Second order molecular nonlinearities in new orthopalladated push-pull chromophores

Three new orthopalladated chromophores based on push-pull π conjugated ligands have been prepared and characterized. The second order molecular NLO activity has been determined by EFISH measurements giving μ_gβ values up to 610×10⁻⁴⁸ esu at an incident laser wavelength of 1.907 μm. The X-ray structures of two different polymorphs of one chromophore are also reported and polymorphism is discussed in terms of conformational changes.     

Monitoring in a predator–prey systems via a class of high order observer design

The goal of this work is the monitoring of the corresponding species in a class of predator–prey systems, this issue is important from the ecology point of view to analyze the population dynamics. The above is done via a nonlinear observer design which contains on its structure a high order polynomial form of the estimation error. A theoretical frame is provided in order to show the convergence characteristics of the proposed observer, where it can be concluded that the performance of the observer is improved as the order of the polynomial is high. The proposed methodology is applied to a class of Lotka–Volterra systems with two and three species. Finally, numerical simulations present the performance of the proposed observer.     

Birth order and relationships

Previous studies (Salmon 1999; Salmon and Daly 1998) have found that sex and birth order are strong predictors of familial sentiments. Middleborns tend to be less family-oriented than firstborns or lastborns, while sex differences seem to focus on the utility of kin in certain domains. If this is a reflection of middleborns receiving a lesser degree of support from kin (particularly in terms of parental investment), are middleborns turning to reciprocal alliances outside the family, becoming friendship specialists? Are there comparable birth order differences with respect to mating strategies? In this study, the impact of birth order on attitudes toward family, friends, and mating were examined. Two hundred and forty-five undergraduates completed a questionnaire relating to their attitudes toward friends and family as well as some aspects of mating behavior. Birth order did have a significant impact in several areas. Middleborns expressed more positive views toward friends and less positive opinions of family in general. They were less inclined to help family in need than firstborns or lastborns. Mating strategies also appeared to be influenced by birth order, most notably in the area of infidelity, with middleborns being the least likely birth order to cheat on a sexual partner.     

Catastrophe and social order

This paper presents three propositions. First, the author suggests that there is a growing potential for technologically induced catastophes. Second, our capacity to analyze technological risk is inhibited in part because: (1) we tend to confuse low-probability/low-consequence events with low-probability/high-consequence risks; (2) we seldom adopt a holistic approach to the analysis of risk; and (3) we tend to underestimate the effects of catastrophic events. The author further argues that existing control systems, including federal regulatory bodies, are inadequate. In the conclusion the author discusses difficulties likely to accompany the design and creation of risk control systems.     

Testing hypotheses in order

In certain circumstances, one wishes to test one hypothesisonly if certain other hypotheses have been rejected. This orderingof hypotheses simplifies the task of controlling the probabilityof rejecting any true hypothesis. In an example from an observationalstudy, a treated group is shown to be further from both of twocontrol groups than the two control groups are from each other.