bluuebunny/crossref_metadata_2025 huggingface dataset:
Insulin-stimulated leptin secretion requires calcium and PI3K/Akt activation
Authors: Wang Yue , Ali Yusuf , Lim Chun-Yan , Hong Wanjin , Pang Zhiping P. , Han Weiping
Published: January 2014

Numerous studies have focused on the regulation of leptin signalling and the functions of leptin in energy homoeostasis; however, little is known about how leptin secretion is regulated. In the present study we studied leptin storage and secretion regulation in 3T3-L1 and primary adipocytes. Leptin is stored in membrane-bound vesicles that are localized predominantly in the ER (endoplasmic reticulum) and close to the plasma membrane of both 3T3-L1 and primary adipocytes. Insulin increases leptin secretion as early as 15 min without affecting the leptin mRNA level. Interestingly, treatment with the protein synthesis inhibitor cycloheximide and the ER–Golgi trafficking blocker Brefeldin A inhibit both basal and ISLS (insulin-stimulated leptin secretion), suggesting that insulin stimulates leptin secretion by up-regulating leptin synthesis and that leptin-containing vesicles go through the ER–Golgi route. The PI3K (phosphoinositide 3-kinase)/Akt, but not MAPK (mitogen-activated protein kinase), pathway is involved in ISLS in vitro and in vivo. Although Ca2+ triggers synaptic vesicle and secretory granule exocytosis, Ca2+ influx alone is not sufficient to induce leptin secretion. Remarkably, Ca2+ is required for ISLS possibly due to its involvement in insulin-stimulated Akt phosphorylation. We conclude that insulin stimulates leptin release through the PI3K/Akt pathway and that Ca2+ is required for robust Akt phosphorylation and leptin secretion.
Structural basis of conformational transitions in the active site and 80′s loop in the FK506-binding protein FKBP12
Authors: Mustafi Sourajit M. , Brecher Matthew , Zhang Jing , Li Hongmin , Lemaster David M. , Hernández Griselda
Published: January 2014

The extensive set of NMR doublings exhibited by the immunophilin FKBP12 (FK506-binding protein 12) arose from a slow transition to the cis-peptide configuration at Gly89 near the tip of the 80′s loop, the site for numerous protein-recognition interactions for both FKBP12 and other FKBP domain proteins. The 80′s loop also exhibited linebroadening, indicative of microsecond to millisecond conformational dynamics, but only in the trans-peptide state. The G89A variant shifted the trans–cis peptide equilibrium from 88:12 to 33:67, whereas a proline residue substitution induced fully the cis-peptide configuration. The 80′s loop conformation in the G89P crystal structure at 1.50 Å resolution differed from wild-type FKBP12 primarily at residues 88, 89 and 90, and it closely resembled that reported for FKBP52. Structure-based chemical-shift predictions indicated that the microsecond to millisecond dynamics in the 80′s loop probably arose from a concerted main chain (ψ88 and ϕ89) torsion angle transition. The indole side chain of Trp59 at the base of the active-site cleft was reoriented ~90o and the adjacent backbone was shifted in the G89P crystal structure. NOE analysis of wild-type FKBP12 demonstrated that this indole populates the perpendicular orientation at 20%. The 15N relaxation analysis was consistent with the indole reorientation occurring in the nanosecond timeframe. Recollection of the G89P crystal data at 1.20 Å resolution revealed a weaker wild-type-like orientation for the indole ring. Differences in the residues that underlie the Trp59 indole ring and altered interactions linking the 50′s loop to the active site suggested that reorientation of this ring may be disfavoured in the other six members of the FKBP domain family that bear this active-site tryptophan residue.
Using composite low rank and sparse graph for label propagation
Authors: Guo Junjun , Wu Daiwen
Published: January 2014

Based on the low rank representation (LRR) and the sparse representation (SR), a composite LRR with SR graph LRRSR for semi‐supervised label propagation is proposed. The LRRSR aims to capture both the global structure of the data by a low rank constraint and the local structure of the data by a sparse constraint simultaneously. A composite framework is applied to fuse the two graphs. Then, a label propagation framework is used to transmit the labels from the labelled samples to the unlabelled samples. It is applied on several face image datasets and the experimental results demonstrate its good performance for face classification with a limited number of labelled samples.
High performance hysteresis modulation technique for high‐order PFC circuits
Authors: Bodetto M. , El Aroudi A. , Cid‐Pastor A. , Martinez‐Salamero L.
Published: January 2014

A simple control strategy to reduce the total harmonic distortion in single‐stage high‐order power factor correction AC–DC circuits is presented. A variable hysteresis window is used to improve the system performance near the zero crossing of the input current by increasing the switching frequency near this region.
Hiding rollback latency in log‐based eager hardware transactional memory
Authors: Lee Sungjae , Lee Inhwan
Published: January 2014

The use of a rollback buffer (RB) for hiding the rollback latency in log‐based eager hardware transactional memory is proposed. The RB allows a transaction to abort without performing rollback, but still makes the transaction's old values immediately available. In effect, the rollback latency almost disappears. When running the Stanford transactional applications for multi‐processing benchmark on a 16‐core processor that implements the LogTM‐SE, the speedup (decrease in execution time) achieved with a 2 KB RB is 15.8% on average.
Using interaction between two nonlinear systems to improve IIP3 in active mixers
Authors: Asghari M. , Yavari M.
Published: January 2014

