bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of the magnetic field on coexisting stimulated Raman and Brillouin backscattering of an extraordinary mode
Authors: Vyas Ashish , Singh Ram Kishor , Sharma R. P.
Published: January 2016

This paper presents a model to study the interplay between the stimulated Raman scattering (SRS) and stimulated Brillouin scattering (SBS) in the presence of background magnetic field. This formalism is applicable to laser produced plasma as well as to heating mechanism in toroidal system by an extraordinary electromagnetic wave. In the former case, the magnetic field is self-generated, while in the latter case (toroidal plasmas) magnetic field is applied externally. The behavior of one scattering process is explicitly dependent on the coexisting scattering process as well as on the magnetic field. Explicit expressions for the back-reflectivity of scattered beams (SRS and SBS) are presented. It has been demonstrated that due to the magnetic field and coexistence of the scattering processes (SRS and SBS) the back-reflectivity gets modified significantly. Results are also compared with the three wave interaction case (isolated SRS or SBS case).
InGaAs/InAsSb strained layer superlattices for mid-wave infrared detectors
Authors: Ariyawansa Gamini , Reyner Charles J. , Steenbergen Elizabeth H. , Duran Joshua M. , Reding Joshua D. , Scheihing John E. , Bourassa Henry R. , Liang Baolai L. , Huffaker Diana L.
Published: January 2016

Investigation of growth and properties of InGaAs/InAsSb strained layer superlattices, identified as ternary strained layer superlattices (ternary SLSs), is reported. The material space for the antimony-based SLS detector development is expanded beyond InAs/InAsSb and InAs/(In)GaSb by incorporating Ga into InAs. It was found that this not only provides support for strain compensation but also enhances the infrared (IR) absorption properties. A unique InGaAs/InAsSb SLS exists when the conduction band of InGaAs aligns with that of InAsSb. The bandgap of this specific InGaAs/InAsSb SLS can then be tuned by adjusting the thickness of both constituents. Due to the enhanced electron-hole wavefunction overlap, a significant increase in the absorption coefficient was theoretically predicted for ternary SLS as compared to current state-of-the-art InAs/InAsSb SLS structures, and an approximately 30%–35% increase in the absorption coefficient was experimentally observed. All the samples examined in this work were designed to have the same bandgap of approximately 0.240 eV (5.6 μm) at 150 K.
Magnetostatic effects on switching in small magnetic tunnel junctions
Authors: Bapna Mukund , Piotrowski Stephan K. , Oberdick Samuel D. , Li Mingen , Chien C.-L. , Majetich Sara A.
Published: January 2016

Perpendicular CoFeB/MgO/CoFeB magnetic tunnel junctions with diameters under 100 nm are investigated by conductive atomic force microscopy. Minor loops of the tunnel magnetoresistance as a function of applied magnetic field reveal the hysteresis of the soft layer and an offset due to the magnetostatic field of the hard layer. Within the hysteretic region, telegraph noise is observed in the tunnel current. Simulations show that in this range, the net magnetic field in the soft layer is spatially inhomogeneous, and that antiparallel to parallel switching tends to start near the edge, while parallel to antiparallel reversal favors nucleation in the interior of the soft layer. As the diameter of the tunnel junction is decreased, the average magnitude of the magnetostatic field increases, but the spatial inhomogeneity across the soft layer is reduced.
Interfacial thermal conductance of thiolate-protected gold nanospheres
Authors: Stocker Kelsey M. , Neidhart Suzanne M. , Gezelter J. Daniel
Published: January 2016

Molecular dynamics simulations of thiolate-protected and solvated gold nanoparticles were carried out in the presence of a non-equilibrium heat flux between the solvent and the core of the particle. The interfacial thermal conductance (G) was computed for these interfaces, and the behavior of the thermal conductance was studied as a function of particle size, ligand flexibility, and ligand chain length. In all cases, thermal conductance of the ligand-protected particles was higher than the bare metal–solvent interface. A number of mechanisms for the enhanced conductance were investigated, including thiolate-driven corrugation of the metal surface, solvent ordering at the interface, solvent-ligand interpenetration, and ligand ordering relative to the particle surface. Only the smallest particles exhibited significant corrugation. All ligands permitted substantial solvent-ligand interpenetration, and ligand chain length has a significant influence on the orientational ordering of interfacial solvent. Solvent–ligand vibrational overlap, particularly in the low frequency range (<80 cm−1), was significantly altered by ligand rigidity, and had direct influence on the interfacial thermal conductance.
The “anomalous” dynamics of decahyroisoquinoline revisited
Authors: Casalini R. , Roland C. M.
Published: January 2016

Decahydroisoquinoline (DHIQ) appears to be a unique material—the only non-associated, simple liquid with dynamics deviating from density scaling. To examine whether this anomaly is real, the density, ρ, of DHIQ was measured at temperatures, T, as low as 214 K and pressures up to ∼1.2 GPa. This enabled the equation of state (EoS) to be determined, without extrapolation, over the range of thermodynamic conditions for which the relaxation times had been reported. Using this less ambiguous EoS, we find that within the precision of the available relaxation times, the latter are a function of T/ρ3.9, contrary to previous reports. Thus, the behavior of DHIQ is unexceptional; similar to every non-associated liquid tested to date, its dynamics comply with density scaling.
Continuous-wave laser generated jets for needle free applications
Authors: Berrospe-Rodriguez Carla , Visser Claas Willem , Schlautmann Stefan , Ramos-Garcia Ruben , Fernandez Rivas David
Published: January 2016

