bluuebunny/crossref_metadata_2025 huggingface dataset:
Selecting Differentially Expressed Genes from Microarray Experiments
Authors: Pepe Margaret Sullivan , Longton Gary , Anderson Garnet L. , Schummer Michel
Published: December 2004

Summary.  High throughput technologies, such as gene expression arrays and protein mass spectrometry, allow one to simultaneously evaluate thousands of potential biomarkers that could distinguish different tissue types. Of particular interest here is distinguishing between cancerous and normal organ tissues. We consider statistical methods to rank genes (or proteins) in regards to differential expression between tissues. Various statistical measures are considered, and we argue that two measures related to the Receiver Operating Characteristic Curve are particularly suitable for this purpose. We also propose that sampling variability in the gene rankings be quantified, and suggest using the “selection probability function,” the probability distribution of rankings for each gene. This is estimated via the bootstrap. A real dataset, derived from gene expression arrays of 23 normal and 30 ovarian cancer tissues, is analyzed. Simulation studies are also used to assess the relative performance of different statistical gene ranking measures and our quantification of sampling variability. Our approach leads naturally to a procedure for sample‐size calculations, appropriate for exploratory studies that seek to identify differentially expressed genes.
Data Reduction Using a Discrete Wavelet Transform in Discriminant Analysis of Very High Dimensionality Data
Authors: Qu Yinsheng , Adam Bao‐ling , Thornquist Mark , Potter John D. , Thompson Mary Lou , Yasui Yutaka , Davis John , Schellhammer Paul F. , Cazares Lisa , Clements MaryAnn , Wright George L. , Feng Ziding
Published: December 2004

Summary.  We present a method of data reduction using a wavelet transform in discriminant analysis when the number of variables is much greater than the number of observations. The method is illustrated with a prostate cancer study, where the sample size is 248, and the number of variables is 48,538 (generated using the ProteinChip technology). Using a discrete wavelet transform, the 48,538 data points are represented by 1271 wavelet coefficients. Information criteria identified 11 of the 1271 wavelet coefficients with the highest discriminatory power. The linear classifier with the 11 wavelet coefficients detected prostate cancer in a separate test set with a sensitivity of 97% and specificity of 100%.
Estimating Causal Treatment Effects from Longitudinal HIV Natural History Studies Using Marginal Structural Models
Authors: Ko Hyejin , Hogan Joseph W. , Mayer Kenneth H.
Published: December 2004

Summary.  Several recently completed and ongoing studies of the natural history of HIV infection have generated a wealth of information about its clinical progression and how this progression is altered by therepeutic interventions and environmental factors. Natural history studies typically follow prospective cohort designs, and enroll large numbers of participants for long‐term prospective follow‐up (up to several years). Using data from the HIV Epidemiology Research Study (HERS), a six‐year natural history study that enrolled 871 HIV‐infected women starting in 1993, we investigate the therapeutic effect of highly active antiretroviral therapy regimens (HAART) on CD4 cell count using the marginal structural modeling framework and associated estimation procedures based on inverse‐probability weighting (developed by Robins and colleagues). To evaluate treatment effects from a natural history study, specialized methods are needed because treatments are not randomly prescribed and, in particular, the treatment‐response relationship can be confounded by variables that are time‐varying. Our analysis uses CD4 data on all follow‐up visits over a two‐year period, and includes sensitivity analyses to investigate potential biases attributable to unmeasured confounding. Strategies for selecting ranges of a sensitivity parameter are given, as are intervals for treatment effect that reflect uncertainty attributable both to sampling and to lack of knowledge about the nature and existence of unmeasured confounding. To our knowledge, this is the first use in “real data” of Robins's sensitivity analysis for unmeasured confounding (Robins, 1999a, Synthese121, 151–179). The findings from our analysis are consistent with recent treatment guidelines set by the U.S. Panel of the International AIDS Society (Carpenter et al., 2000, Journal of the American Medical Association280, 381–391).
Accounting for Nonignorable Verification Bias in Assessment of Diagnostic Tests
Authors: Kosinski Andrzej S. , Barnhart Huiman X.
Published: December 2004

Summary. A “gold” standard test, providing definitive verification of disease status, may be quite invasive or expensive. Current technological advances provide less invasive, or less expensive, diagnostic tests. Ideally, a diagnostic test is evaluated by comparing it with a definitive gold standard test. However, the decision to perform the gold standard test to establish the presence or absence of disease is often influenced by the results of the diagnostic test, along with other measured, or not measured, risk factors. If only data from patients who received the gold standard test were used to assess the test performance, the commonly used measures of diagnostic test performance—sensitivity and specificity—are likely to be biased. Sensitivity would often be higher, and specificity would be lower, than the true values. This bias is called verification bias. Without adjustment for verification bias, one may possibly introduce into the medical practice a diagnostic test with apparent, but not truly, high sensitivity. In this article, verification bias is treated as a missing covariate problem. We propose a flexible modeling and computational framewzork for evaluating the performance of a diagnostic test, with adjustment for nonignorable verification bias. The presented computational method can be utilized with any software that can repetitively use a logistic regression module. The approach is likelihood‐based, and allows use of categorical or continuous covariates. An explicit formula for the observed information matrix is presented, so that one can easily compute standard errors of estimated parameters. The methodology is illustrated with a cardiology data example. We perform a sensitivity analysis of the dependency of verification selection process on disease.
Modeling Breastmilk Infectivity in HIV‐1 Infected Mothers
Authors: Richardson Barbra A. , Hughes James P.
Published: December 2004

