bluuebunny/crossref_metadata_2025 huggingface dataset:
The Hemophilia Utilization Group Study (HUGS): determinants of costs of care in persons with haemophilia A
Authors: Globe D. R. , Cunningham W. E. , Andersen R. , Dietrich S. L. , Curtis R. G. , Parish K. L. , Miller R. T. , Sanders N. L. , Kominski G.
Published: December 2004

Summary.  Objective: The main objective of this study was to examine factors associated with utilization and costs for persons with haemophilia. Study design: Utilization data and patient characteristics were collected through medical record review of 336 patients receiving treatment for at least 90% of their haemophilia care at one of five comprehensive haemophilia treatment centres in California. Principal findings: The range of factor VIII deficiency in our sample was similar to the distribution among haemophilic patients in the Western United States; 215 (64%) had severe FVIII deficiency. The mean age in our sample was 21.4 (SD = 16.2) years old and 114 (34%) were HIV‐positive. In the multivariate model predicting the total cost of health care during 1995 (adjusted R2 = 0.40), total annual costs were significantly (P < 0.05) associated with being HIV‐seropositive, infusing FVIII concentrate through a port vs. i.v. infusion, the number of comorbidities, moderate arthropathy (compared with no arthropathy), mild arthropathy, history of inhibitor to FVIII, and current prophylactic FVIII concentrate infusion. Conclusion: As expected, total health‐care costs were correlated with comorbid medical conditions, such as HIV and sequelae of haemophilia such as arthropathy. Health policy should consider risk adjustment for the presence of complications such as arthropathy and HIV infection in the financing of haemophilia treatment to promote more equitable delivery of these services.
The role of the platelet function analyser (PFA‐100TM) in the characterization of patients with von Willebrand's disease and its relationships with von Willebrand factor and the ABO blood group
Authors: Nitu‐Whalley I. C. , Lee C. A. , Brown S. A. , Riddell A. , Hermans C.
Published: December 2004

Determination of the closure time (CT) with the platelet function analyser (PFA‐100TM) is a useful screening test for von Willebrand's disease (VWD) but its role in the characterization of VWD is not well established. We studied the relationship between the prolongation of the CT with adenosine diphosphate (ADP) (CT‐ADP) and epinephrine (CT‐EPI) cartridges and the von Willebrand factor (VWF) in 53 patients with VWD. We found that a relatively small percentage of the prolongation of the CT‐ADR and CT‐ADP (16 and 29%, respectively) was determined by a reduction in VWF levels. The CT‐ADP was significantly more prolonged in the presence of qualitative defects in VWF but could not discriminate between the VWD subtypes. The ABO blood group had no effect on the prolongation of the CT or the bleeding time. In conclusion, the PFA‐100TM appears of little use in the characterization of severity and subtype of VWD.
A country‐by‐country comparison of FVIII concentrate consumption and economic capacity for the global haemophilia community
Authors: Stonebraker J. S. , Amand R. E. , Nagle A. J.
Published: December 2004

Summary.  The article presents a method to estimate the level of factor VIII (FVIII) concentrate consumption and economic capacity for each of the 110 countries considered in the study. A number of health‐economic indicators were examined and purchasing power parity (PPP) gross national income (GNI) per capita had the strongest correlation with amount of FVIII concentrates sold in a country. Available data on FVIII concentrate consumption and health‐economic indicators were used to calculate index values for FVIII use and economic capacity so each country can assess and compare its level of FVIII concentrate consumption with the economic resources of other countries in the global haemophilia A community. This article is of importance to policy makers, care givers and patient organizations in planning health‐care resources for the treatment of haemophilia.
The WFH Haemophilia Centre Twinning Programme: 10 years of growth, 1993–2003
Authors: Giangrande P. L. F. , Mariani G. , Black C.
Published: December 2004

Summary. The World Federation of Haemophilia (WFH) Twinning Programme celebrates its tenth anniversary this year. Twinning is one of several international WFH programmes designed to improve haemophilia care at a global level. There are two types of twinning, and the haemophilia treatment centre twinning programme should be distinguished from the WFH haemophilia organization twinning involving national member organizations. The WFH Haemophilia Treatment Centre Twinning Programme helps emerging haemophilia treatment centres develop partnerships with well‐established and experienced centres. Twinning can improve diagnosis and clinical care through coaching, training and transfer of expertise, ultimately leading to improved quality of life for patients. Twinning can also enhance the profile and recognition of treatment centres in emerging countries, which can be valuable in raising awareness among politicians and the media. Examples of activities include consultation on the management of specific cases, clinical and laboratory training, donation of equipment and publications as well as research projects. The centre twinning programme also benefits centres in developed countries by giving them the opportunity to gain exposure to clinical problems no longer encountered in their own countries, as well as experience of new cultures. Currently, a total of 23 treatment centres around the world are linked through the twinning programme and applications for new partnerships are welcome. Twinning links are not permanent, but are reviewed on an annual basis and typically remain in place for periods of 3–5 years. Limited financial support from WFH is available to twinned centres in the form of money for an initial assessment visit, as well as regular annual grants to established partners and the possibility of applying for additional funding to support specific projects. In addition, continuing support and advice are available from the WFH regional programme officers.
Treatment on demand –in vivodose finding studies
Authors: Escobar M. A.
Published: December 2004

