bluuebunny/crossref_metadata_2025 huggingface dataset:
Proteomic detection of COX-2 pathway-related factors in patients with adenomyosis
Authors: Zhang Jihua , Shi Luying , Duan Jingya , Li Minmin , Li Canyu
Published: January 2024

Background

Investigating the relationship between cyclooxygenase-2 (COX-2) pathway-related factors and clinical features in patients with adenomyosis by proteomics could provide potential therapeutic targets.

Methods

This study recruited 40 patients undergoing surgical hysterectomy and pathological diagnosis of adenomyosis, collected ectopic endometrial specimens, and recorded clinical data. The expression levels of COX-2 in ectopic uterus lesions were detected using the immunohistochemical (IHC) SP method. The 40 samples were then divided into a COX-2 low or high expression group. Five samples with the most typical expression levels were selected from each of the two groups and the differential proteins between the two groups were identified using label-free quantitative proteomics. WW domain-binding protein 2 (WBP2), interferon induced transmembrane protein 3 (IFITM3), and secreted frizzled-related protein 4 (SFRP4) were selected for further verification, and their relationships with COX-2 and clinical characteristics were analyzed.

Results

There were statistically significant differences in the expression of WBP2, IFITM3, and SFRP4 between the COX-2 low and high expression groups (P < 0.01). The expressions of COX-2, IFITM3, and SFRP4 were significantly correlated with dysmenorrhea between the two groups (P < 0.05), but not with uterine size or menstrual volume (P > 0.05). However, there was no significant correlation between the expression of WBP2 and dysmenorrhea, uterine size, and menstruation volume in both the high expression and low expression groups (P > 0.05).

Conclusions

COX-2, IFITM3, SFRP4, and WBP2 may be involved in the pathogenesis of adenomyosis. COX-2, IFITM3, and SFRP4 may serve as potential molecular biomarkers or therapeutic targets in dysmenorrhea in patients with early adenomyosis.
Prevalence of Anaemia in Individuals with Type 2 Diabetes: A Cross- sectional Study from a Tertiary Care Centre, Chennai, India
Authors: Babaria Prachi , Asirvatham Adlyne Reena , Shriraam Vanishree , Joseph Leena Dennis , Mahadevan Shriraam
Published: January 2024

Introduction: Anaemia is frequently observed in diabetes, affecting the quality of life and also contributing to the pathogenesis of microvascular complications. However, according to the literature, there have been no previous studies on the prevalence of Anaemia in Type 2 Diabetes (T2D) without Diabetic Kidney Disease (DKD) in the south Indian population. Aim: To estimate the prevalence of anaemia in T2D and study its association with glycaemic control and diabetes-related microvascular complications. Materials and Methods: The present study was a cross- sectional study that included 100 patients with T2D visiting the Department of Endocrinology at Sri Ramachandra Hospital, Chennai between June and September 2019. After obtaining informed consent, samples for complete blood count, Fasting Plasma Glucose (FPG), glycosylated haemoglobin (HbA1c), renal function tests, lipid profile, and urine microalbumin were collected from participants. Gestational diabetes, Type 1 Diabetes (T1D), and DKD on erythropoietin were excluded from this study. The test of Proportions was performed using the Chi- square test. Results: The mean age of the study population was 57.91±9.50 years. The overall prevalence of anaemia in the present study was 60%, and it was higher among women (p=0.023). Anaemia was also observed to be more common in those with poor glycaemic control (p=0.340) and in cases where at least one microvascular complication had occurred (p=0.796). Conclusion: Anaemia was observed in almost two-thirds of patients with T2D in this study. The prevalence of anaemia was higher in individuals with poor glycaemic control and diabetes- related microvascular complications.
Physiochemical Properties of Different Oil Media during Deep Fat Frying of Akara Chips
Authors: Nneji G. C. , Oluka S. I.
Published: January 2024

The specific objective is to determine the physiochemical characteristics of frying and fresh palm oil, groundnut oil and olive oil under deep fat frying condition at a temperature of 1200 Celsius in the production of akara chips derived from cowpea paste. Standard methods were used in determining physiochemical properties of the different oil samples. The research was carried out in the Department of Agricultural and Bioresources Engineering, Enugu State University of Science and Technology, Agbani Enugu State, Nigeria. The results showed that there was a significant (p< 0.05) variation among the three fresh (palm oil, groundnut oil and olive oil) and frying (palm oil, groundnut oil and olive oil) oil media respectively on the solidification point, iodine concentration, moisture content, melting point, fat levels and viscometric values. Frying reduced the moisture content and iodine value of palm, groundnut and olive oil than the non-frying, Fresh palm oil, groundnut oil and olive oil were high in visocometric and saponification values respectively.
Impact of Financial Deepening on Domestic Investment in Nigeria
Authors: Jolaiya Olatubosun Felix
Published: January 2024

