bluuebunny/crossref_metadata_2025 huggingface dataset:
Proteomics analysis of plasma for potential biomarkers in the diagnosis of Alzheimer's disease
Authors: Liao Pao‐Chi , Yu Lung , Kuo Chih‐Chieh , Lin Chingju , Kuo Yu‐Min
Published: April 2007

The objective of this study was to search for biological markers associated with Alzheimer's disease (AD). Plasma specimens obtained from ten pathologically diagnosed AD patients and ten non‐demented (ND) control subjects were analyzed by a combination of 2‐DE and MS. This strategy allowed us to identify six plasma proteins (alpha‐1‐antitrypsin, vitamin D‐binding protein, inter‐alpha‐trypsin inhibitor family heavy chain‐related protein, apolipoprotein J precursor, cAMP‐dependent protein kinase catalytic subunit alpha 1, and an orf) whose 2‐DE spot densities were different between the AD and ND groups. Due to their involvements in AD amyloid plaque formation, the plasma concentrations of alpha‐1‐antitrypsin and apolipoprotein J were further validated using either ELISA or Western blot. The results revealed that the plasma levels of alpha‐1‐antitrypsin in AD were higher than those of controls, confirming the 2‐DE findings. However, no difference in total apolipoprotein J concentration was observed between the AD and ND groups. Considering the difference in resolving power to differentially quantitate protein isoforms provided by 2‐DE and Western blot, 2‐DE analysis combined with MS protein identification offers distinctive advantages when a disease‐related protein isoform‐specific variance is investigated.
A native antigen “reverse capture” microarray platform for autoantibody profiling of prostate cancer sera
Authors: Ehrlich Joshua R. , Caiazzo Robert J. , Qiu Weiliang , Tassinari Oliver W. , O'Leary Michael P. , Richie Jerome P. , Liu Brian C.‐S.
Published: April 2007

Cancer sera contain antibodies that react with autologous cellular antigens. Here, we report the use of a novel native antigen‐based platform, the “reverse capture” autoantibody microarray, for identification of autoantigens against which autoantibody expression may be used to differentiate between patients with prostate cancer and benign prostate hyperplasia (BPH). Serum samples were collected at our institution from patients with BPH and patients with prostate carcinoma with similar blood prostate‐specific antigen levels. IgG was purified from individual prostate cancer sera, differentially labeled with fluorescent dyes, and competitively hybridized against purified IgG from a group of well‐characterized BPH control patients on our reverse capture microarray platform. For each experiment, we performed a two‐slide dye‐swap. Using this platform, we identified 28 unique antigen‐autoantibody reactivities that have the potential to discriminate prostate cancer from BPH. These autoantigens, with p‐values ≤0.01, can be placed into the following general categories: protein kinases, cell‐cycle regulators, cancer‐growth factors, apoptosis mediators, and transcription factors. In addition, only 1 of the 28 autoantigens remained differentially targeted by autoantibodies in post‐surgical prostate cancer patients after a minimum 1‐year follow‐up. Autoantibody profiling using this platform may be a useful tool for differentiating between malignant and benign diseases of the prostate.
The 2006 Human Liver Proteome Project (HLPP) Workshops
Authors: Mato José M. , He Fuchu , Beretta Laura
Published: April 2007

In 2006, scientists participating to the Human Liver Proteome Project (HLPP) launched by the Human Proteome Organisation (HUPO) convened on two occasions to present and discuss their progress. A workshop was held over two days in May in Bilbao, Spain, and a brief 3‐hour meeting was held in October in conjunction with the 5th HUPO World Congress in Long Beach, California. Highlights included progress on (i) the construction of the human normal liver proteome expression profile and of subcellular proteomes; (ii) establishment of a liver ORFeome bank and of a liver antibody bank; (iii) identifications of protein‐protein interaction maps in the liver; (iv) application of a robust strategy for quantitative proteomics; and (v) the characterization of fatty liver diseases using mouse models.
Phase transition associated with the variation of oxygen vacancy/ion distribution in the oxide‐ion conductor La2Mo2–xWxO9
Authors: Li D. , Wang X. P. , Fang Q. F. , Wang J. X. , Li C. , Zhuang Z.
Published: April 2007

The effects of tungsten doping in La2Mo2–x Wx O9 samples (x = 0, 0.1, 0.25, 0.5, 0.75, 1.0, 1.2, 1.4) were studied using dielectric relaxation measurements. Additional to the low‐temperature relaxation peak Pd associated with oxygen ion diffusion, a new dielectric loss peak Ph was observed around 740 K. With increasing tungsten concentration, the activation energy of peak Pd increases and saturates at a value of about 1.45 eV, and the height of peak Ph increases at first and then decreases after passing a maximum at 25% tungsten doping. With increasing measurement frequency, the height of peak Ph decreases monotonically but its position shifts very little. Peak Ph in pure and tungsten‐doped La2Mo2O9 is suggested to be associated with a phase transition from the static disordered state to the dynamic disordered state of oxygen ion/vacancy distribution. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Strain of single edge dislocations in bulk GaN
Authors: Gmeinwieser Nikolaus , Schwarz Ulrich T.
Published: April 2007

