julilili42/papers huggingface dataset:
Sendai virus vectors as an emerging negative‐strand RNA viral vector system
2003-06-19

Abstract The power to manipulate the genome of negative‐strand RNA viruses, including the insertion of additional non‐viral genes, has led to the development of a new class of viral vectors for gene transfer approaches. The murine parainfluenza virus type I, or Sendai virus (SeV), has emerged as a prototype virus of this vector group, being employed in numerous in vitro as well as animal studies over the last few years. Extraordinary features of SeV are the remarkably brief contact time that is necessary for cellular uptake, a strong but adjustable expression of foreign genes, efficient infection in the respiratory tract despite a mucus layer, transduction of target cells being independent of the cell cycle, and an exclusively cytoplasmic replication cycle without any risk of chromosomal integration. In this review we describe the current knowledge of Sendai virus vector (SeVV) development as well as the results of first‐generation vector applications under both in vitro and in vivo conditions. So far, Sendai virus vectors have been identified to be a highly efficient transduction tool for a broad range of different tissues and applications. Future directions in vector design and development are discussed. Copyright © 2003 John Wiley &amp; Sons, Ltd.
Dynamics of a Bose–Einstein condensate in an anharmonic trap
2003-06-19

We present a theoretical model to describe the dynamics of Bose-Einstein\\ncondensates in anharmonic trapping potentials. To first approximation the\\ncenter-of-mass motion is separated from the internal condensate dynamics and\\nthe problem is reduced to the well known scaling solutions for the Thomas-Fermi\\nradii. We discuss the validity of this approach and analyze the model for an\\nanharmonic waveguide geometry which was recently realized in an experiment\\n\\\\cite{Ott2002c}.\\n
Effects of an adenosine A2A receptor blockade in the nucleus accumbens on locomotion, feeding, and prepulse inhibition in rats
2003-06-20

Abstract The nucleus accumbens (NAc) subserves behaviors governed by natural rewards, i.e., feeding or exploration, and has been implicated in control of prepulse inhibition (PPI), a measure of sensorimotor gating. The present study sought to determine whether a tonic stimulation of adenosine A 2A receptors in the rat NAc is involved in control of spontaneous locomotor activity, feeding behavior, and PPI. To this end, bilateral microinfusions of a prodrug (MSX‐3) (3 μg and 5 μg in 1 μl per side) of the selective A 2A receptor antagonist MSX‐2 or vehicle (1 μl per side) were administered into the NAc. Results show that blockade of intra‐NAc adenosine A 2A receptors by a high (5 μg), but not by a low (3 μg), dose of MSX‐3 increased locomotor activity in an open field, reduced food intake, and delayed intake onset in food‐deprived rats examined in a test cage with standard laboratory chow. Furthermore, PPI was significantly disrupted after intra‐NAc infusion of 5 μg, but not 3 μg, MSX‐3. These findings suggest that locomotor activity as well as intact PPI and feeding behavior rely on tonic activation of intra‐NAc A 2A receptors. The data add further support to the view that adenosine is a tonically active modulator of striatal function through actions on A 2A receptors. Synapse 49:279–286, 2003. © 2003 Wiley‐Liss, Inc.
Preparation of curved root canals with rotary FlexMaster instruments compared to Lightspeed instruments and NiTi hand files
2003-06-20

Abstract Aim To compare the recently introduced rotary FlexMaster instruments with Lightspeed instruments and NiTi hand files in preparing curved root canals. Methodology Root canals of extracted molars were shaped with rotary FlexMaster instruments (‘FM’: n = 45), Lightspeed instruments (‘LS’: n = 46), and NiTi hand files ( n = 45) using the balanced‐force technique. The apical preparation size was 40. Root canal instrumentation was carried out in a phantom head under clinical conditions. A re‐assembly technique allowed a comparison of the canal outline before and after preparation. Root sections 2.5 mm short of working length were used to calculate the percentage of prepared canal outline (= PPO) and the amount of root canal transportation. Loss of working length, fracture rate and time spent on complete preparation were also recorded. Results The highest PPO values were found in the LS group (mean = 63% [95% CI: 55%; 70%]). Although not statistically significant, lower PPO values were detected for FM instruments (mean = 55% [95% CI: 49%; 62%]) and for hand files (mean = 53% [95% CI: 47%; 59%]). The incidence of root canal transportation exceeding 0.1 mm was significantly lower in the LS group than in the FM group. Loss of working length of 0.5 mm occurred in five cases (LS group: 4×; FM group: 1×). Two LS instruments fractured. Half the time was needed for root canal preparation with FM instruments than with hand files. Conclusions Rotary FM instruments are suitable for preparing curved root canals. They provided results similar to LS instruments with minimal risk of instrument fracture but increased risk of root canal transportation.
Vortex critical behavior at the deconfinement phase transition
2003-06-20

