julilili42/papers huggingface dataset:
Accelerated rendering in stereo-based projections (poster session)
2000-09-01

In this work, we present a new method for displaying stereo scenes, which speeds up the rendering time of complex geometry. We first discuss a scene splitting strategy, allowing us to partition objects to the distant background or the near foreground. Furthermore, wededuce a computation rule for positioning a cutting plane in the scene.
Application of on‐line C30 RP‐HPLC‐NMR for the analysis of flavonoids from leaf extract of Maytenus aquifolium
2000-09-01

The application of on-line C30-reversed-phase high-pressure liquid chromatography-nuclear magnetic resonance spectroscopy is described for the analysis of tetraglycosylated flavonoids in aqueous and hydroalcoholic extracts of the leaves of Maytenus aquifolium (Celastraceae). Triacontyl stationary phases showed adequate separation for on-line 1H-NMR measurements at 600 MHz and allowed the characterisation of these flavonoids by detection of both aromatic and anomeric proton signals. Copyright (C) 2000 John Wiley and Sons, Ltd.
Illumination and acceleration in the visualization of special relativity: a comment on fast rendering of relativistic objects
2000-09-01

We address the issue of illumination and acceleration in special relativistic visualization. Betts (J. Visual. Comput. Animat. 1998; 9: 17–31) presents an incorrect derivation of the transformation of the Rayleigh–Jeans radiation, which we compare to the correct transformation of radiance in the framework of special relativity. His rendering algorithm can be modified to correctly account for the relativistic effects on illumination. Furthermore, we show how acceleration can be included in special relativistic visualization by calculating the trajectory of accelerating objects, which is a prerequisite for a physically based camera model. Therefore interaction and animation in special relativistic visualization are possible. Copyright © 2000 John Wiley & Sons, Ltd.
Clinical and Therapeutic Profile of Patients Presenting With Acute Coronary Syndromes Who Do Not Have Significant Coronary Artery Disease
2000-09-05

Background —A proportion of patients who present with suspected acute coronary syndrome (ACS) are found to have insignificant coronary artery disease (CAD) during coronary angiography, but these patients have not been well characterized. Methods and Results —Of the 5767 patients with non–ST-segment elevation ACS who were enrolled in the Platelet Glycoprotein IIb/IIIa in Unstable Angina: Receptor Suppression Using Integrilin (Eptifibatide) Therapy (PURSUIT) trial and who underwent in-hospital angiography, 88% had significant CAD (any stenosis &gt;50%), 6% had mild CAD (any stenosis &gt;0% to ≤50%), and 6% had no CAD (no stenosis identified). The frequency of death or nonfatal myocardial infarction at 30 days was reduced with eptifibatide treatment in patients with significant CAD (18.3% versus 15.6% for placebo, P =0.006) but not in those with mild CAD (6.6% versus 5.4%, P =0.62) and with no CAD (3.0% versus 1.2%, P =0.28). We identified independent baseline predictors of insignificant CAD (mild or no CAD) and used them to develop a simple predictive nomogram of the probability of insignificant CAD for use at hospital presentation. This nomogram was validated in a separate population of patients with non–ST-segment elevation ACS. Conclusions —Patients with suspected ACS found to have insignificant CAD have a low risk of adverse outcomes, do not appear to benefit from treatment with eptifibatide, and can be predicted with a simple nomogram drawn from baseline characteristics. Because patients with significant CAD appear to have an enhanced benefit from eptifibatide treatment, the predictive nomogram developed can be used to determine indications for glycoprotein IIb/IIIa blockade.
Time and truth
2000-09-06

This paper is concerned with the “invisible hand” behind the polygenetic pathways of semantic change in grammaticalization. A comparison between Old English habban + Past Participle and Spanish tener + Past Participle brings to light specific discourse strategies which speakers use resultatives for. On the basis of this analysis, the paper re-examines the problem of explaining the shift from non-temporal to temporal meaning. It is argued that this shift is brought about by some very basic discourse strategies which are strong motives for repeated meaning change in the same direction.
Optimizing Multi-Feature Queries for Image Databases
2000-09-10