This study investigated the impact of financial deepening on domestic investment in Nigeria. The time scope of the study covered the period 2005-2022. The response variable was domestic investment (DI) while the treatment variables were financial deepening indicators (broad money supply, private sector credits, and stock market capitalization. The specific objectives were to investigate the impact of credits to private sector on domestic investment in Nigeria; determine the impact of broad money supply on domestic investment in Nigeria; examine the impact of stock market capitalization on domestic investment in Nigeria; and ascertain the impact of monetary policy interest rate on domestic investment in Nigeria. The study adopted ex post facto research and employed the ARDL technique to analyze the data. Diagnostics and stability tests were applied (unit root, CUSUM and CUSUM of squares). the findings of the study indicated the series to be stationary but of mixed order 1(0) and 1(1); while the cointegration test showed evidence of long-run relationship. The long-run coefficients (of the ARDL) estimation indicated broad money supply has significant positive impact on domestic investment; private sector credit has significant positive impact on domestic investment; and the stock market capitalization has significant positive impact on domestic investment. However, the interest rate indicated to be negative on domestic investment. The policy implication of these findings impinges on government and authorities in the financial sector to develop a roadmap to further deepen the financial space to drive growth in domestic investment. Based on the findings, the study recommended that the financial authority should strategize to satisfy the demand for business investment funds by expanding the broad money supply and the private sector credits. Also, the monetary policy interest rate should be reviewed down in order to reverse its negative effect on investments.
Research on the Applications of High-impact Teaching Practice in Management Course
Authors: Qiu Yingying , Lu Wenjun , Yen Tsaifa (TF)
Published: January 2024

Higher education plays an important role in the cultivation of talents in our country, which requires colleges and universities to continuously explore the effect of education and teaching. High-impact teaching has changed the former “Teacher-centered” teaching model to “Student-centered”.  Through pre-class, in-class, after-class teaching arrangements, teachers help students become independent learners by individual and group learning. This paper explores the high-impact teaching model in the context of management from three aspects: learning goal, learning guarantees and learning evaluation, it is a useful exploration for the teaching reform of Management Course in colleges and universities under the new situation.
Social representations of the family caregiver about palliative care in terminal patient / Representações sociais do cuidador familiar sobre cuidados paliativos em paciente terminal
Authors: da Silva Silvio Éder Dias , Rodrigues Diego Pereira , de Oliveira Márcia Aparecida Ferreira , Ferreira Jaqueline Alves , dos Santos Jeferson Araújo , Rodrigues Diana Madeira
Published: January 2024

Objetivo: analisar as representações sociais dos cuidadores familiares sobre os cuidados paliativos em pacientes com doença grave, progressiva e que ameaça a continuidade de sua vida. Método: o estudo foi do tipo descritivo, utilizando abordagem qualitativa. Para a interpretação dos resultados foi empregado como aporte teórico a Teoria das Representações Sociais, criada por Serge Moscovici e Denise Jodelet. A pesquisa foi realizada com 30 cuidadores familiares de pacientes com câncer em estágio final de vida. A coleta foi feita por meio da entrevista semiestruturada e a técnica de análise temática. Resultados: após a análise dos dados, emergiram três categorias: o senso comum e o câncer; os cuidados paliativos, o doente e os cuidadores e os cuidadores e sua representação social. Considerações finais: as representações sociais do cuidador familiar possibilitaram identificar a verdadeira extensão das questões diárias no cotidiano profissional.
Tail‐dependence in stock‐return pairs
Authors: Fortin Ines , Kuzmics Christoph
Published: December 2002

The empirical joint distribution of return pairs on stock indices displays high tail‐dependence in the lower tail and low tail‐dependence in the upper tail. The presence of tail‐dependence is not compatible with the assumption of (conditional) joint normality. The presence of asymmetric tail‐dependence is not compatible with the assumption of a joint student‐t distribution. A general test for one dependence structure versus another via the profile likelihood is described and employed in a bivariate GARCH model, where the joint distribution of the disturbances is split into its marginals and its copula. The copula used in the paper is such that it allows for the existence of lower tail‐dependence and for asymmetric tail‐dependence, and is such that it encompasses the normal or t‐copula, depending on the benchmark tested. The model is estimated using bivariate data on a set of European stock indices. We find that the assumption of normal or student‐t dependence is easily rejected in favour of an asymmetrically tail‐dependent distribution. Copyright © 2002 John Wiley & Sons, Ltd.
Linking global circulation model synoptics and precipitation for western North America
Authors: Lapp Suzan , Byrne James , Kienzle Stefan , Townshend Ivan
Published: December 2002

Synoptic downscaling from global circulation models (GCMs) has been widely used to develop local and regional‐scale future precipitation scenarios under global warming. This paper presents an analysis of the linkages between the Canadian Centre for Climate Modelling and Analysis first version of the Canadian Global Coupled Model (CCCma CGCM1) 2000 model output and local/regional precipitation time series. The GCM 500 hPa geopotential heights were visually classified for synoptic patterns using a geographical information system. The pattern frequencies were statistically compared with historical data from Changnon et al. (1993. Monthly Weather Review 121: 633–647) for the winter period 1961–85. The CGCM1 synoptic frequencies compare favourably with the historical data, and they represent a substantial improvement over the 1992 Canadian Climate Centre Global Circulation Model synoptic climatology output. The CGCM1 output was used to forecast future winter precipitation scenarios for five geographically diverse climate stations in western North America. Copyright © 2002 Royal Meteorological Society.
Validation and results of a scale model of dew deposition in urban environments
Authors: Richards K. , Oke T. R.
Published: December 2002

