Equilibrium and nonequilibrium fluctuations at the interface between two fluid phases

We have performed small-angle light-scattering measurements of the static structure factor of a critical binary mixture undergoing diffusive partial remixing. An uncommon scattering geometry integrates the structure factor over the sample thickness, allowing different regions of the concentration profile to be probed simultaneously. Our experiment shows the existence of interface capillary waves throughout the macroscopic evolution to an equilibrium interface, and allows to derive the time evolution of surface tension. Interfacial properties are shown to attain their equilibrium values quickly compared to the system's macroscopic equilibration time.Comment: 10 pages, 5 figures, submitted to PR

Real-Time Wavelet-transform spectrum analyzer for the investigation of 1/f^\alpha noise

A wavelet transform spectrum analyzer operating in real time within the frequency range 3X10^(-5) - 1.3X10^5 Hz has been implemented on a low-cost Digital Signal Processing board operating at 150MHz. The wavelet decomposition of the signal allows to efficiently process non-stationary signals dominated by large amplitude events fairly well localized in time, thus providing the natural tool to analyze processes characterized by 1/f^alpha power spectrum. The parallel architecture of the DSP allows the real-time processing of the wavelet transform of the signal sampled at 0.3MHz. The bandwidth is about 220dB, almost ten decades. The power spectrum of the scattered intensity is processed in real time from the mean square value of the wavelet coefficients within each frequency band. The performances of the spectrum analyzer have been investigated by performing Dynamic Light Scattering experiments on colloidal suspensions and by comparing the measured spectra with the correlation functions data obtained with a traditional multi tau correlator. In order to asses the potentialities of the spectrum analyzer in the investigation of processes involving a wide range of timescales, we have performed measurements on a model system where fluctuations in the scattered intensities are generated by the number fluctuations in a dilute colloidal suspension illuminated by a wide beam. This system is characterized by a power-law spectrum with exponent -3/2 in the scattered intensity fluctuations. The spectrum analyzer allows to recover the power spectrum with a dynamic range spanning about 8 decades. The advantages of wavelet analysis versus correlation analysis in the investigation of processes characterized by a wide distribution of time scales and non-stationary processes are briefly discussed.Comment: 12 pages, 6 figure

Clinical use of Levofloxacin in the long-term treatment of drug resistant tuberculosis.

Multidrug-resistant (MDR) tuberculosis (TB) is a form of TB that is resistant to some of the first-line drugs used for the treatment of the disease. It is associated both with a higher incidence of treatment failures and of disease recurrence, as well as with higher mortality than forms of TB sensitive to first-line drugs. Levofloxacin (LFX) represents one of the few second-line drugs recently introduced in the therapeutic regimens for MDR TB. We report our experience concerning in vitro activity and clinical safety of LFX in long term second-line regimens for MDR TB. IN VITRO ACTIVITY ON MYCOBACTERIA: The in vitro activity of ciprofloxacin, ofloxacin and LFX was studied on 28 strains belonging to different species of Mycobacteria. In Dubos medium, LFX inhibited the growth of both library and MDR clinical Mycobacteria strains in a range of 0.25-1 mcg/ml. In International Union Tuberculosis Medium (IUTM) the minimum inhibitory concentrations (MIC) were slightly higher, but LFX activity was not affected by the higher complexity of the medium. CLINICAL EXPERIENCE: Four patients with MDR TB were treated with a second-line regimen comprising oral LFX 500 mg twice daily, for at least 9 months. Two isolates obtained from the patients reported here showed multi resistance to isoniazid and rifampin, one to rifampin and streptomycin and one to isoniazid and ethambutol. During therapy, no significant alteration of either liver function tests, blood tests or any other described side effect of the fluoroquinolone class was observed. The 3 patients with pulmonary MDR TB showed radiologic and clinical improvement. CONCLUSION: We confirm the higher in vitro activity of LFX compared to older fluoroquinolones. Furthermore, in a limited number of MDR TB patients, second-line regimens comprising LFX 500 mg b.i.d. administered in a range of 9-24 months were well tolerated and safe

Predicción del desempeño en el contexto de las fuerzas de seguridad pública: un estado del arte

