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Search Results: 1 - 10 of 67004 matches for " José; Tueros "
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Ciclo de vida y aspectos poblacionales de Edessa aff. aulacosterna Stal, 1872 (Heteroptera: Pentatomidae) chinche del fruto del camu camu (Myrtaceae) en zona de restinga, Ucayali, Perú
Iannacone, José;Perez, Diana;Tueros, Alfredo;
Acta Amazonica , 2007, DOI: 10.1590/S0044-59672007000400020
Abstract: camu camu is one of the native fruits with a great economic potential for agroindustry and agro exportation. edessa is one camu camu pest that produces in dry buds and fruits with a mark decolorated with concentric circles well marked and a central point when they feed. the aim of the current research was to determinate the biological cycle under laboratory conditions and population fluctuations of edessa aff. aulacosterna. "camu camu fruit stink bug" during january to november, 2004 in camu-camu culture, in development and production parcels located in flooded areas of restinga in pucallpa, ucayali, peru. eggs, nymphs and adults were colected to begin artificial rearing proceeding of distrit of yarinacocha, pucallpa, ucayali, peru. development time of eggs to 1th nymphal instar was 5.1 days. 94.6% of egg hatchability, varied between 12 until 14 egg-laying was found. the time passed since eggs until iii nymphal instar was 37.3 días and of iii to v nymphal instar was de 81.9 days. percentage of mortality of 2nd nymphal instar to adult was 98,1%. adults collected were localized mainly on branches and stem of the plants, while nymphs were found in delicated buds. in relation to seasonal populations only were registered eggs laying throught the year in parcels in production. differences between nymphs i to v and adults of edessa aff. aulacosterna, in production and development plantations were not found. only differences in dry and wet period in iii to v nymphs instar in development camu camu plants were found. edessa aff. aulacosterna mainly presented a contagious distribution. suitable knowledge of bioecology of edessa aff. aulacosterna permit improves strategy of pest control.
TOXICIDAD DE PAULLINIA CLAVIGERA SCHLTDL. (SAPINDACEAE) Y CHONDRODENDRON TOMENTOSUM RUIZ ET PAV. (MENISPERMACEAE) SOBRE EL PIOJO SALTADOR DEL CAMU CAMU TUTHILLIA COGNATA (HEMIPTERA: PSYLLIDAE)
Pérez,Diana; Iannacone,José; Tueros,Alfredo;
Gayana. Botánica , 2008, DOI: 10.4067/S0717-66432008000200004
Abstract: toxic effects of two hidro-alcoholical extracts belonging to two amazonian plants of ethnobotanical importance, soapberry paullinia clavigera schltdl. (sapindaceae) and curare chondrodendron tomentosum ruiz et pav. (menispermaceae), both in vegetative growing, on iii nymph instars of jumping lice of camu camu tuthillia cognata hodkinson, brown & burckhardt, 1986 (hemiptera: psyllidae) were determined. collection of nymphs of t. cognata was performed on plantations of san juan small town, yarinacocha district, ucayali, peru. bioassays were done employing a randomized completely block design (rcbd): 6x4. maceration of extracts were performed during seven days at a proportion 1:10 (w/v) with a posterior solvent evaporation in a rotavapor. toxic effect on t. cognata was evaluated at 1,4, 8,12 and 24 h. in soapberry lc50 24h was 2,530 mg extract l"1 and in curare lc50 24h was 4,090 mg extract l"1 on t. cognata. at a concentration of 10,000 mg extract l4,lt50 of soapberry and curare were 10.38 and 15.01 h, respectively. phytochemical analysis showed saponins, phenols, flavonoids, qui?ones and cumarins in soapberry extract, and alkaloids and saponins in curare extract. toxicity in lc50 terms depended of the extract type employed.
