Magnetic mass in 4D AdS gravity
NASA Astrophysics Data System (ADS)
Araneda, René; Aros, Rodrigo; Miskovic, Olivera; Olea, Rodrigo
2016-04-01
We provide a fully covariant expression for the diffeomorphic charge in four-dimensional anti-de Sitter gravity, when the Gauss-Bonnet and Pontryagin terms are added to the action. The couplings of these topological invariants are such that the Weyl tensor and its dual appear in the on-shell variation of the action and such that the action is stationary for asymptotic (anti-)self-dual solutions in the Weyl tensor. In analogy with Euclidean electromagnetism, whenever the self-duality condition is global, both the action and the total charge are identically vanishing. Therefore, for such configurations, the magnetic mass equals the Ashtekhar-Magnon-Das definition.
Drag cancellation by added-mass pumping
NASA Astrophysics Data System (ADS)
Giorgio-Serchi, F.; Weymouth, G. D.
2016-07-01
A submerged body subject to a sudden shape-change experiences large forces due to the variation of added-mass energy. While this phenomenon has been studied for single actuation events, application to sustained propulsion requires studying \\textit{periodic} shape-change. We do so in this work by investigating a spring-mass oscillator submerged in quiescent fluid subject to periodic changes in its volume. We develop an analytical model to investigate the relationship between added-mass variation and viscous damping and demonstrate its range of application with fully coupled fluid-solid Navier-Stokes simulations at large Stokes number. Our results demonstrate that the recovery of added-mass kinetic energy can be used to completely cancel the viscous damping of the fluid, driving the onset of sustained oscillations with amplitudes as large as four times the average body radius $r_0$. A quasi-linear relationship is found to link the terminal amplitude of the oscillations $X$, to the extent of size change $a$, with $X/a$ peaking at values from 4 to 4.75 depending on the details of the shape-change kinematics. In addition, it is found that pumping in the frequency range of $1-\\frac{a}{2r_0}<\\omega^2/\\omega_n^2<1+\\frac{a}{2r_0}$ is required for sustained oscillations. The results of this analysis shed light on the role of added-mass recovery in the context of shape-changing bodies and biologically-inspired underwater vehicles.
Conformal mass in Einstein-Gauss-Bonnet AdS gravity
NASA Astrophysics Data System (ADS)
Jatkar, Dileep P.; Kofinas, Georgios; Miskovic, Olivera; Olea, Rodrigo
2015-05-01
In this paper, we show that the physical information given by conserved charges for asymptotically AdS spacetimes in Einstein-Gauss-Bonnet AdS gravity is encoded in the electric part of the Weyl tensor. This result generalizes the conformal mass definition by Ashtekar-Magnon-Das (AMD) to a gravity theory with a Gauss-Bonnet term. This proof makes use of the Noether charges obtained from an action renormalized by the addition of counterterms which depend on the extrinsic curvature (Kounterterms). If the asymptotic fall-off behavior of the Weyl tensor is same as the one considered in the AMD method, then the Kounterterm charges and the AMD charges agree in any dimension.
Added mass and critical mass in vortex induced vibration
NASA Astrophysics Data System (ADS)
Konstantinidis, Efstathios
2015-11-01
The critical mass phenomenon is the observation that a circular cylinder suspended freely in a fluid stream without a mechanical restoring force exhibits significant vortex induced vibration if its mass is below some value whereas insignificant vibration occurs if the mass is above this value. While the phenomenon is known, its origin remains largely unknown. Furthermore, there are several outstanding questions regarding this phenomenon which cannot be explained on the basis of the existing theoretical framework. In this work, a new formulation of the added mass in the context of potential flow is presented. This leads to a new expression for the potential force, which is more complex than the classical one, that is subsequently employed in simplified form in order to analytically model the flow-structure interaction by decomposing the fluid force into potential and vortex components via the equation of cylinder motion. It is found that the model predicts a significant increase in the amplitude response of a freely suspended cylinder in sharp contrast to predictions using the classical formulation of the added mass. Finally, the model equations are employed to exemplify the phenomenology of the critical mass in real flows.
Proposed Framework for Determining Added Mass of Orion Drogue Parachutes
NASA Technical Reports Server (NTRS)
Fraire, Usbaldo, Jr.; Dearman, James; Morris, Aaron
2011-01-01
The Crew Exploration Vehicle (CEV) Parachute Assembly System (CPAS) project is executing a program to qualify a parachute system for a next generation human spacecraft. Part of the qualification process involves predicting parachute riser tension during system descent with flight simulations. Human rating the CPAS hardware requires a high degree of confidence in the simulation models used to predict parachute loads. However, uncertainty exists in the heritage added mass models used for loads predictions due to a lack of supporting documentation and data. Even though CPAS anchors flight simulation loads predictions to flight tests, extrapolation of these models outside the test regime carries the risk of producing non-bounding loads. A set of equations based on empirically derived functions of skirt radius is recommended as the simplest and most viable method to test and derive an enhanced added mass model for an inflating parachute. This will increase confidence in the capability to predict parachute loads. The selected equations are based on those published in A Simplified Dynamic Model of Parachute Inflation by Dean Wolf. An Ames 80x120 wind tunnel test campaign is recommended to acquire the reefing line tension and canopy photogrammetric data needed to quantify the terms in the Wolf equations and reduce uncertainties in parachute loads predictions. Once the campaign is completed, the Wolf equations can be used to predict loads in a typical CPAS Drogue Flight test. Comprehensive descriptions of added mass test techniques from the Apollo Era to the current CPAS project are included for reference.
Short-term memory binding is impaired in AD but not in non-AD dementias.
Della Sala, Sergio; Parra, Mario A; Fabi, Katia; Luzzi, Simona; Abrahams, Sharon
2012-04-01
Binding is a cognitive function responsible for integrating features within complex stimuli (e.g., shape-colour conjunctions) or events within complex memories (e.g., face-name associations). This function operates both in short-term memory (STM) and in long-term memory (LTM) and is severely affected by Alzheimer's disease (AD). However, forming conjunctions in STM is the only binding function which is not affected by healthy ageing or chronic depression. Whether this specificity holds true across other non-AD dementias is as yet unknown. The present study investigated STM conjunctive binding in a sample of AD patients and patients with other non-AD dementias using a task which has proved sensitive to the effects of AD. The STM task assesses the free recall of objects, colours, and the bindings of objects and colours. Patients with AD, frontotemporal dementia, vascular dementia, lewy body dementia and dementia associated with Parkinson's disease showed memory, visuo-spatial, executive and attentional deficits on standard neuropsychological assessment. However, only AD patients showed STM binding deficits. This deficit was observed even when memory for single features was at a similar level across patient groups. Regression and discriminant analyses confirmed that the STM binding task accounted for the largest proportion of variance between AD and non-AD groups and held the greatest classification power to identify patients with AD. STM conjunctive binding places little demands on executive functions and appears to be subserved by components of the memory network which are targeted by AD, but not by non-AD dementias. PMID:22289292
Metabolic rate of carrying added mass: a function of walking speed, carried mass and mass location.
Schertzer, Eliran; Riemer, Raziel
2014-11-01
The effort of carrying additional mass at different body locations is important in ergonomics and in designing wearable robotics. We investigate the metabolic rate of carrying a load as a function of its mass, its location on the body and the subject's walking speed. Novel metabolic rate prediction equations for walking while carrying loads at the ankle, knees and back were developed based on experiments where subjects walked on a treadmill at 4, 5 or 6km/h bearing different amounts of added mass (up to 2kg per leg and 22kg for back). Compared to previously reported equations, ours are 7-69% more accurate. Results also show that relative cost for carrying a mass at a distal versus a proximal location changes with speed and mass. Contrary to mass carried on the back, mass attached to the leg cannot be modeled as an increase in body mass. PMID:24793822
Added Value of Assessing Adnexal Masses with Advanced MRI Techniques
Thomassin-Naggara, I.; Balvay, D.; Rockall, A.; Carette, M. F.; Ballester, M.; Darai, E.; Bazot, M.
2015-01-01
This review will present the added value of perfusion and diffusion MR sequences to characterize adnexal masses. These two functional MR techniques are readily available in routine clinical practice. We will describe the acquisition parameters and a method of analysis to optimize their added value compared with conventional images. We will then propose a model of interpretation that combines the anatomical and morphological information from conventional MRI sequences with the functional information provided by perfusion and diffusion weighted sequences. PMID:26413542
Higgs mechanism and the added-mass effect
Krishnaswami, Govind S.; Phatak, Sachin S.
2015-01-01
In the Higgs mechanism, mediators of the weak force acquire masses by interacting with the Higgs condensate, leading to a vector boson mass matrix. On the other hand, a rigid body accelerated through an inviscid, incompressible and irrotational fluid feels an opposing force linearly related to its acceleration, via an added-mass tensor. We uncover a striking physical analogy between the two effects and propose a dictionary relating them. The correspondence turns the gauge Lie algebra into the space of directions in which the body can move, encodes the pattern of gauge symmetry breaking in the shape of an associated body and relates symmetries of the body to those of the scalar vacuum manifold. The new viewpoint is illustrated with numerous examples, and raises interesting questions, notably on the fluid analogues of the broken symmetry and Higgs particle, and the field-theoretic analogue of the added mass of a composite body.
Calculation of the added mass of a liquid tank's bulkheads
NASA Astrophysics Data System (ADS)
Zhu, Junkai; Lin, Zhe; Liu, Qiang; Zhang, Lihua
2014-03-01
The added mass coefficient and the water level index formulas for the same-phase and anti-phase vibration of rectangular liquid tanks' bulkheads were derived based on dry mode theory. Three fluid-structure interaction numerical methods including Fluid FEM and Fluid BEM were used in this case. The comparison of numerical and theoretical results by the present method shows that ANSYS/Fluid80 is more credible, the NASTRAN/Virtual Mass Method is more suitable for engineering calculations and results of the same-phase vibration by the present method is more accurate.
Masses of higher spin fields on AdS4 and conformal perturbation theory
NASA Astrophysics Data System (ADS)
Hikida, Yasuaki
2016-07-01
We study the breaking of gauge symmetry for higher spin theory on AdS4 dual to the 3d critical O (N ) vector model. It was argued that the breaking is due to the change of boundary condition for a scalar field through a loop effect and the Goldstone modes are bound states of a scalar field and higher spin field. The masses of higher spin fields were obtained from the anomalous dimensions of dual currents at the leading order in 1 /N , and we reproduce them from the O (N ) vector model in the conformal perturbation theory. The anomalous dimensions can be computed from the bulk theory using Witten diagrams, and we show that the bulk computation reduces to the boundary one in the conformal perturbation theory. With this fact our computation provides an additional support for the bulk interpretation.
Surface term effects on mass estimators
NASA Astrophysics Data System (ADS)
Membrado, M.; Pacheco, A. F.
2016-05-01
Context. We propose a way of estimating the mass contained in the volume occupied by a sample of galaxies in a virialized system. Aims: We analyze the influence of surface effects and the contribution of the cosmological constant terms on our mass estimations of galaxy systems. Methods: We propose two equations that contain surface terms to estimate galaxy sample masses. When the surface terms are neglected, these equations provide the so-called virial and projected masses. Both equations lead to a single equation that allows sample masses to be estimated without the need for calculating surface terms. Sample masses for some nearest galaxy groups are estimated and compared with virialized masses determined from turn-around radii and results of a spherical infall model. Results: Surface effects have a considerable effect on the mass estimations of the studied galaxy groups. According to our results, they lead sample masses of some groups to being less than half the virial mass estimations and even less than 10% of projected mass estimations. However, the contributions of cosmological constant terms to mass estimations are smaller than 2% for the majority of the virialized groups studied. Our estimations are in agreement with virialized masses calculated from turn-around radii. Virialized masses for complexes were found to be: (8.9 ± 2.8) × 1011 M⊙ for the Milky Way - M 31; (12.5 ± 2.5) × 1011 M⊙ for M 81 - NGC 2403; (21.5 ± 7.7) × 1011 M⊙. for Cantaurs A - M 83; and (7.9 ± 2.6) × 1011 M⊙. for IC 324 - Maffei. Conclusions: The nearest galaxy groups located inside a sphere of 5 Mpc have been addressed to explore the performance of our mass estimator. We have seen that surface effects make mass estimations of galaxy groups rather smaller than both virial and projected masses. In mass calculations, cosmological constant terms can be neglected; nevertheless, the collapse of cold dark matter leading to virialized structures is strongly affected by the
Changes in Gait with Anteriorly Added Mass: A Pregnancy Simulation Study.
Ogamba, Maureen I; Loverro, Kari L; Laudicina, Natalie M; Gill, Simone V; Lewis, Cara L
2016-08-01
During pregnancy, the female body experiences structural changes, such as weight gain. As pregnancy advances, most of the additional mass is concentrated anteriorly on the lower trunk. The purpose of this study is to analyze kinematic and kinetic changes when load is added anteriorly to the trunk, simulating a physical change experienced during pregnancy. Twenty healthy females walked on a treadmill while wearing a custom made pseudo-pregnancy sac (1 kg) under 3 load conditions: sac-only condition, 10-lb condition (4.535 kg added anteriorly), and 20-lb condition (9.07 kg added anteriorly), used to simulate pregnancy in the second trimester and at full-term pregnancy, respectively. The increase in anterior mass resulted in kinematic changes at the knee, hip, pelvis, and trunk in the sagittal and frontal planes. In addition, ankle, knee, and hip joint moments normalized to baseline mass increased with increased load; however, these moments decreased when normalized to total mass. These kinematic and kinetic changes may suggest that women modify gait biomechanics to reduce the effect of added load. Furthermore, the increase in joint moments increases stress on the musculoskeletal system and may contribute to musculoskeletal pain. PMID:26958743
Massless Lüscher terms and the limitations of the AdS3 asymptotic Bethe ansatz
NASA Astrophysics Data System (ADS)
Abbott, Michael C.; Aniceto, Inês
2016-05-01
In AdS5/CFT4 integrability the Bethe ansatz gives the spectrum of long strings, accurate up to exponentially small corrections. This is no longer true in three-dimensional anti-de Sitter (AdS3 ) space, as we demonstrate here by studying Lüscher F-terms with a massless particle running in the loop. We apply this to the classic test of Hernández and López, in which the s u (2 ) sector Bethe equations (including the one-loop dressing phase) should match the semiclassical string theory result for a circular spinning string. These calculations do not agree in AdS3×S3×T4 , and we show that the sum of all massless Lüscher F-terms can reproduce the difference.
Meson effective mass in the isospin medium in hard-wall AdS/QCD model
NASA Astrophysics Data System (ADS)
Mamedov, Shahin
2016-02-01
We study a mass splitting of the light vector, axial-vector, and pseudoscalar mesons in the isospin medium in the framework of the hard-wall model. We write an effective mass definition for the interacting gauge fields and scalar field introduced in gauge field theory in the bulk of AdS space-time. Relying on holographic duality we obtain a formula for the effective mass of a boundary meson in terms of derivative operator over the extra bulk coordinate. The effective mass found in this way coincides with the one obtained from finding of poles of the two-point correlation function. In order to avoid introducing distinguished infrared boundaries in the quantization formula for the different mesons from the same isotriplet we introduce extra action terms at this boundary, which reduces distinguished values of this boundary to the same value. Profile function solutions and effective mass expressions were found for the in-medium ρ , a_1, and π mesons.
29 CFR 1912.11 - Terms of ad hoc committee members.
Code of Federal Regulations, 2010 CFR
2010-07-01
... 29 Labor 7 2010-07-01 2010-07-01 false Terms of ad hoc committee members. 1912.11 Section 1912.11..., DEPARTMENT OF LABOR (CONTINUED) ADVISORY COMMITTEES ON STANDARDS Organizational Matters § 1912.11 Terms of ad hoc committee members. Each member of an ad hoc advisory committee shall serve for such period as...
29 CFR 1912.11 - Terms of ad hoc committee members.
Code of Federal Regulations, 2013 CFR
2013-07-01
... 29 Labor 7 2013-07-01 2013-07-01 false Terms of ad hoc committee members. 1912.11 Section 1912.11..., DEPARTMENT OF LABOR (CONTINUED) ADVISORY COMMITTEES ON STANDARDS Organizational Matters § 1912.11 Terms of ad hoc committee members. Each member of an ad hoc advisory committee shall serve for such period as...
29 CFR 1912.11 - Terms of ad hoc committee members.
Code of Federal Regulations, 2012 CFR
2012-07-01
... 29 Labor 7 2012-07-01 2012-07-01 false Terms of ad hoc committee members. 1912.11 Section 1912.11..., DEPARTMENT OF LABOR (CONTINUED) ADVISORY COMMITTEES ON STANDARDS Organizational Matters § 1912.11 Terms of ad hoc committee members. Each member of an ad hoc advisory committee shall serve for such period as...
29 CFR 1912.11 - Terms of ad hoc committee members.
Code of Federal Regulations, 2014 CFR
2014-07-01
... 29 Labor 7 2014-07-01 2014-07-01 false Terms of ad hoc committee members. 1912.11 Section 1912.11..., DEPARTMENT OF LABOR (CONTINUED) ADVISORY COMMITTEES ON STANDARDS Organizational Matters § 1912.11 Terms of ad hoc committee members. Each member of an ad hoc advisory committee shall serve for such period as...
29 CFR 1912.11 - Terms of ad hoc committee members.
Code of Federal Regulations, 2011 CFR
2011-07-01
... 29 Labor 7 2011-07-01 2011-07-01 false Terms of ad hoc committee members. 1912.11 Section 1912.11..., DEPARTMENT OF LABOR (CONTINUED) ADVISORY COMMITTEES ON STANDARDS Organizational Matters § 1912.11 Terms of ad hoc committee members. Each member of an ad hoc advisory committee shall serve for such period as...
Added mass matrix estimation of beams partially immersed in water using measured dynamic responses
NASA Astrophysics Data System (ADS)
Liu, Fushun; Li, Huajun; Qin, Hongde; Liang, Bingchen
2014-09-01
An added mass matrix estimation method for beams partially immersed in water is proposed that employs dynamic responses, which are measured when the structure is in water and in air. Discrepancies such as mass and stiffness matrices between the finite element model (FEM) and real structure could be separated from the added mass of water by a series of correction factors, which means that the mass and stiffness of the FEM and the added mass of water could be estimated simultaneously. Compared with traditional methods, the estimated added mass correction factors of our approach will not be limited to be constant when FEM or the environment of the structure changed, meaning that the proposed method could reflect the influence of changes such as water depth, current, and so on. The greatest improvement is that the proposed method could estimate added mass of water without involving any water-related assumptions because all water influences are reflected in measured dynamic responses of the structure in water. A five degrees-of-freedom (dofs) mass-spring system is used to study the performance of the proposed scheme. The numerical results indicate that mass, stiffness, and added mass correction factors could be estimated accurately when noise-free measurements are used. Even when the first two modes are measured under the 5 percent corruption level, the added mass could be estimated properly. A steel cantilever beam with a rectangular section in a water tank at Ocean University of China was also employed to study the added mass influence on modal parameter identification and to investigate the performance of the proposed method. The experimental results demonstrated that the first two modal frequencies and mode shapes of the updated model match well with the measured values by combining the estimated added mass in the initial FEM.
Small neutrino masses from gravitational θ -term
NASA Astrophysics Data System (ADS)
Dvali, Gia; Funcke, Lena
2016-06-01
We present how a neutrino condensate and small neutrino masses emerge from a topological formulation of gravitational anomaly. We first recapitulate how a gravitational θ -term leads to the emergence of a new bound neutrino state analogous to the η' meson of QCD. Then we show the consequent formation of a neutrino vacuum condensate, which effectively generates small neutrino masses. Afterwards we outline numerous phenomenological consequences of our neutrino mass generation model. The cosmological neutrino mass bound vanishes since we predict the neutrinos to be massless until the phase transition in the late Universe, T ˜meV . Coherent radiation of new light particles in the neutrino sector can be detected in prospective precision experiments. Deviations from an equal flavor rate due to enhanced neutrino decays in extraterrestrial neutrino fluxes can be observed in future IceCube data. These neutrino decays may also necessitate modified analyses of the original neutrino spectra of the supernova SN 1987A. The current cosmological neutrino background only consists of the lightest neutrinos, which, due to enhanced neutrino-neutrino interactions, either bind up, form a superfluid, or completely annihilate into massless bosons. Strongly coupled relic neutrinos could provide a contribution to cold dark matter in the late Universe, together with the new proposed particles and topological defects, which may have formed during neutrino condensation. These enhanced interactions could also be a source of relic neutrino clustering in our Galaxy, which possibly makes the overdense cosmic neutrino background detectable in the KATRIN experiment. The neutrino condensate provides a mass for the hypothetical B -L gauge boson, leading to a gravity-competing force detectable in short-distance measurements. Prospective measurements of the polarization intensities of gravitational waves can falsify our neutrino mass generation model.
A Lean Neck Mass Clinic Model: Adding Value to Care
Tillman, Brittny N.; Glazer, Tiffany A.; Ray, Amrita; Brenner, J. Chad; Spector, Matthew E.
2016-01-01
Objective To demonstrate that ultrasound guided fine needle aspiration (USFNA) with on-site cytopathologic analysis eliminates unnecessary diagnostic testing, return visits, repeat procedures and optimizes quality of care. Study Design Retrospective Cohort Methods 61 new patients (28 female; 33 male; age range 19-85) were seen in our dedicated neck mass clinic over a one-year period. All patients underwent USFNA of masses located in neck levels I-VI (40), parotid gland (20), or parapharyngeal space (1). Each patient underwent two USFNA passes followed by on-site cytopathologic analysis with additional passes if required for diagnosis. Results Diagnosis was made in 93.4% (57) of patients allowing for counseling and treatment planning at the first visit. In order to obtain a diagnosis, more than half (57.4%, 35) of our patients required additional passes which implies that they would have required an additional visit without on-site cytopathologic analysis. Treatment included: Observation in 42.6% (26) of patients, surgery in 32.8 % (20) of patients and nonsurgical treatment (chemotherapy, radiation, other) in 24.6% (15) of patients. The average time from check-in to checkout including the clinic visit, biopsy and treatment counseling was 103 minutes, and the average round trip mileage traveled per patient was 127.6 miles. Conclusion The adult neck mass is a commonly encountered scenario in otolaryngology. For the patient this can be a stressful situation in which timely and accurate diagnosis is critical. A dedicated lean neck mass clinic model with USFNA and on-site cytopathologic analysis can be both an efficient part of one's practice and a valuable addition to patient care. PMID:26256915
Experimental investigation of added mass effects on a hydrofoil under cavitation conditions
NASA Astrophysics Data System (ADS)
De La Torre, O.; Escaler, X.; Egusquiza, E.; Farhat, M.
2013-05-01
The influence of leading edge sheet cavitation and supercavitation on the added mass effects experienced by a 2-D NACA0009 truncated hydrofoil has been experimentally investigated in a hydrodynamic tunnel. A non-intrusive excitation and measuring system based on piezoelectric patches mounted on the hydrofoil surface was used to determine the natural frequencies of the fluid-structure system. The appropriate hydrodynamic conditions were selected to generate a range of stable partial cavities of various sizes and also to minimize the effects of other sources of flow noise and vibrations. The main tests were performed for different sigma values under a constant flow velocity of 14m/s and for incident angles of both 1° and 2°. Additionally, a series of experiments in which the hydrofoil was submerged in air, partially and completely submerged in still water and without cavitation at 7 and 14m/s were also performed. The maximum added mass effect occurs with still water. When cavitation appears, the added mass decreases because the cavity length is increased, and the added mass is minimum for supercavitation. A linear correlation is found between the added mass coefficients and the entrained mass that accounts for the mean density of the cavity, its dimensions and its location relative to the specific mode shape deformation.
The Use of Stereotypes in Mass Media Advertising: Blacks in Magazine, Newspaper and Television Ads.
ERIC Educational Resources Information Center
Culley, James D.; Bennett, Rex
A brief review of the literature on the use of black stereotypes in mass media advertising, and the results of a current study in this area are presented. Data were gathered by analysis of 1,536 ads in six general interest magazines and 4,371 ads in the New York Times over a one month period, and 368 television commercials on three networks over a…
A note on physical mass and the thermodynamics of AdS-Kerr black holes
NASA Astrophysics Data System (ADS)
McInnes, Brett; Ong, Yen Chin
2015-11-01
As with any black hole, asymptotically anti-de Sitter Kerr black holes are described by a small number of parameters, including a ``mass parameter'' M that reduces to the AdS-Schwarzschild mass in the limit of vanishing angular momentum. In sharp contrast to the asymptotically flat case, the horizon area of such a black hole increases with the angular momentum parameter a if one fixes M; this appears to mean that the Penrose process in this case would violate the Second Law of black hole thermodynamics. We show that the correct procedure is to fix not M but rather the ``physical'' mass E=M/(1-a2/L2)2 this is motivated by the First Law. For then the horizon area decreases with a. We recommend that E always be used as the mass in physical processes: for example, in attempts to ``over-spin'' AdS-Kerr black holes.
He, Qing Mao, Xinhua Chu, Dongliang
2015-07-15
This study proposes an optimized frequency adjustment method that uses a micro-cantilever beam-based piezoelectric vibration generator based on a combination of added mass and capacitance. The most important concept of the proposed method is that the frequency adjustment process is divided into two steps: the first is a rough adjustment step that changes the size of the mass added at the end of cantilever to adjust the frequency in a large-scale and discontinuous manner; the second step is a continuous but short-range frequency adjustment via the adjustable added capacitance. Experimental results show that when the initial natural frequency of a micro piezoelectric vibration generator is 69.8 Hz, then this natural frequency can be adjusted to any value in the range from 54.2 Hz to 42.1 Hz using the combination of the added mass and the capacitance. This method simply and effectively matches a piezoelectric vibration generator’s natural frequency to the vibration source frequency.
Long-term variations in natural, terrestrial VOC emissions: 1000-1990 AD
NASA Astrophysics Data System (ADS)
Acosta, J. C.; Struthers, H.; Zorita, E.; Ekman, A. M.; Riipinen, I.
2012-12-01
). We evaluate the long-term response of terrestrial BVOC emission activity to variations in land-use change and climatic factors, and find that compared to preindustrial times (1000-1800 A.D.), global isoprene emissions have decreased 8%, monoterpenes emissions have increased 10% and sesquiterpenes emissions have increased 15% during the time period 1950-1990 A.D.. The results suggest that the variation of isoprene emissions is governed by land-use changes, while monoterpenenes and sesquiterpenes variations are dominated by climate variability. Adams, J.M. (2001). Chemosphere - Global Change Science, 3, 73-91 J.H. Seinfeld and S. N. Pandis. (1998). Atmospheric Chemistry and Physics . Wiley, New York Jimenez, J. L. et al. (2009). Science, 326, 1525-1529 Kaplan, J. O. et al (2010). The Holocene 21(5), 775-791 Guenther, A. et al. (1995). J. Geophys. Res., 100, 8873-8892 Hoyle, C. R. et al. (2011). Atmos. Chem. Phys., 11, 321-343 A. Guenther et al. (2006). Atmospheric Chemistry and Physics, 6:3181-3210 J. H. Jungclaus et al. (2010). Climate of the Past, 6:723-737
Experimental investigation of added mass effects on a Francis turbine runner in still water
NASA Astrophysics Data System (ADS)
Rodriguez, C. G.; Egusquiza, E.; Escaler, X.; Liang, Q. W.; Avellan, F.
2006-07-01
The mechanical design of hydraulic turbines is conditioned by the dynamic response of the runner that is usually estimated by a computational model. Nevertheless, the runner has complex boundary conditions that are difficult to include in the computational model. One of these boundary conditions is the water in which the runner is submerged. The effect of the added mass and damping of water can modify considerably the natural frequencies of the runner. An experimental investigation in a reduced scale model of a turbine runner, using modal analysis, was carried out. Several impact tests with the runner freely suspended in air and in water were done. The response was measured with accelerometers located in different positions of the runner. From the modal analysis, the natural frequencies, damping ratios, and mode-shapes were determined. The same mode-shapes obtained in air were obtained in water but with lower natural frequencies and higher damping ratios in water. The difference in the natural frequencies is shown to be dependant basically on the added mass effect of the water and not on its added damping. This difference also depends on the geometry of the mode, presenting different values for different mode-shapes. Using nondimensional values, the reduction in the natural frequencies can be extrapolated to other Francis runners presenting similar geometrical characteristics.
NASA Astrophysics Data System (ADS)
Bumberger, Jan; Mollenhauer, Hannes; Lapteva, Yulia; Hutschenreuther, Tino; Toepfer, Hannes; Dietrich, Peter
2014-05-01
To characterize environmental systems it is necessary to identify and describe processes with suitable methods. Environmental systems are often characterized by their high heterogeneity, so individual measurements for their complete representation are often not sufficient. The application of wireless sensor networks in terrestrial and aquatic ecosystems offer significant benefits as a better consideration of the local test conditions becomes possible. This can be essential for the monitoring of heterogeneous environmental systems. Significant advantages in the application of mobile ad-hoc wireless sensor networks are their self-organizing behavior, resulting in a major reduction in installation and operation costs and time. In addition, a point measurement with a sensor is significantly improved by measuring at several points. It is also possible to perform analog and digital signal processing and computation on the basis of the measured data close to the sensor. Hence, a significant reduction of the data to be transmitted can be achieved which leads to a better energy management of sensor nodes. Furthermore, their localization via satellite, the miniaturization of the nodes and long-term energy self-sufficiency are current topics under investigation. The possibilities and limitations of the applicability of wireless sensor networks for long-term and mobile environmental monitoring are presented. A concepts and realization example are given in the field of micrometeorology and soil parameters for the interaction of biotic and abiotic processes .This long term monitoring is part of the Global Change Experimental Facility (GCEF), a large field-based experimental platform to assess the effects of climate change on ecosystem functions and processes under different land-use scenarios. Furthermore a mobile ad-hoc sensor network is presented for the monitoring of water induced mass wasting processes.
Piñeirua, M; Godoy-Diana, R; Thiria, B
2015-08-01
In this Rapid Communication, we address a crucial point regarding the description of moderate to high Reynolds numbers aquatic swimmers. For decades, swimming animals have been classified in two different families of propulsive mechanisms based on the Reynolds number: the resistive swimmers, using local friction to produce the necessary thrust force for locomotion at low Reynolds number, and the reactive swimmers, lying in the high Reynolds range, and using added mass acceleration (described by perfect fluid theory). However, inertial swimmers are also systems that dissipate energy, due to their finite size, therefore involving strong resistive contributions, even for high Reynolds numbers. Using a complete model for the hydrodynamic forces, involving both reactive and resistive contributions, we revisit here the physical mechanisms responsible for the thrust production of such swimmers. We show, for instance, that the resistive part of the force balance is as crucial as added mass effects in the modeling of the thrust force, especially for elongated species. The conclusions brought by this work may have significant contributions to the understanding of complex swimming mechanisms, especially for the future design of artificial swimmers. PMID:26382334
NASA Astrophysics Data System (ADS)
Piñeirua, M.; Godoy-Diana, R.; Thiria, B.
2015-08-01
In this Rapid Communication, we address a crucial point regarding the description of moderate to high Reynolds numbers aquatic swimmers. For decades, swimming animals have been classified in two different families of propulsive mechanisms based on the Reynolds number: the resistive swimmers, using local friction to produce the necessary thrust force for locomotion at low Reynolds number, and the reactive swimmers, lying in the high Reynolds range, and using added mass acceleration (described by perfect fluid theory). However, inertial swimmers are also systems that dissipate energy, due to their finite size, therefore involving strong resistive contributions, even for high Reynolds numbers. Using a complete model for the hydrodynamic forces, involving both reactive and resistive contributions, we revisit here the physical mechanisms responsible for the thrust production of such swimmers. We show, for instance, that the resistive part of the force balance is as crucial as added mass effects in the modeling of the thrust force, especially for elongated species. The conclusions brought by this work may have significant contributions to the understanding of complex swimming mechanisms, especially for the future design of artificial swimmers.
Long-Term Fluctuations in the Earth's Rotation: 700 BC to AD 1990
NASA Astrophysics Data System (ADS)
Stephenson, F. R.; Morrison, L. V.
1995-04-01
Records of solar and lunar eclipses in the period 700 BC to AD 1600, originating from the ancient and medieval civilizations of Babylon, China, Europe and the Arab world, are amassed and critically appraised for their usefulness in answering questions about the long-term variability of the Earth's rate of rotation. Results from previous analyses of lunar occultations in the period AD 1600-1955.5, and from high-precision data in AD 1955.5-1990, are included in the dataset considered in this paper. Using the change in the length of the mean solar day (l.o.d.) in units of milliseconds per century (ms cy-1) as the measure of acceleration in the rate of rotation, it is found that the l.o.d. has increased by (+1.70 ± 0.05) ms cy-1 (equiv (-4.5 ± 0.1) × 10-22 rad s-2) on average over the past 2700 years. Yet an increase of +2.3 ± 0.1 ms cy-1 (equiv (-6.1 ± 0.4) × 10-22 rad s-2) is expected from the tidal braking of the Earth's spin, assuming a value of -26.0' ' cy-2 for the tidal acceleration of the Moon. There is thus an average accelerative component in the Earth's rotation which acts to decrease the l.o.d. by (-0.6 ± 0.1) ms cy-1 (equiv (+1.6 ± 0.4) × 10-22 rad s-2). Moreover, it is shown that besides this accelerative component, there is a fluctuation in the l.o.d. with a semi-amplitude of ~ 4 ms and a period of ~ 1500 yr.
Deuteron as a Skyrmion with a generalized mass term
Bonenfant, Eric; Marleau, Luc
2009-12-01
We calculate the energies of the B=1 and B=2 Skyrmions with a generalized mass term proposed in [V. B. Kopeliovich, B. Piette, and W. J. Zakrzewski, Phys. Rev. D 73, 014006 (2006).], allowing for (iso-)rotational deformations within the axially-symmetric ansatz. We show that this modification of the chiral symmetry breaking term is not sufficient to accommodate for the experimental value of the binding energy of the deuteron. Also, a computation of the different vibrational modes and energies reveals how the deuteron rigidity is affected as a function of the mass parameter D.
Spatial and temporal distribution of mass loss from the Greenland Ice Sheet since AD 1900.
Kjeldsen, Kristian K; Korsgaard, Niels J; Bjørk, Anders A; Khan, Shfaqat A; Box, Jason E; Funder, Svend; Larsen, Nicolaj K; Bamber, Jonathan L; Colgan, William; van den Broeke, Michiel; Siggaard-Andersen, Marie-Louise; Nuth, Christopher; Schomacker, Anders; Andresen, Camilla S; Willerslev, Eske; Kjær, Kurt H
2015-12-17
The response of the Greenland Ice Sheet (GIS) to changes in temperature during the twentieth century remains contentious, largely owing to difficulties in estimating the spatial and temporal distribution of ice mass changes before 1992, when Greenland-wide observations first became available. The only previous estimates of change during the twentieth century are based on empirical modelling and energy balance modelling. Consequently, no observation-based estimates of the contribution from the GIS to the global-mean sea level budget before 1990 are included in the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Here we calculate spatial ice mass loss around the entire GIS from 1900 to the present using aerial imagery from the 1980s. This allows accurate high-resolution mapping of geomorphic features related to the maximum extent of the GIS during the Little Ice Age at the end of the nineteenth century. We estimate the total ice mass loss and its spatial distribution for three periods: 1900-1983 (75.1 ± 29.4 gigatonnes per year), 1983-2003 (73.8 ± 40.5 gigatonnes per year), and 2003-2010 (186.4 ± 18.9 gigatonnes per year). Furthermore, using two surface mass balance models we partition the mass balance into a term for surface mass balance (that is, total precipitation minus total sublimation minus runoff) and a dynamic term. We find that many areas currently undergoing change are identical to those that experienced considerable thinning throughout the twentieth century. We also reveal that the surface mass balance term shows a considerable decrease since 2003, whereas the dynamic term is constant over the past 110 years. Overall, our observation-based findings show that during the twentieth century the GIS contributed at least 25.0 ± 9.4 millimetres of global-mean sea level rise. Our result will help to close the twentieth-century sea level budget, which remains crucial for evaluating the reliability of models used to
Spatial and temporal distribution of mass loss from the Greenland Ice Sheet since AD 1900
NASA Astrophysics Data System (ADS)
Kjeldsen, Kristian K.; Korsgaard, Niels J.; Bjørk, Anders A.; Khan, Shfaqat A.; Box, Jason E.; Funder, Svend; Larsen, Nicolaj K.; Bamber, Jonathan L.; Colgan, William; van den Broeke, Michiel; Siggaard-Andersen, Marie-Louise; Nuth, Christopher; Schomacker, Anders; Andresen, Camilla S.; Willerslev, Eske; Kjær, Kurt H.
