EMF genes regulate Arabidopsis inflorescence development

Mutations in EMBRYONIC FLOWER (EMF) genes EMF1 and EMF2 abolish rosette development, and the mutants produce either a much reduced inflorescence or a transformed flower. These mutant characteristics suggest a repressive effect of EMF activities on reproductive development. To investigate the role of EMF genes in regulating reproductive development, we studied the relationship between EMF genes and the genes regulating inflorescence and flower development. We found that APETALA1 and AGAMOUS promoters were activated in germinating emf seedlings, suggesting that these genes may normally be suppressed in wild-type seedlings in which EMF activities are high. The phenotype of double mutants combining emf1-2 and apetala1, apetala2, leafy1, apetala1 cauliflower, and terminal flower1 showed that emf1-2 is epistatic in all cases, suggesting that EMF genes act downstream from these genes in mediating the inflorescence-to-flower transition. Constitutive expression of LEAFY in weak emf1, but not emf2, mutants increased the severity of the emf phenotype, indicating an inhibition of EMF activity by LEAFY, as was deduced from double mutant analysis. These results suggest that a mechanism involving a reciprocal negative regulation between the EMF genes and the floral genes regulates Arabidopsis inflorescence development.     

Remote sensing of the Earth's atmosphere from space with high-resolution Fourier-transform spectroscopy: development and methodology of data processing for the Atmospheric Trace Molecule Spectroscopy experiment

The methodology of spectroscopic remote sensing with high-resolution Fourier-transform spectra obtained from low Earth orbit by the Atmospheric Trace Molecule Spectroscopy (ATMOS) experiment is discussed. During the course of the Atmospheric Laboratory for Applications and Science (ATLAS) shuttle missions (1992-1994) a flexible, yet reproducible, retrieval strategy was developed that culminated in the near-real-time processing of telemetry data into vertical profiles of atmospheric composition during the ATLAS-3 mission. The development, evolution, robustness, and validation of the measurements are presented and assessed with a summary comparison of trace-gas observations within the Antarctic polar vortex in November 1994.     

考尔德"动与静"的艺术世界

文章对美国现代抽象主义雕塑大师亚历山大·考尔德(1898-1976)的作品和创作风格作了介绍,在20世纪现代艺术和现代建筑蓬勃发展的背景下,考尔德开拓性的探索现代雕塑形式、空间及材料,在西方现代雕塑艺术发展中起到了承前启后的作用.他的活动雕塑和固定雕塑是对20世纪的重大贡献.     

Synthesis of nanoporous platinum thin films and application as hydrogen sensor

A nanoporous platinum (np-Pt) thin film based hydrogen sensor was fabricated and studied. The np-Pt thin films were fabricated through a method of chemical dealloying and coarsening starting from a CuPt alloy. The alloy thin films of Cu_xPt_1?x were deposited by sputtering copper and platinum at the same time. The dealloying process completely removed the copper from the film. We demonstrate a method to control the porosity of np-Pt by a method of coarsening. Scanning electron microscopy confirmed the presence of porosity with size ranging from a few nanometers to tens of nanometers. A sensor device with four electrodes was fabricated on the np-Pt thin films using a stainless steel mask and by sputtering copper. The electrical characteristics of the sensor exhibit marked sensitivity or current changes in the presence of hydrogen. The results demonstrate that np-Pt thin films configured as a gas sensor have high sensitivity to hydrogen.     

转动露华浓粉底瓶

露华浓的双重分配包装考验了新粉底的创新。转盘控制器混合着抹到皮肤上的粉底,在带给女性便利的同时,减少了浪费。即使拥有非常时髦有型的化装刷和工具,变美也是一项棘手的工作。涂抹化妆品对于有些人来说可能是浪费时间,甚至会产生一种压力,或者完全就是无用的。纽约市的露华浓消费品公司     

Inhibition of return in discrimination tasks.

Although inhibition of return is known to affect a wide range of detection tasks, it has not been found consistently in discrimination tasks. To examine this issue, 5 experiments were conducted in which participants discriminated between a visual target and a distractor. The responses were not inhibited if, before the onset of stimuli, attention had been overtly oriented (i.e., an eye movement was made) to the future target location and the stimulus at that location was the same symbol as the upcoming target. However, if attention was covertly oriented (i.e., no eye movement was made) to the future location of the target, or if the stimulus at the earlier attended location was a symbol different from the target, responses to the target were inhibited. Overall, the findings provide insights into the relation between movements of attention and discrimination judgments and support the notion that inhibition of return is an attentional phenomenon. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spatially diffuse inhibition affects multiple locations: A reply to Tipper, Weaver, and Watson (1996).

S. Tipper, B. Weaver, and F. Watson (see record 84-02784) suggest that J. Pratt and R. A. Abrams's (see record 1996-16290-001) failure to find inhibition of return for more than the most recently cued location was because their 2-target display did not adequately capture some of the complexity of real-world visual environments. However, Tipper et al. tested a special case because they always cued 3 out of 4 potential targets (allowing cued and uncued locations to be segregated into 2 spatial regions). The authors show that only the 1 most recently cued location will be inhibited when 2 nonadjacent targets out of 4 possible targets are cued, but both cued locations will be inhibited when they are adjacent. Also, only the 1 most recently cued location was inhibited when 3 nonadjacent targets out of 6 potential target locations were cued. Thus, in a complex environment in which several cued locations are interspersed among noncued locations, inhibition of return will occur for only the 1 most recently attended location, consistent with conclusions of Pratt and Abrams. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Relevance of cue reactivity to understanding alcohol and smoking relapse.

Several learning-based theories have been forwarded to account for the problem of drug relapse, including conditioned withdrawal, conditioned compensatory responding, appetitive motivational models, and social learning models. The various models are compared and evaluated against available evidence from studies with humans pertaining to alcohol and tobacco addiction. Studies that are reviewed focus primarily on the antecedents and consequences of alcohol and smoking relapse, as well as on reactions to cues that have been associated with prior drug ingestion, in an attempt to understand their motivational relevance. Problems in evaluating the various relapse models in humans are discussed. It is concluded that the appetitive model is better supported than the withdrawal model, and the compensatory model is least supported. Reactions to substance use stimuli may play an important role in alcohol and smoking relapse. Concepts drawn from the various theoretical models are linked tentatively in a schematic diagram of a hypothesized sequence of cognitive/affective, physiological, and behavioral events that lead to initial drug use after a period of abstinence (slip) and then to continued use (a relapse). The treatment implications of some of the cue reactivity models are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Pro-norm and anti-norm deviance within and between groups.

Participants evaluated other individuals who deviated in either an anti- or pro-normative direction relative to normative members. In Study 1, in-group gender-normative members were rated more positively than deviant members. The pro-norm deviant was viewed as more attractive than the anti-norm deviant. In Study 2 anti-norm in-group deviants were evaluated more negatively than anti-norm out-group deviants even though both held identical attitudes. In both studies, despite objective equivalence, pro-norm deviance was perceived as less "atypical" than anti-norm deviance. Judgments and reactions to deviance depend on group membership and the direction of deviance, not just its magnitude. Evaluations of deviants are also related to perceivers' identification with their own group. These findings are consistent with our model of subjective group dynamics. (PsycINFO Database Record (c) 2010 APA, all rights reserved)