126 research outputs found
Tensor Norms and the Classical Communication Complexity of Nonlocal Quantum Measurement
We initiate the study of quantifying nonlocalness of a bipartite measurement
by the minimum amount of classical communication required to simulate the
measurement. We derive general upper bounds, which are expressed in terms of
certain tensor norms of the measurement operator. As applications, we show that
(a) If the amount of communication is constant, quantum and classical
communication protocols with unlimited amount of shared entanglement or shared
randomness compute the same set of functions; (b) A local hidden variable model
needs only a constant amount of communication to create, within an arbitrarily
small statistical distance, a distribution resulted from local measurements of
an entangled quantum state, as long as the number of measurement outcomes is
constant.Comment: A preliminary version of this paper appears as part of an article in
Proceedings of the the 37th ACM Symposium on Theory of Computing (STOC 2005),
460--467, 200
Quantum Communication Complexity and Nonlocality of Bipartite Quantum Operations.
This dissertation is motivated by the following fundamental questions: (a) are
there any exponential gaps between quantum and classical communication complexities?
(b) what is the role of entanglement in assisting quantum communications? (c)
how to characterize the nonlocality of quantum operations? We study four specific
problems below.
1. The communication complexity of the Hamming Distance problem. The
Hamming Distance problem is for two parties to determine whether or not the
Hamming distance between two n-bit strings is more than a given threshold. We
prove tighter quantum lower bounds in the general two-party, interactive communication
model. We also construct an efficient classical protocol in the more restricted
Simultaneous Message Passing model, improving previous results.
2. The Log-Equivalence Conjecture. A major open problem in communication
complexity is whether or not quantum protocols can be exponentially more efficient
than classical ones for computing a total Boolean function in the two-party, interactive
model. The answer is believed to be No. Razborov proved this conjecture
for the most general class of functions so far. We prove this conjecture for a broader
class of functions that we called block-composed functions. Our proof appears to be
the first demonstration of the dual approach of the polynomial method in proving
new results.
3. Classical simulations of bipartite quantum measurement. We define a new
ix
concept that measures the nonlocality of bipartite quantum operations. From this
measure, we derive an upper bound that shows the limitation of entanglement in
reducing communication costs.
4. The maximum tensor norm of bipartite superoperators. We define a maximum
tensor norm to quantify the nonlocality of bipartite superoperators. We show
that a bipartite physically realizable superoperator is bi-local if and only if its maximum
tensor norm is 1. Furthermore, the estimation of the maximum tensor norm
can also be used to prove quantum lower bounds on communication complexities.Ph.D.Computer Science & EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/58538/1/yufanzhu_1.pd
Trifolirhizin relieves renal injury in a diabetic nephropathy model by inducing autophagy and inhibiting oxidative stress through the regulation of PI3K/AKT/mTOR pathway
Purpose: To evaluate the effects of trifolirhizin on diabetic nephropathy (DN), and the mechanism of action.
Methods: Male db/db mice (8 weeks, n = 24) and age-matched control mice (n = 6) were obtained. The mice were further divided into four groups and administered increasing doses of trifolirhizin (0, 12.5, 25 and 50 mg/kg). Histological analysis of renal tissues were performed by H & E staining. Blood urea nitrogen (BUN) and creatinine were determined using enzyme-linked immunosorbent assay (ELISA). Immunoblot and TUNEL assay were performed to investigate the effect of trifolirhizin on autophagy and apoptosis, while ELISA and dihydroethidium (DHE) staining were conducted to evaluate reactive oxygen species (ROS), malondialdehyde (MDA) and superoxide dismutase (SOD) levels. The effect of trifolirhizin on PI3K/AKT/mTOR pathway was determined using Immunoblot assays.
Results: Trifolirhizin alleviated renal injury in diabetic mice, and also activate autophagy and inhibited apoptosis in the renal tissues in diabetic mice (p < 0.001). In addition, trifolirhizin inhibited the oxidative stress response in the renal tissue in diabetic mice (p < 0.001). Trifolirhizin further inhibited PI3K/AKT/mTOR pathway and therefore relieved renal injury in the diabetic nephropathy model (p < 0.001).
