bluuebunny/crossref_metadata_2025_split huggingface dataset:
A generalisation of the arbelos theorem of Archimedes
Authors: Shirali Shailesh A 
Published: June 2016

Over two thousand years ago, Archimedes discovered a remarkable result concerning two circles drawn with reference to a configuration of three circles and a straight line. Figure 1 displays this result.In the figure, A, B, C are three collinear points, with B between A and C; circles ω1, ω2, ω3 are drawn on AB, BC, AC as diameters, respectively; a line l is drawn through B, perpendicular to AC; a circle ω4 is inscribed in the region bounded by {ωl, ω3, l}; and a circle ω5 is inscribed in the region bounded by {ω2, ω3, l}. The Archimedean property is that ω4 and ω5 have equal radii.
Finding a missing digit
Authors: Shiu Peter 
Published: June 2016

‘There is a simple argument which shows that, for any positive real number x, the digit 7 appears in the decimal representation of one of the numbers x, 2x, … , 79x. I spent a wet Saturday afternoon showing that 79 can be reduced to 42, which is best possible.’Some thirty years ago this interesting problem was given to me verbally by David Masser, who was a reader in mathematics at Nottingham University. I solved the problem, over several days, and forgot about it. While tidying up papers in retirement I found the notes on the problem, and when I mentioned this to David he too had forgotten about it until he searched through his notes. He now encourages me to publicise the problem, which is presented here with a small extension.
Some remarks about a formula of Charles Dodgson
Authors: Pla Juan 
Published: June 2016

In this note we start by exploring a type of solution of the equation in positive integersfor a given p, which will enable us easily to derive a class of solutions in integers of the more general equation in positive integersfor any positive integers p and n.In another part of this note we explore some connections between the formula we find and a particular chapter in the elementary theory of numbers.
Metric axioms and distance
Authors: Cullinane Michael J. 
Published: June 2016

Many mathematicians' experiences with distances in the settings of geometry, analysis, and topology can lead to the impression that the only worthwhile or ‘reasonable’ distance functions are metrics. We hope to convince the reader otherwise.Recall that ametricfor a setXis a functiond: X × X→ [0, ∞) satisfying all of the followingmetric axioms:
The 6666 Problem
Authors: Eggleton Roger , Ostaszewski Krzysztof 
Published: June 2016

How many times must a die be thrown to get four consecutive sixes? More generally, and more precisely,Q1. What is the expected number of times we must throw a die to get n consecutive sixes?The answer, rather suggestively for the numerologically inclined, turns out to beA1. The expected number of throws is 6 + 62 + 63 + … + 6n.In some well-known dice games players throw several dice at the same time: in craps a pair (brace) of dice is thrown, while in yahtzee, yam and balut, up to five dice are thrown at a time. However, Q1 is not the same as
What is the most symmetric quadrilateral?
Authors: Beardon A. F. 
Published: June 2016

What is the most symmetric quadrilateral you can think of? Most people would say ‘a square’, but having given this (or any other) answer, can you create your own definition of a ‘quadrilateral’, and of ‘most symmetric’, so that you can justify your answer as a rigorous piece of mathematics? This is a challenging investigation because the answer may not be the obvious one.Often the main difficulty in solving a problem lies in finding appropriate definitions; here we must first consider the questions ‘what is a quadrilateral?’, and ‘what is a symmetry of a quadrilateral?’.
A curious misattribution: the early history of ‘Simson's line’
Authors: Quadling Douglas 
Published: June 2016

When William Wynne Willson died in the summer of 2010 he left behind an incomplete text covering a number of geometrical topics, including the so-called ‘Simson line’. Geoff Wain, who was completing and editing the text with a view to possible publication, sent me a copy. One chapter, entitled ‘Whose line is it anyway?’ contains the following paragraph.‘In 1799 the Scottish mathematician William Wallace … published a geometric theorem. Nowadays this result is known as ‘Simson's line’. It is not clear why it should have this name as Robert Simson, another Scottish mathematician, had died aged 80 in 1768, the year in which Wallace was born. Although Simson published a considerable body of mathematical writings … there seems to be no trace of this theorem among them.
Variations on a theme – Euler and the logsine integral
Authors: Lord Nick 
Published: June 2016