We designed and built a microfluidic device for the generation of liquid jets produced by thermocavitation. A continuous wave (CW) laser was focused inside a micro-chamber filled with a light-absorbing solution to create a rapidly expanding vapor bubble. The chamber is connected to a micro-channel which focuses and ejects the liquid jet through the exit. The bubble growth and the jet velocity were measured as a function of the devices geometry (channel diameter D and chamber width A). The fastest jets were those for relatively large chamber size with respect to the channel diameter. Elongated and focused jets up to 29 m/s for a channel diameter of 250 μm and chamber size of 700 μm were obtained. The proposed CW laser-based device is potentially a compact option for a practical and commercially feasible needle-free injector.
Transcription factor 7-like 1 is involved in hypothalamo–pituitary axis development in mice and humans
Authors: Gaston-Massuet Carles , McCabe Mark J. , Scagliotti Valeria , Young Rodrigo M. , Carreno Gabriela , Gregory Louise C. , Jayakody Sujatha A. , Pozzi Sara , Gualtieri Angelica , Basu Basudha , Koniordou Markela , Wu Chun-I , Bancalari Rodrigo E. , Rahikkala Elisa , Veijola Riitta , Lopponen Tuija , Graziola Federica , Turton James , Signore Massimo , Mousavy Gharavy Seyedeh Neda , Charolidi Nicoletta , Sokol Sergei Y. , Andoniadou Cynthia Lilian , Wilson Stephen W. , Merrill Bradley J. , Dattani Mehul T. , Martinez-Barbera Juan Pedro
Published: January 2016

Significance

The relevance of transcription factor 7-like 1 (TCF7L1) during hypothalamo–pituitary (HP) axis development remains unknown. Using mouse genetics, we show that TCF7L1 acts as a transcriptional repressor to regulate the expression of the hypothalamic signals involved in pituitary formation. In addition, we screened a cohort of human patients with forebrain and/or pituitary defects and report two independent missense variants, p.R92P and p.R400Q, in human TCF7L1. Functional studies in vitro and rescue experiments in zebrafish mutants deficient for
tcf7l1a
and
tcf7l1b
show that the p.R92P and p.R400Q variants exhibit reduced repressing activity compared with wild-type TCF7L1. In summary, we identify TCF7L1 as a determinant for the establishment of HP axis development and as a potential candidate gene to be mutated in congenital hypopituitarism.
The LMO2 oncogene regulates DNA replication in hematopoietic cells
Authors: Sincennes Marie-Claude , Humbert Magali , Grondin Benoît , Lisi Véronique , Veiga Diogo F. T. , Haman André , Cazaux Christophe , Mashtalir Nazar , Affar EL Bachir , Verreault Alain , Hoang Trang
Published: January 2016

Significance

Understanding how cell cycle and cell differentiation are coordinated during normal hematopoiesis will reveal molecular insights in leukemogenesis. LIM-only 2 (LMO2) is a transcriptional regulator that controls the erythroid lineage via activation of an erythroid-specific gene expression program. Here, we uncover an unexpected function for LMO2 in controlling DNA replication via protein–protein interactions with essential DNA replication enzymes. To our knowledge, this work provides the first evidence for a nontranscriptional function of LMO2 that drives the cell cycle at the expense of differentiation in the erythroid lineage and in thymocytes when misexpressed following genetic alterations. We propose that the nontranscriptional control of DNA replication uncovered here for LMO2 may be a more common function of oncogenic transcription factors than previously appreciated.
Old French possessives and ellipsis
Authors: Arteaga Deborah , Herschensohn Julia
Published: January 2016

Sáez (2011), to account for Spanish definite articles in ellipsis contexts, such as mi libro y el [e] de Juan ‘my book and that of John’, proposes the Stress Condition on Remnants (SCR), which disallows unstressed syntactic elements to be anaphoric, while allowing definite articles to license empty categories. The focus of our paper is Old French (OF) possessive constructions and their elliptical expressions, such as le mien livre ‘my book’ and le [e] de Jean ‘that of Jean’. OF had a more extensive inventory of possessive constructions than Modern French (MF): lexical genitives, prenominal possessives, and lexical and possessive ellipsis constructions. Adopting Arteaga & Herschensohn’s (2010, 2013) proposal for lexical genitives, Sáez’s (2011) SCR, and Lobeck’s (1995) conditions on ellipsis, we argue that two major diachronic changes led to a difference in licensing of possessives from OF to MF: one, the erosion of morphological marking that led to a loss of the OF two case system, reducing feature strength to license ellipsis (Lobeck 1995), and two, the fact that definite articles became clitics and Phase Heads and thus became subject to the SCR as the prenominal nP domain (Carstens 2003) became a clitic zone prohibiting prenominal stressed possessives.
On capacities and their epistemic extensions
Authors: Castroviejo Miró Elena , Oltra-Massuet Isabel
Published: January 2016

