bluuebunny/crossref_metadata_2025 huggingface dataset:
Lysosomotropic agents: impact on lysosomal membrane permeabilization and cell death
Authors: Villamil Giraldo Ana M. , Appelqvist Hanna , Ederth Thomas , Öllinger Karin
Published: September 2014

Lysosomes are acidic organelles essential for degradation, signalling and cell homoeostasis. In addition, they play a key role in cell death. Permeabilization of the lysosomal membrane and release of hydrolytic enzymes to the cytosol accompanies apoptosis signalling in several systems. The regulatory mechanism of lysosomal stability is, however, poorly understood. Lipophilic or amphiphilic compounds with a basic moiety will become protonated and trapped within lysosomes, and such lysosomotropic behaviour is also found in many pharmacological drugs. The natural sphingolipid sphingosine exhibits lysosomotropic detergent ability and is an endogenous candidate for controlling lysosomal membrane permeabilization. The lysosomotropic properties of certain detergents might be of use in lysosome-targeting anticancer drugs and drug delivery system in the future. The present review summarizes the current knowledge on the targeting and permeabilizing properties of lysosomotropic detergents from a cellular and physicochemical perspective.
The contribution of astrocytes to Alzheimer's disease
Authors: Birch Amy M.
Published: September 2014

Astrocytes were historically classified as supporting cells; however, it is becoming increasingly clear that they actively contribute to neuronal functioning under normal and pathological conditions. As interest in the contribution of neuroinflammation to Alzheimer's disease (AD) progression has grown, manipulating glial cells has become an attractive target for future therapies. Astrocytes have largely been under-represented in studies that assess the role of glia in these processes, despite substantial evidence of astrogliosis in AD. The actual role of astrocytes in AD remains elusive, as they seem to adopt different functions dependent on disease progression and the extent of accompanying parenchymal inflammation. Astrocytes may contribute to the clearance of amyloid β-peptide (Aβ) and restrict the spread of inflammation in the brain. Conversely, they may contribute to neurodegeneration in AD by releasing neurotoxins and neglecting crucial metabolic roles. The present review summarizes current evidence on the multi-faceted functions of astrocytes in AD, highlighting the significant scope available for future therapeutic targets.
Dynamics of autophagosome formation: a pulse and a sequence of waves
Authors: Ktistakis Nicholas T. , Karanasios Eleftherios , Manifava Maria
Published: September 2014

Autophagosomes form in eukaryotic cells in response to starvation or to other stress conditions brought about by the unwanted presence in the cytosol of pathogens, damaged organelles or aggregated protein assemblies. The uniqueness of autophagosomes is that they form de novo and that they are the only double-membraned vesicles known in cells, having arisen from flat membrane sheets which have expanded and self-closed. The various steps describing their formation as well as most of the protein and lipid components involved have been identified. Furthermore, the hierarchical relationships among the components are well documented, and the mechanistic rationale for some of these hierarchies has been revealed. In the present review, we try to provide a current view of the process of autophagosome formation in mammalian cells, emphasizing along the way gaps in our knowledge that need additional work.
Astrocytosis in infantile neuronal ceroid lipofuscinosis: friend or foe?
Authors: Shyng Charles , Sands Mark S.
Published: September 2014

Infantile neuronal ceroid lipofuscinosis (INCL; infantile Batten disease) is an inherited paediatric neurodegenerative disease. INCL is caused by a deficiency in the lysosomal enzyme palmitoyl-protein thioesterase-1 (PPT1) and is thus classified as a lysosomal storage disease. Pathological examination of both human and murine INCL brains reveals progressive, widespread neuroinflammation. In fact, astrocyte activation appears to be the first histological sign of disease. However, the role of astrocytosis in INCL was poorly understood. The hallmark of astrocyte activation is the up-regulation of intermediate filaments, such as glial fibrillary acidic protein (GFAP) and vimentin. The role of astrocytosis in INCL was studied in a murine model lacking PPT1 and the intermediate filaments GFAP and vimentin (triple-knockout). This murine model of INCL with attenuated astrocytosis had an exacerbated pathological and clinical phenotype. The triple-knockout mouse had a significantly shortened lifespan, and accelerated cellular and humoural neuroinflammatory response compared with the parental PPT1−/− mouse. The data obtained from the triple-knockout mouse strongly suggest that astrocyte activation plays a beneficial role in early INCL disease progression. A more thorough understanding of the glial responses to lysosomal enzyme deficiencies and the accumulation of undergraded substrates will be crucial to developing effective therapeutics.
1.8 mW wideband LNA with double capacitor‐cross‐coupled feedback
Authors: Wang Zengqi , Li Zhiqun , Shen Changguo
Published: September 2014

A 1.8 mW wideband common‐gate (CG) low‐noise amplifier (LNA) with double capacitor‐cross‐coupled (CCC) feedback is presented for multiband wireless communication standards. To achieve a low‐noise figure (NF) and high‐voltage gain under low power consumption, the CG LNA is based on the double CCC feedback and current‐reuse techniques. Post‐layout simulated results for 0.18 μm CMOS implementations show that the voltage gain is 18.1 dB with a 3 dB bandwidth from 100 MHz to 1.7 GHz and the IIP3 is −4.9 dBm at 1 GHz. The average NF is 2.4 dB within the entire 3 dB bandwidth. The LNA consumes 1.8 mW from a 1.8 V DC supply and the active size is 0.15 × 0.14 mm2.
Microstrip diplexer for GSM and WLAN bands using common shorted stubs
Authors: Feng Wenjie , Gao Xin , Che Wenquan
Published: September 2014

