Evaluating Decomposition Strategies to Enable Scalable Scheduling for a Real-World Multi-line Steel Scheduling Problem

Steel scheduling is recognised as one of the most difficult real-world scheduling problems. It is characterised by a wide range of operational constraints, variable dependencies and multiple objectives. This paper uses a divide and conquer method to reduce the combinatorial complexity of a real-world multi-line steel scheduling problem. The problem is first decomposed into sub-problems which are solved individually in parallel using parallel branch and bound, then sub-problems are combined to form a solution to the original problem. Three decomposition strategies are compared, specifically: a manual heuristic domain knowledge (DOM) intensive strategy, K-means++ (KM) clustering and Self-organising maps (SOM). Experimental results show that using SOM for decomposition is a promising approach. This paper demonstrates that despite being a highly complex and constrained problem, it is possible to use divide and conquer to achieve potentially good scalability characteristics without significant detriment to the solution quality

Evaluating decomposition strategies to enable scalable scheduling for a real-world multi-line steel scheduling problem

Steel scheduling is recognised as one of the most difficult real-world scheduling problems. It is characterised by a wide range of operational constraints, variable dependencies and multiple objectives. This paper uses a divide and conquer method to reduce the combinatorial complexity of a real-world multi-line steel scheduling problem. The problem is first decomposed into sub-problems which are solved individually in parallel using parallel branch and bound, then sub-problems are combined to form a solution to the original problem. Three decomposition strategies are compared, specifically: a manual heuristic domain knowledge (DOM) intensive strategy, K-means++ (KM) clustering and Self-organising maps (SOM). Experimental results show that using SOM for decomposition is a promising approach. This paper demonstrates that despite being a highly complex and constrained problem, it is possible to use divide and conquer to achieve potentially good scalability characteristics without significant detriment to the solution quality

Use of electrical resistance tomography (ERT) for the detection of biofilm disruption mediated by biosurfactants

© 2018 Institution of Chemical Engineers Inline measurement of biofilms could provide a valuable technology for water, food and bioprocessing industries to improve quality control and avoid contamination. This study presents the first use of electrical resistance tomography (ERT) to detect the removal of biofilms in a pipe. It also tests the effectiveness of sophorolipids and rhamnolipids for the disruption of Bacillus subtilis BBK006 biofilms in an industrial setting. Biofilms were grown on the inner side of a section of 1.5″ test pipe for 5 days using nutrient broth as the culture medium. After the medium was removed the test pipe was incorporated into a cleaning test circuit for the biofilm disruption experiment, where water, sophorolipids (0.4 g L−1) or rhamnolipids (0.4 g L−1) solutions were pumped through respectively for 30 min. ERT was used as an indirect evaluation of the film disruption progression. A cleaning parameter was identified based on zonal boundary averages which successfully measured the extent of biofilm removal

A group II metabotropic glutamate receptor 3 (mGlu3, GRM3) isoform implicated in schizophrenia interacts with canonical mGlu3 and reduces ligand binding

As well as being expressed as a full-length transcript, the group II metabotropic glutamate receptor 3 (GRM3, mGlu3) gene is expressed as an mRNA isoform which lacks exon 4 (GRM3Δ4) and which is predicted to encode a protein with a novel C terminus (called mGlu34). This variant may contribute to the mechanism by which GRM3 acts as a schizophrenia risk gene. However, little is known about the properties or function of mGlu3Δ4. Here, using transiently transfected HEK293T/17 cells, we confirm that GRM3Δ4 cDNA is translated, with mGlu3Δ4 existing as a homodimer as well as a monomer, and localising primarily to cell membranes including the plasma membrane. Co-immunoprecipitation shows that mGlu3Δ4 interacts with canonical mGlu3. mGlu3Δ4 does not bind the mGlu2/3 antagonist [3H]LY341495, but the presence of mGlu3Δ4 reduces binding of [3H]LY341495 to mGlu3, paralleled by a decrease in the abundance of membrane-associated mGlu3. These experiments indicate that mGlu3Δ4 may negatively modulate mGlu3, and thereby impact on the roles of GRM3/mGlu3 in schizophrenia and as a therapeutic target

COVID-19 pandemic on coronary artery and cerebrovascular diseases in Southern Spain: interrupted time series analysis

