bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of average symbol error rate and optimal power allocation for two‐way opportunistic relaying with amplify‐and‐forward protocol
Authors: Zhi Hui , Jia Xiangdong , Yang Longxiang , Fu Haiyang
Published: May 2012

In this paper, we investigate the statistical characteristics of the equivalent end‐to‐end signal‐to‐noise ratios (SNRs), the average symbol error ratios (SERs), and the optimal power allocation (OPA) for two‐way amplify‐and‐forward opportunistic relaying (TWOR‐AF) systems. First, with strict mathematic manipulation, we obtain the closed‐form solutions to the PDF, CDF, and moment generating function of the end‐to‐end SNRs. Then, based on the obtained statistical results, we present the total average SER of the Non‐OPA TWOR‐AF systems by using the appropriate approximation, in which only the greater segment of the two terminal SERs is considered. Finally, by aiming at minimizing the total average SER and using the SNRs balancing condition at both transceivers, we study the OPA problem subject to a total transmission power constraint. The comparison analysis shows that, for the Non‐OPA TWOR‐AF systems, we can only evaluate exactly the greater segment of the two SERs of the received signals at two transceivers by using the derivations. However, for the OPA TWOR‐AF systems, with our derivations we can evaluate exactly not only each segment of the two terminal SERs but also the sum SER (exact total SER). Moreover, the simulations show the OPA TWOR‐AF systems outperform the Non‐OPA TWOR‐AF systems. Copyright © 2012 John Wiley & Sons, Ltd.
Deficits in trace fear conditioning induced by neonatal alcohol persist into adulthood in female rats
Authors: Schreiber William B. , Hunt Pamela S.
Published: May 2012

The developing hippocampus is particularly vulnerable to the toxic effects of alcohol, and behavioral deficits on hippocampus‐dependent tasks have been reported following neonatal alcohol exposure in rodents. Previously, we have found that trace fear conditioning (a hippocampus‐dependent learning task) is disrupted in rats exposed to alcohol during postnatal days (PD) 4–9, although delay fear conditioning is not. The present study indicates that this impairment in trace fear conditioning, previously only measured during adolescence, persists into adulthood but only in females. Animals were exposed to 5.0 g/kg/day alcohol on PD 4–9 and were trained on either PD 30 or 65. Alcohol exposure significantly impaired trace conditioning in both sexes at PD 30. In animals trained as adults, the deficit in trace was only observed in female subjects, suggesting that although males exhibit an age‐related recovery of function, alcohol‐induced trace conditioning deficits are more persistent in female Sprague–Dawley rats. © 2012 Wiley Periodicals, Inc. Dev Psychobiol 55: 352–360, 2013
Prevalence and co‐existence of active components of ‘legal highs’
Authors: Zuba Dariusz , Byrska Bogumiła
Published: May 2012

The results of a study performed on samples of ‘legal highs’ seized in head shops by law enforcement and health services in Poland between mid‐2008 and mid‐2011 are presented. In total, 449 preparations which differed in labelling, net masses, forms of distribution, etc., were analyzed. A variety of sophisticated analytical methods, including gas chromatography–mass spectrometry (GC‐MS), liquid chromatography‐quadropole time‐of‐flight mass spectrometry (LC‐QTOF‐MS), high performance liquid chromatography (HPLC), and nuclear magnetic resonance (NMR) were applied for component identification and quantification.

The most common ingredients of legal highs were (in descending order): MPDV, caffeine, butylone, TFMPP, lidocaine, 4‐MEC, mephedrone, pFPP, BZP, and MDPBP. The scatter of substances changed over time, and piperazines were often ousted by cathinones. Most of the preparations were composed of two or more ingredients. Cathinones and piperazines were mixed mainly within the chemical classes (77.6% and 56.1% of dual links, respectively), caffeine was mixed both with piperazines (24 products) and cathinones (22 products), whereas lidocaine only with the latter class (47 products). A great inconsistency in the qualitative and quantitative composition of products with identical labelling was shown in an example of Coco products seized after August 2010; we found 10 different single component or mixture preparations, and the content of individual ingredients varied from several to hundreds of mgs.

This paper summarizes potential dangers connected with the uncontrolled sale of psychoactive substances, and indicates important issues concerning the analysis of legal highs. Copyright © 2012 John Wiley & Sons, Ltd.
Standardless 1H NMR determination of pharmacologically active substances in dietary supplements and medicines that have been illegally traded over the Internet
Authors: Monakhova Yulia B , Kuballa Thomas , Löbell‐Behrends Sigrid , Maixner Sibylle , Kohl‐Himmelseher Matthias , Ruge Winfried , Lachenmeier Dirk W
Published: May 2012

