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Single Method (single + method)
Selected AbstractsA comparative study of awareness methods for peer-to-peer distributed virtual environmentsCOMPUTER ANIMATION AND VIRTUAL WORLDS (PREV: JNL OF VISUALISATION & COMPUTER ANIMATION), Issue 5 2008S. Rueda Abstract The increasing popularity of multi-player online games is leading to the widespread use of large-scale Distributed Virtual Environments (DVEs) nowadays. In these systems, peer-to-peer (P2P) architectures have been proposed as an efficient and scalable solution for supporting massively multi-player applications. However, the main challenge for P2P architectures consists of providing each avatar with updated information about which other avatars are its neighbors. This problem is known as the awareness problem. In this paper, we propose a comparative study of the performance provided by those awareness methods that are supposed to fully solve the awareness problem. This study is performed using well-known performance metrics in distributed systems. Moreover, while the evaluations shown in the literature are performed by executing P2P simulations on a single (sequential) computer, this paper evaluates the performance of the considered methods on actually distributed systems. The evaluation results show that only a single method actually provides full awareness to avatars. This method also provides the best performance results. Copyright © 2008 John Wiley & Sons, Ltd. [source] Measures of adherence to epilepsy treatment: Review of present practices and recommendations for future directionsEPILEPSIA, Issue 7 2008Angelia M. Paschal Summary Epilepsy is one of the most common neurological disorders worldwide, and the majority of people with epilepsy who live in developed countries manage their condition with antiseizure medication. Surprisingly, therefore, the literature on epilepsy does not document a comprehensive investigation of patient adherence to medication treatment. This paper reviews existing literature on direct and indirect measures of adherence. Based on this review, areas in need for further research have been identified, including improvement of self-report instruments, consideration of cultural factors, attention to patient literacy or numeracy levels, and inclusion of patient-guided measures. While no single method of determining adherence has proved effective, combining direct and indirect measures in a patient-guided, culturally competent atmosphere may increase adherence to treatment, improving health outcomes for this population. [source] Measuring the Dose of Nursing InterventionINTERNATIONAL JOURNAL OF NURSING TERMINOLOGIES AND CLASSIFICATION, Issue 4 2007David Reed PhD PURPOSE.,To increase awareness of the many issues involved in measuring the dose of nursing intervention in nursing interventions effectiveness research. METHODS.,Identify critical issues in measurement of the dose of nursing intervention and discuss decisions regarding dosage measurement made in a study of the effectiveness of nursing interventions. FINDINGS.,A single method can be applied to resolve two critical issues in intervention dosage measurement. CONCLUSIONS.,Those conducting nursing interventions effectiveness research must think explicitly about how intervention dosage will be measured and reported so that dosage can be replicated in research and practice. PRACTICE IMPLICATIONS.,,Measuring and reporting the dose of nursing intervention in research is essential to the development of an evidence base adequate to support practice. [source] A new methodology for the determination of the co-ordination area around stations of the fixed service (FS) with respect to mobile Earth stations on board vessels (ESVs)INTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS AND NETWORKING, Issue 6 2005Maria Koletta Abstract The extensive use of Earth stations located on board sea going vessels (ESVs) has created the necessity for the development of a new type of co-ordination area around the fixed service receivers (FSRs) operating in frequency bands C and Ku. To date there is not a single method concerning the calculation of the co-ordination area around the FSRs, which takes into account the mobility of the interfering stations. This paper addresses an in-depth analysis of the interference produced to the FSRs by the ESVs and proposes a new method for the development of the co-ordination area around the FSRs, taking into account parameters such as the velocity of the ESVs and their frequencies of passage from specific locations. Simulations performed for three different operational scenarios prove the validity of the new methodology. Copyright © 2005 John Wiley & Sons, Ltd. [source] Estimating deer abundance from line transect surveys of dung: sika deer in southern ScotlandJOURNAL OF APPLIED ECOLOGY, Issue 2 2001Fernanda F.C. Marques Summary 1Accurate and precise estimates of abundance are required for the development of management regimes for deer populations. In woodland areas, indirect dung count methods, such as the clearance plot and standing crop methods, are currently the preferred procedures to estimate deer abundance. The use of line transect methodology is likely to provide a cost-effective alternative to these methods. 