126 research outputs found
Daily fluctuations in occupation with and worry about COVID-19
In the first week after the first COVID-19 patient was reported in the Netherlands, we conducted a pre-registered momentary assessment study (7 surveys per day, 50 participants, 7 days) to study the dynamic relationship between individuals' occupation with and worries about COVID-19 in daily life, and the moderating role of neuroticism in this relationship. At the group level, higher scores on occupation and worry co-occurred, and occupation predicted worry 1 h later, but not vice versa. There were substantial individual differences in the magnitudes and directions of the effects. For instance, occupation with COVID-19 was related to increases in worry for some but decreases in worry for others. Neuroticism did not predict any of these individual differences in the links between worry and occupation. This study suggests that it is important to go beyond group-level analyses and to account for individual differences in responses to COVID-19
Invasion Genetics of the Western Flower Thrips in China: Evidence for Genetic Bottleneck, Hybridization and Bridgehead Effect
The western flower thrips, Frankliniella occidentalis (Pergande), is an invasive species and the most economically important pest within the insect order Thysanoptera. F. occidentalis, which is endemic to North America, was initially detected in Kunming in southwestern China in 2000 and since then it has rapidly invaded several other localities in China where it has greatly damaged greenhouse vegetables and ornamental crops. Controlling this invasive pest in China requires an understanding of its genetic makeup and migration patterns. Using the mitochondrial COI gene and 10 microsatellites, eight of which were newly isolated and are highly polymorphic, we investigated the genetic structure and the routes of range expansion of 14 F. occidentalis populations in China. Both the mitochondrial and microsatellite data revealed that the genetic diversity of F. occidentalis of the Chinese populations is lower than that in its native range. Two previously reported cryptic species (or ecotypes) were found in the study. The divergence in the mitochondrial COI of two Chinese cryptic species (or ecotypes) was about 3.3% but they cannot be distinguished by nuclear markers. Hybridization might produce such substantial mitochondrial-nuclear discordance. Furthermore, we found low genetic differentiation (global FST = 0.043, P<0.001) among all the populations and strong evidence for gene flow, especially from the three southwestern populations (Baoshan, Dali and Kunming) to the other Chinese populations. The directional gene flow was further supported by the higher genetic diversity of these three southwestern populations. Thus, quarantine and management of F. occidentalis should focus on preventing it from spreading from the putative source populations to other parts of China
Gut Microbiota, Probiotics and Diabetes
Diabetes is a condition of multifactorial origin, involving several molecular mechanisms related to the intestinal
microbiota for its development. In type 2 diabetes, receptor activation and recognition by microorganisms from
the intestinal lumen may trigger inflammatory responses, inducing the phosphorylation of serine residues in insulin
receptor substrate-1, reducing insulin sensitivity. In type 1 diabetes, the lowered expression of adhesion proteins
within the intestinal epithelium favours a greater immune response that may result in destruction of pancreatic
β cells by CD8+ T-lymphocytes, and increased expression of interleukin-17, related to autoimmunity. Research in
animal models and humans has hypothesized whether the administration of probiotics may improve the prognosis
of diabetes through modulation of gut microbiota. We have shown in this review that a large body of evidence
suggests probiotics reduce the inflammatory response and oxidative stress, as well as increase the expression of
adhesion proteins within the intestinal epithelium, reducing intestinal permeability. Such effects increase insulin sensitivity and reduce autoimmune response. However, further investigations are required to clarify whether the administration of probiotics can be efficiently used for the prevention and management of diabetes