A new linearisation technique for active mixers is introduced to enhance the third‐order input intercept point (IIP3). This technique is based on the cancellation of the third‐order Volterra kernel in the output current of the transconductance stage by using the interaction between two nonlinear systems. In this scheme, a nonlinear circuit is employed prior to the conventional mixer to improve the total IIP3 by adjusting its second‐order Volterra kernel magnitude and phase. Moreover, the added circuit increases the conversion gain of the mixer. The simulation results show that both the IIP3 and the conversion gain simultaneously improve by 13 and 11.4 dB, respectively, compared with the conventional active mixer.
Asymmetrical wideband zeroth‐order resonant antenna
Authors: Amani N. , Jafargholi A. , Kamyab M. , Vaziri A.
Published: January 2014

A new asymmetrical zeroth‐order resonant antenna with improved efficiency and widened impedance bandwidth is proposed. It comprises a rectangular patch, two shorted stubs and a coplanar waveguide feed to have composite right/left‐handed features and an easy fabrication process. The asymmetry helps to combine three resonance frequencies and extends the bandwidth up to 61.6%. The efficiency of the proposed antenna is >85% over the entire bandwidth of 4.41–8.34 GHz. The proposed antenna has a compact size, which can provide an omni‐directional radiation pattern suitable for wireless applications. These features are verified by CST Microwave Studio and compared with the experimental results.
Theoretical and experimental analysis of spatial division using antenna directivities in short‐range MIMO transmission
Authors: Arai M. , Seki T. , Hiraga K. , Nakagawa T. , Uehara K.
Published: January 2014

A simple method is proposed for achieving short‐range multiple‐input multiple‐output (MIMO) transmission without complicated signal processing. This is achieved by a spatial division that cancels interference between signal streams by using π‐phase‐shifted antenna directivities in high speed parallel transmission systems at 60 GHz. The method achieves spatial division transmission without MIMO detection even for antenna elements with wide beamwidths. This makes it easy to design antenna elements and reduces signal processing costs in the transmitter and the receiver. Moreover, the method provides almost the same channel capacity as that of the complicated MIMO transmission methods. The optimal antenna array length is derived to maximise the capacity and the validity of the proposed method is confirmed through numerical and experimental analyses at 4.85 GHz.
Compact low driving voltage (<400 mVpp) electro‐absorption modulator laterally integrated with VCSEL
Authors: Dalir H. , Takahashi Y. , Koyama F.
Published: January 2014

An ultra‐compact (8 µm long) electro‐absorption modulator is presented which is laterally integrated with a 980 nm InGaAs vertical cavity surface emitting laser incorporating a bow‐tie‐shaped oxide aperture. A low driving voltage operation below 400 mVpp for a dynamic extinction ratio of 6 dB and a large signal modulation of up to 25 Gbit/s is demonstrated. The static extinction ratio of over 6 dB can be obtained by applying an extremely low voltage of −200 mV.
One‐step fabrication and high photocatalytic activity of porous graphitic carbon nitride synthesised via direct polymerisation of dicyandiamide without templates
Authors: Yu Qingbo , Li Xianhua , Zhang Mingxu
Published: January 2014

Porous graphitic carbon nitride (g‐C3N4) has been synthesised by means of one‐step calcinations of dicyandiamide for efficient photocatalysis under visible light irradiation (λ > 400 nm). Scanning electron microscopy images demonstrate that the as‐prepared photocatalyst calcined at 650°C is a porous structure. The UV–vis diffuse reflectance spectra show that the optical absorption for the porous g‐C3N4 is more intensive than for common g‐C3N4 calcined at 550°C. The enhanced generation of the photocurrent under visible light irradiation (λ > 400 nm) is observed by using the porous g‐C3N4. The results of the photocatalytic experiments under visible light irradiation reveal that the photocatalytic degradation of methylene blue using the porous g‐C3N4 is higher than common g‐C3N4, showing the advantage of the structure for efficient photocatalysis. The presence of the calcinations temperature is presumed to play a key role in adjusting the textural properties.
Device for filamentous fungi growth monitoring using the multimodal frequency response of cantilevers
Authors: Maloney N. , Lukacs G. , Ball S. L. , Hegner M.
Published: January 2014

Filamentous fungi cause opportunistic infections in hospital patients. A fast assay to detect viable spores is of great interest. We present a device that is capable of monitoring fungi growth in real time via the dynamic operation of cantilevers in an array. The ability to detect minute frequency shifts for higher order flexural resonance modes is demonstrated using hydrogel functionalised cantilevers. The use of higher order resonance modes sees the sensor dependent mass responsivity enhanced by a factor of 13 in comparison to measurements utilizing the fundamental resonance mode only. As a proof of principle measurement, Aspergillus niger growth is monitored using the first two flexural resonance modes. The detection of single spore growth within 10 h is reported for the first time. The ability to detect and monitor the growth of single spores, within a small time frame, is advantageous in both clinical and industrial settings.
Performance of Variable Energy Cyclotron Centre superconducting cyclotron liquid nitrogen distribution system
Authors: Pal Gautam , Nandi Chinmay , Bhattacharyya Tamal Kumar , Chakrabarti Alok
Published: January 2014

