Design optimization of rear uprights for UniMAP Automotive Racing Team Formula SAE racing car
NASA Astrophysics Data System (ADS)
Azmeer, M.; Basha, M. H.; Hamid, M. F.; Rahman, M. T. A.; Hashim, M. S. M.
2017-10-01
In an automobile, the rear upright are used to provide a physical mounting and links the suspension arms to the hub and wheel assembly. In this work, static structural and shape optimization analysis for rear upright for UniMAP’s Formula SAE racing car had been done using ANSYS software with the objective to reduce weight while maintaining the structural strength of the vehicle upright. During the shape optimization process, the component undergoes 25%, 50% and 75 % weight reduction in order to find the best optimal shape of the upright. The final design of the upright is developed considering the weight reduction, structural integrity and the manufacturability. The final design achieved 21 % weight reduction and is able to withstand several loads.
USDA-ARS?s Scientific Manuscript database
Weight reduction is recommended to reduce obesity-related health disorders. This study investigated the differential effects of weight reduction through caloric restriction and/or physical activity on bone structure and molecular characteristics of bone metabolism in an obese rat model. We tested th...
Research requirements to reduce empty weight of helicopters by use of advanced materials
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hoffstedt, D.J.
1976-12-01
Utilization of the new, lightweight, high-strength, aerospace structural-composite (filament/matrix) materials, when specifically designed into a new aircraft, promises reductions in structural empty weight of 12% at recurring costs competetive with metals. A program of basic and applied research and demonstration is identified with the objective of advancing the state of the art to the point where civil helicopters are confidently designed, produced, certified, and marketed by 1985. A structural empty-weight reduction of 12% was shown to significantly reduce energy consumption in modern high-performance helicopters.
NASA Astrophysics Data System (ADS)
Luthfi, A.; Subhan, K. A.; Eko H, B.; Sanggar, D. R.; Pramadihanto, D.
2018-04-01
Lightweight construction and energy efficiency play an important role in humanoid robot development. The application of computer-aided engineering (CAE) in the development process is one of the possibilities to achieve the appropriate reduction of the weight. This paper describes a method to generate an optimum lightweight legs structure design based on critical posture during walking locomotion in A-FLoW Humanoid robot.The criticalposture can be obtained from the highest forces and moments in each joint of the robot body during walking locomotion. From the finite element analysis (FEA) result can be realized leg structure design of A-FLoW humanoid robot with a maximum displacement value of 0.05 mmand weight reduction about 0.598 Kg from the thigh structure and a maximum displacement value of 0,13 mmand weight reduction about 0.57 kg from the shin structure.
Hybrid Wing-Body (HWB) Pressurized Fuselage Modeling, Analysis, and Design for Weight Reduction
NASA Technical Reports Server (NTRS)
Mukhopadhyay, Vivek
2012-01-01
This paper describes the interim progress for an in-house study that is directed toward innovative structural analysis and design of next-generation advanced aircraft concepts, such as the Hybrid Wing-Body (HWB) and the Advanced Mobility Concept-X flight vehicles, for structural weight reduction and associated performance enhancement. Unlike the conventional, skin-stringer-frame construction for a cylindrical fuselage, the box-type pressurized fuselage panels in the HWB undergo significant deformation of the outer aerodynamic surfaces, which must be minimized without significant structural weight penalty. Simple beam and orthotropic plate theory is first considered for sizing, analytical verification, and possible equivalent-plate analysis with appropriate simplification. By designing advanced composite stiffened-shell configurations, significant weight reduction may be possible compared with the sandwich and ribbed-shell structural concepts that have been studied previously. The study involves independent analysis of the advanced composite structural concepts that are presently being developed by The Boeing Company for pressurized HWB flight vehicles. High-fidelity parametric finite-element models of test coupons, panels, and multibay fuselage sections, were developed for conducting design studies and identifying critical areas of potential failure. Interim results are discussed to assess the overall weight/strength advantages.
Research requirements to reduce empty weight of helicopters by use of advanced materials
NASA Technical Reports Server (NTRS)
Hoffstedt, D. J.
1976-01-01
Utilization of the new, lightweight, high-strength, aerospace structural-composite (filament/matrix) materials, when specifically designed into a new aircraft, promises reductions in structural empty weight of 12 percent at recurring costs competive with metals. A program of basic and applied research and demonstration is identified with the objective of advancing the state of the art to the point where civil helicopters are confidently designed, produced, certified, and marketed by 1985. A structural empty-weight reduction of 12 percent was shown to significantly reduce energy consumption in modern high-performance helicopters.
Internal Structural Design of the Common Research Model Wing Box for Aeroelastic Tailoring
NASA Technical Reports Server (NTRS)
Jutte, Christine V.; Stanford, Bret K.; Wieseman, Carol D.
2015-01-01
This work explores the use of alternative internal structural designs within a full-scale wing box structure for aeroelastic tailoring, with a focus on curvilinear spars, ribs, and stringers. The baseline wing model is a fully-populated, cantilevered wing box structure of the Common Research Model (CRM). Metrics of interest include the wing weight, the onset of dynamic flutter, and the static aeroelastic stresses. Twelve parametric studies alter the number of internal structural members along with their location, orientation, and curvature. Additional evaluation metrics are considered to identify design trends that lead to lighter-weight, aeroelastically stable wing designs. The best designs of the individual studies are compared and discussed, with a focus on weight reduction and flutter resistance. The largest weight reductions were obtained by removing the inner spar, and performance was maintained by shifting stringers forward and/or using curvilinear ribs: 5.6% weight reduction, a 13.9% improvement in flutter speed, but a 3.0% increase in stress levels. Flutter resistance was also maintained using straight-rotated ribs although the design had a 4.2% lower flutter speed than the curved ribs of similar weight and stress levels were higher. For some configurations, the differences between curved and straight ribs were smaller, which provides motivation for future optimization-based studies to fully exploit the trade-offs.
Hybrid Wing-Body Pressurized Fuselage and Bulkhead, Design and Optimization
NASA Technical Reports Server (NTRS)
Mukhopadhyay, Vivek
2013-01-01
The structural weight reduction of a pressurized Hybrid Wing-Body (HWB) fuselage is a serious challenge. Hence, research and development are presently being continued at NASA under the Environmentally Responsible Aviation (ERA) and Subsonic Fixed Wing (SFW) projects in collaboration with the Boeing Company, Huntington Beach and Air Force Research Laboratory (AFRL). In this paper, a structural analysis of the HWB fuselage and bulkhead panels is presented, with the objectives of design improvement and structural weight reduction. First, orthotropic plate theories for sizing, and equivalent plate analysis with appropriate simplification are considered. Then parametric finite-element analysis of a fuselage section and bulkhead are conducted using advanced stitched composite structural concepts, which are presently being developed at Boeing for pressurized HWB flight vehicles. With this advanced stiffened-shell design, structural weights are computed and compared to the thick sandwich, vaulted-ribbed-shell, and multi-bubble stiffened-shell structural concepts that had been studied previously. The analytical and numerical results are discussed to assess the overall weight/strength advantages.
Numerical and Experimental Evaluation on the Residual Stresses of Welded Joints
NASA Astrophysics Data System (ADS)
Huh, Sun Chul; Park, Wonjo; Yang, Haesug; Jung, Haeyoung; Kim, Chuyoung
Wings for the defense industry such as fighters, missiles, and rockets should show no deformation or damage on the structure. The structures of existing wings had holes for weight reduction. The plates and frames were fixed with rivets or screws, which limited the weight reduction possible. In this study, an improvement was made in jointing methods through EB welding and laser welding. Welding strength was measured through tension testing. In addition, finite element analysis was performed for the welding process so as to deduce the optimum welding condition.
NASA Heavy Lift Rotorcraft Systems Investigation
NASA Technical Reports Server (NTRS)
Johnson, Wayne; Yamauchi, Gloria K.; Watts, Michael E.
2005-01-01
The NASA Heavy Lift Rotorcraft Systems Investigation examined in depth several rotorcraft configurations for large civil transport, designed to meet the technology goals of the NASA Vehicle Systems Program. The investigation identified the Large Civil Tiltrotor as the configuration with the best potential to meet the technology goals. The design presented was economically competitive, with the potential for substantial impact on the air transportation system. The keys to achieving a competitive aircraft were low drag airframe and low disk loading rotors; structural weight reduction, for both airframe and rotors; drive system weight reduction; improved engine efficiency; low maintenance design; and manufacturing cost comparable to fixed-wing aircraft. Risk reduction plans were developed to provide the strategic direction to support a heavy-lift rotorcraft development. The following high risk areas were identified for heavy lift rotorcraft: high torque, light weight drive system; high performance, structurally efficient rotor/wing system; low noise aircraft; and super-integrated vehicle management system.
A mass reduction effort of the electric and hybrid vehicle. [composite door panels
NASA Technical Reports Server (NTRS)
Freeman, R. B.; Jahnle, H. A.
1980-01-01
Weight reduction, cost competitiveness, and elimination of the intrusion beam resulted from the redesign and fabrication using composite materials of the door outer panel and intrusion beam from a Chevrolet Impala. The basis of the redesign involved replacing these two steel parts with a single compression molding using the unique approach of simultaneously curing a sheet molding compound outside panel with a continuous glass fiber intrusion strap. A weight reduction of nearly 11 pounds per door was achieved. Additional weight savings are possible by taking advantage of the elimination of the intrusion beam to design thinner door structures. The parts consolidation approach allows the composite structure to be cost competitive with the original steel design for both the lower production car models and for the near to midterm production vehicles using current state of the art composite production techniques. The design, prototype fabrication, costing, material, properties and compression molding production requirements are discussed.
Designs and Technology Requirements for Civil Heavy Lift Rotorcraft
NASA Technical Reports Server (NTRS)
Johnson, Wayne; Yamauchi, Gloria K.; Watts, Michael E.
2006-01-01
The NASA Heavy Lift Rotorcraft Systems Investigation examined in depth several rotorcraft configurations for large civil transport, designed to meet the technology goals of the NASA Vehicle Systems Program. The investigation identified the Large Civil Tiltrotor as the configuration with the best potential to meet the technology goals. The design presented was economically competitive, with the potential for substantial impact on the air transportation system. The keys to achieving a competitive aircraft were low drag airframe and low disk loading rotors; structural weight reduction, for both airframe and rotors; drive system weight reduction; improved engine efficiency; low maintenance design; and manufacturing cost comparable to fixed-wing aircraft. Risk reduction plans were developed to provide the strategic direction to support a heavy-lift rotorcraft development. The following high risk areas were identified for heavy lift rotorcraft: high torque, light weight drive system; high performance, structurally efficient rotor/wing system; low noise aircraft; and super-integrated vehicle management system.
Aerodynamic and structural studies of joined-wing aircraft
NASA Technical Reports Server (NTRS)
Kroo, Ilan; Smith, Stephen; Gallman, John
1991-01-01
A method for rapidly evaluating the structural and aerodynamic characteristics of joined-wing aircraft was developed and used to study the fundamental advantages attributed to this concept. The technique involves a rapid turnaround aerodynamic analysis method for computing minimum trimmed drag combined with a simple structural optimization. A variety of joined-wing designs are compared on the basis of trimmed drag, structural weight, and, finally, trimmed drag with fixed structural weight. The range of joined-wing design parameters resulting in best cruise performance is identified. Structural weight savings and net drag reductions are predicted for certain joined-wing configurations compared with conventional cantilever-wing configurations.
Nontangent, Developed Contour Bulkheads for a Single-Stage Launch Vehicle
NASA Technical Reports Server (NTRS)
Wu, K. Chauncey; Lepsch, Roger A., Jr.
2000-01-01
Dry weights for single-stage launch vehicles that incorporate nontangent, developed contour bulkheads are estimated and compared to a baseline vehicle with 1.414 aspect ratio ellipsoidal bulkheads. Weights, volumes, and heights of optimized bulkhead designs are computed using a preliminary design bulkhead analysis code. The dry weights of vehicles that incorporate the optimized bulkheads are predicted using a vehicle weights and sizing code. Two optimization approaches are employed. A structural-level method, where the vehicle's three major bulkhead regions are optimized separately and then incorporated into a model for computation of the vehicle dry weight, predicts a reduction of4365 lb (2.2 %) from the 200,679-lb baseline vehicle dry weight. In the second, vehicle-level, approach, the vehicle dry weight is the objective function for the optimization. For the vehicle-level analysis, modified bulkhead designs are analyzed and incorporated into the weights model for computation of a dry weight. The optimizer simultaneously manipulates design variables for all three bulkheads to reduce the dry weight. The vehicle-level analysis predicts a dry weight reduction of 5129 lb, a 2.6% reduction from the baseline weight. Based on these results, nontangent, developed contour bulkheads may provide substantial weight savings for single stage vehicles.
NASA Technical Reports Server (NTRS)
Jutte, Christine V.; Stanford, Bret K.; Wieseman, Carol D.; Moore, James B.
2014-01-01
This work explores the use of tow steered composite laminates, functionally graded metals (FGM), thickness distributions, and curvilinear rib/spar/stringer topologies for aeroelastic tailoring. Parameterized models of the Common Research Model (CRM) wing box have been developed for passive aeroelastic tailoring trade studies. Metrics of interest include the wing weight, the onset of dynamic flutter, and the static aeroelastic stresses. Compared to a baseline structure, the lowest aggregate static wing stresses could be obtained with tow steered skins (47% improvement), and many of these designs could reduce weight as well (up to 14%). For these structures, the trade-off between flutter speed and weight is generally strong, although one case showed both a 100% flutter improvement and a 3.5% weight reduction. Material grading showed no benefit in the skins, but moderate flutter speed improvements (with no weight or stress increase) could be obtained by grading the spars (4.8%) or ribs (3.2%), where the best flutter results were obtained by grading both thickness and material. For the topology work, large weight reductions were obtained by removing an inner spar, and performance was maintained by shifting stringers forward and/or using curvilinear ribs: 5.6% weight reduction, a 13.9% improvement in flutter speed, but a 3.0% increase in stress levels. Flutter resistance was also maintained using straightrotated ribs although the design had a 4.2% lower flutter speed than the curved ribs of similar weight and stress levels were higher. These results will guide the development of a future design optimization scheme established to exploit and combine the individual attributes of these technologies.
Structural Configuration Systems Analysis for Advanced Aircraft Fuselage Concepts
NASA Technical Reports Server (NTRS)
Mukhopadhyay, Vivek; Welstead, Jason R.; Quinlan, Jesse R.; Guynn, Mark D.
2016-01-01
Structural configuration analysis of an advanced aircraft fuselage concept is investigated. This concept is characterized by a double-bubble section fuselage with rear mounted engines. Based on lessons learned from structural systems analysis of unconventional aircraft, high-fidelity finite-element models (FEM) are developed for evaluating structural performance of three double-bubble section configurations. Structural sizing and stress analysis are applied for design improvement and weight reduction. Among the three double-bubble configurations, the double-D cross-section fuselage design was found to have a relatively lower structural weight. The structural FEM weights of these three double-bubble fuselage section concepts are also compared with several cylindrical fuselage models. Since these fuselage concepts are different in size, shape and material, the fuselage structural FEM weights are normalized by the corresponding passenger floor area for a relative comparison. This structural systems analysis indicates that an advanced composite double-D section fuselage may have a relative structural weight ratio advantage over a conventional aluminum fuselage. Ten commercial and conceptual aircraft fuselage structural weight estimates, which are empirically derived from the corresponding maximum takeoff gross weight, are also presented and compared with the FEM- based estimates for possible correlation. A conceptual full vehicle FEM model with a double-D fuselage is also developed for preliminary structural analysis and weight estimation.
Optimal Network-based Intervention in the Presence of Undetectable Viruses.
Youssef, Mina; Scoglio, Caterina
2014-08-01
This letter presents an optimal control framework to reduce the spread of viruses in networks. The network is modeled as an undirected graph of nodes and weighted links. We consider the spread of viruses in a network as a system, and the total number of infected nodes as the state of the system, while the control function is the weight reduction leading to slow/reduce spread of viruses. Our epidemic model overcomes three assumptions that were extensively used in the literature and produced inaccurate results. We apply the optimal control formulation to crucial network structures. Numerical results show the dynamical weight reduction and reveal the role of the network structure and the epidemic model in reducing the infection size in the presence of indiscernible infected nodes.
Optimal Network-based Intervention in the Presence of Undetectable Viruses
Youssef, Mina; Scoglio, Caterina
2014-01-01
This letter presents an optimal control framework to reduce the spread of viruses in networks. The network is modeled as an undirected graph of nodes and weighted links. We consider the spread of viruses in a network as a system, and the total number of infected nodes as the state of the system, while the control function is the weight reduction leading to slow/reduce spread of viruses. Our epidemic model overcomes three assumptions that were extensively used in the literature and produced inaccurate results. We apply the optimal control formulation to crucial network structures. Numerical results show the dynamical weight reduction and reveal the role of the network structure and the epidemic model in reducing the infection size in the presence of indiscernible infected nodes. PMID:25422579
Post-impact behavior of composite solid rocket motor cases
NASA Technical Reports Server (NTRS)
Highsmith, Alton L.
1992-01-01
In recent years, composite materials have seen increasing use in advanced structural applications because of the significant weight savings they offer when compared to more traditional engineering materials. The higher cost of composites must be offset by the increased performance that results from reduced structural weight if these new materials are to be used effectively. At present, there is considerable interest in fabricating solid rocket motor cases out of composite materials, and capitalizing on the reduced structural weight to increase rocket performance. However, one of the difficulties that arises when composite materials are used is that composites can develop significant amounts of internal damage during low velocity impacts. Such low velocity impacts may be encountered in routine handling of a structural component like a rocket motor case. The ability to assess the reduction in structural integrity of composite motor cases that experience accidental impacts is essential if composite rocket motor cases are to be certified for manned flight. The study described herein was an initial investigation of damage development and reduction of tensile strength in an idealized composite subjected to low velocity impacts.
State-of-the-art of the Space Shuttle External Tank
NASA Astrophysics Data System (ADS)
Ronquillo, L.
The designation, structure and environment of the External Tank (ET) of the Space Shuttle as well as plans for increasing the facilities and tooling to meet the required production rate capability of 40 or more ETs per year in 1992 are described. Special attention is given to the weight reduction of ET, since 1.0 lb of weight saved on the empty structure translates into about 0.9 lb of additional payload. To determine the potentiality of the weight reduction, structural tests were conducted. It was found that the tank could function properly with interior support structures reduced, and selected stringers eliminated. It is reported that an alternate sprayable polyisocyanurate foam capable of replacing a foam insulation over ablator bilayer thermoprotective composite on the aft-dome of the tank was developed: a commercially available material was modified to adhere to the -423 F aluminum substrate in the 2000 F engine-plume radiant-heat environment. It is mentioned that the weight savings program which started in Oct. 1975 saved 6000 lb by Jan. 1979. To reduce weld testing time and gain 100 times the accuracy, an electromechanical check system was developed. Problems of using robots are discussed.
Advanced composite vertical stabilizer for DC-10 transport aircraft
NASA Technical Reports Server (NTRS)
Stephens, C. O.
1979-01-01
Structural design, tooling, fabrication, and test activities are reported for a program to develop an advanced composite vertical stabilizer (CVS) for the DC 10 Commercial Transport Aircraft. Structural design details are described and the status of structural and weight analyses are reported. A structural weight reduction of 21.7% is currently predicted. Test results are discussed for sine wave stiffened shear webs containing representative of the CVS spar webs and for lightning current transfer and tests on a panel representative of the CVS skins.
Comparison between neurectomy and botulinum toxin A injection for denervated skeletal muscle.
Tsai, Feng-Chou; Hsieh, Ming-Shium; Chou, Chih-Ming
2010-08-01
Neurectomy and botulinum toxin A (BoNT-A) injection cause denervated muscle atrophy, but questions remain about their clinical utility. We investigated time-series alterations of rat muscle weight, functional deficits, signaling pathways, and microscopic structures, to gain an understanding of the clinical implications. Between 2008 and 2009, the maximal calf circumference of patients for calf reduction either by neurectomy or BoNT-A injections were recorded for study. A rat skeletal muscle model was established through repeated or dose-adjusted BoNT-A injections and neurectomy. The survival, apoptosis pathways, functional deficits, and microscopic structures were investigated using Western blot, sciatic functional index (SFI), and transmission electron microscopy (TEM), respectively. The rat muscle weight ratio of the BoNT-A group had recovered to 89.3 +/- 3.8% by week 58, but it never recovered in the neurectomy group. Muscle weight reduction by BoNT-A not only depended on the dose, but additive effects were also obtained through repeated injections. Rat SFI demonstrated rapid recovery in both groups. Molecular expressions showed a coherent and biphasic pattern. p-Akt and apoptosis-inducing factor (AIF) were upregulated significantly, with a peak at 8 weeks in the neurectomy group (p < 0.01), but cleaved caspase-9 and caspase-3 showed no significant changes in either group. TEM findings showed irreversible and reversible inner-structure disruption and sarcomere discontinuity in the neurectomy and BoNT-A groups, respectively. We demonstrated that denervation induced lasting muscle weight and structural changes of different degrees. Muscle weight reduction by BoNT-A was related to frequency and dose. AIF-mediated caspase-independent apoptosis was significantly different for neurectomy and BoNT-A injection.
FinalReport-DOE BES DMSE-UNR-QLi
DOE Office of Scientific and Technical Information (OSTI.GOV)
Li, Qizhen
The primary goal of this project is to explore the fundamental deformation and failure mechanisms for magnesium with a hexagonal close packed (HCP) crystal structure. It is critical to perform this project for a number of reasons. First, magnesium is the lightest structural metal and its application in various structural components can save the final component weight. Second, the weight reduction from the usage of magnesium-based structural components in transportation vehicles such as automobiles and aircrafts can improve fuel efficiency and reduce the greenhouse gas emissions. Third, structural components often experience dynamic loading such as cyclic loading conditions. Fourth, magnesiummore » with a HCP crystal structure generally has its special deformation responses under loading conditions. This project investigated magnesium based materials (magnesium single crystal, pure polycrystalline magnesium, and some magnesium alloys) under various loading conditions, and also explored some processing routes to manipulate the microstructure and mechanical properties of magnesium. The research results were published in a number of articles and also disseminated through presentations in various conferences such as TMS annual meetings, MRS meetings, the international Plasticity conferences, the Pacific Rim International Congress on Advanced Materials and Processing, and AeroMat. In addition to the contribution to the research/academic community, this project is also beneficial to the general public. With the actual usage of magnesium in the passenger cars, the weight reduction and fuel consumption reduction will save the fuel bill of individual owners.« less
Liang, Fu-Wen; Chou, Hung-Chieh; Chiou, Shu-Ti; Chen, Li-Hua; Wu, Mei-Hwan; Lue, Hung-Chi; Chiang, Tung-Liang; Lu, Tsung-Hsueh
2018-06-01
A yearly increase in the proportion of very low birth weight (VLBW) live births has resulted in the slowdown of decreasing trends in crude infant mortality rates (IMRs). In this study, we examined the trends in birth weight-specific as well as birth weight-adjusted IMRs in Taiwan. We linked three nationwide datasets, namely the National Birth Reporting Database, National Birth Certification Registry, and National Death Certification Registry databases, to calculate the IMRs according to the birth weight category. Trend tests and mortality rate ratios in the periods 2010-2011 and 2004-2005 were used to examine the extent of reduction in birth weight-specific and birth weight-adjusted IMRs. The proportion of VLBW (<1500 g) infants among live births increased from 0.78% in 2004-2005 to 0.89% in 2010-2011, thus exhibiting a 15% increase. The extents of the decreases in birth weight-specific IMRs in the 500-999, 1000-1499, 1500-1999, 2000-2499, and 2500-2999 g birth weight categories were 15%, 33%, 43%, 30%, and 28%, respectively, from 2004-2005 to 2010-2011. The reduction in IMR in each birth weight category was larger than the reduction in the crude IMR (13%). By contrast, the IMR in the <500 g birth weight category exhibited a 56% increase during the study period. The IMRs were calculated by excluding all live births with a birth weight of <500 g. The birth weight-adjusted IMRs, which were calculated using a standard birth weight distribution structure for adjustment, exhibited similar extent reductions. In countries with an increasing proportion of VLBW live births, birth weight-specific or -adjusted IMRs are more appropriate than other indices for accurately assessing the real extent of reduction in IMRs. Copyright © 2017. Published by Elsevier B.V.
Interior noise control prediction study for high-speed propeller-driven aircraft
NASA Technical Reports Server (NTRS)
Rennison, D. C.; Wilby, J. F.; Marsh, A. H.; Wilby, E. G.
1979-01-01
An analytical model was developed to predict the noise levels inside propeller-driven aircraft during cruise at M = 0.8. The model was applied to three study aircraft with fuselages of different size (wide body, narrow body and small diameter) in order to determine the noise reductions required to achieve the goal of an A-weighted sound level which does not exceed 80 dB. The model was then used to determine noise control methods which could achieve the required noise reductions. Two classes of noise control treatments were investigated: add-on treatments which can be added to existing structures, and advanced concepts which would require changes to the fuselage primary structure. Only one treatment, a double wall with limp panel, provided the required noise reductions. Weight penalties associated with the treatment were estimated for the three study aircraft.
NASA Technical Reports Server (NTRS)
Brooks, W. A., Jr.; Mathauser, E. E.; Pride, R. A.
1972-01-01
The use of composite materials to selectively reinforce metallic structures provides a low-cost way to reduce weight and a means of minimizing the risks usually associated with the introduction of new materials. An overview is presented of the NASA Langley Research Center programs to identify the advantages and to develop the potential of the selective reinforcement approach to the use of composites. These programs have shown that selective reinforcement provides excellent strength and stiffness improvements to metallic structures. Significant weight savings can be obtained in a cost effective manner. Flight service programs which have been initiated to validate further the merits of selective reinforcement are described.
Mechanistic investigation of Fe(III) oxide reduction by low molecular weight organic sulfur species
NASA Astrophysics Data System (ADS)
Eitel, Eryn M.; Taillefert, Martial
2017-10-01
Low molecular weight organic sulfur species, often referred to as thiols, are known to be ubiquitous in aquatic environments and represent important chemical reductants of Fe(III) oxides. Thiols are excellent electron shuttles used during dissimilatory iron reduction, and in this capacity could indirectly affect the redox state of sediments, release adsorbed contaminants via reductive dissolution, and influence the carbon cycle through alteration of bacterial respiration processes. Interestingly, the reduction of Fe(III) oxides by thiols has not been previously investigated in environmentally relevant conditions, likely due to analytical limitations associated with the detection of thiols and their oxidized products. In this study, a novel electrochemical method was developed to simultaneously determine thiol/disulfide pair concentrations in situ during the reduction of ferrihydrite in batch reactors. First order rate laws with respect to initial thiol concentration were confirmed for Fe(III) oxyhydroxide reduction by four common thiols: cysteine, homocysteine, cysteamine, and glutathione. Zero order was determined for both Fe(III) oxyhydroxide and proton concentration at circumneutral pH. A kinetic model detailing the molecular mechanism of the reaction was optimized with proposed intermediate surface structures. Although metal oxide overall reduction rate constants were inversely proportional to the complexity of the thiol structure, the extent of metal reduction increased with structure complexity, indicating that surface complexes play a significant role in the ability of these thiols to reduce iron. Taken together, these results demonstrate the importance of considering the molecular reaction mechanism at the iron oxide surface when investigating the potential for thiols to act as electron shuttles during dissimilatory iron reduction in natural environments.
Topology optimization of a gas-turbine engine part
NASA Astrophysics Data System (ADS)
Faskhutdinov, R. N.; Dubrovskaya, A. S.; Dongauzer, K. A.; Maksimov, P. V.; Trufanov, N. A.
2017-02-01
One of the key goals of aerospace industry is a reduction of the gas turbine engine weight. The solution of this task consists in the design of gas turbine engine components with reduced weight retaining their functional capabilities. Topology optimization of the part geometry leads to an efficient weight reduction. A complex geometry can be achieved in a single operation with the Selective Laser Melting technology. It should be noted that the complexity of structural features design does not affect the product cost in this case. Let us consider a step-by-step procedure of topology optimization by an example of a gas turbine engine part.
Approach for Structurally Clearing an Adaptive Compliant Trailing Edge Flap for Flight
NASA Technical Reports Server (NTRS)
Miller, Eric J.; Lokos, William A.; Cruz, Josue; Crampton, Glen; Stephens, Craig A.; Kota, Sridhar; Ervin, Gregory; Flick, Pete
2015-01-01
The Adaptive Compliant Trailing Edge (ACTE) flap was flown on the NASA Gulfstream GIII test bed at the NASA Armstrong Flight Research Center. This smoothly curving flap replaced the existing Fowler flaps creating a seamless control surface. This compliant structure, developed by FlexSys Inc. in partnership with Air Force Research Laboratory, supported NASA objectives for airframe structural noise reduction, aerodynamic efficiency, and wing weight reduction through gust load alleviation. A thorough structures airworthiness approach was developed to move this project safely to flight.
Low-frequency noise reduction of lightweight airframe structures
NASA Technical Reports Server (NTRS)
Getline, G. L.
1976-01-01
The results of an experimental study to determine the noise attenuation characteristics of aircraft type fuselage structural panels were presented. Of particular interest was noise attenuation at low frequencies, below the fundamental resonances of the panels. All panels were flightweight structures for transport type aircraft in the 34,050 to 45,400 kg (75,000 to 100,000 pounds) gross weight range. Test data include the results of vibration and acoustic transmission loss tests on seven types of isotropic and orthotropically stiffened, flat and curved panels. The results show that stiffness controlled acoustically integrated structures can provide very high noise reductions at low frequencies without significantly affecting their high frequency noise reduction capabilities.
Preliminary design optimization of joined-wing aircraft
NASA Technical Reports Server (NTRS)
Gallman, John W.; Kroo, Ilan M.; Smith, Stephen C.
1990-01-01
The joined wing is an innovative aircraft configuration that has a its tail connected to the wing forming a diamond shape in both top and plan view. This geometric arrangement utilizes the tail for both pitch control and as a structural support for the wing. Several researchers have studied this configuration and predicted significant reductions in trimmed drag or structural weight when compared with a conventional T-tail configuration. Kroo et al. compared the cruise drag of joined wings with conventional designs of the same lifting-surface area and structural weight. This study showed an 11 percent reduction in cruise drag for the lifting system of a joined wing. Although this reduction in cruise drag is significant, a complete design study is needed before any economic savings can be claimed for a joined-wing transport. Mission constraints, such as runway length, could increase the wing area and eliminate potential drag savings. Since other design codes do not accurately represent the interaction between structures and aerodynamics for joined wings, we developed a new design code for this study. The aerodynamic and structural analyses in this study are significantly more sophisticated than those used in most conventional design codes. This sophistication was needed to predict the aerodynamic interference between the wing and tail and the stresses in the truss-like structure. This paper describes these analysis methods, discusses some problems encountered when applying the numerical optimizer NPSOL, and compares optimum joined wings with conventional aircraft on the basis of cruise drag, lifting surface weight, and direct operating cost (DOC).
NASA Astrophysics Data System (ADS)
Arjunan, A.; Wang, C. J.; Yahiaoui, K.; Mynors, D. J.; Morgan, T.; Nguyen, V. B.; English, M.
2014-11-01
Building standards incorporating quantitative acoustical criteria to ensure adequate sound insulation are now being implemented. Engineers are making great efforts to design acoustically efficient double-wall structures. Accordingly, efficient simulation models to predict the acoustic insulation of double-leaf wall structures are needed. This paper presents the development of a numerical tool that can predict the frequency dependent sound reduction index R of stud based double-leaf walls at one-third-octave band frequency range. A fully vibro-acoustic 3D model consisting of two rooms partitioned using a double-leaf wall, considering the structure and acoustic fluid coupling incorporating the existing fluid and structural solvers are presented. The validity of the finite element (FE) model is assessed by comparison with experimental test results carried out in a certified laboratory. Accurate representation of the structural damping matrix to effectively predict the R values are studied. The possibilities of minimising the simulation time using a frequency dependent mesh model was also investigated. The FEA model presented in this work is capable of predicting the weighted sound reduction index Rw along with A-weighted pink noise C and A-weighted urban noise Ctr within an error of 1 dB. The model developed can also be used to analyse the acoustically induced frequency dependent geometrical behaviour of the double-leaf wall components to optimise them for best acoustic performance. The FE modelling procedure reported in this paper can be extended to other building components undergoing fluid-structure interaction (FSI) to evaluate their acoustic insulation.
Development of the Main Wing Structure of a High Altitude Long Endurance UAV
NASA Astrophysics Data System (ADS)
Park, Sang Wook; Shin, Jeong Woo; Kim, Tae-Uk
2018-04-01
To enhance the flight endurance of a HALE UAV, the main wing of the UAV should have a high aspect ratio and low structural weight. Since a main wing constructed with the thin walled and slender components needed for low structural weight can suffer catastrophic failure during flight, it is important to develop a light-weight airframe without sacrificing structural integrity. In this paper, the design of the main wing of the HALE UAV was conducted using spars which were composed of a carbon-epoxy cylindrical tube and bulkheads to achieve both the weight reduction and structural integrity. The spars were sized using numerical analysis considering non-linear deformation under bending moment. Static strength testing of the wing was conducted under the most critical load condition. Then, the experimental results obtained for the wing were compared to the analytical result from the non-linear finite-element analysis. It was found that the developed main wing reduced its structural weight without any failure under the ultimate load condition of the static strength testing.
The structure of tracheobronchial mucins from cystic fibrosis and control patients.
Gupta, R; Jentoft, N
1992-02-15
Tracheobronchial mucin samples from control and cystic fibrosis patients were purified by gel filtration chromatography on Sephacryl S-1000 and by density gradient centrifugation. Normal secretions contained high molecular weight (approximately 10(7] mucins, whereas the cystic fibrosis secretions contained relatively small amounts of high molecular weight mucin together with larger quantities of lower molecular weight mucin fragments. These probably represent products of protease digestion. Reducing the disulfide bonds in either the control or cystic fibrosis high molecular weight mucin fractions released subunits of approximately 2000 kDa. Treating these subunits with trypsin released glycopeptides of 300 kDa. Trypsin treatment of unreduced mucin also released fragments of 2000 kDa that could be converted into 300-kDa glycopeptides upon disulfide bond reduction. Thus, protease-susceptible linkages within these mucins must be cross-linked by disulfide bonds so that the full effects of proteolytic degradation of mucins remain cryptic until disulfide bonds are reduced. Since various combinations of protease treatment and disulfide bond reduction release either 2000- or 300-kDa fragments, these fragments must represent important elements of mucin structure. The high molecular weight fractions of cystic fibrosis mucins appear to be indistinguishable from control mucins. Their amino acid compositions are the same, and various combinations of disulfide bond reduction and protease treatment release products of identical size and amino acid composition. Sulfate and carbohydrate compositions did vary considerably from sample to sample, but the limited number of samples tested did not demonstrate a cystic fibrosis-specific pattern. Thus, tracheobronchial mucins from cystic fibrosis and control patients are very similar, and both share the same generalized structure previously determined for salivary, cervical, and intestinal mucins.
Aerostructural analysis and design optimization of composite aircraft
NASA Astrophysics Data System (ADS)
Kennedy, Graeme James
High-performance composite materials exhibit both anisotropic strength and stiffness properties. These anisotropic properties can be used to produce highly-tailored aircraft structures that meet stringent performance requirements, but these properties also present unique challenges for analysis and design. New tools and techniques are developed to address some of these important challenges. A homogenization-based theory for beams is developed to accurately predict the through-thickness stress and strain distribution in thick composite beams. Numerical comparisons demonstrate that the proposed beam theory can be used to obtain highly accurate results in up to three orders of magnitude less computational time than three-dimensional calculations. Due to the large finite-element model requirements for thin composite structures used in aerospace applications, parallel solution methods are explored. A parallel direct Schur factorization method is developed. The parallel scalability of the direct Schur approach is demonstrated for a large finite-element problem with over 5 million unknowns. In order to address manufacturing design requirements, a novel laminate parametrization technique is presented that takes into account the discrete nature of the ply-angle variables, and ply-contiguity constraints. This parametrization technique is demonstrated on a series of structural optimization problems including compliance minimization of a plate, buckling design of a stiffened panel and layup design of a full aircraft wing. The design and analysis of composite structures for aircraft is not a stand-alone problem and cannot be performed without multidisciplinary considerations. A gradient-based aerostructural design optimization framework is presented that partitions the disciplines into distinct process groups. An approximate Newton-Krylov method is shown to be an efficient aerostructural solution algorithm and excellent parallel scalability of the algorithm is demonstrated. An induced drag optimization study is performed to compare the trade-off between wing weight and induced drag for wing tip extensions, raked wing tips and winglets. The results demonstrate that it is possible to achieve a 43% induced drag reduction with no weight penalty, a 28% induced drag reduction with a 10% wing weight reduction, or a 20% wing weight reduction with a 5% induced drag penalty from a baseline wing obtained from a structural mass-minimization problem with fixed aerodynamic loads.
Technology development status at McDonnell Douglas
NASA Technical Reports Server (NTRS)
Rowe, W. T.
1981-01-01
The significant technology items of the Concorde and the conceptual MCD baseline advanced supersonic transport are compared. The four major improvements are in the areas of range performance, structures (materials), aerodynamics, and in community noise. Presentation charts show aerodynamic efficiency; the reoptimized wing; low scale lift/drag ratio; control systems; structural modeling and analysis; weight and cost comparisons for superplasticity diffusion bonded titanium sandwich structures and for aluminum brazed titanium honeycomb structures; operating cost reduction; suppressor nozzles; noise reduction and range; the bicone inlet; a market summary; environmental issues; high priority items; the titanium wing and fuselage test components; and technology validation.
NASA Technical Reports Server (NTRS)
Handschuh, Katherine M.; Miller, Sandi G.; Sinnott, Matthew J.; Kohlman, Lee W.; Roberts, Gary D.; Pereira, J. Michael; Ruggeri, Charles R.
2014-01-01
Application of polymer matrix composite materials for jet engine fan blades is becoming attractive as an alternative to metallic blades; particularly for large engines where significant weight savings are recognized on moving to a composite structure. However, the weight benefit of the composite of is offset by a reduction of aerodynamic efficiency resulting from a necessary increase in blade thickness; relative to the titanium blades. Blade dimensions are largely driven by resistance to damage on bird strike. Further development of the composite material is necessary to allow composite blade designs to approximate the dimensions of a metallic fan blade. The reduction in thickness over the state of the art composite blades is expected to translate into structural weight reduction, improved aerodynamic efficiency, and therefore reduced fuel consumption. This paper presents test article design, subcomponent blade leading edge fabrication, test method development, and initial results from ballistic impact of a gelatin projectile on the leading edge of composite fan blades. The simplified test article geometry was developed to realistically simulate a blade leading edge while decreasing fabrication complexity. Impact data is presented on baseline composite blades and toughened blades; where a considerable improvement to impact resistance was recorded.
NASA Technical Reports Server (NTRS)
Miller, Sandi G.; Handschuh, Katherine; Sinnott, Matthew J.; Kohlman, Lee W.; Roberts, Gary D.; Martin, Richard E.; Ruggeri, Charles R.; Pereira, J. Michael
2015-01-01
Application of polymer matrix composite materials for jet engine fan blades is becoming attractive as an alternative to metallic blades; particularly for large engines where significant weight savings are recognized on moving to a composite structure. However, the weight benefit of the composite is offset by a reduction of aerodynamic efficiency resulting from a necessary increase in blade thickness; relative to the titanium blades. Blade dimensions are largely driven by resistance to damage on bird strike. Further development of the composite material is necessary to allow composite blade designs to approximate the dimensions of a metallic fan blade. The reduction in thickness over the state of the art composite blades is expected to translate into structural weight reduction, improved aerodynamic efficiency, and therefore reduced fuel consumption. This paper presents test article design, subcomponent blade leading edge fabrication, test method development, and initial results from ballistic impact of a gelatin projectile on the leading edge of composite fan blades. The simplified test article geometry was developed to realistically simulate a blade leading edge while decreasing fabrication complexity. Impact data is presented on baseline composite blades and toughened blades; where a considerable improvement to impact resistance was recorded.
An investigation on the use of shredded waste PET bottles as aggregate in lightweight concrete.
Akçaözoğlu, Semiha; Atiş, Cengiz Duran; Akçaözoğlu, Kubilay
2010-02-01
In this work, the utilization of shredded waste Poly-ethylene Terephthalate (PET) bottle granules as a lightweight aggregate in mortar was investigated. Investigation was carried out on two groups of mortar samples, one made with only PET aggregates and, second made with PET and sand aggregates together. Additionally, blast-furnace slag was also used as the replacement of cement on mass basis at the replacement ratio of 50% to reduce the amount of cement used and provide savings. The water-binder (w/b) ratio and PET-binder (PET/b) ratio used in the mixtures were 0.45 and 0.50, respectively. The size of shredded PET granules used in the preparation of mortar mixtures were between 0 and 4 mm. The results of the laboratory study and testing carried out showed that mortar containing only PET aggregate, mortar containing PET and sand aggregate, and mortars modified with slag as cement replacement can be drop into structural lightweight concrete category in terms of unit weight and strength properties. Therefore, it was concluded that there is a potential for the use of shredded waste PET granules as aggregate in the production of structural lightweight concrete. The use of shredded waste PET granules due to its low unit weight reduces the unit weight of concrete which results in a reduction in the death weight of a structural concrete member of a building. Reduction in the death weight of a building will help to reduce the seismic risk of the building since the earthquake forces linearly dependent on the dead-weight. Furthermore, it was also concluded that the use of industrial wastes such as PET granules and blast-furnace slag in concrete provides some advantages, i.e., reduction in the use of natural resources, disposal of wastes, prevention of environmental pollution, and energy saving.
An investigation on the use of shredded waste PET bottles as aggregate in lightweight concrete
DOE Office of Scientific and Technical Information (OSTI.GOV)
Akcaoezoglu, Semiha, E-mail: sakcaozoglu@nigde.edu.t; Atis, Cengiz Duran; Akcaoezoglu, Kubilay
2010-02-15
In this work, the utilization of shredded waste Poly-ethylene Terephthalate (PET) bottle granules as a lightweight aggregate in mortar was investigated. Investigation was carried out on two groups of mortar samples, one made with only PET aggregates and, second made with PET and sand aggregates together. Additionally, blast-furnace slag was also used as the replacement of cement on mass basis at the replacement ratio of 50% to reduce the amount of cement used and provide savings. The water-binder (w/b) ratio and PET-binder (PET/b) ratio used in the mixtures were 0.45 and 0.50, respectively. The size of shredded PET granules usedmore » in the preparation of mortar mixtures were between 0 and 4 mm. The results of the laboratory study and testing carried out showed that mortar containing only PET aggregate, mortar containing PET and sand aggregate, and mortars modified with slag as cement replacement can be drop into structural lightweight concrete category in terms of unit weight and strength properties. Therefore, it was concluded that there is a potential for the use of shredded waste PET granules as aggregate in the production of structural lightweight concrete. The use of shredded waste PET granules due to its low unit weight reduces the unit weight of concrete which results in a reduction in the death weight of a structural concrete member of a building. Reduction in the death weight of a building will help to reduce the seismic risk of the building since the earthquake forces linearly dependant on the dead-weight. Furthermore, it was also concluded that the use of industrial wastes such as PET granules and blast-furnace slag in concrete provides some advantages, i.e., reduction in the use of natural resources, disposal of wastes, prevention of environmental pollution, and energy saving.« less
Application of advanced technologies to small, short-haul aircraft
NASA Technical Reports Server (NTRS)
Andrews, D. G.; Brubaker, P. W.; Bryant, S. L.; Clay, C. W.; Giridharadas, B.; Hamamoto, M.; Kelly, T. J.; Proctor, D. K.; Myron, C. E.; Sullivan, R. L.
1978-01-01
The results of a preliminary design study which investigates the use of selected advanced technologies to achieve low cost design for small (50-passenger), short haul (50 to 1000 mile) transports are reported. The largest single item in the cost of manufacturing an airplane of this type is labor. A careful examination of advanced technology to airframe structure was performed since one of the most labor-intensive parts of the airplane is structures. Also, preliminary investigation of advanced aerodynamics flight controls, ride control and gust load alleviation systems, aircraft systems and turbo-prop propulsion systems was performed. The most beneficial advanced technology examined was bonded aluminum primary structure. The use of this structure in large wing panels and body sections resulted in a greatly reduced number of parts and fasteners and therefore, labor hours. The resultant cost of assembled airplane structure was reduced by 40% and the total airplane manufacturing cost by 16% - a major cost reduction. With further development, test verification and optimization appreciable weight saving is also achievable. Other advanced technology items which showed significant gains are as follows: (1) advanced turboprop-reduced block fuel by 15.30% depending on range; (2) configuration revisions (vee-tail)-empennage cost reduction of 25%; (3) leading-edge flap addition-weight reduction of 2500 pounds.
Modeling, simulation and optimization approaches for design of lightweight car body structures
NASA Astrophysics Data System (ADS)
Kiani, Morteza
Simulation-based design optimization and finite element method are used in this research to investigate weight reduction of car body structures made of metallic and composite materials under different design criteria. Besides crashworthiness in full frontal, offset frontal, and side impact scenarios, vibration frequencies, static stiffness, and joint rigidity are also considered. Energy absorption at the component level is used to study the effectiveness of carbon fiber reinforced polymer (CFRP) composite material with consideration of different failure criteria. A global-local design strategy is introduced and applied to multi-objective optimization of car body structures with CFRP components. Multiple example problems involving the analysis of full-vehicle crash and body-in-white models are used to examine the effect of material substitution and the choice of design criteria on weight reduction. The results of this study show that car body structures that are optimized for crashworthiness alone may not meet the vibration criterion. Moreover, optimized car body structures with CFRP components can be lighter with superior crashworthiness than the baseline and optimized metallic structures.
Evaluation of the impact of noise metrics on tiltrotor aircraft design
NASA Technical Reports Server (NTRS)
Sternfeld, H.; Spencer, R.; Ziegenbein, P.
1995-01-01
A subjective noise evaluation was conducted in which the test participants evaluated the annoyance of simulated sounds representative of future civil tiltrotor aircraft. The subjective responses were correlated with the noise metrics of A-weighted sound pressure level, overall sound pressure level, and perceived level. The results indicated that correlation between subjective response and A-weighted sound pressure level is considerably enhanced by combining it in a multiple regression with overall sound pressure level. As a single metric, perceived level correlated better than A-weighted sound pressure level due to greater emphasis on low frequency noise components. This latter finding was especially true for indoor noise where the mid and high frequency noise components are attenuated by typical building structure. Using the results of the subjective noise evaluation, the impact on tiltrotor aircraft design was also evaluated. While A-weighted sound pressure level can be reduced by reduction in tip speed, an increase in number of rotor blades is required to achieve significant reduction of low frequency noise as measured by overall sound pressure level. Additional research, however, is required to achieve comparable reductions in impulsive noise due to blade-vortex interaction, and also to achieve reduction in broad band noise.
Effects of chronic weight perturbation on energy homeostasis and brain structure in mice
Ravussin, Y.; Gutman, R.; Diano, S.; Shanabrough, M.; Borok, E.; Sarman, B.; Lehmann, A.; LeDuc, C. A.; Rosenbaum, M.; Horvath, T. L.
2011-01-01
Maintenance of reduced body weight in lean and obese human subjects results in the persistent decrease in energy expenditure below what can be accounted for by changes in body mass and composition. Genetic and developmental factors may determine a central nervous system (CNS)-mediated minimum threshold of somatic energy stores below which behavioral and metabolic compensations for weight loss are invoked. A critical question is whether this threshold can be altered by environmental influences and by what mechanisms such alterations might be achieved. We examined the bioenergetic, behavioral, and CNS structural responses to weight reduction of diet-induced obese (DIO) and never-obese (CON) C57BL/6J male mice. We found that weight-reduced (WR) DIO-WR and CON-WR animals showed reductions in energy expenditure, adjusted for body mass and composition, comparable (−10–15%) to those seen in human subjects. The proportion of excitatory synapses on arcuate nucleus proopiomelanocortin neurons was decreased by ∼50% in both DIO-WR and CON-WR mice. These data suggest that prolonged maintenance of an elevated body weight (fat) alters energy homeostatic systems to defend a higher level of body fat. The synaptic changes could provide a neural substrate for the disproportionate decline in energy expenditure in weight-reduced individuals. This response to chronic weight elevation may also occur in humans. The mouse model described here could help to identify the molecular/cellular mechanisms underlying both the defense mechanisms against sustained weight loss and the upward resetting of those mechanisms following sustained weight gain. PMID:21411766
ERIC Educational Resources Information Center
Cox, Tiffany L.; Zunker, Christie; Wingo, Brooks C.; Jefferson, Wendy K.; Ard, Jamy D.
2011-01-01
We qualitatively assessed how life stressors affected African American women's participation in a weight reduction program. A sample of 9 women, who completed a behavioral lifestyle intervention, participated in individual, structured, in-depth interviews. Life stressors, ranging from personal illness to changes in employment status, had varied…
NASA Astrophysics Data System (ADS)
Degenhardt, Richard
2014-06-01
Space industry demands for reduced development and operating costs. Structural weight reduction by exploitation of structural reserves in composite space and aerospace structures contributes to this aim, however, it requires accurate and experimentally validated stability analysis. Currently, the potential of composite light weight structures, which are prone to buckling, is not fully exploited as appropriate guidelines in the field of space applications do not exist. This paper deals with the state-of-the-art advances and challenges related to coupled stability analysis of composite structures which show very complex stability behaviour. Improved design guidelines for composites structures are still under development. This paper gives a short state-of-the-art and presents a proposal for a future design guideline.
A Novel SMA-based Concept for Airfoil Structural Morphing
NASA Astrophysics Data System (ADS)
Barbarino, S.; Pecora, R.; Lecce, L.; Concilio, A.; Ameduri, S.; Calvi, E.
2009-08-01
The adaptive structures concept is of great interest in the aerospace field because of the several benefits which can be accomplished in the fields including noise reduction, load alleviation, weight reduction, etc., at a level in which they can be considered as compulsory in the design of future aircraft. Improvements in terms of the aerodynamic efficiency, aeroelastic behavior, stability, and manoeuvrability performance have already been proved through many international studies in the past. In the family of the Smart Materials, Shape Memory Alloys (SMA) seem to be a suitable solution for many static applications. Their high structural integrability in conjunction with actuation capabilities and a favorable performance per weight ratio, allows the development of original architectures. In this study, a morphing wing trailing edge concept is presented; morphing ability was introduced with the aim of replacing a conventional flap device. A compliant rib structure was designed, based on SMA actuators exhibiting structural potential (bearing external aerodynamic loads). Numerical results, achieved through a FE approach, are presented in terms of trailing edge induced displacement and morphed shape.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Levakhina, Y. M.; Mueller, J.; Buzug, T. M.
Purpose: This paper introduces a nonlinear weighting scheme into the backprojection operation within the simultaneous algebraic reconstruction technique (SART). It is designed for tomosynthesis imaging of objects with high-attenuation features in order to reduce limited angle artifacts. Methods: The algorithm estimates which projections potentially produce artifacts in a voxel. The contribution of those projections into the updating term is reduced. In order to identify those projections automatically, a four-dimensional backprojected space representation is used. Weighting coefficients are calculated based on a dissimilarity measure, evaluated in this space. For each combination of an angular view direction and a voxel position anmore » individual weighting coefficient for the updating term is calculated. Results: The feasibility of the proposed approach is shown based on reconstructions of the following real three-dimensional tomosynthesis datasets: a mammography quality phantom, an apple with metal needles, a dried finger bone in water, and a human hand. Datasets have been acquired with a Siemens Mammomat Inspiration tomosynthesis device and reconstructed using SART with and without suggested weighting. Out-of-focus artifacts are described using line profiles and measured using standard deviation (STD) in the plane and below the plane which contains artifact-causing features. Artifacts distribution in axial direction is measured using an artifact spread function (ASF). The volumes reconstructed with the weighting scheme demonstrate the reduction of out-of-focus artifacts, lower STD (meaning reduction of artifacts), and narrower ASF compared to nonweighted SART reconstruction. It is achieved successfully for different kinds of structures: point-like structures such as phantom features, long structures such as metal needles, and fine structures such as trabecular bone structures. Conclusions: Results indicate the feasibility of the proposed algorithm to reduce typical tomosynthesis artifacts produced by high-attenuation features. The proposed algorithm assigns weighting coefficients automatically and no segmentation or tissue-classification steps are required. The algorithm can be included into various iterative reconstruction algorithms with an additive updating strategy. It can also be extended to computed tomography case with the complete set of angular data.« less
Singh, Mandeep; Lee, Jaehoon; Gupta, Neil; Gaddam, Srinivas; Smith, Bryan K.; Wani, Sachin B.; Sullivan, Debra K.; Rastogi, Amit; Bansal, Ajay; Donnelly, Joseph E.; Sharma, Prateek
2013-01-01
Objective Weight gain is an important risk factor for gastroesophageal reflux disease (GERD); however, whether weight loss can lead to resolution of GERD symptoms is not clear. Our aim was to measure the impact of weight loss on GERD symptoms. Design and Methods In a prospective cohort study at a tertiary referral center, overweight/obese subjects (BMI 25-39.9 kg/m2) were enrolled in a structured weight loss program. Weight loss strategies included dietary modifications, increased physical activity and behavioral changes. At baseline and at 6 months, BMI and waist circumference were measured and all participants completed a validated reflux disease questionnaire. Results A total of 332 adult subjects, mean age 46 years and 66% women were prospectively enrolled. At baseline, the mean body weight, BMI, and waist circumference were 101 (±18) kg, 35 (±5) kg/m2 and 103 (±13) cm. At 6 months, majority of the subjects (97%) lost weight (average weight loss: 13 ± 7.7 kg) and as compared with baseline, there was a significant decrease in the overall prevalence of GERD (15 vs. 37%; P < 0.01) and the mean GERD symptom score (1.8 vs. 5.5; P < 0.01). Overall, 81% of the subjects had reduction in GERD symptom scores; 65% had complete resolution and 15% had partial resolution of reflux symptoms. There was a significant correlation between % body weight loss and reduction in GERD symptom scores (r = 0.17, P < 0.05). Conclusions In conclusion, the overall prevalence of GERD symptoms is high (37%) in overweight and obese subjects. A structured weight loss program can lead to complete resolution of GERD symptoms in the majority of these subjects. PMID:23532991
Nandigam, Ravi K; Kim, Sangtae; Singh, Juswinder; Chuaqui, Claudio
2009-05-01
The desire to exploit structural information to aid structure based design and virtual screening led to the development of the interaction fingerprint for analyzing, mining, and filtering the binding patterns underlying the complex 3D data. In this paper we introduce a new approach, weighted SIFt (or w-SIFt), extending the concept of SIFt to capture the relative importance of different binding interactions. The methodology presented here for determining the weights in w-SIFt involves utilizing a dimensionality reduction technique for eliminating linear redundancies in the data followed by a stochastic optimization. We find that the relative weights of the fingerprint bits provide insight into what interactions are critical in determining inhibitor potency. Moreover, the weighted interaction fingerprint can serve as an interpretable position dependent scoring function for ligand protein interactions.
Global cost and weight evaluation of fuselage keel design concepts
NASA Technical Reports Server (NTRS)
Flynn, B. W.; Morris, M. R.; Metschan, S. L.; Swanson, G. D.; Smith, P. J.; Griess, K. H.; Schramm, M. R.; Humphrey, R. J.
1993-01-01
The Boeing program entitled Advanced Technology Composite Aircraft Structure (ATCAS) is focused on the application of affordable composite technology to pressurized fuselage structure of future aircraft. As part of this effort, a design study was conducted on the keel section of the aft fuselage. A design build team (DBT) approach was used to identify and evaluate several design concepts which incorporated different material systems, fabrication processes, structural configurations, and subassembly details. The design concepts were developed in sufficient detail to accurately assess their potential for cost and weight savings as compared with a metal baseline representing current wide body technology. The cost and weight results, along with an appraisal of performance and producibility risks, are used to identify a globally optimized keel design; one which offers the most promising cost and weight advantages over metal construction. Lastly, an assessment is given of the potential for further cost and weight reductions of the selected keel design during local optimization.
Neff, Karl J; Elliott, Jessie A; Corteville, Caroline; Abegg, Kathrin; Boza, Camilo; Lutz, Thomas A; Docherty, Neil G; le Roux, Carel W
2017-01-01
Reductions in urinary protein excretion after Roux-en-Y gastric bypass (RYGB) surgery in patients with diabetic kidney disease have been reported in multiple studies. To determine the weight loss dependence of the effect of RYGB on urinary protein excretion by comparing renal outcomes in Zucker diabetic fatty rats undergoing either gastric bypass surgery or a sham operation with or without weight matching. University laboratories. Zucker diabetic fatty rats underwent surgery at 18 weeks of age. A subgroup of sham operated rats were weight matched to RYGB operated rats by restricting food intake. Urinary protein excretion was assessed at baseline and at postoperative weeks 4 and 12. Renal histology and macrophage-associated inflammation were assessed at postoperative week 12. Progressive urinary protein excretion was attenuated by both RYGB and diet-induced weight loss, albeit to a lesser extent by the latter. Both weight loss interventions produced equivalent reductions in glomerulomegaly, glomerulosclerosis, and evidence of renal macrophage infiltration. Weight loss per se improves renal structure and attenuates renal inflammatory responses in an experimental animal model of diabetic kidney disease. Better glycemic control post-RYGB may in part explain the greater reductions in urinary protein excretion after gastric bypass surgery. Copyright © 2017 American Society for Bariatric Surgery. Published by Elsevier Inc. All rights reserved.
Structural Design and Analysis of Un-pressurized Cargo Delivery Vehicle
NASA Technical Reports Server (NTRS)
Martinovic, Zoran N.
2007-01-01
As part of the Exploration Systems Architecture Study, NASA has defined a family of vehicles to support lunar exploration and International Space Station (ISS) re-supply missions after the Shuttle s retirement. The Un-pressurized Cargo Delivery Vehicle (UCDV) has been envisioned to be an expendable logistics delivery vehicle that would be used to deliver external cargo to the ISS. It would be launched on the Crew Launch Vehicle and would replace the Crew Exploration Vehicle. The estimated cargo would be the weight of external logistics to the ISS. Determining the minimum weight design of the UCDV during conceptual design is the major issue addressed in this paper. This task was accomplished using a procedure for rapid weight estimation that was based on Finite Element Analysis and sizing of the vehicle by the use of commercially available codes. Three design concepts were analyzed and their respective weights were compared. The analytical structural weight was increased by a factor to account for structural elements that were not modeled. Significant reduction in weight of a composite design over metallic was achieved for similar panel concepts.
The Development of the Zeppelin Dirigible for Long Distance Transportation
NASA Technical Reports Server (NTRS)
Ehrle, A.
1980-01-01
Changes in the design and construction of German airships for regular transoceanic passenger transportation during the 1916 to 1938 period are described. Technical problems related to structural weight, fuel reduction, and passenger comfort are considered.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Sethuraman, Latha; Fingersh, Lee J; Dykes, Katherine L
As wind turbine blade diameters and tower height increase to capture more energy in the wind, higher structural loads results in more structural support material increasing the cost of scaling. Weight reductions in the generator transfer to overall cost savings of the system. Additive manufacturing facilitates a design-for-functionality approach, thereby removing traditional manufacturing constraints and labor costs. The most feasible additive manufacturing technology identified for large, direct-drive generators in this study is powder-binder jetting of a sand cast mold. A parametric finite element analysis optimization study is performed, optimizing for mass and deformation. Also, topology optimization is employed for eachmore » parameter-optimized design.The optimized U-beam spoked web design results in a 24 percent reduction in structural mass of the rotor and 60 percent reduction in radial deflection.« less
Applying a Stitched, Rod-Stiffened Concept to Heavily Loaded Structure
NASA Technical Reports Server (NTRS)
Jegley, Dawn C.
2013-01-01
NASA and the Boeing Company have worked to develop new low-cost, light-weight composite structures for aircraft. A stitched carbon-epoxy material system was developed to reduce the weight and cost of transport aircraft wing structure, first in the NASA Advanced Composites Technology (ACT) program in the 1990's and now in the Environmentally Responsible Aviation (ERA) Project. By stitching through the thickness of a dry carbon fiber material prior to cure, the labor associated with panel fabrication and assembly can be significantly reduced and the need for mechanical fasteners is almost eliminated. Stitching provides the benefit of reducing or eliminating delaminations, including those between stiffener flanges and skin. Stitching also reduces part count, and therefore, cost of the structure. The stitched panel concept used in the ACT program in the 1990's used simple blade-stiffeners as stringers, caps and clips. Today, the Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) concept is being developed for application to advanced vehicle configurations. PRSEUS provides additional weight savings through the use of a stiffener with a thin web and a unidirectional carbon rod at the top of the web which provides structurally efficient stiffening. A comparison between the blade-stiffened structure and PRSEUS is presented focusing on highly loaded structure and demonstrating improved weight reduction.
Study on utilization of advanced composites in fuselage structures of large transports
NASA Technical Reports Server (NTRS)
Johnson, R. W.; Thomson, L. W.; Wilson, R. D.
1985-01-01
The potential for utilizing advanced composites in fuselage structures of large transports was assessed. Six fuselage design concepts were selected and evaluated in terms of structural performance, weight, and manufacturing development and costs. Two concepts were selected that merit further consideration for composite fuselage application. These concepts are: (1) a full depth honeycomb design with no stringers, and (2) an I section stringer stiffened laminate skin design. Weight reductions due to applying composites to the fuselages of commercial and military transports were calculated. The benefits of applying composites to a fleet of military transports were determined. Significant technology issues pertinent to composite fuselage structures were identified and evaluated. Program plans for resolving the technology issues were developed.
NASA Technical Reports Server (NTRS)
1975-01-01
Structural requirements for future space missions were defined in relation to technology needs and payloads. Specific areas examined include: large area space structures (antennas, solar array structures, and platforms); a long, slender structure or boom used to support large objects from the shuttle or hold two bodies apart in space; and advanced composite structures for cost effective weight reductions. Other topics discussed include: minimum gage concepts, high temperature components, load and response determination and control, and reliability and life prediction.
Cryogenic Tank Structure Sizing With Structural Optimization Method
NASA Technical Reports Server (NTRS)
Wang, J. T.; Johnson, T. F.; Sleight, D. W.; Saether, E.
2001-01-01
Structural optimization methods in MSC /NASTRAN are used to size substructures and to reduce the weight of a composite sandwich cryogenic tank for future launch vehicles. Because the feasible design space of this problem is non-convex, many local minima are found. This non-convex problem is investigated in detail by conducting a series of analyses along a design line connecting two feasible designs. Strain constraint violations occur for some design points along the design line. Since MSC/NASTRAN uses gradient-based optimization procedures. it does not guarantee that the lowest weight design can be found. In this study, a simple procedure is introduced to create a new starting point based on design variable values from previous optimization analyses. Optimization analysis using this new starting point can produce a lower weight design. Detailed inputs for setting up the MSC/NASTRAN optimization analysis and final tank design results are presented in this paper. Approaches for obtaining further weight reductions are also discussed.
Mechanical Characterization of Baslat Based Natural Hybrid Composites for Aerospace Applications
NASA Astrophysics Data System (ADS)
Alexander, J.; Elphej Churchill, S. J.
2017-05-01
Advanced composites have attracted aircraft designers due to its high strength to weight ratio, high stiffness to weight ratio, tailoring properties, hybridization of opposites etc. Moreover the cost reduction is also another important requirement of structural components. Basalt fibers are new entry in structural field which has excellent properties more or less equivalent to GFRP composites. Using these basalt fibres, new hybrid composites were developed by combining basalt fibres with natural fibres. The mechanical and thermal properties were determined and compared with BFRP and GFRP composites. Results proved that hybrid composites have some good qualities.
Garvin, Jane T; Hardy, Dale; Xu, Hongyan
2016-04-21
Obesity management guidelines specify initial goals for participation and weight reduction for the first 6 months of a weight-reduction intervention, but guidelines do not specify when to assess early response and make adjustments. We aimed to determine whether very early or early weight reduction in the weight-reduction program MOVE! predicted later participation or achievement of weight-reduction goals. Using clinical data from 375 MOVE! participants enrolled from July 2008 through May 2010, we examined program participation and weight reduction. Very early response was defined as achieving a weight reduction of 0.5% or more at week 2, and early response was defined as achieving weight reduction of 1.0% or more at week 4. Success, or achievement of weight-reduction goal, at 6 months, 1 year, and 2 years was defined as a weight reduction of 5% or more. Participation was assessed according to the number of sessions attended within the first 6 months of program enrollment; attendance of 14 or more sessions was classified as high-intensity participation. Very early responders were more than 5 times as likely (odds ratio [OR] = 5.46; 95% confidence interval [CI], 1.69-17.71; P = .005) and early responders were more than 10 times as likely (OR = 10.76; 95% CI, 2.64-43.80; P = .001) to achieve the 6-month weight-reduction goal as participants who were not very early responders or early responders, respectively. Early responders were almost 7 times as likely to achieve the 1-year weight-reduction goal (OR = 6.96; 95% CI, 1.85-26.13; P = .004). Neither very early nor early response predicted participation, high-intensity participation, or success at 2 years. This research supports the predictive value of very early response and early response to MOVE! on weight-reduction success at 6 months; early response also predicted 1-year success, suggesting that the 2-week point may be an ideal time to assess initial response and make intervention adjustments.
Hardy, Dale; Xu, Hongyan
2016-01-01
Introduction Obesity management guidelines specify initial goals for participation and weight reduction for the first 6 months of a weight-reduction intervention, but guidelines do not specify when to assess early response and make adjustments. We aimed to determine whether very early or early weight reduction in the weight-reduction program MOVE! predicted later participation or achievement of weight-reduction goals. Methods Using clinical data from 375 MOVE! participants enrolled from July 2008 through May 2010, we examined program participation and weight reduction. Very early response was defined as achieving a weight reduction of 0.5% or more at week 2, and early response was defined as achieving weight reduction of 1.0% or more at week 4. Success, or achievement of weight-reduction goal, at 6 months, 1 year, and 2 years was defined as a weight reduction of 5% or more. Participation was assessed according to the number of sessions attended within the first 6 months of program enrollment; attendance of 14 or more sessions was classified as high-intensity participation. Results Very early responders were more than 5 times as likely (odds ratio [OR] = 5.46; 95% confidence interval [CI], 1.69–17.71; P = .005) and early responders were more than 10 times as likely (OR = 10.76; 95% CI, 2.64–43.80; P = .001) to achieve the 6-month weight-reduction goal as participants who were not very early responders or early responders, respectively. Early responders were almost 7 times as likely to achieve the 1-year weight-reduction goal (OR = 6.96; 95% CI, 1.85–26.13; P = .004). Neither very early nor early response predicted participation, high-intensity participation, or success at 2 years. Conclusion This research supports the predictive value of very early response and early response to MOVE! on weight-reduction success at 6 months; early response also predicted 1-year success, suggesting that the 2-week point may be an ideal time to assess initial response and make intervention adjustments. PMID:27103265
Design and Manufacturing of Composite Tower Structure for Wind Turbine Equipment
NASA Astrophysics Data System (ADS)
Park, Hyunbum
2018-02-01
This study proposes the composite tower design process for large wind turbine equipment. In this work, structural design of tower and analysis using finite element method was performed. After structural design, prototype blade manufacturing and test was performed. The used material is a glass fiber and epoxy resin composite. And also, sand was used in the middle part. The optimized structural design and analysis was performed. The parameter for optimized structural design is weight reduction and safety of structure. Finally, structure of tower will be confirmed by structural test.
Gunardi, A J; Brennan, S L; Wang, Y; Cicuttini, F M; Pasco, J A; Kotowicz, M A; Nicholson, G C; Wluka, A E
2013-12-01
Osteoarthritis (OA) most commonly affects the patellofemoral compartment of the knee, and is a major cause of pain and disability. Structural changes that evolve prior to the onset of symptoms can be visualised using magnetic resonance imaging (MRI). There is little known information about the role of adiposity on the early structural changes in the patella cartilage in younger, asymptomatic adult females. One hundred and sixty asymptomatic women (20-49 years) participating in the Geelong Osteoporosis Study underwent knee MRI (2006-8). Weight and body mass index (BMI) were measured 10 years prior (1994-7, baseline) and at the time of MRI (current), with change over the period calculated (current-baseline). Relationships between measures of adiposity and patella cartilage volume and defects were examined. After adjustment for age and patella bone volume, there was a reduction of 13 ml (95% confidence interval (95% CI), -25.7, -0.55) in patella cartilage volume for every 1 unit increase in current BMI, and a reduction of 27 ml (95% CI -52.6, -1.5) per BMI unit increase over 10 years (P=0.04 for both). No significant association was observed between baseline BMI and patella cartilage volume (P=0.16). Increased baseline and current weight and BMI were associated with increased prevalence of patella cartilage defects (all P<0.001). Adiposity and weight gain during midlife are associated with detrimental structural change at the patella in young to middle-aged healthy non-osteoarthritic women. Maintaining a healthy weight and avoiding weight gain in younger asymptomatic women may be important in the prevention of patellofemoral OA.
Approach for Structurally Clearing an Adaptive Compliant Trailing Edge Flap for Flight
NASA Technical Reports Server (NTRS)
Miller, Eric J.; Lokos, William A.; Cruz, Josue; Crampton, Glen; Stephens, Craig A.; Kota, Sridhar; Ervin, Gregory; Flick, Pete
2015-01-01
The Adaptive Compliant Trailing Edge (ACTE) flap was flown on the National Aeronautics and Space Administration (NASA) Gulfstream GIII testbed at the NASA Armstrong Flight Research Center. This smoothly curving flap replaced the existing Fowler flaps creating a seamless control surface. This compliant structure, developed by FlexSys Inc. in partnership with the Air Force Research Laboratory, supported NASA objectives for airframe structural noise reduction, aerodynamic efficiency, and wing weight reduction through gust load alleviation. A thorough structures airworthiness approach was developed to move this project safely to flight. A combination of industry and NASA standard practice require various structural analyses, ground testing, and health monitoring techniques for showing an airworthy structure. This paper provides an overview of compliant structures design, the structural ground testing leading up to flight, and the flight envelope expansion and monitoring strategy. Flight data will be presented, and lessons learned along the way will be highlighted.
1991-05-31
Soluble Polymers: Synthesis, Solution Properties, and Applications, ACS Symposium Series 467, Chapter 22, page 338 (1991). "Molecular- Weight -Distribution...Mississippi 39406-0076 at room temperature to remove low molecular weight polymers and excess KOH. The final products were obtained by freeze-drying...polyelectrolytes due to the presence of the were conducted on a Contraves LS 30 low shear rheometer at a shear long hydrophobic side chains in the polymer
NASA Technical Reports Server (NTRS)
Gray, D. E.; Dugan, J. F.
1975-01-01
This paper reports on the exploratory investigation and initial findings of the study of future turbofan concepts to conserve fuel. To date, these studies have indicated a potential reduction in cruise thrust specific fuel consumption in 1990 turbofans of approximately 15% relative to present day new engines through advances in internal aerodynamics, structure-mechanics, and materials. Advanced materials also offer the potential for fuel savings through engine weight reduction. Further studies are required to balance fuel consumption reduction with sound airlines operational economics.
Stability analysis of Caisson Cofferdam Based on Strength Reduction Method
NASA Astrophysics Data System (ADS)
Xu, B. B.; Zhang, N. S.
2018-05-01
The working mechanism of the caisson cofferdam depends on the self-weight of the structure and internal filling to ensure its skid resistance and overturn resistance stability. Using the strength reduction method, the safety factor of the caisson cofferdam can be obtained. The potential slide surface can be searched automatically without constraining the range of the arc center. According to the results, the slippage surface goes through the bottom of the caisson. Based on the judgement criterion of the strength reduction method, the final safety factor is about 1.65.
NASA's Quiet Aircraft Technology Project
NASA Technical Reports Server (NTRS)
Whitfield, Charlotte E.
2004-01-01
NASA's Quiet Aircraft Technology Project is developing physics-based understanding, models and concepts to discover and realize technology that will, when implemented, achieve the goals of a reduction of one-half in perceived community noise (relative to 1997) by 2007 and a further one-half in the far term. Noise sources generated by both the engine and the airframe are considered, and the effects of engine/airframe integration are accounted for through the propulsion airframe aeroacoustics element. Assessments of the contribution of individual source noise reductions to the reduction in community noise are developed to guide the work and the development of new tools for evaluation of unconventional aircraft is underway. Life in the real world is taken into account with the development of more accurate airport noise models and flight guidance methodology, and in addition, technology is being developed that will further reduce interior noise at current weight levels or enable the use of lighter-weight structures at current noise levels.
Structures and materials technology issues for reusable launch vehicles
NASA Technical Reports Server (NTRS)
Dixon, S. C.; Tenney, D. R.; Rummler, D. R.; Wieting, A. R.; Bader, R. M.
1985-01-01
Projected space missions for both civil and defense needs require significant improvements in structures and materials technology for reusable launch vehicles: reductions in structural weight compared to the Space Shuttle Orbiter of up to 25% or more, a possible factor of 5 or more increase in mission life, increases in maximum use temperature of the external surface, reusable containment of cryogenic hydrogen and oxygen, significant reductions in operational costs, and possibly less lead time between technology readiness and initial operational capability. In addition, there is increasing interest in hypersonic airbreathing propulsion for launch and transmospheric vehicles, and such systems require regeneratively cooled structure. The technology issues are addressed, giving brief assessments of the state-of-the-art and proposed activities to meet the technology requirements in a timely manner.
Hemetek, U; Ernert, A; Wiegand, S; Bau, A-M
2015-11-01
The alarming increase in the prevalence of childhood obesity is recognised as a major public health concern. Currently, structured multi-modal therapy programmes present the gold standard of therapy strategies for obese children and adolescents. However, effects of these treatments are still a matter of discussion. Failure to isolate and understand the external and internal factors contributing to successful, long-term weight reduction may well be contributing to the ineffectiveness of current treatment interventions. A qualitative approach was chosen in order to identify subjectively perceived resources and barriers to weight maintenance after previous weight reduction. The research question focused on how these resources and barriers affect success of participants. Additionally the question arose as to how and to what extent parents should and could be involved in the therapy process. The results can deliver important starting points for the development of therapy programmes and future research. 7 participants of a weight reduction and maintenance programme and 7 of their parents were interviewed on their personal experiences during and after the treatment. The interviews were analysed based on the qualitative content analysis. Continuous motivation, especially after the initial weight reduction phase, was identified as the strongest predictor of successful weight maintenance. Successful weight maintainers generally showed characteristics of higher self-efficacy, internal motivation concerning physical activity and flexible self-control concerning food intake. Unsuccessful weight gainers stated a lack of motivation concerning physical activity and lost control over their eating habits. Concerning the role of parents in the therapy process, the results show that higher parental involvement does not predict greater success. The general relationship between parents and their children seems to be more significant, especially concerning the issues of responsibility. It is disputable to what extent the post treatment intervention contributed to the development of intrinsic motivation. More attention should be paid to the age (children or adolescents) of participants of therapy programmes, especially concerning the involvement of parents. It is assumed that general aspects of education should be discussed with parents. © Georg Thieme Verlag KG Stuttgart · New York.
Olefsky, Jerrold; Reaven, Gerald M.; Farquhar, John W.
1974-01-01
Considerable controversy exists over the purported role of obesity in causing hyperglycemia, hyperlipemia, hyperinsulinemia, and insulin resistance; and the potential beneficial effects of weight reduction remain incompletely defined. Hypertriglyceridemia is one of the metabolic abnormalities proposed to accompany obesity, and in order to help explain the mechanisms leading to this abnormality we have proposed the following sequential hypothesis: insulin resistance → hyperinsulinemia → accelerated hepatic triglyceride(TG) production → elevated plasma TG concentrations. To test this hypothesis and to gain insight into both the possible role of obesity in causing the above metabolic abnormalities and the potential benefit of weight reduction we studied the effects of weight loss on various aspects of carbohydrate and lipid metabolism in a group of 36 normal and hyperlipoproteinemic subjects. Only weak to absent correlations (r = 0.03 — 0.46) were noted between obesity and the metabolic variables measured. This points out that in our study group obesity cannot be the sole, or even the major, cause of these abnormalities in the first place. Further, we have observed marked decreases after weight reduction in fasting plasma TG (mean value: pre-weight reduction, 319 mg/100 ml; post-weight reduction, 180 mg/100 ml) and cholesterol (mean values: pre-weight reduction, 282 mg/100 ml; post-weight reduction, 223 mg/100 ml) levels, with a direct relationship between the magnitude of the fall in plasma lipid values and the height of the initial plasma TG level. We have also noted significant decreases after weight reduction in the insulin and glucose responses during the oral glucose tolerance test (37% decrease and 12% decrease, respectively). Insulin and glucose responses to liquid food before and after weight reduction were also measured and the overall post-weight reduction decrease in insulin response was 48% while the glucose response was relatively unchanged. In a subgroup of patients we studied both the degree of cellular insulin resistance and the rate of hepatic very low density (VLDL) TG production before and after weight reduction. These subjects demonstrated significant decreases after weight reduction in both degree of insulin resistance (33% decrease) and VLDL-TG production rates (40% decrease). Thus, weight reduction has lowered each of the antecedent variables (insulin resistance, hyperinsulinemia, and VLDL-TG production) that according to the above hypothesis lead to hypertriglyceridemia, and we believe the overall scheme is greatly strengthened. Furthermore, the consistent decreases in plasma TG and cholesterol levels seen in all subjects lead us to conclude that weight reduction is an important therapeutic modality for patients with endogenous hypertriglyceridemia. Images PMID:4357617
Hybrid-Wing-Body Vehicle Composite Fuselage Analysis and Case Study
NASA Technical Reports Server (NTRS)
Mukhopadhyay, Vivek
2014-01-01
Recent progress in the structural analysis of a Hybrid Wing-Body (HWB) fuselage concept is presented with the objective of structural weight reduction under a set of critical design loads. This pressurized efficient HWB fuselage design is presently being investigated by the NASA Environmentally Responsible Aviation (ERA) project in collaboration with the Boeing Company, Huntington Beach. The Pultruded Rod-Stiffened Efficient Unitized Structure (PRSEUS) composite concept, developed at the Boeing Company, is approximately modeled for an analytical study and finite element analysis. Stiffened plate linear theories are employed for a parametric case study. Maximum deflection and stress levels are obtained with appropriate assumptions for a set of feasible stiffened panel configurations. An analytical parametric case study is presented to examine the effects of discrete stiffener spacing and skin thickness on structural weight, deflection and stress. A finite-element model (FEM) of an integrated fuselage section with bulkhead is developed for an independent assessment. Stress analysis and scenario based case studies are conducted for design improvement. The FEM model specific weight of the improved fuselage concept is computed and compared to previous studies, in order to assess the relative weight/strength advantages of this advanced composite airframe technology
AST Composite Wing Program: Executive Summary
NASA Technical Reports Server (NTRS)
Karal, Michael
2001-01-01
The Boeing Company demonstrated the application of stitched/resin infused (S/RFI) composite materials on commercial transport aircraft primary wing structures under the Advanced Subsonic technology (AST) Composite Wing contract. This report describes a weight trade study utilizing a wing torque box design applicable to a 220-passenger commercial aircraft and was used to verify the weight savings a S/RFI structure would offer compared to an identical aluminum wing box design. This trade study was performed in the AST Composite Wing program, and the overall weight savings are reported. Previous program work involved the design of a S/RFI-base-line wing box structural test component and its associated testing hardware. This detail structural design effort which is known as the "semi-span" in this report, was completed under a previous NASA contract. The full-scale wing design was based on a configuration for a MD-90-40X airplane, and the objective of this structural test component was to demonstrate the maturity of the S/RFI technology through the evaluation of a full-scale wing box/fuselage section structural test. However, scope reductions of the AST Composite Wing Program pre-vented the fabrication and evaluation of this wing box structure. Results obtained from the weight trade study, the full-scale test component design effort, fabrication, design development testing, and full-scale testing of the semi-span wing box are reported.
