bluuebunny/crossref_metadata_2025 huggingface dataset:
Produção do leite: a relação entre os fatores determinantes do custo de produção e os preços pagos ao produtor
Authors: Cristo-Diniz Poliana Cristina de Oliveira , Neto Edilberto Batista Mendes , Tavares Marcelo
Published: November 2022

O Brasil ostenta um dos maiores rebanhos de bovinos do mundo e a pecuária leiteira representa uma atividade econômica de grande relevância. A partir de dados do IBGE (2012), Bragagnolo et al. (2011) afirmam ainda que, o custo médio de produção de leite do Brasil é um dos menores do mundo, sendo inferior até mesmo que ao dos Estados Unidos. Apesar disso, muitos produtores rurais reclamam dos custos de produção nas diversas regiões do país, afirmando existirem grandes oscilações no preço do leite ofertado afirmando existirem grandes oscilações no preço do leite ofertado pela indústria e nos custos produtivos. Portanto, o objetivo deste artigo foi avaliar qual o impacto das oscilações dos componentes do custo de produção leiteira no valor pago pelo leite in natura aos pecuaristas. Para tanto, foram coletados dados secundários nas bases de dados no sitio da CONAB e da CEPEA/Esalq/USP. Foram coletados os preços pagos pela soja e pelo milho, assim como os preços pagos pelo leite in natura. O período coletado foi de janeiro de 2009 a dezembro de 2012 devido à disponibilidade de dados. Os dados foram analisados por meio de estatística descritiva, teste de normalidade dos dados, correlação e regressão linear múltipla. Nos resultados encontrados, com exceção da Bahia, todos os demais modelos propostos, evidenciaram que o insumo milho influencia o preço do leite in natura pago ao produtor em todos os demais Estados e o insumo soja não. No caso da Bahia, a pesquisa mostrou que os dois insumos, milho e soja, influenciam o preço pago ao produtor de leite. A análise de regressão corrobora então, a análise de correlação, evidenciando que o insumo milho influencia de forma relevante o preço pago ao produtor de leite nos sete estados pesquisados.
Previsão de preços das commodities agrícolas: uma revisão bibliométrica sobre modelos
Authors: Porto Bruno Matos
Published: November 2022

Objetivo - Identificar a lacuna de pesquisa sobre modelos de previsão aplicados nos preços das commodities agrícolas e mostrar as principais tendências da previsão. Desenho/ metodologia/abordagem - A análise bibliométrica possibilitou identificar a lacuna científica e gerou resultados quantitativos e tendências. Resultados - Os resultados mostraram que as abordagens ARIMA e redes neurais são os modelos mais utilizados na previsão de preços de commodities agrícolas, no entanto, o modelo ARIMA não tem gerado previsões superiores em comparação aos algoritmos de aprendizado de máquina (ML) e modelos híbridos. As redes neurais são mais precisas para prever preços de commodities agrícolas do que os modelos econométricos. Os modelos híbridos de IA geram predições com melhores níveis de acurácia em comparação aos métodos estatísticos tradicionais ARIMA, modelos individuais e redes neurais em que o desempenho de previsão dos modelos híbridos são melhores do que os dos modelos únicos. É uma tendência a abordagem de modelos híbridos para prever preços de commodities agrícolas em pesquisas futuras. Implicações de pesquisa, práticas e sociais - Estes achados permitem discussões sobre modelagem e previsão de preços de commodities agrícolas. Os modelos abordados neste estudo bibliométrico podem fornecer referência para os econometristas do campo da previsão de preços de produtos agrícolas, e a pesquisa aponta as tendências sobre a temática, assim pode fornecer direções de pesquisa para econometristas. Originalidade/Relevância - No estudo bibliométrico realizado nas bases de dados Web of Science e SCOPUS, não foi encontrada uma revisão bibliométrica ou sistemática sobre o tema. Os estudos dedicados à revisão sobre previsão de preços de commodities agrícolas, ainda são poucos como as revisões de literatura (Brandt e Bessler, 1983; Wang, et al., 2020).
Reflective Thinking Skills and Attitude towards Problem-solving as Mediated by Mathematical Resilience of the Students
Authors: Simacon Psyche Donna P. , Veloria Elisa V.
Published: November 2022

Aims: This paper explored the mediating effect of mathematical resilience on the relationship between reflective thinking skills and student’s attitude towards problem-solving. Study design: This study utilized a non-experimental quantitative research design utilizing the descriptive-correlational technique.

Place and Duration of Study: The study was conducted at public high schools in the Province of Bukidnon, Philippines in the school year 2021-2022.

Methodology: The respondents of the study were 469 Junior High School students. The respondents were chosen using stratified sampling to simple random sampling. There were three questionnaires utilized to collect the data. The items in each indicator revealed a good interpretation for both validity and reliability of the questionnaires.

Results: The result revealed that the respondents have a high level of both reflective thinking skills and mathematical resilience and has moderate level in their attitude towards problem-solving. The relationship between reflective thinking skills and attitude towards problem-solving; reflective thinking skills and mathematical resilience; and mathematical resilience and attitude towards problem-solving revealed an r-values of .521, .348, and .356 respectively, with a p- value of <.001 which is highly significant at 0.01 level of significance. Furthermore, the result also shows that mathematical resilience partially mediates the relationship between reflective thinking skills and attitude towards problem-solving.

