Nonparametric Estimation of Convergence of Interest Rates: Effects on Bond Pricing

We present and estimate a model of short term interest rate dynamics where we incorporate the convergent behavior of interest rates implied by the transition to EMU. We apply this model to data of two EMU countries -Spain and Italy- and compare the performance, in terms of accuracy of bond pricing, of this two-factor convergence model with alternative specifications. Nonparametric techniques are used for the estimation of the processes. The two-factor model which accounts for the convergence with Europe of the domestic economies, obtains better results than alternative models mainly for short-term assets. The results of the nonparametric specifications are shown to be significantly better than those of parametric alternatives.

Statistical trends in culture methods of endolithic bacteria extracted from Quartz, K-Feldspar (Jurassic) and Calcite (Quaternary) in semi-arid areas in Colombia

Microbial endolithic communities are ubiquitous in many deserts around the globe. They have been found in many different lithologies, including quartz, plagioclase and calcite. The use of culture methods in geomicrobiology is important because most bacteria are non-cultivable, which makes it very difficult to characterize and describe them. In this study, endolithic bacteria and yeast were cultured in three rock-forming minerals (quartz, K-feldspar and calcite) with standard culture methodologies. It was demonstrated that these endolithic microorganisms could grow in noble agar enriched with a mineral different from the one they were extracted. Microbes were also cultured in a nutritive broth under some physicochemical factors (sugar, salt, pH and temperature) to study their possible tolerance to different ecological conditions. These results were combined with Multiple Factorial Analysis to identify statistical trends between their morphologies (pigment, size and Gram stain), chemical elements and their tolerance to physicochemical factors. Our results show that it might exist a relationship between pigments in microbial colonies,their tolerance to pH9, salinity and temperature conditions; and that Gram-negative bacillus might have a high adaptive ability to different enriched minimum media. Characterizing microbial communities associated with lithic substrates in the laboratory could be helpful for future planning in the search for life on Mars

Elemental Characterization of Printing Inks and Strengthening the Evaluation of Forensic Glass Evidence

Improvements in printing technology have exacerbated the problem of document counterfeiting, prompting the need for analytical techniques that better characterize inks for forensic analysis. In this study, 319 printing inks (toner, inkjet, offset, and intaglio) were analyzed directly on the paper substrate using Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS) and Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS). As anticipated, the high sensitivity of LA-ICP-MS resulted in excellent discrimination (\u3e 99%) between ink samples originating from different sources. Moreover, LA-ICP-MS provided ≥ 90% correct association for ink samples originating from the same source. SEM-EDS resulted in good discrimination for toner and intaglio inks (\u3e 97%) and excellent correct association (100%) for all four ink types. However, the technique showed limited utility for the discrimination of inkjet and offset inks. A searchable ink database, the Forensic Ink Analysis and Comparison System (FIACS), was developed in order to provide a tool that allows the analyst to compare a questioned ink sample to a reference population. The FIACS database provided a correct classification rate of 94-100% for LA-ICP-MS and 67-100% for SEM-EDS. An important consideration in forensic chemistry is the interpretation of the evidence. Typically, a match criterion is used to compare the known and questioned sample. However, this approach suffers from several disadvantages, which can be overcome with an alternative approach: the likelihood ratio (LR). Two LA-ICP-MS glass databases were used to evaluate the performance of the LR: a vehicle windshield database (420 samples) and a casework database (385 samples). Compared to the match criterion, the likelihood ratio led to improved false exclusion rates (\u3c 1.5%) and similar false inclusion rates (\u3c 1.0%). In addition, the LR limited the magnitude of the misleading evidence, providing only weak support for the incorrect proposition. The likelihood ratio was also tested through an inter-laboratory study including 10 LA-ICP-MS participants. Good correct association rates (94-100%) were obtained for same-source samples for all three inter-laboratory exercises. Moreover, the LR showed a strong support for an association. Finally, all different-source samples were correctly excluded with the LR, resulting in no false inclusions

Comparison of piezoimplants versus conventional cylindrical implants in minipigs: stability analysis

AIM: To compare the stability of a non-cylindrical implant using piezoelectric drilling (Piezoimplant) with a cylindrical implant with conventional drilling (Nobel Biocare™). MATERIALS AND METHODS: Three adult female Gottingen miniature pigs were used for the surgical implantation. Three implants on each quadrant, randomized split-mouth design using cylindrical or non-cylindrical implants (n=36). Osteotomies were prepared using either conventional drilling technique as per manufacturer’s instruction (Nobel Biocare™) or using piezoelectric drilling (Piezotome® (P2) (Satelec Acteon, Merignac, France) with new implant prototype tips (Fraunhofer Center for Manufacturing Innovation). The minipigs were sacrificed at 4, 8 and 12-weeks. Stability tests (three per implant) using wireless Periotest® “M” were done at the start point and after euthanization. RESULTS: R-square (ANOVA) test was plotted comparing implant design, weeks 4, 8 and 12, and location (mandible and maxilla) for stability analysis. In this model, the R-square is only 0.51, which indicates only 51% of the response variability can be explained by the fitted model. Among all the 3 factors, group (experiment vs control) is the most significant one, followed by week. Location significance is the least among the three factors. CONCLUSION: In mandibular and maxillary sites in minipigs where non-cylindrical prototype implants (piezoimplant) were inserted by piezoelectric site preparation, statistically significant differences were found between control and test group stability measurements, but no differences in week (4, 8 or 12) and location among the two groups (mandible and maxilla). Stability was like the cylindrical implants. Meaning that Piezoimplants could be an alternative for narrow residual ridges.2020-03-14T00:00:00

Generation of pulsed bipartite entanglement using four-wave mixing

Using four-wave mixing in a hot atomic vapor, we generate a pair of entangled twin beams in the microsecond pulsed regime near the D1 line of $^{85}$Rb, making it compatible with commonly used quantum memory techniques. The beams are generated in the bright and vacuum-squeezed regimes, requiring two separate methods of analysis, without and with local oscillators, respectively. We report a noise reduction of up to $3.8\pm 0.2$ dB below the standard quantum limit in the pulsed regime and a level of entanglement that violates an Einstein--Podolsky--Rosen inequality.Comment: 10 pages, 5 figures, accepted for publication in New Journal Of Physici

Trayectoria de los indicadores del Sistema Universitario Estatal y sus relaciones con el Modelo de los indicadores del Desempeño de la Educación Superior

Los indicadores de un Modelo de Gestión usado por el Ministerio de Educación para evaluar el desempeño y asignar recursos a las universidades públicas colombianas se encuentran publicadas para el periodo 2003 a 2012. Este modelo fue reemplazado en 2015 por el Modelo de Indicadores de Desempeño de Educación Superior (MIDE) que clasifica a las universidades públicas y privadas. Se analizan y describen las trayectorias de las universidades públicas en el periodo, a lo largo de tres factores latentes de evolución. Con estos se construyeron tres clases dinámicas, las cuales se distinguen entre sí porque las trayectorias de las universidades que las conforman son indicadores de su grado de desarrollo en el período. Después se construyen una tipologías o enfoques desarrollados por las universidades en el período, se reconstruyen empíricamente los enfoques del MIDE y se comparan y establecen cercanías entre estos. Los factores fueron construidos con Análisis de Componentes principales aplicados a una reestructura de la matriz de indicadores, cuyas coordenadas sobre los factores contienen información sobre las trayectorias y sobre las variables que la describen y facilita la representación gráfica de tales trayectorias. Los enfoques se reconstruyeron con un Análisis de Correspondencias sobre una tabla de Contingencias de Universidades por niveles de formació