julilili42/papers huggingface dataset:
Heat tolerance in Mediterranean land snails: histopathology after exposure to different temperature regimes
2008-11-19

The physiological and biochemical adaptation mechanisms of heat-tolerant snail species are poorly known. We investigated cellular adaptations to heat stress in four heat-exposed snail populations (two of Xeropicta derbentina, one each of Cernuella virgata and Theba pisana). Snails were exposed to different temperature regimes (25, 33, 38, 40, 43, 45, 48, 50 and 52°C) in the laboratory for 8 h. After exposure, immobility rates were determined and a qualitative and semi-quantitative histopathological analysis of the digestive gland (calcium and digestive cells) and mucocytes in the foot was conducted. In addition, the coloration of the shells was densitometrically determined. The shells of T. pisana were significantly darker than the shells of the other populations. The immobility rates and histopathological examinations showed that X. derbentina (both populations) was slightly better adapted to heat than C. virgata, and much better adapted than T. pisana. The observed differences in heat tolerance seemed to be connected to the ability for rapid and extreme proliferation of calcium cells in the digestive gland.
Hepatocarcinogenesis in mice with a conditional knockout of the hepatocyte growth factor receptor c‐Met
2008-11-19

Abstract The receptor for the hepatocyte growth factor/scatter factor (HGF/SF), c‐Met, plays a role in tumour promotion, progression and metastasis. In this study, we analysed chemically induced hepatocarcinogenesis in mice lacking a functional HGF receptor in their liver. Control and c‐Met deficient mice were injected with a single dose of N‐nitrosodiethylamine (DEN, 90 μg/g b.wt.) at 6 weeks of age and mice were subsequently kept on a phenobarbital (PB) containing diet (0.05%) for 35 weeks or on control diet. At the end of the experiment, the carcinogenic response in liver of the animals was monitored. Conditional c‐met knockout (KO) mice showed a higher prevalence of macroscopically visible liver tumours and of glutamine synthetase positive and glucose‐6‐phosphatase deficient lesions in liver. Tumour promotion by PB led to significant increases in the number of preneoplastic and neoplastic lesions in liver of both wild‐type and c‐met knockout mice, with only minor differences in response. Our results indicate that a defect in c‐Met‐mediated signaling increases chemically induced tumour initiation in liver but does not significantly affect PB‐mediated tumour promotion. © 2008 Wiley‐Liss, Inc.
A Graph-Based Approach to Symmetry Detection
2008-11-19

Symmetry detection aims at discovering redundancy in the form of reoccurring structures in geometric objects. In this paper, we present a new symmetry detection algorithm for geometry represented as point clouds that is based on analyzing a graph of surface features. We combine a general feature detection scheme with a RANSAC-based randomized subgraph searching algorithm in order to reliably detect reoccurring patterns of locally unique structures. A subsequent segmentation step based on a simultaneous region growing variant of the ICP algorithm is applied to verify that the actual point cloud data supports the pattern detected in the feature graphs. We apply our algorithm to synthetic and real-world 3D scanner data sets, demonstrating robust symmetry detection results in the presence of scanning artifacts and noise. The modular and flexible nature of the graph-based detection scheme allows for easy generalizations of the algorithm, which we demonstrate by applying the same technique to other data modalities such as images or triangle meshes.
Order-Based Representation in Random Networks of Cortical Neurons
2008-11-20

The wide range of time scales involved in neural excitability and synaptic transmission might lead to ongoing change in the temporal structure of responses to recurring stimulus presentations on a trial-to-trial basis. This is probably the most severe biophysical constraint on putative time-based primitives of stimulus representation in neuronal networks. Here we show that in spontaneously developing large-scale random networks of cortical neurons in vitro the order in which neurons are recruited following each stimulus is a naturally emerging representation primitive that is invariant to significant temporal changes in spike times. With a relatively small number of randomly sampled neurons, the information about stimulus position is fully retrievable from the recruitment order. The effective connectivity that makes order-based representation invariant to time warping is characterized by the existence of stations through which activity is required to pass in order to propagate further into the network. This study uncovers a simple invariant in a noisy biological network in vitro; its applicability under in vivo constraints remains to be seen.
Local turbulence simulations for the multiphase ISM
2008-11-20

