bluuebunny/crossref_metadata_2025 huggingface dataset:
The aged breast
Authors: Walker RA , Martin CV
Published: January 2007

There is a clear association between the development of breast cancer and increasing age, with 80% of cancers occurring in women more than 50 years of age and one‐third in women over 70 years. Following the menopause the breast undergoes involution, with the main changes affecting the terminal ductal lobular unit. There is an increase in oestrogen receptor alpha (ERα)‐positive cells, a decrease in proliferation but, in comparison to premenopausal breasts, a greater number of ERα‐proliferating cells. The breast cancers that occur in women ≥ 75 years are more likely to be ER‐positive, with a low growth rate and limited expression of HER‐2 and p53. It is proposed that uneven involution of the breast, the persistence of at‐risk lesions, the presence of ERα‐proliferating cells and local oestrogen metabolism in breast adipose tissue are factors in the development of breast cancers with a well‐differentiated phenotype. Copyright © 2007 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Microstructural evolution in the processing of auxetic microporous polymers
Authors: Alderson K. L. , Webber R. S. , Evans K. E.
Published: January 2007

Microstructural formation in auxetic microporous UHMWPE has been studied in detail using extensive mapping of the microstructure during its processing. To ease sectioning for microstructural examination, a sintering and extrusion route was used. The fibrillar microstructure was found to occur in both the radial and longitudinal directions. Fibril generation was also seen to occur prior to extrusion with enough fibrils of sufficient size to lead to auxetic behaviour. A mechanism for fibril generation is proposed which is based on surface melting of the particles and drawing out of the interparticle contact points by particle movement, which is not necessarily the result of extrusion through a die. These findings will aid in the understanding of processing of auxetic microporous polymers and in the drive to extending the range available to include other polymeric materials and different processing routes. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Anisotropic properties of mechanical characteristics and auxeticity of cubic crystalline media
Authors: Paszkiewicz T. , Wolski S.
Published: January 2007

Explicit expressions for inverse of Young's modulus E (n), inverse of shear modulus G (n, m), and Poisson's ratio ν (n, m) for cubic media are considered. All these characteristics of elastic media depend on components S11, S12 and S44 of the compliance tensor S, and on direction cosines of mutually perpendicular vectors n and m with fourfold symmetry axes. These characteristics are studied for all mechanically stable cubic materials for vectors n belonging to the irreducible body angle subtended by three cubic high symmetry directions [001], [111], and [110]. Regions of the stability triangle in which cubic elastic materials are completely auxetic, non‐auxetic, and auxetic are established. Several intermediate‐valence compounds belonging to the region of complete auxecity are indicated. The extreme properties of E–1, G–1 and ν established by Hayes and Shuvalov are confirmed. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The economics of integration of DVB‐S with terrestrial technologies and the role of dynamic bandwidth management
Authors: Katsianis Dimitris , Varoutas Dimitris , Apostolopoulou Vassiliki
Published: January 2007

This paper presents the technoeconomic aspects of network solutions based on integration of satellite and terrestrial, based on ADSL, WLAN and DVB‐T technologies, architectures. Following a discussion of the general deployment context, the business case framework is described in terms of areas served, services offered, tariffs, demand assumptions, as well as network architecture and dimensioning rules. The key cost items are presented and economic estimations are provided in the case of telecom operators, which integrate satellite bandwidth with terrestrial technologies in different area types. The evaluated business cases have shown that the satellite rental cost (airtime cost) level is one of the most critical parameter for the economic indicator of present value. Therefore, agreements with satellite operators for spectrum usage will give operators space for business opportunities and acceptable profit margins. In addition, dynamic bandwidth allocation schemes can exploit the aggregated traffic within satellite transmission, which can benefit satellite, telecom and cable operators offering entertainment on broadband business as well as new entrants in broadband business, equipment vendors, broadcasters and TV companies. Copyright © 2007 John Wiley & Sons, Ltd.
Syntheses, Characterizations, and Crystal Structures of Two New Organically Templated Borates
Authors: Pan Chun‐Yang , Wang Guo‐Ming , Zheng Shou‐Tian , Yang Guo‐Yu
Published: January 2007

Two new organically templated borates, [H2DAB][B7O9(OH)5]·2H2O (1) and [H2DAB][B7O10(OH)3] (2), have been synthesized under mild conditions in the presence of DAB acting as structure‐directing agent (DAB = 1,4‐diaminobutane). The structures were determined by single crystal X‐ray diffraction and further characterized by FTIR, elemental analysis, and thermogravimetric analysis. Both 1 and 2 crystallize in the same triclinic system, space group $P{\bar 1}$ (No. 2); 1: a = 8.238(4) Å, b = 8.348 (5) Å, c = 14.574(8) Å, a = 101.050(3)°, β = 92.313(7)°, γ = 112.694(5)°, V = 900.3(8) Å3, Z = 2; 2: a = 8.8769(3) Å, b = 9.3204(2) Å, c = 10.2204(5) Å, α = 74.474(2)°, β = 85.292(5)°, γ = 72.730(2)°, V = 778.01(5) Å3, Z = 2. The structure of 1 consists of [B7O9(OH)5]2− groups, which represents the first example of organically templated heptaborate. The structure exhibits interesting hydrogen‐bonded network formed by borate polyanion [B14O20(OH)6]4−, which can be regarded as being constructed from the dehydration of the FBBs in 1. The diprotonated organic amines are filled in the free space of the hydrogen‐bonded network and interact with the inorganic framework by extensive hydrogen bonds.
Are the Logical Foundations of Verifying Compiler Prototypes Matching user Expectations?
Authors: Chalin Patrice
Published: January 2007

