bluuebunny/crossref_metadata_2025_split huggingface dataset:
Wages and Contracting Out: Does the Law of One Price Hold?
Authors: Berlinski Samuel 
Published: February 2008

AbstractWe find that, conditioning on industry of assignment, cleaners and security guards who participate in activities organized by contract companies earn 15 and 17 per cent less, respectively, than workers in those activities organized in‐house. These estimates are hardly affected by the inclusion of a set of jointly statistically significant exogenous variables. We can expect that most of the productive traits that characterize a task are transferred to the contractor in the process of contracting out a cleaning or security task. Thus, our findings are hard to rationalize by a simple competitive labour market setting where the law of one price holds.
The Ethnographic Contribution to Understanding Co‐worker Relations
Authors: Hodson Randy 
Published: February 2008

AbstractRelations among co‐workers are becoming both more important and more complex in modern workplaces as authority over job decisions is shifted from supervisors to quasi‐independent teams. The author develops a model of co‐worker relations that recognizes these changes and evaluates this model using data content coded from the full population of published book‐length workplace ethnographies (N = 204). Confirmatory factor analysis techniques support the existence of three distinct aspects of co‐worker relations: cohesiveness, conflict and peer supervision. The most important determinants of co‐worker relations are employee involvement programmes and management behaviour. Returning to specific case studies allows a theoretical elaboration of how employee involvement and management behaviour condition co‐worker relations. The author concludes by noting the importance of intellectual exchanges between qualitative and quantitative methods for generating new advances in the study of work and employment relations.
Semiparametrically Efficient Inference Based on Signs and Ranks for Median-Restricted Models
Authors: Hallin Marc , Vermandele Catherine , Werker Bas J. M. 
Published: February 2008

SummarySince the pioneering work of Koenker and Bassett, median-restricted models have attracted considerable interest. Attention in these models, so far, has focused on least absolute deviation (auto-)regression quantile estimation and the corresponding sign tests. These methods use a pseudolikelihood that is based on a double-exponential reference density and enjoy quite attractive properties of root n consistency (for estimators) and distribution freeness (for tests). The paper extends these results to general, i.e. not necessarily double-exponential, reference densities. Using residual signs and ranks (not signed ranks) and a general reference density f, we construct estimators that remain root n consistent, irrespective of the true underlying density g (i.e. also for g /=f). However, instead of reaching semiparametric efficiency bounds under double-exponential g, they reach these bounds when g coincides with the chosen reference density f. Moreover, we show that choosing reference densities other than the double-exponential in applications can lead to sizable gains in efficiency. The particular case of median regression is treated in detail; extensions to general quantile regression, heteroscedastic errors and time series models are briefly described. The performance of the method is also assessed by simulation and illustrated on financial data.
α-Investing: a Procedure for Sequential Control of Expected False Discoveries
Authors: Foster Dean P. , Stine Robert A. 
Published: February 2008

Summaryα-investing is an adaptive sequential methodology that encompasses a large family of procedures for testing multiple hypotheses. All control mFDR, which is the ratio of the expected number of false rejections to the expected number of rejections. mFDR is a weaker criterion than the false discovery rate, which is the expected value of the ratio. We compensate for this weakness by showing that α-investing controls mFDR at every rejected hypothesis. α-investing resembles α-spending that is used in sequential trials, but it has a key difference. When a test rejects a null hypothesis, α-investing earns additional probability towards subsequent tests. α-investing hence allows us to incorporate domain knowledge into the testing procedure and to improve the power of the tests. In this way, α-investing enables the statistician to design a testing procedure for a specific problem while guaranteeing control of mFDR.
Sex Hormones and Sexual Desire
Authors: GILES JAMES 
Published: February 2008

