bluuebunny/crossref_metadata_2025 huggingface dataset:
Performance of RGM Medium for Isolation of Nontuberculous Mycobacteria from Respiratory Specimens from Non-Cystic Fibrosis Patients
Authors: Rotcheewaphan Suwatchareeporn , Odusanya Oluwadamilola E. , Henderson Christina M. , Stephenson Dominic , Olivier Kenneth N. , Perry John D. , Zelazny Adrian M.
Published: November 2018

A new selective medium for rapidly growing mycobacteria (RGM medium) was evaluated on respiratory specimens from non-cystic fibrosis patients and compared to the mycobacterial growth indicator tube (MGIT) system and Middlebrook 7H11 agar for the isolation of all nontuberculous mycobacteria (NTM). A total of 203 mucolyzed respiratory specimens collected from 163 patients were inoculated on RGM medium and incubated at both 30°C (RGM30) and 35°C (RGM35) over a 28-day period.
Closing and Opening Holes in the Glycan Shield of HIV-1 Envelope Glycoprotein SOSIP Trimers Can Redirect the Neutralizing Antibody Response to the Newly Unmasked Epitopes
Authors: Ringe Rajesh P. , Pugach Pavel , Cottrell Christopher A. , LaBranche Celia C. , Seabright Gemma E. , Ketas Thomas J. , Ozorowski Gabriel , Kumar Sonu , Schorcht Anna , van Gils Marit J. , Crispin Max , Montefiori David C. , Wilson Ian A. , Ward Andrew B. , Sanders Rogier W. , Klasse P. J. , Moore John P.
Published: November 2018

Engineered SOSIP trimers mimic envelope-glycoprotein spikes, which stud the surface of HIV-1 particles and mediate viral entry into cells. When used for immunizing test animals, they elicit antibodies that neutralize resistant sequence-matched HIV-1 isolates. These neutralizing antibodies recognize epitopes in holes in the glycan shield that covers the trimer. Here, we added glycans to block the most immunogenic neutralization epitopes on BG505 and B41 SOSIP trimers. In addition, we removed selected other glycans to open new holes that might expose new immunogenic epitopes. We immunized rabbits with the various glycan-modified trimers and then dissected the specificities of the antibody responses. Thus, in principle, the antibody response might be diverted from one site to a more cross-reactive one, which would help in the induction of broadly neutralizing antibodies by HIV-1 vaccines based on envelope glycoproteins.
Restriction of Human Cytomegalovirus Infection by Galectin-9
Authors: Machala Emily A. , Avdic Selmir , Stern Lauren , Zajonc Dirk M. , Benedict Chris A. , Blyth Emily , Gottlieb David J. , Abendroth Allison , McSharry Brian P. , Slobedman Barry
Published: November 2018

Human cytomegalovirus (HCMV) continues to cause serious and often life-threatening disease in those with impaired or underdeveloped immune systems. This virus is able to infect and replicate in a wide range of human cell types, which enables the virus to spread to other individuals in a number of settings. Current antiviral drugs are associated with a significant toxicity profile, and there is no vaccine; these factors highlight a need to identify additional targets for the development of anti-HCMV therapies. We demonstrate for the first time that secretion of a member of the galectin family of proteins, galectin-9 (Gal-9), is upregulated during natural HCMV-reactivated infection and that this soluble cellular protein possesses a potent capacity to block HCMV infection by inhibiting virus entry into the host cell. Our findings support the possibility of harnessing the antiviral properties of Gal-9 to prevent HCMV infection and disease.
Identification and Functional Characterization of a Novel Fc Gamma-Binding Glycoprotein in Rhesus Cytomegalovirus
Authors: Kolb Philipp , Sijmons Steven , McArdle Matthew R. , Taher Husam , Womack Jennie , Hughes Colette , Ventura Abigail , Jarvis Michael A. , Stahl-Hennig Christiane , Hansen Scott , Picker Louis J. , Malouli Daniel , Hengel Hartmut , Früh Klaus
Published: November 2018

Rhesus cytomegalovirus (RhCMV) offers a unique model for studying human cytomegalovirus (HCMV) pathogenesis and vaccine development. RhCMV infection of nonhuman primates greatly broadened the understanding of mechanisms by which CMVs evade or reprogram T cell and natural killer cell responses
in vivo
. However, the role of humoral immunity and viral modulation of anti-CMV antibodies has not been studied in this model. There is evidence from
in vitro
studies that HCMVs can evade humoral immunity. By gene mapping and with the help of a novel cell-based reporter assay system we characterized the first RhCMV encoded IgG-Fcγ binding glycoprotein as a potent antagonist of rhesus FcγR activation. We further demonstrate that, unlike evasion of T cell immunity, this viral Fcγ receptor is not required to overcome anti-CMV immunity to establish secondary infections. These findings enable more detailed studies of the
in vivo
consequences of CMV evasion from IgG responses in nonhuman primate models.
Whole-Genome Sequence of a Brucella melitensis Strain Isolated from Sheep in Saudi Arabia
Authors: Alghoribi Majed F. , Zidan Kamal H. , Alswaji Abdulrahman A. , Alhafufi Ali N. , Ahmed Abdalla , Balkhy Hanan H.
Published: November 2018