An edge dislocation causes a strain dipole field with compressive strain on one and tensile strain on the other side of the dislocation. We observe this strain dipole of single edge dislocations through the tiny spectral shift it causes to the narrow lines of the donor bound exciton at low temperatures. We demonstrate that the microscopic orientation of the Burgers vector given by the hexagonal lattice causes the orientation of these strain dipoles along six discrete directions at macroscopic scale. We also introduce a two‐dimensional convolution method using a complex convolution core for an accurate determination of the strain dipole orientation. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical properties of GaN nanopillar and nanostripe arrays with embedded InGaN/GaN multi quantum wells
Authors: Keller S. , Fichtenbaum N. A. , Schaake C. , Neufeld C. J. , David A. , Matioli E. , Wu Y. , DenBaars S. P. , Speck J. S. , Weisbuch C. , Mishra U. K.
Published: April 2007

GaN nanopillar and nanostripe arrays with embedded InGaN/GaN multi quantum wells (MQWs) were fabricated from planar wafers with different quantum well widths using holographic lithography and subsequent reactive ion etching. Although the etching process led to a reduction in the MQW related luminescence, the etch related damage was successfully healed through annealing in NH3/N2 mixtures under optimized conditions, and the annealed nanopatterned samples exhibited enhanced photoluminescence (PL) compared to the planar wafers. Angular‐resolved PL measurements revealed extraction of guided modes from the nanopillar and nanostripe arrays (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Elevated dopamine D2High receptors in α‐1b‐adrenoceptor knockout supersensitive mice
Authors: Tassin Jean‐Pol , Torrens Yvette , Salomon Lucas , Lanteri Christophe , Seeman Philip
Published: April 2007

Although amphetamine induces hyperactivity by releasing dopamine (DA), mice that lack α1b‐adrenoceptors do not release DA in response to amphetamine and do not, therefore, exhibit locomotor supersensitivity to amphetamine. However, such mice reveal hyperlocomotion to p‐chloroamphetamine (PCA). Because these α1b‐adrenoceptor knockout mice have no alterations in the striatal densities of DA D1 or D2 receptors, the basis for any possible dopaminergic contribution to the PCA‐induced hyperlocomotion to PCA is unclear. Therefore, because supersensitive animals are generally known to have a higher proportion of DA D2 receptors in the high‐affinity state for DA D2High, we investigated whether there was any change in the α1b‐adrenoceptor knockout striata in the proportion of DA D2High receptors to determine whether there could be a DA‐based contribution to the PCA‐induced hyperlocomotion. We found that the proportion of D2High in the wild type striata was 23 ± 3.3%, whereas that in the α1b‐adrenoceptor knockout striata was 52 ± 2.9%, an increase of 2.3‐fold. This elevation agrees with other types of DA‐supersensitive animal striata and could assist in eliciting a supersensitive response in these α1b‐adrenoceptor knockout mice. Synapse 61:569–572, 2007. © 2007 Wiley‐Liss, Inc.
Philosophy’s predicament and Hegel’s ghost: Reflections on the view that there is “no philosophy in China”
Authors: Yunyi ZHANG
Published: April 2007

When Western science was introduced to modern China, more translated words were used to express fundamental concepts and terms than borrowed words. The process of academic translation, commensuration, and communication between Western and Chinese philosophy is a process of comparative philosophical research. Nowadays, however, it seems that Chinese philosophy is evaluated by a Western Hegelian criterion. This leads to the debate over whether or not China has philosophy. But it is meaningless to argue about whether or not China has the name of philosophy. The key issue is whether or not China has the actuality of philosophy. Looking at the history of Western philosophy, it seems that the Hegelian definition of philosophy was the only one that existed in Europe. However, during the last 200 years after Hegel that the two main philosophical trends of positivism (scientism) and irrationalism developed from anti-Hegelianism or “Spurning Metaphysics.” As metaphysics is being reconstructed, the ghost of Hegel has reappeared. It is clear that in the future, philosophy will evolve from the development of human metaphysics or cultural philosophy. It is a process of the “negation of negation”: from traditional metaphysics to the spurning of metaphysics, and then to human metaphysics.
Just war and justice of war: Refl ections on ethics of war
Authors: Gaoshan ZUO
Published: April 2007

War can be defined as organized political violence among two or more nations. In accordance with the purpose, processes and results of war, the ethics of war generally comprises three aspects: right ethics, action ethics and duty ethics. The most important issue in ethics of war is “justice”. “Justice” and “injustice” as a conceptual pair do not prescribe the objective character of war but rather convey a subjective attitude and ethical position that have the potential to compel a populace to either support or oppose a war.
Synthesis and Physical Properties of Tallow‐Oleic Estolide 2‐Ethylhexyl Esters
Authors: Cermak Steven C. , Skender Alex L. , Deppe Amy B. , Isbell Terry A.
Published: April 2007

Tallow‐oleic estolide 2‐ethylhexyl (2‐EH) esters were synthesized in a perchloric acid catalyzed one‐pot process from industrial 90% oleic and tallow fatty acids at various ratios, while varying the ratio of tallow and oleic fatty acids, with the esterification process incorporated into an in situ second step to provide a functional fluid. Their viscosities ranged 57–80 cSt at 40 °C and 10.8–14.0 cSt at 100 °C with viscosity index (VI) 169–185. The 100% tallow estolide 2‐EH ester had modest low‐temperature properties (pour point = −15 °C and cloud point = −14 °C), while the 50:50 mixture of oleic and tallow fatty acids produced an estolide that had better low‐temperature properties (pour point = −21 °C and cloud point = −21 °C) without a large negative effect on the oxidative stability. The oxidative stability increased as the amount of saturation increased (rotating pressurized vessel oxidation test (RPVOT) × 165–274 min). The tallow‐oleic estolide 2‐EH esters have shown remarkably low evaporative losses of only 1% loss compared to a 15–17% loss for commercial materials of similar viscosity grade. Along with expected good biodegradability, these tallow‐oleic estolide 2‐EH esters had acceptable properties that should provide a specialty niche.
Genetik des Prostatakarzinoms
Authors: Maier C. , Vogel W.
Published: April 2007

