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To determine the effect of three psycholinguistic variables—lexical frequency, age of acquisition (AoA), and neighborhood density (ND)—on lexical-semantic processing in individuals with non-fluent (nfvPPA), logopenic (lvPPA), and semantic primary progressive aphasia (svPPA). Identifying the scope and independence of these features can provide valuable information about the organization of words in our mind and brain.
We administered a lexical decision task—with words carefully selected to permit distinguishing lexical frequency, AoA, and orthographic ND effects—to 41 individuals with PPA (13 nfvPPA, 14 lvPPA, 14 svPPA) and 25 controls.
Of the psycholinguistic variables studied, lexical frequency had the largest influence on lexical-semantic processing, but AoA and ND also played an independent role. The results reflect a brain-language relationship with different proportional effects of frequency, AoA, and ND in the PPA variants, in a pattern that is consistent with the organization of the mental lexicon. Individuals with nfvPPA and lvPPA experienced an ND effect consistent with the role of inferior frontal and temporoparietal regions in lexical analysis and word form processing. By contrast, individuals with svPPA experienced an AoA effect consistent with the role of the anterior temporal lobe in semantic processing.
The findings are in line with a hierarchical mental lexicon structure with a conceptual (semantic) and a lexeme (word-form) level, such that a selective deficit at one of these levels of the mental lexicon manifests differently in lexical-semantic processing performance, consistent with the affected language-specific brain region in each PPA variant.
While hot-water drilling is a well-established technique used to access the subsurface of ice masses, drilling into high-elevation (≳ 4000 m a.s.l.) debris-covered glaciers faces specific challenges. First, restricted transport capacity limits individual equipment items to a volume and mass that can be slung by small helicopters. Second, low atmospheric oxygen and pressure reduces the effectiveness of combustion, limiting a system's ability to pump and heat water. Third, thick supraglacial debris, which is both highly uneven and unstable, inhibits direct access to the ice surface, hinders the manoeuvring of equipment and limits secure sites for equipment placement. Fourth, englacial debris can slow the drilling rate such that continued drilling becomes impracticable and/or boreholes deviate substantially from vertical. Because of these challenges, field-based englacial and subglacial data required to calibrate numerical models of high-elevation debris-covered glaciers are scarce or absent. Here, we summarise our experiences of hot-water drilling over two field seasons (2017–2018) at the debris-covered Khumbu Glacier, Nepal, where we melted 27 boreholes up to 192 m length, at elevations between 4900 and 5200 m a.s.l. We describe the drilling equipment and operation, evaluate the effectiveness of our approach and suggest equipment and methodological adaptations for future use.
Anecdotal evidence suggests the use of bolus tube feeding is increasing in long term home enteral tube feed (HETF) patients. A cross-sectional survey to assess the prevalence of bolus tube feeding and to characterise these patients was undertaken. Dietitians from 10 centres across the UK collected data on all adult HETF patients on the dietetic caseload receiving bolus tube feeding, (n=604, 60% male, age 58years). Demographic data, reasons for tube and bolus feeding, tube and equipment types, feeding method and patients’ complete tube feeding regimens were recorded. Over a third of patients receiving HETF used bolus feeding (37%). Patients were long-term tube fed (4.1years tube feeding, 3.5years bolus tube feeding), living at home (71%) and sedentary (70%). The majority were head and neck cancer patients (22%) who were significantly more active (79%) and lived at home (97%), while those with cerebral palsy (12%) were typically younger (age 31years) but sedentary (94%). Most patients used bolus feeding as their sole feeding method (46%), because it was quick and easy to use, as a top up to oral diet or to mimic meal times. Importantly, oral nutritional supplements (ONS) were used for bolus feeding in 85% of patients, with 51% of these being compact-style ONS (2.4kcal/ml, 125ml). This survey shows that bolus tube feeding is common amongst UK HETF patients, is used by a wide variety of patient groups and can be adapted to meet the needs of a variety of patients, clinical conditions, nutritional requirements and lifestyles.
The Indian Supreme Court has been called “the most powerful court in the world” for its wide jurisdiction, its expansive understanding of its own powers, and the billion plus people under its authority. Yet scholars and policy makers have a very uneven picture of the court’s functioning: deep knowledge about the more visible, “high-profile” cases but very little about more mundane, but far more numerous and potentially equally important, decisions. This chapter aims to address this imbalance with a rigorous, empirical account of the Court’s decisions from 2010 to 2015. We use the most extensive original dataset of Indian Supreme Court opinions yet created to provide a broad, quantitative overview of the social identity of the litigants that approach the court, the types of matters they bring to the court, the levels of success that different groups of litigants have before the Court, and the opinion-writing patterns of the various judges of the Supreme Court. This analysis provides foundational facts for the study of the Court and its role in progressive social change.
Hematite (α-Fe2O3) powder compacts have been subjected to controlled, quantitative high pressure shock loading at peak pressures from 8-27 GPa and preserved for post shook analysis. The broadened x-ray diffraction peak profiles have been analyzed to determine the residual lattice strain and the coherent crystallite sizes. Maximum modification effects are observed near 17 GPa with strain values near 3 x 10-3 and size values near 200 Å suggesting annealing at higher shock pressure, resulting from the higher shock temperature.
