bluuebunny/crossref_metadata_2025 huggingface dataset:
Aspergillus antigen testing in bone marrow transplant recipients
Authors: Williamson E C M , Oliver D A , Johnson E M , Foot A B M , Marks D I , Warnock D W
Published: July 2002

Aims—To assess the clinical usefulness of a commercial aspergillus antigen enzyme linked immunosorbent assay (ELISA) in the diagnosis of invasive aspergillosis (IA) in bone marrow transplant recipients, and to compare it with a commercial latex agglutination (LA) test.

Methods—In total, 2026 serum samples from 104 bone marrow transplant recipients were tested. These comprised 67 sera from seven patients who had died with confirmed IA, 268 sera from nine patients who had died with suspected IA, and 1691 sera from 88 patients with no clinical, radiological, or microbiological signs of IA.

Results—The ELISA was more sensitive than the LA test. All patients who were ELISA positive were also LA positive, and a positive LA result never preceded a positive ELISA. Twelve of 16 patients with confirmed or suspected IA were ELISA positive on two or more occasions, compared with 10 of 15 who were LA positive. ELISA was positive before LA in five patients (range, 2–14 days), and became positive on the same day in the remainder. Aspergillus antigen was detected by ELISA a median of 15 days before death (range, 4–233). Clinical and/or radiological evidence of IA was noted in all patients, and a positive ELISA was never the sole criterion for introduction of antifungal treatment. Two samples (one from each of two patients without IA) gave false positive results.

Conclusions—The aspergillus ELISA is a specific indicator of invasive aspergillosis if the criterion of two positive samples is required to confirm the diagnosis. However, the test is insufficiently sensitive to diagnose aspergillosis before other symptoms or signs are apparent, and hence is unlikely to lead to earlier initiation of antifungal treatment. It is therefore unsuitable for screening of asymptomatic patients at risk of invasive aspergillosis, but does have a useful role in confirming the diagnosis in symptomatic patients.
Ethical considerations in international HIV vaccine trials: summary of a consultative process conducted by the Joint United Nations Programme on HIV/AIDS (UNAIDS)
Authors: Guenter Dale , Esparza Jose , Macklin Ruth
Published: July 2002

Research that is initiated, designed or funded by sponsor agencies based in countries with relatively high social and economic development, and conducted in countries that are relatively less developed, gives rise to many important ethical challenges. Although clinical trials of HIV vaccines began ten years ago in the US and Europe, an increasing number of trials are now being conducted or planned in other countries, including several that are considered “developing” countries. Safeguarding the rights and welfare of individuals participating as research subjects in developing countries is a priority. In September, 1997, the Joint United Nations Programme on HIV/AIDS (UNAIDS) embarked on a process of international consultation; its purpose was further to define the important ethical issues and to formulate guidance that might facilitate the ethical design and conduct of HIV vaccine trials in international contexts. This paper summarises the major outcomes of the UNAIDS consultative process.
Ethical-legal problems of DNA databases in criminal investigation: Table 1
Authors: Guillén Margarita , Lareu María Victoria , Pestoni Carmela , Salas Antonio , Carracedo Angel
Published: July 2002

Advances in DNA technology and the discovery of DNA polymorphisms have permitted the creation of DNA databases of individuals for the purpose of criminal investigation.

Many ethical and legal problems arise in the preparation of a DNA database, and these problems are especially important when one analyses the legal regulations on the subject.

In this paper three main groups of possibilities, three systems, are analysed in relation to databases. The first system is based on a general analysis of the population; the second one is based on the taking of samples for a particular list of crimes, and a third is based only on the specific analysis of each case. The advantages and disadvantages of each system are compared and controversial issues are then examined. We found the second system to be the best choice for Spain and other European countries with a similar tradition when we weighed the rights of an individual against the public's interest in the prosecution of a crime.
Sham neurosurgery in patients with Parkinson's disease: is it morally acceptable?
Authors: Dekkers Wim , Boer Gerard
Published: July 2002

For a few decades, patients with Parkinson's disease (PD) have been treated with intracerebral transplantations of fetal mesencephalic tissue. The results of open trials have been variable. Double blind, placebo-controlled studies have recently been started in order to further investigate the efficacy of this new medical technique. In this paper we challenge the need for sham surgery in neurotransplantation research on PD patients. Considerations regarding the research subjects' informed consent, therapeutic misconception, the integrity of the human body, and the assessment of risks and benefits argue against sham surgery for patients with PD. Moreover, there is an alternative, less harmful mode of research that can provide the same or comparable scientific evidence. A plea is made for intrapatient research based on quantitative measurements of the patient's pre- and post-operative condition combined with similar research on a reference group of patients who have received the standard treatment.
The Freiburg approach to ethics consultation: process, outcome and competencies
Authors: Reiter-Theil Stella
Published: July 2002

The paper describes how ethics consultation can be valuable to health professionals, patients and their families in understanding and evaluating ethical values and their consequences in a particular situation. Ethics consultation as it is practised at the university hospital of Freiburg is a special professional service offered by members of an academic institution.

