bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bias in Estimation of Misclassification Rates
Authors: Haberman Shelby J. 
Published: June 2006

When a simple random sample of size n is employed to establish a classification rule for prediction of a polytomous variable by an independent variable, the best achievable rate of misclassification is higher than the corresponding best achievable rate if the conditional probability distribution is known for the predicted variable given the independent variable. In typical cases, this increased misclassification rate due to sampling is remarkably small relative to other increases in expected measures of prediction accuracy due to samplings that are typically encountered in statistical analysis.This issue is particularly striking if a polytomous variable predicts a polytomous variable, for the excess misclassification rate due to estimation approaches 0 at an exponential rate as n increases. Even with a continuous real predictor and with simple nonparametric methods, it is typically not difficult to achieve an excess misclassification rate on the order of n−1. Although reduced excess error is normally desirable, it may reasonably be argued that, in the case of classification, the reduction in bias is related to a more fundamental lack of sensitivity of misclassification error to the quality of the prediction. This lack of sensitivity is not an issue if criteria based on probability prediction such as logarithmic penalty or least squares are employed, but the latter measures typically involve more substantial issues of bias. With polytomous predictors, excess expected errors due to sampling are typically of order n−1. For a continuous real predictor, the increase in expected error is typically of order n−2/3.
Loss of Information in Estimating Item Parameters in Incomplete Designs
Authors: Eggen Theo J. H. M. , Verhelst Norman D. 
Published: June 2006

In this paper, the efficiency of conditional maximum likelihood (CML) and marginal maximum likelihood (MML) estimation of the item parameters of the Rasch model in incomplete designs is investigated. The use of the concept of F-information (Eggen, 2000) is generalized to incomplete testing designs. The scaled determinant of the F-information matrix is used as a scalar measure of information contained in a set of item parameters. In this paper, the relation between the normalization of the Rasch model and this determinant is clarified. It is shown that comparing estimation methods with the defined information efficiency is independent of the chosen normalization. The generalization of the method to other models than the Rasch model is discussed.In examples, information comparisons are conducted. It is found that for both CML and MML some information is lost in all incomplete designs compared to complete designs. A general result is that with increasing test booklet length the efficiency of an incomplete design, compared to a complete design, is increasing, as is the efficiency of CML compared to MML. The main difference between CML and MML is seen in the effect of the length of the test booklet. It will be demonstrated that with very small booklets, there is a substantial loss in information (about 35%) with CML estimation, while this loss is only about 10% in MML estimation. However, with increasing test length, the differences between CML and MML quickly disappear.
The psychosocial inventory of ego strengths: Examination of theory and psychometric properties
Authors: Markstrom Carol A. , Marshall Sheila K. 
Published: June 2006

AbstractThe psychosocial inventory of ego strengths (PIES) was devised as a measure of Erikson's eight ego strengths. The present investigation extended previous research through examination of the validity and reliability of the PIES among 502 high school students. The study also included an appraisal of Erikson's ego strengths as indices of psychosocial well‐being. Reliability of the subscales of the PIES was shown through acceptable Cronbach's alphas. As expected, higher scores on ego strengths were positively correlated with psychosocial indictors of identity achievement, self‐esteem, locus of control, empathic concern, perspective‐taking, and positive forms of coping. Lower scores on ego strengths were related to less desirable psychosocial constructs. Biological sex and age differences also are reported. Based on the findings, the study offers validation of psychosocial theory. As well, the PIES is recommended for use among high school students.
Evolution in the strategic manufacturing planning process of organizations
Authors: Papke‐Shields Karen E. , Malhotra Manoj K. , Grover Varun 
Published: June 2006

