bluuebunny/crossref_metadata_2025 huggingface dataset:
The Trade Policy Jungle: A Survival Guide for Academic Economists
Authors: Evenett Simon J.
Published: April 2008

The rules of the trade policy arena differ from those in academia. How can an economic researcher survive, let alone thrive, in what may appear to be a trade policy jungle? The purpose of this paper is not just to offer guidance in this respect but also to think through the factors that determine the supply and demand for timely, relevant, policy‐relevant insights into commercial policy matters. Understanding the latter provides much of the rationale for the former. Advice follows analysis, as it should do. Economic researchers have certain advantages that they can make immediate use of in the jungle and some baggage that they would do well to shed.
Recent Regional Agreements: Why So Many, Why So Much Variance in Form, Why Coming So Fast, and Where Are They Headed?
Authors: Whalley John
Published: April 2008

Recent years have seen a sharp growth in the number of regional agreements both concluded and under negotiation. This paper attempts to document and discuss this growth focusing on US, EU, Chinese, Indian and other agreements. The form, coverage and content of these agreements vary considerably from case to case. The paper asks why so many, why the variation in form, and why the recent acceleration. Implications for the trading system are discussed in a final section.
Pensions and Intergenerational Risk‐sharing in General Equilibrium
Authors: BEETSMA ROEL M. W. J. , LANS BOVENBERG A.
Published: April 2008

We investigate intergenerational risk‐sharing in two‐pillar pension systems with a pay‐as‐you‐go pillar and a funded pillar. The funded pension pillar can be either defined contribution or defined benefit. Only a defined‐benefit scheme with an appropriate investment policy establishes optimal intergenerational risk‐sharing. We show how the pension system affects capital markets in general and the equity premium in particular.
Robust International Comparisons of Distributions of Disposable Income and Regional Public Goods
Authors: GRAVEL NICOLAS , MOYES PATRICK , TARROUX BENOÎT
Published: April 2008

The paper provides robust normative comparisons of 12 OECD countries based on their distributions of disposable income and access to two regional public goods: infant mortality and pupil–teacher ratios at public schools. Comparisons are performed using two and three‐dimensional dominance criteria that coincide with the unanimity of utilitarian judgments taken over specific classes of utility functions. The criteria succeed in ranking conclusively about 30% of all possible comparisons in the two‐dimensional case, compared with 67% for one‐dimensional income‐based comparisons and 6% for three‐dimensional ones. Introducing local public goods seems to worsen the relative standing of Anglo‐Saxon countries.
PROGRESS REPORT, CALENDAR YEAR 1970: HARVARD BUSINESS SCHOOL MULTINATIONAL ENTERPRISE PROJECT
Authors: Vesnon Raymond
Published: April 2008

This is the fifth annual progress report relating to the study of multinational enterprises at the Harvard Business School. This report is designed to provide an up‐to‐date picture of the state of the project without reference to prior annual reports.

The project is thought of as the opening phase of an extended effort to understand certain aspects of the operations of the multinational enterprise. The product associated with the project when completed will consist of fourteen doctoral theses; about fifty articles in various journals and publications; and seven books. Among these books is one that synthesizes and extends the work embodied in the other publications of the project. The synthesizing volume is scheduled for publication in September 1971.

The various publications are intended to illuminate the problems of the multinational enterprise in the fields of finance, organization, and business‐government relationships. At the same time, new light is being shed upon the role of multinational enterprises in international trade, capital movements, and technological transfers. The synthesizing volume also tries to relate the development of multinational enterprises to the structure of nation states, exploring where conflict may exist and adaptation may develop.

Another major by‐product of the multinational enterprise study, already in existence, is an historical file tracing the development of some 11,000 foreign subsidiaries of U.S. parent companies from 1900 to 1967. These subsidiaries account for about 80 per cent of U.S. foreign direct investment. The file, which is being used extensively for various aspects of the multinational enterprise study, is also being made available to other researchers, both at the Harvard Business School and at other institutions, within the limits imposed by confidentiality commitments.
HARMONIZATION OF ECONOMIC POLICIES IN CUSTOMS UNIONS: THE ANDEAN GROUP*
Authors: Morawetz David
Published: April 2008

The payer examines the conditions under which the formation of a customs union or free trade area makes some degree of harmonization of economic policies desirable, and the extent to which these conditions apply in the Andean Group customs union recently formed by Bolivia, Chile, Colombia, Ecuador and Peru. The policies analysed are those concerning tariffs, export subsidies, indirect taxes, exchange rates, planning and macro scabilization, intra‐union factor movements, foreign capital, and currency unification. Different conclusions as to the desirability of harmonizing the policies are derived depending on the specific type of harmonization considered and the assumptions which are made concerning concurrent harmonization of other policies.
Clinical Implications of Attachment Concepts: Retrospect and Prospect *
Authors: Rutter Michael
Published: April 2008

Abstract The key features of attachment theory are summarized and the unresolved questions considered in terms of a behavioural control system, measurement of attachment security, qualities of attachment, the role of temperament, transformation of a dyadic quality into an individual characteristic, internal working models, manifestations of attachment post infancy, how one relationship affects another relationship, boundaries of attachment, associations with later functioning, the role of parenting qualities and patterns of caregiving, adaptive value of secure attachment, and disorders of attachment. The clinical implications are discussed in terms of: the need to reject tine traditional psychoanalytic theories of development, the patterns of residential care for children, the provision of child care, the assessment of parenting, the effects of parental divorce and family break‐up, “maternal bonding” to infants, psychotherapy and disorders of attachment.
Mother‐Child Interaction and the Cognitive and Behavioural Development of Four‐Year‐Old Children With Poor Growth
Authors: Puckering C. , Pickles A. , Skuse D. , Heptinstall E. , Dowdney L. , Zur‐Szpiro S.
Published: April 2008