Introducción: El estudio de los factores predictivos del éxito en el desempeño de las fuerzas de seguridad pública resulta un tema muy relevante no solo para las instituciones de formación de los candidatos sino también para la sociedad. Específicamente, un correcto abordaje de los procesos de admisión y reclutamiento de los mejores candidatos para el puesto de gendarme requiere en primer lugar, de una exhaustiva revisión de los estudios más recientes sobre la temática. Objetivo: Realizar una revisión sistemática de la literatura científica sobre estudios recientes que aporten evidencia acerca de la predicción del desempeño en fuerzas de seguridad pública. Método: Se utilizaron bases de datos como Google Académico, PsyInfo y ResearchGate, introduciendo los siguientes términos de búsqueda tanto en inglés como en español: perfil del buen gendarme, military accession, armed forces prediction, predicción de desempeño en gendarmería, personnel selection, military personnel selection, predictores del rendimiento militar, rendimiento militar, military performance prediction, psicología militar, military psychology. Debido a que se hallaron muy pocos estudios recientes se decidió extender la búsqueda bibliográfica a los últimos 20 años. De esta manera, resultaron un total de 100 trabajos relevantes para la temática abordada. La primera lectura de los resúmenes permitió seleccionar aquellas investigaciones que se focalizaban específicamente en los predictores del buen rendimiento en ámbitos de seguridad pública, incluyéndose en la revisión final el análisis de 8 trabajos científicos. Resultados: Las variables que suelen utilizarse para la predicción del buen rendimiento en estos ámbitos se relacionan, en la mayoría de los casos, con medidas de personalidad y cognitivas. En este sentido, existe concordancia respecto a que la posesión por parte del individuo de ciertos patrones de personalidad, así como determinadas habilidades cognitivas de resolución de problemas pueden reflejar la capacidad de adaptarse a la vida militar de forma exitosa, prediciendo el correcto desempeño de las tareas. En cuanto a las características cognitivas analizadas en el perfil de un individuo, suelen utilizarse baterías de preguntas relacionadas con habilidades y conocimientos cognitivos (comprensión de lectura, razonamiento lógico, conocimiento sobre vocabulario, conocimiento implícito, inteligencia analítica y práctica). La medición de rasgos de la personalidad de los individuos involucrados se utiliza para predecir el desempeño. Respecto a las características personales más destacables para la predicción del éxito en el desarrollo de tareas militares, se mencionan la dominancia y el control. Un último aspecto que también es considerado al predecir el futuro desempeño de los individuos en tareas militares se relaciona con los logros educativos previos a entrar en la institución, así como los logros y el rendimiento como estudiante en la institución. Discusión: Existe un consenso general en cuanto a la importancia del conocimiento implícito y la práctica adquiridos en la formación académica como predictores del desempeño en fuerzas de seguridad pública. Por otro lado, algunos autores han encontrado correlaciones superiores entre la inteligencia analítica y la práctica, comparadas con las expuestas por otros estudios, que dan cuenta de asociaciones más débiles. En cuanto a las mediciones de características de la personalidad, existen instituciones que les otorgan un menor rango de relevancia frente a las cognitivas.Fil: Fuentes Cuiñas, Ana Alejandra. Universidad Argentina de la Empresa; ArgentinaFil: Vailati, P. A.. Universidad Argentina de la Empresa; ArgentinaFil: Musso, Mariel Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Centro Interdisciplinario de Investigaciones en Psicología Matemática y Experimental Dr. Horacio J. A. Rimoldi; Argentina. Universidad Argentina de la Empresa; ArgentinaXVII Reunión Nacional y VI Encuentro Internacional de la Asociación Argentina de Ciencias del ComportamientoPosadasArgentinaAsociación Argentina de Ciencias del Comportamient

Photoprotection in intact cells of photosynthetic bacteria: quenching of bacteriochlorophyll fluorescence by carotenoid triplets.

Upon high light excitation in photosynthetic bacteria, various triplet states of pigments can accumulate leading to harmful effects. Here, the generation and lifetime of flash-induced carotenoid triplets (3Car) have been studied by observation of the quenching of bacteriochlorophyll (BChl) fluorescence in different strains of photosynthetic bacteria including Rvx. gelatinosus (anaerobic and semianaerobic), Rsp. rubrum, Thio. roseopersicina, Rba. sphaeroides 2.4.1 and carotenoid- and cytochrome-deficient mutants Rba. sphaeroides Ga, R-26, and cycA, respectively. The following results were obtained: (1) 3Car quenching is observed during and not exclusively after the photochemical rise of the fluorescence yield of BChl indicating that the charge separation in the reaction center (RC) and the carotenoid triplet formation are not consecutive but parallel processes. (2) The photoprotective function of 3Car is not limited to the RC only and can be described by a model in which the carotenoids are distributed in the lake of the BChl pigments. (3) The observed lifetime of 3Car in intact cells is the weighted average of the lifetimes of the carotenoids with various numbers of conjugated double bonds in the bacterial strain. (4) The lifetime of 3Car measured in the light is significantly shorter (1-2 mus) than that measured in the dark (2-10 mus). The difference reveals the importance of the dynamics of 3Car before relaxation. The results will be discussed not only in terms of energy levels of the 3Car but also in terms of the kinetics of transitions among different sublevels in the excited triplet state of the carotenoid

