bluuebunny/crossref_metadata_2025 huggingface dataset:
Rotational energy relaxation of polar diatomic molecules diluted in simple liquids
Authors: Padilla A. , Pérez J. , Calvo Hernández A.
Published: October 2002

The rotational energy relaxation (T1 processes) of polar diatomic molecules diluted in nonpolar liquids is analyzed by means of a non-Markovian theory for the energy time autocorrelation function that does not require the usual population-coherence decoupling approximation. Non-Markovian rate equations are obtained in terms of two-time conditional probabilities and the involved transition rates are calculated in terms of quantum time correlation functions associated to the solute–solvent interaction. Alternative time scales for the discrete rotational levels have been introduced and compared with previous definitions. The usual long time, Markovian limit is recovered. The theory is applied to the study of the rotational energy relaxation of HCl in liquid SF6.
Interdiffusion in core-shell and quantum-dot-quantum-well nanocrystals
Authors: Stirner T.
Published: October 2002

Theoretical calculations, utilizing the effective-mass theory, are presented of exciton energies in semiconductor core-shell and quantum-dot-quantum-well nanocrystals. For core-shell nanocrystals, the influence of diffusion on the transition energies is investigated. It is shown that the diffusion-induced blue shift of the transition energy is a nonmonotonic function of the nanocrystal radius, and that the Coulomb interaction energy of the exciton is a strong function of the diffusion time. The calculations also show that the intersublevel energy spacing is a nonmonotonic function of the ground-state interband transition energy. For quantum-dot-quantum-well nanocrystals, both the exciton transition energy and the overlap integral between the electron and hole wave function is calculated. It is shown that quantum-dot-quantum-well nanocrystals can be designed such that the overlap integral either increases or decreases with increasing amounts of diffusion.
Band offsets and Schottky barrier heights of high dielectric constant oxides
Authors: Peacock P. W. , Robertson J.
Published: October 2002

Oxides with higher dielectric constants are required to act as gate dielectrics for future generations of electronic devices. The electronic structure and band offsets of the oxides on Si have been calculated for many candidate gate oxides using the local density formalism pseudopotential method. The predicted conduction band offsets are similar to those found earlier using the tight-binding method, and where available, with experimental values found by photoemission and internal photoemission. The oxides which are acceptable as gate oxides in terms of their band offsets are ZrO2, HfO2, La2O3, Y2O3, Al2O3, silicates such as ZrSiO4 and HfSiO4 and aluminates such as LaAlO3.
Background charge fluctuations and the transport properties of biopolymer-gold nanoparticle complexes
Authors: Berven C. A. , Wybourne M. N. , Clarke L. , Longstreth L. , Hutchison J. E. , Mooster J. L.
Published: October 2002

The room temperature electrical characteristics of biopolymer-gold nanoparticle complexes show threshold behavior, periodic conductance features, and current–voltage scaling that together indicate the nonlinear transport is associated with single electron charging. Repeated measurements over a period of up to 80 h showed the characteristics change with time. The current–voltage scaling behavior is found to be time independent, while the position of the conductance features shifted randomly over periods of many hours. We show that the time dependence is consistent with a fluctuating background charge distribution and can be understood within the framework of the orthodox model of single electron transport that is modified to account for the relatively large self-capacitance of the nanoparticles.
Theoretical investigation on the N+SF2→NS+ reaction involving resonance-enhanced multiphoton ionization process
Authors: Liu Ya-Jun , Huang Ming-Bao , Zhou Xiao-Guo , Li Quan-Xin , Yu Shu-Qin
Published: October 2002

NS + was detected from ionization of the final product of the N(2D)+SF2 reaction by laser multiphoton ionization. NS is not the spectral carrier of our REMPI (resonance-enhanced multiphoton ionization) spectrum. For understanding the experimental facts and to obtain a complete description of the whole process, quantum-chemical calculations were performed. The density functional theory/Becke’s three-parameter hybrid-function calculations indicate that NSF is the product of the most favorable channel of the N+SF2 reaction. The complete active space self-consistent field (CASSCF) potential energy curve calculations predict that 1 1A″ is a predissociative state of NSF with the NS radical and F atom as the dissociation products. The CASSCF vibrational frequencies calculated at the 1 1A″ minimum are in line with the excitation spectrum. The CASPT2 adiabatic excitation energy value of 3.32 eV for the 1 1A″ state is close to the energy value (3.44 eV) of one photon. On the basis of theoretical calculations, it is concluded that NS+ detected in the experiments is produced by one-photon dissociation and ionization of the 1 1A″ excited state of NSF, which is the product of the most favorable channel of the N+SF2 reaction.
Ab initio density functional investigation of the (001) surface of mordenite
Authors: Bucko T. , Benco L. , Demuth Th. , Hafner J.
Published: October 2002

