bluuebunny/crossref_metadata_2025 huggingface dataset:
Lift-drag and flow structures associated with the “clap and fling” motion
Authors: Arora Nipun , Gupta Amit , Sanghi Sanjeev , Aono Hikaru , Shyy Wei
Published: July 2014

The present study focuses on the analysis of the fluid dynamics associated with the flapping motion of finite-thickness wings. A two-dimensional numerical model for one and two-winged “clap and fling” stroke has been developed to probe the aerodynamics of insect flight. The influence of kinematic parameters such as the percentage overlap between translational and rotational phase ξ, the separation between two wings δ and Reynolds numbers Re on the evolvement of lift and drag has been investigated. In addition, the roles of the leading and trailing edge vortices on lift and drag in clap and fling type kinematics are highlighted. Based on a surrogate analysis, the overlap ratio ξ is identified as the most influential parameter in enhancing lift. On the other hand, with increase in separation δ, the reduction in drag is far more dominant than the decrease in lift. With an increase in Re (which ranges between 8 and 128), the mean drag coefficient decreases monotonously, whereas the mean lift coefficient decreases to a minimum and increases thereafter. This behavior of lift generation at higher Re was characterized by the “wing-wake interaction” mechanism which was absent at low Re.
Anomalous dynamics of binary colloidal mixtures over a potential barrier: Effect of depletion interaction
Authors: Anil Kumar A. V.
Published: July 2014

The dynamics of a binary colloidal mixture under the influence of an external potential barrier has been studied by molecular dynamics simulations. The attractive depletion interaction between the barrier and larger particles fastens the dynamics of the larger particles over the potential barrier. At low temperatures, depletion interactions cause the larger particles to diffuse faster than smaller particles, which is counterintuitive. The repulsive barrier leads the small particles to undergo an anomalous diffusion which resembles the dynamics of systems undergoing a glass transition, while the larger particles undergo normal diffusion even at very low temperature.
Solving the hard problem of Bertrand's paradox
Authors: Aerts Diederik , de Bianchi Massimiliano Sassoli
Published: July 2014

Bertrand's paradox is a famous problem of probability theory, pointing to a possible inconsistency in Laplace's principle of insufficient reason. In this article, we show that Bertrand's paradox contains two different problems: an “easy” problem and a “hard” problem. The easy problem can be solved by formulating Bertrand's question in sufficiently precise terms, so allowing for a non-ambiguous modelization of the entity subjected to the randomization. We then show that once the easy problem is settled, also the hard problem becomes solvable, provided Laplace's principle of insufficient reason is applied not to the outcomes of the experiment, but to the different possible “ways of selecting” an interaction between the entity under investigation and that producing the randomization. This consists in evaluating a huge average over all possible “ways of selecting” an interaction, which we call a universal average. Following a strategy similar to that used in the definition of the Wiener measure, we calculate such universal average and therefore solve the hard problem of Bertrand's paradox. The link between Bertrand's problem of probability theory and the measurement problem of quantum mechanics is also briefly discussed.
An in-flight radiography platform to measure hydrodynamic instability growth in inertial confinement fusion capsules at the National Ignition Facility
Authors: Raman K. S. , Smalyuk V. A. , Casey D. T. , Haan S. W. , Hoover D. E. , Hurricane O. A. , Kroll J. J. , Nikroo A. , Peterson J. L. , Remington B. A. , Robey H. F. , Clark D. S. , Hammel B. A. , Landen O. L. , Marinak M. M. , Munro D. H. , Peterson K. J. , Salmonson J.
Published: July 2014

A new in-flight radiography platform has been established at the National Ignition Facility (NIF) to measure Rayleigh–Taylor and Richtmyer–Meshkov instability growth in inertial confinement fusion capsules. The platform has been tested up to a convergence ratio of 4. An experimental campaign is underway to measure the growth of pre-imposed sinusoidal modulations of the capsule surface, as a function of wavelength, for a pair of ignition-relevant laser drives: a “low-foot” drive representative of what was fielded during the National Ignition Campaign (NIC) [Edwards et al., Phys. Plasmas 20, 070501 (2013)] and the new high-foot [Dittrich et al., Phys. Rev. Lett. 112, 055002 (2014); Park et al., Phys. Rev. Lett. 112, 055001 (2014)] pulse shape, for which the predicted instability growth is much lower. We present measurements of Legendre modes 30, 60, and 90 for the NIC-type, low-foot, drive, and modes 60 and 90 for the high-foot drive. The measured growth is consistent with model predictions, including much less growth for the high-foot drive, demonstrating the instability mitigation aspect of this new pulse shape. We present the design of the platform in detail and discuss the implications of the data it generates for the on-going ignition effort at NIF.
Deriving k·p parameters from full-Brillouin-zone descriptions: A finite-element envelope function model for quantum-confined wurtzite nanostructures
Authors: Zhou Xiangyu , Bertazzi Francesco , Goano Michele , Ghione Giovanni , Bellotti Enrico
Published: July 2014

