The Brauer-Manin Obstruction and Sha[2].

We discuss the Brauer-Manin obstruction on del Pezzo surfaces of degree 4. We outline a detailed algorithm for computing the obstruction and provide associated programs in magma. This is illustrated with the computation of an example with an irreducible cubic factor in the singular locus of the defining pencil of quadrics (in contrast to previous examples, which had at worst quadratic irreducible factors). We exploit the relationship with the Tate-Shafarevich group to give new types of examples of Sha[2], for families of curves of genus 2 of the form y^2 = f(x), where f(x) is a quintic containing an irreducible cubic factor

Effective Hamiltonian Approach to Hyperon Beta Decay with Final-State Baryon Polarization

Using an effective Hamiltonian approach, we obtain expressions for hyperon beta decay final-state baryon polarization. Terms through second order in the energy release are retained. The resulting approximate expressions are much simpler and more compact than the exact expressions, and they agree closely with them.Comment: 1 Figure Will appear in Phys Rev D 60 Article 117505 (Dec 1, 1999

Early Growth and Development Impairments in Patients with Ganglioside GM3 Synthase Deficiency

Ganglioside GM3 synthase is a key enzyme involved in the biosynthesis of gangliosides. GM3 synthase deficiency (GSD) causes a complete absence of GM3 and all downstream biosynthetic derivatives. The individuals affected by this disorder manifest severe irritability, intractable seizures and profound intellectual disability. However, we have found that most newborns seem symptom-free for a period of time after birth. In order to further understand the onset of the disease, we investigated the early growth and development of patients with this condition through this study. We compared 37 affected individuals with their normal siblings and revealed that all children with GSD had relatively normal intrauterine growth and development, as their weight, length and head circumference were similar to their normal siblings at birth. However, the disease progresses quickly after birth and causes significant constitutional impairments of growth and development by 6 months of age. Neither breastfeeding nor gastrostomy tube placement made significant difference on growth and development as all groups of patients showed the similar pattern. We conclude that GSD causes significant postnatal growth and developmental impairments and the amount of gangliosides in breast milk and general nutritional intervention do not seem to alter these outcomes

Кластеризация числовых данных рекуррентной нейронной сетью

Объектом исследования является задача кластеризации многомерных числовых данных. Цель работы – исследование и программная реализация метода кластеризации числовых данных рекуррентной нейронной сетью. В процессе исследования были изучены и проанализированы существующие методики кластеризации. В результате исследования был реализован алгоритм кластеризации анализируемых данных.The object of study is the problem of clustering multidimensional numerical data. The purpose of work – study and software implementation method of clustering numeric data recurrent neural network. In the research process was studied and analyzed existing methods of clustering. The study was implemented clustering algorithm on the analyzed data

Tuberculosis: A Study of Patients in Nigeria Using Binary Logit Models

Purpose: This study aims to examine the influence of age, state, and year on gender of Tuberculosis patients using binary logit modeling. Design/Methodology/Approach: Binary logit models were computed using data sets of registered Tuberculosis patients from 2006 to 2009. Research Findings: Results suggest that males face higher risks for Tuberculosis as compared to females in all age groups, states, and years. In addition, risk variation was observed in age groups, states, and years. Research Limitations/Implications: This study is limited in its analysis to only data sets of registered Tuberculosis patients from 2006 to 2009. Originality/Value: This study contributes to a better understanding of Tuberculosis patients in Nigeria in terms of age, state, year, and gender

Total column CO_2 measurements at Darwin, Australia – site description and calibration against in situ aircraft profiles

An automated Fourier Transform Spectroscopic (FTS) solar observatory was established in Darwin, Australia in August 2005. The laboratory is part of the Total Carbon Column Observing Network, and measures atmospheric column abundances of CO_2 and O_2 and other gases. Measured CO_2 columns were calibrated against integrated aircraft profiles obtained during the TWP-ICE campaign in January–February 2006, and show good agreement with calibrations for a similar instrument in Park Falls, Wisconsin. A clear-sky low airmass relative precision of 0.1% is demonstrated in the CO2 and O2 retrieved column-averaged volume mixing ratios. The 1% negative bias in the FTS X_(CO_2) relative to the World Meteorological Organization (WMO) calibrated in situ scale is within the uncertainties of the NIR spectroscopy and analysis

Classification of Light-Induced Desorption of Alkali Atoms in Glass Cells Used in Atomic Physics Experiments

We attempt to provide physical interpretations of light-induced desorption phenomena that have recently been observed for alkali atoms on glass surfaces of alkali vapor cells used in atomic physics experiments. We find that the observed desorption phenomena are closely related to recent studies in surface science, and can probably be understood in the context of these results. If classified in terms of the photon-energy dependence, the coverage and the bonding state of the alkali adsorbates, the phenomena fall into two categories: It appears very likely that the neutralization of isolated ionic adsorbates by photo-excited electron transfer from the substrate is the origin of the desorption induced by ultraviolet light in ultrahigh vacuum cells. The desorption observed in low temperature cells, on the other hand, which is resonantly dependent on photon energy in the visible light range, is quite similar to light-induced desorption stimulated by localized electronic excitation on metallic aggregates. More detailed studies of light-induced desorption events from surfaces well characterized with respect to alkali coverage-dependent ionicity and aggregate morphology appear highly desirable for the development of more efficient alkali atom sources suitable to improve a variety of atomic physics experiments.Comment: 6 pages, 1 figure; minor corrections made, published in e-Journal of Surface Science and Nanotechnology at http://www.jstage.jst.go.jp/article/ejssnt/4/0/4_63/_articl

Spectroscopic Characteristics of Carbon Dots (C-Dots) Derived from Carbon Fibers and Conversion to Sulfur-Bridged C-Dots Nanosheets

We synthesized sub‐10 nm carbon nanoparticles (CNPs) consistent with photoluminescent carbon dots (C-dots) from carbon fiber starting material. The production of different C-dots fractions was monitored over seven days. During the course of the reaction, one fraction of C-dots species with relatively high photoluminescence was short-lived, emerging during the first hour of reaction but disappearing after one day of reaction. Isolation of this species during the first hour of the reaction was crucial to obtaining higher-luminescent C-dots species. When the reaction proceeded for one week, the appearance of larger nanostructures was observed over time, with lateral dimensions approaching 200 nm. The experimental evidence suggests that these larger species are formed from small C-dot nanoparticles bridged together by sulfur-based moieties between the C-dot edge groups, as if the C-dots polymerized by cross-linking the edge groups through sulfur bridges. Their size can be tailored by controlling the reaction time. Our results highlight the variety of CNP products, from sub‐10 nm C-dots to ~200 nm sulfur-containing carbon nanostructures, that can be produced over time during the oxidation reaction of the graphenic starting material. Our work provides a clear understanding of when to stop the oxidation reaction during the top-down production of C-dots to obtain highly photoluminescent species or a target average particle size