the Levi Civita connection are varied independently. The auxiliary metric plays the role of a Lagrange multiplier and introduces nonminimal coupling of matter to the curvature scalar. The field equations are 2nd order PDEs and easier to handle than those following from the so-called Palatini method. Moreover, in contrast to the latter method, no gradients of the matter variables appear. In cosmological modeling, the physics resulting from the alternative variational principle will differ from the modeling using the standard Palatini method.
-
Hints of correlation between broad-line and radio variations for 3C 120
DOE Office of Scientific and Technical Information (OSTI.GOV)
Liu, H. T.; Bai, J. M.; Li, S. K.
2014-01-01
In this paper, we investigate the correlation between broad-line and radio variations for the broad-line radio galaxy 3C 120. By the z-transformed discrete correlation function method and the model-independent flux randomization/random subset selection (FR/RSS) Monte Carlo method, we find that broad Hβ line variations lead the 15 GHz variations. The FR/RSS method shows that the Hβ line variations lead the radio variations by a factor of τ{sub ob} = 0.34 ± 0.01 yr. This time lag can be used to locate the position of the emitting region of radio outbursts in the jet, on the order of ∼5 lt-yr frommore » the central engine. This distance is much larger than the size of the broad-line region. The large separation of the radio outburst emitting region from the broad-line region will observably influence the gamma-ray emission in 3C 120.« less
-
Boareto, Marcelo; Cesar, Jonatas; Leite, Vitor B P; Caticha, Nestor
2015-01-01
We introduce Supervised Variational Relevance Learning (Suvrel), a variational method to determine metric tensors to define distance based similarity in pattern classification, inspired in relevance learning. The variational method is applied to a cost function that penalizes large intraclass distances and favors small interclass distances. We find analytically the metric tensor that minimizes the cost function. Preprocessing the patterns by doing linear transformations using the metric tensor yields a dataset which can be more efficiently classified. We test our methods using publicly available datasets, for some standard classifiers. Among these datasets, two were tested by the MAQC-II project and, even without the use of further preprocessing, our results improve on their performance.
-
A Finite Mixture Method for Outlier Detection and Robustness in Meta-Analysis
ERIC Educational Resources Information Center
Beath, Ken J.
2014-01-01
When performing a meta-analysis unexplained variation above that predicted by within study variation is usually modeled by a random effect. However, in some cases, this is not sufficient to explain all the variation because of outlier or unusual studies. A previously described method is to define an outlier as a study requiring a higher random…
-
A variationally coupled FE-BE method for elasticity and fracture mechanics
NASA Technical Reports Server (NTRS)
Lu, Y. Y.; Belytschko, T.; Liu, W. K.
1991-01-01
A new method for coupling finite element and boundary element subdomains in elasticity and fracture mechanics problems is described. The essential feature of this new method is that a single variational statement is obtained for the entire domain, and in this process the terms associated with tractions on the interfaces between the subdomains are eliminated. This provides the additional advantage that the ambiguities associated with the matching of discontinuous tractions are circumvented. The method leads to a direct procedure for obtaining the discrete equations for the coupled problem without any intermediate steps. In order to evaluate this method and compare it with previous methods, a patch test for coupled procedures has been devised. Evaluation of this variationally coupled method and other methods, such as stiffness coupling and constraint traction matching coupling, shows that this method is substantially superior. Solutions for a series of fracture mechanics problems are also reported to illustrate the effectiveness of this method.
-
NASA Astrophysics Data System (ADS)
Libarir, K.; Zerarka, A.
2018-05-01
Exact eigenspectra and eigenfunctions of the Dirac quantum equation are established using the semi-inverse variational method. This method improves of a considerable manner the efficiency and accuracy of results compared with the other usual methods much argued in the literature. Some applications for different state configurations are proposed to concretize the method.
-
NASA Astrophysics Data System (ADS)
Li, Y. Chao; Ding, Q.; Gao, Y.; Ran, L. Ling; Yang, J. Ru; Liu, C. Yu; Wang, C. Hui; Sun, J. Feng
2014-07-01
This paper proposes a novel method of multi-beam laser heterodyne measurement for Young modulus. Based on Doppler effect and heterodyne technology, loaded the information of length variation to the frequency difference of the multi-beam laser heterodyne signal by the frequency modulation of the oscillating mirror, this method can obtain many values of length variation caused by mass variation after the multi-beam laser heterodyne signal demodulation simultaneously. Processing these values by weighted-average, it can obtain length variation accurately, and eventually obtain value of Young modulus of the sample by the calculation. This novel method is used to simulate measurement for Young modulus of wire under different mass by MATLAB, the obtained result shows that the relative measurement error of this method is just 0.3%.
-
Aghamohammadi, Amirhossein; Ang, Mei Choo; A Sundararajan, Elankovan; Weng, Ng Kok; Mogharrebi, Marzieh; Banihashem, Seyed Yashar
2018-01-01
Visual tracking in aerial videos is a challenging task in computer vision and remote sensing technologies due to appearance variation difficulties. Appearance variations are caused by camera and target motion, low resolution noisy images, scale changes, and pose variations. Various approaches have been proposed to deal with appearance variation difficulties in aerial videos, and amongst these methods, the spatiotemporal saliency detection approach reported promising results in the context of moving target detection. However, it is not accurate for moving target detection when visual tracking is performed under appearance variations. In this study, a visual tracking method is proposed based on spatiotemporal saliency and discriminative online learning methods to deal with appearance variations difficulties. Temporal saliency is used to represent moving target regions, and it was extracted based on the frame difference with Sauvola local adaptive thresholding algorithms. The spatial saliency is used to represent the target appearance details in candidate moving regions. SLIC superpixel segmentation, color, and moment features can be used to compute feature uniqueness and spatial compactness of saliency measurements to detect spatial saliency. It is a time consuming process, which prompted the development of a parallel algorithm to optimize and distribute the saliency detection processes that are loaded into the multi-processors. Spatiotemporal saliency is then obtained by combining the temporal and spatial saliencies to represent moving targets. Finally, a discriminative online learning algorithm was applied to generate a sample model based on spatiotemporal saliency. This sample model is then incrementally updated to detect the target in appearance variation conditions. Experiments conducted on the VIVID dataset demonstrated that the proposed visual tracking method is effective and is computationally efficient compared to state-of-the-art methods.
-
2018-01-01
Visual tracking in aerial videos is a challenging task in computer vision and remote sensing technologies due to appearance variation difficulties. Appearance variations are caused by camera and target motion, low resolution noisy images, scale changes, and pose variations. Various approaches have been proposed to deal with appearance variation difficulties in aerial videos, and amongst these methods, the spatiotemporal saliency detection approach reported promising results in the context of moving target detection. However, it is not accurate for moving target detection when visual tracking is performed under appearance variations. In this study, a visual tracking method is proposed based on spatiotemporal saliency and discriminative online learning methods to deal with appearance variations difficulties. Temporal saliency is used to represent moving target regions, and it was extracted based on the frame difference with Sauvola local adaptive thresholding algorithms. The spatial saliency is used to represent the target appearance details in candidate moving regions. SLIC superpixel segmentation, color, and moment features can be used to compute feature uniqueness and spatial compactness of saliency measurements to detect spatial saliency. It is a time consuming process, which prompted the development of a parallel algorithm to optimize and distribute the saliency detection processes that are loaded into the multi-processors. Spatiotemporal saliency is then obtained by combining the temporal and spatial saliencies to represent moving targets. Finally, a discriminative online learning algorithm was applied to generate a sample model based on spatiotemporal saliency. This sample model is then incrementally updated to detect the target in appearance variation conditions. Experiments conducted on the VIVID dataset demonstrated that the proposed visual tracking method is effective and is computationally efficient compared to state-of-the-art methods. PMID:29438421
-
27 CFR 22.22 - Alternate methods or procedures; and emergency variations from requirements.
Code of Federal Regulations, 2012 CFR
2012-04-01
... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Alternate methods or procedures; and emergency variations from requirements. 22.22 Section 22.22 Alcohol, Tobacco Products and... OF TAX-FREE ALCOHOL Administrative Provisions Authorities § 22.22 Alternate methods or procedures...
-
27 CFR 22.22 - Alternate methods or procedures; and emergency variations from requirements.
Code of Federal Regulations, 2014 CFR
2014-04-01
... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Alternate methods or procedures; and emergency variations from requirements. 22.22 Section 22.22 Alcohol, Tobacco Products and... OF TAX-FREE ALCOHOL Administrative Provisions Authorities § 22.22 Alternate methods or procedures...
-
27 CFR 22.22 - Alternate methods or procedures; and emergency variations from requirements.
Code of Federal Regulations, 2011 CFR
2011-04-01
... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Alternate methods or procedures; and emergency variations from requirements. 22.22 Section 22.22 Alcohol, Tobacco Products and... OF TAX-FREE ALCOHOL Administrative Provisions Authorities § 22.22 Alternate methods or procedures...
-
27 CFR 22.22 - Alternate methods or procedures; and emergency variations from requirements.
Code of Federal Regulations, 2013 CFR
2013-04-01
... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Alternate methods or procedures; and emergency variations from requirements. 22.22 Section 22.22 Alcohol, Tobacco Products and... OF TAX-FREE ALCOHOL Administrative Provisions Authorities § 22.22 Alternate methods or procedures...
-
27 CFR 22.22 - Alternate methods or procedures; and emergency variations from requirements.
Code of Federal Regulations, 2010 CFR
2010-04-01
... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Alternate methods or procedures; and emergency variations from requirements. 22.22 Section 22.22 Alcohol, Tobacco Products and... OF TAX-FREE ALCOHOL Administrative Provisions Authorities § 22.22 Alternate methods or procedures...
-
Resolving Rapid Variation in Energy for Particle Transport
DOE Office of Scientific and Technical Information (OSTI.GOV)
Haut, Terry Scot; Ahrens, Cory Douglas; Jonko, Alexandra
2016-08-23
Resolving the rapid variation in energy in neutron and thermal radiation transport is needed for the predictive simulation capability in high-energy density physics applications. Energy variation is difficult to resolve due to rapid variations in cross sections and opacities caused by quantized energy levels in the nuclei and electron clouds. In recent work, we have developed a new technique to simultaneously capture slow and rapid variations in the opacities and the solution using homogenization theory, which is similar to multiband (MB) and to the finite-element with discontiguous support (FEDS) method, but does not require closure information. We demonstrated the accuracymore » and efficiency of the method for a variety of problems. We are researching how to extend the method to problems with multiple materials and the same material but with different temperatures and densities. In this highlight, we briefly describe homogenization theory and some results.« less
-
Some problems in applications of the linear variational method
NASA Astrophysics Data System (ADS)
Pupyshev, Vladimir I.; Montgomery, H. E.
2015-09-01
The linear variational method is a standard computational method in quantum mechanics and quantum chemistry. As taught in most classes, the general guidance is to include as many basis functions as practical in the variational wave function. However, if it is desired to study the patterns of energy change accompanying the change of system parameters such as the shape and strength of the potential energy, the problem becomes more complicated. We use one-dimensional systems with a particle in a rectangular or in a harmonic potential confined in an infinite rectangular box to illustrate situations where a variational calculation can give incorrect results. These situations result when the energy of the lowest eigenvalue is strongly dependent on the parameters that describe the shape and strength of the potential. The numerical examples described in this work are provided as cautionary notes for practitioners of numerical variational calculations.
-
Make no mistake—errors can be controlled*
Hinckley, C
2003-01-01
Traditional quality control methods identify "variation" as the enemy. However, the control of variation by itself can never achieve the remarkably low non-conformance rates of world class quality leaders. Because the control of variation does not achieve the highest levels of quality, an inordinate focus on these techniques obscures key quality improvement opportunities and results in unnecessary pain and suffering for patients, and embarrassment, litigation, and loss of revenue for healthcare providers. Recent experience has shown that mistakes are the most common cause of problems in health care as well as in other industrial environments. Excessive product and process complexity contributes to both excessive variation and unnecessary mistakes. The best methods for controlling variation, mistakes, and complexity are each a form of mistake proofing. Using these mistake proofing techniques, virtually every mistake and non-conformance can be controlled at a fraction of the cost of traditional quality control methods. PMID:14532368
-
Variational Algorithms for Test Particle Trajectories
NASA Astrophysics Data System (ADS)
Ellison, C. Leland; Finn, John M.; Qin, Hong; Tang, William M.
2015-11-01
The theory of variational integration provides a novel framework for constructing conservative numerical methods for magnetized test particle dynamics. The retention of conservation laws in the numerical time advance captures the correct qualitative behavior of the long time dynamics. For modeling the Lorentz force system, new variational integrators have been developed that are both symplectic and electromagnetically gauge invariant. For guiding center test particle dynamics, discretization of the phase-space action principle yields multistep variational algorithms, in general. Obtaining the desired long-term numerical fidelity requires mitigation of the multistep method's parasitic modes or applying a discretization scheme that possesses a discrete degeneracy to yield a one-step method. Dissipative effects may be modeled using Lagrange-D'Alembert variational principles. Numerical results will be presented using a new numerical platform that interfaces with popular equilibrium codes and utilizes parallel hardware to achieve reduced times to solution. This work was supported by DOE Contract DE-AC02-09CH11466.
-
A parametric method for assessing diversification-rate variation in phylogenetic trees.
Shah, Premal; Fitzpatrick, Benjamin M; Fordyce, James A
2013-02-01
Phylogenetic hypotheses are frequently used to examine variation in rates of diversification across the history of a group. Patterns of diversification-rate variation can be used to infer underlying ecological and evolutionary processes responsible for patterns of cladogenesis. Most existing methods examine rate variation through time. Methods for examining differences in diversification among groups are more limited. Here, we present a new method, parametric rate comparison (PRC), that explicitly compares diversification rates among lineages in a tree using a variety of standard statistical distributions. PRC can identify subclades of the tree where diversification rates are at variance with the remainder of the tree. A randomization test can be used to evaluate how often such variance would appear by chance alone. The method also allows for comparison of diversification rate among a priori defined groups. Further, the application of the PRC method is not restricted to monophyletic groups. We examined the performance of PRC using simulated data, which showed that PRC has acceptable false-positive rates and statistical power to detect rate variation. We apply the PRC method to the well-studied radiation of North American Plethodon salamanders, and support the inference that the large-bodied Plethodon glutinosus clade has a higher historical rate of diversification compared to other Plethodon salamanders. © 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.
-
Hamilton's Principle and Approximate Solutions to Problems in Classical Mechanics
ERIC Educational Resources Information Center
Schlitt, D. W.
1977-01-01
Shows how to use the Ritz method for obtaining approximate solutions to problems expressed in variational form directly from the variational equation. Application of this method to classical mechanics is given. (MLH)
-
NASA Technical Reports Server (NTRS)
Roth, Don J.; Seebo, Jeffrey P.; Winfree, William P.
2008-01-01
This article describes a noncontact single-sided terahertz electromagnetic measurement and imaging method that simultaneously characterizes microstructural (egs. spatially-lateral density) and thickness variation in dielectric (insulating) materials. The method was demonstrated for two materials-Space Shuttle External Tank sprayed-on foam insulation and a silicon nitride ceramic. It is believed that this method can be used as an inspection method for current and future NASA thermal protection system and other dielectric material inspection applications, where microstructural and thickness variation require precision mapping. Scale-up to more complex shapes such as cylindrical structures and structures with beveled regions would appear to be feasible.
-
Nonperturbative calculations in the framework of variational perturbation theory in QCD
NASA Astrophysics Data System (ADS)
Solovtsova, O. P.
2017-07-01
We discuss applications of the method based on the variational perturbation theory to perform calculations down to the lowest energy scale. The variational series is different from the conventional perturbative expansion and can be used to go beyond the weak-coupling regime. We apply this method to investigate the Borel representation of the light Adler function constructed from the τ data and to determine the residual condensates. It is shown that within the method suggested the optimal values of these lower dimension condensates are close to zero.
-
Zhao, Jiang Yan; Xie, Ping; Sang, Yan Fang; Xui, Qiang Qiang; Wu, Zi Yi
2018-04-01
Under the influence of both global climate change and frequent human activities, the variability of second-moment in hydrological time series become obvious, indicating changes in the consistency of hydrological data samples. Therefore, the traditional hydrological series analysis methods, which only consider the variability of mean values, are not suitable for handling all hydrological non-consistency problems. Traditional synthetic duration curve methods for the design of the lowest navigable water level, based on the consistency of samples, would cause more risks to navigation, especially under low water level in dry seasons. Here, we detected both mean variation and variance variation using the hydrological variation diagnosis system. Furthermore, combing the principle of decomposition and composition of time series, we proposed the synthetic duration curve method for designing the lowest navigable water level with inconsistent characters in dry seasons. With the Yunjinghong Station in the Lancang River Basin as an example, we analyzed its designed water levels in the present, the distant past and the recent past, as well as the differences among three situations (i.e., considering second moment variation, only considering mean variation, not considering any variation). Results showed that variability of the second moment changed the trend of designed water levels alteration in the Yunjinghong Station. When considering the first two moments or just considering the mean variation, the difference ofdesigned water levels was as bigger as -1.11 m. When considering the first two moments or not, the difference of designed water levels was as bigger as -1.01 m. Our results indicated the strong effects of variance variation on the designed water levels, and highlighted the importance of the second moment variation analysis for the channel planning and design.
-
CNV-seq, a new method to detect copy number variation using high-throughput sequencing.
Xie, Chao; Tammi, Martti T
2009-03-06
DNA copy number variation (CNV) has been recognized as an important source of genetic variation. Array comparative genomic hybridization (aCGH) is commonly used for CNV detection, but the microarray platform has a number of inherent limitations. Here, we describe a method to detect copy number variation using shotgun sequencing, CNV-seq. The method is based on a robust statistical model that describes the complete analysis procedure and allows the computation of essential confidence values for detection of CNV. Our results show that the number of reads, not the length of the reads is the key factor determining the resolution of detection. This favors the next-generation sequencing methods that rapidly produce large amount of short reads. Simulation of various sequencing methods with coverage between 0.1x to 8x show overall specificity between 91.7 - 99.9%, and sensitivity between 72.2 - 96.5%. We also show the results for assessment of CNV between two individual human genomes.
-
Removal of ring artifacts in microtomography by characterization of scintillator variations.
Vågberg, William; Larsson, Jakob C; Hertz, Hans M
2017-09-18
Ring artifacts reduce image quality in tomography, and arise from faulty detector calibration. In microtomography, we have identified that ring artifacts can arise due to high-spatial frequency variations in the scintillator thickness. Such variations are normally removed by a flat-field correction. However, as the spectrum changes, e.g. due to beam hardening, the detector response varies non-uniformly introducing ring artifacts that persist after flat-field correction. In this paper, we present a method to correct for ring artifacts from variations in scintillator thickness by using a simple method to characterize the local scintillator response. The method addresses the actual physical cause of the ring artifacts, in contrary to many other ring artifact removal methods which rely only on image post-processing. By applying the technique to an experimental phantom tomography, we show that ring artifacts are strongly reduced compared to only making a flat-field correction.
-
Localization of a variational particle smoother
NASA Astrophysics Data System (ADS)
Morzfeld, M.; Hodyss, D.; Poterjoy, J.
2017-12-01
Given the success of 4D-variational methods (4D-Var) in numerical weather prediction,and recent efforts to merge ensemble Kalman filters with 4D-Var,we consider a method to merge particle methods and 4D-Var.This leads us to revisit variational particle smoothers (varPS).We study the collapse of varPS in high-dimensional problemsand show how it can be prevented by weight-localization.We test varPS on the Lorenz'96 model of dimensionsn=40, n=400, and n=2000.In our numerical experiments, weight localization prevents the collapse of the varPS,and we note that the varPS yields results comparable to ensemble formulations of 4D-variational methods,while it outperforms EnKF with tuned localization and inflation,and the localized standard particle filter.Additional numerical experiments suggest that using localized weights in varPS may not yield significant advantages over unweighted or linearizedsolutions in near-Gaussian problems.
-
NASA Astrophysics Data System (ADS)
Li, Yan-Chao; Wang, Chun-Hui; Qu, Yang; Gao, Long; Cong, Hai-Fang; Yang, Yan-Ling; Gao, Jie; Wang, Ao-You
2011-01-01
This paper proposes a novel method of multi-beam laser heterodyne measurement for metal linear expansion coefficient. Based on the Doppler effect and heterodyne technology, the information is loaded of length variation to the frequency difference of the multi-beam laser heterodyne signal by the frequency modulation of the oscillating mirror, this method can obtain many values of length variation caused by temperature variation after the multi-beam laser heterodyne signal demodulation simultaneously. Processing these values by weighted-average, it can obtain length variation accurately, and eventually obtain the value of linear expansion coefficient of metal by the calculation. This novel method is used to simulate measurement for linear expansion coefficient of metal rod under different temperatures by MATLAB, the obtained result shows that the relative measurement error of this method is just 0.4%.
-
Wu, Gary D; Lewis, James D; Hoffmann, Christian; Chen, Ying-Yu; Knight, Rob; Bittinger, Kyle; Hwang, Jennifer; Chen, Jun; Berkowsky, Ronald; Nessel, Lisa; Li, Hongzhe; Bushman, Frederic D
2010-07-30
Intense interest centers on the role of the human gut microbiome in health and disease, but optimal methods for analysis are still under development. Here we present a study of methods for surveying bacterial communities in human feces using 454/Roche pyrosequencing of 16S rRNA gene tags. We analyzed fecal samples from 10 individuals and compared methods for storage, DNA purification and sequence acquisition. To assess reproducibility, we compared samples one cm apart on a single stool specimen for each individual. To analyze storage methods, we compared 1) immediate freezing at -80 degrees C, 2) storage on ice for 24 or 3) 48 hours. For DNA purification methods, we tested three commercial kits and bead beating in hot phenol. Variations due to the different methodologies were compared to variation among individuals using two approaches--one based on presence-absence information for bacterial taxa (unweighted UniFrac) and the other taking into account their relative abundance (weighted UniFrac). In the unweighted analysis relatively little variation was associated with the different analytical procedures, and variation between individuals predominated. In the weighted analysis considerable variation was associated with the purification methods. Particularly notable was improved recovery of Firmicutes sequences using the hot phenol method. We also carried out surveys of the effects of different 454 sequencing methods (FLX versus Titanium) and amplification of different 16S rRNA variable gene segments. Based on our findings we present recommendations for protocols to collect, process and sequence bacterial 16S rDNA from fecal samples--some major points are 1) if feasible, bead-beating in hot phenol or use of the PSP kit improves recovery; 2) storage methods can be adjusted based on experimental convenience; 3) unweighted (presence-absence) comparisons are less affected by lysis method.
-
An Analysis of Periodic Components in BL Lac Object S5 0716 +714 with MUSIC Method
NASA Astrophysics Data System (ADS)
Tang, J.