2015-12-01
The response of the Greenland Ice Sheet (GIS) to changes in temperature during the twentieth century remains contentious, largely owing to difficulties in estimating the spatial and temporal distribution of ice mass changes before 1992, when Greenland-wide observations first became available. The only previous estimates of change during the twentieth century are based on empirical modelling and energy balance modelling. Consequently, no observation-based estimates of the contribution from the GIS to the global-mean sea level budget before 1990 are included in the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Here we calculate spatial ice mass loss around the entire GIS from 1900 to the present using aerial imagery from the 1980s. This allows accurate high-resolution mapping of geomorphic features related to the maximum extent of the GIS during the Little Ice Age at the end of the nineteenth century. We estimate the total ice mass loss and its spatial distribution for three periods: 1900-1983 (75.1 ± 29.4 gigatonnes per year), 1983-2003 (73.8 ± 40.5 gigatonnes per year), and 2003-2010 (186.4 ± 18.9 gigatonnes per year). Furthermore, using two surface mass balance models we partition the mass balance into a term for surface mass balance (that is, total precipitation minus total sublimation minus runoff) and a dynamic term. We find that many areas currently undergoing change are identical to those that experienced considerable thinning throughout the twentieth century. We also reveal that the surface mass balance term shows a considerable decrease since 2003, whereas the dynamic term is constant over the past 110 years. Overall, our observation-based findings show that during the twentieth century the GIS contributed at least 25.0 ± 9.4 millimetres of global-mean sea level rise. Our result will help to close the twentieth-century sea level budget, which remains crucial for evaluating the reliability of models used to
Pauli-Fierz mass term in modified Plebanski gravity
NASA Astrophysics Data System (ADS)
Beke, David; Palmisano, Giovanni; Speziale, Simone
2012-03-01
We study SO(4) BF theory plus a general quadratic potential, which describes a bi-metric theory of gravity. We identify the profile of the potential leading to a Pauli-Fierz mass term for the massive graviton, thereby avoiding the linearized ghost. We include the Immirzi parameter in our analysis, and find that the mass of the second graviton depends on it. At the non-perturbative level, we find a situation similar to genuine bi-gravities: even choosing the Pauli-Fierz mass term, the ghost mode propagates through the interactions. We present some simple potentials leading to two and three degrees of freedom, and discuss the difficulties of finding a ghost-free bi-gravity with seven degrees of freedom. Finally, we discuss alternative reality conditions for the case of SO(3,1) BF theory, relevant for Lorentzian signature, and give a new solution to the compatibility equation.
Investigation on fluid added mass effect in the modal response of a pump-turbine runner
NASA Astrophysics Data System (ADS)
Y He, L.; He, Y.; Y Luo, Y.; Wang, Z. W.
2013-12-01
With the improvement of technology and manufacturing level of hydraulic turbine, there is a trend to increase the power concentration of the units. As a consequence, heads, fluid velocities and rotational speeds are higher which lead to larger hydraulic excitation forces on the structures. Accordingly, vibration and high stress levels will arise, which may cause fatigue damage. Therefore, how to predict the natural frequencies and mode shapes of the runner during the design stage is of paramount importance. In this paper, numerical simulation to analyze the influence of the surrounding water in a pump-turbine runner modal has been carried out by using finite element method. The modal behavior of the runner in air and in water has been calculated. In addition, the added mass effect by comparing the natural frequencies and mode shapes in both cases has been determined. The results show that, due to the added mass effect of the surrounding water, natural frequencies are considerably reduced. The frequency reduction ratio (FRR) varies in a range of 0.06~0.43, depending on the mode shapes. Vibration amplitude and complexity of modes are the two main factors that affect the reduction ratio of runner natural frequencies. For the FRR of in-phase (IP) mode shapes, the vibration amplitude of each mode is considered to be the dominant reason. It is clear that the FRR decreases as the nodal diameter (ND) increases (except for 0ND). While for counter-phase (CP) mode shapes, with the frequency increases, the runner modes will become more and more complex, as a result of which, the FRR increases.
Structure Group and Fermion-Mass-Term in General Nonlocality
NASA Astrophysics Data System (ADS)
Han, Lei; Wang, Hai-Jun
2016-01-01
In our previous work (Wang J. Math. Phys. 49, 033513 (2008)) two problems remain to be resolved. One is that we lack a minimal group to replace GL(4,C), the other is that the Equation of Motion (EoM) for fermion has no mass term. After careful investigation we find these two problems are linked by conformal group, a subgroup of GL(4,C). The Weyl group, a subgroup of conformal group, can bring about the running of mass, charge etc. while making it responsible for the transformation of interaction vertex. However, once concerning the generation of the mass term in EoM, we have to resort to the whole conformal group, in which the generators K μ play a crucial role in making vacuum vary from space-like (or light-cone-like)to time-like. Physically the starting points are our previous conclusion, ěc E2-ěc B2≠ 0 for massive bosons, and the two-photon process yielding e + e - pair. Finally we get to the conclusion that the mass term of strong interaction is linearly relevant to (chromo-)magnetic flux as well as angular momentum.
Rossi, Stefano; Colazza, Alessandra; Petrarca, Maurizio; Castelli, Enrico; Cappa, Paolo; Krebs, Hermano Igo
2013-01-01
We are designing a pediatric exoskeletal ankle robot (pediatric Anklebot) to promote gait habilitation in children with Cerebral Palsy (CP). Few studies have evaluated how much or whether the unilateral loading of a wearable exoskeleton may have the unwanted effect of altering significantly the gait. The purpose of this study was to evaluate whether adding masses up to 2.5 kg, the estimated overall added mass of the mentioned device, at the knee level alters the gait kinematics. Ten healthy children and eight children with CP, with light or mild gait impairment, walked wearing a knee brace with several masses. Gait parameters and lower-limb joint kinematics were analyzed with an optoelectronic system under six conditions: without brace (natural gait) and with masses placed at the knee level (0.5, 1.0, 1.5, 2.0, 2.5 kg). T-tests and repeated measures ANOVA tests were conducted in order to find noteworthy differences among the trial conditions and between loaded and unloaded legs. No statistically significant differences in gait parameters for both healthy children and children with CP were observed in the five "with added mass" conditions. We found significant differences among "natural gait" and "with added masses" conditions in knee flexion and hip extension angles for healthy children and in knee flexion angle for children with CP. This result can be interpreted as an effect of the mechanical constraint induced by the knee brace rather than the effect associated with load increase. The study demonstrates that the mechanical constraint induced by the brace has a measurable effect on the gait of healthy children and children with CP and that the added mass up to 2.5 kg does not alter the lower limb kinematics. This suggests that wearable devices weighing 25 N or less will not noticeably modify the gait patterns of the population examined here. PMID:24023822
Rossi, Stefano; Colazza, Alessandra; Petrarca, Maurizio; Castelli, Enrico; Cappa, Paolo; Krebs, Hermano Igo
2013-01-01
We are designing a pediatric exoskeletal ankle robot (pediatric Anklebot) to promote gait habilitation in children with Cerebral Palsy (CP). Few studies have evaluated how much or whether the unilateral loading of a wearable exoskeleton may have the unwanted effect of altering significantly the gait. The purpose of this study was to evaluate whether adding masses up to 2.5 kg, the estimated overall added mass of the mentioned device, at the knee level alters the gait kinematics. Ten healthy children and eight children with CP, with light or mild gait impairment, walked wearing a knee brace with several masses. Gait parameters and lower-limb joint kinematics were analyzed with an optoelectronic system under six conditions: without brace (natural gait) and with masses placed at the knee level (0.5, 1.0, 1.5, 2.0, 2.5 kg). T-tests and repeated measures ANOVA tests were conducted in order to find noteworthy differences among the trial conditions and between loaded and unloaded legs. No statistically significant differences in gait parameters for both healthy children and children with CP were observed in the five “with added mass” conditions. We found significant differences among “natural gait” and “with added masses” conditions in knee flexion and hip extension angles for healthy children and in knee flexion angle for children with CP. This result can be interpreted as an effect of the mechanical constraint induced by the knee brace rather than the effect associated with load increase. The study demonstrates that the mechanical constraint induced by the brace has a measurable effect on the gait of healthy children and children with CP and that the added mass up to 2.5 kg does not alter the lower limb kinematics. This suggests that wearable devices weighing 25 N or less will not noticeably modify the gait patterns of the population examined here. PMID:24023822
NASA Astrophysics Data System (ADS)
Guo, X. L.; Wang, L.; Wang, J.; Wang, S. Y.; Liu, Y. Y.; Sun, S.
2014-01-01
The Injector-II of ADS project will include two cryomodules, each of which consists of eight HWR cavities and nine SC solenoid magnets. A test cryomodule (TCM1) containing one HWR cavity and two SC magnets was developed for verification of related technique at the first stage. The TCM1 cryostat was designed by Shanghai Institute of Applied Physics of Chinese Academy of Sciences (SINAP, CAS). The cold mass support assembly in the test cryomodule should accommodate the unbalanced loads induced by each cold mass assembly, the deformation induced by thermal shrinkage, and the thermal stress between different materials. In order to validate the structure design, coupled thermal and mechanical analysis on the cold mass support assembly was performed. The temperature, deformation and stress of the cold mass support assembly were obtained. The results effectively provide the guideline for the design and improvement of the cold mass support assembly.
A stable second-order scheme for fluid-structure interaction with strong added-mass effects
NASA Astrophysics Data System (ADS)
Liu, Jie; Jaiman, Rajeev K.; Gurugubelli, Pardha S.
2014-08-01
In this paper, we present a stable second-order time accurate scheme for solving fluid-structure interaction problems. The scheme uses so-called Combined Field with Explicit Interface (CFEI) advancing formulation based on the Arbitrary Lagrangian-Eulerian approach with finite element procedure. Although loosely-coupled partitioned schemes are often popular choices for simulating FSI problems, these schemes may suffer from inherent instability at low structure to fluid density ratios. We show that our second-order scheme is stable for any mass density ratio and hence is able to handle strong added-mass effects. Energy-based stability proof relies heavily on the connections among extrapolation formula, trapezoidal scheme for second-order equation, and backward difference method for first-order equation. Numerical accuracy and stability of the scheme is assessed with the aid of two-dimensional fluid-structure interaction problems of increasing complexity. We confirm second-order temporal accuracy by numerical experiments on an elastic semi-circular cylinder problem. We verify the accuracy of coupled solutions with respect to the benchmark solutions of a cylinder-elastic bar and the Navier-Stokes flow system. To study the stability of the proposed scheme for strong added-mass effects, we present new results using the combined field formulation for flexible flapping motion of a thin-membrane structure with low mass ratio and strong added-mass effects in a uniform axial flow. Using a systematic series of fluid-structure simulations, a detailed analysis of the coupled response as a function of mass ratio for the case of very low bending rigidity has been presented.
Effect of added mass on the interaction of bubbles in a low-Reynolds-number shear flow.
Lavrenteva, Olga; Prakash, Jai; Nir, Avinoam
2016-02-01
Equal size air bubbles that are entrapped by a Taylor vortex of the secondary flow in a Couette device, thereby defying buoyancy, slowly form a stable ordered ring with equal separation distances between all neighbors. We present two models of the process dynamics based on force balance on a bubble in the presence of other bubbles positioned on the same streamline in a simple shear flow. The forces taken into account are the viscous resistance, the added mass force, and the inertia-induced repulsing force between two bubbles in a low-Reynolds-number shear flow obtained in Prakash et al. [J. Prakash et al., Phys. Rev. E 87, 043002 (2013)]. The first model of the process assumes that each bubble interacts solely with its nearest neighbors. The second model takes into account pairwise interactions among all the bubbles in the ring. The performed dynamic simulations were compared to the experimental results reported in Prakash et al. [J. Prakash et al., Phys. Rev. E 87, 043002 (2013)] and to the results of quasistationary models (ignoring the added mass effect) suggested in that paper. It is demonstrated that taking into account the effect of added mass, the models describe the major effect of the bubbles' ordering, provide good estimation of the relaxation time, and also predict nonmonotonic behavior of the separation distance between the bubbles, which exhibit over- and undershooting of equilibrium separations. The latter effects were observed in experiments, but are not predicted by the quasistationary models. PMID:26986411
Imaging of Cells and Tissues with Mass Spectrometry: Adding Chemical Information to Imaging
Zimmerman, Tyler A.; Monroe, Eric B.; Tucker, Kevin R.; Rubakhin, Stanislav S.; Sweedler, Jonathan V.
2009-01-01
Techniques that map the distribution of compounds in biological tissues can be invaluable in addressing a number of critical questions in biology and medicine. One of the newest methods, mass spectrometric imaging, has enabled investigation of spatial localization for a variety of compounds ranging from atomics to proteins. The ability of mass spectrometry to detect and differentiate a large number of unlabeled compounds makes the approach amenable to the study of complex biological tissues. This chapter focuses on recent advances in the instrumentation and sample preparation protocols that make mass spectrometric imaging of biological samples possible, including strategies for both tissue and single cell imaging using the following mass spectrometric ionization methods: matrix-assisted laser desorption/ionization, secondary ion, electrospray and desorption electrospray. PMID:19118682
Maniaci, D. C.; Li, Y.
2011-10-01
This paper describes a recent study to investigate the applicability of a horizontal-axis wind turbine (HAWT) structural dynamics and unsteady aerodynamics analysis program (FAST and AeroDyn respectively) to modeling the forces on marine hydrokinetic (MHK) turbines. This paper summarizes the added mass model that has been added to AeroDyn. The added mass model only includes flow acceleration perpendicular to the rotor disc, and ignores added mass forces caused by blade deflection. A model of the National Renewable Energy Laboratory's (NREL) Unsteady Aerodynamics Experiment (UAE) Phase VI wind turbine was analyzed using FAST and AeroDyn with sea water conditions and the new added mass model. The results of this analysis exhibited a 3.6% change in thrust for a rapid pitch case and a slight change in amplitude and phase of thrust for a case with 30{sup o} of yaw.
Maniaci, D. C.; Li, Y.
2012-04-01
This paper describes a recent study to investigate the applicability of a horizontal-axis wind turbine (HAWT) structural dynamics and unsteady aerodynamics analysis program (FAST and AeroDyn respectively) to modeling the forces on marine hydrokinetic (MHK) turbines. It summarizes the added mass model that has been added to AeroDyn. The added mass model only includes flow acceleration perpendicular to the rotor disc, and ignores added mass forces caused by blade deflection. A model of the National Renewable Energy Laboratory's (NREL) Unsteady Aerodynamics Experiment (UAE) Phase VI wind turbine was analyzed using FAST and AeroDyn with sea water conditions and the new added mass model. The results of this analysis exhibited a 3.6% change in thrust for a rapid pitch case and a slight change in amplitude and phase of thrust for a case with 30 degrees of yaw.
NASA Astrophysics Data System (ADS)
Valentín, D.; Presas, A.; Egusquiza, E.; Valero, C.
2014-03-01
The dynamic response of submerged and confined disk-like structures is of interest in the flied of hydraulic machinery, especially in hydraulic turbine runners. This response is difficult to be estimated with accuracy due to the strong influence of the boundary conditions. Small radial gaps as well as short axial distances to rigid surfaces greatly modify the dynamic response because the fact of the added mass and damping effects. Moreover, the effect of the shaft coupling is also important for certain mode-shapes of the structure. In the present study, the influence of the added mass effect and boundary conditions on the dynamic behavior of a submerged disk attached to a shaft is evaluated through experimental tests and structural- acoustic coupling numerical simulations. For the experimentation, a test rig has been developed. It consists of a confined disk attached to a shaft inside a cylindrical container full of water. The disk can be fixed at different axial positions along the shaft. Piezoelectric patches are used to excite the disk and the response is measured with submersible accelerometers. For each configuration tested, the natural frequencies of the disk and the shaft are studied. Numerical results have been compared with experimental results.
ERIC Educational Resources Information Center
Raudenbush, Stephen W.
2014-01-01
Proposals to evaluate teachers based on their "value-added" to student test scores generate intense debate. Underlying the debate are concerns about three factors: "bias," "precision," and "relevance." Previous Carnegie Foundation briefs have detailed the reasons why the first two are significant concerns.…
Short-term modern life-like stress exacerbates Aβ-pathology and synapse loss in 3xTg-AD mice.
Baglietto-Vargas, David; Chen, Yuncai; Suh, Dongjin; Ager, Rahasson R; Rodriguez-Ortiz, Carlos J; Medeiros, Rodrigo; Myczek, Kristoffer; Green, Kim N; Baram, Tallie Z; LaFerla, Frank M
2015-09-01
Alzheimer's disease (AD) is a progressive neurological disorder that impairs memory and other cognitive functions in the elderly. The social and financial impacts of AD are overwhelming and are escalating exponentially as a result of population aging. Therefore, identifying AD-related risk factors and the development of more efficacious therapeutic approaches are critical to cure this neurological disorder. Current epidemiological evidence indicates that life experiences, including chronic stress, are a risk for AD. However, it is unknown if short-term stress, lasting for hours, influences the onset or progression of AD. Here, we determined the effect of short-term, multi-modal 'modern life-like' stress on AD pathogenesis and synaptic plasticity in mice bearing three AD mutations (the 3xTg-AD mouse model). We found that combined emotional and physical stress lasting 5 h severely impaired memory in wild-type mice and tended to impact it in already low-performing 3xTg-AD mice. This stress reduced the number of synapse-bearing dendritic spines in 3xTg-AD mice and increased Aβ levels by augmenting AβPP processing. Thus, short-term stress simulating modern-life conditions may exacerbate cognitive deficits in preclinical AD by accelerating amyloid pathology and reducing synapse numbers. Epidemiological evidence indicates that life experiences, including chronic stress, are a risk for Alzheimer disease (AD). However, it is unknown if short stress in the range of hours influences the onset or progression of AD. Here, we determined the effect of short, multi-modal 'modern-lifelike'stress on AD pathogenesis and synaptic plasticity in mice bearing three AD mutations (the 3xTg-AD mouse model). We found that combined emotional and physical stress lasting 5 h severely impaired memory in wild-type mice and tended to impact it in already low-performing 3xTg-AD mice. This stress reduced the number of synapse-bearing dendritic spines in 3xTg-AD mice and increased Aβ levels by
ERIC Educational Resources Information Center
Chetty, Raj; Friedman, John N.; Rockoff, Jonah E.
2011-01-01
Are teachers' impacts on students' test scores ("value-added") a good measure of their quality? This question has sparked debate largely because of disagreement about (1) whether value-added (VA) provides unbiased estimates of teachers' impacts on student achievement and (2) whether high-VA teachers improve students' long-term outcomes.…
ERIC Educational Resources Information Center
Chetty, Raj; Friedman, John N.; Rockoff, Jonah E.
2011-01-01
Are teachers' impacts on students' test scores ("value-added") a good measure of their quality? This question has sparked debate largely because of disagreement about (1) whether value-added (VA) provides unbiased estimates of teachers' impacts on student achievement and (2) whether high-VA teachers improve students' long-term outcomes. We address…
Thearle, Marie S.; Krakoff, Jonathan; Votruba, Susanne B.
2015-01-01
Context: Body fat-free mass (FFM), energy expenditure (EE), and respiratory quotient (RQ) are known predictors of daily food intake. Because FFM largely determines EE, it is unclear whether body composition per se or the underlying metabolism drives dietary intake. Objective: The objective of the study was to test whether 24-hour measures of EE and RQ and their components influence ad libitum food intake independently of FFM. Design and Participants: One hundred seven healthy individuals (62 males/45 females, 84 Native Americans/23 whites; age 33 ± 8 y; body mass index 33 ± 8 kg/m2; body fat 31% ± 8%) had 24-hour measures of EE in a whole-room indirect calorimeter during energy balance, followed by 3 days of ad libitum food intake using computerized vending machine systems. Body composition was estimated by dual-energy x-ray absorptiometry. Main Outcome Measures: FFM, 24-hour EE, RQ, spontaneous physical activity, sleeping EE (sleeping metabolic rate), awake and fed thermogenesis, and ad libitum food intake (INTAKE) were measured. Results: Higher 24-hour RQ (P < .001, partial R2 = 16%) and EE (P = .01, partial R2 = 7%), but not FFM (P = .65), were independent predictors of INTAKE. Mediation analysis demonstrated that 24-hour EE is responsible for 80% of the FFM effect on INTAKE (44.5 ± 16.9 kcal ingested per kilogram of FFM, P= .01), whereas the unique effect due to solely FFM was negligible (10.6 ± 23.2, P = .65). Spontaneous physical activity (r = 0.33, P = .001), but not sleeping metabolic rate (P = .71), positively predicted INTAKE, whereas higher awake and fed thermogenesis determined greater INTAKE only in subjects with a body mass index of 29 kg/m2 or less (r = 0.44, P = .01). Conclusions: EE and RQ, rather than FFM, independently determine INTAKE, suggesting that competitive energy-sensing mechanisms driven by the preferential macronutrient oxidation and total energy demands may regulate food intake. PMID:26086330
NASA Astrophysics Data System (ADS)
Lee, Seong-Keon; Joung, Tae-Hwan; Cheon, Se-Jong; Jang, Taek-Soo; Lee, Jeong-Hee
2011-09-01
This paper shows added mass and inertia can be acquired from the pure heaving motion and pure pitching motion respectively. A Vertical Planar Motion Mechanism (VPMM) test for the spheroid-type Unmanned Underwater Vehicle (UUV) was compared with a theoretical calculation and Computational Fluid Dynamics (CFD) analysis in this paper. The VPMM test has been carried out at a towing tank with specially manufactured equipment. The linear equations of motion on the vertical plane were considered for theoretical calculation, and CFD results were obtained by commercial CFD package. The VPMM test results show good agreement with theoretical calculations and the CFD results, so that the applicability of the VPMM equipment for an underwater vehicle can be verified with a sufficient accuracy.
NASA Astrophysics Data System (ADS)
Banks, J. W.; Henshaw, W. D.; Kapila, A. K.; Schwendeman, D. W.
2016-01-01
We describe an added-mass partitioned (AMP) algorithm for solving fluid-structure interaction (FSI) problems involving inviscid compressible fluids interacting with nonlinear solids that undergo large rotations and displacements. The computational approach is a mixed Eulerian-Lagrangian scheme that makes use of deforming composite grids (DCG) to treat large changes in the geometry in an accurate, flexible, and robust manner. The current work extends the AMP algorithm developed in Banks et al. [1] for linearly elasticity to the case of nonlinear solids. To ensure stability for the case of light solids, the new AMP algorithm embeds an approximate solution of a nonlinear fluid-solid Riemann (FSR) problem into the interface treatment. The solution to the FSR problem is derived and shown to be of a similar form to that derived for linear solids: the state on the interface being fundamentally an impedance-weighted average of the fluid and solid states. Numerical simulations demonstrate that the AMP algorithm is stable even for light solids when added-mass effects are large. The accuracy and stability of the AMP scheme is verified by comparison to an exact solution using the method of analytical solutions and to a semi-analytical solution that is obtained for a rotating solid disk immersed in a fluid. The scheme is applied to the simulation of a planar shock impacting a light elliptical-shaped solid, and comparisons are made between solutions of the FSI problem for a neo-Hookean solid, a linearly elastic solid, and a rigid solid. The ability of the approach to handle large deformations is demonstrated for a problem of a high-speed flow past a light, thin, and flexible solid beam.
Assessment Of Errors In Long-Term Mass Balance Records From Alaska, USA
NASA Astrophysics Data System (ADS)
March, R. S.; van Beusekom, A. E.; O'Neel, S.
2009-12-01
The USGS maintains a long-term glacier mass balance monitoring program at Gulkana and Wolverine glaciers in Alaska. The records produced by this program are a major component of the world’s mountain glacier balance inventory due to the scarcity of such long-term measurements. Recent data that show rapid glacier volume loss in Alaska further emphasize the importance of these records. An integral part of the long-term mass balance program is repeated assessment of the validity of the methods because bias errors in mass balance data are cumulative. Long-term glacier mass balance records in Alaska have previously been shown to be in good agreement with geodetically determined volume changes despite a minimal network of mass balance stakes. Because the rates of negative mass balance and change in glacier geometry have recently increased, this work reassess whether or not the existing stake networks and method of determining glacier-average balance are still working adequately.
NASA Astrophysics Data System (ADS)
Günther, Uwe; Zhuk, Alexander; Bezerra, Valdir B.; Romero, Carlos
2005-08-01
We study multi-dimensional gravitational models with scalar curvature nonlinearities of types R-1 and R4. It is assumed that the corresponding higher dimensional spacetime manifolds undergo a spontaneous compactification to manifolds with a warped product structure. Special attention has been paid to the stability of the extra-dimensional factor spaces. It is shown that for certain parameter regions the systems allow for a freezing stabilization of these spaces. In particular, we find for the R-1 model that configurations with stabilized extra dimensions do not provide a late-time acceleration (they are AdS), whereas the solution branch which allows for accelerated expansion (the dS branch) is incompatible with stabilized factor spaces. In the case of the R4 model, we obtain that the stability region in parameter space depends on the total dimension D = dim(M) of the higher dimensional spacetime M. For D > 8 the stability region consists of a single (absolutely stable) sector which is shielded from a conformal singularity (and an antigravity sector beyond it) by a potential barrier of infinite height and width. This sector is smoothly connected with the stability region of a curvature-linear model. For D < 8 an additional (metastable) sector exists which is separated from the conformal singularity by a potential barrier of finite height and width so that systems in this sector are prone to collapse into the conformal singularity. This second sector is not smoothly connected with the first (absolutely stable) one. Several limiting cases and the possibility of inflation are discussed for the R4 model.
Adaptive Wireless Ad-hoc Sensor Networks for Long-term and Event-oriented Environmental Monitoring
NASA Astrophysics Data System (ADS)
Bumberger, Jan; Mollenhauer, Hannes; Remmler, Paul; Schaedler, Martin; Schima, Robert; Mollenhauer, Olaf; Hutschenreuther, Tino; Toepfer, Hannes; Dietrich, Peter
2015-04-01
Ecosystems are often characterized by their high heterogeneity, complexity and dynamic. Hence, single point measurements are often not sufficient for their complete representation. The application of wireless sensor networks in terrestrial and aquatic environmental systems offer significant benefits as a better consideration to the local test conditions, due to the simple adjustment of the sensor distribution, the sensor types and the sample rate. Another advantage of wireless ad-hoc sensor networks is their self-organizing behavior, resulting in a major reduction in installation and operation costs and time. In addition, individual point measurements with a sensor are significantly improved by measuring at several points continuously. In this work a concept and realization for Long-term ecosystem research is given in the field monitoring of micrometeorology and soil parameters for the interaction of biotic and abiotic processes. This long term analyses are part of the Global Change Experimental Facility (GCEF), a large field-based experimental platform to assess the effects of climate change on ecosystem functions and processes under different land-use scenarios. Regarding to the adaptive behavior of the network, also a mobile version was developed to overcome the lack of information of temporally and spatially fixed measurements for the detection and recording of highly dynamic or time limited processes. First results of different field campaigns are given to present the potentials and limitations of this application in environmental science, especially for the monitoring of the interaction of biotic and abiotic processes, soil-atmosphere interaction and the validation of remote sensing data.
Adaptive Wireless Ad-hoc Sensor Networks for Long-term and Event-oriented Environmental Monitoring
NASA Astrophysics Data System (ADS)
Bumberger, Jan; Mollenhauer, Hannes; Remmler, Paul; Chirila, Andrei Marian; Mollenhauer, Olaf; Hutschenreuther, Tino; Toepfer, Hannes; Dietrich, Peter
2016-04-01
Ecosystems are often characterized by their high heterogeneity, complexity and dynamic. Hence, single point measurements are often not sufficient for their complete representation. The application of wireless sensor networks in terrestrial and aquatic environmental systems offer significant benefits as a better consideration to the local test conditions, due to the simple adjustment of the sensor distribution, the sensor types and the sample rate. Another advantage of wireless ad-hoc sensor networks is their self-organizing behavior, resulting in a major reduction in installation and operation costs and time. In addition, individual point measurements with a sensor are significantly improved by measuring at several points continuously. In this work a concept and realization for Long-term ecosystem research is given in the field monitoring of micrometeorology and soil parameters for the interaction of biotic and abiotic processes. This long term analyses are part of the Global Change Experimental Facility (GCEF), a large field-based experimental platform to assess the effects of climate change on ecosystem functions and processes under different land-use scenarios. Regarding to the adaptive behavior of the network, also a mobile version was developed to overcome the lack of information of temporally and spatially fixed measurements for the detection and recording of highly dynamic or time limited processes. First results of different field campaigns are given to present the potentials and limitations of this application in environmental science, especially for the monitoring of the interaction of biotic and abiotic processes, soil-atmosphere interaction and the validation of remote sensing data.
Friedman, Michael A.; Bailey, Alyssa M.; Rondon, Matthew J.; McNerny, Erin M.; Sahar, Nadder D.; Kohn, David H.
2016-01-01
Exercise has long-lasting benefits to bone health that may help prevent fractures by increasing bone mass, bone strength, and tissue quality. Long-term exercise of 6–12 weeks in rodents increases bone mass and bone strength. However, in growing mice, a short-term exercise program of 3 weeks can limit increases in bone mass and structural strength, compared to non-exercised controls. Short-term exercise can, however, increase tissue strength, suggesting that exercise may create competition for minerals that favors initially improving tissue-level properties over structural-level properties. It was therefore hypothesized that adding calcium and phosphorus supplements to the diet may prevent decreases in bone mass and structural strength during a short-term exercise program, while leading to greater bone mass and structural strength than exercise alone after a long-term exercise program. A short-term exercise experiment was done for 3 weeks, and a long-term exercise experiment was done for 8 weeks. For each experiment, male 16-week old C57BL/6 mice were assigned to 4 weight-matched groups–exercise and non-exercise groups fed a control or mineral-supplemented diet. Exercise consisted of treadmill running at 12 m/min, 30 min/day for 7 days/week. After 3 weeks, exercised mice fed the supplemented diet had significantly increased tibial tissue mineral content (TMC) and cross-sectional area over exercised mice fed the control diet. After 8 weeks, tibial TMC, cross-sectional area, yield force, and ultimate force were greater from the combined treatments than from either exercise or supplemented diet alone. Serum markers of bone formation (PINP) and resorption (CTX) were both decreased by exercise on day 2. In exercised mice, day 2 PINP was significantly positively correlated with day 2 serum Ca, a correlation that was weaker and negative in non-exercised mice. Increasing dietary mineral consumption during an exercise program increases bone mass after 3 weeks and
Friedman, Michael A; Bailey, Alyssa M; Rondon, Matthew J; McNerny, Erin M; Sahar, Nadder D; Kohn, David H
2016-01-01
Exercise has long-lasting benefits to bone health that may help prevent fractures by increasing bone mass, bone strength, and tissue quality. Long-term exercise of 6-12 weeks in rodents increases bone mass and bone strength. However, in growing mice, a short-term exercise program of 3 weeks can limit increases in bone mass and structural strength, compared to non-exercised controls. Short-term exercise can, however, increase tissue strength, suggesting that exercise may create competition for minerals that favors initially improving tissue-level properties over structural-level properties. It was therefore hypothesized that adding calcium and phosphorus supplements to the diet may prevent decreases in bone mass and structural strength during a short-term exercise program, while leading to greater bone mass and structural strength than exercise alone after a long-term exercise program. A short-term exercise experiment was done for 3 weeks, and a long-term exercise experiment was done for 8 weeks. For each experiment, male 16-week old C57BL/6 mice were assigned to 4 weight-matched groups-exercise and non-exercise groups fed a control or mineral-supplemented diet. Exercise consisted of treadmill running at 12 m/min, 30 min/day for 7 days/week. After 3 weeks, exercised mice fed the supplemented diet had significantly increased tibial tissue mineral content (TMC) and cross-sectional area over exercised mice fed the control diet. After 8 weeks, tibial TMC, cross-sectional area, yield force, and ultimate force were greater from the combined treatments than from either exercise or supplemented diet alone. Serum markers of bone formation (PINP) and resorption (CTX) were both decreased by exercise on day 2. In exercised mice, day 2 PINP was significantly positively correlated with day 2 serum Ca, a correlation that was weaker and negative in non-exercised mice. Increasing dietary mineral consumption during an exercise program increases bone mass after 3 weeks and increases
Rojas-Martínez, A; Manzanera, A G; Sukin, S W; Esteban-María, J; González-Guerrero, J F; Gomez-Guerra, L; Garza-Guajardo, R; Flores-Gutiérrez, J P; Elizondo Riojas, G; Delgado-Enciso, I; Ortiz-López, R; Aguilar, L K; Butler, E B; Barrera-Saldaña, H A; Aguilar-Cordova, E
2013-11-01
A phase I-II study to evaluate gene-mediated cytotoxic immunotherapy in newly diagnosed prostate cancer before radical prostatectomy was conducted in Monterrey, Mexico. First, to investigate delivery of adenovirus to the prostate, fluorescently labeled vector was injected into fresh prostatectomy specimens and distribution was visually analyzed. The optimal volume and site instillation was then used for transrectal ultrasound guided intraprostatic injection in 10 patients with adenocarcinoma scheduled for radical prostatectomy. Each received two apical and two basal 0.5 ml injections of AdV-tk for a total of 1 × 10(11) vp followed by 14 days of prodrug. Nine patients continued to tumor resection: six high risk, one intermediate and two low risk. In vivo vector distribution was analyzed from the resected tissue of four patients. Patients were monitored for tumor progression and acute and long-term safety. For vector delivery, two apical and two basal injections of 0.5 ml led to optimal organ-wide distribution ex vivo and in vivo. Cytotoxicity was evidenced by transient rise in PSA and tumor histology. There were no significant adverse events deemed related to the treatment and no late toxicities after median follow-up of 11.3 years. All six high-risk patients had positive surgical margins and one had seminal vesicle involvement. Despite slow PSA rise post surgery in three of these patients, none developed metastases. The intermediate- and low-risk patients had complete resections and none have progressed. In conclusion, in vivo transrectal ultrasound guided instillation of an adenoviral vector into four sites in the prostate was practical as an outpatient procedure, well tolerated and led to distribution throughout the intraprostatic tumor mass. AdV-tk demonstrated no significant acute or late toxicities. Trends in PSA and disease progression conveyed the possibility of a sustained immune response against residual disease. PMID:24052127
Rojas-Martínez, Augusto; Manzanera, Andrea G.; Sukin, Steven W.; Esteban-María, Jacinto; González-Guerrero, Juan Francisco; Gomez-Guerra, Lauro; Garza-Guajardo, Raquel; Flores-Gutiérrez, Juan Pablo; Riojas, Guillermo Elizondo; Delgado-Enciso, Iván; Ortiz-López, Rocío; Aguilar, Laura K.; Butler, E. Brian; Barrera-Saldaña, Hugo A.; Aguilar-Cordova, Estuardo
2013-01-01
A phase I-II study to evaluate gene mediated cytotoxic immunotherapy in newly diagnosed prostate cancer before radical prostatectomy was conducted in Monterrey, Mexico. Methods To investigate delivery of adenovirus to the prostate, fluorescently labeled vector was injected into fresh prostatectomy specimens and distribution visually analyzed. The optimal volume and site instillation was then used for transrectal ultrasound guided intraprostatic injection in 10 patients with adenocarcinoma scheduled for radical prostatectomy. Each received 2-apical and 2-basal 0.5 ml injections of AdV-tk for a total of 1×1011 vp followed by 14 days of prodrug. Nine patients continued to tumor resection: 6 high-risk, 1 intermediate and 2 low-risk. In-vivo vector distribution was analyzed from resected tissue of four patients. Patients were monitored for tumor progression and acute and long-term safety. Results Two apical and two basal injections of 0.5ml led to optimal organ-wide distribution of an adenoviral vector ex-vivo and in-vivo. Cytotoxicity was evidenced by transient rise in PSA and tumor histology. There were no significant adverse events deemed related to the treatment and no late toxicities after median follow up of 11.3 years. All six high-risk patients had positive surgical margins and one had seminal vesicle involvement. Despite slow PSA rise post-surgery in 3 of these patients, none developed metastases. The intermediate and low-risk patients had complete resections and none have progressed. Conclusion In-vivo transrectal ultrasound guided instillation of an adenoviral vector into four sites in the prostate was practical as an outpatient procedure, well tolerated and led to distribution throughout the intraprostatic tumor mass. AdV-tk demonstrated no significant acute or late toxicities. Trends in PSA and disease progression conveyed the possibility of a sustained immune response against residual disease. PMID:24052127
NASA Astrophysics Data System (ADS)
Kremer, K.; Simpson, G.; Girardclos, S.
