The Relation Between Television Exposure and Theory of Mind Among Preschoolers

This study explored the relation between preschoolers' television exposure and one important indicator of cognitive processing called theory of mind (ToM). A total of 107 preschoolers and their parents provided data on the preschoolers' television exposure (including both intentional viewing and exposure via background television), parent–child discussion of television, and preschoolers' ToM. The results indicated that preschoolers who were exposed to more background television and who had a television in their bedroom performed more poorly on ToM assessments compared with other children. Parent–child discussion of television was positively related to ToM performance, however. These results have implications for how we understand the effects of television on preschoolers.     

3D Simulation of Nano-Imprint Lithography

A proof of concept study of the feasibility of fully three-dimensional (3D) time-dependent simulation of nano-imprint lithography of polymer melt, where the polymer is treated as a structured liquid, has been presented. Considering the flow physics of the polymer as a structured liquid, we have followed the line initiated by de Gennes, using a Molecular Stress Function model of the Doi and Edwards type. We have used a 3D Lagrangian Galerkin finite element methods implemented on a parallel computer architecture. In a Lagrangian techniques, the node point follows the particle movement, allowing for the movement of free surfaces or interfaces. We have extended the method to handle the dynamic movement of the contact line between the polymer melt and stamp during mold filling.     

Milk quality on Danish farms with automatic milking systems

The bulk-milk quality of 98 Danish farms with automatic milking systems was analyzed from 1 yr before introduction of automatic milking until 1 yr after. Bulk-milk total bacterial count, spores of anaerobes, somatic cell count (SCC), and freezing point increased when automatic milking was introduced and the frequency of milk-quality failures almost doubled. Milk-quality failures were most frequent in the first 3 mo after the start of automatic milking. The increase in spores of anaerobes indicated that the increase in total bacterial count originated partly from contamination of milk from the teat surface and partly from lack of cleaning of the milking equipment or cooling of the milk. The increase in bulk-milk SCC indicated that milk from clinically infected cows and cows with high cell counts was not diverted to the same degree, milking automatically rather than milking conventionally. A self-monitoring program including survey of the bulk-milk quality was established to help farmers in the transition period going from conventional to automatic milking. The program was introduced on 84 farms. Farms on the self-monitoring program reduced bulk-milk cell count. Application of the program did not reduce the frequency of high total bacterial counts and freezing points of the bulk milk to the level of conventional milking. However, the program reduced the overall frequency of milk-quality failures.     

Atomic force microscopy study of the interaction of Fusarium solani pisi cutinase with lipid surfaces

We present an atomic force microscopy (AFM) study of a supported triacylglyceride multilayer phase and its interaction with lipolytic enzyme cutinase from Fusarium solani pisi. The multilayer triacylglyceride phase of coconut oil showed a rippled surface structure in the AFM images. Upon enzymatic degradation of the triacylglyceride phase, the ripple structure vanished rapidly. The apparent catalytic rate constants could be estimated based on the AFM image information. Interestingly, in one sample we observed what we interpret as a recurrent structural collapse of the cavity dug out by the protein. We interpret the cavities seen in the AFM images as molten surfaces or surface holes filled with liquidified phase containing product molecules, which appear transparent during the image recording.     

Metal ion and guanine nucleotide modulations of agonist interaction in G-protein-coupled serotonin1A receptors from bovine hippocampus

1. The serotonin type 1A (5-HT1A) receptors are members of a superfamily of seven transmembrane domain receptors that couple to GTP-binding regulatory proteins (G-proteins). We have studied the modulation of agonist binding to 5-HT1A receptors from bovine hippocampus by metal ions and guanine nucleotide. 2. Bovine hippocampal membranes containing the 5-HT1A receptor were isolated. These membranes exhibited high-affinity binding sites for the specific agonist [3H]OH-DPAT. 3. The agonist binding is inhibited by monovalent cations Na+, K+, and Li+ in a concentration-dependent manner. Divalent cations such as Ca2+, Mg2+, and Mn2+, on the other hand, show more complex behavior and induce enhancement of agonist binding up to a certain concentration. The effect of the metal ions on agonist binding is strongly modulated in the presence of GTP-gamma-S, a nonhydrolyzable analogue of GTP, indicating that these receptors are coupled to G-proteins. 4. To gain further insight into the mechanisms of agonist binding to bovine hippocampal 5-HT1A receptors under these conditions, the binding affinities and binding sites have been analyzed by Scatchard analysis of saturation binding data. Our results are relevant to ongoing analyses of the overall regulation of receptor activity for G-protein-coupled seven transmembrane domain receptors.     