Dietary supplements and medicines are widely marketed over the Internet. Such products may be counterfeited and lack some or all of the labelled ingredients, or, in the case of lifestyle supplements, illegally contain pharmacologically active substances, such as anorectic or androgenic compounds. The market control – especially in the case of customs seizures – is complex, as reference substances necessary for identification and calibration in traditional high performance liquid chromatography (HPLC) or gas chromatography–mass spectrometry (GC‐MS) analysis are often unavailable, or extremely expensive. In this study, we introduce a 400 MHz 1H NMR methodology, which allows identification and quantitative estimation even without such pure compound standards. The identification can be based on literature spectra, or if these data are unavailable, by applying computational NMR spectra prediction. For standardless NMR determination, simple peak‐area comparison of the target compound with the TSP reference was used. The applicability was demonstrated for a wide range of compounds, such as mesterolone, oxymetholone, sibutramine, monacolin K, vinpocetine, evodiamine, caffeine, kavain, and dehydroepiandrosterone. The average relative standard deviations were 5.0% for peak area comparison, and 3.3% for external calibration with standard substance. The method uncertainty is therefore higher in standardless determination, but acceptable for the purpose of proving the presence or absence of pharmacologically active substances. The limit of detection of 0.5–2 mg/kg is sufficient for the purpose. NMR is ideally suited to controlling dietary supplements or illegal medicines as it provides qualitative and at least semi‐quantitative information more rapidly (measurement time 20 min) than with any other currently available spectroscopic or chromatographic method. Copyright © 2012 John Wiley & Sons, Ltd.
Antagonistic activities of Rho and Rac GTPases underlie the transition from neural crest delamination to migration
Authors: Shoval Irit , Kalcheim Chaya
Published: May 2012

Background: Neural crest progenitors arise as epithelial cells and then undergo a transition into mesenchyme that generates motility. Previously, we showed that active Rho maintains crest cells in the epithelial conformation by keeping stress fibers and membrane‐bound N‐cadherin. Results: While Rho disappears from cell membranes upon delamination, active Rac1 becomes apparent in lamellipodia of mesenchymal cells. Loss of Rac1 function at trunk levels inhibited NC migration but did not prevent cell emigration that is associated with N‐cadherin downregulation and G1/S transition. Furthermore, inhibition of Rho stimulated premature Rac1 activity and consequent formation of lamellipodia, leading to NC migration. To examine whether timely migration influences cell fate, Rac1 activity was transiently inhibited to delay dispersion of early NC cells that generate neural derivatives, and its activity was restored by the time of melanoblast migration. Even if confronted with a melanocytic environment, late‐dispersing progenitors colonized sensory ganglia where they generated neurons and glia. Conclusions: In the context of crest delamination and migration, activities of Rho and Rac are differential, sequential, and antagonistic. Furthermore, transient inhibition of Rac1 that delays the onset of crest dispersion raises the possibility that the fate of trunk neural progenitors might be restricted prior to migration. Developmental Dynamics 241:1155–1168, 2012. © 2012 Wiley Periodicals, Inc.
Population genetic dynamics of three‐spined sticklebacks (Gasterosteus aculeatus) in anthropogenic altered habitats
Authors: Scharsack Joern P. , Schweyen Hannah , Schmidt Alexander M. , Dittmar Janine , Reusch Thorsten B.H. , Kurtz Joachim
Published: May 2012

In industrialized and/or agriculturally used landscapes, inhabiting species are exposed to a variety of anthropogenic changes in their environments. Genetic diversity may be reduced if populations encounter founder events, bottlenecks, or isolation. Conversely, genetic diversity may increase if populations adapt to changes in selective regimes in newly created habitats. With the present study, genetic variability of 918 sticklebacks from 43 samplings (21.3 ± 3.8 per sample) at 36 locations from cultivated landscapes in Northwest Germany was analyzed at nine neutral microsatellite loci. To test if differentiation is influenced by habitat alterations, sticklebacks were collected from ancient running waters and adjacent artificial stagnant waters, from brooks with salt water inflow of anthropogenic and natural origin and adjacent freshwater sites. Overall population structure was dominated by isolation by distance (IBD), which was significant across all populations, and analysis of molecular variance (AMOVA) revealed that 10.6% of the variation was explained by river catchment area. Populations in anthropogenic modified habitats deviated from the general IBD structure and in the AMOVA, grouping by habitat type running/stagnant water explained 4.9% of variation and 1.4% of the variation was explained by salt‐/freshwater habitat. Sticklebacks in salt‐polluted water systems seem to exhibit elevated migratory activity between fresh‐ and saltwater habitats, reducing IBD. In other situations, populations showed distinct signs of genetic isolation, which in some locations was attributed to mechanical migration barriers, but in others to potential anthropogenic induced bottleneck or founder effects. The present study shows that anthropogenic habitat alterations may have diverse effects on the population genetic structure of inhabiting species. Depending on the type of habitat change, increased genetic differentiation, diversification, or isolation are possible consequences.
Copper Complexes with a Hybrid Scorpionate Ligand Containing Pyridazine‐3‐thione
Authors: Nuss Gernot , Ozwirk Anja , Harum Bastian N. , Saischek Gerald , Belaj Ferdinand , Mösch‐Zanetti Nadia C.
Published: May 2012

