527 research outputs found
The Effect of Divorce Laws on Divorce Rates in Europe
This paper analyzes a panel of 18 European countries spanning from 1950 to 2003 to examine the extent to which the legal reforms leading to "easier divorce" that took place during the second half of the 20th century have contributed to the increase in divorce rates across Europe. We use a quasi-experimental set-up and exploit the different timing of the reforms in divorce laws across countries. We account for unobserved country-specific factors by introducing country fixed effects, and we include country-specific trends to control for time-varying factors at the country level that may be correlated with divorce rates and divorce laws, such as changing social norms or slow moving demographic trends. We find that the different reforms that "made divorce easier" were followed by significant increases in divorce rates. The effect of no-fault legislation was strong and permanent, while unilateral reforms only had a temporary effect on divorce rates. Overall, we estimate that the legal reforms account for about 20 percent of the increase in divorce rates in Europe between 1960 and 2002
Electromagnetic wave refraction at an interface of a double wire medium
Plane-wave reflection and refraction at an interface with a double wire
medium is considered. The problem of additional boundary conditions (ABC) in
application to wire media is discussed and an ABC-free approach, known in the
solid state physics, is used. Expressions for the fields and Poynting vectors
of the refracted waves are derived. Directions and values of the power density
flow of the refracted waves are found and the conservation of the power flow
through the interface is checked. The difference between the results, given by
the conventional model of wire media and the model, properly taking into
account spatial dispersion, is discussed.Comment: 17 pages, 11 figure
Metabolic Engineering of the Chloroplast Genome Using the Echerichia coli ubiC Gene Reveals That Chorismate Is a Readily Abundant Plant Precursor for p-Hydroxybenzoic Acid Biosynthesis1
p-Hydroxybenzoic acid (pHBA) is the major monomer in liquid crystal polymers. In this study, the Escherichia coli ubiC gene that codes for chorismate pyruvate-lyase (CPL) was integrated into the tobacco (Nicotiana tabacum) chloroplast genome under the control of the light-regulated psbA 5′ untranslated region. CPL catalyzes the direct conversion of chorismate, an important branch point intermediate in the shikimate pathway that is exclusively synthesized in plastids, to pHBA and pyruvate. The leaf content of pHBA glucose conjugates in fully mature T1 plants exposed to continuous light (total pooled material) varied between 13% and 18% dry weight, while the oldest leaves had levels as high as 26.5% dry weight. The latter value is 50-fold higher than the best value reported for nuclear-transformed tobacco plants expressing a chloroplast-targeted version of CPL. Despite the massive diversion of chorismate to pHBA, the plastid-transformed plants and control plants were indistinguishable. The highest CPL enzyme activity in pooled leaf material from adult T1 plants was 50,783 pkat/mg of protein, which is equivalent to approximately 35% of the total soluble protein and approximately 250 times higher than the highest reported value for nuclear transformation. These experiments demonstrate that the current limitation for pHBA production in nuclear-transformed plants is CPL enzyme activity, and that the process becomes substrate-limited only when the enzyme is present at very high levels in the compartment of interest, such as the case with plastid transformation. Integration of CPL into the chloroplast genome provides a dramatic demonstration of the high-flux potential of the shikimate pathway for chorismate biosynthesis, and could prove to be a cost-effective route to pHBA. Moreover, exploiting this strategy to create an artificial metabolic sink for chorismate could provide new insight on regulation of the plant shikimate pathway and its complex interactions with downstream branches of secondary metabolism, which is currently poorly understood
Euclid: Fast two-point correlation function covariance through linear construction
