669 research outputs found
Separating decision tree complexity from subcube partition complexity
The subcube partition model of computation is at least as powerful as
decision trees but no separation between these models was known. We show that
there exists a function whose deterministic subcube partition complexity is
asymptotically smaller than its randomized decision tree complexity, resolving
an open problem of Friedgut, Kahn, and Wigderson (2002). Our lower bound is
based on the information-theoretic techniques first introduced to lower bound
the randomized decision tree complexity of the recursive majority function.
We also show that the public-coin partition bound, the best known lower bound
method for randomized decision tree complexity subsuming other general
techniques such as block sensitivity, approximate degree, randomized
certificate complexity, and the classical adversary bound, also lower bounds
randomized subcube partition complexity. This shows that all these lower bound
techniques cannot prove optimal lower bounds for randomized decision tree
complexity, which answers an open question of Jain and Klauck (2010) and Jain,
Lee, and Vishnoi (2014).Comment: 16 pages, 1 figur
Motives that Mediate the Associations Between Relationship Satisfaction, Orgasmic Difficulty, and the Frequency of Faking Orgasm
INTRODUCTION: Faking orgasm by women reportedly occurs quite frequently, with both relationship characteristics and orgasmic difficulty being significant predictors. AIM: We explored women's motives that might mediate the associations between orgasmic difficulty and relationship satisfaction on the one hand, with the frequency of faking orgasm on the other. METHODS: In a study of 360 Hungarian women who reported “ever” faking orgasm during partnered sex, we assessed the direct and indirect (mediated) associations between orgasmic difficulty, relationship satisfaction, and the frequency of faking orgasm. OUTCOMES: Determination of motives that mediate the association between orgasmic difficulty and the frequency of faking orgasm, and the association between relationship satisfaction and the frequency of faking orgasm. RESULTS: Increased orgasmic difficulty was directly related to increased frequency of faking orgasm (β = 0.37; P < .001), and each variable itself was related to a number of motives for faking orgasm. However, the only motive assessed in our study that mediated the relationship between orgasmic difficulty and the frequency of faking orgasm was insecurity about being perceived as abnormal or dysfunctional (indirect effect: β = 0.13; P < .001). A similar pattern emerged with relationship satisfaction and frequency of faking orgasm. These two variables were directly related in that lower relationship satisfaction predicted higher frequency of faking orgasm (β = -0.15; P = .008). Furthermore, while each variable itself was related to a number of motives for faking orgasm, the only motive assessed in our study that mediated the relationship between the 2 variables was insecurity about being perceived as abnormal or dysfunctional (indirect effect: β = -0.06; P = .008). CLINICAL TRANSLATION: Insecurity related to being perceived as abnormal or deficient, along with sexual communication, should be addressed in women with a history of faking orgasm but who want to cease doing so. STRENGTHS AND LIMITATIONS: The sample was relatively large and the online survey adhered to best practices. Nevertheless, bias may result in sample characteristics when recruitment is achieved primarily through social media. In addition, the cross-sectional sample prevented causal determination and represented Western-based values. CONCLUSIONS: The associations between orgasmic difficulty and faking orgasm, and between relationship satisfaction and faking orgasm, are both direct and indirect (mediated). The primary motive for mediating the indirect association between the predictor variables and the frequency of faking orgasm was the insecurity about being perceived as deficient or abnormal. Hevesi K, Horvath Z, Miklos E, et al. Motives that Mediate the Associations Between Relationship Satisfaction, Orgasmic Difficulty, and the Frequency of Faking Orgasm. Sex Med 2022;10:100568
