julilili42/papers huggingface dataset:
The dependence of luminous efficiency on chromatic adaptation
2008-12-01

We investigated the dependence of luminous efficiency on background chromaticity by measuring 25-Hz heterochromatic flicker photometry (HFP) matches in six genotyped male observers on 21 different 1000-photopic-troland adapting fields: 14 spectral ones ranging from 430 to 670 nm and 7 bichromatic mixtures of 478 and 577 nm that varied in luminance ratio. Each function was analyzed in terms of the best-fitting linear combination of the long- (L) and middle- (M) wavelength sensitive cone fundamentals of A. Stockman and L. T. Sharpe (2000). Taking into account the adapting effects of both the backgrounds and the targets, we found that luminous efficiency between 603 and 535 nm could be predicted by a simple model in which the relative L- and M-cone weights are inversely proportional to the mean cone excitations produced in each cone type multiplied by a single factor, which was roughly independent of background wavelength (and may reflect relative L:M cone numerosity). On backgrounds shorter than 535 nm and longer than 603 nm, the M-cone contribution to luminous efficiency falls short of the proportionality prediction but most likely for different reasons in the two spectral regions.
Membrane androgen receptor activation triggers down-regulation of PI-3K/Akt/NF-kappaB activity and induces apoptotic responses via Bad, FasL and caspase-3 in DU145 prostate cancer cells
2008-12-01

Abstract Background Recently we have reported membrane androgen receptors-induced apoptotic regression of prostate cancer cells regulated by Rho/ROCK/actin signaling. In the present study we explored the specificity of these receptors and we analyzed downstream effectors controlling survival and apoptosis in hormone refractory DU145-prostate cancer cells stimulated with membrane androgen receptor-selective agonists. Results Using membrane impermeable conjugates of serum albumin covalently linked to testosterone, we show here down-regulation of the activity of pro-survival gene products, namely PI-3K/Akt and NF-κB, in DU145 cells. Testosterone-albumin conjugates further induced FasL expression. A FasL blocking peptide abrogated membrane androgen receptors-dependent apoptosis. In addition, testosterone-albumin conjugates increased caspase-3 and Bad protein activity. The actin cytoskeleton drug cytochalasin B and the ROCK inhibitor Y-27632 inhibited FasL induction and caspase-3 activation, indicating that the newly identified Rho/Rock/actin signaling may regulate the downstream pro-apoptotic effectors in DU145 cells. Finally, other steroids or steroid-albumin conjugates did not interfere with these receptors indicating testosterone specificity. Conclusion Collectively, our results provide novel mechanistic insights pointing to specific pro-apoptotic molecules controlling membrane androgen receptors-induced apoptotic regression of prostate cancer cells and corroborate previously published observations on the potential use of membrane androgen receptor-agonists as novel anti-tumor agents in prostate cancer.
Moving minds: Ethical aspects of neural motor prostheses
2008-12-01

Abstract Modern brain technology is a highly dynamic and innovative field of research with great potential for medical applications. Recent advances in recording neural signals from the brain by brain‐machine interfacing presage new therapeutic options for paralyzed people by means of neural motor prostheses. This paper examines foreseeable ethical questions related to the research on brainmachine interfaces and their possible future applications. It identifies four major topics that need to be considered: first, the questions of personality and its possible alterations; second, responsibility and its possible constraints; third, therapeutic applications and their possible exceedance; and fourth, questions of research ethics that arise when progressing from animal experimentation to application to human subjects. This paper, in identifying and addressing the ethical questions raised by brain‐machine interfaces, presents concerns that need to be considered if possible prosthetics based on modern brain technology are to be used cautiously and responsibly.
Benchmarking the quality of breast cancer care in a nationwide voluntary system: the first five-year results (2003–2007) from Germany as a proof of concept
2008-12-01