In this paper we show results of numerical simulations for the turbulence in the interstellar medium. These results were obtained using a Riemann solver-free numerical scheme for high-Mach number hyperbolic equations. Here we especially concentrate on the physical properties of the ISM. That is, we do not present turbulence simulations trimmed to be applicable to the interstellar medium. The simulations are rather based on physical estimates for the relevant parameters of the interstellar gas. Applying our code to simulate the turbulent plasma motion within a typical interstellar molecular cloud, we investigate the influence of different equations of state (isothermal and adiabatic) on the statistical properties of the resulting turbulent structures. We find slightly different density power spectra and dispersion maps, while both cases yield qualitatively similar dissipative structures, and exhibit a departure from the classical Kolmogorov case towards a scaling described by the She-Leveque model. Solving the full energy equation with realistic heating/cooling terms appropriate for the diffuse interstellar gas, we are able to reproduce a realistic two-phase distribution of cold and warm plasma. When extracting maps of polarised intensity from our simulation data, we find encouraging similarity to actual observations. Finally, we compare the actual magnetic field strength of our simulations to its value inferred from the rotation measure. We find these to be systematically different by a factor of about 1.5, thus highlighting the often underestimated influence of varying line-of-sight particle densities on the magnetic field strength derived from observed rotation measures.
Discovery of photospheric Ca X emission lines in the far-UV spectrum of the hottest known white dwarf (KPD 0005+5106)
2008-11-20

For the first time, we have identified photospheric emission lines in the far-UV spectrum of a white dwarf. They were discovered in the Far Ultraviolet Spectroscopic Explorer spectrum of the hot (Teff~200,000 K) DO white dwarf KPD0005+5106 and they stem from extremely highly ionized calcium (CaX 1137, 1159 Ang). Their photospheric origin is confirmed by non-LTE line-formation calculations. This is the highest ionisation stage of any element ever observed in a stellar photosphere. Calcium has never been detected before in any hot white dwarf or central star of planetary nebula. The calcium abundance determination for KPD0005+5106 (1-10 times solar) is difficult, because the line strengths are rather sensitive to current uncertainties in the knowledge of effective temperature and surface gravity. We discuss the possibility that the calcium abundance is much lower than expected from diffusion/levitation equilibrium theory. The same emission lines are exhibited by the [WCE]-type central star NGC2371. Another CaX line pair (1461, 1504 Ang) is probably present in a Hubble Space Telescope spectrum of the PG1159-type central star NGC246.
Gauss-Hermite wave packet dynamics: convergence of the spectral and pseudo-spectral approximation
2008-11-20

The time-dependent linear Schrödinger equation for nuclei on the whole space is semidiscretized using Hermite and Gauss–Hermite basis functions. These are well suited, on the one hand, for the conservation properties of the numerical solution and, on the other hand, for their remarkable approximation properties. We investigate theoretically and numerically the convergence of the spectral and pseudo-spectral Gauss–Hermite semidiscretization schemes.
Selective Stylization for Visually Uniform Tangible AR
2008-11-20

In tangible user interfaces, physical props are used for direct interaction with a computer system. Tangible interaction applications often use augmented reality display techniques in order to overlay virtual graphical objects over the interaction area. This typically leads to the problem that the virtual augmentations have a distinct, simple computer-generated look, which makes them easily distinguishable from the real environment and physical props. Here, we present a new style of tangible interaction, which seamlessly combines real objects and graphical models. In the tangible user interaction zone of our system, physical objects and virtual models are displayed in the same technical illustration style. Regions outside of the interaction zone, and also the user's hands, are shown unaltered in order to maintain an unmodified visual feedback in these areas. Our example application is a tangible urban planning environment, in which the placement of both real and virtual building models affects the flow of wind and the casting of shadows. We describe the real-time rendering pipeline which generates the selectively stylized output images in the tangible interaction system and discuss the functionality of the urban planning application.
ChemInform Abstract: Multilateral Solid‐State Metathesis Reactions for the Preparation of Materials with Heteroanions: The [Si(CN2)4]4‐ Ion.
2008-11-20

