The Online Calibration, Operation, and Performance of the CMS Pixel Detector

The CMS pixel detector consists of approximately 66 million silicon pixels whose analog signals are read out by 15,840 programmable Readout Chips. With the recent startup of the LHC, the detector is now collecting data used for precise vertexing and track-finding. In preparation for data taking, the detector's Readout Chips and their supporting readout and control electronics were calibrated. The calibration that has taken place since the detector's installation in the summer of 2008 will be described. These calibrations focused on the optimization of the Readout Chips' thresholds and analog response. The operation of the detector during the early running of the LHC will also be discussed. The calibrations that are performed on a regular basis and a mechanism to handle the readout of large beam background events will be described.Comment: 6 pages, 6 figures; Proceeding of Pixel2010, International Workshop on Semiconductor Pixel Detectors for Particles and Imaging, Grindelwald Switzerland, September 6 - 10, 201

Actively Contracting Bundles of Polar Filaments

We introduce a phenomenological model to study the properties of bundles of polar filaments which interact via active elements. The stability of the homogeneous state, the attractors of the dynamics in the unstable regime and the tensile stress generated in the bundle are discussed. We find that the interaction of parallel filaments can induce unstable behavior and is responsible for active contraction and tension in the bundle. Interaction between antiparallel filaments leads to filament sorting. Our model could apply to simple contractile structures in cells such as stress fibers.Comment: 4 pages, 4 figures, RevTex, to appear in Phys. Rev. Let

Reducing Construction Costs Through Effective Field Communication and Administration

Falling Road Fund receipts have placed added strain on the Kentucky Transportation Cabinet’s (KYTC) already-underfunded highway program. Revenue declines have increased the urgency of improving the efficiency and cost-effectiveness of the Cabinet’s operations. One method KYTC can use to realize greater cost savings is improving the administration of construction projects. Effective field communication and administration helps control construction costs, enhances quality, and minimizes delays and claims. One challenge the Cabinet will need to confront to more effectively administer projects, however, is the loss of institutional knowledge associated with staff attrition. The report documents KYTC current methods for project staffing, communication, and partnering. It summarizes best practices for field communication and administration used throughout the private and public sector construction industries and discusses findings obtained through interviews with Cabinet staff and industry representatives on the issues in-house staff and external contractors routinely negotiate during projects. Based on analysis of these interviews and the literature reviewed, the report identifies five issues that are commonly encountered on KYTC construction projects and puts forward recommendations for ameliorating them. Additionally, it proposes a new initiative — Putting the Project First — which has as its goal the development of tools, practices, guidance, and training to meet stakeholder needs across all project types. Several recommendations, which can be enacted over the short-, intermediate-, and long-term are advanced to build a sound and practical foundation for all Putting the Project First activities. This initiative will strengthen relationships between the Cabinet and its contractors. It will also help build an institutional framework for conducting field communications and administration, one resilient in the face of staff turnover

Therapy of intracellular Staphylococcus aureus by tigecyclin

BACKGROUND: In the fields of traumatology and orthopaedics staphylococci are the most frequently isolated pathogens. Staphylococcus aureus and Staphylococcus epidermidis are known to be the major causative agents of osteomyelitis. The increasing number of multiresistant Staphylococcus aureus and resistant coagulase-negative staphylococci as a trigger of complicated osteomyelitis and implant-associated infections is a major problem. Antibiotic therapy fails in 20% of cases. Therefore the development of novel antibiotics becomes necessary. METHODS: This study analyses tigecyclin, the first antibiotic of the glycylines, as a potential therapy for osteomyelitis caused by multiresistant Staphylococcus aureus. Therefore its intracellular activity and the potential use in polymethylmetacrylate-bone cement are examined. The intracellular activity of tigecyclin is determined by a human osteoblast infection model. The investigation of the biomechanical characteristics is conducted concerning the ISO 5833-guidelines. RESULTS: Tigecyclin shows in vitro an intracellular activity that ranges between the antimicrobial activity of gentamicin and rifampicin. A significant negative effect on the biomechanical characteristics with an impaired stability is detected after adding tigecyclin to polymethylmetacrylate-bone cement with a percentage of 1.225% per weight. CONCLUSIONS: This study shows that tigecyclin might be a potent alternative for the systemic therapy of osteomyelitis and implant-associated infections whereas the local application has to be reconsidered individually

A Microscopic Mechanism for Muscle's Motion

The SIRM (Stochastic Inclined Rods Model) proposed by H. Matsuura and M. Nakano can explain the muscle's motion perfectly, but the intermolecular potential between myosin head and G-actin is too simple and only repulsive potential is considered. In this paper we study the SIRM with different complex potential and discuss the effect of the spring on the system. The calculation results show that the spring, the effective radius of the G-actin and the intermolecular potential play key roles in the motion. The sliding speed is about $4.7\times10^{-6}m/s$ calculated from the model which well agrees with the experimental data.Comment: 9 pages, 6 figure

Therapy of intracellular Staphylococcus aureus by tigecyclin

Background: In the fields of traumatology and orthopaedics staphylococci are the most frequently isolated pathogens. Staphylococcus aureus and Staphylococcus epidermidis are known to be the major causative agents of osteomyelitis. The increasing number of multiresistant Staphylococcus aureus and resistant coagulase-negative staphylococci as a trigger of complicated osteomyelitis and implant-associated infections is a major problem. Antibiotic therapy fails in 20% of cases. Therefore the development of novel antibiotics becomes necessary. Methods: This study analyses tigecyclin, the first antibiotic of the glycylines, as a potential therapy for osteomyelitis caused by multiresistant Staphylococcus aureus. Therefore its intracellular activity and the potential use in polymethylmetacrylate-bone cement are examined. The intracellular activity of tigecyclin is determined by a human osteoblast infection model. The investigation of the biomechanical characteristics is conducted concerning the ISO 5833-guidelines. Results: Tigecyclin shows in vitro an intracellular activity that ranges between the antimicrobial activity of gentamicin and rifampicin. A significant negative effect on the biomechanical characteristics with an impaired stability is detected after adding tigecyclin to polymethylmetacrylate-bone cement with a percentage of 1.225% per weight. Conclusions: This study shows that tigecyclin might be a potent alternative for the systemic therapy of osteomyelitis and implant-associated infections whereas the local application has to be reconsidered individually.<br

Surface characterization by structure function analysis

The structure function is a tool for characterizing technical surfaces which exhibits a number of advantages over Fourier-based analysis methods. So it is optimally suited for analyzing the height distributions of surfaces measured by full-field non-contacting methods. After the definition of line- and area-structure function and offering effective procedures for their calculation this tutorial paper presents examples using simulated and measured data of machined surfaces as well as optical components. Comparisons with the results of Fourier-based evaluations clearly prove the advantages of structure function analysis

Molecular Motor of Double-Walled Carbon Nanotube Driven by Temperature Variation

An elegant formula for coordinates of carbon atoms in a unit cell of a single-walled nanotube (SWNT) is presented and a new molecular motor of double-walled carbon nanotube whose inner tube is a long (8,4) SWNT and outer tube a short (14,8) SWNT is constructed. The interaction between inner an outer tubes is analytically derived by summing the Lennard-Jones potentials between atoms in inner and outer tubes. It is proved that the molecular motor in a thermal bath exhibits a directional motion with the temperature variation of the bath.Comment: 9 pages, 4 figures, revtex