bluuebunny/crossref_metadata_2025 huggingface dataset:
Perturbed angular correlation spectroscopy and its application to metal sites in proteins: possibilities and limitations
Authors: Bauer Rogert
Published: March 2009

The present review describes the methodology of perturbed angular correlation of gamma rays (PAC) applied to biological problems. A large part of the present review focuses on the application of PAC spectroscopy to the study of coordination geometry for the metal site in zinc enzymes. Applications to conformation and dynamics of biomolecules and the use of the method to identify the intracellular sites of either metals or labelled proteins are also discussed.
Calculation of unstirred layer thickness in membrane transport experiments: a survey
Authors: Pedley T. J.
Published: March 2009

It has long been recognized that measurements of the permeability characteristics of membranes (and of epithelia) may be strongly influenced by the presence of unstirred, or diffusion, layers adjacent to the membranes: see Dainty (1963) for the first systematic discussion of the subject in a biological context and Barry & Diamond (1983) for an important recent review. Consider a homogeneous, plane, uncharged membrane separating two solutions of the same solute at different bulk concentrations Cb+ and Cb- (Fig. 1), but at the same hydrostatic pressure and electrostatic potential (note that in this paper subscripts + and − refer to the two sides of the membrane, not to cation and anion parameters; electroneutrality is assumed throughout).
Reverse-correlation methods in auditory research
Authors: Eggermont J. J. , Johannesma P. I. M. , Aertsen A. M. H. J.
Published: March 2009

Single unit recordings have provided us with a basis for understanding the auditory system, especially about how it behaves under stimulation with simple sounds such as clicks and tones. The experimental as well as the theoretical approach to single unit studies has been dichotomous. One approach, the more familiar, gives a representation of nervous system activity in the form of peri-stimulus-time (PST) histograms, period histograms, iso-intensity rate curves and frequency tuning curves. This approach observes the neural output of units in the various nuclei in the auditory nervous system, and, faced with the random way in which the neurons respond to sound, proceeds by repeatedly presenting the same stimulus in order to obtain averaged results. These are the various histogram procedures (Gerstein & Kiang, 1960; Kiang et al. 1965).
Costs of accuracy determined by a maximal growth rate constraint
Authors: Ehrenberg Måns , Kurland C. G.
Published: March 2009

The present study is best understood as an extension and critique of two schools of thought. The first is that of Malloe and his students, among whom we number ourselves. It is to Maaloe that we are indebted for the idea that logarithmically growing bacteria assemble and use tibosomes in amounts that are optimally adjusted to yield the maximal growth rates supported by different media. Her, we begin our analysis by applying this optimization priciple to all the components of a logarithmically growing system. Our objective is to use the growth optimization constraint as a tool to explore the physiological limits on the accuracy of gene expression. This brings us to our second source of inspiration, which is Orgel's (1963) conception of a problem that Ninio (1982) has referred to as the ‘great error loop’.
Physical Models for the Analysis of Acoustical Systems in Biology
Authors: Fletcher N. H. , Thwaites Suszanne
Published: March 2009

(Quart. Rev. Biophys. 12, 1, February 1979, page 51) contained several drafting errors. It should be replaced by the corrected version below.
DNA supercoiling and transcription: topological coupling of promoters
Authors: Lilley David M. J. , Chen Dongrong , Bowater Richard P.
Published: March 2009

DNA supercoiling is a consequence of the double-stranded nature of DNA. When a linear DNA molecule is ligated into a covalently closed circle, the two strands become intertwined like the links of a chain, and will remain so unless one of the strands is broken. The number of times one strand is linked with the other is described by a fundamental property of DNA supercoiling, the linking number (Lk).
Magic angle spinning NMR spectroscopy of membrane proteins
Authors: Smith Steven O. , Aschheim Kathryn. , Groesbeek Michel
Published: March 2009

The passage of molecules and information across cell membranes is mediated largely by membrane-spanning proteins acting as channels, pumps, receptors and enzymes. These proteins perform many tasks: they control electrochemical gradients across the membrane, receive signals from the environment or from other cells, convert light energy into chemical signals, transport small molecules into and out of cells, and harness proton gradients to generate the energy consumed in metabolism. Indeed, of the estimated 50000–100000 genes in the human genome, fully 20–40 % are thought to encode integral membrane proteins. If one also includes membrane-associated proteins, which are attached to the membrane surface through fatty acyl chains or electrostatic interactions, this percentage is likely to be much higher.
Rapid control prototyping for robot soccer
Authors: Jang Junwon , Han Soohee , Kim Hanjun , Ahn Choon Ki , Kwon Wook Hyun
Published: March 2009

