The societal benefits of numerical weather prediction (NWP) forecasts are most evident in populated areas. An urban representation within NWP models should provide improved forecast accuracy. Here, ...we present the preliminary implementation of an urban scheme within the Integrated Forecasting System (IFS) using a simplified single‐layer urban canopy model. The scheme makes assumptions of canyon geometry and considers fluxes from roads, walls, and roofs. Temperature observations were used to optimize single‐column model (SCM) parameters using the Gauss‐Newton method. Observation comparisons over six European cities, show a 2‐m temperature root‐mean‐squared error reduction from 1.85 to 1.75 K with the urban scheme. Optimized parameters were used globally at kilometric scale in a land surface model. A sensitivity experiment assuming a 100% urban world showed spatially averaged northern hemisphere 2‐m temperatures increased by 0.54 K (January) and 0.42 K (July) at night caused by changes in the albedo, emissivity, roughness, and thermal and hydrological properties. Global ∼1‐km resolution simulations using ancillary urban mapping information produce an urban heat island effect over major and minor conurbations. Only major conurbations were well represented at ∼9‐km resolution. Results from SCM simulations show a heightening of the planetary boundary layer over city sites, with the largest enhancements occurring at night in July (84 ± 48 m) caused by an increased sensible heat flux. These initial developments show the importance of a high‐resolution urban representation within NWP models. Improved parameterization and mapping will enable an online representation of energy, water, and trace gas fluxes over residential areas.
Plain Language Summary
Urban areas make up only a small fraction of the Earth's surface; however, they are home to over 50% of the world's population. In these areas a phenomenon known as the urban heat island effect causes increased temperatures due to human activities, an effect often missing in weather forecasts. Forecasts, generated using computer models, consider not only the atmosphere but also the role of the land surface on the weather above. Typically these models do not include an urban map, so they miss key urban processes. We introduced a representation of urban areas to the model of the European Center for Medium‐Range Weather Forecasts. We considered several ways in which the urban environment interacts with the weather, including through changes in heat storage and treatment of rainfall. We find these developments result in a more accurate model forecast over six European cities. The model accurately predicts the increased heating observed over cities at night and some of the observed changes in the atmosphere. Future work should continue to improve the urban representation in weather and air quality/greenhouse gas models by implementing an urban scheme in operational forecasts.
Key Points
An urban scheme has been introduced and optimized within the ECMWF IFS single‐column and surface‐only model
Assuming an urban world, average nighttime 2‐m temperatures increased for January (0.54 K) and July (0.42 K) in a surface only simulation
Using realistic urban cover for eight cities, PBL height in July increases by an average of 66 and 84 m for the day and night, respectively
Little is known about the effects of small doses of dexamethasone used for the prophylaxis of postoperative nausea and vomiting on the innate host response.
We studied the influence of dexamethasone ...4 mg on the perioperative plasma concentrations of interleukins after laparoscopic cholecystectomy. We hypothesised that there would be differences in pro-inflammatory interleukin concentrations in patients who received dexamethasone.
A randomised controlled study.
University hospital.
Forty-six patients undergoing laparoscopic cholecystectomy under total intravenous anaesthesia were allocated randomly into one of two study groups; 42 patients completed the study.
Patients in group 1 (dexamethasone, n = 22) received dexamethasone 4 mg and group 2 (n = 20) acted as controls.
Plasma levels of tumour necrosis factor alpha and interleukins 1β, 6, 8, 10 and 13 were measured before anaesthesia, before surgery and 2 and 24 h after surgery. The frequency and number of episodes of postoperative nausea and vomiting were recorded.
Areas under the curve of the percentage variation of interleukins 6 and 8 were significantly lower in the dexamethasone group. There were no significant differences between groups in the areas under the curve for tumour necrosis factor alpha and interleukins 1β, 10 and 13. The greatest variation in interleukin concentrations was 2 h postoperatively, when the concentration of interleukin 6 was greater in the control group, whereas the concentration of interleukin 10 was higher in the dexamethasone group. Twenty-four hours after surgery, only the concentration of interleukin 6 remained significantly increased in both groups (P = 0.001 and P = 0.002, respectively). There were no significant differences between groups in respect of postoperative nausea and vomiting.