The intracellular Gram-negative bacterium
Brucella melitensis
causes a zoonotic disease in humans originating from animals. Here, we report the whole-genome sequence (WGS) of
Brucella melitensis
strain KSA_BM_07, isolated from sheep in March 2017 in Huraymila, Kingdom of Saudi Arabia.
Complete Closed Genome Sequences of Three Salmonella enterica subsp. enterica Serovar Dublin Strains Isolated from Cattle at Harvest
Authors: Harhay Dayna M. , Smith Timothy P. L. , Harhay Gregory P. , Loneragan Guy H. , Webb Hattie E. , Bugarel Marie , Haley Bradd J. , Kim Seon Woo , Van Kessel Jo Ann S.
Published: November 2018

Salmonella enterica
subsp.
enterica
serovar Dublin is a host-adapted pathogen for cattle that can cause invasive disease in humans.
Genome Sequence of
Prosthecochloris
sp. Strain ZM and
Prosthecochloris
sp. Strain ZM-2, Isolated from an Arctic Meromictic Lake
Authors: Grouzdev Denis S. , Gaisin Vasil A. , Krutkina Maria S. , Bryantseva Irina A. , Lunina Olga N. , Savvichev Alexander S. , Gorlenko Vladimir M.
Published: November 2018

Draft genome sequences of green-colored and brown-colored green sulfur bacteria (GSB),
Prosthecochloris
sp. ZM and
Prosthecochloris
sp.
Ambulances under siege in Syria
Authors: Wong C Hayes , Chen Christine Yen-Ting
Published: November 2018

Background

Healthcare is under attack in Syria with repeated air strikes on hospitals and ambulances and the largest death toll of health workers in any recorded conflict.1 Ambulances in Syria have been bombed, shot at, stolen, looted and obstructed, significantly impeding their ability to safely evacuate the wounded and provide medical aid.

Methods

This article presents the summary of a literature review on attacks against ambulances in Syria from 2011 to 2018, as well as a descriptive secondary data analysis on individual attacks reported by the Syrian Network for Human Rights from January 2016 to December 2017. A peer-reviewed literature search included three databases (PubMed, ProQuest and Embase), and a grey literature search included reports from groups involved in the Syrian health response or human rights monitoring.

Findings

From 2016 to 2017, there were 204 individual attacks involving 243 ambulances. Half (49%) were either heavily damaged or put out of service. The main perpetrators were the Syrian regime (60%) and the Russian armed forces (29%). Half (52%) of ambulances were directly targeted. The peer-reviewed literature search yielded 18 articles, from which the following themes were drawn: targeting of ambulances, ‘double-tap’ attacks, delays to care, obstruction and other forms of violence, and long-term consequences.

Interpretation

Ambulances have been intentionally and repeatedly targeted throughout the Syrian conflict as part of a war strategy. Real challenges in monitoring and systematically tracking attacks on ambulances exist, but as a result, they are understudied and likely under-reported.
Pregnancy-associated plasma protein-a is associated with subclinical atherosclerosis in men with HIV infection
Authors: Yildiz Suleyman Sezai , Cetin Sukru , Keskin Kudret , Gunduz Alper , Cetinkal Gokhan , Bulbun Goncagul , Sigirci Serhat , Pilten Saadet , Kilickesmez Kadriye Orta
Published: November 2018

The pathophysiology of an early and accelerated atherosclerotic process is complex and multifactorial in HIV-infected men compared with HIV-non-infected men. Several biomarkers have been well studied in the detection of the early stage of atherosclerosis, but studies are limited in HIV-infected men. The objective of this study was to investigate the association between serum pregnancy-associated plasma protein-A (PAPP-A) and carotid intima-media wall thickness (CIMT) in asymptomatic HIV-infected men. This a case–control study group comprising 118 HIV-infected men and 60 age-matched and gender-matched HIV-non-infected men. Serum PAPP-A was measured using an ELISA kit and carotid IMT was evaluated by Doppler ultrasonography in all subjects. Statistical analysis included receiver-operating characteristic (ROC) analysis, Pearson correlation and logistic regression analysis. Serum PAPP-A level was significantly higher in HIV +CIMT+ group compared with HIV +CIMT group and HIV–CIMT- group. We found a positive correlation between PAPP-A and increased CIMT (r=0.737, p<0.0001), and a negative correlation between nadir CD4 T cell counts and increased CIMT (r=−0.526, p<0.001). In multivariate logistic regression analyses, PAPP-A, nadir CD4 T cell count and age were significantly associated with subclinical atherosclerosis (p<0.001, p=0.006 and p=0.032, respectively). In ROC analysis, PAPP-A levels of >3.70 µg/mL were associated with subclinical atherosclerosis in HIV+ men with a specificity of 100% and a sensitivity of 71% (area under the curve: 0.949, 95% CI 0.875 to 1.000, p<0.001). Serum PAPP-A level was strongly correlated with increased CIMT in HIV-infected men. PAPP-A might be used as an early biomarker to identify atherosclerosis in asymptomatic HIV-infected men.
The Bathurst Mining Camp, New Brunswick: data integration, geophysical modelling, and implications for exploration
Authors: Ugalde Hernan , Morris William A. , van Staal Cees
Published: November 2018