In this paper, we propose rapid-control prototyping (RCP) for a robot soccer using the SIMTool that has been developed in Seoul National University, Korea, for the control-aided control system design (CACSD). The proposed RCP enables us to carry out the rapid design and the verification of controls for two-wheeled mobile robots (TWMRs), players in the robot soccer, without writing C codes directly and requiring a special H/W. On the basis of the proposed RCP, a blockset for the robot soccer is developed for easy design of a variety of mathematical and logical algorithms. All blocks in the blockset are made up of basic blocks offered by the SIMTool. Applied algorithms for specific purposes can be easily and efficiently constructed with just a combination of the blocks in the blockset. As one of the algorithms implemented with the developed blockset, a novel navigation algorithm, called a reactive navigation algorithm using the direction and the avoidance vectors based scheme (RNDAVS), is proposed. It is shown through simulations and experiments that the RNDAVS designed with the proposed RCP can avoid a local minima and the goal non-reachable with obstacles nearby (GNRON) arising from the existing methods. Furthermore, in order to validate the proposed RCP in a real game, we employ an official simulation game for the robot soccer, the SimuroSot. Block diagrams are constructed for strategy, path calculation, and the interface to the SIMTool. We show that the algorithms implemented with the proposed RCP work well in the simulation game.
A comparison of Arctic and Antarctic climate change, present and future
Authors: Walsh John E.
Published: March 2009

Ongoing climate variations in the Arctic and Antarctic pose an apparent paradox. In contrast to the large warming and loss of sea ice in the Arctic in recent decades, Antarctic temperatures and sea ice show little change except for the Antarctic Peninsula. However, model simulations indicate that the Arctic changes have been shaped largely by low-frequency variations of the atmospheric circulation, superimposed on a greenhouse warming that is apparent in model simulations when ensemble averages smooth out the circulation-driven variability of the late 20th century. By contrast, the Antarctic changes of recent decades appear to be shaped by ozone depletion and an associated strengthening of the southern annular mode of the atmospheric circulation. While the signature of greenhouse-driven change is projected to emerge from the natural variability during the present century, the emergence of a statistically significant greenhouse signal may be slower than in other regions. Models suggest that feedbacks from retreating sea ice will make autumn and winter the seasons of the earliest emergence of the greenhouse signal in both Polar Regions. Priorities for enhanced robustness of the Antarctic climate simulations are the inclusion of ozone chemistry and the realistic simulation of water vapour over the Antarctic Ice Sheet.
PELVIC FLOOR ASSESSMENT
Authors: DIETZ HANS PETER
Published: March 2009

The topic of pelvic floor assessment is increasingly attracting attention from gynaecologists, colorectal surgeons, urologists and physiotherapists. This is not surprising, many women who have given birth naturally are affected by pelvic floor trauma, and so are their partners. Health professionals deal with the eventual consequences of such trauma, especially pelvic organ prolapse and faecal incontinence.
Regenerative Medizin in der Kardiologie
Authors: Chatterjee  , Ortak  , Akin  , Adolph  , Kleinfeldt  , Kische  , Nienaber  , Ince
Published: March 2009

Die regenerative Medizin hat die Wiederherstellung physiologischer Strukturen kritisch geschädigter Organe zum Ziel. Eine vielversprechende Quelle für therapeutische Ansätze sind Stammzellen. Stammzellen werden bereits seit Langem in der Onkologie eingesetzt und sind aufgrund ihres regenerativen Potenzials und optimalen Sicherheitsprofils für zelltherapeutische Ansätze geeignet. In der Kardiologie sind bisher eine Reihe verschiedene Stammzellen evaluiert worden, dabei gibt es zunehmende präklinische und klinische Daten hinsichtlich der Durchführbarkeit und der Sicherheit im Bereich des akuten Myokardinfarkts und der chronischen Herzinsuffizienz. Im Rahmen dieses Übersichtsartikels werden die regenerativen Konzepte und verschiedenen Zell-Entitäten im Einzelnen näher erläutert.
Erhöhte Transaminasen – wie weiter, wenn bereits alles gesucht wurde?
Authors: Lepper  , Dufour
Published: March 2009

Transaminasen sowie γ-GT und alkalische Phosphatase (AP) werden im Allgemeinen als klassische Leberenzyme bezeichnet, kommen aber in fast jedem Organ vor. Eine Erhöhung der Transaminasen ALAT (Alanin-Aminotransferase oder GPT, Glutamat-Pyruvat-Transaminase) und ASAT (Aspartat-Aminotransferase oder GOT, Glutamat-Oxalazetat-Transferase) zeigt eine Permeabilitätsstörung von Zellen an, die diese Enzyme enthalten. Während die ALAT weitgehend leberspezifisch ist, ist die ASAT z.B. auch in Skelett- und Herzmuskel vorhanden. Bei einer geringen Erhöhung dieser Enzyme ist zunächst eine Verlaufskontrolle angezeigt. Stammen die Transaminasen wahrscheinlich von einer Lebererkrankung und sind sie persistierend erhöht, so ist eine spezifische weitere Abklärung erforderlich. In diesem Manuskript diskutieren wir die häufig vergessenen Ursachen und beschreiben einen diagnostischen Algorithmus.
On the Crucial Role of Mental Ingroup Representation for Ingroup Bias and the Ingroup Prototypicality-Ingroup Bias Link
Authors: Machunsky Maya , Meiser Thorsten , Mummendey Amélie
Published: March 2009

