bluuebunny/crossref_metadata_2025 huggingface dataset:
Description and Validation of a Non-Invasive Technique to Measure the Posture of All Hand Segments
Authors: Vergara Margarita , Sancho-Bru Joaquı´n L. , Pe´rez-Gonza´lez Antonio
Published: January 2004

The aim of this work is to describe and validate a technique for measuring the posture of all the segments of the hand in a non-invasive way. The technique uses digital photographic images to reconstruct 3-D location of markers drawn on the skin. The markers are defined to obtain joint rotation angles with physiological meaning. Different experiments have been developed in order to analyze the accuracy and repeatability of the angle measurements. Although the placement of markers does not require any special care, the errors due to their location are lower than 2.6 deg in all cases, thus assuring the repeatability of the technique.
Effect of Specimen Thickness on Fracture Toughness of Bovine Patellar Cartilage
Authors: Adams D. J. , Brosche K. M. , Lewis J. L.
Published: January 2004

Fracture toughness and crack tip opening angle were measured for bovine patellar cartilage using modified single-edged notch specimens of two thicknesses. There was no difference in fracture toughness between thin (0.7 mm) versus relatively thick (2.7 mm) specimens, but the crack tip opening angle at initiation of crack propagation was larger for the thin specimens (106 deg) than for the thick specimens (70 deg). Fracture toughness of the bovine patellar cartilage 1.03kJ/m2 was not statistically different than that reported previously for canine patellar cartilage 1.07kJ/m2 employing the same methods. Large variation in measurements for both bovine and canine cartilage are in part attributable to variation between individual animals, and are consistent with variation in other mechanical property measurements for articular cartilage. The observed reduction in crack tip opening angle with increased specimen thickness is consistent with behavior of some engineering materials, and demonstrates that specimen thickness influences fracture behavior for bovine patellar cartilage.
In Vivo Activation of the p53 Pathway by Small-Molecule Antagonists of MDM2
Authors: Vassilev Lyubomir T. , Vu Binh T. , Graves Bradford , Carvajal Daisy , Podlaski Frank , Filipovic Zoran , Kong Norman , Kammlott Ursula , Lukacs Christine , Klein Christian , Fotouhi Nader , Liu Emily A.
Published: January 2004

MDM2 binds the p53 tumor suppressor protein with high affinity and negatively modulates its transcriptional activity and stability. Overexpression of MDM2, found in many human tumors, effectively impairs p53 function. Inhibition of MDM2-p53 interaction can stabilize p53 and may offer a novel strategy for cancer therapy. Here, we identify potent and selective small-molecule antagonists of MDM2 and confirm their mode of action through the crystal structures of complexes. These compounds bind MDM2 in the p53-binding pocket and activate the p53 pathway in cancer cells, leading to cell cycle arrest, apoptosis, and growth inhibition of human tumor xenografts in nude mice.
Learning from Lepidoptera
Authors: Wedell Nina
Published: January 2004

Butterflies
Ecology and Evolution Taking Flight. by Carol L. Boggs, Ward B. Watt, and Paul R. Ehrlich, Eds. University of Chicago Press, Chicago, 2003. 757 pp. $110, £77. ISBN 0-226-06317-8. Paper, $45, £31.50. ISBN 0-226-06318-6.

The volume, which grew out of an August 1998 symposium in Crested Butte, Colorado, provides a good overview of how butterflies can serve as model systems for understanding ecological and evolu-tionary patterns and processes.
Crustal recycling during subduction at the Eocene Cordilleran margin of North America: a petrogenetic study from the southwestern Yukon
Authors: Morris George A , Creaser Robert A
Published: January 2004

The early Eocene (57.355.4 Ma) Bennett Lake and Mount Skukum Volcanic Complexes lie on the Coast Plutonic Complex and Intermontane Belt boundary of the Canadian Cordillera at the British Columbia  Yukon border, some 200 km east of the current and Eocene continental margin. Both complexes contain rock types from basaltic andesite to rhyolite in a series of lava and pyroclastic flows. The location relative to the continental margin, the rock types, and the presence of an enhanced LILE/HFSE (large-ion lithophile / high field strength element) signatures in all samples imply that contemporaneous subduction was the controlling factor in the formation of these complexes. The majority of samples, however, return unusually low compatible element concentrations for given rock types. We interpret this data to show that partial melting of the crust was the major source of erupted magmas. One formation of andesites at Mount Skukum and one late dyke at Bennett Lake do show higher concentrations of compatible trace elements, suggesting the presence of primitive magmas in the crust at the time of eruption, which contaminated and were erupted with the crustal melts. SrNd isotopic data at both complexes are consistently primitive regardless of rock type and compatible element content, requiring a primitive crustal source for these magmas. We propose that the complexes were formed as a result of early Eocene subduction of the Kula Plate beneath the Canadian Cordillera. Intrusion of hot primitive melts caused partial melting of young crust to produce the majority of lavas observed. Contamination of these melts by primitive magmas is observed at both Mount Skukum and Bennett Lake.
Lake Terrell upland glacial resurgences and implications for late-glacial history, northwestern Washington State, U.S.A.
Authors: Kovanen Dori J , Slaymaker Olav
Published: January 2004