Numerical investigation of tube hyroforming of TWT using Corner Fill Test
NASA Astrophysics Data System (ADS)
Zribi, Temim; Khalfallah, Ali
2018-05-01
Tube hydroforming presents a very good alternative to conventional forming processes for obtaining good quality mechanical parts used in several industrial fields, such as the automotive and aerospace sectors. Research in the field of tube hydroforming is aimed at improving the formability, stiffness and weight reduction of manufactured parts using this process. In recent years, a new method of hydroforming appears; it consists of deforming parts made from welded tubes and having different thicknesses. This technique which contributes to the weight reduction of the hydroformed tubes is a good alternative to the conventional tube hydroforming. This technique makes it possible to build rigid and light structures with a reduced cost. However, it is possible to improve the weight reduction by using dissimilar tailor welded tubes (TWT). This paper is a first attempt to analyze by numerical simulation the behavior of TWT hydroformed in square cross section dies, commonly called (Corner Fill Test). Considered tubes are composed of two materials assembled by butt welding. The present analysis will focus on the effect of loading paths on the formability of the structure by determining the change in thickness in several sections of the part. A comparison between the results obtained by hydroforming the butt joint of tubes made of dissimilar materials and those obtained using single-material tube is achieved. Numerical calculations show that the bi-material welded tube has better thinning resistance and a more even thickness distribution in the circumferential directions when compared to the single-material tube.
Design concepts for a composite door frame system for general automotive applications
NASA Technical Reports Server (NTRS)
Tauber, J. A.
1976-01-01
Conceptual design, manufacturing process, and costs are explored to determine the feasibility of replacing present steel parts in automotive door structures with various composite materials. The problems of conforming to present anti-intrusion specifications with advanced materials are examined and discussed. Modest weight reductions, at competitive costs, were identified for the utilization of specific composite materials in automotive door structures.
Developmental exposure to hypothyroid-inducing agents leads to reductions in body weight, alterations in hippocampal structure, and impaired performance on a variety of behavioral learning tasks. Electrophysiological properties of the hippocampus in hypothyroid animals, however...
Use of MAGSAT anomaly data for crustal structure and mineral resources in the US Midcontinent
NASA Technical Reports Server (NTRS)
Carmichael, R. S. (Principal Investigator)
1981-01-01
The analysis and preliminary interpretation of investigator-B MAGSAT data are addressed. The data processing included: (1) removal of spurious data points; (2) statistical smoothing along individual data tracks, to reduce the effect of geomagnetic transient disturbances; (3) comparison of data profiles spatially coincident in track location but acquired at different times; (4) reduction of data by weighted averaging to a grid with 1 deg xl deg latitude/longitude spacing, and with elevations interpolated and weighted to a common datum of 400 km; (5) wavelength filtering; and (6) reduction of the anomaly map to the magnetic pole. Agreement was found between a magnitude data anomaly map and a reduce-to-the-pole map supporting the general assumption that, on a large scale (long wavelength), it is induced crustal magnetization which is responsible for major anamalies. Anomalous features are identified and explanations are suggested with regard to crustal structure, petrologic characteristics, and Curie temperature isotherms.
Smith, Daniel L.; Robertson, Henry; Desmond, Renee; Nagy, Tim R.; Allison, David B.
2010-01-01
Objective The health and longevity effects of body weight reduction resulting from exercise and caloric restriction in rodents are well known, but less is known about whether similar effects occur with weight reduction from the use of a pharmaceutical agent such as sibutramine, a serotonin-norepinephrine reuptake inhibitor. Results & Conclusion Using data from a two-year toxicology study of sibutramine in CD rats and CD-1 mice, despite a dose-dependent reduction in food intake and body weight in rats compared to controls, and a body weight reduction in mice at the highest dose, there was no compelling evidence for reductions in mortality rate. PMID:21079617
Unbearable weight: young adult women's experiences of being overweight.
Yu-Jen, Chang; Yiing-Mei, Liou; Shuh-Jen, Sheu; Mei-Yen, Chen
2004-06-01
Being overweight is a hazard to health. Overweight people have a very negative image due to the marketing strategies for weight reduction and beauty products. Young women establishing self-image, seeking affirmation of social peers, and looking for potential mates are usually concerned about their weight and figure. To investigate the experience of young women who think they are overweight, how they come to think in this way, and the impact of this thinking, this qualitative pilot study conducted semi-structured interviews with five participants. On the basis of the qualitative method, data was subjected to constant comparison and content analysis. The phenomenon can thus be described in three major categories: (1) Social labeling of the overweight - a slim image is overwhelmingly preferred; (2) Pursuing attractiveness or health - a self-struggling process; (3) Weight reduction and self control - an endless struggle. The result of the study suggests there is a need for a competitive image to counter current obsessions with painfully slender figures in society. To protect the public's mental and physical health, nurses should play an active role in weight education based on a deeper and more dynamic understanding of being overweight.
Reductions in Cardiovascular Risk After Bariatric Surgery
Benraoune, Fethi; Litwin, Sheldon E.
2012-01-01
Purpose of review Obesity is commonly associated with multiple conditions imparting adverse cardiovascular risk including, hypertension, dyslipidemia and insulin resistance or diabetes. In addition, sleep disordered breathing, inflammation, left ventricular hypertrophy, left atrial enlargement and subclinical left ventricular systolic and diastolic dysfunction may collectively contribute to increased cardiovascular morbidity and mortality. This review will describe improvements in cardiovascular risk factors after bariatric surgery. Recent findings All of the cardiovascular risk factors listed above are improved or even resolved after bariatric surgery. Cardiac structure and function also have shown consistent improvement after surgically-induced weight loss. The amount of improvement in cardiac risk factors is generally proportional to the amount of weight lost. The degree of weight loss varies with different bariatric procedures. Based on the improvement in risk profiles, it has been predicted that progression of atherosclerosis could be slowed and the 10 year risk of cardiac events would decline by ~ 50% in patients undergoing weight loss surgery. In keeping with these predictions, 2 studies have demonstrated reductions in 10-year total and cardiovascular mortality of approximately 50% in patients who had bariatric surgery. Summary These encouraging data support the continued, and perhaps expanded use of surgical procedures to induce weight loss in severely obese patients. PMID:21934498
Noise-reduction measurements of stiffened and unstiffened cylindrical models of an airplane fuselage
NASA Technical Reports Server (NTRS)
Willis, C. M.; Mayes, W. H.
1984-01-01
Noise-reduction measurements are presented for a stiffened and an unstiffened model of an airplane fuselage. The cylindrical models were tested in a reverberant-field noise environment over a frequency range from 20 Hz to 6 kHz. An unstiffened metal fuselage provided more noise reduction than a fuselage having the same sidewall weight divided between skin and stiffening stringers and ring frames. The addition of acoustic insulation to the models tended to smooth out the interior-noise spectrum by reducing or masking the noise associated with the structural response at some of the resonant frequencies.
Modification of near-wall coherent structures in polymer drag reduced flow: simulation
NASA Astrophysics Data System (ADS)
Dubief, Yves; White, Christopher; Shaqfeh, Eric; Moin, Parviz; Lele, Sanjiva
2002-11-01
Polymer drag reduced flows are investigated through direct numerical simulations of viscoelastic flows. The solver for the viscoelastic model (FENE-P) is based on higher-order finite difference schemes and a novel implicit time integration method. Its robustness allows the simulation of all drag reduction (DR) regimes from the onset to the maximum drag reduction (MDR). It also permits the use of realistic polymer length and concentration. The maximum polymer extension in our simulation matches that of a polystyrene molecule of 10^6 molecular weight. Two distinct regimes of polymer drag reduced flows are observed: at low drag reduction (LDR, DR< 40-50%), the near-wall structure is essentially similar to Newtonian wall turbulence whereas the high drag reduction regime (HDR, DR from 40-50% to MDR) shows significant differences in the organization of the coherent structures. The 3D information provided by numerical simulations allows the determination of the interaction of polymers and near-wall coherent structures. To isolate the contribution of polymers in the viscous sublayer, the buffer and the outer region of the flow, numerical experiments are performed where the polymer concentration is varied in the wall-normal direction. Finally a mechanism of polymer drag reduction derived from our results and PIV measurements is discussed.
Composite Structure Modeling and Analysis of Advanced Aircraft Fuselage Concepts
NASA Technical Reports Server (NTRS)
Mukhopadhyay, Vivek; Sorokach, Michael R.
2015-01-01
NASA Environmentally Responsible Aviation (ERA) project and the Boeing Company are collabrating to advance the unitized damage arresting composite airframe technology with application to the Hybrid-Wing-Body (HWB) aircraft. The testing of a HWB fuselage section with Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) construction is presently being conducted at NASA Langley. Based on lessons learned from previous HWB structural design studies, improved finite-element models (FEM) of the HWB multi-bay and bulkhead assembly are developed to evaluate the performance of the PRSEUS construction. In order to assess the comparative weight reduction benefits of the PRSEUS technology, conventional cylindrical skin-stringer-frame models of a cylindrical and a double-bubble section fuselage concepts are developed. Stress analysis with design cabin-pressure load and scenario based case studies are conducted for design improvement in each case. Alternate analysis with stitched composite hat-stringers and C-frames are also presented, in addition to the foam-core sandwich frame and pultruded rod-stringer construction. The FEM structural stress, strain and weights are computed and compared for relative weight/strength benefit assessment. The structural analysis and specific weight comparison of these stitched composite advanced aircraft fuselage concepts demonstrated that the pressurized HWB fuselage section assembly can be structurally as efficient as the conventional cylindrical fuselage section with composite stringer-frame and PRSEUS construction, and significantly better than the conventional aluminum construction and the double-bubble section concept.
Muramoto, Akiko; Matsushita, Madoka; Kato, Ayako; Yamamoto, Naoki; Koike, George; Nakamura, Masakazu; Numata, Takeyuki; Tamakoshi, Akiko; Tsushita, Kazuyo
2014-01-01
Adequate goal-setting is important in health counselling and treatment for obesity and overweight. We tried to determine the minimum weight reduction required for improvement of obesity-related risk factors and conditions in obese and overweight Japanese people, using a nationwide intervention programme database. Japanese men and women (n=3480; mean age±standard deviation [SD], 48.3±5.9 years; mean body mass index±SD, 27.7±2.5kgm(-2)) with "Obesity Disease" or "Metabolic Syndrome" participated in a 6-month lifestyle modification programme (specific health guidance) and underwent follow-up for 6 months thereafter. The relationship between percent weight reduction and changes in 11 parameters of obesity-related diseases were examined. Significant weight reduction was observed 6 months after the beginning of the programme, and it was maintained for 1 year. Concomitant improvements in parameters for obesity-related diseases were also observed. One-third of the subjects reduced their body weight by ≥3%. In the group exhibiting 1% to <3% weight reduction, plasma triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), haemoglobin A1c (HbA1c), aspartate aminotransferase (AST), alanine aminotransferase (ALT) and γ-glutamyl transpeptidase (γ-GTP) decreased significantly, and high-density lipoprotein cholesterol (HDL-C) increased significantly compared to the control group (±1% weight change group). In addition to the improvements of these 7 parameters (out of 11), significant reductions in systolic blood pressure (SBP), diastolic blood pressure (DBP), fasting plasma glucose (FPG) and uric acid (UA) (total 11 of 11 parameters) were observed in the group with 3% to <5% weight reduction. In the group with ≥5% weight reduction, the same 11 parameters also improved as those in the group with 3% to <5% weight reduction. The 6-month lifestyle modification programme induced significant weight reduction and significant improvement of parameters of obesity-related diseases. All the measured obesity-related parameters were significantly improved in groups with 3% to <5% and ≥5% weight reduction. Based on these findings, the minimum weight reduction required for improvement of obesity-related risk factors or conditions is 3% in obese and overweight (by WHO classification) Japanese people. Copyright © 2013 Asian Oceanian Association for the Study of Obesity. Published by Elsevier Ltd. All rights reserved.
Development and Evaluation of TiAl Sheet Structures for Hypersonic Applications
NASA Technical Reports Server (NTRS)
Draper, S. L.; Krause, D.; Lerch, B.; Locci, I. E.; Doehnert, B.; Nigam, R.; Das, G.; Sickles, P.; Tabernig, B.; Reger, N.;
2007-01-01
A cooperative program between the National Aeronautics and Space Administration (NASA), the Austrian Space Agency (ASA), Pratt & Whitney, Engineering Evaluation and Design, and Plansee AG was undertaken to determine the feasibility of achieving significant weight reduction of hypersonic propulsion system structures through the utilization of TiAl. A trade study defined the weight reduction potential of TiAl technologies as 25 to 35 percent compared to the baseline Ni-base superalloy for a stiffener structure in an inlet, combustor, and nozzle section of a hypersonic scramjet engine (ref. 1). A scramjet engine inlet cowl flap was designed, along with a representative subelement, using design practices unique to TiAl. A sub-element was fabricated and tested to assess fabricability and structural performance and validate the design system. The TiAl alloy selected was Plansee's third generation alloy Gamma Met PX (Plansee AG ), a high temperature, high strength gamma-TiAl alloy with high Nb content (refs. 2 and 3). Characterization of Gamma Met PX sheet, including tensile, creep, and fatigue testing was performed. Additionally, design-specific coupons were fabricated and tested in order to improve subelement test predictions. Based on the sheet characterization and results of the coupon tests, the subelement failure location and failure load were accurately predicted.
NASA Astrophysics Data System (ADS)
Roozen, N. B.; Muellner, H.; Labelle, L.; Rychtáriková, M.; Glorieux, C.
2015-06-01
Structural details and workmanship can cause considerable differences in sound insulation properties of timber frame partitions. In this study, the influence of panel fastening is investigated experimentally by means of standardized sound reduction index measurements, supported by detailed scanning laser Doppler vibrometry. In particular the effect of the number of screws used to fasten the panels to the studs, and the tightness of the screws, is studied using seven different configurations of lightweight timber frame building elements. In the frequency range from 300 to 4000 Hz, differences in the weighted sound reduction index RW as large as 10 dB were measured, suggesting that the method of fastening can have a large impact on the acoustic performance of building elements. Using the measured vibrational responses of the element, its acoustic radiation efficiency was computed numerically by means of a Rayleigh integral. The increased radiation efficiency partly explains the reduced sound reduction index. Loosening the screws, or reducing the number of screws, lowers the radiation efficiency, and significantly increases the sound reduction index of the partition.
Schernthaner, Guntram; Lavalle-González, Fernando J; Davidson, Jaime A; Jodon, Holly; Vijapurkar, Ujjwala; Qiu, Rong; Canovatchel, William
2016-11-01
To evaluate the proportion of patients with type 2 diabetes mellitus (T2DM) achieving reductions in both glycated hemoglobin (HbA1c) and body weight with canagliflozin, a sodium glucose co-transporter 2 inhibitor, versus sitagliptin over 52 weeks. Data were pooled from two, randomized, Phase 3 studies of canagliflozin 100 and 300 mg versus sitagliptin 100 mg as add-on to metformin, and canagliflozin 300 mg versus sitagliptin 100 mg as add-on to metformin plus sulfonylurea (N = 1856). The composite end points of change from baseline in both HbA1c <0% and body weight <0 kg, and attainment of HbA1c <7.0% and body weight reduction ≥5% at Week 52 were evaluated. Safety was assessed based on adverse event reports. Canagliflozin provided reductions in HbA1c and body weight over 52 weeks versus sitagliptin. A greater proportion of patients had both HbA1c and body weight reductions with canagliflozin 100 and 300 mg versus sitagliptin 100 mg (67.7%, 72.6%, and 44.1%, respectively). Among patients with HbA1c and body weight reductions, more patients achieved the composite end point of HbA1c <7.0% and body weight reduction ≥5% with canagliflozin 100 and 300 mg versus sitagliptin 100 mg (18.9%, 18.3%, and 5.7%, respectively). Canagliflozin was generally well tolerated. A greater proportion of patients with T2DM achieved reductions in both HbA1c and body weight, and more patients with HbA1c and body weight reductions achieved HbA1c <7.0% and body weight reduction ≥5% with canagliflozin versus sitagliptin over 52 weeks. www.ClinicalTrials.gov identifiers are NCT01106677; NCT01137812.
Vehicle Weight Reduction Study
DOT National Transportation Integrated Search
1981-03-01
This report studies the potential for primary weight reduction of a 1979 Oldsmobile Omega X-body four-door sedan, by substituting aluminum components for iron and steel components where suitable. A secondary weight reduction is mentioned but is not d...
USDA-ARS?s Scientific Manuscript database
The phenolic amine synephrine is a vascoconstrictor and bronchiectatic agent and may have promise as an aid to weight management and obesity reduction. Synephrine is structurally similar to the active ingredients of several commercial cold remedies. Some Citrus have been shown to possess high conc...
Keratin sponge/hydrogel part 1. fabrication and characterization
USDA-ARS?s Scientific Manuscript database
Keratin sponge/hydrogel products formed by either the oxidation or reduction of U.S. domestic fine- or coarse-grade wool exhibited distinctively different topologies and molecular weights of 6- 8 kDa and 40-60 kDa, each with unique macro-porous structure and microstructural behaviors. The sponge/ ...
Further weight reduction of applications in long glass reinforced polymers
NASA Astrophysics Data System (ADS)
Yanev, A.; Schijve, W.; Martin, C.; Brands, D.
2014-05-01
Long glass reinforced materials are broadly used in the automotive industry due to their good mechanical performance, competitive price and options for functional integration in order to reduce weight. With rapidly changing environmental requirements, a demand for further weight reduction is growing constantly. Designs in LGF-PP can bring light weight solutions in combination with system cost improvement. There are quite some possibilities for applying weight reduction technologies nowadays. These technologies have to be evaluated based on weight reduction potential, but also on mechanical performance of the end application, where the latter is often the key to success. Different weight reduction technologies are applied to SABIC®STAMAX{trade mark, serif} material, a long glass fiber reinforced polypropylene (LGF-PP), in order to investigate and define best application performance. These techniques include: chemical foaming, physical foaming and thin wall applications. Results from this research will be presented, giving a guideline for your development.
Metabolic adaptation to weight loss: implications for the athlete
2014-01-01
Optimized body composition provides a competitive advantage in a variety of sports. Weight reduction is common among athletes aiming to improve their strength-to-mass ratio, locomotive efficiency, or aesthetic appearance. Energy restriction is accompanied by changes in circulating hormones, mitochondrial efficiency, and energy expenditure that serve to minimize the energy deficit, attenuate weight loss, and promote weight regain. The current article reviews the metabolic adaptations observed with weight reduction and provides recommendations for successful weight reduction and long term reduced-weight maintenance in athletes. PMID:24571926
Yang, Woo Hwi; Heine, Oliver; Pauly, Sebastian; Kim, Pilsang; Bloch, Wilhelm; Mester, Joachim; Grau, Marijke
2015-01-01
Rapid weight reduction is part of the pre-competition routine and has been shown to negatively affect psychological and physiological performance of Taekwondo (TKD) athletes. This is caused by a reduction of the body water and an electrolyte imbalance. So far, it is unknown whether weight reduction also affects hemorheological properties and hemorheology-influencing nitric oxide (NO) signaling, important for oxygen supply to the muscles and organs. For this purpose, ten male TKD athletes reduced their body weight by 5% within four days (rapid weight reduction, RWR). After a recovery phase, athletes reduced body weight by 5% within four weeks (gradual weight reduction, GWR). Each intervention was preceded by two baseline measurements and followed by a simulated competition. Basal blood parameters (red blood cell (RBC) count, hemoglobin concentration, hematocrit, mean corpuscular volume, mean cellular hemoglobin and mean cellular hemoglobin concentration), RBC-NO synthase activation, RBC nitrite as marker for NO synthesis, RBC deformability and aggregation parameters were determined on a total of eight investigation days. Basal blood parameters were not affected by the two interventions. In contrast to GWR, RWR decreased activation of RBC-NO synthase, RBC nitrite, respective NO concentration and RBC deformability. Additionally, RWR increased RBC aggregation and disaggregation threshold. The results point out that a rapid weight reduction negatively affects hemorheological parameters and NO signaling in RBC which might limit performance capacity. Thus, GWR should be preferred to achieve the desired weight prior to a competition to avoid these negative effects.
Radiation detection system for portable gamma-ray spectroscopy
Rowland, Mark S [Alamo, CA; Howard, Douglas E [Livermore, CA; Wong, James L [Dublin, CA; Jessup, James L [Tracy, CA; Bianchini, Greg M [Livermore, CA; Miller, Wayne O [Livermore, CA
2006-06-20
A portable gamma ray detection apparatus having a gamma ray detector encapsulated by a compact isolation structure having at least two volumetrically-nested enclosures where at least one is a thermal shield. The enclosures are suspension-mounted to each other to successively encapsulate the detector without structural penetrations through the thermal shields. A low power cooler is also provided capable of cooling the detector to cryogenic temperatures without consuming cryogens, due to the heat load reduction by the isolation structure and the reduction in the power requirements of the cooler. The apparatus also includes a lightweight portable power source for supplying power to the apparatus, including to the cooler and the processing means, and reducing the weight of the apparatus to enable handheld operation or toting on a user's person.
NASA Astrophysics Data System (ADS)
Zama, Hideaki; Morishita, Tadataka
2000-10-01
New Ba(DPM)2-amine (DPM=dipivaloylmethane) adduct compounds were attempted to be synthesized from Ba(DPM)2 and amines. Complexes obtained were evaluated based on decreases of their weight with increasing temperature by thermogravimetry. The simple vaporizing phenomenon, showing a one-step weight-reduction curve, was observed only in the case of using tetraethylenepentamine and pentaethylenehexamine (pentaen) as adduct molecules, which have a simple chain structure and five to six primary and secondary amine radicals. From the viewpoint of applicability to film growth, they have the best structure based on a survey in this study using sixteen amine molecules with distinctive structures. When we used Ba(DPM)2-pentaen as a metalorganic source for a metalorganic chemical vapor deposition method at a vaporizing temperature of 140°C, the Ba supply rate remained stable within a standard deviation of 1.6% for over 300 h.
Application of laminar flow control to supersonic transport configurations
NASA Technical Reports Server (NTRS)
Parikh, P. G.; Nagel, A. L.
1990-01-01
The feasibility and impact of implementing a laminar flow control system on a supersonic transport configuration were investigated. A hybrid laminar flow control scheme consisting of suction controlled and natural laminar flow was developed for a double-delta type wing planform. The required suction flow rates were determined from boundary layer stability analyses using representative wing pressure distributions. A preliminary design of structural modifications needed to accommodate suction through a perforated titanium skin was carried out together with the ducting and systems needed to collect, compress and discharge the suction air. The benefits of reduced aerodynamic drag were weighed against the weight, volume and power requirement penalties of suction system installation in a mission performance and sizing program to assess the net benefits. The study showed a feasibility of achieving significant laminarization of the wing surface by use of a hybrid scheme, leading to an 8.2 percent reduction in the cruise drag. This resulted in an 8.5 percent reduction in the maximum takeoff weight and a 12 percent reduction in the fuel burn after the inclusion of the LFC system installation penalties. Several research needs were identified for a resolution of aerodynamics, structural and systems issues before these potential benefits could be realized in a practical system.
STUDIES ON STRUCTURAL UNITS OF THE γ-GLOBULINS
Edelman, G. M.; Poulik, M. D.
1961-01-01
When human and rabbit 7S γ-globulins were reduced in strong urea solutions by a number of procedures, their molecular weights fell to approximately ⅓ of the original values. Partial separation of the reduction products was achieved using chromatography and starch gel electrophoresis in urea solutions. One of the components of reduced human 7S γ-globulin was isolated by chromatography, identified by starch gel electrophoresis, and subjected to amino acid analyses. The amino acid composition of this component differed from that of the starting material and also from that of the remaining components. A reduced pathological macroglobulin dissociated to components with an average molecular weight of 41,000. Several reduced human myeloma proteins, when subjected to starch gel electrophoresis, yielded individual patterns that nevertheless had features in common with those of reduced normal γ-globulins. Reduction of normal and abnormal γ-globulins was accompanied by the appearance of titratable sulfhydryl groups. Chemical treatments other than reduction were used to determine the type of bond holding the subunits together. It was tentatively concluded that they were linked by disulfide bonds. An hypothesis is presented to relate the structural features of the various γ-globulins in terms of the multiplicity of polypeptide chains in these molecules. PMID:13725659
Reduction of Diffusion-Weighted Imaging Contrast of Acute Ischemic Stroke at Short Diffusion Times.
Baron, Corey Allan; Kate, Mahesh; Gioia, Laura; Butcher, Kenneth; Emery, Derek; Budde, Matthew; Beaulieu, Christian
2015-08-01
Diffusion-weighted imaging (DWI) of tissue water is a sensitive and specific indicator of acute brain ischemia, where reductions of the diffusion of tissue water are observed acutely in the stroke lesion core. Although these diffusion changes have been long attributed to cell swelling, the precise nature of the biophysical mechanisms remains uncertain. The potential cause of diffusion reductions after stroke was investigated using an advanced DWI technique, oscillating gradient spin-echo DWI, that enables much shorter diffusion times and can improve specificity for alterations of structure at the micron level. Diffusion measurements in the white matter lesions of patients with acute ischemic stroke were reduced by only 8% using oscillating gradient spin-echo DWI, in contrast to a 37% decrease using standard DWI. Neurite beading has recently been proposed as a mechanism for the diffusion changes after ischemic stroke with some ex vivo evidence. To explore whether beading could cause such differential results, simulations of beaded cylinders and axonal swelling were performed, yielding good agreement with experiment. Short diffusion times result in dramatically reduced diffusion contrast of human stroke. Simulations implicate a combination of neuronal beading and axonal swelling as the key structural changes leading to the reduced apparent diffusion coefficient after stroke. © 2015 American Heart Association, Inc.
McMillen, T S; Minami, E; Leboeuf, R C
2013-06-24
Obesity has become an epidemic in many countries and is supporting a billion dollar industry involved in promoting weight loss through diet, exercise and surgical procedures. Because of difficulties in maintaining body weight reduction, a pattern of weight cycling often occurs (so called 'yo-yo' dieting) that may result in deleterious outcomes to health. There is controversy about cardiovascular benefits of yo-yo dieting, and an animal model is needed to better understand the contributions of major diet and body weight changes on heart and vascular functions. Our purpose is to determine the effects of weight cycling on cardiac function and atherosclerosis development in a mouse model. We used low-density lipoprotein receptor-deficient mice due to their sensitivity to metabolic syndrome and cardiovascular diseases when fed high-fat diets. Alternating ad libitum feeding of high-fat and low-fat (rodent chow) diets was used to instigate weight cycling during a 29-week period. Glucose tolerance and insulin sensitivity tests were done at 22 and 24 weeks, echocardiograms at 25 weeks and atherosclerosis and plasma lipoproteins assessed at 29 weeks. Mice subjected to weight cycling showed improvements in glucose homeostasis during the weight loss cycle. Weight-cycled mice showed a reduction in the severity of atherosclerosis as compared with high-fat diet-fed mice. However, atherosclerosis still persisted in weight-cycled mice as compared with mice fed rodent chow. Cardiac function was impaired in weight-cycled mice and matched with that of mice fed only the high-fat diet. This model provides an initial structure in which to begin detailed studies of diet, calorie restriction and surgical modifications on energy balance and metabolic diseases. This model also shows differential effects of yo-yo dieting on metabolic syndrome and cardiovascular diseases.
Mensinger, Janell L; Calogero, Rachel M; Stranges, Saverio; Tylka, Tracy L
2016-10-01
Weight loss is the primary recommendation for health improvement in individuals with high body mass index (BMI) despite limited evidence of long-term success. Alternatives to weight-loss approaches (such as Health At Every Size - a weight-neutral approach) have been met with their own concerns and require further empirical testing. This study compared the effectiveness of a weight-neutral versus a weight-loss program for health promotion. Eighty women, aged 30-45 years, with high body mass index (BMI ≥ 30 kg/m(2)) were randomized to 6 months of facilitator-guided weekly group meetings using structured manuals that emphasized either a weight-loss or weight-neutral approach to health. Health measurements occurred at baseline, post-intervention, and 24-months post-randomization. Measurements included blood pressure, lipid panels, blood glucose, BMI, weight, waist circumference, hip circumference, distress, self-esteem, quality of life, dietary risk, fruit and vegetable intake, intuitive eating, and physical activity. Intention-to-treat analyses were performed using linear mixed-effects models to examine group-by-time interaction effects and between and within-group differences. Group-by-time interactions were found for LDL cholesterol, intuitive eating, BMI, weight, and dietary risk. At post-intervention, the weight-neutral program had larger reductions in LDL cholesterol and greater improvements in intuitive eating; the weight-loss program had larger reductions in BMI, weight, and larger (albeit temporary) decreases in dietary risk. Significant positive changes were observed overall between baseline and 24-month follow-up for waist-to-hip ratio, total cholesterol, physical activity, fruit and vegetable intake, self-esteem, and quality of life. These findings highlight that numerous health benefits, even in the absence of weight loss, are achievable and sustainable in the long term using a weight-neutral approach. The trial positions weight-neutral programs as a viable health promotion alternative to weight-loss programs for women of high weight. Copyright © 2016 Elsevier Ltd. All rights reserved.
An RCT of Nurse Coaching vs. Herbal CAM for Soldier Weight Reduction
2015-12-08
Coaching vs. Herbal CAM for Soldier Weight Reduction 5b. GRANT NUMBER HT9404-12-1-TS03 5c. PROGRAM ELEMENT NUMBER N/A 6. AUTHOR(S) 5d...coaching intervention and an herbal supplement for Service Member (SM) weight reduction over a 12-week period to evaluate their effectiveness...Title of Research Study or Evidence-Based Practice (EBP) Project An RCT of Nurse Coaching vs. Herbal CAM for Soldier Weight Reduction Period of Award
Structure formation control of foam concrete
NASA Astrophysics Data System (ADS)
Steshenko, Aleksei; Kudyakov, Aleksander; Konusheva, Viktoriya; Syrkin, Oleg
2017-01-01
The process of predetermined foam concrete structure formation is considered to be a crucial issue from the point of process control and it is currently understudied thus defining the need for additional research. One of the effective ways of structure formation control in naturally hardening foam concrete is reinforcement with dispersed fibers or introduction of plasticizers. The paper aims at studying the patterns of influence of microreinforcing and plasticizing additives on the structure and performance properties of foam concrete. Preparation of foam concrete mix has been conducted using one-step technology. The structure of modified foam concrete has been studied by means of electron microscopy. The cellular structure of foam concrete samples with the additives is homogeneous; the pores are uniformly distributed over the total volume. It has been revealed that introduction of the Neolas 5.2 plasticizer and microreinforcing fibers in the foam concrete mixture in the amount of 0.4 - 0.1 % by weight of cement leads to reduction of the average pore diameter in the range of 45.3 to 30.2 microns and the standard deviation of the pore average diameter from 23.6 to 9.2 in comparison with the sample without additive. Introduction of modifying additives has stimulated formation of a large number of closed pores. Thus porosity of conditionally closed pores has increased from 16.06 % to 34.48 %, which has lead to increase of frost resistance brand of foam concrete from F15 to F50 and to reduction of its water absorption by weight by 20 %.
Experiences with three different fiber supplements in weight reduction.
Birketvedt, Grethe Støa; Shimshi, Mona; Erling, Thom; Florholmen, Jon
2005-01-01
Fiber supplements added to a caloric diet have additional effects on weight reduction in overweight subjects. The aim of this study was to compare the effect of various commercial fiber supplements (glucomannan, guar gum and alginate) on weight reduction in healthy overweight subjects. One hundred and seventy six men and women were included to receive either active fiber substance or placebo in randomized placebo-controlled studies. The fiber supplements consisted of the viscous fibers glucomannan (Chrombalance), glucomannan and guar gum (Appe-Trim) and glucomannan, guar gum and alginat (Glucosahl). All fiber supplements plus a balanced 1200 kcal diet induced significantly weight reduction more than placebo and diet alone, during a five week observation period. However, there were no significant differences between the different fibers in their ability to induce weight reduction, which was approximately 0.8 kg/week (3.8 +/- 0.9, 4.4 +/- 2.0, 4.1 +/- 0.6 in the Chrombalance, Appe-Trim and Glucosahl group, respectively). Glucomannan induced body weight reduction in healthy overweight subjects, whereas the addition of guar gum and alginate did not seem to cause additional loss of weight.
The Effect of Weight Reduction on the Blood and Urine Measurements of College Wrestlers.
ERIC Educational Resources Information Center
Segurson, Jack
It has been suggested that the weight reduction practices of wrestlers results in kidney and liver problems. To observe the effect of wrestlers' weight reduction, diagnostic tests for kidney and liver problems were done on the blood and urine samples of 22 college wrestlers over the course of a wrestling season. Results obtained after reduction to…
DOE Office of Scientific and Technical Information (OSTI.GOV)
Khaleel, Mohammad A.; Sun, Xin; Simmons, Kevin L.
2008-05-01
This paper describes the fabrication process for the thin cast-in-place laminate glazing systems to be used in cars of the future to achieve the weight reduction goals of FreedomCAR. The primary objective of the project is to reduce vehicle weight, improve fuel economy, and reduce vehicle emissions through the use of structurally reliable, high acoustic performance and lightweight glazing systems with low manufacturing costs. Energy savings come from reducing weight by using thinner glazing: prior studies at Pacific Northwest National Laboratory (PNNL) have demonstrated a potential of 30% weight reductions compared with standard glazing system. Energy savings will also comemore » from reducing interior heat loads; that, in turn, will reduce the demand for air conditioning. The evaluation of alternative glazing concepts seek to improve acoustical performance such that reduced interior noise levels can be achieved while maintaining glazing at minimal thickness and weight levels. The most important factor in utilizing laminated glazing systems as vehicle side glass is its advantage in cost savings for material and manufacturing processes. To this end, a new, innovative manufacturing process is developed such that laminated glazing systems can be made with low cost in terms of raw materials and process-related equipment/facility investment.« less
USDA-ARS?s Scientific Manuscript database
Keratin was extracted from wool by reduction with 2-mercaptoethanol. It was isolated as intact keratin and characterized by its similar molecular weight, protein composition, and secondary structure to native keratin. Gel electrophoresis patterns and MALDI-TOF/TOF peptide sequences provided the ide...
Magnetic suspension and balance system advanced study
NASA Technical Reports Server (NTRS)
Boom, R. W.; Eyssa, Y. M.; Mcintosh, G. E.; Abdelsalam, M. K.
1985-01-01
An improved compact design for a superconducting magnetic suspension and balance system for an 8 ft. x 8 ft. transonic wind tunnel is developed. The original design of an MSBS in NASA Cr-3802 utilized 14 external superconductive coils and a superconductive solenoid in the airplane test model suspended in a wind tunnel. The improvements are in the following areas: test model solenoid options, dynamic force limits on the model, magnet cooling options, structure and cryogenic designs, power supply specifications, and cost and performance evaluations. The improvements are: MSBS cost reduction of 28%, weight; reduction of 43%, magnet system ampere-meter reduction of 38%, helium liquifier capacity reduction by 33%, magnet system stored energy reduction by 55%, AC loss to liquid helium reduced by 76%, system power supply reduced by 68%, test coil pole strength increased by 19%, wing magnetization increased by 40%, and control frequency limit increased by 200% from 10 Hz to 30 Hz. The improvements are due to: magnetic holmium coil forms in the test model, better rare earth permanent magnets in the wings, fiberglass-epoxy structure replacing stainless steel, better coil configuration, and new saddle roll coil design.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Degenhardt, R.; PFH, Private University of Applied Sciences Goettingen, Composite Engineering Campus Stade; Araujo, F. C. de
European aircraft industry demands for reduced development and operating costs. Structural weight reduction by exploitation of structural reserves in composite aerospace structures contributes to this aim, however, it requires accurate and experimentally validated stability analysis of real structures under realistic loading conditions. This paper presents different advances from the area of computational stability analysis of composite aerospace structures which contribute to that field. For stringer stiffened panels main results of the finished EU project COCOMAT are given. It investigated the exploitation of reserves in primary fibre composite fuselage structures through an accurate and reliable simulation of postbuckling and collapse. Formore » unstiffened cylindrical composite shells a proposal for a new design method is presented.« less
Yang, Wenjiao; Cai, Ying; Yin, Ronghua; Lin, Lisha; Li, Zhongkun; Wu, Mingyi; Zhao, Jinhua
2018-05-01
Sulfated polysaccharides such as fucosylated glycosaminoglycan and fucan sulfate from echinoderm possess complex chemical structure and various biological activities. The two sulfated polysaccharides were purified from the low-value sea cucumber Holothuria coluber. Their physicochemical properties and chemical structures were analyzed and characterized by chemical and instrumental methods. Structural analysis clarified that the sea cucumber fucosylated glycosaminoglycan contains a chondroitin sulfate-like backbone and fucosyl branches with four various sulfation patterns. The fucan sulfate with molecular weight of 64.6 kDa comprises a central core of regular α(1 → 4)-linked tetrasaccharide repeating units, each of which is linked by a 4-O-sulfated fucose residue. Anticoagulant assays indicated that these sulfated polysaccharides possessed strong APTT prolonging activities and intrinsic factor Xase inhibitory activities, both of which decreased with the reduction of their molecular weights. Our results expand knowledge on the structural types of sulfated polysaccharides from sea cucumbers and further illustrate their functionality. Copyright © 2018. Published by Elsevier B.V.
Impact damage in filament wound composite bottles
NASA Technical Reports Server (NTRS)
Highsmith, Alton L.
1993-01-01
Increasingly, composite materials are being used in advanced structural applications because of the significant weight savings they offer when compared to more traditional engineering materials. The higher cost of composites must be offset by the increased performance that results from reduced structural weight if these new materials are to be used effectively. At present, there is considerable interest in fabricating solid rocket motor cases out of composite materials, and capitalizing on the reduced structural weight to increase rocket performance. However, one of the difficulties that arises when composite materials are used is that composites can develop significant amounts of internal damage during low velocity impacts. Such low velocity impacts may be encountered in routine handling of a structural component like a rocket motor case. The ability to assess the reduction in structural integrity of composite motor cases that experience accidental impacts is essential if composite rocket motor cases are to be certified for manned flight. While experimental studies of the post-impact performance of filament wound composite motor cases haven been proven performed (2,3), scaling impact data from small specimens to full scale structures has proven difficult. If such a scaling methodology is to be achieved, an increased understanding of the damage processes which influence residual strength is required. The study described herein was part of an ongoing investigation of damage development and reduction of tensile strength in filament wound composites subjected to low velocity impacts. The present study, which focused on documenting the damage that develops in filament wound composites as a result of such impacts, included two distinct tasks. The first task was to experimentally assess impact damage in small, filament wound pressure bottles using x-ray radiography. The second task was to study the feasibility of using digital image processing techniques to assist in determining the 3-D distribution of damage from stereo x-ray pairs.
DeVita, Paul; Rider, Patrick; Hortobágyi, Tibor
2016-03-01
A consensus exists that high knee joint forces are a precursor to knee osteoarthritis and weight loss reduces these forces. Because large weight loss also leads to increased step length and walking velocity, knee contact forces may be reduced less than predicted by the magnitude of weight loss. The purpose was to determine the effects of weight loss on knee muscle and joint loads during walking in Class III obese adults. We determined through motion capture, force platform measures and biomechanical modeling the effects of weight loss produced by gastric bypass surgery over one year on knee muscle and joint loads during walking at a standard, controlled velocity and at self-selected walking velocities. Weight loss equaling 412 N or 34% of initial body weight reduced maximum knee compressive force by 824 N or 67% of initial body weight when walking at the controlled velocity. These changes represent a 2:1 reduction in knee force relative to weight loss when walking velocity is constrained to the baseline value. However, behavioral adaptations including increased stride length and walking velocity in the self-selected velocity condition attenuated this effect by ∼50% leading to a 392 N or 32% initial body weight reduction in compressive force in the knee joint. Thus, unconstrained walking elicited approximately 1:1 ratio of reduction in knee force relative to weight loss and is more indicative of walking behavior than the standard velocity condition. In conclusion, massive weight loss produces dramatic reductions in knee forces during walking but when patients stride out and walk faster, these favorable reductions become substantially attenuated. Copyright © 2016 Elsevier B.V. All rights reserved.
NASA Technical Reports Server (NTRS)
Glaessgen, Edward H.; Schoeppner, Gregory A.
2006-01-01
NASA Langley Research Center has successfully developed an electron beam freeform fabrication (EBF3) process, a rapid metal deposition process that works efficiently with a variety of weldable alloys. The EBF3 process can be used to build a complex, unitized part in a layer-additive fashion, although the more immediate payoff is for use as a manufacturing process for adding details to components fabricated from simplified castings and forgings or plate products. The EBF3 process produces structural metallic parts with strengths comparable to that of wrought product forms and has been demonstrated on aluminum, titanium, and nickel-based alloys to date. The EBF3 process introduces metal wire feedstock into a molten pool that is created and sustained using a focused electron beam in a vacuum environment. Operation in a vacuum ensures a clean process environment and eliminates the need for a consumable shield gas. Advanced metal manufacturing methods such as EBF3 are being explored for fabrication and repair of aerospace structures, offering potential for improvements in cost, weight, and performance to enhance mission success for aircraft, launch vehicles, and spacecraft. Near-term applications of the EBF3 process are most likely to be implemented for cost reduction and lead time reduction through addition of details onto simplified preforms (casting or forging). This is particularly attractive for components with protruding details that would require a significantly large volume of material to be machined away from an oversized forging, offering significant reductions to the buy-to-fly ratio. Future far-term applications promise improved structural efficiency through reduced weight and improved performance by exploiting the layer-additive nature of the EBF3 process to fabricate tailored unitized structures with functionally graded microstructures and compositions.
de Kerviler, S; Hüsler, R; Banic, A; Constantinescu, M A
2009-05-01
This study analyzed the impact of weight reduction method, preoperative, and intraoperative variables on the outcome of reconstructive body contouring surgery following massive weight reduction. All patients presenting with a maximal BMI >/=35 kg/m(2) before weight reduction who underwent body contouring surgery of the trunk following massive weight loss (excess body mass index loss (EBMIL) >/= 30%) between January 2002 and June 2007 were retrospectively analyzed. Incomplete records or follow-up led to exclusion. Statistical analysis focused on weight reduction method and pre-, intra-, and postoperative risk factors. The outcome was compared to current literature results. A total of 104 patients were included (87 female and 17 male; mean age 47.9 years). Massive weight reduction was achieved through bariatric surgery in 62 patients (59.6%) and dietetically in 42 patients (40.4%). Dietetically achieved excess body mass index loss (EBMIL) was 94.20% and in this cohort higher than surgically induced reduction EBMIL 80.80% (p < 0.01). Bariatric surgery did not present increased risks for complications for the secondary body contouring procedures. The observed complications (26.9%) were analyzed for risk factors. Total tissue resection weight was a significant risk factor (p < 0.05). Preoperative BMI had an impact on infections (p < 0.05). No impact on the postoperative outcome was detected in EBMIL, maximal BMI, smoking, hemoglobin, blood loss, body contouring technique or operation time. Corrective procedures were performed in 11 patients (10.6%). The results were compared to recent data. Bariatric surgery does not increase risks for complications in subsequent body contouring procedures when compared to massive dietetic weight reduction.
Efficacy of a "small-changes" workplace weight loss initiative on weight and productivity outcomes.
Zinn, Caryn; Schofield, Grant M; Hopkins, Will G
2012-10-01
The effect of weight reduction on workplace productivity is unknown. We have investigated a "small-changes" workplace weight loss intervention on weight and productivity outcomes. Overweight/obese employees at two New Zealand worksites (n = 102) received the 12-week intervention. One site received an extra 9-month weight-maintenance component. Magnitudes of effects on weight and productivity were assessed via standardization. Both groups reduced weight at 12 weeks and maintained lost weight at 12 months. There were small possible improvements in productivity at one worksite and trivial reductions at the other by 12 weeks, with little subsequent change during maintenance in either group. At an individual level, weight change was associated with at most only small improvements or small reductions in productivity. Workplace weight loss initiatives may need to be more intensive or multidimensional to enhance productivity.
Advanced composite structural concepts and material technologies for primary aircraft structures
NASA Technical Reports Server (NTRS)
Jackson, Anthony
1991-01-01
Structural weight savings using advanced composites have been demonstrated for many years. Most military aircraft today use these materials extensively and Europe has taken the lead in their use in commercial aircraft primary structures. A major inhibiter to the use of advanced composites in the United States is cost. Material costs are high and will remain high relative to aluminum. The key therefore lies in the significant reduction in fabrication and assembly costs. The largest cost in most structures today is assembly. As part of the NASA Advanced Composite Technology Program, Lockheed Aeronautical Systems Company has a contract to explore and develop advanced structural and manufacturing concepts using advanced composites for transport aircraft. Wing and fuselage concepts and related trade studies are discussed. These concepts are intended to lower cost and weight through the use of innovative material forms, processes, structural configurations and minimization of parts. The approach to the trade studies and the downselect to the primary wing and fuselage concepts is detailed. The expectations for the development of these concepts is reviewed.
Optimized bio-inspired stiffening design for an engine nacelle.
Lazo, Neil; Vodenitcharova, Tania; Hoffman, Mark
2015-11-04
Structural efficiency is a common engineering goal in which an ideal solution provides a structure with optimized performance at minimized weight, with consideration of material mechanical properties, structural geometry, and manufacturability. This study aims to address this goal in developing high performance lightweight, stiff mechanical components by creating an optimized design from a biologically-inspired template. The approach is implemented on the optimization of rib stiffeners along an aircraft engine nacelle. The helical and angled arrangements of cellulose fibres in plants were chosen as the bio-inspired template. Optimization of total displacement and weight was carried out using a genetic algorithm (GA) coupled with finite element analysis. Iterations showed a gradual convergence in normalized fitness. Displacement was given higher emphasis in optimization, thus the GA optimization tended towards individual designs with weights near the mass constraint. Dominant features of the resulting designs were helical ribs with rectangular cross-sections having large height-to-width ratio. Displacement reduction was at 73% as compared to an unreinforced nacelle, and is attributed to the geometric features and layout of the stiffeners, while mass is maintained within the constraint.
NASA Technical Reports Server (NTRS)
Davis, John G., Jr.
1992-01-01
NASA's Advanced Composites Program (ACT) was initiated in 1988. A National Research Announcement was issued to solicit innovative ideas that could significantly contribute to development and demonstration of an integrated technology data base and confidence level that permits cost-effective use of composite primary structures in transport aircraft. Fifteen contracts were awarded by the Spring of 1989 and the participants include commercial and military airframe manufacturers, materials developers and suppliers, universities, and government laboratories. The program approach is to develop materials, structural mechanics methodology, design concepts, and fabrication procedures that offer the potential to make composite structures cost-effective compared to aluminum structure. Goals for the ACT program included 30-50 percent weight reduction, 20-25 percent acquisition cost reduction, and provided the scientific basis for predicting materials and structures performance. This paper provides an overview of the ACT program status, plans, and selected technical accomplishments. Sixteen additional papers, which provide more detailed information on the research and development accomplishments, are contained in this publication.
Hot Rolling Scrap Reduction through Edge Cracking and Surface Defects Control
DOE Office of Scientific and Technical Information (OSTI.GOV)
Beaudoin, Armand
2016-05-29
The design of future aircraft must address the combined demands for fuel efficiency, reduced emissions and lower operating costs. One contribution to these goals is weight savings through the development of new alloys and design techniques for airframe structures. This research contributes to the light-weighting through fabrication of monolithic components from advanced aluminum alloys by making a link between alloy processing history and in-service performance. Specifically, this research demonstrates the link between growing cracks with features of the alloy microstructure that follow from thermo-mechanical processing. This is achieved through a computer model of crack deviation. The model is validated againstmore » experimental data from production scale aluminum alloy plate, and demonstration of the effect of changes in processing history on crack growth is made. The model is cast in the open-source finite element code WARP3D, which is freely downloadable and well documented. This project provides benefit along several avenues. First, the technical contribution of the computer model offers the materials engineer a critical means of providing guidance both upstream, to process tuning to achieve optimal properties, and downstream, to enhance fault tolerance. Beyond the fuel savings and emissions reduction inherent in the light-weighting of aircraft structures, improved fault tolerance addresses demands for longer inspection intervals over baseline, and a lower life cycle cost.« less
NASA Technical Reports Server (NTRS)
1975-01-01
The propulsion performance, acoustic, structural, and systems changes to a 727-200 airplane retrofitted with a refan modification of the JT8D turbofan engine are evaluated. Model tests, design of certifiable airplane retrofit kit hardware, manufacture of test hardware, ground test of a current production JT8D engine, followed by test of the same engine modified to the refan configuration, detailed analyses of the retrofit impact on airplane airworthiness, performance, and noise, and a preliminary analysis of retrofit costs are included. Results indicate that the refan retrofit of the 727-200 would be certifiable and would result in a 6-to 8 EPNdb reduction in effective perceived noise level (EPNL) at the FAR 36 measuring points and an annoyance-weighted footprint area reduction of 68% to 83%. The installed refan engine is estimated to provide 14% greater takeoff thrust at zero velocity and 10% greater thrust at 100 kn (51.4 m/s). There would be an approximate 0.6% increase in cruise specific fuel consumption (SFC). The refan engine performance in conjunction with the increase in stalled weight results in a range reduction of approximately 15% over the unmodified airplane at the same brake release gross weight (BRGW), with a block fuel increase of 1.5% to 3%. With the particular model 727 that was studied, however, it is possible to operate the airplane (with minor structural modifications) at a higher BRGW and increase the range up to approximately 15% relative to the nonrefanned airplane (with equal or slightly increased noise levels). The JT8D refan engine also improves the limited-field range of the airplane.
Sayed, Ramy K A; de Leonardis, Erika Chacin; Guerrero-Martínez, José A; Rahim, Ibtissem; Mokhtar, Doaa M; Saleh, Abdelmohaimen M; Abdalla, Kamal E H; Pozo, María J; Escames, Germaine; López, Luis C; Acuña-Castroviejo, Darío
2016-10-01
The gastrocnemius muscle (GM) of young (3months) and aged (12months) female wild-type C57/BL6 mice was examined by light and electron microscopy, looking for the presence of structural changes at early stage of the aging process. Morphometrical parameters including body and gastrocnemius weights, number and type of muscle fibers, cross section area (CSA), perimeter, and Feret's diameter of single muscle fiber, were measured. Moreover, lengths of the sarcomere, A-band, I-band, H-zone, and number and CSA of intermyofibrillar mitochondria (IFM), were also determined. The results provide evidence that 12month-old mice had significant changes on skeletal muscle structure, beginning with the reduction of gastrocnemius weight to body weight ratio, compatible with an early loss of skeletal muscle function and strength. Moreover, light microscopy revealed increased muscle fibers size, with a significant increase on their CSA, perimeter, and diameter of both type I and type II muscle fibers, and a reduction in the percentage of muscle area occupied by type II fibers. Enhanced connective tissue infiltrations, and the presence of centrally nucleated muscle fibers, were also found in aged mice. These changes may underlie an attempt to compensate the loss of muscle mass and muscle fibers number. Furthermore, electron microscopy discovered a significant age-dependent increase in the length of sarcomeres, I and H bands, and reduction on the overlapped actin/myosin length, supporting contractile force loss with age. Electron microscopy also showed an increased number and CSA of IFM with age, which may reveal more endurance at 12months of age. Together, mice at early stage of aging already show significant changes in gastrocnemius muscle morphology and ultrastructure that are suggestive of the onset of sarcopenia. Copyright © 2016 Elsevier Inc. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Basu, Rupa, E-mail: Rupa.Basu@oehha.ca.gov; Harris, Maria; Sie, Lillian
Relationships between prenatal exposure to fine particles (PM{sub 2.5}) and birth weight have been observed previously. Few studies have investigated specific constituents of PM{sub 2.5}, which may identify sources and major contributors of risk. We examined the effects of trimester and full gestational prenatal exposures to PM{sub 2.5} mass and 23 PM{sub 2.5} constituents on birth weight among 646,296 term births in California between 2000 and 2006. We used linear and logistic regression models to assess associations between exposures and birth weight and risk of low birth weight (LBW; <2500 g), respectively. Models were adjusted for individual demographic characteristics, apparentmore » temperature, month and year of birth, region, and socioeconomic indicators. Higher full gestational exposures to PM{sub 2.5} mass and several PM{sub 2.5} constituents were significantly associated with reductions in term birth weight. The largest reductions in birth weight were associated with exposure to vanadium, sulfur, sulfate, iron, elemental carbon, titanium, manganese, bromine, ammonium, zinc, and copper. Several of these PM{sub 2.5} constituents were associated with increased risk of term LBW. Reductions in birth weight were generally larger among younger mothers and varied by race/ethnicity. Exposure to specific constituents of PM{sub 2.5}, especially traffic-related particles, sulfur constituents, and metals, were associated with decreased birth weight in California. -- Highlights: • Examine full gestational and trimester fine particle and its constituents on term birth weight. • Fine particles and several of its constituents associated with birth weight reductions. • Largest reductions for traffic-related particles, sulfur constituents, and metals. • Greater birth weight reductions for younger mothers, and varied by race/ethnicity.« less
Foroughi, Moein; Malekmohammad, Majid; Adimi, Parisa
2016-05-01
Obstructive sleep apnea (OSA) together with metabolic disorders is common in severely obese patients. Weight reduction is considered as a treatment modality in these cases while few of them can succeed in considerable weight loss. Here, we present a severely obese man with body mass index of 54 suffered from OSA, type 2 diabetes, hypothyroidism, and hypertension. He intentionally lost 80 kilograms weight during the 2-year follow-up. Diabetes and hypertension completely resolved with considerable improvement in OSA syndrome after this huge weight reduction.
NASA Astrophysics Data System (ADS)
Adhikari, Pashupati Raj
Materials selection processes have been the most important aspects in product design and development. Knowledge-based system (KBS) and some of the methodologies used in the materials selection for the design of aircraft cabin metallic structures are discussed. Overall aircraft weight reduction means substantially less fuel consumption. Part of the solution to this problem is to find a way to reduce overall weight of metallic structures inside the cabin. Among various methodologies of materials selection using Multi Criterion Decision Making (MCDM) techniques, a few of them are demonstrated with examples and the results are compared with those obtained using Ashby's approach in materials selection. Pre-defined constraint values, mainly mechanical properties, are employed as relevant attributes in the process. Aluminum alloys with high strength-to-weight ratio have been second-to-none in most of the aircraft parts manufacturing. Magnesium alloys that are much lighter in weight as alternatives to the Al-alloys currently in use in the structures are tested using the methodologies and ranked results are compared. Each material attribute considered in the design are categorized as benefit and non-benefit attribute. Using Ashby's approach, material indices that are required to be maximized for an optimum performance are determined, and materials are ranked based on the average of consolidated indices ranking. Ranking results are compared for any disparity among the methodologies.
AN ASSESSMENT OF MCNP WEIGHT WINDOWS
DOE Office of Scientific and Technical Information (OSTI.GOV)
J. S. HENDRICKS; C. N. CULBERTSON
2000-01-01
The weight window variance reduction method in the general-purpose Monte Carlo N-Particle radiation transport code MCNPTM has recently been rewritten. In particular, it is now possible to generate weight window importance functions on a superimposed mesh, eliminating the need to subdivide geometries for variance reduction purposes. Our assessment addresses the following questions: (1) Does the new MCNP4C treatment utilize weight windows as well as the former MCNP4B treatment? (2) Does the new MCNP4C weight window generator generate importance functions as well as MCNP4B? (3) How do superimposed mesh weight windows compare to cell-based weight windows? (4) What are the shortcomingsmore » of the new MCNP4C weight window generator? Our assessment was carried out with five neutron and photon shielding problems chosen for their demanding variance reduction requirements. The problems were an oil well logging problem, the Oak Ridge fusion shielding benchmark problem, a photon skyshine problem, an air-over-ground problem, and a sample problem for variance reduction.« less
Workplace Interventions to Prevent Type 2 Diabetes Mellitus: a Narrative Review
Fedewa, Allison; Moran, Margaret; O’Brien, Matthew; Ackermann, Ronald; Kullgren, Jeffrey T.
2017-01-01
Purpose of review This study aims to summarize the recent peer-reviewed literature on workplace interventions for prevention of type 2 diabetes mellitus (T2DM), including studies that translate the Diabetes Prevention Program (DPP) curriculum to workplace settings (n = 10) and those that use different intervention approaches to achieve the specific objective of T2DM prevention among employees (n = 3). Recent findings Weight reduction was achieved through workplace interventions to prevent T2DM, though such interventions varied substantially in their effectiveness. The greatest weight loss was reported among intensive lifestyle interventions (i.e., at least 4 months in duration) that implemented the structured DPP curriculum (n = 3). Weight reduction was minimal among less intensive interventions, including those that substantially modified the DPP curriculum (n = 2) and those that used non-DPP intervention approaches to prevent T2DM (n = 3). Most studies (n = 12) reported increased levels of physical activity following the intervention. Summary Implementation of the DPP in workplaces may be an effective strategy to prevent T2DM among employees. PMID:28150162
Hyakutake, Manami; Tomizawa, Satoshi; Mizuno, Kouhei; Abe, Hideki
2014-01-01
Polyhydroxyalkanoate (PHA)-producing Bacillus strains express class IV PHA synthase, which is composed of the subunits PhaR and PhaC. Recombinant Escherichia coli expressing PHA synthase from Bacillus cereus strain YB-4 (PhaRCYB-4) showed an unusual reduction of the molecular weight of PHA produced during the stationary phase of growth. Nuclear magnetic resonance analysis of the low-molecular-weight PHA revealed that its carboxy end structure was capped by ethanol, suggesting that the molecular weight reduction was the result of alcoholytic cleavage of PHA chains by PhaRCYB-4 induced by endogenous ethanol. This scission reaction was also induced by exogenous ethanol in both in vivo and in vitro assays. In addition, PhaRCYB-4 was observed to have alcoholysis activity for PHA chains synthesized by other synthases. The PHA synthase from Bacillus megaterium (PhaRCBm) from another subgroup of class IV synthases was also assayed and was shown to have weak alcoholysis activity for PHA chains. These results suggest that class IV synthases may commonly share alcoholysis activity as an inherent feature. PMID:24334666
Research of low cost wind generator rotors
NASA Technical Reports Server (NTRS)
Fertis, D. G.; Ross, R. S.
1978-01-01
A feasibility program determined that it would be possible to significantly reduce the cost of manufacturing wind generator rotors by making them of cast urethane. Several high modulus urethanes which were structurally tested were developed. A section of rotor was also cast and tested showing the excellent aerodynamic surface which results. A design analysis indicated that a cost reduction of almost ten to one can be achieved with a small weight increase to achieve the same structural integrity as expected of current rotor systems.
Sato, Fumihiko; Tamura, Yoshifumi; Watada, Hirotaka; Kumashiro, Naoki; Igarashi, Yasuhiro; Uchino, Hiroshi; Maehara, Tadayuki; Kyogoku, Shinsuke; Sunayama, Satoshi; Sato, Hiroyuki; Hirose, Takahisa; Tanaka, Yasushi; Kawamori, Ryuzo
2007-08-01
Although moderate weight reduction is recommended as primary therapy of metabolic syndrome, little information is known regarding metabolic changes associated with moderate weight reduction in nondiabetic obese subjects. The aim of this study was to determine the effects of a moderate weight reduction program on intracellular lipid and glucose metabolism in muscle and liver. Data for 13 nondiabetic obese subjects were evaluated. Subjects were put on a 3-month mildly hypocaloric diet therapy (approximately 35 kcal/kg of ideal body weight). Intrahepatic lipid (IHL) and intramyocellular lipid were measured by using (1)H magnetic resonance spectroscopy. Peripheral insulin sensitivity and splanchnic glucose uptake were evaluated by euglycemic-hyperinsulinemic clamp with oral glucose load. Diet therapy for 3 months resulted in 6% reduction in body weight (from 99.9 +/- 7.3 to 93.8 +/- 6.6 kg, P < 0.0001). This change was accompanied by reduction of plasma glucose and insulin excursions during 75-g oral glucose tolerance tests, decrease in diastolic blood pressure, glycated hemoglobin, serum low-density lipoprotein cholesterol, and triglyceride. These changes were also accompanied by a decrease in IHL (from 12.9 to 8.2%, P < 0.01) and increase in splanchnic glucose uptake (from 13.5 to 35.0%, P < 0.03). On the other hand, the diet program did not affect intramyocellular lipid or glucose infusion rate during euglycemic hyperinsulinemic clamp. Our results suggest that moderate weight reduction in obese subjects decreased IHL and augmented splanchnic glucose uptake. This mechanism is at least in part involved in improvement of glucose metabolism by moderate weight reduction in obese subjects.
Efficient, Multi-Scale Designs Take Flight
NASA Technical Reports Server (NTRS)
2003-01-01
Engineers can solve aerospace design problems faster and more efficiently with a versatile software product that performs automated structural analysis and sizing optimization. Collier Research Corporation's HyperSizer Structural Sizing Software is a design, analysis, and documentation tool that increases productivity and standardization for a design team. Based on established aerospace structural methods for strength, stability, and stiffness, HyperSizer can be used all the way from the conceptual design to in service support. The software originated from NASA s efforts to automate its capability to perform aircraft strength analyses, structural sizing, and weight prediction and reduction. With a strategy to combine finite element analysis with an automated design procedure, NASA s Langley Research Center led the development of a software code known as ST-SIZE from 1988 to 1995. Collier Research employees were principal developers of the code along with Langley researchers. The code evolved into one that could analyze the strength and stability of stiffened panels constructed of any material, including light-weight, fiber-reinforced composites.
Fitzpatrick, Stephanie L; Bandeen-Roche, Karen; Stevens, Victor J; Coughlin, Janelle W; Rubin, Richard R; Brantley, Phillip J; Funk, Kristine L; Svetkey, Laura P; Jerome, Gerald J; Dalcin, Arlene; Charleston, Jeanne; Appel, Lawrence J
2014-04-01
To examine the behavioral processes through which lifestyle interventions impacted weight loss. The analyses were limited to overweight and obese Black and White adults randomized to a PREMIER lifestyle intervention (N = 501). Structural equation modeling was conducted to test the direct and indirect relationships of session attendance, days of self-monitoring diet and exercise, change in diet composition and exercise, and 6-month weight change. Greater session attendance was associated with increased self-monitoring, which was in turn significantly related to reduction in percent energy from total fat consumed. Change in percent energy from fat and self-monitoring was associated with 6-month percent change in weight. Both a decrease in fat intake and increase in self-monitoring are potential mediators of the relationship between attendance and weight change. The findings provide a reasonable model that suggests regular session attendance and use of behavioral strategies like self-monitoring are associated with improved behavioral outcomes that are associated with weight loss. Copyright © 2013 The Obesity Society.
Peng, Po-Jui; Ho, Pei-Shen; Tsai, Chia-Kuang; Huang, San-Yuan; Liang, Chih-Sung
A number of research studies support the weight loss effects of metformin and topiramate for obese people with schizophrenia. However, only a few studies have addressed the sustainability of the body weight reduction after discontinuation of these drugs. Moreover, head-to-head studies are still lacking. The study aims to evaluate and compare the efficacy of metformin and topiramate in weight reduction and weight maintenance after discontinuation of these drugs in obese people with schizophrenia. Twenty-two obese inpatients with schizophrenia were recruited and randomized into the metformin group (n = 11; daily dose, 1000 mg) and the topiramate group (n = 11; daily dose, 100 mg). A head-to-head, fixed-dose, and single-blinded design was used. Ten obese patients with schizophrenia of similar sex as that of the treated group were included as the control group. After a 4-month treatment, the metformin group showed a body weight reduction of 3.8 kg, and the topiramate group showed a reduction of 2.7 kg. However, the reduction could be sustained only in the metformin group at 3 and 9 months after metformin discontinuation. Interestingly, 3 months after treatment discontinuation, leptin levels showed a reduction in both metformin (baseline, 25.3 ± 14.7, week 7: 5.7 ± 3.7 ng/mL) and topiramate (baseline: 28.4 ± 16.1, week 7: 9.2 ± 15.5 ng/mL) groups. The trend of weight changes supports the superiority of metformin at 1000 mg/d over topiramate at 100 mg/d in weight reduction and weight maintenance.
Rheologically interesting polysaccharides from yeasts
NASA Technical Reports Server (NTRS)
Petersen, G. R.; Nelson, G. A.; Cathey, C. A.; Fuller, G. G.
1989-01-01
We have examined the relationships between primary, secondary, and tertiary structures of polysaccharides exhibiting the rheological property of friction (drag) reduction in turbulent flows. We found an example of an exopolysaccharide from the yeast Cryptococcus laurentii that possessed high molecular weight but exhibited lower than expected drag reducing activity. Earlier correlations by Hoyt showing that beta 1 --> 3, beta 2 --> 4, and alpha 1 --> 3 linkages in polysaccharides favored drag reduction were expanded to include correlations to secondary structure. The effect of sidechains in a series of gellan gums was shown to be related to sidechain length and position. Disruption of secondary structure in drag reducing polysaccharides reduced drag reducing activity for some but not all exopolysaccharides. The polymer from C. laurentii was shown to be more stable than xanthan gum and other exopolysaccharides under the most vigorous of denaturing conditions. We also showed a direct relationship between extensional viscosity measurements and the drag reducing coefficient for four exopolysaccharides.
Integrated multidisciplinary design optimization of rotorcraft
NASA Technical Reports Server (NTRS)
Adelman, Howard M.; Mantay, Wayne R.
1989-01-01
The NASA/Army research plan for developing the logic elements for helicopter rotor design optimization by integrating appropriate disciplines and accounting for important interactions among the disciplines is discussed. The paper describes the optimization formulation in terms of the objective function, design variables, and constraints. The analysis aspects are discussed, and an initial effort at defining the interdisciplinary coupling is summarized. Results are presented on the achievements made in the rotor aerodynamic performance optimization for minimum hover horsepower, rotor dynamic optimization for vibration reduction, rotor structural optimization for minimum weight, and integrated aerodynamic load/dynamics optimization for minimum vibration and weight.
Large Scale Composite Manufacturing for Heavy Lift Launch Vehicles
NASA Technical Reports Server (NTRS)
Stavana, Jacob; Cohen, Leslie J.; Houseal, Keth; Pelham, Larry; Lort, Richard; Zimmerman, Thomas; Sutter, James; Western, Mike; Harper, Robert; Stuart, Michael
2012-01-01
Risk reduction for the large scale composite manufacturing is an important goal to produce light weight components for heavy lift launch vehicles. NASA and an industry team successfully employed a building block approach using low-cost Automated Tape Layup (ATL) of autoclave and Out-of-Autoclave (OoA) prepregs. Several large, curved sandwich panels were fabricated at HITCO Carbon Composites. The aluminum honeycomb core sandwich panels are segments of a 1/16th arc from a 10 meter cylindrical barrel. Lessons learned highlight the manufacturing challenges required to produce light weight composite structures such as fairings for heavy lift launch vehicles.
Body weight reduction and metformin: Roles in polycystic ovary syndrome.
Al-Nozha, Omar; Habib, Fawziah; Mojaddidi, Moaz; El-Bab, Mohamed Fath
2013-04-01
Polycystic ovary syndrome (PCOS) is a common problem in women at fertile age. A prospective study was conducted to clarify the pathophysiological responses during an application of insulin sensitizer, metformin and weight reduction therapy at the Gynecology Center in Ohud hospital, in AL-Madinah AL-Munawarah, Kingdom of Saudi Arabia. Twenty healthy women served as controls and 180 PCOS women divided into three groups participated in the study. First group was treated with Clomid citrate 100mg/day from the 2nd day of menses to the 6th day plus gonadotrophin from day three to the 13th. Group II was treated as group I plus 850mg metformin twice a day and group III was treated as group I plus weight reduction. Clinical symptoms, menstrual pattern, hirsutism, blood glucose, body mass index, waist-to-hip ratio, insulin, hormonal, and lipid profiles were assessed pre- and post treatment. Insulin resistance was calculated. PCOS women had significantly higher values than the healthy women in most of the measurements. Metformin and weight reduction therapy resulted in a significant decrease in the fasting insulin, glucose/insulin ratio and HOMA-IR. Metformin and weight reduction therapy resulted in a significant decrease in the lipid parameters, testosterone, LH/FSH ratio, SHBG, and prolactin levels. HOMA-IR was significantly higher in women with PCOS. HOMA-IR was positively correlated with testosterone, estradiol, TG, total cholesterol and LDL-cholesterol parameters, and negatively correlated with HDL-cholesterol and FSH levels. Metformin therapy and weight reduction had favorable influences on the basic metabolic and hormonal profiles in women with PCOS and that metformin and lifestyle modification (weight reduction via diet restriction or exercise) resulted in a significantly greater weight loss than hormonal therapy alone. Metformin and weight reduction therapy decreased also hyperandrogenism and insulin resistance. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.
Application of fiber-reinforced bismaleimide materials to aircraft nacelle structures
NASA Technical Reports Server (NTRS)
Peros, Vasilios; Ruth, John; Trawinski, David
1992-01-01
Existing aircraft engine nacelle structures employ advanced composite materials to reduce weight and thereby increase overall performance. Use of advanced composite materials on existing aircraft nacelle structures includes fiber-reinforced epoxy structures and has typically been limited to regions furthest away from the hot engine core. Portions of the nacelle structure that are closer to the engine require materials with a higher temperature capability. In these portions, existing nacelle structures employ aluminum sandwich construction and skin/stringer construction. The aluminum structure is composed of many detail parts and assemblies and is usually protected by some form of ablative, insulator, or metallic thermal shield. A one-piece composite inner cowl for a new-generation engine nacelle structure has been designed using fiber-reinforced bismaleimide (BMI) materials and honeycomb core in a sandwich construction. The new composite design has many advantages over the existing aluminum structure. Multiple details were integrated into the one-piece composite design, thereby significantly reducing the number of detail parts and fasteners. The use of lightweight materials and the reduction of the number of joints result in a significant weight reduction over the aluminum design; manufacturing labor and the overall number of tools required have also been reduced. Several significant technical issues were addressed in the development of a BMI composite design. Technical evaluation of the available BMI systems led to the selection of a toughened BMI material which was resistant to microcracking under thermal cyclic loading and enhanced the damage tolerance of the structure. Technical evaluation of the degradation of BMI materials in contact with aluminum and other metals validated methods for isolation of the various materials. Graphite-reinforced BMI in contact with aluminum and some steels was found to degrade in salt spray testing. Isolation techniques such as those used for graphite-reinforced epoxy structures were shown to provide adequate protection. The springback and producibility of large BMI structures were evaluated by manufacturing prototype hardware which had the full-scale cross section of the one-piece composite structure.
Light Duty Truck Weight Reduction Evaluation
DOT National Transportation Integrated Search
1980-10-01
The objectives of this program were to identify the weight reduction potential of pickup trucks, vans, and utility vehicles less than or equal to 8500 lb. gross vehicle weight through design modification, redesign, and material substitution; and more...
Self-efficacy and dietary fat reduction behaviors in obese African-American and white mothers.
Chang, Mei-Wei; Brown, Roger L; Baumann, Linda J; Nitzke, Susan A
2008-05-01
This study examined the influence of weight management and education on five types of fat reduction behaviors mediated through three task-specific domains of self-efficacy among young, low-income obese African-American and white mothers. It also investigated interaction of race with the relationships between weight management, education, self-efficacy, and fat reduction behaviors. A sample of obese African-American and white mothers was recruited from the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) in Wisconsin. Participants reported their weight management status, education, self-efficacy for eating low-fat food, and fat reduction behaviors. For both racial groups, weight management status predicted low-fat food substitution and meat modification behaviors; education predicted meat modification behavior. Three task-specific domains of self-efficacy (negative mood, positive mood, and food availability) predicted different types of fat reduction behaviors and differed by race. Weight management influenced behaviors of low-fat food substitution, meat modification, and fried-food avoidance, mediated partially through self-efficacies of negative mood (African Americans), positive mood (African Americans, whites), and food availability (African Americans). Race affected the relationships between weight management, education, three task-specific domains of self-efficacy, and five types of fat reduction behaviors. Self-efficacies operated differentially for African Americans and whites. Thus, strategies to address specific fat reduction behaviors have the potential to be more effective when tailored to specific individual characteristics such as racial background, history of weight management strategies and task-specific domains of self-efficacy.
NASA Technical Reports Server (NTRS)
Cossey, Derek F.
1993-01-01
Future DOD, NASA, and SDI space systems will be larger than any spacecraft flown before. The economics of placing these Precision Space Systems (PSS) into orbit dictates that they be as low in mass as possible. This stringent weight reduction creates structural flexibility causing severe technical problems when combined with the precise shape and pointing requirements associated with many future PSS missions. Development of new Control Structure Interaction (CSI) technologies which can solve these problems and enable future space missions is being conducted at the Phillips Laboratory, On-Location Site, CA.
Vest, Amanda R
2018-06-01
Obesity is a strong risk factor for the development of heart failure (HF). Diet, exercise, and weight-loss pharmacotherapies have limited potential to achieve significant and sustainable weight loss, especially in patients with symptomatic systolic HF. This review seeks to determine the role of bariatric surgery for patients with systolic HF and obesity. Bariatric surgeries such as the laparoscopic sleeve gastrectomy (LSG) and Roux-en-Y gastric bypass (RYGB) represent the most successful long-term strategy for achieving weight loss and diabetes and hypertension remission in the general obese population. These benefits translate to reductions in cardiovascular events and mortality, as well as improvements in myocardial structure and function. There is also now data supporting the safety of LSG or RYGB in patients with systolic dysfunction and a reduction in HF admissions post-operatively. Current literature and clinical experience suggest that the most appropriate bariatric surgery candidates with HF are patients aged < 50-60 years, with severely depressed systolic function and NYHA II-III symptoms, who have failed non-surgical strategies and have a high likelihood of future cardiac transplantation candidacy after weight loss. This review seeks to determine the role of bariatric surgery for patients with systolic HF and obesity.
Himeno, Akihiro; Satoh-Asahara, Noriko; Usui, Takeshi; Wada, Hiromichi; Tochiya, Mayu; Kono, Shigeo; Yamada-Goto, Nobuko; Katsuura, Goro; Hasegawa, Koji; Nakao, Kazuwa; Shimatsu, Akira
2012-02-01
Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis can increase the risk of cardiovascular disease (CVD). However, the detailed relationships of HPA axis activity with weight reduction and CVD risk factors in obese patients have not been examined. This study was designed to elucidate the associations of salivary cortisol levels with weight reduction and CVD risk factors in obese patients. As a marker of HPA axis activity, we measured the morning salivary cortisol levels of 83 obese Japanese outpatients. We also examined metabolic parameters, inflammatory markers, and indicators of arterial stiffness, that is, the pulse wave velocity and cardio-ankle vascular index. All 83 obese patients underwent 3-month weight reduction therapy with lifestyle modification. At the baseline, multivariate regression analysis revealed that only logarithmic transformation of C-reactive protein (β = 0.258, P < .05) and cardio-ankle vascular index (β = 0.233, P < .05) were independent determinants of the salivary cortisol levels. However, other metabolic parameters were not significantly associated with the salivary cortisol levels. In addition, lower salivary cortisol levels and higher body weight at the baseline were the only independent determinants of successful weight loss through the weight reduction therapy (P < .01). The present study demonstrates that the baseline morning salivary cortisol levels are significantly associated with the levels of an inflammatory marker, arterial stiffness, and successful weight reduction in obese patients. Therefore, salivary cortisol could be a useful marker for assessing and managing body weight and CVD risk factors in obese patients. Copyright © 2012 Elsevier Inc. All rights reserved.
Taking weight-loss supplements may elicit liberation from dietary control. A laboratory experiment.
Chang, Yevvon Yi-Chi; Chiou, Wen-Bin
2014-01-01
Given that changes in diet and exercise habits are difficult to initiate and maintain, the use of weight-loss supplements has become an appealing alternative approach to weight management for many individuals. The current research examined whether the use of weight-loss supplements induced overly optimistic assessments of progress toward weight reduction, leading to psychological abdication of dietary regulation. Participants were randomly assigned to take either an identified placebo or a purported weight-loss supplement (actually the same placebo). Each participant reported perceived progress toward weight reduction following the manipulation. Consumption of snacks in a taste test and choice of sugary drinks were recorded. The results showed that participants receiving a purported supplement ate more in a taste task and preferred larger quantities of sugar in their reward drinks than did controls. Mediation analysis supported that the perception of progress toward weight reduction contributed to the liberating effect. Using weight-loss supplements may increase perceived progress toward weight reduction but decrease dietary self-regulation. These thought-provoking findings can serve as a basis for educating the public about the myth that they are free to feel liberated from the need to regulate their eating when using weight-loss supplements. Copyright © 2013 Elsevier Ltd. All rights reserved.