Abstract Background The main study objectives were: to establish a nationwide voluntary collaborative network of breast centres with independent data analysis; to define suitable quality indicators (QIs) for benchmarking the quality of breast cancer (BC) care; to demonstrate existing differences in BC care quality; and to show that BC care quality improved with benchmarking from 2003 to 2007. Methods BC centres participated voluntarily in a scientific benchmarking procedure. A generic XML-based data set was developed and used for data collection. Nine guideline-based quality targets serving as rate-based QIs were initially defined, reviewed annually and modified or expanded accordingly. QI changes over time were analysed descriptively. Results During 2003–2007, respective increases in participating breast centres and postoperatively confirmed BCs were from 59 to 220 and from 5,994 to 31,656 (&gt; 60% of new BCs/year in Germany). Starting from 9 process QIs, 12 QIs were developed by 2007 as surrogates for long-term outcome. Results for most QIs increased. From 2003 to 2007, the most notable increases seen were for preoperative histological confirmation of diagnosis (58% (in 2003) to 88% (in 2007)), appropriate endocrine therapy in hormone receptor-positive patients (27 to 93%), appropriate radiotherapy after breast-conserving therapy (20 to 79%) and appropriate radiotherapy after mastectomy (8 to 65%). Conclusion Nationwide external benchmarking of BC care is feasible and successful. The benchmarking system described allows both comparisons among participating institutions as well as the tracking of changes in average quality of care over time for the network as a whole. Marked QI increases indicate improved quality of BC care.
Tectonic control on the late stage exhumation of the Aar Massif (Switzerland): Constraints from apatite fission track and (U‐Th)/He data
2008-12-01

We examine the hypothesis that Pliocene exhumation of the external massifs in the central Alps is controlled by climatic change. New thermochronological data from the western Gastern‐Aar massif are used to investigate the timing, extent, and reasons for Neogene exhumation. Our data reveal that exhumation was constant with 0.5 km/Ma over the last 10 Ma in the north. In the southern part, exhumation was of the same order until ∼3.5 Ma but then increased gradually toward the south to values of up to 1.2 km/Ma, resulting in overall northward tilting of the western Aar massif. We explain this accelerated exhumation in the south after ∼3.5 Ma mainly by tectonic denudation in the footwall of the Rhône‐Simplon fault and discuss changes in deep crustal configuration, which may have triggered south directed normal faulting. We propose that the Rhône river was structurally trapped by the Rhône‐Simplon normal fault zone, which additionally enhanced erosion in the southern section of the Aar massif. Climatic forcing may have an impact in the very late stage of exhumation due to Alpine glaciation in the late Pliocene.
Hypothyroidism impairs chloride homeostasis and onset of inhibitory neurotransmission in developing auditory brainstem and hippocampal neurons
2008-12-01

Abstract Thyroid hormone (TH) deficiency during perinatal life causes a multitude of functional and morphological deficits in the brain. In rats and mice, TH dependency of neural maturation is particularly evident during the first 1–2 weeks of postnatal development. During the same period, synaptic transmission via the inhibitory transmitters glycine and GABA changes from excitatory depolarizing effects to inhibitory hyperpolarizing ones in most neurons [deploarizing–hyperpolarizing (D/H) shift]. The D/H shift is caused by the activation of the K + –Cl − co‐transporter KCC2 which extrudes Cl − from the cytosol, thus generating an inward‐directed electrochemical Cl − gradient. Here we analyzed whether the D/H shift and, consequently, the onset of inhibitory neurotransmission are influenced by TH. Gramicidin perforated‐patch recordings from auditory brainstem neurons of experimentally hypothyroid rats revealed depolarizing glycine effects until postnatal day (P)11, i.e. almost 1 week longer than in control rats, in which the D/H shift occurred at ∼P5–6. Likewise, until P12–13 the equilibrium potential E Gly in hypothyroids was more positive than the membrane resting potential. Normal E Gly could be restored upon TH substitution in P11–12 hypothyroids. These data demonstrate a disturbed Cl − homeostasis following TH deficiency and point to a delayed onset of synaptic inhibition. Interestingly, immunohistochemistry demonstrated an unchanged KCC2 distribution in hypothyroids, implying that TH deficiency did not affect KCC2 gene expression but may have impaired the functional status of KCC2. Hippocampal neurons of hypothyroid P16–17 rats also demonstrated an impaired Cl − homeostasis, indicating that TH may have promoted the D/H shift and maturation of synaptic inhibition throughout the brain.
Saxagliptin, a dipeptidyl peptidase IV inhibitor for the treatment of type 2 diabetes.
2008-12-01

