Photolytic generation of an o-quinodimethane derivative and its reactions with unsaturated polymers

Polybutadiene was treated with o-tolualdehyde under UV irradiation to produce random copolymers through Diels-Alder reactions on the backbone double bonds. The physical properties of the polymer products change as more of the aldehyde attaches to it. The copolymers were characterized by NMR spectroscopy. A bifunctional o-tolualdehyde was synthesized and used as a crosslinking agent. Received: 19 September 1997/Accepted: 24 November 1997     

Convex and Semi-Nonnegative Matrix Factorizations

We present several new variations on the theme of nonnegative matrix factorization (NMF). Considering factorizations of the form X=FG^T, we focus on algorithms in which G is restricted to containing nonnegative entries, but allowing the data matrix X to have mixed signs, thus extending the applicable range of NMF methods. We also consider algorithms in which the basis vectors of F are constrained to be convex combinations of the data points. This is used for a kernel extension of NMF. We provide algorithms for computing these new factorizations and we provide supporting theoretical analysis. We also analyze the relationships between our algorithms and clustering algorithms, and consider the implications for sparseness of solutions. Finally, we present experimental results that explore the properties of these new methods.     

Mesencephalic reticular formation lesions made after habituation training abolish long-term habituation of the acoustic startle response in rats.

Lesions to the mesencephalic reticular formation (MRF) in rats severely attenuate the acquisition of long-term habituation of the startle response when the lesions are made prior to habituation training. The present experiments extend the finding of habituation deficits to animals with MRF damage made after the animals have habituated to an auditory stimulus. Following habitation training, some animals received lesions to the MRF. The startle amplitudes of these animals immediately changed from control levels to levels indistinguishable from those of animals that never habituated across days—animals with MRF lesions made prior to habituation training. The mechanism responsible for long-term habituation appears to be a progressive increase in activity within a long-term habituation pathway extrinsic to the reflex circuit for the startle response, but the synaptic mechanisms responsible for this change are unknown. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Assessment of cohesion and adaptability in component family dyads: A question of convergent and discriminant validity.

In the assessment of family cohesion and adaptability, researchers typically overlook the possibility that different components of the family may be more cohesive or adaptable than others. This potential problem is often compounded by monomethodism, reliance on a single source of information. Using a multitrait-mutimethod approach, we obtained three measures of cohesion and adaptability in three component dyads of relatively healthy families. Mothers, fathers, and college students reported about cohesion and adaptability in the mother–student, father–student, and mother–father relationships. Using confirmatory factor analysis, we found significant differences in the convergent validities of mothers', fathers', and students' reports. Furthermore, significant differences emerged among the correlations between mother–father, mother–student, and father–student cohesion (and adaptability), which suggests that noteworthy differences exist between family subsystems on these constructs. Implications for assessment strategies in marital and family counseling are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Room-temperature oxidation of reduced Cu/ZnO surfaces by lattice oxygen diffusion

At room temperature in the absence of gas-phase oxygen, reduced Cu on Cu/ZnO extracts oxygen from the ZnO lattice to reoxidize the surface. After 120 min at room temperature, diffusion of lattice oxygen reoxidizes reduced Cu/ZnO to 3% of its completely oxidized state. When gas-phase oxygen is present, it promotes the partial reoxidation of the reduced Cu/ZnO surface at room-temperature.     

Alternative Australian climate change plans: The public’s views

Climate change has come to the forefront of Australian politics and there is now an active on-going policy debate about how to best reach a commonly agreed long term goal. This paper looks at five major dimensions of this debate and constructs policy options based on them. A discrete choice experiment approach was used with a representative sample from a major internet panel provider. Survey respondents made choices between pairs of policy options with different characteristics. They favored policies starting in 2010 rather than 2012, and spending 20% of revenue raised on energy-related R&D. They were almost evenly split on whether the plan should initially exempt the transport sector and two competing approaches that redistribute revenue from the plan, and, they opposed plans giving special treatment to energy-intensive sectors of the economy. A number of other policy relevant questions related to understanding Australian views and knowledge related to climate change also were asked.     

Dieting and depression: A methodological study.

Examined the effects of 3 variables on reports of psychological functioning in 28 obese women (mean age 42.1 yrs) who lost an average of 19.2 kg in 6 mo. Analysis of the 1st variable, frequency of assessment, showed that although Ss experienced improvements in mood from pre- to posttreatment, more than 50% showed worsening in mood during 1 or more wks. Analysis of the 2nd variable, time of assessment, revealed that retrospective reports of depression and anxiety were greater than were concurrent reports. Analysis of the 3rd variable, method of assessment, showed that Ss reported several symptoms in response to an open-ended interview that were not measured by objective tests. Data indicate that the method of mood assessment determines the answer to the question of whether dieting is associated with adverse psychological consequences. (9 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Complex resonances of conducting spheres with lossy coatings

The electromagnetic scattering amplitude for metal objects coated with a lossless dielectric exhibits a large number of resonances versus real frequency. These resonances are a function of the object shape and size, coating thickness, and coating electrical properties. Previously, it was shown that for coated spheres and nonspherical bare objects, these resonances can be understood in terms of phase matched circumnavigating surface waves and the objects' complex eigenfrequencies. The effect of dielectric loss in the coating on the complex eigenfrequencies and phase velocities of these surface waves is presented for a metal sphere coated with a uniform homogeneous dielectric coating. It is seen that the positions of the complex resonance frequencies move away from the real frequency axis under the influence of dielectric loss in the coating. The effect of this is shown to correspond to the changes in the backscatter spectrum versus real frequency as computed using a Mie series expansion. The significant difference between the lossless and lossy dielectric-coated sphere cases is seen to be due to a modification of the phase velocities of surface waves, particularly the whispering gallery types, and the increased attenuation of the surface wave modes