The purpose of this paper is twofold; first, we aim to provide a series of tests that identify Spanish ser capaz ‘be capable’ (henceforth SC) as an ambiguous modal, just like English must or can. Specifically, we observe that SC has not only an abilitative flavor, but also an epistemic one. Second, we want to propose an analysis for SC that can account for this ambiguity and that is in accordance with current theories of modality such as Cinque (1999), Kratzer (1981, 1991), and Hacquard (2009, 2010). In a nutshell, we argue that SC can occupy two different positions, a low one below AspP, which corresponds to the abilitative interpretation, and a high one, above AspP, which translates as the epistemic reading. Concerning the semantics, we claim that SC denotes a slight possibility; i.e., the propositional argument is true in at least one world, but it is always true in the non-ordinary worlds.
Affirmative polar replies in Brazilian Portuguese
Authors: Kato Mary Aizawa
Published: January 2016

This article analyzes affirmative polar replies in Brazilian and European Portuguese (BP/EP), which may consist of just the inflected verb or some polar item. These polar replies have been analyzed as instances of null subjects and VP-Ellipsis. This analysis is untenable for BP, as this variety has been losing categorical null referential subjects since the 19th century. The analysis that will be pursued here, for both BP and EP, is an adaptation of the one proposed in Holmberg (2001) for Finnish, according to which, in simple affirmative answers, which consists of just the inflected verb, the verb moves to a pre-sentential position, followed by Remnant TP-Ellipsis. But BP also differs from Finnish when more complex answers are at stake. With regard to the position and optionality of the affirmative polar item sim (yes), a comparison will be made with Japanese, a language identical to BP with regard to affirmative PRs.
“Toned-up” Spanish
Authors: Lipski John M.
Published: January 2016

In Equatorial Guinea Spanish is in contact with lexical tone languages of the Bantu family. The present study, based on field data, compares naturalistic Guinean Spanish with the Spanish of from Madrid, the dialect zone that served as primary input for the formation of Guinean Spanish. A preliminary analysis reveals partial convergence of a pitch accent system and lexically specified phonological tones. Guinean Spanish maintains one stress per word culminativity but expands obligatoriness by realizing a pitch accent on every syllable lexically marked for stress. The rate at which pitch accents occur is compared with the distribution of High tones in the two most prominent Guinean languages (Bubi and Fang), and it is suggested that Guineans’ incomplete suppression of natively acquired F0 patterns may be facilitated by the metrical structure of Spanish, which provides for regularly occurring pitch accents whose maximum potential density is similar to that of H tones in Bubi and Fang.
Age effects and the discrimination of consonantal and vocalic contrasts in heritage and native Spanish
Authors: Mazzaro Natalia , Cuza Alejandro , Colantoni Laura
Published: January 2016

This study explores the perception of consonantal and vocalic contrasts in two groups of Spanish-English bilingual speakers: heritage speakers and long-term immigrants. We test the discrimination of Spanish stops and mid and high vowels via an AX discrimination task with natural stimuli consisting of real Spanish words. Overall, results revealed no significant differences between heritage speakers and long-term immigrants in their discrimination of Spanish stops and vowels. Both groups were more accurate in their discrimination of vowels than of consonants. As for the discrimination of stops, positional and place effects were observed; i.e. a higher proportion of errors was found in word-initial position and with dorsals. We argue that contact with English does not necessarily affect the discrimination of the Spanish contrasts. Implications of these results for maturational approaches to final L2 attainment are discussed.
The X0 syntax of “dative” clitics and the make-up of clitic combinations in Gallo-Romance
Authors: Pescarini Diego
Published: January 2016

This contribution focuses on the morphosyntax of third person dative clitics in Gallo-Romance. The first part addresses the morphology of clitic elements: in GalloRomance, third person datives can be expressed by an etymological form li(s) deriving from Lat illi(s) or by various kinds of non-etymological formatives, e.g. sg. lui, y, lou; pl. leur, yz, lous, lous-y, les-y, etc. I hypothesize that the above forms lexicalize different portions of the same functional hierarchy. The second part of the chapter focuses on the behaviour of third person dative clitics when combined with another third person clitic. In this context, (Gallo-)Romance varieties exhibit a number of irregularities and two possible orders: accusative > datives (as in both old and modern French), or dative > accusative (as in many French vernaculars). Moreover, in both medieval and present-day dialects, the accusative clitic is frequently dropped when clustered with a third person dative clitic. I wonder about a possible correlation between the morphology of the dative clitic and the make-up of clitic combinations.
High-modulus steels reinforced with ceramic particles through ingot casting process
Authors: Chen S. , Seda P. , Krugla M. , Rijkenberg A.
Published: January 2016

High Young's modulus steels can be fabricated based on the concept of metal matrix composites. In this paper, a number of reinforcing ceramic phases with high Young's modulus are assessed and selected to design compositions for high-modulus steels based on thermodynamic calculations. The steel matrix composites reinforced with boride and carbide phases are produced through ingot casting and are processed thermomechanically to strips following standard processing routes for automotive products. The results show that the Young's modulus of steels in the as-cast condition can be increased using borides and carbides. However, further down-stream processing via conventional thermomechanical processing leads to a gradual degradation of the Young's modulus due to extensive void formation. The opportunities and challenges of ceramic-reinforced high-modulus steels produced via conventional ingot casting and thermomechanical processing for the automotive market are discussed.
Simplification of heat treatment process in a tool steel by aluminium addition
Authors: Li S.-S. , Liu Y.-H. , Song Y.-L. , Kong L.-N. , Liang Y. , Li T.-J. , Zhang R.-H.
Published: January 2016