The practical approach and the goals are illustrated by a case study showing the difficulties of deciding about the limitation of intensive care medicine after heart surgery in the setting of maximum treatment. Here, the ethics consultation was initiated by the relatives of the patient who wanted a decision to withhold further life-sustaining treatment.

Following the experiences in Freiburg, it is concluded that clinical ethicists have to cover a variety of relevant fields of knowledge, need special analytical skills, and should have professional competence in counselling, including conflict mediation or crisis intervention.
Snapshots of five clinical ethics committees in the UK
Authors: Szeremeta M , Dawson John , Manning Donal , Watson Alan R , Wright Margaret M , Notcutt William , Lancaster Richard
Published: July 2002

Each of the following papers gives an account of a different UK clinical ethics committee. The committees vary in the length of time they have been established, and also in the main focus of their work. The accounts discuss the development of the committees and some of the ethical problems that have been brought to them. The issues raised will be relevant for other National Health Service (NHS) trusts in the UK that wish to set up such a committee.
The agony of agonal respiration: is the last gasp necessary?
Authors: Perkin R M , Resnik D B
Published: July 2002

Gasping respiration in the dying patient is the last respiratory pattern prior to terminal apnoea. The duration of the gasping respiration phase varies; it may be as brief as one or two breaths to a prolonged period of gasping lasting minutes or even hours. Gasping respiration is very abnormal, easy to recognise and distinguish from other respiratory patterns and, in the dying patient who has elected to not be resuscitated, will always result in terminal apnoea.

Gasping respiration is also referred to as agonal respiration and the name is appropriate because the gasping breaths appear uncomfortable and raise concern that the patient is suffering and in agony. Enough uncertainty exists about the influence of gasping respiration on patient wellbeing, that it is appropriate to assume that the gasping breaths are burdensome to patients. Therefore, gasping respiration at the end of life should be treated.

We propose that there is an ethical basis, in rare circumstances, for the use of neuromuscular blockade to suppress prolonged episodes of agonal respiration in the well-sedated patient in order to allow a peaceful and comfortable death.
Chlorination disinfection byproducts in water and their association with adverse reproductive outcomes: a review
Authors: Nieuwenhuijsen Mark J , Toledano Mireille B , Eaton Naomi E , Fawell John , Elliott Paul
Published: July 2002

OBJECTIVES AND METHODS

Chlorination has been the major disinfectant process for domestic drinking water for many years. Concern about the potential health effects of the byproducts of chlorination has prompted the investigation of the possible association between exposure to these byproducts and incidence of human cancer, and more recently, with adverse reproductive outcomes. This paper evaluates both the toxicological and epidemiological data involving chlorination disinfection byproducts (DBPs) and adverse reproductive outcomes, and makes recommendations for future research.

RESULTS AND CONCLUSIONS

Relatively few toxicological and epidemiological studies have been carried out examining the effects of DBPs on reproductive health outcomes. The main outcomes of interest so far have been low birth weight, preterm delivery, spontaneous abortions, stillbirth, and birth defects— in particular central nervous system, major cardiac defects, oral cleft, and respiratory, and neural tube defects. Various toxicological and epidemiological studies point towards an association between trihalomethanes (THMs), one of the main DBPs and marker for total DBP load, and (low) birth weight, although the evidence is not conclusive. Administered doses in toxicological studies have been high and even though epidemiological studies have mostly shown excess risks, these were often not significant and the assessment of exposure was often limited. Some studies have shown associations for DBPs and other outcomes such as spontaneous abortions, stillbirth and birth defects, and although the evidence for these associations is weaker it is gaining weight. There is no evidence for an association between THMs and preterm delivery. The main limitation of most studies so far has been the relatively crude methodology, in particular for assessment of exposure.

RECOMMENDATIONS

Large, well designed epidemiological studies focusing on well defined end points taking into account relevant confounders and with particular emphasis on exposure characterisation are ideally needed to confirm or refute these preliminary findings. In practice, these studies may be impracticable, partly due to the cost involved, but this is an issue that can be put right—for example, by use of subsets of the population in the design of exposure models. The studies should also reflect differences of culture and water treatment in different parts of the world. To identify the specific components that may be of aetiological concern and hence to fit the most appropriate exposure model with which to investigate human exposure to chlorinated DBPs, further detailed toxicological assessments of the mixture of byproducts commonly found in drinking water are also needed.
Longest held occupation in a lifetime and risk of disability in activities of daily living
Authors: Li Chung-Yi , Wu Shwu Chong , Wen Shi Wu
Published: July 2002

OBJECTIVES

To examine the association between the longest held occupation in a lifetime and risk of disability in activities of daily living (ADL) among elderly people (65 years and older) in northern Taiwan.

METHODS

A case-control design was used nested within two cohorts of a total of 2198 elderly people who had been followed up either between 1993 and 1997 or between 1996 and 1997. Cases were 360 elderly people with ADL disability within the study period. For each case, two sex matched controls were randomly sampled from the pool of elderly people free from ADL disability. Occupational data were collected through interviews conducted in 1997. Performed job contents were classified into occupational categories and occupation based social classes. Unconditional logistic regression techniques were used to estimate relative risk and 95% confidence intervals (95% CIs) of ADL disability.

