190 research outputs found
Bilateral and unilateral arm training improve motor function through differing neuroplastic mechanisms: a single-blinded randomized controlled trial
No full textBACKGROUND AND PURPOSE:
This randomized controlled trial tests the efficacy of bilateral arm training with rhythmic auditory cueing (BATRAC) versus dose-matched therapeutic exercises (DMTEs) on upper-extremity (UE) function in stroke survivors and uses functional magnetic resonance imaging (fMRI) to examine effects on cortical reorganization.
METHODS:
A total of 111 adults with chronic UE paresis were randomized to 6 weeks (3×/week) of BATRAC or DMTE. Primary end points of UE assessments of Fugl-Meyer UE Test (FM) and modified Wolf Motor Function Test Time (WT) were performed 6 weeks prior to and at baseline, after training, and 4 months later. Pretraining and posttraining, fMRI for UE movement was evaluated in 17 BATRAC and 21 DMTE participants.
RESULTS:
The improvements in UE function (BATRAC: FM Δ = 1.1 + 0.5, P = .03; WT Δ = -2.6 + 0.8, P < .00; DMTE: FM Δ = 1.9 + 0.4, P < .00; WT Δ = -1.6 + 0.7; P = .04) were comparable between groups and retained after 4 months. Satisfaction was higher after BATRAC than DMTE (P = .003). BATRAC led to significantly higher increase in activation in ipsilesional precentral, anterior cingulate and postcentral gyri, and supplementary motor area and contralesional superior frontal gyrus (P < .05). Activation change in the latter was correlated with improvement in the WMFT (P = .01).
CONCLUSIONS:
BATRAC is not superior to DMTE, but both rehabilitation programs durably improve motor function for individuals with chronic UE hemiparesis and with varied deficit severity. Adaptations in brain activation are greater after BATRAC than DMTE, suggesting that given similar benefits to motor function, these therapies operate through different mechanisms
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Annotated research bibliography for geothermal reservoir engineering
No full textThis bibliography is divided into the following subject areas: formation evaluation, modeling, exploitation strategies, and interpretation of production trends. A subject/author index is included. (MHR
A methodology for the optimization of PCD compact core drilling in basalt rock
No full textThis work presents an optimization technique using genetic algorithm for efficient core drilling in basalt rock. Optimization of the compact core-drilling problem is based on maximizing a desirability function which accounts for (a) maximizing the drilling feed while minimizing tool-wear progression, (b) minimizing the thrust force and torque (power), and (c) satisfying realistic constraints related to process parameters. The resulting set of optimized cutting parameters is sought in order to make the tool last longer while effectively drilling with high productivity. A room temperature model to relate the experimental data on changing drill forces and torques required by the progressive tool wear, and developed in a previous paper, is used in this study. © 2011 Springer-Verlag London Limited.Ali-Tavoli M, 2006, MACH SCI TECHNOL, V10, P491, DOI 10.1080-10910340600996126; Bourgoyne Jr A.T., 1974, T AIME SOC PET ENG J, V257, P371; Choudhury SK, 2000, INT J MACH TOOL MANU, V40, P899, DOI 10.1016-S0890-6955(99)00088-7; Clayton R, 2005, SPE IADC DRILL C P A; Fergason RL, 2006, J GEOPHYS RES-PLANET, V111, DOI 10.1029-2005JE002583; Fernandes M, 2006, INT J MACH TOOL