In digital libraries image retrieval queries can be based on the similarity of objects, using several feature attributes like shape, texture, color or text. Such multi-feature queries return a ranked result set instead of exact matches. Besides, the user wants to see only the k top-ranked objects. We present a new algorithm called Quick-Combine (European patent pending, nr. EP 00102651.7) for combining multi-feature result lists, guaranteeing the correct retrieval of the k top-ranked results. For score aggregation virtually any combining function can be used, including weighted queries. Compared to Fagin&amp;apos;s algorithm we have developed an improved termination condition in tuned combination with a heuristic control flow adopting itself narrowly to the particular score distribution. Top-ranked results can be computed and output incrementally. We show that we can dramatically improve performance, in particular for non-uniform score distributions. Benchmarks on practical ...
Oxidation and Oxygenation of Substituted Arenes with Alkyl Hydroperoxides or Dioxygen/Mediation by Schiff‐Base Complexes
2000-09-11

This chapter contains sections titled: Introduction Mechanistic Aspects Reactions with Dioxygen No Electron Transfer (NOET) Between Substrate and Metal Outer-Sphere Electron Transfer (OSET) Inner-Sphere Electron Transfer (ISET) Indirect Oxygenation (INDO) with t-BuOOH as Oxidant Oxygenation of Phenols and Thiophenols Regioselectivity in O2 Oxygenations Oxygenation of Tyrosine Derivatives Oxygenation of Thiophenols Mechanistic Implications Oxygenation of Anilines Oxygenation of Anilines with Metal Complexes and t-BuOOH (INDO) Oxygenation of Anilines with O2 Oxygenation of Melatonin Oxygenation with t-BuOOH Structure determination Oxygenation with O2 Structure determination Mechanistic Considerations Conclusions Summary References
ChemInform Abstract: Synthesis of Medium‐Sized Rings by the Ring‐Closing Metathesis Reaction
2000-09-12

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Neuroimaging of chronic pain: phantom limb and musculoskeletal pain
2000-09-13

New developments in brain imaging lead to a better understanding of cortical and subcortical processes involved in pain perception and the establishment of chronic pain. For different forms of chronic pain long-term changes in cortical structures have been described. In patients with phantom limb pain and back pain alterations in the somatotopic organization of the primary somatosensory (SI) could be observed. The amount of this reorganization is correlated with the subjective pain rating. These changes, which are based on processes of neuronal plasticity, can partially be reversed by analgesic interventions. For the investigation of cortical processes concerning reorganization, EEG and MEG methods are most suitable because of their high temporal and spatial resolution. In conclusion, these findings open a new way for therapeutic interventions to prevent the development of chronic pain.
Brain-Derived Neurotrophic Factor-Mediated Neuroprotection of Adult Rat Retinal Ganglion Cells In Vivo Does Not Exclusively Depend on Phosphatidyl-Inositol-3′-Kinase/Protein Kinase B Signaling
2000-09-15

The neurotrophin brain-derived neurotrophic factor (BDNF) serves as a survival, mitogenic, and differentiation factor in both the developing and adult CNS and PNS. In an attempt to identify the molecular mechanisms underlying BDNF neuroprotection, we studied activation of two potentially neuroprotective signal transduction pathways by BDNF in a CNS trauma model. Transection of the optic nerve (ON) in the adult rat induces secondary death of retinal ganglion cells (RGCs). Repeated intraocular injections of BDNF prevent the degeneration of RGCs 14 d after ON lesion most likely by inhibition of apoptosis. Here, we report that BDNF activates both protein kinase B (PKB) via a phosphatidyl-inositol-3'-kinase (PI-3-K)-dependent mechanism and the mitogen-activated protein kinases extracellular signal-regulated kinase 1 (ERK1) and ERK2. Furthermore, we provide evidence that BDNF suppresses cleavage and enzymatic activity of the neuronal cell death effector caspase-3. Distinct from our recent study in which inhibition of the PI-3-K/PKB pathway attenuated the survival-promoting action of insulin-like growth factor-I on axotomized RGCs (Kermer et al., 2000), it does not in the case of BDNF. Thus, we assume that BDNF does not depend on a single signal transduction pathway exerting its neuroprotective effects on lesioned CNS neurons.
Binary Desorption Isotherms of TCE and PCE from Silica Gel and Natural Solids
2000-09-15

