3,430 research outputs found
Dijet resonance from leptophobic Z' and light baryonic cold dark matter
In light of the recent CDF report on the excess in the Wjj channel, we
analyze (non)supersymmetric U(1)_B x U(1)_L model, interpreting the dijet peak
as a leptophobic U(1)_B gauge boson. If this excess is confirmed, it has an
interesting implication for the baryonic cold dark matter (CDM) in the model:
there should be light CDM with a few GeV mass, and direct detection cross
section at the level of a few x 10^{-2} pb.Comment: 5 pages, 3 figures, version published in Phys. Lett.
Understanding and Improving In-Context Learning on Vision-language Models
Recently, in-context learning (ICL) on large language models (LLMs) has
received great attention, and this technique can also be applied to
vision-language models (VLMs) built upon LLMs. These VLMs can respond to
queries by conditioning responses on a series of multimodal demonstrations,
which comprise images, queries, and answers. Though ICL has been extensively
studied on LLMs, its research on VLMs remains limited. The inclusion of
additional visual information in the demonstrations motivates the following
research questions: which of the two modalities in the demonstration is more
significant? How can we select effective multimodal demonstrations to enhance
ICL performance? This study investigates the significance of both visual and
language information. Our findings indicate that ICL in VLMs is predominantly
driven by the textual information in the demonstrations whereas the visual
information in the demonstrations barely affects the ICL performance.
Subsequently, we provide an understanding of the findings by analyzing the
model information flow and comparing model inner states given different ICL
settings. Motivated by our analysis, we propose a simple yet effective
approach, termed Mixed Modality In-Context Example Selection (MMICES), which
considers both visual and language modalities when selecting demonstrations and
shows better ICL performance. Extensive experiments are conducted to support
our findings, understanding, and improvement of the ICL performance of VLMs.Comment: 8 pages, 10 figure
Design, Synthesis, and Characterization of Brequinar Conjugates as Probes to Study DHODH Inhibition
Brequinar, a potent dihydroorotate dehydrogenase (DHODH) inhibitor, has been evaluated in multiple clinical trials as a potential treatment for cancer. To further understand brequinar‐based DHODH inhibition and DHODH′s therapeutic relevance in cancer, we have developed novel brequinar‐based probes. We disclose a 16‐step convergent synthesis of the first brequinar‐PROTAC and a four‐step approach towards the first mitochondrial‐directed brequinar probe. A PROTAC and mitochondria‐directed probe of brequinar both possess cytotoxicity that is superior to brequinar in a colony formation assay.Brequin′ news: A novel convergent synthesis of brequinar‐based probes to induce protein degradation (16 steps) and improve mitochondria accumulation (four steps) is disclosed.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138895/1/chem201702999_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/138895/2/chem201702999-sup-0001-misc_information.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/138895/3/chem201702999.pd
Pure Leptonic Gauge Symmetry, Neutrino Masses and Dark Matter
A possible extension of the Standard Model to include lepton number as local
gauge symmetry is investigated. In such a model, anomalies are canceled by two
extra fermions doublet. After leptonic gauge symmetry spontaneously broken,
three active neutrinos may acquire non-zero Majorana masses through the
modified Type-II seesaw mechanism. Constraints on the model from electro-weak
precision measurements are studied. Due to the discrete flavor symmetry,
right-handed Majorana neutrinos can serve as cold dark matter candidate of the
Universe. Constraint from dark matter relic abundance is calculated.Comment: 13 pages, 2 figures; typos corrected, comments and references added,
to appear in Phys. Lett.
Magnetic Reversal on Vicinal Surfaces
We present a theoretical study of in-plane magnetization reversal for vicinal
ultrathin films using a one-dimensional micromagnetic model with
nearest-neighbor exchange, four-fold anisotropy at all sites, and two-fold
anisotropy at step edges. A detailed "phase diagram" is presented that catalogs
the possible shapes of hysteresis loops and reversal mechanisms as a function
of step anisotropy strength and vicinal terrace length. The steps generically
nucleate magnetization reversal and pin the motion of domain walls. No sharp
transition separates the cases of reversal by coherent rotation and reversal by
depinning of a ninety degree domain wall from the steps. Comparison to
experiment is made when appropriate.Comment: 12 pages, 8 figure
A mixed‐method systematic review of the effectiveness and acceptability of preoperative psychological preparation programmes to reduce paediatric preoperative anxiety in elective surgery
Aim
To explore the effectiveness of preoperative psychological preparation programmes aimed to reduce paediatric preoperative anxiety and the potential factors that could have an impact on parent and children's acceptance of such interventions.
Background
Various preoperative psychological preparation programmes are available to address paediatric preoperative anxiety. No mixed‐method review has been conducted to explore the effectiveness and acceptability of these programmes.
Design
A mixed‐method systematic review.
Data sources
Seven bibliographic databases were searched from inception to September 2016, complemented by hand searching of key journals, the reference lists of relevant reviews, search for grey literature and the contacting of associated experts.
Review methods
The review process was conducted based on the framework developed by the Evidence for Policy and Practice Information and Co‐ordinating Centre. A narrative summary and a thematic synthesis were developed to synthesise the quantitative and qualitative data respectively, followed by a third synthesis to combine the previous syntheses.
Results
Nineteen controlled trials and eleven qualitative studies were included for data synthesis. The controlled trials reveal that educational multimedia applications and web‐based programmes may reduce paediatric preoperative anxiety, while the effectiveness of therapeutic play and books remains uncertain. Qualitative studies showed parent‐child dyads seek different levels of information.
Conclusions
Providing matched information provision to each parent and child, actively involving children and their parents and teaching them coping skills, may be the essential hallmarks of a successful preoperative psychological preparation. Further research is necessary to confirm the effectiveness of therapeutic play and books
Spin and Chirality Effects in Antler-Topology Processes at High Energy Colliders
We perform a model-independent investigation of spin and chirality
correlation effects in the antler-topology processes
at high energy colliders with polarized
beams. Generally the production process
can occur not only through the -channel exchange of vector bosons,
, including the neutral Standard Model (SM) gauge bosons,
and , but also through the - and -channel exchanges of new
neutral states, and , and the -channel
exchange of new doubly-charged states, . The general set of
(non-chiral) three-point couplings of the new particles and leptons allowed in
a renormalizable quantum field theory is considered. The general spin and
chirality analysis is based on the threshold behavior of the excitation curves
for pair production in collisions with
longitudinal and transverse polarized beams, the angular distributions in the
production process and also the production-decay angular correlations. In the
first step, we present the observables in the helicity formalism. Subsequently,
we show how a set of observables can be designed for determining the spins and
chiral structures of the new particles without any model assumptions. Finally,
taking into account a typical set of approximately chiral invariant scenarios,
we demonstrate how the spin and chirality effects can be probed experimentally
at a high energy collider.Comment: 50 pages, 14 figures, 6 tables, matches version published in EPJ
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