A new scorpionate ligand, Na[HB(mim)2(PntBu)] (Na[PnBm]), with one pyridazinyl‐3‐thione and two methimazolyl (mim) substituents was prepared by mixing 6‐tert‐butylpyridazine‐3‐thione (HPntBu) and sodium dihydridobis(methimazolyl)borate (Na[Bm]) in boiling xylene. Addition of CuCl to a solution of Na[PnBm] in methanol in the presence of PR3 gave the monomeric copper(I) complexes [Cu{PnBm}(PR3)] (R = cyclohexyl 1, phenyl 2) in good yields. They were characterized by NMR spectroscopy and in the case of 2 also by single‐crystal X‐ray diffraction analysis. The latter revealed a compound in which the ligand is coordinated in a κ3‐S,S,H fashion, exhibiting a 3‐center‐2‐electron B–H···Cu interaction. Reaction of the ligand Na[PnBm] with CuCl in the absence of phosphane yielded a copper(I) complex, which was determined to be [Cu{PnBm}] (3). Variable‐temperature 1H NMR spectroscopy points to the occurrence of two dimeric isomers in solution, which interconvert in a fluxional behavior at room temperature. DFT calculations show that two isomers with a κ3‐Smim,Smim,H or a κ3‐Hmim,SPn,H coordination mode have very similar energies with a low energy barrier (25.4 kJ/mol) for their interconversion.
Acute and subacute oral toxicity of polychlorinated diphenyl sulfides in mice: Determining LD50 and assessing the status of hepatic oxidative stress
Authors: Zhang Xuesheng , Liu Fu , Chen Binyuan , Li Ying , Wang Zunyao
Published: May 2012

Polychlorinated diphenyl sulfides (PCDPSs), a series of dioxin-like compounds, have been detected in various environmental samples. However, information on the toxicity of these compounds is limited. In the present study, the toxic effects of PCDPSs were assessed after acute and subacute exposure in mice. Relationships between acute toxicity, number, and position of substituted Cl atoms were assessed. In the acute study, 11 types of PCDPSs were administered to female Kunming mice by gavage, and median lethal doses (LD50s) were determined by the Karber method. Results indicated that the LD50s of lower substituted PCDPSs were smaller than higher substituted PCDPSs. Substituted positions also influenced the LD50 of PCDPSs. Terminal necropsy showed increased relative liver weights and decreased relative kidney weights. Histological examination of livers demonstrated swollen cells, inflammation, vacuolization, and necrosis. In the 28-d subacute exposure tests, 11 types of PCDPSs were dissolved in corn oil and administered to mice at doses of 1, 10, and 100 mg/kg. Superoxide dismutase (SOD) activity and malondialdehyde (MDA) levels in mouse liver were determined after the exposure period. Results suggested that lower substituted PCDPSs decreased SOD activity in the high-dose groups compared with controls, and MDA level in the 100-mg/kg dose group was significantly increased. In addition, acute toxicity of PCDPSs partly corresponded to the hepatic oxidative damage observed. Environ. Toxicol. Chem. 2012; 31: 1485–1493. © 2012 SETAC
Network decomposition and multi‐path routing optimal control
Authors: Bruni Carlo , Priscoli Francesco Delli , Koch Giorgio , Pietrabissa Antonio , Pimpinella Laura
Published: May 2012

In this work we face the Routing problem defined as an optimal control problem, with control variables representing the percentages of each flow routed along the available paths (multi‐path routing), and a set of cost functions corresponding to the two different objectives of traffic balancing and bottleneck load minimization. A key issue considered in this paper is the possibility of splitting the given network in sub‐networks, each one controlled by a separate subset of variables. This of course designs a decomposition of the original control problem in a set of easier‐to‐be‐dealt‐with lower dimensional problems. Some simulation results validate the procedure. Copyright © 2012 John Wiley & Sons, Ltd.
Analytical performance evaluation of a class of receivers with joint equalisation and residual carrier frequency offset estimation
Authors: Pedrosa P. , Dinis R. , Nunes F.
Published: May 2012

In this paper, we consider a single‐carrier modulation combined with frequency‐domain equalisation block transmission with residual frequency errors. We employ a frequency‐domain iterative decision feedback equalisation (DFE) denoted iterative block‐decision feedback equalisation (IB‐DFE), which is combined with a decision‐directed carrier frequency offset (CFO) estimator. This estimator produces a CFO estimate within each iteration of the equaliser, which is used to compensate for the CFO. As the analytical study of the IB‐DFE is very hard because of the feedback chain, IB‐DFE receivers with joint symbol detection and carrier frequency synchronisation are also very difficult to tackle. To address this problem, we propose three new models. One models the decision‐directed CFO estimator, another models the IB‐DFE and finally one makes use of the previous two models to jointly characterise equalisation and carrier frequency synchronisation. In addition, a novel graphical tool for the convergence evaluation of the iterative receiver is included. Finally, we validate our models using Monte Carlo simulations and conclude that they are accurate for small and moderate residual CFO values. Copyright © 2012 John Wiley & Sons, Ltd.
XM: Association Testing on the X‐Chromosome in Case‐Control Samples With Related Individuals
Authors: Thornton Timothy , Zhang Qian , Cai Xiaochen , Ober Carole , McPeek Mary Sara
Published: May 2012