There is growing interest in urban dew and its significance in questions of urban climate and air pollution deposition, but little research has been undertaken to study it. In this study, a generic, urban residential neighbourhood is modelled out‐of‐doors at a scale of 0.125, using three wooden houses (1.08 m tall), a concrete pavement (1.0 m in width), a grassed park (7.5 m in half‐width) and several small trees (up to 1.5 m tall). The thermal inertia of each house is inflated, according to the internal thermal mass (ITM) approach, so that nocturnal surface temperatures are conserved. First‐order validation was achieved through comparison with data collected at nearby full‐scale sites in Vancouver, BC, Canada. Moisture accumulation (measured by blotting on grass and by lysimetry) is found to be primarily controlled by nocturnal weather conditions and the intrinsic nature of each substrate, e.g. dewfall is abundant on nights with few clouds and light winds, and on surfaces such as grass and asphalt–shingle roofs, which cool rapidly after sunset. However, these responses are modified by location effects related to the net radiation balance of the surface, which itself is strongly linked to site geometry as expressed by sky view factor and whether surfaces are isolated from heat sources. The dominant mechanism is argued to be the systematic increase in longwave radiation loss that is associated with increased sky view. Results agree with those observed at the full scale and suggest that maps of sky view factor, and knowledge of dew at an open site, can potentially be used to create maps of dew distribution in urban and other complex environments. Copyright © 2002 Royal Meteorological Society.
Spatio‐temporal effects of El Niño events on rainfall and maize yield in Kenya
Authors: Amissah‐Arthur Abigail , Jagtap Shrikant , Rosenzweig Cynthia
Published: December 2002

The ability to predict rainfall variability a season in advance could have a major impact on the fragile Kenyan economy. The ability to benefit from climate prediction arises from the intersection of human vulnerability, climate predictability, and decision capacity. Africa may be a prime potential benefactor of seasonal climate forecasting. With this in mind, the link between El Niño‐related variability in rainfall at annual and seasonal scales and national‐level maize yield in Kenya was explored. The spatial and seasonal variations in El Niño influence on rainfall are highly inconclusive in Kenya except for some highland high rainfall sites and seasons. Significant event‐to‐event variability was observed, however, during the October–January (OJ) crop growing season during El Niño events. Increases in the OJ seasonal rainfall during El Niño events were reflected in the annual rainfall. While the mean change in rainfall between El Niño and neutral was positive during OJ season and annually, however, the change was negative during the March–June (MJ) season. El Niño effects were greater on rainfall in the second growing season (OJ) for the 1982–83 and 1997–98 El Niño compared with the 1986–87, 1987–88, 1991–92 events. Sites on the highland ecoregion recorded a significant increase in rainfall during El Niño events compared with neutral years. However, the 1987–88 El Niño had a significant effect on the MJ growing season rainfall with consequent positive influence on national maize yield. Furthermore, ‘super El Niños’ may give rise to larger rainfall responses than normal El Niños at some sites; the magnitude varies from site to site and the effect is not obvious at some sites. The results lead to the conclusion that all El Niños are not equal in terms of their regional manifestation. All this clearly indicates the need to address critical user needs of climate information in order to produce information that is useful. Copyright © 2002 Royal Meteorological Society.
Behavioral genetic approaches to visual system development and function in zebrafish
Authors: Neuhauss Stephan C.F.
Published: December 2002

The zebrafish is a recent vertebrate model system that shows great potential for a genetic analysis of behavior. Early development is extraordinarily rapid, so that larvae already display a range of behaviors 5 days after fertilization. In particular the visual system develops precociously, supporting a number of visually mediated behaviors in the larva. This provides the opportunity to use these visually mediated behaviors to screen chemically mutagenized strains for defects in vision. Larval optokinetic and optomotor responses have already been successfully employed to screen for mutant strains with defects in the visual system. In the adult zebrafish a visually mediated escape response has proved useful for screening for dominant mutations of the visual system. Here, I summarize visually mediated behaviors of both larval and adult zebrafish and their applicability for genetic screens, and present, the approaches and results of visual behavior carried out to date. © 2003 Wiley Periodicals, Inc. J Neurobiol 54: 148–160, 2003
Perchance to dream: Solving the mystery of sleep through genetic analysis
Authors: Shaw Paul J. , Franken Paul
Published: December 2002

Sleep has been identified in all mammals and nonmammalian vertebrates that have been critically evaluated. In addition, sleep‐like states have also been identified and described in several invertebrates. Despite this prevalence throughout the animal kingdom, the function of sleep remains a mystery. The completion of several genome sequencing projects has led to the expectation that fundamental aspects of sleep can be elucidated through genetic dissection. Indeed, studies in both the mouse and fly have begun to reveal tantalizing suggestions about the underlying principles that regulate sleep homeostasis. In this article we will review recent studies that have used genetic techniques to evaluate sleep in the fruit fly and the mouse. © 2003 Wiley Periodicals, Inc. J Neurobiol 54: 179–202, 2003
Functional genomics of neural and behavioral plasticity
Authors: Hofmann Hans A.
Published: December 2002

How does the environment, particularly the social environment, influence brain and behavior and what are the underlying physiologic, molecular, and genetic mechanisms? Adaptations of brain and behavior to changes in the social or physical environment are common in the animal world, either as short‐term (i.e., modulatory) or as long‐term modifications (e.g., via gene expression changes) in behavioral or physiologic properties. The study of the mechanisms and constraints underlying these dynamic changes requires model systems that offer plastic phenotypes as well as a sufficient level of quantifiable behavioral complexity while being accessible at the physiological and molecular level. In this article, I explore how the new field of functional genomics can contribute to an understanding of the complex relationship between genome and environment that results in highly plastic phenotypes. This approach will lead to the discovery of genes under environmental control and provide the basis for the study of the interrelationship between an individual's gene expression profile and its social phenotype in a given environmental context. © 2003 Wiley Periodicals, Inc. J Neurobiol 54: 272–282, 2003
Interaction of e. coli outer‐membrane protein A with sugars on the receptors of the brain microvascular endothelial cells
Authors: Datta Deepshikha , Vaidehi Nagarajan , Floriano Wely B. , Kim Kwang S. , Prasadarao Nemani V. , Goddard William A.
Published: December 2002