2We outline a methodology based on line transect surveys of deer dung that can be used to obtain deer abundance estimates by geographical block and habitat type. Variance estimation procedures are also described. 3As an example, we applied the method to estimate sika deer Cervus nippon abundance in south Scotland. Estimates of deer defecation and length of time to dung decay were used to convert pellet group density to deer density by geographical block and habitat type. The results obtained agreed with knowledge from cull and sightings data, and the precision of the estimates was generally high. 4Relatively high sika deer densities observed in moorland areas up to 300 m from the forest edge indicated the need to encompass those areas in future surveys to avoid an underestimate of deer abundance in the region of interest. 5It is unlikely that a single method for estimating deer abundance will prove to be better under all circumstances. Direct comparisons between methods are required to evaluate thoroughly the relative merits of each of them. 6Line transect surveys of dung are becoming a widely used tool to aid management and conservation of a wide range of species. The survey methodology we outline is readily adaptable to other vertebrates that are amenable to dung survey methodology. [source] Identification of Acipenseriformes species in tradeJOURNAL OF APPLIED ICHTHYOLOGY, Issue 2008A. Ludwig Summary Sturgeons and paddlefishes (Acipenseridae) are highly endangered freshwater fishes. Their eggs (sold as caviar) are one of the most valuable wildlife products in international trade. Concerns of overharvesting and the conservation status of many of the 27 extant species of Acipenseriformes led to all species being included on the CITES Appendices in 1998. Since then international trade in all products and parts from sturgeon and paddlefish has been regulated. However, despite the controls on trade, unsustainable harvesting continues to threaten many populations. Illegal fishing and trade continues to be a threat to the management of these fish. To enforce the regulation of legal trade and prevention of illegal trade, the development of a uniform identification system for parts and derivates of Acipenseriformes has been identified as an urgent requirement. Ideally this system should be suitable for (i) identification at the species-level of caviar and other products from Acipenseriformes; (ii) population identification; (iii) source identification (wild vs aquaculture); and (iv) determining the age of caviar because strict timeframes govern its international trade. This paper reviews the techniques currently available and their potential to be used in an identification system for Acipenseriformes species and their products in trade. A review of all available identification techniques has shown that there is not a single method that can meet all requirements (see i,iv), and it does not appear to be feasible to develop such a method in the near future therefore the most appropriate methods need to be developed for each. Considering the advantages and disadvantages of all techniques reviewed in this document, the following conclusions can be drawn: (i) for the identification of species, approaches are recommended that target mitochondrial cytochrome b sequences (RFLP, nested PCR or direct sequencing). However, they show limitations for the detection of hybrids (although natural hybrids are rare, the number of artificially produced hybrids in aquaculture is increasing) and for the differentiation of the following closely related species complexes: Acipenser gueldenstaedti,Acipenser baerii,Acipenser persicus,Acipenser naccarii; Acipenser medirostris,Acipenser mikadoi; and Scaphirhynchus albus,Scaphirhynchus plathorhynchus,Scaphirhynchus suttkusi; (ii) the identification of different populations of the same species is currently not feasible because genetic data are incomplete for most populations, and stocking and release programmes, which have become more and more common, often result in a mixture of phenotypes and genotypes, thereby impeding the creation and application of such a population identification system; (iii) source identification based on genetic approaches can be excluded at present because there are no genetic differences between wild and hatchery-raised fish. This is the result of the continuing restocking of natural populations with captive fish and vice versa. However, because rearing (i.e. environmental) conditions are different, methods focusing on differences in water quality or food seem to be more appropriate (for example differences in fatty acid composition). So far, very few studies have been conducted and therefore, source identification methods merit further exploration; and (iv) the age of a product in trade cannot be detected by DNA-based methods and protein profiling is undoubtedly impractical due to hard-to-perform, labour-and cost-intensive methods, which are highly susceptible to protein degradation. Arising from the limits discussed above, the next steps in the development of a uniform sturgeon identification system are proposed to be the following: (i) designation of qualified reference