Summary.Since the discovery of replacement therapy the goal of treatment for haemophilia patients has always been the prevention of haemorrhagic epsiodes. However, the “ideal”’’ plasma level needed to prevent hemathrosis or treat haemorrhages is still unknown. It seems that the doses of treatment have been arrived at by trial and error based in the pharmacokinetics of the factors and the characteristics of the replacement product. This review provides some guidelines for the treatment of haemophilia, however the doses are not based in randomized trials.
The pharmacokinetics of clotting factor therapy
Authors: Berntorp E. , Björkman S.
Published: December 2004

Summary.Clotting factor preparations are expensive and not readily available in all parts of the world. We are still facing shortages due to limited production. Thus, it is obvious that clotting factor therapy should be optimised as far as possible. The judicious use of pharmacokinetic principles should be one of the fundaments of dosing. There are several pitfalls in studies of clotting factor pharmacokinetics, such as discrepancies between assays, inadequate blood sampling protocols, problems to define the administered dose, uncertainty in the estimation of plasma volume forin vivorecovery calculation, and post‐infusion activation of the clotting factor. Thus, while the pharmacokinetics of factor VIII is well characterised there are some discrepancies in the literature on factor IX. Recombinant factor VIIa is useful to treat haemorrhages in haemophilia complicated by inhibitors. The pharmacokinetics of VIIa has been investigated, however, the relationship between plasma level of VIIa and effect needs further exploration. Important applications of clotting factor pharmacokinetics include optimising the treatment and improving its cost‐effectiveness during long‐term prophylaxis as well as during bleeding episodes and surgery.
Factor replacement therapy in haemophilia – are there models for developing countries?
Authors: Srivastava A.
Published: December 2004

Summary.  Successful models for factor replacement in severe haemophilia involves prophylactic or on‐demand administration of large quantities (1500–9000 IU kg−1 year−1) of very high purity factor concentrates starting early in life. The prohibitive cost of these protocols make them completely impractical in developing countries where the quantity of factor used for replacement therapy is much lower and varies considerably (25–500 IU kg−1 year−1). At this level of treatment, as some joint damage is inevitable, the aim of therapy shifts to preventing disability and preserving reasonable joint function rather than perfect architecture. There are no carefully recorded data on long‐term outcome of musculo‐skeletal function on these doses. Appropriate studies are needed to document such data. With regard to products for factor replacement, economic compulsions lead to the use a variety of factor concentrates and blood‐bank products for replacement therapy. Most patients in the developing world do not have access to adequate replacement therapy. Among the rest, some get limited quantities of plasma‐derived concentrates while others use cryoprecipitate, fresh frozen plasma or even whole blood. Since the superiority of virus‐inactivated purified factor concentrates in achieving the aims of replacement therapy is well established, the aim should be to provide this for all people with haemophilia. This can be achieved by production of such concentrates locally or by importing them. Different models are possible depending on the circumstances in each country.
Economic modelling of different treatment strategies for haemophilia A with high‐responding inhibitors
Authors: Knight C. , Paisley S. , Wight J. , Jones M. L.
Published: December 2004

Summary.  This paper reports a systematic review of the cost‐effectiveness of treatment options in patients with haemophilia A with inhibitors. As very little relevant published evidence was identified, an economic modelling exercise was undertaken to calculate the cost‐effectiveness of different strategies in the treatment of high‐responding haemophilia A patients with inhibitors. A decision analysis approach was used to model the expected lifetime clinical outcomes and costs of the more common regimens currently used in UK in treating severe haemophiliacs with inhibitors.

The model attempts to reflect the outcomes of clinical events, costs and life expectancy for each different treatment regimen for haemophilic boys with inhibitors who are high responders (defined as inhibitor level ≥10 BU) throughout their life. The basic model structure is centred on a Markov decision process, which was used to simulate, at quarter‐yearly intervals, the movement through discrete health states and their complications.

The model allows a comparison of cost‐effectiveness between three immune tolerance induction (ITI) regimens (Bonn, Mälmo and Low‐Dose protocols) and against a relevant ‘on‐demand’ (OD) regimen. It also shows the cost‐effectiveness of different OD regimens using different bypassing agents.

