bluuebunny/crossref_metadata_2025_split huggingface dataset:
Seal bond characterization of laminated plastic food cups by scanning electron and optic microscopes
Authors: Ayhan Zehra 
Published: August 2004

AbstractHeat seals of laminated semi‐rigid food cups were evaluated to characterize the seal bond. Laminated lidding material was sealed at temperatures of 160–180°C to thermoformed cups. Various seal regions of the cups with different ultrasonic signal strengths (%) were sectioned at the rim and examined using optical and scanning electron microscopes (SEM). Ultrasonic signals were able to pinpoint seal defects; however, the magnitude of the signals did not relate to the actual seal condition or seal quality affected by the sealing process. This was attributed to the very short seal width and non‐parallel surface of the heat seal, which possibly resulted in signal loss by reflection and scattering from the seal surface. C‐scan of ultrasound, SEM and optical microscopic images provided the information that the heat‐sealing process was unstable, due to insufficient and non‐uniform heat‐seal temperature or pressure, misalignment of the sealing jaws or non‐parallel sealing or cutting unit configuration. Copyright © 2004 John Wiley & Sons, Ltd.
Suitability of alternative fatty food simulants to study the effect of thermal and microwave heating on overall migration of plastic packaging
Authors: Galotto M. J. , Guarda A. 
Published: August 2004

AbstractThe suitability of alternative fatty food simulants on overall migration determination under thermal treatment and microwave heating were analysed for different plastic materials commonly used for packs subjected to thermal treatment or microwave heating. Elevated temperature and microwave heating increased overall migration. The results demonstrated that polymer–simulant affinity plays a large role in determining the suitability of the alternative simulant. For PA/PE, ethanol 95% represented the best alternative fatty food simulant to reproduce overall migration with olive oil. PVC presented a high overall migration. Microwave heating increased migration up to 45 mg/dm2. For PVC, isopropanol was able to reproduce olive oil even after microwave heating. For PP, none of the alternative fatty food simulants were able to reproduce overall migration with olive oil. PP presented high inert behaviour. Microwave heating did not produce a significant increase in overall migration; meanwhile, the time of exposure produced a more significant migration. Copyright © 2004 John Wiley & Sons, Ltd.
Time‐dependent non‐wavepacket theory of electron scattering
Authors: Ritchie Burke , Weatherford Charles A. 
Published: August 2004

AbstractA technique is given for solving the time‐dependent Schrödinger equation for electron+potential scattering at low energies (k2 ≤ 1.0 a.u.). This is accomplished by avoiding wavepackets, with the inevitable wavepacket spreading, and solving a time‐integral form of the Schrödinger equation directly. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Ab initio studies of stepped {100} surfaces of KDP crystals
Authors: Salter E. A. , Wierzbicki A. , Land T. 
Published: August 2004

AbstractPotassium dihydrogen phosphate (KH2PO4, KDP) crystals have important uses in laser components and are grown in large scale for that purpose. The need for habit control has led to interest in the step‐pinning mechanisms that cause growth inhibition of the {100} face. Model systems representing five stepped KDP {100} surfaces are prepared and studied using ab initio quantum methods. Results of Hartree–Fock and density functional theory plane‐wave calculations are presented, including estimated energies of ion and column removal for the steps. Steps terminated by phosphate ions are found to be less energetically favorable than their potassium‐terminated counterparts. In addition, surface layer removal energies for the {100} face and the potassium‐bounded and phosphate‐bounded {101} faces are reported. The potassium‐bounded {101} face is found to have a greater surface removal energy than the unexpressed phosphate‐bounded {101} face. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Capillary electrophoretic separation and theoretical study of inclusion complexes of sulfobutyl ether β‐cyclodextrin with estrogens
Authors: Deng Yuanjian , Huang Ming‐Ju 
Published: August 2004

