bluuebunny/crossref_metadata_2025 huggingface dataset:
Diversity of the cadmium‐containing carbonic anhydrase in marine diatoms and natural waters
Authors: Park Haewon , Song Bongkeun , Morel François M. M.
Published: October 2006

A recent report of a novel carbonic anhydrase (CDCA1) with Cd as its metal centre in the coastal diatom Thalassiosira weissflogii has led us to search for the occurrence of this Cd enzyme (CDCA) in other marine phytoplankton and in the environment. Using degenerate primers designed from the published sequences from T. weissflogii and a putative sequence in the genome of Thalassiosira pseudonana, we show that CDCA is widespread in diatom species and ubiquitous in the environment. All detected genes share more than 64% amino acid identity with the CDCA of T. pseudonana. Analysis of the amino acid sequence of CDCA shows that the putative Cd binding site resembles that of beta‐class carbonic anhydrases (CAs). The prevalence of CAs in diatoms that presumably contain Cd at their active site probably reflects the very low concentration of Zn in the marine environment and the difficulty in acquiring inorganic carbon for photosynthesis. The cdca primers developed in this study should be useful for detecting cdca genes in the field, and studying the conditions under which they are expressed.
Do Formula or Competitive Grant Funds Have Greater Impacts on State Agricultural Productivity?
Authors: Huffman Wallace E. , Evenson Robert E.
Published: October 2006

This article examines the impact of public agricultural research and extension on agricultural total factor productivity at the state level. The objective is to establish whether federal formula or competitive grant funding of agricultural research has a greater impact on state agricultural productivity. A pooled cross‐section time‐series model of agricultural productivity is fitted to annual data for forty‐eight contiguous states over 1970–1999. Our results show that public agricultural research and agricultural extension have statistically significant positive impacts on state agricultural productivity. In addition, Hatch formula funding has a larger impact on agricultural productivity than federal competitive grant funding, and a reallocation of Hatch formula funds to competitive grant funding would lower agricultural productivity. This seems unlikely to be a socially optimal policy. Furthermore, from a cost‐benefit perspective, our study shows that the social marginal annualized real rate of return to public resources invested in agricultural research is 49–62%, and to public agricultural extension, the rate is even larger.
Are Revisions to USDA Crop Production Forecasts Smoothed?
Authors: Isengildina Olga , Irwin Scott H. , Good Darrel L.
Published: October 2006

This article uses Nordhaus' framework to determine the efficiency of the revision process for USDA corn and soybean production forecasts over the 1970/1971 through 2004/2005 marketing years. Positive autocorrelation and consistency of directional changes in forecast revisions suggest these forecasts are “smoothed.” Evidence is provided that the loss in forecast accuracy due to smoothing is statistically and economically significant in several cases. A conservative bias in farm operators' assessments of yield potential and in the procedure for translating enumerator's information about plant fruit counts into objective yield estimates are identified as plausible sources of smoothing.
A Situated Knowledge Representation of Geographical Information
Authors: Gahegan Mark , Pike William
Published: October 2006

In this paper we present an approach to conceiving of, constructing and comparing the concepts developed and used by geographers, environmental scientists and other earth science researchers to help describe, analyze and ultimately understand their subject of study. Our approach is informed by the situations under which concepts are conceived and applied, captures details of their construction, use and evolution and supports their ultimate sharing along with the means for deep exploration of conceptual similarities and differences that may arise among a distributed network of researchers. The intent here is to support different perspectives onto GIS resources that researchers may legitimately take, and to capture and compute with aspects of epistemology, to complement the ontologies that are currently receiving much attention in the GIScience community.
VIRTUAL REALITY, ONTOLOGY, AND VALUE
Authors: MOORADIAN NORMAN
Published: October 2006

Abstract: This article raises the question of how the ontological status of virtual objects bears on their intrinsic value. If virtual objects are unreal or less real than physical objects, does it mean that they will have less intrinsic value? If they have intrinsic value, what are the explanations for this value, and how do they relate to the ontological status of the virtual objects? First, the article reviews recent work concerning the ontological status of virtual reality and virtual objects. Second, it argues that in some cases the ontological status of virtual objects does undermine the value placed in them, in that the objects can fail to have the properties that ground the value attributions made to them, while in other cases their ontological status is not important. Finally, the article relates the grounding of value attributions to philosophical theories of value, in particular, perfectionism and hedonism.
‘Government Without Statehood’? Anthropological Perspectives on Governance and Sovereignty in the European Union
Authors: Shore Cris
Published: October 2006

Abstract:  It has long been argued that the EU is creating a new kind of constitutional order in Europe, one variously hailed as ‘transnational’, ‘supranational’, even ‘post‐national’. Among the many theoretical descriptors used to capture the elusive character of the EU's unique political order are ‘multi‐level polity’, ‘civic tolerance’, and ‘governance without government’. Yet despite its success in developing the legal, economic, and institutional framework for this emerging polity, one key factor continues to undermine the project for European construction: the lack of a common culture or identity around which Europeans can unite. Drawing on anthropological research in Brussels, this article explores the implications of the EU's absent demos. It also outlines some of the strategies the European Commission has used to address this problem and resolve its democratic deficit. Taking up recent debates developed by a number of EU scholars, I highlight some of the contradictions and theoretical weaknesses with the concept of ‘governance’ in an EU context. Reversing Wallace's dictum about ‘government without statehood’, I ask whether EU governance might not, in fact, be better construed as ‘statehood without government’ and a new form of ‘governmentality’.
Chinese Perceptions of the European Union: A Review of Leading Chinese Journals
Authors: Men Jing
Published: October 2006