The liquid nitrogen distribution at Variable Energy Cyclotron Centre, Kolkata, India K500 superconducting cyclotron uses parallel branches to cool the thermal shield of helium vessel housing the superconducting coil and the cryopanels. Liquid nitrogen is supplied to the thermal shields from a pressurised liquid nitrogen dewar. Direct measurement of flow is quite difficult and seldom used in an operational cryogenic system. The total flow and heat load of the liquid nitrogen system was estimated indirectly by continuous measurement of level in the liquid nitrogen tanks. A mathematical model was developed to evaluate liquid nitrogen flow in the parallel branches. The model was used to generate flow distribution for different settings and the total flow was compared with measured data.
Experimental realization of a nonlinear acoustic lens with a tunable focus
Authors: Donahue Carly M. , Anzel Paul W. J. , Bonanomi Luca , Keller Thomas A. , Daraio Chiara
Published: January 2014

We realize a nonlinear acoustic lens composed of a two-dimensional array of sphere chains interfaced with water. The chains are able to support solitary waves which, when interfaced with a linear medium, transmit compact pulses with minimal oscillations. When focused, the lens is able to produce compact pressure pulses of high amplitude, the “sound bullets.” We demonstrate that the focal point can be controlled via pre-compression of the individual chains, as this changes the wave speed within them. The experimental results agree well both spatially and temporally with analytical predictions over a range of focus locations.
Radio-frequency reflectometry on an undoped AlGaAs/GaAs single electron transistor
Authors: MacLeod S. J. , See A. M. , Keane Z. K. , Scriven P. , Micolich A. P. , Aagesen M. , Lindelof P. E. , Hamilton A. R.
Published: January 2014

Radio frequency reflectometry is demonstrated in a sub-micron undoped AlGaAs/GaAs device. Undoped single electron transistors (SETs) are attractive candidates to study single electron phenomena, due to their charge stability and robust electronic properties after thermal cycling. However, these devices require a large top-gate, which is unsuitable for the fast and sensitive radio frequency reflectometry technique. Here, we demonstrate that rf reflectometry is possible in an undoped SET.
An x-ray setup to investigate the atomic order of confined liquids in slit geometry
Authors: Lippmann M. , Ehnes A. , Seeck O. H.
Published: January 2014

A setup has been designed to investigate thin films of confined liquids with the use of X-ray scattering methods. The confinement is realized between the flat culets of a pair of diamonds by positioning and orienting the lower diamond with nanometer and micro radian accuracy. We routinely achieve gaps between 5 and 50 nm at culet diameters of 200 μm. With this setup and a micro focused X-ray beam we have investigated the in-plane and the out-off-plane atomic order of benzene with atomic resolution.
(In,Ga)As/GaP electrical injection quantum dot laser
Authors: Heidemann M. , Höfling S. , Kamp M.
Published: January 2014

The paper reports on the realization of multilayer (In,Ga)As/GaP quantum dot (QD) lasers grown by gas source molecular beam epitaxy. The QDs have been embedded in (Al,Ga)P/GaP waveguide structures. Laser operation at 710 nm is obtained for broad area laser devices with a threshold current density of 4.4 kA/cm2 at a heat-sink temperature of 80 K.
Single cell viability observation in cell dielectrophoretic trapping on a microchip
Authors: Huang Chengjun , Liu Chengxun , Loo Josine , Stakenborg Tim , Lagae Liesbet
Published: January 2014

We reported a microfluidic integrated dielectrophoretic (DEP) device for single MCF-7 cell trapping and studied the different effects of applied electric field on the viability of the trapped cell. The cell remained alive when DEP voltage was 3 V. Above 3 V, cell viability significantly decreased when increasing stimulation time. At 8 V, the cell was rapidly lysed by the electric field. The high transmembrane potential induced was found to be the major cause of cell damage. The obtained results indicated that an operational electric field below than 2 kV/cm was safe for cell viability when using DEP for cell manipulation.
Intrinsic device-to-device variation in graphene field-effect transistors on a Si/SiO2 substrate as a platform for discriminative gas sensing
Authors: Lipatov Alexey , Varezhnikov Alexey , Augustin Martin , Bruns Michael , Sommer Martin , Sysoev Victor , Kolmakov Andrei , Sinitskii Alexander
Published: January 2014

Arrays of nearly identical graphene devices on Si/SiO2 exhibit a substantial device-to-device variation, even in case of a high-quality chemical vapor deposition (CVD) or mechanically exfoliated graphene. We propose that such device-to-device variation could provide a platform for highly selective multisensor electronic olfactory systems. We fabricated a multielectrode array of CVD graphene devices on a Si/SiO2 substrate and demonstrated that the diversity of these devices is sufficient to reliably discriminate different short-chain alcohols: methanol, ethanol, and isopropanol. The diversity of graphene devices on Si/SiO2 could possibly be used to construct similar multisensor systems trained to recognize other analytes as well.
Feedback control of torsion balance in measurement of gravitational constant G with angular acceleration method
Authors: Quan Li-Di , Xue Chao , Shao Cheng-Gang , Yang Shan-Qing , Tu Liang-Cheng , Wang Yong-Ji , Luo Jun
Published: January 2014

The performance of the feedback control system is of central importance in the measurement of the Newton's gravitational constant G with angular acceleration method. In this paper, a PID (Proportion-Integration-Differentiation) feedback loop is discussed in detail. Experimental results show that, with the feedback control activated, the twist angle of the torsion balance is limited to \documentclass[12pt]{minimal}\begin{document}$7.3\times 10^{-7}\mathrm{rad/ \sqrt{Hz}}$\end{document}7.3×10−7 rad / Hz at the signal frequency of 2 mHz, which contributes a \documentclass[12pt]{minimal}\begin{document}$0.4\,\textrm {ppm}$\end{document}0.4 ppm uncertainty to the G value.
Deformable silicone grating fabricated with a photo-imprinted polymer mold
Authors: Yamada Itsunari , Nishii Junji , Saito Mitsunori
Published: January 2014