Damage-Tolerant Fan Casings for Jet Engines
NASA Technical Reports Server (NTRS)
2006-01-01
All turbofan engines work on the same principle. A large fan at the front of the engine draws air in. A portion of the air enters the compressor, but a greater portion passes on the outside of the engine this is called bypass air. The air that enters the compressor then passes through several stages of rotating fan blades that compress the air more, and then it passes into the combustor. In the combustor, fuel is injected into the airstream, and the fuel-air mixture is ignited. The hot gasses produced expand rapidly to the rear, and the engine reacts by moving forward. If there is a flaw in the system, such as an unexpected obstruction, the fan blade can break, spin off, and harm other engine components. Fan casings, therefore, need to be strong enough to contain errant blades and damage-tolerant to withstand the punishment of a loose blade-turned-projectile. NASA has spearheaded research into improving jet engine fan casings, ultimately discovering a cost-effective approach to manufacturing damage-tolerant fan cases that also boast significant weight reduction. In an aircraft, weight reduction translates directly into fuel burn savings, increased payload, and greater aircraft range. This technology increases safety and structural integrity; is an attractive, viable option for engine manufacturers, because of the low-cost manufacturing; and it is a practical alternative for customers, as it has the added cost saving benefits of the weight reduction.
Rector, R Scott; Loethen, Joanne; Ruebel, Meghan; Thomas, Tom R; Hinton, Pamela S
2009-10-01
Weight loss improves metabolic fitness and reduces morbidity and mortality; however, weight reduction also reduces bone mineral density (BMD) and increases bone turnover. Weight-bearing aerobic exercise may preserve bone mass and maintain normal bone turnover during weight reduction. We investigated the impact of weight-bearing and nonweight-bearing exercise on serum markers of bone formation and breakdown during short-term, modest weight loss in overweight premenopausal women. Subjects (n = 36) were assigned to 1 of 3 weight-loss interventions designed to produce a 5% reduction in body weight over 6 weeks: (i) energy restriction only (n = 11; DIET); (ii) energy restriction plus nonweight-bearing exercise (n = 12, CYCLE); or (iii) energy restriction plus weight-bearing exercise (n = 13, RUN). Bone turnover markers were measured in serum collected at baseline and after weight loss. All groups achieved a ~5% reduction in body weight (DIET = 5.2%; CYCLE = 5.0%; RUN = 4.7%). Osteocalcin (OC) and C-terminal telopeptide of type I collagen (CTX) increased with weight loss in all 3 groups (p < 0.05), whereas bone alkaline phosphatase was unaltered by the weight-loss interventions. At baseline, OC and CTX were positively correlated (r = 0.36, p = 0.03), but the strength of this association was diminished (r = 0.30, p = 0.06) after weight loss. Modest weight loss, regardless of method, resulted in a significant increase in both OC and CTX. Low-impact, weight-bearing exercise had no effect on serum markers of bone formation or resorption in premenopausal women during weight loss. Future studies that examine the effects of high-impact, weight-bearing activity on bone turnover and BMD during weight loss are warranted.
Mainz, Verena; Schulte-Rüther, Martin; Fink, Gereon R; Herpertz-Dahlmann, Beate; Konrad, Kerstin
2012-01-01
The neurobiological mechanisms of structural brain abnormalities in patients with anorexia nervosa (AN) remain poorly understood. In particular, little is known about the changes in and the recovery of gray matter (GM) volumes after weight gain and the relation to hormonal normalization in adolescent patients with AN. Nineteen female patients aged 12 to 17 years were assessed using magnetic resonance imaging at the time of admission to the hospital (T1) and after weight recovery (T2). Patients were compared with typically developing girls matched for age and intelligence quotient. Structural brain images were analyzed using a voxel-based morphometric approach. Circulating levels of cortisol and gonadotropins were assessed in blood samples. Compared with controls, patients with AN showed reduced GM in several brain regions along the cortical midline, reaching from the occipital cortex to the medial frontal areas. These GM reductions were mostly reversible at T1. Patients showed a GM increase from T1 to T2 along the cortical midline and in the occipital, temporal, parietal, and frontal lobes. GM increases at T2 correlated inversely with cortisol levels at T1 and positively with weight gain at T2. The strongest associations between regional GM increase and weight gain were found in the cerebellum. In addition, increases in GM volumes at T2 in the thalamus, hippocampus, and amygdala were associated with increases in follicle-stimulating hormone. Our data suggest that brain alterations in adolescents with acute AN are mostly reversible at T1 and that GM recovery in specific brain regions is associated with weight and hormonal normalization.
Souza, Elisa Sebba Tosta de; Crippa, José Alexandre de Souza; Pasian, Sonia Regina; Martinez, José Antônio Baddini
2010-01-01
To develop a new scale aimed at evaluating smoking motivation by incorporating questions and domains from the 68-item Wisconsin Inventory of Smoking Dependence Motives (WISDM-68) into the Modified Reasons for Smoking Scale (MRSS). Nine WISDM-68 questions regarding affiliative attachment, cue exposure/associative processes, and weight control were added to the 21 questions of the MRSS. The new scale, together with the Fagerström Test for Nicotine Dependence (FTND), was administered to 311 smokers (214 males; mean age = 37.6 ± 10.8 years; mean number of cigarettes smoked per day = 15.0 ± 9.2), who also provided additional information. We used exploratory factor analysis in order to determine the factor structure of the scale. The influence that certain clinical features had on the scores of the final factor solution was also analyzed. The factor analysis revealed a 21-question solution grouped into nine factors: addiction, pleasure from smoking, tension reduction, stimulation, automatism, handling, social smoking, weight control, and affiliative attachment. For the overall scale, the Cronbach's alpha coefficient was 0.83. Females scored significantly higher for addiction, tension reduction, handling, weight control, and affiliative attachment than did males. The FTND score correlated positively with addiction, tension reduction, stimulation, automatism, social smoking, and affiliative attachment. The number of cigarettes smoked per day was associated with addiction, tension reduction, stimulation, automatism, affiliative attachment, and handling. The level of exhaled CO correlated positively with addiction, automatism, and affiliative attachment. The new scale provides an acceptable framework of motivational factors for smoking, with satisfactory psychometric properties and reliability.
Schippers, M; Adam, P C G; Smolenski, D J; Wong, H T H; de Wit, J B F
2017-04-01
Weight loss interventions are delivered through various mediums including, increasingly, mobile phones. This systematic review and meta-analysis assesses whether interventions delivered via mobile phones reduce body weight and which intervention characteristics are associated with efficacy. The study included randomised controlled trials assessing the efficacy of weight loss interventions delivered via mobile phones. A meta-analysis to test intervention efficacy was performed, and subgroup analyses were conducted to determine whether interventions' delivery mode(s), inclusion of personal contact, duration and interaction frequency improve efficacy. Pooled body weight reduction (d = -0.23; 95% confidence interval = -0.38, -0.08) was significant. Interventions delivered via other modes in addition to the mobile phone were associated with weight reduction. Personal contact and more frequent interactions in interventions were also associated with greater weight reduction. In conclusion, the current body of evidence shows that interventions delivered via mobile phones produce a modest reduction in body weight when combined with other delivery modes. Delivering interventions with frequent and personal interactions may in particular benefit weight loss results. © 2017 World Obesity Federation.
Supersonic Wing Optimization Using SpaRibs
NASA Technical Reports Server (NTRS)
Locatelli, David; Mulani, Sameer B.; Liu, Qiang; Tamijani, Ali Y.; Kapania, Rakesh K.
2014-01-01
This research investigates the advantages of using curvilinear spars and ribs, termed SpaRibs, to design a supersonic aircraft wing-box in comparison to the use of classic design concepts that employ straight spars and ribs. The objective is to achieve a more efficient load-bearing mechanism and to passively control the deformation of the structure under the flight loads. Moreover, the use of SpaRibs broadens the design space and allows for natural frequencies and natural mode shape tailoring. The SpaRibs concept is implemented in a new optimization MATLAB-based framework referred to as EBF3SSWingOpt. This optimization scheme performs both the sizing and the shaping of the internal structural elements, connecting the optimizer with the analysis software. The shape of the SpaRibs is parametrically defined using the so called Linked Shape method. Each set of SpaRibs is placed in a one by one square domain of the natural space. The set of curves is subsequently transformed in the physical space for creating the wing structure geometry layout. The shape of each curve of each set is unique; however, mathematical relations link the curvature in an effort to reduce the number of design variables. The internal structure of a High Speed Commercial Transport aircraft concept developed by Boeing is optimized subjected to stress, subsonic flutter and supersonic flutter constraints. The results show that the use of the SpaRibs allows for the reduction of the aircraft's primary structure weight without violating the constraints. A weight reduction of about 15 percent is observed.
Park, S-K; Lee, T; Yang, H-J; Park, J H; Sohn, C I; Ryu, S; Park, D I
2017-05-01
General obesity and abdominal obesity is an established risk factor of gastroesophageal reflux disease (GERD). However, the influence of weight or waist change on improvement of GERD is unclear. Our aim was to investigate if weight loss or waist reduction improves GERD symptoms and esophagitis. A retrospective longitudinal study of 15 295 subjects who underwent gastroscopy for a health checkup and reported GERD symptoms between 2011 and 2013, and repeated a checkup until 2014 was conducted. The improvement of GERD symptoms and esophagitis according to weight loss (≥-2, -0.5 to -2 kg/m 2 in body mass index [BMI]), waist reduction (≥-5, -0.1 to -0.5 cm) and baseline BMI/waist circumference (WC) categories was assessed using logistic regression. Weight loss or waist reduction was associated with improvement in GERD symptoms only in subjects with general or abdominal obesity. Among subjects with general obesity (BMI ≥25 kg/m 2 ) and decreased ≥2 kg/m 2 in BMI, the adjusted odds ratio (OR) of improvement in GERD symptoms was 2.34 (95% confidence interval [CI] 1.70-2.83). Among subjects with abdominal obesity (WC ≥90 cm) and decreased ≥5 cm in WC, the corresponding OR was 2.16 (95% CI 1.56-2.90). There was no association between weight loss or waist reduction and improvement in esophagitis. Weight loss or waist reduction was associated with improvement in GERD symptoms only in subjects with general or abdominal obesity. Weight loss or waist reduction will be an important treatment option in obese patients. © 2016 John Wiley & Sons Ltd.
The food and weight combat. A problematic fight for the elite combat sports athlete.
Pettersson, Stefan; Pipping Ekström, Marianne; Berg, Christina M
2012-10-01
Weight reduction in athletes is motivated by optimisation of performance, aesthetic reasons or to achieve a pre-designated weight. Previous research has shown that dietary restraint and short term weight regulation frequently takes place among combat sports athletes such as wrestlers and judokas. The aim of this study was to explore negative experiences related to dietary strategies and weight-making practises used by elite combat sports athletes. Using semi-structured interviews, 14 Swedish national team athletes in wrestling, judo and taekwondo were asked about their dietary intake and their engagement in both long- and short-term weight regulation practises. Content analysis of the transcribed interviews, display a constant struggle regarding nutritional standpoints. Sport demands such as achieving an optimal weight and nutritional intake were considered as central in order for excellent performance. Adhering to these demands was found to be problematic however, primarily because of; (1) negative physiological responses and (2) opposing ideals of a non-sport related nature, such as the importance of the athletes to be healthy and social in their everyday lives. Copyright © 2012 Elsevier Ltd. All rights reserved.
Seasonal carcass composition and energy balance of female black ducks in Maine
Reinecke, K.J.; Stone, T.L.; Owen, R.B.
1982-01-01
Female Black Ducks (Anas rubripes) collected in Maine during the summer, fall, and winter of 1974-1976 showed significant seasonal variation in body weight, nonfat dry weight, gizzard and pectoral muscle weight, and fat, moisture, and protein content. Variation of body weight within and among seasons was correlated more strongly with carcass protein content, and with fat content during seasons of heavy lipid deposition, than with three structural size variables (culmen, tarsus, and sternum). Regression equations including fat and protein as independent variables accounted for 80-90% of the annual and seasonal variation in body weight; structural size variables alone accounted for less than 30%. Immature females averaged 54 and 99 g lighter, and carried 54 and 59 g less fat than adults during the fall and winter. Ducks of both age classes lost weight in December and January. Adult and immature females metabolized 59 and 64 g of fat and 17 and 25 g of protein in winter compared with 46 g of fat during the nesting season. Nutrient reserves are thus equally as important for the winter survival of these birds as for successfurl eproduction. Seasonal changes in carcass composition suggest that (1) fat deposited in late fall provides an energy reserve during winter, (2) a reduction in lean weight during winter may lower daily energy requirements and increase the effective amount of energy reserves, and (3) declining body weights during late winter may be an endogenous rhythm that reflects a shift in the expected benefits of an energy reserve compared to the costs of carrying additional weight,
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wenzel, Tom P.
This report recalculates the estimated relationship between vehicle mass and societal fatality risk, using alternative groupings by vehicle weight, to test whether the trend of decreasing fatality risk from mass reduction as case vehicle mass increases, holds over smaller increments of the range in case vehicle masses. The NHTSA baseline regression model estimates the relationship using for two weight groups for cars and light trucks; we re-estimated the mass reduction coefficients using four, six, and eight bins of vehicle mass. The estimated effect of mass reduction on societal fatality risk was not consistent over the range in vehicle masses inmore » these weight bins. These results suggest that the relationship indicated by the NHTSA baseline model is a result of other, unmeasured attributes of the mix of vehicles in the lighter vs. heavier weight bins, and not necessarily the result of a correlation between mass reduction and societal fatality risk. An analysis of the average vehicle, driver, and crash characteristics across the various weight groupings did not reveal any strong trends that might explain the lack of a consistent trend of decreasing fatality risk from mass reduction in heavier vehicles.« less
Jansen, Aina; Lyche, Jan L; Polder, Anuschka; Aaseth, Jan; Skaug, Marit Aralt
2017-01-01
Lipophilic persistent organic pollutants (POP) are stored in adipose tissue. Following rapid weight loss such as when induced by bariatric surgery, an increased release of potential harmful lipophilic compounds into the blood circulation may occur. Weight reduction is recommended for overweight and obese individuals in order to decrease risk of weight-related health problems. However, in cases of significant weight reduction POP become mobilized chemicals and consequently may adversely affect health, including endocrine disruption. The objective of the present investigation was to estimate quantitatively the level of mobilization of POP following weight loss over time. According to literature search criteria, 17 studies were identified with 2061 participants. Data from 5 of the studies with 270 participants were used to assess the change in blood levels of POP in percent per kilogram weight loss. Weight loss in the included studies varied from 4.4 to 64.8 kg. In all studies, the majority of POP concentrations in blood were found to rise following weight reduction. Blood concentrations following weight reduction were elevated by 2-4% per kilogram weight loss for most POP examined. The increased POP levels were still elevated 12 mo after intervention. Most research in this field, including animal studies, is carried out on a single compound or group of selected compounds, not taking the "cocktail effect" into consideration. This does not reflect the true range of POP to which humans are actually exposed. Few chronic investigations have been published and, in particular, few studies were available that compared the increase in POP concentrations with clinical consequences as individuals lost weight. These limitations call for caution in interpreting results. The benefits of losing weight still far outweigh the potential adverse health risks. However, further studies are recommended to determine the clinical significance of increased blood levels of POPs following rapid and excessive weight loss, particularly for women attending weight reduction treatment before pregnancy.
Spear, John R.; Figueroa, Linda A.; Honeyman, Bruce D.
2000-01-01
The kinetics for the reduction of sulfate alone and for concurrent uranium [U(VI)] and sulfate reduction, by mixed and pure cultures of sulfate-reducing bacteria (SRB) at 21 ± 3°C were studied. The mixed culture contained the SRB Desulfovibrio vulgaris along with a Clostridium sp. determined via 16S ribosomal DNA analysis. The pure culture was Desulfovibrio desulfuricans (ATCC 7757). A zero-order model best fit the data for the reduction of sulfate from 0.1 to 10 mM. A lag time occurred below cell concentrations of 0.1 mg (dry weight) of cells/ml. For the mixed culture, average values for the maximum specific reaction rate, Vmax, ranged from 2.4 ± 0.2 μmol of sulfate/mg (dry weight) of SRB · h−1) at 0.25 mM sulfate to 5.0 ± 1.1 μmol of sulfate/mg (dry weight) of SRB · h−1 at 10 mM sulfate (average cell concentration, 0.52 mg [dry weight]/ml). For the pure culture, Vmax was 1.6 ± 0.2 μmol of sulfate/mg (dry weight) of SRB · h−1 at 1 mM sulfate (0.29 mg [dry weight] of cells/ml). When both electron acceptors were present, sulfate reduction remained zero order for both cultures, while uranium reduction was first order, with rate constants of 0.071 ± 0.003 mg (dry weight) of cells/ml · min−1 for the mixed culture and 0.137 ± 0.016 mg (dry weight) of cells/ml · min−1 (U0 = 1 mM) for the D. desulfuricans culture. Both cultures exhibited a faster rate of uranium reduction in the presence of sulfate and no lag time until the onset of U reduction in contrast to U alone. This kinetics information can be used to design an SRB-dominated biotreatment scheme for the removal of U(VI) from an aqueous source. PMID:10966381
Kim, Bokun; Tsujimoto, Takehiko; So, Rina; Zhao, Xiaoguang; Oh, Sechang; Tanaka, Kiyoji
2017-12-31
To date, there have been no reports on whether weight reduction causes decreases in muscle mass, muscle strength, or physical performance that could lead to health problems. Thus, in this pilot study, we investigated the appropriateness of the changes in muscle mass, muscle strength and physical performance after weight reduction. Obese men who completed a weight reduction program to decrease and maintain a body mass index (BMI) of less than 25 kg/m2 for one year were recruited for the study. One year after the completion of a weight reduction program, the participants' muscle mass, muscle strength, and physical performance were compared with those in a reference group composed of individuals whose BMI was less than 25 kg/m2. Whole-body scanning was performed using dual-energy X-ray absorptiometry to analyze muscle mass. Handgrip strength and knee extensor strength were measured to evaluate arm and leg muscle strength, respectively. For physical performance, a jump test was employed. The results showed that the biceps, triceps, subscapular, and suprailiac areas of professional fashion models were significantly thinner than those of women in general (p<.001), and that their waist size was also significantly smaller (p<.001). However, hip circumference showed no significant difference. Body mass index, waist-to-hip ratio, and body fat (%) in professional fashion models were significantly lower than those in women in general (p<.001), while the body density in professional fashion models was significantly greater (p<0.001). Weight reduction participants showed an average reduction in body weight of -16.47%. Normalized arm muscle mass and handgrip strength were significantly greater in the weight reduction group than in the reference group; however, no significant differences were detected between the two groups with respect to the other variables. After one year, there were no significant differences between the two groups. ©2017 The Korean Society for Exercise Nutrition
Ziebell, Angela; Gjersing, Erica; Hinchee, Maud; ...
2016-01-20
Lignin reduction through breeding and genetic modification has the potential to reduce costs in biomass processing in pulp and paper, forage, and lignocellulosic ethanol industries. Here, we present detailed characterization of the extractability and lignin structure of Eucalyptus urophylla x Eucalyptus grandis RNAi downregulated in p-coumaroyl quinate/shikimate 3'-hydroxylase (C3'H) or cinnamate-4-hydroxylase (C4H). Both the C3'H and C4H downregulated lines were found to have significantly higher extractability when exposed to NaOH base extraction, indicating altered cell wall construction. The molecular weight of isolated lignin was measured and lignin structure was determined by HSQC NMR-based lignin subunit analysis for control and themore » C3'H and C4H downregulated lines. The slight reductions in average molecular weights of the lignin isolated from the transgenic lines (C3'H = 7000, C4H = 6500, control = 7300) does not appear to explain the difference in extractability. The HSQC NMR-based lignin subunit analysis showed increases in H lignin content for the C3'H but only slight differences in the lignin subunit structure of the C3'H and C4H downregulated lines when compared to the control. The greatest difference between the C3'H and C4H downregulated lines is the total lignin content; therefore, it appears that overall lowered lignin content contributes greatly to reduced recalcitrance and increased extractability of cell wall biopolymers. Furthermore, studies will be conducted to determine how the reduction in lignin content creates a less rigid cell wall that is more prone to extraction and sugar release.« less
Dahlqvist, Sofia; Ahlén, Elsa; Filipsson, Karin; Gustafsson, Thomas; Hirsch, Irl B; Tuomilehto, Jaakko; Imberg, Henrik; Ahrén, Bo; Attvall, Stig; Lind, Marcus
2018-01-01
To evaluate variables associated with hemoglobin A1c (HbA1c) and weight reduction when adding liraglutide to persons with type 2 diabetes treated with multiple daily insulin injections (MDI). This was a reanalysis of a previous trial where 124 patients were enrolled in a double-blind, placebo-controlled, multicenter randomized trial carried out over 24 weeks. Predictors for effect on change in HbA1c and weight were analyzed within the treatment group and with concurrent interaction analyses. Correlation analyses for change in HbA1c and weight from baseline to week 24 were made. The mean age at baseline was 63.7 years, 64.8% were men, the mean number of insulin injections was 4.4 per day, the mean daily insulin dose was 105 units and the mean HbA1c was 74.5 mmol/mol (9.0%). The mean HbA1c and weight reductions were 12.3 mmol/mol (1.13%; P<0.001) and 3.8 kg (P<0.001) greater in liraglutide than placebo-treated persons. There was no significant predictor for greater effect on HbA1c that existed in all analyses (univariate, multivariate and interaction analyses against controls). For a greater weight reduction when adding liraglutide, a lower HbA1c level at baseline was a predictor (liraglutide group P=0.002, P=0.020 for liraglutide group vs placebo). During follow-up in the liraglutide group, no significant correlation was found between change in weight and change in HbA1c (r=0.09, P=0.46), whereas a correlation existed between weight and insulin dose reduction (r=0.44, P<0.001). Weight reduction becomes greater when adding liraglutide in patients with type 2 diabetes treated with MDI who had a lower HbA1c level compared with those with a higher HbA1c level. There was no correlation between reductions in HbA1c and weight when liraglutide was added, that is, different patient groups responded with HbA1c and weight reductions. EudraCT nr: 2012-001941-42.
Stefanidis, Aneta; Man Lee, Christine Cheuk; Brown, Wendy A; Oldfield, Brian J
2017-02-01
The laparoscopic adjustable gastric band (AGB) has been effective in reducing excess weight by approximately 50% for at least 16 years. However, as with all weight loss approaches, reduction in weight resulting from bariatric surgery is associated with a compensatory reduction in energy expenditure, which may confound and limit weight loss. Adjuvant therapies that reduce food intake and increase energy expenditure may be used to improve weight loss outcomes by ameliorating, or even reversing, this reduction in energy expenditure. Rats were either fitted with an AGB or were sham operated and received one of 2 adjunctive pharmacologic treatments, (1) thyroxine or (2) bupropion/naltrexone (Contrave), at a range of doses and matched with vehicle controls (n = 6-8/group) over a 4-week period of combined treatments. Metabolic parameters including food intake, weight, fat mass, and energy expenditure in brown adipose tissue (BAT), whole body calorimetry, and physical activity were assessed. Inflation of the AGB caused a reduction in weight gain that was further enhanced by cotreatment with either thyroxine or Contrave (P<.05). Thyroxine completely ameliorated the reduction in AGB-induced BAT thermogenesis and significantly improved weight loss, particularly in fat mass. Contrave also augmented the loss of weight and fat mass associated with the AGB and increased BAT thermogenesis in banded rats even at doses below that required to change food intake. Adjuvant therapies can improve the efficacy of the AGB, at least in part by negating the compensatory reduction in energy expenditure, but also via a combined effect on food intake. Copyright © 2017 American Society for Bariatric Surgery. All rights reserved.
Design of a mechanical system in gait rehabilitation with progressive addition of weight
NASA Astrophysics Data System (ADS)
Braidot, Ariel A. A.; Aleman, Guillermo L.
2011-12-01
In this paper we designed and developed a mechanical device for gait rehabilitation based on the application of "partial body weight reduction therapy". An evaluation of the characteristics of devices based on this therapy currently available on the market was carried out obtaining information of the different mechanisms used in it. The device was designed to adapt to different height and weight of patients and to be used with additional equipment in gait rehabilitation, for example, treadmills, elliptical trainers and vertical scalers. It was envisaged to be used by patients with asymmetry in the lower extremities capabilities. We developed a stable structure in steel ASTM A36 which does not depend on the building conditions of the installation site. RamAdvanse software was used to calculate structural stability. A winch with automatic brake mechanism was used to raise/lower the patient, who was tied to a comfortable harness which provided safety to the patient and therapist. It was possible to quantify precisely, using counterweights, the weight borne by the patient during therapy. We obtained a small-sized and ergonomic low-cost prototype, with similar features to those currently considered cutting-edge devices.
Mercury photolytic transformation affected by low-molecular-weight natural organics in water.
He, Feng; Zheng, Wang; Liang, Liyuan; Gu, Baohua
2012-02-01
Mechanisms by which dissolved organic matter (DOM) mediates the photochemical reduction of Hg(II) in aquatic ecosystems are not fully understood, owing to the heterogeneous nature and complex structural properties of DOM. In this work, naturally occurring aromatic compounds including salicylic, 4-hydrobenzoic, anthranilic, 4-aminobenzoic, and phthalic acid were systematically studied as surrogates for DOM in order to gain an improved mechanistic understanding of these compounds in the photoreduction of Hg(II) in water. We show that the photoreduction rates of Hg(II) are influenced not only by the substituent functional groups such as -OH, -NH(2) and -COOH on the benzene ring, but also the positioning of these functional groups on the ring structure. The Hg(II) photoreduction rate decreases in the order anthranilic acid>salicylic acid>phthalic acid according to the presence of the -NH(2), -OH, -COOH functional groups on benzoic acid. The substitution position of the functional groups affects reduction rates in the order anthranilic acid>4-aminobenzoic acid and salicylic acid>4-hydroxybenzoic acid. Reduction rates correlate strongly with ultraviolet (UV) absorption of these compounds and their concentrations, suggesting that the formation of organic free radicals during photolysis of these compounds is responsible for Hg(II) photoreduction. These results provide insight into the role of low-molecular-weight organic compounds and possibly DOM in Hg photoredox transformation and may thus have important implications for understanding Hg geochemical cycling in the environment. Copyright © 2011 Elsevier B.V. All rights reserved.
Li, Mi; Cao, Shilin; Meng, Xianzhi; Studer, Michael; Wyman, Charles E; Ragauskas, Arthur J; Pu, Yunqiao
2017-01-01
Hydrothermal pretreatment using liquid hot water (LHW) is capable of substantially reducing the cell wall recalcitrance of lignocellulosic biomass. It enhances the saccharification of polysaccharides, particularly cellulose, into glucose with relatively low capital required. Due to the close association with biomass recalcitrance, the structural change of the components of lignocellulosic materials during the pretreatment is crucial to understand pretreatment chemistry and advance the bio-economy. Although the LHW pretreatment has been extensively applied and studied, the molecular structural alteration during pretreatment and its significance to reduced recalcitrance have not been well understood. We investigated the effects of LHW pretreatment with different severity factors (log R 0 ) on the structural changes of fast-grown poplar ( Populus trichocarpa ). With the severity factor ranging from 3.6 to 4.2, LHW pretreatment resulted in a substantial xylan solubilization by 50-77% ( w/w , dry matter). The molecular weights of the remained hemicellulose in pretreated solids also have been significantly reduced by 63-75% corresponding to LHW severity factor from 3.6 to 4.2. In addition, LHW had a considerable impact on the cellulose structure. The cellulose crystallinity increased 6-9%, whereas its degree of polymerization decreased 35-65% after pretreatment. We found that the pretreatment severity had an empirical linear correlation with the xylan solubilization ( R 2 = 0.98, r = + 0.99), hemicellulose molecular weight reduction ( R 2 = 0.97, r = - 0.96 and R 2 = 0.93, r = - 0.98 for number-average and weight-average degree of polymerization, respectively), and cellulose crystallinity index increase ( R 2 = 0.98, r = + 0.99). The LHW pretreatment also resulted in small changes in lignin structure such as decrease of β- O -4' ether linkages and removal of cinnamyl alcohol end group and acetyl group, while the S/G ratio of lignin in LHW pretreated poplar residue remained no significant change compared with the untreated poplar. This study revealed that the solubilization of xylan, the reduction of hemicellulose molecular weights and cellulose degree of polymerization, and the cleavage of alkyl-aryl ether bonds in lignin resulted from LHW pretreatment are critical factors associated with reduced cell wall recalcitrance. The chemical-structural changes of the three major components, cellulose, lignin, and hemicellulose, during LHW pretreatment provide useful and fundamental information of factors governing feedstock recalcitrance during hydrothermal pretreatment.
Weight Reduction Potential of Automobiles and Light Trucks: 1980 Summary Source Document
DOT National Transportation Integrated Search
1981-06-01
This report provides an assessment of the potential of weight reduction for passenger cars and light trucks (including pickup trucks, vans, and utility vehicles of GVWR up to 8500 pounds) in the post-1985 period. Vehicle characteristics and weight re...
Tomaiuolo, F; Carlesimo, G; Di, P; Petrides, M; Fera, F; Bonanni, R; Formisano, R; Pasqualetti, P; Caltagirone, C
2004-01-01
Objective: The gross morphology and morphometry of the hippocampus, fornix, and corpus callosum in patients with severe non-missile traumatic brain injury (nmTBI) without obvious neuroradiological lesions was examined and the volumes of these structures were correlated with performance on memory tests. In addition, the predictability of the length of coma from the selected anatomical volumes was examined. Method: High spatial resolution T1 weighted MRI scans of the brain (1 mm3) and neuropsychological evaluations with standardised tests were performed at least 3 months after trauma in 19 patients. Results: In comparison with control subjects matched in terms of gender and age, volume reduction in the hippocampus, fornix, and corpus callosum of the nmTBI patients was quantitatively significant. The length of coma correlated with the volume reduction in the corpus callosum. Immediate free recall of word lists correlated with the volume of the fornix and the corpus callosum. Delayed recall of word lists and immediate recall of the Rey figure both correlated with the volume of the fornix. Delayed recall of the Rey figure correlated with the volume of the fornix and the right hippocampus. Conclusion: These findings demonstrate that in severe nmTBI without obvious neuroradiological lesions there is a clear hippocampal, fornix, and callosal volume reduction. The length of coma predicts the callosal volume reduction, which could be considered a marker of the severity of axonal loss. A few memory test scores correlated with the volumes of the selected anatomical structures. This relationship with memory performance may reflect the diffuse nature of the damage, leading to the disruption of neural circuits at multiple levels and the progressive neural degeneration occurring in TBI. PMID:15314123
Chin, Sang Ouk; Keum, Changwon; Woo, Junghoon; Park, Jehwan; Choi, Hyung Jin; Woo, Jeong-Taek; Rhee, Sang Youl
2016-11-07
A discrepancy exists with regard to the effect of smartphone applications (apps) on weight reduction due to the several limitations of previous studies. This is a retrospective cohort study, aimed to investigate the effectiveness of a smartphone app on weight reduction in obese or overweight individuals, based on the complete enumeration study that utilized the clinical and logging data entered by Noom Coach app users between October 2012 and April 2014. A total of 35,921 participants were included in the analysis, of whom 77.9% reported a decrease in body weight while they were using the app (median 267 days; interquartile range = 182). Dinner input frequency was the most important factor for successful weight loss (OR = 10.69; 95% CI = 6.20-19.53; p < 0.001), and more frequent input of weight significantly decreased the possibility of experiencing the yo-yo effect (OR = 0.59, 95% CI = 0.39-0.89; p < 0.001). This study demonstrated the clinical utility of an app for successful weight reduction in the majority of the app users; the effects were more significant for individuals who monitored their weight and diet more frequently.
NASA Technical Reports Server (NTRS)
Stephens, Craig A.
2009-01-01
NASA HYP M&S is pursuing the development of SITPS: 1) Working with HYP MDAO to formulate methodology to incorporate SITPS into hypersonic vehicle design trades. 2) SITPS-0 to SITPS-1 (FY10): a) Manufacturing development and weight reduction (5.8 to 3.1 lb(sub m)/sq ft); b) Structural testing to mature SITPS model. 3) SITPS-2 (FY11): a) Focus on panel closeout, panel-to-panel load transfer, and panel curvature. 4) Extend fabrication technology to include alternate cores and insulations (FY12).
Willardson, Jeffrey M; Simão, Roberto; Fontana, Fabio E
2012-11-01
The purpose of this study was to compare 4 different loading schemes for the free weight bench press, wide grip front lat pull-down, and free weight back squat to determine the extent of progressive load reductions necessary to maintain repetition performance. Thirty-two recreationally trained women (age = 29.34 ± 4.58 years, body mass = 59.61 ± 4.72 kg, height = 162.06 ± 4.04 cm) performed 4 resistance exercise sessions that involved 3 sets of the free weight bench press, wide grip front lat pull-down, and free weight back squat, performed in this exercise order during all 4 sessions. Each of the 4 sessions was conducted under different randomly ordered loading schemes, including (a) a constant 10 repetition maximum (RM) load for all 3 sets and for all 3 exercises, (b) a 5% reduction after the first and second sets for all the 3 exercises, (c) a 10% reduction after the first and second sets for all the 3 exercises, and (d) a 15% reduction after the first and second sets for all the 3 exercises. The results indicated that for the wide grip front lat pull-down and free weight back squat, a 10% load reduction was necessary after the first and second sets to accomplish 10 repetitions on all the 3 sets. For the free weight bench press, a load reduction between 10 and 15% was necessary; specifically, a 10% reduction was insufficient and a 15% reduction was excessive, as evidenced by significantly >10 repetitions on the second and third sets for this exercise (p ≤ 0.05). In conclusion, the results of this study indicate that a resistance training prescription that involves 1-minute rest intervals between multiple 10RM sets does require load reductions to maintain repetition performance. Practitioners might apply these results by considering an approximate 10% load reduction after the first and second sets for the exercises examined, when training women of similar characteristics as in this study.
Skariyachan, Sinosh; Manjunatha, Vishal; Sultana, Subiya; Jois, Chandana; Bai, Vidya; Vasist, Kiran S
2016-09-01
This study aimed to formulate novel microbial consortia isolated from plastic garbage processing areas and thereby devise an eco-friendly approach for enhanced degradation of low-density polyethylene (LDPE). The LDPE degrading bacteria were screened and microbiologically characterized. The best isolates were formulated as bacterial consortia, and degradation efficiency was compared with the consortia formulated using known isolates obtained from the Microbial Culture Collection Centre (MTCC). The degradation products were analyzed by FTIR, GC-FID, tensile strength, and SEM. The bacterial consortia were characterized by 16S ribosomal DNA (rDNA) sequencing. The formulated bacterial consortia demonstrated 81 ± 4 and 38 ± 3 % of weight reduction for LDPE strips and LDPE pellets, respectively, over a period of 120 days. However, the consortia formulated by MTCC strains demonstrated 49 ± 4 and 20 ± 2 % of weight reduction for LDPE strips and pellets, respectively, for the same period. Furthermore, the three isolates in its individual application exhibited 70 ± 4, 68 ± 4, and 64 ± 4 % weight reduction for LDPE strips and 21 ± 2, 28 ± 2, 24 ± 2 % weight reduction for LDPE pellets over a period of 120 days (p < 0.05). The end product analysis showed structural changes and formation of bacterial film on degraded LDPE strips. The 16S rDNA characterization of bacterial consortia revealed that these organisms were novel strains and designated as Enterobacter sp. bengaluru-btdsce01, Enterobacter sp. bengaluru-btdsce02, and Pantoea sp. bengaluru-btdsce03. The current study thus suggests that industrial scale-up of these microbial consortia probably provides better insights for waste management of LDPE and similar types of plastic garbage.
Feasibility of magnetic bearings for advanced gas turbine engines
NASA Technical Reports Server (NTRS)
Hibner, David; Rosado, Lewis
1992-01-01
The application of active magnetic bearings to advanced gas turbine engines will provide a product with major improvements compared to current oil lubricated bearing designs. A rethinking of the engine rotating and static structure design is necessary and will provide the designer with significantly more freedom to meet the demanding goals of improved performance, increased durability, higher reliability, and increased thrust to weight ratio via engine weight reduction. The product specific technology necessary for this high speed, high temperature, dynamically complex application has been defined. The resulting benefits from this approach to aircraft engine rotor support and the complementary engine changes and improvements have been assessed.
Potential for Automobile Weight Reduction Outlook as of 1975-1976
DOT National Transportation Integrated Search
1978-08-01
A study has been carried out to evaluate the potential for weight reduction of automobiles. It is concluded that automobiles of lighter weight than those current (1976 models) in the domestic market may be built in each of three size classes, 4, 5, a...
Chokradjaroen, Chayanaphat; Rujiravanit, Ratana; Watthanaphanit, Anyarat; Theeramunkong, Sewan; Saito, Nagahiro; Yamashita, Kazuko; Arakawa, Ryuichi
2017-07-01
Solution plasma (SP) treatment in combination with oxidizing agents, i.e., hydrogen peroxide (H 2 O 2 ), potassium persulfate (K 2 S 2 O 8 ) and sodium nitrite (NaNO 2 ) were adopted to chitosan degradation in order to achieve fast degradation rate, low chemicals used and high yield of low-molecular-weight chitosan and chitooligosaccharide (COS). Among the studied oxidizing agents, H 2 O 2 was found to be the best choice in terms of appreciable molecular weight reduction without major change in chemical structure of the degraded products of chitosan. By the combination with SP treatment, dilute solution of H 2 O 2 (4-60mM) was required for effective degradation of chitosan. The combination of SP treatment and dilute solution of H 2 O 2 (60mM) resulted in the great reduction of molecular weight of chitosan and water-soluble chitosan was obtained as a major product. The resulting water-soluble chitosan was precipitated to obtain COS. An inhibitory effect against cervical cancer cell line (HeLa cells) of COS was also examined. Copyright © 2017 Elsevier Ltd. All rights reserved.
NASA Astrophysics Data System (ADS)
Beck, A. J.; Hodzic, A.; Soutis, C.; Wilson, C. W.
2011-12-01
Computer-based Life Cycle Analysis (LCA) models were carried out to compare lightweight composites with the traditional aluminium over their useful lifetime. The analysis included raw materials, production, useful life in operation and disposal at the end of the material's useful life. The carbon fibre epoxy resin composite could in some cases reduce the weight of a component by up to 40 % compared to aluminium. As the fuel consumption of an aircraft is strongly influenced by its total weight, the emissions can be significantly reduced by increasing the proportion of composites used in the aircraft structure. Higher emissions, compared to aluminium, produced during composites production meet their 'break even' point after certain number of time units when used in aircraft structures, and continue to save emissions over their long-term operation. The study highlighted the environmental benefits of using lightweight structures in aircraft design, and also showed that utilisation of composites in products without energy saving may lead to increased emissions in the environment.
Longin, Rita; Grasse, Marina; Aspalter, Rosa; Waldherr, Karin
2012-01-01
Preliminary results indicated effectiveness of the online weight reduction program KiloCoach. The current study presents a large collection of user data and compares KiloCoach with other evaluated commercial weight loss programs. Furthermore, potential factors influencing the effectiveness of internet weight loss programs should be identified. 4,310 data sets of KiloCoach users were available, 3,150 of them were suitable for further analysis. 946 program users were considered completers (at least 60 days of continuous protocol). For comparison with other programs, different subsamples were drawn that matched to the inclusion criteria of reference studies. On average, KiloCoach overweight and obese completers lost 4.5 % of initial body weight. KiloCoach was as effective as the commercial program Weight Watchers® after 1 year (6.4% vs. 5.3% weight loss; p = 0.11) and 2 years (5.1% vs. 3.2% weight loss; p = 0.15). KiloCoach proved to be more effective than other online programs (Viktklubb, eDiets.com) as well as an in-person behavioral program, but less effective than Vtrim®, an online behavioral program providing intensive support. In comparison to reference programs, KiloCoach proved to be effective for weight reduction. The effect of online weight reduction programs seems to depend on methods and features applied.
High-Temperature Polymer Composites Tested for Hypersonic Rocket Combustor Backup Structure
NASA Technical Reports Server (NTRS)
Sutter, James K.; Shin, E. Eugene; Thesken, John C.; Fink, Jeffrey E.
2005-01-01
Significant component weight reductions are required to achieve the aggressive thrust-toweight goals for the Rocket Based Combined Cycle (RBCC) third-generation, reusable liquid propellant rocket engine, which is one possible engine for a future single-stage-toorbit vehicle. A collaboration between the NASA Glenn Research Center and Boeing Rocketdyne was formed under the Higher Operating Temperature Propulsion Components (HOTPC) program and, currently, the Ultra-Efficient Engine Technology (UEET) Project to develop carbon-fiber-reinforced high-temperature polymer matrix composites (HTPMCs). This program focused primarily on the combustor backup structure to replace all metallic support components with a much lighter polymer-matrixcomposite- (PMC-) titanium honeycomb sandwich structure.
NASA Astrophysics Data System (ADS)
Mundra, Manish K.
2005-03-01
It is well known that the glass transition temperatures, Tgs, of supported polystyrene (PS) films decrease dramatically with decreasing film thickness below 60-80 nm. However, a detailed understanding of the cause of this effect is lacking. We have investigated the impact of several parameters, including polymer molecular weight (MW), repeat unit structure, and the length scale of cooperatively rearranging regions in bulk. There is no significant effect of PS MW on the Tg-confinement effect over a range of 5,000 to 3,000,000 g/mol. In contrast, the strength of the Tg reduction and the onset of the confinement effect increase dramatically upon changing the polymer from PS to poly(4-tert-butylstyrene) (PTBS), with PTBS exhibiting a Tg reduction relative to bulk at a thickness of 300-400 nm. PTBS also shows a Tg reduction relative to bulk of 47 K in a 21-nm-thick film, more than twice that observed in a PS film of identical thickness. Characterization of the length scale of cooperatively rearranging regions has been done by differential scanning calorimetry but reveals at best a limited correlation with the confinement effect.
"Structure-size me:" weight and health changes in a four week residential program.
Shapiro, Jennifer R; Stout, Anna L; Musante, Gerard J
2006-08-01
The prevalence of obesity has been drastically increasing over the past 20 years. Other obesity related conditions, including type 2 diabetes mellitus, have also increased in a corresponding manner and, in 2005, the American Diabetes Association (ADA) reduced the cut-off for defining impaired blood glucose. Evidence suggests that just a modest amount of weight loss can improve obesity related co-morbidities. The present study first, investigated changes in health measures after participation in a four week residential weight loss program. Second, individuals were classified according to the 2005 criteria for the diagnosis of type 2 diabetes to determine if glucose regulation changed after weight loss. A total of 93 individuals were categorized as normal glucose (n=56), impaired fasting glucose (n=23) or diabetic range (n=14) after initial blood laboratory screening. After four weeks and a 6.5% weight reduction, participants showed significant improvements in health risks. Further, most participants with elevated fasting glucose shifted into a healthier range. Findings are discussed in terms of health improvements that occur after weight loss within a four week lifestyle intervention.
Wang, Tiange; Leng, Junhong; Li, Nan; Martins de Carvalho, Aline; Huang, Tao; Zheng, Yan; Li, Weiqin; Liu, Huikun; Wang, Leishen; Hu, Gang; Qi, Lu
2015-12-01
Polycystic ovary syndrome (PCOS) is a common condition in reproductive-aged women and a major female-specific risk factor of obesity, impaired glucose tolerance, and diabetes. We examined whether the genetic variation predisposing to PCOS affected glycemic changes in women with prior gestational diabetes mellitus (GDM) and whether such an effect was modified by changes in body adiposity, especially during and after pregnancy. This is a longitudinal study in Tianjin, China. We genotyped 7 genome-wide association study-identified PCOS single nucleotide polymorphisms and assessed gestational weight gain and changes in glycemic traits and weight at 1 to 5 years postpartum in 1133 women with prior GDM. The main outcome measure was postpartum glycemic changes. The PCOS genetic risk score significantly interacted with postpartum weight reduction on changes in fasting glucose and 2-h glucose (P for interaction = .032 and .007; respectively) after multivariable adjustment. In women with postpartum weight reduction of ≥ 5 kg/y, the genetic risk score was associated with decreased fasting and 2-h glucose, whereas an opposite genetic effect was found in women who lost less weight. The association between postpartum weight reduction and glycemic improvement was more significant among women with a higher genetic risk score. In a large cohort of Chinese women with a history of GDM, our data for the first time indicate that the genetic predisposition to PCOS may interact with postpartum weight reduction on long-term glycemic changes, emphasizing the importance of postpartum weight management in prevention of diabetes in this subgroup of women.
Geiker, N R W; Horn, J; Astrup, A
2017-04-01
Among women with hypertrophic breasts, the clear majority are overweight or obese. Owing to increased risk of complications, women with a body mass index (BMI) above 25 kg m -2 are precluded from reduction mammaplasty. The primary aim was to investigate if intensive weight loss could ready women with overweight for breast reduction surgery. Six women, all overweight [BMI 30.9 {28.5; 35.8} kg m -2 ] with symptomatic hypertrophy of the breast, were included a 12-week weight loss program. All women desired reduction mammaplasty and were motivated for preoperational weight loss. The first 8 weeks consisted of a formula-based diet supplying 800 kcal daily, in the subsequent 4 weeks regular foods were reintroduced increasing the intake to 1200 kcal daily. Five women completed the trial, and achieved a median (range) weight loss of 10.2 (6.5; 19) kg. Initial breast volume was 1100-2500 mL per breast, this was reduced by 300 (200; 500) mL after the intervention; equivalent to approximately 19%. Waist, hip, upper arm and thorax circumference were significantly reduced following weight loss. At end of study, all the women still suffered from symptomatic breast hypertrophy to substantiate reduction mammaplasty. Surgeries were performed 2 months thereafter. A 12-week intensive preoperative weight loss program enabled women with obesity for breast reduction surgery. Breast size was reduced proportionally more than total weight loss among women with hypertrophy. © 2017 World Obesity Federation.
Shi, Xiao-Qing; Li, Xiao-Nuo; Yang, Jian-Xin
2013-01-01
Transportation is the key industry of urban energy consumption and carbon emissions. The transformation of conventional gasoline vehicles to new energy vehicles is an important initiative to realize the goal of developing low-carbon city through energy saving and emissions reduction, while electric vehicles (EV) will play an important role in this transition due to their advantage in energy saving and lower carbon emissions. After reviewing the existing researches on energy saving and emissions reduction of electric vehicles, this paper analyzed the factors affecting carbon emissions reduction. Combining with electric vehicles promotion program in Beijing, the paper analyzed carbon emissions and reduction potential of electric vehicles in six scenarios using the optimized energy consumption related carbon emissions model from the perspective of fuel life cycle. The scenarios included power energy structure, fuel type (energy consumption per 100 km), car type (CO2 emission factor of fuel), urban traffic conditions (speed), coal-power technologies and battery type (weight, energy efficiency). The results showed that the optimized model was able to estimate carbon emissions caused by fuel consumption more reasonably; electric vehicles had an obvious restrictive carbon reduction potential with the fluctuation of 57%-81.2% in the analysis of six influencing factors, while power energy structure and coal-power technologies play decisive roles in life-cycle carbon emissions of electric vehicles with the reduction potential of 78.1% and 81.2%, respectively. Finally, some optimized measures were proposed to reduce transport energy consumption and carbon emissions during electric vehicles promotion including improving energy structure and coal technology, popularizing energy saving technologies and electric vehicles, accelerating the battery R&D and so on. The research provides scientific basis and methods for the policy development for the transition of new energy vehicles in low-carbon transport.
Identifying and analyzing methods for reducing the energy consumption of helicopters
NASA Technical Reports Server (NTRS)
Davis, S. J.; Rosenstein, H. J.
1976-01-01
Reductions in helicopter energy consumption can be accomplished through the use of advanced technology in the areas of powerplant design, improved rotor efficiency, reduced parasite drag, and reduced structural empty weight. Baseline helicopters incorporating technology were designed for a short range (200 n mi) and a very short haul (100 n mi) mission scenario. Parametric analyses were then conducted to determine the impact of technology improvement. Many of the parameters varied are interrelated. A summary of such interactions is presented, and some additional sensitivity values were added so that energy reduction and DOC as affected by the major technological factors or operational modes are clearly defined.
[Strategies for successful weight reduction - focus on energy balance].
Weck, M; Bornstein, S R; Barthel, A; Blüher, M
2012-10-01
The prevalence of obesity and related health problems is increasing worldwide and also in Germany. It is well known that substantial and sustained weight loss is difficult to accomplish. Therefore, a variety of studies has been performed in order to specify causes for weight gain and create hypotheses for better treatment options. Key factors of this problem are an adaptation of energy metabolism, especially resting metabolic rate (RMR), non-exercise thermogenesis and diet induced thermogenesis. The extremely high failure rate (> 80%) to keep the reduced weight after successful weight loss is due to adaptation processes of the body to maintain body energy stores. This so called "adaptive thermogenesis" is defined as a smaller than predicted change of energy expenditure in response to changes in energy balance. Adaptive thermogenesis appears to be a major reason for weight regain. The foremost objective of weight-loss programs is the reduction in body fat. However, a concomitant decline in lean tissue can frequently be observed. Since lean body mass (LBM) represents a key determinant of RMR it follows that a decrease in lean tissue could counteract the progress of weight loss. Therefore, with respect to long-term effectiveness of weight reduction programs, the loss of fat mass while maintaining LBM and RMR seems desirable. In this paper we will discuss the mechanisms of adaptive thermogenesis and develop therapeutic strategies with respect to avoiding weight regain successful weight reduction. © Georg Thieme Verlag KG Stuttgart · New York.
Ball, M Patricia; Warren, Kimberly R; Feldman, Stephanie; McMahon, Robert P; Kelly, Deanna L; Buchanan, Robert W
2011-04-01
In recent years, several pharmacological and psychosocial interventions have examined ways to prevent or treat weight gain in people receiving second-generation antipsychotics. While there has been some success, in general, results have not been compelling. Atomoxetine is a selective norepinepherine reuptake inhibitor found to be associated with appetite suppression. Therefore, we examined whether atomoxetine may be of benefit for those who have gained weight on either clozapine or olanzapine. The study was a double-blind, placebo-controlled trial. All participants received the same psychosocial platform: a structured support and exercise group. People with schizophrenia or schizoaffective disorder, on olanzapine or clozapine, who had gained at least 7% of their pre-clozapine or pre-olanzapine weight were eligible for a 24-week, randomized, parallel group, double-blind comparison of adjunctive atomoxetine or placebo. Thirty-seven participants (20 atomoxetine, 17 placebo) were randomized and 26 participants (14 atomoxetine, 12 placebo; 70.2%) completed the study. There were no significant group differences in baseline BMI (atomoxetine: 34.5±4.9; placebo: 35.7±7.0) or weight (atomoxetine: 102.2±15.7 kg; placebo: 104.3±17.5 kg). Both treatment groups showed modest, not significant, trends in weight loss, averaging about 2 kg. Gender or baseline antipsychotic treatment did not modify treatment effects on weight. Secondary outcomes included neuropsychological assessments, symptom assessments (BPRS, SANS) and safety assessments. Of these, only the group difference in Gordon distractibility test scores was statistically significant and favored treatment with atomoxetine. Atomoxetine is not effective for weight loss in this population, but both olanzapine and clozapine participants can lose weight with structured group support and exercise.
Determination of the Airborne Sound Insulation of a Straw Bale Partition Wall
NASA Astrophysics Data System (ADS)
Teslík, Jiří; Fabian, Radek; Hrubá, Barbora
2017-06-01
This paper describes the results of a scientific project focused on determining of the Airborne Sound Insulation of a peripheral non-load bearing wall made of straw bales expressed by Weighted Sound Reduction Index. Weighted Sound Reduction Index was determined by measuring in the certified acoustic laboratory at the Faculty of Mechanical Engineering at Brno University of Technology. The measured structure of the straw wall was modified in combinations with various materials, so the results include a wide range of possible compositions of the wall. The key modification was application of plaster on both sides of the straw bale wall. This construction as is frequently done in actual straw houses. The additional measurements were performed on the straw wall with several variants of additional wall of slab materials. The airborne sound insulation value has been also measured in separate stages of the construction. Thus it is possible to compare and determinate the effect of the single layers on the airborne sound insulation.
Insect-inspired wing actuation structures based on ring-type resonators
NASA Astrophysics Data System (ADS)
Bolsman, Caspar T.; Goosen, Johannes F. L.; van Keulen, Fred
2008-03-01
In this paper, we illustrate and study the opportunities of resonant ring type structures as wing actuation mechanisms for a flapping wing Micro Air Vehicle (MAV). Various design alternatives are presented and studied based on computational and physical models. Insects provide an excellent source of inspiration for the development of the wing actuation mechanisms for flapping wing MAVs. The insect thorax is a structure which in essence provides a mechanism to couple the wing muscles to the wings while offering weight reduction through application of resonance, using tailored elasticity. The resonant properties of the thorax are a very effective way to reducing the power expenditure of wing movement. The wing movement itself is fairly complex and is guided by a set of control muscles and thoracic structures which are present in proximity of the wing root. The development of flapping wing MAVs requires a move away from classical structures and actuators. The use of gears and rotational electric motors is hard to justify at the small scale. Resonant structures provide a large design freedom whilst also providing various options for actuation. The move away from deterministic mechanisms offers possibilities for mass reduction.
Vecchio, Fabrizio; Miraglia, Francesca; Curcio, Giuseppe; Altavilla, Riccardo; Scrascia, Federica; Giambattistelli, Federica; Quattrocchi, Carlo Cosimo; Bramanti, Placido; Vernieri, Fabrizio; Rossini, Paolo Maria
2015-01-01
A relatively new approach to brain function in neuroscience is the "functional connectivity", namely the synchrony in time of activity in anatomically-distinct but functionally-collaborating brain regions. On the other hand, diffusion tensor imaging (DTI) is a recently developed magnetic resonance imaging (MRI)-based technique with the capability to detect brain structural connection with fractional anisotropy (FA) identification. FA decrease has been observed in the corpus callosum of subjects with Alzheimer's disease (AD) and mild cognitive impairment (MCI, an AD prodromal stage). Corpus callosum splenium DTI abnormalities are thought to be associated with functional disconnections among cortical areas. This study aimed to investigate possible correlations between structural damage, measured by MRI-DTI, and functional abnormalities of brain integration, measured by characteristic path length detected in resting state EEG source activity (40 participants: 9 healthy controls, 10 MCI, 10 mild AD, 11 moderate AD). For each subject, undirected and weighted brain network was built to evaluate graph core measures. eLORETA lagged linear connectivity values were used as weight of the edges of the network. Results showed that callosal FA reduction is associated to a loss of brain interhemispheric functional connectivity characterized by increased delta and decreased alpha path length. These findings suggest that "global" (average network shortest path length representing an index of how efficient is the information transfer between two parts of the network) functional measure can reflect the reduction of fiber connecting the two hemispheres as revealed by DTI analysis and also anticipate in time this structural loss.
Lifestyle intervention reduces body weight and improves cardiometabolic risk factors in worksites.
Salinardi, Taylor C; Batra, Payal; Roberts, Susan B; Urban, Lorien E; Robinson, Lisa M; Pittas, Anastassios G; Lichtenstein, Alice H; Deckersbach, Thilo; Saltzman, Edward; Das, Sai Krupa
2013-04-01
Worksites are potentially effective locations for obesity control because they provide opportunities for group intervention and social support. Studies are needed to identify effective interventions in these settings. We examined the effects of a multicomponent lifestyle intervention on weight loss and prevention of regain in 4 worksites (2 intervention and 2 control sites). Overweight and obese employees (n = 133) enrolled in this pilot worksite-randomized controlled trial with a 0-6-mo weight-loss phase and a 6-12-mo structured weight-maintenance phase. The intervention combined recommendations to consume a reduced-energy, low-glycemic load, high-fiber diet with behavioral change education. Outcome measurements included changes in body weight and cardiometabolic risk factors. The mean ± SEM weight loss was substantial in intervention participants, whereas control subjects gained weight (-8.0 ± 0.7 compared with +0.9 ± 0.5 kg, respectively; P < 0.001), and 89% of participants completed the weight-loss phase. Intervention effects were not significant at the 0.05 level but would have been at the 0.10 level (P = 0.08) in a mixed model in which the worksite nested within group was a random factor. There were also significant improvements in cardiometabolic risk factors in intervention compared with control subjects regarding fasting total cholesterol, glucose, systolic blood pressure, and diastolic blood pressure (P ≤ 0.02 for each). No significant weight regain was observed in participants who enrolled in the structured weight-maintenance program (0.5 ± 0.7 kg; P = 0.65), and overweight and obese employees in intervention worksites who were not enrolled in the weight-loss program lost weight compared with subjects in control worksites (-1.3 ± 0.5 compared with +0.7 ± 0.2 kg, respectively; P = 0.02). Worksites can be effective for achieving clinically important reductions in body weight and improved cardiometabolic risk factors. This trial was registered at clinicaltrials.gov as NCT01470222.
Ifejika, Nneka Lotea; Noser, Elizabeth Anne; Grotta, James C; Savitz, Sean I
2016-07-01
Swipe out Stroke (SOS) examines the use of a smartphone-based mobile application to reduce obesity in high-risk minority stroke patients. At record-high levels in the United States, obesity disproportionately affects minorities and is highly correlated with cerebrovascular disease. Unfortunately, structured weight loss programs are expensive, and compliance significantly decreases upon program completion. Mobile health (mHealth) technology is an innovative, cost-effective way to bridge this gap. Minorities spend over 4.5 billion dollars annually on consumer electronics, making studies that utilize mHealth applications ideal for health promotion and disease prevention. SOS is a prospective, randomized-controlled trial with open blinded endpoint comparing an mHealth based dietary intervention to usual care to facilitate weight reduction. Ischemic and hemorrhagic stroke survivors and their carers are recruited from the acute care service of a Houston-based comprehensive stroke center. A neurorehabilitation physician or vascular neurologist meets with participants during the index hospitalization, a baseline clinic visit, followed by visits at 1, 3, and 6 month intervals. The SOS Team focuses on feasible modifications to the Southern dietary pattern (fried foods, fatty foods, added fats, eggs, processed meats, such as bacon and ham, organ meats (e.g., liver), and sweetened drinks) and caloric restriction to facilitate a 5% reduction in total body weight. Practical barriers to adherence are addressed, such as access to transportation, financial limitations, and depression. The primary dependent measure is a reduction of total body weight. Secondary outcomes include systolic blood pressure, hemoglobin A1c, low-density lipoprotein, triglycerides, and Factor VIII. SOS will determine whether a Phase III effectiveness trial of a smartphone-based mobile application to address obesity-related health disparities is warranted throughout the Southeastern United States (Stroke Belt). © 2016 World Stroke Organization.
Weight Reduction Techniques Adopted When Weight Standards are Enforced
1993-01-01
ORGANIZATION NAME(S) AND ADDRESS(ES) 8, PERFORMING ORGANIZATION Military Nutrition Division REPORT NUMBER U. S. Army Research Institute of Environmental...affecting more soldiers than those Identified by the AWCP and possibly developing during a career In the Army. Nutrition /education programs should...that appeas to be Inevitable with aging and a career in the’Army. 14. SUBJECT TERMS 15. NUMBIEN OF PAGES Nutrition , weight reduction, Army weight
Chin, Sang Ouk; Keum, Changwon; Woo, Junghoon; Park, Jehwan; Choi, Hyung Jin; Woo, Jeong-taek; Rhee, Sang Youl
2016-01-01
A discrepancy exists with regard to the effect of smartphone applications (apps) on weight reduction due to the several limitations of previous studies. This is a retrospective cohort study, aimed to investigate the effectiveness of a smartphone app on weight reduction in obese or overweight individuals, based on the complete enumeration study that utilized the clinical and logging data entered by Noom Coach app users between October 2012 and April 2014. A total of 35,921 participants were included in the analysis, of whom 77.9% reported a decrease in body weight while they were using the app (median 267 days; interquartile range = 182). Dinner input frequency was the most important factor for successful weight loss (OR = 10.69; 95% CI = 6.20–19.53; p < 0.001), and more frequent input of weight significantly decreased the possibility of experiencing the yo-yo effect (OR = 0.59, 95% CI = 0.39–0.89; p < 0.001). This study demonstrated the clinical utility of an app for successful weight reduction in the majority of the app users; the effects were more significant for individuals who monitored their weight and diet more frequently. PMID:27819345
technology may exceed the state's gross vehicle weight limits by up to 400 pounds to compensate for the additional weight of the idle reduction technology. To be eligible for the weight exemption, the vehicle operator must be able to provide proof that the idle reduction technology is fully functional. (Reference
Code of Federal Regulations, 2010 CFR
2010-07-01
... standards for pultrusion operations subject to the 60 weight percent organic HAP emissions reductions... National Emissions Standards for Hazardous Air Pollutants: Reinforced Plastic Composites Production Options... operations subject to the 60 weight percent organic HAP emissions reductions requirement? You must use one or...
A Behavioral Weight Reduction Model for Moderately Mentally Retarded Adolescents.
ERIC Educational Resources Information Center
Rotatori, Anthony F.; And Others
1980-01-01
A behavioral weight reduction treatment and maintenance program for moderately mentally retarded adolescents which involves six phases from background information collection to followup relies on stimulus control procedures to modify eating behaviors. Data from pilot studies show an average weekly weight loss of .5 to 1 pound per S. (CL)
Structural Studies of Sol-Gel Glasses
1992-07-14
were prepared from tetramethylorthosilicate (TMOS) and titanium isopropoxide in a six step process of mixing, casting, gelation, aging, drying and...glass matrix although the incorporation of low levels (3% by weight) of titanium into tetrahedral sites only, led to more disordered glasses than...between 615 and 1000"C. The addition of titanium also leads to a reduction in surface ’free’ silanol levels together with an increase in hydrogen bonded
Bottom-up approach for microstructure optimization of sound absorbing materials.
Perrot, Camille; Chevillotte, Fabien; Panneton, Raymond
2008-08-01
Results from a numerical study examining micro-/macrorelations linking local geometry parameters to sound absorption properties are presented. For a hexagonal structure of solid fibers, the porosity phi, the thermal characteristic length Lambda('), the static viscous permeability k(0), the tortuosity alpha(infinity), the viscous characteristic length Lambda, and the sound absorption coefficient are computed. Numerical solutions of the steady Stokes and electrical equations are employed to provide k(0), alpha(infinity), and Lambda. Hybrid estimates based on direct numerical evaluation of phi, Lambda('), k(0), alpha(infinity), Lambda, and the analytical model derived by Johnson, Allard, and Champoux are used to relate varying (i) throat size, (ii) pore size, and (iii) fibers' cross-section shapes to the sound absorption spectrum. The result of this paper tends to demonstrate the important effect of throat size in the sound absorption level, cell size in the sound absorption frequency selectivity, and fibers' cross-section shape in the porous material weight reduction. In a hexagonal porous structure with solid fibers, the sound absorption level will tend to be maximized with a 48+/-10 microm throat size corresponding to an intermediate resistivity, a 13+/-8 microm fiber radius associated with relatively small interfiber distances, and convex triangular cross-section shape fibers allowing weight reduction.
NASA Astrophysics Data System (ADS)
Richards, Terry; Kauppi, Erik; Flanagan, Lauren; Ribeio, Eduardo A. A. G.; Nogueira, Marcos A. Stuart; McCourtney, Ian
This paper presents the advantages of replacing mild steel with high strength niobium microalloyed steel in the structure of Electric Super Scooters, Electric Cargo Motorcycles and Solar Charging Stations. The Mini-Fleet-in-a-Box concept was developed by Current Motor to guarantee mobility, efficiency and solar generated electricity. With the adoption of niobium microalloyed high strength steel for more than 90% of the Super Scooter and Motorcycle structures, it was possible to redesign the frame, resulting in a 31% weight reduction and a very modern and functional body. Together with a new powertrain, these changes were responsible for increasing Motorcycle autonomy by more than 15%, depending on average speed. The new frame design reduced the number of high strain points in the frame, increasing the safety of the project. The Solar Charging Station was built using the container concept and designed with high strength niobium microalloyed steel, which resulted in a weight reduction of 25%. CBMM's facility in Araxá, Brazil was selected in the second half of 2013 as the demonstration site to test the efficiency of the Super Scooter and Solar Charging Station. Each Super Scooter has run more than 2,000 km maintenance-free with an autonomy of more than 100 km per charge.
The impact of reducing car weight on global emissions: the future fleet in Great Britain
NASA Astrophysics Data System (ADS)
Serrenho, André Cabrera; Norman, Jonathan B.; Allwood, Julian M.
2017-05-01
Current European policies define targets for future direct emissions of new car sales that foster a fast transition to electric drivetrain technologies. However, these targets do not consider the emissions produced in electricity generation and material production, and therefore fail to incentivise car manufacturers to consider the benefits of vehicle weight reduction. In this paper, we examine the potential benefits of limiting the average weight and altering the material composition of new cars in terms of global greenhouse gas emissions produced during the use phase, electricity generation and material production. We anticipate the emissions savings for the future car fleet in Great Britain until 2050 for various alternative futures, using a dynamic material flow analysis of ferrous metals and aluminium, and considering an evolving demand for car use. The results suggest that fostering vehicle weight reduction could produce greater cumulative emissions savings by 2050 than those obtained by incentivising a fast transition to electric drivetrains, unless there is an extreme decarbonization of the electricity grid. Savings promoted by weight reduction are immediate and do not depend on the pace of decarbonization of the electricity grid. Weight reduction may produce the greatest savings when mild steel in the car body is replaced with high-strength steel. This article is part of the themed issue 'Material demand reduction'.
Himmelstein, M. S.; Gorin, A. A.; Suh, Y. J.
2017-01-01
Summary Objective Pervasive weight stigma and discrimination have led to ongoing calls for efforts to reduce this bias. Despite increasing research on stigma‐reduction strategies, perspectives of individuals who have experienced weight stigma have rarely been included to inform this research. The present study conducted a systematic examination of women with high body weight to assess their perspectives about a broad range of strategies to reduce weight‐based stigma. Methods Women with overweight or obesity (N = 461) completed an online survey in which they evaluated the importance, feasibility and potential impact of 35 stigma‐reduction strategies in diverse settings. Participants (91.5% who reported experiencing weight stigma) also completed self‐report measures assessing experienced and internalized weight stigma. Results Most participants assigned high importance to all stigma‐reduction strategies, with school‐based and healthcare approaches accruing the highest ratings. Adding weight stigma to existing anti‐harassment workplace training was rated as the most impactful and feasible strategy. The family environment was viewed as an important intervention target, regardless of participants' experienced or internalized stigma. Conclusion These findings underscore the importance of including people with stigmatized identities in stigma‐reduction research; their insights provide a necessary and valuable contribution that can inform ways to reduce weight‐based inequities and prioritize such efforts. PMID:28392929
Extended analytical study of the free-wing/free-trimmer concept
NASA Technical Reports Server (NTRS)
Porter, R. F.; Hall, D. W.; Vergara, R. D.
1979-01-01
The free wing/free trimmer concept was analytically studied in order to: (1) compare the fore and aft trimmer configurations on the basis of equal lift capability, rather than equal area; (2) assess the influence of tip mounted aft trimmers, both free and fixed, on the lateral directional modes and turbulence responses; (3) examine the feasibility of using differential tip mounted trimmer deflection for lateral control; (4) determine the effects of independent fuselage attitude on the lateral directional behavior; and (5) estimate the influence of wing sweep on dynamic behavior and structural weight. Results indicate that the forward trimmer concept is feasible with the reduced size examined, but it remains inferior to the aft trimmer in every respect except structural weight. Differential motion of the aft trimmer is found to provide powerful lateral control; while the effect of fuselage deck angle is a reduction of the dutch roll damping ratio for nose-down attitudes.
A Novel Design Framework for Structures/Materials with Enhanced Mechanical Performance
Liu, Jie; Fan, Xiaonan; Wen, Guilin; Qing, Qixiang; Wang, Hongxin; Zhao, Gang
2018-01-01
Structure/material requires simultaneous consideration of both its design and manufacturing processes to dramatically enhance its manufacturability, assembly and maintainability. In this work, a novel design framework for structural/material with a desired mechanical performance and compelling topological design properties achieved using origami techniques is presented. The framework comprises four procedures, including topological design, unfold, reduction manufacturing, and fold. The topological design method, i.e., the solid isotropic material penalization (SIMP) method, serves to optimize the structure in order to achieve the preferred mechanical characteristics, and the origami technique is exploited to allow the structure to be rapidly and easily fabricated. Topological design and unfold procedures can be conveniently completed in a computer; then, reduction manufacturing, i.e., cutting, is performed to remove materials from the unfolded flat plate; the final structure is obtained by folding out the plate from the previous procedure. A series of cantilevers, consisting of origami parallel creases and Miura-ori (usually regarded as a metamaterial) and made of paperboard, are designed with the least weight and the required stiffness by using the proposed framework. The findings here furnish an alternative design framework for engineering structures that could be better than the 3D-printing technique, especially for large structures made of thin metal materials. PMID:29642555
A Novel Design Framework for Structures/Materials with Enhanced Mechanical Performance.
Liu, Jie; Fan, Xiaonan; Wen, Guilin; Qing, Qixiang; Wang, Hongxin; Zhao, Gang
2018-04-09
Abstract : Structure/material requires simultaneous consideration of both its design and manufacturing processes to dramatically enhance its manufacturability, assembly and maintainability. In this work, a novel design framework for structural/material with a desired mechanical performance and compelling topological design properties achieved using origami techniques is presented. The framework comprises four procedures, including topological design, unfold, reduction manufacturing, and fold. The topological design method, i.e., the solid isotropic material penalization (SIMP) method, serves to optimize the structure in order to achieve the preferred mechanical characteristics, and the origami technique is exploited to allow the structure to be rapidly and easily fabricated. Topological design and unfold procedures can be conveniently completed in a computer; then, reduction manufacturing, i.e., cutting, is performed to remove materials from the unfolded flat plate; the final structure is obtained by folding out the plate from the previous procedure. A series of cantilevers, consisting of origami parallel creases and Miura-ori (usually regarded as a metamaterial) and made of paperboard, are designed with the least weight and the required stiffness by using the proposed framework. The findings here furnish an alternative design framework for engineering structures that could be better than the 3D-printing technique, especially for large structures made of thin metal materials.
Senna, Mohammed Kamal; Sallam, Rehab Abd-El Raouf; Ashour, Hala Salah; Elarman, Mohammed
2012-11-01
The aim of the study was to examine whether weight reduction can result in improvement of fibromyalgia impact questionnaire (FIQ) in the patients with fibromyalgia syndrome (FMS). This study was a randomized controlled trial. Obese patients with fibromyalgia were randomly assigned to 6-month dietary weight loss (n = 41) and no weight loss (n = 42) groups. Patients were assessed at baseline and at 6 months. The primary outcome measure was FIQ. Secondary measures included the tender point (TP) examination, Beck Depression Inventory-II, and Pittsburg Sleep Quality Index. Compared to the control group, patients who underwent weight reduction obtained significantly better FIQ (p = 0.007), lower mean TP count (p = 0.015), and lower mean TP pain rating in the lower body (p < 0.001). Patients who lost weight had less depression and better sleep quality than the controls. Patients who lost weight had significantly lower interleukin 6 and C-reactive protein levels than those in the control group (p = 0.034 and p = 0.007, respectively). Weight loss in obese patients with FMS leads to significant improvement in the quality of life as shown by the decrease in the FIQ score. Depression, sleep quality, and tender point count are also significantly improved by weight loss in obese patients with fibromyalgia. Our results suggest that weight reduction should be a part of fibromyalgia treatment.
Espinet Coll, Eduardo; Nebreda Durán, Javier; López-Nava Breviere, Gontrand; Galvao Neto, Manoel; Gómez Valero, José Antonio; Bacchiddu, Silvia; Vila Lolo, Carmen; Díaz Galán, Patricia; Bautista-Castaño, Inmaculada; Juan-Creix Comamala, Antonio
2018-05-09
many patients that undergo bariatric surgery (Roux-en-Y gastric bypass [RYGB]) may regain some of their weight lost over time. A transoral outlet reduction (TORe) with endoscopic suture could be a valid alternative in these patients. this was a retrospective initial series of 13 consecutive patients with weight regain after RYGB and a dilated gastro-jejunal anastomosis (> 15 mm). TORe was performed using an endoscopic transmural suture device (OverStitch-Apollo®), which was used to reduce the anastomosis aperture and also to treat the gastric pouch. The initial data of feasibility, safety and weight loss are described with a limited follow-up of six months. there was a mean maximum weight loss of 37.69 kg after RYGB and a subsequent average regain of 21.62 kg. The mean anastomosis diameter was 36 mm (range 20-45) which was reduced to 9 mm (range 5-12) (75% reduction), with an average of 2.5 sutures. The mean pouch size was 7.2 cm (range 2-10), which decreased to 4.7 cm (range 4-5) (34.72% reduction), with an average of 2.7 sutures. The mean weight loss six months after TORe was 12.29 kg, a weight loss of 56.85% of the weight regained after RYGB. No complications related to the procedure were recorded. endoscopic suture reduction of the dilated gastro-jejunal anastomosis and the gastric pouch seems a feasible and safe option in our limited initial experience. With a multidisciplinary approach and a short term follow-up, this seems to be a minimally invasive and effective option to control weight regain after RYGB.
Moderate energy restriction with high protein diet results in healthier outcome in women.
Mero, Antti A; Huovinen, Heikki; Matintupa, Olle; Hulmi, Juha J; Puurtinen, Risto; Hohtari, Hannele; Karila, Tuomo Am
2010-01-25
The present study compares two different weight reduction regimens both with a moderately high protein intake on body composition, serum hormone concentration and strength performance in non-competitive female athletes. Fifteen normal weighted women involved in recreational resistance training and aerobic training were recruited for the study (age 28.5 +/- 6.3 yr, height 167.0 +/- 7.0 cm, body mass 66.3 +/- 4.2 kg, body mass index 23.8 +/- 1.8, mean +/- SD). They were randomized into two groups. The 1 KG group (n = 8; energy deficit 1100 kcal/day) was supervised to reduce body weight by 1 kg per week and the 0.5 KG group (n = 7; energy deficit 550 kcal/day) by 0.5 kg per week, respectively. In both groups protein intake was kept at least 1.4 g/kg body weight/day and the weight reduction lasted four weeks. At the beginning of the study the energy need was calculated using food and training diaries. The same measurements were done before and after the 4-week weight reduction period including total body composition (DXA), serum hormone concentrations, jumping ability and strength measurements During the 4-week weight reduction period there were no changes in lean body mass and bone mass, but total body mass, fat mass and fat percentage decreased significantly in both groups. The changes were greater in the 1 KG group than in the 0.5 KG group in total body mass (p < 0.001), fat mass (p < 0.001) and fat percentage (p < 0.01). Serum testosterone concentration decreased significantly from 1.8 +/- 1.0 to 1.4 +/- 0.9 nmol/l (p < 0.01) in 1 KG and the change was greater in 1 KG (30%, p < 0.001) than in 0.5 KG (3%). On the other hand, SHBG increased significantly in 1 KG from 63.4 +/- 17.7 to 82.4 +/- 33.0 nmol/l (p < 0.05) during the weight reducing regimen. After the 4-week period there were no changes in strength performance in 0.5 KG group, however in 1 KG maximal strength in bench press decreased (p < 0.05) while endurance strength in squat and counter movement jump improved (p < 0.05) It is concluded that a weight reduction by 0.5 kg per week with ~1.4 g protein/kg body weight/day can be recommended to normal weighted, physically active women instead of a larger (e.g. 1 kg per week) weight reduction because the latter may lead to a catabolic state. Vertical jumping performance is improved when fat mass and body weight decrease. Thus a moderate weight reduction prior to a major event could be considered beneficial for normal built athletes in jumping events.
Murakawa, Takeshi; Hayashi, Hideyuki; Sunami, Tomoko; Kurihara, Kazuo; Tamada, Taro; Kuroki, Ryota; Suzuki, Mamoru; Tanizawa, Katsuyuki; Okajima, Toshihide
2013-12-01
The crystal structure of a copper amine oxidase from Arthrobacter globiformis was determined at 1.08 Å resolution with the use of low-molecular-weight polyethylene glycol (LMW PEG; average molecular weight ∼200) as a cryoprotectant. The final crystallographic R factor and Rfree were 13.0 and 15.0%, respectively. Several molecules of LMW PEG were found to occupy cavities in the protein interior, including the active site, which resulted in a marked reduction in the overall B factor and consequently led to a subatomic resolution structure for a relatively large protein with a monomer molecular weight of ∼70,000. About 40% of the presumed H atoms were observed as clear electron densities in the Fo - Fc difference map. Multiple minor conformers were also identified for many residues. Anisotropic displacement fluctuations were evaluated in the active site, which contains a post-translationally derived quinone cofactor and a Cu atom. Furthermore, diatomic molecules, most likely to be molecular oxygen, are bound to the protein, one of which is located in a region that had previously been proposed as an entry route for the dioxygen substrate from the central cavity of the dimer interface to the active site.
Success of women in a worksite weight loss program: Does being part of a group help?
Rigsby, Andrea; Gropper, Daniel M; Gropper, Sareen S
2009-04-01
This study reports the results of a worksite weight loss program which allowed female hospital and nursing home employees to enroll in a worksite weight loss program as individuals or as part of a group. After 8 weeks, employees (irrespective of group versus individual participation) lost an average of 6.2 lb and 1.5% body fat. The initial weight, body fat, and body mass index reductions were all significantly greater, in absolute and percentage terms, among group participants than individual participants. Weight reduction averaged 7.6+1.1 lb for group participants and 4.2+6.4 lb for individual participants; body fat reduction was 1.7+1.3% for group participants and 0.9+1.3% for individual participants. Exercising more frequently was significantly associated with weight loss in those participating as a group, while following a written diet plan was significantly associated with weight loss in those participating as individuals.