AbstractThis study examines how strategic manufacturing planning processes vary systematically with respect to planning characteristics, and how the planning process appears to evolve over time. Through an empirical evaluation of over 200 U.S. manufacturers, we document the existence of four strategic manufacturing planning groups. These groups vary with respect to the degrees of “rationality” and “adaptability” of planning. In addition, the strategic manufacturing planning history and level of planning maturity differs between these groups, providing evidence that the planning process changes and evolves over time from “non‐rational adaptive” mode towards a more “rational adaptive” approach. Firms between these polar extremes appear to take different paths in their movement toward a “rational adaptive” mode, with some “focusing on rationality” first and others “focusing on adaptability” first. We also show that irrespective of the firm's environment, a greater degree of “rational adaptivity” is correlated with better planning outcomes and business performance. As such, it represents a “best practice” approach to strategic manufacturing planning. Insights created by this work not only make an important contribution to the manufacturing strategy literature, but can also be used by senior manufacturing managers to facilitate their progress towards more effective planning.
MDMA‐induced neurotoxicity: long‐term effects on 5‐HT biosynthesis and the influence of ambient temperature
Authors: O'shea Esther , Orio Laura , Escobedo Isabel , Sanchez Veronica , Camarero Jorge , Green Alfred Richard , Colado Maria Isabel 
Published: June 2006

3,4‐Methylenedioxymethamphetamine (MDMA or ‘ecstasy’) decreases the 5‐HT concentration, [3H]‐paroxetine binding and tryptophan hydroxylase activity in rat forebrain, which has been interpreted as indicating 5‐HT neurodegeneration. This has been questioned, particularly the 5‐HT loss, as MDMA can also inhibit tryptophan hydroxylase. We have now evaluated the validity of these parameters as a reflection of neurotoxicity.
Male DA rats were administered MDMA (12.5 mg kg−1, i.p.) and killed up to 32 weeks later. 5‐HT content and [3H]‐paroxetine binding were measured in the cortex, hippocampus and striatum. Parallel groups of treated animals were administered NSD‐1015 for determination of in vivo tryptophan hydroxylase activity and 5‐HT turnover rate constant.
Tissue 5‐HT content and [3H]‐paroxetine binding were reduced in the cortex (26–53%) and hippocampus (25–74%) at all time points (1, 2, 4, 8 and 32 weeks). Hydroxylase activity was similarly reduced up to 8 weeks, but had recovered at 32 weeks. The striatal 5‐HT concentration and [3H]‐paroxetine binding recovered by week 4 and hydroxylase activity after week 1. In all regions, the reduction in 5‐HT concentration did not result in an altered 5‐HT synthesis rate constant.
Administering MDMA to animals when housed at 4°C prevented the reduction in [3H]‐paroxetine binding and hydroxylase activity observed in rats housed at 22°C, but not the reduction in 5‐HT concentration.
These data indicate that MDMA produces long‐term damage to serotoninergic neurones, but this does not produce a compensatory increase in 5‐HT synthesis in remaining terminals. It also highlights the fact that measurement of tissue 5‐HT concentration may overestimate neurotoxic damage.

British Journal of Pharmacology (2006) 148, 778–785. doi:10.1038/sj.bjp.0706783
Investigation into the role of P2X3/P2X2/3 receptors in neuropathic pain following chronic constriction injury in the rat: an electrophysiological study
Authors: Sharp Caroline J , Reeve Alison J , Collins Sue D , Martindale Jo C , Summerfield Scott G , Sargent Becky S , Bate Simon T , Chessell Iain P 
Published: June 2006

Two P2X3/P2X2/3 receptor antagonists with different potencies were profiled electrophysiologically in a rat model of nerve injury.
A‐317491 has poor CNS penetrance (blood : brain, 1 : <0.05), and was therefore administered intravenously in chronic constriction injury (CCI)‐ and sham‐operated rats to study the involvement of P2X3 subunit‐containing receptors in the periphery in neuropathic pain. A‐317491 and Compound A were administered topically to the spinal cord to investigate the central contribution.
There were no significant inhibitory effects of A‐317491 intravenous (i.v.) seen in sham‐operated animals compared to vehicle controls. In CCI‐operated animals, there were significant inhibitory effects of 3 mg kg−1 A‐317491 i.v. on C fibre‐evoked responses, and with 10 mg kg−1 A‐317491 i.v. on Aδ and C fibre‐evoked responses. No significant effects of A‐317491 were observed after topical application to the spinal cord. In contrast, when Compound A was administered spinally in CCI animals, there was a decrease in Aδ and C fibre‐evoked responses, and wind up.
These changes indicate that A‐317491 has a selective effect on neuronal responses in CCI animals compared to sham, demonstrating an increased involvement of P2X3/P2X2/3 receptors in sensory signalling following nerve injury. In addition, the more potent antagonist Compound A was effective spinally, unmasking a potential central role of P2X3/P2X2/3 receptors at this site post nerve injury. These data support a role for P2X3/P2X2/3 antagonists in the modulation of neuropathic pain.