Multiphysics and Thermodynamic Formulations for Equilibrium and Non-equilibrium Interactions: Non-linear Finite Elements Applied to Multi-coupled Active Materials
[EN] Combining several theories this paper presents a general multiphysics framework applied to the study of coupled and active materials, considering mechanical, electric, magnetic and thermal fields. The framework is based on thermodynamic equilibrium and non-equilibrium interactions, both linked by a two-temperature model. The multi-coupled governing equations are obtained from energy, momentum and entropy balances; the total energy is the sum of thermal, mechanical and electromagnetic parts. The momentum balance considers mechanical plus electromagnetic balances; for the latter the Abraham rep- resentation using the Maxwell stress tensor is formulated. This tensor is manipulated to automatically fulfill the angular momentum balance. The entropy balance is for- mulated using the classical Gibbs equation for equilibrium interactions and non-equilibrium thermodynamics. For the non-linear finite element formulations, this equation requires the transformation of thermoelectric coupling and conductivities into tensorial form. The two-way thermoe- lastic Biot term introduces damping: thermomechanical, pyromagnetic and pyroelectric converse electromagnetic dynamic interactions. Ponderomotrix and electromagnetic forces are also considered. The governing equations are converted into a variational formulation with the resulting four-field, multi-coupled formalism implemented and val- idated with two custom-made finite elements in the research code FEAP. Standard first-order isoparametric eight-node elements with seven degrees of freedom (dof) per node (three displacements, voltage and magnetic scalar potentials plus two temperatures) are used. Non-linearities and dynamics are solved with Newton-Raphson and New- mark-b algorithms, respectively. Results of thermoelectric, thermoelastic, thermomagnetic, piezoelectric, piezomag- netic, pyroelectric, pyromagnetic and galvanomagnetic interactions are presented, including non-linear depen- dency on temperature and some second-order interactions.This research was partially supported by grants CSD2008-00037 Canfranc Underground Physics, Polytechnic University of Valencia under programs PAID 02-11-1828 and 05-10-2674. The first author used the grant Generalitat Valenciana BEST/2014/232 for the completion of this work.Pérez-Aparicio, JL.; Palma, R.; Taylor, R. (2016). Multiphysics and Thermodynamic Formulations for Equilibrium and Non-equilibrium Interactions: Non-linear Finite Elements Applied to Multi-coupled Active Materials. Archives of Computational Methods in Engineering. 23:535-583. https://doi.org/10.1007/s11831-015-9149-9S53558323Abraham M (1910) Sull’elettrodinamica di Minkowski. Rend Circ Mat 30:33–46Allik H, Hughes TJR (1970) Finite elment method for piezoelectric vibration. Int J Numer Methods Eng 2:151–157Antonova EE, Looman DC (2005) Finite elements for thermoelectric device analysis in ANSYS. In: International conference on thermoelectricsAtulasimha J, Flatau AB (2011) A review of magnetostrictive iron–gallium alloys. Smart Mater Struct 20:1–15Ballato A (1995) Piezoelectricity: old effect, new thrusts. IEEE Trans Ultrason Ferroelectr Freq Control 42(5):916–926Baoyuan S, Jiantong W, Jun Z, Min Q (2003) A new model describing physical effects in crystals: the diagrammatic and analytic methods for macro-phenomenological theory. J Mater Process Technol 139:444–447Bargmann S, Steinmann P (2005) Finite element approaches to non-classical heat conduction in solids. Comput Model Eng Sci 9(2):133–150Bargmann S, Steinmann P (2006) Theoretical and computational aspects of non-classical thermoelasticity. Comput Methods Appl Mech Eng 196:516–527Bargmann S, Steinmann P (2008) Modeling and simulation of first and second sound in solids. Int J Solids Struct 45:6067–6073Barnett SM (2010) Resolution of the Abraham–Minkowski dilemma. Phys Rev Lett 104:070401Benbouzid MH, Meunier G, Meunier G (1995) Dynamic modelling of giant magnetostriction in Terfenol-D rods by the finite element method. IEEE Trans Magn 31(3):1821–1824Benbouzid MH, Reyne G, Meunier G (1993) Nonlinear finite element modelling of giant magnetostriction. IEEE Trans Magn 29(6):2467–2469Benbouzid MH, Reyne G, Meunier G (1995) Finite elment modelling of magnetostrictive devices: investigations for the design of the magnetic