The Bathurst Mining Camp (BMC) is one of Canada’s oldest mining districts for volcanogenic massive sulphide (VMS) deposits. Most of the 46 known deposits were discovered in the 1950s using a combination of geological and geophysical methods. However, renewed exploration efforts over the past 15 years have not been as successful as one would expect given the level of expenditure of the camp. Nevertheless, this has created a large database of high resolution airborne geophysical data (magnetics, electromagnetics, radiometrics, and full tensor gravity gradiometry) which makes Bathurst a unique case. We show data compilation and map view interpretation, followed by two-and-a-half-dimensional (2.5D) gravity and magnetic modelling. From this, we provide constraints on the folded structure of the mafic and felsic volcanic units, and we interpret a large gravity anomaly in the southeast as a possible ophiolite or a dense thick package of basaltic rocks. Finally, we show an example of 3D modelling in the northwestern part of the camp, where we combine map view interpretation with section-based modelling and 3D geophysical inversion.
Origin and 87Rb–87Sr age of porewaters in low permeability Ordovician sediments on the eastern flank of the Michigan Basin, Tiverton, Ontario, Canada
Authors: Bouchard Laurianne , Veizer Ján , Kennell-Morrison Laura , Jensen Mark , Raven Ken G. , Clark Ian D.
Published: November 2018

Porewater extractions and acid leachates of rock core from a 250 m thick sequence of low-permeability Ordovician-age shales and limestones, on the eastern flank of the Michigan Basin, were analysed for strontium isotope ratios in an attempt to infer porewater ages from observed 87Sr/86Sr enrichments. The porewaters originated as Ordovician seawater, which subsequently mixed with evaporated Silurian seawater infiltrating from above, and, to some extent, with a deep brine—with an enriched 87Sr/86Sr signature—from the underlying crystalline shield or deep basin. The porewater 87Sr/86Sr ratios are more radiogenic than contemporaneous seawater but show no obvious correlation to those leached from the solid rock phases. Accepting that the initial 87Sr/86Sr signatures in porewaters were dominated by Late Silurian brine, potentially with an additional deep brine component, the excess of radiogenic 87Sr appears to represent ingrowth from 87Rb decay over a time span of some 420 million years, approaching the depositional age of the rocks. Similarly, Rb/Sr errochron ages of acid leachates of solid phases, and the calculated initial 87Sr/86Sr isotopic ratios, are consistent with a proposition that the calcites inherited their Sr from Ordovician seawater and were dolomitized shortly afterwards by infiltrating Mg-enriched evaporative brine, indicating long-term conservative behaviour for the enclosing carbonate rocks. The errochron for leachates from (alumino)silicates yields a high initial 87Sr/86Sr, but with an errochron age of about 340 ± 48 Ma, likely owing to variable admixtures of diagenetic illite in the shales. Overall, the data provide evidence for a stable hydrologic regime since Paleozoic time.
Deep mineral exploration using multi-scale electromagnetic geophysics: the Lalor massive sulphide deposit case study
Authors: Yang Dikun , Fournier Dominique , Kang Seogi , Oldenburg Douglas W.
Published: November 2018

The Lalor deposit in Snow Lake, central Manitoba, is one of the most significant mineral discoveries in Canada in the past decade. Buried 600 m below the surface, the deposit remained undiscovered until a deep penetrating geophysical electromagnetic (EM) system was employed. Since then, the deposit has been a test site for many modern geophysical systems. This paper presents a comparative study of four EM data sets acquired at Lalor. We image the electrical conductivity structure of the subsurface by carrying out independent 3-D inversions of the data. The four data sets are acquired through airborne, surface, and borehole systems, including airborne natural source EM (ZTEM), airborne time-domain EM (HELITEM), surface large loop EM (SQUID), and borehole EM (PULSE-EM). ZTEM has good depth of penetration, but its inversion model may be biased if the background model is not properly chosen. The HELITEM system can complement ZTEM by validating the actual conductivity of the deposit. With the information provided by airborne surveys, surface EM can better define the geometry of the ore body at a local scale and help in defining drilling targets. Once boreholes are drilled, sensors can be sent downhole, possibly probing the ore lenses that are interbedded at a greater depth. Our 3-D imaging experiments demonstrate that modern geophysical technology is capable of making deep exploration and assisting a more informed process throughout the entire workflow from reconnaissance to drilling and development.
Oxymatrine attenuates amyloid beta 42 (Aβ1–42)-induced neurotoxicity in primary neuronal cells and memory impairment in rats
Authors: Dong Peiliang , Ji Xiaomeng , Han Wei , Han Hua
Published: November 2018

Amyloid beta 42 (Aβ1–42)-induced oxidative stress causes the death of neuronal cells and is involved in the development of Alzheimer’s disease. Oxymatrine (OMT) inhibits oxidative stress. In this study, we investigated the effect of OMT on Aβ1–42-induced neurotoxicity in vivo and in vitro. In the Morris water maze test, OMT significantly decreased escape latency and increased the number of platform crossings. In vitro, OMT markedly increased cell viability and superoxide dismutase activity. Moreover, OMT decreased lactate dehydrogenase leakage, malondialdehyde content, and reactive oxygen species in a dose-dependent manner. OMT upregulated the ratio of Bcl-2/Bax and downregulated the level of caspase-3. Furthermore, OMT inhibited the activation of MAP kinase (ERK 1/2, JNK) and nuclear factor κB. In summary, OMT may potentially be used in the treatment of Alzheimer’s disease.
Cloud removal based on dual tree complex wavelet transformation and improved atmosphere transmission
Authors: Wu Feng , Zhu Xifang , Xiang Ruxi , Xu Qingquan , Wen Juxiang , Liu Peng
Published: November 2018