laboratories at national levels in (re-) exporting and importing countries. These should be approved through a standardized testing procedure, for instance a ring test on blind samples. Registered laboratories should be published and disseminated and their accreditations should be subject to certain guarantees regarding quality, economic independence and scientific rigour. Operational procedures have to be determined and standardized among reference laboratories; (ii) establishment of reference collections that are accessible to the reference laboratories containing DNA analyses results and information on the location and availability of tissue samples. This is highly recommended as an important step towards a population identification system and indispensable for a general species identification system; (iii) creation of a website access to the reference collections containing the reference database information about genetic samples, comparable to NCBI, which provides background data: sample location; population information; citation; available genetic data; location of archival storage; currently treated and distributed caviar and status of analysis. This website should also be a forum for the exchange of knowledge on and experiences with identification systems, species and population status information, relevant scientific research, etc.; and (iv) the outcome of the trade identification tests should be made available to the reference laboratories for future reference. The universal caviar labelling system could incorporate an indication of the verification of the consignment. In view of the lack of knowledge and the great need to develop a uniform identification system for Acipenseriformes with regard to the importance of the international caviar trade, further scientific guidance and appropriate research is strongly recommended. Progress should be assessed and exchanged on a regular basis. [source] Use of RAPD and killer toxin sensitivity in Saccharomyces cerevisiae strain typingJOURNAL OF APPLIED MICROBIOLOGY, Issue 3 2005L. Corte Abstract Aims:, Two different strain characterization techniques, random amplified polymorphic DNA (RAPD) and killer toxin sensitivity (KTS), were compared to assess their typing performance using a set of 30 certified Saccharomyces cerevisiae strains. Methods and Results:, A sequential random resampling procedure was employed to subdivide the 32 descriptors in eight sets, in order to compare the differential performances of the two techniques with diverse number of characters. Results showed that RAPD performs better than killer, although the complete differentiation of the strains under study could be obtained only by combining profiles from the two techniques Conclusions:, The combination of different typing techniques was useful when discriminating similar organisms. In such cases, the introduction of a second typing technique can be more advantageous than increasing the number of characters obtained with a single method. Significance and Impact of the Study:, The distribution of among-strains pairwise distances and the relative performance of the two techniques has implications for the study of biodiversity, taxonomy and microbial ecology. [source] Evaluation of a modified IAT-gel with polyethylenglycol (PEG) addition method for red blood cell antibody identificationJOURNAL OF CLINICAL LABORATORY ANALYSIS, Issue 3 2004L. Gustafsson Abstract We aimed to evaluate whether a PEG-IAT method, modified for gel technique, could replace the two-stage enzyme method for routine identification of red blood cell (RBC) antibodies. A total of 161 selected patient samples were analyzed with the two-stage enzyme tube technique and the PEG-IAT in gel techniques. In 65 samples, identical antibody results were obtained by the two methods. An additional 28 antibodies were identified by either the PEG-IAT gel method or the enzyme method. Twenty antibodies were identified by the PEG-IAT gel method only (12 Rh antibodies, four anti-Kell, two anti-Fya, two anti-Jka), and eight antibodies by the enzyme method only (four Rh antibodies, one anti-K, one anti-Jka, two anti-Lea). The results in the remaining 68 samples were judged as nonspecific reactions, which were more common when the enzyme method was used. We concluded that the PEG-IAT in gel method identifies more RBC antibodies with less nonspecific reactions than the two-stage enzyme technique. However, no single method detected all clinical significant RBC antibodies. J. Clin. Lab. Anal. 18:165,169, 2004. © 2004 Wiley-Liss, Inc. [source] A systematic review of professional support interventions for breastfeedingJOURNAL OF CLINICAL NURSING, Issue 9 2008Leena Hannula PhD Objectives., The objectives of this systematic review were first, to describe how breastfeeding is professionally supported during pregnancy, at maternity hospitals and during the postnatal period. Secondly, to find out how effective interventions are in supporting breastfeeding. Background., Breastfeeding is an effective way to promote the health of infants. In many countries, the rates for breastfeeding remain lower than recommended. Many studies have examined breastfeeding promotion interventions; some of them are successful and some