bluuebunny/crossref_metadata_2025 huggingface dataset:
Urban and rural variations in morbidity and mortality in Northern Ireland
Authors: O'Reilly Gareth , O' Reilly Dermot , Rosato Michael , Connolly Sheelah
Published: June 2007

Background

From a public health perspective and for the appropriate allocation of resources it is important to understand the differences in health between areas. This paper examines the variations in morbidity and mortality between urban and rural areas.

Methods

This is a cohort study looking at morbidity levels of the population of Northern Ireland at the time of the 2001 census, and subsequent mortality over the following four years. Individual characteristics including demographic and socio-economic factors were as recorded on census forms. The urban-rural nature of residence was based on census areas (average population c1900) classified into eight settlement bands, ranging from cities to rural settlements with populations of less than 1000.

Results

The study shows that neither tenure nor car availability are unbiased measures of deprivation in the urban-rural context. There is no indication that social class is biased. There was an increasing gradient of poorer health from rural to urban areas, where mortality rates were about 22% (95% Confidence Intervals 19%–25%) higher than the most rural areas. Differences in death rates between rural and city areas were evident for most of the major causes of death but were greatest for respiratory disease and lung cancer. Conversely, death rates in the most rural areas were higher in children and adults aged less than 20.

Conclusion

Urban areas appear less healthy than the more rural areas and the association with respiratory disease and lung cancer suggests that pollution may be a factor. Rural areas however, have higher death rates amongst younger people, something which requires further research. There is also a need for additional indicators of deprivation that have equal meaning in urban and rural areas.
Influences on uptake of reproductive health services in Nsangi community of Uganda and their implications for cervical cancer screening
Authors: Mutyaba Twaha , Faxelid Elisabeth , Mirembe Florence , Weiderpass Elisabete
Published: June 2007

Background

Cervical cancer is the most common female cancer in Uganda. Over 80% of women diagnosed or referred with cervical cancer in Mulago national referral and teaching hospital have advanced disease. Plans are underway for systematic screening programmes based on visual inspection, as Pap smear screening is not feasible for this low resource country. Effectiveness of population screening programmes requires high uptake and for cervical cancer, minimal loss to follow up. Uganda has poor indicators of reproductive health (RH) services uptake; 10% postnatal care attendance, 23% contraceptive prevalence, and 38% skilled attendance at delivery. For antenatal attendance, attendance to one visit is 90%, but less than 50% for completion of care, i.e. three or more visits.

Methods

We conducted a qualitative study using eight focus group discussions with a total of 82 participants (16 men, 46 women and 20 health workers). We aimed to better understand factors that influence usage of available reproductive health care services and how they would relate to cervical cancer screening, as well as identify feasible interventions to improve cervical cancer screening uptake.

Results

Barriers identified after framework analysis included ignorance about cervical cancer, cultural constructs/beliefs about the illness, economic factors, domestic gender power relations, alternative authoritative sources of reproductive health knowledge, and unfriendly health care services. We discuss how these findings may inform future planned screening programmes in the Ugandan context.

Conclusion

Knowledge about cervical cancer among Ugandan women is very low. For an effective cervical cancer-screening programme, awareness about cervical cancer needs to be increased. Health planners need to note the power of the various authoritative sources of reproductive health knowledge such as paternal aunts (Sengas) and involve them in the awareness campaign. Cultural and economic issues dictate the perceived reluctance by men to participate in women's reproductive health issues; men in this community are, however, potential willing partners if appropriately informed. Health planners should address the loss of confidence in current health care units, as well as consider use of other cervical cancer screening delivery systems such as mobile clinics/camps.
Constitutive upregulation of the transforming growth factor-β pathway in rheumatoid arthritis synovial fibroblasts
Authors: Pohlers Dirk , Beyer Andreas , Koczan Dirk , Wilhelm Thomas , Thiesen Hans-Jürgen , Kinne Raimund W
Published: June 2007

Genome-wide gene expression was comparatively investigated in early-passage rheumatoid arthritis (RA) and osteoarthritis (OA) synovial fibroblasts (SFBs; n = 6 each) using oligonucleotide microarrays; mRNA/protein data were validated by quantitative PCR (qPCR) and western blotting and immunohistochemistry, respectively. Gene set enrichment analysis (GSEA) of the microarray data suggested constitutive upregulation of components of the transforming growth factor (TGF)-β pathway in RA SFBs, with 2 hits in the top 30 regulated pathways. The growth factor TGF-β1, its receptor TGFBR1, the TGF-β binding proteins LTBP1/2, the TGF-β-releasing thrombospondin 1 (THBS1), the negative effector SkiL, and the smad-associated molecule SARA were upregulated in RA SFBs compared to OA SFBs, whereas TGF-β2 was downregulated. Upregulation of TGF-β1 and THBS1 mRNA (both positively correlated with clinical markers of disease activity/severity) and downregulation of TGF-β2 mRNA in RA SFBs were confirmed by qPCR. TGFBR1 mRNA (only numerically upregulated in RA SFBs) and SkiL mRNA were not differentially expressed. At the protein level, TGF-β1 showed a slightly higher expression, and the signal-transducing TGFBR1 and the TGF-β-activating THBS1 a significantly higher expression in RA SFBs than in OA SFBs. Consistent with the upregulated TGF-β pathway in RA SFBs, stimulation with TGF-β1 resulted in a significantly enhanced expression of matrix-metalloproteinase (MMP)-11 mRNA and protein in RA SFBs, but not in OA SFBs. In conclusion, RA SFBs show broad, constitutive alterations of the TGF-β pathway. The abundance of TGF-β, in conjunction with an augmented mRNA and/or protein expression of TGF-β-releasing THBS1 and TGFBR1, suggests a pathogenetic role of TGF-β-induced effects on SFBs in RA, for example, the augmentation of MMP-mediated matrix degradation/remodeling.
Evolutionary history and functional implications of protein domains and their combinations in eukaryotes
Authors: Itoh Masumi , Nacher Jose C , Kuma Kei-ichi , Goto Susumu , Kanehisa Minoru
Published: June 2007