The verifying compiler (VC) project proposals suggest that mainstream software developers are its targeted end-users. Like other software engineering efforts, the VC project success depends on appropriate end-user consultation. Industrial use of program assertions for the purpose of run-time assertion checking (RAC) is becoming commonplace. A likely next step on the path to VC adoption is the use of assertions in extended static checking (ESC), a fully automated form of static program verification (SPV). Unfortunately, all current VC prototypes supporting SPV, adopt a semantics which is unsound relative to the standard run-time interpretation of assertions. In this article, we report on the results of a survey in which we asked industrial developers what logical semantics they want program assertions to have, and whether consistency across RAC and SPV tools is important. Survey results indicate that developers are in favor of a semantics for assertions that is compatible with their current use in RAC.
Constructing the retail monument: the Parisian department store and its property, 1855–1914
Authors: PROCTOR ROBERT
Published: January 2007

By investigating the historical evidence for the Parisian department stores' campaigns of property acquisition in the nineteenth century, this article argues that not only was an increase in physical scale desired by managers to enlarge their businesses, but that the space of the store was deliberately moulded into a particular cultural form associated with the monument. The economic decisions involved in leasing and acquiring land, and the negotiation of the preferences for building form implied by building regulations, reveal more about how department stores constructed an image for themselves to embody the myth of a new order of commerce.
Adaptation and evaluation of the National Cancer Institute's Diet History Questionnaire and nutrient database for Canadian populations
Authors: Csizmadi Ilona , Kahle Lisa , Ullman Ruth , Dawe Ursula , Zimmerman Thea Palmer , Friedenreich Christine M , Bryant Heather , Subar Amy F
Published: January 2007

Background and objective

Despite assumed similarities in Canadian and US dietary habits, some differences in food availability and nutrient fortification exist. Food-frequency questionnaires designed for the USA may therefore not provide the most accurate estimates of dietary intake in Canadian populations. Hence, we undertook to evaluate and modify the National Cancer Institute's Diet History Questionnaire (DHQ) and nutrient database.

Methods

Of the foods queried on the DHQ, those most likely to differ in nutrient composition were identified. Where possible these foods were matched to comparable foods in the Canadian Nutrient File. Nutrient values were examined and modified to reflect the Canadian content of minerals (calcium, iron, zinc) and vitamins (A, C, D, thiamin, riboflavin, niacin, B6, folate and B12). DHQs completed by 13 181 Alberta Cohort Study participants aged 35–69 years were analysed to estimate nutrient intakes using the original US and modified versions of the DHQ databases. Misclassification of intake for meeting the Dietary Reference Intake (DRI) was determined following analysis with the US nutrient database.

Results

Twenty-five per cent of 2411 foods deemed most likely to differ in nutrient profile were subsequently modified for folate, 11% for vitamin D, 10% for calcium and riboflavin, and between 7 and 10% for the remaining nutrients of interest. Misclassification with respect to meeting the DRI varied but was highest for folate (7%) and vitamin A (7%) among men, and for vitamin D (7%) among women over 50 years of age.

Conclusion

Errors in nutrient intake estimates owing to differences in food fortification between the USA and Canada can be reduced in Canadian populations by using nutrient databases that reflect Canadian fortification practices.
Klinik des Morbus Parkinson
Authors: Ransmayr
Published: January 2007

Die klinischen Kriterien des Morbus Parkinson (Parkinson-Krankheit) sind eine Akinese in Kombination mit zumindest einem der folgenden Symptome: Tremor, in erster Linie asymmetrischer Ruhetremor, Rigor oder Störungen des Gleichgewichtes. Anamnestisch und klinisch sowie gegebenfalls zusatzdiagnostisch (vor allem durch bildgebende Diagnostik, wie CT oder MRT, oder nuklearmedizinisch, SPECT oder PET) sind symptomatische Formen eines Parkinsonsyndroms (z.B. vaskuläre Enzephalopathie, Normaldruckhydrocephalus) sowie medikamentöse oder toxische Ursachen oder atypische Parkinsonsyndrome auszuschließen. Bei M. Parkinson kommt es im Gegensatz zu atypischen und symptomatischen Parkinsonsyndromen während des gesamten Krankheitsverlaufes zu einem Ansprechen der motorischen Symptomatik auf L-Dopa oder Dopaminagonisten. Neben den motorischen Symptomen finden sich häufig vegetative Symptome, Schmerzen, Geruchsstörungen, Angst, Depression, kognitive Störungen und Demenz.
Schlaf und Bewegungsstörungen
Authors: Poryazova  , Bassetti
Published: January 2007

