bluuebunny/crossref_metadata_2025 huggingface dataset:
An effective mixed‐model assembly line sequencing heuristic for just‐in‐time production systems
Authors: Ding Fong‐Yuen , Cheng Liping
Published: October 2002

The commonly accepted objective of sequencing a mixed‐model assembly line for a Just‐In‐Time (JIT) production system is to keep part usage rates at the assembly line close to constant. Sumichrast and Russell evaluated four existing sequencing methods and showed that the best method in achieving this objective is Miltenburg's algorithm 3 using heuristic 2 (M‐A3H2).

This paper presents a much simpler heuristic procedure compared to M‐A3H2. The experiment on 9 problem sets conducted by Sumichrast and Russell is repeated for the new heuristic procedure and M‐A3H2. The results show that the new heuristic procedure is as good as M‐A3H2 in solution quality regarding the mean squared and absolute deviations and much more efficient in computation time. It is further noticed that the computation time required by M‐A3H2 increases much faster than the new heuristic procedure as the number of products increases. Nevertheless, the most important benefit of this new heuristic procedure is its simplicity which should make it very desirable for practitioners.
American and European manufacturing practices: An analytical framework and comparisons
Authors: Vastag Gyula , Whybark D.Clay
Published: October 2002

This paper presents a general analytical framework for making bilateral comparisons of manufacturing practices. The approach suggests a grouping of the data, defines a conservative test called a pure regional effect, and matches the data types to the appropriate statistical tests. The methodology is used to compare manufacturing practices in North America with those in Western Europe using data compiled by the Global Manufacturing Research Group. The broad hypothesis tested is that the two regions are more similar than different. For the two industries studied (small machine tools and nonfashion textiles), this hypothesis holds. Fewer than 10% of the 119 variables investigated have a significant pure regional effect. This suggests that the lack of success of joint ventures between North American and European firms must be attributed to factors other than differences in manufacturing practices. These variables for which significant effects were found reflect differences in external orientation, asset utilization and the management of details. Despite the overall similarities, differences in these factors could be important for American Managers contemplating partnerships with European companies.
What positions nucleosomes? – A model
Authors: Kiyama Ryoiti , Trifonov Edward N
Published: October 2002

Here we propose a new determinant for localization of nucleosomes along genomic DNA, in addition to sequence‐dependent features. The new specific class of chromatin scaling signals involves curved DNA. According to the observed positional distribution of DNA curvature, the new synchronizing signal occurs once per four nucleosomes on average. This new factor in nucleosome positioning should substantially influence the efficiency of biological reactions through regulatory factors microscopically and the entire chromatin structure through the 30 nm fiber structure macroscopically. Allocation of the new type of signals is found to be fixed evolutionarily although they could be shifted in accordance with the hierarchy of functional genomic structures.
Characterization of recombinant human glucuronyltransferase I involved in the biosynthesis of the glycosaminoglycan‐protein linkage region of proteoglycans
Authors: Tone Yuko , Kitagawa Hiroshi , Imiya Kimiyuki , Oka Shogo , Kawasaki Toshisuke , Sugahara Kazuyuki
Published: October 2002

We characterized the recombinant glucuronyltransferase I (GlcAT‐I) involved in the glycosaminoglycan‐protein linkage region biosynthesis. The enzyme showed strict specificity for Galβ1‐3Galβ1‐4Xyl, exhibiting negligible incorporation into other galactoside substrates including Galβ1‐3Galβ1‐O‐benzyl, Galβ1‐4GlcNAc and Galβ1‐4Glc. A comparison of the GlcAT‐I with another β1,3‐glucuronyltransferase involved in the HNK‐1 epitope biosynthesis revealed that the two β1,3‐glucuronyltransferases exhibited distinct and no overlapping acceptor substrate specificities in vitro. Nevertheless, the transfection of the GlcAT‐I cDNA into COS‐1 cells induced the significant expression of the HNK‐1 epitope. These results suggested that the high expression of the GlcAT‐I gene rendered the cells capable of synthesizing the HNK‐1 epitope.
Cognitive patterns in subtypes of schizophrenia
Authors: Brazo P. , Marié R.M. , Halbecq I. , Benali K. , Segard L. , Delamillieure P. , Langlois-Théry S. , Van Der Elst A. , Thibaut F. , Petit M. , Dollfus S.
Published: October 2002

Aim

Because of the heterogeneity of schizophrenia, this study researched different cognitive patterns in distinct subtypes of schizophrenic patients.

Methods

Thirty-five Diagnostic and Statistical Manual IV (DSM IV) schizophrenic patients and 35 healthy controls were included. Patients were categorized into deficit, disorganized and positive subtypes with the schedule for the deficit syndrome (SDS) and the positive and negative syndrome scale (PANSS). Executive/attentional functions were assessed with the modified card sorting test (MCST), a test of verbal fluency, the trail making test (TMT) and the Stroop color-word test (Stroop test). Episodic memory was explored through the California verbal learning test (CVLT).

Results

The positive subtype had some executive/attentional (fluency and Stroop tests) and mnesic performances in the normal range, suggesting the preservation of good cognitive skills. In contrast, the deficit and disorganized subtypes had major mnesic and executive/attentional dysfunctions compared to healthy subjects. The deficit subtype compared to the control group performed predominantly worse on the MCST and fluency, whereas the disorganized subtype had the lowest scores on the TMT and the Stroop test.