Genetic variants on the X‐chromosome could potentially play an important role in some complex traits. However, development of methods for detecting association with X‐linked markers has lagged behind that for autosomal markers. We propose methods for case‐control association testing with X‐chromosome markers in samples with related individuals. Our method, , appropriately adjusts for both correlation among relatives and male‐female allele copy number differences. Features of include: (1) it is applicable to and computationally feasible for completely general combinations of family and case‐control designs; (2) it allows for both unaffected controls and controls of unknown phenotype to be included in the same analysis; (3) it can incorporate phenotype information on relatives with missing genotype data; and (4) it adjusts for sex‐specific trait prevalence values. We propose two other tests, and , which can also be useful in certain contexts. We derive the best linear unbiased estimator of allele frequency, and its variance, for X‐linked markers. In simulation studies with related individuals, we demonstrate the power and validity of the proposed methods. We apply the methods to X‐chromosome association analysis of (1) asthma in a Hutterite sample and (2) alcohol dependence in the GAW 14 COGA data. In analysis (1), we demonstrate computational feasibility of and the applicability of our robust variance estimator. In analysis (2), we detect significant association, after Bonferroni correction, between alcohol dependence and single nucleotide polymorphism rs979606 in the monoamine oxidases A gene, where this gene has previously been found to be associated with substance abuse and antisocial behavior.
Famennian Fusulinina (Foraminifera) from the Holy Cross Mountains (central Poland)
Authors: Wójcik Krystian
Published: May 2012

Calcareous foraminifers representing 9 species and 5 genera were investigated in two Famennian sections located in the south‐western part of the Holy Cross Mountains (HCM), central Poland. They constitute redeposited material that, together with crinoids and calcareous algae, comprise the dominant component of limestone turbidite beds intercalated with deep‐marine marly sediments. The calcareous material was redeposited from an unknown carbonate platform located probably to the south of the HCM area. The first appearance data of foraminifers, mainly from the quasiendothyrid group, correlated to the Standard Conodont Zonation, indicate a diachronous appearance of the same species in different parts of Europe due to a migration delay from the foraminiferal evolutionary centre located in the south‐eastern shelves of Laurussia in the neighbouring areas. As a result, the Moravian foraminiferal zonation, where index taxa appeared in similar stratigraphic intervals, was chosen as the most applicable to the stratigraphy in the central Polish area. The Quasiendothyra communis–Eonodosaria evlanensis Interzone, the Quasiendothyra communis–Quasiendothyra regularis Zone and Quasiendothyra kobeitusana–Quasiendothyra konensis Zone were distinguished, respectively, in the HCM sections. Copyright © 2012 John Wiley & Sons, Ltd.
The role of territorial coverage and product diversification in the multinationality‐performance relationship
Authors: Oh Chang Hoon , Contractor Farok J.
Published: May 2012

This article introduces additional fine‐grained distinctions to the study of the multinationality‐performance relationship, such as territorial coverage and product diversification. It shows that the territorial scope covered by the firm makes a substantial difference to the relationship between multinationality and performance. In addition, the effect of multinationality on performance can sometimes be outweighed by product diversification. The path of international expansion is a much more complex process than is shown by existing studies. The results of this study suggest three generic strategies for international expansion with which an MNE can increase its performance. Copyright © 2012 Strategic Management Society.
The role of context in the multinationality‐performance relationship: A meta‐analytic review
Authors: Kirca Ahmet H. , Roth Kendall , Hult G. Tomas M. , Cavusgil S. Tamer
Published: May 2012

Using meta‐analytic data from 47,849 firms across 152 independent samples reported in 141 studies, this study presents a systematic investigation of the moderating effects of firm‐, industry‐, and country‐level factors on the multinationality‐performance relationship. The findings indicate that the effects of multinationality on performance depend on type of multinationality, firm strategic motivations, industry characteristics, and home country factors. Importantly, our assessment also reveals that firm size and stage of internationalization are not significant moderators. Thus, the findings indicate that the search for more complex M‐P relationships (i.e., U‐shaped, inverse U‐shaped, horizontal S‐curve) has the potential to expand our understanding, only when the characteristics of different research contexts, measurement issues, and firm characteristics are taken into account in the theoretical development and research design stages of studies. Copyright © 2012 Strategic Management Society.
The use of condition specific outcome measures in economic appraisal
Authors: Brazier John , Dixon Simon
Published: May 2012

Despite growing concern over the use of health utility measures in economic evaluations of health care programmes, economists have been reluctant to use the wealth of knowledge contained within studies using condition specific outcome measures (CSOMs). Problems with the measurement properties of many CSOMs means that the scope for their use in economic appraisal is extremely limited. This paper examines the potential uses of CSOMs in economics, namely: to provide valid descriptive material, to provide scales for comparing the effectiveness of interventions and to ‘validate’ the descriptive accuracy of economic measures of benefit. It is argued that valid descriptive information is essential for economic appraisal, no matter which method of evaluation is used. Generic measures have been criticised for being too narrow and insensitive to the consequences of specific conditions. CSOMs offer a rich source of information to produce quality adjusted life years (QALYs) but two potential methods, one of mapping health states from one scale to a QALY classification (such as Rosser), and the other, developing ‘exchange rates’ between scales are unsatisfactory. A more rigorous approach would necessitate a major research programme of revaluing existing CSOMs using preference based methods.

