bluuebunny/crossref_metadata_2025 huggingface dataset:
Introduction to computers and their development
Authors: Brown James E.
Published: April 2008

A data processing system can be a calculator, a bookkeeping machine, or a computer. Computers are based upon these five basic elements: a control unit, an arithmetic unit, memory unit, input unit, and output unit. Historically, first generation systems were physically large, able to be programmed only by bit manipulation machine language, very slow, and required extensive air conditioning and atmospheric control. Second generation computers saw the transition from electronic tubes to transistorized circuits speeding up internal processing. High levels compilers and assemblers were introduced, enabling programs to be written on a one‐for‐one assembly language basis, or on a two‐to‐one, three‐to‐one or more basis by using a compiler. Third generation systems saw significant improvements in utilization of microminiaturized circuits and interrupt handling that permitted development of complex operating systems including extensive progress in the area of time sharing and communications uses. Additional computers, first introduced in 1960, are the minicomputers. These minicomputers usually function in a dedicated environment and have many characteristics originally found in the third generation systems as well as many unique qualities of their own. Characteristics that categorize a computer as being a “mini” include purchase price of less than $25,000 at introduction, a memory size of 4000 bytes or more, minimal system configuration, and, usually, outright purchase. Minicomputer manufacturers are finding a large market for their product with dedicated applications and the original equipment manufacturer. The minicomputer may be the basis for still another generation of computers.
Applications of nonlinear programming to detergent formulations
Authors: Steinle Edmund C. , Hendrix Charles D. , Fields Robert R.
Published: April 2008

Designed experiments have been used to secure orthogonal data in a typical light duty liquid detergent system. Regression analyses of the data have provided prediction equations relating composition to performance and physical properties for formulations in this system. The use of these equations in a nonlinear programming computer optimization program is described, illustrated by examples taken from a limited subsystem wherein two of the six components are held constant. Costs, types and uses of such optimization procedures are considered.
A computer approach toward automation of a chemical services laboratory: II. Management information
Authors: Munson A. W. , Schneider E. L.
Published: April 2008

A Real Time Information Management System is described which is based on several interacting data bases. Fifteen dynamic files are accessed by 70 chemists and microbiologists through the use of computer terminals and more than 25 programs. The System provides for real time work scheduling for a chemical laboratory and the generation of all reports. The System also handles accounting, billing, summarization, analysis and distribution of all laboratory functions. The system is open ended, and therefore, expandable. There is no dependency to a particular computer but rather only the need for a computer that can handle terminals and dynamic files.
Postulated scheme forβ crystal structures of mixed palmitic‐stearic triglycerides
Authors: Lutton E. S.
Published: April 2008

A structural scheme is proposed forβ phases of the six palmitic‐stearic triglycerides, based on known configurations of tricaprin and 2‐11‐bromoundecanoyl‐1,1′‐dicaprin. The scheme receives some support from short spacing and binary system data.
Methyl 9(10)‐formylstearate by selective hydroformylation of oleic oils
Authors: Frankel E. N.
Published: April 2008

A highly selective catalyst system has been discovered for the hydroformylation of methyl oleate into methyl 9(10)‐formylstearate in high yields. A rhodium catalyst in the presence of triphenylphosphine is used with oleic esters, acids or triglycerides. Hydroformylation proceeds smoothly at 95‐110C with a 1:1 mixture of H2 and CO at 500 to 2000 psi with or without a solvent, such as toluene. The formylstearate obtained in 90% to 99% conversion from oleate can be either hydrogenated (Raney Ni) or reduced (NaBH4) to hydroxymethylstearate or oxidized (KMnO4) to carboxystearate. According to TLC and mass spectrometry, the methylated carboxystearate consists of about equal proportions of the 9 and 10 isomers. Addition of triphenylphosphine inhibits isomerization of the double bond and leads to the formation of a rhodium carbonyl triphenylphosphine complex, which is apparently the active catalyst. Other known methods for hydroformylation (cobalt carbonyl) and carboxylation (Koch’s method) of oleate give a wide distribution of isomers.
1,3‐Diacyl derivatives of imidazolidine and hexahydropyrimidine: II. Antimycotic activity
Authors: Mod Robert R. , Magne Frank C. , Sumrell Gene , Novak Arthur F. , Solar James M.
Published: April 2008

Series of 1,3‐diacylated derivatives of imidazolidine and hexahydropyrimidine have been screened for antimycotic activity. Optimum activity was found for the 1,3‐dihexanoyl derivatives in the imidazolidine series, with the higher and lower derivatives being much less active. In the hexahydropyrimidine series the 1,3‐dipentanoyl, ‐dihexanoyl,‐diheptanoyl and ‐dioctanoyl derivatives all exhibited a high degree of inhibition against all four of the test organisms. The latter wereTrichophyton rubrum, T violaceum, Microsporum gypseum andAspergillus flavus.
Emulsifier/oil system for reduced calorie cakes
Authors: Rasper V. F. , Kamel B. S.
Published: April 2008