ABSTRACTSome scholars attempt to explain sexual desire biologically by claiming that sex hormones play a necessary causal role in sexual desire. This can be claimed even if sexual desire is seen to be an experience. Yet the evidence for such biological essentialism is inadequate. With males the loss of sexual desire following hormonal changes can easily be explained in terms of social stigmas that are attached to the physiological situation. Concerning females, the relevance of sex hormones here is even more unclear. Although some women seem to have fluctuations in sexual desire during hormonal changes, other women do not. Even where there are such fluctuations these can be explained by responses to other physiological changes or the meanings that are attached to the situation. Research with non‐human primates supports this view of the non‐essential relation of sex hormones to sexual desire. A phenomenology of sex hormones is given that shows a possible non‐essential relation between sex hormones and sexual desire. Here hormone induced excitations in the genitals may or may not lead to sexual desire depending on the meaning they are given within awareness. This suggests that sexual desire has its origin in the meanings we give our biology and not in our biology itself.
Perturbation Analysis: A Simple Method for Filtering SNPs with Erroneous Genotyping in Genome‐Wide Association Studies
Authors: Teo Y. Y. , Small K. S. , Clark T. G. , Kwiatkowski D. P. 
Published: February 2008

SummaryWe introduce a simple and yet scientifically objective criterion for identifying SNPs with genotyping errors due to poor clustering. This yields a metric for assessing the stability of the assigned genotypes by evaluating the extent of discordance between the calls made with the unperturbed and perturbed intensities. The efficacy of the metric is evaluated by: (1) estimating the extent of over‐dispersion of the Hardy‐Weinberg equilibrium chi‐square test statistics; (2) an interim case‐control study, where we investigated the efficacy of the introduced metric and standard quality control filters in reducing the number of SNPs with evidence of phenotypic association which are attributed to genotyping errors; (3) investigating the call and concordance rates of SNPs identified by perturbation analysis which have been genotyped on both Affymetrix and Illumina platforms. Removing SNPs identified by the extent of discordance can reduce the degree of over‐dispersion of the HWE test statistic. Sensible use of perturbation analysis in an association study can correctly identify SNPs with problematic genotyping, reducing the number required for visual inspection. SNPs identified by perturbation analysis had lower call and concordance rates, and removal of these SNPs significantly improved the performance for the remaining SNPs.
Conflict, cheats and the persistence of symbioses
Authors: Douglas Angela E. 
Published: February 2008

SummaryMany symbioses are widespread, abundant, and evolutionarily persistent. This is despite unambiguous evidence for conflict between the partners and the existence of cheats that use benefits derived from their partners while providing reduced or no services in return. Evidence from a diversity of associations suggests that symbioses are robust to cheating in several ways. Some symbioses persist despite conflict and cheating because of the selective advantage of cost‐free interactions (also known as byproduct mutualistic interactions), which incur no conflict. There is also evidence for the suppression of cheating by sanctions imposed by partners in some symbioses, and vertical transmission has been shown experimentally to promote traits that enhance partner performance. It is argued that these processes contribute to the apparent rarity of evolutionary transitions from symbiosis to parasitism. There is strong phylogenetic evidence for the evolutionary reversion of various symbiotic organisms to free‐living lifestyles, but at least some of these transitions can be attributed to selection pressures other than within‐symbiosis conflict. The principal conclusion is that, although conflict is common in symbioses, it is generally managed and contained.ContentsSummary849I.Introduction850II.Conflict and cheats850III.Symbiotic interactions without cost852IV.Routes to conflict resolution854V.Discussion856Acknowledgements857References857
Postpartum perineal repair performed by midwives: a randomised trial comparing two suture techniques leaving the skin unsutured*
Authors: Kindberg S , Stehouwer M , Hvidman L , Henriksen TB 
Published: February 2008