British Journal of Pharmacology (2006) 148, 845–852. doi:10.1038/sj.bjp.0706790
NO‐independent activation of soluble guanylate cyclase prevents disease progression in rats with 5/6 nephrectomy
Authors: Kalk Philipp , Godes Michael , Relle Katharina , Rothkegel Christiane , Hucke Andreas , Stasch Johannes‐Peter , Hocher Berthold 
Published: June 2006

Chronic renal disease is associated with oxidative stress, reduced nitric oxide (NO) availability and soluble guanylate cyclase (sGC) dysfunction. Recently, we discovered BAY 58‐2667, a compound activating heme‐deficient or oxidized sGC in a NO‐independent manner.
We assessed potential of BAY 58‐2667 in preventing cardiac and renal target organ damage in rats with 5/6 nephrectomy.
Male Wistar rats were allocated to three groups: 5/6 nephrectomy, 5/6 nephrectomy treated with BAY 58‐2667 and sham operation. Study period was 18 weeks: blood pressure and creatinine clearance were assessed repeatedly. At study end blood samples were taken and hearts and kidneys harvested for histological studies.
BAY 58‐2667 markedly lowered blood pressure in animals with 5/6 nephrectomy (untreated versus treated animals: 189±14 versus 146±11 mmHg, P<0.001). Left ventricular weight, cardiac myocyte diameter as well as cardiac arterial wall thickness significantly decreased in comparison to untreated animals with 5/6 nephrectomy. Natriuretic peptide plasma levels were also improved by BAY 58‐2667. Kidney function and morphology as assessed by creatinine clearance, glomerulosclerosis, interstitial and perivascular fibrosis of intrarenal arteries were likewise significantly improved by BAY 58‐2667.
This is the first study showing that BAY 58‐2667 effectively lowers blood pressure, reduces left ventricular hypertrophy and slows renal disease progression in rats with 5/6 nephrectomy by targeting mainly oxidized sGC. Therefore, BAY 58‐2667 represents a novel pharmacological principle with potential clinical value in treatment of chronic renal disease.

British Journal of Pharmacology (2006) 148, 853–859. doi:10.1038/sj.bjp.0706792
NO donors inhibit Na,K‐ATPase activity by a protein kinase G‐dependent mechanism in the nonpigmented ciliary epithelium of the porcine eye
Authors: Shahidullah Mohammad , Delamere Nicholas A 
Published: June 2006

We developed a novel method to isolate nonpigmented epithelial (NPE) cells from porcine eyes in order to examine Na,K‐ATPase responses to nitric oxide (NO) donors specifically in the epithelium.
Cells were treated with NO donors and other test compounds for 20 min prior to Na,K‐ATPase activity measurement.
NO donors, sodium nitroprusside (SNP, 1 μM–1 mM), sodium azide (100 nM–1 μM) and S‐nitroso‐N‐acetylpenicillamine (1 μM–1 mM) caused significant concentration‐dependent inhibition of Na, K‐ATPase activity. Detection of nitrite in the medium of L‐arginine and SNP‐treated NPE confirmed NO generation.
Concentration‐dependent inhibition of Na,K‐ATPase was also obtained by L‐arginine (1–3 mM), a physiological precursor of NO and 8p‐CPT‐cGMP (1–100 μM), a cell permeable analog of cGMP. The L‐arginine effect was abolished when the NO synthesizing enzyme, NO‐synthase, was inhibited by L‐NAME (100 μM).
The inhibitory effect of SNP or sodium azide on Na,K‐ATPase activity was suppressed by soluble guanylate cyclase (sGC) inhibitors, ODQ (10 μM) or methylene blue (10 μM).
The inhibitory effect of 8p‐CPT‐cGMP on Na,K‐ATPase was abolished by protein kinase G (PKG) inhibitors, H‐8 (1 μM) and H‐9 (20 μM), but not by the protein kinase A (PKA) inhibitor H‐89 (100 nM). H‐8 and H‐9 partially suppressed the inhibitory effect of SNP on Na,K‐ATPase.
Taken together the results indicate that Na,K‐ATPase inhibition response to NO donors involves activation of sGC, generation of cGMP and activation of PKG. These findings suggest that Na, K‐ATPase inhibition in NPE may contribute to the ability of NO donors to reduce aqueous humor secretion.