Clouds produce obstacles which hinder satellites from collecting clear ground information. Removing clouds from satellite images becomes a promising way to recover valuable information efficiently. It reduces the demands for weather and improves the image collecting flexibility. In this paper, a cloud removal algorithm from single images is studied. Firstly, the fundamental principle of the dual tree complex wavelet transformation (DTCWT) is introduced briefly. The scheme of dividing the clouds from the scenery and the background roughly according to their frequencies after the image is decomposed by DTCWT is discussed. Secondly, a new method to estimate the atmosphere transmission coefficient is designed after analyzing the atmosphere radiation model and the dark channel priori theory. Then, a cloud removal algorithm from single images is proposed by combining DTCWT and the improved atmosphere transmission. Its implement procedures are described completed. Image processing experiments are carried out and evaluated. The results prove the proposed algorithm is satisfactory and superior to algorithms based on the weighted wavelet coefficients and the dark channel prior.
Time-fractional inhomogeneous nonlinear diffusion equation: Symmetries, conservation laws, invariant subspaces, and exact solutions
Authors: Feng Wei , Zhao Songlin
Published: November 2018

In this paper, a class of time-fractional inhomogeneous nonlinear diffusion equation (tFINDE) with Riemann–Liouville fractional derivative is studied. All point symmetries admitted by this equation are derived. The optimal system of one-dimensional subalgebras is classified to perform the symmetry reductions. It is shown that the tFINDE can be reduced to fractional ordinary differential equations (FODEs), including Erdélyi–Kober fractional derivatives. As the results, some explicit group-invariant solutions are obtained. Through nonlinear self-adjointness, all conservation laws admitted by tFINDE arising from these point symmetry groups are listed. The method of invariant subspace is also applied to reduce the tFINDE to a two-dimensional dynamical system (DS). The admitted point symmetries of DS are used to derive the exact solutions of DS, which determine the exact solutions of the original tFINDE.
N-fold Darboux transformation and conservation laws of the modified Volterra lattice
Authors: Yu Jian-Ping , Ma Wen-Xiu , Sun Yong-Li , Khalique Chaudry Masood
Published: November 2018

In this work, we study the modified Volterra lattice. Applying the gauge transformation of the associated [Formula: see text] matrix spectral problems, we establish the N-fold Darboux transformation (DT), and then construct a few explicit solutions in terms of determinants upon using the obtained DT. Moreover, all the results are illustrated by the graphs of the solitonic evolution profiles of the aforementioned solutions. Finally, infinitely many conservation laws for the modified Volterra lattice are proposed. The obtained results of this research might be applied to the research on nonlinear phenomena in physics or engineering areas.
Connected choice and the Brouwer fixed point theorem
Authors: Brattka Vasco , Le Roux Stéphane , Miller Joseph S. , Pauly Arno
Published: November 2018

We study the computational content of the Brouwer Fixed Point Theorem in the Weihrauch lattice. Connected choice is the operation that finds a point in a non-empty connected closed set given by negative information. One of our main results is that for any fixed dimension the Brouwer Fixed Point Theorem of that dimension is computably equivalent to connected choice of the Euclidean unit cube of the same dimension. Another main result is that connected choice is complete for dimension greater than or equal to two in the sense that it is computably equivalent to Weak Kőnig’s Lemma. While we can present two independent proofs for dimension three and upward that are either based on a simple geometric construction or a combinatorial argument, the proof for dimension two is based on a more involved inverse limit construction. The connected choice operation in dimension one is known to be equivalent to the Intermediate Value Theorem; we prove that this problem is not idempotent in contrast to the case of dimension two and upward. We also prove that Lipschitz continuity with Lipschitz constants strictly larger than one does not simplify finding fixed points. Finally, we prove that finding a connectedness component of a closed subset of the Euclidean unit cube of any dimension greater than or equal to one is equivalent to Weak Kőnig’s Lemma. In order to describe these results, we introduce a representation of closed subsets of the unit cube by trees of rational complexes.
Rings of dyadic range 1
Authors: Zabavsky Bohdan
Published: November 2018

In this paper, we introduced the concept of a ring of a right (left) dyadic range 1. We proved that a Bezout ring of right (left) dyadic range 1 is a ring of stable range 2. And we proved that a commutative Bezout ring is an elementary divisor ring if and only if it is a ring of dyadic range 1.
An algebraic study of multivariable integration and linear substitution
Authors: Rosenkranz Markus , Gao Xing , Guo Li
Published: November 2018

We set up an algebraic theory of multivariable integration, based on a hierarchy of Rota–Baxter operators and an action of the matrix monoid as linear substitutions. Given a suitable coefficient domain with a bialgebra structure, this allows us to build an operator ring that acts naturally on the given Rota–Baxter hierarchy. We conjecture that the operator relations are a noncommutative Gröbner–Shirshov basis for the ideal they generate.
The powers of unmixed bipartite edge ideals
Authors: Banerjee Arindam , Mukundan Vivek
Published: November 2018

In this paper, we study the depth and the Castelnuovo–Mumford regularity of the powers of edge ideals which are unmixed and whose underlying graphs are bipartite. In particular, we prove that the depth of the powers of the edge ideal stabilizes when the exponent is the same as half the number of vertices in the underlying connected bipartite graph. We also define the idea of “drop” in the sequence of depth of powers of ideals. Further, we show that the sequence of depth of the powers of such edge ideals may have any number of “drops”. In the process of proving these results we put forward some interesting examples and some questions for future research. As for regularity, we establish a formula for the regularity of the powers of such edge ideals in terms of the regularity of the edge ideal itself.
The existence and representation of the Drazin inverse of a 2 × 2 block matrix over a ring
Authors: Zou Honglin , Mosić Dijana , Chen Jianlong
Published: November 2018

