bluuebunny/crossref_metadata_2025 huggingface dataset:
Desmontando la maldad: un análisis sobre la resiliencia de Celestina
Authors: Valentín Sánchez Sarah
Published: January 2024

Celestina representa el arquetipo de villana hechicera en la cultura popular hispana. No obstante, su consideración como sujeto con inclinaciones malvadas resulta parcial e incompleta, ya que ignora las circunstancias político-sociales que atraviesan al personaje como mujer madura en la España del siglo XV. En las páginas que siguen se propone la relectura del clásico teniendo en cuenta determinados factores extrínsecos que hacen de Celestina un sujeto complejo y contradictorio. Se cuestiona su supuesta maldad enfatizando el aspecto resiliente en su personalidad y argumentando cómo, durante los años más productivos de su vida, los officios que la estigmatizan son a la vez el motor de su empoderamiento. A partir del marco teórico ofrecido por Silvia Federici se arguye que, por habitar un cuerpo mujer, su natural ambición, conocimiento y experiencia no se traducen en autoridad o estatus en la sociedad patriarcal representada en la Tragicomedia. Es más, su actitud desafiante la imputa como desestabilizadora de la normatividad. Secundariamente, se exploran también las posibles motivaciones que llevan a Fernando de Rojas a representar a la anti-heroína con ambivalencia, concluyendo con la hipótesis de que el autor proyecta en el personaje ciertas ansiedades que le acusan como judío-converso.
La serialidad celestinesca (1990-2023): el caso de La mujer de la escalera de Pedro González Moreno
Authors: Francois Jeromine
Published: January 2024

Durante los Siglos de Oro, la relación hipertextual que existe entre las imitaciones y continuaciones de La Celestina y su modelo se puede describir en términos architextuales. En cambio, en la época contemporánea se ha desarrollado un imaginario celestinesco aún más complejo por ser transmediático. En este trabajo se analizarán las modalidades propiamente novelescas de las reescrituras celestinescas contemporáneas (1990-2023) a la luz del concepto de serialidad: cada texto de tema celestinesco producido y leído en la actualidad moviliza lógicas de personajes, así como dispositivos paratextuales, intertextuales y metaficcionales que crean un verdadero pacto de lectura celestinesco, basado en una enciclopedia particular del lector. Después de un examen panorámico de las prácticas de serialidad evidenciadas en las reescrituras de la Tragicomedia de Calisto y Melibea publicadas desde 1990, este estudio examinará cómo se articulan dichas prácticas en la novela La mujer de la escalera (2018), de Pedro González Moreno.
Perspectiva narrativa de la figura del narrador en el Evangelio de Mateo
Authors: Olivares Carlos
Published: January 2024

Empleando las presuposiciones metodológicas y las herramientas operacionales del criticismo narrativo, este artículo explora la figura literaria del narrador en el Evangelio de Mateo. El trabajo examina, desde la perspectiva del lector implícito, las características del narrador, enfocándose en su narración omnisciente e intrusiva. Este artículo analiza, además, los datos informativos que el narrador emplea al contar la historia, prestando atención también a las lagunas de conocimiento y narrativa que el narrador deja entrever en ciertas escenas. El trabajo concluye indagando la relación del narrador y el destinario del texto, especulando cuanto es posible literariamente saber acerca de él/ella.
poder do silêncio nos Cantos do servo e na escravidão do Brasil
Authors: Silva Rosemary Francisca Neves , Da Silva Valmor
Published: January 2024

O artigo desenvolve, em duas partes, o silenciamento de pessoas escravizadas no exílio babilônico e no Brasil colonial. Mostra como esse silêncio se torna poderoso, em forma de resistência, de luta por direito e justiça e por mudança da realidade. Na primeira parte, são selecionados quatro versos relativos ao silenciamento da palavra, um em cada canto do servo sofredor (Is 42,2; 49,4; 50,4; 52,15). Na segunda parte, são analisados aspectos semelhantes, com relação à escravidão africana no Brasil, tais como cantos de esperança, manifestações religiosas e tradições culturais. Com essa exposição, objetiva-se demonstrar como o silenciamento das pessoas oprimidas pela escravidão pode inverter-se como força transformadora, através da fé em divindades libertadoras. O método utilizado é bibliográfico, priorizando literatura brasileira. Espera-se, como resultado, reforçar teses e ações em vista da superação de situações de exílio e escravidão.
Machine learning for in silico protein research
Authors: Zhang Jia-Hui ,   School of Life Sciences, University of Science and Technology of China, Hefei 230027, China
Published: January 2024

In silico protein calculation has been an important research subject for a long time, while its recent combination with machine learning promotes the development greatly in related areas. This review focuses on four major fields of the in silico protein research that combines with machine learning, which are molecular dynamics, structure prediction, property prediction and molecule design. Molecular dynamics depend on the parameters of force field, which is necessary for obtaining accurate results. Machine learning can help researchers to obtain more accurate force field parameters. In molecular dynamics simulation, machine learning can also help to perform the free energy calculation in relatively low cost. Structure prediction is generally used to predict the structure given a protein sequence. Structure prediction is of high complexity and data volume, which is exactly what machine learning is good at. By the help of machine learning, scientists have gained great achievements in three-dimensional structure prediction of proteins. On the other hand, the predicting of protein properties based on its known information is also important to study protein. More challenging, however, is molecule design. Though marching learning has made breakthroughs in drug-like small molecule design and protein design in recent years, there is still plenty of room for exploration. This review focuses on summarizing the above four fields andlooks forward to the application of marching learning to the in silico protein research.
Children Anxiety and Pain while Performing Interim Therapeutic Restorations with Hand Instruments compared to Rotary Instruments: A Randomised Clinical Trial
Authors: Felemban Osama M , Bannan Abraar M , Alqadi Rahaf M , Bamashmous Nada O
Published: January 2024