This article concerns the evaluation of the ‘logsine’ integralWe shall encounter it in several guises. Indeed, standard integration techniques used below readily show that (1) has the same value as the following integrals:En passant, it is worth noting that forms (6) and (7) are the best behaved for numerical integration.I first met the logsine integral as a callow youth in that strange hinterland of results that you may not have met at school but were not guaranteed to meet later on either.
How to see a cube moving into its mirror image
Authors: Dalvit Ester , Luminati Domenico 
Published: June 2016

In n-dimensional Euclidean space no reflection with respect to a hyperplane can be realised by a rigid motion. But this is possible if we allow rigid motions in (n + 1)-dimensional space. These notes show a way to visualise a rigid motion of a cube in 4-dimensional space that flips the cube ‘as the page of a book’.The two terms rigid motion and isometry are sometimes used as synonyms. Yet they do refer to different concepts. The first one has a purely kinematic connotation: the swing of a door or the movement of a piece of furniture pushed over the floor are described by rigid motions. On the other hand to ensure that two figures are isometric it is enough that there exists a correspondence between their points that maintains the relative distances.
A mix of community-based conservation and protected forests is needed for the survival of the Endangered pygmy hippopotamusChoeropsis liberiensis
Authors: Hillers Annika , Buchanan Graeme M. , Garteh Jerry C. , Tommy Solomon M. , Fofana Mohamed L. , Lindsell Jeremy A. 
Published: June 2016

AbstractThe contribution of protected areas to biodiversity conservation is well attested but many taxa in many regions remain dependent on the unprotected wider landscape. To develop conservation plans for large mammals such as the Endangered pygmy hippopotamusChoeropsis liberiensisof West Africa's Upper Guinea Forests it is critical to understand the importance of unprotected land. Despite being a conservation priority, little is known about the habitat associations of this species, or its distribution across its range. Through a combination of field surveys, species distribution models and community questionnaires we investigated the use of unprotected areas by the pygmy hippopotamus in the Sierra Leone–Liberia border region. We found signs of the species in 128 of 525 1-km2cells surveyed. Our analysis suggested that the species is reasonably widespread in this region and is associated with major rivers. It occurred close to, but rarely within, large areas of intact forest, and 80.4% of pygmy hippopotamus signs were recorded outside protected areas. The expansion of the protected area network in this area is unrealistic in Sierra Leone and to some extent in Liberia, mainly because of anthropogenic pressure and the overlap of proposed protected areas with mining and logging concessions. Thus pygmy hippopotamus conservation activities in the region need to include programmes on community lands while maintaining a robust network of protected forests. Community-based conservation of the pygmy hippopotamus may prove valuable for other threatened and endemic species that are not confined to protected areas in this region.
TUBER, RHIZOME, TENDRIL AND CORM: ON THE MUSIC OF MARTIN ARNOLD
Authors: Höstman Anna K. 
Published: June 2016

AbstractMartin Arnold is an experimental composer currently residing in Toronto, Canada. His unique approach to composition originates in the close relationship that he developed with Czech-Canadian composer Rudolf Komorous while Arnold was a doctoral student at the University of Victoria. Martin Arnold's desire to create music both familiar and unfamiliar, known and unknown, generates paradoxical listening experiences that reside on the edges of things. In this article, the author explores a number of these edges and meeting places, especially as they occur within the composer's very singular string quartet, Contact; Vault.
Discounting pension liabilities: funding versus value
Authors: BROWN JEFFREY R. , PENNACCHI GEORGE G. 
Published: June 2016

AbstractWe argue that the appropriate discount rate for pension liabilities depends on the objective. In particular, if the objective is to measure pension under- or overfunding, a default-free discount rate should always be used, even if the liabilities are themselves not default-free. If, instead, the objective is to determine the market value of pension benefits, then it is appropriate that discount rates incorporate default risk. We also discuss the choice of a default-free discount rate. Finally, we show how cost-of-living adjustments that are common in public pensions can be accounted for and valued in this framework.
Ludwig von Mises's approach to capital as a bridge between Austrian and institutional economics
Authors: BRAUN EDUARD , LEWIN PETER , CACHANOSKY NICOLÁS 
Published: June 2016

AbstractLudwig von Mises seems to be something of an outlier within the Austrian school when it comes to capital – though his position is clearly foreshadowed in a neglected article by Carl Menger (1888). In this paper, we examine Mises's view on capital and suggest that it constitutes a bridge between Austrian and institutional economics. As an outflow of Mises's approach, an incipient financial approach may be discerned, an approach to capital that integrates concepts from financial theory into a broader view of capital that contains both institutional and Austrian elements.
Brillouin scattering self-cancellation
Authors: Florez O. , Jarschel P. F. , Espinel Y. A. V. , Cordeiro C. M. B. , Mayer Alegre T. P. , Wiederhecker G. S. , Dainese P. 
Published: June 2016

