Comparative Analysis of Multiplicity Distributions in Inelastic Processes for Different Colliding Particles and Nuclei

Theoretical prediction of oscillations of cumulant moments of parton multiplicity distributions inside a jet supported by experimental data in some multiple production processes asks for analysis of the phenomenon for the whole set of available reactions. We have found out that the oscillations persist in any kind of processes and increase for particles with more complicated structure i.e. in the order of ee, eh, hh, hA, AA. The effect is not strongly dependent on the available phase space. Theoretical values of moments for quark and gluon jets up to 5th rank are shown. Zeros of the truncated generating function and singularities of the total generating function are discussed.Comment: revised version -- no changes in the text, corrected 3 references; 10 pages, 4 Postscript figure

Public transport accessibility model based on user experience of the urban context

Los desafíos de transporte urbano poseen importantes aspectos técnicos y geográficos, pero éstas son solo dimensiones parciales de la problemática urbana. Para diseñar sistemas de transporte que rompan con los modelos tradicionales se necesita darle un giro más humano a la movilidad, ya que todos los viajes comienzan y terminan con una distancia recorrida a pie. En tal sentido, la calidad del ambiente urbano que rodea las áreas de acceso al Transporte Público (TP) influye en la captación de pasajeros, determinando la experiencia que los usuarios tendrán en los segmentos de acceso, transición y egreso del modo elegido. Este trabajo tiene como objeto elaborar una metodología para evaluar la accesibilidad a sistemas de TP. Se presentan los resultados preliminares del desarrollo de un modelo que intenta ampliar el alcance de las herramientas existentes de análisis, al brindar un marco metodológico a escala humana y desarrollar indicadores que describan cualidades experienciales. Se propone un modelo matemático de regresión ogística de seis variables predictivas, tres de ellas se refieren a aspectos materiales del viaje y tienen en cuenta la infraestructura urbana en diferentes escalas; otras tres se refieren a la experiencia de usuario que deriva de la interacción con el ambiente construido donde se produce el viaje.Mobility and transportation challenges in globalized cities have strong technical and locational facets, but these are only partial dimensions of the problematic. In order to design transportation systems that defy conventional models, a more humane shift towards mobility is needed, understanding that every trip starts and ends with a distance traveled by foot. Within this scope, the urban environment around public transport access areas influences catchment buffer distances, determined by the user experience during the access, transition and egress segments of the trip. This research aims to elaborate a methodological framework to evaluate accessibility that widens the scope of existing analysis tools. The preliminary results of a human-scale accessibility model are presented, elaborating on descriptive indicators of experiential qualities. The Logistic Regression mathematical model used consists of six predictive variables. Three of them describe the material aspects of the trip in different urban scales and the other three account for the user experience that derives from his interaction with the surrounding environment.Fil: Barón, Gabriela N.. Consejo Nacional de Investigaciones Científicas y TécnicasFil: Allende, David G..Fil: Arena, Alejandro P.

Calibration standars of nuclear microprobes

El Micro-haz de iones Pesados (MiP) del laboratorio Tandar constituye un instrumento de características únicas en el país, pues puede proveer haces de iones pesados de dimensiones micrométricas acelerados hasta decenas de MeV de energía. La búsqueda de tamaños de haz más pequeños ha creado la necesidad de contar con estándares de calibración de elevada calidad de resolución. En el presente trabajo se desarrollaron los primeros prototipos para calibrar la focalización del haz: estructuras metálicas de cobre o niquel en forma de grilla con orificios cuadrados. Se emplearon dos métodos de fabricación. En el primero se utilizaron técnicas de fotolitografía convencional sobre un sustrato de silicio con foto-resina, mientras que en el segundo se utilizó el MiP para micro-mecanizar sustratos de Niobato de Litio (LiNbO3). En ambos casos se finalizó el proceso de fabricación del patrón con electrodeposición de cobre o níquel sobre la matriz desarrollada. Mediante la técnica fotolitográfica se fabricaron grillas de níquel que varían entre 130 y 180 mesh**. Mediante micro-mecanizado con el MiP se fabricaron grillas de cobre de entre 500 y 2000 mesh sobre sustratos de LiNbO3.The Micro-heavy ion beam (MiP) at Tandar’s Lab is a unique instrument in the country, as it can provide heavy ion beams at micrometer-scale accelerated to tens of MeV energy. The quest for smaller beam sizes has created the need for calibration standards of high resolution quality. In this paper we developed the first prototypes to calibrate the beam focusing: metal structures of copper or nickel shaped grid with square holes. We used two methods of manufacture. Were used in the first conventional photolithography techniques on a silicon substrate with photoresin while the second was used for micromachining with MiP substrates of lithium niobate (LiNbO3). In both cases the process for the manufacture was finished with electro-deposition of copper or nickel on the matrix developed. By photolithographic technique nickel grids were manufactured varying between 130 and 180 mesh. By MiP micromachining copper grids were produced between 500 and 2000 mesh on LiNbO3 substrates.Fil: Arena, S.. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Faya, T.. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Lell, J.. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes. Gerencia de Investigación y Aplicaciones; ArgentinaFil: Vega, N.. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Davidson, Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Nesprias, Francisco Jose Gabriel. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes. Gerencia de Investigación y Aplicaciones; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Debray, M.. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes. Gerencia de Investigación y Aplicaciones; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentin

Insecticidal activities of diketopiperazines of Nomuraea rileyi entomopathogenic fungus

