bluuebunny/crossref_metadata_2025 huggingface dataset:
Квадратурные формулы Гаусса и Маркова по нулям собственных функций задачи Штурма-Лиувилля, точные для целых функций экспоненциального типа
Authors: Gorbachev Dmitry Viktorovich , Ivanov Valerii Ivanovich
Published: September 2015

Доказываются квадратурные формулы Гаусса и Маркова по нулям собственных функций задачи Штурма-Лиувилля, точные для целых функций экспоненциального типа. Они обобщают квадратурные формулы по нулям функций Бесселя, впервые построенные К. Фрапье и П. Оливье. Квадратуры Бесселя отвечают интегральному
преобразованию Фурье-Ганкеля. Приводятся другие примеры, связанные с интегральным преобразованием Якоби, рядом Фурье по ортогональным многочленам Якоби и общей задачей Штурма-Лиувилля с регулярным весом.
Библиография: 39 названий.
О спектральном синтезе на поэлементно компактных абелевых группах
Authors: Platonov Sergei Sergeevich
Published: September 2015

Пусть $G$ - произвольная локально компактная абелева группа, $C(G)$ - пространство всех непрерывных комплекснозначных функций на группе $G$. Замкнутое линейное подпространство $\mathscr H\subseteq C(G)$ называется инвариантным подпространством, если оно инвариантно относительно сдвигов $\tau_y\colon f(x)\mapsto f(xy)$, $y\in G$. По определению инвариантное подпространство $\mathscr H\subseteq C(G)$ допускает строгий спектральный синтез, если $\mathscr H$ совпадает с замыканием в $C(G)$ линейной оболочки всех
содержащихся в $\mathscr H$ характеров группы $G$. Будем говорить, что на группе $G$ справедлив
строгий спектральный синтез в пространстве $C(G)$, если любое инвариантное подпространство
$\mathscr H\subseteq C(G)$ допускает строгий спектральный синтез. Элемент $x$ топологической группы $G$ называется компактным, если $x$ содержится в некоторой компактной подгруппе группы $G$. Группа $G$ называется поэлементно компактной, если все элементы этой группы компактны. Основным результатом статьи является доказательство того, что на локально компактной абелевой группе $G$ справедлив строгий спектральный синтез в пространстве $C(G)$ тогда и только тогда, когда группа $G$ поэлементно компактная.
Библиография: 14 названий.
Cуществование полуправильных решений эллиптических спектральных задач с разрывными нелинейностями
Authors: Pavlenko Vyacheslav Nikolaevich , Potapov Dmitriy Konstantinovich
Published: September 2015

Рассматривается проблема существования полуправильных решений задачи Дирихле для уравнения эллиптического типа с разрывной нелинейностью без условия формальной самосопряженности
дифференциального оператора. Доказаны теоремы о существовании полуправильных (положительных и
отрицательных) решений для исследуемой задачи, получен принцип верхних и нижних решений существования полуправильных решений. Установлено существование нетривиальных полуправильных (положительных и отрицательных) решений эллиптических спектральных задач с разрывными нелинейностями при положительных значениях спектрального параметра.
Библиография: 32 названия.
Оценки интегральных норм многочленов на пространствах с выпуклыми мерами
Authors: Arutyunyan Lavrentin Martunovich , Kosov Egor Dmitrievich
Published: September 2015

В работе доказано, что измеримые многочлены степени $d$ интегрируемы по выпуклой мере в любой положительной степени, а все их $L^p$-нормы эквивалентны. Также доказывается закон нуля или единицы для множеств уровня измеримых многочленов и множеств сходимости измеримых многочленов на пространствах с выпуклыми мерами. Для непрерывных многочленов получена оценка $L^1$-нормы через $L^1$-норму их сужений на какое-либо множество положительной меры.
Библиография: 19 названий.
Существование решений анизотропных эллиптических уравнений с нестепенными нелинейностями в неограниченных областях
Authors: Kozhevnikova Larisa Mikhailovna , Khadzhi Anna Alexandrovna
Published: September 2015

Работа посвящена исследованию разрешимости задачи Дирихле для некоторого класса анизотропных эллиптических уравнений второго порядка дивергентного вида с младшими членами и нестепенными
нелинейностями
$$
\sum_{\alpha=1}^{n}(a_{\alpha}(x,u,\nabla u))_{x_{\alpha}}-a_0(x,u,\nabla u)=0,
\qquad
x \in \Omega.
$$
На каратеодориевы функции $a_{\alpha}(x,s_0,s)$, $\alpha=0,1,…,n$, накладывается условие совокупной монотонности по аргументам $s_0\in\mathbb{R}$, $s\in\mathbb{R}_n$. Ограничения на их рост по $s_0,s$ формулируются в терминах специального класса выпуклых функций. Изучаются условия существования решений задачи Дирихле в неограниченных областях $\Omega\subset \mathbb{R}_n$, $n\geqslant 2$. Доказана теорема существования без ограничений на поведение решений и рост исходных данных при $|x|\to \infty$.
Библиография: 26 названий.
Многомерный символ Конту-Каррера: локальная теория
Authors: Gorchinskiy Sergey Olegovich , Osipov Denis Vasilievich
Published: September 2015

Строится многомерный символ Конту-Каррера и изучаются его различные фундаментальные свойства. Многомерный символ Конту-Каррера определяется при помощи граничного отображения для $K$-групп. Доказывается его универсальное свойство. Приводится явная формула для многомерного символа Конту-Каррера
над $\mathbb Q$ и доказывается целочисленность этой формулы. Изучена связь с многомерным спариванием Витта.
Библиография: 46 названий.
О некоторых медленно сходящихся системах преобразований термов
Authors: Beklemishev Lev Dmitrievich , Onoprienko Anastasiya Aleksandrovna
Published: September 2015