RESULTS

Compared with people who were former legislators, government administrators, or business executives and managers, workers in agriculture, animal husbandry, forestry, or fishing (odds ratio (OR) 1.9, 95% CI 1.1 to 3.5) and workers in craft and related trades (OR 1.9, 95% CI 1.1 to 3.4) had significantly increased risks of subsequent ADL disability. Differential risks of ADL disability were found across social classes, with a significant dose-response trend in which unskilled blue collar workers had an 1.8 times higher risk of ADL disability than higher social classes of white collar workers.

CONCLUSIONS

After adjustment for education, there was still an inverse relation between risk of ADL disability and social class. Although total control for all the known risk factors for ADL disability among elderly people was impossible, the results tend to suggest a potential for an effect of longest held occupation in a lifetime on risk of ADL disability.
Mortality experience among employees at a hydrometallurgical nickel refinery and fertiliser complex in Fort Saskatchewan, Alberta (1954–95)
Authors: Egedahl R , Carpenter M , Lundell D
Published: July 2002

OBJECTIVE

To study the mortality experience of workers at a hydrometallurgical nickel refinery and fertiliser complex in Fort Saskatchewan, Alberta, Canada.

METHODS

A total of 1649 male employees of Sherritt International who worked for at least 12 continuous months during the years 1954 to 1978 at the Fort Saskatchewan, Alberta hydrometallurgical nickel refinery and fertiliser complex were followed up for an additional 17 years. Mortality was ascertained from the Canadian mortality data base maintained by Statistics Canada and covered the years 1954–95. Statistics were analysed with Monson's computer program.

RESULTS

Total mortality, when compared with the Canadian population, was significantly below expectation. Fewer deaths were found for circulatory disease, ischaemic heart disease, respiratory disease, neoplasms, digestive cancer, and accidents, poisonings, and violence. Among the 718 men in the group exposed to nickel, there were no deaths due to nasal cavity or paranasal sinus cancer. Fewer deaths were found for all causes, circulatory disease, ischaemic heart disease, neoplasms and digestive cancer. Lower death rates were observed than expected for respiratory malignancies and cancer of the bronchus and lung.

CONCLUSION

No association was found in this study between exposure to nickel concentrate or metallic nickel in the hydrometallurgical refining process and the subsequent development of respiratory cancer.
An epidemiological study of the respiratory health of workers in the European refractory ceramic fibre industry
Authors: Cowie H A , Wild P , Beck J , Auburtin G , Piekarski C , Massin N , Cherrie J W , Hurley J F , Miller B G , Groat S , Soutar C A
Published: July 2002

OBJECTIVES

To investigate possible relations between respiratory health and past airborne exposure to refractory ceramic fibres (RCFs) and respirable dust in workers at six European factories, studied previously in 1987.

METHODS

The target population comprised all current workers associated with RCF production, plus others who had participated in 1987 “leavers”. Information was collected on personal characteristics, chest radiographs, lung function, respiratory symptoms, smoking, and full occupational history. Regression analysis was used to study relations between indices of health of individual workers and of cumulative exposure to airborne dust and fibres, and likely past exposure to asbestos.

RESULTS AND DISCUSSION

774 workers participated (90% of current workers, 37% of leavers). Profusion of small opacities in exposed workers (51% 0/1+; 8% 1/0+) was similar to that among an unexposed control group but higher than in new readings of the 1987 study films (11% 0/1+, 2% 1/0+). The large difference between 1987 and recent films may be, at least in part, a reading artefact associated with film appearance. Small opacities of International Labour Organisation (ILO) category 1/0+ were not associated with exposure. An association of borderline significance overall between 0/1+ opacities and exposure to respirable fibres was found for some exposure periods only, the time related pattern being biologically implausible. Pleural changes were related to age and exposure to asbestos, and findings were consistent with an effect of time since first exposure to RCFs. Among men, forced expired volume in 1 second (FEV1) and forced vital capacity (FVC) were inversely related to exposure to fibres, in current smokers only. FEV1/ FVC ratio and transfer factor (TLCO) were not related to exposures. The estimated restrictive effect was on average mild. Prevalence of respiratory symptoms was low. Chronic bronchitis and its associated symptoms (cough, phlegm) showed some association with recent exposure to respirable fibres. This could be due to an irritant effect of RCFs.
OCCUPATIONAL EXPOSURE LIMITS FOR CHEMICALS
Authors: Topping M
Published: July 2002

▸ Occupational exposure limits (OELs) are tools to help employers protect the health of those who may be exposed to chemicals in their workplace. Under the United Kingdom Control of Substances Hazardous to Health (COSHH) Regulations they define adequate control by inhalation.

▸ OELs are set by the Health and Safety Commission (HSC) on advice from its Advisory Committee on Toxic Substances (ACTS) and after public consultation. Thus they are consensus limits which have the support of both sides of industry.

▸ COSHH uses two types of occupational exposure limit—the occupational exposure standard (OES) and the maximum exposure limit (MEL).