Introduction: Children with dental anxiety may avoid visiting the dentist until a more serious and painful condition develops. Dentists could use less stressful techniques, like Interim Therapeutic Restorations (ITR), to treat dental cavities in difficult or young patients. ITR performed with hand tools may be preferred due to the absence of handpiece vibration, sound, or smell. Aim: To assess the anxiety and pain levels experienced by children during ITR procedures performed with hand instruments compared to rotary instruments. Materials and Methods: The present randomised clinical trial was conducted in the Department of Pediatric Dentistry at King Abdulaziz University Dental Hospital in Jeddah, Saudi Arabia. The inclusion criteria consisted of children aged 3-12 years visiting the dental clinic for the first time and having a carious primary anterior (incisor or canine) tooth. Patients were recruited from the paediatric screening clinic and randomly assigned to either the “Hand instrument group” or the “Rotary instrument group.” Caries excavation was performed using a hand instrument in the former group, while a low-speed handpiece was used in the latter group. Anxiety levels were assessed using Venham’s anxiety rating scale before and after the procedure. Heart rate was measured using pulse oximetry every two minutes. Pain levels were evaluated using the Wong-Baker Faces Pain Rating Scale after completing the procedure. Results: The study included 60 patients, with a mean age of 5.87±2.09 years. The anxiety score after the procedure was significantly lower in the hand instrument group compared to the rotary instrument group (p=0.007). Although the heart rate was lower in the hand instrument group compared to the rotary instrument group, the difference was not statistically significant. The subjects in the hand instrument group reported lower pain levels compared to those in the rotary instrument group (p=0.029). Conclusion: Performing ITR using hand instruments resulted in reduced anxiety and pain levels among young children compared to ITR performed using rotary handpieces.
Паразит паразиту рознь: о различии в стратегии иммунного ответа растения при поражении биотрофом и некротрофом, "Природа"
Authors: Сколотнева Е.С.
Published: January 2024

В естественных условиях растение-хозяин сталкивается не с одним представителем патогенной флоры и фауны, а со смешанным заражением. Почвенное сообщество патогенов представлено преимущественно некротрофами: несовершенными грибами, несептированным мицелием низших грибов, гнилостными бактериями. Наоборот, наземные органы растений чаще всего служат мишенями для специализированных патогенных организмов, распространяющихся в виде спор или в случае вирусной инфекции с помощью насекомых. Отличия в составе атакующих патогенов наблюдаются даже на индивидуальном уровне по мере развития растения. При разработке схем иммунизации важно учитывать положительное и отрицательное взаимное влияние разных паразитов при смешанном заражении на уровне интерференции сигнальных путей иммунного ответа.
Лауреаты Нобелевской премии по химии 2023 года — Алексей Екимов, Луис Брюс и Мунги Бавенди, "Природа"
Authors: Родина А.В.
Published: January 2024

В 2023 г. Нобелевская премия в области химии присуждена Алексею Екимову, Луису Брюсу и Мунги Бавенди за работы 80-х — начала 90-х годов прошлого века, ставшие фундаментом физики и технологии нульмерных структур — квантовых точек. Квантовыми точками называют кристаллы полупроводников нанометрового размера (нанокристаллы), свойства которых определяются эффектом размерного квантования. В настоящее время квантовые точки широко применяются в целом ряде областей: в оптоэлектронике, фотовольтаике, биологии и медицине, а их синтез продолжает совершенствоваться.
Жизнь на Венере, "Земля и Вселенная"
Authors: Говорова А.Ф.
Published: January 2024

Венера – одна из самых загадочных и удивительных планет земной группы. За все время ее изучения с помощью наземных наблюдений и с помощью космических миссий (орбитальных станций и посадочных аппаратов) накоплено большое количество данных, и все равно, тайн у Венеры остается очень много.
По стопам Чижевского: влияние солнечной активности на агрессивность коммуникации в Интернете, "Земля и Вселенная"
Authors: ОЖЕРЕДОВ В.А.
Published: January 2024

В статье рассматриваются подтверждения гипотезы о том, что настроения генерируемого текстового контента, по-видимому, можно рассматривать в качестве параметра, откликающегося на влияние космической погоды. В качестве показателя настроения рассматривается отклик нейросети, обученной на полутора миллионах сообщений с крупнейшего русскоязычного научного форума. Продемонстрирована связь появления текстовых сообщений с высоким уровнем эмоциональной окраски и возникновения рентгеновских вспышек на Солнце.
Market Orientation, Entrepreneurship and SME Performance: The Role of Product Innovation
Authors: Razak Abdul , Ramli Anwar , Azis Muhammad , Sarnawiah
Published: January 2024

Aims: This study aims to analyze market orientation, entrepreneurial orientation, and their impact on SME performance with product innovation as an intervening variable.

Study Design:  Quantitative descriptive.

Place and Duration of Study: South Celebes, between January 2023 and October 2023.

Methodology: The population in this study were SMEs managing crabmeat in South Sulawesi. The research method used is a quantitative approach using a questionnaire as a data collection instrument, which was distributed to 132 samples selected from 395 populations using purposive sampling technique. The collected data were analyzed using regression analysis to test the relationship between the variables studied with the Smart PLS 3.2.9 application.