Binary solute desorption isotherms of trichloroethylene (TCE) and tetrachloroethylene (PCE) at 100% relative humidity from silica gel and two well-characterized natural solids were investigated. Results indicated that the ideal adsorbed solution theory (IAST) was able to describe desorption isotherms for the silica gel. For the natural solids, IAST was not able to describe desorption isotherms for the full concentration range examined. Failure of lAST was greatest for the most heterogeneous sorbent, even when considering multiple sorption domains. In addition, IAST predictions worsened as nonlinear uptake mechanisms began to dominate. Several possible explanations for the failure of the IAST are given, including the possibility that complex interactions between the sorbing solutes and the sorbent may exist, causing deviations from ideal sorption behavior. Binary solute desorption isotherms of trichloroethylene (TCE) and tetrachloroethylene (PCE) at 100% relative humidity from silica gel and two well-characterized natural solids were investigated. Results indicated that the ideal adsorbed solution theory (IAST) was able to describe desorption isotherms for the silica gel. For the natural solids, IAST was not able to describe desorption isotherms for the full concentration range examined. Failure of IAST was greatest for the most heterogeneous sorbent, even when considering multiple sorption domains. In addition, IAST predictions worsened as nonlinear uptake mechanisms began to dominate. Several possible explanations for the failure of the IAST are given, including the possibility that complex interactions between the sorbing solutes and the sorbent may exist, causing deviations from ideal sorption behavior.
Mesoscopic normal-metal rings in a magnetic field
2000-09-15

Mesoscopic systems occupy a special place in the physical sciences: They lie somewhere between the microscopic and macroscopic worlds. Here we study persistent currents of normal-metal rings in a magnetic field and with a magnetic flux through the center of the ring. We discuss the effects of finite temperature and ensemble averaging. By these computations we are able to simulate experimental results for both single rings and arrays of rings.
Detection and Quantification of CD4+T Cells with Specificity for a New Major Histocompatibility Complex Class II-Restricted Influenza A Virus Matrix Protein Epitope in Peripheral Blood of Influenza Patients
2000-09-15

ABSTRACT FVFTLTVPS was identified as the core sequence of a new major histocompatibility complex class II-restricted T-cell epitope of influenza virus matrix protein. Epitope-specific CD4 + T cells were detected in the peripheral blood of patients with frequencies of up to 0.94%, depending on the number of additional terminal amino acids.
Influence of follicular dendritic cells on decay of HIV during antiretroviral therapy
2000-09-19

Drug treatment of HIV type 1 (HIV-1) infection leads to a rapid initial decay of plasma virus followed by a slower second phase of decay. To investigate the role of HIV-1 retained on follicular dendritic cells (FDCs) in this process, we have developed and analyzed a mathematical model for HIV-1 dynamics in lymphoid tissue (LT) that includes FDCs. Analysis of clinical data using this model indicates that decay of HIV-1 during therapy may be influenced by release of FDC-associated virus. The biphasic character of viral decay can be explained by reversible multivalent binding of HIV-1 to receptors on FDCs, indicating that the second phase of decay is not necessarily caused by long-lived or latently infected cells. Furthermore, viral clearance and death of short-lived productively infected cells may be faster than previously estimated. The model, with reasonable parameter values, is consistent with kinetic measurements of viral RNA in plasma, viral RNA on FDCs, productively infected cells in LT, and CD4 + T cells in LT during therapy.
ND3-density distribution in orientationally disordered Ni(ND3)6Cl2observed by means of neutron Laue diffraction
2000-09-19

