Many important problems in cell biology require the consideration of dense nonlinear interactions between functional modules. The requirement of computer simulation for the understanding of cellular ...processes is now widely accepted, and a variety of modelling frameworks have been designed to meet this need. Here, we present a novel public release of the Gene Interaction Network simulation suite (
GINsim), a software designed for the qualitative modelling and analysis of regulatory networks. The main functionalities of
GINsim are illustrated through the analysis of a logical model for the core network controlling the fission yeast cell cycle. The last public release of
GINsim (version 2.3), as well as development versions, can be downloaded from the dedicated website (
http://gin.univ-mrs.fr/GINsim/), which further includes a model library, along with detailed tutorial and user manual.
Two case studies concerning failure analysis on open via defects are presented in this paper. Both of them were performed on a mixed-signal product for automotive application and showed several ...analysis techniques used to find defective net. First example showed the use of well-known Emission Microscopy (EMMI) in combination with advanced electrical setup to highlight floating net. This case study showed the need to thoroughly interpret EMMI signatures in combination with extensive setup investigation in order to solve an analysis with a complex failure mode. Second example showed an innovative use of Dynamic Thermal Laser Stimulation to identify a floating gate.
•Case study from defect localization to root cause understanding•Complex and unstable failure mode caused by floating nets•Emission Microscopy to detect latch oscillations induced by open via•Innovative use of Dynamic Thermal Laser Stimulation to identify a floating gate
Brazil's response to the HIV/AIDS epidemic was characterised by an innovative alliance of governmental and non-governmental actors inspired by a strong progressive tradition in public health. Brazil ...eventually moved to decentralise HIV/AIDS programmes to its states and cities, a policy endorsed and supported financially by the World Bank as consistent with the mix of public and private elements central to the country's HIV/AIDS strategy. However, decentralisation has not provided the results anticipated. Through interviews with key informants, government officials and patient advocates as well as observation of treatment sites, we outline how the shift of administration and resources to state and municipal bodies operated in practice. The Bank promoted decentralisation as an uncontroversial technical matter, and its programmatic guidelines implied that the nonprofit sector would be strengthened by it. However, instead of bringing HIV/AIDS policy closer to the grassroots, decentralisation has undermined the country's early work and opened the door to a rejuvenated epidemic by empowering unsympathetic local elites, marginalising the human rights focus, and removing federal oversight. Its experience holds crucial lessons for developing countries facing similar conditions.
This article addresses one of the major constraints imposed by additive manufacturing processes on shape optimization problems – that of overhangs, i.e. large regions hanging over void without ...sufficient support from the lower structure. After revisiting the ‘classical’ geometric criteria used in the literature, based on the angle between the structural boundary and the build direction, we propose a new mechanical constraint functional, which mimics the layer by layer construction process featured by additive manufacturing technologies, and thereby appeals to the physical origin of the difficulties caused by overhangs. This constraint, as well as some variants, is precisely defined; their shape derivatives are computed in the sense of Hadamard's method, and numerical strategies are extensively discussed, in two and three space dimensions, to efficiently deal with the appearance of overhang features in the course of shape optimization processes.
•We present a new constraint on shapes, based on a model for additive manufacturing.•We provide efficient methods for computing this constraint and its shape derivative.•We explain why geometric criteria are not satisfactory to prevent overhang features.•We discuss several numerical examples, in 2 and 3 dimensions.
We report evidence for the simultaneous production of J/ψ and ϒ mesons in 8.1 fb^{-1} of data collected at sqrts=1.96 TeV by the D0 experiment at the Fermilab ppover ¯ Tevatron Collider. Events ...with these characteristics are expected to be produced predominantly by gluon-gluon interactions. In this analysis, we extract the effective cross section characterizing the initial parton spatial distribution, σ_{eff}=2.2±0.7(stat)±0.9(syst) mb.
From the 16 laboratories participating in CMX-4, three laboratories (Buonarroti, Matisse, and Pollock) have utilized secondary ion mass spectrometry (SIMS) for the characterization of the samples. ...SIMS allows analysis of samples on micrometric scales and thus it can be used for the analysis of individual particles. The aim of the SIMS analysis was to identify any possible heterogeneity of isotopic composition of the uranium, and to make a quantitative characterization of this heterogeneity to look for unique identifiers of the material. The outcome of the SIMS analysis from the three laboratories is described and discussed in this paper.
We compute the rotational quenching rates of the first 81 rotational levels of ortho- and para-H2CO in collision with ortho- and para-H2, for a temperature range of 10-300 K. We make use of the ...quantum close-coupling and coupled-state scattering methods combined with the high accuracy potential energy surface of Troscompt et al. Rates are significantly different from the scaled rates of H2CO in collision with He; consequently, critical densities are notably lower. We compare a full close-coupling computation of pressure broadening cross-sections with experimental data and show that our results are compatible with the low-temperature measurements of Mengel & De Lucia, for a spin temperature of H2 around 50 K.