Esherichia coli, the most common gram‐negative bacteria, can penetrate the brain microvascular endothelial cells (BMECs) during the neonatal period to cause meningitis with significant morbidity and mortality. Experimental studies have shown that outer‐membrane protein A (OmpA) of E. coli plays a key role in the initial steps of the invasion process by binding to specific sugar moieties present on the glycoproteins of BMEC. These experiments also show that polymers of chitobiose (GlcNAcβ1‐4GlcNAc) block the invasion, while epitopes substituted with the L‐fucosyl group do not. We used HierDock computational technique that consists of a hierarchy of coarse grain docking method with molecular dynamics (MD) to predict the binding sites and energies of interactions of GlcNAcβ1‐4GlcNAc and other sugars with OmpA. The results suggest two important binding sites for the interaction of carbohydrate epitopes of BMEC glycoproteins to OmpA. We identify one site as the binding pocket for chitobiose (GlcNAcβ1‐4GlcNAc) in OmpA, while the second region (including loops 1 and 2) may be important for recognition of specific sugars. We find that the site involving loops 1 and 2 has relative binding energies that correlate well with experimental observations. This theoretical study elucidates the interaction sites of chitobiose with OmpA and the binding site predictions made in this article are testable either by mutation studies or invasion assays. These results can be further extended in suggesting possible peptide antagonists and drug design for therapeutic strategies. Proteins 2003;50:213–221. © 2002 Wiley‐Liss, Inc.
Distal heme pocket regulation of ligand binding and stability in soybean leghemoglobin
Authors: Kundu Suman , Hargrove Mark S.
Published: December 2002

Leghemoglobins facilitate diffusion of oxygen through root tissue to a bacterial terminal oxidase in much the same way that myoglobin transports oxygen from blood to muscle cell mitochondria. Leghemoglobin serves an additional role as an oxygen scavenger to prevent inhibition of nitrogen fixation. For this purpose, the oxygen affinity of soybean leghemoglobin is 20‐fold greater than myoglobin, resulting from an 8‐fold faster association rate constant combined with a 3‐fold slower dissociation rate constant. Although the biochemical mechanism used by myoglobin to bind oxygen has been described in elegant detail, an explanation for the difference in affinity between these two structurally similar proteins is not obvious. The present work demonstrates that, despite their similar structures, leghemoglobin uses methods different from myoglobin to regulate ligand affinity. Oxygen and carbon monoxide binding to a comprehensive set of leghemoglobin distal heme pocket mutant proteins in comparison to their myoglobin counterparts has revealed some of these mechanisms. The “distal histidine” provides a crucial hydrogen bond to stabilize oxygen in myoglobin but has little effect on bound oxygen in leghemoglobin and is retained mainly for reasons of protein stability and prevention of heme loss. Furthermore, soybean leghemoglobin uses an unusual combination of HisE7 and TyrB10 to sustain a weak stabilizing interaction with bound oxygen. Thus, the leghemoglobin distal heme pocket provides a much lower barrier to oxygen association than occurs in myoglobin and oxygen dissociation is regulated from the proximal heme pocket. Proteins 2003;50:239–248. © 2002 Wiley‐Liss, Inc.
Structure of human aldose reductase holoenzyme in complex with Statil: An approach to structure‐based inhibitor design of the enzyme
Authors: El‐Kabbani Ossama , Ramsland Paul , Darmanin Connie , Chung Roland P.‐T. , Podjarny Alberto
Published: December 2002

Aldose reductase, a monomeric NADPH‐dependent oxidoreductase, catalyzes the reduction of a wide variety of aldehydes and ketones to their corresponding alcohols. The X‐ray structure of human aldose reductase holoenzyme in complex with statil was determined at a resolution of 2.1 Å. The carboxylate group of statil interacted with the conserved anion binding site located between the nicotinamide ring of the coenzyme and active site residues Tyr48, His110, and Trp111. Statil's hydrophobic phthalazinyl ring was bound in an adjacent pocket lined by residues Trp20, Phe122, and Trp219, with the bromo‐fluorobenzyl group penetrating the “specificity” pocket. The interactions between the inhibitor's bromo‐fluorobenzyl group and the enzyme include the stacking against the side‐chain of Trp111 as well as hydrogen bonding to residues Leu300 and Thr113. Based on the model of the ternary complex, the program GRID was used in an attempt to design novel potential inhibitors of human aldose reductase with enhanced binding energies of the complex. Molecular modeling calculations suggested that the replacement of the fluorine atom of statil with a carboxylate functional group may enhance the binding energies of the complex by 33%. Proteins 2003;50:230–238. © 2002 Wiley‐Liss, Inc.
Improved up‐and‐down designs for phase I trials
Authors: Ivanova Anastasia , Montazer‐Haghighi Aliakbar , Mohanty Sri Gopal , D. Durham Stephen
Published: December 2002

