bluuebunny/crossref_metadata_2025 huggingface dataset:
Explanations for the provision‐utilisation gap in work‐life policy
Authors: McDonald Paula , Brown Kerry , Bradley Lisa
Published: March 2005

Purpose

Organisational work‐life policies and programs allow employees to have greater control over how, when and where they work but these policies are often under‐utilised, particularly by men and career‐oriented employees. In what is largely an atheoretical area of literature, the paper aims to theoretically integrate the empirical literature related to the uptake of organisational work‐life policies.

Design/methodology/approach

The paper links three related areas of literature: the associations between work‐life policies and individual/organisational outcomes; explanations for the low uptake of work‐life policies in many organisations; and preliminary studies which have explored organisational culture and its relationship to work‐life policies. These literatures are integrated to develop a five‐dimensional construct, “organisational work‐life culture”, for testing in future research.

Findings

It is suggested that the following five dimensions underlie this aspect of organisational life: lack of managerial support for work‐life balance; perceptions of negative career consequences; organisational time expectations; the gendered nature of policy utilisation; and perceptions of unfairness by employees with limited non‐work responsibilities.

Practical implications

The development and validation of the organisational work‐life culture construct requires further research and may result in specific organisational strategies and policies which address the barriers to work‐life policy utilisation.

Originality/value

Based on existing empirical evidence, the paper suggests an original theoretical proposition: that organisational work‐life culture is underpinned by five dimensions and explains much of the provision‐utilisation gap in work‐life policy.
Remarks on metadata management
Authors: Westbrooks Elaine L.
Published: March 2005

Purpose

As digital resources proliferate, libraries plan to grant easy access to a distributed set of resources from one single entry point inside and outside the OPAC. The quest to manage the metadata about these resources becomes more important than ever. Thus, the term, “metadata management” is being used by various communities creating spatial data, enterprise applications, data warehouses, legacy environments, and bibliographic data. Unfortunately, metadata management is sparsely mentioned in the traditional information technology journals, grey literature, information technology company web sites, and the library science literature. The purpose of this viewpoint is to examine the limited use of the term metadata management in the library community and to introduce a new definition of it.

Design/methodology/approach

This viewpoint examines the limited use of the term metadata management in the library community and introduces a new definition of it.

Findings

Although the proposed definition captures the activities that libraries should be engaged as they provide access to millions of resources, this definition should constantly be examined as new technologies emerge, personnel change, and financial resources diminish.

Originality/value

The author's definition is a good start; however, to get to the complete definition of metadata management, a more comprehensive look at the workflow and procedures that exist in libraries for managing metadata is necessary.
A corporate executive's short guide to leading nonprofits
Authors: Taliento Lynn , Silverman Les
Published: March 2005

Purpose

By introducing business people to the frustrations of leadership roles in nonprofits and showing how executives with corporate experience have dealt with these challenges, the authors provide a guide for volunteers who serve as board members, executives, donors, consultants or partners in the nonprofit sector.

Design/methodology/approach

McKinsey & Company consultants interviewed executives who have served as both corporate and nonprofit leaders.

Findings

Corporate executives working with nonprofits need to take the time to get to know the organization and all its stakeholders before proposing any new practices or initiatives. They should avoid unilateral decisions – instead involving board, staff and key stakeholders as appropriate.

Research limitations/implications

The sample interviewed was small, about a dozen top executives. However, as more corporate executive take leadership positions in nonprofits, there will be an opportunity to survey a much larger sample.

Practical implications

Business leaders serving as nonprofit board members will better understand their nonprofit roles. Donors will learn to use their financial clout to improve nonprofit performance. Cross‐sector partnerships – which are central to addressing society's most intractable problems – can anticipate and solve roadblocks caused by the nonprofit sector's different culture and demands. Top business executives will gain a better understanding of what makes the nonprofit world tick.

Originality/value

This article assesses the factors for nonprofit sector leadership success based on the first‐hand experience of top executives who have run major corporations.
Strategies in the broadband cable TV industry: the challenges for management and technology innovation
Authors: McGrail Mike , Roberts Bob
Published: March 2005

Purpose

To examine the status and strategies of the broadband cable TV industry on a world‐wide basis.

Design/methodology/approach

Data were gathered through a review of the literature and a series of one‐on‐one interviews with key industry executives, and with consultant analysts dedicated to the industry. The SWOT technique proved useful in analyzing the organizational environment; value chain analysis was used to understand the value‐generating components of the core activities; a Boston Consulting Group product portfolio matrix identified the nature of the products offered by the industry.

Findings

Four forces were identified which had impacted significantly on the industry. These were the rise of the internet, the experience of competition for telephony services, the arrival of satellite TV, and a persistent image of poor customer service. The paper observes that recent trading results have revealed very little evidence that modified strategies are making a significant improvement in the industry's overall competitive position.

Research limitations/implications

Limitations relate to scope of companies chosen for the research and by the dependence on the mainly qualitative nature of the data. Further research is required to review innovation in the light of continuing technology developments and mergers within the industry.