Формулируются системы преобразований термов, число шагов работы которых на произвольном входе конечно, но не ограничивается никакой вычислимой функцией, доказуемо тотальной в арифметике Пеано $\mathsf{PA}$. Тем самым, утверждение о сходимости таких систем не доказуемо в $\mathsf{PA}$. Эти системы получаются из независимого комбинаторного утверждения, известного как принцип червя; их также можно рассматривать как вариант хорошо известной игры Геракла и гидры, введенной Дж. Парисом и Л. Кирби.
Библиография: 16 названий.
Полная классификация сферически-симметричных статических пространств-времен с помощью симметрий Нeтер
Authors: Ali Farhad , Feroze Tooba , Ali Sajid
Published: September 2015

Приведена полная классификация сферически-симметричных статических пространств-времен по их симметриям Нeтер. Уравнения, определяющие симметрии Нeтер, получены с помощью обычного лагранжиана общего сферически-симметричного пространства-времени и интегрируются в каждом рассмотренном случае. В частности, обнаружено, что сферически-симметричные статические пространства-времена можно распределить по шести различным классам, соответствующим алгебрам Нeтер размерностей 5, 6, 7, 9, 11 и 17. С помощью теоремы Нeтер найдены также первые интегралы, соответствующие каждой симметрии. Кроме того, получены некоторые новые сферически-симметричные статические решения.
Алгебраические квантовые гамильтонианы на плоскости
Authors: Sokolov Vladimir Vyacheslavovich
Published: September 2015

Рассматриваются дифференциальные операторы $P$ второго порядка с полиномиальными коэффициентами, сохраняющие для некоторого $n$ пространство многочленов степени не выше $n$. Метрика, соответствующая символу $P$, предполагается плоской, а сам оператор $P$ - потенциальным. В случае двух независимых переменных получены некоторые классификационные результаты. В процессе классификации найдены полиномиальные формы для эллиптических $A_2$- и $G_2$-операторов Калоджеро-Мозера и для эллиптической модели Иноземцева.
Действие как инвариант преобразований Беклунда лагранжевых систем
Authors: Marikhin Vladimir Georgievich
Published: September 2015

Построена общая теория преобразований Беклунда лагранжевых систем при условии, что действие сохраняется при применении этих преобразований. Обсуждаются известные преобразования Беклунда для классических солитонных уравнений с точки зрения этого подхода. Получено новое преобразование Беклунда для уравнения Цицейки.
Принципы больших уклонений для траектории обобщенных процессов восстановления. I
Authors: Borovkov Alexander Alekseevich , Mogul'skii Anatolii Al'fredovich
Published: September 2015

Настоящая работа продолжает исследования принципов больших уклонений обобщенных процессов восстановления, начатые в [1], [2]. Основным объектом изучения являются вероятности больших уклонений траекторий обобщенных процессов восстановления. Работа состоит из двух частей. В части I при некотором
условии на распределение процесса получен так называемый первый частичный локальный принцип больших уклонений для траекторий обобщенного процесса восстановления. В части II при альтернативном условии получен второй частичный локальный принцип больших уклонений. При дополнительных условиях получены
также "полный локальный" и "полный интегральный" принципы больших уклонений для обобщенных процессов восстановления.
О структуре функционала накопления, построенного на траекториях полумарковского процесса с конечным множеством состояний
Authors: Kashtanov Viktor Alekseevich
Published: September 2015

В работе исследуется структура функционала накопления, построенного на траекториях управляемого полумарковского процесса с конечным множеством состояний. При $t\to\infty$ этот функционал линейно растет и коэффициент есть дробно-линейный функционал относительно вероятностных мер, определяющих марковскую
однородную рандомизированную стратегию управления.
О построении асимптотических разложений высокой точности
Authors: Senatov Vladimir Vasil'evich
Published: September 2015

Предложены новые асимптотические разложения в центральной предельной теореме, позволяющие аппроксимировать распределения нормированных сумм независимых случайных величин с точностью, которая на несколько порядков превосходит точность оценки теоремы Берри-Эссеена.
CLT for linear spectral statistics of Hermitian Wigner matrices with general moment conditions
Authors: Bao Z , Xie Junshan
Published: September 2015

Изучается эрмитова матрица Вигнера $W_n=(x_{ij})_{1\leq i,j\leq n}$ с независимыми (с точностью до симметрии) внедиагональными элементами, имеющими нулевое среднее и единичную дисперсию. При
некотором условии типа Линдеберга на четвертые моменты элементов матрицы доказана центральная предельная теорема для линейных статистик собственных значений матрицы $W_n$. Наш результат распространяет предыдущие результаты подобного рода на более общий случай, когда отсутствует ограничение $\bf E x^2_{ij}=0$ для $1\leq i < j \leq n$. Вместо этого мы предполагаем только, что вещественная и мнимая части наддиагональных элементов некоррелированы. Более точно, мы требуем, чтобы математические ожидания
$\bf E x^2_{ij}$ были вещественными и однородными для всех $1\leq i < j \leq n$. Показано, что предельное нормальное распределение в центральной предельной теореме зависит от параметра $\bf E x^2_{ij}\in [-1,1]$.
Оценка радиуса окрестности взаимодействия для марковского случайного поля
Authors: Bulinski Alexander Vadimovich
Published: September 2015