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 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.
Tricuspid regurgitation in screening for trisomies 21, 18 and 13 and Turner syndrome at 11 + 0 to 13 + 6 weeks of gestation
2008-11-21

Abstract Objective To investigate the performance of first‐trimester screening for aneuploidies by including assessment of tricuspid blood flow in the combined test of maternal age, fetal nuchal translucency (NT) thickness, fetal heart rate (FHR) and serum free β‐human chorionic gonadotropin (β‐hCG) and pregnancy‐associated plasma protein A (PAPP‐A). Method Screening by the combined test was performed in singleton pregnancies, including 19 614 with chromosomally normal fetuses or the delivery of a phenotypically normal baby (euploid group), 122 with trisomy 21, 36 with trisomy 18, 20 with trisomy 13 and eight with Turner syndrome. In all cases tricuspid flow was assessed to determine if there was tricuspid regurgitation. We examined the performance of two screening strategies: firstly, assessment of tricuspid flow in all patients and secondly, first‐stage screening using the combined test in all patients followed by second‐stage assessment of tricuspid flow only in those with an intermediate risk of 1 in 51 to 1 in 1000 after the first stage. Results Tricuspid regurgitation was observed in 0.9% of the euploid fetuses and 55.7%, 33.3% and 30% of the fetuses with trisomies 21, 18 and 13, respectively, and in 37.5% of those with Turner syndrome. In a screening policy based on maternal age, fetal NT, FHR, serum free β‐hCG and PAPP‐A, for a fixed false positive rate of 3% the standardized detection rates were 91% for trisomy 21 and 100% for trisomy 18, trisomy 13 and Turner syndrome. Assessment of tricuspid flow in all pregnancies would increase the detection rate of trisomy 21 to 96%, and the detection rates of trisomy 18, trisomy 13 and Turner syndrome would be 92%, 100% and 100%, respectively. The same detection rates were achieved with the two‐stage strategy—in which it was necessary to assess tricuspid flow in only 15% of the total population—at a false positive rate of 2.4%. Conclusions Assessment of tricuspid flow improves the performance of first‐trimester screening for trisomy 21. Copyright © 2008 ISUOG. Published by John Wiley &amp; Sons, Ltd.
Metamictization in zircon. Part I: Raman investigation following a Rietveld approach: Profile line deconvolution technique.
2008-11-21

Abstract The line profile form of Raman spectra can be analyzed using the very same approach and software used for diffractogram deconvolution via the Rietveld approach. In both cases the ‘true’ profile containing information about the sample must be separated from the instrument's profile function (and potentially from the emission profile) which can be achieved by deconvolution. In this first part of a two‐part study we demonstrate how the instrument's function can be described via a Gaussian function profile (yielding the very same result as several convoluted hat functions) using several examples (diamond, calcite, silicon and silicon carbide) for which true Raman bandwidth values are presented (assuming the true band profile to be Lorentzian). Also, asymmetrical bands can be described and analyzed via the presented deconvolution approach. The second part of this study will discuss and apply this method for studying the radiation‐induced damage in zircon grains (metamictization). Copyright © 2008 John Wiley &amp; Sons, Ltd.
Comparison of in vitro safety profiles of vancomycin and cefuroxime on human corneal endothelial cells for intracameral use
2008-11-22

These data suggest a dose-dependent toxicity of cefuroxime and vancomycin on HCECs in vitro with a narrow range of safety. Although the clinically used concentrations seem to be safe, slightly higher concentrations might induce irreversible cell death and thus should be avoided.
Neutrino radiation from dense matter
2008-11-22

This article provides a concise review of the problem of neutrino radiation from dense matter. The subjects addressed include quantum kinetic equations for neutrino transport, collision integrals describing neutrino radiation through charged and neutral current interactions, radiation rates from pair-correlated baryonic and color superconducting quark matter.
AQP4 expression in striatal primary cultures is regulated by dopamine – implications for proliferation of astrocytes
2008-11-24

