bluuebunny/crossref_metadata_2025 huggingface dataset:
Active faulting induced by slip partitioning in Montserrat and link with volcanic activity: New insights from the 2009 GWADASEIS marine cruise data
Authors: Feuillet Nathalie , Leclerc Frédérique , Tapponnier Paul , Beauducel François , Boudon Georges , Le Friant Anne , Deplus Christine , Lebrun Jean‐Frédéric , Nercessian Alexandre , Saurel Jean‐Marie , Clément Valentin
Published: April 2010

New high‐resolution marine data acquired aboard R/V Le Suroît was used to map active normal faults offshore Montserrat in greater detail. The main faults of the Montserrat‐Havers fault zone have cumulative scarps up to 200 m high, and offset sedimentary layers by hundreds of meters. They are arranged in a right‐stepping, en echelon, trans‐tensional array, which confirms that they accommodate the left‐lateral component of motion resulting from slip partitioning of oblique convergence along the volcanic arc. They cut across Montserrat's recent volcanic complex. Faulting and fissuring exerted control on the position of andesitic domes, which are aligned along the N110°E average fault trend. The ≈10 km‐long fault segments that cross the island could produce damaging, M ≈ 6 events comparable to the shallow, 16 March 1985, Mw∼6.3 earthquake that ruptured a submarine, N140°E striking, left‐lateral fault near Redonda.
Pancreatic cancer spheres are more than just aggregates of stem marker-positive cells
Authors: Gaviraghi Margherita , Tunici Patrizia , Valensin Silvia , Rossi Marco , Giordano Cinzia , Magnoni Letizia , Dandrea Mario , Montagna Licia , Ritelli Rossana , Scarpa Aldo , Bakker Annette
Published: April 2010

Pancreatic cancer stem-like cells are described by membrane expression of CD24, CD44 and ESA (epithelial-specific antigen) and their capacity to grow as spheres in a serum-free medium containing well-defined growth factors. The capacity of a panel of four pancreatic cancer cell lines (PANC-1, CFPAC-1, PancTu-1 and PSN-1) to form spheres was tested. All cell lines with the exception of PancTu-1 developed spheres. Phenotypically, the sphere-growing cells showed an increased in vitro invasion capability. Both gene and protein expressions of markers of metastases [CXCR4 (CXC chemokine receptor 4), OPN (osteopontin) and CD44v6] and components of active hedgehog pathway signalling were assessed. Spheres clearly demonstrated increased expression of the above-mentioned markers when compared with their adherent counterpart. With the aim of identifying a minimum set of markers able to separate cells that have the capacity to form spheres from those incapable of forming spheres, a PCA (principal component analysis) of the multidimensional dataset was performed. Although PCA of the ‘accepted’ stemness genes was unable to separate sphere-forming from sphere-incapable cell lines, the addition of the ‘aggressiveness’ marker CD44v6 allowed a clear differentiation. Moreover, inoculation of the spheres and the adherent cells in vivo confirmed the superior aggressiveness (proliferation and metastasis) of the spheres over the adherent cells. In conclusion, the present study suggests that the sphere-growing cell population is not only composed of cells displaying classical stem membrane markers but also needs CD44v6-positive cells to successfully form spheres. Our results also emphasize the potential therapeutic importance of pathways such as CXCR4 and hedgehog for pancreatic cancer treatment.
Properties of inductively coupled rf Ar/H2 plasmas: Experiment and global model
Authors: Kimura Takashi , Kasugai Hiroki
Published: April 2010

Experiments with a Langmuir probe and optical emission spectroscopy combined with actinometry are carried out in inductively coupled rf (13.56 MHz) Ar/H2 discharges at total pressures of 20 m, 40 m, and 60 mTorr in hydrogen fractions ranging from 0% to 50%. The measured electron energy probability functions (EEPFs), which deviate from the Maxwellian distributions owing to the depletion of high-energy electrons, can be approximated using two temperatures. The electron temperatures, which can be deduced from the slopes of low-energy and high-energy parts of the EEPFs, relatively abruptly increase with increasing the hydrogen fraction in the hydrogen fractions below 10%, whereas the measured electron density markedly decreases with increasing the hydrogen fraction in the hydrogen fractions below 20%. The effective ion mass, which can be estimated from the ion current collected into the probe, markedly decreases with increasing the hydrogen fraction. The density of hydrogen atoms estimated by actinometry markedly increases as molecular hydrogen is added to Ar discharges, and then gradually increases with increasing the hydrogen fraction at the hydrogen fractions higher than 10%–20%. A global model is used to study the effect of Ar dilution to hydrogen discharges on the plasma parameters assuming the Maxwellian electron energy distribution. The model results are compared with the experimental results, obtaining reasonably good agreement.
Application of microevaporators to dynamic exploration of the phase diagram
Authors: Salmon J.-B. , Leng J.
Published: April 2010

We present a detailed investigation of the functioning of microevaporators using numerics and analytical arguments. We first present a way to neatly control stationary gradients of solutes in a microfluidic channel. These gradients display exact exponential or Gaussian shapes depending on a Péclet number (Pe) that compares the mobility of the solute to the convection in the microevaporator. Then, we focus on the regimes of filling where solutes are continuously accumulated toward the tip of the microevaporator, and we give an analytical description on how they concentrate at the tip of the channel depending on Pe; we also evidence and stress the significant role of transient regimes in the mechanisms at work. Finally, we detail how to use these devices to explore dynamically phase diagrams of multicomponent systems.
Accurate reconstruction of the thermal conductivity depth profile in case hardened steel
Authors: Celorrio Ricardo , Apiñaniz Estibaliz , Mendioroz Arantza , Salazar Agustín , Mandelis Andreas
Published: April 2010