Abstract A whole population inner‐city survey identified 23 stunted, otherwise healthy, children with persistently poor growth from infancy to 4 years. Their cognitive development was significantly retarded relative to a matched comparison group. Unstructured home observations were used to create transcripts of verbal and nonverbal mother‐child interactions. In both groups child behavioural adjustment was linked to maternal negativity, and cognitive performance was correlated with quality of stimulation. The developmental delay associated with chronic failure to thrive appeared more likely to arise from other influences, perhaps a previous biological insult, than to contemporaneous parenting practices.
The Adolescent Outcomes of Adoption: A 16‐Year Longitudinal Study
Authors: Fergusson David M. , Lynskey Michael , Horwood L. John
Published: April 2008

Abstract The childhood history and adolescent adjustment of children placed in adoptive, biological two parent and single parent families were examined in a birth cohort of 1265 New Zealand children studied to the age of 16 years. This study suggested that children who entered adoptive families were advantaged throughout childhood in a number of areas including childhood experiences, standards of health care, family material conditions, family stability and mother/child interaction. However, the environmental advantages experienced by children who entered adoptive families were not directly reflected in the pattern of adolescent adjustment of this group. In particular, children placed in adoptive families had rates of externalising behaviours (including conduct disorders, juvenile offending and substance use behaviours) that were significantly higher than children reared in biological two parent families but somewhat lower than those of children who entered single parent families at birth.
Extremity of Externalizing Behavior and Young Adult Outcomes
Authors: Farmer Elizabeth M. Z.
Published: April 2008

Abstract Data from the National Child Development Study were used to explore the relationship between extremity of externalizing behavior problems during childhood and employment‐related outcomes in young adulthood. Analyses focused on four heuristic dimensions of extremity (age at onset, density, persistence, and pervasiveness) and three outcomes (school‐leaving age, level of qualifications at labor force entry, and social class of job al age 23). Persistence was associated with the most substantial deficits across all outcomes, and temporal proximity was more influential than early onset. The data suggest that school‐based and home‐based situational behavior problems should not be combined into a single nonpervasive category.
Self‐Control in Boys with Attention Deficit Hyperactivity Disorder: Effects of Added Stimulation and Time
Authors: Schweitzer Julie B. , Sulzer‐Azaroff Beth
Published: April 2008

Abstract Preference for larger‐delayed versus more immediate‐smaller rewards was studied in 5‐ and 6‐year‐old typical boys with Attention Deficit Hyperactivity Disorder (ADHD) in a repeated measure design. The effect of adding stimulation on preference also was studied. Boys with ADHD chose delayed‐larger rewards significantly less than did typical boys. Adding stimulation reduced motoric behavior, but did not affect choice. As rates of motoric activity increased in boys with ADHD, their preference for delayed, larger rewards decreased over time. These Findings argue for the external validity of choice tasks in the study of ADHD.
An Eight‐Year Prospective Study of Older Boys Placed in Permanent Substitute Families: A Research Note
Authors: Rushton Alan , Treseder Judy , Quinton David
Published: April 2008

Abstract The psychosocial development of 16 boys placed in permanent substitute families between the ages of 5 and 9 was examined at 1, 12, 60 and 96 months into placement. Conduct and emotional problems fell significantly over the first year but relationship difficulties and overactivity changed little. There was no significant change beyond 12 months. By 8 years, 19% of placements had disrupted and 15% of the remainder had a poor outcome. The level of preptacement adversity predicted poor or disrupted outcomes, but outcomes for those with high adversity were hotter when parenting was very positive.
Sustained Attention, Activation and MPH in ADHD: A Research Note
Authors: van der Meere Jaap , Shalev Ruth , Börger Norbert , Gross‐Tsur Varda
Published: April 2008

Abstract Sustained attention was studied in children with attention deficit hyperactivity disorder (ADHD) and normal controls using a continuous performance task with slow presentation of stimuli and carried out with an experimenter‐present and absent condition. Children with ADHD were slower than controls, with performance deteriorating over lime, particularly in the experimenter‐absent condition. Both the slowness and deterioration normalized when the children received MPH. Hence the rate of stimuli presentation and the presence or absence of experimenter are both crucial factors in the performance of children with ADHD. MPH is able to ameliorate the performance decrement seen tinder these conditions.
Sexual size dimorphism of the tongue in a North American pitviper
Authors: Smith C. F. , Schwenk K. , Earley R. L. , Schuett G. W.
Published: April 2008