Conclusion: The attitude towards problem-solving is directly impacted by one’s capacity for reflective thinking. On the other hand, the ability to engage in reflective thinking has an effect, albeit an indirect one, on students' mathematical resilience, which in turn influences the students' attitude toward problem solving.
Appropriate Description of Probability Distribution of Prostrate Specific Antigen (PSA): An Aid to Early Detection of Prostrate Cancer
Authors: Nwaigwe Chrysogonus Chinagorom , Ogbonna Chukwudi Justin , Oliwe Emmanuel Uchechukwu
Published: November 2022

Prostrate cancer has been observed to be a worrisome ailment among adult males across the globe over some decades. Just like any other ailment, its early detection and treatment gives the patient a better chance of survival. Measuring the Prostrate specific antigen (PSA) of the patients at specified intervals is one of the techniques of detecting the onset of prostrate cancer. This paper attempts to obtain the most appropriate probability distribution of prostrate specific antigens (PSA) that gives the best estimates of the parameters of the distribution. The age specific probabilities of patients with prostrate specific antigen (PSA)>4.0ng/ml were calculated. The results show that the most appropriate distribution among the distributions fitted is the Burr distribution. The probability of observing a PSA greater than 4.0 ng/ml in adult males above the age of 45 years was seen to be moderately high (0.68) with a median PSA of 8.30 ng/ml and an inter quartile range of 16.40. The results also show that PSA of 60.0 ng/ml and above were exceptional cases that require urgent attention. It was observed that men whose ages are between 60 and 80 years have higher chances of having PSA values greater 4.0ng/ml with men between 60 and 75 years having the highest chances. It is therefore suggested that men with PSA higher than 4.0ng/ml between 60 and 80 years of age may not be subjected to needle biopsies but be referred directly for digital rectal examinations.
Molecular Detection of blaTEM, blaCTX-M and blaSHV Genes in Extended Spectrum β-Lactamase (ESBL) Escherichia coli from Clinical Samples
Authors: Chaudhary Mahesh Kumar , Jadhav Indrani , Banjara Megha Raj
Published: November 2022

Introduction: Extended spectrum β-lactamases are the group of β-lactamase enzymes which confer resistance to the oxyimino-cephalosporins and monobactams.

Study Design: Cross-sectional prospective study.

Place and Duration of Study: This study was conducted over a period of 2 years (September 2018 to April 2020) at microbiology laboratory of Nepal Mediciti Hospital.

Methodology: Clinical samples were processed in microbiology laboratory and culture isolates were characterized by standard microbiological techniques following standard procedures. Antibiotic susceptibility testing was performed by modified Kirby-Bauer disc diffusion method as recommended by Clinical and Laboratory Standard Institute. Extended spectrum βlactamases were phenotypically confirmed by combined disc method. ESBL producing genes i.e. blaTEM, blaCTX-M and blaSHV were confirmed by PCR.

Results: Of the 1449 total Escherichia coli isolates, 323/1449(22.29%) isolates were multidrug resistance. Among total MDR E. coli isolates, 215/323(66.56%) isolates were ESBL producers. The maximum number of ESBL E. coli was isolated from urine 194(90.23%), followed by sputum 12(5.58%), swab 5 (2.32%), pus 2 (0.93%) and blood 2 (0.93%). Antibiotic susceptibility pattern of ESBL E. coli producers showed highest sensitivity towards tigecycline (100%) followed by polymyxin B, colistin and meropenem. Out of 215 phenotypically confirmed ESBL E. coli, only 186(86.51%) isolates were found to positive by PCR. The last 29(13.49%) were negative for any of the resistant genes. Among the ESBL genotypes, most common was blaTEM 118(63.4%) followed by blaCTX-M 68(36.6%).

Conclusion: The emergence of ESBL producing E. coli isolates with high antibiotic resistant rates to commonly used antibiotics and increased predominance of major gene types blaTEM is a serious concern to the clinicians as well as microbiologist. This study forwarded a real massage to all the clinicians for the emergence of XDR and PDR resistant bacteria and preservation of antibiotics for their proper use in near future, if past experience with MDR and ESBLs is any indicator.

Aims: This study was focused to find out the ESBL producing Escherichia coli and detection of TEM, SHV and CTXM genes by Polymerase Chain Reaction (PCR).
Personal Financial Planning and the Allocation of Disposable Wealth
Authors: Puelz Amy v. , Puelz Robert
Published: July 2002

In the process ofpersonalfinancial planning individuals are confronted with a time dependent wealth allocation problem. Oftentimes the solution involves selectingjnancial products based on objective criteria, for example, product cost and expected return. While objective criteria are important to the selection process, an individual’s subjective valuation of all criteria, objective and subjective, relevant to the decision plays the crucial role. A goal programming model parameterized by the analytical hierarchy process is presented to determine the allocation of an individual 5 disposable wealth to present and future consumption bundles and investable assets, conditional on the preference ordering of the individual.
Regulation of V‐ATPases by reversible disassembly
Authors: Kane Patricia M
Published: July 2002

V‐ATPases consist of a complex of peripheral subunits containing catalytic sites for ATP hydrolysis, the V1 sector, attached to several membrane subunits containing a proton pore, the V0 sector. ATP‐driven proton transport requires structural and functional coupling of the two sectors, but in vivo, the interaction between the V1 and V0 sectors is dynamic and is regulated by extracellular conditions. Dynamic instability appears to be a general characteristic of V‐ATPases and, in yeast cells, the assembly state of V‐ATPases is governed by glucose availability. The structural and functional implications of reversible disassembly of V‐ATPases are discussed.
Polymyxin B binds to anandamide and inhibits its cytotoxic effect
Authors: Wang Yin , Liu Yan , Sarker Krishna Pada , Nakashima Mihoko , Serizawa Takeshi , Kishida Akio , Akashi Mitsuru , Nakata Masanori , Kitajima Isao , Maruyama Ikuro
Published: July 2002