The problem of retrieving a nonhomogeneous thermal conductivity profile from photothermal radiometry data is addressed from the perspective of a stabilized least square fitting algorithm. We have implemented an inversion method with several improvements: (a) a renormalization of the experimental data which removes not only the instrumental factor, but the constants affecting the amplitude and the phase as well, (b) the introduction of a frequency weighting factor in order to balance the contribution of high and low frequencies in the inversion algorithm, (c) the simultaneous fitting of amplitude and phase data, balanced according to their experimental noises, (d) a modified Tikhonov regularization procedure has been introduced to stabilize the inversion, and (e) the Morozov discrepancy principle has been used to stop the iterative process automatically, according to the experimental noise, to avoid “overfitting” of the experimental data. We have tested this improved method by fitting theoretical data generated from a known conductivity profile. Finally, we have applied our method to real data obtained in a hardened stainless steel plate. The reconstructed in-depth thermal conductivity profile exhibits low dispersion, even at the deepest locations, and is in good anticorrelation with the hardness indentation test.
Dynamical stability and phase transition of BeO under pressure
Authors: Sahariah Munima B. , Ghosh Subhradip
Published: April 2010

We study the pressure induced phase transitions in BeO at zero and finite temperatures using ab initio density functional perturbation theory. The aim is to primarily focus on the vibrational properties of this alkaline earth oxide under pressure to understand the mechanism of phase transitions. Static calculations predict the B4 to B1 transition to occur at 112 GPa at 0 K. Zero-point vibrations lower this pressure by 7 GPa. Dynamically, the B4 phase is found to be stable up to a pressure of about 820 GPa. On the other hand, the material in its B1 phase cannot be decompressed below 35 GPa. The possible transition path as well as the associated transition mechanism has been investigated from phonon excitations. The P-T stability field of wurtzite (B4) and rocksalt (B1) structure phases of BeO has been discussed using quasiharmonic approximation.
On the deposition mechanisms and the formation of glassy Cu–Zr thin films
Authors: Almyras G. A. , Matenoglou G. M. , Komninou Ph. , Kosmidis C. , Patsalas P. , Evangelakis G. A.
Published: April 2010

We report on molecular dynamics (MD) simulations and physical vapor deposition experimental results concerning the development of glassy and nanocrystalline Cu–Zr thin films. MD has revealed that when Cu and Zr are deposited sequentially, a thin film overlayer is formed that consists of nanocrystalline a-Zr and t-Zr2Cu, while if Cu and Zr are simultaneously deposited, amorphous CuZr thin film emerges, due to the formation of icosahedral-like clusters that impede nucleation. Thin films grown by pulsed laser deposition and magnetron sputtering techniques were analyzed by x-ray diffraction and high-resolution transmission electron microscopy and yielded unequivocal evidence that validates our MD predictions. These findings may indicate an alternative pathway for the growth of metallic nanocomposites or glassy films.
Magnetic properties of nickel hydroxide nanoparticles
Authors: Liu X. H. , Liu W. , Lv X. K. , Yang F. , Wei X. , Zhang Z. D. , Sellmyer D. J.
Published: April 2010

The magnetic properties of 10 nm size Ni(OH)2 nanoparticles prepared by sol-gel method have been studied. The magnetic moments increase with decreasing temperature in a low applied field, which is due to the spin-frozen-like state at low temperatures, and the metamagnetic transition is not clearly observed even in an applied field of 70 kOe due to the size effect. Furthermore, the transition from paramagnetic to antiferromagnetic in the Ni(OH)2 nanoparticles occurs at lower temperature (22 K).
A slender-body theory for low-viscosity drops in shear flow between parallel walls
Authors: Janssen P. J. A. , Anderson P. D. , Loewenberg M.
Published: April 2010

A slender-body analysis is presented for the deformation and break-up of a highly confined and highly elongated low-viscosity drop in shear flow between two parallel walls that are separated by a distance less than the drop length. The analysis is simplified by the assumption that the drop has a circular cross section. The results show that confinement enhances the alignment of a low-viscosity drop with the imposed flow, thereby reducing its deformation and increasing the critical flow strength required for breakup. In the intermediate limit, where the wall separation is small compared with the drop length but large compared with its width, the dynamics can be related to that of an unconfined drop at a shear rate reduced by a factor of 3. Under these corresponding conditions, the drop length and cross-section profile are the same for both cases, whereas the centerline deflection of the confined drop is reduced relative to the unconfined case by 3. In the intermediate limit of wall separations, the critical flow strength for a confined drop is 3 times larger than that for an unconfined drop.
Strong size-dependent photoacoustic effect on gold nanoparticles by laser-induced nanobubbles
Authors: González Martín G. , Liu Xiangjiang , Niessner Reinhard , Haisch Christoph
Published: April 2010

In this paper we propose a mathematical model and an approximate equation to explain the behavior found on the photoacoustic effect generated by laser-induced nanobubbles in colloidal gold solutions. To obtain the equation, we developed a simulation program based on the widely known Rayleigh–Plesset model. A set of measurements was carried out to assess its accuracy on real samples. The equation gives a good approximation for spherical gold nanoparticles with sizes between 10 and 80 nm, and laser fluences larger than the fluence threshold for bubble formation.
Bubble formation via multidrop impacts
Authors: Bick Alexander G. , Ristenpart William D. , van Nierop Ernst A. , Stone Howard A.
Published: April 2010

