Irrationality exponent, Hausdorff dimension and effectivization

We generalize the classical theorem by Jarnik and Besicovitch on the irrationality exponents of real numbers and Hausdorff dimension and show that the two notions are independent. For any real number a greater than or equal to 2 and any non-negative real b be less than or equal to 2 / a, we show that there is a Cantor-like set with Hausdorff dimension equal to b such that, with respect to its uniform measure, almost all real numbers have irrationality exponent equal to a. We give an analogous result relating the irrationality exponent and the effective Hausdorff dimension of individual real numbers. We prove that there is a Cantor-like set such that, with respect to its uniform measure, almost all elements in the set have effective Hausdorff dimension equal to b and irrationality exponent equal to a. In each case, we obtain the desired set as a distinguished path in a tree of Cantor sets.Fil: Becher, Veronica Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Investigación en Ciencias de la Computación. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Investigación en Ciencias de la Computación; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Computación; ArgentinaFil: Reimann, Jan. State University of Pennsylvania; Estados UnidosFil: Slaman, Theodore A.. University of California. Department of Mathematics; Estados Unido

Estimating the abundance of clustered and cryptic marine macro-invertebrates in the Galápagos with particular reference to sea cucumbers

Estimating the abundance of marine macro-invertebrates is complicated by a variety of factors: 1) human factors, such as diver efficiency and diver error; and 2) biological factors, such as aggregation of organisms, crypsis, and nocturnal emergence behavior. Diver efficiency varied according to the detectability of an organism causing under-estimation of density by up to 50% in some species. All common species were aggregated at scales from 10-50 m. Transects need to be long enough to transcend the scale of patchiness to improve accuracy. Some species of sea urchins and sea cucumbers (pepinos) which are cryptic by day emerged at night so that daytime censuses underestimated their abundance by up to 10 times. In the sea cucumber fishery, estimates of abundance need to be made at the scale of the population, i.e. at hundreds of km. A strategy for this is proposed

Time decay of scaling critical electromagnetic Schr\"odinger flows

We obtain a representation formula for solutions to Schr\"odinger equations with a class of homogeneous, scaling-critical electromagnetic potentials. As a consequence, we prove the sharp $L^{1}\to L^{\infty}$ time decay estimate for the 3D-inverse square and the 2D-Aharonov-Bohm potentials.Comment: 32 pages, 1 figur

The 3.5 keV Line from Stringy Axions

An interesting result in particle astrophysics is the recent detection of an unexplained 3.5 keV line from galaxy clusters. A promising model, which can explain the morphology of the signal and its non-observation in dwarf spheroidal galaxies, involves a 7 keV dark matter particle decaying into a pair of ultra-light axions that convert into photons in the magnetic field of the clusters. Given that light axions emerge naturally in 4D string vacua, in this paper we present a microscopic realisation of this model within the framework of type IIB flux compactifications. Dark matter is a local closed string axion which develops a tiny mass due to subdominant poly-instanton corrections to the superpotential and couples via kinetic mixing to an almost massless open string axion living on a D3-brane at a singularity. The interaction of this ultra-light axion with photons is induced by U(1) kinetic mixing. After describing the Calabi-Yau geometry and the brane set-up, we discuss in depth moduli stabilisation, the resulting mass spectrum and the strength of all relevant couplings.Comment: 27 pages + appendices, 1 figure; typos corrected, references added, additional comments on the cosmological history and DM production in the conclusion

A computable absolutely normal Liouville number

We give an algorithm that computes an absolutely normal Liouville number.Fil: Becher, Veronica Andrea. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Computación; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Heiber, Pablo Ariel. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Computación; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Slaman, Theodore A.. University of California at Berkeley; Estados Unido