Objective  To compare a continuous suture technique with interrupted stitches using inverted knots for postpartum perineal repair of second‐degree lacerations and episiotomies.Design  A double‐blind randomised controlled trial.Setting  A Danish university hospital with more than 4800 deliveries annually.Population  A total of 400 healthy primiparous women with a vaginal delivery at term.Method  Randomisation was computer‐controlled. Structured interviews and systematic assessment of perineal healing were performed by research midwives blinded to treatment allocation at 24–48 hours, 10 days and 6 months postpartum. Pain was evaluated using a visual analogue scale and the McGill Pain Questionnaire. Wound healing was evaluated using the REEDA scale and by assessment of gaping wounds >0.5 cm. Analysis complied with the intention‐to‐treat principle.Main outcome measures  The primary outcome was perineal pain 10 days after delivery. Secondary outcomes were wound healing, patient satisfaction, dyspareunia, need for resuturing, time elapsed during repair and amount of suture material used.Results  A total of 400 women were randomised; 5 women withdrew their consent, leaving 395 for follow up. The follow‐up rate was 98% for all assessments after delivery. No difference was seen in perineal pain 10 days after delivery. No difference was seen in wound healing, patient satisfaction, dyspareunia or need for resuturing. The continuous suture technique was significantly faster (15 versus 17 minutes, P = 0.03) and less suture material was used (one versus two packets, P < 0.01).Conclusion  Interrupted, inverted stitches for perineal repair leaving the skin unsutured appear to be equivalent to the continuous suture technique in relation to perineal pain, wound healing, patient satisfaction, dyspareunia and need for resuturing. The continuous technique, however, is faster and requires less suture material, thus leaving it the more cost‐effective of the two techniques evaluated.
Crocus sativus L. (saffron) in the treatment of premenstrual syndrome: a double‐blind, randomised and placebo‐controlled trial
Authors: Agha‐Hosseini M , Kashani L , Aleyaseen A , Ghoreishi A , Rahmanpour H , Zarrinara AR , Akhondzadeh S 
Published: February 2008

Objective  The aim of this double‐blind and placebo‐controlled trial was to investigate whether saffron (stigma of Crocus sativus L.) could relieve symptoms of premenstrual syndrome (PMS).Design  Double‐blind, randomised and placebo‐controlled trial.Setting  Departments of Gynaecology/Obstetrics and Psychiatry, Tehran and Zanjan University of Medical Sciences.Population  Women aged 20–45 years with regular menstrual cycles and experience of PMS symptoms for at least 6 months were eligible for the study.Method  Women were randomly assigned to receive capsule saffron 30 mg/day (15 mg twice a day; morning and evening) (group A) or capsule placebo (twice a day) for a two menstrual cycles (cycles 3 and 4).Main outcome measures  The primary outcome measure was the Daily Symptom Report, and secondary outcome measure was the Hamilton Depression Rating Scale.Results  In this trial, saffron was found to be effective in relieving symptoms of PMS. A significant difference was observed in efficacy of saffron in cycles 3 and 4 in the Total Premenstrual Daily Symptoms and Hamilton Depression Rating Scale.Conclusion  The results of this study indicate the efficacy of C. sativus L. in the treatment of PMS. However, a tolerable adverse effects profile of saffron may well confirm the application of saffron as an alternative treatment for PMS. These results deserved further investigations.
Insensitivity to glutamate neurotoxicity mediated by NMDA receptors in association with delayed mitochondrial membrane potential disruption in cultured rat cortical neurons
Authors: Kambe Yuki , Nakamichi Noritaka , Georgiev Danko D. , Nakamura Nobuhiro , Taniura Hideo , Yoneda Yukio 
Published: February 2008

AbstractWe have attempted to elucidate mechanisms underlying differential vulnerability to glutamate (Glu) using cultured neurons prepared from discrete structures of embryonic rat brains. Brief exposure to Glu led to a significant decrease in the mitochondrial activity in hippocampal neurons cultured for 9 or 12 days at 10 μM to 1 mM with an apoptosis‐like profile, without markedly affecting that in cortical neurons. Brief exposure to Glu also increased lactate dehydrogenase release along with a marked decrease in the number of cells immunoreactive for a neuronal marker protein in hippocampal, but not cortical, neurons. Similar insensitivity was seen to the cytotoxicity by NMDA, but not to that by tunicamycin, 2,4‐dinitrophenol, hydrogen peroxide or A23187, in cortical neurons. However, NMDA was more efficient in increasing intracellular free Ca2+levels in cortical neurons than in hippocampal neurons. Antagonists for neuroprotective metabotropic Glu receptors failed to significantly affect the insensitivity to Glu, while NMDA was more effective in disrupting mitochondrial membrane potentials in hippocampal than cortical neurons. These results suggest that cortical neurons would be insensitive to the apoptotic neurotoxicity mediated by NMDA receptors through a mechanism related to mitochondrial membrane potentials, rather than intracellular free Ca2+levels, in the rat brain.
Transport of multiple nicotinic acetylcholine receptors in the rat optic nerve: high densities of receptors containing α6 and β3 subunits
Authors: Cox Brandon C. , Marritt Andrea M. , Perry David C. , Kellar Kenneth J. 
Published: February 2008