Several emulsifiers were tested for their effects on the functionality of white layer cake batters in which plastic shortening was replaced with vegetable oil. The RV‐1 emulsifier, a water dispersion of a mixture of sodium stearoyl lactylate, sorbitan monostearate and polysorbate 60 gave the best results when used in cake batters having the oil (corn oil or canola oil) content reduced as low as 6 or 3% (on flour basis) and sucrose (30%) replaced with either sorbitol or polydextrose. The cakes were comparable in quality with the plastic shortening control. To achieve this comparable quality, the emulsifier was used at 3% on flour basis and at a higher hydration than that of the control. Somewhat lower, but still acceptable, rating was received by cakes prepared with Atlas A. Propylene glycol mono fatty acid Esters (PGME, Atmul P 44 and RV) were found unsuitable for the tested system under the given conditions of formula and procedure.
Cholesterol oxides in Swedish food and food ingredients: Lard and bacon
Authors: Nourooz‐Zadeh Jaffar , Appelqvist Lars‐Åke
Published: April 2008

Lard samples, manufactured from adipose tissue, were found to contain traces and/or quantifiable concentrations of certain cholesterol oxides, viz., 5α‐, 6α‐epoxycholestanol, 7‐ketocholesterol, 7α‐hydroxycholesterol, 20α‐hydroxycholesterol and 25‐hydroxycholesterol at the detection limit 0.1 ppm. The influence of steam refining and chemical refining on the cholesterol oxide levels in a few of the crude lard samples was investigated. The analyses showed that these processes had no appreciable effect on the concentrations of cholesterol oxides, compared with the controls. Analysis of cold‐stored consumer packages of lard (2‐mo old up to 18‐mo old samples) indicated that there were no differences in the pattern of cholesterol oxides. On the other hand, storage of refined superior and regular grade lard samples at 50°C for up to 18 days caused only a slight increase in the levels of the isomeric 5,6‐epoxycholestanols. Raw bacon, bacon fried at 170°C for 10 and 20 min and bacon dripping were analyzed. The analyses showed that quantifiable levels of 5α‐,6α‐epoxycholestanol, C‐7 oxidation derivatives of cholesterol and 25‐hydroxycholesterol could be detected only in the fried rind. A substantial amount (about 0.5 ppm) of a cholesterol metabolite was detected in the lard samples. Its identification as 7α‐hydroxycholest‐4‐en‐3‐one was based on the comparison of RRT value and mass spectral information, as TMS‐ether, to that of synthetic 7α‐hydroxycholest‐4‐en‐3‐one.
PPARs as therapeutic targets for correction of inborn mitochondrial fatty acid oxidation disorders
Authors: Djouadi F. , Bastin J.
Published: April 2008

Enzyme defects in the mitochondrial fatty acid oxidation (FAO) are a large family of inherited metabolic disease well characterized clinically and genetically, but for which pharmacological strategies remain limited. It is now well established that regulation of genes involved in mitochondrial FAO is under control of the PPAR (peroxisome proliferator activated receptor) signalling pathway, and this led us to test a possible pharmacological correction of FAO disorders by fibrates and other PPAR activators. This review presents the basic data supporting our initial hypothesis, summarizes the results obtained in cells from patients with CPT II (carnitine palmitoyltransferase II) or VLCAD (very long‐chain acyl‐CoA dehydrogenase) deficiency, and discusses the perspectives and limits of this approach for therapy of these disorders.
On the entropy of linear factors
Authors: WEISS BENJAMIN
Published: April 2008

In general, the entropy $h(\mathcal {Y})$ of a stationary process $\mathcal {Y}$, which is a factor of the process $\mathcal {X}$, can take any value in the interval $(0, h( \mathcal {X} ) ]$. For linear factors the situation is completely different. In fact it even matters how the class of linear factors is defined. We will investigate both moving averages of bounded sequences by coefficients in l1 and the natural notion in L2.
Large deviations in non-uniformly hyperbolic dynamical systems
Authors: REY-BELLET LUC , YOUNG LAI-SANG
Published: April 2008

We prove large deviation principles for ergodic averages of dynamical systems admitting Markov tower extensions with exponential return times. Our main technical result from which a number of limit theorems are derived is the analyticity of logarithmic moment generating functions. Among the classes of dynamical systems to which our results apply are piecewise hyperbolic diffeomorphisms, dispersing billiards including Lorentz gases, and strange attractors of rank one including Hénon-type attractors.
Dynamics of two-dimensional Blaschke products
Authors: PUJALS ENRIQUE R. , SHUB MICHAEL
Published: April 2008

In this paper we study the dynamics on $\mathbb {T}^2$ and $\mathbb {C}^2$ of a two-dimensional Blaschke product. We prove that in the case when the Blaschke product is a diffeomorphism of $\mathbb {T}^2$ with all periodic points hyperbolic then the dynamics is hyperbolic. If a two-dimensional Blaschke product diffeomorphism of $\mathbb {T}^2$ is embedded in a two-dimensional family given by composition with translations of $\mathbb {T}^2$, then we show that there is a non-empty open set of parameter values for which the dynamics is Anosov or has an expanding attractor with a unique SRB measure.
Special Issue: Platform product development for mass customization
Authors: HUANG GEORGE , JIAO ROGER , TSENG MITCHELL M.
Published: April 2008