Рассматривается марковское случайное поле $X$, отвечающее конечному графу $G$. Вершины этого графа лежат в некотором метрическом пространстве. Значения элементов поля принадлежат произвольному конечному множеству. Вероятностное распределение поля предполагается строго положительным на непустых конфигурациях. Иначе говоря (согласно теореме Аверинцева-Клиффорда-Хаммерсли), изучается гиббсовское случайное поле с потенциалом ближайших соседей. Для каждой вершины $j$ графа $G$ исследуется почти наверное предельное поведение статистических оценок радиуса минимального шара, содержащего соседние с $j$ вершины. Эти оценки строятся по выборке независимых случайных полей, имеющих такое же распределение, как данное поле $X$.
Тауберова теорема для производящих функций кратных последовательностей
Authors: Yakymiv Arsen Lubomirovich
Published: September 2015

Рассматриваются кратные последовательности $a(i) \geq 0, i \in \bf Z^n_+$. Вводится понятие односторонней слабой осцилляции таких последовательностей вдоль последовательности $(m = m(k) = (m_1(k),\ldots,m_n(k))),
m_j(k)>0\forall j = 1,\ldots, n, k \in \bf N$, такой, что $m_j(k)\to\infty$ при $k\to\infty$. Из асимптотики производящей функции $A(s), s\in [0, 1)^n$, изучаемой кратной последовательности при $s = (e^{-\lambda_1/m_1},\ldots, e^{-\lambda_n/m_n})$ и $k\to\infty$ ($\lambda_1,\ldots,\lambda_n$ положительны и фиксированы) выводится асимптотика для $a(x_1m_1,\ldots,x_nm_n)$ (числа $x_1,\ldots, x_n$ положительны и фиксированы). Полученная тауберова теорема обобщает несколько тауберовых теорем, доказанных автором ранее при исследовании некоторых классов случайных подстановок и случайных отображений конечного множества в себя. При этом исходным результатом в этом направлении является известная тауберова теорема Йована Караматы для производящих функций последовательностей.
A methodology for investigating dust model performance using synergistic EARLINET/AERONET dust concentration retrievals
Authors: Binietoglou I. , Basart S. , Alados-Arboledas L. , Amiridis V. , Argyrouli A. , Baars H. , Baldasano J. M. , Balis D. , Belegante L. , Bravo-Aranda J. A. , Burlizzi P. , Carrasco V. , Chaikovsky A. , Comerón A. , D'Amico G. , Filioglou M. , Granados-Muñoz M. J. , Guerrero-Rascado J. L. , Ilic L. , Kokkalis P. , Maurizi A. , Mona L. , Monti F. , Muñoz-Porcar C. , Nicolae D. , Papayannis A. , Pappalardo G. , Pejanovic G. , Pereira S. N. , Perrone M. R. , Pietruczuk A. , Posyniak M. , Rocadenbosch F. , Rodríguez-Gómez A. , Sicard M. , Siomos N. , Szkop A. , Terradellas E. , Tsekeri A. , Vukovic A. , Wandinger U. , Wagner J.
Published: September 2015

Abstract. Systematic measurements of dust concentration profiles at a continental scale were recently made possible by the development of synergistic retrieval algorithms using combined lidar and sun photometer data and the establishment of robust remote-sensing networks in the framework of Aerosols, Clouds, and Trace gases Research InfraStructure Network (ACTRIS)/European Aerosol Research Lidar Network (EARLINET). We present a methodology for using these capabilities as a tool for examining the performance of dust transport models. The methodology includes considerations for the selection of a suitable data set and appropriate metrics for the exploration of the results. The approach is demonstrated for four regional dust transport models (BSC-DREAM8b v2, NMMB/BSC-DUST, DREAMABOL, DREAM8-NMME-MACC) using dust observations performed at 10 ACTRIS/EARLINET stations. The observations, which include coincident multi-wavelength lidar and sun photometer measurements, were processed with the Lidar-Radiometer Inversion Code (LIRIC) to retrieve aerosol concentration profiles. The methodology proposed here shows advantages when compared to traditional evaluation techniques that utilize separately the available measurements such as separating the contribution of dust from other aerosol types on the lidar profiles and avoiding model assumptions related to the conversion of concentration fields to aerosol extinction values. When compared to LIRIC retrievals, the simulated dust vertical structures were found to be in good agreement for all models with correlation values between 0.5 and 0.7 in the 1–6 km range, where most dust is typically observed. The absolute dust concentration was typically underestimated with mean bias values of -40 to -20 μg m−3 at 2 km, the altitude of maximum mean concentration. The reported differences among the models found in this comparison indicate the benefit of the systematic use of the proposed approach in future dust model evaluation studies.
The 3He flux gauge in the Sargasso Sea: a determination of physical nutrient fluxes to the euphotic zone at the Bermuda Atlantic Time-series Site
Authors: Stanley R. H. R. , Jenkins W. J. , Doney S. C. , Lott III D. E.
Published: September 2015