A novel microstrip diplexer for global system of mobile (GSM) and wireless local area network (WLAN) bands using common shorted stubs is proposed. Two transmission zeros on both sides of the passband response can be easily realised for each passband. Additional transmission zeros created by the shorted stubs are introduced to suppress the harmonic of the microstrip diplexer. A microstrip diplexer with high isolation and selectivity can be achieved by locating the transmission zeros of each channel. A microstrip diplexer prototype with 30 dB isolation from 0.1 to 6.0 GHz has been designed and fabricated.
Accessibility of dynamic web applications with emphasis on visually impaired users
Authors: Okoye Kingsley , Jahankhani Hossein , Tawil Abdel‐Rahman H.
Published: September 2014

As the internet is fast migrating from static web pages to dynamic web pages, the users with visual impairment find it confusing and challenging when accessing the contents on the web. There is evidence that dynamic web applications pose accessibility challenges for the visually impaired users. This study shows that a difference can be made through the basic understanding of the technical requirement of users with visual impairment and addresses a number of issues pertinent to the accessibility needs for such users. We propose that only by designing a framework that is structurally flexible, by removing unnecessary extras and thereby making every bit useful (fit‐for‐purpose), will visually impaired users be given an increased capacity to intuitively access e‐contents. This theory is implemented in a dynamic website for the visually impaired designed in this study. Designers should be aware of how the screen reading software works to enable them make reasonable adjustments or provide alternative content that still corresponds to the objective content to increase the possibility of offering faultless service to such users. The result of our research reveals that materials can be added to a content repository or re‐used from existing ones by identifying the content types and then transforming them into a flexible and accessible one that fits the requirements of the visually impaired through our method (no‐frill + agile methodology) rather than computing in advance or designing according to a given specification.
Complete permutation Gray code implemented by finite state machine
Authors: Peng Li , Zeng Pingliang , Li Hao , Li Xin
Published: September 2014

An enumerating method of complete permutation array is proposed. The list of n ! permutations based on Gray code defined over finite symbol set Zn = {1, 2, …, n } is implemented by finite state machine, named as n ‐RPGCF. An RPGCF can be used to search permutation code and provide improved lower bounds on the maximum cardinality of a permutation code in some cases.
High-resolution photoabsorption spectrum of jet-cooled propyne
Authors: Jacovella U. , Holland D. M. P. , Boyé-Péronne S. , Joyeux D. , Archer L. E. , de Oliveira N. , Nahon L. , Lucchese R. R. , Xu Hong , Pratt S. T.
Published: September 2014

The absolute photoabsorption cross section of propyne was recorded between 62 000 and 88 000 cm−1 by using the vacuum-ultraviolet, Fourier-transform spectrometer at the Synchrotron Soleil. This cross section spans the region including the lowest Rydberg bands and extends above the Franck-Condon envelope for ionization to the ground electronic state of the propyne cation, $\tilde X^ +$X̃+. Room-temperature spectra were recorded in a flowing cell at 0.9 cm−1 resolution, and jet-cooled spectra were recorded at 1.8 cm−1 resolution and a rotational temperature of ∼100 K. The reduced widths of the rotational band envelopes in the latter spectra reveal new structure and simplify a number of assignments. Although nf Rydberg series have not been assigned previously in the photoabsorption spectrum of propyne, arguments are presented for their potential importance, and the assignment of one nf series is proposed. As expected from previous photoelectron spectra, Rydberg series are also observed above the adiabatic ionization threshold that converge to the v3+ = 1 and 2 levels of the C≡C stretching vibration.
Note: Enhanced production of He+ from the Versatile Ion Source (VIS) in off-resonance configuration
Authors: Castro G. , Mascali D. , Celona L. , Gammino S. , Caliri C. , Bartolo F. Di , Lanaia D. , Mazzaglia M. , Miracoli R. , Neri L. , Torrisi G. , Altana C. , Ciavola G.
Published: September 2014

The Versatile Ion Source (VIS) is a microwave discharge ion source installed at INFN-LNS and here used as test-bench for the production of high intensity low emittance proton beams and for studies on plasma physics. A series of measurements have been carried out with VIS in order to test the source with light ions. In particular a He+ beam has been characterized in terms of plasma discharge parameters. The experiment has been triggered by the observation of X-radiation emission from the plasma for some configuration of the magnetic field profile. The plasma electron energy distribution function is in fact modified when in some regions of the plasma chamber under-resonance discharge takes place, fulfilling the condition that allows the electromagnetic wave to electrostatic wave conversion. These tests allowed obtaining more than 50 mA of He+ beams.
Flush-mounted probe diagnostics for argon glow discharge plasma
Authors: Xu Liang , Cao Jinxiang , Liu Yu , Wang Jian , Du Yinchang , Zheng Zhe , Zhang Xiao , Wang Pi , Zhang Jin , Li Xiao , Qin Yongqiang , Zhao Liang
Published: September 2014