Die drei Zustände des Seins (Wachheit, NREM und REM Schlaf) gehen mit ausgeprägten neurophysiologischen und neurochemischen Änderungen im Gehirn einher. Diese Änderungen erklären das Vorhandensein von Bewegungsstörungen, die nur oder vorwiegend im Schlaf auftreten, und die Auswirkung des Schlafs auf Bewegungsstörungen. Die klinische Bedeutung motorischer Störungen im Schlaf ergibt sich aus verschiedenen Gründen: 1) hohe Frequenz (z.B. Restless-Legs-Syndrom (RLS)); 2) diagnostische Relevanz (z.B. REM-Schlafverhaltensstörung (RBD) als Erstmanifestation eines Morbus Parkinson); 3) diagnostische Unsicherheit (z.B. Parasomnien vs. nächtliche Epilepsien); 4) Assoziation mit Verletzungen (z.B. RBD, Schlafwandeln), Schlafbeeinträchtigung/Tagesschläfrigkeit (z.B. RLS) und psycho-soziale Belastung (z.B. Enuresis nocturna); 5) die Notwendigkeit einer spezifischen Behandlung (z.B. nächtliche Epilepsie, Stridor, RBD). Dieser Artikel gibt eine Übersicht über klinische Manifestationsformen, Pathophysiologie, Diagnosestellung und Behandlung von schlafbezogenen Bewegungsstörungen (z.B. RLS, Bruxismus), Parasomnien (z.B. Schlafwandeln, RBD), schlafbezogenen Epilepsien, und schlaf-assoziierten Manifestationen von Bewegungsstörungen (z.B. Morbus Parkinson, Multisystematrophie).
Renal mesangial cells: moving on sphingosine kinase‐1
Authors: Meyer zu Heringdorf D , Jakobs K H
Published: January 2007

Sphingosine kinase‐1 (SphK1) catalyses the phosphorylation of sphingosine to sphingosine‐1‐phosphate (S1P), which acts on at least five specific G‐protein‐coupled receptors and also intracellularly. SphK1 has been implicated in cell proliferation, cancer growth, chemoresistance, immune cell functions and cell migration. In this issue of the British Journal of Pharmacology, Klawitter et al. demonstrate that extracellular nucleotides stimulate the migration of renal mesangial cells. The nucleotides furthermore upregulated SphK1 expression and activity, and this enzyme was required for nucleotide‐induced migration. Together with previous findings, these data raise exciting questions: by which mechanism does SphK1 regulate migration in mesangial cells, how is the interplay of purinoceptors and S1P receptors organized in these cells, and how would SphK1‐deficient mice respond to kidney damage?

British Journal of Pharmacology (2007) 150, 255–257. doi:10.1038/sj.bjp.0706986
Dopamine Receptor Modulation of Hypoxic—Ischemic Neuronal Injury in Striatum of Newborn Piglets
Authors: Yang Zeng-Jin , Torbey Michel , Li Xiaoling , Bernardy Jennifer , Golden W Christopher , Martin Lee J , Koehler Raymond C
Published: January 2007

Dopamine receptors regulate glutamatergic neurotransmission and Na+,K+-ATPase via protein kinase A (PKA) and dopamine- and cAMP-regulated phosphoprotein of 32 kDa (DARPP-32)-dependent signaling. Consequently, dopamine receptor activation may modulate neonatal hypoxic–ischemic (H–I) neuronal damage in the selectively vulnerable putamen enriched with dopaminergic receptors. Piglets subjected to two durations of hypoxia followed by asphyxic cardiac arrest were treated with a D1-like (SCH23390) or D2-like (sulpiride) receptor antagonist. At 4 days of recovery from less severe H–I, the remaining viable neurons in putamen were 60% of control, but nearly completely salvaged by pretreatment with SCH23390 or sulpiride. After more severe H–I in which only 18% of neurons were viable, partial neuroprotection was seen with SCH23390 pretreatment (50%) and posttreatment (39%) and with sulpiride pretreatment (35%), but not with sulpiride posttreatment (24%). Dopamine was significantly elevated in microdialysis samples from putamen during asphyxia and the first 15 mins of reoxygenation. Pretreatment with SCH23390 or sulpiride largely attenuated the increased nitrotyrosine and the decreased Na+,K+-ATPase activity that occurred at 3 h after severe H–I. Pretreatment with SCH23390, but not sulpiride, also attenuated H–I-induced increases in PKA-dependent phosphorylation of Thr34 on DARPP-32, Ser943 on the α subunit of Na+,K+-ATPase, and Ser897 of the N-methyl-d-aspartate (NMDA) receptor NR1 subunit. These findings indicate that D1 and D2 dopamine receptor activation contribute to neuronal death in newborn putamen after H–I in association with increased protein nitration and decreased Na+,K+-ATPase activity. Furthermore, mechanisms of D1 receptor toxicity may involve DARPP-32-dependent phosphorylation of NMDA receptor NR1 and Na+,K+-ATPase.
Effect of grain charging dynamics on the wake potential of a moving test charge in a dusty plasma
Authors: Shafiq Muhammad , Raadu Michael A.
Published: January 2007

