bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of target proximity on the aniso‐accommodative response
Authors: Marran Lynn , Schor Clifton M. 
Published: July 2002

SummaryAniso‐accommodation (unequal binocular accommodation) to lens‐induced anisometropia has been demonstrated by subjective and objective measurement techniques (Marran and Schor,Vision Res.38(22), 3601–3619). The gain of the response was significantly reduced for some subjects when aniso‐accommodation was stimulated by a target at 1 m compared to a target at 20 cm, even when the targets viewed were matched in retinal image size, convergence levels andaniso‐accommodative stimuli. The two conditions did differ in both the accommodative level and proximity of the target. Thus the higher gain of the response in the 20 cm condition could have arisen from either high proximity, high accommodative level or a combination of both.In this investigation, target proximity and accommodative level were manipulated independently while extra‐retinal cues such as absolute disparity and image size were held constant. The results show that high target proximity alone rather than accommodative level or a combination of the two was responsible for the distance dependent effect demonstrated by subjects. Furthermore, accommodative level did not affect the response when target proximity was held constant. Subjects who demonstrated invariant aniso‐accommodation with changes in viewing distance also demonstrated invariant aniso‐accommodation with experimental manipulation of target proximity at the target distances tested, as would be expected.These results suggest that high level processing, rather than a reflex blur response, is involved in aniso‐accommodation. This conclusion is strengthened by the previous finding of long reaction and response times, 11 and 15 s respectively, to step aniso‐accommodative stimuli (Marran and Schor,Vision Res.38(22), 3601–3619). Since the experimental target provided subjects with visual feedback of the relative blur of the dichoptically viewed letters, subjects had access to perceptual blur information cues. Some subjects seemed to have required both aniso‐blur and proximity to exercise this volitional response. Those subjects who showed a distance invariant aniso‐accommodative response may have been able to use perceived aniso‐blur alone and their ability to disregard proximal cues may have resulted from greater experience with the aniso‐accommodative stimuli. Alternatively, these subjects may have had a lower threshold to proximal stimuli and experienced target proximity at the more distant (1 m) viewing condition.
Microstructure of buried CoSi2 layers formed by high-dose Co implantation into (100) and (111) Si substrates
Authors: Bulle-Lieuwma C. W. T. , Van Ommen A. H. , Vandenhoudt D. E. W. , Ottenheim J. J. M. , de Jong A. F. 
Published: July 2002

Heteroepitaxial Si/CoSi2/Si structures have been synthesized by implanting 170-keV Co+ with doses in the range 1–3×1017 Co+ions/cm2 into (100) and (111) Si substrates and subsequent annealing. The microstructure of both the as-implanted and annealed structures is investigated in great detail by transmission electron microscopy, high-resolution electron microscopy, and x-ray diffraction. In the as-implanted samples, the Co is present as CoSi2 precipitates, occurring both in aligned (A-type) and twinned (B-type) orientation. For the highest dose, a continuous layer of stoichiometric CoSi2 is already formed during implantation. It is found that the formation of a connected layer, already during implantation, is crucial for the formation of a buried CoSi2 layer upon subsequent annealing. Particular attention is given to the coordination of the interfacial Co atoms at the Si/CoSi2 (111) interfaces of both types of precipitates. We find that the interfacial Co atoms at the A-type interfaces are fully sevenfold coordinated, whereas at the B-type interfaces they appear to be eightfold coordinated.
It is shown that these interface configurations introduce defects in the three-dimensional CoSi2 precipitates and Si matrix. As a result, the nuclei are subjected to compressive strain. It is argued that the combination of interface energy and strain results in a larger stability of small B-type nuclei as compared to A type. When the precipitates grow beyond a critical size of some 20–30 nm, A-type precipitates become more stable, finally resulting in a buried layer of aligned orientation if the layer thickness is larger than about 30 nm. If smaller, it is argued that upon prolonged annealing the layer will have a twinned orientation (B type). Annealed layers of aligned orientation in (100) Si are found to contain interfacial dislocations of edge type with Burgers vectors b=a/4〈111〉 and b=a/2〈100〉. These dislocations are associated with boundaries separating domains having different interface structures. For (111) Si, there exist edge-type dislocations with Burgers vector b=a/2〈110〉. The final state of strain can be attributed to the difference in thermal expansion between CoSi2 and Si. The strain at room temperature corresponds to a fully relaxed layer at about 700 °C. Below this temperature, dislocations become immobile.
Structural and electrical studies of radio frequency sputtered hydrogenated amorphous silicon carbide films
Authors: Choi W. K. , Loo F. L. , Ling C. H. , Loh F. C. , Tan K. L. 
Published: July 2002

