Exploring universal patterns in human home-work commuting from mobile phone data

Home-work commuting has always attracted significant research attention because of its impact on human mobility. One of the key assumptions in this domain of study is the universal uniformity of commute times. However, a true comparison of commute patterns has often been hindered by the intrinsic differences in data collection methods, which make observation from different countries potentially biased and unreliable. In the present work, we approach this problem through the use of mobile phone call detail records (CDRs), which offers a consistent method for investigating mobility patterns in wholly different parts of the world. We apply our analysis to a broad range of datasets, at both the country and city scale. Additionally, we compare these results with those obtained from vehicle GPS traces in Milan. While different regions have some unique commute time characteristics, we show that the home-work time distributions and average values within a single region are indeed largely independent of commute distance or country (Portugal, Ivory Coast, and Boston)--despite substantial spatial and infrastructural differences. Furthermore, a comparative analysis demonstrates that such distance-independence holds true only if we consider multimodal commute behaviors--as consistent with previous studies. In car-only (Milan GPS traces) and car-heavy (Saudi Arabia) commute datasets, we see that commute time is indeed influenced by commute distance

Cosmogenic activation of Germanium and its reduction for low background experiments

Production of $^{60}$Co and $^{68}$Ge from stable isotopes of Germanium by nuclear active component of cosmic rays is a principal background source for a new generation of $^{76}$Ge double beta decay experiments like GERDA and Majorana. The biggest amount of cosmogenic activity is expected to be produced during transportation of either enriched material or already grown crystal. In this letter properties and feasibility of a movable iron shield are discussed. Activation reduction factor of about 10 is predicted by simulations with SHIELD code for a simple cylindrical configuration. It is sufficient for GERDA Phase II background requirements. Possibility of further increase of reduction factor and physical limitations are considered. Importance of activation reduction during Germanium purification and detector manufacturing is emphasized.Comment: 10 pages, 3 tables, 6 figure

Different Sites of Alcohol Action in the NMDA Receptor GluN2A and GluN2B Subunits

The NMDA receptor is a major target of alcohol action in the CNS, and recent behavioral and cellular studies have pointed to the importance of the GluN2B subunit in alcohol action. We and others have previously characterized four amino acid positions in the third and fourth membrane-associated (M) domains of the NMDA receptor GluN2A subunit that influence both ion channel gating and alcohol sensitivity. In this study, we found that substitution mutations at two of the four corresponding positions in the GluN2B subunit, F637 and G826, influence ethanol sensitivity and ion channel gating. Because position 826 contains a glycine residue in the native protein, we focused our attention on GluN2B(F637). Substitution mutations at GluN2B(F637) significantly altered ethanol IC50 values, glutamate EC50 values for peak (Ip) and steady-state (Iss) current, and steady-state to peak current ratios (Iss:Ip). Changes in apparent glutamate affinity were not due to agonist trapping in desensitized states, as glutamate Iss EC50 values were not correlated with Iss:Ip values. Ethanol sensitivity was correlated with values of both Ip and Iss glutamate EC50, but not with Iss:Ip. Values of ethanol IC50, glutamate EC50, and Iss:Ip for mutants at GluN2B(F637) were highly correlated with the corresponding values for mutants at GluN2A(F636), consistent with similar functional roles of this position in both subunits. These results demonstrate that GluN2B(Phe637) regulates ethanol action and ion channel function of NMDA receptors. However, despite highly conserved M domain sequences, ethanol\u27s actions on GluN2A and GluN2B subunits differ

Structure of 311 service requests as a signature of urban location

© 2017 Wang et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. While urban systems demonstrate high spatial heterogeneity, many urban planning, economic and political decisions heavily rely on a deep understanding of local neighborhood contexts. We show that the structure of 311 Service Requests enables one possible way of building a unique signature of the local urban context, thus being able to serve as a low-cost decision support tool for urban stakeholders. Considering examples of New York City, Boston and Chicago, we demonstrate how 311 Service Requests recorded and categorized by type in each neighborhood can be utilized to generate a meaningful classification of locations across the city, based on distinctive socioeconomic profiles. Moreover, the 311-based classification of urban neighborhoods can present sufficient information to model various socioeconomic features. Finally, we show that these characteristics are capable of predicting future trends in comparative local real estate prices. We demonstrate 311 Service Requests data can be used to monitor and predict socioeconomic performance of urban neighborhoods, allowing urban stakeholders to quantify the impacts of their interventions