2012-01-01
Multiple signal classification (MUSIC) algorithms are introduced to the estimation of the period of variation of BL Lac objects.The principle of MUSIC spectral analysis method and theoretical analysis of the resolution of frequency spectrum using analog signals are included. From a lot of literatures, we have collected a lot of effective observation data of BL Lac object S5 0716 + 714 in V, R, I bands from 1994 to 2008. The light variation periods of S5 0716 +714 are obtained by means of the MUSIC spectral analysis method and periodogram spectral analysis method. There exist two major periods: (3.33±0.08) years and (1.24±0.01) years for all bands. The estimation of the period of variation of the algorithm based on the MUSIC spectral analysis method is compared with that of the algorithm based on the periodogram spectral analysis method. It is a super-resolution algorithm with small data length, and could be used to detect the period of variation of weak signals.
-
Optimal Variational Asymptotic Method for Nonlinear Fractional Partial Differential Equations.
Baranwal, Vipul K; Pandey, Ram K; Singh, Om P
2014-01-01
We propose optimal variational asymptotic method to solve time fractional nonlinear partial differential equations. In the proposed method, an arbitrary number of auxiliary parameters γ 0, γ 1, γ 2,… and auxiliary functions H 0(x), H 1(x), H 2(x),… are introduced in the correction functional of the standard variational iteration method. The optimal values of these parameters are obtained by minimizing the square residual error. To test the method, we apply it to solve two important classes of nonlinear partial differential equations: (1) the fractional advection-diffusion equation with nonlinear source term and (2) the fractional Swift-Hohenberg equation. Only few iterations are required to achieve fairly accurate solutions of both the first and second problems.
-
NASA Technical Reports Server (NTRS)
Horvitz, M. A.; Schoeller, D. A.
2001-01-01
The doubly labeled water method for measuring total energy expenditure is subject to error from natural variations in the background 2H and 18O in body water. There is disagreement as to whether the variations in background abundances of the two stable isotopes covary and what relative doses of 2H and 18O minimize the impact of variation on the precision of the method. We have performed two studies to investigate the amount and covariance of the background variations. These were a study of urine collected weekly from eight subjects who remained in the Madison, WI locale for 6 wk and frequent urine samples from 14 subjects during round-trip travel to a locale > or = 500 miles from Madison, WI. Background variation in excess of analytical error was detected in six of the eight nontravelers, and covariance was demonstrated in four subjects. Background variation was detected in all 14 travelers, and covariance was demonstrated in 11 subjects. The median slopes of the regression lines of delta2H vs. delta18O were 6 and 7, respectively. Modeling indicated that 2H and 18O doses yielding a 6:1 ratio of final enrichments should minimize this error introduced to the doubly labeled water method.
-
Horvitz, M A; Schoeller, D A
2001-06-01
The doubly labeled water method for measuring total energy expenditure is subject to error from natural variations in the background 2H and 18O in body water. There is disagreement as to whether the variations in background abundances of the two stable isotopes covary and what relative doses of 2H and 18O minimize the impact of variation on the precision of the method. We have performed two studies to investigate the amount and covariance of the background variations. These were a study of urine collected weekly from eight subjects who remained in the Madison, WI locale for 6 wk and frequent urine samples from 14 subjects during round-trip travel to a locale > or = 500 miles from Madison, WI. Background variation in excess of analytical error was detected in six of the eight nontravelers, and covariance was demonstrated in four subjects. Background variation was detected in all 14 travelers, and covariance was demonstrated in 11 subjects. The median slopes of the regression lines of delta2H vs. delta18O were 6 and 7, respectively. Modeling indicated that 2H and 18O doses yielding a 6:1 ratio of final enrichments should minimize this error introduced to the doubly labeled water method.
-
An improved correlation method for determining the period of a torsion pendulum
DOE Office of Scientific and Technical Information (OSTI.GOV)
Luo Jie; Wang Dianhong
Considering variation of environment temperature and unhomogeneity of background gravitational field, an improved correlation method was proposed to determine the variational period of a torsion pendulum with high precision. The result of processing experimental data shows that the uncertainty of determining the period with this method has been improved about twofolds than traditional correlation method, which is significant for the determination of gravitational constant with time-of-swing method.
-
Partitioning sources of variation in vertebrate species richness
Boone, R.B.; Krohn, W.B.
2000-01-01
Aim: To explore biogeographic patterns of terrestrial vertebrates in Maine, USA using techniques that would describe local and spatial correlations with the environment. Location: Maine, USA. Methods: We delineated the ranges within Maine (86,156 km2) of 275 species using literature and expert review. Ranges were combined into species richness maps, and compared to geomorphology, climate, and woody plant distributions. Methods were adapted that compared richness of all vertebrate classes to each environmental correlate, rather than assessing a single explanatory theory. We partitioned variation in species richness into components using tree and multiple linear regression. Methods were used that allowed for useful comparisons between tree and linear regression results. For both methods we partitioned variation into broad-scale (spatially autocorrelated) and fine-scale (spatially uncorrelated) explained and unexplained components. By partitioning variance, and using both tree and linear regression in analyses, we explored the degree of variation in species richness for each vertebrate group that Could be explained by the relative contribution of each environmental variable. Results: In tree regression, climate variation explained richness better (92% of mean deviance explained for all species) than woody plant variation (87%) and geomorphology (86%). Reptiles were highly correlated with environmental variation (93%), followed by mammals, amphibians, and birds (each with 84-82% deviance explained). In multiple linear regression, climate was most closely associated with total vertebrate richness (78%), followed by woody plants (67%) and geomorphology (56%). Again, reptiles were closely correlated with the environment (95%), followed by mammals (73%), amphibians (63%) and birds (57%). Main conclusions: Comparing variation explained using tree and multiple linear regression quantified the importance of nonlinear relationships and local interactions between species richness and environmental variation, identifying the importance of linear relationships between reptiles and the environment, and nonlinear relationships between birds and woody plants, for example. Conservation planners should capture climatic variation in broad-scale designs; temperatures may shift during climate change, but the underlying correlations between the environment and species richness will presumably remain.
-
Methods of determining complete sensor requirements for autonomous mobility
NASA Technical Reports Server (NTRS)
Curtis, Steven A. (Inventor)
2012-01-01
A method of determining complete sensor requirements for autonomous mobility of an autonomous system includes computing a time variation of each behavior of a set of behaviors of the autonomous system, determining mobility sensitivity to each behavior of the autonomous system, and computing a change in mobility based upon the mobility sensitivity to each behavior and the time variation of each behavior. The method further includes determining the complete sensor requirements of the autonomous system through analysis of the relative magnitude of the change in mobility, the mobility sensitivity to each behavior, and the time variation of each behavior, wherein the relative magnitude of the change in mobility, the mobility sensitivity to each behavior, and the time variation of each behavior are characteristic of the stability of the autonomous system.
-
The Schwinger Variational Method
NASA Technical Reports Server (NTRS)
Huo, Winifred M.
1995-01-01
Variational methods have proven invaluable in theoretical physics and chemistry, both for bound state problems and for the study of collision phenomena. The application of the Schwinger variational (SV) method to e-molecule collisions and molecular photoionization has been reviewed previously. The present chapter discusses the implementation of the SV method as applied to e-molecule collisions. Since this is not a review of cross section data, cross sections are presented only to server as illustrative examples. In the SV method, the correct boundary condition is automatically incorporated through the use of Green's function. Thus SV calculations can employ basis functions with arbitrary boundary conditions. The iterative Schwinger method has been used extensively to study molecular photoionization. For e-molecule collisions, it is used at the static exchange level to study elastic scattering and coupled with the distorted wave approximation to study electronically inelastic scattering.
-
Factor Retention in Exploratory Factor Analysis: A Comparison of Alternative Methods.
ERIC Educational Resources Information Center
Mumford, Karen R.; Ferron, John M.; Hines, Constance V.; Hogarty, Kristine Y.; Kromrey, Jeffery D.
This study compared the effectiveness of 10 methods of determining the number of factors to retain in exploratory common factor analysis. The 10 methods included the Kaiser rule and a modified Kaiser criterion, 3 variations of parallel analysis, 4 regression-based variations of the scree procedure, and the minimum average partial procedure. The…
-
NASA Astrophysics Data System (ADS)
Ponte Castañeda, Pedro
2016-11-01
This paper presents a variational method for estimating the effective constitutive response of composite materials with nonlinear constitutive behavior. The method is based on a stationary variational principle for the macroscopic potential in terms of the corresponding potential of a linear comparison composite (LCC) whose properties are the trial fields in the variational principle. When used in combination with estimates for the LCC that are exact to second order in the heterogeneity contrast, the resulting estimates for the nonlinear composite are also guaranteed to be exact to second-order in the contrast. In addition, the new method allows full optimization with respect to the properties of the LCC, leading to estimates that are fully stationary and exhibit no duality gaps. As a result, the effective response and field statistics of the nonlinear composite can be estimated directly from the appropriately optimized linear comparison composite. By way of illustration, the method is applied to a porous, isotropic, power-law material, and the results are found to compare favorably with earlier bounds and estimates. However, the basic ideas of the method are expected to work for broad classes of composites materials, whose effective response can be given appropriate variational representations, including more general elasto-plastic and soft hyperelastic composites and polycrystals.
-
Bjorgaard, J. A.; Velizhanin, K. A.; Tretiak, S.
2015-08-06
This study describes variational energy expressions and analytical excited state energy gradients for time-dependent self-consistent field methods with polarizable solvent effects. Linear response, vertical excitation, and state-specific solventmodels are examined. Enforcing a variational ground stateenergy expression in the state-specific model is found to reduce it to the vertical excitation model. Variational excited state energy expressions are then provided for the linear response and vertical excitation models and analytical gradients are formulated. Using semiempiricalmodel chemistry, the variational expressions are verified by numerical and analytical differentiation with respect to a static external electric field. Lastly, analytical gradients are further tested by performingmore » microcanonical excited state molecular dynamics with p-nitroaniline.« less
-
Microfluidic-Based Measurement Method of Red Blood Cell Aggregation under Hematocrit Variations
2017-01-01
Red blood cell (RBC) aggregation and erythrocyte sedimentation rate (ESR) are considered to be promising biomarkers for effectively monitoring blood rheology at extremely low shear rates. In this study, a microfluidic-based measurement technique is suggested to evaluate RBC aggregation under hematocrit variations due to the continuous ESR. After the pipette tip is tightly fitted into an inlet port, a disposable suction pump is connected to the outlet port through a polyethylene tube. After dropping blood (approximately 0.2 mL) into the pipette tip, the blood flow can be started and stopped by periodically operating a pinch valve. To evaluate variations in RBC aggregation due to the continuous ESR, an EAI (Erythrocyte-sedimentation-rate Aggregation Index) is newly suggested, which uses temporal variations of image intensity. To demonstrate the proposed method, the dynamic characterization of the disposable suction pump is first quantitatively measured by varying the hematocrit levels and cavity volume of the suction pump. Next, variations in RBC aggregation and ESR are quantified by varying the hematocrit levels. The conventional aggregation index (AI) is maintained constant, unrelated to the hematocrit values. However, the EAI significantly decreased with respect to the hematocrit values. Thus, the EAI is more effective than the AI for monitoring variations in RBC aggregation due to the ESR. Lastly, the proposed method is employed to detect aggregated blood and thermally-induced blood. The EAI gradually increased as the concentration of a dextran solution increased. In addition, the EAI significantly decreased for thermally-induced blood. From this experimental demonstration, the proposed method is able to effectively measure variations in RBC aggregation due to continuous hematocrit variations, especially by quantifying the EAI. PMID:28878199
-
Pramudya, Ragita C; Seo, Han-Seok
2018-03-01
Temperatures of most hot or cold meal items change over the period of consumption, possibly influencing sensory perception of those items. Unlike temporal variations in sensory attributes, product temperature-induced variations have not received much attention. Using a Check-All-That-Apply (CATA) method, this study aimed to characterize variations in sensory attributes over a wide range of temperatures at which hot or cold foods and beverages may be consumed. Cooked milled rice, typically consumed at temperatures between 70 and 30°C in many rice-eating countries, was used as a target sample in this study. Two brands of long-grain milled rice were cooked and randomly presented at 70, 60, 50, 40, and 30°C. Thirty-five CATA terms for cooked milled rice were generated. Eighty-eight untrained panelists were asked to quickly select all the CATA terms that they considered appropriate to characterize sensory attributes of cooked rice samples presented at each temperature. Proportions of selection by panelists for 13 attributes significantly differed among the five temperature conditions. "Product temperature-dependent sensory-attribute variations" differed with two brands of milled rice grains. Such variations in sensory attributes, resulted from both product temperature and rice brand, were more pronounced among panelists who more frequently consumed rice. In conclusion, the CATA method can be useful for characterizing "product temperature-dependent sensory attribute variations" in cooked milled-rice samples. Further study is needed to examine whether the CATA method is also effective in capturing "product temperature-dependent sensory-attribute variations" in other hot or cold foods and beverages. Published by Elsevier Ltd.
-
An historical survey of computational methods in optimal control.
NASA Technical Reports Server (NTRS)
Polak, E.
1973-01-01
Review of some of the salient theoretical developments in the specific area of optimal control algorithms. The first algorithms for optimal control were aimed at unconstrained problems and were derived by using first- and second-variation methods of the calculus of variations. These methods have subsequently been recognized as gradient, Newton-Raphson, or Gauss-Newton methods in function space. A much more recent addition to the arsenal of unconstrained optimal control algorithms are several variations of conjugate-gradient methods. At first, constrained optimal control problems could only be solved by exterior penalty function methods. Later algorithms specifically designed for constrained problems have appeared. Among these are methods for solving the unconstrained linear quadratic regulator problem, as well as certain constrained minimum-time and minimum-energy problems. Differential-dynamic programming was developed from dynamic programming considerations. The conditional-gradient method, the gradient-projection method, and a couple of feasible directions methods were obtained as extensions or adaptations of related algorithms for finite-dimensional problems. Finally, the so-called epsilon-methods combine the Ritz method with penalty function techniques.
-
Techniques of orbital decay and long-term ephemeris prediction for satellites in earth orbit
NASA Technical Reports Server (NTRS)
Barry, B. F.; Pimm, R. S.; Rowe, C. K.
1971-01-01
In the special perturbation method, Cowell and variation-of-parameters formulations of the motion equations are implemented and numerically integrated. Variations in the orbital elements due to drag are computed using the 1970 Jacchia atmospheric density model, which includes the effects of semiannual variations, diurnal bulge, solar activity, and geomagnetic activity. In the general perturbation method, two-variable asymptotic series and automated manipulation capabilities are used to obtain analytical solutions to the variation-of-parameters equations. Solutions are obtained considering the effect of oblateness only and the combined effects of oblateness and drag. These solutions are then numerically evaluated by means of a FORTRAN program in which an updating scheme is used to maintain accurate epoch values of the elements. The atmospheric density function is approximated by a Fourier series in true anomaly, and the 1970 Jacchia model is used to periodically update the Fourier coefficients. The accuracy of both methods is demonstrated by comparing computed orbital elements to actual elements over time spans of up to 8 days for the special perturbation method and up to 356 days for the general perturbation method.
-
Dueck, Hannah; Eberwine, James; Kim, Junhyong
2016-02-01
There is a growing appreciation of the extent of transcriptome variation across individual cells of the same cell type. While expression variation may be a byproduct of, for example, dynamic or homeostatic processes, here we consider whether single-cell molecular variation per se might be crucial for population-level function. Under this hypothesis, molecular variation indicates a diversity of hidden functional capacities within an ensemble of identical cells, and this functional diversity facilitates collective behavior that would be inaccessible to a homogenous population. In reviewing this topic, we explore possible functions that might be carried by a heterogeneous ensemble of cells; however, this question has proven difficult to test, both because methods to manipulate molecular variation are limited and because it is complicated to define, and measure, population-level function. We consider several possible methods to further pursue the hypothesis that variation is function through the use of comparative analysis and novel experimental techniques. © 2015 The Authors. BioEssays published by WILEY Periodicals, Inc.
-
Yu, Hui; Qi, Dan; Li, Heng-da; Xu, Ke-xin; Yuan, Wei-jie
2012-03-01
Weak signal, low instrument signal-to-noise ratio, continuous variation of human physiological environment and the interferences from other components in blood make it difficult to extract the blood glucose information from near infrared spectrum in noninvasive blood glucose measurement. The floating-reference method, which analyses the effect of glucose concentration variation on absorption coefficient and scattering coefficient, gets spectrum at the reference point and the measurement point where the light intensity variations from absorption and scattering are counteractive and biggest respectively. By using the spectrum from reference point as reference, floating-reference method can reduce the interferences from variation of physiological environment and experiment circumstance. In the present paper, the effectiveness of floating-reference method working on improving prediction precision and stability was assessed through application experiments. The comparison was made between models whose data were processed with and without floating-reference method. The results showed that the root mean square error of prediction (RMSEP) decreased by 34.7% maximally. The floating-reference method could reduce the influences of changes of samples' state, instrument noises and drift, and improve the models' prediction precision and stability effectively.
-
A comparison of five methods for monitoring the precision of automated x-ray film processors.
Nickoloff, E L; Leo, F; Reese, M
1978-11-01
Five different methods for preparing sensitometric strips used to monitor the precision of automated film processors are compared. A method for determining the sensitivity of each system to processor variations is presented; the observed statistical variability is multiplied by the system response to temperature or chemical changes. Pre-exposed sensitometric strips required the use of accurate densitometers and stringent control limits to be effective. X-ray exposed sensitometric strips demonstrated large variations in the x-ray output (2 omega approximately equal to 8.0%) over a period of one month. Some light sensitometers were capable of detecting +/- 1.0 degrees F (+/- 0.6 degrees C) variations in developer temperature in the processor and/or about 10.0 ml of chemical contamination in the processor. Nevertheless, even the light sensitometers were susceptible to problems, e.g. film emulsion selection, line voltage variations, and latent image fading. Advantages and disadvantages of the various sensitometric methods are discussed.
-
The variational method in quantum mechanics: an elementary introduction
NASA Astrophysics Data System (ADS)
Borghi, Riccardo
2018-05-01
Variational methods in quantum mechanics are customarily presented as invaluable techniques to find approximate estimates of ground state energies. In the present paper a short catalogue of different celebrated potential distributions (both 1D and 3D), for which an exact and complete (energy and wavefunction) ground state determination can be achieved in an elementary way, is illustrated. No previous knowledge of calculus of variations is required. Rather, in all presented cases the exact energy functional minimization is achieved by using only a couple of simple mathematical tricks: ‘completion of square’ and integration by parts. This makes our approach particularly suitable for undergraduates. Moreover, the key role played by particle localization is emphasized through the entire analysis. This gentle introduction to the variational method could also be potentially attractive for more expert students as a possible elementary route toward a rather advanced topic on quantum mechanics: the factorization method. Such an unexpected connection is outlined in the final part of the paper.
-
Multigrid Solution of the Navier-Stokes Equations at Low Speeds with Large Temperature Variations
NASA Technical Reports Server (NTRS)
Sockol, Peter M.
2002-01-01
Multigrid methods for the Navier-Stokes equations at low speeds and large temperature variations are investigated. The compressible equations with time-derivative preconditioning and preconditioned flux-difference splitting of the inviscid terms are used. Three implicit smoothers have been incorporated into a common multigrid procedure. Both full coarsening and semi-coarsening with directional fine-grid defect correction have been studied. The resulting methods have been tested on four 2D laminar problems over a range of Reynolds numbers on both uniform and highly stretched grids. Two of the three methods show efficient and robust performance over the entire range of conditions. In addition none of the methods have any difficulty with the large temperature variations.
-
Willingness and ability to pay for artemisinin-based combination therapy in rural Tanzania.
Saulo, Eleonor C; Forsberg, Birger C; Premji, Zul; Montgomery, Scott M; Björkman, Anders
2008-10-31
The aim of this study was to analyse willingness to pay (WTP) and ability to pay (ATP) for ACT for children below five years of age in a rural setting in Tanzania before the introduction of artemisinin-based combination therapy (ACT) as first-line treatment for uncomplicated malaria. Socio-economic factors associated with WTP and expectations on anti-malaria drugs, including ACT, were also explored. Structured interviews and focus group discussions were held with mothers, household heads, health-care workers and village leaders in Ishozi, Gera and Ishunju wards in north-west Tanzania in 2004. Contingent valuation method (CVM) was used with "take-it-or-leave-it" as the eliciting method, expressed as WTP for a full course of ACT for a child and households' opportunity cost of ACT was used to assess ATP. The study included descriptive analyses with multivariate adjustment for potential confounding factors. Among 265 mothers and household heads, 244 (92%, CI = 88%-95%) were willing to pay Tanzanian Shillings (TSh) 500 (US$ 0.46) for a child's dose of ACT, but only 55% (49%-61%) were willing to pay more than TSh 500. Mothers were more often willing to pay than male household heads (adjusted odds ratio = 2.1, CI = 1.2-3.6). Socio-economic status had no significant effect on WTP. The median annual non-subsidized ACT cost for clinical malaria episodes in an average household was calculated as US$ 6.0, which would represent 0.9% of the average total consumption expenditures as estimated from official data in 2001. The cost of non-subsidized ACT represented 7.0% of reported total annual expenditure on food and 33.0% of total annual expenditure on health care."Rapid effect," "no adverse effect" and "inexpensive" were the most desired features of an anti-malarial drug. WTP for ACT in this study was less than its real cost and a subsidy is, therefore, needed to enable its equitable affordability. The decision taken in Tanzania to subsidize Coartem fully at governmental health care facilities and at a consumer price of TSh 300-500 (US$ 0.28-0.46) at special designated shops through the programme of Accredited Drug Dispensing Outlets (ADDOs) appears to be well founded.
-
Zhang, Hanming; Wang, Linyuan; Yan, Bin; Li, Lei; Cai, Ailong; Hu, Guoen
2016-01-01
Total generalized variation (TGV)-based computed tomography (CT) image reconstruction, which utilizes high-order image derivatives, is superior to total variation-based methods in terms of the preservation of edge information and the suppression of unfavorable staircase effects. However, conventional TGV regularization employs l1-based form, which is not the most direct method for maximizing sparsity prior. In this study, we propose a total generalized p-variation (TGpV) regularization model to improve the sparsity exploitation of TGV and offer efficient solutions to few-view CT image reconstruction problems. To solve the nonconvex optimization problem of the TGpV minimization model, we then present an efficient iterative algorithm based on the alternating minimization of augmented Lagrangian function. All of the resulting subproblems decoupled by variable splitting admit explicit solutions by applying alternating minimization method and generalized p-shrinkage mapping. In addition, approximate solutions that can be easily performed and quickly calculated through fast Fourier transform are derived using the proximal point method to reduce the cost of inner subproblems. The accuracy and efficiency of the simulated and real data are qualitatively and quantitatively evaluated to validate the efficiency and feasibility of the proposed method. Overall, the proposed method exhibits reasonable performance and outperforms the original TGV-based method when applied to few-view problems.