British Journal of Pharmacology (2006) 148, 871–880. doi:10.1038/sj.bjp.0706795
AM404, an inhibitor of anandamide uptake, prevents pain behaviour and modulates cytokine and apoptotic pathways in a rat model of neuropathic pain
Authors: Costa Barbara , Siniscalco Dario , Trovato Anna Elisa , Comelli Francesca , Sotgiu Maria Luisa , Colleoni Mariapia , Maione Sabatino , Rossi Francesco , Giagnoni Gabriella 
Published: June 2006

An attractive alternative to the use of direct agonists at the cannabinoid receptor type 1 (CB1) in the control of neuropathic pain may be to potentiate the actions of endogenous cannabinoids. Thus, the effects of AM404, an inhibitor of anandamide uptake, were assessed in an experimental model of neuropathic pain in rats.Daily treatment with AM404 prevented, time‐ and dose‐dependently, the development of thermal hyperalgesia and mechanical allodynia in neuropathic rats. Antagonists at cannabinoid CB1 or CB2 receptors, or at the transient receptor potential vanilloid type 1 receptor, each partially reversed effects induced by AM404. A complete reversal was obtained when the three antagonists were given together, suggesting that all three receptors are involved.AM404 treatment affected two pathways involved in the generation and maintenance of neuropathic pain, one mediated by nitric oxide (NO) and the other by cytokines. AM404 completely prevented the overproduction of NO and the overexpression of nNOS, inhibited the increase in tumour necrosis factorα(TNFα) and enhanced the production of interleukin‐10. Both NO and TNFαare known to contribute to the apoptotic process, which plays an important role in the establishment of chronic pain states. AM404 treatment prevented the increase in the ratio between pro‐ and anti‐apoptotic genebax/bcl‐2expression observed in the spinal cord of neuropathic rats.Taken together, these findings suggest that inhibition of endocannabinoid uptake, by blocking the putative anandamide carrier, results in the relief of neuropathic pain and may represent a novel strategy for treating chronic pain.British Journal of Pharmacology(2006)148, 1022–1032. doi:10.1038/sj.bjp.0706798
Kallidin‐like peptide mediates the cardioprotective effect of the ACE inhibitor captopril against ischaemic reperfusion injury of rat heart
Authors: Liu Xiuxin , Lukasova Martina , Zubakova Radka , Lewicka Sabina , Hilgenfeldt Ulrich 
Published: June 2006

The potential cardioprotective effect of ACE inhibitors has been attributed to the inhibition of bradykinin degradation. Recent data in rats documented a kallidin‐like peptide, which mimics the cardioprotective effect of ischaemic preconditioning. This study investigates in isolated Langendorff rat heart the effect of the ACE inhibitor captopril, the role of bradykinin, kallidin‐like peptide, and nitric oxide (NO).The bradykinin level in the effluent of the control group was 14.6 pg ml−1and was not affected by captopril in the presence or absence of kinin B2‐receptor antagonist, HOE140.The kallidin‐like peptide levels were approximately six‐fold higher (89.8 pg ml−1) and increased significantly by treatment with captopril (144 pg ml−1), and simultaneous treatment with captopril and HOE140 (197 pg ml−1).Following 30 min ischaemia in the control group, the creatine kinase activity increased from 0.4 to 53.4 U l−1. In the captopril group and in the captopril+L‐NAME group, the creatine kinase activity was significantly lower (18.5 and 22.8 U l−1). This beneficial effect of captopril was completely abolished by the kinin B2‐receptor antagonist, HOE140, as well as by the kallidin antiserum.Perfusion of the hearts with kallidin before the 30 min ischaemia, but not with bradykinin, yielded an approximately 50% reduction in creatine kinase activity after reperfusion.Pretreatment withL‐NAME alone and simultaneously with captopril, and with kallidin, respectively, suggests a kinin‐independent action of NO before the 30 min ischaemia on coronary flow and a kinin‐dependent action after ischaemia.These data show that captopril increases kallidin‐like peptide in the effluent. Kallidin‐like peptideviakinin B2receptor seems to be the physiological mediator of cardioprotective actions of captopril against ischaemic reperfusion injury. HOE140 as well as the kallidin antiserum abolished the cardioprotective effects of captopril.British Journal of Pharmacology(2006)148, 825–832. doi:10.1038/sj.bjp.0706799
A selection theorem in metric trees
Authors: Aksoy A. , Khamsi M. 
Published: June 2006