Conclusion

This study showed distinct cognitive patterns in deficit, disorganized and positive patients in comparison with the controls, suggesting a heterogeneous cognitive dysfunction in schizophrenia.
Forces on particles in oscillatory boundary layers
Authors: FISCHER PAUL F. , LEAF GARY K. , RESTREPO JUAN M.
Published: October 2002

The lift and drag forces on an isolated particle resulting from an oscillating wall-
bounded flow, are approximated using direct numerical simulation and extrapolation
techniques. We also confirm the existence of anomalies in the lift force, which arise
from the interaction of the vortical field with the particle. Anomalies can also occur
for computational reasons and these are discussed as well.

This study was motivated by a long-standing question about the importance of lift
forces in the dynamics of sediments in oceanic settings. To answer this question we
use the numerically generated data as well as extrapolations to compute the ratio
of the lift to buoyancy forces on a particle. This analysis suggests that for particles
and oceanic conditions typical of the nearshore, the lift force can play a role in the
dynamics of sedimentary beds.
The effect of quantum oscillation in plasmas
Authors: SHOKRI B.
Published: October 2002

Making use of the dielectric permitivitty of a solid state plasma obtained
from linearizing a quantum hydrodynamic equation, volume and surface waves
in cold semibounded plasma-like media and thin layers of solid state plasmas are
investigated in the presence and absence of an external magnetic field. It is shown
that quantum oscillation of free charged particles and its spatial dispersion even
in cold plasmas lead to new spectra of collective oscillations. Furthermore, a new
volume ion-acoustic-type wave is obtained with a quadratic dependence on the
wavenumber in the long-wavelength limit. Moreover, it is shown that quantum
oscillation affects the surface wave spectrum and extends it to a wider frequency
region.
Intertidal meiofauna of the St Lawrence estuary (Quebec, Canada): diversity, biomass and feeding structure of nematode assemblages
Authors: Tita G. , Desrosiers G. , Vincx M. , Clément M.
Published: October 2002

The meiofauna of the St Lawrence estuary was investigated in the intertidal zone of the Parc du Bic (Quebec, Canada). Five nematode assemblages were distinguished by a cluster analysis: A1 and A2 (upper-tide level); A3 (mid-tide level); A4 and A5 (low-tide level). Discriminant function analysis showed that exposure time during low tide was the most important environmental factor in determining differences between assemblages. Chlorophyll-a, phaeopigments, sediment water content, and per cent of silt followed in the same order. Nematode densities (400–1500 ind 10 cm−2) were found to be lower than those generally reported for other estuarine intertidal zones of the eastern Atlantic coast. Mean nematode biomass in the five assemblages ranged between 96±14 and 248±86 μg Corg 10 cm−2. Deposit feeders were generally the dominant nematode feeding group in terms of abundance and biomass. Correlation of epigrowth-feeders with chlorophyll-a and phaeopigments, respectively, suggested that in the upper-tide level, old or partially degraded phytodetritus contribute more to the diet of this nematode feeding group; and in the low-tide level epigrowth-feeders may rely more on ‘fresher’ phytodetritus.
Caprella caulerpensis (Crustacea: Amphipoda), a new species associated with Caulerpa prolifera from the Strait of Gibraltar
Authors: Guerra-García J.M. , Sánchez-Moyano J.E. , García-Gómez J.C.
Published: October 2002

A new species of the genus Caprella (Crustacea: Amphipoda: Caprellidea) is described based on the specimens collected from the Strait of Gibraltar, southern Spain. The new species, Caprella caulerpensis, was found living in mud bottoms with the seaweed Caulerpa prolifera (Forskål) Lamouroux. Caprella caulerpensis can be distinguished from the most related species, Caprella rapax, mainly by the number of articles in the flagellum of antenna 1, the morphology of the dactylus of gnathopod 2 and the pereonites length.
Can low sea urchin densities control macro-epiphytic biomass in a north-east Atlantic maerl bed ecosystem (Bay of Brest, Brittany, France)?
Authors: Guillou Monique , Grall Jacques , Connan Solène
Published: October 2002

The distribution, abundance and feeding behaviour of sea urchins (Paracentrotus lividus, Psammechinus miliaris, Sphaerechinus granularis) and the macro-algal biomass were assessed in two maerl beds within a north-east Atlantic coastal ecosystem (Bay of Brest, Brittany, France). To study the possible control of herbivorous sea urchins on the macrophytic algae, one maerl bed under the influence of urban sewage (northern site) was compared to one less influenced by urban and industrial outlets (southern site). Macrophytic biomass in the northern site was estimated as 40-fold higher than in the southern site where sea urchins were, on average, 38-times more numerous. Preliminary results support the hypothesis that grazing of sea urchin, even in low densities, can be a factor regulating the macrophytic biomass on maerl beds except in too nutrient enriched environments. So in the northern basin of the Bay, data pointed out the role of anthropogenic impacts on macrophytic biomass increase which was concomitant with the progressive disappearance of sensitive herbivorous species like sea urchins, both processes result in change in the ecosystem.
Northern krill, Meganyctiphanes norvegica, come up to see the last eclipse of the millennium?
Authors: Strömberg J.-O. , Spicer J.I. , Liljebladh B. , Thomasson M.A.
Published: October 2002

