Image Registration and Predictive Modeling: Learning the Metric on the Space of Diffeomorphisms

We present a method for metric optimization in the Large Deformation Diffeomorphic Metric Mapping (LDDMM) framework, by treating the induced Riemannian metric on the space of diffeomorphisms as a kernel in a machine learning context. For simplicity, we choose the kernel Fischer Linear Discriminant Analysis (KLDA) as the framework. Optimizing the kernel parameters in an Expectation-Maximization framework, we define model fidelity via the hinge loss of the decision function. The resulting algorithm optimizes the parameters of the LDDMM norm-inducing differential operator as a solution to a group-wise registration and classification problem. In practice, this may lead to a biology-aware registration, focusing its attention on the predictive task at hand such as identifying the effects of disease. We first tested our algorithm on a synthetic dataset, showing that our parameter selection improves registration quality and classification accuracy. We then tested the algorithm on 3D subcortical shapes from the Schizophrenia cohort Schizconnect. Our Schizophrenia-Control predictive model showed significant improvement in ROC AUC compared to baseline parameters

Familial deletion 18p syndrome: case report

BACKGROUND: Deletion 18p is a frequent deletion syndrome characterized by dysmorphic features, growth deficiencies, and mental retardation with a poorer verbal performance. Until now, five families have been described with limited clinical description. We report transmission of deletion 18p from a mother to her two daughters and review the previous cases. CASE PRESENTATION: The proband is 12 years old and has short stature, dysmorphic features and moderate mental retardation. Her sister is 9 years old and also has short stature and similar dysmorphic features. Her cognitive performance is within the borderline to mild mental retardation range. The mother also presents short stature. Psychological evaluation showed moderate mental retardation. Chromosome analysis from the sisters and their mother revealed the same chromosomal deletion: 46, XX, del(18)(p11.2). Previous familial cases were consistent regarding the transmission of mental retardation. Our family differs in this regard with variable cognitive impairment and does not display poorer verbal than non-verbal abilities. An exclusive maternal transmission is observed throughout those families. Women with del(18p) are fertile and seem to have a normal miscarriage rate. CONCLUSION: Genetic counseling for these patients should take into account a greater range of cognitive outcome than previously reported

Budding yeast ATM/ATR control meiotic double-strand break (DSB) levels by down-regulating Rec114, an essential component of the DSB-machinery

An essential feature of meiosis is Spo11 catalysis of programmed DNA double strand breaks (DSBs). Evidence suggests that the number of DSBs generated per meiosis is genetically determined and that this ability to maintain a pre-determined DSB level, or "DSB homeostasis", might be a property of the meiotic program. Here, we present direct evidence that Rec114, an evolutionarily conserved essential component of the meiotic DSB-machinery, interacts with DSB hotspot DNA, and that Tel1 and Mec1, the budding yeast ATM and ATR, respectively, down-regulate Rec114 upon meiotic DSB formation through phosphorylation. Mimicking constitutive phosphorylation reduces the interaction between Rec114 and DSB hotspot DNA, resulting in a reduction and/or delay in DSB formation. Conversely, a non-phosphorylatable rec114 allele confers a genome-wide increase in both DSB levels and in the interaction between Rec114 and the DSB hotspot DNA. These observations strongly suggest that Tel1 and/or Mec1 phosphorylation of Rec114 following Spo11 catalysis down-regulates DSB formation by limiting the interaction between Rec114 and DSB hotspots. We also present evidence that Ndt80, a meiosis specific transcription factor, contributes to Rec114 degradation, consistent with its requirement for complete cessation of DSB formation. Loss of Rec114 foci from chromatin is associated with homolog synapsis but independent of Ndt80 or Tel1/Mec1 phosphorylation. Taken together, we present evidence for three independent ways of regulating Rec114 activity, which likely contribute to meiotic DSBs-homeostasis in maintaining genetically determined levels of breaks

Follow My Eyes: The Gaze of Politicians Reflexively Captures the Gaze of Ingroup Voters

Studies in human and non-human primates indicate that basic socio-cognitive operations are inherently linked to the power of gaze in capturing reflexively the attention of an observer. Although monkey studies indicate that the automatic tendency to follow the gaze of a conspecific is modulated by the leader-follower social status, evidence for such effects in humans is meager. Here, we used a gaze following paradigm where the directional gaze of right- or left-wing Italian political characters could influence the oculomotor behavior of ingroup or outgroup voters. We show that the gaze of Berlusconi, the right-wing leader currently dominating the Italian political landscape, potentiates and inhibits gaze following behavior in ingroup and outgroup voters, respectively. Importantly, the higher the perceived similarity in personality traits between voters and Berlusconi, the stronger the gaze interference effect. Thus, higher-order social variables such as political leadership and affiliation prepotently affect reflexive shifts of attention

Construction et classification de certaines solutions algébriques des systèmes de Garnier

22 pagesInternational audienceIn this paper, we classify all (complete) non elementary algebraic solutions of Garnier systems that can be constructed by Kitaev's method: they are deduced from isomonodromic deformations defined by pulling back a given fuchsian equation E by a family of ramified covers. We first introduce orbifold structures associated to a fuchsian equation. This allow to get a refined version of Riemann-Hurwitz formula and then to promtly deduce that E is hypergeometric. Then, we can bound exponents and degree of the pull-back maps and further list all possible ramification cases. This generalizes a result due to C. Doran for the Painleve VI case. We explicitely construct one of these solutions

The NEI/NCBI dbGAP database: Genotypes and haplotypes that may specifically predispose to risk of neovascular age-related macular degeneration