AbstractThe interaction between light and acoustic phonons is strongly modified in sub-wavelength confinement, and has led to the demonstration and control of Brillouin scattering in photonic structures such as nano-scale optical waveguides and cavities. Besides the small optical mode volume, two physical mechanisms come into play simultaneously: a volume effect caused by the strain-induced refractive index perturbation (known as photo-elasticity), and a surface effect caused by the shift of the optical boundaries due to mechanical vibrations. As a result, proper material and structure engineering allows one to control each contribution individually. Here, we experimentally demonstrate the perfect cancellation of Brillouin scattering arising from Rayleigh acoustic waves by engineering a silica nanowire with exactly opposing photo-elastic and moving-boundary effects. This demonstration provides clear experimental evidence that the interplay between the two mechanisms is a promising tool to precisely control the photon–phonon interaction, enhancing or suppressing it.
Cholesterol and ORP1L-mediated ER contact sites control autophagosome transport and fusion with the endocytic pathway
Authors: Wijdeven Ruud H. , Janssen Hans , Nahidiazar Leila , Janssen Lennert , Jalink Kees , Berlin Ilana , Neefjes Jacques 
Published: June 2016

AbstractAutophagy is the main homeostatic pathway guiding cytosolic materials for degradation by the lysosome. Maturation of autophagosomes requires their transport towards the perinuclear region of the cell, with key factors underlying both processes still poorly understood. Here we show that transport and positioning of late autophagosomes depends on cholesterol by way of the cholesterol-sensing Rab7 effector ORP1L. ORP1L localizes to late autophagosomes and—under low-cholesterol conditions—contacts the ER protein VAP-A, forming ER-autophagosome contact sites, which prevent minus-end transport by the Rab7–RILP–dynein complex. ORP1L-mediated contact sites also inhibit localization of PLEKHM1 to Rab7. PLEKHM1, together with RILP, then recruits the homotypic fusion and vacuole protein-sorting (HOPS) complex for fusion of autophagosomes with late endosomes and lysosomes. Thus, ORP1L, via its liganding by lipids and the formation of contacts between autophagic vacuoles and the ER, governs the last steps in autophagy that lead to the lysosomal degradation of cytosolic material.
Multiple unpinned Dirac points in group-Va single-layers with phosphorene structure
Authors: Lu Yunhao , Zhou Di , Chang Guoqing , Guan Shan , Chen Weiguang , Jiang Yinzhu , Jiang Jianzhong , Wang Xue-sen , Yang Shengyuan A , Feng Yuan Ping , Kawazoe Yoshiyuki , Lin Hsin 
Published: June 2016

AbstractEmergent Dirac fermion states underlie many intriguing properties of graphene, and the search for them constitutes one strong motivation to explore two-dimensional (2D) allotropes of other elements. Phosphorene, the ultrathin layers of black phosphorous, has been a subject of intense investigations recently, and it was found that other group-Va elements could also form 2D layers with similar puckered lattice structure. Here, by a close examination of their electronic band structure evolution, we discover two types of Dirac fermion states emerging in the low-energy spectrum. One pair of (type-I) Dirac points is sitting on high-symmetry lines, while two pairs of (type-II) Dirac points are located at generic k-points, with different anisotropic dispersions determined by the reduced symmetries at their locations. Such fully-unpinned (type-II) 2D Dirac points are discovered for the first time. In the absence of spin-orbit coupling (SOC), we find that each Dirac node is protected by the sublattice symmetry from gap opening, which is in turn ensured by any one of three point group symmetries. The SOC generally gaps the Dirac nodes, and for the type-I case, this drives the system into a quantum spin Hall insulator phase. We suggest possible ways to realise the unpinned Dirac points in strained phosphorene.
The complete genome of a baculovirus isolated from an insect of medical interest: Lonomia obliqua (Lepidoptera: Saturniidae)
Authors: Aragão-Silva C. W. , Andrade M. S. , Ardisson-Araújo D. M. P. , Fernandes J. E. A. , Morgado F. S. , Báo S. N. , Moraes R. H. P. , Wolff J. L. C. , Melo F. L. , Ribeiro B. M. 
Published: June 2016