We present a method for fast evaluation of the covariance matrix for a two-point galaxy correlation function (2PCF) measured with the Landy-Szalay estimator. The standard way of evaluating the covariance matrix consists in running the estimator on a large number of mock catalogs, and evaluating their sample covariance. With large random catalog sizes (random-to-data objects' ratio M >> 1) the computational cost of the standard method is dominated by that of counting the data-random and random-random pairs, while the uncertainty of the estimate is dominated by that of data-data pairs. We present a method called Linear Construction (LC), where the covariance is estimated for small random catalogs with a size of M = 1 and M = 2, and the covariance for arbitrary M is constructed as a linear combination of the two. We show that the LC covariance estimate is unbiased. We validated the method with PINOCCHIO simulations in the range r = 20-200 h(-1) Mpc. With M = 50 and with 2h(-1) Mpc bins, the theoretical speedup of the method is a factor of 14. We discuss the impact on the precision matrix and parameter estimation, and present a formula for the covariance of covariance.Peer reviewe
An integrated hardware/software design methodology for signal processing systems
This paper presents a new methodology for design and implementation of signal processing systems on system-on-chip (SoC) platforms. The methodology is centered on the use of lightweight application programming interfaces for applying principles of dataflow design at different layers of abstraction. The development processes integrated in our approach are software implementation, hardware implementation, hardware-software co-design, and optimized application mapping. The proposed methodology facilitates development and integration of signal processing hardware and software modules that involve heterogeneous programming languages and platforms. As a demonstration of the proposed design framework, we present a dataflow-based deep neural network (DNN) implementation for vehicle classification that is streamlined for real-time operation on embedded SoC devices. Using the proposed methodology, we apply and integrate a variety of dataflow graph optimizations that are important for efficient mapping of the DNN system into a resource constrained implementation that involves cooperating multicore CPUs and field-programmable gate array subsystems. Through experiments, we demonstrate the flexibility and effectiveness with which different design transformations can be applied and integrated across multiple scales of the targeted computing system
Coupling and Guided Propagation along Parallel Chains of Plasmonic Nanoparticles
Here, extending our previous work on this topic, we derive a dynamic
closed-form dispersion relation for a rigorous analysis of guided wave
propagation along coupled parallel linear arrays of plasmonic nanoparticles,
operating as optical 'two-line' waveguides. Compared to linear arrays of
nanoparticles, our results suggest that these waveguides may support longer
propagation lengths and more confined beams, operating analogously to
transmission-line segments at lower frequencies. Our formulation fully takes
into account the whole dynamic interaction among the infinite number of
nanoparticles composing the parallel arrays, considering also realistic
presence of losses and the frequency dispersion of the involved plasmonic
materials, providing further physical insights into the guidance properties
that characterize this geometry.Comment: 34 pages, 11 figure
Insuliiniresistenssi, aivot ja muistisairausriski
Tyypin 2 diabetes ja siihen liittyvä insuliiniresistenssi ovat muistisairauden riskitekijöitä. Insuliiniresistenssi ennustaa tiedonkäsittelytoimintojen heikentymistä jo henkilöillä, joille ei vielä ole kehittynyt diabetesta. Insuliinilla on useita tärkeitä säätelytehtäviä keskushermostossa. Se vaikuttaa esimerkiksi synapsien toimintaan ja niiden pitkäkestoiseen vahvistumiseen. Insuliiniresistenssiin liittyvään hyperinsulinemiaan on puolestaan yhdistetty paradoksaalisesti keskushermoston pienentynyt insuliinipitoisuus. Alzheimerin tautia sairastavilla insuliinin vaste keskushermostossa on heikentynyt. Insuliinilla ja Alzheimerin taudille tyypillisellä beeta-amyloidilla on aivoissa yhteinen hajottajaentsyymi. Muutokset tämän entsyymin toiminnassa ja määrässä voivat vaikuttaa beeta-amyloidin kertymään aivoissa. Insuliiniresistenssi voi altistaa kognition heikentymiselle myös aivojen pienten suonten muutosten kautta. Insuliiniresistenssi voi siis vaikuttaa tiedonkäsittelytoimintoihin ja Alzheimerin taudin neuropatologiaan useita eri reittejä.</p
Primary familial brain calcification linked to deletion of 5' noncoding region of SLC20A2
