283 research outputs found
Correlation between Penile Length and Anogenital Distance in Term Newborns, Gorgan, 2011
Background and purpose: Anogenital distance is an accepted indicator for endogenous or
environmental effects of androgens on development of reproductive system in fetus and newborns. This
study was done to determine the relationship between penile length and anogenital distance in Iranian
newborns.
Material and Methods: In this cross-sectional study stretched penile length (PL) and anogenital
distance (AGD) were measured in 427 healthy male newborn infants born in a Teaching Hospital (in
north of Iran). Other variables included the age of mothers, and weight, height, and head circumference of
neonates. Normal distribution of variables was measured by Shapiro-Wilk and data was analyzed using
Pearson Correlation tests
Results: The mean of PL was 32.1±3.5 mm and the mean of AGD was 24.5±2.5mm. A weak
correlation was observed between PL and AGD (r=0.097, p=0.046).
Conclusion: The correlation between penile length and AGD showed that, AGD could be also
used in assessing the genital system and even as a common indicator to assess the genital system in both
sexes
Keywords: penile length, anogenital, distance,term newborn, mal
Recovering quantum information through partial access to the environment
We investigate the possibility of correcting errors occurring on a
multipartite system through a feedback mechanism that acquires information from
partial access to the environment. A partial control scheme of this kind might
be useful when dealing with correlated errors. In fact, in such a case, it
could be enough to gather local information to decide what kind of global
recovery to perform. Then, we apply this scheme to the depolarizing and
correlated errors, and quantify its performance by means of the entanglement
fidelity
Forgetfulness of continuous Markovian quantum channels
The notion of forgetfulness, used in discrete quantum memory channels, is
slightly weakened in order to be applied to the case of continuous channels.
This is done in the context of quantum memory channels with Markovian noise. As
a case study, we apply the notion of weak-forgetfulness to a bosonic memory
channel with additive noise. A suitable encoding and decoding unitary
transformation allows us to unravel the effects of the memory, hence the
channel capacities can be computed using known results from the memoryless
setting.Comment: 6 pages, 2 figures, comments are welcome. Minor corrections and
acknoledgment adde
Equi-entangled bases in arbitrary dimensions
For the space of two identical systems of arbitrary dimensions, we introduce
a continuous family of bases with the following properties: i) the bases are
orthonormal, ii) in each basis, all the states have the same values of
entanglement, and iii) they continuously interpolate between the product basis
and the maximally entangled basis. The states thus constructed may find
applications in many areas related to quantum information science including
quantum cryptography, optimal Bell tests and investigation of enhancement of
channel capacity due to entanglement.Comment: 10 pages, 2 figures, 1 table, Accepted for publication in Phys. Rev.
Recommended from our members
Retraction Note: An apoptosis-enhancing drug overcomes platinum resistance in a tumour-initiating subpopulation of ovarian cancer.
This Article has been retracted; see accompanying Retraction Note
New Phase Transitions in Optimal States for Memory Channels
We investigate the question of optimal input ensembles for memory channels
and construct a rather large class of Pauli channels with correlated noise
which can be studied analytically with regard to the entanglement of their
optimal input ensembles. In a more detailed study of a subclass of these
channels, the complete phase diagram of the two-qubit channel, which shows
three distinct phases is obtained. While increasing the correlation generally
changes the optimal state from separable to maximally entangled states, this is
done via an intermediate region where both separable and maximally entangled
states are optimal. A more concrete model, based on random rotations of the
error operators which mimic the behavior of this subclass of channels is also
presented.Comment: 13 pages, Late
Characterization of qutrit channels in terms of their covariance and symmetry properties
We characterize the completely positive trace-preserving maps on qutrits
(qutrit channels) according to their covariance and symmetry properties. Both
discrete and continuous groups are considered. It is shown how each symmetry
group restricts arbitrariness in the parameters of the channel to a very small
set. Although the explicit examples are related to qutrit channels, the
formalism is sufficiently general to be applied to qudit channels
Transition behavior in the capacity of correlated-noisy channels in arbitrary dimensions
We construct a class of quantum channels in arbitrary dimensions for which
entanglement improves the performance of the channel. The channels have
correlated noise and when the level of correlation passes a critical value we
see a sharp transition in the optimal input states (states which minimize the
output entropy) from separable to maximally entangled states. We show that for
a subclass of channels with some extra conditions, including the examples which
we consider, the states which minimize the output entropy are the ones which
maximize the mutual information.Comment: 11 pages, Latex, 4 figures, Accepted for publication in Physical
Review
Quantum information reclaiming after amplitude damping
We investigate the quantum information reclaim from the environment after
amplitude damping has occurred. In particular we address the question of
optimal measurement on the environment to perform the best possible correction
on two and three dimensional quantum systems. Depending on the dimension we
show that the entanglement fidelity (the measure quantifying the correction
performance) is or is not the same for all possible measurements and uncover
the optimal measurement leading to the maximum entanglement fidelity
AI-aided exploration of lunar arch forms under in-plane seismic loading
Increasing computational power has led to the expansion of civil engi- neering research into using machine learning concepts for developing improved design strategies. These strategies are particularly useful for the design of extra-terrestrial habitats under uncertain environmental conditions. This paper focuses on building an unsupervised machine learning model (convolutional autoencoder) capable of detecting patterns in arch shapes and differentiating between their stress and displacement contours. Foremost, detailed discussions of the model’s architecture and input data are presented. The variation of arch shapes and con- tours between cluster centroids in the latent space is determined, proving the capability of optimisation by moving towards clusters with optimal contours. Finally, a regression model is built to investigate the rela- tionship between the input geometric variables and the latent space representation. We prove that the autoencoder and regression mod- els produce arch shapes with logical structural contours given a set of input geometric variables. The results presented in this paper provide essential tools for the development of an automated design strategy capable of finding optimal arch shapes for extra-terrestrial habitats
- …