Abstract:  As a result of the rapid development of EU–China relations, an increasing amount of scholars in China focus their research on the European Union and the nature of the bilateral relationship. As most of them publish their research results in the academic journals in China, it is necessary to have a review of these journals in order to understand Chinese perceptions of the European Union. In order to fulfil this task, this article first briefly examines the Chinese journals to be reviewed, and explains why these journals have been chosen. Via the analysis of the articles published in the leading Chinese journals in the past five years, the article presents how the Chinese perceive the EU and its global role, explores EU–US relations and EU–China relations. By presenting the most up‐to‐date research on the EU studies in China, the article serves as a timely and meaningful piece to help enhance mutual understanding between the EU and China.
Trade and Diversity: Is There a Case for ‘Cultural Protectionism?’
Authors: Eckel Carsten
Published: October 2006

In contrast to the predictions of standard models of international trade, globalization critics are claiming that trade destroys diversity. We demonstrate that with endogenous sunk costs, trade integration in horizontally differentiated industries can indeed lead to a fall in diversity. Consumers are faced with a tradeoff between gains in real income and a loss in diversity, so that the impact on welfare is ambiguous. However, it is possible through fiscal policies to replicate pre-trade choices and still realize gains in real income. Thus, calls for a ‘cultural protectionism’ are not justified.
Asymptomatic pontine myelinolysis
Authors: Razvi S. S. M. , Leach J. P.
Published: October 2006

A 43‐year‐old lady presented with bilateral foot drop due to alcohol‐related peripheral neuropathy. There was no history of electrolyte disturbance or altered consciousness. Cranial nerve, bulbar and pyramidal symptoms and signs were absent. Nerve conduction studies confirmed the neuropathy. Inadvertently requested neuroimaging of brain demonstrated signal change typical of central pontine myelinolysis. Asymptomatic pontine myelinolysis occurs rarely in alcoholics in the absence of bulbar dysfunction. It is important for physicians to be aware of the clinical entity of asymptomatic pontine myelinolysis to avoid misinterpretation of abnormalities detected on cerebral imaging in alcoholic individuals.
Interrelationship and Familiality of Dyslexia Related Quantitative Measures
Authors: Schulte‐Körne G. , Ziegler A. , Deimel W. , Schumacher J. , Plume E. , Bachmann C. , Kleensang A. , Propping P. , Nöthen M. M. , Warnke A. , Remschmidt H. , König I. R.
Published: October 2006

Dyslexia is a complex gene‐environment disorder with poorly understood etiology that affects about 5% of school‐age children. Dyslexia occurs in all languages and is associated with a high level of social and psychological morbidity for the individual and their family; approximately 40‐50% have persistent disability into adulthood. The core symptoms are word reading and spelling deficits, but several other cognitive components influence the core phenotype.

A broad spectrum of dyslexia related phenotypes, including phonological decoding, phoneme awareness, orthographic processing, short‐term memory, rapid naming and basic mathematical abilities, were investigated in large sample of 287 German dyslexia families. We explored the interrelationship between the component phenotypes using correlation and principal component analyses (PCA). In addition, we estimated familiality for phenotypes as well as for the factors suggested by PCA.

The correlation between the component phenotypes varied between −0.1 and 0.7. The PCA resulted in three factors: a general dyslexia factor, a speed of processing factor and a mathematical abilities factor. The familiality estimates of single components and factors ranged between 0.25 and 0.63.

Instead of analyzing single dyslexia‐related components, multivariate analyses including factor analytic approaches may help in the identification of susceptibility genes.
The structure of the cushions in the feet of African elephants (Loxodonta africana)
Authors: Weissengruber G. E. , Egger G. F. , Hutchinson J. R. , Groenewald H. B. , Elsässer L. , Famini D. , Forstenpointner G.
Published: October 2006

The uniquely designed limbs of the African elephant,Loxodonta africana, support the weight of the largest terrestrial animal. Besides other morphological peculiarities, the feet are equipped with large subcutaneous cushions which play an important role in distributing forces during weight bearing and in storing or absorbing mechanical forces. Although the cushions have been discussed in the literature and captive elephants, in particular, are frequently affected by foot disorders, precise morphological data are sparse. The cushions in the feet of African elephants were examined by means of standard anatomical and histological techniques, computed tomography (CT) and magnetic resonance imaging (MRI). In both the forelimb and the hindlimb a 6th ray, the prepollex or prehallux, is present. These cartilaginous rods support the metacarpal or metatarsal compartment of the cushions. None of the rays touches the ground directly. The cushions consist of sheets or strands of fibrous connective tissue forming larger metacarpal/metatarsal and digital compartments and smaller chambers which were filled with adipose tissue. The compartments are situated between tarsal, metatarsal, metacarpal bones, proximal phalanges or other structures of the locomotor apparatus covering the bones palmarly/plantarly and the thick sole skin. Within the cushions, collagen, reticulin and elastic fibres are found. In the main parts, vascular supply is good and numerous nerves course within the entire cushion. Vater–Pacinian corpuscles are embedded within the collagenous tissue of the cushions and within the dermis. Meissner corpuscles are found in the dermal papillae of the foot skin. The micromorphology of elephant feet cushions resembles that of digital cushions in cattle or of the foot pads in humans but not that of digital cushions in horses. Besides their important mechanical properties, foot cushions in elephants seem to be very sensitive structures.
HARMONIZING REGULATIONS FOR BIOMEDICAL RESEARCH: A CRITICAL ANALYSIS OF THE US AND VENEZUELAN SYSTEMS
Authors: DI TILLIO‐GONZALEZ DANNIE , FISCHBACH RUTH L.
Published: October 2006