Context. The recent unexpected detection of terrestrial complex organic molecules in the cold (~10 K) gas has cast doubts on the commonly accepted formation mechanisms of these species. Standard ...gas-phase mechanisms are inefficient and tend to underproduce these molecules, and many of the key reactions involved are unconstrained. Grain-surface mechanisms, which were presented as a viable alternative, suffer from the fact that they rely on grain surface diffusion of heavy radicals, which is not possible thermally at very low temperatures. Aims. One of the simplest terrestrial complex organic molecules, methanol is believed to form on cold grain surfaces following from successive H atom additions on CO. Unlike heavier species, H atoms are very mobile on grain surfaces even at 10 K. Intermediate species involved in grain surface methanol formation by CO hydrogenation are the radicals HCO and CH3O, as well as the stable species formaldehyde H2CO. These radicals are thought to be precursors of complex organic molecules on grain surfaces. Methods. We present new observations of the HCO and CH3O radicals in a sample of prestellar cores and carry out an analysis of the abundances of the species HCO, H2CO, CH3O, and CH3OH, which represent the various stages of grain-surface hydrogenation of CO to CH3OH. Results. The abundance ratios between the various intermediate species in the hydrogenation reaction of CO on grains are similar in all sources of our sample, HCO:H2CO:CH3O:CH3OH ~10:100:1:100. We argue that these ratios may not be representative of the primordial abundances on the grains but, rather, suggest that the radicals HCO and CH3O are gas-phase products of the precursors H2CO and CH3OH, respectively. Various gas-phase pathways are considered, including neutral-neutral and ion-molecule reactions, and simple estimates of HCO and CH3O abundances are compared to the observations. Critical reaction rate constants, branching ratios, and intermediate species are finally identified.
Context. Complex organic molecules (COMs) have long been detected in the interstellar medium, especially in hot cores and in the hot corinos of low-mass protostars. Their formation routes however ...remain uncertain. Both warm gas-phase reactions and warm grain-surface reactions have been invoked to account for their presence in low-mass protostars. In this latter scheme, COMs result from radical-radical reactions on the grains as radicals become mobile when the nascent protostar warms up its surroundings and the resulting molecules are subsequently desorbed into the gas phase at higher temperatures. Aims. Prestellar cores are the direct precursors of low-mass protostars and offer a unique opportunity to study the formation of COMs before the warm-up phase. Their very low temperatures (≤ 10 K) and the absence of any heating source or outflow exclude any efficient warm gas phase or warm dust chemistry, so that the presence of COMs in prestellar cores would have to originate from non-thermal chemical processes. Methods. We used the IRAM 30 m telescope to look for four O-bearing COMs (acetaldehyde CH3CHO, dimethyl ether CH3OCH3, methyl formate CH3OCHO, and ketene CH2CO) in the prestellar core L1689B. Results. We report the unambiguous detection of all four molecules in the cold gas phase of L1689B. These detections support the role played by non-thermal (possibly photolytic) processes in COM formation and desorption, though the presence of dimethyl ether is so far unexplained by current grain formation scenarios. The data show univocally that COM synthesis has already started at the prestellar stage and suggests at least part of the COMs detected in hot corinos have a prestellar origin.
•Natural antioxidants encapsulated in nanoliposomes showed very high particle stability.•Liposomes loaded with the polyphenolic extract showed greater antioxidant properties.•Freeze-dried liposomes ...provided gel integrity and storage stability in surimi gels.•Antioxidant activity was kept in the surimi gels after in vitro gastrointestinal digestion.
Three antioxidant extracts (collagen hydrolysate, pomegranate peel extract, shrimp lipid extract) were encapsulated in soy phosphatidylcholine liposomes with the addition of glycerol. The particle size of the fresh liposomes ranged from 75.7 to 81.0 nm and zeta potential from -64.6 to −88.2 mV. Freeze-drying increased particle size (199–283 nm), and slightly decreased zeta potential. The lyophilized liposomes were incorporated in squid surimi gels at 10.5% concentration. An alternative functional formulation was also prepared by adding 2% of non-encapsulated bioactive extract. The gels were characterized in terms of colour, texture and oxidative stability (TBARS) after processing and also after frozen storage. The incorporation of the freeze-dried liposomes caused a slight decrease in gel strength and contributed to maintaining the stability of the gels during long-term frozen storage. The antioxidant properties of the bioactive extracts, liposomes and in vitro digested surimi gels were determined.
PDF
