Medio ambiente y minería: métodos modernos de beneficio del oro

Incluye Bibliografía

Competitividad e incorporación del progreso técnico en la minería de oro y cobre

Incluye Bibliografía

Circulando en el laberinto: la economía política de la salida del patrón oro en la Argentina (1929-1933)

Este artículo es la pequeña, pero crucial historia de un régimen cambiario-monetario en tránsito durante cuatro años, que culminó en 1933 con la desaparición definitiva del patrón oro en la Argentina. Ese proceso se caracterizó por decisiones tomadas en coyunturas críticas frente a las cuales las autoridades de gobierno no podían andar pausadamente, ante las cuales no tenían un arsenal analítico, ni certezas técnicas, ni convicciones políticas. El objetivo de este estudio es analizar esas “decisiones” a lo largo de siete hitos, siendo el primero el shock externo de 1929 y el último el envío al Congreso de una ley para la creación del banco central y un régimen de control de cambios caracterizado por tipos de cambio múltiples. El nuevo régimen implícito en ese reordenamiento de la economía argentina habría de perdurar, con sus idas y venidas, por al menos un cuarto de siglo.

A recriação do siglo de oro espanhol em El Capitán Alatriste, de Arturo Pérez-Reverte

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Isolation and molecular identification of Fusobacterium nucleatum from Nigerian patients with oro-facial infections.

Fusobacterium nucleatum is one of the most common anaerobic bacteria present in the oral cavity and is often isolated from infections involving other body sites. To characterise F. nucleatum strains from patients attending a teaching hospital in Nigeria in order to provide information on the methods for accurate identification of anaerobes in clinical specimen. Fusobacterium nucleatum specie from 50 patients presenting with oro-facial infections were studied by culture on Fusobacterium selective agar and fastidious anaerobe agar. The isolates were characterised based on colonial morphology, microscopy, lipase production, susceptibility to kanamycin and colistin and resistance to vancomycin. Biochemical tests were performed using a commercial test kit. The identity of the isolates was confirmed based on molecular characterization performed using polymerase chain reaction (PCR) analysis. Forty-eight (96%) F. nucleatum isolates were obtained from the 50 patients by culture and all the isolates were identified by colonial appearance and microscopy based on their unique spindle shape with tapered ends. Only 26 (54.2%) of the 48 isolates were identified by commercial API 20A test kit while PCR confirmed the identity of all the isolates. Anaerobes are involved in human infections and their study is quite cumbersome due to tedious nature and high cost of the techniques involved. Cultural method is reliable in the isolation and identification of F. nucleatum species. PCR is a rapid and simple method that can complement the phenotypic identification of anaerobes and would assist in their full identification.

Validity of the 'protocol of oro-facial myofunctional evaluation with scores' for young and adult subjects

The aims of this study were to analyse the validity, sensitivity and specificity of the protocol of oro-facial myofunctional evaluation with scores (OMES) for oro-facial myofunctional disorder (OMD) diagnosis in young and adult subjects. Eighty subjects were examined. The OMES was validated against the Nordic Orofacial Test-Screening (NOT-S) protocol (criterion validity) (Spearman correlation test). The construct validity was tested by analysis of the ability of the OMES (i) to differentiate healthy subjects (n = 22) from temporomandibular disorder (TMD) patients (n = 22), which frequently have OMD (MannWhitney test) and (ii) to measure the changes that occurred in a subgroup with TMD between the period before and after oro-facial myofunctional therapy (T group, n = 15) (Wilcoxon test). Two speech therapists trained with the OMES participated as examiners (E). There was a statistically significant correlation between the OMES and NOT-S protocols, which was negative because the two scales are inverse (r = -0.86, P < 0.01). There was a significant difference between the healthy and TMD subjects regarding the oro-facial myofunctional status (OMES total score, P = 0.003). After therapy, the T group showed improvement in the oro-facial myofunctional status (OMES total score, P = 0.001). Inter- and intra-examiner agreement was moderate, and the reliability coefficients ranged from good to excellent. The OMES protocol presented mean sensitivity and specificity = 0.80, positive predictive value = 0.76 and negative predictive value = 0.84. Conclusion: The OMES protocol is valid and reliable for clinical evaluation of young and adult subjects, among them patients with TMD.

Estudio de fronteras de grano en hidroxiapatita de origen natural mediante difracción de electrones

Programa de doctorado en Física fundamental y aplicada.

Valutazione delle Relazioni tra la Qualita’ del Grano duro e i Contratti di Coltivazione

La tesi riguarda le possibili connessioni tra la diffusione dei contratti di coltivazione(con disciplinari di coltivazione)e l'aumento della qualità del prodotto. Si basa su un indagine svolta intervistando con un questionario un campione di circa dieci aziende agricole. A tale proposito si cerca di capire quali aziende hanno sottoscritto dei contratti e, successivamente, si chiede agli intervistati un giudizio sulle prescrizioni contenute nei disciplinari di coltivazione. In base hai dati raccolti non si evidenziano aumenti sensibili della qualità connessi alla sottoscrizione di contratti di coltivazione.