TOXICIDAD DE PAULLINIA CLAVIGERA SCHLTDL. (SAPINDACEAE) Y CHONDRODENDRON TOMENTOSUM RUIZ ET PAV. (MENISPERMACEAE) SOBRE EL PIOJO SALTADOR DEL CAMU CAMU TUTHILLIA COGNATA (HEMIPTERA: PSYLLIDAE) TOXICITY OF PAULLINIA CLAVIGERA SCHLTDL. (SAPINDACEAE) AND CHONDRODENDRON TOMENTOSUM RUIZ ET PAV. (MENISPERMACEAE) ON JUMPING LICE OF CAMU CAMU TUTHILLIA COGNATA (HEMIPTERA: PSYLLIDAE)
Diana Pérez,José Iannacone,Alfredo Tueros
Gayana. Botanica , 2008,
Abstract: Se determinó el efecto tóxico de dos extractos hidroalcohólicos procedentes de dos plantas amazónicas de importancia etnobotánica, Paullinia clavigera Schltdl. "sachayoco" (Sapindaceae) y Chondrodendron tomentosum Ruiz et Pav "curare" (Menispermaceae), ambas en desarrollo vegetativo, sobre ninfas del III estadio de Tuthillia cognata Hodkinson, Brown & Burckhardt, 1986 "piojo saltador del camu camu" (Hemiptera: Psyllidae). Las ninfas de T. cognata se colectaron en plantaciones del caserío San Juan en el distrito de Yarinacocha, Ucayali, Perú. Los bioensayos se realizaron empleando un Dise o de Bloque Completo al Azar (DBCA): 6x4. Los extractos se maceraron durante siete días a una proporción 1:10 (p/v) con posterior evaporación del solvente en rotavapor. El efecto tóxico se evaluó a 1, 4, 8, 12 y 24 h sobre T. cognata. En sachayoco se obtuvo una CL50_24h de 2.530 mg de extracto L"1 y en curare una CL50_24h de 4.090 mg de extracto L"1 sobre T. cognata. Auna concentración de 10.000 mg de extracto L"1, se determinó el TL50 del sachayoco y del curare a las 10,38 y 15,01 h, respectivamente. El análisis fitoquímico reveló saponinas, fenoles, flavonoides, quinonas y cumarinas en el extracto de sachayoco, así como alcaloides y saponinas en el extracto de curare. La toxicidad en términos de la CL50 dependió del tipo de extracto empleado. Toxic effects of two hidro-alcoholical extracts belonging to two Amazonian plants of ethnobotanical importance, soapberry Paullinia clavigera Schltdl. (Sapindaceae) and curare Chondrodendron tomentosum Ruiz et Pav. (Menispermaceae), both in vegetative growing, on III nymph instars of jumping lice of camu camu Tuthillia cognata Hodkinson, Brown & Burckhardt, 1986 (Hemiptera: Psyllidae) were determined. Collection of nymphs of T. cognata was performed on plantations of San Juan small town, Yarinacocha district, Ucayali, Peru. Bioassays were done employing a randomized completely block design (RCBD): 6x4. Maceration of extracts were performed during seven days at a proportion 1:10 (w/v) with a posterior solvent evaporation in a rotavapor. Toxic effect on T. cognata was evaluated at 1,4, 8,12 and 24 h. In soapberry LC50 24h was 2,530 mg extract L"1 and in curare LC50 24h was 4,090 mg extract L"1 on T. cognata. At a concentration of 10,000 mg extract L4,LT50 of soapberry and curare were 10.38 and 15.01 h, respectively. Phytochemical analysis showed saponins, phenols, flavonoids, qui ones and cumarins in soapberry extract, and alkaloids and saponins in curare extract. Toxicity in LC50 terms depended of the extract type employed.
Evolución del razonamiento analógico en ni?os: seguimiento desde los seis hasta los once a?os de edad
Abregú Tueros,Luis Fidel;
Avances en Psicología Latinoamericana , 2009,
Abstract: the aim of this study is to establish the time and period of development of analogical reasoning (ar) and evaluate its independence and performance with respect to the age. we performed a longitudinal cohort study of two age groups and six annual follow-up phases from each one (2000-2005, 2001- 2006) in six to eleven years-old children in the city of huanuco (peru) with a sample of 167 children (first stage), and n=121 (sixth stage). the raven's progressive matrices test, coloured version, was applied individually without time limits. results indicate that ar development occurs in a constant and late way from seven to eleven years-old children, and also that there is independence between the ability of ar and the children age. we discuss the importance of knowledge in the relationships between analogies topics, adjusted to the age, as a mediating factor in the development of ar.
