Unlearned Lessons from Risk, Debt Service, Bank Credit, and Asymmetric Information

This paper presents a model of the economy that explains the economic bubbles, based on bank credit, debt service and risk. In the first period of the model, banks offer too much credit seeking to maximise their expected profits. The excessive debt created in the boom period generates, in the second-period, the expansion of the debt bubble, which induces failures in the financial market and the downturn of the overall economy. Business cycles are inherent in the free market systems. They may be caused by endogenous factors of financial markets and, given the absence of adequate, effective regulation, they may be unavoidable. Credit crunch in the financial market is therefore highly probable. In order to reduce substantially the risk of such occurrences, economic and financial policies are proposed. Key words: Asymmetric information, bank credit, risk, debt service and business cycle

Transient Nucleation near the Mean-Field Spinodal

Nucleation is considered near the pseudospinodal in a one-dimensional $\phi^4$ model with a non-conserved order parameter and long-range interactions. For a sufficiently large system or a system with slow relaxation to metastable equilibrium, there is a non-negligible probability of nucleation occurring before reaching metastable equilibrium. This process is referred to as transient nucleation. The critical droplet is defined to be the configuration of maximum likelihood that is dynamically balanced between the metastable and stable wells. Time-dependent droplet profiles and nucleation rates are derived, and theoretical results are compared to computer simulation. The analysis reveals a distribution of nucleation times with a distinct peak characteristic of a nonstationary nucleation rate. Under the quench conditions employed, transient critical droplets are more compact than the droplets found in metastable equilibrium simulations and theoretical predictions.Comment: 7 Pages, 5 Figure

Study of Phase Reconstruction Techniques applied to Smith-Purcell Radiation Measurements

Measurements of coherent radiation at accelerators typically give the absolute value of the beam profile Fourier transform but not its phase. Phase reconstruction techniques such as Hilbert transform or Kramers Kronig reconstruction are used to recover such phase. We report a study of the performances of these methods and how to optimize the reconstructed profiles.Comment: Presented at IPAC'14 - THPME08

Puntos cuánticos: nueva aportación de la nanotecnología en investigación y medicina

Los Puntos Cuántico (PCs) son nanocristales más fotoestables, monocromáticos y brillantes que cualquier fluorocromo. Estas cualidades y su capacidad de formar múltiples constructos (funcionalización con anticuerpos, oligonucleótidos, Biotina, lectinas, iones magnéticos, etc.) les otorgan una enorme versatilidad analítica y una sensibilidad a nivel de molécula única. Además de mejorar determinaciones estándar como el PSA, los PCs ofrecen nuevas alternativas en Western blotting y citometría de flujo. La manufacturación de “laboratorios en un chip” es uno de los productos nanotecnológicos más destacados ya que permiten múltiples análisis simultáneos, a tiempo real, con un coste reducido y cantidades ínfimas de muestra. En el campo de la biotecnología los PCs son útiles en la identificación génica por código de barras multicolor en microchips. Los PCs unidos a ACs específicos permiten la detección por fluorescencia de diversas dianas en rutas metabólicas intracitoplasmáticas de células vivas sin alterar su fisiología. Más aún, permiten comprender, a la vez, el tráfico de proteínas, su localización, reciclaje y función en lo que se viene llamando Proteómica Visual. Nuevas aplicaciones en oncología clínica permiten identificar células cancerosas aisladas en sangre circulante y una mayor exactitud en el mapeado de Glanglio centinela en neoplasias de mama, así como conseguir discriminar selectivamente el nódulo tumoral en neurocirugía cerebral. ¿Estamos a las puertas del diagnóstico y terapia secuenciales por PCs en el mismo acto médico; biopsia óptica?. La medicina regenerativa promete terapias sustitutivas de órganos y tejidos generados “in vitro”. Los nanotubos de carbono actúan mejorando los sustratos para el crecimiento celular diferenciado de células madre. Además, son útiles para la liberación controlada de medicinas, en particular citoestáticos unidos a ACs oncoespecíficos, y como vehículo de vectores genéticos. La Nanotecnología y los Puntos Quánticos en particular representan el futuro del diagnóstico del laboratorio, la biología celular y la terapia oncológica.Quantum Dots (QDs) are more fotostable, monochromatic and brilliant than any standard fluorocrome. These qualities and their capacity to build different constructors (targeted with antibodies, oligonucleotides, Biotine, lectines, magnetic ions, etc) allow them a wide versatility and sensibility, even to single molecular levels. Furthermore, improving standard PSA and other tests QDs represent a new alternative in Western blotting and flow citometry. Laboratories-on-a-chip, one of the more original nanoproducts, makes possible a wide variety of clinical tests simultaneously at real time, low cost and a minimal amount of sample. QDs are also being employed in biotechnology to genetic identifications through multicolour barcodes on microchips. QDs nanocrystal–labeled antibodies allow simultaneous and safe detection of multiple molecules in metabolic tracts inside living cells. Even traffic, localization, turnover and function of proteins can be understood at a time, giving birth to Visual Proteomics. New implementations in clinical oncology enable cancer cells recognition in circulating blood, more precise identification of the sentinel node in breast neoplasia as well as selectively delimitate malignant growths in brain surgery. Are we close to a sequential diagnosis and therapy in a single medical act by Quantum Dots; the optical biopsy? Regenerative medicine promises replacement therapy of organs and tissues growth “in vitro”. Carbon Nanotubes improve the substratum to steam cells differentiation as well as under control drugs release, particularly targeted citostatics or genetic vectors. Nanotechnology and particularly Quantum Dots represent the future tools for laboratory diagnosis, cell biology and cancer therapy

Relevance or irrelevance of capital structure?

