Light bottom squark and gluino confront electroweak precision measurements

We address the compatibility of a light sbottom (mass 2\sim 5.5 \gev) and a light gluino (mass 12\sim 16 \gev) with electroweak precision measurements. Such light particles have been suggested to explain the observed excess in the $b$ quark production cross section at the Tevatron. The electroweak observables may be affected by the sbottom and gluino through the SUSY-QCD corrections to the $Zbb$ vertex. We examine, in addition to the SUSY-QCD corrections, the electroweak corrections to the gauge boson propagators from the stop which are allowed to be light from the SU(2)$_L$ symmetry. We find that this scenario is strongly disfavored from electroweak precision measurements unless the heavier sbottom mass eigenstate is lighter than 180\gev and the left-right mixing in the stop sector is sufficiently large. This implies that one of the stops should be lighter than about 98\gev.Comment: 4 pages, revtex, 2 figures. Reference added, version to appear in Phys.Rev.Let

Helmholtz resonance in a piezoelectric–hydraulic pump-based hybrid actuator

This paper demonstrates that a hydraulically acting Helmholtz resonator can exist in a piezoelectric–hydraulic pump (PHP) based hybrid actuator, which in turn affects the volumetric efficiency of the PHP. The simulation and experimental results illustrate the effect of Helmholtz resonance on the flow rate performance of the PHP. The study also shows how to shift the Helmholtz resonant frequency to a higher value through changing parameters such as the cylinder diameter and the effective bulk modulus of the working fluid, which will improve the volumetric efficiency and broaden the operating frequency range of the PHP actuator.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90809/1/0964-1726_20_1_015010.pd

Switching sliding mode force tracking control of piezoelectric-hydraulic pump-based friction element actuation systems for automotive transmissions

In this study, a nonlinear sliding-mode controller is designed for force tracking of a piezoelectric-hydraulic pump (PHP)-based actuation system, which is developed to replace the current electro-hydraulic actuation systems for automatic transmission (AT) friction elements, such as band brakes or clutches. By utilizing the PHP, one can eliminate the various hydraulic components (oil pump, regulating valve and control valve) in current ATs and achieve a simpler configuration with more efficient operation. With the derived governing equation of motion of the PHP-based actuation system integrated with the friction element (band brake), a switching control law is synthesized based on the sliding-mode theory. To evaluate the effectiveness of the proposed control law, its force tracking performance for the engagement of a friction element during an AT ##IMG## [http://ej.iop.org/images/0964-1726/18/8/085004/sms306895ieqn1.gif] {1 to 2} up-shift is examined experimentally. It is shown that one can successfully track the desired force trajectory for AT shift control with small tracking error. This study demonstrates the potential of the PHP as a new controllable actuation system for AT friction elements.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65109/2/sms9_8_085004.pd

Younger but sicker? : Cohort trends in disease accumulation among middle-aged and older adults in Scotland using health-linked data from the Scottish Longitudinal Study

This research was supported by the Economic and Social Research Council (ESRC) Centre for Population Change Connecting Generations research programme, grant number ES/W002116/1. This work was supported by the Academy of Medical Sciences, the Wellcome Trust, the Government Department of Business, Energy and Industrial Strategy, the British Heart Foundation Diabetes UK, and the Global Challenges Research Fund [Grant number SBF004\1093 awarded to Katherine Keenan]. The contribution from AM is funded by the National Institute for Health and Care Research (grant number NIHR202639).Background In the United Kingdom, rising prevalence of multimorbidity—the co-occurrence of two or more chronic conditions- is coinciding with stagnation in life expectancy. We investigate patterns of disease accumulation and how they vary by birth cohort, social and environmental inequalities in Scotland, a country which has long suffered from excess mortality and poorer health outcomes relative to its neighbours. Methods Using a dataset which links census data from 1991, 2001 and 2011 to disease registers and hospitalization data, we follow cohorts of adults aged 30–69 years for 18 years. We model physical and mental disease accumulation using linear mixed-effects models. Results Recent cohorts experience higher levels of chronic disease accumulation compared to their predecessors at the same ages. Moreover, in more recently born cohorts we observe socioeconomic status disparities emerging earlier in the life course, which widen over time and with every successive cohort. Patterns of chronic conditions are also changing, and the most common diseases suffered by later born cohorts are cancer, hypertension, asthma, drug and alcohol problems and depression. Conclusion We recommend policies which target prevention of chronic disease in working age adults, considering how and why certain conditions are becoming more prevalent across time and space.Peer reviewe