Summary.  Estimation of breastmilk infectivity in HIV‐1 infected mothers is difficult because transmission can occur while the fetus is in utero, during delivery, or through breastfeeding. Since transmission can only be detected through periodic testing, however, it may be impossible to determine the actual mode of transmission in any individual child. In this article we develop a model to estimate breastmilk infectivity, along with the probabilities of in‐utero and intrapartum transmission. In addition, the model allows separate estimation of early and late breastmilk infectivity, and individual variation in maternal infectivity. Methods for hypothesis testing of binary risk factors and a method for assessing goodness of fit are also described. Data from a randomized trial of breastfeeding versus formula feeding among HIV‐1 infected mothers in Nairobi, Kenya, are used to illustrate the methods.
Comment on Cowling's “Spatial Methods for Line Transect Surveys”
Authors: Aldrin Magne , Holden Marit , Schweder Tore
Published: December 2004

Summary. We consider the problem of estimating the parameters of a two‐dimensional Neyman‐Scott process, from data collected through a line transect survey.Cowling(1998,Biometrics54,828–839) suggested an estimation method based on a one‐dimensional K‐function along the transect line. However, her expression for the theoretical K‐function is wrong. In this article, we correct her K‐function.
Latent Class Model Diagnosis from a Frequentist Point of View
Authors: Formann Anton K.
Published: December 2004

Summary. This is in response toGarrett and Zeger(2000,Biometrics56,1055–1067) who, within the Bayesian framework, developed mainly graphical methods for latent class model diagnosis. Possible problems with this approach, and with its application to both generated and empirical data, are pointed out. The impact of the proposed tools cannot be understood by their reader, as no comparisons are made to results obtainable using established methods for latent class model diagnosis; this applies especially to overall goodness‐of‐fit tests, for which alternatives (bootstrap, Rudas‐Clogg‐Lindsay index of fit) are mentioned. Further, in one case of generated data, the methods proposed by Garrett and Zeger seem to give problematic results as to identifiability; in the case of the empirical data on major depression, they lead to accepting a suboptimal three‐class model. In the latter case, one can be rather sure that an identifiable, well‐fitting latent class model could have been identified—if Garrett and Zeger had also considered restricted latent class models.
What kind of quantitative methods for what kind of geography?
Authors: Keylock Christopher J , Dorling Danny
Published: December 2004

This paper asks why we teach what we teach to geography undergraduates in quantitative methods courses. We re‐consider the origins of quantitative geography and note how partial and historically contingent the traditional syllabus is. From this basis, we suggest that other approaches should be considered in order to provide a broader training in quantitative methods. We then propose an example syllabus that attempts to integrate a range of quantitative methodologies within a common, applied context that is also connected to relevant social, economic and political issues. We conclude that students with a better understanding of methods in physical and social science could be very valuable to the betterment of society, but to achieve this may require a change to our quantitative methods teaching.
Academic publishing as ‘creative’ industry, and recent discourses of ‘creative economies’: some critical reflections
Authors: Gibson Chris , Klocker Natascha
Published: December 2004

This paper continues recent discussions on the (geo)politics of the production of academic knowledges, in relation to the recent rise of narratives of ‘the creative economy’. Creativity and the ‘creative industries’ are increasingly common components of urban economic development discourse, especially following the release of a set of key books – most notably Charles Landry's The Creative City (2000), and Richard Florida's The Rise of the Creative Class (2002) – that have become popular among economic development planners and cultural policy makers. This paper focuses on the traffic of these books, and their authors, beyond the Anglo‐American core. It also briefly discusses policy discourses interpreted from these texts. It is principally, though, a critique of the ways in which academic knowledges circulate, stemming from theorization of academics as creative producers, and of knowledge production as part of the creative economy. The article seeks to critique the means by which particular northern economic knowledges become normative, framed as universal and ‘global’, and are distributed and absorbed via intellectual ‘scenes’ and an academic ‘celebrity’ circuit.
From flexibility to accommodation? Disabled people and the reinvention of paid work
Authors: Wilton Robert D
Published: December 2004