-
Li, Xingyu; Plataniotis, Konstantinos N
2015-07-01
In digital histopathology, tasks of segmentation and disease diagnosis are achieved by quantitative analysis of image content. However, color variation in image samples makes it challenging to produce reliable results. This paper introduces a complete normalization scheme to address the problem of color variation in histopathology images jointly caused by inconsistent biopsy staining and nonstandard imaging condition. Method : Different from existing normalization methods that either address partial cause of color variation or lump them together, our method identifies causes of color variation based on a microscopic imaging model and addresses inconsistency in biopsy imaging and staining by an illuminant normalization module and a spectral normalization module, respectively. In evaluation, we use two public datasets that are representative of histopathology images commonly received in clinics to examine the proposed method from the aspects of robustness to system settings, performance consistency against achromatic pixels, and normalization effectiveness in terms of histological information preservation. As the saturation-weighted statistics proposed in this study generates stable and reliable color cues for stain normalization, our scheme is robust to system parameters and insensitive to image content and achromatic colors. Extensive experimentation suggests that our approach outperforms state-of-the-art normalization methods as the proposed method is the only approach that succeeds to preserve histological information after normalization. The proposed color normalization solution would be useful to mitigate effects of color variation in pathology images on subsequent quantitative analysis.
-
Laplace transform homotopy perturbation method for the approximation of variational problems.
Filobello-Nino, U; Vazquez-Leal, H; Rashidi, M M; Sedighi, H M; Perez-Sesma, A; Sandoval-Hernandez, M; Sarmiento-Reyes, A; Contreras-Hernandez, A D; Pereyra-Diaz, D; Hoyos-Reyes, C; Jimenez-Fernandez, V M; Huerta-Chua, J; Castro-Gonzalez, F; Laguna-Camacho, J R
2016-01-01
This article proposes the application of Laplace Transform-Homotopy Perturbation Method and some of its modifications in order to find analytical approximate solutions for the linear and nonlinear differential equations which arise from some variational problems. As case study we will solve four ordinary differential equations, and we will show that the proposed solutions have good accuracy, even we will obtain an exact solution. In the sequel, we will see that the square residual error for the approximate solutions, belongs to the interval [0.001918936920, 0.06334882582], which confirms the accuracy of the proposed methods, taking into account the complexity and difficulty of variational problems.
-
Compensation of flare-induced CD changes EUVL
Bjorkholm, John E [Pleasanton, CA; Stearns, Daniel G [Los Altos, CA; Gullikson, Eric M [Oakland, CA; Tichenor, Daniel A [Castro Valley, CA; Hector, Scott D [Oakland, CA
2004-11-09
A method for compensating for flare-induced critical dimensions (CD) changes in photolithography. Changes in the flare level results in undesirable CD changes. The method when used in extreme ultraviolet (EUV) lithography essentially eliminates the unwanted CD changes. The method is based on the recognition that the intrinsic level of flare for an EUV camera (the flare level for an isolated sub-resolution opaque dot in a bright field mask) is essentially constant over the image field. The method involves calculating the flare and its variation over the area of a patterned mask that will be imaged and then using mask biasing to largely eliminate the CD variations that the flare and its variations would otherwise cause. This method would be difficult to apply to optical or DUV lithography since the intrinsic flare for those lithographies is not constant over the image field.
-
Yu, Tao; Chan, Kannie W Y; Anonuevo, Abraham; Song, Xiaolei; Schuster, Benjamin S; Chattopadhyay, Sumon; Xu, Qingguo; Oskolkov, Nikita; Patel, Himatkumar; Ensign, Laura M; van Zjil, Peter C M; McMahon, Michael T; Hanes, Justin
2015-02-01
Mucus barriers lining mucosal epithelia reduce the effectiveness of nanocarrier-based mucosal drug delivery and imaging ("theranostics"). Here, we describe liposome-based mucus-penetrating particles (MPP) capable of loading hydrophilic agents, e.g., the diaCEST MRI contrast agent barbituric acid (BA). We observed that polyethylene glycol (PEG)-coated liposomes containing ≥7 mol% PEG diffused only ~10-fold slower in human cervicovaginal mucus (CVM) compared to their theoretical speeds in water. 7 mol%-PEG liposomes contained sufficient BA loading for diaCEST contrast, and provided improved vaginal distribution compared to 0 and 3mol%-PEG liposomes. However, increasing PEG content to ~12 mol% compromised BA loading and vaginal distribution, suggesting that PEG content must be optimized to maintain drug loading and stability. Non-invasive diaCEST MRI illustrated uniform vaginal coverage and longer retention of BA-loaded 7 mol%-PEG liposomes compared to unencapsulated BA. Liposomal MPP with optimized PEG content hold promise for drug delivery and imaging at mucosal surfaces. This team of authors characterized liposome-based mucus-penetrating particles (MPP) capable of loading hydrophilic agents, such as barbituric acid (a diaCEST MRI contrast agent) and concluded that liposomal MPP with optimized PEG coating enables drug delivery and imaging at mucosal surfaces. Copyright © 2015 Elsevier Inc. All rights reserved.
-
Applications of He's semi-inverse method, ITEM and GGM to the Davey-Stewartson equation
NASA Astrophysics Data System (ADS)
Zinati, Reza Farshbaf; Manafian, Jalil
2017-04-01
We investigate the Davey-Stewartson (DS) equation. Travelling wave solutions were found. In this paper, we demonstrate the effectiveness of the analytical methods, namely, He's semi-inverse variational principle method (SIVPM), the improved tan(φ/2)-expansion method (ITEM) and generalized G'/G-expansion method (GGM) for seeking more exact solutions via the DS equation. These methods are direct, concise and simple to implement compared to other existing methods. The exact solutions containing four types solutions have been achieved. The results demonstrate that the aforementioned methods are more efficient than the Ansatz method applied by Mirzazadeh (2015). Abundant exact travelling wave solutions including solitons, kink, periodic and rational solutions have been found by the improved tan(φ/2)-expansion and generalized G'/G-expansion methods. By He's semi-inverse variational principle we have obtained dark and bright soliton wave solutions. Also, the obtained semi-inverse variational principle has profound implications in physical understandings. These solutions might play important role in engineering and physics fields. Moreover, by using Matlab, some graphical simulations were done to see the behavior of these solutions.
-
2010-01-01
Intense interest centers on the role of the human gut microbiome in health and disease, but optimal methods for analysis are still under development. Here we present a study of methods for surveying bacterial communities in human feces using 454/Roche pyrosequencing of 16S rRNA gene tags. We analyzed fecal samples from 10 individuals and compared methods for storage, DNA purification and sequence acquisition. To assess reproducibility, we compared samples one cm apart on a single stool specimen for each individual. To analyze storage methods, we compared 1) immediate freezing at -80°C, 2) storage on ice for 24 or 3) 48 hours. For DNA purification methods, we tested three commercial kits and bead beating in hot phenol. Variations due to the different methodologies were compared to variation among individuals using two approaches--one based on presence-absence information for bacterial taxa (unweighted UniFrac) and the other taking into account their relative abundance (weighted UniFrac). In the unweighted analysis relatively little variation was associated with the different analytical procedures, and variation between individuals predominated. In the weighted analysis considerable variation was associated with the purification methods. Particularly notable was improved recovery of Firmicutes sequences using the hot phenol method. We also carried out surveys of the effects of different 454 sequencing methods (FLX versus Titanium) and amplification of different 16S rRNA variable gene segments. Based on our findings we present recommendations for protocols to collect, process and sequence bacterial 16S rDNA from fecal samples--some major points are 1) if feasible, bead-beating in hot phenol or use of the PSP kit improves recovery; 2) storage methods can be adjusted based on experimental convenience; 3) unweighted (presence-absence) comparisons are less affected by lysis method. PMID:20673359
-
Numerical realization of the variational method for generating self-trapped beams
NASA Astrophysics Data System (ADS)
Duque, Erick I.; Lopez-Aguayo, Servando; Malomed, Boris A.
2018-03-01
We introduce a numerical variational method based on the Rayleigh-Ritz optimization principle for predicting two-dimensional self-trapped beams in nonlinear media. This technique overcomes the limitation of the traditional variational approximation in performing analytical Lagrangian integration and differentiation. Approximate soliton solutions of a generalized nonlinear Schr\\"odinger equation are obtained, demonstrating robustness of the beams of various types (fundamental, vortices, multipoles, azimuthons) in the course of their propagation. The algorithm offers possibilities to produce more sophisticated soliton profiles in general nonlinear models.
-
NASA Astrophysics Data System (ADS)
Longuevergne, Laurent; Scanlon, Bridget R.; Wilson, Clark R.
2010-11-01
The Gravity Recovery and Climate Experiment (GRACE) satellites provide observations of water storage variation at regional scales. However, when focusing on a region of interest, limited spatial resolution and noise contamination can cause estimation bias and spatial leakage, problems that are exacerbated as the region of interest approaches the GRACE resolution limit of a few hundred km. Reliable estimates of water storage variations in small basins require compromises between competing needs for noise suppression and spatial resolution. The objective of this study was to quantitatively investigate processing methods and their impacts on bias, leakage, GRACE noise reduction, and estimated total error, allowing solution of the trade-offs. Among the methods tested is a recently developed concentration algorithm called spatiospectral localization, which optimizes the basin shape description, taking into account limited spatial resolution. This method is particularly suited to retrieval of basin-scale water storage variations and is effective for small basins. To increase confidence in derived methods, water storage variations were calculated for both CSR (Center for Space Research) and GRGS (Groupe de Recherche de Géodésie Spatiale) GRACE products, which employ different processing strategies. The processing techniques were tested on the intensively monitored High Plains Aquifer (450,000 km2 area), where application of the appropriate optimal processing method allowed retrieval of water storage variations over a portion of the aquifer as small as ˜200,000 km2.
-
Hooper, Lisa M.; Weinfurt, Kevin P.; Cooper, Lisa A.; Mensh, Julie; Harless, William; Kuhajda, Melissa C.; Epstein, Steven A.
2009-01-01
Background Some primary care physicians provide less than optimal care for depression (Kessler et al., Journal of the American Medical Association 291, 2581–90, 2004). However, the literature is not unanimous on the best method to use in order to investigate this variation in care. To capture variations in physician behaviour and decision making in primary care settings, 32 interactive CD-ROM vignettes were constructed and tested. Aim and method The primary aim of this methods-focused paper was to review the extent to which our study method – an interactive CD-ROM patient vignette methodology – was effective in capturing variation in physician behaviour. Specifically, we examined the following questions: (a) Did the interactive CD-ROM technology work? (b) Did we create believable virtual patients? (c) Did the research protocol enable interviews (data collection) to be completed as planned? (d) To what extent was the targeted study sample size achieved? and (e) Did the study interview protocol generate valid and reliable quantitative data and rich, credible qualitative data? Findings Among a sample of 404 randomly selected primary care physicians, our voice-activated interactive methodology appeared to be effective. Specifically, our methodology – combining interactive virtual patient vignette technology, experimental design, and expansive open-ended interview protocol – generated valid explanations for variations in primary care physician practice patterns related to depression care. PMID:20463864
-
A tri-modality image fusion method for target delineation of brain tumors in radiotherapy.
Guo, Lu; Shen, Shuming; Harris, Eleanor; Wang, Zheng; Jiang, Wei; Guo, Yu; Feng, Yuanming
2014-01-01
To develop a tri-modality image fusion method for better target delineation in image-guided radiotherapy for patients with brain tumors. A new method of tri-modality image fusion was developed, which can fuse and display all image sets in one panel and one operation. And a feasibility study in gross tumor volume (GTV) delineation using data from three patients with brain tumors was conducted, which included images of simulation CT, MRI, and 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) examinations before radiotherapy. Tri-modality image fusion was implemented after image registrations of CT+PET and CT+MRI, and the transparency weight of each modality could be adjusted and set by users. Three radiation oncologists delineated GTVs for all patients using dual-modality (MRI/CT) and tri-modality (MRI/CT/PET) image fusion respectively. Inter-observer variation was assessed by the coefficient of variation (COV), the average distance between surface and centroid (ADSC), and the local standard deviation (SDlocal). Analysis of COV was also performed to evaluate intra-observer volume variation. The inter-observer variation analysis showed that, the mean COV was 0.14(± 0.09) and 0.07(± 0.01) for dual-modality and tri-modality respectively; the standard deviation of ADSC was significantly reduced (p<0.05) with tri-modality; SDlocal averaged over median GTV surface was reduced in patient 2 (from 0.57 cm to 0.39 cm) and patient 3 (from 0.42 cm to 0.36 cm) with the new method. The intra-observer volume variation was also significantly reduced (p = 0.00) with the tri-modality method as compared with using the dual-modality method. With the new tri-modality image fusion method smaller inter- and intra-observer variation in GTV definition for the brain tumors can be achieved, which improves the consistency and accuracy for target delineation in individualized radiotherapy.
-
Hardy, A; Itzkowitz, M; Griffel, G
1989-05-15
A variational moment method is used to calculate propagation constants of 1-D optical waveguides with an arbitrary index profile. The method is applicable to 2-D waveguides as well, and the index profiles need not be symmetric. Examples are given for the lowest-order and the next higher-order modes and are compared with exact numerical solutions.
-
Some New Mathematical Methods for Variational Objective Analysis
NASA Technical Reports Server (NTRS)
Wahba, G.; Johnson, D. R.
1984-01-01
New and/or improved variational methods for simultaneously combining forecast, heterogeneous observational data, a priori climatology, and physics to obtain improved estimates of the initial state of the atmosphere for the purpose of numerical weather prediction are developed. Cross validated spline methods are applied to atmospheric data for the purpose of improved description and analysis of atmospheric phenomena such as the tropopause and frontal boundary surfaces.
-
DOE Office of Scientific and Technical Information (OSTI.GOV)
Altunbas, Cem, E-mail: caltunbas@gmail.com; Lai, Chao-Jen; Zhong, Yuncheng
Purpose: In using flat panel detectors (FPD) for cone beam computed tomography (CBCT), pixel gain variations may lead to structured nonuniformities in projections and ring artifacts in CBCT images. Such gain variations can be caused by change in detector entrance exposure levels or beam hardening, and they are not accounted by conventional flat field correction methods. In this work, the authors presented a method to identify isolated pixel clusters that exhibit gain variations and proposed a pixel gain correction (PGC) method to suppress both beam hardening and exposure level dependent gain variations. Methods: To modulate both beam spectrum and entrancemore » exposure, flood field FPD projections were acquired using beam filters with varying thicknesses. “Ideal” pixel values were estimated by performing polynomial fits in both raw and flat field corrected projections. Residuals were calculated by taking the difference between measured and ideal pixel values to identify clustered image and FPD artifacts in flat field corrected and raw images, respectively. To correct clustered image artifacts, the ratio of ideal to measured pixel values in filtered images were utilized as pixel-specific gain correction factors, referred as PGC method, and they were tabulated as a function of pixel value in a look-up table. Results: 0.035% of detector pixels lead to clustered image artifacts in flat field corrected projections, where 80% of these pixels were traced back and linked to artifacts in the FPD. The performance of PGC method was tested in variety of imaging conditions and phantoms. The PGC method reduced clustered image artifacts and fixed pattern noise in projections, and ring artifacts in CBCT images. Conclusions: Clustered projection image artifacts that lead to ring artifacts in CBCT can be better identified with our artifact detection approach. When compared to the conventional flat field correction method, the proposed PGC method enables characterization of nonlinear pixel gain variations as a function of change in x-ray spectrum and intensity. Hence, it can better suppress image artifacts due to beam hardening as well as artifacts that arise from detector entrance exposure variation.« less
-
An efficient deterministic-probabilistic approach to modeling regional groundwater flow: 1. Theory
Yen, Chung-Cheng; Guymon, Gary L.
1990-01-01
An efficient probabilistic model is developed and cascaded with a deterministic model for predicting water table elevations in regional aquifers. The objective is to quantify model uncertainty where precise estimates of water table elevations may be required. The probabilistic model is based on the two-point probability method which only requires prior knowledge of uncertain variables mean and coefficient of variation. The two-point estimate method is theoretically developed and compared with the Monte Carlo simulation method. The results of comparisons using hypothetical determinisitic problems indicate that the two-point estimate method is only generally valid for linear problems where the coefficients of variation of uncertain parameters (for example, storage coefficient and hydraulic conductivity) is small. The two-point estimate method may be applied to slightly nonlinear problems with good results, provided coefficients of variation are small. In such cases, the two-point estimate method is much more efficient than the Monte Carlo method provided the number of uncertain variables is less than eight.
-
An Efficient Deterministic-Probabilistic Approach to Modeling Regional Groundwater Flow: 1. Theory
NASA Astrophysics Data System (ADS)
Yen, Chung-Cheng; Guymon, Gary L.
1990-07-01
An efficient probabilistic model is developed and cascaded with a deterministic model for predicting water table elevations in regional aquifers. The objective is to quantify model uncertainty where precise estimates of water table elevations may be required. The probabilistic model is based on the two-point probability method which only requires prior knowledge of uncertain variables mean and coefficient of variation. The two-point estimate method is theoretically developed and compared with the Monte Carlo simulation method. The results of comparisons using hypothetical determinisitic problems indicate that the two-point estimate method is only generally valid for linear problems where the coefficients of variation of uncertain parameters (for example, storage coefficient and hydraulic conductivity) is small. The two-point estimate method may be applied to slightly nonlinear problems with good results, provided coefficients of variation are small. In such cases, the two-point estimate method is much more efficient than the Monte Carlo method provided the number of uncertain variables is less than eight.
-
A First Step towards Variational Methods in Engineering
ERIC Educational Resources Information Center
Periago, Francisco
2003-01-01
In this paper, a didactical proposal is presented to introduce the variational methods for solving boundary value problems to engineering students. Starting from a couple of simple models arising in linear elasticity and heat diffusion, the concept of weak solution for these models is motivated and the existence, uniqueness and continuous…
-
A study on Marangoni convection by the variational iteration method
NASA Astrophysics Data System (ADS)
Karaoǧlu, Onur; Oturanç, Galip
2012-09-01
In this paper, we will consider the use of the variational iteration method and Padé approximant for finding approximate solutions for a Marangoni convection induced flow over a free surface due to an imposed temperature gradient. The solutions are compared with the numerical (fourth-order Runge Kutta) solutions.
-
DOE Office of Scientific and Technical Information (OSTI.GOV)
Niu, S; Zhang, Y; Ma, J
Purpose: To investigate iterative reconstruction via prior image constrained total generalized variation (PICTGV) for spectral computed tomography (CT) using fewer projections while achieving greater image quality. Methods: The proposed PICTGV method is formulated as an optimization problem, which balances the data fidelity and prior image constrained total generalized variation of reconstructed images in one framework. The PICTGV method is based on structure correlations among images in the energy domain and high-quality images to guide the reconstruction of energy-specific images. In PICTGV method, the high-quality image is reconstructed from all detector-collected X-ray signals and is referred as the broad-spectrum image. Distinctmore » from the existing reconstruction methods applied on the images with first order derivative, the higher order derivative of the images is incorporated into the PICTGV method. An alternating optimization algorithm is used to minimize the PICTGV objective function. We evaluate the performance of PICTGV on noise and artifacts suppressing using phantom studies and compare the method with the conventional filtered back-projection method as well as TGV based method without prior image. Results: On the digital phantom, the proposed method outperforms the existing TGV method in terms of the noise reduction, artifacts suppression, and edge detail preservation. Compared to that obtained by the TGV based method without prior image, the relative root mean square error in the images reconstructed by the proposed method is reduced by over 20%. Conclusion: The authors propose an iterative reconstruction via prior image constrained total generalize variation for spectral CT. Also, we have developed an alternating optimization algorithm and numerically demonstrated the merits of our approach. Results show that the proposed PICTGV method outperforms the TGV method for spectral CT.« less
-
NASA Astrophysics Data System (ADS)
Verechagin, V.; Kris, R.; Schwarzband, I.; Milstein, A.; Cohen, B.; Shkalim, A.; Levy, S.; Price, D.; Bal, E.
2018-03-01
Over the years, mask and wafers defects dispositioning has become an increasingly challenging and time consuming task. With design rules getting smaller, OPC getting complex and scanner illumination taking on free-form shapes - the probability of a user to perform accurate and repeatable classification of defects detected by mask inspection tools into pass/fail bins is reducing. The critical challenging of mask defect metrology for small nodes ( < 30 nm) was reviewed in [1]. While Critical Dimension (CD) variation measurement is still the method of choice for determining a mask defect future impact on wafer, the high complexity of OPCs combined with high variability in pattern shapes poses a challenge for any automated CD variation measurement method. In this study, a novel approach for measurement generalization is presented. CD variation assessment performance is evaluated on multiple different complex shape patterns, and is benchmarked against an existing qualified measurement methodology.
-
A New Evaluation Method of Stored Heat Effect of Reinforced Concrete Wall of Cold Storage
NASA Astrophysics Data System (ADS)
Nomura, Tomohiro; Murakami, Yuji; Uchikawa, Motoyuki
Today it has become imperative to save energy by operating a refrigerator in a cold storage executed by external insulate reinforced concrete wall intermittently. The theme of the paper is to get the evaluation method to be capable of calculating, numerically, interval time for stopping the refrigerator, in applying reinforced concrete wall as source of stored heat. The experiments with the concrete models were performed in order to examine the time variation of internal temperature after refrigerator stopped. In addition, the simulation method with three dimensional unsteady FEM for personal-computer type was introduced for easily analyzing the internal temperature variation. Using this method, it is possible to obtain the time variation of internal temperature and to calculate the interval time for stopping the refrigerator.
-
Application of the moving frame method to deformed Willmore surfaces in space forms
NASA Astrophysics Data System (ADS)
Paragoda, Thanuja
2018-06-01
The main goal of this paper is to use the theory of exterior differential forms in deriving variations of the deformed Willmore energy in space forms and study the minimizers of the deformed Willmore energy in space forms. We derive both first and second order variations of deformed Willmore energy in space forms explicitly using moving frame method. We prove that the second order variation of deformed Willmore energy depends on the intrinsic Laplace Beltrami operator, the sectional curvature and some special operators along with mean and Gauss curvatures of the surface embedded in space forms, while the first order variation depends on the extrinsic Laplace Beltrami operator.
-
Farno, E; Coventry, K; Slatter, P; Eshtiaghi, N
2018-06-15
Sludge pumps in wastewater treatment plants are often oversized due to uncertainty in calculation of pressure drop. This issue costs millions of dollars for industry to purchase and operate the oversized pumps. Besides costs, higher electricity consumption is associated with extra CO 2 emission which creates huge environmental impacts. Calculation of pressure drop via current pipe flow theory requires model estimation of flow curve data which depends on regression analysis and also varies with natural variation of rheological data. This study investigates impact of variation of rheological data and regression analysis on variation of pressure drop calculated via current pipe flow theories. Results compare the variation of calculated pressure drop between different models and regression methods and suggest on the suitability of each method. Copyright © 2018 Elsevier Ltd. All rights reserved.
-
CNV-TV: a robust method to discover copy number variation from short sequencing reads.