▸ OESs are set for substances for which it is possible to identify a concentration at which there is no significant risk to health. Employers are required to meet the limit, there is no requirement to go below it, and it can be exceeded provided steps are taken to meet it as soon as reasonably practicable.

▸ MELs are set for substances which have serious health implications and for which an OES cannot be set. Most of the substances with MELs are either carcinogens or causes of occupational asthma. Employers must not exceed an MEL and must reduce exposure as far below it as is reasonably practicable.

▸ MELs are set at concentrations achievable by good occupational hygiene practice such that risks to workers are judged to be reduced to a tolerable level. The HSC consider that this approach is preferable to the use of mathematical models to generate risk estimates, which inevitably gives a spurious appearance of accuracy.

▸ The MEL/OES system is poorly understand by many employers who use chemicals, is not comprehensive as some substances meet neither the OES nor MEL criteria, and does not mesh well with indicative occupational exposure limit values which will increasingly be set under the European Union Chemical Agents Directive.

▸ COSHH essentials: easy steps to control chemicalsprovides the practical help that firms need to control chemicals. It takes users straight from hazard and exposure considerations to benchmark standards of good practice.

▸ The problems with the current system have prompted ACTS to set up a subgroup to review the OEL framework.
Nasal patency is related to dust exposure in woodworkers
Authors: Schlünssen V , Schaumburg I , Andersen N T , Sigsgaard T , Pedersen O F
Published: July 2002

Objectives: A cross sectional study of 54 furniture factories and three control factories was conducted to investigate the relation between subjective and objective nasal obstruction and exposure to wood dust.

Methods: Acoustic rhinometry was performed on 161 woodworkers and 19 controls. For each person, four measuring rounds were performed: before work, after 4 hours of work, and after 7 hours of work before and after decongestion. Before the first and third measuring round, each person rated the current feeling of nasal obstruction in the left and right nostril separately, using a visual analogue scale. Personal passive dust measurements were performed on 140 woodworkers.

Results: The mean (SD) of equivalent inhalable dust was relatively low, 1.17 (0.62) mg/m3, range 0.17–3.44 mg/m3. The exposure was divided into four levels: controls, low exposure, medium exposure, and high exposure. For the two highest concentrations of exposure, a significant increase in congestion—decreased nasal cavity volume and cross sectional areas—was found after 4 and 7 hours of work, compared with before work. Multivariate linear regression analysis showed positive correlations between concentration of dust and change in mucosal swelling. A significant increase in self rated nasal obstruction was found after work compared with before work for the two highest exposure groups. No correlation between objective nasal variables and self rated nasal obstruction was found.

Conclusion: Exposure to wood dust was related in a dose dependent manner to acute nasal obstruction measured by acoustic rhinometry and self reported obstruction, but no correlation was found between measured and self reported obstruction.
Ambient neighbourhood noise and children's mental health
Authors: Lercher P , Evans G W , Meis M , Kofler W W
Published: July 2002

Objectives:To investigate the relation between typical ambient noise levels (highway, rail, road) and multiple mental health indices of school children considering psychosocial and biological risk factors as potential moderators.

Methods:With a two stage design strategy (representative sample and extreme sample) two cross sectional samples (n=1280; n=123) of primary school children (age 8–11) were studied. Individual exposure to noise at home was linked with two indices of mental health (self reporting by the child on a standard scale and rating by the teacher of classroom adjustment on a standard scale). Noise exposure was modelled firstly according to Austrian guidelines with the aid of a geographical information system and then calibrated and corrected against measurements from 31 locations. Information on potential confounders and risk factors was collected by mothers and controlled in regression modelling through a hierarchical forward stepping procedure. Interaction terms were also analysed to examine subgroups of children at risk—for example, low birth weight and preterm birth.

Results:Noise exposure was significantly associated in both samples with classroom adjustment ratings. Child self reported mental health was significantly linked to ambient noise only in children with a history of early biological risk (low birth weight and preterm birth).

Conclusions:Exposure to ambient noise was associated with small decrements in children's mental health and poorer classroom behaviour. The correlation between mental health and ambient noise is larger in children with early biological risk.
Understanding the pathology of schizophrenia: recent advances from the study of the molecular architecture of postmortem CNS tissue
Authors: Dean B
Published: July 2002

The use of central nervous system (CNS) tissue obtained postmortem has long underpinned efforts to understand the neurobiology of schizophrenia, but the ability to use such tissue in conjunction with a wide variety of methodologies has seen a renaissance of interest in this area of research. Recent findings have shown changes in markers in a number of neurotransmitter systems in the brains of subjects with schizophrenia which include the dopaminergic, serotonergic, cholinergic, glutamatergic, and GABAergic systems of the CNS. Many of these changes also appear to be regionally specific, and abnormalities in non-neurotransmitter specific pathways have been found in schizophrenia. Changes in the neurotransmitter release pathways in schizophrenia may be important in the pathology of the illness, and recent findings suggest that abnormalities in the Wnt pathway, which controls transcription selectivity in cells, may be involved. Studies using CNS material obtained postmortem clearly show that the pathology of schizophrenia is complex while the polygenetic nature of the illness may be adding to this complexity.
Bacille Calmette-Guérin lymphadenitis
Authors: Goraya J S , Virdi V S
Published: July 2002

