Weighing Neutrinos with Galaxy Cluster Surveys

Large future galaxy cluster surveys, combined with cosmic microwave background observations, can achieve a high sensitivity to the masses of cosmologically important neutrinos. We show that a weak lensing selected sample of ~100,000 clusters could tighten the current upper bound on the sum of masses of neutrino species by an order of magnitude, to a level of 0.03 eV. Since this statistical sensitivity is below the best existing lower limit on the mass of at least one neutrino species, a future detection is likely, provided that systematic errors can be controlled to a similar level.Comment: 4 pages, 1 figure, version accepted for publication in PR

Repetition Probability Does Not Affect fMRI Repetition Suppression for Objects

Previously several functional magnetic resonance imaging (fMRI) studies point toward the role of perceptual expectations in determining adaptation or repetition suppression (RS) in humans. These studies showed that the probability of repetitions of faces within a block influences the magnitude of adaptation in face-related areas of the human brain (Summerfield et al., 2008). However, a current macaque single-cell/local field potential (LFP) recording study using objects as stimuli found no evidence for the modulation of the neural response by the repetition probability in the inferior temporal cortex (Kaliukhovich and Vogels, 2010). Here we examined whether stimulus repetition probability affects fMRI repetition suppression for nonface object stimuli in the human brain. Subjects were exposed to either two identical [repetition trials (RTs)] or two different [alternation trials (ATs)] object stimuli. Both types of trials were presented blocks consisting of either 75% [repetition blocks (RBs)] or 25% [alternation blocks (ABs)] of RTs. We found strong RS, i.e., a lower signal for RTs compared to ATs, in the object sensitive lateral occipital cortex as well as in the face-sensitive occipital and fusiform face areas. More importantly, however, there was no significant difference in the magnitude of RS between RBs and ABs in each of the areas. This is in agreement with the previous monkey single-unit/LFP findings and suggests that RS in the case of nonface visual objects is not modulated by the repetition probability in humans. Our results imply that perceptual expectation effects vary for different visual stimulus categories

An Evolving Entropy Floor in the Intracluster Gas?

Non-gravitational processes, such as feedback from galaxies and their active nuclei, are believed to have injected excess entropy into the intracluster gas, and therefore to have modified the density profiles in galaxy clusters during their formation. Here we study a simple model for this so-called preheating scenario, and ask (i) whether it can simultaneously explain both global X-ray scaling relations and number counts of galaxy clusters, and (ii) whether the amount of entropy required evolves with redshift. We adopt a baseline entropy profile that fits recent hydrodynamic simulations, modify the hydrostatic equilibrium condition for the gas by including approx. 20% non-thermal pressure support, and add an entropy floor K_0 that is allowed to vary with redshift. We find that the observed luminosity-temperature (L-T) relations of low-redshift (z=0.05) HIFLUGCS clusters and high-redshift (z=0.8) WARPS clusters are best simultaneously reproduced with an evolving entropy floor of K_0(z)=341(1+z)^{-0.83}h^{-1/3} keV cm^2. If we restrict our analysis to the subset of bright (kT > 3 keV) clusters, we find that the evolving entropy floor can mimic a self-similar evolution in the L-T scaling relation. This degeneracy with self-similar evolution is, however, broken when (0.5 < kT < 3 keV) clusters are also included. The approx. 60% entropy increase we find from z=0.8 to z=0.05 is roughly consistent with that expected if the heating is provided by the evolving global quasar population. Using the cosmological parameters from the WMAP 3-year data with sigma_8=0.76, our best-fit model underpredicts the number counts of the X-ray galaxy clusters compared to those derived from the 158 deg^2 ROSAT PSPC survey. Treating sigma_8 as a free parameter, we find a best-fit value of sigma_8=0.80+/- 0.02.Comment: 14 emulateapj pages with 9 figures, submitted to Ap

Novel frameshift mutation in the CHD7 gene associated with CHARGE syndrome with preaxial polydactyly

We report a male patient with multiple congenital anomalies, including coloboma, Fallot tetralogy, bilateral choanal atresia, dysmorphic features (low set malformed ears, fronto-maxillary facial angle deviation, hypertelorism, retrognathism), micropenis, preaxial polydactyly and ureter stenosis. The major abnormalities had been diagnosed in prenatal period by ultrasound examination and the clinical diagnosis of CHARGE syndrome was established in postnatal periode by sequence analysis of the CHD7 coding region pointing to a novel heterozygous 4-basepair deletion in exon 3 that leads to an early stop codon and truncated CHD7 protein. Based on previous literature reports this is the first case of CHARGE syndrome with preaxial polydactyly characterized by this frameshift mutation. This case report allows further delineation of CHARGE syndrome polymorphism