A comparison is made between plasma parameters measured by a flush-mounted probe (FP) and a cylindrical probe (CP) in argon glow discharge plasma. Parameters compared include the space potential, the plasma density, and the effective electron temperature. It is found that the ion density determined by the FP agrees well with the electron density determined by the CP in the quasi-neutral plasma to better than 10%. Moreover, the space potential and effective electron temperature calculated from electron energy distribution function measured by the FP is consistent with that measured by the CP over the operated discharge current and pressure ranges. These results present the FP can be used as a reliable diagnostic tool in the stable laboratory plasma and also be anticipated to be applied in other complicated plasmas, such as tokamaks, the region of boundary-layer, and so on.
Implementation of the scale factor balance on two pairs of quartz-flexure capacitive accelerometers by trimming bias voltage
Authors: Tu L. C. , Wang Z. W. , Liu J. Q. , Huang X. Q. , Li Z. , Xie Y. F. , Luo J.
Published: September 2014

Gravity gradient measurement makes use of the difference between the outputs of pairs of linear accelerometers, which results in cancelling out the common mode accelerations caused by mounting platform and external environment. One of the key technologies is to match the acceleration-to-voltage or acceleration-to-current transfer functions of the pairs of the accelerometers to an extremely high degree of accuracy. The differential signals then make the gravity gradients observable. By using two pairs of the quartz-flexure accelerometers with a capacitive sensing and electrostatic closed-loop control, the electrostatic control bias voltages were trimming remotely and automatically in real time. Each pair of accelerometers was matched individually and then all four accelerometers were finally re-balanced. The experimental results show that the consistency of five digits is achieved at a noise level of ∼\documentclass[12pt]{minimal}\begin{document}$5\times 10^{-8}\ \mathrm{g/\sqrt{Hz}}$\end{document}5×10−8g/ Hz (1 g ≈ 9.8 m/s2) and the scale factors ranging from 0.25 to 0.32 V/mg. Further improvement to the achieved level of matching is limited by the intrinsic noise of the accelerometers used.
Control effects of stimulus paradigms on characteristic firings of parkinsonism
Authors: Zhang Honghui , Wang Qingyun , Chen Guanrong
Published: September 2014

Experimental studies have shown that neuron population located in the basal ganglia of parkinsonian primates can exhibit characteristic firings with certain firing rates differing from normal brain activities. Motivated by recent experimental findings, we investigate the effects of various stimulation paradigms on the firing rates of parkinsonism based on the proposed dynamical models. Our results show that the closed-loop deep brain stimulation is superior in ameliorating the firing behaviors of the parkinsonism, and other control strategies have similar effects according to the observation of electrophysiological experiments. In addition, in conformity to physiological experiments, we found that there exists optimal delay of input in the closed-loop GPtrain|M1 paradigm, where more normal behaviors can be obtained. More interestingly, we observed that W-shaped curves of the firing rates always appear as stimulus delay varies. We furthermore verify the robustness of the obtained results by studying three pallidal discharge rates of the parkinsonism based on the conductance-based model, as well as the integrate-and-fire-or-burst model. Finally, we show that short-term plasticity can improve the firing rates and optimize the control effects on parkinsonism. Our conclusions may give more theoretical insight into Parkinson's disease studies.
Bright tunable femtosecond x-ray emission from laser irradiated micro-droplets
Authors: Yu Tong-Pu , Hu Li-Xiang , Yin Yan , Shao Fu-Qiu , Zhuo Hong-Bin , Ma Yan-Yun , Yang Xiao-Hu , Luo Wen , Pukhov Alexander
Published: September 2014

It is demonstrated that bright femtosecond X-rays can be obtained by irradiating a moderate laser onto a helium micro-droplet. The laser ponderomotive force continuously sweeps electrons from the droplets and accelerates them forward. The electrons exposed in the outrunning laser field oscillate transversely and emit photons in the forward direction. The total flux of photons with energies above 1 keV is as high as 109/shot which is about 10-fold enhancement compared with betatron oscillation under similar laser conditions. The maximum achieved peak brightness is up to 1021 photons/s/mm2/mrad2/0.1%BW. By adjusting laser and droplet parameters, we can get tunable X-rays with required brightness and energy.
Bulk ZnO as piezotronic pressure sensor
Authors: Baraki R. , Novak N. , Frömling T. , Granzow T. , Rödel J.
Published: September 2014

The impact of uniaxial compressive mechanical stress on the electrical properties of a ZnO varistor ceramic was studied with respect to a potential use in pressure sensor applications. Current-voltage measurements as a function of temperature are strongly affected by the applied stress. The modulation of charge transport properties with uniaxial stress causes large changes in resistance. Hence, a gauge factor of ∼800 is attained, which significantly exceeds the value of conventional sensors. The effect is attributed to the piezotronic effect, i.e., the altering of the potential barrier at grain boundaries due to the piezoelectricity of ZnO. This change in grain boundary potential barriers via mechanical deformation represents a promising physical concept for the development of better materials for sensor applications.
Composition dependent valence band order in c-oriented wurtzite AlGaN layers
Authors: Neuschl B. , Helbing J. , Knab M. , Lauer H. , Madel M. , Thonke K. , Meisch T. , Forghani K. , Scholz F. , Feneberg M.
Published: September 2014

