Studies of random demands on network costs

When network demands are uncertain, a planner might design a network based on some nominal set of point‐to‐point demands, and later be faced with a different set of offered demands. To accommodate the offered demands, modification of the network may be required. Given this scenario, it seems natural to question how these modification costs might affect the overall cost. To address such questions, we study the effects of random demands on network costs. In this study, we design a network based on nominal demands, generate random demands based on the nominal demands, and then modify the designed network to carry the random demands. We generate the offered demands randomly from four different distributions. For each demand distribution we perform 300 simulations. This paper describes our observations. This revised version was published online in June 2006 with corrections to the Cover Date.     

Analysis and characterization of ultrawideband scalar volumesources and the fields they radiate

This paper investigates a certain class of three-dimensional (3-D) (volume) sources to the scalar wave equation that are capable of radiating high-amplitude short-duration pulses in a selected (main) direction and low-amplitude long-duration pulses in other directions. Parameterization and characterization of such sources and the fields that they radiate is carried out in both the frequency and time domains and various measures of ultrawideband radiation (transmit mode) performance are evaluated and discussed within both domains. Frequency and time-domain results corresponding to uniformly distributed parallelepiped sources are presented to elucidate the role of the source's space distribution on the radiation performance. These results provide insight about the possibility of optimizing the radiation performance of scalar, ultrawideband volume sources by a proper selection of the space distribution of the source     

Aroma volatile compositions of high- and low-aromatic guava varieties

BACKGROUND: The traditional guava variety cultivated in Israel, ‘Ben Dov’, emits a very strong odour, whereas some newly bred varieties have a mild odour. In this study the aroma profile composition of the high‐aromatic ‘Ben Dov’ variety was compared with those of four new low‐aromatic varieties. RESULTS: Overall, using gas chromatography/mass spectrometry, a total of 30 aroma volatiles were detected in fresh ripe guava fruit: 15 of them were specifically detected only in the high‐aromatic ‘Ben Dov’ variety, 13 were detected in both the high‐ and low‐aromatic varieties and two were detected only in the new low‐aromatic varieties. Interestingly, 11 out of the 15 volatiles specifically detected in ‘Ben Dov’ were esters that contribute sweet, tropical and fruity notes. In contrast, ten out of 13 detected terpenes and two detected aldehydes, contributing green, spicy, herbal and woody notes, were common to both the high‐ and low‐aromatic varieties. CONCLUSION: Based on these findings, it is concluded that accumulation of esters is the main reason why the traditional ‘Ben Dov’ guava variety emits such a strong tropical fruity odour. In contrast, the newly bred low‐aromatic guava varieties did not synthesise esters at all and thus lacked fruity aromatic notes. Overall, the results of this study point out the important role of esters in forming tropical fruity guava odours. Copyright © 2011 Society of Chemical Industry     

Retinoid-X receptor signalling in the developing spinal cord

Retinoids regulate gene expression through the action of retinoic acid receptors (RARs) and retinoid-X receptors (RXRs), which both belong to the family of nuclear hormone receptors. Retinoids are of fundamental importance during development, but it has been difficult to assess the distribution of ligand-activated receptors in vivo. This is particularly the case for RXR, which is a critical unliganded auxiliary protein for several nuclear receptors, including RAR, but its ligand-activated role in vivo remains uncertain. Here we describe an assay in transgenic mice, based on the expression of an effector fusion protein linking the ligand-binding domain of either RXR or RAR to the yeast Gal4 DNA-binding domain, and the in situ detection of ligand-activated effector proteins by using an inducible transgenic lacZ reporter gene. We detect receptor activation in the spinal cord in a pattern that indicates that the receptor functions in the maturation of limb-innervating motor neurons. Our results reveal a specific activation pattern of Gal4-RXR which indicates that RXR is a critical bona fide receptor in the developing spinal cord.     

Discovery and evaluation of a series of 3-acylindole imidazopyridine platelet-activating factor antagonists

Studies conducted with the goal of discovering a second-generation platelet-activating factor (PAF) antagonist have identified a novel class of potent and orally active antagonists which have high aqueous solubility and long duration of action in animal models. The compounds arose from the combination of the lipophilic indole portion of Abbott's first-generation PAF antagonist ABT-299 (2) with the methylimidazopyridine heterocycle moiety of British Biotechnology's BB-882 (1) and possess the positive attributes of both of these clinical candidates. Structure-activity relationship (SAR) studies indicated that modification of the indole and benzoyl spacer of lead compound 7b gave analogues that were more potent, longer-lived, and bioavailable and resulted in the identification of 1-(N, N-dimethylcarbamoyl)-4-ethynyl-3-[3-fluoro-4-[(1H-2-methylimidazo[4,5-c] pyrid-1-yl)methyl]benzoyl]indole hydrochloride (ABT-491, 22 m.HCl) which has been evaluated extensively and is currently in clinical development.     

Ray-mode analysis of complex resonances of an open cavity [radartargets]

Complex resonances furnish valuable inputs for classification of radar signatures from irregularly shaped objects. An important class of targets involves open-ended enclosures with exterior-interior coupling. If the interior has waveguide-like properties, modal expansions can model the wave phenomena there, while ray methods can be employed to account for multiple diffraction at the aperture edges, and for wave interactions around the exterior boundary. By self-consistent ray-mode coupling in a hybrid format, one can construct a global resonance equation whose solutions yield the complex resonant frequencies for the composite object. The importance of evanescent modes and of coupling to nearest neighbor modes is investigated, as is the contribution from low-Q interactions around the external circumference     

An exercise in an interactive geometrical research

We describe how an interactive research with a computer led to a new, simple proof of the classical Mascheroni-Mohr theorem concerning constructions with a compass alone. We then discuss the difficult problem which will face any attempt to attack this theorem using an independent theorem prover.     

Factor analysis of the Marital Interaction Coding System (MICS).

A significant source of confusion in the marital observation area is the proliferation of systems for collapsing microbehavioral codes into categories. This study used an archival data set of 995 couples' videotaped conflict negotiations coded with the Marital Interaction Coding System-IV (MICS). A factor analysis was conducted to provide some empirically based guidance for the formation of coding categories. Four factors emerged for both men and women: Hostility, Constructive Problem Discussion, Humor, and Responsibility Discussion. Suggestions are made for category formation with MICS codes and for the development of a new coding system based on these results. (PsycINFO Database Record (c) 2010 APA, all rights reserved)