Anandamide (ANA), an endogenous cannabinoid, can be generated by activated macrophages during endotoxin shock and is thought to be a paracrine contributor to hypotension. We discovered that ANA in saline/ethanol solution and in serum was efficiently adsorbed in a polymyxin B (PMB)‐immobilized beads column and eluted with ethanol. We confirmed the direct binding of PMB to ANA by using surface plasmon resonance. The adsorption of ANA by PMB may abolish the diverse effects of ANA such as hypotension, immunosuppression, and cytotoxicity, and may suggest a new therapeutic strategy for endotoxin shock.
Sialidase Activity in Culture Fluid of Chinese Hamster Ovary Cells during Batch Culture and Its Effect on Recombinant Human Antithrombin III Integrity
Authors: Munzert Eberhard , Müthing Johannes , Büntemeyer Heino , Lehmann Jürgen
Published: July 2002

Sialidase activity in cell‐free supernatant of batch‐cultivated Chinese hamster ovary (CHO) cells producing human recombinant antithrombin III (rhAT III) was monitored during cultivation using 4‐methylumbelliferyl substrate and HPLC for free sialic acid determination. Supernatant sialidase as well as lactate dehydrogenase activity increased significantly during batch growth. The enhanced number of dead cells correlated with increasing sialidase activity which seemed to be principally due to cell lysis, resulting in release of cytosolic sialidase. Loss of terminally α(2→3) bound sialic acids of the oligosaccharides of rhAT III was analyzed in lectin‐based Western blot and enzyme‐linked lectin assays, using Maackia amurensis and Daturastramoniumagglutinins for specific determination of Neu5Acα(2→3)Gal‐ and Galβ(1→4)GlcNAc‐terminated glycoproteins, respectively. Results show a remarkable loss of terminal sialic acids of rhAT III along with decrease in CHO cell viability and concomitant increase of dead cells throughout long‐term batch cultivation. To avoid this degradation effect, process parameters forcing high viability are essential and harvesting of culture at an early time even at suboptimal recombinant protein concentrations is highly recommended to avoid product desialylation.
Luciferase‐Dependent, Cytochrome P‐450‐Catalyzed Dehalogenation in Genetically Engineered Pseudomonas
Authors: Shanker Rishi , Atkins William M.
Published: July 2002

To investigate the possibility of luciferase‐dependent photoreduction of cytochrome P‐450's in vivo, Vibrio harveyiluciferase was coexpressed with the bacterial cytochrome P‐450cam in Pseudomonas putida. Luciferase expression was under the control of the Pm promoter from the meta‐cleavage TOL operon, incorporated into the chromosome by a mini Tn5‐mediated transposition. Cytochrome P‐450cam expression was controlled by the Ptac‐lac promoter on the broad host range vector pMMB206. Both proteins were expressed in Pseudomonasputida strain MTCC 102 (PpW). This strain does not harbor the cam plasmid, which encodes the enzymes responsible for degradation of the terpene camphor. The metabolic activity of the resulting strain (PpW‐lux‐cam) toward model halogenated compounds was studied. In the absence of the natural cytochrome P‐450cam, electron transfer partners putidaredoxin (PR) and putidaredoxin reductase (Fp), and at low oxygen tension, the bacterial cells efficiently dehalogenate model chlorinated hydrocarbons in a light‐independent reaction. Hexachloroethane and pentachloroethane were metabolized to tetrachloroethylene and trichloroethylene, respectively, at rates comparable to that of strain PpG786, which carries the cam plasmid. Reductive dehalogenation required the expression of both luciferase and cytochrome P‐450 in the same cells. These results indicate that alternative electron transfer partners may be exploited for cytochrome P‐450‐dependent bioremediation strategies.
Three‐dimensional solution structure of a disulfide bond isomer of the human insulin‐like growth factor‐I
Authors: Sato A. , Koyama S. , Yamada H. , Suzuki S. , Tamura K. , Kobayashi M. , Niwa M. , Yasuda T.
Published: July 2002

Abstract: The solution structure of a disulfide bond isomer of human insulin‐like growth factor‐I (IGF‐I) was determined using homonuclear NMR methods. A total of 292 interatomic distance constraints, including 12 related to the disulfide bridges, was used in the distance geometry calculations. The determined structures contain two helical rods corresponding to the sequence regions, Ala8–Cys18 and Leu54–Cys61. Comparison with the previously determined structure of native human IGF‐I revealed partial correspondence of the secondary structure (helices I: Ala8–Cys18 and helices III: Leu54–Cys61) and internal packing. Helix II in native human IGF‐I (residues Gly42–Cys48) is disrupted in the isomer. A similar relationship has been described between the structure of native insulin and a homologous disulfide isomer, suggesting that these alternative folds represent general features of insulin‐like sequences. In each case the precision of the distance geometry ensemble is low due in part to resonance broadening and a paucity of NOEs relative to other globular proteins of this size. These observations suggest that tertiary structure of the isomer is not highly ordered. Comparison of the biological activities of native and the disulfide bond isomer of human IGF‐I highlight the importance of Tyr24, Phe25, Phe49–Cys52 and Phe16 in binding to the IGF‐I receptor or specific IGFBPs. The relationship of this proposed receptor‐binding surface of human IGF‐I to those of insulin is discussed.
A novel property caused by frustration between ferroelectricity and antiferroelectricity and its application to liquid crystal displays-frustoelectricity and V-shaped switching
Authors: Matsumoto Takahiro , Fukuda Atsuo , Johno Masahiro , Motoyama Yuki , Yui Tomoyuki , Seomun San-Seong , Yamashita Mamoru
Published: July 2002

