857 research outputs found
Dynamics of a Bose-Einstein Condensate of Excited Magnons
The emergence of a non-equilibrium Bose-Einstein-like condensation of magnons
in rf-pumped magnetic thin films has recently been experimentally observed. We
present here a complete theoretical description of the non-equilibrium
processes involved. It it demonstrated that the phenomenon is another example
of the presence of a Bose-Einstein-like condensation in non-equilibrium
many-boson systems embedded in a thermal bath, better referred-to as
Fr\"{o}hlich-Bose-Einstein condensation. The complex behavior emerges after a
threshold of the exciting intensity is attained. It is inhibited at higher
intensities when the magnon-magnon interaction drives the magnons to internal
thermalization. The observed behavior of the relaxation to equilibrium after
the end of the pumping pulse is also accounted for and the different processes
fully described.Comment: 42 pages, 11 figure
Drilling the Seismogenic Zone of an Erosional Convergent Margin: IODP Costa Rica Seismogenesis Project CRISP
Drilling the Seismogenic Zone of an Erosinal Convergent Margin: IODP Costa Rica Seismogenesis Project CRISP
Analysis and verification of ECA rules in intelligent environments
Intelligent Environments (IEs) are physical spaces where Information Technology (IT) and other pervasive computing technologies are combined in order to achieve specific goals for the users and the environment. IEs have the goal of enriching user experience, increasing awareness of the environment. A number of applications are currently being deployed in domains ranging from smart homes to e-health and autonomous vehicles. Quite often IE support human activities, thus essential requirements to be ensured are correctness, reliability, safety and security. In this paper we present how a set of techniques and tools that have been developed for the verification of software can be employed in the verification of IE described by means of event-condition-action rules. More precisely, we reduce the problem of verifying key properties of these rules to satisfiability and termination problems that can be addressed using state-of-the-art Satisfiability Modulo Theory (SMT) solvers and program analysers. Our approach has been implemented in a tool called vIRONy. Our approach has been validated on a number of case studies from the literature
Bone-anchored hearing implant surgery: our experience with linear incision and punch techniques.
Apogeotropic posterior semicircular canal benign paroxysmal positional vertigo: some clinical and therapeutic considerations
We lately reported the cases of patients complaining positional vertigo whose nystagmic pattern was that of a peripheral torsional vertical positional down beating nystagmus originating from a lithiasis of the non-ampullary arm of the posterior semicircular canal (PSC). We considered this particular pathological picture the apogeotropic variant of PSC benign paroxysmal positional vertigo (BPPV). Since the description of the pilot cases we observed more than 150 patients showing the same clinical sign and course of symptoms. In this paper we describe, in detail, both nystagmus of apogeotropic PSC BPPV (A-PSC BPPV) and symptoms reported by patients trying to give a reasonable explanation for these clinical features. Moreover we developed two specific physical therapies directed to cure A-PSC BPPV. Preliminary results of these techniques are related
Symbolic verification of event–condition–action rules in intelligent environments
In this paper we show how state-of-the art SMT-based techniques for software verification can be employed in the verification of event–condition–action rules in intelligent environments. Moreover, we exploit the specific features of intelligent environments to optimise the verification process. We compare our approach with previous work in a detailed evaluation section, showing how it improves both performance and expressivity of the language for event–condition–action rules
Frutose e NAFLD: implicações metabólicas e modelos de indução em ratos
