Time-dependent quantum many-body theory of identical bosons in a double well: Early time ballistic interferences of fragmented and number entangled states

A time-dependent multiconfigurational self-consistent field theory is presented to describe the many-body dynamics of a gas of identical bosonic atoms confined to an external trapping potential at zero temperature from first principles. A set of generalized evolution equations are developed, through the time-dependent variational principle, which account for the complete and self-consistent coupling between the expansion coefficients of each configuration and the underlying one-body wave functions within a restricted two state Fock space basis that includes the full effects of the condensate's mean field as well as atomic correlation. The resulting dynamical equations are a classical Hamiltonian system and, by construction, form a well-defined initial value problem. They are implemented in an efficient numerical algorithm. An example is presented, highlighting the generality of the theory, in which the ballistic expansion of a fragmented condensate ground state is compared to that of a macroscopic quantum superposition state, taken here to be a highly entangled number state, upon releasing the external trapping potential. Strikingly different many-body matter-wave dynamics emerge in each case, accentuating the role of both atomic correlation and mean-field effects in the two condensate states.Comment: 16 pages, 5 figure

Finsler geodesics in the presence of a convex function and their applications

We obtain a result about the existence of only a finite number of geodesics between two fixed non-conjugate points in a Finsler manifold endowed with a convex function. We apply it to Randers and Zermelo metrics. As a by-product, we also get a result about the finiteness of the number of lightlike and timelike geodesics connecting an event to a line in a standard stationary spacetime.Comment: 16 pages, AMSLaTex. v2 is a minor revision: title changed, references updated, typos fixed; it matches the published version. This preprint and arXiv:math/0702323v3 [math.DG] substitute arXiv:math/0702323v2 [math.DG

Multiconfigurational Hartree-Fock theory for identical bosons in a double well

Multiconfigurational Hartree-Fock theory is presented and implemented in an investigation of the fragmentation of a Bose-Einstein condensate made of identical bosonic atoms in a double well potential at zero temperature. The approach builds in the effects of the condensate mean field and of atomic correlations by describing generalized many-body states that are composed of multiple configurations which incorporate atomic interactions. Nonlinear and linear optimization is utilized in conjunction with the variational and Hylleraas-Undheim theorems to find the optimal ground and excited states of the interacting system. The resulting energy spectrum and associated eigenstates are presented as a function of double well barrier height. Delocalized and localized single configurational states are found in the extreme limits of the simple and fragmented condensate ground states, while multiconfigurational states and macroscopic quantum superposition states are revealed throughout the full extent of barrier heights. Comparison is made to existing theories that either neglect mean field or correlation effects and it is found that contributions from both interactions are essential in order to obtain a robust microscopic understanding of the condensate's atomic structure throughout the fragmentation process.Comment: 21 pages, 13 figure

Age-dependent changes in insulin-like immunoreactivity in rat submandibular salivary glands.

In recent years, a growing interest had arisen in hormonal factors in salivary glands. We have investigated the changes in the content of an insulin-like immunoreactive (ILI) compound in the submandibular salivary glands of Sprague Dawley rats during physiological aging, in the range 15 days-27 months. The amount of ILI in the submandibular glands of young adult rats was found to be doubled in the post-natal period until the age of puberty and was maintained in senescence. No significant correlation was found between age-dependent variations in ILI levels of submandibular salivary glands and circulating insulin concentrations, further supporting previous indications that ILI is being synthesized in situ. It is possible that ILI could exert paracrine effects within the glands, as regards the development of other glandular structures during the first months of life, as well as the preservation of glandular function in senescent animals as well

UV Raman lidar measurements of relative humidity for the characterization of cirrus cloud microphysical properties

Abstract. Raman lidar measurements performed in Potenza by the Raman lidar system BASIL in the presence of cirrus clouds are discussed. Measurements were performed on 6 September 2004 in the frame of the Italian phase of the EAQUATE Experiment. The major feature of BASIL is represented by its capability to perform high-resolution and accurate measurements of atmospheric temperature and water vapour, and consequently relative humidity, both in daytime and night-time, based on the application of the rotational and vibrational Raman lidar techniques in the UV. BASIL is also capable to provide measurements of the particle backscatter and extinction coefficient, and consequently lidar ratio (at the time of these measurements, only at one wavelength), which are fundamental to infer geometrical and microphysical properties of clouds. A case study is discussed in order to assess the capability of Raman lidars to measure humidity in presence of cirrus clouds, both below and inside the cloud. While air inside the cloud layers is observed to be always under-saturated with respect to water, both ice super-saturation and under-saturation conditions are found inside these clouds. Upper tropospheric moistening is observed below the lower cloud layer. The synergic use of the data derived from the ground based Raman Lidar and of spectral radiances measured by the NAST-I Airborne Spectrometer allows the determination of the temporal evolution of the atmospheric cooling/heating rates due to the presence of the cirrus cloud. Lidar measurements beneath the cirrus cloud layer have been interpreted using a 1-D cirrus cloud model with explicit microphysics. The 1-D simulations indicate that sedimentation-moistening has contributed significantly to the moist anomaly, but other mechanisms are also contributing. This result supports the hypothesis that the observed mid-tropospheric humidification is a real feature which is strongly influenced by the sublimation of precipitating ice crystals. Results illustrated in this study demonstrate that Raman lidars, like the one used in this study, can resolve the spatial and temporal scales required for the study of cirrus cloud microphysical processes and appear sensitive enough to reveal and quantify upper tropospheric humidification associated with cirrus cloud sublimation

PRIMA-1 induces autophagy in cancer cells carrying mutant or wild type p53.

