Solid‐supported synthesis of hyperbranched polymer with β,β‐diethynylstyryl units

Two novel aromatic polyamide supports bearing aromatic bromine and iodine functionality have been synthesised and tested for the solid‐supported polymerization of AB₂ type monomer 4‐(5‐hexynyloxy)‐β,β‐dibromostyrene via Pd‐catalysed cross‐coupling of vinyl halides and terminal acetylenes. It was found that the solid‐supported polymerization leads to a decrease in molecular weight and increase in the degree of branching from 17 000–18 000 g mol⁻¹ to 8000–4000 g mol⁻¹ and from 30–35 % to 50–65 %, respectively, compared to solution polymerization. All other things being equal, the decrease in molecular weight of hyperbranched polymer on solid‐supported polymerization is a function of the distance between adjacent active sites of the polymer support. © 2001 Society of Chemical Industry     

Amphiphilic Core/Shell Nanoparticles to Reduce Biocide Leaching From Treated Wood, 1 – Leaching and Biological Efficacy

Core/shell nanoparticles containing the fungicide tebuconazole were prepared from amphiphilic copolymers of gelatin grafted with MMA. The grafting was performed in water at levels of 1.5–15 wt.‐% solids based on matrix mass, to give core/shell nanoparticles with median diameters ranging from ≈200 to 400 or ≈10 to 100 nm depending on composition, conditions used, and work‐up. The biocide‐containing nanoparticles were delivered into wood in up to 85% efficiency. Wood blocks treated with tebuconazole‐containing nanoparticles leached less tebuconazole than wood blocks treated with tebuconazole solutions. The best nanoparticle formulations afforded wood blocks with a biological efficacy comparable to solution‐treated wood block controls in soil jar decay tests.

     

Disk pole location for uncertain systems through convex optimization

In this paper, a necessary and sufficient condition for disk pole location for uncertain continuous or discrete time systems subject to norm-bounded uncertainty is derived. This condition being convex, the control law design is made through convex optimization. The approach adopted follows the quadratic stabilizability philosophy in the problem of pole placement.     

Does discovery-based instruction enhance learning?

Discovery learning approaches to education have recently come under scrutiny (Tobias & Duffy, 2009), with many studies indicating limitations to discovery learning practices. Therefore, 2 meta-analyses were conducted using a sample of 164 studies: The 1st examined the effects of unassisted discovery learning versus explicit instruction, and the 2nd examined the effects of enhanced and/or assisted discovery versus other types of instruction (e.g., explicit, unassisted discovery). Random effects analyses of 580 comparisons revealed that outcomes were favorable for explicit instruction when compared with unassisted discovery under most conditions (d = –0.38, 95% CI [?.44, ?.31]). In contrast, analyses of 360 comparisons revealed that outcomes were favorable for enhanced discovery when compared with other forms of instruction (d = 0.30, 95% CI [.23, .36]). The findings suggest that unassisted discovery does not benefit learners, whereas feedback, worked examples, scaffolding, and elicited explanations do. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Correction to Frazier et al. (2011).

Reports an error in Perceived past, present, and future control and adjustment to stressful life events by Patricia Frazier, Nora Keenan, Samantha Anders, Sulani Perera, Sandra Shallcross and Samuel Hintz (Journal of Personality and Social Psychology, Vol 100[4], 749-765). There is an error on page 758. In the sentence “Present control predicted later event-specific distress in Sample 1(β = .17, p 2011-02001-001.) Perceived control is a central construct in psychology and is key to understanding individual differences in poststress outcomes (Frazier, Berman, & Steward, 2001). The goals of the current studies (using 4 samples of undergraduate students, total N = 1,421) were to examine the relations between different aspects of perceived control and poststress outcomes and to differentiate perceived control over specific events from related constructs (i.e., general control beliefs, coping strategies). To accomplish these goals, we first developed a new measure of perceived past, present, and future control over stressful life events. The data supported the content validity, factor structure, internal consistency and test–retest reliability, and convergent and discriminant validity of the new measure. Consistent with the temporal model of control (Frazier et al., 2001), these 3 forms of control had very different relations with adjustment. Present control was consistently related to lower distress levels in cross-sectional, longitudinal, and prospective analyses. Present control also predicted outcomes beyond the effects of general control beliefs and coping strategies. Past and future control had nonsignificant or positive relations with distress, although future control was associated with better outcomes (i.e., course grades) when the stressor was controllable. Thus, our measure can be used to assess the relations between perceived past, present, and future control and outcomes across a range of stressors. Because the relations between these 3 forms of control and outcomes differ markedly, measures that combine these aspects of control hinder the understanding of the important role of perceived control in adjustment to stress. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Phase transformations in nickel sulphide: Microstructures and mechanisms

