Ethnopsychologies: Reply to Wellman (1998) and Gauvain (1998).

Four main issues are considered in response to H. M. Wellman (see record 1997-42548-002) and M. Gauvain (see record 1997-42548-003): the relevance of adult data, the source of evidence for theories of mind, explaining development, and the proper focus of theory of mind research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Synthesis of 6-fatty acid esters ofl-ascorbic acid

High yields (85%) of 6-fatty acid esters ofl-ascorbic acid were obtained by reactingl-ascorbic acid (1.2 M) in 98~99% sulfuric acid for 36 hr at 20 C with 36% excess fatty acid. In concentrated sulfuric acid,l-ascorbic acid was rapidly sulfated to produce mainlyl-ascorbyl 6-sulfate, which slowly reacted with fatty acid to producel-ascorbyl 6-acylate.     

Young children's understanding of different mental states.

There is considerable evidence in the recent literature on children's understanding of the mind that young children have difficulty understanding false beliefs. Even when presented very strong evidence that a person's belief conflicts with the reality to which it refers, they tend to assume that it coincides with reality. Two studies tested the extent to which 3-yr-olds make this same mistake with other mental states. Results show that children of this age understand that desires can differ from reality before they understand that beliefs can, even when the exact same tasks are used to assess each understanding. Findings also indicate that young children understand pretense in this regard somewhat later than desire but earlier than belief and dream, particularly when the pretense is supported by actions. Three explanations for the results are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Mothers' Behavior Modifications During Pretense and Their Possible Signal Value for Toddlers.

An important issue for understanding early cognition is why very young children's real-world representations do not get confused by pretense events. One possible source of information for children is the pretender's behaviors. Pretender behaviors may vary systematically across real and pretend scenarios, perhaps signaling to toddlers to interpret certain events as not real. Pretender behaviors were examined in 2 experiments in which mothers were asked both to pretend to have a snack and really to have a snack with their 18-month-olds. Episodes were analyzed for condition differences in verbal and nonverbal behaviors, including smiling, looking, laughter, and functional movements. Reliable differences were found across conditions for several variables. In a 3rd experiment, children's apparent understanding of pretense in relation to their mothers' behaviors was examined, and significant associations were found with some of the mothers' behavioral changes but not others. This work provides a first inroad into the issue of how children learn to interpret pretense acts as pretense. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Wanting to be it: children's understanding of intentions underlying pretense

How children understand the mental state of pretense has recently become an active area of inquiry, with some research suggesting that young children do not understand that pretending is based on mentally representing some alternate state of affairs. Because intention is thought to be understood earlier than mental representation generally, these experiments tested whether children understand pretense intentions at an earlier age than they understand pretense mental representations. Children were told about a character's intentions and conflicting actions, and were asked about the character's pretense. Across 5 experiments, children did not demonstrate appreciation that intention is crucial to pretense. Various methodological factors that might have compromised the results were examined, but to no effect.     

Effect of temperature on threshold values for citric acid, malic acid and quinine sulphate--energy of activation and extreme-value determination

The thresholds for citric acid, malic acid and quinine sulphate were determined at three temperatures to ascertain the effect of temperature on taste sensitivity. Temperature had an effect, but judge-substance interactions were just as important. The energy of activation for taste response usually was in the range 5–20 kcal. The data suggest that extreme-value methods should be useful in predicting the percentage of individuals whose thresholds will be below some certain level.     

Glycosylation and expanded utility of a modified whey protein ingredient via carbohydrate conjugation at low pH

Whey protein, at one time considered a by-product of the cheese-making process, is now commonly used in foods for its thickening and emulsifying properties. Currently, approximately 30% of these proteinaceous resources remain under-utilized. Previously, an acidified, thermally treated whey protein concentrate (mWPC) was developed to produce a cold-set thickening ingredient. Mass spectroscopy revealed an approximate 2.5-fold decrease in the lactosylation of β-lactoglobulin in mWPC starting materials compared with commercial whey protein concentrates, manufactured at a higher pH. Potentially, this should increase the number of reactive sites that remain available for carbohydrate attachment. With this study, the formation of glycoprotein complexes was demonstrated between the mWPC ingredient and lactose, naturally occurring in mWPC powders, or between mWPC protein components with dextran (35 to 45 and 100 to 200 kDa) materials at low pH. In fact, additional dry heating of mWPC powders showed a 3-fold increase in the amount of lactosylated β-lactoglobulin. Evidence of Maillard reactivity was suggested using colorimetry, o-phthaldialdehyde assays, and sodium dodecyl sulfate PAGE followed by glycoprotein staining. Resultant glycoprotein dispersions exhibited altered functionality, in which case steady shear and small amplitude oscillatory rheology parameters were shown to be dependent on the specific reducing sugar present. Furthermore, the emulsion stability of mWPC-dextran fractions was 2 to 3 times greater than either mWPC or commercial WPC dispersions based on creaming index values. The water-holding capacity of all test samples decreased with additional heating steps; however, mWPC-dextran powders still retained nearly 6 times their weight of water. Scanning electron microscopy revealed that mWPC-dextran conjugates formed a porous network that differed significantly from the dense network observed with mWPC samples. This porosity likely affected both the rheological and water-binding properties of mWPC-dextran complexes. Taken together, these results suggest that the functionality of mWPC ingredients can be enhanced by conjugation with carbohydrate materials at low pH, especially with regard to improving the emulsifying attributes.     

Continuous cell introduction for the analysis of individual cells by capillary electrophoresis

Instrumentation for high-throughput analysis of single cells by capillary electrophoresis is described. A flow-based interface that uses electroosmotic flow (EOF) provides continuous injection of intact cells through an introduction capillary into a cell lysis junction and migration of the resulting cell lysate through a separation capillary for analysis. Specifically, two capillaries were coupled together with 5-mm-long Teflon tubing to create a approximately 5-microm gap, and the junction was immersed in a buffer reservoir. High voltage was applied across both capillaries so that cells were continuously pumped into the first capillary by EOF. Individual cells were lysed on-column at the junction without detergents, presumably owing to mechanical disruption caused by a dramatic change in flow properties at the gap. After each cell was lysed at the junction, the major proteins hemoglobin and carbonic anhydrase were separated by capillary electrophoresis and the resultant analyte zones were detected by laser-induced native fluorescence using 275-nm excitation. The detection limits of hemoglobin and carbonic anhydrase were 37 and 1.6 amol, respectively, which correlate well with the literature. The instrumentation was evaluated with intact red blood cells. The averaged time for complete analysis (i.e., continuous injection, lysis, separation, and detection) of one human erythrocyte was less than 4 min with this capillary-based setup. Moreover, this instrumentation simplifies the introduction of individual, intact cells without the use of a microscope.     

Ab-initio calculations of the hydrogen–uranium system: Surface phenomena, absorption, transport and trapping

Density functional theory was applied to the initial steps of uranium hydriding: surface phenomena, absorption, bulk transport and trapping. H adsorbs exothermically to the (0 0 1) surface, yet H absorption into the bulk is endothermic, with off-center octahedral absorption having the lowest absorption energy of 0.39 eV, relative to molecular H₂. H absorption in interstitial sites causes a local softening of the bulk modulus. Diffusion of H in unstrained α-U has a barrier of 0.6 eV. The energy of H absorption adjacent to the chemical impurities C, S, Si was lowered by an amount proportional to the size of the impurity atom, and the resulting lattice strain Si > S > C. Thus, impurities may promote hydriding by providing surfaces or prestrained zones for H uptake.