In this paper, further results on the Drazin inverse are obtained in a ring. Several representations of the Drazin inverse of [Formula: see text] block matrices over an arbitrary ring are given under new conditions. Also, upper bounds for the Drazin index of block matrices are studied. Numerical examples are given to illustrate our results. Necessary and sufficient conditions for the existence as well as the expression of the group inverse of block matrices are obtained under certain conditions. In particular, some results of related papers which were considered for complex matrices, operator matrices and matrices over a skew field are extended to more general setting.
On cyclic hypergroups
Authors: Gu Ze
Published: November 2018

In this paper, we introduce the concept of the index of a generator in a cyclic hypergroup, and show that a single power cyclic hypergroup is generated by an element with index [Formula: see text]. Also, a characterization of the fundamental relation on a cyclic hypergroup is given. Finally, we study corresponding quotient structures induced by regular (strongly regular) relations on cyclic hypergroups. As an application, the corresponding results on single power hypergroups are obtained.
Almost symmetric numerical semigroups with given Frobenius number and type
Authors: Branco M. B. , Ojeda I. , Rosales J. C.
Published: November 2018

We give two algorithmic procedures to compute the whole set of almost symmetric numerical semigroups with fixed Frobenius number and type, and the whole set of almost symmetric numerical semigroups with fixed Frobenius number. Our algorithms allow to compute the whole set of almost symmetric numerical semigroups with fixed Frobenius number with similar or even higher efficiency that the known ones. They have been implemented in the GAP [The GAP Group, GAP — Groups, Algorithms and Programming, Version 4.8.6; 2016, https://www.gap-system.org ] package NumericalSgps [M. Delgado and P. A. García-Sánchez and J. Morais, “numericalsgps”: A GAP package on numerical semigroups, https://github.com/gap-packages/numericalsgps ].
Vanishing coefficients in some q-series expansions
Authors: Tang Dazhao
Published: November 2018

Motivated by the recent work of Hirschhorn on vanishing coefficients of the arithmetic progressions in certain [Formula: see text]-series expansions, we study some variants of these [Formula: see text]-series and prove some comparable results. For instance, let [Formula: see text] then [Formula: see text]
A generalization of the subspace theorem for higher degree polynomials in subgeneral position
Authors: Quang Si Duc
Published: November 2018

In this paper, we prove a generalization of Schmidt’s subspace theorem for polynomials of higher degree in subgeneral position with respect to a projective variety over a number field. Our result improves and generalizes the previous results on Schmidt’s subspace theorem for the case of higher degree polynomials.
Sums of reciprocals of fractional parts
Authors: Fregoli Reynold
Published: November 2018

Let [Formula: see text] and [Formula: see text]. We consider the sum [Formula: see text]. Sharp upper bounds are known when [Formula: see text], using continued fractions or the three-distance theorem. However, these techniques do not seem to apply in higher dimension. We introduce a different approach, based on a general counting result of Widmer for weakly admissible lattices, to establish sharp upper bounds for arbitrary [Formula: see text]. Our result also sheds light on a question raised by Lê and Vaaler in 2013 on the sharpness of their lower bound [Formula: see text].
Parity of the partition function p(n,k)
Authors: Karhadkar Kedar
Published: November 2018

Let [Formula: see text] denote the number of partitions of [Formula: see text] into parts less than or equal to [Formula: see text]. We show several properties of this function modulo 2. First, we prove that for fixed positive integers [Formula: see text] and [Formula: see text], [Formula: see text] is periodic modulo [Formula: see text]. Using this, we are able to find lower and upper bounds for the number of odd values of the function for a fixed [Formula: see text].
On the Hilbert 2-class field of some quadratic number fields
Authors: Azizi Abdelmalek , Rezzougui Mohammed , Taous Mohammed , Zekhnini Abdelkader
Published: November 2018

In this paper, we investigate the cyclicity of the [Formula: see text]-class group of the first Hilbert [Formula: see text]-class field of some quadratic number field whose discriminant is not a sum of two squares. For this, let [Formula: see text] be different prime integers. Put [Formula: see text], and denote by [Formula: see text] its [Formula: see text]-class group and by [Formula: see text] (respectively [Formula: see text]) its first (respectively second) Hilbert [Formula: see text]-class field. Then, we are interested in studying the metacyclicity of [Formula: see text] and the cyclicity of [Formula: see text] whenever the [Formula: see text]-rank of [Formula: see text] is [Formula: see text].
Explicit short intervals for primes in arithmetic progressions on GRH
Authors: Dudek Adrian W. , Grenié Loïc , Molteni Giuseppe
Published: November 2018

We prove explicit versions of Cramér’s theorem for primes in arithmetic progressions, on the assumption of the generalized Riemann hypothesis.
ZnO@Ni–Co–S Core–Shell Nanorods-Decorated Carbon Fibers as Advanced Electrodes for High-Performance Supercapacitors
Authors: Sui Yanwei , Zhang Man , Hu Haihua , Zhang Yuanming , Qi Jiqiu , Wei Fuxiang , Meng Qingkun , He Yezeng , Ren Yaojian , Sun Zhi
Published: November 2018