This article aims to compare the national legal systems that regulate biomedical research in an industrialized country (United States) and a developing country (Venezuela). A new international order is emerging in which Europe, Japan and the United States (US) are revising common guidelines and harmonizing standards. In this article, we analyze – as an example – the US system. This system is controlled by a federal agency structured to regulate research funded by the federal government uniformly, either in the US or abroad. In contrast, in Venezuela, a developing country, the creation of a centralized system is a slow process. Different types of ethical committees review research projects using non‐uniform criteria. Consequently, various parallel organizations that conduct biomedical research, such as universities, research institutes and private hospitals have diverse regulations operating at a local level. Thus, the most relevant difference between the Venezuelan and the US systems is the degree of standardization. In the US, the review process is performed by institutional review boards (IRBs), which have a similar organization and maintain relationships with a centralized agency, following standard regulations. Although new proposals for establishing national regulations are currently being considered in Venezuela, the success of these initiatives will depend on promoting governmental efforts to create a more structured centralized system supported by a national regulatory framework. This system will need governmental financial support at all levels. This article proposes an integrated system to regulate research with human participants in Venezuela and other developing countries.
Dynamics in longitudinal eye movements and corneal shape
Authors: Robert Iskander D. , Kasprzak Henryk T.
Published: October 2006

The magnitude and character of longitudinal movements of the eye were studied in the context of high speed videokeratoscopy. It was of interest to determine whether these dynamic changes in the eye movements can affect the corneal shape and its estimation. A high speed videokeratoscope with a sampling frequency of 50 Hz was used for measuring the corneal apex movements as well as for measuring variations in the best‐fit sphere radius and central radius of curvature. The magnitude of the measured longitudinal apex movements could reach over 200 μm showing a slow trend. The estimated local changes of the apex movements that could be associated with the cardiopulmonary system were about 40–50 μm. The temporal variations in the equivalent estimated central radius of curvature ranged between 10 and 15 μm. Spectral analysis of the longitudinal eye movements revealed strong signatures of the pulse and respiration signals as well as the assumed blink control signal. No clear association between the longitudinal apex movements and the corneal curvature was found. However, very slow significant changes in the corneal shape were observed. The central radius of curvature of the cornea revealed slow changes of up to 120 μm. Understanding the nature of such changes will be of benefit in ophthalmic applications requiring highly accurate measurements of corneal shape, such as contact lens design and refractive surgery.
Approximating ocular surfaces by generalised conic curves
Authors: Kasprzak Henryk T. , Robert Iskander D.
Published: October 2006

Most of the optical models of the human eye use simple conic functions to represent its individual components such as corneal surfaces and the surfaces of the crystalline lens. Although a conic function provides an acceptable approximation for most anatomical eye surfaces, it also leads to a simple optical analysis of the whole eye system. To fill the gap between the classical use of conic surfaces and the use of more sophisticated functions that often invoke numerically expensive procedures in the optical analysis, a functional generalisation of the conic curve is proposed. A detailed derivation of the generalised conic function is presented for a two‐dimensional (meridional) case. This is followed by a three‐dimensional surface approximation. Examples are given in which the superiority of the proposed approximation over a classical conic function as well as the hyperbolic cosine approximation is evident. In particular, it is shown that for an average total corneal profile, the proposed generalisation results in a residual height error that is of an order smaller than those achieved with the conic and hyperbolic cosine approximations. In conclusion, the proposed generalised conic function can be a useful tool in eye modelling, where the simplicity of expression is often desirable.
UNDER THE HAMMER: RESIDUES RESULTING FROM PRODUCTION AND MICROWEAR ON EXPERIMENTAL STONE TOOLS*
Authors: BYRNE L. , OLLÉ A. , VERGÈS J. M.
Published: October 2006

This paper presents the results of an experimental programme investigating the effects of production processes on stone tools and their interference with use‐related features. In the first part of the experimental programme, a series of flint flakes was retouched with different kinds of hammers in order to assess the extent and nature of percussion residues. After careful environmental scanning electron microscope (ESEM) observation and energy‐dispersive X‐ray (EDX) analysis, the retouched flakes were thoroughly cleaned and the underlying flint deformation was recorded. The second part of the experimental programme involved selecting several uncleaned retouched pieces for use in short woodworking, hide‐processing and butchery experiments. These pieces were observed and analysed before, during and after use. Some of the percussion features proved to be surprisingly resistant to use, and in some cases turned out to be strikingly similar in appearance to use‐generated features.
A REVIEW OF SUPERVISED AND UNSUPERVISED PATTERN RECOGNITION IN ARCHAEOMETRY*
Authors: BAXTER M. J.
Published: October 2006