Structural and acidic properties of the (001) surface of mordenite have been studied using density functional theory including generalized gradient corrections to the exchange-correlation functional. Our calculations, in agreement with experimental results, show that the surface structure of mordenite differs only moderately from the bulk structure, no reconstruction of the surface has been found. Part of the terminal silanol groups form weak hydrogen bonds with other framework oxygen sites, the lengths of hydrogen bonds vary in the range 1.9–2.6 Å depending on the position of the Al site. The OH-stretching frequencies for various acid sites in the mordenite framework have been calculated. In agreement with experiment, calculated OH-stretching frequencies of terminal silanol groups are shifted by about 100 cm−1 with respect to the Brønsted acid sites. Those silanol groups whose OH-stretching frequencies are modified by the presence of hydrogen bonds are shown to absorb in the region typical for the Brønsted acid sites.
Positronium trapping in small voids: Influence of their shape on positron annihilation results
Authors: Consolati G.
Published: October 2002

Positron annihilation lifetime spectroscopy is extensively used to get information on the sizes of the nanoholes existing in porous and nonmetallic solids. Cavities are most often modeled as spherical, although their shape is irregular. In the present paper the relationship between lifetime distribution as extracted from a time annihilation spectrum and size (and volume) distributions of the holes for some nonspherical geometries is discussed. It is shown that the same lifetime distribution can produce cavity size distributions having different momenta (centroid and standard deviation), if the shape of the hole is modified. Nevertheless, the ratio between the two momenta is largely independent of the geometry. Furthermore, parameters derived from the positron measurements (such as the free volume fraction) are not strongly influenced by the choice of the hole geometry.
Corrected Article: “The electronic influence of a third body on resonance energy transfer” [J. Chem. Phys. 116, 6701 (2002)]
Authors: Daniels Gareth J. , Andrews David L.
Published: October 2002

This investigation concerns an analysis of the effect, on the rate of resonance energy transfer between a pair of chromophores (the donor and acceptor), of a third chromophore species in their vicinity. Particularly when it is polar, the third body can exert an electrostatic influence on the energy-exchanging species that may result in a significant increase or decrease of their transfer rate. Furthermore it is shown how the presence of the third species can effectively “switch on” the energy transfer process, under circumstances where conventional energy transfer is forbidden due to orientational effects or on symmetry grounds. For example it is indicated that it is possible to instigate energy transfer when the salient acceptor or donor transitions are one-photon forbidden. In addition to results for structurally rigid systems, a rotationally averaged result applicable to fluids or disordered systems is presented.
On the acceptance probability of replica-exchange Monte Carlo trials
Authors: Kofke David A.
Published: October 2002

An analysis is presented of the average probability of accepting an exchange trial in the parallel-tempering Monte Carlo molecular simulation method. Arguments are given that this quantity should be related to the entropy difference between the phases, and results from simulations of a simple Lennard-Jones system are presented to support this argument qualitatively. Another analysis based on the energy distributions of a replica pair is presented, and an exact expression for the trial-move acceptance probability in terms of the overlap of these distributions is derived. A more detailed expression is presented using an approximation of constant heat capacity, and an asymptotic form for this result, good for large system sizes, is reported. The detailed analyses are in quantitative agreement with the simulation data. It is further shown that treatment of the energy distributions as Gaussians is an inappropriate way to analyze the acceptance probability.
Structural and electrical properties of homologous Srm−3Bi4TimO3m+3 (m=3, 4, 5, and 6) thin films
Authors: Zhang S. T. , Yang B. , Webb J. F. , Chen Y. F. , Liu Z. G. , Wang D. S. , Wang Y. , Ming N. B.
Published: October 2002

Polycrystalline thin films of Bi-layered Srm−3Bi4TimO3m+3 (referred to as BTO for m=3 and SBTim for m=4,5, and 6 respectively) were fabricated on Pt-coated silicon substrates by pulsed laser deposition. Structures were characterized by x-ray diffraction, atomic force microscopy, and scanning electron microscopy. Electric properties were investigated systematically. It was revealed that the remnant polarization Pr depended greatly on the parity of m. This dependence was well explained by using a rotating oxygen octahedra model along the a axis. The superior fatigue properties of SBTim (m=4,5,6) over BTO films were discussed in detail. The high dielectric constants and low dissipation factors of the films were demonstrated.
Double-exchange enhanced magnetoresistance in SrRu0.5Mn0.5O3
Authors: Sahu Ranjan K. , Manoharan S. Sundar
Published: October 2002

Magnetoresistance ratio (MR), Δρ/ρ0, in SrRu0.5Mn0.5O3 is enhanced by 20% near the Curie temperature (Tc=125 K) compared to the parent compound SrRuO3 (Tc=165 K) which is a super exchange mediated ferromagnetic metal. The enhancement in MR ratio in the equiatomic B site composition is due to the onset of double-exchange mediated ferromagnetic interaction. The Mn, Ru L2,3 edge of the x-ray absorption spectra of the SrRu0.5Mn0.5O3 phase shows the coexistence of ionic pairs involving Mn+3/Ru+5↔Mn+4/Ru+4. Mn+3 (t2g3eg1) recognizes both Mn+4/Ru+5 (t2g3eg0) as magnetically equivalent sites for eg electron hopping and for maintaining the eg hole carrier concentration.
Magnetic properties of copper metaborate CuB2O4
Authors: Petrakovskiı̌ G. A. , Pankrats A. I. , Popov M. A. , Balaev A. D. , Velikanov D. A. , Vorotynov A. M. , Sablina K. A. , Roessli B. , Schefer J. , Amato A. , Staub U. , Boehm M. , Ouladdiaf B.
Published: October 2002