Entomopathogenic fungi are fungal organisms extensively used in various parts of the world as biopesticides against insect pests that cause important economic damage. Various secondary metabolites produced by these fungi have many potential biological activities. The present study was undertaken to evaluate the insecticidal activity of extracts and pure compounds from Nomuraea rileyi (Farlow) Samson entomopathogenic fungi against Spodoptera frugiperda Smith (Lepidoptera), Ceratitis capitata Wiedemann (Diptera) and Tribolium castaneum Herbst (Coleoptera), three insect pests that generate serious economic losses in the northwest of Argentina. Diketopiperazines were extracted from the culture free supernatant of the media with ethyl acetate. Antifeedant properties were detected in all extracts under dietary choice conditions (300 ug/ g of diet). The maximum antifeedant activity was noted in cycles (Pro-Val) (86.02) and cycle (Pro-Phe) (73.47), while the rest of the extracts and metabolites exhibited varying degrees of moderate or less toxic effects. The maximum oviposition deterrence against C. capitata (55.86%) was recorded with cycle (Pro-Phe) at a 50 µm/cm2 dose. Culture medium extracts supplemented with insect remains and all pure compounds showed repellent action against T. castaneum. The main repellency was observed in phenylacetic acid and cycle (Pro-Val) with RI values of 42 and 41% respectively. The present study would suggest the possible utilization of entomopathogenic fungal metabolites as an effective agent for controlling insect pests that cause important economic losses

Everolimus plus exemestane in postmenopausal patients with HR(+) breast cancer: BOLERO-2 final progression-free survival analysis.

IntroductionEffective treatments for hormone-receptor-positive (HR(+)) breast cancer (BC) following relapse/progression on nonsteroidal aromatase inhibitor (NSAI) therapy are needed. Initial Breast Cancer Trials of OraL EveROlimus-2 (BOLERO-2) trial data demonstrated that everolimus and exemestane significantly prolonged progression-free survival (PFS) versus placebo plus exemestane alone in this patient population.MethodsBOLERO-2 is a phase 3, double-blind, randomized, international trial comparing everolimus (10 mg/day) plus exemestane (25 mg/day) versus placebo plus exemestane in postmenopausal women with HR(+) advanced BC with recurrence/progression during or after NSAIs. The primary endpoint was PFS by local investigator review, and was confirmed by independent central radiology review. Overall survival, response rate, and clinical benefit rate were secondary endpoints.ResultsFinal study results with median 18-month follow-up show that median PFS remained significantly longer with everolimus plus exemestane versus placebo plus exemestane [investigator review: 7.8 versus 3.2 months, respectively; hazard ratio = 0.45 (95% confidence interval 0.38-0.54); log-rank P < 0.0001; central review: 11.0 versus 4.1 months, respectively; hazard ratio = 0.38 (95% confidence interval 0.31-0.48); log-rank P < 0.0001] in the overall population and in all prospectively defined subgroups, including patients with visceral metastases, [corrected] and irrespective of age. The incidence and severity of adverse events were consistent with those reported at the interim analysis and in other everolimus trials.ConclusionThe addition of everolimus to exemestane markedly prolonged PFS in patients with HR(+) advanced BC with disease recurrence/progression following prior NSAIs. These results further support the use of everolimus plus exemestane in this patient population. ClinicalTrials.gov #NCT00863655

Highly deformed 40^{40}Ca configurations in 28^{28}Si + 12^{12}C

The possible occurrence of highly deformed configurations in the $^{40}$Ca di-nuclear system formed in the $^{28}$Si + $^{12}$C reaction is investigated by analyzing the spectra of emitted light charged particles. Both inclusive and exclusive measurements of the heavy fragments (A $\geq$ 10) and their associated light charged particles (protons and $\alpha$ particles) have been made at the IReS Strasbourg {\sc VIVITRON} Tandem facility at bombarding energies of $E_{lab} (^{28}$Si) = 112 MeV and 180 MeV by using the {\sc ICARE} charged particle multidetector array. The energy spectra, velocity distributions, and both in-plane and out-of-plane angular correlations of light charged particles are compared to statistical-model calculations using a consistent set of parameters with spin-dependent level densities. The analysis suggests the onset of large nuclear deformation in $^{40}$Ca at high spin.Comment: 33 pages, 11 figure

Diffusive Spreading of Chainlike Molecules on Surfaces

We study the diffusion and submonolayer spreading of chainlike molecules on surfaces. Using the fluctuating bond model we extract the collective and tracer diffusion coefficients D_c and D_t with a variety of methods. We show that D_c(theta) has unusual behavior as a function of the coverage theta. It first increases but after a maximum goes to zero as theta go to one. We show that the increase is due to entropic repulsion that leads to steep density profiles for spreading droplets seen in experiments. We also develop an analytic model for D_c(theta) which agrees well with the simulations.Comment: 3 pages, RevTeX, 4 postscript figures, to appear in Phys. Rev. Letters (1996

Deformation effects in the 28^{28}Si+12^{12}C and 28^{28}Si+28^{28}Si reaction Search

The possible occurence of highly deformed configurations is investigated in the $^{40}$Ca and $^{56}$Ni di-nuclear systems as formed in the $^{28}$Si+$^{12}$C,$^{28}$Si reactions by using the properties of emitted light charged particles. Inclusive as well as exclusive data of the heavy fragments and their associated light charged particles have been collected by using the {\sc ICARE} charged particle multidetector array. The data are analysed by Monte Carlo CASCADE statistical-model calculations using a consistent set of parameters with spin-dependent level densities. Significant deformation effects at high spin are observed as well as an unexpected large $^{8}$Be cluster emission of a binary nature.Comment: 3 pages latex, 2 eps figures, paper presented in "wokshop on physics with multidetector array (pmda2000)Calcutta, India (to be published at PRAMANA, journal of Physics, India