AbstractFive estrogens (2‐hydroxyestrone, 2‐methoxyestradiol, estrone, estriol, and 17α‐estradiol) and two stereoisomers (17α‐ and 17β‐estradiol) have been successfully separated using capillary electrophoresis with anionic sulfobutyl ether β‐cyclodextrin (SBE‐β‐CD). The SBE‐β‐CD used in the separation was a mixture of positional and regional isomers containing from 1 to 10 sulfobutyl ether groups with an average degree of substitution of four per cyclodextrin; thus, a tetra‐SBE substituted CD, SBE[4]‐β‐CD, has been chosen as the model host molecule in the present study. Relative to the position of the cavity, three initial arrangements of the 4 SBE groups, 0‐, 2‐, and 4‐up, have been considered. In addition two types of inclusion complexes, cis and trans orientations, are also considered for each estrogen. In the cis structure the SBE group of the cyclodextrin and the phenol group of the estrogen are on the same side, while in the trans structure the two groups are on opposite sides. The objective of the present study is to perform PM3 (Parametric Method 3) semiempirical molecular orbital calculations on these six inclusion complexes (12 different orientations) for each SBE[4]‐β‐CD to correlate the migration order with their relative stability. Theoretical calculations have shown that only when SBE groups are perpendicular to the axis of CD (0‐up arrangement), the cavity is open on both sides for incoming guest molecules. A correlation was observed between the total heats of formation for the cis and trans estrogen‐CD inclusion complexes of the same estrogen and the electrophoretic migration time although the relationship is not linear, suggesting that both orientations may occur simultaneously. In other two SBE[4]‐β‐CDs, the narrower side of the cavity is partially capped due to the formation of intra‐hydrogen bonds among three of the four SBE groups. Thus, a guest molecule can enter the cavity from the wide end of the cavity only. As a result, the estrogen molecules protrude from the cavity in most cases. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Simian varicella: a model for human varicella‐zoster virus infections
Authors: Gray Wayne L. 
Published: August 2004

AbstractSimian varicella virus (SVV) causes a natural varicella‐like disease in nonhuman primates. Epizootics of simian varicella occur sporadically in facilities housing Old World monkeys. SVV is antigenically and genetically related to varicella‐zoster virus (VZV), the etiologic agent of varicella (chickenpox) and herpes zoster (shingles) in humans. The SVV and VZV genomes are similar in size and structure, share 70%–75% DNA homology and are co‐linear with respect to gene organisation. Simian varicella is a highly contagious disease characterised by fever and vesicular skin rash and may progress to pneumonia and hepatitis. Infected monkeys may resolve the disease within 2 weeks although epizootics are sometimes associated with high morbidity and mortality. SVV, like VZV, establishes life‐long latent infection, as indicated by detection of viral DNA within neural ganglia. Subsequently, SVV may reactivate to cause secondary disease and spread of the virus to susceptible monkeys. The relatedness of VZV and SVV and the similarities in the clinical symptoms and pathogenesis of human and simian varicella make SVV infection of nonhuman primates an excellent animal model to investigate VZV pathogenesis and latency, and to evaluate potential antiviral strategies. Copyright © 2004 John Wiley & Sons, Ltd.
Viruses as adjuvants for autoimmunity: evidence from Coxsackievirus‐induced myocarditis
Authors: Fairweather DeLisa , Frisancho‐Kiss Sylvia , Rose Noel R. 
Published: August 2004

AbstractAdjuvants historically are considered to stimulate immune responses ‘non‐specifically’. Recently, a renewed understanding of the critical role of innate immunity in influencing the development of an adaptive immune response has led researchers to a better understanding of ‘the adjuvant effect’. Although innate immune cells do not respond to specific antigenic epitopes on pathogens, they do produce restricted responses to particular classes of pathogens via pattern recognition receptors such as Toll‐like receptors (TLR). Coxsackievirus infection was found to upregulate TLR4 on mast cells and macrophages immediately following infection. Although both susceptible and resistant mice produce a mixture of Th1 and Th2 cytokines, susceptible mice have increased levels of key proinflammatory cytokines, increased numbers of mast cells, and go on to develop chronic autoimmune heart disease. TLR4 signalling also increases acute myocarditis and proinflammatory cytokines in the heart. Many similarities are described in the pathogenesis of Coxsackievirus and the adjuvant‐induced model of myocarditis including upregulation of particular TLRs and cytokines soon after inoculation. Recent findings suggest that mast cell activation by viruses or adjuvants may be important in initiating autoimmune disease. Copyright © 2004 John Wiley & Sons, Ltd.
Directed graphs, Hamiltonicity and doubly stochastic matrices
Authors: Borkar Vivek S. , Ejov Vladimir , Filar Jerzy A. 
Published: August 2004