2012-04-01
Steep continental margins are known to collapse, producing submarine landslides that can generate Tsunamis. At smaller scale, the same can happen in lake basins. Lake sediments are excellent archives of such events. The study of mass movement deposits in lake sediments allows a better knowledge of past natural hazards in intracontinental regions at historic and prehistoric timescales. In Lake Geneva (Switzerland-France), more than 100 km of high resolution seismic reflection profiles reveal two distinct sequences in the lakes' late Holocene sedimentation history. The first sequence consists mainly of a succession of five large lens-shaped seismic units (A to E), characterized by transparent/chaotic seismic facies with irregular lower boundaries, interpreted as mass-movement deposits. These units are interbedded with parallel, continuous and strong amplitude reflections, interpreted as the 'background' lake sediment. The largest and most recent unit (E) is 5 m thick, covers an area of 50 km2 and has an estimated minimum volume of 0.25 km3, making it the largest sub-lacustrine mass-movement unit in Switzerland. The second sediment sequence consists of 5 m of 'background' seismic facies with parallel geometry, varying at small scale between chaotic/transparent and continuous, high amplitude reflections, which is interpreted as alternating turbidite and hemipelagic layers, respectively. Four 10 m long sediment cores confirm the seismic interpretation and show that the 5 m thick deposit can be described as a co-genetic debrite turbidite (Talling et al., 2004). Radiocarbon dating of plant macro-remains reveals that the unit E deposit may be linked to the Tauredunum rockslide of 563 AD in Rhone delta area. The induced sediment failure in the Rhone delta triggered a tsunami wave destroying parts of the Geneva Burgudian city and other villages at the lake borders as described in historical records. Numerical simulations, based on the shallow water equations, performed here
Long-term summer temperatures variations in the southern French Alps, A.D. 749-2007
NASA Astrophysics Data System (ADS)
Corona, C.; Edouard, J. L.; Guiot, J.; Guibal, F.; Thomas, A.; Saulnier, M.
2009-04-01
With respect to the past millennium and Europe, only a few temperature reconstruction from sensitive composite tree ring width records exist from northern Scandinavia (Briffa et al. 2007; Helama et al. 2005) and the Alps (Büntgen et al. 2005; Nicolussi and Patzelt 2000). Only one, in the Spanish Pyrenees (Büntgen et al. 2008) concerns the Mediterranean region. The purpose of this presentation is a reconstruction of the summer temperatures over the southern French Alps (44-45°N 6°29-7°40E) during the last millennium. This reconstruction, the first regional one centered on this part of the Alps extending prior to 1000 A.D. and extends forward into the twenty-first century (749-2007). It is based on a network of seventeen multi-centennial larch and stone pine unpublished chronologies combining three hundred and fifty three tree-ring width series of living and dry-dead timberline wood (above 2000 m a.s.l.). These series are standardized using an Adaptative Regional Growth Curve (Nicault et al. 2008) allowing the preservation of inter-annual to multi-centennial length variability due to climate. Spatially resolved instrumental measurements (1°x1° Latlong) from the HISTALP dataset (Auer et al. 2007) back to 1800 A.D. reveal strongest growth response to current-year June-August mean temperatures. The proxies are calibrated to instrumental target records by combining an analogue technique, which is able to extend the too short tree-ring series, with an artificial neural network technique for an optimal non-linear calibration including a bootstrap technique for calculating error assessment on the reconstruction. This reconstruction allows the putative "Medieval Warm Period" (MWP) to be described for French Alps and to be compared with 20th-century warming in modeling and attribution studies. The new reconstruction is compared with reconstructions based on historical sources (Pfister et al. 1994), grape ripening (Meier, 2007), speleothems (Mangini et al. 2005
NASA Astrophysics Data System (ADS)
Kluiving, Sjoerd; Bekkema, Marijke; Roymans, Nico; van Mourik, Jan
2015-04-01
Long-term archaeological data gathering in the southern Netherlands may deliver an unprecedented regional comparison that could be exemplary for the Pleistocene sand areas of the Northwest European Plain. On a micro-scale level, it has become clear that Bronze Age (2000-800 BC) and Iron Age (800-12 BC) farmers intensively used the landscape, resulting in a relatively dense distribution pattern of settlements all over the ridges and planes of the cover sand landscape. However, this agricultural use of the landscape related to the "celtic field" system led to a process of soil degradation by increased acidification during which Umbric Podzols gradually transformed into Carbic Podzols that could no longer be used as farmland. According to established "models," this process of "secondary podzolization" particularly affected those sections of the landscape that were dominated by dry sandy soils with a low loam content (loam = clay and silt, between c. 10% and 20%). In the Late Iron Age (250-12 BC), the changing soil conditions resulted in a dramatic shift in the habitation pattern that clearly manifests itself in the Roman period (12 BC-410 AD); on the local scale, the habitation moved from the degenerated soils to nearby areas with better soil conditions (higher loam content), which became more densely inhabited now than in the Bronze Age/Early Iron Age (2000-500 BC). The introduction of new land management (in the later Iron Age, and also by Romans) could also have been important for soil degradation. The areas where the Roman period settlements concentrated became also the areas where we can find the early medieval habitation (447-751 AD) and where the Plaggic Anthrosols started to develop in the late medieval period (1270-1500 AD). This poster is based on the analysis of soil properties. Measured loam values of soil samples (n=181) in Veldhoven, southern Netherlands, are in agreement with the described model that the plaggen cover is located on soils containing high
NASA Astrophysics Data System (ADS)
Chanzy, André; Chabbi, Abad; Houot, Sabine; Lafolie, François; Pichot, Christian; Raynal, Hélène; Saint-André, Laurent; Clobert, Jean; Greiveldinger, Lucile
2015-04-01
term experiments to implement novel observational systems. Through active collaboration with the teams in charge of the experiments, users will take advantage of the site characterization, historical data, monitoring setup and access to different treatments experimental field with differentiated properties induced by repeated treatment. • Access to soil and vegetation samples collected at different dates that may be reanalyzed a posteriori to take profit of technological progress. • Delivery of reference data on ecosystems subjected to a gradient of anthropogenic and climatic pressures. The research infrastructure level is appropriate to implement a harmonization policy for the measurement and observation protocols. Moreover it offers the possibility of developing an ambitious strategy in integrating data and models. These can contribute to the experimental process for protocol design or data quality control. Moreover, they offer an efficient way for promoting data reuse thus giving a strong added value to the existing data bases. Therefore, building interoperability between models and experimental platform data bases is an important objective to improve the quality of experimental infrastructure and provide users with seamless and integrated information systems. We present how this is operated in AnaEE-France with different tasks as the development of a controlled vocabulary, tools to annotate data and model variables with metadata based on ontologies and the development of webservice to harvest data from the data base to the modelling platform environment. Finally some examples of key results taking profit of the range of experiments are provided.
An MRI-Derived Definition of MCI-to-AD Conversion for Long-Term, Automatic Prognosis of MCI Patients
Aksu, Yaman; Miller, David J.; Kesidis, George; Bigler, Don C.; Yang, Qing X.
2011-01-01
Alzheimer's disease (AD) and mild cognitive impairment (MCI) are of great current research interest. While there is no consensus on whether MCIs actually “convert” to AD, this concept is widely applied. Thus, the more important question is not whether MCIs convert, but what is the best such definition. We focus on automatic prognostication, nominally using only a baseline brain image, of whether an MCI will convert within a multi-year period following the initial clinical visit. This is not a traditional supervised learning problem since, in ADNI, there are no definitive labeled conversion examples. It is not unsupervised, either, since there are (labeled) ADs and Controls, as well as cognitive scores for MCIs. Prior works have defined MCI subclasses based on whether or not clinical scores significantly change from baseline. There are concerns with these definitions, however, since, e.g., most MCIs (and ADs) do not change from a baseline CDR = 0.5 at any subsequent visit in ADNI, even while physiological changes may be occurring. These works ignore rich phenotypical information in an MCI patient's brain scan and labeled AD and Control examples, in defining conversion. We propose an innovative definition, wherein an MCI is a converter if any of the patient's brain scans are classified “AD” by a Control-AD classifier. This definition bootstraps design of a second classifier, specifically trained to predict whether or not MCIs will convert. We thus predict whether an AD-Control classifier will predict that a patient has AD. Our results demonstrate that this definition leads not only to much higher prognostic accuracy than by-CDR conversion, but also to subpopulations more consistent with known AD biomarkers (including CSF markers). We also identify key prognostic brain region biomarkers. PMID:22022375
Mansbach, William E; Mace, Ryan A
2016-09-01
We compared the accuracy of the Brief Cognitive Assessment Tool-Short Form (BCAT-SF) and AD8 in identifying mild cognitive impairment (MCI) and dementia among long-term care residents. Psychometric analyses of 357 long-term care residents (n = 228, nursing home; n = 129, assisted living) in Maryland referred for neuropsychological evaluation evidenced robust internal consistency reliability and construct validity for the BCAT-SF. Furthermore, hierarchical logistic regression and receiver operating characteristic curve analyses demonstrated superior predictive validity for the BCAT-SF in identifying MCI and dementia relative to the AD8. In contrast, previously reported psychometric properties or cut scores for the AD8 could not be cross-validated in this long-term care sample. Based on these findings, the BCAT-SF appears to be a more reliable and valid screening instrument than the AD8 for rapidly identifying MCI and dementia in long-term care residents. PMID:26873431
Effect of short-term microgravity and long-term hindlimb unloading on rat cardiac mass and function
NASA Technical Reports Server (NTRS)
Ray, C. A.; Vasques, M.; Miller, T. A.; Wilkerson, M. K.; Delp, M. D.
2001-01-01
The purpose of this study was to test the hypothesis that exposure to short-term microgravity or long-term hindlimb unloading induces cardiac atrophy in male Sprague-Dawley rats. For the microgravity study, rats were subdivided into four groups: preflight (PF, n = 12); flight (Fl, n = 7); flight cage simulation (Sim, n = 6), and vivarium control (Viv, n = 7). Animals in the Fl group were exposed to 7 days of microgravity during the Spacelab 3 mission. Animals in the hindlimb-unloading study were subdivided into three groups: control (Con, n = 20), 7-day hindlimb-unloaded (7HU, n = 10), and 28-day hindlimb-unloaded (28HU, n = 19). Heart mass was unchanged in adult animals exposed to 7 days of actual microgravity (PF 1.33 +/- 0.03 g; Fl 1.32 +/- 0.02 g; Sim 1.28 +/- 0.04 g; Viv 1.35 +/- 0.04 g). Similarly, heart mass was unaltered with hindlimb unloading (Con 1.40 +/- 0.04 g; 7HU 1.35 +/- 0.06 g; 28HU 1.42 +/- 0.03 g). Hindlimb unloading also had no effect on the peak rate of rise in left ventricular pressure, an estimate of myocardial contractility (Con 8,055 +/- 385 mmHg/s; 28HU 8,545 +/- 755 mmHg/s). These data suggest that cardiac atrophy does not occur after short-term exposure to microgravity and that neither short- nor long-term simulated microgravity alters cardiac mass or function.
Potential of mass trapping for long-term pest management and eradication of invasive species.
El-Sayed, A M; Suckling, D M; Wearing, C H; Byers, J A
2006-10-01
Semiochemical-based pest management programs comprise three major approaches that are being used to provide environmentally friendly control methods of insect pests: mass trapping, "lure and kill," and mating disruption. In this article, we review the potential of mass trapping in long-term pest management as well as in the eradication of invasive species. We discuss similarities and differences between mass trapping and other two main approaches of semiochemical-based pest management programs. We highlight several study cases where mass trapping has been used either in long-term pest management [e.g., codling moth, Cydia pomonella (L.); pink bollworm, Pectinophora gossypiella (Saunders); bark beetles, palm weevils, corn rootworms (Diabrotica spp.); and fruit flies] or in eradication of invasive species [e.g., gypsy moth, Lymantria dispar (L.); and boll weevil, Anthonomus grandis grandis Boheman). We list the critical issues that affect the efficacy of mass trapping and compare these with previously published models developed to investigate mass trapping efficacy in pest control. We conclude that mass trapping has good potential to suppress or eradicate low-density, isolated pest populations; however, its full potential in pest management has not been adequately realized and therefore encourages further research and development of this technology. PMID:17066782
Ambiguities and subtleties in fermion mass terms in practical quantum field theory
Cheng, Yifan Kong, Otto C.W.
2014-09-15
This is a review on structure of the fermion mass terms in quantum field theory, under the perspective of its practical applications in the real physics of Nature—specifically, we discuss fermion mass structure in the Standard Model of high energy physics, which successfully describes fundamental physics up to the TeV scale. The review is meant to be pedagogical, with detailed mathematics presented beyond the level one can find any easily in the textbooks. The discussions, however, bring up important subtleties and ambiguities about the subject that may be less than well appreciated. In fact, the naive perspective of the nature and masses of fermions as one would easily drawn from the presentations of fermion fields and their equations of motion from a typical textbook on quantum field theory leads to some confusing or even wrong statements which we clarify here. In particular, we illustrate clearly that a Dirac fermion mass eigenstate is mathematically equivalent to two degenerated Majorana fermion mass eigenstates at least as long as the mass terms are concerned. There are further ambiguities and subtleties in the exact description of the eigenstate(s). Especially, for the case of neutrinos, the use of the Dirac or Majorana terminology may be mostly a matter of choice. The common usage of such terminology is rather based on the broken SU(2) charges of the related Weyl spinors hence conventional and may not be unambiguously extended to cover more complicate models. - Highlights: • Structure of fermion mass terms in practical quantum field theory is reviewed. • Important subtleties and ambiguities on the subject are clarified. • A mass eigenstate Dirac fermion and two degenerated Majorana ones are equivalent. • The conventional meaning of such terminology for neutrinos is critically discussed.
Neutron-proton effective mass splitting in terms of symmetry energy and its density slope
Chakraborty, S.; Sahoo, B.; Sahoo, S.
2015-01-15
Using a simple density-dependent finite-range effective interaction having Yukawa form, the density dependence of isoscalar and isovector effective masses is studied. The isovector effective mass is found to be different for different pairs of like and unlike nucleons. Using HVH theorem, the neutron-proton effective mass splitting is represented in terms of symmetry energy and its density slope. It is again observed that the neutron-proton effective mass splitting has got a positive value when isoscalar effective mass is greater than the isovector effective mass and has a negative value for the opposite case. Furthermore, the neutron-proton effective mass splitting is found to have a linear dependence on asymmetry β. The second-order symmetry potential has a vital role in the determination of density slope of symmetry energy but it does not have any contribution on neutron-proton effective mass splitting. The finite-range effective interaction is compared with the SLy2, SKM, f{sub −}, f{sub 0}, and f{sub +} forms of interactions.
Benet, S B; Bloom, P N
1998-01-01
The ingredients for a financial calamity affecting both government and individual citizens and their families are in place. Federal legislators have made little progress in addressing the health care needs of an aging America, and the proposals that have been advanced offer little or nothing in the way of better help with long-term care. One potential scenario is that middle-income retirees placed in long-term care will exhaust their finances and then turn to Medicaid, creating an enormous expense for the government. Long-term care insurance could alleviate the situation, but current practices by the insurance industry in marketing products to the elderly complicate the sale of such insurance. Consumers approaching retirement age are receptive to this type of product, but first they must be made aware of the merits of long-term care insurance and the paucity of alternatives. Only then can marketers promote specific products successfully. PMID:10179394
Ambiguities and subtleties in fermion mass terms in practical quantum field theory
NASA Astrophysics Data System (ADS)
Cheng, Yifan; Kong, Otto C. W.
2014-09-01
This is a review on structure of the fermion mass terms in quantum field theory, under the perspective of its practical applications in the real physics of Nature-specifically, we discuss fermion mass structure in the Standard Model of high energy physics, which successfully describes fundamental physics up to the TeV scale. The review is meant to be pedagogical, with detailed mathematics presented beyond the level one can find any easily in the textbooks. The discussions, however, bring up important subtleties and ambiguities about the subject that may be less than well appreciated. In fact, the naive perspective of the nature and masses of fermions as one would easily drawn from the presentations of fermion fields and their equations of motion from a typical textbook on quantum field theory leads to some confusing or even wrong statements which we clarify here. In particular, we illustrate clearly that a Dirac fermion mass eigenstate is mathematically equivalent to two degenerated Majorana fermion mass eigenstates at least as long as the mass terms are concerned. There are further ambiguities and subtleties in the exact description of the eigenstate(s). Especially, for the case of neutrinos, the use of the Dirac or Majorana terminology may be mostly a matter of choice. The common usage of such terminology is rather based on the broken SU(2) charges of the related Weyl spinors hence conventional and may not be unambiguously extended to cover more complicate models.
Liu, ChunMei; Yuan, HaiRong; Zou, DeXun; Liu, YanPing; Zhu, BaoNing; Li, XiuJin
2015-01-01
This research applied sodium hydroxide (NaOH) pretreatment and trace elements to improve biomethane production when using corn stover for anaerobic digestion. Full-factor experimental tests identified the best combination of trace elements with the NaOH pretreatment, indicating that the best combination was with 1.0, 0.4, and 0.4 mg·L−1·d−1 of elements Fe, Co, and Ni, respectively. The cumulative biomethane production adding NaOH pretreatment and trace elements was 11,367 mL; total solid bioconversion rate was 55.7%, which was 41.8%–62.2% higher than with NaOH-pretreatment alone and 22.2%–56.3% higher than with untreated corn stover. The best combination was obtained 5–9 days shorter than T90 and maintained good system operation stability. Only a fraction of the trace elements in the best combination was present in the resulting solution; more than 85% of the total amounts added were transferred into the solid fraction. Adding 0.897 g of Fe, 0.389 g of Co, and 0.349 g of Ni satisfied anaerobic digestion needs and enhanced biological activity at the beginning of the operation. The results showed that NaOH pretreatment and adding trace elements improve corn stover biodegradability and enhance biomethane production. PMID:26137469
Liu, ChunMei; Yuan, HaiRong; Zou, DeXun; Liu, YanPing; Zhu, BaoNing; Li, XiuJin
2015-01-01
This research applied sodium hydroxide (NaOH) pretreatment and trace elements to improve biomethane production when using corn stover for anaerobic digestion. Full-factor experimental tests identified the best combination of trace elements with the NaOH pretreatment, indicating that the best combination was with 1.0, 0.4, and 0.4 mg·L(-1)·d(-1) of elements Fe, Co, and Ni, respectively. The cumulative biomethane production adding NaOH pretreatment and trace elements was 11,367 mL; total solid bioconversion rate was 55.7%, which was 41.8%-62.2% higher than with NaOH-pretreatment alone and 22.2%-56.3% higher than with untreated corn stover. The best combination was obtained 5-9 days shorter than T90 and maintained good system operation stability. Only a fraction of the trace elements in the best combination was present in the resulting solution; more than 85% of the total amounts added were transferred into the solid fraction. Adding 0.897 g of Fe, 0.389 g of Co, and 0.349 g of Ni satisfied anaerobic digestion needs and enhanced biological activity at the beginning of the operation. The results showed that NaOH pretreatment and adding trace elements improve corn stover biodegradability and enhance biomethane production. PMID:26137469
Aoki phases in the lattice Gross-Neveu model with flavored mass terms
Creutz, Michael; Kimura, Taro; Misumi, Tatsuhiro
2011-05-01
We investigate the parity-broken phase structure for staggered and naive fermions in the Gross-Neveu model as a toy model of QCD. We consider a generalized staggered Gross-Neveu model including two types of four-point interactions. We use generalized mass terms to split the doublers for both staggered and naive fermions. The phase boundaries derived from the gap equations show that the mass splitting of tastes results in an Aoki phase both in the staggered and naive cases. We also discuss the continuum limit of these models and explore taking the chirally symmetric limit by fine-tuning a mass parameter and two-coupling constants. This supports the idea that in lattice QCD we can derive one- or two-flavor staggered fermions by tuning the mass parameter, which are likely to be less expensive than Wilson fermions in QCD simulation.
Knechtle, Beat; Senn, Oliver; Imoberdorf, Reinhard; Joleska, Irena; Wirth, Andrea; Knechtle, Patrizia; Rosemann, Thomas
2010-01-01
We investigated in 11 female ultra-runners during a 100 km ultra-run, the association between fluid intake and prevalence of exercise-associated hyponatremia in a cross-sectional study. Athletes drank ad libitum and recorded their fluid intake. They competed at 8.0 (1.0) km/h and finished within 762 (91) min. Fluid intake was 4.1 (1.3) L during the race, equal to 0.3 (0.1) L/h. Body mass decreased by 1.5 kg (p< 0.01); pre race body mass was related to speed in the race (r = -0.78, p< 0.05); and change (Delta) in body mass was not associated with speed in the race. Change in body mass was positively (r = 0.70; p< 0.05), and Delta urinary specific gravity negatively (r = -0.67; p< 0.05), correlated to Delta percent total body water. Changes in body mass were not related to fluid intake during the race. Fluid intake was not correlated to running speed and showed no association with either Delta percent total body water nor Delta [Na] in plasma. Fluid intake showed no relationship with both Delta haematocrit and Delta plasma volume. No exercise-associated hyponatremia occurred. Female ultra- runners consuming fluids ad libitum during the race experienced no fluid overload, and ad libitum drinking protects against exercise-associated hyponatremia. The reported higher incidence of exercise-associated hyponatremia in women is not really a gender effect but due to women being more prone to overdrink. PMID:20199991
From the Komar Mass and Entropic Force Scenarios to the Einstein Field Equations on the Ads Brane
NASA Astrophysics Data System (ADS)
Moradpour, H.; Sheykhi, A.
2016-02-01
By bearing the Komar's definition for the mass, together with the entropic origin of gravity in mind, we find the Einstein field equations in ( n + 1)-dimensional spacetime. Then, by reflecting the (4 + 1)-dimensional Einstein equations on the (3 + 1)-hypersurface, we get the Einstein equations onto the 3-brane. The corresponding energy conditions are also addressed. Since the higher dimensional considerations modify the Einstein field equations in the (3 + 1)-dimensions and thus the energy-momentum tensor, we get a relation for the Komar mass on the brane. In addition, the strongness of this relation compared with existing definition for the Komar mass on the brane is addressed.
NASA Astrophysics Data System (ADS)
Albacete, Javier L.; Kovchegov, Yuri V.; Taliotis, Anastasios
2009-03-01
We calculate the total cross section for the scattering of a quark-anti-quark dipole on a large nucleus at high energy for a strongly coupled N = 4 super Yang-Mills theory using AdS/CFT correspondence. We model the nucleus by a metric of a shock wave in AdS5. We then calculate the expectation value of the Wilson loop (the dipole) by finding the extrema of the Nambu-Goto action for an open string attached to the quark and antiquark lines of the loop in the background of an AdS5 shock wave. We find two physically meaningful extremal string configurations. For both solutions we obtain the forward scattering amplitude N for the quark dipole-nucleus scattering. We study the onset of unitarity with increasing center-of-mass energy and transverse size of the dipole: we observe that for both solutions the saturation scale Qs is independent of energy/Bjorken-x and depends on the atomic number of the nucleus as Qs˜A1/3. Finally we observe that while one of the solutions we found corresponds to the pomeron intercept of αP = 2 found earlier in the literature, when extended to higher energy or larger dipole sizes it violates the black disk limit. The other solution we found respects the black disk limit and yields the pomeron intercept of αP = 1.5. We thus conjecture that the right pomeron intercept in gauge theories at strong coupling may be αP = 1.5.
Vector Schwinger Model with a Photon Mass Term with Faddeevian Regularization
NASA Astrophysics Data System (ADS)
Kulshreshtha, Usha; Kulshreshtha, Daya Shankar; Vary, James P.
2015-09-01
In this talk, we consider the vector Schwinger model with a photon mass term with Faddeevian Regularization, describing two-dimensional (2D) electrodynamics with mass-less fermions and study its Hamiltonian and path integral quantization. This theory is seen to be gauge-non-invariant (GNI). We then construct a gauge-invariant (GI) theory corresponding to this GNI theory using the Stueckelberg mechanism and then recover the physical content of the original GNI theory from the newly constructed GI theory under some special gauge-fixing conditions.
Podczeck, Fridrun; Wood, Annette V
2003-05-12
The Peschl-split bed shear tester was utilised to study the formation of different liquid states during wet massing for granulation. Using lactose monohydrate as a model bulking agent the threshold between pendular and funicular state was found to be at about 6% (w/w) of liquid binder added to the wet mass, here a 5% colloidal solution of HPMC in water. The upper limit of the funicular state appeared to be at approximately 15% (w/w) of liquid binder. The threshold values obtained from the shear cell measurements did correlate with values obtained from dried granule characteristics such as granule density and compressive Young's modulus determined by Dynamic Mechanical Analysis. The compressive Young's modulus increased with an increasing density of the wet mass during the shear experiments and decreased with an increase in the angle of internal friction. The results suggest that stiffer granules were a result of densification, not the strength of liquid bridge bond formation. PMID:12711161
Glaciological and geodetic mass balance of ten long-term glaciers in Norway
NASA Astrophysics Data System (ADS)
Andreassen, L. M.; Elvehøy, H.; Kjøllmoen, B.; Engeset, R. V.
2015-11-01
The glaciological and geodetic methods provide independent observations of glacier mass balance. The glaciological method measures the surface mass balance, on a seasonal or annual basis, whereas the geodetic method measures surface, internal and basal mass balances, over a period of years or decades. In this paper, we reanalyse the 10 glaciers with long-term mass balance series in Norway. The reanalysis includes (i) homogenisation of both glaciological and geodetic observation series, (ii) uncertainty assessment, (iii) estimates of generic differences including estimates of internal and basal melt, (iv) validation, and (v) partly calibration of mass balance series. This study comprises an extensive set of data (454 mass balance years, 34 geodetic surveys and large volumes of supporting data, such as metadata and field notes). In total, 21 periods of data were compared and the results show discrepancies between the glaciological and geodetic methods for some glaciers, which in part are attributed to internal and basal ablation and in part to inhomogeneity in the data processing. Deviations were smaller than 0.2 m w.e. a-1 for 12 out of 21 periods. Calibration was applied to seven out of 21 periods, as the deviations were larger than the uncertainty. The reanalysed glaciological series shows a more consistent signal of glacier change over the period of observations than previously reported: six glaciers had a significant mass loss (14-22 m w.e.) and four glaciers were nearly in balance. All glaciers have lost mass after year 2000. More research is needed on the sources of uncertainty, to reduce uncertainties and adjust the observation programmes accordingly. The study confirms the value of carrying out independent high-quality geodetic surveys to check and correct field observations.
Reanalysis of long-term series of glaciological and geodetic mass balance for 10 Norwegian glaciers
NASA Astrophysics Data System (ADS)
Andreassen, Liss M.; Elvehøy, Hallgeir; Kjøllmoen, Bjarne; Engeset, Rune V.
2016-03-01
Glaciological and geodetic methods provide independent observations of glacier mass balance. The glaciological method measures the surface mass balance, on a seasonal or annual basis, whereas the geodetic method measures surface, internal, and basal mass balances, over a period of years or decades. In this paper, we reanalyse the 10 glaciers with long-term mass-balance series in Norway. The reanalysis includes (i) homogenisation of both glaciological and geodetic observation series, (ii) uncertainty assessment, (iii) estimates of generic differences including estimates of internal and basal melt, (iv) validation, and, if needed, (v) calibration of mass-balance series. This study comprises an extensive set of data (484 mass-balance years, 34 geodetic surveys, and large volumes of supporting data, such as metadata and field notes). In total, 21 periods of data were compared and the results show discrepancies between the glaciological and geodetic methods for some glaciers, which are attributed in part to internal and basal ablation and in part to inhomogeneity in the data processing. Deviations were smaller than 0.2 m w.e. a-1 for 12 out of 21 periods. Calibration was applied to 7 out of 21 periods, as the deviations were larger than the uncertainty. The reanalysed glaciological series shows a more consistent signal of glacier change over the period of observations than previously reported: six glaciers had a significant mass loss (14-22 m w.e.) and four glaciers were nearly in balance. All glaciers have lost mass after the year 2000. More research is needed on the sources of uncertainty to reduce uncertainties and adjust the observation programmes accordingly. The study confirms the value of carrying out independent high-quality geodetic surveys to check and correct field observations.
Bending AdS waves with new massive gravity
NASA Astrophysics Data System (ADS)
Ayón-Beato, Eloy; Giribet, Gaston; Hassaïne, Mokhtar
2009-05-01
We study AdS-waves in the three-dimensional new theory of massive gravity recently proposed by Bergshoeff, Hohm, and Townsend. The general configuration of this type is derived and shown to exhibit different branches, with different asymptotic behaviors. In particular, for the special fine tuning m2 = ±1/(2l2), solutions with logarithmic fall-off arise, while in the range m2 > -1/(2l2), spacetimes with Schrödinger isometry group are admitted as solutions. Spacetimes that are asymptotically AdS3, both for the Brown-Henneaux and for the weakened boundary conditions, are also identified. The metric function that characterizes the profile of the AdS-wave behaves as a massive excitation on the spacetime, with an effective mass given by meff2 = m2-1/(2l2). For the critical value m2 = -1/(2l2), the value of the effective mass precisely saturates the Breitenlohner-Freedman bound for the AdS3 space where the wave is propagating on. The analogies with the AdS-wave solutions of topologically massive gravity are also discussed. Besides, we consider the coupling of both massive deformations to Einstein gravity and find the exact configurations for the complete theory, discussing all the different branches exhaustively. One of the effects of introducing the Chern-Simons gravitational term is that of breaking the degeneracy in the effective mass of the generic modes of pure New Massive Gravity, producing a fine structure due to parity violation. Another effect is that the zoo of exact logarithmic specimens becomes considerably enlarged.
Octet baryon masses and sigma terms from an SU(3) chiral extrapolation
Young, Ross; Thomas, Anthony
2009-01-01
We analyze the consequences of the remarkable new results for octet baryon masses calculated in 2+1- avour lattice QCD using a low-order expansion about the SU(3) chiral limit. We demonstrate that, even though the simulation results are clearly beyond the power-counting regime, the description of the lattice results by a low-order expansion can be significantly improved by allowing the regularisation scale of the effective field theory to be determined by the lattice data itself. The model dependence of our analysis is demonstrated to be small compared with the present statistical precision. In addition to the extrapolation of the absolute values of the baryon masses, this analysis provides a method to solve the difficult problem of fine-tuning the strange-quark mass. We also report a determination of the sigma terms for all of the octet baryons, including an accurate value of the pion-nucleon sigma term and the first determination of the strangeness sigma term based on 2+1-flavour l
Du, Yanshan; Li, Qiang; Wu, Chunmin; Zhang, Yan
2015-04-01
A method for rapid screening and quantification of 11 antidiabetics (nateglinide, pioglitazone hydrochloride, gliquidone, gliclazide, glipizide, glibenclamide, metformin hydrochloride, repaglinide, phenformin hydrochloride, rosiglitazone hydrochloride, glimepiride) illegally added in health care products by ultra performance liquid chromatography (UPLC)-quadrupole/ electrostatic field orbitrap mass spectrometry was established. The samples were extracted with methanol, and separated on an Agilent Poroshell 120 SB-C18 column (100 mm x 4.6 mm, 2.7 µm) with acetonitrile-10 mmol/L ammonium acetate solution as mobile phases by gradient elution. The positive mode was used in the MS detection. The resolution of the precursor mass was 70,000, while the resolution of the product mass was 17,500. The results indicated that the linearity of all the 11 antidiabetics ranged from 0.005 mg/L to 0.5 mg/L with the correlation coefficients greater than 0.99. The limits of detection were confirmed by spiked samples, and were between 2.7 and 5.1 µg/kg for the 11 antidiabetics. The recoveries were in the range of 87.3% to 98.3%, with the relative standard deviations in the range of 2.18%-5.21%. This method is accurate, simple and rapid, and can be used in rapid screening and quantitative analysis of the 11 illegally added antidiabetics in health care products. PMID:26292406
NASA Astrophysics Data System (ADS)
Yang, F.-L.
2010-12-01
This work re-examines the potential flow theory for a sphere in normal approach to a wall, based on the classical results derived by Lamb [Hydrodynamics (Dover, New York, 1932)] and Milne-Thomson [Theoretical Hydrodynamics, 5th ed. (Dover, New York, 1968)]. These authors generated an expression in which the kinetic energy for a sphere in an unbounded fluid is augmented by a wall correction function in terms of an infinite series that depends on the scaled center-to-wall distance, h∗=h/a, with a denoting the sphere radius. By truncating the series at the order of h∗-3, the resulting one-term correction function, 3/8h∗-3, is widely employed to approximate the wall-amplified added mass coefficient, CAM(h ∗), in multiphase flow research. Nonetheless, this work shows that this one-term correction deviates greatly from corrections including higher order terms when the interstitial gap drops below the half sphere radius. Thus, an explicit formula is developed, for all h∗, using a near-wall Padé approximation, an intermediate bridging function, and a far-field approximation. This proposed formula provides an efficient and reasonable approximation to the infinite series and thus may serve as an improved wall correction function as compared to the one-term formula. The developed formula is applied to compute the unsteady approach of a nonrotating sphere toward a wall in a viscous fluid at low Reynolds number condition. In addition to Brenner's wall correction on the quasisteady viscous force [H. Brenner, "The slow motion of a sphere through a viscous fluid towards a plane surface," Chem. Eng. Sci. 16, 242 (1961)], the current formula is employed to modify both the added mass coefficient, from 1/2, and the history force. This latter force is modified by integrating the wall-modified potential flow theory with the boundary layer theory. If the one-term correction is used in the equation of motion, underestimation of the sphere motion and the force magnitudes are
Nonuniqueness of the Fierz-Pauli mass term for a nonsymmetic tensor
NASA Astrophysics Data System (ADS)
Dalmazi, D.
2012-12-01
Starting with a description of massive spin-2 particles in D=4 in terms of a mixed symmetry tensor T[μν]ρ without a totally antisymmetric part (T[[μν]ρ]=0), we obtain a dual model in terms of a nonsymmetric tensor eμν. The model is of second order in derivatives, and its mass term (eμνeνμ+ce2) contains an arbitrary real parameter c. Remarkably, it is free of ghosts for any real value of c and describes a massive spin-2 particle as expected from duality. The antisymmetric part e[μν] plays the role of auxiliary fields, vanishing on shell. In the massless case the model describes a massless spin-2 particle without ghosts.
Evaluation of three long term mass balance records in Jotunheimen, southern Norway
NASA Astrophysics Data System (ADS)
Andreassen, Liss M.
2013-04-01
The accuracy of glacier surface mass-balance measurements depends on both the accuracy of the point observations and inter- and extrapolation of point values to spatially distributed values. Long series of measurements will seldom be perfectly homogeneous because of changes in personnel and procedure, and as there will be changes in glacier area (and elevation) when averaging the data. The Jotunheimen massif is the highest area in mainland Norway. Direct surface mass balance has been measured at Storbreen since 1949 and Hellstugubreen and Gråsubreen since 1962. These three mountain glaciers are reference glaciers of the World Glacier Monitoring Service. Four more glaciers in Jotunheimen were measured for shorter periods in the 1960/1970s. Moreover, measurements started on a small ice patch in 2010. The reference glaciers have been mapped repeatedly since measurements began, latest by laser scanning in 2009. The geodetic method has been used to calculate the cumulative surface mass balance. In this study the direct and geodetic mass balance results are presented and evaluated. Measurements reveal a remarked mass balance gradient in this region with smaller mass turnover towards east. All three long term glaciers have had a cumulative mass deficit since measurements began; over 1962-2010 the mean surface mass balance was -0.34 m w.e./a. The mass deficit has accelerated over the past decade, and the mean mass balance over 2001-2010 was -0.84 m w.e./a. Storbreen has lost about 1/5 of its volume since measurements began in 1949. Results reveal that the geodetic and direct measurements compare well for the glaciers, also for the latest mapping period 1997-2009, although discrepancies occur in some periods. Calibration and correction of the direct records with the geodetic results may be appropriate for some periods. The glacier changes of the three reference glaciers are finally compared with results from other glaciers in southern Norway for evaluation of the local and
Rheological Characteristics of Weak Rock Mass and Effects on the Long-Term Stability of Slopes
NASA Astrophysics Data System (ADS)
Yang, Tianhong; Xu, Tao; Liu, Hongyuan; Zhang, Chunming; Wang, Shanyong; Rui, Yongqin; Shen, Li
2014-11-01
The creep deformation behavior of the northern slope of an open-pit mine is introduced. Direct shear creep tests are then conducted for the samples taken from the northern slope to study the rheological characteristics of the rock mass. The experimental results are analyzed afterwards using an empirical method to develop a rheological model for the rock mass. The proposed rheological model is finally applied to understand the creep behavior of the northern slope, predict the long-term stability, and guide appropriate measures to be taken at suitable times to increase the factor of safety to ensure stability. Through this study, a failure criterion is proposed to predict the long-term stability of the slope based on the rheological characteristics of the rock mass and a critical deformation rate is adopted to determine when appropriate measures should be taken to ensure slope stability. The method has been successfully applied for stability analysis and engineering management of the toppling and slippage of the northern slope of the open-pit mine. This success in application indicates that it is theoretically accurate, practically feasible, and highly cost-effective.