The response potential of a dusty (complex) plasma to a moving test charge strongly depends on its velocity. For a test charge moving with a velocity exceeding the dust-acoustic speed, a distinctive wake-field is produced trailing behind the test charge. Here the response to a fast moving test charge, when dispersion effects are small and the dust behaves as a cold plasma component, is considered. The effects of dynamical grain charging are included, and the cases with and without these effects are analyzed and compared. The plasma dielectric function is chosen assuming that all grains are of the same size and includes a response term for charging dynamics. The wake field potential is found either explicitly in terms of known functions or by using numerical methods for the integral expression. Maximum response is found on the wake cone with apex angle determined by the ratio between the dust acoustic velocity and the test charge velocity. The structure of the wake field stretches in the direction of the test charge velocity when this increases. The functional form of the field is given by separately changing the length scales parallel and perpendicular to the velocity. The potential on the axis gives an electric field close behind the test charge that can attract charges with the same sign. The grain charging dynamics leads to a spatial damping and a phase shift in the potential response.
Estimating the long-term residual value of zinc oxide for growing wheat in a sandy duplex soil
Authors: Brennan R. F. , Bolland M. D. A.
Published: January 2007

A long-term (17-year duration) field experiment was started on newly cleared zinc (Zn)-deficient sandy duplex soil (sand with lateritic ironstone gravel over clay) in south-western Australia that had never been fertilised to measure the residual value of Zn oxide for growing spring wheat (Triticum aestivum L.). When wheat was grown in the field experiment different amounts of Zn were applied once only to plots in 1983, 1984, 1986, 1990, 1992, 1996, 1997, and 2000. When the field experiment was terminated, we collected soil samples from the top 0.10 m of the field plots to do a glasshouse experiment reported here. In the pot experiment 5 amounts of Zn were applied to subsamples of soil collected from each plot of the field experiment. When a yield increase (response) to the freshly applied Zn was obtained in the pot study the maximum yield plateau for the relationship between yield of 54-day-old dried wheat shoots and the amount of Zn freshly applied was similar regardless of when and how much Zn was applied in the field. The amount of Zn freshly applied to soil in the pots required to produce 90% of the maximum yield of dried wheat shoots was determined for soil previously treated with no Zn or different amounts of Zn in different years in the field to provide DM90 values. The DM90 values were largest when no Zn was applied in the field, decreased as more Zn was applied in the field and, for each amount of Zn applied in the field, increased as the number of years from application of Zn increased. For soil treated with 0.5 and 1.0 kg Zn/ha in the field the relationship between DM90 values and the number of years since Zn was applied in the field was approximately linear. The projected number of years taken for soil previously treated with Zn in the field to require the same DM90 values as soil samples collected from the nil-Zn treatments in the field was 23 and 40 years for the 0.5 and 1.0 kg Zn/ha treatments, respectively.
In the pot experiment the Zn concentration in plant parts that was related to 90% of the total yield of dried wheat shoots (critical Zn concentration) was ~12 mg/kg for youngest mature growth (YMG) and 22 mg/kg for rest of shoots (ROS). The relationship between yield of dried wheat shoots and DTPA soil test Zn before sowing was similar for all the Zn treatments applied in both the field and pot studies, and the critical value was ~0.17 mg Zn/kg soil.
Lotus uliginosus (greater lotus) breeding line LUX97: a high seed producing, low condensed tannin population
Authors: Kelman W. M. , Blumenthal M. J. , O'Connor J. W. , Borchard P. A.
Published: January 2007

A Lotus uliginosus polycross population (LUX97) was developed from high seed producing Portuguese accessions and locally adapted New Zealand germplasms. Two cycles of selection for early flowering and low condensed tannin content were successful in producing a population with lower condensed tannin content than the Portuguese parents, while maintaining high seed production potential. Seed of this population will be stored at the CSIRO Plant Industry, Canberra.
How can a knowledge of the past help to conserve the future? Biodiversity conservation and the relevance of long-term ecological studies
Authors: Willis Katherine J , Araújo Miguel B , Bennett Keith D , Figueroa-Rangel Blanca , Froyd Cynthia A , Myers Norman
Published: January 2007

This paper evaluates how long-term records could and should be utilized in conservation policy and practice. Traditionally, there has been an extremely limited use of long-term ecological records (greater than 50 years) in biodiversity conservation. There are a number of reasons why such records tend to be discounted, including a perception of poor scale of resolution in both time and space, and the lack of accessibility of long temporal records to non-specialists. Probably more important, however, is the perception that even if suitable temporal records are available, their roles are purely descriptive, simply demonstrating what has occurred before in Earth's history, and are of little use in the actual practice of conservation. This paper asks why this is the case and whether there is a place for the temporal record in conservation management. Key conservation initiatives related to extinctions, identification of regions of greatest diversity/threat, climate change and biological invasions are addressed. Examples of how a temporal record can add information that is of direct practicable applicability to these issues are highlighted. These include (i) the identification of species at the end of their evolutionary lifespan and therefore most at risk from extinction, (ii) the setting of realistic goals and targets for conservation ‘hotspots’, and (iii) the identification of various management tools for the maintenance/restoration of a desired biological state. For climate change conservation strategies, the use of long-term ecological records in testing the predictive power of species envelope models is highlighted, along with the potential of fossil records to examine the impact of sea-level rise. It is also argued that a long-term perspective is essential for the management of biological invasions, not least in determining when an invasive is not an invasive. The paper concludes that often inclusion of a long-term ecological perspective can provide a more scientifically defensible basis for conservation decisions than the one based only on contemporary records. The pivotal issue of this paper is not whether long-term records are of interest to conservation biologists, but how they can actually be utilized in conservation practice and policy.
Introduction of Caged Peptide/Protein into Cells Using Microinjection: Figure 1.
Authors: Humphrey David , Rajfur Zenon , Imperiali Barbara , Marriott Gerald , Roy Partha , Jacobson Ken
Published: January 2007

