Looking and search measures of object knowledge in preschool children.

The same preschoolers were tested on an observation task and a search task involving the invisible displacement of an object. In the observation task, children watched an object roll behind a screen from which protruded the top of a solid wall. Analyses revealed significantly longer looking to impossible than to possible outcomes in all children. In search, the child was allowed to retrieve the rolled object. Most 3-year-olds but significantly fewer 2.5-year-olds completed the search successfully. An unexpected sex difference was found, with boys outperforming girls. Search performance was not associated with observation measures. The findings indicate that children visually discriminate violations of solidity but that this sensitivity is not associated with successful search performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cardiorespiratory and spinal cord blood flow effects of intrathecal neostigmine methylsulfate, clonidine, and their combination in sheep

BACKGROUND: Intrathecal neostigmine may produce analgesia by itself and may enhance analgesia from spinal clonidine. Before clinical trials, the spinal cord blood flow effects of these drugs alone and in combination should be examined in animals. METHODS: Conscious, nonpregnant ewes with indwelling vascular and thoracic spinal catheters received intrathecal injection of 0.2 or 2 mg neostigmine, 0.2 mg clonidine, or 2 mg neostigmine plus 0.2 mg clonidine. Mean systemic and pulmonary arterial and central venous pressures, heart rate, and cardiac output were monitored, arterial blood was sampled for blood gas tensions and pH, and spinal cord blood flow was determined by colored microsphere injection before and at 15, 60, and 240 min after spinal study drug injection. RESULTS: Neostigmine alone did not affect cardiorespiratory variables or spinal cord blood flow. Intrathecal clonidine alone decreased systemic arterial and central venous pressures, whereas these effects were not observed with addition of neostigmine. Clonidine or neostigmine alone or the combination of clonidine and neostigmine did not affect spinal cord blood flow. CONCLUSIONS: Intrathecal neostigmine alone or in combination with clonidine does not reduce spinal cord blood flow, an important preclinical toxicity issue. These results provide additional support for initial clinical trials of intrathecal neostigmine for analgesia.     

Student and preceptor perceptions of factors in a successful learning partnership

Thirty-two registered nurse preceptors and 42 senior undergraduate nursing students completed a survey ranking factors related to both participants in the clinical learning partnership. Mann-Whitney U-Wilcoxon Rank Sum W tests showed statistically significant differences in the ranking of four factors (the ability to give and receive criticism, knowledge of the preceptoring process, clinical competence, and compatibility) that contribute to successful learning partnerships. Nurse educators and professional nurses should acknowledge these perceptual differences and include these in student and preceptor orientation programs to promote a positive teaching and learning partnership.     

What students say about learning and teaching in longitudinal ambulatory primary care clerkships: a multi-institutional study

The past year has seen a coming-of-age in DNA enzyme research. Far from being laboratory curiosities, the activities of new DNA enzymes have broadened the known catalytic repertoire of nucleic acid enzymes, provided valuable insights into different mechanistic possibilities open to nucleic acid catalysts, and explored the importance for catalysis of native functionalities within DNA and RNA, as well as of a diversity of extrinsic cofactors. Thus, the first amino acid cofactor-utilizing DNA enzyme has been described, as well as DNA enzymes that cleave RNA without the assistance of any external cofactor. On the practical side, the most efficient RNA-cleaving nucleic acid enzyme described to date is a DNA enzyme.     

Pre-slaughter injection of sodium ascorbate as a method of inhibiting metmyoglobin formation in fresh beef

Colour deterioration, measured by metmyoglobin accumulation, in four muscles, from 10 beef animals, intravenously injected pre-slaughter with sodium ascorbate, is compared with similar muscles from 10 control animals, at 0 °C and 5 °C. Meat from sodium ascorbate treated animals has significantly better colour stability, particularly M. psoas major and M. gluteus medius at the higher storage temperature.     

Comparison of chemical composition of meat determined at eight laboratories

Sixteen minced samples of lean beef M. semimembranosus and M. gracilis were analysed for nitrogen, fat, moisture, collagen, ash and pH using recommended procedures in eight European Communitie' (EC) meat research laboratories. Differences between replicate determinations within laboratories were often larger than suggested in reference methods although they were smaller than the differences between laboratories. Moisture and pH were determined most consistently, collagen least consistently.     

Influence of reading level difficulty on the disfluencies of normal children

This study assessed the effect of increasing the difficulty of reading material on the frequency and type of disfluency in the oral reading of normally fluent elementary school children. Eighty children participated in the study. Ten boys and 10 girls each, from Grades 3, 4, 5, and 6, read five 200-word passages, corresponding to one grade below their school placement, the grade of their school placement, and one, two, and three grades above their school placement. Results indicated a significant increase in total moments of disfluency and four specific types of disfluency as the difficulty of reading material increased. The data revealed a tendency for "stuttering" disfluencies to increase more in frequency than "normal" nonfluencies. Results are discussed with respect to theoretical and experimental implications.     

Mucocutaneous reactions to antineoplastic agents

Mucocutaneous reaction patterns in patients receiving cancer therapy are not only variable, but in many instances identical patterns are produced by different pathologic mechanisms. For example, patients with leukemia or lymphoma may present with nodular skin lesions that may represent malignant infiltration, septic emboli, vasculitis, or a drug eruption. The most banal skin eruption may signal an impending or ongoing catastrophe. If one is able to make some clinical evaluation regarding the likelihood of a drug being responsible for the mucocutaneous eruption, it may help avoid further clinical or laboratory investigation and patient discomfort. Unfortunately, only a few antineoplastic agents have "characteristic" skin manifestations. If, however, these are kept in mind they may be helpful in the diffential diagnosis of mucocutaneous eruptions occurring in patients treated with cancer chemotherapeutic agents.     

An evaluation of freezing as a preservation technique for analyzing dissolved organic C, N and P in surface water samples

Techniques for preserving surface water samples are recently in demand because of the increased interest in quantifying dissolved organic matter (DOM) in surface waters and the frequent collection of samples in remote locations. Freezing is a common technique employed by many researchers for preserving surface water samples; however, there has been little evaluation of the effects of freezing on DOM concentrations. Ten streams were sampled in southeast Alaska with a range of dissolved organic carbon (DOC) concentrations (1.5 to 39 mg C L(-1)) to evaluate the influence of freezing (flash and standard freeze) and filter pore size (0.2 and 0.7 mum nominal pore size) on dissolved organic C, N and P concentrations. We report a significant decrease in DOC (p<0.005) and total dissolved P (p<0.005) concentrations when streamwater samples were frozen, whereas concentrations of dissolved organic N did not significantly decrease after freezing (p=0.06). We further show that when surface water samples were frozen, there was a decrease in the specific ultraviolet absorbance (SUVA) of DOC that is particularly evident with high concentrations of DOC. This finding suggests that spectroscopic properties of DOC have the potential to be used as indicators of whether surface water samples can be frozen. Our results lead us to recommend that surface water samples with high DOC concentrations (>5 mg C L(-1)) and/or samples with high SUVA values (>3.5-4 L mg-C(-1) m(-1)) should be analyzed immediately and not frozen.