Another interesting avenue of research would be to use the information from CSOMs to construct health scenarios for valuation.

Given the current state of development of outcome measures, it seems advisable to use CSOMs alongside economic measures in trials. Such a strategy would help demonstrate the usefulness of economic measures to clinicians and to reconcile the two measures.
The changing distribution of a major surgical procedure across hospitals: Were supply shifts and disequilibrium important?
Authors: Friedman Bernard , Elixhauser Anne
Published: May 2012

This paper describes and analyzes the changing distribution across hospitals in the U.S. of total hip replacement surgery (THR) for the period 1980–1987. THR is one of the most costly single procedures contributing to health care expenses. Also, the use of THR exhibits a particularly high degree of geographic variation. Recent research pointed to shifts in demand as one plausible economic explanation for increasing use of THR. This paper questions whether shifts in supply may have been large enough to explain changes in patient mix and the relationship of patient mix to the number of procedures performed at a particular hospital. In addition, the relationship between total use of THR and the local availability of orthopaedic surgeons as well as the average allowable Medicare fee for standardized physician services is analyzed. These relationships might yield evidence to support a scenario of induced demand beyond the optimum for patients' welfare, or evidence of supply increase within a disequilibrium scenario.

This study, using data for all THR patients in a large sample of hospitals, tends to reject the formulation of a market with independent supply and demand shifts where the supply shifts were the dominant forces. Hospitals with a larger number of THRs performed did not see a higher percentage of older, sicker, and lower income patients. It was more likely that demand shifts generated increases in capacity for surgical services. Moreover, there was little evidence for a persistent disequilibrium and only weak evidence for inducement Also, we found little evidence that hospitals responded to financial incentives inherent in the Medicare payment system after 1983 to select among THR candidates in favour of those with below average expected cost We did observe increased concentration over time of THR procedures in facilities with high volume—suggesting plausible demand shifts towards hospitals with a priori quality and cost advantages or who obtained those advantages with a high volume of patients.
Demand for insurance by elderly persons: Private purchases and employer provision
Authors: Shea Dennis G. , Stewart R. Patrick
Published: May 2012

Studies of the demand for health insurance by elderly persons often inadequately address the distinctions between those who receive insurance through a former employer and those who purchase insurance on their own. The failure to distinguish these two modes of supplementing Medicare can lead to an inability to identify the effects of important independent variables. Using data from the Survey of Income and Program Participation this paper examines the demand for employer provided health insurance among retired pensioners using a bivariate probit model with partial observability and compares these results to other models of insurance demand among elderly persons.

The results indicate that unobserved factors reducing the probability of being offered employer provided insurance are associated with increased acceptance. A comparison of the employer provided results with results from other models of the demand for privately purchased insurance indicates that different independent variables may determine the probability of having these types of insurance. Previous studies of insurance that have not distinguished between these two types of insurance may not provide reliable estimates of the relationship between independent variables and the probability of insurance coverage.
Perspectives in health economics
Authors: Phelps Charles E.
Published: May 2012

This paper, originally presented at the Institut d'Etudes Politiques de Paris, October 12, 1993, provides a perspective on envisioned changes in the practice of health economics. Foreseen changes include: (1) Study of more homogeneous units of analysis; (2) More original data gathering; (3) Increased attention to uncertainty and the supply of and demand for information; (4) Increased attention to institutional structures and their effects on economic behaviour; (5) Expansion of relevant tools for studying economic issues in health care; and (6) Continuing breakdown of disciplinary barriers between health economics and other disciplines. Of these, the two overriding features will be increased emphasis on understanding the many roles of uncertainty in economic behaviour, institutions, and outcomes in health care, and in the use of more and more ‘micro’ data to study these issues.
Sensitivity analysis in economic evaluation: A review of published studies
Authors: Briggs Andrew , Sculpher Mark
Published: May 2012

A structured methodological review of journal articles published in 1992 was undertaken to determine whether recently published economic evaluation studies deal systematically and comprehensively with uncertainty. Ninety three journal articles were identified from a range of searches including a computerised search of the MEDLINE CD‐Rom database. Articles were reviewed to determine how they had handled uncertainty in: a) data sources; b) generalisability; c) extrapolation; and d) analytic method. Articles were subsequently assessed to determine how they had represented this uncertainty in terms of the overall results of their analysis. Finally, studies were rated on the basis of their overall performance with respect to dealing systematically and comprehensively with uncertainty.

Despite the numerous books and articles devoted to the appropriate methods to be employed by analysts conducting economic evaluation, 22 (24%) studies failed to consider uncertainty at all and 35 (38%) studies employed sensitivity analysis in a manner judged as inadequate. In all, 36 (39%) studies were judged to have given at least an adequate account of uncertainty with 13 (14%) of those judged to have provided a good account of uncertainty.