Scholarship on ‘flexible’ work and changing organizational cultures has had little to say about the implications of these developments for disabled people. Drawing on in‐depth interviews, this paper examines the ways in which disabled workers struggle over accommodations in contemporary workplaces. Analysis reveals a number of themes concerning training, speed at work, and emotional and aesthetic labour. At their core, these themes concern the ability of workers to exercise control over the labour process. Efforts to obtain accommodation are frustrated by multiple strategies that include people's propensity to self‐discipline in the interests of achieving a valued identity through paid work. The paper argues in conclusion that accommodation, as both discourse and practice, offers a conceptual resource for rethinking contemporary employment with implications for both disabled and non‐disabled workers.
Regional spaces, spaces of regionalism: territory, insurgent politics and the English question
Authors: Jones Martin , MacLeod Gordon
Published: December 2004

Amid the globalization of economic life and a myriad of powerful challenges to Westphalian traditions of political statehood, it is now routinely contended that regions are ‘in resurgence’. Nonetheless, much of the debate on this purported regional renaissance is bedevilled by confusion over what scholars and activists mean by regions and an analogous mystification as to why some regions are ‘successful’, ‘lagging’ or ‘different’. Our paper aims to instil some coherence to this debate by distinguishing between what we term regional spaces and spaces of regionalism. It then draws on this distinction to explore the institutionalization of England's South West region, highlighting some tensions which prevail over its economic future, its political representation, its territorial shape and cultural vernacular. In undertaking this, we demonstrate how the formation of any given regional map is reflective – and indeed constitutive – of an unevenly developing, often overlapping and superimposing mosaic of economic practices, political mobilizations, cultural performances and institutional accomplishments. This prompts us to question the currently fashionable inclination to fully jettison a scalar and/or territorial approach to the theory and practice of spatiality in favour of relational/topological/non‐territorial approaches.
Selling civilization: toward a cultural analysis of America's economic empire in the late nineteenth and early twentieth centuries
Authors: Domosh Mona
Published: December 2004

This essay builds on work that is exploring the convergence of economic and cultural approaches to understanding imperialism through an examination of the particular case of American commercial expansion in the late nineteenth and early twentieth centuries. Based on my archival research into the promotional and practical strategies of five of the largest American companies that were international in sales, I suggest some of the ways that an analysis of commercial imperial representations of, and knowledges about, race, gender and civilization adds to our understanding of the multiplicity of imperialisms. I argue that examining these multiplicities can help contribute to a critical postcolonial perspective.
‘Globalizing’ regional development: a global production networks perspective
Authors: Coe Neil M , Hess Martin , Yeung Henry Wai‐chung , Dicken Peter , Henderson Jeffrey
Published: December 2004

Recent literature concerning regional development has placed significant emphasis on local institutional structures and their capacity to ‘hold down’ the global. Conversely, work on inter‐firm networks – such as the global commodity chain approach – has highlighted the significance of the organizational structures of global firms’ production systems and their relation to industrial upgrading. In this paper, drawing upon a global production networks perspective, we conceptualize the connections between ‘globalizing’ processes, as embodied in the production networks of transnational corporations, and regional development in specific territorial formations. We delimit the ‘strategic coupling’ of the global production networks of firms and regional economies which ultimately drives regional development through the processes of value creation, enhancement and capture. In doing so, we stress the multi‐scalarity of the forces and processes underlying regional development, and thus do not privilege one particular geographical scale. By way of illustration, we introduce an example drawn from recent research into global production networks in East Asia and Europe. The example profiles the investments of car manufacturer BMW in Eastern Bavaria, Germany and Rayong, Thailand, and considers their implications for regional development.
Triangulating the borderless world: geographies of power in the Indonesia–Malaysia–Singapore Growth Triangle
Authors: Sparke Matthew , Sidaway James D , Bunnell Tim , Grundy‐Warr Carl
Published: December 2004

This paper argues that the Indonesia–Malaysia–Singapore Growth Triangle makes manifest the complex geographies of power that subvert efforts to read cross‐border regionalization as a straightforward geographical corollary of ‘globalization’. As such, the region needs to be examined not simply as a complementary transborder assemblage of land, labour and capital, but rather as a palimpsest in which the imagined geographies of cross‐border development and the economic geographies of their uneven spatial fixing on the ground are mediated by complex cultural and political geographies. We seek to unpack these by triangulating how the geographies of capital (including its uneven development and its links to the geo‐economics of intra‐regional competition), land (including post‐colonial relations across the region, the geopolitics of land reclamation and the enclaved landscapes of tourism) and labour (including the divergent itineraries of migrant workers) overlay and complicate one another in the region. By charting these complex triangulations of space and place, we seek to problematize narratives of the Growth Triangle as an exemplary embodiment of the ‘borderless world’.
Degenerate neuronal systems sustaining cognitive functions
Authors: Noppeney Uta , Friston Karl J. , Price Cathy J.
Published: December 2004

