1,382 research outputs found
Economic conditions and the health of newborns:Evidence from comprehensive register data
We examine whether economic downturns are beneficial to health outcomes of newborn infants in developed countries. For this we use merged population-wide registers on health and economic and demographic variables, including the national medical birth register and intergenerational link registers from Sweden covering 1992–2004. We take a rigorous econometric approach that exploits regional variation in unemployment and compares babies born to the same parents so as to deal with possible selective fertility based on labour market conditions. We find that downturns are beneficial; an increase in the unemployment rate during pregnancy reduces the probability of having a birth weight less than 1500 grams or of dying within 28 days of birth. Effects are larger in low socio-economic status households. Health improvements cannot be attributed to the parents’ own employment status. Instead, the results suggest other pathways triggered by the economic cycle
Concrete resource analysis of the quantum linear system algorithm used to compute the electromagnetic scattering cross section of a 2D target
We provide a detailed estimate for the logical resource requirements of the
quantum linear system algorithm (QLSA) [Phys. Rev. Lett. 103, 150502 (2009)]
including the recently described elaborations [Phys. Rev. Lett. 110, 250504
(2013)]. Our resource estimates are based on the standard quantum-circuit model
of quantum computation; they comprise circuit width, circuit depth, the number
of qubits and ancilla qubits employed, and the overall number of elementary
quantum gate operations as well as more specific gate counts for each
elementary fault-tolerant gate from the standard set {X, Y, Z, H, S, T, CNOT}.
To perform these estimates, we used an approach that combines manual analysis
with automated estimates generated via the Quipper quantum programming language
and compiler. Our estimates pertain to the example problem size N=332,020,680
beyond which, according to a crude big-O complexity comparison, QLSA is
expected to run faster than the best known classical linear-system solving
algorithm. For this problem size, a desired calculation accuracy 0.01 requires
an approximate circuit width 340 and circuit depth of order if oracle
costs are excluded, and a circuit width and depth of order and
, respectively, if oracle costs are included, indicating that the
commonly ignored oracle resources are considerable. In addition to providing
detailed logical resource estimates, it is also the purpose of this paper to
demonstrate explicitly how these impressively large numbers arise with an
actual circuit implementation of a quantum algorithm. While our estimates may
prove to be conservative as more efficient advanced quantum-computation
techniques are developed, they nevertheless provide a valid baseline for
research targeting a reduction of the resource requirements, implying that a
reduction by many orders of magnitude is necessary for the algorithm to become
practical.Comment: 37 pages, 40 figure
Learning control of hearing aid parameter settings
In a hearing aid with a signal processor for signal processing in accordance with selected values of a set of parameters Θ, a method of automatic adjustment of a set z of the signal processing parameters Θ, using a set of learning parameters θ of the signal processing parameters Θ is provided, wherein the method includes extracting signal features u of a signal in the hearing aid, recording a measure r of an adjustment e made by the user of the hearing aid, modifying z by the equation z=u θ+r, and absorbing the user adjustment e in θ by the equation θN=Φ(u,r)+θP, wherein θN is the new values of the learning parameter set θ, θP is the previous values of the learning parameter set θ, and Φ is a function of the signal features u and the recorded adjustment measure r
Single-molecule real-time sequencing combined with optical mapping yields completely finished fungal genome
Next-generation sequencing (NGS) technologies have increased the scalability, speed, and resolution of genomic sequencing and, thus, have revolutionized genomic studies. However, eukaryotic genome sequencing initiatives typically yield considerably fragmented genome assemblies. Here, we assessed various state-of-the-art sequencing and assembly strategies in order to produce a contiguous and complete eukaryotic genome assembly, focusing on the filamentous fungus Verticillium dahliae. Compared with Illumina-based assemblies of the V. dahliae genome, hybrid assemblies that also include PacBio- generated long reads establish superior contiguity. Intriguingly, provided that sufficient sequence depth is reached, assemblies solely based on PacBio reads outperform hybrid assemblies and even result in fully assembled chromosomes. Furthermore, the addition of optical map data allowed us to produce a gapless and complete V. dahliae genome assembly of the expected eight chromosomes from telomere to telomere. Consequently, we can now study genomic regions that were previously not assembled or poorly assembled, including regions that are populated by repetitive sequences, such as transposons, allowing us to fully appreciate an organism’s biological complexity. Our data show that a combination of PacBio-generated long reads and optical mapping can be used to generate complete and gapless assemblies of fungal genomes. IMPORTANCE Studying whole-genome sequences has become an important aspect of biological research. The advent of nextgeneration sequencing (NGS) technologies has nowadays brought genomic science within reach of most research laboratories, including those that study nonmodel organisms. However, most genome sequencing initiatives typically yield (highly) fragmented genome assemblies. Nevertheless, considerable relevant information related to genome structure and evolution is likely hidden in those nonassembled regions. Here, we investigated a diverse set of strategies to obtain gapless genome assemblies, using the genome of a typical ascomycete fungus as the template. Eventually, we were able to show that a combination of PacBiogenerated long reads and optical mapping yields a gapless telomere-to-telomere genome assembly, allowing in-depth genome sanalyses to facilitate functional studies into an organism’s biology
