MCS+ : An Efficient Algorithm for Crawling the Community Structure in Multiplex Networks

In this article, we consider the problem of crawling a multiplex network to identify the community structure of a layer-of-interest. A multiplex network is one where there are multiple types of relationships between the nodes. In many multiplex networks, some layers might be easier to explore (in terms of time, money etc.). We propose MCS+ , an algorithm that can use the information from the easier to explore layers to help in the exploration of a layer-of-interest that is expensive to explore. We consider the goal of exploration to be generating a sample that is representative of the communities in the complete layer-of-interest. This work has practical applications in areas such as exploration of dark (e.g., criminal) networks, online social networks, biological networks, and so on. For example, in a terrorist network, relationships such as phone records, e-mail records, and so on are easier to collect; in contrast, data on the face-to-face communications are much harder to collect, but also potentially more valuable. We perform extensive experimental evaluations on real-world networks, and we observe that MCS+ consistently outperforms the best baseline—the similarity of the sample that MCS+ generates to the real network is up to three times that of the best baseline in some networks. We also perform theoretical and experimental evaluations on the scalability of MCS+ to network properties, and find that it scales well with the budget, number of layers in the multiplex network, and the average degree in the original network.

Initial atomic-scale oxidation pathways on a Ni–15Cr(100) alloy surface

To understand the atomistic phenomenon behind initial oxidation processes, we have studied the nanoscale evolution of oxide growth prior to the formation of a complete layer on a Ni–15 wt%Cr(100) alloy surface using scanning tunneling microscopy/spectroscopy (STM/STS). At the onset of oxidation, a NiO superlattice forms oxide wedges across the step edges, eventually growing across the terraces. The completion of the NiO layer is followed by nucleation of the next layer, which always commences at the groove site of the superlattice. The Cr-oxide formation initiates as disk-shaped oxide particles early in the oxidation process, which Monte Carlo simulations reveal are likely caused by Cr clustering across the alloy surface. Upon further oxidation, a Cr(100)-p(2 × 2)O reconstructed surface is observed, indicating phase separation of Cr predicates the formation of the passive Cr-oxide film. The STS results vary across the oxide–alloy interface and between each oxide, providing greater insight into the origins of electronic heterogeneity and their effect on oxide growth. Using these data, we propose an oxidation model that highlights the growth of partial oxide layers on Ni–Cr(100) alloys within the pre-Cabrera–Mott regime.

Molybdenum Trioxide on Anatase TiO2(101) - Formation of Monodispersed (MoO3)1 Monomers from Oligomeric (MoO3)n Clusters

<p>Complex oxide systems with hierarchical order are of critical importance in material science and catalysis. Despite their immense potential, their design and synthesis are rather difficult. In this study we demonstrate how the deposition of small oligomeric (MoO₃)_1-6 clusters, which can be formed by the sublimation of MoO₃ powders, leads to the formation of locally ordered layers of (MoO₃)₁ monomers on anatase TiO₂(101). Using both high-resolution imaging and theoretical calculations, we show that at room temperature, such oligomers undergo spontaneous dissociation to their monomeric units. In initial stages of the deposition, this is reflected by the observation of one to six neighboring (MoO₃)₁ monomers that parallel the size distribution of the oligomers. A transient mobility of such oligomers on both bare TiO₂(101) and (MoO₃)₁ covered areas is key to the formation of a complete layer with a saturation coverage of one (MoO₃)₁ per two undercoordinated surface Ti sites. We further show that such layers are stable to 500 K, making them highly suitable for a broad range of applications. </p>

Molybdenum Trioxide on Anatase TiO2(101) - Formation of Monodispersed (MoO3)1 Monomers from Oligomeric (MoO3)n Clusters

<p>Complex oxide systems with hierarchical order are of critical importance in material science and catalysis. Despite their immense potential, their design and synthesis are rather difficult. In this study we demonstrate how the deposition of small oligomeric (MoO₃)_1-6 clusters, which can be formed by the sublimation of MoO₃ powders, leads to the formation of locally ordered layers of (MoO₃)₁ monomers on anatase TiO₂(101). Using both high-resolution imaging and theoretical calculations, we show that at room temperature, such oligomers undergo spontaneous dissociation to their monomeric units. In initial stages of the deposition, this is reflected by the observation of one to six neighboring (MoO₃)₁ monomers that parallel the size distribution of the oligomers. A transient mobility of such oligomers on both bare TiO₂(101) and (MoO₃)₁ covered areas is key to the formation of a complete layer with a saturation coverage of one (MoO₃)₁ per two undercoordinated surface Ti sites. We further show that such layers are stable to 500 K, making them highly suitable for a broad range of applications. </p>