A novel concept for simplification of heat treatment process in a tool steel by the addition of aluminium has been proposed in this research. The addition of 1.08 wt-% aluminium leads to an approximately fully pearlitic state, of which the cementite lamellae are largely spheroidised. Excessive addition of 1.58 wt-% aluminium would result in the formation of a large amount of δ-ferrite. These results are mainly attributed to the synthetic effect of aluminium on the driving force of pearlite transformation and the inter-spacing distance between the proeutectoid carbides. The mechanical properties’ analyses show that aluminium has promising potential to substantially simplify the processing method for developing a relative low-cost mould steel without the concomitant mechanical properties’ reductions.
‘AMCU by day, workers’ committee by night’: Insurgent Trade Unionism at Anglo Platinum (Amplats) mine, 2012–2014
Authors: Sinwell Luke
Published: January 2016

This article investigates the relationship between the workers’ committee, the National Union of Mineworkers (NUM) and the Association of Mineworkers and Construction Union (AMCU) at Amplats between 2012 and 2014. Drawing from in-depth interviews with worker leaders, it explores the contestation over representation and recognition in the platinum mines during a time when workers waged historic strikes putting forward radical demands for pay increases. There has been a rocky transition (one that is incomplete) from the values and culture of the workers’ committee at Amplats to that of the union – AMCU. Gouldner's critique of Michels’ classic ‘Iron Law of Oligarchy’ provides a useful starting point from which to understand this transition as well as the contemporary mineworkers’ movement in South Africa more generally. Gouldner suggested that Michels ignored democratic impulses thereby putting forth a model which was monolithic and static rather than socially constructed and contextually specific. The article advances the concept of Insurgent Trade Unionism in order to argue that when the rank and file takes on an insurgent character, the trade union's bureaucratic or official power (at the national, regional and branch level) becomes marginal, but only relatively so in this case, as the events reveal.
Geminin deletion in mouse oocytes results in impaired embryo development and reduced fertility
Authors: Ma Xue-Shan , Lin Fei , Wang Zhong-Wei , Hu Meng-Wen , Huang Lin , Meng Tie-Gang , Jiang Zong-Zhe , Schatten Heide , Wang Zhen-Bo , Sun Qing-Yuan
Published: January 2016

Geminin controls proper centrosome duplication, cell division, and differentiation. We investigated the function of geminin in oogenesis, fertilization, and early embryo development by deleting the geminin gene in oocytes from the primordial follicle stage. Oocyte-specific disruption of geminin results in low fertility in mice. Even though there was no evident anomaly of oogenesis, oocyte meiotic maturation, natural ovulation, or fertilization, early embryo development and implantation were impaired. The fertilized eggs derived from mutant mice showed developmental delay, and many were blocked at the late zygote stage. Cdt1 protein was decreased, whereas Chk1 and H2AX phosphorylation was increased, in fertilized eggs after geminin depletion. Our results suggest that disruption of maternal geminin may decrease Cdt1 expression and cause DNA rereplication, which then activates the cell cycle checkpoint and DNA damage repair and thus impairs early embryo development.
A novel imaging method for quantitative Golgi localization reveals differential intra-Golgi trafficking of secretory cargoes
Authors: Tie Hieng Chiong , Mahajan Divyanshu , Chen Bing , Cheng Li , VanDongen Antonius M. J. , Lu Lei
Published: January 2016

Cellular functions of the Golgi are determined by the unique distribution of its resident proteins. Currently, electron microscopy is required for the localization of a Golgi protein at the sub-Golgi level. We developed a quantitative sub-Golgi localization method based on centers of fluorescence masses of nocodazole-induced Golgi ministacks under conventional optical microscopy. Our method is rapid, convenient, and quantitative, and it yields a practical localization resolution of ∼30 nm. The method was validated by the previous electron microscopy data. We quantitatively studied the intra-Golgi trafficking of synchronized secretory membrane cargoes and directly demonstrated the cisternal progression of cargoes from the cis- to the trans-Golgi. Our data suggest that the constitutive efflux of secretory cargoes could be restricted at the Golgi stack, and the entry of the trans-Golgi network in secretory pathway could be signal dependent.
The Boston Children’s Hospital Academy: Development and Initial Assessment of a Hospital-Based Teaching Academy
Authors: Gooding Holly C. , McCarty Caitlin , Millson Rebecca , Jiang Hungyu , Armstrong Elizabeth , Leichtner Alan M.
Published: January 2016

Problem

Medical education academies play an important role in the recognition and career advancement of educators. However, hospital-based clinical faculty have unique professional development needs that may not be met by medical-school-based academies.

Approach

The Boston Children’s Hospital Academy was founded in 2008 to serve the needs of its clinician–educators. It was open to junior faculty scholars and to senior faculty scholars and mentors, including interprofessional educators. To maintain membership, individuals must propose and work toward an education project or serve as a project mentor. In 2012, a survey was sent to all members, and annual project reports were reviewed to assess the academy’s impact.