Nickel sulphide inclusions are known to be responsible for delayed fracture in tempered glasses due to phase transformation within the inclusion. Microstructural identification of the phase transformation mechanisms in the Ni–S system close to the NiS composition were carried out on a series of partially transformed states. Observations allow to investigate the morphological evolution during transformation, the phase orientation relationships and the first stages of the transformation were investigated by optical microscopy, electron backscatter diffraction, and scanning and transmission electron microscopy. The transformation mechanisms change significantly with the change in sulphur content of the α-NiS phase. Massive transformation is observed for near-stoichiometric composition. For overstoichiometric composition, the transformation is controlled by a long-range diffusion mechanism. The influence of stoichiometry and impurities (Fe) on the microstructural evolution and transformation mechanisms has also been studied.     

Categorisation and Retrieval of Scene Photographs from JPEG Compressed Database

Natural image categorisation and retrieval is the main challenge for image indexing. With the increase of available images and video databases, there is a real need to, first, organise the database automatically according to different semantic groups, and secondly, to take into account these large databases where most of the data is stored in a compressed form. The global distribution of orientation features is a very powerful tool to semantically organise the database into groups, such as outdoor urban scenes, indoor scenes, ‘closed’ landscapes (valleys, mountains, forests, etc.) and ‘open’ landscapes (deserts, fields, beaches, etc.). The constraint of a JPEG compressed database is completely integrated with an efficient implementation of an orientation estimator in the DCT (Discrete Cosinus Transform) domain. The proposed estimator is analysed from different points of view (accuracy and discrimination power). The images are then globally characterised by a set of a few parameters (two or three), allowing a fast scenes categorisation and organisation which is very robust to the quantisation effect, up to a quality factor of 10 in the JPEG format.     

Proneness to shame, proneness to guilt, and psychopathology.

Examined the links between shame, guilt, and psychopathology. In 2 studies, 245 and 234 undergraduates completed the Self-Conscious Affect and Attribution Inventory, the SCL-90, the Beck Depression Inventory, the State-Trait Anxiety Scale, and the Attributional Style Questionnaire. Results failed to support H. B. Lewis's (1971) notion that shame and guilt are differentially related to unique symptom clusters. Shame-proneness was strongly related to psychological maladjustment in general. Guilt-proneness was only moderately related to psychopathology; correlations were ascribable entirely to the shared variance between shame and guilt. Although clearly related to a depressogenic attributional style, shame accounted for substantial variance in depression, above and beyond attributional style. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A reply to Kaplan and Parlow: Minority rights and public health are not mutually exclusive.

It is unfortunate that Kaplan and Parlow (1988) misinterpreted our plea for justice and compassion in balancing the rights of smokers and non-smokers (1987; see record 1989-01264-001) as a blanket endorsement of smokers' rights to expose abstainers to environmental tobacco smoke (ETS). We absolutely do not advocate such a straw man; obviously, innocent third parties have the right to be protected. Kaplan and Parlow's assertion that our position is that "smoking is not a legitimate threat" is totally incorrect. In pointing to the controversy in the scientific literature about the degree of risk associated with ETS, we were not arguing that the risk is non-existent, nor that smokers are entitled to do as they please if others are adversely affected (or even if abstainers simply find ETS esthetically objectionable). Rather, we were emphasizing that the warlike rhetoric, emotionalism, and morally superior stance of the anti-smoking crusade can have a negative impact on the scientific objectivity that ought to guide social policy. The commendability of one's goals is not an excuse for ignoring contrary evidence or failing to examine the evidence for preferred hypotheses as critically as one would the support for unpopular causes. Our concern in our article, which Kaplan and Parlow failed to realize, was with how the rights of both smokers and non-smokers can best be achieved with a minimum of social and personal costs. The intent of our article was to remind readers that, in the past, emotionality and haste on the part of well-intentioned reformers have often been responsible for unnecessary social disruption and trammelling of individual rights--all while failing to achieve their noble goals. We agree with Kaplan and Parlow's position that individuals must be protected from exposure to unwanted ETS and that is the position we took in our article. This, however, can be done without creating greater social problems by trampling on the rights of smokers. (PsycINFO Database Record (c) 2010 APA, all rights reserved)