The valence band order of polar wurtzite aluminum gallium nitride (AlGaN) layers is analyzed for a dense series of samples, grown heteroepitaxially on sapphire substrates, covering the complete composition range. The excitonic transition energies, found by temperature dependent photoluminescence (PL) spectroscopy, were corrected to the unstrained state using input from X-ray diffraction. k⋅p theory yields a critical relative aluminum concentration xc=(0.09±0.05) for the crossing of the uppermost two valence bands for strain free material, shifting to higher values for compressively strained samples, as supported by polarization dependent PL. The analysis of the strain dependent valence band crossing reconciles the findings of other research groups, where sample strain was neglected. We found a bowing for the energy band gap to the valence band with Γ9 symmetry of bΓ9=0.85eV, and propose a possible bowing for the crystal field energy of bcf=−0.12eV. A comparison of the light extraction efficiency perpendicular and parallel to the c axis of AlxGa1-xN/AlyGa1-yN quantum well structures is discussed for different compositions.
Direct femtosecond laser ablation of copper with an optical vortex beam
Authors: Anoop K. K. , Fittipaldi R. , Rubano A. , Wang X. , Paparo D. , Vecchione A. , Marrucci L. , Bruzzese R. , Amoruso S.
Published: September 2014

Laser surface structuring of copper is induced by laser ablation with a femtosecond optical vortex beam generated via spin-to-orbital conversion of the angular momentum of light by using a q-plate. The variation of the produced surface structures is studied as a function of the number of pulses, N, and laser fluence, F. After the first laser pulse (N = 1), the irradiated surface presents an annular region characterized by a corrugated morphology made by a rather complex network of nanometer-scale ridges, wrinkles, pores, and cavities. Increasing the number of pulses (2 < N < 100), the surface texture progressively evolves towards larger structures, while the central, non-ablated area is gradually decorated by nanoparticles produced during laser ablation. At large number of pulses (200 < N < 1000), a micro-tip with a nanostructured surface forms in the center of the irradiated area, which eventually disappears at still larger number of pulses (N > 1000) and a deep crater is formed. The nanostructure variation with the laser fluence, F, also evidences an interesting dependence, with a coarsening of the structure morphology as F increases. Our experimental findings demonstrate that direct femtosecond laser ablation with optical vortex beams produces interesting patterns not achievable by the more standard beams with a Gaussian intensity profile. They also suggest that appropriate tuning of the experimental conditions (F, N) can allow generating micro- and/or nano-structured surface for any specific application.
Metastability and relaxation in tensile SiGe on Ge(001) virtual substrates
Authors: Frigerio Jacopo , Lodari Mario , Chrastina Daniel , Mondiali Valeria , Isella Giovanni , Bollani Monica
Published: September 2014

We systematically study the heteroepitaxy of SiGe alloys on Ge virtual substrates in order to understand strain relaxation processes and maximize the tensile strain in the SiGe layer. The degree of relaxation is measured by high-resolution x-ray diffraction, and surface morphology is characterized by atomic force microscopy. The results are analyzed in terms of a numerical model, which considers dislocation nucleation, multiplication, thermally activated glide, and strain-dependent blocking. Relaxation is found to be sensitive to growth rate and substrate temperature as well as epilayer misfit and thickness, and growth parameters are found which allow a SiGe film with over 4 GPa of tensile stress to be obtained.
Suspended InAs nanowire gate-all-around field-effect transistors
Authors: Li Qiang , Huang Shaoyun , Pan Dong , Wang Jingyun , Zhao Jianhua , Xu H. Q.
Published: September 2014

Gate-all-around field-effect transistors are realized with thin, single-crystalline, pure-phase InAs nanowires grown by molecular beam epitaxy. At room temperature, the transistors show a desired high on-state current Ion of ∼10 μA and an on-off current ratio Ion/Ioff of as high as 106 at source-drain bias voltage of 50 mV and gate length of 1 μm with a gate underlap spacing of 1 μm from the source and from the drain. At low temperatures, the on-state current Ion is only slightly reduced, while the ratio Ion/Ioff is increased to 107. The field-effect mobility in the nanowire channels is also investigated and found to be ∼1500 cm2/V s at room temperature and ∼2000 cm2/V s at low temperatures. The excellent performance of the transistors is explained in terms of strong electrostatic and quantum confinements of carriers in the nanowires.
Effects of graphene on electro-optic switching and spontaneous polarization of a ferroelectric liquid crystal
Authors: Basu Rajratan
Published: September 2014

A small quantity of graphene flakes was doped in a ferroelectric liquid crystal (FLC), and the field-induced ferroelectric electro-optic switching was found to be significantly faster in the FLC + graphene hybrid than that of the pure FLC. Further studies revealed that the suspended graphene flakes enhanced the FLC's spontaneous polarization by improving smectic-C ordering resulting from the π–π electron stacking, and reduced rotation viscosity by trapping some of the free ions of the FLC media. These effects coherently impacted the FLC-switching phenomenon, enabling the FLC molecules to switch faster on reversing an external electric field.
Tuning of colossal dielectric constant in gold-polypyrrole composite nanotubes using in-situ x-ray diffraction techniques
Authors: Sarma Abhisakh , Sanyal Milan K.
Published: September 2014