Conclusion: Trifolirhizin alleviates renal injury in diabetic mice, activates autophagy, and inhibits apoptosis in renal tissue of diabetic mice. Therefore, trifolirhizin is a promising a promising drug for the treatment of DN
The Communication Complexity of the Hamming Distance Problem
We investigate the randomized and quantum communication complexity of the
Hamming Distance problem, which is to determine if the Hamming distance between
two n-bit strings is no less than a threshold d. We prove a quantum lower bound
of \Omega(d) qubits in the general interactive model with shared prior
entanglement. We also construct a classical protocol of O(d \log d) bits in the
restricted Simultaneous Message Passing model, improving previous protocols of
O(d^2) bits (A. C.-C. Yao, Proceedings of the Thirty-Fifth Annual ACM Symposium
on Theory of Computing, pp. 77-81, 2003), and O(d\log n) bits (D. Gavinsky, J.
Kempe, and R. de Wolf, quant-ph/0411051, 2004).Comment: 8 pages, v3, updated reference. to appear in Information Processing
Letters, 200
Shifted Diffusion for Text-to-image Generation
We present Corgi, a novel method for text-to-image generation. Corgi is based
on our proposed shifted diffusion model, which achieves better image embedding
generation from input text. Unlike the baseline diffusion model used in DALL-E
2, our method seamlessly encodes prior knowledge of the pre-trained CLIP model
in its diffusion process by designing a new initialization distribution and a
new transition step of the diffusion. Compared to the strong DALL-E 2 baseline,
our method performs better in generating image embedding from the text in terms
of both efficiency and effectiveness, resulting in better text-to-image
generation. Extensive large-scale experiments are conducted and evaluated in
terms of both quantitative measures and human evaluation, indicating a stronger
generation ability of our method compared to existing ones. Furthermore, our
model enables semi-supervised and language-free training for text-to-image
generation, where only part or none of the images in the training dataset have
an associated caption. Trained with only 1.7% of the images being captioned,
our semi-supervised model obtains FID results comparable to DALL-E 2 on
zero-shot text-to-image generation evaluated on MS-COCO. Corgi also achieves
new state-of-the-art results across different datasets on downstream
language-free text-to-image generation tasks, outperforming the previous
method, Lafite, by a large margin
Regulatory role of excitatory interneurons by combining electrical stimulation for absence seizures in the coupled thalamocortical model
The role of excitatory interneurons (EINs) in the cortical has received increasing attention in the discussion of absence seizures. Numerous physiological experiments have confirmed the correlation between EIN and absence seizures. However, the dynamic mechanisms underlying this relationship are not well understood, and there are some challenges in selecting appropriate stimulation strategies for pyramidal clusters. In this study, we incorporated EIN into the previous Taylor model and developed an improved thalamocortical coupled model consisting of ten neuronal populations. Initially, we investigated the excitatory induction effect of EIN to pyramidal clusters and the external input of EIN. Then, four different targeted treatment approaches (deep brain stimulation (DBS), current balanced biphasic pulse (CBBP), 1:0 coordinated resetting stimulation (1:0 CRS), and 3:2 CRS) were applied to the pyramidal clusters. Moreover, we established two quantitative indices to evaluate the stimulation effects. The results showed that modifying the external input of EIN and the coupling strength projected onto the pyramidal clusters can effectively transition the system from an absence seizure state to other normal states. Additionally, inputs from the left compartment were found to reduce the generation of abnormal discharge regions in the right compartment. Furthermore, considering the treatment effects and current consumption, the 3:2 CRS stimulation strategy appeared to be the most suitable treatment approach for the pyramidal clusters. This work introduces a novel coupled model containing EIN, which contributes new theoretical foundations and insights for the future treatment of absence seizures
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