Most krill species undergo diel vertical migration (DVM) which is to some extent influenced by light intensity. During a solar eclipse (11 August 1999) the upward and downward movement of krill, Meganyctiphanes norvegica, inhabiting a Swedish fjord followed closely changes in light intensity. Here the eclipse was partial (77%) and the weather overcast and yet krill at 70–90 m depth were able to detect, and respond to very small changes in light. This observation of an event during mid-day which is not pre-programmed confirms light as an important triggering mechanism for krill DVM.
Refiguring the Body: Performance of Identity in Mapantsula and Fools
Authors: Magogodi Kgafela Oa
Published: October 2002

Two South African films, Oliver Schmitz's 1988 Mapantsula and Ramadan Suleman's 1997 Fools, drawing from the revolutionary fervour of Third Cinema, developed a radical consciousness against a backdrop of Anglo-Afrikaner cinema in South Africa. Set in Soweto during the 1980s, both films, in their representation of blackness, address issues of the body, identity and agency. With their anti-heroes at the centre, they explore questions of African identity by imaging the black body differently, and free it from the grip of the apartheid imaginary. Meanwhile, the white body in the films is ‘shot’ as a homogenized symbol of apartheid violence and oppression, thus ‘fixing’ white identity as a strategy for political truth claiming.
Epidemiology of measles in Blantyre, Malawi: analyses of passive surveillance data from 1996 to 1998
Authors: YAMAGUCHI S. , DUNGA A. , BROADHEAD R. L. , BRABIN B. J.
Published: October 2002

Measles surveillance data in Blantyre, Malawi were reviewed for 1996–8 to describe the epidemiology of infection and to estimate vaccine efficacy (VE) by the screening method. A total of 674 measles cases were reported to the Blantyre District Health Office during this period. Age distribution showed that 108 (16.1%) of the cases were aged less than 1 year. The median age was 5 years. Eighty percent of the cases between 1 and 19 years had been previously vaccinated. VE was 68.6% (95% CI, 52.7–79.2) for children 12–23 months of age and 67.3% (95% CI, 48.3–79.3) for infants 9–11 months of age. Reasons for this low vaccine efficacy are discussed. Previous vaccination history was negatively associated with the risk for developing cough during measles infection (odds ratio (OR), 0.30; 95% CI, 0.09–0.91), diarrhoea (OR, 0.64; CI, 0.44–0.95) and pneumonia (OR, 0.40; CI, 0.25–0.62). Logistic regression analysis showed that pneumonia in adults was negatively associated with vaccination history. The passive surveillance system for measles in Malawi was useful to describe the epidemiology of measles.
Relationship between home food-handling practices and sporadic salmonellosis in adults in Louisiana, United States
Authors: KOHL K. S. , RIETBERG K. , WILSON S. , FARLEY T. A.
Published: October 2002

Salmonellosis is the leading cause of death caused by foodborne bacterial pathogens in the United States. Approximately 90% of salmonella infections are sporadic, but most of what is known about salmonellosis has come from outbreak investigations. We studied the risk for sporadic salmonellosis among 115 persons aged [ges ]15 years reported to the Louisiana Office of Public Health during May 1998–April 1999, compared with 115 age-matched controls. Significantly more case-patients than controls had chronic underlying medical conditions [adjusted odds ratio (aOR) = 4.3; 95% confidence interval (CI) = 2.2–8.7]. Although reported consumption of specific food items likely to contain salmonella was not associated with illness, inconsistent handwashing between preparation of meat and non-meat items was associated with illness (aOR = 8.3; CI = 1.1–61.8). Enhanced measures to provide a consistently safe food supply and promote safer food preparation in households will depend on prevention of sporadic salmonellosis.
Urban biography: Scotland, 1700–2000
Authors: Morris R. J.
Published: October 2002

Urban biographies are growing in numbers upon the shelves. A clutch of mainly English ones were reviewed recently in these pages by David Reeder with a sense of cautious enthusiasm and warnings about the dangers of fragmentation in these often topic-oriented multi-authored volumes. Recent examples include Donald Miller's 1996 study of Chicago, an example of unashamedly scholarly boosterism. The massive Burrows and Wallace study of New York followed in 1999 and presented a detailed episodic account of the city. In 1,383 pages they have still only got to 1898. This book displayed a love of city with overwhelming knowledge, but presented a very readable story for those with stamina. Scotland already has the two Glasgow volumes, also included in Reeder's review. To this have now been added multi-authored studies of Aberdeen and Dundee and two more accounts of Glasgow
Microvascular Cell Death in Spontaneously Hypertensive Rats During Experimental Inflammation
Authors: MUN KYO C. , DELANO FRANK A. , TRAN EDWARD D. , SCHMID‐SCHÖNBEIN GEERT W.
Published: October 2002

Objective: Chronic hypertension is associated with an increased risk for tissue injury that may be mediated in part by endothelium and inflammatory cells. To clarify a possible underlying mechanisms, we examined leukocyte migration in the microcirculation and concomitant parenchymal cell death.

Methods: The mesentery of spontaneously hypertensive rats (SHRs) and their normotensive controls, Wistar Kyoto (WKY) rats, was examined with digital fluorescence microscopy after topical stimulation with an inflammatory mediator (f‐met‐leu‐phe, 10−8M). The migratory pathways of individual leukocytes were traced, and at the same time cell death was detected by use of a life‐death indicator (propidium iodide) over a period of 3 hours.