Outcomes

Sixty-five members completed the survey. The majority agreed that the academy created a community of educators, provided opportunities for networking and scholarship, contributed to their personal identity as an educator, and led to recognition by their chief. Projects addressed curriculum development, faculty development, learner assessment, program assessment, and resource development. They largely focused on graduate medical education and on patient safety and quality. During their tenure in the academy (mean length of membership = 2.4 years), members produced an average of 4.4 education presentations and 1.9 education publications, and 11 members were promoted.

Next Steps

A hospital-based academy provides opportunities for interprofessional faculty development. Next steps include increasing interprofessional membership, wider dissemination of members’ successes, better integration with the hospital’s mission, specifically regarding graduate medical education and patient safety, and additional evaluation of the academy’s impact on project completion and members’ accomplishments.
The Cost of Ménière’s Disease: A Novel Multisource Approach
Authors: Tyrrell Jessica , Whinney David J. , Taylor Timothy
Published: January 2016

Objectives:

To estimate the annual cost of Ménière’s disease and the cost per person in the UK population and to investigate the direct and indirect costs of the condition.

Design:

The authors utilized a multidata approach to provide the first estimate of the cost of Ménière’s. Data from the UK Biobank (a study of 500,000 individuals collected between 2007 and 2012), the Hospital Episode Statistics (data on all hospital admissions in England from 2008 to 2012) and the UK Ménière’s Society (2014) were used to estimate the cost of Ménière’s. Cases were self-reported in the UK Biobank and UK Ménière’s Society, within the Hospital Episode Statistics cases were clinician diagnosed. The authors estimated the direct and indirect costs of the condition, using count data to represent numbers of individuals reporting specific treatments, operations etc. and basic statistical analyses (χ2 tests, linear and logistic regression) to compare cases and controls in the UK Biobank.

Results:

Ménière’s was estimated to cost between £541.30 million and £608.70 million annually (equivalent to US $829.9 to $934.2 million), equating to £3,341 to £3,757 ($5112 to $5748) per person per annum. The indirect costs were substantial, with loss of earnings contributing to over £400 million per annum.

Conclusions:

For the first time, the authors were able to estimate the economic burden of Ménière’s disease. In the UK, the annual cost of this condition is substantial. Further research is required to develop cost–effective treatments and management strategies for Ménière’s to reduce the economic burden of the disease. These findings should be interpreted with caution due to the uncertainties inherent in the analysis.
Adjustment for Variable Adherence Under Hierarchical Structure
Authors: Holmes Tyson H. , Zulman Donna M. , Kushida Clete A.
Published: January 2016

Background:

Variable adherence to assigned conditions is common in randomized clinical trials.

Objectives:

A generalized modeling framework under longitudinal data structures is proposed for regression estimation of the causal effect of variable adherence on outcome, with emphasis upon adjustment for unobserved confounders.

Research Design:

A nonlinear, nonparametric random-coefficients modeling approach is described. Estimates of local average treatment effects among compliers can be obtained simultaneously for all assigned conditions to which participants are randomly assigned within the trial. Two techniques are combined to address time-varying and time-invariant unobserved confounding—residual inclusion and nonparametric random-coefficients modeling. Together these yield a compound, 2-stage residual inclusion, instrumental variables model.

Subjects:

The proposed method is illustrated through a set of simulation studies to examine small-sample bias and in application to neurocognitive outcome data from a large, multicenter, randomized clinical trial in sleep medicine for continuous positive airway pressure treatment of obstructive sleep apnea.

Results:

Results of simulation studies indicate that, relative to a standard comparator, the proposed estimator reduces bias in estimates of the causal effect of variable adherence. Bias reductions were greatest at higher levels of residual variance and when confounders were time varying.

Conclusions:

The proposed modeling framework is flexible in the distributions of outcomes that can be modeled, applicable to repeated measures longitudinal structures, and provides effective reduction of bias due to unobserved confounders.
Female in-nest chatter song increases predation
Authors: Kleindorfer Sonia , Evans Christine , Mahr Katharina
Published: January 2016

Female song is an ancestral trait in songbirds, yet extant females generally sing less than males. Here, we examine sex differences in the predation cost of singing behaviour. The superb fairy-wren (
Malurus cyaneus
) is a Southern Hemisphere songbird; males and females provision the brood and produce solo song year-round. Both sexes had higher song rate during the fertile period and lower song rate during incubation and chick feeding. Females were more likely than males to sing close to or inside the nest. For this reason, female but not male song rate predicted egg and nestling predation. This study identifies a high fitness cost of song when a parent bird attends offspring inside a nest and explains gender differences in singing when there are gender differences in parental care.
The birth of
E
8
out of the spinors of the icosahedron
Authors: Dechant Pierre-Philippe
Published: January 2016