Sexual dimorphisms – phenotypic dissimilarities between the sexes – are common and widespread among plants and animals, and classical examples include differences in body size, colour, shape, ornamentation and behaviour. In general, sexual dimorphisms are hypothesized to evolve by way of sexual selection acting on one sex through priority‐of‐access for sexual partners via mate choice and/or intra‐sexual competition. In snakes, males are the mate‐searching sex and one form of sexual selection involves male–male competition in locating females by following pheromone trails using their forked tongues, the structure used to sample environmental chemicals for transduction in the vomeronasal chemosensory system (VNS). Based on several lines of empirical evidence, increased tongue forking (bifurcation) in snakes (and some lizard taxa) appears to enhance chemical trail‐following abilities through tropotaxis (the simultaneous comparison of stimulus intensities on two sides of the body) and thus aids in prey location and mate searching in males. We predicted that male copperheads, Agkistrodon contortrix, a North American pitviper, should have more deeply forked tongues than females owing to male–male competition for priority‐of‐access to widely dispersed females during the mating seasons. We examined formalin‐fixed, ethanol‐preserved museum specimens of adult A. contortrix for sexual size dimorphism (SSD) of the tongue. Tongue dimensions showed differences indicative of SSD, and the degree of bifurcation (i.e. mean tine length) was significantly greater in males. Various structures of the VNS and associated regions (e.g. muscles) in some vertebrate taxa show sexual dimorphism, but our study is the first to document dimorphism in the tongue of a tetrapod vertebrate.
What limits male range sizes at different population densities? Evidence from three populations of water voles
Authors: Moorhouse T. P. , Macdonald D. W.
Published: April 2008

In many mammalian species, females compete with each other for food and space to raise offspring, while males compete with each other for access to females. Few studies have examined the factors which limit male range sizes or the degree of overlap between male ranges. We deduced four possible responses of the range ‐sizes of non‐territorial male small mammals to increasing population density and/or levels of forage abundance. These were: (1) male range sizes might remain the same irrespective of population density; (2) at high population densities males may become territorial, and their ranges small and non‐overlapping; (3) at high forage abundance/population densities, males' ranges may become smaller but remain intra‐sexually overlapping; (4) at high forage abundance, male range sizes may increase. We examined the relationship between population density, range lengths and range overlaps and body weights of both sexes in a comparative study of three populations of water voles Arvicola terrestris. Male range sizes were smaller at higher population densities, but their ranges remained both inter‐ and intra‐sexually overlapping. Heavier males had larger ranges than did lighter males at all sites. These results comply with what would be expected if male range sizes were at least partially restricted by the number of ranges of other individuals with which they overlapped. Although we could not discount the hypothesis that forage abundance may also have had a direct effect on male range sizes, our results implied that male range sizes were at least partially determined by social factors.
LSCF Nanopowder from Cellulose–Glycine‐Nitrate Process and its Application in Intermediate‐Temperature Solid‐Oxide Fuel Cells
Authors: Zhou Wei , Shao Zongping , Ran Ran , Gu Hongxia , Jin Wanqin , Xu Nanping
Published: April 2008

Nanostructured La0.6Sr0.4Co0.2Fe0.8O3−δ (LSCF) oxide powder was synthesized by a facile autocombustion process based on a modified glycine‐nitrate process (GNP) using cellulose fiber as micro‐reactor. As compared with the normal GNP, this novel process allows the combustion to proceed in a much more environmentally friendly and controllable way. The resulted powder is nanocrystallized with particle size of only 15–20 nm as observed by transmission electron microscopy examination. More importantly, because the metal ions could disperse homogenously in cellulose–GN precursor, SrCO3 impurity was effectively suppressed. The concentrations of SrCO3 impurity in LSCF products were determined by carbon dioxide–temperature‐programmed desorption technique, which decreased to as low as 1.3 wt% from cellulose–GN process, in contrast to 4.3 wt% from the normal GNP. These features resulted in the attractive improvement of its cathode performance in solid‐oxide fuel cells (SOFCs). The interfacial resistances of only ∼0.70 and ∼0.36 Ω·cm2 at 600° and 650°C under air, respectively, were observed, which was about two times better than the LSCF cathode derived from the normal GNP. A peak power density of ∼346 mW/cm2 was achieved at 600°C with cellulose–GN‐derived LSCF cathode based on thin‐film Sm0.2Ce0.8O1.9 electrolyte SOFC using 3% humidified H2 as the fuel.
Deposition Mechanism for Chemical Vapor Deposition of Zirconium Carbide Coatings
Authors: Wang Yiguang , Liu Qiaomu , Liu Jinling , Zhang Litong , Cheng Laifei
Published: April 2008

Zirconium carbide (ZrC) coatings were fabricated by chemical vapor deposition (CVD) using ZrCl4, CH4/C3H6, and H2 as precursors. Both thermodynamic calculation results and the film compositions at different temperatures indicated that zirconium and carbon deposited separately during the CVD process. The ZrC deposition rates were measured for CH4 or C3H6 as carbon sources at different temperatures based on coating thickness. The activation energies for ZrC deposition demonstrated that the CVD ZrC process is controlled by the carbon deposition. This is also proven by the morphologies of ZrC coatings.
Space Charge‐Mediated Ionic Transport in Yttria‐Stabilized Zirconia–Alumina Composite Membranes
Authors: Kumar Binod , Thokchom Joykumar S.
Published: April 2008

This paper reports ionic conductivity of yttria‐stabilized zirconia (YSZ)–Al2O3 composite membranes. The tape cast specimens were subjected to binder burnout (500°C) and sintering (1550°C) processes to obtain 200–300 μm thick membranes. The ionic conductivity and microstructure of the membranes were characterized and are discussed in this paper. The ionic conductivity of the composite specimens was enhanced and was correlated with the number of charge carrier and their mobility. The solubility of Al2O3 in YSZ was minimal and nanosize Al2O3 of the batch sintered into microsize and existed as a distinct phase. The scanning electron microscopy micrographs revealed that YSZ and Al2O3 grains were strained.
Electrical Properties of Textured Potassium Strontium Niobate (KSr2Nb5O15) Ceramics Fabricated by Reactive Templated Grain Growth
Authors: Alkoy Sedat , Duran Cihangir , Hall David A.
Published: April 2008

