320 research outputs found
Thermodynamic formalism for contracting Lorenz flows
We study the expansion properties of the contracting Lorenz flow introduced
by Rovella via thermodynamic formalism. Specifically, we prove the existence of
an equilibrium state for the natural potential for the contracting Lorenz flow and for in an interval
containing . We also analyse the Lyapunov spectrum of the flow in terms
of the pressure
Magneto-Acoustic Wave Oscillations in Solar Spicules
Some observations suggest that solar spicules show small amplitude and high
frequency oscillations of magneto-acoustic waves, which arise from photospheric
granular forcing. We apply the method of MHD seismology to determine the period
of kink waves. For this purposes, the oscillations of a magnetic cylinder
embedded in a field-free environment is investigated. Finally, diagnostic
diagrams displaying the oscillatory period in terms of some equilibrium
parameters are provided to allow a comparison between theoretical results and
those coming from observations.Comment: 10 pages, 4 fig
PROFIT: a new alternative for emission-line PROfile FITting
I briefly describe a simple routine for emission-line profiles fitting by
Gaussian curves or Gauss-Hermite series. The PROFIT (line-PROfile FITting)
routine represent a new alternative for use in fits data cubes, as those from
Integral Field Spectroscopy or Fabry-Perot Interferometry, and may be useful to
better study the emission-line flux distributions and gas kinematics in
distinct astrophysical objects, such as the central regions of galaxies and
star forming regions. The PROFIT routine is written in IDL language and is
available at http://www.ufsm.br/rogemar/software.html.
The PROFIT routine was used to fit the [Fe II]1.257um emission-line profiles
for about 1800 spectra of the inner 350 pc of the Seyfert galaxy Mrk1066
obtained with Gemini NIFS and shows that the line profiles are better
reproduced by Gauss-Hermite series than by the commonly used Gaussian curves.
The two-dimensional map of the h_3 Gauss-Hermite moment shows its highest
absolute values in regions close to the edge of the radio structure. These high
values may be originated in an biconical outflowing gas associated with the
radio jet - previously observed in the optical [O III] emission. The analysis
of this kinematic component indicates that the radio jet leaves the center of
the galaxy with the north-west side slightly oriented towards us and the
south-east side away from us, being partially hidden by the disc of the galaxy.Comment: Accepted for publication Astrophysics & Space Science - 7 pges; 4
Fig
Glutamine synthetase and glutamate synthase activities in relation to nitrogen fixation in Lotus spp.
Opinion dynamics: models, extensions and external effects
Recently, social phenomena have received a lot of attention not only from
social scientists, but also from physicists, mathematicians and computer
scientists, in the emerging interdisciplinary field of complex system science.
Opinion dynamics is one of the processes studied, since opinions are the
drivers of human behaviour, and play a crucial role in many global challenges
that our complex world and societies are facing: global financial crises,
global pandemics, growth of cities, urbanisation and migration patterns, and
last but not least important, climate change and environmental sustainability
and protection. Opinion formation is a complex process affected by the
interplay of different elements, including the individual predisposition, the
influence of positive and negative peer interaction (social networks playing a
crucial role in this respect), the information each individual is exposed to,
and many others. Several models inspired from those in use in physics have been
developed to encompass many of these elements, and to allow for the
identification of the mechanisms involved in the opinion formation process and
the understanding of their role, with the practical aim of simulating opinion
formation and spreading under various conditions. These modelling schemes range
from binary simple models such as the voter model, to multi-dimensional
continuous approaches. Here, we provide a review of recent methods, focusing on
models employing both peer interaction and external information, and
emphasising the role that less studied mechanisms, such as disagreement, has in
driving the opinion dynamics. [...]Comment: 42 pages, 6 figure
Amabilidad, confort y espiritualidad en los cuidados paliativos oncológicos: Aporte para la humanización en salud
Introduction. For terminally ill cancer patients, it is essential to feel welcome, comfortable, and receive spiritual
