Contrast Enhancement of Optical Coherence Tomography Images Using Branched Gold Nanoparticles

We propose the use of branched gold nanoparticles (B-GNPs) as a contrast agent for optical coherence tomography (OCT) imaging. Our results show that even when the central source of our OCT (1325 nm) is too far from the maximum peak of the plasmon resonance, branched nanoparticles scatter light very efficiently at this wavelength. B-GNPs were tested as a contrast agent in water and agarose-TiO2 tissue phantoms; the estimated increments in contrast were 9.19 dB and 15.07 dB for branched nanoparticles in water with concentrations of 2.2×109 NPs/mL and 6.6×109 NPs/mL, respectively, while for agarose-TiO2 tissue phantoms the estimated value was 3.17 dB. These results show the promising application of B-GNPs as a contrast agent for tissue imaging using OCT, not only for sources at 1325 nm but also at other central wavelengths located between 800 and 1000 nm

The biology and behavior of the longhorned beetle, Dectes texanus on sunflower and soybean

The biology and behavior of the longhorned beetle Dectes texanus LeConte (Coleoptera: Cerambycidae) was studied on two host plants that suffer economic losses from this pest; sunflower, Helianthus annuus, and soybean, Glycines max. Reciprocal crosses of D. texanus collected from the two plants all produced viable progeny, indicating that conspecific insects attack both crops. Pupae from soybean stalks weighed about 40% less than those from sunflower, and adults fed on soybean lived a mean of 23 days, compared to a mean of 53 days (males) and 76 days (females) for those fed sunflower. A female's larval host plant had no effect on her tendency to ovipuncture plants of either type in a greenhouse trial. A field-tested population collected exclusively from sunflower contained three types of females in similar proportions: those that laid eggs only on sunflower, those that laid only on soybean, and those that laid equally on both host plants. Females in field trials fed more on the plant they had fed on in the laboratory, but soybean-fed females fed more on soybean than did sunflower-fed females. Females fed soybean also made more ovipunctures on soybean plants in field trials than sunflower-fed females, but their responses to sunflower plants were similar. Females displayed higher total ovipositional activity when they encountered sunflower first in the field, and lower total activity when they encountered soybean first. Feeding scores were significantly correlated with ovipunctures and eggs on both plant types. We conclude that sunflower is the preferred host plant, although females will accept soybean when it is the only available food. The results suggest that D. texanus is still in the initial stages of a host range expansion with female host selection behavior demonstrating both genetic influences and phenotypic flexibility. Sunflower represents a nutritionally superior, ancestral host plant and relatively high fitness costs are still associated with utilization of the novel host plant, soybean, costs that may be offset by benefits such as reduced intraspecific competition. These potential benefits and their consequent implications for D. texanus host range evolution are hypothesized and discussed

Susceptibility of biological stages of the horn fly, Haematobia irritans, to entomopathogenic fungi (Hyphomycetes)

The susceptibility of the egg, pupa, and adult of Haematobia irritans (L.) (Diptera: Muscidae) to isolates of the fungi Metarhizium anisopliae (Metsch.) Sor., Beauveria bassiana (Bals.) Vuill., and Paecilomyces fumosoroseus (Wize) Brown and Smith, was evaluated under laboratory conditions. Groups of 20 eggs than 4 h old, pupae less than 48h old and adults were sprayed with a conidial suspension of each isolate. Eggs, pupae and adults of horn fly were susceptible to these entomopathogenic fungi. For treated eggs, the isolates Ma3, Ma 15, Ma25, Pfr1, and Pfr8 reduced adult emergence to 3.8% to 6.3% in comparison with the control (72%). The mortality of pupae infected by the isolates Ma2, Ma25, and Pfr10 ranged between 50% and 71.3%. Mortality of adults after treatment with the isolates Ma6, Ma 10, Ma 14, Ma 15, Pfr 1, Pfr 9, Pfr 10, Pfr 11, and Pfr12 were higher than 90%. The isolate Ma6 produced the lowest LC(50) against adult horn flies (8.08 &times 10(2)conidia/ml). These findings supported the hypotheses that isolates of M. anisopliae, and P. fumosoroseus are pathogenic against the different biological stages of horn flies by reducing adult emergence when applied on groups of eggs and pupae, and producing mortality when applied to adults

Natural Distribution of Parasitoids of Larvae of the Fall Armyworm, Spodoptera frugiperda, in Argentina

To develop a better understanding of the natural distribution of the fall armyworm, Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae), and to update the knowledge of the incidence of its complex of parasitoids. S. frugiperda, samplings in whorl-stage corn were carried out in provinces of Argentina from 1999 to 2003. S. frugiperda larvae were collected from corn in localities of the provinces of Tucumán, Salta, Jujuy, Santiago del Estero, La Rioja, Córdoba, San Luis, Chaco and Misiones. In each locality 30 corn plants were sampled and only larvae located in those plants were collected. The parasitoids that emerged from S. frugiperda larvae were identified and counted. The abundance of the parasitoids and the parasitism rate were estimated. The S. frugiperda parasitoids collected were Campoletis grioti (Blanchard) (Hymenoptera: Ichneumonidae), Chelonus insularis (Cresson) (Hymenoptera: Braconidae), Archytas marmoratus (Townsend) (Diptera Tachinidae) and/or A. incertus (Macquart), Ophion sp. (Hymenoptera: Ichneumonidae), Euplectrus platyhypenae Howard (Hymenoptera: Eulophidae), and Incamyia chilensis (Aldrich) (Diptera Tachinidae). C. grioti was the most abundant and frequent during the five-year survey. Similar diversity of parasitoids was obtained in all the provinces, with the exception of I. chilensis and E. platyhypenae that were recovered only in the province of Salta. In the Northwestern region, in Tucumán, C. grioti and species of Archytas were the most abundant and frequent parasitoids. On the contrary, in Salta and Jujuy Ch. insularis was the parasitoid most abundant and frequently recovered. The parasitism rate obtained in Tucumán, Salta and Jujuy provinces were 21.96%, 17.87% and 6.63% respectively with an average of 18.93%. These results demonstrate that hymenopteran and dipteran parasitoids of S. frugiperda occurred differentially throughout the Argentinian provinces and played an important role on the natural control of the S. frugiperda larval population