Endoscopic removal of a right main bronchus glomus tumor

Glomus tumours in the respiratory tract are very rare. The majority of the reported cases have been surgically treated. An approach with rigid bronchoscopy to endobronchial lesions suspected to be carcinoid or other well vascularized tumours, as glomus tumor is, should be considered because it can allow a safe diagnosis and eventually be therapeutic avoiding more invasive and surgical procedures

Endoscopic removal of a right main bronchus glomus tumor

Glomus tumours in the respiratory tract are very rare. The majority of the reported cases have been surgically treated. An approach with rigid bronchoscopy to endobronchial lesions suspected to be carcinoid or other well vascularized tumours, as glomus tumor is, should be considered because it can allow a safe diagnosis and eventually be therapeutic avoiding more invasive and surgical procedures

EasyPrimer: user-friendly tool for pan-PCR/HRM primers design. Development of an HRM protocol on wzi gene for fast Klebsiella pneumoniae typing

In this work we present EasyPrimer, a user-friendly online tool developed to assist pan-PCR and High Resolution Melting (HRM) primer design. The tool finds the most suitable regions for primer design in a gene alignment and returns a clear graphical representation of their positions on the consensus sequence. EasyPrimer is particularly useful in difficult contexts, e.g. on gene alignments of hundreds of sequences and/or on highly variable genes. HRM analysis is an emerging method for fast and cost saving bacterial typing and an HRM scheme of six primer pairs on five Multi-Locus Sequence Type (MLST) genes is already available for Klebsiella pneumoniae. We validated the tool designing a scheme of two HRM primer pairs on the hypervariable gene wzi of Klebsiella pneumoniae and compared the two schemes. The wzi scheme resulted to have a discriminatory power comparable to the HRM MLST scheme, using only one third of primer pairs. Then we successfully used the wzi HRM primer scheme to reconstruct a Klebsiella pneumoniae nosocomial outbreak in few hours. The use of hypervariable genes reduces the number of HRM primer pairs required for bacterial typing allowing to perform cost saving, large-scale surveillance programs

The effect of calving in the summer on the hepatic transcriptome of Holstein cows during the peripartal period

The liver is the main metabolic organ coordinating the adaptations that take place during the peripartal period of dairy cows. A successful transition into lactation, rather than management practices alone, depends on environmental factors such as temperature, season of parturition, and photoperiod. Therefore, we analyzed the effect of calving season on the hepatic transcriptome of dairy cows during the transition period. A total of 12 Holstein dairy cows were assigned into 2 groups based on calving season (6 cows March-April, spring; 6 cows June-July, summer, SU). The RNA was extracted from liver samples obtained at -30, 3, and 35 DIM via percutaneous biopsy and hybridized to the Agilent 44K Bovine (V2) Gene Expression Microarray (Agilent Technologies Inc., Santa Clara, CA). A quantitative PCR on 22 target genes was performed to verify and expand the analyses. A total of 4,307 differentially expressed genes were detected (false discovery rate ≤0.05) in SU compared with spring. Furthermore, 73 unique differentially expressed genes were detected in SU compared with spring cows after applying a fold-change threshold ≥3 and ≤-3. For Kyoto Encyclopedia of Genes and Genomes pathways analysis of differentially expressed genes, we used the dynamic impact approach. Ingenuity Pathway Analysis software was used to analyze upstream transcription regulators and perform gene network analysis. Among metabolic pathways, energy metabolism from lipids, carbohydrates, and amino acids was strongly affected by calving in SU, with a reduced level of fatty acid synthesis, oxidation, re-esterification, and synthesis of lipoproteins, leading to hepatic lipidosis. Glycan-synthesis was downregulated in SU cows probably as a mechanism to counteract the progression of this lipidosis. In contrast, calving in the SU resulted in upregulation of gluconeogenesis but also greater use of glucose as an energy source. Among nonmetabolic pathways, the heat-shock response was obviously activated in SU cows but was also associated with inflammatory and intracellular stress response. Furthermore, data support a recent finding that cows experience endoplasmic reticulum stress around parturition. Transcription regulator analysis revealed how metabolic changes are related to important regulatory mechanisms, including epigenetic modification. The holistic analyses of the liver transcriptome response to calving in the summer at high environmental temperatures underscore how transition cows should be carefully managed during this period, as they experience alterations in liver energy metabolism and inflammatory state increasing susceptibility to health disorders in early postpartum