A tunable transmission grating was fabricated by molding a silicone elastomer (polydimethylsiloxane). Its optical characteristics were then evaluated during compression. For fabrication, a glass plate with a photoimprinted polymer grating film was used as a mold. Both the grating period and diffraction transmittance of the molded elastomer were functions of the compressive stress. The grating period changed from 3.02 to 2.86 μm during compressing the elastomer in the direction perpendicular to the grooves.
Palladium nanoparticle decorated silicon nanowire field-effect transistor with side-gates for hydrogen gas detection
Authors: Ahn Jae-Hyuk , Yun Jeonghoon , Choi Yang-Kyu , Park Inkyu
Published: January 2014

A silicon nanowire field-effect transistor (SiNW FET) with local side-gates and Pd surface decoration is demonstrated for hydrogen (H2) detection. The SiNW FETs are fabricated by top-down method and functionalized with palladium nanoparticles (PdNPs) through electron beam evaporation for H2 detection. The drain current of the PdNP-decorated device reversibly responds to H2 at different concentrations. The local side-gates allow individual addressing of each sensor and enhance the sensitivity by adjusting the working region to the subthreshold regime. A control experiment using a non-functionalized device verifies that the hydrogen-sensitivity is originated from the PdNPs functionalized on the SiNW surface.
Photo-induced changes in a hybrid amorphous chalcogenide/silica photonic crystal fiber
Authors: Markos Christos
Published: January 2014

Photostructural changes in a hybrid photonic crystal fiber with chalcogenide nanofilms inside the inner surface of the cladding holes are experimentally demonstrated. The deposition of the amorphous chalcogenide glass films inside the silica capillaries of the fiber was made by infiltrating the nanocolloidal solution-based As25S75, while the photoinduced changes were performed by side illuminating the fiber near the bandgap edge of the formed glass nanofilms. The photoinduced effect of the chalcogenide glass directly red-shifts the transmission bandgap position of the fiber as high as ∼20.6 nm at around 1600 nm wavelength, while the maximum bandgap intensity change at ∼1270 nm was −3 dB.

At the request of the authors and editor, this article is being retracted effective 14 March 2014.
Ultrafast spin tunneling and injection in coupled nanostructures of InGaAs quantum dots and quantum well
Authors: Yang Xiao-Jie , Kiba Takayuki , Yamamura Takafumi , Takayama Junichi , Subagyo Agus , Sueoka Kazuhisa , Murayama Akihiro
Published: January 2014

We investigate the electron-spin injection dynamics via tunneling from an In0.1Ga0.9As quantum well (QW) to In0.5Ga0.5As quantum dots (QDs) in coupled QW-QDs nanostructures. These coupled nanostructures demonstrate ultrafast (5 to 20 ps) spin injection into the QDs. The degree of spin polarization up to 45% is obtained in the QDs after the injection, essentially depending on the injection time. The spin injection and conservation are enhanced with thinner barriers due to the stronger electronic coupling between the QW and QDs.
Giant mechanically-mediated electrocaloric effect in ultrathin ferroelectric capacitors at room temperature
Authors: Liu Yang , Infante Ingrid C. , Lou Xiaojie , Lupascu Doru C. , Dkhil Brahim
Published: January 2014

Using a phenomenological approach, we demonstrate that a giant mechanically-mediated electrocaloric effect can be obtained in ultrathin ferroelectric SrRuO3/BaTiO3/SrRuO3 capacitors at room temperature. Our results show that the electrocaloric properties of such capacitors can be systematically tuned by applying an external stress. The depolarizing field, whose effect is usually ignored in the literature, is found to be detrimental to the electrocaloric response, especially for the thinner films. Moreover, a remarkable enhancement and broadening of the electrocaloric response can be achieved in relatively thick films under compressively loaded conditions compared with the unloaded case.
The x dependent two kinds of resistive switching behaviors in SiOx films with different x component
Authors: Wang Yuefei , Chen Kunji , Qian Xinye , Fang Zhonghui , Li Wei , Xu Jun
Published: January 2014

We discover the transition phenomenon of two kinds of different resistive switching behaviors in SiOx based Pt/SiOx/Pt devices with different x component. When x < 0.80, the forming/set operations need a current compliance and the reset voltage Vreset is lower than set voltage Vset. However, when x > 0.95, the operations do not need a current compliance and Vreset is higher than Vset. We use the silicon dangling bonds (Si-DBs) percolation model to explain the x dependent transition phenomenon. The microstructural transitions of tetrahedral Si-O configurations and related Si-DBs in as-deposited SiOx films with different x and the hopping conductance of low-resistance-states support our model.
Atomic-scale studies on the effect of boundary coherency on stability in twinned Cu
Authors: Niu Rongmei , Han Ke , Su Yi-Feng , Salters Vincent J.
Published: January 2014