In this paper we examine the effects of asymmetric information on the nature of financial equilibrium and on the capital structure of firms. In the first model presented, the financial contracts on offer involve pooling equilibrium with no adverse selection. However, in the special case analyzed, where contracts are of mixed form, there may be a separating equilibrium and also equilibrium may not exist. Interesting result is that the separating equilibrium found is not economically efficient since aggregate investments falls short of first-best level. More importantly, capital structure does matter. The relative magnitude of outside equity makes a real difference to the quantity of aggregate investment in equilibrium

Clival chordomas: The endoscopic transnasal transsphenoidal approach

Os cordomas da base do crânio são tumores raros, localmente destrutivos, que constituem um desafio cirúrgico pela proximidade a estruturas neurovasculares vitais e ao elevado potencial de recidiva. Os autores descrevem o caso de uma mulher de 45 anos, com quadro de cefaleias, anisocória e diplopia, com cinco meses de evolução, cujos exames complementares de diagnóstico revelaram uma volumosa lesão expansiva dos 2/3 superiores do clivus, com preenchimento do seio esfenoidal, destruição selar e extensão para ambos os seios cavernosos. Procedeu-se a excisão da lesão, após biopsia diagnóstica compatível com cordoma, por abordagem endoscópica endonasal transesfenoidal (EET), guiada por neuronavegação. Com 3 meses de seguimento, a doente encontra-se clinicamente bem e a ressonância magnética revela eventual resíduo tumoral no seio cavernoso direito. A cirurgia EET constitui uma alternativa minimamente invasiva na abordagem de lesões expansivas da base do crânio, possibilitando, em casos seleccionados, resultados similares e com menor morbilidade, relativamente às técnicas cirúrgicas clássicas.info:eu-repo/semantics/publishedVersio

The GREATS Hβ\beta+[OIII] Luminosity Function and Galaxy Properties at z∼8\mathbf{z\sim8}: Walking the Way of JWST

The James Webb Space Telescope will allow to spectroscopically study an unprecedented number of galaxies deep into the reionization era, notably by detecting [OIII] and H$\beta$ nebular emission lines. To efficiently prepare such observations, we photometrically select a large sample of galaxies at $z\sim8$ and study their rest-frame optical emission lines. Combining data from the GOODS Re-ionization Era wide-Area Treasury from Spitzer (GREATS) survey and from HST, we perform spectral energy distribution (SED) fitting, using synthetic SEDs from a large grid of photoionization models. The deep Spitzer/IRAC data combined with our models exploring a large parameter space enables to constrain the [OIII]+H$\beta$ fluxes and equivalent widths for our sample, as well as the average physical properties of $z\sim8$ galaxies, such as the ionizing photon production efficiency with $\log(\xi_\mathrm{ion}/\mathrm{erg}^{-1}\hspace{1mm}\mathrm{Hz})\geq25.77$. We find a relatively tight correlation between the [OIII]+H$\beta$ and UV luminosity, which we use to derive for the first time the [OIII]+H$\beta$ luminosity function (LF) at $z\sim8$. The $z\sim8$ [OIII]+H$\beta$ LF is higher at all luminosities compared to lower redshift, as opposed to the UV LF, due to an increase of the [OIII]+H$\beta$ luminosity at a given UV luminosity from $z\sim3$ to $z\sim8$. Finally, using the [OIII]+H$\beta$ LF, we make predictions for JWST/NIRSpec number counts of $z\sim8$ galaxies. We find that the current wide-area extragalactic legacy fields are too shallow to use JWST at maximal efficiency for $z\sim8$ spectroscopy even at 1hr depth and JWST pre-imaging to $\gtrsim30$ mag will be required.Comment: 13 pages, 9 figures, accepted for publication in MNRA

Influence of the concrete mechanical properties on the efficacy of the shear strengthening intervention on RC beams by NSM technique

The occurrence of a failure mode, different from debonding, consisting on the detachment, from the beam core, of “two concrete lateral walls” containing the glued laminates, highlights the paramount importance of concrete mechanical properties on the effectiveness of NSM shear strengthening technique. A new mechanical-analytical interpretation of the phenomenon affecting the ultimate behaviour of RC beams NSM-strengthened in shear is presented along with the main findings. This approach takes into account the possibility that the shear strengthening contribution of the NSM laminates can be limited by the three following failure modes: debonding, concrete tensile fracture and laminates’ tensile rupture. The interaction between laminates can be also accounted for. The proposed mechanical interpretation of the NSM laminates behaviour can be extended to NSM rods.Fundação para a Ciência e a Tecnologia (FCT) - programa “CUTINSHEAR - Performance assessment of an innovative structural FRP strengthening technique using an integrated system based on optical fiber sensors” s, POCTI/ECM/59033/2004. This work has been partially carried out under the program “Dipartimento di Protezione Civile – Consorzio RELUIS”, signed on 2005-07-11 (n. 540), Research Line 8, whose financial support is greatly appreciatePrograma “Dipartimento di Protezione Civile – Consorzio RELUIS” nº 540Research Line 8Empreiteiros CasaisS&P®Secil (Unibetão, Braga)Degussa