Elevated ethyl methanesulfonate (EMS) in nelfinavir mesylate (Viracept®, Roche): overview
Roche's protease inhibitor nelfinavir mesylate (Viracept®) produced between March 2007-June 2007 was found to contain elevated levels of ethyl methanesulfonate (EMS), a known mutagen (alkylator) – leading to a global recall of the drug. EMS levels in a daily dose (2,500 mg Viracept/day) were predicted not to exceed a dose of ~2.75 mg/day (~0.055 mg/kg/day based on 50 kg patient). As existing toxicology data on EMS did not permit an adequate patient risk assessment, a comprehensive animal toxicology evaluation of EMS was conducted. General toxicity of EMS was investigated in rats over 28 days. Two studies for DNA damage were performed in mice; chromosomal damage was assessed using a micronucleus assay and gene mutations were detected using the MutaMouse transgenic model. In addition, experiments designed to extrapolate animal exposure to humans were undertaken. A general toxicity study showed that the toxicity of EMS occurred only at doses ≥ 60 mg/kg/day, which is far above that received by patients. Studies for chromosomal damage and mutations in mice demonstrated a clear threshold effect with EMS at 25 mg/kg/day, under chronic dosing conditions. Exposure analysis (Cmax) demonstrated that ~370-fold higher levels of EMS than that ingested by patients, are needed to saturate known, highly conserved, error-free, mammalian DNA repair mechanisms for alkylation. In summary, animal studies suggested that patients who took nelfinavir mesylate with elevated levels of EMS are at no increased risk for carcinogenicity or teratogenicity over their background risk, since mutations are prerequisites for such downstream events. These findings are potentially relevant to >40 marketed drugs that are mesylate salts
The White-Box Adversarial Data Stream Model
We study streaming algorithms in the white-box adversarial model, where the
stream is chosen adaptively by an adversary who observes the entire internal
state of the algorithm at each time step. We show that nontrivial algorithms
are still possible. We first give a randomized algorithm for the -heavy
hitters problem that outperforms the optimal deterministic Misra-Gries
algorithm on long streams. If the white-box adversary is computationally
bounded, we use cryptographic techniques to reduce the memory of our
-heavy hitters algorithm even further and to design a number of additional
algorithms for graph, string, and linear algebra problems. The existence of
such algorithms is surprising, as the streaming algorithm does not even have a
secret key in this model, i.e., its state is entirely known to the adversary.
One algorithm we design is for estimating the number of distinct elements in a
stream with insertions and deletions achieving a multiplicative approximation
and sublinear space; such an algorithm is impossible for deterministic
algorithms.
We also give a general technique that translates any two-player deterministic
communication lower bound to a lower bound for {\it randomized} algorithms
robust to a white-box adversary. In particular, our results show that for all
, there exists a constant such that any -approximation
algorithm for moment estimation in insertion-only streams with a
white-box adversary requires space for a universe of size .
Similarly, there is a constant such that any -approximation algorithm
in an insertion-only stream for matrix rank requires space with a
white-box adversary. Our algorithmic results based on cryptography thus show a
separation between computationally bounded and unbounded adversaries.