Results: The results showed that Market Orientation has a positive and significant effect on Product Innovation, Entrepreneurial Orientation has a positive and significant effect on Product Innovation, Product Innovation has a positive and significant effect on SME Performance, Market Orientation has a negative and insignificant effect on SME Performance, and Entrepreneurial Orientation has a positive and significant effect on SME Performance. In addition, Market Orientation has a positive and significant effect on SME Performance through Product Innovation, Entrepreneurial Orientation has a positive and significant effect on SME Performance through Product Innovation.

Conclusion: through product innovation efforts, SMEs can optimize the benefits of entrepreneurial orientation in achieving better performance.
Use of Fish Somatic Indices to Assess Pollutant Exposure and Effects: A Case of Two Urban Rivers and a Wastewater Sedimentation Pond in Lake Victoria Basin
Authors: Omondi Cornel A. , Omondi Reuben , Onyango Daniel W. , Obegi Faith O. , Gichana Zipporah
Published: January 2024

Aquatic ecosystem health assessment is critical for early detection of disturbances and water habitat degradation. This study assessed the ecological status of two urban rivers as well a wastewater sedimentation pond in Kisumu City, Kenya using physico-chemical water quality parameters and the African catfish, Clarias gariepinus somatic indices. Site association of somatic indices was derived from Principal Component Analysis (PCA) whereas the relationship between water quality parameters was examined by Redundancy Ordination Analysis (RDA). PCA results revealed an increase in Gill Somatic Index (GSI) in the wastewater sedimentation ponds while Fulton’s Condition Factor (CF) increased in the midstream of Auji river and Kisat river mouth. Similarly, RDA showed that dissolved oxygen, temperature, total phosphorus, alkalinity and total nitrogen influenced the condition indices upstream of Kisat river and up-stream and midstream of Auji river. However more impact on somatic indices were recorded in the wastewater sedimentation pond. Although specific pollutants other than the physico-chemical parameters were not identified, application of somatic indices in the African catfish demonstrated that the two rivers as well as the wastewater sedimentation pond were contaminated by pollutants that can compromise the ecological health of the aquatic systems. The results of this study emphasized the negative impacts of anthropogenic activities on the environment.
Oxidative Changes among Women Suffering From Urinary Tract Infection in Enugu Metropolis, Nigeria
Authors: Uzoukwu Christian Ihechukwu , Chukwu Johnpaul , Umezurike Kingsley Chimuanya , Ochiabuto Mary-Theodora Barbara , Chukwuemeka Chidera Godson , Nwoye Blessing Uzoma , Ugomore Edmund Osi , Chukwuma George Okechukwu
Published: January 2024

Background: The action of bacterial infection in the urinary tract can trigger the release of free radicals which could progress and overwhelm endogenous antioxidants, hence oxidative changes occur. This work aimed to estimate the level of oxidized low density lipoprotein (Ox-LDL) and superoxide dismutase (SOD), among women suffering from urinary tract infection in Enugu metropolis.
Materials and Methods: Ethical approval was obtained from the Health Research and Ethics committee (HREC) of the University of Nigeria Teaching Hospital (UNTH), Ituku–Ozalla, Enugu State. Informed consent was obtained from all recruited subjects. About forty (40) women diagnosed of UTIs at the UNTH were recruited for the study and twenty (20) women free of UTIs and who are not registered with UNTH were used as a control for this study. Blood specimens were collected and analysed using the ELISA technique to check for Ox-LDL and SOD levels.
Results: The mean value of the antioxidant enzyme, SOD, was lower than that of the control which suggests a possibility of oxidative stress. However, Ox-LDL mean value was lower than that of the control population showing absence of lipid peroxidation in all sampled population, which may have been pronounced if the subjects had complicated UTI like pyelonephritis.
Conclusion: This study showed a drop in the levels of an antioxidant enzyme among UTI patients placing the patients at risk of oxidative stress. Ox-LDL should be higher in test than in control population indicating lipid peroxidation. However, in this study, the Ox-LDL showed no increase in values. Oxidative stress should be looked out for and treated by physicians when treating UTIs.
Development of a Scheffe’s Model to Predict the Duration of Project Tasks
Authors: Oba K. M.
Published: January 2024

This study was aimed at applying Scheffe’s approach to determine task durations with a three-component design, to a second degree. The PERT approach was adopted to estimate the durations of three tasks for a small construction project. The study further applied Scheffe’s simplex theorem to develop a linear regression model to predict the task durations using the durations from the PERT approach. The model-predicted results were found to be very close to those estimated by the PERT approach. The model was tested with a two-tailed student t-test and was found adequate and fit with an R2 value of 0.9986. This proved that Scheffe’s approach can also be used to estimate or predict the durations of project tasks for projects with up to 3 tasks.
Novel Macrocyclic EuII Complexes: Fast Water Exchange Related to an Extreme MOwater Distance
Authors: Burai László , Tóth Éva , Moreau Gilles , Sour Angélique , Scopelliti Rosario , Merbach André E.
Published: March 2003