circuit. IEEE Trans Magn 31(3):1813–1816Besbes M, Ren Z, Razek A (1996) Finite element analysis of magneto-mechanical coupled phenomena in magnetostrictive materials. IEEE Trans Magn 32(3):1058–1061Biot MA (1956) Thermoelasticity and irreversible thermodynamics. J Appl Phys 27(3):240–253Bisio G, Cartesegna M, Rubatto G (2001) Thermodynamic analysis of elastic systems. Energy Convers Manag 42:799–812Blun SL (1974) Materials for radiation detection. National Academy of Sciences, WashingtonBonet J, Wood RD (1997) Nonlinear continuum mechanics for finite element analysis. Cambridge University Press, CambridgeBorovik-Romanov AS (1960) Piezomagnetism in the antiferromagnetic fluorides of cobalt and manganese. Sov Phys 11:786Bowyer P (2005) The momentum of light in media: the Abraham–Minkowski controversy. http://bit.ly/1M7wyATBrauer JR, Ruehl JJ, MacNeal BE, Hirtenfelder F (1995) Finite element analysis of Hall effect and magnetoresistance. IEEE Trans Electron Devices 42(2):328–333Bustamante R, Dorfmann A, Ogden RW (2009) On electric body forces and Maxwell stresses in nonlinearly electroelastic solids. Int J Eng Sci 47:1131–1141Callen HB (1948) The application of Onsager’s reciprocal relations to thermoelectric, thermomagnetic, and galvanomagnetic effects. Phys Rev 73(11):1349–1358Callen HB (1985) Thermodynamics and an introduction to thermostatistics. Wiley, New YorkCarter JP, Booker JR (1989) Finite element analysis of coupled thermoelasticity. Comput Struct 31(1):73–80Cattaneo C (1938) Sulla conduzione del calore. Atti Semin Mat Fis Univ Modena 3:83–1013Chaplik AV (2000) Some exact solutions for the classical Hall effect in an inhomogeneous magnetic field. JETP Lett 72:503Chen PJ, Gurtin ME (1968) On a theory of heat conduction involving two temperatures. J Z Angew Math Phys ZAMP 19(4):614–627Chu LJ, Haus HA, Penfield P (1966) The force density in polarizable and magnetizable fluids. In: Proceedings of the IEEEClin Th, Turenne S, Vasilevskiy D, Masut RA (2009) Numerical simulation of the thermomechanical behavior of extruded bismuth telluride alloy module. J Electron Mater 38(7):994–1001Coleman BD (1964) Thermodynamics of materials with memory. Arch Ration Mech Anal 17:1–46de Groot SR (1961) Non-equilibrium themodynamics of systems in an electromagnetic field. J Nucl Energy C Plasma Phys 2:188–194de Groot SR, Mazur P (1984) Non-equilibrium thermodynamics. Dover, MineolaDebye P (1913) On the theory of anomalous dispersion in the region of long-wave electromagnetic radiation. Verh dtsch phys Ges 15:777–793del Castillo LF, García-Colín LS (1986) Thermodynamic basis for dielectric relaxation in complex materials. Phys Rev B 33(7):4944–4951Delves RT (1964) Figure of merit for Ettingshausen cooling. Br J Appl Phys 15:105–106Dorf RC (1997) The electrical engineering handbook. CRC Press, UKEarle R, Richards JFC (1956) Theophrastus: on stones. Ohio State University, ColumbusEbling D, Jaegle M, Bartel M, Jacquot A, Bottner H (2009) Multiphysics simulation of thermoelectric systems for comparison with experimental device performance. J Electron Mater 38(7):1456–1461El-Karamany AS, Ezzat MA (2011) On the two-temperature Green–Naghdi thermoelasticity theories. J Therm Stress 34:1207–1226Eringen AC (1980) Mechanics of continua. Robert E Krieger, MalabarEringen AC, Maugin GA (1990) Electrodynamics of continua I. Springer, New YorkErsoy Y (1984) A new nonlinear constitutive theory for conducting magnetothermoelastic solids. Int J Eng Sci 22(6):683–705Ersoy Y (1986) A new nonlinear constitutive theory of electric and heat conductions for magnetoelastothermo-electrical anisotropic solids. Int J Eng Sci 24(6):867–882Ferrari A, Mittica A (2013) Thermodynamic formulation of the constitutive equations for solids and fluids. Energy Convers Manag 66:77–86Galushko D, Ermakov N, Karpovski M, Palevski A, Ishay JS, Bergman DJ (2005) Electrical, thermoelectric and thermophysical properties of hornet cuticle. Semicond Sci Technol 20:286–289Gao JL, Du QG, Zhang XD, Jiang XQ (2011) Thermal stress analysis and structure parameter selection for a Bi2Te3-based thermoelectric module. J Electron Mater 40(5):884–888Gaudenzi P, Bathe KJ (1995) An iterative finite element procedure for the analysis of piezoelectric continua. J Intell Mater Syst Struct 6:266–273Gavela D, Pérez-Aparicio JL (1998) Peltier pellet analysis with a coupled, non-linear 3D finite element