Living donor hand-assisted laparoscopic nephrectomy in a healthy individual with situs inversus totalis:no need to turn down the donor
A 70-year-old healthy male individual offered to undergo a living donor hand-assisted laparoscopic nephrectomy to enable kidney transplantation for a close relative. As required for all living transplant donor candidates, extensive screening was performed to exclude potential contraindications for donation. Tests revealed a situs inversus totalis, meaning a complete transposition of the thoracic and abdominal organs in the sagittal plane. As other contraindications for living kidney donation were absent, the feasibility of this procedure was determined multidisciplinary. A successful donation procedure was performed without surgical complications for the donor and good short-term transplant outcomes. In line with current developments that have resulted in more liberal criteria for potential living kidney donors, major anatomical deviations should not automatically be a contraindication. With multidisciplinary efforts and thorough surgical preparation at a high-volume transplant centre, this procedure is feasible and safe
Scaling Limits for Minimal and Random Spanning Trees in Two Dimensions
A general formulation is presented for continuum scaling limits of stochastic
spanning trees. A spanning tree is expressed in this limit through a consistent
collection of subtrees, which includes a tree for every finite set of endpoints
in . Tightness of the distribution, as , is established for
the following two-dimensional examples: the uniformly random spanning tree on
, the minimal spanning tree on (with random edge
lengths), and the Euclidean minimal spanning tree on a Poisson process of
points in with density . In each case, sample trees are
proven to have the following properties, with probability one with respect to
any of the limiting measures: i) there is a single route to infinity (as was
known for ), ii) the tree branches are given by curves which are
regular in the sense of H\"older continuity, iii) the branches are also rough,
in the sense that their Hausdorff dimension exceeds one, iv) there is a random
dense subset of , of dimension strictly between one and two, on the
complement of which (and only there) the spanning subtrees are unique with
continuous dependence on the endpoints, v) branching occurs at countably many
points in , and vi) the branching numbers are uniformly bounded. The
results include tightness for the loop erased random walk (LERW) in two
dimensions. The proofs proceed through the derivation of scale-invariant power
bounds on the probabilities of repeated crossings of annuli.Comment: Revised; 54 pages, 6 figures (LaTex
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Understanding disability glare: light scatter and retinal illuminance as predictors of sensitivity to contrast
The presence of a bright light in the visual field has two main effects on the retinal image: reduced contrast and increased retinal illuminance due to scattered light; the latter can, under some conditions, lead to an improvement in retinal sensitivity. The combined effect remains poorly understood, particularly at low light levels. A psychophysical flicker-cancellation test was used to measure the amount and angular distribution of scattered light in the eye for 40 observers. Contrast thresholds were measured using a functional contrast sensitivity test. Pupil-plane glare-source illuminances (i.e. 0, 1.35, 19.21 lm/m2), eccentricities (5°, 10°, 15°), and background luminances (1, 2.6, 26 cd/m2) were investigated. Visual performance was better than predicted, based on loss of retinal image contrast caused by scattered light, particularly in the mesopic range. Prediction accuracy improved significantly when the expected increase in retinal sensitivity in the presence of scattered light was also incorporated in the model
A Parametric Study of Radiative Dipole Body Array Coil for 7 Tesla MRI
In this contribution we present numerical and experimental results of a
parametric quantitative study of radiative dipole antennas in a phased array
configuration for efficient body magnetic resonance imaging at 7T via parallel
transmission. For magnetic resonance imaging (MRI) at ultrahigh fields (7T and
higher) dipole antennas are commonly used in phased arrays, particularly for
body imaging targets. This study reveals the effects of dipole positioning in
the array (elevation of dipoles above the subject and inter-dipole spacing) on
their mutual coupling, per and per maximum local
SAR efficiencies as well as the RF-shimming capability. The numerical and
experimental results are obtained and compared for a homogeneous phantom as
well as for a real human models confirmed by in-vivo experiments
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