bluuebunny/crossref_metadata_2025 huggingface dataset:
Annual measured performance of building-integrated solar energy systems in demonstration low-energy solar house
Authors: Lee Kyoung-ho , Lee Jin-kook , Yoon Eung-sang , Joo Moon-chang , Lee Soon-myoung , Baek Nam-choon
Published: August 2014

This paper presents the details of the output and efficiency of the annual performance of building-integrated solar energy systems for a solar water heating system and solar photovoltaic (PV) modules of a demonstration near-zero-energy solar house that was constructed on the campus of the Korea Institute of Energy Research. The thermal systems installed in the house were a solar water heating system with building-integrated solar collectors for water heating and for part of the space heating, and a ground-coupled heat pump for space cooling and part of the space heating. Solar PV modules were installed on the roof of the house. The performance of these systems was monitored for more than 1 yr. The annual efficiencies of the building's integrated solar collectors and solar PV were 22.8% and 10.9%, respectively. The total annual solar fraction of the solar heating system was 69.7%, with an annual solar heat production of 248 kW h/m2. This paper also focuses on the efficiency of the house's solar storage, based upon intentionally varied drainage of hot water from the storage tank. It was found that the thermal loss from the solar storage tank has a strong functional relationship with the thermal demand of the solar storage tank per unit volume. For example, when the hot water consumption was reduced by half during September, the thermal loss increased to more than 70%, which would otherwise have been around 30%.
Benchtop fabrication of multi-scale micro-electromagnets for capturing magnetic particles
Authors: Hosseini A. , Soleymani L.
Published: August 2014

Micro-electromagnets hold great promise for integration into portable and handheld lab-on-a- chip systems applicable to point-of-care disease management. Two major requirements must be satisfied in order for such devices to be applicable into practical, miniaturized, and portable biomedical instrumentation: low power operation and low-cost fabrication. In this paper, we use numerical modeling combined with a lithography-free fabrication process to create micro-electromagnets on a polymer substrate. Numerical modeling reveals that active-passive devices—ferromagnetic layers coupled with current-controlled planar coils—are essential for generating a sufficient magnetic force for magnetic particle manipulation at low currents (<50 mA). In addition, it is shown that current carrying conductors created from micro/nanotextured materials further enhance the generated magnetic force at a given current. To combine low-cost fabrication with low-current operation, we developed a benchtop fabrication method based on craft cutting, polymer induced thin film wrinkling, and electrodeposition to create a multilevel arrangement of multi-scale materials essential for low-current operation. We demonstrate that the fabricated active-passive devices featuring wrinkled copper active layers and permalloy passive layers capture 2.8 μm magnetic particles upon the application of a 35 mA current.
Photonic bandgap narrowing in conical hollow core Bragg fibers
Authors: Ozturk Fahri Emre , Yildirim Adem , Kanik Mehmet , Bayindir Mehmet
Published: August 2014

We report the photonic bandgap engineering of Bragg fibers by controlling the thickness profile of the fiber during the thermal drawing. Conical hollow core Bragg fibers were produced by thermal drawing under a rapidly alternating load, which was applied by introducing steep changes to the fiber drawing speed. In conventional cylindrical Bragg fibers, light is guided by omnidirectional reflections from interior dielectric mirrors with a single quarter wave stack period. In conical fibers, the diameter reduction introduced a gradient of the quarter wave stack period along the length of the fiber. Therefore, the light guided within the fiber encountered slightly smaller dielectric layer thicknesses at each reflection, resulting in a progressive blueshift of the reflectance spectrum. As the reflectance spectrum shifts, longer wavelengths of the initial bandgap cease to be omnidirectionally reflected and exit through the cladding, which narrows the photonic bandgap. A narrow transmission bandwidth is particularly desirable in hollow waveguide mid-infrared sensing schemes, where broadband light is coupled to the fiber and the analyte vapor is introduced into the hollow core to measure infrared absorption. We carried out sensing simulations using the absorption spectrum of isopropyl alcohol vapor to demonstrate the importance of narrow bandgap fibers in chemical sensing applications.
Improvement of magnetic and structural stabilities in high-quality Co2FeSi1−xAlx/Si heterointerfaces
Authors: Yamada S. , Tanikawa K. , Oki S. , Kawano M. , Miyao M. , Hamaya K.
Published: August 2014

We study high-quality Co2FeSi1−xAlx Heusler compound/Si (0 ≤ x ≤ 1) heterointerfaces for silicon (Si)-based spintronic applications. In thermal treatment conditions, the magnetic and structural stabilities of the Co2FeSi1−xAlx/Si heterointerfaces are improved with increasing x in Co2FeSi1−xAlx. Compared with L21-ordered Co2FeSi/Si, B2-ordered Co2FeAl/Si can suppress the diffusion of Si atoms into the Heusler-compound structure. This experimental study will provide an important knowledge for applications in Si-based spin transistors with metallic source/drain contacts.
Switchable wavelength-selective and diffuse metamaterial absorber/emitter with a phase transition spacer layer
Authors: Wang Hao , Yang Yue , Wang Liping
Published: August 2014

