1,330 research outputs found
Design of a Cooper pair box electrometer for application to solid-state and astroparticle physics
We describe the design and principle of operation of a fast and sensitive
electrometer operated at millikelvin temperatures, which aims at replacing
conventional semiconducting charge amplifiers in experiments needing low
back-action or high sensitivity. The electrometer consists of a Cooper Pair box
(CPB) coupled to a microwave resonator, which converts charge variations to
resonance frequency shifts. We analyze the dependence of the sensitivity on the
various parameters of the device, and derive their optimization. By exploiting
the nonlinearities of this electrometer, and using conventional nanofabrication
and measurement techniques, a charge sensitivity of a few can be achieved which outperforms existing single charge
electrometers.Comment: 13 pages, 7 figure
Model of a multiverse providing the dark energy of our universe
It is shown that the dark energy presently observed in our universe can be
regarded as the energy of a scalar field driving an inflation-like expansion of
a multiverse with ours being a subuniverse among other parallel universes. A
simple model of this multiverse is elaborated: Assuming closed space geometry,
the origin of the multiverse can be explained by quantum tunneling from
nothing; subuniverses are supposed to emerge from local fluctuations of
separate inflation fields. The standard concept of tunneling from nothing is
extended to the effect that in addition to an inflationary scalar field, matter
is also generated, and that the tunneling leads to an (unstable) equilibrium
state. The cosmological principle is assumed to pertain from the origin of the
multiverse until the first subuniverses emerge. With increasing age of the
multiverse, its spatial curvature decays exponentially so fast that, due to
sharing the same space, the flatness problem of our universe resolves by
itself. The dark energy density imprinted by the multiverse on our universe is
time-dependent, but such that the ratio of its mass
density and pressure (times ) is time-independent and assumes a value
with arbitrary . can be chosen so
small, that the dark energy model of this paper can be fitted to the current
observational data as well as the cosmological constant model.Comment: 32 pages, 4 figure
第14回千葉カルシウム代謝研究会
(A) The DNA distribution of cells treated with bicyclol-AKT cDNA-, bicyclol-AKT cDNA+, bicyclol + AKT cDNA- and bicyclol + AKT cDNA+. The cDNA was transfected as mentioned in Methods. Then the cells were treated with bicyclol for 24 h (B) The DNA distribution of cells treated with bicyclol or/and LY294002 for 24 h. (C) The DNA distribution of cells treated with bicyclol or/and PD98059 for 24 h. (TIF 809 kb
EL SILENCIO EN EL MONSTRUO DEL MANZANARES
Este trabajo estudia la función del silencio en la novela El monstruo del
Manzanares, novela corta incluida en la colección La mojiganga del gusto (1641) de Andrés
Sanz del Castillo. Esta novela posee constantes alusiones al silencio, las cuales, sumadas a la
ausencia de diálogos que reproduzcan las voces de los personajes, nos llevan a considerar, más
allá todavía, que el silencio configura un tema en sí mismo dentro de El monstruo de Manzanares
y determina notoriamente el sentido final de la novela
Evaluación de los factores determinantes del recuento de plaquetas en pacientes con cirrosis
Thrombocytopenia is considered one of the hallmarks of patients with cirrhosis. Several mechanisms have been implicated in the pathophysiology of thrombocytopenia in cirrhosis. Hypersplenism caused by splenomegay, classically regarded as an indirect marker of portal hypertension has been considered the main factor implicated [200]. Nevertheless, portal hypertension is best estimated by the hepatic venous pressure gradient (HVPG) [32, 189], although contradictory results have been reported regarding the association between HVPG and platelet count [195-197]. The identification of thrombopoietin (TPO), a growth factor that enhances the maturation of megakaryocytes and the release of platelets from the bone marrow, has shed new light on the physiolgy of platelets [217]. In normal conditions in adults, TPO is mainly produced in the liver [93, 96] and the circulating leves of platelets are controlled by a negative feedback mechanism [99], so there is an inverse relationship between the amount of circulating platelets, and the amount of TPO that can reach the bone marrow to stimulate thrombopoiesis. In liver cirrhosis perhaps a decreased syntehesis of TPO could be implicated in the development of thrombocytopenia. Controversial findings regarding the role of each mechanism in thrombocytopenia of liver cirrhosis have been reported [142, 146, 160-161, 184] and no study has simultaneously evaluated the influence of the different mechanisms including portal hypertension and TPO production nor whether their influence could change in different stages of the disease..
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Behavior Mining for Recommendation
In the era of information explosion, recommender systems are crucial for mitigating user information overload by filtering out irrelevant information and suggesting preferred items or content. The effectiveness of these systems hinges on accurately understanding user prefer- ences through the analysis of vast user behavior records. However, several challenges hinder the optimal performance of recommender systems. Notably, cold-start problems and noise within user behavior records significantly hinder learning user behavior patterns and develop- ing effective recommendation models. Additionally, over-smoothing issues inherent in common recommender system architectures further complicate the creation of intelligent recommender systems. This thesis is articulated through the discussion of four published papers and one paper under review, each addressing these impediments from different perspectives. The first paper tackles cold-start issues through the integration of knowledge graphs, and proposes a learnable sampling strategy to mitigate noise interference from these graphs. The second paper addresses noise in sequential recommendation scenarios via employing Variational Autoencoders (VAEs) to directly capture noise and uncertainty. The third paper overcomes cold-start difficulties by leveraging the knowledge embedded in pretrained large language models, along with a focused capture of user intent dynamics. The fourth paper confronts over-smoothing by incorporating diffusion models into the recommendation processes. Finally, the fifth paper takes a novel approach by utilizing the emergent capabilities of large language models for few-shot inference, offering a broad spectrum approach to the prevailing issues discussed
Seasonal variations of gross primary production (GPP) at the two sites.
<p>GPP was averaged for each 8-day period according to time stamp of MODIS FPAR. Only “good” GPP values (at most, 25% of half-hourly GPP values gap-filled) are shown.</p
Relationships between light use efficiency (LUE) and EF and AET/PET at the two sites.
<p>EF (evaporative fraction) is ratio of latent heat flux to available energy (LE+H); AET/PET is ratio of actual evapotranspiration to potential evapotranspiration, calculated using the Penman-Monteith equation.</p
Pearson correlation analysis between 8-day averages or sums of LUE and environmental factors at each site.
<p>TS: typical steppe; DS: desert steppe; T<sub>min</sub>: minimum temperature (°C); T<sub>a</sub>: average temperature (°C); T<sub>s5</sub>: soil temperature at 5 cm depth (°C); VPD: vapor pressure deficit (kPa); SWC<sub>10</sub>: soil water content at 10 cm depth (m<sup>3</sup> m<sup>−3</sup>); AET: actual evapotranspiration (mm); PET: potential evapotranspiration calculated using Penman-Monteith equation (mm); EF: evaporative fraction; AET/PET: the ratio of actual evapotranspiration to potential evapotranspiration; PRECP, precipitation (mm).</p><p><i>R<sup>2</sup></i> is determination coefficient; <i>n</i> is sample number.</p>*<p><i>P</i><0.05;</p>**<p><i>P</i><0.01.</p
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