In-situ x-ray diffraction technique has been used to study the growth process of gold incorporated polypyrrole nanotubes that exhibit colossal dielectric constant due to existence of quasi-one-dimensional charge density wave state. These composite nanotubes were formed within nanopores of a polycarbonate membrane by flowing pyrrole monomer from one side and mixture of ferric chloride and chloroauric acid from other side in a sample cell that allows collection of x-ray data during the reaction. The size of the gold nanoparticle embedded in the walls of the nanotubes was found to be dependent on chloroauric acid concentration for nanowires having diameter more than 100 nm. For lower diameter nanotubes the nanoparticle size become independent of chloroauric acid concentration and depends on the diameter of nanotubes only. The result of this study also shows that for 50 nm gold-polypyrrole composite nanotubes obtained with 5.3 mM chloroauric acid gives colossal dielectric constant of about 107. This value remain almost constant over a frequency range from 1Hz to 106 Hz even at 80 K temperature.
Flicker vortex structures in multiferroic materials
Authors: Zhao Z. , Ding X. , Salje E. K. H.
Published: September 2014

Computer simulation of ferroelastic materials reveals dynamic polar vortex structures related to flexo-electricity between cation and anion lattices. At finite temperatures, the vortices are found to flicker in time and space. Widely spaced ferroelastic twin boundaries nucleate vortices while dense twin boundaries suppress them. The time averaged number of vortices at any site decays exponentially, indicating the highly mobile dynamics of the vortex lattice. Applied electric fields break the rotational symmetry of vortices and finally destroy them. The total number density of vortices follows a field and temperature dependence as N(E)=N0/[1+A exp(E/k(T−TVF))] with TVF < 0. The observed vortex structures are akin to those observed in magnetic and superconducting disordered vortex lattices.
Spectroscopy of Nafion in terahertz frequency range
Authors: Yurchenko Stanislav O. , Zaytsev Kirill I.
Published: September 2014

We report results on the terahertz (THz) spectroscopy of polymer Nafion. Using THz pulse spectroscopy and refined post-processing algorithms based on the ill-posed spectroscopic inverse problem analysis, we find the complex dielectric permittivity of Nafion to be in the range 0.15–1.5 THz. The results in the low-frequency (gigahertz) range agree well with known measurements. We find that the complex dielectric permittivity can be described well using the double-Debye model with relaxation times of 7.20 ± 0.05 ps and 0.12 ± 0.05 ps. This result is discussed briefly from the viewpoint of the appearance of a segregated structure in the “Nafion–water” system.
Evaluation of fructosamine as a new biomarker for diagnosis of hepatic lipidosis in dairy cows
Authors: Mostafavi Masoud , Seifi Hesam A. , Mohri Mehrdad , Jamshidi Abdullah
Published: September 2014

An abattoir-based cohort study using liver and serum specimens from Holstein dairy cows (452 healthy and 54 fatty liver cases) was conducted. Serum fructosamine and other biochemical parameters and fat content of liver specimens were measured. There were significant negative correlations of fructosamine with hepatic lipid content (P = 0.001), and serum total bilirubin (P = 003) and significant positive correlation with glucose (P < 0.02), albumin (P < 0.0001) and cholesterol (P < 0.0001) within normal cows. In fatty liver-affected cows significant positive correlations were seen between fructosamine and cholesterol (P < 0.0001) and albumin (P < 0.0001). In addition fructosamine had a significant negative correlation with the ratio of non-esterified fatty acids to cholesterol in both normal (P < 0.0001) and fatty liver-affected cows (P = 0.006). We found that serum fructosamine concentration was lower (P < 0.001) in cows suffering from fatty liver. The area under the receiver operating characteristic curve of fructosamine for diagnosis of fatty liver was 67.6. Optimum fructosamine cut-point based on the maximum total of sensitivity (SE) and specificity (SP) was <213 µmol/L (SE = 71%; SP = 65). Cows with serum fructosamine concentrations below 213 µmol/L were 4.5 times more likely to have hepatic lipidosis (odds ratio = 4.5; 95% CI = 2.4–8.6; P < 0.0001). We found that fructosamine showed a combination of high SE, SP, which was greater than aspartate aminotransferase, non-esterified fatty acids, β-hydroxybutyrate, total cholesterol, bile acids and bilirubin. In addition, fructosamine showed a positive likelihood ratio of 2.0, and negative likelihood ratio of 0.45. In conclusion, the present results indicate that fructosamine measurement could improve the diagnosis of fatty liver in dairy cows.
Effectiveness of various sorbents and biological oxidation in the removal of arsenic species from groundwater
Authors: Corsini Anna , Cavalca Lucia , Muyzer Gerard , Zaccheo Patrizia
Published: September 2014

