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Unregulated care aides provide most of the direct care to nursing home residents. We previously reported the first demographic profile of care aides in Western Canada through the Translating Research in Elder Care (TREC) longitudinal research program (2007–2022) in applied health services. Here we describe demographic, health, and work life characteristics of aides from 91 nursing homes in Western Canada. Demographics and work life varied significantly across health regions and facility owner-operator models. Our longitudinal cohort of aides from Alberta and Winnipeg had higher emotional exhaustion (a negative attribute), professional efficacy (a positive attribute), and experience of dementia-related responsive behaviours from residents. Overall, results indicate little improvement or worsening of care aide health and quality of work life. Coupled with limited provincial or national initiatives for workforce planning and training of these workers, this signals a long-term care system ill-prepared to care effectively for Canada’s aging population.
The degradability characteristics of a wide range of grass silage types have been studied using the in sacco technique over a 48-hour period. Each silage was examined in three steers on two occasions, with pairs of bags being withdrawn at each sampling time. The steers had an average live weight of 270 kg and were fed once daily on silage, molassed sugar beet pulp and barley meal (5:3:2 on a dry matter basis), which supplied an average of 55 MJ ME per head daily.
The losses of dry matter, nitrogen, cell contents, hemicellulose and cellulose were followed. For the carbohydrate fractions, modifications of the methods of van Soest were used. For each of these components, asymptotic equations of the form: p = a + b (1-e−ct) were fitted, where a and b represent percentages of the amounts originally present in silage, c represents the proportional rate of degradation and t represents hours of incubation.
We investigated the hydrodynamic properties of cephalopod shell sculpture in two ways: 1) flow visualization experiments with sculptured shells; and 2) application of drag coefficient data for simple geometric bodies to cephalopod shells. Results of this work suggest:
1) the hydrodynamic effect of shell sculpture depends primarily on the size of the sculptural elements relative to the size of the shell and on the positions of sculpture elements on the shell and relative to each other.
2) sculpture is detrimental to swimming (reduces hydrodynamic efficiency) if it exceeds the height of the lower part of the shell's boundary layer.
3) sculpture is advantageous to swimming (increases efficiency) if it remains immersed in the boundary layer and induces premature conversion to turbulent boundary layer flow. To be hydrodynamically optimal, small shells (diam ≈ 10 cm) must have rough (sculptured) surfaces, whereas large shells (diam ≈ 100 cm) require smooth surfaces. Thus, in order to maintain maximum efficiency throughout life, the ontogeny of small individuals, or species, should be characterized by progressive roughening of the shell, while large forms should become increasingly smooth. Such allometries are observed among many ammonoids.
4) sculpture always has an effect on the flow around a cephalopod shell. In some species this effect was probably negligible, while in others, those with compressed shells especially, it was probably of major importance. In these species, sculpture appears to have functioned primarily to increase swimming ability.
We describe a hybrid pixel array detector (electron microscope pixel array detector, or EMPAD) adapted for use in electron microscope applications, especially as a universal detector for scanning transmission electron microscopy. The 128×128 pixel detector consists of a 500 µm thick silicon diode array bump-bonded pixel-by-pixel to an application-specific integrated circuit. The in-pixel circuitry provides a 1,000,000:1 dynamic range within a single frame, allowing the direct electron beam to be imaged while still maintaining single electron sensitivity. A 1.1 kHz framing rate enables rapid data collection and minimizes sample drift distortions while scanning. By capturing the entire unsaturated diffraction pattern in scanning mode, one can simultaneously capture bright field, dark field, and phase contrast information, as well as being able to analyze the full scattering distribution, allowing true center of mass imaging. The scattering is recorded on an absolute scale, so that information such as local sample thickness can be directly determined. This paper describes the detector architecture, data acquisition system, and preliminary results from experiments with 80–200 keV electron beams.
The Antarctic Plateau provides the best terrestrial sites for infrared (IR) and submillimetre (sub-mm) astronomy. In this paper we examine the relative importance of temperature, aerosol content and precipitable water vapour to determine which parameters have the greatest influence on atmospheric transmission and sky brightness. We use the atmospheric modelling program MODTRAN to model the observed sky spectrum at the South Pole from the near-IR to the sub-mm. We find that temperature and aerosol content determine the quality of near-IR observing conditions, aerosol content is the determining factor in the mid-IR up to 20 μm, while at longer wavelengths, including the sub-mm, it is the water vapour content that matters. Finding a location where aerosol levels are minimised is a key constraint in determining the optimum site on the Antarctic Plateau for an IR observatory.
Two alkali-tin-silicate (ATS) glasses have been prepared at Argonne National
Laboratory (ANL) as part of our ongoing research in radioactive waste glass
development. These glasses dissolved 5% and approximately 7% Pu. Early
corrosion test results indicate that Pu-bearing ATS glass is extremely
durable. The initial goal in this project concerned equally both the
solubility of Pu and the durability of the ATS glasses; however, our primary
emphasis has changed recently to maximizing the loading of Pu in the glass.