EuII complexes are potential candidates for pO2‐responsive contrast agents in magnetic resonance imaging. In this regard, we have characterized two novel macrocyclic EuII chelates, [EuII(DOTA)(H2O)]2− and [EuII(TETA)]2− (H4DOTA=1,4,7,10‐tetraazacyclododecane‐1,4,7,10‐tetraacetic acid, H4TETA=1,4,8,11‐tetraazacyclotetradecane‐1,4,8,11‐tetraacetic acid) in terms of redox and thermodynamic complex stability, proton relaxivity, water exchange, rotation and electron spin relaxation. Additionally, solid‐state structures were determined for the SrII analogues. They revealed no inner‐sphere water in the TETA and one inner‐sphere water molecule in the DOTA complex. This hydration pattern is retained in solution, as the 17O chemical shifts and 1H relaxation rates proved for the corresponding EuII compounds. The thermodynamic complex stability, determined from the formal redox potential and by pH potentiometry, of [EuII(DOTA)(H2O)]2− (lg KEu(II)=16.75) is the highest among all known EuII complexes, whereas the redox stabilities of both [EuII(DOTA)(H2O)]2− and [EuII(TETA)]2− are inferior to that of 18‐membered macrocyclic EuII chelates. Variable‐temperature 17O NMR, NMRD and EPR studies yielded the rates of water exchange, rotation and electron spin relaxation. Water exchange on [EuII(DOTA)(H2O)]2− is remarkably fast (k$\rm{_{ex}^{298}}$=2.5×109 s−1). The near zero activation volume (ΔV≠=+0.1±1.0 cm3 mol−1), determined by variable‐pressure 17O NMR spectroscopy, points to an interchange mechanism. The fast water exchange can be related to the low charge density on EuII, to an unexpectedly long MOwater distance (2.85 Å) and to the consequent interchange mechanism. Electron spin relaxation is considerably slower on [EuII(DOTA)(H2O)]2− than on the linear [EuII(DTPA)(H2O)]3− (H5DTPA=diethylenetriaminepentaacetic acid), and this difference is responsible for its 25 % higher proton relaxivity (r1=4.32 mM−1 s−1 for [EuII(DOTA)(H2O)]2− versus 3.49 mM−1 s−1 for [EuII(DTPA)(H2O)]3−; 20 MHz, 298 K).
Allylic Oxidation and First Transformations of a Key Intermediate in the Total Synthesis of Agarofuran Sesquiterpenes
Authors: Boyer François‐Didier , Descoins Charles Laurent , Thanh Giang Vo , Descoins Charles , Prangé Thierry , Ducrot Paul‐Henri
Published: March 2003

This paper describes the synthesis of polyhydroxylated decalinic systems through oxidative furan ring opening of 3‐(2’‐furyl)‐2‐methoxycarbonylcyclohexadione‐4‐monoethylene ketal 12 using dimethyl dioxirane (DMDO). The functionalisation of the decalinic product 5, aimed at the synthesis of antifeedant agarofuran sesquiterpenes according to our previously reported strategy, is demonstrated to occur with good stereochemical control of the introduced oxygenated functions, using as a key step an original allylic oxidation by DMDO. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Copper‐Catalysed Addition of Organometallic Reagents to Vinyl Diepoxides − A Novel Route to Oxa‐Bridged Systems and to Substituted Allylic Alcohols
Authors: Bertozzi Fabio , Crotti Paolo , Del Moro Federica , Di Bussolo Valeria , Macchia Franco , Pineschi Mauro
Published: March 2003

The copper‐catalysed addition of organometallic reagents (Grignard and dialkylzinc) to new vinyl diepoxides was examined. Cyclic vinyl diepoxides undergo clean SN2′ reactions to afford oxa‐bridged systems of various sizes after a domino intramolecular O‐alkylation reaction. Acyclic vinyl diepoxides are alkylated in good yields and with good regioselectivities, and a new catalytic enantioselective desymmetrization reaction to afford an enantioenriched allylic epoxy alcohol by the use of catalytic amounts of a copper phosphoramidite complex was demonstrated. Remarkable differences in terms of reactivity and selectivity are found when different organocopper reagents, generated in situ, are employed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
A QoS management framework for distributed multimedia systems
Authors: Hong Daniel Won‐Kyu , Hong Choong Seon
Published: March 2003

This paper proposes a high‐performance connection management architecture to design a common QoS framework applied
to an ATM network based on the Open Distributed Processing (ODP) concept. We design the QoS framework in accordance
from the RM‐ODP information and computational viewpoints. Copyright © 2003 John Wiley & Sons, Ltd.
Methamphetamine exposure during the preweanling period causes prolonged changes in dorsal striatal protein kinase A activity, dopamine D2‐like binding sites, and dopamine content
Authors: Crawford Cynthia A. , Williams Michael T. , Newman Eva R. , McDougall Sanders A. , Vorhees Charles V.
Published: March 2003

Exposure to methamphetamine (METH) during the preweanling period produces few, if any, neurotoxic effects (using criteria established in adult rats), yet it has substantial long‐term effects on a variety of behavioral measures (e.g., locomotor activity, acoustic startle response, and spatial learning). The purpose of the present study was to examine the long‐term changes in dopaminergic functioning brought about by early METH exposure. Rats were injected with METH (10 mg/kg) or saline four times daily on postnatal days (PD) 11–20 and housed undisturbed until PD 90, at which time they were killed and their dorsal striata (i.e., caudate–putamen) were removed and frozen for assay. The ability of early METH exposure to alter protein kinase A (PKA) activity and dopamine (DA) D2‐like binding sites, as well as DA and DOPAC content, were assessed. Results showed that METH exposure on PD 11–20 caused long‐term reductions in all of the dopaminergic markers assayed. METH‐induced reductions in DA content and D2‐like receptors were observed. Some sex differences were apparent, as the METH‐induced decreases in PKA activity and DOPAC content were more evident in male rats. In conclusion, preweanling METH exposure caused changes in DA markers that were still detectable at PD 90; however the magnitude of many of these effects (e.g., the reductions in DA and DOPAC levels) was substantially less than typically reported for rats treated with METH in adulthood. The ability of METH to cause long‐term reductions in PKA activity may partially account for some of behavioral deficits exhibited by rats exposed to METH prior to weaning. Synapse 48:131–137, 2003. © 2003 Wiley‐Liss, Inc.
Genome-wide expression screens indicate a global role for protein kinase CK2 in chromatin remodeling
Authors: Barz Thomas , Ackermann Karin , Dubois Gaelle , Eils Roland , Pyerin Walter
Published: March 2003