The results of experimental research on the magnetic and resonance properties, heat capacity, muon spin relaxation, and neutron scattering of single-crystal copper metaborate CuB2O4 are reviewed. The results of a symmetry analysis and of modeling by the method of the phenomenological thermodynamic potential are presented. The magnetic structure of the crystal in various temperature intervals of the magnetic ordering region is discussed.
Atmospheric-pressure diffuse coplanar surface discharge for surface treatments
Authors: Šimor Marcel , Ráhel’ Jozef , Vojtek Pavel , Černák Mirko , Brablec Antonı́n
Published: October 2002

We report results from a plasma source; a diffuse coplanar surface discharge (DCSD), which is capable of generating macroscopically uniform thin layers of diffuse plasmas in air and other reactive gases at atmospheric pressure. DCSD is a type of dielectric barrier discharge generated on the surface of a dielectric barrier with embedded electrodes, which appears to be advantageous to surface treatment and deposition processes. Preliminary results on hydrophilization of polypropylene nonwoven fabric are also presented.
Social Housing Policy and the Welfare State: A Danish Perspective
Authors: Kristensen Hans
Published: October 2002

This paper focuses on the role of the social housing sector as part of Danish housing policy and on the role of housing policy in the Danish welfare state. The paper is mainly descriptive regarding social housing development in the post-war years, but in the last section of the paper some of the actual discussions on housing policy in Denmark are presented. One such theme is segregation, where it is argued that housing policy must become more integrated with social policy in order to cope with increased segregation. Another theme is the future division of responsibilities for housing policy between the state and the municipalities, where the argument is less state and more municipal involvement-and increasing diversity between the municipalities. Finally, the issue of sale of social housing is touched upon, but the expectation is that this will not become a big issue in Denmark, as social housing is regarded as an integral part of the Danish welfare state and, as such, nearly untouchable.
Contesting the Magic of the Market-place: Black Employment and Business Concentration in the Urban Context
Authors: Coleman G.
Published: October 2002

The spatial decentralisation of urban firms has been the primary focus of urbanists seeking to understand how Black employment is impacted by the changing nature of business in the US. Very little attention has been given to the impact of market concentration on Black employment in the urban environment. Using the most recent data available from the Equal Employment Opportunity Commission, the paper finds that Black male and female employment is positively associated with greater market concentration, not greater market competition as predicted by some neo-classical economists. There is little support for the contention that economic forces at work in competitive markets tend to minimise discrimination, either in the urban environment, or in the nation as a whole. The central city continues to be an important factor in Black employment because central-city firms are in industries with higher market concentration, which tend to employ more Black workers. However, increased market concentration is a crucial element in Black employment, regardless of industry location or worker occupation.
A Weird Politics of Place: Sergels Torg, Stockholm (Round One)
Authors: Franzen Mats
Published: October 2002

After World War II, central Stockholm was completely renewed; a new, modernist 'city' was designed, and a sunken plaza, Sergels torg, was laid out. Used by thousands daily, the square also became a centre for drug trafficking. Sergels torg fell into disrepute, which its periodic use for demonstrations and celebrations could not counteract. With a new local government in Stockholm in 1998, Sergels torg was unexpectedly set at the top of the agenda for a complete renewal in a most uncompromising way. Why this square, and in this way? An answer is sought in several steps, looking first at the square, its complex place history, the proposal's discursive construction and some of the forces behind it. Yet, a full explanation of this exceptional politics of place requires that attention also be given to the national scale.
Defying Disappearance: Cosmopolitan Public Spaces in Hong Kong
Authors: Law Lisa
Published: October 2002

This paper explores the relationship between public space and cultural politics in Hong Kong. There is a tendency to assert that public space is disappearing in the city, whether through overt control of the public sphere or the commodification of landscape. While similar views have been expressed in relation to many cities around the world, in Hong Kong these concerns are difficult to disentangle from post-colonial politics. This paper therefore situates anxieties about public space within an historical geography of the Central district. This contextual strategy is deployed to frame a contemporary case study of the imaged powerful and powerless in the city: Hong Kong Land, Central leading landlord and Filipino domestic workers who gather in Central on Sundays to enjoy their day off. It is suggested that this gathering and the political rallies it hosts disrupt normative understandings of public space by introducing a transnational element that helps us to see Hong Kong's public spaces as contested. The paper concludes by pointing to the possibilities opened up by conceiving the public space of Central as a cultural landscape and as a cosmopolitan space reflective of Hong Kong's possible futures.
Sera from patients with sepsis induce nitric oxide production in vascular smooth muscle cells
Authors: Fujita Hiroshi , Tomiyama Junji , Kudo Hideki , Morita Ikuo , Murota Sei-itsu
Published: October 2002

Background: Nitric oxide (NO) is an important physiological mediator of vascular tone and is involved in pathophysiology of septic shock. Although plasma nitrite is a stable end product of NO oxidation derived from endogenous NO, the plasma nitrite level is also easily affected by the intake of various foods, bacterial products and renal functional status.