fail. It is important to find effective combinations of support. Design. Systematic review. Methods., Search of CINAHL, Medline and Cochrane Central Register databases were conducted for data collection. The search was limited to articles published in Finnish, Swedish and English between the year 2000 and March 2006, focusing on breastfeeding and breastfeeding support interventions. Two reviewers independently analysed 36 articles in the final analysis. Results., Interventions expanding from pregnancy to the intrapartum period and throughout the postnatal period were more effective than interventions concentrating on a shorter period. In addition, intervention packages using various methods of education and support from well-trained professionals are more effective than interventions concentrating on a single method. Conclusions., During pregnancy, the effective interventions were interactive, involving mothers in conversation. The Baby Friendly Hospital Initiative (BFHI) as well as practical hands off -teaching, when combined with support and encouragement, were effective approaches. Postnatally effective were home visits, telephone support and breastfeeding centres combined with peer support. Relevance to clinical practice., Professionals need breastfeeding education and support of their organisations to act as breastfeeding supporters. The BFHI -programme is effective and it would be wise to include the core components of the programme in breastfeeding promotion interventions. Mothers benefit from breastfeeding encouragement and guidance that supports their self-efficacy and feelings of being capable and empowered, and is tailored to their individual needs. [source] Models for the treatment of crystalline solids and surfacesJOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 13 2004Karl Jug Abstract Crystalline solids and surfaces have become a subject of growing interest. The difficulty of a comprehensive description of a variety of phenomena by a single method has led to the development of many models. These models can be classified as nonperiodic and periodic models. The former include free clusters, saturated clusters, and embedded clusters. The latter two models serve to remove the boundary effects of the free clusters. No perfect avoidance of such effects can be achieved in this way. The cyclic cluster model overcomes this difficulty in a natural way. It is periodic with a finite periodicity. An embedding can take into account a long-range effect in ionic crystals. Previous periodic approaches relied on the large unit cell model, which is related to the supercell approach. For perfect crystals the conventional unit cell approach is a well-known standard. However, its disadvantage is the unphysical periodicity of defects, which is avoided in the cyclic cluster model. The present article presents a description of these models together with selective applications to solid-state systems and surfaces. © 2004 Wiley Periodicals, Inc. J Comput Chem 13: 1551,1567, 2004 [source] Forecasting international bandwidth capabilityJOURNAL OF FORECASTING, Issue 4 2005Gary Madden Abstract M-competition studies provide a set of stylized recommendations to enhance forecast reliability. However, no single method dominates across series, leading to consideration of the relationship between selected data characteristics and the reliability of alternative forecast methods. This study conducts an analysis of predictive accuracy in relation to Internet bandwidth loads. Extrapolation techniques that perform best in M-competitions perform relatively poorly in predicting Internet bandwidth loads. Such performance is attributed to Internet bandwidth data exhibiting considerably less structure than M-competition data. Copyright © 2005 John Wiley & Sons, Ltd. [source] Current trends in quantitative proteomicsJOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 12 2009Monica H. Elliott Abstract It was inevitable that as soon as mass spectrometrists were able to tell biologists which proteins were in their samples, the next question would be how much of these proteins were present. This has turned out to be a much more challenging question. In this review, we describe the multiple ways that mass spectrometry has attempted to address this issue, both for relative quantitation and for absolute quantitation of proteins. There is no single method that will work for every problem or for every sample. What we present here is a variety of techniques, with guidelines that we hope will assist the researcher in selecting the most appropriate technique for the particular biological problem that needs to be addressed. We need to emphasize that this is a very active area of proteomics research,new quantitative methods are continuously being introduced and some ,pitfalls' of older methods are just being discovered. However, even though there is no perfect technique,and a better technique may be developed tomorrow,valuable information on biomarkers and pathways can be obtained using these currently available methods Copyright © 2009 John Wiley & Sons, Ltd. [source] Performance assessment in health care providers: a critical review of evidence and current practiceJOURNAL OF NURSING MANAGEMENT, Issue 