The interconnected three-dimensional Ni–Co–S nanosheets were successfully deposited on ZnO nanorods by a one-step potentiostatic electrodeposition. The Ni–Co–S nanosheets provide a large electrode/electrolyte interfacial area which has adequate electroactive sites for redox reactions. Electrochemical characterization of the ZnO@Ni–Co–S core–shell nanorods presents high specifc capacitance (1302.5[Formula: see text]F/g and 1085[Formula: see text]F/g at a current density of 1 A/g and 20 A/g), excellent rate capabilities (83.3% retention at 20[Formula: see text]A/g) and great cycling stability (65% retention after 5000 cycles at a current density of 30[Formula: see text]A/g). The outstanding electrochemical performance of the as-prepared electrode material also can be ascribed to these reasons that the special structure improved electrical conductivity and allowed the fast diffusion of electrolyte ions.
S1-Equivariant bordism, invariant metrics of positive scalar curvature, and rigidity of elliptic genera
Authors: Wiemeler Michael
Published: November 2018

We construct geometric generators of the effective [Formula: see text]-equivariant Spin- (and oriented) bordism groups with two inverted. We apply this construction to the question of which [Formula: see text]-manifolds admit invariant metrics of positive scalar curvature. It turns out that, up to taking connected sums with several copies of the same manifold, the only obstruction to the existence of such a metric is an [Formula: see text]-genus of orbit spaces. This [Formula: see text]-genus generalizes a previous definition of Lott for orbit spaces of semi-free [Formula: see text]-actions. As a further application of our results, we give a new proof of the vanishing of the [Formula: see text]-genus of a Spin manifold with nontrivial [Formula: see text]-action originally proven by Atiyah and Hirzebruch. Moreover, based on our computations we can give a bordism-theoretic proof for the rigidity of elliptic genera originally proven by Taubes and Bott–Taubes.
Weak and strong domination in thorn graphs
Authors: Doğan Durgun Derya , Lökçü Berna
Published: November 2018

Let [Formula: see text] be a graph and [Formula: see text] A dominating set [Formula: see text] is a set of vertices such that each vertex of [Formula: see text] is either in [Formula: see text] or has at least one neighbor in [Formula: see text]. The minimum cardinality of such a set is called the domination number of [Formula: see text], [Formula: see text] [Formula: see text] strongly dominates [Formula: see text] and [Formula: see text] weakly dominates [Formula: see text] if (i) [Formula: see text] and (ii) [Formula: see text] A set [Formula: see text] is a strong-dominating set, shortly sd-set, (weak-dominating set, shortly wd-set) of [Formula: see text] if every vertex in [Formula: see text] is strongly (weakly) dominated by at least one vertex in [Formula: see text]. The strong (weak) domination number [Formula: see text] of [Formula: see text] is the minimum cardinality of an sd-set (wd-set). In this paper, we present weak and strong domination numbers of thorn graphs.
Mechanical Properties and Thermal Conductivity of Coal Ash-Recycled High-Density Polyethylene Composite
Authors: Alshabander Ban M. , Mohammed Awattif A. , Khalil Asmaa Sh.
Published: November 2018

In this study, coal ash/recycled plastic composite material was fabricated with post-consumer high-density polyethylene (HDPE) and coal ash particles. The main idea of using coal ash, since it is also a waste product, as reinforcing filler in recycled HDPE is to reduce the cost, develop lightweight and produce environmental-friendly materials. Coal ash/recycled plastic composite have been used in significant applications as construction materials including flooring, landscaping, fencing, railing window framing and roof tiles. Effect of coal ash loading on the mechanical properties and thermal conductivity of coal ash/recycled HDPE composite were determined. It is expected to use waste materials in new field by getting novel composite materials with developed mechanical properties. It was found that coal ash filler indicated significant improvement on the mechanical properties of composites. The results show that the impact decreased tremendously from 57.32 to 15.8[Formula: see text]kJ/m2 with only 30[Formula: see text]wt.% loading of coal ash. The filler increases the elasticity of the material and reduces its ability to absorb deformation energy.
Learning Facial Expressions with 3D Mesh Convolutional Neural Network
Authors: Jin Hai , Lian Yuanfeng , Hua Jing
Published: November 2018

Making machines understand human expressions enables various useful applications in human-machine interaction. In this article, we present a novel facial expression recognition approach with 3D Mesh Convolutional Neural Networks (3DMCNN) and a visual analytics-guided 3DMCNN design and optimization scheme. From an RGBD camera, we first reconstruct a 3D face model of a subject with facial expressions and then compute the geometric properties of the surface. Instead of using regular Convolutional Neural Networks (CNNs) to learn intensities of the facial images, we convolve the geometric properties on the surface of the 3D model using 3DMCNN. We design a geodesic distance-based convolution method to overcome the difficulties raised from the irregular sampling of the face surface mesh. We further present interactive visual analytics for the purpose of designing and modifying the networks to analyze the learned features and cluster similar nodes in 3DMCNN. By removing low-activity nodes in the network, the performance of the network is greatly improved. We compare our method with the regular CNN-based method by interactively visualizing each layer of the networks and analyze the effectiveness of our method by studying representative cases. Testing on public datasets, our method achieves a higher recognition accuracy than traditional image-based CNN and other 3D CNNs. The proposed framework, including 3DMCNN and interactive visual analytics of the CNN, can be extended to other applications.
Aerial path planning for urban scene reconstruction
Authors: Smith Neil , Moehrle Nils , Goesele Michael , Heidrich Wolfgang
Published: November 2018

Small unmanned aerial vehicles (UAVs) are ideal capturing devices for high-resolution urban 3D reconstructions using multi-view stereo. Nevertheless, practical considerations such as safety usually mean that access to the scan target is often only available for a short amount of time, especially in urban environments. It therefore becomes crucial to perform both view and path planning to minimize flight time while ensuring complete and accurate reconstructions.

