Phase Transition of Lipid Multilameller Aqueous Suspension under High Pressure. II. Structural Analyses of Lipid Bimembrane under High Pressure by X-Ray Studies

Abstract

We present a simple superfield lagrangian for massive supergravity. It comprises the minimal supergravity lagrangian with interactions as well as mass terms for the metric superfield and the chiral compensator. This is the natural generalization of the Fierz-Pauli lagrangian for massive gravity which comprises mass terms for the metric and its trace. We show that the on-shell bosonic and fermionic fields are degenerate and have the appropriate spins: 2, 3/2, 3/2 and 1. We then study this interacting lagrangian using goldstone superfields. We find that a chiral multiplet of goldstones gets a kinetic term through mixing, just as the scalar goldstone does in the non-supersymmetric case. This produces Planck scale (M Pl ) interactions with matter and all the discontinuities and unitarity bounds associated with massive gravity. In particular, the scale of strong coupling is (M Pl m 4 ) 1/5 , where m is the multiplet's mass. Next, we consider applications of massive supergravity to deconstruction. We estimate various quantum effects which generate non-local operators in theory space. As an example, we show that the single massive supergravity multiplet in a 2-site model can serve the function of an extra dimension in anomaly mediation.

Manipulating Mesophase Behavior of Hydrated DHPE: An X-ray Diffraction Study of Temperature and Pressure Effects

“…2,5,6,[30][31][32][33] The L R /H II transition was not investigated in any detail in this study. However, the L R /H II transition temperature did increase at elevated pressures (Figure 2), which implies that a volume increase (see eq 6) is associated with this phase change that is known to be endothermic.…”

“…The effects of hydrostatic pressure and temperature on lipid mesophase behavior and structure have been studied extensively using direct structural methods such as X-ray − and neutron diffraction. ,, Here, an investigation of pressure- and temperature-induced changes in equilibrium mesophase structure in the fully hydrated 1,2-dihexadecyl- sn -glycero-3-phosphoethanolamine (DHPE) system is described. The results of the study provide valuable insight into the structure−thermodynamic variable relationship and provide important quantitative mensurations for use in ongoing studies of the kinetics and mechanism of lipid phase transitions (see ref , for example).…”

“…The effects of hydrostatic pressure and temperature on lipid mesophase behavior and structure have been studied extensively using direct structural methods such as X-ray [1][2][3][4][5] and neutron diffraction. 1,6,7 Here, an investigation of pressure-and temperature-induced changes in equilibrium mesophase structure in the fully hydrated 1,2-dihexadecyl-sn-glycero-3-phosphoethanolamine (DHPE) system is described.…”

Kinetics of the barotropic ripple (P beta')/lamellar liquid crystal (L alpha) phase transition in fully hydrated dimyristoylphosphatidylcholine (DMPC) monitored by time-resolved x-ray diffraction

“…The influence of pressure on the structural properties of model membranes has been extensively studied using techniques such as infrared and Raman spectroscopy (Wong, 1984;Wong and Mantsch, 1988;Wong and Huang, 1989), densitometry (Vennemann et al, 1986), and volumetric measurements (Tosh and Collins, 1986;Johnson et al, 1983). Considerably less work has been carried out using diffraction methods (Stamatoff et al, 1978;Utoh and Takemura, 1985; Braganza and Worcester, 1986; Caffrey and Mencke, 1989;Shyamsunder et al, 1989;Winter and Pilgrim, 1989).…”

Effects of physiologically relevant pressures of helium on the structure of cholesterol-containing lipid bilayers. A neutron diffraction study

“…Because of the central role that membranes play in nervous conduction, the effects of pressure on simple model membranes have been extensively studied (for a review, see Macdonald, 1984), although there has been very little work using direct structural methods such as x-ray and neutron diffraction. Most of the diffraction work that has been done has concentrated on the effects of high hydrostatic pressures on lipid-phase transitions in cholesterol-free bilayers (Stamatoff et al, 1978;Utoh and Takemura, 1985;Braganza and Worcester, 1986a;Shyamsunder et al, 1989;Winter et al, 1989), although one report (Braganza and Worcester, 1986b) included pressure effects on cholesterol-containing bilayers. Be-cause the physiological effects of high pressures of helium are known to be different to those of high pressure per se (Macdonald, 1975;Dodson et al, 1985), there may also be differences in their effects on membrane structure, yet we know of no structural work that has been reported on the effects of physiologically relevant pressures (1-200 atm) of helium on the structure of lipid bilayers.…”