Aims: We propose an excellent alternative assay technique for measuring endogenous NO production.

Methods: We measured the nitrite level in cultured vascular smooth muscle cells (SMC) treated with serum obtained from patients with sepsis (4 patients), by means of a chemiluminescence detector.

Results: The nitrite concentrations in such cells were significantly higher as compared to those in the cells treated with normal serum. Moreover, the increased nitrite levels in the SMC treated with the sera obtained from patients with sepsis were completely inhibited by L‐nitroarginine (1 mmol/L), a nitric oxide synthase inhibitor.

Conclusion: These data suggest that this assay method enable us to know the ability of endogenous NO production in each patient.
Safety Pharmacology Approaches
Authors: Hite Mark
Published: October 2002

This article presents views of a discipline termed safety pharmacology or general pharmacology. This is an area that provides information through empirical studies on new pharmacologic agents at doses above those thought to be efficacious and the no-toxicologic-effect level (NOEL) above which unwanted effects might occur. The usefulness of batteries of tests is discussed, and comments are made about the value of these in the drug developmental process.
Smoking addiction among university students in Istanbul
Authors: Onal A. Emel , Tumerdem Yildiz , Ozel Sevda
Published: October 2002

In this study, we investigated smoking addiction and some risk factors among university students in Istanbul. A questionnaire survey of 236 university students studying in Istanbul Medical Faculty (n: 148) and other faculties (n: 88) was performed with cross‐sectional and responding‐under‐observation methods in March‐May 1999. Thirty‐six per cent of the university students with mean age 24.0 (2.9 were addicted to smoking (n: 85): 41.3% males and 26.7% females; 67.5% were using imported and 32.5% were using local product cigarettes. Of the subjects, 18.1% were smoking 1‐10 cigarettes a day, 61.4% 11‐20 cigarettes a day and 20.5% more than 20 cigarettes a day. When alcohol and smoking addiction were compared with logistic regression analysis, with respect to gender, age, school, parents’ educational levels, living style and the sources of income, the risk factor for alcohol addicts was found to be more 2.54 times than smoking addicts (OR = 2.54, 95% CI = 1.38‐4.67; p = 0.003). The study has emphasized the association of alcohol and smoking addiction in university students and the prevalence of smoking addiction among adolescent females.
Effect of a dose of ethanol on acute tolerance and ethanol consumption in alcohol drinker(UChB) and non‐drinker (UChA) rats
Authors: Tampier Lutske , Quintanilla María Elena
Published: October 2002

Acute tolerance that develops within minutes of ethanol exposure appears to influence the apparent acute behavioral sensitivity of laboratory animals to ethanol actions. The existence of a correlation between voluntary ethanol consumption and the speed of acquiring acute tolerance has been proposed. In the present paper we investigated the effect of an acute dose of ethanol on tolerance development and on ethanol voluntary consumption in our two selected bred strains, UChA (low ethanol drinker) and UChB (high ethanol drinker) rats. Acute tolerance developed to motor impairment induced by a dose of ethanol of 2.3 g/kg. administered intraperitoneally was evaluated by the tilting plane test. Voluntary ethanol consumption was compared in rats receiving the ethanol dose, to rats receiving a saline intraperitoneal (i.p.) injection. The results show that UChB rats receiving an intoxicating dose of ethanol develop more tolerance and they significantly increased their ethanol consumption compared to the same line that received a saline injection, while no change in acute tolerance and voluntary ethanol consumption were obtained in UChA rats. In conclusion, a possible mechanism by which UChB rats drink high amounts of ethanol appears to be the development of tolerance to the pharmacological effects of ethanol.
Differential propensity to ethanol sensitization is not associated with altered binding to D1 receptors or dopamine transporters in mouse brain
Authors: Quadros Isabel M. H. , Nobrega José N. , Hipólide Débora C. , de Lucca Eliane M. , Souza‐Formigoni Maria L. O.
Published: October 2002

Behavioral sensitization to ethanol's stimulant effect has been proposed as a marker for individual abuse liability. In previous work we have demonstrated that mice showing an increased propensity to EtOH sensitization had higher levels of dopamine (DA) D2 receptor binding in localized brain areas compared to mice showing less sensitization. In the present study we examined whether altered binding to D1 or the DA transporter (DAT) might also be associated with differential propensity to develop EtOH sensitization. Male Swiss mice received 2.4 g/kg EtOH or saline intraperitoneally (i.p.) daily for 21 days, were tested weekly for locomotor activity, and then sacrificed. D1 and DAT binding were assessed by quantitative autoradiography using [3 H]SCH‐23390 and [3 H]WIN 35,428, respectively. EtOH‐treated mice were subdivided into sensitized and non‐sensitized subgroups according to their locomotor activity during treatment. Analyses of brain D1 (19 regions) and DAT (12 regions) binding densities revealed no significant differences among EtOH‐sensitized, ‐non‐sensitized or saline groups in any of the regions measured (all p values > 0.32 for D1 and > 0.16 for DAT). These results suggest that brain D1 and DAT binding, unlike the recently reported changes in D2 binding, do not differentiate mice that develop behavioral sensitization to ethanol from those that do not.
T‐wave response: a sensitive test for latent alcoholic polyneuropathy
Authors: Schott Klaus , Schäfer Gerd , Günthner Arthur , Bartels Mathias , Mann Karl
Published: October 2002