New geomorphic data from the Lake Terrell uplands along the western margin of the Fraser Lowland in Washington reveal moraines (and (or) a complex grounding zone) and raised marine terraces. A large ridge that almost encircles the upland is asymmetric, and its surface material consists of fine- to coarse-grained diamictons. These ridges are argued to have formed adjacent to an ice margin near the marine limit, where the depositional processes are variable (e.g., ice-rafted rainout, dumping, sediment gravity flow). Multiple crests and crosscutting relations suggest that at least two glacial resurgences occurred during deglaciation of this area. The presence of these features, and their probable extent and stratigraphic position, raise several questions about relative sea-level history and ice margin reconstructions for this area.
Tectonic setting of outer trench slope volcanism: pillow basalt and limestone in the Taconian orogen of eastern New York
Authors: Landing Ed , Pe-Piper Georgia , Kidd William SF , Azmy Karem
Published: January 2004

The only pillow basalt in synorogenic sedimentary rocks at the exterior margin of the Taconic orogen in eastern North America is at Stark's Knob in eastern New York. Earlier reported as extrusive into allochthonous Ordovician slope and rise facies, this small lens (ca. 125+ m long, 39 m thick) is a fault-bounded block in Upper Ordovician melange under the Taconian frontal thrust. Its N-MORB (normal mid-ocean ridge basalt) basalt geochemistry and spinel composition are characteristic of oceanic ridge settings at a water depth of 2 km or more. Abundant limestone lenses on pillows and lava shelves within pillows yielded a middle Late Ordovician gastropod. The limestones are reconciled with this extrusion depth and with limited early Paleozoic pelagic carbonate production by lime mud transport from the Laurentian platform or abiotic carbonate precipitation with sea-water heating during basalt extrusion. A genetic relationship between the parautochthonous Stark's Knob basalts and the allochthonous Jonestown volcanics in slope and rise facies of the Hamburg klippe, eastern Pennsylvania, is likely. Both are Ordovician MORB basalts that reflect volcanism on the subducting outer trench slope prior to the Taconic arc  Laurentia collision. Taconic orogenesis may have led to basalt production on the subducting plate by (1) the setting up of orogen-parallel, predominantly strike-slip motion on the subducting slab with MORB basalt generated at offsets in a setting analogous to the Gulf of California or (2) development of faults in a flexure-induced extensional regime. By either process, mafic volcanism appears to be a rare but tectonically significant process on outer trench slopes as continental margins or oceanic plates enter subduction zones.
ReOs and UPb geochronology of the Clear Creek, Dublin Gulch, and Mactung deposits, Tombstone Gold Belt, Yukon, Canada: absolute timing relationships between plutonism and mineralization
Authors: Selby David , Creaser Robert A , Heaman Larry M , Hart Craig JR
Published: January 2004

New ReOs molybdenite and UPb zircon dates from deposits of the Tombstone Gold Belt provide direct timing constraints for sulphide mineralization and crystallization of spatially associated plutons. At Clear Creek ReOs molybdenite dates (93.6 ± 0.3 to 92.4 ± 0.4 Ma) are in excellent agreement with the host intrusion UPb zircon age (92.3 ± 0.3 Ma). Consequently we propose the nominally younger existing 40Ar/39Ar hydrothermal mica ages (91.7 ± 0.4 and 90.0 ± 0.3 Ma) for Clear Creek are a result of slow cooling. At Dublin Gulch, the ReOs molybdenite date (93.2 ± 0.3 Ma) for a late stage vein is nominally younger than the host intrusion UPb zircon age (94.0 ± 0.3 Ma), in agreement with the deposits paragenesis. The UPb zircon date (92.1 ± 0.2 Ma) for the Mactung pluton, which lies adjacent to the W-skarn, has a younger age than the ReOs molybdenite dates (97.5 ± 0.5 Ma). Fluid inclusion geochemical data for ore-fluid indicate a magmatic origin for the W-skarn. However, the UPb and ReOs age data suggest that the exposed Mactung stock is not the source of ore-fluid for the W-skarn and that the progenitor pluton for ore-fluid is unknown. The robust age constraints obtained for mineralization and magmatism in this study are in accord with the hypothesis that these deposits are intrusion-related ore systems. The results are also in agreement with previous studies demonstrating that the ReOs molybdenite chronometer can provide accurate and precise dates for the timing of metallic mineralization with rigorous sampling protocol.
Investigation of thermochromism in a series of side-chain, liquid-crystalline, azobenzene-containing polymers
Authors: Freiberg Stephan , Lagugné-Labarthet François , Rochon Paul , Natansohn Almeria
Published: January 2004

The thermochromic properties of a series of liquid crystalline polymethacrylates, containing azobenzene side-chains with variable spacer lengths, were investigated. Annealing the amorphous polymer thin films above the glass transition temperature results in a rearrangement of the azobenzene moieties, causing a hypsochromic shift in the electronic absorption spectra. A detailed investigation of the spectral shift was performed by in situ UVvis spectroscopy and indicated the formation of H-type aggregates by the side-chain chromophores above the glass transition temperature. The rate at which the hypsochromic shift occurs is faster for polymers with shorter spacers since their high glass transition temperature results in a higher thermal energy during the thermochromic effect. Experimentally determined activation energies show that the aggregation occurs primarily due to side-chain relaxation (β-relaxation) and main-chain relaxation (α-relaxation). Further annealing above the isotropization temperature resulted in the onset of deaggregation and in most cases showed that the chromophores were freed from the ordered state.Key words: liquid-crystalline polymer, thermochromic properties, chain relaxation, aggregation, thin films, azobenzene mesogens.
Theoretical studies on the one- and two-photon absorption of tetrabenzoporphyrins and phthalocyanines
Authors: Zhou Xin , Ren Ai-Min , Feng Ji-Kang , Liu Xiao-Juan
Published: January 2004