The results of the economic modelling indicate that treating haemophilia A patients who have high‐responding inhibitors OD with recombinant activated factor VII is cost‐effective compared to treatment with activated prothrombin complex concentrates. However, when OD treatment regimens are compared with the three ITI protocols, the Malmö ITI protocol is the preferred treatment strategy, generating more quality adjusted life‐years (QALYs) and less cost than either an OD regimen or the Bonn or Low‐Dose ITI protocols.
Successful use of recombinant factor VIIa for severe surgical liver bleeding in a 5 month‐old baby
Authors: Barro C. , Wrobleski I. , Piolat C. , Cartal M. , Dyon J.‐F. , Jacquier C. , Andrini P. , Polack B. , Pernod G.
Published: December 2004

Summary.   A 5 month‐old baby developed non‐ceasing intra‐peritoneal bleeding after extensive surgical biopsy for an hepatoblastoma. A single recombinant activated factor VII injection following enlarged hepatectomy helped to resolve quickly this life‐threatening haemorrhagic syndrome.
When to start and when to stop primary prophylaxis in patients with severe haemophilia
Authors: Astermark J.
Published: December 2004

Summary.  Primary prophylactic treatment of patients with severe haemophilia has been shown to reduce the number of bleeding episodes and to minimize the development of arthropathy. However, since the use of clotting factor concentrates is associated with considerable cost and not all patients with severe haemophilia have a severe bleeding phenotype, there is still no consensus about when to start prophylaxis, which dosing regimen to use, and if or when the treatment should be stopped when the patient becomes elderly. Some care providers are also concerned about the use of central venous lines in very young children. Even though most available data indicate that prophylaxis should be started during the first years of life, it may be possible to adjust the dose and dose interval depending on the bleeding pattern. The use of an individualized prophylactic regimen may also improve cost‐effectiveness and make the use of this treatment modality more feasible. Studies to further address this issue are warranted.
Prospective controlled studies on prophylaxis: an Italian approach
Authors: Gringeri A.
Published: December 2004

Summary.  The benefits of prophylactic infusion of clotting factor in haemophilia A and B in delaying the onset of arthropathy are supported by retrospective data, but the possibility of selection bias and confounding factors cannot be ruled out by such studies. Many issues that have only been studied retrospectively require definitive data, including the optimal dose and infusion intervals, as well as when to start prophylaxis and when to stop it. Issues of cost‐effectiveness of prophylaxis, quality of life and treatment satisfaction of patients on prophylaxis and their families also require prospective data. To advance the evidence‐based approach in haemophilia treatment, ESPRIT (Evaluation Study on Prophylaxis: a Randomized Italian Trial), currently underway, is a prospective randomized 10‐year study that will compare the efficacy and safety of prophylaxis and on‐demand regimens in preventing joint deterioration and in reducing the number of bleeds in patients with severe haemophilia A.
Central venous lines in haemophilia
Authors: Ljung R.
Published: December 2004

Summary. Infections and technical problems are the most frequent complications when using implantable central venous access devices in patients with haemophilia. There are two major experiences reported concerning infections in noninhibitor patients: one is approximately 0.2 infections per 1000 days and the other approximately 1.0 (0.7–1.6) per 1000 days. Infections are more frequent in inhibitor patients and approximately one infection per 6–12 months of use can be expected. The figures are low for clinically apparent thrombosis in the larger series on record, but routine venograms were not carried out in most of these series. In studies where this has been done, a high frequency of abnormalities on venograms has been seen in some but not in others. The final decision to use a central line has to take into account the medical goal, the patient's bleeding tendency, the social situation and the expected risk of complications at the particular haemophilia centre. Some of the complications may be reduced by adequate aseptic measures both during implantation and in subsequent use, and by clear basic routines for surveillance of the systems and repeated education of the users.
Transcription of purine transporter genes is activated during the isotropic growth phase of Aspergillus nidulans conidia
Authors: Amillis Sotiris , Cecchetto Gianna , Sophianopoulou Vicky , Koukaki Marina , Scazzocchio Claudio , Diallinas George
Published: December 2004

Aspergillus nidulans possesses three well‐characterized purine transporters encoded by the genes uapA, uapC and azgA. Expression of these genes in mycelium is induced by purines and repressed by ammonium or glutamine through the action of the pathway‐specific UaY regulator and the general GATA factor AreA  respectively.  Here,  we  describe  the  regulation of expression of purine transporters during conidiospore germination and the onset of mycelium development. In resting conidiospores, mRNA steady‐state levels of purine transporter genes and purine uptake activities are undetectable or very low. Both mRNA steady‐state levels and purine transport activities increase substantially during the isotropic growth phase of conidial germination. Both processes occur in the absence of purine induction and independently of the nitrogen source present in the medium. The transcriptional activator UaY is dispensable for the germination‐induced expression of the three transporter genes. AreA, on the other hand, is essential for the expression of uapA, but not for that of azgA or uapC, during germination. Transcriptional activation of uapA, uapC and azgA during germination is also independent of the presence of a carbon source in the medium. This work establishes the presence of a novel system triggering purine transporter transcription during germination. Similar results have been found in studies on the expression of other transporters in A. nidulans, suggesting that global expression of transporters might operate as a general system for sensing solute availability.
Using nominal group technique to assess chronic pain, patients' perceived challenges and needs in a community health region
Authors: Dewar Anne , White Marc , Posade Santiago T. , Dillon Wilson
Published: December 2004

Purpose  The purpose of this study was to better understand the experiences of people suffering from chronic pain in order to plan client‐centred educational interventions.