Albacete, Javier L.; Kovchegov, Yuri V.; Taliotis, Anastasios
2009-03-23
We calculate the total cross section for the scattering of a quark-anti-quark dipole on a large nucleus at high energy for a strongly coupled N = 4 super Yang-Mills theory using AdS/CFT correspondence. We model the nucleus by a metric of a shock wave in AdS{sub 5}. We then calculate the expectation value of the Wilson loop (the dipole) by finding the extrema of the Nambu-Goto action for an open string attached to the quark and antiquark lines of the loop in the background of an AdS{sub 5} shock wave. We find two physically meaningful extremal string configurations. For both solutions we obtain the forward scattering amplitude N for the quark dipole-nucleus scattering. We study the onset of unitarity with increasing center-of-mass energy and transverse size of the dipole: we observe that for both solutions the saturation scale Q{sub s} is independent of energy/Bjorken-x and depends on the atomic number of the nucleus as Q{sub s}{approx}A{sup 1/3}. Finally we observe that while one of the solutions we found corresponds to the pomeron intercept of {alpha}{sub P} = 2 found earlier in the literature, when extended to higher energy or larger dipole sizes it violates the black disk limit. The other solution we found respects the black disk limit and yields the pomeron intercept of {alpha}{sub P} = 1.5. We thus conjecture that the right pomeron intercept in gauge theories at strong coupling may be {alpha}{sub P} = 1.5.
CFT adapted gauge invariant formulation of massive arbitrary spin fields in AdS
NASA Astrophysics Data System (ADS)
Metsaev, R. R.
2010-01-01
Using Poincaré parametrization of AdS space, we study massive totally symmetric arbitrary spin fields in AdS space of dimension greater than or equal to four. CFT adapted gauge invariant formulation for such fields is developed. Gauge symmetries are realized by using Stueckelberg formulation of massive fields. We demonstrate that the mass parameter, curvature and radial coordinate contributions to the gauge transformation and Lagrangian of the AdS massive fields can be expressed in terms of ladder operators. Three representations for the Lagrangian are discussed. Realization of the global AdS symmetries in the conformal algebra basis is obtained. Modified de Donder gauge leading to simple gauge fixed Lagrangian is found. The modified de Donder gauge leads to decoupled equations of motion which can easily be solved in terms of the Bessel function. New simple representation for gauge invariant Lagrangian of massive (A)dS field in arbitrary coordinates is obtained. Light-cone gauge Lagrangian of massive AdS field is also presented.
Ellis, Wade C; Lewis, Charlotte R; Openshaw, Anna P; Farnsworth, Paul B
2016-09-01
We demonstrate the effectiveness of using hydrogen-doped argon as the support gas for the dielectric barrier discharge (DBD) ambient desorption/ionization (ADI) source in mass spectrometry. Also, we explore the chemistry responsible for the signal enhancement observed when using both hydrogen-doped argon and hydrogen-doped helium. The hydrogen-doped argon was tested for five analytes representing different classes of molecules. Addition of hydrogen to the argon plasma gas enhanced signals for gas-phase analytes and for analytes coated onto glass slides in positive and negative ion mode. The enhancements ranged from factors of 4 to 5 for gas-phase analytes and factors of 2 to 40 for coated slides. There was no significant increase in the background. The limit of detection for caffeine was lowered by a factor of 79 using H2/Ar and 2 using H2/He. Results are shown that help explain the fundamental differences between the pure-gas discharges and those that are hydrogen-doped for both argon and helium. Experiments with different discharge geometries and grounding schemes indicate that observed signal enhancements are strongly dependent on discharge configuration. Graphical Abstract ᅟ. PMID:27380389
NASA Astrophysics Data System (ADS)
Ellis, Wade C.; Lewis, Charlotte R.; Openshaw, Anna P.; Farnsworth, Paul B.
2016-09-01
We demonstrate the effectiveness of using hydrogen-doped argon as the support gas for the dielectric barrier discharge (DBD) ambient desorption/ionization (ADI) source in mass spectrometry. Also, we explore the chemistry responsible for the signal enhancement observed when using both hydrogen-doped argon and hydrogen-doped helium. The hydrogen-doped argon was tested for five analytes representing different classes of molecules. Addition of hydrogen to the argon plasma gas enhanced signals for gas-phase analytes and for analytes coated onto glass slides in positive and negative ion mode. The enhancements ranged from factors of 4 to 5 for gas-phase analytes and factors of 2 to 40 for coated slides. There was no significant increase in the background. The limit of detection for caffeine was lowered by a factor of 79 using H2/Ar and 2 using H2/He. Results are shown that help explain the fundamental differences between the pure-gas discharges and those that are hydrogen-doped for both argon and helium. Experiments with different discharge geometries and grounding schemes indicate that observed signal enhancements are strongly dependent on discharge configuration.
NASA Astrophysics Data System (ADS)
Ellis, Wade C.; Lewis, Charlotte R.; Openshaw, Anna P.; Farnsworth, Paul B.
2016-07-01
We demonstrate the effectiveness of using hydrogen-doped argon as the support gas for the dielectric barrier discharge (DBD) ambient desorption/ionization (ADI) source in mass spectrometry. Also, we explore the chemistry responsible for the signal enhancement observed when using both hydrogen-doped argon and hydrogen-doped helium. The hydrogen-doped argon was tested for five analytes representing different classes of molecules. Addition of hydrogen to the argon plasma gas enhanced signals for gas-phase analytes and for analytes coated onto glass slides in positive and negative ion mode. The enhancements ranged from factors of 4 to 5 for gas-phase analytes and factors of 2 to 40 for coated slides. There was no significant increase in the background. The limit of detection for caffeine was lowered by a factor of 79 using H2/Ar and 2 using H2/He. Results are shown that help explain the fundamental differences between the pure-gas discharges and those that are hydrogen-doped for both argon and helium. Experiments with different discharge geometries and grounding schemes indicate that observed signal enhancements are strongly dependent on discharge configuration.
High-contrast Imaging of Intermediate-mass Giants with Long-term Radial Velocity Trends
NASA Astrophysics Data System (ADS)
Ryu, Tsuguru; Sato, Bun’ei; Kuzuhara, Masayuki; Narita, Norio; Takahashi, Yasuhiro H.; Uyama, Taichi; Kudo, Tomoyuki; Kusakabe, Nobuhiko; Hashimoto, Jun; Omiya, Masashi; Harakawa, Hiroki; Abe, Lyu; Ando, Hiroyasu; Brandner, Wolfgang; Brandt, Timothy D.; Carson, Joseph C.; Currie, Thayne; Egner, Sebastian; Feldt, Markus; Goto, Miwa; Grady, Carol A.; Guyon, Olivier; Hayano, Yutaka; Hayashi, Masahiko; Hayashi, Saeko S.; Hełminiak, Krzysztof G.; Henning, Thomas; Hodapp, Klaus W.; Ida, Shigeru; Ishii, Miki; Itoh, Yoichi; Iye, Masanori; Izumiura, Hideyuki; Janson, Markus; Kambe, Eiji; Kandori, Ryo; Knapp, Gillian R.; Kokubo, Eiichiro; Kwon, Jungmi; Matsuo, Taro; Mayama, Satoshi; McElwain, Michael W.; Mede, Kyle; Miyama, Shoken; Morino, Jun-Ichi; Moro-Martin, Amaya; Nishimura, Tetsuo; Pyo, Tae-Soo; Serabyn, Eugene; Suenaga, Takuya; Suto, Hiroshi; Suzuki, Ryuji; Takami, Michihiro; Takato, Naruhisa; Takeda, Yoichi; Terada, Hiroshi; Thalmann, Christian; Turner, Edwin L.; Watanabe, Makoto; Wisniewski, John; Yamada, Toru; Yoshida, Michitoshi; Takami, Hideki; Usuda, Tomonori; Tamura, Motohide
2016-07-01
A radial velocity (RV) survey for intermediate-mass giants has been in operation for over a decade at Okayama Astrophysical Observatory (OAO). The OAO survey has revealed that some giants show long-term linear RV accelerations (RV trends), indicating the presence of outer companions. Direct-imaging observations can help clarify what objects generate these RV trends. We present the results of high-contrast imaging observations of six intermediate-mass giants with long-term RV trends using the Subaru Telescope and HiCIAO camera. We detected co-moving companions to γ Hya B ({0.61}-0.14+0.12{M}ȯ ), HD 5608 B (0.10+/- 0.01{M}ȯ ), and HD 109272 B (0.28+/- 0.06{M}ȯ ). For the remaining targets (ι Dra, 18 Del, and HD 14067), we exclude companions more massive than 30–60 M Jup at projected separations of 1″–7″. We examine whether these directly imaged companions or unidentified long-period companions can account for the RV trends observed around the six giants. We find that the Kozai mechanism can explain the high eccentricity of the inner planets ι Dra b, HD 5608 b, and HD 14067 b.
Immune Response Gene Profiles in the Term Placenta Depend Upon Maternal Muscle Mass
O’Tierney, P. F.; Lewis, R. M.; McWeeney, S. K.; Hanson, M. A.; Inskip, H. M.; Morgan, T. K.; Barker, D. J.; Bagby, G.; Cooper, C.; Godfrey, K. M.
2012-01-01
Maternal thinness leads to metabolic challenges in the offspring, but it is unclear whether reduced maternal fat mass or muscle mass drives these metabolic changes. Recently, it has been shown that low maternal muscle mass—as measured by arm muscle area (AMA)—is associated with depressed nutrient transport to the fetus. To determine the role of maternal muscle mass on placental function, we analyzed the gene expression profiles of 30 human placentas over the range of AMA (25.2-90.8 cm2) from uncomplicated term pregnancies from the Southampton Women’s Survey cohort. Eighteen percent of the ∼60 genes that were highly expressed in less muscular women were related to immune system processes and the interferon-γ (IFNG) signaling pathway in particular. Those transcripts related to the IFNG pathway included IRF1, IFI27, IFI30, and GBP6. Placentas from women with low muscularity are, perhaps, more sensitive to the effects of inflammatory cytokines than those from more muscular women. PMID:22534332
Direct determinations of the nucleon and pion σ terms at nearly physical quark masses
NASA Astrophysics Data System (ADS)
Bali, Gunnar S.; Collins, Sara; Richtmann, Daniel; Schäfer, Andreas; Söldner, Wolfgang; Sternbeck, André; RQCD Collaboration
2016-05-01
We present a high statistics study of the pion and nucleon light and strange quark sigma terms using Nf=2 dynamical nonperturbatively improved clover fermions with a range of pion masses down to mπ˜150 MeV and several volumes, L mπ=3.4 up to 6.7, and lattice spacings, a =0.06 - 0.08 fm , enabling a study of finite volume and discretization effects for mπ≳260 MeV . Systematics are found to be reasonably under control. For the nucleon we obtain σπ N=35 (6 ) MeV and σs=35 (12 ) MeV , or equivalently in terms of the quark fractions, fTu=0.021 (4 ) , fTd=0.016 (4 ) and fTs=0.037 (13 ) , where the errors include estimates of both the systematic and statistical uncertainties. These values, together with perturbative matching in the heavy quark limit, lead to fTc=0.075(4 ), fT b=0.072 (2 ) and fT t=0.070 (1 ). In addition, through the use of the (inverse) Feynman-Hellmann theorem our results for σπ N are shown to be consistent with the nucleon masses determined in the analysis. For the pion we implement a method which greatly reduces excited state contamination to the scalar matrix elements from states traveling across the temporal boundary. This enables us to demonstrate the Gell-Mann-Oakes-Renner expectation σπ=mπ/2 over our range of pion masses.
The impact of Saharan dust events on long-term glacier mass balance in the Alps
NASA Astrophysics Data System (ADS)
Bauder, A.; Gabbi, J.; Huss, M.; Schwikowski, M.
2014-12-01
Saharan dust falls are frequently observed in the Alpine region and are easily recognized by the unique yellowish coloration of the snow surface. Such Saharan dust events contribute to a large part to the total mineral dust deposited in snow and impact the surface energy budget by reducing the snow and ice albedo. In this study we investigate the long-term effect of such Saharan dust events on the surface albedo and the glacier's mass balance. The analysis is performed over the period 1914-2013 for two field sites on Claridenfirn, Swiss Alps, where an outstanding 100-year record of seasonal mass balance measurements is available. Based on the detailed knowledge about the mass balance, annual melt and accumulation rates are derived. A firn/ice core drilled at the glacier saddle of Colle Gnifetti (Swiss Alps) provides information on the impurity concentration in precipitation over the last century. A mass balance model combined with a parameterization for snow and ice albedo based on the specific surface area of snow and the snow impurity concentration is employed to assess the dust-albedo feedback. In order to track the position and thickness of snow layers a snow density model is implemented. Atmospheric dust enters the system of snow layers by precipitation and remains in the corresponding layer as long as there is no melt. When melt occurs, the water-insoluble part of the dust of the melted snow is supposed to accumulate in the top surface layer. The upper site has experienced only positive net mass balance and dust layers are continuously buried so that the impact of strong Saharan dust events is mainly restricted to the corresponding year. In the case of the lower site, the surface albedo is more strongly influenced by dust events of previous years due to periods with negative mass balances. Model results suggest that the enhanced melting in the 1940s yield even higher dust concentrations in 1947 compared to years with exceptional high Saharan dust deposition
Hu, Tingting; Qu, Xiaoyu; Kang, Mingqin; Song, Qinglian; Yang, Lu; Zhao, Yunhui; Zhang, Daihui
2015-08-01
A method was established for rapid screening and quantifying 11 illegally added anti-impotence preparations (yohimbine, acetildenafil, nor-acetildenafil, homosildenafil, hydroxy-homosildenafil, sildenafil, vardenafil, thioaildenafil, tadalafil, pseudovardenafil, dapoxetine) in health care products by high performance liquid chromatography-high resolution mass spectrometry. The samples were extracted with methanol and analyzed by positive mode in the MS detection. The results showed that the limits of detection were 25.0 ng/mLexcept for nor-acetildenafil (5.0 ng/mL), the linear ranges were 5.0-200.0 ng/mL except for nor-acetildenafil (25.0-500.0 ng/mL) with the correlation coefficients not less than 0.999 0. The recoveries were in the range of 82.0%-105.9% with the relative standard deviations of 4.7%-16.5%. This method is accurate, simple and rapid, and can be used in rapid screening and quantitative analysis of the 11 illegally added anti-impotence in health care products. PMID:26749869
Song, Ningning; Zhang, Keming; Liu, Xianghong; Sang, Tong; Sun, Yu; Teng, Nanyan
2015-10-01
An ultra high performance liquid chromatography-tandem mass spectrometry method with modified QuEChERS procedure for sample preparation was developed for the simultaneous determination of 12 chemical drugs (chlorpheniramine, piroxicam, α-asarone etc) illegally added in herbal tea. The samples were extracted with acetonitrile, purified with QuEChERS procedure and filtrated by 0.22 μm microporous filters. The separation was carried on an XBridge BEH C18 column (100 mm x 2.1 mm, 3.5 μm) by a gradient elution using acetonitrile/0.1% (v/v) formic acid aqueous solution as mobile phases. The analytes were detected by tandem mass spectrometry with positive electrospray ionization (ESI+) in multiple reaction monitoring (MRM) mode, and quantified by external standard calibration method. The correlation coefficients of the standard calibration curves for the 12 analytes were all above 0.997. The limits of detection ranged from 0.1 μg/L to 2.1 μg/L, and the limits of quantification ranged from 0.4 g/L to 8.0 μg/L. The average recoveries of the 12 analytes spiked at three levels in blank samples ranged from 62.7% to 95.2% with the RSDs from 1.3% to 10.8%. The samples bought from markets were screened, and some of the samples showed positive for these analytes. The method developed is easy to operate, sensitive, and with good purification effect. It can be applied to the rapid determination of the 12 chemical drugs illegally added in herbal tea. PMID:26930958
AdS orbifolds and Penrose limits
Alishahiha, Mohsen; Sheikh-Jabbari, Mohammad M.; Tatar, Radu
2002-12-09
In this paper we study the Penrose limit of AdS{sub 5} orbifolds. The orbifold can be either in the pure spatial directions or space and time directions. For the AdS{sub 5}/{Lambda} x S{sup 5} spatial orbifold we observe that after the Penrose limit we obtain the same result as the Penrose limit of AdS{sub 5} x S{sup 5}/{Lambda}. We identify the corresponding BMN operators in terms of operators of the gauge theory on R x S{sup 3}/{Lambda}. The semi-classical description of rotating strings in these backgrounds have also been studied. For the spatial AdS orbifold we show that in the quadratic order the obtained action for the fluctuations is the same as that in S{sup 5} orbifold, however, the higher loop correction can distinguish between two cases.
Light-Front BRST Quantization of the Vector Schwinger Model with a Photon Mass Term
NASA Astrophysics Data System (ADS)
Kulshreshtha, Usha; Kulshreshtha, Daya Shankar; Vary, James P.; Sharma, Lalit Kumar
2014-12-01
Vector Schwinger model with a mass term for the photon, describing 2D electrodynamics with mass-less fermions, studied by us recently (UK, Mod. Phys. Lett A22, 2993 (2007), PoS LC2008, 008 (2008), UK and DSK, Int. J. Mod. Phys. A22, 6183 (2007), UK, Mod. Phys. Lett A27, 1250157 (2012)), represents a new class of models. This theory becomes gauge-invariant when studied on the light-front. This is in contrast to the instant-form theory which is gauge-non-invariant. The light-front Hamiltonian and path integral quantization of this theory has been studied recently by one of us (UK, Mod. Phys. Lett. A27 (No. 27) 1250157 (2012)). In the present work we study the light-front Becchi-Rouet-Stora and Tyutin (BRST) quantization of this theory under appropriate light-cone BRST gauge-fixing. Here the BRST (gauge) symmetry of the theory is maintained even under BRST-gauge-fixing which is in contrast to its Hamiltonian and path integral quantization where the gauge symmetry of the theory necessarily gets broken under gauge-fixing.
NASA Astrophysics Data System (ADS)
Kulshreshtha, Usha; Kulshreshtha, Daya Shankar; Vary, James P.
2016-07-01
In this talk, we study the light-front quantization of the vector Schwinger model with photon mass term in Faddeevian Regularization, describing two-dimensional electrodynamics with mass-less fermions but with a mass term for the U(1) gauge field. This theory is gauge-non-invariant (GNI). We construct a gauge-invariant (GI) theory using Stueckelberg mechanism and then recover the physical content of the original GNI theory from the newly constructed GI theory under some special gauge-fixing conditions (GFC's). We then study LFQ of this new GI theory.
Thierry, Anne-Mathilde; Ropert-Coudert, Yan; Raclot, Thierry
2013-01-01
Study of physiological mechanisms can help us to understand how animals respond to changing environmental conditions. In particular, stress hormones (i.e. glucocorticoids, such as corticosterone) are described as mediating resource allocation, allowing animals to adjust their physiology and behaviour to predictable and unpredictable changes in the environment. In this study, we investigated the effects of an experimental increase in baseline corticosterone levels on the breeding effort and the reproductive output of chick-rearing male Adélie penguins (Pygoscelis adeliae). The number of chicks per nest, their body mass, and their size were monitored throughout the study. Direct observations allowed measurement of the time spent foraging at sea and caring for the young on the nest. At the end of the treatment, blood samples were collected for isotope analysis. Although all birds raised at least one chick, reproductive output was decreased by 42% in corticosterone-treated birds compared with control birds. The increase in corticosterone levels during the guard stage did not affect the mass of surviving chicks or the brood mass at fledging. Corticosterone-treated males spent on average 21% more time at the nest than control birds. However, the duration of foraging trips was similar between both groups. In addition, the similarity of isotopic signatures suggests that both groups foraged at similar locations and ingested the same prey species. The detailed on-land behaviour of birds should be examined in further studies to clarify the possible links between corticosterone levels, brooding time, and reproductive output. Understanding the relationships between glucocorticoids, fitness, and ultimately population dynamics is fundamental to enabling conservation physiology as a discipline to be successful in helping to manage species of conservation concern. PMID:27293591
Aspects of warped AdS3/CFT2 correspondence
NASA Astrophysics Data System (ADS)
Chen, Bin; Zhang, Jia-Ju; Zhang, Jian-Dong; Zhong, De-Liang
2013-04-01
In this paper we apply the thermodynamics method to investigate the holographic pictures for the BTZ black hole, the spacelike and the null warped black holes in three-dimensional topologically massive gravity (TMG) and new massive gravity (NMG). Even though there are higher derivative terms in these theories, the thermodynamics method is still effective. It gives consistent results with the ones obtained by using asymptotical symmetry group (ASG) analysis. In doing the ASG analysis we develop a brute-force realization of the Barnich-Brandt-Compere formalism with Mathematica code, which also allows us to calculate the masses and the angular momenta of the black holes. In particular, we propose the warped AdS3/CFT2 correspondence in the new massive gravity, which states that quantum gravity in the warped spacetime could holographically dual to a two-dimensional CFT with {c_R}={c_L}=24 /{Gm{β^2√{{2( {21-4{β^2}} )}}}}.
Bernstein, David M.; Rogers, Rick; Sepulveda, Rosalina; Kunzendorf, Peter; Bellmann, Bernd; Ernst, Heinrich; Phillips, James I.
2014-04-01
Chrysotile has been frequently used in the past in manufacturing brakes and continues to be used in brakes in many countries. This study was designed to provide an understanding of the biokinetics and potential toxicology following inhalation of brake dust following short term exposure in rats. The deposition, translocation and pathological response of brake dust derived from brake pads manufactured with chrysotile were evaluated in comparison to the amphibole, crocidolite asbestos. Rats were exposed by inhalation 6 h/day for 5 days to either brake dust obtained by sanding of brake-drums manufactured with chrysotile, a mixture of chrysotile and the brake dust or crocidolite asbestos. No significant pathological response was observed at any time point in either the brake dust or chrysotile/brake dust exposure groups. The long chrysotile fibers (> 20 μm) cleared quickly with T{sub 1/2} estimated as 30 and 33 days, respectively in the brake dust and the chrysotile/brake dust exposure groups. In contrast, the long crocidolite fibers had a T{sub 1/2} > 1000 days and initiated a rapid inflammatory response in the lung following exposure resulting in a 5-fold increase in fibrotic response within 91 days. These results provide support that brake dust derived from chrysotile containing brake drums would not initiate a pathological response in the lung following short term inhalation. - Highlights: • We evaluated brake dust w/wo added chrysotile in comparison to crocidolite asbestos. • Persistence, translocation, pathological response in the lung and pleural cavity. • Chrysotile cleared rapidly from the lung while the crocidolite asbestos persisted. • No significant pathology observed at any time point in the brake-dust groups. • Crocidolite produced pathological response - Wagner 4 interstitial fibrosis by 32d.
ERIC Educational Resources Information Center
UCLA IDEA, 2012
2012-01-01
Value added measures (VAM) uses changes in student test scores to determine how much "value" an individual teacher has "added" to student growth during the school year. Some policymakers, school districts, and educational advocates have applauded VAM as a straightforward measure of teacher effectiveness: the better a teacher, the better students…
Long-term monitoring of rock mass properties in the underground excavation
NASA Astrophysics Data System (ADS)
Vilhelm, Jan; Jirků, Jaroslav; Slavík, Lubomír; Bárta, Jaroslav
2015-04-01
It is generally agreed today that hazardous waste should be placed in repositories hundreds of meters below the Earth's surface. In our research we deal with the long-term monitoring of the underground excavation by seismic and electrical resistivity measurements. Permanent measuring system was developed and installed at the Bedřichov gallery test site (northern Bohemia). The gallery was excavated using TBM (Tunnel Boring Machine) in granitic rocks. Realized repeated measurements include ultrasonic time of flight measurement and electrical resistivity tomography (ERT). The seismic measurements are performed by pulse-transmission technique directly on the rock wall using one seismic source and three receivers in the distances of 1, 2 and 3 m. The main emphasis is devoted to P-waves; however, recording of full waveform enables analyzing of S- waves and other types of waves as well. The comparison of repeated measurements is used for an assessment of changes in seismic velocities with very high-accuracy. The repetition rate of measurements can be selected from seconds; however such fast changes in the rock mass are unexpected. The ERT measurement is performed on the same rock wall using 48 electrodes. The spacing between electrodes is 20 centimeters. The conductivity of undisturbed granitic rocks is extremely low. Therefore the observed local increase of conductivity can be associated with joints and fractures saturated with water, resulting in their ionic conductivity. Repeated ERT measurement can reveal some changes in the rock mass. Due to time requirements of ERT measurement the repetition rate can be about three hours. The data collected by measuring system is transferred by means of computer network and can be accessed via internet. This contribution deals with preliminary results gained so far during the testing of developed monitoring system. Acknowledgments: This work was partially supported by the Technology Agency of the Czech Republic, project No. TA
Normative Data for Bone Mass in Healthy Term Infants from Birth to 1 Year of Age
Gallo, Sina; Vanstone, Catherine A.; Weiler, Hope A.
2012-01-01
For over 2 decades, dual-energy X-ray absorptiometry (DXA) has been the gold standard for estimating bone mineral density (BMD) and facture risk in adults. More recently DXA has been used to evaluate BMD in pediatrics. However, BMD is usually assessed against reference data for which none currently exists in infancy. A prospective study was conducted to assess bone mass of term infants (37 to 42 weeks of gestation), weight appropriate for gestational age, and born to healthy mothers. The group consisted of 33 boys and 26 girls recruited from the Winnipeg Health Sciences Center (Manitoba, Canada). Whole body (WB) as well as regional sites of the lumbar spine (LS 1–4) and femur was measured using DXA (QDR 4500A, Hologic Inc.) providing bone mineral content (BMC) for all sites and BMD for spine. During the year, WB BMC increased by 200% (76.0 ± 14.2 versus 227.0 ± 29.7 g), spine BMC by 130% (2.35 ± 0.42 versus 5.37 ± 1.02 g), and femur BMC by 190% (2.94 ± 0.54 versus 8.50 ± 1.84 g). Spine BMD increased by 14% (0.266 ± 0.044 versus 0.304 ± 0.044 g/cm2) during the year. This data, representing the accretion of bone mass during the first year of life, is based on a representative sample of infants and will aid in the interpretation of diagnostic DXA scans by researchers and health professionals. PMID:23091773
Massive quiver matrix models for massive charged particles in AdS
NASA Astrophysics Data System (ADS)
Asplund, Curtis T.; Denef, Frederik; Dzienkowski, Eric
2016-01-01
We present a new class of N=4 supersymmetric quiver matrix models and argue that it describes the stringy low-energy dynamics of internally wrapped D-branes in four-dimensional anti-de Sitter (AdS) flux compactifications. The Lagrangians of these models differ from previously studied quiver matrix models by the presence of mass terms, associated with the AdS gravitational potential, as well as additional terms dictated by supersymmetry. These give rise to dynamical phenomena typically associated with the presence of fluxes, such as fuzzy membranes, internal cyclotron motion and the appearance of confining strings. We also show how these models can be obtained by dimensional reduction of four-dimensional supersymmetric quiver gauge theories on a three-sphere.
Huang, Chiung-Chun; Chen, Chien-Chung; Liang, Ying-Ching; Hsu, Kuei-Sen
2014-08-01
The intercalated cell masses (ITCs) of the amygdala are clusters of GABAergic interneurons that surround the basolateral complex of the amygdala. ITCs have been increasingly implicated in the acquisition and extinction of conditioned fear responses, but the underlying cellular mechanisms remain unexplored. Here, we report that repetitive stimulation of lateral amygdala (LA) afferents with a modified theta burst stimulation (TBS) protocol and induces long-term potentiation (LTP) of excitatory synapses onto medial paracapsular ITC (Imp) neurons. This TBS-induced LTP is; (1) induced and expressed post-synaptically, (2) involves a rise in post-synaptic Ca2+ and the activation of NR2B-containing N-methyl-D-aspartate receptors (NMDARs), (3) dependent on calcium/calmodulin-dependent protein kinase II and cAMP-dependent protein kinase activation, and (4) associated with increased exocytotic delivery of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPARs) to the post-synaptic membrane. Remarkably, auditory fear conditioning led to a persistent increase in AMPAR/NMDAR ratio of glutamatergic synaptic currents and occluded TBS-induced LTP at LA-Imp synapses. Furthermore, extinction training rescued the effect of fear conditioning on AMPAR/NMDAR ratio and LTP induction. These results show that a prominent form of LTP can be elicited at LA-Imp synapses and suggest that this synaptic plasticity may contribute to the expression of fear conditioning. PMID:24556032
Wolffenbuttel, B H R; Van Gaal, L; Durán-Garcia, S; Han, J
2016-08-01
This post hoc analysis assessed the evidence behind common reimbursement practices by evaluating the relationship of body mass index (BMI) ranges (<30, 30-35 and >35 kg/m(2) ) with treatment effects of exenatide twice daily among patients with type 2 diabetes. Patients received exenatide twice daily added to insulin glargine in two 30-week studies (exenatide twice daily vs insulin lispro, n = 627; exenatide twice daily vs placebo, n = 259). No association of baseline BMI with changes in efficacy variables was observed. Glycated haemoglobin (HbA1c) reductions were significant (p < 0.0001) and similar across BMI range groups in the lispro-comparator study and greater for exenatide versus placebo in the placebo-controlled study. Significant weight loss occurred with exenatide across BMI range groups (p < 0.0001), while weight increased with both comparators. Achievement of HbA1c <7.0% (<53 mmol/mol) without weight gain was greater for exenatide versus comparators. Systolic blood pressure decreased across BMI range groups with exenatide in the lispro-comparator study (p < 0.0001); changes in lipids were not clinically meaningful. Minor hypoglycaemia was less frequent for exenatide versus insulin lispro. These findings suggest that BMI alone should not limit clinical decision-making or patient access to medication. PMID:27027802
Goswami, Ipsita; Rochow, Niels; Fusch, Gerhard; Liu, Kai; Marrin, Michael L.; Heckmann, Matthias; Nelle, Mathias; Fusch, Christoph
2016-01-01
Objective: Postnatal tissue accretion in preterm infants differs from those in utero, affecting body composition (BC) and lifelong morbidity. Length normalized BC data allows infants with different body lengths to be compared and followed longitudinally. This study aims to analyze BC of preterm and term infants during the first six months of life. Methods: The BC data, measured using dual energy X-ray absorptiometry, of 389 preterm and 132 term infants from four longitudinal studies were combined. Fat-mass/length2 (FMI) and fat-free mass/length2 (FFMI) for postmenstrual age were calculated after reaching full enteral feeding, at term and two further time points up to six months corrected age. Results: Median FMI (preterm) increased from 0.4 kg/m2 at 30 weeks to 2.5, 4.3, and 4.8 kg/m2 compared to 1.7, 4.7, and 6 kg/m2 in term infants at 40, 52, and 64 weeks, respectively. Median FFMI (preterm) increased from 8.5 kg/m2 (30 weeks) to 11.4 kg/m2 (45 weeks) and remained constant thereafter, whereas term FFMI remained constant at 11 kg/m2 throughout the tested time points. Conclusion: The study provides a large dataset of length normalized BC indices. Followed longitudinally, term and preterm infants differ considerably during early infancy in the pattern of change in FMI and FFMI for age. PMID:27399768
Long-term optical variability of high-mass X-ray binaries. II. Spectroscopy
NASA Astrophysics Data System (ADS)
Reig, P.; Nersesian, A.; Zezas, A.; Gkouvelis, L.; Coe, M. J.
2016-05-01
Context. High-mass X-ray binaries are bright X-ray sources. The high-energy emission is caused by the accretion of matter from the massive companion onto a neutron star. The accreting material comes from either the strong stellar wind in binaries with supergiant companions or the cirscumstellar disk in Be/X-ray binaries. In either case, the Hα line stands out as the main source of information about the state of the accreting material. Aims: We present the results of our monitoring program to study the long-term variability of the Hα line in high-mass X-ray binaries. Our aim is to characterise the optical variability timescales and study the interaction between the neutron star and the accreting material. Methods: We fitted the Hα line with Gaussian profiles and obtained the line parameters and equivalent width. The peak separation in split profiles was used to determine the disk velocity law and estimate the disk radius. The relative intensity of the two peaks (V/R ratio) allowed us to investigate the distribution of gas particles in the disk. The equivalent width was used to characterise the degree of variability of the systems. We also studied the variability of the Hα line in correlation with the X-ray activity. Results: Our results can be summarised as follows: i) we find that Be/X-ray binaries with narrow orbits are more variable than systems with long orbital periods; ii) we show that a Keplerian distribution of gas particles provides a good description of the disks in Be/X-ray binaries, as it does in classical Be stars; iii) a decrease in the Hα equivalent width is generally observed after major X-ray outbursts; iv) we confirm that the Hα equivalent width correlates with disk radius; v) while systems with supergiant companions display multi-structured profiles, most of the Be/X-ray binaries show, at some epoch, double-peak asymmetric profiles, which indicates that density inhomogeneities is a common property in the disk of Be/X-ray binaries; vi) the
Chris Quigg
2007-12-05
In the classical physics we inherited from Isaac Newton, mass does not arise, it simply is. The mass of a classical object is the sum of the masses of its parts. Albert Einstein showed that the mass of a body is a measure of its energy content, inviting us to consider the origins of mass. The protons we accelerate at Fermilab are prime examples of Einsteinian matter: nearly all of their mass arises from stored energy. Missing mass led to the discovery of the noble gases, and a new form of missing mass leads us to the notion of dark matter. Starting with a brief guided tour of the meanings of mass, the colloquium will explore the multiple origins of mass. We will see how far we have come toward understanding mass, and survey the issues that guide our research today.
Systematics of Coupling Flows in AdS Backgrounds
Goldberger, Walter D.; Rothstein, Ira Z.
2003-03-18
We give an effective field theory derivation, based on the running of Planck brane gauge correlators, of the large logarithms that arise in the predictions for low energy gauge couplings in compactified AdS}_5 backgrounds, including the one-loop effects of bulk scalars, fermions, and gauge bosons. In contrast to the case of charged scalars coupled to Abelian gauge fields that has been considered previously in the literature, the one-loop corrections are not dominated by a single 4D Kaluza-Klein mode. Nevertheless, in the case of gauge field loops, the amplitudes can be reorganized into a leading logarithmic contribution that is identical to the running in 4D non-Abelian gauge theory, and a term which is not logarithmically enhanced and is analogous to a two-loop effect in 4D. In a warped GUT model broken by the Higgs mechanism in the bulk,we show that the matching scale that appears in the large logarithms induced by the non-Abelian gauge fields is m_{XY}^2/k where m_{XY} is the bulk mass of the XY bosons and k is the AdS curvature. This is in contrast to the UV scale in the logarithmic contributions of scalars, which is simply the bulk mass m. Our results are summarized in a set of simple rules that can be applied to compute the leading logarithmic predictions for coupling constant relations within a given warped GUT model. We present results for both bulk Higgs and boundary breaking of the GUT gauge
Pereira, A B D; Utsumi, S A; Dorich, C D; Brito, A F
2015-12-01
The objective of this study was to use spot short-term measurements of CH4 (QCH4) and CO2 (QCO2) integrated with backward dietary energy partition calculations to estimate dry matter intake (DMI) in lactating dairy cows. Twelve multiparous cows averaging 173±37d in milk and 4 primiparous cows averaging 179±27d in milk were blocked by days in milk, parity, and DMI (as a percentage of body weight) and, within each block, randomly assigned to 1 of 2 treatments: ad libitum intake (AL) or restricted intake (RI=90% DMI) according to a crossover design. Each experimental period lasted 22d with 14d for treatments adaptation and 8d for data and sample collection. Diets contained (dry matter basis): 40% corn silage, 12% grass-legume haylage, and 48% concentrate. Spot short-term gas measurements were taken in 5-min sampling periods from 15 cows (1 cow refused sampling) using a portable, automated, open-circuit gas quantification system (GreenFeed, C-Lock Inc., Rapid City, SD) with intervals of 12h between the 2daily samples. Sampling points were advanced 2h from a day to the next to yield 16 gas samples per cow over 8d to account for diurnal variation in QCH4 and QCO2. The following equations were used sequentially to estimate DMI: (1) heat production (MJ/d)=(4.96 + 16.07 ÷ respiratory quotient) × QCO2; respiratory quotient=0.95; (2) metabolizable energy intake (MJ/d)=(heat production + milk energy) ± tissue energy balance; (3) digestible energy (DE) intake (MJ/d)=metabolizable energy + CH4 energy + urinary energy; (4) gross energy (GE) intake (MJ/d)=DE + [(DE ÷ in vitro true dry matter digestibility) - DE]; and (5) DMI (kg/d)=GE intake estimated ÷ diet GE concentration. Data were analyzed using the MIXED procedure of SAS (SAS Institute Inc., Cary, NC) and Fit Model procedure in JMP (α=0.05; SAS Institute Inc.). Cows significantly differed in DMI measured (23.8 vs. 22.4kg/d for AL and RI, respectively). Dry matter intake estimated using QCH4 and QCO2 coupled with
A new instrument for short-term monitoring of ambient aerosol fine mass concentration has been developed based on a unique device called a Tapered Element Oscillating Microbalance (TEOM). The detector consists of a tapered hollow tube fixed at the wide end and holding an exchange...
The Influence of Body Mass Index on Long-Term Fitness from Physical Education in Adolescent Girls
ERIC Educational Resources Information Center
Camhi, Sarah M.; Phillips, Jennie; Young, Deborah R.
2011-01-01
Background: Physical education (PE) can improve physical fitness; however, little research has evaluated PE's long-term influence. The purpose is to determine PE's longitudinal effects on fitness in a group of adolescent girls and to determine whether body mass index (BMI) status influenced any potential effects. Methods: Participants were…
ERIC Educational Resources Information Center
Orsini, Larry L.; Hudack, Lawrence R.; Zekan, Donald L.