Highly [001] textured KSr2Nb5O15 (KSN) ceramics were fabricated by templated grain growth using acicular KSN template particles (5–15 wt%) and reactive matrix of SrNb2O6 and KNbO3. Excess Nb2O5 (1–1.5 wt%) was added as a liquid former. Increasing sintering temperature and time resulted in increased texture with a maximum texture fraction of 0.98. Dielectric, ferroelectric, and piezoelectric measurements indicate anisotropic properties that are close to single crystal values in the textured ceramics with the highest Pr≈18 μC/cm2, Ps≈25 μC/cm2, and d33=65 pC/N obtained in the c‐axis direction.
Solvothermal Synthesis of Si3N4 Nanomaterials at a Low Temperature
Authors: Guo Chunli , Xing Zheng , Ma Xiaojian , Xu Liqiang , Qian Yitai
Published: April 2008

Silicon nitride nanowires or nanorods have been synthesized from SiCl4, NaN3, and metallic Mg at temperatures ranging from 200° to 300°C. X‐ray powder diffraction patterns indicated that the as‐obtained products were mainly β‐Si3N4. Scanning electron microscope and high‐resolution transmission electronic microscopy showed that the samples mostly consisted of Si3N4 nanowires or nanorods. As metallic iron powder was used, α‐Si3N4 was mainly formed at 250°C.
Determination of Scattering and Absorption Coefficients for Plasma‐Sprayed Yttria‐Stabilized Zirconia Thermal Barrier Coatings
Authors: Eldridge Jeffrey I. , Spuckler Charles M.
Published: April 2008

Prediction of radiative transport through translucent thermal barrier coatings (TBCs) can only be performed if the scattering and absorption coefficients and index of refraction of the TBC are known. To date, very limited information on these coefficients, which depend on both the coating composition and the microstructure, has been available for the very commonly utilized plasma‐sprayed 8 wt% yttria‐stabilized zirconia (8YSZ) TBCs. In this work, the scattering and absorption coefficients of freestanding plasma‐sprayed 8YSZ coatings were determined from room‐temperature normal‐incidence directional‐hemispherical reflectance and transmittance spectra over the wavelength range from 0.8 to 7.5 μm. Spectra were collected over a wide range of coating thickness from 60 to almost 900 μm. From the reflectance and transmittance spectra, the scattering and absorption coefficients as a function of wavelength were obtained by fitting the reflectance and transmittance values predicted by a four flux model to the experimentally measured values at all measured 8YSZ thicknesses. While the combined effects of absorption and scattering were shown in general to exhibit a nonexponential dependence of transmittance on specimen thickness, it was shown that for sufficiently high absorption and optical thickness, an exponential dependence becomes a good approximation. In addition, the implications of the wavelength dependence of the plasma‐sprayed 8YSZ scattering and absorption coefficients on (1) obtaining accurate surface‐temperature pyrometer measurements and on (2) applying mid‐infrared reflectance to monitor TBC delamination are discussed.
Conversion of Tetranary Borate Glasses to Phosphate Compounds in Aqueous Phosphate Solution
Authors: Huang Wenhai , Day Delbert E. , Rahaman Mohamed N.
Published: April 2008

In our earlier work, it was found that particles of a ternary alkali‐borate glass, containing either CaO or BaO, converted completely to a crystalline phosphate of calcium or barium when reacted in an aqueous phosphate solution at 37°C. The present work is an extension of our earlier work to investigate the conversion of tetranary borate glass with the composition 10Li2O·10CaO·10(AeO or T2O3)·60B2O3 (weight percent), where Ae is the alkai‐earth metal Mg or Ba, and T is the transition metal La, Sm, or Dy. In the experiments, particles of each glass (150–300 μm) were reacted in 0.25M K2HPO4 solution with a starting pH of ∼9.0 at 37°C. Weight loss and pH measurements indicated that the reaction was complete after 30–50 h, yielding an amorphous product. X‐ray fluorescence showed that the as‐formed product consisted of a calcium phosphate phase that contained the alkali‐earth metal or transition metal present in the starting glass. Heating the as‐formed material for 8 h at 600°–700°C produced a mixture of two crystalline phosphates: calcium phosphate and an alkali‐earth or transition metal phosphate. The kinetics and mechanism of converting tetranary borate glass to phosphate materials are discussed and compared with data from earlier work for the conversion of ternary borate glass.
Calcium Sulfate Hemihydrate Powders with a Controlled Morphology for Use as Bone Cement
Authors: Wang Peng , Lee Eun‐Jung , Park Chee‐Sung , Yoon Byung‐Ho , Shin Du‐Sik , Kim Hyoun‐Ee , Koh Young‐Hag , Park Soon‐Hyo
Published: April 2008