Gas bubbles are often generated when droplets impact a liquid-air interface. For the impact of single droplets, a critical impact velocity must be exceeded for air to be entrained in the form of bubbles. Here we establish that bubbles can be generated at much lower velocities provided that two or more drops impact the liquid-air interface within a sufficiently short time interval. Using high-speed imaging, we show that bubbles are entrained when a drop lands in the impact crater of a previous drop. We quantify the critical crater depth formed upon impact and the necessary time interval between drop impacts for bubble entrainment to occur. For 1 mm diameter water drops falling at 1 m/s, the critical separation time is approximately 5 ms. This critical time is consistent with a scaling analysis of the time required for an impact crater to close by capillarity.
α
-relaxation dynamics of orientanionally disordered mixed crystals composed of Cl-adamantane and CN-adamantane
Authors: Martinez-Garcia J. C. , Tamarit J. Ll. , Capaccioli S. , Barrio M. , Veglio N. , Pardo L. C.
Published: April 2010

The α-relaxation dynamics of 1-cyano-adamantane (CNA) and its mixtures with 1-chloro-adamantane (ClA) has been studied by means of broadband dielectric spectroscopy. The existence of orientationally disordered (OD) face centered cubic mixed crystals (ClA1−XCNAX) for 0.5≤X≤1 has been put in evidence by thermodynamics and structural analyses. In addition to the OD phase of CNA, mixed crystals with compositions higher than the equimolar one exhibit a freezing of the orientational degrees of freedom into a glassy state, which involves also a strong increase of the antiferroelectric order at temperatures higher than the dielectric glass transition temperature. This experimental evidence is revealed by a stairlike effect in the variation of the Kirkwood factor with the temperature as a consequence of a twin effect in the dielectric strength without any anomaly in the temperature-density curves. The characteristic relaxation times are analyzed as a function of temperature and mole fraction. By setting a common temporal origin (“isochronal origin”) at τ(Tg)=100 s for each mole fraction, it emerges that the substitution of ClA molecules by those of CNA (diminution of X) gives rise to a slow down in the dynamics, despite that the molecular volume of ClA molecules are smaller than those of CNA. This fact goes along and is accompanied by a diminution of the lattice packing with the decrease of composition. It is also shown that the heterogeneities produced by the concentration fluctuations due to the chemical disorder are the main contribution to the non-exponential character of the α-relaxation peaks.
Temporal evolution of neoclassical tearing modes in the frequently interrupted regime
Authors: Dumbrajs O. , Igochine V. , Gude A. , Maraschek M. , Zohm H. ,   ASDEX Upgrade Team
Published: April 2010

A phenomenological method for description of temporal evolution of neoclassical tearing modes in the frequently interrupted regime (FIR) is proposed. The method makes it possible to predict the beginning and the end of the FIR regime as well as the frequency of the FIR drops. A few experimental parameters which are used in the model are commonly measured quantities. Several specific ASDEX Upgrade (http://en.wikipedia.org/wiki/ASDEX_Upgrade) FIR discharges with different heating and different FIR behavior are analyzed in detail.
On the quasiperiodic state in a moderate aspect ratio Taylor–Couette flow
Authors: Imomoh E. , Dusting J. , Balabani S.
Published: April 2010

The transition pathway leading to chaotic flow in a Taylor–Couette vessel of aspect ratio γ=11.2 and radius ratio η=0.81 with only the inner cylinder rotating has been studied using time-resolved particle image velocimetry. A hitherto unreported sequence of transitions, whereby the flow changes from wavy vortex flow to a quasiperiodic state of high modulation frequency, is identified using spatially resolved spectral analysis. The nature of the modulated wavy vortex flow is detailed using proper orthogonal decomposition, through which it is revealed that the modulation is similar to a fast moving azimuthal wave (FMAW). In contrast with previous observations of the FMAW at a much higher aspect ratio, the mode appears directly after wavy vortex flow and as a precursor to the CVF regime. The FMAW is also associated with codirectional vorticity fluctuations on each Taylor vortex core that diminish in strength close to the endwalls.
Large thermoelectric figure of merit in Si1−xGex nanowires
Authors: Shi Lihong , Yao Donglai , Zhang Gang , Li Baowen
Published: April 2010

By using first-principles electronic structure calculation and Boltzmann transport equation, we investigate composition effects on the thermoelectric properties of silicon-germanium (Si1−xGex) nanowires (NWs). The power factor and figure of merit in n-type Si1−xGex wires are much larger than those in their p-type counterparts with the same Ge content and doping concentration. Moreover, the maximal obtainable figure of merit can be increased by a factor of 4.3 in n-type Si0.5Ge0.5 NWs, compared with the corresponding values in pure silicon nanowires (SiNWs). Given the fact that the measured ZT of n-type SiNW is 0.6∼1.0, we expect ZT value of n-type Si1−xGex NWs to be 2.5∼4.0.
Effect of human β-globin bacterial artificial chromosome transgenesis on embryo cryopreservation in mouse models
Authors: Boonkusol Duangjai , Dinnyes Andras , Faisaikarm Tassanee , Sangsuwan Parisatcha , Pratipnatalang Nathnapith , Sa-ardrit Mayurachat , Saikhun Kulnasan , Svasti Saovaros , Vadolas Jim , Winichagoon Pranee , Fucharoen Suthat , Kitiyanant Yindee
Published: April 2010