CT‑guided percutaneous transthoracic lung biopsy: First experience in Ibadan, Nigeria

Percutaneous lung biopsy had been described in the nineteenth century by Leyden, but image- guided needle chest biopsy only gained widespread acceptance in the 1970s. Currently, tissue sampling of a thoracic lesion is indicated when the diagnosis cannot be obtained by the non-invasive techniques and cytological diagnosis will modify the stage of the disease or influence the therapeutic strategy. Cytology obtained by small-gauge needle aspiration biopsy confirms the nature of the lesion in 80 – 95% of cases and carry a low incidence of major complications. The purpose of this report was to provide information on our first experience with CT-guided biopsy and show that with some innovativeness much can be achieve with limited resources and good team work. We performed a CT of the thorax using appropriately placed improvised metal markers, which determined the optimal cutaneous entry point. We then re-checked the location of the lesion scanning intermittently at 5mm slice thickness; we marked the entry point with a pen and cleaned the surface with methylated spirit. A local anaesthetic was subcutaneously injected around marked area. We used a 21G aspiration needle to obtain cytology sample then 18G Trucut biopsy needle to obtain histology specimen. The length of the needle was chosen based on predetermined distance of the target lesion from the skin estimated from the CT images. Our patient was a 51-year-old Nigerian female with a peripherally located nodule in the posterior aspect of the right lung. She had CT-guided biopsy of the nodule. The procedure was well tolerated with no complication of pneumothorax. The histology report provided the basis for treatment regimen. Our experience indicates that percutaneous transthoracic CT-guided needle biopsy is feasible and a safe procedure in our hospital for evaluation of undetermined lung lesions.Keywords: CT‑guided biopsy, pneumothorax, pulmonary noduleNigerian Journal of Clinical Practice • Oct-Dec 2013 • Vol 16 • Issue

Co-simulation setup for online model-assisted control design

For reduction of energy intensity of the building sector, effective and parsimonious use of energy resources and climate control systems is a prerequisite. Intelligent Building Energy Management Systems (BEMS) can be key ingredients towards achieving this goal; the incorporation of forecast data into the decision process can help achieve improved performance compared to existing state-of-the-art approaches. In the present paper, the potential of model-based supervisory control design algorithms for automatically designing BEMS is evaluated by performing experiments in a real building. A co-simulation setup is implemented where the thermal simulation model of the building is warmed up using past sensed data and then, given weather and occupancy forecasts, a controller is designed by solving a constrained minimization problem. A stochastic optimization algorithm is used to intelligently search the controller parameter space and identify a controller that minimizes an energy-related cost function, subject to thermal comfort constraints. A middleware solution is deployed in the building to facilitate two-way communication between the building (sensing and actuation) layer and the algorithmic layer

Religious norms, norm conflict, and religious identification

The present research sought to understand how religious identification is associated with normative practices and with norm conflict (the perception that people within the religious group are not all enacting the same standards or rules for behaviour). Using a multi-faith sample (N=400) we replicate positive associations of religious identification with engaging in normative practices such as prayer, and the associations of both identification and normative practices with stronger well-being. Religious norm conflict was associated with lower identification and lower well-being, however. Three coping strategies were examined: 1) engaging in normative ritual practices was protective of identification and well-being; 2) affirming that the conflict occurs on less important (vs core) religious norms was associated with higher well-being, but not with identification; and 3) challenging the religious norm was associated with lower well-being, but did not alter religious identification

Cosmological gravitino problem confronts electroweak physics

A generic feature of gauge-mediated supersymmetry breaking models is that the gravitino is the lightest supersymmetric particle (LSP). In order not to overclose the universe, the gravitino LSP should be light enough (~ 1 keV), or appropriately heavy (~ 1 GeV). We study further constraints on the mass of the gravitino imposed by electroweak experiments, i.e., muon g-2 measurements, electroweak precision measurements, and direct searches for supersymmetric particles at LEP2. We find that the heavy gravitino is strongly disfavored from the lower mass bound on the next-to-LSP. The sufficiently light gravitino, on the other hand, has rather sizable allowed regions in the model parameter space.Comment: 11 pages, 8 figures, version to appear in PR