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1.
Jason J. Chang Ansley Stanfill Tayebeh Pourmotabbed 《International journal of molecular sciences》2016,17(8)
Stroke remains the fifth leading cause of mortality in the United States with an annual rate of over 128,000 deaths per year. Differences in incidence, pathogenesis, and clinical outcome have long been noted when comparing ischemic stroke among different ethnicities. The observation that racial disparities exist in clinical outcomes after stroke has resulted in genetic studies focusing on specific polymorphisms. Some studies have focused on matrix metalloproteinases (MMPs). MMPs are a ubiquitous group of proteins with extensive roles that include extracellular matrix remodeling and blood-brain barrier disruption. MMPs play an important role in ischemic stroke pathophysiology and clinical outcome. This review will evaluate the evidence for associations between polymorphisms in MMP-1, 2, 3, 9, and 12 with ischemic stroke incidence, pathophysiology, and clinical outcome. The role of polymorphisms in MMP genes may influence the presentation of ischemic stroke and be influenced by racial and ethnic background. However, contradictory evidence for the role of MMP polymorphisms does exist in the literature, and further studies will be necessary to consolidate our understanding of these multi-faceted proteins. 相似文献
2.
DH Gustafson TN Robinson D Ansley L Adler PF Brennan 《Canadian Metallurgical Quarterly》1999,16(1):23-29
During the early phase following stroke, patients with aphasia and their families are totally involved in the rehabilitation programme, but later, in the chronic phase, after discharge, the family generally has no support and many problems may arise or become more acute and provoke disturbances in this system. The patients with aphasia and their spouses may feel the situation differently according to their own characteristics, including gender. The present study includes 55 spouses of patients with chronic aphasia and 37 controls (spouses of subjects without physical or cognitive impairments) who filled out a questionnaire concerning their respective spouses (European Brain Injury Questionnaire--EBIQ) and some aspects about themselves. It was concluded, from the opinions expressed by the spouses of patients with chronic aphasia that they have problems in several domains not only related to communication or physical impairments. The opinions of husbands and wives of patients with aphasia, but not of the controls, were different, with more references to behaviour changes in women with aphasia. Spouses' responses also show important changes in their own lives. These results stress the importance of adequate attention to the long-term psychosocial problems of patients and relatives. 相似文献
3.
Mesquite (Prosopis glandulosa) and redberry juniper (Juniperus pinchotii) are two woody species which dominate uncultivated lands in the south central Great Plains, USA (Texas, Oklahoma) and may have potential for bioenergy utilization. In this study, these two biomasses were gasified in an adiabatic, updraft fixed‐bed gasifier using air as medium. The products include low heating value gas and liquid tar yield. The effects of fuel moisture content and the equivalence ratio (ER) on liquid yields including heavy tar and light tar and higher heating value (HHV) of the producer gas were investigated. It was found that updraft gasifiers produce a large amount of tar, in a range of 100 g/Nm3 of gas produced. As the equivalence ratio (ER) increased (i.e. more rich char conditions), peak temperature (Tpeak) within the bed decreased due to the lesser partial oxidization. The liquid yield showed peak value with change in moisture content between 6 and 24%. Heavy tar is a very high quality fuel with a higher heating value of over 29 MJ/kg on a dry, ash‐free (DAF) basis which is a slightly higher than that of ethanol. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
4.
Piotr Szurgott Jerry Wekezer Leslaw Kwasniewski Jeffrey Siervogel Marc Ansley 《Canadian Metallurgical Quarterly》2011,16(1):108-116
Results from experimental testing of three permit vehicles are presented in the paper. The selected heavy vehicles, which require permits from state DOTs, included two tractor-trailer systems and a midsize crane. The vehicles were experimentally tested on popular existing speed bumps and on a representative highway bridge. The selected bridge was a reinforced-concrete structure constructed in 1999, located on the U.S. 90 in Northwest Florida. The bridge approach depression, combined with a distinct joint gap between the asphalt pavement and the concrete deck, triggered significant dynamic responses of the vehicle-bridge system. Similar dynamic vibrations were observed and recorded when the permit vehicles were driven over the speed bumps. Time histories of relative displacements, accelerations, and strains for selected locations on the vehicle-bridge system were recorded. The analysis of experimental data allowed for assessment of actual dynamic interactions between the vehicles and the speed bumps as well as dynamic load allowance factors for the selected bridge. 相似文献
5.