Previous research suggested that relative ingroup prototypicality is a basis for ingroup bias. To test the boundary conditions of this phenomenon, we hypothesized that people particularly rely on relative ingroup prototypicality as a basis for ingroup bias if the prototypicality information is derived from a homogeneous and simple ingroup representation. We, therefore, predicted increased ingroup bias together with a stronger relation between prototypicality and ingroup bias if the ingroup is formed of consistent group members only. In two experiments, we used different subtyping manipulations and showed that the exclusion of inconsistent parts of the ingroup leads to a strong relation between relative ingroup prototypicality and ingroup bias, whereas this relation was nonsignificant without subtyping. Furthermore, ingroup bias was more pronounced after subtyping. These results confirm that the homogeneity and the simplicity of the ingroup representation is an important moderator for the relation between ingroup projection and intergroup judgments.
Strengthening the Case for Stimulus-Specificity in Artificial Grammar Learning
Authors: Johansson Tobias
Published: March 2009

Different theories have been proposed regarding the nature of the mental representations formed as a result of implicit learning of sequential regularities. Some theories postulate abstract surface-independent representations, while other theories postulate stimulus-specific representations. This article reports three experiments investigating the development of abstract representations in artificial grammar learning (AGL), using a methodological approach developed by Conway and Christiansen (2006). In all the experiments, the number of blocks during the exposure phase was manipulated (6 blocks vs. 18 blocks of exposure to sequences). Experiments 1 and 2 investigated both visual and auditory learning where sequences were presented element-by-element. Experiment 3 investigated visual learning using a sequence-by-sequence presentation technique more commonly used in visual AGL studies. Extending previous research (Conway & Christiansen, 2006) and in support of stimulus-specific accounts, the results of the experiments showed that extended observational learning results in increased stimulus-specific knowledge rather than abstraction towards surface-independent representations.
Mathematical models of vegetation pattern formation in ecohydrology
Authors: Borgogno F. , D'Odorico P. , Laio F. , Ridolfi L.
Published: March 2009

Highly organized vegetation patterns can be found in a number of landscapes around the world. In recent years, several authors have investigated the processes underlying vegetation pattern formation. Patterns that are induced neither by heterogeneity in soil properties nor by the local topography are generally explained as the result of spatial self‐organization resulting from “symmetry‐breaking instability” in nonlinear systems. In this case, the spatial dynamics are able to destabilize the homogeneous state of the system, leading to the emergence of stable heterogeneous configurations. Both deterministic and stochastic mechanisms may explain the self‐organized vegetation patterns observed in nature. After an extensive analysis of deterministic theories, we review noise‐induced mechanisms of pattern formation and provide some examples of applications relevant to the environmental sciences.
A model for the rheology of particle‐bearing suspensions and partially molten rocks
Authors: Costa Antonio , Caricchi Luca , Bagdassarov Nickolai
Published: March 2009

This contribution presents a semiempirical model describing the effective relative viscosity of crystal‐bearing magmas as function of crystal fraction and strain rate. The model was applied to an extensive data set of magmatic suspensions and partially molten rocks providing a range of values for the fitting parameters that control the behavior of the relative viscosity curves as a function of the crystal fraction in an intermediate range of crystallinity (30–80 vol % crystals). The analysis of the results and of the materials used in the experiments allows for evaluating the physical meaning of the parameters of the proposed model. We show that the model, by varying the parameters within the ranges obtained during the fitting procedure, is able to describe satisfactory the effective relative viscosity as a function of crystal fraction and strain rate for suspensions having different geometrical characteristics of the suspended solid fraction.
Utilizing chromophoric dissolved organic matter measurements to derive export and reactivity of dissolved organic carbon exported to the Arctic Ocean: A case study of the Yukon River, Alaska
Authors: Spencer Robert G. M. , Aiken George R. , Butler Kenna D. , Dornblaser Mark M. , Striegl Robert G. , Hernes Peter J.
Published: March 2009

The quality and quantity of dissolved organic matter (DOM) exported by Arctic rivers is known to vary with hydrology and this exported material plays a fundamental role in the biogeochemical cycling of carbon at high latitudes. We highlight the potential of optical measurements to examine DOM quality across the hydrograph in Arctic rivers. Furthermore, we establish chromophoric DOM (CDOM) relationships to dissolved organic carbon (DOC) and lignin phenols in the Yukon River and model DOC and lignin loads from CDOM measurements, the former in excellent agreement with long‐term DOC monitoring data. Intensive sampling across the historically under‐sampled spring flush period highlights the importance of this time for total export of DOC and particularly lignin. Calculated riverine DOC loads to the Arctic Ocean show an increase from previous estimates, especially when new higher discharge data are incorporated. Increased DOC loads indicate decreased residence times for terrigenous DOM in the Arctic Ocean with important implications for the reactivity and export of this material to the Atlantic Ocean.
Large‐scale edge waves generated by hurricane landfall
Authors: Yankovsky Alexander E.
Published: March 2009

