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Different Samples (different + sample)
Selected AbstractsMetabolomic fingerprinting of plant extracts,JOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 12 2006L. Mattoli Abstract The standardization and quality control of plant extracts is an important topic, in particular, when such extracts are used for medicinal purposes. Consequently, the development of fast and effective analytical methods for metabolomic fingerprinting of plant extracts is of high interest. In this investigation, electrospray mass spectrometry (ESI-MS) and 1H NMR techniques were employed with further statistical analyses of the acquired data. The results showed that negative ion mode ESI-MS is particularly effective for characterization of plant extracts. Different samples of the same species appear well-clustered and separated from the other species. To verify the effectiveness of the method, two other batches of extracts from a species, in which the principal components were already identified (Cynara scolymus), were analyzed, and the components that were verified by the principal component analysis (PCA) were found to be within the region identified as characteristic of Cynara Scolymus extracts. The data from extracts of the other species were well separated from those pertaining to the species previously characterized. Only the case of a species that was strictly correlated from a botanical point of view, with extracts that were previously analyzed, showed overlapping. Copyright © 2006 John Wiley & Sons, Ltd. [source] Methylation of Chitosan with Iodomethane: Effect of Reaction Conditions on Chemoselectivity and Degree of SubstitutionMACROMOLECULAR BIOSCIENCE, Issue 10 2003Elisabete Curti Abstract N,N,N -trimethylchitosan (TMC) was prepared by reacting purified chitosan with iodomethane, in the presence of sodium hydroxide, water and sodium iodide, at room temperature. The reaction medium was N -methyl-2-pyrrolidone. Different samples of TMC were obtained by adding to the reaction medium a fixed volume (5.5 mL) of aqueous NaOH solutions at different concentrations (15, 20, 30 and 40 wt.-%) and carrying out the reactions for 9 or 24 h. The features observed in the 1H and 13C NMR spectra of these chitosan derivatives, in respect of the chemical shift, number and relative intensity of the signals, depended strongly on the excess of NaOH and H3CI added to the reaction medium, but when the lowest excess was employed, the characteristics of the derivative were not affected by the reaction time to the same extent. The average degree of quaternization of these N -methylated derivatives of chitosan ranged from 10.5% to 44.8%, according to the reaction conditions. Increasing the excess of NaOH, in reactions carried out for 9 h, resulted in TMC samples with progressively higher content of trimethylated sites however, the reaction yields were correspondingly lower and O -alkylation was favored in these cases. 1H NMR spectrum of sample [AX]24h dissolved in D2O (Cp,=,10 g/L). [source] Trait-Specific Dependence in Romantic RelationshipsJOURNAL OF PERSONALITY, Issue 5 2002Bruce J. Ellis ABSTRACT Informed by three theoretical frameworks,trait psychology, evolutionary psychology, and interdependence theory,we report four investigations designed to develop and test the reliability and validity of a new construct and accompanying multiscale inventory, the Trait-Specific Dependence Inventory (TSDI). The TSDI assesses comparisons between present and alternative romantic partners on major dimensions of mate value. In Study 1, principal components analyses revealed that the provisional pool of theory-generated TSDI items were represented by six factors: Agreeable/Committed, Resource Accruing Potential, Physical Prowess, Emotional Stability, Surgency, and Physical Attractiveness. In Study 2, confirmatory factor analysis replicated these results on a different sample and tested how well different structural models fit the data. Study 3 provided evidence for the convergent and discriminant validity of the six TSDI scales by correlating each one with a matched personality trait scale that did not explicitly incorporate comparisons between partners. Study 4 provided further validation evidence, revealing that the six TSDI scales successfully predicted three relationship outcome measures,love, time investment, and anger/upset,above and beyond matched sets of traditional personality trait measures. These results suggest that the TSDI is a reliable, valid, and unique construct that represents a new trait-specific method of assessing dependence in romantic relationships. The construct of trait-specific dependence is introduced and linked with other theories of mate value. [source] Changes in the rRNA levels of specific microbial groups in activated sludge during sample handling and storageLETTERS IN APPLIED MICROBIOLOGY, Issue 2 2005J.E. Keith Abstract Aims:, To quantitatively analyse the changes in group-specific rRNA levels in activated sludge as a function of sample handling and storage procedure. Methods and Results:, Quantitative membrane hybridizations with 32P-labelled oligonucleotide probes were used to analyse the effects of different sample handling and storage conditions on the relative rRNA levels of the alpha, beta, and gamma-Proteobacteria, the Cytophaga-Flavobacteria group, and the mycolic acid-containing actinomycetes in activated sludge. Group-specific rRNA levels, expressed as percentages