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Objectives: To describe multivariate base rates (MBRs) of low scores and reliable change (decline) scores on Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) in college athletes at baseline, as well as to assess MBR differences among demographic and medical history subpopulations. Methods: Data were reported on 15,909 participants (46.5% female) from the NCAA/DoD CARE Consortium. MBRs of ImPACT composite scores were derived using published CARE normative data and reliability metrics. MBRs of sex-corrected low scores were reported at <25th percentile (Low Average), <10th percentile (Borderline), and ≤2nd percentile (Impaired). MBRs of reliable decline scores were reported at the 75%, 90%, 95%, and 99% confidence intervals. We analyzed subgroups by sex, race, attention-deficit/hyperactivity disorder and/or learning disability (ADHD/LD), anxiety/depression, and concussion history using chi-square analyses. Results: Base rates of low scores and reliable decline scores on individual composites approximated the normative distribution. Athletes obtained ≥1 low score with frequencies of 63.4% (Low Average), 32.0% (Borderline), and 9.1% (Impaired). Athletes obtained ≥1 reliable decline score with frequencies of 66.8%, 32.2%, 18%, and 3.8%, respectively. Comparatively few athletes had low scores or reliable decline on ≥2 composite scores. Black/African American athletes and athletes with ADHD/LD had higher rates of low scores, while greater concussion history was associated with lower MBRs (p < .01). MBRs of reliable decline were not associated with demographic or medical factors. Conclusions: Clinical interpretation of low scores and reliable decline on ImPACT depends on the strictness of the low score cutoff, the reliable change criterion, and the number of scores exceeding these cutoffs. Race and ADHD influence the frequency of low scores at all cutoffs cross-sectionally.
We report on a novel light sensing scheme based on a silicon/fullerene-derivative hetero-junction that allows the realization of optoelectronic devices for the detection of near to mid infrared radiation. Despite the absent absorption of silicon and the fullerene-derivative for wavelengths beyond 1.1 µm and 0.72 µm, respectively, a hetero-junction of these materials absorbs and generates a photo-current due to absorption in the near to mid infrared. This photo-current is caused by an interfacial absorption mechanism .
Besides its scientific relevance, the simple fabrication process of the hetero-junction (e.g. the fullerene-derivative is deposited by spin-coating on Si) as well as its compatibility with the established and rather cheap CMOS technology makes the presented hybrid approach a promising candidate for widespread applications.
This article describes a formal proof of the Kepler conjecture on dense sphere packings in a combination of the HOL Light and Isabelle proof assistants. This paper constitutes the official published account of the now completed Flyspeck project.
The Dark Energy Survey is undertaking an observational programme imaging 1/4 of the southern hemisphere sky with unprecedented photometric accuracy. In the process of observing millions of faint stars and galaxies to constrain the parameters of the dark energy equation of state, the Dark Energy Survey will obtain pre-discovery images of the regions surrounding an estimated 100 gamma-ray bursts over 5 yr. Once gamma-ray bursts are detected by, e.g., the Swift satellite, the DES data will be extremely useful for follow-up observations by the transient astronomy community. We describe a recently-commissioned suite of software that listens continuously for automated notices of gamma-ray burst activity, collates information from archival DES data, and disseminates relevant data products back to the community in near-real-time. Of particular importance are the opportunities that non-public DES data provide for relative photometry of the optical counterparts of gamma-ray bursts, as well as for identifying key characteristics (e.g., photometric redshifts) of potential gamma-ray burst host galaxies. We provide the functional details of the DESAlert software, and its data products, and we show sample results from the application of DESAlert to numerous previously detected gamma-ray bursts, including the possible identification of several heretofore unknown gamma-ray burst hosts.
For Western culture, and particularly for women, the Greek lyric poet Sappho, has come down as the original poet of female desire as well as the original figure of same-sex female erotics. Sappho was renowned throughout the ancient world for the unique power and expressiveness of her lyricism. The three primary modes of representing Sappho during the early modern period, incorporating the garbled tradition of "the two Sapphos", were repeatedly elaborated and sometimes conflated. Sappho was represented: as the first example of female poetic excellence; as an early exemplar of the "unnatural" or monstrous sexuality of the tribade; and as a mythologized figure who acts the suicidal abandoned woman in the Ovidian tale of Sappho and Phaon. Apart from the appeal of Sappho's poems to classicists and poets challenging themselves via translation and the use of Aeolian meter, Sappho's representation as an originary poetic figure has captured the imagination of many generations.