Practical implications

More radical innovation is required so that the industry can successfully address its current difficulties whilst simultaneously preparing itself for future competition.

Originality/value

The interview data when submitted to a strategy framework formulation exercise enabled the environmental situation of the industry to be understood and the identification of the critical success factors to achieve strategic objectives.
Privacy within in‐car systems
Authors: Rodríguez Casal Carlos
Published: March 2005

Purpose

The purpose of this paper is to call for integrated regulation for in‐car systems to ensure privacy and prevent citizens from having to choose between accepting the loss of privacy or losing out on services.

Design/methodology/approach

This paper highlights the ways in which in‐car communications systems can contribute to the web of surveillance that is beginning to pervade society. More and more frequently, intelligent transportation systems compute location data, in‐car services for drivers and passengers are becoming more popular and in‐car systems are incorporating other control features that may threaten privacy. In particular this study describes the existing regulations regarding location, and the advisability of allowing access to electronic health records in emergencies.

Findings

The study presents different threats to privacy within telematics and raises concerns about the financial value of the aggregated information. It recommends that not only the user's location information but also the user's health records be transferred to emergency services.

Originality/value

These new views on telematics data processing should be considered by stakeholders and policy makers to ensure security and services to the citizens.
Business process design: flexible modelling with multiple levels of detail
Authors: Baldwin Lynne P. , Eldabi Tillal , Paul Ray J.
Published: March 2005

Purpose

Most manufacturing processes tend to involve more than one level of detail at the design phase. These often consist of a higher level that represents the building‐blocks of the firm and a lower level that represents a more detailed structure of the process. When designing such processes, this type of structure is difficult to capture without some form of modelling. In such cases simulation can be used to help overcome this problem. This paper presents an investigation of simulation packages.

Design/methodology/approach

These simulation packages were investigated regarding their abilities to model business processes related to manufacturing systems.

Findings

The research findings suggest that no one simulation package currently available can alone offer sufficiently flexible facilities for the variable detailed modelling of manufacturing systems design.

Originality/value

The paper relates to one specific design framework called manufacturing system design (MSD). It defines the higher level of detail as the conceptual modelling level and the lower level as the detailed design level. A four‐step framework is proposed, and it is argued that this may better deal with problems of detail variability.
Determining the ERP package‐selecting criteria
Authors: Baki Birdoğan , Çakar Kemal
Published: March 2005

Purpose

To determine what criteria are used in enterprise resource planning (ERP) selection process and what criteria are the most important for firms.

Design/methodology/approach

Through an extensive literature review, 15 selection criteria for the ERP selection process were identified and two were added after initial interviews. A questionnaire including these criteria was formed to secure data from companies. A single informant method was used for each company. To measure the importance of various critical factors a five‐point Likert scale was used in the questionnaire.

Findings

Fit with parent/allied organisation systems is identified as the most important selection criterion. Cross‐module integration, compatibility between other systems, and references of the vendor are identified important factors respectively. Statistically significant differences were also determined between companies using MRP/MRPII versus those using own or no program for “better fit with organisational structure” and “fit with parent/allied organisational systems” criteria.

Research limitations/implications

The effect of each selection criterion on ERP implementations failure rates is still to be investigated.

Practical implications

Useful information about selection criteria on ERP systems for both vendors and firms planning to use these systems.

Originality/value

Two new selection criteria were proposed for the ERP system selection process and some important differences between the criteria used by firms from developed countries and developing countries are determined.
Perception on information and communication technology perspectives in logistics
Authors: Pokharel Shaligram
Published: March 2005

Purpose

Logistics companies have benefited from the use of information and communications technology (ICT) in their business processes. Although ICT is being promoted in the Singapore logistics industry, details on status and perception towards ICT are not well‐known. Therefore, in order to understand ICT penetration, a study is necessary.

Design/methodology/approach

In this paper, the current status of ICT use in warehouse and transportation service providers obtained through a sample survey is reported. A framework is adopted to assess the perception of logistics companies towards ICT.

Findings

The results show that most of the logistics companies use ICT but their level and type depend mainly on the size of the company and the availability of technology. Logistics companies in Singapore provide services to more than one industry type and, in most cases, one logistics company provides multiple logistics functions. These companies consider efficiency, cost savings, reduced data entry error and increased customer service level as opportunities from ICT. The analysis of perception indicates that the use of ICT in Singapore is perceived positively with the increase in size of a company but is indifferent regarding the type of industry covered and the type of service offered by the logistics companies.

Originality/value

This is a comprehensive study to understand the status of ICT in logistics in Singapore. An understanding of motivators and barriers on ICT can help the decision makers in devising better policies and programs, if required, to increase ICT penetration. The result also gives an indication as to the level of business fulfillment that can be provided by the logistics industry in Singapore.
Predictors of outcome among high functioning children with autism and Asperger syndrome
Authors: Szatmari P. , Bryson S.E. , Boyle M.H. , Streiner D.L. , Duku E.
Published: March 2005

Background:  The objective of this paper is to assess the extent to which measures of cognitive abilities taken in an inception cohort of young high functioning children with autism and Asperger syndrome predict outcome roughly two and six years later.

