Revisiting the Problem of Searching on a Line

We revisit the problem of searching for a target at an unknown location on a line when given upper and lower bounds on the distance D that separates the initial position of the searcher from the target. Prior to this work, only asymptotic bounds were known for the optimal competitive ratio achievable by any search strategy in the worst case. We present the first tight bounds on the exact optimal competitive ratio achievable, parameterized in terms of the given bounds on D, along with an optimal search strategy that achieves this competitive ratio. We prove that this optimal strategy is unique. We characterize the conditions under which an optimal strategy can be computed exactly and, when it cannot, we explain how numerical methods can be used efficiently. In addition, we answer several related open questions, including the maximal reach problem, and we discuss how to generalize these results to m rays, for any m >= 2

Análisis estadístico de los resultados obtenidos en la observación del programa S.R.S. con el Círculo Meridiano Repsold de 190 mm

Desde el l 9 de julio de 1969 al 31 de agosto de 1972 se observaron 6.842 estrellas para el Catálogo S.R.S. de las 7.190 que nos fueron asignadas y que cubren la zona de —40° a —90° de Declinación. Como cada estrella S.R.S. es observada al menos dos veces, una en cada posición del instrumento, pensamos que la discrepancia de los valores obtenidos en una y otra posición, tanto en Ascensión Recta como en Declinación, podía ser un buen índice para evaluar la bondad del trabajo realizado y comportamiento del instrumento.Asociación Argentina de Astronomí

Susceptibility of adults of the cerambycid beetle Hedypathes betulinus to the entomopathogenic fungi Beauveria bassiana, Metarhizium anisopliae, and Purpureocillium lilacinum

Fil: Schapovaloff, M.E.. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios en Parasitología y Vectores; ArgentinaFil: Alves, L.F.A.. Universidade Estadual do Oeste do Paraná. Laboratório de Biotecnologia Agrícola; BrasilFil: Fanti, A.L.. Universidade Estadual do Oeste do Paraná. Laboratório de Biotecnologia Agrícola; BrasilFil: Alzogaray, R.A.. Centro de Investigaciones de Plagas e Insecticidas; ArgentinaFil: López Lastra, Claudia Cristina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios en Parasitología y Vectores; Argentin

Resultados de las observaciones con Círculo Meridiano en San Juan

The analysis of 198 series of FK4 stars observed with the Repsold Meridian Circle at San Juan, Argentina, shows similar results with those obtained by the Danjon Astrolabe at San Juan and others for the systematic errors of the FK4 in the Southern Hemisphere.Asociación Argentina de Astronomí

Resultados de las observaciones con Círculo Meridiano en San Juan

The analysis of 198 series of FK4 stars observed with the Repsold Meridian Circle at San Juan, Argentina, shows similar results with those obtained by the Danjon Astrolabe at San Juan and others for the systematic errors of the FK4 in the Southern Hemisphere.Asociación Argentina de Astronomí

Resultados de las observaciones con Círculo Meridiano en San Juan

The analysis of 198 series of FK4 stars observed with the Repsold Meridian Circle at San Juan, Argentina, shows similar results with those obtained by the Danjon Astrolabe at San Juan and others for the systematic errors of the FK4 in the Southern Hemisphere.Asociación Argentina de Astronomí

Effect of two mouthwashes on salivary PH.

To analyze the effect of two mouthwashes on salivary pH and correlate it with age, buffer capacity and saliva flow rate in healthy volunteers, a crossover phase IV clinical study involving three age-based groups was designed. Two commercial mouthwashes (MW), Cool Mint Listerine® (MWa) and Periobacter ® (MWb) were used. The unstimulated saliva of each individual was first characterized by measuring flow rate, pH, and buffer capacity. Salivary pH was evaluated before rinsing with a given MW, immediately after rinsing, 5 minutes later, and then every 10 min (at 15, 25, 35 min) until the baseline pH was recovered. Paired t-test, ANOVA with a randomized block design, and Pearson correlation tests were used. Averages were 0.63 mL/min, 7.06, and 0.87 for flow rate, pH, and buffer capacity, respectively. An immediate significant increase in salivary pH was observed after rinsing, reaching average values of 7.24(MWb) and 7.30 (MWa), which declined to an almost stable value 15minutes. The great increase in salivary pH, after MW use shows that saliva is a dynamic system, and that the organism is capable of responding to a stimulus with changes in its composition. It is thus evident that pH of the external agent alone is not a good indicator for its erosive potential because biological systems tend to neutralize it. The results of this study enhance the importance of in vivo measurements and reinforce the concept of the protective action of saliva.publishedVersio

High prevalence and diversity of extended-spectrum β-lactamase and emergence of OXA-48 producing Enterobacterales in wildlife in Catalonia