Methods  People in the community with chronic pain were invited via newspapers, newsletters and e‐mail discussion lists to participate in a needs assessment process and to attend an educational session at a local community college. Using the nominal group technique, which is a qualitative method of data gathering, 53 participants reported their perceived challenges and needs in dealing with chronic pain. Participants were randomly assigned to one of 10 groups ranging from three to seven people. Responses were pooled to develop an overall list of their major concerns and needs.

Results  Issues were classified into six priority areas: medical and treatments, problems with daily living, emotional distress, social issues, sleep disturbances and financial issues. Participants indicated they had difficulty finding accessible, effective and acceptable care. Many participants perceived their family physician or other health‐care providers were not adequately meeting their health‐care needs. Specifically, sleep disorders; feeling of depression, irritability, worry and anxiety were perceived as medical and treatment areas requiring improvement. In addition, participants sought greater validation of their lived experience of chronic pain.

Conclusion  Participants perceived that their needs were not being met adequately. There is a need for further study on physician–patient communication and its impact on patient health status and disability.
A note on the relative importance that people attach to different factors when setting priorities in health care
Authors: Dolan Paul , Shaw Rebecca
Published: December 2004

Objective  To explore whether and to what extent people wish to give differential priority when asked to choose between providing health care treatment for different individuals or groups, on the basis of a range of factors, ranging from health gain to the number of dependants a person has.

Design  A sample of people resident in York self‐completed a questionnaire.

Setting  The City of York.

Participants  Twenty‐three members of the general public and 29 undergraduate students.

Main outcome measures  The relative importance of factors that people think should be taken into account when choosing between providing health care treatment for individuals or groups.

Results  The results suggest that health gain and the consequences for health without treatment are two of the most important considerations.

Conclusions  A sample of the general public and undergraduate students wish to take account of a number of personal characteristics when setting priorities in health care.
An approach to determining the workability diagram based on upsetting tests
Authors: VILOTIĆ D. , PLANČK M. , GRBIĆ S. , ALEXANDROV S. , CHIKANOVA N.
Published: December 2004

To determine a workability diagram for bulk metal forming processes, it is proposed to use experiments in which fracture occurs at a free surface. A good example of such experiments is an upsetting test with profiled dies. An advantage of this method is that fracture conditions are formulated in terms of strain components whereas stresses are excluded using an exact theoretical solution. In the present study three axisymmetric upsetting tests, with flat dies and with conical dies, are carried out to determine the strain to fracture. The method proposed is then combined with these experimental data to find an approximation to the workability diagram of a tool steel.
Detection of crack nucleation in sheet metalforming by monitoring infrared radiation
Authors: ANDRIANOPOULOS N. P. , CHAMPIDIS K. T. , ILIOPOULOS A. P.
Published: December 2004

In the present work a method is described for the early detection of large plastic strains localisation and subsequent crack nucleation in sheet metalforming. The method is based on the monitoring of the infrared radiation emitted from the material during stretching. It is concluded that the point of the final crack nucleation can be located in the very early stages of stretching, when overall mean strains are insignificant (less than 20% of the yielding strain of the material).
Definition of the kinetic equation form for damage under the plastic deformation
Authors: SMIRNOV S. V. , DOMILOVSKAYA T. V.
Published: December 2004

Plastic deformation of metals leads to the residual variation of the volume of the metal due to the appearance and growth of deformational defects. This process is known as ‘defect accumulation’. The intensity of this process depends on the metal properties and loading parameters. This work is concentrated first of all with experiments, used to set up the physically substantiated model of damage accumulation under complex stress states. A special technique allowed the loading of the specimens under various superimposed hydrostatic pressures (0.1–800 MPa) to simulate the process of damage accumulation under a wide range of stress states. The metal density was chosen as the characteristic of damage. The experiments support hypotheses of a linear dependence between the damage accumulation intensity and the controlling stress state index, and an inverse exponential dependence of the critical damage accumulation.
Reliability analysis of hybrid ceramic/steel gun barrels
Authors: GRUJICIC M. , DELONG J. R. , DEROSSET W. S.
Published: December 2004