Das Prostatakarzinom ist der häufigste maligne Tumor des Mannes, und es weist ätiologisch den größten genetischen Einfluss auf. Dennoch konnten bislang keine Gene identifiziert werden, die einen größeren Teil familiärer Fälle erklären und entsprechende Diagnostik ermöglichen. Keimbahnmutationen in 3 aus Kopplungsanalysen hervorgegangenen Genen (ELAC2, RNASEL, MSR1) sind zu selten und in ihrer Penetranz fraglich. Assoziationen zu diversen Genen sind meist schwach und nur für BRCA2 bzw. familiären Brustkrebs klinisch von Bedeutung. Infolge der extremen Heterogenität muss sich die genetische Beratung auf Risikoschätzungen aus dem Stammbaum stützen, wobei bereits ein betroffener Verwandter 1. Grades zu einem relevanten Risiko führt.
Erbliche Disposition zu Tumoren des Auges
Authors: Lohmann D.
Published: April 2007

Bei verschiedenen Tumordispositionserkrankungen mit pleiotropem Manifestationsspektrum ist das Auge mit involviert. Unter den monogen erblichen Tumorerkrankungen ist aus klinischer Sicht das erbliche Retinoblastom am wichtigsten. Das zur Erklärung seiner Entstehung entwickelte 2-Schritt-Mutationsmodell war auch für die Aufklärung anderer dominanter Tumordispositionen wegweisend. Bei den meisten anderen erblichen Krebserkrankungen sind die Manifestationen im Bereich des Auges für den Krankheitsverlauf nicht relevant, können aber zur Diagnose führen. Dies gilt insbesondere für das retinale kapillare Hämangiom bei Patienten mit einer Von-Hippel-Lindau-Erkrankung. Für die Entstehung des Aderhautmelanoms, des häufigsten bösartigen Augentumors, gibt es keinen Hinweis auf eine monogene Disposition. Allerdings lassen epidemiologische Daten vermuten, dass für seine Entstehung genetische Faktoren eine Rolle spielen. Die Prognose bei diesem Tumor ist eng mit einem somatischen genetischen Marker, der Monosomie 3, verbunden.
Dysynchiria is not a common feature of neuropathic pain
Authors: Krämer Heidrun H. , Seddigh Susann , Moseley G. Lorimer , Birklein Frank
Published: April 2007

Patients with chronic neuropathic pain (non‐CRPS) and brush‐evoked allodynia watched a reflected image of their corresponding but opposite skin region being brushed in a mirror. Unlike complex regional pain syndrome Type 1, this process did not evoke any sensation at the affected area (‘dysynchiria’). We conclude that central nociceptive sensitisation alone is not sufficient to cause dysynchiria in neuropathic pain. The results imply a difference in cortical pain processing between complex regional pain syndrome and other chronic neuropathic pain.
Pushing, pulling and trapping – Modes of motor protein supported protein translocation
Authors: Tomkiewicz Danuta , Nouwen Nico , Driessen Arnold J.M.
Published: April 2007

Protein translocation across the cellular membranes is an ubiquitous and crucial activity of cells. This process is mediated by translocases that consist of a protein conducting channel and an associated motor protein. Motor proteins interact with protein substrates and utilize the free energy of ATP binding and hydrolysis for protein unfolding, translocation and unbinding. Since motor proteins are found either at the cis‐ or trans‐side of the membrane, different mechanisms for translocation have been proposed. In the Power stroke model, cis‐acting motors are thought to push, while trans‐motors pull on the substrate protein during translocation. In the Brownian ratchet model, translocation occurs by diffusion of the unfolded polypeptide through the translocation pore while directionality is achieved by trapping and refolding. Recent insights in the structure and function of the molecular motors suggest that different mechanisms can be employed simultaneously.
A structural perspective on ClC channel and transporter function
Authors: Dutzler Raimund
Published: April 2007

The ClC chloride channels and transporters constitute a large family of membrane proteins that is involved in a variety of physiological processes. All members share a conserved molecular architecture that consists of a complex transmembrane transport domain followed by a cytoplasmic domain. Despite the strong conservation, the family shows an unusually broad variety of functional behaviors as some members work as gated chloride channels and others as secondary active chloride transporters. The conservation in the structure and the functional resemblance of gating and coupled transport suggests a strong mechanistic relationship between these seemingly contradictory transport modes. The cytoplasmic domains constitute putative regulatory components that are ubiquitous in eukaryotic ClC family members and that in certain cases interact with nucleotides thus linking ion transport to nucleotide sensing by yet unknown mechanisms.
Paleoenvironmental analysis of a middle Wisconsinan biota site, southwestern Virginia, U.S.A.
Authors: Whittecar G. Richard , Wynn Thomas C. , Bartlett Charles S.
Published: April 2007