Neutron Laue diffraction combined with the maximum-entropy method yields a powerful tool for direct observation of the density distribution of dynamically disordered molecules. Laue diffraction investigation delivers a systematically incomplete data set in a very much shorter time than using a conventional four-circle diffractometer, and the maximum-entropy method is an easy tool to use to cope with the gaps in the data set. From the calculated proton-density distribution the molecular hindering potential was successfully derived in the case of Ni(ND3)6Cl2.
Embedded Java
2000-09-20

The increasing complexity of embedded systems also results in a rapid growth of the software part, which tends to be developed in object oriented programming languages like C++ or Java. Originally planned for embedded systems, Java recently plays again a more important role in the context of embedded system from different points of views. Especially platform independence, multithreading parallelism, and internet embedding are important advantages and contribute to the increasing importance of Java in the following different aspects.At first, software reuse oriented concepts like Java Beans for the specification and prototyping of embedded systems have to be mentioned.Second, several standards have been developed to improve memory footprints as well as performance of Java for its use in embedded systems. Examples include PersonalJava, EmbeddedJava, JavaCard, Romizers, J2ME, and KVM.As a third more research oriented development we find Java more and more in the role of a modeling, specification, simulation, and synthesis language not only for the software but also for the hardware parts of embedded systems. This aspect is especially interesting for hardware/software co-design and co-simulation.In this talk, all these different aspects of Java, as well as their roles, contributions and impacts especially for embedded system design will be discussed.
[Current aspects of chemotherapy of metastatic pancreatic and biliary tract carcinomas].
2000-09-28

More than 50% of patients with pancreatic or biliary tract cancer are diagnosed in advanced and curatively unresectable tumor stages. To date, chemotherapeutic treatment yielded disappointing results in these patients with 5-year survival rates of 0-15%, leading to therapeutic nihilism in many patients. However, with the availability of new cytostatic agents as well as the introduction of the novel clinical endpoint "clinical benefit response" at least some improvements may be possible in patients with pancreatic cancer. Several randomized studies have shown a clinical and survival benefit for patients treated with chemotherapy as compared to patients treated with best supportive care alone. Gemcitabine was the first agent, which was investigated for its potential to improve symptoms as well as overall well being. A significant clinical benefit response can be achieved in up to 40% of patients with advanced pancreatic cancer. Gemcitabine is currently also investigated in combination chemotherapy regimens. First results with combination chemotherapy regimens such as cisplatin/gemcitabine have shown promising results. In addition, taxanes such as docetaxel also appear to have a certain activity in patients with pancreatic cancer. In contrast, topoisomerase I-inhibiting drugs seems to have no efficacy in the treatment of this disease. New and experimental therapeutic options such as angiogenesis-inhibition, matrixmetalloproteinase-inhibition or the use of monoclonal antibodies are currently evaluated within clinical studies. Only a few small studies reporting about chemotherapy in patients with biliary tract cancer have been published. This is mainly due to the rarity of this tumor entity, but also due to the rapid onset of symptoms such as hyperbilirubinemia, which will limit the number of potentially available drugs. 5-FU is the most widely investigated drug inducing remissions in 10-15% of patients. It is unclear whether new agents such as gemcitabine or the taxanes will led to an improvement of the prognosis of these patients. Although the recent advances in the treatment with these new therapeutic options are far from being satisfactory, it appears that a first small step ahead has been made the treatment of these diseases.
Effects of long–term spectral deprivation on the morphological organization of the outer retina of the blue acara ( Aequidens pulcher )
2000-09-29