support during hospitalization. Objective. Describe the kindness, comfort measures and support provided
spiritual care to the terminally ill cancer patients as perceived by nurses and family caregivers in a hospital in
Chiclayo, Peru. Methods: Qualitative descriptive research, the convenience sample and the sample so formed
06 nurses and 06 family caregivers of cancer patients at terminal stage, obtained by the technique of saturation
and redundancy. To collect data was used to guide semistructured interview validated by expert judgment
and pilot, which was recorded prior informed consent. Data were processed manually by thematic content
analysis. Results. a) The friendliness of the nurse-patient, b) Measures of comfort for satisfying basic needs, c)
Spiritual support for the relief of suffering. Conclusions. Humanization in caring for cancer patients starts with
the kindness that refers to the greeting, respect and therapeutic touch, even at a time when nurses perform
comfort measures to relieve pain and satisfaction of basic needs the collaboration of the accompanying family;
certainly the spiritual support, expressed in promoting faith rescues hope, prayer, respecting the religious
beliefs and practices. Cancer is likely to generate higher sensitivity and compassion in health personnel.Introducción. Para los pacientes oncológicos en fase terminal, es fundamental sentirse acogidos, cómodos, y
recibir apoyo espiritual durante su hospitalización. Objetivo: Describir la amabilidad, las medidas de confort y
el apoyo espiritual que se brinda en el cuidado al paciente oncológico en fase terminal según la percepción de
enfermeras y familiares cuidadores en un hospital de Chiclayo-Perú. Método. Investigación cualitativa descriptiva,
el muestreo fue por conveniencia y la muestra lo conformó 06 enfermeras y 06 familiares cuidadores de pacientes
oncológicos en fase terminal, obtenidos por la técnica de saturación y redundancia. Para recolectar los datos se
usó guía de entrevista semiestructurada validado por juicio de expertos y prueba piloto, la cual fue grabada previo
consentimiento informado. Los datos fueron procesados de manera manual mediante el análisis de contenido
temático. Resultados. a) La amabilidad en la relación enfermera-paciente, b) Medidas de confort para satisfacción
de necesidades básicas, c) Apoyo espiritual para el alivio del sufrimiento. Conclusiones. Existe humanización
en el cuidado a pacientes oncológicos, se inicia con la amabilidad que se refiere al saludo, el respeto y el toque
terapéutico, aun en momentos en que las enfermeras realizan las medidas de confort para aliviar el dolor y la
satisfacción de las necesidades básicas con la colaboración del familiar acompañante; sin duda se rescata el
apoyo espiritual, que se expresa en el fomento de la fe, la esperanza, la oración, respetando las creencias y
prácticas religiosas. Es probable que el cáncer genere mayor sensibilidad y compasión en el personal de salud.Introdução. Para pacientes com câncer em estado terminal, é essencial para se sentir bem-vindo, confortável,
e receber apoio espiritual durante a hospitalização. Objetivo. Descreva a bondade, medidas de conforto e
apoio prestado assistência espiritual aos pacientes com câncer em estado terminal, como percebido pelos
enfermeiros e cuidadores familiares em um hospital em Chiclayo, Peru. Método. Pesquisa qualitativa
descritiva, a amostra de conveniência e a amostra assim formado 06 enfermeiras e 06 cuidadores familiares
de doentes com cancro na fase terminal, obtidos pela técnica de saturação e redundância. Para coleta
de dados foi usado para guiar entrevista semi-estruturada validada pelo julgamento e perito piloto, que foi
gravado consentimento prévio. Os dados foram processados manualmente por meio de análise de conteúdo
temática. Resultados. a) A simpatia das Medidas de enfermeiro-paciente, b) de conforto para satisfazer
as necessidades básicas, c) apoio espiritual para o alívio do sofrimento. Conclusões. Humanização no
atendimento de pacientes com câncer começa com a bondade que se refere ao cumprimento, respeito e
toque terapêutico, mesmo num momento em que os enfermeiros executar medidas de conforto para aliviar
a dor e satisfação das necessidades básicas a colaboração da família de acompanhamento; certamente o
apoio espiritual, expressa na promoção resgata esperança fé, oração, respeitando as crenças e práticas
religiosas. O câncer é susceptível de gerar maior sensibilidade e compaixão em pessoal de saúde
The genera Melanothamnus Bornet & Falkenberg and Vertebrata S.F. Gray constitute well-defined clades of the red algal tribe Polysiphonieae (Rhodomelaceae, Ceramiales).
