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TabID: automatic identification and tabulation of subproblems in constraint models
Get PDFFunding: We thank EPSRC for grants numbered EP/P015638/1, EP/P026842/1, EP/R513386/1, EP/W001977/1, and EP/V027182/1 which have supported the authors at various times while this research was undertaken. Dr Jefferson held a Royal Society University Research Fellowship.The performance of a constraint model can often be improved by converting a subproblem into a single table constraint (referred to as tabulation). Finding subproblems to tabulate is traditionally a manual and time-intensive process, even for expert modellers. This paper presents TabID, an entirely automated method to identify promising subproblems for tabulation in constraint programming. We introduce a diverse set of heuristics designed to identify promising candidates for tabulation, aiming to improve solver performance. These heuristics are intended to encapsulate various factors that contribute to useful tabulation. We also present additional checks to limit the potential drawbacks of suboptimal tabulation. We comprehensively evaluate our approach using benchmark problems from existing literature that previously relied on manual identification by constraint programming experts of constraints to tabulate. We demonstrate that our automated identification and tabulation process achieves comparable, and in some cases improved results. We empirically evaluate the efficacy of our approach on a variety of solvers, including standard CP (Minion and Gecode), clause-learning CP (Chuffed and OR-Tools) and SAT solvers (Kissat). Our findings highlight the substantial potential of fully automated tabulation, suggesting its integration into automated model reformulation tools.Peer reviewe
Economic evaluation alongside a clinical trial of near-to-patient testing for sexually transmitted infections
Get PDFFunding: This trial was funded by an Australian Research Council Industrial Transformation Research Program Hub Grant Project ID IH190100021.Background: Current clinical care for common bacterial STIs (Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and Mycoplasma genitalium (MG)) involves empiric antimicrobial therapy when clients are symptomatic, or if asymptomatic, waiting for laboratory testing and recall if indicated. Near-to-patient testing (NPT) can improve pathogen-specific prescribing and reduce unnecessary or inappropriate antibiotic use in treating sexually transmitted infections (STI) by providing same-day delivery of results and treatment. Methods: We compared the economic cost of NPT to current clinic practice for managing clients with suspected proctitis, non-gonococcal urethritis (NGU), or as an STI contact, from a health provider's perspective. With a microsimulation of 1000 clients, we calculated the cost per client tested and per STI- and pathogen- detected for each testing strategy. Sensitivity analyses were conducted to assess the robustness of the main outcomes. Costs are reported as Australian dollars (2023). Results: In the standard care arm, cost per client tested for proctitis, NGU in men who have sex with men (MSM) and heterosexual men were the highest at 204.23 (95% PI: 202.70-205.75) and 162.36 (95% PI: 161.43-163.28), 149.17 (95% PI: 148.62-149.73), respectively. Using NPT resulted in cost savings of 34.52%, 22.45% and 23.51%, respectively. Among all the testing strategies, substantial difference in cost per client tested between the standard care arm and the NPT arm was observed for contacts of CT or NG, varying from 27.37% to 35.28%. Conclusion: We found that NPT is cost-saving compared with standard clinical care for individuals with STI symptoms and sexual contacts of CT, NG, and MG.Peer reviewe
High centrifugation speed improves recovery of M. tuberculosis and yield of culture
Get PDFFunding: The study was supported by the European and Developing Countries Clinical Trials Partnership (EDCTP) through PanACEA consortium as part of MSc thesis for Mr. Godlove Chaula at the University of Dar es Salaam.Background: We assessed the impact of centrifugation on recovery of Mycobacterium tuberculosis (M.tb). Methods: We used 0.5 McFarland from the 2 weeks M. tb, H37Rv culture and homogenized sputum for our experiments. Samples were decontaminated by 2 % NaOH for 20 min and with PBS for controls. Decontaminated aliquots were centrifuged at 2000×g, 3000×g and 6000×g for 40 min and inoculated on MGIT and LJ media. MGITs were incubated into the BACTEC MGIT 960 Systems following BD manuals and data analyzed on GraphPad Software. Results: The positivity (days) for M. tb, H37Rv in MGIT and LJ decreased from 20.4 to 17.7 and from 47.6 to 26.6 at 2000×g and 6000×g, respectively; P >0.05. For controls, MGIT and LJ positivity (days) decreased from 19 to 10 and from 39.2 to 11.2 at 2000×g and 6000×g, respectively; P >0.05. MGIT positivity was 6(60 %) at 2000×g and 8(80 %) at 6000×g, corresponding to mean (±SD) of 13.7 ±6.7 and 9.06 ±4.6 days, respectively for sputum. LJ positivity was 1(10 %) at 2000×g and 7(70 %) at 6000×g. MGIT contamination for controls (sputum) was over 50 % and 80 % for LJ. Conclusion: Higher centrifugation speed improves yield and sensitivity of TB culture.Peer reviewe