Calcium sulfate hemihydrate (CSH) powders were synthesized for use as bone cement by heat treating calcium sulfate dihydrate (CSD) powders in boiling CaCl2 solutions with various CaCl2 concentrations, ranging from 23.5 to 35.5 wt%, in order to control their morphology. All of the prepared CSH powders showed X‐ray diffraction peaks corresponding to the CSH structure without any secondary phases, implying complete conversion from the CSD phase to the CSH phase. It was also observed that the concentration of CaCl2 significantly affected the morphology of the CSH powder that was synthesized. In other words, as the CaCl2 concentration was decreased from 35.5 to 23.5 wt%, the morphology notably changed from long‐and‐slim hexagonal rods with an aspect ratio of 5.5 to fat‐and‐short hexagonal columns with an aspect ratio of 1.4. This reduction in the aspect ratio led to a significant improvement in the compressive strength of the CSD cement prepared by mixing the CSH powders with water.
Hydrogen‐Induced Failure in ZnO Multilayer Ceramic Chip Varistors with a Zinc Phosphate Passivation Layer
Authors: Chen Wan Ping , Zhu Kan , Wang Yu , Chan Helen L. W. , Wu Jun , Ye Chang He
Published: April 2008

Zinc oxide multilayer ceramic chip varistors (MLVs) with a zinc phosphate passivation layer were studied using electrochemical hydrogen charging, in which hydrogen was deposited on the termination electrodes of MLVs through the electrolysis of water in 0.01m NaOH solution. The properties of the MLVs remained stable during the first stage of electrochemical hydrogen charging, except that the capacitance was increased slightly. Then a second stage appeared in which the properties of the MLVs were quickly and greatly degraded. The zinc phosphate passivation layer was found to be responsible for producing the first stable stage of electrochemical hydrogen charging. A passivation layer is of great importance to prevent hydrogen‐induced failure for MLVs in service.
Effect of Concentration of Ammonium Poly(acrylate) Dispersant and MgO on Coagulation Characteristics of Aqueous Alumina Direct Coagulation Casting Slurries
Authors: Prabhakaran Kuttan , Kumbhar Chandrashekhar S. , Raghunath Sooraj , Gokhale Nitin Madusudhan , Sharma Suresh Chandra
Published: April 2008

Coagulation of aqueous alumina slurries prepared using various concentrations (0.43–1.04 wt% based on alumina) of ammonium poly(acrylate) dispersant by MgO has been studied for direct coagulation casting (DCC) of alumina. The slurries prepared at dispersant concentration below 0.84 wt% are not suitable for DCC at room temperature (∼30°C) as they undergo premature coagulation. Mixing the slurry with MgO at a low temperature of nearly 5°C slows down the reactions leading to coagulation and keeps the slurry viscosity low for a sufficient period of time. Coagulation of slurries prepared at a dispersant concentration of 0.92 wt% and above at room temperature requires MgO concentrations much higher than the equivalent amount required for reaction with the dispersant. This anomalous behavior at higher dispersant concentration is explained such that the Mg‐poly(acrylate) formed by the reaction between ammonium poly(acrylate) and MgO formed a sheath over the remaining MgO particles and prevented them from further dissolution at room temperature. Faster coagulation could be achieved by heating the slurries after casting in closed molds. The Mg‐poly(acrylate) acts as a binder and stabilizes the coagulated bodies as their strength and stability against oscillatory stresses increase with an increase in dispersant concentration.
Report from the Field: Skin‐in‐Solutions: Militarizing Medicine and Militarizing Culture in the United States Military
Authors: Bickford Andrew
Published: April 2008

The US military's creation and deployment of “Human Terrain Teams” and the use of anthropology as a weapon in counterinsurgency operations bears a disturbing similarity to militarized forms of medicine and biotechnology currently in development for US military personnel. Through the mobilization and instrumentalization of health, the US military intends to manipulate the bodies of soldiers while claiming that this manipulation is to protect the well‐being of the soldier. This sort of deployment of health has little to do with the health of the individual, and is directly linked to “improving” the combat abilities of the individual, and of creating better and more encompassing means of control of the individual. As I see it, the Human Terrain System, and attempts to deploy a militarized anthropology to aid in counterinsurgency operations utilize a similar rationale, a rationale directly at odds with the AAA code of ethics and what I think it means to be an anthropologist.
TNF‐α TGF‐β2 and IL‐1β levels in gingival and peri‐implant crevicular fluid before and after de novo plaque accumulation
Authors: Schierano Gianmario , Pejrone Giovanni , Brusco Paola , Trombetta Antonella , Martinasso Germana , Preti Giulio , Canuto Rosa Angela
Published: April 2008

Aims: The aim of this split‐mouth study was to investigate levels of tumour necrosis factor alpha (TNF‐α), transforming growth factor beta (TGF‐β2) and interleukin‐1 beta (IL‐1β) in gingival crevicular fluid (GCF) and peri‐implant crevicular fluid (PICF) after a 21‐day‐period of de novo plaque accumulation in the same patient.

Material and Methods: In 25 patients, samples of GCF and PICF were collected in the sulcus of the tooth and of the implant after professional hygiene. After the no‐hygiene phase (21 days), second samples of GCF and PICF were taken. Third samples were collected after 69 days of re‐establishment oral hygiene techniques. The crevicular fluids were used to determine the volume and the levels of TNF‐α, TGF‐β2 and IL‐1β.

Results: The volume of the crevicular fluids increased significantly after 21 days of plaque accumulation around teeth and implants and decreased significantly by 69 days. TNF‐α and TGF‐β2 did not change significantly among the three different samples. A significant increase of IL‐1β was observed after plaque accumulation around the teeth GCF, whereas in the PICF the increase was not statistically significant.