INTRODUCTION

Activation and inactivation of proteins using photoactivation of caged peptides or proteins offer insights into cellular dynamics not achievable using genetic means. The ability to selectively alter the activity of a specific protein at a defined time and location inside a cell allows the correlation of changes in protein activity and cellular behavior. A caged compound, peptide, or protein is prepared by covalently linking it to a photolabile, protecting group via a limited number of critical functional groups in the biomolecules. Under carefully defined conditions, a brief irradiation with UV light (320-400 nm) can lead to an intramolecular photoisomerization reaction that induces the cleavage of the chemical bond between the cage group and the unmodified, biologically active species. The following protocol uses a semiautomated microinjection system (Eppendorf FemtoJet Microinjector along with the Eppendorf InjectMan) for the introduction of caged compounds into cells. Unlike the bead-loading approach, this technique allows the investigator to choose which cells are targeted.
Preparation of Arabidopsis Chloroplasts
Authors: Mach Jennifer
Published: January 2007

INTRODUCTION

The functions of most Arabidopsis genes cannot be understood simply by studying the expression patterns of their mRNAs. The level of a protein may not be closely correlated with the level of the corresponding mRNA, or a protein may need to be modified to be active. Furthermore, the function of proteins often depends on specific subcellular localization, so knowledge of this can exclude some hypotheses about possible function. For example, if a protein is found exclusively in the cytoplasm, it is unlikely to function as a transcription factor. It is therefore often desirable to prepare subcellular fractions, either to localize proteins or to improve the sensitivity of protein detection. This procedure describes the enrichment of chloroplasts from Arabidopsis.
Preparation of Arabidopsis Mitochondria
Authors: Mach Jennifer
Published: January 2007

INTRODUCTION

The functions of most Arabidopsis genes cannot be understood simply by studying the expression patterns of their mRNAs. The level of a protein may not be closely correlated with the level of the corresponding mRNA, or a protein may need to be modified to be active. Furthermore, the function of proteins often depends on specific subcellular localization, thus knowledge of this can exclude some hypotheses about possible function. For example, if a protein is found exclusively in the cytoplasm, it is unlikely to function as a transcription factor. It is therefore often desirable to prepare subcellular fractions, either to localize proteins or to improve the sensitivity of protein detection. This procedure describes the enrichment of mitochondria from Arabidopsis.
Sectioning Mouse Embryos
Authors: Nagy Andras , Gertsenstein Marina , Vintersten Kristina , Behringer Richard
Published: January 2007

INTRODUCTION

This protocol provides methods and tips for sectioning mouse embryos and transferring the sections to a microscope slide.
Negative Beliefs as a Moderator of the Intention–Behavior Relationship: Decisions to Use Performance‐Enhancing Substances
Authors: Dodge Tonya , Jaccard James J.
Published: January 2007

The theory of reasoned action framework was used to examine performance‐enhancing substance use among a sample of college athletes in a prospective longitudinal design. Results indicate that attitudes and subjective norms predicted intention to use the substances, and these intentions predicted actual substance use 6 weeks later. A statistically significant interaction emerged between negative beliefs and intentions predicting behavior such that as negative beliefs grew increasingly negative, the intention–behavior relationship became stronger. Practical and theoretical implications of the influence of negative information on the intention–behavior relationship are discussed.
Flexibility in macro‐scripts for computer‐supported collaborative learning
Authors: Dillenbourg P. , Tchounikine P.
Published: January 2007

Abstract
In the field of computer‐supported collaborative learning (CSCL), scripts are designed to support collaboration among distant learners or co‐present learners whose interactions are (at least partially) mediated by a computer. The rationale of scripts is to structure collaborative learning processes in order to trigger group interactions that may be rare in free collaboration. Fixing the degree of coercion is a delicate design choice: too rigid scripts would spoil the richness of collaborative interactions; too flexible scripts would fail to induce the targeted interactions. Because of the unpredictability of how scripts will be enacted, both the teacher and the students must be allowed to modify some script features. In this article we propose a conceptual analysis of this notion of flexibility, arguing for a dissociation of constraints that are intrinsic to the pedagogical design of the script and constraints induced by the technology or contextual factors. This difference sets up the limits of flexibility both for the teacher and for the students and provides specification for the computational design. This analysis leads to the conclusion that the operationalization of CSCL scripts should be addressed by implementing script engines handling multiple representations of the script: the script to be executed, the emergent organization of teams, the set of intrinsic and extrinsic constraints and the visual representation of the script for students and teachers.
Gender differences in computerised and conventional educational tests
Authors: Horne J.
Published: January 2007