E
8
is prominent in mathematics and theoretical physics, and is generally viewed as an exceptional symmetry in an eight-dimensional (8D) space very different from the space we inhabit; for instance, the Lie group
E
8
features heavily in 10D superstring theory. Contrary to that point of view, here we show that the
E
8
root system can in fact be constructed from the icosahedron alone and can thus be viewed purely in terms of 3D geometry. The 240 roots of
E
8
arise in the 8D Clifford algebra of 3D space as a double cover of the 120 elements of the icosahedral group, generated by the root system
H
3
. As a by-product, by restricting to even products of root vectors (spinors) in the 4D even subalgebra of the Clifford algebra, one can show that each 3D root system induces a root system in 4D, which turn out to also be exactly the exceptional 4D root systems. The spinorial point of view explains their existence as well as their unusual automorphism groups. This spinorial approach thus in fact allows one to construct all exceptional root systems within the geometry of three dimensions, which opens up a novel interpretation of these phenomena in terms of spinorial geometry.
Fragmentation as an aggregation process: the role of defects
Authors: Vledouts A. , Vandenberghe N. , Villermaux E.
Published: January 2016

A cohesive object will eventually break into fragment when experiencing a strong deformation, during an impact for instance. Using necklaces of cohesive magnetized spheres suddenly expanded, we have shown that the fragmentation of this one-dimensional material results from an inverse aggregation cascade (Vledouts
et al.
2015
Proc. R. Soc. A
471, 20150678. (doi:10.1098/rspa.2015.0678)). Here, we explore a variant of this process by changing the force law between the attracting spheres, using hydrogel beads linked by capillary bridges. We also investigate the role of (weak) defects in the cohesion strength and the consequences of a distribution of forces between the beads. It is found that fragment do form by a cascade of aggregations, which is interrupted earlier when the force disorder is stronger.
Replicated divergence in cichlid radiations mirrors a major vertebrate innovation
Authors: McGee Matthew D. , Faircloth Brant C. , Borstein Samuel R. , Zheng Jimmy , Darrin Hulsey C. , Wainwright Peter C. , Alfaro Michael E.
Published: January 2016

Decoupling of the upper jaw bones—jaw kinesis—is a distinctive feature of the ray-finned fishes, but it is not clear how the innovation is related to the extraordinary diversity of feeding behaviours and feeding ecology in this group. We address this issue in a lineage of ray-finned fishes that is well known for its ecological and functional diversity—African rift lake cichlids. We sequenced ultraconserved elements to generate a phylogenomic tree of the Lake Tanganyika and Lake Malawi cichlid radiations. We filmed a diverse array of over 50 cichlid species capturing live prey and quantified the extent of jaw kinesis in the premaxillary and maxillary bones. Our combination of phylogenomic and kinematic data reveals a strong association between biting modes of feeding and reduced jaw kinesis, suggesting that the contrasting demands of biting and suction feeding have strongly influenced cranial evolution in both cichlid radiations.
Experimental macroevolution
Authors: Bell Graham
Published: January 2016

The convergence of several disparate research programmes raises the possibility that the long-term evolutionary processes of innovation and radiation may become amenable to laboratory experimentation. Ancestors might be resurrected directly from naturally stored propagules or tissues, or indirectly from the expression of ancestral genes in contemporary genomes. New kinds of organisms might be evolved through artificial selection of major developmental genes. Adaptive radiation can be studied by mimicking major ecological transitions in the laboratory. All of these possibilities are subject to severe quantitative and qualitative limitations. In some cases, however, laboratory experiments may be capable of illuminating the processes responsible for the evolution of new kinds of organisms.
Winner’s curse correction and variable thresholding improve performance of polygenic risk modeling based on genome-wide association study summary-level data
Authors: Shi Jianxin , Park Ju-Hyun , Duan Jubao , Berndt Sonja , Moy Winton , Yu Kai , Song Lei , Wheeler William , Hua Xing , Silverman Debra , Garcia-Closas Montserrat , Hsiung Chao Agnes , Figueroa Jonine D , Cortessis Victoria K , Malats Núria , Karagas Margaret R , Vineis Paolo , Chang I-Shou , Lin Dongxin , Zhou Baosen , Seow Adeline , Matsuo Keitaro , Hong Yun-Chul , Caporaso Neil E. , Wolpin Brian , Jacobs Eric , Petersen Gloria , Klein Alison P. , Li Donghui , Risch Harvey , Sanders Alan R. , Hsu Li , Schoen Robert E. , Brenner Hermann , Stolzenberg-Solomon Rachael , Gejman Pablo , Lan Qing , Rothman Nathaniel , Amundadottir Laufey T. , Landi Maria Teresa , Levinson Douglas F. , Chanock Stephen J. , Chatterjee Nilanjan ,   MGS (Molecular Genetics of Schizophrenia) GWAS Consortium,   GECCO (The Genetics and Epidemiology of Colorectal Cancer Consortium),   The GAME-ON/TRICL (Transdisciplinary Research in Cancer of the Lung) GWAS Consortium,   PRACTICAL (PRostate cancer AssoCiation group To Investigate Cancer Associated aLterations) Consortium,   PanScan and PanC4 Consortium,   The GAMEON/ELLIPSE Consortium
Published: January 2016