We numerically demonstrate a switchable metamaterial absorber/emitter by thermally turning on or off the excitation of magnetic resonance upon the phase transition of vanadium dioxide (VO2). Perfect absorption peak exists around the wavelength of 5 μm when the excitation of magnetic resonance is supported with the insulating VO2 spacer layer. The wavelength-selective absorption is switched off when the magnetic resonance is disabled with metallic VO2 that shorts the top and bottom metallic structures. The resonance wavelength can be tuned with different geometry, and the switchable metamaterial exhibits diffuse behaviors at oblique angles. The results would facilitate the design of switchable metamaterials for active control in energy and sensing applications.
Condensations of single DNA molecules induced by heptaplatin and its chiral isomer
Authors: Zhang Hong-Yan , Liu Yu-Ru , Li Wei , Li Hui , Dou Shuo-Xing , Xie Ping , Wang Wei-Chi , Wang Peng-Ye
Published: August 2014

Heptaplatin is a third-generation platinum antitumor drug. It has a chiral isomer. We studied the interactions between the two isomers and DNA by using magnetic tweezers and atomic force microscopy (AFM) to investigate the effect of chiralities of the isomers on the interactions. We found that the extension curves and average condensation rates of DNA molecules incubated with heptaplatin were nearly the same as those incubated with its chiral isomer. In addition, the structures of DNA molecules incubated with heptaplatin were also similar to those incubated with its chiral isomer. These results indicate the difference in chirality of the two isomers does not induce different interactions of the isomers with DNA. Our study may facilitate the understanding of interactions of platinum complexes with DNA and the design of new antitumor platinum complexes.
Photoperiodic variations induce shifts in the leaf metabolic profile of Chrysanthemum morifolium
Authors: Kjaer Katrine Heinsvig , Clausen Morten Rahr , Sundekilde Ulrik Kræmer , Petersen Bent Ole , Bertram Hanne Christine , Ottosen Carl-Otto
Published: August 2014

Plants have a high ability to adjust their metabolism, growth and development to changes in the light environment and to photoperiodic variation, but the current knowledge on how changes in metabolite contents are associated with growth and development is limited. We investigated the effect of three different photoperiodic treatments with similar daily light integral (DLI) on the growth responses and diurnal patterns in detected leaf metabolites in the short day plant Chrysanthemum × morifolium Ramat. Treatments were long day (LD, 18 h light/6 h dark), short day (SD, 12 h light/12 h dark) and short day with irregular night interruptions (NI-SD,12 h light/12 h dark, applied in a weekly pattern, shifting from day-to-day). Photoperiodic variation resulted in changes in the phenotypic development of the plants. The plants grown in the SD treatment started to initiate reproductive development of the meristems and a decrease in leaf expansion resulted in lower leaf area of expanding leaves. In contrast, plants in the NI-SD and LD treatments did not show reproductive development at any stage and final leaf area of the expanding leaves was intermediate for the NI-SD plants and largest for the LD plants. Photoperiodic variation also resulted in changes in the leaf metabolic profile for most of the analysed metabolites, but only carbohydrates, citrate and some amino acids displayed a shift in their diurnal pattern. Further, our results illustrated that short days (SD) increased the diurnal turnover of 1-kestose after 2 weeks, and decreased the overall contents of leaf hexoses after 3 weeks. In the two other treatments a diurnal turnover of 1-kestose was not stimulated before after 3 weeks, and hexoses together with the hexose : sucrose ratio steadily increased during the experiment. Our results enlighten the plasticity of leaf growth and metabolism to environmental changes, and demonstrate that diurnally regulated metabolites not always respond to photoperiodic variation.
Endothelial cell FGF signaling is required for injury response but not for vascular homeostasis
Authors: Oladipupo Sunday S. , Smith Craig , Santeford Andrea , Park Changwon , Sene Abdoulaye , Wiley Luke A. , Osei-Owusu Patrick , Hsu Joann , Zapata Nicole , Liu Fang , Nakamura Rei , Lavine Kory J. , Blumer Kendall J. , Choi Kyunghee , Apte Rajendra S. , Ornitz David M.
Published: August 2014

Significance

FGF receptor (FGFR) signaling is thought to be essential for vascular development, homeostasis, and pathological angiogenesis. However, the in vivo requirements and the cellular targets of FGF in the vasculature are not known. Here, we show that endothelial FGFR1 and FGFR2 are not required for vascular homeostasis or physiological functions and are likely not required for embryonic development. However, endothelial FGFR1 and FGFR2 are essential for neovascularization after skin or eye injury or following retinal ischemia. These findings reveal a key requirement for cell-autonomous endothelial FGFR signaling in tissue repair and neovascularization following injury and validate the endothelial cell FGFR as a target for diseases associated with aberrant vascular proliferation such as age-related macular degeneration, diabetic retinopathy, and wound healing.
Comparative assembly hubs: Web-accessible browsers for comparative genomics
Authors: Nguyen Ngan , Hickey Glenn , Raney Brian J. , Armstrong Joel , Clawson Hiram , Zweig Ann , Karolchik Donna , Kent William James , Haussler David , Paten Benedict
Published: August 2014

Motivation: Researchers now have access to large volumes of genome sequences for comparative analysis, some generated by the plethora of public sequencing projects and, increasingly, from individual efforts. It is not possible, or necessarily desirable, that the public genome browsers attempt to curate all these data. Instead, a wealth of powerful tools is emerging to empower users to create their own visualizations and browsers.