Results: Both WKY and SHR had a progressively increasing number of leukocytes migrating across the endothelium in postcapillary venules into the tissue parenchyma. But parenchymal cell death was detected in a random pattern in the mesentery tissue, without correlation to the migratory positions of the leukocytes. Although mature SHR rats (about 17 weeks) exhibited the same level of cell death as age‐matched WKY rats, older WKY rats (about 30 weeks) had significantly lower levels of cell death, whereas the SHR rats maintained the same number of parenchymal cell death as mature animals.

Conclusions: These results suggest that in the presence of an inflammatory mediator, the SHR may exhibit a stronger response to an inflammatory mediator than normotensive WKY rats in a fashion that is age, but not blood pressure, dependent. Parenchymal cell death does not correlate with migration of activated leukocytes at the microvascular level.
Persistence of Impaired Hepatic Microcirculation After Nonarterialized Liver Transplantation in the Rat
Authors: TAWADROUS MICHAEL N. , ZIMMERMANN ARTHUR , ZHANG XING‐YI , WHEATLEY ANTONY M.
Published: October 2002

Objectives: The nonarterialized orthotopic rat liver transplant (NOLT) is a frequently used model in transplantation research that was recently used to investigate microcirculatory alterations during acute rejection, which occurs within 7 days. The present study sought to establish whether NOLT represents a reasonable model for the study of the hepatic microcirculation beyond the immediate reperfusion phase.

Methods: Three groups of animals were studied: sham‐operated control (n= 8), NOLT (n= 7) and arterialized orthotopic liver transplant (AOLT; n= 8). The hepatic microcirculation was investigated by intravital fluorescence microscopy and laser Doppler flowmetry (LDF) on day 7 postoperatively. Liver histology and plasma levels of liver enzymes were also assessed.

Results: Plasma levels of aspartate aminotransferase, alanine aminotransferase, and bilirubin were significantly higher in NOLT than in AOLT and control animals. The low LDF signal recorded from the surface of the NOLT liver (92 ± 25 vs. 210 ± 25 and 172 ± 14 PU in AOLT and control liver, respectively; p < 0.05) was associated with heterogeneous perfusion at both the lobular and sinusoidal levels (density of perfused sinusoids (n/40,000 µm2): 5.8 ± 0.8, 8.1 ± 0.3, 8.0 ± 0.3, respectively; p < 0.05). The percentage of hyperfluorescent Ho342‐stained hepatocytes (apoptotic) ranged between 2 and 5% and was not significantly different between groups. The lack of post‐transplant arterial supply was associated with an increased hepatic cord width‐to‐sinusoid diameter ratio (3.77 ± 0.3, 2.02 ± 0.04, and 1.72 ± 0.06 in NOLT, AOLT, and control animals, respectively; p < 0.001 vs. control and AOLT) and increased temporary leukocyte adherence to the walls of the terminal hepatic venules. Intense vitamin A autofluorescence around shunt‐ and large‐diameter, slow‐velocity vessels was occasionally encountered in the NOLT liver, which coincided with mild fibrosis and bile ductular proliferation. In the well‐perfused areas, both AOLT and NOLT were associated with a significant rise in sinusoidal RBCvel, which was more marked in the NOLT group.

Conclusions: Our data indicate that NOLT represents an inappropriate model for the long‐term study of the hepatic microcirculation. Lack of a post‐transplant arterial supply may lead to persistent microvascular perfusion failure, hepatocellular/endothelial cell swelling, and microvascular anomalies related to bile duct injury. Recovery from microcirculatory alterations induced by cold preservation/reperfusion injury appears to depend on an intact hepatic arterial blood supply.
Early Salt Stress Effects on the Changes in Chemical Composition in Leaves of Ice Plant and Arabidopsis. A Fourier Transform Infrared Spectroscopy Study
Authors: Yang Jyisy , Yen Hungchen E.
Published: October 2002

A technique based on Fourier transform infrared (FT-IR) spectrometry was developed to detect the corresponding changes in chemical composition associated with the rapid changes in sodium and water content in 200 mm NaCl-stressed halophyte ice plants (Mesembryanthemum crystallinum). The changes in glycophyte Arabidopsis stressed with 50 mm NaCl were also examined for comparison. The obtained IR spectra were further processed by deconvolution and curve fitting to examine the chemical nature of the responding sources in the leaves. Using three stages of ice plant leaves, absorption bands corresponding to carbohydrates, cell wall pectin, and proteins were identified, with distinct IR spectra representing each developmental stage. Within 48 h of mild salt stress, the absorption band intensities in the fingerprint region increased continuously in both plants, suggesting that the carbon assimilation was not affected at the early stage of stress. The intensities of ester and amide I absorption bands decreased slightly in Arabidopsis but increased in ice plant, suggesting that the cell expansion and protein synthesis ceased in Arabidopsis but continued in ice plant. In both plants, the shift in amide I absorption band was observed hourly after salt stress, indicating a rapid conformational change of cellular proteins. Analyses of the ratio between major and minor amide I absorption band revealed that ice plant was able to maintain a higher-ordered form of proteins under stress. Furthermore, the changes in protein conformation showed a positive correlation to the leaf sodium contents in ice plant, but not in Arabidopsis.
A Comparison of Oligogalacturonide- and Auxin-Induced Extracellular Alkalinization and Growth Responses in Roots of Intact Cucumber Seedlings
Authors: Spiro Mark D. , Bowers Jonathan F. , Cosgrove Daniel J.
Published: October 2002