In this work, we address the challenge of automatic view and path planning for UAV-based aerial imaging with the goal of urban reconstruction from multi-view stereo. To this end, we develop a novel continuous optimization approach using heuristics for multi-view stereo reconstruction quality and apply it to the problem of path planning. Even for large scan areas, our method generates paths in only a few minutes, and is therefore ideally suited for deployment in the field.

To evaluate our method, we introduce and describe a detailed benchmark dataset for UAV path planning in urban environments which can also be used to evaluate future research efforts on this topic. Using this dataset and both synthetic and real data, we demonstrate survey-grade urban reconstructions with ground resolutions of 1 cm or better on large areas (30 000 m
2
).
Video to fully automatic 3D hair model
Authors: Liang Shu , Huang Xiufeng , Meng Xianyu , Chen Kunyao , Shapiro Linda G. , Kemelmacher-Shlizerman Ira
Published: November 2018

Imagine taking a selfie video with your mobile phone and getting as output a 3D model of your head (face and 3D hair strands) that can be later used in VR, AR, and any other domain. State of the art hair reconstruction methods allow either a single photo (thus compromising 3D quality) or multiple views, but they require manual user interaction (manual hair segmentation and capture of fixed camera views that span full 360°). In this paper, we describe a system that can completely automatically create a reconstruction from any video (even a selfie video), and we don't require specific views, since taking your -90°, 90°, and full back views is not feasible in a selfie capture.

In the core of our system, in addition to the automatization components, hair strands are estimated and deformed in 3D (rather than 2D as in state of the art) thus enabling superior results. We provide qualitative, quantitative, and Mechanical Turk human studies that support the proposed system, and show results on a diverse variety of videos (8 different celebrity videos, 9 selfie mobile videos, spanning age, gender, hair length, type, and styling).
Connecting measured BRDFs to analytic BRDFs by data-driven diffuse-specular separation
Authors: Sun Tiancheng , Jensen Henrik Wann , Ramamoorthi Ravi
Published: November 2018

The bidirectional reflectance distribution function (BRDF) is crucial for modeling the appearance of real-world materials. In production rendering, analytic BRDF models are often used to approximate the surface appearance since they are compact and flexible. Measured BRDFs usually have a more realistic appearance, but consume much more storage and are hard to modify. In this paper, we propose a novel framework for connecting measured and analytic BRDFs. First, we develop a robust method for separating a measured BRDF into diffuse and specular components. This is commonly done in analytic models, but has been difficult previously to do explicitly for measured BRDFs. This diffuse-specular separation allows novel measured BRDF editing on the diffuse and specular parts separately. In addition, we conduct analysis on each part of the measured BRDF, and demonstrate a more intuitive and lower-dimensional PCA model than Nielsen
et al.
[2015]. In fact, our measured BRDF model has the same number of parameters (8 parameters) as the commonly used analytic models, such as the GGX model. Finally, we visualize the analytic and measured BRDFs in the same space, and directly demonstrate their similarities and differences. We also design an analytic fitting algorithm for two-lobe materials, which is more robust, efficient and simple, compared to previous non-convex optimization-based analytic fitting methods.
Selective guided sampling with complete light transport paths
Authors: Reibold Florian , Hanika Johannes , Jung Alisa , Dachsbacher Carsten
Published: November 2018

Finding good global importance sampling strategies for Monte Carlo light transport is challenging. While estimators using local methods (such as BSDF sampling or next event estimation) often work well in the majority of a scene, small regions in path space can be sampled insufficiently (e.g. a reflected caustic). We propose a novel data-driven guided sampling method which selectively adapts to such problematic regions and complements the unguided estimator. It is based on complete transport paths, i.e. is able to resolve the correlation due to BSDFs and free flight distances in participating media. It is conceptually simple and places anisotropic truncated Gaussian distributions around guide paths to reconstruct a continuous probability density function (guided PDF). Guide paths are iteratively sampled from the guided as well as the unguided PDF and only recorded if they cause high variance in the current estimator. While plain Monte Carlo samples paths independently and Markov chain-based methods perturb a single current sample, we determine the reconstruction kernels by a set of neighbouring paths. This enables local exploration of the integrand without detailed balance constraints or the need for analytic derivatives. We show that our method can decompose the path space into a region that is well sampled by the unguided estimator and one that is handled by the new guided sampler. In realistic scenarios, we show 4× speedups over the unguided sampler.
A system for acquiring, processing, and rendering panoramic light field stills for virtual reality
Authors: Overbeck Ryan S. , Erickson Daniel , Evangelakos Daniel , Pharr Matt , Debevec Paul
Published: November 2018

We present a system for acquiring, processing, and rendering panoramic light field still photography for display in Virtual Reality (VR). We acquire spherical light field datasets with two novel light field camera rigs designed for portable and efficient light field acquisition. We introduce a novel real-time light field reconstruction algorithm that uses a per-view geometry and a disk-based blending field. We also demonstrate how to use a light field prefiltering operation to project from a high-quality offline reconstruction model into our real-time model while suppressing artifacts. We introduce a practical approach for compressing light fields by modifying the VP9 video codec to provide high quality compression with real-time, random access decompression.