Saxagliptin, a dipeptidyl peptidase-IV (DPP-IV) inhibitor, is currently under development by Bristol-Myers Squibb Co, AstraZeneca plc and Otsuka Pharmaceutical Co Ltd for the treatment of type 2 diabetes. The compound has high selectivity for DPP-IV compared with other dipeptidyl peptidases and a duration profile designed for once-daily dosing. DPP-IV inhibitors act by increasing levels of glucagon-like peptide-1, which stimulates insulin secretion. In animal studies, saxagliptin improved glucose clearance and raised insulin levels in rodents. Clinical trials have demonstrated a dose-dependent inhibition of DPP-IV by saxagliptin without serious side effects. Results have demonstrated that treatment with saxagliptin lowers blood glucose levels, with good tolerability and safety. The specific advantages of saxagliptin over other DPP-IV inhibitors may lie in its long-lived, effective and highly specific inhibition of DPP-IV, making once-daily treatment feasible, effective and safe.
A Comparison of Electrical Resistivity, Ground Penetrating Radar and Seismic Refraction Results at a River Terrace Site
2008-12-01

Electrical resistivity imaging (ERI), ground penetrating radar (GPR) and seismic refraction (SRF) profiles were repeated over three lines on a terrace of the Bow River. The site had a resistive gravel layer overlying mudstone bedrock with horizontal transitions to lacustrine and overbank deposits. Electrical resistivity results were best for determining changes in sediment types and detecting boundaries, but the ERI smoothness constraint blurred the location of the boundaries. The GPR gave the most resolution and showed internal structures that the other methods did not image. The GPR signal was severely attenuated in several areas where the surficial sediments became too conductive because of a fine grained component. The seismic refraction inversion provided good reproduction of the bedrock interface, but it did not detect changes in the composition of the surficial sediments. It also required the introduction of a low velocity surficial layer not indicated by the other methods that may be related to the increase in effective stress with depth. Jointly interpreting the three data sets gives a more reliable and less ambiguous interpretation than any single method. The data may be useful to test joint inversion algorithms and are available for download.
Magnets in motion
2008-12-01

We introduce magnetic interaction for rigid body simulation. Our approach is based on an equivalent dipole method and as such it is discrete from the ground up. Our approach is symmetric as we base both field and force computations on dipole interactions. Enriching rigid body simulation with magnetism allows for many new and interesting possibilities in computer animation and special effects. Our method also allows the accurate computation of magnetic fields for arbitrarily shaped objects, which is especially interesting for pedagogy as it allows the user to visually discover properties of magnetism which would otherwise be difficult to grasp. We demonstrate our method on a variety of problems and our results reflect intuitive as well as surprising effects. Our method is fast and can be coupled with any rigid body solver to simulate dozens of magnetic objects at interactive rates.
Temporal moments in geoelectrical monitoring of salt tracer experiments
2008-12-01