The stored energy and hardness of nanotwinned (NT) Cu are related to interaction between dislocations and {111}-twin boundaries (TBs) studied at atomic scales by high-angle annular dark-field scanning transmission electron microscope. Lack of mobile dislocations at coherent TBs (CTBs) provides as-deposited NT Cu a rare combination of stability and hardness. The introduction of numerous incoherent TBs (ITBs) reduces both the stability and hardness. While storing more energy in their ITBs than in the CTBs, deformed NT Cu also exhibits high dislocation density and TB mobility and therefore has increased the driving force for recovery, coarsening, and recrystallization.
Tailoring properties of ferroelectric ultrathin films by partial charge compensation
Authors: Glazkova E. , McCash Kevin , Chang C.-M. , Mani B. K. , Ponomareva I.
Published: January 2014

Partial charge compensation in ferroelectric nanostructures is known to play a critical role in stabilizing equilibrium domain patterns. We use first-principles-based simulations to study the effect of partial charge compensation on the response of polarization to the electric field in PbTiO3 and BaTiO3 ultrathin films. Computational data predict that the response can be altered at the qualitative level by tailoring partial charge compensation. We report an unusual transition from ferroelectric to antiferroelectric to dielectric behavior induced by the change in the amount of compensating charge. Interestingly, films with antiferroelectric features exhibit superior potential for energy storage applications.
Motion Influences the Perception of Background Lightness
Authors: Ashida Hiroshi , Scott-Samuel Nicholas E.
Published: January 2014

Uniform backgrounds appear lighter or darker when elements containing luminance gradients move across them, a phenomenon first presented by Ko Nakamura at the 2010 Illusion Contest in Japan. We measured the apparent lightness of the background with a configuration where the grey background was overlaid with moving square patches of vertically oriented luminance gradient. For black-to-grey gradients, the background appeared lighter when the black edges were leading than when they were trailing. For white-to-grey gradients, the background appeared darker when the white edges were leading than when they were trailing. For white-to-black gradients, the background appeared darker with a white edge leading and lighter with a dark edge leading, but the effects were weaker. These results demonstrate that lightness contrast can be modulated by the direction of motion of the inducing patterns. The smooth gradient is essential, because the effect disappeared when the black-to-white gradient was replaced with the binary black and white pattern. We speculate that asymmetry in the processing of a temporal gradient with increasing and decreasing contrast, as proposed to explain the “Rotating Snakes” illusion (Murakami, Kitaoka, & Ashida, 2006, Vision Research, 46, 2421–2431), might be the basis for this effect.
The Hue of Concepts
Authors: Albertazzi Liliana , Canal Luisa , Malfatti Michela , Micciolo Rocco
Published: January 2014

The study shows a systematic naturally biased association between percepts and concepts. Specifically, it shows that a series of terms pertaining to an abstract semantic field (related to the frame of ethics in social behaviour) has a nonrandom, highly significant, association with colours (hues). This is the first time that consistent associations between abstract terms and colours have been reported in the general population. The main hypothesis, ie that there appear to be ‘hues of concepts’, was borne out by the results: The abstract terms considered were coloured with blue/green (ie cool) colours as well as their synonyms, while their antonyms were coloured with red/yellow (ie warm) colours. The association provides information about the nature of abstract concepts and their relationship with perception. It also sheds light on the interrelations among words in semantic domains that, to date, have been studied from only a computational viewpoint.
Factors affecting reproductive performance of dairy cows in a pasture-based, automatic milking system research farm: a retrospective, single-cohort study
Authors: Talukder S. , Celi P. , Kerrisk K. L. , Garcia S. C. , Dhand N. K.
Published: January 2014

A retrospective, single-cohort study was conducted to identify production and health factors associated with reproductive performance in a pasture-based, automatic milking system research farm. The calving system of this herd shifted from split calving to year-round calving gradually during the study period. Data from 365 cows with 798 lactations were analysed. Reproductive outcome variables of interest were intervals from calving to first oestrus, to first insemination, and to conception, as well as number of inseminations per conception, probability of submission for insemination by 80 days in milk, probability of conception by 100 days in milk and probability of conception at first insemination. Production factors (milk yield and its composition, milking frequency), record of periparturient disease, parity and season of calving were considered as predictor variables. The associations between predictor and outcome variables were assessed by multivariable linear regression, logistic regression and survival analyses, for quantitative, binary and time-to-event outcomes, respectively. Average milk yield and milking frequency during 100 days in milk were not significantly associated with any of the reproductive measures. The likelihood of conception by 100 days in milk decreased gradually with year of automatic milking system commissioning. Cows calved in autumn were 43% (hazard ratio 1.43, P < 0.05) more likely to conceive than cows calved in summer. Multiparous cows were more likely (P < 0.05) to be recorded for oestrus than primiparous cows. Twinning was negatively associated with the reproductive outcomes measured in the automatic milking system research herd. Milk yield and milking frequency during 100 days in milk had no effect on reproductive measures in the pasture-based, automatic milking system research herd.
Flow cytometric and microscopic evaluation of post-thawed ram semen cryopreserved in chemically defined home-made or commercial extenders
Authors: Emamverdi M. , Zhandi M. , Shahneh A. Zare , Sharafi M. , Akhlaghi A. , Motlagh M. Khodaei , Dadkhah F. , Davachi N. Dadashpour
Published: January 2014