Evolución del razonamiento analógico en ni os: seguimiento desde los seis hasta los once a os de edad
Luis Fidel Abregú Tueros
Avances en Psicología Latinoamericana , 2009,
Abstract: El objetivo del estudio es establecer el momento y período de desarrollo del razonamiento analógico (RA) y evaluar su independencia y desempe o respecto a la edad. Se aplicó un dise o longitudinal de cohortes de dos grupos etáreos y seis etapas anuales de seguimiento para cada uno (2000-2005, 2001- 2006) desde seis hasta once a os de edad en ni os de la ciudad de Huánuco, Perú, en una muestra de ciento sesenta y siete ni os (primera Etapa) y n=121 (sexta etapa). Se administró en forma individual y sin límite de tiempo la prueba de matrices de Raven versión coloreada. Los resultados indican que la evolución del RA en ni os ocurre en forma tardía y constante a partir de los siete y hasta los once a os; así mismo, que existe independencia entre la capacidad de RA y la edad de los ni os. Se discute la importancia del conocimiento en las relaciones de análogo y tópico ajustadas a la edad como el factor mediador de desarrollo del RA.
Discarded low energy particles in extensive air shower simulations: Effect on the shower Missing and Invisible Energy
M. J. Tueros
Physics , 2009,
Abstract: The energy carried away by neutral particles in ultra high energy cosmic ray showers can not be detected by fluorescence detectors. This energy is usually referred to as the "invisible energy". Since every shower has a fraction of invisible energy, the energy determined using the fluorescence technique is always less than the primary energy and a correction needs to be applied. This correction, usually referred to as the "missing energy", can only be estimated using Monte Carlo simulations. In this article we study in detail the influence that discarding low energy particles from the simulation has on the estimation of the missing and invisible energies. We found that although the effect is not important for the invisible energy,an important bias on the missing energy is introduced that can reach 30% or more depending on the low energy cut value. We present a prescription on how to correct for this bias in AIRES simulations and give a novel missing energy parametrization including results for photons and for the QGSJET-II hadronic model. We also show that although missing and invisible energies are closely related they are conceptually different ideas if we consider the medium contribution to the shower energy.
Discarded low energy particles in extensive air shower simulations: Effect on the shower Energy Deposit
M. J. Tueros
Physics , 2009,
Abstract: The simulation of particle cascades initiated in the atmosphere by ultra high energy cosmic ray particles involves the generation and propagation of a huge amount of particles. As it is unpractical to follow every particle to its end, particles below a certain energy ($E_{Cut}$) are discarded from the simulation. In this article we study in detail the influence that this cut has on the total energy deposited in the atmosphere by the particle cascade in AIRES simulations. The energy deposit is directly related to the emission of fluorescence light and is critical for the accurate simulation of shower signals in fluorescence detectors. Not correcting for the discarded particles introduces a bias on several shower observables related to the energy deposit that can range from 3 to 30% or more depending on the $E_{Cut}$ value used. A prescription for the correct treatment of these particles is proposed, and the resulting corrections to the total energy deposit are addressed, including a new universal parametrization of the mean energy deposit per particle. The low energy cut is introduced in the simulations to reduce the required CPU time per shower at the expense of simulation accuracy. We find that a 0.4 MeV cut for electrons and 0.9 MeV cut for gammas is an adequate compromise, and that the proposed prescription is capablable of removing the bias introduced by this cut. The prescription is independent of the energy cut value and can be used to correct and compare simulations made with different energy cuts.