AbstractLonomia obliqua (Lepidoptera: Saturniidae) is a species of medical importance due to the severity of reactions caused by accidental contact with the caterpillar bristles. Several natural pathogens have been identified in L. obliqua, and among them the baculovirus Lonomia obliqua multiple nucleopolyhedrovirus (LoobMNPV). The complete genome of LoobMNPV was sequenced and shown to have 120,022 bp long with 134 putative open reading frames (ORFs). Phylogenetic analysis of the LoobMNPV genome showed that it belongs to Alphabaculovirus group I (lepidopteran-infective NPV). A total of 12 unique ORFs were identified with no homologs in other sequenced baculovirus genomes. One of these, the predicted protein encoded by loob035, showed significant identity to an eukaryotic transcription terminator factor (TTF2) from the Lepidoptera Danaus plexippus, suggesting an independent acquisition through horizontal gene transfer. Homologs of cathepsin and chitinase genes, which are involved in host integument liquefaction and viral spread, were not found in this genome. As L. obliqua presents a gregarious behavior during the larvae stage the impact of this deletion might be neglectable.
Fourier ptychographic reconstruction using Poisson maximum likelihood and truncated Wirtinger gradient
Authors: Bian Liheng , Suo Jinli , Chung Jaebum , Ou Xiaoze , Yang Changhuei , Chen Feng , Dai Qionghai 
Published: June 2016

AbstractFourier ptychographic microscopy (FPM) is a novel computational coherent imaging technique for high space-bandwidth product imaging. Mathematically, Fourier ptychographic (FP) reconstruction can be implemented as a phase retrieval optimization process, in which we only obtain low resolution intensity images corresponding to the sub-bands of the sample’s high resolution (HR) spatial spectrum and aim to retrieve the complex HR spectrum. In real setups, the measurements always suffer from various degenerations such as Gaussian noise, Poisson noise, speckle noise and pupil location error, which would largely degrade the reconstruction. To efficiently address these degenerations, we propose a novel FP reconstruction method under a gradient descent optimization framework in this paper. The technique utilizes Poisson maximum likelihood for better signal modeling and truncated Wirtinger gradient for effective error removal. Results on both simulated data and real data captured using our laser-illuminated FPM setup show that the proposed method outperforms other state-of-the-art algorithms. Also, we have released our source code for non-commercial use.
Mycobacterium leprae-induced Insulin-like Growth Factor I attenuates antimicrobial mechanisms, promoting bacterial survival in macrophages
Authors: Batista-Silva L. R. , Rodrigues Luciana Silva , Vivarini Aislan de Carvalho , Costa Fabrício da Mota Ramalho , Mattos Katherine Antunes de , Costa Maria Renata Sales Nogueira , Rosa Patricia Sammarco , Toledo-Pinto T. G. , Dias André Alves , Moura Danielle Fonseca , Sarno Euzenir Nunes , Lopes Ulisses Gazos , Pessolani Maria Cristina Vidal 
Published: June 2016

AbstractMycobacterium leprae (ML), the etiologic agent of leprosy, can subvert macrophage antimicrobial activity by mechanisms that remain only partially understood. In the present study, the participation of hormone insulin-like growth factor I (IGF-I) in this phenomenum was investigated. Macrophages from the dermal lesions of the disseminated multibacillary lepromatous form (LL) of leprosy expressed higher levels of IGF-I than those from the self-limited paucibacillary tuberculoid form (BT). Higher levels of IGF-I secretion by ML-infected macrophages were confirmed in ex vivo and in vitro studies. Of note, the dampening of IGF-I signaling reverted the capacity of ML-infected human and murine macrophages to produce antimicrobial molecules and promoted bacterial killing. Moreover, IGF-I was shown to inhibit the JAK/STAT1-dependent signaling pathways triggered by both mycobacteria and IFN-γ most probably through its capacity to induce the suppressor of cytokine signaling-3 (SOCS3). Finally, these in vitro findings were corroborated by in vivo observations in which higher SOCS3 expression and lower phosphorylation of STAT1 levels were found in LL versus BT dermal lesions. Altogether, our data strongly suggest that IGF-I contributes to the maintenance of a functional program in infected macrophages that suits ML persistence in the host, reinforcing a key role for IGF-I in leprosy pathogenesis.
Comparative transcriptomic analysis of human and Drosophila extracellular vesicles
Authors: Lefebvre Fabio Alexis , Benoit Bouvrette Louis Philip , Perras Lilyanne , Blanchet-Cohen Alexis , Garnier Delphine , Rak Janusz , Lécuyer Éric 
Published: June 2016