MANU, V46, P76, DOI 10.1016-j.ijmachtools.2005.03.016; GLOWKA DA, 1989, J PETROL TECHNOL, V41, P850; GLOWKA DA, 1989, J PETROL TECHNOL, V41, P797; Hamade R. F., 2009, P ASME INT MECH ENG; Hamade RF, 2008, CIRP ICME 08 NAPL IT; Hamade RF, 2010, J MATER PROCESS TECH, V210, P1326, DOI 10.1016-j.jmatprotec.2010.03.023; Hamade RF, 2006, INT J MACH TOOL MANU, V46, P387, DOI 10.1016-j.ijmachtools.2005.05.016; Holland John Henry, 1992, ADAPTATION NATURAL A; Judzis A, 2009, SPE DRILL COMPLETION, V24, P25; Lia ZC, 2005, INT J MACH TOOL MANU, V45, P1402; MALAKOOTI B, 1989, OPER RES, V37, P805, DOI 10.1287-opre.37.5.805; Myers RH, 1995, PROBABILITY STAT SER; Plinninger RJ, 2004, EUROCK 2004 53 GEOM; Plinninger RJ, 2002, 9 P C INT ASS ENG GE, P2226; Sardinas RQ, 2006, ENG APPL ARTIF INTEL, V19, P127, DOI 10.1016-j.engappai.2005.06.007; Tulu IB, 2008, 42 US ROCK MECH 2 US; VENET V, 1993, REV I FR PETROL, V48, P15; Wang X, 2005, INT J PROD RES, V43, P3543, DOI 10.1080-13629390500124465; Weaver GE, 2000, US Patent, Patent No. 6109368; WOJTANOWICZ AK, 1993, J ENERG RESOUR-ASME, V115, P247, DOI 10.1115-1.2906429; Yinghui Liu, 2007, Journal of Manufacturing Science and Engineering, V129, DOI 10.1115-1.2515345; Zacny KA, 2004, J GEOPHYS RES-PLANET, V109, DOI 10.1029-2003JE002204; Zhang JY, 2006, J INTELL MANUF, V17, P203, DOI 10.1007-s10845-005-6637-z11
PGE2 reduces net water and chloride absorption from the rat colon by targeting the Na+-H+ exchanger and the Na+K+2Cl- cotransporter
No full textAn effect of PGE2 on water and chloride absorption was already established in a previous work. This study is an attempt to find the mechanism of action of the prostaglandin by investigating the involvement of three major transporters namely the Na+-K+ATPase, the Na+-H+ exchanger and the Na+K+2Cl- cotransporter. Rats were injected with PGE2 and 15 min later, the colon was perfused in situ with Krebs Ringer buffer, and net water and chloride absorption were determined. When the involvement of the cotransporter and-or the exchanger was investigated, animals were injected with, respectively, furosemide and amiloride 10 min before PGE2. Superficial and crypt colonocytes were then isolated and the protein expression of the Na+-K+ ATPase and the Na+K+2Cl- was determined by western blot analysis. The effect of PGE2 on the pump activity in presence or absence of the transporters' inhibitors was also studied. PGE2 decreased net water and chloride absorption from the colon, increased the Na+-K+ ATPase activity in superficial cells and reduced it in crypt cells. The prostaglandin was found to stimulate secretion in superficial cells by targeting the Na+K+2Cl- symporter, and reduce absorption in crypt cells by targeting the Na+-H+ antiporter. Changes in the activity of the pump are secondary to changes in the activity of the other transporters. © 2007 Elsevier Ltd. All rights reserved.Abramovitz M, 2000, BBA-MOL CELL BIOL L, V1483, P285, DOI 10.1016-S1388-1981(99)00164-X; ANDERSON RJ, 1976, KIDNEY INT, V10, P205, DOI 10.1038-ki.1976.99; Bachmann O, 2004, AM J PHYSIOL-GASTR L, V287, pG125, DOI 10.1152-ajpgi.00332.2003; Benos DJ, 1982, AM J PHYSIOL, V242, P131; BERTRAND B, 1994, J BIOL CHEM, V269, P13703; BINDER HJ, 1973, AM J PHYSIOL, V225, P1232; Bos CL, 2004, INT J BIOCHEM CELL B, V36, P1187, DOI 10.1016-j.biocel.2003.08.006; CHU J, 2002, AM J PHYSIOL-CELL PH, V283, P358; CORDINA J, 1999, J BIOL CHEM, V274, P19693; CROOK RB, 1992, J CELL PHYSIOL, V153, P214, DOI 