AbstractWe consider the Hamiltonian cycle problem embedded in singularly perturbed (controlled) Markov chains. We also consider a functional on the space of stationary policies of the process that consists of the (1,1)‐entry of the fundamental matrices of the Markov chains induced by the same policies. In particular, we focus on the subset of these policies that induce doubly stochastic probability transition matrices, which we refer to as the “doubly stochastic policies.” We show that when the perturbation parameter ϵ is sufficiently small the minimum of this functional over the space of the doubly stochastic policies is attained very close to a Hamiltonian cycle, provided that the graph is Hamiltonian. We also derive precise analytical expressions for the elements of the fundamental matrix that lend themselves to probabilistic interpretation as well as asymptotic expressions for the first diagonal element, for a variety of deterministic policies that are of special interest, including those that correspond to Hamiltonian cycles. © 2004 Wiley Periodicals, Inc. Random Struct. Alg., 2004
Burnout, stress and health of employees on non‐standard work schedules: a study of Canadian workers
Authors: Jamal Muhammed 
Published: August 2004

AbstractThis study examined the relationship between non‐standard work schedules (shift work and weekend work) and job burnout, stress and psychosomatic health problems among full‐time employed Canadians in a large metropolitan city on the east coast. Data were collected by means of a structured mail back questionnaire (N = 376). Employees involved with weekend work reported significantly higher emotional exhaustion, job stress and psychosomatic health problems than employees not involved with weekend work. Similarly, employees on non‐standard work shifts (other than fixed day shift, 9 a.m.–5 p.m.) reported significantly higher overall burnout, emotional exhaustion, job stress and health problems than employees on a fixed day shift. Results from two‐way ANOVA indicated that employees involved with weekend work and non‐fixed day shifts reported significantly higher emotional exhaustion and health problems than other employees. Implications of the findings are discussed for future researchers in light of employee well‐being and non‐standard work schedules. Copyright © 2004 John Wiley & Sons, Ltd.
Using consumer demands to bridge the gap between software engineering and usability engineering
Authors: Scholtz Jean , Morse Emile 
Published: August 2004

AbstractA number of efforts are being undertaken to integrate usability engineering and software engineering in the software‐development process. The majority of these integration efforts focus on software developers, usability engineers, or defining new processes. In this article, we report on an effort to involve the consumer of software by providing a mechanism, namely the common industry format (CIF), to formally request usability information on the software to be purchased. Copyright © 2004 John Wiley & Sons, Ltd.
The usability design process – integrating user‐centered systems design in the software development process
Authors: Göransson Bengt , Gulliksen Jan , Boivie Inger 
Published: August 2004

AbstractThis article reviews current efforts in bridging the gaps between software engineering and Human–Computer Interaction (HCI) and describes some critical issues that must be resolved in order to reconcile some of the differences between the two fields. We argue that user‐centered systems design (UCSD) must be tightly integrated in the software development process and suggest the usability design process as a way of doing this. The usability design process is a UCSD approach for developing usable interactive systems, combining usability engineering with interaction design, and emphasizing extensive active user involvement throughout the iterative process. We outline the usability design process and illustrate the steps in the process with examples from real‐life design cases. Finally, we provide an example of how the usability design process can be implemented in a commercial software‐development process, Rational Unified Process™ (RUP). Copyright © 2004 John Wiley & Sons, Ltd.
Long‐term prenatal hypoxia alters maturation of brain catecholaminergic systems and motor behavior in rats
Authors: Perrin David , Mamet Julie , Scarna Hélène , Roux Jean Christophe , Bérod Anne , Dalmaz Yvette 
Published: August 2004

AbstractIn order to determine the influence of long‐term prenatal hypoxia on the maturation of the brain catecholaminergic structures involved in motor and cognitive functions, pregnant rats were subjected to hypoxia (10% O2) from the 5th to 20th day of gestation. The in vivo activity of tyrosine hydroxylase (TH), the rate‐limiting enzyme in catecholamine biosynthesis, was assessed, by accumulation of L‐DOPA after i.p. administration of NSD‐1015, in the motor cortex areas, the hippocampus, and the striatum at birth and at the 3rd, 7th, 14th, 21st, and 68th postnatal days. The motor reactivity to novelty and the circadian motor activity were measured at the 21st and 68th postnatal days. Exposure to prenatal hypoxia strongly altered the developmental pattern of in vivo TH activity in restricted noradrenergic terminals of the brain. In the 21‐day‐old prenatal hypoxic rats, the TH activity was reduced by 80% in the motor cortex areas and by 43% in the hippocampus, compared to control rats, while no differences could be detected in the striatum. Compared to control rats, the prenatal hypoxic pups exhibited a higher motor reactivity to novelty and a nocturnal motor hypoactivity at the 21st postnatal day. The neurochemical and behavioral alterations were no longer observed at the 68th postnatal day. The altered in vivo TH activity in the young rats might be part of the neural mechanisms contributing to the motor behavioral impairments induced by prenatal hypoxia. Long‐term prenatal hypoxia could be linked to the development of psychopathologies that can be detected in infancy. Synapse 54:92–101, 2004. © 2004 Wiley‐Liss, Inc.
Binding characteristics of high‐affinity dopamine D2/D3 receptor agonists, 11C‐PPHT and 11C‐ZYY‐339 in rodents and imaging in non‐human primates by PET
Authors: Mukherjee Jogeshwar , Narayanan Tanjore K. , Christian Bradley T. , Shi Bingzhi , Yang Zhi‐Ying 
Published: August 2004

