4,003 research outputs found
Parallel repetition for entangled k-player games via fast quantum search
We present two parallel repetition theorems for the entangled value of
multi-player, one-round free games (games where the inputs come from a product
distribution). Our first theorem shows that for a -player free game with
entangled value , the -fold repetition of
has entangled value at most , where is the answer length of any
player. In contrast, the best known parallel repetition theorem for the
classical value of two-player free games is , due to Barak, et al. (RANDOM 2009). This
suggests the possibility of a separation between the behavior of entangled and
classical free games under parallel repetition.
Our second theorem handles the broader class of free games where the
players can output (possibly entangled) quantum states. For such games, the
repeated entangled value is upper bounded by . We also show that the dependence of the exponent
on is necessary: we exhibit a -player free game and such
that .
Our analysis exploits the novel connection between communication protocols
and quantum parallel repetition, first explored by Chailloux and Scarpa (ICALP
2014). We demonstrate that better communication protocols yield better parallel
repetition theorems: our first theorem crucially uses a quantum search protocol
by Aaronson and Ambainis, which gives a quadratic speed-up for distributed
search problems. Finally, our results apply to a broader class of games than
were previously considered before; in particular, we obtain the first parallel
repetition theorem for entangled games involving more than two players, and for
games involving quantum outputs.Comment: This paper is a significantly revised version of arXiv:1411.1397,
which erroneously claimed strong parallel repetition for free entangled
games. Fixed author order to alphabetica
Physical Randomness Extractors: Generating Random Numbers with Minimal Assumptions
How to generate provably true randomness with minimal assumptions? This
question is important not only for the efficiency and the security of
information processing, but also for understanding how extremely unpredictable
events are possible in Nature. All current solutions require special structures
in the initial source of randomness, or a certain independence relation among
two or more sources. Both types of assumptions are impossible to test and
difficult to guarantee in practice. Here we show how this fundamental limit can
be circumvented by extractors that base security on the validity of physical
laws and extract randomness from untrusted quantum devices. In conjunction with
the recent work of Miller and Shi (arXiv:1402:0489), our physical randomness
extractor uses just a single and general weak source, produces an arbitrarily
long and near-uniform output, with a close-to-optimal error, secure against
all-powerful quantum adversaries, and tolerating a constant level of
implementation imprecision. The source necessarily needs to be unpredictable to
the devices, but otherwise can even be known to the adversary.
Our central technical contribution, the Equivalence Lemma, provides a general
principle for proving composition security of untrusted-device protocols. It
implies that unbounded randomness expansion can be achieved simply by
cross-feeding any two expansion protocols. In particular, such an unbounded
expansion can be made robust, which is known for the first time. Another
significant implication is, it enables the secure randomness generation and key
distribution using public randomness, such as that broadcast by NIST's
Randomness Beacon. Our protocol also provides a method for refuting local
hidden variable theories under a weak assumption on the available randomness
for choosing the measurement settings.Comment: A substantial re-writing of V2, especially on model definitions. An
abstract model of robustness is added and the robustness claim in V2 is made
rigorous. Focuses on quantum-security. A future update is planned to address
non-signaling securit
Quantum-Proof Extractors: Optimal up to Constant Factors
We give the first construction of a family of quantum-proof extractors that has optimal seed
length dependence O(log(n/Ç«)) on the input length n and error Ç«. Our extractors support any
min-entropy k = Ω(log n + log1+α
(1/ǫ)) and extract m = (1 − α)k bits that are ǫ-close to uniform,
for any desired constant α > 0. Previous constructions had a quadratically worse seed length or
were restricted to very large input min-entropy or very few output bits.
Our result is based on a generic reduction showing that any strong classical condenser is automatically
quantum-proof, with comparable parameters. The existence of such a reduction for
extractors is a long-standing open question; here we give an affirmative answer for condensers.
Once this reduction is established, to obtain our quantum-proof extractors one only needs to consider
high entropy sources. We construct quantum-proof extractors with the desired parameters
for such sources by extending a classical approach to extractor construction, based on the use of
block-sources and sampling, to the quantum setting.