The contract of LMG was supported by the Instituto Nacional de Investigaci?n y Tecnolog?a Agraria y Alimentaria (INIA) and the European Social Fund. AV was supported by a PIF grant from the Universitat Aut?noma de Barcelona. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Our grateful thanks to the Torreferrussa WRC staff. A.C. was student of the Master?s Degree in Zoonosis and One Health (UAB). The authors are also grateful to the Centres de Recerca de Catalunya (CERCA) Programme.Most of the studies focused on antimicrobial resistance (AMR) performed in wildlife describe Escherichia coli as the principal indicator of the selective pressure. In the present study, several species of Enterobacterales with a large panel of cephalosporin resistant (CR) genes have been isolated from wildlife in Catalonia. A total of 307 wild animals were examined to determine the prevalence of CR enterobacteria, AMR phenotypes and the presence of common carbapenem and CR genes. The overall prevalence of CR-phenotype was 13% (40/ 307): 17.3% in wild mammals (18/104) and 11.5% in wild birds (22/191) (p<0.01). Hedgehogs showed the highest prevalence (13.5% of 104) of the mammal specimens, and raptors the highest in bird specimen (7.3% of 191). Although CR E. coli was the most frequently isolated (45%), other CR- Enterobacterales like Klebsiella pneumoniae (20%), Citrobacter freundii (15%), Enterobacter cloacae (5%), Proteus mirabilis (5%), Providencia spp (5%) and Serratia marcescens (2.5%) were also isolated. A high diversity of CR genes was identified among the isolates, with 50% yielding blaCMY-2, 23% blaSHV-12, 20% blaCMY-1 and 18% blaCTX-M-15. Additionally, resistance to carbapenems associated to OXA-48 gene was found. Most of the CR isolates, principally K. pneumoniae and C. freundii, were multiresistant with co-resistance to fluoroquinolones, tetracycline, sulphonamides and aminoglycosides. This study reports high prevalence of Enterobacterales harbouring a variety of CR genes and OXA-48 mediated-carbapenem resistance, all of them frequently associated to nosocomial human infections, for the first time in wild mammals and wild birds. Implementation of control measures to reduce the impact of anthropogenic pressure in the environment is urgently needed

Mortalidad por cáncer bucal en la provincia de Córdoba, República Argentina (período 1975-2000). Estudio comparativo con otras poblaciones.

A nivel mundial la mortalidad por neoplasias malignas (NM), figura entre las cuatro primeras causas de muerte en la década del 90 (1-4). El objetivo del presente trabajo, es estudiar la tasa de mortalidad por las ocho NM más frecuentes y especialmente por cáncer bucal (CB) en la provincia de Córdoba, República Argentina en el período 1975-2000, analizar sus características y compararla con la de otras poblaciones de América y Europa. Material y Métodos: los datos se obtuvieron del Ministerio de Salud de Córdoba y Argentina y de Globocan 2000. Resultados: en el sexo masculino se observó que los países con más alta tasa fueron Eslovaquia y Francia, siendo los Tumores más prevalentes los de pulmón y bronquios. En las mujeres el Reino Unido, Alemania y EEUU fueron los países con tasa más alta y el Tumor más frecuente fue el de mama, excepto en EEUU donde el de pulmón lo antecede. En relación al CB en las poblaciones estudiadas, Eslovaquia y Francia fueron los países con tasa más alta para ambos sexos, estando los valores de Córdoba y Argentina entre los más bajos, especialmente en mujeres. En Córdoba la lengua fue el sitio más frecuente (43,5%), seguido de glándulas salivales mayores (23,7%); predominó el sexo masculino y las edades promedio más altas se observaron en el período 1995-2000. Al analizar el comportamiento de las tasas de mortalidad se destacó que las NM en ambos sexos en Córdoba aumentaron el 6,6%, y la mortalidad por CB en mujeres se incrementó un 77% en el período estudiado. El CB es un serio problema de salud pública que causa gran morbilidad y mortalidad no habiendo mejorado en décadas. Las tasas de mortalidad son un instrumento importante para la diagramación de políticas y programas de salud orientados a la prevención del cáncer.publishedVersio

Nucleation kinetics of crystalline phases from a kaolinitic body used in the processing of red ceramics

The crystallization kinetics of red ceramic raw material from the western part of São Paulo State, Brazil, was examined by differential thermal analysis (DTA) and X-ray diffraction (XRD). The chemical composition of the clay sample was determined by X-ray fluorescence (XRF). Non-isothermal crystallization kinetic methods have been applied to the study of the mechanism of crystallization in this kaolinitic material. The exothermic peak shifted to higher temperatures (945 to 974 °C) with increasing heating rate (10 to 50 °C/min). The average activation energies determined by the Kissinger method (787 ± 85 kJ/mol) and the Ligero method (721 ± 32 kJ/mol) are in agreement. The Avrami constant n obtained by the Ligero method and the m parameter (Matusita method) values were between 1 and 1.5, which indicate a three-dimensional crystal growth with polyhedral morphology and surface nucleation as the dominant mechanism. X-ray diffraction data indicate that this activation energy is not associated with the crystallization of mullite. Scanning electron microscopy (SEM) images of fired (1000 and 1190 °C) samples show their densification during the sinterization process.The authors thank FUNDUNESP and FAPESP (2008/04368-4) for financial support of this work. We also are grateful to PROPE/UNESP/SANTANDER for Dr. Teixeira's post-doc scholarship in MadridPeer reviewe