In this paper, we show that nonempty closed convex subsets of a metric tree enjoy many properties shared by convex subsets of Hilbert spaces and admissible subsets of hyperconvex spaces. Furthermore, we prove that a set-valued mappingT∗T^*of a metric treeMMwith convex values has a selectionT:M→MT: M\rightarrow Mfor whichd(T(x),T(y))≤dH(T∗(x),T∗(y))d(T(x),T(y))\leq d_H(T^*(x),T^*(y))for eachx,y∈Mx,y \in M. Here bydHd_Hwe mean the Hausdroff distance. Many applications of this result are given.
Simulation and quantification of enrichment and retention processes in the southern Benguela upwelling ecosystem
Authors: LETT CHRISTOPHE , ROY CLAUDE , LEVASSEUR ANNE , VAN DER LINGEN CARL D. , MULLON CHRISTIAN 
Published: June 2006

AbstractImportant environmental processes for the survival and recruitment of early life stages of pelagic fishes have been synthesized through Bakun's fundamental triad as enrichment, concentration and retention processes (A. Bakun, 1996, Patterns in the Ocean. Ocean Processes and Marine Population Dynamics. San Diego, CA, USA: University of California Sea Grant). This conceptual framework states that from favourable spawning habitats, eggs and larvae would be transported to and/or retained in places where food originating from enrichment areas would be concentrated. We propose a method for quantifying two of the triad processes, enrichment and retention, based on the Lagrangian tracking of particles transported within water velocity fields generated by a three‐dimensional hydrodynamic model. We apply this method to the southern Benguela upwelling ecosystem, constructing putative maps of enrichment and retention. We comment on these maps regarding main features of the circulation in the region, and investigate seasonal variability of the processes. We finally discuss the results in relation to available knowledge on the reproductive strategies of two pelagic clupeoid species abundant in the southern Benguela, anchovy (Engraulis encrasicolus) and sardine (Sardinops sagax). Our approach is intended to be sufficiently generic so as to allow its application to other upwelling systems.
Predator related oviposition site selection of aquatic beetles (Hydroporus spp.) and effects on offspring life‐history
Authors: BRODIN TOMAS , JOHANSSON FRANK , BERGSTEN JOHANNES 
Published: June 2006

Summary1. Theory predicts that natural selection should favour females that are able to correctly assess the risk of predation and then use that information to avoid high‐risk oviposition sites to reduce the risk of offspring predation. Despite the potential significance of such behaviour on individual fitness, population dynamics and community structure, relatively few studies of oviposition behaviour connected to the risk of predation have been carried out.2. However, some recent studies suggest that oviposition site selection in response to risk of predation may be a common phenomenon, at least among amphibians and mosquitoes. A vast majority of previous studies have, however, neglected to investigate how the offspring are affected, in terms of fitness related parameters, by the maternal oviposition site choice.3. In an outdoor artificial pond experiment we tested the oviposition site selection of female aquatic beetles (Hydroporus spp.) in relation to the presence or absence of a predatory fish (Perca fluviatilis). In addition, we monitored how the oviposition site selection affected the behaviour, growth and food resource of the progeny.4. We show that free‐flying females of the aquatic beetles Hydroporus incognitus and H. nigrita prefer to oviposit in waters without fish compared with waters with fish. Larval activity of Hydroporus spp. was unaffected by fish presence. Our results indicate that beetle larvae from females that do lay eggs in waters with fish show increased growth compared with larvae in waters without fish. We explain this difference in growth by a higher per‐capita food supply in the presence of a fish predator. This finding may have important implications for our understanding of how the variance of oviposition site selection in a population is sustained.