The structural and electrical properties of radio frequency (rf) sputtered hydrogenated amorphous silicon carbide films are presented in this paper. Films were prepared with sputtering pressure Ps varied from 0.8 to 3 Pa, or with substrate temperature Ts varied from 100 to 300 °C. For films deposited with an argon plus hydrogen ambient, the deposition rate was found to increase with increase in Ps and decrease with an increase in Ts. For films prepared with an argon ambient only, the deposition rate increased slightly with an increase in Ps or Ts. The deposition rate was also approximately two to eight times higher when sputtering was carried out in an argon plus hydrogen ambient than in argon only. Infrared (IR), x-ray photoelectron (XPS), and Raman spectroscopies were employed in the structural analysis. The IR results showed that the Si–C bond gave the most prominent absorption peak and was affected by changes in Ps. The Si–H and SiHn stretching modes were observed in all films, and the amount of Si–H bonds NSi–H were found to increase as Ps or Ts was increased. The C–Hn stretching mode was absent in all films, and this was attributed to the low carbon content in these films.
The Si–N stretching mode was suggested to contribute to the extra features between 800 to 1100 cm−1 in the IR spectra for films prepared at a higher Ps (3 Pa) or Ts (300 °C). The stoichiometry of silicon carbide and the film composition were determined by the XPS method. The carbon content of silicon carbide was found to be similar to the target composition and varied only slightly with changes in Ps or Ts. The Raman spectra showed that only the C–C bond can be detected in all of the films. From the electrical measurements, the film’s conductivity was found to reduce from 4.21×10−9 to 4.35×10−11 Ω−1 cm−1 as Ps was increased from 0.8 to 3 Pa; and decreased from 3.81×10−9 to 1.31×10−8 Ω−1 cm−1 when Ts was raised from 150 to 300 °C. The conductivity was found to be related to NSi–H, with higher NSi–H resulting in lower conductivity. A comparison with data published in the literature suggested that rf sputtering technique was not effective in varying the carbon content in amorphous silicon carbide film. This technique, however, can be used to vary NSi–H and thus change the structural and electrical properties of the sputtered films.
An electronic mechanism for electron pairing in antiferromagnetic bridged mixed-valence systems
Authors: Ondrechen Mary Jo , Gozashti Saeed , Wu Xu Monica 
Published: July 2002

One- and two-dimensional bridged mixed-valence systems consisting of metal atoms M and polarizable ligands L are discussed. It is argued that when the valence state of the metal atom is changed, the energy gap and the effective resonance integral between M and L orbitals are also changed. The former is due to electron–electron repulsion and the latter to ligand polarization. A Hubbard model Hamiltonian with an occupation-dependent resonance integral is adopted to describe these systems. Approximate solutions are obtained by the Hartree–Fock method. One-dimensional chains and two-dimensional nets are studied, in which metal ions are joined together by bridging ligands. The fully oxidized system is taken to have one electron per metal orbital, with the ligand orbitals vacant. The electron spin vectors are aligned in an antiferromagnetic fashion. Upon the addition of extra electrons, low-lying vacancies can be formed under certain conditions, which can lead to interesting p-type conductive properties in one or two dimensions. In the one-dimensional system, the formation of such a low-lying vacancy requires that the regional orbitals which contain the added electron are delocalized over seven units or more. (If the bridging ligands are monatomic and the metal–ligand bond distance is about 2 Å, then the delocalization length is about 12 Å.)
This phenomenon is unlikely to be realizable in one dimension for the present type of system since it only occurs in parts of parameter space with an unrealistically small value for the electron–electron repulsion U. However, in two dimensions, low-lying vacancies are sometimes predicted by the present model for reasonable values for U. Furthermore, the minimum delocalization radius required for the generation of low-lying vacancies is somewhat smaller in two dimensions than in one. The relative stability of one isolated versus two paired excess electrons is also explored, although some crude assumptions about the delocalization lengths of two vs one excess electrons had to be made. When a single excess electron is delocalized over three units or more, the total energy for two paired excess electrons may be lower than that for two isolated excess electrons. Possible superconductivity by such an electronic mechanism is discussed.
Cohérence et vérité. Le rôle des modalisateurs épistémiques dans l'établissement de la vérité propositionnelle
Authors: Legros Denis , Baudet Serge 
Published: July 2002