The de-confinement phase transition in SU(2) Yang-Mills theory is revisited\\nin the vortex picture. Defining the world sheets of the confining vortices by\\nmaximal center projection, the percolation properties of the vortex lines in\\nthe hypercube consisting of the time axis and two spatial axis are studied.\\nUsing the percolation cumulant, the temperature for the percolation transition\\nis seen to be in good agreement with the critical temperature of the thermal\\ntransition. The finite size scaling function for the cumulant is obtained. The\\ncritical index of the finite size scaling function is consistent with the index\\nof the 3D Ising model.\\n
Evolutionary transformations of myoseptal tendons in gnathostomes
2003-06-22

Axial undulations in fishes are powered by a series of three-dimensionally folded myomeres separated by sheets of connective tissue, the myosepta. Myosepta have been hypothesized to function as transmitters of muscular forces to axial structures during swimming, but the difficulty of studying these delicate complex structures has precluded a more complete understanding of myoseptal mechanics. We have developed a new combination of techniques for visualizing the three-dimensional morphology of myosepta, and here we present their collagen-fibre architecture based on examination of 62 species representing all of the major clades of notochordates. In all gnathostome fishes, each myoseptum bears a set of six specifically arranged tendons. Because these tendons are not present outside the gnathostomes (i.e. they are absent from lampreys, hagfishes and lancelets), they represent evolutionary novelties of the gnathostome ancestor. This arrangement has remained unchanged throughout 400 Myr of gnathostome evolution, changing only on the transition to land. The high uniformity of myoseptal architecture in gnathostome fishes indicates functional significance and may be a key to understanding general principles of fish swimming mechanics. In the design of future experiments or biomechanical models, myosepta have to be regarded as tendons that can distribute forces in specific directions.
Novel Substituted Pyridinyl Imidazoles as Potent Anticytokine Agents with Low Activity against Hepatic Cytochrome P450 Enzymes
2003-06-24

A series of polysubstituted pyridin-4-yl imidazole inhibitors of p38 MAP (mitogen-activated protein) kinase was prepared as small molecular anticytokine agents and drug candidates for the treatment of chronic inflammatory diseases. The contribution of substituents at the pyridinyl and imidazole moiety to selective inhibition of p38 without concomitant cytochrome P450 interaction was evaluated. Placement of a 1-phenylethyl (7e, p38: IC(50) 0.38 microM) or acetyl substituent at the exocyclic nitrogen of several 2-aminopyridine imidazoles led to the identification of potent p38 inhibitors which exceeded the starting lead ML 3375 (p38: IC(50) 0.63 microM) in potency. A preliminary modeling study related the enhanced bioactivity of 7e to a novel interaction between its 1-phenylethylamino side chain and a hydrophobic pocket close to the linker region of p38. The most active p38 inhibitors in this series maintained their efficacy in functional PBMC (peripheral blood mononuclear cells) and whole blood assays. Moreover, cytochrome P450 interaction, which has been linked to the liver toxicity observed for model p38 inhibitors, was very efficiently reduced through introduction of a tetramethylpiperidine substituent at the 1 position of the imidazole nucleus. Combination of both structural features provided 14c (p38: 0.34 microM, inhibition of CYP1A2 0%, 2C9 2.6%, 2C19 7.6% at 10 microM), which was selected for further development.
Assessing the role of anal intercourse in the epidemiology of AIDS in Africa
2003-06-24

