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Different Methodologies (different + methodology)
Selected AbstractsTrends and methodological impacts in soil CO2 efflux partitioning: A metaanalytical reviewGLOBAL CHANGE BIOLOGY, Issue 6 2006JENS-ARNE SUBKE Abstract Partitioning soil carbon dioxide (CO2) efflux (RS) into autotrophic (RA; including plant roots and closely associated organisms) and heterotrophic (RH) components has received considerable attention, as differential responses of these components to environmental change have profound implications for the soil and ecosystem C balance. The increasing number of partitioning studies allows a more detailed analysis of experimental constraints than was previously possible. We present results of an exhaustive literature search of partitioning studies and analyse global trends in flux partitioning between biomes and ecosystem types by means of a metaanalysis. Across all data, an overall decline in the RH/RS ratio for increasing annual RS fluxes emerged. For forest ecosystems, boreal coniferous sites showed significantly higher (P<0.05) RH/RS ratios than temperate sites, while both temperate or tropical deciduous forests did not differ in ratios from any of the other forest types. While chronosequence studies report consistent declines in the RH/RS ratio with age, no difference could be detected for different age groups in the global data set. Different methodologies showed generally good agreement if the range of RS under which they had been measured was considered, with the exception of studies estimating RH by means of root mass regressions against RS, which resulted in consistently lower RH/RS estimates out of all methods included. Additionally, the time step over which fluxes were partitioned did not affect RH/RS ratios consistently. To put results into context, we review the most common techniques and point out the likely sources of errors associated with them. In order to improve soil CO2 efflux partitioning in future experiments, we include methodological recommendations, and also highlight the potential interactions between soil components that may be overlooked as a consequence of the partitioning process itself. [source] An evolutionary optimization of diffuser shapes based on CFD simulationsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 10 2010S. Ghosh Abstract An efficient and robust algorithm is presented for the optimum design of plane symmetric diffusers handling incompressible turbulent flow. The indigenously developed algorithm uses the CFD software: Fluent for the hydrodynamic analysis and employs a genetic algorithm (GA) for optimization. For a prescribed inlet velocity and outlet pressure, pressure recovery coefficient C (the objective function) is estimated computationally for various design options. The CFD software and the GA have been combined in a monolithic platform for a fully automated operation using some special control commands. Based on the developed algorithm, an extensive exercise has been made to optimize the diffuser shape. Different methodologies have been adopted to create a large number of design options. Interestingly, not much difference has been noted in the optimum C values obtained through different approaches. However, in all the approaches, a better design has been obtained through a proper selection of the number of design variables. Finally, the effect of diffuser length on the optimum shape has also been studied. Copyright © 2009 John Wiley & Sons, Ltd. [source] Discovery of diagnostic serum biomarkers of gastric cancer using proteomicsPROTEOMICS - CLINICAL APPLICATIONS, Issue 2 2008Katie Wing-kei Lam Abstract Gastric cancer has significant morbidity and mortality worldwide and locally. Good prognosis relies on an early diagnosis. However, this remains a challenge due to the lack of specific and sensitive serum biomarkers for early detection. Hence, there is a constant search for these biomarkers for screening purposes. Proteomic profiling enables a new approach to the discovery of biomarkers in disease. This review presents recent attempts in search of gastric cancer serum biomarker using proteomics. Different methodologies and different types of samples were employed by different groups of researchers. Major difficulties were encountered in the discovery processes, including interference from abundant proteins and continuous changing serum proteomes from different individuals. [source] Potential Errors in Detecting Earnings Management: Reexamining Studies Investigating the AMT of 1986,CONTEMPORARY ACCOUNTING RESEARCH, Issue 4 2001Won W. Choi Abstract In this paper we seek to document errors that could affect studies of earnings management. The book income adjustment (BIA) of the alternative minimum tax (AMT) created apparently strong incentives to manage book income downward in 1987. Five earlier papers using different methodologies and samples all conclude that earnings were reduced in response to the BIA. This consensus of findings offers an opportunity to investigate our speculation that methodological biases are more likely when there appear to be clear incentives for earnings management. A reexamination of these studies uncovers potential biases related to a variety of factors, including choices of scaling variables, selection of affected and control samples, and measurement