Monitoring of salt tracer experiments by electrical resistivity tomography (ERT) has been shown to be a valuable tool for characterizing the hydraulics of an aquifer, but efficient approaches of determining the spatial hydraulic conductivity distribution from ERT data are still missing. Standard inversion of ERT data obtained during salt tracer tests may even lead to estimates of the concentration distribution that are in contradiction to flow and transport of conservative compounds in porous media. In order to avoid nonphysical behavior, we consider the governing equations of groundwater flow, solute transport, and geoelectrics as a coupled system. While the tracer passes through the part of the domain that is sensitive for a particular electrode configuration, the measured electrical potential differences are perturbed. We characterize these perturbations by their temporal moments and relate them to the temporal moments of concentration, which themselves depend on hydraulic conductivity. We present temporal moment‐generating equations leading from the hydraulic conductivity field via heads and velocities to the temporal moments of concentration and electrical potential perturbations. The approach makes use of a linearized version of the Poisson equation. On the basis of this system of coupled steady state equations, we compute the sensitivity of electrical potential perturbations with respect to the log hydraulic conductivity distribution by the continuous adjoint state method for coupled systems. For demonstration, we simulate salt tracer experiments in a virtual quasi‐two‐dimensional sandbox, monitored by ERT. We show that the ratio of the first over the zeroth temporal moment of potential perturbation is less affected by the linearization of the Poisson equation than the zeroth and first moments themselves. Thus, it appears recommendable to use the ratio of first to zeroth moments also as data in inversion. We compare sensitivity patterns resulting from different electrode configurations. The methods of forward simulations and sensitivity calculations presented in this paper can be combined with any inverse kernel to develop a complete inverse model. Altogether, using temporal moments of potential perturbation appears promising for fully coupled hydrogeophysical inversion of ERT surveys during salt tracer tests.
The Influence of Matching Populations on Kinematic and Kinetic Variables in Runners With Iliotibial Band Syndrome
2008-12-01

The purpose of this study was to assess how participant matching influences biomechanical variables when comparing healthy runners and runners with iliotibial band syndrome (ITBS). We examined 52 healthy runners (CO) and 18 with ITBS, using three-dimensional kinematics and pressure distribution. The study population was matched in three ways and compared with the biomechanical findings: ITBS versus CO I (unmatched), ITBS versus CO II (matched to gender) and ITBS versus CO III (matched to gender height, and weight). The final number of participants in each group was n = 18. The kinematic variables showed a dependency on the matching process. The largest statistically significant differences (after Bonferroni adjustment) in the frontal and transverse planes were between ITBS and CO III (p = .008). Pressure measurements were also dependent on the matching process, with decreasing and nonsignificant differences (p = .006) between ITBS and CO after refining the process (ITBS vs. CO III). The results of this study and the necessity of matching seem to be plausible (lever arms, different running styles). Data matching is important for understanding overuse injuries in running.
Filtered Z-Closure Supernetworks for Extracting and Visualizing Recurrent Signal from Incongruent Gene Trees
2008-12-01

Most modern phylogenetic inference methods assume that data should be fitted to a set of possible trees, from which the optimal tree is to be identified. A bifurcat ing tree-like diagram is thought to best represent evo lutionary history. This expectation follows largely from the view that (i) simultaneous divergence of multiple organismal lineages from the same common ancestor is likely to be rare (Hennig, 1966), hence the bifurcat ing attribute; and (ii) reticulate patterns of relationship caused by hybridization, horizontal gene transfer, and gene conversion and recombination are relatively mi nor deviations from an underlying single bifurcating pattern of evolution (Brown et al., 2001; Daubin et al., 2003). Whether most of the pattern of evolutionary history is truly bifurcating is still uncertain, but it has become in creasingly evident that complications such as hybridiza tion, horizontal gene transfer, and lineage sorting of ancestral polymorphisms are not as rare as once sup posed (Takahashi et al., 2001; P??bo, 2003; Zhaxybayeva et al., 2004; Gogarten and Townsend, 2005). Under these conditions, individual gene histories may not be con gruent with the general pattern of species or higher taxon relationships, and a phylogenetic tree estimated from the combined (concatenated) gene sequence rep resents an oversimplified version of the genetic history (Huber and Moulton, 2005; Morrison, 2005; Huson and Bryant, 2006). An usual alternative to simultaneous anal ysis of combined sequences from multiple gene parti tions is to present a consensus tree as a representation of relationships common to each individual gene tree, but this also suffers from oversimplification (Swofford, 1991) and can be performed only when each gene tree has the same taxon representation. A solution to the oversimplification and taxon constraints to topological congruence would allow visualization of both the princi pal conflicting patterns among individual gene trees and the phylogenetic patterns common among trees that may not overlap completely in taxon representation (partial trees). Huson et al. (2004) presented the Z-closure method for constructing a supernetwork from a set of partial trees. In cases where gene trees contain numerous dif ferent incongruent relationships, the resulting supernet work can, however, be too complex to visualize and interpret. Huson et al. (2006), therefore, extended the supernetwork approach to enable filters to remove re lationships (splits) from the supernetwork that are rep resented only once or sporadically among the source trees. The result is a network that summarizes the rela
Association of two variants of the interferon-alpha receptor-1 gene with the presentation of hepatitis B virus infection.
2008-12-01