Principal component, cluster and discriminant analysis are multivariate statistical methods that are widely used in archaeometry. They are examples of what are known in some literatures as unsupervised and supervised learning methods. Over the past 20 years or so, a wide variety of other learning methods have been developed that take advantage of modern computing power and, in some cases, have been designed to handle data sets more complex than those often used in archaeometric data analysis. To date, these methods have had little impact on archaeometry. This paper reviews, in a largely non‐technical manner, the ideas behind these newer methods; illustrates their use on a variety of data sets; and attempts to assess their potential for future archaeometric use.
A NEW THERMOLUMINESCENCE DATING TECHNIQUE FOR HEATED FLINT*
Authors: RICHTER D. , KRBETSCHEK M.
Published: October 2006

A new thermoluminescence (TL) technique for determining the age of heated flint artefacts from archaeological sites is presented. It is a variant of the SAR protocol, which is usually used for OSL dating of sediment, but it is not based on a presumed model for fitting the dose–response curve. Dose recovery tests as well as comparisons with standard protocols show the accuracy of the new technique. It is found that the sensitivity of the thermoluminescence (TL) signal of flint in the orange–red waveband does not show severe changes due to the heating process while measuring the TL. This allows the application of a short SAR procedure, which requires only two dose points. The technique does not require as much instrument time as other SAR techniques, and thus is advantageous for dating very old samples. The major advantage of this new technique is the small amount of sample material required, which allows the dating of samples that are too small for standard TL dating techniques.
Immigrant Mental Health and Unemployment*
Authors: KENNEDY STEVEN , MCDONALD JAMES TED
Published: October 2006

In this paper we examine how the stresses associated with the transition to a new country combined with additional stress arising from a period of unemployment affect the mental health of immigrants. Australian immigrants are found to have poorer mental health at 6 months after arrival in Australia compared with 18 and 42 months. Furthermore, unemployment, and especially a long duration of unemployment, is found to be associated with poor mental health. We found that although immigrant women appear unaffected by their spouses’ labour force status, there is evidence that immigrant men's mental health is affected by spouse labour force status.
The interaction between reaction and deformation: an experimental study using a biotite + plagioclase + quartz gneiss
Authors: HOLYOKE C. W. , TULLIS J.
Published: October 2006

Metamorphic reactions commonly accompany ductile deformation of crustal rocks. We performed an experimental study to determine: (i) the effect of syn‐deformation reaction on strain weakening and localization, and (ii) the effect of crystal plastic deformation on reaction extent and distribution. Experiments were conducted on a fine‐grained gneiss (58 vol.% quartz, forming the interconnected matrix, 13 vol.% biotite, 28 vol.% plagioclase and 1 vol.% garnet/Fe‐Ti oxides). General shear experiments were performed at 745 and 800 °C, 1.5 GPa, two strain rates, and shear strain (γ) from 0.6 to 5, yielding three suites with initial phase strength contrast between the matrix quartz and weak biotite of 45×, 25× and 10×; hydrostatic experiments were performed on cores and powders at 750 and 800 °C and 1.5–2 GPa for the same times. At these conditions, biotite reacts with plagioclase and quartz to form garnet, K‐feldspar and water (no melt was observed). Greater reaction extent was observed in deformed samples than in equivalent hydrostatic samples, because of the increased surface area and internal strain energy. In all of the deformed samples, reaction contributes to strain weakening, due principally to a switch to grain boundary sliding in the fine‐grained reaction products. The degree to which syn‐deformational reaction causes strain weakening and localization in this polyphase aggregate depends on the phase strength contrast and how it evolves. In samples with low‐phase strength contrast, strain and reaction are homogeneously distributed; however, in samples with high‐phase strength contrast, ductile strain and reaction interact positively to produce a narrow ductile shear zone. Similar concentration of reaction is observed in some natural ductile shear zones.
Variations in rates of nucleation and growth of biotite porphyroblasts
Authors: HIRSCH D. M. , CARLSON W. D.
Published: October 2006