Polysiphonia is the largest genus of red algae, and several schemes subdividing it into smaller taxa have been proposed since its original description. Most of these proposals were not generally accepted, and currently the tribe Polysiphonieae consists of the large genus Polysiphonia (190 species), the segregate genus Neosiphonia (43 species), and 13 smaller genera (< 10 species each). In this paper, phylogenetic relationships of the tribe Polysiphonieae are analysed, with particular emphasis on the genera Carradoriella, Fernandosiphonia, Melanothamnus, Neosiphonia, Polysiphonia sensu stricto, Streblocladia and Vertebrata. We evaluated the consistency of 14 selected morphological characters in the identified clades. Based on molecular phylogenetic (rbcL and 18S genes) and morphological evidence, two speciose genera are recognized: Vertebrata (including the type species of the genera Ctenosiphonia, Enelittosiphonia, Boergeseniella and Brongniartella) and Melanothamnus (including the type species of the genera Fernandosiphonia and Neosiphonia). Both genera are distinguished from other members of the Polysiphonieae by synapomorphic characters, the emergence of which could have provided evolutionarily selective advantages for these two lineages. In Vertebrata trichoblast cells are multinucleate, possibly associated with the development of extraordinarily long, photoprotective, trichoblasts. Melanothamnus has 3-celled carpogonial branches and plastids lying exclusively on radial walls of the pericentral cells, which similarly may improve resistance to damage caused by excessive light. Other relevant characters that are constant in each genus are also shared with other clades. The evolutionary origin of the genera Melanothamnus and Vertebrata is estimated as 75.7-95.78 and 90.7-138.66 Ma, respectively. Despite arising in the Cretaceous, before the closure of the Tethys Seaway, Melanothamnus is a predominantly Indo-Pacific genus and its near-absence from the northeastern Atlantic is enigmatic. The nomenclatural implications of this work are that 46 species are here transferred to Melanothamnus, six species are transferred to Vertebrata and 13 names are resurrected for Vertebrata
Avanços recentes em nutrição de larvas de peixes
Os requisitos nutricionais de larvas de peixes são ainda mal compreendidos, o que leva a altas mortalidades
e problemas de qualidade no seu cultivo. Este trabalho pretende fazer uma revisão de novas metodologias de investigação, tais
como estudos com marcadores, genómica populacional, programação nutricional, génomica e proteómica funcionais, e
fornecer ainda alguns exemplos das utilizações presentes e perspectivas futuras em estudos de nutrição de larvas de peixes
Test of Lorentz and CPT violation with Short Baseline Neutrino Oscillation Excesses
The sidereal time dependence of MiniBooNE electron neutrino and anti-electron
neutrino appearance data are analyzed to search for evidence of Lorentz and CPT
violation. An unbinned Kolmogorov-Smirnov test shows both the electron neutrino
and anti-electron neutrino appearance data are compatible with the null
sidereal variation hypothesis to more than 5%. Using an unbinned likelihood fit
with a Lorentz-violating oscillation model derived from the Standard Model
Extension (SME) to describe any excess events over background, we find that the
electron neutrino appearance data prefer a sidereal time-independent solution,
and the anti-electron neutrino appearance data slightly prefer a sidereal
time-dependent solution. Limits of order 10E-20 GeV are placed on combinations
of SME coefficients. These limits give the best limits on certain SME
coefficients for muon neutrino to electron neutrino and anti-muon neutrino to
anti-electron neutrino oscillations. The fit values and limits of combinations
of SME coefficients are provided.Comment: 14 pages, 3 figures, and 2 tables, submitted to Physics Letters
Interação entre cultivares, estirpes comerciais de Rhizobium meliloti e fungicidas no incremento da produção de alfafa
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