To date, the H‐reflex is the most sensitive test to measure nerve conduction velocity in alcoholic polyneuropathy. Analogous to the H‐reflex, we investigated the T‐wave response from the soleus muscle using a hand‐held reflex hammer. Twenty‐four inpatients suffering from chronic alcoholism and 24 healthy volunteers were recruited. All probands had a careful neurological examination and were graded (PNP‐classifications). The T‐ and H‐reflexes were measured. In the clinical examination, only a few patients exhibited symptoms of alcoholic PNP. However, when the autonomic nervous system was also tested, 50% exhibited signs of alcoholic PNP. Both the T‐ and H‐reflex responses were pathologically retarded, indicating latent alcoholic PNP in 60% of the patients. Thus the main finding in our study is the difference between clinical and electrophysiological examinations: only a few of the patients had neurological symptoms for alcoholic PNP but 14 patients (60%) exhibited a so‐called latent, subclinical alcoholic PNP by showing delayed reflex latencies. Measuring the T‐wave proved to be a simple and painless screening method for diagnosis and monitoring of alcoholic PNP. Among the clinical tests the best indicator for alcoholic PNP was the test for autonomous alcoholic PNP.
Serum naltrexone and 6‐beta‐naltrexol levels from naltrexone implants can block very large amounts of heroin: a report of two cases
Authors: Brewer Colin
Published: October 2002

The maximum dose of heroin that is blocked by customary doses of oral naltrexone (NTX) and its active metabolite 6‐beta‐naltrexol (6BNT) is unknown, particularly at trough serum levels which show much interindividual variation and can be low. NTX has only once been tested formally against opiate equivalents of more than 25 mg of diamorphine. Increasing interest in long‐acting implantable NTX preparations makes it important to have objective information about blocking activity at various blood levels of NTX and 6BNT. Two cases are described in which NTX and 6BNT levels as low as 2.8 and 9.0 ng/ml, respectively, were sufficient to block doses of pure diamorphine as high as 500 mg.
Bromocriptine use is associated with decreased smoking rates
Authors: Murphy M. F. G. , Hey K. , Johnstone E. , Munafo M. , Walton R. , Willis B. , Harrison P. J.
Published: October 2002

Dopaminergic transmission in the central nervous system is thought to underlie addictive behaviours, including smoking. One effective smoking cessation drug, bupropion, enhances dopaminergic transmission; conversely, antipsychotic drugs, which are dopamine antagonists, are associated with increased smoking. Thus we hypothesized that subfertile women treated with the potent dopamine agonist bromocriptine might smoke less as a consequence of their treatment. Among 4608 subfertile women those conceiving on bromocriptine were half as likely to smoke as those taking other drugs or those conceiving without medication (p < 0.0001). This observation supports the role of dopamine in nicotine addiction, and suggests that bromocriptine‐like drugs could be used effectively by pregnant women to aid cessation.
aP2 Protein Expression as a Diagnostic Marker in Soft Tissue Tumours
Authors: Yang T. T. , Reed A. C. C. , Athanasou N. A.
Published: October 2002

Purpose/Methods: The aP2 gene product (aP2 protein) is known to be expressed by preadipocytes and other immature fat
cells in vitro. A mouse monoclonal antibody raised against an 18 amino acid segment of the aP2 protein was found to react
with lipoblasts and fetal fat cells in paraffin sections of soft tissue tumours of adipose differentiation. In this immunohistochemical
study, we have further examined the diagnostic utility of aP2 expression in distinguishing tumours of adipose differentiation
from other benign and malignant soft tissue tumours.

Result and discussion aP2 was strongly expressed by lipoblasts in lipoblastomas and all types of liposarcoma as well as brown
fat cells in hibernomas. Optimal conditions for immunohistochemical identification of lipoblasts in tumours of adipose differentiation
was noted when the antibody was diluted 1:30 to 1:50. Small lipoblast‐like fat cells in pleomorphic lipoma and
spindle cell lipoma also showed variable staining for aP2 at this dilution of the antibody. Most benign and malignant soft
tissue tumours were distinguished by their absence of staining for aP2 protein, but some cases of myxoma, malignant fibrous
histiocytoma, synovial sarcoma and leiomyosarcoma contained tumour cells which reacted for aP2. aP2 protein expression
is likely to prove a useful means of distinguishing lipoblasts in liposarcoma but it should be used as part of a tumour panel
to exclude expression in other forms of mesenchymal tumour.
Malignant Fibrous Histiocytoma, Aggressive Fibromatosis and Benign Fibrous Tumors Express mRNA for the Metalloproteinase Inducer EMMPRIN and the Metalloproteinases MMP-2 and MT1-MMP
Authors: Åhlén Jan , Enberg Ulla , Larsson Catharina , Larsson Olle , Frisk Tony , Brosjö Otte , Rosen Anette von , Bäckdahl Martin
Published: October 2002

Purpose: Extracellular matrix metalloproteinase inducer (EMMPRIN) has been shown to stimulate fibroblasts to production
of matrix metalloproteinases (MMPs). MMPs comprise a family of proteolytic enzymes implicated in the degradation
of extracellular matrix which has been proposed to be one of the essential steps in tumor invasion and metastases. In the
present study we investigated the expression and location of mRNAs for EMMPRIN, matrix metalloproteinase‐2 (MMP-2),
and membrane‐type 1 matrix metalloproteinase (MT1-MMP) in mesenchymal tumors with different tendencies to recur or
metastasize.