The purpose of the present study was to investigate the efficiency of embryo cryopreservation for four transgenic (TG) thalassaemic mouse strains, which is a key element of the ongoing gene banking efforts for these high-value animals. Heterozygous TG embryos were produced by breeding four lines of TG males to wild-type (WT) females (C57BL/6J). Intact two-cell embryos were cryopreserved by vitrification in straws using 35% ethylene glycol. Survival rates of cryopreserved embryos ranged between 91.1% (102/112) and 93.6% (176/188) without significant differences between the lines. In contrast, the paternal line had a significant effect on the development of these embryos to the blastocyst stage, which ranged from 50.6% (92/182) to 77.5% (79/102). This effect was also noted following embryo transfers, with implantation rates varying from 17.3% (19/110) to 78.1% (35/45). The results demonstrate that the in vivo developmental potential is significantly influenced by TG line and reveal a specific line effect on cryosurvival. All bacterial artificial chromosome transgenic fetuses developed from vitrified–warmed embryos showed expression of the human β-globin transgene. In conclusion, the present study shows a strong TG line effect on developmental competence following cryopreservation and the vitrification method was successful to bank the human β-globin TG-expressing mouse strains.
Meiotic progression, mitochondrial features and fertilisation characteristics of porcine oocytes with different G6PDH activities
Authors: Egerszegi István , Alm Hannelore , Rátky József , Heleil Bassiouni , Brüssow Klaus-Peter , Torner Helmut
Published: April 2010

The aim of the present study was to investigate the developmental competence, mitochondrial characteristics and chromatin status of immature follicular porcine oocytes selected for their glucose-6-phosphate dehydrogenase (G6PDH) activity by brilliant cresyl blue (BCB) staining. In Experiment 1, the oocyte parameters were determined in parallel right after BCB staining (T0), after 22 h of in vitro maturation (IVM) (T22) and after 44 h of IVM (T44) (n = 496). BCB-stained oocytes (BCB+) at T0 were characterised by fibrillated chromatin filaments in their germinal vesicles (GV) and diakinesis stages whereas unstained (BCB–) oocytes at T0 contained in their GV mainly condensed stages of chromatin (P < 0.05). After 22 h of IVM BCB+ oocytes showed a prominent chromatin configuration of metaphase I and after 44 h the majority developed a M II nuclear configuration in contrast to the BCB– group (P < 0.0001). Differences were also observed between the two oocyte populations in their mitochondrial activity (P < 0.05). At the beginning of IVM BCB+ oocytes were characterised by high mitochondrial activity in their cytoplasm. The BCB+ oocytes showed clear visible homogenous distributions of mitochondria (P < 0.005) and contained more aggregated clusters of mitochondria in contrast to BCB– oocytes (P < 0.005). In Experiment 2, 318 oocytes were tested for their G6PDH activity and introduced to IVM and IVF. Only oocytes from the BCB+ group, which were matured after 44 h up to the stage of M II (81.6%) were fertilised (17.4%), penetrated (46%) or activated (15.6%) after IVF. These results indicate a relationship between the G6PDH activity of porcine oocytes before IVM and their subsequent nuclear development, mitochondrial activity and aggregation.
Clock gene expression in gravid uterus and extra-embryonic tissues during late gestation in the mouse
Authors: Ratajczak Christine K. , Herzog Erik D. , Muglia Louis J.
Published: April 2010

Evidence in humans and rodents suggests the importance of circadian rhythmicity in parturition. A molecular clock underlies the generation of circadian rhythmicity. While this molecular clock has been identified in numerous tissues, the expression and regulation of clock genes in tissues relevant to parturition is largely undefined. Here, the expression and regulation of the clock genes Bmal1, Clock, cryptochrome (Cry1/2) and period (Per1/2) was examined in the murine gravid uterus, placenta and fetal membranes during late gestation. All clock genes examined were expressed in the tissues of interest throughout the last third of gestation. Upregulation of a subset of these clock genes was observed in each of these tissues in the final two days of gestation. Oscillating expression of mRNA for a subset of the examined clock genes was detected in the gravid uterus, placenta and fetal membranes. Furthermore, bioluminescence recording on explants from gravid Per2::luciferase mice indicated rhythmic expression of PER2 protein in these tissues. These data demonstrate expression and rhythmicity of clock genes in tissues relevant to parturition indicating a potential contribution of peripheral molecular clocks to this process.
Selenium in blood, semen, seminal plasma and spermatozoa of stallions and its relationship to sperm quality
Authors: Bertelsmann H. , Keppler S. , Höltershinken M. , Bollwein H. , Behne D. , Alber D. , Bukalis G. , Kyriakopoulos A. , Sieme H.
Published: April 2010

The essential trace element selenium is indispensable for male fertility in mammals. Until now, little data existed regarding the relationship between selenium and sperm quality in the stallion. Selenium, or selenium-dependent glutathione peroxidase activity, was determined in red blood cells, semen, seminal plasma and spermatozoa, and the percentages of spermatozoa with progressive motility (PMS), intact membranes (PMI), altered (positive) acrosomal status (PAS) and detectable DNA damage, determined by the sperm chromatin structure assay, were evaluated in 41 healthy stallions (three samples each). The pregnancy rate per oestrus cycle (PRC) served as an estimation of fertility. An adverse effect on stallion fertility caused by low dietary selenium intake was excluded, as all stallions had sufficient selenium levels in their blood. Interestingly, no significant correlations (P > 0.05) between the selenium level in blood and the selenium level in seminal plasma or spermatozoa were found, suggesting that the selenium level in blood is no indicator of an adequate selenium supply for spermatogenesis. The selenium level in spermatozoa (nmol billion–1) was correlated with PMI, PMS and PAS (r = 0.40, r = 0.31 and r = –0.42, respectively; P ≤ 0.05), and the selenium concentration in spermatozoa (nmol g–1) was correlated with PRC (r = 0.40, P < 0.03). The results of the present study show that the determination of an adequate selenium status for the male equine reproduction requires the analysis of selenium in spermatozoa. Furthermore, selenium is associated with improved sperm quality and fertility in the stallion.
Trehalose Is a Key Determinant of the Quiescent Metabolic State That Fuels Cell Cycle Progression upon Return to Growth
Authors: Shi Lei , Sutter Benjamin M. , Ye Xinyue , Tu Benjamin P.
Published: April 2010