[Effects of a lower body weight or waist circumference on cardiovascular risk].
Labraña, Ana María; Durán, Eliana; Martínez, María Adela; Leiva, Ana María; Garrido-Méndez, Alex; Díaz, Ximena; Salas, Carlos; Celis-Morales, Carlos
2017-05-01
Overall and central obesity are important risk factors for cardiovascular disease. To investigate the association of body weight, body mass index (BMI) and waist circumference (WC) with cardiovascular risk factors in Chile. We included 5,157 participants from the National Health Survey 2009-2010. Prevalence of type 2 diabetes, hypertension, metabolic syndrome and dyslipidemia (high total cholesterol and triglyceride levels and low HDL-cholesterol) were defined using international recommendations. BMI and WC were measured using standardized protocols. A five percent lower body weight, BMI and WC were associated with a significant reduction in cardiovascular risk factors. For each 5% reduction in body weight, the risk for hypertension decreased by 8 and 9% in women and men respectively. Similar risk reductions were observed for diabetes (9 and 11% respectively), metabolic syndrome (23 and 30% respectively), low HDL cholesterol (13 and 13% respectively), high triglyceride levels (16 and 18% respectively) and total cholesterol (8 and 10% respectively). Similar findings were observed for BMI and WC. Lower body weight, BMI or WC are associated with important reductions in cardiovascular risk factors. A 5% reduction in these adiposity markers could be a perfectly feasible goal for lifestyle interventions.
Wavelet denoising of multiframe optical coherence tomography data
Mayer, Markus A.; Borsdorf, Anja; Wagner, Martin; Hornegger, Joachim; Mardin, Christian Y.; Tornow, Ralf P.
2012-01-01
We introduce a novel speckle noise reduction algorithm for OCT images. Contrary to present approaches, the algorithm does not rely on simple averaging of multiple image frames or denoising on the final averaged image. Instead it uses wavelet decompositions of the single frames for a local noise and structure estimation. Based on this analysis, the wavelet detail coefficients are weighted, averaged and reconstructed. At a signal-to-noise gain at about 100% we observe only a minor sharpness decrease, as measured by a full-width-half-maximum reduction of 10.5%. While a similar signal-to-noise gain would require averaging of 29 frames, we achieve this result using only 8 frames as input to the algorithm. A possible application of the proposed algorithm is preprocessing in retinal structure segmentation algorithms, to allow a better differentiation between real tissue information and unwanted speckle noise. PMID:22435103
Wavelet denoising of multiframe optical coherence tomography data.
Mayer, Markus A; Borsdorf, Anja; Wagner, Martin; Hornegger, Joachim; Mardin, Christian Y; Tornow, Ralf P
2012-03-01
We introduce a novel speckle noise reduction algorithm for OCT images. Contrary to present approaches, the algorithm does not rely on simple averaging of multiple image frames or denoising on the final averaged image. Instead it uses wavelet decompositions of the single frames for a local noise and structure estimation. Based on this analysis, the wavelet detail coefficients are weighted, averaged and reconstructed. At a signal-to-noise gain at about 100% we observe only a minor sharpness decrease, as measured by a full-width-half-maximum reduction of 10.5%. While a similar signal-to-noise gain would require averaging of 29 frames, we achieve this result using only 8 frames as input to the algorithm. A possible application of the proposed algorithm is preprocessing in retinal structure segmentation algorithms, to allow a better differentiation between real tissue information and unwanted speckle noise.
Sköldstam, Lars; Brudin, Lars; Hagfors, Linda; Johansson, Gunnar
2005-01-01
Objectives Several investigators have reported that clinical improvements of patients with rheumatoid arthritis (RA), from participating in therapeutic diet intervention studies, have been accompanied by loss of body weight. This has raised the question whether weight reduction per se can improve RA. In order to test this hypothesis, three previously conducted diet intervention studies, comprising 95 patients with RA, were pooled. Together with Age, Gender, and Disease Duration, change during the test period in body weight, characterised dichotomously as reduction or no reduction (dichoΔBody Weight), as well as Diet (dichotomously as ordinary diet or test diet), were the independent variables. Dependent variables were the difference (Δ) from baseline to conclusion of the study in five different disease outcome measures. ΔESR and ΔPain Score were both characterised numerically and dichotomously (improvement or no improvement). ΔAcute Phase Response, ΔPhysical Function, and ΔTender Joint Count were characterised dichotomously only. Multiple logistic regression was used to analyse associations between the independent and the disease outcome variables. Results Statistically significant correlations were found between Diet and three disease outcome variables i.e. ΔAcute-Phase Response, ΔPain Score, and ΔPhysical Function. Δ Body Weight was univariately only correlated to ΔAcute-Phase Response but not significant when diet was taken into account. Conclusion Body weight reduction did not significantly contribute to the improvement in rheumatoid arthritis when eating lacto-vegetarian, vegan or Mediterranean diets. PMID:15871736
Layered chalcogenide glass structures for IR lenses
NASA Astrophysics Data System (ADS)
Gibson, Daniel; Bayya, Shyam; Sanghera, Jas; Nguyen, Vinh; Scribner, Dean; Maksimovic, Velimir; Gill, John; Yi, Allen; Deegan, John; Unger, Blair
2014-07-01
A technique for fabricating novel infrared (IR) lenses can enable a reduction in the size and weight of IR imaging optics through the use of layered glass structures. These structures can range from having a few thick glass layers, mimicking cemented doublets and triplets, to having many thin glass layers approximating graded index (GRIN) lenses. The effectiveness of these structures relies on having materials with diversity in refractive index (large Δn) and dispersion and similar thermo-viscous behavior (common glass transition temperature, ΔTg = 10°C). A library of 13 chalcogenide glasses with broad IR transmission (NIR through LWIR bands) was developed to satisfy these criteria. The lens fabrication methodology, including glass design and synthesis, sheet fabrication, preform making, lens molding and surface finishing are presented.
Advanced solar concentrator: Preliminary and detailed design
NASA Technical Reports Server (NTRS)
Bell, D. M.; Maraschin, R. A.; Matsushita, M. T.; Erskine, D.; Carlton, R.; Jakovcevic, A.; Yasuda, A. K.
1981-01-01
A single reflection point focusing two-axis tracking paraboloidal dish with a reflector aperture diameter of approximately 11 m has a reflective surface made up of 64 independent, optical quality gores. Each gore is a composite of a thin backsilvered mirror glass face sheet continuously bonded to a contoured substrate of lightweight, rigid cellular glass. The use of largely self-supporting gores allows a significant reduction in the weight of the steel support structure as compared to alternate design concepts. Primary emphasis in the preliminary design package for the low-cost, low-weight, mass producible concentrator was placed on the design of the higher cost subsystems. The outer gore element was sufficiently designed to allow fabrication of prototype gores.
Hypersonic airbreathing vehicle conceptual design (focus on aero-space plane)
NASA Technical Reports Server (NTRS)
Hunt, James L.; Martin, John G.
1989-01-01
The airbreathing single stage to orbit (SSTO) vehicle design environment is variable-rich, intricately networked and sensitivity intensive. As such, it represents a tremondous technology challenge. Creating a viable design will require sophisticated configuration/synthesis and the synergistic integration of advanced technologies across the discipline spectrum. In design exercises, reductions in the fuel weight-fraction requirements projected for an orbital vehicle concept can result from improvements in aerodynamics/controls, propulsion efficiencies and trajectory optimization; also, gains in the fuel weight-fraction achievable for such a concept can result from improvements in structural design, heat management techniques, and material properties. As these technology advances take place, closure on a viable vehicle design will be realizable.
NASA Astrophysics Data System (ADS)
Ho, Jen-Hsuan; Berkhoff, Arthur
2014-03-01
This paper compares various decentralised control strategies, including structural and acoustic actuator-sensor configuration designs, to reduce noise transmission through a double panel structure. The comparison is based on identical control stability indexes. The double panel structure consists of two panels with air in between and offers the advantages of low sound transmission at high frequencies, low heat transmission, and low weight. The double panel structure is widely used, such as in the aerospace and automotive industries. Nevertheless, the resonance of the cavity and the poor sound transmission loss at low frequencies limit the double panel's noise control performance. Applying active structural acoustic control to the panels or active noise control to the cavity has been discussed in many papers. In this paper, the resonances of the panels and the cavity are considered simultaneously to further reduce the transmitted noise through an existing double panel structure. A structural-acoustic coupled model is developed to investigate and compare various structural control and cavity control methods. Numerical analysis and real-time control results show that structural control should be applied to both panels. Three types of cavity control sources are presented and compared. The results indicate that the largest noise reduction is obtained with cavity control by loudspeakers modified to operate as incident pressure sources.
NASA Technical Reports Server (NTRS)
Nguyen, Nhan; James Urnes, Sr.
2012-01-01
Lightweight aircraft design has received a considerable attention in recent years as a means for improving cruise efficiency. Reducing aircraft weight results in lower lift requirements which directly translate into lower drag, hence reduced engine thrust requirements during cruise. The use of lightweight materials such as advanced composite materials has been adopted by airframe manufacturers in current and future aircraft. Modern lightweight materials can provide less structural rigidity while maintaining load-carrying capacity. As structural flexibility increases, aeroelastic interactions with aerodynamic forces and moments become an increasingly important consideration in aircraft design and aerodynamic performance. Furthermore, aeroelastic interactions with flight dynamics can result in issues with vehicle stability and control. Abstract This paper describes a recent aeroelastic modeling effort for an elastically shaped aircraft concept (ESAC). The aircraft model is based on the rigid-body generic transport model (GTM) originally developed at NASA Langley Research Center. The ESAC distinguishes itself from the GTM in that it is equipped with highly flexible wing structures as a weight reduction design feature. More significantly, the wings are outfitted with a novel control effector concept called variable camber continuous trailing edge (VCCTE) flap system for active control of wing aeroelastic deflections to optimize the local angle of attack of wing sections for improved aerodynamic efficiency through cruise drag reduction and lift enhancement during take-off and landing. The VCCTE flap is a multi-functional and aerodynamically efficient device capable of achieving high lift-to-drag ratios. The flap system is comprised of three chordwise segments that form the variable camber feature of the flap and multiple spanwise segments that form a piecewise continuous trailing edge. By configuring the flap camber and trailing edge shape, drag reduction could be achieved. Moreover, some parts of the flap system can be made to have a high frequency response for roll control, gust load alleviation, and aeroservoelastic (ASE) modal suppression control. Abstract The aeroelastic model of the ESAC is based on one-dimensional structural dynamic theory that captures the aeroelastic deformation of a wing structure in a combined motion that involves flapwise bending, chordwise bending, and torsion. The model includes the effect of aircraft propulsion due to wing flexibility which causes the propulsive forces and moments to couple with the wing elastic motion. Engine mass is also accounted in the model. A fuel management model is developed to describe the wing mass change due to fuel usage in the main tank and wing tanks during cruise. Abstract The model computes both static and dynamic responses of the wing structures. The static aeroelastic deflections are used to estimate the effect of wing flexibility on induced drag and the potential drag reduction by the VCCTE flap system. A flutter analysis is conducted to estimate the flutter speed boundary. Gust load alleviation via adaptive control has been recently investigated to address flexibility of aircraft structures. A multi-objective flight control approach is presented for drag reduction control. The approach is based on an optimal control framework using a multi-objective cost function. Future studies will demonstrate the potential benefits of the approach.
Management of obesity in non- insulin- dependent diabetes mellitus.
Cheah, J S
1998-12-01
Obesity is common in non-insulin-dependent diabetes mellitus (NIDDM) patients; in Singapore in a cohort of 314 diabetics, 44.3% were overweight. Management of obesity in diabetics differs from that in non-diabetics in that it is more urgent; weight maintenance is more difficult and hypoglycaemic medication may cause weight changes. However, like in the non-diabetic, management of obesity in the diabetic requires a pragmatic and realistic approach. A team approach is required: the help of a nurse educator, a dietitian, behaviour modification therapist, exercise therapist and others are required. A detailed history, careful physical examination and relevant investigations are required to assess the severity of the diabetic state and to exclude an occasional underlying cause of the obesity in the obese NIDDM patient. Weight loss is urgent in the obese NIDDM patient, especially for those with android obesity. There must be a reduction in energy intake. Weight loss leads to an improvement in glucose tolerance and in insulin sensitivity, as well as to a reduction in lipid levels and to a fall in blood pressure in the hypertensive. Exercise is of limited short-term value measured in terms of weight reduction, except in the younger obese NIDDM patient; but it does allow improvement in overall metabolic control and, long-term, is critical for preferred weight maintenance. The biguanide, Metformin, is the hypoglycaemic drug of choice as it leads to consistent weight reduction. The sulphonylureas may cause weight gain. Insulin should be avoided where possible as it causes further weight gain. Other hypoglycaemic agents include Glucobay (alpha-glucosidase inhibitor) and Troglitazone (insulin sensitizer) which do not alter the weight. Orlistat (lipase inhibitor) is promising as it causes reduction of weight, blood glucose and lipid levels. Anti-obesity drugs (noradrenergic and serotonergic agents) have modest effects on weight reduction in the obese NIDDM patient; a widely-used preparation, Dexfenfluramine (Adifax), has been withdrawn because of side-effects. Surgery such as gastric plication is the last resort in treating the morbidly obese NIDDM patient. Against this background, the institution of life-long food and exercise habits which favour health, body composition and fat distribution are paramount in the prevention and minimization of expression of NIDDM. The discovery of leptin in 1994 has led to intense research into energy homeostasis in obesity; hopefully this will lead to better treatment of obesity in diabetics and non-diabetics.
Behavioral Weight Loss for the Management of Menopausal Hot Flashes: A Pilot Study
Thurston, Rebecca C.; Ewing, Linda J.; Low, Carissa A.; Christie, Aimee J.; Levine, Michele D.
2014-01-01
Objective Although adiposity has been considered protective against hot flashes, newer data suggest positive relations between flashes and adiposity. No studies have been specifically designed to test whether weight loss reduces hot flashes. This pilot study aimed to evaluate the feasibility, acceptability, and initial efficacy of behavioral weight loss to reduce hot flashes. Methods Forty overweight/obese women with hot flashes (≥4/day) were randomized to a behavioral weight loss intervention or to wait list control. Hot flashes were assessed pre- and post-intervention via physiologic monitor, diary, and questionnaire. Comparisons of changes in hot flashes and anthropometrics between conditions were tested via Wilcoxon tests. Results Study retention (83%) and intervention satisfaction (93.8%) were high. Most women (74.1%) reported that hot flash reduction was a main motivator to lose weight. Women randomized to the weight loss intervention lost more weight (-8.86 kg) than did women randomized to control (+0.23 kg, p<.0001). Women randomized to weight loss also showed greater reductions in questionnaire-reported hot flashes (2-week hot flashes: −63.0) than did women in the control (−28.0, p=.03), a difference not demonstrated in other hot flash measures. Reductions in weight and hot flashes were significantly correlated (e.g., r=.47, p=.006). Conclusions This pilot study showed a behavioral weight loss program to be feasible, acceptable, and effective in producing weight loss among overweight/obese women with hot flashes. Findings indicate the importance of a larger study designed to test behavioral weight loss for hot flash reduction. Hot flash management could motivate women to engage in this health-promoting behavior. PMID:24977456
Behavioral weight loss for the management of menopausal hot flashes: a pilot study.
Thurston, Rebecca C; Ewing, Linda J; Low, Carissa A; Christie, Aimee J; Levine, Michele D
2015-01-01
Although adiposity has been considered to be protective against hot flashes, newer data suggest positive relationships between hot flashes and adiposity. No studies have been specifically designed to test whether weight loss reduces hot flashes. This pilot study aimed to evaluate the feasibility, acceptability, and initial efficacy of behavioral weight loss in reducing hot flashes. Forty overweight or obese women with hot flashes (≥ 4 hot flashes/d) were randomized to either behavioral weight loss intervention or wait-list control. Hot flashes were assessed before and after intervention via physiologic monitoring, diary, and questionnaire. Comparisons of changes in hot flashes and anthropometrics between conditions were performed via Wilcoxon tests. Study retention (83%) and intervention satisfaction (93.8%) were high. Most women (74.1%) reported that hot flash reduction was a major motivator for losing weight. Women randomized to the weight loss intervention lost more weight (-8.86 kg) than did women randomized to control (+0.23 kg; P < 0.0001). Women randomized to weight loss also showed greater reductions in questionnaire-reported hot flashes (2-wk hot flashes, -63.0) than did women in the control group (-28.0; P = 0.03)-a difference not demonstrated in other hot flash measures. Reductions in weight and hot flashes were significantly correlated (eg, r = 0.47, P = 0.006). This pilot study shows a behavioral weight loss program that is feasible, acceptable, and effective in producing weight loss among overweight or obese women with hot flashes. Findings indicate the importance of a larger study designed to test behavioral weight loss for hot flash reduction. Hot flash management could motivate women to engage in this health-promoting behavior.
Stice, Eric; Marti, C. Nathan; Spoor, Sonja; Presnell, Katherine; Shaw, Heather
2009-01-01
Adolescent girls with body dissatisfaction (N=481; SD=1.4) were randomized to a dissonance-based thin-ideal internalization reduction program, healthy weight control program, expressive-writing control condition, or assessment-only control condition. Dissonance participants showed significantly greater decreases in thin-ideal internalization, body dissatisfaction, negative affect, eating disorder symptoms, and psychosocial impairment, and lower risk for eating pathology onset through 2–3 year follow-up than assessment-only controls. Dissonance participants showed greater decreases in thin-ideal internalization, body dissatisfaction, and psychosocial impairment than expressive-writing controls. Healthy weight participants showed greater decreases in thin-ideal internalization, body dissatisfaction, negative affect, eating disorder symptoms, and psychosocial impairment, less increases in weight, and lower risk for eating pathology and obesity onset through 2–3 year follow-up than assessment-only controls. Healthy weight participants showed greater decreases in thin-ideal internalization and weight than expressive writing controls. Dissonance participants showed a 60% reduction in risk for eating pathology onset and healthy weight participants showed a 61% reduction in risk for eating pathology onset and a 55% reduction in risk for obesity onset relative to assessment-only controls through 3-year follow-up, implying that the effects are clinically important and enduring. PMID:18377128
NASA Technical Reports Server (NTRS)
Chu, Robert L.; Bayha, Tom D.; Davis, HU; Ingram, J. ED; Shukla, Jay G.
1992-01-01
Composite Wing and Fuselage Structural Design/Manufacturing Concepts have been developed and evaluated. Trade studies were performed to determine how well the concepts satisfy the program goals of 25 percent cost savings, 40 percent weight savings with aircraft resizing, and 50 percent part count reduction as compared to the aluminum Lockheed L-1011 baseline. The concepts developed using emerging technologies such as large scale resin transfer molding (RTM), automatic tow placed (ATP), braiding, out-of-autoclave and automated manufacturing processes for both thermoset and thermoplastic materials were evaluated for possible application in the design concepts. Trade studies were used to determine which concepts carry into the detailed design development subtask.
2013-07-01
structure of the data and Gower’s similarity coefficient as the algorithm for calculating the proximity matrices. The following section provides a...representative set of terrorist event data. Attribute Day Location Time Prim /Attack Sec/Attack Weight 1 1 1 1 1 Scale Nominal Nominal Interval Nominal...calculate the similarity it uses Gower’s similarity and multidimensional scaling algorithms contained in an R statistical computing environment
Aircraft energy efficiency. Overview
NASA Technical Reports Server (NTRS)
1981-01-01
Six advanced technology development projects that could cut fuel consumption of future civil air transports by as much as 50 percent are highlighted. These include improved engine components; better engine design; thin short blades for turboprop aircaft; using composite primary structures for weight reduction; the use of supercritical wings, higher aspect ratio, and winglets for improved aerodynamics; active controls; and laminar flow control. The time span of each of the six efforts and NASA's expected expenditures are also discussed.
The impact of reducing car weight on global emissions: the future fleet in Great Britain.
Serrenho, André Cabrera; Norman, Jonathan B; Allwood, Julian M
2017-06-13
Current European policies define targets for future direct emissions of new car sales that foster a fast transition to electric drivetrain technologies. However, these targets do not consider the emissions produced in electricity generation and material production, and therefore fail to incentivise car manufacturers to consider the benefits of vehicle weight reduction. In this paper, we examine the potential benefits of limiting the average weight and altering the material composition of new cars in terms of global greenhouse gas emissions produced during the use phase, electricity generation and material production. We anticipate the emissions savings for the future car fleet in Great Britain until 2050 for various alternative futures, using a dynamic material flow analysis of ferrous metals and aluminium, and considering an evolving demand for car use. The results suggest that fostering vehicle weight reduction could produce greater cumulative emissions savings by 2050 than those obtained by incentivising a fast transition to electric drivetrains, unless there is an extreme decarbonization of the electricity grid. Savings promoted by weight reduction are immediate and do not depend on the pace of decarbonization of the electricity grid. Weight reduction may produce the greatest savings when mild steel in the car body is replaced with high-strength steel.This article is part of the themed issue 'Material demand reduction'. © 2017 The Authors.
Dynamics of hairpin vortices and polymer-induced turbulent drag reduction.
Kim, Kyoungyoun; Adrian, Ronald J; Balachandar, S; Sureshkumar, R
2008-04-04
It has been known for over six decades that the dissolution of minute amounts of high molecular weight polymers in wall-bounded turbulent flows results in a dramatic reduction in turbulent skin friction by up to 70%. First principles simulations of turbulent flow of model polymer solutions can predict the drag reduction (DR) phenomenon. However, the essential dynamical interactions between the coherent structures present in turbulent flows and polymer conformation field that lead to DR are poorly understood. We examine this connection via dynamical simulations that track the evolution of hairpin vortices, i.e., counter-rotating pairs of quasistreamwise vortices whose nonlinear autogeneration and growth, decay and breakup are centrally important to turbulence stress production. The results show that the autogeneration of new vortices is suppressed by the polymer stresses, thereby decreasing the turbulent drag.
McDonald, Samantha M; Liu, Jihong; Wilcox, Sara; Lau, Erica Y; Archer, Edward
2016-04-01
The purpose of this review was to examine the relationship between exercise dose and reductions in weight gain during pregnancy in exercise interventions. Systematic literature review. Four electronic research databases (PubMed, Web of Science, CINAHL, and Academic Search Premiere) were used to identify exercise interventions conducted with pregnant women. Eligible articles must have satisfied the following criteria: inclusion of a control condition, exercise as a major intervention component, weight gain measured and reported for each experimental condition, description of exercise dose (frequency, intensity and duration), and utilized an adequate number of control conditions to assess independent effects of exercise on weight gain. The literature search identified 4837 articles. Of these, 174 abstracts were screened and 21 intervention studies (18 exercise-only, 3 exercise/diet) were eligible for review. Only 38% of the interventions achieved statistically significant reductions in gestational weight gain. Successful interventions possessed higher adherence and lower attrition rates and were predominantly conducted among normal weight populations. No clear patterns or consistencies of exercise dose and reductions in weight gain were evident. An exercise dose associated with reductions in weight gain was unquantifiable among these interventions. Adherence and retention rates were strong contributors to the success of exercise interventions on gestational weight gain. It is strongly suggested that future researchers investigate methods to increase adherence and compliance, especially among overweight and obese women, and utilize objective measurement tools to accurately evaluate exercise dose performed by the participants and the impact on body composition and weight gain. Copyright © 2015 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.
Treatment of Obesity: Weight Loss and Bariatric Surgery
Wolfe, Bruce M.; Kvach, Elizaveta; Eckel, Robert H.
2016-01-01
This review focuses on the mechanisms underlying, and indications for, bariatric surgery in the reduction of cardiovascular disease (CVD) as well as other expected benefits of this intervention. The fundamental basis for bariatric surgery for the purpose of accomplishing weight loss is the determination that severe obesity is a disease associated with multiple adverse effects on health which can be reversed or improved by successful weight loss in patients who have been unable to sustain weight loss by non-surgical means. An explanation of possible indications for weight loss surgery as well as specific bariatric surgical procedures is presented, along with review of the safety literature of such procedures. Procedures that are less invasive or those that involve less gastrointestinal rearrangement accomplish considerably less weight loss but have substantially lower perioperative and longer-term risk. The ultimate benefit of weight reduction relates to the reduction of the co-morbidities, quality of life and all-cause mortality. With weight loss being the underlying justification for bariatric surgery in ameliorating CVD risk, current evidence-based research is discussed concerning body fat distribution, dyslipidemia, hypertension, diabetes, inflammation, obstructive sleep apnea and others. The rationale for bariatric surgery reducing CVD events is discussed and juxtaposed with impacts on all-cause mortalities. Given the improvement of established obesity-related CVD risk factors following weight loss, it is reasonable to expect a reduction of CVD events and related mortality following weight loss in populations with obesity. The quality of the current evidence is reviewed and future research opportunities and summaries are stated. PMID:27230645
Management of obesity in NIDDM (non-insulin-dependent diabetes mellitus).
Cheah, J S
1998-08-01
Obesity is common in NIDDM; in a cohort of 314 diabetics in Singapore, 44.3% are overweight. Management of obesity in diabetics differs from that in non-diabetics in that it is more urgent; weight maintenance is more difficult and hypoglycaemic medication may cause weight changes. Like in the non-diabetic, management of obesity in diabetic requires a pragmatic and realistic approach. A team approach is required: the help of the nurse educator, the dietitian, behaviour modification therapist, exercise therapist etc are required. A detailed history, careful physical examination and relevant investigations are required to assess the severity of the diabetic state and to exclude an occasional underlying cause of the obesity in the obese NIDDM. Weight loss is urgent in the obese NIDDM, especially those with android obesity. There must be a reduction in caloric intake. Weight loss leads to improvement in the glucose tolerance, insulin sensitivity, reduction in lipid levels and fall in blood pressure in the hypertensive. Exercise is of limited value except in the younger obese NIDDM. Metformin is the hypoglycaemic drug of choice as it leads to consistent weight reduction. The sulphonylureas may cause weight gain. Insulin should be avoided where possible as it causes further weight gain. Other hypoglycaemic agents include Glucobay (alpha-glucosidase inhibitor) and Troglitazone (insulin sensitizer) which do not alter the weight. Orlistat (lipase inhibitor) is promising as it causes reduction of weight, blood-glucose and lipid levels. Anti-obesity drugs (noradrenergic and serotonergic agents) have modest effects on weight reduction in the obese NIDDM; a widely use preparation, Dexfenfluramine (Adifax) has been withdrawn because of side effects. Surgery such as gastric plication is the last resort in treating the morbidly obese NIDDM. The discovery of leptin in 1994 has led to intense research into energy homeostasis in obesity; hopefully this will lead to better treatment of obesity in diabetics and non-diabetics.
Body Weight Gain and Hyperphagia After Administration of SGLT-2 Inhibitor: A Case Report.
Hamamoto, Hiromi; Noda, Mitsuhiko
2015-12-07
A detailed description is given of a case we encountered in which unexpectedly marked weight gain occurred following a treatment switch from a GLP-1 receptor agonist to an SGLT-2 inhibitor The patient, a 44-year-old man with type 2 diabetes mellitus, had gained about 10 kg in weight in the previous year. Therefore, metformin was replaced with liraglutide to obtain reduction of body weight. Although the patient lost about 8 kg (7%), during the 18-month period on the medication, the weight loss stabilized; therefore, the treatment was again switched to tofogliflozin to obtain further reduction of body weight. However, the patient reported increasing hunger and an exaggerated appetite from week 3 onward after the start of tofogliflozin, and gained about 9 kg in weight within 2 weeks, associated with a tendency towards increased HbA1c; therefore, tofogliflozin was discontinued. Immediate reinstitution of liraglutide resulted in reduction of the increased appetite, weight, and HbA1c level. Caution should be exercised against hyperphagia and weight gain due to hunger that may occur following discontinuation of a GLP-1 receptor agonist and/or initiation of an SGLT-2 inhibitor.
Polymer-surfactant complex formation and its effect on turbulent wall shear stress.
Suksamranchit, Siriluck; Sirivat, Anuvat; Jamieson, Alexander M
2006-02-01
Turbulent drag reduction in Couette flow was investigated in terms of a decrease in wall shear stress for aqueous solutions of a nonionic polymer, poly(ethylene oxide) (PEO), a cationic surfactant, hexadecyltrimethylammonium chloride (HTAC), and their mixtures. Consistent with literature data, drag reduction was observed for PEO solutions above a critical molecular weight, 0.91 x 10(5) < Mc < 3.04 x 10(5) g/mol. Maximum drag reduction occurred at an optimum concentration, c(PEO)*, which scales inversely with molecular weight, and the % maximum drag reduction increases with molecular weight. For aqueous HTAC solutions, wall shear stress decreased with increasing HTAC concentration and leveled off at an optimum concentration, c(HTAC)*, comparable to the critical micelle concentration. For HTAC/PEO mixtures, the critical PEO molecular weight for drag reduction decreases, interpreted as due to an increase in hydrodynamic volume because of binding of HTAC micelles to PEO. Consistent with this interpretation, at fixed PEO concentration, maximum drag reduction was observed at an optimum HTAC concentration, c(HTAC/PEO)*, comparable to the maximum binding concentration, MBC. Also, with HTAC concentration fixed at the MBC, the optimum PEO concentration for drag reduction, c(PEO/HTAC)*, decreases relative to that, c(PEO)*, in the absence of HTAC.
NASA Technical Reports Server (NTRS)
Goodall, R. G.; Painter, G. W.
1975-01-01
Conceptual nacelle designs for wide-bodied and for advanced-technology transports were studied with the objective of achieving significant reductions in community noise with minimum penalties in airplane weight, cost, and in operating expense by the application of advanced composite materials to nacelle structure and sound suppression elements. Nacelle concepts using advanced liners, annular splitters, radial splitters, translating centerbody inlets, and mixed-flow nozzles were evaluated and a preferred concept selected. A preliminary design study of the selected concept, a mixed flow nacelle with extended inlet and no splitters, was conducted and the effects on noise, direct operating cost, and return on investment determined.
The importance of obesity in diabetes and its treatment with sibutramine.
Van Gaal, L F; Peiffer, F W
2001-12-01
Weight gain is a known risk factor for the development of type 2 diabetes and even modest weight reduction can reduce the risk of developing diabetes, so controlling body weight is an important public health goal in the fight against diabetes and its comorbidities. Weight reduction is also a cornerstone of diabetes management, improving glycaemic control and reducing other risk factors associated with this disease. Pharmacotherapies such as sibutramine contribute to the management of type 2 diabetes in overweight and obese patients.
The FC-1D: The profitable alternative Flying Circus Commercial Aviation Group
NASA Technical Reports Server (NTRS)
Meza, Victor J.; Alvarez, Jaime; Harrington, Brook; Lujan, Michael A.; Mitlyng, David; Saroughian, Andy; Silva, Alex; Teale, Tim
1994-01-01
The FC-1D was designed as an advanced solution for a low cost commercial transport meeting or exceeding all of the 1993/1994 AIAA/Lockheed request for proposal requirements. The driving philosophy behind the design of the FC-1D was the reduction of airline direct operating costs. Every effort was made during the design process to have the customer in mind. The Flying Circus Commercial Aviation Group targeted reductions in drag, fuel consumption, manufacturing costs, and maintenance costs. Flying Circus emphasized cost reduction throughout the entire design program. Drag reduction was achieved by implementation of the aft nacelle wing configuration to reduce cruise drag and increase cruise speeds. To reduce induced drag, rather than increasing the wing span of the FC-1D, spiroids were included in the efficient wing design. Profile and friction drag are reduced by using riblets in place of paint around the fuselage and empennage of the FC-1D. Choosing a single aisle configuration enabled the Flying Circus to optimize the fuselage diameter. Thus, reducing fuselage drag while gaining high structural efficiency. To further reduce fuel consumption a weight reduction program was conducted through the use of composite materials. An additional quality of the FC-1D is its design for low cost manufacturing and assembly. As a result of this design attribute, the FC-1D will have fewer parts which reduces weight as well as maintenance and assembly costs. The FC-1D is affordable and effective, the apex of commercial transport design.
Long-Term Effects of Weight Loss and Exercise on Biomarkers Associated with Angiogenesis.
Duggan, Catherine; Tapsoba, Jean de Dieu; Wang, Ching-Yun; Schubert, Karen E Foster; McTiernan, Anne
2017-12-01
Background: We tested the effect of weight loss on circulating levels of the angiogenic factors VEGF and pigment epithelium-derived factor (PEDF) in postmenopausal overweight/obese women, 18 months after completing a year-long 4-arm randomized controlled trial of behavioral weight loss and/or exercise versus control (i.e., 30 months postrandomization). Methods: The 439 overweight/obese, postmenopausal women, ages 50 to 75 years, were randomized to: diet (goal: 10% weight loss, N = 118), exercise (225 min/wk moderate-to-vigorous activity, N = 117), diet + exercise ( N = 117), or control ( N = 87). At 12 months, 399 women gave a blood sample; 156 returned at 30 months. Biomarkers were measured by immunoassay. Changes were compared using generalized estimating equations, adjusting for baseline BMI, age, and race/ethnicity. Results: Participants randomized to diet, exercise, and diet + exercise arms had greater reductions in VEGF at 30 months (-14.1% P = 0.02; -19.7% P = 0.003; -14.5% P = 0.002, respectively) versus controls (-4.5%). There were no statistically significant changes in PEDF in any intervention arm. Participants maintaining ≥10% of baseline weight loss at 30 months had greater reductions in VEGF versus those who gained weight/had no weight change (-22.3% vs. -10.2% respectively, P = 0.002). Participants maintaining any weight loss had significantly lower levels of PEDF at 30 months versus those who gained weight/no weight change. Conclusions: Sustained weight loss via diet and/or exercise results in reductions in angiogenic factors, and can be maintained up to 30-month follow-up. Limitations include relatively small numbers, and possible bias toward more successful weight loss among women who returned at 30 months. Impact: Maintaining weight loss can achieve long-term reductions in biomarkers of angiogenesis that can persist up to 18 months after completion of a weight loss intervention. Cancer Epidemiol Biomarkers Prev; 26(12); 1788-94. ©2017 AACR . ©2017 American Association for Cancer Research.
Anti-spermatogenic activities of Taraxacum officinale whole plant and leaves aqueous extracts
Tahtamouni, Lubna Hamid; Al-Khateeb, Rema Ahmad; Abdellatif, Reem Nasser; Al-Mazaydeh, Zainab Ali; Yasin, Salem Refaat; Al-Gharabli, Samer; Elkarmi, Ali Zuhair
2016-01-01
Taraxacum officinale has been used in Jordan folk medicine to treat male infertility. A recent study has proved a contradictory effect of the whole plant aqueous extract. The aim of the current study was to determine if the leaves of T. officinale have similar anti-fertility activities, and whether this effect is mediated through the regulation of spermatogonial stem cells (SSCs). Fifty adult male rats were divided into five groups. Two groups were gavaged with 1/10 of LD50 of T. officinale whole plant (1.06 g kg-1 body weight) or leaves (2.30 g kg-1 body weight) aqueous extract; while two groups were gavaged with 1/20 of LD50 of T. officinale whole plant (2.13 g kg-1) or leaves (4.60 g kg-1) extract. The control group received distilled water. Oral administration of T. officinale (whole plant and leaves aqueous extract) caused a significant decrease in testis and seminal vesicle weight, a reduction in serum testosterone concentration, impaired sperm parameters, and a decrease in pregnancy parameters. Testicular histology of treated rats showed structural changes such as hypoplasia of germ cells, reduction in the thickness of germinal epithelium, arrest of spermatogenesis at spermatid stage (late maturation arrest) and reduction in the number of Leydig cells. Gene expression levels of two SSCs markers (GFRα1 and CSF1) responsible for self-renewal were relatively counter-balanced. In conclusion, T. officinale whole plant and leaves aqueous extracts changed the gene expression of two SSCs markers leading to the imbalance between spermatogonia self-renewal and differentiation causing late maturation arrest. PMID:27482352
Phisalprapa, Pochamana; Supakankunti, Siripen; Charatcharoenwitthaya, Phunchai; Apisarnthanarak, Piyaporn; Charoensak, Aphinya; Washirasaksiri, Chaiwat; Srivanichakorn, Weerachai; Chaiyakunapruk, Nathorn
2017-04-01
Nonalcoholic fatty liver disease (NAFLD) can be diagnosed early by noninvasive ultrasonography; however, the cost-effectiveness of ultrasonography screening with intensive weight reduction program in metabolic syndrome patients is not clear. This study aims to estimate economic and clinical outcomes of ultrasonography in Thailand. Cost-effectiveness analysis used decision tree and Markov models to estimate lifetime costs and health benefits from societal perspective, based on a cohort of 509 metabolic syndrome patients in Thailand. Data were obtained from published literatures and Thai database. Results were reported as incremental cost-effectiveness ratios (ICERs) in 2014 US dollars (USD) per quality-adjusted life year (QALY) gained with discount rate of 3%. Sensitivity analyses were performed to assess the influence of parameter uncertainty on the results. The ICER of ultrasonography screening of 50-year-old metabolic syndrome patients with intensive weight reduction program was 958 USD/QALY gained when compared with no screening. The probability of being cost-effective was 67% using willingness-to-pay threshold in Thailand (4848 USD/QALY gained). Screening before 45 years was cost saving while screening at 45 to 64 years was cost-effective. For patients with metabolic syndromes, ultrasonography screening for NAFLD with intensive weight reduction program is a cost-effective program in Thailand. Study can be used as part of evidence-informed decision making. Findings could contribute to changes of NAFLD diagnosis practice in settings where economic evidence is used as part of decision-making process. Furthermore, study design, model structure, and input parameters could also be used for future research addressing similar questions.
Gynecological efficacy and chemical investigation of Vitex agnus-castus L. fruits growing in Egypt.
Ibrahim, N A; Shalaby, A S; Farag, R S; Elbaroty, G S; Nofal, S M; Hassan, E M
2008-04-15
Flavonoid glycosides, orientin and apigenin 3, 8-di-C-glycosides in addition to, iridoid compound, aucubin were isolated from the ethanolic extract of Vitex agnus-castus fruits. Their structures were identified on the basis of the spectroscopic data. The estrogenic activity of the ethanolic extract in two dose levels 0.6 and 1.2 g kg(-1) per body weight (b.w.) was studied by the vaginal smear, and uterine weight methods for normal and ovariectomized female rats. The extract induced significant increase in the uterine weight of ovariectomized rats at two dose levels comparable to that of control group. The percentages of the total average number of scores were increased significantly too. Significant increases in plasma progesterone and total estrogens levels were shown at the two dose levels when compared to that of control group. On the other side, the extract induced significant reduction in luteinizing and plasma prolactin hormones.
NASA Technical Reports Server (NTRS)
Regan, Christopher D.; Jutte, Christine V.
2012-01-01
This report provides a historical survey and assessment of the state of the art in the modeling and application of active control to aircraft encountering atmospheric disturbances in flight. Particular emphasis is placed on applications of active control technologies that enable weight reduction in aircraft by mitigating the effects of atmospheric disturbances. Based on what has been learned to date, recommendations are made for addressing gust alleviation on as the trend for more structurally efficient aircraft yields both lighter and more flexible aircraft. These lighter more flexible aircraft face two significant challenges reduced separation between rigid body and flexible modes, and increased sensitivity to gust encounters due to increased wing loading and improved lift to drag ratios. The primary audience of this paper is engineering professionals new to the area of gust load alleviation and interested in tackling the multifaceted challenges that lie ahead for lighter-weight aircraft.
Proteolytic enzyme engineering: a tool for wool.
Araújo, Rita; Silva, Carla; Machado, Raul; Casal, Margarida; Cunha, António M; Rodriguez-Cabello, José Carlos; Cavaco-Paulo, Artur
2009-06-08
One of the goals of protein engineering is to tailor the structure of enzymes to optimize industrial bioprocesses. In the present work, we present the construction of a novel high molecular weight subtilisin, based on the fusion of the DNA sequences coding for Bacillus subtilis prosubtilisin E and for an elastin-like polymer (ELP). The resulting fusion protein was biologically produced in Escherichia coli , purified and used for wool finishing assays. When compared to the commercial protease Esperase, the recombinant subtilisinE-VPAVG(220) activity was restricted to the cuticle of wool, allowing a significant reduction of pilling, weight loss and tensile strength loss of wool fibers. Here we report, for the first time, the microbial production of a functionalized high molecular weight protease for controlled enzymatic hydrolysis of wool surface. This original process overcomes the unrestrained diffusion and extended fiber damage which are the major obstacles for the use of proteases for wool finishing applications.
Premature Brain Aging in Baboons Resulting from Moderate Fetal Undernutrition.
Franke, Katja; Clarke, Geoffrey D; Dahnke, Robert; Gaser, Christian; Kuo, Anderson H; Li, Cun; Schwab, Matthias; Nathanielsz, Peter W
2017-01-01
Contrary to the known benefits from a moderate dietary reduction during adulthood on life span and health, maternal nutrient reduction during pregnancy is supposed to affect the developing brain, probably resulting in impaired brain structure and function throughout life. Decreased fetal nutrition delivery is widespread in both developing and developed countries, caused by poverty and natural disasters, but also due to maternal dieting, teenage pregnancy, pregnancy in women over 35 years of age, placental insufficiency, or multiples. Compromised development of fetal cerebral structures was already shown in our baboon model of moderate maternal nutrient reduction. The present study was designed to follow-up and evaluate the effects of moderate maternal nutrient reduction on individual brain aging in the baboon during young adulthood (4-7 years; human equivalent 14-24 years), applying a novel, non-invasive neuroimaging aging biomarker. The study reveals premature brain aging of +2.7 years ( p < 0.01) in the female baboon exposed to fetal undernutrition. The effects of moderate maternal nutrient reduction on individual brain aging occurred in the absence of fetal growth restriction or marked maternal weight reduction at birth, which stresses the significance of early nutritional conditions in life-long developmental programming. This non-invasive MRI biomarker allows further longitudinal in vivo tracking of individual brain aging trajectories to assess the life-long effects of developmental and environmental influences in programming paradigms, aiding preventive and curative treatments on cerebral atrophy in experimental animal models and humans.
Premature Brain Aging in Baboons Resulting from Moderate Fetal Undernutrition
Franke, Katja; Clarke, Geoffrey D.; Dahnke, Robert; Gaser, Christian; Kuo, Anderson H.; Li, Cun; Schwab, Matthias; Nathanielsz, Peter W.
2017-01-01
Contrary to the known benefits from a moderate dietary reduction during adulthood on life span and health, maternal nutrient reduction during pregnancy is supposed to affect the developing brain, probably resulting in impaired brain structure and function throughout life. Decreased fetal nutrition delivery is widespread in both developing and developed countries, caused by poverty and natural disasters, but also due to maternal dieting, teenage pregnancy, pregnancy in women over 35 years of age, placental insufficiency, or multiples. Compromised development of fetal cerebral structures was already shown in our baboon model of moderate maternal nutrient reduction. The present study was designed to follow-up and evaluate the effects of moderate maternal nutrient reduction on individual brain aging in the baboon during young adulthood (4–7 years; human equivalent 14–24 years), applying a novel, non-invasive neuroimaging aging biomarker. The study reveals premature brain aging of +2.7 years (p < 0.01) in the female baboon exposed to fetal undernutrition. The effects of moderate maternal nutrient reduction on individual brain aging occurred in the absence of fetal growth restriction or marked maternal weight reduction at birth, which stresses the significance of early nutritional conditions in life-long developmental programming. This non-invasive MRI biomarker allows further longitudinal in vivo tracking of individual brain aging trajectories to assess the life-long effects of developmental and environmental influences in programming paradigms, aiding preventive and curative treatments on cerebral atrophy in experimental animal models and humans. PMID:28443017
NASA Astrophysics Data System (ADS)
Volkov, Boris; Mathews, Marlon S.; Abookasis, David
2015-03-01
Multispectral imaging has received significant attention over the last decade as it integrates spectroscopy, imaging, tomography analysis concurrently to acquire both spatial and spectral information from biological tissue. In the present study, a multispectral setup based on projection of structured illumination at several near-infrared wavelengths and at different spatial frequencies is applied to quantitatively assess brain function before, during, and after the onset of traumatic brain injury in an intact mouse brain (n=5). For the production of head injury, we used the weight drop method where weight of a cylindrical metallic rod falling along a metal tube strikes the mouse's head. Structured light was projected onto the scalp surface and diffuse reflected light was recorded by a CCD camera positioned perpendicular to the mouse head. Following data analysis, we were able to concurrently show a series of hemodynamic and morphologic changes over time including higher deoxyhemoglobin, reduction in oxygen saturation, cell swelling, etc., in comparison with baseline measurements. Overall, results demonstrates the capability of multispectral imaging based structured illumination to detect and map of brain tissue optical and physiological properties following brain injury in a simple noninvasive and noncontact manner.
Bak-Sosnowska, Monika; Zahorska-Markiewicz, Barbara; Bargiel-Matusiewicz, Kamilla
2004-01-01
Psychological factors may contribute in creating and maintaining of overweight that often results of disturbances of individual's psychosocial functioning. That is why psychological impact should be a significant element of both obesity treatment and prevention of recurrence. The article presents a project implemented in the Obesity Treatment Centre "Waga" in Katowice. The project acts as a part of a group, complex treatment process leading to weight reduction. Design, target group and the achieved results are presented as well a psychological aspects helping the process of reduction of body weight.
Sobell, Mark B; Peterson, Alan L; Sobell, Linda Carter; Brundige, Antoinette; Hunter, Christopher M; Hunter, Christine M; Goodie, Jeffrey L; Agrawal, Sangeeta; Hrysko-Mullen, Ann S; Isler, William C
2017-12-01
Smoking cessation-related weight gain can have significant negative health and career consequences for military personnel. Alcohol reduction combined with smoking cessation may decrease weight gain and relapse. A randomized clinical trial of military beneficiaries compared a standard smoking cessation (i.e., brief informational) intervention (N=159), with a brief motivational smoking cessation intervention that emphasized reduced drinking to lessen caloric intake and minimize weight gain (N=158). Participants who received the motivational intervention were significantly more likely to quit smoking at the 3-month follow-up (p=0.02), but the differences were not maintained at 6 (p=0.18) or 12months (p=0.16). Neither weight change nor alcohol reduction distinguished the 2 groups. Smoking cessation rates at 12months (motivational group=32.91%, informational group=25.79%) were comparable to previous studies, but successful cessation was not mediated by reduced drinking. Alcohol reduction combined with smoking cessation did not result in decreased weight gain or improved outcomes. Copyright © 2017. Published by Elsevier Ltd.
Global warming: is weight loss a solution?
Gryka, A; Broom, J; Rolland, C
2012-03-01
The current climate change has been most likely caused by the increased greenhouse gas emissions. We have looked at the major greenhouse gas, carbon dioxide (CO(2)), and estimated the reduction in the CO(2) emissions that would occur with the theoretical global weight loss. The calculations were based on our previous weight loss study, investigating the effects of a low-carbohydrate diet on body weight, body composition and resting metabolic rate of obese volunteers with type 2 diabetes. At 6 months, we observed decreases in weight, fat mass, fat free mass and CO(2) production. We estimated that a 10 kg weight loss of all obese and overweight people would result in a decrease of 49.560 Mt of CO(2) per year, which would equal to 0.2% of the CO(2) emitted globally in 2007. This reduction could help meet the CO(2) emission reduction targets and unquestionably would be of a great benefit to the global health.
NASA Astrophysics Data System (ADS)
Kenway, Gaetan K. W.
This thesis presents new tools and techniques developed to address the challenging problem of high-fidelity aerostructural optimization with respect to large numbers of design variables. A new mesh-movement scheme is developed that is both computationally efficient and sufficiently robust to accommodate large geometric design changes and aerostructural deformations. A fully coupled Newton-Krylov method is presented that accelerates the convergence of aerostructural systems and provides a 20% performance improvement over the traditional nonlinear block Gauss-Seidel approach and can handle more exible structures. A coupled adjoint method is used that efficiently computes derivatives for a gradient-based optimization algorithm. The implementation uses only machine accurate derivative techniques and is verified to yield fully consistent derivatives by comparing against the complex step method. The fully-coupled large-scale coupled adjoint solution method is shown to have 30% better performance than the segregated approach. The parallel scalability of the coupled adjoint technique is demonstrated on an Euler Computational Fluid Dynamics (CFD) model with more than 80 million state variables coupled to a detailed structural finite-element model of the wing with more than 1 million degrees of freedom. Multi-point high-fidelity aerostructural optimizations of a long-range wide-body, transonic transport aircraft configuration are performed using the developed techniques. The aerostructural analysis employs Euler CFD with a 2 million cell mesh and a structural finite element model with 300 000 DOF. Two design optimization problems are solved: one where takeoff gross weight is minimized, and another where fuel burn is minimized. Each optimization uses a multi-point formulation with 5 cruise conditions and 2 maneuver conditions. The optimization problems have 476 design variables are optimal results are obtained within 36 hours of wall time using 435 processors. The TOGW minimization results in a 4.2% reduction in TOGW with a 6.6% fuel burn reduction, while the fuel burn optimization resulted in a 11.2% fuel burn reduction with no change to the takeoff gross weight.
Magnetic shielding structure optimization design for wireless power transmission coil
NASA Astrophysics Data System (ADS)
Dai, Zhongyu; Wang, Junhua; Long, Mengjiao; Huang, Hong; Sun, Mingui
2017-09-01
In order to improve the performance of the wireless power transmission (WPT) system, a novel design scheme with magnetic shielding structure on the WPT coil is presented in this paper. This new type of shielding structure has great advantages on magnetic flux leakage reduction and magnetic field concentration. On the basis of theoretical calculation of coil magnetic flux linkage and characteristic analysis as well as practical application feasibility consideration, a complete magnetic shielding structure was designed and the whole design procedure was represented in detail. The simulation results show that the coil with the designed shielding structure has the maximum energy transmission efficiency. Compared with the traditional shielding structure, the weight of the new design is significantly decreased by about 41%. Finally, according to the designed shielding structure, the corresponding experiment platform is built to verify the correctness and superiority of the proposed scheme.
Schizophrenia and weight management: a systematic review of interventions to control weight.
Faulkner, G; Soundy, A A; Lloyd, K
2003-11-01
Weight gain is a frequent side effect of antipsychotic medication which has serious implications for a patient's health and well being. This study systematically reviews the literature on the effectiveness of interventions designed to control weight gain in schizophrenia. A systematic search strategy was conducted of major databases in addition to citation searches. Study quality was rated. Sixteen studies met the inclusion criteria. Five of eight pharmacological intervention studies reported small reductions in weight (<5% baseline body weight). All behavioural (including diet and/or exercise) interventions reported small reductions in, or maintenance of, weight. Weight loss may be difficult but it is not impossible. Given the inconsistent results, the widespread use of pharmacological interventions cannot be recommended. Both dietary and exercise counselling set within a behavioural modification programme is necessary for sustained weight control.
Schnell, Oliver; Weng, Jianping; Sheu, Wayne H-H; Watada, Hirotaka; Kalra, Sanjay; Soegondo, Sidartawan; Yamamoto, Noriyuki; Rathod, Rahul; Zhang, Cheryl; Grzeszczak, Wladyslaw
2016-01-01
The objective of this study is to examine the effect of acarbose, an alpha-glucosidase inhibitor, on body weight in a real-life setting by pooling data from post-marketing surveillance. Data from 10 studies were pooled (n=67,682) and the effect of acarbose on body weight was analysed taking into account baseline body weight, glycemic parameters and other baseline characteristics. The mean relative reduction in body weight was 1.45 ± 3.24% at the 3-month visit (n=43,510; mean baseline 73.4 kg) and 1.40 ± 3.28% at the last visit (n=54,760; mean baseline 73.6 kg) (both p<0.0001). These reductions were dependent on baseline body weight (overweight: -1.33 ± 2.98% [n=13,498; mean baseline 71.6 kg]; obese: -1.98 ± 3.40% [n=20,216; mean baseline 81.3 kg]). When analysed by baseline glycemic parameter quartiles, the reduction was independent of fasting plasma glucose (FPG), postprandial plasma glucose (PPG), glycated hemoglobin (HbA1c) and postprandial glucose excursion (PPGE). A bivariate analysis of covariance identified female sex, South East Asian and East Asian ethnicity, younger age, higher body mass index, short duration of diabetes, and no previous treatment as factors likely to impact positively on body weight reduction with acarbose. This post-hoc analysis showed that acarbose treatment reduces body weight independent of glycemic control status but dependent on baseline body weight. Copyright © 2016. Published by Elsevier Inc.
Next-Generation MKIII Lightweight HUT/Hatch Assembly
NASA Technical Reports Server (NTRS)
McCarthy, Mike; Toscano, Ralph
2013-01-01
The MK III (H-1) carbon-graphite/ epoxy Hard Upper Torso (HUT)/Hatch assembly was designed, fabricated, and tested in the early 1990s. The spacesuit represented an 8.3 psi (˜58 kPa) technology demonstrator model of a zero prebreathe suit. The basic torso shell, brief, and hip areas of the suit were composed of a carbon-graphite/epoxy composite lay-up. In its current configuration, the suit weighs approximately 120 lb (˜54 kg). However, since future planetary suits will be designed to operate at 0.26 bar (˜26 kPa), it was felt that the suit's re-designed weight could be reduced to 79 lb (˜35 kg) with the incorporation of lightweight structural materials. Many robust, lightweight structures based on the technologies of advanced honeycomb materials, revolutionary new composite laminates, metal matrix composites, and recent breakthroughs in fullerene fillers and nanotechnology lend themselves well to applications requiring materials that are both light and strong. The major problem involves the reduction in weight of the HUT/ Hatch assembly for use in lunar and/or planetary applications, while at the same time maintaining a robust structural design. The technical objective is to research, design, and develop manufacturing methods that support fa b rica - tion of a lightweight HUT/Hatch assembly using advanced material and geometric redesign as necessary. Additionally, the lightweight HUT/Hatch assembly will interface directly with current MK III hardware. Using the new operating pressure and current MK III (H-1) interfaces as a starting block, it is planned to maximize HUT/Hatch assembly weight reduction through material selection and geometric redesign. A hard upper torso shell structure with rear-entry closure and corresponding hatch will be fabricated. The lightweight HUT/Hatch assembly will retrofit and interface with existing MK III (H-1) hardware elements, providing NASA with immediate "plug-andplay" capability. NASA crewmembers will have a lightweight, robust, life-support system that will minimize fatigue during extraterrestrial surface sojourns. Its unique feature is the utilization of a new and innovative family of materials used by the aerospace industry, which at the time of this reporting has not been used for the proposed application.
Wieser, Herbert
2007-04-01
Gluten proteins play a key role in determining the unique baking quality of wheat by conferring water absorption capacity, cohesivity, viscosity and elasticity on dough. Gluten proteins can be divided into two main fractions according to their solubility in aqueous alcohols: the soluble gliadins and the insoluble glutenins. Both fractions consist of numerous, partially closely related protein components characterized by high glutamine and proline contents. Gliadins are mainly monomeric proteins with molecular weights (MWs) around 28,000-55,000 and can be classified according to their different primary structures into the alpha/beta-, gamma- and omega-type. Disulphide bonds are either absent or present as intrachain crosslinks. The glutenin fraction comprises aggregated proteins linked by interchain disulphide bonds; they have a varying size ranging from about 500,000 to more than 10 million. After reduction of disulphide bonds, the resulting glutenin subunits show a solubility in aqueous alcohols similar to gliadins. Based on primary structure, glutenin subunits have been divided into the high-molecular-weight (HMW) subunits (MW=67,000-88,000) and low-molecular-weight (LMW) subunits (MW=32,000-35,000). Each gluten protein type consists or two or three different structural domains; one of them contains unique repetitive sequences rich in glutamine and proline. Native glutenins are composed of a backbone formed by HMW subunit polymers and of LMW subunit polymers branched off from HMW subunits. Non-covalent bonds such as hydrogen bonds, ionic bonds and hydrophobic bonds are important for the aggregation of gliadins and glutenins and implicate structure and physical properties of dough.
NASA Technical Reports Server (NTRS)
Ippolito, Corey; Nguyen, Nhan; Totah, Joe; Trinh, Khanh; Ting, Eric
2013-01-01
In this paper, we describe an initial optimization study of a Variable-Camber Continuous Trailing-Edge Flap (VCCTEF) system. The VCCTEF provides a light-weight control system for aircraft with long flexible wings, providing efficient high-lift capability for takeoff and landing, and greater efficiency with reduced drag at cruising flight by considering the effects of aeroelastic wing deformations in the control law. The VCCTEF system is comprised of a large number of distributed and individually-actuatable control surfaces that are constrained in movement relative to neighboring surfaces, and are non-trivially coupled through structural aeroelastic dynamics. Minimzation of drag results in a constrained, coupled, non-linear optimization over a high-dimension search space. In this paper, we describe the modeling, analysis, and optimization of the VCCTEF system control inputs for minimum drag in cruise. The purpose of this initial study is to quantify the expected benefits of the system concept. The scope of this analysis is limited to consideration of a rigid wing without structural flexibility in a steady-state cruise condition at various fuel weights. For analysis, we developed an optimization engine that couples geometric synthesis with vortex-lattice analysis to automate the optimization procedure. In this paper, we present and describe the VCCTEF system concept, optimization approach and tools, run-time performance, and results of the optimization at 20%, 50%, and 80% fuel load. This initial limited-scope study finds the VCCTEF system can potentially gain nearly 10% reduction in cruise drag, provides greater drag savings at lower operating weight, and efficiency is negatively impacted by the severity of relative constraints between control surfaces.
NASA Astrophysics Data System (ADS)
Parekh, Vishwa S.; Jacobs, Jeremy R.; Jacobs, Michael A.
2014-03-01
The evaluation and treatment of acute cerebral ischemia requires a technique that can determine the total area of tissue at risk for infarction using diagnostic magnetic resonance imaging (MRI) sequences. Typical MRI data sets consist of T1- and T2-weighted imaging (T1WI, T2WI) along with advanced MRI parameters of diffusion-weighted imaging (DWI) and perfusion weighted imaging (PWI) methods. Each of these parameters has distinct radiological-pathological meaning. For example, DWI interrogates the movement of water in the tissue and PWI gives an estimate of the blood flow, both are critical measures during the evolution of stroke. In order to integrate these data and give an estimate of the tissue at risk or damaged; we have developed advanced machine learning methods based on unsupervised non-linear dimensionality reduction (NLDR) techniques. NLDR methods are a class of algorithms that uses mathematically defined manifolds for statistical sampling of multidimensional classes to generate a discrimination rule of guaranteed statistical accuracy and they can generate a two- or three-dimensional map, which represents the prominent structures of the data and provides an embedded image of meaningful low-dimensional structures hidden in their high-dimensional observations. In this manuscript, we develop NLDR methods on high dimensional MRI data sets of preclinical animals and clinical patients with stroke. On analyzing the performance of these methods, we observed that there was a high of similarity between multiparametric embedded images from NLDR methods and the ADC map and perfusion map. It was also observed that embedded scattergram of abnormal (infarcted or at risk) tissue can be visualized and provides a mechanism for automatic methods to delineate potential stroke volumes and early tissue at risk.
Neonatal handling reduces renal function in adult rats.
Donadio, Márcio Vinícius Fagundes; Jacobs, Silvana; Corezola, Kizzy Ludnila; Melo, Denizar Alberto da Silva; Dias, Henrique Bregolin; Reichel, Carlos Luiz; Franci, Celso Rodrigues; Jeckel-Neto, Emilio Antonio; Lulhier, Francisco; Lucion, Aldo Bolten; de Oliveira, Jarbas Rodrigues; Sanvitto, Gilberto Luiz
2009-01-01
To evaluate the effects of neonatal handling on hydroelectrolytic balance in adult rats. The litters were divided into two groups: nonhandled and handled. The procedure consisted of handling the pups for 1 min/day in the first 10 days postnatally. When adults, animals had their body weight verified and were housed in individual metabolic cages. After a 24-hour period, urine samples were collected and the urinary and water intake volumes measured. Blood samples to determine osmolality, aldosterone, corticosterone, angiotensin II, creatinine, urea, sodium and potassium levels were collected. The kidneys were removed for histological assessment. Urinary osmolality, sodium, urea and creatinine were also measured and the creatinine clearance (CC) calculated. No difference between groups was found in the body weight. Handled animals showed a reduction in the total kidney wet weight, water intake, urinary volume, CC, plasma angiotensin II, corticosterone and aldosterone when compared to the nonhandled and an increase in the urinary osmolality and sodium excretion fraction. No differences in serum potassium and no evidence of structural changes were demonstrated by histological analysis. Neonatal handling induced long-lasting effects decreasing renal function without evidence of kidney structural changes. (c) 2009 S. Karger AG, Basel.
Lee, I-Te; Wang, Jun-Sing; Fu, Chia-Po; Lin, Shih-Yi; Sheu, Wayne Huey-Herng
2016-10-01
Brain-derived neurotrophic factor (BDNF) plays a role in energy homeostasis. However, the postprandial BDNF change has not been well investigated. We hypothesized that the BDNF increment after oral glucose challenge is associated with body weight.To address this possibility, man adults with obesity in conjunction with metabolic syndrome were compared with normal weight controls at baseline in the initial cross-sectional protocol. The obese subjects then underwent a 12-week program for body-weight reduction in the prospective protocol. The area under the curve (AUC) of serum BDNF was recorded during a 75 g oral glucose tolerant test and the BDNF AUC index was defined as [(AUC of BDNF) - (fasting BDNF2 hours)]/(fasting BDNF2 hours).A total of 25 controls and 36 obese subjects completed the study assessments. In the cross-sectional protocol, the BDNF AUC index was significantly higher in the obese subjects than in the controls (9.0 ± 16.5% vs. - 8.0 ± 22.5%, P = 0.001). After weight reduction (from 97.0 ± 12.5 kg to 88.6 ± 12.9 kg, P < 0.001), the percentage change of body weight was significantly associated with the BDNF AUC index after the study (95% CI between 0.21 and 1.82, P = 0.015). Using 6% weight reduction as a cut-off value, a larger weight reduction was able to reliably predict a negative BDNF AUC index.In conclusion, a high BDNF AUC index was observed for obese men in this study, whereas the index value significantly decreased after body-weight reduction. These findings suggest that postprandial BDNF increment may be associated with obesity.
Lee, I-Te; Wang, Jun-Sing; Fu, Chia-Po; Lin, Shih-Yi; Sheu, Wayne Huey-Herng
2016-01-01
Abstract Brain-derived neurotrophic factor (BDNF) plays a role in energy homeostasis. However, the postprandial BDNF change has not been well investigated. We hypothesized that the BDNF increment after oral glucose challenge is associated with body weight. To address this possibility, man adults with obesity in conjunction with metabolic syndrome were compared with normal weight controls at baseline in the initial cross-sectional protocol. The obese subjects then underwent a 12-week program for body-weight reduction in the prospective protocol. The area under the curve (AUC) of serum BDNF was recorded during a 75 g oral glucose tolerant test and the BDNF AUC index was defined as [(AUC of BDNF) − (fasting BDNF∗2 hours)]/(fasting BDNF∗2 hours). A total of 25 controls and 36 obese subjects completed the study assessments. In the cross-sectional protocol, the BDNF AUC index was significantly higher in the obese subjects than in the controls (9.0 ± 16.5% vs. − 8.0 ± 22.5%, P = 0.001). After weight reduction (from 97.0 ± 12.5 kg to 88.6 ± 12.9 kg, P < 0.001), the percentage change of body weight was significantly associated with the BDNF AUC index after the study (95% CI between 0.21 and 1.82, P = 0.015). Using 6% weight reduction as a cut-off value, a larger weight reduction was able to reliably predict a negative BDNF AUC index. In conclusion, a high BDNF AUC index was observed for obese men in this study, whereas the index value significantly decreased after body-weight reduction. These findings suggest that postprandial BDNF increment may be associated with obesity. PMID:27787389
Optimization of flexible wing structures subject to strength and induced drag constraints
NASA Technical Reports Server (NTRS)
Haftka, R. T.
1977-01-01
An optimization procedure for designing wing structures subject to stress, strain, and drag constraints is presented. The optimization method utilizes an extended penalty function formulation for converting the constrained problem into a series of unconstrained ones. Newton's method is used to solve the unconstrained problems. An iterative analysis procedure is used to obtain the displacements of the wing structure including the effects of load redistribution due to the flexibility of the structure. The induced drag is calculated from the lift distribution. Approximate expressions for the constraints used during major portions of the optimization process enhance the efficiency of the procedure. A typical fighter wing is used to demonstrate the procedure. Aluminum and composite material designs are obtained. The tradeoff between weight savings and drag reduction is investigated.
3D Printing Variable Stiffness Foams Using Viscous Thread Instability
NASA Astrophysics Data System (ADS)
Lipton, Jeffrey I.; Lipson, Hod
2016-08-01
Additive manufacturing of cellular structures has numerous applications ranging from fabrication of biological scaffolds and medical implants, to mechanical weight reduction and control over mechanical properties. Various additive manufacturing processes have been used to produce open regular cellular structures limited only by the resolution of the printer. These efforts have focused on printing explicitly designed cells or explicitly planning offsets between strands. Here we describe a technique for producing cellular structures implicitly by inducing viscous thread instability when extruding material. This process allows us to produce complex cellular structures at a scale that is finer than the native resolution of the printer. We demonstrate tunable effective elastic modulus and density that span two orders of magnitude. Fine grained cellular structures allow for fabrication of foams for use in a wide range of fields ranging from bioengineering, to robotics to food printing.
NASA Astrophysics Data System (ADS)
Ialongo, S.; Cella, F.; Fedi, M.; Florio, G.
2011-12-01
Most geophysical inversion problems are characterized by a number of data considerably higher than the number of the unknown parameters. This corresponds to solve highly underdetermined systems. To get a unique solution, a priori information must be therefore introduced. We here analyze the inversion of the gravity gradient tensor (GGT). Previous approaches to invert jointly or independently more gradient components are by Li (2001) proposing an algorithm using a depth weighting function and Zhdanov et alii (2004), providing a well focused inversion of gradient data. Both the methods give a much-improved solution compared with the minimum length solution, which is invariably shallow and not representative of the true source distribution. For very undetermined problems, this feature is due to the role of the depth weighting matrices used by both the methods. Recently, Cella and Fedi (2011) showed however that for magnetic and gravity data the depth weighting function has to be defined carefully, under a preliminary application of Euler Deconvolution or Depth from Extreme Point methods, yielding the appropriate structural index and then using it as the rate decay of the weighting function. We therefore propose to extend this last approach to invert jointly or independently the GGT tensor using the structural index as weighting function rate decay. In case of a joint inversion, gravity data can be added as well. This multicomponent case is also relevant because the simultaneous use of several components and gravity increase the number of data and reduce the algebraic ambiguity compared to the inversion of a single component. The reduction of such ambiguity was shown in Fedi et al, (2005) decisive to get an improved depth resolution in inverse problems, independently from any form of depth weighting function. The method is demonstrated to synthetic cases and applied to real cases, such as the Vredefort impact area (South Africa), characterized by a complex density distribution, well defining a central uplift area, ring structures and low density sediments. REFERENCES Cella F., and Fedi M., 2011, Inversion of potential field data using the structural index as weighting function rate decay, Geophysical Prospecting, doi: 10.1111/j.1365-2478.2011.00974.x Fedi M., Hansen P. C., and Paoletti V., 2005 Analysis of depth resolution in potential-field inversion. Geophysics, 70, NO. 6 Li, Y., 2001, 3-D inversion of gravity gradiometry data: 71st Annual Meeting, SEG, Expanded Abstracts, 1470-1473. Zhdanov, M. S., Ellis, R. G., and Mukherjee, S., 2004, Regularized focusing inversion of 3-D gravity tensor data: Geophysics, 69, 925-937.
Bashier, Alaaeldin M; Abdelgadir, Elamin I; Khalifa, Azza A; Rashid, Fouzia; Abuelkeir, Sona M; Bachet, Fawzi E
2014-11-01
To determine whether exenatide is effective in reducing weight and glycosylated hemoglobin level (HbA1c), and to investigate its efficacy in improving lipid profile, blood pressure, and creatinine levels in the Arab population. This study was conducted at the Endocrine Unit, Dubai Hospital, Dubai, United Arab Emirates. We retrospectively collected data from patients with type 2 diabetes started on exenatide between November 2011 and February 2012. Data included demographics, clinical, laboratory results, and medications used. A general linear model adjusted by baseline characteristics (weight, HbA1C, age, use of statins, and duration of diabetes) was used to assess changes between baseline and end of trial in HbA1C, weight, low density lipoprotein cholesterol, total cholesterol, triglycerides, creatinine, and blood pressure. After 6 months of treatment with exenatide, the HbA1c decreased by 0.47% (95% confidence level [CI]: -0.01 - 0.95) (p=0.055). Weight reduction was highly significant; 5.6 kg (95% CI: 3.34 - 7.85) (p<0.001). Those reductions remained significant after adjustment for confounding factors. This study showed that weight reduction was highly significant with exenatide. The borderline significance in HbA1c reduction can be attributed to the small sample size.
Stelmach-Mardas, Marta; Mardas, Marcin; Warchoł, Wojciech; Jamka, Małgorzata; Walkowiak, Jarosław
2014-01-01
The aim of this study was to describe the effectiveness of individualized dietary counseling in obese subjects based on narrative interview technique on the maintenance of body weight reduction, changes in dietary behaviors, including type of cooking and physical activity. One-hundred subjects out of four-hundred patients met the inclusion criteria. Individually, 45-minute educational program with motivation counseling was performed in 0, 6 and 12 weeks of the study. Patients were advised to follow individually well-balanced diet for 12 weeks. The individuals were asked about the changes in their dietary habits (Food Frequency Questionnaire). The mean percentage of body weight changes from the baseline were as follows: in 6th week- 5.9%, in 12th week - 10.9% and in 52th week - 9.7% (P < 0.0001), however there were no statistically significant changes while comparing body weight in 12th and 52th week. The maintenance of body weight reduction was connected with the dietary habits changes, mainly the type of cooking and increased consumption of vegetable oils. In conclusion, individualized dietary counseling, based on narrative interview technique is an effective intervention for obesity treatment that may help maintain body weight reduction and adapt the pro-healthy changes in type of cooking and sources of dietary fat. PMID:25311271
Stelmach-Mardas, Marta; Mardas, Marcin; Warchoł, Wojciech; Jamka, Małgorzata; Walkowiak, Jarosław
2014-10-14
The aim of this study was to describe the effectiveness of individualized dietary counseling in obese subjects based on narrative interview technique on the maintenance of body weight reduction, changes in dietary behaviors, including type of cooking and physical activity. One-hundred subjects out of four-hundred patients met the inclusion criteria. Individually, 45-minute educational program with motivation counseling was performed in 0, 6 and 12 weeks of the study. Patients were advised to follow individually well-balanced diet for 12 weeks. The individuals were asked about the changes in their dietary habits (Food Frequency Questionnaire). The mean percentage of body weight changes from the baseline were as follows: in 6th week- 5.9%, in 12th week - 10.9% and in 52th week - 9.7% (P < 0.0001), however there were no statistically significant changes while comparing body weight in 12th and 52th week. The maintenance of body weight reduction was connected with the dietary habits changes, mainly the type of cooking and increased consumption of vegetable oils. In conclusion, individualized dietary counseling, based on narrative interview technique is an effective intervention for obesity treatment that may help maintain body weight reduction and adapt the pro-healthy changes in type of cooking and sources of dietary fat.
Stability characteristics of compressible boundary layers over thermo-mechanically compliant walls
NASA Astrophysics Data System (ADS)
Dettenrieder, Fabian; Bodony, Daniel
2017-11-01
Transition prediction at hypersonic flight conditions continues to be a challenge and results in conservative safety factors that increase vehicle weight. The weight and thus cost reduction of the outer skin panels promises significant impact; however, fluid-structure interaction due to unsteady perturbations in the laminar boundary layer regime has not been systematically studied at conditions relevant for reusable, hypersonic flight. In this talk, we develop and apply convective and global stability analyses for compressible boundary layers over thermo-mechanically compliant panels. This compliance is shown to change the convective stability of the boundary layer modes, with both stabilization and destabilization observed. Finite panel lengths are shown to affect the global stability properties of the boundary layer.
Conrad, Chelsie E.; Nelson, Garrett; Stander, Natasha; Zatsepin, Nadia A.; Zook, James; Zhu, Lan; Geiger, James; Chun, Eugene; Kissick, David; Hilgart, Mark C.; Ogata, Craig; Ishchenko, Andrii; Nagaratnam, Nirupa; Roy-Chowdhury, Shatabdi; Coe, Jesse; Subramanian, Ganesh; Schaffer, Alexander; Ketwala, Gihan; Venugopalan, Nagarajan; Xu, Shenglan; Corcoran, Stephen; Ferguson, Dale; Weierstall, Uwe; Spence, John C. H.; Cherezov, Vadim; Fromme, Petra; Fischetti, Robert F.; Liu, Wei
2017-01-01
Crystal structure determination of biological macromolecules using the novel technique of serial femtosecond crystallography (SFX) is severely limited by the scarcity of X-ray free-electron laser (XFEL) sources. However, recent and future upgrades render microfocus beamlines at synchrotron-radiation sources suitable for room-temperature serial crystallography data collection also. Owing to the longer exposure times that are needed at synchrotrons, serial data collection is termed serial millisecond crystallography (SMX). As a result, the number of SMX experiments is growing rapidly, with a dozen experiments reported so far. Here, the first high-viscosity injector-based SMX experiments carried out at a US synchrotron source, the Advanced Photon Source (APS), are reported. Microcrystals (5–20 µm) of a wide variety of proteins, including lysozyme, thaumatin, phycocyanin, the human A2A adenosine receptor (A2AAR), the soluble fragment of the membrane lipoprotein Flpp3 and proteinase K, were screened. Crystals suspended in lipidic cubic phase (LCP) or a high-molecular-weight poly(ethylene oxide) (PEO; molecular weight 8 000 000) were delivered to the beam using a high-viscosity injector. In-house data-reduction (hit-finding) software developed at APS as well as the SFX data-reduction and analysis software suites Cheetah and CrystFEL enabled efficient on-site SMX data monitoring, reduction and processing. Complete data sets were collected for A2AAR, phycocyanin, Flpp3, proteinase K and lysozyme, and the structures of A2AAR, phycocyanin, proteinase K and lysozyme were determined at 3.2, 3.1, 2.65 and 2.05 Å resolution, respectively. The data demonstrate the feasibility of serial millisecond crystallography from 5–20 µm crystals using a high-viscosity injector at APS. The resolution of the crystal structures obtained in this study was dictated by the current flux density and crystal size, but upcoming developments in beamline optics and the planned APS-U upgrade will increase the intensity by two orders of magnitude. These developments will enable structure determination from smaller and/or weakly diffracting microcrystals. PMID:28875031
Martin-Garcia, Jose M; Conrad, Chelsie E; Nelson, Garrett; Stander, Natasha; Zatsepin, Nadia A; Zook, James; Zhu, Lan; Geiger, James; Chun, Eugene; Kissick, David; Hilgart, Mark C; Ogata, Craig; Ishchenko, Andrii; Nagaratnam, Nirupa; Roy-Chowdhury, Shatabdi; Coe, Jesse; Subramanian, Ganesh; Schaffer, Alexander; James, Daniel; Ketwala, Gihan; Venugopalan, Nagarajan; Xu, Shenglan; Corcoran, Stephen; Ferguson, Dale; Weierstall, Uwe; Spence, John C H; Cherezov, Vadim; Fromme, Petra; Fischetti, Robert F; Liu, Wei
2017-07-01
Crystal structure determination of biological macromolecules using the novel technique of serial femtosecond crystallography (SFX) is severely limited by the scarcity of X-ray free-electron laser (XFEL) sources. However, recent and future upgrades render microfocus beamlines at synchrotron-radiation sources suitable for room-temperature serial crystallography data collection also. Owing to the longer exposure times that are needed at synchrotrons, serial data collection is termed serial millisecond crystallography (SMX). As a result, the number of SMX experiments is growing rapidly, with a dozen experiments reported so far. Here, the first high-viscosity injector-based SMX experiments carried out at a US synchrotron source, the Advanced Photon Source (APS), are reported. Microcrystals (5-20 µm) of a wide variety of proteins, including lysozyme, thaumatin, phycocyanin, the human A 2A adenosine receptor (A 2A AR), the soluble fragment of the membrane lipoprotein Flpp3 and proteinase K, were screened. Crystals suspended in lipidic cubic phase (LCP) or a high-molecular-weight poly(ethylene oxide) (PEO; molecular weight 8 000 000) were delivered to the beam using a high-viscosity injector. In-house data-reduction (hit-finding) software developed at APS as well as the SFX data-reduction and analysis software suites Cheetah and CrystFEL enabled efficient on-site SMX data monitoring, reduction and processing. Complete data sets were collected for A 2A AR, phycocyanin, Flpp3, proteinase K and lysozyme, and the structures of A 2A AR, phycocyanin, proteinase K and lysozyme were determined at 3.2, 3.1, 2.65 and 2.05 Å resolution, respectively. The data demonstrate the feasibility of serial millisecond crystallography from 5-20 µm crystals using a high-viscosity injector at APS. The resolution of the crystal structures obtained in this study was dictated by the current flux density and crystal size, but upcoming developments in beamline optics and the planned APS-U upgrade will increase the intensity by two orders of magnitude. These developments will enable structure determination from smaller and/or weakly diffracting microcrystals.
Martin-Garcia, Jose M.; Conrad, Chelsie E.; Nelson, Garrett; ...
