126 research outputs found
On the equivalence principle and gravitational and inertial mass relation of classical charged particles
We show that the locally constant force necessary to get a stable hyperbolic
motion regime for classical charged point particles, actually, is a combination
of an applied external force and of the electromagnetic radiation reaction
force. It implies, as the strong Equivalence Principle is valid, that the
passive gravitational mass of a charged point particle should be slight greater
than its inertial mass. An interesting new feature that emerges from the
unexpected behavior of the gravitational and inertial mass relation, for
classical charged particles, at very strong gravitational field, is the
existence of a critical, particle dependent, gravitational field value that
signs the validity domain of the strong Equivalence Principle. For electron and
proton, these critical field values are
and , respectively
Tempo de tunelamento de um pacote de ondas gaussiano na região de uma barreira de potencial retangular
Dentro da temática do tempo de tunelamento, utilizando o método da fase estacionária, examinamos o tempo de trânsito de um pacote de ondas na região de uma barreira de potencial retangular. O pacote de ondas incidente é construído a partir de uma distribuição gaussiana de momentos. O tempo de trânsito obtido é livre das contribuições devidas às perturbações causadas pelas interferências na região imediatamente anterior à barreira de potencial. Mede o tempo de propagação do pacote de ondas através da região do potencial a partir da sua emergência no início da barreira até a sua chegada ao final da mesma, dentro dos procedimentos do método da fase estacionária
Adaptive Data Transmission Control for Spatio-temporal Data Retention over Crowds of Vehicles
Some specific services for Internet of Things, such as real-time map and providing local weather information, depend strongly on geographical time and location. We refer to the data for such service as spatio-temporal data (STD). When STD is used in a query response system similar to conventional Internet services, users not only need to acquire data actively as required, they must also have functions for retrieving data available STD. Therefore, we propose an STD retention system that uses vehicles as information hubs (InfoHubs) for disseminating and retaining the data in a specific area. In our system, InfoHubs diffuse, maintain, and advertise STD over places and times where the STD are strongly dependent, thereby allowing users to receive such data passively within the specific area. Additionally, because STD are associated with a particular space, the system can reduce search costs. We also propose an adaptive transmission control method that each vehicle effectively operates its wireless resources autonomously and STD are retained and distributed efficiently. Finally, we evaluated our proposed method using simulations and clarified that our proposed system is capable of achieving a coverage rate of nearly 100% for STD while reducing the number of data transmissions compared to existing systems
Resonant structure of low-energy H3+ dissociative recombination
New high-resolution dissociative recombination rate coefficients of
rotationally cool and hot H3+ in the vibrational ground state have been
measured with a 22-pole trap setup and a Penning ion source, respectively, at
the ion storage ring TSR. The experimental results are compared with
theoretical calculations to explore the dependence of the rate coefficient on
ion temperature and to study the contributions of different symmetries to probe
the rich predicted resonance spectrum. The break-up energy was investigated by
fragment imaging to derive internal temperatures of the stored parent ions
under differing experimental conditions. A systematic experimental assessment
of heating effects is performed which, together with a survey of other recent
storage-ring data, suggests that the present rotationally cool rate-coefficient
measurement was performed at 380^{+50}_{-130} K and that this is the lowest
rotational temperature so far realized in storage-ring rate-coefficient
measurements on H3+. This partially supports the theoretical suggestion that
higher temperatures than assumed in earlier experiments are the main cause for
the large gap between the experimental and theoretical rate coefficients. For
the rotationally hot rate-coefficient measurement a temperature of below 3250K
is derived. From these higher-temperature results it is found that increasing
the rotational ion temperature in the calculations cannot fully close the gap
between the theoretical and experimental rate coefficients.Comment: 12 pages, 7 figures (11 subfigures), 3 table
Treatment of doxorubicin resistant MCF7/Dx cells with nitric oxide causes histone glutathionylation and reversal of drug resistance.
Acquired drug resistance was found to be suppressed in the doxorubicin-resistant breast cancer cell line MCF7/Dx after pre-treatment with GSNO (nitrosoglutathione). The effect was accompanied by enhanced protein glutathionylation and accumulation of doxorubicin in the nucleus. Among the glutathionylated proteins, we identified three members of the histone family; this is, to our knowledge, the first time that histone glutathionylation has been reported. Formation of the potential NO donor dinitrosyl–diglutathionyl–iron complex, bound to GSTP1-1 (glutathione transferase P1-1), was observed in both MCF7/Dx cells and drug-sensitive MCF7 cells to a similar extent. In contrast, histone glutathionylation was found to be markedly increased in the resistant MCF7/Dx cells, which also showed a 14-fold higher amount of GSTP1-1 and increased glutathione concentration compared with MCF7 cells. These results suggest that the increased cytotoxic effect of combined doxorubicin and GSNO treatment involves the glutathionylation of histones through a mechanism that requires high glutathione levels and increased expression of GSTP1-1. Owing to the critical role of histones in the regulation of gene expression, the implication of this finding may go beyond the phenomenon of doxorubicin resistance
The state of the Martian climate
60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes
- …