When conditions are unfavorable, virtually all living cells have the capability of entering a resting state termed quiescence or G0. Many aspects of the quiescence program as well as the mechanisms governing the entry and exit from quiescence remain poorly understood. Previous studies using the budding yeast Saccharomyces cerevisiae have shown that upon entry into stationary phase, a quiescent cell population emerges that is heavier in density than nonquiescent cells. Here, we show that total intracellular trehalose and glycogen content exhibits substantial correlation with the density of individual cells both in stationary phase batch cultures and during continuous growth. During prolonged quiescence, trehalose stores are often maintained in favor over glycogen, perhaps to fulfill its numerous stress-protectant functions. Immediately upon exit from quiescence, cells preferentially metabolize trehalose over other fuel sources. Moreover, cells lacking trehalose initiate growth more slowly and frequently exhibit poor survivability. Together, our results support the view that trehalose, which is more stable than other carbohydrates, provides an enduring source of energy that helps drive cell cycle progression upon return to growth.
Ribosome-binding Proteins Mdm38 and Mba1 Display Overlapping Functions for Regulation of Mitochondrial Translation
Authors: Bauerschmitt Heike , Mick David U. , Deckers Markus , Vollmer Christine , Funes Soledad , Kehrein Kirsten , Ott Martin , Rehling Peter , Herrmann Johannes M.
Published: April 2010

Biogenesis of respiratory chain complexes depends on the expression of mitochondrial-encoded subunits. Their synthesis occurs on membrane-associated ribosomes and is probably coupled to their membrane insertion. Defects in expression of mitochondrial translation products are among the major causes of mitochondrial disorders. Mdm38 is related to Letm1, a protein affected in Wolf-Hirschhorn syndrome patients. Like Mba1 and Oxa1, Mdm38 is an inner membrane protein that interacts with ribosomes and is involved in respiratory chain biogenesis. We find that simultaneous loss of Mba1 and Mdm38 causes severe synthetic defects in the biogenesis of cytochrome reductase and cytochrome oxidase. These defects are not due to a compromised membrane binding of ribosomes but the consequence of a mis-regulation in the synthesis of Cox1 and cytochrome b. Cox1 expression is restored by replacing Cox1-specific regulatory regions in the mRNA. We conclude, that Mdm38 and Mba1 exhibit overlapping regulatory functions in translation of selected mitochondrial mRNAs.
Role of Hsp90 in Biogenesis of the β-Cell ATP-sensitive Potassium Channel Complex
Authors: Yan Fei-Fei , Pratt Emily B. , Chen Pei-Chun , Wang Fang , Skach William R. , David Larry L. , Shyng Show-Ling
Published: April 2010

The pancreatic β-cell ATP-sensitive potassium (KATP) channel is a multimeric protein complex composed of four inwardly rectifying potassium channel (Kir6.2) and four sulfonylurea receptor 1 (SUR1) subunits. KATP channels play a key role in glucose-stimulated insulin secretion by linking glucose metabolism to membrane excitability. Many SUR1 and Kir6.2 mutations reduce channel function by disrupting channel biogenesis and processing, resulting in insulin secretion disease. To better understand the mechanisms governing KATP channel biogenesis, a proteomics approach was used to identify chaperone proteins associated with KATP channels. We report that chaperone proteins heat-shock protein (Hsp)90, heat-shock cognate protein (Hsc)70, and Hsp40 are associated with β-cell KATP channels. Pharmacologic inhibition of Hsp90 function by geldanamycin reduces, whereas overexpression of Hsp90 increases surface expression of wild-type KATP channels. Coimmunoprecipitation data indicate that channel association with the Hsp90 complex is mediated through SUR1. Accordingly, manipulation of Hsp90 protein expression or function has significant effects on the biogenesis efficiency of SUR1, but not Kir6.2, expressed alone. Interestingly, overexpression of Hsp90 selectively improved surface expression of mutant channels harboring a subset of disease-causing SUR1 processing mutations. Our study demonstrates that Hsp90 regulates biogenesis efficiency of heteromeric KATP channels via SUR1, thereby affecting functional expression of the channel in β-cell membrane.
GLMM-based modelling of growth in juvenile Octopus maya siblings: does growth depend on initial size?
Authors: Briceño Felipe , Mascaró Maite , Rosas Carlos
Published: April 2010