Direct observations of the storm surge induced by Hurricane Wilma's landfall revealed a formation of a wave pulse propagating alongshore. The height of the wave pulse exceeded 1.5 m in the detided sea level. The duration of this wave pulse was ∼6 h and the propagation speed was of O(10) m s−1. This wave has been identified as an edge wave of large spatial and temporal scales. A set of numerical experiments has been conducted to delineate a generation of edge waves with large spatial and temporal scales by a fast‐moving storm system. The model of the coastal ocean was set in a two‐dimensional configuration with the continental shelf and slope topography reminiscent of the West Florida shelf. A moving cyclonic system in the gradient wind balance was prescribed analytically. In order to identify a long wave response in the model, a linear boundary problem was solved, yielding dispersion characteristics and a structure of the edge wave modes. A fast‐moving storm system crossing the shelf at a right angle produces a nearly symmetrical response of two edge wave trains propagating both downstream (in the direction of a Kelvin wave) and upstream. Typically, zero‐mode edge waves dominate the response. As the translation speed of the storm becomes lower, its Eulerian timescale becomes longer and the waves are more affected by the Earth's rotation. In that case, the wave energy propagates predominantly downstream. When the storm trajectory deviates from the normal approach, the edge wave response is not symmetric: most of the energy propagates in the direction of the alongshore component of the storm translation velocity.
A model study of the effects of winds on concentric rings of gravity waves from a convective plume near Fort Collins on 11 May 2004
Authors: Vadas Sharon L. , Yue Jia , She Chiao‐Yao , Stamus Peter A. , Liu Alan Z.
Published: March 2009

Using a convective plume model and a ray trace model, we investigate the effects of winds on concentric rings of gravity waves (GWs) excited from a convective plume on 11 May 2004, near Fort Collins, Colorado. We find that winds can shift the apparent center of the concentric rings at z = 87 km from the plume location. We also find that critical level filtering (for GWs with small phase speeds propagating in the same direction as the wind) and wave reflection (for high‐frequency GWs with small horizontal wavelengths propagating in the opposite direction to the wind) prevent many GWs from reaching the OH airglow layer. Additionally, we find that strong winds disrupt the concentric ring patterns, causing distorted “squashed” ring and arc‐like patterns instead. Using a zero wind profile and a representative April mean zonal wind profile, we compare our model results with observations of concentric rings at the Yucca Ridge Field Station (40.7°N, 104.9°W). We find that the model horizontal wavelengths and periods agree reasonably well with the observed data. We also compare the model temperature perturbations with the temperature perturbations calculated from the intensity perturbations. Because the observations show less critical level filtering than from the April wind profile and more critical level filtering than from the zero wind profile, we conclude that the winds on 11 May were likely somewhat smaller than the April zonal wind profile assumed here.
Remote response of the East Asian winter monsoon to tropical forcing related to El Niño–Southern Oscillation
Authors: Sakai Kumi , Kawamura Ryuichi
Published: March 2009

The mechanism of the East Asian winter monsoon variability in response to El Niño−Southern Oscillation (ENSO)‐related tropical forcing is investigated using Japanese long‐term reanalysis project data, additionally aided by the Japan Meteorological Agency climate data assimilation system. There are at least two different responses, zonally symmetric and asymmetric, of the Asian jet over South Asia to the ENSO‐related tropical convective forcing during the Northern Hemisphere winter. The zonally symmetric response, induced by zonally extended anomalous convection from the Philippine Sea through southern India and Sri Lanka, is pronounced at the mature phase of ENSO. The zonally asymmetric response is intimately associated with anomalous convection localized in the vicinity of the Philippine and South China seas, accompanied by an anomalous Walker circulation cell between the Maritime Continent and tropical Indian Ocean. When this asymmetric response is prominent, ENSO‐related anomalous convection can give rise to a change in the East Asian winter monsoon system through stationary Rossby wave propagation along the South Asian waveguide. The North Atlantic Oscillation (NAO)‐related extratropical forcing is also a crucial factor and contributes not only to the downstream development of subpolar teleconnections across northern Eurasia but also to the reinforcement of the zonally asymmetric pattern of the Asian jet over South Asia, resulting in a significant effect on the East Asian winter monsoon circulation. A combination of the ENSO‐ and NAO‐related forcing plays a vital role in triggering the occurrence of extraordinary anomalous monsoon circulations, such as extremely heavy snowfall in the 2005/2006 winter in Japan.
Nutrition Through the Life Cycle
Authors: Emerton Victoria
Published: March 2009