8 2007KAREN E. STC. Aim, To evaluate methods of performance assessment through an international literature review and a survey of current practice. Background, Over the past two decades health care organizations have focussed on promoting high quality care in conjunction with retaining motivated staff. Cognisant of such initiatives, we sought to evaluate assessment methods for qualified staff according to their utility in the working environment. Methods, A systematic literature search was completed and each paper independently reviewed. All health care organizations in Northern Ireland submitted details of their performance assessments. Each was critically appraised using a utility index. Results, Performance was not universally defined. A broad range of assessments were identified, each method had advantages and disadvantages. Although many lacked rigorous testing, areas of good practice were also noted. Conclusions, No single method is appropriate for assessing clinical performance. Rather, this study endorses proposals for a multi-method strategy to ensure that performance assessment demonstrates all attributes required for effective nursing and midwifery practice. [source] Training the clinical eye and mind: using the arts to develop medical students' observational and pattern recognition skillsMEDICAL EDUCATION, Issue 3 2006Johanna Shapiro Introduction, Observation, including identification of key pieces of data, pattern recognition, and interpretation of significance and meaning, is a key element in medical decision making. Clinical observation is taught primarily through preceptor modelling during the all-important clinical years. No single method exists for communicating these skills, and medical educators have periodically experimented with using arts-based training to hone observational acuity. The purpose of this qualitative study was to better understand the similarities and differences between arts-based and clinical teaching approaches to convey observation and pattern recognition skills. Method, A total of 38 Year 3 students participated in either small group training with clinical photographs and paper cases (group 1), or small group training using art plus dance (group 2), both consisting of 3 2-hour sessions over a 6-month period. Findings, Students in both conditions found value in the training they received and, by both self- and instructor-report, appeared to hone observation skills and improve pattern recognition. The clinically based condition appeared to have been particularly successful in conveying pattern recognition concepts to students, probably because patterns presented in this condition had specific correspondence with actual clinical situations, whereas patterns in art could not be generalised so easily to patients. In the arts-based conditions, students also developed skills in emotional recognition, cultivation of empathy, identification of story and narrative, and awareness of multiple perspectives. Conclusion, The interventions studied were naturally complementary and, taken together, can bring greater texture to the process of teaching clinical medicine by helping us see a more complete ,picture' of the patient. [source] Small proportions: what to report for confidence intervals?,PHARMACOEPIDEMIOLOGY AND DRUG SAFETY, Issue 4 2005Hilde Tobi Abstract Purpose It is generally agreed that a confidence interval (CI) is usually more informative than a point estimate or p -value, but we rarely encounter small proportions with CI in the pharmacoepidemiological literature. When a CI is given it is sporadically reported, how it was calculated. This incorrectly suggests one single method to calculate CIs. To identify the method best suited for small proportions, seven approximate methods and the Clopper,Pearson Exact method to calculate CIs were compared. Methods In a simulation study for 90-, 95- and 99%CIs, with sample size 1000 and proportions ranging from 0.001 to 0.01, were evaluated systematically. Main quality criteria were coverage and interval width. The methods are illustrated using data from pharmacoepidemiology studies. Results Simulations showed that standard Wald methods have insufficient coverage probability regardless of how the desired coverage is perceived. Overall, the Exact method and the Score method with continuity correction (CC) performed best. Real life examples showed the methods to yield different results too. Conclusions For CIs for small proportions (,,,,0.01), the use of the Exact method and the Score method with CC are advocated based on this study. Copyright © 2005 John Wiley & Sons, Ltd. [source] Relationship between health services outcomes and social and economic outcomes in workplace injury and disease: Data sources and methods,AMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 3 2001Cam Mustard ScD Abstract Background Understanding the mediating role of health care in mitigating social, economic and occupational role disability is a complex task. Methods No single method of research will be successful in addressing all elements of this NORA research priority area. In this paper, we argue that research methods are needed which have the following components: (1) the detailed measurement of therapeutic