Protein kinase CK2, a vital, pleiotropic and highly conserved serine/threonine phosphotransferase is involved in transcription-directed signaling, gene control and cell cycle regulation and is suspected to play a role in global processes. Searching for these global roles, we analyzed the involvement of CK2 in gene expression at cell cycle entry by using genome-wide screens. Comparing expression profiles of Saccharomyces cerevisiaewild-type strains with strains with regulatory or catalytic subunits of CK2 deleted, we found significant alterations in the expression of genes at all cell cycle phases and often in a subunit- and isoform-specific manner. Roughly a quarter of the genes known to be regulated by the cell cycle are affected. Functionally, the genes are involved with cell cycle entry, progression and exit, including spindle pole body formation and dynamics. Strikingly, most CK2-affected genes exhibit no common transcriptional control features, and a considerable proportion of temporarily altered genes encodes proteins involved in chromatin remodeling and modification, including chromatin assembly,(anti-)silencing and histone (de-)acetylation. In addition, various metabolic pathway and nutritional supply genes are affected. Our data are compatible with the idea that CK2 acts at different levels of cellular organization and that CK2 has a global role in transcription-related chromatin remodeling.
Direct correlation of collagen matrix deformation with focal adhesion dynamics in living corneal fibroblasts
Authors: Petroll W. Matthew , Ma Lisha , Jester James V.
Published: March 2003

The purpose of this study was to develop and apply a new model for investigating how the organization and movement of cell-matrix adhesion sites correlate with force generation by corneal fibroblasts on a fibrillar collagen extracellular matrix. Primary cultures of rabbit corneal fibroblasts were transfected using a vector encoding GFP-zyxin to allow visualization of adhesion sites. Cells were plated at low density on top of 100 μm thick fibrillar collagen lattices embedded with 2 μm diameter red fluorescent beads. Time-lapse imaging was performed at one minute intervals for up to 3 hours. At each time interval, GFP-zyxin, bead and DIC images were acquired in rapid succession using filter wheels. Cells were treated with cytochalasin D and/or Triton X-100 at the end of each experiment. The movements of adhesions and nearby matrix landmarks were measured and correlated from the time-lapse digital images, and the size, intensity and orientation of the adhesions were quantified.

GFP-zyxin was detected in adhesions of transfected corneal fibroblasts as confirmed using vinculin counterstaining. Time-lapse imaging revealed extensions and retractions of cell processes and displacements of the fiduciary beads that were similar to control cells. Extending processes exhibited the most complex behavior, with new adhesions continuously forming at the leading edge while existing adhesions moved backward in a retrograde fashion. This process generated tractional forces as indicated by pulling in of the extracellular matrix in front of the cell. Interestingly, during extension, adhesions along the ventral surface of the cell body generally moved toward those at the tip, resulting in contractile-like shortening and matrix compression at the base of lamellipodia. Overall, a high correlation was found between both the magnitude (R=0.87, P<0.001) and direction (R=0.98, P<0.001) of the adhesions and nearby matrix displacements. Cytochalasin D induced rapid and reversible disassembly of adhesions, cell elongation and matrix relaxation, including decompression at the base of the lamellipodia. This new experimental model allows direct,dynamic assessment of cell-matrix interactions on a fibrillar collagen matrix. Our results are consistent with the previously described `frontal towing'model of cell motility and demonstrate for the first time that this mechanism is employed by cells interacting with a fibrillar extracellular matrix.
Thermoreversible Self-Organized Gels of a Liquid Crystal Formed by Aggregation of trans-1,2-Bis(acylamino)cyclohexane Containing a Mesogenic Moiety
Authors: Kato Takashi , Kondo Gohta , Hanabusa Kenji
Published: March 2003

A novel class of anisotropic gels has been obtained by the formation of a self-associated molecular network in a liquid crystal. The gels exhibit thermoreversible two gel states derived from liquid-crystalline and isotropic states of the mesogenic molecule.
Development and evaluation of an advanced training technology course within a union‐based industrial emergency response training program
Authors: Fernandez Jennifer A. , Vazquez Luis , Daltuva Judith A. , Robins Thomas G. , Williams Melina
Published: March 2003

Background

The Health and Safety Department of the United Automobile Workers recently introduced the use of Advanced Training Technologies (ATTs) into a previously successful Industrial Emergency Response (IER) program. The new curriculum attempted to incorporate web‐based technology, while preserving the historical emphasis on the use of peer trainers and the Small Group Activity Method (SGAM) to promote team problem solving and worker empowerment.

Methods

The University of Michigan evaluated the program by administering a survey combining open‐ and closed‐ended questions to trainees.

Results

Of the 46 respondents, most rated the program very highly, found that the use of internet technology allowed faster access to current information, reported peer trainers as one of program aspects they liked best, and did not find working in groups of three per computer difficult.

