The incidence of error in young children's Wh-questions.

Many current generativist theorists suggest that young children possess the grammatical principles of inversion required for question formation but make errors because they find it difficult to learn language-specific rules about how inversion applies. The present study analyzed longitudinal spontaneous sampled data from twelve 2-3-year-old English speaking children and the intensive diary data of 1 child (age 2;7 [years;months] to 2;11) in order to test some of these theories. The results indicated significantly different rates of error use across different auxiliaries. In particular, error rates differed across 2 forms of the same auxiliary subtype (e.g., auxiliary is vs. are), and auxiliary DO and modal auxiliaries attracted significantly higher rates of errors of inversion than other auxiliaries. The authors concluded that current generativist theories might have problems explaining the patterning of errors seen in children's questions, which might be more consistent with a constructivist account of development. However, constructivists need to devise more precise predictions in order to fully explain the acquisition of questions.     

The topical organization of the afferents to the caudatoputamen of the rat. A horseradish peroxidase study

The aim of the present study was to assess (1) whether the various brain areas known to send projections to the neostriatum of the rat (neocortex, thalamus, substantia nigra, ventral tegmental area and dorsal raphe nucleus) project to all parts of this structure, and (2) whether the subcortical projections show a topical organization. For these purposes, small deposits of horseradish peroxidase were delivered by iontophoretic application, so that the whole extent of the caudatoputamen could be covered in a total of 40 rats.Labeled cortical cells were present mainly in lamina V, and showed a roughly topographical organization. Small numbers of labelled cells were observed in the basal nucleus of the amygdala after injections into the dorsal and central parts of the caudatoputamen. The cells of origin of thalamic afferents to the neostriatum were found not only in the intralaminar nuclei, but also in various other anterior, ‘midline’, and posterior nuclei (e.g. the medial part of the medial geniculate body). In the thalamostriatal projection a topical organization was demonstrated, consisting of oblique thalamic zones, which cross the borders of several thalamic nuclei and project to different parts of the neostriatum. In the substantia nigra and ventral tegmental area many retrogradely labelled cells were present. This nigrostriatal projection appears to be organized along an oblique longitudinal neostriatal axis. The nucleus raphes dorsalis was labelled most abundantly after caudal and ventrolateral injections into the caudatoputamen.It is concluded that, despite the homogeneous cytoarchitectonic structure of the caudatoputamen in the rat, this brain area is rather heterogeneous as regards its afferent connections. In fact each part of the neostriatum receives a specific and unique combination of afferents. The main changes in the input of the neostriatum appear to occur along an oblique longitudinal axis, from the most rostromedial and dorsal part to the caudolateral and ventral part. Such a topographical organization suggests that the neostriatum is likely to be involved in very complex integrative functions involving several brain areas.     

Influence of the punch diameter and curvature on the yield pressure of MCC-compacts during Heckel analysis.

The volume reduction behaviour of powders has been quantified by means of the 'in-die' yield pressure (YP) using Heckel analysis. However, because different YPs are reported for the same material, the experimental conditions influencing this material-constant were investigated. Silicified microcrystalline cellulose was compressed into flat-faced and convex tablets using a compaction simulator instrumented with load and displacement transducers. During compression, upper and lower punch force and displacement data were recorded and corrected for punch deformation. A symmetrical triangle wave compression profile was used and the instantaneous punch velocity was kept constant (5mm/s). Individual tablet height and weight were used for Heckel analysis. The influence of the 'effective compression pressure' (P(EFF)) (ranging from 10 to 350 MPa), punch diameter (PD) (4, 9.5 and 12 mm) and filling depth (FD) (4.5, 7.5 and 10.5mm) on YP was statistically evaluated using Response Surface Modelling software. A quadratic surface response equation, describing the relationship between P(EFF), PD, FD and YP, was proposed for concave (Adj R(2): 0.8424; S.D.: 14.60 MPa) and flat-faced (Adj R(2): 0.8409; S.D.: 4.49 MPa) punches. YP and tensile strength were mainly determined by P(EFF), irrespective of punch curvature. FD and PD had only a minor influence on the YP, although more pronounced for the concave punches. The method used resulted in reproducible P(EFF) and tensile strength values and the flat-faced tablets showed less weight variation. Flat-faced punches are preferred over punches with a concave surface when investigating the volume reduction behaviour of a powder by means of Heckel analysis and the experimental parameters should be reported.     

How to improve screening in first-degree relatives of patients with premature coronary heart disease.

