julilili42/papers huggingface dataset:
Gross morphology and microstructure of type locality ossicles ofPsephophorus polygonusMeyer, 1847 (Testudines, Dermochelyidae)
2013-02-22

Abstract Psephophorus polygonus Meyer, 1847, the first fossil leatherback turtle to be named, was described on the basis of shell ossicles from the middle Miocene (MN6–7/8?) of Slovakia. The whereabouts of this material is uncertain but a slab on display at the Naturhistorisches Museum Wien is considered the neotype. We rediscovered further type locality ossicles in four European institutions, re-evaluated their gross morphology and described for the first time their microstructure by comparing them with Dermochelys coriacea , the only living dermochelyid turtle. The gross morphology is congruent with that already described for P. polygonus , but with two significant exceptions: the ridged ossicles of P. polygonus may have a distinctly concave ventral surface as well as a tectiform shape in cross-section. They do not develop the external keel typical of many ossicles of D. coriacea . Both ridged and non-ridged ossicles of P. polygonus are characterized by compact diploe structures with an internal cortex consisting of a coarse fibrous meshwork, whereas the proportionately thinner ossicles of D. coriacea tend to lose the internal cortex, and thus their diploe, during ontogeny. The ossicles of both P. polygonus and D. coriacea differ from those of other lineages of amniotes whose carapace is composed of polygonal ossicles or platelets, in having growth centres situated at the plate centres just interior to the external bone surface and not within the cancellous core or closer to the internal compact layer. The new diagnosis of P. polygonus allows us to preliminarily re-evaluate the taxonomy of some of the Psephophorus- like species. Despite some macro- and micromorphological differences, it seems likely that Psephophorus was as cosmopolitan as extant Dermochelys and had a broadly similar ecology, with a possible difference concerning the dive depth.
Mood and Processing of Proattitudinal and Counterattitudinal Messages
2013-02-22

Existing research has established the effects of mood on processing of clearly mood-elevating proattitudinal messages and clearly mood-threatening counterattitudinal messages (i.e., mood-relevant messages). Little is known, however, about mood effects on processing of less mood-elevating proattitudinal messages and less mood-threatening counterattitudinal messages (i.e., mood-irrelevant messages). The present research tested hypotheses regarding processing of mood-irrelevant messages based on a mood-congruent expectancies approach. Specifically, two studies were conducted in which prior attitudes were measured (Study 1) or manipulated (Study 2). As predicted, results showed higher scrutiny in negative mood given a proattitudinal message and in positive mood given a counterattitudinal message than in negative mood given a counterattitudinal message and in positive mood given a proattitudinal message. Discussion focuses on implications regarding the accumulated literature, different accounts proposed to understand mood effects on processing effort, and further research.
The Lisbon Agenda and Innovation-oriented Cohesion Policy: A New Challenge for Economic Integration among the EU Regions
2013-02-22

The EU's cohesion policy should now be confluent with the goals of the Lisbon strategy by promoting growth and employment.In this context the promotion of regional innovation systems has become important in the EU for guaranteeing long-term regional economic growth.This paper investigates the major determinants of varying degrees of innovation promotion from one region to another provided in the context of the EU's regional support program for the periods 2000~2006 and 2007~2013.While the new innovation-oriented policy appears to be incompatible with the goal of economic convergence among European regions, our research findings further question the consistency between the cohesion policy's objectives and its practice.
The runaway instability in general relativistic accretion discs
2013-02-23

When an accretion disc falls prey to the runaway instability, a large portion of its mass is devoured by the black hole within a few dynamical times. Despite decades of effort, it is still unclear under what conditions such an instability can occur. The technically most advanced relativistic simulations to date were unable to find a clear sign for the onset of the instability. In this work, we present three-dimensional relativistic hydrodynamics simulations of accretion discs around black holes in dynamical space–time. We focus on the configurations that are expected to be particularly prone to the development of this instability. We demonstrate, for the first time, that the fully self-consistent general relativistic evolution does indeed produce a runaway instability.
Auditory habituation in the fetus and neonate: an fMEG study
2013-02-23