Bacille Calmette-Guérin (BCG) lymphadenitis is the most common complication of BCG vaccination. Two forms of BCG lymphadenitis can be recognised in its natural course—simple or non-suppurative lymphadenitis, which usually regresses spontaneously over a period of few weeks, and suppurative BCG lymphadenitis distinguished by the development of fluctuations in the swelling, with erythema and oedema of overlying skin. Healing in suppurative glands occurs through spontaneous perforation and sinus formation, followed by closure of the sinus by cicatrisation. Non-suppurative BCG lymphadenitis is best managed with expectant follow ups only, because medical treatment with erythromycin or antituberculous drugs do not hasten the regression or prevent development of suppuration. Suppurative BCG lymphadenitis may be treated by needle aspiration to hasten resolution and prevent spontaneous perforation and sinus formation. Surgical excision is rarely needed and is meant for cases of failed needle aspiration or for draining BCG nodes.
Red/far-red light mediated stem elongation and anthocyanin accumulation in Stellaria longipes: differential response of alpine and prairie ecotypes
Authors: Alokam Suneetha , Chinnappa C C , Reid David M
Published: July 2002

We compared the stem elongation response and anthocyanin accumulation between alpine and prairie plants of Stellaria longipes Goldie under different red/far-red light ratios (R/FR) of 0.7 and 1.9 while all other environmental conditions were uniform. Both ecotypes responded to light quality. The prairie ecotype, considered to be the shade avoider, showed greater stem elongation in response to low R/FR (0.7) than under high R/FR (1.9) as compared with the alpine ecotype. The levels of anthocyanin in prairie plants, as compared with alpine plants, were significantly higher under high R/FR. Under low R/FR, both showed almost the same levels of anthocyanin. Also, the two ecotypes upon etiolation showed differences in the sites of anthocyanin accumulation under different R/FR. The results of the present study show that the extent of the stem elongation response and anthocyanin accumulation in the two ecotypes of S. longipes is likely a result of their origins in two contrasting habitats.Key words: Stellaria, plasticity, anthocyanin, R/FR, stem elongation.
Damages to residential buildings related to pyritic rockfills: field results of an investigation on the south shore of Montreal, Quebec, Canada
Authors: Ballivy Gérard , Rivard Patrice , Pépin Caroline , Tanguay Marc G , Dion Alexandre
Published: July 2002

Numerous cases of garage and basement concrete slab distress at various levels of heaving and deterioration were noticed early after construction in the Montreal south-shore area (Canada). The use of clayey sedimentary rock containing pyrite as aggregates for granular subbase is responsible for most of the observed distress. The heaving of the slabs is related to the oxidation process of the pyrite, followed by sulphate crystallization causing the swelling of the compacted granular subbase. A first inspection survey was carried out in the summer of 1999 in an attempt to assess the extent and magnitude of the damage caused by pyritic rockfills. More than 200 houses showing distress associated with pyrite were investigated in three localities. Damage of the garage floor slab seems to occur earlier after construction and to be more severe likely due to the subbase thickness and to the lower quality of the rockfill. Five houses at various stages of reaction process were monitored. The results suggest that the rockfill swelling is quite fast and continuous. The heaving rate of some garage slabs might be as high as 1.2 mm/month.Key words: pyrite, shales, swelling rockfill, oxidation, sulphate attack, damage.
Protamine-like proteins: evidence for a novel chromatin structure
Authors: Lewis John D , Ausió Juan
Published: July 2002

Protamine-like (PL) proteins are DNA-condensing proteins that replace somatic-type histones during spermatogenesis. Their composition suggests a function intermediate to that of histones and protamines. Although these proteins have been well characterized at the chemical level in a large number of species, particularly in marine invertebrates, little is known about the specific structures arising from their interaction with DNA. Speculation concerning chromatin structure is complicated by the high degree of heterogeneity in both the number and size of these proteins, which can vary considerably even between closely related species. After careful examination and comparison of the protein sequences available to date for the PL proteins, we propose a model for a novel chromatin structure in the sperm of these organisms that is mediated by somatic-type histones, which are frequently found associated with these proteins. This structure supports the concept that the PL proteins may represent various evolutionary steps between a sperm-specific histone H1 precursor and true protamines. Potential post-translational modifications and the control of PL protein expression and deposition are also discussed.Key words: protamine-like proteins, histones, chromatin structure, sperm, evolution.
Towards a more rational approach to chemical compatibility testing of clay
Authors: Kodikara J K , Rahman F , Barbour S L
Published: July 2002