Abstract. Significant rates of primary production occur in the oligotrophic ocean, without any measurable nutrients present in the mixed layer, fueling a scientific paradox that has lasted for decades. Here, we provide a new determination of the annual mean physical supply of nitrate to the euphotic zone in the western subtropical North Atlantic. We combine a 3-year time series of measurements of tritiugenic 3He from 2003 to 2006 in the surface ocean at the Bermuda Atlantic Time-series Study (BATS) site with a sophisticated noble gas calibrated air–sea gas exchange model to constrain the 3He flux across the sea–air interface, which must closely mirror the upward 3He flux into the euphotic zone. The product of the 3He flux and the observed subsurface nitrate–3He relationship provides an estimate of the minimum rate of new production in the BATS region. We also apply the gas model to an earlier time series of 3He measurements at BATS in order to recalculate new production fluxes for the 1985 to 1988 time period. The observations, despite an almost 3-fold difference in the nitrate–3He relationship, yield a roughly consistent estimate of nitrate flux. In particular, the nitrate flux from 2003 to 2006 is estimated to be 0.65 ± 0.14 mol m−2 yr−1, which is ~40 % smaller than the calculated flux for the period from 1985 to 1988. The difference in nitrate flux between the time periods may be signifying a real difference in new production resulting from changes in subtropical mode water formation. Overall, the nitrate flux is larger than most estimates of export fluxes or net community production fluxes made locally for the BATS site, which is likely a reflection of the larger spatial scale covered by the 3He technique and potentially also by the decoupling of 3He and nitrate during the obduction of water masses from the main thermocline into the upper ocean. The upward nitrate flux is certainly large enough to support observed rates of primary production at BATS and more generally in the oligotrophic subtropical ocean.
Autotrophic fixation of geogenic CO2 by microorganisms contributes to soil organic matter formation and alters isotope signatures in a wetland mofette
Authors: Nowak M. E. , Beulig F. , von Fischer J. , Muhr J. , Küsel K. , Trumbore S. E.
Published: September 2015

Abstract. To quantify the contribution of autotrophic microorganisms to organic matter formation (OM) in soils, we investigated natural CO2 vents (mofettes) situated in a wetland in NW Bohemia (Czech Republic). Mofette soils had higher SOM concentrations than reference soils due to restricted decomposition under high CO2 levels. We used radiocarbon (Δ14C) and stable carbon isotope ratios (δ13C) to characterize SOM and its sources in two moffetes and compared it with respective reference soils, which were not influenced by geogenic CO2. The geogenic CO2 emitted at these sites is free of radiocarbon and enriched in δ13C compared to atmospheric CO2. Together, these isotopic signals allow us to distinguish C fixed by plants from C fixed by autotrophic microorganisms using their differences in δ13C discrimination. We can then estimate that up to 27 % of soil organic matter in the 0–10 cm layer of these soils was derived from microbially assimilated CO2. Isotope values of bulk SOM were shifted towards more positive δ13C and more negative Δ14C values in mofettes compared to reference soils, suggesting that geogenic CO2 emitted from the soil atmosphere is incorporated into SOM. To distinguish whether geogenic CO2 was fixed by plants or by CO2 assimilating microorganisms, we first used the proportional differences in radiocarbon and δ13C values to indicate the magnitude of discrimination of the stable isotopes in living plants. Deviation from this relationship was taken to indicate the presence of microbial CO2 fixation, as microbial discrimination should differ from that of plants. 13CO2-labelling experiments confirmed high activity of CO2 assimilating microbes in the top 10 cm, where δ13C values of SOM were shifted up to 2 ‰ towards more negative values. Uptake rates of microbial CO2 fixation ranged up to 1.59 ± 0.16 μg gdw−1 d−1. We inferred that the negative δ13C shift was caused by the activity of chemo-lithoautotrophic microorganisms, as indicated from quantification of cbbL/cbbM marker genes encoding for RubisCO by quantitative polymerase chain reaction (qPCR) and by acetogenic and methanogenic microorganisms, shown present in the moffettes by previous studies. Combined Δ14C and δ13C isotope mass balances indicated that microbially derived carbon accounted for 8 to 27 % of bulk SOM in this soil layer. The findings imply that autotrophic organisms can recycle significant amounts of carbon in wetland soils and might contribute to observed reservoir effects influencing radiocarbon signatures in peat deposits.
Brief Communication: Use of field test kit for detection of lead in drinking water in Philippines post the disaster typhoon Haiyan
Authors: Liu K. Y. , Cong L. M. , Lan Z. J. , Ma R. P. , Yu L. , Song Q. , Wang Y. F. , Ren S. , Lu B. N. , Deng R. S. , Li G. R. , Li W. P.
Published: September 2015

Abstract. On 8 November 2013, super typhoon Haiyan made landfall in Philippines. On 24 November, the Chinese hospital ship arrived in Philippines to help with disaster relief efforts. Drinking water was collected at a variety of locations, and the concentration levels of lead were determined with field test kit. The results showed that the levels of lead in 67% of total collected water samples exceeded WHO's standard. Afterwards, the local government had taken many measures to ensure a safe water supply in next few months. This is the first report about water quality in Philippines after the disaster.
The European lightning location system EUCLID – Part 1: Performance validation
Authors: Schulz W. , Diendorfer G. , Pedeboy S. , Poelman D. R.
Published: September 2015

Abstract. In this paper we present a performance analysis of the European lightning location system EUCLID in terms of location accuracy (LA), detection efficiency (DE) and peak current estimation. The performance analysis is based on ground truth data from direct lightning current measurements at the Gaisberg Tower (GBT) and data from E-field and video recordings. The E-field and video recordings were collected in three different regions in Europe, namely in Austria, Belgium, and France. The analysis shows a significant improvement of the LA of the EUCLID network over the past seven years. Currently, the median LA is in the range of 100 m. The observed DE in Austria and Belgium is similar, yet a slightly lower DE is determined in a particular region in France, due to malfunctioning of a relevant lightning location sensor during the time of observation. The overall accuracy of the lightning location system (LLS) peak current estimation for subsequent strokes is reasonable keeping in mind that the LLS estimated peak currents are determined from the radiated electromagnetic fields, assuming a constant return stroke speed. The results presented in this paper can be used to estimate the performance of the EUCLID network for regions with similar sensor baselines and sensor technology.
The European lightning location system EUCLID – Part 2: Observations
Authors: Poelman D. R. , Schulz W. , Diendorfer G. , Bernardi M.
Published: September 2015