error in estimated discretionary accruals. A reexamination of the argument underlying these studies also suggests that the incentives to manage earnings are less powerful than initially predicted, and are partially mitigated by tax and non-tax factors. As a result, we believe that the extent of earnings management that occurred in 1987 in response to the BIA remains an unresolved issue. [source] Subacute sclerosing panencephalitis: an updateDEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 10 2010JOSE GUTIERREZ Subacute sclerosing panencephalitis (SSPE) is a chronic encephalitis occurring after infection with measles virus. The prevalence of the disease varies depending on uptake of measles vaccination, with the virus disproportionally affecting regions with low vaccination rates. The physiopathology of the disease is not fully understood; however, there is evidence that it involves factors that favour humoral over cellular immune response against the virus. As a result, the virus is able to infect the neurons and to survive in a latent form for years. The clinical manifestations occur, on average, 6 years after measles virus infection. The onset of SSPE is insidious, and psychiatric manifestations are prominent. Subsequently, myoclonic seizures usually lead to a final stage of akinetic mutism. The diagnosis is clinical, supported by periodic complexes on electroencephalography, brain imaging suggestive of demyelination, and immunological evidence of measles infection. Management of the disease includes seizure control and avoidance of secondary complications associated with the progressive disability. Trials of treatment with interferon, ribavirin, and isoprinosine using different methodologies have reported beneficial results. However, the disease shows relentless progression; only 5% of individuals with SSPE undergo spontaneous remission, with the remaining 95% dying within 5 years of diagnosis. [source] Cover Picture: Electrophoresis 1'2010ELECTROPHORESIS, Issue 1 2010Article first published online: 28 DEC 200 Issue no. 1 has 17 "comprehensive and critical reviews written by experts in the fields of CE and CEC. The six review articles in Part I provide an in-depth description of the latest developments in different methodologies and their applications, e.g. surface modification in microfluidics, determination of binding constants in CE, enhanced sensitivity in chiral CE, coupling SPE-CE, CE and MCE in microdialysis, and electrophoretically mediated microanalysis. Part II reviews CE and CEC of biomolecules such as amino acids, peptides and proteins. Part III is on recent progress made in inorganic species, food, antibiotics, and phytochemical analyses and forensic sciences." [source] Non-linear approaches for reducing large power systemsEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 3 2001X. Lei Issues on the establishment of equivalent networks are becoming essential for the deregulated power market. This paper presents a comprehensive tool for network reduction of large power systems. Through integrating different methodologies into a simulation program, the dynamic equivalent can be established by adopting one common database. With a readily integrated modified Gauss-Newton algorithm, network reduction can be executed under the dynamic conditions either in the time domain or in the frequency domain in coping with nonlinear nature of the system involved. Furthermore, a novel algorithm based on dynamic coherency approach implemented readily into the simulation program is also presented. This novel approach determines coherent generators on non-linear basis in the time domain using the cross correlation technique, taking dynamic characteristics of the system involved into consideration. Two case studies are presented in this paper. Each of the non-linear approaches presented is applied for one of the case studies as application example. The results achieved validate the functionality of the approaches presented. [source] Fish-based methods for assessing European running waters: a synthesisFISHERIES MANAGEMENT & ECOLOGY, Issue 6 2007S. SCHMUTZ Abstract, The European Union, Water Framework Directive (WFD) requires monitoring of riverine fish fauna. When the WFD came into force in 2000, most of the EU member states did not have fish-based assessment methods compliant to WFD requirements. Therefore, the objectives of FAME (http://fame.boku.ac.at), a project under the fifth R&D Framework Programme of the European Commission were to develop, evaluate and implement a standardised fish-based method for assessing the ecological status of European running waters. This paper synthesises the outputs of FAME and defines future research needs. Two different methodologies were used: the so-called spatially based modelling and the site-specific modelling, the latter leading to the European Fish Index (EFI). The advantage of the EFI is that, despite being a single index, it is applicable to a wide range of environmental conditions across Europe precluding the need for inter-calibration. The EFI will support the WFD towards harmonised/standardised assessment and management of running waters in Europe, thus enabling comparative analyses of the ecological status of running waters across Europe. [source] Comparison of different methodologies for CD4 estimation in a clinical settingHIV