of total 16S rRNA detected with a universal probe, in samples maintained at room temperature significantly changed after 48 h. Group-specific rRNA levels in samples treated with chloramphenicol showed significant change after 72 h. Conclusions:, Sample storage at room temperature is a viable option if freezing or analysis can be performed within 24 h, while treatment with chlorampenicol can extend that time to at least 48 h. Significance and Impact of the Study:, Handling, shipping, and storage of environmental samples under several conditions may result in inaccurate determination of the microbial populations in microbial ecology studies. [source] Dietary Planning as a Mediator of the Intention,Behavior Relation: An Experimental-Causal-Chain DesignAPPLIED PSYCHOLOGY, Issue 2008Tabea Reuter Health behavior change is seen as a self-regulatory process that consists of a motivation phase of goal setting and a volition phase of goal pursuit. Previous studies suggest that the intention,behavior association is mediated by planning. However, evidence is based on observational studies rather than on experimental designs. To validate the causal assumptions, an experimental-causal-chain design was employed. Study 1 (n= 145) examined whether changing dietary intentions by a motivational intervention engenders changes in planning activities 1 month later. Study 2 (n= 115) examined, in a different sample, whether a volitional planning intervention engenders changes in dietary behavior 1 month later. In both studies, repeated measures ANOVAs revealed a significant Time × Condition interaction. Changes in intention mediated the effects of the motivational intervention on planning activities (Study 1). Changes in planning mediated the effect of a planning intervention on dietary behavior (Study 2). Previous observational findings on planning as a mediator in the intention,behavior association were supported by the two experiments. The findings might help to identify points of intervention in the process underlying health behavior change. Le changement de comportement au plan de la santé est considéré comme un processus d'auto-régulation qui se compose d'une phase de motivation (fixation des buts) et d'une phase de volition (poursuite des buts). Des études précédentes suggèrent que le passage de l'intention au comportement est médiatisé par la planification. Ces résultats sont obtenus par voie d'observations plutôt que par expérimentations. Pour valider les hypothèses de causalité, un modèle de chaîne-causale-expérimentale a été employé. L'étude 1 examine si, en changeant les intentions alimentaires par une intervention motivationnelle, on obtient des changements dans la planification des activités un mois après (n= 145). L'étude 2 examine, sur un échantillon différent, si la planification d'une intervention engendre des changements du comportement alimentaire un mois plus tard (n= 115). Pour ces deux études, des ANOVA à mesures répétées révèlent une interaction significative entre le temps et la condition étudiée. Les changements de l'intention influencent les effets de l'intervention motivationnelle sur la planification des activités (étude 1). Les changements de la planification influencent les effets de l'intervention de la volition sur le comportement alimentaire (Etude 2). Les résultats obtenus par observation sur la planification comme lien entre l'intention et le comportement sont confirmés par les expérimentations. Les résultats peuvent permettre d'identifier les modalités d'interventions relatives au processus sous-tendant le changement du comportement de santé. [source] Determination of xanthohumol in hops (Humulus lupulus L.) by nonaqueous CEELECTROPHORESIS, Issue 6 2007Javor Kac Dr. Abstract Xanthohumol (XN) is a prenylated chalcone with antimutagenic and anticancer activity from hops. A nonaqueous reverse polarity capillary electrophoretic method for the determination of XN in hop extract was developed and validated. The optimal parameters were a 64.5,cm long fused-silica capillary with 50,,m id at 25°C; 30,kV negative voltage (anode at detector side of the capillary); nonaqueous buffer with 75,mM NaOH and 50,mM boric acid in methanol; hydrodynamical injection with 10,mbar for 40,s; and detection at 440,nm. XN, isoxanthohumol (IX), colupulone, adlupulone, and n -lupulone were well resolved on the electropherogram. The LOD for XN was 0.05,mg/L and RSD for peak area was below 3%. The amount of XN in different samples of hop pellets varied from 0.14 to 0.42%. [source] Pilot study of capillary electrophoresis coupled to mass spectrometry as a tool to define potential prostate cancer biomarkers in urineELECTROPHORESIS, Issue 14 2005Dan Theodorescu Dr. Abstract We describe the use of capillary eletrophoresis (CE) coupled with mass spectrometry (MS) to identify single polypeptides and patterns of polypeptides specific for prostate cancer (CaP) in human urine. Using improved sample preparation methods that enable enhanced comparability between different samples, we examined samples from 47,patients who underwent prostate biopsy. Of this group, 21,patients had benign pathology and 26 with,CaP, and these were used to define potential biomarkers, which allow discrimination between these two states. In addition, CE-MS data from these 47,urine samples were compared to that of 41,young men (control) without known or suspected clinical CaP to further confirm the polypeptides indicative for CaP. Upon crossvalidation of the