Spectral energy distribution analysis of class i and class ii fu orionis stars

FU Orionis stars (FUors) are eruptive pre-main sequence objects thought to represent quasi-periodic or recurring stages of enhanced accretion during the low-mass star-forming process. We characterize the sample of known and candidate FUors in a homogeneous and consistent way, deriving stellar and circumstellar parameters for each object. We emphasize the analysis in those parameters that are supposed to vary during the FUor stage. We modeled the spectral energy distributions of 24 of the 26 currently known FUors, using the radiative transfer code of Whitney et al. We compare our models with those obtained by Robitaille et al. for Taurus class II and I sources in quiescence periods by calculating the cumulative distribution of the different parameters. FUors have more massive disks: we find that ~80% of the disks in FUors are more massive than any Taurus class II and I sources in the sample. Median values for the disk mass accretion rates are ~10–7 M ☉ yr–1 versus ~10–5 M ☉ yr–1 for standard young stellar objects (YSOs) and FUors, respectively. While the distributions of envelope mass accretion rates for class I FUors and standard class I objects are similar, FUors, on average, have higher envelope mass accretion rates than standard class II and class I sources. Most FUors (~70%) have envelope mass accretion rates above 10–7 M ☉ yr–1. In contrast, 60% of the classical YSO sample has an accretion rate below this value. Our results support the current scenario in which changes experimented by the circumstellar disk explain the observed properties of these stars. However, the increase in the disk mass accretion rate is smaller than theoretically predicted, although in good agreement with previous determinations.Fil: Gramajo, Luciana Veronica. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Cordoba. Observatorio Astronomico de Cordoba; ArgentinaFil: Rodón Javier A.. European Southern Observatory. Santiago; ChileFil: Gomez, Mercedes Nieves. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Cordoba. Observatorio Astronomico de Cordoba; Argentin

A Systematic Review of The Potential Use of Neurofeedback in Patients with Schizophrenia.

Schizophrenia (SCZ) is a neurodevelopmental disorder characterized by positive symptoms (hallucinations and delusions), negative symptoms (anhedonia, social withdrawal) and marked cognitive deficits (memory, executive function, and attention). Current mainstays of treatment, including medications and psychotherapy, do not adequately address cognitive symptoms, which are essential for everyday functioning. However, recent advances in computational neurobiology have rekindled interest in neurofeedback (NF), a form of self-regulation or neuromodulation, in potentially alleviating cognitive symptoms in patients with SCZ. Therefore, we conducted a systematic review of the literature for NF studies in SCZ to identify lessons learned and to identify steps to move the field forward. Our findings reveal that NF studies to date consist mostly of case studies and small sample, single-group studies. Despite few randomized clinical trials, the results suggest that NF is feasible and that it leads to measurable changes in brain function. These findings indicate early proof-of-concept data that needs to be followed up by larger, randomized clinical trials, testing the efficacy of NF compared to well thought out placebos. We hope that such an undertaking by the field will lead to innovative solutions that address refractory symptoms and improve everyday functioning in patients with SCZ

The Impact of the Implementation of Business Intelligent to Support Decision-Making in the American Banking Industry: a Literature Review

In facing globalization era, companies need to have innovation to survive in business competition. A change is needed to make a successful inovation, when a company needs a leader who has a strong managerial ability. The application of technology, in this case is business intelligence (BI), is an innovation that can becarried out by the management leader to survive in the complex world competition by finding appropriate decisions to solve business problems. This article was a literature review that concerned to exploration of the role of leadership and managerial ability in the application of BI on First American Company (FAC). The authors retrieved articles from google scholar with keywords, such as: leadership, managerial ability, and business. The implementation of BI on FAC proves to be a successful innovation formulated by the managementwho manage to change the company's financial situation that loss into a profit and managed to become the market leaders. In addition, this article also presented some cases of successful BI implementation which helped resolving credit problems and segmentatio

Kinetic Study and Characterization of 1,4-β-Endoglucanase of Aspergillus niger ANL301

Submerged fermentation of Aspergillus niger ANL 301 in basal medium containing cellulose as sole carbon source, yielded crude extracellular proteins with 0.54 ± 0.02 units mg protein-1 of 1,4-β-endoglucanase activity. Partial purification by ammonium sulphate precipitation (80% saturation) and gel filtration on Sephadex 25-300 gave two active fractions of 1,4-β-endoglucanase, which exhibited close activity towards carboxymethyl-cellulose (CMC). The pH profile of the pooled enzyme fractions showed three activity peaks at pH 3.5, 5.5 and 7.0. The enzyme was most active at pH 5.5 and showed optimal activity at 50°C. Vmax of 4.4 ± 0.4 µmol min-1 mg protein-1 and Km of 12.5 ± 0.4 gL-1 was obtained with CMC for the enzyme. Different divalent metal ions and EDTA affected the enzyme activity at 2.0 mM concentrations in different ways. Mn2+ and Fe2+ exhibited 253.4 and 24.0% stimulatory effects, respectively on the enzyme activity. Mg2+, Ca2+, Cu2+, and Zn2+ inhibited the enzyme by between 22.3 and 29.4%, whereas 75.0 and 71.3% inhibition were obtained with Hg2+ and EDTA, respectively. Manganese ion showed an exceptional activation of the 1,4-β-endoglucanase. The organism produced two types of 1,4-β-endoglucanase with different molecular weights