We have studied the frustration between ferro- and antiferro-electricity in chiral smectic C like liquid crystalline phases, which is not only fundamentally interesting but also very attractive from an application point of view. It causes temperature induced successive phase transitions as characterized by a devil's staircase and the thresholdless, hysteresis-free, V-shaped switching induced by an applied electric field. The devil's staircase indicates some type of interlayer ordering, while the V-shaped switching suggests considerably diminished tilting correlation. These two are apparently contradictory to each other, but result from the same cause,i.e.the frustration. We have first summarized experimental facts regarding subphases and successive phase transitions observed in many compounds and mixtures, which we believe are related to one another and result from the frustration. We have introduced several different theoretical explanations for these observed facts, and shown that only the axial next nearest neighbor Ising (ANNNI) model can explain almost all of the facts, provided that it is unified with the XY model appropriately. The unified model can make a comprehensive explanation in the most natural way based on the most probable molecular interactions. We have then emphasised that there are several modes regarding the V-shaped switching, because the system becomes so soft with respect to the tilting direction and sense that any additional external or internal force modifies the in-plane local director alignments. For the practically usable ones, we have emphasised the need for some type of randomization in the molecular alignment at the tip of the V and/or the switching process. In particular, the two dimensional (ideally, cylindrically symmetric) azimuthal angle distribution of local in-plane directors around the smectic layer normal is most attractive. Such a randomized state at the tip of the V is thermodynamically unique under a given condition imposed by interfaces. It stays stable even when the smectic layer structure, such as a chevron, changes with temperature. Finally, we have summarized the so-far reported compounds and mixtures for the V-shaped switching and introduced some prototypes of LCDs using them.
Two novel procedures for automatic resolution of
two-way data from coupled chromatography
Authors: Gan Feng , Xu Qing-Song , Liang Yi-Zeng
Published: July 2002

In order to deal with the problem of simultaneous qualitative
and quantitative analysis of the complicated samples in analytical
chemistry, two novel procedures for automatic resolution of two-way data
from coupled chromatography were developed in this work. The first can be
used to determine automatically the number of components involved in a
certain peak cluster. The second method is an iterative resolution
procedure named the stepwise key spectrum selection which has also been
developed to resolve automatically the spectra and chromatographic profiles
of every component in the peak cluster investigated. The results obtained
from simulated and real data show that the proposed methods perform fairly
well.
Engineering of a monomeric and low‐glycosylated form of human butyrylcholinesterase
Authors: Nachon Florian , Nicolet Yvain , Viguié Nathalie , Masson Patrick , Fontecilla‐Camps Juan C. , Lockridge Oksana
Published: July 2002

Human butyrylcholinesterase (BChE; EC 3.1.1.8) is of particular interest because it hydrolyzes or scavenges a wide range of toxic compounds including cocaine, organophosphorus pesticides and nerve agents. The relative contribution of each N‐linked glycan for the solubility, the stability and the secretion of the enzyme was investigated. A recombinant monomeric BChE lacking four out of nine N‐glycosylation sites and the C‐terminal oligomerization domain was stably expressed as a monomer in CHO cells. The purified recombinant BChE showed catalytic properties similar to those of the native enzyme. Tetragonal crystals suitable for X‐ray crystallography studies were obtained; they were improved by recrystallization and found to diffract to 2.0 Å resolution using synchrotron radiation. The crystals belong to the tetragonal space group I422 with unit cell dimensions a = b = 154.7 Å, c = 124.9 Å, giving a Vm of 2.73 Å3 per Da (estimated 60% solvent) for a single molecule of recombinant BChE in the asymmetric unit. The crystal structure of butyrylcholinesterase will help elucidate unsolved issues concerning cholinesterase mechanisms in general.
Plasma concentrations of disodium cromoglycate after various inhalation methods in healthy subjects
Authors: Kato Y. , Muraki K. , Fujitaka M. , Sakura N. , Ueda K.
Published: July 2002

Aims
To compare the plasma concentrations of disodium cromoglycate (DSCG) following various inhalation procedures in healthy volunteers.

Methods
Nine healthy subjects inhaled 2 mg of aerosol, 20 mg of nebuliser solution only, 20 mg of nebuliser solution mixed with isotonic saline, or 20 mg of nebuliser solution mixed with saline and procaterol, a β2‐adenoceptor agonist, on separate occasions 2–3 weeks apart. Plasma concentrations of DSCG were determined by high‐performance liquid chromatography (h.p.l.c.).

Results
The peak plasma concentrations of DSCG were 1.5±0.7 (range 0.4–2.4) ng ml−1 in the aerosol group, 8.8±6.2 (range 5.3–19.9) ng ml−1 in the nebuliser solution only group, 17.2±16.3 (range 5.0–38.6) ng ml−1 in the nebuliser solution plus isotonic saline group, and 24.5±11.9 (range 10.2–44.9) ng ml−1 in the nebuliser solution plus saline and procaterol group. Thus subjects who used the nebuliser had markedly higher plasma concentrations of DSCG than subjects who used the aerosol inhaler.