The one-photon absorption (OPA) properties of tetrabenzoporphyrins (TBPs) and phthalocyanines (Pcs) were studied using the semiempirical ZINDO method and time-dependent density functional theory (TDDFT), respectively. The compared results confirmed that the semiempirical ZINDO method was reasonably reliable when calculating the OPA of tetrabenzoporphyrins and phthalocyanines. On the basis of the OPA properties obtained from the ZINDO method, two-photon absorption (TPA) properties of two series of molecules were investigated, using ZINDO and sum-over-states (SOS) methods. The results showed that the TPA cross-sections of all molecules were in the range of 220.6 × 1050  345.9 × 1050 cm4·s·photon1, which were in the same order of magnitude as the values reported in the literature. The relatively larger δ(ω) value for Pcs with respect to that for corresponding TBPs originates from larger intramolecular charge transfer, which can be characterized by the difference of dipole moment between S0 and S1 and the transition dipole moment between S1 and S5.Key words: two-photon absorption, ZINDO, sum-over-states, tetrabenzoporphyrin, phthalocyanines.
Partial and clear-cut harvesting of high-elevation sprucefir forests: implications for small mammal communities
Authors: Klenner Walt , Sullivan Thomas P
Published: January 2004

Subalpine spruce (Picea)  fir (Abies) forests occur throughout the Cordillera of western North America. A variety of alternative silvicultural systems to clear-cutting are being investigated in these high-elevation forests in terms of their impacts on ecosystem components. We tested the hypotheses that abundance, reproduction, and survival of populations of (i) southern red-backed voles (Clethrionomys gapperi Vigors) will decline, (ii) long-tailed voles (Microtus longicaudus Merriam) and northwestern chipmunks (Tamias amoenus J.A. Allen) will increase, and (iii) deer mice (Peromyscus maniculatus Wagner) will be similar, with respect to decreasing levels of tree retention. Small mammal populations were live-trapped from 1994 to 1998 in replicated sites of uncut forest, single tree selection, 0.1-ha patch cuts, 1.0-ha patch cuts, a 10.0-ha clearcut, and edges in an Engelmann spruce (Picea engelmannii Parry ex Engelm.)  subalpine fir (Abies lasiocarpa (Hook.) Nutt.) forest near Sicamous, British Columbia, Canada. Clethrion omys gapperi dominated the small mammal community, reaching a peak abundance of 80 animals/ha with mean values ranging from 31 to 50 animals/ha. Over the 4 postharvest years, abundance, reproduction, and survival of C. gapperi populations were consistently similar among uncut forest, single tree selection, and patch cut treatments compared with clear-cut sites where this species declined to extirpation. Microtus longicaudus and T. amoenus occurred predominantly in clearcut sites, whereas P. maniculatus was present in low numbers on all sites. With respect to small mammals, partial harvesting systems appear to provide a means for combining timber extraction with maintenance of mature forest habitat in these subalpine ecosystems.
Wound wood formation in Eucalyptus globulus and Eucalyptus nitens: anatomy and chemistry
Authors: Eyles Alieta , Davies Noel W , Mohammed Caroline
Published: January 2004

The wound-associated wood that developed 17 months following artificial xylem injury in Eucalyptus globulus (Labill) and Eucalyptus nitens (Maiden) was examined anatomically and chemically. This new tissue located immediately adjacent to the wound site and termed "wound wood" was highly variable consisting of callus, altered wood of increased parenchyma density, and dark extractives, visible to the naked eye. Subsequent chemical analysis of crude wound wood extracts by HPLC coupled to negative ion electrospray mass spectrometry revealed the presence of a diverse range of polyphenolic compounds including hydrolysable tannins, proanthocyanidins, flavanone glycosides, and formylated phloroglucinol compounds. A number of polyphenols were unequivocally identified including engelitin, pedunculagin, and tellimagrandin I. Other compounds present in wound wood include various hydroxystilbene glycosides and volatile terpenes. The importance of the diverse range of secondary metabolites detected in wound wood is discussed in relation to tree wound repair responses.
Crown rise due to competition drives biomass allocation in silver birch
Authors: Ilomäki Sakari , Nikinmaa Eero , Mäkelä Annikki
Published: January 2004