same samples, several polypeptides were selected that enabled correct classification of the CaP patients with 92% sensitivity and 96% specificity. We then examined an additional 474,samples from patients with renal disease enrolled in other studies and found that 14 (3%) had polypeptides suggestive of CaP possibly indicating that they harbor clinical CaP. In conclusion, this early pilot study suggests that CE-MS of urine warrants further investigation as a tool that can identify putative biomarkers for CaP. [source] Microautosamplers for discrete sample injection and dispensationELECTROPHORESIS, Issue 9 2005Chun-Wei Huang Abstract Microfluidic systems show considerable potential for use in the continuous reaction and analysis of biosamples for various applications, such as drug screening and chemical synthesis. Typically, microfluidic chips are externally connected with large-scale autosamplers to inject specific volumes of discrete samples in the continuous monitoring and analysis of multiple samples. This paper presents a novel microelectromechanical system (MEMS)-based autosampler capable of performing the discrete injection and dispensation of variable-volume samples. This microdevice can be integrated with other microfluidic devices to facilitate the continuous monitoring and analysis of multiple biosamples. By means of electroosmotic focusing and switching controlled by the direct application of electric sources on specific fluid reservoirs, a precise sample volume can be injected into the specified outlet port. Fluorescence dye images verify the performance of the developed device. An injection-and-washing scheme is developed to prevent cross-contamination during the continuous injection of different samples. This approach renders feasible the injection of several discrete samples using a single microchip. Compared to its large-scale counterparts, the developed microautosampler is compact in size, has low fabrication costs, is straightforward to control, and most importantly, is readily integrated with other microfluidic devices (e.g., microcapillary electrophoresis chips) to form a microfluidic system capable of the continuous monitoring and analysis of bioreactions. The proposed microautosampler could be promising towards realizing the micrototal analysis system (,-TAS) concept. [source] Chemical evaluation of some paprika (Capsicum annuum L.) seed oilsEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 12 2009Bertrand Matthäus Dr. Abstract The oil contents of seeds from paprika (Capsicum annuum L.) collected from different locations in Turkey and Italy varied in a relatively wide range from 8.5,g/100,g to 32.6,g/100,g. The fatty acid, tocopherol and sterol contents of the oils from different paprika seeds were investigated. The main fatty acids in paprika seed oils were linoleic acid (69.5,74.7,g/100,g), oleic acid (8.9,12.5,g/100,g) and palmitic acid (10.7,14.2,g/100,g). The oils contained an appreciable amount of ,-tocopherol (306.6,602.6,mg/kg), followed by ,-tocopherol (7.3,148.7,mg/kg). The major sterols were ,-sitosterol (1571.4,4061.7,mg/kg), campesterol (490.8,1182.7,mg/kg), and ,5 -avenasterol (374.5,899.6,mg/kg). The total concentration of sterols ranged from 3134.0,mg/kg to 7233.7,mg/kg. Remarkable amounts of cholesterol were found in the different samples (164.6,491.0,mg/kg). The present study showed that paprika seeds are a potential source of valuable oil that could be used for edible and industrial applications. [source] Comprehensive linkage and linkage heterogeneity analysis of 4344 sibling pairs affected with hypertension from the Family Blood Pressure ProgramGENETIC EPIDEMIOLOGY, Issue 3 2007Tiffany A. Greenwood Abstract Linkage analyses of complex, multifactorial traits and diseases, such as essential hypertension, have been difficult to interpret and reconcile. Many published studies provide evidence suggesting that different genes and genomic regions influence hypertension, but knowing which of these studies reflect true positive results is challenging. The reasons for this include the diversity of analytical methods used across these studies, the different samples and sample sizes in each study, and the complicated biological underpinnings of hypertension. We have undertaken a comprehensive linkage analysis of 371 autosomal microsatellite markers genotyped on 4,334 sibling pairs affected with hypertension from five ethnic groups sampled from 13 different field centers associated with the Family Blood Pressure Program (FBPP). We used a single analytical technique known to be robust to interpretive problems associated with a lack of completely informative markers to assess evidence for linkage to hypertension both within and across the ethnic groups and field centers. We find evidence for linkage to a number of genomic regions, with the most compelling evidence from analyses that combine data across field center and ethnic groups (e.g., chromosomes 2 and 9). We also pursued linkage analyses that accommodate locus heterogeneity, which is known to plague the identification of disease susceptibility loci in linkage studies of complex diseases. We find evidence for linkage heterogeneity on chromosomes 2 and 17. Ultimately our results suggest that evidence for linkage heterogeneity can only be detected with large sample sizes, such as the FBPP, which is consistent with theoretical sample size calculations. Genet. Epidemiol. 