The Ratcliff Site in southwestern Virginia lies in a small second-order stream valley filled with approximately 3.5 m of organic-rich deposits that contain bones of mammoth, mastodon, deer (or antelope), logs, and plant macrofossils. Radiocarbon analyses indicate the age of the organic-rich sediment ranges from > 44,000 to 29,100 14C yr BP, a time period with no fossil remains reported in this region of the Appalachians. Analyses of field observations, textural data, organic carbon content, and plant macrofossils indicate that the organic-rich sediments contain interbedded standing-water and debris-flow deposits. Up to 6 m of oxidized debris-flow sediments bury the organic-rich sediments. The presence ofRubus parviflorus(Thimble Berry) throughout the deposit indicates the site had a boreal environment from > 44,000 to 29,10014C yr BP. Plant macrofossil evidence indicates the uplands had stands of spruce/jack-pine forests while the valley contained ponds and associated wetlands. Three debris flows occurred at the site between approximately 38,000 and 29,000 14C yr BP, suggesting a recurrence interval for major storms of approximately 3000 yr, even though the apparent stability of the boreal environment implies a climate not conducive to catastrophic rainstorms. This conflicting combination of features suggests that during the middle Wisconsinan this area experienced generally cool climates, dominated by polar air masses, but was punctuated by relatively brief warm periods marked by incursions of tropical air masses.
Nut consumption in Spain and other countries
Authors: Aranceta Javier , Rodrigo Carmen Pérez , Naska Ada , Vadillo Virginia Ruiz , Trichopoulou Antonia
Published: April 2007

In countries of the Mediterranean region, nuts have been consumed in moderate quantities since ancient times. Epidemiological studies show lower risk of cardiovascular diseases in populations with frequent nut consumption, independent from other dietary components. This article assesses nut consumption in Spain and other countries using different sources of data collected at the country, household or individual levels. The per capita consumption of nuts in Spain in 2001 was 7·9 g/person/d. The varieties most widely consumed are walnuts, almonds, hazelnuts and peanuts. Results of the eVe study estimate an average nut consumption in the Spanish population aged 25–60 years of 3·3 g/person/d. No significant statistical differences were observed between men and women. Consumption is higher in men aged between 35 and 44 years (4·5 g/d) and in women aged between 45 and 54 years (3·5 g/d). In the population of 2–24 years, according to the enKid study, nut consumption is estimated at 4·9±18·5 g/person per d. The age group with the highest consumption is teenagers between 14 and 17 years. The northeastern, northern and eastern regions of Spain show the highest consumption. According to FAO balance sheets, in 2001, Lebanon (16·5 kg/person peryear) and Greece (11·9 kg/person per year) were the countries in the Mediterranean region with the highest consumption of nuts, followed by Spain (7·3 kg/person per year), Israel and Italy.
Three-dimensional transition in the wake of a transversely oscillating cylinder
Authors: LEONTINI JUSTIN S. , THOMPSON M. C. , HOURIGAN K.
Published: April 2007

A Floquet stability analysis of the transition to three-dimensionality in the wake of a cylinder forced to oscillate transversely to the free stream has been undertaken. The effect of varying the oscillation amplitude is determined for a frequency of oscillation close to the natural shedding frequency. The three-dimensional modes that arise are identified, and the effect of the oscillation amplitude on their structure and growth rate quantified.

It is shown that when the two-dimensional wake is in the 2S configuration (which is similar to the Kármán vortex street), the three-dimensional modes that arise are similar in nature and symmetry structure to the modes in the wake of a fixed cylinder. These modes are known as modes A, B and QP and occur in this order with increasing Re. However, increasing the amplitude of oscillation causes the critical Reynolds number for mode A to increase significantly, to the point where mode B becomes critical before mode A. The critical wavelength for mode A is also affected by the oscillation, becoming smaller with increasing amplitude. Elliptic instability theory is shown also to predict this trend, providing further support that mode A primarily arises as a result of an elliptic instability.

At higher oscillation amplitudes, the spatio-temporal symmetry of the two-dimensional wake changes and it takes on the P + S configuration, with a pair of vortices on one side of the wake and a single vortex on the other side, for each oscillation cycle. With the onset of this configuration, modes A, B and QP cease to exist. It is shown that two new three-dimensional modes arise from this base flow, which we call modes SL and SS. Both of these modes are subharmonic, repeating over two base-flow periods. Also, either mode can be the first to become critical, depending on the amplitude of oscillation of the cylinder.

The emergence of these two new modes, as well as the reversal of the order of inception of the three-dimensional modes A and B, leads to the observation that for an oscillating cylinder wake there are four different modes that can lead the transition to three-dimensionality, depending on the amplitude of oscillation. Therefore this type of flow provides a good example for studying the effect of mode-order inception on the path taken to turbulence in bluff-body wakes.

