Search results for "large [Cosmology]"
showing 10 items of 272 documents
An ILS-Based Metaheuristic for the Stacker Crane Problem
2012
[EN] In this paper we propose a metaheuristic algorithm for the Stacker Crane Problem. This is an NP-hard arc routing problem whose name derives from the practical problem of operating a crane. Here we present a formulation and a lower bound for this problem and propose a metaheuristic algorithm based on the combination of a Multi-start and an Iterated Local Search procedures. Computational results on a large set of instances are presented.
On the nature of a shell of young stars in the outskirts of the Small Magellanic Cloud
2019
Understanding the evolutionary history of the Magellanic Clouds requires an in-depth exploration and characterization of the stellar content in their outer regions, which ultimately are key to tracing the epochs and nature of past interactions. We present new deep images of a shell-like over-density of stars in the outskirts of the Small Magellanic Cloud (SMC). The shell, also detected in photographic plates dating back to the fifties, is located at ~1.9 degr from the center of the SMC in the north-east direction.The structure and stellar content of this feature were studied with multi-band, optical data from the Survey of the MAgellanic Stellar History (SMASH) carried out with the Dark Ene…
Glutamate 270 plays an essential role in K+-activation and domain closure ofThermus thermophilusisopropylmalate dehydrogenase
2014
The mutant E270A of Thermus thermophilus 3-isopropylmalate dehydrogenase exhibits largely reduced (∼1%) catalytic activity and negligible activation by K(+) compared to the wild-type enzyme. A 3-4 kcal/mol increase in the activation energy of the catalysed reaction upon this mutation could also be predicted by QM/MM calculations. In the X-ray structure of the E270A mutant a water molecule was observed to take the place of K(+). SAXS and FRET experiments revealed the essential role of E270 in stabilisation of the active domain-closed conformation of the enzyme. In addition, E270 seems to position K(+) into close proximity of the nicotinamide ring of NAD(+) and the electron-withdrawing effect…
Accurate Treatment of Large Supramolecular Complexes by Double-Hybrid Density Functionals Coupled with Nonlocal van der Waals Corrections.
2015
In this work, we present a thorough assessment of the performance of some representative double-hybrid density functionals (revPBE0-DH-NL and B2PLYP-NL) as well as their parent hybrid and GGA counterparts, in combination with the most modern version of the nonlocal (NL) van der Waals correction to describe very large weakly interacting molecular systems dominated by noncovalent interactions. Prior to the assessment, an accurate and homogeneous set of reference interaction energies was computed for the supramolecular complexes constituting the L7 and S12L data sets by using the novel, precise, and efficient DLPNO-CCSD(T) method at the complete basis set limit (CBS). The correction of the bas…
Stability and surgical complications of tooth-borne and bone-borne appliances in surgical assisted rapid maxillary expansion: a systematic review
2021
The objective of this systematic review was to evaluate the stability and complications of tooth-borne (TB), bone-borne (BB) and hybrid (TB-BB) appliances in surgically assisted rapid maxillary expansion (SARME). Database searches were conducted (PubMed, Embase, Cochrane Library and SciELO), as well as a grey literature search (Google Scholar) and hand searches of reference lists. Forty-six articles were included after study selection (κ=0.854). After eligibility assessment, 16 articles and one article from the grey literature were processed (κ=0.866) and six articles were selected by hand searching, for a total of 23 articles included. Regarding stability, TB appliances showed width relaps…
General Equilibrium Models of Monopolistic Competition: CRRA Versus CARA
2005
We analyze a class of "large group" Chamberlinian monopolistic competition models using multiplicatively quasi-separable (MQS) and additively quasi-separable (AQS) functions. We first prove that the MQS and AQS functions are equivalent to the "constant relative risk aversion" (CRRA) and "constant absolute risk aversion" (CARA) classes of functions, respectively. Whereas both approaches allow for closed-form solutions, only the AQS functions yield profit-maximizing prices that decrease in the mass of competing firms. We then characterize the equilibrium in both cases and discuss some possible applications of the AQS framework to trade, growth, and development.
Use of Quantitative Morphological Analysis Combined with a Large Sample Size for Estimating Morphological Variability in a Case Study of Armoured Mit…
2015
Abstract The morphology of Oribatida and similar little-known groups of organisms varies considerably, which complicates morphological analysis (e.g. species descriptions). Qualitative analyses have been carried out mostly on a small number of individuals (n < 25). There is lack of studies dealing with mechanisms of how that variation can change in relation to sample size and insufficient discussion on whether qualitative or quantitative analysis is more appropriate for description of morphological variability. A total of 500 adult Carabodes subarcticus Trägårdh, 1902 Oribatida were collected from a local population. Six qualitative and six quantitative traits were characterised using li…
A CAPWAP-Compliant Solution for Radio Resource Management in Large-Scale 802.11 WLAN
2007
Recently, the impressive success of the IEEE 802.11 WLAN technology has dramatically changed the role of the wireless connectivity provisioning. Born as a wireless extension of small office or home networks, todays the WLANs are getting more and more popular as a large, even metropolitan, area networks. The deployment of large-scale WLANs has some critical issues, because of the lack of coordinated management functionalities among the network nodes. In this paper we briefly describe the CAPWAP architectural solution, for centralizing some control and maintenance functionalities in large scale WLAN, by guaranteeing the interoperability between network nodes provided by different vendors. We …
Very high specific activity erbium 169Er production for potential receptor-targeted radiotherapy
2019
Erbium 169Er is one of the most interesting radiolanthanides for new potential receptor-targeted β− therapy applications due to its low energy β− emissions, very low intensity ɣ rays and the possibility to use 68Ga or 44Sc as companion for diagnostic in a theranostics approach. Currently it can be produced in reactors through the neutron activation of highly enriched 168Er. The low specific activity of the produced carrier-added 169Er is limiting its use for receptor-targeted therapy. Nonetheless it is used for radiosynoviorthesis of small joints. The aim of this work is to develop a new large-scale production method for the supply of very high specific activity 169Er. Highly enriched 168Er…
Superheavy-element research
1979
The existence of an island of relatively stable elements beyond the present Periodic Table has been predicted by theoretical extrapolations of nuclear properties. During the past 12 years vigorous efforts have been made to discover these superheavy elements in nature and to produce them by nuclear reactions.