Children, robotics, and education

Popular interest in robotics has increased astonishingly in the last few years. Robotics is seen by many as offering major new benefits in education at all levels. Before rushing to exploit this popularity, educators should ask serious questions about the universality and longevity of the robotics phenomenon. Is it a fashion? To be useful, the energy released by robotics must be sustained and universal, and the means of exploiting it must be systematic. Universities define their own robotics curriculum, but most schools lack both the resources and the freedom to do this, and must work with a national curriculum. If it can be shown that robotics has sustained potential in education, it seems inevitable that new ways need to be found to integrate it into the school curriculum.     

Tilted superlattice composition profile determined by photoluminescence and thermal disordering

The composition profile of an (AlAs)_1/2(GaAs)_1/2 tilted superlattice is characterized for the first time. The tilted superlattice sample is thermally disordered, and the energy of the direct band gap photoluminescence peak is measured as a function of increasing layer interdiffusion. The shift in the photoluminescence peak energy after completely disordering the tilted superlattice is 39 meV. A theoretical model is used to simulate the change in band gap as a function of layer interdiffusion for several composition profiles. The profile that gives the best fit to the experimental data is chosen. The tilted superlattice composition profile is found to be sinusoidal, varying from Al_0.40Ga_0.60As to Al_0.60Ga_0.40As.     

Gait function in spastic hemiparetic patients walking barefoot, with firm shoes, and with ankle-foot orthosis

Cortical spreading depression is a wave of electrical and biochemical changes that spreads across the cerebral cortex. It has been hypothesized to be an important underlying cause of the visual disturbances occurring during the migraine aura, but this is difficult to test in animals or humans. We created a computational model of cortical spreading depression and found that during the wave of biochemical changes the spatial pattern of neural activity broke up into irregular patterns of lines and small patches of highly activated elements. The corresponding visual disturbances that would be produced by these patterns of neural activity resemble the hallucinations reported during the migraine aura, providing strong support for the cortical spreading depression hypothesis of migraine. The model also makes the testable prediction that these hallucinations move at an exponentially increasing speed across the visual field.     

Advanced thin-film silicon-on-sapphire technology: microwavecircuit applications

This paper reviews the prospects of thin-film silicon-on-sapphire (TFSOS) CMOS technology in microwave applications in the 1-5 GHz regime and beyond and presents the first demonstration of microwave integrated circuits based on this technology, MOSFET's optimized for microwave use, with 0.5-μm optically defined gate lengths and a T-gate structure, have f_t values of 25 GHz (14 GHz) and f_max values of 66 GHz (41 GHz) for n-channel (p-channel) devices and have noise figure values below 1 db at 2 GHz, some of the best reported performance characteristics of any silicon-based MOSFET's to date. On-chip spiral inductors exhibit quality factors above ten. Circuit performance compares favorably with that of other CMOS-based technologies and approach performance levels similar to those obtained by silicon bipolar technologies. The results demonstrate the significant potential of this technology for microwave applications     

Pigmentation phenotypes of variant extension locus alleles result from point mutations that alter MSH receptor function

Coat colors in the chestnut horse, the yellow Labrador retriever, the red fox, and one type of yellow mouse are due to recessive alleles at the extension locus. Similarly, dominant alleles at this locus are often responsible for dark coat colors in mammals, such as the melanic form of the leopard, Panthera pardus. We show here that the murine extension locus encodes the melanocyte-stimulating hormone (MSH) receptor. In mice, the recessive yellow allele (e) results from a frameshift that produces a prematurely terminated, nonfunctioning receptor. The sombre (Eso and Eso-3J) and tobacco darkening (Etob) alleles, which both have dominant melanizing effects, results from point mutations that produce hyperactive MSH receptors. The Eso-3J receptor is constitutively activated, while the Etob receptor remains hormone responsive and produces a greater activation of its effector, adenylyl cyclase, than does the wild-type allele.     

Disturbance of continuous, pump administration of cardiovascular drugs by hydrostatic pressure

Administration of highly concentrated, highly potent, and therefore highly dangerous drugs with syringe pumps is common in modern anaesthesia as well as in intensive care and emergency medicine. Because of their exact flow rates down to < 1 ml/h, these pumps are predestined for delivery of drugs with short half-lives, such as catecholamines and vasodilators. But intravenous application of drugs with syringe pumps is not without problems. While it is well known that syringes not fixed correctly into the pump can empty themselves by the influence of gravity, it seems not to be known that hydrostatic pressure can influence the flow rate of a correctly connected system even during continuous infusion. In this situation a change of height of the syringe pump in relation to the patient's position can have tremendous effects on hemodynamics due to unintended acceleration or deceleration of the flow rate. This case report demonstrates that the elevation of a connected epinephrine pump while moving a cardiac surgery patient after ACB operation from the operation table into his bed led to critical increases of heart rate, blood pressure and left atrial pressure. In order to quantify the problem we repeated the situation experimentally. It could be demonstrated that the elevation of the syringe pump by 80-100 cm delivers an additional bolus of 4-5 drops as the central venous catheter outlet. Lowering the pump consecutively leads to the opposite effect. In the case reported, the accidentally administered bolus of epinephrine was 12-15 micrograms (we use a concentration of 60 micrograms/ml epinephrine for continuous infusion with syringe pumps). From this accidental observation the following conclusion can be drawn: The change of height, in relation to the patient's position, of a running syringe pump during continuous infusion of highly concentrated cardiovascular drugs may cause considerable, even life-threatening hemodynamic disorders. Even in a closed infusion system (syringe-extension-central venous catheter), hydrostatic pressure influences infusion rate. Elevation of the pump leads to unintended bolus administration, and lowering of the pump is followed by an interruption of the infusion. In the knowledge of this phenomenon, unexpected hemodynamic reactions during transport of critically ill patients cannot always be interpreted as a result of inadequate anesthesia or volume load, but may be a consequence of incorrect handling of the syringe pumps as described in this report.     

Pectoralis major tendon avulsion in association with a proximal humerus fracture

We report a very rare case of an avulsion of the pectoralis major tendon in association with a two-part proximal humerus fracture. Pectoralis major tendon avulsion was confirmed intraoperatively during open reduction and internal fixation of the humerus fracture. In retrospect, the preoperative radiographic finding of posterolateral and proximal displacement of the humeral shaft suggested an injury to the pectoralis major. Because others have reported that the best treatment of a pectoralis major tendon avulsion is surgical repair, we feel that it is important to suspect such an injury in a proximal humerus fracture when this anatomic displacement is present.     

Social support knowledge and behavior and relational intimacy: A dyadic study.

Examined the relationships among social support knowledge, supportive behavior, intimacy with one's spouse, and satisfaction with support provided by one's spouse among 41 Israeli kibbutz couples. The hypothesis that support knowledge and support behavior influence the intimacy between couples and increase satisfaction with spouse's social support efforts was tested. Alternative causal mechanisms are explored with simultaneous equation modeling. Results indicate that satisfaction with social support behavior by one's spouse is mediated entirely by intimacy with one's spouse. Results also indicate that partner's knowledge about social support behavior directly affects intimacy and indirectly generates social support satisfaction independent of actual supportive behavior. The findings do not differ by sex. The consistency of the findings with family behavior exchange theory and implications for marital therapy are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)