Conclusions
These findings may have important implications for the evaluation of inhalation treatment with DSCG for bronchial asthma.
Comparing global models of terrestrial net primary productivity (NPP): analysis of differences in light absorption and light‐use efficiency
Authors: Ruimy A. , Kergoat L. , Bondeau A. , Intercomparison ThE. Participants OF. ThE. Potsdam NpP. Model
Published: July 2002

Twelve global net primary productivity (NPP) models were compared: BIOME3, CASA, CARAIB, FBM, GLO‐PEM, HYBRID, KGBM, PLAI, SDBM, SIB2, SILVAN and TURC. These models all use solar radiation as an input, and compute either absorbed solar radiation directly, or the amount of leaves used to absorb solar radiation, represented by the leaf area index (LAI). For all models, we obtained or estimated photosynthetically active radiation absorbed by the canopy (APAR). We then computed the light use efficiency for NPP (LUE) on an annual basis as the ratio of NPP to APAR. We analysed the relative importance for NPP of APAR and LUE. The analyses consider the global values of these factors, their spatial patterns represented by latitudinal variations, and the overall grid cell by grid cell variability. Spatial variability in NPP within a model proved to be determined by APAR, and differences among models by LUE. There was a compensation between APAR and LUE, so that global NPP values fell within the range of ‘generally accepted values’. Overall, APAR was lower for satellite driven models than for the other models. Most computed values of LUE were within the range of published values, except for one model.
Social class and census‐based deprivation scores: which is the best predictor of stillbirth rates?
Authors: Joyce  , Webb  , Peacock
Published: July 2002

This study investigates whether social class or a census‐based deprivation score is a better predictor of stillbirth rates using data for 1993–5 for residents of South Thames (West) Region. Social class is routinely coded for 10% of live births and 100% of stillbirths. A Townsend deprivation score was assigned to each stillbirth and each live birth with a social class code, according to their electoral ward of residence. In unifactorial analyses of stillbirth rate the relationship was stronger with social class (P = 0.008) than with Townsend score (P = 0.11). Both relationships were strengthened by including those births recorded as social class ‘other’[‘other’ vs. social class I odds ratio (OR) = 2.27, P < 0.001; lower vs. upper septile deprivation score OR = 1.45, P = 0.07)]. When social class and Townsend score were analysed together, the ORs for social class remained similar to before, but the Townsend ORs were reduced and non‐significant overall. We conclude that social class, which is based on data on each individual, is a better predictor of stillbirth than Townsend score, which is based on data from the area of residence. We recommend further investigation of the stillbirth risk in the subgroups that make up the ‘other’ social class.
Incidence of Type 1 diabetes mellitus in children aged 0–14 in Japan, 1986–1990, including an analysis for seasonality of onset and month of birth: JDS study
Authors: Kida K. , Mimura G. , Ito T. , Murakami K. , Ashkenazi I. , Laron Z. , Of The Data Committee for Childhood Diabetes , (jds) The Japan Diabetes Society
Published: July 2002

Aims To detect the incidence of childhood Type 1 diabetes mellitus (DM) (0–14 years) in Japan and to find out whether there is a seasonal pattern in the onset of disease and month of birth of children with diabetes.

Methods Ascertained data for the period 1986–1990 could be collected in 35 out of 47 local government areas representing 69.4% of the childhood population (aged 0–14 years) of Japan.

Results A total of 1260 children with Type 1 DM were identified (738 girls, 522 boys). With age there was a progressive increase in incidence from 0.7 to 2.1/105 in boys and from 0.6 to 3.5/105 in girls. With the exception of 1987, when a coxsackie B3 virus epidemic was registered, no seasonal variation in the month of onset was observed, nor was a seasonal pattern of the month of birth registered in this cohort.

Conclusions Compared to European countries, the USA and Israel, the Japanese cohort of children with diabetes presents the following differences: the incidence is much lower, there is a preponderance of girls and there is (with one exception) no seasonal pattern.
Changes in Quality of Life in Epilepsy: How Large Must They Be to Be Real?
Authors: Wiebe Samuel , Eliasziw Michael , Matijevic Suzan
Published: July 2002

Summary:  Purpose: The study goal was to assess the magnitude of change in generic and epilepsy‐specific health‐related quality‐of‐life (HRQOL) instruments needed to exclude chance or error at various levels of certainty in patients with medically refractory epilepsy.

Methods: Forty patients with temporal lobe epilepsy and clearly defined criteria of clinical stability received HRQOL measurements twice, 3 months apart, using the Quality of Life in Epilepsy Inventory‐89 and ‐31 (QOLIE‐89 and QOLIE‐31), Liverpool Impact of Epilepsy, adverse drug events, seizure severity scales, and the Generic Health Utilities Index (HUI‐III). Standard error of measurement and test‐retest reliability were obtained for all scales and for QOLIE‐89 subscales. Using the Reliable Change Index described by Jacobson and Truax, we assessed the magnitude of change required by HRQOL instruments to be 90 and 95% certain that real change has occurred, as opposed to change due to chance or measurement error.

Results: Clinical features, point estimates and distribution of HRQOL measures, and test‐retest reliability (all > 0.70) were similar to those previously reported. Score changes of ±13 points in QOLIE‐89, ±15 in QOLIE‐31, ±6.3 in Liverpool seizure severity–ictal, ±11 in Liverpool adverse drug events, ±0.25 in HUI‐III, and ±9.5 in impact of epilepsy exclude chance or measurement error with 90% certainty. These correspond, respectively, to 13, 15, 17, 18, 25, and 32% of the potential range of change of each instrument.