Abstract. Cloud-to-ground (CG) lightning data from the European Cooperation for Lightning Detection (EUCLID) network over the period 2006–2014 are explored. Mean CG flash densities vary over the European continent, with the highest density of about 6 km−2 yr−1 found at the triple point between Austria, Italy and Slovenia. The majority of lightning activity takes place between May and September, accounting for 85 % of the total observed CG activity. Furthermore, the thunderstorm season reaches its highest activity in July, while the diurnal cycle peaks around 15:00 UTC. A difference between CG flashes over land and sea becomes apparent when looking at the peak current estimates. It is found that flashes with higher peak currents occur in greater numbers over sea than over land.
Quantifying the resolution level where the GRACE satellites can separate Greenland's glacial mass balance from surface mass balance
Authors: Bonin J. A. , Chambers D. P.
Published: September 2015

Abstract. Mass change over Greenland can be caused by either changes in the glacial dynamic mass balance (DMB) or the surface mass balance (SMB). The GRACE satellite gravity mission cannot directly separate the two physical causes because it measures the sum of the entire mass column with limited spatial resolution. We demonstrate one theoretical way to indirectly separate cumulative SMB from DMB with GRACE, using a least squares inversion technique with knowledge of the location of the glaciers. However, we find that the limited 60 × 60 spherical harmonic representation of current GRACE data does not provide sufficient resolution to adequately accomplish the task. We determine that at a maximum degree/order of 90 × 90 or above, a noise-free gravity measurement could theoretically separate the SMB from DMB signals. However, current GRACE satellite errors are too large at present to separate the signals. A noise reduction of a factor of 10 at a resolution of 90 × 90 would provide the accuracy needed for the interannual cumulative SMB and DMB to be accurately separated.
El vínculo entre sociedad, profesores y estudiantes en los posgrados
Authors: Antonio Ramos Marco
Published: September 2015

Revista Portal de la Ciencia, No. 7, diciembre 2014; 3-9
Frecuencia de granuloma periapical y quiste radicular diagnóstico histopatológico posextracción dental en la Facultad de Odontología, UNAH
Authors: Sierra David , Aguilar Ricardo
Published: September 2015

El objetivo de esta investigación es identificar la frecuencia y ubicación del granuloma periapical y quiste radicular realizando un estudio histopatológico posextracción dental en la Facultad de Odontología de la UNAH. Para lograrlo se recolectaron 97 lesiones periapicales con criterio de exodoncia indicada por estudio radiográfico con destrucción ósea periapical mayor de 1.5 mm; dichas biopsias fueron fijadas en formalina buferada, a las cuales se les realizó un estudio histopatológico.Los datos se tomaron de las historias clínicas y fichas de registro realizadas a los pacientes después de extraer el órgano dental afectado, posteriormente se introdujeron los datos al programa estadístico SPSS versión 19 para su análisis.Los resultados indican que el diagnóstico más frecuente corresponde al quiste radicular con el 53.6 %, el género femenino es el más afectado con un 55.6 %, en la tercera década de vida hay una mayor presencia de quiste radicular en un 18.5 % de las 97 muestras. Esta investigación proporciona información al personal de odontología para la detección, diagnóstico, manejo y seguimiento de las lesiones periapicales.Revista Portal de la Ciencia, No. 7, diciembre 2014; 23-33
Condiciones de trabajo con respecto a la salud ocupacional de las empleadas de higienización de la UNAH
Authors: Molina Fonseca Yolanda Argentina , Hernández Rodríguez Ana Corina
Published: September 2015

El propósito de este artículo es dar a conocer los resultados que se obtuvieron en la investigación realizada sobre la salud ocupacional de las empleadas de la Universidad Nacional Autónoma de Honduras (UNAH), cuyo objetivo general fue analizar las condiciones de trabajo con respecto a la salud ocupacional de las empleadas de higienización de la UNAH.En el estudio se caracterizaron las condiciones en que desempeñan su labor las empleadas de higienización de la UNAH y resultados obtenidos reflejan que estas condiciones representan riesgos por accidentes o enfermedades profesionales. Asimismo, se elaboró un perfil actual de salud de la población estudiada, en el cual prevalecen las enfermedades músculo-esqueléticas, alergias respiratorias y dermatológicas.La metodología utilizada para llevar a cabo la investigación fue de tipo cualitativa. La selección de las unidades primarias a quienes se les hizo la entrevista a profundidad fue intencionada al momento de hacer las agrupaciones de acuerdo al año de ingreso a laborar en la institución y de forma aleatoria se seleccionó a una persona por agrupación.En respuesta a esta problemática, el estudio identificó algunas acciones de protección, tales como el uso de guantes y mascarillas, aunque este último implemento no lo usan con la regularidad necesaria. Las acciones de reacción encontradas en el estudio son: reducción de las actividades laborales, cambio de actividades laborales y traslados a otros departamentos en la misma jornada de trabajo.Revista Portal de la Ciencia, No. 7, diciembre 2014; 51-61
La productividad, un pilar importante en la ventaja competitiva de las organizaciones: una perspectiva para la gestión de los factores que influyen en la productividad empresarial
Authors: Raya Hernández Manuel Arturo , Núñez Rafael
Published: September 2015

El presente trabajo tiene como objetivo mostrar la necesidad de ver a la productividad como un pilar de la ventaja competitiva en la actividad empresarial, también se espera compartir el significado de los términos antes mencionados y con ello facilitar cualquier propuesta o estrategia para implementar cualquier método o técnica que favorezca los índices de productividad y así demostrar que se está trabajando en la mejora continua y con esto obtener una ventaja competitiva.Para tal propósito, se realizó una investigación aplicando una encuesta a 10 gerentes de nivel medio, en 10 empresas distintas, para conocer su nivel de conocimiento y manejo sobre temas de productividad y mejora continua. Los resultados obtenidos indican que hay una serie de problemas comunes al momento de aplicar las técnicas de mejora: no hay un seguimiento, no hay un compromiso, hay poca motivación y hay una falta de apoyo por parte de la alta gerencia.Revista Portal de la Ciencia, No. 7, diciembre 2014; 77-88
La relación entre el nivel pobreza, la tasa de analfabetismo y el ingreso per cápita en Honduras, 2006-2011
Authors: Hernández César Yanuario , Malta Joseph
Published: September 2015

