2,726 research outputs found
Pioneer Anomaly: Evaluating Newly Recovered Data
The Pioneer 10/11 spacecraft yielded the most precise navigation in deep
space to date. However, their radio-metric tracking data received from the
distances between 20--70 astronomical units from the Sun consistently indicated
the presence of a small, anomalous, Doppler frequency drift. The drift is a
blue frequency shift that can be interpreted as a sunward acceleration of a_P =
(8.74 +/- 1.33) x 10^(-10) m/s^2 for each particular spacecraft. This signal
has become known as the Pioneer anomaly; the nature of this anomaly remains
unexplained.
New Pioneer 10 and 11 radio-metric Doppler data recently became available.
The much extended set of Pioneer Doppler data is the primary source for new
upcoming investigation of the anomaly. We also have almost entire records of
flight telemetry files received from the the Pioneers. Together with original
project documentation and newly developed software tools, this additional
information is now used to reconstruct the engineering history of both
spacecraft. To that extent, a thermal model of the Pioneer vehicles is being
developed to study possible contribution of thermal recoil force acting on the
two spacecraft. In addition, to improve the accuracy of orbital reconstruction,
we developed a new approach that uses actual flight telemetry data during
trajectory analysis of radio-metric Doppler files. The ultimate goal of these
efforts is to investigate possible contributions of the thermal recoil force to
the detected anomalous acceleration.Comment: 12 pages, 15 figures, invited talk at the "III Mexican Meeting on
Mathematical and Experimental Physics," Mexico City, Mexico, 10-14 September
200
Bayesian blind component separation for Cosmic Microwave Background observations
We present a technique for the blind separation of components in CMB data.
The method uses a spectral EM algorithm which recovers simultaneously component
templates, their emission law as a function of wavelength, and noise levels. We
test the method on Planck HFI simulated observations featuring 3 astrophysical
components.Comment: 15 pages, 5 figures, to appear in the Proceedings of the MAXENT 2001
international worksho
QFT results for neutrino oscillations and New Physics
The CP asymmetry in neutrino oscillations, assuming new physics at production
and/or detection processes, is analyzed. We compute this CP asymmetry using the
standard quantum field theory within a general new physics scenario that may
generate new sources of CP and flavor violation. Well known results for the CP
asymmetry are reproduced in the case of V -A operators, and additional
contributions from new physics operators are derived. We apply this formalism
to SUSY extensions of the Standard Model where the contributions from new
operators could produce a CP asymmetry observable in the next generation of
neutrino experiments.Comment: 6 pages, 3 figures, version to be published in Phys.Rev.
Limits to differences in active and passive charges
We explore consequences of a hypothetical difference between active charges,
which generate electric fields, and passive charges, which respond to them. A
confrontation to experiments using atoms, molecules, or macroscopic matter
yields limits on their fractional difference at levels down to 10^-21, which at
the same time corresponds to an experimental confirmation of Newtons third law.Comment: 6 pages Revtex. To appear in Phys. Rev.
Pensamiento Complejo, Bases Para Una Teoria Holistica De La Educacion Superior En El Rediseño Curricular/Complex Thinking, Bases for a Holistic Theory of Higher Education in Curricular Redesign
El objetivo del presente artículo, consiste en realizar una reflexión sobre la perspectiva epistemológica de la complejidad desde las perspectivas de las ciencias. En este sentido, se defiende que un enfoque holístico puede servir de ayuda activa en la enseñanza de la complejidad desde un enfoque crítico y reflexivo amparados en nuevos paradigmas. Después de la relación del pensamiento complejo y la perspectiva holística en el aprendizaje con la dimensión mente que piensa, mente que siente, y mente intuitiva en la educación, trazamos la posibilidad de configurar diseños curriculares de aprendizaje relacionalmente desde la reflexión teórica donde se destaca los nuevos contenidos y asignaturas y la teoría fundamentada en la praxis que radica, en identificar procesos sociales mediante la construcción de teoría a partir de la realidad objetiva. Terminamos formulando desde la perspectiva filosófica y desde la concepción de la realidad se desprende, metódicamente, tres tipos de formaciones profesionales integradas y simultáneas, a partir de las cuales los profesionales en formación adquieren conocimientos, valores y prácticas demostrables transversalmente, durante toda su formación.