MEDICINE, Issue 4 2008S Jeganathan Objective To compare flow cytometry assays, using traditional dual platform (DP) or newer single platform (SP) for CD4 enumeration. Method Records of subjects enrolled in four separate clinical trials using the same central laboratory [SP methodology (Trucount)] were reviewed retrospectively. Eighteen subjects had 60 matching contemporaneous samples at multiple timepoints. Results DP flow cytometry yielded higher CD4 counts in 50/60 assays (83%). CD4 count and percentage by the two methods showed strong correlation for the counts (r=0.965, P<0.0001) and percentages (r=0.959, P<0.0001). Bland,Altman plot analysis showed that the limits of variation were within agreeable limits of ±2SD in 56/60 (93.3%) samples tested. Twenty-five (42%) samples had a difference of >50 cells/,L. Of these six (24%) exceeded 100 cells. Conclusion This study is in agreement with previous reports of strong correlation between DP and SP flow cytometry. This review found differences in CD4 counts in a high proportion of samples tested highlighting the importance for clinicians to be aware of such differences when interpreting results from the two methods. [source] A comparison of brain activation patterns during covert and overt paced auditory serial addition test tasksHUMAN BRAIN MAPPING, Issue 6 2008Cristina Forn Abstract The Paced Auditory Serial Addition test (PASAT) is a sensitive task for evaluating cognitive impairment in patients with diffuse brain disorders, such as multiple sclerosis patients. Brain areas involved in this task have been investigated in diverse fMRI studies using different methodologies to control the subjects' responses during scanning. Here, we examined the possible differences between overt and covert responses during the PASAT task in 13 volunteers. Results showed similar activations in parietal and frontal brain areas during both versions of the task. The contrast between the two conditions (overt and covert) indicated that differences in these two methodologies were minimal. Unlike the covert condition, the overt version of the task obtained significant activations in the left superior and inferior frontal gyrus, bilateral occipital cortex, caudate nucleus and cerebellum. As expected, no significant overactivations were observed in the covert when compared with the overt condition. Discussion focuses on the lower cost of using verbal responses to monitor performance during the PASAT task, which might be generalisable to other frontal lobe tasks requiring discrete responses. Hum Brain Mapp, 2008. © 2007 Wiley-Liss, Inc. [source] Onset of action of antidepressants: results of different analysesHUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue S1 2002Chris Thompson Abstract Because the value of antidepressants is hampered by their delay in onset of action, considerable attention has been focused on developing a drug that acts more rapidly. However, although specific studies are now ongoing, there have been no peer-reviewed prospective onset of action trials published in the literature to date. Some data are currently available from post-hoc pooled analyses and numerous methods have been developed for evaluating the onset of action; these include the time to response, the time to onset of therapeutic effect, pattern analysis and survival analyses. Such an analysis of four large-scale, double-blind studies has provided evidence for an earlier onset of action with mirtazapine than with the SSRIs (fluoxetine, paroxetine and citalopram). Significant differences were seen between mirtazapine and the SSRIs after 1 week of treatment. This effect was consistent across the four different methodologies and appears to be due to a specific antidepressant effect rather than an early effect on, for example, sleep. These findings await confirmation from specifically designed prospective onset of action studies. Copyright © 2002 John Wiley & Sons, Ltd. [source] Downscaling of global climate models for flood frequency analysis: where are we now?HYDROLOGICAL PROCESSES, Issue 6 2002Christel Prudhomme Abstract The issues of downscaling the results from global climate models (GCMs) to a scale relevant for hydrological impact studies are examined. GCM outputs, typically at a spatial resolution of around 3° latitude and 4° longitude, are currently not considered reliable at time scales shorter than 1 month. Continuous rainfall-runoff modelling for flood regime assessment requires input at the daily or even hourly time-step. A review of the different methodologies suggested in the literature to downscale GCM results at smaller spatial and temporal resolutions is presented. The methods, from simple interpolation to more sophisticated dynamical modelling, through multiple regression and weather generators, are, however, mostly based directly on GCM outputs, sometimes at daily time-step. The approach adopted is a simple, empirical methodology based on modelled monthly changes from the HadCM2 greenhouse gases experiment for the time horizon 2050s. Three daily rainfall scenarios are derived from the same set of monthly changes, representing different possible changes in the rainfall regime. The first scenario represents an increase of the occurrence of frontal systems, corresponding to a decrease in the rainfall intensity; the second corresponds to an increase in convective