ATS-based glasses, using Th(VI) and Ce(III) as surrogates for Pu(IV), are
now being investigated to increase the solubility of Pu without
substantially sacrificing the durability of the current ATS formulations.
The solution data from various corrosion tests on the original Pu-containing
ATS glasses are also presented.
Low energy ion bombardment has been utilized to fabricate rectifying contacts on aluminum nitride grown on single crystal silicon substrates. Bombardment of aluminum nitride with methane was followed by sputter deposition of gold contacts. To our knowledge, this is the first report of rectifying contact formation on aluminum nitride. Scanning electron micrographs show that the initially ordered aluminum nitride surface is significantly altered with low energy methane ion beam exposure. Electrical measurements made on samples which had been partially masked during implantation indicate that rectification is a result of the ion bombardment.
The origin of contact resistance in a-Si:H TFTs is investigated by formulating a model for the contact limited current. The Model accounts for the independent contributions of the Metal–n+a-Si:H interface resistance and the space charge limited conduction through the intrinsic a-Si:H film. Using our contact current model we investigated the I–V behavior of an n–i–n structure with a thin a-Si:H layer (=700Å) and found that the resistance of the Metal–n+a-Si:H interface is nonlinear. We incorporated the contact limited current expression into a full TFT Model and simulated the TFT performance for a wide range of Metal–n+a-Si:H interface resistance values and intrinsic a-Si:H film thicknesses. We found that the Metal–n+a-Si:H interface resistance dominates over space charge limited conduction for the thicknesses of intrinsic a-Si:H films used in AM-LCD switches. This trend is sustained even when the effective resistance of the Metal–n+a-Si:H interface decreases due to the nonlinear current conduction across it.
We developed a totally wet etch processing technology for the fabrication of inverted staggered amorphous silicon thin-film transistors (TFTs) and circuits. In this technology we take advantage of highly etch selective KOH and HF base solutions for amorphous silicon and silicon nitride layers. Our technology is simple, reproducible, fully compatible with positive photo-resist lithography techniques, and suitable for mass production of amorphous silicon TFT based circuits. Using this process, we fabricated thin film transistors which have an effective mobility of 0.83 cm2 V−1 s−1, threeshold voltage of 2V and on/off current ratio of 107. In this paper we discuss the details of our fabrication process and report on the chemical conditions of the etching and deposition processes.
Photo-transistor based a-Si:H image sensors allow the integration of photo-elements and pixel circuitry using standard TFT fabrication processes. While pixel circuitry use thin a-Si:H films (≈ 0.05μm) to minimize the contact resistance, photo-transistors require thick a-Si:H films (≈0.5μm) to maximize photo-sensitivity. We fabricated a new, high sensitivity photo-transistor structure using 0.05μ a-Si:H films. High optical sensitivity is achieved by separating the conduction paths of photo-generated electrons and holes using a secondary gate. Further, the optical path within the photo-transistor is doubled through manipulation of device layout. The photo-transistor show an Ilight/Idarkratio in excess of 103.
We compared the transient behavior of conventional and high-sensitivity photo-transistors. We found that both devices display an increase in current with time when biased in either the dark or illuminated conditions. The current increases by six orders of magnitudes then saturates within 200 seconds of bias application. Experiments indicate that this transient behavior is due to a rise in the conductivity of the gap region with time; measurements on 0.05μm thick photo-resistor structures showed that their current increases with time. The shape and temporal range of this behavior rules out the presence of parasitic capacitive effects.
We studied the effect of RF deposition power and temperature on the electrical and structural properties of plasma enhanced chemical vapor deposited (PECVD), heavily doped microcrystalline silicon films (n+μC-Si:H). The film growth process was found to be CVDlike at low powers and PVD-like (Physical Vapor Deposition) at high powers. We show that the film properties strongly depend on the nature of the growth process. We observed that at low temperatures the microcrystalline formation is mainly governed by the presence of hydrogen. This can be improved by increasing the substrate temperature. However, a further increase in substrate temperature tends to reduce hydrogen incorporation into the film and hence decreases the role of hydrogen in the formation of microcrystallites. Resistivities as low as 0.1 Ω.cm were achieved for 500Å thin layers deposited at a relatively low temperature of 220°C and power density of 40mW/cm2.
Conventional high voltage thin-film transistors (HVTFTs) suffer from performance limitations such as low on-current, Vx, shift and large curvature in the linear region of the output characteristics. These limitations are associated with the highly resistive dead region in conventional HVTFT structures. In this paper, we present a novel TFT structure which has a high on-current, improved output characteristics in the linear region, and no Vx shift. The higher on-current and significant improvement in output characteristics allows faster switching. Elimination of the Vx shift leads to more reliable circuit operation. The new structure is based on the conventional low voltage TFT (LVTFT) structure except that it does not suffer from low-voltage breakdown. The low-voltage breakdown of the gate nitride in conventional LVTFTs is perceived to be due to spiking of the drain metallization into the underlying layers which creates regions of very high electric field. In our novel structure, a higher breakdown is achieved by locating the metal contacts away from the gate edge while keeping the necessary drain to gate overlap through a heavily doped microcrystalline layer. Therefore, the new TFT extends the same performance as LVTFTs to high voltage operation. Furthermore, this structure also enhances the yield and reliability by minimizing the common faults in TFTs such as short circuits between gate, source and drain.