We present a multiband envelope-function model for wurtzite nanostructures based on a rigorous numerical procedure to determine operator ordering and band parameters from nonlocal empirical pseudopotential calculations. The proposed approach, implemented within a finite-element scheme, leads to well-posed, numerically stable envelope equations that accurately reproduce full-Brillouin-zone subband dispersions of quantum systems. Although demonstrated here for III-nitride nonlocal empirical pseudopotentials, the model provides a general theoretical framework applicable to ab initio electronic structures of wurtzite semiconductors.
Spin-lattice relaxation within a dimerized Ising chain in a magnetic field
Authors: Erdem Rıza , Gülpınar Gül , Yalçın Orhan , Pawlak Andrzej
Published: July 2014

A qualitative study of the spin-lattice relaxation within a dimerized Ising chain in a magnetic field is presented. We have first determined the time dependence of the deviation of the lattice distortion parameter δΔ from the equilibrium state within framework of a technique combining the statistical equilibrium theory based on the transfer matrix method and the linear theory of irreversible thermodynamics. We have shown that the time dependence of the lattice distortion parameter is characterized by a single time constant (τ) which diverges around the critical point in both dimerized (Δ≠0) and uniform (Δ=0) phase regions. When the temperature and magnetic field are fixed to certain values, the time τ depends only on exchange coupling between the spins. It is a characteristic time associated with the long wavelength fluctuations of distortion. We have also taken into account the effects of spatial fluctuations on the relaxation time using the full Landau-Ginzburg free energy functional. We have found an explicit expression for the relaxation time as a function of temperature, coupling constant and wave vector (q) and shown that the critical mode corresponds to the case q=0. Finally, our results are found to be in good qualitative agreement with the results obtained in recent experimental study on synchrotron x-ray scattering and muon spin relaxation in diluted material Cu1−yMgyGeO3 where the composition y is very close to 0.0209. These results can be considered as natural extensions of some previous works on static aspects of the problem.
Nano-scale luminescence characterization of individual InGaN/GaN quantum wells stacked in a microcavity using scanning transmission electron microscope cathodoluminescence
Authors: Schmidt Gordon , Müller Marcus , Veit Peter , Bertram Frank , Christen Jürgen , Glauser Marlene , Carlin Jean-François , Cosendey Gatien , Butté Raphaël , Grandjean Nicolas
Published: July 2014

Using cathodoluminescence spectroscopy directly performed in a scanning transmission electron microscope at liquid helium temperatures, the optical and structural properties of a 62 InGaN/GaN multiple quantum well embedded in an AlInN/GaN based microcavity are investigated at the nanometer scale. We are able to spatially resolve a spectral redshift between the individual quantum wells towards the surface. Cathodoluminescence spectral linescans allow directly visualizing the critical layer thickness in the quantum well stack resulting in the onset of plastic relaxation of the strained InGaN/GaN system.
Realistic reflectance spectrum of thin films covering a transparent optically thick substrate
Authors: Cesaria M. , Caricato A. P. , Martino M.
Published: July 2014

A spectrophotometric strategy is presented and discussed for calculating realistically the reflectance spectrum of an absorbing film deposited over a thick transparent or semi-transparent substrate. The developed route exploits simple mathematics, has wide range of applicability (high-to-weak absorption regions and thick-to-ultrathin films), rules out numerical and curve-fitting procedures as well as model-functions, inherently accounts for the non-measurable contribution of the film-substrate interface as well as substrate backside, and describes the film reflectance spectrum as determined by the experimental situation (deposition approach and parameters). The reliability of the method is tested on films of a well-known material (indium tin oxide) by deliberately changing film thickness and structural quality through doping. Results are found consistent with usual information yielded by reflectance, its inherent relationship with scattering processes and contributions to the measured total reflectance.
Enhanced 1.53 μm emission of Er3+ ions in phosphate glass via energy transfer from Cu+ ions
Authors: Jiménez José A. , Sendova Mariana
Published: July 2014

Optimizing the efficiency of Er3+ emission in the near-infrared telecommunication window in glass matrices is currently a subject of great interest in photonics research. In this work, Cu+ ions are shown to be successfully stabilized at a high concentration in Er-containing phosphate glass by a single-step melt-quench method, and demonstrated to transfer energy to Er3+ thereby enhancing the near-infrared emission about 15 times. The spectroscopic data indicate an energy conversion process where Cu+ ions first absorb photons broadly around 360 nm and subsequently transfer energy from the Stokes-shifted emitting states to resonant Er3+ absorption transitions in the visible. Consequently, the Er3+ electronic excited states decay and the 4I3/2 metastable state is populated, leading to the enhanced emission at 1.53 μm. Monovalent copper ions are thus recognized as sensitizers of Er3+ ions, suggesting the potential of Cu+ co-doping for applications in the telecommunications, solar cells, and solid-state lasing realizable under broad band near-ultraviolet optical pumping.
Polycrystalline indium phosphide on silicon by indium assisted growth in hydride vapor phase epitaxy
Authors: Metaferia Wondwosen , Sun Yan-Ting , Pietralunga Silvia M. , Zani Maurizio , Tagliaferri Alberto , Lourdudoss Sebastian
Published: July 2014