Environmental context Arsenic contamination of aquifers is a worldwide public health concern and several technologies have been developed to reduce the arsenic content of groundwater. We investigated the efficiency of various materials for arsenic removal from groundwater and found that iron-based sorbents have great affinity for arsenic even if groundwater composition can depress their ability to bind arsenic. Moreover, we showed that the use of microorganisms can enhance the removal of arsenic from groundwater. Abstract The AsIII and AsV adsorption capacity of biochar, chabazite, ferritin-based material, goethite and nano zero-valent iron was evaluated in artificial systems at autoequilibrium pH (i.e. MilliQ water without adjusting the pH) and at approximately neutral pH (i.e. TRIS-HCl, pH 7.2). At autoequilibrium pH, iron-based sorbents removed 200μgL–1 As highly efficiently whereas biochar and chabazite were ineffective. At approximately neutral pH, sorbents were capable of removing between 17 and 100% of AsIII and between 3 and 100% of AsV in the following order: biochar<chabazite<ferritin-based material<goethite<nano zero-valent iron. Chabazite, ferritin-based material and nano zero-valent iron oxidised AsIII to AsV and ferritin-based material was able to reduce AsV to AsIII. When tested in naturally As-contaminated groundwater, a marked decrease in the removal effectiveness occurred, due to possible competition with phosphate and manganese. A biological oxidation step was then introduced in a one-phase process (AsIII bio-oxidation in conjunction with AsV adsorption) and in a two-phase process (AsIII bio-oxidation followed by AsV adsorption). Arsenite oxidation was performed by resting cells of Aliihoeflea sp. strain 2WW, and arsenic adsorption by goethite. The one-phase process decreased As in groundwater to 85%, whereas the two-phase process removed up to 95% As, leaving in solution 6μgL–1 As, thus meeting the World Health Organization limit (10μgL–1). These results can be used in the scaling up of a two-phase treatment, with bacterial oxidation of As combined to goethite adsorption.
Silencing of a metaphase I-specific gene results in a phenotype similar to that of the Pairing homeologous 1 (
Ph1
) gene mutations
Authors: Bhullar Ramanjot , Nagarajan Ragupathi , Bennypaul Harvinder , Sidhu Gaganpreet K. , Sidhu Gaganjot , Rustgi Sachin , von Wettstein Diter , Gill Kulvinder S.
Published: September 2014

Significance

Maintaining diploid-like pairing behavior is essential for a polyploid to establish as a new species. The Pairing homeologous 1 (
Ph1
) gene, regulating such behavior in polyploid wheat, was identified in 1958, but its molecular function remained elusive. The present communication reports identification of the candidate
Ph1
(
C-Ph1
) gene that is expressed exclusively during meiotic metaphase I, whose silencing resulted in formation of multivalents like the
Ph1
gene mutations. Although the
C-Ph1
gene has three homoeologous copies, the
5B
copy has diverged in sequence from the other two copies. Heterologous gene silencing of the
Arabidopsis
homologue of the
C-Ph1
gene also confirmed its function. Molecular characterization of this gene will make it possible to develop precise alien introgression strategies.
A1adenosine receptor–stimulated exocytosis in bladder umbrella cells requires phosphorylation of ADAM17 Ser-811 and EGF receptor transactivation
Authors: Prakasam H. Sandeep , Gallo Luciana I. , Li Hui , Ruiz Wily G. , Hallows Kenneth R. , Apodaca Gerard
Published: September 2014

Despite the importance of ADAM17-dependent cleavage in normal biology and disease, the physiological cues that trigger its activity, the effector pathways that promote its function, and the mechanisms that control its activity, particularly the role of phosphorylation, remain unresolved. Using native bladder epithelium, in some cases transduced with adenoviruses encoding small interfering RNA, we observe that stimulation of apically localized A1adenosine receptors (A1ARs) triggers a Gi-Gβγ-phospholipase C-protein kinase C (PKC) cascade that promotes ADAM17-dependent HB-EGF cleavage, EGFR transactivation, and apical exocytosis. We further show that the cytoplasmic tail of rat ADAM17 contains a conserved serine residue at position 811, which resides in a canonical PKC phosphorylation site, and is phosphorylated in response to A1AR activation. Preventing this phosphorylation event by expression of a nonphosphorylatable ADAM17S811Amutant or expression of a tail-minus construct inhibits A1AR-stimulated, ADAM17-dependent HB-EGF cleavage. Furthermore, expression of ADAM17S811Ain bladder tissues impairs A1AR-induced apical exocytosis. We conclude that adenosine-stimulated exocytosis requires PKC- and ADAM17-dependent EGFR transactivation and that the function of ADAM17 in this pathway depends on the phosphorylation state of Ser-811 in its cytoplasmic domain.
Dynamin recruitment and membrane scission at the neck of a clathrin-coated pit
Authors: Cocucci Emanuele , Gaudin Raphaël , Kirchhausen Tom
Published: September 2014