We consider several designs from the family of up‐and‐down rules for the sequential allocation of dose levels to subjects in a dose–response study. We show that an up‐and‐down design can be improved by using more information than the most recent response. For example, the k‐in‐a‐row rule uses up to the k most recent responses. We introduce a new design, the Narayana rule, which uses a local estimate of the probability of toxicity calculated from all previous responses. For the Narayana rule, as the sample size gets large, the probability of assignment goes to zero for dose levels not among the two (or three) closest to the target. Different estimators of the target dose are compared. We find that the isotonic regression estimator is superior to other estimators for small to moderate sample sizes. Copyright © 2003 John Wiley & Sons, Ltd.
Bilingual legal document retrieval and management using XML
Authors: Luk R. W. P. , T'sou B. K. Y. , Lai T. B. Y. , Kwong O. O. Y. , Chik F. C. Y. , Cheung L. Y. L.
Published: December 2002

In certain bilingual and multi‐lingual societies, translated legal documents are as important as the original legal documents because they have the same legal status as the originals. However, there is little reported work on the retrieval and management of bilingual legal documents. We describe the design and development of a bilingual document retrieval and management prototype, called ELDoS, which is used by court interpreters and judges from the Hong Kong Judiciary. Since the speed of retrieval is a major concern for user acceptance, and therefore for widespread deployment of the system, the architecture of the prototype is designed to balance the workload of the client and server. Extensible Markup Language (XML) is used to mark up the bilingual legal documents for a variety of document retrieval and management tasks. XML enables the use of XML Stylesheet Language Transformation (XSLT) to align bilingual data in the client, instead of the server, and improve alignment speed linearly with respect to the size of the document, using a high‐end PC, when the server has no concurrent access. The design of the interface was continually improved after extensive consultation with court interpreters and after the user acceptance tests. In our evaluation, the facilities for highlighting translated terms have a macro‐averaged precision of 90+% and a macro‐average recall of 80+%, which were considered acceptable by our users. We believe that the experience in the design and development of this prototype is applicable to other language pairs as well as to other domains. Copyright © 2002 John Wiley & Sons, Ltd.
A new rapid radiological procedure for routine teratological use in bone ossification assessment: A supplement for staining methods
Authors: Burdan Franciszek , Rozylo‐Kalinowska Ingrid , Katarzyna Rozylo T. , Chahoud Ibrahim
Published: December 2002

Background

Presently, bone ossification is assessed by the study of single‐stained fetal bones (alizarin red‐S) or double‐stained bones and cartilaginous structures (alcian blue followed by alizarin red‐S). Both methods, especially double‐staining, are labor‐intensive, time‐consuming, and provide qualitative information regarding skeleton ossification. Quantitative evaluation of ossification is more difficult and is usually based on determination of calcium and other minerals in the bone by means of atomic absorption spectrometry. Here we introduce a simple new method that allows quantitative determination of skeleton ossification before routine staining examination.

Methods

Fetuses delivered by laparotomy on the 16th and 21st day of gestation as well as 1‐day‐old rat pups were examined. The fetuses and pups were prenatally subcutaneously exposed to sodium valproate or to physiological saline. Lateral, prone, and supine digital radiograms of each fetus were taken using the Digora‐Soredex digital radiography system and the Planmeca Intra intraoral X‐ray machine. According to the best visualization, the data concerning vertebra were analyzed. All the fetuses were then routinely double‐stained using alcian blue and alizarin red‐S.

Results

Malformations of axial skeleton (rib, sternum, and thoracic and sacral vertebra) were found in valproate‐treated groups. Unlike cartilage malformations, the bone changes were detected in similar frequency in radiological and staining methods. Differences in densities according to the degree of ossification in the vertebral arches and bodies at different levels of the vertebral column, between drug‐treated and negative control groups were noted.

Conclusions

The preliminary results suggest that digital radiography examination is a useful method in determining delaying of skeleton ossification not detectable by other methods. It balances qualitative and quantitative aspects of the presently used methods and is also simple, objective, fast, and relatively inexpensive. Teratology 66:315–325, 2002. © 2002 Wiley‐Liss, Inc.
A programming environment for behavioural animation
Authors: Devillers Frédéric , Donikian Stéphane , Lamarche Fabrice , Taille Jean‐François
Published: December 2002

Behavioural models offer the ability to simulate autonomous agents like organisms and living beings. Psychological studies have shown that human behaviour can be described by a perception–decision–action loop, in which the decisional process should integrate several programming paradigms such as real time, concurrency and hierarchy. Building such systems for interactive simulation requires the design of a reactive system treating flows of data to and from the environment, and involving task control and preemption. Since a complete mental model based on vision and image processing cannot be constructed in real time using purely geometrical information, higher levels of information are needed in a model of the virtual environment. For example, the autonomous actors of a virtual world would exploit the knowledge of the environment topology to navigate through it. Accordingly, in this paper we present our programming environment for real‐time behavioural animation which is compounded of a general animation and simulation platform, a behavioural modelling language and a scenario‐authoring tool. Those tools has been used for different applications such as pedestrian and car driver interaction in urban environments, or a virtual museum populated by a group of visitors. Copyright © 2002 John Wiley & Sons, Ltd.
Auroral current‐voltage relation
Authors: Rönnmark Kjell
Published: December 2002