Abstract Habituation – the most basic form of learning – is used to evaluate central nervous system (CNS) maturation and to detect abnormalities in fetal brain development. In the current study, habituation, stimulus specificity and dishabituation of auditory evoked responses were measured in fetuses and newborns using fetal magnetoencephalography ( fMEG ). An auditory habituation paradigm consisting of 100 trains of five 500 Hz tones, one 750 Hz tone (dishabituator) and two more 500 Hz tones, respectively, were presented to 41 fetuses (gestational age 30–39 weeks) and 22 newborns or babies (age 6–89 days). A response decrement between the first and fifth tones (habituation), an increment between the fifth tone and the dishabituator (stimulus specificity) and an increment between the fifth (last tone before the dishabituator) and seventh tones (first tone after the dishabituator) (dishabituation) were expected. Fetuses showed weak responses to the first tone. However, a significant response decrement between the second and fifth tones (habituation) and a significant increment between the fifth tone and the dishabituator (stimulus specificity) were found. No significant difference was found for dishabituation nor was a developmental trend found at the group level. From the neonatal data, significant values for stimulus specificity were found. Sensory fatigue or adaptation was ruled out as a reason for the response decrement due to the strong reactions to the dishabituator. Taken together, the current study used fMEG to directly show fetal habituation and provides evidence of fetal learning in the last trimester of pregnancy.
MAGNETIZED ACCRETION AND DEAD ZONES IN PROTOSTELLAR DISKS
2013-02-25

The edges of magnetically dead zones in protostellar disks have been proposed as locations where density bumps may arise, trapping planetesimals and helping form planets. Magneto-rotational turbulence in magnetically active zones provides both accretion of gas on the star and transport of mass to the dead zone. We investigate the location of the magnetically active regions in a protostellar disk around a solar-type star, varying the disk temperature, surface density profile, and dust-to-gas ratio. We also consider stellar masses between 0.4 and 2 M &amp;sun;, with corresponding adjustments in the disk mass and temperature. The dead zone's size and shape are found using the Elsasser number criterion with conductivities including the contributions from ions, electrons, and charged fractal dust aggregates. The charged species' abundances are found using the approach proposed by Okuzumi. The dead zone is in most cases defined by the ambipolar diffusion. In our maps, the dead zone takes a variety of shapes, including a fish tail pointing away from the star and islands located on and off the midplane. The corresponding accretion rates vary with radius, indicating locations where the surface density will increase over time, and others where it will decrease. We show that density bumps do not readily grow near the dead zone's outer edge, independently of the disk parameters and the dust properties. Instead, the accretion rate peaks at the radius where the gas-phase metals freeze out. This could lead to clearing a valley in the surface density, and to a trap for pebbles located just outside the metal freezeout line.
Communication: Influence of graphene interlayers on the interaction between cobalt phthalocyanine and Ni(111)
2013-02-25

The influence of graphene interlayers on electronic interface properties of cobalt phthalocyanine on Ni(111) is studied using both photoemission and X-ray absorption spectroscopy. A charge transfer associated with a redistribution of the d-electrons at the Co-atom of the phthalocyanine occurs at the interface to Ni(111). Even a graphene buffer layer cannot prevent the charge transfer at the interface to Ni(111); however, the detailed electronic situation is different.
Molecular Dynamics Reveal Binding Mode of Glutathionylspermidine by Trypanothione Synthetase
2013-02-25