The remarkable resilience of cognitive functions to focal brain damage suggests that multiple degenerate neuronal systems can sustain the same function either via similar mechanisms or by implementing different cognitive strategies. In degenerate functional neuroanatomy, multiple degenerate neuronal systems might be present in a single brain where they are either co‐activated or remain latent during task performance. In degeneracy over subjects, a particular function may be sustained by only one neuronal system within a subject, but by different systems over subjects. Degeneracy over subjects might have arisen from (ab)normal variation in neurodevelopmental trajectories or long‐term plastic changes following structural lesions. We discuss how degenerate neuronal systems can be revealed using (1) intersubject variability, (2) multiple lesion studies and (3) an iterative approach integrating information from lesion and functional imaging studies.
Graft repair of the peroneal nerve restores histochemical profile after long‐term reinnervation of the rat extensor digitorum longus muscle in contrast to end‐to‐end repair
Authors: Lehnert M. , Maier B. , Frank J. M. , Steudel W. I. , Marzi I. , Mautes A.
Published: December 2004

Declining motor function is a prominent feature of ageing physiology. One reason for this is a reduction in plasticity that normally compensates for ongoing reorganization of motor units under physiological conditions. Previous work from our laboratory has shown that microsurgical repair of the transected peroneal nerve is followed by considerable changes in the histochemical profile of the reinnervated extensor digitorum longus (EDL) muscle and that these changes are dependent on both the time and the type of nerve repair. At 6 months postoperatively, a trend toward reversibility could be discerned. In the present work, we analysed the long‐term reorganization of histochemical motor unit distribution patterns 15 months after performing either end‐to‐end repair or grafting of the peroneal nerve in 3‐month‐old rats. In addition, the EDL muscles of an age‐matched control group (age 18 months) were analysed for age‐dependent changes. We observed a loss of histochemical organization of motor units leading to an additional fibre type (SDH‐INT) in the control group. Fifteen months after end‐to‐end repair, the histochemical profile showed a decrease in fibre type IIA and an increase in fibre type SDH‐INT (P < 0.05), indicating a profound histochemical disorganization of motor units. In contrast, nerve grafting largely restored the histochemical profile of reinnervated EDL muscles. Fibre type grouping was present after both types of nerve repair. These findings show that reorganization of the histochemical profile in reinnervated muscles is dependent on the time and type of nerve repair and is long lasting. In this study, grafting provided superior results compared with end‐to‐end repair. These long‐term results after peripheral nerve repair are influenced by age‐dependent changes. Accordingly, nerve repair reduces the normal functional plasticity of motor unit organization. This reduction is enhanced by increasing age.
Craniofacial variability and morphological integration in mice susceptible to cleft lip and palate
Authors: Hallgrímsson Benedikt , Dorval Curtis J. , Zelditch Miriam Leah , German Rebecca Z.
Published: December 2004

A/WySnJ mice are an inbred strain that develops cleft lip with or without cleft palate (CL/P) with a frequency of 25–30% and a predominantly unilateral expression pattern. As in humans, the pattern of incomplete penetrance, and variable and frequent unilateral expression suggests a role for altered regulation of variability (developmental stability, canalization and developmental integration) during growth. We compared both mean and variability parameters for craniofacial shape and size among A/WySnJ mice, a strain that does not develop CL/P (C57BL/6J) and their F1 cross. We show that adult A/WySnJ mice that do not express cleft lip exhibit decreased morphological integration of the cranium and that the co‐ordination of overall shape and size variation is disrupted compared with both C57BL/6J mice and the F1 cross. The decrease in integration is most pronounced in the palate and face. The absence of this pattern in the F1 cross suggests that it is determined by recessive genetic factors. By contrast, the shape differences between the strains, which are thought to predispose A/WySnJ mice to CL/P, show a range of dominance which suggests a polygenic basis. We suggest that decreased integration of craniofacial growth may be an aetiological factor for CL/P in A/WySnJ mice.
On the role of general system theory for functional neuroimaging
Authors: Stephan Klaas Enno
Published: December 2004

One of the most important goals of neuroscience is to establish precise structure–function relationships in the brain. Since the 19th century, a major scientific endeavour has been to associate structurally distinct cortical regions with specific cognitive functions. This was traditionally accomplished by correlating microstructurally defined areas with lesion sites found in patients with specific neuropsychological symptoms. Modern neuroimaging techniques with high spatial resolution have promised an alternative approach, enabling non‐invasive measurements of regionally specific changes of brain activity that are correlated with certain components of a cognitive process. Reviewing classic approaches towards brain structure–function relationships that are based on correlational approaches, this article argues that these approaches are not sufficient to provide an understanding of the operational principles of a dynamic system such as the brain but must be complemented by models based on general system theory. These models reflect the connectional structure of the system under investigation and emphasize context‐dependent couplings between the system elements in terms of effective connectivity. The usefulness of system models whose parameters are fitted to measured functional imaging data for testing hypotheses about structure–function relationships in the brain and their potential for clinical applications is demonstrated by several empirical examples.
Overwinter changes in mass and lipid content of Perca fluviatilis and Gymnocephalus cernuus
Authors: Eckmann R.
Published: December 2004