AbstractWe have evaluated the in vitro autoradiographic binding characteristics and in vivo brain distribution of two high‐affinity dopamine D2/D3 receptor agonists, (±)‐2‐(N‐phenethyl‐N‐1′‐11C‐propyl)amino‐5‐hydroxytetralin (11C‐PPHT) and (±)‐2‐(N‐cyclohexylethyl‐N‐1′‐11C‐propyl)amino‐5‐hydroxytetralin (11C‐ZYY‐339) in rodents and in monkeys using positron emission tomography (PET). In vitro autoradiograms in rat brain slices with 11C‐PPHT and 11C‐ZYY‐339 revealed binding to dopaminergic regions in the striata, which was substantially (>90%) displaced by 10 μM sulpiride. Striatal binding was also removed in the presence of 5‐guanylylimidophosphate (Gpp(NH)p), indicative of binding of these radiotracers to the high‐affinity (HA) state. The results of in vivo studies in rats exhibited binding of the two radiotracers to the striata (striata/cerebellum approached 2 in 30 min). The regional selectivity to the striata was reduced by preadministration of haloperidol. PET studies in male rhesus monkeys using an ECAT EXACT HR+ scanner indicated localization of 11C‐PPHT and 11C‐ZYY‐339 in the striata and thalamus. Striata to cerebellum and thalamus to cerebellum ratios were low (1.5 and 1.3, respectively, at 30 min postinjection) for both 11C‐PPHT and 11C‐ZYY‐339, apparently due to the slower nonspecific clearance from cerebellum. These findings with 11C‐PPHT and 11C‐ZYY‐339 indicate the possibility of in vivo imaging of high‐affinity state of dopamine D2/D3 receptors in both the striata and the thalamus. Synapse 54:83–91, 2004. © 2004 Wiley‐Liss, Inc.
Reasoning from data: How students collect and interpret data in science investigations
Authors: Kanari Zoe , Millar Robin 
Published: August 2004

AbstractThis study explored the understandings of data and measurement that school students draw upon, and the ways that they reason from data, when carrying out a practical science inquiry task. The two practical tasks used in the study each involved investigations of the relationships between two independent variables (IVs) and a dependent variable (DV); in both tasks, one IV covaried with the DV, whereas the other did not. Each was undertaken by 10 students, aged 10, 12, and 14 years (total n = 60 students), working individually. Their actions were video‐recorded for analysis. In a subsequent interview, each student was asked to discuss and interpret data collected by two other students, undertaking a similar (but different) practical task, shown on a video‐recording. An analysis of the sample students' performance on the practical tasks and their interview responses showed few differences across task contexts, or with age, in students' reasoning, but significant differences in performance when investigating situations of covariation and non‐covariation. Few students in the sample displayed sufficient understanding of measurement error to deal effectively with the latter. Investigations of non‐covariation cases revealed, much more clearly than investigations of covariation cases, the students' ideas about data and measurement, and their ways of reasoning from data. Such investigations therefore provide particularly valuable contexts for teaching and research. © 2004 Wiley Periodicals, Inc. J Res Sci Teach 41: 748–769, 2004
Environmental isolation of Cryptococcus neoformans from an endemic region of HIV‐associated cryptococcosis in Thailand
Authors: Kuroki Misuzu , Phichaichumpon Cheseda , Yasuoka Akira , Chiranairadul Piphat , Chosa Toru , Sirinirund Petchsri , Miyazaki Taiga , Kakeya Hiroshi , Higashiyama Yasuhito , Miyazaki Yoshitsugu , Ishida Yutaka , Kohno Shigeru 
Published: August 2004