Subjects: Eight malignant fibrous histiocytomas (MFH), seven aggressive fibromatosis (AF), and six benign fibrous tumors
(BF).

Method: The mRNA‐expression of EMMPRIN, MMP-2 and MT1-MMP were studied using mRNA in situ hybridization
technique.

Results: The mRNA‐expression of EMMPRIN, MMP-2 and MT1-MMP respectively were found at varying frequency and
level in all tumor types. The mRNAs corresponding to EMMPRIN and MMP-2 were seen in neoplastic cells as well as in
endothelial cells both inside and outside the tumor pseudo‐capsule, whereas MT1-MMP was seen only within the tumors.
The estimated mRNA levels of EMMPRIN and MMP-2 covariated significantly. Overall, the highest expression was found
in the MFH tumors and the lowest levels in the BF tumors.

Discussion: These findings suggest that the MMP‐inducer EMMPRIN and the extracellular matrix degrading system
involving the metalloproteinases MMP-2 and MT1-MMP is frequently activated in mesenchymal tumors. The covariation
between EMMPRIN and MMP-2 support previous findings that EMMPRIN may be an inducer of MMP‐2. The high
levels of MMP-2 mRNA in MFH indicate a relationship between the proteolytic activity of MMP-2 and the tumor aggressiveness.
Retroelement Distributions in the Human Genome: Variations Associated With Age and Proximity to Genes
Authors: Medstrand Patrik , van de Lagemaat Louie N. , Mager Dixie L.
Published: October 2002

Remnants of more than 3 million transposable elements, primarily retroelements, comprise nearly half of the human genome and have generated much speculation concerning their evolutionary significance. We have exploited the draft human genome sequence to examine the distributions of retroelements on a genome-wide scale. Here we show that genomic densities of 10 major classes of human retroelements are distributed differently with respect to surrounding GC content and also show that the oldest elements are preferentially found in regions of lower GC compared with their younger relatives. In addition, we determined whether retroelement densities with respect to genes could be accurately predicted based on surrounding GC content or if genes exert independent effects on the density distributions. This analysis revealed that all classes of long terminal repeat (LTR) retroelements and L1 elements, particularly those in the same orientation as the nearest gene, are significantly underrepresented within genes and older LTR elements are also underrepresented in regions within 5 kb of genes. Thus, LTR elements have been excluded from gene regions, likely because of their potential to affect gene transcription. In contrast, the density of Alu sequences in the proximity of genes is significantly greater than that predicted based on the surrounding GC content. Furthermore, we show that the previously described density shift of Alu repeats with age to domains of higher GC was markedly delayed on the Y chromosome, suggesting that recombination between chromosome pairs greatly facilitates genomic redistributions of retroelements. These findings suggest that retroelements can be removed from the genome, possibly through recombination resulting in re-creation of insert-free alleles. Such a process may provide an explanation for the shifting distributions of retroelements with time.
Determination of Minimum Number of Specimens in S-N Testing
Authors: Gope Prakash Chandra
Published: October 2002

A method for determination of minimum sample size required to estimate the fatigue life has been presented. No functional relationship between stress and fatigue life other than log normal and Weibull distribution function of fatigue life has been assumed. The method is based on the analysis of the variance of error which arises due to scattered nature of the fatigue life data. An example of the application of the presented method is also given.
Hydraulic Resistance and Permeability in Human Lumbar Vertebral Bodies
Authors: Ochia Ruth S. , Ching Randal P.
Published: October 2002

Hydraulic resistance (HR) was measured for ten intact human lumbar vertebrae to further understand the mechanisms of fluid flow through porous bone. Oil was forced through the vertebral bodies under various volumetric flow rates and the resultant pressure was measured. The pressure-flow relationship for each specimen was linear. Therefore, HR was constant with a mean of 2.22±1.45kPa*sec/ml. The mean permeability of the intact vertebral bodies was 4.90×10−10±4.45×10−10m2. These results indicate that this methodology is valid for whole bone samples and enables the exploration of the effects of HR on the creation of high-speed fractures.
Coupled dynamics of translation and collapse of acoustically driven microbubbles
Authors: Reddy Anil J. , Szeri Andrew J.
Published: October 2002