Abstract Proliferation of astrocytes plays an essential role during ontogeny and in the adult brain, where it occurs following trauma and in inflammation and neurodegenerative diseases as well as in normal, healthy mammals. The cellular mechanisms underlying glial proliferation remain poorly understood. As dopamine is known to modulate proliferation in different cell populations, we investigated the effects of dopamine on the proliferation of striatal astrocytes in vitro . We found that dopamine reduced proliferation. As proliferation involves, among other things, a change in cell volume, which normally comes with water movement across the membrane, water channels might represent a molecular target of the dopamine effect. Therefore we studied the effect of dopamine on aquaporin 4 (AQP4) expression, the main aquaporin subtype expressed in glial cells, and observed a down‐regulation of the AQP4‐M23 isoform. This down‐regulation was the cause of the dopamine‐induced decrease in proliferation as knockdown of AQP4 using siRNA techniques mimicked the effects of dopamine on proliferation. Furthermore, stimulation of glial proliferation by basic fibroblast growth factor was also abolished by knocking down AQP4. In addition, blocking of AQP4 with 10 μ m tetraethylammonium inhibited osmotically induced cell swelling and stimulation of glial cell proliferation by basic fibroblast growth factor. These results demonstrate a clear‐cut involvement of AQP4 in the regulation of proliferation and implicate that modulation of AQP4 could be used therapeutically in the treatment of neurodegenerative diseases as well as in the regulation of reactive astrogliosis by preventing or reducing the glia scar formation, thus improving regeneration following ischemia or other trauma.
Perfusion imaging of the pancreas using an arterial spin labeling technique
2008-11-24

Abstract Purpose To investigate the feasibility of perfusion imaging of the pancreas using an arterial spin labeling (ASL) technique. Materials and Methods An adapted flow‐sensitive alternating inversion recovery (FAIR)‐TrueFISP ASL technique was implemented on a 1.5T scanner. Anatomical and perfusion imaging in three different parts of the pancreas were performed in 10 healthy volunteers. Quantitative perfusion values were calculated using the extended Bloch equations. Results Perfusion images of all subjects showed diagnostic image quality in the pancreatic tail and the head. Assessment of pancreatic tissue perfusion was possible in all organ parts. Mean perfusion values were 271 ± 79 mL/100g/min in the head, 351 ± 112 mL/100g/min in the body, and 243 ± 55 mL/100g/min in the tail of the pancreas. Total examination time for perfusion imaging of the entire organ was 15.4 minutes. Conclusion FAIR‐TrueFISP permits analysis of pancreatic tissue perfusion with good image quality in a clinically applicable measuring time. Assessment of perfusion disorders may be useful in the diagnosis of inflammatory pancreatic pathologies, endocrine and exocrine pancreatic disorders, and in monitoring of pancreatic transplants. J. Magn. Reson. Imaging 2008;28:1459–1465. © 2008 Wiley‐Liss, Inc.
Measurement of T1, T2, and magnetization transfer properties during embryonic development at 7 Tesla using the chicken model
2008-11-24

Abstract Purpose To evaluate whether techniques of high field magnetic resonance imaging may be used to characterize embryonic tissue during proliferation and differentiation. Materials and Methods Thirteen chicken embryos with incubation times between 5 days and 16 days have been measured in a small animal magnetic resonance imager (ClinScan, Bruker) at 7 Tesla using the built‐in resonator. T1, T2‐, and magnetization transfer imaging was performed using fast spin‐echo with inversion recovery, half acquisition single shot turbo spin‐echo, and spoiled gradient‐echo sequences with and without off‐resonance pulse, respectively. T1, T2, and magnetization transfer ratio (MTR) maps were calculated on a pixel‐by‐pixel basis. Results T1‐, T2‐, and MTR maps showed good image quality allowing for delineation of embryonic organs. During embryonic development, a decrease of T1 and T2 relaxation times was found, whereas, embryonic tissue typically showed an increase of magnetization transfer, for example, liver properties at day 5: T1 = 2431 ± 163 ms, T2 = 122 ± 12 ms, MTR = 9.2 ± 4.2%; liver properties at day 16: T1 = 1763 ± 89 ms, T2 = 71 ± 4 ms, MTR = 16.9 ± 2.2%. Conclusion Embryonic tissues show changing relaxation and magnetization transfer properties during development, therefore, high field MRI seems suitable for characterization of tissue replacement derived from embryonic stem cells. J. Magn. Reson. Imaging 2008;28:1510–1514. © 2008 Wiley‐Liss, Inc.
Subcortical neglect is not always a transient phenomenon: Evidence from a 1-year follow-up study
2008-11-24