10.1002-jcp.1041530126; CURRAN PF, 1960, J GEN PHYSIOL, V43, P555, DOI 10.1085-jgp.43.3.555; DAWSON DC, 1991, ANNU REV PHYSIOL, V53, P321; DELCASTILLO JR, 1991, AM J PHYSIOL, V261, pG1005; DONG J, 1994, AM J PHYSIOL-CELL PH, V267, pC1553; FLIEGEL L, 1993, BIOCHEM J, V296, P273; Gawenis LR, 2004, AM J PHYSIOL-GASTR L, V287, pG1140, DOI 10.1152-ajpgi.00177.2004; Geibel JP, 2001, GASTROENTEROLOGY, V120, P144, DOI 10.1053-gast.2001.20890; Greger R, 1997, NEWS PHYSIOL SCI, V12, P62; HARGIS L, 1988, ANAL CHEM PRINCIPLES, P314; HEBERT RL, 1990, AM J PHYSIOL, V259, P318; HEBERT RL, 1993, AM J PHYSIOL, V265, pF643; Heitzmann D, 2000, PFLUG ARCH EUR J PHY, V439, P378, DOI 10.1007-s004240050953; Kaji DM, 1996, AM J PHYSIOL-CELL PH, V271, pC354; KOCKERLING A, 1993, AM J PHYSIOL, V264, pC1285; KOEFOEDJOHNSEN V, 1958, ACTA PHYSIOL SCAND, V42, P298, DOI 10.1111-j.1748-1716.1958.tb01563.x; Kreydiyyeh SI, 2006, PROSTAG OTH LIPID M, V79, P43, DOI 10.1016-j.prostaglandins.2005.07.004; Kunzelmann K, 2002, PHYSIOL REV, V82, P245; LOMAX RB, 1994, AM J PHYSIOL, V266, pG71; Maly K, 2002, FEBS LETT, V521, P205, DOI 10.1016-S0014-5793(02)02867-3; MOOLENAAR WH, 1983, NATURE, V304, P645, DOI 10.1038-304645a0; Nielsen MS, 1998, PFLUG ARCH EUR J PHY, V435, P267; Rask-Madsen J, 1990, J Intern Med Suppl, V732, P137; SERNKA TJ, 1982, PROSTAGLANDINS, V23, P411, DOI 10.1016-0090-6980(82)90086-7; SIDOROV JJ, 1976, CLIN BIOCHEM, V9, P117, DOI 10.1016-S0009-9120(76)80032-X; SINGH SK, 1995, J CLIN INVEST, V96, P2373, DOI 10.1172-JCI118294; TAUSSKY HH, 1953, J BIOL CHEM, V202, P675; Thiagarajah JR, 2001, J PHYSIOL-LONDON, V536, P541, DOI 10.1111-j.1469-7793.2001.0541c.xd; TRAYNOR TR, 1993, J PHARMACOL EXP THER, V264, P61; Wakabayashi S, 1997, PHYSIOL REV, V77, P51; YUN CHC, 1995, AM J PHYSIOL-GASTR L, V269, pG122
Scalar soliton quantization with generic moduli
No full textThis article is distributed under the terms of the Creative Commons
Attribution License (CC-BY 4.0), which permits any use, distribution and reproduction in
any medium, provided the original author(s) and source are credArticle funded by SCOAP3. CP is
a Royal Society Research Fellow and partly supported by the U.S. Department of Energy
under grants DOE-SC0010008, DOE-ARRA-SC0003883 and DOE-DE-SC0007897. ABR
is supported by the Mitchell Family Foundation. We would like to thank the Mitchell
Institute at Texas A&M and the NHETC at Rutgers University respectively for hospitality
during the course of this work. We would also like to acknowledge the Aspen Center
for Physics and NSF grant 1066293 for a stimulating research environment which led to
questions addressed in this paper
Cathodic delamination of elastomer-to-metal adhesive joints: Experimental data and empirical modeling
No full textIn order to estimate the cathodic delamination rates of metal adhesive-steel adhesive bonds, an empirical model based on crack growth is developed. To this end, a considerable amount of delamination data was experimentally collected under several levels of cathodic environmental harshness (some highly accelerated) and applied peel stress. For a given electrolyte, cathodic delamination was found to depend on cathodic voltage (or current density), temperature, and applied strain energy release rate, G. In order to describe the progress of delamination under various cathodic environments as a function of applied G, the collected, experimental delamination-distance-versus-time data were used to develop characteristic curves of log delamination