PURPOSE: The increase in fructose consumption is paralleled by a higher incidence of obesity worldwide. This monosaccharide is linked to metabolic syndrome, being associated with hypertriglyceridemia, hypertension, insulin resistance and diabetes mellitus. It is metabolized principally in the liver, where it can be converted into fatty acids, which are stored in the form of triglycerides leading to NAFLD. Several models of NAFLD use diets high in simple carbohydrates. Thus, this study aimed to describe the major metabolic changes caused by excessive consumption of fructose in humans and animals and to present liver abnormalities resulting from high intakes of fructose in different periods of consumption and experimental designs in Wistar rats. METHODS: Two groups of rats were fasted for 48 hours and reefed for 24 or 48 hours with a diet containing 63% fructose. Another group of rats was fed an diet with 63% fructose for 90 days. RESULTS: Refeeding for 24 hours caused accumulation of large amounts of fat, compromising 100% of the hepatocytes. The amount of liver fat in animals refed for 48 hours decreased, remaining mostly in zone 2 (medium-zonal). In liver plates of Wistar rats fed 63% fructose for 45, 60 and 90 days it's possible to see that there is an increase in hepatocytes with fat accumulation according to the increased time; hepatic steatosis, however, is mild, compromising about 20% of the hepatocytes. CONCLUSIONS: Fructose is highly lipogenic, however the induction of chronic models in NAFLD requires long periods of treatment. The acute supply for 24 or 48 hours, fasted rats can cause big changes, liver steatosis with macrovesicular in all lobular zones.OBJETIVO: O aumento do consumo de frutose é concomitante a maior incidência mundial de obesidade. Este monossacarídeo está relacionado à Síndrome Metabólica, sendo vinculado à hipertrigliceridemia, hipertensão arterial, resistência à insulina e diabetes mellitus. É metabolizada principalmente no fígado, onde pode ser convertida em ácidos graxos, os quais serão estocados na forma de trigligérides ocasionando a esteatose hepática não alcoólica (NAFLD). Vários modelos de NAFLD utilizam dietas ricas em carboidratos simples. Desta forma, este trabalho teve como objetivos descrever as principais alterações metabólicas causadas pelo consumo excessivo de frutose em humanos e em animais e apresentar as alterações hepáticas decorrentes da alta ingestão de frutose em diferentes períodos de consumo e desenhos experimentais em ratos Wistar. MÉTODOS: Dois grupos de ratos Wistar foram mantidos em jejum durante 48 horas e realimentados por 24 ou 48 horas com dieta contendo 63% de frutose. Outro grupo de ratos Wistar foi alimentado com 63% de frutose durante 90 dias. RESULTADOS: A realimentação por 24 horas provocou acúmulo de grande quantidade de gordura. A quantidade de gordura hepática nos animais realimentados por 48 horas diminuiu, mantendo-se principalmente nas zona 2 (medio-zonal). Em fígados de ratos Wistar alimentados com 63% de frutose até 90 dias foi possível observar que há aumento de hepatócitos com acúmulo de gordura consequente ao aumento do tempo, no entanto a esteatose hepática é leve (20%). CONCLUSÕES: A frutose é altamente lipogênica, no entanto a indução de NAFLD em modelos crônicos necessita de longos períodos de tratamento. A oferta aguda, por 24 ou 48 horas, a ratos mantidos em jejum é capaz de ocasionar grandes mudanças hepáticas, com presença de esteatose macrovesicular em todas as zonas lobulare
Phase I/II study of single-agent bortezomib for the treatment of patients with myelofibrosis. Clinical and biological effects of proteasome inhibition.
A phase I/II trial was undertaken to determine maximum tolerated dose (MTD), toxicity, clinical efficacy and biological activity of bortezomib in patients with advanced stage primary or post-polycythemia vera/post-essential thrombocythemia myelofibrosis (MF). Bortezomib (0.8, 1.0, or 1.3 mg/m(2)) was administered on days 1, 4, 8, and 11 by intravenous push to patients previously resistant to at least one line of therapy, or with an intermediate/high risk IWG’s score [1]. Therapy was repeated every 28 days for 6 cycles. At 1.3 mg/m(2) dose, one of six patients experienced a dose limiting toxicity, and this was determined to be the MTD. Neither remissions or clinical improvements were recorded in 16 patients treated at this dose level, fulfilling the early stopping rule in the Simon two-stage study design. Major toxicity was on thrombocytopenia. In 9 out of 15 patients bortezomib proved able to reduce bone marrow vessel density. However, the agent was associated with worsening of markers of disease activity, like enhancement of hematopoietic CD34-positive progenitor cell mobilization, WT-1 gene expression in mononuclear cells, and down-regulation of CXCR4 expression on CD34-positive cells. Occurrence of both beneficial and detrimental biological effects claims further investigation on the mechanisms of the drug in MF
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