AbstractNeuronal nicotinic acetylcholine receptors (nAChRs) are abundant in the rat retina and at least seven heteromeric subtypes have been detected. Axons of retinal ganglion cells form the optic nerve and innervate areas of the brain important for visual processing, including the lateral geniculate nucleus, the superior colliculus, and the pretectal nucleus. Development of eye‐specific layers in these projection areas are dependent upon retinal waves which are initially mediated by nAChRs [Felleret al.,Science272 (1996), 1182;Pennet al.,Science279 (1998), 2108;Bansalet al.,J. Neurosci.20 (2000), 7672]. Unilateral eye‐enucleation studies in the rat indicate that nAChRs are on the terminals of optic nerve axons, where they may mediate influences of acetylcholine on visual pathways. In this study, we use radioligand binding and immunoprecipitation with subunit‐selective antibodies to investigate the subunit composition of nAChRs in the rat optic nerve. We found multiple nAChR subtypes in the optic nerve, all of which contain the β2 subunit. Most of these receptors are mixed heteromeric subtypes, composed of at least three different subunits. Included among these subtypes is the highest percentage and density of α6‐ and β3‐containing nAChRs of any area of the rat CNS that has been reported.
Efficacy and Tolerability of Coadministration of Rizatriptan and Acetaminophen vs Rizatriptan or Acetaminophen Alone for Acute Migraine Treatment
Authors: Freitag Fred , Diamond Merle , Diamond Seymour , Janssen Imke , Rodgers Anthony , Skobieranda Franck 
Published: February 2008

Objective.—To evaluate the efficacy and tolerability of coadministration of rizatriptan and acetaminophen in the acute treatment of migraine.Background.—Rizatriptan is a selective 5‐HT1B/1Dagonist approved for the acute treatment of migraine. Acetaminophen has been studied for acute migraine treatment. In consideration of the prominent central and peripheral mechanisms in migraine, the use of “multi‐mechanism therapy” is gaining momentum in the treatment of acute migraine attacks.Study Design.—This was a randomized, double‐blind, placebo‐controlled trial conducted at 10 centers. Eligible patients with migraine according to International Headache Society criteria treated a single migraine attack of moderate or severe intensity within 4 h from pain onset. Patients were randomized into 1 of 4 groups (rizatriptan 10 mg + acetaminophen 1000 mg [RA], rizatriptan alone [R], acetaminophen alone [A], and placebo [P]). There were 3 co‐primary hypotheses tested sequentially for 2‐h pain relief: (1) RA would be superior to P; (2) if the first was fulfilled, RA would be superior to A; and (3) if the first 2 were fulfilled, RA would be superior to R.Results.—Of 173 patients who treated a migraine, 123 patients (71.5%) achieved pain relief within 2 h. RA (90%) was significantly better than P (46%) and A (70%), but only numerically better than R (77%) for 2‐h pain relief. No significant differences were seen between the active treatment groups in adverse events.Conclusion.—Rizatriptan coadministered with acetaminophen achieved 2 of the 3 primary hypotheses, proving superior to both acetaminophen and placebo for 2‐h pain relief, but failing to achieve superiority to rizatriptan alone. RA was as well tolerated as each of the individual agents.
Histamine‐N‐Methyl Transferase Polymorphism and Risk for Migraine
Authors: García‐Martín Elena , Martínez Carmen , Serrador Mercedes , Alonso‐Navarro Hortensia , Navacerrada Francisco , Agúndez José A.G. , Jiménez‐Jiménez Félix Javier 
Published: February 2008