Such disappointing results may reflect a general lack of detail in much of the methods literature concerning how sensitivity analysis should be applied and how results should be presented. Journal editors and readers of economic evaluation articles should acquaint themselves with the methods for handling uncertainty in order that they can critically evaluate the extent to which authors have allowed for uncertainties inherent in their analysis.
Controlling for mental health in earnings equations: What do we gain and what do we lose?
Authors: Savoca Elizabeth
Published: May 2012

This paper examines the biases in estimating wage equations that may arise from measurement errors in various mental health indicators—two subjective proxies and one clinical assessment. The results suggest that a self‐reported measure based on whether the individual reported missing school or work for mental‐health‐related reasons leads to the smallest measurement error bias in the coefficients of the explanatory variables in an earnings equation. Two specific results lead to this conclusion. For one, the variance of the random component of its measurement error is the smallest among the three indicators leading to the least biased estimates of the impact of mental health on wages. Second, systematic reporting biases which vary with the non‐health regressors in a wage equation do not appear to exit in this measure. Consequently, this indicator follows the classical measurement error model. This implies that the coefficient estimates of the impact of non‐health variables are always improved, in the sense of having a smaller bias, when this mental health proxy is included in the regression.

The measurement error in a self‐evaluation according to the scale of excellent, good, fair, or poor has the largest variance thus leading to a substantial understatement of the impact of mental health on earnings. This measure also contains significant reporting biases that vary with gender, race, and education—many of the non‐health regressors in a wage equation.

The measurement error variance in the simulated diagnostic measure analyzed in this paper is also large. Thus this proxy will yield poor estimates of the impact of mental health on earnings.
Relative fees and the utilization of physicians' services in Canada
Authors: Hurley Jeremiah , Labelle Roberta
Published: May 2012

Study Question: The study objective is to estimate the relationship between changes in the relative fee physicians receive for a procedure and the utilization of the procedure.

Data Sources/Study Setting: The study uses claims‐based, procedure‐specific, quarterly, aggregate utilization data for physicians in three specialties and four provinces in Canada for the period 1977–1989.

Study Design: The unit of analysis is an individual procedure. Multi‐variate regression methods for cross‐sectional/times‐series data are applied to estimate the utilization‐fee relationship while controlling for supply‐ and demand‐side determinants of utilization.

Principal Findings: There is no evidence of a strong, uniform utilization response among the 11 procedures analyzed. The results include a mixture of significant and non‐significant fee coefficients, and among the significant coefficients, a mixture of signs is observed. The results are consistent with utility‐maximizing behaviour by physicians rather than with profit‐maximizing behaviour.

Conclusions: The fact that the direction and degree of the utilization effect associated with changing fees is procedure‐specific has direct implications for our ability to develop effective policies to modify physician behaviour that are based primarily on financial incentives, particularly those based on manipulating fees. The study also highlights the limitations of analyses based on aggregate data and suggests methodological approaches that have potential to overcome some of these limitations to fill gaps in our current knowledge.
Explaining the utilisation of dental care. Experiences from the finnish dental market
Authors: Sintonen Harri , Maljanen Timo
Published: May 2012

In this paper a model based on the theory of demand for health and of supplier inducement is developed to explain the utilisation of dental care. Of special interest are the effects of money price and various forms of inducement. It is also explored how the results are affected if different model specifications and estimation techniques are applied and what is the most appropriate one, when utilisation is measured by dental expenditure. The data come from a sample of 1779 employees, whose dental expenditure is refunded from 0 to 99.75%. Other things being equal, the methodological choices make a clear difference in parameter estimates. Only a log‐linear two‐part model and two‐part tobit with selectivity were suitable for explaining expenditure and produced quite similar results. Money price elasticity was small, but significant (–0.069). General and personal inducement appear to have a considerable effect on utilisation, but did not have any systematic connection with dentist/population ratio.
Primeval health economics in Britain: A personal retrospect of the pre‐HESG period
Authors: Williams Alan
Published: May 2012

There is a danger that the history of health economics in Britain comes to be regarded as roughly co‐terminous with the history of the Health Economists' Study Group (HESG). As one of the founders of that Group, I would take some pride from that, if it were true. But it is not. Just as primitive human societies existed before recorded history, so there was primeval health economics in Britain prior to 1972. There is probably more of this primeval health economics than even I know about, but as one of the ancient relics of that period I have been offered the opportunity to reminisce about what I saw during those dark ages! When one reaches the advanced age of 70, there is no escaping the fact that your past is bound to be more extensive (and probably more enjoyable) than your future, which is why the old enjoy looking back more than they enjoy looking forward! I am no exception. Hence this essay, which may either be seen as a rather self‐indulgent bout of nostalgia concerning the early days of health economics in Britain, or as an archaeological enterprise, exhibiting, for all to wonder at, the treasures to be found at carefully selected ancient (i.e., pre‐HESG) sites in Britain. Either way, my purpose is to suggest that most of the fundamental issues with which health economists have grappled in the last 25 years had already been identified and addressed in a careful way during the decade preceding the formation of the HESG.
US and UK health economics: Two disciplines separated by a common language?
Authors: Newhouse Joseph P.
Published: May 2012