Molybdenum Trioxide on Anatase TiO2(101) - Formation of Monodispersed (MoO3)1 Monomers from Oligomeric (MoO3)n Clusters

<p>Complex oxide systems with hierarchical order are of critical importance in material science and catalysis. Despite their immense potential, their design and synthesis are rather difficult. In this study we demonstrate how the deposition of small oligomeric (MoO₃)_1-6 clusters, which can be formed by the sublimation of MoO₃ powders, leads to the formation of locally ordered layers of (MoO₃)₁ monomers on anatase TiO₂(101). Using both high-resolution imaging and theoretical calculations, we show that at room temperature, such oligomers undergo spontaneous dissociation to their monomeric units. In initial stages of the deposition, this is reflected by the observation of one to six neighboring (MoO₃)₁ monomers that parallel the size distribution of the oligomers. A transient mobility of such oligomers on both bare TiO₂(101) and (MoO₃)₁ covered areas is key to the formation of a complete layer with a saturation coverage of one (MoO₃)₁ per two undercoordinated surface Ti sites. We further show that such layers are stable to 500 K, making them highly suitable for a broad range of applications. </p>

Étude du comportement alimentaire de la pintade locale (Numida meleagris, L.) à l’Ouest du Burkina-Faso

Les asticots représentent une alternative pour faire face à l’inaccessibilité des intrants sources de protéine en aviculture. L’objectif de cette étude est d’analyser le comportement alimentaire des pintades locales en présence d’asticots séchés et d’autres aliments servis en mode d’assiette anglaise ou cafeteria. Douze pintades adultes ont été individuellement réparties dans un dispositif bloc complètement randomisé à trois traitements (08 h, 12 h et 16 h) et en quatre répétitions. Deux expériences successives ont été conduites. Au cours de la première, les asticots séchés ont été associés aux grains de sorgho et de maïs concassés et servis aux pintades. Pendant la deuxième, un aliment complet a remplacé le maïs. Chaque service de durée 30 min a été suivi d’une distribution de l’aliment complet en deux temps : 01 h 30 min après et pendant la claustration (de 19 h à 07 h 30 min). La consommation journalière individuelle et la proportion de chaque aliment dans la ration ont été déterminées. Les résultats ont montré que les oiseaux préfèrent plus les grains de céréales (entre 95,56% et 98,13%) que les asticots séchés (moins de 5%) servis concurrentiellement avec les céréales. D’autres investigations sont nécessaires pour promouvoir l’utilisation des asticots dans l’aviculture. © 2020 International Formulae Group. All rights reserved. Mots clés: Aviculture traditionnelle, nutrition aviaire, asticots, Bobo Dioulasso English Title: Feeding behaviour of local guinea fowl (Numida meleagris, L.) in western Burkina Faso English Abstract Maggots represent an alternative to deal with the inaccessibility of protein source inputs in poultry farming. The study aimed at analyzing the feeding behaviour of local guinea fowl which received dried maggots and other feeds in cafeteria feeding. Twelve adult guinea fowls were assigned individually in a completely randomized block design with three treatments (08 am, 12 am and 04 pm) and four replications per treatment. Two consecutive experiments were carried out. In the first experiment, dried maggots were choice-fed with sorghum and cracked maize grain and served to guinea fowl. In the second experiment, a complete layer diet replaced the cracked maize. In all treatments, the cafeteria test lasted 30 minutes, followed by a two-step distribution of the complete diet: 01 h 30 min after and during the confinement at night (from 07 pm to 07:30 am). The daily individual consumption and the proportion of each food in the ration were determined. The results showed that birds prefer cereal grains (between 95.56% and 98.13%) more than dried maggots (less than 5%) served concurrently with cereals. Further investigations are needed to promote the use of maggots in poultry farming. © 2020 International Formulae Group. All rights reserved. Keywords: Traditional poultry farming, avian nutrition, maggots, Bobo-Dioulasso

Preparation of γ-Ce2S3@ZrO2 Red Pigment by Hydrolysis Combined Hydrothermal Two Steps Method

The core-shell red pigment γ-Ce2S3@ZrO2 was prepared by a two step method. γ-Ce2S3 was pre-coated at 30°C with hydrolysis, followed by hydrothermal reaction at 180 °C for further coating and crystallization. The effect of preparation method, hydrolysis dropping speed and the number of hydrothermal process on the microstructure of the ZrO2 layer was observed. The influence of coating layer to chromaticity, heat resistance and acid stability was also investigated. The results show that a complete layer at nearly 90 nm coated on the surface of the γ-Ce2S3 particles. The as-prepared pigment exhibited pure red color (L* = 44.38, a* = 31.94, b* = 23.14). Moreover, this coating layer can provide protection to pigment particles. The core-shell pigment can remain red color (L* = 42.71, a* = 26.23, b* =18.38) after calcined in air at 380 °C, while uncoated pigment turned to grey dark at 360 oC.

