4,625 research outputs found
Pengaruh Customer Perception, Perceived Value, Price dan Promotion terhadap Buying Decision pada Tiket Lion Air
Penelitian ini bertujuan untuk mengetahui pengaruh customer perception, perceived value, price dan promotion terhadap buying decision pada tiket Lion Air. Metode yang digunakan dalam penelitian ini yaitu metode penelitian kuantitatif. Sampel dalam penelitian ini sebanyak 100 orang responden yang diambil dengan metode purposive sampling. Analisis data akan dilakukan dengan menggunakan alat uji statistik dengan bantuan aplikasi bernama Statistical Product and Service Solutions (SPSS). Hasil penelitian menunjukkan bahwa customer perception, perceived value, price dan pro- motion berpengaruh positif dan signifikan terhadap buying decision
Fermion Soliton Stars with Asymmetric Vacua
Fermion soliton stars are a motivated model of exotic compact objects in
which a nonlinear self-interacting real scalar field couples to a fermion via a
Yukawa term, giving rise to an effective fermion mass that depends on the fluid
properties. Here we continue our investigation of this model within General
Relativity by considering a scalar potential with generic asymmetric vacua.
This case provides fermion soliton stars with a parametrically different
scaling of the maximum mass relative to the model parameters, showing that the
special case of symmetric vacua, in which we recover our previous results,
requires fine tuning. In the more generic case studied here the mass and radius
of a fermion soliton star are comparable to those of a neutron star for natural
model parameters at the GeV scale. Finally, the asymmetric scalar potential
inside the star can provide either a positive or a negative effective
cosmological constant in the interior, being thus reminiscent of gravastars or
anti-de Sitter bubbles, respectively. In the latter case we find the existence
of multiple, disconnected, branches of solutions.Comment: 9 pages, 7 figures. v2: matches version accepted in PR
Approaches to attenuated psychosis syndrome treatments: A perspective on the regulatory issues
Clinical applications of EEG power spectra aperiodic component analysis: A mini-review
Objective: The present mini-review summarizes recent clinical findings related to the analysis of the aperiodic component of EEG (electroencephalographic) power spectra, making them quickly accessible to medical specialists and health researchers, with the aim of boosting related research. Methods: Based on our experience about cliniciansā literature-searching, we queried the PubMed database with terms related to EEG power spectra aperiodic component analysis and selected clinical studies that referenced such terms in the title/abstract, and were published in the last five years. Results: A total of 11 journal articles, dealing with 9 different neurologic and psychiatric conditions published between 1st January 2016 ā April 1st 2021, were surveyed. Conclusions: All the reviewed studies focused on exploring the pathophysiological significance of the aperiodic component and its correlation with disease presence, stage, and severity. Despite the heterogeneity of pathologies, it was possible to cluster most of them according to the mechanism underlying slope alterations, namely hypo-/hyper-excitability. It was also possible to identify some counterintuitive findings, probably related to compensation mechanisms of disease-specific neurophysiological alterations. Significance: All the findings seem to support the role of the aperiodic activity as index of excitation/inhibition balance, with promising clinical applications that might challenge the traditional approach to pathologies diagnosis/treatment/follow-up
Cholesterol homeostasis: a key to prevent or slow down neurodegeneration
Neurodegeneration, a common feature for many brain disorders, has severe consequences on the mental and physical health of an individual. Typically human neurodegenerative diseases are devastating illnesses that predominantly affect elderly people, progress slowly, and lead to disability and premature death; however they may occur at all ages. Despite extensive research and investments, current therapeutic interventions against these disorders treat solely the symptoms. Therefore, since the underlying mechanisms of damage to neurons are similar, in spite of etiology and background heterogeneous, it will be of interest to identify possible trigger point of neurodegeneration enabling development of drugs and/or prevention strategies that target many disorders simultaneously. Among the factors that have been identified so far to cause neurodegeneration, failures in cholesterol homeostasis are indubitably the best investigated. The aim of this review is to critically discuss some of the main results reported in the recent years in this field mainly focusing on the mechanisms that, by recovering perturbations of cholesterol homeostasis in neuronal cells, may correct clinically relevant features occurring in different neurodegenerative disorders and, in this regard, also debate the current potential therapeutic interventions