Differences in rates of nucleation and diffusion‐limited growth for biotite porphyroblasts in adjacent centimetre‐scale layers of a garnet‐biotite schist from the Picuris Mountains of New Mexico are revealed by variations in crystal size and abundance between two layers with strong compositional similarity. Relationships between fabrics recorded by inclusion patterns in biotite and garnet porphyroblasts are interpreted to reflect garnet growth following biotite growth, without substantial alteration of the biotite sizes. Sizes and locations of biotite crystals, obtained via high‐resolution X‐ray computed tomography, document that of the two adjacent layers, one has a larger mean crystal volume (9.5 × 10−4v. 2.4 × 10−4 cm3), fewer biotite crystals per unit volume (232 v. 576 crystals cm−3), and a higher volume fraction of biotite (23%v. 14%). The two layers have similar mineral assemblages and mineral chemistry. Both layers show evidence for diffusional control of nucleation and growth. Pseudosection analysis suggests that the large‐biotite layer began to crystallize biotite at a temperature ∼67 °C greater than the small‐biotite layer. Diffusion rates differed between layers, because of their different temperature ranges of crystallization, but this effect can be quantified. The bulk compositional difference between the layers, manifested in different modal amounts of biotite, has an effect on the biotite sizes that is also quantifiable and insufficient to account for the difference in biotite size. After these other possible causes of variation in crystal sizes have been eliminated, variability in nucleation and diffusion rates remain as the dominant factors responsible for the difference in porphyroblastic textures. Numerical simulations suggest that relative to the small‐biotite layer, the large‐biotite layer experienced elevated diffusion rates because of the higher crystallization temperature, as well as increased nucleation rates in order to achieve the observed size and number density of crystals. The simulations can replicate the observed textures only by invoking unreasonably large values for the thermal dependence of nucleation rates (activation energies), strongly suggesting that the observed textural differences arise from variations between layers in the abundance and energetics of potential nucleation sites.
Tailoring Management Strategies for the Patient With Menstrual Migraine: Focus on Prevention and Treatment
Authors: Tepper Stewart J.
Published: October 2006

Many women report an increased frequency of headaches around the time of menses. For some women, these headaches are more severe, of longer duration, and lead to greater disability than those occurring at other times in the menstrual cycle. A headache diary is critical to properly diagnose menstrual migraine (MM) by prospectively documenting headache days, severity of headache, and the headaches' relationship to menses. In women with diagnosed MM, acute treatment has been proven to be effective in randomized clinical trials. For those women who have predictable periods and may require preventive therapy, short‐term prevention is a reasonable approach due to the predictability of MM. Although several agents (eg, naproxen sodium, magnesium, triptans) have been evaluated for prevention of MM, all but triptans have been assessed in small trials of between 20 and 35 women. Naratriptan, frovatriptan, and, most recently, zolmitriptan have been proven effective in preventing MM. Triptans are generally well tolerated, and the long‐term safety of these agents is currently being evaluated. The flexibility of using acute and preventive therapy allows physicians to tailor treatment of MM and meet the needs of individual patients.
Catastrophe Modeling in the Classroom
Authors: Born Patricia , Martin William
Published: October 2006

Abstract

Catastrophes are by definition rare, which makes it difficult to project future losses using historical loss information. Catastrophe modelers have developed alternative methodologies based on sophisticated techniques that combine physics, meteorology, engineering, statistics, actuarial sciences, and other disciplines to provide estimates of the likelihood of losses from extreme events. This article discusses the basics of catastrophe modeling and describes an approach to implementing a lesson on catastrophe modeling in the insurance curriculum.
Magnitude of Error Introduced by Application of Heart Rate Correction Formulas to the Canine QT Interval
Authors: King Andrew , Bailie Marc , Olivier N. Bari
Published: October 2006

Background: Accurate detection of drug‐induced QT interval changes is often confounded by concurrent heart rate changes. Application of heart rate correction formulas has been the traditional approach to account for heart rate–induced QT interval changes, and thereby identify the direct effect of the test article on cardiac repolarization. Despite numerous recent studies identifying the imprecision of these formulas they continue to be applied.

Methods: Using a chronic atrioventricular dissociated His‐paced canine model, heart rate correction methods were evaluated for their ability to generate a corrected QT interval independent of original heart rate. Additionally, His bundle pacing at a heart rate of 60 beats/min allowed calculation of the magnitude of error introduced by application of heart rate correction formulas.

Results: Of the fixed parameter heart rate correction formulas, only Van de Water was able to predict corrected QT values independent of the original heart rate. The magnitude of error discovered by application of heart rate correction formulas varied, but in many cases was very large. Bazett's formula was associated with a mean overcorrection of 67.9 ms; Fridericia's 28.7 ms. Van de Water was the best fixed parameter formula with a mean error of 10.8 ms. As expected, group and individual corrections derived from linear regression of the HR‐QT data offered improvement over the traditional formulas. Both were able to predict QTc values independent of the heart rate. However, errors of the magnitude of 10 and 6 ms, respectively, were still introduced.

Conclusion: Van de Water and linear regression correction methods were superior to others in this study, but all methods generated QTc errors equal to or much greater than the magnitude of interest for drug safety evaluation.
Correlation Between Beat‐to‐Beat QT Interval Variability and Impaired Left Ventricular Function in Patients with Previous Myocardial Infarction
Authors: Hiromoto Kenji , Shimizu Hiroki , Mine Takanao , Masuyama Tohru , Ohyanagi Mitsumasa
Published: October 2006

Background: Beat‐to‐beat QT interval variability (QTV) is associated with sudden cardiac death and New York Heat Association functional class severity. We sought to evaluate the relationship between QTV and left ventricular (LV) function in patients with previous myocardial infarction (MI).

Methods: Fifty‐nine patients with previous anterior MI were enrolled. LV ejection fraction (EF), LV end‐systolic volume index (LVESVI), and LV end‐diastolic volume index (LVEDVI) were measured by LV contrast angiography. QT interval was measured by automated analysis of 512‐beat records of 12‐lead electrocardiogram. The mean interval, standard deviation and variance in RR and QT intervals, and the QT variability index (QTVI) were calculated for each patient using two leads that corresponded with and without the infarction site. High‐frequency power, low‐frequency power, total‐frequency power, and the ratio of low‐frequency to high‐frequency power in RR and QT intervals were calculated.