To investigate the developmental plasticity of colour vision, we reared fish with a trichromatic cone system ( Aequidens pulcher ) under three near–monochromatic lights, differentially stimulating each spectral cone type from the larval stage to the age of at least one year. Control conditions comprised white lights of two intensities. The treatments did not affect the visual pigments, but led to significant changes in cone outer segment lengths. Furthermore, in the blue–reared group the density of single cones within the retina was reduced by two–thirds after 18 months of exposure, while no changes were observed in the other groups. The connectivity of cone horizontal cells with the single cones was influenced by the intensity and spectral composition of the rearing lights: H1 cells were more sensitive to the spectral component, whereas H2 cells responded to intensity cues. In the blue–light group the dynamics of horizontal cell synaptic spinule formation and degradation were severely compromised. These observations show that long–term spectral deprivation leads to significant morphological changes at the level of photoreceptors and horizontal cells. While the reactions of photoreceptors may be interpreted mostly in terms of compensation, the functional consequences of the changes observed on the horizontal cell level remain to be determined electrophysiologically.
Foveate vision in deep–sea teleosts: a comparison of primary visual and olfactory inputs
2000-09-29

The relative importance of vision in a foveate group of alepocephalid teleosts is examined in the context of a deep–sea habitat beyond the penetration limits of sunlight. The large eyes of Conocara spp. possess deep convexiclivate foveae lined with Müller cells comprising radial shafts of intermediate filaments and horizontal processes. Photoreceptor cell (171.8 × 10 3 rods mm −2 ) and retinal ganglion cell (11.9 × 10 3 cells mm −2 ) densities peak within the foveal clivus and the perifoveal slopes, respectively, with a centro–peripheral gradient between 3:1 (photoreceptors) and over 20:1 (ganglion cells). The marked increase in retinal sampling localized in temporal retina, coupled with a high summation ratio (13:1), suggest that foveal vision optimizes both spatial resolving power and sensitivity in the binocular frontal visual field. The elongated optic nerve head is comprised of over 500 optic papillae, which join at the embryonic fissure to form a thin nervous sheet behind the eye. The optic nerve is divided into two axonal bundles; one receiving input from the fovea (only unmyelinated axons) and the other from non–specialized retinal regions (25% of axons are myelinated), both of which appear to be separated as they reach the visual centres of the central nervous system. Comparison of the number of primary (first–order) axonal pathways for the visual (a total of 63.4 × 10 6 rod photoreceptors) and olfactory (a total of 15.24 × 10 5 olfactory nerve axons) inputs shows a marked visual bias (ratio of 41:1). Coupled with the relative size of the optic tecta (44.0 mm 3 ) and olfactory bulbs (0.9 mm 3 ), vision appears to play a major role in the survival of these deep–sea teleosts and emphasizes that ecological and behavioural strategies account for significant variation in sensory brain structure.
Fingerprinting taste buds: intermediate filaments and their implication for taste bud formation
2000-09-29

Intermediate filaments in taste organs of terrestrial (human and chick) as well as aquatic ( Xenopus laevis ) species were detected using immunohistochemistry and electron microscopy. During development, the potential importance of the interface between the taste bud primordium and non–gustatory, adjacent tissues is evidenced by the distinct immunoreactivity of a subpopulation of taste bud cells for cytokeratins and vimentin. In human foetuses, the selective molecular marker for taste bud primordia, cytokeratin 20, is not detectable prior to the ingrowth of nerve fibres into the epithelium, which supports the hypothesis that nerve fibres are necessary for initiating taste bud development. Another intermediate filament protein, vimentin, occurs in derivatives of mesoderm, but usually not in epithelium. In humans, vimentin immunoreactivity is expressed mainly in border (marginal) epithelial cells of taste bud primordia, while in chick, vimentin expression occurs in most taste bud cells, whereas non–gustatory epithelium is vimentin immunonegative. Our chick data suggest a relationship between the degree of vimentin expression and taste bud cell proliferation especially during the perihatching period. It is suggested that surrounding epithelial cells (human) and mesenchymal cells (chick) may be contributing sources of developing taste buds. The dense perinuclear network of intermediate filaments especially in dark (i.e. non–sensory) taste disc cells of Xenopus indicates that vimentin filaments also might be associated with cells of non–gustatory function. These results indicate that the mechanisms of taste bud differentiation from source tissues may differ among vertebrates of different taxa.