This study tests the hypothesis that the aboveground structure of silver birch (Betula pendula L.) is derivable from crown rise across a range of social positions of trees. Data were measured in 30-year-old birch monocultures of three different initial spacings. As suggested by the pipe model, there was a strong linear correlation between the total cross-sectional area of branches and that of stem at crown base. Foliage mass correlated with stem basal area at crown base. An allometric relationship was found between foliage mass and crown length, and the mean length (weighted by basal area) of branches correlated linearly with crown length. Pipe ratios of branches and foliage were found to be independent of slenderness (= tree height / breast height diameter). The proportion of stem in aboveground biomass increased from 80% to 96% when the slenderness index increased, the proportions of branches and leaves decreasing, respectively. For crown biomass, the proportion of foliage was greater in the more slender stems, accompanied with a corresponding decrease in the proportion of stems, while the share of branches remained rather constant. The ratio of productive (foliage) and nonproductive (stem plus branches) biomass inside the crown was positively correlated with slenderness, but in the whole tree, the ratio declined with increasing slenderness. The results of this study support the theory of functional balance and seem to be in conflict with the priority principle of allocation.
Monthly leaf area index estimates from point-in-time measurements and needle phenology for Pinus taeda
Authors: Sampson D A , Albaugh T J , Johnsen K H , Allen H L , Zarnoch S J
Published: January 2004

Leaf area index (LAI) of loblolly pine (Pinus taeda L.) trees of the southern United States varies almost twofold interannually; loblolly pine, essentially, carries two foliage cohorts at peak LAI (September) and one at minimum (MarchApril). Herein, we present an approach that may be site invariant to estimate monthly LAI for loblolly pine using point-in-time measurements from a LI-COR LAI-2000 plant canopy analyzer (PCA). Our analyses used needle accretion and abscission data from monthly needle counts and destructive harvest data from a replicated 2 × 2 factorial experiment of water and nutrition amendments. No significant treatment effects on relative needle accretion or abscission were observed. Cohort (interannual) differences in needle accretion were found but appeared trivial. Cohort year had variable effects on needle abscission. Abscission of current-year foliage began in July and continued through November of the third year; however, only 7%9% remained 23 months following bud initiation. A treatment-invariable regression of PCA measurements on cohort foliage biomass (r2 [Formula: see text] 0.98) was used to estimate annual cohort LAI. We derived monthly estimates of LAI from cohort accretion and abscission and cohort LAI. Monthly estimates of LAI for loblolly pine, using point-in-time measurements from the PCA, appear possible, although further testing is required.
A modelling approach to assess the long-term impact of beech bark disease in northern hardwood forest
Authors: Guerrier Catherine Le , Marceau Danielle J , Bouchard André , Brisson Jacques
Published: January 2004

This study proposes a modelling approach to assess the effect of beech bark disease on species demographic dynamics and structure of stands using SORTIE, a spatially explicit and individual-based forest succession model. The original model was modified to account for the increased mortality rate of infected Fagus grandifolia Ehrh. (American beech) and for some resistance to the disease. Two different scenarios, modeling species behaviour with and without the disease, respectively, were compared over a period of 300 years. Results reveal significant differences in species global demographic dynamics between both scenarios. Analyses of tree diameter-class distribution indicate that 50 years after the infestation, large F. grandifolia trees disappear, while the number of trees with a DBH between 11 and 50 cm considerably increases. At 300 years, the density of F. grandifolia with a DBH greater than 30 cm in the diseased scenario is superior or close to that in the nondiseased scenario, suggesting a progressive reestablishment of the species population structure. Eastern hemlock (Tsuga canadensis (L.) Carrière) is the species that largely benefits from beech bark disease. The study demonstrates the potential of a modelling approach to acquire quantitative insights about the long-term ecological impact of the disease.
Estimation of the physical wood properties of green Pinus taeda radial samples by near infrared spectroscopy
Authors: Schimleck L R , Mora C , Daniels R F
Published: January 2004

The application of near infrared (NIR) spectroscopy to the green wood of radial samples (simulated increment cores) and the development of calibrations for the prediction of wood properties are described. Twenty Pinus taeda L. (loblolly pine) radial strips were characterized in terms of air-dry density, microfibril angle (MFA), and stiffness. NIR spectra were obtained in 10-mm steps from the radial longitudinal and transverse faces of each sample and used to develop calibrations for each property. NIR spectra were collected when the wood was green (moisture content ranged from approximately 100% to 154%) and dried to approximately 7% moisture content. Relationships between measured and NIR estimates for green wood were good; coefficients of determination (R2) ranged from 0.79 (MFA) to 0.85 (air-dry density). Differences between calibrations developed using the radial longitudinal and transverse faces were small. Calibrations were tested on an independent set. Predictive errors were relatively large for some green samples and relationships were moderate; R2p ranged from 0.67 (MFA) to 0.81 (stiffness). Dry wood calibrations demonstrated strong predictive relationships with R2p ranging from 0.87 (air-dry density) to 0.95 (stiffness). NIR spectroscopy has the potential to predict the air-dry density, MFA, and stiffness of 10-mm sections of green P. taeda wood samples.
Rapid assessment of wood density of live trees using the Resistograph for selection in tree improvement programs
Authors: Isik Fikret , Li Bailian
Published: January 2004