Pressure gradients drive the motion of microbubbles relative to liquids in which they are suspended. Examples include the hydrostatic pressure due to a gravitational field, and the pressure gradients in a sound field, useful for acoustic levitation. In this paper, the equations describing the coupled dynamics of radial oscillation and translation of a microbubble are given. The formulation is based on a recently derived expression for the hydrodynamic force on a bubble of changing size in an incompressible liquid [J. Magnaudet and D. Legendre, Phys. Fluids 10, 550–556 (1998)]. The complex interaction between radial and translation dynamics is best understood by examination of the added momentum associated with the liquid motion caused by the moving bubble. Translation is maximized when the bubble collapses violently. The new theory for coupled collapse and translation dynamics is compared to past experiments and to previous theories for decoupled translation dynamics. Special attention is paid to bubbles of relevance in biomedical applications.
Compilation of functional languages by program transformation
Authors: Fradet Pascal , Le Métayer Daniel
Published: October 2002

One of the most important issues concerning functional languages is the efficiency and the correctness of their implementation. We focus on sequential implementations for conventional von Neumann computers. The compilation process is described in terms of program transformations in the functional framework. The original functional expression is transformed into a functional term that can be seen as a traditional machine code. The two main steps are the compilation of the computation rule by the introduction of continuation functions and the compilation of the environment management using combinators. The advantage of this approach is that we do not have to introduce an abstract machine, which makes correctness proofs much simpler. As far as efficiency is concerned, this approach is promising since many optimizations can be described and formally justified in the functional framework.
An object-based programming model for shared data
Authors: Kaiser Gail E. , Hailpern Brent
Published: October 2002

The classical object model supports private data within objects and clean interfaces between objects, and by definition does not permit sharing of data among arbitrary objects. This is a problem for real-world applications, such as advanced financial services and integrated network management, where the same data logically belong to multiple objects and may be distributed over multiple nodes on the network. Rather than give up the advantages of encapsulated objects in modeling real-world entities, we propose a new object model that supports shared data in a distributed environment. The key is separating distribution of computation units from information-hiding concerns. Minimal units of data and control, called
facets
, may be shared among multiple
objects
and are grouped into
processes
. Thus, a single object, or information-hiding unit, may be distributed among multiple processes, or computation units. In other words, different facets of the same object may reside in different address spaces on different machines. We introduce our new object model, describe a motivating example from the financial domain, and then explain facets, objects, and processes, followed by timing and synchronization concerns.
Trace-based network proof systems
Authors: Widom Jennifer , Gries David , Schneider Fred B.
Published: October 2002

We consider incomplete trace-based network proof systems for safety properties, identifying extensions that are necessary and sufficient to achieve relative completeness. We investigate the expressiveness required of any trace logic to encode these extensions.
Efficient computation of interprocedural definition-use chains
Authors: Harrold Mary Jean , Soffa Mary Lou
Published: October 2002

The dependencies that exist among definitions and uses of variables in a program are required by many language-processing tools. This paper considers the computation of definition-use and use-definition chains that extend across procedure boundaries at call and return sites. Intraprocedural definition and use information is abstracted for each procedure and is used to construct an interprocedural flow graph. This intraprocedural data-flow information is then propagated throughout the program via the interprocedural flow graph to obtain sets of reaching definitions and/or reachable uses for reach interprocedural control point, including procedure entry, exit, call, and return. Interprocedural definition-use and/or use-definition chains are computed from this reaching information. The technique handles the interprocedural effects of the data flow caused by both reference parameters and global variables, while preserving the calling context of called procedures. Additionally, recursion, aliasing, and separate compilation are handled. The technique has been implemented using a Sun-4 Workstation and incorporated into an interprocedural data-flow tester. Results from experiments indicate the practicality of the technique, both in terms of the size of the interprocedural flow graph and the size of the data-flow sets.
Path analysis and the optimization of nonstrict functional languages
Authors: Bloss Adrienne
Published: October 2002

The functional programming style is increasingly popular in the research world, but functional languages still execute slowly relative to imperative languages. This is largely because the power and flexibility of functional languages restrict the amount of information readily available to the compiler, hindering its ability to generate good code. This article demonstrates that information aboutorder of evaluation of expressionscan be statically inferred for nonstrict functional programs and that optimizations based on this information can provide substantial speedups at runtime. We present an exact, nonstandard semantics calledpath semanticsthat models order of evaluation in a nonstrict, sequential functional language, and its computable abstraction,path analysis. We show how the information inferred by path analysis can be used to implement destructive aggregate updating, in which updates on functional aggregates that are provably not live are done destructively. We also demonstrate a new approach to strictness analysis and show that strictness analysis is subsumed by path analysis. Benchmarks are presented.
Debugging optimized code without being misled
Authors: Copperman Max
Published: October 2002

Correct optimization can change the behavior of an incorrect program; therefore at times it is necessary to debug optimized code. However, optimizing compilers produce code that impedes source-level debugging.

Optimization can cause an inconsistency between where the user expects a breakpoint to be located and the breakpoint's actual location. This article describes a mapping between statements and breakpoint locations that ameliorates this problem. The mapping enables debugger behavior on optimized code that approximates debugger behavior on unoptimized code sufficiently closely for the user to use traditional debugging strategies.