Duan, Junbo; Zhang, Ji-Gang; Deng, Hong-Wen; Wang, Yu-Ping
2013-05-02
Copy number variation (CNV) is an important structural variation (SV) in human genome. Various studies have shown that CNVs are associated with complex diseases. Traditional CNV detection methods such as fluorescence in situ hybridization (FISH) and array comparative genomic hybridization (aCGH) suffer from low resolution. The next generation sequencing (NGS) technique promises a higher resolution detection of CNVs and several methods were recently proposed for realizing such a promise. However, the performances of these methods are not robust under some conditions, e.g., some of them may fail to detect CNVs of short sizes. There has been a strong demand for reliable detection of CNVs from high resolution NGS data. A novel and robust method to detect CNV from short sequencing reads is proposed in this study. The detection of CNV is modeled as a change-point detection from the read depth (RD) signal derived from the NGS, which is fitted with a total variation (TV) penalized least squares model. The performance (e.g., sensitivity and specificity) of the proposed approach are evaluated by comparison with several recently published methods on both simulated and real data from the 1000 Genomes Project. The experimental results showed that both the true positive rate and false positive rate of the proposed detection method do not change significantly for CNVs with different copy numbers and lengthes, when compared with several existing methods. Therefore, our proposed approach results in a more reliable detection of CNVs than the existing methods.
-
Constrained variation in Jastrow method at high density
DOE Office of Scientific and Technical Information (OSTI.GOV)
Owen, J.C.; Bishop, R.F.; Irvine, J.M.
1976-11-01
A method is derived for constraining the correlation function in a Jastrow variational calculation which permits the truncation of the cluster expansion after two-body terms, and which permits exact minimization of the two-body cluster by functional variation. This method is compared with one previously proposed by Pandharipande and is found to be superior both theoretically and practically. The method is tested both on liquid /sup 3/He, by using the Lennard--Jones potential, and on the model system of neutrons treated as Boltzmann particles (''homework'' problem). Good agreement is found both with experiment and with other calculations involving the explicit evaluation ofmore » higher-order terms in the cluster expansion. The method is then applied to a more realistic model of a neutron gas up to a density of 4 neutrons per F/sup 3/, and is found to give ground-state energies considerably lower than those of Pandharipande. (AIP)« less
-
A visual tracking method based on deep learning without online model updating
NASA Astrophysics Data System (ADS)
Tang, Cong; Wang, Yicheng; Feng, Yunsong; Zheng, Chao; Jin, Wei
2018-02-01
The paper proposes a visual tracking method based on deep learning without online model updating. In consideration of the advantages of deep learning in feature representation, deep model SSD (Single Shot Multibox Detector) is used as the object extractor in the tracking model. Simultaneously, the color histogram feature and HOG (Histogram of Oriented Gradient) feature are combined to select the tracking object. In the process of tracking, multi-scale object searching map is built to improve the detection performance of deep detection model and the tracking efficiency. In the experiment of eight respective tracking video sequences in the baseline dataset, compared with six state-of-the-art methods, the method in the paper has better robustness in the tracking challenging factors, such as deformation, scale variation, rotation variation, illumination variation, and background clutters, moreover, its general performance is better than other six tracking methods.
-
Adaptive variational mode decomposition method for signal processing based on mode characteristic
NASA Astrophysics Data System (ADS)
Lian, Jijian; Liu, Zhuo; Wang, Haijun; Dong, Xiaofeng
2018-07-01
Variational mode decomposition is a completely non-recursive decomposition model, where all the modes are extracted concurrently. However, the model requires a preset mode number, which limits the adaptability of the method since a large deviation in the number of mode set will cause the discard or mixing of the mode. Hence, a method called Adaptive Variational Mode Decomposition (AVMD) was proposed to automatically determine the mode number based on the characteristic of intrinsic mode function. The method was used to analyze the simulation signals and the measured signals in the hydropower plant. Comparisons have also been conducted to evaluate the performance by using VMD, EMD and EWT. It is indicated that the proposed method has strong adaptability and is robust to noise. It can determine the mode number appropriately without modulation even when the signal frequencies are relatively close.
-
Selecting Magnet Laminations Recipes Using the Meth-od of Sim-u-la-ted Annealing
NASA Astrophysics Data System (ADS)
Russell, A. D.; Baiod, R.; Brown, B. C.; Harding, D. J.; Martin, P. S.
1997-05-01
The Fermilab Main Injector project is building 344 dipoles using more than 7000 tons of steel. Budget and logistical constraints required that steel production, lamination stamping and magnet fabrication proceed in parallel. There were significant run-to-run variations in the magnetic properties of the steel (Martin, P.S., et al., Variations in the Steel Properties and the Excitation Characteristics of FMI Dipoles, this conference). The large lamination size (>0.5 m coil opening) resulted in variations of gap height due to differences in stress relief in the steel after stamping. To minimize magnet-to-magnet strength and field shape variations the laminations were shuffled based on the available magnetic and mechanical data and assigned to magnets using a computer program based on the method of simulated annealing. The lamination sets selected by the program have produced magnets which easily satisfy the design requirements. Variations of the average magnet gap are an order of magnitude smaller than the variations in lamination gaps. This paper discusses observed gap variations, the program structure and the strength uniformity results.
-
Szatkiewicz, Jin P; Wang, WeiBo; Sullivan, Patrick F; Wang, Wei; Sun, Wei
2013-02-01
Structural variation is an important class of genetic variation in mammals. High-throughput sequencing (HTS) technologies promise to revolutionize copy-number variation (CNV) detection but present substantial analytic challenges. Converging evidence suggests that multiple types of CNV-informative data (e.g. read-depth, read-pair, split-read) need be considered, and that sophisticated methods are needed for more accurate CNV detection. We observed that various sources of experimental biases in HTS confound read-depth estimation, and note that bias correction has not been adequately addressed by existing methods. We present a novel read-depth-based method, GENSENG, which uses a hidden Markov model and negative binomial regression framework to identify regions of discrete copy-number changes while simultaneously accounting for the effects of multiple confounders. Based on extensive calibration using multiple HTS data sets, we conclude that our method outperforms existing read-depth-based CNV detection algorithms. The concept of simultaneous bias correction and CNV detection can serve as a basis for combining read-depth with other types of information such as read-pair or split-read in a single analysis. A user-friendly and computationally efficient implementation of our method is freely available.
-
Use of variational methods in the determination of wind-driven ocean circulation
NASA Technical Reports Server (NTRS)
Gelos, R.; Laura, P. A. A.
1976-01-01
Simple polynomial approximations and a variational approach were used to predict wind-induced circulation in rectangular ocean basins. Stommel's and Munk's models were solved in a unified fashion by means of the proposed method. Very good agreement with exact solutions available in the literature was shown to exist. The method was then applied to more complex situations where an exact solution seems out of the question.
-
Variable Density Effects in Stochastic Lagrangian Models for Turbulent Combustion
2016-07-20
PDF methods in dealing with chemical reaction and convection are preserved irrespective of density variation. Since the density variation in a typical...combustion process may be as large as factor of seven, including variable- density effects in PDF methods is of significance. Conventionally, the...strategy of modelling variable density flows in PDF methods is similar to that used for second-moment closure models (SMCM): models are developed based on
-
2017-01-01
Mapping gene expression as a quantitative trait using whole genome-sequencing and transcriptome analysis allows to discover the functional consequences of genetic variation. We developed a novel method and ultra-fast software Findr for higly accurate causal inference between gene expression traits using cis-regulatory DNA variations as causal anchors, which improves current methods by taking into consideration hidden confounders and weak regulations. Findr outperformed existing methods on the DREAM5 Systems Genetics challenge and on the prediction of microRNA and transcription factor targets in human lymphoblastoid cells, while being nearly a million times faster. Findr is publicly available at https://github.com/lingfeiwang/findr. PMID:28821014
-
Variational Methods in Sensitivity Analysis and Optimization for Aerodynamic Applications
NASA Technical Reports Server (NTRS)
Ibrahim, A. H.; Hou, G. J.-W.; Tiwari, S. N. (Principal Investigator)
1996-01-01
Variational methods (VM) sensitivity analysis, which is the continuous alternative to the discrete sensitivity analysis, is employed to derive the costate (adjoint) equations, the transversality conditions, and the functional sensitivity derivatives. In the derivation of the sensitivity equations, the variational methods use the generalized calculus of variations, in which the variable boundary is considered as the design function. The converged solution of the state equations together with the converged solution of the costate equations are integrated along the domain boundary to uniquely determine the functional sensitivity derivatives with respect to the design function. The determination of the sensitivity derivatives of the performance index or functional entails the coupled solutions of the state and costate equations. As the stable and converged numerical solution of the costate equations with their boundary conditions are a priori unknown, numerical stability analysis is performed on both the state and costate equations. Thereafter, based on the amplification factors obtained by solving the generalized eigenvalue equations, the stability behavior of the costate equations is discussed and compared with the state (Euler) equations. The stability analysis of the costate equations suggests that the converged and stable solution of the costate equation is possible only if the computational domain of the costate equations is transformed to take into account the reverse flow nature of the costate equations. The application of the variational methods to aerodynamic shape optimization problems is demonstrated for internal flow problems at supersonic Mach number range. The study shows, that while maintaining the accuracy of the functional sensitivity derivatives within the reasonable range for engineering prediction purposes, the variational methods show a substantial gain in computational efficiency, i.e., computer time and memory, when compared with the finite difference sensitivity analysis.
-
Blazhko modulation in the infrared
NASA Astrophysics Data System (ADS)
Jurcsik, J.; Hajdu, G.; Dékány, I.; Nuspl, J.; Catelan, M.; Grebel, E. K.
2018-04-01
We present first direct evidence of modulation in the K band of Blazhko-type RR Lyrae stars that are identified by their secular modulations in the I-band data of Optical Gravitational Lensing Experiment-IV. A method has been developed to decompose the K-band light variation into two parts originating from the temperature and the radius changes using synthetic data of atmosphere-model grids. The amplitudes of the temperature and the radius variations derived from the method for non-Blazhko RRab stars are in very good agreement with the results of the Baade-Wesselink analysis of RRab stars in the M3 globular cluster confirming the applicability and correctness of the method. It has been found that the Blazhko modulation is primarily driven by the change in the temperature variation. The radius variation plays a marginal part, moreover it has an opposite sign as if the Blazhko effect was caused by the radii variations. This result reinforces the previous finding based on the Baade-Wesselink analysis of M3 (NGC 5272) RR Lyrae, that significant modulation of the radius variations can only be detected in radial-velocity measurements, which relies on spectral lines that form in the uppermost atmospheric layers. Our result gives the first insight into the energetics and dynamics of the Blazhko phenomenon, hence it puts strong constraints on its possible physical explanations.
-
FROG - Fingerprinting Genomic Variation Ontology
Bhardwaj, Anshu
2015-01-01
Genetic variations play a crucial role in differential phenotypic outcomes. Given the complexity in establishing this correlation and the enormous data available today, it is imperative to design machine-readable, efficient methods to store, label, search and analyze this data. A semantic approach, FROG: “FingeRprinting Ontology of Genomic variations” is implemented to label variation data, based on its location, function and interactions. FROG has six levels to describe the variation annotation, namely, chromosome, DNA, RNA, protein, variations and interactions. Each level is a conceptual aggregation of logically connected attributes each of which comprises of various properties for the variant. For example, in chromosome level, one of the attributes is location of variation and which has two properties, allosomes or autosomes. Another attribute is variation kind which has four properties, namely, indel, deletion, insertion, substitution. Likewise, there are 48 attributes and 278 properties to capture the variation annotation across six levels. Each property is then assigned a bit score which in turn leads to generation of a binary fingerprint based on the combination of these properties (mostly taken from existing variation ontologies). FROG is a novel and unique method designed for the purpose of labeling the entire variation data generated till date for efficient storage, search and analysis. A web-based platform is designed as a test case for users to navigate sample datasets and generate fingerprints. The platform is available at http://ab-openlab.csir.res.in/frog. PMID:26244889
-
Empirical correction for earth sensor horizon radiance variation
NASA Technical Reports Server (NTRS)
Hashmall, Joseph A.; Sedlak, Joseph; Andrews, Daniel; Luquette, Richard
1998-01-01
A major limitation on the use of infrared horizon sensors for attitude determination is the variability of the height of the infrared Earth horizon. This variation includes a climatological component and a stochastic component of approximately equal importance. The climatological component shows regular variation with season and latitude. Models based on historical measurements have been used to compensate for these systematic changes. The stochastic component is analogous to tropospheric weather. It can cause extreme, localized changes that for a period of days, overwhelm the climatological variation. An algorithm has been developed to compensate partially for the climatological variation of horizon height and at least to mitigate the stochastic variation. This method uses attitude and horizon sensor data from spacecraft to update a horizon height history as a function of latitude. For spacecraft that depend on horizon sensors for their attitudes (such as the Total Ozone Mapping Spectrometer-Earth Probe-TOMS-EP) a batch least squares attitude determination system is used. It is assumed that minimizing the average sensor residual throughout a full orbit of data results in attitudes that are nearly independent of local horizon height variations. The method depends on the additional assumption that the mean horizon height over all latitudes is approximately independent of season. Using these assumptions, the method yields the latitude dependent portion of local horizon height variations. This paper describes the algorithm used to generate an empirical horizon height. Ideally, an international horizon height database could be established that would rapidly merge data from various spacecraft to provide timely corrections that could be used by all.
-
NASA Astrophysics Data System (ADS)
Zhao, Xia; Wang, Guang-xin
2008-12-01
Synthetic aperture radar (SAR) is an active remote sensing sensor. It is a coherent imaging system, the speckle is its inherent default, which affects badly the interpretation and recognition of the SAR targets. Conventional methods of removing the speckle is studied usually in real SAR image, which reduce the edges of the images at the same time as depressing the speckle. Morever, Conventional methods lost the information about images phase. Removing the speckle and enhancing the target and edge simultaneously are still a puzzle. To suppress the spckle and enhance the targets and the edges simultaneously, a half-quadratic variational regularization method in complex SAR image is presented, which is based on the prior knowledge of the targets and the edge. Due to the non-quadratic and non- convex quality and the complexity of the cost function, a half-quadratic variational regularization variation is used to construct a new cost function,which is solved by alternate optimization. In the proposed scheme, the construction of the model, the solution of the model and the selection of the model peremeters are studied carefully. In the end, we validate the method using the real SAR data.Theoretic analysis and the experimental results illustrate the the feasibility of the proposed method. Further more, the proposed method can preserve the information about images phase.
-
Zhang, Hanming; Wang, Linyuan; Yan, Bin; Li, Lei; Cai, Ailong; Hu, Guoen
2016-01-01
Total generalized variation (TGV)-based computed tomography (CT) image reconstruction, which utilizes high-order image derivatives, is superior to total variation-based methods in terms of the preservation of edge information and the suppression of unfavorable staircase effects. However, conventional TGV regularization employs l1-based form, which is not the most direct method for maximizing sparsity prior. In this study, we propose a total generalized p-variation (TGpV) regularization model to improve the sparsity exploitation of TGV and offer efficient solutions to few-view CT image reconstruction problems. To solve the nonconvex optimization problem of the TGpV minimization model, we then present an efficient iterative algorithm based on the alternating minimization of augmented Lagrangian function. All of the resulting subproblems decoupled by variable splitting admit explicit solutions by applying alternating minimization method and generalized p-shrinkage mapping. In addition, approximate solutions that can be easily performed and quickly calculated through fast Fourier transform are derived using the proximal point method to reduce the cost of inner subproblems. The accuracy and efficiency of the simulated and real data are qualitatively and quantitatively evaluated to validate the efficiency and feasibility of the proposed method. Overall, the proposed method exhibits reasonable performance and outperforms the original TGV-based method when applied to few-view problems. PMID:26901410
-
A Calibration Method for Nanowire Biosensors to Suppress Device-to-device Variation
Ishikawa, Fumiaki N.; Curreli, Marco; Chang, Hsiao-Kang; Chen, Po-Chiang; Zhang, Rui; Cote, Richard J.; Thompson, Mark E.; Zhou, Chongwu
2009-01-01
Nanowire/nanotube biosensors have stimulated significant interest; however the inevitable device-to-device variation in the biosensor performance remains a great challenge. We have developed an analytical method to calibrate nanowire biosensor responses that can suppress the device-to-device variation in sensing response significantly. The method is based on our discovery of a strong correlation between the biosensor gate dependence (dIds/dVg) and the absolute response (absolute change in current, ΔI). In2O3 nanowire based biosensors for streptavidin detection were used as the model system. Studying the liquid gate effect and ionic concentration dependence of strepavidin sensing indicates that electrostatic interaction is the dominant mechanism for sensing response. Based on this sensing mechanism and transistor physics, a linear correlation between the absolute sensor response (ΔI) and the gate dependence (dIds/dVg) is predicted and confirmed experimentally. Using this correlation, a calibration method was developed where the absolute response is divided by dIds/dVg for each device, and the calibrated responses from different devices behaved almost identically. Compared to the common normalization method (normalization of the conductance/resistance/current by the initial value), this calibration method was proved advantageous using a conventional transistor model. The method presented here substantially suppresses device-to-device variation, allowing the use of nanosensors in large arrays. PMID:19921812
-
Variational Approach to Monte Carlo Renormalization Group
NASA Astrophysics Data System (ADS)
Wu, Yantao; Car, Roberto
2017-12-01
We present a Monte Carlo method for computing the renormalized coupling constants and the critical exponents within renormalization theory. The scheme, which derives from a variational principle, overcomes critical slowing down, by means of a bias potential that renders the coarse grained variables uncorrelated. The two-dimensional Ising model is used to illustrate the method.
-
Thermal and acid tolerant beta-xylosidases, genes encoding, related organisms, and methods
Thompson, David N [Idaho Falls, ID; Thompson, Vicki S [Idaho Falls, ID; Schaller, Kastli D [Ammon, ID; Apel, William A [Jackson, WY; Lacey, Jeffrey A [Idaho Falls, ID; Reed, David W [Idaho Falls, ID
2011-04-12
Isolated and/or purified polypeptides and nucleic acid sequences encoding polypeptides from Alicyclobacillus acidocaldarius and variations thereof are provided. Further provided are methods of at least partially degrading xylotriose and/or xylobiose using isolated and/or purified polypeptides and nucleic acid sequences encoding polypeptides from Alicyclobacillus acidocaldarius and variations thereof.
-
In this report we present examples of methods that we have used to explore associations between aquatic biotic condition and stressors in two different aquatic systems: estuaries and lakes. We review metrics and indices of biotic condition in lakes and estuaries; discuss some ph...
-
Mixed Gaussian-Impulse Noise Image Restoration Via Total Variation
2012-05-01
deblurring under impulse noise ,” J. Math. Imaging Vis., vol. 36, pp. 46–53, January 2010. [5] B. Li, Q. Liu, J. Xu, and X. Luo, “A new method for removing......Several Total Variation (TV) regularization methods have recently been proposed to address denoising under mixed Gaussian and impulse noise . While
-
On the optimal use of fictitious time in variation of parameters methods with application to BG14
NASA Technical Reports Server (NTRS)
Gottlieb, Robert G.
1991-01-01
The optimal way to use fictitious time in variation of parameter methods is presented. Setting fictitious time to zero at the end of each step is shown to cure the instability associated with some types of problems. Only some parameters are reinitialized, thereby retaining redundant information.
-
A Decision-Based Modified Total Variation Diffusion Method for Impulse Noise Removal
Zhu, Qingxin; Song, Xiuli; Tao, Jinsong
2017-01-01
Impulsive noise removal usually employs median filtering, switching median filtering, the total variation L1 method, and variants. These approaches however often introduce excessive smoothing and can result in extensive visual feature blurring and thus are suitable only for images with low density noise. A new method to remove noise is proposed in this paper to overcome this limitation, which divides pixels into different categories based on different noise characteristics. If an image is corrupted by salt-and-pepper noise, the pixels are divided into corrupted and noise-free; if the image is corrupted by random valued impulses, the pixels are divided into corrupted, noise-free, and possibly corrupted. Pixels falling into different categories are processed differently. If a pixel is corrupted, modified total variation diffusion is applied; if the pixel is possibly corrupted, weighted total variation diffusion is applied; otherwise, the pixel is left unchanged. Experimental results show that the proposed method is robust to different noise strengths and suitable for different images, with strong noise removal capability as shown by PSNR/SSIM results as well as the visual quality of restored images. PMID:28536602
-
Variation and Defect Tolerance for Nano Crossbars
NASA Astrophysics Data System (ADS)
Tunc, Cihan
With the extreme shrinking in CMOS technology, quantum effects and manufacturing issues are getting more crucial. Hence, additional shrinking in CMOS feature size seems becoming more challenging, difficult, and costly. On the other hand, emerging nanotechnology has attracted many researchers since additional scaling down has been demonstrated by manufacturing nanowires, Carbon nanotubes as well as molecular switches using bottom-up manufacturing techniques. In addition to the progress in manufacturing, developments in architecture show that emerging nanoelectronic devices will be promising for the future system designs. Using nano crossbars, which are composed of two sets of perpendicular nanowires with programmable intersections, it is possible to implement logic functions. In addition, nano crossbars present some important features as regularity, reprogrammability, and interchangeability. Combining these features, researchers have presented different effective architectures. Although bottom-up nanofabrication can greatly reduce manufacturing costs, due to low controllability in the manufacturing process, some critical issues occur. Bottom- up nanofabrication process results in high variation compared to conventional top- down lithography used in CMOS technology. In addition, an increased failure rate is expected. Variation and defect tolerance methods used for conventional CMOS technology seem inadequate for adapting to emerging nano technology because the variation and the defect rate for emerging nano technology is much more than current CMOS technology. Therefore, variations and defect tolerance methods for emerging nano technology are necessary for a successful transition. In this work, in order to tolerate variations for crossbars, we introduce a framework that is established based on reprogrammability and interchangeability features of nano crossbars. This framework is shown to be applicable for both FET-based and diode-based nano crossbars. We present a characterization testing method which requires minimal number of test vectors. We formulate the variation optimization problem using Simulated Annealing with different optimization goals. Furthermore, we extend the framework for defect tolerance. Experimental results and comparison of proposed framework with exhaustive methods confirm its effectiveness for both variation and defect tolerance.
-
Chen, X.; Ashcroft, I. A.; Wildman, R. D.; Tuck, C. J.
2015-01-01
A method using experimental nanoindentation and inverse finite-element analysis (FEA) has been developed that enables the spatial variation of material constitutive properties to be accurately determined. The method was used to measure property variation in a three-dimensional printed (3DP) polymeric material. The accuracy of the method is dependent on the applicability of the constitutive model used in the inverse FEA, hence four potential material models: viscoelastic, viscoelastic–viscoplastic, nonlinear viscoelastic and nonlinear viscoelastic–viscoplastic were evaluated, with the latter enabling the best fit to experimental data. Significant changes in material properties were seen in the depth direction of the 3DP sample, which could be linked to the degree of cross-linking within the material, a feature inherent in a UV-cured layer-by-layer construction method. It is proposed that the method is a powerful tool in the analysis of manufacturing processes with potential spatial property variation that will also enable the accurate prediction of final manufactured part performance. PMID:26730216
-
Chen, X; Ashcroft, I A; Wildman, R D; Tuck, C J
2015-11-08
A method using experimental nanoindentation and inverse finite-element analysis (FEA) has been developed that enables the spatial variation of material constitutive properties to be accurately determined. The method was used to measure property variation in a three-dimensional printed (3DP) polymeric material. The accuracy of the method is dependent on the applicability of the constitutive model used in the inverse FEA, hence four potential material models: viscoelastic, viscoelastic-viscoplastic, nonlinear viscoelastic and nonlinear viscoelastic-viscoplastic were evaluated, with the latter enabling the best fit to experimental data. Significant changes in material properties were seen in the depth direction of the 3DP sample, which could be linked to the degree of cross-linking within the material, a feature inherent in a UV-cured layer-by-layer construction method. It is proposed that the method is a powerful tool in the analysis of manufacturing processes with potential spatial property variation that will also enable the accurate prediction of final manufactured part performance.