Background

In higher multicellular eukaryotes, complex protein domain combinations contribute to various cellular functions such as regulation of intercellular or intracellular signaling and interactions. To elucidate the characteristics and evolutionary mechanisms that underlie such domain combinations, it is essential to examine the different types of domains and their combinations among different groups of eukaryotes.

Results

We observed a large number of group-specific domain combinations in animals, especially in vertebrates. Examples include animal-specific combinations in tyrosine phosphorylation systems and vertebrate-specific combinations in complement and coagulation cascades. These systems apparently underwent extensive evolution in the ancestors of these groups. In extant animals, especially in vertebrates, animal-specific domains have greater connectivity than do other domains on average, and contribute to the varying number of combinations in each animal subgroup. In other groups, the connectivities of older domains were greater on average. To observe the global behavior of domain combinations during evolution, we traced the changes in domain combinations among animals and fungi in a network analysis. Our results indicate that there is a correlation between the differences in domain combinations among different phylogenetic groups and different global behaviors.

Conclusion

Rapid emergence of animal-specific domains was observed in animals, contributing to specific domain combinations and functional diversification, but no such trends were observed in other clades of eukaryotes. We therefore suggest that the strategy for achieving complex multicellular systems in animals differs from that of other eukaryotes.
Observing metabolic functions at the genome scale
Authors: Schwartz Jean-Marc , Gaugain Claire , Nacher Jose C , de Daruvar Antoine , Kanehisa Minoru
Published: June 2007

Background

High-throughput techniques have multiplied the amount and the types of available biological data, and for the first time achieving a global comprehension of the physiology of biological cells has become an achievable goal. This aim requires the integration of large amounts of heterogeneous data at different scales. It is notably necessary to extend the traditional focus on genomic data towards a truly functional focus, where the activity of cells is described in terms of actual metabolic processes performing the functions necessary for cells to live.

Results

In this work, we present a new approach for metabolic analysis that allows us to observe the transcriptional activity of metabolic functions at the genome scale. These functions are described in terms of elementary modes, which can be computed in a genome-scale model thanks to a modular approach. We exemplify this new perspective by presenting a detailed analysis of the transcriptional metabolic response of yeast cells to stress. The integration of elementary mode analysis with gene expression data allows us to identify a number of functionally induced or repressed metabolic processes in different stress conditions. The assembly of these elementary modes leads to the identification of specific metabolic backbones.

Conclusion

This study opens a new framework for the cell-scale analysis of metabolism, where transcriptional activity can be analyzed in terms of whole processes instead of individual genes. We furthermore show that the set of active elementary modes exhibits a highly uneven organization, where most of them conduct specialized tasks while a smaller proportion performs multi-task functions and dominates the general stress response.
Resisting the Power of Temptations
Authors: KNOCH DARIA , FEHR ERNST
Published: June 2007

Abstract:  Imagine you are overweight and you spot your favorite pastry in the storefront of a bakery. How do you manage to resist this temptation? Or to give other examples, how do you manage to restrain yourself from overspending or succumbing to sexual temptations? The present article summarizes two recent studies stressing the fundamental importance of inhibition in the process of decision making. Based on the results of these studies, we dare to claim that the capacity to resist temptation depends on the activity level of the right prefrontal cortex (PFC).
Adding Prediction Risk to the Theory of Reward Learning
Authors: PREUSCHOFF KERSTIN , BOSSAERTS PETER
Published: June 2007

Abstract:  This article analyzes
the simple Rescorla–Wagner learning rule from the vantage point of least squares learning theory. In particular, it suggests how measures of risk, such as prediction risk, can be used to adjust the learning constant in reinforcement learning. It argues that prediction risk is most effectively incorporated by scaling the prediction errors. This way, the learning rate needs adjusting only when the covariance between optimal predictions and past (scaled) prediction errors changes. Evidence is discussed that suggests that the dopaminergic system in the (human and nonhuman) primate brain encodes prediction risk, and that prediction errors are indeed scaled with prediction risk (adaptive encoding).
Mechanisms of Reinforcement Learning and Decision Making in the Primate Dorsolateral Prefrontal Cortex
Authors: LEE DAEYEOL , SEO HYOJUNG
Published: June 2007