storm-type rainfall, characterized by extreme events with higher intensity; the third one assumes an increase in the monthly rainfall without any change in rainfall variability. A continuous daily rainfall-runoff model, calibrated for the Severn catchment, was used to generate daily flow series for the 1961,90 baseline period and the 2050s, and a peaks-over-threshold analysis was undertaken to produce flood frequency distributions for the two time horizons. Though the three scenarios lead to an increase in the magnitude and the frequency of the extreme flood events, the impact is strongly influenced by the type of daily rainfall scenario applied. We conclude that if the next generation of GCMs produce more reliable rainfall variance estimates, then more appropriate ways of deriving rainfall scenarios could be developed using weather generators rather than empirical methods. Copyright © 2002 John Wiley & Sons, Ltd. [source] Modelling small-business credit scoring by using logistic regression, neural networks and decision treesINTELLIGENT SYSTEMS IN ACCOUNTING, FINANCE & MANAGEMENT, Issue 3 2005Mirta Bensic Previous research on credit scoring that used statistical and intelligent methods was mostly focused on commercial and consumer lending. The main purpose of this paper is to extract important features for credit scoring in small-business lending on a dataset with specific transitional economic conditions using a relatively small dataset. To do this, we compare the accuracy of the best models extracted by different methodologies, such as logistic regression, neural networks (NNs), and CART decision trees. Four different NN algorithms are tested, including backpropagation, radial basis function network, probabilistic and learning vector quantization, by using the forward nonlinear variable selection strategy. Although the test of differences in proportion and McNemar's test do not show a statistically significant difference in the models tested, the probabilistic NN model produces the highest hit rate and the lowest type I error. According to the measures of association, the best NN model also shows the highest degree of association with the data, and it yields the lowest total relative cost of misclassification for all scenarios examined. The best model extracts a set of important features for small-business credit scoring for the observed sample, emphasizing credit programme characteristics, as well as entrepreneur's personal and business characteristics as the most important ones. Copyright © 2005 John Wiley & Sons, Ltd. [source] On the numerical treatment of initial strains in biological soft tissuesINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 8 2006E. Peña Abstract In this paper, different methodologies to enforce initial stresses or strains in finite strain problems are compared. Since our main interest relies on the simulation of living tissues, an orthotropic hyperelastic constitutive model has been used to describe their passive material behaviour. Different methods are presented and discussed. Firstly, the initial strain distribution is obtained after deformation from a previously assumed to be known stress-free state using an appropriate finite element approach. This approach usually involves important mesh distortions. The second method consists on imposing the initial strain field from the definition of an initial incompatible ,deformation gradient' field obtained from experimental data. This incompatible tensor field can be imposed in two ways, depending on the origin of the experimental tests. In some cases as ligaments, the experiment is carried out from the stress-free configuration, while in blood vessels the starting point is usually the load-free configuration with residual stresses. So the strain energy function would remain the same for the whole simulation or redefined from the new origin of the experiment. Some validation and realistic examples are presented to show the performance of the strategies and to quantify the errors appearing in each of them. Copyright © 2006 John Wiley & Sons, Ltd. [source] Cost structure of CGAM cogeneration systemINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 13 2004Ho-Young Kwak Abstract The cost structure of the CGAM system, a predefined cogeneration system suggested to unify the different methodologies of thermoeconomic analysis, was investigated by using a thermoeconomic method called modified productive structure analysis (MOPSA). An emphasis has been specially put on how the cost structure of the system is affected by the chosen level of aggregation that specifies the subsystems. It has been found that the unit cost of products is dependent on the chosen level of aggregation of the system only when one considers the entropy flow as one of the parameters to determine the unit cost of products. Copyright © 2004 John Wiley & Sons, Ltd. [source] Applying aggregation operators for information access systems: An application in digital librariesINTERNATIONAL JOURNAL OF INTELLIGENT SYSTEMS, Issue 12 2008Enrique Herrera-Viedma Nowadays, the information access on the Web is a main problem in the computer science community. Any major advance in the field of information access on the Web requires the collaboration of different methodologies and research areas. In this paper, the concept of aggregation operator playing a role