Victor Fuchs recently conducted two survey questionnaires of American health economists, showing substantial consensus among them on positive questions and much less consensus on policy questions. I attempted to replicate Fuch's surveys for members of the HESG. I dropped some items that were specific to an American context and added some new questions. Overall there was less agreement on positive questions and more on policy questions than among the US economists. Alan Williams' 1985 article ‘Economics of Coronary Artery Bypass Grafting’ was deemed the most influential by a British author on health economics as a discipline and British health policy.
Acoustic Risk Management
Authors: Sinay Juraj , Balážiková Michaela
Published: May 2012

Modern civilization moves ahead with strong economical growth. Using a large number of new technologies and new machines in working procedures brings a proportional growth of noise and vibration. Noise and vibration have become an essential part of active safety measures because they are endangering the health of the employee as well as the public. Preventive solutions are ensured in new legislation and standards too. They facilitate high levels of unification of safety requirements for machines as well as the working environment from the acoustics point of view. © 2012 Wiley Periodicals, Inc.
Push/Pull Risk Factors at Workstations: A Case‐Control Study of Mexican Industrial Workers
Authors: Prado‐León Lilia R.
Published: May 2012

The objective of this study was to quantify and assess whether push/pull tasks in the workplace are risk factors for lower back pain etiology. A case‐control study was conducted of 231 industrial workers 18–55 years old who were insured by the Mexican Social Security Institute (MSSI) in the Guadalajara Metropolitan Area of Jalisco, Mexico. Exposure was evaluated via a questionnaire. Multivariate analysis using conditional logistic regression showed risks for push/pull tasks (odds ratio = 5.7, 95% confidence interval, 1.4–23.1) adjusted for lifting, carrying, and driving work. The fraction attributable to push/pull tasks was 0.58, suggesting that the risk of developing lumbar spondyloarthrosis might be reduced by 58% with ergonomic redesign for pushing and pulling tasks at workstations. Additional research is needed to confirm this relationship and will ideally incorporate a greater number of subjects to assure detailed analyses of exposure categories and facilitate new comparisons with the results of the present study. © 2012Wiley Periodicals, Inc.
Alternating predictive and short‐term memory modes of entorhinal grid cells
Authors: De Almeida Licurgo , Idiart Marco , Villavicencio Aline , Lisman John
Published: May 2012

Several lines of evidence indicate that the entorhinal cortex has memory functions, but such functions have not been previously found in grid cells, a cell type that provides major input to the hippocampus. We examined the firing of grid cells as rats crossed (runs) through grid cell vertices. We found that on some runs, firing tended to occur mostly inbound as the rat approached a vertex center while on other runs firing occurred mainly outbound. These results suggest that cells have a predictive mode (inbound firing) in which they represent a position ahead of the animal and a short term memory (STM) mode (outbound firing) in which they represent positions just passed through. Analysis of cell pairs showed that when vertex crossings were less than 1 second apart, the two cells tended to have the same mode. This indicates that modes are a network property. The tendency to have the same mode disappeared if crossings were separated by 2‐3 seconds, suggesting that modes alternate on the time scale of seconds. There was a small but statistically significant behavioral correlate of modes: velocity was slightly less in the STM mode. Both modes were organized by theta and gamma oscillations. The results suggest that the dual requirement for hippocampal storage and recall is met by rapidly alternating modes appropriate for predicting the future and storing the recent past. © 2012 Wiley Periodicals, Inc.
Peat deformation and biogenic gas bubbles control seasonal variations in peat hydraulic conductivity
Authors: Kettridge Nicholas , Kellner Erik , Price Jonathan S. , Waddington James M.
Published: May 2012

The hydraulic conductivity (K) of peat beneath the water table varies over short (annual) periods. Biogenic gas bubbles block pores and reduce K, and seasonal changes in the water table position cause peat deformation, altering peat pore size distribution. Although it has been hypothesized that both processes reduce K during warm dry summer conditions, temporal variations in K under field conditions have been explained previously by peat volume changes (strain) alone. We determine the effect of both controls on K by monitoring changes in gas content (Δγ), strain and K within a poor fen. Over the growing season, K decreased by an order of magnitude. In the near‐surface peat (0.3–0.7 m), this reduction is more strongly correlated with Δγ, providing the first field‐based evidence that biogenic gas bubbles reduce K. In the deeper peat (0.7–1.3 m), K is correlated principally with strain. However, causality is uncertain because of multicollinearity between strain and Δγ. To mitigate for multicollinearity, we took advantage of a peatland drainage experiment where the water table was artificially dropped at the beginning of the growing season, reducing correlations between strain and Δγ. Δγ remained the primary cause of K variations just beneath the water table at a depth of 0.5–0.7 m, although further down through the peat profile (0.7–1.2 m) changes in K were controlled by strain. We suggest that the larger pore structure of the poorly decomposed peat just below the water table is impacted less by volume changes than that of the more decomposed peat at depth. However, within this poorly decomposed peat, K is reduced by the high gas contents that result from higher rates of methane production. Copyright © 2012 John Wiley & Sons, Ltd.
Simulating effect of anthropogenic activities and climate variation on Liulin Springs discharge depletion by using the ARIMAX model
Authors: Hao Yonghong , Wu Jing , Sun Qingxia , Zhu Yuen , Liu Yan , Li Zhongtang , Yeh Tian‐Chyi J.
Published: May 2012