Results: We introduce a pipeline to easily generate collections of Web-accessible UCSC Genome Browsers interrelated by an alignment. It is intended to democratize our comparative genomic browser resources, serving the broad and growing community of evolutionary genomicists and facilitating easy public sharing via the Internet. Using the alignment, all annotations and the alignment itself can be efficiently viewed with reference to any genome in the collection, symmetrically. A new, intelligently scaled alignment display makes it simple to view all changes between the genomes at all levels of resolution, from substitutions to complex structural rearrangements, including duplications. To demonstrate this work, we create a comparative assembly hub containing 57 Escherichia coli and 9 Shigella genomes and show examples that highlight their unique biology.

Availability and implementation: The source code is available as open source at: https://github.com/glennhickey/progressiveCactus The E.coli and Shigella genome hub is now a public hub listed on the UCSC browser public hubs Web page.

Contact:  benedict@soe.ucsc.edu

Supplementary information:  Supplementary data are available at Bioinformatics online.
Comparison of Sapwood Discoloration in Fagaceae Trees After Inoculation with Isolates of Raffaelea quercivora, Cause of Mass Mortality of Japanese Oak Trees
Authors: Kusumoto Dai , Masuya Hayato , Hirao Toshihide , Goto Hideaki , Hamaguchi Keiko , Chou Wen-I , Suasa-ard Wiwat , Buranapanichpan Sawai , Uraichuen Sopon , Kern-asa Oraphan , Sanguansub Sunisa , Panmongkol Aumporn , Pham Quang Thu , Kahono Sih , Sudiana I Made , Kamata Naoto
Published: August 2014

The mass mortality of oak trees has been prevalent in Japan since the late 1980s. The fungus Raffaelea quercivora is transmitted by an ambrosia beetle, Platypus quercivorus, which causes mortality. The beetle is able to bore galleries into the sapwood of most Fagaceae trees in Japan; however, the level of mortality caused by R. quercivora and P. quercivorus differs greatly among tree species. Previous studies by our research group have demonstrated that the virulence of R. quercivora differs among isolates when inoculated into Quercus serrata logs. However, interactions between the virulence of R. quercivora isolates and the susceptibility of other fagaceous species have yet to be elucidated. In this study, we inoculated the fresh logs of 11 fagaceous species with isolates of low and high virulence, and measured the tangential widths of discolored sapwoods 3 weeks after inoculation. Although the discoloration widths of Q. crispula sapwood were similar among all isolates, those of Q. serrata and Q. acutissima tended to increase with the more virulent isolates. Sapwood discoloration in Q. glauca, Q. acuta, Q. salicina, Lethocarpus edulis, and Castanopsis sieboldii was greatly increased by highly virulent isolates. Discoloration in Fagus japonica was not influenced by any of the isolates. The logs of Q. crispula and Q. serrata but not Q. glauca were significantly more discolored by a low-virulence isolate compared with standing trees. The various virulent isolates induced unique sapwood discoloration characteristics in each species, which may explain species-specific differences in mortality rates.
Potential Effects of Diurnal Temperature Oscillations on Potato Late Blight with Special Reference to Climate Change
Authors: Shakya S. K. , Goss E. M. , Dufault N. S. , van Bruggen A. H. C.
Published: August 2014

Global climate change will have effects on diurnal temperature oscillations as well as on average temperatures. Studies on potato late blight (Phytophthora infestans) development have not considered daily temperature oscillations. We hypothesize that growth and development rates of P. infestans would be less influenced by change in average temperature as the magnitude of fluctuations in daily temperatures increases. We investigated the effects of seven constant (10, 12, 15, 17, 20, 23, and 27°C) and diurnally oscillating (±5 and ±10°C) temperatures around the same means on number of lesions, incubation period, latent period, radial lesion growth rate, and sporulation intensity on detached potato leaves inoculated with two P. infestans isolates from clonal lineages US-8 and US-23. A four-parameter thermodynamic model was used to describe relationships between temperature and disease development measurements. Incubation and latency progression accelerated with increasing oscillations at low mean temperatures but slowed down with increasing oscillations at high mean temperatures (P < 0.005), as hypothesized. Infection efficiency, lesion growth rate, and sporulation increased under small temperature oscillations compared with constant temperatures but decreased when temperature oscillations were large. Thus, diurnal amplitude in temperature should be considered in models of potato late blight, particularly when predicting effects of global climate change on disease development.
Gripping during climbing of arboreal snakes may be safe but not economical
Authors: Byrnes Greg , Jayne Bruce C.
Published: August 2014