Oligogalacturonic acid (OGA) affects plant growth and development in an antagonistic manner to that of the auxin indole-3-acetic acid (IAA), the mechanism by which remains to be determined. This study describes the relationship between IAA and OGA activity in intact cucumber (Cucumis sativus) seedlings. Both OGA and IAA induced rapid and transient extracellular alkalinization; however, the characteristics of the OGA and IAA responses differed in their kinetics, magnitude, calcium dependence, and region of the root in which they induced their maximal response. IAA (1 μm) induced a saturating alkalinization response of approximately 0.2 pH unit and a rapid reduction (approximately 80%) in root growth that only partially recovered over 20 h. OGAs, specifically those with a degree of polymerization of 10 to 13, induced a maximal alkalinization response of 0.48 pH unit, but OGA treatment did not alter root growth. Saturating concentrations of OGA did not block IAA-induced alkalinization or the initial IAA-induced inhibition of root growth but allowed IAA-treated roots to recover their initial growth rate within 270 min. IAA-induced alkalinization occurs primarily in the growing apical region of the root, whereas OGA induced its maximal response in the basal region of the root. This study demonstrates that OGA and IAA act by distinct mechanisms and that OGA does not simply act by inhibition of IAA action. These results also suggest that IAA-induced extracellular alkalinization is not sufficient to account for the mechanism by which IAA inhibits root growth.
Tomato Plants Ectopically Expressing Arabidopsis CBF1 Show Enhanced Resistance to Water Deficit Stress
Authors: Hsieh Tsai-Hung , Lee Jent-turn , Charng Yee-yung , Chan Ming-Tsair
Published: October 2002

A DNA cassette containing an Arabidopsis C repeat/dehydration-responsive element binding factor 1 (CBF1) cDNA and a nos terminator, driven by a cauliflower mosaic virus 35S promoter, was transformed into the tomato (Lycopersicon esculentum) genome. These transgenic tomato plants were more resistant to water deficit stress than the wild-type plants. The transgenic plants exhibited growth retardation by showing dwarf phenotype, and the fruit and seed numbers and fresh weight of the transgenic tomato plants were apparently less than those of the wild-type plants. Exogenous gibberellic acid treatment reversed the growth retardation and enhanced growth of transgenic tomato plants, but did not affect the level of water deficit resistance. The stomata of the transgenic CBF1 tomato plants closed more rapidly than the wild type after water deficit treatment with or without gibberellic acid pretreatment. The transgenic tomato plants contained higher levels of Pro than those of the wild-type plants under normal or water deficit conditions. Subtractive hybridization was used to isolate the responsive genes to heterologousCBF1 in transgenic tomato plants and theCAT1 (CATALASE1) was characterized. Catalase activity increased, and hydrogen peroxide concentration decreased in transgenic tomato plants compared with the wild-type plants with or without water deficit stress. These results indicated that the heterologous Arabidopsis CBF1 can confer water deficit resistance in transgenic tomato plants.
The COBRA Family of Putative GPI-Anchored Proteins in Arabidopsis. A New Fellowship in Expansion
Authors: Roudier François , Schindelman Gary , DeSalle Rob , Benfey Philip N.
Published: October 2002

Identification of regulatory molecules that determine the extent and direction of expansion is necessary to understand how cell morphogenesis is controlled in plants. We recently identifiedCOB (COBRA) as a key regulator of the orientation of cell expansion in the root. Analysis of the Arabidopsis genome sequence indicated that COB belongs to a multigene family consisting of 12 members, all predicted to encode glycosylphosphatidylinositol-anchored proteins. All but two of theCOBL (COB-like) genes are expressed in most organs examined, suggesting possible redundancy. Sequence comparisons, phylogenetic analyses, and exon-intron positions revealed that the COB family is composed of two main subgroups sharing a common architecture, one subgroup being characterized by an additional N-terminal domain. Identification of expressed sequence tags corresponding to potential orthologs in other plant species suggested that COB-related functions are required in all vascular plants. Together, these results indicate that COB family members are likely to be important new players at the plasma membrane-cell wall interface.
Distinct N-Terminal Regulatory Domains of Ca2+/H+ Antiporters
Authors: Pittman Jon K. , Sreevidya Coimbatore S. , Shigaki Toshiro , Ueoka-Nakanishi Hanayo , Hirschi Kendal D.
Published: October 2002

The regulation of intracellular Ca2+ levels is achieved in part by high-capacity vacuolar Ca2+/H+ antiporters. An N-terminal regulatory region (NRR) on the Arabidopsis Ca2+/H+antiporter CAX1 (cation exchanger 1) has been shown previously to regulate Ca2+ transport by a mechanism of N-terminal auto-inhibition. Here, we examine the regulation of other CAX transporters, both within Arabidopsis and from another plant, mung bean (Vigna radiata), to ascertain if this mechanism is commonly used among Ca2+/H+ antiporters. Biochemical analysis of mung bean VCAX1 expressed in yeast (Saccharomyces cerevisiae) showed that N-terminal truncated VCAX1 had approximately 70% greater antiport activity compared with full-length VCAX1. A synthetic peptide corresponding to the NRR of CAX1, which can strongly inhibit Ca2+ transport by CAX1, could not dramatically inhibit Ca2+ transport by truncated VCAX1. The N terminus of Arabidopsis CAX3 was also shown to contain an NRR. Additions of either the CAX3 or VCAX1 regulatory regions to the N terminus of an N-terminal truncated CAX1 failed to inhibit CAX1 activity. When fused to N-terminal truncated CAX1, both the CAX3 and VCAX1 regulatory regions could only auto-inhibit CAX1 after mutagenesis of specific amino acids within this NRR region. These findings demonstrate that N-terminal regulation is present in other plant CAX transporters, and suggest distinct regulatory features among these transporters.
Bundle Sheath Diffusive Resistance to CO2 and Effectiveness of C4 Photosynthesis and Refixation of Photorespired CO2 in a C4 Cycle Mutant and Wild-Type Amaranthus edulis
Authors: Kiirats Olavi , Lea Peter J. , Franceschi Vincent R. , Edwards Gerald E.
Published: October 2002