2017-05-24
Crystal structure determination of biological macromolecules using the novel technique of serial femtosecond crystallography (SFX) is severely limited by the scarcity of X-ray free-electron laser (XFEL) sources. However, recent and future upgrades render microfocus beamlines at synchrotron-radiation sources suitable for room-temperature serial crystallography data collection also. Owing to the longer exposure times that are needed at synchrotrons, serial data collection is termed serial millisecond crystallography (SMX). As a result, the number of SMX experiments is growing rapidly, with a dozen experiments reported so far. Here, the first high-viscosity injector-based SMX experiments carried out at a US synchrotron source, the Advancedmore » Photon Source (APS), are reported. Microcrystals (5–20 µm) of a wide variety of proteins, including lysozyme, thaumatin, phycocyanin, the human A 2A adenosine receptor (A 2AAR), the soluble fragment of the membrane lipoprotein Flpp3 and proteinase K, were screened. Crystals suspended in lipidic cubic phase (LCP) or a high-molecular-weight poly(ethylene oxide) (PEO; molecular weight 8 000 000) were delivered to the beam using a high-viscosity injector. In-house data-reduction (hit-finding) software developed at APS as well as the SFX data-reduction and analysis software suites Cheetah and CrystFEL enabled efficient on-site SMX data monitoring, reduction and processing. Complete data sets were collected for A 2AAR, phycocyanin, Flpp3, proteinase K and lysozyme, and the structures of A 2AAR, phycocyanin, proteinase K and lysozyme were determined at 3.2, 3.1, 2.65 and 2.05 Å resolution, respectively. The data demonstrate the feasibility of serial millisecond crystallography from 5–20 µm crystals using a high-viscosity injector at APS. The resolution of the crystal structures obtained in this study was dictated by the current flux density and crystal size, but upcoming developments in beamline optics and the planned APS-U upgrade will increase the intensity by two orders of magnitude. Furthermore, these developments will enable structure determination from smaller and/or weakly diffracting microcrystals.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Martin-Garcia, Jose M.; Conrad, Chelsie E.; Nelson, Garrett
Crystal structure determination of biological macromolecules using the novel technique of serial femtosecond crystallography (SFX) is severely limited by the scarcity of X-ray free-electron laser (XFEL) sources. However, recent and future upgrades render microfocus beamlines at synchrotron-radiation sources suitable for room-temperature serial crystallography data collection also. Owing to the longer exposure times that are needed at synchrotrons, serial data collection is termed serial millisecond crystallography (SMX). As a result, the number of SMX experiments is growing rapidly, with a dozen experiments reported so far. Here, the first high-viscosity injector-based SMX experiments carried out at a US synchrotron source, the Advancedmore » Photon Source (APS), are reported. Microcrystals (5–20 µm) of a wide variety of proteins, including lysozyme, thaumatin, phycocyanin, the human A 2A adenosine receptor (A 2AAR), the soluble fragment of the membrane lipoprotein Flpp3 and proteinase K, were screened. Crystals suspended in lipidic cubic phase (LCP) or a high-molecular-weight poly(ethylene oxide) (PEO; molecular weight 8 000 000) were delivered to the beam using a high-viscosity injector. In-house data-reduction (hit-finding) software developed at APS as well as the SFX data-reduction and analysis software suites Cheetah and CrystFEL enabled efficient on-site SMX data monitoring, reduction and processing. Complete data sets were collected for A 2AAR, phycocyanin, Flpp3, proteinase K and lysozyme, and the structures of A 2AAR, phycocyanin, proteinase K and lysozyme were determined at 3.2, 3.1, 2.65 and 2.05 Å resolution, respectively. The data demonstrate the feasibility of serial millisecond crystallography from 5–20 µm crystals using a high-viscosity injector at APS. The resolution of the crystal structures obtained in this study was dictated by the current flux density and crystal size, but upcoming developments in beamline optics and the planned APS-U upgrade will increase the intensity by two orders of magnitude. Furthermore, these developments will enable structure determination from smaller and/or weakly diffracting microcrystals.« less
A Human Thrifty Phenotype Associated With Less Weight Loss During Caloric Restriction
Thearle, Marie S.; Ibrahim, Mostafa; Hohenadel, Maximilian G.; Bogardus, Clifton; Krakoff, Jonathan; Votruba, Susanne B.
2015-01-01
Successful weight loss is variable for reasons not fully elucidated. Whether effective weight loss results from smaller reductions in energy expenditure during caloric restriction is not known. We analyzed whether obese individuals with a “thrifty” phenotype, that is, greater reductions in 24-h energy expenditure during fasting and smaller increases with overfeeding, lose less weight during caloric restriction than those with a “spendthrift” phenotype. During a weight-maintaining period, 24-h energy expenditure responses to fasting and 200% overfeeding were measured in a whole-room indirect calorimeter. Volunteers then underwent 6 weeks of 50% caloric restriction. We calculated the daily energy deficit (kilocalories per day) during caloric restriction, incorporating energy intake and waste, energy expenditure, and daily activity. We found that a smaller reduction in 24-h energy expenditure during fasting and a larger response to overfeeding predicted more weight loss over 6 weeks, even after accounting for age, sex, race, and baseline weight, as well as a greater rate of energy deficit accumulation. The success of dietary weight loss efforts is influenced by the energy expenditure response to caloric restriction. Greater decreases in energy expenditure during caloric restriction predict less weight loss, indicating the presence of thrifty and spendthrift phenotypes in obese humans. PMID:25964395
Weight reduction diets and health promotion.
Lissner, L; Steen, S N; Brownell, K D
1992-01-01
Obesity is an important health problem. Despite record rates of dieting and the availability of numerous programs, the problem is not abating. This article discusses the popularity of fad diets, the safety and effectiveness of commonly used approaches to weight loss, and the health effects of weight change. We propose an approach in which the search for a best treatment is secondary to the development of criteria to match patients to different treatments. This approach provides an opportunity for the health professional to take advantage of the multiple weight reduction resources in the community.
NASA Astrophysics Data System (ADS)
Wałach, Daniel; Sagan, Joanna; Gicala, Magdalena
2017-10-01
The paper presents an environmental and economic analysis of the material solutions of multi-level garage. The construction project approach considered reinforced concrete structure under conditions of use of ordinary concrete and high-performance concrete (HPC). Using of HPC allowed to significant reduction of reinforcement steel, mainly in compression elements (columns) in the construction of the object. The analysis includes elements of the methodology of integrated lice cycle design (ILCD). By making multi-criteria analysis based on established weight of the economic and environmental parameters, three solutions have been evaluated and compared within phase of material production (information modules A1-A3).
Near Term Weight Reduction Potential in a 1977 General Motors B Body Vehicle : final report
DOT National Transportation Integrated Search
1978-05-01
The report presents an analysis of the potential for weight reduction through lightweight material and component substitutions in a 1977 General Motors Corporation B body vehicle. The changes were limited to those that appeared producible in the 1980...
Shirai, Kohji; Saiki, Atsuhito; Oikawa, Shinichi; Teramoto, Tamio; Yamada, Nobuhiro; Ishibashi, Shun; Tada, Norio; Miyazaki, Shigeru; Inoue, Ikuo; Murano, Shunichi; Sakane, Naoki; Satoh-Asahara, Noriko; Bujo, Hideaki; Miyashita, Yoh; Saito, Yasushi
2013-01-01
To clarify the usefulness of protein-sparing modified formula diet in obese type 2 diabetic patients, the effects of partial use of formula diet on weight reduction and changes in related metabolic variables, and the improving rates of risk factors per 1% body weight reduction, were compared with those of conventional subcaloric diet. Obese patients [BMI >25 kg/m²] with diabetic mellitus were randomly assigned to a low-caloric diet with partial use of formula diet group (FD, n = 119) and a conventional low-caloric diet group (CD, n = 110). Subjects in FD took one pack of formula diet (MicroDiet®, 240 kcal/pack) in place of one of three daily low-caloric meals for 24 weeks. Total daily calorie prescribed was same. Weight reduction was greater in FD than in CD (week 24: -3.5 vs -1.4 kg; all p < 0.001). Systolic blood pressure decreased significantly only in FD. HbA1c reduction was greater in FD than in CD. HDL-cholesterol increased significantly more in FD than in CD (week 24: +2.8 vs. +0.6 mg/dl, p < 0.001). Among several improving rates (%) of risk factors/1% body weight reduction, those of HbA1c at weeks 16 and 24, triglyceride at week 8 and HDL-cholesterol at week 24, were significantly higher in FD than CD. Doses of sulfonylurea and thiazolidinedione were significantly decreased in FD than in CD. Partial use of formula diet was much more effective in reducing body weight, and also in improving coronary risk factors than conventional diet in part due to reduced body weight through decreased energy diet intake and due to dietary composition of the formula diet. © 2013 Asian Oceanian Association for the Study of Obesity . Published by Elsevier Ltd. All rights reserved.
Weight reduction for non-alcoholic fatty liver disease.
Peng, Lijun; Wang, Jiyao; Li, Feng
2011-06-15
Non-alcoholic fatty liver disease (NAFLD) is becoming a wide spread liver disease. The present recommendations for treatment are not evidence-based. Some of them are various weight reduction measures with diet, exercise, drug, or surgical therapy. To assess the benefits and harms of intended weight reduction for patients with NAFLD. We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, The Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, PubMed, EMBASE, Science Citation Index Expanded, Chinese Biomedicine Database, and ClinicalTrials.gov until February 2011. We included randomised clinical trials evaluating weight reduction with different measures versus no intervention or placebo in NAFLD patients. We extracted data independently. We calculated the odds ratio (OR) for dichotomous data and calculated the mean difference (MD) for continuous data, both with 95% confidence intervals (CI). The review includes seven trials; five on aspects of lifestyle changes (eg, diet, physical exercise) and two on treatment with a weight reduction drug 'orlistat'. In total, 373 participants were enrolled, and the duration of the trials ranged from 1 month to 1 year. Only one trial on lifestyle programme was judged to be of low risk of bias. We could not perform meta-analyses for the main outcomes as they were either not reported or there were insufficient number of trials for each outcome to be meta-analysed. We could meta-analyse the available data for body weight and body mass index only. Adverse events were poorly reported. The sparse data and high risk of bias preclude us from drawing any definite conclusion on lifestyle programme or orlistat for treatment of NAFLD. Further randomised clinical trials with low risk of bias are needed to test the beneficial and harmful effects of weight reduction for NAFLD patients. The long-term prognosis of development of fibrosis, mortality, and quality of life should be studied.
Melchart, Dieter; Löw, Peter; Wühr, Erich; Kehl, Victoria; Weidenhammer, Wolfgang
2017-01-01
Overweight and obesity are globally increasing risk factors for diseases in the context of metabolic syndrome. A randomized controlled trial was conducted to investigate whether there are any existing differences between two lifestyle intervention strategies with respect to weight reduction after 1 year. A total of 166 subjects with a body mass index of 28-35 kg/m 2 were enrolled in this trial at seven study centers; 109 were randomly allocated to the intervention group (comprehensive lifestyle modification program: web-based Individual Health Management [IHM]) with 3-month reduction phase plus 9-month maintenance phase, and 57 were allocated to the control group (written information with advice for healthy food habits: usual care [UC]). Body weight, waist circumference, blood pressure, laboratory findings, and bioimpedance analysis used to determine body composition were measured at baseline and after 3, 6, 9, and 12 months. The primary outcome parameter was body weight at month 12 compared to baseline. With respect to baseline status there were no statistically significant differences between the groups. Based on the intent-to-treat population, body weight showed a mean decrease of 8.7 kg (SD 6.1) in the intervention group (IHM) and 4.2 kg (SD 5) in the control group (UC) at month 12. This statistically significant difference ( P <0.001) was confirmed by various sensitivity analyses. Body mass index, waist circumference, high-density lipid cholesterol, body fat, and the ratio of fat and body cell mass improved to a significantly higher degree in the IHM group. IHM proved to be superior to UC in weight reduction after 1 year. With a mean loss of about 10% of the baseline weight, a clinically high relevant risk reduction for cardio-metabolic diseases is achievable.
Weight reduction intervention for obese infertile women prior to IVF: a randomized controlled trial.
Einarsson, Snorri; Bergh, Christina; Friberg, Britt; Pinborg, Anja; Klajnbard, Anna; Karlström, Per-Olof; Kluge, Linda; Larsson, Ingrid; Loft, Anne; Mikkelsen-Englund, Anne-Lis; Stenlöf, Kaj; Wistrand, Anna; Thurin-Kjellberg, Ann
2017-08-01
Does an intensive weight reduction programme prior to IVF increase live birth rates for infertile obese women? An intensive weight reduction programme resulted in a large weight loss but did not substantially affect live birth rates in obese women scheduled for IVF. Among obese women, fertility and obstetric outcomes are influenced negatively with increased risk of miscarriage and a higher risk of maternal and neonatal complications. A recent large randomized controlled trial found no effect of lifestyle intervention on live birth in infertile obese women. A prospective, multicentre, randomized controlled trial was performed between 2010 and 2016 in the Nordic countries. In total, 962 women were assessed for eligibility and 317 women were randomized. Computerized randomization with concealed allocation was performed in the proportions 1:1 to one of two groups: weight reduction intervention followed by IVF-treatment or IVF-treatment only. One cycle per patient was included. Nine infertility clinics in Sweden, Denmark and Iceland participated. Women under 38 years of age planning IVF, and having a BMI ≥30 and <35 kg/m2 were randomized to two groups: an intervention group (160 patients) with weight reduction before IVF, starting with 12 weeks of a low calorie liquid formula diet (LCD) of 880 kcal/day and thereafter weight stabilization for 2-5 weeks, or a control group (157 patients) with IVF only. In the full analysis set (FAS), the live birth rate was 29.6% (45/152) in the weight reduction and IVF group and 27.5% (42/153) in the IVF only group. The difference was not statistically significant (difference 2.2%, 95% CI: 12.9 to -8.6, P = 0.77). The mean weight change was -9.44 (6.57) kg in the weight reduction and IVF group as compared to +1.19 (1.95) kg in the IVF only group, being highly significant (P < 0.0001). Significantly more live births were achieved through spontaneous pregnancies in the weight reduction and IVF group, 10.5% (16) as compared to the IVF only group 2.6% (4) (P = 0.009). Miscarriage rates and gonadotropin dose used for IVF stimulation did not differ between groups. Two subgroup analyses were performed. The first compared women with PCOS in the two randomized groups, and the second compared women in the weight reduction group reaching BMI ≤ 25 kg/m2 or reaching a weight loss of at least five BMI units to the IVF only group. No statistical differences in live birth rates between the groups in either subgroup analysis were found. The study was not powered to detect a small increase in live births due to weight reduction and was not blinded for the patients or physician. Further, the intervention group had a longer time to achieve a spontaneous pregnancy, but were therefore slightly older than the control group at IVF. The study only included women with a BMI lower than 35 kg/m2. The study suggests that weight loss for obese women (BMI: 30-34.9 kg/m2) may not rectify the outcome in IVF cycles, although a significant higher number of spontaneous conceptions occurred in the weight loss group. Also, the study suggests that intensive weight reduction with LCD treatment does not negatively affects the results. The study was funded by Sahlgrenska University Hospital (ALFGBG-70 940), Merck AB, Solna, Sweden (an affiliate of Merck KGaA, Darmstadt, Germany), Impolin AB, Hjalmar Svensson Foundation and Jane and Dan Olsson Foundation. Dr Thurin-Kjellberg reports grants from Merck, non-financial support from Impolin AB, during the conduct of the study, and personal fees from Merck outside the submitted work. Dr Friberg reports personal fees from Ferring, Merck, MSD, Finox and personal fees from Studentlitteratur, outside the submitted work. Dr Englund reports personal fees from Ferring, and non-financial support from Merck, outside the submitted work. Dr Bergh reports and has been reimbursed for: writing a newsletter twice a year (Ferring), lectures (Ferring, MSD, Merck), and Nordic working group meetings (Finox). Dr Karlström reports lectures (Ferring, Finox, Merck, MSD) and Nordic working group meetings (Ferring). Ms Kluge, Dr Einarsson, Dr Pinborg, Dr Klajnbard, Dr Stenlöf, Dr Larsson, Dr Loft and Dr Wistrand have nothing to disclose. ClinicalTrials.gov number, NCT01566929. 23-03-2012. 05-10-2010. © The Author 2017. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com
Bidzińska, Ewa; Michalec, Marek; Pawcenis, Dominika
2015-12-01
Effect of heating of the potato starch on damages of its structure was investigated by quantitative electron paramagnetic resonance (EPR) spectroscopy, X-ray diffraction and determination of the molecular weight distribution. The measurements were performed in the temperature range commonly used for starch modifications optimizing properties important for industrial applications. Upon thermal treatment, because of breaking of the polymer chains, diminishing of the average molecular weights occurred, which significantly influences generation of radicals, evidenced by EPR. For the relatively mild conditions, with heating parameters not exceeding temperature 230 °C and time of heating equal to 30 min a moderate changes of both the number of thermally generated radicals and the mean molecular weight of the starch were observed. After more drastic thermal treatment (e.g. 2 h at 230 °C), a rapid increase in the radical amount occurred, which was accompanied by significant reduction of the starch molecular size and crystallinity. Experimentally established threshold values of heating parameters should not be exceeded in order to avoid excessive damages of the starch structure accompanied by the formation of the redundant amount of radicals. This requirement is important for industrial applications, because significant destruction of the starch matrix might annihilate the positive influence of the previously performed intentional starch modification. Copyright © 2015 John Wiley & Sons, Ltd.
Correlation between plant physiology and CO2 removable
NASA Astrophysics Data System (ADS)
Leman, A. M.; Shamsuri, Mohd Mahathir Suhaimi; Hariri, Azian; Kadir, Aeslina Abdul; Idris, Ahmad Fu'ad; Afandi, Azizi
2017-09-01
Certain plants that are able to live in the building are known as indoor plants. Plants have tolerance with indoor environment in order to survive. Usually these plants are able to improve indoor air quality (IAQ). Absorption of carbon dioxide (CO2) by plants is one of the indicators that plants are still alive during photosynthesis process. The possibility of plants structure (plant physiology) to affect CO2 absorption had been the concerns of former researchers. This research intends to study the significant of plant structure (leaf area, fresh weight, and dry weight) that leads to reducing the concentration of CO2 by seven plant species (Anthurium, Dumb Cane, Golden Pothos, Kadaka Fern, Prayer Plants, Spider Plants, and Syngonium). The data of CO2 reduction by plants has been obtained from previous studies. Based on results show that, the leaf area is the most contributing the significant effect to the plant absorb CO2 compare to fresh weight and dry weight. It can be prove by Pearson Correlation, where only the value of leaf area is more than 0.5 for every four conditions. This study can be conclude that the leaf area is quite plays an important role to the plant treat air from CO2, while concentration of light and CO2 will become catalytic factor for the plants improve their photosynthesis process.
Saunders, Jeffrey A.
2014-01-01
Direction of self-motion during walking is indicated by multiple cues, including optic flow, nonvisual sensory cues, and motor prediction. I measured the reliability of perceived heading from visual and nonvisual cues during walking, and whether cues are weighted in an optimal manner. I used a heading alignment task to measure perceived heading during walking. Observers walked toward a target in a virtual environment with and without global optic flow. The target was simulated to be infinitely far away, so that it did not provide direct feedback about direction of self-motion. Variability in heading direction was low even without optic flow, with average RMS error of 2.4°. Global optic flow reduced variability to 1.9°–2.1°, depending on the structure of the environment. The small amount of variance reduction was consistent with optimal use of visual information. The relative contribution of visual and nonvisual information was also measured using cue conflict conditions. Optic flow specified a conflicting heading direction (±5°), and bias in walking direction was used to infer relative weighting. Visual feedback influenced heading direction by 16%–34% depending on scene structure, with more effect with dense motion parallax. The weighting of visual feedback was close to the predictions of an optimal integration model given the observed variability measures. PMID:24648194
NASA Technical Reports Server (NTRS)
Dean, Edwin B.; Unal, Resit
1991-01-01
Designing for cost is a state of mind. Of course, a lot of technical knowledge is required and the use of appropriate tools will improve the process. Unfortunately, the extensive use of weight based cost estimating relationships has generated a perception in the aerospace community that the primary way to reduce cost is to reduce weight. Wrong! Based upon an approximation of an industry accepted formula, the PRICE H (tm) production-production equation, Dean demonstrated theoretically that the optimal trajectory for cost reduction is predominantly in the direction of system complexity reduction, not system weight reduction. Thus the phrase "keep it simple" is a primary state of mind required for reducing cost throughout the design process.
Noise control prediction for high-speed, propeller-driven aircraft
NASA Technical Reports Server (NTRS)
Wilby, J. F.; Rennison, D. C.; Wilby, E. G.; Marsh, A. H.
1980-01-01
An analytical study is described which explores add-on treatments and advanced concepts for the reduction of noise levels in three high-speed aircraft driven by propellers. Noise reductions of 25 to 28 dB are required to achieve a goal of an A-weighted sound level not greater than 80 dB. It is found that only a double-wall system, with a limp inner wall or trim panel, can achieve the required noise reductions. Weight penalties are estimated for the double-wall treatments. These penalties are 0.75% to 1.51% of the aircraft takeoff weight for the particular baseline designs selected.
Effect of Weight Loss, Diet, Exercise, and Bariatric Surgery on Nonalcoholic Fatty Liver Disease.
Hannah, William N; Harrison, Stephen A
2016-05-01
Nonalcoholic fatty liver disease (NAFLD) is the hepatic manifestation of the metabolic syndrome. NAFLD is the most common liver disease in developed countries. Weight reduction of 3% to 5% is associated with improved steatosis; reductions of 5% to 7% are necessary for decreased inflammation; with 7% to 10%, individuals may experience NAFLD/NASH remission and regression of fibrosis. No specific dietary intervention has proven beneficial beyond calorie restriction. Physical activity without weight loss seems to decrease hepatic steatosis. Bariatric surgery is associated with decreased cardiovascular risk and improved overall mortality in addition to reduction in hepatic steatosis, inflammation, and fibrosis. Published by Elsevier Inc.
Composite material application for liquid rocket engines
NASA Technical Reports Server (NTRS)
Heubner, S. W.
1982-01-01
With increasing emphasis on improving engine thrust-to-weight ratios to provide improved payload capabilities, weight reductions achievable by the use of composites have become attractive. Of primary significance is the weight reduction offered by composites, although high temperature properties and cost reduction were also considered. The potential for application of composites to components of Earth-to-orbit hydrocarbon engines and orbit-to-orbit LOX/H2 engines was assessed. The components most likely to benefit from the application of composites were identified, as were the critical technology areas where developed would be required. Recommendations were made and a program outlined for the design, fabrication, and demonstration of specific engine components.
Fritz, Jan; Ahlawat, Shivani; Demehri, Shadpour; Thawait, Gaurav K; Raithel, Esther; Gilson, Wesley D; Nittka, Mathias
2016-10-01
The aim of this study was to prospectively test the hypothesis that a compressed sensing-based slice encoding for metal artifact correction (SEMAC) turbo spin echo (TSE) pulse sequence prototype facilitates high-resolution metal artifact reduction magnetic resonance imaging (MRI) of cobalt-chromium knee arthroplasty implants within acquisition times of less than 5 minutes, thereby yielding better image quality than high-bandwidth (BW) TSE of similar length and similar image quality than lengthier SEMAC standard of reference pulse sequences. This prospective study was approved by our institutional review board. Twenty asymptomatic subjects (12 men, 8 women; mean age, 56 years; age range, 44-82 years) with total knee arthroplasty implants underwent MRI of the knee using a commercially available, clinical 1.5 T MRI system. Two compressed sensing-accelerated SEMAC prototype pulse sequences with 8-fold undersampling and acquisition times of approximately 5 minutes each were compared with commercially available high-BW and SEMAC pulse sequences with acquisition times of approximately 5 minutes and 11 minutes, respectively. For each pulse sequence type, sagittal intermediate-weighted (TR, 3750-4120 milliseconds; TE, 26-28 milliseconds; voxel size, 0.5 × 0.5 × 3 mm) and short tau inversion recovery (TR, 4010 milliseconds; TE, 5.2-7.5 milliseconds; voxel size, 0.8 × 0.8 × 4 mm) were acquired. Outcome variables included image quality, display of the bone-implant interfaces and pertinent knee structures, artifact size, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR). Statistical analysis included Friedman, repeated measures analysis of variances, and Cohen weighted k tests. Bonferroni-corrected P values of 0.005 and less were considered statistically significant. Image quality, bone-implant interfaces, anatomic structures, artifact size, SNR, and CNR parameters were statistically similar between the compressed sensing-accelerated SEMAC prototype and SEMAC commercial pulse sequences. There was mild blur on images of both SEMAC sequences when compared with high-BW images (P < 0.001), which however did not impair the assessment of knee structures. Metal artifact reduction and visibility of central knee structures and bone-implant interfaces were good to very good and significantly better on both types of SEMAC than on high-BW images (P < 0.004). All 3 pulse sequences showed peripheral structures similarly well. The implant artifact size was 46% to 51% larger on high-BW images when compared with both types of SEMAC images (P < 0.0001). Signal-to-noise ratios and CNRs of fat tissue, tendon tissue, muscle tissue, and fluid were statistically similar on intermediate-weighted MR images of all 3 pulse sequence types. On short tau inversion recovery images, the SNRs of tendon tissue and the CNRs of fat and fluid, fluid and muscle, as well as fluid and tendon were significantly higher on SEMAC and compressed sensing SEMAC images (P < 0.005, respectively). We accept the hypothesis that prospective compressed sensing acceleration of SEMAC is feasible for high-quality metal artifact reduction MRI of cobalt-chromium knee arthroplasty implants in less than 5 minutes and yields better quality than high-BW TSE and similarly high quality than lengthier SEMAC pulse sequences.
Lacroix, Emilie; Alberga, Angela; Russell-Mathew, Shelly; McLaren, Lindsay; von Ranson, Kristin
2017-01-01
People living with overweight and obesity often experience weight-based stigmatization. Investigations of the prevalence and correlates of weight bias and evaluation of weight bias reduction interventions depend upon psychometrically-sound measurement. Our paper is the first to comprehensively evaluate the psychometric properties, use of people-first language within items, and suitability for use with various populations of available self-report measures of weight bias. We searched five electronic databases to identify English-language self-report questionnaires of weight bias. We rated each questionnaire's psychometric properties based on initial validation reports and subsequent use, and examined item language. Our systematic review identified 40 original self-report questionnaires. Most questionnaires were brief, demonstrated adequate internal consistency, and tapped key cognitive and affective dimensions of weight bias such as stereotypes and blaming. Current psychometric evidence is incomplete for many questionnaires, particularly with regard to the properties of test-retest reliability, sensitivity to change as well as discriminant and structural validity. Most questionnaires were developed prior to debate surrounding terminology preferences, and do not employ people-first language in the items administered to participants. We provide information and recommendations for clinicians and researchers in selecting psychometrically sound measures of weight bias for various purposes and populations, and discuss future directions to improve measurement of this construct. © 2017 The Author(s) Published by S. Karger GmbH, Freiburg.
ODF Maxima Extraction in Spherical Harmonic Representation via Analytical Search Space Reduction
Aganj, Iman; Lenglet, Christophe; Sapiro, Guillermo
2015-01-01
By revealing complex fiber structure through the orientation distribution function (ODF), q-ball imaging has recently become a popular reconstruction technique in diffusion-weighted MRI. In this paper, we propose an analytical dimension reduction approach to ODF maxima extraction. We show that by expressing the ODF, or any antipodally symmetric spherical function, in the common fourth order real and symmetric spherical harmonic basis, the maxima of the two-dimensional ODF lie on an analytically derived one-dimensional space, from which we can detect the ODF maxima. This method reduces the computational complexity of the maxima detection, without compromising the accuracy. We demonstrate the performance of our technique on both artificial and human brain data. PMID:20879302
Changes of dietary patterns during participation in a web-based weight-reduction programme.
Luger, Eva; Aspalter, Rosa; Luger, Maria; Longin, Rita; Rieder, Anita; Dorner, Thomas Ernst
2016-05-01
To examine the weight-loss success associated with distinct dietary patterns and to determine changes of these dietary patterns during participation in a web-based weight-reduction programme. Factor analysis was used to identify the dietary patterns of twenty-two food groups that were administered in 14 d dietary protocols at baseline and after 3 months. Successful weight loss (≥5% of initial weight) and BMI were calculated. Logistic regression analyses were used to assess the rates of weight-loss success from each dietary pattern and changing or remaining in the initial dietary pattern. A generalised linear mixed model was used to estimate the effects of changing or staying in a dietary pattern on change in BMI. Adults (n 1635) aged 18-81 years. Users of a web-based weight-reduction programme (2006-2012). Participants who aligned to a healthful dietary pattern at baseline (OR=1·8; 95% CI 1·5, 2·3) and after 3 months (OR=1·5; 95% CI 1·2, 1·9) had a greater chance of successfully losing weight. After adjusting for age, sex, initial dietary pattern and BMI, participants who started with or changed to the healthful dietary pattern had a greater chance of being successful (OR=1·4; 95% CI 1·1, 1·7) and a higher BMI reduction of 0·30 (95% CI 0·2, 0·5) kg/m(2) compared with those who started with or changed to the energy-dense or high-carbohydrate dietary pattern. A favourable healthful dietary pattern at the beginning and after 3 months was positively associated with anthropometry. However, successful weight loss was feasible in each dietary pattern.
NASA Technical Reports Server (NTRS)
Wade, C. E.; Moran, M. M.; Stein, T. P.; Sin, Sidney (Technical Monitor)
2001-01-01
With the increase in obesity related diseases there is heightened interest in mechanisms regulating body weight. To assess the influence of increases in body weight on energy expenditure and intake in rats we employed variable levels of gravity. Our approach afforded the means to measure interactions of energy expenditure and intake in response to increases in body weight (body mass x gravity level). We found a dose relationship between rapid elevation of body weight and reduction of voluntary movement, such that the energy requirements for activity are unchanged, and total energy expenditure and intake maintained. Reduction of movement appears to be a response to increased body weight, rather than a contributing factor, suggesting a new regulatory pathway.
Leptin Is Required for Glucose Homeostasis after Roux-en-Y Gastric Bypass in Mice.
Mokadem, Mohamad; Zechner, Juliet F; Uchida, Aki; Aguirre, Vincent
2015-01-01
Leptin, the protein product of the ob gene, increases energy expenditure and reduces food intake, thereby promoting weight reduction. Leptin also regulates glucose homeostasis and hepatic insulin sensitivity via hypothalamic proopiomelanocortin neurons in mice. Roux-en-Y gastric bypass (RYGB) induces weight loss that is substantial and sustained despite reducing plasma leptin levels. In addition, patients who fail to undergo diabetes remission after RYGB are hypoletinemic compared to those who do and to lean controls. We have previously demonstrated that the beneficial effects of RYGB in mice require the melanocortin-4 receptor, a downstream effector of leptin action. Based on these observations, we hypothesized that leptin is required for sustained weight reduction and improved glucose homeostasis observed after RYGB. To investigate this hypothesis, we performed RYGB or sham operations on leptin-deficient ob/ob mice maintained on regular chow. To investigate whether leptin is involved in post-RYGB weight maintenance, we challenged post-surgical mice with high fat diet. RYGB reduced total body weight, fat and lean mass and caused reduction in calorie intake in ob/ob mice. However, it failed to improve glucose tolerance, glucose-stimulated plasma insulin, insulin tolerance, and fasting plasma insulin. High fat diet eliminated the reduction in calorie intake observed after RYGB in ob/ob mice and promoted weight regain, although not to the same extent as in sham-operated mice. We conclude that leptin is required for the effects of RYGB on glucose homeostasis but not body weight or composition in mice. Our data also suggest that leptin may play a role in post-RYGB weight maintenance.
Sound Power Minimization of Circular Plates Through Damping Layer Placement
NASA Astrophysics Data System (ADS)
Wodtke, H.-W.; Lamancusa, J. S.
1998-09-01
Damping layers, widely used for noise and vibration control of thin-walled structures, can be designed to provide an optimal trade-off between performance and weight which is of particular importance in the automotive and aircraft industry. The goal of the presented work is the minimization of sound power radiated from plates under broadband excitation by redistribution of unconstrained damping layers. The total radiated sound power is assumed to be represented by the sound power radiated at the structural resonances. Resonance tracking is performed by means of single-degree-of-freedom (SDOF)-approximations based on near-resonance responses and their frequency derivatives. Axisymmetric vibrations of circular plates under several boundary and forcing conditions are considered. Frequency dependent Young's modulus and loss factor of the damping material are taken into account. Vibration analysis is based on the finite element method (FEM) while acoustic radiation is treated by means of Rayleigh's integral formula. It is shown that, starting from a uniform damping layer distribution, substantial reduction in radiated sound power can be achieved through redistribution of the damping layers. Depending on the given situation, these reductions are not only due to amplitude reductions but also to changes in vibration shapes and frequencies.
Batra, Payal; Das, Sai Krupa; Salinardi, Taylor; Robinson, Lisa; Saltzman, Edward; Scott, Tammy; Pittas, Anastassios G; Roberts, Susan B
2013-10-01
We examined the association of food cravings with weight loss and eating behaviors in a lifestyle intervention for weight loss in worksites. This research was part of a randomized controlled trial of a 6-month weight loss intervention versus a wait-listed control in 4 Massachusetts worksites. The intervention emphasized reducing energy intake by adherence to portion-controlled menu suggestions, and assessments were obtained in 95 participants at baseline and 6 months including non-fasting body weight, food cravings (Craving Inventory and Food Craving Questionnaire for state and trait) and the eating behavior constructs restraint, disinhibition and hunger (Eating Inventory). There were statistically significant reductions in all craving variables in the intervention group compared to the controls. Within the intervention group, changes in craving-trait were significantly associated with weight loss after controlling for baseline weight, age, gender and worksite. However, in a multivariate model with craving-trait and eating behaviors (restraint, disinhibition and hunger), hunger was the only significant predictor of weight change. In contrast to some previous reports of increased food cravings with weight loss in lifestyle interventions, this study observed a broad reduction in cravings associated with weight loss. In addition, greater reductions in craving-trait were associated with greater weight change, but craving-trait was not a significant independent correlate of weight change when hunger was included in statistical models. Studies are needed to examine the effectiveness of hunger suppressing versus craving-suppressing strategies in lifestyle interventions for obesity. Copyright © 2013 Elsevier Ltd. All rights reserved.
Castañeda-González, L M; Bacardí Gascón, M; Jiménez Cruz, A
2011-01-01
Low carbohydrate diets (LCD) have shown beneficial effects on short-term weight reduction programs for obese individuals without diabetes, but the long-term evidence of efficacy on individuals with type 2 diabetes is not conclusive. To evaluate, the effectiveness of 12 or more weeks of LCD compared to Low Fat Diet (LFD), Usual Care Diet (UCD) or Low Glycemic Index Diet (LGID) on weight reduction and AIC on type 2 diabetes individuals. A systematic review was conducted on randomized trials registered in PubMed, Cochrane and EBSCOhost from January 1st 2000 to January 1st 2010 including those with an intervention program with LCD in type 2 diabetes subjects and a follow-up ≥ 12 weeks. Available data on study design; carbohydrate composition of diet; duration of diet; and the outcomes of weight, lipid levels (total, low density lipoprotein and high-density lipoprotein cholesterol, and triglycerides), hemoglobin A1C percent and/or fasting glucose were extracted. Five studies showed greater weight reduction with LCD, of which four demonstrated no significant difference. The longest trial intervention studies did not show a difference in weight change. Only two studies showed greater reduction of A1C with LCD, including the longest intervention trial with a low carbohydrate Mediterranean diet. This review shows that there are no consistent differences in weight and A1C changes over the long-term treatment with LCD and LFD, UCD or LGID.
Shantha, Ghanshyam Palamaner Subash; Kumar, Anita Ashok; Ravi, Vimal; Khanna, Rohit C; Kahan, Scott; Cheskin, Lawrence J
2016-06-01
We assessed the predictive accuracy of an empirically-derived score (weight loss, insulin resistance, and glycemic control: "WIG") to predict patients who will be successful in reducing diabetes mellitus (DM) medication use with weight loss. Case records of 121 overweight and obese patients with DM at two outpatient weight management centers were analyzed. Mean period of follow-up was 12.5 ± 3.5 months. To derive the "WIG" scoring algorithm, one point each was assigned to "W" (loss of 5% of initial body weight within the first 3 months of attempting weight loss), "I" (triglyceride [TGL]/highdensity lipoprotein ratio >3 [marker of insulin resistance] at baseline), and "G" (glycosylated hemoglobin [A1c%] >8.5 at baseline). WIG score showed moderate accuracy in discriminating anti-DM dose reductions at baseline, and after 3 months of weight loss efforts (likelihood ratios [LR] + >1, LR- <1, and area under the curve >0.7), and demonstrated good reproducibility. WIG score shows promise as a tool to predict success with dose reductions of antidiabetes medications. Copyright © 2016 Chang Gung University. Published by Elsevier B.V. All rights reserved.
The Use of the STAGS Finite Element Code in Stitched Structures Development
NASA Technical Reports Server (NTRS)
Jegley, Dawn C.; Lovejoy, Andrew E.
2014-01-01
In the last 30 years NASA has worked in collaboration with industry to develop enabling technologies needed to make aircraft more fuel-efficient and more affordable. The focus on the airframe has been to reduce weight, improve damage tolerance and better understand structural behavior under realistic flight and ground loading conditions. Stitched structure is a technology that can address the weight savings, cost reduction, and damage tolerance goals, but only if it is supported by accurate analytical techniques. Development of stitched technology began in the 1990's as a partnership between NASA and Boeing (McDonnell Douglas at the time) under the Advanced Composites Technology Program and has continued under various titles and programs and into the Environmentally Responsible Aviation Project today. These programs contained development efforts involving manufacturing development, design, detailed analysis, and testing. Each phase of development, from coupons to large aircraft components was supported by detailed analysis to prove that the behavior of these structures was well-understood and predictable. The Structural Analysis of General Shells (STAGS) computer code was a critical tool used in the development of many stitched structures. As a key developer of STAGS, Charles Rankin's contribution to the programs was quite significant. Key features of STAGS used in these analyses and discussed in this paper include its accurate nonlinear and post-buckling capabilities, its ability to predict damage growth, and the use of Lagrange constraints and follower forces.
Irreducible Uncertainty in Terrestrial Carbon Projections
NASA Astrophysics Data System (ADS)
Lovenduski, N. S.; Bonan, G. B.
2016-12-01
We quantify and isolate the sources of uncertainty in projections of carbon accumulation by the ocean and terrestrial biosphere over 2006-2100 using output from Earth System Models participating in the 5th Coupled Model Intercomparison Project. We consider three independent sources of uncertainty in our analysis of variance: (1) internal variability, driven by random, internal variations in the climate system, (2) emission scenario, driven by uncertainty in future radiative forcing, and (3) model structure, wherein different models produce different projections given the same emission scenario. Whereas uncertainty in projections of ocean carbon accumulation by 2100 is 100 Pg C and driven primarily by emission scenario, uncertainty in projections of terrestrial carbon accumulation by 2100 is 50% larger than that of the ocean, and driven primarily by model structure. This structural uncertainty is correlated with emission scenario: the variance associated with model structure is an order of magnitude larger under a business-as-usual scenario (RCP8.5) than a mitigation scenario (RCP2.6). In an effort to reduce this structural uncertainty, we apply various model weighting schemes to our analysis of variance in terrestrial carbon accumulation projections. The largest reductions in uncertainty are achieved when giving all the weight to a single model; here the uncertainty is of a similar magnitude to the ocean projections. Such an analysis suggests that this structural uncertainty is irreducible given current terrestrial model development efforts.
Fischer, Arielle G; Wolf, Alon
2018-02-01
Excess body weight has become a major worldwide health and social epidemic. Training with body weight unloading, is a common method for gait corrections for various neuromuscular impairments. In the present study we assessed the effects of body weight unloading on knee and ankle kinetics and muscle activation of overweight subjects walking overground under various levels of body weight unloading. Ten overweight subjects (25 ≤ BMI < 29.9 kg/m 2 ) walked overground under a control and three (0%, 15%, 30%) body weight unloading experimental conditions. Gait parameters assessed under these conditions included knee and ankle flexion moments and the Electromygraphic activity of the Tibialis Anterior, Lateral Gastrocnemius and Vastus Lateralis. Increasing body weight unloading levels from 0% to 30% was found to significantly reduce the peak knee flexion and ankle plantarflexion moments. Also observed was a significant reduction in muscle activity of the Tibialis Anterior, Lateral Gastrocnemius and Vastus Lateralis under the three body-weight unloading conditions. Our results demonstrate that a reduction of up to 30% overweight subjects' body weight during gait is conducive to a reduction in the knee and ankle flexion moments and in the balancing net quadriceps moment and ankle flexors moment. The newly devised body weight unloading device is therefore an effective method for reducing joint loads allowing overweight people who require controlled weight bearing scenarios to retrain their gait while engaging in sustained walking exercise. Copyright © 2018 Elsevier Ltd. All rights reserved.
NASA Technical Reports Server (NTRS)
Robuck, Mark; Wilkerson, Joseph; Maciolek, Robert; Vonderwell, Dan
2012-01-01
A multi-year study was conducted under NASA NNA06BC41C Task Order 10 and NASA NNA09DA56C task orders 2, 4, and 5 to identify the most promising propulsion system concepts that enable rotor cruise tip speeds down to 54% of the hover tip speed for a civil tiltrotor aircraft. Combinations of engine RPM reduction and 2-speed drive systems were evaluated. Three levels of engine and the drive system advanced technology were assessed; 2015, 2025 and 2035. Propulsion and drive system configurations that resulted in minimum vehicle gross weight were identified. Design variables included engine speed reduction, drive system speed reduction, technology, and rotor cruise propulsion efficiency. The NASA Large Civil Tiltrotor, LCTR, aircraft served as the base vehicle concept for this study and was resized for over thirty combinations of operating cruise RPM and technology level, quantifying LCTR2 Gross Weight, size, and mission fuel. Additional studies show design sensitivity to other mission ranges and design airspeeds, with corresponding relative estimated operational cost. The lightest vehicle gross weight solution consistently came from rotor cruise tip speeds between 422 fps and 500 fps. Nearly equivalent results were achieved with operating at reduced engine RPM with a single-speed drive system or with a two-speed drive system and 100% engine RPM. Projected performance for a 2025 engine technology provided improved fuel flow over a wide range of operating speeds relative to the 2015 technology, but increased engine weight nullified the improved fuel flow resulting in increased aircraft gross weights. The 2035 engine technology provided further fuel flow reduction and 25% lower engine weight, and the 2035 drive system technology provided a 12% reduction in drive system weight. In combination, the 2035 technologies reduced aircraft takeoff gross weight by 14% relative to the 2015 technologies.
Whigham, L D; Valentine, A R; Johnson, L K; Zhang, Z; Atkinson, R L; Tanumihardjo, S A
2012-10-01
Individuals who focused on calorie counting lost more weight than those who focused on increasing vegetable and fruit (V&F) intake in a weight loss program. We now present serum carotenoid data (biomarkers of V&F intake) from both groups and test whether these biomarkers correlate with changes in weight and body fat. Sixty obese volunteers were randomized to one of the following weight loss programs: 500 kcal per day reduction (Reduction) or a focus on consuming eight vegetables per day and 2-3 fruits per day (HiVeg). Volunteers in the Reduction group were 36.8±10.3 years with a body mass index of 33.5; 83% were white, 17% chose not to report race; 70% were not Hispanic or Latino, 13% were Hispanic or Latino and 17% chose not to report ethnicity. Volunteers in the HiVeg group were 30.4±6.6 years with a body mass index of 33.2: 74% white, 11% Asian, 5% black or African American, 5% multiracial and 5% chose not to report race; 89% were not Hispanic or Latino, 5% were Hispanic or Latino and 5% chose not to report ethnicity. Subjects were taught basic nutrition principles, received breakfast and lunch 5 days per week for 3 months, meals 2 days per week during month 4, then regular phone calls to month 12. Total serum carotenoid concentrations increased from baseline to 3 months and remained elevated at 12 months, but there was no difference between groups. Changes in weight, fat and % fat correlated negatively with serum carotenoid concentrations. Increased serum carotenoids (a biomarker for V&F intake) correlated with improved weight and fat loss indicating that increased V&F consumption is an appropriate strategy for weight loss. However, in light of the fact that the Reduction group lost more weight, the consumption of increased V&F for the purpose of weight loss should happen within the context of reducing total caloric intake.
Documenting helicopter operations from an energy standpoint
NASA Technical Reports Server (NTRS)
Davis, S. J.; Stepniewski, W. Z.
1974-01-01
Results are presented of a study of the relative and absolute energy consumption of helicopters, including limited comparisons with fixed-wing aircraft, and selected surface transportation vehicles. Additional comparisons were made to determine the level of reduction in energy consumption expected from the application of advanced technologies to the helicopter design and sizing process. It was found that improvements in helicopter consumption characteristics can be accomplished through the utilization of advanced technology to reduce drag, structures weight, and powerplant fuel consumption.
Preliminary Design Options for Meteor Burst Communications Systems Buoy Relays
1986-12-01
FIELDS BRAYTON OTTO ELECTROSTATIC FIELDS SUPERCRITICAL Figure 5.1. Structure of current power source technology for ocean applications. 32 L / P 9 t ~A...As in the sulphur dioxide cell, a low weight, high surface area, carbon positive elec- trode acts as a catalyst for the reduction of the cathode...Operating Transmit Power No. (Relay/Service) Type Covert Covert Mode Duty Cycle (watts) 2.1 Trans Ocean Relay Shore/Ship No Yes Remote 20 Msg/hr 0.9
NASA Technical Reports Server (NTRS)
Krainak, Michael; Merritt, Scott
2016-01-01
Integrated photonics generally is the integration of multiple lithographically defined photonic and electronic components and devices (e.g. lasers, detectors, waveguides passive structures, modulators, electronic control and optical interconnects) on a single platform with nanometer-scale feature sizes. The development of photonic integrated circuits permits size, weight, power and cost reductions for spacecraft microprocessors, optical communication, processor buses, advanced data processing, and integrated optic science instrument optical systems, subsystems and components. This is particularly critical for small spacecraft platforms. We will give an overview of some NASA applications for integrated photonics.
Vazin, Roza; McGinty, Emma E.; Dickerson, Faith; Dalcin, Arlene; Goldsholl, Stacy; Enriquez, Meghan Oefinger; Jerome, Gerald J.; Gennusa, Joseph V.; Daumit, Gail L.
2016-01-01
Objective The purpose of this study was to describe perceptions of weight loss strategies, benefits, and barriers among persons with serious mental illness who lost weight in the ACHIEVE behavioral weight loss intervention. Methods Semi-structured interviews with 20 ACHIEVE participants were conducted and analyzed using an inductive coding approach. Results Participants perceived tailored exercise sessions, social support, and dietary strategies taught in ACHIEVE – such as reducing portion sizes and avoiding sugar-sweetened beverages – as useful weight loss strategies. Health benefits, improved physical appearance, self-efficacy, and enhanced ability to perform activities of daily living were commonly cited benefits of intervention participation and weight loss. Some participants reported challenges with giving up snack food and reducing portion sizes, and barriers to exercise related to medical conditions. Conclusions and Implications for Practice There is emerging evidence that behavioral weight loss interventions can lead to clinically meaningful reductions in body weight among persons with serious mental illness. The perspective of persons with serious mental illness regarding strategies for, benefits of, and barriers to weight loss during participation in behavioral weight loss programs provide insight into which elements of multicomponent interventions such as ACHIEVE are most effective. The results of this study suggest that tailored exercise programs, social support, and emphasis on non-clinical benefits of intervention participation, such as improvements in self-efficacy and the ability to participate more actively in family and community activities, are promising facilitators of engagement and success in behavioral weight loss interventions for the population with serious mental illness. PMID:27054900
DOT National Transportation Integrated Search
2012-07-01
This report presents the Cost Benefit Analysis Test Plan for the national evaluation of the Los Angeles County Congestion Reduction Demonstration (LAC CRD) under the United States Department of Transportation (U.S. DOT) Congestion Reduction Demonstra...
DOT National Transportation Integrated Search
2012-04-01
This report presents the Exogenous Factors Test Plan for the national evaluation of the Los Angeles County Congestion Reduction Demonstration (LAC CRD) under the United States Department of Transportation (U.S. DOT) Congestion Reduction Demonstration...
ERIC Educational Resources Information Center
Clarke, H. Harrison, Ed.
1975-01-01
This document analyzes the problems encountered by the obese individual and the effects of regular exercise on weight loss and fat reduction. Part one compares the psychological traits of obese children with age groups of normal weight and discusses the organic disorders and social attitudes which plague the overweight individual. Part two states…
Weight Reduction Potential of Automobiles and Light Trucks, 1979 Summary Source Document
DOT National Transportation Integrated Search
1980-03-01
The purpose of this report is to provide an assessment of the potential for weight reduction for passenger cars and light trucks (including pickup trucks, vans, and utility vehicles of GVWR up to 8500 pounds) in the 1980 to 2000 model year period. Va...
Steiner, S; Vogl, T J; Fischer, P; Steger, W; Neuhaus, P; Keck, H
1995-08-01
The aim of our study was to evaluate a T2-weighted turbo-spinecho sequence in comparison to a T2-weighted spinecho sequence in imaging focal liver lesions. In our study 35 patients with suspected focal liver lesions were examined. Standardised imaging protocol included a conventional T2-weighted SE sequence (TR/TE = 2000/90/45, acquisition time = 10.20) as well as a T2-weighted TSE sequence (TR/TE = 4700/90, acquisition time = 6.33). Calculation of S/N and C/N ratio as a basis of quantitative evaluation was done using standard methods. A diagnostic score was implemented to enable qualitative assessment. In 7% (n = 2) the TSE sequence enabled detection of further liver lesions showing a size of less than 1 cm in diameter. Comparing anatomical details the TSE sequence was superior. S/N and C/N ratio of anatomic and pathologic structures of the TSE sequence were higher compared to results of the SE sequence. Our results indicate that the T2-weighted turbo-spinecho sequence is well appropriate for imaging focal liver lesions, and leads to reduction of imaging time.
Prediction of successful weight reduction after laparoscopic adjustable gastric banding.
Lee, Yi-Chih; Liew, Phui-Ly; Lee, Wei-Jei; Lin, Yang-Chu; Lee, Chia Ko; Huangs, Ming-Te; Wang, Weu; Lin, Steven C H
2009-01-01
Compared with conventional pharmacological therapies, bariatric surgery has been shown to cause greater and- sustained weight loss. It was aimed to evaluate weight loss in obese patients after laparoscopic adjustable gastric banding surgery using information typically available during the initial evaluation studied before bariatric surgery and genes. 74 patients undergoing laparoscopic adjustable gastric banding (LAGB) were enrolled. Artificial Neural Network technology was used to predict weight loss. We studied 74 patients consisting of 22 men and 52 women 2 years after operation. Mean age was 31.7 +/- 9.1 years. 27 (36.5%) patients had successful weight reduction (excess weight loss >50%) while 47 (63.5%) did not. ANN provided predicted factors on gender, insulin, albumin and two genes: re4684846_r, rs660339_r which were associated with success. Artificial neural network is a better modeling technique and the predictive accuracy is higher on the basis of multiple variables related to laboratory tests. Our finding gave demonstrated result that obese patients of successful weight reduction after laparoscopic adjustable gastric banding surgery were women, having little lower insulin and albumin, and carrying GG genotype on rs4684846 and with at least one T allele on rs660339. In these cases, weight loss will give better results.
Phisalprapa, Pochamana; Supakankunti, Siripen; Charatcharoenwitthaya, Phunchai; Apisarnthanarak, Piyaporn; Charoensak, Aphinya; Washirasaksiri, Chaiwat; Srivanichakorn, Weerachai; Chaiyakunapruk, Nathorn
2017-01-01
Abstract Background: Nonalcoholic fatty liver disease (NAFLD) can be diagnosed early by noninvasive ultrasonography; however, the cost-effectiveness of ultrasonography screening with intensive weight reduction program in metabolic syndrome patients is not clear. This study aims to estimate economic and clinical outcomes of ultrasonography in Thailand. Methods: Cost-effectiveness analysis used decision tree and Markov models to estimate lifetime costs and health benefits from societal perspective, based on a cohort of 509 metabolic syndrome patients in Thailand. Data were obtained from published literatures and Thai database. Results were reported as incremental cost-effectiveness ratios (ICERs) in 2014 US dollars (USD) per quality-adjusted life year (QALY) gained with discount rate of 3%. Sensitivity analyses were performed to assess the influence of parameter uncertainty on the results. Results: The ICER of ultrasonography screening of 50-year-old metabolic syndrome patients with intensive weight reduction program was 958 USD/QALY gained when compared with no screening. The probability of being cost-effective was 67% using willingness-to-pay threshold in Thailand (4848 USD/QALY gained). Screening before 45 years was cost saving while screening at 45 to 64 years was cost-effective. Conclusions: For patients with metabolic syndromes, ultrasonography screening for NAFLD with intensive weight reduction program is a cost-effective program in Thailand. Study can be used as part of evidence-informed decision making. Translational Impacts: Findings could contribute to changes of NAFLD diagnosis practice in settings where economic evidence is used as part of decision-making process. Furthermore, study design, model structure, and input parameters could also be used for future research addressing similar questions. PMID:28445256
Minimum weight design of helicopter rotor blades with frequency constraints
NASA Technical Reports Server (NTRS)
Chattopadhyay, Aditi; Walsh, Joanne L.
1989-01-01
The minimum weight design of helicopter rotor blades subject to constraints on fundamental coupled flap-lag natural frequencies has been studied in this paper. A constraint has also been imposed on the minimum value of the blade autorotational inertia to ensure that the blade has sufficient inertia to autorotate in case of an engine failure. The program CAMRAD has been used for the blade modal analysis and the program CONMIN has been used for the optimization. In addition, a linear approximation analysis involving Taylor series expansion has been used to reduce the analysis effort. The procedure contains a sensitivity analysis which consists of analytical derivatives of the objective function and the autorotational inertia constraint and central finite difference derivatives of the frequency constraints. Optimum designs have been obtained for blades in vacuum with both rectangular and tapered box beam structures. Design variables include taper ratio, nonstructural segment weights and box beam dimensions. The paper shows that even when starting with an acceptable baseline design, a significant amount of weight reduction is possible while satisfying all the constraints for blades with rectangular and tapered box beams.
Unsteady Probabilistic Analysis of a Gas Turbine System
NASA Technical Reports Server (NTRS)
Brown, Marilyn
2003-01-01
In this work, we have considered an annular cascade configuration subjected to unsteady inflow conditions. The unsteady response calculation has been implemented into the time marching CFD code, MSUTURBO. The computed steady state results for the pressure distribution demonstrated good agreement with experimental data. We have computed results for the amplitudes of the unsteady pressure over the blade surfaces. With the increase in gas turbine engine structural complexity and performance over the past 50 years, structural engineers have created an array of safety nets to ensure against component failures in turbine engines. In order to reduce what is now considered to be excessive conservatism and yet maintain the same adequate margins of safety, there is a pressing need to explore methods of incorporating probabilistic design procedures into engine development. Probabilistic methods combine and prioritize the statistical distributions of each design variable, generate an interactive distribution and offer the designer a quantified relationship between robustness, endurance and performance. The designer can therefore iterate between weight reduction, life increase, engine size reduction, speed increase etc.
Effects of ionomer morphology on oxygen reduction on Pt
Chlistunoff, Jerzy; Pivovar, Bryan
2015-05-21
In this paper, the oxygen reduction reaction (ORR) at the interface between platinum and Nafion 1100 equivalent weight was studied as a function of temperature (20–80 °C), humidity (10–100%), scan rate, the manner in which Nafion film was deposited, and the state of the Pt surface using ultramicroelectrodes employing cyclic voltammetry and chronoamperometry. ORR on smooth electrodes was strongly inhibited under specific conditions dependent on temperature, humidity, and scan rate. From the data presented, we postulate that dynamic changes in the molecular structure of the ionomer at the platinum interface result in differences in ORR voltammetry for films prepared andmore » equilibrated under different conditions. The lack of similar changes for rough, platinized electrodes has been attributed to differences in initial ionomer structure and a higher energy barrier for ionomer restructuring. Finally, these model system studies yield insight into the ionomer-catalyst interface of particular interest for polymer electrolyte fuel cells.« less
Preliminary noise tradeoff study of a Mach 2.7 cruise aircraft
NASA Technical Reports Server (NTRS)
Mascitti, V. R.; Maglieri, D. J. (Editor); Raney, J. P. (Editor)
1979-01-01
NASA computer codes in the areas of preliminary sizing and enroute performance, takeoff and landing performance, aircraft noise prediction, and economics were used in a preliminary noise tradeoff study for a Mach 2.7 design supersonic cruise concept. Aerodynamic configuration data were based on wind-tunnel model tests and related analyses. Aircraft structural characteristics and weight were based on advanced structural design methodologies, assuming conventional titanium technology. The most advanced noise prediction techniques available were used, and aircraft operating costs were estimated using accepted industry methods. The 4-engines cycles included in the study were based on assumed 1985 technology levels. Propulsion data was provided by aircraft manufacturers. Additional empirical data is needed to define both noise reduction features and other operating characteristics of all engine cycles under study. Data on VCE design parameters, coannular nozzle inverted flow noise reduction and advanced mechanical suppressors are urgently needed to reduce the present uncertainties in studies of this type.
NASA Astrophysics Data System (ADS)
Ries, S.; Spoerrer, A.; Altstaedt, V.
2014-05-01
Polymer foams play an important role caused by the steadily increasing demand to light weight design. In case of soft polymers, like thermoplastic elastomers (TPE), the haptic feeling of the surface is affected by the inner foam structure. Foam injection molding of TPEs leads to so called structural foam, consisting of two compact skin layers and a cellular core. The properties of soft structural foams like soft-touch, elastic and plastic behavior are affected by the resulting foam structure, e.g. thickness of the compact skins and the foam core or density. This inner structure can considerably be influenced by different processing parameters and the chosen blowing agent. This paper is focused on the selection and characterization of suitable blowing agents for foam injection molding of a TPE-blend. The aim was a high density reduction and a decent inner structure. Therefore DSC and TGA measurements were performed on different blowing agents to find out which one is appropriate for the used TPE. Moreover a new analyzing method for the description of processing characteristics by temperature dependent expansion measurements was developed. After choosing suitable blowing agents structural foams were molded with different types of blowing agents and combinations and with the breathing mold technology in order to get lower densities. The foam structure was analyzed to show the influence of the different blowing agents and combinations. Finally compression tests were performed to estimate the influence of the used blowing agent and the density reduction on the compression modulus.
Delaney, Kevin J; Weaver, David K; Peterson, Robert K D
2010-04-01
The impact of herbivory on plants is variable and influenced by several factors. The current study examined causes of variation in the impact of larval stem mining by the wheat stem sawfly, Cephus cinctus Norton (Hymenoptera: Cephidae), on spring wheat, Triticum aestivum L. We performed greenhouse experiments over 2 yr to (1) study whether biotic (hollow versus solid stemmed host wheat) and abiotic (water, phosphorus stress) factors interact with C. cinctus stem mining to influence degree of mined stem physiological (photosynthesis) and yield (grain weight) reductions; and (2) determine whether whole plant yield compensatory responses occur to offset stem-mining reductions. Flag leaf photosynthetic reduction was not detected 16-20 d after infestation, but were detected at 40-42 d and doubled from water or phosphorus stresses. Main stem grain weight decreased from 10 to 25% from stem mining, largely due to reductions in grain size, with greater reductions under low phosphorus and/or water levels. Phosphorus-deficient plants without water stress were most susceptible to C. cinctus, more than doubling the grain weight reduction due to larval feeding relative to other water and phosphorus treatments. Two solid stemmed varieties with stem mining had less grain weight loss than a hollow stemmed variety, so greater internal mechanical resistance may reduce larval stem mining and plant yield reductions. Our results emphasize the importance of sufficient water and macronutrients for plants grown in regions impacted by C. cinctus. Also, solid stemmed varieties not only reduce wheat lodging from C. cinctus, they may reduce harvested grain losses from infested stems.
The impact of reducing car weight on global emissions: the future fleet in Great Britain
Norman, Jonathan B.; Allwood, Julian M.
2017-01-01
Current European policies define targets for future direct emissions of new car sales that foster a fast transition to electric drivetrain technologies. However, these targets do not consider the emissions produced in electricity generation and material production, and therefore fail to incentivise car manufacturers to consider the benefits of vehicle weight reduction. In this paper, we examine the potential benefits of limiting the average weight and altering the material composition of new cars in terms of global greenhouse gas emissions produced during the use phase, electricity generation and material production. We anticipate the emissions savings for the future car fleet in Great Britain until 2050 for various alternative futures, using a dynamic material flow analysis of ferrous metals and aluminium, and considering an evolving demand for car use. The results suggest that fostering vehicle weight reduction could produce greater cumulative emissions savings by 2050 than those obtained by incentivising a fast transition to electric drivetrains, unless there is an extreme decarbonization of the electricity grid. Savings promoted by weight reduction are immediate and do not depend on the pace of decarbonization of the electricity grid. Weight reduction may produce the greatest savings when mild steel in the car body is replaced with high-strength steel. This article is part of the themed issue ‘Material demand reduction’. PMID:28461428
Design and analysis of truck body for increasing the payload capacity
NASA Astrophysics Data System (ADS)
Vamshi Krishna, K.; Yugandhar Reddy, K.; Venugopal, K.; Ravi, K.
2017-11-01
Truck industry is a major source of transportation in India. With an average truck travelling about 300 kilometers per day [1], every kilogram of truck weight is of concern to the industry in order to get the best out of the truck. The main objective of this project is to increase the payload capacity of automotive truck body. Every kilogram of increased vehicle weight will decrease the vehicle payload capacity in turn increasing the manufacturing cost and reducing the fuel economy by increase the fuel consumption. With the intension of weight reduction, standard truck body has been designed and analyzed in ANSYS software. C-cross section beams were used instead of conventional rectangular box sections to reduce the weight of the body. Light-weight Aluminum alloy Al 6061 T6 is used to increase the payload capacity. The strength of the Truck platform is monitored in terms of deformation and stress concentration. These parameters will be obtained in structural analysis test condition environment. For reducing the stress concentration the concept of beams of uniform strength is used. Accordingly necessary modifications are done so that the optimized model has a better stress distribution and much lesser weight compared to the conventional model. The results obtained by analyzing the modified model are compared with the standard model.
Hinchman, Josephine; Beno, Luke; Mims, Adrienne
2006-01-01
Context: The rate of overweight (OW) in children in the United States has more than tripled since 1980. The health consequences of pediatric OW include type 2 diabetes and significant illness later in life. Treating pediatric OW is a necessity; however, health care clinicians have minimal access to successful and comprehensive treatment modalities for addressing it. Objective: Kaiser Permanente of Georgia (KPGA) offers a group medical appointment clinic, Operation Zero (O.Z.), as a referral program for preadolescent and adolescent patients who are in the 85th or higher percentile for body mass index (BMI) for their age. The eight-session clinic uses a family-oriented approach and provides a supportive group environment with interactive learning, games, physical activity, and creative problem solving. The goal of the program is to improve lifestyle behaviors for nutrition and physical activity. Clinically, meeting these goals can manifest as reductions in body fat (BF), waist size, and BMI-for-age percentile. Two implementation models help improve dissemination of the program within KPGA. Design: Baseline and eight-week postclinical outcomes for O.Z. participants were analyzed to determine program effectiveness. A retrospective analysis with a control group looked at long-term clinical outcomes to determine weight maintenance. Main outcome measures were weight, BMI-for-age percentile, waist size, and percentage of body fat (%BF). Results: At eight weeks after program completion compared with baseline, there were significant reductions in %BF and waist size for the total sample and specifically for adolescents, preteens, and participants who attended six or more sessions. Among O.Z. participants, there were insignificant increases in weight at six months after program participation and BMI-for-age percentile at one year after participation. At six months, the mean change in weight and BMI in the O.Z. group was statistically less than the mean change in the control group. Conclusions: A structured, family-oriented weight management program is effective in changing measures consistent with improved weight management. PMID:21519478
Bischoff, S C; Damms-Machado, A; Betz, C; Herpertz, S; Legenbauer, T; Löw, T; Wechsler, J G; Bischoff, G; Austel, A; Ellrott, T
2012-04-01
To determine the effectiveness of a structured multidisciplinary non-surgical obesity therapy program on the basis of a temporary low-calorie-diet for 12 weeks, and additional intervention modules to enhance nutritional education, to increase physical activity and to modify eating behavior. Prospective multicenter observational study in obese individuals undergoing a medically supervised outpatient-based 52-week treatment in 37 centers in Germany. A total of 8296 participants with a body mass index (BMI) of >30 kg m(-2) included within 8.5 years. Main outcome measures were body weight loss, waist circumference (WC), blood pressure, quality of life and adverse events. In females, initial body weight was reduced after the 1-year-intervention by 19.6 kg (95% confidence intervals 19.2-19.9 kg) and in males by 26.0 kg (25.2-26.8) according to per protocol analysis of 4850 individuals. Intention-to-treat (ITT) analysis revealed a weight reduction of 15.2 kg (14.9-15.6) in females and 19.4 kg (18.7-20.1) in males. Overall, the intervention resulted in mean reduction in WC of 11 cm; it reduced the prevalence of the metabolic syndrome by 50% and the frequency of hypertension from 47 to 29% of all participants (ITT, all P<0.001). The beneficial effects could be documented for up to 3 years and comprised significant improvement of health-related quality of life. The incidence of adverse effects was low; the only event repeatedly observed and possibly related to either the intervention or the underlying disease was biliary disorders. The present non-surgical intervention program is a highly effective treatment of obesity grades I-III and obesity-related diseases, and therefore, could be a valuable basis for future weight maintenance strategies required for sustained success.
Bischoff, S C; Damms-Machado, A; Betz, C; Herpertz, S; Legenbauer, T; Löw, T; Wechsler, J G; Bischoff, G; Austel, A; Ellrott, T
2012-01-01
Objectives: To determine the effectiveness of a structured multidisciplinary non-surgical obesity therapy program on the basis of a temporary low-calorie-diet for 12 weeks, and additional intervention modules to enhance nutritional education, to increase physical activity and to modify eating behavior. Design: Prospective multicenter observational study in obese individuals undergoing a medically supervised outpatient-based 52-week treatment in 37 centers in Germany. Subjects: A total of 8296 participants with a body mass index (BMI) of >30 kg m−2 included within 8.5 years. Measurements: Main outcome measures were body weight loss, waist circumference (WC), blood pressure, quality of life and adverse events. Results: In females, initial body weight was reduced after the 1-year-intervention by 19.6 kg (95% confidence intervals 19.2–19.9 kg) and in males by 26.0 kg (25.2–26.8) according to per protocol analysis of 4850 individuals. Intention-to-treat (ITT) analysis revealed a weight reduction of 15.2 kg (14.9–15.6) in females and 19.4 kg (18.7–20.1) in males. Overall, the intervention resulted in mean reduction in WC of 11 cm; it reduced the prevalence of the metabolic syndrome by 50% and the frequency of hypertension from 47 to 29% of all participants (ITT, all P<0.001). The beneficial effects could be documented for up to 3 years and comprised significant improvement of health-related quality of life. The incidence of adverse effects was low; the only event repeatedly observed and possibly related to either the intervention or the underlying disease was biliary disorders. Conclusion: The present non-surgical intervention program is a highly effective treatment of obesity grades I–III and obesity-related diseases, and therefore, could be a valuable basis for future weight maintenance strategies required for sustained success. PMID:21673653
DOE Office of Scientific and Technical Information (OSTI.GOV)
Tom, Nathan M.; Yu, Yi -Hsiang; Wright, Alan D.
The aim of this study is to describe a procedure to maximize the power-to-load ratio of a novel wave energy converter (WEC) that combines an oscillating surge wave energy converter with variable structural components. The control of the power-take-off torque will be on a wave-to-wave timescale, whereas the structure will be controlled statically such that the geometry remains the same throughout the wave period. Linear hydrodynamic theory is used to calculate the upper and lower bounds for the time-averaged absorbed power and surge foundation loads while assuming that the WEC motion remains sinusoidal. Previous work using pseudo-spectral techniques to solvemore » the optimal control problem focused solely on maximizing absorbed energy. This work extends the optimal control problem to include a measure of the surge foundation force in the optimization. The objective function includes two competing terms that force the optimizer to maximize power capture while minimizing structural loads. A penalty weight was included with the surge foundation force that allows control of the optimizer performance based on whether emphasis should be placed on power absorption or load shedding. Results from pseudo-spectral optimal control indicate that a unit reduction in time-averaged power can be accompanied by a greater reduction in surge-foundation force.« less
Tom, Nathan M.; Yu, Yi -Hsiang; Wright, Alan D.; ...
2017-04-18
The aim of this study is to describe a procedure to maximize the power-to-load ratio of a novel wave energy converter (WEC) that combines an oscillating surge wave energy converter with variable structural components. The control of the power-take-off torque will be on a wave-to-wave timescale, whereas the structure will be controlled statically such that the geometry remains the same throughout the wave period. Linear hydrodynamic theory is used to calculate the upper and lower bounds for the time-averaged absorbed power and surge foundation loads while assuming that the WEC motion remains sinusoidal. Previous work using pseudo-spectral techniques to solvemore » the optimal control problem focused solely on maximizing absorbed energy. This work extends the optimal control problem to include a measure of the surge foundation force in the optimization. The objective function includes two competing terms that force the optimizer to maximize power capture while minimizing structural loads. A penalty weight was included with the surge foundation force that allows control of the optimizer performance based on whether emphasis should be placed on power absorption or load shedding. Results from pseudo-spectral optimal control indicate that a unit reduction in time-averaged power can be accompanied by a greater reduction in surge-foundation force.« less
Control Oriented Modeling and Validation of Aeroservoelastic Systems
NASA Technical Reports Server (NTRS)
Crowder, Marianne; deCallafon, Raymond (Principal Investigator)
2002-01-01
Lightweight aircraft design emphasizes the reduction of structural weight to maximize aircraft efficiency and agility at the cost of increasing the likelihood of structural dynamic instabilities. To ensure flight safety, extensive flight testing and active structural servo control strategies are required to explore and expand the boundary of the flight envelope. Aeroservoelastic (ASE) models can provide online flight monitoring of dynamic instabilities to reduce flight time testing and increase flight safety. The success of ASE models is determined by the ability to take into account varying flight conditions and the possibility to perform flight monitoring under the presence of active structural servo control strategies. In this continued study, these aspects are addressed by developing specific methodologies and algorithms for control relevant robust identification and model validation of aeroservoelastic structures. The closed-loop model robust identification and model validation are based on a fractional model approach where the model uncertainties are characterized in a closed-loop relevant way.
3D Printing Variable Stiffness Foams Using Viscous Thread Instability
Lipton, Jeffrey I.; Lipson, Hod
2016-01-01
Additive manufacturing of cellular structures has numerous applications ranging from fabrication of biological scaffolds and medical implants, to mechanical weight reduction and control over mechanical properties. Various additive manufacturing processes have been used to produce open regular cellular structures limited only by the resolution of the printer. These efforts have focused on printing explicitly designed cells or explicitly planning offsets between strands. Here we describe a technique for producing cellular structures implicitly by inducing viscous thread instability when extruding material. This process allows us to produce complex cellular structures at a scale that is finer than the native resolution of the printer. We demonstrate tunable effective elastic modulus and density that span two orders of magnitude. Fine grained cellular structures allow for fabrication of foams for use in a wide range of fields ranging from bioengineering, to robotics to food printing. PMID:27503148
Legenbauer, Tanja; Petrak, Frank; de Zwaan, Martina; Herpertz, Stephan
2011-01-01
To investigate the influence of depressive and eating disorders on short- and long-term weight loss after surgical and non-surgical weight-reduction treatment. Covariations between the disorders were considered. In a longitudinal naturalistic study, current diagnoses at baseline and lifetime diagnoses of depressive and eating disorders were assessed in participants who were undertaking a very-low-calorie diet (n = 250) and in bariatric surgery patients (n = 153). Lifetime diagnosis of a mental disorder was defined as presence of a mental disorder only in the past. Body weight was measured at baseline, 1 year after baseline, and 4 years after baseline. Mental comorbidity was assessed through use of standardized interviews at baseline. A structural equation modeling procedure was applied to test the associations between course of weight and mental disorders. Analyses were based on the intention to treat samples. Missing values were replaced by use of multiple imputation procedures. Neither depression nor eating disorders were associated with weight changes at the 1-year follow-up, but a specific effect emerged for bariatric surgery patients after 4 years: depression (current and lifetime) predicted smaller body mass index loss, whereas lifetime diagnosis of eating disorder was associated with greater weight loss. Individuals who report depressive disorders prior to bariatric surgery should be monitored more closely in order to identify patients who would benefit from additional therapy with the goal of improving weight-loss outcome. Copyright © 2011 Elsevier Inc. All rights reserved.
Sand, Anne-Sofie; Emaus, Nina; Lian, Olaug S
2017-05-08
Due to a worldwide increase in overweight and obesity, weight-management through lifestyle changes has become an important public health issue. Adolescents and young adults comprise a vulnerable group. The transition into adulthood represents a stage in life when establishing good lifestyle habits for the future is important. The aim of this study was to explore motivation and obstacles for weight reduction, weight maintenance and healthy lifestyle choices in young women. We conducted semi-structured in depth interviews with 12 young women, both overweight and normal weight, recruited from a school-based population survey. By the use of thematic analysis we searched the interview text for relevant meaning units that emerged as topics that illuminated our research questions. A strong motivation for obtaining or keeping normal weight was clearly present among the participants. Independent of weight-group, the participants described increased levels of physical activity, better eating habits and regularity in daily life as desirable changes. Parents were described as important influencers regarding lifestyle habits. Several participants expressed a need for more information about healthy nutrition and eating. Their motivation for physical activity depended on a positive social setting and elements of joy. The participants described the transition into adulthood including moving out of their parents' home and other structural changes in everyday life, as challenging. It affected their food choices and eating habits and other lifestyle issues. High costs of healthy food and sports activities were frequently mentioned among the obstacles they encountered. The results revealed an obvious motivation for lifestyle changes in individuals and environmental challenges for young women in the relevant stage of their life-course. There seems to be a need for health strategies that strengthens individuals' capacity to overcome the environmental challenges in the transition to adulthood. This should include reliable and accessible health education/information regarding healthy nutrition, eating habits, food choices and preparation of meals. Structural initiatives such as easier access to affordable healthy food and less expensive opportunities for physical activity and sports should be considered.
NASA Astrophysics Data System (ADS)
Wang, Sheng; Yang, Weitao; Du, Hongli; Guo, Fangfang; Wang, Hanjie; Chang, Jin; Gong, Xiaoqun; Zhang, Bingbo
2016-04-01
Multifunctional superparamagnetic iron-oxide (SPIO)-based nanoparticles have been emerging as candidate nanosystems for cancer diagnosis and therapy. Here, we report the use of reduction- responsive SPIO/doxorubicin (DOX)-loaded poly(ethylene glycol) monomethyl ether (PEG)ylated polymeric lipid vesicles (SPIO&DOX-PPLVs) as a novel theranostic system for tumor magnetic resonance imaging (MRI) diagnosis and controlled drug delivery. These SPIO&DOX-PPLVs are composed of SPIOs that function as MR contrast agents for tumor enhancement and PPLVs as polymer matrices for encapsulating SPIO and antitumor drugs. The in vitro characterizations show that the SPIO&DOX-PPLVs have nanosized structures (˜80 nm), excellent colloidal stability, good biocompatibility, as well as T 2-weighted MRI capability with a relatively high T 2 relaxivity (r 2 = 213.82 mM-1 s-1). In vitro drug release studies reveal that the release rate of DOX from the SPIO&DOX-PPLVs is accelerated in the reduction environment. An in vitro cellular uptake study and an antitumor study show that the SPIO&DOX-PPLVs have magnetic targeting properties and effective antitumor activity. In vivo studies show the SPIO&DOX-PPLVs have excellent T 2-weighted tumor targeted MRI capability, image-guided drug delivery capability, and high antitumor effects. These results suggest that the SPIO&DOX-PPLVs are promising nanocarriers for MRI diagnosis and cancer therapy applications.
Clark, Larkin; Wells, Martha H; Harris, Edward F; Lou, Jennifer
2016-01-01
To determine if aggressiveness of primary tooth preparation varied among different brands of zirconia and stainless steel (SSC) crowns. One hundred primary typodont teeth were divided into five groups (10 posterior and 10 anterior) and assigned to: Cheng Crowns (CC); EZ Pedo (EZP); Kinder Krowns (KKZ); NuSmile (NSZ); and SSC. Teeth were prepared, and assigned crowns were fitted. Teeth were weighed prior to and after preparation. Weight changes served as a surrogate measure of tooth reduction. Analysis of variance showed a significant difference in tooth reduction among brand/type for both the anterior and posterior. Tukey's honest significant difference test (HSD), when applied to anterior data, revealed that SSCs required significantly less tooth removal compared to the composite of the four zirconia brands, which showed no significant difference among them. Tukey's HSD test, applied to posterior data, revealed that CC required significantly greater removal of crown structure, while EZP, KKZ, and NSZ were statistically equivalent, and SSCs required significantly less removal. Zirconia crowns required more tooth reduction than stainless steel crowns for primary anterior and posterior teeth. Tooth reduction for anterior zirconia crowns was equivalent among brands. For posterior teeth, reduction for three brands (EZ Pedo, Kinder Krowns, NuSmile) did not differ, while Cheng Crowns required more reduction.
An exploration of the experiences and perceptions of people who have maintained weight loss.
Hindle, L; Carpenter, C
2011-08-01
In clinical weight-loss trials, the majority of those who lose weight will regain almost all of it within 5 years, yet there is limited evidence about effective strategies to support weight maintenance. The present study aimed to increase understanding of the experiences of those who have been successful at weight maintenance. This qualitative study used a phenomenological approach. Semi-structured interviews were undertaken with a purposive sample of 10 participants who had maintained a minimum of 10% weight loss for at least 1 year. Interviews were transcribed and then analysed using a foundational thematic approach based on the Colaizzi method. Participants believed that a more relaxed approach to weight management with realistic, long-term goals was more appropriate for long-term control. They had a strong reason to lose weight often with a medical trigger and had elicited support to help them. Most described the presence of saboteurs. Participants took personal responsibility for their weight management and were in tune with their nutrition and activity needs. Self-monitoring was a strategy commonly used to support this. They described the lack of positive reinforcement in the maintenance phase as a major difficulty. This small-scale study provides evidence to suggest the importance of a medical prompt to lose weight; planning for how to manage saboteurs and identifying methods of minimising the impact of a reduction in positive reinforcement. It reinforces the importance of many of the strategies known to support the weight-loss phase. © 2011 The Authors. Journal of Human Nutrition and Dietetics © 2011 The British Dietetic Association Ltd.