El presente artículo muestra los resultados del análisis de la relación existente entre los niveles de pobreza, la tasa de analfabetismo y el ingreso per cápita a nivel nacional, para el período 2006-2011. Los productos fueron obtenidos a partir de la utilización de la metodología de las bases de estadística de la encuesta permanente de hogares de propósitos múltiples (EPHPM-Mayo).Se resalta la tendencia de la pobreza, el analfabetismo y el ingreso per cápita; lo importante en todo esto son los comportamientos que han venido mostrando estos aspectos y la explicación del fenómeno de la pobreza. Así, se deduce de forma general, que la pobreza en Honduras está vinculada al tema de educación e ingreso. Además, existen otros aspectos que la determinan, que para propósitos de esta investigación se ha reducido a la tasa de analfabetismo y al ingreso per cápita.No obstante, esto no quiere decir que estos parámetros sean los más apropiados para explicar de manera precisa la pobreza, ya que por naturaleza es un tema complejo de analizar. En esencia, lo que se busca es mostrar el comportamiento de la pobreza en nuestro país y su relación con la educación y el ingreso.Revista Portal de la Ciencia, No. 7, diciembre 2014; 131-152
Using QR Codes in Classrooms
Authors: Cetner Michelle
Published: September 2015

For years, many schools and districts have had strict policies banning the use of students' personal electronic devices in classrooms. However, some schools are beginning to embrace the educational value of handheld Web-enabled devices that students already bring to school each day. As teachers begin to explore the educational opportunities that smartphones and other devices offer, we need to remember that the utility of any tool is only as good as our understanding of how to use that tool. This article attempts to introduce two simple ways in which QR codes can be used successfully in the classroom.
The Coffee-Milk Mixture Problem Revisited
Authors: Marion Charles F.
Published: September 2015

Recently, I had occasion to re-read George Pólya's (1957) classic work on problem solving in mathematics, How to Solve It. Early in the book, Pólya describes the different phases of problem solving, including the fourth and final phase— “looking back.” Describing that phase, he writes:
Epidemics, Exponential Functions, and Modeling
Authors: Gibbons Katie , Karp Karen S. , Dillon Fred
Published: September 2015

The phenomenon of a plague intrigues students and provides a visual model that demonstrates growth.
Artist? Mathematician? Developing Both Enhances Learning!
Authors: Bush Sarah B. , Karp Karen S. , Nadler Jennifer
Published: September 2015

This department publishes brief news articles, announcements and guest editorials on current mathematics education issues that stimulate the interest of TCM readers and cause them to think about an issue or consider a specific viewpoint about some aspect of mathematics education.
Extracellular Vesicles Improve Post-Stroke Neuroregeneration and Prevent Postischemic Immunosuppression
Authors: Doeppner Thorsten R. , Herz Josephine , Görgens André , Schlechter Jana , Ludwig Anna-Kristin , Radtke Stefan , de Miroschedji Kyra , Horn Peter A. , Giebel Bernd , Hermann Dirk M.
Published: September 2015

Although the initial concepts of stem cell therapy aimed at replacing lost tissue, more recent evidence has suggested that stem and progenitor cells alike promote postischemic neurological recovery by secreted factors that restore the injured brain's capacity to reshape. Specifically, extracellular vesicles (EVs) derived from stem cells such as exosomes have recently been suggested to mediate restorative stem cell effects. In order to define whether EVs indeed improve postischemic neurological impairment and brain remodeling, we systematically compared the effects of mesenchymal stem cell (MSC)-derived EVs (MSC-EVs) with MSCs that were i.v. delivered to mice on days 1, 3, and 5 (MSC-EVs) or on day 1 (MSCs) after focal cerebral ischemia in C57BL6 mice. For as long as 28 days after stroke, motor coordination deficits, histological brain injury, immune responses in the peripheral blood and brain, and cerebral angiogenesis and neurogenesis were analyzed. Improved neurological impairment and long-term neuroprotection associated with enhanced angioneurogenesis were noticed in stroke mice receiving EVs from two different bone marrow-derived MSC lineages. MSC-EV administration closely resembled responses to MSCs and persisted throughout the observation period. Although cerebral immune cell infiltration was not affected by MSC-EVs, postischemic immunosuppression (i.e., B-cell, natural killer cell, and T-cell lymphopenia) was attenuated in the peripheral blood at 6 days after ischemia, providing an appropriate external milieu for successful brain remodeling. Because MSC-EVs have recently been shown to be apparently safe in humans, the present study provides clinically relevant evidence warranting rapid proof-of-concept studies in stroke patients.