Wood density is traditionally determined by a volumetric method that is accurate but expensive for large-scale sampling. A new device called the Resistograph was investigated for rapid assessment of relative wood density of live trees in progeny trials. Fourteen full-sib families of loblolly pine (Pinus taeda L.) produced by a six-parent half-diallel mating design were tested at four sites. For each family, wood density was measured with the traditional volumetric method and then compared with the Resistograph readings (amplitude). Amplitude had weak (0.29) to moderate (0.65) phenotypic correlations with wood density on an individual-tree basis over the four sites. The family mean correlation between the two measurements, however, was much stronger (0.92). The additive genetic correlation between the two measures was also high (0.95). Individual-tree breeding values of amplitude yielded more accurate rankings than phenotypic values. The rankings of the parental, general-combining abilities were identical for the two measures. Both wood density and amplitude were under strong genetic control at the family level (full-sib family heritability (h2fs) = 0.95 for wood density and h2fs = 0.85 for amplitude). The efficiency of using the Resistograph as a means of indirect selection for improvement of wood density was 87% at the family level. Results from this study suggest that the Resistograph could be used reliably and efficiently to assess relative wood density of live trees for selection in tree improvement programs. The method is rapid, nondestructive, and much cheaper than the traditional volumetric method.
Changes in root morphology after precommercial thinning in balsam fir stands
Authors: Ruel Jean-Claude , Larouche Catherine , Achim Alexis
Published: January 2004

Precommercial thinning is often used to control stand density in naturally regenerated balsam fir (Abies balsamea (L.) Mill.) stands. Early stand density control could have beneficial effects on longer term stand stability through a modification of stem shape and root development. To assess the effect of precommercial thinning, two thinned and two unthinned stands were selected. Root sections were collected at 25 cm from the centre of the stem for all major roots (diameter greater than 2 cm). A disk was also cut at breast height level. From these disks, response in radial growth was determined. Detailed root measurements were taken on the sample disks to assess treatment effect on the following variables: asymmetry in root cross-sectional area (CSA) distribution, individual root shape, as well as changes in root shape over time. A quick and pronounced response in root growth occurred. This response was greater than that observed in the trunk. No asymmetry in root CSA distribution was observed at the stand level. Trees allocated more to radial growth above the biological centre of the root both in treated and control stands, but this trend was increased by thinning. Roots also tended to develop T-beam shapes over time, both in control and thinned stands. Most roots initially did not possess an I-beam shape and did not develop one during the course of the study. According to our results, trees respond quickly to the new growing conditions created by thinning by increasing biomass allocation to parts of the roots where mechanical stresses are greater.
Chloroplast DNA variation ofTilia cordata(Tiliaceae)
Authors: Fineschi S , Salvini D , Taurchini D , Carnevale S , Vendramin G G
Published: January 2004

The distribution of haplotypic diversity of 17 Tilia cordata Mill. populations was investigated by PCRRFLP markers of the chloroplast genomes. A high number of haplotypes (14) and high total genetic diversity (hT= 0.881) were detected. The distribution of the chloroplast DNA haplotypes revealed low geographic structure of the genetic diversity; the coefficient of differentiation between populations, Gst= 0.552, was lower than the mean value reported for maternally inherited markers in Angiosperm tree species. The value of population subdivision for ordered alleles, as measured by Nst, was significantly higher than the value of population subdivision for unordered alleles (Nst= 0.662, Gst= 0.552), thus indicating the presence of a phylogeographic structure. The relatively low genetic differentiation among T. cordata populations may be explained mainly as a consequence of human impact on this species.
Estimates of genetic parameters for oleoresin and growth traits in juvenile loblolly pine
Authors: Roberds James H , Strom Brian L , Hain Fred P , Gwaze David P , McKeand Steven E , Lott Larry H
Published: January 2004

In southern pines of the United States, resistance to attack by southern pine beetle, Dendroctonus frontalis Zimmermann, is believed to principally involve flow of oleoresin to beetle attack sites. Both environmental and genetic factors are known to affect the quantity of oleoresin flow in loblolly pine, Pinus taeda L., but little is known about the genetic contribution to phenotypic variation in this trait. Here we report estimates of genetic variation in oleoresin flow and growth traits for a population of this species. Oleoresin yield, total height, and diameter were measured on 10- and 11-year-old trees from an experimental test in Santa Rosa County, Florida. Trees were from 72 full-sib families produced by mating 48 parents according to a disconnected partial diallel mating design. Resin yield was determined from breast-height samples collected at two times: once in the summer of 1999 when latewood was being produced (summer resin flow), and once in the spring of 2000 during earlywood formation (spring resin flow). All traits studied were found to be highly genetically variable and to have much greater additive than dominance variance. Estimates of narrow-sense heritability for spring and summer resin flow were in the moderate range and are comparable to values obtained for the growth traits. Additive genetic correlations between oleoresin yield and the growth traits were positive and moderately high, suggesting that directional selection to improve growth in loblolly pine will also result in increased production of oleoresin.
LEARNING RULES FOR ODOUR RECOGNITION IN AN ELECTRONIC NOSE
Authors: MCCOY STEPHEN A. , MARTIN TREVOR P. , BALDWIN JAMES F.
Published: January 2004

The problem of automating the sensing and classification of odours is one which promises a wide range of industrial applications. During the INTESA project, a prototype electronic nose was developed, using sensors based on novel conducting polymer materials and also more traditional MOS materials. The software component of the prototype processes the transient resistance change signals recorded by the hardware, and classifies the odour sample into one of a number of "odour classes". This paper describes two of the soft computing methods investigated for learning classification rules in this domain. The first method builds on previous work done on the Fril data browser, using clustering, fuzzy matching, Fril rules and evidential logic rules. The second method uses a fuzzy extension of the ID3 decision tree induction method, called "mass assignment tree induction (MATI)". Some of the results of applying these methods to data obtained from the INTESA prototype are presented and discussed.
SOME FORMULAE TO CALCULATE THE ENTROPIES OF THE IMAGE FUZZY SETS
Authors: HONG DUG HUN , KIM JANG HAN
Published: January 2004

