Allelochemical resistance of bald cypress,Taxodium distichum,heartwood to the subterranean termite,Coptotermes formosanus

The heartwood of bald cypress,Taxodium distichum (L.) Rich., resisted feeding attack by the Formosan subterranean termite,Coptotermes formosanus Shiraki. Hexane-extracted heartwood, however, was consumed at > 12 times the amount of sound heartwood eaten. A bioassay usingT. distichum sapwood as a feeding substrate was employed to assess the antitermitic activity of successive hexane, acetone, and methanol extracts of heartwood shavings and isolates derived from the active hexane extract. Two fractions, eluted from the crude hexane extract by liquid chromatography, significantly reduced termite feeding compared to the parent extract, while a third fraction was less active than the original hexane extract. Each fraction contained one major component. All three components were structurally related diterpenes. The two most active heartwood constituents were identified by GC-MS and NMR as ferruginol and manool, while the third and least active, but most prevalent, compound in heartwood was identified as nezukol. Results of bioassays suggest that these allelochemicals act principally as feeding deterrents with accompanying termite mortality due to starvation.     

Comparison of ras-p21 bound to GDP and GTP: differences in protein and ligand dynamics

This paper documents the first essential dynamics analysis of ras protein ligands and of the protein itself, showing important features of their dynamic properties. Essential dynamics analysis of 300 ps of full solvent molecular dynamics simulations revealed differences in structure and dynamics between GDP- and GTP-bound forms of H-ras-p21. Regions in the protein which exhibited a structural shift correspond to the switch regions described previously. Differences in dynamics between H-ras-p21 GDP and H-ras-p21 GTP may be related to interactions of ras with GAP and its receptor and effector. Molecular dynamics of free GDP (in the absence of protein) were performed in water for 2 ns and analysed using essential dynamics. The conformations of GDP and GTP when bound to the protein were compared with free GDP, revealing that the ligands bind to the protein in an energetically unfavourable conformation. GDP and GTP molecules from various other protein crystal structures were also analysed. These ligands adopt similar conformations to those seen in H-ras-p21.      

Analytic center cutting plane method for multiple kernel learning

Multiple Kernel Learning (MKL) is a popular generalization of kernel methods which allows the practitioner to optimize over convex combinations of kernels. We observe that many recent MKL solutions can be cast in the framework of oracle based optimization, and show that they vary in terms of query point generation. The popularity of such methods is because the oracle can fortuitously be implemented as a support vector machine. Motivated by the success of centering approaches in interior point methods, we propose a new approach to optimize the MKL objective based on the analytic center cutting plane method (accpm). Our experimental results show that accpm outperforms state of the art in terms of rate of convergence and robustness. Further analysis sheds some light as to why MKL may not always improve classification accuracy over naive solutions.     

Dual Verbal Elicitation: The Complementary Use of Concurrent and Retrospective Reporting Within a Usability Test

Verbal protocols are the primary tool for understanding users' task-solving behaviors during usability testing. A qualitative study that examined the utility of combining a concurrent and retrospective think-aloud within the same usability test is described. The results indicate that although there was significant overlap between the types of utterances produced during each think-aloud, the retrospective phase produced more verbalizations that were relevant to usability analysis, for example, helpful self-assessments of performance, yielding insights into the impact of encountered difficulties. However, a small number of less desirable utterance types emerged: hypothesising, rationalizing, and forgetting. When used together, both methods contributed to an understanding of usability issues; the concurrent phase yielded more usability issues overall, and the retrospective data improved the understanding of these by (a) reinforcement: users highlighted the impact of an issue on their experience, (b) elaboration: users would provide causal explanations of encountered difficulties, and (c) context: users provided information about the product's context of use.     

Postural support strategies of disabled drivers and the effectiveness of postural support aids

The paper discusses a series of driving trials that were conducted to investigate postural stability of disabled drivers and to assess the effectiveness of a representative sample of support aids. Twenty-three disabled drivers with varying levels of physical disability and seven non disabled drivers participated in the study. The test car was equipped with transducers to measure vehicle velocity and acceleration (longitudinal and lateral), steering wheel movement and torque, and the bracing forces exerted by the driver on the steering wheel. Video cameras were installed to record postural support strategies and displacement of the driver and to record deviation of the car from the specified path. Subjective data regarding driver attitudes and acceptance were also collected through the administration of questionnaires. Findings from the study showed that support aids significantly improved driving performance and reduced physical exertion to maintain an upright driving position for disabled drivers. However, ergonomics design aspects regarding the ease of use and acceptance of the support aids by the end users were identified as obstacles to their sustained use in everyday driving.     

Psychosocial treatment of tinnitus

After all medical and audiological treatments have failed, tinnitus patients often get the advise to "learn to live with it". The aim of psycho-social treatment is assisting patients in the identification of tinnitus aggravating factors and teaching them various coping skills. Treating these problems is primarily recommended for patients suffering from other disorders, even related to tinnitus. Motivation for psycho-social treatment depends on the ability of patients to accept tinnitus as a fundamental fact in their existence.     

Autoradiographic assessment of blood flow heterogeneity in the hamster heart

OBJECTIVE: Provide regional flow measurement in the hearts of small mammals using a new, higher-resolution technique based on the deposition of a molecular marker. METHODS: We determined the instantaneous extraction and retention of the "molecular microsphere" radiolabeled desmethylimipramine in retrogradely perfused hamster hearts. In a separate series of experiments, autoradiography was used to measure regional myocardial deposition densities in hamster hearts of about 0.5 g with spatial area resolution of 16 x 16 microns. RESULTS: Radiolabeled desmethylimipramine is almost 100% extracted during a single transcapillary passage and is retained in the tissue for many minutes. Autoradiographic images demonstrated a spatial flow heterogeneity with standard deviations of 31 +/- 4% of the mean flow (N = 5) in 16 x 16 x 20-micronm3 voxels. This is equivalent to the projections made using fractal relationships from cruder observations obtained with microspheres in the hearts of baboons, sheep, and rabbits. CONCLUSIONS: Autoradiography using a molecular deposition marker provides quantitative information on myocardial flow heterogeneities with resolution at the size of cardiac myocytes. Because the regions resolved are smaller than the volume of regions supplied by single arterioles, the results must slightly exaggerate the true heterogeneity of regional flows.     

The history of sterility in Antiquity. III. The anatomy and physiology of conception in the work of Soranos of Ephesus

Soranos was highly regarded as the first and the most famous gynecologist in the antiquity. In point of fact, Soranos was not really a gynecologist but, he was the first to write a treatise about "gynecology". This work came down to us incomplete. In this study we analyse the conception's theories of Soranos.