model. In: 4th European workshop on thermoelectricsGoudreau GL, Taylor RL (1972) Evaluation of numerical integration methods in elastodynamics. Comput Methods Appl Mech Eng 2:69–97Griffiths DJ (1999) Introduction to electrodynamics. Prentice-Hall Inc, Upper Saddle RiverGros L, Reyne G, Body C, Meunier G (1998) Strong coupling magneto mechanical methods applied to model heavy magnetostrictive actuators. IEEE Trans Magn 34(5):3150–3153Gurtin ME, Williams WO (1966) On the Clausius–Duhem inequality. J Z Angew Math Phys ZAMP 17(5):626–633Hamader VM, Patil TA, Chovan SH (1987) Free vibration response of two-dimensional magneto-electro-elastic laminated plates. Build Mater Sci 9:249–253Hausler C, Milde G, Balke H, Bahr HA, Gerlach G (2001) 3-D modeling of pyroelectric sensor arrays part I: multiphysics finite-element simulation. IEEE Sens J 8(12):2080–2087He Y (2004) Heat capacity, thermal conductivity and thermal expansion of barium titanate-based ceramics. Thermochimica 419:135–141Hernández-Lemus E, Orgaz E (2002) Hysteresis in nonequilibrium steady states: the role of dissipative couplings. Rev Mex Fís 48:38–45Hinds EA (2009) Momentum exchange between light and a single atom: Abraham or Minkowski? Phys Rev Lett 102:050403Hirsinger L, Billardon R (1995) Magneto-elastic finite element analysis including magnetic forces and magnetostriction effects. IEEE Trans Magn 31(3):1877–1880Huang MJ, Chou PK, Lin MC (2008) An investigation of the thermal stresses induced in a thin-film thermoelectric cooler. J Therm Stress 31:438–454IEEE Standards Board (1988) IEEE standard on piezoelectricity. ANSI/IEEE Std 176-1987. doi: 10.1109/IEEESTD.1988.79638IEEE Standards Board (1991) IEEE standard on magnetostrictive materials: piezomagnetic nomenclature. IEEE Std 319-1990. doi: 10.1109/IEEESTD.1991.101048Ioffe Institute (2013) INSb—indium antimonide. Ioffe Institute. www.ioffe.rssi.ru/SVA/NSM/Semicond/InSb/index.htmlJackson JD (1962) Classical electrodynamics. Wiley, New YorkJaegle M (2008) Multiphysics simulation of thermoelectric systems—modeling of Peltier—cooling and thermoelectric generation. In: Proceedings of the COMSOLJaegle M, Bartel M, Ebling D, Jacquot A, Bottner H (2008) Multiphysics simulation of thermoelectric systems. In: European conference on thermoelectrics ECT2008Jiménez JL, Campos I (1996) Advanced electromagnetism: foundations, theory and applications, chapter The balance equations of energy and momentum in classical electrodynamics. World Scientific Publishing, SingaporeJohnstone S (2008) Is there potential for use of the Hall effect in analytical science? Analyst 133:293–296Jou D, Lebon G (1996) Extended irreversible thermodynamics. Springer, BerlinKaltenbacher M, Kaltenbacher B, Hegewald T, Lerch R (2010) Finite element formulation for ferroelectric hysteresis of piezoelectric materials. J Intell Mater Syst Struct 21:773–785Kaltenbacher M, Meiler M, Ertl M (2009) Physical modeling and numerical computation of magnetostriction. Int J Comput Math Electr Electron Eng 28(4):819–832Kamlah M, Bohle U (2001) Finite element analysis of piezoceramic components taking into account ferroelectric hysteresis behavior. Int J Solids Struct 38:605–633Kannan KS, Dasgupta A (1997) A nonlinear Galerkin finite-element theory for modeling magnetostrictive smart structures. Smart Mater Struct 6:341–350Kiang J, Tong L (2010) Nonlinear magneto-mechanical finite element analysis of Ni–Mn–Ga single crystals. Smart Mater Struct 19:1–17Kinsler P, Favaro A, McCall MW (2009) Four Poynting theorems. Eur J Phys 30:983–993Klinckel S, Linnemann K (2008) A phenomenological constitutive model for magnetostrictive materials and ferroelectric ceramics. Proc Appl Math Mech 8:10507–10508Kosmeier D (2013) Hornets: Gentle Giants! Wikipedia: the free encyclopedia. www.hornissenschutz.de/hornets.htmLahmer T (2008) Forward and inverse problems in piezoelectricity. PhD thesis, Universität Erlangen-NürnbergLandau LD, Lifshitz EM (1982) Mechanics. Butterworth-Heinemann, OxfordLandau LD, Lifshitz EM (1984) Electrodynamics of continuous media. Pergamon Press, OxfordLandis CM (2002) A new finite-element formulation for electromechanical boundary value problems. Int J Numer Methods Eng 55:613–628Díaz Lantada A (2011) Handbook of active materials for medical devices: advances and applications. CRC Press, Boca RatonLebon G, Jou D, Casas-Vázquez J (2008) Understanding