On the steep surfaces that are common in arboreal environments, many types of animals without claws or adhesive structures must use muscular force to generate sufficient normal force to prevent slipping and climb successfully. Unlike many limbed arboreal animals that have discrete gripping regions on the feet, the elongate bodies of snakes allow for considerable modulation of both the size and orientation of the gripping region. We quantified the gripping forces of snakes climbing a vertical cylinder to determine the extent to which their force production favoured economy or safety. Our sample included four boid species and one colubrid. Nearly all of the gripping forces that we observed for each snake exceeded our estimate of the minimum required, and snakes commonly produced more than three times the normal force required to support their body weight. This suggests that a large safety factor to avoid slipping and falling is more important than locomotor economy.
Paul Moritz Cohn. 8 January 1924 — 20 April 2006
Authors: Bergman George , Stuart Trevor
Published: August 2014

Paul Cohn was born in Hamburg, where he lived until he was 15 years of age. However, in 1939, after the rise of the Nazis and the growing persecution of the Jews, his parents, James and Julia Cohn, sent him to England by Kindertransport. They remained behind and Paul never saw them again; they perished in concentration camps. In England, being only 15 years old, he was directed to work first on a chicken farm but later as a fitter in a London factory. His academic talents became clear and he was encouraged by the refugee committee in Dorking and by others to continue his education by studying for the English School Certificate Examinations to sit the Cambridge Entrance Examination. He was awarded an Exhibition to study mathematics at Trinity College. After receiving his PhD in 1951, Paul Cohn went from strength to strength in algebra and not only became a world leader in non-commutative ring theory but also made important contributions to group theory, Lie rings and semigroups. He was much admired, and he travelled widely to collaborate with other algebraists. Moreover, he was a great supporter of the London Mathematical Society, serving as its President from 1982 to 1984.
Pattern selection and hysteresis in the Rietkerk model for banded vegetation in semi-arid environments
Authors: Dagbovie Ayawoa S. , Sherratt Jonathan A.
Published: August 2014

Banded vegetation is a characteristic feature of semi-arid environments. It occurs on gentle slopes, with alternating stripes of vegetation and bare ground running parallel to the contours. A number of mathematical models have been proposed to investigate the mechanisms underlying these patterns, and how they might be affected by changes in environmental conditions. One of the most widely used models is due to Rietkerk and co-workers, and is based on a water redistribution hypothesis, with the key feedback being that the rate of rainwater infiltration into the soil is an increasing function of plant biomass. Here, for the first time, we present a detailed study of the existence and stability of pattern solutions of the Rietkerk model on slopes, using the software packagewavetrain(www.ma.hw.ac.uk/wavetrain). Specifically, we calculate the region of the rainfall–migration speed parameter plane in which patterns exist, and the sub-region in which these patterns are stable as solutions of the model partial differential equations. We then perform a detailed simulation-based study of the way in which patterns evolve when the rainfall parameter is slowly varied. This reveals complex behaviour, with sudden jumps in pattern wavelength, and hysteresis; we show that these jumps occur when the contours of constant pattern wavelength leave the parameter region giving stable patterns. Finally, we extend our results to the case in which a diffusion term for surface water is added to the model equations. The parameter regions for pattern existence and stability are relatively insensitive to small or moderate levels of surface water diffusion, but larger diffusion coefficients significantly change the subdivision into stable and unstable patterns.
Progressive promoter element combinations classify conserved orthogonal plant circadian gene expression modules
Authors: Smieszek Sandra P. , Yang Haixuan , Paccanaro Alberto , Devlin Paul F.
Published: August 2014

We aimed to test the proposal that progressive combinations of multiple promoter elements acting in concert may be responsible for the full range of phases observed in plant circadian output genes. In order to allow reliable selection of informative phase groupings of genes for our purpose, intrinsic cyclic patterns of expression were identified using a novel, non-biased method for the identification of circadian genes. Our non-biased approach identified two dominant, inherent orthogonal circadian trends underlying publicly available microarray data from plants maintained under constant conditions. Furthermore, these trends were highly conserved across several plant species. Four phase-specific modules of circadian genes were generated by projection onto these trends and, in order to identify potential combinatorial promoter elements that might classify genes into these groups, we used a Random Forest pipeline which merged data from multiple decision trees to look for the presence of element combinations. We identified a number of regulatory motifs which aggregated into coherent clusters capable of predicting the inclusion of genes within each phase module with very high fidelity and these motif combinations changed in a consistent, progressive manner from one phase module group to the next, providing strong support for our hypothesis.
Theory and data for simulating fine-scale human movement in an urban environment
Authors: Perkins T. Alex , Garcia Andres J. , Paz-Soldán Valerie A. , Stoddard Steven T. , Reiner Robert C. , Vazquez-Prokopec Gonzalo , Bisanzio Donal , Morrison Amy C. , Halsey Eric S. , Kochel Tadeusz J. , Smith David L. , Kitron Uriel , Scott Thomas W. , Tatem Andrew J.
Published: August 2014