2007. © 2007 Wiley-Liss, Inc. [source] Contiguous multi-proxy analyses (X-radiography, diatom, pollen, and microcharcoal) of Holocene archaeological features at Kuk Swamp, Upper Wahgi Valley, Papua New GuineaGEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 6 2009Tim Denham Contiguous multi-proxy analyses (X-radiography, diatom, pollen, and microcharcoal) have been conducted on the fills of early, mid-, and mid-late Holocene features at Kuk Swamp, Upper Wahgi Valley, Papua New Guinea. The features are associated with key periods of archaeological interest: plant exploitation (ca. 10,000 cal yr B.P.), earliest cultivation (6950,6440 cal yr B.P.), and earliest ditches (ca. 4000 cal yr B.P.). The analyses are designed to clarify uncertainties regarding the reliability and association of different samples within feature fills for the interpretation of human activities on the wetland in the past. Methodologically, these investigations have clarified site formation processes, including pedogenesis within feature fills, which enable a better determination of archaeological associations for different samples within those fills. Substantively, the results provide higher resolution interpretations of paleoenvironments and past human activities on the wetland margin. © 2009 Wiley Periodicals, Inc. [source] The Impact of Trade Liberalization on Regional Disparities in MexicoGROWTH AND CHANGE, Issue 1 2002Javier Sánchez-Reaza After a long period of industrialization based on import substitution (ISI), Mexico started to open up its economy by accessing the General Agreement on Tariffs and Trade (GATT) in 1986. The export-promotion strategy was transformed into one of regional integration with the signing of the North American Free Trade Agreement (NAFTA) in 1994. The paper explores the impact of the opening of the economy on regional disparities in Mexico using , and ,-convergence analyses. Four different samples have been employed to control for possible data bias linked to the inclusion of oil-producing and maquiladora-based states. The results show that whereas the final stages of the ISI period were dominated by convergence trends, trade liberalization (GATT) and economic integration (NAFTA) have led to divergence. In particular, the NAFTA period is related to divergence regardless of the type of analysis chosen and the sample used. [source] Development and initial validation of an instrument measuring managerial coaching skillHUMAN RESOURCE DEVELOPMENT QUARTERLY, Issue 2 2005Gary N. McLean This article reports on two studies that used three different samples (N = 644) to construct and validate a multidimensional measure of managerial coaching skill. The four dimensions of coaching skill measured were Open Communication, Team Approach, Value People, and Accept Ambiguity. The two studies assessed the context adequacy, dimensionality, reliability, factor structure, and construct validity of the scale. Preliminary reliability and validity evidence of the scale was determined. Consequently, the coaching scale provides future researchers with a valuable tool to measure coaching skill in organizational studies, and it offers human resource development professionals a valid instrument to develop effective managers. [source] What do People Want from their Jobs?INTERNATIONAL JOURNAL OF SELECTION AND ASSESSMENT, Issue 1 2010The Big Five, core self-evaluations, work motivation If people are differentially motivated on the basis of individual differences, this implies important practical consequences with respect to staffing decisions and the selection of the right motivational techniques for managers. In two different samples (students facing graduation vs full-time employees), the relationships between personality traits and the preference for job characteristics concerning either extrinsic (job environment) or intrinsic job features (work itself) were investigated. Two personality traits [openness to experience and core self-evaluations (CSE)] were consistently found to be positively related to the preference concerning work characteristics, and CSE showed incremental validity with regard to intrinsic work motivation factors (e.g., experienced meaningfulness, autonomy). Furthermore, age was differentially linked to those job characteristics. The results are discussed with regards to the optimal Person,Job Fit and the practical utility of the personality constructs. [source] Approaches to learning at work and workplace climateINTERNATIONAL JOURNAL OF TRAINING AND DEVELOPMENT, Issue 1 2003John R. Kirby Three studies are reported concerning employees' approaches to learning at work and their perceptions of the workplace environment. Based on prior research with university students, two questionnaires were devised, the Approaches to Work Questionnaire (AWQ) and the Workplace Climate Questionnaire (WCQ). In Studies 1 and 2, these questionnaires were administered to two different samples of employees, and the factor structure of the questionnaires was explored. In Study 3, the two data sets were combined, and a random half of it was used to develop reduced sets of items that addressed selected factors for each of the questionnaires. The other half of the data was used to test the scales developed. For the AWQ, three factors are proposed: deep, surface-rational, and surface-disorganised. The first of these is consistent with the student learning literature, but the other two represent a division of a unitary surface factor. The three components of the WCQ are good supervision, choice-independence, and