Nous présentons, tout d'abord, les caractéristiques essentielles de notre modèle de vérité‐cohérence (Baudet, Jhean‐Larose, Legros, 1994) qui permet de définir la valeur de vérité associée à une assertion non pas simplement comme une connaissance sur le vrai de cette assertion, mais comme l'état final d'une activité cognitive qui participe au processus de référenciation.Nous présentons ensuite des résultats qui apportent des arguments à la thèse de la pertinence psychologique du concept de vérité. Ces résultats valident la première phase de notre modèle: la sélection d'un ensemble cohérent de candidat‐vrais à la vérité. Cette sélection est opérée grâce à l'attribution d'une valeur de plausibilité déterminée par des indices explicites de l'engagement de l'émetteur quant à la vérité des propositions contenues dans les phrases du texte.Selon ces résultats, les modalisateurs épistémiques du type “Je sais” et du type “Je crois”, engagent l'émetteur de façon différente quant à la vérité des propositions, ils déterminent des degrés de plausibilité et donc des rapports de cohérence différents entre les assertions et le modèle mental qui y réfère.Ces résultats valident donc l'hypothèse selon laquelle la fonction principale de l'opérateur d'énonciation du type “Je sais”, employé dans un texte, est d'informer le lecteur de l'engagement ferme du locuteur envers la valeur de vérité de la proposition, et donc de l'inviter à introduire la proposition p dans son domaine de connaissance, alors que la fonction de l'opérateur “Je crois” est d'indiquer les réserves du locuteur envers cette valeur de vérité.
Gender‐related symptoms and correlates of alcohol dependence among men and women with a lifetime diagnosis of alcohol use disorders
Authors: SANNIBALE CLAUDIA , HALL WAYNE 
Published: July 2002

AbstractThis study explored gender‐related symptoms and correlates of alcohol dependence in a cross‐sectional study of 150 men and 150 women with a lifetime diagnosis of alcohol use disorders (AUD). Participants were recruited in equal numbers from treatment settings, correctional centres and the general community. Standardized measures were used to determine participants' use of substances, history of psychiatric disorders and psychosocial stress, their sensation seeking and family history of substance use and mental health disorders. Multivariate analyses were used to detect patterns of variables associated with gender and the lifetime severity of AUD. Men had a longer history of severe AUD than women. Women had similar levels of alcohol dependence and medical and psychological sequelae as men, despite 6 fewer years of AUD. More women than men had a history of severe psychosocial stress, severe dependence on other substances and antecedent mental health problems, especially mood and anxiety disorders. There were differences in family history of alcohol‐related problems approximating same‐gender aggregation. The severity of a lifetime AUD was predicted by its earlier age at onset and the occurrence of other disorders, especially anxiety, among both men and women. The limitations in the generalizability of these findings due to sample idiosyncrasies are discussed.
Effect of heparin and related glycosaminoglycan on PDGF‐induced lung fibroblast proliferation, chemotactic response and matrix metalloproteinases activity
Authors: Sasaki Masahiro , Kashima Masayuki , Ito Takefumi , Watanabe Akiko , Sano Masaaki , Kagaya Manabu , Shioya Takanobu , Miura Mamoru 
Published: July 2002