Conclusions: These data suggest that increased volumes of GCF and PICF could be useful markers of early inflammation in gingival and peri‐implant tissues. In the presence of de novo plaque, implants showed lower, and nearly significant, levels of IL‐1β compared with teeth.
Critical role of glutathione in melatonin enhancement of tumor necrosis factor and ionizing radiation‐induced apoptosis in prostate cancer cells in vitro
Authors: Sainz Rosa M , Reiter Russel J. , Tan Dun‐Xian , Roldan Francis , Natarajan Mohan , Quiros Isabel , Hevia David , Rodriguez Carmen , Mayo Juan C
Published: April 2008

Abstract:  The role of antioxidants in reducing cancer initiation and progression has been highlighted in recent years. Not only antioxidants limit cancer cell growth but also, in some situations, they promote the effectiveness of conventional treatments. Melatonin, an endogenously synthesized antioxidant, reduces cell growth of several tumor types both in vivo and in vitro. Additionally, the indole limits the collateral damage induced by many chemotherapeutic agents. By using a cellular model of human prostate cancer, we studied the ability of melatonin to enhance apoptosis induced by tumor necrosis factor or gamma radiation. It has been reported that melatonin reduces prostate cancer cell growth and, more recently, it promotes cell differentiation. In this work, we also show that melatonin elevates p21 protein levels and increases antioxidant capacity of prostate cancer cells. In addition, melatonin significantly enhances hrTNFα induced cell death by decreasing NFκB activation. Bcl‐2 and survivin down‐regulation appears to be associated to apoptosis stimulation under NFκB inhibition. On the contrary, melatonin does not promote irradiation‐induced cell death due to an increment in intracellular glutathione content. In conclusion, prevention of NFκB activation by melatonin enhances the effectiveness of cytokine treatment in prostate cancer cells but it is not sufficient to enhance cell death triggered by other therapies which generate free radicals. A crucial role of glutathione in survival mechanisms of prostate cancer cells should be carefully considered.
Can disturbances in the atmospheric electric field created by powerline corona ions disrupt melatonin production in the pineal gland?
Authors: Henshaw Denis L. , Ward Jonathan P. , Matthews James C.
Published: April 2008

Abstract:  Recent epidemiological studies have reported an increased risk of leukemia in adults and children near overhead high voltage powerlines at distances beyond the measured range of the direct electric and magnetic fields. Corona ions are emitted by powerlines, forming a plume that is carried away from the line by the wind. The plume generates highly variable disturbances in the atmospheric electric field of tens to a few hundred V/m on time scales from seconds to minutes. Such disturbances can be seen up to several hundred meters from powerlines. It is hypothesized that these random disturbances result in the disruption of nocturnal melatonin synthesis and related circadian rhythms, in turn leading to increased risk of a number of adverse health effects including leukemia. In support of the hypothesis, it is noted that melatonin is highly protective of oxidative damage to the human hemopoietic system. A review of electric field studies provides evidence that (i) diurnal variation in the natural atmospheric electric field may itself act as a weak Zeitgeber; (ii) melatonin disruption by electric fields occurs in rats; (iii) in humans, disturbances in circadian rhythms have been observed with artificial fields as low at 2.5 V/m. Specific suggestions are made to test the aspects of the hypothesis.
Toxicity and Endocytosis of Spinocerebellar Ataxia Type 6 Polyglutamine Domains: Role of Myosin IIB†
Authors: Marquèze‐Pouey Béatrice , Martin‐Moutot Nicole , Sakkou‐Norton Marie , Lévêque Christian , Ji Yong , Cornet Véronique , Hsiao Wendy L. , Seagar Michael
Published: April 2008

Spinocerebellar ataxia type 6 (SCA6) is a dominantly inherited neurodegenerative disease caused by a small expansion of CAG repeats in the sequence coding for the cytoplasmic C‐terminal region of the Cav2.1 subunit of P/Q‐type calcium channels. We have tested the toxicity of mutated Cav2.1 C‐terminal domains expressed in the plasma membrane. In COS‐7 cells, CD4–green fluorescent protein fused to Cav2.1 C‐terminal domains containing expanded 24 polyglutamine (Q) tracts displayed increased toxicity and stronger expression at the cell surface relative to ‘normal’ 12 Q tracts, partially because of reduced endocytosis. Glutathione S‐transferase pull‐down and proteomic analysis indicated that Cav2.1 C‐termini interact with the heavy and light chains of cerebellar myosin IIB, a molecular motor protein. This interaction was confirmed by coimmunoprecipitation from rat cerebellum and COS‐7 cells and shown to be direct by binding of in vitro‐translated 35S‐myosin IIB heavy chain. In COS‐7 cells, incremented polyglutamine tract length increased the interaction with myosin IIB. Furthermore, the myosin II inhibitor blebbistatin reversed the effects of polyglutamine expansion on plasma membrane expression. Our findings suggest a key role of myosin IIB in promoting accumulation of mutant Cav2.1Ct at the plasma membrane and suggest that this gain of function might contribute to the pathogenesis of SCA6.
SURPRISE
Authors: Adler Jonathan E.
Published: April 2008

Abstract Surprise is of great value for learning, especially in cases where deep‐seated preconceptions and assumptions are upset by vivid demonstrations. In this essay, Jonathan Adler explores the ways in which surprise positively affects us and serves as a valuable tool for motivating learning. Adler considers how students’ attention is aroused and focused self‐critically when their subject matter–related expectations are not borne out. These “surprises” point students toward discoveries about gaps or weaknesses or false assumptions within their subject matter understanding; as a result, students become internally motivated to correct their errors and to seek better understanding, rather than merely responding to external mandates imposed by a teacher, institution, or other authority. In this essay Adler argues persuasively that the use of surprise in teaching, both as a pedagogical tool and a topic of study, offers many educational advantages and benefits for learning.
WHAT SHOULD WE TEACH AS CONTROVERSIAL? A DEFENSE OF THE EPISTEMIC CRITERION
Authors: Hand Michael
Published: April 2008