Recent heritability analyses have indicated that genome-wide association studies (GWAS) have the potential to improve genetic risk prediction for complex diseases based on polygenic risk score (PRS), a simple modelling technique that can be implemented using summary-level data from the discovery samples. We herein propose modifications to improve the performance of PRS. We introduce threshold-dependent winner’s-curse adjustments for marginal association coefficients that are used to weight the SNPs in PRS. Further, as a way to incorporate external functional/annotation knowledge that could identify subsets of SNPs highly enriched for associations, we propose variable thresholds for SNPs selection. We applied our methods to GWAS summary-level data of 14 complex diseases. Across all diseases, a simple winner’s curse correction uniformly led to enhancement of performance of the models, whereas incorporation of functional SNPs was beneficial only for selected diseases. Compared to the standard PRS algorithm, the proposed methods in combination led to notable gain in efficiency (25-50% increase in the prediction R2) for 5 of 14 diseases. As an example, for GWAS of type 2 diabetes, winner’s curse correction improved prediction R2from 2.29% based on the standard PRS to 3.10% (P=0.0017) and incorporating functional annotation data further improved R2to 3.53% (P=2χ10-5). Our simulation studies illustrate why differential treatment of certain categories of functional SNPs, even when shown to be highly enriched for GWAS-heritability, does not lead to proportionate improvement in genetic risk-prediction because of non-uniform linkage disequilibrium structure.
Random recurrent networks near criticality capture the broadband power distribution of human ECoG dynamics
Authors: Chaudhuri Rishidev , He Biyu J. , Wang Xiao-Jing
Published: January 2016

The power spectrum of brain electric field potential recordings is dominated by an arrhythmic broadband signal but a mechanistic account of its underlying neural network dynamics is lacking. Here we show how the broadband power spectrum of field potential recordings can be explained by a simple random network of nodes near criticality. Such a recurrent network produces activity with a combination of a fast and a slow autocorrelation time constant, with the fast mode corresponding to local dynamics and the slow mode resulting from recurrent excitatory connections across the network. These modes are combined to produce a power spectrum similar to that observed in human intracranial EEG (i.e., electrocorticography, ECoG) recordings. Moreover, such a network naturally converts input correlations across nodes into temporal autocorrelation of the network activity. Consequently, increased independence between nodes results in a reduction in low-frequency power, which offers a possible explanation for observed changes in ECoG power spectra during task performance. Lastly, changes in network coupling produce changes in network activity power spectra reminiscent of those seen in human ECoG recordings across different arousal states. This model thus links macroscopic features of the empirical ECoG power spectrum to a parsimonious underlying network structure and proposes potential mechanisms for changes in ECoG power spectra observed across behavioral and arousal states. This provides a computational framework within which to generate and test hypotheses about the cellular and network mechanisms underlying whole brain electrical dynamics, their variations across behavioral states as well as abnormalities associated with brain diseases.
Analysis of Two-State Folding Using Parabolic Approximation I: Hypothesis
Authors: Sade Robert S.
Published: January 2016

A model which treats the denatured and native conformers of spontaneously-folding fixed two-state systems as being confined to harmonic Gibbs energy-wells has been developed. Within the assumptions of this model the Gibbs energy functions of the denatured (DSE) and the native state (NSE) ensembles are described by parabolas, with the mean length of the reaction coordinate (RC) being given by the temperature-invariant denaturantmvalue. Consequently, the ensemble-averaged position of the transition state ensemble (TSE) along the RC, and the ensemble-averaged Gibbs energy of the TSE are determined by the intersection of the DSE and the NSE-parabolas. The equations derived enable equilibrium stability and the rate constants to be rationalized in terms of the mean and the variance of the Gaussian distribution of the solvent accessible surface area of the conformers in the DSE and the NSE. The implications of this model for protein folding are discussed.
Cyclic heterotetrameric and low-dimensional hydrogen-bonded polymeric structures in the morpholinium salts of ring-substituted benzoic acid analogues
Authors: Smith Graham , Lynch Daniel E.
Published: January 2016

The morpholinium (tetrahydro-2H-1,4-oxazin-4-ium) cation has been used as a counter-ion in both inorganic and organic salt formation and particularly in metal complex stabilization. To examine the influence of interactive substituent groups in the aromatic rings of benzoic acids upon secondary structure generation, the anhydrous salts of morpholine with salicylic acid, C4H10NO+·C7H5O3−, (I), 3,5-dinitrosalicylic acid, C4H10NO+·C7H3N2O7−, (II), 3,5-dinitrobenzoic acid, C4H10NO+·C7H3N2O6−, (III), and 4-nitroanthranilic acid, C4H10NO+·C7H5N2O4−, (IV), have been prepared and their hydrogen-bonded crystal structures are described. In the crystal structures of (I), (III) and (IV), the cations and anions are linked by moderately strong N—H...Ocarboxylhydrogen bonds, but the secondary structure propagation differs among the three,viz.one-dimensional chains extending along [010] in (I), a discrete cyclic heterotetramer in (III), and in (IV), a heterotetramer with amine N—H...O hydrogen-bond extensions alongb, giving a two-layered ribbon structure. With the heterotetramers in both (III) and (IV), the ion pairs are linked though inversion-related N—H...Ocarboxylatehydrogen bonds, giving cyclicR44(12) motifs. With (II), in which the anion is a phenolate rather than a carboxylate, the stronger assocation is through a symmetric lateral three-centre cyclicR12(6) N—H...(O,O′) hydrogen-bonding linkage involving the phenolate and nitro O-atom acceptors of the anion, with extension through a weaker O—H...Ocarboxylhydrogen bond. This results in a one-dimensional chain structure extending along [100]. In the structures of two of the salts [i.e.(II) and (IV)], there are also π–π ring interactions, with ring-centroid separations of 3.5516 (9) and 3.7700 (9) Å in (II), and 3.7340 (9) Å in (IV).
A threefold interpenetrated two-dimensional zinc(II) supramolecular architecture based on 3-nitrobenzoic acid and 4,4′-bipyridine
Authors: Tang Long , Wang Ji-Jiang , Fu Feng , Wang Sheng-Wen , Liu Qi-Rui
Published: January 2016