For the range of amplitudes studied, the maximum Re value for which the flow remains two-dimensional is 280.
On ice-induced instability in free-surface flows
Authors: SHAPIRO EVGENIY , TIMOSHIN SERGEI
Published: April 2007

The problem of stability of a water-coated ice layer is investigated for a free-surface flow of a thin water film down an inclined plane. An asymptotic (double-deck) theory is developed for a flow with large Reynolds and Froude numbers which is then used to investigate linear two-dimensional, three-dimensional and nonlinear two-dimensional stability characteristics. A new mode of upstream-propagating instability arising from the interaction of the ice surface with the flow is discovered and its properties are investigated. In the linear limit, closed-form expressions for the dispersion relation and neutral curves are obtained for the case ofPr= 1. For the general case, the linear stability problem is solved numerically and the applicability of the solution withPr= 1 is analysed. Nonlinear double-deck equations are solved with a novel global-marching-type scheme and the effects of nonlinearity are investigated. An explanation of the physical mechanism leading to the upstream propagation of instability waves is provided.
Acoustic near field of a transonic instability wave packet
Authors: LE DIZÈS STÉPHANE , MILLET CHRISTOPHE
Published: April 2007

We consider the problem of acoustic radiation generated by a spatial instability wave on a weakly developing shear flow. Assuming a local WKBJ approximation for the instability wave near its maximum, we compute the acoustic pressure field by using a Fourier transform along the streamwise direction. When the instability wave is close to transonic near its maximum amplitude, approximations for this pressure field are obtained by a steepest descent method. A branch cut and several saddle points are shown possibly to contribute to the approximation. A detailed analysis of these contributions is provided. The modifications of the acoustic field when we pass from subsonic to supersonic are examined. In particular, the superdirective character of the acoustic field of subsonic instability waves and the directivity pattern of supersonic waves are shown to be both compatible with our mathematical description and associated with a single saddle-point contribution.

The acoustic near field is also shown to possess a caustic around which a specific approximation is derived. In a large region of the physical space, the near field is composed of two saddle-point contributions. Close to the shear flow, one of these contributions degenerates into a branch-point contribution which always becomes dominant over the instability wave downstream of a location that is computed. An interesting phenomenon is observed in certain regions downstream of the maximum: the transverse behaviour of the instability wave has to be exponentially growing far from the shear layer to match the acoustic field. We demonstrate that this phenomenon neither requires a branch-point contribution nor a supersonic instability wave.
Two-point similarity in the round jet
Authors: EWING D. , FROHNAPFEL B. , GEORGE W. K. , PEDERSEN J. M. , WESTERWEEL J.
Published: April 2007

The governing equations for the two-point velocity correlations in the far field of the axisymmetric jet are examined and it is shown that these equations can have equilibrium similarity solutions for jets with finite Reynolds number that retain a dependence on the growth rate of the jet. The two-point velocity correlation can be written as the product of a scale that depends on the downstream position of the two points and a function that only depends on the similarity variables. Physically, this result implies that the turbulent processes producing and dissipating energy at the different scales of motion, as well as transferring energy between the different scales of motion, are in equilibrium as the flow evolves downstream. A particularly interesting prediction from the analysis is that the two-point similarity solutions depend only on the separation distance between the points in the streamwise similarity coordinate (i.e. υ = ξ′ − ξ), that is, the logarithm of the streamwise coordinate itself (i.e. ξ = lnx1, wherex1is measured from a virtual origin). Thus, the measures of the turbulence are homogeneous in the streamwise similarity coordinate.

The predictions from the similarity analysis for the streamwise two-point velocity correlation were compared with combined hot-wire and LDA measurements on the centreline of a round jet at a Reynolds number of 33000, and with two-point velocity correlations computed from PIV measurements in a round jet at a Reynolds number of 2000 performed by Fukushimaet al. In both cases, the measured two-point velocity correlations in the streamwise direction collapsed when they were scaled in the manner predicted by the similarity analysis. The results provide further evidence that the equilibrium similarity hypothesis does describe the development of the flow in fully developed turbulent round jets and that the two-point correlations are statistically homogeneous in the streamwise similarity coordinate.
Relaxation dynamics of water-immersed granular avalanches
Authors: DOPPLER DELPHINE , GONDRET PHILIPPE , LOISELEUX THOMAS , MEYER SAM , RABAUD MARC
Published: April 2007

We study water-immersed granular avalanches in a long rectangular cell of small thickness. By video means, both the angle of the granular pile and the velocity profiles of the grains across the depth are recorded as a function of time. These measurements give access to the instantaneous granular flux. By inclining the pile at initial angles larger than the maximum angle of stability, avalanches are triggered and last for a long time, up to several hours for small grains, during which both the slope angle and the granular flux relax slowly. We show that the relaxation is quasi-steady so that there is no inertia: the relaxation at a given time is controlled only by the slope angle at that time. This allows us to adapt a frictional model developed recently for dry or water-immersed grains flowing in stationary conditions. This model succeeds well in reproducing our unsteady avalanche flows, namely the flowing layer thickness, the granular flux and the temporal relaxation of the slope. When a water counter-flow is applied along the pile, the granular avalanches are slowed down and behave as if granular friction were increased by an amount proportional to the water flow. All these findings are also reproduced well with the same friction model by taking into account the additional fluid force.
Segregation of a liquid mixture by a radially oscillating bubble
Authors: LOUISNARD OLIVIER , GOMEZ FRANCISCO J. , GROSSIER ROMAIN
Published: April 2007