non-equilibrium thermodynamics. Springer, BerlinLinnemann K, Klinkel S (2006) A constitutive model for magnetostrictive materials—theory and finite element implementation. Proc Appl Math Mech 6:393–394Linnemann K, Klinkel S, Wagner W (2009) A constitutive model for magnetostrictive and piezoelectric materials. Int J Solids Struct 46:1149–1166Llebot JE, Jou D, Casas-Vázquez J (1983) A thermodynamic approach to heat and electric conduction in solids. Physica 121(A):552–562Lu X, Hanagud V (2004) Extended irreversible thermodynamics modeling for self-heating and dissipation in piezoelectric ceramics. IEEE Trans Ultrason Ferroelectr Freq Control 51(12):1582–1592Lubarda VA (2004) On thermodynamic potentials in linear thermoelasticity. Int J Solids Struct 41:7377–7398Mansuripur M (2012) Trouble with the lorentz law of force: incompatibility with special relativity and momentum conservation. Phys Rev Lett 108:193901Maruszewski B, Lebon G (1986) An extended irreversible thermodynamic description of electrothermoelastic semiconductors. Int J Eng Sci 24(4):583–593McMeeking RM, Landis CM (2005) Electrostatic forces and stored energy for deformable dielectric materials. J Appl Mech 72:581–590McMeeking RM, Landis CM, Jimenez MA (2007) A principle of virtual work for combined electrostatic and mechanical loading of materials. Int J Non Linear Mech 42:831–838MELCOR (2000) Thermoelectric handbook. Melcor, a unit of Laird Technologies. http://www.lairdtech.comMinkowski H (1908) Nachr. ges. wiss. Gottingen 53Naranjo B, Gimzewski JK, Putterman S (2005) Observation of nuclear fusion driven by a pyroelectric crystal. Nature 28(434):1115–1117Nédélec JC (1980) Mixed finite elements in R 3 . Numer Math 35:314–345Nettleton RE, Sobolev SL (1995) Applications of extended thermodynamics to chemical, rheological, and transport processes: a special survey part I. approaches and scalar rate processes. J Non-Equilib Thermodyn 20:205–229Nettleton RE, Sobolev SL (1995) Applications of extended thermodynamics to chemical, rheological, and transport processes: a special survey part II. vector transport processes, shear relaxation and rheology. J Non-Equilib Thermodyn 20:297–331Nettleton RE, Sobolev SL (1996) Applications of extended thermodynamics to chemical, rheological, and transport processes: a special survey part III. wave phenomena. J Non-Equilib Thermodyn 21:1–16Newmark N (1959) A method of computation for structural dynamics. ASCE J Eng Mech 85:67–94Newnham RE (2005) Properties of materials: anisotropy, symmetry, structure. Oxford University Press, OxfordNour AE, Abd-Alla N, Maugin GA (1990) Nonlinear equations for thermoelastic magnetizable conductors. Int J Eng Sci 27(7):589–603Nowacki A (1962) International series of monographs in aeronautics and astronautics. Pergamon Press, OxfordOkumura H, Hasegawa Y, Nakamura H, Yamaguchi S (1999) A computational model of thermoelectric and thermomagnetic semiconductors. In: 18th international conference on thermoelectricsOkumura H, Yamaguchi S, Nakamura H, Ikeda K, Sawada K (1998) Numerical computation of thermoelectric and thermomagnetic effects. In: 17th international conference on thermoelectricsOliver X, Agelet C (2000) Continuum mechanics for engineers. Edicions UPC, Barcelona. http://hdl.handle.net/2099.3/36197Shankar K, Kondaiah P, Ganesan N (2013) Pyroelectric and pyromagnetic effects on multiphase magneto-electro-elastic cylindrical shells for axisymmetric temperature. Smart Mater Struct 22(2):025007Palma R, Pérez-Aparicio JL, Bravo R (2013) Study of hysteretic thermoelectric behavior in photovoltaic materials using the finite element method, extended thermodynamics and inverse problems. Energy Convers Manag 65:557–563Palma R, Pérez-Aparicio JL, Taylor RL (2012) Non-linear finite element formulation applied to thermoelectric materials under hyperbolic heat conduction model. Comput Method Appl Mech Eng 213–216:93–103Palma R, Rus G, Gallego R (2009) Probabilistic inverse problem and system uncertainties for damage detection in piezoelectrics. Mech Mater 41:1000–1016Pérez-Aparicio JL, Gavela D (1998) 3D, non-linear coupled, finite element model of thermoelectricity. In: 4th European workshop on thermoelectricsPérez-Aparicio JL, Palma R, Taylor RL (2012) Finite element analysis and material sensitivity of Peltier thermoelectric cells coolers. Int J Heat Mass Transf 55:1363–1374Pérez-Aparicio JL, Sosa H (2004) A continuum three-dimensional, fully coupled, dynamic, non-linear finite element formulation for magnetostrictive materials. Smart Mater Struct 13:493–502Perez-Aparicio JL, Sosa H, Palma R (2007) Numerical investigations of field-defect interactions in piezoelectric ceramics. Int J Solids Struct 44:4892–4908Pérez-Aparicio JL, Taylor RL, Gavela D (2007) Finite element analysis of nonlinear fully coupled thermoelectric materials. Comput Mech 40:35–45Qi H, Fang D, Yao Z (1997) FEM analysis of electro-mechanical coupling effect of piezoelectric materials. Comput Mater Sci 8:283–290Pérez-Aparicio JL, Palma R, Abouali-Sánchez S (2014) Complete finite element method analysis of galvanomagnetic and thermomagnetic effects. Appl Therm Eng (submitted)Perez-Aparicio JL, Palma R, Moreno-Navarro P (2014) Elasto-thermoelectric non-linear, fully coupled, and dynamic finite element analysis of pulsed thermoelectrics. Appl Therm Eng (submitted)Ramírez F, Heyliger PR, Pan E (2006) Free vibration response of two-dimensional magneto-electro-elastic laminated plates. J Sound Vib 292:626–644Reitz JR, Milford FJ (1960) Foundations of electromagnetic theory. Addison-Wesley, BostonReng Z, Ionescu B, Besbes M, Razek A (1995) Calculation of mechanical deformation of magnetic materials in electromagnetic devices. IEEE Trans Magn 31(3):1873–1876Restuccia L (2010) On a thermodynamic theory for magnetic relaxation phenomena due to n microscopic phenomena described by n internal variables. J Non-Equilib Thermodyn 35:379–413Restuccia L, Kluitenberg GA (1988) On generalizations of the Debye equation for dielectric relaxation. Phys A 154:157–182Restuccia L, Kluitenberg GA (1992) On the heat dissipation function for dielectric relaxation phenomena in anisotropic media. Int J Eng Sci 30(3):305–315Riffat SB, Ma X (2003) Thermoelectrics: a review of present and potential applications. Appl Therm Eng 23:913–935Rinaldi C, Brenner H (2002) Body versus surface forces in continuum mechanics: is the Maxwell stress tensor a physically objective Cauchy stress? Phys Rev E 65:036615Rowe DM (ed) (1995) CRC handbook of thermoelectrics. CRC Press, UKRus G, Palma R, Pérez-Aparicio JL (2009) Optimal measurement setup for damage detection in piezoelectric plates. Int J Eng Sci 47:554–572Rus G, Palma R, Pérez-Aparicio JL (2012) Experimental design of dynamic model-based damage identification in piezoelectric ceramics. Mech Syst Signal Process 26:268–293Sadiku MNO (2001) Numerical techniques in electromagnetics. CRC Press LLC, Boca RatonSemenov AS, Kessler H, Liskowsky A, Balke H (2006) On a vector potential formulation for 3D electromechanical finite element analysis. Commun Numer Methods Eng 22:357–375Serra E, Bonaldi M (2008) A finite element formulation for thermoelastic damping analysis. Int J Numer Methods Eng 78(6):671–691Several. Wikipedia. Wikipedia: The Free Encyclopedia, SeveralSoh AK, Liu JX (2005) On the constitutive equations of magnetoelectroelastic solids. J Intell Mater Syst Struct 16:597–602Stefanescu DM (2011) Handbook of force transducers: principles and components. Springer, BerlinTamma KK, Namburu RR (1992) An effective finite element modeling/analysis approach for dynamic thermoelasticity due to second sound effects. Comput Mech 9:73–84Tang T, Yu W (2009) Micromechanical modeling of the multiphysical behavior of smart materials using the variational asymptotic method. Smart Mater Struct 18:1–14Taylor RL (2010) FEAP a finite element analysis program: user manual. University of California, Berkeley. http://www.ce.berkeley.edu/feapThurston RN (1994) Warren p. Mason (1900–1986) physicist, engineer, inventor, author, teacher. IEEE Trans Ultrason Ferroelectr Freq Control 41(4):425–434Tian X, Shen Y, Chen C, He T (2006) A direct finite element method study of generalized thermoelastic problems. Int J Solids Struct 43:2050–2063Tinder RF (2008) Tensor properties of solids: phenomenological development of the tensor properties of crystals. Morgan and Claypool, San RafaelTruesdell C (1968) Thermodynamics for beginners, in irreversible aspects of continuum mechanics. Springer, BerlinTzou HS, Ye R (1996) Pyroelectric and thermal strain effects of piezoelectric (PVDF and PZT) devices. Mech Syst Signal Process 10(4):459–469Walser R (1972) Application of pyromagnetic phenomena to radiation detection
Genetic Signatures in the Envelope Glycoproteins of HIV-1 that Associate with Broadly Neutralizing Antibodies
