Characterizing convection schemes using their responses to imposed tendency perturbations

Convection is usually parameterized in global climate models, and there are often large discrepancies between results obtained with different convection schemes. Conventional methods of comparing convection schemes using observational cases or directly in 3D models do not always clearly identify parameterization strengths and weaknesses. In this paper we evaluate the response of parameterizations to various perturbations rather than their behavior under particular strong forcing. We use the linear response function method proposed by Kuang (2010) to compare twelve physical packages in five atmospheric models using single-column model (SCM) simulations under idealized radiative-convective equilibrium conditions. The models are forced with anomalous temperature and moisture tendencies. The temperature and moisture departures from equilibrium are compared with published results from a cloud-resolving model (CRM). Results show that the procedure is capable of isolating the behavior of a convection scheme from other physics schemes. We identify areas of agreement but also substantial differences between convection schemes, some of which can be related to scheme design. Some aspects of the model linear responses are related to their RCE profiles (the relative humidity profile in particular), while others constitute independent diagnostics. All the SCMs show irregularities or discontinuities in behavior that are likely related to switches or thresholds built into the convection schemes, and which do not appear in the CRM. Our results highlight potential flaws in convection schemes and suggest possible new directions to explore for parameterization evaluation

Impaired Mineral Ion Metabolism in a Mouse Model of Targeted Calcium-Sensing Receptor (CaSR) Deletion from Vascular Smooth Muscle Cells

Background Impaired mineral ion metabolism is a hallmark of CKD–metabolic bone disorder. It can lead to pathologic vascular calcification and is associated with an increased risk of cardiovascular mortality. Loss of calcium-sensing receptor (CaSR) expression in vascular smooth muscle cells exacerbates vascular calcification in vitro. Conversely, vascular calcification can be reduced by calcimimetics, which function as allosteric activators of CaSR. Methods To determine the role of the CaSR in vascular calcification, we characterized mice with targeted Casr gene knockout in vascular smooth muscle cells (SM22αCaSRΔflox/Δflox). Results Vascular smooth muscle cells cultured from the knockout (KO) mice calcified more readily than those from control (wild-type) mice in vitro. However, mice did not show ectopic calcifications in vivo but they did display a profound mineral ion imbalance. Specifically, KO mice exhibited hypercalcemia, hypercalciuria, hyperphosphaturia, and osteopenia, with elevated circulating fibroblast growth factor 23 (FGF23), calcitriol (1,25-D3), and parathyroid hormone levels. Renal tubular α-Klotho protein expression was increased in KO mice but vascular α-Klotho protein expression was not. Altered CaSR expression in the kidney or the parathyroid glands could not account for the observed phenotype of the KO mice. Conclusions These results suggest that, in addition to CaSR’s established role in the parathyroid-kidney-bone axis, expression of CaSR in vascular smooth muscle cells directly contributes to total body mineral ion homeostasis

A parallel control architecture for industrial robot cells

We present a parallel control architecture for industrial robot cells. It is based on closed functional components arranged in a flat communication hierarchy. The components may be executed by different processing elements, and each component itself may run on multiple processing elements. The system is driven by the instructions of a central cell control component. We set up necessary requirements for industrial robot cells and possible parallelization levels. These are met by the suggested robot control architecture. As an example we present a robot work cell and a component for motion planning, which fits well in this concept

Characterizing Convection Schemes Using Their Responses to Imposed Tendency Perturbations

Convection is usually parameterized in global climate models, and there are often large discrepancies between results obtained with different convection schemes. Conventional methods of comparing convection schemes using observational cases or directly in three-dimensional (3D) models do not always clearly identify parameterization strengths and weaknesses. In this paper we evaluate the response of parameterizations to various perturbations rather than their behavior under particular strong forcing. We use the linear response function method proposed by Kuang (2010) to compare 12 physical packages in five atmospheric models using single-column model (SCM) simulations under idealized radiative-convective equilibrium conditions. The models are forced with anomalous temperature and moisture tendencies. The temperature and moisture departures from equilibrium are compared with published results from a cloud-resolving model (CRM). Results show that the procedure is capable of isolating the behavior of a convection scheme from other physics schemes. We identify areas of agreement but also substantial differences between convection schemes, some of which can be related to scheme design. Some aspects of the model linear responses are related to their RCE profiles (the relative humidity profile in particular), while others constitute independent diagnostics. All the SCMs show irregularities or discontinuities in behavior that are likely related to threshold-related mechanisms used in the convection schemes, and which do not appear in the CRM. Our results highlight potential flaws in convection schemes and suggest possible new directions to explore for parameterization evaluation

Operational experience with the CMS Data Acquisition System

The data-acquisition (DAQ) system of the CMS experiment at the LHC performs the read-out and assembly of events accepted by the first level hardware trigger. Assembled events are made available to the high-level trigger (HLT), which selects interesting events for offline storage and analysis. The system is designed to handle a maximum input rate of 100 kHz and an aggregated throughput of 100 GB/s originating from approximately 500 sources and $10^8$ electronic channels. An overview of the architecture and design of the hardware and software of the DAQ system is given. We report on the performance and operational experience of the DAQ and its Run Control System in the first two years of collider runs of the LHC, both in proton-proton and Pb-Pb collisions. We present an analysis of the current performance, its limitations, and the most common failure modes and discuss the ongoing evolution of the HLT capability needed to match the luminosity ramp-up of the LHC