OBJECTIVES: Primary familial brain calcification (PFBC) is a rare neurological disease often inherited as a dominant trait. Mutations in four genes (SLC20A2, PDGFB, PDGFRB, and XPR1) have been reported in patients with PFBC. Of these, point mutations or small deletions in SLC20A2 are most common. Thus far, only one large deletion covering entire SLC20A2 and several smaller, exonic deletions of SLC20A2 have been reported. The aim of this study was to identify the causative gene defect in a Finnish PFBC family with three affected patients. MATERIALS AND METHODS: A Finnish family with three PFBC patients and five unaffected subjects was studied. Sanger sequencing was used to exclude mutations in the coding and splice site regions of SLC20A2, PDGFRB, and PDGFB. Whole-exome (WES) and whole-genome sequencing (WGS) were performed to identify the causative mutation. A SNP array was used in segregation analysis. RESULTS: Copy number analysis of the WGS data revealed a heterozygous deletion of ~578 kb on chromosome 8. The deletion removes the 5' UTR region, the noncoding exon 1 and the putative promoter region of SLC20A2 as well as the coding regions of six other genes. CONCLUSIONS: Our results support haploinsufficiency of SLC20A2 as a pathogenetic mechanism in PFBC. Analysis of copy number variations (CNVs) is emerging as a crucial step in the molecular genetic diagnostics of PFBC, and it should not be limited to coding regions, as causative variants may reside in the noncoding parts of known disease-associated genes
Collective plasmonic modes of metal nano-particles in two-dimensional periodic regular arrays
We investigate the collective plasmonic modes of metal nano-particles in
periodic two-dimensional (2D) arrays within a point-dipole description. As an
open system, the full-dynamic dispersion relations of the 2D arrays are
obtained through an efficient method which gives an effective polarizability
describing the collective response of a system. Both the dispersion relations
and mode qualities are simultaneously related to the imaginary part of the
effective polarizability, which has contributions from the single-particle
response as well as the inter-particle coupling. The transversal long-range
dipolar interaction is dominated by a wave term together with a purely
geometrical constant representing the static geometrical contribution to
resonant frequencies. As concrete examples, we considered small Ag spheres
arranged in a square lattice. We find that inside the light-cone, the
transverse quasi-mode has a reasonably high mode quality while the two in-plane
modes show significant radiation damping. Near the light-line, we observe
strong coupling with free photons for the bands of the transverse mode and the
transversal in-plane mode, and the longitudinal in-plane mode exhibits a
negative group-velocity inside the light-cone. Vanishing group velocities in
the light-cone for all the quasi-modes are found to be intrinsic properties of
the 2D metal nano-sphere dense arrays.Comment: 26 pages, 8 figure
Clusterin/Apolipoprotein J immunoreactivity is associated with white matter damage in cerebral small vessel diseases
Aim: Brain clusterin is known to be associated with the amyloid‐β deposits in Alzheimer's disease (AD). We assessed the distribution of clusterin immunoreactivity in cerebrovascular disorders, particularly focusing on white matter changes in small vessel diseases. Methods: Post‐mortem brain tissues from the frontal or temporal lobes of a total of 70 subjects with various disorders including cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), cerebral amyloid angiopathy (CAA) and AD were examined using immunohistochemistry and immunofluorescence. We further used immunogold electron microscopy to study clusterin immunoreactivity in extracellular deposits in CADASIL. Results: Immunostaining with clusterin antibodies revealed strong localization in arterioles and capillaries, besides cortical neurones. We found that clusterin immunostaining was significantly increased in the frontal white matter of CADASIL and pontine autosomal dominant microangiopathy and leukoencephalopathy subjects. In addition, clusterin immunostaining correlated with white matter pathology severity scores. Immunostaining in axons ranged from fine punctate deposits in single axons to larger confluent areas with numerous swollen axon bulbs, similar to that observed with known axon damage markers such as non‐phosphorylated neurofilament H and the amyloid precursor protein. Immunofluorescence and immunogold electron microscopy experiments showed that whereas clusterin immunoreactivity was closely associated with vascular amyloid‐β in CAA, it was lacking within the granular osmiophilic material immunolabelled by NOTCH3 extracelluar domain aggregates found in CADASIL. Conclusions: Our results suggest a wider role for clusterin associated with white matter damage in addition to its ability to chaperone proteins for clearance via the perivascular drainage pathways in several disease states
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