The acceleration of electrons into discrete auroras by parallel electric fields is intimately connected with the auroral current‐voltage relation. Kinetic and fluid models are in this study combined to derive a relation between auroral currents and field‐aligned electric fields. The derivation is based on the assumption that the plasma density along the flux tube is a parameter, which is independent of the field‐aligned potential drop. On the other hand, recent observations suggest that the density in the acceleration region is an important parameter, which strongly influences the field‐aligned electric field. Knight's model, leading to the widely accepted linear current‐voltage relation, predicts an increase of the density in the acceleration region in proportion to the square root of the voltage, which seems incompatible with these observations. However, the observed correlation between large potential drops and deep auroral cavities is consistent with the results of this study, which shows that the voltage is inversely proportional to the square of the density in the acceleration region. Our model also predicts that the voltage is proportional to the square of the current.
Modeling the Martian dust cycle, 1. Representations of dust transport processes
Authors: Newman Claire E. , Lewis Stephen R. , Read Peter L. , Forget François
Published: December 2002

A dust transport scheme has been developed for a general circulation model of the Martian atmosphere. This enables radiatively active dust transport, with the atmospheric state responding to changes in the dust distribution via atmospheric heating, as well as dust transport being determined by atmospheric conditions. The scheme includes dust lifting, advection by model winds, atmospheric mixing, and gravitational sedimentation. Parameterizations of lifting initiated by (1) near‐surface wind stress and (2) convective vortices known as dust devils are considered. Two parameterizations are defined for each mechanism and are first investigated offline using data previously output from the non‐dust‐transporting model. The threshold‐insensitive parameterizations predict some lifting over most regions, varying smoothly in space and time. The threshold‐sensitive parameterizations predict lifting only during extreme atmospheric conditions (such as exceptionally strong winds), so lifting is rarer and more confined to specific regions and times. Wind stress lifting is predicted to peak during southern summer, largely between latitudes 15° and 35°S, with maxima also in regions of strong slope winds or thermal contrast flows. These areas are consistent with observed storm onset regions and dark streak surface features. Dust devil lifting is also predicted to peak during southern summer, with a moderate peak during northern summer. The greatest dust devil lifting occurs in early afternoon, particularly in the Noachis, Arcadia/Amazonis, Sirenum, and Thaumasia regions. Radiatively active dust transport experiments reveal strong positive feedbacks on lifting by near‐surface wind stress and negative feedbacks on lifting by dust devils.
SPHERICAL COLLAPSE WITH HEAT FLOW AND WITHOUT HORIZON
Authors: BANERJEE A. , CHATTERJEE S. , DADHICH N.
Published: December 2002

We present a class of solutions for a heat conducting fluid sphere, which radiates energy during collapse without the appearance of horizon at the boundary at any stage of the collapse. A simple model shows that there is no accumulation of energy due to collapse since it radiates out at the same rate as it is being generated.
QUANTIZATION OF SINGULAR SYSTEMS WITH SECOND-ORDER LAGRANGIANS
Authors: MUSLIH SAMI I.
Published: December 2002

The path integral formulation of singular systems with second-order Lagrangians is constructed by using the canonical method. The path integral quantization of Podolsky electrodynamics is studied.
QCD CORRECTIONS IN Γsl(B)
Authors: URALTSEV NIKOLAI
Published: December 2002

Short-distance expansion of the total semileptonic B widths is reviewed for the OPE-conformable scheme employing low-scale running quark masses. The third- and fourth-order BLM corrections are given and the complete resummation of the BLM series presented. The effect of higher perturbative orders with running quark masses is found to be very small. Numerical consequences for |Vcb| are addressed.
ANTIMONY DIFFUSION IN SILICON GEMANIUM ALLOYS UNDER POINT DEFECT INJECTION
Authors: DAN AIHUA , WILLOUGHBY ARTHUR F. W. , BONAR JANET M. , MCGREGOR BARRY M. , DOWSETT MARK G. , MORRIS RICHARD J. H.
Published: December 2002

Antimony diffusion in in-situ doped strained Si 0.9 Ge 0.1 epitaxial layers, subjected to point defects injection by rapid thermal anneal in oxygen atmosphere, was investigated as a function of temperature at range from 890°C to 1000°C. In this work, the effect of point defect injection on the diffusion of antimony in silicon and silicon-germanium alloys has confirmed the predominant mechanism for diffusion of Sb in Si and SiGe to be vacancy mediated. Diffusivities were obtained using computer simulations. Activation energies were calculated while the diffusivity of antinomy in SiGe under point defect injection as a function of temperature was presented.
C-V AND DLTS CHARACTERIZATION OF RAPID THERMAL OXIDES ON Si0.887Ge0.113 AND Si0.8811Ge0.113C0.0059 ALLOYS
Authors: FENG W. , CHOI W. K. , BERA L. K. , MI J. , YANG C. Y.
Published: December 2002

Capacitance versus voltage (C-V) and deep level transient spectroscopy (DLTS) characterization was performed on rapid thermal oxides (RTO) on Si 0.887 Ge 0.113 and Si 0.8811 Ge 0.113 C 0.0059 alloys. A high interface trap density (~ 1012 eV -1 cm -2) and a high apparent doping level were obtained for the SiO 2/ Si 0.8811 Ge 0.113 C 0.0059 samples. The C-V results at different temperatures showed that the high apparent doping levels of the SiO 2/ Si 0.8811 Ge 0.113 C 0.0059 samples might be due to the formation of SiC-related defects introduced by the high temperature oxidation process.
HETERO-GROWTH OF (100) ORIENTATED ZNO FILMS ON SILICON BY SS-CVD
Authors: LU JIAN-GUO , YE ZHI-ZHEN , CHEN HAN-HONG , HUANG JING-YUN , ZHAO BING-HUI
Published: December 2002