We combine these components into a complete light field system offering convenient acquisition, compact file size, and high-quality rendering while generating stereo views at 90Hz on commodity VR hardware. Using our system, we built a freely available light field experience application called
Welcome to Light Fields
featuring a library of panoramic light field stills for consumer VR which has been downloaded over 15,000 times.
There are 174 subdivisions of the hexahedron into tetrahedra
Authors: Pellerin Jeanne , Verhetsel Kilian , Remacle Jean-FranÇois
Published: November 2018

This article answers an important theoretical question: How many different subdivisions of the hexahedron into tetrahedra are there? It is well known that the cube has five subdivisions into 6 tetrahedra and one subdivision into 5 tetrahedra. However, all hexahedra are not cubes and moving the vertex positions increases the number of subdivisions. Recent hexahedral dominant meshing methods try to take these configurations into account for combining tetrahedra into hexahedra, but fail to enumerate them all: they use only a set of 10 subdivisions among the 174 we found in this article.

The enumeration of these 174 subdivisions of the hexahedron into tetrahedra is our combinatorial result. Each of the 174 subdivisions has between 5 and 15 tetrahedra and is actually a class of 2 to 48 equivalent instances which are identical up to vertex relabeling. We further show that exactly 171 of these subdivisions have a geometrical realization, i.e. there exist coordinates of the eight hexahedron vertices in a three-dimensional space such that the geometrical tetrahedral mesh is valid. We exhibit the tetrahedral meshes for these configurations and show in particular subdivisions of hexahedra with 15 tetrahedra that have a strictly positive Jacobian.
Depth from motion for smartphone AR
Authors: Valentin Julien , Kowdle Adarsh , Barron Jonathan T. , Wadhwa Neal , Dzitsiuk Max , Schoenberg Michael , Verma Vivek , Csaszar Ambrus , Turner Eric , Dryanovski Ivan , Afonso Joao , Pascoal Jose , Tsotsos Konstantine , Leung Mira , Schmidt Mirko , Guleryuz Onur , Khamis Sameh , Tankovitch Vladimir , Fanello Sean , Izadi Shahram , Rhemann Christoph
Published: November 2018

Augmented reality (AR) for smartphones has matured from a technology for earlier adopters, available only on select high-end phones, to one that is truly available to the general public. One of the key breakthroughs has been in
low-compute
methods for six degree of freedom (6DoF) tracking on phones using only the
existing hardware
(camera and inertial sensors). 6DoF tracking is the cornerstone of smartphone AR allowing virtual content to be precisely locked on top of the real world. However, to really give users the impression of believable AR, one requires
mobile depth.
Without depth, even simple effects such as a virtual object being correctly occluded by the real-world is impossible. However, requiring a mobile depth sensor would severely restrict the access to such features. In this article, we provide a novel pipeline for mobile depth that supports a wide array of mobile phones, and uses only the existing monocular color sensor. Through several technical contributions, we provide the ability to compute low latency dense depth maps using only a single CPU core of a wide range of (medium-high) mobile phones. We demonstrate the capabilities of our approach on high-level AR applications including real-time navigation and shopping.
Learning a shared shape space for multimodal garment design
Authors: Wang Tuanfeng Y. , Ceylan Duygu , Popović Jovan , Mitra Niloy J.
Published: November 2018

Designing real and virtual garments is becoming extremely demanding with rapidly changing fashion trends and increasing need for synthesizing realisticly dressed digital humans for various applications. This necessitates creating simple and effective workflows to facilitate authoring sewing patterns customized to garment and target body shapes to achieve desired looks. Traditional workflow involves a trial-and-error procedure wherein a mannequin is draped to judge the resultant folds and the sewing pattern iteratively adjusted until the desired look is achieved. This requires time and experience. Instead, we present a data-driven approach wherein the user directly indicates desired fold patterns simply by sketching while our system estimates corresponding garment and body shape parameters at interactive rates. The recovered parameters can then be further edited and the updated draped garment previewed. Technically, we achieve this via a novel shared shape space that allows the user to seamlessly specify desired characteristics across multimodal input
without
requiring to run garment simulation at design time. We evaluate our approach qualitatively via a user study and quantitatively against test datasets, and demonstrate how our system can generate a rich quality of on-body garments targeted for a range of body shapes while achieving desired fold characteristics. Code and data are available at our project webpage.
Fast depth densification for occlusion-aware augmented reality
Authors: Holynski Aleksander , Kopf Johannes
Published: November 2018

Current AR systems only track sparse geometric features but do not compute depth for all pixels. For this reason, most AR effects are pure overlays that can never be occluded by real objects. We present a novel algorithm that propagates sparse depth to every pixel in near realtime. The produced depth maps are spatio-temporally smooth but exhibit sharp discontinuities at depth edges. This enables AR effects that can fully interact with and be occluded by the real scene. Our algorithm uses a video and a sparse SLAM reconstruction as input. It starts by estimating soft depth edges from the gradient of optical flow fields. Because optical flow is unreliable near occlusions we compute forward and backward flow fields and fuse the resulting depth edges using a novel reliability measure. We then localize the depth edges by thinning and aligning them with image edges. Finally, we optimize the propagated depth smoothly but encourage discontinuities at the recovered depth edges. We present results for numerous real-world examples and demonstrate the effectiveness for several occlusion-aware AR video effects. To quantitatively evaluate our algorithm we characterize the properties that make depth maps desirable for AR applications, and present novel evaluation metrics that capture how well these are satisfied. Our results compare favorably to a set of competitive baseline algorithms in this context.