Függvényegyenletek és egyenlőtlenségek = Functional equations and inequalities

A kutatásban 19 fő vett részt. A kutatócsoport tagjai 2003 és 2006 között 3 könyvet, 103 referált nemzetközi folyóiratban, vagy konferenciakiadványban megjelent tudományos dolgozatot, további 15 közlésre elfogadott dolgozatot, 6 PhD, 1 habilitációs és 2 MTA doktori értekezést készítettek, továbbá 208 tudományos előadást tartottak. A nem-iteratív függvényegyenletek regularitáselméletének monografikus összefoglalását adja Járai Antal 2005-ben a Kluwer kiadónál megjelent könyve. Ez mű az elmúlt két évtizedben a kutatócsoport által elért eredményeket egységes szemléletmódban tárgyalja és új alkalmazásokat is bemutat. Az iteratív függvényegyenletek és az un. invariancia-egyenlet regularitási vizsgálataiban is számos új módszer és eredmény született. A spektrálszintézis és spektrálanalízis kutatásában döntő áttörést hoztak Székelyhidi László kutatásai. Kiderült, hogy bizonyos diszkrét Abel-csoportokon a spektrálszintézis nem teljesülhet, ezzel egy több évtizede fennálló sejtés is megdőlt. A témakör elméletének alapvető és lezáró eredményeit tartalmazó monográfia 2006-ban a Springer kiadónál jelent meg. A lineáris operátorok és függvényterek megőrzési problémáinak összefoglalását adja Molnár Lajosnak a Springer Lecture Notes sorozatában 2007-ben megjelent könyve. A Hadamard-egyenlőtlenség magasabbrendű általánosításainak és a közelítőleg konvex függvényeknek a vizsgálata is számos új fejleményet hozott. | The research was carried out by 19 researchers. The members of the research team published 3 books, 103 research papers in refereed journals or conference proceedings, 15 papers accepted for publication, furthermore, 6 PhD, 1 habilitation and 2 DSc dissertations in the period 2003-2006. The monographic summary of the regularity theory of non-iterative functional equations was published by Antal Járai at the Kluwer Academic Publishers. This work treats the results of the research team obtained in the last two decades in a unified manner and also presents new applications. The investigation of the regularity problems of the iterative functional equations and the so-called invariance equation lead to a number of new methods and results. The investigation of spectral synthesis and spectral analysis reached a breakthrough point due to László Székelyhidi's results. It turned out that the spectral synthesi fails to hold on certain discrete Abelian groups. This result negatively answered a longstanding conjecture. The basic and key results of the subject were summarized in a book published by Springer Verlag. A book by Lajos Molnár, published in the Lecture Notes of Springer in 2007, summarizes the results obtained on preserver problems of linear operators and functions spaces. There were also new and interesting developments in the investigation of higher-order generalizations of the Hadamard inequality and approximately convex functions

Phenotype–Genotype Correlations in Three Different Cases of Adult-Onset Genetic Focal Segmental Glomerulosclerosis

This study highlights the importance of a combined diagnostic approach in the diagnosis of rare diseases, such as adult-onset genetic FSGS. We present three adult patient cases evaluated with kidney biopsy for proteinuria, chronic kidney disease, and hypertension, which were suggestive of adult-onset genetic FSGS. Renal biopsy samples and formalin-fixed, paraffin-embedded fetal kidneys were evaluated using standard light microscopical stainings, direct immunofluorescence on cryostat sections, and electron microscopy. Clinical exome sequencing was performed for each case, and 45 FSGS-related genes were analyzed. Identifying mutations in the PAX2, ACTN4, and COL4A5 genes have prompted a re-evaluation of the previous histopathological examinations. The PAX2 mutation led to a thinner nephrogenic zone and decreased number of glomeruli, resulting in oligohydramnios during fetal development and oligomeganephronia and adaptive focal-segmental glomerulosclerosis in adulthood. The ACTN4 mutation caused distinct electron-dense aggregates in podocyte cell bodies, while the COL4A5 mutation led to segmental sclerosis of glomeruli with marked interstitial fibrosis and tubular atrophy. The identification of specific mutations and their histopathological consequences can lead to a better understanding of the disease and its progression, as well as potential treatment options

Függvényegyenletek és egyenlőtlenségek = Functional equations and inequalities

A kutatás fő vizsgálatai függvényegyenletek és függvényegyenlőtlenségek általános elméleti kérdéseire, illetve ezek különféle matematikai, információelméleti, valószínűségszámítási, közgazdasági alkalmazásaira irányultak. Ezen belül foglalkoztunk összetett függvényeket tartalmazó függvényegyenletekkel, függvényegyenletek regularitáselméletével, függvényegyenletekre és függvényegyenlőtlenségekre vonatkozó stabilitási problémákkal, középértékekre vonatkozó összehasonlítási, egyenlőségi és homogenitási problémákkal és invariancia egyenletekkel, a konvexitás magasabb-rendű és különféle általánosításaival, a konvexitási tulajdonságok stabilitásával, valószínűségeloszlások függvényegyenletes jellemzésével, az informácimértékek jellemzésével és stabilitásával, a spektrálszintézis és spektrálanalízis csoporton és hipercsoportokon való teljesülésének szükséges és elegendő feltételeinek teljesülésével, az alavető függvényegyenletek hipercsoportokon való megoldásával, valamint operátoralgebrák, függvényalgebrák és kvantumstruktúrák megőrzési problémáinak vizsgálatával. A kutatás eredményeként 118 publikáció született, amelyből 1 monográfia, 1 szerkesztett könyv, 3 PhD értekezés, 98 referált nemzetközi folyóiratcikk, 15 pedig referált konferenciakiadványban jelent meg, és több mint 100 konferencia előadást tartottunk. | The main directions of our research were to investigate general problems of the theory of functional equations and functional inequalities, and to apply these results to various questions of other branches of mathematics, information theory, probability theory, and economics. More specifically, we dealt with functional equations involving iterates of unknown functions, with regularity theory of functional equations, with stability problems of functional equations and inequalities, with comparison, equality, and homogeneity problems and invariance equation in various classes of means, with higher-order and other types of generalizations of convexity, with stability of convexity properties, with characterization and stability of information measures, with characterizations of probability distributions, with spectral synthesis and spectral analysis on groups and hypergroups, with solution of the basic functional equations on hypergroups, with preserver problems of operator and function algebras and quantum structures. The results were published in 1 monograph. in 1 edited book, in 3 PhD dissertations, in 98 referred journal articles and in 15 referred conference proceedings article