Abstract:  To a first approximation, decision making is a process of optimization in which the decision maker tries to maximize the desirability of the outcomes resulting from chosen actions. Estimates of desirability are referred to as utilities or value functions, and they must be continually revised through experience according to the discrepancies between the predicted and obtained rewards. Reinforcement learning theory prescribes various algorithms for updating value functions and can parsimoniously account for the results of numerous behavioral, neurophysiological, and imaging studies in humans and other primates. In this article, we first discuss relative merits of various decision‐making tasks used in neurophysiological studies of decision making in nonhuman primates. We then focus on how reinforcement learning theory can shed new light on the function of the primate dorsolateral prefrontal cortex. Similar to the findings from other brain areas, such as cingulate cortex and basal ganglia, activity in the dorsolateral prefrontal cortex often signals the value of expected reward and actual outcome. Thus, the dorsolateral prefrontal cortex is likely to be a part of the broader network involved in adaptive decision making. In addition, reward‐related activity in the dorsolateral prefrontal cortex is influenced by the animal's choices and other contextual information, and therefore may provide a neural substrate by which the animals can flexibly modify their decision‐making strategies according to the demands of specific tasks.
Learning about Multiple Attributes of Reward in Pavlovian Conditioning
Authors: DELAMATER ANDREW R. , OAKESHOTT STEPHEN
Published: June 2007

Abstract:  The nature of the reward representation in Pavlovian conditioning has been of perennial interest to students of associative learning theory. We consider the view that it consists of a range of different attributes, each of which may be governed by different learning rules. We investigated this issue through a series of experiments using a time‐sensitive Pavlovian‐to‐instrumental transfer procedure, aiming to dissociate learning about temporal and specific sensory features of a reward. Our results successfully demonstrated that learning about these different features appears to be dissociable, with learning about the specific sensory features of a Pavlovian unconditioned stimulus (US) occurring very rapidly across a wide range of experimental procedures, while learning about the temporal features of the US occurred slightly less quickly and was more sensitive to parametric disruption. These results are discussed with regard to the potential independence or interdependence of the relevant learning processes, and to some recent neurophysiological recording and brain lesion work, which provide additional means to investigate these dissociations.
Calculating the Cost of Acting in Frontal Cortex
Authors: WALTON MARK E. , RUDEBECK PETER H. , BANNERMAN DAVID M. , RUSHWORTH MATTHEW F. S.
Published: June 2007

Abstract: To make informed and successful decisions, it is vital to be able to evaluate whether the expected benefits of a course of action make it worth tolerating the costs incurred to obtain them. The frontal lobe has been implicated in several aspects of goal‐directed action selection, social interaction, and optimal choice behavior. However, its exact contribution has remained elusive. Here, we discuss a series of studies in rats and primates examining the effect of discrete lesions on different aspects of cost‐benefit decision making. Rats with excitotoxic lesions of the anterior cingulate cortex became less willing to invest effort for reward but showed no change when having to tolerate delays. Orbitofrontal cortex‐lesioned rats, by contrast, became more impulsive, yet were just as prepared as normal animals to expend energy to obtain reward. The sulcal region of primate anterior cingulate cortex was also shown to be essential for dynamically integrating over time the recent history of choices and outcomes. Selecting a particular course of action may also come at the expense of gathering important information about other individuals. Evaluating social information when deciding whether to respond was demonstrated to be a function of the anterior cingulate gyrus. Taken together, this indicates that there may be dissociable pathways in the frontal lobe for managing different types of response cost and for gathering social information.
Integration of Cognitive and Motivational Information in the Primate Lateral Prefrontal Cortex
Authors: SAKAGAMI MASAMICHI , WATANABE MASATAKA
Published: June 2007

Abstract: The prefrontal cortex (PFC), particularly the lateral prefrontal cortex (LPFC), has an important role in cognitive information processing. The area receives projections from sensory association cortices and sends outputs to motor‐related areas. Neurons in LPFC code the behavioral significance of stimuli, which can be abstract precursors for complex motor commands and are structured hierarchically. Loss of these neurons leads to a lack of flexibility in decision making, such as seen in stereotyped behaviors. However, to make more appropriate decisions the code for behavioral significance has to reflect the subject's own desires and demands. Indeed, LPFC has connections with reward‐related areas, such as the orbitofrontal cortex (OFC), basal ganglia, and medial prefrontal cortex. Recently, many studies have reported reward modulation of neural codes of behavioral significance. Using an asymmetric reward paradigm, we can investigate the functional specificity of LPFC neurons that code both cognitive information and motivational information. In this review, we will discuss details of neuronal properties of LPFC neurons from the viewpoints of cognitive information processing and motivational information processing, and the question of how these two pieces of information are integrated. Abstract coding and contextual representations in the cognitive information processing are functional characteristics of LPFC. Such functional specificity in LPFC cognitive processes is supported by a long‐term scale of reward history in the motivational information processing. The integration enables us to make an elaborate decision with respect to goal‐directed behavior in complex circumstances.
Basal Ganglia Mechanisms of Reward‐Oriented Eye Movement
Authors: HIKOSAKA OKIHIDE
Published: June 2007