Objective: Healthcare systems have been put under intense pressure by the COVID-19 pandemic, although some studies have shown a decline in hospital admissions for cardiovascular and cerebrovascular diseases during the first and second wave of the pandemic. In addition, studies analyzing gender and procedural differences are scarce. The present study aimed to determine the impact of the pandemic on hospital admissions for acute myocardial infarction (AMI) and cerebrovascular disease (CVD) in Andalusia (Spain) and analyzed differences by gender and by percutaneous coronary interventions performed. Patients and methods: An interrupted time series analysis of AMI and CVD hospital admissions in Andalusia (Spain) was carried out to measure the impact of the COVID-19 outbreak. AMI and CVD cases admitted daily in public hospitals of Andalusia between January 2018 and December 2020 were included. Results: During the pandemic, significant reductions in AMI [-19%; 95% confidence interval (CI): (-29%, -9%), p<0.001] and CVD [-17%; 95% CI: (-26%, -9%); p<0.01] in daily hospital admissions were observed. Differences were also produced according to the diagnosis (ST-Elevation Myocardial Infarction, Non-ST-Elevation Myocardial Infarction, other AMI and stroke), with a greater reduction in females for AMI and in males for CVD. Although there were more percutaneous coronary interventions during the pandemic, no significant reductions were observed. Conclusions: A decline in AMI and CVD daily hospital admissions during the first and second wave of COVID-19 pandemic was noted. Gender differences were observed, but no clear impact was observed in percutaneous interventions

An anisotropic elastoplastic model for soft clays based on logarithmic contractancy

A new constitutive model for soft structured clays is developed based on an existing model called S-CLAY1S, which is a Cam Clay type model that accounts for anisotropy and destructuration. The new model (E-SCLAY1S) uses the framework of logarithmic contractancy to introduce a new parameter that controls the shape of the yield surface as well as the plastic potential (as an assumed associated flow rule is applied). This new parameter can be used to fit the coefficient of earth pressure at rest, the undrained shear strength or the stiffness under shearing stress paths predicted by the model. The improvement to previous constitutive models that account for soil fabric and bonding is formulated within the contractancy framework such that the model predicts the uniqueness of the critical state line and its slope is independent of the contractancy parameter. Good agreement has been found between the model predictions and published laboratory results for triaxial compression tests. An important finding is that the contractancy parameter, and consequently the shape of the yield surface, seem to change with the degree of anisotropy; however, further study is required to investigate this response. From published data, the yield surface for isotropically consolidated clays seems “bullet” or “almond” shaped, similar to that of the Cam Clay model; while for anisotropically consolidated clays, the yield surface is more elliptical, like a rotated and distorted Modified Cam Clay yield surface

Gad65 is recognized by t-cells, but not by antibodies from nod-mice

Since the 64kDa-protein glutamic acid decarboxylase (GAD) is one of the major autoantigens in T-cell mediated Type 1 diabetes, its relevance as a T-cell antigen needs to be clarified. After isolation of splenic T-cells from non-obese diabetic (NOD) mice, a useful model for human Type 1 diabetes, we found that these T-cells proliferate spontaneously when incubated with human GAD65, but only marginally after incubation with GAD67, both recombinated in the baculovirus system. No effect was observed with non-diabetic NOD mice or with T-cells from H-2 identical NON-NOD-H-2g7 control mice. It has been published previously that NOD mice develop autoantibodies against a 64kDa protein detected with mouse beta cells. In immunoprecipitation experiments with sera from the same NOD mice and 33S-methionine-labelled GAD, no autoantibody binding could be detected. We conclude firstly that GAD65 is an important T-cell antigen which is relevant early in the development of Type 1 diabetes and secondly that there is an antigenic epitope in the human GAD65 molecule recognized by NOD T-cells, but not by NOD autoantibodies precipitating conformational epitopes. Our results therefore provide further evidence that GAD65 is a T-cell antigen in NOD mice, being possibly also involved in very early processes leading to the development of human Type 1 diabetes