PRIMA-1 is a chemical compound identified as a growth suppressor of tumor cells expressing mutant p53. We previously found that in the MDA-MB-231 cell line expressing high level of the mutant p53-R280K protein, PRIMA-1 induced p53 ubiquitination and degradation associated to cell death. In this study, we investigated the ability of PRIMA-1 to induce autophagy in cancer cells. In MDA-MB-231 and HCT116 cells, expressing mutant or wild type p53, respectively, autophagy occurred following exposure to PRIMA-1, as shown by acridine orange staining, anti-LC3 immunofluorescence and immunoblots, as well as by electron microscopy. Autophagy was triggered also in the derivative cell lines knocked-down for p53, although to a different extent than in the parental cells expressing mutant or wild type p53. In particular, while wild type p53 limited PRIMA-1 induced autophagy, mutant p53 conversely promoted autophagy, thus sustaining cell viability following PRIMA-1 treatment. Therefore, the autophagic potential of PRIMA-1, besides being cell context dependent, could be modulated in a different way by the presence of wild type or mutant p53. Furthermore, since both cell lines lacking p53 were more sensitive to the cytotoxic effect of PRIMA-1 than the parental ones, our findings suggest that a deregulated autophagy may favor cell death induced by this drug

Gravitational lensing in spherically symmetric static spacetimes with centrifugal force reversal

In Schwarzschild spacetime the value $r=3m$ of the radius coordinate is characterized by three different properties: (a) there is a ``light sphere'', (b) there is ``centrifugal force reversal'', (c) it is the upper limiting radius for a non-transparent Schwarschild source to act as a gravitational lens that produces infinitely many images. In this paper we prove a theorem to the effect that these three properties are intimately related in {\em any} spherically symmetric static spacetime. We illustrate the general results with some examples including black-hole spacetimes and Morris-Thorne wormholes.Comment: 18 pages, 3 eps-figure

Alteration of beta-cell constitutive NO synthase activity is involved in the abnormal insulin response to arginine in a new rat model of type 2 diabetes.

We have previously obtained a new type 2 diabetic syndrome in adult rats given streptozotocin and nicotinamide, characterized by reduced beta-cell mass, partially preserved insulin response to glucose and tolbutamide and excessive responsiveness to arginine. We have also established that the neuronal isoform of constitutive NO synthase (nNOS) is expressed in beta-cells and modulates insulin secretion. In this study, we explored the kinetics of glucose- and arginine-stimulated insulin release in perifused isolated islets as well as the effect of N-omega-nitro-L-arginine methyl ester (L-NAME), a NOS inhibitor, to get insight into the possible mechanisms responsible for the arginine hypersensitivity observed in vitro in this and other models of type 2 diabetes. A reduced first phase and a blunted second phase of insulin secretion were observed upon glucose stimulation of diabetic islets, confirming previous data in the isolated perfused rat pancreas. Exposure of diabetic islets to 10 mM arginine, in the presence of 2.8 mM glucose, elicited a remarkable monophasic increment in insulin release, which peaked at 639 +/- 31 pg/islet/min as compared to 49 +/- 18 pg/islet/min in control islets (P << 0.01). The addition of L-NAME to control islets markedly enhanced the insulin response to arginine, as expected from the documented inhibitory effect exerted by nNOS activity in normal beta-cells, whereas it did not further modify the insulin secretion in diabetic islets, thus implying the occurrence of a defective nNOS activity in these islets. A reduced expression of nNOS mRNA was found in the majority but not in all diabetic islet preparations and therefore cannot totally account for the absence of L-NAME effect, that might also be ascribed to post-transcriptional mechanisms impairing nNOS catalytic activity. In conclusion, our results provide for the first time evidence that functional abnormalities of type 2 experimental diabetes, such as the insulin hyper-responsiveness to arginine, could be due to an impairment of nNOS expression and/or activity in beta-cell

Topological classification of black Hole: Generic Maxwell set and crease set of horizon

The crease set of an event horizon or a Cauchy horizon is an important object which determines qualitative properties of the horizon. In particular, it determines the possible topologies of the spatial sections of the horizon. By Fermat's principle in geometric optics, we relate the crease set and the Maxwell set of a smooth function in the context of singularity theory. We thereby give a classification of generic topological structure of the Maxwell sets and the generic topologies of the spatial section of the horizon.Comment: 22 pages, 6 figure