Conclusions

It is possible to enhance a workplace health and safety training program through the introduction of ATT without compromising participant‐centered, group learning program philosophies. Am. J. Ind. Med. 43:429–435, 2003. © 2003 Wiley‐Liss, Inc.
Crystallographic report: Crystal structure of a one‐dimensional zinc(II) coordination polymer containing 4,4′‐biphenyldicarboxylate hemihydrate
Authors: Yuan Wei , Long La‐Sheng
Published: March 2003

A one‐dimensional zinc(II) coordination polymer has been constructed from zinc(II), 4,4′‐biphenyldicarboxylate and pyridine in which each zinc(II) atom is coordinated by two pyridine ligands and two monodentate 4,4′‐biphenyldicarboxylate ligands that define a distorted tetrahedral geometry. Copyright © 2003 John Wiley & Sons, Ltd.
Synthesis of all Four Stereoisomers of Leucomalure, Components of the Female Sex Pheromone of the Satin Moth, Leucoma salicis
Authors: Muto Shin‐etsu , Mori Kenji
Published: March 2003

Lipase PS‐C(Amano)‐catalyzed asymmetric acetylation of (±)‐4‐(tert‐butyldiphenylsilyloxy)‐cis‐2,3‐epoxy‐1‐butanol afforded the (2R,3S)‐epoxy alcohol and the (2S,3R)‐epoxyacetate, which were converted into all of the four stereoisomers of leucomalure [(3Z)‐cis‐6,7‐cis‐9,10‐diepoxy‐3‐henicosene], the female sex pheromone of the Satin moth, Leucoma salicis. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Facile distinction of neutral and acidic tetraether lipids in archaea membrane by halogen atom adduct ions in electrospray ionization mass spectrometry
Authors: Murae Tatsushi , Takamatsu Yuichiro , Muraoka Ryohei , Endoh Satoshi , Yamauchi Noriaki
Published: March 2003

Calditocaldarchaeol (neutral tetraether lipid) from Sulfolobus acidocaldarius (acidothermophilic archaea) and intact total lipid from the thermoacidophilic archaea Sulfolobus sp. was examined by electrospray ionization time‐of‐flight mass spectrometry in the negative‐ion mode using high resolution. When the sample was injected as a solution in a 3 : 1 mixture of methanol (MeOH) and chloroform (CHCl3) using an infusion system, the total ether lipid afforded molecular‐related ions as [M − H]− for acidic polar lipids containing a phosphoric or sulfuric group, and as [M + Cl]− ion for neutral glycolipids. The attachment of chloride was confirmed by the observation of [M + Br]− ion, instead of [M + Cl]− ion, when a 3 : 1 mixture of MeOH and CHBr3 was used in place of MeOH–CHCl3 as the solvent. The composition of tetraether neutral glycolipids that are different from each other only in the number of five‐membered rings in the isoprenoid chain was determined on the basis of the isotope‐resolved mass spectrum of [M + Cl]− ions. As for acidic tetraether lipids, molecular‐related ions [M − H]−) were not observed when the 3 : 1 MeOH–CHBr3 mixture was used as the solvent. These results together afforded a facile method of distinguishing neutral from acidic tetraether lipids in intact total lipids of acidothermophilic archaea. This method was applied to determine the difference of the number of five‐membered rings in isoprenyl chains of neutral tetraether glycolipids yielded by the Sulfolobus sp. grown at different temperatures. Discrimination of neutral tetraether glycolipids from acidic tetraether lipids in the total lipids obtained from Thermoplasma sp. was also achieved by this method. Copyright © 2002 John Wiley & Sons, Ltd.
L‐phenylalanine selectively depresses currents at glutamatergic excitatory synapses
Authors: Glushakov A.V. , Dennis D.M. , Sumners C. , Seubert C.N. , Martynyuk A.E.
Published: March 2003

To explore the hypothesis that L‐phenylalanine (L‐Phe) depresses glutamatergic synaptic transmission and thus contributes to brain dysfunction in phenylketonuria (PKU), the effects of L‐Phe on spontaneous and miniature excitatory postsynaptic currents (s/mEPSCs) in rat and mouse hippocampal and cerebrocortical cultured neurons were studied using the patch‐clamp technique. L‐Phe depressed the amplitude and frequency of both N‐methyl‐D‐aspartate (NMDA) and non‐NMDA components of glutamate receptor (GluR) s/mEPSCs. The IC50 of L‐Phe to inhibit non‐NMDAR mEPSC frequency was 0.98 ± 0.13 mM, a brain concentration seen in classical PKU. In contrast, D‐Phe had a significantly smaller effect, whereas L‐leucine, an amino acid that competes with L‐Phe for brain transporter, had no effect on mEPSCs. Unlike GluR s/mEPSCs, GABA receptor mIPSCs were not attenuated by L‐Phe. A high extracellular concentration of glycine prevented the attenuation by L‐Phe of NMDAR current, activated by exogenous agonist, and of NMDAR s/mEPSC amplitude, but not of NMDAR s/mEPSC frequency. On the other hand, L‐Phe significantly depressed non‐NMDAR current activated by low but not high concentrations of exogenous agonists. Glycine‐independent attenuation of NMDAR s/mEPSC frequency suggests decreased presynaptic glutamate release caused by L‐Phe, whereas decreased amplitudes of NMDAR and non‐NMDAR s/mEPSCs are consistent with competition of L‐Phe for the glycine‐ and glutamate‐binding sites of NMDARs and non‐NMDARs, respectively. The finding that GluR activity is significantly depressed at conditions characteristic of classical PKU indicates a potentially important contribution of impaired GluR function to PKU‐related mental retardation and provides important insights into the potential physiological consequences of impaired GluR function. © 2003 Wiley‐Liss, Inc.
Mixed FEM and BEM coupling for the three‐dimensional magnetostatic problem
Authors: Daveau C. , Menad M.
Published: March 2003