Individual-based models of infectious disease transmission depend on accurate quantification of fine-scale patterns of human movement. Existing models of movement either pertain to overly coarse scales, simulate some aspects of movement but not others, or were designed specifically for populations in developed countries. Here, we propose a generalizable framework for simulating the locations that an individual visits, time allocation across those locations, and population-level variation therein. As a case study, we fit alternative models for each of five aspects of movement (number, distance from home and types of locations visited; frequency and duration of visits) to interview data from 157 residents of the city of Iquitos, Peru. Comparison of alternative models showed that location type and distance from home were significant determinants of the locations that individuals visited and how much time they spent there. We also found that for most locations, residents of two neighbourhoods displayed indistinguishable preferences for visiting locations at various distances, despite differing distributions of locations around those neighbourhoods. Finally, simulated patterns of time allocation matched the interview data in a number of ways, suggesting that our framework constitutes a sound basis for simulating fine-scale movement and for investigating factors that influence it.
Mapping the stereotyped behaviour of freely moving fruit flies
Authors: Berman Gordon J. , Choi Daniel M. , Bialek William , Shaevitz Joshua W.
Published: August 2014

A frequent assumption in behavioural science is that most of an animal's activities can be described in terms of a small set of stereotyped motifs. Here, we introduce a method for mapping an animal's actions, relying only upon the underlying structure of postural movement data to organize and classify behaviours. Applying this method to the ground-based behaviour of the fruit fly,Drosophila melanogaster, we find that flies perform stereotyped actions roughly 50% of the time, discovering over 100 distinguishable, stereotyped behavioural states. These include multiple modes of locomotion and grooming. We use the resulting measurements as the basis for identifying subtle sex-specific behavioural differences and revealing the low-dimensional nature of animal motions.
Actin flow and talin dynamics govern rigidity sensing in actin–integrin linkage through talin extension
Authors: Hirata Hiroaki , Chiam Keng-Hwee , Lim Chwee Teck , Sokabe Masahiro
Published: August 2014

At cell–substrate adhesion sites, the linkage between actin filaments and integrin is regulated by mechanical stiffness of the substrate. Of potential molecular regulators, the linker proteins talin and vinculin are of particular interest because mechanical extension of talin induces vinculin binding with talin, which reinforces the actin–integrin linkage. For understanding the molecular and biophysical mechanism of rigidity sensing at cell–substrate adhesion sites, we constructed a simple physical model to examine a role of talin extension in the stiffness-dependent regulation of actin–integrin linkage. We show that talin molecules linking between retrograding actin filaments and substrate-bound integrin are extended in a manner dependent on substrate stiffness. The model predicts that, in adhesion complexes containing ≈30 talin links, talin is extended enough for vinculin binding when the substrate is stiffer than 1 kPa. The lifetime of talin links needs to be 2–5 s to achieve an appropriate response of talin extension against substrate stiffness. Furthermore, changes in actin velocity drastically shift the range of substrate stiffness that induces talin–vinculin binding. Our results suggest that talin extension is a key step in sensing and responding to substrate stiffness at cell adhesion sites.
Leonardo da Vinci and the origin of semen
Authors: Noble Denis , DiFrancesco Dario , Zancani Diego
Published: August 2014

It is well known that Leonardo da Vinci made several drawings of the human male anatomy. The early drawings (before 1500) were incorrect in identifying the origin of semen, where he followed accepted teaching of his time. It is widely thought that he did not correct this mistake, a view that is reflected in several biographies. In fact, he made a later drawing (after 1500) in which the description of the anatomy is remarkably accurate and must have been based on careful dissection. In addition to highlighting this fact, acknowledged previously in only one other source, this article reviews the background to Leonardo's knowledge of the relevant anatomy.
Nonlinear bending models for beams and plates
Authors: Antipov Y. A.
Published: August 2014

A new nonlinear model for large deflections of a beam is proposed. It comprises the Euler–Bernoulli boundary value problem for the deflection and a nonlinear integral condition. When bending does not alter the beam length, this condition guarantees that the deflected beam has the original length and fixes the horizontal displacement of the free end. The numerical results are in good agreement with the ones provided by the elastica model. Dynamic and two-dimensional generalizations of this nonlinear one-dimensional static model are also discussed. The model problem for an inextensible rectangular Kirchhoff plate, when one side is clamped, the opposite one is subjected to a shear force, and the others are free of moments and forces, is reduced to a singular integral equation with two fixed singularities. The singularities of the unknown function are examined, and a series-form solution is derived by the collocation method in terms of the associated Jacobi polynomials. The procedure requires solving an infinite system of linear algebraic equations for the expansion coefficients subject to the inextensibility condition.
Optimal fine-scale structures in compliance minimization for a uniaxial load
Authors: Kohn Robert V. , Wirth Benedikt
Published: August 2014