(Abstract shortened to meet arXiv limits.)Comment: PODS 202
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Ellipsoid Localisation Microscopy
Multilayered protein coats are crucial to the dormancy, robustness, and germination of bacterial spores. In Bacillus subtilis spores, the coat contains over 70 distinct proteins. Identifying which proteins reside in each layer may provide insight into their distinct functions. We present image analysis methods that determine the order and geometry of concentric protein layers by fitting a model description for a spheroidal fluorescent shell image to optical micrographs of spores incorporating fluorescent fusion proteins. The radius of a spherical protein shell can be determined with <10 nm error by fitting an equation to widefield fluorescence micrographs. Ellipsoidal shell axes can be fitted with comparable precision. The layer orders inferred for B. subtilis and B. megaterium are consistent with measurements in the literature. The aspect ratio of elongated spores and the tendency of some proteins to localize near their poles can be quantified, enabling measurement of structural anisotropy.We gratefully acknowledge support from MedImmune through the Beacon collaboration, the EPSRC Centre for Doctoral Training in Sensor Technologies and Applications (EP/L015889/1), and thank Clemens Kaminski, Romain Laine and Jose Casas-Finet for inspiring discussions.This is the final version of the article. It first appeared from Elsevier via http://dx.doi.org/10.1016/j.bpj.2015.09.02
Robust Design Optimization of Electrical Machines and Devices
The article introduces a Special Issue (SI) of the journal Electronica that contains fourteen chosen articles from robust design optimization of electrical machines and devices. Optimization is essential for the research and design of electro-mechanical devices, especially electrical machines. Finding the optimal solutions may lead to cheaper, more economical products, faster and more efficient production, or more sustainable solutions. However, optimizing such a complex system as an electrical machine is a computationally expensive optimization problem, where many physical domains should be considered together. Practical design needs to consider the electrical device’s design parameters; it should be insensitive to parameter changes or manufacturing tolerances. This Special Issue focused on papers showing how modern artificial intelligence (AI) tools can be used for robust design optimization of electric machines and electrical devices, how these tools can be tested, or the correctness of the result validated
Immune Recognition of the 60kD Heat Shock Protein: Implications for Subsequent Fertility
The 60kD heat shock protein (hsp60) is a highly conserved protein and a dominant antigen of
most pathogenic bacteria. In some women, chronic or repeated upper genital tract infections with
Chlamydia trachomatis, and possibly with other microorganisms, induces immune sensitization to
epitopes of hsp60 that are present in both the microbial and human hsp60. Once a woman becomes
sensitized to these conserved epitpes, any subsequent induction of human or bacterial hsp60
expression will reactivate hsp60-sensitized lymphocytes and initiate a pro-inflammatory immune
response. Hsp60 is expressed during the early stages of pregnancy, by both the embryo and the
maternal decidua. We examined, therefore, whether women who were sensitized to hsp60 experienced
less successful pregnancy outcomes compared to women who were not sensitized to this
antigen. In women undergoing in vitro fertilization (IVF), the presence of cervical IgA antibodies
reactive with the C. trachomatis hsp60 correlated with implantation failure after embryo transfer.
Further analysis revealed that an immunodominant epitope for these IgA antibodies was an hsp60
epitope shared between C. trachomatis and man. In subsequent studies of women not undergoing
IVF, cervical IgA antibodies to the human hsp60 were identified in 13 of 91 reproductive age
women. This antibody was most prevalent in those women with a history of primary infertility
(p = 0.003). In addition, cervical anti-hsp60 IgA correlated with the detection of the pro-inflammatory
cytokines interferon-γ (p = 0.001) and tumor necrosis factor-α (p = 0.02) in the cervix.
Conversely, women with proven fertility had the highest prevalence of the anti-inflammatory cytokine,
interleukin 10, in their cervices (p = 0.001). In an analysis of serum samples in a third study,
women with a history of two or more consecutive first trimester spontaneous abortions had a higher
prevalence (p = 0.01) of IgG antibodies to the human hsp60 (36.8%) than did age matched fertile
women (11.1%) or women with primary infertility (11.8%). Immune sensitization to epitopes expressed
by the human hsp60 may reduce the probability of a successful pregnancy outcome due to
reactivation of hsp60-reactive lymphocytes, induction of a pro-inflammatory cytokine response and
interference with early embryo development and/or implantation
Transverse Expansion and High Azimuthal Asymmetry at RHIC
Rapid 3+1D transverse plus Bjorken collective expansion in collisions
at ultra-relativistic energies is shown to reduce substantially the azimuthal
asymmetry resulting from jet quenching. While the azimuthal asymmetry in
non-central collisions, reported by STAR at
RHIC, can be accounted for by spatially anisotropic jet energy loss through a
1+1D expanding gluon plasma with , we show that if rapid
transverse collective expansion of the plasma is assumed, then the asymmetry
due to jet quenching may be reduced below the observed level. Possible
implications of this effect are discussed.Comment: Journal version: 1 figure added, references added. 6 pages, 4 figure
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