Abstract:  Expectation of reward facilitates motor behaviors that enable the animal to approach a location in space where the reward is expected. It is now known that the same expectation of reward profoundly modifies sensory, motor, and cognitive information processing in the brain. However, it is still unclear which brain regions are responsible for causing the reward‐approaching behavior. One candidate is the dorsal striatum where cortical and dopaminergic inputs converge. We tested this hypothesis by injecting dopamine antagonists into the caudate nucleus (CD) while the monkey was performing a saccade task with a position‐dependent asymmetric reward schedule. We previously had shown that: (1) serial GABAergic connections from the CD to the superior colliculus (SC) via the substantia nigra pars reticulata (SNr) exert powerful control over the initiation of saccadic eye movement and (2) these GABAergic neurons encode target position and are strongly influenced by expected reward, while dopaminergic neurons in the substantia nigra pars compacta (SNc) encode only reward‐related information. Before injections of dopamine antagonists the latencies of saccades to a given target were shorter when the saccades were followed by a large reward than when they were followed by a small reward. After injections of dopamine D1 receptor antagonist the reward‐dependent latency bias became smaller. This was due to an increase in saccade latency on large‐reward trials. After injections of D2 antagonist the latency bias became larger, largely due to an increase in saccade latency on small‐reward trials. These results indicate that: (1) dopamine‐dependent information processing in the CD is necessary for the reward‐dependent modulation of saccadic eye movement and (2) D1 and D2 receptors play differential roles depending on the positive and negative reward outcomes.
Plastic Corticostriatal Circuits for Action Learning
Authors: COSTA RUI M.
Published: June 2007

Abstract:  Reentrant corticobasal ganglia circuits are important for voluntary action and for action selection. In vivo and ex vivo studies show that these circuits can exhibit a plethora of short‐ and long‐lasting plastic changes. Convergent evidence at the molecular, cellular, and circuit levels indicates that corticostriatal circuits are involved in the acquisition and automatization of novel actions. There is strong evidence that activity in corticostriatal circuits changes during the learning of novel actions, but the plastic changes observed during the early stages of learning a novel action are different than those observed after extensive training. A variety of studies indicate that the neural mechanisms and the corticostriatal subcircuits involved in the initial acquisition of actions and skills differ from those involved in their automatization or in the formation of habits. Dopamine, a critical modulator of short‐ and long‐term plasticity in corticostriatal circuits, is differentially involved in early and late stages of action learning. Changes in dopaminergic transmission have several concomitant effects in corticostriatal function, which may be important for action selection and action learning. These diverse effects may subserve different roles for dopamine in reinforcement and action learning.
Multiple Representations of Belief States and Action Values in Corticobasal Ganglia Loops
Authors: SAMEJIMA KAZUYUKI , DOYA KENJI
Published: June 2007

Abstract:  Reward‐related neural activities have been found in a variety of cortical and subcortical areas by neurophysiological and neuroimaging experiments. Here we present a unified view on how three subloops of the corticobasal ganglia network are involved in reward prediction and action selection using different types of information. The motor/premotor‐posterior striatum loop is specialized for action‐based value representation and movement selection. The orbitofrontal–ventral striatum loop is specialized for object‐based value representation and target selection. The lateral prefrontal–anterior striatum loop is specialized for context‐based value representation and context estimation. Furthermore, the medial prefrontal cortex (MPFC) coordinates these multiple value representations and actions at different levels of hierarchy by monitoring the error in predictions.
Regional Changes in Hormone Therapy Use and Breast Cancer Incidence in California From 2001 to 2004
Authors: Robbins Anthony S. , Clarke Christina A.
Published: June 2007

Purpose

Recently, an unprecedented 1-year 7% decrease in the overall incidence of invasive female breast cancer in the United States was reported. It has been suggested that the decrease resulted from the mass cessation of estrogen-progestin hormone therapy (EPHT) in 2002. We took advantage of California's unique population-based cancer surveillance resources to assess whether regional changes in breast cancer incidence observed between 2001 and 2004 correlated with regional changes in EPHT use between 2001 and 2003.

Methods

We obtained statewide cancer registry and California Health Interview Survey (CHIS) EPHT data for almost 3 million non-Hispanic white women age 45 to 74 years, residing in California's 58 counties. We examined trends in the age-adjusted incidence of invasive female breast cancer and compared these with trends in the use of EPHT, after grouping all California counties into three groups based on EPHT use in 2001. We also examined CHIS data on trends in screening mammography.

Results

In 2001, there were large regional differences in EPHT use and breast cancer incidence. From 2001 to 2004, incidence declined by 8.8% in the counties with the smallest EPHT reductions, by 13.9% in those with intermediate reductions, and by 22.6% in counties with the largest EPHT reductions. Between 2001 and 2003, CHIS data did not show any significant change in the proportion of women who reported having a mammogram in the previous 2 years.