workload. Correlations between scales indicated that the deep approach is positively associated with good supervision and choice-independence, whereas the surface-disorganised approach is negatively associated with these two constructs and positively associated with workload. Surface-rational is negatively, though less strongly associated with choice-independence. Suggestions are presented for use of these instruments in future research and practice. [source] Menstrual Attitude Questionnaire: confirmatory and exploratory factor analysis with Turkish samplesJOURNAL OF ADVANCED NURSING, Issue 3 2009Mehmet Z. Firat Abstract Title.,Menstrual Attitude Questionnaire: confirmatory and exploratory factor analysis with Turkish samples. Aim., This study is a report of an investigation of the psychometric properties of the Turkish version of the Menstrual Attitude Questionnaire. Background., Cultural, social and family environments influence women's beliefs about and attitudes towards menstruation. Awareness of these beliefs and/or attitudes and their cultural origins is necessary to understand women and their reactions to menstruation when offering health care. Although the Menstrual Attitude Questionnaire has been used in several studies, the psychometric properties of the Turkish version have not been investigated. Methods., Confirmatory factor analyses were carried out with two different samples , high school (n = 650) and undergraduate university students (n = 569) , in Turkey in the spring semester of 2006. Exploratory factor analyses were then used to modify the factor structure. Results., Confirmatory factor analysis did not confirm the factor model reported in the United States of America. However, compared with British and Indian samples, Turkish attitudes showed better fit than both British and Indian samples with comparative fit index values of 0·776 and 0·797 for the high school and university samples respectively. Finally, exploratory factor analysis yielded a 28-item measure for the high school sample and 31-item measure for the university sample, with a 5-factor solution. Reliability estimates of both scales were satisfactory, being 0·73 for the high school and 0·79 for the university sample. Conclusion., The modified 5-factor Menstrual Attitude Questionnaire could be a useful tool for assessing menstrual attitudes among Turkish high school and university students. The overall score permits comparison with results from earlier studies using the original instrument. [source] Influence of resin viscosity and vacuum level on mechanical performance of sandwich structures manufactured by vacuum baggingADVANCES IN POLYMER TECHNOLOGY, Issue 1 2010A. Valenza Abstract The choice of process parameters is critical in optimizing the mechanical properties of sandwich structures produced using the vacuum bagging technique. The aim of this paper is to analyze how the viscosity of the resin/curing agent system and the vacuum level influence the morphology and the mechanical behavior of sandwich beams with composite faces (epoxy resin and glass fiber fabric named COMBI 900) and a PVC foam core. Four different sandwich structures were produced by varying the viscosity of the epoxy resin/curing agent at constant maximum vacuum pressure. Three further structures were manufactured by varying the strength of the vacuum with the resin viscosity maintained constant at the minimum level. Three point bending tests were carried out on all seven sandwiches. The analysis shows that although both parameters affect the mechanical characteristics of the structure, the viscosity of the resin system is clearly the more influential of the two. The morphological structure of the sandwiches was analyzed both by scanning electron microscope (SEM) and by muffle furnace ignition to calculate the percentage of fibers, matrices, and voids present in the different samples © 2010 Wiley Periodicals, Inc. Adv Polym Techn 29:20,30, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20172 [source] Evaluating the inter-respondent (consumer vs. staff) reliability and construct validity (SIS vs.JOURNAL OF INTELLECTUAL DISABILITY RESEARCH, Issue 4 2009Vineland) of the Supports Intensity Scale on a Dutch sample Abstract Background Despite various reliability studies on the Supports Intensity Scale (SIS), to date there has not been an evaluation of the reliability of client vs. staff judgments. Such determination is important, given the increasing consumer-driven approach to services. Additionally, there has not been an evaluation of the instrument's construct validity on a non-English speaking sample. This is important as the SIS is currently translated into 13 languages. Method Data were collected in two different samples, using the Dutch translation of the SIS and the Vineland-Z. Results There was a significant correlation between ratings of staff and consumers on the SIS; however, the relationship between the mean scores of consumer and staff responses indicated significant differences in staff and consumer scores. All correlations between the Vineland-Z domains and the SIS subscales were significant and negative, ranging from ,0.37 to ,0.89. Conclusions Analyses of the inter-respondent reliability suggest that one needs to consider the source of information regarding needed supports carefully. The significant negative correlations between SIS and Vineland-Z reflect that the SIS is measuring a different construct (needed support) than