Method:  Children who received a diagnosis of autism or Asperger syndrome (AS) and who had a nonverbal IQ score in the ‘non‐retarded’ range were included in the inception cohort. Measures of language and nonverbal skills were taken when the children were 4–6 years of age and outcome assessments were completed when the children were 6–8 and 10–13 years of age. The three outcome measures consisted of scales of adaptive behaviours in socialisation and communication and a composite measure of autistic symptoms (abnormal language, abnormal body and object use, difficulties relating to others, sensory issues and social and self‐help difficulties).

Results:  The explanatory power of the predictor variables was greater for communication and social skills than for autistic symptoms. The power of prediction was stable over time but did differ by PDD subtype. In general, the association between language skills and outcome was stronger in the autism group than in the AS group.

Conclusions:  These results support the emphasis of early intervention programmes on language but more work needs to be done on understanding variables that influence outcome in social skills and autistic behaviours, particularly in those with AS.
Sequence‐sensitive subcomponents of P300: Topographical analyses and dipole source localization
Authors: Jentzsch Ines , Sommer Werner
Published: March 2005

P300 amplitude and reaction time (RT) are strongly affected by the sequence of events preceding the eliciting stimulus. Sommer, Leuthold and Soetens (1999) found that robust sequential effects in P300 amplitude could be dissociated from more variable sequential effects in RTs. However, global changes in P300 amplitude and topography gave rise to the suggestion that sequential effects are specific for a subcomponent of P300 that is separate from and anterior to the classical parietal P300. Here, confirming evidence for dissociable subcomponents of P300 is reported from two experiments. Independent component analysis separated a centrally distributed sequence‐sensitive subcomponent from a more parietal subcomponent. Subsequent dipole source analysis indicated a deep mesial source for the sequence‐sensitive subcomponent. Overlap with reafferent somatosensory activity appears to be responsible for an apparent lateralization of this component towards the hemisphere ipsilateral to the responding hand.
Attentional stages of information processing during a continuous performance test: A startle modification analysis
Authors: Hazlett Erin A. , Dawson Michael E. , Schell Anne M. , Nuechterlein Keith H.
Published: March 2005

This study of 31 college students employed the startle eye‐blink modification (SEM) technique to index both early and later stages of attentional processing during a memory‐load version of the Continuous Performance Test (CPT). Participants viewed a series of digits and pressed a button after the digit 7 of each 3–7 sequence. A startling noise burst was presented either 120 or 1,200 ms following three preselected prepulses: target (3), nontarget (non‐3 and non‐7 digits), or target plus distractor (3 and simultaneous tone distractor). Greater startle inhibition occurred 120 ms following target and target‐plus‐distractor prepulses compared with nontargets, indicating early selective attention. No difference was observed between SEM during target and target‐plus‐distractor prepulses, suggesting the distractor was effectively ignored. At 1,200 ms, the three prepulse types produced nondifferential inhibition, suggesting that modality‐specific selective attention occurs in anticipation of the presentation of the next CPT prepulse. These findings indicate that SEM distinguishes between different early selective attention and later anticipatory attention subprocesses underlying the CPT.
Four‐week test‐retest stability of individual differences in the saccadic CNV, two saccadic task parameters, and selected neuropsychological tests
Authors: Klein CH. , Berg P.
Published: March 2005

The aim of the present study was the comparative assessment of the 4‐week test‐retest stabilities of the saccadic CNV (sCNV) and saccadic reaction times (SRT) during the execution of pro‐ and antisaccades, as well as the stability of RT during execution of two neuropsychological tests of alertness and S‐R incompatibility. Prosaccades were elicited under the 200‐ms gap and overlap conditions, antisaccades under the overlap condition (64 trials each). The EEG was recorded from 25 channels with a DC amplifier (MES, Munich). Data of 20 healthy participants were statistically analyzed. We found high test‐retest correlations for all SRT (.76 ≤rtt≤ .88) and neuropsychological (.62 ≤rtt≤ .88) measures. For the sCNV, coefficients ranging between .58 (pro/gap) and .77 (anti/overlap) were obtained. Whereas SRT were significantly faster during the second than during the first session, group means for the saccadic CNV were stable across the sessions. Our results suggest high 4‐week stability of individual differences in SRT, and moderate to good stabilities of saccadic CNV amplitudes. Our results recommend these “traitlike” measures to be used in individual differences research.
Dispersal and the metapopulation paradigm in amphibian ecology and conservation: are all amphibian populations metapopulations?
Authors: Alex Smith M. , M. Green David
Published: March 2005