Abstract There is an emerging consensus that to teach something as controversial is to present it as a matter on which different views are or could be held and to expound those different views as impartially as possible. This raises an important normative question that has yet to receive the attention it deserves from educational theorists: how are we to decide which topics to teach in this way? The answer suggested by Robert Dearden is that we should apply the epistemic criterion: a matter should be taught as controversial when contrary views can be held on it without those views being contrary to reason. In this essay, Michael Hand aims to defend that answer. In the first part of the article he revisits Dearden’s rather thin and unsatisfactory justification for the epistemic criterion and attempts to mend its deficiencies. In the second part, Hand examines an alternative to the epistemic criterion in the area of moral education, an alternative he labels the political criterion, and explains why he thinks we should reject it.
Sp1‐like sequences mediate human caspase‐3 promoter activation by p73 and cisplatin
Authors: Sudhakar Cherukuri , Jain Nishant , Swarup Ghanshyam
Published: April 2008

Caspase‐3 is a cysteine protease that plays a central role in the execution of apoptosis induced by a wide variety of stimuli. However, little is known about the mechanisms involved in the regulation of caspase‐3 gene transcription. This study was carried out to characterize the human caspase‐3 promoter and to understand the mechanisms involved in the induction of caspase‐3 gene expression in response to the anticancer drug cisplatin and p73. Caspase‐3 gene expression was induced by treatment of cells with cisplatin, which also induced p73 protein in HeLa and K562 cells. The human caspase‐3 promoter was cloned and characterized. p73β strongly activated the caspase‐3 promoter, whereas p73α showed less activation. Cisplatin treatment increased caspase‐3 promoter activity. Basal and cisplatin‐induced promoter activity was inhibited by the p73 inhibitor p73DD. Deletion analysis defined a minimal promoter of 120 base pairs, which showed good basal and p73β‐induced activity. The examination of the minimal promoter sequence showed several putative Sp1 sites, but no p53/p73 site. The caspase‐3 promoter was activated by Sp1 in Sp1‐deficient Drosophila SL‐2 cells. Sp1‐induced promoter activity was further enhanced by p73β in SL‐2 cells. Mutation of Sp1 sites in the minimal promoter resulted in a loss of basal and p73‐induced promoter activity. These results show that caspase‐3 gene transcription is induced by cisplatin, which is mediated partly by p73. We have identified p73 and Sp1 as activators of the caspase‐3 promoter. Sp1‐like sequences in the minimal promoter not only sustain basal promoter activity, but also mediate p73‐induced activation of the promoter.
Therapeutic Plasma Exchange Combined With Immunomodulating Agents in Secondary Progressive Multiple Sclerosis Patients
Authors: Grapsa Eirini , Triantafyllou Nicolaos , Rombos Antonios , Lagouranis Antonios , Dimopoulos Meletios‐Athanasios
Published: April 2008

Abstract:  Multiple sclerosis (MS) is the most common cause of neurological disability. Therapeutic plasma exchange (TPE) has been used in the management of patients with MS with equivocal efficacy. With this work we would like to present our experience with 10 patients (seven male and three female, mean age 34 years [range 27–53 years]) with secondary progressive MS, who were treated with immunomodulating agents and who also underwent TPE. The patients' expanded disability status scale (EDSS) score of entry to the study varied from 5.0 to 6.5. One year before study entry all patients showed a marked deterioration (12 months before starting TPE they had been rated 4.5–5.5 on the EDSS). TPE was performed three times a week for two weeks and thereafter once a week, or once a month for the stable patients. The machine used was the Cobe Spectra and albumin 5% was the replacement fluid. Peripheral veins were used in nine patients and indwelling vascular access was required in one patient. Eighteen months later, patients stopped taking the immunomodulating agent therapy and continued only with TPE. No side‐effects occurred during the TPE session. After 36 months of TPE therapy, five patients were stabilized in their disability, while two patients showed a minor progression of the disease (an additional 0.5 degree in disability as determined by the EDSS). No relapses occurred during TPE. Three patients stopped the therapy: one patient because of persistent nausea and two patients for reasons unrelated to TPE. Periodic TPE was associated with reduced accumulation of neurological deficits (as documented by EDSS) in patients with secondary progressive MS.
Platelet (Dys)function and Plasma Plasminogen Levels in Hemodialysis Patients
Authors: Salobir Barbara , Sabovic Miso , Zupan Irena Preloznik , Ponikvar Jadranka Buturovic
Published: April 2008