Nutrition is viewed traditionally as the specific dietary requirements of different age groups, without exploring diet in the context of a life-long contributory factor to well-being. Nutrition Through the Life Cycle summarises what is known about the relationship between diet and health at different points in the life cycle, and the nutritional requirements of individuals of different ages. Nutrition policy and health promotion are discussed, together with how dietary interventions can provide long-term benefits to individuals and populations. Also covered are the major dietary challenges that exist in modern society, including the rise in incidence of obesity in both children and adolescents, anaemia in children and adolescents, and diet-related cancers. This book is published in association with Leatherhead Food International.
Imprecise probability assessment of tipping points in the climate system
Authors: Kriegler Elmar , Hall Jim W. , Held Hermann , Dawson Richard , Schellnhuber Hans Joachim
Published: March 2009

Major restructuring of the Atlantic meridional overturning circulation, the Greenland and West Antarctic ice sheets, the Amazon rainforest and ENSO, are a source of concern for climate policy. We have elicited subjective probability intervals for the occurrence of such major changes under global warming from 43 scientists. Although the expert estimates highlight large uncertainty, they allocate significant probability to some of the events listed above. We deduce conservative lower bounds for the probability of triggering at least 1 of those events of 0.16 for medium (2–4 °C), and 0.56 for high global mean temperature change (above 4 °C) relative to year 2000 levels.
Integrative self-sorting is a programming language for high level self-assembly
Authors: Jiang Wei , Schalley Christoph A.
Published: March 2009

Starting from the basis of a simple 4-component self-sorting system of crown ethers and ammonium ions, we design 6 building blocks in which 2 identical or different binding sites are incorporated. These building blocks can be mixed in many different ways to yield quite distinctly different pseudorotaxane assemblies. The self-sorting process integrates all building blocks in specific places so that this approach permits us to exert positional control and can widely influence the resulting assemblies with respect to the details of their structures. At maximum, we report quadruply interlocked species with up to 5 subunits that form specific assemblies. Although NMR methods are limited to the analysis of simpler complexes, ESI-MS and, in particular, tandem mass spectrometry is highly useful to analyze the assemblies' connectivities.
Amplification of the North American “Dust Bowl” drought through human-induced land degradation
Authors: Cook Benjamin I. , Miller Ron L. , Seager Richard
Published: March 2009

The “Dust Bowl” drought of the 1930s was highly unusual for North America, deviating from the typical pattern forced by “La Nina” with the maximum drying in the central and northern Plains, warm temperature anomalies across almost the entire continent, and widespread dust storms. General circulation models (GCMs), forced by sea surface temperatures (SSTs) from the 1930s, produce a drought, but one that is centered in southwestern North America and without the warming centered in the middle of the continent. Here, we show that the inclusion of forcing from human land degradation during the period, in addition to the anomalous SSTs, is necessary to reproduce the anomalous features of the Dust Bowl drought. The degradation over the Great Plains is represented in the GCM as a reduction in vegetation cover and the addition of a soil dust aerosol source, both consequences of crop failure. As a result of land surface feedbacks, the simulation of the drought is much improved when the new dust aerosol and vegetation boundary conditions are included. Vegetation reductions explain the high temperature anomaly over the northern U.S., and the dust aerosols intensify the drought and move it northward of the purely ocean-forced drought pattern. When both factors are included in the model simulations, the precipitation and temperature anomalies are of similar magnitude and in a similar location compared with the observations. Human-induced land degradation is likely to have not only contributed to the dust storms of the 1930s but also amplified the drought, and these together turned a modest SST-forced drought into one of the worst environmental disasters the U.S. has experienced.
A microraptorine (Dinosauria–Dromaeosauridae) from the Late Cretaceous of North America
Authors: Longrich Nicholas R. , Currie Philip J.
Published: March 2009

The fossil assemblages of the Late Cretaceous of North America are dominated by large-bodied dinosaur species. Associated skeletons of small dinosaurs are exceedingly rare, and small (<10 kg) carnivorous theropods have not previously been reported from these beds. Here, we describe a small dromaeosaurid from the 75-million-year-old Dinosaur Park Formation of Alberta, Canada.
Hesperonychus elizabethae
gen. et sp. nov. is represented by a pelvic girdle from an animal weighing ≈1,900 g. Despite its size, the pubes and ilia are coossified, indicating that the animal was somatically mature. This is the smallest carnivorous, nonavian dinosaur known from North America. Phylogenetic analysis of
Hesperonychus
reveals that it is not closely related to previously described North American dromaeosaurids. Instead,
Hesperonychus
is a member of the dromaeosaurid clade Microraptorinae, a group containing the 4-winged
Microraptor
and the feathered
Sinornithosaurus
, both from the Lower Cretaceous Jehol Group of China.
Hesperonychus
is the youngest known member of this lineage, extending the temporal range of the clade by 45 million years, and it is the first microraptorine known from North America, providing further evidence for an affinity between the dinosaur faunas of North America and Asia. Study of fossil collections from the Dinosaur Park and Oldman formations of Alberta has revealed numerous isolated bones of small, basal dromaeosaurids, which are tentatively referred to
Hesperonychus
. These fossils suggest that small dromaeosaurids were a significant component of the carnivore community in this Late Cretaceous biota.
Designed amphiphilic peptide forms stable nanoweb, slowly releases encapsulated hydrophobic drug, and accelerates animal hemostasis
Authors: Ruan Liping , Zhang Hangyu , Luo Hanlin , Liu Jingping , Tang Fushan , Shi Ying-Kang , Zhao Xiaojun
Published: March 2009