Amphibians are frequently characterized as having limited dispersal abilities, strong site fidelity and spatially disjunct breeding habitat. As such, pond‐breeding species are often alleged to form metapopulations. Amphibian species worldwide appear to be suffering population level declines caused, at least in part, by the degradation and fragmentation of habitat and the intervening areas between habitat patches. If the simplification of amphibians occupying metapopulations is accurate, then a regionally based conservation strategy, informed by metapopulation theory, is a powerful tool to estimate the isolation and extinction risk of ponds or populations. However, to date no attempt to assess the class‐wide generalization of amphibian populations as metapopulations has been made. We reviewed the literature on amphibians as metapopulations (53 journal articles or theses) and amphibian dispersal (166 journal articles or theses for 53 anuran species and 37 salamander species) to evaluate whether the conditions for metapopulation structure had been tested, whether pond isolation was based only on the assumption of limited dispersal, and whether amphibian dispersal was uniformly limited. We found that in the majority of cases (74%) the assumptions of the metapopulation paradigm were not tested. Breeding patch isolation via limited dispersal and/or strong site fidelity was the most frequently implicated or tested metapopulation condition, however we found strong evidence that amphibian dispersal is not as uniformly limited as is often thought. The frequency distribution of maximum movements for anurans and salamanders was well described by an inverse power law. This relationship predicts that distances beneath 11–13 and 8–9 km, respectively, are in a range that they may receive one emigrating individual. Populations isolated by distances approaching this range are perhaps more likely to exhibit metapopulation structure than less isolated populations. Those studies that covered larger areas also tended to report longer maximum movement distances – a pattern with implications for the design of mark‐recapture studies. Caution should be exercised in the application of the metapopulation approach to amphibian population conservation. Some amphibian populations are structured as metapopulations – but not all.
Effects of landscape structure on the invasive spread of black cherry Prunus serotina in an agricultural landscape in Flanders, Belgium
Authors: Deckers Bart , Verheyen Kris , Hermy Martin , Muys Bart
Published: March 2005

Analysing invasive spread from a landscape ecological perspective forms an important challenge in plant invasion ecology. The present study examines the effects of landscape structure on the spatial and temporal dynamics of an expanding black cherry Prunus serotina population within a rural landscape in Flanders, Belgium, carrying a dense network of interconnected hedgerows. The study area, 251 ha in size, harboured a total of 2962 P. serotina individuals. The population was characterised by a negative exponential age distribution, a high growth rate and an early and continuous reproduction throughout the species’ life cycle. The historical rate of spread of the species through the hedgerow network progressively increased with time, especially during the last decade. Spatial point pattern analysis revealed that the individuals had a significantly clustered distribution pattern and were spatially aggregated around seed sources, hedgerow intersections and roosting trees. Logistic regression analysis confirmed the effect of landscape structure on P. serotina occurrence, suggesting directional long distance dispersal by avian dispersal vectors, resulting in a differential seed pressure throughout the hedgerow network due to the preference of dispersing birds for roosting in structurally rich hedgerow with large trees near hedgerow intersections. Hence, the distribution of P. serotina in agricultural landscapes was strongly mediated by dispersal processes. Furthermore, decreasing spatial aggregation along the species life cycle, with especially seedlings and saplings being significantly aggregated while adult individuals were mostly distributed at random, and a relative outward shift of seedling recruitment curves with time indicate density dependent mortality, probably caused by intraspecific competition.
Complementarity of epi‐ and endozoochory of plant seeds by free ranging donkeys
Authors: Couvreur Martine , Cosyns Eric , Hermy Martin , Hoffmann Maurice
Published: March 2005

Epizoochory and endozoochory are well‐recognized long‐distance seed dispersal mechanisms, yet their relative importance has hardly been studied before. Here, epi‐ and endozoochory were compared on donkeys foraging in a species‐rich 100 ha coastal dune ecosystem, through in vitro germination of zoochorous material obtained by fur brushing and dung collection. We identified 6675 seedlings of 66 plant species, covering 20% of the species recorded in the study area. Of the 66 species, only 16 occurred in both epi‐ and endozoochory samples, demonstrating the complementarity of both dispersal mechanisms. The species composition in the zoochory samples reflected a strong seasonality, and seedling numbers were partly correlated with species abundance in the study area. The non‐zoochorously dispersed species in the study area differed from the zoochorous species in seed size and weight, plant height, life span, dispersal strategy and seedbank persistence. Dispersal‐relevant plant traits were used to derive dispersal‐functional plant types for all species in the study area. Epizoochory showed to be more specific than endozoochory and was associated with a more narrow range of dispersal‐functional plant types.
Improved automated extraction and separation procedure for soil lipid analyses
Authors: Wiesenberg G. L. B. , Schwark L. , Schmidt M. W. I.
Published: March 2005