Results: While measured indices of RR intervals and indices of QT intervals, which did not correspond with the infarction site, did not correlate with differences in LV function, measured indices of QT intervals, which corresponded with the infarction site, did correlate with differences in LV function. However, there were no correlations between the ratio of low‐frequency to high‐frequency power in QT intervals and EF or LVEDVI. Correlations between QTVI and LV function were observed, particularly between QTVI and LVESVI (r = 0.712, P < 0.0001).

Conclusion: In patients with previous anterior MI, there was variability in temporal dispersion of QT interval and a strong correlation between QTV corresponded with the infarcted site and LV function.
Heart Rate Variability in Young Women with Polycystic Ovary Syndrome
Authors: Yildirir Aylin , Aybar Funda , Kabakci Giray , Yarali Hakan , Oto Ali
Published: October 2006

Background: Limited data are available related to the effects of sex hormones on cardiac autonomic function. Few studies investigated the heart rate variability (HRV) parameters during regular menstrual cycle or in postmenopausal women using hormone replacement therapy, but the results were contradictory. The aim of the study was to compare the characteristics of the autonomic innervation of the heart in polycystic ovary syndrome (PCOS) patients with regularly cycling controls.

Methods: Thirty PCOS patients and 30 healthy regularly cycling controls were included in the study. Groups were compared with respect to age and various cardiovascular risk factors. Characteristics of autonomic innervation of the heart were evaluated with HRV. Power spectral analysis of HRV was performed to calculate the low frequency peak (LF 0.04–0.15 Hz), high‐frequency peak (HF 0.15–0.40 Hz), LF in normalized unit (LF nu), HF in normalized unit (HF nu) and LF/HF ratio.

Results: PCOS patients had adverse cardiovascular risk profile than controls. As the HRV parameters, PCOS patients had significantly higher LF nu (P = 0.005) and LF/HF ratio (P = 0.001) and significantly lower HF (P = 0.006) and HF nu (P < 0.001) compared to controls.

Conclusion: Autonomic innervation of the heart can be affected in PCOS with increased sympathetic and decreased parasympathetic components of HRV. As a result, sympathetic to parasympathetic ratio may increase in PCOS. This finding should be confirmed with larger studies also evaluating the clinical implications of altered HRV parameters.
Reproducibility of Computerized Measurements of QT Interval from Multiple Leads at Rest and During Exercise
Authors: Hekkala Anna‐Mari , Väänänen Heikki , Swan Heikki , Oikarinen Lasse , Viitasalo Matti , Toivonen Lauri
Published: October 2006

Background: Accurate measurement of the QT interval is important for diagnosing long QT syndrome (LQTS), and in research on determinants of ventricular repolarization time. We tested automatic analysis of QT intervals from multiple ECG leads on chest.

Methods: Eleven healthy volunteers and 10 genotyped LQTS patients were tested at rest and during exercise with a bicycle ergometer twice 1–31 months apart. Electrocardiograms were recorded with the body surface potential mapping system, and 12 precordial channels were selected for analysis. Averaged QT peak and QT end intervals were determined with an automated algorithm, and the difference QT end minus QT peak (Tp‐e) was calculated. Repeatability was assessed by coefficient of variation (CV) between measurements.

Results: Within one test at rest the QT end intervals were highly repeatable with CV 0.6%. In repeated tests CV was 4.4% for QT end interval and 3.5% when the QT interval was corrected for heart rate. In exercise test at specified heart rates, mean CV was 3.0% for QT end and 2.9% for QT peak interval. The CV of Tp‐e interval was 10.2% at rest, and 9.3% in exercise test. Reproducibility was comparable between healthy subjects and LQTS patients.

Conclusions: The BSPM system with automated analysis produced accurate and highly repeatable QT interval measurements. Reproducibility was adequate also over prolonged time periods both at rest and in exercise stress test. The method can be applied in studying duration of ventricular repolarization time in different physiologic and pharmacologic interventions.
Single Mothers “Do” Family
Authors: Nelson Margaret K.
Published: October 2006

This paper explores how single mothers both incorporate others into family life (e.g., when they ask others to care for their children) and simultaneously “do families” in a manner that holds out a vision of a “traditional” family structure. Drawing on research with White, rural single mothers, the author explores the manner in which these women both endorse their children’s attachment to other caregivers and maintain boundaries around issues of discipline and attachment vis‐à‐vis these others. The author demonstrates that single mothers are willing to share this protected realm of family life with a new man (a fiancé or cohabiting boyfriend) as they pursue the goal of what has been called the “Standard North American Family.”
Assessing Family Outcomes: Psychometric Evaluation of the Beach Center Family Quality of Life Scale
Authors: Hoffman Lesa , Marquis Janet , Poston Denise , Summers Jean Ann , Turnbull Ann
Published: October 2006

