Gravity and solidity in four great ape species (Gorilla gorilla, Pongo pygmaeus, Pan troglodytes, Pan paniscus): Vertical and horizontal variations of the table task.

Three experiments modeled after infant studies were run on four great ape species (Gorilla gorilla, Pongo pygmaeus, Pan troglodytes, Pan paniscus) to investigate their reasoning about solidity and gravity constraints. The aims were: (a) to find out if great apes are subject to gravity biased search or display sensitivity for object solidity, (b) to check for species differences, and (c) to assess if a gravity hypothesis or more parsimonious explanations best account for failures observed. Results indicate that great apes, unlike monkeys, show no reliable gravity bias, that ape species slightly differ in terms of their performance, and that the errors made are best explained by a gravity account. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Numerical modelling of impact rupture in polysilicon microsystems

A 2D geometrical model for polycrystals was developed in this paper by means of a Voronoi tessellation in which each crystal is assumed to be elastic anisotropic. An implicit–explicit FE dynamic code coupled with an automatic procedure for the introduction of cohesive interface elements with cohesive traction-jump softening laws was used in order to simulate intergranular and transgranular fracture. Accidental drop simulations were performed with the principal aim to capture the maximum acceleration and to simulate local rupture phenomena in MEMS. In order to reduce the excessive problem size, a simplified, decoupled global–local three level multi-scale approach was used.     

Out of plane vs in plane flexural behaviour of thin polysilicon films: Mechanical characterization and application of the Weibull approach

A new MEMS for on-chip mechanical testing of 0.7 μm thick LPCVD polysilicon film has been designed, modelled and fabricated. The polysilicon film is electrostatically loaded under bending until rupture in the out of plane direction. Electrostatical numerical simulations were carried out to evaluate the force developed by the actuator and the capacitance measured by the sensing electrodes while structural numerical simulations were used to compute the stress field into the specimen and its stiffness. Elastic properties and ultimate strength of the material were determined. Comparative studies were performed to investigate the variation of the ultimate strength of the polysilicon film with different loading conditions.     

Dermatologic cross-sensitivity between diltiazem and amlodipine

The experience in an emergency department (ED) during the Gulf War in treating casualties referred to the ED soon after each missile attack is reported. Data were gathered within an 8-hour period of each nationwide alert on all patients who presented to the ED with injuries or complaints directly related to the missile attacks of the Tel Aviv area. One hundred three patients presented with symptoms directly related to the missile attacks. Of 103, 70 suffered from acute psychological reaction, 19 from false autoinjection of atropine, and nine from physical injuries from the explosion. Of the remainder, four had mild symptoms of smoke inhalation, and one had intercurrent myocardial infarction. The missile attacks resulted in a relatively small number of serious injuries. Most of the patients who presented to the ED soon after the missile attacks suffered from either anxiety reaction or false atropin injection.     

Recognizing Impossible Object Relations: Intuitions About Support in Chimpanzees (Pan troglodytes).

Using looking-time measures, the authors examined untrained chimpanzees' (Pan troglodytes) ability to distinguish between adequate and inadequate support. In 3 experiments, the chimpanzees' sensitivity to different support relations between 2 objects was assessed. In each experiment, the chimpanzees saw a possible and an impossible test event, presented as digital video clips. Looking times in the 3 experiments suggest that chimpanzees use amount of contact between 2 objects, but not type of contact, to distinguish between adequate and inadequate support relations. These results indicate that chimpanzees have some intuition about support phenomena but their sensitivity to relational object properties may differ from that of human infants (Homo sapiens) in this domain. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Direct search of feasible region and application to a crashworthy helicopter seat

The paper proposes a novel approach to identify the feasible region for a constrained optimisation problem. In engineering applications the search for the feasible region turns out to be extremely useful in the understanding of the problem as the feasible region defines the portion of the domain where design parameters can be ranged to fulfil the constraints imposed on performances, manufacturing and regulations. The search for the feasible region is not a trivial task as non-convex, irregular and disjointed shapes can be found. The algorithm presented in this paper moves from the above considerations and proposes a recursive feasible-infeasible segment bisection algorithm combined with Support Vector Machine (SVM) techniques to reduce the overall computational effort. The method is discussed and then illustrated by means of three simple analytical test cases in the first part of the paper. A real-world application is finally presented: the search for the survivability zone of a crashworthy helicopter seat under different crash conditions. A finite element model, including an anthropomorphic dummy, is adopted to simulate impacts that are characterised by different deceleration pulses and the proposed algorithm is used to investigate the influence of pulse shape on impact survivability.     

Nucleosome assembly on telomeric sequences

The organization of telomeric chromatin differs from that of bulk chromatin in some peculiar features, such as the unusually short nucleosomal spacing found in vertebrates. Telomeric DNAs are straight, since they consist mostly of 6-8-bp repeated sequences, therefore out of phase with the B DNA period. This feature should be of relevance in nucleosome formation, suggesting the usefulness of studying simple model systems of nucleosome assembly. We reconstituted nucleosomes in vitro, by using purified histone octamers and/or by octamer transfer from chicken erythrocyte nucleosomes, onto telomeric sequences from human, Arabidopsis thaliana, and Saccharomyces cerevisiae. All of these telomeres contain GGG and GGT triplets but are characterized by different repeat lengths (6, 7, and 8 bp). The free energies involved in the association process are the highest among the biological sequences so far assayed, suggesting a main role of DNA flexibility in the assembly of telomeric chromatin. Digestion studies with DNase I, hydroxyl radicals, exonuclease III, and lambda exonuclease indicate that telomeric nucleosomes are characterized by multiple translational positioning without rotational phasing, whereas the telomeric DNA folding around the histone octamer shows the canonical periodicity of about 10.2 bp. The experimental results and a theoretical simulation of DNase I digestion indicate a multiple nucleosome positioning with the periodicity of telomeric DNA. This suggests a main role of local chemical recognition between telomeric sequences and the histone octamer in nucleosome assembly.     

Multiple nucleosome positioning with unique rotational phasing on multimers of the light-responsive elements of pea rbcS-3A and rbcS-3.6 genes: comparison between experimental and theoretical mapping

Nucleosome positioning along two DNA tracts, corresponding to tetramers of the light-responsive elements of pea rbcS-3A and rbcS-3.6 genes, were studied by experimental (exonuclease III mapping and band shift electrophoresis) as well as theoretical methods. Multiple nucleosome positioning with unique rotational phase was derived from both methods in satisfactorily good agreement, if nucleosome dyad axis positions are considered. Theoretical and experimental distributions of nucleosome frequencies appear different, probably on account of DNA sequence dependent digestion kinetics of exonuclease III.