Avfail in color avoidance learning by starlings (Sturnus vulgaris) and red-winged blackbirds (Agelaius phoeniceus).

Certain unconditioned stimulus/stimuli (UCS) in flavor avoidance learning sometime become ineffective after pairings with relatively stronger UCS. This failure of avoidance learning (avfail) has been demonstrated only with rodents. The present investigations examined whether avfail might also occur with avian species, the food selection of which is guided primarily by visual cues. In Exp I, 20 male starlings were given pairings of 2 mg/kg methiocarb (a relatively weak UCS) and LiCl (a relatively strong UCS) in propylene glycol vehicle. In Exp II, 20 male red-winged blackbirds were given pairings of 2 or 4 mg/kg methiocarb (relatively weak and relatively strong UCS, respectively). Pairings were followed by a conditioning trial (UCS gavage in the presence of a color cue) and 2-choice tests. Conditioned avoidance was observed except (a) when methiocarb preceded LiCl and (b) when the low preceded the high methiocarb dose in preconditioning pairings. Exp III, with 20 Ss of each species, demonstrated that UCS habituation could not account for the results of Exps I and II. The data reflect avfail in the visual modality, and a biological implication of the results is that birds may not learn strong avoidance of aposematic prey containing varied levels of toxicant. (23 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Induction Machine Phase Balancing by Unsymmetrical Thyristor Voltage Control

High inrush currents and unbalanced supply voltages are two of the major causes for failure of polyphase induction machines. While thyristor voltage controllers, sometimes called static starters, are in widespread use to limit damaging inrush currents, little attention has been paid to the use of these controllers to balance the phases voltages of the machine. The technical feasibility of unsymmetric control to limit unbalanced currents is explored. A substantial reduction in losses is shown to be possible for two specific types of unbalance.     

High-temperature low-cycle fatigue of an iron-base oxide-dispersion strengthened alloy: Grain structure effects and lifetime correlations

The high-temperature low-cycle fatigue (LCF) behavior of the new oxide-dispersion strengthened (ODS) alloy PM 2000 is investigated at 1050 °C using symmetrical and asymmetrical wave shapes. The grain structures range from “single crystals” (grain size of several centimeters) to polycrystals with an average grain size of less than 30 μm. It is found that the grain structure determines the fracture path but cannot be correlated with cyclic lifetimes. Instead, lifetime can be predicted on the basis of the different Young’s moduli of the grain structures and correlates with the reciprocal of Young’s modulus. A normalization is proposed that condenses all lifetime data, which span two orders of magnitude, into a narrow scatterband.     

Pulvermetallurgisch durch heißisostatisches Pressen hergestellter Warmarbeitsstahl X 40 CrMoV 5 1

Die Verfahrensparameter für die heißisostatische Pulververdichtung des Warmarbeitsstahles X 40 CrMoV 5 1 (Werkstoffnummer 1.2344) werden aus der Beurteilung der mechanischen Festigkeitswerte sowie des Bruch- und Schliffgefüges festgelegt. Hierbei erweist sich die Schlagbiegearbeit der ungekerbten Probe als besonders kritische Meßgröße zur Optimierung der einzelnen Prozeßschritte. Die am PM-Stahl ermittelten statischen und dynamischen Festigkeitswerte werden den Werten der konventionellen SM-Legierung gegenübergestellt.     

Acute effects of cigarette smoking on fetal cardiovascular and uterine Doppler parameters

The purpose of this study was to assess the effects of smoking one cigarette (nicotine mean 0.63 +/- 0.17 mg) on uterine- and foetal cardiovascular Doppler parameters in healthy pregnant smokers. All pregnancies (n = 16; mean gestational age: 36 +/- 4 weeks) had been uneventful and all foetuses were appropriate for gestational age with normal baseline Doppler parameters and normal foetal outcome (birthweight: 3254 +/- 340 grams). Measurements, performed immediately before and after smoking, included pulsatility index (PI) of umbilical artery (UA), middle cerebral artery (MCA), foetal descending aorta and uterine artery as well as maternal and foetal heart rate. The ratio of UA/MCA PI was used to assess centralisation. Changes in foetal cardiac output were determined by: time-velocity integral times heart rate, at aortic and pulmonary valve level. Foetal heart rate (p < 0.0005, paired t-test) and maternal heart rate (p < 0.05) increased significantly. All other parameters did not change significantly. However, in one additional woman with labile hypertension and increased baseline uterine artery PI (1.9), smoking of one cigarette caused a substantial rise in uterine artery PI to 3.25 ten minutes after smoking. Middle cerebral artery PI decreased from 2.2 to 1.18 with an unchanged cardiac output and umbilical artery PI raising the UA/MCA PI ratio from 0.51 to 0.81, suggesting a brain sparing effect. Smoking of one cigarette raised maternal and foetal heart rate. There was no evidence of other cardiovascular effects or centralisation in healthy foetuses of normal pregnancies, but this might not be true in foetus of pathologic pregnancies.     

Effect of Nanopowder Addition on the Sintering of Water-Atomized Iron Powder

Metallurgical and Materials Transactions A - A promising method of improving the densification of powder metallurgical steel components is to blend nanopowder with the otherwise typically used...     

Slice and Dice: A Physicalization Workflow for Anatomical Edutainment

During the last decades, anatomy has become an interesting topic in education—even for laymen or schoolchildren. As medical imaging techniques become increasingly sophisticated, virtual anatomical education applications have emerged. Still, anatomical models are often preferred, as they facilitate 3D localization of anatomical structures. Recently, data physicalizations (i.e., physical visualizations) have proven to be effective and engaging—sometimes, even more than their virtual counterparts. So far, medical data physicalizations involve mainly 3D printing, which is still expensive and cumbersome. We investigate alternative forms of physicalizations, which use readily available technologies (home printers) and inexpensive materials (paper or semi-transparent films) to generate crafts for anatomical edutainment. To the best of our knowledge, this is the first computer-generated crafting approach within an anatomical edutainment context. Our approach follows a cost-effective, simple, and easy-to-employ workflow, resulting in assemblable data sculptures (i.e., semi-transparent sliceforms). It primarily supports volumetric data (such as CT or MRI), but mesh data can also be imported. An octree slices the imported volume and an optimization step simplifies the slice configuration, proposing the optimal order for easy assembly. A packing algorithm places the resulting slices with their labels, annotations, and assembly instructions on a paper or transparent film of user-selected size, to be printed, assembled into a sliceform, and explored. We conducted two user studies to assess our approach, demonstrating that it is an initial positive step towards the successful creation of interactive and engaging anatomical physicalizations.