The trypanothione synthetase (TryS) catalyses the two-step biosynthesis of trypanothione from spermidine and glutathione and is an attractive new drug target for the development of trypanocidal and antileishmanial drugs, especially since the structural information of TryS from Leishmania major has become available. Unfortunately, the TryS structure was solved without any of the substrates and lacks loop regions that are mechanistically important. This contribution describes docking and molecular dynamics simulations that led to further insights into trypanothione biosynthesis and, in particular, explains the binding modes of substrates for the second catalytic step. The structural model essentially confirm previously proposed binding sites for glutathione, ATP and two Mg2+ ions, which appear identical for both catalytic steps. The analysis of an unsolved loop region near the proposed spermidine binding site revealed a new pocket that was demonstrated to bind glutathionylspermidine in an inverted orientation. For the second step of trypanothione synthesis glutathionylspermidine is bound in a way that preferentially allows N1-glutathionylation of N8-glutathionylspermidine, classifying N8-glutathionylspermidine as the favoured substrate. By inhibitor docking, the binding site for N8-glutathionylspermidine was characterised as druggable.
Voluntary suppression of thoughts is influenced by anxious and ruminative tendencies in healthy volunteers
2013-02-25

Replicating thought suppression effects with the Think/No-Think paradigm (TNT) has failed in some studies investigating the phenomenon of below-baseline recall of suppressed stimuli. Attempts have been made to isolate factors that might explain inter-individual differences in suppression performance. Certain personality traits, whether associated with a pathological state or investigated in a community sample, have been shown to interfere with successful thought suppression and might be responsible for some of the negative results obtained in TNT studies. In the present study we investigate the influence of psychometric measures of depression and anxiety in a fairly large sample of healthy volunteers. We show that high brooding and anxious tendencies predict worse suppression performance. While no suppression was shown when investigating the TNT not taking the psychometric measures into account, including these two traits in the analysis resulted in a pattern of below-baseline recall only for low brooders and low anxious participants. We argue that inclusion of variables measuring personality traits is warranted using the TNT and that these variables already exert their influence at minimal levels of variance, significantly improving the interpretability of the results. Future research should therefore cautiously investigate potential confounding personality characteristics before analysing their data.
Do floating orbits in extreme mass ratio binary black holes exist?
2013-02-25

This paper examines the possibility of floating or non-decaying orbits for extreme mass ratio binary black holes. In the adiabatic approximation, valid in the extreme mass ratio case, if the orbital flux lost due to gravitational radiation reaction is compensated for by the orbital flux gained from the spins of the black holes via superradiant scattering (or, equivalently, tidal acceleration) the orbital decay would be stalled, causing the binary to "float". We show that this flux balance is not, in practice, possible for extreme mass ratio binary black holes with circular equatorial orbits; furthermore, adding eccentricity and inclination to the orbits will not significantly change this null result, thus ruling out the possibility of floating orbits for extreme mass ratio binary black holes. We also argue that binaries consisting of material bodies dense and massive enough to generate gravitational waves detectable by any kind of gravitational wave detector are also unlikely to float. Using a multipolar analysis, we show that a non-Kerr spacetime which could produce a floating orbit (given the same amount of tidal acceleration as in the case of a Kerr black hole) would need to be rapidly rotating prolate spheroid, which would be an exotic object indeed.
Comparison of Four Microwave Ablation Devices: An Experimental Study in ex Vivo Bovine Liver
2013-02-26

The largest ablation zone is obtained with systems B and C (three antennas) under maximum recommended ablation duration and with system A under short ablation time. The most spherical zone is obtained with system C (three antennas).
Soil Organic Carbon Pools and Stocks in Permafrost-Affected Soils on the Tibetan Plateau
2013-02-26