ABSTRACT Failure of the ceramic gun‐barrel lining during single‐shot and burst firing events has been studied by combining a finite‐element method based thermo‐mechanical analysis with a structural reliability analysis. An initial distribution of residual stresses in the lined barrel, as introduced during shrink‐fitting of the steel jacket over the ceramic lining, is taken into account. Forced‐convection boundary conditions at the inner surface of the barrel are determined by carrying out an internal‐ballistic analysis, followed by compressible boundary‐layer modeling of the heat transfer coefficient. The results obtained reveal that due to thermal expansion of the steel jacket during single‐shot and burst ballistic events, tensile axial stresses develop in the ceramic lining near the barrel ends. These stresses are sufficiently high, particularly in the case of burst firing, that they can induce formation of circumferential cracks and, in turn, failure of the lining. Using the Weibull structural reliability analysis, the failure probability for the lining has been computed as 0.0025 and 0.0121 for the single‐round and the 10‐round firing modes, respectively. Optimization of the main design, materials and processing parameters in order to minimize the failure probability for the lining is also discussed.
Fatigue behaviour of a box‐welded joint under biaxial cyclic loading: effects of biaxial load range ratio and cyclic compressive loads in the lateral direction
Authors: TAKAHASHI I. , TAKADA A. , USHIJIMA M. , AKIYAMA S.
Published: December 2004

ABSTRACT The biaxial fatigue of a steel plate (JIS SM400B) having a box‐welded (wrap‐around) joint was experimentally studied. Special concerns were focused on the effects of the biaxial load range ratio and compressive cyclic loading in the lateral direction. The direction of fatigue crack propagation under biaxial cyclic tensile loading, which has a phase difference of π, changed according to the biaxial load range ratio, Rxy = ΔPx/ΔPy. When Rxy was less than 0.56, fatigue cracks propagated along the toe of the weld in the x‐direction because the principal tensile stress range Δσy at that location exceeded the orthogonal value Δσx at the box‐weld toe. The fatigue lives in biaxial tests related well to the data from uniaxial tests when invoking the Δσ5 criterion. However, the location and direction of Δσ5 should be chosen according to the Rxy value and the failure crack direction. An increase in Δσ5, as induced by the Poisson's ratio effect from either the out‐of‐phase tensile loading or the in‐phase compressive loading in the y‐direction, leads to an increase in fatigue damage (decrease in fatigue resistance or specifically a faster crack propagation rate), and this effect can be successfully estimated from uniaxial fatigue test data.
A procedure for estimating the total life in fretting fatigue
Authors: NAVARRO C. , GARCÍA M. , DOMÍNGUEZ J.
Published: December 2004

ABSTRACT This paper proposes a procedure for estimating the total fatigue life in fretting fatigue. It separately analyses the fatigue crack initiation and propagation lives. The correlation between crack initiation and propagation is made considering a non‐arbitrary crack initiation length provided by the model. The number of cycles to initiate a crack is obtained from the stress distribution beneath the contact zone and a multiaxial fatigue crack initiation criterion. The propagation of the crack is considered using different fatigue crack propagation laws, including some modifications in order to take the short crack growth into account. The results obtained by this method are compared with the fatigue lives obtained in various fretting fatigue tests under spherical contact with 7075‐T6 aluminium alloy.
Application of interface finite elements to three‐dimensional progressive failure analysis of adhesive joints
Authors: GONÇALVES J. P. M. , De MOURA M. F. S. F. , MAGALHÃES A. G. , De CASTRO P. M. S. T.
Published: December 2004

ABSTRACT The paper presents a new model for three‐dimensional progressive failure analysis of adhesive joints. The method uses interface elements and includes a damage model to simulate progressive debonding. The interface finite elements are placed between the adherents and the adhesive. The damage model is based on the indirect use of fracture mechanics and allows the simulation of the initiation and growth of damage at the interfaces without considering the presence of initial flaws. The application of the model to single lap joints is presented. Experimental tests were performed in aluminium/epoxy adhesive joints. Linear elastic and elastoplastic analyses were performed and the predicted failure load for the elastoplastic case agrees with experimental results.
Modern and ancient olive stands near Sagalassos (south‐west Turkey) and reconstruction of the ancient agricultural landscape in two valleys
Authors: Vermoere M. , Vanhecke L. , Waelkens M. , Smets E.
Published: December 2004

Aim To study the present‐day olive stands and their ecology in the eastern part of the territory of the ancient city of Sagalassos, to study the variation of olive pollen production and dispersal near the olive stands, to establish a modern pollen reference model, and to compare Hellenistic–Roman pollen data from two wetlands with this modern reference model.

Location Eastern part of the territory of the ancient city of Sagalassos, western Taurus mountain range in south‐west Turkey.

Methods The study is based on field survey, pollen analysis of surface samples, multivariate statistics of modern pollen data and the use of ‘modern analogues’ in comparison with Hellenistic–Roman pollen samples.