There is currently a lack of reliable scales with which to assess the construct of family quality of life, particularly for families who have children with disabilities. The current work presents 2 studies, including a total of 488 families with children with disabilities, which were conducted to complete the development of a scale to assess family quality of life. The measure was refined through confirmatory factor analyses into 25 items that assess 5 domains of Family Quality of Life: Family Interaction, Parenting, Emotional Well‐Being, Physical/Material Well‐Being, and Disability‐Related Support. Each subscale was found to be unidimensional and internally consistent. An initial examination of test‐retest reliability and convergent validity is also presented. Implications for future research, scale use, and policy are discussed.
Nonmarital Fertility and the Effects of Divorce Rates on Youth Suicide Rates
Authors: Messner Steven F. , Bjarnason Thoroddur , Raffalovich Lawrence E. , Robinson Bryan K.
Published: October 2006

Using pooled, time‐series data for a sample of 15 developed nations, we assess the effect of divorce rates on gender‐specific suicide rates for youths aged 15 – 19 with models of relative cohort size, lagged nonmarital fertility, and an interaction term for divorce rates and nonmarital fertility. The results reveal that, for young men, relative cohort size is positively related to suicide rates, and divorce rates interact with lagged nonmarital fertility. The interaction effect indicates that increases in divorces are especially consequential for suicide cohorts of male youths who were born in periods of high nonmarital fertility. For female youths, only divorce rates exert a significant effect on suicide rates, and it is a positive, main effect.
Characterization of novel M‐superfamily conotoxins with new disulfide linkage
Authors: Han Yu‐Hong , Wang Qi , Jiang Hui , Liu Li , Xiao Cai , Yuan Duo‐Duo , Shao Xiao‐Xia , Dai Qiu‐Yun , Cheng Ji‐Sheng , Chi Cheng‐Wu
Published: October 2006

The M‐superfamily with the typical Cys framework (–CC–C–C–CC–) is one of the seven major superfamilies of conotoxins found in the venom of cone snails. Based on the number of residues in the last Cys loop (between C4 and C5), M‐superfamily conotoxins can be provisionally categorized into four branches (M‐1, M‐2, M‐3, M‐4) [Corpuz GP, Jacobsen RB, Jimenez EC, Watkins M, Walker C, Colledge C, Garrett JE, McDougal O, Li W, Gray WR, et al. (2005) Biochemistry44, 8176–8186]. Here we report the purification of seven M‐superfamily conotoxins from Conus marmoreus (five are novel and two are known as mr3a and mr3b) and one known M‐1 toxin tx3a from Conus textile. In addition, six novel cDNA sequences of M‐superfamily conotoxins have been identified from C. marmoreus, Conus leopardus and Conus quercinus. Most of the above novel conotoxins belong to M‐1 and M‐2 and only one to M‐3. The disulfide analyses of two M‐1 conotoxins, mr3e and tx3a, revealed that they possess a new disulfide bond arrangement (C1–C5, C2–C4, C3–C6) which is different from those of the M‐4 branch (C1–C4, C2–C5, C3–C6) and M‐2 branch (C1–C6, C2–C4, C3–C5). This newly characterized disulfide connectivity was confirmed by comparing the HPLC profiles of native mr3e and its two regioselectively folded isoforms. This is the first report of three different patterns of disulfide connectivity in conotoxins with the same cysteine framework.
Comparison of Early and Late Toxic Effects of Sulfur Mustard in Iranian Veterans
Authors: Balali‐Mood Mahdi , Hefazi Mehrdad
Published: October 2006

Abstract:Sulfur mustard is an alkylating agent that reacts with ocular, respiratory, cutaneous, and bone marrow tissues, resulting in early and late toxic effects. We compare these effects based on the experience in Iranian veterans exposed to the agent during the Iran‐Iraq conflict (1983–88). The first clinical manifestations of sulfur mustard poisoning occurred in the eyes with a sensation of grittiness, lacrimation, photophobia, blepharospasm, and corneal ulceration. Respiratory effects appeared as rhinorhea, laryngitis, tracheobronchitis, and dyspnoea. Skin lesions varied from erythema to bullous necrotization. Initial leukocytosis and lymphopenia returned to normal within four weeks in recovered patients, but marked cytopenia with bone marrow failure occurred in fatal cases. Late toxic effects of sulfur mustard were most commonly found in lungs, skin and eyes. Main respiratory complications were chronic obstructive pulmonary disease, bronchiectasis, asthma, large airway narrowing, and pulmonary fibrosis. Late skin lesions were hyperpigmentation, dry skin, atrophy, and hypopigmentation. Fifteen of the severely intoxicated patients were diagnosed with delayed keratitis, having corneal vascularization, thinning, and epithelial defect. Respiratory complications exacerbated over time, while cutaneous and ocular lesions decreased or remained constant. Both the severity and frequency of bronchiectatic lesions increased during long‐term follow‐up. The only deteriorating cutaneous complication was dry skin. The maximum incidence of delayed kaeratitis was observed 15 to 20 years after initial exposure. Being suggested as the main cause ofassociated with malignancies and recurrent infections, natural killer cells were significantly lower 16 to 20 years after intoxication.
Zidovudine Inhibits Protein Kinase C Activity in Human Chronic Myeloid (K562) Cells
Authors: Carnicelli Veronica , Di Giulio Antonio , Bozzi Argante , Strom Roberto , Oratore Arduino
Published: October 2006