Polycrystalline InP was grown on Si(001) and Si(111) substrates by using indium (In) metal as a starting material in hydride vapor phase epitaxy (HVPE) reactor. In metal was deposited on silicon substrates by thermal evaporation technique. The deposited In resulted in islands of different size and was found to be polycrystalline in nature. Different growth experiments of growing InP were performed, and the growth mechanism was investigated. Atomic force microscopy and scanning electron microscopy for morphological investigation, Scanning Auger microscopy for surface and compositional analyses, powder X-ray diffraction for crystallinity, and micro photoluminescence for optical quality assessment were conducted. It is shown that the growth starts first by phosphidisation of the In islands to InP followed by subsequent selective deposition of InP in HVPE regardless of the Si substrate orientation. Polycrystalline InP of large grain size is achieved and the growth rate as high as 21 μm/h is obtained on both substrates. Sulfur doping of the polycrystalline InP was investigated by growing alternating layers of sulfur doped and unintentionally doped InP for equal interval of time. These layers could be delineated by stain etching showing that enough amount of sulfur can be incorporated. Grains of large lateral dimension up to 3 μm polycrystalline InP on Si with good morphological and optical quality is obtained. The process is generic and it can also be applied for the growth of other polycrystalline III–V semiconductor layers on low cost and flexible substrates for solar cell applications.
Contact resonance force microscopy with higher-eigenmode for nanoscale viscoelasticity measurements
Authors: Zhou Xilong , Fu Ji , Miao Hongchen , Li Faxin
Published: July 2014

Nanoscale viscoelastic properties are essential for polymeric materials in their wide applications in nanotechnology. Here we proposed a contact resonance force microscopy (CRFM) method for viscoelasticity measurements by utilizing a cantilever's higher-eigenmode (n > 3). Numerical analysis results show that, compared to its lower eigenmodes, a cantilever's higher eigenmode is more sensitive to contact damping and less affected by contact stiffness variations. This tendency is then verified by nanoscale viscoelasticity mapping on a polystyrene (PS)/polymethyl methacrylate (PMMA) copolymer thin film using a compliant cantilever's different eigenmodes. Results show that higher-eigenmode CRFM can provide better imaging contrast and is thus suggested for viscoelasticity measurements.
Back bias induced dynamic and steep subthreshold swing in junctionless transistors
Authors: Parihar Mukta Singh , Kranti Abhinav
Published: July 2014

In this work, we analyze back bias induced steep and dynamic subthreshold swing in junctionless double gate transistors operated in the asymmetric mode. This impact ionization induced dynamic subthreshold swing is explained in terms of the ratio between minimum hole concentration and peak electron concentration, and the dynamic change in the location of the conduction channel with applied front gate voltage. The reason for the occurrence of impact ionization at sub-bandgap drain voltages in silicon junctionless transistors is also accounted for. The optimum junctionless transistor operating at a back gate bias of −0.9 V, achieves over 5 orders of change in drain current at a gate overdrive of 200 mV and drain bias of 1 V. These results for junctionless transistors are significantly better than those exhibited by silicon tunnel field effect transistors operating at the same drain bias.
Microlenses with tuned focal characteristics for optical wireless imaging
Authors: Jin Xian , Guerrero Daniel , Klukas Richard , Holzman Jonathan F.
Published: July 2014

Microlenses are fabricated and investigated for integrated imaging applications. The microlenses are fabricated by an in situ polymer electro-dispensing technique that enables user-controlled microlens sizes and shapes, by direct-dispensing and voltage-tuning with a metal micro-needle tip in a filler solution. Theoretical and experimental analyses are carried out for three limiting-cases of electro-dispensed microlenses: an acute-angle microlens with a 30° contact angle, a right-angle microlens with a 90° contact angle, and an obtuse-angle microlens with a 120° contact angle. It is found that the right-angle microlens, with a 500 μm diameter, yields an especially short focal length (700 μm) and exceedingly large numerical aperture (0.533). These characteristics can meet the needs of emerging applications, such as optical wireless devices, which demand compact device integration and broad field-of-view imaging. The microlenses are tested in optical wireless imaging receivers, for signal-to-noise ratio performance, and it is found that the right-angle microlens can offer significant (10 dB) performance enhancements.
Enhanced memory effect with embedded graphene nanoplatelets in ZnO charge trapping layer
Authors: El-Atab Nazek , Cimen Furkan , Alkis Sabri , Okyay Ali K. , Nayfeh Ammar
Published: July 2014

A charge trapping memory with graphene nanoplatelets embedded in atomic layer deposited ZnO (GNIZ) is demonstrated. The memory shows a large threshold voltage Vt shift (4 V) at low operating voltage (6/−6 V), good retention (>10 yr), and good endurance characteristic (>104 cycles). This memory performance is compared to control devices with graphene nanoplatelets (or ZnO) and a thicker tunnel oxide. These structures showed a reduced Vt shift and retention characteristic. The GNIZ structure allows for scaling down the tunnel oxide thickness along with improving the memory window and retention of data. The larger Vt shift indicates that the ZnO adds available trap states and enhances the emission and retention of charges. The charge emission mechanism in the memory structures with graphene nanoplatelets at an electric field E ≥ 5.57 MV/cm is found to be based on Fowler-Nordheim tunneling. The fabrication of this memory device is compatible with current semiconductor processing, therefore, has great potential in low-cost nano-memory applications.
Whole-tract dry matter and nitrogen digestibility of lactating dairy cows selected for phenotypic divergence in residual feed intake
Authors: Thornhill J. B. , Marett L. C. , Auldist M. J. , Greenwood J. S. , Pryce J. E. , Hayes B. J. , Wales W. J.
Published: July 2014