How do you design a peptide building block to make 2-dimentional nanowebs and 3-dimensional fibrous mats? This question has not been addressed with peptide self-assembling nanomaterials. This article describes a designed 9-residue peptide, N-Pro-Ser-Phe-Cys-Phe-Lys-Phe-Glu-Pro-C, which creates a strong fishnet-like nanostructure depending on the peptide concentrations and mechanical disruptions. This peptide is intramolecularly amphiphilic because of a single pair of ionic residues, Lys and Glu, at one end and nonionic residues, Phe, Cys, and Phe, at the other end. Circular dichroism and Fourier transform infrared spectroscopy analysis demonstrated that this peptide adopts stable β-turn and β-sheet structures and self-assembles into hierarchically arranged supramolecular aggregates in a concentration-dependent fashion, demonstrated by atomic force microscopy and electron microscopy. At high concentrations, the peptide dominantly self-assembled into globular aggregates that were extensively connected with each other to form “beads-on-a-thread” type nanofibers. These long nanofibers were extensively branched and overlapped to form a self-healing peptide hydrogel consisting of >99% water. This peptide can encapsulate the hydrophobic model drug pyrene and slowly release pyrene from coated microcrystals to liposomes. It can effectively stop animal bleeding within 30 s. We proposed a plausible model to interpret the intramolecular amphiphilic self-assembly process and suggest its importance for the future development of new biomaterials for drug delivery and regenerative medicine.
Alterations in left ventricular function and cardiac biomarkers as a consequence of repetitive endurance cycling
Authors: Williams Karen , Gregson Warren , Robertson Colin , Datson Naomi , Whyte Greg , Murrell Carissa , Wilson Luke , Ainslie Philip , Ross Emma , Shave Rob , Gaze David , George Keith
Published: March 2009

The aim of this study was to assess left ventricular (LV) function and cardiac biomarkers in response to repetitive endurance cycling over 22 days. Ten trained male cyclists (mean±s: age 40±5 years, VO2max 56±4 ml · kg−1 · min−1) completed the 2007 Tour de France route. Before, during, and 2 days after the Tour, all participants underwent an echocardiographic examination to determine ejection fraction, as well as systolic (S′), early diastolic (E′), and late diastolic (A′) myocardial tissue velocities, together with the E′:A′ ratio. Venous blood samples were collected and analysed for cardiac troponin I (cTnI) and B‐type‐natriuretic peptide. Repeated‐measures analysis of variance was used to investigate the cumulative effects of prolonged exercise bouts on LV function and cardiac biomarkers. Alpha was set at 0.05. Although both the ejection fraction (71±2% vs. 59±4%; P<0.05) and the E′:A′ ratio (1.60±0.15 vs. 1.09±0.12; P<0.05) were reduced at post‐stage assessments, there was limited evidence of a progressive decline in either variable over the 22 days. Although post‐tour ejection fraction was not different to baseline (68±3%; P>0.05), the E′:A′ ratio remained depressed (1.37±0.26; P<0.05) following 2 days of recovery. No cTnI was detectable at baseline and B‐type‐natriuretic peptide was within normal ranges (24±7 pg · ml−1). Cardiac troponin I was detectable in at least one cyclist at every assessment, with 60% being positive after stage 15 (range 0.02–0.09 µg · ml−1). B‐type‐natriuretic peptide peaked following stage 17 (240±145 pg · ml−1). In conclusion, repetitive endurance cycling resulted in an acute reduction in LV function and the sporadic appearance of cardiac biomarkers following each day of exercise. Despite this there was no cumulative effect of repetitive exercise. Minor changes in diastolic function persisted up to 48 h of recovery.
In search of nonribosomal nucleolar protein function and regulation
Authors: Pederson Thoru , Tsai Robert Y.L.
Published: March 2009

The life of the nucleolus has proven to be more colorful and multifaceted than had been envisioned a decade ago. A large number of proteins found in this subnuclear compartment have no identifiable tie either to the ribosome biosynthetic pathway or to the other newly established activities occurring within the nucleolus. The questions of how and why these proteins end up in this subnuclear compartment remain unanswered and are the focus of intense current interest. This review discusses our thoughts on the discovery of nonribosomal proteins in the nucleolus.
GSK3β phosphorylation modulates CLASP–microtubule association and lamella microtubule attachment
Authors: Kumar Praveen , Lyle Karen S. , Gierke Sarah , Matov Alexandre , Danuser Gaudenz , Wittmann Torsten
Published: March 2009

