Universal Properties at the Quantum Superconductor-to-Insulator Transition of Cuprates

We sketch the universal critical properties of a quantum superconductor to insulator transition in two spatial dimensions, using the scaling theory of quantum critical phenomena. Comparison with experimental data reveals that the resulting universal relations among transition temperature, zero temperature penetration depth, and residual resistivity, as well as for the asymptotic linear temperature dependence of the penetration depth, appear to apply in a rather extended doping regime, ranging from the underdoped limit up to the nearly optimum dopant concentration. This behavior uncovers the dominant role of quantum fluctuations in this doping regime.     

Detection and estimation of multiplexed soliton signals

Solitons are eigenfunction solutions to certain nonlinear wave equations that arise in a variety of natural and man-made systems. Their rich properties and tractability make them an intriguing component of such systems, often describing the large-scale or long-term behavior of natural systems, or the information content in certain communication or signal processing systems. However, it is often difficult to detect or estimate the parameters of solitons in such systems due to the presence of strong nonsoliton components or the nonlinear interaction of multiple solitons. The objective of this paper is to develop and investigate the detection and estimation of soliton signals. As a framework for this study, we consider using these nonlinear systems as both signal generators and signal processors in a form of multiplexed soliton communication. In contrast to more conventional uses of solitons in a communications context, our communication system uses soliton systems for signal generation and multiplexing for transmission over traditional linear channels. In addition to their mathematical tractability and the simplicity of the analog circuits used to generate and process them, we show that the soliton signal dynamics may also provide a mechanism for decreasing transmitted signal energy while enhancing signal detection and parameter estimation performance     

Uncertainty inequalities for the continuous wavelet transform

Uncertainty inequalities of Heisenberg-type are established for the continuous wavelet transform resting on classical Heisenberg and Heisenberg-von Keumann principles     

mRNA and cytoskeletal filaments

There is evidence that low birth weight and poor growth in early life cause a long-term predisposition to non-insulin-dependent diabetes. Morphological changes were assessed in fetal rat pancreas subjected to both pre- and post-natal maternal protein deprivation (LP). Further groups were subjected to purely prenatal maternal protein deprivation (preLP) and purely postnatal maternal protein deprivation (postLP), as well as a control group. The results show that the LP and postLP groups had fewer but larger islets than the control group, while the preLP group had more numerous, smaller islets. All three low protein groups had more irregularly shaped islets than the control group. There was a reduction in the amount of beta cells within each islet in all three protein-deprived groups. The LP and postLP groups showed a reduction in the percentage of islet tissue and beta cells per pancreas, but the percentage of islet tissue expressed per unit body weight was similar in all four groups. These results show that in maternal protein deprivation, homeostatic mechanisms ensure a constant amount of pancreatic endocrine tissue per unit of body weight. However, there remain major structural changes in the size, shape, and composition of the islets. These results support the theory that early development profoundly affects the structure of the pancreas and may play a role in the later development of adult diseases, such as non-insulin-dependent diabetes mellitus.     

NMR structure of neuromedin C, a neurotransmitter with an amino terminal CuII-, NiII-binding (ATCUN) motif

The structure of neuromedin C, a 10-residue bombesin-like neuropeptide with the sequence Gly-Asn-His-Trp-Ala-Val-Gly-His-Leu-Met-NH2, has been investigated. Like human serum albumin, neuromedin C contains the amino-terminal CuII-, NiII-binding (ATCUN) motif which has high affinity for CuII and NiII. The solution structure of the NiII-peptide complex has been calculated based on 2D ROESY data obtained at 25 degrees C, using a hybrid distance geometry-simulated annealing approach. Comparison of 1H, 13C and 15N chemical shifts and ROESY data in the presence and absence of NiII demonstrates that the metal binds at the N-terminus of the peptide, leading to a conformational change. The metal complex adopts a conformation comprising two connected turns including residues 1Gly to 3His and 5Ala to 8His. The first turn corresponds to the NiII coordination ligands in a square planar conformation, and the second reflects the interaction between 4Trp and 8His. The results may have important physiological implications in the phenomenon of neurotransmission.     

Characterization of PV array output using a small number of measured parameters

The purpose of the present study was to develop a sufficiently good fit for the measured I–V curve of a PV module and array using only three easily measurable parameters: —the open-circuit voltage (V_oc); —the short-circuit current (I_sc); —the maximum power (P_m). With an additional three parameters ( ; ; ) it is possible to describe any I–V curve, taking into account cell temperature T and solar radiation Q. This method has been tested on various solar array panels as well as on a single 10 cm dia. solar cell. The difference between the real curve and the proposed fit was found to be less than 3 percent for a fixed temperature and radiation and about 6 percent for various combinations of temperature and radiation.