A theoretical formulation is proposed for forced mass transport by pressure gradients in a liquid binary mixture around a spherical bubble undergoing volume oscillations in a sound field. Assuming the impermeability of the bubble wall to both species, diffusion driven by pressure gradients and classical Fick-diffusion must cancel at the bubble wall, so that an oscillatory concentration gradient arises in the vicinity of the bubble. The Péclet number pe is generally high in typical situations and Fick diffusion cannot restore equilibrium immediately, so that an asymptotic average concentration profile may progressively build up in the liquid over large times. Such a behaviour is reminiscent of the so-called rectified diffusion problem, leading to slow growth of a gas bubble oscillating in a sound field. A rigorous method formerly proposed by Fyrillas & Szeri (J. Fluid Mech. vol. 277, 1994, p. 381) to solve the latter problem is used to solve the present one. It is based on splitting the problem into a smooth part and an oscillatory part. The smooth part is solved by a multiple scales method and yields the slowly varying average concentration field everywhere in the liquid. The oscillatory part is obtained by matched asymptotic expansions in terms of the small parameter pe−1/2: the inner solution is required to satisfy the oscillatory balance between pressure diffusion and Fick diffusion at the bubble wall, while the outer solution is required to be zero. Matching both solutions yields a unique splitting of the problem. The final analytical solution, truncated to leading order, compares successfully to direct numerical simulation of the full convection–diffusion equation. The analytical expressions for both smooth and oscillatory parts are calculated for various sets of bubble parameters: driving pressure, frequency and ambient radius. The smooth problem always yields an average depletion of the heaviest species at the bubble wall, only noticeable for large molecules or nano-particles. For driving pressures sufficiently high to yield inertial oscillations of the bubble, the oscillatory problem predicts a periodic peak excess concentration of the heaviest species at the bubble wall at each collapse, lingering on several tens of the time of the characteristic duration of the bubble rebound. The two effects may compete for large molecules and practical implications of this segregation phenomenon are proposed for various processes involving acoustic cavitation.
Interpretation of the mechanism associated with turbulent drag reduction in terms of anisotropy invariants
Authors: FROHNAPFEL B. , LAMMERS P. , JOVANOVIĆ J. , DURST F.
Published: April 2007

A central goal of flow control is to minimize the energy consumption in turbulent flows and nowadays the best results in terms of drag reduction are obtained with the addition of long-chain polymers. This has been found to be associated with increased anisotropy of turbulence in the near-wall region. Other drag reduction mechanisms are analysed in this respect and it is shown that close to the wall highly anisotropic states of turbulence are commonly found. These findings are supported by results of direct numerical simulations which display high drag reduction effects of over 30% when only a few points inside the viscous sublayer are forced towards high anisotropy.
Akutes Abdomen aus gastroenterologischer Sicht
Authors: Dietrich  , Müller  , Ignee
Published: April 2007

Das «akute Abdomen» bezeichnet einen akut bedrohlichen Zustand mit starken (progredienten) Bauchschmerzen, der wegen der Tendenz zur raschen Verschlimmerung der unverzüglichen Abklärung bedarf; eine prompte chirurgische Therapie ist häufig notwendig. Die zur Diagnostik verfügbare Zeit richtet sich nach der Symptomatik und dem Schweregrad des Krankheitsbildes. In dem vorliegenden Manuskript wird die Bedeutung der Sonographie zur Diagnostik häufiger gastroenterologischer Ursachen des akuten Abdomens dargestellt.
Link budget and radio coverage design for various multipath urban communication links
Authors: Yarkoni N. , Blaunstein N. , Katz D.
Published: April 2007

This study deals with theoretical and experimental prediction of types of fading, slow and fast, and the total path loss that occur in the urban land radio channel for various elevations of base station and moving subscriber antenna with respect to building rooftops. A new distribution function, which covers the well‐known classical Rice and Rayleigh statistical distributions, is derived on the basis of experimental data obtained for various situations in the urban scene and of the stochastic multiparametric model that describes multiray effects that occur in the urban communication link. The total path loss is derived for various urban propagation scenarios, taking into account the corresponding fading caused by shadowing and multipath effects. Radio maps of two experimental urban sites are designed. On the basis of the topographic features of one of these sites, the optimal number of antennas and their positions are predicted to achieve maximum radio coverage of area of service. The obtained results allow us to use the proposed unified stochastic model for slow and fast fading effects estimation in link budget performance and radio map design only on the basis of the topographic map of the corresponding terrain under investigations, the buildings' overlay profile, and the parameters of the base station antennas.
Ozonesonde observations in the Arctic during 1989–2003: Ozone variability and trends in the lower stratosphere and free troposphere
Authors: Kivi R. , Kyrö E. , Turunen T. , Harris N. R. P. , von der Gathen P. , Rex M. , Andersen S. B. , Wohltmann I.
Published: April 2007

We have studied the interannual and longer‐term variations in ozone profiles over the Arctic from 1989 to 2003 using ozonesonde observations from seven northern high‐latitude stations. The ozonesonde data have been carefully examined and made as internally consistent as possible. The homogenized measurements are analyzed with a statistical model. In both the stratosphere and troposphere the largest long‐term changes have occurred in the late winter/spring period (January–April), the period of greatest interannual variability. In the stratosphere, layer ozone amounts correlate highly with proxies for the stratospheric circulation (100 hPa eddy heat flux averaged over 45–70°N), polar ozone depletion (the calculated volume of polar stratospheric clouds combined with the effective equivalent stratospheric chlorine) and tropopause height. At altitudes between 50 and 70 hPa, we estimate that chemical polar ozone depletion accounted for up to 50% of the March ozone variability. Negative trends in the lower stratosphere prior to 1997 can be attributed to the combined effect of dynamical changes, the impact of aerosols from the Mt. Pinatubo eruption and winters of relatively large chemical ozone depletion. Since 1996–1997 the observed increase in lower stratospheric ozone can be attributed primarily to dynamical changes. In the free troposphere, a statistically significant increase of 11.3 ± 1.8% over 15 years is observed which also maximizes in the January to April period (16.0 ± 3.1% over 15 years). The model suggests that this can be attributed to the effects of changes in the Arctic Oscillation.
Polar mesospheric cloud mass and the ice budget: 3. Application of a coupled ice‐chemistry‐dynamics model and comparison with observations
Authors: Siskind David E. , Hervig Mark , Gumbel Jörg , Stevens Michael H.
Published: April 2007