Cradock, Kevin A; ÓLaighin, Gearóid; Finucane, Francis M; Gainforth, Heather L; Quinlan, Leo R; Ginis, Kathleen A Martin
2017-02-08
Changing diet and physical activity behaviour is one of the cornerstones of type 2 diabetes treatment, but changing behaviour is challenging. The objective of this study was to identify behaviour change techniques (BCTs) and intervention features of dietary and physical activity interventions for patients with type 2 diabetes that are associated with changes in HbA 1c and body weight. We performed a systematic review of papers published between 1975-2015 describing randomised controlled trials (RCTs) that focused exclusively on both diet and physical activity. The constituent BCTs, intervention features and methodological rigour of these interventions were evaluated. Changes in HbA 1c and body weight were meta-analysed and examined in relation to use of BCTs. Thirteen RCTs were identified. Meta-analyses revealed reductions in HbA 1c at 3, 6, 12 and 24 months of -1.11 % (12 mmol/mol), -0.67 % (7 mmol/mol), -0.28 % (3 mmol/mol) and -0.26 % (2 mmol/mol) with an overall reduction of -0.53 % (6 mmol/mol [95 % CI -0.74 to -0.32, P < 0.00001]) in intervention groups compared to control groups. Meta-analyses also showed a reduction in body weight of -2.7 kg, -3.64 kg, -3.77 kg and -3.18 kg at 3, 6, 12 and 24 months, overall reduction was -3.73 kg (95 % CI -6.09 to -1.37 kg, P = 0.002). Four of 46 BCTs identified were associated with >0.3 % reduction in HbA 1c : 'instruction on how to perform a behaviour', 'behavioural practice/rehearsal', 'demonstration of the behaviour' and 'action planning', as were intervention features 'supervised physical activity', 'group sessions', 'contact with an exercise physiologist', 'contact with an exercise physiologist and a dietitian', 'baseline HbA 1c >8 %' and interventions of greater frequency and intensity. Diet and physical activity interventions achieved clinically significant reductions in HbA 1c at three and six months, but not at 12 and 24 months. Specific BCTs and intervention features identified may inform more effective structured lifestyle intervention treatment strategies for type 2 diabetes.
Effect on the lipid parameters of an intervention to reduce weight in overweight and obese patients.
Tárraga Marcos, M Loreto; Panisello Royo, Josefa María; Carbayo Herencia, Julio A; Rosich Domenech, Nuria; Alins Presas, Josep; Tárraga López, Pedro J
To assess the effect on lipid parameters most associated with excess weight (triglycerides [TG], cholesterol, and high density lipoprotein [HDL-C]) of an intervention to reduce weight in overweight and obese patients. A randomised, controlled, double blind clinical trial, with three groups, and a follow-up of 12 months. Patients included in the study were randomised into three intervention groups: Obesity motivational intervention group with previously trained nurse (G1), lower intensity consultation, non-motivational group, with digital platform support (G2), and a third group that received a recommendation to lose weight and usual follow-up (G3). The anthropometric variables measured were height, weight, and abdominal/waist circumference, and laboratory results, total cholesterol, TG and HDL cholesterol). The study include 176 patients, of whom 60 were randomised to G1, 61 to G2, and 59 to G3. All groups significantly decreased body weight at the end of the study, with a decrease in G1 (-5.6kg), followed by G2 (-4.3kg), and G3 (-1.7kg), with an overall mean loss of -3.9kg. There was a also significant decrease (P<.05) in total cholesterol and TG, and an increased HDL-C. These changes were more marked in the G1 group (the group that lost more weight). The clinical relevance indicators that were significant were: in the case of TG: G1/G3: relative risk: 1.42 (95% CI: 1.11-1.80); relative risk reduction: 41.7% (11.4-80.2); absolute risk reduction: 25% (9.2-40.8) and NNT: 5 (3-11). In the case of G1/G2 HDL-C: relative risk: 1.32 (1.07-1.63); relative risk reduction: 32.2% (7.4-62.6); absolute risk reduction: 21.1% (6.4-35.8) and NNT: 5 (3-16). Weight reduction is accompanied by favorable changes in the lipid parameters related to overweight and obesity, being more intense the greater the weight loss. Copyright © 2017 Sociedad Española de Arteriosclerosis. Publicado por Elsevier España, S.L.U. All rights reserved.
Additive-manufactured sandwich lattice structures: A numerical and experimental investigation
NASA Astrophysics Data System (ADS)
Fergani, Omar; Tronvoll, Sigmund; Brøtan, Vegard; Welo, Torgeir; Sørby, Knut
2017-10-01
The utilization of additive-manufactured lattice structures in engineered products is becoming more and more common as the competitiveness of AM as a production technology has increased during the past several years. Lattice structures may enable important weight reductions as well as open opportunities to build products with customized functional properties, thanks to the flexibility of AM for producing complex geometrical configurations. One of the most critical aspects related to taking AM into new application areas—such as safety critical products—is currently the limited understanding of the mechanical behavior of sandwich-based lattice structure mechanical under static and dynamic loading. In this study, we evaluate manufacturability of lattice structures and the impact of AM processing parameters on the structural behavior of this type of sandwich structures. For this purpose, we conducted static compression testing for a variety of geometry and manufacturing parameters. Further, the study discusses a numerical model capable of predicting the behavior of different lattice structure. A reasonably good correlation between the experimental and numerical results was observed.
NASA Astrophysics Data System (ADS)
Hameer, Sameer
Rotorcraft transmission design is limited by empirical weight trends that are proportional to the power/torque raised to the two-thirds coupled with the relative inexperience industry has with the employment of variable speed transmission to heavy lift helicopters of the order of 100,000 lbs gross weight and 30,000 installed horsepower. The advanced rotorcraft transmission program objectives are to reduce transmission weight by at least 25%, reduce sound pressure levels by at least 10 dB, have a 5000 hr mean time between removal, and also incorporate the use of split torque technology in rotorcraft drivetrains of the future. The major obstacle that challenges rotorcraft drivetrain design is the selection, design, and optimization of a variable speed transmission in the goal of achieving a 50% reduction in rotor speed and its ability to handle high torque with light weight gears, as opposed to using a two-speed transmission which has inherent structural problems and is highly unreliable due to the embodiment of the traction type transmission, complex clutch and brake system. This thesis selects a nontraction pericyclic continuously variable transmission (P-CVT) as the best approach for a single main rotor heavy lift helicopter. The objective is to target and overcome the above mentioned obstacle for drivetrain design. Overcoming this obstacle provides advancement in the state of the art of drivetrain design over existing planetary and split torque transmissions currently used in helicopters. The goal of the optimization process was to decrease weight, decrease noise, increase efficiency, and increase safety and reliability. The objective function utilized the minimization of the weight and the major constraint is the tooth bending stress of the facegears. The most important parameters of the optimization process are weight, maintainability, and reliability which are cross-functionally related to each other, and these parameters are related to the torques and operating speeds. The analysis of the split torque type P-CVT achieved a weight reduction of 42.5% and 40.7% over planetary and split torque transmissions respectively. In addition, a 19.5 dB sound pressure level reduction was achieved using active gear struts, and also the use of fabricated steel truss like housing provided a higher maintainability and reliability, low cost, and low weight over cast magnesium housing currently employed in helicopters. The static finite element analysis of the split torque type P-CVT, both 2-D and 3-D, yielded stresses below the allowable bending stress of the material. The goal of the finite element analysis is to see if the designed product has met its functional requirements. The safety assessment of the split torque type P-CVT yielded a 99% probability of mission success based on a Monte Carlo simulation using stochastic-petri net analysis and a failure hazard analysis. This was followed by an FTA/RBD analysis which yielded an overall system failure rate of 140.35 failures per million hours, and a preliminary certification and time line of certification was performed. The use of spherical facegears and pericyclic kinematics has advanced the state of the art in drivetrain design primarily in the reduction of weight and noise coupled with high safety, reliability, and efficiency.
Weight Reduction Diets. New Horizons in Nutrition.
ERIC Educational Resources Information Center
Arnold, Justine; Grogan, Jane, Ed.
This instructional handbook is one of a series of ten packets designed to form a comprehensive course in nutrition for secondary students. The focus of this booklet is on weight reduction diets and, in particular, those diets emphasizing reduced intake of carbohydrates. It contains a page of teaching suggestions, a pre-test for the students, and…
Diet, inflammation and prediabetes-impact of quality of diet.
Uusitupa, Matti; Schwab, Ursula
2013-10-01
Low grade inflammation has been linked to risk of type 2 diabetes and atherosclerotic vascular diseases. Obesity and, in particular, abdominal obesity increase the risk of diabetes and atherosclerotic vascular diseases. One of the mechanisms could be low grade inflammation and vascular endothelial dysfunction. Permanent weight reduction is the first line of treatment both for obese individuals at increased risk of diabetes and for newly onset type 2 diabetes. Weight reduction lowers the level of several inflammatory factors in the body while increasing the level of adiponectin. Besides weight reduction the quality of diet and physical activity also modifies low grade inflammation. Based on the literature survey and our own studies in humans, it is possible to have dietary patterns that reduce inflammatory stress in the body and improves vascular endothelial dysfunction. There is strong evidence to suggest that IL-1 Ra is a very sensitive marker of low grade inflammation in obesity and related phenotypes; however, its level is markedly lowered by weight reduction and by choosing foods that have been shown to reduce inflammatory stress in the body. Copyright © 2013. Published by Elsevier Inc.
Vegetarian Diets and Weight Reduction: a Meta-Analysis of Randomized Controlled Trials.
Huang, Ru-Yi; Huang, Chuan-Chin; Hu, Frank B; Chavarro, Jorge E
2016-01-01
Vegetarian diets may promote weight loss, but evidence remains inconclusive. PubMed, EMBASE and UpToDate databases were searched through September 22, 2014, and investigators extracted data regarding study characteristics and assessed study quality among selected randomized clinical trials. Population size, demographic (i.e., gender and age) and anthropometric (i.e., body mass index) characteristics, types of interventions, follow-up periods, and trial quality (Jadad score) were recorded. The net changes in body weight of subjects were analyzed and pooled after assessing heterogeneity with a random effects model. Subgroup analysis was performed based on type of vegetarian diet, type of energy restriction, study population, and follow-up period. Twelve randomized controlled trials were included, involving a total of 1151 subjects who received the intervention over a median duration of 18 weeks. Overall, individuals assigned to the vegetarian diet groups lost significantly more weight than those assigned to the non-vegetarian diet groups (weighted mean difference, -2.02 kg; 95 % confidence interval [CI]: -2.80 to -1.23). Subgroup analysis detected significant weight reduction in subjects consuming a vegan diet (-2.52 kg; 95 % CI: -3.02 to -1.98) and, to a lesser extent, in those given lacto-ovo-vegetarian diets (-1.48 kg; 95 % CI: -3.43 to 0.47). Studies on subjects consuming vegetarian diets with energy restriction (ER) revealed a significantly greater weight reduction (-2.21 kg; 95 % CI: -3.31 to -1.12) than those without ER (-1.66 kg; 95 % CI: -2.85 to -0.48). The weight loss for subjects with follow-up of <1 year was greater (-2.05 kg; 95 % CI: -2.85 to -1.25) than those with follow-up of ≥1 year (-1.13 kg; 95 % CI: -2.04 to -0.21). Vegetarian diets appeared to have significant benefits on weight reduction compared to non-vegetarian diets. Further long-term trials are needed to investigate the effects of vegetarian diets on body weight control.
Gravante, Gianpiero; Araco, Antonino; Araco, Francesco; Delogu, Daniela; De Lorenzo, Antonino; Cervelli, Valerio
2007-10-01
To evaluate potential differences between 2 devices used to perform laparoscopic adjustable gastric bandings (the Swedish adjustable gastric band and the Lap-Band). The following groups were considered eligible: (1) patients with a body mass index (calculated as weight in kilograms divided by height in meters squared) of greater than 40; (2) patients with a body mass index between 35 and 40, with associated comorbidities; and (3) patients with a body mass index of greater than 60 who could not undergo derivative procedures. We recruited 400 patients. The mean +/- SD body mass index decreased to 40.6 +/- 3.0 after the first year and to 35.2 +/- 7.0 after 2 years. The average excess weight loss reduction was 48.2% after 1 year and 56.0% after 2 years. The excess weight loss reduction was inversely related to the initial weight: patients with an estimated weight excess of 50 kg or less (108 patients [27.0%]) had an excess weight loss reduction of 55% after 2 years; those with a weight excess of greater than 50 kg (292 patients [73.0%]) had an excess weight loss reduction of 44% (P = .004). We recorded 1 death (0.2%). Transient gastric occlusions (24 patients [6.0%]) and slippages (12 patients [3.0%]) were the most common complications. The devices used (Swedish adjustable gastric band and Lap-Band) were similar in terms of correction of obesity and morbidity. Laparoscopic adjustable gastric banding is a safe and feasible technique with specific indications in moderately obese patients and, secondarily, in highly obese patients who are unfit for more invasive techniques. No differences were found among the devices examined. isrctn.org Identifier: ISRCTN22839090.
Effect of weight reduction on quality of life and eating behaviors in obese women.
Lemoine, Sophie; Rossell, Nadia; Drapeau, Vicky; Poulain, Magali; Garnier, Sophie; Sanguignol, Frédéric; Mauriège, Pascale
2007-01-01
To examine the impact of a 3-week weight-reducing program on body composition, physical condition, health-related quality of life, and eating behaviors of sedentary, obese (body mass index, 29-35 kg/m) women, according to menopausal status and menopause duration (<5, >or=5, and >or=10 y). Thirteen premenopausal and 27 postmenopausal women received a dietary plan of 1,400 +/- 200 kcal/day and completed 110-minute endurance exercise 6 days per week. Body mass index, fat mass, lean mass, distance walked in the Six-Minute Walk Test, health-related quality of life estimated by the 36-item Short Form Health Survey (SF-36), and eating behaviors (restriction, disinhibition, and susceptibility to hunger) assessed by the Three-Factor Eating Questionnaire were determined before and after weight reduction. Body mass index and fat mass decreased (P < 0.0001), whereas distance walked increased in both groups after weight reduction (P < 0.001). Although the SF-36 mental component score increased after weight loss in both groups (P < 0.0001), the SF-36 physical component score increased in postmenopausal women only (P < 0.001). Restriction increased (P < 0.0001), whereas disinhibition and susceptibility to hunger decreased after weight reduction (P < 0.001 and P < 0.01, respectively) in both groups. Distance walked and SF-36 physical component score after weight loss were higher in women whose menopause ranged between 5 and 9 years and exceeded 10 years, respectively (P < 0.01). Our study shows that a short-term weight-reducing program combining caloric restriction and physical activity has a favorable impact on women's body composition, physical condition, health-related quality of life, and eating behaviors irrespective of their menopausal status.
Race Disparities and Decreasing Birth Weight: Are All Babies Getting Smaller?
Catov, Janet M.; Lee, MinJae; Roberts, James M.; Xu, Jia; Simhan, Hyagriv N.
2016-01-01
The mean infant birth weight in the United States increased for decades, but it might now be decreasing. Given race disparities in fetal growth, we explored race-specific trends in birth weight at Magee-Womens Hospital, Pittsburgh, Pennsylvania, from 1997 to 2011. Among singleton births delivered at 37–41 weeks (n = 70,607), we evaluated the proportions who were small for gestational age and large for gestational age and changes in mean birth weights over time. Results were stratified by maternal race/ethnicity. Since 1997, the number of infants born small for their gestational ages increased (8.7%–9.9%), whereas the number born large for their gestational ages decreased (8.9%–7.7%). After adjustment for gestational week at birth, maternal characteristics, and pregnancy conditions, birth weight decreased by 2.20 g per year (P < 0.0001). Decreases were greater for spontaneous births. Reductions were significantly greater in infants born to African-American women than in those born to white women (−3.78 vs. −1.88 per year; P for interaction = 0.010). Quantile regression models indicated that birth weight decreased across the entire distribution, but reductions among infants born to African-American women were limited to those in the upper quartile after accounting for maternal factors. Limiting the analysis to low-risk women eliminated birth weight reductions. Birth weight has decreased in recent years, and reductions were greater in infants born to African-American women. These trends might be explained by accumulation of risk factors such as hypertension and prepregnancy obesity that disproportionately affect African-American women. Our results raise the possibility of worsening race disparities in fetal growth. PMID:26667251
Energy density and rate limitations in structural composite supercapacitors
NASA Astrophysics Data System (ADS)
Snyder, J. F.; Gienger, E.; Wetzel, E. D.; Xu, K.
2012-06-01
The weight and volume of conventional energy storage technologies greatly limits their performance in mobile platforms. Traditional research efforts target improvements in energy density to reduce device size and mass. Enabling a device to perform additional functions, such as bearing mechanical load, is an alternative approach as long as the total mass efficiency exceeds that of the individual materials it replaces. Our research focuses on structural composites that function as batteries and supercapacitors. These multifunctional devices could be used to replace conventional structural components, such as vehicle frame elements, to provide significant system-level weight reductions and extend mission times. Our approach is to design structural properties directly into the electrolyte and electrode materials. Solid polymer electrolyte materials bind the system and transfer load to the fibers while conducting ions between the electrodes. Carbon fiber electrodes provide a route towards optimizing both energy storage and load-bearing capabilities, and may also obviate the need for a separate current collector. The components are being integrated using scalable, cost-effective composite processing techniques that are amenable to complex part shapes. Practical considerations of energy density and rate behavior are described here as they relate to materials used. Our results highlight the viability as well as the challenges of this multifunctional approach towards energy storage.
Composite Development and Applications for RLV Tankage
NASA Technical Reports Server (NTRS)
Wright, Richard J.; Achary, David C.; McBain, Michael C.
2003-01-01
The development of polymer composite cryogenic tanks is a critical step in creating the next generation of launch vehicles. Future launch vehicles need to minimize the gross liftoff weight (GLOW), which is possible due to the 28%-41% reduction in weight that composite materials can provide over current aluminum technology. The development of composite cryogenic tanks, feedlines, and unpressurized structures are key enabling technologies for performance and cost enhancements for Reusable Launch Vehicles (RLVs). The technology development of composite tanks has provided direct and applicable data for feedlines, unpressurized structures, material compatibility, and cryogenic fluid containment for highly loaded complex structures and interfaces. All three types of structure have similar material systems, processing parameters, scaling issues, analysis methodologies, NDE development, damage tolerance, and repair scenarios. Composite cryogenic tankage is the most complex of the 3 areas and provides the largest breakthrough in technology. A building block approach has been employed to bring this family of difficult technologies to maturity. This approach has built up composite materials, processes, design, analysis and test methods technology through a series of composite test programs beginning with the NASP program to meet aggressive performance goals for reusable launch vehicles. In this paper, the development and application of advanced composites for RLV use is described.
Rapid weight loss in the context of Ramadan observance: recommendations for judokas
Chtourou, H; Briki, W; Tabben, M; Chaouachi, A; Souissi, N; Shephard, RJ; Chamari, K
2016-01-01
Judo is a weight-classified combat sport, and many athletes seek to compete at the lightest possible weight category to gain an advantage from competing against shorter/smaller, and supposedly weaker opponents. To achieve a desired weight, most judokas opt for rapid weight loss techniques. Short-duration maximal efforts are not greatly affected by “making weight”, but prolonged and/or repeated exercise is significantly impaired. Negative effects on mood, ratings of perceived exertion, and cognitive function are also reported. Moreover, rapid weight loss reduces maximal cardiac output and glycogen stores, and impairs thermo-regulation. Limited empirical data suggest that Ramadan reduces judokas’ performance, and this is likely to be exacerbated by attempts at rapid weight loss. Weight reduction during Ramadan tends to be counterproductive, and judokas who aim for a lower weight category are advised to attempt any desired reduction of body mass during the weeks leading up to Ramadan, rather than during the holy month. PMID:28090146
Xiang, Y-T; Wang, C-Y; Ungvari, G S; Kreyenbuhl, J A; Chiu, H F K; Lai, K Y C; Lee, E H M; Bo, Q-J; Dixon, L B
2011-06-01
This study aimed to characterize weight changes in schizophrenia patients taking risperidone as part of a randomized, controlled, open-label clinical trial. A total of 374 patients with schizophrenia who had been clinically stabilized following an acute episode were randomly assigned to a 'no-dose-reduction' group (initial optimal therapeutic doses continued throughout the study), a '4-week group' (initial optimal therapeutic doses continued for 4 weeks followed by a half dose reduction that was maintained until the end of the study) or a '26-week group' (initial optimal therapeutic doses continued for 26 weeks followed by a half dose reduction until the end of the study). Participants were assessed monthly using standardized assessment instruments during the first 6 months, and then every 2 months until the last recruited patient completed the 1-year follow-up. Weight gain was defined as gaining at least 7% of initial body weight, weight loss as losing at least 7% of initial body weight. A BMI <18.5 kg m⁻² was defined as underweight, 18.5-24.9 kg m⁻² as normal range, and ≥ 25 kg m⁻² as overweight or obese. At the end of follow-up, of the patients who started within the underweight range (n=22), 77.3% gained weight, whereas 4.5% lost weight. The corresponding figures were 39.6% and 4.8% in patients who started at normal weight (n=273), respectively, and 17.7% and 17.7% in patients who started at overweight (n=79), respectively. At the same time, 59.1% of the patients who started at underweight range went into the normal weight and 13.6% into the overweight/obese range, respectively, while 24.5% of those who started at normal weight went into the overweight/obese range, and 1.1% into underweight range, respectively; 20.3% of those who started at overweight range went into normal weight at the end of the follow-up. Multiple logistic regression analyses revealed that being underweight or normal weight at study entry predicted weight gain compared to being overweight, whereas being overweight at entry was associated with a higher likelihood of weight loss compared to being normal weight. No correlation was found between weight change and dose reduction. Weight change is a common, long-term, but heterogeneous side effect in risperidone maintenance treatment for stable schizophrenia patients. Special attention should be paid to fluctuations in weight that may occur throughout the course of treatment with risperidone. © Georg Thieme Verlag KG Stuttgart · New York.
Cabin noise and weight reduction program for the Gulfstream G200
NASA Astrophysics Data System (ADS)
Barton, C. Kearney
2002-11-01
This paper describes the approach and logic involved in a cabin noise and weight reduction program for an existing aircraft that was already in service with a pre-existing insulation package. The aircraft, a Gulfstream G200, was formally an IAI Galaxy, and the program was purchased from IAI in 2001. The approach was to investigate every aspect of the aircraft that could be a factor for cabin noise. This included such items as engine mounting and balancing criteria, the hydraulic system, the pressurization and air-conditioning system, the outflow valve, the interior shell and mounting system, antennae and other hull protuberances, as well as the insulation package. Each of these items was evaluated as potential candidates for noise and weight control modifications. Although the program is still ongoing, the results to date include a 175-lb weight savings and a 5-dB reduction in the cabin average Speech Interference Level (SIL).
Automated variance reduction for MCNP using deterministic methods.
Sweezy, J; Brown, F; Booth, T; Chiaramonte, J; Preeg, B
2005-01-01
In order to reduce the user's time and the computer time needed to solve deep penetration problems, an automated variance reduction capability has been developed for the MCNP Monte Carlo transport code. This new variance reduction capability developed for MCNP5 employs the PARTISN multigroup discrete ordinates code to generate mesh-based weight windows. The technique of using deterministic methods to generate importance maps has been widely used to increase the efficiency of deep penetration Monte Carlo calculations. The application of this method in MCNP uses the existing mesh-based weight window feature to translate the MCNP geometry into geometry suitable for PARTISN. The adjoint flux, which is calculated with PARTISN, is used to generate mesh-based weight windows for MCNP. Additionally, the MCNP source energy spectrum can be biased based on the adjoint energy spectrum at the source location. This method can also use angle-dependent weight windows.
Gustafsson, Ulf; Benthin, Lisbet; Granström, Lars; Groen, Albert K; Sahlin, Staffan; Einarsson, Curt
2005-06-01
The aim of the present study was to elucidate the mechanisms of development of cholesterol crystals and gallstones during weight reduction in obese subjects. Twenty-five morbidly obese, gallstone-free subjects underwent vertical-banded gastroplasty. Gallbladder bile was collected at the time of the operation via needle aspiration and 1.1-7.3 months after the operation via ultrasound-guided transhepatic puncture of the gallbladder. The mean weight loss was 17 kg. Two patients developed gallstones and 10 patients displayed cholesterol crystals in their bile. In patients with a follow-up time of less than 2 months (n = 13), cholesterol saturation increased from 90% to 114% but tended to decrease in the patients with a follow-up time of more than 2 months. The extraction of the concanavalin-A-binding fraction from gallbladder bile obtained after weight reduction in 7 patients prolonged crystallization detection time from 6 to 10 days. The hexosamine concentration, a marker for mucin, was increased by about 100% in bile obtained in 6 of 7 patients after weight reduction. In conclusion, the results indicate that crystallization-promoting compounds (mucin) are of great importance in the development of cholesterol crystals and gallstones in obese subjects during weight reduction, probably because of defective gallbladder emptying.
Murdolo, Giuseppe; Tortoioli, Cristina; Celi, Federica; Bini, Vittorio; Papi, Francesco; Brozzetti, Annalisa; Falorni, Alberto
2017-05-01
The secreted hepatokine fetuin-A emerges as an independent predictor of type 2 diabetes in adulthood. The overall aims of this study were: (1) to investigate the associations of fetuin-A with adiposity and insulin resistance, as well as its relationship with adipokines, in prepubertal children, and, (2) to evaluate whether, in prepubertal obesity, serum fetuin-A levels may either change or predict the responsiveness to an educational-based weight excess reduction program. We studied 200 prepubertal children (boys/girls: 89/111; Tanner stage 1; age: 5-13 years), included in a cohort of 44,231 adolescents who participated in an extensive Italian school-based survey. According to Cole's criteria, 100 individuals were lean (boys/girls: 57/43) and 100 obese (boys/girls: 54/46). A subset of 53 obese individuals (boys/girls: 28/25; age: 6-12 years) were also evaluated after a weight excess reduction program. Serum fetuin-A, leptin, total and high molecular weight adiponectin levels, as well as homeostasis model assessment of insulin resistance were assessed. When compared with lean, obese children exhibited higher ( p < 0.0001) fetuin-A concentrations, without differences between sex. Fetuin-A was positively associated with adiposity, homeostasis model assessment of insulin resistance, and leptin levels. In multivariate analysis, the associations between fetuin-A and leptin or homeostasis model assessment of insulin resistance lost the significance after adjustment for BMI Z-score , which, in turn, represented an independent determinant of fetuin-A (R 2 adj 0.327; p < 0.0001). Notably, after weight excess reduction program, fetuin-A levels dropped ( p < 0.0001 vs. basal). Interestingly, no significant differences of fetuin-A concentrations between responders and no responders were found. In prepubertal children, fetuin-A represents an early marker of adiposity, and its reduction after lifestyle intervention may partly contribute to the beneficial effects of weight excess reduction program.
Pucci, Andrea; Cheung, Wui Hang; Jones, Jenny; Manning, Sean; Kingett, Helen; Adamo, Marco; Elkalaawy, Mohamed; Jenkinson, Andrew; Finer, Nicholas; Doyle, Jacqueline; Hashemi, Majid; Batterham, Rachel L
2015-01-01
Sleeve gastrectomy (SG) is the second most commonly performed bariatric procedure worldwide. Altered circulating gut hormones have been suggested to contribute post-operatively to appetite suppression, decreased caloric intake and weight reduction. In the present study, we report a 22-year-old woman who underwent laparoscopic SG for obesity (BMI 46 kg/m(2)). Post-operatively, she reported marked appetite reduction, which resulted in excessive weight loss (1-year post-SG: BMI 22 kg/m(2), weight loss 52%, >99th centile of 1-year percentage of weight loss from 453 SG patients). Gastrointestinal (GI) imaging, GI physiology/motility studies and endoscopy revealed no anatomical cause for her symptoms, and psychological assessments excluded an eating disorder. Despite nutritional supplements and anti-emetics, her weight loss continued (BMI 19 kg/m(2)), and she required nasogastric feeding. A random gut hormone assessment revealed high plasma peptide YY (PYY) levels. She underwent a 3 h meal study following an overnight fast to assess her subjective appetite and circulating gut hormone levels. Her fasted nausea scores were high, with low hunger, and these worsened with nutrient ingestion. Compared to ten other post-SG female patients, her fasted circulating PYY and nutrient-stimulated PYY and active glucagon-like peptide 1 (GLP1) levels were markedly elevated. Octreotide treatment was associated with suppressed circulating PYY and GLP1 levels, increased appetite, increased caloric intake and weight gain (BMI 22 kg/m(2) after 6 months). The present case highlights the value of measuring gut hormones in patients following bariatric surgery who present with anorexia and excessive weight loss and suggests that octreotide treatment can produce symptomatic relief and weight regain in this setting. Roux-en-Y gastric bypass and SG produce marked sustained weight reduction. However, there is a marked individual variability in this reduction, and post-operative weight loss follows a normal distribution with extremes of 'good' and 'poor' response.Profound anorexia and excessive weight loss post-SG may be associated with markedly elevated circulating fasted PYY and post-meal PYY and GLP1 levels.Octreotide treatment can produce symptomatic relief and weight regain for post-SG patients that have an extreme anorectic and weight loss response.The present case highlights the value of measuring circulating gut hormone levels in patients with post-operative anorexia and extreme weight loss.
Development of laminar flow control wing surface porous structure
NASA Technical Reports Server (NTRS)
Klotzsche, M.; Pearce, W.; Anderson, C.; Thelander, J.; Boronow, W.; Gallimore, F.; Brown, W.; Matsuo, T.; Christensen, J.; Primavera, G.
1984-01-01
It was concluded that the chordwise air collection method, which actually combines chordwise and spanwise air collection, is the best of the designs conceived up to this time for full chord laminar flow control (LFC). Its shallower ducting improved structural efficiency of the main wing box resulting in a reduction in wing weight, and it provided continuous support of the chordwise panel joints, better matching of suction and clearing airflow requirements, and simplified duct to suction source minifolding. Laminar flow control on both the upper and lower surfaces was previously reduced to LFC suction on the upper surface only, back to 85 percent chord. The study concludes that, in addition to reduced wing area and other practical advantages, this system would be lighter because of the increase in effective structural wing thickness.
The optimal design of UAV wing structure
NASA Astrophysics Data System (ADS)
Długosz, Adam; Klimek, Wiktor
2018-01-01
The paper presents an optimal design of UAV wing, made of composite materials. The aim of the optimization is to improve strength and stiffness together with reduction of the weight of the structure. Three different types of functionals, which depend on stress, stiffness and the total mass are defined. The paper presents an application of the in-house implementation of the evolutionary multi-objective algorithm in optimization of the UAV wing structure. Values of the functionals are calculated on the basis of results obtained from numerical simulations. Numerical FEM model, consisting of different composite materials is created. Adequacy of the numerical model is verified by results obtained from the experiment, performed on a tensile testing machine. Examples of multi-objective optimization by means of Pareto-optimal set of solutions are presented.
Composite containment systems for jet engine fan blades
NASA Technical Reports Server (NTRS)
Smith, G. T.
1981-01-01
The use of composites in fan blade containment systems is investigated and the associated structural benefits of the composite system design are identified. Two basic types of containment structures were investigated. The short finned concept was evaluated using Kevlar/epoxy laminates for fins which were mounted in a 6061 T-6 aluminum ring. The long fin concept was evaluated with Kevlar/epoxy, 6Al4V titanium, and 2024 T-3 aluminum fins. The unfinned configurations consisted of the base-line steel sheet, a circumferentially oriented aluminum honeycomb, and a Kevlar cloth filled ring. Results obtained show that a substantial reduction in the fan blade containment system weight is possible. Minimization of damage within the engine arising from impact interaction between blade debris and the engine structure is also achieved.
Willeboordse, Maartje; van de Kant, Kim D. G.; Tan, Frans E. S.; Mulkens, Sandra; Schellings, Julia; Crijns, Yvonne; van der Ploeg, Liesbeth; van Schayck, Constant P.; Dompeling, Edward
2016-01-01
Background There is increasing evidence that obesity is related to asthma development and severity. However, it is largely unknown whether weight reduction can influence asthma management, especially in children. Objective To determine the effects of a multifactorial weight reduction intervention on asthma management in overweight/obese children with (a high risk of developing) asthma. Methods An 18-month weight-reduction randomized controlled trial was conducted in 87 children with overweight/obesity and asthma. Every six months, measurements of anthropometry, lung function, lifestyle parameters and inflammatory markers were assessed. Analyses were performed with linear mixed models for longitudinal analyses. Results After 18 months, the body mass index-standard deviation score decreased by -0.14±0.29 points (p<0.01) in the intervention group and -0.12±0.34 points (p<0.01) in the control group. This change over time did not differ between groups (p>0.05). Asthma features (including asthma control and asthma-related quality of life) and lung function indices (static and dynamic) improved significantly over time in both groups. The FVC% predicted improved over time by 10.1 ± 8.7% in the intervention group (p<0.001), which was significantly greater than the 6.1 ± 8.4% in the control group (p<0.05). Conclusions & clinical relevance Clinically relevant improvements in body weight, lung function and asthma features were found in both the intervention and control group, although some effects were more pronounced in the intervention group (FVC, asthma control, and quality of life). This implies that a weight reduction intervention could be clinically beneficial for children with asthma. Trial Registration ClinicalTrials.gov NCT00998413 PMID:27294869
Palavras, Marly Amorim; Hay, Phillipa; dos Santos Filho, Celso Alves; Claudino, Angélica
2017-01-01
Recurrent binge eating episodes, the core feature of Bulimia Nervosa (BN) and Binge Eating Disorder (BED), are frequently comorbid with obesity. Psychological interventions, notably Cognitive Behavioural Therapy (CBT), are effective for binge eating reduction in BED or BN but less so for weight loss. Behavioural Weight Loss Therapy (BWLT) shows effectiveness for binge eating reduction and weight loss but the latter appears poorly sustained over time. Our aim was to review evidence for efficacy of psychological therapies for BN/BED associated with overweight or obesity in reducing binge frequency and weight. A systematic search for randomized controlled trials with adult samples who had BN or BED was conducted considering articles in English, French, Spanish and Portuguese with no restrictions for the timeline publication ending in March 2016. A quality appraisal of the trials and meta-analyses comparing BWLT to CBT were done. This review identified 2248 articles for screening and 19 published articles were selected. No trials of BN were identified. This review found CBT was favoured compared to BWLT with regard to short-term binge eating reduction. However, insufficient evidence was found for superiority for BWLT efficacy compared to CBT considering binge eating remission, reduction of binge eating frequency and weight loss. More research is needed to test the efficacy of psychological treatments for BED or BN with co-morbid overweight or obesity, including trials evaluating binge eating remission and weight loss in the long-term. PMID:28304341
Palavras, Marly Amorim; Hay, Phillipa; Filho, Celso Alves Dos Santos; Claudino, Angélica
2017-03-17
Recurrent binge eating episodes, the core feature of Bulimia Nervosa (BN) and Binge Eating Disorder (BED), are frequently comorbid with obesity. Psychological interventions, notably Cognitive Behavioural Therapy (CBT), are effective for binge eating reduction in BED or BN but less so for weight loss. Behavioural Weight Loss Therapy (BWLT) shows effectiveness for binge eating reduction and weight loss but the latter appears poorly sustained over time. Our aim was to review evidence for efficacy of psychological therapies for BN/BED associated with overweight or obesity in reducing binge frequency and weight. A systematic search for randomized controlled trials with adult samples who had BN or BED was conducted considering articles in English, French, Spanish and Portuguese with no restrictions for the timeline publication ending in March 2016. A quality appraisal of the trials and meta-analyses comparing BWLT to CBT were done. This review identified 2248 articles for screening and 19 published articles were selected. No trials of BN were identified. This review found CBT was favoured compared to BWLT with regard to short-term binge eating reduction. However, insufficient evidence was found for superiority for BWLT efficacy compared to CBT considering binge eating remission, reduction of binge eating frequency and weight loss. More research is needed to test the efficacy of psychological treatments for BED or BN with co-morbid overweight or obesity, including trials evaluating binge eating remission and weight loss in the long-term.
Komiya, Chikara; Tsuchiya, Kyoichiro; Shiba, Kumiko; Miyachi, Yasutaka; Furuke, Shunsaku; Shimazu, Noriko; Yamaguchi, Shinobu; Kanno, Kazuo; Ogawa, Yoshihiro
2016-01-01
Type 2 diabetes mellitus (T2DM) is associated with a high incidence of non-alcoholic fatty liver disease (NAFLD) related to obesity and insulin resistance. Currently, medical interventions for NAFLD have focused on diet control and exercise to reduce body weight, and there is a requirement for effective pharmacological therapies. Sodium-glucose cotransporter 2 (SGLT2) inhibitors are oral antidiabetic drugs that promote the urinary excretion of glucose by blocking its reabsorption in renal proximal tubules. SGLT2 inhibitors lower blood glucose independent of insulin action and are expected to reduce body weight because of urinary calorie loss. Here we show that an SGLT2 inhibitor ipragliflozin improves hepatic steatosis in high-fat diet-induced and leptin-deficient (ob/ob) obese mice irrespective of body weight reduction. In the obese mice, ipragliflozin-induced hyperphagia occurred to increase energy intake, attenuating body weight reduction with increased epididymal fat mass. There is an inverse correlation between weights of liver and epididymal fat in ipragliflozin-treated obese mice, suggesting that ipragliflozin treatment promotes normotopic fat accumulation in the epididymal fat and prevents ectopic fat accumulation in the liver. Despite increased adiposity, ipragliflozin ameliorates obesity-associated inflammation and insulin resistance in epididymal fat. Clinically, ipragliflozin improves liver dysfunction in patients with T2DM irrespective of body weight reduction. These findings provide new insight into the effects of SGLT2 inhibitors on energy homeostasis and fat accumulation and indicate their potential therapeutic efficacy in T2DM-associated hepatic steatosis.
Weight Stigma Reduction and Genetic Determinism
Hilbert, Anja
2016-01-01
One major approach to weight stigma reduction consists of decreasing beliefs about the personal controllability of—and responsibility for—obesity by educating about its biogenetic causes. Evidence on the efficacy of this approach is mixed, and it remains unclear whether this would create a deterministic view, potentially leading to detrimental side-effects. Two independent studies from Germany using randomized designs with delayed-intervention control groups served to (1) develop and pilot a brief, interactive stigma reduction intervention to educate N = 128 university students on gene × environment interactions in the etiology of obesity; and to (2) evaluate this intervention in the general population (N = 128) and determine mechanisms of change. The results showed (1) decreased weight stigma and controllability beliefs two weeks post-intervention in a student sample; and (2) decreased internal attributions and increased genetic attributions, knowledge, and deterministic beliefs four weeks post-intervention in a population sample. Lower weight stigma was longitudinally predicted by a decrease in controllability beliefs and an increase in the belief in genetic determinism, especially in women. The results underline the usefulness of a brief, interactive intervention promoting an interactionist view of obesity to reduce weight stigma, at least in the short term, lending support to the mechanisms of change derived from attribution theory. The increase in genetic determinism that occurred despite the intervention’s gene × environment focus had no detrimental side-effect on weight stigma, but instead contributed to its reduction. Further research is warranted on the effects of how biogenetic causal information influences weight management behavior of individuals with obesity. PMID:27631384
Weight Stigma Reduction and Genetic Determinism.
Hilbert, Anja
2016-01-01
One major approach to weight stigma reduction consists of decreasing beliefs about the personal controllability of-and responsibility for-obesity by educating about its biogenetic causes. Evidence on the efficacy of this approach is mixed, and it remains unclear whether this would create a deterministic view, potentially leading to detrimental side-effects. Two independent studies from Germany using randomized designs with delayed-intervention control groups served to (1) develop and pilot a brief, interactive stigma reduction intervention to educate N = 128 university students on gene × environment interactions in the etiology of obesity; and to (2) evaluate this intervention in the general population (N = 128) and determine mechanisms of change. The results showed (1) decreased weight stigma and controllability beliefs two weeks post-intervention in a student sample; and (2) decreased internal attributions and increased genetic attributions, knowledge, and deterministic beliefs four weeks post-intervention in a population sample. Lower weight stigma was longitudinally predicted by a decrease in controllability beliefs and an increase in the belief in genetic determinism, especially in women. The results underline the usefulness of a brief, interactive intervention promoting an interactionist view of obesity to reduce weight stigma, at least in the short term, lending support to the mechanisms of change derived from attribution theory. The increase in genetic determinism that occurred despite the intervention's gene × environment focus had no detrimental side-effect on weight stigma, but instead contributed to its reduction. Further research is warranted on the effects of how biogenetic causal information influences weight management behavior of individuals with obesity.
Urban e-Mobility - Challenges and potential solutions using the example of the "E3W" concept vehicle
NASA Astrophysics Data System (ADS)
Perterer, M.; Martin, P.; Lochner, H.
2014-05-01
Due to the increasing number of people in urban areas, there is a need for affordable individual transportation. Limited space in cities together with the need for a significant reduction of pollution will lead to new mobility concepts in the near future. The aim of these concepts is not replacing the car itself, but to supply an additional personal transportation solution with local zero emission. Therefore, electrical powered vehicle concepts may be used. Due to the limited energy density and high cost of current Li-ion batteries, a significant weight reduction of the vehicle could lead to acceptable range and cost. In order to develop an affordable urban concept, the requirements for this kind of vehicle also have to be adjusted in comparison to conventional cars. This concept, the so called "E3W", combines the advantages of a two-wheeler with those of a four-wheeler, resulting in a lightweight and compact vehicle. This concept accommodates space for two persons with luggage and guarantees a high level of safety including wind and weather protection. The overall measures of this vehicle are smaller than current compact cars and allow therefore better use in cities. In order to fulfill technical and commercial requirements, a load carrying, short fiber reinforced thermoplastic body structure is chosen, combining good weight specific mechanical properties and low production costs. This highly integrated body structure also provides the body cover all in one. Pultruded glass fiber reinforced plastic (GFRP) beams are used as the backbone for the vehicle by carrying the main loads, the front crash structure and the rear swingarm. Finally, two prototypes are built to investigate the driving behavior, proof the concept and the suitability for daily use.
Glueck, Charles J; Aregawi, Dawit; Agloria, Mahlia; Winiarska, Magdalena; Sieve, Luann; Wang, Ping
2006-12-01
In 74 women with polycystic ovary syndrome, treated for 4 years with metformin (MET) and diet, we prospectively assessed whether, and to what degree, weight loss, reduction of insulin resistance, and amelioration of coronary heart disease risk factors could be sustained. We hypothesized that response to MET-diet would not differ by pretreatment body mass index (BMI) classes <25 (normal), > or =25 to <30 (overweight), > or =30 to <40 (obese), and > or =40 (extremely obese). [table: see text] Metformin-diet was successful in producing stable approximately 8% weight reduction for all 4 years (trend P < .0001). Percentage of reductions in weight on MET-diet was significant (P < .05) and did not differ among the 3 highest BMI categories (> or =40, > or =30 to <40, > or =25 to <30), but were not significant in the normal-weight category (BMI, <25). On MET-diet, median homeostasis model assessment of insulin resistance (HOMA-IR) was 33% lower than entry at 1 year, 50% at 2 years, 51% at 3 years, and 50% at 4 years (trend, P < .0001). On MET-diet, median low-density lipoprotein cholesterol (LDL-C) was 6% lower than entry at year 1, 6% at year 2, 7% at year 3, and 11% at year 4 (trend P < .0001). On MET-diet, median high-density lipoprotein cholesterol (HDL-C) was 3% higher than entry at year 2, 8% higher at year 3, and 11% higher at year 4 (trend P < .0001). Percentage of reductions in HOMA-IR, LDL-C, triglyceride, and systolic blood pressure, and increments in HDL-C did not differ (P > .1) in the 4 BMI categories. By stepwise regression, weight loss was a significant (P < or = .01) positive explanatory variable for reduction in HOMA-IR for all 4 follow-up years. Metformin-diet in women with polycystic ovary syndrome effectively and safely reduces weight and LDL-C while raising HDL-C, and maintains these outcomes stable over 4 years.
Hologram interferometry in automotive component vibration testing
NASA Astrophysics Data System (ADS)
Brown, Gordon M.; Forbes, Jamie W.; Marchi, Mitchell M.; Wales, Raymond R.
1993-02-01
An ever increasing variety of automotive component vibration testing is being pursued at Ford Motor Company, U.S.A. The driving force for use of hologram interferometry in these tests is the continuing need to design component structures to meet more stringent functional performance criteria. Parameters such as noise and vibration, sound quality, and reliability must be optimized for the lightest weight component possible. Continually increasing customer expectations and regulatory pressures on fuel economy and safety mandate that vehicles be built from highly optimized components. This paper includes applications of holographic interferometry for powertrain support structure tuning, body panel noise reduction, wiper system noise and vibration path analysis, and other vehicle component studies.
NASA Astrophysics Data System (ADS)
Elbing, Brian R.; Winkel, Eric S.; Ceccio, Steven L.; Perlin, Marc; Dowling, David R.
2010-08-01
Wall-pressure fluctuations were investigated within a high-Reynolds-number turbulent boundary layer (TBL) modified by the addition of dilute friction-drag-reducing polymer solutions. The experiment was conducted at the U.S. Navy's Large Cavitation Channel on a 12.9 m long flat-plate test model with the surface hydraulically smooth (k+<0.2) and achieving downstream-distance-based Reynolds numbers to 220×106. The polymer (polyethylene oxide) solution was injected into the TBL through a slot in the surface. The primary flow diagnostics were skin-friction drag balances and an array of flush-mounted dynamic pressure transducers 9.8 m from the model leading edge. Parameters varied included the free-stream speed (6.7, 13.4, and 20.2 m s-1) and the injection condition (polymer molecular weight, injection concentration, and volumetric injection flux). The behavior of the pressure spectra, convection velocity, and coherence, regardless of the injection condition, were determined primarily based on the level of drag reduction. Results were divided into two regimes dependent on the level of polymer drag reduction (PDR), nominally separated at a PDR of 40%. The low-PDR regime is characterized by decreasing mean-square pressure fluctuations and increasing convection velocity with increasing drag reduction. This shows that the decrease in the pressure spectra with increasing drag reduction is due in part to the moving of the turbulent structures from the wall. Conversely, with further increases in drag reduction, the high-PDR regime has negligible variation in the mean-squared pressure fluctuations and convection velocity. The convection velocity remains constant at approximately 10% above the baseline-flow convection velocity, which suggests that the turbulent structures no longer move farther from the wall with increasing drag reduction. In light of recent numerical work, the coherence results indicate that in the low-PDR regime, the turbulent structures are being elongated in the streamwise direction and occurring at decreasing frequency. In the high-PDR regime, the rate of occurrence continues to decrease until large-scale coherent turbulent structures are potentially no longer present.
Anaerobic microbial redox processes in a landfill leachate contaminated aquifer (Grindsted, Denmark)
NASA Astrophysics Data System (ADS)
Ludvigsen, L.; Albrechtsen, H.-J.; Heron, G.; Bjerg, P. L.; Christensen, T. H.
1998-10-01
The distribution of anaerobic microbial redox processes was investigated along a 305 m long transect of a shallow landfill-leachate polluted aquifer. By unamended bioassays containing sediment and groundwater, 37 samples were investigated with respect to methane production, sulfate, iron, and manganese reduction, and denitrification. Methane production was restricted to the most reduced part of the plume with rates of 0.003-0.055 nmol CH 4/g dry weight/day. Sulfate reduction was observed at rates of maximum 1.8 nmol SO 42-/g dry weight/day along with methane production in the plume, but sulfate reduction was also observed further downgradient of the landfill. Iron reduction at rates of 5-19 nmol Fe(II)/g dry weight/day was observed in only a few samples, but this may be related to a high detection limit for the iron reducing bioassay. Manganese reduction at rates of maximum 2.4 nmol Mn(II)/g dry weight/day and denitrification at rates of 0.2-37 nmol N 2O-N/g dry weight/day were observed in the less reduced part of the plume. All the redox processes were microbial processes. In many cases, several redox processes took place simultaneously, but in all samples one process dominated accounting for more than 70% of the equivalent carbon conversion. The bioassays showed that the redox zones in the plume identified from the groundwater composition (e.g. as methanogenic and sulfate reducing) locally hosted also other redox processes (e.g. iron reduction). This may have implications for the potential of the redox zone to degrade trace amounts of organic chemicals and suggests that unamended bioassays may be an important supplement to other approaches in characterizing the redox processes in an anaerobic plume.
Technology needs for high speed rotorcraft (2)
NASA Technical Reports Server (NTRS)
Scott, Mark W.
1991-01-01
An analytical study was conducted to identify rotorcraft concepts best capable of combining a cruise speed of 350 to 450 knots with helicopter-like low speed attributes, and to define the technology advancements needed to make them viable by the year 2000. A systematic approach was used to compare the relative attributes and mission gross weights for a wide range of concepts, resulting in a downselect to the most promising concept/mission pairs. For transport missions, tilt-wing and variable diameter tilt-rotor (VDTR) concepts were found to be superior. For a military scout/attack role, the VDTR was best, although a shrouded rotor concept could provide a highly agile, low observable alternative if its weight empty fraction could be reduced. A design speed of 375 to 425 knots was found to be the maximum desirable for transport missions, with higher speed producing rapidly diminishing benefits in productivity. The key technologies that require advancement to make the tilt-wing and VDTR concepts viable are in the areas of wing and proprotor aerodynamics, efficient structural design, flight controls, refinement of the geared flap pitch control system, expansion of the speed/descent envelope, and the structural and aerodynamic tradeoffs of wing thickness and forward sweep. For the shrouded rotor, weight reduction is essential, particularly with respect to the mechanism for covering the rotor in cruise.
NASA Astrophysics Data System (ADS)
Joost, William J.
2012-09-01
Transportation accounts for approximately 28% of U.S. energy consumption with the majority of transportation energy derived from petroleum sources. Many technologies such as vehicle electrification, advanced combustion, and advanced fuels can reduce transportation energy consumption by improving the efficiency of cars and trucks. Lightweight materials are another important technology that can improve passenger vehicle fuel efficiency by 6-8% for each 10% reduction in weight while also making electric and alternative vehicles more competitive. Despite the opportunities for improved efficiency, widespread deployment of lightweight materials for automotive structures is hampered by technology gaps most often associated with performance, manufacturability, and cost. In this report, the impact of reduced vehicle weight on energy efficiency is discussed with a particular emphasis on quantitative relationships determined by several researchers. The most promising lightweight materials systems are described along with a brief review of the most significant technical barriers to their implementation. For each material system, the development of accurate material models is critical to support simulation-intensive processing and structural design for vehicles; improved models also contribute to an integrated computational materials engineering (ICME) approach for addressing technical barriers and accelerating deployment. The value of computational techniques is described by considering recent ICME and computational materials science success stories with an emphasis on applying problem-specific methods.
Ineffectiveness of human chorionic gonadotropin in weight reduction: a double-blind study.
Stein, M R; Julis, R E; Peck, C C; Hinshaw, W; Sawicki, J E; Deller, J J
1976-09-01
Our investigation was designed to retest the hypothesis of the efficacy of human chorionic gonadotropin (HCG) on weight reduction in obese women in a clinic setting. We sought to duplicate the Asher-Harper study (1973) which had found that the combination of 500 cal diet and HCG had a statistically significant benefit over the diet and placebo combination as evidenced by greater weight loss and decrease in hunger. Fifty-one women between the ages of 18 and 60 participated in our 32-day prospective, randomized, double-blind comparison of HCG versus placebo. Each patient was given the same diet (the one prescribed in the Asher-Harper study), was weighed daily Monday through Saturday and was counselled by one of the investigators who administered the injections. Laboratory studies were performed at the time of initial physical examinations and at the end of the study. Twenty of 25 in the HCG and 21 of 26 patients in the placebo groups completed 28 injections. There was no statistically significant difference in the means of the two groups in number of injections received, weight loss, percent of weight loss, hip and waist circumference, weight loss per injections, or in hunger ratings. HCG does not appear to enhance the effectiveness of a rigidly imposed regimen for weight reduction.
Gilis-Januszewska, Aleksandra; Piwońska-Solska, Beata; Lindström, Jaana; Wójtowicz, Ewa; Tuomilehto, Jaakko; Schwarz, Peter E H; Kissimova-Skarbek, Katarzyna; Szybiński, Zbigniew; Windak, Adam; Hubalewska-Dydejczyk, Alicja
2018-01-02
Real life implementation studies performed in different settings have proved that lifestyle interventions in the prevention of type 2 diabetes (DM2) can be effective, although the weight reduction results are typically modest compared to randomized control trials. Our objective was to identify the factors that predict successful weight loss in a less intensive, lower budget, real life setting lifestyle diabetes prevention intervention. Study participants (n = 175) with increased DM2 risk (Finnish Diabetes Risk Score (FINDRISC) > 14) but no diabetes at baseline received ten group lifestyle counselling sessions, physical activity and motivation sessions during a ten-month intervention. Stepwise regression analysis was used to determine demographic, clinical, and lifestyle predictors of successful weight reduction defined as a reduction of ≥5% of the initial body weight. At 12 months following the initiation of the intervention, 23.4% of study participants lost ≥5% weight (mean loss of 7.9 kg, SD = 5.8). Increased physical activity (44% vs 25%, p = 0.03), decreased total fat consumption (88% vs 65%, p = 0.006) and adherence to four-five lifestyle goals (71% vs 46%, p = 0.007) were more often reported among those who managed to lose ≥5% weight versus those who did not. In a multivariate analysis, meeting the ≥5% weight loss goal was most effective in individuals with a higher baseline BMI (OR 1.1, 95%CI 1.0-1.2), baseline and medium versus higher education (OR 5.4, 95% CI 1.2-24.7) and a history of increased glucose (OR 2.6, 95%CI 1.1-1.3). A reduction of total fat in the diet was an independent lifestyle predictor, increasing the probability of successful weight loss by 3.8 times (OR 3.8, 95% CI 1.2-11.4). Baseline higher BMI, lower education and a history of increased glucose predicted the successful weight loss among individuals with a high risk for the DM2 following lifestyle intervention in a real life primary health care setting. People who manage to lose weight more often adhere to lifestyle changes, while the reduction of total fat in diet independently predicts successful weight loss. Further studies exploring the predictors of success in implementation studies in DM2 prevention should help health care providers redesign interventions to improve their effectiveness and outcomes. ISRCTN, ID ISRCTN96692060 , registered 03.08.2016 retrospectively.
Structural Considerations of a 20MW Multi-Rotor Wind Energy System
NASA Astrophysics Data System (ADS)
Jamieson, P.; Branney, M.
2014-12-01
The drive to upscale offshore wind turbines relates especially to possiblereductions in O&M and electrical interconnection costs per MW of installed capacity.Even with best current technologies, designs with rated capacity above about 3 MW are less cost effective exfactory per rated MW(turbine system costs) than smaller machines.Very large offshore wind turbines are thereforejustifiedprimarily by overall offshore project economics. Furthermore, continuing progress in materials and structures has been essential to avoid severe penalties in the power/mass ratio of large multi-MW machines.The multi-rotor concept employs many small rotors to maximise energy capture area withminimum systemvolume. Previous work has indicated that this can enablea very large reduction in the total weight and cost of rotors and drive trains compared to an equivalent large single rotor system.Thus the multi rotor concept may enable rated capacities of 20 MW or more at a single maintenancesite. Establishing the cost benefit of a multi rotor system requires examination of solutions for the support structure and yawing, ensuring aerodynamic losses from rotor interaction are not significant and that overall logistics, with much increased part count (more reliable components) and less consequence of single failuresare favourable. This paper addresses the viability of a support structure in respect of structural concept and likely weight as one necessary step in exploring the potential of the multi rotor concept.
Shao, Junming; Meng, Chun; Tahmasian, Masoud; Brandl, Felix; Yang, Qinli; Luo, Guangchun; Luo, Cheng; Yao, Dezhong; Gao, Lianli; Riedl, Valentin; Wohlschläger, Afra; Sorg, Christian
2018-02-19
Brain imaging reveals schizophrenia as a disorder of macroscopic brain networks. In particular, default mode and salience network (DMN, SN) show highly consistent alterations in both interacting brain activity and underlying brain structure. However, the same networks are also altered in major depression. This overlap in network alterations induces the question whether DMN and SN changes are different across both disorders, potentially indicating distinct underlying pathophysiological mechanisms. To address this question, we acquired T1-weighted, diffusion-weighted, and resting-state functional MRI in patients with schizophrenia, patients with major depression, and healthy controls. We measured regional gray matter volume, inter-regional structural and intrinsic functional connectivity of DMN and SN, and compared these measures across groups by generalized Wilcoxon rank tests, while controlling for symptoms and medication. When comparing patients with controls, we found in each patient group SN volume loss, impaired DMN structural connectivity, and aberrant DMN and SN functional connectivity. When comparing patient groups, SN gray matter volume loss and DMN structural connectivity reduction did not differ between groups, but in schizophrenic patients, functional hyperconnectivity between DMN and SN was less in comparison to depressed patients. Results provide evidence for distinct functional hyperconnectivity between DMN and SN in schizophrenia and major depression, while structural changes in DMN and SN were similar. Distinct hyperconnectivity suggests different pathophysiological mechanism underlying aberrant DMN-SN interactions in schizophrenia and depression.
Lee, Seung Jae; Choi, Eun Ju; Kwon, Jun Soo
2008-04-01
The primary aim of this study was to examine the efficacy and feasibility of a weight control program for overweight and obese patients with schizophrenia or schizoaffective disorder using a large sample across various clinical settings. Psychiatric patients taking antipsychotics participated in a 12-week weight management program at 33 clinical centers across South Korea, and the data for 232 subjects who had a body mass index (BMI) 25 kg/m(2) or above and were diagnosed with DSM-IV schizophrenia or schizoaffective disorder were used in the final analysis. The primary measures of efficacy were changes in body weight and BMI. The study was conducted from December 2005 to July 2006. These patients showed significant mean +/- SD reductions in BMI (0.98 +/- 1.01 kg/m(2), p < .001) and body weight (2.64 +/- 2.75 kg, p < .001), with moderate compliance, after the 12-week intervention. Diet compliance was the strongest single predictor of weight loss. Although significant differences in BMI reduction occurred between groups classified by clinical setting and compliance, all sex, age, clinical setting, compliance, and initial BMI groups showed significant BMI reductions, which fell between 0.4 and 1.5 kg/m(2). Overall results suggest that a weight management program may be disseminated and adopted by practitioners across settings, resulting in short-term weight loss in schizophrenic and schizoaffective patients.
The effect of environmental tobacco smoke during pregnancy on birth weight.
Hegaard, Hanne K; Kjaergaard, Hanne; Møller, Lars F; Wachmann, Henrik; Ottesen, Bent
2006-01-01
This study explores whether pregnant nonsmokers' exposure to environmental tobacco smoke (ETS) affects the average birth weight at term. The population studied consists of pregnant nonsmokers participating in a study called Smoke-free Newborn Study. The participants (n = 1612) answered a questionnaire during 12th to 16th gestational week about their exposure to ETS at home and outside the home. Pregnant nonsmokers exposed to ETS both at home and outside the home gave birth to children with a birth weight of 78.9 g (95% CI -143.7 to -14.1) (P=0.02) lower than the weight of children born to women unexposed to ETS. There was no significant reduction in birth weight among women exposed to ETS at home only or outside the home only. A nonsignificant dose-response association was seen between increasing daily exposure to ETS and reduction in birth weight. Nonsmoking pregnant women who were exposed to ETS at home as well as outside the home gave birth to children with a 79 g reduction in birth weight compared to children of unexposed women. The fact that exposure to ETS has an effect on the birth weight is regarded as essential. The authors recommend that pregnant women should not be exposed to passive smoking, and that it should be considered whether workplace legislation should be instituted in order to protect pregnant women against the adverse effects of passive smoking.
Wispy Prosthesis: A Novel Method in Denture Weight Reduction
Anne, Gopinadh; Budeti, Sreedevi; Anche, Sampath Kumar; Zakkula, Srujana; Atla, Jyothi; Jyothula, Ravi Rakesh Dev; Peddinti, Vijaya Kumar
2016-01-01
Introduction Stability and retention of the denture becomes at stake with the increase in weight of the denture prosthesis. As a consequence, different materials and methods have been introduced to overcome these issues but denture weight reduction still remains to be a cumbersome and strenuous procedure. Aim To introduce a novel technique for the fabrication of denture prosthesis where in the weight of the denture will not affect the retention and stability of the denture. Materials and Methods Four groups with a sample size of 10 each, were included where in one group was control and other three were study groups. The control group samples were made completely solid and the study group samples were packed with materials like bean balls, cellulose balls and polyacrylic fibers. The weight of all the samples of each study group was measured and compared with the control group. The observations were analyzed statistically by paired t-test. Results It was observed that the bean balls group produced a weight reduction of 31.3%, cellulose balls group 27.4% and polyacrylic fibers group 24.5% when compared to that of the control group. Conclusion This novel technique will eliminate the problems that were associated in creating hollowness and at the same time will reduce the weight of the prosthesis and among all the study groups, bean balls group were found to reduce maximum weight of the prosthesis. PMID:27190947
Wispy Prosthesis: A Novel Method in Denture Weight Reduction.
Anne, Gopinadh; Budeti, Sreedevi; Anche, Sampath Kumar; Zakkula, Srujana; Atla, Jyothi; Jyothula, Ravi Rakesh Dev; Appana, Krishna Chaitanya; Peddinti, Vijaya Kumar
2016-04-01
Stability and retention of the denture becomes at stake with the increase in weight of the denture prosthesis. As a consequence, different materials and methods have been introduced to overcome these issues but denture weight reduction still remains to be a cumbersome and strenuous procedure. To introduce a novel technique for the fabrication of denture prosthesis where in the weight of the denture will not affect the retention and stability of the denture. Four groups with a sample size of 10 each, were included where in one group was control and other three were study groups. The control group samples were made completely solid and the study group samples were packed with materials like bean balls, cellulose balls and polyacrylic fibers. The weight of all the samples of each study group was measured and compared with the control group. The observations were analyzed statistically by paired t-test. It was observed that the bean balls group produced a weight reduction of 31.3%, cellulose balls group 27.4% and polyacrylic fibers group 24.5% when compared to that of the control group. This novel technique will eliminate the problems that were associated in creating hollowness and at the same time will reduce the weight of the prosthesis and among all the study groups, bean balls group were found to reduce maximum weight of the prosthesis.
Lindholm, Asa; Bixo, Marie; Björn, Inger; Wölner-Hanssen, Pål; Eliasson, Mats; Larsson, Anders; Johnson, Owe; Poromaa, Inger Sundström
2008-05-01
To examine the efficacy of sibutramine together with brief lifestyle modification for weight reduction in obese women with polycystic ovary syndrome (PCOS). Investigator-initiated, multicenter, double-blind, randomized, parallel-group clinical trial. Departments of Obstetrics and Gynecology in primary care, referral centers, and private practice. Forty-two patients with confirmed PCOS were included in the study, and 34 patients completed the study. Sibutramine 15 mg once daily together with brief lifestyle modification was compare with placebo together with brief lifestyle modification. The primary endpoint was to assess weight loss. Secondary endpoints included the efficacy of sibutramine for treatment of menstrual pattern and cardiovascular risk factors. After 6 months the sibutramine group had lost 7.8 +/- 5.1 kg compared with a weight loss of 2.8 +/- 6.2 kg in the placebo group. Sibutramine treatment resulted in significant decreases in apolipoprotein B, apolipoprotein B/apolipoprotein A ratio, triglycerides, and cystatin C levels. Sibutramine in combination with lifestyle intervention results in significant weight reduction in obese patients with PCOS. In addition to the weight loss, sibutramine seems to have beneficial effects on metabolic and cardiovascular risk factors.
Link between Food Energy Density and Body Weight Changes in Obese Adults
Stelmach-Mardas, Marta; Rodacki, Tomasz; Dobrowolska-Iwanek, Justyna; Brzozowska, Anna; Walkowiak, Jarosław; Wojtanowska-Krosniak, Agnieszka; Zagrodzki, Paweł; Bechthold, Angela; Mardas, Marcin; Boeing, Heiner
2016-01-01
Regulating the energy density of food could be used as a novel approach for successful body weight reduction in clinical practice. The aim of this study was to conduct a systemic review of the literature on the relationship between food energy density and body weight changes in obese adults to obtain solid evidence supporting this approach. The search process was based on the selection of publications in the English language listed in public databases. A meta-analysis was performed to combine individual study results. Thirteen experimental and observational studies were identified and included in the final analysis. The analyzed populations consist of 3628 individuals aged 18 to 66 years. The studies varied greatly in terms of study populations, study design and applied dietary approaches. The meta-analysis revealed a significant association between low energy density foods and body weight reduction, i.e., −0.53 kg when low energy density foods were eaten (95% CI: −0.88, −0.19). In conclusions, this study adds evidence which supports the energy density of food as a simple but effective measure to manage weight in the obese with the aim of weight reduction. PMID:27104562
Harris, Wendy; Zhang, You; Yin, Fang-Fang; Ren, Lei
2017-01-01
Purpose To investigate the feasibility of using structural-based principal component analysis (PCA) motion-modeling and weighted free-form deformation to estimate on-board 4D-CBCT using prior information and extremely limited angle projections for potential 4D target verification of lung radiotherapy. Methods A technique for lung 4D-CBCT reconstruction has been previously developed using a deformation field map (DFM)-based strategy. In the previous method, each phase of the 4D-CBCT was generated by deforming a prior CT volume. The DFM was solved by a motion-model extracted by global PCA and free-form deformation (GMM-FD) technique, using a data fidelity constraint and deformation energy minimization. In this study, a new structural-PCA method was developed to build a structural motion-model (SMM) by accounting for potential relative motion pattern changes between different anatomical structures from simulation to treatment. The motion model extracted from planning 4DCT was divided into two structures: tumor and body excluding tumor, and the parameters of both structures were optimized together. Weighted free-form deformation (WFD) was employed afterwards to introduce flexibility in adjusting the weightings of different structures in the data fidelity constraint based on clinical interests. XCAT (computerized patient model) simulation with a 30 mm diameter lesion was simulated with various anatomical and respirational changes from planning 4D-CT to onboard volume to evaluate the method. The estimation accuracy was evaluated by the Volume-Percent-Difference (VPD)/Center-of-Mass-Shift (COMS) between lesions in the estimated and “ground-truth” on board 4D-CBCT. Different onboard projection acquisition scenarios and projection noise levels were simulated to investigate their effects on the estimation accuracy. The method was also evaluated against 3 lung patients. Results The SMM-WFD method achieved substantially better accuracy than the GMM-FD method for CBCT estimation using extremely small scan angles or projections. Using orthogonal 15° scanning angles, the VPD/COMS were 3.47±2.94% and 0.23±0.22mm for SMM-WFD and 25.23±19.01% and 2.58±2.54mm for GMM-FD among all 8 XCAT scenarios. Compared to GMM-FD, SMM-WFD was more robust against reduction of the scanning angles down to orthogonal 10° with VPD/COMS of 6.21±5.61% and 0.39±0.49mm, and more robust against reduction of projection numbers down to only 8 projections in total for both orthogonal-view 30° and orthogonal-view 15° scan angles. SMM-WFD method was also more robust than the GMM-FD method against increasing levels of noise in the projection images. Additionally, the SMM-WFD technique provided better tumor estimation for all three lung patients compared to the GMM-FD technique. Conclusion Compared to the GMM-FD technique, the SMM-WFD technique can substantially improve the 4D-CBCT estimation accuracy using extremely small scan angles and low number of projections to provide fast low dose 4D target verification. PMID:28079267
Prakash, Priyanka; Gilman, Matthew D.; Shepard, Jo-Anne O.; Digumarthy, Subba R.
2010-01-01
Objective To assess the effects of radiation dose reduction in the chest CT using a weight-based adjustment of the automatic exposure control (AEC) technique. Materials and Methods With Institutional Review Board Approval, 60 patients (mean age, 59.1 years; M:F = 35:25) and 57 weight-matched patients (mean age, 52.3 years, M:F = 25:32) were scanned using a weight-adjusted AEC and non-weight-adjusted AEC, respectively on a 64-slice multidetector CT with a 0.984:1 pitch, 0.5 second rotation time, 40 mm table feed/rotation, and 2.5 mm section thickness. Patients were categorized into 3 weight categories; < 60 kg (n = 17), 60-90 kg (n = 52), and > 90 kg (n = 48). Patient weights, scanning parameters, CT dose index volumes (CTDIvol) and dose length product (DLP) were recorded, while effective dose (ED) was estimated. Image noise was measured in the descending thoracic aorta. Data were analyzed using a standard statistical package (SAS/STAT) (Version 9.1, SAS institute Inc, Cary, NC). Results Compared to the non-weight-adjusted AEC, the weight-adjusted AEC technique resulted in an average decrease of 29% in CTDIvol and a 27% effective dose reduction (p < 0.0001). With weight-adjusted AEC, the CTDIvol decreased to 15.8, 15.9, and 27.3 mGy for the < 60, 60-90 and > 91 kg weight groups, respectively, compared to 20.3, 27.9 and 32.8 mGy, with non-weight-adjusted AEC. No significant difference was observed for objective image noise between the chest CT acquired with the non-weight-adjusted (15.0 ± 3.1) and weight-adjusted (16.1 ± 5.6) AEC techniques (p > 0.05). Conclusion The results of this study suggest that AEC should be tailored according to patient weight. Without weight-based adjustment of AEC, patients are exposed to a 17 - 43% higher radiation-dose from a chest CT. PMID:20046494
Prakash, Priyanka; Kalra, Mannudeep K; Gilman, Matthew D; Shepard, Jo-Anne O; Digumarthy, Subba R
2010-01-01
To assess the effects of radiation dose reduction in the chest CT using a weight-based adjustment of the automatic exposure control (AEC) technique. With Institutional Review Board Approval, 60 patients (mean age, 59.1 years; M:F = 35:25) and 57 weight-matched patients (mean age, 52.3 years, M:F = 25:32) were scanned using a weight-adjusted AEC and non-weight-adjusted AEC, respectively on a 64-slice multidetector CT with a 0.984:1 pitch, 0.5 second rotation time, 40 mm table feed/rotation, and 2.5 mm section thickness. Patients were categorized into 3 weight categories; < 60 kg (n = 17), 60-90 kg (n = 52), and > 90 kg (n = 48). Patient weights, scanning parameters, CT dose index volumes (CTDIvol) and dose length product (DLP) were recorded, while effective dose (ED) was estimated. Image noise was measured in the descending thoracic aorta. Data were analyzed using a standard statistical package (SAS/STAT) (Version 9.1, SAS institute Inc, Cary, NC). Compared to the non-weight-adjusted AEC, the weight-adjusted AEC technique resulted in an average decrease of 29% in CTDIvol and a 27% effective dose reduction (p < 0.0001). With weight-adjusted AEC, the CTDIvol decreased to 15.8, 15.9, and 27.3 mGy for the < 60, 60-90 and > 91 kg weight groups, respectively, compared to 20.3, 27.9 and 32.8 mGy, with non-weight-adjusted AEC. No significant difference was observed for objective image noise between the chest CT acquired with the non-weight-adjusted (15.0 +/- 3.1) and weight-adjusted (16.1 +/- 5.6) AEC techniques (p > 0.05). The results of this study suggest that AEC should be tailored according to patient weight. Without weight-based adjustment of AEC, patients are exposed to a 17 - 43% higher radiation-dose from a chest CT.
ERIC Educational Resources Information Center
Lublin, Irwin; Kirkish, Patricia
This description of a weight reduction program, based on generalizations derived from eight years of work with overweight persons, discusses the clients' rationalization of overeating behaviors. In this behavior modification program, the client is required to permanently give up one high calorie food and to write down all foods eaten before actual…
The contractor will conduct an independent peer review of FEV’s light-duty truck (LDT) mass safety study, “Light-Duty Vehicle Weight Reduction Study with Crash Model, Feasibility and Detailed Cost Analysis – Silverado 1500”, and its corresponding computer-aided engineering (CAE) ...
Formation Flight System Extremum-Seeking-Control Using Blended Performance Parameters
NASA Technical Reports Server (NTRS)
Ryan, John J. (Inventor)
2018-01-01
An extremum-seeking control system for formation flight that uses blended performance parameters in a conglomerate performance function that better approximates drag reduction than performance functions formed from individual measurements. Generally, a variety of different measurements are taken and fed to a control system, the measurements are weighted, and are then subjected to a peak-seeking control algorithm. As measurements are continually taken, the aircraft will be guided to a relative position which optimizes the drag reduction of the formation. Two embodiments are discussed. Two approaches are shown for determining relative weightings: "a priori" by which they are qualitatively determined (by minimizing the error between the conglomerate function and the drag reduction function), and by periodically updating the weightings as the formation evolves.
Body Weight Gain and Hyperphagia After Administration of SGLT-2 Inhibitor: A Case Report
Hamamoto, Hiromi; Noda, Mitsuhiko
2015-01-01
Patient: Male, 44 Final Diagnosis: Type 2 diabetes Symptoms: Hunger • increased appetite Medication: GLP-1 receptor agonist • SGLT-2 inhibitor Clinical Procedure: — Specialty: Internal Medicine/Diabetology Objective: Unusual or unexpected effect of treatment Background: A detailed description is given of a case we encountered in which unexpectedly marked weight gain occurred following a treatment switch from a GLP-1 receptor agonist to an SGLT-2 inhibitor. Case Report: The patient, a 44-year-old man with type 2 diabetes mellitus, had gained about 10 kg in weight in the previous year. Therefore, metformin was replaced with liraglutide to obtain reduction of body weight. Although the patient lost about 8 kg (7%), during the 18-month period on the medication, the weight loss stabilized; therefore, the treatment was again switched to tofogliflozin to obtain further reduction of body weight. However, the patient reported increasing hunger and an exaggerated appetite from week 3 onward after the start of tofogliflozin, and gained about 9 kg in weight within 2 weeks, associated with a tendency towards increased HbA1c; therefore, tofogliflozin was discontinued. Immediate reinstitution of liraglutide resulted in reduction of the increased appetite, weight, and HbA1c level. Conclusions: Caution should be exercised against hyperphagia and weight gain due to hunger that may occur following discontinuation of a GLP-1 receptor agonist and/or initiation of an SGLT-2 inhibitor. PMID:26638727
Murphy, Joan C.; McDaniel, Jennifer L.; Mora, Katherine; Villareal, Dennis T.; Fontana, Luigi
2012-01-01
Intermuscular adipose tissue (IMAT) and visceral adipose tissue (VAT) are associated with insulin resistance. We sought to determine whether exercise-induced weight loss (EX) results in greater reductions in IMAT and VAT compared with similar weight loss induced by calorie restriction (CR) and whether these changes are associated with improvements in glucoregulation. Sedentary men and women (50–60 yr; body mass index of 23.5–29.9 kg/m2) were randomized to 1 yr of CR (n = 17), EX (n = 16), or a control group (CON; n = 6). Bilateral thigh IMAT and VAT volumes were quantified using multi-slice magnetic resonance imaging. Insulin sensitivity index (ISI) was determined from oral glucose tolerance test glucose and insulin levels. Weight loss was comparable (P = 0.25) in the CR (−10.8 ± 1.4%) and EX groups (−8.3 ± 1.5%) and greater than in the control group (−2.0 ± 2.4%; P < 0.05). IMAT and VAT reductions were larger in the CR and EX groups than in the CON group (P ≤ 0.05). After controlling for differences in total fat mass change between the CR and EX groups, IMAT and VAT reductions were nearly twofold greater (P ≤ 0.05) in the EX group than in the CR group (IMAT: −45 ±5 vs. −25 ± 5 ml; VAT: −490 ± 64 vs. −267 ± 61 ml). In the EX group, the reductions in IMAT were correlated with increases in ISI (r = −0.71; P = 0.003), whereas in the CR group, VAT reductions were correlated with increases in ISI (r = −0.64; P = 0.006). In conclusion, calorie restriction and exercise-induced weight loss both decrease IMAT and VAT volumes. However, exercise appears to result in preferential reductions in these fat depots. PMID:22016371
NASA Astrophysics Data System (ADS)
Sogaro, Francesca; Poole, Robert; Dennis, David
2014-11-01
High-speed stereoscopic particle image velocimetry has been performed in fully developed turbulent pipe flow at moderate Reynolds numbers with and without a drag-reducing additive (an aqueous solution of high molecular weight polyacrylamide). Three-dimensional large and very large-scale motions (LSM and VLSM) are extracted from the flow fields by a detection algorithm and the characteristics for each case are statistically compared. The results show that the three-dimensional extent of VLSMs in drag reduced (DR) flow appears to increase significantly compared to their Newtonian counterparts. A statistical increase in azimuthal extent of DR VLSM is observed by means of two-point spatial autocorrelation of the streamwise velocity fluctuation in the radial-azimuthal plane. Furthermore, a remarkable increase in length of these structures is observed by three-dimensional two-point spatial autocorrelation. These results are accompanied by an analysis of the swirling strength in the flow field that shows a significant reduction in strength and number of the vortices for the DR flow. The findings suggest that the damping of the small scales due to polymer addition results in the undisturbed development of longer flow structures.
Amplified biosensing using the horseradish peroxidase-mimicking DNAzyme as an electrocatalyst.
Pelossof, Gilad; Tel-Vered, Ran; Elbaz, Johann; Willner, Itamar
2010-06-01
The hemin/G-quadruplex horseradish peroxidase-mimicking DNAzyme is assembled on Au electrodes. It reveals bioelectrocatalytic properties and electrocatalyzes the reduction of H(2)O(2). The bioelectrocatalytic functions of the hemin/G-quadruplex DNAzyme are used to develop electrochemical sensors that follow the activity of glucose oxidase and biosensors for the detection of DNA or low-molecular-weight substrates (adenosine monophosphate, AMP). Hairpin nucleic structures that include the G-quadruplex sequence in a caged configuration and the nucleic acid sequence complementary to the analyte DNA, or the aptamer sequence for AMP, are immobilized on Au-electrode surfaces. In the presence of the DNA analyte, or AMP, the hairpin structures are opened, and the hemin/G-quadruplex horseradish peroxidase-mimicking DNAzyme structures are generated on the electrode surfaces. The bioelectrocatalytic cathodic currents generated by the functionalized electrodes, upon the electrochemical reduction of H(2)O(2), provide a quantitative measure for the detection of the target analytes. The DNA target was analyzed with a detection limit of 1 x 10(-12) M, while the detection limit for analyzing AMP was 1 x 10(-6) M. Methods to regenerate the sensing surfaces are presented.