BACKGROUND: Guidelines on the prevention of cardiovascular disease recommend screening in close relatives of patients with premature coronary heart disease (CHD). This family history puts them at increased risk for CHD, independent of other major risk factors, but screening for CHD risk factors in these relatives is not widely practiced in Europe. This demonstration project examined how to improve screening of close relatives of patients with premature CHD in daily practice. METHODS: A controlled study design was used. Four hospitals were compared in a pre-test as to the actual screening of relatives of patients with premature CHD. Then they were arranged in pairs and randomly assigned to the Usual care (U) or Intervention group (I). An information and health education program--involving patients, relatives and family doctors--was developed in I to improve screening by the family doctor. RESULTS: The pre-test confirmed that screening of relatives of patients with premature CHD is poorly practiced in the four regions; no significant differences between I and U were observed. The screening of relatives during the study period reached 63.9% in I compared to 25.4% in U. This difference between I and U was present in siblings and offspring. The cardiovascular risk profile of the relatives of I was not optimal and needed improvement. CONCLUSION: Screening of first-degree relatives of patients with premature CHD can be significantly improved through a health education program. This is the first and necessary step to improve the management of risk factors in these people, who are at increased risk for CHD.     

Health economic evaluation of controlled and maintained physical exercise in the prevention of cardiovascular and other prosperity diseases.

OBJECTIVES: Several studies and reports support the health benefits of frequent physical exercise, on the condition that this exercise is controlled and maintained. Given the scarce resources that can be spent on health and health care, the objective of this study was to evaluate the long-term health and economic outcomes of controlled and maintained physical exercise in a fitness setting. METHODS: A 25-year Markov model with a 12-month cycle-length and states representing diabetes, coronary heart disease, stroke, colon cancer and breast cancer was developed to predict cumulative costs and QALYs (quality adjusted life years) for three defined population cohorts, of different risk levels. Physical exercise was thereby compared with no intervention. Reduced risks associated with physical exercise, cost of diseases and loss of quality of life in case of disease were obtained from published literature. Costs were taken from a societal perspective; Belgium was selected as the setting. One way and probabilistic sensitivity analyses were carried out. RESULTS: For each of the cohorts, physical exercise is predicted to increase the QALYs and to offset a large part of the initial investment. The cost per QALY varies from 2000 to 15,000 Euro per QALY depending on the risk levels, which is better compared with a majority of secondary preventions that are currently publicly financed. CONCLUSION: Controlled and maintained physical exercise is projected to be cost-effective, which is likely to be explained by its simultaneous effect on several diseases and the associated weight loss, which affects quality of life positively.     

Effect of build orientation on the manufacturing process and the properties of stereolithographic dental ceramics for crown frameworks

Statement of problemStereolithography (SLA) ceramic crown frameworks are suitable for clinical use, but the impact of SLA build orientation has not been identified.PurposeThe purpose of this in vitro study was to investigate the effect of 3 build orientations on the physical and mechanical properties and the microstructure of SLA alumina dental ceramics.Material and methodsThe physical and mechanical properties and microstructures of 3 different oriented SLA alumina ceramics (ZX, ZY, and XY) were evaluated by visual observation, hydrostatic weighing (n=10/group), Weibull analyses (n=30/group), scanning electron microscopy, 3-point flexural strength (n=30/group), fracture toughness (indentation, single-edge-V-notched-beam) (n=4/group), and Vickers hardness (n=15/group) testing. The hydrostatic weighing, 3-point flexural strength, fracture toughness, and Vickers hardness testing data were statistically analyzed (α=.05).ResultsThe minimum resting period of slurries between the polymerization of 2 layers was shorter for the ZY- and ZX-oriented specimens and increased with the layer surface. The density and Vickers hardness of the SLA-manufactured specimens were similar for all groups (P>.05). The 95% confidence intervals of the Weibull moduli of the ZX- and ZY-oriented specimens were higher than that of the XY-oriented specimens, with no overlap fraction. The ZY-oriented specimens displayed significantly higher 3-point flexural strength (P<.05) and fracture toughness as evaluated by the single-edge-V-notched-beam method than the ZX-oriented specimens (P<.05). They also displayed significantly higher 3-point flexural strength than the XY-oriented specimens (P<.05). The microstructural analysis showed that the texturing was heterogeneous and that the major axis of the large grains of alumina ran parallel to the orientation of the layers.ConclusionsThe ZY orientation produced a reliable dental ceramic by SLA, with the shortest general manufacturing time and the highest mechanical strength when the layers were perpendicular to the test load surface.