The objective of this experiment was to compare the whole-tract digestibility of dry matter (DM) and nitrogen (N) in Holstein-Friesian dairy cows selected for divergent feed conversion efficiency. The experiment used 16 primiparous Holstein–Friesian dairy cows selected based on their residual feed intake (RFI) measured as growing calves. The cows were housed in individual metabolism stalls and fed lucerne cubes ad libitum plus 6 kg DM per day of crushed wheat grain. Feed intake, milk yield, faecal and urine output were measured for 5 days. Rumen fluid was collected per os from each cow on one occasion. Milk production parameters and intakes of DM, organic matter, neutral detergent fibre, acid detergent fibre and N did not differ between RFI groups. Apparent whole-tract DM digestibility and N digestibility did not differ between RFI treatment groups. Rumen metabolites were also unaffected by RFI. In conclusion, divergence in RFI as calves was not associated with differences in whole-tract DM or N digestibility in lactating cows. Therefore, emphasis on selection for phenotypic divergence in RFI may not contribute to improved utilisation of consumed nutrients in Australian Holstein-Friesian dairy cows.
Feeding management in early life influences microbial colonisation and fermentation in the rumen of newborn goat kids
Authors: Abecia L. , Ramos-Morales E. , Martínez-Fernandez G. , Arco A. , Martín-García A. I. , Newbold C. J. , Yáñez-Ruiz D. R.
Published: July 2014

The aim of this work was to study the colonisation of the rumen by the three main microbial groups over the first 4 weeks of life and to assess to what extent the type of feeding management (natural with the mother, NAT, or artificial with milk replacer, ART) exerts an effect. Thirty pregnant goats carrying two fetuses were selected. At birth, one kid was taken immediately away from the doe and fed milk replacer (ART), while the other kid remained with the mother (NAT). Groups of four kids (from ART and NAT experimental groups) were slaughtered at 1, 3, 5, 7, 14, 21 and 28 days of life, resulting in seven sampling times. On the sampling day, after slaughtering, the rumen was weighed full and empty and the content sampled and pH measured. Aliquots of rumen digesta were immediately frozen for DNA and volatile fatty acid (VFA) analyses. The weight of the rumen was higher in NAT kids from Day 21 onward, while no difference was observed for rumen content volume. The three microbial groups (bacteria, archaea and protozoa) were detected from Day 1 in both experimental groups. The concentration of bacteria was higher in the rumen of NAT kids on Days 3, 5, 7 and 14 and of protozoa from Day 3 onward. This was reflected in greater VFA concentrations and lower pH in the rumen of NAT kids from Day 3. Our results confirmed substantial microbial colonisation from the first day of life in the undeveloped rumen. The feeding management (natural vs artificial) before weaning had an effect on microbial colonisation and rumen fermentation and, therefore, it should be considered when designing nutritional intervention strategies in early life.
Satiety factor oleoylethanolamide recruits the brain histaminergic system to inhibit food intake
Authors: Provensi Gustavo , Coccurello Roberto , Umehara Hayato , Munari Leonardo , Giacovazzo Giacomo , Galeotti Nicoletta , Nosi Daniele , Gaetani Silvana , Romano Adele , Moles Anna , Blandina Patrizio , Passani Maria Beatrice
Published: July 2014

Significance

Several endogenous molecules contribute to the building of a complex network of neural and hormonal signals that align food intake and energy expenditure. Cerebral histamine works as a satiety factor by activating histamine H
1
receptor (H
1
R) in specific hypothalamic nuclei. Indeed, atypical antipsychotics presumably cause obesity by targeting brain H
1
R. The endogenous lipid messenger oleoylethanolamide (OEA) mediates fat-induced satiety by engaging sensory fibers of the vagus nerve that project centrally. We find that depletion of brain histamine blunts OEA-induced hypophagia in mice. Our study uncovers previously unidentified neural signaling mechanisms involved in the anorectic action of OEA. Our data offer new perspectives for developing more effective and safer pharmacotherapies to treat obesity and ameliorate the profile of centrally acting drugs.
Land, irrigation water, greenhouse gas, and reactive nitrogen burdens of meat, eggs, and dairy production in the United States
Authors: Eshel Gidon , Shepon Alon , Makov Tamar , Milo Ron
Published: July 2014

Significance

Livestock-based food production is an important and pervasive way humans impact the environment. It causes about one-fifth of global greenhouse gas emissions, and is the key land user and source of water pollution by nutrient overabundance. It also competes with biodiversity, and promotes species extinctions. Empowering consumers to make choices that mitigate some of these impacts through devising and disseminating numerically sound information is thus a key socioenvironmental priority. Unfortunately, currently available knowledge is incomplete and hampered by reliance on divergent methodologies that afford no general comparison of relative impacts of animal-based products. To overcome these hurdles, we introduce a methodology that facilitates such a comparison. We show that minimizing beef consumption mitigates the environmental costs of diet most effectively.
Modeling gating charge and voltage changes in response to charge separation in membrane proteins
Authors: Kim Ilsoo , Chakrabarty Suman , Brzezinski Peter , Warshel Arieh
Published: July 2014