1999-01-01
The value-added statement (VAS), relatively unknown in the United States, is used in financial reports by many European companies. Saint Bonaventure University (New York) has adapted a VAS to make it appropriate for not-for-profit universities by identifying stakeholder groups (students, faculty, administrators/support personnel, creditors, the…
Malfatti, Michael A.; Palko, Heather A.; Kuhn, Edward A.; Turteltaub, Kenneth W.
2012-01-01
Biodistribution is an important factor in better understanding silica dioxide nanoparticle (SiNP) safety. Currently, comprehensive studies on biodistribution are lacking, most likely due to the lack of suitable analytical methods. Accelerator mass spectrometry (AMS) was used to investigate the relationship between administered dose, PK, and long-term biodistribution of 14C-SiNPs in vivo. PK analysis showed that SiNPs were rapidly cleared from the central compartment, were distributed to tissues of the reticuloendothelial system, and persisted in the tissue over the 8-week time course, raising questions about the potential for bioaccumulation and associated long-term effects. PMID:23075393
Bohr Hamiltonian with a deformation-dependent mass term for the Davidson potential
Bonatsos, Dennis; Georgoudis, P. E.; Lenis, D.; Minkov, N.; Quesne, C.
2011-04-15
Analytical expressions for spectra and wave functions are derived for a Bohr Hamiltonian, describing the collective motion of deformed nuclei, in which the mass is allowed to depend on the nuclear deformation. Solutions are obtained for separable potentials consisting of a Davidson potential in the {beta} variable, in the cases of {gamma}-unstable nuclei, axially symmetric prolate deformed nuclei, and triaxial nuclei, implementing the usual approximations in each case. The solution, called the deformation-dependent mass (DDM) Davidson model, is achieved by using techniques of supersymmetric quantum mechanics (SUSYQM), involving a deformed shape invariance condition. Spectra and B(E2) transition rates are compared to experimental data. The dependence of the mass on the deformation, dictated by SUSYQM for the potential used, reduces the rate of increase of the moment of inertia with deformation, removing a main drawback of the model.
NASA Astrophysics Data System (ADS)
Carjan, N.; Ivanyuk, F. A.; Oganessian, Yu.; Ter-Akopian, G.
2015-10-01
The total deformation energy at scission for Z = 100, 102, 104 and 106 isotopes is calculated using the Strutinsky's procedure and nuclear shapes described in terms of Cassinian ovals generalized by the inclusion of three additional shape parameters: α1, α4 and α6. The corresponding fragment-mass distributions are estimated supposing they are due to thermal fluctuations in the mass asymmetry degree of freedom. For these four series of isotopes the experimentally observed transition from asymmetric to symmetric fission, that happens with increasing mass number A, is qualitatively reproduced. In lighter isotopes (e.g. 254Fm and 254Rf) two mass-asymmetric fission modes are predicted to occur with comparable yields: one having relatively compact and the other relatively elongated scission configurations. On the other hand, in heavier isotopes (e.g. 264Fm and 264Rf) the fragment-mass distributions are predicted to be narrow single-peaked around A / 2 corresponding to essentially one mass-symmetric fission mode. The mass distributions are estimated separately for each fission mode, in the case of Fm and Rf isotopes, in order to display their inversion when A increases. Finally the distributions of the total kinetic energy of the fragments are calculated, for the same isotopes, in the point-charge approximation. Non-Gaussian shapes are obtained. With increasing mass number A, a transition from a distribution tailing towards higher energies to a distribution tailing towards lower energies and an increase of the difference in the peak positions of the two modes were observed; again in qualitative agreement with experimental data.
Coming to Terms with Mass Higher Education: Lessons from the United States and beyond
ERIC Educational Resources Information Center
Bassett, Roberta Malee; Tapper, Ted
2009-01-01
Mass higher education, a characteristic recently unique to the United States of America, is now almost universal in scope in developed countries. This article contrasts the relative ease with which American higher education accommodated the rapid expansion of its student base with the difficulties that the United Kingdom, more particularly…
Supersymmetric warped AdS in extended topologically massive supergravity
NASA Astrophysics Data System (ADS)
Deger, N. S.; Kaya, A.; Samtleben, H.; Sezgin, E.
2014-07-01
We determine the most general form of off-shell N=(1,1) supergravity field configurations in three dimensions by requiring that at least one off-shell Killing spinor exists. We then impose the field equations of the topologically massive off-shell supergravity and find a class of solutions whose properties crucially depend on the norm of the auxiliary vector field. These are spacelike-squashed and timelike-stretched AdS3 for the spacelike and timelike norms, respectively. At the transition point where the norm vanishes, the solution is null warped AdS3. This occurs when the coefficient of the Lorentz-Chern-Simons term is related to the AdS radius by μℓ=2. We find that the spacelike-squashed AdS3 can be modded out by a suitable discrete subgroup of the isometry group, yielding an extremal black hole solution which avoids closed timelike curves.
Internal structure of charged AdS black holes
NASA Astrophysics Data System (ADS)
Bhattacharjee, Srijit; Sarkar, Sudipta; Virmani, Amitabh
2016-06-01
When an electrically charged black hole is perturbed, its inner horizon becomes a singularity, often referred to as the Poisson-Israel mass inflation singularity. Ori constructed a model of this phenomenon for asymptotically flat black holes, in which the metric can be determined explicitly in the mass inflation region. In this paper we implement the Ori model for charged AdS black holes. We find that the mass function inflates faster than the flat space case as the inner horizon is approached. Nevertheless, the mass inflation singularity is still a weak singularity: Although spacetime curvature becomes infinite, tidal distortions remain finite on physical objects attempting to cross it.
Long-term evolution of an ecosystem with spontaneous periodicity of mass extinctions.
Lipowski, Adam; Lipowska, Dorota
2006-08-01
Twenty years ago, after analysing palaeontological data, Raup and Sepkoski suggested that mass extinctions on Earth appear cyclically in time with a period of approximately 26 million years (My). To explain the 26My period, a number of proposals were made involving, e.g., astronomical effects, increased volcanic activity, or the Earth's magnetic field reversal, none of which, however, has been confirmed. Here we study a spatially extended discrete model of an ecosystem and show that the periodicity of mass extinctions might be a natural feature of the ecosystem's dynamics and not the result of a periodic external perturbation. In our model, periodic changes of the diversity of an ecosystem and some of its other characteristics are induced by the coevolution of species. In agreement with some palaeontological data, our results show that the longevity of a species depends on the evolutionary stage at which the species is created. Possible further tests of our model are also discussed. PMID:17046374
Bohr Hamiltonian with a deformation-dependent mass term: physical meaning of the free parameter
NASA Astrophysics Data System (ADS)
Bonatsos, Dennis; Minkov, N.; Petrellis, D.
2015-09-01
Embedding the five-dimensional (5D) space of the Bohr Hamiltonian with a deformation-dependent mass (DDM) into a six-dimensional (6D) space shows that the free parameter in the dependence of the mass on the deformation is connected to the curvature of the 5D space, with the special case of constant mass corresponding to a flat 5D space. Comparison of the DDM Bohr Hamiltonian to the 5D classical limit of Hamiltonians of the 6D interacting boson model (IBM), shows that the DDM parameter is proportional to the strength of the pairing interaction in the U(5) (vibrational) symmetry limit, while it is proportional to the quadrupole-quadrupole interaction in the SU(3) (rotational) symmetry limit, and to the difference of the pairing interactions among s, d bosons and d bosons alone in the O(6) (γ-soft) limit. The presence of these interactions leads to a curved 5D space in the classical limit of IBM, in contrast to the flat 5D space of the original Bohr Hamiltonian, which is made curved by the introduction of the DDM.
Long-term mass transfer and mixing-controlled reactions of a DNAPL plume from persistent residuals
NASA Astrophysics Data System (ADS)
Liu, Yuan; Illangasekare, Tissa H.; Kitanidis, Peter K.
2014-02-01
Understanding and being able to predict the long-term behavior of DNAPL (i.e., PCE and TCE) residuals after active remediation has ceased have become increasingly important as attention at many sites turns from aggressive remediation to monitored natural attenuation and long-term stewardship. However, plume behavior due to mass loading and reactions during these later phases is less studied as they involve large spatial and temporal scales. We apply both theoretical analysis and pore-scale simulations to investigate mass transfer from DNAPL residuals and subsequent reactions within the generated plume, and, in particular, to show the differences between early- and late-time behaviors of the plume. In the zone of entry of the DNAPL entrapment zone where the concentration boundary layer in the flowing groundwater has not fully developed, the pore-scale simulations confirm the past findings based on laboratory studies that the mass transfer increases as a power-law function of the Peclét number, and is enhanced due to reactions in the plume. Away from the entry zone and further down gradient, the long-term reactions are limited by the available additive and mixing in the porous medium, thereby behave considerably differently from the entry zone. For the reaction between the contaminant and an additive with intrinsic second-order bimolecular kinetics, the late-time reaction demonstrates a first-order decay macroscopically with respect to the mass of the limiting additive, not with respect to that of the contaminant. The late-time decay rate only depends on the intrinsic reaction rate and the solubility of the entrapped DNAPL. At the intermediate time, the additive decays exponentially with the square of time (t2), instead of time (t). Moreover, the intermediate decay rate also depends on the initial conditions, the spatial distribution of DNAPL residuals, and the effective dispersion coefficient.
NASA Astrophysics Data System (ADS)
Martelli, Dario; Morales, Jose F.
2005-02-01
In the light of the recent Lin, Lunin, Maldacena (LLM) results, we investigate 1/2-BPS geometries in minimal (and next to minimal) supergravity in D = 6 dimensions. In the case of minimal supergravity, solutions are given by fibrations of a two-torus T2 specified by two harmonic functions. For a rectangular torus the two functions are related by a non-linear equation with rare solutions: AdS3 × S3, the pp-wave and the multi-center string. ``Bubbling'', i.e. superpositions of droplets, is accommodated by allowing the complex structure of the T2 to vary over the base. The analysis is repeated in the presence of a tensor multiplet and similar conclusions are reached, with generic solutions describing D1D5 (or their dual fundamental string-momentum) systems. In this framework, the profile of the dual fundamental string-momentum system is identified with the boundaries of the droplets in a two-dimensional plane.
Hu, Yu; Lai, Jinsheng; Wan, Baoquan; Liu, Xingfa; Zhang, Yemao; Zhang, Jiangong; Sun, Dongsheng; Ruan, Guoran; Liu, Enjie; Liu, Gong-Ping; Chen, Chen; Wang, Dao Wen
2016-03-01
Although numerous studies have reported the influence of extremely low frequency magnetic field (ELF-MF) exposure on human health, its effects on cognitive deficits in Alzheimer's disease (AD) have remained under debate. Moreover, the influence of ELF-MF on hyperphosphorylated tau, which is one of the most common pathological hallmarks of AD, has not been reported to date. Therefore, transgenic mice (3xTg) were used in the present study. 3xTg mice, which express an APP/PS1 mutation combined with a tau (P301L) mutation and that develop cognitive deficits at 6 months of age, were subjected to ELF-MF (50Hz, 500μT) exposure or sham exposure daily for 3 months. We discovered that ELF-MF exposure ameliorated cognitive deficits and increased synaptic proteins in 3xTg mice. The protective effects of ELF-MF exposure may have also been caused by the inhibition of apoptosis and/or decreased oxidative stress levels that were observed in the hippocampus tissues of treated mice. Furthermore, tau hyperphosphorylation was decreased in vivo because of ELF-MF exposure, and this decrease was induced by the inhibition of GSK3β and CDK5 activities and activation of PP2Ac. We are the first to report that exposure to ELF-MF can attenuate tau phosphorylation. These findings suggest that ELF-MF exposure could act as a valid therapeutic strategy for ameliorating cognitive deficits and attenuating tau hyperphosphorylation in AD. PMID:26945731
Gagné, Lynda
2008-03-01
The effect of the 2005 British Columbia (BC) smoking cessation mass media campaign on a panel (N = 1,341) of 20-30-year-old smokers' attitudes is evaluated. The 5-week campaign consisted of posters, television, and radio ads about the health benefits of cessation. Small impacts on the panel's attitudes toward the adverse impacts of smoking were found, with greater impacts found for those who had no plans to quit smoking at the initial interview. As smokers with no plans to quit increasingly recognized the adverse impacts of smoking, they also increasingly agreed that they use smoking as a coping mechanism. Smokers with plans to quit at the initial interview already were well aware of smoking's adverse impacts. Respondents recalling the campaign poster, which presented a healthy alternative to smoking, decreased their perception of smoking as a coping mechanism and devalued their attachment to smoking. Evidence was found that media ad recall mediates unobserved predictors of attitudes toward smoking. PMID:18300065
Local monitoring of post-treatment drinking water using bench-top mass spectrometers could identify target compounds in a mass spectral library. However, a terrorist might seek to incite greater hysteria by injecting or infusing a mixture of unanticipated compounds of unknown tox...
Supergravity at the boundary of AdS supergravity
NASA Astrophysics Data System (ADS)
Amsel, Aaron J.; Compère, Geoffrey
2009-04-01
We give a general analysis of AdS boundary conditions for spin-3/2 Rarita-Schwinger fields and investigate boundary conditions preserving supersymmetry for a graviton multiplet in AdS4. Linear Rarita-Schwinger fields in AdSd are shown to admit mixed Dirichlet-Neumann boundary conditions when their mass is in the range 0≤|m|<1/2lAdS. We also demonstrate that mixed boundary conditions are allowed for larger masses when the inner product is “renormalized” accordingly with the action. We then use the results obtained for |m|=1/lAdS to explore supersymmetric boundary conditions for N=1 AdS4 supergravity in which the metric and Rarita-Schwinger fields are fluctuating at the boundary. We classify boundary conditions that preserve boundary supersymmetry or superconformal symmetry. Under the AdS/CFT dictionary, Neumann boundary conditions in d=4 supergravity correspond to gauging the superconformal group of the three-dimensional CFT describing M2-branes, while N=1 supersymmetric mixed boundary conditions couple the CFT to N=1 superconformal topologically massive gravity.
NASA Astrophysics Data System (ADS)
Lorenzini, Sandra; Baroni, Carlo; Fallick, Anthony Edward; Baneschi, Ilaria; Salvatore, Maria Cristina; Zanchetta, Giovanni; Dallai, Luigi
2010-05-01
The stable isotopes geochemistry of carbon and nitrogen provides a powerful tools for investigating in animal dietary patterns and shifts during the past. The signature of C and N isotopes provide direct information about the diet of an individual and its dietary patterns, especially when the dietary sources consist of prey from different trophic levels (i.e. different C and N isotopic composition) (DeNiro and Epstein 1978, Minawaga and Wada 1984, Koch et al. 1994, Hobson 1995). By analyzing the isotopic composition of penguin remains, we present a new detailed Adélie penguin (Pygoscelis adeliae) paleodietary record for the area of Terra Nova Bay (Victoria Land, Ross Sea). Adélie penguins primarily feed on fish (mainly the silverfish Pleuragramma antarcticum) and krill (Euphausia superba, Euphausia cristallorophias) (Ainley 2002, Lorenzini et al. 2009) that belonging to two different trophic levels. Consequently, they are characterized by different isotopic signatures. Specifically, we analyzed 13C/12C and 15N/14N ratios of more than one thousand of modern and fossil Adélie penguin eggshell and guano samples collected from ornithogenic soils (penguin guano-formed) dated back to ≈7,200 years BP (Baroni and Orombelli 1994, Lambert et al. 2002, Baroni and Hall 2004, Hall et al. 2006). The expanded database of stable isotope values obtained from Adélie penguin remains define a detailed paleodietary record with an excellent temporal continuity over all the investigated time period. Our data indicate a significant dietary shift between fish and krill, with a gradual decrease from past to present time in the proportion of fish compared to krill in Adélie penguin diet. From 7200 yrs BP to 2000 yrs BP, δ13C and δ15N values indicate fish as the most eaten prey. The dietary contribution of lower-trophic prey in penguin diet started becoming evident not earlier than 2000 yrs BP, when the δ13C values reveal a mixed diet based on fish and krill consumption. Modern
[Metabolic changes in climacteric women in terms of body mass index].
Murillo-Uribe, A; Carranza-Lira, S; Ascencio-González, D; Santos-González, J
1996-04-01
The objective was to identify climateric woman with cardiovasculary risk by the relation between size and weight, known as corporal mass index. Seven hundred and ninety seven postmenopausal patients, were studied; they attended the CECLIMEN, with one or two years of spontaneous menopause, and they were not receiving, nor had received replacement hormonal therapy (RHT). In all of them clinical history was taken, and blood pressure, weight, size and corporal mass index (CMI) (weight/(size)2), were evaluated; considering normal weight when CMI was < or = 27, and obesity when this index was greater than 27. Fastening and postprandial glucose at two hours, was determined, as well as total cholesterol, HDL-C, cholesterol of low density lipoproteins (LDL-C), triglicéridos (Tg), and aterogenic index was calculated by CtHDL-C. Besides, estradiol (E2) and follicle stimulating hormone (FSH) were measured in serum by radioimmunoanalysis RIA. Results were considered in the two groups, according to CMI: Group I with CMI < or = 27 (n = 566); and group II, with CMI > 27 (n = 231). Blood pressure, systolic and diastolic, triglicerides and aterogenic index were significantly greater in group II. There were higher levels of glucose in group II (tendency). CMI > 27 is useful to differentiate the postmenopausal women with a higher cardiovasculary risk. PMID:8698245
Long-term mass changes over Greenland derived from high-low satellite-to-satellite tracking
NASA Astrophysics Data System (ADS)
Weigelt, Matthias; van Dam, Tonie; Jäggi, Adrian; Prange, Lars; Sneeuw, Nico; Keller, Wolfgang
2013-04-01
In the last decade, temporal variations of the global gravity field have become an ubiquitous and invaluable source of information for geophysical and environmental studies. It is important that the time series of observations is not interrupted as some geophysical phenomena, e.g. postglacial rebound or long term ice mass trends, are only beginning to be observable. To date, the most valuable source for time variable gravity (TVG) is the GRACE mission which has already exceeded its nominal lifetime. It can cease operations any time now and then only high-low satellite-to-satellite (hl-SST) observations will be available. These observations have, however, only demonstrated limited application for TVG. In this presentation, we show that by using CHAMP data, a thorough reprocessing strategy and a dedicated Kalman filter it is possible to derive the very long wavelength features of the time variable gravity field. The results are validated against GRACE data and height coordinates from long-term GPS ground stations in Greenland. We find that the quality of the CHAMP solutions is sufficient to derive realistic long-term trends and annual amplitudes of mass changes of Greenland. We conclude that hl-SST would be a viable substitute (although at lower spatial resolution) for TVG in the event of a profund operational breakdown of GRACE.
NASA Astrophysics Data System (ADS)
Reed, Patrick; Minsker, Barbara; Valocchi, Albert J.
2000-12-01
A new methodology for sampling plan design has been developed to reduce the costs associated with long-term monitoring of sites with groundwater contamination. The method combines a fate-and-transport model, plume interpolation, and a genetic algorithm to identify cost-effective sampling plans that accurately quantify the total mass of dissolved contaminant. The plume interpolation methods considered were inverse-distance weighting, ordinary kriging, and a hybrid method that combines the two approaches. Application of the methodology to Hill Air Force Base indicated that sampling costs could be reduced by as much as 60% without significant loss in accuracy of the global mass estimates. Inverse-distance weighting was shown to be most effective as a screening tool for evaluating whether more comprehensive geostatistical modeling is warranted. The hybrid method was effective for implementing such a tiered approach, reducing computational time by more than 60% relative to kriging alone.
NASA Astrophysics Data System (ADS)
Kulshreshtha, Usha; Kulshreshtha, Daya Shankar; Vary, James P.
2016-01-01
Recently (in a series of papers) we have studied the vector Schwinger model with a photon mass term describing one-space one-time dimensional electrodynamics with mass-less fermions in the so-called standard regularization. In the present work, we study this model in the Faddeevian regularization (FR). This theory in the FR is seen to be gauge-non-invariant (GNI). We study the Hamiltonian and path integral quantization of this GNI theory. We then construct a gauge-invariant (GI) theory corresponding to this GNI theory using the Stueckelberg mechanism and recover the physical content of the original GNI theory from the newly constructed GI theory under some special gauge-choice. Further, we study the Hamiltonian, path integral and Becchi-Rouet-Stora and Tyutin formulations of the newly constructed GI theory under appropriate gauge-fixing conditions.
Seretis, Konstantinos; Goulis, Dimitrios G; Koliakos, Georgios; Demiri, Efterpi
2015-10-01
Adipose tissue is considered as an endocrine organ, which is developed in specific depots, distinguished either as subcutaneous or visceral. Lipectomy, by means of liposuction or abdominoplasty, is a common plastic surgery procedure, which can remove substantial amounts of subcutaneous fat. This systematic review aims to evaluate the impact of surgical removal of abdominal subcutaneous adipose tissue on body weight and fat mass in females in the short- and long-term. A systematic review was conducted using a predetermined protocol established according to the Cochrane Handbook's recommendations. PubMed, Scopus, CENTRAL, and the Cochrane Library were searched from inception to December 2014. Eligible studies were prospective studies with ≥1 month of follow-up that included female only individuals who underwent lipectomy of the abdominal region and reported on body weight, body mass index (BMI), or fat mass. Ten studies were included in this systematic review with a total of 231 individuals. A significant weight loss and BMI improvement were reported in 4 out of 5 studies with a mean follow-up of 1-2 months, but in none of the 5 studies with a longer follow-up (3-20 months). Fat mass showed a similar to weight change. The risk of bias was low for the two clinical trials but high for the observational studies included in the review. This systematic review revealed only a transient effect of abdominal lipectomy in body fat and weight in women, which fades a few months after the operation. These results corroborate the evidence from experimental and clinical studies, which support fat redistribution and compensatory fat growth, as a result of feedback mechanisms, triggered by fat removal. Additional clinical studies, with adequate follow-up, may further elucidate the long-term effects of abdominal lipectomy in body weight and composition. Systematic review registration PROSPERO CRD42015017564 ( www.crd.york.ac.uk/PROSPERO ). PMID:26210190
On the need to manage long-term diffuse memory controls of hydrological mass loads and water quality
NASA Astrophysics Data System (ADS)
Destouni, G.; Cvetkovic, V.
2011-12-01
Water management requires understanding and handling of water quality changes and their cause-effect relations, including the source inputs in and hydrological mass transport through catchments that load tracers, nutrients, pollutants and other anthropogenic and geogenic constituents to downstream waters and ecosystems. Costly abatement is often required to protect water resources and ecosystems from excessive nutrient and pollutant loads, and to maintain and restore good ecological status and vital ecosystem services of water systems. But what controls then the magnitudes and dynamics of the hydrological mass loads to the downstream waters and ecosystems? Erroneous understanding of these controls may undermine and mislead resource demanding water management efforts. To support and improve this understanding we have analyzed data from 15-23 year time series of chloride, commonly used as an effective chemical tracer of water movement, in daily rainfall and runoff of two comparative Swedish catchments. We show that long-term catchment memory in form of diffuse internal subsurface sources that have developed from earlier mass inputs controls current load dynamics. In the chloride tracer example the internal memory sources contribute 75-90% of the total stream load, while contemporary source inputs at the surface contribute only 10-25%, with these ranges being consistently determined from scenario analysis of chloride travel time distributions in both catchment cases. While the loading from contemporary surface inputs is hydrologically controlled and dependent on the variability of transport pathways and travel times through a catchment, the average net mass release rate from internal memory sources depends primarily on mean travel time. For the chloride tracer example the release rate is in the range of 1.3*10E-4 - 4.5*10E-3 g/m2/day in both catchment cases. The present quantification approach provides a relatively simple, testable and general management tool for
NASA Astrophysics Data System (ADS)
Pitts, J. Brian
2016-02-01
Einstein's equations were derived for a free massless spin-2 field using universal coupling in the 1950-1970s by various authors; total stress-energy including gravity's served as a source for linear free field equations. A massive variant was likewise derived in the late 1960s by Freund, Maheshwari and Schonberg, and thought to be unique. How broad is universal coupling? In the last decade four 1-parameter families of massive spin-2 theories (contravariant, covariant, tetrad, and cotetrad of almost any density weights) have been derived using universal coupling. The (co)tetrad derivations included 2 of the 3 pure spin-2 theories due to de Rham, Gabadadze, and Tolley; those two theories first appeared in the 2-parameter Ogievetsky-Polubarinov family (1965), which developed the symmetric square root of the metric as a nonlinear group realization. One of the two theories was identified as pure spin-2 by Maheshwari in 1971-1972, thus evading the Boulware-Deser-Tyutin-Fradkin ghost by the time it was announced. Unlike the previous 4 families, this paper permits nonlinear field redefinitions to build the effective metric. By not insisting in advance on knowing the observable significance of the graviton potential to all orders, one finds that an arbitrary graviton mass term can be derived using universal coupling. The arbitrariness of a universally coupled mass/self-interaction term contrasts sharply with the uniqueness of the Einstein kinetic term. One might have hoped to use universal coupling as a tie-breaking criterion for choosing among theories that are equally satisfactory on more crucial grounds (such as lacking ghosts and having a smooth massless limit). But the ubiquity of universal coupling implies that the criterion does not favor any particular theories among those with the Einstein kinetic term.
Do erosion rates control the long-term carbon isotope mass balance?
NASA Astrophysics Data System (ADS)
Shields-Zhou, G. A.
2014-12-01
The long-term marine carbon isotope record responds to changes in the proportional burial rates of organic carbon relative to carbonate carbon on a global scale. For this reason, high δ13C values in marine carbonate rocks are normally interpreted to reflect faster rates of organic burial and increased atmospheric oxygenation. Geochemical redox tracers fail to support this paradigm for sustained deviations from the long-term δ13C mean, indicating perhaps that proportionally high organic burial may be associated with lower overall flux rates. Here I propose that ~107-108 year trends in average δ13C, as with seawater 87Sr/86Sr, are driven by changes in the balance between volcanism and denudation (~uplift). In other words, high proportional organic burial may be related to increases in the net CO2 flux (= organic carbon burial + Ca-Mg silicate weathering) relative to the carbonate weathering flux. According to this model, high baseline δ13C values will be associated with periods of heightened volcanic activity and/or diminished tectonic uplift. Conversely, lower baseline δ13C values can be related to times when the global carbon cycle was dominated by carbonate and oxidative weathering due to high rates of physical erosion. Shorter 105-106 year positive δ13C excursions have also been interpreted as the 'smoking gun' to extreme oxygenation events. However, large increases in organic burial are difficult to sustain under steady-state conditions without very high volcanic fluxes, indicating that some of these excursions might be better explained by transient changes to the isotopic composition of carbon sources and sinks.
All AdS7 solutions of type II supergravity
NASA Astrophysics Data System (ADS)
Apruzzi, Fabio; Fazzi, Marco; Rosa, Dario; Tomasiello, Alessandro
2014-04-01
In M-theory, the only AdS7 supersymmetric solutions are AdS7 × S 4 and its orbifolds. In this paper, we find and classify new supersymmetric solutions of the type AdS7 × M 3 in type II supergravity. While in IIB none exist, in IIA with Romans mass (which does not lift to M-theory) there are many new ones. We use a pure spinor approach reminiscent of generalized complex geometry. Without the need for any Ansatz, the system determines uniquely the form of the metric and fluxes, up to solving a system of ODEs. Namely, the metric on M 3 is that of an S 2 fibered over an interval; this is consistent with the Sp(1) R-symmetry of the holographically dual (1,0) theory. By including D8 brane sources, one can numerically obtain regular solutions, where topologically M 3 ≅ S 3.
Schänzer, Wilhelm; Geyer, Hans; Fusshöller, Gregor; Halatcheva, Natalia; Kohler, Maxie; Parr, Maria-Kristina; Guddat, Sven; Thomas, Andreas; Thevis, Mario
2006-01-01
Anabolic-androgenic steroids are some of the most frequently detected drugs in amateur and professional sports. Doping control laboratories have developed numerous assays enabling the determination of administered drugs and/or their metabolic products that allow retrospectives with respect to pharmacokinetics and excretion profiles of steroids and their metabolites. A new metabolite generated from metandienone has been identified as 18-nor-17beta-hydroxymethyl,17alpha-methyl-androst-1,4,13-trien-3-one in excretion study urine samples providing a valuable tool for the long-term detection of metandienone abuse by athletes in sports drug testing. The metabolite was characterized using gas chromatography/(tandem) mass spectrometry, liquid chromatography/tandem mass spectrometry and liquid chromatography/high-resolution/high-accuracy (tandem) mass spectrometry by characteristic fragmentation patterns representing the intact 3-keto-1,4-diene structure in combination with typical product ions substantiating the proposed C/D-ring structure of the steroid metabolite. In addition, structure confirmation was obtained by the analysis of excretion study urine specimens obtained after administration of 17-CD(3)-labeled metandienone providing the deuterated analogue to the newly identified metabolite. 18-Nor-17beta-hydroxymethyl,17alpha-methyl-androst-1,4,13-trien-3-one was determined in metandienone administration study urine specimens up to 19 days after application of a single dose of 5 mg, hence providing an extended detection period compared with commonly employed strategies. PMID:16804957
NASA Astrophysics Data System (ADS)
Karwan, D. L.; Pizzuto, J. E.; Aalto, R. E.; Marquard, J.; Aufdenkampe, A. K.; Benthem, A.; Skalak, K.; Levia, D. F., Jr.; Siegert, C. M.
2015-12-01
Fallout radionuclide ratios, such as the ratio of Beryllium-7 to Lead-210 (7Be/210Pb), are used to determine the age of suspended sediment or fraction of "new" sediment in suspension. In the application of these models new suspended sediment is often assumed to originate from recent landscape surface erosion that is delivered to the stream network. Fallout radionuclide deposition can vary across watersheds and on an event basis in a single watershed due to factors such as storm type, atmospheric height, and storm origin. In the White Clay Creek watershed within the mid-Atlantic USA, single-event deposition of 7Be varies from 15 - 177 Bq m-2 and 210Pb varies from 0 - 10 Bq m-2. 7Be/210Pb ratios vary from 7.9 to 20 in event precipitation and from 0.8 to 12.8 on suspended sediment. "New" sediment varies from 4 - 71% over the course of these events. A computation of the 7Be mass balance during events shows that the majority of 7Be is retained within the catchment. During summer thunderstorms, less than 1% of 7Be deposited on the watershed exits in the stream channel during that event. Therefore, the entirety of the 7Be exiting the watershed on suspended sediment is less than the total activity deposited on the channel in direct precipitation. We attribute this to the new tagging of subaerial fluvial deposits with event precipitation; hence "new" suspended sediment originates from within the channel rather than from surface erosion. During extreme events, such as Hurricane Irene, less of the suspended sediment has been newly tagged by precipitation (4 - 28%) and a larger proportion (3-4%) of the 7Be deposited on the watershed exits during the event. Ongoing work in the Difficult Run watershed in northern Virginia will test the regional applicability of these findings. Water quality efforts to determine the source of sediment using fallout radionuclides must consider the stream channel as well as landscape sources of "new" sediments, particularly during summer
NASA Astrophysics Data System (ADS)
Keune, Katrien; Hoogland, Frank; Boon, Jaap J.; Peggie, David; Higgitt, Catherine
2009-07-01
Naples yellow-containing oil paints aged under natural and artificial conditions were investigated as model systems to evaluate the potential of secondary ion mass spectrometry (SIMS) when used in combination with other mass spectrometric and spectroscopic analytical methods. Although the advantage of SIMS is the simultaneous detection of organic and inorganic components and their spatial distribution, the methodology has limitations in compound sensitivity and shows bias towards certain constituents. Gas chromatography-mass spectrometry (GC/MS) shows dicarboxylic fatty acids to be main components in the paint, but SIMS detects these compounds poorly. Electrospray ionisation mass spectrometry (ESI-MS) shows a broad range of glyceryl derivatives of mono- and dicarboxylic fatty acids (mono-, di- and triglyceride derivatives), while SIMS only detects the mono- and diglycerides of the monocarboxylic acids. Compared to SIMS, direct temperature-resolved mass spectrometry (DTMS) offers greater insight into how the various constituents are incorporated into the paint film, but SIMS data supports the information provided by Fourier transform infrared (FTIR) on metal soap formation. The surface sensitivity of SIMS is an advantage for probing paint constituent distributions and was exploited to examine variations in the composition of the top and bottom of a paint film, and the spatial correlation between metal and fatty acid composition in metal soap aggregates. Disadvantages of SIMS are the low yields and matrix dependency of the organic species in the paint matrix. Application of an ultra-thin gold coating overcomes this, and enhances the organic secondary ion yields leading to more accurate spatial distribution.
New massive gravity and AdS(4) counterterms.
Jatkar, Dileep P; Sinha, Aninda
2011-04-29
We show that the recently proposed Dirac-Born-Infeld extension of new massive gravity emerges naturally as a counterterm in four-dimensional anti-de Sitter space (AdS(4)). The resulting on-shell Euclidean action is independent of the cutoff at zero temperature. We also find that the same choice of counterterm gives the usual area law for the AdS(4) Schwarzschild black hole entropy in a cutoff-independent manner. The parameter values of the resulting counterterm action correspond to a c=0 theory in the context of the duality between AdS(3) gravity and two-dimensional conformal field theory. We rewrite this theory in terms of the gauge field that is used to recast 3D gravity as a Chern-Simons theory. PMID:21635026
Collins, Doug; Benedict, Chris; Bary, Andy; Cogger, Craig
2015-01-01
The spatial heterogeneity of soil and weed populations poses a challenge to researchers. Unlike aboveground variability, below-ground variability is more difficult to discern without a strategic soil sampling pattern. While blocking is commonly used to control environmental variation, this strategy is rarely informed by data about current soil conditions. Fifty georeferenced sites were located in a 0.65 ha area prior to establishing a long-term field experiment. Soil organic matter (OM) and weed seed bank populations were analyzed at each site and the spatial structure was modeled with semivariograms and interpolated with kriging to map the surface. These maps were used to formulate three strategic blocking patterns and the efficiency of each pattern was compared to a completely randomized design and a west to east model not informed by soil variability. Compared to OM, weeds were more variable across the landscape and had a shorter range of autocorrelation, and models to increase blocking efficiency resulted in less increase in power. Weeds and OM were not correlated, so no model examined improved power equally for both parameters. Compared to the west to east blocking pattern, the final blocking pattern chosen resulted in a 7-fold increase in power for OM and a 36% increase in power for weeds. PMID:26247056
Collins, Doug; Benedict, Chris; Bary, Andy; Cogger, Craig
2015-01-01
The spatial heterogeneity of soil and weed populations poses a challenge to researchers. Unlike aboveground variability, below-ground variability is more difficult to discern without a strategic soil sampling pattern. While blocking is commonly used to control environmental variation, this strategy is rarely informed by data about current soil conditions. Fifty georeferenced sites were located in a 0.65 ha area prior to establishing a long-term field experiment. Soil organic matter (OM) and weed seed bank populations were analyzed at each site and the spatial structure was modeled with semivariograms and interpolated with kriging to map the surface. These maps were used to formulate three strategic blocking patterns and the efficiency of each pattern was compared to a completely randomized design and a west to east model not informed by soil variability. Compared to OM, weeds were more variable across the landscape and had a shorter range of autocorrelation, and models to increase blocking efficiency resulted in less increase in power. Weeds and OM were not correlated, so no model examined improved power equally for both parameters. Compared to the west to east blocking pattern, the final blocking pattern chosen resulted in a 7-fold increase in power for OM and a 36% increase in power for weeds. PMID:26247056
Hilding, Agneta; Pyko, Andrei; Bluhm, Gösta; Pershagen, Göran; Östenson, Claes-Göran
2014-01-01
Background: Long-term aircraft noise exposure may increase the risk of cardiovascular disease, but no study has investigated chronic effects on the metabolic system. Objectives: The aim of this study was to investigate effects of long-term aircraft noise exposure on body mass index (BMI), waist circumference, and type 2 diabetes. Furthermore, we explored the modifying effects of sleep disturbance. Methods: This prospective cohort study of residents of Stockholm County, Sweden, followed 5,156 participants with normal baseline oral glucose tolerance tests (OGTT) for up to 10 years. Exposure to aircraft noise was estimated based on residential history. Information on outcomes and confounders was obtained from baseline and follow-up surveys and examinations, and participants who developed prediabetes or type 2 diabetes were identified by self-reported physician diagnosis or OGTT at follow-up. Adjusted associations were assessed by linear, logistic, and random-effects models. Results: The mean (± SD) increases in BMI and waist circumference during follow-up were 1.09 ± 1.97 kg/m2 and 4.39 ± 6.39 cm, respectively. The cumulative incidence of prediabetes and type 2 diabetes was 8% and 3%, respectively. Based on an ordinal noise variable, a 5-dB(A) increase in aircraft noise was associated with a greater increase in waist circumference of 1.51 cm (95% CI: 1.13, 1.89), fully adjusted. This association appeared particularly strong among those who did not change their home address during the study period, which may be a result of lower exposure misclassification. However, no clear associations were found for BMI or type 2 diabetes. Furthermore, sleep disturbances did not appear to modify the associations with aircraft noise. Conclusions: Long-term aircraft noise exposure may be linked to metabolic outcomes, in particular increased waist circumference. Citation: Eriksson C, Hilding A, Pyko A, Bluhm G, Pershagen G, Östenson CG. 2014. Long-term aircraft noise exposure and
Chuffa, L G A; Amorim, J P A; Teixeira, G R; Mendes, L O; Fioruci, B A; Pinheiro, P F F; Seiva, F R F; Novelli, E L B; Mello Júnior, W; Martinez, M; Martinez, F E
2011-03-01
Melatonin regulates the reproductive cycle, energy metabolism and may also act as a potential antioxidant indoleamine. The present study was undertaken to investigate whether long-term melatonin treatment can induce reproductive alterations and if it can protect ovarian tissue against lipid peroxidation during ovulation. Twenty-four adult female Wistar rats, 60 days old (± 250-260 g), were randomly divided into two equal groups. The control group received 0.3 mL 0.9% NaCl + 0.04 mL 95% ethanol as vehicle, and the melatonin-treated group received vehicle + melatonin (100 µg·100 g body weight(-1)·day(-1)) both intraperitoneally daily for 60 days. All animals were killed by decapitation during the morning estrus at 4:00 am. Body weight gain and body mass index were reduced by melatonin after 10 days of treatment (P < 0.05). Also, a marked loss of appetite was observed with a fall in food intake, energy intake (melatonin 51.41 ± 1.28 vs control 57.35 ± 1.34 kcal/day) and glucose levels (melatonin 80.3 ± 4.49 vs control 103.5 ± 5.47 mg/dL) towards the end of treatment. Melatonin itself and changes in energy balance promoted reductions in ovarian mass (20.2%) and estrous cycle remained extensive (26.7%), arresting at diestrus. Regarding the oxidative profile, lipid hydroperoxide levels decreased after melatonin treatment (6.9%) and total antioxidant substances were enhanced within the ovaries (23.9%). Additionally, melatonin increased superoxide dismutase (21.3%), catalase (23.6%) and glutathione-reductase (14.8%) activities and the reducing power (10.2% GSH/GSSG ratio). We suggest that melatonin alters ovarian mass and estrous cyclicity and protects the ovaries by increasing superoxide dismutase, catalase and glutathione-reductase activities. PMID:21344135
NASA Astrophysics Data System (ADS)
Accomazzi, Alberto; Henneken, E.; Grant, C. S.; Kurtz, M. J.; Di Milia, G.; Luker, J.; Thompson, D. M.; Bohlen, E.; Murray, S. S.
