10 research outputs found

    Using synchronizing heuristics to construct homing sequences

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    Computing a shortest synchronizing sequence of an automaton is an NP-Hard problem. There are well-known heuristics to find short synchronizing sequences. Finding a shortest homing sequence is also an NP-Hard problem. Unlike existing heuristics to find synchronizing sequences, homing heuristics are not widely studied. In this paper, we discover a relation between synchronizing and homing sequences by creating an automaton called homing automaton. By applying synchronizing heuristics on this automaton we get short homing sequences. Furthermore, we adapt some of the synchronizing heuristics to construct homing sequences

    Effects of small-scale turbulence on the growth of two diatoms of different size in a phosphorus-limited medium

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    15 pages, 7 figures, 5 tables, 1 appendix.-- Issue title: "Workshop on Future Directions in Modelling Physical-Biological Interactions (WKFDPBI)"The effect of turbulence on the nutrient flux towards osmotrophic cells is predicted to be size dependent. This should translate into growth. We experimentally followed and modelled the growth of two marine diatoms of different size (Thalassiosira pseudonana, 6 μm in diameter and Coscinodiscus sp., ca. 109 μm in diameter) under still water and turbulent conditions, using a shaker table. Experiments were done with phosphorus-limited cultures and lasted for ca. 5 days. Turbulence enhanced the growth of Coscinodiscus sp. in agreement with theory but not the growth of T. pseudonana, which was actually slightly lower under turbulence. At the end of the experiments there were about 1.7 times as many Coscinodiscus sp. cells in the turbulent treatment than in the still treatment, while for T. pseudonana almost the same cell concentration was found in both conditions. In addition, the Coscinodiscus sp. cells growing under still conditions presented a higher specific alkaline phosphatase activity than those growing in turbulence which indicates a higher need for phosphorus in the still cultures. A simple dynamic model, based on Michaelis Menten nutrient uptake kinetics, needed nearly no optimisation other than using observed initial conditions of phosphate and cell concentrations. The model showed how an increased nutrient flux towards the cells translates non-linearly into cell growth, most likely by affecting the half-saturation constant (KM). However, since Coscinodiscus sp. experienced significant mortality and cells partially settled to the bottom of the containers, unequivocal support for the size-dependent effect of turbulence on nutrient uptake will require further experiments and more sophisticated modelling. The mechanisms to connect an increased nutrient flux towards cells with population growth and whether this process is size dependent are important in parameterizing the effects of turbulence on marine plankton in coupled physical biological modelsThis work was supported by Spanish Projects TURFI (REN2002-01591/MAR) and VARITEC (CTM2004-04442-C02) and by European Union projects MEDEA (MAS3-CT95-0016) and NTAP (EVK3-CT-2000-00022). This is European Land Ocean Interaction Studies contribution 523/40Peer reviewe

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

    Using structure of automata for faster synchronizing heuristics

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    The problem of finding a synchronizing sequence for an automaton is an interesting problem studied widely in the literature. Finding a shortest synchronizing sequence is an NP-Hard problem. Therefore, there are heuristics to find short synchronizing sequences. Some heuristics work fast but produce long synchronizing sequences, whereas some heuristics work slow but produce relatively shorter synchronizing sequences. In this paper we propose a method for using these heuristics by considering the connectedness of automata. Applying the proposed approach of using these heuristics make the heuristics work faster than their original versions, without sacrificing the quality of the synchronizing sequences

    Silver nanowire loaded poly(ε-caprolactone) nanocomposite fibers as electroactive scaffolds for skeletal muscle regeneration

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    © 2021 Elsevier B.V.Volumetric muscle loss (VML) due to trauma and tumor removal operations affects millions of people every year. Although skeletal muscle has a natural repair mechanism, it cannot provide self-healing above a critical level of VML. In this study, nanocomposite aligned fiber scaffolds as support materials were developed for volumetric skeletal muscle regeneration. For this purpose, silver nanowire (Ag NW) loaded poly(ε-caprolactone) (PCL) nanocomposite fiber scaffolds (PCL-Ag NW) were prepared to mimic the aligned electroactive structure of skeletal muscle and provide topographic and conductive environment to modulate cellular behavior and orientation. A computer-aided rotational wet spinning (RWS) system was designed to produce high-yield fiber scaffolds. Nanocomposite fiber bundles with lengths of 50 cm were fabricated via this computer-aided RWS system. The morphological, chemical, thermal properties and biodegradation profiles of PCL and PCL-Ag NW nanocomposite fibers were characterized in detail. The proliferation behavior and morphology of C2C12 mouse myoblasts were investigated on PCL and PCL-Ag NW nanocomposite fibrous scaffolds with and without electrical stimulation. Significantly enhanced cell proliferation was observed on PCL-Ag NW nanocomposite fibers compared to neat PCL fibers with electrical stimulations of 1.5 V, 3 V and without electrical stimulation

    Comparison of the local effects of different intracameral cefuroxime solutions on rabbit cornea

