julilili42/papers huggingface dataset:
Characterization of potassium transport in wild‐type and isogenic yeast strains carrying all combinations of trk1, trk2 and tok1 null mutations
2003-01-15

Summary Saccharomyces cerevisiae cells express three defined potassium‐specific transport systems en‐coded by TRK1 , TRK2 and TOK1 . To gain a more complete understanding of the physiological function of these transport proteins, we have constructed a set of isogenic yeast strains carrying all combinations of trk1 Δ, trk2 Δ and tok1 Δ null mutations. The in vivo K + transport characteristics of each strain have been documented using growth‐based assays, and the in vitro biochemical and electrophysiological properties associated with K + transport have been determined. As has been reported previously, Trk1p and Trk2p facilitate high‐affinity potassium uptake and appear to be functionally redundant under a wide range of environmental conditions. In the absence of TRK1 and TRK2 , strains lack the ability specifically to take up K + , and trk1 Δ trk2 Δ double mutant cells depend upon poorly understood non‐specific cation uptake mechanisms for growth. Under conditions that impair the activity of the non‐specific uptake system, termed NSC1, we have found that the presence of functional Tok1p renders cells sensitive to Cs + . Based on this finding, we have established a growth‐based assay that monitors the in vivo activity of Tok1p.
Phases of asymmetric nuclear matter with broken space symmetries
2003-01-15

Isoscalar Cooper pairing in isospin asymmetric nuclear matter occurs between\\nstates populating two distinct Fermi surfaces, each for neutrons and protons.\\nThe transition from a BCS-like to the normal (unpaired) state, as the isospin\\nasymmetry is increased, is intervened by superconducting phases which\\nspontaneously break translational and rotational symmetries. One possibility is\\nthe formation of a condensate with a periodic crystallinelike structure where\\nCooper pairs carry net momentum (the nuclear\\nLarkin-Ovchinnikov-Fulde-Ferrell-phase). Alternatively, perturbations of the\\nFermi surfaces away from spherical symmetry allow for minima in the condensate\\nfree energy which correspond to a states with quadrupole deformations of Fermi\\nsurfaces and zero momentum of the Cooper pairs. In a combined treatment of\\nthese phases we show that, although the Cooper pairing with finite momentum\\nmight arise as a local minimum, the lowest energy state features are deformed\\nFermi surfaces and Cooper pairs with vanishing total momentum.\\n
An International Comparison and Assessment of Maternity Leave Legislation
2003-01-15

At present, we find legal provisions for maternity leave in almost every country. While these vary distinctly from country to country, their common and central feature is that they allow mothers to leave their workplace for a limited time around childbirth and to return to their jobs afterwards. This provision will typically impose costs on employers and affect the labor market situation of young women. However, there is no clear understanding about the nature and scope of these effects. Existing international comparisons typically include a large number of countries and only briefly review the regulations in place, concentrating on leave duration as a proxy for the costs of maternity leave imposed on the employer. In contrast, we compare maternity leave regulations in a limited number of countries in more detail (Denmark, Germany, the Netherlands, Japan, the U.S.A. and the U.K.), and we consider both, direct and indirect costs of maternity leave accruing to the employer. Concerning indirect costs, we distinguish the costs of human capital depreciation and the costs of re-organization: While the first will arguably rise with leave duration, the latter might be especially high for medium leave durations rendering work-sharing agreements problematic while not yet allowing for practicable replacement solutions. Furthermore, regulations affecting the predictability of leave duration will play an important role for the re-organization process and are consequently also included in the analysis.
Introduction to isolated horizons in numerical relativity
2003-01-17

We present a coordinate-independent method for extracting mass (M) and angular momentum (J) of a black hole in numerical simulations. This method, based on the isolated horizon framework, is applicable both at late times when the black hole has reached equilibrium, and at early times when the black holes are widely separated. We show how J and M can be determined in numerical simulations in terms of only those quantities which are intrinsic to the apparent horizon. We also present a numerical method for finding the rotational symmetry vector field (required to calculate J) on the horizon.
Misexpression of the Cyclin-Dependent Kinase Inhibitor ICK1/KRP1 in Single-Celled Arabidopsis Trichomes Reduces Endoreduplication and Cell Size and Induces Cell Death
2003-01-17