In this paper, we introduce a simple new method on calculating the entropy of the image fuzzy set gotten by the extension principle without calculating its membership function.
DEFUZZIFICATION WITHIN A MULTICRITERIA DECISION MODEL
Authors: OPRICOVIC SERAFIM , TZENG GWO-HSHIUNG
Published: January 2004

In many cases, criterion values are crisp in nature, and their values are determined by economic instruments, mathematical models, and/or by engineering measurement. However, there are situations when the evaluation of alternatives must include the imprecision of established criteria, and the development of a fuzzy multicriteria decision model is necessary to deal with either "qualitative" (unquantifiable or linguistic) or incomplete information. The proposed fuzzy multicriteria decision model (FMCDM) consists of two phases: the CFCS phase - Converting the Fuzzy data into Crisp Scores, and the MCDM phase - MultiCriteria Decision Making. This model is applicable for defuzzification within the MCDM model with a mixed set of crisp and fuzzy criteria. A newly developed CFCS method is based on the procedure of determining the left and right scores by fuzzy min and fuzzy max, respectively, and the total score is determined as a weighted average according to the membership functions. The advantage of this defuzzification method is illustrated by some examples, comparing the results from three considered methods.
Nonsmooth optimal regulation and discontinuous stabilization
Authors: Bacciotti A. , Ceragioli F.
Published: January 2004

For affine control systems, we study the relationship between an optimal regulation problem on the infinite horizon and stabilizability. We are interested in the
case the value function of the optimal regulation problem is not smooth and feedback laws involved in stabilizability may be discontinuous.
L2(Σ)‐regularity of the boundary to boundary operator B∗L for hyperbolic and Petrowski PDEs
Authors: Lasiecka I. , Triggiani R.
Published: January 2004

This paper takes up and thoroughly analyzes a technical mathematical issue in PDE theory, while—as a by‐pass product—making a larger case. The technical issue is the L2(Σ)‐regularity of the boundary → boundary operator B∗L for (multidimensional) hyperbolic and Petrowski‐type mixed PDEs problems, where L is the boundary input → interior solution operator and B is the control operator from the boundary. Both positive and negative classes of
distinctive PDE illustrations are exhibited and proved. The larger case to be made is that hard analysis PDE energy methods are the tools of the trade—not soft analysis methods. This holds true not only to analyze B∗L, but also to establish three inter‐related cardinal results: optimal PDE regularity, exact controllability, and uniform stabilization. Thus, the paper takes a critical view on a spate of “abstract” results in “infinite‐dimensional systems theory,” generated by unnecessarily complicated and highly limited “soft” methods, with no apparent awareness of the high degree of restriction of the abstract assumptions made—far from necessary—as well as on how to verify them in the case of multidimensional dynamical systems such as PDEs.

The operator B*L for the wave equation with
Dirichlet controldx.doi.org/10.1155/S1085337504404011
The Apollonian metric: limits of the comparison and bilipschitzproperties
Authors: Hästö Peter A.
Published: January 2004

The Apollonian metric is a generalization of the hyperbolic metric. It is defined in arbitrary domains in ℝn. In this paper, we derive optimal comparison results between this metric and the jG metric in a large class of domains. These results allow us to prove that Euclidean bilipschitz mappings have small Apollonian bilipschitz constants in a domain G if and only if G is a ball or half‐space.
Multiscale deformation analysis by Cauchy‐Navier wavelets
Authors: Abeyratne M. K. , Freeden W. , Mayer C.
Published: January 2004

A geoscientifically relevant wavelet approach is established for
the classical (inner) displacement problem corresponding to a
regular surface (such as sphere, ellipsoid, and actual earth
surface). Basic tools are the limit and jump relations of
(linear) elastostatics. Scaling functions and wavelets are
formulated within the framework of the vectorial Cauchy‐Navier
equation. Based on appropriate numerical integration rules, a
pyramid scheme is developed providing fast wavelet transform
(FWT). Finally, multiscale deformation analysis is investigated
numerically for the case of a spherical boundary.
On the weak solutions of the forward problem in EEG
Authors: Troparevsky M. I. , Rubio D.
Published: January 2004

The process underlying the generation of the EEG signals can be
described as a set of current sources within the brain. The
potential distribution produced by these sources can be measured
on the scalp and inside the brain by means of an EEG recorder.
There is a well‐known mathematical model that relates the
electric potential in the head with the intracerebral sources. In
this work, we study and prove some properties of the solutions of
the model for known sources. In particular, we study the error in
the potential, introduced by considering an approximated shape of
the head.
Fetal Hypoxia Is Associated with Elevated Cord Serum C-Reactive Protein Levels in Diabetic Pregnancies
Authors: Loukovaara Mikko , Leinonen Pekka , Teramo Kari , Alfthan Henrik , Stenman Ulf-Håkan , Andersson Sture
Published: January 2004