Conclusions: Threshold values for real change varied considerably among HRQOL tools but were relatively small for QOLIE‐89, QOLIE‐31, Liverpool Seizure Severity, and adverse drug events. In some instruments, even relatively large changes cannot rule out chance or measurement error. The relation between the Reliable Change Index and other measures of change and its distinction from measures of minimum clinically important change are discussed.
Development and Validation of a Risk‐Adjustment Index for Older Patients: The High‐Risk Diagnoses for the Elderly Scale
Authors: Desai Mayur M. , Bogardus Sidney T. , Williams Christianna S. , Vitagliano Gail , Inouye Sharon K.
Published: July 2002

OBJECTIVES:

The purpose of this study was to develop and validate a risk‐adjustment index for 1‐year mortality specific to older people, based on administrative discharge diagnoses.

DESIGN:

Two prospective cohort studies, in tandem. The index developed in the initial cohort was subsequently validated in a separate cohort.

SETTING:

General medicine service of a university teaching hospital.

PARTICIPANTS:

For the development cohort, 524 hospitalized general medical patients aged 70 and older. For the validation cohort, 852 comparable patients.

MEASUREMENTS:

Administrative diagnosis data were used to construct the proposed index and several other widely used indices (Deyo‐adapted Charlson; Acute Physiology, Age, Chronic Health Evaluation III conditions; total number of diagnoses; All Patient Refined Diagnosis Related Groups; and Disease Staging). We used receiver operating characteristic curve analysis and Cox proportional hazards modeling to compare our proposed index with the other indices with respect to predictive accuracy and strength of association with 1‐year mortality.

RESULTS:

The High‐Risk Diagnoses for the Elderly Scale was developed using 10 high‐risk medical diagnoses. Individual condition weights, based on the magnitude of 1‐year mortality risk, ranged from 1 (pneumonia, diabetes mellitus with end‐organ damage) to 6 (lymphoma/leukemia); possible index scores ranged from 0 to 27. Mortality rates for patients categorized into four risk groups based on the index were 9.5%, 31.8%, 46.4%, and 73.6% in the development cohort (C statistic = 0.76), and 9.9%, 24.3%, 33.6%, and 50.8% in the validation subjects (C statistic = 0.68). The new index was a stronger predictor of mortality than several widely used measures.

CONCLUSION:

The High‐Risk Diagnoses for the Elderly Scale, based on readily available administrative data, is a simple, accurate system for prediction of 1‐year mortality in older hospitalized patients that demonstrated generalizability to an independent sample. Future studies are needed to test this index in other settings and populations. J Am Geriatr Soc 50:474–481, 2002.
Investigation of CdTe surfaces by x-ray photoelectron spectroscopy
Authors: Waag A. , Wu Y. S. , Bicknell-Tassius R. N. , Landwehr G.
Published: July 2002

The influence of different CdTe substrate preheats prior to II-VI molecular beam epitaxial growth on surface stoichiometry and oxygen contamination has been studied using x-ray photoelectron spectroscopy. For 15 min preheats with temperatures ranging from 100 to 450 °C, the cadmium to tellurium ratio and the oxide overlayer thickness of (100) CdTe surfaces was determined. A preheat temperature of 200 °C is found to produce optimum stoichiometry. For lower temperatures the CdTe surface is still tellurium rich, as left after etching with bromine-methanol. For higher temperatures, cadmium evaporates faster than tellurium, leaving again a tellurium-rich surface. The oxygen contamination remains nearly unchanged for temperatures below 250 °C. Oxygen starts to blow off for preheat temperatures above 250 °C, with a steep decrease between 250 and 350 °C. For preheat temperatures higher than 350 °C, the oxygen contamination drops below the detection limit.
Mechanical properties of 3C silicon carbide
Authors: Tong Lijun , Mehregany Mehran , Matus Lawrence G.
Published: July 2002

The residual stress and Young’s modulus of 3C silicon carbide (SiC) epitaxial films deposited on silicon substrates were measured by load-deflection measurements using suspended SiC diaphragms fabricated with silicon micromachining techniques. The film’s residual stress was tensile and averaged 274 MPa while the in-plane Young’s modulus averaged 394 GPa. In addition, the bending moment due to the residual stress variation through the thickness of the film was determined by measuring the deflection of free-standing 3C-SiC cantilever beams. The bending moment was in the range of 2.6×10−8–4.2×10−8 N m.
Atomic-scale manipulation in air with the scanning tunneling microscope
Authors: García García Ricardo
Published: July 2002

From the practical point of view, the aim in nanofabrication is to build the smallest possible device operable in air and at room temperature. In this letter, we present a procedure in which a scanning tunneling microscope is used to remove a small number of atoms from a surface at room temperature and pressure. Its potential for high density storage of information is shown by two results: (i) two subnanometer marks, 1.2 nm apart were impressed and (ii) these marks remained unaltered after several observations.
Comparison of electroabsorption in asymmetric triangular and rectangular GaAs/AlxGa1−xAs multiple quantum wells
Authors: Gerber D. S. , Droopad R. , Maracas G. N.
Published: July 2002