The directional dark-field signal obtained with X-ray grating interferometry yields direction-dependent information about the X-ray scattering taking place inside the examined sample. It allows examination of its morphology without the requirement of resolving the micrometer size structures directly causing the scattering. The local morphology in turn gives rise to macroscopic mechanical properties of the investigated specimen. In this study, we investigate the relation between the biomechanical elasticity (Young’s modulus) and the measured directional dark-field parameters of a well-defined sample made of wood. In our proof-of-principle experiment, we found a correlation between Young’s modulus, the average dark-field signal, and the average dark-field anisotropy. Hence, we are able to show that directional dark-field imaging is a new method to predict mechanical sample properties. As grating interferometry provides absorption, phase-contrast, and dark-field data at the same time, this technique appears promising to combine imaging and mechanical testing in a single testing stage. Therefore, we believe that directional dark-field imaging will have a large impact in the materials science world.
We present an improved algorithm for the computation of Zariski chambers on algebraic surfaces. The new algorithm significantly outperforms the currently available method and therefore allows us to treat surfaces of high Picard number, where huge numbers of chambers occur. As an application, we efficiently compute the number of chambers supported by the lines on the Segre–Schur quartic.
Titanium-based ceramic supports designed for polymer electrolyte membrane fuel cells were synthesized, and catalytic activity was explored using electrochemical analysis. Synthesis of high surface area TiO2 and TiO supports was accomplished by rapidly heating a gel of polyethyleneimine-bound titanium in a tube furnace under a forming gas atmosphere. X-ray diffraction analysis revealed anatase phase formation for the TiO2 materials and crystallite sizes of less than 10 nm in both cases. Subsequent disposition of platinum through an incipient wetness approach leads to highly dispersed crystallites of platinum, less than 6 nm each, on the conductive supports. Scanning Electron Microscope (SEM)/energy dispersive x-ray analysis results showed a highly uniform Ti and Pt distribution on the surface of both materials. The supports without platinum are highly stable to acidic aqueous conditions and show no signs of oxygen reduction reactivity (ORR). However, once the 20 wt% platinum is added to the material, ORR activity comparable to XC-72-based materials is observed.
This article reports on the role of annealing on the development of microstructure and its concomitant effects on the thermoelectric properties of polycrystalline AgPbmSbTe2+m (m = 18, lead–antimony–silver–tellurium, LAST-18) compounds. The annealing temperature was varied by applying a gradient annealing method, where a 40-mm-long sample rod was heat treated in an axial temperature gradient spanning between 200 and 600 °C for 7 days. Transmission electron microscopy investigations revealed Ag2Te nanoparticles at a size of 20–250 nm in the matrix. A remarkable reduction in the thermal conductivity to as low as 0.8 W/mK was also recorded. The low thermal conductivity coupled with a large Seebeck coefficient of ∼320 μV/K led to high ZT of about 1.05 at 425 °C for the sample annealed at 505 °C. These results also demonstrate that samples annealed above 450 °C for long term are more thermally stable than those treated at lower temperatures.
MnO nanoparticles (NPs) were surface functionalized by two different approaches, (1) using a dopamine-poly(ethylene glycol) (PEG) (DA-PEG) ligand and (2) by encapsulation within a thin silica shell applying a novel approach. Both MnO@DA-PEG and MnO@SiO2 NPs exhibited excellent long-term stability in physiological solutions. In addition, the cytotoxic potential of both materials was comparatively low. Furthermore, owing to the magnetic properties of MnO NPs, both MnO@DA-PEG and MnO@SiO2 lead to a shortening of the longitudinal relaxation time T1 in MRI. In comparison to the PEGylated MnO NPs, the presence of a thin silica shell led to a greater stability of the MnO core itself by preventing excessive Mn ion leaching into aqueous solution.