Generalized non-coprime graph of groups
Get PDFFunding: The research work T. Tamizh Chelvam is supported by SERB/CRG/2020/002407 of Science & Engineering Research Board, Government of India.Let G be a finite group with identity e and H ≠ {e} be a subgroup of G. The generalized non-coprime graph Γ(G,H) of G with respect to H is the simple undirected graph with G\{e) as the vertex set and two distinct vertices x and y are adjacent if and only if gcd(|x|,|y|) ≠ 1 and either x∈H or y∈H, where |x| is the order of x∈G. In this paper, we study certain graph theoretical properties of generalized non-coprime graphs of finite groups, concentrating on cyclic groups. More specifically, we obtain necessary and sufficient conditions for the generalized non-coprime graph of a cyclic group to be in the class of stars, paths, triangle-free, complete bipartite, complete, split, claw-free, chordal or perfect graphs. Then we show that widening the class of groups to all finite nilpotent groups gives us no new graphs, but we give as an example of contrasting behaviour the class of EPPO groups (those in which all elements have prime power order). We conclude with a connection to the Gruenberg–Kegel graph.Peer reviewe
Exploring the activity of the putative Δ6-desaturase and its role in bloodstream form life-cycle transitions in Trypanosoma brucei
Get PDFFunding: We would like to thank the Engineering and Physical Sciences Research Council, University of St. Andrews, and the EPSRC Centre for Doctoral Training in Critical Resource Catalysis (CRITICAT) for financial support [Ph.D. studentship to MC; Grant code: EP/L016419/1].Trypanosomatids have been shown to possess an exclusive and finely regulated biosynthetic pathway for de novo synthesis of fatty acids (FAs) and particularly of polyunsaturated fatty acids (PUFAs). The key enzymes for the process of unsaturation are known as desaturases. In this work, we explored the biocatalytic activity of the putative Δ6-desaturase (Tb11.v5.0580) in the native organism T. brucei, whose expression level varies dramatically between life cycle stages. Utilising FA analysis via GC-MS, we were able to elucidate i) via genetic manipulation of the level of expression of Δ6-desaturases in both procyclic (PCF) and bloodstream (BSF) forms of T. brucei and ii) via supplementation of the media with various levels of FA sources, that docosahexaenoic acid (22:6) and/or docosapentaenoic acid (22:5) are the products, while arachidonic acid (20:4) and/or docosatetraenoic acid (22:4) are the substrates of this Δ6-desaturase. Surprisingly, we were able to observe, via lipidomic analysis with ESI-MS/MS, an increase in inositol-phosphoryl ceramide (IPC) in response to the overexpression of Δ6-desaturase in low-fat media in BSF. The formation of IPC is normally only observed in the stumpy and procyclic forms of T. brucei. Therefore, the expression levels of Δ6-desaturases, which increases between BSF, stumpy and PCF, might be involved in the cascade(s) of metabolic events that contributes to these remodelling of the lipid pools and ultimately morphological changes, which are key to the transition between these life-cycle stages. We were in fact able to show that the overexpression of Δ6-desaturase is indeed linked to the expression of protein associated with differentiation (PAD1) in stumpy, and of the upregulation of some proteins and metabolites which are normally upregulated in stumpy and PCF.Peer reviewe
Mosquitoes provide a transmission route between possums and humans for Buruli ulcer in southeastern Australia
Get PDFFunding: This research was funded by the National Health and Medical Research Council of Australia (GNT1152807 and GNT1196396) to E.L.T., S.R.C., P.D.R.J., A.A.H., K.B.G., T.P.S. and S.E.L., Investigator Award (GNT1194325) to T.P.S and Investigator Award (MRF1193727) to K.B.G. The Millersville University Faculty Grant and Sabbatical Leave Grant Program supported J.R.W.Buruli ulcer, a chronic subcutaneous infection caused by Mycobacterium ulcerans, is increasing in prevalence in southeastern Australia. Possums are a local wildlife reservoir for M. ulcerans and, although mosquitoes have been implicated in transmission, it remains unclear how humans acquire infection. We conducted extensive field survey analyses of M. ulcerans prevalence among mosquitoes in the Mornington Peninsula region of southeastern Australia. PCR screening of trapped mosquitoes revealed a significant association between M. ulcerans and Aedes notoscriptus. Spatial scanning statistics revealed overlap between clusters of M. ulcerans-positive Ae. notoscriptus, M. ulcerans-positive possum excreta and Buruli ulcer cases, and metabarcoding analyses showed individual mosquitoes had fed on humans and possums. Bacterial genomic analysis confirmed shared single-nucleotide-polymorphism profiles for M. ulcerans detected in mosquitoes, possum excreta and humans. These findings indicate Ae. notoscriptus probably transmit M. ulcerans in southeastern Australia and highlight mosquito control as a Buruli ulcer prevention measure.Peer reviewe