Platform product development is a contemporary approach to agile
product development for mass customization. Distinctive product variants
are derived or customized from a platform that is defined as components
and subsystems commonly shared across a product family. A well-organized platform is essential to connect different parties of an enterprise
including soliciting customer needs through order fulfillment to field
service. Hence, it is also critical to achieve the economy of scale by
identifying repetitive applications of share tooling, knowledge, and
other resources. In this Special Issue, we attempt to cover the different
aspects of platform product development. The topics span a wider range of
artificial intelligence (AI) disciplines, from knowledge representation
to knowledge support systems. It identifies a fertile area not only for
applying AI to contemporary issues of design and manufacturing systems
but also for enriching the methodology for developing AI systems in
manufacturing enterprises. Indeed, we consider that numerous successful
applications in the industrial sectors highlight a future direction for
productive AI applications in industry.
Post-war and Pre-war
Authors: MARKS SALLY
Published: April 2008

In the aftermath of the 11 September 2001 terrorist attack on the United States, a few book editors seeking a silver lining, however slight, suggested that the global shock might generate a revival of international history. As time passed, works gendering (or engendering) the landscape or re-imagining the city remained dominant in the historical profession. Some international historians addressing very recent periods found a bandwagon and focused on cultural diplomacy, which was largely a post-1945 innovation, but the rest of the field continued to languish. Only time will tell if the optimism of the editors was justified, but whether or not ‘9/11’ (as Americans term it) had any causal role, we now have four studies directed to the international history of Europe in the inter-war era.
Drug testing
Authors: Cowan David A.
Published: April 2008

The analysis of sports samples for prohibited substances began in the 1960s and has developed since then using modern technologies close to the latest scientific discoveries. In this chapter the latest techniques and applications are described as well as the role of the World Anti-Doping Agency as the controlling body for the implementation of these tests. For small molecules, apart from the routine use of GC-MS, the newer techniques include the use of isotope ratio MS to detect testosterone and nandrolone administration and LC-MS/MS (liquid chromatography-tandem MS) to detect diuretics. For large molecules, several applications of LC-MS/MS are described as well as immunoprocedures for erythropoietin and human growth hormone. Finally, the latest method to detect homologous blood transfusion is briefly described.
Magnetodielectric anisotropy study of multiferroicity in Y-doped hexagonal HoMnO3
Authors: Vasic R. , Zhou H. D. , Wiebe C. R. , Brooks J. S.
Published: April 2008

Dielectric measurements are used to characterize magnetic phase transitions in the doped ferroelectric oxides Ho1−xYxMnO3 (x=0–0.8). The focus of this study is on the effects of the magnetic field direction and Y doping on the reentrant T-B-θ phase diagrams below the Néel temperature. The response of Ho sublattice to the applied magnetic field plays a major role in all magnetic phase transitions for Y doping (x=0.0–0.8), consistent with previous results (x=0,0.6,0.8). Two successive Mn spin rotations in the ab plane in the antiferromagnetic state are driven by the exchange interaction with the Ho subsystem, through magnetodielectric coupling. Difference in energy between two ground Mn spin states is correlated with magnetic field induced perturbations in Ho lattice. The coupling between Ho and Mn can be explained by simple geometric relations of uniaxial anisotropy between magnetic field direction and c-axis of hexagonal HoMnO3. The magnetic field anisotropy study is an important step toward the understanding of magnetic and electric phase competition in the diluted Ho 4 f hexagonal system by the nonmagnetic ion yttrium (Y).
Intrinsic property measurement of surfactant-templated mesoporous silica films using time-resolved single-molecule imaging
Authors: Kennard Raymond , DeSisto William J. , Giririjan Thanu Praba , Mason Michael D.
Published: April 2008

Mesoporous silica membranes fabricated by the surfactant-templated sol-gel process have received attention because of the potential to prepare membranes with a narrow pore size distribution and ordering of the interconnected pores. Potential applications include ultrafiltration, biological separations and drug delivery, and separators in lithium-ion batteries. Despite advancements in synthesis and characterization of these membranes, a quantitative description of the membrane microstructure remains a challenge. Currently the membrane microstructure is characterized by the combination of results from several techniques, i.e., gas permeance testing, x-ray diffraction scanning electron microscopy, transmission electron microscopy, and permporometry. The results from these ensemble methods are then compiled and the data fitted to a particular flow model. Although these methods are very effective in determining membrane performance, general pore size distribution, and defect concentration, they are unable to monitor molecular paths through the membrane and quantitatively measure molecular interactions between the molecular specie and pore network. Single-molecule imaging techniques enable optical measurements that probe materials on nanometer length scales through observation of individual molecules without the influence of averaging. Using single-molecule imaging spectroscopy, we can quantitatively characterize the interaction between the probe molecule and the interior of the pore within mesoporous silica membranes. This approach is radically different from typical membrane characterization methods in that it has the potential to spatially sample the underlying pore structure distribution, the surface energy, and the transport properties. Our hope is that this new fundamental knowledge can be quantitatively linked to both the preparation and the performance of membranes, leading to the advancement of membrane science and technology. Fluorescent molecules, 1,1-dioctadecyl-3,3,3,3-tetramethylindo-carbocyanine perchlorate, used to interrogate the available free volume in their vicinity, were loaded into the mesoporous silica membranes at subnanomolar concentrations. The mesoporous silica films were prepared using a nonionic ethylene oxide-propylene oxide-ethylene oxide triblock copolymer surfactant, Pluronic P123, on single crystal silicon substrates using dip coating of a silica sol. Membranes were prepared resulting in an average pore diameter of approximately 5nm as measured by helium, nitrogen permeance, and porosimetry. Fluorescent images and time transient experiments were recorded using a custom built single-molecule scanning confocal microscope at differing temperatures (10, 20, 30, 40, and 50°C). Time-dependent polarization anisotropy was used to obtain the enthalpy of adsorption and Henry’s law constant of the probe molecule.
Characterization of mono- and divacancy in fcc and hcp hard-sphere crystals
Authors: Kwak Sang Kyu , Cahyana Yenni , Singh Jayant K.
Published: April 2008