Prophylactic dexamethasone given before laparoscopic cholecystectomy produced a significant decrease in concentrations of interleukins 6 and 8. Further studies are needed to investigate the clinical implications of these findings.
Whether inflammatory responses to surgery are comparably activated during total intravenous anesthesia (TIVA) and during volatile anesthesia remains unclear. We thus compared the perioperative ...effects of TIVA and isoflurane anesthesia on plasma concentrations of proinflammatory and anti-inflammatory interleukins and cell adhesion molecules.
Patients having laparoscopic cholecystectomies were randomly allocated to two groups: 44 were assigned to TIVA and 44 to isoflurane anesthesia. IL-1β, IL-6, IL-8, IL-10, IL-13, and the cellular adhesion molecules intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 were determined preoperatively, before incision, and at 2 and 24 hours postoperatively. Our primary outcomes were area-under-the-curve cytokine and adhesion molecule concentrations over 24 postoperative hours.
The only statistically significant difference in area-under-the-curve concentrations was for IL-6, which was greater in patients given isoflurane:78 (95% confidence interval (CI): 52 to 109) pg/ml versus 33 (22 to 50) pg/ml, P= 0.006. Two hours after surgery, IL-6 was significantly greater than baseline in patients assigned to isoflurane: 47 (95% CI: 4 to 216, P<0.001) pg/ml versus 18 (95%CI: 4 to 374, P<0.001) pg/ml in the TIVA group. In contrast, IL-10 was significantly greater in patients assigned to TIVA: 20 (95% CI: 2 to 140, P<0.001) pg/ml versus 12 (95% CI: 3 to 126, P<0.001) pg/ml. By 24 hours after surgery, concentrations were generally similar between study groups and similar to baseline values.
The only biomarker whose postoperative area-under-the-curve concentrations differed significantly as a function of anesthetic management was IL-6. Two hours after surgery, IL-6 concentrations were significantly greater in patients given isoflurane than TIVA. However, the differences were modest and seem unlikely to prove clinically important. Further studies are needed.
Polydopamine (PDA) formed by the oxidation of dopamine is an important polymer, in particular, for coating various surfaces. It is composed of dihydroxyindole, indoledione, and dopamine units, which ...are assumed to be covalently linked. Although PDA has been applied in a manifold way, its structure is still under discussion. Similarities have been observed in melanins/eumelanins as naturally occurring, deeply colored polymer pigments derived from L-DOPA. Recently, an alternative structure was proposed for PDA wherein dihydroxyindoline, indolinedione, and eventually dopamine units are not covalently linked to each other but are held together by hydrogen bonding between oxygen atoms or π stacking. In this study, we show that this structural proposal is very unlikely to occur taking into account unambiguous results obtained by different analytical methods, among them (13)C CPPI MAS NMR (cross-polarization polarization-inversion magic angle spinning NMR), (1)H MAS NMR (magic angle spinning NMR), and ES-HRMS (electrospray ionization high-resolution mass spectrometry) for the first time in addition to XPS (X-ray photoelectron spectroscopy) and FTIR spectroscopy. The results give rise to a verified structural assignment of PDA wherein dihydroxyindole and indoledione units with different degrees of (un)saturation are covalently linked by C-C bonds between their benzene rings. Furthermore, proof of open-chain (dopamine) monomer units in PDA is provided. Advanced DFT calculations imply the arrangements of several PDA chains preferably by quinone-hydroquinone-type interactions in a parallel or antiparallel manner. From all of these results, a number of hypotheses published before could be experimentally supported or were found to be contradictory, thus leading to a better understanding of the PDA structure.
Modern multicore and manycore processors exhibit multiple levels of parallelism through a wide range of architectural features such as SIMD for data parallel execution or threads for core ...parallelism. The exploitation of multi-level parallelism is therefore crucial for achieving superior performance on current and future processors. This paper presents the performance tuning of a multiblock CFD solver on Intel SandyBridge and Haswell multicore CPUs and the Intel Xeon Phi Knights Corner coprocessor. Code optimisations have been applied on two computational kernels exhibiting different computational patterns: the update of flow variables and the evaluation of the Roe numerical fluxes. We discuss at great length the code transformations required for achieving efficient SIMD computations for both kernels across the selected devices including SIMD shuffles and transpositions for flux stencil computations and global memory transformations. Core parallelism is expressed through threading based on a number of domain decomposition techniques together with optimisations pertaining to alleviating NUMA effects found in multi-socket compute nodes. Results are correlated with the Roofline performance model in order to assert their efficiency for each distinct architecture. We report significant speedups for single thread execution across both kernels: 2-5X on the multicore CPUs and 14-23X on the Xeon Phi coprocessor. Computations at full node and chip concurrency deliver a factor of three speedup on the multicore processors and up to 24X on the Xeon Phi manycore coprocessor.