Public health authorities have long believed that the preponderance of AIDS cases in Africa are attributable to 'heterosexual transmission'; most people silently assume this rubric to indicate penile–vaginal intercourse only. Recent epidemiologic analyses suggest that the majority of HIV cases in sub-Saharan Africa may be due to non-sterile health care practices. The present paper reviews the anthropological, proctologic, and infectious disease literature, and argues that both homosexuality and heterosexual anal intercourse are more prevalent in Africa than has traditionally been believed. The authors hypothesize that perhaps the majority of HIV transmission not accounted for by iatrogenic exposure could be accounted for by unsuspected and unreported penile–anal intercourse. Given the authors' findings, properly conducted studies to measure this HIV transmission vector, while controlling for iatrogenic exposure confound, are clearly warranted in Africa and in countries with similar epidemiologic characteristics.
Cresyl Violet as a Fluorophore in Confocal Laser Scanning Microscopy for Future In-Vivo Histopathology
2003-06-24

Cresyl violet is a clinically usable fluorophore for confocal laser scanning microscopy. Its use in combination with an endoluminally applicable system has the potential to allow in vivo histopathology.
Characterization of Daunorubicin-Induced Apoptosis in Retinal Pigment Epithelial Cells: Modulation by CD95L
2003-06-24

Apoptosis has been shown to be an important factor in the control of specific cell populations. The synergistic activity of an antiproliferative agent, daunorubicin, and a cytokine, CD95L, induces apoptosis in RPE cells. Such approaches provide a means to reduce the concentration of chemotherapeutic agents with a small therapeutic window owing to retinal toxicity, such as daunorubicin, in the adjuvant therapy of proliferative vitreoretinopathy.
Do CTG expansions at the SCA8 locus cause ataxia?
2003-06-25

Abstract To evaluate the significance of expanded CTG repeats at the SCA8 locus, we analyzed the allele distribution in 1,262 German ataxia patients. We found intermediate and expanded CTG repeats with similar frequencies in ataxia patients with and without established genetic diseases. One family linked to the SCA8 locus showed incomplete penetrance and an association of smaller CTG repeats with more severe disease. Our data question the disease‐causing character of CTG expansions for SCA8 and advise great caution in genetic testing. Ann Neurol 2003;54:110–115
Progress in collision detection and response techniques for cloth animation
2003-06-25

In the animation of deformable objects, collision detection and response are crucial for performance. Furthermore, a physically correct cloth simulation requires robust collision avoidance, since any overlapping is visible and often results in expensive correction procedures. Much progress has been achieved in improving the numerical solution, and therefore most animations employ large time steps for fast simulations. This even more demands for accurate collision detection and response. In this work we show how collision detection for deformable meshes can be extended to detect proximities in advance. Several heuristics are introduced to save computation time, and constraints ensure an accurate collision response.
A smart single-chip micro-hotplate-based chemical sensor system in CMOS-technology
2003-06-25

A novel monolithic chemical (gas) sensor fabricated in industrial CMOS-technology combined with post-CMOS micromachining is presented, which comprises metal-oxide (SnO/sub 2/)-covered micro-hotplates and the necessary driving and signal-conditioning circuitry. The operating temperature of the SnO/sub 2/ resistor is between 200 and 350/spl deg/C. The on-chip temperature controller regulates the temperature of the membrane up to 350/spl deg/C with a resolution of 0.5/spl deg/C. A special heater design to achieve temperatures up to 350/spl deg/C with 5 V supply voltage was developed, which ensures homogeneous temperature distribution (1-2% maximum temperature fluctuation). Temperature sensors, on and off-membrane (near the circuitry), show excellent thermal isolation between the heated membrane area and the circuitry-area on the bulk chip (chip temperature rises by max 6/spl deg/C at 350/spl deg/C membrane temperature). A logarithmic converter was included to measuring the SnO/sub 2/ resistance change upon gas exposure over a range of four orders of magnitude.
Molecular surveillance of the antifolate-resistant mutation I164L in imported african isolates of Plasmodium falciparum in Europe: sentinel data from TropNetEurop
2003-06-25