intervention and the impacts of this intervention on clinical and functional health status using study designs which rule out competing explanations, (2) a longitudinal follow-up component which measures social, economic, and occupational role function following the conclusion of therapy, and (3) a commitment to execute studies across multiple settings to observe the variations in health care and in social and occupational role function that arise as a result of differences in labor market factors and employer and government policies. Conclusions More comprehensive portraits of the longitudinal trajectory of individual workers, social, economic and occupational role function following an occupational injury or illness will have significance for a large number of policy sectors. Am. J. Ind. Med. 40:335,343, 2001. © 2001 Wiley-Liss, Inc. [source] Probabilistic forecasting from ensemble prediction systems: Improving upon the best-member method by using a different weight and dressing kernel for each memberTHE QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, Issue 617 2006Vincent Fortin Abstract Ensembles of meteorological forecasts can both provide more accurate long-term forecasts and help assess the uncertainty of these forecasts. No single method has however emerged to obtain large numbers of equiprobable scenarios from such ensembles. A simple resampling scheme, the ,best member' method, has recently been proposed to this effect: individual members of an ensemble are ,dressed' with error patterns drawn from a database of past errors made by the ,best' member of the ensemble at each time step. It has been shown that the best-member method can lead to both underdispersive and overdispersive ensembles. The error patterns can be rescaled so as to obtain ensembles which display the desired variance. However, this approach fails in cases where the undressed ensemble members are already overdispersive. Furthermore, we show in this paper that it can also lead to an overestimation of the probability of extreme events. We propose to overcome both difficulties by dressing and weighting each member differently, using a different error distribution for each order statistic of the ensemble. We show on a synthetic example and using an operational ensemble prediction system that this new method leads to improved probabilistic forecasts, when the undressed ensemble members are both underdispersive and overdispersive. Copyright © 2006 Royal Meteorological Society. [source] Evaluation of Immunosuppressive Regimens in ABO-Incompatible Living Kidney Transplantation,Single Center AnalysisAMERICAN JOURNAL OF TRANSPLANTATION, Issue 4 2007H. Ishida Several protocols allow the successful ABO incompatible living-related kidney transplantation (ABO-ILKT), yet no single method has emerged as the best. We have made several substantial changes to our ABO-ILKT protocol over the past decade and a half and have attempted to determine whether the changes in immunosuppressive agents have resulted in a better outcome. We used methylprednisolone (MP), cyclosporine (CsA), azathioprine (AZ), antilymphocyte globulin (ALG) and deoxyspergualine (DSG) in the 105 cases of ABO-ILKT (group 1) between 1989 and 1999, and MP, tacrolimus (FK506), mycophenolate mofetil (MMF) in the 117 cases of ABO-ILKT (group 2) between 2000 and 2004. We compared the patient and graft survival rates as well as the incidence rate of acute rejection in these two eras, when different regimens were used. There were significant differences in the 1- and 5-year graft survival rates between groups 1 and 2 (1-year: 78% in group 1 vs. 94% in group 2; 5-year: 73% in group 1 vs. 90% in group 2, p = 0.008). Also, a higher incidence rate of acute rejection was significantly observed in group 1 (50/105, 48%) than in group 2 (18/117, 15%) (p < 0.001). We conclude that the FK/MMF combination regimen provides excellent graft survival results in ABO-ILKT. [source] Communicating breast cancer treatment complication risks: When words are likely to failASIA-PACIFIC JOURNAL OF CLINICAL ONCOLOGY, Issue 3 2009Peter H GRAHAM Abstract Aim: The aim of the present study was to describe women's preferences for the quantification of the risk of a serious complication after regional nodal radiotherapy for breast cancer and women's interpretation of a range of descriptive terms. Methods: A cross-sectional survey was conducted to elicit risk expression preferences and interpretation of words commonly used to describe the risk or frequency of a complication. Two hundred and sixty-two women who had experienced breast-only radiotherapy for early breast cancer at a Sydney teaching hospital were recruited for the survey. Results: The most preferred single method of expression of a risk is descriptive words, for example "uncommon" (52%), followed by percentages (27%) and numbers, for example 1 in 100 (21%). Lower education levels, more advanced cancer stage and older age increase the preference for descriptive words. When considering a serious complication of treatment, such as loss of the function of an arm, the modal interpretation of the descriptors "sometimes" was 1/100 (36% of women), "uncommon" was 1/1000 (35%), "very uncommon" was 1/10 000 (40%), "rare" was 