Chemical compatibility tests using hydraulic conductivity testing with chemical permeants are normally undertaken to assess the integrity of compacted clayey liners used for waste containment. This paper highlights the fact that current routine methods of flexible wall and rigid wall testing techniques fail to represent the zero lateral strain boundary condition that is required to realistically represent the field situation. The test results indicate that flexible wall permeameters underestimate the likely increases in hydraulic conductivity due to chemicals, while the rigid wall permeameters can severely overestimate these effects. A new test technique, which incorporates the zero lateral strain condition in a simple manner, is presented. This technique involves the use of a rigid wall concept in a flexible wall permeameter. A split rigid mould is used to encase the soil specimen that is glued to the internal surfaces of the mould, to apply the zero lateral strain boundary condition. The new technique is shown to be suitable for both chemical compatibility and desiccation testing. The tests were undertaken with varying concentrations of saline water, methanol, and landfill leachate. The test results indicate that the new technique produces results that fall between the results obtained from flexible wall and rigid wall permeameters. It is argued that the new test technique provides a more rational approach for chemical compatibility testing than the current rigid wall and flexible wall techniques.Key words: soil, hydraulic conductivity, chemical compatibility, landfill, permeameter, boundary condition.
Hydrogénation électrocatalytique sur des catalyseurs composites de nickel et hydroxyde d'aluminium en cellule dynamique
Authors: Dubé Patrick , Brossard Louis , Ménard Hugues
Published: July 2002

The electrocatalytic hydrogenation (ECH) of cyclohexanone into cyclohexanol has been studied in aqueous media with electrocatalysts on composites powders. These powders are formed of nanoaggregates of nickel obtained through a physical deposition under vacuum on particles of Al(OH)3, AlO(OH), and γ-Al2O3. The ECH reaction was done in a dynamic cell. Its yield is closely dependent on the nature of the non-metallic particles whose nature greatly influences the adsorptiondesorption of the organic compounds involved in the reaction.Key words: electrocatalysis, aluminum oxide, aluminum hydroxide, hydrogenation, dynamic cell.[Traduit par la Rédaction]
Gap junctions and tumour progression
Authors: Naus Christian CG
Published: July 2002

Gap junctional intercellular communication has been implicated in growth control and differentiation. The mechanisms by which connexins, the gap junction proteins, act as tumor suppressors are unclear. In this review, several different mechanisms are considered. Since transformation results in a loss of the differentiated state, one mechanism by which gap junctions may control tumour progression is to promote or enhance differentiation. Processes of differentiation and growth control are mediated at the genetic level. Thus, an alternative or complimentary mechanism of tumour suppression could involve the regulation of gene expression by connexins and gap junctional coupling. Finally, gap junction channels form a conduit between cells for the exchange of ions, second messengers, and small metabolites. It is clear that the sharing of these molecules can be rather selective and may be involved in growth control processes. In this review, examples will be discussed that provide evidence for each of these mechanisms. Taken together, these findings point to a variety of mechanims by which connexins and the gap junction channels that they form may control tumour progression.Key words: gap junctions, connexin, cancer.
THE (ORBIFOLD) EULER CHARACTERISTIC OF THE MODULI SPACE OF CURVES AND THE CONTINUUM LIMIT OF PENNER'S CONNECTED GENERATING FUNCTION
Authors: CHAIR NOUREDDINE
Published: July 2002

The generating function that gives rise to the orbifold Euler characteristic of the moduli space of punctured compact Rieman surfaces [Formula: see text], g ≥ 0 is derived explicitly. In the derivation, we show that we do not need to use the three-term recursion relation for the orthogonal polynomials. Also the continuum limit of Penner's connected generating function is considered and is shown to be formally equivalent to the free energy obtained recently by Distler and Vafa which exhibits the logarithmic divergences found for genus zero and one in D = 1 matrix models. Finally, it is shown that the free energy and its s-derivatives are nothing but the continuum limit of a certain generating function introduced by Harer and Zagier in obtaining the true Euler characteristic with any number of punctures,[Formula: see text], s ≥ 0.
HALF-DIFFERENTIALS AND FERMION PROPAGATORS
Authors: DICK RAINER
Published: July 2002

From a geometric point of view, massless spinors in 3+1 dimensions are composed of primary fields of weights [Formula: see text] and [Formula: see text], where the weights are defined with respect to diffeomorphisms of a sphere in momentum space. The Weyl equation thus appears as a consequence of the transformation behavior of local sections of half-canonical bundles under a change of charts. As a consequence, it is possible to impose covariant constraints on spinors of negative (positive) helicity in terms of (anti-)holomorphy conditions. Furthermore, the identification with half-differentials is employed to determine possible extensions of fermion propagators compatible with Lorentz covariance.
BIHARMONIC SUBMANIFOLDS OF ${\mathbb S}^3$
Authors: CADDEO R. , MONTALDO S. , ONICIUC C.
Published: July 2002

We explicitly classify the nonharmonic biharmonic submanifolds of the unit three-dimensional sphere [Formula: see text].
A CRITERION FOR GETTING A BIG COMPONENT OF THE MODULI OF VECTOR BUNDLES BY CHANGING A POLARIZATION
Authors: YAMADA KIMIKO
Published: July 2002