Analysis of soil lipids may contribute to an improved understanding of atmosphere to soil carbon fluxes, soil organic matter source differentiation and pollutant accumulation. Soil lipids, mostly originating from plants and microorganisms, have traditionally been analysed by non‐automated extraction and separation methods, which produce several lipid fractions, operationally defined by polarity. Here we present a combination of fast, automated and reproducible techniques, adopted from organic geochemical studies, for preparative separation of individual soil lipid fractions with increasing polarity. These techniques involve commercially available instruments, including accelerated solvent extraction and a two‐step automated medium‐pressure liquid chromatography procedure. The method yields eight lipid fractions consisting of five fractions fully amenable to gas chromatography/mass spectrometry (GC/MS) (aliphatic hydrocarbons, aromatic hydrocarbons, ketones, alcohols, carboxylic acids), and three fractions of highly polar or high molecular weight compounds (bases, very long‐chain wax esters (C40+), high polarity compounds) that were not measurable with GC/MS under standard conditions. We tested the method on five agricultural soils. Results show that (i) mass recoveries for the individual fractions are reproducible, (ii) within individual fractions compound distribution patterns are reproducible, as demonstrated for alkanes and carboxylic acids, and (iii) individual fractions represent distinct and clean compound classes, free of interfering substances detectable by GC/MS. Thus, automated separation can be a fast, effective and reproducible procedure for fractionation of complex mixtures of soil lipids into clean compound classes, directly suitable for a variety of molecular (e.g. GC/MS) and isotopic characterizations (e.g. gas chromatography coupled with isotope ratio monitoring mass spectrometry or accelerator mass spectrometry).
Review article: orofacial granulomatosis
Authors: Leão J. C. , Hodgson T. , Scully C. , Porter S.
Published: March 2005

Orofacial granulomatosis is an uncommon clinicopathological entity describing patients who have oral lesions characterized by persistent and/or recurrent labial enlargement, oral ulcers and a variety of other orofacial features, who on lesional biopsy have lymphoedema and non‐caseating granulomas. The aetiology of oral lesions with non‐caseating granulomas includes oral Crohn's disease (some patients with oral lesions will develop typical bowel symptoms of Crohn's disease in ensuing months to years), tooth‐associated infections, sarcoidosis and food or contact allergies. Treatment of orofacial granulomatosis is not reliably effective and may not be always necessary, although most patients do require some medical intervention.
Outcomes in elderly patients following surgery for colorectal cancer in the veterans affairs health care system
Authors: Rabeneck L. , Davila J. A. , Thompson M. , El‐Serag H. B.
Published: March 2005

Aim : To compare 30‐day and 5‐year mortality in elderly vs. younger patients following surgical resection for colorectal cancer.

Methods : A cohort study of patients admitted to VA hospitals with a new diagnosis of colorectal cancer who underwent surgical resection between October 1990 and September 2000. Cumulative survival rates (30‐day and 5‐year) were calculated from Kaplan–Meier estimates and adjusted risks of death were estimated using Cox proportional hazards models.

Results : We identified 34 888 individuals with a new diagnosis of colorectal cancer between October 1990 and September 2000, of whom 22 633 (65%) underwent surgical resection. The 30‐day mortality following resection for rectal and colon cancer, respectively, for patients <65 years was 2.1 and 2.8% compared with 4.9 and 5.6% for those ≥65 years. The 5‐year cumulative survival for rectal and colon cancer for patients <65 years was 54.0 and 57.6% compared with 44.5 and 46.6% for those ≥65 years. In patients ≥65 years with rectal or colon cancer, after adjustment, 30‐day mortality was 2 times greater and 5‐year mortality was 1 times greater than in younger patients.

Conclusions : Older age is an independent predictor of increased short‐term and long‐term mortality following surgery in patients with rectal and colon cancer.
Meta‐analysis: the effect of age on immunological response to hepatitis B vaccine in end‐stage renal disease
Authors: Fabrizi F. , Martin P. , Dixit V. , Bunnapradist S. , Dulai G.
Published: March 2005

Background : Patients on maintenance dialysis typically show a suboptimal immune response to hepatitis B virus vaccine compared with the non‐uraemic population. A variety of inherited or acquired factors have been implicated in this diminished response. Age‐associated changes in immune status may contribute to decreased vaccine efficacy in older individuals although contradictory results have been reported in individuals with normal kidney function.

Aims : To evaluate the relationship between age and immune response to hepatitis B vaccine in patients with end‐stage renal disease by performing a systematic review of the literature with a meta‐analysis of clinical trials.

Method : We used the random effects model of DerSimonian and Laird; sources of heterogeneity in effect estimates were explored by performing sensitivity analyses.

Results : We identified 17 clinical trials (1800 unique patients); six (35%) were controlled studies. Pooling of study results demonstrated a significantly decreased risk of response to hepatitis B vaccine among older dialysis patients (overall risk ratio: 0.74; 95% confidence intervals: 0.70–0.79). The P‐value was 0.0139 for our test of study heterogeneity. A lowered risk of response to hepatitis B vaccine persisted after exclusion of trials based on plasma‐derived vaccines; it was present even when ‘older’ individuals were defined as being as 50 years (RR: 0.85, 95% CI: 0.75–0.96) or more (cut‐off 60 years RR: 0.75; 95% CI: 0.66–0.85). An effect of age on seroprotection rate was present in all clinical reports, irrespective of the geographic origin of the study group: Europe (RR: 0.76; 95% CI: 0.70–0.83) North America (RR: 0.67; 95% CI: 0.60–0.74) or other countries (RR: 0.83; 95% CI: 0.71–0.97). Additional doses of vaccine did not appear to have an impact on RR of response by age.

