Singular Short Range Potentials in the J-Matrix Approach

We use the tools of the J-matrix method to evaluate the S-matrix and then deduce the bound and resonance states energies for singular screened Coulomb potentials, both analytic and piecewise differentiable. The J-matrix approach allows us to absorb the 1/r singularity of the potential in the reference Hamiltonian, which is then handled analytically. The calculation is performed using an infinite square integrable basis that supports a tridiagonal matrix representation for the reference Hamiltonian. The remaining part of the potential, which is bound and regular everywhere, is treated by an efficient numerical scheme in a suitable basis using Gauss quadrature approximation. To exhibit the power of our approach we have considered the most delicate region close to the bound-unbound transition and compared our results favorably with available numerical data.Comment: 14 pages, 5 tables, 2 figure

Features of heavy physics in the CMB power spectrum

The computation of the primordial power spectrum in multi-field inflation models requires us to correctly account for all relevant interactions between adiabatic and non-adiabatic modes around and after horizon crossing. One specific complication arises from derivative interactions induced by the curvilinear trajectory of the inflaton in a multi-dimensional field space. In this work we compute the power spectrum in general multi-field models and show that certain inflaton trajectories may lead to observationally significant imprints of `heavy' physics in the primordial power spectrum if the inflaton trajectory turns, that is, traverses a bend, sufficiently fast (without interrupting slow roll), even in cases where the normal modes have masses approaching the cutoff of our theory. We emphasise that turning is defined with respect to the geodesics of the sigma model metric, irrespective of whether this is canonical or non-trivial. The imprints generically take the form of damped superimposed oscillations on the power spectrum. In the particular case of two-field models, if one of the fields is sufficiently massive compared to the scale of inflation, we are able to compute an effective low energy theory for the adiabatic mode encapsulating certain relevant operators of the full multi-field dynamics. As expected, a particular characteristic of this effective theory is a modified speed of sound for the adiabatic mode which is a functional of the background inflaton trajectory and the turns traversed during inflation. Hence in addition, we expect non-Gaussian signatures directly related to the features imprinted in the power spectrum.Comment: 41 pages, 6 figures, references updated, minor modifications. Version to appear in JCAP. v4: Equations (4.28) and (4.30) and Figures 5 and 6 correcte

Beauty is Distractive: Particle production during multifield inflation

We consider a two-dimensional model of inflation, where the inflationary trajectory is "deformed" by a grazing encounter with an Extra Species/Symmetry Point (ESP) after the observable cosmological scales have left the Hubble radius. The encounter entails a sudden production of particles, whose backreaction causes a bending of the trajectory and a temporary decrease in speed, both of which are sensitive to initial conditions. This "modulated" effect leads to an additional contribution to the curvature perturbation, which can be dominant if the encounter is close. We compute associated non-Gaussianities, the bispectrum and its scale dependence as well as the trispectrum, which are potentially detectable in many cases. In addition, we consider a direct modulation of the coupling to the light field at the ESP via a modulaton field, a mixed scenario whereby the modulaton is identified with a second inflaton, and an extended Extra Species Locus (ESL); all of these scenarios lead to similar additional contributions to observables. We conclude that inflaton interactions throughout inflation are strongly constrained if primordial non-Gaussianities remain unobserved in current experiments such as PLANCK. If they are observed, an ESP encounter leaves additional signatures on smaller scales which may be used to identify the model.Comment: 41 pages, 6 figures; v2: references and minor clarifications added, conclusions unchange

Optimization of conventional and ultrasound assisted extraction of flavonoids from grapefruit (Citrus paradisi L.) solid wastes

Flavonoid compounds from grapefruit wastes were obtained by conventional solid liquid extraction (CE) and ultrasound assisted extraction (USE). Naringin was by far the most abundant flavonoid in the extracts ranging from 18 to 28 mg/g dw for CE and 24-36 mg/g dw for USE. Response surface methodology allowed obtaining predictive models for total phenolic content (TPC) and total antioxidant activity (TAA) as a function of the process variables ethanol concentration (Etc) (defined as weight of ethanol/weight of solution), temperature (T) and time (t) with reasonable success (CE-TPC, R-2 = 0.86, CE-TAA, R-2 = 0.85; USE-TPC, R-2 = 0.82; USE, TAA, R-2 = 0.86). USE was very effective when compared with conventional solvent extraction, allowing higher extraction yields (on average TPC 50% and TAA 66% higher) with lower temperatures and extraction times. Although the optimum process conditions indicate the use of a low ethanol concentration and ultrasounds (T = 25 degrees C, EtC = 0.4 (g/g) (40 g/100 g) and t = 55 min leading to TPC = 80.0 mg GAE/g dw and TAA = 38.3 mmol trolox/g dw), it has been proved that an USE treatment free of organic solvent (EtC = 0 g/g), at moderate temperature (25 degrees C) and short time (t = 3 min) leads to similar results (TPC = 753 mg GAE/g dw and TAA = 31.9 mmol trolox/g dw), suggesting its use for economic and environmental purposes.The authors acknowledge the Universitat Politecnica de Valencia (Spain) for its financial support through the project 1965 (PAID05-11).Garcia-Castello, EM.; Rodríguez López, AD.; Mayor López, L.; Ballesteros, R.; Conidi, C.; Cassano, A. (2015). Optimization of conventional and ultrasound assisted extraction of flavonoids from grapefruit (Citrus paradisi L.) solid wastes. Food Science and Technology. 64(2):1114-1122. https://doi.org/10.1016/j.lwt.2015.07.024S1114112264

Powerful quasars with young jets in multi-epoch radio surveys

High Energy Astrophysic

Liposomes in Biology and Medicine

Drug delivery systems (DDS) have become important tools for the specific delivery of a large number of drug molecules. Since their discovery in the 1960s liposomes were recognized as models to study biological membranes and as versatile DDS of both hydrophilic and lipophilic molecules. Liposomes--nanosized unilamellar phospholipid bilayer vesicles--undoubtedly represent the most extensively studied and advanced drug delivery vehicles. After a long period of research and development efforts, liposome-formulated drugs have now entered the clinics to treat cancer and systemic or local fungal infections, mainly because they are biologically inert and biocompatible and practically do not cause unwanted toxic or antigenic reactions. A novel, up-coming and promising therapy approach for the treatment of solid tumors is the depletion of macrophages, particularly tumor associated macrophages with bisphosphonate-containing liposomes. In the advent of the use of genetic material as therapeutic molecules the development of delivery systems to target such novel drug molecules to cells or to target organs becomes increasingly important. Liposomes, in particular lipid-DNA complexes termed lipoplexes, compete successfully with viral gene transfection systems in this field of application. Future DDS will mostly be based on protein, peptide and DNA therapeutics and their next generation analogs and derivatives. Due to their versatility and vast body of known properties liposome-based formulations will continue to occupy a leading role among the large selection of emerging DDS