ZnO films with (100) preferred orientation are reported for the first time. ZnO films were synthesized on Si(100) substrate by solid-source chemical vapor deposition (SS-CVD) using zinc acetate dihydrate (solid) as a precursor. The structural properties were investigated by X-ray diffraction and atomic force microscopy. Results show that a lower growth temperature and a higher deposition rate will facilitate the formation of (100) texture. The texture coefficient for (100) plane is 3.28.
EFFECT OF SUBSTRATE TEMPERATURE ON THE PROPERTIES OF Zn1-xMgxO FILMS ON SILICON
Authors: LU ZOU , YE ZHIZHEN , HUANG JINGYUN , ZHAO BINGHUI
Published: December 2002

Zn 1-x Mg x O films were grown on silicon (Si) at various substrate temperatures by pulsed laser deposition (PLD). The structural, surface morphology, composition and photoluminescent properties of the films as functions of substrate temperature were studied. When the substrate temperature was at 650°C, the crystalline quality was the best, and the grain size of the film was largest. These films showed ultraviolet photoluminescence at room temperature. The near-band-edge (NBE) emission peak of the Zn 1-x Mg x O film deposited at 600°C exhibited a larger blue shift (0.40eV) than that of the film deposited at 500°C (0.33 eV). The ratio of near-band-edge (NBE) to defect level (DL) peak intensity was as large as 159.
STUDY ON OPTICAL BAND GAP OF BORON-DOPED NC-SI:H FILM
Authors: WEI WENSHENG , WANG TIANMIN , ZHANG CHUNXI , LI GUOHUA , HAN HEXIANG , DING KUN
Published: December 2002

The optical band gap ( E g ) of the boron (B)-doped hydrogenated nano-crystalline silicon (nc-Si:H) films fabricated using plasma enhanced chemical vapor deposition (PECVD) was investigated in this work. The transmittance of the films were measured by spectrophotometric and the E g was evaluated utilizing three different relations for comparison, namely: α h ν= C ( h ν- E g )3, α h ν= B 0( h ν- E g )2, α h ν= C 0( h ν- E g )2. Result showed that E g decreases with the increasing of Boron doping ratio, hydrogen concentration, and substrate's temperature (Ts), respectively. E g raises up with rf power density ( P d ) from 0.4 5W.cm -2 to 0.60 w.cm -2 and then drops to the end. These can be explained for E g decreases with disorder in the films.
CHARACTERIZATION OF SEMICONDUCTOR QUANTUM DOTS
Authors: WANG J. N. , YANG C. L. , WANG S. H. , GUO L. , YANG S. H. , SOU I. K. , GE W. K.
Published: December 2002

The applications of various optical and electrical characterization techniques to the study of semiconductor quantum dots (QDs) are summarized. Photoconductivity enhancement effect in CdS-PVK nanocomposite is studied by optical absorption, photoluminescence (PL), photoconductivity spectroscopy, and time-resolved PL. It is found that the photoconductivity of the composite is greatly enhanced in comparison with that of a simple mixture of CdS nano-particles and PVK. PL spectra have shown that luminescence from PVK is dramatically quenched by the incorporation of a low density of CdS particles. Time-resolved spectra reveal that the decay of the PL from the dots of the composite in much longer than that in the simple mixture. These have been attributed to a fast carrier transfer mechanism between CdS QDs and PVK matrix. In addition, optical properties of PVP-capped ZnO QDs are investigated in details. Typical PL spectra of PVP-capped ZnO QDs consist of a sharp UV peak located at about 3.45 eV and a broad green emission band centered at 2.34 eV. At certain Zn 2+/ PVP ratios the green emission band is quenched and only strong UV emission remains. This effect is attributed to the surface modification of ZnO quantum dots with PVP. We are able to associate the UV emission from ZnO QDs to localized states by applying temperature and excitation power dependent PL. Finally, the electronic level of molecular beam epitaxy grown self-organized ZnSe QDs embedded in ZnS is determined by applying PL, capacitance-voltage measurement, and deep level transient spectroscopy.
LOW-VOLTAGE AND ULTRA-LOW-VOLTAGE SCANNING ELECTRON MICROSCOPY OF SEMICONDUCTOR SURFACES AND DEVICES
Authors: LIU JINGYUE
Published: December 2002

Low-voltage scanning electron microscopy (LV-SEM) enables us to directly examine non-conducting materials with high spatial resolution. Although use of ultra-low-energy electrons can provide further advantages for characterizing delicate samples, lens aberrations rapidly deteriorates the image resolution. The combined use of a retarding field and the probe-forming lens system can improve the image resolution for electrons with very low energies. In commercially available FEG-SEMs, the retarding field can simply be constructed by applying a negative potential to the specimen. Interesting contrast variations have been observed in ultra-low-voltage SEM images. In this short communication, we discuss the application of LV-SEM to examining semiconductor devices and also the recent development of the ultra-low-voltage SEM technique.
MICRO-RAMAN STUDY OF SURFACE ALTERATIONS IN InGaAs AFTER THERMAL ANNEALING TREATMENTS
Authors: HERNÁNDEZ S. , CUSCÓ R. , ARTÚS L. , BLANCO N. , MÁRTIL I. , GONZÁLEZ-DÍAZ G.
Published: December 2002

