A theory of banks, bonds, and the distribution of firm size

We draw on stylized facts from the finance literature to build a model where altering the relative costs of bank and bond financing changes the entire distribution of firm size, with implications for the aggregate capital stock, output, and welfare. Reducing transactions costs in the bond market increases the output and profits of mid-sized firms at the expense of both the largest and smallest firms. In contrast, reducing the frictions involved in bank lending promotes the expansion of the smallest firms while all other firms shrink, even as it increases the profitability of both small and mid-size firms. Although both policies increase aggregate output and welfare, they have opposite effects on the extensive margin of production-promoting bond issuance causes exit while cheaper bank credit induces entry. When reducing transactions costs in one market, the resulting increase in output and welfare are largest when transactions costs in the other market are very high.Bond market ; Bank loans

Gauge invariance in the presence of a cutoff

We use the method of gauging equations to construct the electromagnetic current operator for the two-nucleon system in a theory with a finite cutoff. The employed formulation ensures that the two-nucleon T-matrix and corresponding five-point function, in the cutoff theory, are identical to the ones formally defined by a reference theory without a cutoff. A feature of our approach is that it effectively introduces a cutoff into the reference theory in a way that maintains the long-range part of the exchange current operator; for applications to effective field theory (EFT), this property is usually sufficient to guarantee the predictive power of the resulting cutoff theory. In addition, our approach leads to Ward-Takahashi (WT) identities that are linear in the interactions. From the point of view of EFT's where such a WT identity is satisfied in the reference theory, this ensures that gauge invariance in the cutoff theory is maintained order by order in the expansion.Comment: 15 pages, 2 figure

A Theory of Banks, Bonds, and the Distribution of Firm Size

We draw on stylized facts from the finance literature to build a model where altering the relative costs of bank and bond financing changes the entire distribution of firm size, with implications for the aggregate capital stock, output, and welfare. Reducing transactions costs in the bond market increases the output and profits of mid-sized firms at the expense of both the largest and smallest firms. In contrast, reducing the frictions involved in bank lending promotes the expansion of the smallest firms while all other firms shrink, even as it increases the profitability of both small and mid-size firms. Although both policies increase aggregate output and welfare, they have opposite effects on the extensive margin of production---promoting bond issuance causes exit while cheaper bank credit induces entry. When reducing transactions costs in one market, the resulting increase in output and welfare are largest when transactions costs in the other market are very high.

Financial Choice in a Non-Ricardian Model of Trade

We join the new trade theory with a model of choice between bank and bond financing to show the differential effects of financial policy on the distribution of firm size, welfare, aggregate output, gains from trade, and the real exchange rate in a small open economy. Increasing bank efficiency and reducing bond transaction costs both increase welfare but have opposite effects on the extensive margin of trade, aggregate exports, and the real exchange rate. Increasing the degree of trade openness increases firms' relative demand for bond versus bank financing. We identify a financial switching channel for gains from trade where increasing access to export markets allows firms to overcome high fixed costs of bond issuance to secure a lower marginal cost of capital.

Impact of functional group types in ion exchange resins on rare earth element recovery from treated acid mine waters

Ion-exchange (IX) resins incorporating single functional groups (sulfonic or amino-phosphonic) and two functional groups (sulfonic and phosphonic) were evaluated for selective recovery of Rare Earth Elements (REEs) from acidic mine waters (AMW). The composition of AMW solution, complexing properties of the functional group, and acidity were investigated as key parameters for concentration and separation of REEs from transition elements (TEs). Fe has to be removed from AMW to enable REE recovery and here the AMW was treated with NaOH solutions to reach pH 3.9 where Fe(III) was selectively removed (≤99%) by precipitation of schwertmannite. Single functional IX resin containing a sulfonic group displayed a higher REE recovery efficiency and separation ratio than observed for the bi-functional resin (sulfonic/phosphonic). Concentration factors for REEs between 30 and 40 were achieved using regeneration cycles with H2SO4. The performance of the aminophosphonic resin showed lower separation factors for REEs from TEs than the two resins containing sulfonic groups. IX resins performance was improved by tuning the acidity to match the functional group reactivity, where pH adjustment to the range of 0.5-2.0 provided the highest REE/TE separation factor for the single sulfonic resin followed by the bifunctional resin. The integration of an elution cycle using Na2-EDTA/NH4Cl mixtures strongly increases the concentration factors of REE and Light REE (LREE) concentration factors of up to 260 were achieved for the single functional sulfonic resin

CONCORDANCIA ENTRE ECOCARDIOGRAFÍA PRENATAL Y POSNATAL EN PACIENTES CON CARDIOPATÍAS CONGÉNITAS: HOSPITAL DE NIÑOS DR. ROBERTO DEL RÍO

Antecedentes: En Chile las malformaciones congénitas son la primera causa de mortalidad neonatal precoz, siendo las cardiopatías congénitas su principal factor. La incorporación de la ecocardiografía prenatal es de gran ayuda en su pesquisa precoz. Objetivos: Evaluar la ecocardiografía prenatal como prueba diagnóstica y su concordancia con la ecocardiografía posnatal. Métodos: Se analizaron embarazadas derivadas al Hospital de Niños Dr. Roberto del Río entre abril 2004 y abril 2008, por sospecha de cardiopatías congénitas con posterior control neonatal. Resultados: Se evaluaron 188 embarazadas tanto con diagnóstico de cardiopatía congénita como con ecocardiografía normal. La edad gestacional promedio de derivación fue de 32 semanas, siendo la principal causa la sospecha de cardiopatía congénita en el examen obstétrico de rutina. Como prueba diagnóstica se obtuvo una sensibilidad de 100% y especificidad de 40% con una moderada concordancia entre ésta y el examen postnatal. Como prueba diagnóstica la ecocardiografía prenatal, se obtuvo una sensibilidad de 100% y especificidad de 89% del examen, al ser evaluada como cardiopatías en general, con una muy buena concordancia entre ésta y el examen postnatal. Discusión: Existe una tardía derivación y diagnóstico prenatal de las cardiopatías congénitas a nivel nacional, siendo importante capacitar aún más a los obstetras que realizan este tamizaje. La ecocardiografía prenatal realizada en nuestro centro por cardiólogos es una confiable herramienta diagnóstica con una muy buena concordancia con la ecocardiografía posnatal

Estudio de soluciones metálicas. (i) aplicabilidad y limitaciones de algunos modelos termodinámicos

Se presentan y analizan las características centrales de los modelos termodinámicos energéticos basados en la interacción por pares entre un átomo y sus próximos vecinos. Se discute la aplicabilidad de estos modelos a sistemas metálicos binarios. Se concluye sugiriendo posibles alternativas para el refinamiento de estos modelos