A positive correlation between cell size and DNA content has been recognized in many plant cell types. Conversely, misexpression of a dominant-negative cyclin-dependent kinase (CDK) or CDK inhibitor proteins (ICK/KRPs) in Arabidopsis and tobacco leaves has revealed that cell growth can be uncoupled from cell cycle progression and DNA content. However, cell growth also appears to be controlled in a non-cell-autonomous manner by organ size, making it difficult in a ubiquitous expression assay to judge the cell-autonomous function of putative cell growth regulators. Here, we investigated the function of the CDK inhibitor ICK1/KRP1 on cell growth and differentiation independent of any compensatory influence of an organ context using Arabidopsis trichomes as a model system. By analyzing cell size with respect to DNA content, we dissected cell growth in a DNA-dependent and a DNA-independent process. We further found that ICK1/KRP1 misexpression interfered with differentiation and induced cell death, linking cell cycle progression, differentiation, and cell death in plants. The function of ICK1/KRP1 in planta was found to be dependent on a C-terminal domain and regulated negatively by an N-terminal domain. Finally, we identified CDKA;1 and a D-type cyclin as possible targets of ICK1/KRP1 expression in vivo.
Discovery of A New Class of Pulsating Stars: Gravity-Mode Pulsators among Subdwarf B Stars
2003-01-17

During the course of an ongoing CCD monitoring program to investigate low-level light variations in subdwarf B (sdB) stars, we have serendipitously discovered a new class of low-amplitude, multimode sdB pulsators with periods of the order of an hour. These periods are more than a factor of 10 longer than those of previously known multimode sdB pulsators (EC 14026 stars), implying that they are due to gravity modes rather than pressure modes. The longer period pulsators are found only among cooler sdB stars, where they are surprisingly common. The iron opacity instability that drives the short-period EC 14026 stars is effective only in hot sdB stars, leaving the driving mechanism for the deeper gravity modes in cool sdB stars currently unknown. We present the first observational results for our newly identified sdB variables and discuss possible implications.
Moderate sun exposure and nevus counts in parents are associated with development of melanocytic nevi in childhood
2003-01-17

Abstract BACKGROUND Melanocytic nevi have been identified as the most important risk factor for cutaneous melanoma. Sun exposure, sunburns, and light pigmentation have been found to be associated with their development in childhood. To the authors' knowledge, nevus proneness of parents and the exact type of ultraviolet (UV) exposure have not yet been investigated in this context. The authors' objective was to determine independent risk factors and their impact for nevus development in childhood. METHODS The current study was conducted by two university departments of dermatology in 49 public nursery schools in Stuttgart, Germany and in 38 public nursery schools in Bochum, Germany. The cross‐sectional study included 1812 children aged 2–7 years and their parents. Total body nevus counts in children, assessment of pigmentary features, and nevus counts on the arms of parents were performed. Parents underwent a standardized interview concerning national origin and lifestyle features, as well as habits and magnitude of sun exposure of children. Analysis was performed by multivariate linear regression analysis and by multiple logistic regression analysis. RESULTS The number of nevi was found to steadily increase with age from a median of 3 at age 2 years to 19 at age 7 years ( P &lt; 0.0001). High numbers of nevi in children were associated with the number of weeks on sunny holidays, outdoor activities at home, skin type, facial freckling, ethnicity of parents, and the number of nevi on the arms of parents. Previously experienced sunburns failed significance ( P = 0.0620). CONCLUSIONS The authors found a strong association between nevus development in children and the number of parental moles, which most likely points to an inherited factor. Moderate sun exposure such as outdoor activities during a German summer without sunburns seemed to be sufficient for induction of melanocytic nevi. The authors believe that these findings will have direct impact on concepts for preventive strategies. Cancer 2003;97:628–38. © 2003 American Cancer Society. DOI 10.1002/cncr.11114
Charge-imbalance effects in intrinsic Josephson systems
2003-01-17