We determine and compare the thermodynamic properties of mono- and divacancies in the face-centered-cubic and hexagonal-close-packed hard-sphere crystals via a modified grand canonical ensemble. Widom-type particle insertion was employed to estimate the free energy of formation of mono- and divacancies, and the results are supported by an alternative approach, which quantifies the entropy gain of the neighbor particles. In hcp crystal, we found a strong anisotropy in the orientational distribution of vacancies and observe an eightfold increase in the number of divacancies in the hexagonal plane compared to the one in the out of plane at highest density of interest. This phenomenon is induced by the different arrangement and behavior of the shared nearest neighbor particles, which are located at the same distance from each vacant site in divacancy. The effect of divacancies on the free energy is to reduce that of the hcp crystal relative to the fcc by around 7×10−6kBT at melting.
Plasma damage mechanisms for low-k porous SiOCH films due to radiation, radicals, and ions in the plasma etching process
Authors: Uchida Saburo , Takashima Seigo , Hori Masaru , Fukasawa Masanaga , Ohshima Keiji , Nagahata Kazunori , Tatsumi Tetsuya
Published: April 2008

Low dielectric constant (low-k) films have been widely used as insulating materials in ultra-large-scale integrated circuits. Low-k films receive heavy damage during the plasma processes of etching or ashing, resulting in an increase in their dielectric constant. In order to realize damage-free plasma processes for low-k films, it is essential to determine the influence of radiation, radicals, and ions emitted in the plasma process on the characteristics of low-k films. We have developed a technique to evaluate the influence of radiation, radicals, ions, and their synergies on films in real plasma processes and have named it pallet for plasma evaluation (PAPE). Using the PAPE, plasma-induced damage on porous SiOCH films were investigated in dual-frequency capacitively coupled H2∕N2 plasmas. The damage was characterized by ellipsometry, Fourier-transform infrared spectroscopy, and thermal desorption spectroscopy. On the basis of the results, the damage mechanisms associated with vacuum ultraviolet (VUV) and UV radiation, radicals, and ions were clarified. The damage was caused not only by ions and radicals but also by VUV and UV radiation emitted by the plasmas. Moreover, it was found that the synergy between the radiation and the radicals enhanced the damage.
Response of an emulsion of leaky dielectric drops immersed in a simple shear flow: Drops less conductive than the suspending fluid
Authors: Fernández Arturo
Published: April 2008

Direct numerical simulations of the effects of an electric field on an emulsion of drops are presented. A simple shear flow configuration is adopted where the electric field is applied perpendicular to the sliding plates. Both the drops and the suspending fluid are assumed to behave as leaky dielectric fluids. Here, drops less conductive than the suspending fluid with an electrical conductivity ratio smaller than the dielectric permittivity ratio are considered. This combination of electrical properties leads to a viscous fluid motion from the poles to the equator. The response of an emulsion is governed by the competition between the electrical forces, the fluid shear, and the capillary forces. The Mason number [Mn=(3λ+2)μγ̇∕6(λ+1)ε0β2E∞2] and the electric capillary number [Ce=ε0β2E∞2a∕γ] are used to describe the response of the systems. As previously observed in experiments at low shear rates, Mn<0.2, the drops aggregate in chains that tilt under a shear. The competition between the electrical forces and the fluid shear results in shorter chains at intermediate shear rates, 0.2<Mn<2.0. As the fluid shear becomes stronger than the electrical attraction, Mn>2.0, the chains of drops break up. The rheological properties mainly depend on the emulsion microstructure. The effective viscosity exhibits a strong shear-thinning response because the chains of drops, which appear at low shear rates, increase the resistance of the system to shear. As the chains shorten and break up, the effective viscosity decreases. The elastic properties of the emulsion are also affected by the presence of the electric field. Normal stress differences arise as a consequence of the deformation of the drops and the surface tension acting on the interface between the fluids. The shape of the drops is determined by the deformation caused by the viscous forces and the deformation due to the electric stresses. At low shear rates, the electric effects are predominant and the application of an electric field leads the drops to deform into oblate shapes. The oblate deformation results in higher stresses in the direction parallel to the shearing motion than perpendicular to it, which results in a significant increase in the first normal stress difference. As the shear rate is increased, the oblate deformation is supplemented by the deformation due to the fluid shear. The deformation caused by the electric field is also responsible for the negative magnitude of the second normal stress difference in three-dimensional emulsions.
Comprehensive investigation of structural, electrical, and optical properties for ZnO:Al films deposited at different substrate temperature and oxygen ambient
Authors: Dong Bin-Zhong , Hu Hao , Fang Guo-Jia , Zhao Xing-Zhong , Zheng Da-Yu , Sun Yuan-Ping
Published: April 2008