The body condition, lipid reserves and mortality of 0 and 1 year‐old perch Perca fluviatilis and ruffe Gymnocephalus cernuus, sampled during the winter in Lake Constance, Germany, were compared. Length‐frequency analyses did not provide evidence for overwinter mortality in either species. The fresh and dry mass of perch as well as their lipid contents decreased during winter, while ruffe were heavier and contained more lipid at the end of the winter. The superior performance of ruffe was mainly attributed to its sensory capabilities, which allowed it to ingest zoobenthos throughout the winter, while the zooplankton feeding of perch was constrained by low light levels. In lakes that undergo a process of re‐oligotrophication, this advantage of ruffe over perch may be even more pronounced, since lower food supply during the growth season and thus lower fish lipid content at the start of winter is probably better tolerated by ruffe than by perch.
Enhancement of pH‐resistant iron‐binding activity in supernatants of rainbow trout blood leucocytes by in vitro treatment with phorbol‐12‐myristate‐13‐acetate
Authors: Cecchini S. , Caputo A. R. , Mecca F.
Published: December 2004

Leucocyte lysates from rainbow trout Oncorhynchus mykiss showed an iron‐binding activity that was retained even if the samples were exposed to an acid pH (4·5). Iron‐binding activity of leucocyte supernatants was enhanced by the presence of 1 μg ml−1 phorbol‐12‐myristate‐13‐acetate in the cell medium.
Otolith size and its relationship with colour patterns and sound production
Authors: Cruz A. , Lombarte A.
Published: December 2004

A comparative, morphometric study was made of the 185 sagitta otoliths from 18 species belonging to four coastal perciform families of the north‐west Mediterranean: the Labridae, Sparidae, Haemulidae and Sciaenidae. Species with relatively large otoliths belonged to groups considered specialists in sound production (sciaenids and haemulids), while those with small otoliths belonged to groups that rely on bright or contrasted colour patterns for visual communication (labrids). In sparids, species with clear body marks had smaller otoliths than species without dark stripes or dots. These findings support the hypothesis that otolith size is related to hearing ability in the inner ear.
Ontogenetic patterns of habitat use by fishes within the main channel of an Australian floodplain river
Authors: King A. J.
Published: December 2004

The ontogenetic patterns of habitat use by a community of fishes in the main channel of the Broken River, an Australian lowland river, was investigated. Stratified sampling was conducted fortnightly across six habitat types throughout the spring‐summer period within the main channel. As predicted by the ‘low flow recruitment hypothesis’, backwaters and still littoral habitats were important nursery habitats for most species. These habitats were found to be used by some species throughout all stages of their life cycle, while other species showed clear ontogenetic shifts in habitat preference. Only one species, Murray cod Maccullochella peelii peelii, was never found in backwaters. This study confirms the significance of main channel habitats in the rearing of larvae of some riverine fish species, and emphasizes the importance of considering the habitat requirements of all stages of a fish's life cycle in the management and restoration of rivers and streams.
The use of egg chorion glycoprotein of Epinephelus malabaricus for egg identification
Authors: Chiou L. M. , Chung M. C. , Tung P. G. , Hsu T. , Yang J. S.
Published: December 2004

An immuno‐probe against a glycoprotein in the egg chorion was developed for egg identification. The 97 kD glycoprotein in the chorion of unfertilized eggs of Epinephelus malabaricus was isolated and separated by SDS‐PAGE as an antigen to induce antibody from rabbit. The reactivity of the antibody as the immuno‐probe to E. malabaricus eggs was significantly positive, and was specific in that it did not react with the eggs of other fish species. The immuno‐probe should be useful in identifying the eggs of E. malabaricus among mixed egg populations.
Parasites of Argentine hake in the Argentine Sea: population and infracommunity structure as evidence for host stock discrimination
Authors: Sardella N. H. , Timi J. T.
Published: December 2004

The use of parasites as biological tags allowed the identification of three stocks of Argentine hake Merluccius hubbsi in the south‐west Atlantic. A total of 344 fish caught in the Argentine‐Uruguayan Common Fishing Zone, San Matías Gulf, San Jorge Gulf and Patagonian Shelf, were examined for parasites and 26 species were found. Univariate analysis on both parasite populations and infracommunity descriptors, as well as a discriminant analysis, allowed the identification of three separate stocks, one composed of hake from the Argentine‐Uruguayan Common Fishing Zone, a second by fish from San Matías Gulf and a third comprising samples from both San Jorge Gulf and the Patagonian Shelf. Northern samples were characterized by low values of prevalence for most parasite species, with the exception of Corynosoma australe and Grillotia sp. 1. Among Patagonian hake, Anisakis simplex showed similar values of prevalence in all zones, fish from San Matías Gulf were characterized by Kudoa rosenbuschi, Grillotia sp. 1 and Contracaecum sp. Among all compared areas, San Jorge Gulf and the Patagonian Shelf were the most similar, sharing most of their biological indicators (Grillotia sp. 2, Pseudophyllidea sp. 1 plerocerci and Hysterothylacium aduncum); therefore, the hypothesis on the presence of a separate stock in San Jorge Gulf could not be confirmed. Varying environmental conditions and their influence on the distribution of both zooplankton and other hosts involved in the life‐cycles of parasites could be determinant factors for the differences observed among hake stocks.
Biotic and abiotic influences on the recruitment of male perch in Windermere, U.K.
Authors: Paxton C. G. M. , Winfield I. J. , Fletcher J. M. , George D. G. , Hewitt D. P.
Published: December 2004

