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Denotational and Algebraic Semantics for Cyber-physical Systems
No full textThe cyber-physical system (CPS) is a dynamic system that contains both continuous and discrete behaviors. It has a wide range of applications in fields such as healthcare equipment, intelligent traffic control and environmental monitoring. However, the combination of continuous physical behaviorand discrete control behavior may complicate the design of systems further. It is of great necessity to give an explicit formal language and its semantics for CPS. In this paper, we elaborate the modeling language for CPS based on our previous work.This language supports shared variables to model the interaction between the physical and the cyber. Additionally, we give it denotational semantics and algebraic semantics, especially focus on the continuous behavior and its composition with the discrete behavior. Throughout this paper, we also present some examples to illustrate the feasibility of the language and its semantics intuitively.Index Terms—Cyber-physical system (CPS), Unifying Theories of Programming (UTP), Denotational semantics, Algebraic semantic
New Reaction Pathways by Integrating Chemo- and Biocatalysis
No full textThe combination of chemo- and biocatalysis in one-pot (integrated catalysis) is a powerful approach to develop new routes towards important products under mild and environmentally benign reaction conditions. Integrated catalysis can improve overall synthetic efficiency and, due to the complementary nature of chemo- and biocatalysts, transformations can be performed, which would be otherwise challenging using a single catalyst. In this review, we highlight recent trends for the combination of enzymes with chemocatalysts. Transition-metal catalysis, organocatalysis, and photoredox catalysis have been combined with different biocatalysts and discussed accordingly. We highlight further how integrated catalysis does not only deliver benign substitutes for known transformations but moreover enables transformations which would be otherwise impossible
THE ROLE OF AGE IN DELAYS TO RHEUMATOLOGICAL CARE IN JUVENILE IDIOPATHIC ARTHRITIS
No full textObjective: To investigate the relationship between age and symptom duration at initial presentation to paediatric rheumatology for JIA. Methods: In children and young people (CYP) enrolled in the Childhood Arthritis Prospective Study pre-March 2018, an association between age at presentation (<5, 5-11 and >11 years) and symptom duration was tested via multivariable linear regression.Results: In 1577 CYP, 5-11 year olds took 3.2 months longer and >11 year olds 6.9 months longer to reach paediatric rheumatology than <5 year olds. Conclusion: Adolescents take longer to reach paediatric rheumatology, potentially impacting their longer-term outcomes given the window of opportunity for JIA. <br/
Vortex collision against static and spinning round cylinders: A lattice Boltzmann study
No full textIn this paper, the flow physics generated by the collision of a vortex dipole that moves against a spinning round cylinder is investigated numerically. Fluid dynamics is predicted by a combined central-moments-based lattice Boltzmann-immersed boundary method. First, the model is validated against well established consolidated benchmark problems, showing very high accuracy properties. Then, results from a comprehensive numerical campaign are presented. A wide set of values of the Reynolds number (Re) is investigated, ranging from 10 to 1000. The cylinder is forced to spin around its centre with different angular velocities, which are obtained by varying the spinning number(Sp) between 0 (corresponding to the static case) and 0.75. The generation of secondary vortices as a consequence of the impact is elucidated and linked to the time evolution of the kinetic energy, enstrophy and hydrodynamic forces. Interestingly, we find that the flow physics changes drastically when Re ≥ 250, independently from the value of Sp. Through a closer look at the vorticity field, we find that the impact creates two primary-secondary structures and a second impingement takes place when Re ≥ 250. Interestingly, the normalised drag force (𝐶𝑑) is found to constantly fluctuates around a mean value. Oscillations are due to the vorticity created by the rotation of the cylinder and are moreemphasised as Sp grows. Specifically, 𝐶𝑑 can achieve marked negative values as a consequence of thevelocity field created by the cylinder during its rotation.<br/
The Winchcombe meteorite – a regolith breccia from a rubble-pile CM chondrite asteroid
No full textThe Winchcombe meteorite is a CM chondrite breccia composed of eight distinct lithological units plus a cataclastic matrix. The degree of aqueous alteration varies between intensely altered CM2.0 and moderately altered CM2.6. Although no lithology dominates, three heavily altered rock types (CM2.1- 2.3) represent >70 area%. Tochilinite-cronstedtite intergrowths (TCIs) are common in several lithologies. Their compositions can vary significantly, even within a single lithology, which can prevent a clear assessment of alteration extent if only TCI composition is considered. We suggest this is due to early alteration under localised geochemical microenvironments creating a diversity of compositions and because later reprocessing was incomplete, leaving a record of the parent body’s fluid history. In Winchcombe fragments of primary accretionary rock are held within a cataclastic matrix (~15 area%). This material is impact-derived fallback debris. Its grain size and texture suggest that the disruption of the original parent asteroid responded by intergranular fracture at grain size
Filament Formation via Collision-induced Magnetic Reconnection – Formation of a Star Cluster