Fibroblast migration, proliferation, extacellular matrix protein synthesis and degradation are the key events in various biological and pathological processes in pulmonary fibrosis. In addition, biopsy specimens from the lungs of patients with plumomary fibrosis show increased numbers of mast cells which have metachromatic granules containing heparin, histamin and proteases. Little is known about how these products influence pulmonary fibrosis. In the present study, we investigated the effect of heparin and related glycosaminoglycans on PDGF‐induced lung fibroblast proliferation and chemotactic response
in vitro. In addition, we examined the effect of heparin on both the induction of matorix metalloproteinases (MMPs) and MMPs activity in lung fibroblasts in vitro.Heparin, de‐N‐sulphated heparin but not heparan sulphate inhibited PDGF‐induced lung fibroblast proliferation. In contrast, only heparin inhibited PDGF‐stimulated human lung fibroblast chemotaxis. Negatively
charged poly‐L‐gultamic acid had no effect on either fibroblast proliferation or chemotaxis. Thus the negative charge alone cannot account for the ant‐proliferative and anti‐chemotactic effects of heparin.Furthermore, heparin and heparan sulphate also had no inhibitory effect on induction of MMPs, including MMP‐1 (interstitial collagenase), MMP‐2 (gelatinase A) and MMP‐9 (gelatinase B). Only heparin inhibited both MMP‐1 and MMP‐2/MMP‐9 activity. Additionally, tissue inhibitor of metalloproteinase type 1 (TIMP‐1) and type 2 (TIMP‐2) inhibited PDGF‐stimulated human lung fibroblast chemotaxis. The ability of heparin to inhibit fibroblast chemotaxis may account for the inhibitory effect of heparin on MMP activity.The above results suggested that heparin and related glycosaminoglycans differentially regulate PDGF‐induced lung fibroblast proliferation, chemotaxis and MMPs activity and further that these effects may have a key role in extracellular matrix remodeling in inflammatory lung disease.
Wealth and Power: Quesnay's Political Economy of the “Agricultural Kingdom”
Authors: Steiner Philippe 
Published: July 2002

The Physiocrats “New Science” of Political Economy is often represented as unrelated to the pursuit of national power. A recent study (Fourquet 1989), which rests on the approaches of Fernand Braudel (1979) and Immanuel Wallerstein (1980), has radicalized the thesis already propounded by Edmond Silberner (1939) who claimed that Quesnay was profoundly ignorant of military matters and failed to understand the power struggles being played out on the seas and in the colonies. Did not Quesnay propose turning back to an agricultural economy, banishing industry, trade, and the navy—in short, all the active forces thanks to which Great Britain had snatched domination of the world economy from Holland and thanks to which she would prevent France from obtaining it?Yet this thesis is weak. It must be remembered that Quesnay's first economic writings date from 1756–57, that is to say a period when confrontation between France and England was at a peak, with the start of the Seven Years' War. How could an author who claims to de ne the economic government ofan agricultural nation ignore the military problems which were so crucial in this period? Even if he wanted to, how could he succeed in doing so once he came to deal with taxes and the highly sensitive question of finance? How could he make himself understood by his contemporaries with a political theory that set aside all the burning issues of the day? How could he find an audience among those developing the science of commerce who always accorded great importance to the pursuit of power?Under scrutiny the traditional thesis appears inaccurate. After recalling the writings of some of his contemporaries, whom Quesnay knew and read (section 1), I shall show that articles drafted between 1756 and 1757, like published or unpublished works which Mirabeau and Quesnay elaborated between 1757 and 1760, give significant room to the nation's military power, particularly when the economic government is in question (section 2). From the years 1763–64 the idea of a natural order does not lead Quesnay to neglect the pursuit of power (section 3). These links between power and wealth in the work of the founder of Physiocracy will lead finally to some remarks on political economy as a form of rationalization of politics.
Functional Outcome in Sarcomas Treated With Limb‐Salvage Surgery or Amputation
Authors: Johansen Rikke , Nielsen Ole S. , Keller Johnny 
Published: July 2002