PerchPerca fluviatilisrecruitment (based on the catch per unit effort, CPUE, of 2 or 3 year male perch) varied greatly from 1941 to 1995 in Windermere, U.K., with year class strengths strongly synchronous between the two basins of this temperate, mesotrophic lake. Statistically significant modified Ricker (Saila‐Lorda) stock‐recruitment curves could be fitted to data from three of four sampling sites, while the presence of widespread disease and late summer water temperature were also important explanatory variables. Multiple‐regression analyses revealed no influences of pikeEsox luciusrecruitment, zooplankton abundance, or the climatic influences (i.e. North Atlantic Oscillation and displacement of the summer position of the Gulf Stream) on perch recruitment over and above associated influences from temperature. Fitted models realistically explained up toc. 60% of the observed variation in perch recruitment.
Effects of environmental variables on fish feeding ecology: implications for the performance of baited fishing gear and stock assessment
Authors: Stoner A. W.
Published: December 2004

The effectiveness of baited fishing gear ultimately depends upon behaviour of the target species – activity rhythms, feeding motivation, and sensory and locomotory abilities. While any environmental parameter that mediates feeding or locomotion can have an important influence on the active space presented by the bait and fish catchability, few biologists have considered how such variation in behaviour might affect catch per unit effort (CPUE) and the resultant stock abundance estimates or population parameters. This review reveals that environment‐related variation in feeding behaviour can act through four different mechanisms: metabolic processes, sensory limitations, social interactions and direct impacts. Water temperature, light level, current velocity and ambient prey density are likely to have largest effects on fish catchability, potentially affecting variation in CPUE by a factor of ten. Feeding behaviour is also density‐dependent, with both positive and negative effects. Over time and geographic space a target species can occupy wide ranges of environmental conditions, and in certain cases, spatial and temporal variation in feeding biology could have a larger impact on CPUE than patterns of abundance. Temperature, light and current can be measured with relative facility and corrections to stock assessment models are feasible. Making corrections for biological variables such as prey density and bait competitors will be more difficult because the measurements are often not practical and relationships to feeding catchability are more complex and poorly understood. There is a critical need for greater understanding of how environmental variables affect feeding‐related performance of baited fishing gear. A combination of field observations and laboratory experiments will be necessary to parameterize stock assessment models that are improved to accommodate variation in fish behaviour. Otherwise, survey data could reveal more about variation in behaviour than abundance trends.
Individual identity and organisational control: Empowerment and Modernisation in a Primary Care Trust
Authors: McDonald Ruth
Published: December 2004

The notion of empowerment has been increasingly used within management discourses in recent years. Enthusiastic supporters conceive it as an acknowledgement of the individual employee as a talented, creative being, and hence a productive resource for contributing to organisational goals. Alternatively, more critical commentators have interpreted it as another means of exercising control over employees and their identities. Although various commentators have speculated on the management of identity as a means of organizational control, there is very little empirical work from which to draw conclusions. This paper, using participant observation and interview data, represents a contribution to the small body of empirical research in the area. It focuses on an initiative aimed ostensibly at ‘empowering’ staff in an English Primary Care Trust, which may be seen as an attempt at increasing organisational control by shaping employee identities. As such, these processes can be understood more readily in terms of ethics rather than empowerment. The term ethics is used here in a Foucauldian sense and is linked to the processes of self‐definition and self‐constraint by which individuals train themselves to become ethical persons. The paper suggests that the outcome of attempts to manufacture particular forms of subjectivity by such methods as ‘empowerment’ programmes may be very different from those intended.
The interactional management of patients’ physical incompetence: a conversation analytic study of physiotherapy interactions
Authors: Parry Ruth Helen
Published: December 2004

Patients’ physical incompetence is a feature of many clinical interactions; the challenges it presents are not only technical but also interactional. This paper examines how interpretations and interactional consequences of physical incompetence are dealt with during stroke physiotherapy. A conversation analytic approach was used to examine video‐recorded treatment sessions. Analysis demonstrated that managing physical incompetence forms an important element of the organisation of these interactions. Through their conduct, patients and therapists limit and counter its various negative implications, including those which attribute it to failure of a patient's efforts, co‐operation and personal competence, and failure of therapy. Understanding orientations to incompetence and their influence upon interactions provides some explanations, or ‘good reasons’, for certain features of clinical interactions that have attracted criticism. Analysis also shows how management of incompetence is grounded in the clinician's authority and contributes to its maintenance.