rates versus log G. For all conditions tested, these log-log plots were dominated by linear regions (commonly referred to as Region II) that follow the Paris law. In this region, it was found that bond delamination rates vary dramatically depending on the environment. Furthermore, and unlike with the critical fracture toughness (Gc), the threshold value of G (Gth) for the degraded bond varies from one set of cathodic conditions to another. To model delamination rates as function of the cathodic environment and G, a nonlinear equation capable of modeling subcritical crack growth behavior was used. The experimental delamination data was fitted to this equation in order to determine the coefficients of this equation. For each environment tested, one equation was determined and which describes the bond delamination rate versus G behavior over the entire G-range. Consequently, these coefficients were consolidated into master, easy-to-use, empirical equations that relate delamination rates to G. The resulting empirical model is applicable over a wide range of cathodic conditions of voltage and temperature. © 2006 Elsevier Ltd. All rights reserved.Curley AJ, 1998, J ADHESION, V66, P39, DOI 10.1080-00218469808009959; CURLEY AJ, 2000, INT J FRACTURE, V41, P103; CUTTS E, 1981, DEV ADHESIVES, P367; GUO S, 2003, THESIS VIRGINIA TECH; Hadavinia H, 2003, INT J ADHES ADHES, V23, P449, DOI 10.1016-S0143-7496(03)00074-5; Hamade RF, 2005, INT J ADHES ADHES, V25, P147, DOI 10.1016-j.ijadhadh.2004.06.002; Hamade R. F., 2004, SILANES OTHER COUPLI, V3, P69; Hamade RF, 2003, J ADHES SCI TECHNOL, V17, P1235, DOI 10.1163-156856103322114561; HAMMOND JS, 1981, CORROS SCI, V21, P239, DOI 10.1016-0010-938X(81)90033-0; HERTZBERG RW, 1976, DEFORMATION FRACTURE, P439; KOEHLER EL, 1984, CORROSION, V40, P5; LEFEBVRE DR, 1988, EXP MECH, V28, P38, DOI 10.1007-BF02328994; LEIDHEISER H, 1981, IND ENG CHEM PROD RD, V20, P547, DOI 10.1021-i300003a024; Leidheiser H. Jr., 1987, Journal of Adhesion Science and Technology, V1, DOI 10.1163-156856187X00094; LIECHTI KM, 1989, INT J FRACTURE, V39, P217, DOI 10.1007-BF00047451; LIECHTI KM, 1985, ADHESIVE SYSTEMS STR; Miller M. A., 1985, THESIS U CINCINNATI; Paris P, 1963, T ASME D, V85, P528; PENG SJ, 1984, AFRPLTR84036; Stevenson A., 1985, Intl Adhes. Adhes., V5, P81, DOI 10.1016-0143-7496(85)90020-X; STEVENSON A, 1987, J ADHESION, V21, P313, DOI 10.1080-0021846870807497899
Modeling cathodic weakening of rubber-steel adhesive bonds as liquid-solid reactions
No full textIn order to predict the loss of adhesion in adhesive bonded joints under cathodic conditions, empirical and semi-empirical approaches were previously implemented by Hamade and coworkers. In this paper, a method is presented to estimate bond weakening progress via numerical simulations after being modeled as a liquid-solid chemical reactor. The diffusion and chemical reaction mechanisms involved in bond weakening are mathematically represented via a simplified, 2 partial differential equations (p.d.e.) boundary value problem (BVP) which is a reduced version of the more complex electrochemical formulation needed to fully describe the chemistry at the bondline under cathodic conditions. The model presented is analytical-empirical hybrid formulation solvable by numerical methods and is made possible by the empirical knowledge developed previously by Hamade and coworkers regarding the dependence of the diffusion and chemical reaction parameters on cathodic conditions. The