Suzuki, M; Takeda, M; Kito, A; Fukazawa, M; Yata, T; Yamamoto, M; Nagata, T; Fukuzawa, T; Yamane, M; Honda, K; Suzuki, Y; Kawabe, Y
2014-01-01
Objective: Tofogliflozin, a highly selective inhibitor of sodium/glucose cotransporter 2 (SGLT2), induces urinary glucose excretion (UGE), improves hyperglycemia and reduces body weight in patients with Type 2 diabetes (T2D). The mechanisms of tofogliflozin on body weight reduction were investigated in detail with obese and diabetic animal models. Methods: Diet-induced obese (DIO) rats and KKAy mice (a mouse model of diabetes with obesity) were fed diets containing tofogliflozin. Body weight, body composition, biochemical parameters and metabolic parameters were evaluated. Results: In DIO rats tofogliflozin was administered for 9 weeks, UGE was induced and body weight gain was attenuated. Body fat mass decreased without significant change in bone mass or lean body mass. Food consumption (FC) increased without change in energy expenditure, and deduced total calorie balance (deduced total calorie balance=FC−UGE−energy expenditure) decreased. Respiratory quotient (RQ) and plasma triglyceride (TG) level decreased, and plasma total ketone body (TKB) level increased. Moreover, plasma leptin level, adipocyte cell size and proportion of CD68-positive cells in mesenteric adipose tissue decreased. In KKAy mice, tofogliflozin was administered for 3 or 5 weeks, plasma glucose level and body weight gain decreased together with a reduction in liver weight and TG content without a reduction in body water content. Combination therapy with tofogliflozin and pioglitazone suppressed pioglitazone-induced body weight gain and reduced glycated hemoglobin level more effectively than monotherapy with either pioglitazone or tofogliflozin alone. Conclusion: Body weight reduction with tofogliflozin is mainly due to calorie loss with increased UGE. In addition, tofogliflozin also induces a metabolic shift from carbohydrate oxidation to fatty acid oxidation, which may lead to prevention of fat accumulation and inflammation in adipose tissue and liver. Tofogliflozin may have the potential to prevent obesity, hepatic steatosis and improve insulin resistance as well as hyperglycemia. PMID:25000147
McDonald, Samantha M.; Liu, Jihong; Wilcox, Sara; Lau, Erica Y.; Archer, Edward
2015-01-01
Objective This purpose of this review was to examine the relationship between exercise dose and reductions in weight gain during pregnancy in exercise interventions. Design and Methods Four electronic research databases (PubMed, Web of Science, CINAHL, and Academic Search Premiere) were used to identify exercise interventions conducted with pregnant women. Eligible articles must have satisfied the following criteria: inclusion of a control condition, exercise as a major intervention component, weight gain measured and reported for each experimental condition, description of exercise dose (frequency, intensity and duration), and utilized an adequate number of control conditions to assess independent effects of exercise on weight gain. Results The literature search identified 4837 articles, of these, 174 abstracts were screened and 21 intervention studies (18 exercise-only, 3 exercise/diet) were eligible for review. Only 38% of the interventions achieved statistically significant reductions in weight gain during pregnancy. Successful interventions possessed higher adherence and lower attrition rates and were predominantly conducted among normal weight populations. No clear patterns or consistencies of exercise dose and weight gain were evident. Conclusions Adherence and retention rates were strong contributors to the success of exercise interventions on weight gain during pregnancy. However, an exercise dose associated with reductions in weight gain was unquantifiable among these interventions. It is strongly suggested that future researchers investigate methods to increase adherence and compliance, especially among overweight and obese women, and utilize objective measurement tools to accurately evaluate exercise dose performed by the participants and the impact on both body composition and weight gain. PMID:25846125
Design optimization of aircraft landing gear assembly under dynamic loading
NASA Astrophysics Data System (ADS)
Wong, Jonathan Y. B.
As development cycles and prototyping iterations begin to decrease in the aerospace industry, it is important to develop and improve practical methodologies to meet all design metrics. This research presents an efficient methodology that applies high-fidelity multi-disciplinary design optimization techniques to commercial landing gear assemblies, for weight reduction, cost savings, and structural performance dynamic loading. Specifically, a slave link subassembly was selected as the candidate to explore the feasibility of this methodology. The design optimization process utilized in this research was sectioned into three main stages: setup, optimization, and redesign. The first stage involved the creation and characterization of the models used throughout this research. The slave link assembly was modelled with a simplified landing gear test, replicating the behavior of the physical system. Through extensive review of the literature and collaboration with Safran Landing Systems, dynamic and structural behavior for the system were characterized and defined mathematically. Once defined, the characterized behaviors for the slave link assembly were then used to conduct a Multi-Body Dynamic (MBD) analysis to determine the dynamic and structural response of the system. These responses were then utilized in a topology optimization through the use of the Equivalent Static Load Method (ESLM). The results of the optimization were interpreted and later used to generate improved designs in terms of weight, cost, and structural performance under dynamic loading in stage three. The optimized designs were then validated using the model created for the MBD analysis of the baseline design. The design generation process employed two different approaches for post-processing the topology results produced. The first approach implemented a close replication of the topology results, resulting in a design with an overall peak stress increase of 74%, weight savings of 67%, and no apparent cost savings due to complex features present in the design. The second design approach focused on realizing reciprocating benefits for cost and weight savings. As a result, this design was able to achieve an overall peak stress increase of 6%, weight and cost savings of 36%, and 60%, respectively.
Brachs, Maria; Wiegand, Susanna; Leupelt, Verena; Ernert, Andrea; Kintscher, Ulrich; Jumpertz von Schwarzenberg, Reiner; Decker, Anne-Marie; Bobbert, Thomas; Hübner, Norbert; Chen, Wei; Krude, Heiko; Spranger, Joachim; Mai, Knut
2016-06-01
In weight loss trials, a considerable inter-individual variability in reduction of fat mass and changes of insulin resistance is observed, even under standardized study conditions. The underlying mechanisms are not well understood. Given the metabolic properties of the atrial natriuretic peptide (ANP) system, we hypothesized that ANP signaling might be involved in this phenomenon by changes of ANP secretion or receptor balance. Therefore, we investigated the impact of systemic, adipose and myocellular ANP system on metabolic and anthropometric improvements during weight loss. We comprehensively investigated 143 subjects (31 male, 112 female) before and after a 3 month-standardized weight loss program. The time course of BMI, fat mass, insulin sensitivity, circulating mid-regional proANP (MR-proANP) levels as well as adipose and myocellular natriuretic receptor A (NPR-A) and C (NPR-C) mRNA expression were investigated. BMI decreased by -12.6±3.7%. This was accompanied by a remarkable decrease of adipose NPR-C expression (1005.0±488.4 vs. 556.7±465.6; p<0.001) as well as a tendency towards increased adipose NPR-A expression (4644.7±946.8 vs. 4877.6±869.8; p=0.051). Weight loss induced changes in NPR-C (ΔNPR-C) was linked to relative reduction of total fat mass (ΔFM) (r=0.281; p<0.05), reduction of BMI (r=0.277; p<0.01), and increase of free fatty acids (ΔFFA) (r=-0.258; p<0.05). Basal NPR-C expression and weight loss induced ΔNPR-C independently explained 22.7% of ΔFM. In addition, ΔMR-proANP was independently associated with improvement of insulin sensitivity (standardized ß=0.246, p<0.01). ANP receptor expression predicted the degree of weight loss induced fat mass reduction. Our comprehensive human data support that peripheral ANP signalling is involved in control of adipose tissue plasticity and function during weight loss. (Funded by the Deutsche Forschungsgemeinschaft (KFO281/2), the Berlin Institute of Health (BIH) and the German Centre for Cardiovascular Research (DZHK/BMBF); ClinicalTrials.gov number: NCT00850629). Copyright © 2016 Elsevier Inc. All rights reserved.
Concepts and analysis for precision segmented reflector and feed support structures
NASA Technical Reports Server (NTRS)
Miller, Richard K.; Thomson, Mark W.; Hedgepeth, John M.
1990-01-01
Several issues surrounding the design of a large (20-meter diameter) Precision Segmented Reflector are investigated. The concerns include development of a reflector support truss geometry that will permit deployment into the required doubly-curved shape without significant member strains. For deployable and erectable reflector support trusses, the reduction of structural redundancy was analyzed to achieve reduced weight and complexity for the designs. The stiffness and accuracy of such reduced member trusses, however, were found to be affected to a degree that is unexpected. The Precision Segmented Reflector designs were developed with performance requirements that represent the Reflector application. A novel deployable sunshade concept was developed, and a detailed parametric study of various feed support structural concepts was performed. The results of the detailed study reveal what may be the most desirable feed support structure geometry for Precision Segmented Reflector/Large Deployable Reflector applications.
Evaluation of Nutrition Imbalance in Chinese Chronic Kidney Disease Children.
Wang, Ke; Jiang, Yeping; Lai Master, Yuting; Shen, Ying
2018-06-22
Nutrition imbalance is common in chronic kidney disease (CKD) children. This study was to evaluate nutrition status of CKD children at different stages using bioimpedance analysis (BIA) compared with anthropometric measurements. Fifty-five CKD children at III, IV, V stages and 19 age and sex-matched healthy controls were recruited. Fat, protein and mineral compositions monitored by BIA were analyzed together with anthropometric measurements including height, weight and body mass index (BMI). Biochemical tests were checked in CKD children. Among the total CKD Children we recruited, 23.6%, 10.9% and 56.3% were underweight, overweight/obesity and stunting respectively. BIA showed that 52.7%, 70.9%, 14.5% and 40.0% of total CKD children had protein reduction, fat reduction, fat enhancement and mineral reduction respectively. The growth retardation and nutrition reduction became remarkable at stages IV and V. About 65% of nutrition reduction occurred in healthy-weight children. In the underweight and healthy-weight groups, fat reduction rates were higher than protein reduction rates. In overweight/obesity group, fat enhancement was most notable. Mineral reduction was less remarkable. The nutrition imbalance in CKD children assessed by BIA correlated well with anthropometric measurements and disease process, supporting BIA as a conjugated diagnosis tool. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
NASA Technical Reports Server (NTRS)
Lindsay, Howard A.; Motoyama, Stephen M.; Smith, Kent F.
1990-01-01
The development of composite-related technology applicable to armored crashworthy helicopter crewseats is discussed. The main objective was to achieve a significant weight reduction relative to the first-generation seats exemplified by the UH-60A and the AH-64A designs. This weight reduction was achieved while maintaining full compliance with the most recent version of the military crashworthy crewseat specification, MIL-S-58095A. The technology developed during this effort is intended to apply to the next generation of Army helicopters, such as LHX.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Nguyen, Ba Nghiep; Fifield, Leonard S.; Gandhi, Umesh N.
This project proposed to integrate, optimize and validate the fiber orientation and length distribution models previously developed and implemented in the Autodesk Simulation Moldflow Insight (ASMI) package for injection-molded long-carbon-fiber thermoplastic composites into a cohesive prediction capability. The current effort focused on rendering the developed models more robust and efficient for automotive industry part design to enable weight savings and cost reduction. The project goal has been achieved by optimizing the developed models, improving and integrating their implementations in ASMI, and validating them for a complex 3D LCF thermoplastic automotive part (Figure 1). Both PP and PA66 were used asmore » resin matrices. After validating ASMI predictions for fiber orientation and fiber length for this complex part against the corresponding measured data, in collaborations with Toyota and Magna PNNL developed a method using the predictive engineering tool to assess LCF/PA66 complex part design in terms of stiffness performance. Structural three-point bending analyses of the complex part and similar parts in steel were then performed for this purpose, and the team has then demonstrated the use of stiffness-based complex part design assessment to evaluate weight savings relative to the body system target (≥ 35%) set in Table 2 of DE-FOA-0000648 (AOI #1). In addition, starting from the part-to-part analysis, the PE tools enabled an estimated weight reduction for the vehicle body system using 50 wt% LCF/PA66 parts relative to the current steel system. Also, from this analysis an estimate of the manufacturing cost including the material cost for making the equivalent part in steel has been determined and compared to the costs for making the LCF/PA66 part to determine the cost per “saved” pound.« less
Investigating reduced bag weight as an effective risk mediator for mason tenders.
Davis, Kermit G; Kotowski, Susan E; Albers, James; Marras, William S
2010-10-01
Masonry workers face some of the highest physical demands in the construction industry where large bags of masonry material weighing 42.7 kg are commonly handled by mason tenders who mix the mortar, distribute mortar and bricks/blocks, and erect/dismantle scaffolding throughout the day. The objective of this study was to determine the effectiveness of using half-weight bags (21.4 kg) on reducing the biomechanical loading, physiological response, and perceived exertions. Ten male subjects performed asymmetric lifting tasks simulating unloading bags from a pallet. Muscle activity, trunk kinematics, heart rate, blood pressure and subjective rating data were collected. Spine loads were predicted from a well-validated EMG-assisted model. Bag weight, lift type, bag height at origin, and asymmetry at destination significantly impacted the spine loads. While there was a 50% reduction in bag weight, the peak loads for the half-weight bags were only 25% less than the more available full-weight bags (a reduction of about 320 N of shear and 1000 N of compression). Lifts allowing movement of the feet reduced the loads by about 22% in shear and 27% in compression compared to constrained postures. Interestingly, cumulative spine loads were greater for the lighter bags than the heavy bags ( approximately 40%). The subjective ratings of exertion and risk were significantly lower for the lighter bags. RELEVANCE TO INDUSTRY: The reduction in peak spine loading for the half-weight bags, particularly at the higher heights and when the feet were allowed to move could significantly reduce the injuries of masonry workers. However, there were trade-offs with cumulative loads that may minimize the reduced risk. Overall, given the limited amount of time lifting bags, the reduction of peak loads.
NASA Technical Reports Server (NTRS)
Mennell, R. C.
1973-01-01
Experimental aerodynamic investigations were conducted in a low speed wind tunnel on an 0.0405 scale representation of the 89A light weight Space Shuttle Orbiter to obtain pressure loads data in the presence of the ground for orbiter structural strength analysis. The model and the facility are described, and data reduction is outlined. Tables are included for data set/run number collation, data set/component collation, model component description, and pressure tap locations by series number. Tabulated force and pressure source data are presented.
Multi-material Preforming of Structural Composites
DOE Office of Scientific and Technical Information (OSTI.GOV)
Norris, Robert E.; Eberle, Cliff C.; Pastore, Christopher M.
2015-05-01
Fiber-reinforced composites offer significant weight reduction potential, with glass fiber composites already widely adopted. Carbon fiber composites deliver the greatest performance benefits, but their high cost has inhibited widespread adoption. This project demonstrates that hybrid carbon-glass solutions can realize most of the benefits of carbon fiber composites at much lower cost. ORNL and Owens Corning Reinforcements along with program participants at the ORISE collaborated to demonstrate methods for produce hybrid composites along with techniques to predict performance and economic tradeoffs. These predictions were then verified in testing coupons and more complex demonstration articles.
Kulshreshtha, Bindu; Gupta, Nandita; Ganie, Mohd Ashraf; Ammini, Ariachery C
2012-10-01
Metformin (an insulin sensitizer) and spironolactone (an antiandrogen) are both used for treatment of polycystic ovary syndrome. We analyzed the effect of 6 months of therapy with these drugs on body weight and glucose tolerance. This was a retrospective analysis of polycystic ovarian syndrome (PCOS) cases on treatment. There were 88 patients with PCOS-42 were on metformin 1 g daily and 46 were taking spironolactone 50-75 mg daily. 21 of 42 had abnormal glucose tolerance (AGT) in the metformin group and 13 of 46 had AGT in the spironolactone group. Patients on metformin reported a greater reduction in body weight, whereas there was no change in body weight with spironolactone therapy (67.6-63.7 versus 59.6-59.2 kg). There was a significant reduction in the 1 and 2 h glucose and insulin levels with metformin therapy in those with AGT. However, fasting glucose increased in those with normal glucose tolerance. There was no change in either body weight or insulin levels with spironolactone. But, there was a significant reduction in both the 0 and 2 h glucose with spironolactone also in those with AGT. Spironolactone and metformin had similar effect in reducing the glucose levels in PCOS patients with AGT. PCOS patients with normal glucose tolerance had higher fasting plasma glucose at the end of 6 months of metformin therapy inspite of weight reduction.
NASA Technical Reports Server (NTRS)
Levin, Alan D.; Hopkins, Edward J.
1961-01-01
An analysis was made to determine the reduction in payload for a 300 nautical mile orbit resulting from the addition of inert weight, representing recovery gear, to the first-stage booster of a three-stage rocket vehicle. The values of added inert weight investigated ranged from 0 to 18 percent of gross weight at lift off. The study also included the effects on the payload in orbit and the distance from the launch site at burnout and at impact caused by variation in the vertical rise time before the programmed tilt. The vertical rise times investigated ranged from 16-7 to 100 percent of booster burning time. For a vertical rise of 16.7 percent of booster burning time it was found that a 50-percent increase in the weight of the empty booster resulted in only a 10-percent reduction of the payload in orbit. For no added booster weight, increasing vertical rise time from 16-7 to 100 percent of booster burning time (so that the spent booster would impact in the launch area) reduced the payload by 37 percent. Increasing the vertical rise time from 16-7 to 50 percent of booster burning time resulted in about a 15-percent reduction in the impact distance, and for vertical rise times greater than 50-percent the impact distance decreased rapidly.
Iwahashi, Hiromi; Noguchi, Midori; Okauchi, Yukiyoshi; Morita, Sachiko; Imagawa, Akihisa; Shimomura, Iichiro
2015-09-01
Weight reduction improves glycemic control in obese men with glycated hemoglobin (HbA1c) of 5.6-6.4%, suggesting that it can prevent the development of diabetes in these patients. The aim of the present study was to quantify the amount of weight reduction necessary for minimization of diabetes risk in Japanese men with visceral fat accumulation. The study participants were 482 men with an estimated visceral fat area of ≥100 cm(2), HbA1c of 5.6-6.4%, fasting plasma glucose (FPG) of <126 mg/dL or casual plasma glucose <200 mg/dL. They were divided into two groups based on weight change at the end of the 3-year follow-up period (weight gain and weight loss groups). The weight loss group was classified into quartile subgroups (lowest group, 0 to <1.2%: second lowest group, ≥1.2 to <2.5%: second highest group, ≥2.5 to <4.3%: highest group, ≥4.3% weight loss). The development of diabetes at the end-point represented a rise in HbA1c to ≥6.5% or FPG ≥126 mg/dL, or casual plasma glucose ≥200 mg/dL. The cumulative incidence of diabetes at the end of the 3-year follow-up period was 16.2% in the weight gain group and 10.1% in the weight loss group (P not significant). The incidence of diabetes was significantly lower in the highest weight loss group (3.1%), but not in the second highest, the second lowest and the lowest weight loss groups (9.7, 10.1 and 18.3%), compared with the weight gain group. Minimization of the risk of diabetes in Japanese men with visceral fat accumulation requires a minimum of 4-5% weight loss in those with HbA1c of 5.6-6.4%.
Additive manufacturing of magnetic shielding and ultra-high vacuum flange for cold atom sensors.
Vovrosh, Jamie; Voulazeris, Georgios; Petrov, Plamen G; Zou, Ji; Gaber, Youssef; Benn, Laura; Woolger, David; Attallah, Moataz M; Boyer, Vincent; Bongs, Kai; Holynski, Michael
2018-01-31
Recent advances in the understanding and control of quantum technologies, such as those based on cold atoms, have resulted in devices with extraordinary metrological performance. To realise this potential outside of a lab environment the size, weight and power consumption need to be reduced. Here we demonstrate the use of laser powder bed fusion, an additive manufacturing technique, as a production technique relevant to the manufacture of quantum sensors. As a demonstration we have constructed two key components using additive manufacturing, namely magnetic shielding and vacuum chambers. The initial prototypes for magnetic shields show shielding factors within a factor of 3 of conventional approaches. The vacuum demonstrator device shows that 3D-printed titanium structures are suitable for use as vacuum chambers, with the test system reaching base pressures of 5 ± 0.5 × 10 -10 mbar. These demonstrations show considerable promise for the use of additive manufacturing for cold atom based quantum technologies, in future enabling improved integrated structures, allowing for the reduction in size, weight and assembly complexity.
Composite structural armor for combat vehicle applications
NASA Technical Reports Server (NTRS)
Haskell, William E., III; Alesi, A. L.; Parsons, G. R.
1990-01-01
Several projects that have demonstrated the advantages of using thick composite armor technology for structural applications in armored combat vehicles are discussed. The first involved composite cargo doors for the Marine Corps LVTP-7 amphibious landing vehicle. Another was a demonstration composite turret that offered a weight reduction of 15.5 percent. The advantages of this composite armor compared to metallic armors used for combat vehicle hull and turret applications are reduced weight at equal ballistic protection; reduced back armor spall; excellent corrosion resistance; reduced production costs by parts consolidation; and inherent thermal and acoustic insulative properties. Based on the encouraging results of these past programs, the Demonstration Composite Hull Program was started in September 1986. To demonstrate this composite armor technology, the Army's newest infantry fighting vehicle, the Bradley Fighting Vehicle (BFV), was selected as a model. A composite infantry fighting vehicle, designated the CIFV for this program, has been designed and fabricated and is currently undergoing a 6000 mile field endurance test. The CIFV demonstration vehicle uses the BFV engine, transmission, suspension, track and other equipment.
Relationship between body mass index and hippocampal glutamate/glutamine in bipolar disorder.
Bond, David J; da Silveira, Leonardo Evangelista; MacMillan, Erin L; Torres, Ivan J; Lang, Donna J; Su, Wayne; Honer, William G; Lam, Raymond W; Yatham, Lakshmi N
2016-02-01
We previously reported that patients with early-stage bipolar disorder, but not healthy comparison controls, had body mass index (BMI)-related volume reductions in limbic brain areas, suggesting that the structural brain changes characteristic of bipolar disorder were more pronounced with increased weight. To determine whether the most consistently reported neurochemical abnormality in bipolar disorder, increased glutamate/glutamine (Glx), was also more prominent with higher BMI. We used single-voxel proton magnetic resonance spectroscopy to measure hippocampal Glx in 51 patients with first-episode mania (mean BMI = 24.1) and 28 healthy controls (mean BMI = 23.3). In patients, but not healthy controls, linear regression demonstrated that higher BMI predicted greater Glx. Factorial ANCOVA showed a significant BMI × diagnosis interaction, confirming a distinct effect of weight on Glx in patients. Together with our volumetric studies, these results suggest that higher BMI is associated with more pronounced structural and neurochemical limbic brain changes in bipolar disorder, even in early-stage patients with low obesity rates. © The Royal College of Psychiatrists 2016.
Bio-reducible polycations from ring-opening polymerization as potential gene delivery vehicles.
Yu, Qing-Ying; Liu, Yan-Hong; Huang, Zheng; Zhang, Ji; Luan, Chao-Ran; Zhang, Qin-Fang; Yu, Xiao-Qi
2016-07-06
Synthetic polycations show great potential for the construction of ideal non-viral gene delivery systems. Several cationic polymers were synthesized by the epoxide ring-opening polymerization between diepoxide and various polyamines. Disulfide bonds were introduced to afford the polymers bio-reducibility, while the oxygen-rich structure might enhance the serum tolerance and biocompatibility. The polycations have much lower molecular weights than PEI 25 kDa, but still could well bind and condense DNA into nano-sized particles. DNA could be released from the polyplexes by addition of reductive DTT. Compared to PEI, the polycations have less cytotoxicity possibly due to their lower molecular weights and oxygen-rich structure. More significantly, these materials exhibit excellent serum tolerance than PEI, and up to 6 times higher transfection efficiency than PEI could be obtained in the presence of serum. The transfection mediated by was seldom affected even at a high concentration of serum. Much lower protein adsorption of polycations than PEI was proved by bovine serum albumin adsorption experiments. Flow cytometry also demonstrates their good serum resistance ability.
Salman, Mahmoud; Yassin, Dany-Jan; Shoukfeh, Huda; Nettleship, Joanne Elisabeth; Yassin, Aksam
2017-03-01
We and others have previously shown that testosterone replacement therapy (TRT) results in sustained weight loss in the majority of middle-aged hypogonadal men. Previously, however, a small proportion failed to lose at least 5% of their baseline weight. The reason for this is not yet understood. In the present study, we sought to identify early indicators that may predict successful long-term weight loss, defined as a reduction of at least 5% of total body weight relative to baseline weight (T0), in men with hypogonadism undergoing TRT. Eight parameters measured were assessed as potential predictors of sustained weight loss: loss of 3% or more of baseline weight after 1 year of TU treatment, severe hypogonadism, BMI, waist circumference, International Prostate Symptom Score (IPSS), glycated hemoglobin (HbA 1C ), age and use of vardenafil. Among the eight measured parameters, three factors were significantly associated with sustained weight loss over the entire period of TU treatment: (1) a loss of 3% of the baseline body weight after 1 year of TRT; (2) baseline BMI over 30; and (3) a waist circumference >102 cm. Age was not a predictor of weight loss.
Busso, Dolores; Mascareño, Lilian; Salas, Francisca; Berkowitz, Loni; Santander, Nicolás; Quiroz, Alonso; Amigo, Ludwig; Valdés, Gloria; Rigotti, Attilio
2014-01-01
The susceptibility to develop atherosclerosis is increased by intrauterine growth restriction and prenatal exposure to maternal hypercholesterolemia. Here, we studied whether mouse gestational hypercholesterolemia and atherosclerosis affected fetal development and growth at different stages of gestation. Female LDLR KO mice fed a proatherogenic, high cholesterol (HC) diet for 3 weeks before conception and during pregnancy exhibited a significant increase in non-HDL cholesterol and developed atherosclerosis. At embryonic days 12.5 (E12.5), E15.5, and E18.5, maternal gestational hypercholesterolemia and atherosclerosis were associated to a 22–24% reduction in male and female fetal weight without alterations in fetal number/litter or morphology nor placental weight or structure. Feeding the HC diet exclusively at the periconceptional period did not alter fetal growth, suggesting that maternal hypercholesterolemia affected fetal weight only after implantation. Vitamin E supplementation (1,000 UI of α-tocopherol/kg) of HC-fed females did not change the mean weight of E18.5 fetuses but reduced the percentage of fetuses exhibiting body weights below the 10th percentile of weight (HC: 90% vs. HC/VitE: 68%). In conclusion, our results showed that maternal gestational hypercholesterolemia and atherosclerosis in mice were associated to early onset fetal growth restriction and that dietary vitamin E supplementation had a beneficial impact on this condition. PMID:25295255
Chung, Louisa Ming Yan; Fong, Shirley Siu Ming
2015-01-01
Weight reduction that corresponds with lifestyle modification is difficult to foster. The theory of planned behaviour has been actively cited in explaining health-related behaviour. This review evaluated the application of the theory of planned behaviour to weight-loss behaviour. Among the three reviewed papers, cross-sectional survey designs and subjective outcome measurements were commonly applied. All of the studies recruited obese female adults as participants, limiting the generalisability of the studies' findings. The theory of planned behaviour can be effectively applied in weight-reduction programmes targeting female obese patients. This review confirmed critiques citing the limitations of experimental studies, the subjective measurement of behaviour and short follow-up periods.
NASA Technical Reports Server (NTRS)
Braslow, A. L.; Whitehead, A. H., Jr.
1973-01-01
The anticipated growth of air transportation is in danger of being constrained by increased prices and insecure sources of petroleum-based fuel. Fuel-conservation possibilities attainable through the application of advances in aeronautical technology to aircraft design are identified with the intent of stimulating NASA R and T and systems-study activities in the various disciplinary areas. The material includes drag reduction; weight reduction; increased efficiency of main and auxiliary power systems; unconventional air transport of cargo; and operational changes.
Fatigue Behavior of AM60B Subjected to Variable Amplitude Loading
NASA Astrophysics Data System (ADS)
Kang, H.; Kari, K.; Khosrovaneh, A. K.; Nayaki, R.; Su, X.; Zhang, L.; Lee, Y.-L.
Magnesium alloys are considered as an alternative material to reduce vehicle weight due to their weight which are 33% lighter than aluminum alloys. There has been a significant expansion in the applications of magnesium alloys in automotives components in an effort to improve fuel efficiency through vehicle mass reduction. In this project, a simple front shock tower of passenger vehicle is constructed with various magnesium alloys. To predict the fatigue behavior of the structure, fatigue properties of the magnesium alloy (AM60B) were determined from strain controlled fatigue tests. Notched specimens were also tested with three different variable amplitude loading profiles obtained from the shock tower of the similar size of vehicle. The test results were compared with various fatigue prediction results. The effect of mean stress and fatigue prediction method were discussed.
Weight management using the internet: A randomized controlled trial
USDA-ARS?s Scientific Manuscript database
Most weight-loss research targets obese individuals who desire large weight reductions. However, evaluation of weight-gain prevention in overweight individuals is also critical as most Americans become obese as a result of a gradual gain of 1-2 pounds per year over many years. This study evaluated t...
Cabrera, Jorge L; Wilks, Edward G; Symons, Jenna E; Blankson, Kwabena L; Cole, Renee E
2012-03-01
Assess body mass index (BMI) reduction through a multidisciplinary intervention with sibutramine in adolescents of military parents and examine characteristics and behavioral traits as predictors of successful weight loss. A prospective study where participants received sibutramine daily for 6 months. Adolescents ages 12 to 18 with BMI-for-age and sex greater than 95 percentile and good health were enrolled. Outcome variables are BMI, biochemical indices, and clinical measurements. Predictor variables are participant demographics, family history, lifestyle changes, and behavioral traits assessed with behavioral assessment for children. One hundred participants were recruited with 81% completion. In those participants who completed the 6-month intervention, a mean participant BMI reduction of 3.1 kg/m2 (-9.3%) (p < 0.001; 95% CI: -10.5% to -7.9%) was obtained with 79% successfully meeting the weight loss goal. Sibutramine dose was increased from 10 to 15 mg at 3 months for participant with <2.5% BMI reduction from baseline. Sibutramine dose at 3 months (p < 0.001) and participants perception of relationship with parents (p = 0.05) were statistically significant predictors of successful weight loss (> or =10% reduction in BMI). Sibutramine was effective at promoting minimum beneficial BMI reduction of 5% in adolescents with service-connected parents; however, increasing dosage at 3 months did not improve the likelihood of being successful.
Fennig, Silvana; Brunstein Klomek, Anat; Shahar, Ben; Sarel-Michnik, Zohar; Hadas, Arie
2017-06-01
Examine changes in core perceptions and thoughts during the weight restoration phase of inpatient treatment for adolescents with anorexia nervosa. Forty-four adolescents with anorexia nervosa consecutively admitted (2009-2012) to an inpatient paediatric-psychiatric unit specializing in eating disorders. The programme consisted of a complete inpatient intervention combining weight restoration by structured supervised meals with individual and group cognitive-behavioural therapy, parental training/family intervention and educational activities, followed by a half-way day-treatment weight-stabilizing phase and progressive reintroduction to the community. The study focused on changes from hospital admission to discharge in patients' responses to self-report questionnaires on eating disorder symptoms, depression, anxiety and suicidal ideation. No significant changes in core anorexic thoughts and perceptions as Body dissatisfaction, Drive for thinness, Weight concern and Shape concern were noted. However, a reduction in the general severity of eating disorder symptoms (including Restraint and Eating concern) was observed, mainly related to the treatment structure. Levels of depression significantly decreased but remained within pathological range. We also found a concerning increase in suicidal ideation not correlated with a concomitant increase in depressive symptomatology. Inpatient treatment of anorexia nervosa in adolescents does not significantly modify core anorexic thoughts and perceptions. This may explain the high relapse rates. Changes in core beliefs may be crucial for recovery and prevention of relapse in anorexia nervosa at this critical age. This study may have clinical implications for the development of better treatment strategies to target the gap between disturbed thoughts and distorted perceptions - the core aspects of anorexia nervosa and physical recovery during and after the weight restoration phase. © 2015 Wiley Publishing Asia Pty Ltd.
Estrogen or raloxifene during postmenopausal weight loss: adiposity and cardiometabolic outcomes.
Van Pelt, R E; Gozansky, W S; Wolfe, P; Kittelson, J M; Jankowski, C M; Schwartz, R S; Kohrt, W M
2014-04-01
Estrogen-based hormone therapy (HT) attenuates abdominal fat gain after menopause, but whether HT improves abdominal fat loss during weight loss is unknown. It was hypothesized that HT or a selective estrogen receptor modulator (raloxifene) would augment reductions in abdominal visceral fat during weight loss when compared to placebo, potentially increasing improvements in glucose tolerance and lipid profile. Healthy postmenopausal women (n = 119; age 50-70 yr) underwent a 6-month weight-loss (primarily exercise) intervention with randomization to raloxifene (60 mg/d), HT (conjugated estrogens, 0.625 mg/d), or placebo. Outcomes were change in total and abdominal (visceral and subcutaneous) fat mass, lipid profile, and fasting and post-challenge glucose and insulin. Neither HT nor raloxifene augmented loss of total or abdominal fat mass during exercise-induced weight loss when compared with placebo. Weight loss-induced improvements in risk factors were similar among the three groups, except for a greater reduction in fasted glucose in the HT group (difference in change [95%CI] from placebo; -0.40 [-0.76, -0.05]) and greater reductions in LDL (-0.36 [-0.63, -0.09]) and increases in HDL (0.15 [0.07, 0.24]) in both treatment groups. Postmenopausal HT and raloxifene did not increase abdominal fat loss during weight loss, but did improve some cardiometabolic outcomes. Copyright © 2013 The Obesity Society.
Low Cost Carbon Fibre: Applications, Performance and Cost Models - Chapter 17
DOE Office of Scientific and Technical Information (OSTI.GOV)
Warren, Charles David; Wheatley, Dr. Alan; Das, Sujit
2014-01-01
Weight saving in automotive applications has a major bearing on fuel economy. It is generally accepted that, typically, a 10% weight reduction in an automobile will lead to a 6-8% improvement in fuel economy. In this respect, carbon fibre composites are extremely attractive in their ability to provide superlative mechanical performance per unit weight. That is why they are specified for high-end uses such as Formula 1 racing cars and the latest aircraft (e.g. Boeing 787, Airbus A350 and A380), where they comprise over 50% by weight of the structure However, carbon fibres are expensive and this renders their compositesmore » similarly expensive. Research has been carried out at Oak Ridge National Laboratories (ORNL), Tennessee, USA for over a decade with the aim of reducing the cost of carbon fibre such that it becomes a cost-effective option for the automotive industry. Aspects of this research relating to the development of low cost carbon fibre have been reported in Chapter 3 of this publication. In this chapter, the practical industrial applications of low-cost carbon fibre are presented, together with considerations of the performance and cost models which underpin the work.« less
National survey on management of weight reduction in PCOS women in the United Kingdom.
Sharma, Aarti; Walker, Dawn-Marie; Atiomo, William
2010-10-01
To identify the most commonly used methods for weight reduction in women with polycystic ovarian syndrome (PCOS) utilized by obstetricians and gynaecologists in the United Kingdom (UK). Permission was sought from the Royal College of Obstetricians and Gynaecologists (RCOG) to conduct an electronic survey of all consultants practising in the UK. The questionnaire was anonymous and an electronic link was sent via email to the 1140 consultants whose details were provided by the RCOG. A 27-item questionnaire was developed. The variables evaluated were first-line methods of weight reduction used, proportion of women with PCOS seen that were obese, whether the patients had tried other weight reduction methods before seeking help, the optimal dietary advice and optimal composition, the optimal duration and frequency of exercise suggested, BMI used for suggesting weight loss, percentage of women in whom weight loss worked, length of time allowed prior to suggesting another method, methods considered most effective by patients, use of metformin for weight loss, criteria used for prescribing metformin, first-line anti-obesity drugs preferred if any, second- and third-line methods used, referral to other specialists and criteria for referral for bariatric surgery. Responses were categorical and are reported as proportions. One hundred and seven (9.4%) consultants responded to the questionnaire. One hundred and four (97%) provided advice on diet and 101 (94%) advice on exercise as their first-line strategy for weight management. Fifty-one (47.7%) stated that they provided specific information on an optimal dietary intake, 53 (49.9%) on the optimal dietary composition and 61 (57%) on the optimal duration and frequency of exercise per week. The commonest second-line methods used were anti-obesity drugs and metformin and the most popular third-line management options were anti-obesity drugs and bariatric surgery. The results suggest that the information provided to women with PCOS on weight management is variable, and highlight the need for specific guidelines and further research on weight management in women with this condition. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.
Cumming, H; Herbert, N A
2016-01-01
Turbidity as a result of increased suspended sediments in coastal waters is an environmental stress of worldwide concern. Recent research on fish suggests that detrimental changes to gill structure can occur in turbid waters, with speculation that these alterations diminish fitness variables, such as growth and development, by negatively impacting the O 2 uptake capacity (respiration) of fish. Specifically to address this unknown, the impact of turbid water on the gill structure, somatic growth rate and O 2 uptake rates of a juvenile sparid species ( Pagrus auratus ) was addressed following exposure to five different turbidity treatments (<10, 20, 40, 60 or 80 nephelometric turbidity units) for 30 days. Significant gill structural change was apparent with a progressive increase in turbidity and was quantified as a reduction in lamellar density, as well as an increase in basal hyperplasia, epithelial lifting and increased oxygen diffusion distance across the lamellae. The weight of control fish did not change throughout the experiment, but all fish exposed to turbid waters lost weight, and weight loss increased with nephelometric turbidity units, confirming that long-term turbidity exposure is detrimental to growth productivity. The growth of fish could be impacted in a variety of ways, but the specific hypothesis that structural alteration of the gills impairs O 2 uptake across the gills and limits growth fitness was not supported because there was no measurable difference in the standard metabolic rate, maximal metabolic rate, aerobic metabolic scope or critical oxygen saturation limit of fish measured in clear water after 30 days of exposure. Although impaired O 2 uptake as a result of structurally adjusted gills is unlikely to be the cause of poor fish growth, the exact mechanism by which growth productivity is affected in turbid conditions remains unclear and warrants further investigation.
Cumming, H.; Herbert, N. A.
2016-01-01
Turbidity as a result of increased suspended sediments in coastal waters is an environmental stress of worldwide concern. Recent research on fish suggests that detrimental changes to gill structure can occur in turbid waters, with speculation that these alterations diminish fitness variables, such as growth and development, by negatively impacting the O2 uptake capacity (respiration) of fish. Specifically to address this unknown, the impact of turbid water on the gill structure, somatic growth rate and O2 uptake rates of a juvenile sparid species (Pagrus auratus) was addressed following exposure to five different turbidity treatments (<10, 20, 40, 60 or 80 nephelometric turbidity units) for 30 days. Significant gill structural change was apparent with a progressive increase in turbidity and was quantified as a reduction in lamellar density, as well as an increase in basal hyperplasia, epithelial lifting and increased oxygen diffusion distance across the lamellae. The weight of control fish did not change throughout the experiment, but all fish exposed to turbid waters lost weight, and weight loss increased with nephelometric turbidity units, confirming that long-term turbidity exposure is detrimental to growth productivity. The growth of fish could be impacted in a variety of ways, but the specific hypothesis that structural alteration of the gills impairs O2 uptake across the gills and limits growth fitness was not supported because there was no measurable difference in the standard metabolic rate, maximal metabolic rate, aerobic metabolic scope or critical oxygen saturation limit of fish measured in clear water after 30 days of exposure. Although impaired O2 uptake as a result of structurally adjusted gills is unlikely to be the cause of poor fish growth, the exact mechanism by which growth productivity is affected in turbid conditions remains unclear and warrants further investigation. PMID:27766155
Central pedicled breast reduction technique in male patients after massive weight loss.
Stoff, Alexander; Velasco-Laguardia, Fernando J; Richter, Dirk F
2012-03-01
Male patients after massive weight loss often suffer from redundant skin and soft tissue in the anterior and lateral chest region, causing various deformities of pseudogynecomastia. Techniques with free or pedicled nipple-areola complex (NAC) transposition are widely accepted. The authors present their approach to male breast reduction with preservation of the NAC on a central dermoglandular pedicle and a wide elliptical tissue excision of breast and lateral thorax tissue in combination with liposuction. Male breast reduction was performed on patients after moderate to massive weight loss due to diet or bariatric procedures. Former procedures included free nipple-areola grafts or inferior pedicled techniques for NAC preservation. As a modification, we performed a central pedicled breast reduction on nine male patients with excessive liposuction of the pedicle and a horizontal elliptical skin removal, allowing for sufficient tissue removal at the lateral thorax. From October 2010 until June 2011, nine male patients had central pedicled breast reconstructions after massive weight loss. Mean age was 29.1 years, mean preoperative body mass index was 29.2, and mean preoperative weight loss was 63.9 kg. The chest wall improvement was rated "very good" by eight patients. No major complications occurred in all nine patients. Male chest deformities after massive weight loss can be dealt by several approaches. The optimal scar positioning and the preservation of NAC may be the most challenging aspects of these procedures. Therefore, the preservation of the NAC on a central dermoglandular pedicle with a horizontal submammary scar course may optimize the esthetic outcome.
Estimating rare events in biochemical systems using conditional sampling.
Sundar, V S
2017-01-28
The paper focuses on development of variance reduction strategies to estimate rare events in biochemical systems. Obtaining this probability using brute force Monte Carlo simulations in conjunction with the stochastic simulation algorithm (Gillespie's method) is computationally prohibitive. To circumvent this, important sampling tools such as the weighted stochastic simulation algorithm and the doubly weighted stochastic simulation algorithm have been proposed. However, these strategies require an additional step of determining the important region to sample from, which is not straightforward for most of the problems. In this paper, we apply the subset simulation method, developed as a variance reduction tool in the context of structural engineering, to the problem of rare event estimation in biochemical systems. The main idea is that the rare event probability is expressed as a product of more frequent conditional probabilities. These conditional probabilities are estimated with high accuracy using Monte Carlo simulations, specifically the Markov chain Monte Carlo method with the modified Metropolis-Hastings algorithm. Generating sample realizations of the state vector using the stochastic simulation algorithm is viewed as mapping the discrete-state continuous-time random process to the standard normal random variable vector. This viewpoint opens up the possibility of applying more sophisticated and efficient sampling schemes developed elsewhere to problems in stochastic chemical kinetics. The results obtained using the subset simulation method are compared with existing variance reduction strategies for a few benchmark problems, and a satisfactory improvement in computational time is demonstrated.
Wing, R R; Epstein, L H; Nowalk, M P; Scott, N; Koeske, R; Hagg, S
1986-11-01
Self-monitoring of blood glucose levels is currently being recommended for obese patients with type II diabetes to improve weight loss and glycemic control. To determine whether self-monitoring of blood glucose levels improves dietary compliance in these patients, 50 obese patients with type II diabetes were randomly assigned either to a standard behavioral weight control program or to a weight control program that included self-monitoring of blood glucose levels and focused on the weight-blood glucose relationship. Both groups lost significant amounts of weight and maintained their losses for at least one year; reductions in medication could be made for 70 percent of patients. These data suggest that the behavioral weight control used in this study may be of benefit to patients with type II diabetes. However, there was no evidence that the addition of self-monitoring of blood glucose levels to the treatment program improved the outcome in terms of weight loss, reduction in medication, dietary compliance, or mood state.
Testosterone Dose Dependently Prevents Bone and Muscle Loss in Rodents after Spinal Cord Injury
Conover, Christine F.; Beggs, Luke A.; Beck, Darren T.; Otzel, Dana M.; Balaez, Alexander; Combs, Sarah M.; Miller, Julie R.; Ye, Fan; Aguirre, J. Ignacio; Neuville, Kathleen G.; Williams, Alyssa A.; Conrad, Bryan P.; Gregory, Chris M.; Wronski, Thomas J.; Bose, Prodip K.; Borst, Stephen E.
2014-01-01
Abstract Androgen administration protects against musculoskeletal deficits in models of sex-steroid deficiency and injury/disuse. It remains unknown, however, whether testosterone prevents bone loss accompanying spinal cord injury (SCI), a condition that results in a near universal occurrence of osteoporosis. Our primary purpose was to determine whether testosterone-enanthate (TE) attenuates hindlimb bone loss in a rodent moderate/severe contusion SCI model. Forty (n=10/group), 14 week old male Sprague-Dawley rats were randomized to receive: (1) Sham surgery (T9 laminectomy), (2) moderate/severe (250 kdyne) SCI, (3) SCI+Low-dose TE (2.0 mg/week), or (4) SCI+High-dose TE (7.0 mg/week). Twenty-one days post-injury, SCI animals exhibited a 77–85% reduction in hindlimb cancellous bone volume at the distal femur (measured via μCT) and proximal tibia (measured via histomorphometry), characterized by a >70% reduction in trabecular number, 13–27% reduction in trabecular thickness, and increased trabecular separation. A 57% reduction in cancellous volumetric bone mineral density (vBMD) at the distal femur and a 20% reduction in vBMD at the femoral neck were also observed. TE dose dependently prevented hindlimb bone loss after SCI, with high-dose TE fully preserving cancellous bone structural characteristics and vBMD at all skeletal sites examined. Animals receiving SCI also exhibited a 35% reduction in hindlimb weight bearing (triceps surae) muscle mass and a 22% reduction in sublesional non-weight bearing (levator ani/bulbocavernosus [LABC]) muscle mass, and reduced prostate mass. Both TE doses fully preserved LABC mass, while only high-dose TE ameliorated hindlimb muscle losses. TE also dose dependently increased prostate mass. Our findings provide the first evidence indicating that high-dose TE fully prevents hindlimb cancellous bone loss and concomitantly ameliorates muscle loss after SCI, while low-dose TE produces much less profound musculoskeletal benefit. Testosterone-induced prostate enlargement, however, represents a potential barrier to the clinical implementation of high-dose TE as a means of preserving musculoskeletal tissue after SCI. PMID:24378197
Clark, Caron A. C.; Fang, Hua; Espy, Kimberly Andrews; Filipek, Pauline A.; Juranek, Jenifer; Bangert, Barbara; Hack, Maureen; Taylor, H. Gerry
2013-01-01
Objective Children with very low birth weight (VLBW; <1500g) are at risk for academic underachievement, although less is known regarding the developmental course of these difficulties or their neural basis. This study examined whether cerebral tissue reductions related to VLBW are associated with poor patterns of growth in core academic skills. Method Children born <750 g, 750–1499 g or >2500 g completed measures of calculation, mathematical problem solving and word decoding at several time points spanning middle childhood and adolescence. Espy, Fang, Charak, Minich and Taylor (2009) used growth mixture modeling to identify two distinct growth trajectories (growth clusters) for each academic domain: an average achievement trajectory and a persistently low achievement trajectory. In this study, 97 of the same participants underwent MRI in late adolescence. MRI measures of cerebral tissue volume were used to predict the probability of low growth cluster membership for each domain. Results After adjusting for whole brain volume, each 1cm3 reduction in caudate volume was associated with a 1.7 – 2.1 fold increase in the odds of low cluster membership for each academic domain. Each 1mm2 decrease in corpus callosum surface area increased these odds approximately 1.02 fold. Reductions in cerebellar white matter volume were associated specifically with low calculation and decoding growth while reduced cerebral white matter volume was associated with low calculation growth. Findings were similar when analyses were confined to the VLBW groups. Conclusions Volumetric reductions in neural regions involved in connectivity, executive attention and motor control may help to explain heterogeneous academic growth trajectories amongst children with VLBW. PMID:23688218
The effect of trichlorfon and methylazoxymethanol on the development of guinea pig cerebellum.
Mehl, Anna; Schanke, Tore M; Torvik, Ansgar; Fonnum, Frode
2007-03-01
The pesticide trichlorfon (125 mg/kg on days 42-44 in gestation) gives hypoplasia of the brain of the offspring without any significant reduction in their body weights. The hypoplasia may be caused by trichlorfon itself or by its metabolite dichlorvos. This period of development coincides with the growth spurt period of guinea pig brain. The largest changes occurred in the cerebellum. Electron microscopic examination of the cerebellar cortex showed increased apoptotic death of cells in the granule cell layer after trichlorfon treatment. A reduction in thickness of the external germinal layer of the cerebellar cortex and an elevated amount of pyknotic and karyorrhexic cells in the granule cell layer was found. There was a significant reduction in choline esterase, choline acetyltransferase and glutamate decarboxylase activities in the cerebellum. Methylazoxymethanol (15 mg/kg body weight, day 43) was examined for comparison and caused similar hypoplasia of the guinea pig cerebellum, but did also induce a reduction in body weight. Trichloroethanol, the main metabolite of trichlorfon, did not give brain hypoplasia.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mehl, Anna; Schanke, Tore M.; Torvik, Ansgar
The pesticide trichlorfon (125 mg/kg on days 42-44 in gestation) gives hypoplasia of Brain of the offspring without any significant reduction in their body weights. The hypoplasia may be caused by trichlorfon itself or by its metabolite dichlorvos. This period of development coincides with the growth spurt period of guinea pig brain. The largest changes occurred in the cerebellum. Electron microscopic examination of the cerebellar cortex showed increased apoptotic death of cells in the granule cell layer after trichlorfon treatment. A reduction in thickness of the external germinal layer of the cerebellar cortex and an elevated amount of pyknotic andmore » karyorrhexic cells in the granule cell layer was found. There was a significant reduction in choline esterase, choline acetyltransferase and glutamate decarboxylase activities in the cerebellum. Methylazoxymethanol (15 mg/kg body weight, day 43) was examined for comparison and caused similar hypoplasia of the guinea pig cerebellum, but did also induce a reduction in body weight. Trichloroethanol, the main metabolite of trichlorfon, did not give brain hypoplasia.« less
NASA Astrophysics Data System (ADS)
Senge, S.; Brachmann, J.; Hirt, G.; Bührig-Polaczek, A.
2017-10-01
Lightweight design is a major driving force of innovation, especially in the automotive industry. Using hybrid components made of two or more different materials is one approach to reduce the vehicles weight and decrease fuel consumption. As a possible way to increase the stiffness of multi-material components, this paper presents a process chain to produce such components made of steel sheets and high-pressure die cast aluminium. Prior to the casting sequence the steel sheets are structured in a modified rolling process which enables continuous interlocking with the aluminium. Two structures manufactured by this rolling process are tested. The first one is a channel like structure and the second one is a channel like structure with undercuts. These undercuts enable the formation of small anchors when the molten aluminium fills them. The correlation between thickness reduction during rolling and the shape of the resulting structure was evaluated for both structures. It can be stated that channels with a depth of up to 0.5 mm and a width of 1 mm could be created. Undercuts with different size depending on the thickness reduction could be realised. Subsequent aluminium high-pressure die casting experiments were performed to determine if the surface structure can be filled gap-free with molten aluminium during the casting sequence and if a gap-free connection can be achieved after contraction of the aluminium. The casting experiments showed that both structures could be filled during the high-pressure die casting. The channel like structure results in a gap between steel and aluminium after contraction of the cast metal whereas the structure with undercuts leads to a good interlocking resulting in a gap-free connection.
Process and assembly plans for low cost commercial fuselage structure
NASA Technical Reports Server (NTRS)
Willden, Kurtis; Metschan, Stephen; Starkey, Val
1991-01-01
Cost and weight reduction for a composite structure is a result of selecting design concepts that can be built using efficient low cost manufacturing and assembly processes. Since design and manufacturing are inherently cost dependent, concurrent engineering in the form of a Design-Build Team (DBT) is essential for low cost designs. Detailed cost analysis from DBT designs and hardware verification must be performed to identify the cost drivers and relationships between design and manufacturing processes. Results from the global evaluation are used to quantitatively rank design, identify cost centers for higher ranking design concepts, define and prioritize a list of technical/economic issues and barriers, and identify parameters that control concept response. These results are then used for final design optimization.
Sabadini, Edvaldo; Francisco, Kelly R; Bouteiller, Laurent
2010-02-02
The hydrodynamic drag reduction phenomenon, also termed the Toms effect, is an unusual case involving macromolecules in solution in which the resistance to flow is reduced comparatively to that of the pure solvent. Although the effect is relatively well characterized, it is still unclear from the molecular viewpoint. The presence of some amount of a polymer with high molecular weight can produce large levels of drag reduction in turbulent flow as a result of the interactions of the long structures with the small vortices developed during the flow. For this reason, the effect is very attractive in the pumping process because a significant amount of energy can be saved. In aqueous systems, giant micelles can be spontaneously formed, driven by the hydrophobic effect, and are effective drag reducers. Giant micelles are interesting in promoting drag reduction because the noncovalent and reversible aggregation of the surfactant molecules avoids mechanical degradation, which typically occurs with classical polymers, due to irreversible scission of the backbone. In this letter, we present the first hydrodynamic drag reducer for hydrocarbons based on a self-assembled polymer formed from the reversible aggregation of bis-urea monomers. This system forms two competitive polymeric structures--the tube (T) and the filament (F) forms--which are in equilibrium with each other. Our rheology results in octane and toluene are fully consistent with calorimetry data and show that only the longest form, T, is able to promote the drag reduction effect.
NASA Astrophysics Data System (ADS)
Madhavi, M.; Venkat, R.
2014-01-01
Fiber reinforced polymer composite materials with their higher specific strength, moduli and tailorability characteristics will result in reduction of weight of the structure. The composite pressure vessels with integrated end domes develop hoop stresses that are twice longitudinal stresses and when isotropic materials like metals are used for development of the hardware and the material is not fully utilized in the longitudinal/meridional direction resulting in over weight components. The determination of a proper winding angles and thickness is very important to decrease manufacturing difficulties and to increase structural efficiency. In the present study a methodology is developed to understand structural characteristics of filament wound pressure vessels with integrated end domes. Progressive ply wise failure analysis of composite pressure vessel with geodesic end domes is carried out to determine matrix crack failure, burst pressure values at various positions of the shell. A three dimensional finite element analysis is computed to predict the deformations and stresses in the composite pressure vessel. The proposed method could save the time to design filament wound structures, to check whether the ply design is safe for the given input conditions and also can be adapted to non-geodesic structures. The results can be utilized to understand structural characteristics of filament wound pressure vessels with integrated end domes. This approach can be adopted for various applications like solid rocket motor casings, automobile fuel storage tanks and chemical storage tanks. Based on the predictions a composite pressure vessel is designed and developed. Hydraulic test is performed on the composite pressure vessel till the burst pressure.
Target weight achievement and ultrafiltration rate thresholds: potential patient implications.
Flythe, Jennifer E; Assimon, Magdalene M; Overman, Robert A
2017-06-02
Higher ultrafiltration (UF) rates and extracellular hypo- and hypervolemia are associated with adverse outcomes among maintenance hemodialysis patients. The Centers for Medicare and Medicaid Services recently considered UF rate and target weight achievement measures for ESRD Quality Incentive Program inclusion. The dual measures were intended to promote balance between too aggressive and too conservative fluid removal. The National Quality Forum endorsed the UF rate measure but not the target weight measure. We examined the proposed target weight measure and quantified weight gains if UF rate thresholds were applied without treatment time (TT) extension or interdialytic weight gain (IDWG) reduction. Data were taken from the 2012 database of a large dialysis organization. Analyses considered 152,196 United States hemodialysis patients. We described monthly patient and dialysis facility target weight achievement patterns and examined differences in patient characteristics across target weight achievement status and differences in facilities across target weight measure scores. We computed the cumulative, theoretical 1-month fluid-related weight gain that would occur if UF rates were capped at 13 mL/h/kg without concurrent TT extension or IDWG reduction. Target weight achievement patterns were stable over the year. Patients who did not achieve target weight (post-dialysis weight ≥ 1 kg above or below target weight) tended to be younger, black and dialyze via catheter, and had shorter dialysis vintage, greater body weight, higher UF rate and more missed treatments compared with patients who achieved target weight. Facilities had, on average, 27.1 ± 9.7% of patients with average post-dialysis weight ≥ 1 kg above or below the prescribed target weight. In adjusted analyses, facilities located in the midwest and south and facilities with higher proportions of black and Hispanic patients and higher proportions of patients with shorter TTs were more likely to have unfavorable facility target weight measure scores. Without TT extension or IDWG reduction, UF rate threshold (13 mL/h/kg) implementation led to an average theoretical 1-month, fluid-related weight gain of 1.4 ± 3.0 kg. Target weight achievement patterns vary across clinical subgroups. Implementation of a maximum UF rate threshold without adequate attention to extracellular volume status may lead to fluid-related weight gain.
NASA Astrophysics Data System (ADS)
Fattah, K. A.; Lashin, A.
2016-05-01
Drilling fluid density/type is an important factor in drilling and production operations. Most of encountered problems during rotary drilling are related to drilling mud types and weights. This paper aims to investigate the effect of mud weight on filter cake properties and formation damage through two experimental approaches. In the first approach, seven water-based drilling fluid samples with same composition are prepared with different densities (9.0-12.0 lb/gal) and examined to select the optimum mud weight that has less damage. The second approach deals with investigating the possible effect of the different weighting materials (BaSO4 and CaCO3) on filter cake properties. High pressure/high temperature loss tests and Scanning Electron Microscopy (SEM) analyses were carried out on the filter cake (two selected samples). Data analysis has revealed that mud weigh of 9.5 lb/gal has the less reduction in permeability of ceramic disk, among the seven used mud densities. Above 10.5 ppg the effect of the mud weight density on formation damage is stabilized at constant value. Fluids of CaCO3-based weighting material, has less reduction in the porosity (9.14%) and permeability (25%) of the filter disk properties than the BaSO4-based fluid. The produced filter cake porosity increases (from 0.735 to 0.859) with decreasing of fluid density in case of drilling samples of different densities. The filtration loss tests indicated that CaCO3 filter cake porosity (0.52) is less than that of the BaSO4 weighted material (0.814). The thickness of the filter cake of the BaSO4-based fluid is large and can cause some problems. The SEM analysis shows that some major elements do occur on the tested samples (Ca, Al, Si, and Ba), with dominance of Ca on the expense of Ba for the CaCO3 fluid sample and vice versa. The less effect of 9.5 lb/gal mud sample is reflected in the well-produced inter-particle pore structure and relatively crystal size. A general recommendation is given to minimize the future utilization of Barium Sulfate as a drilling fluid.
Gleadall, Andrew; Pan, Jingzhe; Kruft, Marc-Anton; Kellomäki, Minna
2014-05-01
This paper presents an understanding of how initial molecular weight and initial monomer fraction affect the degradation of bioresorbable polymers in terms of the underlying hydrolysis mechanisms. A mathematical model was used to analyse the effects of initial molecular weight for various hydrolysis mechanisms including noncatalytic random scission, autocatalytic random scission, noncatalytic end scission or autocatalytic end scission. Different behaviours were identified to relate initial molecular weight to the molecular weight half-life and to the time until the onset of mass loss. The behaviours were validated by fitting the model to experimental data for molecular weight reduction and mass loss of samples with different initial molecular weights. Several publications that consider initial molecular weight were reviewed. The effect of residual monomer on degradation was also analysed, and shown to accelerate the reduction of molecular weight and mass loss. An inverse square root law relationship was found between molecular weight half-life and initial monomer fraction for autocatalytic hydrolysis. The relationship was tested by fitting the model to experimental data with various residual monomer contents. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
Chearskul, Supornpim; Delbridge, Elizabeth; Shulkes, Arthur; Proietto, Joseph; Kriketos, Adamandia
2008-05-01
Weight regain after weight loss may not be due primarily to voluntary return to social habits but may be explained by changes in peripheral hormonal signals activating hunger and encouraging feeding behavior. The objective of this study was to investigate physiologic adaptations to weight loss that may encourage weight regain. The study had a within-subject repeated-measure design [12 healthy, obese men, 33-64 y, body mass index (in kg/m(2)) 30-46] and was a clinical intervention investigation of circulating metabolites and hunger-satiety responses before and after weight loss. Measures included anthropometry (bioelectrical impedance, body weight, and waist circumference), concentrations of circulating hormones and metabolites [ketone bodies, free fatty acids (FFAs), insulin, leptin, glucose, and cholecystokinin (CCK)], and measures of hunger and satiety at baseline, 8 wk after weight loss with a very-low-energy diet, and 1 wk after weight maintenance. Weight loss led to a reduction in postprandial CCK secretion (P = 0.016). However, when subjects were ketotic (elevated circulating beta-hydroxybutyrate concentrations), CCK secretion was sustained at concentrations before weight loss. After weight loss, there were reduced postprandial FFA concentrations (P = 0.0005). The presence of ketosis sustained FFA to concentrations before weight loss (P = 0.60). Rapid weight loss of approximately 10% of initial body weight results in a reduction in postprandial CCK and FFA concentrations.
The mechanism of the polymer-induced drag reduction in blood.
Pribush, Alexander; Hatzkelzon, Lev; Meyerstein, Dan; Meyerstein, Naomi
2013-03-01
Literature reports provide evidence that nanomolar concentrations of spaghetti-like, high molecular weight polymers decrease the hydrodynamic resistance of blood thereby improving impaired blood circulation. It has been suggested that the polymer-induced drag reduction is caused by the corralling of red blood cells (RBCs) among extended macromolecules aligned in the flow direction. This mechanism predicts that drag-reducing polymers must affect the conductivity of completely dispersed blood, time-dependent and steady state structural organization of aggregated RBCs at rest. However, experimental results obtained at the concentration of poly(ethylene oxide) (PEO, MW=4 × 10(6)) of 35 ppm show that neither the conductivity of completely dispersed blood, nor the kinetics of RBC aggregation occurring after the stoppage of flow, nor the structural organization of aggregated RBCs in the quiescent blood are affected by PEO. As these results are at odds with the "corralling" hypothesis, it is assumed that the effect of these polymers on the drag is associated with their interactions with local irregularities of disturbed laminar blood flow. Copyright © 2012 Elsevier B.V. All rights reserved.
Xue, Hairong; Tang, Jing; Gong, Hao; Guo, Hu; Fan, Xiaoli; Wang, Tao; He, Jianping; Yamauchi, Yusuke
2016-08-17
PdCo bimetallic nanoparticles (NPs) anchored on three-dimensional (3D) ordered N-doped porous carbon (PdCo/NPC) were fabricated by an in situ synthesis. Within this composite, N-doped porous carbon (NPC) with an ordered mesoporous structure possesses a high surface area (659.6 m(2) g(-1)), which can facilitate electrolyte infiltration. NPC also acts as a perfect 3D conductive network, guaranteeing fast electron transport. In addition, homogeneously distributed PdCo alloy NPs (∼15 nm) combined with the doping of the N element can significantly improve the electrocatalytic activity for the oxygen reduction reaction (ORR). Due to the structural and material superiority, although the weight percentage of PdCo NPs (∼8 wt%) is much smaller than that of commercial Pt/C (20 wt%), the PdCo/NPC catalyst exhibits similar excellent electrocatalytic activity; however, its superior durability and methanol-tolerance ability of the ORR are as great as those of commercial Pt/C in alkaline media.
The importance of body weight and weight management for military personnel.
Naghii, Mohammad Reza
2006-06-01
Weight or fat reduction and maintenance among military personnel and attainment of desired body composition and physical appearance are considered important. A high level of body fat has been shown to have an adverse effect on performance in a number of military activities. The effect of rapid weight loss on performance appears to depend on the method of weight loss, the magnitude of weight loss, and the type of exercise or activity performance test used. Personnel who undertake imprudent weight-loss strategies, that is, personnel who try to change their usual body size by chronically restricting their food and fluid intake, may suffer a number of problems. Overweight personnel and their military coaches are just as susceptible to false ideas about weight loss and dieting as the rest of the community. Inappropriate weight loss causes a loss of lean tissue and can reduce, rather than enhance, performance. The understanding and promotion of safe, effective, appropriate weight-loss and weight-maintenance strategies represent important functions of the military system and officials. The greatest likelihood of success requires an integrated program, both during and after the weight-loss phase, in which assessment, increased energy expenditure through exercise and other daily activities, energy intake reduction, nutrition education, lifestyle changes, environmental changes, and psychological support are all components.
Reducing Weight for Transportation Applications: Technology Challenges and Opportunities
NASA Astrophysics Data System (ADS)
Taub, Alan I.
Today's land, sea and air transportation industries — as a business necessity — are focused on technology solutions that will make vehicles more sustainable in terms of energy, the environment, safety and affordability. Reducing vehicle weight is a key enabler for meeting these challenges as well as increasing payload and improving performance. The potential weight reductions from substituting lightweight metals (advanced high-strength steels, aluminum, magnesium and titanium alloys) are well established. For magnesium castings, weight savings of 60% have been reported [1]. The value of weight reduction depends on the transportation sector and ranges from about 5/kg saved for automobiles to over 500/kg saved for aircraft [2]. The challenge is to optimize the material properties and develop robust, high volume, manufacturing technologies and the associated supply chain to fabricate components and subsystems at the appropriate cost for each application.
Huovinen, Heikki T; Hulmi, Juha J; Isolehto, Juha; Kyröläinen, Heikki; Puurtinen, Risto; Karila, Tuomo; Mackala, Krzysztof; Mero, Antti A
2015-01-01
The aim of this study was to investigate the effects of a 4-week weight reduction period with high protein and reduced carbohydrate intake on body composition, explosive power, speed, serum hormones, and acid-base balance in male track and field jumpers and sprinters. Eight participants were assigned to a high weight reduction group (HWR; energy restriction 750 kcal·d) and 7 to a low weight reduction group (LWR; energy restriction 300 kcal·d). Energy and carbohydrate intake decreased significantly (p ≤ 0.05) only in HWR by 740 ± 330 kcal·d and 130 ± 29 g·d, respectively. Furthermore, total body mass and fat mass decreased (p ≤ 0.05) only in HWR by 2.2 ± 1.0 kg and 1.7 ± 1.6 kg, respectively. Fat-free mass (FFM), serum testosterone, cortisol, and sex hormone-binding globulin did not change significantly. Ca ion and pH decreased (p ≤ 0.05) only in HWR (3.1 ± 2.8% and 0.8 ± 0.8%, respectively), whereas (Equation is included in full-text article.)declined (p ≤ 0.05) in both groups by 19.3 ± 6.2% in HWR and by 13.1 ± 8.5% in LWR. The countermovement jump and 20-m sprint time improved consistently (p ≤ 0.05) only in HWR, by 2.6 ± 2.5 cm and 0.04 ± 0.04 seconds, respectively. Finally, athletes with a fat percentage of 10% or more at the baseline were able to preserve FFM. In conclusion, altered acid-base balance but improved weight-bearing power performance was observed without negative consequences on serum hormones and FFM after a 4-week weight reduction of 0.5 kg·wk achieved by reduced carbohydrate but maintained high protein intake.
Effectiveness of Hypnosis as an Adjunct to Behavioral Weight Management.
ERIC Educational Resources Information Center
Bolocofsky, David N.; And Others
1985-01-01
Subjects (N=109) completed a behavioral weight-management program either with or without the addition of hypnosis. Both interventions resulted in significant weight reduction. At the eight-month and two-year follow-ups, the hypnosis clients showed significant additional weight loss and were more likely to have achieved and maintained their…
vehicles equipped with idle reduction technology may exceed the state's gross and axle weight limits by up vehicle primarily powered by natural gas may exceed the state's gross vehicle weight limits by a weight maximum gross weight may not exceed 82,000 lbs. (Reference New Mexico Statutes 66-7-4
vehicles equipped with idle reduction technology may exceed the state's gross and axle weight limits by up vehicle primarily powered by natural gas may exceed the state's gross vehicle weight limits by a weight and the weight of a comparable vehicle with a diesel tank and fueling system. The NGV maximum gross
Inelastic losses in X-ray absorption theory
NASA Astrophysics Data System (ADS)
Campbell, Luke Whalin
There is a surprising lack of many body effects observed in XAS (X-ray Absorption Spectroscopy) experiments. While collective excitations and other satellite effects account for between 20% and 40% of the spectral weight of the core hole and photoelectron excitation spectrum, the only commonly observed many body effect is a relatively structureless amplitude reduction to the fine structure, typically no more than a 10% effect. As a result, many particle effects are typically neglected in the XAS codes used to predict and interpret modern experiments. To compensate, the amplitude reduction factor is simply fitted to experimental data. In this work, a quasi-boson model is developed to treat the case of XAS, when the system has both a photoelectron and a core hole. We find that there is a strong interference between the extrinsic and intrinsic losses. The interference reduces the excitation amplitudes at low energies where the core hole and photo electron induced excitations tend to cancel. At high energies, the interference vanishes, and the theory reduces to the sudden approximation. The x-ray absorption spectrum including many-body excitations is represented by a convolution of the one-electron absorption spectrum with an energy dependent spectral function. The latter has an asymmetric quasiparticle peak and broad satellite structure. The net result is a phasor sum, which yields the many body amplitude reduction and phase shift of the fine structure oscillations (EXAFS), and possibly additional satellite structure. Calculations for several cases of interest are found to be in reasonable agreement with experiment. Edge singularity effects and deviations from the final state rule arising from this theory are also discussed. The ab initio XAS code FEFF has been extended for calculations of the many body amplitude reduction and phase shift in x-ray spectroscopies. A new broadened plasmon pole self energy is added. The dipole matrix elements are modified to include a projection operator to calculate deviations from the final state rule and edge singularities.
Blonde, Lawrence; Stenlöf, Kaj; Fung, Albert; Xie, John; Canovatchel, William; Meininger, Gary
2016-05-01
Canagliflozin, a sodium glucose co-transporter 2 (SGLT2) inhibitor, has been associated with weight loss in a broad range of patients with type 2 diabetes mellitus (T2DM). This analysis further evaluated changes in body weight and composition with canagliflozin in two 104-week, Phase 3 studies. In Study 1, patients aged 18-80 years (N = 1,450) received canagliflozin 100 or 300 mg or glimepiride as add-on to metformin for a 52-week core treatment period, followed by a 52-week extension period. In Study 2, patients aged 55-80 years (N = 714) received canagliflozin 100 or 300 mg or placebo added to stable background antihyperglycemic agents for a 26-week core treatment period, followed by a 78-week extension period. Percent change from baseline in body weight; proportion of patients with any weight loss, ≥5% weight loss, and ≥10% weight loss; change in body mass index (BMI) and waist circumference; change in body weight across weight-loss quartiles; and changes in body composition were evaluated in both studies. Canagliflozin 100 and 300 mg provided sustained weight loss versus either glimepiride or placebo over 104 weeks. More patients experienced any weight loss and ≥5% weight loss with canagliflozin versus comparator. Across the 3 highest weight-loss quartiles, canagliflozin provided greater weight loss versus glimepiride or placebo. BMI and waist circumference reductions were observed with canagliflozin 100 and 300 mg versus either glimepiride or placebo over 104 weeks; more patients had BMI or waist circumference reductions with canagliflozin versus comparator. Body composition analysis indicated that the majority of weight loss was due to loss of fat mass. Canagliflozin was generally well tolerated, with increased incidence of adverse events related to the SGLT2 inhibition mechanism. Canagliflozin 100 and 300 mg provided sustained reductions in body weight, BMI, and waist circumference in a greater proportion of patients with T2DM versus glimepiride or placebo over 104 weeks. ClinicalTrials.gov NCT00968812, NCT01106651.
Acoustic-noise-optimized diffusion-weighted imaging.
Ott, Martin; Blaimer, Martin; Grodzki, David M; Breuer, Felix A; Roesch, Julie; Dörfler, Arnd; Heismann, Björn; Jakob, Peter M
2015-12-01
This work was aimed at reducing acoustic noise in diffusion-weighted MR imaging (DWI) that might reach acoustic noise levels of over 100 dB(A) in clinical practice. A diffusion-weighted readout-segmented echo-planar imaging (EPI) sequence was optimized for acoustic noise by utilizing small readout segment widths to obtain low gradient slew rates and amplitudes instead of faster k-space coverage. In addition, all other gradients were optimized for low slew rates. Volunteer and patient imaging experiments were conducted to demonstrate the feasibility of the method. Acoustic noise measurements were performed and analyzed for four different DWI measurement protocols at 1.5T and 3T. An acoustic noise reduction of up to 20 dB(A) was achieved, which corresponds to a fourfold reduction in acoustic perception. The image quality was preserved at the level of a standard single-shot (ss)-EPI sequence, with a 27-54% increase in scan time. The diffusion-weighted imaging technique proposed in this study allowed a substantial reduction in the level of acoustic noise compared to standard single-shot diffusion-weighted EPI. This is expected to afford considerably more patient comfort, but a larger study would be necessary to fully characterize the subjective changes in patient experience.
Mitigation of epidemics in contact networks through optimal contact adaptation *
Youssef, Mina; Scoglio, Caterina
2013-01-01
This paper presents an optimal control problem formulation to minimize the total number of infection cases during the spread of susceptible-infected-recovered SIR epidemics in contact networks. In the new approach, contact weighted are reduced among nodes and a global minimum contact level is preserved in the network. In addition, the infection cost and the cost associated with the contact reduction are linearly combined in a single objective function. Hence, the optimal control formulation addresses the tradeoff between minimization of total infection cases and minimization of contact weights reduction. Using Pontryagin theorem, the obtained solution is a unique candidate representing the dynamical weighted contact network. To find the near-optimal solution in a decentralized way, we propose two heuristics based on Bang-Bang control function and on a piecewise nonlinear control function, respectively. We perform extensive simulations to evaluate the two heuristics on different networks. Our results show that the piecewise nonlinear control function outperforms the well-known Bang-Bang control function in minimizing both the total number of infection cases and the reduction of contact weights. Finally, our results show awareness of the infection level at which the mitigation strategies are effectively applied to the contact weights. PMID:23906209
Mitigation of epidemics in contact networks through optimal contact adaptation.
Youssef, Mina; Scoglio, Caterina
2013-08-01
This paper presents an optimal control problem formulation to minimize the total number of infection cases during the spread of susceptible-infected-recovered SIR epidemics in contact networks. In the new approach, contact weighted are reduced among nodes and a global minimum contact level is preserved in the network. In addition, the infection cost and the cost associated with the contact reduction are linearly combined in a single objective function. Hence, the optimal control formulation addresses the tradeoff between minimization of total infection cases and minimization of contact weights reduction. Using Pontryagin theorem, the obtained solution is a unique candidate representing the dynamical weighted contact network. To find the near-optimal solution in a decentralized way, we propose two heuristics based on Bang-Bang control function and on a piecewise nonlinear control function, respectively. We perform extensive simulations to evaluate the two heuristics on different networks. Our results show that the piecewise nonlinear control function outperforms the well-known Bang-Bang control function in minimizing both the total number of infection cases and the reduction of contact weights. Finally, our results show awareness of the infection level at which the mitigation strategies are effectively applied to the contact weights.
NASA Astrophysics Data System (ADS)
Vermisoglou, E. C.; Giannakopoulou, T.; Romanos, G.; Boukos, N.; Psycharis, V.; Lei, C.; Lekakou, C.; Petridis, D.; Trapalis, C.
2017-01-01
Benzidine, a compound bearing aromatic rings and terminal amino groups, was employed for the intercalation and simultaneous reduction of graphite oxide (GO). The aromatic diamine can be intercalated into GO as follows: (1) by grafting with the epoxy groups of GO, (2) by hydrogen bonding with the oxygen containing groups of GO. Stacking between benzidine aromatic rings and unoxidized domains of GO may occur through π-π interaction. The role of benzidine is influenced by pH conditions and the weight ratio GO/benzidine. Two weight ratios were tested i.e. 1:2 and 1:3. Under strong alkaline conditions through K2CO3 addition (pH ∼10.4-10.6) both intercalation and reduction of GO via amino groups occur, while under strong acidic conditions through HCl addition (pH ∼1.4-2.2) π-π stacking is preferred. When no base or acid is added (pH ∼5.2) and the weight ratio is 1:2, there are indications that reduction and π-π stacking occur, while at a GO/benzidine weight ratio 1:3 intercalation via amino groups and reduction seem to dominate. The aforementioned remarks render benzidine a multifunctional tool towards production of reduced graphene oxide. The effect of pH conditions and the GO/benzidine weight ratio on the quality and the electrochemical properties of the produced graphene-based materials were investigated. Cyclic voltammetry measurements using three-electrode cell and KCl aqueous solution as an electrolyte gave specific capacitance values up to ∼178 F/g. When electric double-layer capacitors (EDLC) were fabricated from these materials, the maximum capacitance in organic electrolyte i.e., tetraethyl ammonium tetrafluoroborate (TEABF4) in polycarbonate (PC) was ∼29 F/g.
de Moura, Eduardo Guimarães Hourneaux; Orso, Ivan Roberto Bonotto; Martins, Bruno da Costa; Lopes, Guilherme Sauniti; de Oliveira, Suzana Lopes; Galvão-Neto, Manoel dos Passos; Mancini, Marcio Correa; Santo, Marco Aurélio; Sakai, Paulo; Ramos, Almino Cardoso; Garrido-Júnior, Arthur Belarmino; Halpern, Alfredo; Cecconello, Ivan
2011-07-01
This study aims to evaluate the effectiveness of the duodenojejunal bypass liner (DJBL) in the improvement of insulin resistance and reduction of cardiovascular risk among morbidly obese patients with type 2 diabetes mellitus, using the triglyceride/high-density lipoprotein (HDL) cholesterol ratio, percentage of weight loss, and glycemic control. We used the TG/HDL ratio with a cutoff value of 3.5 to identify patients with insulin resistance. The value of the initial ratio was compared with the ratio obtained 6 months after implantation to evaluate whether an improvement in insulin resistance occurred. We also evaluated the improvement of glycated hemoglobin levels and the weight loss resulted from the use of the device and correlated that with the improvement of the TG/HDL ratio. All patients implanted with the device presented a statistically significant reduction of the HbA1c levels, with most patients (70.3%) obtaining diabetes control with HbA1c levels lower than 7% at the end of the study. All patients also presented a significant weight reduction, with an average loss of 12.6% of their initial weight. We observed an important improvement in insulin resistance and metabolic syndrome, with a significant reduction of the TG/HDL ratio from 5.75 to 4.36 (p < 0.001) and 42.6% of the patients presenting a TG/HDL ratio lower than 3.5 at the end of the study. The DJBL, when used for a period of 6 months, is effective in the control of diabetes, weight loss, improvement of insulin resistance, and decrease of cardiovascular risk among morbidly obese patients with type 2 diabetes mellitus.
