1,125 research outputs found
Lipase inhibition attenuates the acute inhibitory effects of oral fat on food intake in healthy subjects
The lipase inhibitor, orlistat, is used in the treatment of obesity and reduces fat absorption by about 30%. However, the mean weight loss induced by orlistat is less than expected for the degree of fat malabsorption. It was hypothesised that lipase inhibition with orlistat attenuates the suppressive effects of oral fat on subsequent energy intake in normal-weight subjects. Fourteen healthy, lean subjects (nine males, five females; aged 25 +/- 1.3 years) were studied twice, in a double-blind fashion. The subjects received a high-fat yoghurt 'preload' (males 400 g (2562 kJ); females 300 g (1923 kJ)), containing orlistat (120 mg) on one study day (and no orlistat on the other 'control' day), 30 min before ad libitum access to food and drinks; energy intake was assessed during the following 8 h. Blood samples were taken at regular intervals for the measurement of plasma cholecystokinin (CCK). Each subject performed a 3 d faecal fat collection following each study. Energy intake during the day was greater following orlistat (10,220 (SEM 928) kJ) v. control (9405 (SEM 824) kJ) (P=0.02). On both days plasma CCK increased (P<0.05) after the preload. Plasma CCK 20 min following ingestion of the preload was less after orlistat (4.1 (SEM 0.9) pmol/l) v. control (5.3 (SEM 0.9) pmol/l (P=0.028); however there was no difference in the area under the curve 0-510 min between the two study days. Fat excretion was greater following orlistat (1017 (SEM 168) kJ) v. control (484 (SEM 90) kJ) (P=0.004). In conclusion, in healthy, lean subjects the acute inhibitory effect of fat on subsequent energy intake is attenuated by orlistat and the increase in energy intake approximates the energy lost due to fat malabsorption.Deirdre OāDonovan, Christine Feinle-Bisset, Judith Wishart and Michael Horowit
Finite-temperature trapped dipolar Bose gas
We develop a finite temperature Hartree theory for the trapped dipolar Bose
gas. We use this theory to study thermal effects on the mechanical stability of
the system and density oscillating condensate states. We present results for
the stability phase diagram as a function of temperature and aspect ratio. In
oblate traps above the critical temperature for condensation we find that the
Hartree theory predicts significant stability enhancement over the
semiclassical result. Below the critical temperature we find that thermal
effects are well described by accounting for the thermal depletion of the
condensate. Our results also show that density oscillating condensate states
occur over a range of interaction strengths that broadens with increasing
temperature.Comment: 10 pages, 7 figure
Cost/benefit analysis of advanced materials technologies for future aircraft turbine engines
The cost/benefits of advance commercial gas turbine materials are described. Development costs, estimated payoffs and probabilities of success are discussed. The materials technologies investigated are: (1) single crystal turbine blades, (2) high strength hot isostatic pressed turbine disk, (3) advanced oxide dispersion strengthened burner liner, (4) bore entry cooled hot isostatic pressed turbine disk, (5) turbine blade tip - outer airseal system, and (6) advance turbine blade alloys
Oral and Gastrointestinal Sensing of Dietary Fat and Appetite Regulation in Humans: Modification by Diet and Obesity
Dietary fat interacts with receptors in both the oral cavity and the gastrointestinal (GI) tract to regulate fat and energy intake. This review discusses recent developments in our understanding of the mechanisms underlying the effects of fat, through its digestive products, fatty acids (FAs), on GI function and energy intake, the role of oral and intestinal FA receptors, and the implications that changes in oral and small intestinal sensitivity in response to ingested fat may have for the development of obesity
Energy Efficient Engine Flight Propulsion System Preliminary Analysis and Design Report
The final design and analysis of the flight propulsion system is presented. This system is the conceptual study engine defined to meet the performance, economic and environmental goals established for the Energy Efficient Engine Program. The design effort included a final definition of the engine, major components, internal subsystems, and nacelle. Various analytical representations and results from component technology programs are used to verify aerodynamic and structural design concepts and to predict performance. Specific design goals and specifications, reflecting future commercial aircraft propulsion system requirements for the mid-1980's, are detailed by NASA and used as guidelines during engine definition. Information is also included which details salient results from a separate study to define a turbofan propulsion system, known as the maximum efficiency engine, which reoptimized the advanced fuel saving technologies for improved fuel economy and direct operating costs relative to the flight propulsion system
Single and Multiple Vortex Rings in Three-Dimensional Bose-Einstein Condensates: Existence, Stability and Dynamics
In the present work, we explore the existence, stability and dynamics of
single and multiple vortex ring states that can arise in Bose-Einstein
condensates. Earlier works have illustrated the bifurcation of such states, in
the vicinity of the linear limit, for isotropic or anisotropic
three-dimensional harmonic traps. Here, we extend these states to the regime of
large chemical potentials, the so-called Thomas-Fermi limit, and explore their
properties such as equilibrium radii and inter-ring distance, for multi-ring
states, as well as their vibrational spectra and possible instabilities. In
this limit, both the existence and stability characteristics can be partially
traced to a particle picture that considers the rings as individual particles
oscillating within the trap and interacting pairwise with one another. Finally,
we examine some representative instability scenarios of the multi-ring dynamics
including breakup and reconnections, as well as the transient formation of
vortex lines.Comment: 10 pages, 8 figure
Wedgebox analysis of four-lepton events from neutralino pair production at the LHC
`Wedgebox' plots constructed by plotting the di-electron invariant mass
versus the di-muon invariant mass from pp -> e^+e^- mu^+ mu^- + missing energy
signature LHC events. Data sets of such events are obtained across the MSSM
input parameter space in event-generator simulations, including cuts designed
to remove SM backgrounds. Their study reveals several general features:
(1)Regions in the MSSM input parameter space where a sufficient number of
events are expected so as to be able to construct a clear wedgebox plot are
delineated. (2)The presence of box shapes on a wedgebox plot either indicates
the presence of heavy Higgs bosons decays or restricts the location to a quite
small region of low \mu and M_2 values \lsim 200 GeV, a region denoted as the
`lower island'. In this region, wedgebox plots can be quite complicated and
change in pattern rather quickly as one moves around in the (\mu, M_2) plane.
(3)Direct neutralino pair production from an intermediate Z^{0*} may only
produce a wedge-shape since only \widetilde{\chi}_2^0\widetilde{\chi}_3^0
decays can contribute significantly. (4)A double-wedge or
wedge-protruding-from-a-box pattern on a wedgebox plot, which results from
combining a variety of MSSM production processes, yields three distinct
observed endpoints, almost always attributable to \widetilde{\chi}_{2,3,4}^0
\to \widetilde{\chi}_1^0 \ell^+\ell^- decays, which can be utilized to
determine a great deal of information about the neutralino and slepton mass
spectra and related MSSM input parameters. Wedge and double-wedge patterns are
seen in wedgebox plots in another region of higher \mu and M_2 values, denoted
as the`upper island.' Here the pattern is simpler and more stable as one moves
across the (\mu, M_2) input parameter space.Comment: 28 pages (LaTeX), 8 figures (encapsulated postscript
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