Numerical methods for hyperbolic and parabolic integro-differential equations
An analysis by energy methods is given for fully discrete numerical methods for time-dependent partial integro-differential equations. Stability and error estimates are derived in H1 and L2. The methods considered pay attention to the storage needs during time-stepping
Dark photon superradiance quenched by dark matter
Black-hole superradiance has been used to place very strong bounds on avariety of models of ultralight bosons such as axions, new light scalars, anddark photons. It is common lore to believe that superradiance bounds arebroadly model independent and therefore pretty robust. In this work we showhowever that superradiance bounds on dark photons can be challenged by simple,compelling extensions of the minimal model. In particular, if the dark photonpopulates a larger dark sector and couples to dark fermions playing the role ofdark matter, then superradiance bounds can easily be circumvented, depending onthe mass and (dark) charge of the dark matter.<br
A multi-layer edge-on single photon counting silicon microstrip detector for innovative techniques in diagnostic radiology
A three-layer detector prototype, obtained by stacking three edge-on single photon counting silicon microstrip detectors, has been developed and widely tested. This was done in the framework of the Synchrotron Radiation for Medical Physics/Frontier Radiology (SYRMEP/FRONTRAD) collaboration activities, whose aim is to improve the quality of mammographic examinations operating both on the source and on the detector side. The active surface of the device has been fully characterized making use of an edge-scanning technique and of a well-collimated laminar synchrotron radiation beam. The obtained data (interlayer distances, channel correspondence, etc.) have then been used to combine information coming from each detector layer, without causing any loss in spatial and contrast resolution of the device. Contrast and spatial resolution have also been separately evaluated for each detector layer. Moreover, imaging techniques (phase contrast, refraction, and scatter imaging), resulting in an increased visibility of low absorbing details, have been implemented, and their effectiveness has been tested on a biological sample. Finally, the possibility of simultaneously acquiring different kind of images with the different detector layers is discussed. This would result in maximizing the information extracted from the sample, while at the same time the high absorption efficiency of the detector device would allow a low dose delivery
Effect of the (Nd,Dy)-double doping on the structural properties of ceria
The crystallographic properties of the Ce1-x(Nd0.63Dy0.37)xO2-x/2 system (0 64 x 64 0.6) were studied by means of synchrotron powder X-ray diffraction and compared to the ones of Sm-doped ceria. The aim of this work was to investigate the effect of substituting Sm3+ by a mixture of a smaller and a larger ion that ensures a more pronounced Ce4+/dopant size mismatch while having the same average ionic size as Sm3+. Two main findings came to light: (a) the compositional region of the CeO2-based solid solution widens up to x ranging between 0.4 and 0.5, and (b) the cell parameter is larger than the one of Sm-doped ceria at each composition. Both effects are expected to play a significant role on the ionic conductivity of the material. The results are discussed in terms of disorder and cation-vacancy association
Fermion soliton stars
A real scalar field coupled to a fermion via a Yukawa term can evade no-go
theorems preventing solitonic solutions. For the first time, we study this
model within General Relativity without approximations, finding static and
spherically symmetric solutions that describe fermion soliton stars. The Yukawa
coupling provides an effective mass for the fermion, which is key to the
existence of self-gravitating relativistic solutions. We systematically study
this novel family of solutions and present their mass-radius diagram and
maximum compactness, which is close to (but smaller than) that of the
corresponding Schwarzschild photon sphere. Finally, we discuss the ranges of
the parameters of the fundamental theory in which the latter might have
interesting astrophysical implications, including compact (sub)solar and
supermassive fermion soliton stars for a standard gas of degenerate neutrons
and electrons, respectively.Comment: 16 pages, 5 figure
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