1/10 000 (58%) and "very rare" was 1/10 000 (51%). However, the range of interpretations and the consistent assignment of extremely low frequencies of risk generally render descriptive words without numerical quantification inadequate for informed consent. Conclusion: Although risks of side-effects are often described in words such as common, uncommon and rare, qualification should be provided with numerical values to ensure better understanding of risk. [source] A method for determination of fruit-derived ascorbic, tartaric, oxalic and malic acids, and its application to the study of ascorbic acid catabolism in grapevinesAUSTRALIAN JOURNAL OF GRAPE AND WINE RESEARCH, Issue 3 2009V.J. MELINO Abstract Background and Aims:, The majority of the acidity of a grapevine (Vitis vinifera L.) berry is a result of the accumulation of l -tartaric (TA) and l -malic acids (MA). TA is synthesised from l -ascorbic acid (Asc, vitamin C), the metabolism of which is poorly characterised in grapevines. In a distinct pathway, oxalic acid (OA) is also formed from Asc degradation. The aim of this study was to develop a single method whereby the distribution of Asc and its catabolites from fruit and vegetative sources could be determined. Methods and Results:, Effective recoveries of total Asc, TA, OA and MA were achieved with this extraction method, while chromatographic separation was accomplished with reversed-phase high-performance liquid chromatography (RP-HPLC). These results demonstrate that Asc and its catabolites TA and OA rapidly accumulate in immature berries, and that the Asc to dehydroascorbate ratio increases with berry maturity. Conclusions:, A method for the simultaneous analysis of Asc, TA, OA and MA in fruits is provided; moreover, we have demonstrated its use to study their distribution in fruits, rachis, leaves and roots. Significance of the Study:, This method enables accurate monitoring of the accumulation of Asc, permitting further research towards understanding acid metabolism during berry ripening. [source] On Strategy and Management Control: The Importance of Classifying the Strategy of the BusinessBRITISH JOURNAL OF MANAGEMENT, Issue 3 2000Magnus Kald The point of departure for this paper is a number of contingency-theory studies on the relationship between business strategy and the design and use of management control. In these studies strategy has been operationalized in different ways , a major reason why the findings are ambiguous and difficult to integrate. Thus there is a strong need for a common frame of reference for classifying business strategy. In view of the multifaceted nature of the concept of strategy, however, it is neither desirable nor possible to arrive at a single method of classification that would be appropriate in all situations. Rather, the task is to integrate different strategic variables such as strategic pattern, strategic position and strategic mission. In this paper we show how these three variables may be assumed to influence, and be influenced by, what characterizes changes in strategy and how business units manage their product offerings. Unlike most previous studies in the field, this paper discusses how the strategic variables taken together may be assumed to influence the classification of strategy and thus the design and use of the management-control system. Our deductive analysis, and the hypotheses used in connection with it, show that studies which consider only one strategic variable may lead to erroneous conclusions about the relationship between strategy and management control. [source] Theoretical investigation of charge transfer excitation and charge recombination in acenaphthylene,tetracyanoethylene complexINTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 1 2003Hai-Bo Yi Abstract Ab initio calculations were performed to investigate the charge separation and charge recombination processes in the photoinduced electron transfer reaction between tetracyanoethylene and acenaphthylene. The excited states of the charge-balanced electron donor,acceptor complex and the singlet state of ion pair complex were studied by employing configuration interaction singles method. The equilibrium geometry of electron donor,acceptor complex was obtained by the second-order Møller,Plesset method, with the interaction energy corrected by the counterpoise method. The theoretical study of ground state and excited states of electron donor,acceptor complex in this work reveals that the S1 and S2 states of the electron donor,acceptor complexes are excited charge transfer states, and charge transfer absorptions that corresponds to the S0 , S1 and S0 , S2 transitions arise from ,,,* excitations. The charge recombination in the ion pair complex will produce the charge-balanced ground state or excited triplet state. According to the generalized Mulliken,Hush model, the electron coupling matrix elements of the charge separation process and the charge recombination process were obtained. Based on the continuum model, charge transfer absorption and charge transfer emission in the polar solvent of 1,2-dichloroethane were investigated. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem 94: 23,35, 2003 [source] | |||||||||||||||||||||||||