We have combined a two‐dimensional chemical/dynamics model with a monodisperse parameterization of polar mesospheric clouds (PMCs) to study the interaction of PMCs with the climate of the summer mesopause region. First, we show that PMC absorption of terrestrial and solar IR radiation lead to atmospheric heating rates which can exceed 10 K/day. This heat is dissipated by increased upwelling above the cloud layer and by a 2–6 K temperature increase. We then calculate the global PMC ice mass and evaluate its sensitivity to IR heating, assumed particle size and level of solar activity. Inclusion of the temperature increase in the model can reduce the calculated ice mass by up to a factor of two. The calculated solar cycle range in the ice mass is also about a factor of two. The calculated latitude distribution and solar cycle range of PMC ice mass are in good agreement with recent analyses of PMC satellite data. Finally, we test the hypothesis that PMC formation leads to ozone changes by comparing our model with ozone data from the Halogen Occultation Experiment (HALOE). The data show a 20–30% ozone enhancement above PMCs. In the model, dehydration above the cloud layer leads to an ozone increase due to lowered HOx. However, this competes with the temperature increase from IR absorption that can damp out this ozone increase. Surprisingly, for realistic estimates of the terrestrial IR flux, the model ozone response is reduced to well below that observed by HALOE.
Polar mesospheric cloud mass and the ice budget: 1. Quantitative interpretation of mid‐UV cloud brightness observations
Authors: Englert Christoph R. , Stevens Michael H.
Published: April 2007

We investigate the retrieval of column ice mass from mid‐UV solar scattering polar mesospheric cloud (PMC) observations to help constrain estimates of the ice budget of the polar summer mesosphere. First, we show that the backscattered brightness from PMC particles is roughly proportional to the mass of the ice particles. Second, we quantify the sensitivity of the retrieved PMC column ice mass to the particle size distribution for a viewing geometry typical for a subset of Solar Backscattered UltraViolet (SBUV) satellite data taken at 70 ± 2.5°N. Considering a wide range of Gaussian size distributions using spherical particles with peak radii between 15 nm and 100 nm and widths between 10 nm and 20 nm, we find that we can constrain the inferred ice column mass to ±43% for 95% of the distributions in this range. For this scenario we also show that spheroids with axis ratios of 0.5, 2.0 and 5.0 generally decrease the sensitivity of the inferred ice column mass to the size distribution. Third, we quantify the sensitivity of the retrieved PMC column ice mass for a viewing geometry typical for a subset of Student Nitric Oxide Explorer (SNOE) satellite data. Using the same wide range of size distributions, we show that the inferred ice column mass can be constrained to ±33% for 95% of the distributions in this range. The results of this paper are used by two companion papers to investigate the polar mesospheric ice budget.
Intertidal sand body migration along a megatidal coast, Kachemak Bay, Alaska
Authors: Adams Peter N. , Ruggiero Peter , Schoch G. Carl , Gelfenbaum Guy
Published: April 2007

Using a digital video‐based Argus Beach Monitoring System (ABMS) on the north shore of Kachemak Bay in south central Alaska, we document the timing and magnitude of alongshore migration of intertidal sand bed forms over a cobble substrate during a 22‐month observation period. Two separate sediment packages (sand bodies) of 1–2 m amplitude and ∼200 m wavelength, consisting of well‐sorted sand, were observed to travel along shore at annually averaged rates of 278 m/yr (0.76 m/d) and 250 m/yr (0.68 m/d), respectively. Strong seasonality in migration rates was shown by the contrast of rapid winter and slow summer transport. Though set in a megatidal environment, data indicate that sand body migration is driven by eastward propagating wind waves as opposed to net westward directed tidal currents. Greatest weekly averaged rates of movement, exceeding 6 m/d, coincided with wave heights exceeding 2 m suggesting a correlation of wave height and sand body migration. Because Kachemak Bay is partially enclosed, waves responsible for sediment entrainment and transport are locally generated by winds that blow across lower Cook Inlet from the southwest, the direction of greatest fetch. Our estimates of sand body migration translate to a littoral transport rate between 4,400–6,300 m3/yr. Assuming an enclosed littoral cell, minimal riverine sediment contributions, and a sea cliff sedimentary fraction of 0.05, we estimate long‐term local sea cliff retreat rates of 9–14 cm/yr. Applying a numerical model of wave energy dissipation to the temporally variable beach morphology suggests that sand bodies are responsible for enhancing wave energy dissipation by ∼13% offering protection from sea cliff retreat.
Production and characterization of anti‐(mucin MUC1) single‐domain antibody in tobacco (Nicotiana tabacum cultivar Xanthi)
Authors: Ismaili Ahmad , Jalali‐Javaran Mokhtar , Rasaee Mohammad J. , Rahbarizadeh Fatemeh , Forouzandeh‐Moghadam Mehdi , Memari Hamid Rajabi
Published: April 2007