Let MH(c1, c2) be a coarse moduli scheme parameterizing all rank-two H-μ-stable vector bundles with Chern classes (c1, c2) on a smooth projective surface X over an algebraically closed field. For fixed two ample line bundles H and H′, it is known that if c2 is greater than some constant p(X, H, H′) depending on H and H′ then MH(c1, c2) and MH′(c1, c2) are birationally equivalent. In this paper we show that this constant p(X, H, H′) generally does depends on the choice of H and H′. More precisely, we give some example of surface (and c1) on which, for any number K, there exists an integer c2 with c2≥K such that sup H: ample dim MH(c1, c2) = + ∞. This result is available also for normal surfaces.
VARIETIES WITH DEGENERATE GAUSS MAPPINGS IN COMPLEX HYPERBOLIC SPACE FORMS
Authors: HWANG JUN-MUK
Published: July 2002

In analogy with the Gauss mapping for a subvariety in the complex projective space, the Gauss mapping for a subvariety in a complex hyperbolic space form can be defined as a map from the smooth locus of the subvariety to the quotient of a suitable domain in the Grassmannian. For complex hyperbolic space forms of finite volume, it is proved that the Gauss mapping is degenerate if and only if the subvariety is totally geodesic.
NET-CONSOLE: WEB-BASED DEVELOPMENT ENVIRONMENT FOR PARALLEL PROGRAMS
Authors: EVRIPIDOU PARASKEVAS , SAMARAS GEORGE , SPYROU CONSTANTINOS , PAPAGAPIOU ANDREAS
Published: July 2002

Net-Console is an integrated program development environment that can be used as a front-end for High Performance Computing (HPC) sites. It consist of an MPI-aware editor, an execution console, a debugger, monitoring tools and an account and file manager. Using Net-console the user is able to edit, execute, debug and evaluate the performance of parallel programs from anywhere in the Internet. The user interface is done through a normal Java-enabled browser. Net-console can also support processing through wireless and lightweight devices with the use of mobile agent technologies. The tools included in Net-console and their functionality, the languages used and the overall structure of the project are presented in this paper.
FRIEDMANN EQUATION AND CARDY FORMULA CORRESPONDENCE IN BRANE UNIVERSES
Authors: WANG BIN , ABDALLA ELCIO , SU RU-KENG
Published: July 2002

We study the brane with arbitrary tension σ on the edge of various black holes with AdS asymptotics. We investigate Friedmann equations governing the motion of the brane universes and match the Friedmann equation to Cardy entropy formula.
THE b→sgg DECAY IN THE TWO AND THREE HIGGS DOUBLET MODELS WITH CP VIOLATING EFFECTS
Authors: GOKSU A. , ILTAN E. O. , SOLMAZ L.
Published: July 2002

We study the decay width and CP asymmetry of the inclusive process b→sgg (g denotes gluon) in the three and two Higgs doublet models with complex Yukawa couplings. We analyze the dependencies of the differential decay width and CP asymmetry to the s-quark energy Es and CP violating parameter θ. We observe that there exist a considerable enhancement in the decay width and CP asymmetry is at the order of 10-2. Further, it is possible to predict the sign of [Formula: see text] using the CP asymmetry.
A NONLOCAL DISCRETIZATION OF FIELDS
Authors: CAMPOS RAFAEL G. , TUTUTI EDUARDO S. , PIMENTEL L. O.
Published: July 2002

A nonlocal method to obtain discrete classical fields is presented. This technique relies on well-behaved matrix representations of the derivatives constructed on a nonequispaced lattice. The drawbacks of lattice theory like the fermion doubling or the breaking of chiral symmetry for the massless case are absent in this method.
THE WEAK INTERACTION: ITS HISTORY AND IMPACT ON PHYSICS
Authors: LEE T. D.
Published: July 2002

It is a pleasure and an honor for me to give this lecture in honor of Oscar Klein who made major contributions to field theory, quantum electrodynamics and particle physics, including weak interactions. He was the first one to observe that the μ decay and the β decay could be described by the same interaction with the same coupling constant; this led to the discovery of the Universal Fermi Interaction.

Perhaps I should begin my discussion of the history of weak interactions by separating it into three periods:

(1) Classical Period, 1898–1949.

(2) Transition Period, 1949–1956.

(3) Modern Period, 1956–.
GAUGE MODELS IN MODIFIED TRIPLECTIC QUANTIZATION
Authors: GEYER B. , LAVROV P. M. , YU. MOSHIN P.
Published: July 2002

The modified triplectic quantization is applied to several well-known gauge models: the Freedman–Townsend model of non-Abelian antisymmetric tensor fields, W2 gravity, and 2D gravity with dynamical torsion. For these models we obtain explicit solutions of those generating equations that determine the quantum action and the gauge-fixing functional. Using these solutions, we construct the vacuum functional, determine the Sp(2)-invariant effective actions and obtain the corresponding transformations of extended BRST symmetry.
THE PIERRE AUGER PROJECT: AN OBSERVATORY FOR THE HIGHEST ENERGY COSMIC RAYS
Authors: BEATTY JAMES J.
Published: July 2002