for information access on the Web is analyzed. We present some Web methodologies, as search engines, recommender systems, and Web quality evaluation models and analyze the way aggregation operators help toward the success of their activities. We also show an application of the aggregation operators in digital libraries. In particular, we introduce a Web information system to analyze the quality of digital libraries that implements an important panel of aggregation operators to obtain the quality assessments. © 2008 Wiley Periodicals, Inc. [source] Confirmation of the presence of Mycobacterium tuberculosis complex-specific DNA in three archaeological specimensINTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 6 2002Mark Spigelman Abstract This journal published the first reported identification of Mycobacterium tuberculosis complex (MTB) DNA in ancient human remains but concerns were raised about the article two years after publication. These were based on methodology which, in the field of ancient DNA, was still developing. Here we present a re-examination of the 1993 research conducted on three specimens which exhibited palaeopathologies indicative of tuberculosis. The specimens were: an ulna from pre-European-contact Borneo, a spine from Byzantine Turkey, and a lumbar-sacral spine from 17th century Scotland. There was insufficient material to permit re-examination of all of the original samples. The earlier results were confirmed in two independent laboratories using different methodologies. MTB DNA complex-specific DNA amplicons were obtained, and sequenced in both laboratories, in a re-analysis of samples which supported the earlier findings. Copyright © 2002 John Wiley & Sons, Ltd. [source] Nanofilled polyethersulfone as matrix for continuous glass fibers composites: Mechanical properties and solvent resistance,ADVANCES IN POLYMER TECHNOLOGY, Issue 3 2010M. Aurilia Abstract Polyethersulfone (PES) is high performance thermoplastic polymer; however, its applications are limited by the poor resistance to several classes of solvents. Fumed silica and expanded graphite nanoparticles were used to prepare nanofilled PES by a melt-compounding technique with the view to improve the barrier properties. Solvent uptake at equilibrium and solvents resistance of nanofilled PES compounds were investigated by three different methodologies: (1) weight increase by methylene chloride absorption in a vapor-saturated atmosphere, (2) solvent uptake of acetone at equilibrium, and (3) decay of storage modulus induced by acetone diffusion. The storage modulus decay was measured by means of dynamic mechanical analysis on samples immersed in an acetone bath. The collected data were fitted to an ad hoc model to calculate the diffusion coefficient. The produced nanofilled PES showed a significant improvement in barrier properties and considerable reduction in acetone uptake at equilibrium, in comparison with the neat PES. Nanofilled PES compounds were also used to produce continuous glass fiber composites by the film-stacking manufacturing technique. The composites exhibited, by and large, improvements in flexural and shear strength. Their solvent resistance was evaluated by measuring the variation of mechanical properties after exposure to acetone for 1 and 5 days. These tests showed that the composites produced with the nanocomposite matrix did not exhibit higher solvent resistance than those prepared with neat PES, probably because of the deterioration of the fiber/nanocomposite-matrix interfacial bond in the wet state. © 2010 Wiley Periodicals, Inc. Adv Polym Techn 29:146,160, 2010; View this article online at wileyonlinelibrary. DOI 10.1002/adv.20187 [source] A review of the factors involved in older people's decision making with regard to influenza vaccination: a literature reviewJOURNAL OF CLINICAL NURSING, Issue 1 2008Leigh Ward BSc Aims and objectives., The aim of this paper was to develop an understanding of the factors involved in older people's decision making with regard to influenza vaccination to inform strategies to improve vaccine uptake and reduce morbidity and mortality. Background., Influenza is a major cause of morbidity and mortality world-wide. In the UK, it accounts for 3000,6000 deaths annually; 85% of these deaths are people aged 65 and over. Despite this, and the widespread and costly annual government campaigns, some older people at risk of influenza and the associated complications remain reluctant to take advantage of the offer of vaccination. Methods., A review of the English language literature referring to older people published between 1996 and 2005 was the method used. Inclusion and exclusion criteria were identified and applied. Results., The majority of the literature was quantitative in nature, investigating personal characteristics thought to be predictors of uptake, such as age, sex, co-morbidity, educational level, income and area of residence. However, there was little discussion of the possible reasons for the significance of these factors and conflict between findings was often evident, particularly between studies employing different methodologies. Other factors identified were prior experience, concerns about the vaccine, perceived risk and advice and information. Relevance to clinical practice., The wealth of demographic information available will be useful at