Continuous molecular surveillance of mutations in P. falciparum, as it is practised within TropNetEurop, is an essential tool for the understanding and early detection of the spread of antimalarial drug resistance in Africa.
The through-the-lens metaphor: taxonomy and application
2003-06-25

We present a set of tools based on the through-the-lens metaphor. This metaphor enables simultaneous exploration of a virtual world from two different viewpoints. The one is used to display the surrounding environment and represents the user, the other is interactively adjusted and the resulting images are displayed in a dedicated window.
Maintenance of distributed systems with mobile agents
2003-06-25

We introduce the use of mobile agents for maintaining distributed heterogeneous systems with respect to monitoring and configuration. Code mobility can ensure the maintainability even for small and/or partially connected devices and scalability for highly distributed systems. Our approach leads to a system which allows to describe the jobs to perform in an abstract way. This is supported by a generalization of system parameters as well as the use of a rule-based decision system to describe the behavior of a mobile agent and its tasks. Application scenarios deploying our approach are illustrated showing the integration of different systems from PCs to embedded devices and even fieldbus nodes. Finally, differences to other approaches are discussed.
Worst-case performance analysis of parallel, communicating software processes
2003-06-25

In this paper we present a method to perform static timing analysis of SystemC models, that describe parallel, communicating software processes. The paper combines a worst-case execution time (WCET) analysis with an analysis of the communication behavior. The communication analysis allows the detection of points, where the program flow of two or more concurrent processes are synchronized. This knowledge allows the determination of the worst-case response time (WCRT). The method does not rely on restrictions on the system design to prevent deadlocks or data loss. Furthermore possible deadlocks and data loss can be detected during the analysis.
A qualification platform for design reuse
2003-06-25

The application and development of reusable components (intellectual property, IP) has become a regular part of modern design practices. The IP provider on one side and the IP integrator (user) on the other may be in the same company or separate participants in the microelectronic design market. In both cases, the transfer of IP remains a complex and time-consuming task. The qualification of IP gains a significant relevance for successful application and transfer of IP. This paper proposes an IP qualification methodology for an automated quality check that also incorporates current standards. Through embedding of the new concept into the regular design flow, IP transfer comes closer to an easy mix and match of virtual components. The presented approach has been validated during an industrial case study.
Hardware implementation of the subdivision loop algorithm
2003-06-25

The demand for higher quality in the graphical representation of 3D scenes is continuously increasing. Subdivision of triangular meshes is one of the most employed techniques for improving the quality of these rendered images. The high communication requirements between the CPU and the graphics system associated with this kind of method can be considerably reduced if the subdivision task is carried out in hardware, within a new unit placed at the entry of the standard graphics pipeline. In this paper we present a comparative analysis of two possible implementations of this hardware unit, corresponding to two different alternatives for applying loop subdivision to triangle meshes: subdivision based on forward differencing and on meshing scheme. In the first case, the amount of information sent to the graphics pipeline grows linearly with the level of subdivision; whereas, with the meshing scheme the communication requirements are lower and independent of the subdivision level.
Formal data analysis of timed finite state systems
2003-06-25

Formal verification has become an alternative to simulation for the validation of systems. In particular, temporal logic model checking of finite state machines is a widely accepted verification technique. It automatically proves the correctness of design specifications. There exist several approaches extending model checking for the verification of timed systems. Things become more complex if additional multivalued signals are added to the systems. In this constellation, time effects and data dependencies merge. Therefore, a stand-alone model checking approach is in many cases not sufficient for verification, especially if extreme values of signals have to be determined. We extend an existing real-time finite state model by multivalued signals (ranges, enumerations and bit vectors). We present algorithms for computing minimal and maximal values of signals in specified states or within certain time bounds. We show the practicability of our approach by means of a case study.
Identification of and symmetry computation for crystal nets
2003-06-26

Exact methods are presented to determine whether two periodic nets are combinatorially isomorphic and to compute the full combinatorial symmetry group of a net. It is found that for a large class of nets, which includes all known zeolite nets and most other known crystal nets, this group can be realized as a crystallographic space group.
Interactive rendering of large volume data sets
2003-06-26