Crystal chemistry of natural layered double hydroxides: 4. Crystal structures and evolution of structural complexity of quintinite polytypes from the Kovdor alkaline-ultrabasic massif, Kola peninsula, Russia

Two quintinite polytypes, 3R and 2T, which are new for the Kovdor alkaline-ultrabasic complex, have been structurally characterized. The crystal structure of quintinite-2T was solved by direct methods and refined to R1 = 0.048 on the basis of 330 unique reflections. The structure is trigonal, P$\bar 3$c1, a = 5.2720(6), c = 15.113(3) Å and V = 363.76(8) Å3. The crystal structure consists of [Mg2Al(OH)6]+ brucite-type layers with an ordered distribution of Mg2+ and Al3+ cations according to the $\sqrt 3 $ × $\sqrt 3 $ superstructure with the layers stacked according to a hexagonal type. The complete layer stacking sequence can be described as …=Ab1C = Cb1A=…. The crystal structure of quintinite-3R was solved by direct methods and refined to R1 = 0.022 on the basis of 140 unique reflections. It is trigonal, R$\bar 3$m, a = 3.063(1), c = 22.674(9) Å and V = 184.2(1) Å3. The crystal structure is based upon double hydroxide layers [M2+,3+(OH)2] with disordered distribution of Mg, Al and Fe and with the layers stacked according to a rhombohedral type. The stacking sequence of layers can be expressed as …=АB = BC = CA=… The study of morphologically different quintinite generations grown on one another detected the following natural sequence of polytype formation: 2H → 2T → 1M that can be attributed to a decrease of temperature during crystallization. According to the information-based approach to structural complexity, this sequence corresponds to the increasing structural information per atom (IG): 1.522 → 1.706 → 2.440 bits, respectively. As the IG value contributes negatively to the configurational entropy of crystalline solids, the evolution of polytypic modifications during crystallization corresponds to the decreasing configurational entropy. This is in agreement with the general principle that decreasing temperature corresponds to the appearance of more complex structures.

The structure of the perivascular compartment in the old canine brain: a case study

Dilatation of periarteriolar spaces in MRI of the ageing human brains occurs in white matter (WM), basal ganglia and midbrain but not in cerebral cortex. Perivenous collagenous occurs in periventricular but not in subcortical WM. Here we test the hypotheses that (a) the capacity for dilatation of periarteriolar spaces correlates with the anatomical distribution of leptomeningeal cells coating intracerebral arteries and (b) the regional development of perivenous collagenous in the WM correlates with the population of intramural cells in the walls of veins. The anatomical distribution of leptomeningeal and intramural cells related to cerebral blood vessels is best documented by electron microscopy, requiring perfusion-fixed tissue not available in human material. We therefore analysed perfusion-fixed brain from a 12-year-old Beagle dog as the canine brain represents the anatomical arrangement in the human brain. Results showed regional variation in the arrangement of leptomeningeal cells around blood vessels. Arterioles are enveloped by one complete layer of leptomeninges often with a second incomplete layer in the WM. Venules showed incomplete layers of leptomeningeal cells. Intramural cell expression was higher in the post-capillary venules of the subcortical WM when compared with periventricular WM, suggesting that periventricular collagenosis around venules may be due to a lower resistance in the venular walls. It appears that the regional variation in the capacity for dilatation of arteriolar perivascular spaces in the white WM may be related to the number of perivascular leptomeningeal cells surrounding vessels in different areas of the brain.

Structural Study of the Innovative 3C-SiC/Si/3C-SiC/Si Heterostructure for Electro-Mechanical Applications

In this work, we report the growth of a 3C-SiC layer oriented along the [111] direction on Si (110)/3C-SiC(001)/Si (001) heterostructure. The growth of the complete layer stack occurs in one deposition run in a Chemical Vapor Deposition (CVD) reactor on on-axis Si (001) substrate. The structural properties of the 3CSiC(111) layer are discussed and the impact of the first 3C-SiC layer on the subsequent growth is highlighted. The 3C-SiC(111) top layer shows two domains rotated by 90o around the growth direction directly linked to the domains rotation in the Si epilayer underneath it. Furthermore, μtwins and stacking faults are present on the inclined (111) planes in the 3C-SiC epilayer.