Results A field survey revealed the presence of 35 olive stands in the study area. These are mainly small‐scale stands. The olive pollen representation in the surface samples is highly variable. Two groups of modern ‘olive’ pollen spectra could be distinguished: (1) a group representing mainly olive stands from lush and moist mixed orchards; and (2) a group representing mainly olive stands from open small‐scale olive stands in combination with annual crop agriculture. Although no ‘perfect’ modern analogue was found for the Hellenistic–Roman pollen data, the fossil pollen data show similarities with modern spectra from the second group, due to the presence of relatively high pollen values for secondary anthropogenic indicators.

Main conclusion A well‐organized and diverse, but time‐ and energy‐consuming, agricultural system was maintained nearby the wetlands of Çanaklı soils, presumably to maximize the yields in both valleys.
A tribute to Claude Shannon (1916–2001) and a plea for more rigorous use of species richness, species diversity and the ‘Shannon–Wiener’ Index
Authors: Spellerberg Ian F. , Fedor Peter J.
Published: December 2004

In the literature, the terms species richness and species diversity are sometimes used interchangeably. We suggest that at the very least, authors should define what they mean by either term. Of the many species diversity indices used in the literature, the Shannon Index is perhaps most commonly used. On some occasions it is called the Shannon–Wiener Index and on other occasions it is called the Shannon–Weaver Index. We suggest an explanation for this dual use of terms and in so doing we offer a tribute to the late Claude Shannon (who passed away on 24 February 2001).
Diversity at hydrothermal vents
Authors: Tsurumi Maia
Published: December 2004

AimTo describe patterns of hydrothermal vent community diversity and dispersion at the intersegment scale (> 100 km).

LocationThe area discussed is an approximately 170 km portion of the Juan de Fuca Ridge, a mid‐ocean ridge in the north‐east Pacific Ocean.

MethodsSamples of benthic invertebrates from hydrothermal vents on three segments of the Juan de Fuca are examined for community characteristics such as diversity, abundance and distribution.

ResultsSpecies richness (55 species) and evenness are low. If the macrofauna only are considered, species richness is about 30% lower than when meiofauna are also considered. The geometric series describes the species‐abundance distribution. The relationship between vent species’ distribution and abundance is significantly positive (r2 = 0.818;P < 0.001). Alpha diversity is lower in patchy habitat than continuous habitat and gamma diversity is similar for both habitat types. Beta diversity is higher in patchy habitat. Local diversity is linearly related to regional diversity.

Main conclusionsSpecies richness is comparable to other highly disturbed systems. The geometric series species abundance model implies some degree of niche pre‐emption in the vent community and is consistent with the suggestion that the geometric series distribution can be found in species‐poor environments that experience harsh conditions and are structured by relatively few environmental factors. Species distribution and abundance are highly correlated. The regional species pool affects local vent diversity. Vent diversity studies should be conducted on at least the ridge scale.
Hundred‐year decline of North Atlantic predatory fishes
Authors: Christensen Villy , Guénette Sylvie , Heymans Johanna J , Walters Carl J , Watson Reginald , Zeller Dirk , Pauly Daniel
Published: December 2004

We estimate the biomass of high‐trophic level fishes in the North Atlantic at a spatial scale of 0.5° latitude by 0.5° longitude based on 23 spatialized ecosystem models, each constructed to represent a given year or short period from 1880 to 1998. We extract over 7800 data points that describe the abundance of high‐trophic level fishes as a function of year, primary production, depth, temperature, latitude, ice cover and catch composition. We then use a multiple linear regression to predict the spatial abundance for all North Atlantic spatial cells for 1900 and for each year from 1950 to 1999. The results indicate that the biomass of high‐trophic level fishes has declined by two‐thirds during the last 50‐year period, and with a factor of nine over the century. Catches of high‐trophic level fishes increased from 2.4 to 4.7 million tonnes annually in the late 1960s, and subsequently declined to below 2 million tonnes annually in the late 1990s. The fishing intensity for high‐trophic level fishes tripled during the first half of the time period and remained high during the last half of the time period. Comparing the fishing intensity to similar measures from 35 assessments of high‐trophic level fish populations from the North Atlantic, we conclude that the trends in the two data series are similar. Our results raise serious concern for the future of the North Atlantic as a diverse, healthy ecosystem; we may soon be left with only low‐trophic level species in the sea.
Fluctuation in stock properties of north‐east Arctic cod related to long‐term environmental changes
Authors: Godø O R
Published: December 2004