Female-to-male sex pheromones of low volatility in the Asian elephant,Elephas maximus

In their natural ecosystems, the sexes of Asian elephants,Elephas maximus, live separately. For several weeks prior to ovulation, the urine and cervical mucus of female Asian elephants contain extractable chemical agents of low volatility that elicit a high frequency of flehmen responses from bull elephants as an integral part of mating. Subsequent to flehmen responses, male sexual arousal occurs and, if the female is available, mating results. During the course of our project to determine the agent(s) and describe the responses associated with female to male sexual communication, we have identified an unusual compound. This compound, apparently the sole component of the active fraction, was identified by mass, proton nuclear magnetic resonance, ultraviolet/visible, and infrared spectrometries as indolo-[2,1-b] quinazoline-6,12-dione (tryptanthrine). Exhaustive and repetitive bioassays established that pure authentic (synthetic) tryptanthrine was not the compound responsible for the bioresponse. Rather a coeluting minor component, also of low volatility, elicited the male bioresponse.     

The effects of biological and social risk factors on special education placement: birth weight and maternal education as an example

The characteristics of objective lenses and Ca2+-sensitive probes were examined for imaging with a two-photon laser-scanning microscope (TP-LSM). The brightness of the images of beads taken by different objectives greatly varied and depended predominantly on their numerical aperture (NA) and less on transmittance and chirping effects. Lateral and axial resolutions, dx and dz, defined as the half decay length of fluorescence intensity of the image of a spherical bead (0.3 m) were 0.12 and 0.42 microm (objective; 40x/0.75). They are far better than those of confocal microscopes (0.3 and 1.5 microm, respectively) measured similarly (Kuba et al., 1994). dx linearly increased with an increase in 1/NA, while dz linearly increased with an increase in n/(NA)2 (n, refractive index) except for an objective of large NA (1.3). The coverslip compensation of objective lenses greatly affected the shape of the X-Z scanned images of 5.0 microm beads as well as resolutions, indicating a large effect of spherical aberration. Two-photon excitation spectra of Ca2+-sensitive fluorescent probes, indo-1, fura-2 and Oregon Green BAPTA-1, lied in a wavelength range shorter than twice that activated by one-photon absorption, while emission spectra were unchanged. Three-dimensional images of a cultured hippocampal neurone loaded with Oregon Green BAPTA-1 showed fine structures of spines, dendrites and axons, while imaging with FM1-43 localized presynaptic boutons and demonstrated synaptic vesicle turnover. Dyes bleached little during the recording of 100 sectioned images. These characteristics of TP-LSM as well as its ability to image deeper tissues provide excellent means to study dynamic, spatial changes in intracellular substances and structures. To achieve the good performance of a TP-LSM, however, the relevant usage of appropriate objectives and fluorescent probes are required.     

The effect of compressive loading on proteoglycan turnover in cultured fetal tendon

A fibrocartilaginous tissue develops in tendon at the point where the tendon wraps under bone and is subjected to transverse compressive loading in addition to tension. This tissue is characterized by a high level of large proteoglycan (aggrecan), which could accumulate because of increased synthesis, diminished turnover, or both. To examine the effect of loading on proteoglycan turnover segments of fetal tendon in sterile culture were subjected to cyclic, uniaxial compression loading to 30% of initial thickness once every 6 sec. for 72 h, and then allowed to incorporate 35S-sulfate for 12 h. The rate of loss of newly-synthesized 35S-proteoglycans from tissue was determined during subsequent culture for up to 12 days, with or without continued loading. Proteoglycan was lost from fetal tendon segments rapidly during the first 3 days of culture and slowly thereafter. Loss of newly-synthesized proteoglycan from adult tendon fibrocartilage was linear, with a half life of 12 d. Segments of fetal tendon subjected to cyclic compression before labeling synthesized more proteoglycan. These segments lost a greater percent of labeled proteoglycan to medium during a subsequent 12-day culture period than matched segments that had not experienced loading. Analysis of medium and tissue proteoglycans by SDS polyacrylamide gel electrophoresis and sieve chromatography indicated that small proteoglycans (decorin and biglycan) were retained in both loaded and non-loaded tissue whereas large proteoglycans (migrating in the Vo of a Sepharose CL-4B column) were readily lost. It is concluded that the 3-day loading regimen did not diminish turnover of large proteoglycan. To the contrary, although synthesis of large proteoglycan was enhanced by the loading regimen, these proteoglycans were still rapidly lost from the fetal tissue.