Background/Objectives.— Histamine has been implicated in the pathogenesis of migraine. In the CNS, histamine is almost exclusively metabolized by the polymorphic enzyme histamine N‐methyltransferase (HNMT). The HNMT gene (chromosome 2q22.1), shows diverse single nucleotide polymorphisms. One of these, located in exon 4 C314T, causes the amino acid substitution Thr105Ile, related to decreased enzyme activity. The aim of this study was to investigate the possible association between HNMT polymorphism and the risk for migraine.Methods.— We studied the frequency of the HNMT genotypes and allelic variantes in 197 patients with migraine and 245 healthy controls using a PCR‐RLFP method.Results.— The frequencies of the HNMT genotypes and allelic variants did not differ significantly between migraine patients and controls, and were unrelated with the age of onset of migraine attacks, gender, personal history of allergic diseases, family history of migraine, or presence of aura.Conclusion.— The results of the present study suggest that HNMT polymorphism in not related with the risk for migraine.
CHANGES IN NUTRIENT CONTENT OFPALMARIA PALMATAIN RESPONSE TO VARIABLE LIGHT AND UPWELLING IN NORTHERN SPAIN1
Authors: Martínez Brezo , Rico Jose M. 
Published: February 2008

Light has been identified as one of the main factors affecting seaweed ecophysiology. We investigated the dependence of nutrient metabolism on sun and shade light conditions and whether episodes of upwelling of nutrient‐rich subsuperficial water could reduce the summer nutrient limitation driving physiological changes inPalmaria palmata(L.) Kuntze. We measured the major nutrient pools, photosynthetic pigments, and light curves, under sun and shade conditions during a summer period when one upwelling was recorded. The redundancy analysis (RDA) produced two clear groups: sun‐ and shade‐acclimated algae. Light was the major predictive factor. Sun‐acclimated algae exhibited higher carbon (C) and lower nitrogen (N) and phosphorus (P) content in association with the storage of floridoside (main C reserve) to benefit from higher irradiance (under nutrient limitation). Among N pools, N reserves (phycoerythrin, nitrate) were a lower proportion of the total N in sun‐acclimated algae, suggesting their degradation to fulfill the N demands of the cell. The orthophosphate content was also lower in sun‐acclimated algae, indicating its utilization as a nutrient reserve. In contrast, N within cell walls and membranes and chlacontributed to a similar proportion of the total N in sun‐ and shade‐acclimated algae, suggesting a response to sustain cell integrity. Transient high nutrient concentration due to the upwelling was unrelated to the nutrient content of the thallus. The storage of C as floridoside from high light exposure was shown to be the driving force for the metabolic adjustment ofP. palmataat the end of summer before the onset of dormancy.
Electrocardiographic Characteristics of the Variants of Idiopathic Left Ventricular Outflow Tract Ventricular Tachyarrhythmias
Authors: KUMAGAI KOJI , FUKUDA KOJI , WAKAYAMA YUJI , SUGAI YOSHINAO , HIROSE MASANORI , YAMAGUCHI NOBUHIRO , TAKASE KEI , YAMAUCHI YASUTERU , TAKAHASHI ATSUSHI , AONUMA KAZUTAKA , SHIMOKAWA HIROAKI 
Published: February 2008

Background: Despite similar QRS morphology, idiopathic repetitive monomorphic ventricular tachyarrhythmias (VTs) of left ventricular outflow tract (LVOT) are known to have the variants of different adjacent origins, including the aorto‐mitral continuity (AMC), anterior site around the mitral annulus (MA), aortic sinus cusps (ASC), and epicardium. However, the electrocardiographic characteristics of those variants previously have not been evaluated fully. Methods and Results: Based on the mapping site and successful ablation in 45 consecutive patients with LVOT‐VTs, we classified them into VTs of AMC (n = 3), MA (n = 8), ASC (n = 32), and epicardial (n = 2) origins. In all patients, we performed activation mapping and an electrocardiographic analysis. All AMC‐VTs patients had monophasic R waves in almost all the precordial leads, while those with anterior MA‐VTs had an Rs pattern in some precordial leads except for lead V6, and those with ASC‐VTs had a variable transitional zone in leads V1–4. There was no S wave in lead V6 in any group except for one patient with anterior MA‐VTs. The intrinsicoid deflection time in the AMC‐VTs patients and anterior MA‐VTs patients was significantly greater than in those with ASC‐VTs (P < 0.05). There was no significant difference in the R‐wave amplitude in the inferior leads among the groups. Successful radiofrequency catheter ablation (RFCA) was achieved in all patients except for in those with epicardial origin VT. Conclusions: Despite many morphological similarities, the LVOT‐VTs originating from the AMC, anterior MA and ASC could be identified by our proposed electrocardiographic characteristics in order to safely perform RFCA.