We consider the optimization of the topology and geometry of an elastic structureO⊂R2subjected to a fixed boundary load, i.e. we aim to minimize a weighted sum of material volumeVol(O), structure perimeterPer(O)and structure complianceComp(O)(which is the work done by the load). As a first simple and instructive case, this paper treats the situation of an imposed uniform uniaxial tension load in two dimensions. If the weightεof the perimeter is small, optimal geometries exhibit very fine-scale structure which cannot be resolved by numerical optimization. Instead, we prove how the minimum energy scales inε, which involves the construction of a family of near-optimal geometries and thus provides qualitative insights. The construction is based on a classical branching procedure with some features unique to compliance minimization. The proof of the energy scaling also requires an ansatz-independent lower bound, which we derive once via a classical convex duality argument (which is restricted to two dimensions and the uniaxial load) and once via a Fourier-based refinement of the Hashin–Shtrikman bounds for the effective elastic moduli of composite materials. We also highlight the close relation to and the differences from shape optimization with a scalar PDE-constraint and a link to the pattern formation observed in intermediate states of type-I superconductors.
Stress-induced mutagenesis and complex adaptation
Authors: Ram Yoav , Hadany Lilach
Published: August 2014

Because mutations are mostly deleterious, mutation rates should be reduced by natural selection. However, mutations also provide the raw material for adaptation. Therefore, evolutionary theory suggests that the mutation rate must balance betweenadaptability—the ability to adapt—andadaptedness—the ability to remain adapted. We model an asexual population crossing a fitness valley and analyse the rate of complex adaptation with and without stress-induced mutagenesis (SIM)—the increase of mutation rates in response to stress or maladaptation. We show that SIM increases the rate of complex adaptation without reducing the population mean fitness, thus breaking the evolutionary trade-off betweenadaptabilityandadaptedness. Our theoretical results support the hypothesis that SIM promotes adaptation and provide quantitative predictions of the rate of complex adaptation with different mutational strategies.
Starvation reveals the cause of infection-induced castration and gigantism
Authors: Cressler Clayton E. , Nelson William A. , Day Troy , McCauley Edward
Published: August 2014

Parasites often induce life-history changes in their hosts. In many cases, these infection-induced life-history changes are driven by changes in the pattern of energy allocation and utilization within the host. Because these processes will affect both host and parasite fitness, it can be challenging to determine who benefits from them. Determining the causes and consequences of infection-induced life-history changes requires the ability to experimentally manipulate life history and a framework for connecting life history to host and parasite fitness. Here, we combine a novel starvation manipulation with energy budget models to provide new insights into castration and gigantism in the
Daphnia magna
–
Pasteuria ramosa
host–parasite system. Our results show that starvation primarily affects investment in reproduction, and increasing starvation stress reduces gigantism and parasite fitness without affecting castration. These results are consistent with an energetic structure where the parasite uses growth energy as a resource. This finding gives us new understanding of the role of castration and gigantism in this system, and how life-history variation will affect infection outcome and epidemiological dynamics. The approach of combining targeted life-history manipulations with energy budget models can be adapted to understand life-history changes in other disease systems.
Animal vocal sequences: not the Markov chains we thought they were
Authors: Kershenbaum Arik , Bowles Ann E. , Freeberg Todd M. , Jin Dezhe Z. , Lameira Adriano R. , Bohn Kirsten
Published: August 2014

Many animals produce vocal sequences that appear complex. Most researchers assume that these sequences are well characterized as Markov chains (i.e. that the probability of a particular vocal element can be calculated from the history of only a finite number of preceding elements). However, this assumption has never been explicitly tested. Furthermore, it is unclear how language could evolve in a single step from a Markovian origin, as is frequently assumed, as no intermediate forms have been found between animal communication and human language. Here, we assess whether animal taxa produce vocal sequences that are better described by Markov chains, or by non-Markovian dynamics such as the ‘renewal process’ (RP), characterized by a strong tendency to repeat elements. We examined vocal sequences of seven taxa: Bengalese finchesLonchura striata domestica, Carolina chickadeesPoecile carolinensis, free-tailed batsTadarida brasiliensis, rock hyraxesProcavia capensis, pilot whalesGlobicephala macrorhynchus, killer whalesOrcinus orcaand orangutansPongospp.The vocal systems of most of these species are more consistent with a non-Markovian RP than with the Markovian models traditionally assumed. Our data suggest that non-Markovian vocal sequences may be more common than Markov sequences, which must be taken into account when evaluating alternative hypotheses for the evolution of signalling complexity, and perhaps human language origins.
Cooperation and conflict: field experiments in Northern Ireland
Authors: Silva Antonio S. , Mace Ruth
Published: August 2014