The present study was designed to determine the effect of three different extenders on ram sperm quality during a freeze–thawing procedure using flow cytometric and microscopic evaluations. Several in vitro qualitative analyses of post-thawed sperm parameters including motility and velocity parameters, plasma membrane functionality, total abnormality, capacitation status, acrosome integrity, mitochondrial activity and apoptosis features were considered. In the breeding season, seven ejaculates from each Zandi ram were collected routinely twice a week. Following semen collection, samples were pooled and equally divided into three aliquots. Each aliquot was diluted and frozen with one of the following extenders: (1) Tris-based extender containing 1.5% (w/v) soybean lecithin (TSL), as a chemically defined extender, (2) Bioxcell, a commercial soybean lecithin-based extender, and (3) Tris-based extender containing 20% (v/v) egg yolk (TEY). The results of the present study indicated no differences in total [TSL (55.8 ± 2.02%) vs TEY (50.2 ± 2.02%; P < 0.05)] and progressive motility of spermatozoa [TSL (26.2 ± 1.36%) vs Bioxcell (22.4 ± 1.36%; P < 0.05)]. Semen freezing by means of TSL resulted in a higher percentage of live spermatozoa (39.42 ± 1.81%) compared with TEY (29.17 ± 1.81%; P < 0.05), and a higher percentage of functional plasma membrane (50.8 ± 192%) compared with TEY (44 ± 1.92%) and Bioxcell (38.8 ± 1.92%; P < 0.05). The effect of extenders on sperm capacitation status showed that the percentage of post-thawed capacitated spermatozoa was higher in TEY (61.9 ± 1.48%) compared with that in TSL (56.6 ± 1.48%; P < 0.05). The evaluation of post-thawed spermatozoa indicated that the percentage of live spermatozoa with active mitochondria was higher in TSL (53.05 ± 2.31%) compared with Bioxcell (45.92 ± 2.31; P < 0.05) and the percentage of intact acrosome spermatozoa was higher in TSL (84.55 ± 2.51%) compared with TEY (74.91 ± 2.51%; P < 0.05). The use of TSL and Bioxcell extenders reduced the percentage of apoptotic spermatozoa (40.82 ± 2.07% and 42.22 ± 2.07%, respectively), compared with TEY (51.34 ± 2.07%; P < 0.05). Post-thawing dead spermatozoa were increased when semen was frozen by Bioxcell (25.69 ± 1.28%). The results of this study showed that TSL extender may provide stabile milieu and conditions for ram sperm cryopreservation compared with Bioxcell and TEY extenders. Whether TSL extender can improve the artificial insemination results remains, however, an open question.
Cobalt-Mediated Decarboxylative Homocoupling of Alkynyl Carboxylic Acids
Authors: Leeming Michael G. , Khairallah George N. , Osburn Sandra , Vikse Krista , O'Hair Richard A. J.
Published: January 2014

Cobalt-mediated decarboxylative Glaser-like C–C bond coupling of carboxylates has been studied in the gas phase using collision-induced dissociation (CID) multistage mass spectrometry (MSn) experiments. Both the identity of the carboxylate RCO2– (R = Me, HC≡C, MeC≡C, and PhC≡C) and the nuclearity of the complex ([CoCl(O2CR)2]– versus [Co2Cl3(O2CR)2]–) play a role in the types of reactions observed and their relative activation energies. In the first stage of CID, the mononuclear complex [CoCl(O2CMe)2]– undergoes decarboxylation, while the dinuclear [Co2Cl3(O2CMe)2]– undergoes cluster fission to yield [CoCl3]–; all acetylenic carboxylate complexes [CoCl(O2CR)2]– and [Co2Cl3(O2CR)2]– undergo decarboxylation. Isolation of the decarboxylated products followed by a second stage of CID results in a second decarboxylation event for all systems except for [CoCl(Me)(O2CMe)]–, which undergoes bond homolysis. In the final stage of CID, all acetylenic complexes undergo Glaser coupling, forming reduced Co anions. Overall dinuclear cobalt clusters are superior to mononuclear complexes at promoting decarboxylation and reductive coupling. The order of reactivity among the acetylide ligands is PhC≡C > MeC≡C > HC≡C.
The polyploid nature of Cenchrus ciliaris L. (Poaceae) has been overlooked: new insights for the conservation and invasion biology of this species – a review
Authors: Kharrat-Souissi Amina , Siljak-Yakovlev Sonja , Brown Spencer C. , Baumel Alex , Torre Franck , Chaieb Mohamed
Published: January 2014

Climate change, associated with increased aridity, and high grazing pressure by livestock results in the scarcity and loss of perennial Poaceae in arid ecosystems. The species threatened by this include Cenchrus ciliaris L., a native perennial grass of the tropical and sub-tropical arid rangelands of Africa and Western Asia and now introduced in Central and South America, and Australia. This species reproduces predominantly through aposporous apomixis although sexual individuals have been occasionally identified. Cenchrus ciliaris is characterised by a significant, heritable, phenotypic polymorphism and three ploidy levels including tetraploids (2n = 4x = 36), pentaploids (2n = 5x = 45) and hexaploids (2n = 6x = 54). Under water-deficit conditions, C. ciliaris shows plasticity in growth characteristics and aboveground biomass. This phenotypic plasticity has led to the identification of genotypic-associated responses conferring more productivity. This underlines the importance of conserving the genetic diversity of C. ciliaris in order to ensure the persistence of the vegetation cover in the arid ecosystems in which it occurs. Observations from cytogenetic and molecular data converge to underline the possibility of sexual reproduction, recombination and gene flow within and between populations of C. ciliaris. Genetic mechanisms, such as polyploidy, hybridisation between ploidy levels and apomixes, are generating and then maintaining the diversity of C. ciliaris. This review emphasises the role of polyploidy in the evolutionary development of C. ciliaris and how it may be a crucial factor for its conservation in some countries and its weedy nature in others.
Changing Culture, Stable Structure
Authors: Konig Ruben P. , Bardoel Jo L. H.
Published: January 2014