This paper presents a number of optimisations for improving the performance of unstructured computational fluid dynamics codes on multicore and manycore architectures such as the Intel Sandy Bridge, ...Broadwell and Skylake CPUs and the Intel Xeon Phi Knights Corner and Knights Landing manycore processors. We discuss and demonstrate their implementation in two distinct classes of computational kernels: face-based loops represented by the computation of fluxes and cell-based loops representing updates to state vectors. We present the importance of making efficient use of the underlying vector units in both classes of computational kernels with special emphasis on the changes required for vectorising face-based loops and their intrinsic indirect and irregular access patterns. We demonstrate the advantage of different data layouts for cell-centred as well as face data structures and architectural specific optimisations for improving the performance of gather and scatter operations which are prevalent in unstructured mesh applications. The implementation of a software prefetching strategy based on auto-tuning is also shown along with an empirical evaluation on the importance of multithreading for in-order architectures such as Knights Corner. We explore the various memory modes available on the Intel Xeon Phi Knights Landing architecture and present an approach whereby both traditional DRAM as well as MCDRAM interfaces are exploited for maximum performance. We obtain significant full application speed-ups between 2.8 and 3X across the multicore CPUs in two-socket node configurations, 8.6X on the Intel Xeon Phi Knights Corner coprocessor and 5.6X on the Intel Xeon Phi Knights Landing processor in an unstructured finite volume CFD code representative in size and complexity to an industrial application.
Program Title: some_opt_for_unstructured_cfd
Program Files doi:http://dx.doi.org/10.17632/zyh2zkf3jw.1
Licensing provisions: GNU General Public License 3 (GPL)
Programming language: C/C++
Nature of problem: The solution of fluid flow problems in the vicinity of complex geometries mandates the utilisation of unstructured grids. However, this flexibility of unstructured mesh methods in dealing with complicated geometries comes at a cost of increased difficulty in extracting high performance out of modern processors. We provide implementations for a number of optimisations useful for improving the performance of unstructured CFD codes on modern multicore and manycore architectures.
Solution method: grid renumbering via Reverse Cuthill–Mckee, code transformations necessary for enabling vectorisation, face colouring/reordering for removing dependencies at the face end-points when accumulating residuals, data layout transformations for reducing cache misses, hand-tuned gather and scatter primitives for in-register transpositions, software prefetching via auto-tuning and multithreading for exploiting SMT features of modern processors.
Yellow laccases lack the typical blue type 1 Cu absorption band around 600 nm; however, multi-copper oxidases with laccase properties have been reported. We provide the first evidence that the yellow ...laccase isolated from Sclerotinia sclerotiorum is obtained from a blue form by covalent, but nevertheless reversible modification with a phenolic product. After separating the phenolics from the extracellular medium, a typical blue laccase is obtained. With ABTS as model substrate for this blue enzyme, a non-natural purple adduct is formed with a spectrum nearly identical to that of the 1:1 adduct of an ABTS radical and Tyr. This modification significantly increases the stability and substrate affinity of the enzyme, not by acting primarily as bound mediator, but by structural changes that also alters the type 1 Cu site. The HPLC-MS analyses of the ABTS adduct trypsin digests revealed a distinct tyrosine within a unique loop as site involved in the modification of the blue laccase form. Thus, S. sclerotiorum yellow laccase seems to be an intrinsically blue multi-copper oxidase that boosts its activity and stability with a radical-forming aromatic substrate. This particular case could, at least in part, explain the enigma of the yellow laccases.