We present two new mixed finite element methods coupled with a boundary method for the three dimensional magnetostatic problem. Such formulations are obtained by coupling a finite element method inside a bounded domain with a boundary integral method involving either the Calderon equations or the inverse of Dirichlet Neumann operator to treat the exterior domain. First, we present the formulations and then prove that our mixed formulations are well posed and that they lead to a convergent Galerkin method. Finally, we give numerical results for a sphere immersed in a homogeneous (source) field in the two formulations. © 2003 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 19: 443–462, 2003
Error estimate and regularity for the compressible Navier‐Stokes equations by Newton's method
Authors: Kim Sang Dong , Lee Yong Hun
Published: March 2003

The finite element discretization error estimate and H1 regularity are shown for the solution generated by Newton's method to the stationary compressible Navier‐Stokes equations by interpreting Newton's method as an equivalent iterative method. © 2003 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 19: 511–524, 2003
Qi-training Enhances Respiratory Burst Function and Adhesive Capacity of Neutrophils in Young Adults: A Preliminary Study
Authors: Lee Myeong Soo , Jeong Seong Min , Kim Yong-Kyu , Park Ki-Won , Lee Myung Suk , Ryu Hoon , Moon Sun-Rock
Published: March 2003

The main objective of this study is to examine the effect of Qi-training on the immune system, especially neutrophil bactericidal function. Nine healthy male subjects were studied for the effects of one bout of ChunDoSunBup (CDSB) Qi-training on superoxide (O2-) production and adhesion capacity of neutrophils at times immediately after (Post I) and 2 hours after the Qi-training (Post II). The Qi-training enhanced the (O2-) production, reaction velocity and neutrophil adhesion capacity and there were significant differences at Post I compared to before Qi-training (Pre). In addition, the number of white blood cells (WBC), monocytes and lymphocytes were changed significantly through Qi-training. Therefore, it seems that CDSB Qi-training may increase the resistance of trained individuals against common infection and inflammation.
TEACHING NOTE — CUSTOMS UNIONS VS. NON-PREFERENTIAL QUOTAS
Authors: YEH YEONG-HER
Published: March 2003

This paper intends to show that increasing a non-preferential import quota is always superior to joining a customs union, assuming that the customs union is small. However, increasing a non-preferential input quota is not necessarily superior to joining a customs union if the customs union is large and capable of influencing the terms of trade.
Aspergillus fumigatus conidia survive and germinate in acidic organelles of A549 epithelial cells
Authors: Wasylnka Julie A. , Moore Margo M.
Published: March 2003

Aspergillus fumigatus is an environmental mould that can cause invasive disease in the immunocompromised host. Previous work has shown that conidia can be internalized by lung epithelial cells (A549) and murine macrophages (J774) in vitro. Therefore, the purpose of this study was to determine the fate of A. fumigatus conidia within the endosomal network of these cells. Co-localization of conidia expressing green fluorescent protein with proteins present in the early endosomal (CD71) and lysosomal (CD63, LAMP-1) membrane was assessed using confocal microscopy. In J774 cells, 75% of internalized conidia were found in phagosomes containing LAMP-1 120 minutes post-infection. In A549 cells, 55% and 58% of internalized conidia were found to co-localize with LAMP-1 and CD63 by 24 hours. Cathepsin D also co-localized with internalized conidia in A549 cells. Phagosomes containing conidia were shown to be acidified in both cell types. Less than 1%of the initial inoculum survived in J774 cells by 12 hours post-infection. After 24 hours, 3% of internalized conidia survived in A549 cells and 34% of these had germinated. By 36 hours, the germlings were able to escape the phagosome and form extracellular hyphae without lysis of the host cell.
Hydrolysis of Schiff Bases Promoted by UV Light
Authors: Huang Zhaohua , Wan Decheng , Huang Junlian
Published: March 2003

The first hydrolysis of Schiff base under 365 nm UV light is reported. The reaction was affected markedly by the solvent used. It has been successfully applied to the synthesis of compound 2c which is a useful antitumor agent.
Tris(2,4,6-trimethoxyphenyl)phosphine (TTMPP): A Novel Catalyst for Selective Deacetylation
Authors: Yoshimoto Kazuya , Kawabata Hirotoshi , Nakamichi Natsuki , Hayashi Masahiko
Published: March 2003

Chemo- and stereoselective deacetylation was achieved by the use of a catalytic amount of tris(2,4,6-trimethoxyphenyl)phosphine (TTMPP).
Occupational health services at ten U.S. Department of Energy weapons sites
Authors: Salazar Mary K. , Takaro Timothy K. , Gochfeld Michael , Barnhart Scott
Published: March 2003

Background

Nuclear weapons sites are among thousands of federal facilities that are contaminated with a variety of hazardous wastes. Workers at these sites participate in a wide array of activities that can result in their exposure to a variety of hazards.

Methods

The purpose of this study was to describe the occupational health and safety services at ten U.S. Department of Energy sites. Interviews were conducted with 30 health and safety professionals, including physicians, program managers, and industrial hygienists. Data collection was guided by a quality assessment model that provided a means to examine the structures, processes, and outcomes of occupational health and safety services.

Results

It was determined that services for some worker groups, such as subcontractors, were limited; other problems identified included a mismatch between hazards (physical hazards) and types of service providers (radiation experts), ineffective databases, and communication problems.