Conclusions : Our meta‐analysis showed a clear association between older age and impaired response to hepatitis B virus vaccine in end‐stage renal disease patients. Such a relationship is biologically plausible. Vaccination schedules with adapted vaccine doses and frequent serum testing for loss of immunity against hepatitis B virus are recommended in elderly patients on maintenance dialysis.
Review article: is there a link between micronutrient malnutrition and Helicobacter pylori infection?
Authors: Salgueiro J. , Zubillaga M. , Goldman C. , Barrado A. , Martinez Sarrasague M. , Leonardi N. , Boccio J.
Published: March 2005

Helicobacter pylori causes a chronic gastric infection, which is usually life‐long. Many epidemiological studies have shown that this is probably one of the most common bacterial infections throughout the world involving 30% of the population living in developed countries and up to 80–90% of the population in developing regions. Concomitantly, developing regions also have high prevalence of micronutrient malnutrition. In the last few years, some studies have suggested that H. pylori infection may affect the homeostasis of different micronutrients including iron, vitamin B12, folic acid, α‐tocopherol, vitamin C and β‐carotene. In this article, we discuss the current scientific information of the effect that H. pylori infection may produce on micronutrient malnutrition.
Partitioning of organic carbon, aluminium and cadmium between solid and solution in soils: application of a mineral–humic particle additivity model
Authors: Lumsdon D. G.
Published: March 2005

The partitioning of chemical elements between the solid and solution phases in soil is fundamental in understanding processes such as leaching and bioavailability. Here I present a model in which the partitioning of Cd, Al and carbon in both mineral and organic soils can be simulated in the pH range 2–8. A two‐phase additivity approach simulates ion adsorption by the soils using a hydrous ferric oxide and humic type surface. A model for the partitioning of soil humic matter has also been developed in which the NICA–Donnan model calculates humic surface charge. Other key processes represented include mineral solubilization and solution speciation.

Methods for deriving model input parameters either from analytical data or by parameter optimization were used. Acid ammonium‐oxalate‐extractable Fe was used to estimate the amount of hydrous ferric oxide, and reactive humic substances were estimated by a scaled down version of the International Humic Substances Society method for the extraction of humic and fulvic acid. For initial calculation the 0.1 mHCl‐extractable Al was used to estimate reactive Al. Optimization of reactive Al improved the fit of both the total dissolved Al data and the adsorbed Cd. The model for the solid–solution partitioning of humic substances could simulate reasonably well the release of carbon in the pH range 4–8 for both the organic and mineral soils.
The locus coeruleus in schizophrenia: a postmortem study of noradrenergic neurones
Authors: Craven R. M. , Priddle T. H. , Crow T. J. , Esiri M. M.
Published: March 2005

Despite evidence for an abnormality of noradrenergic function in schizophrenia, it remains unclear whether the number of noradrenergic neurones is normal in patients with the disorder. In postmortem, formalin‐fixed tissue from 15 schizophrenic patients and 18 controls matched for  age  and  gender,  we  made  estimates  of  the  number and size of tyrosine‐hydroxylase‐immunoreactive cells in the locus coeruleus (LC). No significant difference was detected between these groups in the cross‐sectional area or diameter of immunoreactive cell profiles. Profile number was not significantly affected by gender, side of the brainstem (left or right), postmortem interval or time in formalin; however, the levels of immunoreaction product (optical density) correlated significantly with our profile counts, which were lower on average in the schizophrenic group. When optical density was included as a covariate in our comparison (a repeated‐measures analysis of variance) of schizophrenic and control cases, we found no difference between these groups in the number of neurones counted. An age‐related decrease in profile number was detected, but no effect of age on our estimates of cell size was apparent. Our results highlight the importance of accounting for potential confounding variables, including variations in the quality of immunostaining, in investigations of this type. The findings presented here concur with previous studies suggesting that noradrenergic dysfunction in schizophrenia is not associated with an anatomical abnormality at the level of the LC.
Primary hemostasis
Authors: McMichael Maureen
Published: March 2005

Objective: To review the current understanding of the mechanisms responsible for primary hemostasis and to give an overview of primary hemostatic syndromes in small animal patients. Current and future therapeutic options for dysfunction of primary hemostasis are discussed.

Data sources: A thorough search of the human and veterinary literature using the keywords platelets, primary hemostasis, von Willebrand factor (vWF), von Willebrand disease, aspirin, thromboxane, and aggregation, were performed. Databases searched included OVID Medline, Pubmed, and CAB abstracts.