We present a micro-Raman study of alterations in InGaAs/InP epilayers after rapid thermal annealing. Defects consisting of protruding material with typical dimensions of a few microns can be observed on the surface of the annealed samples. Micro-Raman measurements on these defects show that they consist of In x Ga 1-x P alloys, suggesting that phosphorus diffusion from the InP substrate occurs during the RTA cycle. The defect-free region of the epilayer is also altered leading to the formation of an In 1-x Ga x As 1-y P y quaternary alloy.
MONTE CARLO CALCULATION OF THE ENERGY DISTRIBUTION OF BACKSCATTERED ELECTRONS
Authors: DING Z. J. , TANG X. D. , LI H. M.
Published: December 2002

The full energy distribution of backscattered electrons from elastic peak down to true secondary electron peak has been calculated by a Monte-Carlo simulation method by including cascade secondary electrons production. The simulation method is based on the use of a dielectric function for describing electron inelastic scattering and secondary excitation, and the use of Mott cross section for electron elastic scattering. This calculation reproduces well the backscattering background observed in the direct mode of AES. The calculated absolute electron yields have been compared with the available experimental data. The simulation has indicated that, due to the effect of the elastic scattering differential cross section and detection solid angles, the shape of the energy distribution measured with a cylindrical mirror analyzer may differ from the overall energy spectrum of emitted electrons.
THE DETERMINATION OF SP3 FRACTION IN TETRAHEDRAL AMORPHOUS CARBON FILMS BY RAMAN AND X-RAY PHOTOELECTRON SPECTROSCOPY
Authors: CHEN DIHU , JING G. Y. , WEI AIXIANG
Published: December 2002

Tetrahedral amorphous carbon films have been prepared by magnetic filtered plasma deposition system. The samples were deposited with negative bias voltage V b range from +20 V to -95 V. The relative fraction of sp 3-bonded carbon in these films was qualitatively and quantitatively estimated by a fitting of the Raman and XPS spectra, respectively. Raman results show that the sp 3 fraction of the films deposited in the range from -10 V to -50 V was estimated to be more than 80%. The C 1s spectra were consistently decomposed into the two gaussian components, one is at 284.4±0.1 eV corresponding to sp 2-hybridized bonds, and another is at 285.2±0.1 eV corresponding to sp 3-hybridized bond. The sp 3 content can be quantitatively calculated from the integrated area of the respective gaussian peak divided by the total area of the spectra. The comparison of XPS with Raman analysis, the trend of qualitative variation of sp 3 content with V b is in agreement. We concluded that XPS analysis is a useful method for quantitatively calculating sp 3 content in hydrogen-free tetrahedral amorphous carbon films.
SYMMETRY IN THE DIAGONAL SELF-ASSEMBLED InAs QUANTUM WIRE ARRAYS ON InP SUBSTRATE
Authors: WU J. , ZENG Y. P. , CUI L. J. , ZHU Z. P. , WANG B. X. , WANG Z. G.
Published: December 2002

Diagonal self-assembled InAs quantum wire (QWR) arrays with the stacked InAs/In 0.52 Al 0.48 As structure are grown on InP substrates, which are (001)-oriented and misoriented by 6° towards the [100] direction. Both the molecular beam epitaxy (MBE) and migration enhanced epitaxy (MEE) techniques are employed. Transmission electron microscopy reveals that whether a diagonal InAs QWR array of the stacked InAs/InAlAs is symmetrical about the growth direction or not depends on the growth method as well as substrate orientation. Asymmetry in the diagonal MEE-grown InAs QWR array can be ascribed to the influence of surface reconstruction on upward migration of adatoms during the self-assembly of the InAs quantum wires.
TENSILE DEFORMATION OF COPPER SINGLE CRYSTALS BY SIMULATION USING X-RAY LANG METHOD AND MOLECULAR DYNAMICS
Authors: DOYAMA MASAO , KOGURE Y. , NOZAKI T. , KATO Y.
Published: December 2002

Simulations were performed to model the response of a copper rectangular parallelepiped single crystal with a notch to tensile deformation. Partial dislocations were created near the tip of the notch as we expected. It is hard to see where the dislocations were created by just looking at the displaced positions of atoms, but the creation of dislocations was easily observed by a simulation of X-ray Lang method. Before creation of dislocations, some indication was quite clearly shown. Laue patterns during tensile deformation were also simulated.
PHOTOCURRENT STUDY OF ERBIUM DELTA-DOPED InP GROWN BY ORGANOMETALLIC VAPOR PHASE EPITAXY
Authors: PECHARAPA W. , NUKEAW J.
Published: December 2002

The photocurrent of erbium delta-doped InP grown by organometallic vapor phase epitaxy was observed at room temperature. The clear PC spectra of doped samples reflect the high quality formation of ErP quantum structure in InP. The PC spectra of doped sample with different Er exposure duration show that the total number of ErP islands increase with increasing exposure time, reflected in the sharper PC spectra. When applying an electric field, the spectra of the doped sample exhibit significant shift with increasing field.
STUDY OF THE THERMAL STABILITY OF AN ORGANIC POLYMER LOW-K MATERIAL
Authors: LU DONG , XING ZHENXIANG
Published: December 2002

Polymer low-k materials have been regarded as one of the most promising candidates as interconnect insulator with copper metallization. One of the major problems associated with polymer materials is their poor thermal stability. In this paper, thermal stability of an aromatic hydrocarbon low-k material was studied using TGA, FTIR and thermal desorption-GC-MS techniques. The material is thermally stable at temperatures up to 430°C. At higher temperatures, thermal decomposition of the low-k material is pronounced and the major outgassing species are aromatic compounds and carbon dioxide.