Cosmic rays with energies above 1020 eV have been observed. The existence of these events presents us with a puzzle. The Greisen-Zatsepin-Kuzmin cutoff in the spectrum expected due to interactions with the cosmic background radiation is not observed. This constrains the origin of conventional particles responsible for these events to cosmologically-nearby distances (≪ 100 Mpc). Cosmic ray protons at these energies are deflected little by intergalactic magnetic fiels, so an association with likely sources on the sky is expected but has not been convincingly observed. Our understanding of the origin of these events is hampered by poor statistics and sky coverage, since the rate of cosmic rays above 1020 eV is about one particle per km2 per century. The Pierre Auger project has been formed to address this problem. Two 3000 km2 observatory sites, one in each hemisphere, are planned to provide full sky coverage. Each site will include a hybrid detector consisting of a water Cerenkov detector array on the surface and air fluorescence 'eyes'. The southern observatory, located near the town of Malargue in Mendoza, Argentina, is now under construction.
CONSTRAINTS ON NEUTRAL BOSONS OF THESp(6)L⊗U(1)YMODEL
Authors: BAGNEID ALI A.
Published: July 2002

Lower limits are calculated on the mass of an additional neutral gauge boson, Z′, suggested by the Sp (6)L⊗ U (1)Ymodel, using direct search limits at hadron collider. We found that MZ′≥ 655 GeV . The production cross-section times branching ratio of Z′ decaying into dileptons in hadronic collisions, is found to be generation dependent and can be used to distinguish the model.
DUALITY PICTURE BETWEEN ANTIFERROMAGNETISM AND d-WAVE SUPERCONDUCTIVITY IN t-J MODEL AT TWO DIMENSIONS
Authors: NG TAI KAI
Published: July 2002

We show in this paper an interesting relation between elementary and topological excitations in the antiferromagnetic and d-wave superconducting phases of the t–J model at two dimensions. The topological spin and charge excitations in one phase have the same dynamics as elementary excitations in the other phase, except the appearance of energy gaps. Moreover, the transition from one phase to another can be described as a quantum disordering transition associated with the topological excitations. Based on the above picture, a plausible phase diagram of t–J model is constructed.
COIL-GLOBULE TRANSITION OF A SEMI-FLEXIBLE CHAIN
Authors: TERAMOTO T. , YONEZAWA F.
Published: July 2002

We carry out Monte Carlo simulations of a semi-flexible chain model, in which we add a bending and torsional restrictions to the bead-spring model. From our simulations for various temperatures, we show that the coil and globule state coexist over a finite temperature region for stiff chains. On the basis of our analysis, we assert that the ratio of the persistence length to the chain length is a key factor in determining whether or not the coexistence of the two states appears for short chains. This assertion of ours differs from the proposition offered by the so-called modern theory of coil-globule transitions which argues that the persistence length itself is a deciding factor.
CHARGE AND SPIN MODULATION IN THE PRESENCE OF A DIMERIZED CRYSTAL FIELD
Authors: CAPRARA S.
Published: July 2002

I study the evolution of the antiferromagnetic ground state of the half-filled Hubbard model in the presence of a charge modulation induced by the dimerization of the crystal field, making use of the slave-boson approach. I also discuss how the model can be extended to describe the neutral-to-ionic transition which occurs in some organic mixed-stack donor-acceptor crystals.
SUPERSTRIPES BY ANOMALOUS X-RAY DIFFRACTION AND ANGLE RESOLVED PHOTOEMISSION IN BI2212
Authors: SAINI N. L. , BIANCONI A.
Published: July 2002

We show an evidence for the superconducting stripes (superstripes) in the Bi2212 system by joint x-ray diffraction and angle resolved photoemission. The kink observed at k y =0.4π in the energy distribution curves is shown to be related to a modulation of the Cu displacement out of the oxygen plane with a wavevector Q ~(0.4π, 0.4π) that modulates the next-nearest neighbor hopping integral t ′. The resulting Fermi surface reveals broken segments around the M points due to the modulation of the t ′, associated with modulation of the electron-lattice coupling λ(ε) that depends on the micro strain ε of the CuO 2 plane. The present findings further enlightens the fact that the micro-strain, controlling the electron-lattice coupling λ(ε) is a critical parameter for the superstripes.
STRIPE STABILITY IN DOPED ANTIFERROMAGNETS
Authors: WRÓBEL PIOTR , EDER ROBERT
Published: July 2002

In the framework of the t-Jz we discuss localized spin polarons for various original hole arrangements in different spin backgrounds. According to the so-called string picture we assume that local destruction in the magnetic structure caused by hole motion tends to localize holes and acts on them as a kind of well potential. We concentrate on the case of the hole concentration 1/8 for which stripes are experimentally observed. We explicitly take into account interaction between holes and consider several possible configurations, that represent: holes homogeneously distributed in the antiferromagnetic background, hole pairs (which correspond to spin bipolarons) homogeneously distributed in the antiferromagnetic background, hole pairs which form the stripe structure in the perfect antiferromagnetic background, and eventually holes in stripes which separate antiferromagnetic domains with alternating direction of the staggered magnetization. Spin polarons are constructed by means of some computer algebra. It turns out that lowest eigenenergy has a state that represents a single hole polaron at the anti-phase domain wall (ADW). On the other hand, the stripe phase is exposed to keen competition from holes binding in the antiferromagnetic background and the energy margin by which stripes win is small.