Tsafrir Kolatt

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Blood oxygenation level dependence (BOLD) imaging under either hypercapnia or hyperoxia has been used to study neuronal activation and for assessment of various brain pathologies. We evaluated the benefit of a combined protocol of BOLD imaging during both hyperoxic and hypercapnic challenges (termed hemodynamic response imaging (HRI)). Nineteen healthy(More)
In this paper, we address the problem of fully automated decomposition of hyperspectral images for transmission light microscopy. The hyperspectral images are decomposed into spectrally homogeneous compounds. The resulting compounds are described by their spectral characteristics and optical density. We present the multiplicative physical model of image(More)
Singing is, undoubtedly, the most fundamental expression of our musical capacity, yet an estimated 10-15% of Western population sings "out-of-tune (OOT)." Previous research in children and adults suggests, albeit inconsistently, that imitating a human voice can improve pitch matching. In the present study, we focus on the potentially beneficial effects of(More)
This paper introduces the formalism for the connection between rotation measure (RM) measurements for extragalactic sources and the cosmological magnetic field power spectrum. It is shown that by using a few hundred radio sources, for which Faraday RMs are available, the amplitude and shape of the cosmological magnetic field power spectrum are constrained.(More)
We use N-body simulations combined with semi-analytic models to compute the clustering properties of modeled galaxies at z ∼ 3, and confront these predictions with the clustering properties of the observed population of Lyman-break galaxies (LBGs). Several scenarios for the nature of LBGs are explored, which may be broadly categorized into models in which(More)
A combined sample of 79 high and low redshift supernovae Ia (SNe) is used to set constraints on the degree of anisotropy in the Universe out to z ≃ 1. First we derive the global most probable values of matter density Ω M , the cosmological constant Ω Λ , and the Hubble constant H 0 , and find them to be consistent with the published results from the two(More)
We describe the construction of an N-body simulation that mimics the true velocity and mass-density elds in a box of side 256 h 1 Mpc about the Local Group, and the production of mock catalogs that mimic in detail current catalogs of redshifts and peculiar velocities. Our main purpose is to provide a tool for developing and testing reconstruction methods,(More)
We present a new method to determine Υ HI , the total mass-to-neutral gas ratio in Lyman-limits systems. The method exploits the relation between the neutral hydrogen column density and the magnification of background sources due to the weak gravita-tional lensing that these systems induce. Because weak lensing does not provide a direct measure of mass, one(More)
Spatiotemporal variations in attributes of particulate matter (PM) in ambient air are important estimates of environmental pollution and public health risks. In particularly, the exposure to fine PM, with count mean diameters of less than 4µm, has been associated with undesirable health effects. Therefore, methodologies that analyze the size profiles of(More)