Significance

Transplantation of mesenchymal stem cells (MSCs) offers an interesting adjuvant approach next to thrombolysis for treatment of ischemic stroke. However, MSCs are not integrated into residing neural networks but act indirectly, inducing neuroprotection and promoting neuroregeneration. Although the mechanisms by which MSCs act are still elusive, recent evidence has suggested that extracellular vesicles (EVs) might be responsible for MSC-induced effects under physiological and pathological conditions. The present study has demonstrated that EVs are not inferior to MSCs in a rodent stroke model. EVs induce long-term neuroprotection, promote neuroregeneration and neurological recovery, and modulate peripheral post-stroke immune responses. Also, because EVs are well-tolerated in humans, as previously reported, the administration of EVs under clinical settings might set the path for a novel and innovative therapeutic stroke concept without the putative side effects attached to stem cell transplantation.
Wss1 metalloprotease partners with Cdc48/Doa1 in processing genotoxic SUMO conjugates
Authors: Balakirev Maxim Y , Mullally James E , Favier Adrien , Assard Nicole , Sulpice Eric , Lindsey David F , Rulina Anastasia V , Gidrol Xavier , Wilkinson Keith D
Published: September 2015

Sumoylation during genotoxic stress regulates the composition of DNA repair complexes. The yeast metalloprotease Wss1 clears chromatin-bound sumoylated proteins. Wss1 and its mammalian analog, DVC1/Spartan, belong to minigluzincins family of proteases. Wss1 proteolytic activity is regulated by a cysteine switch mechanism activated by chemical stress and/or DNA binding. Wss1 is required for cell survival following UV irradiation, the smt3-331 mutation and Camptothecin-induced formation of covalent topoisomerase 1 complexes (Top1cc). Wss1 forms a SUMO-specific ternary complex with the AAA ATPase Cdc48 and an adaptor, Doa1. Upon DNA damage Wss1/Cdc48/Doa1 is recruited to sumoylated targets and catalyzes SUMO chain extension through a newly recognized SUMO ligase activity. Activation of Wss1 results in metalloprotease self-cleavage and proteolysis of associated proteins. In cells lacking Tdp1, clearance of topoisomerase covalent complexes becomes SUMO and Wss1-dependent. Upon genotoxic stress, Wss1 is vacuolar, suggesting a link between genotoxic stress and autophagy involving the Doa1 adapter.
Can we properly model the neutron monitor count rate?
Authors: Gil Agnieszka , Usoskin Ilya G. , Kovaltsov Gennady A. , Mishev Alexander L. , Corti Claudio , Bindi Veronica
Published: September 2015

Neutron monitors provide continuous measurements of secondary nucleonic particles produced in the atmosphere by the primary cosmic rays and form the main tool to study the heliospheric modulation of cosmic rays. In order to study cosmic rays using the world network of neutron monitor and needs to be able to model the neutron monitor count rate. Earlier it was difficult because of the poorly known yield function, which has been essentially revisited recently. We have presented a verification of the new yield function of the standard neutron monitor (NM) using a recently released data on the direct in situ measurements of the galactic cosmic rays energy spectrum during 2006–2009 (the period of the record high cosmic ray flux) by Payload for Antimatter Matter Exploration and Light‐nuclei Astrophysics spaceborne spectrometer, and on NM latitude surveys performed during the period of 1994–2007, including periods of high solar activity. We found a very good agreement between the measured count rates of sea level NMs and the modeled ones in very different conditions: from low to high solar activity and from polar to tropical regions. This implies that the count rate of a sea level neutron monitor can be properly modeled in all conditions, using the new yield function.
Autobiographical Memory and Depression: Identity‐continuity and Problem‐solving Functions Indirectly Predict Symptoms over Time through Psychological Well‐being
Authors: Hallford David John , Mellor David
Published: September 2015

The aim of this study was to assess the longitudinal associations between adaptive autobiographical memory functions and depressive symptoms. Consistent with the proposed mechanisms of change underpinning cognitive‐reminiscence therapy (CRT), it was hypothesised that more frequent adaptive reminiscence would lead to increases in psychological resources over time and indirectly affect depressive symptoms through this pathway. A sample of 171 young adults (mean age = 25.9 years, SD = 3.5) completed measures of how frequently they utilised autobiographical memory for identity‐continuity and problem‐solving purposes, depressive symptoms and personal resources (self‐esteem, self‐efficacy, meaning in life and optimism) at two time‐points. The results of structural equation modelling supported the model of indirect influence between reminiscence functions and depression through these psychological resources. These findings clarify the effects of adaptive autobiographical memory on depressive symptoms in young adults and indicate potential benefits of interventions such as CRT. Copyright © 2015 John Wiley & Sons, Ltd.
Processing Map Development through Elaborating Phenomenological and Physical Constitutive Based Models
Authors: Farabi Ehsan , Zarei‐Hanzaki Abbas , Abedi Hamid Reza
Published: September 2015

This study was conducted to develop a new method for constructing the processing maps. Using hot compression testing method at various temperature and strain rates, the experimental flow stress data were employed to build the activation energy map, strain rate sensitivity map, and finally the processing maps. In an alternative approach, the extracted constitutive models were utilized to develop the power efficiency and instability maps. It is found that the sinh‐based model would predict the unsafe regions of hot working conditions in a way more consistent with the experimental based prediction one in contrast with optimistic predictions of the Zerilli–Armstrong processing maps. All findings were further verified through examination of the obtained thermomechanically processed microstructures.
Use of CuO/MgAl2O4 and La0.8Sr0.2FeO3/γ‐Al2O3 in chemical looping reforming system for tar removal from gasification gas
Authors: Keller Martin , Leion Henrik , Mattisson Tobias
Published: September 2015