A mutant of the NAD-malic enzyme-type C4 plant,Amaranthus edulis, which lacks phosphoenolpyruvate carboxylase (PEPC) in the mesophyll cells was studied. Analysis of CO2 response curves of photosynthesis of the mutant, which has normal Kranz anatomy but lacks a functional C4 cycle, provided a direct means of determining the liquid phase-diffusive resistance of atmospheric CO2 to sites of ribulose 1,5-bisphosphate carboxylation inside bundle sheath (BS) chloroplasts (r  bs) within intact plants. Comparisons were made with excised shoots of wild-type plants fed 3,3-dichloro-2-(dihydroxyphosphinoyl-methyl)-propenoate, an inhibitor of PEPC. Values of r  bs in A. edulis were 70 to 180 m2 s−1mol−1, increasing as the leaf matured. This is about 70-fold higher than the liquid phase resistance for diffusion of CO2 to Rubisco in mesophyll cells of C3 plants. The values of r  bs in A. edulis are sufficient for C4 photosynthesis to elevate CO2 in BS cells and to minimize photorespiration. The calculated CO2 concentration in BS cells, which is dependent on input of r  bs, was about 2,000 μbar under maximum rates of CO2 fixation, which is about six times the ambient level of CO2. High re-assimilation of photorespired CO2 was demonstrated in both mutant and wild-type plants at limiting CO2 concentrations, which can be explained by high r  bs. Increasing O2 from near zero up to ambient levels under low CO2, resulted in an increase in the gross rate of O2 evolution measured by chlorophyll fluorescence analysis in the PEPC mutant; this increase was simulated from a Rubisco kinetic model, which indicates effective refixation of photorespired CO2 in BS cells.
Expression Profiling of the Whole Arabidopsis Shaggy-Like Kinase Multigene Family by Real-Time Reverse Transcriptase-Polymerase Chain Reaction
Authors: Charrier Bénédicte , Champion Anthony , Henry Yves , Kreis Martin
Published: October 2002

The recent publication of the complete sequence of the Arabidopsis genome allowed us to identify and characterize the last two members of the SHAGGY-like kinase (AtSK) gene family. As a result, the study of the overall spatio-temporal organization of the whole AtSK family in Arabidopsis has become an achievable and necessary aim to understand the role of each SHAGGY-like kinase during plant development. An analysis of the transcript level of the 10 members of the family has been performed using the technique of real-time quantitative reverse transcriptase-polymerase chain reaction. Transcript levels in several organs, under different growth conditions, were analyzed. To calibrate the results obtained, a number of other genes, such as those coding for the two MAP3Kεs and the two MAP4Kαs, as well as the stress response marker RD29A; the small subunit of the Rubisco photosynthetic enzyme Ats1A; the MEDEA chromatin remodeling factor; and the SCARECROW, ASYMMETRIC LEAVES 1, and SUPERMAN transcription factors all involved in key steps of plant development were used. The analysis of our data revealed that eight of the 10 genes of the AtSK family displayed a pseudo-constitutive expression pattern at the organ level. Conversely,AtSK13 responded to osmotic changes and saline treatment, whereas AtSK31 was flower specific and responded to osmotic changes and darkness.
UK data warehousing and business intelligence implementation
Authors: Dobbs Tony , Stone Merlin , Abbott Julie
Published: October 2002

This paper summarises the situation regarding the penetration of data warehouses and business intelligence systems in companies across a range of industries in the UK. Data warehouses are being implemented due to the business need for tools within companies today to analyse the increasing amounts of data being collected. The paper then presents a short case study describing an example of a successful implementation of a business intelligence solution that supports CRM in a major retailer. Points are emphasised via the use of results from a recent IBM‐sponsored qualitative study done in the UK.
Understanding the Dynamics of Populations
Authors: Stenseth Nils Chr.
Published: October 2002

Analysis and Management of Animal Populations
. Modeling, Estimation, and Decision Making. Byron K. Williams, James D. Nichols, and Michael J. Conroy. Academic Press, San Diego, 2002. 835 pp. $99.95, £69. ISBN 0-12-754406-2.