In the face of failures of physical competence, participants collaboratively and continually work to portray patients as deserving of treatment rather than sanction, and to convey that despite evident difficulties, the therapeutic process is a co‐operative and successful endeavour. The paper examines how these meanings are addressed and accomplished through interaction.
Understanding complex trajectories in health and social care provision
Authors: Allen Davina , Griffiths Lesley , Lyne Patricia
Published: December 2004

Ensuring collaboration between health and social care providers is a well‐established policy concern in most developed countries. Thus far, however, this has proved to be a frustratingly elusive goal. Despite the growing body of empirical work devoted to this issue, social scientific theorising on the management of complex caring trajectories remains under‐developed. This paper is an attempt to begin to address this gap in the literature. Drawing onStrausset al.'s (1985) writings on illness trajectories andElias's (1978) game model, we offer a framework – centred on the notion of a caring trajectory game – that can assist understanding of the linkages between individual trajectories of care and broader health and social care systems. It is only when we have developed a more theoretically sophisticated understanding of this relationship that we can begin to explain why trajectories of care take the course that they do. The framework arises from our analysis of eight ethnographic case studies of adults undergoing rehabilitation from a first acute stroke. In this paper we illustrate its utility by reference to one specific case: Edward.
Furosemide responsiveness, non‐adherence and resistance during the chronic treatment of heart failure: a longitudinal study
Authors: MacFadyen Robert J. , Gorski J. Christopher , Brater D. Craig , Struthers Allan D.
Published: December 2004

Background and methods

Loop diuretic therapy is an essential part of chronic systolic heart failure (CH)F management, yet response to treatment can be variable. We analysed diuretic responsiveness in 39 stable patients with CHF in the community over 2 years. We measured serum ACE as a marker of adherence to ACE inhibitor therapy and urinary furosemide as a marker of diuretic adherence and action. Patients’ clinical outcome was stable and not hospitalized (Group 0); alive but hospitalized (Group 1); or dead during follow up (Group 2).

Results

Prescribed furosemide dose was variable (range 20–370 mg generally once daily) and progressive dose increments were common. Failed furosemide adherence (defined as < 10% of a dose excreted in 24 h urine where normal average excretion = 50% of an oral dose) during static prescribed dosing was infrequent relative to all days of therapy; yet was equally common across all outcome groups. Furosemide non‐adherence appeared to be independent of non‐adherence with ACE inhibitor (as marked by serum ACE activity > 20 U l−1) treatment. Furosemide responsiveness (mm of sodium excreted per mg furosemide in urine) showed no relationship to prescribed dose and paradoxically tended to rise in patients with higher basal aldosterone concentrations. Furosemide responsiveness fell by outcome class despite increased dose. Within‐patient responsiveness remained relatively constant although highly variable between individuals.

Conclusions

Furosemide responsiveness varied greatly between individuals but was constant within an individual. Non‐adherence with furosemide was less common among those who died and appeared to occur at different time points from non‐adherence with ACE inhibitor treatment, which was slightly more common in all outcome groups. Patients who died were prescribed higher furosemide doses and had greater furosemide excretion yet had similar sodium excretion. The main factor in response to chronic furosemide therapy was intrarenal diuretic resistance. Gross non‐adherence was less important.
A comparison of three different sources of data in assessing the frequencies of adverse reactions to amiodarone
Authors: Loke Yoon K. , Derry Sheena , Aronson Jeffrey K.
Published: December 2004

Aims

To compare the frequencies of adverse drug reactions (ADRs) to amiodarone from three separate datasets: (i) a meta‐analysis of clinical trials, (ii) spontaneous reports published in medical journals, and (iii) spontaneous reports sent to the World Health Organization (WHO).

Methods

We classified the ADRs into eight categories, based on the site involved, and built a rank order of the ADRs by category (from most to least commonly reported) for each dataset. We also calculated the relative proportions for all eight ADR categories within each dataset, in order to be able to compare the distributions of ADR frequencies: we assigned an index value of 1.0 to the frequency of respiratory toxicity in each set and calculated values for the other ADRs relative to respiratory toxicity.

Results

Thyroid disorders were the most commonly reported ADRs in the WHO dataset. In contrast, published case reports showed a preponderance of respiratory disorders, while in the meta‐analysis cardiac conduction problems were the most frequent. The rank orders of ADRs differed among the three datasets, as did the index values of specific ADR categories with respect to the respiratory category.