Biomass gasification gas contains condensable hydrocarbons usually referred to as “tars.” The use of chemical‐looping reforming (CLR) has been proposed as a downstream technology for tar removal. The tar removal capabilities and the regeneration properties of two particularly promising bed materials, CuO/MgAl2O4 and La0.8Sr0.2FeO3/γ‐Al2O3, were investigated using C2H4, C6H6, and C7H8 as tar surrogates. The material La0.8Sr0.2FeO3/γ‐Al2O3 exhibited high levels of conversion of all tar surrogates investigated, whereas CuO/MgAl2O4 showed less promising behavior. For this material, the C2H4 conversion in the absence of aromatic compounds was very high, but in the presence of monoaromatic compounds, the conversion of aromatics and C2H4 was poor. This indicates that monoaromatic compounds hinder the conversion of C2H4 effectively. Therefore, C2H4 may not always be a good choice as a tar surrogate and its suitability may depend on the mechanism of hydrocarbon conversion on the bed material surface in question. © 2015 American Institute of Chemical Engineers AIChE J, 62: 38–45, 2016
7q11.23 Duplication syndrome: Physical characteristics and natural history
Authors: Morris Colleen A. , Mervis Carolyn B. , Paciorkowski Alex P. , Abdul‐Rahman Omar , Dugan Sarah L. , Rope Alan F. , Bader Patricia , Hendon Laura G. , Velleman Shelley L. , Klein‐Tasman Bonita P. , Osborne Lucy R.
Published: September 2015

In order to describe the physical characteristics, medical complications, and natural history of classic 7q11.23 duplication syndrome [hereafter Dup7 (MIM 609757)], reciprocal duplication of the region deleted in Williams syndrome [hereafter WS (MIM 194050)], we systematically evaluated 53 individuals aged 1.25–21.25 years and 11 affected adult relatives identified in cascade testing. In this series, 27% of probands with Dup7 had an affected parent. Seven of the 26 de novo duplications that were examined for inversions were inverted; in all seven cases one of the parents had the common inversion polymorphism of the WS region. We documented the craniofacial features of Dup7: brachycephaly, broad forehead, straight eyebrows, broad nasal tip, low insertion of the columella, short philtrum, thin upper lip, minor ear anomalies, and facial asymmetry. Approximately 30% of newborns and 50% of older children and adults had macrocephaly. Abnormalities were noted on neurological examination in 88.7% of children, while 81.6% of MRI studies showed structural abnormalities such as decreased cerebral white matter volume, cerebellar vermis hypoplasia, and ventriculomegaly. Signs of cerebellar dysfunction were found in 62.3%, hypotonia in 58.5%, Developmental Coordination Disorder in 74.2%, and Speech Sound Disorder in 82.6%. Behavior problems included anxiety disorders, ADHD, and oppositional disorders. Medical problems included seizures, 19%; growth hormone deficiency, 9.4%; patent ductus arteriosus, 15%; aortic dilation, 46.2%; chronic constipation, 66%; and structural renal anomalies, 18%. We compare these results to the WS phenotype and offer initial recommendations for medical evaluation and surveillance of individuals who have Dup7. © 2015 Wiley Periodicals, Inc.
A microdeletion encompassing PHF21A in an individual with global developmental delay and craniofacial anomalies
Authors: Labonne Jonathan D. J. , Vogt Julie , Reali Lisa , Kong Il‐Keun , Layman Lawrence C. , Kim Hyung‐Goo
Published: September 2015

In Potocki–Shaffer syndrome (PSS), the full phenotypic spectrum is manifested when deletions are at least 2.1 Mb in size at 11p11.2. The PSS‐associated genes EXT2 and ALX4, together with PHF21A, all map to this region flanked by markers D11S1393 and D11S1319. Being proximal to EXT2 and ALX4, a 1.1 Mb region containing 12 annotated genes had been identified by deletion mapping to explain PSS phenotypes except multiple exostoses and parietal foramina. Here, we report a male patient with partial PSS phenotypes including global developmental delay, craniofacial anomalies, minor limb anomalies, and micropenis. Using microarray, qPCR, RT‐qPCR, and Western blot analyses, we refined the candidate gene region, which harbors five genes, by excluding two genes, SLC35C1 and CRY2, which resulted in a corroborating role of PHF21A in developmental delay and craniofacial anomalies. This microdeletion contains the least number of genes at 11p11.2 reported to date. Additionally, we also discuss the phenotypes observed in our patient with respect to those of published cases of microdeletions across the Potocki–Shaffer interval. © 2015 Wiley Periodicals, Inc.
New patients with Temple syndrome caused by 14q32 deletion: Genotype‐phenotype correlations and risk of thyroid cancer
Authors: Severi Giulia , Bernardini Laura , Briuglia Silvana , Bigoni Stefania , Buldrini Barbara , Magini Pamela , Dentici Maria L. , Cordelli Duccio M. , Arrigo Teresa , Franzoni Emilio , Fini Sergio , Italyankina Eleonora , Loddo Italia , Novelli Antonio , Graziano Claudio
Published: September 2015

Temple syndrome (TS) is caused by abnormal expression of genes at the imprinted locus 14q32. A subset of TS patients carry 14q32 deletions of paternal origin. We aimed to define possible genotype‐phenotype correlations and to highlight the prevalence of thyroid dysfunction, which is a previously unreported feature of TS. We described four new patients who carry deletions of paternal origin at 14q32 detected by array‐CGH and reviewed nine patients reported in the medical literature. We compared clinical features with respect to deletion size and position. Expression of DLK1 is altered in all the patients with TS, but intellectual disability (ID) is present only in patients with larger deletions extending proximally to the imprinted locus. This study led to the identification of an ID “critical region” containing four annotated genes including YY1 as the strongest candidate. Furthermore, we described three patients with thyroid dysfunction, which progressed to papillary carcinoma at a very young age in two of them. We conclude that DLK1 loss of function is likely to be responsible for the core features of TS, while haploinsufficiency of a gene outside the imprinted region causes ID. Thyroid cancer may be an unrecognized feature and monitoring for thyroid dysfunction should thus be considered in TS patients. © 2015 Wiley Periodicals, Inc.