AbstractWe successfully isolated Cryptococcus neoformans from chicken faeces in suburban areas of Thailand. C. neoformans was isolated from 36/150 houses (24.0%) in the dry season and 6/150 (4.0%) in the rainy season. All environmental isolates were of serotype A. The high isolation rate of 24% from chicken faeces has never been reported previously. Our environmental study could probably explain the high incidence of cryptococcal meningitis in HIV patients in Thailand. Copyright © 2004 John Wiley & Sons, Ltd.
Characterization of Kluyveromyces lactis subtelomeric sequences including a distal element with strong purine/pyrimidine strand bias
Authors: Nickles Kristy , McEachern Michael J. 
Published: August 2004

AbstractTelomeres are the specialized structures at the ends of eukaryotic chromosomes and are composed of short T/G‐rich DNA repeats and the proteins that interact with them. Internal to telomeres are subtelomeric regions that are species‐specific and often repetitive. The yeast Kluyveromyces lactis has telomeric tracts of 10–20 copies of a 25 bp repeat, but the subtelomeric regions have not previously been characterized in detail. Here we have cloned and characterized subtelomeric regions from 10 of the 12 chromosome ends. The amount of sequence examined was 0.7–10 kb for each subtelomeric region. We have identified a K. lactis subtelomeric element, the R element, which has a strong purine/pyrimidine strand bias and extends for about 2 kb. Internal to the R element, we found extensive similarity that is shared among half of the chromosome ends reported here. This similarity appears to include three putative gene families, two of which are also subtelomeric in Saccharomyces cerevisiae. GenBank Accession Nos: P1, AY437818; P2, AY437819; P3, AY437820; P4, AY437821; P5, AY437822; P6, AY437823; P7‐5′, AY437824; P7‐3′, AY437825; P9‐5′, AY437826; P9‐3′, AY437827; P10, AY437828; P11‐5′, AY437829; P11‐3′, AY437830. Copyright © 2004 John Wiley & Sons, Ltd.
Modelling the dynamics of the yeast pheromone pathway
Authors: Kofahl Bente , Klipp Edda 
Published: August 2004

AbstractWe present a mathematical model of the dynamics of the pheromone pathways in haploid yeast cells of mating type MATa after stimulation with pheromone α‐factor. The model consists of a set of differential equations and describes the dynamics of signal transduction from the receptor via several steps, including a G protein and a scaffold MAP kinase cascade, up to changes in the gene expression after pheromone stimulation in terms of biochemical changes (complex formations, phosphorylations, etc.). The parameters entering the models have been taken from the literature or adapted to observed time courses or behaviour. Using this model we can follow the time course of the various complex formation processes and of the phosphorylation states of the proteins involved. Furthermore, we can explain the phenotype of more than a dozen well‐characterized mutants and also the graded response of yeast cells to varying concentrations of the stimulating pheromone. Copyright © 2004 John Wiley & Sons, Ltd.
Role of the N‐terminal region of Rap1p in the transcriptional activation of glycolytic genes in Saccharomyces cerevisiae
Authors: Mizuno Takayuki , Kishimoto Tomoko , Shinzato Tomoko , Haw Robin , Chambers Alistair , Wood Jason , Sinclair David , Uemura Hiroshi 
Published: August 2004

AbstractIn the yeast two‐hybrid system, the N‐terminal region of Rap1p was shown to interact with Gcr1p and Gcr2p. Disruption of gcr1 and/or gcr2 in the two‐hybrid reporter strain demonstrated that the interaction with Gcr1p does not require Gcr2p, whereas the interaction with Gcr2p is mediated through Gcr1p. Deletion of the N‐terminal region of Rap1p alone did not show a growth phenotype, but a growth defect was observed when this mutation was combined with a gcr2 deletion. The poor growth of the gcr1 null mutant was not affected further by the N‐terminal deletion of Rap1p, but the growth of gcr1 strains with mutations in the DNA binding region of Gcr1p was affected by the removal of the N‐terminal region of Rap1p. These results suggest that one function of the N‐terminal region of Rap1p, presumably the BRCT domain, is to facilitate the binding of Gcr1p to the promoter by a protein–protein interaction. Copyright © 2004 John Wiley & Sons, Ltd.