a strategic level in targeting groups identified as being unlikely to accept vaccination. However, the promotion of person-centred ways of working that value the health beliefs, attitudes, perceptions and subjective experiences of older people is likely to be more successful during individual encounters designed to promote acceptance. Without more research in investigating these concepts, our understanding is inevitably limited. [source] Different hip and knee priority score systems: are they good for the same thing?JOURNAL OF EVALUATION IN CLINICAL PRACTICE, Issue 5 2010Antonio Escobar MD PhD Abstract Objective, The aim of the present study was to compare two priority tools used for joint replacement for patients on waiting lists, which use two different methods. Methods, Two prioritization tools developed and validated by different methodologies were used on the same cohort of patients. The first, an IRYSS hip and knee priority score (IHKPS) developed by RAND method, was applied while patients were on the waiting list. The other, a Catalonia hip,knee priority score (CHKPS) developed by conjoint analysis, was adapted and applied retrospectively. In addition, all patients fulfilled pre-intervention the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Correlation between them was studied by Pearson correlation coefficient (r). Agreement was analysed by means of intra-class correlation coefficient (ICC), Kendall coefficient and Cohern kappa. The relationship between IHKPS, CHKPS and baseline WOMAC scores by r coefficient was studied. Results, The sample consisted of 774 consecutive patients. Pearson correlation coefficient between IHKPS and CHKPS was 0.79. The agreement study showed that ICC was 0.74, Kendall coefficient 0.86 and kappa 0.66. Finally, correlation between CHKPS and baseline WOMAC ranged from 0.43 to 0.64. The results according to the relationship between IHKPS and WOMAC ranged from 0.50 to 0.74. Conclusions, Results support the hypothesis that if the final objective of the prioritization tools is to organize and sort patients on the waiting list, although they use different methodologies, the results are similar. [source] Liver disease and the renin,angiotensin system: Recent discoveries and clinical implicationsJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 9 2008John S Lubel Abstract The renin,angiotensin system (RAS) is a key regulator of vascular resistance, sodium and water homeostasis and the response to tissue injury. Historically, angiotensin II (Ang II) was thought to be the primary effector peptide of this system. Ang II is produced predominantly by the effect of angiotensin converting enzyme (ACE) on angiotensin I (Ang I). Ang II acts mainly through the angiotensin II type-1 receptor (AT1) and, together with ACE, these components represent the ,classical' axis of the RAS. Drug therapies targeting the RAS by inhibiting Ang II formation (ACE inhibitors) or binding to its receptor (angiotensin receptor blockers) are now in widespread clinical use and have been shown to reduce tissue injury and fibrosis in cardiac and renal disease independently of their effects on blood pressure. In 2000, two groups using different methodologies identified a homolog of ACE, called ACE2, which cleaves Ang II to form the biologically active heptapeptide, Ang-(1,7). Conceptually, ACE2, Ang-(1,7), and its putative receptor, the mas receptor represent an ,alternative' axis of the RAS capable of opposing the often deleterious actions of Ang II. Interestingly, ACE inhibitors and angiotensin receptor blockers increase Ang-(1,7) production and it has been proposed that some of the beneficial effects of these drugs are mediated through upregulation of Ang-(1,7) rather than inhibition of Ang II production or receptor binding. The present review focuses on the novel components and pathways of the RAS with particular reference to their potential contribution towards the pathophysiology of liver disease. [source] The Well-Being of Children Born to Teen MothersJOURNAL OF MARRIAGE AND FAMILY, Issue 1 2007Judith A. Levine Children born to early child bearers are more likely than other children to display problem behaviors or poor academic performance, but it is unclear whether early childbearing plays a causal role in these outcomes. Using multiple techniques to control for background factors, we analyze 2,908 young children and 1,736 adolescents and young adults in the National Longitudinal Survey of Youth (NLSY79) and the NLSY79 Children and Young Adults (CNLSY79) data sets to examine whether early childbearing causes children's outcomes. We find evidence that teen childbearing plays no causal role in children's test scores and in some behavioral outcomes of adolescents. For other behavioral outcomes, we find that different methodologies produce differing results. We thus suggest caution in drawing conclusions about early parenthood's overarching effect. [source] Determination of the In Vitro Susceptibility of Feline Tritrichomonas foetus to 5 Antimicrobial AgentsJOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 5 2007Elizabeth J. Kather Background: The nitroimidazole, ronidazole, has been demonstrated to have in vitro and in vivo activity against the protozoan Tritrichomonas foetus in cats. The purpose of this study was to evaluate the in vitro susceptibility of feline T foetus isolates