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    Purpose We aimed to compare the local effects of intracameral cefuroxime diluted in normal saline (SF groups) against those of cefuroxime in balanced salt solution (BSS group) on the cornea of rabbits. Materials and methods Fourteen New Zealand albino rabbits were randomised into two groups. The right eyes of the rabbits in the SF group I were injected intracamerally with 1 mg cefuroxime diluted with 0.1 mL normal saline (n = 7), whereas the right eyes of the BSS group II were injected with 1 mg intracameral cefuroxime diluted with 0.1 mL with balance salt solution, and the left eyes of all rabbits received no treatment group III (control group). Corneal thickness was measured with pachymetry before and 1 week after the injection. Corneal samples were evaluated with light, specular and electron microscopy. Results Mean endothelial cell count was lower in the SF than in the BSS and control groups. Although an increase in corneal thickness was found in both treatment groups, this was not the case for the control group. The corneal endothelium preserved its hexagonal structure in all groups. Although both treatment groups showed a loss of endothelial microvilli, this was more prevalent in the SF group. However, microvilli were preserved in the control group. Dissolution of tight junctions in corneal endothelium was observed in the SF group only. Mitochondrial swelling, coarsening of endoplasmic reticulum, cytoplasmic vacuolisation, and increased endothelial cell sizes were the same in both treatment groups but was not observed in the control group. Thicker and more oedematous corneal stroma were observed in the SF group compared with the BSS and control groups. Conclusion Dilution of intracameral cefuroxime in BSS yielded superior results compared with dilution in normal saline owing to toxicity to the endothelial cells and decline in the endothelial cell number, resulting in intracellular and intercellular morphological changes. BSS or any other solution with proven safety should be used in clinical studies

    Reporting of Safety Events during Anti-VEGF Treatment: Pharmacovigilance in a Noninterventional Trial

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    Aim. The prospective, noninterventional OCEAN study assessed the safety of intravitreal ranibizumab injections for treatment of neovascular age-related macular degeneration, diabetic macular edema, and retinal vein occlusion under real-world conditions in Germany. Methods. Adults receiving ≥1 ranibizumab (0.5 mg) injections were recruited by 369 ophthalmologists and followed for 24 months. Information on adverse events (AEs) was reported by the treating physician or detected by the data management team. Collected information included observed AE, AE start and end date, intensity, causal relationship, outcome, severity, suspected drug, and actions taken. Results. 2,687 AEs were reported for 1,176 of the 5,781 patients who had received a total of 32,621 injections: 27.4% nonserious AEs, 30.3% serious AEs, 27.3% nonserious adverse drug reactions (ADRs), and 15.0% serious ADRs. Most patients reported no AEs (79.7%) or only 1 AE (10.3%). AEs were most commonly reported in the Medical Dictionary for Regulatory Activities (MedDRA) System Organ Class (SOC) Eye disorders (9.4% of patients) and General disorders and administration site conditions (5.8%). The most frequent AEs by MedDRA preferred term (PT) were visual acuity reduced (3.5% of patients), intraocular pressure increased (2.5%), and drug ineffective (2.1%). AEs occurred most frequently after 3 or 4 injections (1,129 of 2,687 AEs). The proportion of AEs in the SOC Eye disorders decreased slightly with increasing number of injections, from 39.8% of events after 1 or 2 injections to 29.1% after 5 or more injections. Rates of the most frequently reported PTs did not show any consistent increase with increasing number of injections. A decrease in overall AE rates was observed over the study course. Conclusions. The results did not raise any new safety concerns for ranibizumab. The findings allow conclusions to be drawn on how pharmacovigilance data can be collected even more effectively in real-world studies to facilitate discussion on benefit-risk ratio

    The clinical features, treatment and prognosis of neutropenic fever and Coronavirus disease 2019 results of the multicentre teos study

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    Abstract This multicentre (22 centres in Turkey) retrospective cohort study aimed to assess the clinical outcomes of patients with neutropenic fever and SARS-CoV-2 positivity. Study period was 15 March 2020–15 August 2021. A total of 170 cases (58 female, aged 59 ± 15.5 years) that fulfilled the inclusion criteria were included in the study. One-month mortality rate (OMM) was 44.8%. The logistic regression analysis showed the following significant variables for the mentioned dependent variables: (i) achieving PCR negativity: receiving a maximum of 5 days of favipiravir (p = 0.005, OR 5.166, 95% CI 1.639–16.280); (ii) need for ICU: receiving glycopeptide therapy at any time during the COVID-19/FEN episode (p = 0.001, OR 6.566, 95% CI 2.137–20.172), the need for mechanical ventilation (p < 0.001, OR 62.042, 95% CI 9.528–404.011); (iii) need for mechanical ventilation: failure to recover from neutropenia (p < 0.001, OR 17.869, 95% CI 3.592–88.907), receiving tocilizumab therapy (p = 0.028, OR 32.227, 95% CI 1.469–707.053), septic shock (p = 0.001, OR 15.4 96% CI 3.164–75.897), and the need for ICU (p < 0.001, OR 91.818, 95% CI 15.360–548.873), (iv) OMM: [mechanical ventilation (p = 0.001, OR 19.041, 95% CI 3.229–112.286) and septic shock (p = 0.010, OR 5.589,95% CI 1.509–20.700)]. Although it includes a relatively limited number of patients, our findings suggest that COVID-19 and FEN are associated with significant mortality and morbidity
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