In this contribution we deal with the contradiction between changing culture and stable structure, i.e., the phenomenon that a social structure that developed to accommodate a certain culture may remain stable over a long period of time, even when that culture changes. We do so for the case of the Dutch public broadcasting system, that was designed in the 1920s to fit with the segmented pluralism of Dutch society, in which a number of religiously and ideologically different groups had to peacefully co-exist. In the mid-1960s, Dutch society started to change rapidly and segmented pluralism started to wane. The public broadcasting system, however, hardly changed until today. First we explain how structure and culture initially matched and how the concept of path dependency can explain how over time culture and structure can grow apart. Then, with data of six national surveys between 1979 and 2005, we explore the possible cultural grounds for the fact that the segmented public broadcasting system has outlived the segmented pluralism of Dutch society that it was originally designed to match.
Disease Resistance Against a Broad-Host-Range Pathogen
Authors: Jacobs Jonathan M. , Allen Caitilyn
Published: January 2014

The bacterial wilt pathogen Ralstonia solanacearum causes major agricultural losses on many crop hosts worldwide. Resistance breeding is the best way to control bacterial wilt disease, but the biological basis for bacterial wilt resistance is unknown. We found that R. solanacearum uses an AvrE-family, Type III-secreted effector called PopS to overcome plant defenses and cause disease on tomato. Orthologs of PopS are widely conserved across distinct classes of plant pathogenic bacteria and could provide novel, durable targets for resistance.

Accepted for publication 25 September 2013. Published 25 November 2013.
Awareness and effectiveness of quality function deployment (QFD) in design and build projects in Nigeria
Authors: John Romeo , Smith Andrew , Chotipanich Sarich , Pitt Michael
Published: January 2014

Purpose

– Quality function deployment (QFD) is a method for structured product planning and development that enables a development team to specify clearly the wants and needs of customers. This method has been successfully employed in the construction industry in developed countries. However, the benefits of QFD have not been practically realised in developing countries such as Nigeria. Hence, this research aims to investigate the awareness and effectiveness of QFD as a quality control technique that enhances the satisfaction of clients in terms of quality, cost and project delivery time in design and build projects.

Design/methodology/approach

– A qualitative and quantitative research approach in the form of in-depth telephone interviews and questionnaires was used to obtain the views of construction professionals such as civil engineers, architects, project managers, chief executive officers and trades people involved in design and build projects in the Nigerian construction industry, as well as 50 clients to ascertain the level of satisfaction derived from these design and build projects.

Findings

– The results of this research are derived from statistical analysis and show that there is currently little awareness of QFD within the Nigerian construction industry or its potential effectiveness in design and build projects.

Originality/value

– There has been little previous research into the use of QFD in the Nigerian construction industry, hence this paper provides insight but also highlights the need for further research.
Soil seed bank in a patchy vegetation of coastal sandy plains in southeastern Brazil
Authors: Braz Maria Isabel Guedes , Rodin Patricia , de Mattos Eduardo Arcoverde
Published: January 2014

Large seed banks have been found in tropical dry forests and also in habitats with high seasonality in rainfall. However, patchily structured vegetation could induce great spatial variation in the seed bank. We characterized the seed bank in a patchy vegetation of restinga, a common type of coastal vegetation found in the Atlantic forest biome. We also evaluated whether there is any spatial variation between the litter and soil layer, bare sand, and the edge and center of vegetation patches with distinct species dominance. We found 104 seeds/m2 in the seed bank using a 5‐cm‐depth sampling. Seven out of 16 species found in the restinga seed bank germinated; two of these were found in the early stages of vegetation patches. We found a higher number of seeds at the edge than in the center of vegetation patches. However, there were no significant differences in the number of seeds in the seed bank between the litter and soil layer, and between vegetation patches with distinct species dominance. Bare sandy soils had lower seed bank densities than vegetation patches. A small seed bank size might be explained by the low proportion of seeds from herbaceous and woody species, which are pioneers in the Atlantic forest. However, seed bank might play an important role in the early stages of the successional process, due to the occurrence of the few species that are able to colonize new young vegetation patches.
Biochemical studies on a versatile esterase that is most catalytically active with polyaromatic esters
Authors: Martínez‐Martínez Mónica , Lores Iván , Peña‐García Carlina , Bargiela Rafael , Reyes‐Duarte Dolores , Guazzaroni María‐Eugenia , Peláez Ana Isabel , Sánchez Jesús , Ferrer Manuel
Published: January 2014