Abstract
Research has demonstrated girls to outperform boys on conventional literacy tests. The present studies concern gender differences on computerised educational tests. Seventy‐one children were tested using LASS Secondary and a set of seven conventional measures. No significant gender differences were found on any of the LASS Secondary modules, although females did outperform males on a conventional spelling test. A further 126 pupils were tested on computerised and paper versions of the LASS Secondary reading, spelling and reasoning modules. No gender differences were found on the computerised versions, but there were significant differences on the paper versions of the reading and spelling modules favouring females. In a third study, 45 children were administered computerised and paper versions of the LASS Junior reading and spelling modules. There were no significant differences on the computerised modules, but girls performed significantly higher than boys on the paper version of the spelling module. It is possible that computerised assessment does not detect the established gender effect due to differences between males and females in motivation, computer experience and competitiveness. Further large‐scale studies are necessary to confirm these findings.
Phosphoenolpyruvate carboxykinase in developing pea seeds is associated with tissues involved in solute transport and is nitrogen‐responsive
Authors: DELGADO‐ALVARADO ADRIANA , WALKER ROBERT P. , LEEGOOD RICHARD C.
Published: January 2007

The aim of this work was to investigate the occurrence of phosphoenolpyruvate carboxykinase (PEPCK) in developing pea (Pisum sativum) seeds in relation to their nitrogen supply. PEPCK was present throughout development, with the peak of PEPCK protein and activity in the seed coat and cotyledons preceding protein accumulation in the cotyledons. It showed a different developmental pattern from enzymes involved in amino acid metabolism (phosphoenolpyruvate carboxylase, glutamine synthetase and glutamate dehydrogenase). Immunolocalization showed that PEPCK was present in parts of the developing seed that are involved in the transport and metabolism of assimilates. Early in development, it was associated with the inner integument of the ovule, the endospermic cytoplasm and the outer cells of the embryo. In the middle of development, around the peak of activity, PEPCK was abundant at the outer surface of the developing cotyledons, in the embryonic axis and in the vasculature of the seed coat. Later in development, PEPCK was associated with the embryonic leaf primordia and meristem and cortex of the radicle. PEPCK protein was strongly induced in vitro in the seed coat by nitrate, ammonium and asparagine, in the cotyledons by asparagine and in planta by the supply of nitrogen, which led to an increase in asparagine secretion by empty seed coats. It is suggested that PEPCK is involved in the metabolism of nitrogenous solutes in developing pea seeds.
Disability following kidney transplantation: the link to medication coverage
Authors: Slakey D.P. , Rosner M.
Published: January 2007

Abstract:  There is no uniformity regarding patient disability following kidney transplantation. Given improved results of patient and graft survival, and the link between insurance, medication coverage and disability, efforts must be made to define disability after a successful transplant. We conducted an individual questioner study of kidney transplant patients to determine factors relating to patient‐perceived disability. Seventy patients participated in the study. Patient perception of disability did not correlate with education or ethnicity. Most patients believed they were disabled on dialysis and this did not change following transplantation. While 42 (60%) of the patients felt that they could work, either full‐time or part‐time, only 20 (28%) were actually working or in school. Most patients believe that working will eliminate disability status and, therefore, insurance and medication coverage. Patients considered disability more related to their status as a kidney transplant patient than any specific physical limitations. The link, whether real or perceived, between ‘disability’ and immunosuppressive medication coverage is a significant barrier for many patients. The transplant community must reach some degree of consensus regarding post‐transplant activity restrictions. The transplant community needs to find a way to take an active role in post‐transplant education and employment.
Steroids in intestinal transplantation
Authors: Dazzi A. , Lauro A. , Zanfi C. , Ercolani G. , Vivarelli M. , Grazi G.L. , Cescon M. , Di Simone M. , D'Errico A. , Lazzarotto T. , Faenza S. , Pironi L. , Pinna A.D.
Published: January 2007

Abstract:  Background:  Recently, new immunosuppressive protocols after intestinal transplantation have been proposed to avoid steroids use and their adverse effects. We evaluated the impact of steroids on survival and post‐transplant complications in our experience.

Patient and methods:  In our retrospective study we considered the mean daily dosage of steroids received by 25 patients after intestinal/multivisceral transplantation (minimal follow‐up was six months). We analyzed graft and patient survival rates, correlation with rejection and infectious episodes and steroids side effects.

Results:  After a mean follow‐up of three yr, we did not find any significant difference in steroid doses between our immunosuppressive protocols. Patients with a mean dosage of prednisone higher than 20 mg/d experienced a lower graft (p = 0.009) and patient (p = 0.02) survival rate. The side effects of steroids after transplant were similar. Infections were more frequent during steroids administration (p = 0.04).

