X-ray response of tunnel junctions with a trapping layer

The use of trapping layers in superconductive tunnel junctions may drastically improve their functioning as X-ray detectors. Information about these trapping layers can be obtained from I/V-curves and X-ray spectra. The application of a magnetic field causes a substantial reduction of the bandgap in the trapping layer

PERSPECTIVE OF EXPLOITATION OF ALGINIT IN PLANT NUTRITION

Alginit je organicko-minerálna hornina, ktorá má v bohatom nálezisku pri Lučenci reálnu perspektívu širokého využitia. Alginit je fosílna riasa (algae), ktorá v Panónskej jazernej sústave pri vulkanických zmenách pred 3-4 miliónami rokmi spolu s erodovanými horninami vytvorila súvislý sediment. V práci sú zvýraznené jeho pedologicko-agrochemické parametre s významným zastúpením biogénnych N, P, K, Ca, Mg, stopových Cu, Mo, Mn, Se, ale i rizikových As, Cd, Pb, Hg prvkov. Doplnené sú hodnoty pH, obsah organického materiálu, ale i vysokovýznamnej sorpènej kapacity závislej od jeho polyminerálneho charakteru. Vlastnosti sú porovnané s prírodným materiálom podobného druhu, ktorý sa ťaží v Maďarsku a v širokom spektre sa využíva aj ako stabilizátor pôdnej úrodnosti s potvrdenými vlastnosťami pri viacerých poľnohospodárskych plodinách.Ore and non-ore potential of the Slovak Republic is restricted by the size of its area. Each successful result of geological research uncovering modest raw material supplies is considered to be worthy. Since 1990 the alginite bed situated in Lučenec Valley, locality of Picniná village, has been considered in the above mentioned sense. Alginite represents a rock with relatively high organic matter content which was sedimenting together with the clays in post - volcanic outbursts during geological periods appropriate for algae occurrence. An interest for this material is also stimulated by the experiences obtained during alginite mining from the deposit not far off Slovak - Hungarian boundary in Gercei and Pula in Hungary. Gercei alginite has a wide variety of utilization as an ecological raw material. By underlining pedological and agrochemical alginite value we intend to contribute to the realization of its utilization, especially in agriculture. First of all, the fact that specific and volume weight as well as the consistent constants and particularly specific surface value of alginite exclusively positively influence physical and chemical soil properties should be emphasized here. Content of biogenic and trace elements, portion of colloidal fraction, humus content and sorption capacity have a determinative significance for prospective alginite involving into an assortment of progressive preparations for soil properties improving. Natural character, absence of phytotoxicity, effective economy of mining technology and ecologization of farming systems, those are the arguments for alginite to be included among such materials like zeolites and bentonites which have already achieved a possition for useful agricultural utilization

The role of vestibular cues in postural sway

Controlling posture requires continuous sensory feedback about body motion and orientation, including from the vestibular organs. Little is known about the role of tilt vs. translation vs. rotation vestibular cues. We examined whether intersubject differences in vestibular function were correlated with intersubject differences in postural control. Vestibular function was assayed using vestibular direction-recognition perceptual thresholds, which determine the smallest motion that can be reliably perceived by a subject seated on a motorized platform in the dark. In study A, we measured thresholds for lateral translation, vertical translation, yaw rotation, and head-centered roll tilts. In study B, we measured thresholds for roll, pitch, and left anterior-right posterior and right anterior-left posterior tilts. Center-of-pressure (CoP) sway was measured in sensory organization tests (study A) and Romberg tests (study B). We found a strong positive relationship between CoP sway and lateral translation thresholds but not CoP sway and other thresholds. This finding suggests that the vestibular encoding of lateral translation may contribute substantially to balance control. Since thresholds assay sensory noise, our results support the hypothesis that vestibular noise contributes to spontaneous postural sway. Specifically, we found that lateral translation thresholds explained more of the variation in postural sway in postural test conditions with altered proprioceptive cues (vs. a solid surface), consistent with postural sway being more dependent on vestibular noise when the vestibular contribution to balance is higher. These results have potential implications for vestibular implants, balance prostheses, and physical therapy exercises.NEW & NOTEWORTHY Vestibular feedback is important for postural control, but little is known about the role of tilt cues vs. translation cues vs. rotation cues. We studied healthy human subjects with no known vestibular pathology or symptoms. Our findings showed that vestibular encoding of lateral translation correlated with medial-lateral postural sway, consistent with lateral translation cues contributing to balance control. This adds support to the hypothesis that vestibular noise contributes to spontaneous postural sway

Topological Defect Densities in Type-I Superconducting Phase Transitions

We examine the consequences of a cubic term addition to the mean-field potential of Ginzburg-Landau theory to describe first order superconductive phase transitions. Constraints on its existence are obtained from experiment, which are used to assess its impact on topological defect creation. We find no fundamental changes in either the Kibble-Zurek or Hindmarsh-Rajantie predictions.Comment: Revtex4, 1 eps figure, 6 pages. Change in title and in sections II and III so to broaden the scope of the paper. Additional author is include

Reduced Regional NREM Sleep Slow-Wave Activity Is Associated With Cognitive Impairment in Parkinson Disease

Growing evidence implicates a distinct role of disturbed slow-wave sleep in neurodegenerative diseases. Reduced non-rapid eye movement (NREM) sleep slow-wave activity (SWA), a marker of slow-wave sleep intensity, has been linked with age-related cognitive impairment and Alzheimer disease pathology. However, it remains debated if SWA is associated with cognition in Parkinson disease (PD). Here, we investigated the relationship of regional SWA with cognitive performance in PD. In the present study, 140 non-demented PD patients underwent polysomnography and were administered the Montréal Cognitive Assessment (MoCA) to screen for cognitive impairment. We performed spectral analysis of frontal, central, and occipital sleep electroencephalography (EEG) derivations to measure SWA, and spectral power in other frequency bands, which we compared to cognition using linear mixed models. We found that worse MoCA performance was associated with reduced 1–4 Hz SWA in a region-dependent manner (F2, 687 =11.67, p < 0.001). This effect was driven by reduced regional SWA in the lower delta frequencies, with a strong association of worse MoCA performance with reduced 1–2 Hz SWA (F2, 687 =18.0, p < 0.001). The association of MoCA with 1–2 Hz SWA (and 1–4 Hz SWA) followed an antero-posterior gradient, with strongest, weaker, and absent associations over frontal (rho = 0.33, p < 0.001), central (rho = 0.28, p < 0.001), and occipital derivations, respectively. Our study shows that cognitive impairment in PD is associated with reduced NREM sleep SWA, predominantly in lower delta frequencies (1–2 Hz) and over frontal regions. This finding suggests a potential role of reduced frontal slow-wave sleep intensity in cognitive impairment in PD

Response of parylene-coated NaI(Tl) scintillators at low temperature

Despite that it is widely used as a scintillator at room temperature, the hygroscopicity of NaI complicates its handling and limits its application for many purposes, for example as a cryogenic detector. To overcome this problem we study coating materials that can act as humidity barriers, in particular parylene, a polymer that can be deposited in very radiopure, thin and conformal layers. In this work, several NaI(Tl) samples coated with 2-5 µm parylene-C were tested at low temperature. Luminescence spectra under X-ray excitation are presented at several temperatures as well as the light output vs temperature at 1.5-300 K. Several thermoluminescence peaks were observed at around 60, 95 and 150 K during warm up to room temperature The mechanical resistance of the coating under thermal cycles was also investigated, and we observed a degradation of the optical appearance and the light output after cooling down to about 100 mK, which compromises the reusability of the samples