Conclusion

These data support the hypothesis that changes in EPHT use in 2002 may be responsible for significant declines in breast cancer incidence between 2002 and 2003 and sustained through 2004.
An analysis of the distribution of tension in a bar attached to a plate
Authors: Le Fevre E J , Mudge D R J , Dickie J F
Published: June 2007

This analysis relates to a bar of finite length attached to the surface of a semi-infinite flat plate, with the axis of the bar parallel to the surface of the plate. The bar projects beyond the edge of the plate and is subjected to tensile load. The object of this study is to determine an equation that describes approximately how the tension in the bar varies along the length over which it is attached to the plate. As a guide to the method of dealing with boundary conditions and discontinuities a simple case of two bars lap-jointed together is first considered.

Some improvements in the basic assumptions and methods used by previous investigators are incorporated and some results are shown that compare well with experimental results.
A statistical approach to micro-plastic strain in metals
Authors: Esin A , Jones W J D
Published: June 2007

The paper presents an outline of a theory of micro-inhomogeneity of stresses and strains resulting from the micro-structural properties of engineering materials. The problem is approached from a statistical point of view and it is experimentally shown that the degree of micro-inhomogeneity can be defined by normal distribution functions.

Using the experimental results a general concept is postulated which takes into account the physical reality as completely as is practicable. It is shown that the suggested approach can be used to take into account the micro-plastic strains which exist while the material is nominally within the elastic limit.
A contribution to the stress analysis of piston pins
Authors: Fessler H , Padgham H B
Published: June 2007

The frozen stress photoelastic technique was used to study the stresses in hollow cylinders supported on a central lug and loaded through two outer lugs, simulating the loading of a piston pin by the connecting rod and pision. The loading was arranged so that the resultant piston thrust acted through the (exaggerated) gaps between the lugs.

In addition to the surface stresses in the bore and on the outer surface of the pins, the distributions of orthogonal shear stresses on four (circular) cross-sections of one pin were determined and integrated to give the load transfer from the central lug into the pin. The orthogonal shear distribution in the gap was compared with Love's theoretical solution for the shear stresses in a thick walled tube.
Tradeoffs from Integrating Diagnosis and Treatment in Markets for Health Care
Authors: Afendulis Christopher C , Kessler Daniel P
Published: June 2007

To identify the important tradeoffs in consulting a single expert for both diagnosis and treatment, we examine the costs and health outcomes of elderly Medicare beneficiaries with coronary artery disease. We compare the empirical consequences of diagnosis by cardiologists who can provide surgical treatment – “integrated” cardiologists – to the consequences of diagnosis by a nonintegrated cardiologist. Diagnosis by an integrated cardiologist leads, on net, to higher health spending but similar health outcomes. The net effect contains three components: reduced spending and improved outcomes from better allocation of patients to surgical treatment options; increased spending conditional on treatment option; and worse outcomes from poorer provision of nonsurgical care. (JEL I11, I18)
ABCs (and Ds) of Understanding VARs
Authors: Fernández-Villaverde Jesús , Rubio-Ramírez Juan F , Sargent Thomas J , Watson Mark W
Published: June 2007

The dynamics of a linear (or linearized) dynamic stochastic economic model can be expressed in terms of matrices (A, B, C, D) that define a state space system for a vector of observables. An associated state space system (A, ^ B,C, ^D) determines a vector autoregression for those same observables. We present a simple condition for checking when these two state space systems match up and when they do not when there are equal numbers of economic and VAR shocks. We illustrate our condition with a permanent income example. (JEL C32, E32)
Shocks and Frictions in US Business Cycles: A Bayesian DSGE Approach
Authors: Smets Frank , Wouters Rafael
Published: June 2007

Using a Bayesian likelihood approach, we estimate a dynamic stochastic general equilibrium model for the US economy using seven macroeconomic time series. The model incorporates many types of real and nominal frictions and seven types of structural shocks. We show that this model is able to compete with Bayesian Vector Autoregression models in out-of-sample prediction. We investigate the relative empirical importance of the various frictions. Finally, using the estimated model, we address a number of key issues in business cycle analysis: What are the sources of business cycle fluctuations? Can the model explain the cross correlation between output and inflation? What are the effects of productivity on hours worked? What are the sources of the “Great Moderation”? (JEL D58, E23, E31, E32)
Valuing New Goods in a Model with Complementarity: Online Newspapers
Authors: Gentzkow Matthew
Published: June 2007

Many important economic questions hinge on the extent to which new goods either crowd out or complement consumption of existing products. Recent methods for studying new goods rule out complementarity by assumption, so their applicability to these questions has been limited. I develop a new model that relaxes this restriction, and use it to study competition between print and online newspapers. Using new micro data from Washington, DC, I estimate the relationship between the print and online papers in demand, the welfare impact of the online paper's introduction, and the expected impact of charging positive online prices. (JEL C25, L11, L82)
Estimating Risk Preferences from Deductible Choice
Authors: Cohen Alma , Einav Liran
Published: June 2007