AbstractExtracellular vesicles (EVs) are membrane-enclosed nanoparticles containing specific repertoires of genetic material. In mammals, EVs can mediate the horizontal transfer of various cargos and signaling molecules, notably miRNA and mRNA species. Whether this form of intercellular communication prevails in other metazoans remains unclear. Here, we report the first parallel comparative morphologic and transcriptomic characterization of EVs from Drosophila and human cellular models. Electronic microscopy revealed that human and Drosophila cells release similar EVs with diameters ranging from 30 to 200 nm, which contain complex populations of transcripts. RNA-seq identified abundant ribosomal RNAs, related pseudogenes and retrotransposons in human and Drosophila EVs. Vault RNAs and Y RNAs abounded in human samples, whereas small nucleolar RNAs involved in pseudouridylation were most prevalent in Drosophila EVs. Numerous mRNAs were identified, largely consisting of exonic sequences displaying full-length read coverage and enriched for translation and electronic transport chain functions. By analogy with human systems, these sizeable similarities suggest that EVs could potentially enable RNA-mediated intercellular communication in Drosophila.
Transcriptomic analysis of submergence-tolerant and sensitive Brachypodium distachyon ecotypes reveals oxidative stress as a major tolerance factor
Authors: Rivera-Contreras Irma Karla , Zamora-Hernández Teresa , Huerta-Heredia Ariana Arlene , Capataz-Tafur Jacqueline , Barrera-Figueroa Blanca Estela , Juntawong Piyada , Peña-Castro Julián Mario 
Published: June 2016

AbstractWhen excessive amounts of water accumulate around roots and aerial parts of plants, submergence stress occurs. To find the integrated mechanisms of tolerance, we used ecotypes of the monocot model plantBrachypodium distachyonto screen for genetic material with contrasting submergence tolerance. For this purpose, we used a set of previously studied drought sensitive/tolerant ecotypes and the knowledge that drought tolerance is positively associated with submergence stress. We decided to contrast aerial tissue transcriptomes of the ecotype Bd21 14-day-old plants as sensitive and ecotype Bd2-3 as tolerant after 2 days of stress under a long-day photoperiod. Gene ontology and the grouping of transcripts indicated that tolerant Bd2-3 differentially down-regulatedNITRATE REDUCTASEandALTERNATIVE OXIDASEunder stress and constitutively up-regulatedHAEMOGLOBIN, when compared with the sensitive ecotype, Bd21. These results suggested the removal of nitric oxide, a gaseous phytohormone and concomitant reactive oxygen species as a relevant tolerance determinant. Other mechanisms more active in tolerant Bd2-3 were the pathogen response, glyoxylate and tricarboxylic acid cycle integration and acetate metabolism. This data set could be employed to design further studies on the basic science of plant tolerance to submergence stress and its biotechnological application in the development of submergence-tolerant crops.
Comparison of Tunable Diode Laser Absorption Spectroscopy and Isothermal Micro-calorimetry for Non-invasive Detection of Microbial Growth in Media Fills
Authors: Brueckner David , Roesti David , Zuber Ulrich Georg , Schmidt Rainer , Kraehenbuehl Stefan , Bonkat Gernot , Braissant Olivier 
Published: June 2016

AbstractTwo methods were investigated for non-invasive microbial growth-detection in intact glass vials as possible techniques for automated inspection of media-filled units. Tunable diode laser absorption spectroscopy (TDLAS) was used to determine microbially induced changes in O2 and CO2 concentrations within the vial headspaces. Isothermal microcalorimetry (IMC) allowed the detection of metabolic heat production. Bacillus subtilis and Streptococcus salivarius were chosen as test organisms. Parameters as robustness, sensitivity, comparability and time to detection (TtD) were evaluated to assess method adequacy. Both methods robustly detected growth of the tested microorganisms within less than 76 hours using an initial inoculum of <10CFU. TDLA"Equation missing" turned out to be less sensitive than TDLA"Equation missing" and IMC, as some false negative results were observed. Compared to the visual media-fill examination of spiked samples, the investigated techniques were slightly slower regarding TtD. Although IMC showed shorter TtD than TDLAS the latter is proposed for automating the media-fill inspection, as larger throughput can be achieved. For routine use either TDLA"Equation missing" or a combination of TDLA"Equation missing" and TDLA"Equation missing" should be considered. IMC may be helpful for replacing the sterility assessment of commercial drug products before release.