<p>Abstract</p> <p>Background</p> <p>To examine if the significantly associated SNPs derived from the genome wide allelic association study on the AREDS cohort at the NEI (dbGAP) specifically confer risk for neovascular age-related macular degeneration (AMD). We ascertained 134 unrelated patients with AMD who had one sibling with an AREDS classification 1 or less and was past the age at which the affected sibling was diagnosed (268 subjects). Genotyping was performed by both direct sequencing and Sequenom iPLEX system technology. Single SNP analyses were conducted with McNemar's Test (both 2 × 2 and 3 × 3 tests) and likelihood ratio tests (LRT). Conditional logistic regression was used to determine significant gene-gene interactions. LRT was used to determine the best fit for each genotypic model tested (additive, dominant or recessive).</p> <p>Results</p> <p>Before release of individual data, <it>p</it>-value information was obtained directly from the AREDS dbGAP website. Of the 35 variants with <it>P </it>< 10^-6examined, 23 significantly modified risk of neovascular AMD. Many variants located in tandem on 1q32-q22 including those in <it>CFH</it>, <it>CFHR4</it>, <it>CFHR2</it>, <it>CFHR5</it>, <it>F13B</it>, <it>ASPM </it>and <it>ZBTB </it>were significantly associated with AMD risk. Of these variants, single SNP analysis revealed that <it>CFH </it>rs572515 was the most significantly associated with AMD risk (P < 10^-6). Haplotype analysis supported our findings of single SNP association, demonstrating that the most significant haplotype, GATAGTTCTC, spanning <it>CFH</it>, <it>CFHR4</it>, and <it>CFHR2 </it>was associated with the greatest risk of developing neovascular AMD (<it>P </it>< 10^-6). Other than variants on 1q32-q22, only two SNPs, rs9288410 (<it>MAP2</it>) on 2q34-q35 and rs2014307 (<it>PLEKHA1</it>/<it>HTRA1</it>) on 10q26 were significantly associated with AMD status (<it>P </it>= .03 and <it>P </it>< 10^-6respectively). After controlling for smoking history, gender and age, the most significant gene-gene interaction appears to be between rs10801575 (<it>CFH</it>) and rs2014307 (<it>PLEKHA1</it>/<it>HTRA1</it>) (<it>P </it>< 10^-11). The best genotypic fit for rs10801575 and rs2014307 was an additive model based on LRT. After applying a Bonferonni correction, no other significant interactions were identified between any other SNPs.</p> <p>Conclusion</p> <p>This is the first replication study on the NEI dbGAP SNPs, demonstrating that alleles on 1q, 2q and 10q may predispose an individual to AMD.</p

Observation of an Exotic S=+1S=+1 Baryon in Exclusive Photoproduction from the Deuteron

In an exclusive measurement of the reaction $\gamma d \to K^+ K^- p n$, a narrow peak that can be attributed to an exotic baryon with strangeness $S=+1$ is seen in the $K^+n$ invariant mass spectrum. The peak is at $1.542\pm 0.005$ GeV/c$^2$ with a measured width of 0.021 GeV/c$^2$ FWHM, which is largely determined by experimental mass resolution. The statistical significance of the peak is $5.2 \pm 0.6 \sigma$. The mass and width of the observed peak are consistent with recent reports of a narrow $S=+1$ baryon by other experimental groups.Comment: 5 pages, 5 figure

Measurement of Beam-Spin Asymmetries for Deep Inelastic π+\pi^+ Electroproduction

We report the first evidence for a non-zero beam-spin azimuthal asymmetry in the electroproduction of positive pions in the deep-inelastic region. Data have been obtained using a polarized electron beam of 4.3 GeV with the CLAS detector at the Thomas Jefferson National Accelerator Facility (JLab). The amplitude of the $\sin\phi$ modulation increases with the momentum of the pion relative to the virtual photon, $z$, with an average amplitude of $0.038 \pm 0.005 \pm 0.003$ for $0.5 < z < 0.8$ range.Comment: 5 pages, RevTEX4, 3 figures, 2 table

Measurement of the Polarized Structure Function σLT′\sigma_{LT^\prime} for p(e⃗,e′p)πop(\vec{e},e'p)\pi^o in the Δ(1232)\Delta(1232) Resonance Region

The polarized longitudinal-transverse structure function $\sigma_{LT^\prime}$ has been measured in the $\Delta(1232)$ resonance region at $Q^2=0.40$ and 0.65 GeV$^2$. Data for the $p(\vec e,e'p)\pi^o$ reaction were taken at Jefferson Lab with the CEBAF Large Acceptance Spectrometer (CLAS) using longitudinally polarized electrons at an energy of 1.515 GeV. For the first time a complete angular distribution was measured, permitting the separation of different non-resonant amplitudes using a partial wave analysis. Comparison with previous beam asymmetry measurements at MAMI indicate a deviation from the predicted $Q^2$ dependence of $\sigma_{LT^{\prime}}$ using recent phenomenological models.Comment: 5 pages, LaTex, 4 eps figures: to be published in PRC/Rapid Communications. Version 2 has revised Q^2 analysi

Two-Nucleon Momentum Distributions Measured in 3He(e,e'pp)n

We have measured the 3He(e,e'pp)n reaction at 2.2 GeV over a wide kinematic range. The kinetic energy distribution for `fast' nucleons (p > 250 MeV/c) peaks where two nucleons each have 20% or less, and the third nucleon has most of the transferred energy. These fast pp and pn pairs are back-to-back with little momentum along the three-momentum transfer, indicating that they are spectators. Experimental and theoretical evidence indicates that we have measured distorted two-nucleon momentum distributions by striking the third nucleon and detecting the spectator correlated pair.Comment: 6 pages, 5 figures, submitted to PR