Conclusions

The distributions of ADR rank order and relative frequencies are dissimilar among the three datasets, as each dataset compiles information in a different way. Nevertheless, each dataset has its own specific strengths, and all three should be used together in obtaining a complete picture of a drug's safety profile. Important therapeutic and regulatory decisions should not simply be based on one source of data.
Recommendations from Listening to Mothers: The First National U.S. Survey of Women's Childbearing Experiences
Authors:   Maternity Center Association
Published: December 2004

Abstract:  Listening to Mothers is the first national United States survey that explored women's attitudes, feelings, and knowledge about their maternity care and childbearing experiences. The report also systematically documented at the national level the frequency of many aspects of childbearing from prepregnancy care through postpartum physical and mental health outcomes. The results have increased understanding about many dimensions of childbearing in the United States and identified opportunities for improving the maternity experience in the country. The survey was a project of the Maternity Center Association in New York City, which also developed recommendations published in response to survey results. (BIRTH 31:1 March 2004)
Theophylline has no advantages over caffeine as a putative model drug for assessing CYP1A2 activity in humans
Authors: Rasmussen Birgitte Buur , Brøsen Kim
Published: December 2004

Aims The cytochrome P4501A2 (CYP1A2) catalyses the metabolism of a number of clinically used drugs, and thus there is an interest in determining the activity of CYP1A2 in patients before treatment with CYP1A2 substrates. Caffeine is the most commonly used model drug to assess CYP1A2 function, but due to the complex metabolism of caffeine, there is a need for an alternative drug to use as an index of CYP1A2 activity. In this study the CYP1A2 substrate theophylline was tested as a possible alternative to caffeine as a model drug for CYP1A2.

Methods Twelve healthy volunteers ingested 200 mg of caffeine, and the caffeine metabolic ratios (CMR), CMRurine=(AFMU+1MX+1MU)/17DMU and CMRplasma=17DMX/137TMX were determined 6 h after drug intake. After a period of about 2 months the volunteers ingested 257 mg theophylline and blood samples were drawn and urine was collected during the following 48 h. The oral and partial clearances of theophylline were calculated via N‐demethylation and 8‐hydroxylation. The theophylline metabolic ratios, 1MU/13DMX and 3MX/13DMX being evaluated as indices of CYP1A2 catalysed N‐demethylation and 13DMU/13DMX as an index of partly CYP1A2 catalysed 8‐hydroxylation, were estimated in 0–12 h, 0–24 h and 0–48 h urine samples, and in plasma and spot urine samples 6 h after the intake of theophylline.

Results The theophylline plasma ratios for the N‐demethylation pathways correlated with the oral clearance of theophylline (rs=0.881‐0.934, P<0.001) and with the respective formation clearances of the metabolites (rs=0.712‐0.925, P<0.05). Furthermore, all of the theophylline plasma ratios correlated with the caffeine plasma ratio (rs=0.645‐0.663, P<0.05). None of the caffeine metabolic ratios and none of the 6 h urinary theophylline ratios correlated with the oral or the partial clearances of theophylline (rs=0.042‐0.556, P >0.05). The theophylline 0‐12 h urine ratios correlated with the oral clearance of theophylline (rs=0.677‐0.757, P<0.05) and with the respective formation clearances of the metabolites (rs=0.705‐0.750, P<0.05). However, none of the theophylline urine ratios correlated with any of the caffeine metabolic ratios.

Conclusions In summary the theophylline 6 h plasma and 0–12 h urine ratios 1MU/13DMX and 3MX/13DMX, both reflecting N‐demethylation seem to be predictors of the CYP1A2 mediated metabolism of theophylline, whereas only the plasma ratio correlated with the caffeine plasma 17DMX/137TMX ratio. Thus, it would appear that the plasma theophylline N‐demethylation ratios are superior to the urine ratios as indices of CYP1A2 activity. However, because in some individuals the concentrations of theophylline metabolites in plasma were close to the limit of detection, it is concluded that theophylline does not have marked advantages over caffeine as a model drug for assessing CYP1A2 activity.
The haemodynamic effects of subcutaneous sumatriptan, a 5HT1‐receptor agonist
Authors: Hood Stuart , David Birnie  , Hillis Stewart
Published: December 2004

Aims Previous in vivo studies with sumatriptan, a 5HT1‐receptor agonist, have demonstrated vasopressor responses in the pulmonary and systemic arterial circulation. Pulmonary artery wedge pressure (PAWP) also increases after sumatriptan injection, raising the possibility of an additional venoconstrictive action or a negative inotropic effect. The mechanism for the rise in PAWP was investigated in the study.

Methods Ten patients undergoing diagnostic coronary arteriography underwent haemodynamic monitoring.

Results There was a significant rise (P<0.05) in systemic and pulmonary arterial pressure and total systemic and pulmonary vascular resistance. There was a similar rise (P<0.05) in PAWP and left ventricular end diastolic pressure (LVEDP). There was no change in cardiac output nor in peak rate of left ventricular pressure rise (dP/dt).

Conclusions The sumatriptan induced rise in PAWP and LVEDP appears consequent upon increased afterload although a negative inotropic effect cannot be excluded.