With regard to crystal engineering, building block or modular assembly methodologies have shown great success in the design and construction of metal–organic coordination polymers. The critical factor for the construction of coordination polymers is the rational choice of the organic building blocks and the metal centre. The reaction of Zn(OAc)2·2H2O (OAc is acetate) with 3-nitrobenzoic acid (HNBA) and 4,4′-bipyridine (4,4′-bipy) under hydrothermal conditions produced a two-dimensional zinc(II) supramolecular architecture,catena-poly[[bis(3-nitrobenzoato-κ2O,O′)zinc(II)]-μ-4,4′-bipyridine-κ2N:N′], [Zn(C7H4NO4)2(C10H8N2)]nor [Zn(NBA)2(4,4′-bipy)]n, which was characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis and single-crystal X-ray diffraction analysis. The ZnIIions are connected by the 4,4′-bipy ligands to form a one-dimensional zigzag chain and the chains are decorated with anionic NBA ligands which interact further through aromatic π–π stacking interactions, expanding the structure into a threefold interpenetrated two-dimensional supramolecular architecture. The solid-state fluorescence analysis indicates a slight blue shift compared with pure 4,4′-bipyridine and HNBA.
Incentive contract or tenure reform? Understanding the transition of forest resources management in China
Authors: Wei Jiegen , He Haoran
Published: January 2016

Purpose

– China’s government has been facing a trade-off in choosing between tenure reform and forest concessions to manage forest resources. The purpose of this paper is to investigate how the government’s policy choices can be affected by environmental benefits and the economic value of forests.

Design/methodology/approach

– We build a simple theoretical model and employ province-level data.

Findings

– The results show that the government will allocate less forestland to local people if environmental concerns are more important and privatize less forest if the economic benefits from forest are higher.

Social implications

– Therefore, the transformation of forest management policies reflects not only the government’s own preferences but also its gradual adjustment to the changing market and institutional environment.

Originality/value

– The present paper provides a regulation approach that complements the growing literature on forest resource management.
Two dimensions of trust in physicians in OECD-countries
Authors: Saarinen Arttu Olavi , Räsänen Pekka , Kouvo Antti
Published: January 2016

Purpose

– The purpose of this paper is to analyse citizens’ trust in physicians in 22 OECD countries.

Design/methodology/approach

– The authors measure trust in physicians using items on generalised and particularised trust. Individual-level data are received from the ISSP Research Group (2011). The authors also utilise macro variables drawn from different data banks. Data were analysed using descriptive statistics and xtlogit regression models. The main micro-level hypothesis is that low self-reported health is strongly associated with lower trust in physicians. The second micro-level hypothesis is that frequent meetings with physicians result in higher trust. The third micro-level hypothesis assumes that males, and older and better educated respondents, express higher trust compared to others. The first macro-level hypothesis is that lower income inequality leads to higher trust in physicians. The second macro-level hypothesis is that greater physician density leads to higher trust in physicians.

Findings

– The authors found that the influence of individual and macro-level characteristics varies between trust types. Results indicate that both trust types are clearly associated with individual-level determinants. However, only general trust in physicians has weak associations with macro-level indicators (mainly physician density) and therefore on institutional cross-country differences. It seems that particularised trust in a physician’s skills is more restricted to the individuals’ health and their own experiences meeting doctors, whereas general trust likely reflects attitudes towards the prevalent profession in the country.

Originality/value

– The findings hold significance for healthcare systems research and for research concerning social trust generally.
LEAN thinking in Finnish healthcare
Authors: Jorma Tapani , Tiirinki Hanna , Bloigu Risto , Turkki Leena
Published: January 2016

Purpose

– The purpose of this study is to evaluate how LEAN thinking is used as a management and development tool in the Finnish public healthcare system and what kind of outcomes have been achieved or expected by using it. The main focus is in managing and developing patient and treatment processes.

Design/methodology/approach

– A mixed-method approach incorporating the Webropol survey was used.

Findings

– LEAN is quite a new concept in Finnish public healthcare. It is mainly used as a development tool to seek financial savings and to improve the efficiency of patient processes, but has not yet been deeply implemented. However, the experiences from LEAN initiatives have been positive, and the methodology is already quite well-known. It can be concluded that, because of positive experiences from LEAN, the environment in Finnish healthcare is ready for the deeper implementation of LEAN.

Originality/value

– This paper evaluates the usage of LEAN thinking for the first time in the public healthcare system of Finland as a development tool and a management system. It highlights the implementation and achieved results of LEAN thinking when used in the healthcare environment. It also highlights the expectations for LEAN thinking in Finnish public healthcare.