Conventional high voltage thin-film transistors (HVTFTs) suffer from performance limitations such as low on-current, Vx. shift and large curvature in the linear region of the output characteristics. These limitations are associated with the highly resistive dead region in conventional HVTFT structures. In this paper, we present a novel TFT structure which has a high on-current, improved output characteristics in the linear region, and no Vx, shift. The higher on-current and significant improvement in output characteristics allows faster switching. Elimination of the Vx shift leads to more reliable circuit operation. The new structure is based on the conventional low voltage TFT (LVTFT) structure except that it does not suffer from low-voltage breakdown. The low-voltage breakdown of the gate nitride in conventional LVTFTs is perceived to be due to spiking of the drain metallization into the underlying layers which creates regions of very high electric field. In our novel structure, a higher breakdown is achieved by locating the metal contacts away from the gate edge while keeping the necessary drain to gate overlap through a heavily doped microcrystalline layer. Therefore, the new TFT extends the same performance as LVTFTs to high voltage operation. Furthermore, this structure also enhances the yield and reliability by minimizing the common faults in TFTs such as short circuits between gate, source and drain.
In this paper we report on the development of micromachined filters for operation at terahertz frequencies. SU8, a negative photodefinable epoxy, is used to define arrays of high aspect ratio rods which are subsequently sputter coated in gold to form the filter. We fabricate and test a filter with a fixed period but variable diameter along the length of the array. By moving the array in the terahertz beam we demonstrate the ability to mechanically tune specific filter characteristics from a single device.
During the past decade, the number known shallow-amplitude, yet totally eclipsing, extreme-mass-ratio binaries has increased from one (AW UMa, which is now in doubt) to about a dozen. Statistics are accumulating that will tell us the nature of these once rare systems. These individual interacting field binaries are believed to be the progenitors of FK Comae-type fast-rotating subgiants, which are similar to the cluster stars called ‘variable blue stragglers.’ We review our recent observations and new analyses of the individual systems, V409 Hya, GSC 1283 0053 Ori, GSC 2537 520 CVn, using the 2007 Wilson Code and summarize results from our previous observations (V802 Aql, V902 Sgr) and those from the literature (e.g., CK Boo, GR Vir, HV Aqr, UY UMa, EM Pis, CU Tau, TV Mus) to disclose a preliminary picture of the character of this interesting class of binary stars.
The aim of this study was to investigate the developmental expression of major histocompatibility complex class II (MHCII) by microglia and macrophages and their relationship to blood vessels in the retina, a representative tissue of the central nervous system. Such information is crucial to understanding the role of these cells in immune surveillance. Wholemount preparations of retinas from late embryonic, postnatal and adult rabbits were subjected to three-colour fluorescence microscopy using β2 integrin (CD18) and MHCII antibodies and biotinylated Griffonia simplicifolia B4 isolectin labelling of blood vessels. CD18+ cells consistently exhibited characteristics of macrophages or microglia in the vascularized and non-vascularized regions of the retina, respectively. At all ages, MHCII was expressed by a high proportion of cells in the vascularized region, which contained macrophage-like ‘parenchymal cells’ as well as typical perivascular macrophages. MHCII expression by ramified microglia, first detected on postnatal day 30, was lower in the peripheral retina and intermediate in the avascular region of the myelinated streak. The observed localization of MHCII+ cells in relation to blood vessels and location-dependent differences in MHCII expression point to the possibility that these cells may be distributed strategically within the retina to provide multiple lines of defence against immune challenge arriving via the retinal vasculature.
We have found photometric indications that Interacting Eclipsing Binaries of early to mid F spectral type (and possibly A) have strong magnetic activity which would arise from convective atmospheres. Light curve solutions and periodicity studies revealing spots, magnetic breaking and magnetic cycles are presented in XZ CMi, V965 Cyg and V963 Cyg.
Approximations to the scattering of linear surface gravity waves on water of varying quiescent depth are investigated by means of a variational approach. Previous authors have used wave modes associated with the constant depth case to approximate the velocity potential, leading to a system of coupled differential equations. Here it is shown that a transformation of the dependent variables results in a much simplified differential equation system which in turn leads to a new multi-mode ‘mild-slope’ approximation. Further, the effect of adding a bed mode is examined and clarified. A systematic analytic method is presented for evaluating inner products that arise and numerical experiments for two-dimensional scattering are used to examine the performance of the new approximations.