We report on two types of experiments with intrinsic Josephson systems made\\nfrom layered superconductors which show clear evidence of nonequilibrium\\neffects: 1. In 2-point measurements of IV-curves in the presence of high-\\nfrequency radiation a shift of the voltage of Shapiro steps from the canonical\\nvalue hf/(2e) has been observed. 2. In the IV-curves of double-mesa structures\\nan influence of the current through one mesa on the voltage measured on the\\nother mesa is detected. Both effects can be explained by charge-imbalance on\\nthe superconducting layers produced by the quasi-particle current, and can be\\ndescribed successfully by a recently developed theory of nonequilibrium effects\\nin intrinsic Josephson systems.\\n
[ITAL]XMM-Newton[/ITAL] Spectroscopy of the Accretion-driven Millisecond X-Ray Pulsar XTE J1751−305 in Outburst
2003-01-17

We present an analysis of the first high-resolution spectra measured from an accretion-driven millisecond X-ray pulsar in outburst. We observed XTE J1751-305 with XMM-Newton on 2002 April 7 for approximately 35 ksec. Using a simple absorbed blackbody plus power-law model, we measure an unabsorbed flux of (6.6 +/- 0.1) * 10^(-10) erg/cm^2/s (0.5--10.0 keV). A hard power-law component (Gamma = 1.44 +/- 0.01) contributes 83% of the unabsorbed flux in the 0.5-10.0 keV band, but a blackbody component (kT = 1.05 +/- 0.01 keV) is required. We find no clear evidence for narrow or broad emission or absorption lines in the time-averaged spectra, and the sensitivity of this observation has allowed us to set constraining upper-limits on the strength of important features. The lack of line features is at odds with spectra measured from some other X-ray binaries which share some similarities with XTE J1751-305. We discuss the implications of these findings on the accretion flow geometry in XTE J1751-305.
Interventions for mucous membrane pemphigoid and epidermolysis bullosa acquisita
2003-01-20

There is limited evidence (from two small trials) that severe ocular mucous membrane pemphigoid responds best to treatment with cyclophosphamide combined with corticosteroids, and that mild to moderate disease in most patients seems effectively suppressed by treatment with dapsone. It is difficult to make any treatment recommendations for EBA in the absence of reliable evidence sources.
Detection, tracking, and pursuit of humans with an autonomous mobile robot
2003-01-20

We present a system which is able to visually detect human faces, to track them by controlling a robot-head and to pursue a detected person by means of driving movements. The detection is based on a multimodal approach combining color, motion, and contour information. By using a stereo algorithm the position of the person in the scene is determined. Both the path of the person going ahead and a local environment map built by means of range sensor data are used to perform the navigation task. Stationary and dynamic obstacles are avoided during the process of pursuit.
Reconstruction and simplification of surfaces from contours
2003-01-20

In this paper we consider the problem of reconstructing triangular surfaces from given contours. An algorithm solving this problem has to decide which contours of two successive slices should be connected by the surface (branching problem), and, given that, which vertices of the assigned contours should be connected for the triangular mesh (correspondence problem). We present a new approach that solves both tasks in an elegant way. The main idea is to employ discrete distance fields enhanced with correspondence information. This allows us not only to connect vertices from successive slices in a reasonable way but also to solve the branching problem by creating intermediate contours where adjacent contours differ too much. Last but not least we show how the 2D-distance fields used in the reconstruction step can be converted to a 3D-distance field that can be advantageously exploited for distance calculations during a subsequent simplification step.
A "framework" for object oriented frameworks design
2003-01-20