findings support that weakening is governed by a chemical reaction-controlled mechanism at relatively short distances and by a diffusion-controlled mechanism as the degraded front propagates. The numerical model is validated using experimental weakening data collected previously.The numerical solutions provide estimates of the life of the bonded joint (weakened length vs. time) asfunction of cathodic parameters. Koninklijke Brill NV, Leiden, 2012 © 2012 Copyright Taylor and Francis Group, LLC.BOERIO FJ, 1989, J ADHESION, V30, P119, DOI 10.1080-00218468908048201; Furbeth W, 2000, PROG ORG COAT, V39, P23, DOI 10.1016-S0300-9440(00)00095-3; Hamade RF, 2007, INT J ADHES ADHES, V27, P108, DOI 10.1016-j.ijadhadh.2006.01.002; Hamade RF, 2008, J ADHES SCI TECHNOL, V22, P775, DOI 10.1163-156856108X295374; HAMADEH RF, 1989, J ADHES SCI TECHNOL, V3, P421, DOI 10.1163-156856189X00317; ISHIDA M, 1968, AICHE J, V14, P311, DOI 10.1002-aic.690140218; KOZINSKI SE, 1990, J ADHES SCI TECHNOL, V4, P131, DOI 10.1163-156856190X00153; Leidheiser H. Jr., 1987, Journal of Adhesion Science and Technology, V1, DOI 10.1163-156856187X00094; Levenspiel O, 1999, CHEM REACTION ENG; Moiseev Y. V., 1987, CHEM RESISTANCE POLY, P180; TURNBULL A, 1986, CORROS SCI, V26, P601, DOI 10.1016-0010-938X(86)90027-2; Vetter K. J., 1976, ELECTROCHEMICAL KINE; WEN CY, 1968, IND ENG CHEM, V60, P34, DOI 10.1021-ie50705a0070
Frequency and phase modulation performance of an injection-locked CW magnetron.
No full textIt is demonstrated that the output of a 2.45-GHz magnetron operated as a current-controlled oscillator through its pushing characteristic can lock to injection signals in times of the order of 100-500 ns depending on injection power, magnetron heater power, load impedance, and frequency offset of the injection frequency from the natural frequency of the magnetron. Accordingly, the magnetron can follow frequency and phase modulations of the injection signal, behaving as a narrow-band amplifier. The transmission of phase-shift-keyed data at 2 Mb/s has been achieved. Measurements of the frequency response and anode current after a switch of phase as a function of average anode current and heater power give new insight into the locking mechanisms and the noise characteristics of magnetrons
The 'true use of reading' : Sarah Fielding and mid eighteenth-century literary strategies.
No full textPhDThe aim of this thesis is to explore, by examining her life and
works, how Sarah Fielding (1710-68) established her identity as an author.
The definition of her role involves her notions of the functions of
writing and reading.
Sarah Fielding attempts to invite readers to form a sense of ties
by tacit understanding of her messages. As she believes that a work
of literature is produced through collaboration between the writer and
the reader, it is an important task in her view to show her attentiveness
toward reading practice. In her consideration of reading, she has two
distinct, even opposite views of her audience: on the one hand a familiar
and limited circle of readers with shared moral and cultural values and
on the other potential readers among the unknown mass of people. The
dual targets direct her to devise various strategies. She tries to
appeal to those who can endorse and appreciate her moral values as well
as her learning. Her writings and letters testify that she is sensitive
to the demands of the literary market, trying to lead the taste of readers
by inventing new forms.