Polarity of the microtubule (MT) cytoskeleton is essential for many cell functions. Cytoplasmic linker–associated proteins (CLASPs) are MT-associated proteins thought to organize intracellular MTs and display a unique spatiotemporal regulation. In migrating epithelial cells, CLASPs track MT plus ends in the cell body but bind along MTs in the lamella. In this study, we demonstrate that glycogen synthase kinase 3β (GSK3β) directly phosphorylates CLASPs at multiple sites in the domain required for MT plus end tracking. Although complete phosphorylation disrupts both plus end tracking and association along lamella MTs, we show that partial phosphorylation of the identified GSK3β motifs determines whether CLASPs track plus ends or associate along MTs. In addition, we find that expression of constitutively active GSK3β destabilizes lamella MTs by disrupting lateral MT interactions with the cell cortex. GSK3β-induced lamella MT destabilization was partially rescued by expression of CLASP2 with mutated phosphorylation sites. This indicates that CLASP-mediated stabilization of peripheral MTs, which likely occurs in the vicinity of focal adhesions, may be regulated by local GSK3β inactivation.
‘What Troubled Children Need’ Constructions of Everyday Life in Residential Care
Authors: Jakobsen Turf Böcker
Published: March 2009

This article argues that key values of child protection work are not the appropriate point of departure for contemplating the welfare of children in professional care. Central values, such as ‘comfort’, ‘recognition’ or ‘appreciation’ say very little about the social practices of residential care. Using data from an ethnographic study in Denmark, the article demonstrates that ideas about the needs of troubled children are realised in dissimilar ways, creating highly different living environments for institutionalised children. The principles behind these construction processes are explored, and the profound ambiguity of values in childcare is discussed as an effect of residential care’s being an ‘institutional’ or ‘human service’ type of organisation.
Familial syringoma: Report of two cases with a published work review and the unique association with steatocystoma multiplex
Authors: MARZANO Angelo V. , FIORANI Roberta , GIRGENTI Valentina , CROSTI Carlo , ALESSI Elvio
Published: March 2009

Syringoma is a benign neoplasm of eccrine origin. Clinically, it manifests as small skin‐colored to yellowish soft papules usually localized around the eyes and on the upper cheeks of middle‐aged women. Familial cases have rarely been reported and may be inherited as an autosomal dominant trait or result from either germ line or somatic mutations. Syringoma can coexist with various conditions, notably Down syndrome. Herein, we report a family with multiple syringomas affecting members of three following generations and describe in detail a 36‐year‐old woman and her 17‐year‐old son. In the latter, steatocystoma multiplex, which is regarded as a benign cystic neoplasm of the folliculosebaceous unit or a nevoid malformation differentiated in the direction of the sebaceous duct, was associated. Acral distribution of steatocystoma multiplex and its presentation as subcutaneous nodules in this patient were unique.
Toxic epidermal necrolysis successfully treated with etanercept
Authors: GUBINELLI Emanuela , CANZONA Flora , TONANZI Tiziano , RASKOVIC Desanka , DIDONA Biagio
Published: March 2009

Toxic epidermal necrolysis (TEN) is a rare and acute severe adverse reaction to drugs, characterised by massive apoptosis and widespread epidermal and mucosal detachment. Although no gold standard therapy exists, human i.v. immunoglobulins have recently been described as an effective treatment for this disease. We report a case of phenobarbital‐induced TEN in a 59‐year‐old white woman where the epidermal detachment stopped 48 h after beginning the etanercept treatment with complete healing after 20 days. To the best of our knowledge, this is only the second reported case of TEN successfully treated with etanercept.
The familial aggregation of cannabis use disorders
Authors: Merikangas Kathleen R. , Li Julan Julia , Stipelman Brooke , Yu Kelly , Fucito Lisa , Swendsen Joel , Zhang Heping
Published: March 2009

Aims  The aim of this paper is to examine the familial aggregation of cannabis use disorders and other psychiatric conditions among first‐degree relatives and spouses of probands with a cannabis use disorder.

Design  Controlled family study methods.

Setting  Out‐patient psychiatric clinics and the local community (same geographic area).

Participants  Two hundred and sixty‐two probands with a life‐time history of cannabis use disorder, alcohol dependence, anxiety disorders or no history of any disorder, and their first‐degree relatives and spouses.

Measurements  Cannabis use disorders and other DSM‐III‐R disorders in the relatives and spouses using the Schedule for Affective Disorders and Schizophrenia.