Significance

Determining voltage changes in response to charge separation within membrane proteins offers fundamental information on mechanisms of charge transport and displacement processes. However, correlating the observed voltage changes with the assumed mechanism is extremely challenging owing to uncertainties in macroscopic treatments and the fact that the electrode potential is not fixed. Here, we develop a coarse-grained model that determines the gating charges and the electrode potentials upon charge transfers in membrane proteins. The validity of the model is confirmed by comparing the calculated and measured voltage changes associated with electron and proton transfer in a bacterial photosynthetic reaction center. This model allows one to gain more confidence in the computational analysis than that obtained by continuum electrostatic assumptions.
Coordinated photomorphogenic UV-B signaling network captured by mathematical modeling
Authors: Ouyang Xinhao , Huang Xi , Jin Xiao , Chen Zheng , Yang Panyu , Ge Hao , Li Shigui , Deng Xing Wang
Published: July 2014

Significance

Plants sense long-wavelength and low-intensity UV-B light as a signal for the induction of photomorphogenesis. Recently, a number of regulatory factors involved in this developmental process have been uncovered through the use of conventional genetic and molecular approaches. A systematic understanding of the whole photomorphogenic UV-B signaling network, however, has not been achieved to date. Thus, in our study, we use a combination of mathematical modeling and biological experiments to capture the plausible mechanisms coordinating the different pathways in UV-B light signal transduction, which are difficult to define accurately in traditional wet laboratory studies.
Conjugacy classes of involutions and Kazhdan–Lusztig cells
Authors: Bonnafé Cédric , Geck Meinolf
Published: July 2014

According to an old result of Schützenberger, the involutions in a given two-sided cell of the symmetric groupSn\mathfrak {S}_nare all conjugate. In this paper, we study possible generalizations of this property to other types of Coxeter groups. We show that Schützenberger’s result is a special case of a general result on “smooth” two-sided cells. Furthermore, we consider Kottwitz’s conjecture concerning the intersections of conjugacy classes of involutions with the left cells in a finite Coxeter group. Our methods lead to a proof of this conjecture for classical types which, combined with further recent work, settles this conjecture in general.
Developmental Communication
Authors: Fisher Carla L.
Published: July 2014

Developmental communication is a relatively new perspective used to study interaction. Adopted in the 1980s and referred to as “developmental” or “life-span” communication, on a most basic level, such research mirrors its sister disciplines (psychology and sociology) in its focus on change across time. Communication scholars first reflected on this perspective after a 1979 National Communication Association Convention, which included a caucus on communication and aging, led by Carl Carmichael and Robert Hawkins. Over the next decade, notable scholars (e.g., Nikolas Coupland, Howard Giles, John Wiemann, Jon F. Nussbaum, Mark Knapp) further advocated the value of this perspective via a Fulbright International Colloquium and numerous books. These scholars heightened the value of a developmental approach to understanding communication. Jon F. Nussbaum’s groundbreaking book, Life-Span Communication: Normative Processes, was published in the late 1980s. Known as one of the most revolutionary developmental communication scholars, Nussbaum proposed that researchers use a life-span lens to better capture complexities of communication across an individual’s entire life. A developmental lens appreciates the notion that communication is not a singular event or object separate from time. Rather, “Communication is a primary skill to be mastered . . . Communication is best viewed as a flow of events across time rather than a static occurrence . . . Communication events are continuously unfolding and impacted by a wide range of individual characteristics and factors as well as previous experiences . . . As the communication process unfolds within human interaction, changes occur on numerous levels that may be manifested in different ways at various points in the life span . . . An individual’s capacity to communicate must continuously develop for that individual to master his or her environment and to interact effectively throughout the transitions, adaptations, and new challenges that arise over the life span” (Pecchioni, et al. 2005, pp. 10–11, cited under General Readings). A developmental lens illuminates that change is an inherent part of human interaction. Life-span research is known for focusing on “real-world” issues, being applied or translational, and interdisciplinary. Therefore, developmental communication scholars are known for engaging with the community and crossing disciplinary boundaries with fields such as psychology, sociology, gerontology, family studies, health, mass communication, and cultural studies. Today, developmental communication research is growing in abundance. Such scholarship has resulted in the production of significant knowledge about individual, relational, and societal levels of how communication evolves over time.
Transgenic Tomato Plants Overexpressing Tyramine N-Hydroxycinnamoyltransferase Exhibit Elevated Hydroxycinnamic Acid Amide Levels and Enhanced Resistance to Pseudomonas syringae
Authors: Campos Laura , Lisón Purificación , López-Gresa María Pilar , Rodrigo Ismael , Zacarés Laura , Conejero Vicente , Bellés José María
Published: July 2014