Members of the Camelidae (camels, dromedaries, llamas, alpacas, guanacos and vicunas) are known to produce Igs (immunoglobulins) devoid of light chains and CH1s (constant heavy‐chain domains). The antigen‐specific binding fragments of these heavy‐chain antibodies therefore comprise one single domain (the so‐called ‘VHH’) and are of great importance in biotechnological applications. To evaluate the expression and biological activity of sdAbs (single‐domain antibodies) in plants, which, on account of their small size and antigen‐recognition properties, would have a major impact on antibody‐engineering strategies, we constructed a pBI121‐VHH gene encoding the recombinant sdAb fragments with specificity for a cancer‐associated mucin, MUC1. Analysis of transgenic tobacco (Nicotiana tabacum cultivar Xanthi) plants by PCR and Western blotting demonstrated the expression of sdAb, while ELISA results with various MUC1 antigens and immunocytochemistry with cancerous cell lines confirmed that the activity of these molecules compared favourably with that of the parent recombinant antibodies. Protein purification was achieved by using sequential (NH4)2SO4 precipitation, gel filtration and immunoaffinity chromatography. Analysis of the purified VHH by ELISA indicated that the purified antibody fragments were able to react successfully with a MUC1‐related peptide. These results reaffirm that the tobacco plant is a suitable host for the production of correctly folded VHH antibody fragments with diagnostic and therapeutic applications.
A cell‐based assay system for high‐throughput screening of anti‐wrinkle agents in human dermal fibroblast transfectant cells
Authors: Huh Sungran , Lee Jongsung , Jung Eunsun , Ham Yeonggeun , Kim Sang Suk , Hyun Chang Gu , Kim Yeong Shik , Park Deokhoon
Published: April 2007

A cell‐based assay system for monitoring COL1A2 [α2(I) collagen gene] promoter activity was developed to determine the influence of activated COL1A2 promoter in human dermal fibroblast cells. A pLuc‐COL1A2 promoter plasmid that expresses the luciferase reporter gene in response to COL1A2 promoter activity was constructed. The pLuc‐COL1A2 promoter plasmid and pCI‐neo plasmid containing the NPT (neomycin phosphotransferase) gene for Geneticin resistance in host cells were co‐transfected into human dermal fibroblast cells. COL1A2 promoter activities were measured by luciferase reporter gene assay using a luminescence detection method. Fibroblast cell transfectants treated with TNFα (tumour necrosis factor α), known to be an inhibitor of COL1A2 promoter expression, showed a reduction of COL1A2 promoter activity in a concentration‐dependent manner, whereas TGF‐β (transforming growth factor‐β), known to be a stimulator of COL1A2 promoter expression, increased COL1A2 activity in a concentration‐dependent manner. This assay system could be used to quantitatively measure COL1A2 promoter activity in human dermal fibroblast cells and allow the screening of anti‐wrinkle agents from various synthetic chemicals and natural products.
Production of bubaline somatotropin by auto‐induction in Escherichia coli
Authors: Sadaf Saima , Khan Muhammad Altaf , Akhtar Muhammad Waheed
Published: April 2007

Production of His–BbST [hexahistidine‐tagged BbST (bubaline somatotropin)] by auto‐induction in high‐density shake‐flask cultures coupled with a single‐step, on‐column purification and refolding strategy is described here. To optimize expression of BbST, different media and expression conditions were tested. The highest expression levels of BbST, exceeding 30% of the total Escherichia coli cellular proteins, were achieved when YNG and M9NG media were used. Using these auto‐inducing media, the final concentration of BbST increased up to 455 mg/l and was severalfold higher than that obtained by isopropyl β‐d‐thiogalactoside induction. Most of the target protein, however, was in the form of inclusion bodies, which were solubilized in 8 M urea solution (pH 8.5). Using immobilized‐metal‐ion‐affinity chromatography, His–BbST could be purified from solubilized sample to >97% homogeneity in a single step in a biologically active state as judged by its efficient growth‐promoting activity in Nb2 rat lymphoma cell proliferation assays. The expression and purification scheme, presented here, has a potential of scaling up to obtain pure and biologically active His–BbST relatively inexpensively for further studies and applications.
Recombinant production of antimicrobial peptides in heterologous microbial systems
Authors: Ingham Aaron B. , Moore Robert J.
Published: April 2007

The emergence and rapid horizontal spread of antibiotic‐resistant traits in bacteria of human and veterinary clinical significance has been a driving force in the search for new classes of antibiotics. Recent studies have shown that AMPs (antimicrobial peptides) potentially have a role in addressing this problem. These AMPs are produced naturally by a diverse array of organisms, including bacteria, plants, insects, fish and mammals. Given this diversity, researchers trying to perform comparative studies on AMPs are likely to encounter difficulties in obtaining workable quantities of peptide. Such studies are required for optimization of antimicrobial activity, product stability, mode of delivery and industrial‐scale production, and are vital if these peptides are ever to be brought to the market. Recombinant expression of AMPs is one hope for producing suitable amounts of diverse peptides. Here we review the literature regarding microbial heterologous expression systems for the production of recombinant AMPs.