-
Variational method of determining effective moduli of polycrystals with tetragonal symmetry
Meister, R.; Peselnick, L.
1966-01-01
Variational principles have been applied to aggregates of randomly oriented pure-phase polycrystals having tetragonal symmetry. The bounds of the effective elastic moduli obtained in this way show a substantial improvement over the bounds obtained by means of the Voigt and Reuss assumptions. The Hill average is found to be a good approximation in most cases when compared to the bounds found from the variational method. The new bounds reduce in their limits to the Voigt and Reuss values. ?? 1966 The American Institute of Physics.
-
Numerical realization of the variational method for generating self-trapped beams.
Duque, Erick I; Lopez-Aguayo, Servando; Malomed, Boris A
2018-03-19
We introduce a numerical variational method based on the Rayleigh-Ritz optimization principle for predicting two-dimensional self-trapped beams in nonlinear media. This technique overcomes the limitation of the traditional variational approximation in performing analytical Lagrangian integration and differentiation. Approximate soliton solutions of a generalized nonlinear Schrödinger equation are obtained, demonstrating robustness of the beams of various types (fundamental, vortices, multipoles, azimuthons) in the course of their propagation. The algorithm offers possibilities to produce more sophisticated soliton profiles in general nonlinear models.
-
NASA Technical Reports Server (NTRS)
Delamorena, B. A.
1984-01-01
A method to detect stratospheric warmings using ionospheric absorption records obtained by an Absorption Meter (method A3) is introduced. The activity of the stratospheric circulation and the D region ionospheric absorption as well as other atmospheric parameters during the winter anomaly experience an abnormal variation. A simultaneity was found in the beginning of abnormal variation in the mentioned parameters, using the absorption records for detecting the initiation of the stratospheric warming. Results of this scientific experience of forecasting in the El Arenosillo Range, are presented.
-
Ucar, Fatma; Erden, Gonul; Ginis, Zeynep; Ozturk, Gulfer; Sezer, Sevilay; Gurler, Mukaddes; Guneyk, Ahmet
2013-10-01
Available data on biological variation of HbA1c revealed marked heterogeneity. We therefore investigated and estimated the components of biological variation for HbA1c in a group of healthy individuals by applying a recommended and strictly designed study protocol using two different assay methods. Each month, samples were derived on the same day, for three months. Four EDTA whole blood samples were collected from each individual (20 women, 9 men; 20-45 years of age) and stored at -80°C until analysis. HbA1c values were measured by both high performance liquid chromatography (HPLC) (Shimadzu, Prominence, Japan) and boronate affinity chromatography methods (Trinity Biotech, Premier Hb9210, Ireland). All samples were assayed in duplicate in a single batch for each assay method. Estimations were calculated according to the formulas described by Fraser and Harris. The within subject (CV(I))-between subject (CV(G)) biological variations were 1.17% and 5.58%, respectively for HPLC. The calculated CV(I) and CV(G) were 2.15% and 4.03%, respectively for boronate affinity chromatography. Reference change value (RCV) for HPLC and boronate affinity chromatography was 5.4% and 10.4% respectively and individuality index of HbA(1c) was 0.35 and 0.93 respectively. This study for the first time described the components of biological variation for HbA1c in healthy individuals by two different assay methods. Obtained findings showed that the difference between CV(A) values of the methods might considerably affect RCV. These data regarding biological variation of HbA(1c) could be useful for a better evaluation of HbA(1c) test results in clinical interpretation. Copyright © 2013 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.
-
DOE Office of Scientific and Technical Information (OSTI.GOV)
Stemkens, B; Glitzner, M; Kontaxis, C
Purpose: To assess the dose deposition in simulated single-fraction MR-Linac treatments of renal cell carcinoma, when inter-cycle respiratory motion variation is taken into account using online MRI. Methods: Three motion characterization methods, with increasing complexity, were compared to evaluate the effect of inter-cycle motion variation and drifts on the accumulated dose for an SBRT kidney MR-Linac treatment: 1) STATIC, in which static anatomy was assumed, 2) AVG-RESP, in which 4D-MRI phase-volumes were time-weighted, based on the respiratory phase and 3) PCA, in which 3D volumes were generated using a PCA-model, enabling the detection of inter-cycle variations and drifts. An experimentalmore » ITV-based kidney treatment was simulated in a 1.5T magnetic field on three volunteer datasets. For each volunteer a retrospectively sorted 4D-MRI (ten respiratory phases) and fast 2D cine-MR images (temporal resolution = 476ms) were acquired to simulate MR-imaging during radiation. For each method, the high spatio-temporal resolution 3D volumes were non-rigidly registered to obtain deformation vector fields (DVFs). Using the DVFs, pseudo-CTs (generated from the 4D-MRI) were deformed and the dose was accumulated for the entire treatment. The accuracies of all methods were independently determined using an additional, orthogonal 2D-MRI slice. Results: Motion was most accurately estimated using the PCA method, which correctly estimated drifts and inter-cycle variations (RMSE=3.2, 2.2, 1.1mm on average for STATIC, AVG-RESP and PCA, compared to the 2DMRI slice). Dose-volume parameters on the ITV showed moderate changes (D99=35.2, 32.5, 33.8Gy for STATIC, AVG-RESP and PCA). AVG-RESP showed distinct hot/cold spots outside the ITV margin, which were more distributed for the PCA scenario, since inter-cycle variations were not modeled by the AVG-RESP method. Conclusion: Dose differences were observed when inter-cycle variations were taken into account. The increased inter-cycle randomness in motion as captured by the PCA model mitigates the local (erroneous) hotspots estimated by the AVG-RESP method.« less
-
Reddy, Michael M.; Schuster, Paul; Kendall, Carol; Reddy, Micaela B.
2006-01-01
18O is an ideal tracer for characterizing hydrological processes because it can be reliably measured in several watershed hydrological compartments. Here, we present multiyear isotopic data, i.e. 18O variations (δ18O), for precipitation inputs, surface water and groundwater in the Shingobee River Headwaters Area (SRHA), a well-instrumented research catchment in north-central Minnesota. SRHA surface waters exhibit δ18O seasonal variations similar to those of groundwaters, and seasonal δ18O variations plotted versus time fit seasonal sine functions. These seasonal δ18O variations were interpreted to estimate surface water and groundwater mean residence times (MRTs) at sampling locations near topographically closed-basin lakes. MRT variations of about 1 to 16 years have been estimated over an area covering about 9 km2 from the basin boundary to the most downgradient well. Estimated MRT error (±0·3 to ±0·7 years) is small for short MRTs and is much larger (±10 years) for a well with an MRT (16 years) near the limit of the method. Groundwater transit time estimates based on Darcy's law, tritium content, and the seasonal δ18O amplitude approach appear to be consistent within the limits of each method. The results from this study suggest that use of the δ18O seasonal variation method to determine MRTs can help assess groundwater recharge areas in small headwaters catchments.
-
Reddy, Michael M.; Schuster, Paul F.; Kendall, Carol; Reddy, Micaela B.
2006-01-01
18O is an ideal tracer for characterizing hydrological processes because it can be reliably measured in several watershed hydrological compartments. Here, we present multiyear isotopic data, i.e. 18O variations (δ18O), for precipitation inputs, surface water and groundwater in the Shingobee River Headwaters Area (SRHA), a well-instrumented research catchment in north-central Minnesota. SRHA surface waters exhibit δ18O seasonal variations similar to those of groundwaters, and seasonal δ18O variations plotted versus time fit seasonal sine functions. These seasonal δ18O variations were interpreted to estimate surface water and groundwater mean residence times (MRTs) at sampling locations near topographically closed-basin lakes. MRT variations of about 1 to 16 years have been estimated over an area covering about 9 km2 from the basin boundary to the most downgradient well. Estimated MRT error (±0·3 to ±0·7 years) is small for short MRTs and is much larger (±10 years) for a well with an MRT (16 years) near the limit of the method. Groundwater transit time estimates based on Darcy's law, tritium content, and the seasonal δ18O amplitude approach appear to be consistent within the limits of each method. The results from this study suggest that use of the δ18O seasonal variation method to determine MRTs can help assess groundwater recharge areas in small headwaters catchments.
-
Gallego, Sergi; Márquez, Andrés; Méndez, David; Ortuño, Manuel; Neipp, Cristian; Fernández, Elena; Pascual, Inmaculada; Beléndez, Augusto
2008-05-10
One of the problems associated with photopolymers as optical recording media is the thickness variation during the recording process. Different values of shrinkages or swelling are reported in the literature for photopolymers. Furthermore, these variations depend on the spatial frequencies of the gratings stored in the materials. Thickness variations can be measured using different methods: studying the deviation from the Bragg's angle for nonslanted gratings, using MicroXAM S/N 8038 interferometer, or by the thermomechanical analysis experiments. In a previous paper, we began the characterization of the properties of a polyvinyl alcohol/acrylamide based photopolymer at the lowest end of recorded spatial frequencies. In this work, we continue analyzing the thickness variations of these materials using a reflection interferometer. With this technique we are able to obtain the variations of the layers refractive index and, therefore, a direct estimation of the polymer refractive index.
-
Geometric constrained variational calculus. II: The second variation (Part I)
NASA Astrophysics Data System (ADS)
Massa, Enrico; Bruno, Danilo; Luria, Gianvittorio; Pagani, Enrico
2016-10-01
Within the geometrical framework developed in [Geometric constrained variational calculus. I: Piecewise smooth extremals, Int. J. Geom. Methods Mod. Phys. 12 (2015) 1550061], the problem of minimality for constrained calculus of variations is analyzed among the class of differentiable curves. A fully covariant representation of the second variation of the action functional, based on a suitable gauge transformation of the Lagrangian, is explicitly worked out. Both necessary and sufficient conditions for minimality are proved, and reinterpreted in terms of Jacobi fields.
-
SCHOOL DROPOUTS--A COMMENTARY AND ANNOTATED BIBLIOGRAPHY.
ERIC Educational Resources Information Center
MILLER, S.M.; AND OTHERS
RESEARCH ON SCHOOL DROPOUTS IS HANDICAPPED IN THE FOLLOWING AREAS--DEFINITION OF THE DROPOUT POPULATION, INCONSISTENT METHODS OF DATA COLLECTION, INADEQUATE RESEARCH DESIGNS, COMMUNITY VARIATION, VARIATION IN TYPE OF DROPOUT, AND KNOWLEDGE OF THE PROCESS OF DROPPING OUT. DROPOUT GROUPS SHOULD BE CLEARLY DEFINED, AND VARIATION IN THESE GROUPS…
-
NASA Astrophysics Data System (ADS)
Palmer, Troy A.; Alexay, Christopher C.
2006-05-01
This paper addresses the variety and impact of dispersive model variations for infrared materials and, in particular, the level to which certain optical designs are affected by this potential variation in germanium. This work offers a method for anticipating and/or minimizing the pitfalls such potential model variations may have on a candidate optical design.
-
Method of calibrating an interferometer and reducing its systematic noise
NASA Technical Reports Server (NTRS)
Hammer, Philip D. (Inventor)
1997-01-01
Methods of operation and data analysis for an interferometer so as to eliminate the errors contributed by non-responsive or unstable pixels, interpixel gain variations that drift over time, and spurious noise that would otherwise degrade the operation of the interferometer are disclosed. The methods provide for either online or post-processing calibration. The methods apply prescribed reversible transformations that exploit the physical properties of interferograms obtained from said interferometer to derive a calibration reference signal for subsequent treatment of said interferograms for interpixel gain variations. A self-consistent approach for treating bad pixels is incorporated into the methods.
-
Hatch, Christine E; Fisher, Andrew T.; Revenaugh, Justin S.; Constantz, Jim; Ruehl, Chris
2006-01-01
We present a method for determining streambed seepage rates using time series thermal data. The new method is based on quantifying changes in phase and amplitude of temperature variations between pairs of subsurface sensors. For a reasonable range of streambed thermal properties and sensor spacings the time series method should allow reliable estimation of seepage rates for a range of at least ±10 m d−1 (±1.2 × 10−2 m s−1), with amplitude variations being most sensitive at low flow rates and phase variations retaining sensitivity out to much higher rates. Compared to forward modeling, the new method requires less observational data and less setup and data handling and is faster, particularly when interpreting many long data sets. The time series method is insensitive to streambed scour and sedimentation, which allows for application under a wide range of flow conditions and allows time series estimation of variable streambed hydraulic conductivity. This new approach should facilitate wider use of thermal methods and improve understanding of the complex spatial and temporal dynamics of surface water–groundwater interactions.
-
ERIC Educational Resources Information Center
Bull, Rebecca; Espy, Kimberly Andrews; Wiebe, Sandra A.; Sheffield, Tiffany D.; Nelson, Jennifer Mize
2011-01-01
Latent variable modeling methods have demonstrated utility for understanding the structure of executive control (EC) across development. These methods are utilized to better characterize the relation between EC and mathematics achievement in the preschool period, and to understand contributing sources of individual variation. Using the sample and…
-
Length polymorphism scanning is an efficient approach for revealing chloroplast DNA variation.
Matthew E. Horning; Richard C. Cronn
2006-01-01
Phylogeographic and population genetic screens of chloroplast DNA (cpDNA) provide insights into seedbased gene flow in angiosperms, yet studies are frequently hampered by the low mutation rate of this genome. Detection methods for intraspecific variation can be either direct (DNA sequencing) or indirect (PCR-RFLP), although no single method incorporates the best...
-
Variational method for lattice spectroscopy with ghosts
DOE Office of Scientific and Technical Information (OSTI.GOV)
Burch, Tommy; Hagen, Christian; Gattringer, Christof
2006-01-01
We discuss the variational method used in lattice spectroscopy calculations. In particular we address the role of ghost contributions which appear in quenched or partially quenched simulations and have a nonstandard euclidean time dependence. We show that the ghosts can be separated from the physical states. Our result is illustrated with numerical data for the scalar meson.
-
A FORTRAN Program for Computing Refractive Index Using the Double Variation Method.
ERIC Educational Resources Information Center
Blanchard, Frank N.
1984-01-01
Describes a computer program which calculates a best estimate of refractive index and dispersion from a large number of observations using the double variation method of measuring refractive index along with Sellmeier constants of the immersion oils. Program listing with examples will be provided on written request to the author. (Author/JM)
-
Systematic Convergence in Applying Variational Method to Double-Well Potential
ERIC Educational Resources Information Center
Mei, Wai-Ning
2016-01-01
In this work, we demonstrate the application of the variational method by computing the ground- and first-excited state energies of a double-well potential. We start with the proper choice of the trial wave functions using optimized parameters, and notice that accurate expectation values in excellent agreement with the numerical results can be…
-
An Evaluation Method of Words Tendency Depending on Time-Series Variation and Its Improvements.
ERIC Educational Resources Information Center
Atlam, El-Sayed; Okada, Makoto; Shishibori, Masami; Aoe, Jun-ichi
2002-01-01
Discussion of word frequency and keywords in text focuses on a method to estimate automatically the stability classes that indicate a word's popularity with time-series variations based on the frequency change in past electronic text data. Compares the evaluation of decision tree stability class results with manual classification results.…
-
Thompson, David N; Thompson, Vicki S; Schaller, Kastli D; Apel, William A; Reed, David W; Lacey, Jeffrey A
2013-04-30
Isolated and/or purified polypeptides and nucleic acid sequences encoding polypeptides from Alicyclobacillus acidocaldarius and variations thereof are provided. Further provided are methods of at least partially degrading xylotriose, xylobiose, and/or arabinofuranose-substituted xylan using isolated and/or purified polypeptides and nucleic acid sequences encoding polypeptides from Alicyclobacillus acidocaldarius and variations thereof.
-
A Simple Demonstration of a General Rule for the Variation of Magnetic Field with Distance
ERIC Educational Resources Information Center
Kodama, K.
2009-01-01
We describe a simple experiment demonstrating the variation in magnitude of a magnetic field with distance. The method described requires only an ordinary magnetic compass and a permanent magnet. The proposed graphical analysis illustrates a unique method for deducing a general rule of magnetostatics. (Contains 1 table and 6 figures.)
-
ERIC Educational Resources Information Center
Mahavier, W. Ted
2002-01-01
Describes a two-semester numerical methods course that serves as a research experience for undergraduate students without requiring external funding or the modification of current curriculum. Uses an engineering problem to introduce students to constrained optimization via a variation of the traditional isoperimetric problem of finding the curve…
-
Developments in variational methods for high performance plate and shell elements
NASA Technical Reports Server (NTRS)
Felippa, Carlos A.; Militello, Carmelo
1991-01-01
High performance elements are simple finite elements constructed to deliver engineering accuracy with coarse arbitrary grids. This is part of a series on the variational foundations of high-performance elements, with emphasis on plate and shell elements constructed with the free formulation (FF) and assumed natural strain (ANS) methods. Parameterized variational principles are studied that provide a common foundation for the FF and ANS methods, as well as for a combination of both. From this unified formulation a variant of the ANS formulation, called the assumed natural deviatoric strain (ANDES) formulation, emerges as an important special case. The first ANDES element, a high-performance 9 degrees of freedom triangular Kirchhoff plate bending element, is briefly described to illustrate the use of the new formulation.
-
Estimating nonrigid motion from inconsistent intensity with robust shape features
DOE Office of Scientific and Technical Information (OSTI.GOV)
Liu, Wenyang; Ruan, Dan, E-mail: druan@mednet.ucla.edu; Department of Radiation Oncology, University of California, Los Angeles, California 90095
2013-12-15
Purpose: To develop a nonrigid motion estimation method that is robust to heterogeneous intensity inconsistencies amongst the image pairs or image sequence. Methods: Intensity and contrast variations, as in dynamic contrast enhanced magnetic resonance imaging, present a considerable challenge to registration methods based on general discrepancy metrics. In this study, the authors propose and validate a novel method that is robust to such variations by utilizing shape features. The geometry of interest (GOI) is represented with a flexible zero level set, segmented via well-behaved regularized optimization. The optimization energy drives the zero level set to high image gradient regions, andmore » regularizes it with area and curvature priors. The resulting shape exhibits high consistency even in the presence of intensity or contrast variations. Subsequently, a multiscale nonrigid registration is performed to seek a regular deformation field that minimizes shape discrepancy in the vicinity of GOIs. Results: To establish the working principle, realistic 2D and 3D images were subject to simulated nonrigid motion and synthetic intensity variations, so as to enable quantitative evaluation of registration performance. The proposed method was benchmarked against three alternative registration approaches, specifically, optical flow, B-spline based mutual information, and multimodality demons. When intensity consistency was satisfied, all methods had comparable registration accuracy for the GOIs. When intensities among registration pairs were inconsistent, however, the proposed method yielded pronounced improvement in registration accuracy, with an approximate fivefold reduction in mean absolute error (MAE = 2.25 mm, SD = 0.98 mm), compared to optical flow (MAE = 9.23 mm, SD = 5.36 mm), B-spline based mutual information (MAE = 9.57 mm, SD = 8.74 mm) and mutimodality demons (MAE = 10.07 mm, SD = 4.03 mm). Applying the proposed method on a real MR image sequence also provided qualitatively appealing results, demonstrating good feasibility and applicability of the proposed method. Conclusions: The authors have developed a novel method to estimate the nonrigid motion of GOIs in the presence of spatial intensity and contrast variations, taking advantage of robust shape features. Quantitative analysis and qualitative evaluation demonstrated good promise of the proposed method. Further clinical assessment and validation is being performed.« less
-
GEMINI: Integrative Exploration of Genetic Variation and Genome Annotations
Paila, Umadevi; Chapman, Brad A.; Kirchner, Rory; Quinlan, Aaron R.
2013-01-01
Modern DNA sequencing technologies enable geneticists to rapidly identify genetic variation among many human genomes. However, isolating the minority of variants underlying disease remains an important, yet formidable challenge for medical genetics. We have developed GEMINI (GEnome MINIng), a flexible software package for exploring all forms of human genetic variation. Unlike existing tools, GEMINI integrates genetic variation with a diverse and adaptable set of genome annotations (e.g., dbSNP, ENCODE, UCSC, ClinVar, KEGG) into a unified database to facilitate interpretation and data exploration. Whereas other methods provide an inflexible set of variant filters or prioritization methods, GEMINI allows researchers to compose complex queries based on sample genotypes, inheritance patterns, and both pre-installed and custom genome annotations. GEMINI also provides methods for ad hoc queries and data exploration, a simple programming interface for custom analyses that leverage the underlying database, and both command line and graphical tools for common analyses. We demonstrate GEMINI's utility for exploring variation in personal genomes and family based genetic studies, and illustrate its ability to scale to studies involving thousands of human samples. GEMINI is designed for reproducibility and flexibility and our goal is to provide researchers with a standard framework for medical genomics. PMID:23874191
-
Method for Reducing Pumping Damage to Blood
NASA Technical Reports Server (NTRS)
Bozeman, Richard J., Jr. (Inventor); Akkerman, James W. (Inventor); Aber, Gregory S. (Inventor); VanDamm, George Arthur (Inventor); Bacak, James W. (Inventor); Svejkovsky, Robert J. (Inventor); Benkowski, Robert J. (Inventor)
1997-01-01
Methods are provided for minimizing damage to blood in a blood pump wherein the blood pump comprises a plurality of pump components that may affect blood damage such as clearance between pump blades and housing, number of impeller blades, rounded or flat blade edges, variations in entrance angles of blades, impeller length, and the like. The process comprises selecting a plurality of pump components believed to affect blood damage such as those listed herein before. Construction variations for each of the plurality of pump components are then selected. The pump components and variations are preferably listed in a matrix for easy visual comparison of test results. Blood is circulated through a pump configuration to test each variation of each pump component. After each test, total blood damage is determined for the blood pump. Preferably each pump component variation is tested at least three times to provide statistical results and check consistency of results. The least hemolytic variation for each pump component is preferably selected as an optimized component. If no statistical difference as to blood damage is produced for a variation of a pump component, then the variation that provides preferred hydrodynamic performance is selected. To compare the variation of pump components such as impeller and stator blade geometries, the preferred embodiment of the invention uses a stereolithography technique for realizing complex shapes within a short time period.