Hydroxycinnamic acid amides (HCAA) are secondary metabolites involved in plant development and defense that have been widely reported throughout the plant kingdom. These phenolics show antioxidant, antiviral, antibacterial, and antifungal activities. Hydroxycinnamoyl-CoA:tyramine N-hydroxycinnamoyl transferase (THT) is the key enzyme in HCAA synthesis and is induced in response to pathogen infection, wounding, or elicitor treatments, preceding HCAA accumulation. We have engineered transgenic tomato plants overexpressing tomato THT. These plants displayed an enhanced THT gene expression in leaves as compared with wild type (WT) plants. Consequently, leaves of THT-overexpressing plants showed a higher constitutive accumulation of the amide coumaroyltyramine (CT). Similar results were found in flowers and fruits. Moreover, feruloyltyramine (FT) also accumulated in these tissues, being present at higher levels in transgenic plants. Accumulation of CT, FT and octopamine, and noradrenaline HCAA in response to Pseudomonas syringae pv. tomato infection was higher in transgenic plants than in the WT plants. Transgenic plants showed an enhanced resistance to the bacterial infection. In addition, this HCAA accumulation was accompanied by an increase in salicylic acid levels and pathogenesis-related gene induction. Taken together, these results suggest that HCAA may play an important role in the defense of tomato plants against P. syringae infection.
Exploring the evolutionary history of centrosomes
Authors: Azimzadeh Juliette
Published: July 2014

The centrosome is the main organizer of the microtubule cytoskeleton in animals, higher fungi and several other eukaryotic lineages. Centrosomes are usually located at the centre of cell in tight association with the nuclear envelope and duplicate at each cell cycle. Despite a great structural diversity between the different types of centrosomes, they are functionally equivalent and share at least some of their molecular components. In this paper, we explore the evolutionary origin of the different centrosomes, in an attempt to understand whether they are derived from an ancestral centrosome or evolved independently from the motile apparatus of distinct flagellated ancestors. We then discuss the evolution of centrosome structure and function within the animal lineage.
Organization of early frog embryos by chemical waves emanating from centrosomes
Authors: Ishihara Keisuke , Nguyen Phuong A. , Wühr Martin , Groen Aaron C. , Field Christine M. , Mitchison Timothy J.
Published: July 2014

The large cells in early vertebrate development face an extreme physical challenge in organizing their cytoplasm. For example, amphibian embryos have to divide cytoplasm that spans hundreds of micrometres every 30 min according to a precise geometry, a remarkable accomplishment given the extreme difference between molecular and cellular scales in this system. How do the biochemical reactions occurring at the molecular scale lead to this emergent behaviour of the cell as a whole? Based on recent findings, we propose that the centrosome plays a crucial role by initiating two autocatalytic reactions that travel across the large cytoplasm as chemical waves. Waves of mitotic entry and exit propagate out from centrosomes using the Cdk1 oscillator to coordinate the timing of cell division. Waves of microtubule-stimulated microtubule nucleation propagate out to assemble large asters that position spindles for the following mitosis and establish cleavage plane geometry. By initiating these chemical waves, the centrosome rapidly organizes the large cytoplasm during the short embryonic cell cycle, which would be impossible using more conventional mechanisms such as diffusion or nucleation by structural templating. Large embryo cells provide valuable insights to how cells control chemical waves, which may be a general principle for cytoplasmic organization.
One to only two: a short history of the centrosome and its duplication
Authors: Sluder Greenfield
Published: July 2014

This review discusses some of the history of the fundamental, but not fully solved problem of how the centrosome duplicates from one to only two as the cell prepares for mitosis. We start with some of the early descriptions of the centrosome and the remarkably prescient but then controversial inferences drawn concerning its function in the cell. For more than 100 years, one of the most difficult issues for the concept of the centrosome has been to integrate observations that centrosomes appear to be important for spindle assembly in animal cells yet are not evident in higher plant cells and some animal cells. This stirred debate over the existence of centrosomes and their importance. A parallel debate concerned the role of the centrioles in organizing centrosomes. The relatively recent elucidation of bipolar spindle assembly around chromatin allows a re-examination of the role of centrioles in controlling centrosome duplication in animal cells. The problem of how centrosomes precisely double in preparation for mitosis in animal cells has now moved to the mystery of how only one procentriole is assembled at each mother centriole.
Historical roots of centrosome research: discovery of Boveri's microscope slides in Würzburg
Authors: Scheer Ulrich
Published: July 2014

Boveri's visionary monograph ‘Ueber die Natur der Centrosomen’ (On the nature of centrosomes) in 1900 was founded primarily on microscopic observations of cleaving eggs of sea urchins and the roundworm parasite
Ascaris
. As Boveri wrote in the introductory paragraph, his interests were less about morphological aspects of centrosomes, but rather aimed at an understanding of their physiological role during cell division. The remarkable transition from observations of tiny dot-like structures in fixed and sectioned material to a unified theory of centrosome function (which in essence still holds true today) cannot be fully appreciated without examining Boveri's starting material, the histological specimens. It was generally assumed that the microscope slides were lost during the bombing of the Zoological Institute in Würzburg at the end of WWII. Here, I describe the discovery of a number of Boveri's original microscope slides with serial sections of early sea urchin and
Ascaris
embryos, stained by Heidenhain's iron haematoxylin method. Some slides bear handwritten notes and sketches by Boveri. Evidence is presented that the newly discovered slides are part of the original material used by Boveri for his seminal centrosome monograph.
The PML-associated protein DEK regulates the balance of H3.3 loading on chromatin and is important for telomere integrity
Authors: Ivanauskiene Kristina , Delbarre Erwan , McGhie James D. , Küntziger Thomas , Wong Lee H. , Collas Philippe
Published: July 2014