We present a new algorithm for rendering very large volume data sets at interactive frame rates on standard PC hardware. The algorithm accepts scalar data sampled on a regular grid as input. The input data is converted into a compressed hierarchical wavelet representation in a preprocessing step. During rendering, the wavelet representation is decompressed on-the-fly and rendered using hardware texture mapping. The level of detail used for rendering is adapted to the local frequency spectrum of the data and its position relative to the viewer. Using a prototype implementation of the algorithm we were able to perform an interactive walkthrough of large data sets such as the visible human on a single off-the-shelf PC.
Cytosolic and mitochondrial isoforms of NADP+‐dependent isocitrate dehydrogenases are expressed in cultured rat neurons, astrocytes, oligodendrocytes and microglial cells
2003-06-26

Abstract NADP + ‐dependent isocitrate dehydrogenases (ICDHs) are enzymes that reduce NADP + to NADPH using isocitrate as electron donor. Cytosolic and mitochondrial isoforms of ICDH have been described. Little is known on the expression of ICDHs in brain cells. We have cloned the rat mitochondrial ICDH (mICDH) in order to obtain the sequence information necessary to study the expression of ICDHs in brain cells by RT‐PCR. The cDNA sequence of rat mICDH was highly homologous to that of mICDH cDNAs from other species. By RT‐PCR the presence of mRNAs for both the cytosolic and the mitochondrial ICDHs was demonstrated for cultured rat neurons, astrocytes, oligodendrocytes and microglia. The expression of both ICDH isoenzymes was confirmed by western blot analysis using ICDH‐isoenzyme specific antibodies as well as by determination of ICDH activities in cytosolic and mitochondrial fractions of the neural cell cultures. In astroglial and microglial cultures, the total ICDH activity was almost equally distributed between cytosolic and mitochondrial fractions. In contrast, in cultures of neurons and oligodendrocytes about 75% of total ICDH activity was present in the cytosolic fractions. Putative functions of ICDHs in cytosol and mitochondria of brain cells are discussed.
Maximum entropy light source placement
2003-06-26

Finding the "best" viewing parameters for a scene is a difficult but very important problem. Fully automatic procedures seem to be impossible as the notion of "best" strongly depends on human judgment as well as on the application. In this paper a solution to the sub-problem of placing light sources for given camera parameters is proposed. A light position is defined to be optimal, when the resulting illumination reveals more about the scene than illuminations from all other light positions, i.e. the light position maximizes information that is added to the image through the illumination. With the help of an experiment with several subjects we could adapt the information measure to the actually perceived information content. We present fast global optimization procedures and solutions for two and more light sources.
Delayed Sodium Channel Inactivation Mimics Long QT Syndrome 3
2003-06-26

DPI 201-106 delays sodium channel inactivation. Acute administration of DPI 201-106 prolonged the QT interval, provoked spontaneous torsades de pointes in one patient, and facilitated stimulation-induced polymorphic ventricular tachyarrhythmias in two patients. Similar to the observations in animal studies, delaying sodium channel inactivation is a new form of the acquired long QT syndrome, mimicking long QT syndrome type 3.
A case study on automatic camera placement and motion for visualizing historical data
2003-06-26

In this paper, we address the problem of automatic camera positioning and automatic camera path generation in the context of historical data visualization. After short description of the given data, we elaborate on the constraints for the positioning of a virtual camera in such a way that not only the projected area is maximized, but also the depth of the displayed scene. This is especially important when displaying terrain models, which do not provide good 3D impression when only the projected area is maximized. Based on this concept, we present a method for computing an optimal camera position for each instant of time. Since the explored data are not static, but change depending on the explored scene time, we also discuss a method for animation generation. In order to avoid sudden changes of the camera position, when the previous method is applied for each frame (point in time), we introduce pseudo-events in time, which expand the bounding box defined by the currently active events of interest. In particular, this technique allows events happening in a future point in time to be taken into account such that when this time becomes current, all events of interest are already within the current viewing frustum of the camera.