Our extractors can be used to obtain improved protocols for device-independent randomness
expansion and for privacy amplification
Small molecule-mediated tribbles homolog 3 promotes bone formation induced by bone morphogenetic protein-2.
Although bone morphogenetic protein-2 (BMP2) has demonstrated extraordinary potential in bone formation, its clinical applications require supraphysiological milligram-level doses that increase postoperative inflammation and inappropriate adipogenesis, resulting in well-documented life-threatening cervical swelling and cyst-like bone formation. Recent promising alternative biomolecular strategies are toward promoting pro-osteogenic activity of BMP2 while simultaneously suppressing its adverse effects. Here, we demonstrated that small molecular phenamil synergized osteogenesis and bone formation with BMP2 in a rat critical size mandibular defect model. Moreover, we successfully elicited the BMP2 adverse outcomes (i.e. adipogenesis and inflammation) in the mandibular defect by applying high dose BMP2. Phenamil treatment significantly improves the quality of newly formed bone by inhibiting BMP2 induced fatty cyst-like structure and inflammatory soft-tissue swelling. The observed positive phenamil effects were associated with upregulation of tribbles homolog 3 (Trib3) that suppressed adipogenic differentiation and inflammatory responses by negatively regulating PPARγ and NF-κB transcriptional activities. Thus, use of BMP2 along with phenamil stimulation or Trib3 augmentation may be a promising strategy to improve clinical efficacy and safety of current BMP therapeutics
Metagenomic characterization of the cecal microbiota community and functions in finishing pigs fed fermented Boehmeria nivea
Ramie (Boehmeria nivea, BN) is used as livestock forage through suitable silage fermentation owing to its nutritional value. To date, relatively few studies have investigated the effects of dietary fermented BN (FBN) on gut health in finishing pigs. The aim of the present study was to investigate the effects of dietary supplementation with 20% FBN on intestinal morphology, gene expression, and the functional response of the gut microbiota in finishing pigs. We found that FBN did not significantly affect serum antioxidant enzyme activities, ileal morphology, or the expression of genes encoding antioxidant enzymes, inflammatory cytokines, or tight junction proteins in the liver of the pigs. However, the gene expression levels of aryl hydrocarbon receptor (AHR) and interleukin 6 (IL6) were significantly downregulated in the ileum. A metagenomic analysis demonstrated that, compared with that seen in the control group, the cecal microbiota of pigs in the FBN treatment group was more closely clustered and contained a greater number of unique microbes. Bacteria were the predominant kingdom in the cecal microbiota, while Firmicutes, Bacteroidetes, and Proteobacteria were the dominant phyla, and Streptococcus, Lactobacillus, and Prevotella were the dominant genera. Dietary FBN significantly increased the abundance of the probiotic bacterium Roseburia inulinivorans (p < 0.05). Functional analysis of the cecal microbiota showed that ABC transporter levels and glycolysis/gluconeogenesis-associated functions were diminished in FBN-fed pigs. Meanwhile, CAZyme analysis revealed that dietary FBN significantly downregulated the contents of carbohydrate-active enzymes, such as GT2, GH1, GH25, and GH13_31. In addition, cytochrome P450 analysis revealed that the abundance of CYP51 and CYP512 decreased with FBN treatment. An assessment of antibiotic resistance based on the Comprehensive Antibiotic Resistance Database (CARD) annotation indicated that the cecal microbes from pigs in the FBN treatment group had increased resistance to lincosamide, streptogramin, and chloramphenicol and reduced resistance to amikacin, isepamicin, neomycin, lividomycin, gentamicin, paromomycin, ribostamycin, and butirosin. Finally, virulence factor-related analysis showed that putative hemolysin-associated functions were decreased, whereas fibronectin-binding protein, flagella, and alginate-associated functions were increased. Taken together, our data showed that FBN supplementation exerted only minor effects on intestinal morphology and microbial community composition, suggesting that it is potentially safe for use as a supplement in the diets of finishing pigs. However, more studies are needed to validate its functionality
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