The Tibetan Plateau reacts particularly sensitively to possible effects of climate change. Approximately two thirds of the total area is affected by permafrost. To get a better understanding of the role of permafrost on soil organic carbon pools and stocks, investigations were carried out including both discontinuous (site Huashixia, HUA) and continuous permafrost (site Wudaoliang, WUD). Three organic carbon fractions were isolated using density separation combined with ultrasonic dispersion: the light fractions (<1.6 g cm(-3)) of free particulate organic matter (FPOM) and occluded particulate organic matter (OPOM), plus a heavy fraction (>1.6 g cm(-3)) of mineral associated organic matter (MOM). The fractions were analyzed for C, N, and their portion of organic C. FPOM contained an average SOC content of 252 g kg(-1). Higher SOC contents (320 g kg(-1)) were found in OPOM while MOM had the lowest SOC contents (29 g kg(-1)). Due to their lower density the easily decomposable fractions FPOM and OPOM contribute 27% (HUA) and 22% (WUD) to the total SOC stocks. In HUA mean SOC stocks (0-30 cm depth) account for 10.4 kg m(-2), compared to 3.4 kg m(-2) in WUD. 53% of the SOC is stored in the upper 10 cm in WUD, in HUA only 39%. Highest POM values of 36% occurred in profiles with high soil moisture content. SOC stocks, soil moisture and active layer thickness correlated strongly in discontinuous permafrost while no correlation between SOC stocks and active layer thickness and only a weak relation between soil moisture and SOC stocks could be found in continuous permafrost. Consequently, permafrost-affected soils in discontinuous permafrost environments are susceptible to soil moisture changes due to alterations in quantity and seasonal distribution of precipitation, increasing temperature and therefore evaporation.
Energy Level Alignment of a P3HT/Fullerene Blend during the Initial Steps of Degradation
2013-02-26

The influence of oxygen and light on the energy level alignment of a poly(3-hexylthiophene)/fullerene blend film used in organic photovoltaic devices is studied. Changes of the electronic structure as well as of the element distribution during the degradation under well-defined conditions are investigated simultaneously using X-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy. The valence energy level alignment in the blend was studied via core level shifts related to P3HT and the fluorinated fullerene, assuming a constant energetic separation between the corresponding core level and the HOMO (highest occupied molecular orbital). Upon exposure to oxygen and light, two different oxygen species were identified: a reversibly bound species which is responsible for the p-doping of the blend and an irreversibly formed species which corresponds to the photooxidation of the blend. P-doping lowers the common Fermi energy of the blend, leading to identical reductions in binding energies for both polymer and fullerene. Photo-oxidation also leads to the reduction of the binding energies of both components, however to different extents. This leads to a reduction of the distance of the HOMO levels of P3HT and fullerene by 180 meV.
Frameshifted prion proteins as pathological agents: Quantitative considerations
2013-02-26

A quantitatively consistent explanation for the titres of infectivity found in a variety of prion-containing preparations is provided on the basis that the ætiological agents of transmissible spongiform encephalopathy comprise a very small population fraction of prion protein (PrP) variants, which contain frameshifted elements in their N-terminal octapeptide-repeat regions. A mechanism for the replication of frameshifted prions is described and calculations are performed to obtain estimates of the concentration of these PrP variants in normal and infected brain, as well as their enrichment in products of protein misfolding cyclic amplification. These calculations resolve the lack of proper quantitative correlation between measures of infectivity and the presence of conformationally-altered, protease-resistant variants of PrP. Experiments, which could confirm or eventually exclude the role of frameshifted variants in the ætiology of prion disease, are suggested.
Reading “Sun” and Looking Up: The Influence of Language on Saccadic Eye Movements in the Vertical Dimension
2013-02-27

Traditionally, language processing has been attributed to a separate system in the brain, which supposedly works in an abstract propositional manner. However, there is increasing evidence suggesting that language processing is strongly interrelated with sensorimotor processing. Evidence for such an interrelation is typically drawn from interactions between language and perception or action. In the current study, the effect of words that refer to entities in the world with a typical location (e.g., sun, worm) on the planning of saccadic eye movements was investigated. Participants had to perform a lexical decision task on visually presented words and non-words. They responded by moving their eyes to a target in an upper (lower) screen position for a word (non-word) or vice versa. Eye movements were faster to locations compatible with the word's referent in the real world. These results provide evidence for the importance of linguistic stimuli in directing eye movements, even if the words do not directly transfer directional information.
Functional MRI in human subjects with gradient‐echo and spin‐echo EPI at 9.4 T
2013-02-27