Abstract:  The factors contributing to platelet dysfunction in hemodialysis patients are still not completely known. We explored whether the fibrinolytic system influences platelet function in hemodialysis patients. We measured standard fibrinolytic parameters and markers of fibrinolysis/coagulation activation, and correlated them to platelet aggregation in 15 hemodialysis patients. Fifteen healthy age‐matched volunteers served as controls. Hemodialysis patients had significantly decreased levels of plasminogen (0.76 [0.64–0.86] vs. 0.98 [0.87–1.08] rel, P < 0.001), and increased levels of fibrinogen (4.6 [3.9–5.5] vs. 4.0 [3.4–4.6] g/L, P < 0.05), whereas tissue‐type plasminogen activator antigen and plasminogen activator inhibitor (PAI)‐1 antigen and PAI activity were comparable to controls. Furthermore, elevated levels of markers of fibrinolysis/coagulation were found in hemodialysis patients: d‐dimer (280 [170–460] vs. 135 [120–150] ng/mL, P < 0.01), prothrombin fragments 1 + 2 (1.7 [1.4–1.9] vs. 1.1 [1.0–1.2] nmol/L, P < 0.001), and thrombin–antithrombin complexes (5.2 [4.2–17.7] vs. 0 [0–4.2]μg/L, P < 0.01). The aggregation of platelets (induced by adenosine diphosphate) was slightly impaired in patients compared to controls (72 [43–79] vs. 83 [73–88]%, P = 0.08). Analysis showed that platelet aggregation positively correlated with plasminogen levels (r = 0.48, P < 0.01). No correlation with other fibrinolytic parameters or markers of activation was found. In hemodialysis patients platelet (dys)function appears to be associated with both the fibrinolytic and coagulation systems. We found that platelet aggregation significantly correlates with plasma plasminogen levels. This relation, which has not been hitherto described, seems to be causal and clinically important. Further exploration of this may help us to better understand the mechanisms of platelet dysfunction in hemodialysis patients.
Persistence of Hepatitis B Vaccine Immunity in Hemodialysis Patients
Authors: Ramezani Amitis , Velayati Ali Akbar , Eslamifar Ali , Banifazl Mohammad , Ahmadi Farrokhlagha , Maziar Sima , Razeghi Effat , Kalantar Ebrahim , Amirkhani Aref , Aghakhani Arezoo
Published: April 2008

Abstract:  Although the efficacy of hepatitis B vaccines in patients undergoing chronic hemodialysis (HD) treatment has been documented, the persistence of immunity in this population remains largely unknown. In this study we evaluated the persistence of hepatitis B vaccine immunity in HD patients. We followed 37 hepatitis B vaccinated HD patients (following a four‐dose vaccination schedule of 40 μg injections intramuscularly in the deltoid muscle at 0, 1, 2, and 6 months) for up to one year to evaluate the persistence of immunity (as indicated by serum levels of hepatitis B surface antibody (anti‐HBs) equal to or higher than 10 IU/L). One year after vaccination, 18.9% of patients had lost their anti‐HBs (transient responders), while 81.1% still had detectable antibodies in the serum (persistent responders). From 81.1% of persistent responders 11.5% and 88.5% were weak and high responders, respectively. There was no significant difference between persistent and transient responders regarding age, sex, or nutritional factors. We did not find any factors that related to maintaining protective levels of anti‐HBs in HD patients. It seems that an antibody titer above 100 IU/L following vaccination is necessary in order to maintain that level of antibody one year later.
Assessment of Plasma Antioxidant Status in Hemodialysis Patients
Authors: Kadkhodaee Mehri , Hemmati Mohammad , Zahmatkesh Maryam , Ghaznavi Rana , Mirershadi Fatemeh , Mahdavi‐Mazde Mitra , Seifi Behjat
Published: April 2008

Abstract:  The risk of atherosclerosis and cancer is high in patients on hemodialysis. A breakdown in the natural balance between the activity of the body's antioxidant system and the production of oxidizing agents is suggested to be involved. To investigate the oxidative stress status in Iranian hemodialytic patients, in this study we evaluated plasma vitamin E, malondialdehyde (MDA), reduced glutathione (GSH), and ferric reducing antioxidant power (FRAP) levels in these patients. Twenty‐four hemodialytic patients and 24 control subjects (age and sex matched) were included in this study. Each patient was under dialysis, three times per week, four hours in each session. Before and after dialysis, blood was taken for biochemical measurements as well as oxidative stress tests. There was a significant decrease in FRAP and GSH levels after dialysis comparing to before treatment levels. MDA was increased by dialysis and vitamin E levels were less in dialytic patients, both before and after treatment, compared to controls. This study indicates that there is a significant level of oxidative stress in chronic renal patients and this stress is augmented by dialysis. Antioxidant therapy could be considered in these patients.
Influence of Intravenous Drug Abuse on Native Arteriovenous Fistula Thrombosis in Chronic Hemodialysis Patients
Authors: Chou Che‐Yi , Tseng Yu‐Hsiang , Shih Chuen‐Ming , Huang Chiu‐Ching , Chen Walter , Chang Wu‐Long , Hsu Che‐Wei
Published: April 2008

Abstract:  The influence of intravenous drug abuse (IVDA) on native arteriovenous fistula thrombosis (NAT) in chronic hemodialysis patients is unknown. We conducted a retrospective study of 123 chronic hemodialysis patients incarcerated in a male prison in Mid‐Taiwan. All patients were dialyzed three times per week, 4 h per session. The development of NAT was compared in patients with a history of IVDA (42, 34.1%) and those without (81, 65.9%). A total of 36 patients experienced one or more NAT episodes in 6 years and 29 (80.6%) of them had a history of IVDA. In these 29 patients, 22 (75.9%) relied on repeated thrombectomy or thrombolysis therapy to maintain patent vascular access. In Kaplan–Meier survival analysis, patients with a history of IVDA were prone to develop NAT (log‐rank, P < 0.001). The result of Cox regression suggested that a history of IVDA, independent of diabetes, was associated with the development of NAT. Patients with a history of IVDA, even after IVDA has stopped, were still prone to develop NAT and vascular access infection.