We develop a structural econometric model to estimate risk preferences from data on deductible choices in auto insurance contracts. We account for adverse selection by modeling unobserved heterogeneity in both risk (claim rate) and risk aversion. We find large and skewed heterogeneity in risk attitudes. In addition, women are more risk averse than men, risk aversion exhibits a U-shape with respect to age, and proxies for income and wealth are positively associated with absolute risk aversion. Finally, unobserved heterogeneity in risk aversion is greater than that of risk, and, as we illustrate, has important implications for insurance pricing. (JEL D81, G22)
The Pluralism of Fairness Ideals: An Experimental Approach
Authors: Cappelen Alexander W , Hole Astri Drange , Sørensen Erik Ø , Tungodden Bertil
Published: June 2007

A core question in the contemporary debate on distributive justice is how to understand fairness in situations involving production. Important theories of distributive justice, such as strict egalitarianism, liberal egalitarianism, and libertarianism, provide different answers to this question. This paper presents the results from a dictator game where the distribution phase is preceded by a production phase. Each player's contribution is a result of a freely chosen investment level and an exogenously given rate of return. We estimate simultaneously the prevalence of three principles of distributive justice among the players and the distribution of the weight they attach to fairness. (JEL D63)
Signaling Character in Electoral Competition
Authors: Kartik Navin , McAfee R. Preston
Published: June 2007

We study a one-dimensional Hotelling-Downs model of electoral competition with the following innovation: a fraction of candidates have “character” and are exogenously committed to a campaign platform; this is unobservable to voters. Character is desirable, and a voter's utility is a convex combination of standard policy preferences and her assessment of a candidate's character. This structure induces a signaling game between strategic candidates and voters, since a policy platform affects voters' utilities not only directly, but also indirectly through inferences about a candidate's character. The model generates a number of predictions, starting with a failure of the median voter theorem. (JEL D72, D82)
Measuring Self-Control Problems
Authors: Ameriks John , Caplin Andrew , Leahy John , Tyler Tom
Published: June 2007

We develop a survey instrument to measure self-control problems in a sample of highly educated adults. This measure relates in the manner that theory predicts to liquid wealth accumulation and personality measures. Yet while self-control problems are typically seen as resulting in overconsumption and low wealth, we identify a significant group who underconsume and thereby accumulate high levels of wealth. In addition, self-control problems are smaller in scale for older than for younger respondents. Those who put money aside in retirement accounts may be delaying access to a point at which self-control problems are no longer important. (JEL D12, D14)
Regulation, Capital, and the Evolution of Organizational Form in US Life Insurance
Authors: Zanjani George
Published: June 2007

This paper studies the association between regulation and the organizational form of new life insurers between 1900 and 1949. The mutual form was popular in states with low initial capital requirements for mutual companies and differentially higher requirements for stock companies, but was rarely used elsewhere. This suggests that entrepreneurs took a “path of least resistance” when choosing organizational form and that the mutual's disadvantage in raising capital contributed to its decline–a decline that accelerated as states raised requirements and eliminated the aforementioned differentials. Contrary to previous analysis, the paper finds little evidence connecting other regulations to mutual decline. (JEL G21, L51, N21, N22)
Comparison of the effectiveness of commonly used clinic-based treatments for external genital warts
Authors: Sherrard Jackie , Riddell Lynn
Published: June 2007

We describe a prospective study designed to assess the effectiveness of the commonly used clinic-based treatments for genital warts individually and in combination. Patients presenting with new or recurrent genital warts were randomly allocated to one of five treatments on a weekly basis. The clinical endpoint was wart clearance or eight treatments, whichever occurred sooner. If there was not a good response by the eighth treatment, an alternate modality was offered. Four hundred and nine individuals were enrolled in the study. Almost no patients withdrew in any group due to adverse effects. Three-quarters of patients treated with podophyllin 25% and cryotherapy concurrently required only two treatments to clear their warts. All had clearance in less than eight treatments. Single therapy with either trichloracetic acid or podophyllin 25% resulted in longer time to wart clearance, and more persistent warts.
Three types of adherence to HIV antiretroviral therapy and their association with AIDS diagnosis, medication side-effects, beliefs about antiretroviral therapy, and beliefs about HIV disease
Authors: Schönnesson Lena Nilsson , Williams Mark L , Ross Michael W , Diamond Pamela M , Keel Blair
Published: June 2007

One hundred and ninety-three adults with HIV taking antiretroviral therapy completed a questionnaire on demographics, health beliefs, medication side-effects, and adherence to dose, schedule, and dietary instructions. Three health beliefs indices were identified: antiretroviral therapy (ART) benefits, ART adherence self-efficacy, and beliefs about future HIV-related health concerns. Patients who experienced medication side-effects reported strong beliefs that HIV infection would cause them future health problems or distrust in the benefits of ART. AIDS diagnosis obtained through medical records or medication side-effects were not related to any of the three types of adherence. Beliefs about future HIV-related health concerns were associated with suboptimal dose adherence. Beliefs about ART benefits were associated with suboptimal schedule and dietary instructions adherence. Older age and partner were protective factors of schedule adherence. Data suggest that health beliefs may vary across type of adherence and that adherence behaviours may be a coping strategy to adjust antiretroviral therapy to one's daily living.
Sexual and reproductive health in HIV-positive women: a dedicated clinic improves service
Authors: Coyne Katherine M , Hawkins F , Desmond N
Published: June 2007