The objective of the present study was to evaluate digestive physiological outcomes elicited by functional fibres fed to healthy adult men. A total of twenty-one healthy adult men were utilised in a cross-over design. Each subject received polydextrose (PDX) or soluble maize fibre (SCF) (21 g/d) or no supplemental fibre (no fibre control; NFC) in a snack bar. Periods were 21 d and faeces were collected during the last 5 d of each period. Food intake, including fibre intake, did not differ among treatments. Flatulence (P = 0·001) and distention (P = 0·07) were greatest when subjects consumed PDX or SCF. Reflux was greater (P = 0·04) when subjects consumed SCF compared with NFC. All tolerance scores were low ( < 2·5), indicating only slight discomfort. Faecal ammonia, 4-methylphenol, indole and branched-chain fatty acid concentrations were decreased (P < 0·01) when subjects consumed the functional fibre sources compared with NFC. Faecal acetate, propionate and butyrate concentrations were lower (P < 0·05) when subjects consumed PDX compared with SCF and NFC. Faecal pH was lower (P = 0·01) when subjects consumed SCF compared with NFC, while PDX was intermediate. Faecal wet weight was greatest (P = 0·03) when subjects consumed SCF compared with NFC. Faecal dry weight tended to be greater (P = 0·07) when subjects consumed PDX compared with NFC. The functional fibres led to 1·4 and 0·9 g (PDX and SCF, respectively) increases in faecal dry mass per g supplemental fibre intake. Bifidobacterium spp. concentrations were greater (P < 0·05) when subjects consumed SCF compared with NFC. These functional fibres appear to be beneficial to gut health while leading to minimal gastrointestinal upset.
Nowadays the application of micro devices in many fields like e.g. in the life sciences, chemistry and also optics strongly grows in importance. Micro structures often allow efficient processes with low resource consumption and the possibility of high integration. Typical examples are micro and nano titer plates for chemical screening or DNA chips for sequencing, micro mixers and reaction systems for synthesis on demand or micro optical elements like couplers for optical data transmission. Especially plastics are well suited for the cost effective large number fabrication, using high precision mould inserts with injection moulding or hot embossing. Since the micro devices become more and more complex (keywords: lab on a chip and micro total analysis systems, μ-TAS) the fabrication of mould inserts will be more expensive and time consuming. This is the reason why often methods of rapid prototyping are required for design qualification and functionality test purposes during the development. It will be demonstrated that Excimerlaser ablation is a well suited method for rapid prototyping of quasi-three-dimensional micro structures. Almost all polymers can be ablated by the UV laser radiation with very high accuracy, using mask projection techniques. Therefore, the choice of a suited polymer with adapted material properties like for e.g. chemical resistance, optical surface quality or bio-compatibility allows one to account for the requirements of the corresponding application. Moreover, the prototypes can easily be transformed into mould inserts for large number fabrication, using the Laser-LIGA technique. The corresponding technologies will be explained and demonstrated with the aid of several examples, especially taking into account the material aspects.
The ζ-phase, existing between 35 and 70% U in Pu, belongs to the high density phases seen from the point of view of systematics of allotropic modifications of Pu metal. Despite the volume per actinide atom only slightly higher than for α-Pu, it magnetic susceptibility is much higher than for α-Pu and exceeds even the δ-Pu value. Similarly, the Sommerfeld coefficient γ > 40 mJ/mol Pu K2 exceeds the experimental δ-Pu value. The data confirm that the volume is not the primary control parameter affecting the situation around the Fermi level of common Pu phases and they point against the traditional belief that they are essentially narrow 5f band systems.
Stress corrosion cracking (SCC) in light water reactor components has long been studied from a post mortem perspective, yielding insights into water chemistries and effects on crack propagation. Analysis of a cracked component does not effectively provide information on the corrosion events or on SCC initiation. It is important that microstructures of these early stages be understood because the original surface of the component formed during fabrication is often not the final surface condition that is exposed to reactor water. Pre-service grinding of reactor components and welds is performed for a variety of reasons, from aesthetics to preparation for non-destructive testing. It is this final surface microstructure that often controls SCC initiation. Surface and near-surface characteristics have been investigated in 304SS metal coupons on which controlled grinding was performed. These examinations indicate the extent of subsurface microstructural damage before high-temperature water exposure. Analytical electron microscopy techniques have been used to gain insights into possible surface precursors to corrosion damage and SCC initiation. Nanocrystalline grains were commonly found at the surface in lightly ground to heavily abraded materials within the first ˜0.5-10 ųm along with high dislocation densities, twinning and lath structures.
We present our work on the spin relaxation of electrons confined in SiGe islands. Ge islands are grown on unstructured and structured Si(100) substrates by MBE, and lead to strain in the Si layer that is deposited on top. These quantum dot structures are investigated by photoluminescence and electron spin resonance (ESR) experiments, the latter both in continuous wave and pulsed mode. We observe a g-factor and an ESR line width that correspond to Si conduction band electrons with additional inhomogeneous broadening.