Object-oriented frameworks are established tools for domain-specific reuse. Many framework design patterns have been documented, e.g. reverse engineering framework architectures from conventionally built applications for a given domain. The framework development cycle generally evolves from an open framework to a closed application. We describe a more flexible component-based approach to framework design that stresses a common interface for 'plugging-in' new components at different lifecycle stages. An analysis of framework-related user roles shows that the classical developer/end-user boundary is too rigid. We see the framework's development as a continuum within which its 'actors' can customise its behavior. This both increases the system's flexibility and reduces its maintenance requirement. A case study of three frameworks for different application domains illustrates the presented principles.
Imaging polarimetry of the rainbow
2003-01-20

Using imaging polarimetry, we measured the polarization patterns of a rainbow on the shore of the Finnish town of Oulu in July 2001. We present here high-resolution color-coded maps of the spatial distributions of the degree and angle of linear polarization of the rainbow in the red (650 +/- 30 nm), green (550 +/- 30 nm), and blue (450 +/- 30 nm) ranges of the spectrum. The measured polarization characteristics of the investigated rainbow support earlier theoretical and computational results and are in accordance with previous qualitative observations. To our knowledge, this is the first imaging polarimetric study of rainbow polarization.
Loss of Isotope Labeling in the Conversion of [18O2]Benzoic Acid into [18O]Benzoyl Chloride with Oxalyl Chloride
2003-01-20

Tell me where the 18O atoms are, where are they to be found? This question was raised when a large amount of the 18O labeling was lost in the course of the conversion of [18O2]benzoic acid into [18O]benzoyl chloride with oxalyl chloride. That the 13C marking in [carboxy-13C]benzoic acid was retained fully under the same conditions made the matter even more mysterious. Equilibration with 1,3-dioxetane (see scheme) or 1,3,5-trioxane intermediates can explain the oxygen-atom exchange with retention of identity of the carbon atom of the carbonyl group.
RoboSiM: Java 3D robot visualization
2003-01-20

The programming language Java has made it possible to develop device independent software. The authors introduce a robot visualization system implemented in Java. This graphical user interface is part of their robot simulation and monitoring system (RoboSiM). Currently two versions of the visualization exist, a Java 1.1 based system and its successor realized in Java 3D. Both applets display real or virtual robot arms and enable the user to manipulate this arm. Due to the support of distributed computing by Java and its platform independence, the Java GUI may run on different local and remote systems. Therefore the same robot may be controlled by a local user or via Intranet or Internet with the same applet. The GUI applet communicates directly with the control or simulation computer. In contrast to the Java 1.1 user interface, the Java 3D robot visualization is much more detailed. Compared with other visualization systems the Java 3D applet is very realistic. Therefore the Java display is a capable alternative to the traditional visualization.
Tracking and pursuing persons with a mobile robot
2003-01-20

In this paper we address the problem of detecting, tracking, and pursuing persons with a mobile robot in real-time. Our system consists of two cooperatively interacting parts: A visual gaze holding process using an active stereo vision system and a component controlling the trajectory of the robot. The detection process is based on an approach which combines color, motion, and contour information. Additionally, facial features and depth information are integrated to increase the robustness of detection. For navigation a potential field method is used taking into account the path of the person going ahead as well as a local environment map built by means of laser range sensor data. Consequently, stationary and dynamic obstacles can be avoided during the process of pursuit. The system is able to operate at approximately human walking rates.
Subretinal implants for the recovery of vision
2003-01-20

The German 'SubRet' consortium has fabricated various types of microphotodiode arrays, the photovoltaic response of which will induce a retina response after implantation in the subretinal space. Ultrathin and flexible devices have been designed as well as CMOS-based chips with different pixel sizes and electrode configurations. From in-vitro electrostimulation studies, it becomes clear that a purely photovoltaic mode of operation will not be feasible, but an additional energy input by near-infrared radiation or radio frequency power transmission needs to be incorporated. Implantation experiments on pigs and rabbits prove the biocompatibility, general function and local stability of the implants. The inner retina architecture is well preserved, and literally no glia proliferation is found from long-term monitoring and histological examination. In conclusion, the subretinal approach is very promising and our results are encouraging, although major obstacles cannot be excluded concerning the application in human.
Interactive exploration of extra- and interacranial blood vessels
2003-01-20

