Examining the dimensionality of effortful control in preschool children and its relation to academic and socioemotional indicators.

Effortful control (EC) is an important developmental construct, associated with socioemotional growth, academic performance, and psychopathology. EC is defined as the ability to execute goal-directed behavior to inhibit or delay a prepotent response in favor of a subdominant response. Extant research indicates that EC may be multidimensional. Confirmatory factor analysis with a sample of 234 preschoolers was used to determine if tasks designed to measure EC were best described by hot (affectively salient) and cool (affectively neutral) dimensions or by a single factor. Analyses revealed that EC is best described by a single factor, even when variance associated with children's language skills was removed. This EC factor was strongly related to measures of academic performance and significantly less related to measures of socioemotional development. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Release of fluorescent markers from phase‐separated gelatin‐maltodextrin hydrogels

Genipin‐crosslinked gelatin‐maltodextrin phase‐separated hydrogels consisting of gelatin‐continuous or bicontinuous microstructures were developed to regulate swelling and release behavior of four fluorescent markers of varying molecular weights [(fluorescein (332 Da) and FITC‐dextrans (FD) (4000–250,000 Da)]. Bicontinuous hydrogels showed significantly greater swelling than gelatin‐continuous hydrogels under all conditions (at pH 1.5 and 7.4 and three genipin/gelatin crosslinking ratios) (P < 0.05). With both microstructures, fluorescein showed the largest release rate and total release followed by FD 4000 Da, FD 40,000 Da, and FD 250,000 Da (P < 0.05). Marker molecular weight, pH, and crosslink ratio all affected the rate and amount of release. The mode of transport for the solvent and all markers was Fickian or slightly anomalous, with diffusional exponent (n) values ranging from 0.35 to 0.64. These results demonstrated that with the proper combination of crosslink density, solvent pH, and microstructure, hydrogels with a specified swelling behavior may be developed. This, coupled with a marker of appropriate size, can lead to controllable levels and rates of release. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Development of a microwave-assisted digestion method using ICP-OES to measure metals in gum deposits of internal combustion engines

The heterogeneous nature of gum samples obtained from the deposits of internal combustion engines is the main difficulty in accurate determination of their metal content. A microwave-assisted digestion method was implemented using factorial experimental design. The optimization of this procedure was carried out by first evaluating the effects of variables on the response (i.e., the residual carbon content or RCC). The variables of maximum heating power, heating time and nitric acid volume were studied. The RCC response was measured by inductively coupled plasma optical emission spectrometry (ICP-OES). The time of maximum heating power was essential to obtain a desired RCC. The surface response was constructed with optimal conditions presented at 6 min and heating power of 700 W. Amounts of aluminum (Al), calcium (Ca), copper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), nickel (Ni), lead (Pb) and zinc (Zn) were determined in 26 gum samples by ICP-OES. Ca, Fe, Mg and Zn were found at mg g⁻¹ levels in the samples, while Al, Cu, Mn, Ni and Pb were found at mg kg⁻¹ levels. Principal component analysis (PCA) was used to establish a correlation between the gum samples and the different metal contents. Three distinct groups were separated according to the characteristics of the collected samples.     

Paranoia and self-consciousness.

Presented, in Study 1, a new instrument designed to assess paranoid thought in college students, together with reliability and validity data. A single general factor accounted for a substantial portion of the variance in the full scale. Public self-consciousness was consistently and significantly correlated with the present measure of paranoia. In Study 2, both pretested paranoia and public self-consciousness were related to feelings of being watched (a classical manifestation of paranoia), although public self-consciousness had an effect only when there was a 2-way mirror present. In Study 3, self-attention, experimentally induced using a story construction task, again resulted in a heightened sense of being observed. Discussion focuses on paranoid cognition as characteristic of everyday thought and the implications of self-attention for social perception processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Detection of obstructive uropathy in the fetus: predictive value of sonographic measurements of renal pelvic diameter at various gestational ages

OBJECTIVE: The goal of our study was to analyze the fetal renal pelvic diameters measured sonographically at several gestational intervals in live-born neonates subsequently found to have either obstructive uropathy or normal kidneys. This information will improve the efficacy of sonography in the diagnosis of obstructive uropathy. SUBJECTS AND METHODS: From an ongoing prospective study assessing the significance of fetal renal pelvic diameters of 4 mm or more at obstetric sonography, the findings in 29 obstructed kidneys in 24 babies were compared with the findings in 380 kidneys from 233 infants who had no obstruction. Twenty-three infants had unilateral obstruction of the ureteropelvic junction, two had unilateral renal obstruction at the ureterovesical junction, one had posterior urethral valves and in addition had both kidneys obstructed because of obstruction at the ureterovesical junction, one kidney was obstructed because of megaloureter, and one kidney was obstructed because of obstruction in a duplex collecting system. Obstruction was identified on nephrostograms, excretory urograms, or radionuclide renograms. The sonographic findings were compared at three gestational age ranges: 16-23 weeks' gestation, 24-30 weeks' gestation, and 31-40 weeks' gestation. The progression of pelvic dilatation in both groups (12 obstructed and 86 unobstructed) was analyzed for the subset of kidneys examined in all three time periods. RESULTS: At 16-23 weeks' gestation, the difference in mean pelvic diameter between obstructed and unobstructed kidneys was not statistically significant, but the difference between obstructed and unobstructed groups at 24-30 weeks' and 31-40 weeks' gestation was significant (p < .001). Renal pelvic diameter showed a much greater rise in diameter through pregnancy in the obstructed group than in the unobstructed group (p < .0003). The sensitivity of the cutoff point of 4-mm renal pelvic diameter for detecting obstruction was 76% before 23 weeks' gestation, including kidneys with a marked decrease in function postnatally; the sensitivity of a 10-mm cutoff point at 16-23 weeks' gestation was 12%. The likelihood that a fetus had renal obstruction increased with increasing diameter of the fetal renal pelvis in all three time periods. CONCLUSION: Kidneys with significant obstruction postnatally may have no dilatation of the renal pelvis before 23 weeks' gestation. Most obstructed kidneys had pelvic diameters of less than 10 mm before 23 weeks' gestation. During pregnancy, renal pelvic diameter increases at a greater rate in kidneys that later are shown to be obstructed than in those that are not obstructed.     

A motor signal and "visual" size perception

Recent models of the visual system in primates suggest that the mechanisms underlying visual perception and visuomotor control are implemented in separate functional streams in the cerebral cortex. However, a little-studied perceptual illusion demonstrates that a motor-related signal representing arm position can contribute to the visual perception of size. The illusion consists of an illusory size change in an afterimage of the hand when the hand is moved towards or away from the subject. The motor signal necessary for the illusion could be specified by feedforward and/or feedback sources (i.e. efference copy and/or proprioception/kinesthesis). We investigated the nature of this signal by measuring the illusion's magnitude when subjects moved their own arm (active condition, feedforward and feedback information available), and when arm movement was under the control of the experimenter (passive condition, feedback information available). Active and passive movements produced equivalent illusory size changes in the afterimages. However, the illusion was not obtained when an after-image of subject's hand was obtained prior to movement of the other hand from a very similar location in space. This evidence shows that proprioceptive/kinesthetic feedback was sufficient to drive the illusion and suggests that a specific three-dimensional registration of proprioceptive input and the initial afterimage is necessary for the illusion to occur.