Histone variant H3.3 is deposited in chromatin at active sites, telomeres, and pericentric heterochromatin by distinct chaperones, but the mechanisms of regulation and coordination of chaperone-mediated H3.3 loading remain largely unknown. We show here that the chromatin-associated oncoprotein DEK regulates differential HIRA- and DAAX/ATRX-dependent distribution of H3.3 on chromosomes in somatic cells and embryonic stem cells. Live cell imaging studies show that nonnucleosomal H3.3 normally destined to PML nuclear bodies is re-routed to chromatin after depletion of DEK. This results in HIRA-dependent widespread chromatin deposition of H3.3 and H3.3 incorporation in the foci of heterochromatin in a process requiring the DAXX/ATRX complex. In embryonic stem cells, loss of DEK leads to displacement of PML bodies and ATRX from telomeres, redistribution of H3.3 from telomeres to chromosome arms and pericentric heterochromatin, induction of a fragile telomere phenotype, and telomere dysfunction. Our results indicate that DEK is required for proper loading of ATRX and H3.3 on telomeres and for telomeric chromatin architecture. We propose that DEK acts as a “gatekeeper” of chromatin, controlling chromatin integrity by restricting broad access to H3.3 by dedicated chaperones. Our results also suggest that telomere stability relies on mechanisms ensuring proper histone supply and routing.
Macroprudential Ideas and Contested Social Purpose: A Response to Terrence Casey
Authors: Baker Andrew , Widmaier Wesley
Published: July 2014

In response to Terrence Casey's argument that the emergence of macroprudential regulation since the financial crash can and should save neoliberalism we raise five objections. 1). The Debt-Driven Growth Hypothesis (DDG) and the Financial Instability Hypothesis (FIH), as Casey terms them, are just as likely to be complementary as they are oppositional and they are by no means incompatible. 2) Casey's empirics are too thin and static, drawn from the 1980s and 1990s, while Anglo Liberal Financialised Capitalism (ALFC) is a complex adaptive system that has continued to evolve throughout the 2000s. 3) Casey overlooks the dynamic relationship between potentially excessive financialisation and the performance of the wider economy, which is becoming a growing concern for many policy makers using the macroprudential frame. 4) Macroprudential as a series of ideas about the economy are often incompatible with neoliberal premises and their ontological foundations. 5) Many of the policy makers who have acted as the biggest champions of macroprudential regulation have also been highly critical of ALFC and view the macroprudential turn as making a contribution to a much needed deeper financial reformation that would over time transform some of the constituent economic and social relations of the existing political economy. We conclude that what we call the social purpose of macroprudential regulation (the question of whether it is intended to patch up or transform the existing system) is contested, and that macroprudential regulation has much potential beyond saving ‘neoliberalism’.
Headspace‐Gas Chromatographic‐Mass Spectrometric Analysis of South American Commercial Solvents and their Use in the Illicit Conversion of Cocaine Base to Cocaine Hydrochloride
Authors: Mallette Jennifer R. , Casale John F.
Published: July 2014

This study presents data that establish the makeup of solvents utilized in illicit cocaine hydrochloride production, as determined via the identification of the occluded solvents in the crystal matrix of the final product. The occluded solvent ratios can differ dramatically from the ratios of the original processing solvents. Additionally, the presented data suggest the diversion of commercial solvents to illicit cocaine hydrochloride laboratories. Thirty‐five commercial solvents were obtained from five chemical manufacturing companies in South America. Each solvent was qualitatively and quantitatively analyzed using static headspace‐gas chromatography‐mass spectrometry (HS‐GC‐MS). After obtaining the chemical profile for each commercial solvent, solvents and/or solvent mixtures were prepared to be comparable in composition to several of the commercial products. Over 90 individual batches of cocaine hydrochloride were prepared from cocaine base using these solvents or solvent mixtures, which match those most commonly employed in clandestine laboratories. Additionally, a number of unique manufacturing by‐products produced from processing solvents were identified, and their significance is discussed.
The English Rogue: Afterlives and Imitations, 1665‐1741
Authors: Orr Leah
Published: July 2014

The English Rogue (1665) is one of the most reprinted and imitated works of fiction from the late seventeenth century, but it has been largely overlooked in recent studies of early fiction. This article analyses the afterlives of The English Rogue to argue that its success derives from later editors, who adapted it to suit changing tastes in the fiction market. Because of its many imitations, abridgements and adaptations, The English Rogue is a good barometer of trends in fiction in the period many modern scholars have identified as the origins of the modern novel form.
Hazardous birthday drinking among young people: population‐based impacts on emergency department and in‐patient hospital admissions
Authors: Callaghan Russell C. , Sanches Marcos , Gatley Jodi M. , Liu Lon‐Mu , Cunningham James K.
Published: July 2014

Background and Aims

There is growing concern about the possible adverse health impacts of binge drinking during birthday celebrations among adolescents and young adults. We estimate the impacts of birthday alcohol use on adolescent and young adult in‐patient/emergency department (ED) hospital admissions.