The thesis opens with an overview of Sarah Fielding's career,
followed by a consideration of her critical attention to the roles of
reading. I go on to examine the narrative structures and strategies
she deploys, with a particular emphasis on her use of the epistolary
method. The following chapter deals with her attention to the reading
of the moral message tangibly embodied in her educational writing. It
is followed by an analysis of the activity which earned her a reputation
as a learned woman. Various as the forms of her works are, they invariably
reflect her attempt to balance herself between the two demands of
inventiveness and familiarity
Human,climatic and oceanographic influences on the marine environment of Pohnpei, Federated States of Micronesia
No full textFile PB200200 could not be included in folder EFR1. Full data available on disc with print copy held at the University of Waikato Library.Coral reefs and marine resources are culturally, as well as economically, vital to Pohnpei, situated in the Federated States of Micronesia (FSM). Farming and fishing are the main sources of livelihood for most Pohnpeian communities. Pohnpei has eleven Marine Protected Areas (MPAs) where nine are situated in the Pohnpei Island Lagoon and two MPAs on the outer low-lying atolls. Like many other Pacific Island countries Pohnpei is on the verge of creating more MPAs. However, the marine environment continues to be significantly threatened by human and natural influences. The recognised threats are yet to be methodically investigated.
This thesis used a combination of sediment, coral, fish, climatic, and oceanographic data, and focused on the Pohnpei Lagoon, examining a range of natural and human issues in the marine environment both at the local level (focusing on that within the Pohnpei Lagoon) and regional level (focusing on the western Pacific region).
Evidence from historical, archaeological, and modern experience has influenced various marine impacts that have altered the coastline and the marine environment of the Pohnpei Lagoon. Humans have greatly impacted on the coral diversity and fish populations in the Pohnpei Lagoon by over-fishing and contributing to accelerated sediment inputs. My study findings shows that that increased sea surface temperature (SST) caused by El Ni o events is not the only cause of coral bleaching, but also cooling of SST, and other human factors. However, when corals bleach they recover by symbiont shuffling . This is an ingenious way in which corals host one or more varieties of their zooxanthelle (Symbiodinium symbiont clades) that are more tolerant of the stress caused by increased SST and human factors.
The recognised natural climatic variability, particularly the El Ni o/Southern Oscillation (ENSO), may pose a significant threat to the Pohnpei Lagoon. El Ni o events are associated with: a change in trade winds and stronger wind gusts attributed to typhoons; lower rainfall causing drought; a decrease in SST attributed to cooling of the marine environment; increase of salinity in marine estuaries affecting development and recruitment of marine species communities; and a steep fall in sea level exposing corals to other elements. The various on-going human threats and El Ni o-like conditions have caused giant clams (Tridacna gigas) to become extinct, have endangered herbivorous fish populations, and caused coral bleaching by cooling of SST.
Although high SSTs are normally blamed for coral bleaching, the last major bleaching event in Pohnpei (2002) was likely to be due to a reduction in salinity (freshwater runoff and lower sea level), and there has been strong recovery. However, decreasing water temperatures rather than increases of SSTs may contribute to coral bleaching in the Pohnpei Lagoon and the Micronesian region. The Micronesian region appears to have suffered relatively few episodes of regional coral bleaching events. This is due to the Western Pacific Warm Pool (WPWP) where sea surface temperatures exceed 29 C but also where various feedback mechanisms limit the maximum SSTs.
The management aims of Pohnpei's MPAs are to move forward, while still respecting traditional practices. However, a lack of scientific monitoring, technical support and funding restricts our understanding of human and natural influences on the existing MPAs and the Pohnpei Lagoon. With respect to our policy makers the findings of the present research have implications on the future work in Pohnpei's marine environment and for policy makers, to make more-informed decisions before establishing new MPAs.
My key recommendations were: 1.) Integrate coral and fish monitoring during and after El Ni o events to understand El Ni o effects on the Pohnpei environment. 2.) Undertake herbivorous fish investigation into their populations inside and outside the MPAs. 3.) Do not cut down vegetation along coastline areas, as it prevents erosion 4.) Investigate Symbiodinium coral clades in Pohnpei Lagoon and the outer low-lying atolls
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