the Vineland-Z (adaptive behaviour). The results of the two studies provide additional support for the etic (universal) properties of the SIS, as both hypotheses were confirmed. In conclusion, SIS users are provided with a wealth of information that can be used for multiple purposes. [source] New approach for rapid detection of known hemoglobin variants using LC-MS/MS combined with a peptide database,JOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 3 2007F. Basilico Abstract The identification of hemoglobin (Hb) variants is usually performed by means of different analytical steps and methodologies. Phenotypic methods, such as gel electrophoresis and high performance liquid chromatography, are used to detect the different electrophoretic or chromatographic behaviors of hemoglobin variants in comparison to HbA0 used as a control. These data often need to be combined with mass spectrometry analyses of intact globins and their tryptic peptide mixtures. As an alternative to a ,step-by-step' procedure, we have developed a ,single step' approach for the identification of Hb variants present in biological samples. This is based on the µHPLC-ESI-MS/MS analysis of the peptide mixture generated by a tryptic digestion of diluted Hb samples and an in-house new database containing solely the variant tryptic peptide of known human Hb variants. The experimental results (full MS and MS/MS spectra) are correlated with theoretical mass spectra generated from our in-house-built variant peptide database (Hbp) using the SEQUEST algorithm. Simple preparation of samples and an automated identification of the variant peptide are the main characteristics of this approach, making it an attractive method for the detection of Hb variants at the routine clinical level. We have analyzed 16 different samples, each containing a different known variant of hemoglobin. Copyright © 2006 John Wiley & Sons, Ltd. [source] Oligosaccharide sequences in Quillaja saponins by electrospray ionization ion trap multiple-stage mass spectrometryJOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 6 2004Susanna Broberg Abstract Ten different samples with 13 previously identified saponin structures from Quillaja saponaria Molina were investigated by electrospray ionization ion trap multiple-stage mass spectrometry (ESI-ITMSn) in positive and negative ion modes. Both positive and negative ion mode MS1,MS4 spectra were analyzed, showing that structural information on the two oligosaccharide parts in the saponin can be obtained from positive ion mode spectra whereas negative ion mode spectra mainly gave information on one of the oligosaccharide parts. Analysis of MS1,MS4 spectra identified useful key fragment ions important for the structural elucidation of Quillaja saponins. A flowchart involving a stepwise procedure based on key fragments from MS1,MS3 spectra was constructed for the identification of structural elements in the saponin. Peak intensity ratios in MS3 spectra were found to be correlated with structural features of the investigated saponins and are therefore of value for the identification of terminal monosaccharide residues. Copyright © 2004 John Wiley & Sons, Ltd. [source] Potential of ,flat' fibre evanescent wave spectroscopy to discriminate between normal and malignant cells in vitroJOURNAL OF MICROSCOPY, Issue 2 2007Z. HAMMODY Summary The present study focuses on evaluating the potential of flattened AgClBr fibre-optic evanescent wave spectroscopy (FTIR-FEWS) technique for detection and identification of cancer cells in vitro using cell culture as a model system. The FTIR-FEWS results are compared to those from FTIR-microspectroscopy (FTIR-MSP) method extensively used to identify spectral properties of intact cells. Ten different samples of control and malignant cells were measured in parallel by the above two methods. Our results show a significant similarity between the results obtained by the two methodologies. The absorbance level of Amide I/Amide II, phosphates and carbohydrates were significantly altered in malignant compared to the normal cells using both systems. Thus, common biomarkers such as Amide I/Amide II, phosphate and carbohydrate levels can be derived to discern between normal and cancer cells. However, marked differences are also noted between the two methodologies in the protein bands due to CH3 bending vibration (1480,1350 cm,1). The spectral differences may be attributed to the variation in the penetration depth of the two methodologies. The use of flattened fibre rather than the standard cylindrical fibre has several practical advantages and is considered as an important step towards in vivo measurements in real time, such as that of skin nevi and melanoma using special designs of fibre-optic,based sensors. [source] Rate constants of mass transfer kinetics in reversed phase liquid chromatographyAICHE JOURNAL, Issue 12 2005Lan Hong Abstract The parameters of the kinetics of mass transfer of several n -alkylbenzenes were measured by the method of moments on a series of columns prepared with different samples of the same RPLC packing material having widely different average particle diameters, from 3 to 50 ,m. These data were analyzed using the available models, and correlations. The best agreement between experimental and theoretical data was obtained under the assumption that the rate constant for the external mass transfer increases with increasing average particle size, an unexpected conclusion. It was also