50,611 research outputs found
Revisiting B_s\to\mu^+\mu^- and B\to K^{(*)}\mu^+\mu^- decays in the MSSM with and without R-parity
The rare decays B_s -> \mu^+\mu^- and B -> K^{(*)}\mu^+\mu^- are sensitive to
new particles and couplings via their interferences with the standard model
contributions. Recently, the upper bound on B(B_s -> \mu^+\mu^-) has been
improved significantly by the CMS, LHCb, CDF, and D{\O} experiments. Combining
with the measurements of B(B-> K^{(*)}\mu^+\mu^-), we derive constraints on the
relevant parameters of minimal supersymmetic standard model with and without
R-parity, and examine their contributions to the dimuon forward-backward
asymmetry in B-> K^{*}\mu^+\mu^- decay. We find that (i) the contribution of
R-parity violating coupling products
\lambda^{\prime}_{2i2}\lambda^{\prime*}_{2i3} due to squark exchange is
comparable with the theoretical uncertainties in B-> K \mu^+\mu^- decay, but
still could be significant in B-> K^{*}\mu^+\mu^- decay and could account for
the forward-backward asymmetry in all dimuon invariant mass regions; (ii) the
constrained mass insertion (\delta^{u}_{LL})_{23} could have significant
contribution to dA_{FB}(B-> K^{*}\mu^+\mu^-)/ds, and such effects are favored
by thr recent results of the Belle, CDF, and LHCb experiments.Comment: 20 pages, 9 figures, published versio
Behind the rainbow, "Tongqi" wives of men who have sex with men in China: a systematic review
open access articleBackground: Due to the restrictions and stigmatization of homosexuality in China, there has emerged the “Tongqi,” or the wives of men who have sex with men (MSM). There are around 14 million Tongqi wives whose needs for support are often overshadowed. This phenomenon has been largely under researched, this review is the first to address the current data on the Tongqi. The aim of this systematic review is to begin to provide insight into the pre-existing data and the further support that is needed for the wives of MSM.
Methods: The researchers searched PubMed, Web of Science, EMBASE, PsycINFO, CNKI, Sinomed and WangFang databases from their inception date until June 7, 2019. Handsearching was also completed to provide a rich data set.
Results: The articles were summarized and analyzed for thematic clusters. From the selected article, five themes emerged, including Sexual Health Issues, Intimate Partner Violence, Mental Health Status, Marriage Dissatisfaction, and Coping Strategies. These themes often intersected to provide a complex understanding of the current gaps in support provided to Tongqi.
Conclusion: Tongqi wives remain a hidden population in Chinese mainstream society, who deserves a sensitive approach to support. The study revealed that the MSM wives suffer severe mental, physical, health, and life related harms. However, instead of situating them into the victim roles, many women take on an identity of empowerment and are working together, aiming to make social changes. In order to address the Tongqi phenomenon, it is also essential to reduce the discrimination toward homosexuality. Tongqi are a special group of Chinese women, they require further intensive research attention
Time-domain reconstruction algorithms and numerical simulations for thermoacoustic tomography in various geometries
In this paper, we present time-domain reconstruction algorithms for the thermoacoustic imaging of biological tissues. The algorithm for a spherical measurement configuration has recently been reported in another paper. Here, we extend the reconstruction algorithms to planar and cylindrical measurement configurations. First, we generalize the rigorous reconstruction formulas by employing Green's function technique. Then, in order to detect small (compared with the measurement geometry) but deeply buried objects, we can simplify the formulas when two practical conditions exist: 1) that the high-frequency components of the thermoacoustic signals contribute more to the spatial resolution than the low-frequency ones, and 2) that the detecting distances between the thermoacoustic sources and the detecting transducers are much greater than the wavelengths of the high-frequency thermoacoustic signals (i.e., those that are useful for imaging). The simplified formulas are computed with temporal back projections and coherent summations over spherical surfaces using certain spatial weighting factors. We refer to these reconstruction formulas as modified back projections. Numerical results are given to illustrate the validity of these algorithms
Effects of acoustic heterogeneity on the breast thermoacoustic tomography
The effects of wavefront distortions induced by acoustic heterogeneities in breast thermoacoustic tomography (TAT) are studied. First, amplitude distortions are shown to be insignificant for different scales of acoustic heterogeneities. Next, the effects of phase distortions (errors in time-of-flight) in our numerical studies are investigated, and the spreads of point sources and boundaries caused by the phase distortions are studied. After that, a demonstration showing that the blurring of images can be compensated for by using the distribution of acoustic velocity in the tissues in the reconstructions is presented. Last, the differences in the effects of acoustic heterogeneity and the generation of speckles in breast TAT and breast ultrasound imaging are discussed
Rhesus monkey brain imaging through intact skull with thermoacoustic tomography
Two-dimensional microwave-induced thermoacoustic tomography (TAT) is applied to imaging the Rhesus monkey brain through the intact skull. To reduce the wavefront distortion caused by the skull, only the low-frequency components of the thermoacoustic signals (< 1 MHz) are used to reconstruct the TAT images. The methods of signal processing and image reconstruction are validated by imaging a lamb kidney. The resolution of the system is found to be 4 mm when we image a 1-month-old monkey head containing inserted needles. We also image the coronal and axial sections of a 7-month-old monkey head. Brain features that are 3 cm deep in the head are imaged clearly. Our results demonstrate that TAT has potential for use in portable, cost-effective imagers for pediatric brains
Application of time reversal to thermoacoustic tomography
Reconstruction for thermoacoustic tomography in an arbitrary detection geometry is proposed by time-reversing the measured field back to the time when the thermoacoustic sources are excited. Time reversal of the field can be implemented efficiently by applying the delay-and-sum algorithm. The theoretical conclusions are supported by a numerical simulation of three-dimensional thermoacoustic tomography
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