-
A methodology for probabilistic remaining creep life assessment of gas turbine components
NASA Astrophysics Data System (ADS)
Liu, Zhimin
Certain gas turbine components operate in harsh environments and various mechanisms may lead to component failure. It is common practice to use remaining life assessments to help operators schedule maintenance and component replacements. Creep is a major failure mechanisms that affect the remaining life assessment, and the resulting life consumption of a component is highly sensitive to variations in the material stresses and temperatures, which fluctuate significantly due to the changes in real operating conditions. In addition, variations in material properties and geometry will result in changes in creep life consumption rate. The traditional method used for remaining life assessment assumes a set of fixed operating conditions at all times, and it fails to capture the variations in operating conditions. This translates into a significant loss of accuracy and unnecessary high maintenance and replacement cost. A new method that captures these variations described above and improves the prediction accuracy of remaining life is developed. First, a metamodel is built to approximate the relationship between variables (operating conditions, material properties, geometry, etc.) and a creep response. The metamodel is developed using Response Surface Method/Design of Experiments methodology. Design of Experiments is an efficient sampling method, and for each sampling point a set of finite element analyses are used to compute the corresponding response value. Next, a low order polynomial Response Surface Equation (RSE) is used to fit these values. Four techniques are suggested to dramatically reduce computational effort, and to increase the accuracy of the RSE: smart meshing technique, automatic geometry parameterization, screening test and regional RSE refinement. The RSEs, along with a probabilistic method and a life fraction model are used to compute current damage accumulation and remaining life. By capturing the variations mentioned above, the new method results in much better accuracy than that available using the traditional method. After further development and proper verification the method should bring significant savings by reducing the number of inspections and deferring part replacement.
-
A coupled mode formulation by reciprocity and a variational principle
NASA Technical Reports Server (NTRS)
Chuang, Shun-Lien
1987-01-01
A coupled mode formulation for parallel dielectric waveguides is presented via two methods: a reciprocity theorem and a variational principle. In the first method, a generalized reciprocity relation for two sets of field solutions satisfying Maxwell's equations and the boundary conditions in two different media, respectively, is derived. Based on the generalized reciprocity theorem, the coupled mode equations can then be formulated. The second method using a variational principle is also presented for a general waveguide system which can be lossy. The results of the variational principle can also be shown to be identical to those from the reciprocity theorem. The exact relations governing the 'conventional' and the new coupling coefficients are derived. It is shown analytically that the present formulation satisfies the reciprocity theorem and power conservation exactly, while the conventional theory violates the power conservation and reciprocity theorem by as much as 55 percent and the Hardy-Streifer (1985, 1986) theory by 0.033 percent, for example.
-
NASA Astrophysics Data System (ADS)
Suhartono, Lee, Muhammad Hisyam; Prastyo, Dedy Dwi
2015-12-01
The aim of this research is to develop a calendar variation model for forecasting retail sales data with the Eid ul-Fitr effect. The proposed model is based on two methods, namely two levels ARIMAX and regression methods. Two levels ARIMAX and regression models are built by using ARIMAX for the first level and regression for the second level. Monthly men's jeans and women's trousers sales in a retail company for the period January 2002 to September 2009 are used as case study. In general, two levels of calendar variation model yields two models, namely the first model to reconstruct the sales pattern that already occurred, and the second model to forecast the effect of increasing sales due to Eid ul-Fitr that affected sales at the same and the previous months. The results show that the proposed two level calendar variation model based on ARIMAX and regression methods yields better forecast compared to the seasonal ARIMA model and Neural Networks.
-
Vertical profiles of wind and temperature by remote acoustical sounding
NASA Technical Reports Server (NTRS)
Fox, H. L.
1969-01-01
An acoustical method was investigated for obtaining meteorological soundings based on the refraction due to the vertical variation of wind and temperature. The method has the potential of yielding horizontally averaged measurements of the vertical variation of wind and temperature up to heights of a few kilometers; the averaging takes place over a radius of 10 to 15 km. An outline of the basic concepts and some of the results obtained with the method are presented.
-
NASA Astrophysics Data System (ADS)
Chan, W. Y.; Eggins, S. M.
2017-09-01
Significant diurnal variation in seawater carbonate chemistry occurs naturally in many coral reef environments, yet little is known of its effect on coral calcification. Laboratory studies on the response of corals to ocean acidification have manipulated the carbonate chemistry of experimental seawater to compare calcification rate changes under present-day and predicted future mean pH/Ωarag conditions. These experiments, however, have focused exclusively on differences in mean chemistry and have not considered diurnal variation. The aim of this study was to compare calcification responses of branching coral Acropora formosa under conditions with and without diurnal variation in seawater carbonate chemistry. To achieve this aim, we explored (1) a method to recreate natural diurnal variation in a laboratory experiment using the biological activities of a coral-reef mesocosm, and (2) a multi-laser 3D scanning method to accurately measure coral surface areas, essential to normalize their calcification rates. We present a cost- and time-efficient method of coral surface area estimation that is reproducible within 2% of the mean of triplicate measurements. Calcification rates were compared among corals subjected to a diurnal range in pH (total scale) from 7.8 to 8.2, relative to those at constant pH values of 7.8, 8.0 or 8.2. Mean calcification rates of the corals at the pH 7.8-8.2 (diurnal variation) treatment were not statistically different from the pH 8.2 treatment and were 34% higher than the pH 8.0 treatment despite similar mean seawater pH and Ωarag. Our results suggest that calcification of adult coral colonies may benefit from diurnal variation in seawater carbonate chemistry. Experiments that compare calcification rates at different constant pH without considering diurnal variation may have limitations.
-
NASA Astrophysics Data System (ADS)
Yong, Peng; Liao, Wenyuan; Huang, Jianping; Li, Zhenchuan
2018-04-01
Full waveform inversion is an effective tool for recovering the properties of the Earth from seismograms. However, it suffers from local minima caused mainly by the limited accuracy of the starting model and the lack of a low-frequency component in the seismic data. Because of the high velocity contrast between salt and sediment, the relation between the waveform and velocity perturbation is strongly nonlinear. Therefore, salt inversion can easily get trapped in the local minima. Since the velocity of salt is nearly constant, we can make the most of this characteristic with total variation regularization to mitigate the local minima. In this paper, we develop an adaptive primal dual hybrid gradient method to implement total variation regularization by projecting the solution onto a total variation norm constrained convex set, through which the total variation norm constraint is satisfied at every model iteration. The smooth background velocities are first inverted and the perturbations are gradually obtained by successively relaxing the total variation norm constraints. Numerical experiment of the projection of the BP model onto the intersection of the total variation norm and box constraints has demonstrated the accuracy and efficiency of our adaptive primal dual hybrid gradient method. A workflow is designed to recover complex salt structures in the BP 2004 model and the 2D SEG/EAGE salt model, starting from a linear gradient model without using low-frequency data below 3 Hz. The salt inversion processes demonstrate that wavefield reconstruction inversion with a total variation norm and box constraints is able to overcome local minima and inverts the complex salt velocity layer by layer.
-
NASA Astrophysics Data System (ADS)
Sun, M. L.; Peng, H. B.; Duan, B. H.; Liu, F. F.; Du, X.; Yuan, W.; Zhang, B. T.; Zhang, X. Y.; Wang, T. S.
2018-03-01
Borosilicate glass has potential application for vitrification of high-level radioactive waste, which attracts extensive interest in studying its radiation durability. In this study, sodium borosilicate glass samples were irradiated with 4 MeV Kr17+ ion, 5 MeV Xe26+ ion and 0.3 MeV P+ ion, respectively. The hardness of irradiated borosilicate glass samples was measured with nanoindentation in continuous stiffness mode and quasi continuous stiffness mode, separately. Extrapolation method, mean value method, squared extrapolation method and selected point method are used to obtain hardness of irradiated glass and a comparison among these four methods is conducted. The extrapolation method is suggested to analyze the hardness of ion irradiated glass. With increasing irradiation dose, the values of hardness for samples irradiated with Kr, Xe and P ions dropped and then saturated at 0.02 dpa. Besides, both the maximum variations and decay constants for three kinds of ions with different energies are similar indicates the similarity behind the hardness variation in glasses after irradiation. Furthermore, the hardness variation of low energy P ion irradiated samples whose range is much smaller than those of high energy Kr and Xe ions, has the same trend as that of Kr and Xe ions. It suggested that electronic energy loss did not play a significant role in hardness decrease for irradiation of low energy ions.
-
Zhao, Guangju; Mu, Xingmin; Jiao, Juying; Gao, Peng; Sun, Wenyi; Li, Erhui; Wei, Yanhong; Huang, Jiacong
2018-05-23
Understanding the relative contributions of climate change and human activities to variations in sediment load is of great importance for regional soil, and river basin management. Considerable studies have investigated spatial-temporal variation of sediment load within the Loess Plateau; however, contradictory findings exist among methods used. This study systematically reviewed six quantitative methods: simple linear regression, double mass curve, sediment identity factor analysis, dam-sedimentation based method, the Sediment Delivery Distributed (SEDD) model, and the Soil Water Assessment Tool (SWAT) model. The calculation procedures and merits for each method were systematically explained. A case study in the Huangfuchuan watershed on the northern Loess Plateau has been undertaken. The results showed that sediment load had been reduced by 70.5% during the changing period from 1990 to 2012 compared to that of the baseline period from 1955 to 1989. Human activities accounted for an average of 93.6 ± 4.1% of the total decline in sediment load, whereas climate change contributed 6.4 ± 4.1%. Five methods produced similar estimates, but the linear regression yielded relatively different results. The results of this study provide a good reference for assessing the effects of climate change and human activities on sediment load variation by using different methods. Copyright © 2018. Published by Elsevier B.V.
-
Scene-based nonuniformity correction using local constant statistics.
Zhang, Chao; Zhao, Wenyi
2008-06-01
In scene-based nonuniformity correction, the statistical approach assumes all possible values of the true-scene pixel are seen at each pixel location. This global-constant-statistics assumption does not distinguish fixed pattern noise from spatial variations in the average image. This often causes the "ghosting" artifacts in the corrected images since the existing spatial variations are treated as noises. We introduce a new statistical method to reduce the ghosting artifacts. Our method proposes a local-constant statistics that assumes that the temporal signal distribution is not constant at each pixel but is locally true. This considers statistically a constant distribution in a local region around each pixel but uneven distribution in a larger scale. Under the assumption that the fixed pattern noise concentrates in a higher spatial-frequency domain than the distribution variation, we apply a wavelet method to the gain and offset image of the noise and separate out the pattern noise from the spatial variations in the temporal distribution of the scene. We compare the results to the global-constant-statistics method using a clean sequence with large artificial pattern noises. We also apply the method to a challenging CCD video sequence and a LWIR sequence to show how effective it is in reducing noise and the ghosting artifacts.
-
Image denoising by a direct variational minimization
NASA Astrophysics Data System (ADS)
Janev, Marko; Atanacković, Teodor; Pilipović, Stevan; Obradović, Radovan
2011-12-01
In this article we introduce a novel method for the image de-noising which combines a mathematically well-posdenes of the variational modeling with the efficiency of a patch-based approach in the field of image processing. It based on a direct minimization of an energy functional containing a minimal surface regularizer that uses fractional gradient. The minimization is obtained on every predefined patch of the image, independently. By doing so, we avoid the use of an artificial time PDE model with its inherent problems of finding optimal stopping time, as well as the optimal time step. Moreover, we control the level of image smoothing on each patch (and thus on the whole image) by adapting the Lagrange multiplier using the information on the level of discontinuities on a particular patch, which we obtain by pre-processing. In order to reduce the average number of vectors in the approximation generator and still to obtain the minimal degradation, we combine a Ritz variational method for the actual minimization on a patch, and a complementary fractional variational principle. Thus, the proposed method becomes computationally feasible and applicable for practical purposes. We confirm our claims with experimental results, by comparing the proposed method with a couple of PDE-based methods, where we get significantly better denoising results specially on the oscillatory regions.
-
Variational optical flow computation in real time.
Bruhn, Andrés; Weickert, Joachim; Feddern, Christian; Kohlberger, Timo; Schnörr, Christoph
2005-05-01
This paper investigates the usefulness of bidirectional multigrid methods for variational optical flow computations. Although these numerical schemes are among the fastest methods for solving equation systems, they are rarely applied in the field of computer vision. We demonstrate how to employ those numerical methods for the treatment of variational optical flow formulations and show that the efficiency of this approach even allows for real-time performance on standard PCs. As a representative for variational optic flow methods, we consider the recently introduced combined local-global method. It can be considered as a noise-robust generalization of the Horn and Schunck technique. We present a decoupled, as well as a coupled, version of the classical Gauss-Seidel solver, and we develop several multgrid implementations based on a discretization coarse grid approximation. In contrast, with standard bidirectional multigrid algorithms, we take advantage of intergrid transfer operators that allow for nondyadic grid hierarchies. As a consequence, no restrictions concerning the image size or the number of traversed levels have to be imposed. In the experimental section, we juxtapose the developed multigrid schemes and demonstrate their superior performance when compared to unidirectional multgrid methods and nonhierachical solvers. For the well-known 316 x 252 Yosemite sequence, we succeeded in computing the complete set of dense flow fields in three quarters of a second on a 3.06-GHz Pentium4 PC. This corresponds to a frame rate of 18 flow fields per second which outperforms the widely-used Gauss-Seidel method by almost three orders of magnitude.
-
When things go pear shaped: contour variations of contacts
NASA Astrophysics Data System (ADS)
Utzny, Clemens
2013-04-01
Traditional control of critical dimensions (CD) on photolithographic masks considers the CD average and a measure for the CD variation such as the CD range or the standard deviation. Also systematic CD deviations from the mean such as CD signatures are subject to the control. These measures are valid for mask quality verification as long as patterns across a mask exhibit only size variations and no shape variation. The issue of shape variations becomes especially important in the context of contact holes on EUV masks. For EUV masks the CD error budget is much smaller than for standard optical masks. This means that small deviations from the contact shape can impact EUV waver prints in the sense that contact shape deformations induce asymmetric bridging phenomena. In this paper we present a detailed study of contact shape variations based on regular product data. Two data sets are analyzed: 1) contacts of varying target size and 2) a regularly spaced field of contacts. Here, the methods of statistical shape analysis are used to analyze CD SEM generated contour data. We demonstrate that contacts on photolithographic masks do not only show size variations but exhibit also pronounced nontrivial shape variations. In our data sets we find pronounced shape variations which can be interpreted as asymmetrical shape squeezing and contact rounding. Thus we demonstrate the limitations of classic CD measures for describing the feature variations on masks. Furthermore we show how the methods of statistical shape analysis can be used for quantifying the contour variations thus paving the way to a new understanding of mask linearity and its specification.
-
NASA Technical Reports Server (NTRS)
Roth, Don J.
1998-01-01
NASA Lewis Research Center's Life Prediction Branch, in partnership with Sonix, Inc., and Cleveland State University, recently advanced the development of, refined, and commercialized an advanced nondestructive evaluation (NDE) inspection method entitled the Single Transducer Thickness-Independent Ultrasonic Imaging Method. Selected by R&D Magazine as one of the 100 most technologically significant new products of 1996, the method uses a single transducer to eliminate the superimposing effects of thickness variation in the ultrasonic images of materials. As a result, any variation seen in the image is due solely to microstructural variation. This nondestructive method precisely and accurately characterizes material gradients (pore fraction, density, or chemical) that affect the uniformity of a material's physical performance (mechanical, thermal, or electrical). Advantages of the method over conventional ultrasonic imaging include (1) elimination of machining costs (for precision thickness control) during the quality control stages of material processing and development and (2) elimination of labor costs and subjectivity involved in further image processing and image interpretation. At NASA Lewis, the method has been used primarily for accurate inspections of high temperature structural materials including monolithic ceramics, metal matrix composites, and polymer matrix composites. Data were published this year for platelike samples, and current research is focusing on applying the method to tubular components. The initial publicity regarding the development of the method generated 150 requests for further information from a wide variety of institutions and individuals including the Federal Bureau of Investigation (FBI), Lockheed Martin Corporation, Rockwell International, Hewlett Packard Company, and Procter & Gamble Company. In addition, NASA has been solicited by the 3M Company and Allison Abrasives to use this method to inspect composite materials that are manufactured by these companies.
-
NASA Technical Reports Server (NTRS)
Mirels, Harold
1959-01-01
A source distribution method is presented for obtaining flow perturbations due to small unsteady area variations, mass, momentum, and heat additions in a basic uniform (or piecewise uniform) one-dimensional flow. First, the perturbations due to an elemental area variation, mass, momentum, and heat addition are found. The general solution is then represented by a spatial and temporal distribution of these elemental (source) solutions. Emphasis is placed on discussing the physical nature of the flow phenomena. The method is illustrated by several examples. These include the determination of perturbations in basic flows consisting of (1) a shock propagating through a nonuniform tube, (2) a constant-velocity piston driving a shock, (3) ideal shock-tube flows, and (4) deflagrations initiated at a closed end. The method is particularly applicable for finding the perturbations due to relatively thin wall boundary layers.
-
Analog graphic display method and apparatus
Kronberg, J.W.
1991-08-13
Disclosed are an apparatus and method for using an output device such as an LED to show the approximate analog level of a variable electrical signal wherein a modulating AC waveform is superimposed either on the signal or a reference voltage, both of which are then fed to a comparator which drives the output device. Said device flashes at a constant perceptible rate with a duty cycle which varies in response to variations in the level of the input signal. The human eye perceives these variations in duty cycle as analogous to variations in the level of the input signal. 21 figures.
-
Total variation approach for adaptive nonuniformity correction in focal-plane arrays.
Vera, Esteban; Meza, Pablo; Torres, Sergio
2011-01-15
In this Letter we propose an adaptive scene-based nonuniformity correction method for fixed-pattern noise removal in imaging arrays. It is based on the minimization of the total variation of the estimated irradiance, and the resulting function is optimized by an isotropic total variation approach making use of an alternating minimization strategy. The proposed method provides enhanced results when applied to a diverse set of real IR imagery, accurately estimating the nonunifomity parameters of each detector in the focal-plane array at a fast convergence rate, while also forming fewer ghosting artifacts.
-
Analog graphic display method and apparatus
Kronberg, James W.
1991-01-01
An apparatus and method for using an output device such as an LED to show the approximate analog level of a variable electrical signal wherein a modulating AC waveform is superimposed either on the signal or a reference voltage, both of which are then fed to a comparator which drives the output device. Said device flashes at a constant perceptible rate with a duty cycle which varies in response to variations in the level of the input signal. The human eye perceives these variations in duty cycle as analogous to variations in the level of the input signal.
-
Peselnick, L.; Meister, R.
1965-01-01
Variational principles of anisotropic elasticity have been applied to aggregates of randomly oriented pure-phase polycrystals having hexagonal symmetry and trigonal symmetry. The bounds of the effective elastic moduli obtained in this way show a considerable improvement over the bounds obtained by means of the Voigt and Reuss assumptions. The Hill average is found to be in most cases a good approximation when compared to the bounds found from the variational method. The new bounds reduce in their limits to the Voigt and Reuss values. ?? 1965 The American Institute of Physics.
-
An MHD variational principle that admits reconnection
NASA Technical Reports Server (NTRS)
Rilee, M. L.; Sudan, R. N.; Pfirsch, D.
1997-01-01
The variational approach of Pfirsch and Sudan's averaged magnetohydrodynamics (MHD) to the stability of a line-tied current layer is summarized. The effect of line-tying on current sheets that might arise in line-tied magnetic flux tubes by estimating the growth rates of a resistive instability using a variational method. The results show that this method provides a potentially new technique to gauge the stability of nearly ideal magnetohydrodynamic systems. The primary implication for the stability of solar coronal structures is that tearing modes are probably constant at work removing magnetic shear from the solar corona.
-
Li, Hui
2009-11-14
Linear response and variational treatment are formulated for Hartree-Fock (HF) and Kohn-Sham density functional theory (DFT) methods and combined discrete-continuum solvation models that incorporate self-consistently induced dipoles and charges. Due to the variational treatment, analytic nuclear gradients can be evaluated efficiently for these discrete and continuum solvation models. The forces and torques on the induced point dipoles and point charges can be evaluated using simple electrostatic formulas as for permanent point dipoles and point charges, in accordance with the electrostatic nature of these methods. Implementation and tests using the effective fragment potential (EFP, a polarizable force field) method and the conductorlike polarizable continuum model (CPCM) show that the nuclear gradients are as accurate as those in the gas phase HF and DFT methods. Using B3LYP/EFP/CPCM and time-dependent-B3LYP/EFP/CPCM methods, acetone S(0)-->S(1) excitation in aqueous solution is studied. The results are close to those from full B3LYP/CPCM calculations.
-
NASA Astrophysics Data System (ADS)
Miura, Shinichi
2018-03-01
In this paper, the ground state of para-hydrogen clusters for size regime N ≤ 40 has been studied by our variational path integral molecular dynamics method. Long molecular dynamics calculations have been performed to accurately evaluate ground state properties. The chemical potential of the hydrogen molecule is found to have a zigzag size dependence, indicating the magic number stability for the clusters of the size N = 13, 26, 29, 34, and 39. One-body density of the hydrogen molecule is demonstrated to have a structured profile, not a melted one. The observed magic number stability is examined using the inherent structure analysis. We also have developed a novel method combining our variational path integral hybrid Monte Carlo method with the replica exchange technique. We introduce replicas of the original system bridging from the structured to the melted cluster, which is realized by scaling the potential energy of the system. Using the enhanced sampling method, the clusters are demonstrated to have the structured density profile in the ground state.
-
Miura, Shinichi
2018-03-14
In this paper, the ground state of para-hydrogen clusters for size regime N ≤ 40 has been studied by our variational path integral molecular dynamics method. Long molecular dynamics calculations have been performed to accurately evaluate ground state properties. The chemical potential of the hydrogen molecule is found to have a zigzag size dependence, indicating the magic number stability for the clusters of the size N = 13, 26, 29, 34, and 39. One-body density of the hydrogen molecule is demonstrated to have a structured profile, not a melted one. The observed magic number stability is examined using the inherent structure analysis. We also have developed a novel method combining our variational path integral hybrid Monte Carlo method with the replica exchange technique. We introduce replicas of the original system bridging from the structured to the melted cluster, which is realized by scaling the potential energy of the system. Using the enhanced sampling method, the clusters are demonstrated to have the structured density profile in the ground state.
-
NASA Astrophysics Data System (ADS)
Hai-Jung In,; Oh-Kyong Kwon,
2010-03-01
A simple pixel structure using a video data correction method is proposed to compensate for electrical characteristic variations of driving thin-film transistors (TFTs) and the degradation of organic light-emitting diodes (OLEDs) in active-matrix OLED (AMOLED) displays. The proposed method senses the electrical characteristic variations of TFTs and OLEDs and stores them in external memory. The nonuniform emission current of TFTs and the aging of OLEDs are corrected by modulating video data using the stored data. Experimental results show that the emission current error due to electrical characteristic variation of driving TFTs is in the range from -63.1 to 61.4% without compensation, but is decreased to the range from -1.9 to 1.9% with the proposed correction method. The luminance error due to the degradation of an OLED is less than 1.8% when the proposed correction method is used for a 50% degraded OLED.
