1,616 research outputs found
Alcohol dehydrogenase and hydrogenase transcript fluctuations during a day/night cycle in Chlamydomonas reinhardtii: the role of anoxia
Possibilidades e Limites do Processo de Contratualização de OrganizaçÔes Sociais de SaĂșde nos Hospitais PĂșblicos Estaduais do EspĂrito Santo
A reassessment of the role of sucrose synthase in the hypoxic sucroseâethanol transition in Arabidopsis
Plants under low-oxygen availability adapt their metabolism to compensate for the lower ATP production that arises from the limited respiratory activity in mitochondria. Anaerobic glycolysis requires continuous fuelling of carbon units, also provided from sucrose. The anaerobic catabolism of sucrose is thought to require the activity of sucrose synthase, being this enzymatic reaction more energetically favourable than that of invertase. The role of sucrose synthases (SUS) for aerobic sucrose catabolism in Arabidopsis has been recently questioned since SUS mutants fail to show altered phenotype or metabolic profile. In the present paper, we analysed the role of SUS1 and SUS4, both induced by low oxygen, in plant survival and ethanol production. The results showed that mutants lacking both SUS were as tolerant to low oxygen as the wild type in most of the experimental conditions tested. Only under conditions of limiting sugar availability the requirement of SUS1 and SUS4 for ethanol production was evident, although partly compensated by invertase activities, as revealed by the use of a double mutant lacking the two major cytosolic invertases. We conclude that, contrary to general belief, the sucrose synthase pathway is not the preferential route for sucrose metabolism under hypoxia
Shock Breakout in Core-Collapse Supernovae and its Neutrino Signature
(Abridged) We present results from dynamical models of core-collapse
supernovae in one spatial dimension, employing a newly-developed Boltzmann
neutrino radiation transport algorithm, coupled to Lagrangean hydrodynamics and
a consistent high-density nuclear equation of state. We focus on shock breakout
and its neutrino signature and follow the dynamical evolution of the cores of
11 M_sun, 15 M_sun, and 20 M_sun progenitors through collapse and the first 250
milliseconds after bounce. We examine the effects on the emergent neutrino
spectra, light curves, and mix of species of artificial opacity changes, the
number of energy groups, the weak magnetism/recoil corrections, nucleon-nucleon
bremsstrahlung, neutrino-electron scattering, and the compressibility of
nuclear matter. Furthermore, we present the first high-resolution look at the
angular distribution of the neutrino radiation field both in the
semi-transparent regime and at large radii and explore the accuracy with which
our tangent-ray method tracks the free propagation of a pulse of radiation in a
near vacuum. Finally, we fold the emergent neutrino spectra with the
efficiencies and detection processes for a selection of modern underground
neutrino observatories and argue that the prompt electron-neutrino breakout
burst from the next galactic supernova is in principle observable and usefully
diagnostic of fundamental collapse/supernova behavior. Though we are not in
this study focusing on the supernova mechanism per se, our simulations support
the theoretical conclusion (already reached by others) that spherical (1D)
supernovae do not explode when good physics and transport methods are employed.Comment: 16 emulateapj pages, plus 24 postscript figures, accepted to The
Astrophysical Journal; text revised; neutrino oscillation section expanded;
Fig. 22 correcte
Transcript Profiling of the Anoxic Rice Coleoptile(Frontiers in Rice Science -from Gene to Field-,The 100^<th> Anniversary of Tohoku University, International Symposium)
Quantum decoherence and neutrino data
In this work we perform global fits of microscopic decoherence models of
neutrinos to all available current data, including LSND and KamLAND spectral
distortion results. In previous works on related issues the models used were
supposed to explain LSND results by means of quantum gravity induced
decoherence. However those models were purely phenomenological without any
underlying microscopic basis. It is one of the main purposes of this article to
use detailed microscopic decoherence models with complete positivity, to fit
the data.The decoherence in these models has contributions not only from
stochastic quantum gravity vacua operating as a medium, but also from
conventional uncertainties in the energy of the (anti)neutrino beam. All these
contributions lead to oscillation-length independent damping factors modulating
the oscillatory terms from which one obtains an excellent fit to all available
neutrino data, including LSND and Kamland spectral distortion.Comment: 27 pages, 2 figure
Developing pulmonary rehabilitation for COVID-19: Are we linked with the present literature? a lexical and geographical evaluation study based on the graph theory
The Coronavirus Disease 2019 (COVID-19) pandemic is a severe ongoing global emergency. Despite high rates of asymptomatic patients, in many cases, the infection causes a rapid decline in pulmonary function due to an acute respiratory distress-like syndrome, leading to multi-organ failure and death. To date, recommendations about rehabilitation on COVID-19 are based on clinical data derived from other similar lung diseases. Rehabilitation literature lacks a standard taxonomy, limiting a proper evaluation of the most effective treatments for patients after COVID-19 infection. In this study, we assessed the clinical and rehabilitative associations and the geographical area involved in interstitial lung diseases (ILD) and in COVID-19, by a mathematical analysis based on graph theory. We performed a quantitative analysis of the literature in terms of lexical analysis and on how words are connected to each other. Despite a large difference in timeframe (throughout the last 23 years for ILD and in the last 1.5 years for COVID-19), the numbers of papers included in this study were similar. Our results show a clear discrepancy between rehabilitation proposed for COVID-19 and ILD. In ILD, the term ârehabilitationâ and other related words such as âexerciseâ and âprogramâ resulted in lower values of centrality and higher values of eccentricity, meaning relatively less importance of the training during the process of care in rehabilitation of patients with ILD. Conversely, ârehabilitationâ was one of the most cited terms in COVID-19 literature, strongly associated with terms such as âexerciseâ, âphysicalâ, and âprogramâ, entailing a multidimensional approach of the rehabilitation for these patients. This could also be due to the widespread studies conducted on rehabilitation on COVID-19, with Chinese and Italian researchers more involved. The assessment of the terms used for the description of the rehabilitation may help to program shared rehabilitation knowledge and avoid literature misunderstandings
- âŠ