We run a one-stop clinic for HIV-positive women, offering sexually transmitted infection screening, cervical cytology and family planning. We completed an audit cycle, and showed that all aspects of our care had improved since the introduction of this integrated service.
At greatest risk: pre- and early adolescent Bahamian youth experiencing anal intercourse
Authors: Yu S , Deveaux L , Lunn S , Liu H , Brathwaite N , Li X , Cottrell L , Marshall S , Stanton B
Published: June 2007

Although anal intercourse carries great risk for HIV transmission, little research has focused on it among the general population, particularly pre- and early adolescents. This study describes the prevalence of anal and vaginal intercourse among Bahamian pre- and early adolescents and associations with other risk behaviours, family interactions and intrapersonal correlates. Data were from 1274 sixth-grade students aged 9–14 years who completed self-administered questionnaires at baseline of a larger school-based behavioural intervention study. Youth who reported having had anal intercourse engaged in significantly higher rates of several risk behaviours and were significantly more likely to engage in risk behaviours over the next six months, compared with youth with a history of vaginal intercourse only, who in turn were more likely than virgin adolescents. Youth indulging in anal intercourse also perceived significantly lower levels of parental monitoring. Multivariate analyses revealed that anal intercourse, vaginal intercourse, reduced parental monitoring, depression and perceived friend high-risk involvement were associated with both past involvement and future intention to engage in other risk behaviours. Anal intercourse poses a direct threat to the health of these children and is a flag for a constellation of other risks.
Screening for rectal chlamydia infection in a genitourinary medicine clinic
Authors: Ivens D , MacDonald K , Bansi L , Nori A
Published: June 2007

Our department has been offering routine rectal chlamydia testing to all individuals reporting ano-receptive sex since 2002. We wanted to determine the prevalence of rectal chlamydia and if there were any factors associated with a positive diagnosis. A retrospective case-notes analysis was performed of all individuals tested for rectal chlamydia from November 2002 until March 2005. In total, 1187 case-notes were examined. Overall, the prevalence of chlamydia infection was 8.5%; in asymptomatic individuals, it was 5.1%. There was a positive association with chlamydia infection in patients who were HIV-positive, those who reported rectal symptoms and from samples in which microscopy of a rectal smear demonstrated >10 polymorphonuclear cells/high power field. The findings support our continuing to offer rectal chlamydia screening to patients attending our service. Chlamydia trachomatis infection should be considered as a possible diagnosis in patients who present with rectal symptoms outside a genitourinary medicine clinic setting.
Acute visual loss as a presenting manifestation of syphilis
Authors: Sivaram M , Radcliffe K W
Published: June 2007

A heterosexual man with acquired syphilis had an uncommon presentation in the form of acute visual loss. The unusual clinical presentation and a high cerebrospinal fluid lymphocyte count led to delayed diagnosis and treatment. Recognition of uncommon presentation of syphilis in the current epidemic is essential for the interruption of transmission.
HIV, cutaneous larva migrans and fever
Authors: Veraldi S , Persico M C
Published: June 2007

The authors describe two cases of cutaneous larva migrans associated with fever in two HIV-positive patients. Laboratory and instrumental examinations allowed to exclusion of other possible causes of fever. The presence of fever in patients with cutaneous larva migrans might represent a marker of HIV infection.
NRF IRES activity is mediated by RNA binding protein JKTBP1 and a 14-nt RNA element
Authors: Reboll Marc René , Oumard André , Gazdag Aniko Carla , Renger Isabelle , Ritter Birgit , Schwarzer Michael , Hauser Hansjoerg , Wood Monika , Yamada Michiyuki , Resch Klaus , Nourbakhsh Mahtab
Published: June 2007

The mRNA of human NF-κB repressing factor (NRF) contains a long 5′-untranslated region (UTR) that directs ribosomes to the downstream start codon by a cap-independent mechanism. Comparison of the nucleotide (nt) sequences of human and mouse NRF mRNAs reveals a high degree of identity throughout a fragment of 150 nt proximal to the start codon. Here, we show that this region constitutes a minimal internal ribosome entry segment (IRES) module. Enzymatic RNA structure analysis reveals a secondary structure model of the NRF IRES module. Point mutation analysis of the module determines a short, 14-nt RNA element (nt 640–653) as a mediator of IRES function. Purification of IRES binding cellular proteins and subsequent ESI/MS/MS sequence analysis led to identification of the RNA-binding protein, JKTBP1. EMSA experiments show that JKTBP1 binds upstream to the 14-nt RNA element in the NRF IRES module (nt 579–639). Over-expression of JKTBP1 significantly enhances activity of the NRF IRES module in dicistronic constructs. Moreover, siRNA experiments demonstrate that down-regulation of endogenous JKTBP1 decreases NRF IRES activity and the level of endogenous NRF protein. The data of this study show that JKTBP1 and the 14-nt element act independently to mediate NRF IRES activity.
Testing constraints on rRNA bases that make nonsequence-specific contacts with the codon•anticodon complex in the ribosomal A site
Authors: Taliaferro Dwayne L. , Farabaugh Philip J.
Published: June 2007