The objective of the present article consists of the analysis of the new paradigms of the holistic education and its repercussions on higher education defined by the complexity and multidisciplinary. In this sense it is argued that a holistic approach can serve as an active help in the teaching of complexity from a critical and reflexive approach supported by new paradigms. After the relation complex thought and the holistic perspective in learning with the dimension thinking mind, feeling mind and intuitive mind in education, we design the possibility of figuring out learning curricular designs rationally from the theoretical reflection where the new contents and subject matters are outstanding as well as the theory based on the praxis which leads to identify social processes through the construction of theory from objective reality. We conclude by formulating from the philosophical perspective and the reality conception methodically three types of integrated and simultaneous professional formations from which professionals in formation acquire knowledge, cross demonstrable practices and values during all their formation.
Palabras claves: Pensamiento complejo, educación holística, cerebro triuno afecto, rediseño curricular.
Keywords: Complex thought, holistic education, triune brain, curricular redesign
Facies de abanico fluvial en los afloramientos orientales de Formación Peraltilla
La Formación Peraltilla está constituida por una sucesión estratigráfica heterolitica, del Oligoceno inferior. El análisis de facies indica una asociación de ambientes de abanicos fluviales húmedos, formados por canales múltiples de baja sinuosidad, y una tendencia vertical a la progradación de los sistemas fluviales
Fijación activa y perforación ventricular: ¿una nueva entidad?
First, a new active fixation lead was implanted in the interventricular septum; the old lead was then extracted with a Cook stylet. The
patient’s clinical course was satisfactory and there were no procedure-related complications.
In conclusion, within the battery of diagnostic tests available to investigate suspected cardiac perforation, computed angiotomography
of the chest is a highly useful complementary technique for the management of this complication
Occurrence of bovine hydatidosis and evaluation of its risk to humans in traditional communities of Southern Region of Ethiopia
Background: Cystic Echinococcosis/ Hydatid Disease, is an infection caused by the larval stage of the tapeworm Echinococcus granulosus, one of the most widespread parasitic zoonoses.Objective: To determine the occurrence, localization and fertility/sterility rates of hydatid cyst in cattle, to determine the prevalence of adult E. granulosus in dogs and asses the risk for human infection in traditional communities.Methods: Postmortem examination, hydatid cyst characterization, questionnaire survey and dog stool sample examination were carried out.Results: Of the total 320 ruminants examined at backyard slaughtering, 151 (47.2%) were found harboring hydatid cysts. The liver and lungs were the two main infected organs, 34.4% and 52.3%, respectively. The majority of the cysts found were small, 54.3%, and medium, 37.7%. From the total number of cysts found, 70.2% were sterile, while 29.8% were fertile. A questionnaire survey revealed that local people were unaware of the life cycle of E. granulosus and the perpetuation of its life cycle by their cultural and traditional practices. Dogs have intimate contact with humansand other domestic animals, share the same house and also dogs do not have access for veterinary care. Stool samples of 62 dogs were collected and analyzed with a 30% prevalence of taenia infection confirmed to be E. granulosus.Conclusion: Because of the high prevalence of E. granulosus infection in dogs and hydatidosis in cattle as well as common practice of backyard slaughtering, the risk of human infection in traditional communities is suspected to be high and requires immediate attention to study the status of cystic ehinococcosis in the human population of the study area.[Ethiop. J. Health Dev. 2012;26(1):43-48
Facies de abanicos fluvial en los afloramientos orientales de la formación peratalita
La Formación Peraltilla está constituida por una sucesión estratigráfica heterolitica, del Oligoceno inferior. El análisis de facies indica una asociación de ambientes de abanicos fluviales húmedos, formados por canales múltiples de baja sinuosidad, y una tendencia vertical a la progradación de los sistemas fluviales.The Peraltilla Formation consits of a heterogeneous succession of Early Oligocene age. Facies analysis revealed a characteristic paleoenvironmental association of wet fluvial fan deposits, formed by multiple low sinuosity channels. The stratigraphic succession evidences an evolution upward related to the progradation of the fluvial systems
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