We present the first detailed experimental comparison of electroabsorption in equivalent rectangular and asymmetric triangular multiple quantum wells. The absorption spectra are extracted from reflectance and transmittance measurements on molecular beam epitaxy-grown samples. With absorption edges at the same photon energy, the asymmetric triangular quantum well is much wider than its rectangular well counterpart which reduces its absorption coefficient by approximately a factor of nine compared to the rectangular well, in agreement with theoretical estimates. Implications for electroabsorption modulator devices are discussed.
Spectroscopic ellipsometry determination of the properties of the thin underlying strained Si layer and the roughness at SiO2/Si interface
Authors: Nguyen N. V. , Chandler-Horowitz D. , Amirtharaj P. M. , Pellegrino J. G.
Published: July 2002

The existence of both the strain and microroughness at the interface of thermally grown SiO2 films on Si was ascertained unambiguously for the first time by high accuracy spectroscopic ellipsometry. The dielectric function of the interface was determined by a comprehensive data analysis procedure. By carefully examining the dielectric function obtained by our model, the strain was seen to cause a red shift of 0.042 eV of the interband critical point E1 compared with the bulk silicon value. The thickness of the interface region was found to be 2.2 nm of which a significant part is due to the strain.
Nanometer scale patterning of silicon (100) surfaces by an atomic force microscope operating in air
Authors: Tsau Liming , Wang Dawen , Wang K. L.
Published: July 2002

Modification on silicon (100) surfaces was demonstrated by using an atomic force microscope operating in air. Field-enhanced oxidation on silicon surfaces with protection oxide was done locally by biasing a p-type heavily doped silicon tip between −3 and −10 V. Oxide lines of width as small as ∼10 nm were achieved. After a dip in aqueous HF solution, the oxide was etched away; the modification depth, ∼1 nm, was characterized by the same atomic force microscope. Other field induced reactions for patterning are possible.
Nanoscale patterning and oxidation of H-passivated Si(100)-2×1 surfaces with an ultrahigh vacuum scanning tunneling microscope
Authors: Lyding J. W. , Shen T.-C. , Hubacek J. S. , Tucker J. R. , Abeln G. C.
Published: July 2002

Nanoscale patterning of the hydrogen terminated Si(100)-2×1 surface has been achieved with an ultrahigh vacuum scanning tunneling microscope. Patterning occurs when electrons field emitted from the probe locally desorb hydrogen, converting the surface into clean silicon. Linewidths of 1 nm on a 3 nm pitch are achieved by this technique. Local chemistry is also demonstrated by the selective oxidation of the patterned areas. During oxidation, the linewidth is preserved and the surrounding H-passivated regions remain unaffected, indicating the potential use of this technique in multistep lithography processes.
Observation of sulfur-terminated GaAs(001)-(2×6) reconstruction by scanning tunneling microscopy
Authors: Tsukamoto Shiro , Koguchi Nobuyuki
Published: July 2002

Scanning tunneling microscopy (STM) images of smooth, in situ prepared, sulfur-terminated (S-terminated) GaAs(001) surface reconstruction are presented. It is found that (2×6) surface reconstruction is dominant on the S-terminated GaAs(001) surface. This (2×6) reconstruction, of which the cell contains five S-S adatom dimers, is determined by both STM and reflection high-energy electron diffraction. The atomic model, which is consistent with both STM images and electron counting heuristics, is also shown. Moreover, this (2×6) reconstruction is also observed in the case of an (NH4)2Sx-treated surface.
Controlled nitrogen incorporation at the gate oxide surface
Authors: Hattangady S. V. , Niimi H. , Lucovsky G.
Published: July 2002

Nitrogen has been incorporated selectively at the top surface of a conventional thermal gate oxide by nitridation with a remote He–N2 plasma at low temperatures, 23 and 300 °C. On-line Auger electron spectroscopy (AES) has been used to characterize the process. A peak shift in the Si-LVV feature establishes that the nitrogen is bonded to the silicon. The concentration of nitrogen can be varied by a combination of substrate temperature and duration of plasma exposure. Ex situ glancing-angle x-ray photoelectron spectroscopy (XPS) and secondary ion mass spectroscopy (SIMS) confirm that the nitrogen is confined to the immediate vicinity of the surface. Rapid thermal annealing (RTA) of the nitrided oxide at 900 °C in N2 and N2O does not change the N content.
Holographic relaxation spectrometer based on pattern imaging
Authors: Barish Amy , Bradley Michael S. , Johnson Charles S.
Published: July 2002

A holographic relaxation spectrometer is described which produces laser-induced gratings by projecting images of Ronchi rulings onto samples. Major advantages of this design over the conventional cross-beam arrangement are (1) precise control of the phase of the grating and (2) ease of alignment. Spatial filtering prior to reconstruction of the image of the ruling is discussed and illustrated. Also, test results are presented for the photochromic dye methyl red.
High-temperature Stark and radio-frequency–microwave double-resonance microwave spectrometer
Authors: Raw T. T. , Yamamura T. , Gillies C. W.
Published: July 2002