2011-05-01
ADS Labs is a platform that ADS is introducing in order to test and receive feedback from the community on new technologies and prototype services. Currently, ADS Labs features a new interface for abstract searches, faceted filtering of results, visualization of co-authorship networks, article-level recommendations, and a full-text search service. The streamlined abstract search interface provides a simple, one-box search with options for ranking results based on a paper relevancy, freshness, number of citations, and downloads. In addition, it provides advanced rankings based on collaborative filtering techniques. The faceted filtering interface allows users to narrow search results based on a particular property or set of properties ("facets"), allowing users to manage large lists and explore the relationship between them. For any set or sub-set of records, the co-authorship network can be visualized in an interactive way, offering a view of the distribution of contributors and their inter-relationships. This provides an immediate way to detect groups and collaborations involved in a particular research field. For a majority of papers in Astronomy, our new interface will provide a list of related articles of potential interest. The recommendations are based on a number of factors, including text similarity, citations, and co-readership information. The new full-text search interface allows users to find all instances of particular words or phrases in the body of the articles in our full-text archive. This includes all of the scanned literature in ADS as well as a select portion of the current astronomical literature, including ApJ, ApJS, AJ, MNRAS, PASP, A&A, and soon additional content from Springer journals. Fulltext search results include a list of the matching papers as well as a list of "snippets" of text highlighting the context in which the search terms were found. ADS Labs is available at http://adslabs.org
Marsico, Alyssa L M; Elci, Gokhan S; Moyano, Daniel F; Yesilbag Tonga, Gulen; Duncan, Bradley; Landis, Ryan F; Rotello, Vincent M; Vachet, Richard W
2015-12-15
Laser desorption/ionization mass spectrometry (LDI-MS) has been used to detect gold nanoparticles (AuNPs) in biological samples, such as cells and tissues, by ionizing their attached monolayer ligands. Many NP-attached ligands, however, are difficult to ionize by LDI, making it impossible to track these NPs in biological samples. In this work, we demonstrate that concentrations of matrix-assisted LDI (MALDI) matrices an order of magnitude below the values typically used in MALDI can facilitate the selective detection of AuNPs with these ligands, even in samples as complex as cell lysate. This enhanced sensitivity arises from a synergistic relationship between the gold core and the matrix that helps to selectively ionize ligands attached to the AuNPs. PMID:26560844
Sartorio, A; Narici, M V; Fumagalli, E; Faglia, G; Lafortuna, C L
2001-02-01
The cardiovascular response to an aerobic cycloergometer exercise test (ACET, 15 min at 60 W, 60 rpm) and the maximally attainable muscle power output, assessed by a stair climbing test (SCT), were evaluated in 60 obese patients (41 females and 19 males; age: 18-68 yr; body mass index, BMI: 40.8+/-4.8 kg/m2) before and after a 3-week body mass reduction (BMR) program, entailing integrated energy-restricted diet (1200-1500 kcal/day), low-grade aerobic exercise conditioning and individual and/or group psychological therapy. The daily conditioning protocol (5 days/week) consisted of: 1) 30 min of indoor jogging and dynamic aerobic standing and floor exercises performed with arms and legs, under the guidance of a therapist; 2) 30 min of cycloergometer exercise at 60 W; and/or 3) 4-km outdoor leisure walking on flat terrain. Three weeks of BMR program induced a significant weight loss (-4.5 %; p<0.001), a reduction of systolic (-11+/-14 mmHg, -7.3%,p<0.001) and diastolic (-7+/-9 mmHg, -7.3%,p<0.001) resting arterial blood pressure, as well as a reduction of heart rate at rest (-18.6%,p<0.001), during ACET (-11.3%,p<0.001) and 5 min thereafter (-14.8%,p<0.001). The subjective rating of perceived exertion in terms of breathlessness and general fatigue during ACET, scored on a 0-100 visual analogic scale, was significantly reduced (p<0.001) after BMR program. A 11.2% decrease in SCT time (p<0.001) was also observed, corresponding to a 9.6% increase (p<0.001) in average muscle power (W) and 14.6% increase (p<0.001) in specific muscle power (W.kg(-1)). In conclusion, a combination of energy restricted diet, low intensity aerobic exercise and psychological counselling appears to significantly improve both aerobic and anaerobic performance in morbidly obese subjects. Different factors (ie, reduction of body mass, shift in the balance between parasympathetic and sympathetic activity, a weight-loss dependent shift toward a more favourable region of the muscle power
The AdS3 × S3 × S3 × S1 Hernández-López phases: a semiclassical derivation
NASA Astrophysics Data System (ADS)
Abbott, Michael C.
2013-11-01
This note calculates the Hernández-López phases for strings in AdS3 × S3 × S3 × S1 by semiclassical methods using the d(2, 1; α)2 algebraic curve. By working at general α we include modes absent from previous semiclassical calculations of this phase in AdS3 × S3 × T4, and in particular can study the scattering of particles of different mass. By carefully re-deriving the semiclassical formula we clarify some issues of antisymmetrization, cutoffs and surface terms which could safely be ignored in AdS5 × S5, and some issues about the terms c1, s which were absent there. As a result we see agreement with the recently calculated all-loop dressing phase in the AdS3 × S3 × T4 case, and exactly 1/2 this in the general case AdS3 × S3 × S3 × S1, for any α and any (light) polarizations.
Sartorio, A; Fontana, P; Trecate, L; Lafortuna, C L
2003-04-01
The effects of a short-term (3-week) integrated body weight reduction (BWR) program on fatigue perception and on lower limb anaerobic power output were evaluated in 200 severely obese in-patients (40 males and 160 females, age: 18-83 yr, BMI: 35.0-65.3 kg/m2). Fatigue was assessed by a 7-point Likert-type scale questionnaire (Fatigue Severity Scale, FSS), while average lower limb power output (W) during a maximal effort was determined with a modification of the Margaria test for stair climbing. In both genders, total FSS score was influenced by both age and obesity level, resulting significantly (p < 0.001) lower in younger subjects (< 45 yr) than in older (> 45 yr) and in patients with lower BMI (< 40 kg/m2) than in those with a higher one (> 40 kg/m2). An opposite trend was observed in W. The 3-week BWR integrated program with moderate aerobic exercise and free standing and ground gymnastic routines induced a significant reduction in body weight (p < 0.001), in total FSS score (p < 0.001) and a significant increase in W, both in absolute terms (p < 0.05) and relative to body mass (p < 0.001). Total FSS score and absolute or relative power output were positively correlated both before and after the BWR program (p < 0.001, Wilcoxon rank test). It is concluded that: a) subjective fatigue perception, assessed by a FSS questionnaire, can be considered an indirect indicator of effective lower limb power output in severely obese patients and, b) in spite of a relatively small, although significant, decline of BMI, the full-time participation in a hospital-based, integrated BWR program with moderate exercise activity is associated with significant short-term improvements of both fatigue sensation and power output. Dia PMID:12846447
Brusseau, M L; Matthieu, D E; Carroll, K C; Mainhagu, J; Morrison, C; McMillan, A; Russo, A; Plaschke, M
2013-06-01
The objective of this study was to characterize the temporal behavior of contaminant mass discharge, and the relationship between reductions in contaminant mass discharge and reductions in contaminant mass, for a very heterogeneous, highly contaminated source-zone field site. Trichloroethene is the primary contaminant of concern, and several lines of evidence indicate the presence of organic liquid in the subsurface. The site is undergoing groundwater extraction for source control, and contaminant mass discharge has been monitored since system startup. The results show a significant reduction in contaminant mass discharge with time, decreasing from approximately 1 to 0.15 kg/d over five years. Two methods were used to estimate the mass of contaminant present in the source area at the initiation of the remediation project. One was based on a comparison of two sets of core data, collected 3.5 years apart, which suggests that a significant (~80%) reduction in aggregate sediment-phase TCE concentrations occurred between sampling events. The second method was based on fitting the temporal contaminant mass discharge data with a simple exponential source-depletion function. Relatively similar estimates, 784 and 993 kg, respectively, were obtained with the two methods. These data were used to characterize the relationship between reductions in contaminant mass discharge (CMDR) and reductions in contaminant mass (MR). The observed curvilinear relationship exhibits a reduction in contaminant mass discharge essentially immediately upon the initiation of mass reduction. This behavior is consistent with a system wherein significant quantities of mass are present in hydraulically poorly accessible domains for which mass removal is influenced by rate-limited mass transfer. The results obtained from the present study are compared to those obtained from other field studies to evaluate the impact of system properties and conditions on mass-discharge and mass-removal behavior. The
Matthieu, D.E.; Carroll, K.C.; Mainhagu, J.; Morrison, C.; McMillan, A.; Russo, A.; Plaschke, M.
2013-01-01
The objective of this study was to characterize the temporal behavior of contaminant mass discharge, and the relationship between reductions in contaminant mass discharge and reductions in contaminant mass, for a very heterogeneous, highly contaminated source-zone field site. Trichloroethene is the primary contaminant of concern, and several lines of evidence indicate the presence of organic liquid in the subsurface. The site is undergoing groundwater extraction for source control, and contaminant mass discharge has been monitored since system startup. The results show a significant reduction in contaminant mass discharge with time, decreasing from approximately 1 to 0.15 kg/d. Two methods were used to estimate the mass of contaminant present in the source area at the initiation of the remediation project. One was based on a comparison of two sets of core data, collected 3.5 years apart, which suggests that a significant (~80%) reduction in aggregate sediment-phase TCE concentrations occurred between sampling events. The second method was based on fitting the temporal contaminant mass discharge data with a simple exponential source-depletion function. Relatively similar estimates, 784 and 993 kg, respectively, were obtained with the two methods. These data were used to characterize the relationship between reductions in contaminant mass discharge (CMDR) and reductions in contaminant mass (MR). The observed curvilinear relationship exhibits a reduction in contaminant mass discharge essentially immediately upon initiation of mass reduction. This behavior is consistent with a system wherein significant quantities of mass are present in hydraulically poorly accessible domains for which mass removal is influenced by rate-limited mass transfer. The results obtained from the present study are compared to those obtained from other field studies to evaluate the impact of system properties and conditions on mass-discharge and mass-removal behavior. The results indicated that
NASA Astrophysics Data System (ADS)
Costa, Miguel S.; Greenspan, Lauren; Oliveira, Miguel; Penedones, João; Santos, Jorge E.
2016-06-01
We consider solutions in Einstein-Maxwell theory with a negative cosmological constant that asymptote to global AdS 4 with conformal boundary {S}2× {{{R}}}t. At the sphere at infinity we turn on a space-dependent electrostatic potential, which does not destroy the asymptotic AdS behaviour. For simplicity we focus on the case of a dipolar electrostatic potential. We find two new geometries: (i) an AdS soliton that includes the full backreaction of the electric field on the AdS geometry; (ii) a polarised neutral black hole that is deformed by the electric field, accumulating opposite charges in each hemisphere. For both geometries we study boundary data such as the charge density and the stress tensor. For the black hole we also study the horizon charge density and area, and further verify a Smarr formula. Then we consider this system at finite temperature and compute the Gibbs free energy for both AdS soliton and black hole phases. The corresponding phase diagram generalizes the Hawking-Page phase transition. The AdS soliton dominates the low temperature phase and the black hole the high temperature phase, with a critical temperature that decreases as the external electric field increases. Finally, we consider the simple case of a free charged scalar field on {S}2× {{{R}}}t with conformal coupling. For a field in the SU(N ) adjoint representation we compare the phase diagram with the above gravitational system.
New boundary conditions for AdS3
NASA Astrophysics Data System (ADS)
Compère, Geoffrey; Song, Wei; Strominger, Andrew
2013-05-01
New chiral boundary conditions are found for quantum gravity with matter on AdS3. The associated asymptotic symmetry group is generated by a single right-moving U(1) Kac-Moody-Virasoro algebra with {c_R}={3ℓ}/2G . The Kac-Moody zero mode generates global left-moving translations and equals, for a BTZ black hole, the sum of the total mass and spin. The level is positive about the global vacuum and negative in the black hole sector, corresponding to ergosphere formation. Realizations arising in Chern-Simons gravity and string theory are analyzed. The new boundary conditions are shown to naturally arise for warped AdS3 in the limit that the warp parameter is taken to zero.
NASA Astrophysics Data System (ADS)
Peltier, Aline; Got, Jean-Luc; Villeneuve, Nicolas; Boissier, Patrice; Staudacher, Thomas; Ferrazzini, Valérie; Walpersdorf, Andrea
2015-03-01
Basaltic volcanoes are among the largest volcanic edifices on the Earth. These huge volcanoes exhibit rift zones and mobile flanks, revealing specific stress field conditions. In this paper, we present new deformation data issued from the Global Navigation Satellite Systems (GNSS) network installed on Piton de la Fournaise. Density of the GNSS stations allowed us to reach a sufficient resolution to perform a spatially significant analysis of strain at the scale of the active part of the volcano. Since 2007, summit inflation during preeruptive/eruptive sequences (summit extension/cone flanks contraction) alternates with summit deflation during posteruptive/rest periods (summit contraction/cone flanks extension) and generates a "pulsation" of the volcano. This volcano "pulsation" increases rock fracturing and damage, decreases the rock stiffness, and increases the medium permeability. The deformation regime of the mobile eastern flank evidences mass transfer in depth from the summit to the east. During the long-term summit deflation recorded between 2011 and 2014, the upper eastern flank extended steadily eastward whereas the lower eastern flank contracted. Simultaneous extension and eastward displacement of the upper eastern flank and eastward contraction of the middle and lower eastern flank contributes to build the Grandes Pentes relief, steeping the topographic slope. We relate the eastern flank topographic slope spatial variations to rock or basal friction angle changes. The lower flank contraction process is an evidence of its progressive loading by the upper eastern flank, which brings this flank closer to an eventual instability.
Payne, Jonathan L; Jost, Adam B; Wang, Steve C; Skotheim, Jan M
2013-03-01
Size is among the most important traits of any organism, yet the factors that control its evolution remain poorly understood. In this study, we investigate controls on the evolution of organismal size using a newly compiled database of nearly 25,000 foraminiferan species and subspecies spanning the past 400 million years. We find a transition in the pattern of foraminiferan size evolution from correlation with atmospheric pO2 during the Paleozoic (400-250 million years ago) to long-term stasis during the post-Paleozoic (250 million years ago to present). Thus, a dramatic shift in the evolutionary mode coincides with the most severe biotic catastrophe of the Phanerozoic (543 million years ago to present). Paleozoic tracking of pO2 was confined to Order Fusulinida, whereas Paleozoic lagenides, miliolids, and textulariids were best described by the stasis model. Stasis continued to best describe miliolids and textulariids during post-Paleozoic time, whereas random walk was the best supported mode for the other diverse orders. The shift in evolutionary dynamics thus appears to have resulted primarily from the selective elimination of fusulinids at the end of the Permian Period. These findings illustrate the potential for mass extinction to alter macroevolutionary dynamics for hundreds of millions of years. PMID:23461330
On conserved charges and thermodynamics of the AdS4 dyonic black hole
NASA Astrophysics Data System (ADS)
Cárdenas, Marcela; Fuentealba, Oscar; Matulich, Javier
2016-05-01
We consider four-dimensional gravity in the presence of a dilatonic scalar field and an Abelian gauge field. This theory corresponds to the bosonic sector of a Kaluza-Klein reduction of eleven-dimensional supergravity which induces a specific self-interacting potential for the scalar field. We compute the conserved charges and carry out the thermodynamics of an anti-de Sitter (AdS) dyonic black hole solution that was proposed recently. The charges coming from symmetries of the action are computed using the Regge-Teitelboim Hamiltonian approach. They correspond to the mass, which acquires contributions from the scalar field, and the electric charge. We introduce integrability conditions because the scalar field leads to non-integrable terms in the variation of the mass. These conditions are generically solved by introducing boundary conditions that relate the leading and subleading terms of the scalar field fall-off. The Hamiltonian Euclidean action, computed in the grand canonical ensemble, is obtained by demanding the action to have an extremum. Its value is given by a radial boundary term plus an additional polar angle boundary term due to the presence of a magnetic monopole. Remarkably, the magnetic charge can be identified from the variation of the additional polar angle boundary term, confirming that the first law of black hole thermodynamics is a consequence of having a well-defined and finite Hamiltonian action principle, even if the charge does not come from a symmetry of the action. The temperature and electrostatic potential are determined by demanding regularity of the black hole solution, whereas the value of the magnetic potential is determined by the variation of the additional polar angle boundary term. Consequently, the first law of black hole thermodynamics is identically satisfied by construction.
Value Added and Other Related Matters.
ERIC Educational Resources Information Center
Whitla, Dean K.
The term "value added" refers to the assessment of the amount of learning that takes place during the college years. Two experiments, Value Added I and Value Added II, attempted to measure college students' attainment of eight liberal education objectives: (1) writing ability; (2) analytical ability; (3) sensitivity to ethics, morals, and values;…
NASA Astrophysics Data System (ADS)
Taylor, F. W.; Thirumalai, K.; Lavier, L. L.; Frohlich, C.; Shen, C.; WU, C.; Sun, H.; Papabatu, A. K.
2013-12-01
The processes of forearc deformation and their relation to the megathrust earthquake cycle provide critical insights regarding longer-term arc tectonic evolution and the earthquake cycle itself. At the Western Solomon Islands arc, Ranongga and other islands sit over the seismogenic megathrust as close as 4 km from the trench where the Australian plate converges at ~80-100 mm/yr. Coral reefs fringe the coasts and record the relative sea level changes accompanying both long-term tectonic uplift and the shorter-term earthquake cycle. The AD 2007 Mw 8.1 megathrust rupture zone dips from 1-2 km to ~25 km deep beneath islands and caused uplift that we measured at coasts along a profile normal to the arc trend. Vertical components of the 2007 displacement show the expected fairly smooth uplift profile typical of elastic strain release. In contrast, along the same profile the amounts of longer-term net uplift of the mid-Holocene (~6 ka) coral shoreline are more variable. Likewise, the elevations of individual coral paleo-shorelines recording a series of individual uplifts (as young as 600 yr old with ~2.25 m uplift) also indicate variable amounts of uplift along the profile when compared to the 2007 coseismic uplift. For 50 -100 yr before 2007, all sites along the same profile subsided at rates on the order of 1-3 cm/yr, all of which equaled or exceeded the upward growth rates of corals. However, the amounts of pre-2007 subsidence are highly variable along the profile and do not conform well to the smoother profile of the 2007 displacements. Where total uplift since the mid-Holocene is smaller, pre-2007 subsidence and 2007 uplift may be relatively large. Where total uplift since the mid-Holocene is larger, 2007 coseismic uplift may be large while pre-2007 subsidence is relatively small. Therefore, the differences in longer-term uplift rates appear tied to variable subsidence during the interseismic period rather than being primarily a coseismic phenomenon. Furthermore
Lorentzian AdS geometries, wormholes, and holography
Arias, Raul E.; Silva, Guillermo A.; Botta Cantcheff, Marcelo
2011-03-15
We investigate the structure of two-point functions for the quantum field theory dual to an asymptotically Lorentzian Anti de Sitter (AdS) wormhole. The bulk geometry is a solution of five-dimensional second-order Einstein-Gauss-Bonnet gravity and causally connects two asymptotically AdS spacetimes. We revisit the Gubser-Klebanov-Polyakov-Witten prescription for computing two-point correlation functions for dual quantum field theories operators O in Lorentzian signature and we propose to express the bulk fields in terms of the independent boundary values {phi}{sub 0}{sup {+-}} at each of the two asymptotic AdS regions; along the way we exhibit how the ambiguity of normalizable modes in the bulk, related to initial and final states, show up in the computations. The independent boundary values are interpreted as sources for dual operators O{sup {+-}} and we argue that, apart from the possibility of entanglement, there exists a coupling between the degrees of freedom living at each boundary. The AdS{sub 1+1} geometry is also discussed in view of its similar boundary structure. Based on the analysis, we propose a very simple geometric criterion to distinguish coupling from entanglement effects among two sets of degrees of freedom associated with each of the disconnected parts of the boundary.
Conserved charges in timelike warped AdS3 spaces
NASA Astrophysics Data System (ADS)
Donnay, L.; Fernández-Melgarejo, J. J.; Giribet, G.; Goya, A.; Lavia, E.
2015-06-01
We consider the timelike version of warped anti-de Sitter space (WAdS), which corresponds to the three-dimensional section of the Gödel solution of four-dimensional cosmological Einstein equations. This geometry presents closed timelike curves (CTCs), which are inherited from its four-dimensional embedding. In three dimensions, this type of solution can be supported without matter provided the graviton acquires mass. Here, among the different ways to consistently give mass to the graviton in three dimensions, we consider the parity-even model known as new massive gravity (NMG). In the bulk of timelike WAdS3 space, we introduce defects that, from the three-dimensional point of view, represent spinning massive particlelike objects. For this type of source, we investigate the definition of quasilocal gravitational energy as seen from infinity, far beyond the region where the CTCs appear. We also consider the covariant formalism applied to NMG to compute the mass and the angular momentum of spinning particlelike defects and compare the result with the one obtained by means of the quasilocal stress tensor. We apply these methods to special limits in which the WAdS3 solutions coincide with locally AdS3 and locally AdS2×R spaces. Finally, we make some comments about the asymptotic symmetry algebra of asymptotically WAdS3 spaces in NMG.
NASA Astrophysics Data System (ADS)
Belin, Alexandre; Castro, Alejandra; Hung, Ling-Yan
2015-11-01
We discuss properties of interpolating geometries in three dimensional gravity in the presence of a chiral anomaly. This anomaly, which introduces an unbalance between left and right central charges, is protected under RG flows. For this simple reason it is impossible to gap a system with such an anomaly. Our goal is to discuss how holography captures this basic and robust feature. We demonstrate the absence of a mass gap by analysing the linearized spectrum and holographic entanglement entropy of these backgrounds in the context of AdS3/CFT2.
NASA Astrophysics Data System (ADS)
Alexander, Poul E. R.; Gieles, Mark; Lamers, Henny J. G. L. M.; Baumgardt, Holger
2014-08-01
We present a new version of the fast star cluster evolution code EVOLVE ME A CLUSTER OF STARS (EMACSS). While previous versions of EMACSS reproduced clusters of single-mass stars, this version models clusters with an evolving stellar content. Stellar evolution dominates early evolution, and leads to: (1) reduction of the mean mass of stars due to the mass loss of high-mass stars; (2) expansion of the half-mass radius; (3) for (nearly) Roche Volume filling clusters, the induced escape of stars. Once sufficient relaxation has occurred (≃10 relaxation times-scales), clusters reach a second, `balanced' state whereby the core releases energy as required by the cluster as a whole. In this state: (1) stars escape due to tidal effects faster than before balanced evolution; (2) the half-mass radius expands or contracts depending on the Roche volume filling factor; and (3) the mean mass of stars increases due to the preferential ejection of low-mass stars. We compare the EMACSS results of several cluster properties against N-body simulations of clusters spanning a range of initial number of stars, mass, half-mass radius, and tidal environments, and show that our prescription accurately predicts cluster evolution for this data base. Finally, we consider applications for EMACSS, such as studies of galactic globular cluster populations in cosmological simulations.
Smeared antibranes polarise in AdS
NASA Astrophysics Data System (ADS)
Gautason, Fridrik Freyr; Truijen, Brecht; Van Riet, Thomas
2015-07-01
In the recent literature it has been questioned whether the local backreaction of antibranes in flux throats can induce a perturbative brane-flux decay. Most evidence for this can be gathered for D6 branes and D p branes smeared over 6 - p compact directions, in line with the absence of finite temperature solutions for these cases. The solutions in the literature have flat worldvolume geometries and non-compact transversal spaces. In this paper we consider what happens when the worldvolume is AdS and the transversal space is compact. We show that in these circumstances brane polarisation smoothens out the flux singularity, which is an indication that brane-flux decay is prevented. This is consistent with the fact that the cosmological constant would be less negative after brane-flux decay. Our results extend recent results on AdS7 solutions from D6 branes to AdS p+1 solutions from D p branes. We show that supersymmetry of the AdS solutions depend on p non-trivially.
Technology Transfer Automated Retrieval System (TEKTRAN)
Long-term effects of Kamp K'aana, a 2-week residential weight management camp, on body mass index (BMI) measures were evaluated on 71 of 108 (66%) obese youth 10 to 14 years of age. Measures were obtained at 11-month study follow-up (n=38) or extracted from medical record (n=33). Compared with basel...
NASA Astrophysics Data System (ADS)
Endo, Motoi; Yamaguchi, Masahiro; Yoshioka, Koichi
2005-07-01
The physics of moduli fields is examined in the scenario where the gravitino is relatively heavy with mass of order 10 TeV, which is favored in view of the severe gravitino problem. The form of the moduli superpotential is shown to be determined, if one imposes a phenomenological requirement that no physical CP phase arise in gaugino masses from conformal anomaly mediation. This bottom-up approach allows only two types of superpotential, each of which can have its origins in a fundamental underlying theory such as superstring. One superpotential is the sum of an exponential and a constant, which is identical to that obtained by Kachru et al. (KKLT), and the other is the racetrack superpotential with two exponentials. The general form of soft supersymmetry-breaking masses is derived, and the pattern of the superparticle mass spectrum in the minimal supersymmetric standard model is discussed with the KKLT-type superpotential. It is shown that the moduli mediation and the anomaly mediation make comparable contributions to the soft masses. At the weak scale, the gaugino masses are rather degenerate compared to the minimal supergravity, which bring characteristic features on the superparticle masses. In particular, the lightest neutralino, which often constitutes the lightest superparticle and thus a dark matter candidate, is a considerable admixture of gauginos and Higgsinos. We also find a small mass hierarchy among the moduli, gravitino, and superpartners of the standard-model fields. Cosmological implications of the scenario are briefly described.
ERIC Educational Resources Information Center
Kathman, Jacob D.; Wood, Reed M.
2011-01-01
How do third-party interventions affect the severity of mass killings? The authors theorize that episodes of mass killing are the consequence of two factors: (1) the threat perceptions of the perpetrators and (2) the cost of implementing genocidal policies relative to other alternatives. To reduce genocidal hostilities, interveners must address…
Technology Transfer Automated Retrieval System (TEKTRAN)
Bite mass is a fundamental element of ruminant ingestive behavior and is highly influenced by sward structure. We compared the sward structure of four grasses and related structure to the bite mass of cattle grazing the grasses. Reed canarygrass (RCG; Phalaris arundinacea L), quackgrass (QG; Elytri...
Higher-derivative superparticle in AdS3 space
NASA Astrophysics Data System (ADS)
Kozyrev, Nikolay; Krivonos, Sergey; Lechtenfeld, Olaf
2016-03-01
Employing the coset approach we construct component actions for a superparticle moving in AdS3 with N =(2 ,0 ), D =3 supersymmetry partially broken to N =2 , d =1 . These actions may contain higher time-derivative terms, which are chosen to possess the same (super)symmetries as the free superparticle. In terms of the nonlinear-realization superfields, the component actions always take a simpler form when written in terms of covariant Cartan forms. We also consider in detail the reduction to the nonrelativistic case and construct the corresponding action of a Newton-Hooke superparticle and its higher-derivative generalizations. The structure of these higher time-derivative generalizations is completely fixed by invariance under the supersymmetric Newton-Hooke algebra extended by two central charges.
2014-01-01
Background There is a strong association between weight gain and metabolic events in patients with schizophrenia receiving many of the second-generation antipsychotic agents. We explored the relationship between body mass index (BMI) and metabolic events in patients with schizophrenia receiving long-acting injectable paliperidone palmitate (PP) in a long-term trial. Methods We conducted a post hoc analysis of data from a PP study that included a 33-week open-label transition (TR) and maintenance phase; a variable duration, randomized, double-blind (DB), placebo-controlled phase and a 52-week open-label extension (OLE) phase. Overall, 644 patients received PP continuously from study entry through discontinuation or study completion and were grouped by baseline BMI (kg/m2): underweight (BMI <19; n = 29, 4.5%), normal-weight (BMI 19- < 25; n = 229, 35.6%), overweight (BMI 25- < 30; n = 232, 36.0%) and obese (BMI ≥30; n = 154, 23.9%). Metabolic treatment-emergent adverse events (TEAEs) and changes in related laboratory results from TR baseline were analyzed. Results PP exposure was similar across BMI groups; overall mean (SD) dose/month was 70.3 (17.17) mg eq. [109.6 (26.78) mg]; median duration of exposure was 204 days (6 to 1009 days). Occurrences of metabolic TEAEs overall by group were 0% (underweight), 14.9% (normal-weight), 14.7% (overweight), and 24.0% (obese). The most common (≥2%) metabolic TEAE were weight gain and elevated blood levels of glucose, lipids, and insulin. Mean BMI and weight increased in normal-weight and overweight groups at DB endpoint, and in underweight, normal-weight and overweight groups at OLE endpoint (p ≤0.05). No consistent trend for increased metabolic-related laboratory values by baseline BMI group was observed. Homeostatic model assessments for insulin resistance indicated preexisting insulin resistance at baseline, with minimal changes at OLE endpoint across baseline BMI groups. Conclusion
Bernstein, D.M.; Rogers, R.A.; Sepulveda, R.; Kunzendorf, P.; Bellmann, B.; Ernst, H.; Creutzenberg, O.; Phillips, J.I.
2015-02-15
This study was designed to provide an understanding of the biokinetics and potential toxicology in the lung and pleura following inhalation of brake dust following short term exposure in rats. The deposition, translocation and pathological response of brake-dust derived from brake pads manufactured with chrysotile were evaluated in comparison to the amphibole, crocidolite asbestos. Rats were exposed by inhalation 6 h/day for 5 days to either brake-dust obtained by sanding of brake-drums manufactured with chrysotile, a mixture of chrysotile and the brake-dust or crocidolite asbestos. The chrysotile fibers were relatively biosoluble whereas the crocidolite asbestos fibers persisted through the life-time of the animal. This was reflected in the lung and the pleura where no significant pathological response was observed at any time point in the brake dust or chrysotile/brake dust exposure groups through 365 days post exposure. In contrast, crocidolite asbestos produced a rapid inflammatory response in the lung parenchyma and the pleura, inducing a significant increase in fibrotic response in both of these compartments. Crocidolite fibers were observed embedded in the diaphragm with activated mesothelial cells immediately after cessation of exposure. While no chrysotile fibers were found in the mediastinal lymph nodes, crocidolite fibers of up to 35 μm were observed. These results provide support that brake-dust derived from chrysotile containing brake drums would not initiate a pathological response in the lung or the pleural cavity following short term inhalation. - Highlights: • Evaluated brake dust w/wo added chrysotile in comparison to crocidolite asbestos. • Persistence, translocation, pathological response in the lung and pleural cavity. • Chrysotile cleared rapidly from the lung while the crocidolite asbestos persisted. • No significant pathology in lung or pleural cavity observed at any time point in the brake-dust groups. • Crocidolite quickly
The AdS central charge in string theory
NASA Astrophysics Data System (ADS)
Troost, Jan
2011-11-01
We evaluate the vacuum expectation value of the central charge operator in string theory in an AdS3 vacuum. Our calculation provides a rare non-zero one-point function on a spherical worldsheet. The evaluation involves the regularization both of a worldsheet ultraviolet divergence (associated to the infinite volume of the conformal Killing group), and a space-time infrared divergence (corresponding to the infinite volume of space-time). The two divergences conspire to give a finite result, which is the classical general relativity value for the central charge, corrected in bosonic string theory by an infinite series of tree level higher derivative terms.
Small black holes in global AdS spacetime
NASA Astrophysics Data System (ADS)
Jokela, Niko; Pönni, Arttu; Vuorinen, Aleksi
2016-04-01
We study the properties of two-point functions and quasinormal modes in a strongly coupled field theory holographically dual to a small black hole in global anti-de Sitter spacetime. Our results are seen to smoothly interpolate between known limits corresponding to large black holes and thermal AdS space, demonstrating that the Son-Starinets prescription works even when there is no black hole in the spacetime. Omitting issues related to the internal space, the results can be given a field theory interpretation in terms of the microcanonical ensemble, which provides access to energy densities forbidden in the canonical description.
Ellenbroek, Johanne H; van Dijck, Laura; Töns, Hendrica A; Rabelink, Ton J; Carlotti, Françoise; Ballieux, Bart E P B; de Koning, Eelco J P
2014-03-01
High-fat, low-carbohydrate ketogenic diets (KD) are used for weight loss and for treatment of refractory epilepsy. Recently, short-time studies in rodents have shown that, besides their beneficial effect on body weight, KD lead to glucose intolerance and insulin resistance. However, the long-term effects on pancreatic endocrine cells are unknown. In this study we investigate the effects of long-term KD on glucose tolerance and β- and α-cell mass in mice. Despite an initial weight loss, KD did not result in weight loss after 22 wk. Plasma markers associated with dyslipidemia and inflammation (cholesterol, triglycerides, leptin, monocyte chemotactic protein-1, IL-1β, and IL-6) were increased, and KD-fed mice showed signs of hepatic steatosis after 22 wk of diet. Long-term KD resulted in glucose intolerance that was associated with insufficient insulin secretion from β-cells. After 22 wk, insulin-stimulated glucose uptake was reduced. A reduction in β-cell mass was observed in KD-fed mice together with an increased number of smaller islets. Also α-cell mass was markedly decreased, resulting in a lower α- to β-cell ratio. Our data show that long-term KD causes dyslipidemia, a proinflammatory state, signs of hepatic steatosis, glucose intolerance, and a reduction in β- and α-cell mass, but no weight loss. This indicates that long-term high-fat, low-carbohydrate KD lead to features that are also associated with the metabolic syndrome and an increased risk for type 2 diabetes in humans. PMID:24398402
ERIC Educational Resources Information Center
Schlesinger, Traci
2011-01-01
This study examines the effects of mandatory terms and sentencing enhancements on Black and White men's state-level prison admission rates. Four major findings emerge from the analysis. First, both mandatory terms and sentencing enhancements increase prison admission rates for Black and White men. Second, these policies disproportionately increase…
Light-Front Quantization and AdS/QCD: An Overview
de Teramond, Guy F.; Brodsky, Stanley J.; /SLAC /Stanford U., Phys. Dept.
