Patient Satisfaction and Ultrasound Use During Pregnancy

Use, number, and frequency of ultrasounds women receive during pregnancy vary widely in practice. Current evidence suggests that women presenting with pregnancy complications benefit from additional ultrasounds, although excessive ultrasound use in low risk pregnancies may be unnecessary, costly and potentially harmful. However, evidence also finds that the use of ultrasound technology is associated with mothers’ feelings of security and satisfaction with care; health care organizations are incentivized to promote these feelings of patient satisfaction, especially when clinical risk is considered low. Here, we examine the impact of ultrasound use on satisfaction during pregnancy among women in the Northeast who have recently given birth through an online retrospective survey. Contrary to expectations, findings suggest that ultrasound use is not a significant driver of satisfaction with pregnancyrelated care. Efforts to enhance patient satisfaction during pregnancy using ultrasounds may increase resource use and cost, but do little to enhance patient experience overal

Measurement of shoulder joint strength and mobility in common collegiate aged overhead athletes

Introduction: Previous research has stereotyped many overhead athletes as baseball pitchers. Due to the different physiological stresses in each overhead sport, it may not be appropriate to group all overhead athletes together. The objective of this study was to show sport specific physical adaptations in common overhead sports. Methods: Forty-three healthy, male athletes participated in this cross-sectional study; fifteen baseball pitchers, fifteen volleyball athletes, thirteen tennis athletes and fifteen control athletes. Internal rotation (IR) and external rotation (ER) shoulder range of motion (ROM), glenohumeral internal rotation deficit (GIRD), external rotation gain (ERG), posterior shoulder tightness (PST) (supine and side-lying methods), shoulder strength and scapular kinematics were assessed in a neuromuscular research laboratory. ROM was assessed with a goniometer while PST was assessed with a goniometer (supine) and carpenters' square (side-lying). Strength was assessed with an isokinetic dynamometer and scapular kinematics with an electromagnetic tracking device. Results: Pitchers had more dominant IR ROM than tennis athletes and less dominant IR ROM than control athletes. Tennis athletes had the lowest IR ROM of all groups included in this study. Volleyball athletes had less dominant IR ROM than control athletes. Pitchers and tennis athletes had more GIRD than control athletes had. Pitchers and tennis athletes had higher between limb differences with the supine method of assessing PST. With the supine assessment, tennis athletes had increased dominant PST compared to control athletes; additionally, all overhead athletes had decreased non-dominant PST. At 90° and 120° humeral elevation, pitchers had the most scapular elevation, volleyball athletes had more elevation than tennis athletes did, and tennis athletes had less elevation than control athletes did. There were no differences in external rotation ROM, total rotation ROM, or strength measures. Conclusion: Not all overhead athletes had the same physical characteristics. The differences between sports in each of the variables could be due to the different amount of physiologic stress on the shoulder in each sport. These results may help to show healthy, sport specific adaptations in each sport. Clinicians should develop sport specific rehabilitation protocols and return to play criteria for athletes to return to play earlier and stronger

How To Build a Better Testbed: Lessons From a Decade of Network Experiments on Emulab

International audienceThe Emulab network testbed provides an environment in which researchers and educators can evaluate networked systems. Available to the public since 2000, Emulab is used by thousands of experimenters at hundreds of institutions around the world, and the research conducted on it has lead to hundreds of publications. The original Emulab facility at the University of Utah has been replicated at dozens of other sites. The physical design of the Emulab facility, and many other testbeds like it, has been based on the facility operators' expectations regarding user needs and behavior. If operators' assumptions are incorrect, the resulting facility can exhibit inefficient use patterns and sub-optimal resource allocation. Our study, the first of its kind, gains insight into the needs and behaviors of networking researchers by analyzing more than 500,000 topologies from 13,000 experiments submitted to Emulab. Using this dataset, we re-visit the assumptions that went into the physical design of the Emulab facility and consider improvements to it. Through extensive simulations with real workloads, we evaluate alternative testbeds designs for their ability to improve testbed utilization and reduce hardware costs