We present a system for interactive explorations of extra- and intracranial blood vessels. Starting with a stack of images from 3D angiography, we use virtual clips to limit the segmentation of the vessel tree to the parts the neuroradiologists are interested in. Furthermore, methods of interactive virtual endoscopy are applied in order to provide an interior view of the blood vessels.
Performance analysis of a RTOS by emulation of an embedded system
2003-01-20

We analyze the performance of two different real-time operating systems. Therefore, we used a real benchmark embedded system design with fast external reaction times of about 220 /spl mu/s. We show that for such fast reactive systems, the software overhead of a real-time operating system becomes a limiting factor. We analyze the influence of novel microcontroller features, e.g., different on-chip caches, which tend to accelerate execution, but make it less predictable. These investigations have been conducted using our own emulation environment called SPYDER-CORE-P1.
Mixed abstraction level hardware synthesis from SDL for rapid prototyping
2003-01-20

SDL is currently gaining interest as a system level specification language for HW/SW codesign. Automated synthesis of SDL in hardware so far had problems with its efficiency. The investigations on the resource usage of SDL-to-VHDL designs presented in this paper identify two key challenges: minimizing the overhead introduced by SDL process infrastructure, and choosing the appropriate synthesis method. This paper presents a framework for SDL hardware synthesis where VHDL code generation, high-level synthesis and RT-level synthesis are combined. A configurable run-time environment implements services like data handling and message passing in efficient, hand-coded library components, which take into account properties of the target architecture. For these components RT-level synthesis was found to be suitable. The behavior of each SDL process on the other hand is freely specified by the system designer. Depending on the type of application, i.e. complex data-oriented or control-oriented either high-level synthesis, RT-level synthesis, or a combination of both can prove to be optimal.
A memory addressing and access design for real time volume rendering
2003-01-20

This paper presents a memory addressing design that uses buffering to achieve a cache hit ratio of 95% for a PCI based Volume Rendering hardware accelerator. The target system for this memory interface is VIZARD II, a second generation PCI board using several XILINX chips. To improve the performance of this and possibly other hardware accelerators, a cubic addressing scheme is presented that improves the percentage of cache hits to misses. To further improve the performance the cubic addressing is coupled with several FIFO buffers to minimise the pipeline stalling effect of cache misses in the eight parallel memory modules. This combination of addressing scheme and memory access buffering raises the cache hit to miss ratio from 63% to 95%. Most Volume Rendering systems are fully pipelined and can utilise the design presented here to increase the number of frames per second and the quality of rendered images.
Estimating functional unit number in the PISH codedesign system by using Petri nets
2003-01-20

This work presents two approaches for computing the number of functional units in the PISH hardware/software codesign system. The proposed methods use Petri net as common formalism for performing quantitative analysis. The use of Petri net permits us to use a specification non-dependent partitioning method. Particularly, the Petri net as an intermediate format allows to analyze properties of the specification and formally compute performance indices which are used in the partitioning process. This paper is devoted to describing those approaches, but an overview of the general hardware/software codesign method is also presented.
Description and simulation of hardware/software systems with Java
2003-01-20

In this paper a newly developed object model is presented which allows the description of hardware/software systems in all its parts. An adaption of the component model, JavaBeans, allows to combine different kinds of reuse in one unitary language. A model based design flow and some tools are presented and applied to a JPEG example.
Hardware/software co-design for IP objects based on CORBA
2003-01-20

Innovation in the domain of reuse is driven by both the development of intellectual property (IP) components and accompanying standards for mix and match of these components within highly specialized design flows. The archiving and retrieving of IP blocks seems to be crucial since the level of quality is influenced by efficient and flexible query mechanisms. The innovation of the approach presented in the paper stems from providing an infrastructure for distributed and heterogeneous IP reuse databases based on CORBA mechanisms. The Reuse Management System (RMS) is now embedded into a CORBA environment that supports not only hardware but also software for hardware and software IP blocks and thus supports hardware/software co-design for system-on-chip (SOC) design.