Maternal diabetes increases the risk of intrauterine hypoxia. Inflammation may play a role in the pathogenesis of hypoxia-related neonatal complications. We studied correlations between levels of cord serum C-reactive protein (CRP), measured by a highly sensitive immunofluorometric assay, and indices of fetal hypoxia in diabetic pregnancies. Cord serum CRP correlated positively with amniotic fluid erythropoietin and umbilical artery pCO2. A negative correlation existed between cord serum CRP and umbilical artery pH and pO2. Amniotic fluid erythropoietin showed an independent effect on cord serum CRP in multiple regression analysis. These data suggest that the fetus responds to hypoxia by an inflammatory reaction.
Relationships of Serum Leptin Levels with Biochemical Markers of Bone Turnover and with Growth Factors in Normal Weight and Overweight Children
Authors: Bini Vittorio , Igli Baroncelli Giampiero , Papi Francesco , Celi Federica , Saggese Giuseppe , Falorni Adriano
Published: January 2004

Objective: To examine the hypothesis of an influence of leptin on growth factors and on biochemical markers of bone turnover of prepubertal overweight children. Design and Methods: 395 prepubertal children, 6–13 years of age, were selected and the relationships between circulating serum levels of leptin and insulin-like growth factor I (IGF-I), insulin growth factor binding protein-3 (IGFBP-3) and some biochemical markers of bone turnover (osteocalcin, OC; carboxyterminal propeptide of type I procollagen, PICP, and carboxyterminal propeptide of type I collagen, ICTP) were analyzed. The subjects were subdivided into normal weight (NW, n = 163) and weight excess (WE, n = 232) subjects. Results and Conclusions: Significant differences between the two groups were found for leptin (p < 0.01), IGF-I (p < 0.01) and IGFBP-3 (p < 0.01), with higher values in WEs, and for OC (p < 0.01) with higher values in NWs. A significant reduction of leptin (p < 0.01) and IGFBP-3 (p < 0.01) serum values and an increase of those of OC (p < 0.01) and PICP (p < 0.05), but not of ICTP, were registered in 103 WEs who showed a drop in weight excess during a weight-excess reduction program. No variations were observed in 26 non-responsive subjects. In a multivariate analysis in which leptin, corrected by BMI and sex, was the independent variable, a significant negative correlation was found with PICP (β = –0.235, p < 0.01), IGF-I (β = –0.180, p < 0.01) and height velocity (β = –0.155, p < 0.01). There was no correlation with OC, ICTP and IGFBP-3. The results demonstrate that nutritional status and leptin levels are involved in the regulation of growth factors and biochemical markers of bone formation.
Increased Endothelial Tetrahydrobiopterin Synthesis by Targeted Transgenic GTP-Cyclohydrolase I Overexpression Reduces Endothelial Dysfunction and Atherosclerosis in ApoE-Knockout Mice
Authors: Alp Nicholas J. , McAteer Martina A. , Khoo Jeffrey , Choudhury Robin P. , Channon Keith M.
Published: January 2004

Objective—

Increased production of reactive oxygen species and loss of endothelial nitric oxide (NO) bioactivity are key features of vascular disease states such as atherosclerosis. Tetrahydrobiopterin (BH4) is a required cofactor for NO synthesis by endothelial nitric oxide synthase (eNOS); pharmacologic studies suggest that reduced BH4 availability may be an important mediator of endothelial dysfunction in atherosclerosis. We aimed to investigate the importance of endothelial BH4 availability in atherosclerosis using a transgenic mouse model with endothelial-targeted overexpression of the rate-limiting enzyme in BH4 synthesis, GTP-cyclohydrolase I (GTPCH).

Methods and Results—

Transgenic mice were crossed into an ApoE knockout (ApoE-KO) background and fed a high-fat diet for 16 weeks. Compared with ApoE-KO controls, transgenic mice (ApoE-KO/GCH-Tg) had higher aortic BH4 levels, reduced endothelial superoxide production and eNOS uncoupling, increased cGMP levels, and preserved NO-mediated endothelium dependent vasorelaxations. Furthermore, aortic root atherosclerotic plaque was significantly reduced in ApoE-KO/GCH-Tg mice compared with ApoE-KO controls.

Conclusions—

These findings indicate that BH4 availability is a critical determinant of eNOS regulation in atherosclerosis and is a rational therapeutic target to restore NO-mediated endothelial function and reduce disease progression.
Adipophilin Enhances Lipid Accumulation and Prevents Lipid Efflux From THP-1 Macrophages
Authors: Larigauderie Guilhem , Furman Christophe , Jaye Michael , Lasselin Catherine , Copin Corinne , Fruchart Jean-Charles , Castro Graciela , Rouis Mustapha
Published: January 2004

Objective—

Uptake of modified low-density lipoprotein (LDL) by macrophages through scavenger receptors results in lipid droplets accumulation and foam cell formation. Excess lipid deposition in macrophages has been reported to modulate expression of several genes including adipophilin. In this study, we investigated the function of adipophilin in lipid accumulation and cholesterol efflux in THP-1 macrophages.