Briceño, F., Mascaró, M., and Rosas, C. 2010. GLMM-based modelling of growth in juvenile Octopus maya siblings: does growth depend on initial size? – ICES Journal of Marine Science, 67: 1509–1516. In most studies on cephalopod growth, variability in initial size is masked by the assumption of a similar growth “starting point” for all hatchlings and by calculating the growth rate (GR) through modelling the average size of individuals through time. Statistical interpretations based on such models are limited because regression assumptions (e.g. homoscedasticity and independence between subjects) are frequently violated. To avoid these limitations, generalized linear mixed modelling was used to model the early growth of two sets of siblings of the holobenthic octopus Octopus maya under controlled conditions. The aim was to (i) determine the effect of initial weight (IW) on the GR of individuals grouped in three size categories (small, medium, and large), (ii) obtain statistically reliable estimates of parameters in an exponential growth model for juveniles up to 105 d old, and (iii) evaluate the influence of hatching date on weight at hatching. Using restricted maximum likelihood, linear models were fitted between (i) IW and final weight (FW) for octopuses in each size category, and (ii) the natural logarithm of IW as a function of time. The models were validated by visually inspecting the residuals. Individual FW depended on IW, but GR did not differ between juveniles of different sizes. The exponential growth model for individuals of all size categories was, with εi ∼ N(0,σ2 [agei]2δ). Hatching date had no effect on hatching size (F = 1.93; p = 0.11). The GR value is similar to those reported for other holobenthic species, and one of the first estimates of the magnitude (δ = 0.20) and structure of the increase in variance of individual weight through time is provided.
Emerging diseases in Chiroptera: why bats?
Authors: Wibbelt Gudrun , Moore Marianne S. , Schountz Tony , Voigt Christian C.
Published: April 2010

A conference entitled ‘2nd International Berlin Bat Meeting: Bat Biology and Infectious Diseases’ was held between the 19 and 21 of February 2010 in Berlin, Germany. Researchers from two major disciplines, bat biologists and disease specialists, met for the first time in an interdisciplinary event to share their knowledge about bat-associated diseases. The focus of the meeting was to understand why in particular bats are the hosts of so many of the most virulent diseases globally. During several sessions, key note speakers and participants discussed infectious diseases associated with bats, including viral diseases caused by Henipa-, Filo-, Corona- and Lyssaviruses, the spread of white-nose syndrome in North American bats, bat immunology/immunogenetics, bat parasites, and finally, conservation and human health issues.
Eye contact enhances mimicry of intransitive hand movements
Authors: Wang Yin , Newport Roger , Hamilton Antonia F. de C.
Published: April 2010

When two people meet in a bar, a subtle interplay of social behaviours, including eye contact and unconscious mimicry of actions play an important role in how much the individuals like each other by the end of the evening. However, it is not known how these different social signals interact. Here, we adopt a rapid mimicry paradigm, to test if eye contact can modulate mimicry on a second by second time scale. Our results show that direct eye contact rapidly and specifically enhances mimicry of hand actions. These findings have implications for understanding the role of eye contact as a controlling signal in human non-verbal social behaviour.
The evolution of sex-specific grandparental harm
Authors: Rice William R. , Gavrilets Sergey , Friberg Urban
Published: April 2010

Recent empirical studies indicate that grandparents favour some categories of grandchildren over others. Here, we expand the previous theoretical foundation for this finding and show that grandchild-harming phenotypes are predicted to evolve by ‘sexually antagonistic zygotic drive (SA-zygotic drive) of the sex chromosomes’. We use the logic of Hamilton's rule to develop a new ‘no-cost-to-self nepotism rule’ that greatly simplifies the determination of the invasion criteria for mutations that cause grandparents to harm grandchildren. We use this theory to generate predictions that distinguish SA-zygotic drive from theory based solely on paternity assurance. The major diagnostic prediction is that grandmothers, and to a lesser degree grandfathers, will evolve grandson-harming phenotypes that reduce the level of sib competition experienced by their more closely related granddaughters, especially in their sons' families. This prediction is supported by data from recent studies showing (i) grandmothers invest more in granddaughters than grandsons, and counterintuitively, (ii) paternal grandmothers reduce the survival of their grandsons. We conclude that SA-zygotic drive is plausibly operating in humans via sexually antagonistic grandparental care.
Oestrous red deer hinds prefer male roars with higher fundamental frequencies
Authors: Reby David , Charlton Benjamin D. , Locatelli Yann , McComb Karen
Published: April 2010

Across vertebrates, the observation that lower-pitched vocalizations are typically associated with larger and/or higher quality males has lead to the widespread belief that inter- and intra-sexual selection will produce male calls with low fundamental frequencies (F0). Here we investigated the response of oestrous red deer hinds to playback of re-synthesized male roars characterized by either higher than average or lower than averageF0. We found that hinds prefer higher rather than lower ‘pitched’ roars, providing, to our knowledge, the first evidence of such a bias in nonhuman mammals. Our findings can be interpreted in relation to previous observations that the minimumF0 of roars is positively correlated with male reproductive success in free-ranging red deer stags, and that across Cervids theF0 of male mating calls shows extreme variability. Females showing preferences for higher-pitched roars might derive genetic benefits through more competitive male offspring. Our results emphasize the need for further investigations of female preferences in mammals in order to better understand the extreme variation ofF0 values observed in male sexual calls.
The N-terminus of Bunyamwera orthobunyavirus NSs protein is essential for interferon antagonism
Authors: van Knippenberg Ingeborg , Carlton-Smith Charlie , Elliott Richard M.
Published: April 2010