Based on the groundwater development process, and regional economic and social developing history, we divided the spring hydrological process of the Liulin Springs Basin into two periods: pre‐1973 and post‐1974. In the first period (i.e. 1957–1973), the spring discharge was affected by climate variation alone, and in the second period (i.e. 1974–2009), the spring discharge charge was influenced by both climate variation and human activities. A piecewise analysis strategy was used to differentiate the contribution of anthropogenic activities from climate variation on karst spring discharge depletion in the second period. Then, the ARIMAX model was applied to spring flow time series of the first period to develop a model for the effects of climate variation only. Using this model, we estimated the spring discharge in the second period solely under the influence of climate variation. Based on the water budget, we subtracted observed spring discharge from the estimated spring discharge and acquired the contribution of human activities on spring discharge depletion for the second period. The results of the analysis indicated that the contribution of climate variation to the spring discharge depletion is−0.20 m3/s from 1970s to 2000s. The contribution of anthropogenic activities to the spring flow depletion was −2.56 m3/s in 2000s, which was about 13 times more than that of climate variation. Our analysis further indicates that groundwater exploitation only accounts for 29% of the spring flow depletion due to the effects of human activities. The remaining 71% of the depletion is likely to be caused by other human activities, including dam building, dewatering during coal mining, and deforestation. Copyright © 2012 John Wiley & Sons, Ltd.
Benchmarking observational uncertainties for hydrology: rainfall, river discharge and water quality
Authors: McMillan Hilary , Krueger Tobias , Freer Jim
Published: May 2012

This review and commentary sets out the need for authoritative and concise information on the expected error distributions and magnitudes in observational data. We discuss the necessary components of a benchmark of dominant data uncertainties and the recent developments in hydrology which increase the need for such guidance. We initiate the creation of a catalogue of accessible information on characteristics of data uncertainty for the key hydrological variables of rainfall, river discharge and water quality (suspended solids, phosphorus and nitrogen). This includes demonstration of how uncertainties can be quantified, summarizing current knowledge and the standard quantitative results available. In particular, synthesis of results from multiple studies allows conclusions to be drawn on factors which control the magnitude of data uncertainty and hence improves provision of prior guidance on those uncertainties. Rainfall uncertainties were found to be driven by spatial scale, whereas river discharge uncertainty was dominated by flow condition and gauging method. Water quality variables presented a more complex picture with many component errors. For all variables, it was easy to find examples where relative error magnitudes exceeded 40%. We consider how data uncertainties impact on the interpretation of catchment dynamics, model regionalization and model evaluation. In closing the review, we make recommendations for future research priorities in quantifying data uncertainty and highlight the need for an improved ‘culture of engagement’ with observational uncertainties. Copyright © 2012 John Wiley & Sons, Ltd.
Carbon and suspended sediment transport in an impounded alpine river (Isère, France)
Authors: Némery Julien , Mano Vincent , Coynel Alexandra , Etcheber Henri , Moatar Florentina , Meybeck Michel , Belleudy Philippe , Poirel Alain
Published: May 2012

Carbon and total suspended sediment (TSS) loads were investigated from April 2006 to March 2008 in the mountainous watershed of the Isère River, French Alps (5570 km2). The river bed has been highly impounded for hydroelectricity production during the last century. Hydraulic flushes are managed every year to prevent TSS storage within upstream dams. The Isère River has been instrumented for high‐frequency monitoring of water, TSS by turbidity and carbon (organic, inorganic, dissolved and particulate) in order to evaluate the impact of natural floods and hydraulic flushes on annual loads. Annual TSS load which was estimated between 1.3 and 2.3 MT y−1 (i.e. 233 to 413 T km−2 y−1) highlighted the high erodibility of the Isère watershed. Annual carbon load was estimated between 173 103 T y−1 and 199 103 T y−1 (i.e 31 to 36 T km−2 y−1). About 80% of the annual carbon loads were inorganic. The impact of hydraulic flushes on annual loads appeared limited (less than 3% for annual TSS load and about 1.5% for annual carbon load), whereas the most important natural flood event contributed to 20% of the annual TSS load and 10% of the annual carbon load. Copyright © 2012 John Wiley & Sons, Ltd.
Adolescent Literacy: Looking Back and Moving Forward in the Global Flow
Authors: Bean Thomas , Dunkerly Judith
Published: May 2012

Awaiting abstract
New Times for Multimodality? Confronting the Accountability Culture
Authors: Siegel Marjorie
Published: May 2012

As new times become hard times, there may be little time for multimodality in school unless educators confront the accountability culture. This commentary reviews the arguments for multimodal transformations of school literacy curricula and explores the potential of reflective talk about multimodal meaning‐making as an assessment practice. Talking about how multimodality works may enable educators and students alike to talk back to an accountability culture that limits what counts as literacy.