c -axis oriented polycrystalline ZnO:Al (AZO) films were deposited at different substrate temperature (Ts) and oxygen ambient (PO2) by pulsed laser deposition. It is found that with the increase in Ts and PO2, the 2θ position of AZO (0002) shifts to higher angle, which can be attributed to the different amounts and species of defects in AZO films. Furthermore, the full width at half maximum of 2θ and (0002) rocking curve indicate the different crystalline qualities for AZO films grown at different conditions. At the same time, the carrier concentration decreases with the increase in Ts and PO2 for most of the samples; however, the Hall mobility usually attains its maximum at proper Ts and PO2. Moreover the transport of electrons may be governed by different mechanisms for AZO films grown at different conditions. The AZO transmission spectra show that the ultraviolet absorption edge and infrared transparency limit shift toward longer wavelength with the increase in Ts and PO2, which are due to the changes of optical band gap (Eg) and plasma frequency (ωp), respectively. Furthermore the evolutions of Eg and ωp with Ts and PO2 are consistent with that of electrical properties. The intensity of photoluminescence is found to correlate with the carrier concentration which indicates that the transition of electrons between conduction and valence bands dominates the room temperature emission of AZO films.
Reversible radial deformation up to the complete flattening of carbon nanotubes in nanoindentation
Authors: Minary-Jolandan Majid , Yu Min-Feng
Published: April 2008

The reversible flattening up to 60% deformation of individual multiwalled carbon nanotubes (MWCNTs) was revealed with nanoindentation. The nanoindentation induced, in terms of indentation force versus indentation depth, two linear deformation responses and a nonlinear one in between in the measurement of an ∼9nm diameter MWCNT having six walls. A continuum shell model was applied and found to be fully capable of describing the observed behavior and extracting accurate mechanical properties of the MWCNT. The measured linear deformation persisted up to an indentation depth twice the shell thickness of the MWCNT, a behavior much like a macroscopic thin shell in classical shell theory. Nonlinear deformation was subsequently introduced due to the extended flattening of the MWCNT in the axial direction and the formation of high curvature “bulbs” along the edges of a squashed MWCNT. Finally, the elastic deformation of such bulbs initiated the second linear deformation response. The deformation behavior was found to be fully reversible, manifesting the remarkable mechanical performance of CNT as a nanoscale elastic shell in sustaining severe mechanical deformation.
Dielectric and ac conductivity studies on undoped and MgO-doped near-stoichiometric lithium tantalate crystals
Authors: Bhaumik Indranil , Ganesamoorthy S. , Bhatt R. , Karnal A. K. , Wadhawan V. K. , Gupta P. K. , Kumaragurubaran S. , Kitamura K. , Takekawa S. , Nakamura M.
Published: April 2008

Dielectric and ac impedance studies have been carried out on undoped and Mg (0.5 and 1mol%) doped near-stoichiometric lithium tantalate (SLT) single crystals. No particularly significant qualitative change is observed in the nature of the ferroelectric phase transition on doping by Mg. However, an anomaly is observed in the ac impedance data: the ac conductivity is found to be low for 0.5mol% doping of Mg, compared to 1.0mol% doping. Also, the activation energy, calculated from the Arrehenius equation, is highest for 0.5mol% doping, which suggests that hopping of Li+ ions becomes more hindered in 0.5 Mg SLT. The Nyquist plot shows a single semicircle above 100Hz. The electrical behavior of lithium tantalate can be modeled as a resistance parallel to a constant-phase element. The calculated impedance from this equivalent circuit is also found to be high for the 0.5mol% doping. This feature is explained in terms of a Li-vacancy model.
Enhanced ultraviolet emission from ZnO nanocrystals embedded in a hybrid polymer composite layer
Authors: Li Fushan , Son Dong-Ick , Leem Jae-Hyeon , Kim Tae Whan , Dong Wenguo , Kim Young-Ho
Published: April 2008

Self-assembled ZnO nanocrystals embedded in a p-phenylene-biphenyltetracarboximide (BPDA-PDA)-type polyimide (PI) layer or in a hybrid (BPDA-PDA) PI and poly-N-vinylcarbazole (PVK) matrix were formed by curing Zn thin films in a nitrogen atmosphere. Transmission electron microscopy images showed that ZnO nanocrystals were formed inside in the hybrid BPDA-PDA PI and PVK matrix. Photoluminescence (PL) spectra for the ZnO nanocrystals embedded in the BPDA-PDA PI layer and for the ZnO nanocrystals embedded in the hybrid polymer layer showed that addition of PVK significantly increased the luminescence intensity corresponding to the ultraviolet (UV) emission from the ZnO nanocrystals. The luminescence mechanisms related to the green and the UV bands for the ZnO nanocrystals embedded in the BPDA-PDA PI and PVK hybrid layer are described on the basis of the PL results.
Whole-body protein metabolism and energy expenditure in sheep selected for divergent wool production when fed above or below maintenance
Authors: Li L. , Oddy V. H. , Nolan J. V.
Published: April 2008

