Determinants of young children's search strategies in a large-scale environment.

26 3–6 yr olds searched for an object after traveling a route along which the object was used and later discovered missing (critical events). Ss then recalled the order of locations along the traveled route (sequence recall) and the locations for critical events (event recall); they also drew a map of the search environment. The correlation between event recall and search scores was significant only for Ss with good sequence recall. Correlations between sequence recall and search scores were higher for Ss who placed locations on the route in drawing maps. It is concluded that the acquisition of route knowledge in the development of spatial representation determined the likelihood that inferences would be made. When inferences were made, the accuracy of memories for sequences and events further determined the accuracy of the inferred critical search area. (8 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hospices: Perspectives on the public policy debate.

The public policy debate on hospice care centers on the appropriate mix of medical and supportive services for terminal cancer patients and how such services should be paid for within existing insurance programs. Past decisions to change health care reimbursement that are applicable to the hospice debate are reviewed, the benefits and costs of hospice care are examined, and the role of research in the formulation of social policy is discussed. (36 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Practical stability test for finite elements with reduced integration

An easy to use stability test is presented for finite elements which are under- or selectively-integrated. This test is reminiscent of the patch test in that it must be applied only to one prototype element, and it is a sufficient test for the nonsingularity of the global coefficient matrix. The minimum number of integration points which can be used with each of several common one-, two- and three-dimensional elements for a variety of steady-state and time-dependent, scalar boundary value problems are given.     

NaCl thresholds in man: Thresholds for water taste or NaCl taste?

Notes that water is not tasteless to humans, but rather can produce any of the 4 basic taste qualities if it is preceded by adaptation to an appropriate substance. After adaptation to the NaCl in saliva, water tastes predominantly bitter. Results of detection threshold experiments with 9 male undergraduates and the author as Ss demonstrate that this bitter water taste can be confused with solute tastes so that some detection thresholds for NaCl may actually represent water thresholds instead. Water also appears to have a taste after adaptation to saliva in the rat. Just as with humans, some apparently low thresholds for NaCl detection in rat may be water-taste thresholds. The apparently high preference threshold for NaCl in rat may be a true NaCl threshold based on adaptation to saliva. (116 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age hardening in Cu-15Ni-8Sn alloy

Age hardening and accompanying phase transformations were studied in a Cu-15Ni-8Sn alloy using mechanical testing, X-ray diffraction and microscopy techniques on samples aged at 300 to 550°C. At 450°C and below, strengthening is accompanied by the formation of sideband peaks about the fundamental reflections corresponding to a modulated structure with A? 100Å. This structure is metastable and with further aging is displaced by a discontinuous (cellular) precipitation reaction which causes the yield strength to drop. A peak yield strength increment of ?450 MPa is achieved in samples aged at 350°C. Both the hardening and the discontinuous transformation growth rates are increased by extensive deformation prior to aging. Prior deformation decreases the time to peak strength but does not significantly affect the peak strength increment. The early stages of aging correlate well with a spinodal strengthening model proposed by Ditchek and Schwartz which considers squaring of the composition modulation wave.     

Differentiation of letterlike forms in prereading children.

To investigate the development of perceptual differentiation of writing, 45 nursery school and kindergarten children were asked to label graphic displays varying in features shared with Roman letters and with letter strings. Ss ranged in age from 36 to 77 mo and were divided into 3-, 4-, and 5-yr-old groups, with 15 children in each. Number of writing displays correctly labeled as writing was the dependent variable. Analyses were carried out for displays contrasting on the independent variables of linearity, multiplicity, and variety of letter strings and on degree of similarity to Roman letter units. Significant effects were found for all variables except multiplicity. Developmental patterns support E. J. Gibson's (1969) model of increasing differentiation. Inferences are made about the self-teaching potential for early reading instruction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Refuse Decomposition in the Presence and Absence of Leachate Recirculation

A side by side comparison of two 8,000 metric ton test cells was performed to evaluate the effects of leachate recirculation on refuse decomposition at Yolo County, CA. After about 3 years of operation, refuse was excavated in three borings from the enhanced cell (E1, E2, and E3) and two borings from the control cell (C1 and C2). Refuse moisture content data show that leachate recirculation resulted in an increase in refuse moisture content, but also show that the refuse in the enhanced cell was not uniformly wet. The average moisture content in E1, E2, and E3 was 38.8, 31.7, and 34.8%, respectively, while the average moisture content in C1 and C2 was 14.6 and 19.2%, respectively. Leachate recirculation resulted in both higher methane yields, (63.1 versus 27.9 L CH4/wet-kg over 1231 days) and increased settlement (15.5% versus 3% of the waste thickness). The extent of decomposition of excavated refuse samples was determined by the biochemical methane potential (BMP) and the ratio of cellulose plus hemicellulose to lignin [(C+H)/Li]. Solids analyses showed the average BMP in the enhanced and control cells to be 24.0 and 30.9 mL CH4/dry-g, respectively. The corresponding (C+H)/Li ratios were 1.09 and 1.44, respectively. These data correlate well with the increased methane production in the enhanced cell. Thus laboratory and field data show more decomposition in the enhanced cell relative to the control cell. The refuse sampling program conducted for the Yolo County test cells, in concert with data on settlement, methane production, and the volume of liquid actually recycled, represents perhaps the most complete set of data available to date on a field-scale leachate recirculation landfill.     

Dynamic Measurements of In-Place Steel Floors to Assess Vibration Performance

The research presented in this paper resolves several measurement issues pertaining to the experimental modal analysis of lightweight steel floor systems. This investigation represents a first step toward collecting more extensive data on the dynamic behavior of steel floor systems. These data can then be used to improve design and analysis procedures for assessing the vibration serviceability of a floor system before construction. Some of the issues investigated herein are the selection considerations for the data acquisition system and transducers, the appropriate type and placement of excitation, and fast Fourier transform processing considerations.     

Wavelet-based method for noise characterization and rejection in high-performance liquid chromatography coupled to mass spectrometry

We present a new method for rejecting noise from HPLC-MS data sets. The algorithm reveals peptides at low concentrations by minimizing both the chemical and the random noise. The goal is reached through a systematic approach to characterize and remove the background. The data are represented as two-dimensional maps, in order to optimally exploit the complementary dimensions of separation of the peptides offered by the LC-MS technique. The virtual chromatograms, reconstructed from the spectrographic data, have proved to be more suitable to characterize the noise than the raw mass spectra. By means of wavelet analysis, it was possible to access both the chemical and the random noise, at different scales of the decomposition. The novel approach has proved to efficiently distinguish signal from noise and to selectively reject the background while preserving low-abundance peptides.     

Investigation into the mechanism by which cyclodextrins influence transdermal drug delivery

The objective of this study was to investigate the mechanism by which hydroxypropyl-beta-cyclodextrin (HPCD) increases transdermal permeation. Hairless mouse skin was pretreated with HPCD solutions for up to 4 h. After removing the HPCD, corticosteroid-containing suspensions were applied and the transdermal flux and skin accumulation of two model drugs were investigated. After pretreatment, changes to the stratum corneum endothermic melting transitions were determined as an indication of HPCD-induced lipid disorganization. Results demonstrated that HPCD pretreatment had no significant effect on the transdermal permeation or skin accumulation of the model corticosteroids. These findings suggest that HPCD functions to enhance the apparent solubility of the drug in the formulation, thus increasing transdermal permeation rather than extracting lipids from the skin.