Leveraging bloom filters for smart search within NUCA caches

Journal ArticleOn-chip wire delays are becoming increasingly problematic in modern microprocessors. To alleviate the negative effect of wire delays, architects have considered splitting up large L2/L3 caches into several banks, with each bank having a different access latency depending on its physical proximity to the core. In particular, several recent papers have considered dynamic non-uniform cache architectures (D-NUCA) for chip multi-processors. These caches are dynamic in the sense that cache lines may migrate towards the cores that access them most frequently. In order to realize the benefits of data migration, however, a "smart search" mechanism for finding the location of a given cache line is necessary. These papers assume an oracle and leave the smart search for future work. Existing search mechanisms either entail high performance overheads or inordinate storage overheads. In this paper, we propose a smart search mechanism, based on Bloom filters. Our approach is complexity-effective: it has the potential to reduce the performance and storage overheads of D-NUCA implementations. Also, Bloom filters are simple structures that incur little design complexity. We present the results of our initial explorations, showing the promise of our novel search mechanism

TagFS: organizing information using Tags

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Doctor of Philosophy

dissertationNetwork emulation has become an indispensable tool for the conduct of research in networking and distributed systems. It offers more realism than simulation and more control and repeatability than experimentation on a live network. However, emulation testbeds face a number of challenges, most prominently realism and scale. Because emulation allows the creation of arbitrary networks exhibiting a wide range of conditions, there is no guarantee that emulated topologies reflect real networks; the burden of selecting parameters to create a realistic environment is on the experimenter. While there are a number of techniques for measuring the end-to-end properties of real networks, directly importing such properties into an emulation has been a challenge. Similarly, while there exist numerous models for creating realistic network topologies, the lack of addresses on these generated topologies has been a barrier to using them in emulators. Once an experimenter obtains a suitable topology, that topology must be mapped onto the physical resources of the testbed so that it can be instantiated. A number of restrictions make this an interesting problem: testbeds typically have heterogeneous hardware, scarce resources which must be conserved, and bottlenecks that must not be overused. User requests for particular types of nodes or links must also be met. In light of these constraints, the network testbed mapping problem is NP-hard. Though the complexity of the problem increases rapidly with the size of the experimenter's topology and the size of the physical network, the runtime of the mapper must not; long mapping times can hinder the usability of the testbed. This dissertation makes three contributions towards improving realism and scale in emulation testbeds. First, it meets the need for realistic network conditions by creating Flexlab, a hybrid environment that couples an emulation testbed with a live-network testbed, inheriting strengths from each. Second, it attends to the need for realistic topologies by presenting a set of algorithms for automatically annotating generated topologies with realistic IP addresses. Third, it presents a mapper, assign, that is capable of assigning experimenters' requested topologies to testbeds' physical resources in a manner that scales well enough to handle large environments

A survey of computing migration

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Potential Upgrade of the CMS Tracker Analog Readout Optical Links Using Bandwidth Efficient Digital Modulation

The potential application of advanced digital communication schemes in a future upgrade of the CMS Tracker readout optical links is currently being investigated at CERN. We show experimentally that multi-Gbit/s data rates are possible over the current 40 MSamples/s analog optical links by employing techniques similar to those used in ADSL. The concept involves using one or more digitally-modulated sinusoidal carriers in order to make efficient use of the available bandwidth.Comment: Presented at LECC 2006, Valencia, Spain. 5 pages, 11 figures

Feasibility of Using Bandwidth Efficient Modulation to Upgrade the CMS Tracker Readout Optical Links

Plans to upgrade the LHC after approximately 10 years of operation are currently being considered at CERN. A tenfold increase in luminosity delivered to the experiments is envisaged in the so-called Super LHC (SLHC). This will undoubtedly give rise to significantly larger data volumes from the detectors, requiring faster data readout. The possibility of upgrading the CMS Tracker analog readout optical links using a bandwidth efficient digital modulation scheme for deployment in the SLHC has been extensively explored at CERN. Previous theoretical and experimental studies determined the achievable data rate using a system based on Quadrature Amplitude Modulation (QAM) to be ~3-4Gbit/s (assuming no error correction is used and for an error rate of ~10-9). In this note we attempt to quantify the feasibility of such an upgrade in terms of hardware implementation complexity, applicability to the high energy physics (HEP) environment, technological feasibility and R&D effort required.Comment: CERN CMS Note. 16 pages, 10 figure