Measurement of Power Frequency Fluctuations Using the FFT

A new method for detecting fluctuations in the fundamental frequency component of a power system, by relating it to a leakage coefficient in the FFT, is presented. The phenomenon of leakage in the FFT is used advantageously to increase spectral resolution. The leakage coefficient is a quantitative measure of the deviation from the fundamental frequency component with respect to the sampling frequency. Theoretical aspects are considered along with a method for on-line implementation.     

"Eating for optimal health: how much should we eat?": Comment.

Responds to commentaries by K. M. Vitousek and J. Gray (see record 2002-12932-011) and F. P. Manke and K. M. Vitousek (see record 2002-12932-012) on the original article (see record 2000-02781-002) that argued that because of the scarcity and unpredictability of food in nature, humans and other animals have evolved to eat to their physiological limits when food is readily available, so that excess energy can be stored in the body as a buffer against future food shortages. The current authors state that neither of the two commentaries challenged the main thesis of their article; they focused instead on its potential implications for good health. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of communication, information overlap, and behavioral consistency on consensus in social perception.

Three experiments (N?=?69, 162, and 201, respectively) were conducted to test the mathematically derived predictions of the Weighted Average Model (D. A. Kenny, 1991) of consensus in interpersonal perception. Study 1 estimated the effect of perceiver communication, Study 2 estimated the effects of communication and stimulus overlap, and Study 3 estimated the effects of communication, overlap, and target consistency on consensus. The strongest consensus was found when perceivers communicated about highly overlapping information about targets who were cross-situationally consistent. Conversely, the lowest level of consensus was observed when perceivers did not communicate and had nonoverlapping information about targets who were cross-situationally inconsistent. Both stimulus variables (overlap and consistency) and an interpersonal variable (communication) affected consensus as predicted by the Weighted Average Model. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Allelopathic potential of sorghum (Sorghum bicolor)

The major inhibitory components obtained after fractionation of an aqueous extract of field-grown sorghum (Sorghumbicolorcv. Bird-a-boo) herbage were quantified in terms of biological potency by indexing three aspects of cumulative cress (Lepidium sativum cv. Curlycress) seed germination. The inhibitory potential expressed in the crude aqueous extract reflected a complex interaction of numerous individual components of diverse chemical compositions and potencies. Some of these inhibitory components included chemical classes not previously associated with herbage phytotoxicity.     

Incubation effect in the cockroach (Periplaneta Americana).

Recorded in Exp I the activity of 72 cockroaches in an open field in which they had received footshock (FS) 1, 3, 10, 30, or 120 min before. The FS produced an incubation effect, i.e., a general decrease in activity, with the greatest decrease occurring at the longer intervals. In Exp II, activity of 77 cockroaches was recorded in an open field 120 min after 1 FS and 1, 3, 10, or 30 min after a 2nd. When no 2nd FS was administered, the cockroaches were inactive; however, when testing occurred within 10 min of the 2nd FS, activity was greatly increased. This gradient of hyperactivity paralleled exactly the incubation effect demonstrated in Exp I. Results of both experiments are almost identical to the results of comparable experiments in which rats have served as Ss. Thus, the incubation effect is an adaptive behavior pattern resulting from the transient activating effects of noxious stimulation. (29 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The observers and the observed: The effects of doing ratings on staff-patient contact patterns.

On a research ward where nursing personnel have both research and clinical responsibilities, the effect of staff's rating of patients' behavior on frequency of contacts was assessed. Percentages of staff's contacts with patients and with other staff were compared on days when the staff was doing the ratings with days when it was not. There were no differences in the percentage of interactions with patients on rating and nonrating days. There were more interactions with staff on rating days. This finding suggests that although doing rating did not interfere with patient-staff relations, the increase in staff-staff contacts might be due to rating staff obtaining more information upon which to base their ratings by talking to other staff members. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Rhinal cortex lesions and object recognition in rats.

Tested 11 male rats with bilateral lesions of lateral entorhinal cortex and perirhinal cortex on a nonrecurring-items delayed nonmatching-to-sample (DNMS) task resembling the one that is commonly used to study object recognition (OR) in monkeys. The rats were tested at retention delays of 4, 15, 60, 120, and 600 sec before and after surgery. After surgery, they displayed a delay-dependent deficit: They performed normally at the 4-sec delay but were impaired at delays of 15 sec or longer. The addition of bilateral amygdala lesions did not increase their DNMS deficits. The present finding of a severe DNMS deficit following rhinal cortex damage is consistent with the authors' previous finding that bilateral lesions of the hippocampus cause only mild DNMS deficits in rats unless there is also damage to rhinal cortex (D. G. Mumby et al, 1992). These findings add to accumulating evidence that the rhinal cortex, but not the amygdala, plays a critical role in OR. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

应对生物样品中生长促进剂领域的新挑战

Xevo TQ质谱系统能在规定的最大残留量（maximum residue limit,MRL）水平上高灵敏地检测皮质类固醇,为复杂体系如肝脏分析方法的缺少提供了一条解决途径。此外,中性丢失模式的高灵敏度使得皮质类固醇和β-兴奋剂新的种属筛选变得更为容易。     

The Chlorophyll Catabolite,Pheophorbide <Emphasis Type="Italic">a</Emphasis>, Confers Predation Resistance in a Larval Tortoise Beetle Shield Defense

Larval insect herbivores feeding externally on leaves are vulnerable to numerous and varied enemies. Larvae of the Neotropical herbivore, Chelymorpha alternans (Chrysomelidae:Cassidinae), possess shields made of cast skins and feces, which can be aimed and waved at attacking enemies. Prior work with C. alternans feeding on Merremia umbellata (Convolvulaceae) showed that shields offered protection from generalist predators, and polar compounds were implicated. This study used a ubiquitous ant predator, Azteca lacrymosa, in field bioassays to determine the chemical constitution of the defense. We confirmed that intact shields do protect larvae and that methanol-water leaching significantly reduced shield effectiveness. Liquid chromatography-mass spectrometry (LC-MS) of the methanolic shield extract revealed two peaks at 20.18 min and 21.97 min, both with a molecular ion at m/z 593.4, and a strong UV absorption around 409 nm, suggesting a porphyrin-type compound. LC-MS analysis of a commercial standard confirmed pheophorbide a (Pha) identity. C. alternans shields contained more than 100 μg Pha per shield. Shields leached with methanol-water did not deter ants. Methanol-water-leached shields enhanced with 3 μg of Pha were more deterrent than larvae with solvent-leached shields, while those with 5 μg additional Pha provided slightly less deterrence than larvae with intact shields. Solvent-leached shields with 10 μg added Pha were comparable to intact shields, even though the Pha concentration was less than 10% of its natural concentration. Our findings are the first to assign an ecological role for a chlorophyll catabolite as a deterrent in an insect defense.     

Modeling of the Bistatic Electromagnetic Scattering From Sea Surfaces Covered in Oil for Microwave Applications

This paper describes the influence of oil pollution over sea surfaces on the height spectrum and the height autocorrelation function of rough surfaces. An oil slick damps the capillarity waves of the surface height spectrum and reduces the root mean square slope of the surface. These modified functions then have an influence on the radar cross section (RCS) from contaminated sea surfaces. The bistatic RCS of the contaminated sea surface is then presented by comparison with a clean sea: results from a benchmark numerical model are presented and compared with a new semiempirical model using the geometric optics approximation and then the first-order smallslope approximation.