A steady increase in knowledge of the molecular and antigenic structure of the gp120 and gp41 HIV-1 envelope glycoproteins (Env) is yielding important new insights for vaccine design, but it has been difficult to translate this information to an immunogen that elicits broadly neutralizing antibodies. To help bridge this gap, we used phylogenetically corrected statistical methods to identify amino acid signature patterns in Envs derived from people who have made potently neutralizing antibodies, with the hypothesis that these Envs may share common features that would be useful for incorporation in a vaccine immunogen. Before attempting this, essentially as a control, we explored the utility of our computational methods for defining signatures of complex neutralization phenotypes by analyzing Env sequences from 251 clonal viruses that were differentially sensitive to neutralization by the well-characterized gp120-specific monoclonal antibody, b12. We identified ten b12-neutralization signatures, including seven either in the b12-binding surface of gp120 or in the V2 region of gp120 that have been previously shown to impact b12 sensitivity. A simple algorithm based on the b12 signature pattern was predictive of b12 sensitivity/resistance in an additional blinded panel of 57 viruses. Upon obtaining these reassuring outcomes, we went on to apply these same computational methods to define signature patterns in Env from HIV-1 infected individuals who had potent, broadly neutralizing responses. We analyzed a checkerboard-style neutralization dataset with sera from 69 HIV-1-infected individuals tested against a panel of 25 different Envs. Distinct clusters of sera with high and low neutralization potencies were identified. Six signature positions in Env sequences obtained from the 69 samples were found to be strongly associated with either the high or low potency responses. Five sites were in the CD4-induced coreceptor binding site of gp120, suggesting an important role for this region in the elicitation of broadly neutralizing antibody responses against HIV-1
Proteomic characterization of HIV-modulated membrane receptors, kinases and signaling proteins involved in novel angiogenic pathways
<p>Abstract</p> <p>Background</p> <p>Kaposi's sarcoma (KS), hemangioma, and other angioproliferative diseases are highly prevalent in HIV-infected individuals. While KS is etiologically linked to the human herpesvirus-8 (HHV8) infection, HIV-patients without HHV-8 and those infected with unrelated viruses also develop angiopathies. Further, HIV-Tat can activate protein-tyrosine-kinase (PTK-activity) of the vascular endothelial growth factor receptor involved in stimulating angiogenic processes. However, Tat by itself or HHV8-genes alone cannot induce angiogenesis <it>in vivo </it>unless specific proteins/enzymes are produced synchronously by different cell-types. We therefore tested a hypothesis that <it>chronic </it>HIV-<it>replication in non-endothelial cells </it>may produce novel factors that provoke angiogenic pathways.</p> <p>Methods</p> <p>Genome-wide proteins from HIV-infected and uninfected T-lymphocytes were tested by subtractive proteomics analyses at various stages of virus and cell growth <it>in vitro </it>over a period of two years. Several thousand differentially regulated proteins were identified by mass spectrometry (MS) and >200 proteins were confirmed in multiple gels. Each protein was scrutinized extensively by protein-interaction-pathways, bioinformatics, and statistical analyses.</p> <p>Results</p> <p>By functional categorization, 31 proteins were identified to be associated with various signaling events involved in angiogenesis. 88% proteins were located in the plasma membrane or extracellular matrix and >90% were found to be essential for regeneration, neovascularization and angiogenic processes during embryonic development.