2011-08-19
We give an overview of the light-front holographic approach to strongly coupled QCD, whereby a confining gauge theory, quantized on the light front, is mapped to a higher-dimensional anti de Sitter (AdS) space. The framework is guided by the AdS/CFT correspondence incorporating a gravitational background asymptotic to AdS space which encodes the salient properties of QCD, such as the ultraviolet conformal limit at the AdS boundary at z {yields} 0, as well as modifications of the geometry in the large z infrared region to describe confinement and linear Regge behavior. There are two equivalent procedures for deriving the AdS/QCD equations of motion: one can start from the Hamiltonian equation of motion in physical space time by studying the off-shell dynamics of the bound state wavefunctions as a function of the invariant mass of the constituents. To a first semiclassical approximation, where quantum loops and quark masses are not included, this leads to a light-front Hamiltonian equation which describes the bound state dynamics of light hadrons in terms of an invariant impact variable {zeta} which measures the separation of the partons within the hadron at equal light-front time. Alternatively, one can start from the gravity side by studying the propagation of hadronic modes in a fixed effective gravitational background. Both approaches are equivalent in the semiclassical approximation. This allows us to identify the holographic variable z in AdS space with the impact variable {zeta}. Light-front holography thus allows a precise mapping of transition amplitudes from AdS to physical space-time. The internal structure of hadrons is explicitly introduced and the angular momentum of the constituents plays a key role.
Ultraviolet asymptotics and singular dynamics of AdS perturbations
NASA Astrophysics Data System (ADS)
Craps, Ben; Evnin, Oleg; Vanhoof, Joris
2015-10-01
Important insights into the dynamics of spherically symmetric AdS-scalar field perturbations can be obtained by considering a simplified time-averaged theory accurately describing perturbations of amplitude ɛ on time-scales of order 1/ ɛ 2. The coefficients of the time-averaged equations are complicated expressions in terms of the AdS scalar field mode functions, which are in turn related to the Jacobi polynomials. We analyze the behavior of these coefficients for high frequency modes. The resulting asymptotics can be useful for understanding the properties of the finite-time singularity in solutions of the time-averaged theory recently reported in the literature. We highlight, in particular, the gauge dependence of this asymptotics, with respect to the two most commonly used gauges. The harsher growth of the coefficients at large frequencies in higher-dimensional AdS suggests strengthening of turbulent instabilities in higher dimensions. In the course of our derivations, we arrive at recursive relations for the coefficients of the time-averaged theory that are likely to be useful for evaluating them more efficiently in numerical simulations.
Short-term variability and mass loss in Be stars. I. BRITE satellite photometry of η and μ Centauri
NASA Astrophysics Data System (ADS)
Baade, D.; Rivinius, Th.; Pigulski, A.; Carciofi, A. C.; Martayan, Ch.; Moffat, A. F. J.; Wade, G. A.; Weiss, W. W.; Grunhut, J.; Handler, G.; Kuschnig, R.; Mehner, A.; Pablo, H.; Popowicz, A.; Rucinski, S.; Whittaker, G.
2016-04-01
Context. Empirical evidence for the involvement of nonradial pulsations (NRPs) in the mass loss from Be stars ranges from (i) a singular case (μ Cen) of repetitive mass ejections triggered by multi-mode beating to (ii) several photometric reports about enormous numbers of pulsation modes that suddenly appear during outbursts and on to (iii) effective single-mode pulsators. Aims: The purpose of this study is to develop a more detailed empirical description of the star-to-disk mass transfer and to check the hypothesis that spates of transient nonradial pulsation modes accompany and even drive mass-loss episodes. Methods: The BRITE Constellation of nanosatellites was used to obtain mmag photometry of the Be stars η and μ Cen. Results: In the low-inclination star μ Cen, light pollution by variable amounts of near-stellar matter prevented any new insights into the variability and other properties of the central star. In the equator-on star η Cen, BRITE photometry and Heros echelle spectroscopy from the 1990s reveal an intricate clockwork of star-disk interactions. The mass transfer is modulated with the frequency difference of two NRP modes and an amplitude three times as large as the amplitude sum of the two NRP modes. This process feeds a high-amplitude circumstellar activity running with the incoherent and slightly lower so-called Štefl frequency. The mass-loss-modulation cycles are tightly coupled to variations in the value of the Štefl frequency and in its amplitude, albeit with strongly drifting phase differences. Conclusions: The observations are well described by the decomposition of the mass loss into a pulsation-related engine in the star and a viscosity-dominated engine in the circumstellar disk. Arguments are developed that large-scale gas-circulation flows occur at the interface. The propagation rates of these eddies manifest themselves as Štefl frequencies. Bursts in power spectra during mass-loss events can be understood as the noise inherent to
The AdS particle [rapid communication
NASA Astrophysics Data System (ADS)
Ghosh, Subir
2005-09-01
In this Letter we have considered a relativistic Nambu-Goto model for a particle in AdS metric. With appropriate gauge choice to fix the reparameterization invariance, we recover the previously discussed [S. Ghosh, P. Pal, Phys. Lett. B 618 (2005) 243, arxiv:hep-th/0502192] "exotic oscillator". The Snyder algebra and subsequently the κ-Minkowski spacetime are also derived. Lastly we comment on the impossibility of constructing a non-commutative spacetime in the context of open string where only a curved target space is introduced.
NASA Astrophysics Data System (ADS)
Figueiredo, Bruno; Cornet, Francois; Lamas, Luís; Muralha, José
2016-04-01
A case study is presented to show how stress field measurements may be used to assess the long-term rheological behaviour of an equivalent geo-material. The example concerns a granitic rock mass at the km3 scale, where an underground hydropower scheme including a new 10 km long power conduit and a powerhouse complex will be constructed. For design of the underground cavern and hydraulic pressure tunnel, several in situ stress measurements were carried out, using hydraulic borehole testing, overcoring and flat jack techniques. A first continuum mechanics model, with a homogenous material, was developed to integrate the several in situ test results and to assess the regional stress field. This model is based on elasticity and relaxation of the elastic properties measured through laboratory tests conducted on cores. Results of integration show that the long-term behavior of this granite rock mass differs markedly from the short-term behaviour as defined by laboratory tests. This suggests that the in-situ stress field depends mostly on the softer material that fills up the faults and hence results from the shear stress relaxation over a large number of pre-existing fractures and faults. A second continuum mechanics model, with consideration of two fault planes located nearby the hydraulic tests, was studied. This model is based on elasticity for the overall rock mass, with the elastic properties extracted from laboratory measurements, and visco-elasticity with small long-term shear strength for the two fault planes. Results show that the overall granite rock mass may be viewed as a combination of stiff elastic blocks separated by soft low strength material, leading to a fairly large scale homogeneous axisymmetrical stress field with vertical axis. Advantages and limitations of the two modelling approaches are discussed.
Gaudillière, Brice; Ganio, Edward A; Tingle, Martha; Lancero, Hope L; Fragiadakis, Gabriela K; Baca, Quentin J; Aghaeepour, Nima; Wong, Ronald J; Quaintance, Cele; El-Sayed, Yasser Y; Shaw, Gary M; Lewis, David B; Stevenson, David K; Nolan, Garry P; Angst, Martin S
2015-09-01
Single-cell technologies have immense potential to shed light on molecular and biological processes that drive human diseases. Mass cytometry (or Cytometry by Time Of Flight mass spectrometry, CyTOF) has already been employed in clinical studies to comprehensively survey patients' circulating immune system. As interest in the "bedside" application of mass cytometry is growing, the delineation of relevant methodological issues is called for. This report uses a newly generated dataset to discuss important methodological considerations when mass cytometry is implemented in a clinical study. Specifically, the use of whole blood samples versus peripheral blood mononuclear cells (PBMCs), design of mass-tagged antibody panels, technical and analytical implications of sample barcoding, and application of traditional and unsupervised approaches to analyze high-dimensional mass cytometry datasets are discussed. A mass cytometry assay was implemented in a cross-sectional study of 19 women with a history of term or preterm birth to determine whether immune traits in peripheral blood differentiate the two groups in the absence of pregnancy. Twenty-seven phenotypic and 11 intracellular markers were simultaneously analyzed in whole blood samples stimulated with lipopolysaccharide (LPS at 0, 0.1, 1, 10, and 100 ng mL(-1)) to examine dose-dependent signaling responses within the toll-like receptor 4 (TLR4) pathway. Complementary analyses, grounded in traditional or unsupervised gating strategies of immune cell subsets, indicated that the prpS6 and pMAPKAPK2 responses in classical monocytes are accentuated in women with a history of preterm birth (FDR<1%). The results suggest that women predisposed to preterm birth may be prone to mount an exacerbated TLR4 response during the course of pregnancy. This important hypothesis-generating finding points to the power of single-cell mass cytometry to detect biologically important differences in a relatively small patient cohort. PMID
Gaudillière, Brice; Ganio, Edward A.; Tingle, Martha; Lancero, Hope L.; Fragiadakis, Gabriela K.; Baca, Quentin J.; Aghaeepour, Nima; Wong, Ronald J.; Quaintance, Cele; El-Sayed, Yasser Y.; Shaw, Gary M.; Lewis, David B.; Stevenson, David K.; Nolan, Garry P.; Angst, Martin S.
2016-01-01
Single-cell technologies have immense potential to shed light on molecular and biological processes that drive human diseases. Mass cytometry (or Cytometry by Time Of Flight mass spectrometry, CyTOF) has already been employed in clinical studies to comprehensively survey patients’ circulating immune system. As interest in the “bedside” application of mass cytometry is growing, the delineation of relevant methodological issues is called for. This report uses a newly generated dataset to discuss important methodological considerations when mass cytometry is implemented in a clinical study. Specifically, the use of whole blood samples versus peripheral blood mononuclear cells (PBMCs), design of mass-tagged antibody panels, technical and analytical implications of sample barcoding, and application of traditional and unsupervised approaches to analyze high-dimensional mass cytometry datasets are discussed. A mass cytometry assay was implemented in a cross-sectional study of 19 women with a history of term or preterm birth to determine whether immune traits in peripheral blood differentiate the two groups in the absence of pregnancy. Twenty-seven phenotypic and 11 intracellular markers were simultaneously analyzed in whole blood samples stimulated with lipopolysaccharide (LPS at 0, 0.1, 1, 10, and 100 ng mL−1) to examine dose-dependent signaling responses within the toll-like receptor 4 (TLR4) pathway. Complementary analyses, grounded in traditional or unsupervised gating strategies of immune cell subsets, indicated that the prpS6 and pMAPKAPK2 responses in classical monocytes are accentuated in women with a history of preterm birth (FDR<1%). The results suggest that women predisposed to preterm birth may be prone to mount an exacerbated TLR4 response during the course of pregnancy. This important hypothesis-generating finding points to the power of single-cell mass cytometry to detect biologically important differences in a relatively small patient cohort. PMID
2010-01-01
Background A sedentary lifestyle and increased consumption of energy dense food have become more common in many parts of the world. The aim of this study was to study long term effects on body composition after a four week intervention with fast food based hyper-alimentation and limited physical activity in young normal weight subjects. Methods Eighteen subjects, mean age 26 (6.6) years, increased their energy intake with in average 70% and physical activity were not to exceed 5000 steps/day. Body composition was measured by Dual energy x-ray (DXA) at baseline, after the intervention and after 12 months. A matched control group was also included. ANOVA and Student's paired and unpaired t-test were used. Results During the intervention body weight increased with 6.4 (2.8) kg and DXA measurements showed increases of both fat free mass and fat mass. Six months after the intervention the subjects had lost most of the weight gain, - 4.7 (3.1) kg. Twelve months after the intervention body weight had increased with 1.5 (2.4) kg compared to baseline (p = 0.018). DXA measurements at 12 months showed unchanged fat free mass compared to baseline but higher fat mass, + 1.4 (1.9) kg (p = 0.01). After 2.5 years the increase of body weight was 3.1 (4.0) kg (p = 0.01) while there was no change in controls compared to baseline, + 0.1(2.5) kg (p = 0.88). Conclusion One year after a short term intervention with increased fast food based hyper-alimentation there was an increase of fat mass but unchanged fat free mass. As the change of fat mass was larger than expected from prospective epidemiological studies and as there was no increase of body weight in controls it raises the issue whether there is a long-term effect to increase fat mass of a short period of hyper-alimentation. PMID:20738843
Bite mass of cattle related to sward structure of four temperate grasses in short-term tests
Technology Transfer Automated Retrieval System (TEKTRAN)
Understanding how sward structure affects grazing behavior of ruminants requires knowledge of sward-animal interactions at the bite level. Therefore, the effect of sward structure of four grass species on bite mass of grazing dairy cows was evaluated. Holstein cows were offered micro-swards (79 cm x...
Measurements in urban Atlanta of transient aerosol events in which PM2.5 mass concentrations rapidly rise and fall over a period of 3-6 hr are reported. The data are based on new measurement techniques demonstrated at the U.S. Environmental Protection Agency (EPA) Atlanta Supe...
Probing crunching AdS cosmologies
NASA Astrophysics Data System (ADS)
Kumar, S. Prem; Vaganov, Vladislav
2016-02-01
Holographic gravity duals of deformations of CFTs formulated on de Sitter spacetime contain FRW geometries behind a horizon, with cosmological big crunch singularities. Using a specific analytically tractable solution within a particular single scalar truncation of {N}=8 supergravity on AdS4, we first probe such crunching cosmologies with spacelike radial geodesics that compute spatially antipodal correlators of large dimension boundary operators. At late times, the geodesics lie on the FRW slice of maximal expansion behind the horizon. The late time two-point functions factorise, and when transformed to the Einstein static universe, they exhibit a temporal non-analyticity determined by the maximal value of the scale factor ã max. Radial geodesics connecting antipodal points necessarily have de Sitter energy Ɛ ≲ ã max, while geodesics with Ɛ > ã max terminate at the crunch, the two categories of geodesics being separated by the maximal expansion slice. The spacelike crunch singularity is curved "outward" in the Penrose diagram for the deformed AdS backgrounds, and thus geodesic limits of the antipodal correlators do not directly probe the crunch. Beyond the geodesic limit, we point out that the scalar wave equation, analytically continued into the FRW patch, has a potential which is singular at the crunch along with complex WKB turning points in the vicinity of the FRW crunch. We then argue that the frequency space Green's function has a branch point determined by ã max which corresponds to the lowest quasinormal frequency.
NASA Astrophysics Data System (ADS)
Bena, Iosif; Heurtier, Lucien; Puhm, Andrea
2016-05-01
It was argued in [1] that the five-dimensional near-horizon extremal Kerr (NHEK) geometry can be embedded in String Theory as the infrared region of an infinite family of non-supersymmetric geometries that have D1, D5, momentum and KK monopole charges. We show that there exists a method to embed these geometries into asymptotically- {AdS}_3× {S}^3/{{Z}}_N solutions, and hence to obtain infinite families of flows whose infrared is NHEK. This indicates that the CFT dual to the NHEK geometry is the IR fixed point of a Renormalization Group flow from a known local UV CFT and opens the door to its explicit construction.
Shadows, currents, and AdS fields
Metsaev, R. R.
2008-11-15
Conformal totally symmetric arbitrary spin currents and shadow fields in flat space-time of dimension greater than or equal to four are studied. A gauge invariant formulation for such currents and shadow fields is developed. Gauge symmetries are realized by involving the Stueckelberg fields. A realization of global conformal boost symmetries is obtained. Gauge invariant differential constraints for currents and shadow fields are obtained. AdS/CFT correspondence for currents and shadow fields and the respective normalizable and non-normalizable solutions of massless totally symmetric arbitrary spin AdS fields are studied. The bulk fields are considered in a modified de Donder gauge that leads to decoupled equations of motion. We demonstrate that leftover on shell gauge symmetries of bulk fields correspond to gauge symmetries of boundary currents and shadow fields, while the modified de Donder gauge conditions for bulk fields correspond to differential constraints for boundary conformal currents and shadow fields. Breaking conformal symmetries, we find interrelations between the gauge invariant formulation of the currents and shadow fields, and the gauge invariant formulation of massive fields.
Bello-Medina, Paola C; Sánchez-Carrasco, Livia; González-Ornelas, Nadia R; Jeffery, Kathryn J; Ramírez-Amaya, Víctor
2013-08-01
Here we tested whether the well-known superiority of spaced training over massed training is equally evident in both object identity and object location recognition memory. We trained animals with objects placed in a variable or in a fixed location to produce a location-independent object identity memory or a location-dependent object representation. The training consisted of 5 trials that occurred either on one day (Massed) or over the course of 5 consecutive days (Spaced). The memory test was done in independent groups of animals either 24h or 7 days after the last training trial. In each test the animals were exposed to either a novel object, when trained with the objects in variable locations, or to a familiar object in a novel location, when trained with objects in fixed locations. The difference in time spent exploring the changed versus the familiar objects was used as a measure of recognition memory. For the object-identity-trained animals, spaced training produced clear evidence of recognition memory after both 24h and 7 days, but massed-training animals showed it only after 24h. In contrast, for the object-location-trained animals, recognition memory was evident after both retention intervals and with both training procedures. When objects were placed in variable locations for the two types of training and the test was done with a brand-new location, only the spaced-training animals showed recognition at 24h, but surprisingly, after 7 days, animals trained using both procedures were able to recognize the change, suggesting a post-training consolidation process. We suggest that the two training procedures trigger different neural mechanisms that may differ in the two segregated streams that process object information and that may consolidate differently. PMID:23644160
Galderisi, M; Celentano, A; Garofalo, M; Tammaro, P; Oliviero, M; Petrocelli, A; de Divitiis, O
1994-06-01
The aim of the present study was to evaluate the effect of dihydropyridine calcium antagonist isradipine on left ventricular (LV) structure and function in patients with essential hypertension. Cuff blood pressure and Doppler echocardiographic variables were assessed in 26 patients with mild to moderate hypertension (diastolic blood pressure range 95-110 mmHg) before and after 12 weeks of therapy with either isradipine 5 mg daily or enalapril 20 mg daily. The study was of double-blind, parallel design, with a placebo run-in period of 15 days. Three subjects withdrew from isradipine treatment because of flushing and 2 from enalapril treatment due to cough before completing the study. Both drugs significantly reduced cuff systolic and diastolic blood pressure (p < 0.001) without affecting heart rate. By virtue of the decrease in both septal wall (p < 0.01) and posterior wall thicknesses (p < 0.05), isradipine treatment produced a significant reduction in LV mass adjusted for height (p < 0.001) in comparison with placebo; also LV end-systolic dimension showed a slight decrease (p < 0.05). Enalapril induced a similar reduction in LV end-systolic dimension (p < 0.05) but the changes of wall thickness and LV mass did not reach statistical significance. In conclusion, our results indicate that isradipine treatment improves LV systolic function and causes a significant reduction in LV mass. This reduction is observed early in the course of antihypertensive treatment and is effective in both patients with and without LV hypertrophy. PMID:7921533
O'Hara, Blythe J; Phongsavan, Philayrath; Gebel, Klaus; Banovic, Debbie; Buffett, Kym M; Bauman, Adrian E
2014-11-01
The Get Healthy Information and Coaching Service® (GHS) was introduced in New South Wales in February 2009. It used mass reach media advertising and direct mail and/or proactive marketing to recruit participants. This article reports on the long-term impact of the campaign on GHS participation from July 2011 to June 2012. A stand-alone population survey collected awareness, knowledge, and behavioral variables before the first advertising phase, (n = 1,544, August-September 2010), during the advertising period (n = 1,500, February-March 2011; n = 1,500, June-July 2011; n = 1,500, February 2012), and after the advertising period (n = 1,500, June-July 2012). GHS usage data (n = 6,095) were collated during July 2011-June 2012. Unprompted and prompted awareness of GHS mass media significantly increased (0% to 8.0%, p < .001; and 14.1% to 43.9%, p < .001, respectively) as well as knowledge and perceived effectiveness of the GHS. Those from the lowest three quintiles of socioeconomic disadvantage and respondents who were overweight or obese were significantly more likely to report prompted campaign awareness. The majority (84.4%) of new GHS calls occurred when television advertising was present. Participants who cited mass media as their referral source were significantly more likely to enroll in the intensive coaching program. Mass media campaigns remain an effective method of promoting a telephone-based statewide lifestyle program. PMID:24662895
Tremaroli, Valentina; Karlsson, Fredrik; Werling, Malin; Ståhlman, Marcus; Kovatcheva-Datchary, Petia; Olbers, Torsten; Fändriks, Lars; le Roux, Carel W.; Nielsen, Jens; Bäckhed, Fredrik
2015-01-01
Summary Bariatric surgery is currently the most effective procedure for the treatment of obesity. Given the role of the gut microbiota in regulating host metabolism and adiposity, we investigated the long-term effects of bariatric surgery on the microbiome of patients randomized to Roux-en-Y gastric bypass or vertical banded gastroplasty and matched for weight and fat mass loss. The two surgical procedures induced similar and durable changes on the gut microbiome that were not dependent on body mass index and resulted in altered levels of fecal and circulating metabolites compared with obese controls. By colonizing germ-free mice with stools from the patients, we demonstrated that the surgically altered microbiota promoted reduced fat deposition in recipient mice. These mice also had a lower respiratory quotient, indicating decreased utilization of carbohydrates as fuel. Our results suggest that the gut microbiota may play a direct role in the reduction of adiposity observed after bariatric surgery. PMID:26244932
A Study of the Wide Main Sequence: The Long-Term Photometric Variability of Low Mass Stars
NASA Astrophysics Data System (ADS)
Pewett, Tiffany; Henry, Todd J.; Hosey, Altonio D.; Dieterich, Sergio; Jao, Wei-Chun; Winters, Jennifer G.; Riedel, Adric R.; RECONS Team
2016-01-01
The RECONS (REsearch Consortium On Nearby Stars, www.recons.org) team has carried out a long-term photometric variability study using the SMARTS 0.9m telescope at the Cerro Tololo Inter-American Observatory (CTIO). The program has obtained up to 15 years of observations in the V band for hundreds of M dwarf stars. This unique study has provided insight into how the ubiquitous M dwarfs change over decadal timescales, revealing their long-term magnetic cycles and how the presence or lack of such activity may affect their sizes and consequent luminosities, and thus their positions on the H-R Diagram.Using carefully vetted parallaxes and photometric colors, many measured by the RECONS team, we have created a highly accurate H-R Diagram of the nearest (within 25pc) stars using their V-K colors to represent temperatures and absolute V magnitudes as proxies for luminosities. We find that for M dwarfs, the main sequence widens significantly, by up to four magnitudes in MV, corresponding to a factor of almost 40 in optical flux. This spread implies a wide range of stellar radii for M dwarfs of the same temperature. Our study of long-term photometric variability indicates that there is a trend in cyclic activity that is highest for the most luminous red dwarfs and lowest for the rare, cool red subdwarfs. This provides valuable insight into the complex interplay of age, metallicity, and magnetic fields that molds the character of the red dwarfs.This effort has been supported by the NSF through grants AST-0908402, AST-1109445, and AST-1412026, STScI grant HST-GO-13724.001-A, and via observations made possible by the SMARTS Consortium.
Serraclara, A; Jódar, E; Sarabia, F; Hawkins, F
2001-01-01
The objective of this study was to assess bone mineral density (BMD) and bone markers in former hyperthyroid females after long-term euthyroidism (>4 yr) following (131)I therapy, as well as the potential influence of the timing of menopause. Twenty-six females ages 57 +/- 8 yr previously diagnosed with hyperthyroidism and treated with (131)I who were euthyroid for a minimum of the last 4 yr (10 +/- 5 yr) were studied. Eighteen patients (69%) were on levothyroxine (LT(4)) replacement therapy for 9 +/- 4 yr. BMD (g/cm(2) and Z-score) was measured by dual X-ray absorptiometry in the lumbar spine, femoral neck, and Ward's triangle. BMD (Z-score) was lower than the normal reference values for the Spanish population in all sites (lumbar spine: -0.65 +/- 1.13; femoral neck: -0.47 +/- 0.95; Ward's triangle: -0.37 +/- 0.88). No differences were found between BMD values according to the etiology of the hyperthyroidism or current LT(4) therapy. Current postmenopausal patients (n = 21) showed lower BMD than current premenopausal patients in the lumbar spine and femoral neck (p < 0.05). Those women who were postmenopausal at the time of the (131)I therapy (n = 15) also had lower lumbar spine BMD than premenopausal patients (p = 0.01), while no significant difference in BMD was seen according to the menopausal status when hyperthyroidism was diagnosed. Former hyperthyroid patients after long-term euthyroidism following (131)I therapy showed reduced BMD at the lumbar spine and proximal femur. Menopausal women showed a greater reduction in bone density. The menopausal status at the time of diagnosis did not seem to have long-term effects in bone density; nevertheless, an early therapeutic intervention in premenopause is suggested to reduce bone loss. PMID:11740067
An investigation of AdS2 backreaction and holography
NASA Astrophysics Data System (ADS)
Engelsöy, Julius; Mertens, Thomas G.; Verlinde, Herman
2016-07-01
We investigate a dilaton gravity model in AdS2 proposed by Almheiri and Polchinski [1] and develop a 1d effective description in terms of a dynamical boundary time with a Schwarzian derivative action. We show that the effective model is equivalent to a 1d version of Liouville theory, and investigate its dynamics and symmetries via a standard canonical framework. We include the coupling to arbitrary conformal matter and analyze the effective action in the presence of possible sources. We compute commutators of local operators at large time separation, and match the result with the time shift due to a gravitational shockwave interaction. We study a black hole evaporation process and comment on the role of entropy in this model.
Schmidt, Alexandre G. M. Portugal, L. Jesus, Anderson L. de
2015-01-15
We consider a particle with spin 1/2 with position-dependent mass moving in a plane. Considering separately Rashba and Dresselhaus spin-orbit interactions, we write down the Hamiltonian for this problem and solve it for Dirichlet boundary conditions. Our radial wavefunctions have two contributions: homogeneous ones which are written as Bessel functions of non-integer orders—that depend on angular momentum m—and particular solutions which are obtained after decoupling the non-homogeneous system. In this process, we find non-homogeneous Bessel equation, Laguerre, as well as biconfluent Heun equation. We also present the probability densities for m = 0, 1, 2 in an annular quantum well. Our results indicate that the background as well as the spin-orbit interaction naturally splits the spinor components.
On deformations of AdS n × S n supercosets
NASA Astrophysics Data System (ADS)
Hoare, B.; Roiban, R.; Tseytlin, A. A.
2014-06-01
We study the deformed AdS 5 × S 5 supercoset model of arXiv:1309.5850 which depends on one parameter κ and has classical quantum group symmetry. We confirm the conjecture that in the "maximal" deformation limit, κ → ∞, this model is T-dual to "flipped" double Wick rotation of the target space AdS 5 × S 5, i.e. dS 5 × H 5 space supported by an imaginary 5-form flux. In the imaginary deformation limit, κ → i, the corresponding target space metric is of a pp-wave type and thus the resulting light-cone gauge S-matrix becomes relativistically invariant. Omitting non-unitary contributions of imaginary WZ terms, we find that this tree-level S-matrix is equivalent to that of the generalized sine-Gordon model representing the Pohlmeyer reduction of the undeformed AdS 5 × S 5 superstring model. We also study in some detail similar deformations of the AdS 3 × S 3 and AdS 2 × S 2 supercosets. The bosonic part of the deformed AdS 3 × S 3 model happens to be equivalent to the symmetric case of the sum of the Fateev integrable deformation of the SL(2) and SU(2) principal chiral models, while in the AdS 2 × S 2 case the role of the Fateev model is played by the 2d "sausage" model. The κ = i limits are again directly related to the Pohlmeyer reductions of the corresponding AdS n × S n supercosets: (2,2) super sine-Gordon model and its complex sine-Gordon analog. We also discuss possible deformations of AdS 3 × S 3 with more than one parameter.
NASA Astrophysics Data System (ADS)
Collette, C.; Chesné, S.
2016-08-01
In this paper, the design of a hybrid mass damper (HMD) is proposed for the reduction of the resonant vibration amplitude of a multiple degree-of-freedom structure. HMD includes both passive and active elements. Combining these elements the system is fail-safe and its performances are comparable to usual purely active systems. The control law is a revisited direct velocity feedback. Two zeros are added to the controller to interact with the poles of the plant. The developed control law presents the particularity to be simple and hyperstable. The proposed HMD is compared to other classical control approaches for similar purpose in term of vibration attenuation, power consumption and stroke.
NASA Astrophysics Data System (ADS)
Wang, Z. B.; Hu, M.; Wu, Z. J.; Yue, D. L.; He, L. Y.; Huang, X. F.; Liu, X. G.; Wiedensohler, A.
2013-02-01
A series of long-term and temporary measurements were conducted to study the improvement of air quality in Beijing during Olympic Games period (8-24 August 2008). To evaluate actions taken to improve the air quality, comparisons of particle number and volume size distributions of August 2008 and 2004-2007 were performed. The total particle number and volume concentrations were 14 000 cm-3 and 37 μm3 cm-3 in August of 2008, respectively. These were reductions of 41% and 35% compared with the mean values of August 2004-2007. A cluster analysis on air mass history and source apportionment were performed, exploring reasons of the reduction of particle concentrations. Back trajectories were classified into five major clusters. Air mass from south direction are always associated with pollution events during the summertime of Beijing. In August 2008, the frequency of air mass arriving from south has been twice higher compared to the average of the previous years, these southerly air masses did however not result in elevated particle volume concentrations in Beijing. This result implied that the air mass history was not the key factor, explaining reduced particle number and volume concentrations during the Beijing 2008 Olympic Games. Four factors were found influencing particle concentrations using a Positive matrix factorization (PMF) model. They were identified to local and remote traffic emissions, combustion sources as well as secondary transformation. The reductions of the four sources were calculated to 47%, 44%, 43% and 30%, respectively. The significant reductions of particle number and volume concentrations may attribute to actions taken, focusing on primary emissions, especially related to the traffic and combustion sources.
NASA Astrophysics Data System (ADS)
Tasman, H.; Supali, T.; Supriatna, A. K.; Nuraini, N.; Soewono, E.
2015-03-01
In this paper we discuss a mathematical model for the transmission of lymphatic filariasis disease. The human population is divided into susceptible, latent, acute and chronic subpopulations. Treatment is carried out within the scheme of mass drug administration (MDA) by giving the diethylcarbamazine (DEC) and albendazole (ALB) to all individuals. In the model, we assume that the treatments have direct killing effect to microfilariae, increase of immune-mediated effect. The treated individuals are assumed to remain susceptible to the disease. This is due to the fact that the treatment is only partially effective against macrofilaria. Simulations of the model reveals that DEC-ALB treatment does give significant reduction of acute and chronic compartments at the end of the treatment period and slow down the growth after the treatment before eventually tend to the endemic state. It showed that repeated treatment during MDA is effective to decrease the transmission. This suggests that terminating MDA program after a long period of its application may still effective in controlling the disease.
Full halo coronal mass ejections: Do we need to correct the projection effect in terms of velocity?
NASA Astrophysics Data System (ADS)
Shen, C.; Wang, Y.; Pan, Z.; Zhang, M.; Ye, P.; Wang, S.
2013-12-01
The projection effect would distort our understanding of coronal mass ejections (CMEs) and influence the space weather forecasting. To evaluate the projection effect, the de-projected kinematic parameters of full halo CMEs (FHCMEs) listed in the CDAW CME catalog from 2007 March 1 to 2012 May 31 are studied by applying the Graduated Cylindrical Shell (GCS) model. It is revealed that, although these CMEs are all full halo in the view angle of SOHO, the de-projected parameters, including the propagation direction and angular width, could vary in a large range. Projection effect is a major but not only reason causing a CME being halo. By comparing the de-projected velocity with projected velocity of these CMEs, we find that not all of FHCMEs need to be corrected for their velocities; Almost all the FHCMEs which have obvious projection effect are originating within 45 of the Sun-Earth line and moving slower than 900 km/s in the plane-of-sky.
Full halo coronal mass ejections: Do we need to correct the projection effect in terms of velocity?
NASA Astrophysics Data System (ADS)
Shen, Chenglong; Wang, Yuming; Pan, Zonghao; Zhang, Min; Ye, Pinzhong; Wang, S.
2013-11-01
The projection effect is one of the biggest obstacles in learning the real properties of coronal mass ejections (CMEs) and forecasting their geoeffectiveness. To evaluate the projection effect, 86 full halo CMEs (FHCMEs) listed in the Coordinated Data Analysis Workshop CME catalog from 1 March 2007 to 31 May 2012 are investigated. By applying the Graduated Cylindrical Shell model, we obtain the deprojected values of the propagation velocity, direction, and angular width of these FHCMEs and compare them with the projected values measured in the plane-of-sky. Although these CMEs look full halo in the view angle of SOHO, it is found that their propagation directions and angular widths could vary in a large range, implying projection effect is a major reason causing a CME being halo, but not the only one. Furthermore, the comparison of the deprojected and projected velocities reveals that most FHCMEs originating within 45° of the Sun-Earth line with a projected speed slower than 900 km s-1 suffer from large projection effect, while the FHCMEs originating far from the vicinity of solar disk center or moving faster than 900 km s-1have small projection effect. Thus, for the latter class of FHCMEs, it is not necessary to correct the measured velocities.
From the generalized uncertainty relations on fuzzy AdS 2 to the Poincaré geometry
NASA Astrophysics Data System (ADS)
Fakhri, H.; Hashemi, A.; Lotfizadeh, M.
2012-03-01
The positive and discrete unitary irreps of SU(1,1) are used to construct fuzzy (Euclidean) AdS 2. Two different types of uncertainty relation involving the Weyl-Heisenberg and a weaker type are studied. It is shown that there are no generalized coherent states which simultaneously minimize the Weyl-Heisenberg uncertainty relations among three non-commuting embedding coordinates of the fuzzy AdS 2. However, generalized squeezed states that simultaneously satisfy the three weaker uncertainty relations do exist, and reproduce some properties of the classical AdS 2. Up to a common scaling factor in terms of the irrep label, the expectation values of the non-commuting coordinates over such states are described in the same manner as the classical AdS 2, in terms of the Poincaré coordinates. The expectation values on the fuzzy AdS 2 tend to their corresponding values in the commutative limit.
CFT adapted gauge invariant formulation of arbitrary spin fields in AdS and modified de Donder gauge
NASA Astrophysics Data System (ADS)
Metsaev, R. R.
2009-01-01
Using Poincaré parametrization of AdS space, we study totally symmetric arbitrary spin massless fields in AdS space of dimension greater than or equal to four. CFT adapted gauge invariant formulation for such fields is developed. Gauge symmetries are realized similarly to the ones of Stueckelberg formulation of massive fields. We demonstrate that the curvature and radial coordinate contributions to the gauge transformation and Lagrangian of the AdS fields can be expressed in terms of ladder operators. Realization of the global AdS symmetries in the conformal algebra basis is obtained. Modified de Donder gauge leading to simple gauge fixed Lagrangian is found. The modified de Donder gauge leads to decoupled equations of motion which can easily be solved in terms of the Bessel function. Interrelations between our approach to the massless AdS fields and the Stueckelberg approach to massive fields in flat space are discussed.
NASA Technical Reports Server (NTRS)
Clauson, J.; Heuser, J.
1981-01-01
The Applications Data Service (ADS) is a system based on an electronic data communications network which will permit scientists to share the data stored in data bases at universities and at government and private installations. It is designed to allow users to readily locate and access high quality, timely data from multiple sources. The ADS Pilot program objectives and the current plans for accomplishing those objectives are described.
Wang, Shao‐Ming; Fan, Jin‐Hu; Jia, Meng‐Meng; Yang, Zhao; Zhang, Yu‐Qing; Taylor, Philip R.
2016-01-01
Abstract Background Studies based on Western populations have found that body mass index (BMI) is positively related to the risk of esophageal adenocarcinoma but inversely associated with esophageal squamous cell carcinoma (ESCC). Little reliable evidence exists of an association between BMI and ESCCin China, where ESCC incidence is high but BMI is low. Methods We evaluated the BMI‐ESCC association in a population‐based prospective study of 29 446 Chinese aged 40–69 with 27 years of follow‐up. China‐specific BMI cut‐offs (underweight < 18.5, healthy ≥ 18.5 to <24, overweight ≥ 24 to <28, and obese ≥ 28) and quartile categories were used to define BMI subgroups. Adjusted hazard ratios (HRs) and confidence intervals (CIs) for death from ESCC by BMI subgroups were calculated using Cox proportional hazards models. Results During a median follow‐up duration of 21.2 years (555 439 person‐years), 2436 ESCC deaths were identified. BMI was protective for death from ESCC with an HR of 0.97 (95% CI 0.95–0.99) for each unit increase in BMI. Relative to healthy weight, HRs for BMI were 1.21 (95% CI 1.02–1.43) for the underweight group and 0.87 (95% CI 0.78–0.98) for the overweight. Categorical quartile analyses found people with BMIs in the Q3 and Q4 groups had 16% and 13% reductions in the risk of ESCC, respectively. Gender‐specific analyses found that clear effects were evident in women only. Conclusions Higher BMI was associated with a reduced risk of ESCC in aChinese population. PMID:27385979
Metastability in bubbling AdS space
NASA Astrophysics Data System (ADS)
Massai, Stefano; Pasini, Giulio; Puhm, Andrea
2015-02-01
We study the dynamics of probe M5 branes with dissolved M2 charge in bubbling geometries with SO(4) × SO(4) symmetry. These solutions were constructed by Bena-Warner and Lin-Lunin-Maldacena and correspond to the vacua of the maximally supersymmetric mass-deformed M2 brane theory. We find that supersymmetric probe M2 branes polarize into M5 brane shells whose backreaction creates an additional bubble in the geometry. We explicitly check that the supersymmetric polarization potential agrees with the one found within the Polchinski-Strassler approximation. The main result of this paper is that probe M2 branes whose orientation is opposite to the background flux can polarize into metastable M5 brane shells. These decay to a supersymmetric configuration via brane-flux annihilation. Our findings suggest the existence of metastable states in the mass-deformed M2 brane theory.