Herein, we applied a community genomic approach using a naphthalene‐enriched community (CN1) to isolate a versatile esterase (CN1E1) from the α/β‐hydrolase family. The protein shares low‐to‐medium identity (≤ 57%) with known esterase/lipase‐like proteins. The enzyme is most active at 25–30°C and pH 8.5; it retains approximately 55% of its activity at 4°C and less than 8% at ≥ 55°C, which indicates that it is a cold‐adapted enzyme. CN1E1 has a distinct substrate preference compared with other α/β‐hydrolases because it is catalytically most active for hydrolysing polyaromatic hydrocarbon (phenanthrene, anthracene, naphthalene, benzoyl, protocatechuate and phthalate) esters (7200–21 000 units g−1 protein at 40°C and pH 8.0). The enzyme also accepts 44 structurally different common esters with different levels of enantio‐selectivity (1.0–55 000 units g−1 protein), including (±)‐menthyl‐acetate, (±)‐neomenthyl acetate, (±)‐pantolactone, (±)‐methyl‐mandelate, (±)‐methyl‐lactate and (±)‐glycidyl 4‐nitrobenzoate (in that order). The results provide the first biochemical evidence suggesting that such broad‐spectrum esterases may be an ecological advantage for bacteria that mineralize recalcitrant pollutants (including oil refinery products, plasticizers and pesticides) as carbon sources under pollution pressure. They also offer a new tool for the stereo‐assembly (i.e. through ester bonds) of multi‐aromatic molecules with benzene rings that are useful for biology, chemistry and materials sciences for cases in which enzyme methods are not yet available.
Advanced Interatrial Block is Associated with Recurrence of Atrial Fibrillation Post Pharmacological Cardioversion
Authors: Enriquez Andres , Conde Diego , Hopman Wilma , Mondragon Ignacio , Chiale Pablo A. , de Luna Antoni Bayés , Baranchuk Adrian
Published: January 2014

Introduction

Management of atrial fibrillation (AF) is hampered by frequent recurrences after restoration of sinus rhythm. Delayed interatrial conduction has been associated with the development of AF in different clinical settings. The aim of our study was to assess whether advanced interatrial block (aIAB) was associated with AF recurrence after pharmacological cardioversion with two different antiarrhythmic drugs.

Methods

We included 61 patients with recent onset AF without structural heart disease that underwent successful pharmacological cardioversion. Thirty‐one patients received a single oral dose of propafenone, and 30 patients received iv vernakalant. A 12‐lead ECG (filter 150 Hz, 25 mm/s, 10 mm/mV) after conversion was evaluated for the presence of interatrial block (IAB); partial (pIAB): P‐wave duration > 120 ms, and advanced (aIAB): P‐wave > 120 ms and biphasic morphology (±) in inferior leads. Clinical follow‐up and electrocardiographic recordings were performed for a 12‐month period.

Results

Age was 58 ± 10.4 years and 50.8% were male. aIAB was present in 11 patients (18%) and pIAB in 10 (16.4%). At 1‐year follow‐up, 22 patients (36%) had AF recurrence. The recurrence rate with aIAB was 90.9% versus 70% in those with pIAB and 12.5% in normal P‐wave duration (P = 0.001). The presence of aIAB was strongly associated with AF recurrence (odds ratio 18.4 in multivariable modeling). Recurrence was not affected by the drug used for cardioversion (P = 0.92).

Conclusion

Advanced interatrial block is associated with higher risk of AF recurrence at 1 year after pharmacological cardioversion, independent of the drug used.
Sex differences in interpretation bias in adolescents
Authors: Gluck Rachel L. , Lynn Debra A. , Dritschel Barbara , Brown Gillian R.
Published: January 2014

Interpretation biases, in which ambiguous information is interpreted negatively, have been hypothesized to place adolescent females at greater risk of developing anxiety and mood disorders than same‐aged males. We tested the hypothesis that adolescent girls interpret ambiguous scenarios more negatively, and/or less positively, than same‐aged males using the Adolescent Interpretation and Belief Questionnaire (N = 67, 11–15 years old). We also tested whether adolescent girls and boys differed in judging positive or negative interpretations to be more believable and whether the scenario content (social vs. non‐social) affected any sex difference in interpretation bias. The results showed that girls had higher average negative interpretation scores than boys, with no sex differences in positive interpretation scores. Girls and boys did not differ on which interpretation they found to be most believable. Both sexes reported that positive interpretations were less likely to come to mind, and were less believable, for social than for non‐social scenarios. These results provide preliminary evidence for sex differences in interpretation biases in adolescence and support the hypothesis that social scenarios are a specific source of anxiety to this age group. A greater understanding of the aetiology of interpretation biases will potentially enhance sex‐ and age‐specific interventions for anxiety and mood disorders.
Using risk model judgements to better understand perceptions of synergistic risks
Authors: Dawson Ian G. J. , Johnson Johnnie E. V. , Luke Michelle A.
Published: January 2014

Numerous scientific studies show that risk factors can interact to synergistically increase the likelihood of certain adverse and life‐threatening outcomes. Yet, the extent to which individuals know that specific risk factor combinations present ‘synergistic risks’ is unclear and little is known about the determinants of such knowledge. This is largely because epistemological progress concerning this topic has been frustrated by a reliance on metrics that have latterly been judged to be of questionable validity. To address this issue, this paper presents two studies that assess an alternative approach (i.e., risk model judgements) which requires respondents to judge the risk for a factor combination relative to, rather than in isolation from, the risk attributable to each constituent factor. Results from both studies indicate that risk model judgements overcome the drawbacks of traditional metrics. More importantly, the results provide epistemological insights into what can determine whether an individual understands that a factor combination presents a synergistic risk; these determinants include experiential and intuitive insights into the effects of combining specific risk factors, domain‐specific judgemental experience and exposure to effective learning opportunities. These findings can be utilized in interventions aimed at helping individuals to make better decisions concerning multiple risk factors.