Up till 20 years ago, in order to endow molecules with function there were two mainstream lines of thought. One was to rationally design the positioning of chemical functionalities within candidate ...molecules, followed by an iterative synthesis–optimization process. The second was the use of a “brutal force” approach of combinatorial chemistry coupled with advanced screening for function. Although both methods provided important results, “rational design” often resulted in time‐consuming efforts of modeling and synthesis only to find that the candidate molecule was not performing the designed job. “Combinatorial chemistry” suffered from a fundamental limitation related to the focusing of the libraries employed, often using lead compounds that limit its scope. Dynamic constitutional chemistry has developed as a combination of the two approaches above. Through the rational use of reversible chemical bonds together with a large plethora of precursor libraries, one is now able to build functional structures, ranging from quite simple molecules up to large polymeric structures. Thus, by introduction of the dynamic component within the molecular recognition processes, a new perspective of deciphering the world of the molecular events has aroused together with a new field of chemistry. Since its birth dynamic constitutional chemistry has continuously gained attention, in particular due to its ability to easily create from scratch outstanding molecular structures as well as the addition of adaptive features. The fundamental concepts defining the dynamic constitutional chemistry have been continuously extended to currently place it at the intersection between the supramolecular chemistry and newly defined adaptive chemistry, a pivotal feature towards evolutive chemistry.
Până în urmă cu 20 de ani existau două direcţii de cercetare pentru obţinerea de molecule utilizabile în diverse aplicaţii. O direcţie era reprezentată de design‐ul raţional al grupărilor funcţionale în structura moleculelor candidate, urmată de un proces iterativ de optimizări sintetice. Cea de a doua direcţie a constat în abordarea “forţei brute” a chimiei combinatorii cuplată cu screening‐ul pentru diferite aplicaţii. Deşi ambele metode au condus la obţinerea de rezultate importante, “design‐ul raţional” s‐a dovedit deseori costisitor din punctul de vedere al timpului necesar pentru modelarea şi sinteza unor molecule, care apoi se dovedeau ineficiente pentru scopul dorit. În acelaşi timp, “chimia combinatorie” are un neajuns semnificativ cauzat de diversitatea componentelor bibliotecilor utilizate, deseori compuşii selecţionaţi limitându‐i scopul. Chimia constituţional dinamică s‐a dezvoltat ca o combinaţie a celor două abordări descrise mai sus. Utilizarea raţională a legăturilor covalente reversibile, împreună cu o gamă variată de precursori ai bibliotecilor, a condus la obţinerea unor structuri funcţionale, de la molecule simple până la compuşi polimerici. Astfel, introducerea componentei dinamice în procesul de recunoaştere moleculară a avut ca rezultat o nouă viziune privind studiul evenimentelor moleculare şi a dus la apariţia unui nou domeniu al chimiei. Dezvoltarea spectaculoasă a chimiei constituţional dinamice s‐a datorat în special capacităţii de a crea structuri remarcabile din compuşi simpli, dar şi caracterului său adaptativ. Conceptele fundamentale care definesc chimia constituţional dinamică s‐au extins continuu, plasând‐o în momentul de faţă la interfaţa dintre chimia supramoleculară şi mai tânăra definită chimie adaptativă, o caracteristică fundamentală a chimiei evolutive.
Located at the intersection between supramolecular chemistry and adaptive chemistry, dynamic constitutional chemistry has evolved as one of the most powerful tools for the generation of remarkable structural architectures otherwise very difficult or often impossible to prepare. A literature survey describing the dynamic chemistry of artificial receptors for neutral or positively charged organic small‐molecules is presented (see scheme).
Gliding-arc discharges have been utilized in plasma-assisted combustion processes, among various other applications, due to their properties of high electron density and chemical selectivity in a ...transitional regime. However, basic characteristics relative to the relations between the fundamental parameters of discharge, like mass flow rate, breakdown voltage, and frequency of repetition (number of discharge breakdowns per half cycle), have not been completely studied. In this paper, an ac-powered gliding-arc discharge having a reverse vortex flow configuration is built to carry on a basic investigation on discharges in air, natural gas, and mixture of both. Electrical measurements, optical emission spectroscopy, and mass spectrometry are the techniques used for these investigations. The results presented in this paper describe the dependence of the breakdown voltage, frequency of discharges, and conversion rates of methane and molecular oxygen with respect to the variation of the mass flow rate (directly related to the residence time) and discharge current.
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