Block of NMDA receptor channels by endogenous neurosteroids: implications for the agonist induced conformational states of the channel vestibule

N-methyl-D-aspartate receptors (NMDARs) mediate synaptic plasticity, and their dysfunction is implicated in multiple brain disorders. NMDARs can be allosterically modulated by numerous compounds, including endogenous neurosteroid pregnanolone sulfate. Here, we identify the molecular basis of the use-dependent and voltage-independent inhibitory effect of neurosteroids on NMDAR responses. The site of action is located at the extracellular vestibule of the receptor's ion channel pore and is accessible after receptor activation. Mutations in the extracellular vestibule in the SYTANLAAF motif disrupt the inhibitory effect of negatively charged steroids. In contrast, positively charged steroids inhibit mutated NMDAR responses in a voltage-dependent manner. These results, in combination with molecular modeling, characterize structure details of the open configuration of the NMDAR channel. Our results provide a unique opportunity for the development of new therapeutic neurosteroid-based ligands to treat diseases associated with dysfunction of the glutamate system

ПАРАМЕТРИЗОВАННЫЙ ТАЙЛИНГ: ОПРЕДЕЛЕНИЕ ГРАНИЦ ЛОКАЛЬНЫХ ЦИКЛОВ В НЕПОЛНЫХ ТАЙЛАХ

The aspects of parameterized tiling in application to algorithms with index domain represented by a convex polyhedron are investigated. The structure of the set of partial tiles is proposed and the formulas to determine this set are constructed. The formula to define the boundaries of local loops in partial tiles is obtained as well. These formulas enable one to minimize the calculation time of local loop boundaries in the implementation of the tiling in sequential and parallel programs. Исследованы аспекты применения параметризованного тайлинга к алгоритмам, область вычисления которых представима выпуклым многогранником. Предложена структура множества неполных тайлов, построены формулы для определения этого множества. Также получены формулы, определяющие границы изменения локальных циклов в неполных тайлах. Эти формулы позволяют минимизировать время расчета границ локальных циклов при реализации тайлинга в последовательных и параллельных программах.

ДВУХУРОВНЕВЫЙ ТАЙЛИНГ И ЕГО ПРИМЕНЕНИЕ ПРИ ПРОСТРАНСТВЕННО-ВРЕМЕННОМ ОТОБРАЖЕНИИ АЛГОРИТМОВ НА ПАРАЛЛЕЛЬНЫЕ АРХИТЕКТУРЫ

The idea of application of two-level tiling at space-time mapping of algorithms onto parallel computing systems is proposed. A formalized method of parameterized two-level tiling is developed. The formulas for determination of global dependences between different-level tiles are constructed. The formal representation of sets of iterations generating these dependences is obtained. The representation is given in the form of polyhedra with an explicit expression of their boundaries. A formalized method of space-time mapping onto supercomputers is developed. The method is based on the locally parallel globally sequential mapping strategy and the designed method of two-level tiling. The method realizes the proposed idea of space-time mapping in integration with tiling. Предложена идея использования двухуровневого тайлинга для решения задачи пространственно-временного отображения алгоритмов на параллельные вычислительные системы заданной размерности и размера. Разработан формализованный метод параметризованного двухуровневого тайлинга. Получены формулы для определения векторов глобальных зависимостей между тайлами первого и второго уровней, а также формальное представление множеств итераций, порождающих эти зависимости, в виде многогранников с явным выражением их границ. На основе разработанного метода двухуровневого тайлинга и локально параллельной глобально последовательной cтратегии отображения предложен формализованный метод решения задачи пространственно-временного отображения алгоритмов в интеграции с тайлингом.

Плотные покрытия области вычислений гексагональными тайлами

The hexagonal tiling in application to algorithms with a two-dimensional computational domain is investigated. A formal definition of a parametrized hexagonal tiling is proposed. Necessary and sufficient conditions for a dense coverage of the computational domain by hexagonal tiles are obtained.Communicated by Corresponding Member Leonid A. YanovichИсследованы аспекты применения гексагонального тайлинга к алгоритмам с двумерной областью вычислений. Предложено формальное определение параметризованного гексагонального тайлинга. Получены необходимые и достаточные условия плотного покрытия области вычислений гексагональными тайлами.Представлено членом-корреспондентом Л. А. Яновиче