-
NASA Astrophysics Data System (ADS)
Kamibayashi, Yuki; Miura, Shinichi
2016-08-01
In the present study, variational path integral molecular dynamics and associated hybrid Monte Carlo (HMC) methods have been developed on the basis of a fourth order approximation of a density operator. To reveal various parameter dependence of physical quantities, we analytically solve one dimensional harmonic oscillators by the variational path integral; as a byproduct, we obtain the analytical expression of the discretized density matrix using the fourth order approximation for the oscillators. Then, we apply our methods to realistic systems like a water molecule and a para-hydrogen cluster. In the HMC, we adopt two level description to avoid the time consuming Hessian evaluation. For the systems examined in this paper, the HMC method is found to be about three times more efficient than the molecular dynamics method if appropriate HMC parameters are adopted; the advantage of the HMC method is suggested to be more evident for systems described by many body interaction.
-
NASA Astrophysics Data System (ADS)
Rezeau, L.; Belmont, G.; Manuzzo, R.; Aunai, N.; Dargent, J.
2018-01-01
We explore the structure of the magnetopause using a crossing observed by the Magnetospheric Multiscale (MMS) spacecraft on 16 October 2015. Several methods (minimum variance analysis, BV method, and constant velocity analysis) are first applied to compute the normal to the magnetopause considered as a whole. The different results obtained are not identical, and we show that the whole boundary is not stationary and not planar, so that basic assumptions of these methods are not well satisfied. We then analyze more finely the internal structure for investigating the departures from planarity. Using the basic mathematical definition of what is a one-dimensional physical problem, we introduce a new single spacecraft method, called LNA (local normal analysis) for determining the varying normal, and we compare the results so obtained with those coming from the multispacecraft minimum directional derivative (MDD) tool developed by Shi et al. (2005). This last method gives the dimensionality of the magnetic variations from multipoint measurements and also allows estimating the direction of the local normal when the variations are locally 1-D. This study shows that the magnetopause does include approximate one-dimensional substructures but also two- and three-dimensional structures. It also shows that the dimensionality of the magnetic variations can differ from the variations of other fields so that, at some places, the magnetic field can have a 1-D structure although all the plasma variations do not verify the properties of a global one-dimensional problem. A generalization of the MDD tool is proposed.
-
Estimating nonrigid motion from inconsistent intensity with robust shape features.
Liu, Wenyang; Ruan, Dan
2013-12-01
To develop a nonrigid motion estimation method that is robust to heterogeneous intensity inconsistencies amongst the image pairs or image sequence. Intensity and contrast variations, as in dynamic contrast enhanced magnetic resonance imaging, present a considerable challenge to registration methods based on general discrepancy metrics. In this study, the authors propose and validate a novel method that is robust to such variations by utilizing shape features. The geometry of interest (GOI) is represented with a flexible zero level set, segmented via well-behaved regularized optimization. The optimization energy drives the zero level set to high image gradient regions, and regularizes it with area and curvature priors. The resulting shape exhibits high consistency even in the presence of intensity or contrast variations. Subsequently, a multiscale nonrigid registration is performed to seek a regular deformation field that minimizes shape discrepancy in the vicinity of GOIs. To establish the working principle, realistic 2D and 3D images were subject to simulated nonrigid motion and synthetic intensity variations, so as to enable quantitative evaluation of registration performance. The proposed method was benchmarked against three alternative registration approaches, specifically, optical flow, B-spline based mutual information, and multimodality demons. When intensity consistency was satisfied, all methods had comparable registration accuracy for the GOIs. When intensities among registration pairs were inconsistent, however, the proposed method yielded pronounced improvement in registration accuracy, with an approximate fivefold reduction in mean absolute error (MAE = 2.25 mm, SD = 0.98 mm), compared to optical flow (MAE = 9.23 mm, SD = 5.36 mm), B-spline based mutual information (MAE = 9.57 mm, SD = 8.74 mm) and mutimodality demons (MAE = 10.07 mm, SD = 4.03 mm). Applying the proposed method on a real MR image sequence also provided qualitatively appealing results, demonstrating good feasibility and applicability of the proposed method. The authors have developed a novel method to estimate the nonrigid motion of GOIs in the presence of spatial intensity and contrast variations, taking advantage of robust shape features. Quantitative analysis and qualitative evaluation demonstrated good promise of the proposed method. Further clinical assessment and validation is being performed.
-
Homodyne chiral polarimetry for measuring thermo-optic refractive index variations.
Twu, Ruey-Ching; Wang, Jhao-Sheng
2015-10-10
Novel reflection-type homodyne chiral polarimetry is proposed for measuring the refractive index variations of a transparent plate under thermal impact. The experimental results show it is a simple and useful method for providing accurate measurements of refractive index variations. The measurement can reach a resolution of 7×10-5.
-
Confidence bounds for normal and lognormal distribution coefficients of variation
Steve Verrill
2003-01-01
This paper compares the so-called exact approach for obtaining confidence intervals on normal distribution coefficients of variation to approximate methods. Approximate approaches were found to perform less well than the exact approach for large coefficients of variation and small sample sizes. Web-based computer programs are described for calculating confidence...
-
Subtelomeric Rearrangements and Copy Number Variations in People with Intellectual Disabilities
ERIC Educational Resources Information Center
Christofolini, D. M.; De Paula Ramos, M. A.; Kulikowski, L. D.; Da Silva Bellucco, F. T.; Belangero, S. I. N.; Brunoni, D.; Melaragno, M. I.
2010-01-01
Background: The most prevalent type of structural variation in the human genome is represented by copy number variations that can affect transcription levels, sequence, structure and function of genes. Method: In the present study, we used the multiplex ligation-dependent probe amplification (MLPA) technique and quantitative PCR for the detection…
-
JOINT AND INDIVIDUAL VARIATION EXPLAINED (JIVE) FOR INTEGRATED ANALYSIS OF MULTIPLE DATA TYPES.
Lock, Eric F; Hoadley, Katherine A; Marron, J S; Nobel, Andrew B
2013-03-01
Research in several fields now requires the analysis of datasets in which multiple high-dimensional types of data are available for a common set of objects. In particular, The Cancer Genome Atlas (TCGA) includes data from several diverse genomic technologies on the same cancerous tumor samples. In this paper we introduce Joint and Individual Variation Explained (JIVE), a general decomposition of variation for the integrated analysis of such datasets. The decomposition consists of three terms: a low-rank approximation capturing joint variation across data types, low-rank approximations for structured variation individual to each data type, and residual noise. JIVE quantifies the amount of joint variation between data types, reduces the dimensionality of the data, and provides new directions for the visual exploration of joint and individual structure. The proposed method represents an extension of Principal Component Analysis and has clear advantages over popular two-block methods such as Canonical Correlation Analysis and Partial Least Squares. A JIVE analysis of gene expression and miRNA data on Glioblastoma Multiforme tumor samples reveals gene-miRNA associations and provides better characterization of tumor types.
-
Short and long periodic atmospheric variations between 25 and 200 km
NASA Technical Reports Server (NTRS)
Justus, C. G.; Woodrum, A.
1973-01-01
Previously collected data on atmospheric pressure, density, temperature and winds between 25 and 200 km from sources including Meteorological Rocket Network data, ROBIN falling sphere data, grenade release and pitot tube data, meteor winds, chemical release winds, satellite data, and others were analyzed by a daily difference method and results on the distribution statistics, magnitude, and spatial structure of gravity wave and planetary wave atmospheric variations are presented. Time structure of the gravity wave variations were determined by the analysis of residuals from harmonic analysis of time series data. Planetary wave contributions in the 25-85 km range were discovered and found to have significant height and latitudinal variation. Long period planetary waves, and seasonal variations were also computed by harmonic analysis. Revised height variations of the gravity wave contributions in the 25 to 85 km height range were computed. An engineering method and design values for gravity wave magnitudes and wave lengths are given to be used for such tasks as evaluating the effects on the dynamical heating, stability and control of spacecraft such as the space shuttle vehicle in launch or reentry trajectories.
-
Money for health: the equivalent variation of cardiovascular diseases.
Groot, Wim; Van Den Brink, Henriëtte Maassen; Plug, Erik
2004-09-01
This paper introduces a new method to calculate the extent to which individuals are willing to trade money for improvements in their health status. An individual welfare function of income (WFI) is applied to calculate the equivalent income variation of health impairments. We believe that this approach avoids various drawbacks of alternative willingness-to-pay methods. The WFI is used to calculate the equivalent variation of cardiovascular diseases. It is found that for a 25 year old male the equivalent variation of a heart disease ranges from 114,000 euro to 380,000 euro depending on the welfare level. This is about 10,000 euro - 30,000 euro for an additional life year. The equivalent variation declines with age and is about the same for men and women. The estimates further vary by discount rate chosen. The estimates of the equivalent variation are generally higher than the money spent on most heart-related medical interventions per QALY. The cost-benefit analysis shows that for most interventions the value of the health benefits exceeds the costs. Heart transplants seem to be too costly and only beneficial if patients are young.
-
Identification and ranking of environmental threats with ecosystem vulnerability distributions.
Zijp, Michiel C; Huijbregts, Mark A J; Schipper, Aafke M; Mulder, Christian; Posthuma, Leo
2017-08-24
Responses of ecosystems to human-induced stress vary in space and time, because both stressors and ecosystem vulnerabilities vary in space and time. Presently, ecosystem impact assessments mainly take into account variation in stressors, without considering variation in ecosystem vulnerability. We developed a method to address ecosystem vulnerability variation by quantifying ecosystem vulnerability distributions (EVDs) based on monitoring data of local species compositions and environmental conditions. The method incorporates spatial variation of both abiotic and biotic variables to quantify variation in responses among species and ecosystems. We show that EVDs can be derived based on a selection of locations, existing monitoring data and a selected impact boundary, and can be used in stressor identification and ranking for a region. A case study on Ohio's freshwater ecosystems, with freshwater fish as target species group, showed that physical habitat impairment and nutrient loads ranked highest as current stressors, with species losses higher than 5% for at least 6% of the locations. EVDs complement existing approaches of stressor assessment and management, which typically account only for variability in stressors, by accounting for variation in the vulnerability of the responding ecosystems.
-
Refining Southern California Geotherms Using Seismologic, Geologic, and Petrologic Constraints
NASA Astrophysics Data System (ADS)
Thatcher, W. R.; Chapman, D. S.; Allam, A. A.; Williams, C. F.
2017-12-01
Lithospheric deformation in tectonically active regions depends on the 3D distribution of rheology, which is in turn critically controlled by temperature. Under the auspices of the Southern California Earthquake Center (SCEC) we are developing a 3D Community Thermal Model (CTM) to constrain rheology and so better understand deformation processes within this complex but densely monitored and relatively well-understood region. The San Andreas transform system has sliced southern California into distinct blocks, each with characteristic lithologies, seismic velocities and thermal structures. Guided by the geometry of these blocks we use more than 250 surface heat-flow measurements to define 13 geographically distinct heat flow regions (HFRs). Model geotherms within each HFR are constrained by averages and variances of surface heat flow q0 and the 1D depth distribution of thermal conductivity (k) and radiogenic heat production (A), which are strongly dependent on rock type. Crustal lithologies are not always well known and we turn to seismic imaging for help. We interrogate the SCEC Community Velocity Model (CVM) to determine averages and variances of Vp, Vs and Vp/Vs versus depth within each HFR. We bound (A, k) versus depth by relying on empirical relations between seismic wave speed and rock type and laboratory and modeling methods relating (A, k) to rock type. Many 1D conductive geotherms for each HFR are allowed by the variances in surface heat flow and subsurface (A, k). An additional constraint on the lithosphere temperature field is provided by comparing lithosphere-asthenosphere boundary (LAB) depths identified seismologically with those defined thermally as the depth of onset of partial melting. Receiver function studies in Southern California indicate LAB depths that range from 40 km to 90 km. Shallow LAB depths are correlated with high surface heat flow and deep LAB with low heat flow. The much-restricted families of geotherms that intersect peridotite solidi at the seismological LAB depth in each region require that LAB temperatures lie between 1050 to 1250˚ C, a range that is consistent with a hydrous rather than anhydrous mantle below Southern California.
-
The effect of material heterogeneities in long term multiscale seismic cycle simulations
NASA Astrophysics Data System (ADS)
Kyriakopoulos, C.; Richards-Dinger, K. B.; Dieterich, J. H.
2016-12-01
A fundamental part of the simulation of the earthquake cycles in large-scale multicycle earthquake simulators is the pre-computation of elastostatic Greens functions collected into the stiffness matrix (K). The stiffness matrices are typically based on the elastostatic solutions of Okada (1992), Gimbutas et al. (2012), or similar. While these analytic solutions are computationally very fast, they are limited to modeling a homogeneous isotropic half-space. It is thus unknown how such simulations may be affected by material heterogeneity characterizing the earth medium. We are currently working on the estimation of the effects of heterogeneous material properties in the earthquake simulator RSQSim (Richards-Dinger and Dieterich, 2012). In order to do that we are calculating elastostatic solutions in a heterogeneous medium using the Finite Element (FE) method instead of any of the analytical solutions. The investigated region is a 400 x 400 km area centered on the Anza zone in southern California. The fault system geometry is based on that of the UCERF3 deformation models in the area of interest, which we then implement in a finite element mesh using Trelis 15. The heterogeneous elastic structure is based on available tomographic data (seismic wavespeeds and density) for the region (SCEC CVM and Allam et al., 2014). For computation of the Greens functions we are using the open source FE code Defmod (https://bitbucket.org/stali/defmod/wiki/Home) to calculate the elastostatic solutions due to unit slip on each patch. Earthquake slip on the fault plane is implemented through linear constraint equations (Ali et al., 2014, Kyriakopoulos et al., 2013, Aagard et al, 2015) and more specifically with the use of Lagrange multipliers adjunction. The elementary responses are collected into the "heterogeneous" stiffness matrix Khet and used in RSQSim instead of the ones generated with Okada. Finally, we compare the RSQSim results based on the "heterogeneous" Khet with results from Khom (stiffness matrix generated from the same mesh as Khet but using homogeneous material properties). The estimation of the effect of heterogeneous material properties in the seismic cycles simulated by RSQSim is a needed experiment that will allow us to evaluate the impact of heterogeneities in earthquake simulators.
-
Westwood, A; Bullock, D G; Whitehead, T P
1986-01-01
Hexokinase methods for serum glucose assay appeared to give slightly but consistently higher inter-laboratory coefficients of variation than all methods combined in the UK External Quality Assessment Scheme; their performance over a two-year period was therefore compared with that for three groups of glucose oxidase methods. This assessment showed no intrinsic inferiority in the hexokinase method. The greater variation may be due to the more heterogeneous group of instruments, particularly discrete analysers, on which the method is used. The Beckman Glucose Analyzer and Astra group (using a glucose oxidase method) showed the least inter-laboratory variability but also the lowest mean value. No comment is offered on the absolute accuracy of any of the methods.
-
Fast magnetic resonance imaging based on high degree total variation
NASA Astrophysics Data System (ADS)
Wang, Sujie; Lu, Liangliang; Zheng, Junbao; Jiang, Mingfeng
2018-04-01
In order to eliminating the artifacts and "staircase effect" of total variation in Compressive Sensing MRI, high degree total variation model is proposed for dynamic MRI reconstruction. the high degree total variation regularization term is used as a constraint to reconstruct the magnetic resonance image, and the iterative weighted MM algorithm is proposed to solve the convex optimization problem of the reconstructed MR image model, In addtion, one set of cardiac magnetic resonance data is used to verify the proposed algorithm for MRI. The results show that the high degree total variation method has a better reconstruction effect than the total variation and the total generalized variation, which can obtain higher reconstruction SNR and better structural similarity.
-
Two research studies funded and overseen by EPA have been conducted since October 2006 on soil gas sampling methods and variations in shallow soil gas concentrations with the purpose of improving our understanding of soil gas methods and data for vapor intrusion applications. Al...
-
2015-01-01
6. Zhang WG, Wilkin JL, Arango HG. Towards an integrated observation and modeling system in the New York Bight using variational methods. Part 1...1992;7:262- 72. ---- -- - ---------------------------- References 391 17. Rosmond TE, Teixeria J, Pcng M, Hogan TF, Pauley R. Navy operational global
-
Kyle J. Haynes; Andrew M. Liebhold; Ottar N. Bjørnstad; Andrew J. Allstadt; Randall S. Morin
2018-01-01
Evaluating the causes of spatial synchrony in population dynamics in nature is notoriously difficult due to a lack of data and appropriate statistical methods. Here, we use a recently developed method, a multivariate extension of the local indicators of spatial autocorrelation statistic, to map geographic variation in the synchrony of gypsy moth outbreaks. Regression...
-
ERIC Educational Resources Information Center
Cruzeiro, Vinícius Wilian D.; Roitberg, Adrian; Polfer, Nicolas C.
2016-01-01
In this work we are going to present how an interactive platform can be used as a powerful tool to allow students to better explore a foundational problem in quantum chemistry: the application of the variational method to the dihydrogen molecule using simple Gaussian trial functions. The theoretical approach for the hydrogen atom is quite…
-
NASA Technical Reports Server (NTRS)
Gao, Bo-Cai; Wiscombe, W. J.
1994-01-01
A method for detecting cirrus clouds in terms of brightness temperature differences between narrowbands at 8, 11, and 12 microns has been proposed by Ackerman et al. In this method, the variation of emissivity with wavelength for different surface targets was not taken into consideration. Based on state-of-the-art laboratory measurements of reflectance spectra of terrestrial materials by Salisbury and D'Aria, it is found that the brightness temperature differences between the 8- and 11-microns bands for soils, rocks, and minerals, and dry vegetation can vary between approximately -8 and +8 K due solely to surface emissivity variations. The large brightness temperature differences are sufficient to cause false detection of cirrus clouds from remote sensing data acquired over certain surface targets using the 8-11-12-microns method directly. It is suggested that the 8-11-12-microns method should be improved to include the surface emissivity effects. In addition, it is recommended that in the future the variation of surface emissivity with wavelength should be taken into account in algorithms for retrieving surface temperatures and low-level atmospheric temperature and water vapor profiles.
-
Variational approach to direct and inverse problems of atmospheric pollution studies
NASA Astrophysics Data System (ADS)
Penenko, Vladimir; Tsvetova, Elena; Penenko, Alexey
2016-04-01
We present the development of a variational approach for solving interrelated problems of atmospheric hydrodynamics and chemistry concerning air pollution transport and transformations. The proposed approach allows us to carry out complex studies of different-scale physical and chemical processes using the methods of direct and inverse modeling [1-3]. We formulate the problems of risk/vulnerability and uncertainty assessment, sensitivity studies, variational data assimilation procedures [4], etc. A computational technology of constructing consistent mathematical models and methods of their numerical implementation is based on the variational principle in the weak constraint formulation specifically designed to account for uncertainties in models and observations. Algorithms for direct and inverse modeling are designed with the use of global and local adjoint problems. Implementing the idea of adjoint integrating factors provides unconditionally monotone and stable discrete-analytic approximations for convection-diffusion-reaction problems [5,6]. The general framework is applied to the direct and inverse problems for the models of transport and transformation of pollutants in Siberian and Arctic regions. The work has been partially supported by the RFBR grant 14-01-00125 and RAS Presidium Program I.33P. References: 1. V. Penenko, A.Baklanov, E. Tsvetova and A. Mahura . Direct and inverse problems in a variational concept of environmental modeling //Pure and Applied Geoph.(2012) v.169: 447-465. 2. V. V. Penenko, E. A. Tsvetova, and A. V. Penenko Development of variational approach for direct and inverse problems of atmospheric hydrodynamics and chemistry, Izvestiya, Atmospheric and Oceanic Physics, 2015, Vol. 51, No. 3, p. 311-319, DOI: 10.1134/S0001433815030093. 3. V.V. Penenko, E.A. Tsvetova, A.V. Penenko. Methods based on the joint use of models and observational data in the framework of variational approach to forecasting weather and atmospheric composition quality// Russian meteorology and hydrology, V. 40, Issue: 6, Pages: 365-373, DOI: 10.3103/S1068373915060023. 4. A.V. Penenko and V.V. Penenko. Direct data assimilation method for convection-diffusion models based on splitting scheme. Computational technologies, 19(4):69-83, 2014. 5. V.V. Penenko, E.A. Tsvetova, A.V. Penenko Variational approach and Euler's integrating factors for environmental studies// Computers and Mathematics with Applications, 2014, V.67, Issue 12, Pages 2240-2256, DOI:10.1016/j.camwa.2014.04.004 6. V.V. Penenko, E.A. Tsvetova. Variational methods of constructing monotone approximations for atmospheric chemistry models // Numerical analysis and applications, 2013, V. 6, Issue 3, pp 210-220, DOI 10.1134/S199542391303004X
-
Satellite and Model Analysis of the Atmospheric Moisture Budget in High Latitudes
NASA Technical Reports Server (NTRS)
Bromwich, David H.; Chen, Qui-Shi
2001-01-01
In order to understand variations of accumulation over Greenland, it is necessary to investigate precipitation and its variations. Observations of precipitation over Greenland are limited and generally inaccurate, but the analyzed wind, geopotential height, and moisture fields are available for recent years. The objective of this study is to enhance the dynamic method for retrieving high resolution precipitation over Greenland from the analyzed fields. The dynamic method enhanced in this study is referred to as the improved dynamic method.
-
Blekhman, Ran; Tang, Karen; Archie, Elizabeth A; Barreiro, Luis B; Johnson, Zachary P; Wilson, Mark E; Kohn, Jordan; Yuan, Michael L; Gesquiere, Laurence; Grieneisen, Laura E; Tung, Jenny
2016-08-16
Field studies of wild vertebrates are frequently associated with extensive collections of banked fecal samples-unique resources for understanding ecological, behavioral, and phylogenetic effects on the gut microbiome. However, we do not understand whether sample storage methods confound the ability to investigate interindividual variation in gut microbiome profiles. Here, we extend previous work on storage methods for gut microbiome samples by comparing immediate freezing, the gold standard of preservation, to three methods commonly used in vertebrate field studies: lyophilization, storage in ethanol, and storage in RNAlater. We found that the signature of individual identity consistently outweighed storage effects: alpha diversity and beta diversity measures were significantly correlated across methods, and while samples often clustered by donor, they never clustered by storage method. Provided that all analyzed samples are stored the same way, banked fecal samples therefore appear highly suitable for investigating variation in gut microbiota. Our results open the door to a much-expanded perspective on variation in the gut microbiome across species and ecological contexts.
-
Blankena, Roos; Kleinloog, Rachel; Verweij, Bon H.; van Ooij, Pim; ten Haken, Bennie; Luijten, Peter R.; Rinkel, Gabriel J.E.; Zwanenburg, Jaco J.M.