Conclusions: Primary hemostasis occurs when platelets adhere to an injured or disrupted endothelial surface. Adherence is followed by activation, or the release of platelet granule contents. The agonists released from platelet granules recruit additional platelets and induce their activation and aggregation. Adhesion, activation, and aggregation are mediated by different receptors and ligands depending on the local blood flow conditions. vWF and adenosine diphosphate are the primary mediators of adhesion, activation, and aggregation under high shear conditions. During low shear conditions collagen, fibronectin, and laminin mediate adhesion, thromboxane A2 promotes activation, while aggregation is mediated by glycoprotein Ib‐IX‐V (GP Ib–IX–V) and fibrinogen. Knowledge of the receptor interactions during different blood flow conditions is crucial to the understanding of the various inhibitors of primary hemostasis available to clinicians.
Lewis Epitopes on Outer Membrane Vesicles of Relevance to Helicobacter pylori Pathogenesis
Authors: Hynes Sean O. , Keenan Jacqueline I. , Ferris John A. , Annuk Heidi , Moran Anthony P.
Published: March 2005

Background.  Helicobacter pylori extrudes protein‐ and lipopolysaccharide‐enriched outer membrane vesicles from its cell surface which have been postulated to act to deliver virulence factors to the host. Lewis antigen expression by lipopolysaccharide of H. pylori cells has been implicated in a number of pathogenic roles. The aim of this study was to further characterize the expression of lipopolysaccharide on the surface of these outer membrane vesicles and, in particular, expression of Lewis antigens and their association with antibody production in the host.

Materials and methods.  H. pylori strains were examined for outer membrane vesicle production using transmission electron microscopy and Lewis antigen expression probed using immunoelectron microscopy. Sera from patients were analyzed for cross‐reacting anti‐Lewis antibodies and, subsequently, absorbed using outer membrane vesicle preparations to remove the cross‐reacting antibodies.

Results.  The formation of outer membrane vesicles by H. pylori was observed in both in vitro and in vivo samples. Furthermore, vesicles were produced following culture in either liquid or solid medium by all strains examined. Moreover, we observed the presence of Lewis epitopes on outer membrane vesicles using immunoelectron microscopy and immunoblotting. Circulating anti‐Lewis antibodies were found in the sera of gastric cancer patients but not in the sera of H. pylori‐negative control subjects. Absorption of patient sera with outer membrane vesicles decreased the levels of anti‐Lewis autoantibodies.

Conclusions.  Our results demonstrate the ability of H. pylori to generate outer membrane vesicles bearing serologically recognizable Lewis antigens on lipopolysaccharide molecules which may contribute to the chronic immune stimulation of the host. The ability of these vesicles to absorb anti‐Lewis autoantibodies indicates that they may, in part, play a role in putative autoimmune aspects of H. pylori pathogenesis.
Clinical course, diagnostic findings and necropsy diagnosis in dyspneic cats with primary pulmonary parenchymal disease: 15 cats (1996–2002)
Authors: Sauvé Valérie , Drobatz Kenneth J. , Shokek Amy B. , McKnight Alexia L. , King Lesley G.
Published: March 2005

Objective:Correlate the necropsy diagnosis with the history, diagnostic findings, and clinical course of dyspneic cats with primary lung parenchymal disease.

Design:Retrospective study.

Setting:Matthew J. Ryan Veterinary Hospital of the University of Pennsylvania.

Animals:Client‐owned cats over 6 months of age hospitalized in the Intensive Care Unit (ICU) with a primary problem of respiratory distress that had pulmonary parenchymal disease on thoracic radiographs, and a complete necropsy.

Interventions:None.

Measurements and main results:Cats included were assigned into 2 groups based on the pulmonary histopathology: inflammatory (n=8) and neoplastic (n=7) disease. No statistical difference was found between the groups with regard to age, body weight, clinical signs, duration of clinical signs, physical examination findings, thoracic radiography, duration of hospitalization, treatment, and outcome. Cats with neoplasia had a statistically higher mean total white blood cell count (26.60 k/μL±10.41) than those with inflammatory lung disease (11.59 k/μL±4.49;P=0.026). Cats with bacterial or viral pulmonary disease had a significantly shorter median duration of illness (5 days, range 1–7 days) than all other cats (30 days, range 7–365 days;P=0.0042). Ultrasound guided pulmonary fine‐needle aspiration (FNA) provided an accurate diagnosis in 5/5 cases.