shown that the interpretation of the relative importance of the roles of pore diffusivity and surface diffusivity in the internal mass transfer kinetics is somewhat ambiguous and that the conclusion to be drawn from experimental results depends on the assumptions made regarding the tortuosity model and the relationship between kext and the average particle size. © 2005 American Institute of Chemical Engineers AIChE J, 2005 [source] The Sleep and Settle Questionnaire for parents of infants: Psychometric propertiesJOURNAL OF PAEDIATRICS AND CHILD HEALTH, Issue 5 2001S Matthey Objective: To determine the psychometric properties of a parent-report questionnaire (Sleep and Settle Questionnaire (SSQ)) assessing: (i) the infant's sleep and settling behaviour, and (ii) the parent's level of concern with such behaviours. Methodology: Test-retest reliability was determined by administering the SSQ to 20 mothers on two occasions, 7,14 days apart. Validity was determined by comparing SSQ responses between mothers with 6-week-old infants who, on a semistructured questionnaire, reported no sleep or settling difficulties (n = 56,60) with those who reported they were experiencing difficulties (n = 133). Further comparison was made with a sample of mothers (n = 34,36) attending a community class on sleep and settling difficulties with infants. Sensitivity to change was determined by comparing mothers' SSQ responses at 6-weeks and 6-months postpartum. Results: The SSQ was found to have low test,retest reliability on items referring to the infants' sleep and settling behaviour, but moderate reliability for the extent that such behaviour bothered the parent. Comparison across the different samples showed good discriminant and concurrent validity. Conclusions: Parental reports on the SSQ indicates that over a short period (1,2 weeks) the infants' sleep and settling behaviour can change considerably, but that the extent to which such behaviour bothers the parent is more stable. Good validity demonstrates the SSQ is sensitive to differing infant behaviour. It is recommended as both a clinical and research instrument, and could be used to complement assessments focusing on the parent's psychosocial adjustment in the early postpartum period. [source] Learning To Be Saints or Sinners: The Indirect Pathway From Sensation Seeking to Behavior Through Mastery OrientationJOURNAL OF PERSONALITY, Issue 4 2008Peter J. O'Connor ABSTRACT Recently, a model of learning has been proposed that argues that Sensation Seeking indirectly predicts functional and dysfunctional behaviors through Mastery Orientation. Central components of the model were tested across two studies. Study 1 tested the proposed indirect effect in the prediction of functional behavior using an objective learning task. Study 2 tested the proposed indirect effects in the prediction of functional and dysfunctional self-report behavior across two very different samples. Regression analyses in both studies generally supported the proposed model. [source] The Language of Intoxication: Preliminary InvestigationsALCOHOLISM, Issue 3 2009Ash Levitt Background:, The extensive vocabulary individuals use to describe alcohol's subjective effects has largely gone unexamined in contemporary alcohol research. The present study examined the language drinkers use to describe their own intoxication. It is argued that this language can provide a more complete characterization of alcohol's subjective effects than is available from existing objective and subjective measures of alcohol use and can inform future self-report research. Method:, Toward this goal, a preliminary, cross-sectional, web-based study of the familiarity and usage of current intoxication-related words was conducted in 2 different samples (n = 290 and 146, respectively) of university undergraduates. Results:, Exploratory factor analyses using data from the first sample and confirmatory factor analyses using data from the second sample similarly showed that commonly used terms loaded onto 2 factors, which directly reflected the number of drinks required to be considered moderately or heavily intoxicated, respectively. Gender differences were also found in the familiarity and self-use of some terms across both samples. Conclusions:, The findings suggest that alcohol researchers include multiple intoxication-related terms in future self-report research, and to periodically assess current intoxication-related vocabulary considering demographic, generational, and socio-cultural differences. [source] PREFERENCE FOR ONE OF TWO IDENTICAL STIMULI: EXPECTATIONS, EXPLICIT INSTRUCTIONS AND PERSONAL TRAITSJOURNAL OF SENSORY STUDIES, Issue 2010KATHRYN W. CHAPMAN ABSTRACT Most consumers, given two identical food samples, express a preference for one, rather than choosing a no-preference option. The stability and potential causes of this seemingly irrational preference were examined across three trials under different conditions, specifically, when the first test pair was identical or different, and when participants were explicitly told that the pairs would often be identical. Choice of no preference typically increased from the first to second trial, especially for groups who saw a pair of different samples on the first trial. The explicit instruction that samples might be the same failed to reduce expressing a preference on the initial trial although it had some effect on later trials. Analysis, by individuals, of sequences of preference or