Abstract. A simplified version of the square root Kalman filter is obtained for a vector autoregressive moving-average (VARMA) model. The algorithm is computationally more efficient that the standard square root algorithm and its output can be used to compute the likelihood of a VARMA model accurately. 相似文献
6.
Eric V. Johnson Jr.Ronald A. Cook Forrest J. MastersMarcus H. Ansley 《Engineering Structures》2011,33(2):357-367
Performance of traffic signal support systems during hurricanes has indicated that the current dual cable system used in Florida often experiences substantial damage. Because there is widespread use of single cable support systems in hurricane-prone regions of other states, this project investigated the performance of both dual cable and single cable support systems in high velocity winds. The weight, orientation, and type of signal support hardware were modified to show the effects of various signal configurations. Test results indicate that (1) the difference in signal rotation is insignificant between dual cable and single cable systems, (2) the tension in the catenary cable does not significantly increase for either system; however, in the dual cable system, the increase in tensile force is substantial in the messenger cable resulting in increased flexural loading in the pole support structure, and (3) the cable supported traffic signals should be designed using both the drag and lift coefficients rather than just the drag coefficient to account for signal rotation. The single cable configuration was found to be the preferred option for structural response to wind. 相似文献
7.
Cynthia Nyquist-Battie Laura Freeman Kristen Leckband Stephanie Martinez Ariel Ansley Deanna Lund Daniel V. Lim 《Microgravity science and technology》2008,20(1):23-28
With the advent of prolonged spaceflights, it is important to determine if antibody-based assays can be used to monitor food
and water for bacterial contaminants. In the present work, a ground-based high aspect ratio vessel (HARV) was used to determine
if low shear modeled microgravity (LSMMG) alters antibody-binding to E. coli O157:H7 and Salmonella enterica serovar Typhimurium. Antibody–bacteria binding was similar under LSMMG and normal gravity because there was no difference
in amount of captured bacteria measured by colony forming units (CFU) between assays conducted in the HARV and a conventional
roller flask. The ability of E. coli O157:H7 and Salmonella Typhimurium grown in LSMMG to bind specific antibodies was also studied. After incubations of 4, 18 or 36 h in the HARV or
a shaking incubator, bacteria were harvested for enzyme-linked immunosorbent assays (ELISA). In the E. coli O157:H7 ELISA using a goat polyclonal primary antibody, LSMMG did not alter the linear range of detection (105–107 cells/ml) nor the signal to noise ratio at any bacterial concentration. Although insignificant changes in signal to noise
ratios were evident, LSMMG did not alter the range of detection (105–107 cells/ml) for Salmonella Typhimurium in ELISAs using either a polyclonal or a monoclonal antibody. These results suggest that immunoassays may be
used in spacecrafts because LSMMG does not have significant deleterious effects on antibody-binding to bacteria nor does it
significantly alter surface antigens necessary for antibody-based methods. 相似文献
8.
As wireless devices become more pervasive, mobile ad hoc networks are gaining importance, motivating the development of highly scalable ad hoc networking techniques. In this paper, we give an overview of the Safari architecture for highly scalable ad hoc network routing, and we present the design and evaluation of a specific realization of the Safari architecture, which we call Masai. We focus in this work on the scalability of learning and maintaining the routing state necessary for a large ad hoc network. The Safari architecture provides scalable ad hoc network routing, the seamless integration of infrastructure networks when and where they are available, and the support of self-organizing, decentralized network applications. Safari’s architecture is based on (1) a self-organizing network hierarchy that recursively groups participating nodes into an adaptive, locality-based hierarchy of cells; (2) a routing protocol that uses a hybrid of proactive and reactive routing information in the cells and scales to much larger numbers of nodes than previous ad hoc network routing protocols; and (3) a distributed hash table grounded in the network hierarchy, which supports decentralized network services on top of Safari. We evaluate the Masai realization of the Safari architecture through analysis and simulations, under varying network sizes, fraction of mobile nodes, and offered traffic loads. Compared to both the DSR and the L+ routing protocols, our results show that the Masai realization of the Safari architecture is significantly more scalable, with much higher packet delivery ratio and lower overhead. 相似文献
9.
Abstract. Ansley and Kohn ( Annals of Statistics , 1985) generalized the Kalman filter to handle state space models with partially diffuse initial conditions and used this filter to compute the marginal likelihood of the observations efficiently. In this paper we simplify the algorithm and make it numerically more accurate and operationally more efficient. Based on this filtering algorithm we obtain a corresponding smoothing algorithm for the state vector. 相似文献
10.