The authors provide students, professional ecologists, and wildlife managers with a practice-oriented reference that integrates the many strands of population ecology.
Use of the transannular DielsAlder (TADA) reaction to probe biological receptors: Rational design and synthesis of tricyclic TADA adducts capable of rigidly holding pharmacophore parts
Authors: Chantigny Yves A , Dory Yves L , Toró András , Deslongchamps Pierre
Published: October 2002

Transannular DielsAlder (TADA) adducts constitute a collection of rigid structures, whose conformational diversity is rich. It is possible to design such specifically functionalized molecules capable of binding to known biological targets by molecular modelling MCSSHOOK (multiple copy simultaneous search). Here we show that such carefully designed compounds can be easily built from small synthons. TADA adducts are very interesting due to their huge conformational diversity, their rigidity (biological interest), and their ease of synthesis (chemical interest).Key words: tricycles, synthesis, transannular DielsAlder, macrocyclization, conformation, diversity.
Electrochemical oxidation of 6-propionyl-2-(N,N-dimethylamino)naphthalene (prodan) in acetonitrile on Pt electrodes: Reversible dimerization of prodan radical cations
Authors: Moressi Marcela Beatriz , Zón María Alicia , Fernández Héctor
Published: October 2002

The electrooxidation of 6-propionyl-2-(N,N-dimethylamino)naphthalene (prodan) has been investigated for the first time. It has been performed on both conventional size platinum electrodes and platinum ultramicroelectrodes in acetonitrile by cyclic voltammetry with convolution analysis and controlled-potential electrolysis. The voltammetric responses at room temperature are similar to those corresponding to a kinetically controlled anodic electron-transfer process. Cyclic voltammetry measurements were also carried out at different concentrations of prodan and at different temperatures. Chemical transformation of the radical monocation formed after the electrochemical oxidation of prodan, as deduced from reverse controlled potential bulk electrolysis and cyclic voltammetry measurements, gives evidence for the reversible dimerization of prodan radical cations. Both diagnostic criteria and digital simulation confirm that radicalradical coupling is the reversible chemical reaction coupled to the initial electron transfer step, to give the corresponding dimeric dication. The kinetic and thermodynamic parameters for the first electron transfer reaction and the dimerization process were estimated from digital simulation at 293 K. Values of 8.0 × 106 M1 and 3.2 × 105 M1 s1 were determined for the dimerization reaction equilibrium constant and the dimer formation rate constant, respectively. The diffusion coefficient of prodan was determined from both limiting currents from convoluted cyclic voltammograms as well as limiting currents on ultramicroelectrodes. For such cases where the electron number exchanged in the electrode process is unknown, a method derived from the combination of data previously indicated is also proposed to obtain the diffusion coefficient of the electroactive species.Key words: prodan, cyclic voltammetry, reaction mechanism, reversible dimerization, electron transfer reactions, radical cation.
Thermal oscillations in the bromate  oxalic acid  MnSO4 H2SO4 acetone system: A calorimetric study
Authors: Biswas Sudeshna , Mukherjee Kallol , Mukherjee Dulal Chandra , Moulik Satya Priya
Published: October 2002

The oscillatory reaction of potassium bromate, oxalic acid, and MnSO4in the presence of acetone in aq H2SO4solutions has been studied calorimetrically at different concentrations of substrates. Acetone and oxalic acid have been found to accelerate the reaction by increasing the oscillation frequency. On the other hand, MnSO4has a retarding effect; the frequency of oscillation decreases systematically with increasing concentration of MnSO4. Potassium bromate shows mixed behavior in this respect. The total heat evolved during the reaction per mol of oxalic acid consumed has been evaluated, which can be used to calculate the concentrations of the various reactants at different stages of the reaction. The effects of different electrolytes (KCl, NaCl, BaCl2, CaCl2, SrCl2, NaBr, NaI, KNO3, NaNO3, and Ca(NO3)2) and solvents (dimethylformamide, 1,4-dioxane, acetonitrile, and tetrahydrofuran) on the extents of oscillation and the enthalpy change for the process have been also examined.Key words: BelousovZhabotinsky reaction, oscillatory reaction, oxalic acid, calorimetry, acetone.
Stochastic conformational search on the Lewis X (Lex) trisaccharide and three Lexanalogues
Authors: Auzanneau France-Isabelle , Sourial Elizabeth , Schmidt Jonathan M , Feher Miklos
Published: October 2002

Biased stochastic conformational searches using the MMFF94 force field and the Born continuum solvation model were applied to the molecular modeling of the Lewis X (Lex) trisaccharide (β-D-Gal-(1,4)-[α-L-Fuc-(1,3)]-β-D-GlcNAc-OH) and three Lexanalogues, in which each of the three sugar units was replaced by another sugar residue, i.e., N-acetyl-glucosamine by glucose, galactose by glucose, and fucose by rhamnose. The stochastic search accurately identified a lowest energy conformation of the Lexdeterminant that corresponds to the reported conformations of Lexdeduced experimentally in the solid state by X-ray crystallography and in solution by NMR measurements. In this conformation stacking exists between the galactosyl and fucosyl residues. Five new local minima for the Lextrisaccharide were found within 3 kcal mol1of the global minimum using the stochastic search and metric scaling. Modeling studies of the analogues showed that the stacking observed in the Lextrisaccharide was maintained when either galactosyl or N-acetylglucosamine were replaced by glucosyl residues. In contrast, substitution of the fucose residue by rhamnose led to two conformers in which stacking of the galactose and rhamnose residues was no longer maintained. These results indicate that the substitution of the non-reducing end galactosyl or N-acetyl-glucosaminyl residues by a glucose unit in the dimeric Lewis X (dimLex) tumour associated antigen could help in the development of a vaccine that cross-reacts with dimLexbut no longer displays Lexassociated three-dimensional epitopes also presented by non-cancerous cells. In contrast, an analogue in which the fucosyl residue is replaced by rhamnose does not constitute a good vaccine candidate, since our results indicate that this substitution will induce an important conformational change that is likely to abolish cross-reactivity with the natural dimLextumor associated antigen.Key words: molecular modeling, stochastic, conformational analysis, Lewis X, oligosaccharide.
Optimal Short-Term Population Coding: When Fisher Information Fails
Authors: Bethge M. , Rotermund D. , Pawelzik K.
Published: October 2002