no-preference responses across trials support independence of sequential responses and argue against stable personal traits as a predictor of preference choice. PRACTICAL APPLICATIONS More research needs to be done to understand the origins and operation of biases in preference tests. When tested under conditions in which the samples differ only slightly, participants tend to avoid the no-preference option. This is potentially important when interpreting the results of preference tests and assigning practical significance to their outcomes. Also, single trial testing may produce somewhat different results from multi-trial testing, the latter allowing for examination of effects of variation in recent experience. [source] THE CONSUMER SENSORY PERCEPTION OF PASSION-FRUIT JUICE USING FREE-CHOICE PROFILINGJOURNAL OF SENSORY STUDIES, Issue 1 2005ROSIRES DELIZA ABSTRACT Free-choice profiling (FCP) was carried out in order to investigate how naive consumers (who had never tried the product before) described and perceived passion-fruit juice. This method allows participants to use their own attributes to describe and quantify food products and beverages. The study used four different samples of passion-fruit juice, analyzed by 10 consumers in three replicates. The data were analyzed by using generalized Procrustes analysis. The first and second dimension accounted for 78.7% of the variance. The product consensus configuration revealed that assessors were able to reproduce samples' description, and also to differentiate samples. Free-choice profiling is a useful method for describing consumer perception of passion-fruit juice. [source] Headspace single-drop microextraction of herbal essential oilsJOURNAL OF SEPARATION SCIENCE, JSS, Issue 2 2008Martin Adam Abstract A method employing the headspace single-drop microextraction (HS-SDME) is presented for the determination of essential oils in dried herbal leaves. By optimising the key experimental parameters, a linear response for the individual target compounds was obtained in the concentration range from LOQ to 4 mg/mL (r2 = 0.9912,0.9998), with LODs from 3.3 up to 20.5 ,g per 100 g of dried leaves, and the repeatability within the RSD of 2.1,8.9%. The HS-SDME-based procedure, enabling a rapid and simple analysis of essential oils in herbs, was applied to selected real samples (nine essential oils in four different samples) in combination with GC-FID identification and quantification of the target volatiles. [source] Simultaneous determination of iridoids, phenolic acids, flavonoids, and saponins in Flos Lonicerae and Flos Lonicerae Japonicae by HPLC-DAD-ELSD coupled with principal component analysisJOURNAL OF SEPARATION SCIENCE, JSS, Issue 18 2007Chun-Yun Chen Abstract A method, HPLC coupled with diode-array and evaporative light scattering detectors (HPLC-DAD-ELSD), was newly developed to evaluate the quality of Flos Lonicerae (FL) and Flos Lonicerae Japonicae (FLJ), through a simultaneous determination of multiple types of bioactive components. By employing DAD, the detection wavelengths were set at 240 nm for the determination of iridoids, 330 nm for phenolic acids, and 360 nm for flavonoids, respectively. While ELSD, connected in series after DAD, was applied to the determination of saponins. This assay was fully validated with respect to precision, repeatability, and accuracy. Moreover, principal component analysis (PCA) was used for the similarity evaluation of different samples, and it was proven straightforward and reliable to differentiate FL and FLJ samples from different origins. For PCA, two principal components have been extracted. Principal component 1 (PC1) influences the separation between different sample sets, capturing 54.598% variance, while principal component 2 (PC2) affects differentiation within sample sets, capturing 12.579% variance. In conclusion, simultaneous quantification of bioactive components by HPLC-DAD-ELSD coupled with PCA would be a well-acceptable strategy to differentiate the sources and to comprehensively control the quality of the medicinal plants FL and FLJ. [source] Capillary electrophoresis with capacitively coupled contactless conductivity detection for low molecular weight organic acids in different samplesJOURNAL OF SEPARATION SCIENCE, JSS, Issue 18 2007Wai Siang Law Abstract CE with capacitively coupled contactless conductivity detection (CE-C4D) was explored and validated for the identification and quantification of organic acids in various types of samples. The analyses were performed under optimized conditions, using a buffer system composed of 20 mM MES-histidine (His), pH 6.0, 0.1 mM CTAB, 0.025% HP-,-CD, and 10% methanol. The investigation included a study of the effects of buffer pH, concentration of CTAB, type and concentration of organic additives, on the migration behavior, resolution and selectivity of the organic acids. The intra- and interday RSDs (n = 6) obtained for migration time and peak area were typically in the range of 0.12,2% and 0.5,4%, respectively. Linearity, detection limits, and repeatability were evaluated. In order to evaluate the application potential of the developed method, real samples from different sources were analyzed. The results demonstrate that CE-C4D is a versatile tool for analyzing organic acids in beverages, Chinese herbal medicines (CHM) and plants as it allows for their detection, identification, and quantification. [source] | ||||||||||||||||||||||||||||||||||||||||||||||||||||