Purpose. In all patients treated at the Centre for Bone and Soft Tissue Sarcomas of Aarhus the functional outcome is prospectively evaluated by use of the Enneking system for the functional evaluation after surgical treatment of tumours of the musculoskeletal system. This system has been accepted by the Musculoskeletal Tumour Society and the International
Symposium on Limb Salvage.Patients/methods. In the present study the functional outcome after limb‐salvage surgery (89 patients) and amputation (58 patients) was compared. In the limb‐salvage group the treatment was surgery alone in 50% and surgery combined with either radiotherapy in 39% or chemotherapy in 11%. Inclusion criteria were: Deep seated extremity sarcomas, age >14 years, more than 1 year post‐treatment follow‐up time and alive at the end of the study. Median age was 49 years (range 14–88 years). Median tumour diameter was 8 cm (range 1–20 cm), median follow‐up time was 4.8 years (range 1–11 years). Wilcoxon and χ2‐tests were used for statistical analyses.Results. The two groups were comparable according to age, sex, size of tumour, type of tumour, location of tumour, as well as post‐treatment follow‐up time. The functional scores were significantly higher after limb‐salvage surgery as compared to amputation, the median scores being 85 and 47, respectively (p<0.001). A similar difference was observed
if the Enneking scores were subdivided into general health‐related scores and extremity‐related scores. No association was found between functional scores and the following factors by use of univariate analysis: size of tumour, radiation therapy, localization of tumour and surgical margin.Discussion. We conclude that this study indicates that limb‐salvage surgery is associated with a better functional outcome than that observed after amputation. However, whether this also indicates a difference in quality of life needs further studies.
Susceptibility of Fibromatosis Cells in Short‐Term Culture to Ifosfamide: A Possible Experimental Treatment in Clinically Aggressive Cases
Authors: Verrill Mark W. , Coley Helen M. , Judson Ian R. , Fisher Cyril 
Published: July 2002

Purpose. Deep fibromatoses are large, often rapidly growing
but benign soft tissue tumours. Although surgery is the mainstay of treatment, in
unremitting and aggressive cases the use of cytotoxic chemotherapy may produce
objective tumour responses. Fresh tumour samples from four patients with fibromatosis
were investigated as part of a study of drug resistance in soft tissue tumours.Methods. Following short‐term culture of fibromatosis cells in vitro ,
chemosensitivity to 4‐hydroperoxy‐ifosfamide, the active form of ifosfamide and
doxorubicin was tested. Following 72‐h continuous exposure to each drug,
surviving cell fraction was assessed using the lactate dehydrogenase assay.Results. Mean IC50
values for ifosfamide and doxorubicin were
6.2 and 0.35 µmol/l, respectively. In samples of soft tissue sarcoma (STS) from the
same study the mean IC50
values for ifosfamide and doxorubicin were 14.8 and
1.69 µmol. The difference in mean ifosfamide IC50
values for fibromatosis and
STS samples was statistically significant.Discussion. We are not aware of any other report suggesting
the use of ifosfamide in this condition. These observations suggest that, for patients
with inoperable or progressive lesions of fibromatosis causing significant morbidity,
it may be valuable to include ifosfamide in experimental treatment regimens.
Hyperthermic Isolated Limb Perfusion with TNF α and Cisplatin in theTreatment of Osteosarcoma of the Extremities: A Feasibility Study inHealthy Dogs
Authors: Van Ginkel Robert J. , Van Berlo Charles L. H. , Baas Peter C. , Koops Heimen Schraffordt , Stuling Ries Van Groningen B. , Elstrodt Jan , Hoekstra Harald J. 
Published: July 2002

Purpose. The feasibility of hyperthermic isolated limb perfusion
(HILP) with tumor necrosis factor‐α (TNFα ) and cisplatin for the management of
osteosarcoma was studied in the canine model.Methods. During seven perfusions in six healthy mongrel dogs
(weight 32±2 kg) technical aspects of HILP under mild hyperthermia (39– 40℃) were
studied. In five experiments HILP was performed with TNFα alone (0.5 mg/l extremity volume),
and in two experiments TNFα was combined with cisplatin (25 mg/l extremity volume).
During the perfusions physiological parameters were monitored and TNFα and total
cisplatin concentrations were determined.Results. Perfusion conditions (pH, PCO2
, PO2, flow and pressure)
remained within physiological ranges.Three dogs died within 24 h despite a sublethal
systemic concentration of TNFα that leaked from the perfusion circuit. Three dogs were
terminated; one dog after the second experiment in accordance with Dutch ethical rules;
one dog showed an invagination of the small bowel resulting in an ileus; one dog because
of necrosis of the perfused limb.Conclusions. This feasibility study in healthy dogs demonstrated that
HILP with TNFα and cisplatin was associated with a high mortality rate and does not allow
us to treat dogs with spontaneous osteosarcoma with TNFα and cisplatin HILP. Therefore,
an alternative model should be used in the search for the ideal combination of perfusion
agents for limb sparing treatment in human osteosarcoma.