Efficient coding has been proposed as a first principle explaining neuronal response properties in the central nervous system. The shape of optimal codes, however, strongly depends on the natural limitations of the particular physical system. Here we investigate how optimal neuronal encoding strategies are influenced by the finite number of neurons N (place constraint), the limited decoding time window length T (time constraint), the maximum neuronal firing rate fmax (power constraint), and the maximal average rate fmax (energy constraint). While Fisher information provides a general lower bound for the mean squared error of unbiased signal reconstruction, its use to characterize the coding precision is limited. Analyzing simple examples, we illustrate some typical pitfalls and thereby show that Fisher information provides a valid measure for the precision of a code only if the dynamic range (fmin T, fmax T) is sufficiently large. In particular, we demonstrate that the optimal width of gaussian tuning curves depends on the available decoding time T. Within the broader class of unimodal tuning functions, it turns out that the shape of a Fisher-optimal coding scheme is not unique. We solve this ambiguity by taking the minimum mean square error into account, which leads to flat tuning curves. The tuning width, however, remains to be determined by energy constraints rather than by the principle of efficient coding.
Bayesian Model Assessment and Comparison Using Cross-Validation Predictive Densities
Authors: Vehtari Aki , Lampinen Jouko
Published: October 2002

In this work, we discuss practical methods for the assessment, comparison, and selection of complex hierarchical Bayesian models. A natural way to assess the goodness of the model is to estimate its future predictive capability by estimating expected utilities. Instead of just making a point estimate, it is important to obtain the distribution of the expected utility estimate because it describes the uncertainty in the estimate. The distributions of the expected utility estimates can also be used to compare models, for example, by computing the probability of one model having a better expected utility than some other model. We propose an approach using cross-validation predictive densities to obtain expected utility estimates and Bayesian bootstrap to obtain samples from their distributions. We also discuss the probabilistic assumptions made and properties of two practical cross-validation methods, importance sampling and k-fold cross-validation. As illustrative examples, we use multilayer perceptron neural networks and gaussian processes with Markov chain Monte Carlo sampling in one toy problem and two challenging real-world problems.
Risk factors for acute graft-versus-host disease in patients undergoing transplantation with CD34+ selected blood cells from HLA-identical siblings
Authors: Urbano-Ispizua Alvaro , Rozman Ciril , Pimentel Pedro , Solano Carlos , de la Rubia Javier , Brunet Salut , Pérez-Oteyza Jaime , Ferrá Christelle , Zuazu Javier , Caballero Dolores , Bargay Joan , Carvalhais Alzira , Dı́ez Jose Luis , Espigado Ildefonso , Alegre Adrián , Rovira Montserrat , Campilho Fernando , Odriozola Jesús , Sanz Miguel Angel , Sierra Jordi , Garcı́a-Conde Javier , Montserrat Emili
Published: October 2002

A study on 315 patients undergoing transplantation with CD34+ selected blood cells from HLA-identical siblings was performed to determine risk factors for acute GVHD (aGVHD). Recipients of a dose of CD34+ cells (× 106/kg) of 2 or less, more than 2 to 4, and more than 4 had a cumulative incidence of aGVHD grades I-IV of 21%, 35%, and 43%, respectively (log-rankP = .01); similarly, recipients of a dose of CD3+ cells (× 106/kg) of 0.05 or less, more than 0.05 to 0.1, and more than 0.1 had a cumulative incidence of aGVHD grades I-IV of 18%, 35%, and 44%, respectively (log-rankP = .007). Using a Cox regression model, 4 independent factors for aGVHD I-IV were identified: increased CD34+cell dose (P = .02), increased CD3+ cell dose (P = .02), female patients (P = .01), and higher patient age (> 42 years) (P = .007). This study shows, for the first time in T-cell–depleted transplantations, a positive correlation between the number of CD34+ cells and aGVHD and, also, that the number of CD3+ cells necessary to initiate aGVHD is lower than previously reported.
Temporary increase in the risk for recurrence during pregnancy in women with a history of venous thromboembolism
Authors: Pabinger Ingrid , Grafenhofer Helga , Kyrle Paul A. , Quehenberger Peter , Mannhalter Christine , Lechner Klaus , Kaider Alexandra
Published: October 2002

There is strong evidence that the incidence of venous thromboembolism (VTE) is increased during pregnancy. However, it is unknown whether and to which extent pregnancy influences the risk for recurrent VTE in women with previous thrombosis. To investigate whether pregnancy temporarily increases the risk for recurrent thrombosis, we retrospectively evaluated the recurrence rate in 109 women who had at least one pregnancy after an episode of VTE by comparing the time period during pregnancy with the nonpregnant period. Forty-three women had a first recurrence during a total observation time of 1014 years. Eight events (73 observation years) occurred during pregnancy, and 35 events (941 observation years) occurred outside pregnancy. Recurrence rates per 100 patient-years were 10.9% during and 3.7% outside pregnancy. Relative risk during pregnancy was 3.5 (95% confidence interval, 1.6-7.8; P = .002). Our data suggest that pregnancy leads to a temporary increase in the risk for recurrent thrombotic events.