Compared to cortical lesions, spatial neglect following subcortical stroke is most frequently seen as a mild and transient phenomenon. Since this assumption is based on only few observations, we reexamined the prognosis and severity of spatial neglect in patients with circumscribed right-sided basal ganglia or thalamic lesions in the acute and in the chronic phase of the stroke. On average, 1.15 years after stroke, spatial neglect had persisted in about 40% of the patients with subcortical lesions. The severity was reduced to about one third. The results argue against the view that spatial neglect following subcortical lesions typically has a favorable prognosis.
Plasma Fetuin-A Levels and the Risk of Myocardial Infarction and Ischemic Stroke
2008-11-25

Background— Fetuin-A, a protein almost exclusively secreted by the liver, induces insulin resistance and subclinical inflammation in rodents. Circulating fetuin-A levels are elevated in humans with metabolic syndrome and insulin resistance, conditions that are associated with increased risk of cardiovascular disease. Methods and Results— We investigated the association between fetuin-A levels and the risk of future myocardial infarction (MI) and ischemic stroke (IS) in a case-cohort study based on the European Prospective Investigation into Cancer and Nutrition (EPIC)–Potsdam Study comprising 27 548 middle-aged subjects of the general population. Fetuin-A levels were measured in plasma of 227 individuals who developed MI, in 168 who developed IS, and in 2198 individuals who remained free of cardiovascular events during a mean follow-up of 8.2±2.2 years. Individuals in the highest compared with the lowest quintile of plasma fetuin-A had significantly increased risks of MI (relative risk, 3.80; 95% confidence interval, 2.37 to 6.10; P for trend &lt;0.0001) and IS (relative risk, 3.93; 95% confidence interval, 2.17 to 7.12; P for trend &lt;0.0001) after adjustment for sex and age. Additional adjustment for smoking status, body mass index, waist circumference, alcohol consumption, educational attainment, physical activity, hypertension, diabetes mellitus, total and high-density lipoprotein cholesterol, and C-reactive protein only moderately attenuated these risks (MI: relative risk, 3.25; 95% confidence interval, 2.01 to 5.28; P for trend &lt;0.0001; IS: relative risk, 3.78; 95% confidence interval, 2.06 to 6.94; P for trend &lt;0.0001). Conclusions— Our data provide evidence for a link between high plasma fetuin-A levels and an increased risk of MI and IS. Therefore, more research is warranted to determine the role of fetuin-A in the pathophysiology of cardiovascular disease.
Acral lentiginous melanoma: conventional histology vs. three-dimensional histology
2008-11-25

Clinical and surgical risk factors seem to have different influences on the outcome of ALM. 3D histology allows reduction of excision margins by two-thirds without an increased risk of local recurrences and with better prognosis. 3D immunohistology could be a valuable diagnostic tool to reduce the rate of local recurrences.
Epinephrine inhalers in emergency sets of patients with anaphylaxis
2008-11-25

Summary Emergency sets are prescribed to allow patients with anaphylaxis to treat themselves before professional aid arrives. The need for epinephrine in this setting is well‐accepted, but how it should be administered is still controversial. Epinephrine preparations can be administered orally, subcutaneously, intramuscularly or as aerosols. Primatene MistTM is one epinephrine inhaler, which is approved for asthma treatment in the USA, and InfectoKrupp ® Inhal is another one approved to support the treatment of acute laryngo‐tracheitis and of allergic reactions with a nebulizer. Both are possible components of the emergency set for patients with anaphylaxis. The following review article summarizes data currently available on the use of epinephrine preparations in first‐aid treatment of anaphylaxis. Studies have shown that the plasma concentrations needed for hemodynamic stabilization cannot be reached with epinephrine inhalers. Since most cases of hypotension in anaphylaxis cannot be effectively treated with epinephrine inhalers, the prescriber should be aware of this before including them in an emergency pack.