Preferred orientations in powder diffraction specimens can cause large errors in measured intensities. An extreme case is shown in Figure 1, Smith and Barrett (1979) reviewed the various methods which have been proposed for reducing this effect. Subsequently, two methods which are used commercially for aggregating finely divided solids have been proposed for preparing powder diffraction specimens (Smith, Snyder, and Brownell, 1979; Calvert and Sirianni, 1980). In one of these, spray drying, a finely divided solid is suspended in a liquid together with small quantities of a deflocculent and a binder. This mixture is pulled by venturi action through a nozzle into a heated chamber. The spherically shaped aggregates dry before falling to a collection surface. The apparatus is fairly large (3 X 3 X 4 ft. at NBS), and operating parameters must be carefully chosen.
Neutron powder diffraction techniques have been used to characterize the pseudo-macro (PM) residual stresses in ZrO2(CeO2)/Al2O3 ceramic composites as a function of ZrO2(CeO2) volume fraction and fabrication procedures. The diffraction data were analyzed using the Rietveld structure refinement technique. From the refinement, we found that the CeO2 stabilized tetragonal ZrO2 particles were in tension and the Al2O3 matrix was in compression. Different sintering time had little impact on the PM stresses. On the other hand, the magnitude of the PM stresses in both ZrO2 and Al2O3 decreased linearly with the increase of their volume fractions.
Techniques for the computer-assisted evaluation of crystallographic data have been developed to improve the data compilations of the NBS Crystal Data Center and the JCPDS—International Centre for Diffraction Data. The resulting computer program, NBS*ATDS80, can be used for the analysis of unit-cell and powder data by the general scientific community as well. NBS*AIDS80 is written in FORTRAN to permit implementation on a wide variety of computers, and input may be from cards or from a terminal. The research and analysis components that will be of use to the individual scientist include the following:
1) Calculation of the Crystal Data cell, determinative ratios, and space group for the comparison and reporting of unit cell parameters in a standard setting and for the identification of unknowns.
2) Determination of the reduced cell, reduced form number, and the unit cell with the highest metric symmetry.
3) Calculation of the molecular weight from the formula using the most recent atomic weights, and comparison of the density calculated by the program with the measured density.
4) Generation of d-spacings and indices for any input cell and crystal system.
5) Comparison of input powder data with calculated d-spacings, indexing of lines based on known unit cell parameters, and calculation of figures of merit.
Several kilometers of drill core are sometimes obtained when the geology of a particular area is explored. The cores are visually inspected and a limited number of samples are taken for laboratory analysis. Accurate chemical analyses are usually performed on only a small number of core sections because of the expense involved. A chemical profile along the core may provide useful information not available by any other means. This information may be of primary value for geological investigations or it may provide an additional basis for selecting samples for detailed laboratory analyses.
The beryllium diamond-anvil pressure cell described by Weir, Piermarini and Block has been mounted on a Bond diffractometer equipped with an orienter of the fixed-x type. Molybdenum radiation is used to penetrate the diamonds and beryllium of which the cell is constructed, and special techniques are required to retain adequate precision in measuring cell parameters using diffraction angles in the low 2θ range. The method described provides high sensitivity in determining peak positions and eliminates the effect of centering errors on measured values of 2θ. Under favorable conditions, diffraction angles are measured with an accuracy of ±0.001° in 2θ. The method has been tested by measuring the lattice parameter of vacuum float zone refined silicon. Measurements of the compressibilities of silicon and of α-Pb(N3)2 (orthorhombic) have been carried out using the method of Barnett, Block, and Piermarini to determine pressure by measuring the shift in the R-line fluorescence spectrum of ruby.
Depth profiles of intrinsic in-plane, biaxial stresses were obtained as a function of τ, the 1/e penetration depth, in a 1.0 um thick planar d. c. magentron sputter deposited molybdenum film using asymmetric grazing incidence x-ray diffraction (GIXD). τ was varied between 20 and 276 Å. The stresses σ11 and σ22 were characterized in the directions parallel and perpendicular to the long axis of the cathode respectively using a cos2φ method. The results show that starting from τ=17Å, σ11 and σ22 are compressive and become rapidly more compressive with a minimum at τ ∼ 20 - 40 Å thereafter increasing gradually toward tensile values. The reasons for the shape of the stress gradient are not well understood but may be related to the relaxation of the stresses at the tops of the columnar Zone T-type microstructure and to the oxygen gradient in the film.
This paper reports and discusses the results of a computer modeling study on powder diffraction profile analysis for crystallite size and strain of polycrystalline materials. The results of this computer modeling show that if the spans of diffraction profiles in reciprocal space (1/d) are not carefully chosen, an overestimation on size and an underestimation on strain may result in analysis by both the Warren-Averbach and the Hall-Williamson methods. A general way to eliminate such errors based on profile fitting and regeneration is presented and discussed in this paper.
We review our current understanding of the interior structure and thermal evolution of Saturn, with a focus on recent results in the Cassini era. There has been important progress in understanding physical inputs, including equations of state of planetary materials and their mixtures, physical parameters like the gravity field and rotation rate, and constraints on Saturnian free oscillations. At the same time, new methods of calculation, including work on the gravity field of rotating fluid bodies, and the role of interior composition gradients, should help to better constrain the state of Saturn’s interior, now and earlier in its history. However, a better appreciation of modeling uncertainties and degeneracies, along with a greater exploration of modeling phase space, still leave great uncertainties in our understanding of Saturn’s interior. Further analysis of Cassini data sets, as well as precise gravity field measurements from the Cassini Grand Finale orbits, will further revolutionize our understanding of Saturn’s interior over the next few years.