Dynamin, the GTPase required for clathrin-mediated endocytosis, is recruited to clathrin-coated pits in two sequential phases. The first is associated with coated pit maturation; the second, with fission of the membrane neck of a coated pit. Using gene-edited cells that express dynamin2-EGFP instead of dynamin2 and live-cell TIRF imaging with single-molecule EGFP sensitivity and high temporal resolution, we detected the arrival of dynamin at coated pits and defined dynamin dimers as the preferred assembly unit. We also used live-cell spinning-disk confocal microscopy calibrated by single-molecule EGFP detection to determine the number of dynamins recruited to the coated pits. A large fraction of budding coated pits recruit between 26 and 40 dynamins (between 1 and 1.5 helical turns of a dynamin collar) during the recruitment phase associated with neck fission; 26 are enough for coated vesicle release in cells partially depleted of dynamin by RNA interference. We discuss how these results restrict models for the mechanism of dynamin-mediated membrane scission.
1 The View from the Bench: Where the Comparative Judicial Imagination Travels
Authors: Ran Hirschl
Published: September 2014

This chapter explores how constitutional courts and judges conceive of comparative constitutional law, what methods they use to engage with it, and how and why they vary in their approach. The chapter surveys the changing patterns of voluntary judicial reference to foreign sources and the explanations for these. It addresses the decrease in reference to the UK and US apex courts and the rise in stature of other courts. Patterns of foreign citations by the Supreme Courts of Canada, India, and especially Israel are examined. The chapter develops the argument that the sociopolitical context within which constitutional courts and judges operate affects whether and where the judicial mind travels in its search for citation of foreign sources. It shows that the “identity” dimension—the attempt to define who “we” are as a political community—inevitably influences comparative jurisprudence and acts as a key factor explaining judicial choices of reference sources.
3 Engaging the Constitutive Laws of Others: Necessities, Ideas, Interests
Authors: Ran Hirschl
Published: September 2014

The chapter explores some key junctures in the intellectual history of comparative public law in the early-modern and modern eras. It highlights how the interplay between intellectual inquisitiveness and instrumentalism has influenced many of the field’s epistemological leaps, from the first attempts in the 16th century to delineate a universal public law and to study comparative government in a methodical fashion (John Selden, Montesquieu, and Simón Bolívar, among others), to the current renaissance of comparative constitutional inquiry particularly in Europe, the United States, and Canada. The examples illustrate that comparative constitutional inquiry is best understood as being driven by a combination of intellectual innovation and a compatible political agenda or ideological outlook. In some instances, intellectual pursuit led the way with an instrumentalist goal or ideological agenda providing added impetus. In other instances, comparative constitutional inquiry was more directly driven by political interests, ambitions, and aspirations, writ small or large.
4 From Comparative Constitutional Law to Comparative Constitutional Studies
Authors: Ran Hirschl
Published: September 2014

The chapter argues for an interdisciplinary approach to comparative constitutional inquiry that is methodologically and substantively preferable to doctrinal accounts. It suggests that for historical, analytical, and methodological reasons, maintaining the disciplinary divide between comparative constitutional law and other closely related disciplines that study various aspects of the same constitutional phenomena, artificially and unnecessarily limits our horizons and restricts the questions asked as well as the answers provided. Traditional disciplinary boundaries, both substantive and methodological, between comparative (public) law and the social sciences continue to impede the development of comparative constitutional studies as an ambitious, coherent, and theoretically advanced area of inquiry. By engaging in a dialogue with the social sciences, and political science in particular, comparative constitutional inquiries would go beyond the traditional realms of judicial review to consider extrajudicial factors such as judicial behaviour, the origins of constitutional change, constitutional design, and the real-life effects of constitutional jurisprudence.
5 How Universal is Comparative Constitutional Law?
Authors: Ran Hirschl
Published: September 2014

This chapter addresses issues central to comparative constitutional law’s epistemological and methodological domain. First, the possibility of comparisons of constitutional law and institutions across time and space, notably between “universalists,” who emphasize common elements of legal (and constitutional) systems across time and place, and “particularists” who emphasize the unique nature of any given legal (and constitutional) system. “Third way” alternatives such as constitutional pluralism are also examined. Second, the “global south” critique in comparative constitutional law, or how truly “comparative,” universal, or generalizable are the lessons of a body of knowledge that draws almost exclusively on a small—not necessarily representative—set of frequently studied jurisdictions and court rulings to advance what is portrayed as generic and universally applicable prescriptions. The global south critique poses major challenges to contemporary comparative constitutional inquiry but has its own analytical challenges. Examples include South Africa, India, and the European Court of Human Rights.
Understanding Performance Expression in Popular Music Recordings
Authors: Dibben Nicola
Published: September 2014

This chapter explores the possibilities and limits of studying expressiveness in recorded popular music from an empirical perspective. Research into performance expression has tended to treat the recording as a documentary trace of a performance event. In popular music, where the recording most often is the “event,” such an approach raises questions about how expression might operate in this context. This chapter offers two analyses that highlight complementary conceptions of expression—first, an expressive performance premised on an aesthetic of naturalism which bears the trace of human variability (Adele’s soul-influenced vocal performance of “Someone Like You”), revealing similarities to performance expression in classical and romantic genres, and secondly, the role of studio production in creating expressive performances, exemplified by a hip-hop track (Kanye West’s performance of “Stronger”), premised upon a “post-human” aesthetic that combines human and machine-like performance. The discussion highlights the cultural specificity of models of performance expression.
Expressiveness in Funk
Authors: Ashley Richard
Published: September 2014