obtained from naturally infected cats to 5 antimicrobial agents and to compare the in vitro time kill of ronidazole and metronidazole. Hypothesis: We hypothesized that nitroimidazoles have in vitro activity against T foetus, whereas furazolidone, omeprazole, and paromomycin do not. Animals: Fecal specimens were cultured from 4 naturally infected Bengal cats with a history of T foetus -associated diarrhea. Methods: A 24-hour susceptibility assay was performed on all 4 isolates for the 5 antimicrobial agents. A time-kill microdilution method was performed on 2 isolates for metronidazole and ronidazole. Results: Paromomycin and omeprazole showed no in vitro effect at concentrations ±80 ,g/mL. There was no significant difference in 24-hour susceptibilities among metronidazole, ronidazole, and furazolidone. In addition, only the results of the highest concentration tested (80 ,g/mL) and concentrations of 1.25 and 2.5 ,g/mL revealed significant differences in the rate of trophozoite killing, with ronidazole having a faster reduction in trophozoite survival. Conclusions and Clinical Importance: Time-kill assays demonstrated ronidazole had a higher lethal activity compared with metronidazole. These findings contrast with a previously published report and may reflect strain variation, different methodologies, or both. The lack of clinical response seen with metronidazole administration to treat feline trichomoniasis may not reflect inherent resistance but rather in vivo events involving drug distribution and pharmacokinetics. [source] In vitro fungitoxic activity of Larrea divaricata cav. extractsLETTERS IN APPLIED MICROBIOLOGY, Issue 1 2004E.N. Quiroga Abstract Aims:, To evaluate the fungitoxic activity of Larrea divaricata Cav. extract and one of its components against yeasts and fungi. This activity was compared with the action of ketoconazole, a known synthetic antimycotic. Methods and Results:, Antifungal activity of Larrea divaricata extract and of a fraction (Fr. B) purified by thin layer chromatography, was investigated using different methodologies. Both exhibited strong activity against the majority of the assayed fungi. Only Fusarium oxysporum and Schizophyllum commune growth was not affected with the assayed conditions. The fungitoxic and cytotoxic activity of the ethanolic extract and ketoconazole were compared. Conclusions:, Ethanolic extracts of L. divaricata Cav. produce growth inhibition of several fungi. One of its constituents with the same activity was purified and identified as a glycoside of a flavanone. A comparison with the action of ketoconazole, which is currently used as antimycotic and can cause adverse health effects was made. Significance and Impact of the Study:, Our data suggest that L. divaricata extract contains, at least, one compound of phenolic nature, with fungitoxic potency against yeasts and fungi. [source] A set of primers for amplification of mitochondrial DNA in Picea abies and other conifer speciesMOLECULAR ECOLOGY RESOURCES, Issue 4 2002S. Jeandroz Abstract Thirteen primer pairs generating intraspecific length and/or presence-absence polymorphism in Picea abies have been obtained from a P. abies mtDNA library, using different methodologies (agarose gel electrophoresis, polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), single-strand conformation (SSCP). Poly-morphism tests were extended successfully to other Picea species (P. omorika, P. engelmanii and P. glauca) and species belonging to other conifer genera (Abies alba, Larix laricina and Pinus pinaster). This set of PCR-based mitochondrial markers can provide promising tools for studying phylogeography or phylogeny in P. abies and other conifer species in which the mt genome is generally the only one to be transmitted via the female gamete. [source] Salivary cortisol and psychosocial hazards at workAMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 3 2009Giovanni Maina MD Abstract Background Experimental and clinical evidence suggest that stress can lead to ill-health through the disregulation of the hypothalamic,pituitary,adrenal (HPA) axis. Studies to date have produced equivocal results likely due to different methodologies and failure to account for confounding factors. This investigation aimed to assess the relation between self-reported work-related stressors and salivary cortisol and to clarify the role of the potential confounders. Methods Thirty-six call-handlers completed a self-administered job content questionnaire and collected seven daily salivary samples on two workdays and a weekend. The diurnal salivary cortisol output was expressed as cortisol awakening response (CAR), and cortisol output in the rest of the day. Salivary cortisol data were normalized by means of square root transformation. The generalized estimating equations method was used to assess the relation between job strain and cortisol levels after adjusting for gender, weekdays and adherence to the sampling schedule. Results Job strain significantly influenced the total amount of cortisol response to waking (high strain vs. low strain: 1.1 (0.3,2.0) nmol/L). The cortisol response to waking showed gender-specific differences [women excreting greater cortisol than men: 1.1 (0.3,1.9) nmol/L], and weekday differences [workdays vs. weekend: 1.0 (0.3,1.6) nmol/L]. Non-compliance with the sampling protocol was