An algebraic approach to data languages and timed languages

Algebra offers an elegant and powerful approach to understand regular languages and finite automata. Such framework has been notoriously lacking for timed languages and timed automata. We introduce the notion of monoid recognizability for data languages, which includes timed languages as special case, in a way that respects the spirit of the classical situation. We study closure properties and hierarchies in this model and prove that emptiness is decidable under natural hypotheses. Our class of recognizable languages properly includes many families of deterministic timed languages that have been proposed until now, and the same holds for non-deterministic versions.     

Monitoring of multivariable dynamic processes and sensor auditing

Industrial continuous processes are usually operated under closed-loop control, yielding process measurements that are autocorrelated, cross correlated, and collinear. A statistical process monitoring (SPM) method based on state variables is introduced to monitor such processes. The statistical model that describes the in-control variability is based on a canonical variate (CV) state space model. The CV state variables are linear combinations of the past process measurements which explain the variability of the future measurements the most, and they are regarded as the principal dynamic dimensions. A T² statistic based on the CV state variables is utilized for developing the SPM procedure. The CV state variables are also used for monitoring sensor reliability. An experimental application to a high temperature short time (HTST) pasteurization process illustrates the proposed methodology.     

Searching for information in an online public access catalogue (OPAC): the impacts of information search expertise on the use of Boolean operators

Abstract Boolean systems still constitute most of the installed base of online public access catalogues (OPACs) in the French universities even if many studies have shown that Boolean operators are not frequently used by ‘non‐librarian’ users (by contrast with professional librarians). The first study examined the use of Boolean operators by French university students; In the second study, elaborated to evaluate the impact of information search expertise on this use, Boolean operators are explicitly presented and participants were explicitly invited to use them. We assumed that university students would not frequently use the operators in searching, and that even if they were explicitly invited to make use of them. Results obtained with the first study based on transaction logs analyses confirmed that French university students did not frequently use Boolean operators. The impact of information search expertise, analysed in the second study, compared three levels of expertise: Novice (university students), intermediate (future professional librarians), and expert (professional librarians). Results showed that, even if the three groups were invited to use Boolean operators, this use increased significantly with the level of information search expertise. University students, if they manage procedural functions of connectives in natural language, do not always manage the whole set of procedural functions carried by such connectives when used in the documentary language. So, the relevance of presenting explicit Boolean operators in the OPACs when users are ‘non‐librarians’ is questioned.     

Solving the electricity production planning problem by a column generation based heuristic

This paper presents a heuristic method based on column generation for the EDF (Electricité De France) long-term electricity production planning problem proposed as subject of the ROADEF/EURO 2010 Challenge. This is to our knowledge the first-ranked method among those methods based on mathematical programming, and was ranked fourth overall. The problem consists in determining a production plan over the whole time horizon for each thermal power plant of the French electricity company, and for nuclear plants, a schedule of plant outages which are necessary for refueling and maintenance operations. The average cost of the overall outage and production planning, computed over a set of demand scenarios, is to be minimized. The method proceeds in two stages. In the first stage, dates for outages are fixed once for all for each nuclear plant. Data are aggregated with a single average scenario and reduced time steps, and a set-partitioning reformulation of this aggregated problem is solved for fixing outage dates with a heuristic based on column generation. The pricing problem associated with each nuclear plant is a shortest path problem in an appropriately constructed graph. In the second stage, the reload level is determined at each date of an outage, considering now all scenarios. Finally, the production quantities between two outages are optimized for each plant and each scenario by solving independent linear programming problems.     

Synthetic Melanin Acts as Efficient Peptide Carrier in Cancer Vaccine Strategy

We previously reported that a novel peptide vaccine platform, based on synthetic melanin nanoaggregates, triggers strong cytotoxic immune responses and significantly suppresses tumor growth in mice. However, the mechanisms underlying such an efficacy remained poorly described. Herein, we investigated the role of dendritic cells (DCs) in presenting the antigen embedded in the vaccine formulation, as well as the potential stimulatory effect of melanin upon these cells, in vitro by coculture experiments and ELISA/flow cytometry analysis. The vaccine efficiency was evaluated in FLT3-L^−/− mice constitutively deficient in DC1, DC2, and pDCs, in Zbtb46^DTR chimera mice deficient in DC1 and DC2, and in Langerin^DTR mice deficient in dermal DC1 and Langerhans cells. We concluded that DCs, and especially migratory conventional type 1 dendritic cells, seem crucial for mounting the immune response after melanin-based vaccination. We also assessed the protective effect of L-DOPA melanin on peptides from enzymatic digestion, as well as the biodistribution of melanin–peptide nanoaggregates, after subcutaneous injection using [¹⁸F]MEL050 PET imaging in mice. L-DOPA melanin proved to act as an efficient carrier for peptides by fully protecting them from enzymatic degradation. L-DOPA melanin did not display any direct stimulatory effects on dendritic cells in vitro. Using PET imaging, we detected melanin–peptide nanoaggregates up to three weeks after subcutaneous injections within the secondary lymphoid tissues, which could explain the sustained immune response observed (up to 4 months) with this vaccine technology.     

p27kip1 Modulates the Morphology and Phagocytic Activity of Microglia

p27^kip1 is a multifunctional protein that promotes cell cycle exit by blocking the activity of cyclin/cyclin-dependent kinase complexes as well as migration and motility via signaling pathways that converge on the actin and microtubule cytoskeleton. Despite the broad characterization of p27^kip1 function in neural cells, little is known about its relevance in microglia. Here, we studied the role of p27^kip1 in microglia using a combination of in vitro and in situ approaches. While the loss of p27^kip1 did not affect microglial density in the cerebral cortex, it altered their morphological complexity in situ. However, despite the presence of p27^kip1 in microglial processes, as shown by immunofluorescence in cultured cells, loss of p27^kip1 did not change microglial process motility and extension after applying laser-induced brain damage in cortical brain slices. Primary microglia lacking p27^kip1 showed increased phagocytic uptake of synaptosomes, while a cell cycle dead variant negatively affected phagocytosis. These findings indicate that p27^kip1 plays specific roles in microglia.     

TVB-N Correlation with Odor Evaluation and Aerobic Plate Count in Mahi-Mahi (Coryphaena hippurus)

ABSTRACT: Two groups of 6 mahi-mahi fillets, one untreated and the other dipped in a suspension of Morganella morganii , were refrigerated at 7°C and sampled after 0, 2, 4, 6, 8, and 10 d of storage. Results were similar for both groups of fish. Total volatile base-nitrogen (TVB-N) reached 30 mg-N/100 g on d 3, at which time aerobic plate count (APC) reached 10⁶ colony forming units (CFU)/g and odor scores reached 6 on a scale of 1 to 10 (10 very fresh and 1 very spoiled). Good correlation existed between TVB-N and odor intensity (r = 0.84), between TVB-N and the log₁₀ APC (r = 0.71), and between odor and the log₁₀ APC (r = 0.91). These results show that TVB-N can serve as a good indicator of chilled mahi-mahi quality.