A high-temperature microwave spectrometer has been constructed for the study of hot corrosive gases. The absorption cell consists of a 213-cm X-band copper waveguide which is heated along roughly 130 cm of its length. A thin nickel strip held taut by stainless-steel posts at either end of the waveguide serves as the Stark septum. The sample chamber is coupled to the Stark cell midway along its length by a slip joint formed from two concentric tubes. This design ensures a long effective absorption path length and minimizes sample consumption. The hot cell is used in conjunction with an HP 8400C microwave spectrometer source which has been interfaced to a small computer for data acquisition, storage, and retrieval. The successful operation of the spectrometer has been demonstrated with KOH vapor at 580 °C. The J=2←1 transitions of a number of vibrational states of monomeric KOH have been observed in the region of 32.8 GHz. The observed signal-to-noise ratio of these transitions indicates that the sensitivity compares favorably to spectrometers which have been used to observe higher J transitions in the submillimeter region. Radio-frequency–microwave double resonance techniques have been demonstrated for the first time in a high-temperature Stark cell by observing the J=2←1 ℓ-doublet transitions in the (011O) state of KOH.
Performance of a microscopic imaging ellipsometer
Authors: Beaglehole D.
Published: July 2002

A microscopic imaging ellipsometer has been constructed based on use of a CCD camera and framegrabber board in a PC computer. The performance (sensitivity and speed) are described.
Development of a new microwave plasma torch and its application to diamond synthesis
Authors: Mitsuda Yoshitaka , Yoshida Toyonobu , Akashi Kazuo
Published: July 2002

We have developed a new microwave plasma torch (MW plasma jet), which can generate a pure H2 plasma jet at atmospheric pressure from the end of a center electrode with an input power above 2 kW. The electric field has maximum strength at the end of the electrodes, so the plasma is initially ignited by the electric breakdown. The plasma jet seems to be powered and sustained by the electromagnetic field generated between the electrodes and/or in the chamber. Accordingly, the mechanism to sustain the plasma is considered to be different from that to initially ignite the plasma. In order to confirm the effectiveness of this plasma for CVD processes, the MW plasma jet has been applied to the synthesis of diamond from Ar-H2-CH4 system. Diamond particles or films were successfully synthesized at a higher rate (30 μm/h) on a larger area (25×25 mm2), compared with the usual synthesis methods. The growth rate was in proportion to substrate temperature and/or CH4/H2 ratio up to 1200 °C and/or 10 vol %, respectively. These conditions were a little different from those of other methods reported so far. The results derived confirmed that the MW plasma jet has unique characteristics and that the process developed here was effective for the synthesis of diamond.
Further observations on the operation of a GaAs polarized electron source
Authors: Guo X. Q. , Crowe D. M. , Lubell M. S. , Tang F. C. , Vasilakis A. , Eminyan M. , Slevin J.
Published: July 2002

We report on several important features of GaAs polarized electron source operation. Specifically we point out the beneficial effect on crystal lifetime produced by the constant low-level application of cesium from a dispenser embedded in an extraction anode. Using our experience in low-energy polarized electron-atom scattering as a reference, we also discuss the importance of frequent energy calibrations of GaAs electron beams for high-resolution investigations.
Generation of controllable monodispersed sprays using impulse jet and charging techniques
Authors: Choi Kyung-Jin , Delcorio Brian
Published: July 2002

A technique for producing a tunable monodispersed spray is developed with a combination of impulsed jet and charging techniques. A single orifice impulse-jet droplet generator, of a unique configuration, was used to produce a single stream of uniform droplets over a wide range of diameters. The single stream of droplets is dispersed with an electrostatic charging technique. Control of drop number density was enhanced by a droplet selection technique, in which a number of drops could be removed from the spray.
Polymer film thickness measurement using laser-ultrasound techniques
Authors: Dewhurst R. J. , Noui L. , Shan Q.
Published: July 2002

The thickness of thin polyester film has been measured using ultrasonic Lamb waves which were generated and detected using noncontacting laser techniques. The uncertainty analysis of such a measurement technique has been examined. Systematic errors in both time of flight and distance between laser generation and detection points were estimated and reduced with the assistance of computerized X-scan translation techniques. Thickness measurements with uncertainties of less than 3% have been achieved.
A versatile system for stable generation of uniform droplets
Authors: Switzer Gary L.
Published: July 2002

A system for the production of liquid droplets of uniform size and velocity is described. The precise control of the operating fluid provided by this system allows the generator to function in a droplet-on-demand, burst, or continuous mode of operation. The basic component of the uniform droplet generator is a radially contracting piezoelectric cylinder which forces liquid through a glass-capillary nozzle. Droplet diameters ranging from 5 to 500 μm have been produced by appropriate selection of nozzle aperture and operating mode. Further control of size, velocity, and interdroplet spacing is exercised through the voltage- and fluid-control elements of the system. In addition to its ability to operate in any orientation, the droplet generator is designed with a small cross section and a water cooling feature for operation in coflowing, elevated-temperature environments. The uniform-droplet-generation system has exhibited long-term stability in operations ranging from a single isolated droplet to a stream of calibration-standard droplets separated by center-to-center spacings of less than two diameters. Its capabilities in controlling droplet development and dynamics make it an attractive candidate for use in a wide range of liquid-droplet applications.
Neural networks and their applications
Authors: Bishop Chris M.
Published: July 2002

Neural networks provide a range of powerful new techniques for solving problems in pattern recognition, data analysis, and control. They have several notable features including high processing speeds and the ability to learn the solution to a problem from a set of examples. The majority of practical applications of neural networks currently make use of two basic network models. We describe these models in detail and explain the various techniques used to train them. Next we discuss a number of key issues which must be addressed when applying neural networks to practical problems, and highlight several potential pitfalls. Finally, we survey the various classes of problem which may be addressed using neural networks, and we illustrate them with a variety of successful applications drawn from a range of fields. It is intended that this review should be accessible to readers with no previous knowledge of neural networks, and yet also provide new insights for those already making practical use of these techniques.