No full textA collision-induced magnetic reconnection (CMR) mechanism was recently proposed to explain the formation of a filament in the Orion A molecular cloud. In this mechanism, a collision between two clouds with antiparallel magnetic fields produces a dense filament due to the magnetic tension of the reconnected fields. The filament contains fiber-like sub-structures and is confined by a helical magnetic field. To show whether the dense filament is capable of forming stars, we use the Arepo code with sink particles to model star formation following the formation of the CMR-filament. First, the CMR-filament formation is confirmed with Arepo. Second, the filament is able to form a star cluster after it collapses along its main axis. Compared to the control model without magnetic fields, the CMR model shows two distinctive features. First, the CMR-cluster is confined to a factor of ∼ 4 smaller volume. The confinement is due to the combination of the helical field and gravity. Second, the CMR model has a factor of ∼ 2 lower star formation rate. The slower star formation is again due to the surface helical field that hinders gas inflow from larger scales. Mass is only supplied to the accreting cluster through streamers
Author response to letter regarding 'Skin and respiratory ill-health attributed to occupational face mask use'
No full textEvaluation of two-year recall of self-reported pesticide exposure among Ugandan smallholder farmers
No full textObjectives: To evaluate smallholder farmers’ recall of pesticide use and exposure determinants over a two-year period in a low-income country context. Methods: The Pesticide Use in Tropical Settings (PESTROP) study in Uganda consists of 302 smallholder farmers who were interviewed in 2017. In the same season in 2019, these farmers were re-questioned concerning pesticide use (e.g., use of active ingredients) and exposure information (e.g., crops, personal protective equipment [PPE], hygienic behaviours) they had previously provided. The extent of recall bias was assessed by comparing responses at follow-up in 2019 with practices and behaviours reported from the baseline interview in 2017.Results: An 84% (n=255) follow-up response rate was attained. We found instances of better recall (e.g., overall agreement >70% and Area Under the Curve (AUC) values >0.7) for the use of some active ingredients, commonly used PPE items, and washing clothes after application, whereas only 13.3% could correctly recall their three major crops. We observed a trend where more individuals reported the use of active ingredients, while fewer reported the use of PPE items, two years later. In general, we found better agreement in the recall of years working with pesticides compared to hours per day or days per week in the field, with no apparent systematic over or under reporting by demographic characteristics. Conclusions: While some of these findings provide consistency with those from high-income countries, more research is needed on recall in poorly educated agriculture communities in low- and middle-income settings to confirm these results
Developing an understanding of sophorolipid synthesis through application of a central composite design model
No full textA key barrier to market penetration for sophorolipid biosurfactants is the ability to improve productivity and utilise alternative feedstocks to reduce the cost of production. To do this, a suitable screening tool is required that is able to model the interactions between media components and alter conditions to maximise productivity. In the following work a central composite design is applied to analyse the effects of altering glucose, rapeseed oil, cornsteep liquor and ammonium sulfate concentrations on sophorolipid production with Starmerella bombicola ATCC 222144 after 168 h. Sophorolipid production was analysed using standard least squares regression and the findings related to the growth (OD600) and broth conditions (glucose, glycerol and oil concentration). An optimum media composition was found that was capable of producing 39.5 g/L sophorolipid. Nitrogen and rapeseed oil sources were found to be significant, linked to their role in growth and substrate supply respectively. Glucose did not demonstrate a significant effect on production despite its importance to biosynthesis and its depletion in the broth within 96 h, instead being replaced by glycerol (via triglyceride breakdown) as the hydrophilic carbon source at the point of glucose depletion. A large dataset was obtained and a regression model with applications towards substrate screening and process optimisation developed
EULAR points to consider when analysing and reporting comparative effectiveness research using observational data in rheumatology
No full textBackgroundComparing treatment effectiveness over time in observational settings is hampered by several major threats, among them confounding and attrition bias. ObjectivesTo develop European Alliance of Associations for Rheumatology (EULAR) points to consider (PtC) when analysing and reporting comparative effectiveness research using observational data in rheumatology. MethodsThe PtC were developed using a three-step process according to the EULAR Standard Operating Procedures. Based on a systematic review of methods currently used in comparative effectiveness studies, the PtC were formulated through two in-person meetings of a multidisciplinary task force and a two-round online Delphi, using expert opinion and a simulation study. Finally, feedback from a larger audience was used to refine the PtC. Mean levels of agreement amongst the task force were calculated. ResultsThree overarching principles and 10 PtC were formulated, addressing, in particular, potential biases relating to attrition or confounding by indication. Building on STROBE guidelines, these PtC insist on the definition of the baseline for analysis and treatment effectiveness. They also focus on the reasons for stopping treatment as an important consideration when assessing effectiveness. Finally, the PtC recommend providing key information on missingness patterns. ConclusionTo improve the reliability of an increasing number of real-world comparative effectiveness studies in rheumatology, special attention is required to reduce potential biases. Adherence to clear recommendations for the analysis and reporting of observational comparative effectiveness studies will improve the trustworthiness of their results.<br/