During protein synthesis, interactions between the decoding center of the ribosome and the codon·anticodon complexes maintain translation accuracy. Correct aminoacyl-tRNAs induce the ribosome to shift into a “closed” conformation that both blocks tRNA dissociation and accelerates the process of tRNA acceptance. As part of the ribosomal recognition of cognate tRNAs, the rRNA nucleotides G530 and A1492 form a hydrogen-bonded pair that interacts with the middle position of the codon·anticodon complex and recognizes correct Watson–Crick base pairs. Exchanging these two nucleotides (A530 and G1492) would not disrupt these interactions, suggesting that such a double mutant ribosome might properly recognize tRNAs and support viability. We find, however, that exchange mutants retain little ribosomal activity. We suggest that even though the exchanged nucleotides might function properly during tRNA recruitment, they might disrupt one or more other functions of the nucleotides during other stages of protein synthesis.
A conserved modified wobble nucleoside (mcm5s2U) in lysyl-tRNA is required for viability in yeast
Authors: Björk Glenn R. , Huang Bo , Persson Olof P. , Byström Anders S.
Published: June 2007

Transfer RNAs specific for Gln, Lys, and Glu from all organisms (exceptMycoplasma) and organelles have a 2-thiouridine derivative (xm5s2U) as wobble nucleoside. These tRNAs read the A- and G-ending codons in the split codon boxes His/Gln, Asn/Lys, and Asp/Glu. In eukaryotic cytoplasmic tRNAs the conserved constituent (xm5-) in position 5 of uridine is 5-methoxycarbonylmethyl (mcm5). A protein (Tuc1p) from yeast resembling the bacterial protein TtcA, which is required for the synthesis of 2-thiocytidine in position 32 of the tRNA, was shown instead to be required for the synthesis of 2-thiouridine in the wobble position (position 34). Apparently, an ancient member of the TtcA family has evolved to thiolate U34 in tRNAs of organisms from the domains Eukarya and Archaea. Deletion of theTUC1gene together with a deletion of theELP3gene, which results in the lack of the mcm5side chain, removes all modifications from the wobble uridine derivatives of the cytoplasmic tRNAs specific for Gln, Lys, and Glu, and is lethal to the cell. Since excess of the unmodified form of these three tRNAs rescued the double mutantelp3 tuc1, the primary function of mcm5s2U34 seems to be to improve the efficiency to read the cognate codons rather than to prevent mis-sense errors. Surprisingly, overexpression of the mcm5s2U-lacking tRNALysalone was sufficient to restore viability of the double mutant.
Offeree Silence and Contractual Agreement
Authors: Austen-Baker Richard
Published: June 2007

This article considers the mechanics of acceptance in the law of contract, focusing on the question of whether the silence of an offeree can effect acceptance. It finds the rule in Felthouse v Bindley (1862) alive and well, but creating problems for judges anxious to find agreements in place. The article considers whether there is, as sometimes suggested, a ‘duty to speak’ and dismisses this, along with any other supposed exceptions to the rule, concluding that silence cannot effect acceptance, but that conduct can do so unless an offeree ‘speaks' to contradict inevitable inferences from conduct. The article also argues that acceptance as such is not required for agreement, but rather the communication of apparent acceptance is the required element which, taken together with an offer, forms an agreement.
The Use and Abuse of the Doctrine of Vicarious Liability
Authors: McIvor Claire
Published: June 2007

Through an analysis of recent case law, this article seeks to highlight the flaws in the current English law approach to the doctrine of vicarious liability. Focusing on the new ‘close connection’ test for determining the ‘course of employment’ requirement, it argues that the recent expansion of employer's no-fault liability for the acts of employees has been founded upon a set of principles that are not only theoretically unsound, but also unjustifiable by reference to the normative background of the doctrine of vicarious liability. The article further argues that the judicial reasoning used in these cases indicates fundamental confusion about the nature of the distinction between direct and vicarious liability, and a particular lack of understanding about the concept of the non-delegable duty.
An Angel Named ‘The Bank’: The Bank's Fiduciary Duty as the Basic Theory in Israeli Banking Law
Authors: Plato-Shinar Ruth
Published: June 2007

The concept of imposing a fiduciary duty on banks is not originally an Israeli one. The Israeli courts adopted it from English principles of equity. However, from the moment it was introduced into Israeli law, the courts have expanded it far beyond its original equitable counterpart. This process of expansion has been performed in various ways: in terms of the content of the duty; in terms of the scope of the beneficiaries—other than customers—that are entitled to the duty; or in terms of the remedies granted in respect of breach thereof. As a result of this process, the Israeli concept of the banks' fiduciary duty has evolved over the years. From a narrowly applied duty, as in English common law, it became the basic theory in Israeli banking law. The article examines this interesting process from a critical point of view.