Rates of whole-body protein turnover and energy expenditure were measured in two groups of wethers differing in estimated breeding values (EBVs) for wool growth, but with similar EBVs for fibre diameter and liveweight (LW). The sheep were offered a pelleted diet at 1.2 times their metabolisable energy (ME) requirement for maintenance (1.2 M) followed by either 0.8 M or 1.8 M for 5 weeks. In the 5th week, whole-body protein metabolism was estimated by using intravenous injection of 15N-glycine (g N/day) and whole-body energy expenditure rate (EE) was predicted by the CO2 entry rate technique using intravenous injection of NaH13CO3. The higher N intake (8.7 v. 20.4 g N/day, P < 0.001) was associated with a higher whole-body protein flux (22.1 v. 34.2 g N/day, P < 0.001), and a higher whole-body protein synthesis rate (17.0 v. 25.5 g N/day, P < 0.001) and protein degradation rate (15.9 v. 20.7 g N/day, P < 0.001). Irrespective of feeding levels, sheep with high-fleece EBVs (F+) synthesised and degraded more body protein N (g N/day) than sheep with low-fleece EBVs (F–), and F+ sheep also retained more ingested protein N (P < 0.05) in wool and body tissue than F– sheep, but the significant differences due to genotypes disappeared when whole-body protein flux, synthesis and degradation were expressed as g N/kg LW0.75.day (metabolic weight). Estimates of EE were lower when the sheep were offered 0.8 M than when offered 1.8 M (5.85 v. 7.68 MJ/day, P < 0.001) and were higher in F+ than in F– sheep (6.95 v. 6.58 MJ/day; P < 0.05), but F+ sheep had a significantly lower (P < 0.05) EE (MJ/kg LW0.75.day) than F– sheep. F+ animals also retained more energy in wool and wool-free body tissue than F– animals (P < 0.05). The present study indicates that genetic selection for wool growth has resulted in increased efficiency of dietary protein and energy use for wool production and body-tissue growth in these sheep. Furthermore, there is no ‘trade off’ between deposition of nutrients in the body and wool in sheep with high EBVs for wool growth.
Ras signaling directs endothelial specification of VEGFR2+ vascular progenitor cells
Authors: Kawasaki Kyoko , Watabe Tetsuro , Sase Hitoshi , Hirashima Masanori , Koide Hiroshi , Morishita Yasuyuki , Yuki Keiko , Sasaoka Toshikuni , Suda Toshio , Katsuki Motoya , Miyazono Kohei , Miyazawa Keiji
Published: April 2008

Vascular endothelial growth factor receptor 2 (VEGFR2) transmits signals of crucial importance to vasculogenesis, including proliferation, migration, and differentiation of vascular progenitor cells. Embryonic stem cell–derived VEGFR2+ mesodermal cells differentiate into mural lineage in the presence of platelet derived growth factor (PDGF)–BB or serum but into endothelial lineage in response to VEGF-A. We found that inhibition of H-Ras function by a farnesyltransferase inhibitor or a knockdown technique results in selective suppression of VEGF-A–induced endothelial specification. Experiments with ex vivo whole-embryo culture as well as analysis of H-ras−/− mice also supported this conclusion. Furthermore, expression of a constitutively active H-Ras[G12V] in VEGFR2+ progenitor cells resulted in endothelial differentiation through the extracellular signal-related kinase (Erk) pathway. Both VEGF-A and PDGF-BB activated Ras in VEGFR2+ progenitor cells 5 min after treatment. However, VEGF-A, but not PDGF-BB, activated Ras 6–9 h after treatment, preceding the induction of endothelial markers. VEGF-A thus activates temporally distinct Ras–Erk signaling to direct endothelial specification of VEGFR2+ vascular progenitor cells.
Sleep directly following learning benefits consolidation of spatial associative memory
Authors: Talamini Lucia M. , Nieuwenhuis Ingrid L.C. , Takashima Atsuko , Jensen Ole
Published: April 2008

The last decade has brought forth convincing evidence for a role of sleep in non-declarative memory. A similar function of sleep in episodic memory is supported by various correlational studies, but direct evidence is limited. Here we show that cued recall of face–location associations is significantly higher following a 12-h retention interval containing sleep than following an equally long period of waking. Furthermore, retention is significantly higher over a 24-h sleep–wake interval than over an equally long wake–sleep interval. This difference occurs because retention during sleep was significantly better when sleep followed learning directly, rather than after a day of waking. These data demonstrate a beneficial effect of sleep on memory that cannot be explained solely as a consequence of reduced interference. Rather, our findings suggest a competitive consolidation process, in which the fate of a memory depends, at least in part, on its relative stability at sleep onset: Strong memories tend to be preserved, while weaker memories erode still further. An important aspect of memory consolidation may thus result from the removal of irrelevant memory “debris.”
Modern‐Day Child Slavery1
Authors: Van De Glind Hans , Kooijmans Joost
Published: April 2008

Child slavery is a contemporary global problem existing since ancient times. The concept of slavery and practices similar to it are defined in a range of international instruments. Children are particularly vulnerable to slavery‐like practices, and their special plight is addressed by the UN Convention on the Rights of the Child (CRC–in particular Art 32 on the right to be protected from economic exploitation) and the ILO Worst Forms of Child Labour Convention, 1999 (No. 182). Furthermore, the Palermo Protocol on human trafficking (of 2000) provides important tools to help shape legislative policy against another form of slavery, namely the trafficking of adults and children.
Preference‐weighted health‐related quality of life measures and substance use disorder severity
Authors: Pyne Jeffrey M. , French Michael , McCollister Kathryn , Tripathi Shanti , Rapp Richard , Booth Brenda
Published: April 2008

Aims  Examine the validity of preference‐weighted health‐related quality of life measures in a sample of substance use disorder (SUD) patients. The implications of cost–utility analyses (CUAs) of SUD interventions are discussed.