Discussion and conclusion:  Steroids therapy may be useful to treat acute rejection, but in our experience high steroids regimen did not improve graft and patient survival, increasing infectious rate. We assumed that high dose of steroids can be avoided as maintenance therapy, except in selected cases.
How many cases of Type 2 diabetes mellitus are due to being overweight in middle age? Evidence from the Midspan prospective cohort studies using mention of diabetes mellitus on hospital discharge or death records
Authors: Hart C. L. , Hole D. J. , Lawlor D. A. , Davey Smith G.
Published: January 2007

Aims  To relate body mass index (BMI) in middle age to development of diabetes mellitus.

Methods  Participants were 6927 men and 8227 women from the Renfrew/Paisley general population study and 3993 men from the Collaborative occupational study. They were aged 45–64 years and did not have reported diabetes mellitus. Cases who developed diabetes mellitus, identified from acute hospital discharge data and from death certificates in the period from screening in 1970–1976 to 31 March 2004, were related to BMI at screening.

Results  Of Renfrew/Paisley study men 5.4%, 4.8% of women and 5% of Collaborative study men developed diabetes mellitus. Odds ratios for diabetes mellitus were higher in the overweight group (BMI 25 to < 30 kg/m2) than in the normal weight group (BMI 18.5 to < 25 kg/m2) and highest in the obese group (BMI ≥ 30 kg/m2). Compared with the normal weight group, age‐adjusted odds ratios for overweight and obese Renfrew/Paisley men were 2.73 [95% confidence interval (CI) 2.05, 3.64] and 7.26 (95% CI 5.26, 10.04), respectively. Further subdividing the normal, overweight and obese groups showed increasing odds ratios with increasing BMI, even at the higher normal level. Assuming a causal relation, around 60% of cases of diabetes could have been prevented if everyone had been of normal weight.

Conclusions  Overweight and obesity account for a major proportion of diabetes mellitus, as identified from hospital discharge and death records. With recent increases in the prevalence of overweight, the burden of disease related to diabetes mellitus is likely to increase markedly. Primordial prevention of obesity would be a major strategy for reducing the incidence of diabetes mellitus in populations.
Incipient cardiovascular autonomic imbalance revealed by wavelet analysis of heart rate variability in Type 2 diabetic patients
Authors: Urbančič‐Rovan V. , Meglič B. , Stefanovska A. , Bernjak A. , Ažman‐Juvan K. , Kocijančič A.
Published: January 2007

Aim  Incipient cardiovascular autonomic imbalance is not readily diagnosed by conventional methods. Spectral analysis of heart rate variability (HRV) by wavelet transform (WT) was used to measure cardiovascular autonomic function in patients with Type 2 diabetes.

Methods  Thirty‐two diabetic patients without (D), 26 with cardiovascular autonomic neuropathy (DAN) and 72 control subjects (C) participated. A 30‐min HRV time series was analysed by wavelet transformation and four characteristic frequency intervals were defined: I (0.0095–0.021 Hz), II (0.021–0.052 Hz), III (0.052–0.145 Hz) and IV (0.145–0.6 Hz).

Results  When compared with C, in both D and DAN the normalized power and amplitude of interval II were increased and of interval IV decreased, resulting in a significantly higher II/IV ratio. Furthermore, in DAN the normalized power and amplitude of interval I were increased and of interval III decreased when compared with the D and C groups. The diabetic patients were divided in two equal subgroups according to HbA1c < 8.0% and ≥ 8.0%. In the subgroup with HbA1c≥ 8.0%, normalized power in interval II was significantly higher and in interval IV significantly lower than in the subgroup with HbA1c < 8.0%. In D, but not in DAN patients prescribed ACE inhibitors, the absolute amplitude and power of oscillations were significantly higher than in patients not taking ACE inhibitor therapy.

Conclusions  Patients with diabetes have increased sympathetic and decreased parasympathetic cardiac activity regardless of the presence of autonomic neuropathy. Glycaemic control and treatment with ACE inhibitors may favourably influence HRV in diabetic patients without autonomic neuropathy.
All‐cause and cardiovascular mortality in diabetic subjects increases significantly with reduced estimated glomerular filtration rate (eGFR): 10 years’ data from the South Tees Diabetes Mortality study
Authors: Nag S. , Bilous R. , Kelly W. , Jones S. , Roper N. , Connolly V.
Published: January 2007

Aims  To investigate the association between estimated glomerular filtration rate (eGFR) and total and cardiovascular mortality in a population‐based cohort of diabetic subjects.

Methods  A longitudinal study using a population‐based district diabetes register comprising 3288 subjects in South Tees, UK. The eGFR was calculated using the Modification of Diet in Renal Disease (MDRD) study equation. Patients were stratified by baseline eGFR into five stages as per the National Kidney Foundation guidelines: Stage 1, eGFR > 90; Stage 2, eGFR 60–89; Stage 3, eGFR 30–59; Stage 4, eGFR 15–29; and Stage 5, eGFR < 15 ml/min per 1.73 m2. Main outcome was all‐cause and cardiovascular mortality between 1 January 1994 and 31 July 2004.