associated with lower salivary cortisol than in adherent subjects. Conclusions Our results provide further evidence for the HPA axis involvement in the physiological response to work stress. The measure of the CAR showed to be the sensitive index to assess the physiological response to psychosocial factors. Gender, weekday, and protocol compliance were confounding factors. Am. J. Ind. Med. 52:251,260, 2009. © 2008 Wiley-Liss, Inc. [source] Exploring the proteome of meningococcal outer membrane vesicle vaccinesPROTEOMICS - CLINICAL APPLICATIONS, Issue 9 2007Jun X. Wheeler Dr. Abstract Neisseria meningitidis, one of the principal causes of bacterial meningitis and septicemia, continues to present a challenge for vaccine developers. While significant progress has been made in the development and implementation of conjugate vaccines, which are based on the capsular polysaccharide of the organism, this approach has failed to produce a vaccine against organisms expressing a serogroup B capsule. The completion of the first meningococcal genome sequences in 2000 provided new ways of meeting this challenge. One approach has been to learn more about meningococcal biology and pathogenesis through exploring its proteome. This article reviews the results of ten recent studies of the meningococcal proteome and compares the different methodologies employed. Not surprisingly, given the renewed impetus to develop a comprehensive vaccine and the continuing clinical development of outer membrane vesicle vaccines, many of these studies focus on the proteome of the outer membrane fraction. As in other areas of proteome research, the direct comparison of data from different studies is hampered by the lack of standardization of separation technologies and data formats. Nevertheless, proteomic analysis, especially when combined with detailed knowledge of meningococcal population structures, represents a powerful tool in the development of vaccines against this important pathogen. [source] Research Review: The relationship between childhood violence exposure and juvenile antisocial behavior: a meta-analytic reviewTHE JOURNAL OF CHILD PSYCHOLOGY AND PSYCHIATRY AND ALLIED DISCIPLINES, Issue 7 2009Helen W. Wilson Background:, The connection between childhood violence exposure and antisocial behavior in adolescence has received much attention and has important implications for understanding and preventing criminal behavior. However, there are a limited number of well-designed prospective studies that can suggest a causal relationship, and little is known about the magnitude of the relationship. Methods:, This meta-analysis provides a quantitative comparison of 18 studies (N = 18,245) assessing the relationship between childhood (before age 12) violence exposure and adolescent antisocial behavior. An overall effect size (Cohen's d) was calculated for each study, an average for the 18 studies, and averages for subsets of analyses within studies. Results:, Results indicated a small effect from prospective studies (d = .31) and a large effect from cross-sectional studies (d = .88). The effect for victimization (d = .61) was larger than for witnessing violence (d = .15). Conclusions:, Effect size varied across studies employing different methodologies, populations, and conceptualizations of violence exposure and antisocial behavior. These findings do not support a simple, direct link from early violence exposure to antisocial behavior but suggest that many factors influence this relationship. [source] Rolling over stock index futures contractsTHE JOURNAL OF FUTURES MARKETS, Issue 7 2009Óscar Carchano Derivative contracts have a finite life limited by their maturity. The construction of continuous series, however, is crucial for academic and trading purposes. In this study, we analyze the relevance of the choice of the rollover date, defined as the point in time when we switch from the front contract series to the next one. We have used five different methodologies in order to construct five different return series of stock index futures contracts. The results show that, regardless of the criterion applied, there are not significant differences between the resultant series. Therefore, the least complex method can be used in order to reach the same conclusions. © 2009 Wiley Periodicals, Inc. Jrl Fut Mark 28:684,694, 2009 [source] The World of Carbon Nanotubes: An Overview of CVD Growth MethodologiesCHEMICAL VAPOR DEPOSITION, Issue 6 2006L. Terranova Abstract Carbon nanotubes are a new form of completely artificial crystalline carbon, which have never been found as a natural form. These fascinating hollow cylinders can be considered as prototypes of one-dimensional quantum wires, exhibit peculiar chemical-physical properties very different from those of other C-based nanostructures, and are envisaged to have potential in a wide range of applications. This review examines some of the most interesting CVD methodologies employed for the synthesis of carbon nanotubes. The results obtained from different methodologies demonstrate that carbon nanotubes can be grown by CVD under a wide range of experimental conditions, permitting flexible, tunable synthesis. Overall, in the last few years, CVD approaches have emerged as the most promising among those proposed for synthesizing carbon nanotubes. [source] | |||||||||||||||||||||||||||||||