Optimization can also cause the value of a variable to be
noncurrent
—to differ from the value that would be predicted by a close reading of the source code. This article presents a method of determining when this has occurred, and shows how a debugger can describe the relevant effects of optimization. The determination method is more general than previously published methods; it handles global optimization and many flow graph transformations, and it is not tightly coupled to optimizations performed by a particular compiler. Necessary compiler support is also described.
TransformGen: automating the maintenance of structure-oriented environments
Authors: Garlan David , Krueger Charles W. , Lerner Barbara Staudt
Published: October 2002

A serious problem for programs that use persistent data is that information created and maintained by the program becomes invalid if the persistent types used in the program are modified in a new release. Unfortunately, there has been little systematic treatment of the problem; current approaches are manual, ad hoc, and time consuming both for programmers and users. In this article we present a new approach. Focusing on the special case of managing abstract syntax trees in structure-oriented environments, we show how automatic transformers can be generated in terms of an implementor's changes to the grammar of these environments.
Coordinating first-order multiparty interactions
Authors: Joung Yuh-Jzer , Smolka Scott A.
Published: October 2002

A
first-order multiparty interaction
is an abstraction mechanism that defines communication among a set of
formal process roles
. Actual processes participate in a first-order interaction by
enroling
into roles, and execution of the interaction can proceed when all roles are filled by distinct processes. As in CSP, enrolement statements can serve as guards in alternative commands. The
enrolement guard-scheduling problem
then is to enable the execution of first-order interactions through the judicious scheduling of roles to processes that are currently ready to execute enrolement guards.

We present a fully distributed and message-efficient algorithm for the enrolement guard-scheduling problem, the first such solution of which we are aware. We also describe several extensions of the algorithm, including:
generic roles; dynamically changing environments
, where processes can be created and destroyed at run time; and
nested-enrolement
, which allows interactions to be nested.
Lazy and incremental program generation
Authors: Heering J. , Klint P. , Rekers J.
Published: October 2002

Current program generators usually operate in a
greedy
manner in the sense that a program must be generated in its entirety before it can be used. If generation time is scarce, or if the input to the generator is subject to modification, it may be better to be more cautious and to generate only those parts of the program that are indispensable for processing the particular data at hand. We call this
lazy program generation
. Another, closely related strategy is
incremental program generation
. When its input is modified, an incremental generator will try to make a corresponding modification in its output rather than generate a completely new program. It may be advantageous to use a combination of both strategies in program generators that have to operate in a highly dynamic and/or interactive environment.
Polymorphic type inference and abstract data types
Authors: Läufer Konstantin , Odersky Martin
Published: October 2002

Many statically typed programming languages provide an abstract data type construct, such as the module in Modula-2. However, in most of these languages, implementations of abstract data types are not first-class values. Thus, they cannot be assigned to variables, passed as function parameters, or returned as function results. Several higher-order functional languages feature strong and static type systems, parametric polymorphism, algebraic data types, and explicit type variables. Most of them rely on Hindley-Milner type inference instead of requiring explicit type declarations for identifiers. Although some of these languages support abstract data types, it appears that none of them directly provides light-weight abstract data types whose implementations are first-class values. We show how to add significant expressive power to statically typed functional languages with explicit type variables by incorporating first-class abstract types as an extension of algebraic data types. Furthermore, we extend record types to allow abstract components. The components of such abstract records are selected using the dot notation. Following Mitchell and Plotkin, we formalize abstract types in terms of existentially quantified types. We give a syntactically sound and complete type inference algorithm and prove that our type system is semantically sound with respect to standard denotational semantics.
Two issues in parallel language design
Authors: Böhm A. P. W. , Oldehoeft R. R.
Published: October 2002

In this article, we discuss two programming language features that have value for expressibility and efficiency: nonstrictness and nondeterminism. Our work arose while assessing ways to enhance a currently successful language, SISAL [McGraw et al. 1985]. The questions of how best to include these features, if at all, has led not to conclusions but to an impetus to explore the answers in an objective way. We will retain strictness for efficiency reasons and explore the limits it may impose, and we will experiment with a carefully controlled form of nondeterminism to assess its expressive power.
A reexamination of “Optimization of array subscript range checks”
Authors: Chin Wei-Ngan , Goh Eak-Khoon
Published: October 2002

Jonathan Asuru proposed recently an enhanced method for optimizing array subscript range checks. The proposed method is however unsafe and may generate optimized programs whose behavior is different from the original program. Two main flaws in Asuru's method are described, together with suggested remedies and improvements.
Efficient fault-tolerant algorithms for distributed resource allocation
Authors: Choy Manhoi , Singh Ambuj K.
Published: October 2002

Solutions to resource allocation problems and other related synchronization problems in distributed systems are examined with respect to the measures ofresponse time, message complexity,andfailure locality. Response time measures the time it takes for an algorithm to respond to the requests of a process; message complexity measures the number of messages sent and received by a process; and failure locality characterizes the size of the network that is affected by the failure of a single process. An algorithm for the resource allocation problem that achieves a constant failure locality of four along with a quadratic response time and a quadratic message complexity is presented. Applications of the algorithm to other process synchronization problems in distributed systems are also demonstrated.