Affective predictors of preschoolers' aggression and peer acceptance: Direct and indirect effects.

Observational assessments were made of 51 preschoolers' (mean age?=?53.25 months) peer aggression and emotional displays outside of (baseline) and during aggressive interactions, and their emotion knowledge and peer acceptance were also assessed. Results indicated that the connections between children's affective dispositions and their aggression and peer acceptance varied as a function of both the emotion context (baseline vs. aggression related) and the particular emotion involved (happiness vs anger). Emotion knowledge and affective dispositions overlapped little with each other, and both made independent contributions to peer acceptance and aggression. Mediation analyses revealed, however, that the significant connections between children's emotional dispositions and knowledge and their peer acceptance were mostly mediated by aggression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Empathy and responsibility in the motivation of children's helping.

To investigate affective and dispositional factors in the motivation of children's helping, 60 children ranging from preschool to sixth grade were observed in laboratory distress incidents involving, as potential recipients of aid, a kitten, an adult experimenter, and a mother with an infant. Positive, negative, and neutral affect expressions were observed in two of the three distress incidents, and prosocial dispositions were assessed through children's attributions regarding the motives and feelings of characters in eight stories involving persons in distress. Results indicated that helping tended to be positively correlated with positive affect and negatively correlated with negative and neutral affect. Further evidence suggested that these correlations were primarily attributable to positive affects associated with helping itself rather than to affects experienced in witnessing the other's distress. Among story attributions, attributions of guilt were strongly and consistently related to helping and affect expression in the total sample and across grade groupings. Attributions of empathy and altruism were also related to helping, but only in the total sample. These results are interpreted as suggesting that it may not be empathic arousal alone that is most important for the motivation of helping, but the subjective meaning of that arousal in terms of an accompanying sense of responsibility for the other person's plight. (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spontaneous Ionization of Gases at High Temperature

When sufficient thermal energy is available, the molecules cules of a gas are ionized at a rate that can significantly affect the operation of an electrostatic precipitator. At a given temperature, thermal effects may depend more on the presence of minority ionic species such as O- and the alkali metals than on the bulk constituents of the gas, and the electrical behavior of a precipitator will be strongly influenced by traces of such impurities. These effects may become noticeable even below 1500°F.     

Directed mutagenesis studies of the metal binding site at the subunit interface of Escherichia coli inorganic pyrophosphatase

Recent crystallographic studies on Escherichia coli inorganic pyrophosphatase (E-PPase) have identified three Mg2+ ions/enzyme hexamer in water-filled cavities formed by Asn24, Ala25, and Asp26 at the trimer-trimer interface (Kankare, J., Salminen, T., Lahti, R., Cooperman, B., Baykov, A. A., and Goldman, A. (1996) Biochemistry 35, 4670-4677). Here we show that D26S and D26N substitutions decrease the stoichiometry of tight Mg2+ binding to E-PPase by approximately 0.5 mol/mol monomer and increase hexamer stability in acidic medium. Mg2+ markedly decelerates the dissociation of enzyme hexamer into trimers at pH 5.0 and accelerates hexamer formation from trimers at pH 7.2 with wild type E-PPase and the N24D variant, in contrast to the D26S and D26N variants, when little or no effect is seen. The catalytic parameters describing the dependences of enzyme activity on substrate and Mg2+ concentrations are of the same magnitude for wild type E-PPase and the three variants. The affinity of the intertrimer site for Mg2+ at pH 7.2 is intermediate between those of two Mg2+ binding sites found in the E-PPase active site. It is concluded that the metal ion binding site found at the trimer-trimer interface of E-PPase is a high affinity site whose occupancy by Mg2+ greatly stabilizes the enzyme hexamer but has little effect on catalysis.     

Low-power digital communication with unterminated transmissionlines

Conventional telecommunication techniques are optimized to communicate over long distances (>1 mi), subject to high attenuation, high crosstalk, and other deteriorations in transmission. A trend in telecommunication system architectures is to disperse the previously centralized switching centers, thereby providing switching within a few hundred feet of the subscriber. This creates an opportunity for great improvements in cost and performance for short distance communication links. A technique for low-power digital communication over short transmission lines that exploits this possibility is described. The typical power is more than an order of magnitude lower than the power required with conventional circuits. Associated with this technique are a tenfold reduction in the chip area occupied by the transmission line drivers and the elimination of coupling transformers. The power and chip-area reductions result from terminating and maintaining an open circuit at the receiver. These advantages make this line-driving technique particularly suitable for single-chip VLSI systems     

Job migration in HPC clusters by means of checkpoint/restart

Until now, jobs running on HPC clusters were tied to the node where their execution started. We have removed that limitation by integrating a user-level checkpoint/restart library into a resource manager, fully transparent to both the user and running application. This opens the door to a whole new set of tools and scheduling possibilities based on the fact that jobs can be migrated, checkpointed, and restarted on a different place or in a different moment, while providing fault tolerance for every job running on the cluster. This is of utmost importance in the future generation of exascale HPC clusters, where an increasing degree and complexities of efficient scheduling make it challenging to obtain the required degree of parallelism demanded by the applications.