Abstract:In this paper we show that human erythroleukaemia (K562) cells exhibited a significant inhibition of protein kinase C activity when cells were exposed to 40 μM zidovudine in a time interval of 5–180 min., whereas prolonged treatment (24 hr) was uneffective. The addition of an excess of thymidine (125:1, mol:mol), in the cell suspension with or without zidovudine fully restored the protein kinase C activity. Interestingly, either in cell homogenates and in commercially purified rat brain protein kinase C, both zidovudine and its monophosphate derivative, caused inhibition that was higher than in intact cells. This inhibition reached a maximal value of 45% when zidovudine or zidovudine monophosphate were incubated with the pure commercial enzyme and in this case the addition of thymidine did not prevent the enzyme inhibition. The conclusions from these data are that either zidovudine or zidovudine monophosphate interact directly with the pure enzyme, causing inhibition, while in intact cells exposed to the drug, zidovudine monophosphate appears to be the main metabolite responsible for protein kinase C inhibition.
Manufacturing and Service Supply Chain Performance: A Comparative Analysis
Authors: Sengupta Kaushik , Heiser Daniel R. , Cook Lori S.
Published: October 2006

As the economy evolves from manufacturing to services, it is important to understand whether the lessons learned in the manufacturing sector can be directly extrapolated to service supply chains. Unfortunately, the majority of existing supply chain research focuses exclusively on the manufacturing sector. To address this deficiency, this article compares the effect of traditional manufacturing‐oriented supply chain strategies on the operational and financial performance of firms in both service and manufacturing sectors. The results highlight similarities and differences between the two sectors — demonstrating that effective supply chain strategies in one sector may not be appropriate in the other sector. This suggests that practicing managers should identify appropriate benchmarks and competitive priorities before pursuing specific supply chain strategies. The insights provided by this research should help guide companies toward strategies that may positively affect their specific organization's operational and financial performance.
Supplier Diversity Effectiveness: Does Organizational Culture Really Matter?
Authors: Whitfield Gwendolyn , Landeros Robert
Published: October 2006

This study empirically examines the influence of organizational culture on supplier diversity. It examines the relationship between buyer behavior and culture using the Organizational Culture for Diversity Inventory (OCDI). The research assesses 12 business units within a heavy equipment manufacturer and uses confirmatory factor analysis to test an explanatory model of supplier diversity effectiveness. Results indicate achievement and affiliative culture styles are important to the effectiveness of supplier diversity. Moreover, in business units characterized by defensive or passive–defensive cultures, minority sourcing was lower. Conversely, the business units with constructive cultures for diversity had higher minority sourcing.
In vitro Characterization of Novel Peptide Inhibitors of Endomorphin‐degrading Enzymes in the Rat Brain
Authors: Fichna Jakub , Janecka Anna , Bailly Laetitia , Marsais Francis , Costentin Jean , Rego Jean‐Claude do
Published: October 2006

Endomorphins, endogenous μ‐opioid receptor ligands, have been shown to exert antinociceptive, antidepressant, anxiolytic, and neuromodulatory effects, as well as to influence cardiovascular, respiratory, and gastrointestinal systems. In the present study, we designed and synthesized a series of tetrapeptides and tripeptides (amides and peptide acids) of similar to endomorphins structure, but with low μ‐opioid receptor affinity, and tested them as possible inhibitors of endomorphin‐degrading enzymes. The obtained results indicate that the tripeptides Tyr‐Pro‐Ala‐NH2 and Tyr‐Pro‐Ala‐OH, which do not bind to the μ‐opioid receptors, are potent inhibitors of endomorphin‐degrading enzymes in the rat brain. We suggest that the in vivo administration of these novel analogs may enhance physiological effects of endogenous endomorphins by decreasing the rate of their enzymatic cleavage.
The prion protein: structural features and related toxic peptides
Authors: Ronga Luisa , Tizzano Barbara , Palladino Pasquale , Ragone Raffaele , Urso Emanuela , Maffia Michele , Ruvo Menotti , Benedetti Ettore , Rossi Filomena
Published: October 2006

Prion diseases are characterized by the conversion of the physiological cellular form of the prion protein (PrPC) into an insoluble, partially protease‐resistant abnormal scrapie form (PrPSc). PrPC is normally expressed in mammalian cell and is highly conserved among species, although its role in cellular function remains elusive. The conversion of PrPC to PrPSc parallels a conformational change of the polypeptide from a predominantly α‐helical to a highly β‐sheet secondary structure. The pathogenesis and molecular basis of the consequent nerve cell loss are not understood. Limited structural information is available on aggregate formation by this protein as the possible cause of these diseases and on its toxicity. This brief overview focuses on the large amount of structure‐activity studies based on the prion fragment approach, hinging on peptides derived from the unstructured N‐terminal and globular C‐terminal domains. It is well documented that most of the fragments with regular secondary structure, with the exception of helices 1 and 3, possess a high β‐sheet propensity and tendency to form β‐sheet‐like aggregates. In this context, helix 2 plays a crucial role because it is able to adopt both misfolded and partially helical conformation. However, only a few mutants are able to display its intrinsic neurotoxicity.