Conclusions:Forty‐seven percent of cats with pulmonary parenchymal disease had neoplasia. The clinical diagnosis was difficult to obtain ante‐mortem; lung FNA appeared to be the most helpful diagnostic tool in these cases.
Experiments on a model eye
Authors: Arell Antti , Kolari Samuli
Published: March 2005

A quantitative physics laboratory exercise, dealing with the optical features of the human eye, is described. An artificial eye model with approximately the real focal length was constructed. This is used as an object in direct and indirect ophthalmoscopy. The magnification of the retina by the eye lens is measured and (further) a corrective lens for refractive anomaly of the model is determined using both a subjective and an objective method. The accommodation effect of the observer’s eye is discussed and, at the end of the exercise, the observer examines the refractive power of his own eyes. This laboratory experiment has been designed for medical and biology students.
The Richtmyer memorial lecture—when is a particle?
Authors: Drell Sidney D.
Published: March 2005

Elementary particle concepts have evolved considerably in recent years. In particular, quarks are viewed as the basic constituents of subnuclear matter as probed by current experiments, although they themselves are not observed in isolation. This contrasts with earlier insistence on ’’seeing’’ our elementary particles, in particular the neutrino. The history of the neutrino is reviewed; the arguments for quarks are presented and discussed; the metaphysical origins of confined constituents in the writings of Greek and Roman philosophers are recalled; and the implications of permanently confined quarks for our view of elementary particles are considered.
An individualized laboratory system
Authors: Emkey William L.
Published: March 2005

This paper describes an individualized laboratory system used in an introductory physics course for science and engineering students. The system makes extensive use of video tapes, primarily for prelab instructions. The design and operation of the system are described, and the observations of both the instructor and the students are presented.
An interactive computer experiment for the introductory laboratory
Authors: Dowd John
Published: March 2005

The use of an interactive computer terminal in an introductory laboratory experiment is described. In addition to taking data with the equipment available in the laboratory, students are encouraged to use a computer terminal that has been programmed to act as their lab assistant in an experiment that leads to the student’s discovery of Stokes Law. This experiment is designed to be the students’ first introduction to the use of an interactive computer terminal.
Classical motion of a Morse oscillator
Authors: DeMarcus W. C.
Published: March 2005

The exact solution for a particle undergoing one-dimensional vibrations subject to the Morse potential is found in elementary terms. Thus an interesting and realistic nonlinear vibrator is available to check approximate methods in the teaching of dynamics or to demonstrate quantal properties of vibrating molecules via the correspondence principle since the exact Fourier series for the bound motion is also obtained.
Holography as a liberal arts physics course
Authors: Huang Jacob Wen-kuang
Published: March 2005

A liberal arts physics course for all majors interested in holography or nonscience majors interested in taking a physics course to satisfy the general education requirement has been developed. An outline of the course and some experience of offering it are given.
Net force of an ideal conductor on an element of a line of charge moving with extreme relativistic speed
Authors: Cawley Robert
Published: March 2005

A line of charge moving horizontally at an extreme relativistic speed through an evacuated space above an infinite plane ideal conductor experiences a net downward force, towards the conducting surface, which can be determined by the method of images. The image moves through the half-space occupied by the conductor, keeping pace with the charge pulse and positioned symmetrically with respect to the surface. Corresponding to the Green function approach, there is a viewpoint commonly employed in the analysis of relativistic problems which can lead to erroneous conclusions if one is not careful. We discuss the present problem from this point of view, first giving the incorrect arguments with the erroneous corresponding conclusions, and then the corrected picture.
Orbits of two-body problem from the Lenz vector
Authors: Caplan S. , Fuerstenberg H. , Hayes C. , Kane D. , Raboy S.
Published: March 2005

The orbits with reference to the center of mass of two bodies under mutual inverse square law interaction are obtained by use of the eccentricity vector which is equivalent to the Lenz vector within a numerical factor. The parameters and orientation of the orbits are given.
The classical Kepler problem in momentum space
Authors: Stickforth J.
Published: March 2005

Contrary to a current opinion, it is shown that the integration of a problem of classical mechanics can be as easy in momentum space as in configuration space. This is demonstrated with the Kepler problem, thus rendering a new very simple integration of it. The results strongly suggest that we consider both Laplace vectors, if dynamical invariance symmetries of the Kepler problem are to be studied.
The Gibbs paradox and quantum gases
Authors: Landsberg P. T. , Tranah D.
Published: March 2005

The sudden drop in the isothermal entropy of mixing when two ideal gases are made identical is analyzed for ideal quantum gases. For fermions of large reduced chemical potentials μ/kT this drop can be made arbitrarily small and this leads to a new resolution of the paradox.
A mechanical model for teaching quantum mechanics
Authors: Frederick Carl
Published: March 2005

The wave function ψ in quantum mechanics is a rather abstract quantity with which the physics student often has trouble. It is instructionally advantageous therefore, to have a mechanical model which can be described both by the quantum-mechanical formalism and also by derivations from ’’first principles.’’ It is shown that a particle traveling in a helical path gives rise to such a model.
Dumbbell model for the classical radiation reaction
Authors: Griffiths David J. , Szeto Ellen W.
Published: March 2005

In his treatise on electron theory, Lorentz showed that the classical radiation reaction is attributable to the breakdown of Newton’s Third Law within the structure of an accelerating charge. But Lorentz’s calculation, based on a spherical model, is so difficult as to obscure the underlying physical principle, and requires that the charge be instantaneously at rest. Noting that the answer must be structure independent, in the point-charge limit, we develop Lorentz’s theory in the context of a more tractable model: the dumbbell. We also compute the self-torque on a rotating dumbell.