Design

We employed Autoregressive Integrated Moving Average (ARIMA) intervention analysis to assess whether the rate of ICD‐10 alcohol‐use‐disorder (AUD) events per 1000 in‐patient/ED admissions increased significantly during birthday weeks.

Setting

All in‐patient/ED admissions in Ontario, Canada from 1 April 2002 to 31 March 2007.

Participants

Individuals aged 12–30 years.

Measurements

AUD events per 1000 in‐patient/ED admissions by age in weeks.

Findings

Multiple increases were found. The largest occurred during the birthday week of 19 years of age, the beginning of the minimum legal drinking age (MLDA) in Ontario: AUD admission rates increased (spiked) by 38.30 per 1000 total admissions [95% confidence interval (CI) = 34.66–41.94] among males (a 114.3% increase over baseline), and by 28.13 (95% CI = 25.56–30.70) among females (a 164.0% increase). Among both genders, the second largest birthday‐week spikes occurred during ages 20–22 years, followed by somewhat lower but still pronounced birthday‐week spikes during ages 23–26 years and 30 years (all these spikes: P < 0.05). Birthday‐week spikes occurred as early as age 16 years for males and 14 years for females (both spikes: P < 0.05).

Conclusions

There appears to be an increase in alcohol‐related adverse events from drinking around the time of one's birthday among young adults in Canada.
Seasonal dynamics of macrohabitat use by small mammals in the Okavango Delta, Botswana: implications for landscape‐level disturbance resilience
Authors: Plavsic Militsa J.
Published: July 2014

In a changing climate, it is imperative to understand potential ecosystem resilience at all taxonomic levels. I compare seasonal small mammal utilization of woodlands (tree islands) and grasslands in the Okavango Delta, Botswana, to elucidate macrohabitat relationships and to test whether the two macrohabitats are similar in their ability to serve as a source of colonizers for the other after disturbance. Capture–mark–recapture data revealed that abundances for Dendromus mesomelas and Gerbilliscus leucogaster were higher in grasslands than tree islands, while Mus indutus abundance appeared higher in the grasslands in the dry season but roughly equal in the rainy season. Mastomys spp. and Steatomys pratensis maintained low levels in the grassland habitat throughout the year and experienced a population peak in the tree island habitat during the rainy season. There were no significant differences in sex ratio, mean mass or breeding condition. Dominance and total biomass were higher in the grasslands with the trend more pronounced in the rainy season. Terrestrial small mammals in the Okavango Delta employ differing strategies in macrohabitat selection and some exploit tree islands when herbaceous cover is present. Metacommunity dynamics exist for some species, and both habitats can serve as a source of colonizers under certain conditions.
The medico‐legal aspects of prescribing vitamin D
Authors: Davies John S. , Poole Chris D. , Feldschreiber Peter
Published: July 2014

Vitamin D is a particularly important sterol hormone and its effects beyond bone are increasingly recognized. Over the last decade clinical interest has grown in vitamin D, with increased recognition of deficiency and hence increased prescribing of vitamin D products. However, the increased prescription of vitamin D has generally been met with unlicensed vitamin D products which potentially expose the patient to clinical risk. This review discusses the issues relating to the clinical use of unlicensed vitamin D products, safety concerns that may arise from this, as well as discussing the medico‐legal responsibilities of the prescriber and dispenser.
Efficacy and Safety of PPC‐5650 on Experimental Rectal Pain in Patients with Irritable Bowel Syndrome
Authors: Nielsen Lecia Møller , Olesen Anne Estrup , Andresen Trine , Simrén Magnus , Törnblom Hans , Drewes Asbjørn Mohr
Published: July 2014

PPC‐5650 is a new pharmacological agent that can modulate acid‐sensing ion channel activity, leading to a reduction in the pain signal under up‐regulated conditions. The non‐clinical programme for PPC‐5650 supported a role for this novel agent in the treatment of pain in patients with irritable bowel syndrome (IBS). In patients with IBS, the aims of the study were: (1) to assess the efficacy of a single bolus of PPC‐5650 locally applied in the rectum using multi‐modal stimulations of the recto sigmoid and (2) to assess the safety profile of PPC‐5650. The study was a randomized, double‐blind, placebo‐controlled, cross‐over trial in patients with IBS, excluding females of child‐bearing potential. The study consisted of a training visit, study visit 1 and 2 and a follow‐up visit. Rectosigmoid electrical, thermal and mechanical stimulations were performed, pain perception was rated on a pain intensity scale and referred pain areas were assessed. All adverse events were registered.

Twenty‐five patients with IBS were enrolled and completed the study (9 women and 16 men; mean age 50.4 ± 12.7 years). No effects of the study drug were found on any of the rectal stimulations or for referred pain areas (all p > 0.05). No significant or clinically relevant treatment‐related differences were seen for the laboratory safety variables or any other reported adverse event.

In conclusion, in patients with IBS on rectal sensitivity to multi‐modal stimulations, PPC‐5650 did not produce efficacy relative to placebo. The overall safety and tolerability of PPC‐5650 was acceptable.