Miller, Gary D.; Jenks, Monica Z.; Vendela, Mandolyn; Norris, James L.; Muday, Gloria K.
2012-01-01
Objective. To investigate effects of weight loss on adipokines and health measures in obese older adults with symptomatic knee osteoarthritis. Methods. Participants were randomly assigned to either weight loss (WL) (men: 12, women: 14) or weight stable (WS) group (men: 12, women: 13). WL intervention included meal replacements and structured exercise training. Measurements of leptin, adiponectin, soluble leptin receptor, lifestyle behaviors, and body composition were collected at baseline and 6 months. Univariate analysis of covariance was performed on 6 month variables, and Spearman and partial correlations were made between variables. Results. Weight loss was 13.0% and 6.7% in WL for men and women, respectively. Women in WL had lower whole body and trunk fat than WS. The leptin : adiponectin ratio was lower for women in WL than WS at 6 months, with no group differences in adipokines for men. Leptin and free leptin index correlated with body fat in both genders at baseline. Interestingly, only women showed reductions in leptin (P < 0.100) and correlations between the percentage change leptin and trunk fat and the percentage changes in free leptin index with total fat and trunk fat. Partial correlations between 6 month adipokines after adjustments for covariates and group/time period show potential multivariate influences. Conclusions. In the presence of an effective weight loss intervention in older obese adults, there are significant relationships between weight and fat loss and leptin in women, but not men, suggesting gender-specific features of adipokine metabolism in this age group. PMID:23326650
Nearly Deconfined Spinon Excitations in the Square-Lattice Spin-1 /2 Heisenberg Antiferromagnet
NASA Astrophysics Data System (ADS)
Shao, Hui; Qin, Yan Qi; Capponi, Sylvain; Chesi, Stefano; Meng, Zi Yang; Sandvik, Anders W.
2017-10-01
We study the spin-excitation spectrum (dynamic structure factor) of the spin-1 /2 square-lattice Heisenberg antiferromagnet and an extended model (the J -Q model) including four-spin interactions Q in addition to the Heisenberg exchange J . Using an improved method for stochastic analytic continuation of imaginary-time correlation functions computed with quantum Monte Carlo simulations, we can treat the sharp (δ -function) contribution to the structure factor expected from spin-wave (magnon) excitations, in addition to resolving a continuum above the magnon energy. Spectra for the Heisenberg model are in excellent agreement with recent neutron-scattering experiments on Cu (DCOO )2.4 D2O , where a broad spectral-weight continuum at wave vector q =(π ,0 ) was interpreted as deconfined spinons, i.e., fractional excitations carrying half of the spin of a magnon. Our results at (π ,0 ) show a similar reduction of the magnon weight and a large continuum, while the continuum is much smaller at q =(π /2 ,π /2 ) (as also seen experimentally). We further investigate the reasons for the small magnon weight at (π ,0 ) and the nature of the corresponding excitation by studying the evolution of the spectral functions in the J -Q model. Upon turning on the Q interaction, we observe a rapid reduction of the magnon weight to zero, well before the system undergoes a deconfined quantum phase transition into a nonmagnetic spontaneously dimerized state. Based on these results, we reinterpret the picture of deconfined spinons at (π ,0 ) in the experiments as nearly deconfined spinons—a precursor to deconfined quantum criticality. To further elucidate the picture of a fragile (π ,0 )-magnon pole in the Heisenberg model and its depletion in the J -Q model, we introduce an effective model of the excitations in which a magnon can split into two spinons that do not separate but fluctuate in and out of the magnon space (in analogy to the resonance between a photon and a particle-hole pair in the exciton-polariton problem). The model can reproduce the reduction of magnon weight and lowered excitation energy at (π ,0 ) in the Heisenberg model, as well as the energy maximum and smaller continuum at (π /2 ,π /2 ). It can also account for the rapid loss of the (π ,0 ) magnon with increasing Q and the remarkable persistence of a large magnon pole at q =(π /2 ,π /2 ) even at the deconfined critical point. The fragility of the magnons close to (π ,0 ) in the Heisenberg model suggests that various interactions that likely are important in many materials—e.g., longer-range pair exchange, ring exchange, and spin-phonon interactions—may also destroy these magnons and lead to even stronger spinon signatures than in Cu (DCOO )2.4 D2O .
Age-related changes in the kinetics of human lenses: prevention of the cataract
Pescosolido, Nicola; Barbato, Andrea; Giannotti, Rossella; Komaiha, Chiara; Lenarduzzi, Fiammetta
2016-01-01
The crystalline lens is a transparent, biconvex structure in the eye that, along with the cornea, helps to refract light to be focused on the retina and, by changing shape, it adjusts focal distance (accommodation). The three classes of structural proteins found in the lens are α, β, and γ crystallins. These proteins make up more than 90% of the total dry mass of the eye lens. Other components which can be found are sugars, lipids, water, several antioxidants and low weight molecules. When ageing changes occur in the lens, it causes a gradual reduction in transparency, presbyopia and an increase in the scattering and aberration of light waves as well as a degradation of the optical quality of the eye. The main changes that occur with aging are: 1) reduced diffusion of water from the outside to the inside of the lens and from its cortical to its nuclear zone; 2) crystalline change due to the accumulation of high molecular weight aggregates and insoluble proteins; 3) production of advanced glycation end products (AGEs), lipid accumulation, reduction of reduced glutathione content and destruction of ascorbic acid. Even if effective strategies in preventing cataract onset are not already known, good results have been reached in some cases with oral administration of antioxidant substances such as caffeine, pyruvic acid, epigallocatechin gallate (EGCG), α-lipoic acid and ascorbic acid. Furthermore, methionine sulfoxide reductase A (MSRA) over expression could protect lens cells both in presence and in absence of oxidative stress-induced damage. Nevertheless, promising results have been obtained by reducing ultraviolet-induced oxidative damage. PMID:27803872
Clark, Caron A C; Fang, Hua; Espy, Kimberly Andrews; Filipek, Pauline A; Juranek, Jenifer; Bangert, Barbara; Hack, Maureen; Taylor, H Gerry
2013-05-01
This study examined the relation of cerebral tissue reductions associated with VLBW to patterns of growth in core academic domains. Children born <750 g, 750 to 1,499 g, or >2,500 g completed measures of calculation, mathematical problem solving, and word decoding at time points spanning middle childhood and adolescence. K. A. Espy, H. Fang, D. Charak, N. M. Minich, and H. G. Taylor (2009, Growth mixture modeling of academic achievement in children of varying birth weight risk, Neuropsychology, Vol. 23, pp. 460-474) used growth mixture modeling to identify two growth trajectories (clusters) for each academic domain: an average achievement trajectory and a persistently low trajectory. In this study, 97 of the same participants underwent magnetic resonance imaging (MRI) in late adolescence, and cerebral tissue volumes were used to predict the probability of low growth cluster membership for each domain. Adjusting for whole brain volume (wbv), each 1-cm(3) reduction in caudate volume was associated with a 1.7- to 2.1-fold increase in the odds of low cluster membership for each domain. Each 1-mm(2) decrease in corpus callosum surface area increased these odds approximately 1.02-fold. Reduced cerebellar white matter volume was associated specifically with low calculation and decoding growth, and reduced cerebral white matter volume was associated with low calculation growth. Findings were similar when analyses were confined to the VLBW groups. Reduced volume of structures involved in connectivity, executive attention, and motor control may contribute to heterogeneous academic trajectories among children with VLBW.
Lee, I-Te; Fu, Chia-Po; Lee, Wen-Jane; Liang, Kae-Woei; Lin, Shih-Yi; Wan, Chu-Jen; Sheu, Wayne Huey-Herng
2014-02-13
Obesity, a critical component of metabolic syndrome (MetS), is associated with depression. Deficiency of brain-derived neurotrophic factor (BDNF) is involved in the mechanism of depression. We hypothesized that weight reduction would improve depressive symptoms via increasing BDNF levels in obese men. Male adults with obesity were enrolled in a weight-reduction program for twelve weeks. All subjects underwent daily caloric restriction and an exercise program which was regularly assessed in group classes. Fasting blood samples and Zung Self-Rating Depression Scale (Zung SDS) scores were collected for assessments before and after the study. A total of 36 subjects completed this program. The average reduction in body weight was 8.4 ± 5.1 kg (8.8 ± 5.1%, P < 0.001). Fasting serum BDNF significantly increased after the study (from 40.4 ± 7.8 to 46.9 ± 8.9 ng/ml, P < 0.001). However, the depression symptoms, as assessed by the Zung Self-Rating Depression Scale (Zung SDS), did not reduce significantly (P = 0.486). Divided into subgroups based on changes in BDNF, Zung SDS scores were significantly reduced in subjects with greater BDNF increase than in those with minor BDNF change (-3.9 ± 6.2 vs. 2.3 ± 6.7, P = 0.009). The increased percentage of BDNF was inversely correlated with the change in Zung SDS (r = -0.380, P = 0.022). Multivariate regression analysis showed that reduction in BDNF was independently associated with change in Zung SDS (95% confidence interval -0.315 to -0.052, P = 0.008). Zung SDS only significantly improved in men with increased fasting BDNF levels after a lifestyle intervention. (NCT01065753, ClinicalTrials.gov).
Sun, Xiaojun; Guo, Zhimou; Yu, Mengqi; Lin, Chao; Sheng, Anran; Wang, Zhiyu; Linhardt, Robert J; Chi, Lianli
2017-01-06
Low molecular weight heparins (LMWHs) are important anticoagulant drugs that are prepared through depolymerization of unfractionated heparin. Based on the types of processing reactions and the structures of the products, LMWHs can be divided into different classifications. Enoxaparin is prepared by benzyl esterification and alkaline depolymerization, while dalteparin and nadroparin are prepared through nitrous acid depolymerization followed by borohydride reduction. Compositional analysis of their basic building blocks is an effective way to provide structural information on heparin and LMWHs. However, most current compositional analysis methods have been limited to heparin and enoxaparin. A sensitive and comprehensive approach is needed for detailed investigation of the structure of LMWHs prepared through nitrous acid depolymerization, especially their characteristic saturated non-reducing end (NRE) and 2,5-anhydro-d-mannitol reducing end (RE). A maltose modified hydrophilic interaction column offers improved separation of complicated mixtures of acidic disaccharides and oligosaccharides. A total of 36 basic building blocks were unambiguously identified by high-resolution tandem mass spectrometry (MS). Multiple reaction monitoring (MRM) MS/MS quantification was developed and validated in the analysis of dalteparin and nadroparin samples. Each group of building blocks revealed different aspects of the properties of LMWHs, such as functional motifs required for anticoagulant activity, the structure of heparin starting materials, cleavage sites in the depolymerization reaction, and undesired structural modifications resulting from side reactions. Copyright © 2016 Elsevier B.V. All rights reserved.
Fong, Shirley Siu Ming
2015-01-01
Weight reduction that corresponds with lifestyle modification is difficult to foster. The theory of planned behaviour has been actively cited in explaining health-related behaviour. This review evaluated the application of the theory of planned behaviour to weight-loss behaviour. Among the three reviewed papers, cross-sectional survey designs and subjective outcome measurements were commonly applied. All of the studies recruited obese female adults as participants, limiting the generalisability of the studies’ findings. The theory of planned behaviour can be effectively applied in weight-reduction programmes targeting female obese patients. This review confirmed critiques citing the limitations of experimental studies, the subjective measurement of behaviour and short follow-up periods. PMID:28070350
New Design Concept for a Lifting Platform Made of Composite Material
NASA Astrophysics Data System (ADS)
Solazzi, L.; Scalmana, R.
2013-08-01
Elevating work platforms are hoists equipment that are increasingly used in many applications, like in the construction industry and in the maintenance field. The maintenance of the hub of the wind turbines, for example, can be done through the use of a working platform; these structures have to reach great heights and obviously they have to satisfy the constraints induced by the highway standards, like the maximum axle load and the maximum overall dimensions. To satisfy these requests the material of the structures changed from the classic structural steel (S235 JR, S275 JR or S355JR) to high strength steel (S700 to S1100 or more), characterized by a significantly higher specific resistance. The idea of this paper is to use a composite material for the construction of the arms of an elevating platform in order to reduce the global weight of the machine. The analyses on the new kind of platform show the technical possibility to change the material of the arms with composite materials and this produces a significant reduction of the weight of the machine components, about 50 %. Being a feasibility study, still remain open some problems such as the mechanical behavior of the used composite materials (fatigue, environment effects, etc.).
Carbon nanofibers obtained from electrospinning process
NASA Astrophysics Data System (ADS)
Bovi de Oliveira, Juliana; Müller Guerrini, Lília; Sizuka Oishi, Silvia; Rogerio de Oliveira Hein, Luis; dos Santos Conejo, Luíza; Cerqueira Rezende, Mirabel; Cocchieri Botelho, Edson
2018-02-01
In recent years, reinforcements consisting of carbon nanostructures, such as carbon nanotubes, fullerenes, graphenes, and carbon nanofibers have received significant attention due mainly to their chemical inertness and good mechanical, electrical and thermal properties. Since carbon nanofibers comprise a continuous reinforcing with high specific surface area, associated with the fact that they can be obtained at a low cost and in a large amount, they have shown to be advantageous compared to traditional carbon nanotubes. The main objective of this work is the processing of carbon nanofibers, using polyacrylonitrile (PAN) as a precursor, obtained by the electrospinning process via polymer solution, with subsequent use for airspace applications as reinforcement in polymer composites. In this work, firstly PAN nanofibers were produced by electrospinning with diameters in the range of (375 ± 85) nm, using a dimethylformamide solution. Using a furnace, the PAN nanofiber was converted into carbon nanofiber. Morphologies and structures of PAN and carbon nanofibers were investigated by scanning electron microscopy, Raman Spectroscopy, thermogravimetric analyses and differential scanning calorimeter. The resulting residual weight after carbonization was approximately 38% in weight, with a diameters reduction of 50%, and the same showed a carbon yield of 25%. From the analysis of the crystalline structure of the carbonized material, it was found that the material presented a disordered structure.
It is Time to Ban Rapid Weight Loss from Combat Sports.
Artioli, Guilherme G; Saunders, Bryan; Iglesias, Rodrigo T; Franchini, Emerson
2016-11-01
Most competitions in combat sports are divided into weight classes, theoretically allowing for fairer and more evenly contested disputes between athletes of similar body size, strength and agility. It has been well documented that most athletes, regardless of the combat sports discipline, reduce significant amounts of body weight in the days prior to competition to qualify for lighter weight classes. Rapid weight loss is characterised by the reduction of a significant amount of body weight (typically 2-10 %, although larger reductions are often seen) in a few days prior to weigh-in (mostly in the last 2-3 days) achieved by a combination of methods that include starvation, severe restriction of fluid intake and intentional sweating. In doing so, athletes try to gain a competitive advantage against lighter, smaller and weaker opponents. Such a drastic and rapid weight reduction is only achievable via a combination of aggressive strategies that lead to hypohydration and starvation. The negative impact of these procedures on health is well described in the literature. Although the impact of rapid weight loss on performance is debated, there remains robust evidence showing that rapid weight loss may not impair performance, and translates into an actual competitive advantage. In addition to the health and performance implications, rapid weight loss clearly breaches fair play and stands against the spirit of the sport because an athlete unwilling to compete having rapidly reduced weight would face unfair contests against opponents who are 'artificially' bigger and stronger. The World Anti-Doping Agency Code states that a prohibited method must meet at least two of the following criteria: (1) enhances performance; (2) endangers an athlete's health; and (3) violates the spirit of the sport. We herein argue that rapid weight loss clearly meets all three criteria and, therefore, should be banned from the sport. To quote the World Anti-Doping Agency Code, this would "protect the athletes' fundamental right to participate in a doping-free sport and thus promote health, fairness and equality".
The influence of weight loss on anaerobic threshold in obese women.
Zak-Golab, Agnieszka; Zahorska-Markiewicz, Barbara; Langfort, Józef; Kocelak, Piotr; Holecki, Michal; Mizia-Stec, Katarzyna; Olszanecka-Glinianowicz, Magdalena; Chudek, Jerzy
2010-01-01
Obesity is associated with decreased physical activity. The aim of the study was to assess the anaerobic threshold in obese and normal weight women and to analyse the effect of weight-reduction therapy on the determined thresholds. 42 obese women without concomitant disease (age 30.5 ± 6.9y; BMI 33.6 ± 3.7 kg·m(-2)) and 19 healthy normal weight women (age 27.6 ± 7.0y; BMI 21.2 ± 1.9 kg·m(-2)) performed cycle ergometer incremental ramp exercise test up to exhaustion. The test was repeated in 19 obese women after 12.3 ± 4.2% weight loss. The lactate threshold (LT) and the ventilatory threshold (VT) were determined. Obese women had higher lactate (expressed as oxygen consumption) and ventilator threshold than normal weight women. The lactate threshold was higher than ventilatory one both in obese and normal weight women (1.11 ± 0.21 vs 0.88 ± 0.18 L·min(-1), p < 0.001; 0.94 ± 0.15 vs 0.79 ± 0.23 L·min(- 1), p < 0.01, respectively). After weight reduction therapy neither the lactate nor the ventilatory threshold changed significantly. The results concluded that; 1. The higher lactate threshold noted in obese women may be related to the increased fat acid usage in metabolism. 2. Both in obese and normal weight women lactate threshold appears at higher oxygen consumption than ventilatory threshold. 3. The obtained weight reduction, without weight normalisation was insufficient to cause significant changes of lactate and ventilatory thresholds in obese women. Key pointsResults showed that adolescent young female gymnasts have an altered serum inflammatory markers and endothelial activation, compared to their less physically active peers.Physical activities improved immune system.Differences in these biochemical data kept significant after adjustment for body weight and height.
Supervised orthogonal discriminant subspace projects learning for face recognition.
Chen, Yu; Xu, Xiao-Hong
2014-02-01
In this paper, a new linear dimension reduction method called supervised orthogonal discriminant subspace projection (SODSP) is proposed, which addresses high-dimensionality of data and the small sample size problem. More specifically, given a set of data points in the ambient space, a novel weight matrix that describes the relationship between the data points is first built. And in order to model the manifold structure, the class information is incorporated into the weight matrix. Based on the novel weight matrix, the local scatter matrix as well as non-local scatter matrix is defined such that the neighborhood structure can be preserved. In order to enhance the recognition ability, we impose an orthogonal constraint into a graph-based maximum margin analysis, seeking to find a projection that maximizes the difference, rather than the ratio between the non-local scatter and the local scatter. In this way, SODSP naturally avoids the singularity problem. Further, we develop an efficient and stable algorithm for implementing SODSP, especially, on high-dimensional data set. Moreover, the theoretical analysis shows that LPP is a special instance of SODSP by imposing some constraints. Experiments on the ORL, Yale, Extended Yale face database B and FERET face database are performed to test and evaluate the proposed algorithm. The results demonstrate the effectiveness of SODSP. Copyright © 2013 Elsevier Ltd. All rights reserved.
Wilson, George; Chester, Neil; Eubank, Martin; Crighton, Ben; Drust, B; Morton, James P; Close, Graeme L
2012-06-15
Professional jockeys are unique amongst weight-making athletes as they are often required to make weight daily and in many cases, all year round. Common methods employed by jockeys include dehydration, severe calorie restriction and sporadic eating, all of which have adverse health effects. In contrast, this paper outlines a structured diet and exercise plan employed by a 22 year old professional National Hunt jockey in an attempt to reduce weight from 70.3 to 62.6 kg that does not rely on any of the aforementioned techniques. Prior to the intervention, the client's typical daily energy intake was 8.2 MJ (42% CHO, 36% fats, 22% protein) consumed in two meals only. During the 9-week intervention, daily energy intake was approximately equivalent to resting metabolic rate and consumed as 6 meals per day (7.6 MJ, 46% CHO, 19% fats, 36% protein). This change in frequency and composition of energy intake combined with structured exercise, resulted in a total body mass loss of 8 kg, corresponding to reductions in percent body fat from 14.5 to 9%. No form of intentional dehydration occurred throughout this period and mean urine osmolality was 285 mOs·kg-1 (SD 115 mOs·kg-1). In addition, positive changes in mood scores (BRUMS scale) also occurred. The client was now able to ride light for the first time in his career thereby challenging the cultural practices inherent to the sport.
Acoustic noise reduction in T 1- and proton-density-weighted turbo spin-echo imaging.
Ott, Martin; Blaimer, Martin; Breuer, Felix; Grodzki, David; Heismann, Björn; Jakob, Peter
2016-02-01
To reduce acoustic noise levels in T 1-weighted and proton-density-weighted turbo spin-echo (TSE) sequences, which typically reach acoustic noise levels up to 100 dB(A) in clinical practice. Five acoustic noise reduction strategies were combined: (1) gradient ramps and shapes were changed from trapezoidal to triangular, (2) variable-encoding-time imaging was implemented to relax the phase-encoding gradient timing, (3) RF pulses were adapted to avoid the need for reversing the polarity of the slice-rewinding gradient, (4) readout bandwidth was increased to provide more time for gradient activity on other axes, (5) the number of slices per TR was reduced to limit the total gradient activity per unit time. We evaluated the influence of each measure on the acoustic noise level, and conducted in vivo measurements on a healthy volunteer. Sound recordings were taken for comparison. An overall acoustic noise reduction of up to 16.8 dB(A) was obtained by the proposed strategies (1-4) and the acquisition of half the number of slices per TR only. Image quality in terms of SNR and CNR was found to be preserved. The proposed measures in this study allowed a threefold reduction in the acoustic perception of T 1-weighted and proton-density-weighted TSE sequences compared to a standard TSE-acquisition. This could be achieved without visible degradation of image quality, showing the potential to improve patient comfort and scan acceptability.
Advanced Subsonic Airplane Design and Economic Studies
NASA Technical Reports Server (NTRS)
Liebeck, Robert H.; Andrastek, Donald A.; Chau, Johnny; Girvin, Raquel; Lyon, Roger; Rawdon, Blaine K.; Scott, Paul W.; Wright, Robert A.
1995-01-01
A study was made to examine the effect of advanced technology engines on the performance of subsonic airplanes and provide a vision of the potential which these advanced engines offered. The year 2005 was selected as the entry-into-service (EIS) date for engine/airframe combination. A set of four airplane classes (passenger and design range combinations) that were envisioned to span the needs for the 2005 EIS period were defined. The airframes for all classes were designed and sized using 2005 EIS advanced technology. Two airplanes were designed and sized for each class: one using current technology (1995) engines to provide a baseline, and one using advanced technology (2005) engines. The resulting engine/airframe combinations were compared and evaluated on the basis on sensitivity to basic engine performance parameters (e.g. SFC and engine weight) as well as DOC+I. The advanced technology engines provided significant reductions in fuel burn, weight, and wing area. Average values were as follows: reduction in fuel burn = 18%, reduction in wing area = 7%, and reduction in TOGW = 9%. Average DOC+I reduction was 3.5% using the pricing model based on payload-range index and 5% using the pricing model based on airframe weight. Noise and emissions were not considered.
Nitrogen Fixation (Acetylene Reduction) Associated with Duckweed (Lemnaceae) Mats
Zuberer, D. A.
1982-01-01
Duckweed (Lemnaceae) mats in Texas and Florida were investigated, using the acetylene reduction assay, to determine whether nitrogen fixation occurred in these floating aquatic macrophyte communities. N2-fixing microorganisms were enumerated by plating or most-probable-number techniques, using appropriate N-free media. Results of the investigations indicated that substantial N2-fixation (C2H2) was associated with duckweed mats in Texas and Florida. Acetylene reduction values ranged from 1 to 18 μmol of C2H4 g (dry weight)−1 day−1 for samples incubated aerobically in light. Dark N2 fixation was always two- to fivefold lower. 3-(3,4-Dichlorophenyl)-1,1-dimethylurea (7 to 10 μM) reduced acetylene reduction to levels intermediate between light and dark incubation. Acetylene reduction was generally greatest for samples incubated anaerobically in the light. It was estimated that 15 to 20% of the N requirement of the duckweed could be supplied through biological nitrogen fixation. N2-fixing heterotrophic bacteria (105 cells g [wet weight]−1 and cyanobacteria (105 propagules g [wet weight]−1 were associated with the duckweed mats. Azotobacter sp. was not detected in these investigations. One diazotrophic isolate was classified as Klebsiella. PMID:16345992
US Food Industry Progress During the National Salt Reduction Initiative: 2009-2014.
Curtis, Christine J; Clapp, Jenifer; Niederman, Sarah A; Ng, Shu Wen; Angell, Sonia Y
2016-10-01
To assess the US packaged food industry's progress from 2009 to 2014, when the National Salt Reduction Initiative had voluntary, category-specific sodium targets with the goal of reducing sodium in packaged and restaurant foods by 25% over 5 years. Using the National Salt Reduction Initiative Packaged Food Database, we assessed target achievement and change in sales-weighted mean sodium density in top-selling products in 61 food categories in 2009 (n = 6336), 2012 (n = 6898), and 2014 (n = 7396). In 2009, when the targets were established, no categories met National Salt Reduction Initiative 2012 or 2014 targets. By 2014, 26% of categories met 2012 targets and 3% met 2014 targets. From 2009 to 2014, the sales-weighted mean sodium density declined significantly in almost half of all food categories (43%; 26/61 categories). Overall, sales-weighted mean sodium density declined significantly (by 6.8%; P < .001). National target setting with monitoring through a partnership of local, state, and national health organizations proved feasible, but industry progress was modest. The US Food and Drug Administration's proposed voluntary targets will be an important step in achieving more substantial sodium reductions.
Harris, Wendy; Zhang, You; Yin, Fang-Fang; Ren, Lei
2017-03-01
To investigate the feasibility of using structural-based principal component analysis (PCA) motion-modeling and weighted free-form deformation to estimate on-board 4D-CBCT using prior information and extremely limited angle projections for potential 4D target verification of lung radiotherapy. A technique for lung 4D-CBCT reconstruction has been previously developed using a deformation field map (DFM)-based strategy. In the previous method, each phase of the 4D-CBCT was generated by deforming a prior CT volume. The DFM was solved by a motion model extracted by a global PCA and free-form deformation (GMM-FD) technique, using a data fidelity constraint and deformation energy minimization. In this study, a new structural PCA method was developed to build a structural motion model (SMM) by accounting for potential relative motion pattern changes between different anatomical structures from simulation to treatment. The motion model extracted from planning 4DCT was divided into two structures: tumor and body excluding tumor, and the parameters of both structures were optimized together. Weighted free-form deformation (WFD) was employed afterwards to introduce flexibility in adjusting the weightings of different structures in the data fidelity constraint based on clinical interests. XCAT (computerized patient model) simulation with a 30 mm diameter lesion was simulated with various anatomical and respiratory changes from planning 4D-CT to on-board volume to evaluate the method. The estimation accuracy was evaluated by the volume percent difference (VPD)/center-of-mass-shift (COMS) between lesions in the estimated and "ground-truth" on-board 4D-CBCT. Different on-board projection acquisition scenarios and projection noise levels were simulated to investigate their effects on the estimation accuracy. The method was also evaluated against three lung patients. The SMM-WFD method achieved substantially better accuracy than the GMM-FD method for CBCT estimation using extremely small scan angles or projections. Using orthogonal 15° scanning angles, the VPD/COMS were 3.47 ± 2.94% and 0.23 ± 0.22 mm for SMM-WFD and 25.23 ± 19.01% and 2.58 ± 2.54 mm for GMM-FD among all eight XCAT scenarios. Compared to GMM-FD, SMM-WFD was more robust against reduction of the scanning angles down to orthogonal 10° with VPD/COMS of 6.21 ± 5.61% and 0.39 ± 0.49 mm, and more robust against reduction of projection numbers down to only 8 projections in total for both orthogonal-view 30° and orthogonal-view 15° scan angles. SMM-WFD method was also more robust than the GMM-FD method against increasing levels of noise in the projection images. Additionally, the SMM-WFD technique provided better tumor estimation for all three lung patients compared to the GMM-FD technique. Compared to the GMM-FD technique, the SMM-WFD technique can substantially improve the 4D-CBCT estimation accuracy using extremely small scan angles and low number of projections to provide fast low dose 4D target verification. © 2017 American Association of Physicists in Medicine.
Regional body composition changes exhibit opposing effects on coronary heart disease risk factors.
Okura, Tomohiro; Nakata, Yoshio; Yamabuki, Keisuke; Tanaka, Kiyoji
2004-05-01
We investigated how regional body composition measured by dual-energy X-ray absorptiometry (DXA) is associated with risk factors for coronary heart disease (CHD) during weight reduction in obese women. Data were gathered from 128 overweight and obese women, aged 34 to 66 years, during a 14-week intervention study with diet and exercise. Regional (arms, legs, and trunk) fat tissue (FT) and lean soft tissue (LST) were measured by DXA. The FT change in legs correlated negatively with changes in diastolic blood pressure, low-density lipoprotein cholesterol (LDL-C), fasting plasma glucose (FPG), and the number of CHD risk factors per subject (r=-0.17, P<0.05 to -0.26, P<0.01) in response to weight reduction, whereas truncal FT change had positive correlations with changes in triglycerides, LDL-C, FPG, and the number of CHD risk factors per subject (r=0.17, P<0.05 to 0.25, P<0.01). LST change in legs correlated negatively with changes in systolic blood pressure, FPG, and the number of risk factors (r=-0.20 to -0.21, P<0.05). Regional body composition information is important for evaluating improvement of CHD risk factors during weight-reduction treatment for obesity; differential FTs had opposing effects on CHD risk factors during weight reduction in obese women.
Pi-Sunyer, F. Xavier
2010-01-01
Patients with type 2 diabetes, approximately 85% of whom are overweight or obese, often have an increased incidence of cardiovascular disease (CVD) risk factors such as hypertension and dyslipidemia. Both type 2 diabetes and obesity are independent risk factors for CVD. Unfortunately, many therapies aimed at maintaining and improving glucose control are associated with weight gain. Among the older antidiabetes agents, most, including the insulin secretagogues and sensitizers, can lead to weight gain, except for metformin, which is weight-neutral. Among the newer agents, the dipeptidyl peptidase-4 inhibitors generally are weight-neutral in addition to lowering glucose, while the glucagon-like peptide–1 receptor agonists lead to weight reduction. Patients with type 2 diabetes are at an increased risk for both diabetes-and CV-related outcomes, and weight reduction is an important component of diabetes management. Weight gain in patients with type 2 diabetes can contribute to patient frustration and may negatively impact their compliance to therapeutic regimens. The selection of antidiabetes agents that not only improve glucose control but reduce or have a neutral effect on weight with beneficial effects on lipids are ideal options for managing patients with type 2 diabetes. PMID:19820278
Bone, body weight, and weight reduction: what are the concerns?
Shapses, Sue A; Riedt, Claudia S
2006-06-01
Of the U.S. population, 65% is either overweight or obese, and weight loss is recommended to reduce co-morbid conditions. However, bone mobilization and loss may also occur with weight loss. The risk for bone loss depends on initial body weight, age, gender, physical activity, and conditions of dieting such as the extent of energy restriction and specific levels of nutrient intake. Older populations are more prone to bone loss with weight loss; in women, this is due at least in part to a reduced dietary Ca intake and/or efficiency of absorption. Potential hormonal mechanisms regulating bone loss during weight loss are discussed, including decreases in estrogen, leptin, glucagon-like peptide-2, growth hormone, and insulin-like growth factor-1, or an increase in cortisol. In contrast, the rise in adiponectin and ghrelin with weight reduction should not be detrimental to bone. Combining energy restriction with exercise does not necessarily prevent bone loss, but may attenuate loss as was shown with additional Ca intake or osteoporosis medications. Future controlled weight loss trials should be designed to further address mechanisms influencing the density and quality of bone sites vulnerable to fracture, in the prevention of osteoporosis.
Parent predictors of child weight change in family based behavioral obesity treatment.
Boutelle, Kerri N; Cafri, Guy; Crow, Scott J
2012-07-01
Family based behavioral treatment for overweight and obese children includes parenting skills targeting the modification of child eating and activity change. The purpose of this study was to examine parenting skills and parent weight change as predictors of child weight change in a sample of 80 parent/child dyads who were enrolled in a family based behavioral weight loss program for childhood obesity. Eighty overweight and obese children and their parents who enrolled in treatment in two sites were included in the study. Variables included those related to parent modeling (parent BMI), home food environment, parenting (parent and child report), and demographics. Results suggested that parent BMI change was a significant predictor of child weight, in that a reduction of 1 BMI unit in the parent was associated with a 0.255 reduction in child BMI. None of the other variables were significant in the final model. This study is consistent with other research showing that parent weight change is a key contributor to child weight change in behavioral treatment for childhood obesity. Researchers and clinicians should focus on encouraging parents to lose weight to assist their overweight and obese child in weight management.
Evaluation of levee setbacks for flood-loss reduction, Middle Mississippi River, USA
NASA Astrophysics Data System (ADS)
Dierauer, Jennifer; Pinter, Nicholas; Remo, Jonathan W. F.
2012-07-01
SummaryOne-dimensional hydraulic modeling and flood-loss modeling were used to test the effectiveness of levee setbacks for flood-loss reduction along the Middle Mississippi River (MMR). Four levee scenarios were assessed: (1) the present-day levee configuration, (2) a 1000 m levee setback, (3) a 1500 m levee setback, and (4) an optimized setback configuration. Flood losses were estimated using FEMA's Hazus-MH (Hazards US Multi-Hazard) loss-estimation software on a structure-by-structure basis for a range of floods from the 2- to the 500-year events. These flood-loss estimates were combined with a levee-reliability model to calculate probability-weighted damage estimates. In the simplest case, the levee setback scenarios tested here reduced flood losses compared to current conditions for large, infrequent flooding events but increased flood losses for smaller, more frequent flood events. These increases occurred because levee protection was removed for some of the existing structures. When combined with buyouts of unprotected structures, levee setbacks reduced flood losses for all recurrence intervals. The "optimized" levee setback scenario, involving a levee configuration manually planned to protect existing high-value infrastructure, reduced damages with or without buyouts. This research shows that levee setbacks in combination with buyouts are an economically viable approach for flood-risk reduction along the study reach and likely elsewhere where levees are widely employed for flood control. Designing a levee setback around existing high-value infrastructure can maximize the benefit of the setback while simultaneously minimizing the costs. The optimized levee setback scenario analyzed here produced payback periods (costs divided by benefits) of less than 12 years. With many aging levees failing current inspections across the US, and flood losses spiraling up over time, levee setbacks are a viable solution for reducing flood exposure and flood levels.
Genotoxicity testing of peptides: Folate deprivation as a marker of exaggerated pharmacology
DOE Office of Scientific and Technical Information (OSTI.GOV)
Guérard, Melanie, E-mail: melanie.guerard@roche.com; Zeller, Andreas; Festag, Matthias
2014-09-15
The incidence of micronucleated-cells is considered to be a marker of a genotoxic event and can be caused by direct- or indirect-DNA reactive mechanisms. In particular, small increases in the incidence of micronuclei, which are not associated with toxicity in the target tissue or any structurally altering properties of the compound, trigger the suspicion that an indirect mechanism could be at play. In a bone marrow micronucleus test of a synthetic peptide (a dual agonist of the GLP-1 and GIP receptors) that had been integrated into a regulatory 13-week repeat-dose toxicity study in the rat, small increases in the incidencemore » of micronuclei had been observed, together with pronounced reductions in food intake and body weight gain. Because it is well established that folate plays a crucial role in maintaining genomic integrity and pronounced reductions in food intake and body weight gain were observed, folate levels were determined from plasma samples initially collected for toxicokinetic analytics. A dose-dependent decrease in plasma folate levels was evident after 4 weeks of treatment at the mid and high dose levels, persisted until the end of the treatment duration of 13-weeks and returned to baseline levels during the recovery period of 4 weeks. Based on these properties, and the fact that the compound tested (peptide) per se is not expected to reach the nucleus and cause DNA damage, the rationale is supported that the elevated incidence of micronucleated polychromatic erythrocytes is directly linked to the exaggerated pharmacology of the compound resulting in a decreased folate level. - Highlights: • A synthetic peptide has been evaluated for potential genotoxicity • Small increases in an integrated (13-weeks) micronucleus test were observed • Further, animals had a pronounced reductions in food intake and body weight gain • A dose-dependent decrease in plasma folate levels was evident from week 4 onwards • Elevated micronuclei-incidence due to the exaggerated pharmacology.« less
Stendell-Hollis, Nicole R; Thompson, Patricia A; West, Julie L; Wertheim, Betsy C; Thomson, Cynthia A
2013-01-01
Of postpartum women, 15%-20% retain ≥ 5 kg of their gestational weight gain, increasing risk for adult weight gain. Postpartum women are also in a persistent elevated inflammatory state. Both factors could increase the risk of obesity-related chronic disease. We hypothesized that breastfeeding women randomized to a Mediterranean-style (MED) diet for 4 months would demonstrate significantly greater reductions in body weight, body fat, and inflammation than women randomized to the U.S. Department of Agriculture's (USDA) MyPyramid diet for Pregnancy and Breastfeeding (comparison diet). A randomized, controlled dietary intervention trial was conducted in 129 overweight (body mass index [BMI] 27.2 ± 4.9 kg/m(2)), mostly exclusively breastfeeding (73.6%) women who were a mean 17.5 weeks postpartum. Dietary change was assessed using a validated Food Frequency Questionnaire (FFQ) before and after intervention as well as plasma fatty acid measures (gas chromatography/flame ionization detector [GC/FID]). Anthropometric measurements and biomarkers of inflammation, tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), also were assessed at baseline and 4 months via enzyme-linked immunosorbent assay (ELISA). Participants in both diet groups demonstrated significant (p<0.001) reductions in body weight (-2.3 ± 3.4 kg and -3.1 ± 3.4 kg for the MED and comparison diets, respectively) and significant (p ≤ 0.002) reductions in all other anthropometric measurements; no significant between-group differences were shown as hypothesized. A significant decrease in TNF-α but not IL-6 was also demonstrated in both diet groups, with no significant between-group difference. Both diets support the promotion of postpartum weight loss and reduction in inflammation (TNF-α) in breastfeeding women.
Fleischhacker, W Wolfgang; Heikkinen, Martti E; Olié, Jean-Pierre; Landsberg, Wally; Dewaele, Patricia; McQuade, Robert D; Loze, Jean-Yves; Hennicken, Delphine; Kerselaers, Wendy
2010-09-01
Clozapine is associated with significant weight gain and metabolic disturbances. This multicentre, randomized study comprised a double-blind, placebo-controlled treatment phase of 16 wk, and an open-label extension phase of 12 wk. Outpatients who met DSM-IV-TR criteria for schizophrenia, who were not optimally controlled while on stable dosage of clozapine for > or =3 months and had experienced weight gain of > or =2.5 kg while taking clozapine, were randomized (n=207) to aripiprazole at 5-15 mg/d or placebo, in addition to a stable dose of clozapine. The primary endpoint was mean change from baseline in body weight at week 16 (last observation carried forward). Secondary endpoints included clinical efficacy, body mass index (BMI) and waist circumference. A statistically significant difference in weight loss was reported for aripiprazole vs. placebo (-2.53 kg vs. -0.38 kg, respectively, difference=-2.15 kg, p<0.001). Aripiprazole-treated patients also showed BMI (median reduction 0.8 kg/m(2)) and waist circumference reduction (median reduction 2.0 cm) vs. placebo (no change in either parameter, p<0.001 and p=0.001, respectively). Aripiprazole-treated patients had significantly greater reductions in total and low-density lipoprotein (LDL) cholesterol. There were no significant differences in Positive and Negative Syndrome Scale total score changes between groups but Clinical Global Impression Improvement and Investigator's Assessment Questionnaire scores favoured aripiprazole over placebo. Safety and tolerability were generally comparable between groups. Combining aripiprazole and clozapine resulted in significant weight, BMI and fasting cholesterol benefits to patients suboptimally treated with clozapine. Improvements may reduce metabolic risk factors associated with clozapine treatment.
Solah, Vicky A.; Kerr, Deborah A.; Hunt, Wendy J.; Johnson, Stuart K.; Boushey, Carol J.; Delp, Edward J.; Meng, Xingqiong; Gahler, Roland J.; James, Anthony P.; Mukhtar, Aqif S.; Fenton, Haelee K.; Wood, Simon
2017-01-01
Fibre supplementation can potentially reduce energy intake and contribute to weight loss. The mechanism may be reduced frequency of eating, resulting in reduced food consumption. The objective of this research was to determine the effectiveness of fibre supplementation with PolyGlycopleX® (PGX®), on body weight and composition, frequency of eating and dietary intake in 118 overweight adults. In a three-arm, parallel, blind, randomised controlled trial participants were randomised to one of three groups; 4.5 g PGX as softgels (PGXS), 5 g PGX granules (PGXG) or 5 g rice flour (RF) control. Prior to supplementation and at 12 weeks, participants captured before and after images of all food and beverages consumed within 4 days using a mobile food record app (mFR). The mFR images were analysed for food group serving sizes and number of eating occasions. In the PGXG group, intention-to-treat analysis showed there was a significant reduction in waist circumference (2.5 cm; p = 0.003). Subgroup analysis showed that PGXG supplementation at the recommended dose resulted in a reduction in body weight (−1.4 ± 0.10 kg, p < 0.01), body mass index (BMI) reduction (−0.5 ± 0.10, p < 0.01), reduced number of eating occasions (−1.4 ± 1.2, p < 0.01) and a reduced intake of grain food (−1.52 ± 1.84 serves, p = 0.019). PGXG at the recommended dose resulted in a reduction in weight and BMI which was significantly greater than that for RF (p = 0.001). These results demonstrate the potential benefits of PGX fibre in controlling frequency of eating and in weight loss. PMID:28212353
Solah, Vicky A; Kerr, Deborah A; Hunt, Wendy J; Johnson, Stuart K; Boushey, Carol J; Delp, Edward J; Meng, Xingqiong; Gahler, Roland J; James, Anthony P; Mukhtar, Aqif S; Fenton, Haelee K; Wood, Simon
2017-02-16
Fibre supplementation can potentially reduce energy intake and contribute to weight loss. The mechanism may be reduced frequency of eating, resulting in reduced food consumption. The objective of this research was to determine the effectiveness of fibre supplementation with PolyGlycopleX® (PGX®), on body weight and composition, frequency of eating and dietary intake in 118 overweight adults. In a three-arm, parallel, blind, randomised controlled trial participants were randomised to one of three groups; 4.5 g PGX as softgels (PGXS), 5 g PGX granules (PGXG) or 5 g rice flour (RF) control. Prior to supplementation and at 12 weeks, participants captured before and after images of all food and beverages consumed within 4 days using a mobile food record app (mFR). The mFR images were analysed for food group serving sizes and number of eating occasions. In the PGXG group, intention-to-treat analysis showed there was a significant reduction in waist circumference (2.5 cm; p = 0.003). Subgroup analysis showed that PGXG supplementation at the recommended dose resulted in a reduction in body weight (-1.4 ± 0.10 kg, p < 0.01), body mass index (BMI) reduction (-0.5 ± 0.10, p < 0.01), reduced number of eating occasions (-1.4 ± 1.2, p < 0.01) and a reduced intake of grain food (-1.52 ± 1.84 serves, p = 0.019). PGXG at the recommended dose resulted in a reduction in weight and BMI which was significantly greater than that for RF (p = 0.001). These results demonstrate the potential benefits of PGX fibre in controlling frequency of eating and in weight loss.
Nagura, Kota; Takemoto, Yusa; Moronaga, Satori; Uchida, Yoshiaki; Shimono, Satoshi; Shiino, Akihiko; Tanigaki, Kenji; Amano, Tsukuru; Yoshino, Fumi; Noda, Yohei; Koizumi, Satoshi; Komatsu, Naoki; Kato, Tatsuhisa; Yamauchi, Jun; Tamura, Rui
2017-11-07
With a view to developing a theranostic nanomedicine for targeted drug delivery systems visible by magnetic resonance (MR) imaging, robust metal-free magnetic nanoemulsions (mean particle size less than 20 nm) consisting of a biocompatible surfactant and hydrophobic, low molecular weight 2,2,5-trimethyl-5-(4-alkoxy)phenylpyrrolidine-N-oxyl radicals were prepared in pH 7.4 phosphate-buffered saline (PBS). The structure of the nanoemulsions was characterized by electron paramagnetic resonance spectroscopy, and dynamic light scattering and small-angle neutron-scattering measurements. The nanoemulsions showed high colloidal stability, low cytotoxicity, enough reduction resistance to excess ascorbic acid, and sufficient contrast enhancement in the proton longitudinal relaxation time (T 1 ) weighted MR images in PBS in vitro (and preliminarily in vivo). Furthermore, the hydrophobic anticancer drug paclitaxel could be encapsulated inside the nanoparticles, and the resulting paclitaxel-loaded nanoemulsions were efficiently incorporated into HeLa cells to suppress cell growth. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
Weight reduction in schizophrenics by molindone.
Gardos, G; Cole, J O
1977-03-01
The weight-reducing property of molindone, a recently introduced antipsychotic drug, was tested in 9 hospitalized chronic schizophrenic patients. There was an average weight loss of 7.6 kg after 3 months on molindone; most of the loss occurred during the first month. The mechanism producing this weight loss is uncertain, but a central anorexigenic effect may be an important factor.
USDA-ARS?s Scientific Manuscript database
Depressed individuals are frequently excluded from weight loss trials because of fears that weight reduction may precipitate mood disorders, as well as concerns that depressed participants will not lose weight satisfactorily. The present study examined participants in the Look AHEAD study to determi...
USDA-ARS?s Scientific Manuscript database
Depressed individuals are frequently excluded from weight loss trials because of fears that weight reduction may precipitate mood disorders, as well as concerns that depressed participants will not lose weight satisfactorily. The present study examined participants in the Look AHEAD study to determi...
Keller, Martha; Mustin, Walter
2017-03-01
The Cayman Turtle Farm raises thousands of green sea turtles ( Chelonia mydas ) annually under aquaculture conditions. Historically, the turtles have been raised in tanks without routine access to a shade structure. The purpose of this study was to determine the effects of adding a shade structure on curved carapace length (CCL) and weight gain of green sea turtles. In addition, water and cloacal temperatures were compared across treatment groups and shade cover preferences observed. Ninety turtles were split equally into three treatment groups for this 8-wk study. In the first group turtles were kept in tanks in full sun, the second group in half-shaded tanks, and the third group in tanks completely covered with shade cloth. Time-lapse cameras mounted above half-shaded tanks were used to determine turtle shade structure preferences throughout the day. There were no differences in CCL among treatment groups. Significant increases in weights were noted in turtles kept in full sun and half-shaded tanks versus the fully shaded tanks. Significantly higher water and cloacal turtle temperatures were noted in the full-sun tank compared with the half-shaded or completely shaded tanks. A significantly lower number of turtles was observed in the sun in the half-shaded tanks, indicating a possible preference by turtles for a shade structure. Results suggest that providing shade structures for sea turtles results in a significant decrease in both overall water temperature as well as a reduction in maximum high daily temperatures. Results also suggest that turtles exhibit a preference for shade structures when it is provided as an option. From these results, we recommend that a shade structure be provided when housing green sea turtles in outdoor enclosures.
Cozzarelli, I.M.; Herman, J.S.; Baedecker, M. Jo
1995-01-01
A combined field and laboratory study was undertaken to understand the distribution and geochemical conditions that influence the prevalence of low molecular weight organic acids in groundwater of a shallow aquifer contaminated with gasoline. Aromatic hydrocarbons from gasoline were degraded by microbially mediated oxidation-reduction reactions, including reduction of nitrate, sulfate, and Fe(III). The biogeochemical reactions changed overtime in response to changes in the hydrogeochemical conditions in the aquifer. Aliphatic and aromatic organic acids were associated with hydrocarbon degradation in anoxic zones of the aquifer. Laboratory microcosms demonstrated that the biogeochemical fate of specific organic acids observed in groundwater varied with the structure of the acid and the availability of electron acceptors. Benzoic and phenylacetic acid were degraded by indigenous aquifer microorganisms when nitrate was supplied as an electron acceptor. Aromatic acids with two or more methyl substituants on the benzene ring persisted under nitrate-reducing conditions. Although iron reduction and sulfate reduction were important processes in situ and occurred in the microcosms, these reactions were not coupled to the biological oxidation of aromatic organic acids that were added to the microcosms as electron donors. ?? 1995 American Chemical Society.
Igel, L I; Saunders, K H; Fins, J J
2018-05-21
In this review, we examine one of the ironies of American health care-that we pay more for disease management than disease prevention. Instead of preventing type 2 diabetes (T2DM) by treating its precursor, obesity, we fail to provide sufficient insurance coverage for weight management only to fund the more costly burden of overt T2DM. There is a vital need for expanded insurance coverage to help foster a weight-centric approach to T2DM management. This includes broader coverage of anti-diabetic medications with evidence of cardiovascular risk reduction and mortality benefit, anti-obesity pharmacotherapy, bariatric surgery, weight loss devices, endoscopic bariatric therapies, and lifestyle interventions for the treatment of obesity. The fundamental question to ask is why weight? Why wait to go after obesity until its end-stage sequelae cause intractable conditions? Instead of managing the complications of T2DM, consider preventing them by tackling obesity.
Cuidando El Corazon--a weight-reduction intervention for Mexican Americans.
Foreyt, J P; Ramirez, A G; Cousins, J H
1991-06-01
Cuidando El Corazon (CEC; Taking Care of Your Heart) was designed to assess the effectiveness of a culturally adapted weight-reduction and exercise program for achieving long-term weight loss in Mexican Americans. CEC used a family-oriented approach to achieve lifestyle change in behavior. Participants were assigned to 1) a booklet-only comparison group that received a manual including behavior change, nutrition, and exercise information and traditional recipes modified in fat content; 2) an individual group that received the same manual and attended year-long classes; or 3) a family group that received a manual and attended classes that emphasized techniques for making changes in the family's eating and exercising habits. The family and individual groups had significantly greater weight losses than the information-only group. Weight loss was greatest in the family-involvement group and least in the information-only comparison group.
Model Reduction for Control System Design
NASA Technical Reports Server (NTRS)
Enns, D. F.
1985-01-01
An approach and a technique for effectively obtaining reduced order mathematical models of a given large order model for the purposes of synthesis, analysis and implementation of control systems is developed. This approach involves the use of an error criterion which is the H-infinity norm of a frequency weighted error between the full and reduced order models. The weightings are chosen to take into account the purpose for which the reduced order model is intended. A previously unknown error bound in the H-infinity norm for reduced order models obtained from internally balanced realizations was obtained. This motivated further development of the balancing technique to include the frequency dependent weightings. This resulted in the frequency weighted balanced realization and a new model reduction technique. Two approaches to designing reduced order controllers were developed. The first involves reducing the order of a high order controller with an appropriate weighting. The second involves linear quadratic Gaussian synthesis based on a reduced order model obtained with an appropriate weighting.
NASA Technical Reports Server (NTRS)
Johnson, Joseph L., Jr. (Inventor); White, E. Richard (Inventor)
1986-01-01
This invention is an aircraft with a system for increasing the lift drag ratio over a broad range of operating conditions. The system positions the engines and nacelles over the wing in such a position that gains in propeller efficiency is achieved simultaneously with increases in wing lift and a reduction in wing drag. Adverse structural and torsional effects on the wings are avoided by fuselage mounted pylons which attach to the upper portion of the fuselage aft of the wings. Similarly, pylon-wing interference is eliminated by moving the pylons to the fuselage. Further gains are achieved by locating the pylon surface area aft of the aircraft center of gravity, thereby augmenting both directional and longitudinal stability. This augmentation has the further effect of reducing the size, weight and drag of empennage components. The combination of design changes results in improved cruise performance and increased climb performance while reducing fuel consumption and drag and weight penalties.
Parallel Nonnegative Least Squares Solvers for Model Order Reduction
2016-03-01
NNLS problems that arise when the Energy Conserving Sampling and Weighting hyper -reduction procedure is used when constructing a reduced-order model...ScaLAPACK and performance results are presented. nonnegative least squares, model order reduction, hyper -reduction, Energy Conserving Sampling and...optimal solution. ........................................ 20 Table 6 Reduced mesh sizes produced for each solver in the ECSW hyper -reduction step
Iwahashi, Hiromi; Noguchi, Midori; Okauchi, Yukiyoshi; Morita, Sachiko; Imagawa, Akihisa; Shimomura, Iichiro
2015-01-01
Aims/Introduction Weight reduction improves glycemic control in obese men with glycated hemoglobin (HbA1c) of 5.6–6.4%, suggesting that it can prevent the development of diabetes in these patients. The aim of the present study was to quantify the amount of weight reduction necessary for minimization of diabetes risk in Japanese men with visceral fat accumulation. Materials and Methods The study participants were 482 men with an estimated visceral fat area of ≥100 cm2, HbA1c of 5.6–6.4%, fasting plasma glucose (FPG) of <126 mg/dL or casual plasma glucose <200 mg/dL. They were divided into two groups based on weight change at the end of the 3-year follow-up period (weight gain and weight loss groups). The weight loss group was classified into quartile subgroups (lowest group, 0 to <1.2%: second lowest group, ≥1.2 to <2.5%: second highest group, ≥2.5 to <4.3%: highest group, ≥4.3% weight loss). The development of diabetes at the end-point represented a rise in HbA1c to ≥6.5% or FPG ≥126 mg/dL, or casual plasma glucose ≥200 mg/dL. Results The cumulative incidence of diabetes at the end of the 3-year follow-up period was 16.2% in the weight gain group and 10.1% in the weight loss group (P not significant). The incidence of diabetes was significantly lower in the highest weight loss group (3.1%), but not in the second highest, the second lowest and the lowest weight loss groups (9.7, 10.1 and 18.3%), compared with the weight gain group. Conclusions Minimization of the risk of diabetes in Japanese men with visceral fat accumulation requires a minimum of 4–5% weight loss in those with HbA1c of 5.6–6.4%. PMID:26417413
Jintapattanakit, Anchalee; Mao, Shirui; Kissel, Thomas; Junyaprasert, Varaporn Buraphacheep
2008-10-01
The aim of this research was to investigate the effect of degrees of quaternization (DQ) and dimethylation (DD) on physicochemical properties and cytotoxicity of N-trimethyl chitosan (TMC). TMC was synthesized by reductive methylation of chitosan in the presence of a strong base at elevated temperature and polymer characteristics were investigated. The number of methylation process and duration of reaction were demonstrated to affect the DQ and DD. An increased number of reaction steps increased DQ and decreased DD, while an extended duration of reaction increased both DQ and DD. The molecular weight of TMC was in the range of 60-550kDa. From the Mark-Houwink equation, it was found that TMC in 2% acetic acid/0.2M sodium acetate behaved as a spherical structure, approximating a random coil. The highest solubility was found with TMC of an intermediate DQ (40%) regardless of DD and molecular weight. The effect of DD on the physicochemical properties and cytotoxicity was obviously observed when proportion of DD to DQ was higher than 1. TMC with relatively high DD showed reduction in both solubility and mucoadhesion and hence decreased cytotoxicity. However, the influence of DD was insignificant when DQ of TMC was higher than 40% at which physicochemical properties and cytotoxicity were mainly dependent upon DQ.
NASA Technical Reports Server (NTRS)
King, H. J.
1974-01-01
The basic goal was to advance the development status of the 30-cm electron bombardment ion thruster from a laboratory model to a flight-type engineering model (EM) thruster. This advancement included the more conventional aspects of mechanical design and testing for launch loads, weight reduction, fabrication process development, reliability and quality assurance, and interface definition, as well as a relatively significant improvement in thruster total efficiency. The achievement of this goal was demonstrated by the successful completion of a series of performance and structural integrity (vibration) tests. In the course of the program, essentially every part and feature of the original 30-cm Thruster was critically evaluated. These evaluations, led to new or improved designs for the ion optical system, discharge chamber, cathode isolator vaporizer assembly, main isolator vaporizer assembly, neutralizer assembly, packaging for thermal control, electrical terminations and structure.
Randoux, A; CornilletStoupy, J; Desanti, M; Borel, J P
1976-09-28
Structural glycoproteins have been extracted by 8 M ureau from the insoluble residue remaining after collagenase digestion of rabbit dermis and purified by Sepharose 4 B chromatography. After reduction and alkylation, Dowex 1 x 2 chromatography allowed separation of two structural glycoproteins (D1 and D2) in an homogenous state as shown by chromatographic and electrophoretic behaviour as well as N terminal amino acid determination. These two glycoproteins have a molecular weight of about 16 000. Their amino acid compositions (very similar), are characterized by a high level of dicarboxylic amino acids and the absence of hydroxyproline and hydroxylysine. The less acidic glycoprotein (D1) has glycine for N terminal amino acid and contains 10.4 percent of bound carbohydrates. The glycoprotein D2 contains 5.1 percent of bound carbohydrates and its N terminal amino acid is glutamic acid.
Wurst, E; Möslinger, D; Widhalm, K
1992-01-01
A 12.10-year old boy (actual weight 88.8 kg, actual height 131.2 cm; 228% overweight) with Prader-Willi-syndrome achieved, after repeated ineffective therapy attempts over a period of 10 years, a weight reduction of 11.8 kg (185% overweight) during a 9-week in-patient treatment. In the following out-patient phase of therapy a further weight reduction of 20 kg (109% overweight) was achieved over a period of 16 months. Apart from the usual modes of action of therapy (reduced energy intake, physical exercise, behaviour modification), family therapeutic and special education interventions were used. These achieved an improvement of the patient's self-esteem, an increase in his competence to act and in his autonomy concerning his diet management, as well as a positive experience of his own abilities and social acceptance by other children and the stabilisation of the dysfunctional family system. It may be assumed that this therapeutic success is dependent on consequent compliance with the system model.
Wang, Na; Zhang, Jin-Ping; Xing, Xiao-Yan; Yang, Zhao-Jun; Zhang, Bo; Wang, Xin; Yang, Wen-Ying
2017-08-01
The present post hoc analysis investigated whether changes in endogenous glucagon-like peptide-1 (∆GLP-1) levels are associated with weight loss in newly diagnosed diabetes patients. In all, 784 subjects from the Metformin and AcaRbose in Chinese as initial Hypoglycemic treatment (MARCH) study were stratified according to ∆GLP-1. Changes in clinical and physiological parameters were evaluated across ∆GLP-1 subgroups (low, medium, and high) to assess correlations between ∆GLP-1 and weight loss in acarbose- versus metformin-treated groups. After 24 weeks treatment, greater ∆GLP-1 was associated with significantly greater weight loss (-2 vs -1 kg in the medium/high vs low ∆GLP-1 groups, respectively) and reduction in body mass index (BMI; -0.88, -0.83, and -0.69 kg/m 2 in the high, medium, and low ∆GLP-1 groups, respectively). In the acarbose-treated group, there was a significant association between ∆GLP-1 and BMI reductions, and greater ∆GLP-1 across the high, medium, and low ∆GLP-1 groups was correlated with greater weight loss (-2.8, -2.1, and -1.9 kg, respectively) and reductions in fasting plasma glucose (-1.57, -1.28, and -1.02 mmol/L, respectively) at Week 24. No significant differences were found across ∆GLP-1 subgroups in metformin-treated patients (P > 0.05). Multivariate linear regression analysis revealed that gender, baseline BMI, and ∆GLP-1 at Week 24 were associated with weight loss. Baseline BMI and ∆GLP-1 in the acarbose-treated group and baseline BMI in the metformin-treated group predicted weight loss at Week 24. Changes in GLP-1 levels are associated with weight loss in newly diagnosed Chinese diabetes patients receiving acarbose. © 2016 Ruijin Hospital, Shanghai Jiaotong University School of Medicine and John Wiley & Sons Australia, Ltd.
Abdel-Salam, Wael Nabil; Bekheit, Mohamed; Katri, Khaled; Ezzat, Tarek; El Kayal, El Said
2013-03-01
Abstract Background: The surgical management of morbid obesity is faced by several challenges. Alternative therapeutic strategies could have an important role in the perioperative risk reduction. The BioEnterics(®) intragastric balloon (BIB) (Inamed Health, Santa Barbara, CA) has been described as being effective in weight reduction and is used as a bridge before bariatric surgery. This study examined the efficacy of BIB in obese Egyptian patients and the value of the extended low caloric liquid diet program in weight loss. A retrospective review of a prospectively maintained bariatric database was conducted. Weight changes and complications data were analyzed. Indications for BIB placement were discussed. Records of 55 patients (11 males and 44 females) were retrieved. The mean initial body mass index (BMI) was 45.3±11 kg/m(2). The mean of excess body weight percentage was 111.96±53.2%. Nausea was reported in 30 patients (54.5%). Epigastric discomfort was reported in 23 patients (41.8 %), and vomiting was reported in 27 patients (49.1%). Six patients (10.9%) had an early removal of the balloon, whereas 4 (7.2%) had delayed removal (more than 6 months). The mean excess weight loss percentage (EWL%) was 17.2%. There was significant reduction in patients' BMI from 45.3 to 38.3 kg/m(2) (P<.001). There was no significant correlation between the EWL% and the gender, age, or initial BMI. Two patients had second balloon insertions without complications. There was no significant difference in the EWL% between the 1-week liquid diet group and the extended (4-week) low caloric diet group. The BIB is effective and safe in weight reduction in obese Egyptian patients. The impact of extended liquid dieting period is not significant.
Brown, Tamara J; Todd, Adam; O'Malley, Claire; Moore, Helen J; Husband, Andrew K; Bambra, Clare; Kasim, Adetayo; Sniehotta, Falko F; Steed, Liz; Smith, Sarah; Nield, Lucie; Summerbell, Carolyn D
2016-01-01
Objectives To systematically review the effectiveness of community pharmacy-delivered interventions for alcohol reduction, smoking cessation and weight management. Design Systematic review and meta-analyses. 10 electronic databases were searched from inception to May 2014. Eligibility criteria for selecting studies Study design: randomised and non-randomised controlled trials; controlled before/after studies, interrupted times series. Intervention: any relevant intervention set in a community pharmacy, delivered by the pharmacy team. No restrictions on duration, country, age, or language. Results 19 studies were included: 2 alcohol reduction, 12 smoking cessation and 5 weight management. Study quality rating: 6 ‘strong’, 4 ‘moderate’ and 9 ‘weak’. 8 studies were conducted in the UK, 4 in the USA, 2 in Australia, 1 each in 5 other countries. Evidence from 2 alcohol-reduction interventions was limited. Behavioural support and/or nicotine replacement therapy are effective and cost-effective for smoking cessation: pooled OR was 2.56 (95% CI 1.45 to 4.53) for active intervention vs usual care. Pharmacy-based interventions produced similar weight loss compared with active interventions in other primary care settings; however, weight loss was not sustained longer term in a range of primary care and commercial settings compared with control. Pharmacy-based weight management interventions have similar provider costs to those delivered in other primary care settings, which are greater than those delivered by commercial organisations. Very few studies explored if and how sociodemographic or socioeconomic variables moderated intervention effects. Insufficient information was available to examine relationships between effectiveness and behaviour change strategies, implementation factors, or organisation and delivery of interventions. Conclusions Community pharmacy-delivered interventions are effective for smoking cessation, and demonstrate that the pharmacy is a feasible option for weight management interventions. Given the potential reach, effectiveness and associated costs of these interventions, commissioners should consider using community pharmacies to help deliver public health services. PMID:26928025
NASA Astrophysics Data System (ADS)
Foster, Richard W.
1989-07-01
The application of rocket-based combined cycle (RBCC) engines to booster-stage propulsion, in combination with all-rocket second stages in orbital-ascent missions, has been studied since the mid-1960s; attention is presently given to the case of the 'ejector scramjet' RBCC configuration's application to SSTO vehicles. While total mass delivered to initial orbit is optimized at Mach 20, payload delivery capability to initial orbit optimizes at Mach 17, primarily due to the reduction of hydrogen fuel tankage structure, insulation, and thermal protection system weights.
Spatiotemporal Interpolation for Environmental Modelling
Susanto, Ferry; de Souza, Paulo; He, Jing
2016-01-01
A variation of the reduction-based approach to spatiotemporal interpolation (STI), in which time is treated independently from the spatial dimensions, is proposed in this paper. We reviewed and compared three widely-used spatial interpolation techniques: ordinary kriging, inverse distance weighting and the triangular irregular network. We also proposed a new distribution-based distance weighting (DDW) spatial interpolation method. In this study, we utilised one year of Tasmania’s South Esk Hydrology model developed by CSIRO. Root mean squared error statistical methods were performed for performance evaluations. Our results show that the proposed reduction approach is superior to the extension approach to STI. However, the proposed DDW provides little benefit compared to the conventional inverse distance weighting (IDW) method. We suggest that the improved IDW technique, with the reduction approach used for the temporal dimension, is the optimal combination for large-scale spatiotemporal interpolation within environmental modelling applications. PMID:27509497
Fuel Consumption Reduction and Weight Estimate of an Intercooled-Recuperated Turboprop Engine
NASA Astrophysics Data System (ADS)
Andriani, Roberto; Ghezzi, Umberto; Ingenito, Antonella; Gamma, Fausto
2012-09-01
The introduction of intercooling and regeneration in a gas turbine engine can lead to performance improvement and fuel consumption reduction. Moreover, as first consequence of the saved fuel, also the pollutant emission can be greatly reduced. Turboprop seems to be the most suitable gas turbine engine to be equipped with intercooler and heat recuperator thanks to the relatively small mass flow rate and the small propulsion power fraction due to the exhaust nozzle. However, the extra weight and drag due to the heat exchangers must be carefully considered. An intercooled-recuperated turboprop engine is studied by means of a thermodynamic numeric code that, computing the thermal cycle, simulates the engine behavior at different operating conditions. The main aero engine performances, as specific power and specific fuel consumption, are then evaluated from the cycle analysis. The saved fuel, the pollution reduction, and the engine weight are then estimated for an example case.
Discrete-time model reduction in limited frequency ranges
NASA Technical Reports Server (NTRS)
Horta, Lucas G.; Juang, Jer-Nan; Longman, Richard W.
1991-01-01
A mathematical formulation for model reduction of discrete time systems such that the reduced order model represents the system in a particular frequency range is discussed. The algorithm transforms the full order system into balanced coordinates using frequency weighted discrete controllability and observability grammians. In this form a criterion is derived to guide truncation of states based on their contribution to the frequency range of interest. Minimization of the criterion is accomplished without need for numerical optimization. Balancing requires the computation of discrete frequency weighted grammians. Close form solutions for the computation of frequency weighted grammians are developed. Numerical examples are discussed to demonstrate the algorithm.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Das, S.
2001-01-26
Polymer composite materials have been a part of the automotive industry for several decades, with early application in the 1953 Corvette. These materials have been used for applications with low production volumes, because of their shortened lead times and lower investment costs relative to conventional steel fabrication. Important drivers of the growth of polymer composites have been the reduced weight and parts consolidation opportunities the material offers, as well as design flexibility, corrosion resistance, material anisotropy, and mechanical properties. Although these benefits are well recognized by the industry, polymer composite use has been dampened by high material costs, slow productionmore » rates, and to a lesser extent, concerns about recyclability. Also impeding large scale automotive applications is a curious mixture of concerns about material issues such as crash energy absorption, recycling challenges, competitive and cost pressures, the industry's general lack of experience and comfort with the material, and industry concerns about its own capabilities (Flynn and Belzowski 1995). Polymer composite materials are generally made of two or more material components--fibers, either glass or carbon, reinforced in the matrix of thermoset or thermoplastic polymer materials. The glass-reinforced thermoset composites are the most commonly used composite in automotive applications today, but thermoplastic composites and carbon fiber-reinforced thermosets also hold potential. It has been estimated that significant use of glass-reinforced polymers as structural components could yield a 20-35% reduction in vehicle weight. More importantly, the use of carbon fiber-reinforced materials could yield a 40-65% reduction in weight.« less
Biodegradability of degradable plastic waste.
Agamuthu, P; Faizura, Putri Nadzrul
2005-04-01
Plastic waste constitutes the third largest waste volume in Malaysian municipal solid waste (MSW), next to putrescible waste and paper. The plastic component in MSW from Kuala Lumpur averages 24% (by weight), whereas the national mean is about 15%. The 144 waste dumps in the country receive about 95% of the MSW, including plastic waste. The useful life of the landfills is fast diminishing as the plastic waste stays un-degraded for more than 50 years. In this study the compostability of polyethylene and pro-oxidant additive-based environmentally degradable plastics (EDP) was investigated. Linear low-density polyethylene (LLDPE) samples exposed hydrolytically or oxidatively at 60 degrees C showed that the abiotic degradation path was oxidative rather than hydrolytic. There was a weight loss of 8% and the plastic has been oxidized as shown by the additional carbonyl group exhibited in the Fourier transform infra red (FTIR) Spectrum. Oxidation rate seemed to be influenced by the amount of pro-oxidant additive, the chemical structure and morphology of the plastic samples, and the surface area. Composting studies during a 45-day experiment showed that the percentage elongation (reduction) was 20% for McD samples [high-density polyethylene, (HDPE) with 3% additive] and LL samples (LLDPE with 7% additive) and 18% reduction for totally degradable plastic (TDP) samples (HDPE with 3% additive). Lastly, microbial experiments using Pseudomonas aeroginosa on carbon-free media with degradable plastic samples as the sole carbon source, showed confirmatory results. A positive bacterial growth and a weight loss of 2.2% for degraded polyethylene samples were evident to show that the degradable plastic is biodegradable.
Vadiveloo, M; Parker, H; Raynor, H
2018-01-01
BACKGROUND/OBJECTIVE Although reducing energy density (ED) enhances weight loss, it is unclear whether all dietary strategies that reduce ED are comparable, hindering effective ED guidelines for obesity treatment. This study examined how changes in number of low-energy-dense (LED) (<4.186 kJ/1.0 kcal g−1) and high-energy-dense (HED) (>12.56 kJ/3.0 kcal g−1) foods consumed affected dietary ED and weight loss within an 18-month weight loss trial. METHODS This secondary analysis examined data from participants randomized to an energy-restricted lifestyle intervention or lifestyle intervention plus limited non-nutrient dense, energy-dense food variety (n = 183). Number of daily LED and HED foods consumed was calculated from three, 24-h dietary recalls and anthropometrics were measured at 0, 6 and 18 months. Multivariable-adjusted generalized linear models and repeated-measures mixed linear models examined associations between 6-month changes in number of LED and HED foods and changes in ED, body mass index (BMI), and percent weight loss at 6 and 18 months. RESULTS Among mostly female (58%), White (92%) participants aged 51.9 years following an energy-restricted diet, increasing number of LED foods or decreasing number of HED foods consumed was associated with 6- and 18-month reductions in ED (β = − 0.25 to − 0.38 kJ g−1 (−0.06 to − 0.09 kcal g−1), P<0.001). Only increasing number of LED foods consumed was associated with 6- and 18-month reductions in BMI (β = − 0.16 to − 0.2 kg m−2, P<0.05) and 6-month reductions in percent weight loss (β = − 0.5%, P<0.05). Participants consuming ≤2 HED foods per day and ≥6.6 LED foods per day experienced better weight loss outcomes at 6- and 18-month than participants only consuming ≤2 HED foods per day. CONCLUSION Despite similar reductions in ED from reducing number of HED foods or increasing number of LED foods consumed, only increasing number of LED foods related to weight loss. This provides preliminary evidence that methods used to reduce dietary ED may differentially influence weight loss trajectories. Randomized controlled trials are needed to inform ED recommendations for weight loss. PMID:29406521
Expected effects of reducing Oestrus ovis L. mature larval weight on adult populations.
Cepeda-Palacios, R; Frugère, S; Dorchies, P
2000-06-27
In order to estimate the effects of eventual reductions in larval weight (LW) of Oestrus ovis L. as a measure of control, the correlation between mature LW and adult fly length (AL) in laboratory specimens (n=150) was calculated. The regression equation AL=5.62+10.65LW (r(2)=0.76) was obtained. This equation was then applied to estimate the mature LW of wild larvipositing females (n=51) to predict the minimum mature LW at which fly viability would be compromised. The critical weight, 0.28 g (standard error limits 0. 235, 0.323), was obtained from a small fly measuring 8.6mm in length. Data from 383 mature third instars were used to estimate, by statistical analysis, the expected effects of decreasing the mature LW on subsequent fly population size. A considerable mean reduction (38%) in adult populations might be achieved by a 40% reduction of mature LW, but this eventual reduction may be temporary due to the high reproductive rate in this species. Sex differences in mature LW and fly size are also reported.
Haag, Kim H.; Pfeiffer, William R.
2012-01-01
WAP scores and weighted average scores for wetland vegetation were generally consistent with the results of the flooded area analysis. The WAP scores and weighted average scores were higher overall and did not decline with time at four wetlands in well fields (W-33, W-56, Starkey N, and Starkey 108) during the years following reductions in groundwater-withdrawal rates. These four wetlands also had increases in the extent and duration of the flooded area during the post-reduction period. Scores for trees were more consistent than scores for shrubs and groundcover. WAP scores remained relatively low or generally declined at five well-field wetlands (Q-1, W-17, W-41, Starkey D, and Starkey E) during the years following reductions in groundwater-withdrawal rates, and weighted average scores either declined over time or remained low. These five wetlands either did not have an increase in the extent and duration of the flooded area, or if there was an increase, it was small.
Redman, Leanne M.; Heilbronn, Leonie K.; Martin, Corby K.; de Jonge, Lilian; Williamson, Donald A.; Delany, James P.; Ravussin, Eric
2009-01-01
Background Metabolic and behavioral adaptations to caloric restriction (CR) in free-living conditions have not yet been objectively measured. Methodology and Principal Findings Forty-eight (36.8±1.0 y), overweight (BMI 27.8±0.7 kg/m2) participants were randomized to four groups for 6-months; Control: energy intake at 100% of energy requirements; CR: 25% calorie restriction; CR+EX: 12.5% CR plus 12.5% increase in energy expenditure by structured exercise; LCD: low calorie diet (890 kcal/d) until 15% weight reduction followed by weight maintenance. Body composition (DXA) and total daily energy expenditure (TDEE) over 14-days by doubly labeled water (DLW) and activity related energy activity (AREE) were measured after 3 (M3) and 6 (M6) months of intervention. Weight changes at M6 were −1.0±1.1% (Control), −10.4±0.9% (CR), −10.0±0.8% (CR+EX) and −13.9±0.8% (LCD). At M3, absolute TDEE was significantly reduced in CR (−454±76 kcal/d) and LCD (−633±66 kcal/d) but not in CR+EX or controls. At M6 the reduction in TDEE remained lower than baseline in CR (−316±118 kcal/d) and LCD (−389±124 kcal/d) but reached significance only when CR and LCD were combined (−351±83 kcal/d). In response to caloric restriction (CR/LCD combined), TDEE adjusted for body composition, was significantly lower by −431±51 and −240±83 kcal/d at M3 and M6, respectively, indicating a metabolic adaptation. Likewise, physical activity (TDEE adjusted for sleeping metabolic rate) was significantly reduced from baseline at both time points. For control and CR+EX, adjusted TDEE (body composition or sleeping metabolic rate) was not changed at either M3 or M6. Conclusions For the first time we show that in free-living conditions, CR results in a metabolic adaptation and a behavioral adaptation with decreased physical activity levels. These data also suggest potential mechanisms by which CR causes large inter-individual variability in the rates of weight loss and how exercise may influence weight loss and weight loss maintenance. Trial Registration ClinicalTrials.gov NCT00099151 PMID:19198647
Canuto, Karla; Cargo, Margaret; Li, Ming; D'Onise, Katina; Esterman, Adrian; McDermott, Robyn
2012-10-31
Aboriginal and Torres Strait Islander women experience higher rates of heart disease and type 2 diabetes than non-Indigenous Australian women. Increasing physical activity, improving diets and losing weight have been shown to reduce cardio metabolic risk. The primary aim was to evaluate the effectiveness of a 12-week structured exercise and nutrition program in a cohort of urban Indigenous Australian women on waist circumference, weight and biomedical markers of metabolic functioning from baseline (T1) to program completion (T2). The secondary aim assessed whether these outcomes were maintained at 3-month follow-up. One hundred Aboriginal and/or Torres Strait Islander women aged 18-64 years living in the Adelaide metropolitan area were recruited. The program included two 60-minute group cardiovascular and resistance training classes per week, and four nutrition education workshops. Participants were randomly assigned to an 'active' group or 'waitlisted' control group. Body weight, height, waist and hip circumference, blood pressure, fasting glucose, fasting insulin, glycated haemoglobin (HbA1C), lipid profile and C-reactive protein (CRP) were assessed at baseline (T1), immediately after the program (T2) and three months post program (T3). The active group showed modest reductions in weight and body mass index (BMI). Compared to the waitlisted group, the active group had a statistically significantly change in weight and BMI from baseline assessments; at T2, (-)1.65 kg and (-)0.66 kg/m(2) and at T3, (-)2.50 kg and (-)1.03 kg/m(2), respectively. Systolic and diastolic blood pressure also had a statistically significant difference from baseline in the active group compared to the waitlisted group at T2, (-)1.24 mmHg and (-)2.46 mmHg and at T3, (-)4.09 mmHg and (-)2.17 mmHg, respectively. The findings were independent of the baseline measure of the outcome variable, age, households with children and employment status. Changes in waist circumference and other clinical measures were not significant at T2 or T3. The primary outcome measure, waist circumference, proved problematic to assess reliably. Missing data and participants lost to follow-up were significant. This 12-week exercise program demonstrated modest reductions in weight, BMI and blood pressure at T2, which improved further at 3-month follow-up (T3). Positive intervention effects were observed despite low attendance at exercise classes. Structured exercise programs implemented in community settings require attention to understanding the barriers to participation for this high risk group. Australian New Zealand Clinical Trials Registry ACTRN12610000224022.