VOLUMEN 19, NÚMERO 34 (1990)

LAS GRANULITAS EN COLOMBIA. Gómez, J. A.ESTRUCTURAS Y DEFORMACIONES DE LOS SEDIMENTOS CRETÁCEOS DE LA FORMACIÓN ABEJORRAL, DEPARTAMENTO DE ANTIOQUIA, CORDILLERA CENTRAL. Kammer, A.PROSPECCIÓN GEOQUÍMICA DE SUELOS EN LOS ALREDEDORES DE LA QUEBRADA CHIRAPOTÓ. Ortiz, B. F.; Chamorro, G. M.ESTUDIO GEOLÓGICO DE UN YACIMIENTO DE Pb-Zn EN EL PARAJE LA X - TUTUNENDO (CHOCÓ). Molina, M. L.; Ochoa, Y. A.; Ortíz B. F.GEOLOGÍA Y PETROGRAFÍA DE FACIES CATACLÁSTICAS DE LA FORMACIÓN BARROSO E INTRUSIVOS Y METAMORFITAS ASOCIADOS EN CAÑAFISTO, ANTIOQUIA. Vargas, G.; Amaya, C

Simulation of risk of tuberculosis infection in healthcare workers in hospitals of an intermediate incidence country

We simulated the frequency of tuberculosis infection in healthcare workers in order to classify the risk of TB transmission for nine hospitals in Medellín, Colombia. We used a risk assessment approach to estimate the average number of infections in three risk groups of a cohort of 1082 workers exposed to potentially infectious patients over 10- and 20-day periods. The risk level of the hospitals was classified according to TB prevalence: two of the hospitals were ranked as being of very high priority, six as high priority and one as low priority. Consistent results were obtained when the simulation was validated in two hospitals by studying 408 healthcare workers using interferon gamma release assays and tuberculin skin testing. The latent infection prevalence using laboratory tests was 41% [95% confidence interval (CI) 34·3–47·7] and 44% (95% CI 36·4–51·0) in those hospitals, and in the simulation, it was 40·7% (95% CI 32·3–49·0) and 36% (95% CI 27·9–44·0), respectively. Simulation of risk may be useful as a tool to classify local and regional hospitals according to their risk of nosocomial TB transmission, and to facilitate the design of hospital infection control plans

VOLUMEN 19, NÚMERO 34 (1990)

LAS GRANULITAS EN COLOMBIA. Gómez, J. A.ESTRUCTURAS Y DEFORMACIONES DE LOS SEDIMENTOS CRETÁCEOS DE LA FORMACIÓN ABEJORRAL, DEPARTAMENTO DE ANTIOQUIA, CORDILLERA CENTRAL. Kammer, A.PROSPECCIÓN GEOQUÍMICA DE SUELOS EN LOS ALREDEDORES DE LA QUEBRADA CHIRAPOTÓ. Ortiz, B. F.; Chamorro, G. M.ESTUDIO GEOLÓGICO DE UN YACIMIENTO DE Pb-Zn EN EL PARAJE LA X - TUTUNENDO (CHOCÓ). Molina, M. L.; Ochoa, Y. A.; Ortíz B. F.GEOLOGÍA Y PETROGRAFÍA DE FACIES CATACLÁSTICAS DE LA FORMACIÓN BARROSO E INTRUSIVOS Y METAMORFITAS ASOCIADOS EN CAÑAFISTO, ANTIOQUIA. Vargas, G.; Amaya, C

Levels of quinolones resistance and other antimicrobial in non-pathogenic Escherichia coli strains in children from the periurban area of Lima, Peru

The main aim of this study was to establish the resistance levels to antimicrobial agents, in 222 non-pathogenic E. Coli strains of fecal origin in Peru. The proportion of resistance found to the evaluated antimicrobials was ampicillin (62.6%), cotrimoxazole (48,6%), tetracycline (43,0%) and chloramphenicol (15,8%). We emphasize the high resistance levels found for quinolones: 32% for nalidixic acid (NAL) and 12% for ciprofloxacin (CIP). These high levels of quinoloneresistance in non-pathogenic strains isolated from children in this age group highlight the extensive use and the impact of the intake of this kind of antimicrobials in the community, showing the potential risk of the loss of their utility in the area.Este trabajo fue parcialmente financiado por Agència Catalana de Cooperació al Desenvolupament proyecto U2006 (LJdV), Centre de Cooperació per al Desenvolupament - Universitat Politècnica de Catalunya (LJdV), Agencia Española de Cooperación Internacional al Desarrollo proyectos numero A/4892/06 (LJdV), D/019499/08 y D/024648/09 (JR), Fogarty International Center, National Institute of Health, USA, proyecto 1K01TW007405 (TJO) Sanofi Pasteur y fondos de investigación del Dr. Lanata, Instituto de Investigación Nutricional, Lima, Perú. La investigación de JR es financiado por el proyecto CP05/0130 del FIS (Fondo de Investigaciones Sanitarias, España).Revisión por pare

EFHC1 variants in juvenile myoclonic epilepsy: reanalysis according to NHGRI and ACMG guidelines for assigning disease causality

Peer reviewe