Bunyamwera virus NSs protein is involved in the inhibition of cellular transcription and the interferon (IFN) response, and it interacts with the Med8 component of Mediator. A spontaneous mutant of a recombinant NSs-deleted Bunyamwera virus (rBUNdelNSs2) was identified and characterized. This mutant virus, termed mBUNNSs22, expresses a 21 aa N-terminally truncated form of NSs. Like rBUNdelNSs2, mBUNNSs22 is attenuated in IFN-deficient cells, and to a greater extent in IFN-competent cells. Both rBUNdelNSs2 and mBUNNSs22 are potent IFN inducers and their growth can be rescued by depleting cellular IRF3. Strikingly, despite encoding an NSs protein that contains the Med8 interaction domain, mBUNNSs22 fails to block RNA polymerase II activity during infection. Overall, our data suggest that both the interaction of NSs with Med8 and a novel unidentified function of the NSs N-terminus, seem necessary for Bunyamwera virus to counteract host antiviral responses.
Evidence for hippocampus-dependent contextual learning at postnatal day 17 in the rat
Authors: Foster Jennifer A. , Burman Michael A.
Published: April 2010

Long-term memory for fear of an environment (contextual fear conditioning) emerges later in development (postnatal day; PD 23) than long-term memory for fear of discrete stimuli (PD 17). As contextual, but not explicit cue, fear conditioning relies on the hippocampus; this has been interpreted as evidence that the hippocampus is not fully developed until PD 23. Alternatively, the hippocampus may be functional prior to PD 23, but unable to cooperate with the amygdala for fearful learning. The current experiments investigate this by separating the phases of conditioning across developmental stages. Rats were allowed to learn about the context on one day and to form the fearful association on another. Rats exposed to the context on PD 17 exhibited significant fear only when trained and tested a week later (PD 23, 24), but not on consecutive days (PD 18, 19), demonstrating that rats can learn about a context as early as PD 17. Further experiments clarify that it is associative mechanisms that are developing between PD 18 and 23. Finally, the hippocampus was lesioned prior to training to ensure the task is being solved in a hippocampus-dependent manner. These data provide compelling evidence that the hippocampus is functional for contextual learning as early as PD 17, however, its connection to the amygdala or other relevant brain structures may not yet be fully developed.
A Dibasic Amino Acid Pair Conserved in the Activation Loop Directs Plasma Membrane Localization and Is Necessary for Activity of Plant Type I/II Phosphatidylinositol Phosphate Kinase
Authors: Mikami Koji , Saavedra Laura , Hiwatashi Yuji , Uji Toshiki , Hasebe Mitsuyasu , Sommarin Marianne
Published: April 2010

Phosphatidylinositol phosphate kinase (PIPK) is an enzyme involved in the regulation of cellular levels of phosphoinositides involved in various physiological processes, such as cytoskeletal organization, ion channel activation, and vesicle trafficking. In animals, research has focused on the modes of activation and function of PIPKs, providing an understanding of the importance of plasma membrane localization. However, it still remains unclear how this issue is regulated in plant PIPKs. Here, we demonstrate that the carboxyl-terminal catalytic domain, which contains the activation loop, is sufficient for plasma membrane localization of PpPIPK1, a type I/II B PIPK from the moss Physcomitrella patens. The importance of the carboxyl-terminal catalytic domain for plasma membrane localization was confirmed with Arabidopsis (Arabidopsis thaliana) AtPIP5K1. Our findings, in which substitution of a conserved dibasic amino acid pair in the activation loop of PpPIPK1 completely prevented plasma membrane targeting and abolished enzymatic activity, demonstrate its critical role in these processes. Placing our results in the context of studies of eukaryotic PIPKs led us to conclude that the function of the dibasic amino acid pair in the activation loop in type I/II PIPKs is plant specific.
Neutropenia dynamics in a case of T‐LGL lymphoproliferation illustrate rapid turnover of granulocyte progenitors
Authors: Wolfrom C. M. , Lévy V. , Deschatrette J.
Published: April 2010

Objectives:  To elucidate the natural history of T‐cell large granular lymphocyte (T‐LGL) lymphoproliferation, we followed changes in associated fluctuating neutropenia for 3 years in an untreated patient presenting with the disease.

Materials and methods:  We report a nonlinear mathematical analysis of irregular neutrophil fluctuation, using iterative data maps, to detect long‐term regulation of the neutrophil population.

Results:  This geometric analysis indicated that variations of this sequence of neutrophil counts followed bounded deterministic dynamics around a fixed low level equilibrium, a situation similar to that previously observed for cultured mouse early bone marrow progenitor cells.

Conclusion:  These findings illustrate how the deleterious effect of T‐LGL on neutrophils is balanced, over periods of years, by pulses of compensatory neutrophil production, potentially accounting for the commonly observed prolonged indolent course of the disease.
Impact of cross‐reactive carbohydrate determinants on wood dust sensitization
Authors: Kespohl S. , Schlünssen V. , Jacobsen G. , Schaumburg I. , Maryska S. , Meurer U. , Brüning T. , Sigsgaard T. , Raulf‐Heimsoth M.
Published: April 2010

Background
Occupational wood dust exposure can induce allergy and may be one cause of respiratory health problems among woodworkers.

Objective
The objective was to determine the prevalence and quantitative level of specific immunoglobulin E (sIgE) to beech and pine wood in exposed workers. Wood sensitization was specified with regard to cross‐reactivity and was correlated to the reported symptoms.

Methods
Danish workers (n=701) were investigated for sIgE to beech and pine. Wood samples from workplaces were analysed and coupled to ImmunoCAPs. Workers sensitized to wood were tested for cross‐reactive carbohydrate determinants (CCDs) and environmental allergens. IgE binding was specified for glycogenic vs. proteinogenic epitopes by inhibition tests.