Bjornvad, C R; Elnif, J; Sangild, P T
2004-11-01
For many mammalian species short-term fasting is associated with intestinal atrophy and decreased digestive capacity. Under natural conditions, strictly carnivorous animals often experience prey scarcity during winter, and they may therefore be particularly well adapted to short-term food deprivation. To examine how the carnivorous gastrointestinal tract is affected by fasting, small-intestinal structure, brush-border enzyme activities and hepatic structure and function were examined in fed mink (controls) and mink that had been fasted for 1-10 days. During the first 1-2 days of fasting, intestinal mass decreased more rapidly than total body mass and villus heights were reduced 25-40%. In contrast, tissue-specific activity of the brush-border enzymes sucrase, maltase, lactase, aminopeptidase A and dipeptidylpeptidase IV increased 0.5- to 1.5-fold at this time, but returned to prefasting levels after 6 days of fasting. After 6-10 days of fasting there was a marked increase in the activity of hepatic enzymes and accumulation of intra-hepatic lipid vacuoles. Thus, mink may be a useful model for studying fasting-induced intestinal atrophy and adaptation as well as mechanisms involved in accumulation of intra-hepatic lipids following food deprivation in strictly carnivorous domestic mammals, such as cats and ferrets. PMID:15503054
Anunciado-Koza, Rea P; Manuel, Justin; Koza, Robert A
2016-01-01
Heterogeneity of obesity within a population of inbred mice fed an obesogenic high-fat diet (HFD) is associated with changes of gene expression in white adipose tissue (WAT). One gene in particular with large variations among mice, mesoderm-specific transcript (Mest), has been shown to be highly inducible after being fed a short-term HFD, and its expression in WAT before HFD feeding is predictive for susceptibility to the development of obesity. To gain further insight into the association of Mest with rapid changes in body composition, 96 individually housed C57BL/6J mice were fed an HFD for only 2 weeks, resulting in a 12-fold and 90-fold variation in Mest mRNA in visceral epididymal and subcutaneous inguinal WAT, respectively. WAT Mest mRNA was positively associated with interindividual variation of fat mass. Surprisingly, there was only a slight association of WAT Mest with food intake when normalized by body weight or lean mass. In addition, WAT Mest expression coincided highly with the expression of the transcription factor Kruppel-like factor 14 (Klf14), an imprinted gene that regulates lipid metabolism in WAT. Our data suggest that KLF14 transcriptional activity may partially mediate, or act in concert with, MEST as part of an epigenetic mechanism that promotes fat mass accumulation in mice fed an obesogenic diet. PMID:26647164
Rhee, G.Y.; Sokol, R.C.; Bush, B. . Wadsworth Center for Labs. and Research); Bethoney, C.M. . School of Public Health, New York State Dept. of Health)
1993-10-01
Reductive dechlorination of PCBs by Hudson River sediment microorganisms was investigated using individual congeners, 2,3,4,2[prime],4[prime],5[prime]-, 2,4,5,2[prime],4[prime],5[prime]-, 2,3,4,5,6-, 2,4,2[prime],4[prime]-, and 3,4,3[prime],4[prime]-chlorobiphenyls (CBPs) in long-term studies lasting 15 to 20 months. The dechlorination of 2,3,4,2[prime],4[prime],5[prime]-CBP yielded 2,4,5,2[prime],4[prime]-, 2,4,2[prime],4[prime]-, 2,4,2[prime],5[prime]-, and 2,4,2[prime],5[prime]-, and 2,4,2[prime]-CBPs; notably absent was 2,2[prime]-CBP. Yet, the total molar concentration of all congeners decreased with time and at 15 months accounted for only 25% of the initial concentration of the parent compound. 2,3,4,5,6-CBP produced 2,3,5,6-, 2,4,6-, and 2,6-CBPs. At 15 months the sum of all congeners accounted for only about 50% of the initial amount of the parent congener. On the other hand, 2,4,5,2[prime],4[prime],5[prime]-CBP yielded six daughter products, including 2,2[prime]-CBP, and did not show any decrease in total molar concentration even at 20 months. 2,4,2[prime],4[prime]-CBP did not show any change at 15 months. These results indicate that anaerobic PCB biotransformation may include mechanisms other than dechlorination and that the mechanisms are congener dependent. Biphenyl was detected with 3,4,3[prime],4[prime]-CBP, indicating complete dechlorination; however, it accounted for <10% of the total molar loss. [sup 14]C-labeled tracer of this congener showed that all radioactivity was in the hexane fraction, suggesting that transformation products were hydrophobic.
2014-01-01
Background Temporary employment, a precarious form of employment, is recognized as social determinant of poor health. However, evidence supporting precarious employment as a risk factor for health is mainly obtained from subjective data. Studies using objective clinical measurement data in the assessment of health status are limited. This study compared body mass index (BMI), lipid and glucose metabolism, and health-related lifestyle factors between permanent workers and fixed-term workers employed in the manufacturing industry. Methods Data of 1,701 male manufacturing industry workers <50 years old in Japan were collected and analyzed. Anthropometric data were BMI, calculated using measured height and weight of study participants, and blood pressure. For lipid metabolism, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglyceride levels were determined. For glucose metabolism, fasting plasma glucose and hemoglobin A1c (HbA1c) levels were measured. Multiple regression analysis adjusted for age and lifestyle factors was performed. Results BMI was significantly higher in permanent workers (22.9 kg/m2) compared with fixed-term workers (22.4 kg/m2). The leaner population (BMI < 18.5) was greater among fixed-term workers (8.3%) compared with permanent workers (4.0%), whereas the overweight population (BMI ≥ 25.0) was greater among permanent workers (21.4%) compared with fixed-term workers (18.1%). Although fixed-term workers tended not to be overweight, regression analysis adjusted for age and lifestyle factors suggested that fixed-term employment was significantly associated with higher blood pressure (systolic β = 2.120, diastolic β = 2.793), triglyceride (β = 11.147), fasting blood glucose (β = 2.218), and HbA1c (β = 0.107) compared with permanent workers (all p < 0.01). Conclusions Fixed-term workers showed more health risks, such as poorer blood pressure and lipid and glucose metabolism
Tiberio, Stacey S.; Kerr, David C. R.; Capaldi, Deborah M.; Pears, Katherine C.; Kim, Hyoun K.; Nowicka, Paulina
2014-01-01
monitoring effect on children's BMI z score slopes remained significant once adjusting for children's media time, and sports and recreational activity. Conclusions This study suggests that parental behaviors related to children's media consumption may have long-term impacts on children's BMI in middle childhood. The results underscore the importance of targeting parental media monitoring in efforts to prevent childhood obesity. PMID:24638968
Zachos, Ioannis; Dimitropoulos, Konstantinos; Karatzas, Anastasios; Samarinas, Michael; Petsiti, Argiro; Tassoudis, Vassilios; Tzortzis, Vassilios
2016-01-01
Objectives: Surgical management of small renal masses can be challenging in frail patients and thus modalities such as radiofrequency ablation (RFA) have emerged as valid alternative options. The aim of the current study was to present mid-term oncological and functional results on a series of patients with cT1a renal cell carcinomas (RCCs) who were unfit for surgery and underwent RFA using ultrasound guidance under local anesthesia. Methods: Data from patients fulfilling the study selection criteria were retrospectively collected. RENAL nephrometry score was used for tumor description. Parametric tests were used for data analysis and survival curves were estimated using the Kaplan–Meier method. Results: Overall, 32 patients (mean±standard deviation age, 72.4 ± 7.6 years) with biopsy-proven RCCs (tumor size, 23.75 ± 10.44 mm and RENAL score, 5.28 ± 1.33) underwent 32 RFA sessions. Twenty-seven patients (84.4%) had low complexity masses and five patients had masses of intermediate complexity (15.6%) according to RENAL score categorization. Over a follow-up period of 22.1 ± 13.7 months, one case of primary treatment failure was recognized (primary technical success 97.0%), and overall, three patients were diagnosed with residual disease (primary technique effectiveness 90.6%). No major complications occurred during the postprocedure 90-day follow up, while no difference was found in serum creatinine and estimated glomerular filtration rate pre and post procedure. Patients with intermediate-complexity renal lesions had shorter time to recurrence in comparison to low-complexity masses (p = 0.002). All patients were alive at the time of study data analysis without diagnosed metastases. Conclusions: Percutaneous RFA of small RCCs using ultrasound-based guidance under local anesthesia can be an effective alternative method for managing patients who are unfit for surgery.
Sartorio, A; Lafortuna, C L; Silvestri, G; Narici, M V
2003-02-01
The study investigated the effect of a short-term (3-week) body mass reduction program, combining energy-restricted diet, nutritional education, psychological counselling and aerobic exercise training (DEP-AT) on maximal oxygen consumption (VO2max) and anaerobic alactic performance evaluated with different techniques in obese patients (grade II and III). Fifty-three (14 males, 39 females) obese subjects [average +/- SD body mass index (BMI): 41.6 +/- 4.2 kg/m2] were tested before and after the DEP-AT program characterised by a daily conditioning protocol of aerobic exercise on cycloergometer, treadmill and armergometer for a total duration of 35 min at an intensity corresponding to 50% of individual VO2max during the first week of the program and at 60% in the following 2 weeks. VO2max was determined with the cycloergometric indirect method. Short-term alactic anaerobic performance was evaluated with: a) jumping test (5 consecutive jumps with maximal effort, Bosco technique), b) short sprint running test (8m), and c) stair climbing test (modified Margaria test). The DEP-AT program induced a significant weight loss (-4.57 +/- 1.26%, p < 0.001) and a significant VO2max increase (14.1 +/- 20.5%, p < 0.001). After the DEP-AT program, lower limb alactic anaerobic power output, calculated on a per kg body mass basis, increased significantly both in jumping and in stair climbing (20.1 +/- 24.8%, p < 0.001 and 13.5 +/- 19.75%, p < 0.001, respectively), as well as average horizontal velocity during short sprinting (7.2 +/- 17.6%, p < 0.01). Power output was a major determinant of the motor performance, being significantly correlated with: a) vertical displacement of the centre of gravity (R2 = 0.884, p < 0.001) in jumping test, b) vertical velocity (R2 = 0.348, p < 0.001) in stair climbing test, and c) horizontal velocity (R2 = 0.394, p < 0.001) in short running test. In conclusion, short-term DEP-AT program induces significant improvements in both aerobic capabilities and
Realizing "value-added" metrology
NASA Astrophysics Data System (ADS)
Bunday, Benjamin; Lipscomb, Pete; Allgair, John; Patel, Dilip; Caldwell, Mark; Solecky, Eric; Archie, Chas; Morningstar, Jennifer; Rice, Bryan J.; Singh, Bhanwar; Cain, Jason; Emami, Iraj; Banke, Bill, Jr.; Herrera, Alfredo; Ukraintsev, Vladamir; Schlessinger, Jerry; Ritchison, Jeff
2007-03-01
The conventional premise that metrology is a "non-value-added necessary evil" is a misleading and dangerous assertion, which must be viewed as obsolete thinking. Many metrology applications are key enablers to traditionally labeled "value-added" processing steps in lithography and etch, such that they can be considered integral parts of the processes. Various key trends in modern, state-of-the-art processing such as optical proximity correction (OPC), design for manufacturability (DFM), and advanced process control (APC) are based, at their hearts, on the assumption of fine-tuned metrology, in terms of uncertainty and accuracy. These trends are vehicles where metrology thus has large opportunities to create value through the engineering of tight and targetable process distributions. Such distributions make possible predictability in speed-sorts and in other parameters, which results in high-end product. Additionally, significant reliance has also been placed on defect metrology to predict, improve, and reduce yield variability. The necessary quality metrology is strongly influenced by not only the choice of equipment, but also the quality application of these tools in a production environment. The ultimate value added by metrology is a result of quality tools run by a quality metrology team using quality practices. This paper will explore the relationships among present and future trends and challenges in metrology, including equipment, key applications, and metrology deployment in the manufacturing flow. Of key importance are metrology personnel, with their expertise, practices, and metrics in achieving and maintaining the required level of metrology performance, including where precision, matching, and accuracy fit into these considerations. The value of metrology will be demonstrated to have shifted to "key enabler of large revenues," debunking the out-of-date premise that metrology is "non-value-added." Examples used will be from critical dimension (CD
Berkes, Balázs B; Jozwiuk, Anna; Vračar, Miloš; Sommer, Heino; Brezesinski, Torsten; Janek, Jürgen
2015-06-16
We describe the benefits of an online continuous flow differential electrochemical mass spectrometry (DEMS) method that allows for realistic battery cycling conditions. We provide a detailed description on the buildup and the role of the different components in the system. Special emphasis is given on the cell design. The retention time and response characteristics of the system are tested with the electrolysis of Li2O2. Finally, we show a practical application in which a Li-ion battery is examined. The value of long-term DEMS measurements for the proper evaluation of electrolyte decomposition is demonstrated by an experiment where a Li(1+x)Ni(0.5)Mn(0.3)Co(0.2)O2 (NMC 532)/graphite cell is cycled over 20 charge/discharge cycles. PMID:25965095
Farhat, Alicia Elena; Sharma, Shreela; Abrams, Stephanie H; Wong, William W; Barlow, Sarah E
2016-03-01
Long-term effects of Kamp K'aana, a 2-week residential weight management camp, on body mass index (BMI) measures were evaluated on 71 of 108 (66%) obese youth 10 to 14 years of age. Measures were obtained at 11-month study follow-up (n = 38) or extracted from medical record (n = 33). Compared with baseline, BMI increased (P < 0.001), but both BMI percentile and BMI z score decreased (98.7 ± 1.0 to 97.3 ± 6.7 and 2.34 ± 0.30 to 2.23 ± 0.34, P < 0.001). A decrease in BMI z score of ≥0.2 units was seen in 27% of the participants (P < 0.001). The short program has sustained effect. PMID:26327212
Innovations Without Added Costs
ERIC Educational Resources Information Center
Cereghino, Edward
1974-01-01
There is no question that we are in a tight money market, and schools are among the first institutions to feel the squeeze. Therefore, when a plan is offered that provides for innovations without added costs, its something worth noting. (Editor)
ERIC Educational Resources Information Center
Richards, Andrew
2015-01-01
Two quantitative measures of school performance are currently used, the average points score (APS) at Key Stage 2 and value-added (VA), which measures the rate of academic improvement between Key Stage 1 and 2. These figures are used by parents and the Office for Standards in Education to make judgements and comparisons. However, simple…
NASA Astrophysics Data System (ADS)
Turco, M.; Milelli, M.
2009-09-01
To the authors' knowledge there are relatively few studies that try to answer this topic: "Are humans able to add value to computer-generated forecasts and warnings ?". Moreover, the answers are not always positive. In particular some postprocessing method is competitive or superior to human forecast (see for instance Baars et al., 2005, Charba et al., 2002, Doswell C., 2003, Roebber et al., 1996, Sanders F., 1986). Within the alert system of ARPA Piemonte it is possible to study in an objective manner if the human forecaster is able to add value with respect to computer-generated forecasts. Every day the meteorology group of the Centro Funzionale of Regione Piemonte produces the HQPF (Human QPF) in terms of an areal average for each of the 13 regional warning areas, which have been created according to meteo-hydrological criteria. This allows the decision makers to produce an evaluation of the expected effects by comparing these HQPFs with predefined rainfall thresholds. Another important ingredient in this study is the very dense non-GTS network of rain gauges available that makes possible a high resolution verification. In this context the most useful verification approach is the measure of the QPF and HQPF skills by first converting precipitation expressed as continuous amounts into ‘‘exceedance'' categories (yes-no statements indicating whether precipitation equals or exceeds selected thresholds) and then computing the performances for each threshold. In particular in this work we compare the performances of the latest three years of QPF derived from two meteorological models COSMO-I7 (the Italian version of the COSMO Model, a mesoscale model developed in the framework of the COSMO Consortium) and IFS (the ECMWF global model) with the HQPF. In this analysis it is possible to introduce the hypothesis test developed by Hamill (1999), in which a confidence interval is calculated with the bootstrap method in order to establish the real difference between the
NASA Astrophysics Data System (ADS)
Wang, Z. B.; Hu, M.; Wu, Z. J.; Yue, D. L.; He, L. Y.; Huang, X. F.; Liu, X. G.; Wiedensohler, A.
2013-10-01
A series of long-term and temporary measurements were conducted to study the improvement of air quality in Beijing during the Olympic Games period (8-24 August 2008). To evaluate actions taken to improve the air quality, comparisons of particle number and volume size distributions of August 2008 and 2004-2007 were performed. The total particle number and volume concentrations were 14 000 cm-3 and 37 μm-3 cm-3 in August of 2008, respectively. These were reductions of 41% and 35% compared with mean values of August 2004-2007. A cluster analysis on air mass history and source apportionment were performed, exploring reasons for the reduction of particle concentrations. Back trajectories were classified into five major clusters. Air masses from the south direction are always associated with pollution events during the summertime in Beijing. In August 2008, the frequency of air mass arriving from the south was 1.3 times higher compared to the average of the previous years, which however did not result in elevated particle volume concentrations in Beijing. Therefore, the reduced particle number and volume concentrations during the 2008 Beijing Olympic Games cannot be only explained by meteorological conditions. Four factors were found influencing particle concentrations using a positive matrix factorization (PMF) model. They were identified as local and remote traffic emissions, combustion sources as well as secondary transformation. The reductions of the four sources were calculated to 47%, 44%, 43% and 30%, respectively. The significant reductions of particle number and volume concentrations may attribute to actions taken, focusing on primary emissions, especially related to the traffic and combustion sources.
Determining Positions and Desired Applicant Characteristics in Sports Job Ads
ERIC Educational Resources Information Center
Atali, Levent
2015-01-01
The purpose of this study is to determine the diversity of positions occurring in sports job ads and reveal the characteristics requested from applicants for each position. This study examined 103 sports-related job ads obtained from four human resources websites. Using content analysis, job ads were examined in terms of job titles, and the…
Black hole microstates in AdS4 from supersymmetric localization
NASA Astrophysics Data System (ADS)
Benini, Francesco; Hristov, Kiril; Zaffaroni, Alberto
2016-05-01
This paper addresses a long standing problem, the counting of the microstates of supersymmetric asymptotically AdS black holes in terms of a holographically dual field theory. We focus on a class of asymptotically AdS4 static black holes preserving two real supercharges which are dual to a topologically twisted deformation of the ABJM theory. We evaluate in the large N limit the topologically twisted index of the ABJM theory and we show that it correctly reproduces the entropy of the AdS4 black holes. An extremization of the index with respect to a set of chemical potentials is required. We interpret it as the selection of the exact R-symmetry of the superconformal quantum mechanics describing the horizon of the black hole.
QCD Condensates and Holographic Wilson Loops for Asymptotically AdS Spaces
Quevedo, R. Carcasses; Goity, Jose L.; Trinchero, Roberto C.
2014-02-01
The minimization of the Nambu-Goto (NG) action for a surface whose contour defines a circular Wilson loop of radius a placed at a finite value of the coordinate orthogonal to the border is considered. This is done for asymptotically AdS spaces. The condensates of dimension n = 2, 4, 6, 8, and 10 are calculated in terms of the coefficients in the expansion in powers of the radius a of the on-shell subtracted NG action for small a->0. The subtraction employed is such that it presents no conflict with conformal invariance in the AdS case and need not introduce an additional infrared scale for the case of confining geometries. It is shown that the UV value of the gluon condensates is universal in the sense that it only depends on the first coefficients of the difference with the AdS case.
Solutions in bosonic string field theory and higher spin algebras in AdS
NASA Astrophysics Data System (ADS)
Polyakov, Dimitri
2015-11-01
We find a class of analytic solutions in open bosonic string field theory, parametrized by the chiral copy of higher spin algebra in AdS3. The solutions are expressed in terms of the generating function for the products of Bell polynomials in derivatives of bosonic space-time coordinates Xm(z ) of the open string, the form of which is determined in this work. The products of these polynomials form a natural operator algebra realizations of w∞ (area-preserving diffeomorphisms), enveloping algebra of SU(2) and higher spin algebra in AdS3. The class of string field theory solutions found can, in turn, be interpreted as the "enveloping of enveloping," or the enveloping of AdS3 higher spin algebra. We also discuss the extensions of this class of solutions to superstring theory and their relations to higher spin algebras in higher space-time dimensions.
Li, Longxue; Wang, Maoqing; Chen, Shuhong; Zhao, Wei; Zhao, Yue; Wang, Xu; Zhang, Yang
2016-03-01
The study was to assess the long-term toxic effects of acetochlor on rats. Two different doses (42.96 and 107.4 mg/kg body weight/day) of acetochlor were administered to Wistar rats through their food for over 24 weeks. Rat urine samples were collected at two time-points for the measurements of the metabonomics profiles with ultra-performance liquid chromatography-mass spectrometry (UPLC-MSMS). The results of clinical chemistry and histopathology suggested that long-term use of acetochlor in rats caused liver and kidney damage, and dysfunction of antioxidant system. The urinary metabonomics analysis indicated that the high and low-dose exposure of acetochlor could cause alterations of these metabonomics in urine in the rat. Significant changes of the levels of hippuric acid (0.403-fold decrease), citric acid (0.430-fold decrease), pantothenic acid (0.486-fold decrease), uracil (0.419-fold decrease), β-Alanine (0.325-fold decrease), nonanedioic acid (0.445-fold decrease), L-tyrosine (0.410-fold decrease), D-glucuronic acid (8.389-fold increase) and 2-ethyl-6-methyl-N-methyl-2-chloro-acetanilide in urine were observed. In addition, it may interfere with the fatty acid synthesis, the pyrimidine degradation and pantothenate biosynthesis. The level of 2-ethyl-6-methyl-N-methyl-2-chloro-acetanilide is detected in all treated groups which is not found in the control groups, indicating which can be used as an early, sensitive marker of acetochlor exposure in rat. This study illustrates the important utility of metabonomics approaches to understand the toxicity of long-term exposure of acetochlor. PMID:26969444
Ali, Mir; Ruiz, Frenny; Saint-Victor, Carlos; Vazquez-Poritz, Justin F.
2009-08-15
We consider the behavior of open strings on anti-de Sitter wormholes in Gauss-Bonnet theory, which are the Gauss-Bonnet gravity duals of a pair of field theories. A string with both endpoints on the same side of the wormhole describes two charges within the same field theory, which exhibit Coulomb interaction for small separation. On the other hand, a string extending through the wormhole describes two charges which live in different field theories, and they exhibit a springlike confining potential. A transition occurs when there is a pair of charges present within each field theory: for small separation each pair of charges exhibits Coulomb interaction, while for large separation the charges in the different field theories pair up and exhibit confinement. Two steadily-moving charges in different field theories can occupy the same location provided that their speed is less than a critical speed, which also plays the role of a subluminal speed limit. However, for some wormhole backgrounds, charges moving at the critical speed cannot occupy the same location and energy is transferred from the leading charge to the lagging one. We also show that strings on anti-de Sitter wormholes in supergravity theories without higher-derivative curvature terms can exhibit these properties as well.
Two Virasoro symmetries in stringy warped AdS3
NASA Astrophysics Data System (ADS)
Compère, Geoffrey; Guica, Monica; Rodriguez, Maria J.
2014-12-01
We study three-dimensional consistent truncations of type IIB supergravity which admit warped AdS3 solutions. These theories contain subsectors that have no bulk dynamics. We show that the symplectic form for these theories, when restricted to the non-dynamical subsectors, equals the symplectic form for pure Einstein gravity in AdS3. Consequently, for each consistent choice of boundary conditions in AdS3, we can define a consistent phase space in warped AdS3 with identical conserved charges. This way, we easily obtain a Virasoro × Virasoro asymptotic symmetry algebra in warped AdS3; two different types of Virasoro × Kač-Moody symmetries are also consistent alternatives.
Two Visual-Spectroscopic Binary Orbits - ADS7780 and ADS11060
NASA Astrophysics Data System (ADS)
Heintz, W. D.
1982-08-01
The combination of micrometer and radial-velocity observations is applied to two orbits of high eccentricities and inclinations. All results on the G1 V triple star ADS 11060 (including the subsystem studied by Batten et al.) show good consistency and precision. Substantial uncertainty remains in the component masses of ADS 7780 = β LMi (G9 III) which could be also a triple star.
Generalized massive gravity in AdS{sub 3} spacetime
Liu Yan; Sun Yawen
2009-06-15
In this note we investigate the generalized massive gravity in asymptotically AdS{sub 3} spacetime by combining the two mass terms of topological massive gravity and new massive gravity theory. We study the linearized excitations around the AdS{sub 3} background and find that at a specific value of a certain combination of the two mass parameters (chiral line), one of the massive graviton solutions becomes the left-moving massless mode. It is shown that the theory is chiral at this line under Brown-Henneaux boundary condition. Because of this degeneration of the gravitons the new log solution which has a logarithmic asymptotic behavior is also a solution to this gravity theory at the chiral line. The log boundary condition which was proposed to accommodate this log solution is proved to be consistent at this chiral line. The resulting theory is no longer chiral except at a special point on the chiral line, where another new solution with log-square asymptotic behavior exists. At this special point, we prove that a new kind of boundary condition called log-square boundary condition, which accommodates this new solution, can be consistent.
ERIC Educational Resources Information Center
King, Kenneth P.
2007-01-01
The inertial balance is one device that can help students to quantify the quality of inertia--a body's resistance to a change in movement--in more generally understood terms of mass. In this hands-on activity, students use the inertial balance to develop a more quantitative idea of what mass means in an inertial sense. The activity also helps…
NASA Astrophysics Data System (ADS)
Antony Chen, L.-W.; Watson, John G.; Chow, Judith C.; DuBois, David W.; Herschberger, Lisa
2010-12-01
The Minnesota Particulate Matter 2.5 (PM 2.5) Source Apportionment Study was undertaken to explore the utility of PM 2.5 mass, element, ion, and carbon measurements from long-term speciation networks for pollution source attribution. Ambient monitoring data at eight sites across the state were retrieved from the archives of the Interagency Monitoring of Protected Visual Environments (IMPROVE) and the Speciation Trends Network (STN; part of the Chemical Speciation Network [CSN]) and analyzed by an Effective Variance - Chemical Mass Balance (EV-CMB) receptor model with region-specific geological source profiles developed in this study. PM 2.5 was apportioned into contributions of fugitive soil dust, calcium-rich dust, taconite (low grade iron ore) dust, road salt, motor vehicle exhaust, biomass burning, coal-fired utility, and secondary aerosol. Secondary sulfate and nitrate contributed strongly (49-71% of PM 2.5) across all sites and was dominant (≥60%) at IMPROVE sites. Vehicle exhausts accounted for 20-70% of the primary PM 2.5 contribution, largely exceeding the proportion in the primary PM 2.5 emission inventory. The diesel exhaust contribution was separable from the gasoline engine exhaust contribution at the STN sites. Higher detection limits for several marker elements in the STN resulted in non-detectable coal-fired boiler contributions which were detected in the IMPROVE data. Despite the different measured variables, analytical methods, and detection limits, EV-CMB results from a nearby IMPROVE-STN non-urban/urban sites showed similar contributions from regional sources - including fugitive dust and secondary aerosol. Seasonal variations of source contributions were examined and extreme PM 2.5 episodes were explained by both local and regional pollution events.
Cohen, Sophie; Innes, Steve; Geelen, Sibyl P. M.; Wells, Jonathan C. K.; Smit, Colette; Wolfs, Tom F. W.; van Eck-Smit, Berthe L. F.; Kuijpers, Taco W.; Reiss, Peter; Scherpbier, Henriette J.
2015-01-01
Objective Longitudinal studies objectively evaluating changes in regional fat distribution of HIV-infected children assessed by whole body dual energy X-ray absorptiometry (DEXA) are scarce, whilst this long-term effect of HIV and antiretroviral therapy (cART) is an important issue in infected children in need for lifelong treatment. Methods We assessed regional fat distribution over time, measured with sequential DEXA-scans in HIV-infected children on cART in cohorts from South Africa (SA) and the Netherlands (NL), and in healthy controls (SA). Limb and trunk fat Z-scores were calculated with the lambda-mu-sigma (LMS) method. Multivariable linear regression models with mixed effects were used to investigate the effect of cART compounds on body fat distribution over time. Results In total, 218 children underwent 445 DEXA assessments with a median follow-up of 3.5 years. Fat mass in all limbs was decreased in HIV-infected children compared to controls (arm fat Z-score: coefficient -0.4813; P = 0.006, leg fat Z-score: coefficient -0.4345; P = 0.013). In the HIV-infected group, stavudine treatment was associated with lower subcutaneous fat mass (arm fat Z-score: coefficient -0.5838; P = 0.001), with an additional cumulative exposure effect (arm fat Z-score: coefficient -0.0867; P = 0.003). Conclusions Our study shows that subcutaneous fat loss is still prevalent in HIV-infected children on cART, and is strongly associated with cumulative stavudine exposure. These results underline the need for early detection of subcutaneous fat loss and alternative treatment options for HIV-infected children globally. PMID:26148119
Evans, Nick
2016-09-12
Essential facts Leading Change, Adding Value is NHS England's new nursing and midwifery framework. It is designed to build on Compassion in Practice (CiP), which was published 3 years ago and set out the 6Cs: compassion, care, commitment, courage, competence and communication. CiP established the values at the heart of nursing and midwifery, while the new framework sets out how staff can help transform the health and care sectors to meet the aims of the NHS England's Five Year Forward View. PMID:27615573
Rotating (A)dS black holes in bigravity
NASA Astrophysics Data System (ADS)
Ayón-Beato, Eloy; Higuita-Borja, Daniel; Méndez-Zavaleta, Julio A.
2016-01-01
In this paper we explore the advantage of using the Kerr-Schild Ansatz in the search for analytic configurations to bigravity. It turns out that it plays a crucial role by providing means to straightforwardly calculate the square root matrix encoding the interaction terms between both gravities. In this spirit, we rederive the Babichev-Fabbri family of asymptotically flat rotating black holes with the aid of an emerging circularity theorem. Taking into account that the interaction terms contain by default two cosmological constants, we repeat our approach starting from the more natural seeds for the Kerr-Schild Ansatz in this context: the (A)dS spacetimes. As a result, we show that a couple of Kerr-(A)dS black holes constitute an exact solution to ghost-free bigravity. Similar to the asymptotically flat case, these black holes share the same angular momentum and (A)dS radius, but their masses are not constrained to be equal.
Farshid, G; Downey, P; Gill, Pg; Pieterse, S
2008-04-01
Discrete masses are commonly detected during mammographic screening and most such lesions are benign. For lesions without pathognomonically benign imaging features that are still regarded likely to be non-malignant (Tabar grade 3) reliable biopsy results would be a clinically useful alternative to mammographic surveillance. Appropriate institutional guidelines for ethical research were followed. Between Jan 1996--Dec 2005 grade 3B discrete masses detected in the setting of a large, population based, breast cancer screening programme are included. Patient demographics, fine needle aspiration biopsy (FNAB), core and surgical biopsy results are tabulated. The final pathology of excised lesions was obtained. Information regarding interval cancers was obtained from the State Cancer Registry records and also through long term follow-up of clients in subsequent rounds of screening. A total of 1183 lesions, mean diameter of 13.3 mm (+/-8.3 mm) and mean client age of 55.1 years (+/-8.8 years) are included. After diagnostic work up, 98 lesions (8.3%) were malignant, 1083 were non-malignant and a final histologic diagnosis was not established in two lesions. In the 27 months after assessment, no interval cancers were attributable to these lesions and during a mean follow up of 54.5 months, available in 84.9% of eligible women, only one cancer has developed in the same quadrant as the original lesion, although the two processes are believed to be unrelated. FNAB performed in 1149 cases was definitive in 80.5% cases (882 benign, 43 malignant) with a negative predictive value (NPV) of 99.8% (880 of 882) and a positive predictive value (PPV) of 95.2% (40 of 42, both intraductal papillomas). Core biopsy was performed in 178 lesions, mostly for indefinite cytology. Core biopsy was definitive in 79.8% cases (57% benign 22% malignant) with a PPV of 100% and NPV of 99.0%. In experienced hands FNAB is an accurate first line diagnostic modality for the assessment of 3B screen
Su, Nan; Fei, Qi; Wang, Bingqiang; Li, Dong; Li, Jinjun; Meng, Hai; Yang, Yong; Guo, Ai
2016-01-01
Objectives The purpose of the present study was to explore and analyze the long-term outcomes and factors that affect the prognosis of expansive open-door laminoplasty with lateral mass screw fusion in treatment of cervical spondylotic myelopathy (CSM). Methods We retrospectively reviewed 49 patients with multilevel CSM who had undergone expansive open-door laminoplasty with lateral mass screws fixation and fusion in our hospital between February 2008 and February 2012. The average follow-up period was 4.6 years. The clinical data of patients, including age, sex, operation records, pre- and postoperation Japanese Orthopedic Association (JOA) scores, cervical spine canal stenosis, and cervical curvature, were collected. Increased signal intensity (ISI) on T2-weighted magnetic resonance imaging and ossification of the posterior longitudinal ligament were also observed. Paired t-test was used to analyze the treatment effectiveness and recovery of neuronal function. The prognostic factors were analyzed with multivariable linear regression model. Results Forty-nine patients with CSM with a mean age of 59.44 years were enrolled in this study. The average of preoperative JOA score was 9.14±2.25, and postoperative JOA score was 15.31±1.73. There was significant difference between the pre- and postoperative JOA scores. The clinical improvement rate was 80.27%. On follow-up, five patients had complaints of neck and shoulder pain, but no evidence of C5 nerve palsy was found. Developmental cervical spine canal stenosis was present in all patients before surgery. Before surgery, ISI was observed in eight patients, while ossification of the posterior longitudinal ligament was found in 12 patients. The average of preoperative cervical curvature was 21.27°±8.37° and postoperative cervical curvature was 20.09°±1.29°, and there was no significant difference between the pre- and postoperative cervical curvatures. Multivariable linear regression analysis results showed that
Sun, Xiaowei; Xu, Wei; Zeng, Yan; Hou, Yurong; Guo, Lin; Zhao, Xiujuan; Sun, Changhao
2014-02-01
The purpose of this study was to investigate the toxic effect of long-term and low-level exposure to phorate using a metabonomics approach based on ultra-performance liquid chromatography-mass spectrometry (UPLC-MS). Male Wistar rats were given phorate daily in drinking water at low doses of 0.05, 0.15 or 0.45 mg kg⁻¹ body weight (BW) for 24 weeks consecutively. Rats in the control group were given an equivalent volume of drinking water. Compared with the control group, serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), total bilirubin (TBIL), urea nitrogen (BUN) and creatinine (CR) were increased in the middle- and high-dose groups whereas albumin (ALB) and cholinesterase (CHE) were decreased. Urine metabonomics profiles were analyzed by UPLC-MS. Compared with the control group, 12 metabolites were significantly changed in phorate-treated groups. In the negative mode, metabolite intensities of uric acid, suberic acid and citric acid were significantly decreased in the middle- and high-dose groups, whereas indoxyl sulfic acid (indican) and cholic acid were increased. In the positive mode, uric acid, creatinine, kynurenic acid and xanthurenic acid were significantly decreased in the middle- and high-dose groups, but 7-methylguanine (N⁷G) was increased. In both negative and positive modes, diethylthiophosphate (DETP) was significantly increased, which was considered as a biomarker of exposure to phorate. In conclusion, long-term and low-level exposure to phorate can cause disturbances in energy-related metabolism, liver and kidney function, the antioxidant system, and DNA damage. Moreover, more information can be provided on the evaluation of toxicity of phorate using metabonomics combined with clinical chemistry. PMID:23280859
Cutting Budget Corners While Adding Value.
ERIC Educational Resources Information Center
Veile, Craig N.; Carpenter, Mark J.
2000-01-01
Discusses how one school district saved money while adding long- term value to its capital improvement project. Planning issues involving square footage requirements, quality of material to be used, and heating and cooling system selection are discussed as are concepts to increase student learning capacity for the same construction dollars. (GR)
NASA Astrophysics Data System (ADS)
Fakhri, Hossein; Imaanpur, Ali
2003-03-01
In this article we construct the chirality and Dirac operators on noncommutative AdS2. We also derive the discrete spectrum of the Dirac operator which is important in the study of the spectral triple associated to AdS2. It is shown that the degeneracy of the spectrum present in the commutative AdS2 is lifted in the noncommutative case. The way we construct the chirality operator is suggestive of how to introduce the projector operators of the corresponding projective modules on this space.