Design  Cross‐sectional analysis of subjects seeking SUD treatment.

Setting  Seven SUD treatment centers in a medium‐sized Midwestern metropolitan area in the United States.

Participants  Data from 574 SUD subjects were analyzed from a study to test interventions to improve linkage and engagement with substance abuse treatment.

Measurements  Subjects completed the following preference‐weighted measures: self‐administered Quality of Well‐Being scale (QWB‐SA) and Medical Outcomes Study SF‐12 (standard gamble weighted or SF‐12 SG); and clinical measures: Addiction Severity Index (ASI) and a symptom checklist based on the DSM‐IV.

Findings  In unadjusted analyses, the QWB‐SA was correlated significantly with six of seven ASI subscales and the SF‐12 SG was correlated with four of seven. In adjusted analyses, both preference‐weighted measures were significantly correlated with diagnostic, physical health, mental health and drug use measures, but not with legal or alcohol use measures. The QWB‐SA was also correlated with employment problems and the SF‐12 SG was correlated with family/social problems.

Conclusions  This study generally supports the construct validity of preference‐weighted health‐related quality of life measures in SUD patients. However, the QWB‐SA and SF‐12 SG did not correlate with all ASI scales. Cost–benefit analysis may be preferable when policy‐makers are interested in evaluating the full range of SUD intervention outcomes.
Relationship between ADAMTS13 activity in clinical remission and the risk of TTP relapse
Authors: Jin Ming , Casper T. Charles , Cataland Spero R. , Kennedy Melanie S. , Lin Shili , Li Yu J. , Wu Haifeng M.
Published: April 2008

Idiopathic thrombotic thrombocytopenic purpura (TTP) is characterized by frequent recurrences. Effective screening for relapses will enable intervention prior to overt episodes of TTP. The present study used a modified assay to detect ADAMTS13 (a disintegrin and metalloprotease with thrombospondin type 1 motif, 13) activity as low as 0·5%. This analytical improvement permits adequate measurement of ADAMTS13 activity levels in 97% of remission samples used for statistical modelling. ADAMTS13 activity and ADAMTS13 antibody (IgG) were measured in 157 serial samples prospectively collected from 24 TTP patients during periods of clinical remission. These patients were followed‐up quarterly for an average of 23 months, during which time nine episodes of TTP relapse occurred among six patients. Finally, logistic regression modelling was used to define the relationship between ADAMTS13 activity levels (0·5–100%) and the probability of TTP relapses. Our data demonstrated that lower ADAMTS13 activity and younger age were significantly associated with higher risk of relapse in the 3 months after specimens were taken. In contrast, ADAMTS13 antibody IgG levels were not predictive of TTP relapses. Identification of low ADAMTS13 activity during clinical remission as a key risk factor for TTP relapses provides a new screening strategy to identify patients who may benefit from prophylactic therapy prior to disease relapses.
Impact of immunohistochemical markers, CK5/6 and E‐cadherin on diagnostic agreement in non‐invasive proliferative breast lesions
Authors: MacGrogan G , Arnould L , De Mascarel I , Vincent‐Salomon A , Penault‐Llorca F , Lacroix‐Triki M , Bibeau F , Baranzelli M C , Fridman V , Antoine M , Bécette V , Brouste V , Jacquemier J , Mathoulin‐Pélissier S ,   the GEFPICS group
Published: April 2008

Aims:  To assess the impact of cytokeratin (CK) 5/6 and E‐cadherin immunohistochemistry on diagnostic agreement of non‐invasive proliferative breast lesions.

Methods and results:  Twenty pathologists classified 105 cases of non‐invasive proliferative breast lesions into 10 diagnostic categories. One haematoxylin and eosin (H&E) slide of each case was analysed on a first round and one H&E slide with corresponding CK5/6 and E‐cadherin immunohistochemistry was analysed on a second round. Interobserver reproducibility for category‐specific and management‐specific lesions was measured on each round. CK5/6 and E‐cadherin had little impact on diagnostic agreement, which remained moderate between the first and second rounds (overall κ coefficients of 0.47 and 0.53, respectively, P = NS). Levels of agreement slightly improved for lesions with specific CK5/6 and E‐cadherin immunoprofiles (usual ductal hyperplasia, atypical ductal hyperplasia, atypical lobular hyperplasia, lobular carcinoma in situ, non‐high‐grade ductal carcinoma in situ), but the differences observed were not statistically significant. However, diagnostic agreement improved when lesions were grouped according to their management category (overall κ coefficients of 0.58 and 0.66 in the first and second rounds, respectively).