Methods and Results—

Adipophilin mRNA expression was 3.5-fold higher in human atherosclerotic plaques compared with healthy areas of the same arteries. Moreover, in the presence of acetylated LDL (AcLDL), triglycerides and cholesteryl esters were increased in macrophages overexpressing adipophilin by 40% and 67%, respectively, whereas their accumulation was reduced when endogenous cellular adipophilin was depleted using siRNA approach. In addition, neither overexpression nor downregulation of adipophilin altered expression of genes involved in lipid efflux. However, the affinity and the number of AcLDL receptors were not affected. After 24-hour incubation of lipid-loaded macrophages with apolipoprotein A-I, cholesterol efflux was reduced by 47% in adipophilin transfected cells versus control cells.

Conclusion—

Our results showed that stimulation of adipophilin expression in macrophages by modified LDL promotes triglycerides and cholesterol storage and reduces cholesterol efflux. Therefore, adipophilin might contribute, in vivo, to lipid accumulation in the intima of the arterial wall.
Covalently-Bound Heparin Makes Collagen Thromboresistant
Authors: Keuren Jeffrey F.W. , Wielders Simone J.H. , Driessen Anita , Verhoeven Michel , Hendriks Marc , Lindhout Theo
Published: January 2004

Objective—

Blood compatibility of artificial surfaces depends on their immunogenic and thrombogenic properties. Collagen’s weak antigenicity makes it an attractive candidate for stent coatings or fabrication of vascular grafts. However, the thrombogenic nature of collagen limits its application. We examined whether heparinization can make collagen more thromboresistant.

Methods and Results—

Collagen was heparinized by crosslinking collagen with extensively periodate oxidized heparin and/or by covalently bonding of mildly periodate oxidized heparin. Both ways of heparinization have no effect on platelet adhesion and could not abolish induction of platelet procoagulant activity. However, thrombin generation was completely prevented under static and flow conditions. The functionality of immobilized heparin was confirmed by specific uptake of antithrombin, 13.5±4.7 pmol/cm
2
and 1.95±0.21 pmol/cm
2
for mildly and heavily periodated heparin, respectively.

Conclusions—

These results indicate that immobilization of heparin on collagen, even as a crosslinker, is a very effective way to prevent surface thrombus formation. These data encourage the application of heparinized collagen as stent-graft material in animal and eventually human studies.
Effects of Carvedilol on Left Ventricular Remodeling After Acute Myocardial Infarction
Authors: Doughty Robert N. , Whalley Gillian A. , Walsh Helen A. , Gamble Greg D. , López-Sendón José , Sharpe Norman
Published: January 2004

Background—

The CAPRICORN trial has shown that carvedilol improved outcome in patients with left ventricular dysfunction after acute myocardial infarction treated with ACE inhibitors. The aim of this substudy was to determine the effects of carvedilol on left ventricular remodeling in this patient group.

Methods and Results—

Patients entering the CAPRICORN trial from 13 centers in New Zealand, Australia, and Spain were recruited for this echocardiographic substudy. In 127 patients, quantitative 2D echocardiography was performed according to a standard protocol before randomization and repeated after 1, 3, and 6 months of treatment with carvedilol or placebo. Left ventricular volumes, ejection fraction (Simpson’s method), and wall motion score index were determined in a blinded analysis at the Core Echo Laboratory. At 6 months, left ventricular end systolic volume was 9.2 mL less in the carvedilol group than in the placebo group (
P
=0.023), and left ventricular ejection fraction was 3.9% higher (
P
=0.015). Left ventricular end diastolic volume and wall motion score index were not statistically different between the 2 groups at 6 months.

Conclusions—

In patients with left ventricular dysfunction after acute myocardial infarction treated with ACE inhibitors, carvedilol had a beneficial effect on ventricular remodeling, which may, in part, mediate the substantial clinical beneficial effects of carvedilol in this patient population.
Canadian Trial of Physiological Pacing
Authors: Kerr Charles R. , Connolly Stuart J. , Abdollah Hoshiar , Roberts Robin S. , Gent Michael , Yusuf Salim , Gillis Anne M. , Tang Anthony S.L. , Talajic Mario , Klein George J. , Newman David M.
Published: January 2004

Background—

The Canadian Trial of Physiological Pacing (CTOPP) reported that the risk of stroke or cardiovascular death was similar between patients receiving ventricular versus physiological pacemakers at the end of the original follow-up period of 3 years. However, the occurrence of atrial fibrillation was significantly less frequent with physiological pacemakers. To assess a potential delayed benefit of physiological pacing, follow-up of patients in this study was extended to 6 years.

Methods and Results—

A total of 1474 patients requiring a pacemaker for symptomatic bradycardia were randomized to receive ventricular and 1094 to physiological pacemakers. The primary outcome was stroke or cardiovascular death. The study was completed in July 1998, and follow-up was extended to July 2001. At a mean follow-up of 6.4 years, there was no difference between treatment groups in the primary outcome of cardiovascular death or stroke. There was no significant difference in total mortality or stroke between groups. There was a significantly lower rate of development of atrial fibrillation in the physiological group, with a relative risk reduction of 20.1% (CI, 5.4 to 32.5;
P
=0.009).

Conclusions—

The CTOPP extended study does not show a difference in cardiovascular death or stroke, or in total mortality, or in stroke between patients implanted with ventricular or physiological pacemakers over a mean follow-up of >6 years. However, there is a persistent significant reduction in the development of atrial fibrillation with physiological pacing.