Purpose The increased signal‐to‐noise ratio and blood oxygen level dependent signal at ultra‐high field can only help to boost the resolution in functional MRI studies if the spatial specificity of the activation signal is improved. At a field strength of 9.4 T, both gradient‐echo and spin‐echo based echo‐planar imaging were implemented and applied to investigate the specificity of human functional MRI. A finger tapping paradigm was used to acquire functional MRI data with scan parameters similar to standard neuroscientific applications. Methods Spatial resolution, echo, and readout times were varied to determine their influence on the distribution of the blood oxygen level dependent signal. High‐resolution co‐localized images were used to classify the signal according to its origin in veins or tissue. Results High‐quality activation maps were obtained with both sequences. Signal contributions from tissue were found to be smaller or slightly larger than from veins. Gradient‐echo echo‐planar imaging yielded lower ratios of micro‐/macro‐vascular signals of around 0.6 than spin‐echo based functional MRI, where this ratio varied between 0.75 and 1.02, with higher values for larger echo and shorter readout time. Conclusion This study demonstrates the feasibility of human functional MRI at 9.4 T with high spatial specificity. Although venous contributions could not be entirely suppressed, venous effects in spin‐echo echo‐planar imaging are significantly reduced compared with gradient‐echo echo‐planar imaging. Magn Reson Med 71:209–218, 2014. © 2013 Wiley Periodicals, Inc.
Amyotrophic lateral sclerosis progression and stability of brain-computer interface communication
2013-02-27

Our objective was to investigate the relationship between brain-computer interface (BCI) communication skill and disease progression in amyotrophic lateral sclerosis (ALS). We sought also to assess stability of BCI communication performance over time and whether it is related to the progression of neurological impairment before entering the locked-in state. A three years follow-up, BCI evaluation in a group of ALS patients (n = 24) was conducted. For a variety of reasons only three patients completed the three years follow-up. BCI communication skill and disability level, using the Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised, were assessed at admission and at each of the three follow-ups. Multiple non-parametric statistical methods were used to ensure reliability of the dependent variables: correlations, paired test and factor analysis of variance. Results demonstrated no significant relationship between BCI communication skill (BCI-CS) and disease evolution. The patients who performed the follow-up evaluations preserved their BCI-CS over time. Patients' age at admission correlated positively with the ability to achieve control over a BCI. In conclusion, disease evolution in ALS does not affect the ability to control a BCI for communication. BCI performance can be maintained in the different stages of the illness.
Testing for a Gap Junction-Mediated Bystander Effect in Retinitis Pigmentosa: Secondary Cone Death Is Not Altered by Deletion of Connexin36 from Cones
2013-02-27

Retinitis pigmentosa (RP) relates to a group of hereditary neurodegenerative diseases of the retina. On the cellular level, RP results in the primary death of rod photoreceptors, caused by rod-specific mutations, followed by a secondary degeneration of genetically normal cones. Different mechanisms may influence the spread of cell death from one photoreceptor type to the other. As one of these mechanisms a gap junction-mediated bystander effect was proposed, i.e., toxic molecules generated in dying rods and propagating through gap junctions induce the death of healthy cone photoreceptors. We investigated whether disruption of rod-cone coupling can prevent secondary cone death and reduce the spread of degeneration. We tested this hypothesis in two different mouse models for retinal degeneration (rhodopsin knockout and rd1) by crossbreeding them with connexin36-deficient mice as connexin36 represents the gap junction protein on the cone side and lack thereof most likely disrupts rod-cone coupling. Using immunohistochemistry, we compared the progress of cone degeneration between connexin36-deficient mouse mutants and their connexin36-expressing littermates at different ages and assessed the accompanied morphological changes during the onset (rhodopsin knockout) and later stages of secondary cone death (rd1 mutants). Connexin36-deficient mouse mutants showed the same time course of cone degeneration and the same morphological changes in second order neurons as their connexin36-expressing littermates. Thus, our results indicate that disruption of connexin36-mediated rod-cone coupling does not stop, delay or spatially restrict secondary cone degeneration and suggest that the gap junction-mediated bystander effect does not contribute to the progression of RP.