Cosmic reionization by primordial cosmic rays
Matias Tueros,Maria Victoria del Valle,Gustavo Esteban Romero
Physics , 2014, DOI: 10.1051/0004-6361/201424666
Abstract: After the so-called cosmic recombination, the expanding universe entered into a period of darkness since most of the matter was in a neutral state. About a billion years later, however, the intergalactic space was once again ionized. The process, known as the cosmic reionization, required the operation of mechanisms that are not well understood. Among other ionizing sources, Population III stars, mini-quasars, and X-ray emitting microquasars have been invoked. In this article we propose that primordial cosmic rays, accelerated at the termination points of the jets of the first microquasars, may have contributed to the reionization of the intergalactic space as well. For this we quantify the ionization power of cosmic rays (electrons and protons) in the primordial intergalactic medium using extensive particle cascade simulations. We establish that, depending on the fraction of electrons to protons accelerated in the microquasar jets, cosmic rays should have contributed to the reionization of the primordial intergalactic medium as much as X-rays from microquasar accretion disks. If the primordial magnetic field was of the order of $10^{-17}$ G, as some models suggest, cosmic rays had an important role in ionizing the neutral material far beyond the birth places of the first stars.
Le travail des femmes à Frías: modèle andin et variante régionale
Barrera, Mercedes,Gastellu, Jean-Marc,Hocquenghem, Anne-Marie,Tueros, Rolando
Bulletin de l'Institut Francais d'études Andines , 1993,
Abstract: à Frías, dans les Andes de Piura, les femmes sont absentes des taches de production agricole au sens strict. Une comparaison avec des études menées dans d autres régions montre en quoi cette organisation diffère d un modèle andin. Mais ce modèle est trompeur. Il recouvre une grande variété de situations. Entre autres facteurs, la reconstitution du passé d un système de production est nécessaire pour comprendre son orientation actuelle. EL TRABAJO DE LAS MUJERES EN FRíAS: MODELO ANDINO Y VARIANTE REGIONAL. En Frías, en la sierra de Piura, las mujeres no participan en las tareas de producción agrícola en el sentido estricto. Una comparación con estudios realizados en otras regiones indica cómo esta organización difiere de un modelo andino. Pero, este modelo, que hemos construido, encubre una gran diversidad de casos. Entre otros factores, la reconstitución del pasado de un sistema de producción es necesaria para entender su orientación actual. WOMEN S WORK: ANDEAN PATTERN AND LOCAL VARIATION. Women are not present in agricultural working stricto sensu in Frías, in the Piura highlands. A comparison of the pattern of organization with case studies in other regions of Peru shows differences with the Andean pattern. But the pattern described here covers a great diversity of situations. Among many factors, the historical reconstitution of a farming system is necessary to understand its current orientation.
Coherent Cherenkov radio pulses from hadronic showers up to EeV energies
Jaime Alvarez-Muniz,Washington R. Carvalho Jr.,Matias Tueros,Enrique Zas
Physics , 2010, DOI: 10.1016/j.astropartphys.2011.10.002
Abstract: The Cherenkov radio pulse emitted by hadronic showers in ice is calculated for showers of energies in the EeV range. This is obtained with three dimensional simulations of both shower development and the coherent radio pulse emitted as the excess charge develops in the shower. A Monte Carlo, ZHAireS, has been developed for this purpose combining the high energy hadronic interaction capabilities of AIRES, and the dense media propagation capabilities of TIERRAS, with the precise low energy tracking and specific algorithms developed to calculate the radio emission in ZHS. A thinning technique is implemented and optimized to allow the simulation of radio pulses induced by showers up to 10 EeV in ice. The code is validated comparing the results for electromagnetic and hadronic showers to those obtained with GEANT4 and ZHS codes. The contribution to the pulse of other shower particles in addition to electrons and positrons, mainly pions and muons, is found to be below 1%. The characteristics of hadronic showers and the corresponding Cherenkov frequency spectra are compared with those from purely electromagnetic showers. The dependence of the spectra on shower energy and high-energy hadronic model is addressed and parameterizations for the radio emission in hadronic showers in ice are given for practical applications.
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