Results  At baseline, mean age (58.4 years) differed between groups. Persons with lower eGFR were older (P < 0.001). Thirty‐six percent (n = 1193, males 56%) had died by 10 years (cardiovascular cause in 60%). Median follow‐up was 10.5 years amounting to 28 342 person years. Stages 4 and 5 (eGFR ≤ 29 ml/min per 1.73 m2) were amalgamated for mortality analysis. Total and cardiovascular mortality increased with reduced eGFR. Adjusted hazard ratios (HR) [95% confidence interval (CI)] for all‐cause mortality comparing groups 2 and 3, and 4 and 5 combined with group 1 were 1.28 (1.02, 1.60), 2.58 (2.05, 3.25) and 6.42 (4.25, 9.71), respectively. Adjusted HRs (95% CI) for mortality due to circulatory disease comparing groups 2 and 3, and 4 and 5 combined with group 1 were 1.50 (1.10, 2.06), 3.32 (2.41, 4.58) and 7.99 (4.69, 13.62), respectively.

Conclusions  In diabetic subjects, mortality increases significantly with reduced GFR. Low eGFR identifies patients at high risk of cardiovascular mortality who should be targeted for aggressive risk factor modification.
Telecommunications Investment in Africa: Implications of US Reform of the International Settlement Rate System*
Authors: Gyimah‐Brempong Kwabena , Karikari John Agyei
Published: January 2007

Abstract:  This paper investigates the possible effects of the US reform of the international settlement rate system on telecommunications investment in Africa. We estimate a telecommunications investment equation using a panel data of 51 African countries during the 1991–2003 period and find that settlement payments have significantly positive effects on telecommunications investment in African countries. A 10 percent increase in settlement payment, on average, increases the telecommunications investment expenditure to GDP ratio by 3.4 percent over a three‐year period. Using previously calculated revenue loss from the US reform, our estimates suggest that African countries stand to lose between 4.4 to 11 percentage points of their telecommunications investment in the medium run and with it, possible decreases in income growth rate. However, we argue that African countries can counter the effects of this revenue loss by increasing the efficiency of telecommunications investment through appropriate market restructuring, including the promotion of competition and privatization.
Universalism versus targeting: The vulnerability of social insurance and means‐tested minimum income protection in 18 countries, 1990‐2002
Authors: Nelson Kenneth
Published: January 2007

The stagnation and retrenchment of social policies in recent decades raise considerable interest and concern in writings on the welfare state. This study examines differences in the development of means‐tested benefits and social insurance provisions. Questions relating to the measurement of policy retrenchment and the vulnerability of social benefits are addressed. Two conflicting hypotheses are discerned: one stating that the development of means‐tested benefits resembles that of social insurance; and another more recent one claiming that the evolution of means‐tested benefits follows a unique pattern. The empirical analyses are based on institutional data on the level of social benefits. It is shown that social insurance stands a better chance of surviving periods of retrenchment and that the greater vulnerability of means‐tested benefits is related to the organization of social insurance provisions.
Tentative evaluation of the impact of public transfers on the dynamics of poverty: The case of Russia
Authors: Clément Matthieu
Published: January 2007

The aim of this article is to offer a dynamic impact analysis of the system of transfers in Russia, based on a comparison of indicators of well‐being measured before and after state intervention. We shall begin by assessing the impact of public transfers on different forms of poverty and demonstrate that, while the system is seeing a fall in chronic and transitional poverty, there is very little movement between categories. We shall then evaluate the capacity of the system to keep non‐poor households from falling into poverty (protection) and to help poor households escape poverty (promotion). Several studies suggest that the Russian system of transfers is well suited to protection but has proved incapable of attaining the goal of promotion. In other words, in its current form it cannot claim to be an effective tool to combat long‐term poverty.
Resource Dependency and Political Opportunity: Explaining the Transformation from Excluded Political Opposition Parties to Human Rights Organizations in Post-Communist Uzbekistan
Authors: Grodsky Brian
Published: January 2007

While there is significant anecdotal evidence that excluded political opposition parties in repressive states adopt the form of human rights organizations, there is little systematic research into this phenomenon. What does exist tends to be descriptive rather than theoretical in nature. This paper draws from collective action and resource mobilization literatures, arguing that excluded political elites respond to repression by searching for political opportunities both domestically and internationally, and then transform their organizations into units better able to take advantage of those opportunities. The politics of external funding push these organizations towards a human rights and democratization orientation. The article evaluates this argument through an analysis of human rights movements in politically repressive, post-Communist Uzbekistan and considers the impact of this phenomenon on democratization and civil society development.
The Many Faces of H89: A Review
Authors: Lochner A. , Moolman J. A.
Published: January 2007

H89 is marketed as a selective and potent inhibitor of protein kinase A (PKA). Since its discovery, it has been used extensively for evaluation of the role of PKA in the heart, osteoblasts, hepatocytes, smooth muscle cells, neuronal tissue, epithelial cells, etc. Despite the frequent use of H89, its mode of specific inhibition of PKA is still not completely understood. It has also been shown that H89 inhibits at least 8 other kinases, while having a relatively large number of PKA‐independent effects which may seriously compromise interpretation of data.

Thus, while recognizing its kinase inhibiting properties, it is advised that H89 should not be used as the single source of evidence of PKA involvement. H‐89 should be used in conjunction with other PKA inhibitors, such as Rp‐cAMPS or PKA analogs.