Interferon-alpha (IFNalpha) is a critical mediator of immunity to hepatitis B virus (HBV) infection. Although IFN has been used in the treatment of viral hepatitis for more than a decade, the role of IFN-alpha-receptor in HBV infection has not been intensively studied. We have evaluated the impact of two variants of the IFNAR1 gene on the outcome of HBV infection. Four hundred and fifty eight HBV-infected Vietnamese patients, with well-characterised clinical profiles including all forms of hepatic disease, and 160 non-infected, healthy Vietnamese individuals were enrolled in the study. Of these patients, 54 had acute hepatitis B, 88 had chronic hepatitis B, 118 had liver cirrhosis, 146 had a hepatocellular carcinoma and 52 were asymptomatic carriers of HBV. We analysed two SNPs for unequal distribution between these groups. The first SNP, rs1012335 is situated in intron 3 of the interferon alpha receptor 1 (IFNAR1). A C at position 17470 in the IFNAR1 on both chromosomes was detected more frequently in HBV-infected patients compared to healthy controls (OR: 2.6; 95% CI: 1.46-4.72, p < 0.001). The same homozygosity is also associated with higher concentrations of AST and ALT (aspartate and alanine amino-transferase) in the plasma of the patients. The second SNP (rs2257167) is situated in exon 4, causing a change of amino acids from Val (GTT) to Leu (CTT). Subjects having GTT on both chromosomes were more frequent in the healthy control group (OR: 0.54, 95% CI: 0.35-0.84, p = 0.004) and had lower plasma ALT concentrations. The findings indicate that two variants of the IFNAR1 gene are associated with the clinical presentation of HBV infection.
Integrating Logic Analyzer Functionality into VHDL Designs
2008-12-01

We present a combined hardware and software system for the debugging of FPGA designs. It provides a powerful logic analyzer implemented as a fully parameterized VHDL description. The system can insert the analyzer into a user design without manual labor required from the user. All processing is done on the VHDL-level, facilitating vendor-independent, source-level hardware debugging. The system also allows multiple independent FPGA-systems to be debugged in a single framework.
How computers can help us in creating an intuitive access to relativity
2008-12-01

Computers have added many new possibilities to the tool box used for visualizing science in general and relativity in particular. We present some new results from our own work: (2+1) dimensional Minkowski diagrams showing two spatial dimensions, extended wormhole visualization, and the illustration of accretion discs by using the approximation via a rigidly rotating disc of dust. We also discuss some related examples from our earlier work, such as interactive and immersive visualization, or the visualization of the warp drive metric.
Osseointegration of Chemically Modified Titanium Surfaces: An in Vivo Study
2008-12-01

In this study we investigated the in vivo effects of a chemically modified bioactive titanium surface on peri-implant bone formation and compared it with an untreated titanium surface. We identified the importance of surface roughness, hydrophilicity, and surface chemistry of the implant surface and their influence on peri-implant bone formation. The results of this study demonstrate that the chemically modified bioactive titanium surface does enhance bone formation and osseointegration.
Insider Trading in Germany — Do Corporate Insiders Exploit Inside Information?
2008-12-01

Abstract Our study focuses on the question whether corporate insiders in Germany exploit inside information while trading in their company’s stock. In contrast to prior international studies, which are not able to link insider transactions to a formal definition of inside information, we relate insider transactions to subsequent releases of inside information via ad-hoc news disclosures. We find evidence that corporate insiders as a group seem to trade on inside information. Moreover, members of the supervisory board seem to be most active in exploiting inside information, since they realize exceptionally high profits with their frequent front-running transactions.