A Close Nuclear Black Hole Pair in the Spiral Galaxy NGC 3393

The current picture of galaxy evolution advocates co-evolution of galaxies and their nuclear massive black holes (MBHs), through accretion and merging. Quasar pairs (6,000-300,000 light-years separation) exemplify the first stages of this gravitational interaction. The final stages, through binary MBHs and final collapse with gravitational wave emission, are consistent with the sub-light-year separation MBHs inferred from optical spectra and light-variability of two quasars. The double active nuclei of few nearby galaxies with disrupted morphology and intense star formation (e.g., NGC 6240 and Mkn 463; ~2,400 and ~12,000 light-years separation respectively) demonstrate the importance of major mergers of equal mass spirals in this evolution, leading to an elliptical galaxy, as in the case of the double radio nucleus (~15 light-years separation) elliptical 0402+379. Minor mergers of galaxies with a smaller companion should be a more common occurrence, evolving into spiral galaxies with active MBH pairs, but have hitherto not been seen. Here we report the presence of two active MBHs, separated by ~430 light-years, in the Seyfert galaxy NGC 3393. The regular spiral morphology and predominantly old circum-nuclear stellar population of this galaxy, and the closeness of the MBHs embedded in the bulge, suggest the result of minor merger evolution.Comment: Preprint (not final) version of a paper to appear in Natur

Loss of CXCL12/CXCR4 signalling impacts several aspects of cardiovascular development but does not exacerbate Tbx1 haploinsufficiency

The CXCL12-CXCR4 pathway has crucial roles in stem cell homing and maintenance, neuronal guidance, cancer progression, inflammation, remote-conditioning, cell migration and development. Recently, work in chick suggested that signalling via CXCR4 in neural crest cells (NCCs) has a role in the 22q11.2 deletion syndrome (22q11.2DS), a disorder where haploinsufficiency of the transcription factor TBX1 is responsible for the major structural defects. We tested this idea in mouse models. Our analysis of genes with altered expression in Tbx1 mutant mouse models showed down-regulation of Cxcl12 in pharyngeal surface ectoderm and rostral mesoderm, both tissues with the potential to signal to migrating NCCs. Conditional mutagenesis of Tbx1 in the pharyngeal surface ectoderm is associated with hypo/aplasia of the 4th pharyngeal arch artery (PAA) and interruption of the aortic arch type B (IAA-B), the cardiovascular defect most typical of 22q11.2DS. We therefore analysed constitutive mouse mutants of the ligand (CXCL12) and receptor (CXCR4) components of the pathway, in addition to ectodermal conditionals of Cxcl12 and NCC conditionals of Cxcr4. However, none of these typical 22q11.2DS features were detected in constitutively or conditionally mutant embryos. Instead, duplicated carotid arteries were observed, a phenotype recapitulated in Tie-2Cre (endothelial) conditional knock outs of Cxcr4. Previous studies have demonstrated genetic interaction between signalling pathways and Tbx1 haploinsufficiency e.g. FGF, WNT, SMAD-dependent. We therefore tested for possible epistasis between Tbx1 and the CXCL12 signalling axis by examining Tbx1 and Cxcl12 double heterozygotes as well as Tbx1/Cxcl12/Cxcr4 triple heterozygotes, but failed to identify any exacerbation of the Tbx1 haploinsufficient arch artery phenotype. We conclude that CXCL12 signalling via NCC/CXCR4 has no major role in the genesis of the Tbx1 loss of function phenotype. Instead, the pathway has a distinct effect on remodelling of head vessels and interventricular septation mediated via CXCL12 signalling from the pharyngeal surface ectoderm and second heart field to endothelial cells

Climate warming, marine protected areas and the ocean-scale integrity of coral reef ecosystems

Coral reefs have emerged as one of the ecosystems most vulnerable to climate variation and change. While the contribution of a warming climate to the loss of live coral cover has been well documented across large spatial and temporal scales, the associated effects on fish have not. Here, we respond to recent and repeated calls to assess the importance of local management in conserving coral reefs in the context of global climate change. Such information is important, as coral reef fish assemblages are the most species dense vertebrate communities on earth, contributing critical ecosystem functions and providing crucial ecosystem services to human societies in tropical countries. Our assessment of the impacts of the 1998 mass bleaching event on coral cover, reef structural complexity, and reef associated fishes spans 7 countries, 66 sites and 26 degrees of latitude in the Indian Ocean. Using Bayesian meta-analysis we show that changes in the size structure, diversity and trophic composition of the reef fish community have followed coral declines. Although the ocean scale integrity of these coral reef ecosystems has been lost, it is positive to see the effects are spatially variable at multiple scales, with impacts and vulnerability affected by geography but not management regime. Existing no-take marine protected areas still support high biomass of fish, however they had no positive affect on the ecosystem response to large-scale disturbance. This suggests a need for future conservation and management efforts to identify and protect regional refugia, which should be integrated into existing management frameworks and combined with policies to improve system-wide resilience to climate variation and change