Conclusions:  CK5/6 and E‐cadherin immunohistochemistry has little impact on interobserver reproducibility for non‐invasive breast lesions. Diagnostic agreement can, however, be improved by grouping lesions in management categories.
How do children do mathematics with LOGO?
Authors: NOSS R.
Published: April 2008

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.
Problems of educational innovation: the primary teacher's response to using the microcomputer
Authors: Heywood G. , Norman P.
Published: April 2008

Abstract An important source of data in ascertaining why teachers avoid using the computer are teachers themselves. Attribution Theory encourages the rationalization of individual actions which may then form a cumulative pattern across and within pre‐specified groups (in this case, primary schools). Such attributions may be used in the design of in‐service education about educational computing.
Teacher education for using microcomputers in the classroom: generic skills to think about
Authors: Dubuc L.
Published: April 2008

Abstract  My purpose is to talk about the generic skills a teacher should master to take best advantage and get the most fruitful pedagogical results from the use of microcomputers in the classroom. Yet, the organization of teacher training differs from country to country so that it is difficult to imagine a single way to prepare a teacher for these skills. So, I intend to address my topic in terms of what I think should be known by a teacher instead of in terms of what should be taught through a specific curriculum.

There is another reason for me to avoid talking formally about pre‐service and in‐service education. Four years ago, Quebec's Ministry of Education launched a plan of action for the pedagogical use of the computer in the classroom and we have gone through quite an evolution in our vision of how teacher training should be organized. We are still wondering whether what we do in that respect is a final picture of what ought to be done. I shall then speak more from the empirical evidence of our action plan than from established scientific proofs.
Children and databases: an analysis of data entry and query formulation
Authors: Spavold J.
Published: April 2008

Abstract This study was undertaken, in part, to analyse the means by which primary children familiarized themselves with a large database. Their approaches to the problems of coding data for entry were studied and the types of error and frequency of occurrence were recorded. Query formulation was studied in parallel with data entry, particularly the difficulties presented by the correct expression of queries, choice of tests and use of coded fields. Attention was paid to the age and sex of the children for both aspects of the study.
Tools for exploratory learning: A research programme*
Authors: Bliss J. , Ogborn J.
Published: April 2008

Abstract The programme will examine the role of tools in exploratory learning through a series of extended‐time studies with children between the ages of 10 and 16. To do this it will modify and/or extend existing software tools and develop new tools where necessary. Exploratory tools allow learners to investigate models of a given domain which are different from theirs and so examine consequences and conflicts. Expressive tools give children the opportunity to express their own models about reality and so learn through representing, exploring and reflecting on the consequences of these. These are different and complementary modes of learning. Further distinctions are made between quantitative, qualitative and semi‐quantitative tools for both exploratory and expressive tools. Two main curriculum areas are selected: Technology and the Humanities.
Collaborating with computers
Authors: McMahon H.
Published: April 2008

Abstract  The main body of the article explores three questions concerning the collaborative use of computers in classrooms. The first looks at the opinions of the powerful as evidenced by the recent spate of publications concerning the National Curriculum; the second explores the extent to which there exists research evidence to support the position the curriculum makers have taken up; the third reviews the literature for indications as to how teachers are likely to react to their proposals. A fourth question niggles: how does the ‘subjective’ computer fit into the classroom? The article ends in speculationperhaps we need to take a fresh look as to why exactly many teachers remain uneasy in the presence of computers?
Student perceptions of aspects of algebraic function using multiple representation software
Authors: Yerushalmy M.
Published: April 2008

Abstract Multiple representation software was used here as the core of the algebra curriculum of eighth graders (age 14 years) learning algebraic functions and graphs. The connection between the symbolic representation of functions and their graphs received special emphasis. Thirty‐five students met 20 times over a 3‐month period in computer‐facilitated lessons. Data was gathered through observations of class work and the results of five paper‐and‐pencil tasks. Three aspects of student perceptions of the concept of function were examined: identification and classification of families of functions, identification of the connections between inclination and slope of graphs, and the distinction between the properties of a function and its picture. Results of student performance on the tasks were analyzed primarily in terms of the type of arguments they used—either standard algebraic computation techniques, visual considerations, or a combination of both. Findings indicated that although the software and the method of teaching both promoted student inventiveness—i.e. original and unexpected conjectures—and enhanced their understanding of the three aspects of function examined, connection between the algebraic manipulations and visual representation did not occur spontaneously.
Misconceptions concerning rotation and angie in LOGO
Authors: Cope P. , Smith H. , Simmons M.
Published: April 2008

Abstract  Twelve children, aged between 10 and 11 years old were given a 12‐hour course in LOGO. The course was taught by a teacher whose knowledge of LOGO was extensive. The emphasis was on the relationship between the turtle rotation and the internal angle in plane figures. The children were tested for their knowledge of angle at the start of the course and when it was finished. In spite of the teacher's attempts to make the children aware that it was the external angles of geometric figures through which the turtle turned, almost all the children focused on the internal angles in the final test. The results suggest using LOGO to draw closed figures may lead to a confusion about angle which is not amenable to conventional teacher intervention in a short course of this nature.
Computing and teaching: a socially‐critical review
Authors: Preston N.
Published: April 2008

Abstract  This paper is based on a study into the social and ethical implications of computer education in Secondary Schools in Queensland (Australia). The author was part of a team which conducted this study. The paper reports on theoretical and social ethical considerations arising from the study and their pedagogical implications. After briefly reviewing the relationship of computer technology and philosophy, the paper outlines three orientations to curriculum‐vocational, liberal and socially‐critical. An argument is presented in favour of a socially‐critical orientation for computer education. The nature of that perspective's critique of technocratic culture is delineated and, finally, the paper discusses what a socially‐critical perspective would mean for computer education in the classroom.