From a historic perspective, the north‐east Arctic cod stock, which is found in the Barents Sea–Svalbard region, has been the most productive gadoid stock in the Atlantic. Variation in catch has always been large, but during the last 10–15 years catch and stock abundance have reached the lowest level on record. Three major causes of variation have been discussed: (i) stock reduction through exploitation; (ii) environmental influences on recruitment; and (iii) species interaction effects on maturation, growth and mortality. In addition, interactions among these three sources might be important. The influence of each specific factor is difficult to evaluate from incidental observations and short‐term time series. In this respect, the time series on catches and on biological and environmental information of this stock, which partly extend back to the 19th century, occupy a unique position in comparison to data on most other stocks. In this paper, fluctuations in catch and stock abundance are compared with changes in recruitment, size/age and growth. This information is discussed in view of historic variation in ecology and environment. The stock has been under particularly high exploitation pressure since the mid‐1970s. Further, large changes in growth rates and poor recruitment to the commercially exploited stock are characteristic of late 1980s and throughout the 1990s. The analysis shows that substantial long‐term variation might underlie short‐term variability, and more importantly, that long‐term changes roughly coincide with similar fluctuations in the environment. Such factors might substantially affect the relationship between spawning stock and recruitment, which is also apparent from the difference in conclusions reached by various published studies. Consequently, it is suggested that using a steady‐state perspective for the population dynamics may lead to mismanagement and to a reduction of the long‐term yield from this stock.
The role of learning in fish orientation
Authors: Odling‐Smee Lucy , Braithwaite Victoria A
Published: December 2004

Past research on fish orientation and migration has tended to focus on genetically fixed patterns of behaviour. However, in most aquatic environments, the physical landscape as well as biologically important locations will be subject to varying degrees of change, favouring an ability to learn. Here, we review the evidence from field and laboratory‐based experiments that fish can and do use learning and memory to orientate within their natural environments, relying on information from a diverse array of different sources. Comparisons of different species and populations suggest that fish may be predisposed to learn specific associations at specific times or places, appropriate for the particular navigational problems that they are likely to encounter.
Growth and albitization of K‐feldspar in crystalline rocks in the shallow crust: a tracer for fluid circulation during exhumation?
Authors: Holness M. B.
Published: December 2004

A general feature of medium‐ to coarse‐grained, sheet‐silicate bearing, quartzo‐feldspathic rocks of either metamorphic or igneous affinity is the retrograde development of lenses of pure K‐feldspar at the grain boundaries between sheet silicate (0 0 1) faces and original feldspar grains. The growth of these lenses acts to displace and deform the sheet silicate grain by a force of crystallization, although the substrate feldspar and adjacent quartz are not deformed. Subsequent to the growth of the lenses they are replaced to variable degrees by pure albite, which grows into the lens from the substrate feldspar behind an irregular replacement front. The composition and texture of both K‐feldspar and replacive albite suggest a strong affinity with authigenic feldspars, although it is considered likely that the K‐feldspar of the lenses is derived from low‐temperature biotite‐breakdown reactions. A model is proposed whereby the lenses grow into open pores at dilatant sites in response to infiltration of aqueous fluids as the crystalline rocks are exhumed under brittle conditions. Continued circulation of infiltrating fluids in a temperature gradient results in the replacement of K‐feldspar by albite via an alkali exchange process. The lenses point to a significant grain‐scale permeability in crystalline rock at shallow levels in the crust.
Effects of selected salts on the cooking time, protein content and sensory properties of African yam beans and cowpeas
Authors: Onwuka U. N. , Okala O.
Published: December 2004

Legumes (African yam beans and cowpeas) were boiled in tap water with different salts: NaHCO3, NaCl, CaCl2, Akanwa (trona1) at different concentrations2 of 0.2, 0.4 and 0.6 g/L, and the cooking time was monitored. Proximate analysis was conducted before and after treatment to determine the effects of these salts on the protein content. Sensory properties were also evaluated. Cooking times for the samples were significantly different (P < 0.05) when cooked in different concentrations of salts. The addition of Akanwa resulted in a shortening of the cooking time but the legumes were darkened. NaHCO3 and NaCl also reduced the cooking time while CaCl2 significantly increased the cooking time. The salts also affected the sensory properties. Results of protein analysis showed a significant difference between the treated samples at a concentration of 0.6 g/L. This suggests that heat and salt influence the protein content of legumes when cooked. NaHCO3‐treated samples required the least cooking time but samples treated with NaCl were more accepted. These results and their implications are important for those involved with emergency or disaster feeding.
Surface chemistry and reactivity of bacteriogenic iron oxides from Axial Volcano, Juan de Fuca Ridge, north‐east Pacific Ocean
Authors: Kennedy C. B. , Martinez R. E. , Scott S. D. , Ferris F. G.
Published: December 2004