Constraining the Evolution of Dark Energy with a Combination of Galaxy Cluster Observables

We show that the abundance and redshift distribution ($dN/dz$) of galaxy clusters in future high--yield cluster surveys, combined with the spatial power spectrum ($P_c(k)$) of the same clusters, can place significant constraints on the evolution of the dark energy equation of state, $w=w(a)$. We evaluate the expected errors on $w_a=-dw/da$ and other cosmological parameters using a Fisher matrix approach, and simultaneously including cluster structure evolution parameters in our analysis. We study three different types of forthcoming surveys that will identify clusters based on their X-ray emission (such as DUO, the Dark Universe Observatory), their Sunyaev--Zel'dovich (SZ) decrement (such as SPT, the South Pole Telescope), or their weak lensing (WL) shear (such as LSST, the Large Synoptic Survey Telescope). We find that combining the cluster abundance and power spectrum significantly enhances constraints from either method alone. We show that the weak-lensing survey can deliver a constraint as tight as $\Delta w_a \sim 0.1$ on the evolution of the dark energy equation of state, and that the X-ray and SZ surveys each yield $\Delta w_a \sim 0.4$ separately, or $\Delta w_a \sim 0.2$ when these two surveys are combined. For the X-ray and SZ surveys, constraints on dark energy parameters are improved by a factor of two by combining the cluster data with cosmic microwave background (CMB) anisotropy measurements by Planck, but degrade by a factor of two if the survey is required to solve simultaneously for cosmological and cluster structure evolution parameters. The constraint on $w_a$ from the weak lensing survey is improved by $\sim 25$% with the addition of Planck data.Comment: 13 pages. v2: Expanded discussion of weak lensing survey (LSST), improved CMB analysis, references added, final version published in PR

Constraining Cosmology with High Convergence Regions in Weak Lensing Surveys

We propose to use a simple observable, the fractional area of "hot spots" in weak gravitational lensing mass maps which are detected with high significance, to determine background cosmological parameters. Because these high-convergence regions are directly related to the physical nonlinear structures of the universe, they derive cosmological information mainly from the nonlinear regime of density fluctuations. We show that in combination with future cosmic microwave background anisotropy measurements, this method can place constraints on cosmological parameters that are comparable to those from the redshift distribution of galaxy cluster abundances. The main advantage of the statistic proposed in this paper is that projection effects, normally the main source of uncertainty when determining the presence and the mass of a galaxy cluster, here serve as a source of information.Comment: 14 pages, 4 figures, accepted for publication in Astrophysical Journa

Neocortical Axon Arbors Trade-off Material and Conduction Delay Conservation

The brain contains a complex network of axons rapidly communicating information between billions of synaptically connected neurons. The morphology of individual axons, therefore, defines the course of information flow within the brain. More than a century ago, Ramón y Cajal proposed that conservation laws to save material (wire) length and limit conduction delay regulate the design of individual axon arbors in cerebral cortex. Yet the spatial and temporal communication costs of single neocortical axons remain undefined. Here, using reconstructions of in vivo labelled excitatory spiny cell and inhibitory basket cell intracortical axons combined with a variety of graph optimization algorithms, we empirically investigated Cajal's conservation laws in cerebral cortex for whole three-dimensional (3D) axon arbors, to our knowledge the first study of its kind. We found intracortical axons were significantly longer than optimal. The temporal cost of cortical axons was also suboptimal though far superior to wire-minimized arbors. We discovered that cortical axon branching appears to promote a low temporal dispersion of axonal latencies and a tight relationship between cortical distance and axonal latency. In addition, inhibitory basket cell axonal latencies may occur within a much narrower temporal window than excitatory spiny cell axons, which may help boost signal detection. Thus, to optimize neuronal network communication we find that a modest excess of axonal wire is traded-off to enhance arbor temporal economy and precision. Our results offer insight into the principles of brain organization and communication in and development of grey matter, where temporal precision is a crucial prerequisite for coincidence detection, synchronization and rapid network oscillations