Topological classification of one-dimensional chiral symmetric interfaces
Get PDFFunding: HMS acknowledges studentship funding from EPSRC under Grant No.EP/W524505/1.We address the topological classification of one-dimensional chiral symmetric interfaces embedded into a two-dimensional substrate. A proof of the validity of a topological classification based on the Green's function by explicit evaluation of the topological invariant is presented. Further, we show that due to entanglement between the in-gap modes and the substrate, the full physics of the substrate that is contained in the Green's function is required. This is done by considering a classification scheme derived from the reduced ground state projector, for which we show that an uncritical handling produces erroneous changes in the topological index due to entanglement driven gap closures. We illustrate our results by applying them to a tight-binding model of a spiral magnetic interface in a -wave superconductor.Peer reviewe
Fragmentary texts and the limits of literary reference : Ennius' Hannibal and Cicero's Pro Balbo in Lucan's Bellum Civile
Get PDFThis article explores some of the complex verbal links between Lucan’s Bellum civile and Ennius’ Annales. Contrary to more expected practices of poetic reference, Lucan’s allusive gestures at Ennian verse (Ann. 234–35 Skutsch) are shown to be aimed simultaneously at Cicero’s Pro Balbo, the speech that reserves the fragmentary lines. They are examples of a curious variant of “window reference” or “two-tier allusion.” Despite Lucan almost certainly having read the lines set within their original context in Ennius’ epic, his poem also activates them as a quotation ensconced within Cicero’s speech. Through allusion to Ennius’ Hannibal, Lucan’s epic uses the Annales to recall its (now largely unknown) depiction of the Carthaginian general. At the same time, it refers to Cicero’s speech as the transmitting source and as a meaningful interpretation of the fragment that provides both a “corrected” characterization and additional content of marked importance to Lucan’s poem.Peer reviewe
The redshift dependence of the inferred H0 in a local void solution to the Hubble tension
Get PDFFunding: UK Science and Technology Facilities Council (ST/V000861/1); Royal Society University Research Fellowship (211046); Deutscher Akademischer Austauschdienst Eastern European Exchange Program.Galaxy number counts suggest that we are located within the Gpc-scale KBC void. The Hubble tension might arise due to gravitationally driven outflow from this void, as explored in detail by Haslbauer et al. We explore how the impact of the void on redshift decays at large distances. We define H0 (z) as the present expansion rate H0 that would be inferred from observations in a narrow redshift range centred on z. We find H0 (z) in three different ways, all of which give similar results. We then compare these results with the observations of Jia et al., who were careful to minimize the impact of correlations between H0 measurements from data in different redshift bins. We find reasonable agreement with their results for the Gaussian and exponential void underdensity profiles, although the agreement is less good in the Maxwell–Boltzmann case. The latter profile causes severe disagreement with the observed bulk flow curve at z 100 Mpc scales.Peer reviewe
NATO, multi-domain operations and the future of the Atlantic alliance
Get PDFThis article discusses the implications of multi-domain operations (MDO) on the North Atlantic Treaty Organization’s (NATO) future. By examining both the historical literature and the antecedents of MDO, the authors identify three salient areas to the successful future conduct of MDO. They also raise concerns regarding the potential challenge posed by MDO to individual NATO countries, the alliance system, as well as its broader competitive strategy. Finally, the article discusses the growing risks posed by emerging enabling technologies and highlights the necessity of comprehensive MDO strategic planning for the Alliance’s future security and effectiveness.Peer reviewe
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