Funk, as a musical genre or manner of musical performance, poses significant questions for empirical research due to its typical materials. Funk de-emphasizes harmony—a primary element of western music—and uses a highly regular, almost metronomic rhythmic framework. Thus expressiveness in funk must be sought in other musical parameters, such as interplay between performers, microtiming, or timbre.  This chapter examines funk from the perspective of its primary expressive aspect, that of groove. Recent relevant literature, both psychological and musicological, is reviewed, and music-structural features which seem to contribute strongly to groove are identified.  These factors are then investigated through examination of musical excerpts from Stevie Wonder, Parliament, and Tower of Power. The roles of pitch, meter, microtiming,  motive/gesture, and timbre in creating expressive performances within the constraints of the groove are explored, as well as directions for future research.
Using Computational Models of Music Performance to Model Stylistic Variations
Authors: Friberg Anders , Bisesi Erica
Published: September 2014

The performance variations introduced by the musicians have been generalized into computational models in the KTH rule system. The models can convey gestural information about physical movement as well as emotional expression. The rule system was extended with new rules modelling metric, harmonic, melodic contour, and grouping accents as suggested by Parncutt (2003), and for interaction of rules. The accents are automatically rendered using a local shape of increased sound level and slower tempo around the accented note. We consider the rule system as a toolbox containing a set of general performance principles that to a certain extent have biological foundation. Then, the application of the rules depends on the intention, style, personal preferences, etc. We show how this can be done for three cases representing a music example from three different historical periods of piano music: baroque, romantic, and contemporary art music.
Training Expressive Performance by Means of Visual Feedback
Authors: Timmers Renee , Sadakata Makiko
Published: September 2014

This chapter explores current use of automated feedback techniques among musicians, and the anticipated usefulness of such systems. It examines purpose-designed software available for performers, and then summarizes the results of experimental investigations of the effectiveness of feedback systems in enhancing practicing to perform musical excerpts in various expressive manners. The methodological challenges of designing a program that can be applied in a general manner without biasing practice and performance are discussed. Promising avenues are suggested—for example, by making feedback summative rather than real-time, and based on probabilistic learning from target examples. In addition, the training may be to widely explore performance expression rather than to reinforce through imitation. The survey discussed indicates that if a user-friendly, reliable, and non-biasing product is realized, it is very likely to be adopted for a multitude of reasons, including feedback on ensemble timing, expressive interpretation, and aspects of performance control.
Implications for Cognitive Studies of Musical Expressiveness
Authors: Stevens Catherine J.
Published: September 2014

Studies of expressiveness in music from a cognitive psychological perspective have, until now, tended to analyze emotional response to music as a proxy for expression. The present collection, together with contemporary views of cognition as extended, situated, distributed, and embodied, point to the significance of cultural, social and historical influences on what it is to be expressive. Building from these updated assumptions, this brief prospective for cognitive studies discusses multimodal and inter-sensory expressiveness in music, song as a natural intersection of speech and music, and the importance of investigating diverse musical materials, performance settings, and genres. The challenge for cognitive psychology is to develop sophisticated ways of observing, recording, analyzing, and interpreting musical phenomena that connect across levels of description. The knitting together of micro and macro levels of description via theory is The Next Big Thing.
Implications for Education
Authors: Williamon Aaron
Published: September 2014

In some music educational contexts, a distinction is made between technical and expressive skills. It is argued that the former are within reach of anyone who is motivated to work hard, pay attention, and heed instruction. The latter, on the other hand, are accessed through more mysterious, subjective, and ephemeral processes—they are skills that simply “cannot be taught.” Irrespective of whether musical skills should be viewed in such dichotomous terms, it is clear from a large and growing body of research that the wide range of musical skills that typically fall within the “expressive” category are indeed amenable to learning and teaching. This chapter therefore addresses the questions of how expressive skills are learned, and how research can begin to inform and direct this learning process.
The convection–diffusion equation
Authors: Stuart A. M. , Söli E.
Published: September 2014

This chapter concerns the statement of the steady convection–diffusion equation and its weak formulation. This is followed by a description of finite element discretization and properties of the discrete problem, including error bounds, stabilization methods and matrix properties.
Quantum noise and quantum measurement
Authors: Clerk A.
Published: September 2014

This chapter covers the basics of quantum noise and the subtle aspects of Caves’ theorem on quantum-limited amplifiers. It introduces on the one hand the susceptibilities of a quantum measurement system, and on the other the crucial Nyquist model of dissipation, which is essential to the understanding of the quantum fluctuation-dissipation theorem for a passive system and the constraints on noise for an active system. Great insight on the paradoxical properties of quantum noise can be obtained by comparing, in the calculation of the noise of an active circuit, the point of view of susceptibilities and response functions with the point of view of input-output theory dominated by the formalism of the scattering matrix. In particular, the chapter provides an explanation of the existence of different optimum working points for a nonmatched amplifier if one optimizes the gain or the noise.
Readout of superconducting qubits
Authors: Esteve D.
Published: September 2014

The course summarized in this chapter covered the readout of superconducting qubits in the general framework of quantum measurement theory.
Quantum information science: experimental implementation with trapped ions
Authors: Monz T. , Schindler P. , Nigg D. , Blatt R.
Published: September 2014

This chapter discusses ion-trap-based quantum computation. Itexplains why ion traps constitute the most advanced quantum information processors to date.