     

Comparison of pneumatic jets and tabs for Active Aerodynamic Load Control

A fast, efficient way to control loads on utility scale wind turbines is important for the growth of the wind industry. Microtabs and microjets are two Active Aerodynamic Load Control devices, which address this need. Both act perpendicular to the surface of the airfoil, and these actively controlled devices are used to mitigate changes in aerodynamic loading experienced by wind turbine rotors due to wind gusts, wind shear, or other atmospheric phenomena. This work explores the aerodynamic effects of microjets and then compares them to those of microtabs. Flow around an airfoil with an activated microjet at the trailing edge has been simulated using the Reynolds‐averaged Navier–Stokes solver OVERFLOW‐2. Using a Chimera overset grid topology, a microjet has been placed near the trailing edge of the lower surface of a NACA 0012 airfoil. For a jet velocity about half of the freestream velocity, the microjet can change the lift up to ΔC_L = 0.2, but the amount of change varies with the momentum coefficient of the jet. The change in lift is not symmetric for positive and negative angles of attack due to changes in the boundary layer thickness with angle of attack. Increasing the Reynolds number reduces the effectiveness of the microjet only slightly. The effects of jet velocity, jet activation time, and airfoil angle of attack on airfoil lift, drag, and pitching moment are compared with previous work, which illustrates the deployment of a microtab at the 95% chord location of a NACA 0012 airfoil. This study shows that microjets and microtabs have very similar responses in lift and pitching moment, but the drag for the microjet is noticeably lower. Copyright © 2013 John Wiley & Sons, Ltd.     

Saccharomyces spores are born prepolarized to outgrow away from spore–spore connections and penetrate the ascus wall

How nonspore haploid Saccharomyces cells choose sites of budding and polarize towards pheromone signals in order to mate has been a subject of intense study. Unlike nonspore haploids, sibling spores produced via meiosis and sporulation by a diploid cell are physically interconnected and encased in a sac derived from the old cell wall of the diploid, called the ascus. Nonspore haploids bud adjacent to previous sites of budding, relying on stable cortical landmarks laid down during prior divisions, but because spore membranes are made de novo, it was assumed that, as is known for fission yeast, Saccharomyces spores break symmetry and polarize at random locations. Here, we show that this assumption is incorrect: Saccharomyces cerevisiae spores are born prepolarized to outgrow, prior to budding or mating, away from interspore bridges. Consequently, when spores bud within an intact ascus, their buds locally penetrate the ascus wall, and when they mate, the resulting zygotes adopt a unique morphology reflective of repolarization towards pheromone. Long‐lived cortical foci containing the septin Cdc10 mark polarity sites, but the canonical bud site selection programme is dispensable for spore polarity, thus the origin and molecular composition of these landmarks remain unknown. These findings demand further investigation of previously overlooked mechanisms of polarity establishment and local cell wall digestion and highlight how a key step in the Saccharomyces life cycle has been historically neglected.     

Broadband video switching

A broadband 64×16 space-switching approach and its applicability to large-scale broadband switching systems are described. The design uses a technique that prevents the parasitic capacitances from reducing the switching speed. The switching system was implemented in 3-μm CMOS VLSI and operated in excess of 150 Mb/s. Computer simulation indicates a 1-Gb/s potential with a 1-μm CMOS implementation     

Safety, efficacy, and cost of pancreaticoduodenal resection in a specialized center based at a community hospital

OBJECTIVE: To determine whether pancreaticoduodenal resection (PDR) for benign and malignant disease can be performed safely, efficiently, and economically at a 50-bed community hospital. DESIGN: Retrospective review of 39 consecutive PDRs performed in an 18-month period. Indications for surgery, length of hospital stay, complications, and patient charges were analyzed. SETTING: A suburban 50-bed community hospital. PATIENTS: Thirty-nine patients (15 male and 24 female) referred for PDR for benign and malignant disease. MAIN OUTCOME MEASURES: Mortality and morbidity rates, length of hospital stay, care, and cost. RESULTS: Of 39 patients who underwent PDRs, 1 patient (2.6%) died of myocardial infarct. Intraoperative blood transfusions were required by 3 patients (8%). The mean postoperative hospital stay was 11 days. Twenty-four patients (62%) were discharged by day 11. Fifteen patients (38%) were hospitalized 11 to 24 days. Complications in 10 patients (28%) included pancreatic or biliary fistula (n = 6), upper gastrointestinal tract bleeding (n = 1), partial wound dehiscence (n = 1), bacteremia (n = 1), and pneumonia (n = 1). No patient required reoperation. Three patients were rehospitalized within 1 month. Mean patient charges were $21,864, and mean reimbursements were $19,669. CONCLUSIONS: Pancreaticoduodenal resection can be accomplished with low morbidity and mortality rates and a short stay at a community hospital. Thorough preoperative investigations to exclude unresectable lesions must precede every PDR for malignant disease. Mortality and morbidity rates in this series were similar to those for patients with similar diagnoses who were operated on in academic centers. Cost for and length of hospital stay of these 39 patients were significantly lower than those in other reported series.