</p> <p>Conclusion</p> <p>Chronic HIV-infection of T-cells produces membrane receptor-PTKs, serine-threonine kinases, growth factors, adhesion molecules and many diffusible signaling proteins that have not been previously reported in HIV-infected cells. Each protein has been associated with endothelial cell-growth, morphogenesis, sprouting, microvessel-formation and other biological processes involved in angiogenesis (p = 10<sup>-4 </sup>to 10<sup>-12</sup>). Bioinformatics analyses suggest that overproduction of PTKs and other kinases in HIV-infected cells has <it>suppressed </it>VEGF/VEGFR-PTK expression and promoted <it>VEGFR-independent </it>pathways. This unique mechanism is similar to that observed in neovascularization and angiogenesis during embryogenesis. Validation of clinically relevant proteins by gene-silencing and translational studies <it>in vivo </it>would identify specific targets that can be used for early diagnosis of angiogenic disorders and future development of inhibitors of angiopathies. This is the first comprehensive study to demonstrate that HIV-infection alone, without any co-infection or treatment, can induce numerous "embryonic" proteins and kinases capable of generating novel <it>VEGF-independent </it>angiogenic pathways.</p
Reciprocal Prospective Relationships Between Loneliness and Weight Status in Late Childhood and Early Adolescence
Adolescents who do not conform to weight ideals are vulnerable to disapproval and victimization from peers in school. But, missing from the literature is a prospective examination of weight status and feelings of loneliness that might come from those experiences. Using data from the Québec Longitudinal Study of Child Development, we filled that gap by examining the prospective associations between loneliness and weight status when the sample was aged 10 to 13 years. At ages 10, 12, and 13 years, 1042 youth (572 females; 92% from French speaking homes) reported on their loneliness and were weighed and measured. Family income sufficiency was included in our analyses given its relationship with weight status, but also its possible link with loneliness during early adolescence. The findings showed that (1) weight status and loneliness were not associated concurrently; (2) weight status predicted increases in loneliness from ages 12 to 13 years; and (3) loneliness predicted increases in weight from ages 12 to 13 years among female adolescents, but weight loss among male adolescents. The fact that loneliness was involved in weight gain for females suggests that interventions focused on reducing loneliness and increasing connection with peers during early adolescence could help in reducing obesity
Reactive hyperemia index (RHI) and cognitive performance indexes are associated with histologic markers of liver disease in subjects with non-alcoholic fatty liver disease (NAFLD): a case control study
Abstract Background No study evaluated vascular health markers in subjects with non-alcoholic fatty liver disease (NAFLD) through a combined analysis of reactive hyperemia peripheral arterial tonometry (RH-PAT) and arterial stiffness indexes. Aim of the study We aimed to assess whether NAFLD and its histological severity are associated with impairment of arterial stiffness and RH-PAT indexes in a mixed cohort of patients with biopsy-proven NAFLD. Materials and methods The Kleiner classification was used to grade NAFLD grade. Pulse wave velocity (PWV) and augmentation index (Aix) were used as markers of arterial stiffness, whereas endothelial function was assessed using reactive hyperemia index (RHI). The mini-mental state examination (MMSE) was administered to test cognitive performance. Results 80 consecutive patients with biopsy-proven NAFLD and 83 controls without fatty liver disease. NAFLD subjects showed significantly lower mean RHI, higher mean arterial stiffness indexes and lower mean MMSE score. Multivariable analysis after correction for BMI, dyslipidaemia, hypertension, sex, diabetes, age and cardiovascular disease showed that BMI, diastolic blood pressure and RHI are significantly associated to NAFLD. Simple linear regression analysis showed among non-alcoholic steatohepatitis (NASH) subjects a significant negative relationship between ballooning grade and MMSE and a significant positive association between Kleiner steatosis grade and augmentation index. Conclusions Future research will be addressed to evaluate the relationship between inflammatory markers and arterial stiffness and endothelial function indexes in NAFLD subjects. These study will evaluate association between cardiovascular event incidence and arterial stiffness, endothelial and cognitive markers, and they will address the beneficial effects of cardiovascular drugs such as statins and ACE inhibitors on these surrogate markers in NAFLD subjects
- …