The idea that cohesive groups, in which individuals help each other, have a competitive advantage over groups composed of selfish individuals has been widely suggested as an explanation for the evolution of cooperation in humans. Recent theoretical models propose the coevolution of parochial altruism and intergroup conflict, when in-group altruism and out-group hostility contribute to the group's success in these conflicts. However, the few empirical attempts to test this hypothesis do not use natural groups and conflate measures of in-group and unbiased cooperative behaviour. We conducted field experiments based on naturalistic measures of cooperation (school/charity donations and lost letters' returns) with two religious groups with an on-going history of conflict—Catholics and Protestants in Northern Ireland. Conflict was associated with reduced donations to out-group schools and the return of out-group letters, but we found no evidence that it influences in-group cooperation. Rather, socio-economic status was the major determinant of cooperative behaviour. Our study presents a challenge to dominant perspectives on the origins of human cooperation, and has implications for initiatives aiming to promote conflict resolution and social cohesion.
The genomic landscape of polymorphic human nuclear mitochondrial insertions
Authors: Dayama Gargi , Emery Sarah B. , Kidd Jeffrey M. , Mills Ryan E.
Published: August 2014

The transfer of mitochondrial genetic material into the nuclear genomes of eukaryotes is a well-established phenomenon. Many studies over the past decade have utilized reference genome sequences of numerous species to characterize the prevalence and contribution of nuclear mitochondrial insertions to human diseases. The recent advancement of high throughput sequencing technologies has enabled the interrogation of genomic variation at a much finer scale, and now allows for an exploration into the diversity of polymorphic nuclear mitochondrial insertions (NumtS) in human populations. We have developed an approach to discover and genotype previously undiscovered Numt insertions using whole genome, paired-end sequencing data. We have applied this method to almost a thousand individuals in twenty populations from the 1000 Genomes Project and other data sets and identified 138 novel sites of Numt insertions, extending our current knowledge of existing Numt locations in the human genome by almost 20%. Most of the newly identified NumtS were found in less than 1% of the samples we examined, suggesting that they occur infrequently in nature or have been rapidly removed by purifying selection. We find that recent Numt insertions are derived from throughout the mitochondrial genome, including the D-loop, and have integration biases consistent with previous studies on older, fixed NumtS in the reference genome. We have further determined the complete inserted sequence for a subset of these events to define their age and origin of insertion as well as their potential impact on studies of mitochondrial heteroplasmy.
Linkages between investment flows and financial development
Authors: A. Asongu Simplice
Published: August 2014

Purpose

– The purpose of this paper is to introduce previously missing financial components (efficiency, activity and size) in the assessment of the finance-investment nexus.

Design/methodology/approach

– Vector autoregressive models in the perspectives of Vector Error Correction Model and short-run Granger causality are employed. There is usage of optimally specified econometric methods as opposed to purely discretionary model specifications in mainstream literature.

Findings

– Three main findings are established: first, while finance led investment elasticities are positive, investment elasticities of finance are negative; second, but for Guinea Bissau, Mozambique and Togo, finance does not seem to engender portfolio investment; and finally, contrary to mainstream literature, financial efficiency appears to impact investment more than financial depth.

Practical implications

– Four policy implications result: first, extreme caution is needed in the use of single equation analysis for economic forecasts; second, financial development leads more to investment flows than the other way round; third, financial allocation efficiency is more relevant as means to attracting investment flows than financial depth; and finally, the somewhat heterogeneous character of the findings also point to shortcomings in blanket policies that are not contingent on country-specific trends in the finance-investment nexus.

Originality/value

– First, contrary to the mainstream approach we use four measures of financial intermediary development (depth, efficiency, activity and size) as well as four types of investment flows (domestic, foreign, portfolio and total). Second, the chosen investment and financial indicators are derived upon preliminary robust correlation analyses from the broadest macroeconomic data set available on investment and financial intermediary flows.
Importance of satisfaction with food for older adults’ quality of life
Authors: Jeong Jihye , Seo Sunhee
Published: August 2014

Purpose

– The purpose of this paper is to examine the relationships among satisfaction with food-related life (SWFL), perceived foodservice quality, and quality of life for older adults.

Design/methodology/approach

– A survey done using face-to-face interviews of older adults residing in long-term care facilities. A total of 238 older adults participated in this study.

Findings

– The results showed that perceived foodservice quality had a strong association with SWFL; SWFL had a significant positive association with quality of life; perceived foodservice quality positively related to quality of life. Increased SWFL would improve quality of older adults.

Research limitations/implications

– This study has limitations related to convenience sample. Different sampling could help with generalization of results.

Practical implications

– Foodservice managers in long-term care facilitates should try to maximize food and service qualities for residents because improving food and service quality improves their quality of life. For example, offering a variety of menus to allow older adults to enjoy food and improve their SWFL.

Originality/value

– This study emphasized that food was important to older adults and helped determine quality of life for them. SWFL was rarely empirically examined in the previous research.
Can increased organic consumption mitigate climate changes?
Authors: Ravn Heerwagen Lennart , Mørch Andersen Laura , Christensen Tove , Sandøe Peter
Published: August 2014

Purpose

– The purpose of this paper is to investigate the evidence for a positive correlation between increased consumption of organic products and potential climate change mitigation via decreased consumption of meat and it is discussed to what extent organic consumption is motivated by climate change concerns.

Design/methodology/approach

– A fixed effects model together with a factor analysis and ordinary least square are used to analyse household purchase data for 2,000 households in 2006-2010 combined with survey questionnaire data from 2008.