Results
The prevalence of wood sensitization among all workers was 3.7%. There was no association between sensitization prevalence or sIgE concentrations and self‐reported allergic symptoms. Beech‐ and pine‐sensitized workers showed a high prevalence of CCD sensitization (73%). However, workers with a single sensitization to wood had no sIgE to CCDs. Specifying IgE epitopes demonstrated that sera of workers reporting allergic symptoms recognized proteinogenic IgE‐epitopes on wood allergens, whereas workers without allergic symptoms had primarily sIgE‐epitopes to glycogenic structures. Although 96% of the wood‐sensitized workers were atopic, no significant correlation was found between wood sensitization and sIgE to beech and birch pollen, but an association was found between sIgE against CCDs and pine pollen.

Conclusion
Sensitization prevalence to beech and pine wood measured by tailored ImmunoCAPs was not correlated to allergic symptoms. We recommend the application of CCD tools to assess the relevance of individual wood sensitization.

Cite this as: S. Kespohl, V. Schlünssen, G. Jacobsen, I. Schaumburg, S. Maryska, U. Meurer, T. Brüning, T. Sigsgaard and M. Raulf‐Heimsoth, Clinical & Experimental Allergy, 2010 (40) 1099–1106.
Beclomethasone dipropionate blunts allergen‐induced early increase in urinary LTE4
Authors: Bartoli Maria Laura , Dente Federico Lorenzo , Bancalari Lorenza , Bacci Elena , Cianchetti Silvana , Di Franco Antonella , Vagaggini Barbara , Paggiaro Pier Luigi
Published: April 2010

Eur J Clin Invest 2010; 40 (6): 566–569

Background  The inhibitory effect of corticosteroids (CS) on the secretions of cysteinyl‐leukotrienes (Cys‐LTs) in asthma is controversial. The aim of this study was to evaluate the effect of CS on allergen‐induced increase in urinary leukotriene E4 (uLTE4) during early (EAR) and late (LAR) asthmatic responses in mild untreated asthmatics.

Material and methods  Nine subjects with mild untreated allergic asthma performed two allergen challenges, after 1‐week treatment with beclomethasone dipropionate (BDP, 500 μg b.i.d) or placebo. Forced Expiratory Volume in one second 1 (FEV1) was monitored to assess EAR and LAR, and uLTE4 was measured before and during EAR and LAR.

Results  After placebo, uLTE4 increased significantly during EAR, but not during and after LAR, in comparison with baseline values. Beclomethasone dipropionate induced a significant attenuation of the uLTE4 increase during EAR, in comparison with placebo, in association with a good protection of LAR (P = 0·002) and a mild protection of EAR (P = 0·07).

Conclusions  Beclomethasone dipropionate blunts the early increase in uLTE4 excretion due to allergen challenge, in association with a significant effect on the severity of LAR. These data support the hypothesis that inhaled CS may inhibit the allergen‐induced release of cys‐LTs in asthma.
Endocrine tumours of the pancreas
Authors: Verbeke Caroline S
Published: April 2010

Verbeke C S  (2010) Histopathology 56, 669–682 Endocrine tumours of the pancreas

Histopathology reporting of pancreatic endocrine neoplasms is complex. The tumours can exhibit a variety of morphological appearances, which often require careful differential diagnostic consideration. Prediction of tumour behaviour and clinical outcome is based on the World Health Organization classification and TNM staging and grading system, which share some criteria and premises, but differ significantly in others. Clinicopathological correlation through discussion at multidisciplinary team meetings is of paramount importance. In this review special emphasis is given to the items of information that can and should be provided by the pathologist to allow optimal patient management. The review further discusses areas of current controversy and uncertainty, of which pathologists participating in multidisciplinary discussions should be aware.
HER2 assessment on core biopsy specimens using monoclonal antibody CB11 accurately determines HER2 status in breast carcinoma
Authors: Purdie Colin A , Jordan Lee B , McCullough Jean B , Edwards Sharon L , Cunningham Joan , Walsh Miriam , Grant Andrew , Pratt Norman , Thompson Alastair M
Published: April 2010

Purdie C A, Jordan L B, McCullough J B, Edwards S L, Cunningham J, Walsh M, Grant A, Pratt N & Thompson A M (2010) Histopathology 56, 702–707 HER2 assessment on core biopsy specimens using monoclonal antibody CB11 accurately determines HER2 status in breast carcinoma

Aims:  HER2 status is a prognostic factor in breast carcinoma and predicts response to trastuzumab therapy. Trastuzumab is effective in the neoadjuvant, adjuvant and advanced disease settings. Knowledge of HER2 status early in the diagnostic and therapeutic process is vital for treatment planning. HER2 analysis is usually carried out by immunohistochemistry or fluorescence in situ hybridization (FISH). The aim of this study was to establish whether HER2 immunohistochemistry using monoclonal antibody CB11 and carried out on the initial diagnostic core biopsy specimen accurately predicts HER2 amplification status.

Methods and results:  This is the largest study to date in which HER2 protein expression has been assessed by CB11 immunohistochemistry on the diagnostic core biopsy specimen and correlated with the result of FISH. Using FISH as the definitive HER2 status, we studied 568 invasive breast cancers using CB11 immunohistochemistry on core biopsy. This analysis had a sensitivity of 99.4%, specificity of 93.9%, false‐positive frequency of 3.9% and false‐negative frequency of 1.1%. These data are as good as those obtained from analysing resection specimens alone in UK national reference centres.

Conclusions:  CB11 immunohistochemistry accurately predicts HER2 amplification status and can be reliably carried out on core biopsy specimens of breast carcinoma.