Iron oxides were collected from the caldera of Axial Volcano, a site of hydrothermal vent activity along the Juan de Fuca Ridge. Mineralogical inspection using X‐ray diffraction (XRD) revealed the majority of samples to be 2‐line ferrihydrite, with one of the samples corresponding to poorly ordered goethite. Examination using environmental scanning electron microscopy (ESEM) found the constituents of the iron oxides to consist predominantly of bacterial‐like structures that resembled the iron oxidizing bacteria Leptothrix ochracea, Gallionella ferruginea and a novel PV‐1 strain. X‐ray photoelectron spectroscopy (XPS) detected the presence of Fe, O, C, N, Ca, Si and P on all the samples with the exception of poorly ordered goethite, where Ca and P were absent, in addition to a weak N peak. Binding energy shifts of the Fe 2p and O 1s peaks were indicative of ferrihydrite and hydroxyl functional groups, while the presence and speciation of the C 1s peak was attributed to the presence of bacteria. Use of acid‐base titration data modelling in conjunction with a linear programming regression method (LPM) indicated that the iron oxides are composed of heterogeneous surface functional groups. Differences in iron oxide reactivity values correlated with differences in the bacterial and mineral fabric of the samples. The diverse surface chemistry and high reactivity of these iron oxides may be important in the global cycling of various elements throughout the oceans due to their presence along widespread mid‐ocean ridges.
Metabolic therapy in the treatment of ischaemic heart disease: the pharmacology of trimetazidine
Authors: Stanley William C. , Marzilli Mario
Published: December 2004

The primary result of myocardial ischaemia is reduced oxygen consumption and adenosine triphosphate (ATP) formation in the mitochondria, and accelerated anaerobic glycolysis, lactate accumulation and cell acidosis. Classic pharmacotherapy for demand‐induced ischaemia is aimed at restoring the balance between ATP synthesis and breakdown by increasing the oxygen delivery (i.e. with long acting nitrates or Ca2+ channel antagonist) or by decreasing cardiac power by reducing blood pressure and heart rate (i.e. with β‐blocker or Ca2+ channel antagonist). Animal studies show that fatty acids are the primary mitochondrial substrate during moderate severity myocardial ischaemia, and that they inhibit the oxidation of carbohydrate and drive the conversion of pyruvate to lactate. Drugs that partially inhibit myocardial fatty acid oxidation increase carbohydrate oxidation, which results in reduced lactate production and a higher cell pH during ischaemia. Trimetazidine (1‐[2,3,4‐trimethoxibenzyl]‐piperazine) is the first and only registered drug in this class, and is available in over 90 countries world‐wide. Trimetazidine selectively inhibits the fatty acid β‐oxidation enzyme 3‐keto‐acyl‐CoA dehydrogenase (3‐KAT), and is devoid of any direct haemodynamic effects. In double‐blind placebo‐controlled trials trimetazidine significantly improved symptom‐limited exercise performance in stable angina patients when used either as monotherapy or in combination with β‐blockers or Ca2+ channel antagonists. Given available evidence, trimetazidine is an excellent alternative to classic haemodynamic agents, and is unique in its ability to reduce symptoms of angina when used in patients resistant to a haemodynamic treatment as vasodilators, β‐blockers or Ca2+ channel antagonists.
The new drug combinations: their place in the treatment of uncomplicated Plasmodium falciparum malaria
Authors: Danis Martin , Bricaire François
Published: December 2004

Malaria is a leading cause of morbidity and mortality in developing countries. Selection of mutant Plasmodium falciparum malaria strains under drug pressure has led to the development of drug resistance. There is a pressing need for effective, safe, practicable drug combinations that hve lower selection pressure. A review of the mein drug combinations, which are recently registered or are still under development, was undertaken, with special attention to the atovaquone–proguanil and artemether–lumefantrine combination.
Migraine Headaches in Adolescents: A Five‐Year Follow‐Up Study
Authors: Camarda Rosolino , Monastero Roberto , Santangelo Giuseppe , Raimondo Domenico , Puma Domenico , Pipia Carmela , Camarda Lawrence K. C. , Camarda Cecilia , Raieli Vincenzo
Published: December 2004

Background and Objectives.—Longitudinal studies of juvenile migraine are very few. We investigated the prevalence and evolution over 5 years of migraine without aura (MWOA) and migraineous disorder (MD) in an adolescent population.

Methods.—Sixty‐four subjects (34 girls and 30 boys, mean age 17.3±1.1 years) out of 80 selected in our 1989 epidemiological survey were included in the study. The diagnostic criteria of the International Headache Society were used in both studies.

Results.—Thirty‐two of 64 subjects (50%) had MWAO, 18 (28.1%) had MD, and 14 (21.9%) had headache not classifiable (HnC). Our results show that MWOA persisted in 56.2%, converted to MD or HnC in 9.4% and 3.1% of cases, respectively, changed to episodic tension‐type headache (ETTH) in 12.5%, and remitted in 18.8%. MD persisted in 11.1%, converted to MWOA or HnC in 27.8% and 5.5% of cases, respectively, changed to ETTH in 11.1%, and remitted in 44.5%. HnC persisted in 14.3%, converted to MD or MWOA in 21.4% and 14.3% of cases, respectively, changed to ETTH in 14.3%, and remitted in 35.7%.

Conclusions.—Our data indicate that juvenile‐onset MWOA and MD may change in character over time, generally with a favorable prognosis.