Conclusions

This description of health and safety services has provided valuable information that can be used to improve the efficiency and effectiveness of service delivery in this large and complex organization. Am. J. Ind. Med. 43:418–428, 2003. © 2003 Wiley‐Liss, Inc.
Historic review:Frederick Challenger, 1887–1983: chemist and biochemist
Authors: Chasteen Thomas G. , Bentley Ronald
Published: March 2003

Frederick Challenger (1887–1983) lived a long life as a chemist and biochemist. He received a PhD for work with O. Wallach at the University of Göttingen in 1912 and a DSc from the University of Birmingham in 1920. After positions at Birmingham, UK, and Manchester, UK, he became Professor of Organic Chemistry at the University of Leeds, UK, in 1930, remaining as Head of the Department until 1953, when he retired as Emeritus Professor. He continued with scientific activity, publishing his final paper in 1978. Much of his work concerned the biological methylation of metalloids such as arsenic, selenium, and tellurium. He determined precise chemical structures for the methylated products and he established a role for adenosylmethionine in the process. An important finding was that the sulfonium compound, (CH3)2S+CH2CH2COO−, was present in several algae and on decomposition led to production of dimethylsulfide. This sulfonium compound was the first of this class to be found in a plant. He had many other wide‐ranging interests, including the organic chemistry of compounds of bismuth and thallium. Copyright © 2003 John Wiley & Sons, Ltd.
Electrochemically reduced tungsten‐based active species as catalysts for cross‐metathesis reactions: cross‐metathesis of non‐functionalized olefins
Authors: Çetinkaya Sevil , Düz Bülent , İmamog̃lu Yavuz
Published: March 2003

The electrochemical reduction of WCl6 results in the formation of an active olefin (alkene) metathesis catalyst. The application of the WCl6–e−–Al–CH2Cl2 catalyst system to cross‐metathesis reactions of non‐functionalized acyclic olefins is reported. Undesirable reactions, such as double‐bond shift isomerization and subsequent metathesis, were not observed in these reactions. Cross‐metathesis of 7‐tetradecene with an equimolar amount of 4‐octene generated the desired cross‐product, 4‐undecene, in good yield. The reaction of 7‐tetradecene with 2‐octene, catalyzed by electrochemically reduced tungsten hexachloride, resulted in both self‐ and cross‐metathesis products. The cross‐metathesis products, 2‐nonene and 6‐tridecene, were formed in larger amounts than the self‐metathesis products of 2‐octene. The optimum catalyst/olefin ratio and reaction time were found to be 1 : 60 and 24 h, respectively. The cross‐metathesis of symmetrical olefins with α‐olefins was also studied under the predetermined conditions. Copyright © 2003 John Wiley & Sons, Ltd.
Recent Developments in the Isonitrile‐Based Multicomponent Synthesis of Heterocycles
Authors: Zhu Jieping
Published: March 2003

Although the synthesis of β‐lactams by means of tethered Ugi reactions has been known since the early 1960s, the 1995 report from Ugi’s group could be regarded as a turning point in the development of novel multicomponent reactions (MCRs) for heterocycle syntheses. Indeed, the number of articles describing isocyanide‐based multicomponent syntheses of heterocycles has increased steadily since then. Although most of these novel MCRs still exploit the archetypal reactivity of isocyanide, its pronounced ability to undergo α‐addition with electrophiles (sp2‐ and sp‐carbon atoms) and nucleophiles, new MCRs have also been discovered as a consequence of exploiting the different secondary reactions of this α‐adduct. Since most of these MCRs were devised on the basis of known bimolecular reactions, judicious combination of reactive functional groups within substrates is of fundamental importance. While the combinatorial principle can help in finding and exploring new MCRs, we would advocate a “substrate‐design approach” in searching for novel MCRs. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
S‐100 proteins in the human peripheral nervous system
Authors: Gonzalez‐Martinez T. , Perez‐Piñera P. , Díaz‐Esnal B. , Vega J.A.
Published: March 2003

This article reviews the distribution of S100 proteins in the human peripheral nervous system. The expression of S100 by peripheral glial cells seems to be a distinctive fact of these cells, independently of their localization and their ability to myelinate or not. S100 proteins expressing cells include satellite cells of sensory, sympathetic and enteric ganglia, supporting cells of the adrenal medulla, myelinating and non‐myelinating Schwann cells in the nerve trunks, and the Schwann‐related cells of sensory corpuscles. In addition, S100 proteins are expressed in peripheral neurons. Most of them express S100α protein, and a subpopulation of sensory neurons in dorsal root ganglia contains S100β protein or S100α plus S100β proteins. Microsc. Res. Tech. 60:633–638, 2003. © 2003 Wiley‐Liss, Inc.
Upregulation of catecholamine biosynthetic enzymes by nitric oxide
Authors: Kim Donghou , Choi Hyun Jin , Kim Seong Who , Cho Sung‐Woo , Hwang Onyou
Published: March 2003

Nitric oxide (NO) is recognized as an essential intercellular messenger in central and peripheral nervous systems. In the present study, whether NO exerts effects on catecholamine (CA) biosynthetic enzymes was determined in primary cultured bovine chromaffin cells. The NO generators sodium nitroprusside (SNP) and S‐nitroso‐N‐acetyl‐D,L‐penicillamine, in a dose‐dependent manner, upregulated transcript levels of tyrosine hydroxylase, dopamine β‐hydroxylase, and phenylethanolamine N‐methyltransferase, accompanied by long‐term increases in their enzyme activities and the intracellular CA levels. The SNP effect was diminished by co‐treatment with LY83583, an inhibitor of soluble guanylate cyclase, or H‐8, a cyclic GMP (cGMP)‐dependent protein kinase inhibitor. Co‐treatment with 8‐Br‐cGMP did not increase further the expression of these enzyme genes induced by SNP. Taken together, the data suggest that NO leads to long‐term upregulation of the CA system via induction of the genes involved and that this is mediated by cGMP‐dependent signaling pathway. © 2003 Wiley‐Liss, Inc.