Findings

– A small but statistically significant correlation between increasing organic budget shares and decreasing meat budget shares is found. People include food-related behaviour such as the purchase of organic food and reduced meat consumption as ways to mitigate climate change. However, other behavioural modifications such as reduction of car usage and household heating are perceived as more important strategies.

Research limitations/implications

– Other food-related mitigation strategies could be investigated. The climate effect of different diets – and how to motivate consumers to pursue them – could be investigated. Individual as opposed to household data would supplement the analyses.

Practical implications

– Demand-side policies aiming at climate-friendly consumption could be a central factor in combating climate change. Already, food-related mitigation strategies such as lowered meat consumption are established practices among a group of organic consumers. As some consumers believe that climate change can be mitigated by consuming organic food, the authors propose that this is taken into account in the development of organic farming.

Originality/value

– The authors propose a shift from analysing the climate-friendliness of production to addressing the climate-friendliness of consumption using consumption of organic food as a case. The authors link stated concerns for climate changes with actual food-related behaviour.
Effect of low glycaemic index diets on satiety
Authors: Maria de Medeiros Batista Sonia , Addison Machado Moreira Emilia , Medeiros Rataichesck Fiates Giovanna , Alice Altemburg de Assis Maria , Teixeira Evanilda
Published: August 2014

Purpose

– The purpose of the paper is to determine the effects of a hypocaloric diet with a low-glycaemic index (GI) on weight loss and postprandial blood glucose and assess both the satiety and palatability of the diet.

Design/methodology/approach

– A clinical trial was conducted with ten women (mean age: 38.8±11.3 years; body mass index: 27.2±3.5 kg/m2) submitted to a hypocaloric diet, assessments were performed at baseline and after seven days of treatment.

Findings

– Significant reductions were found in body weight (1.1±0.7 kg; p=0.001), triccipital skinfold (2.87±3.24 mm; p=0.021) and waist circumference (3.6±4.8 cm; p=0.041). Mean fasting and postprandial blood glucose values were 88.7±6.1 mg/dL and 91.6±9.6 mg/dL, respectively. Responses regarding satiety and palatability of the low-GI diet were predominantly “extremely satisfied” and “I liked it very much,” respectively, for all meals and throughout all seven days of the study.

Originality/value

– The present study demonstrated the benefits of a low-GI diet with regard to weight loss, blood glucose control and satiety. The diet proved to be palatable, which could favor compliance with long-term treatment.
Attitudes towards genetically modified animals in food production
Authors: J. Frewer Lynn , Coles David , Houdebine Louis-Marie , A. Kleter Gijs
Published: August 2014

Purpose

– Food products developed using genetically modified (GM) animals may soon be introduced in Europe and beyond. Their successful commercialisation depends on consumer acceptance, and so it is timely to review the existing literature in this respect. The paper aims to discuss these issues.

Design/methodology/approach

– A systematic review identified 42 English language peer reviewed papers assessing public opinion of GM animals associated with food production. Thematic analysis was applied to the results to identify and explain consumer attitudes.

Findings

– Publication peaked in 2004, and declined thereafter. European consumers were less accepting of GM animal technology than the US and Asian consumers, although the latter reported more ethical concern. Risk and benefit perceptions, ethical concerns (e.g. related to animal welfare) may explain negative consumer attitudes towards animals in food production.

Research limitations/implications

– There is a lack of data on consumer attitudes to GM animals applied to food production, in particular in relation to consumers in emerging economies and developing countries. This is problematic as applications of GM animal products are about to enter the market.

Practical implications

– There is a need to track changes in public opinion as GM food production animals are further developed. The introduction and commercialisation of applications with specific characteristics may further shape consumer attitudes.

Social implications

– Methods need to be developed to involve consumers and other stakeholders in shaping future applications of agri-food applications of GM animals.

Originality/value

– The review collates existing quantitative and qualitative knowledge regarding the drivers of consumer attitudes towards GM animals used in food production using systematic review methodology.
The role of formal industry clusters in the internationalization of new ventures
Authors: Colovic Ana , Lamotte Olivier
Published: August 2014

Purpose

– The purpose of this study is to investigate the internationalization of international new ventures (INVs). Specifically, this research explores the ways in which a formal cluster can facilitate the internationalization process of these firms.

Design/methodology/approach

– The authors studied how four INVs benefitted from the actions of two clusters in France – Systematic and Mov’eo – as they internationalized. They conducted semi-structured interviews with the CEOs and other representatives of the INVs and with the members of the cluster management teams.

Findings

– The findings indicate that clusters can facilitate the internationalization of INVs by providing resources, networking opportunities and legitimacy to help them reach global markets and by increasing the speed of internationalization.

Originality/value

– By analyzing the specific role that a formal cluster plays in the internationalization of INVs, this research contributes to the literature examining the link between location and INV internationalization. The authors argue that the cluster’s role can be considered as that of an intermediary organization helping INVs to expand globally.