2016-01-01
Purpose To develop a method for semi-quantitative wall thickness assessment on in vivo 7.0 tesla (7T) MRI images of intracranial aneurysms for studying the relation between apparent aneurysm wall thickness and wall shear stress. Materials and Methods Wall thickness was analyzed in 11 unruptured aneurysms in 9 patients, who underwent 7T MRI with a TSE based vessel wall sequence (0.8 mm isotropic resolution). A custom analysis program determined the in vivo aneurysm wall intensities, which were normalized to signal of nearby brain tissue and were used as measure for apparent wall thickness (AWT). Spatial wall thickness variation was determined as the interquartile range in AWT (the middle 50% of the AWT range). Wall shear stress was determined using phase contrast MRI (0.5 mm isotropic resolution). We performed visual and statistical comparisons (Pearson’s correlation) to study the relation between wall thickness and wall shear stress. Results 3D colored AWT maps of the aneurysms showed spatial AWT variation, which ranged from 0.07 to 0.53, with a mean variation of 0.22 (a variation of 1.0 roughly means a wall thickness variation of one voxel (0.8mm)). In all aneurysms, AWT was inversely related to WSS (mean correlation coefficient −0.35, P<0.05). Conclusions A method was developed to measure the wall thickness semi-quantitatively, using 7T MRI. An inverse correlation between wall shear stress and AWT was determined. In future studies, this non-invasive method can be used to assess spatial wall thickness variation in relation to pathophysiologic processes such as aneurysm growth and –rupture. PMID:26892986
-
Identification of structural variation in mouse genomes.
Keane, Thomas M; Wong, Kim; Adams, David J; Flint, Jonathan; Reymond, Alexandre; Yalcin, Binnaz
2014-01-01
Structural variation is variation in structure of DNA regions affecting DNA sequence length and/or orientation. It generally includes deletions, insertions, copy-number gains, inversions, and transposable elements. Traditionally, the identification of structural variation in genomes has been challenging. However, with the recent advances in high-throughput DNA sequencing and paired-end mapping (PEM) methods, the ability to identify structural variation and their respective association to human diseases has improved considerably. In this review, we describe our current knowledge of structural variation in the mouse, one of the prime model systems for studying human diseases and mammalian biology. We further present the evolutionary implications of structural variation on transposable elements. We conclude with future directions on the study of structural variation in mouse genomes that will increase our understanding of molecular architecture and functional consequences of structural variation.
-
Gupta, Munish; Kaplan, Heather C
2017-09-01
Quality improvement (QI) is based on measuring performance over time, and variation in data measured over time must be understood to guide change and make optimal improvements. Common cause variation is natural variation owing to factors inherent to any process; special cause variation is unnatural variation owing to external factors. Statistical process control methods, and particularly control charts, are robust tools for understanding data over time and identifying common and special cause variation. This review provides a practical introduction to the use of control charts in health care QI, with a focus on neonatology. Copyright © 2017 Elsevier Inc. All rights reserved.
-
Cox, Holly D; Eichner, Daniel
2017-09-19
The dried blood spot (DBS) matrix has significant utility for applications in the field where venous blood collection and timely shipment of labile blood samples is difficult. Unfortunately, protein measurement in DBS is hindered by high abundance proteins and matrix interference that increases with hematocrit. We developed a DBS method to enrich for membrane proteins and remove soluble proteins and matrix interference. Following a wash in a series of buffers, the membrane proteins are digested with trypsin and quantitated by parallel reaction monitoring mass spectrometry methods. The DBS method was applied to the quantification of four cell-specific cluster of differentiation (CD) proteins used to count cells by flow cytometry, band 3 (CD233), CD71, CD45, and CD41. We demonstrate that the DBS method counts low abundance cell types such as immature reticulocytes as well as high abundance cell types such as red blood cells, white blood cells, and platelets. When tested in 82 individuals, counts obtained by the DBS method demonstrated good agreement with flow cytometry and automated hematology analyzers. Importantly, the method allows longitudinal monitoring of CD protein concentration and calculation of interindividual variation which is difficult by other methods. Interindividual variation of band 3 and CD45 was low, 6 and 8%, respectively, while variation of CD41 and CD71 was higher, 18 and 78%, respectively. Longitudinal measurement of CD71 concentration in DBS over an 8-week period demonstrated intraindividual variation 17.1-38.7%. Thus, the method may allow stable longitudinal measurement of blood parameters currently monitored to detect blood doping practices.
-
Relevant Feature Set Estimation with a Knock-out Strategy and Random Forests
Ganz, Melanie; Greve, Douglas N.; Fischl, Bruce; Konukoglu, Ender
2015-01-01
Group analysis of neuroimaging data is a vital tool for identifying anatomical and functional variations related to diseases as well as normal biological processes. The analyses are often performed on a large number of highly correlated measurements using a relatively smaller number of samples. Despite the correlation structure, the most widely used approach is to analyze the data using univariate methods followed by post-hoc corrections that try to account for the data’s multivariate nature. Although widely used, this approach may fail to recover from the adverse effects of the initial analysis when local effects are not strong. Multivariate pattern analysis (MVPA) is a powerful alternative to the univariate approach for identifying relevant variations. Jointly analyzing all the measures, MVPA techniques can detect global effects even when individual local effects are too weak to detect with univariate analysis. Current approaches are successful in identifying variations that yield highly predictive and compact models. However, they suffer from lessened sensitivity and instabilities in identification of relevant variations. Furthermore, current methods’ user-defined parameters are often unintuitive and difficult to determine. In this article, we propose a novel MVPA method for group analysis of high-dimensional data that overcomes the drawbacks of the current techniques. Our approach explicitly aims to identify all relevant variations using a “knock-out” strategy and the Random Forest algorithm. In evaluations with synthetic datasets the proposed method achieved substantially higher sensitivity and accuracy than the state-of-the-art MVPA methods, and outperformed the univariate approach when the effect size is low. In experiments with real datasets the proposed method identified regions beyond the univariate approach, while other MVPA methods failed to replicate the univariate results. More importantly, in a reproducibility study with the well-known ADNI dataset the proposed method yielded higher stability and power than the univariate approach. PMID:26272728
-
NASA Astrophysics Data System (ADS)
Jin, Seung-Seop; Jung, Hyung-Jo
2014-03-01
It is well known that the dynamic properties of a structure such as natural frequencies depend not only on damage but also on environmental condition (e.g., temperature). The variation in dynamic characteristics of a structure due to environmental condition may mask damage of the structure. Without taking the change of environmental condition into account, false-positive or false-negative damage diagnosis may occur so that structural health monitoring becomes unreliable. In order to address this problem, an approach to construct a regression model based on structural responses considering environmental factors has been usually used by many researchers. The key to success of this approach is the formulation between the input and output variables of the regression model to take into account the environmental variations. However, it is quite challenging to determine proper environmental variables and measurement locations in advance for fully representing the relationship between the structural responses and the environmental variations. One alternative (i.e., novelty detection) is to remove the variations caused by environmental factors from the structural responses by using multivariate statistical analysis (e.g., principal component analysis (PCA), factor analysis, etc.). The success of this method is deeply depending on the accuracy of the description of normal condition. Generally, there is no prior information on normal condition during data acquisition, so that the normal condition is determined by subjective perspective with human-intervention. The proposed method is a novel adaptive multivariate statistical analysis for monitoring of structural damage detection under environmental change. One advantage of this method is the ability of a generative learning to capture the intrinsic characteristics of the normal condition. The proposed method is tested on numerically simulated data for a range of noise in measurement under environmental variation. A comparative study with conventional methods (i.e., fixed reference scheme) demonstrates the superior performance of the proposed method for structural damage detection.
-
On some variational acceleration techniques and related methods for local refinement
NASA Astrophysics Data System (ADS)
Teigland, Rune
1998-10-01
This paper shows that the well-known variational acceleration method described by Wachspress (E. Wachspress, Iterative Solution of Elliptic Systems and Applications to the Neutron Diffusion Equations of Reactor Physics, Prentice-Hall, Englewood Cliffs, NJ, 1966) and later generalized to multilevels (known as the additive correction multigrid method (B.R Huthchinson and G.D. Raithby, Numer. Heat Transf., 9, 511-537 (1986))) is similar to the FAC method of McCormick and Thomas (S.F McCormick and J.W. Thomas, Math. Comput., 46, 439-456 (1986)) and related multilevel methods. The performance of the method is demonstrated for some simple model problems using local refinement and suggestions for improving the performance of the method are given.
-
Thickness and resistivity variations over the upper surface of the human skull.
Law, S K
1993-01-01
A study of skull thickness and resistivity variations over the upper surface was made for an adult human skull. Physical measurements of thickness and qualitative analysis of photographs and CT scans of the skull were performed to determine internal and external features of the skull. Resistivity measurements were made using the four-electrode method and ranged from 1360 to 21400 Ohm-cm with an overall mean of 7560 +/- 4130 Ohm-cm. The presence of sutures was found to decrease resistivity substantially. The absence of cancellous bone was found to increase resistivity, particularly for samples from the temporal bone. An inverse relationship between skull thickness and resistivity was determined for trilayer bone (n = 12, p < 0.001). The results suggest that the skull cannot be considered a uniform layer and that local resistivity variations should be incorporated into realistic geometric and resistive head models to improve resolution in EEG. Influences of these variations on head models, methods for determining these variations, and incorporation into realistic head models, are discussed.
-
NASA Technical Reports Server (NTRS)
Achtemeier, Gary L.
1991-01-01
The second step in development of MODEL III is summarized. It combines the four radiative transfer equations of the first step with the equations for a geostrophic and hydrostatic atmosphere. This step is intended to bring radiance into a three dimensional balance with wind, height, and temperature. The use of the geostrophic approximation in place of the full set of primitive equations allows for an easier evaluation of how the inclusion of the radiative transfer equation increases the complexity of the variational equations. Seven different variational formulations were developed for geostrophic, hydrostatic, and radiative transfer equations. The first derivation was too complex to yield solutions that were physically meaningful. For the remaining six derivations, the variational method gave the same physical interpretation (the observed brightness temperatures could provide no meaningful input to a geostrophic, hydrostatic balance) at least through the problem solving methodology used in these studies. The variational method is presented and the Euler-Lagrange equations rederived for the geostrophic, hydrostatic, and radiative transfer equations.
-
Mechanism of lubrication by tricresylphosphate (TCP)
NASA Technical Reports Server (NTRS)
Faut, O. D.; Wheeler, D. R.
1983-01-01
A pin-on-disk tribometer equipped with an induction heater was used to study the coefficient of friction as a function of temperature for tricresylphosphate (TCP) on continuous vacuum melted (CVM) M-50 tool steel when the TCP was present in a liquid reservoir (bulk lubrication), and when it was applied as a liquid layer directly to the disk (limited lubrication). Under limited lubrication conditions, experiments were performed in dry ( 100 ppm H2O) air, dry ( 20 ppm H2O) nitrogen, dry nitrogen with the disks heated to 700 C then cooled to room temperature before the TCP was applied and the measurements made (preheated disks), and moist nitrogen using preheated disks. When the coefficient of friction was plotted as a function of the disk temperature, the friction decreased at a characteristic temperature, T sub r whose observed values were 265 C for bulk lubrication conditions in dry air, 225 C for limited lubrication conditions in dry air, and 215 C for limited lubrication conditions in dry nitrogen. No decrease in friction was observed with preheated disks; instead a sharp failure temperature was observed at 218 C, which was taken as the temperature about which the behavior of TCP should be judged, X-ray photoelectron spectroscopy confirmed the presence of phosphate on the surface of the iron pins used in the tribometer under TCP lubrication. Depth profile studies support the idea that a chemical reaction occurs between the TCP and the metal surface at T sub r.
-
Fish, Richard E; Griffith, Emily H
2014-01-01
Careers in Veterinary Medicine is a required, one-credit-hour course at the North Carolina State University College of Veterinary Medicine (NCSU-CVM), which meets once weekly during veterinary students' first semester. Lectures in this course are presented by one or more veterinarians representing diverse career areas. A voluntary, anonymous survey was distributed before the first class meeting in 2011 (PRE) and at the end of the semester (POST) to assess if students' career interests changed during the semester. The survey collected basic demographic data and students' preferences (on a Likert scale) for 17 veterinary career paths. Out of 63 students, 36 (57%) in the POST survey said that their career interests had changed during the semester, and 17 of the 26 students (65%) who gave a reason credited the careers course as one factor in reconsidering their career choice. Only 3 of the 17 career paths had statistically significant PRE/POST survey differences in Likert response frequency (equine practice, pathology, and wildlife medicine), but both informal discussions with students and responses to open-ended survey questions indicated that many students valued the introduction to unfamiliar veterinary career areas. Careers in Veterinary Medicine is a vital component of recent career-planning initiatives in the college, which will be especially important to veterinary students as they face continued changes in the profession, such as the increased debt load of the new graduate and the threat of veterinary workforce oversupply.
-
Smith, Amanda L.; Benazzi, Stefano; Ledogar, Justin A.; Tamvada, Kelli; Smith, Leslie C. Pryor; Weber, Gerhard W.; Spencer, Mark A.; Dechow, Paul C.; Grosse, Ian R.; Ross, Callum F.; Richmond, Brian G.; Wright, Barth W.; Wang, Qian; Byron, Craig; Slice, Dennis E.; Strait, David S.
2014-01-01
In a broad range of evolutionary studies, an understanding of intraspecific variation is needed in order to contextualize and interpret the meaning of variation between species. However, mechanical analyses of primate crania using experimental or modeling methods typically encounter logistical constraints that force them to rely on data gathered from only one or a few individuals. This results in a lack of knowledge concerning the mechanical significance of intraspecific shape variation that limits our ability to infer the significance of interspecific differences. This study uses geometric morphometric methods (GM) and finite element analysis (FEA) to examine the biomechanical implications of shape variation in chimpanzee crania, thereby providing a comparative context in which to interpret shape-related mechanical variation between hominin species. Six finite element models (FEMs) of chimpanzee crania were constructed from CT scans following shape-space Principal Component Analysis (PCA) of a matrix of 709 Procrustes coordinates (digitized onto 21 specimens) to identify the individuals at the extremes of the first three principal components. The FEMs were assigned the material properties of bone and were loaded and constrained to simulate maximal bites on the P3 and M2. Resulting strains indicate that intraspecific cranial variation in morphology is associated with quantitatively high levels of variation in strain magnitudes, but qualitatively little variation in the distribution of strain concentrations. Thus, interspecific comparisons should include considerations of the spatial patterning of strains rather than focus only their magnitude. PMID:25529239
-
Vertical Bridgman growth of Hg 1-xMn xTe with variational withdrawal rate
NASA Astrophysics Data System (ADS)
Zhi, Gu; Wan-Qi, Jie; Guo-Qiang, Li; Long, Zhang
2004-09-01
Based on the solute redistribution models, Vertical Bridgman growth of Hg1-xMnxTe with variational withdrawal rate is studied. Both theoretical analysis and experimental results show that the axial composition uniformity is improved and the crystal growth rate is also increased at the optimized variational method of withdrawal rate.
-
Isogeometric Divergence-conforming B-splines for the Steady Navier-Stokes Equations
2012-04-01
discretizations produce pointwise divergence-free velocity elds and hence exactly satisfy mass conservation. Consequently, discrete variational formulations...cretizations produce pointwise divergence-free velocity fields and hence exactly satisfy mass conservation. Consequently, discrete variational ... variational formulation. Using a combination of an advective for- mulation, SUPG, PSPG, and grad-div stabilization, provably convergent numerical methods
-
Measurement and Socio-Demographic Variation of Social Capital in a Large Population-Based Survey
ERIC Educational Resources Information Center
Nieminen, Tarja; Martelin, Tuija; Koskinen, Seppo; Simpura, Jussi; Alanen, Erkki; Harkanen, Tommi; Aromaa, Arpo
2008-01-01
Objectives: The main objective of this study was to describe the variation of individual social capital according to socio-demographic factors, and to develop a suitable way to measure social capital for this purpose. The similarity of socio-demographic variation between the genders was also assessed. Data and methods: The study applied…
-
BayesPI-BAR: a new biophysical model for characterization of regulatory sequence variations
Wang, Junbai; Batmanov, Kirill
2015-01-01
Sequence variations in regulatory DNA regions are known to cause functionally important consequences for gene expression. DNA sequence variations may have an essential role in determining phenotypes and may be linked to disease; however, their identification through analysis of massive genome-wide sequencing data is a great challenge. In this work, a new computational pipeline, a Bayesian method for protein–DNA interaction with binding affinity ranking (BayesPI-BAR), is proposed for quantifying the effect of sequence variations on protein binding. BayesPI-BAR uses biophysical modeling of protein–DNA interactions to predict single nucleotide polymorphisms (SNPs) that cause significant changes in the binding affinity of a regulatory region for transcription factors (TFs). The method includes two new parameters (TF chemical potentials or protein concentrations and direct TF binding targets) that are neglected by previous methods. The new method is verified on 67 known human regulatory SNPs, of which 47 (70%) have predicted true TFs ranked in the top 10. Importantly, the performance of BayesPI-BAR, which uses principal component analysis to integrate multiple predictions from various TF chemical potentials, is found to be better than that of existing programs, such as sTRAP and is-rSNP, when evaluated on the same SNPs. BayesPI-BAR is a publicly available tool and is able to carry out parallelized computation, which helps to investigate a large number of TFs or SNPs and to detect disease-associated regulatory sequence variations in the sea of genome-wide noncoding regions. PMID:26202972
-
Intra- and Inter-Fractional Variation Prediction of Lung Tumors Using Fuzzy Deep Learning
Park, Seonyeong; Lee, Suk Jin; Weiss, Elisabeth
2016-01-01
Tumor movements should be accurately predicted to improve delivery accuracy and reduce unnecessary radiation exposure to healthy tissue during radiotherapy. The tumor movements pertaining to respiration are divided into intra-fractional variation occurring in a single treatment session and inter-fractional variation arising between different sessions. Most studies of patients’ respiration movements deal with intra-fractional variation. Previous studies on inter-fractional variation are hardly mathematized and cannot predict movements well due to inconstant variation. Moreover, the computation time of the prediction should be reduced. To overcome these limitations, we propose a new predictor for intra- and inter-fractional data variation, called intra- and inter-fraction fuzzy deep learning (IIFDL), where FDL, equipped with breathing clustering, predicts the movement accurately and decreases the computation time. Through the experimental results, we validated that the IIFDL improved root-mean-square error (RMSE) by 29.98% and prediction overshoot by 70.93%, compared with existing methods. The results also showed that the IIFDL enhanced the average RMSE and overshoot by 59.73% and 83.27%, respectively. In addition, the average computation time of IIFDL was 1.54 ms for both intra- and inter-fractional variation, which was much smaller than the existing methods. Therefore, the proposed IIFDL might achieve real-time estimation as well as better tracking techniques in radiotherapy. PMID:27170914
-
Lisovskiĭ, A A; Pavlinov, I Ia
2008-01-01
Any morphospace is partitioned by the forms of group variation, its structure is described by a set of scalar (range, overlap) and vector (direction) characteristics. They are analyzed quantitatively for the sex and age variations in the sample of 200 skulls of the pine marten described by 14 measurable traits. Standard dispersion and variance components analyses are employed, accompanied with several resampling methods (randomization and bootstrep); effects of changes in the analysis design on results of the above methods are also considered. Maximum likelihood algorithm of variance components analysis is shown to give an adequate estimates of portions of particular forms of group variation within the overall disparity. It is quite stable in respect to changes of the analysis design and therefore could be used in the explorations of the real data with variously unbalanced designs. A new algorithm of estimation of co-directionality of particular forms of group variation within the overall disparity is elaborated, which includes angle measures between eigenvectors of covariation matrices of effects of group variations calculated by dispersion analysis. A null hypothesis of random portion of a given group variation could be tested by means of randomization of the respective grouping variable. A null hypothesis of equality of both portions and directionalities of different forms of group variation could be tested by means of the bootstrep procedure.
-
NASA Astrophysics Data System (ADS)
Huang, Wei; Chen, Xiu; Wang, Yueyun
2018-03-01
Landsat data are widely used in various earth observations, but the clouds interfere with the applications of the images. This paper proposes a weighted variational gradient-based fusion method (WVGBF) for high-fidelity thin cloud removal of Landsat images, which is an improvement of the variational gradient-based fusion (VGBF) method. The VGBF method integrates the gradient information from the reference band into visible bands of cloudy image to enable spatial details and remove thin clouds. The VGBF method utilizes the same gradient constraints to the entire image, which causes the color distortion in cloudless areas. In our method, a weight coefficient is introduced into the gradient approximation term to ensure the fidelity of image. The distribution of weight coefficient is related to the cloud thickness map. The map is built on Independence Component Analysis (ICA) by using multi-temporal Landsat images. Quantitatively, we use R value to evaluate the fidelity in the cloudless regions and metric Q to evaluate the clarity in the cloud areas. The experimental results indicate that the proposed method has the better ability to remove thin cloud and achieve high fidelity.
-
3D first-arrival traveltime tomography with modified total variation regularization
NASA Astrophysics Data System (ADS)
Jiang, Wenbin; Zhang, Jie
2018-02-01
Three-dimensional (3D) seismic surveys have become a major tool in the exploration and exploitation of hydrocarbons. 3D seismic first-arrival traveltime tomography is a robust method for near-surface velocity estimation. A common approach for stabilizing the ill-posed inverse problem is to apply Tikhonov regularization to the inversion. However, the Tikhonov regularization method recovers smooth local structures while blurring the sharp features in the model solution. We present a 3D first-arrival traveltime tomography method with modified total variation (MTV) regularization to preserve sharp velocity contrasts and improve the accuracy of velocity inversion. To solve the minimization problem of the new traveltime tomography method, we decouple the original optimization problem into two following subproblems: a standard traveltime tomography problem with the traditional Tikhonov regularization and a L2 total variation problem. We apply the conjugate gradient method and split-Bregman iterative method to solve these two subproblems, respectively. Our synthetic examples show that the new method produces higher resolution models than the conventional traveltime tomography with Tikhonov regularization. We apply the technique to field data. The stacking section shows significant improvements with static corrections from the MTV traveltime tomography.
-
Face landmark point tracking using LK pyramid optical flow
NASA Astrophysics Data System (ADS)
Zhang, Gang; Tang, Sikan; Li, Jiaquan
2018-04-01
LK pyramid optical flow is an effective method to implement object tracking in a video. It is used for face landmark point tracking in a video in the paper. The landmark points, i.e. outer corner of left eye, inner corner of left eye, inner corner of right eye, outer corner of right eye, tip of a nose, left corner of mouth, right corner of mouth, are considered. It is in the first frame that the landmark points are marked by hand. For subsequent frames, performance of tracking is analyzed. Two kinds of conditions are considered, i.e. single factors such as normalized case, pose variation and slowly moving, expression variation, illumination variation, occlusion, front face and rapidly moving, pose face and rapidly moving, and combination of the factors such as pose and illumination variation, pose and expression variation, pose variation and occlusion, illumination and expression variation, expression variation and occlusion. Global measures and local ones are introduced to evaluate performance of tracking under different factors or combination of the factors. The global measures contain the number of images aligned successfully, average alignment error, the number of images aligned before failure, and the local ones contain the number of images aligned successfully for components of a face, average alignment error for the components. To testify performance of tracking for face landmark points under different cases, tests are carried out for image sequences gathered by us. Results show that the LK pyramid optical flow method can implement face landmark point tracking under normalized case, expression variation, illumination variation which does not affect facial details, pose variation, and that different factors or combination of the factors have different effect on performance of alignment for different landmark points.