Findings  Results reveal an elevated risk of life‐time history of cannabis use disorders among siblings [odds ratio (OR: 3.6), adult offspring (OR): 6.9], and spouses (OR: 4.4) of probands with cannabis use disorders. There is a latent familial factor underlying cannabis use disorders that was shared partially with alcohol abuse/dependence. Comorbid mood and anxiety disorders aggregated independently from cannabis use disorders in families. Equal elevation in the magnitude of the association among the first‐degree adult relatives and spouses of probands with a cannabis use disorder suggests the probable contribution of both environmental and genetic factors.

Conclusions  These findings support a family‐based approach to drug abuse intervention and the importance of future research concerning environmental mediators of familial transmission of drug abuse.
The clinical safety of long‐term lansoprazole for the maintenance of healed erosive oesophagitis
Authors: FRESTON J. W. , HISADA M. , PEURA D. A. , HABER M. M. , KOVACS T. O. , ATKINSON S. , HUNT B.
Published: March 2009

Background  The clinical safety of long‐term lansoprazole therapy for the maintenance of healed erosive oesophagitis has not been extensively studied in clinical trials.

Aim  To assess the long‐term clinical safety of dose‐titrated lansoprazole as maintenance therapy for up to 82 months in subjects with healed erosive oesophagitis.

Methods  Clinical safety was assessed by monitoring adverse events (AEs), laboratory data including serum gastrin levels, and endoscopy.

Results  Mean duration (± s.d.) of lansoprazole treatment during the titrated open‐label period was 56 ± 24 months (range <1–82 months). Overall, 189 of 195 (97%) subjects experienced a total of 2825 treatment‐emergent AEs. Most AEs occurred during the first year of treatment, were mild‐to‐moderate in severity and resolved while on treatment. Of 155 serious AEs (in 74 subjects), only two (colitis and rectal haemorrhage in one subject) were considered treatment‐related. Sixty‐nine of 195 subjects (35%) experienced 187 treatment‐related AEs, with diarrhoea (10%), headache (8%) and abdominal pain (6%) being the most common. Gastrin levels ≥400 pg/mL were seen in 9% of subjects; hypergastrinemia was not associated with gastro‐intestinal AEs or nodules/polyps.

Conclusions  Lansoprazole maintenance therapy for up to 6 years is safe and well tolerated in subjects with healed erosive oesophagitis.
Extramedullary plasmacytoma, a report of five cases diagnosed by FNAC
Authors: Sarin H. , Manucha V. , Verma K.
Published: March 2009

Objective:  To review cytological findings and diagnostic challenges in the use of fine needle aspiration in the diagnosis of extramedullary plasmacytoma.

Methods:  Five cases of extramedullary plasmacytoma that were initially diagnosed on fine needle aspiration cytology over a period of two years in Sir Ganga Ram Hospital were reviewed.

Results:  The cytological findings were similar in all five cases. The smears were cellular and composed of plasmacytoid cells arranged singly and in clusters, with varying pleomorphism, bi‐ and multinucleation and mitotic figures. Presence of anaplasia, increased plasmablasts, numerous naked nuclei and unusual location of the tumour were some of the challenges faced during the cytological evaluation.

Conclusions:  Extramedullary plasmacytoma may occur either as an initial presentation or as a secondary involvement by multiple myeloma. Fine needle aspiration is a reliable technique for its rapid diagnosis.
Plasma cell tumours: cytomorphological features in a series of 12 cases diagnosed on fine needle aspiration cytology
Authors: Handa U. , Chhabra S. , Mohan H.
Published: March 2009

U. Handa, S. Chhabra and H. Mohan Plasma cell tumours: cytomorphological features in a series of 12 cases diagnosed on fine needle aspiration cytology

Objective:  Plasma cell tumours represent autonomous proliferation of plasma cells and can manifest as multiple myeloma, monoclonal gammopathy of undetermined significance, variants of plasma cell myeloma or plasmacytoma.

Methods:  We report 12 cases of plasma cell tumours, which were initially diagnosed as plasmacytoma on fine needle aspiration cytology (FNAC). The patients were further subjected to bone marrow examination, serum electrophoresis, urine examination for Bence–Jones proteins, and x‐ray examination of the skeleton.

Results:  The cytological smears from all cases were cellular and showed numerous plasma cells in varying degrees of maturity. Subsequent to investigations, five cases were labelled as multiple myeloma with secondary extramedullary plasmacytoma, three as solitary bone plasmacytoma and two as primary extramedullary plasmacytoma. In the remaining two cases, bone marrow and urine examination findings were not available, so a conclusive diagnosis of multiple myeloma or solitary plasmacytoma could not be made.

Conclusion:  The study highlights the role of FNAC in the diagnosis of plasma cell tumours. Subsequent work‐up and follow‐up of these patients is important to rule out the presence of multiple myeloma.
Upward continuation with topographic datuming operator: the integrated wave equation datuming scheme revised
Authors: Yang Kai , Liu Yu‐Zhu , Geng Jian‐Hua , Ma Zai‐Tian
Published: March 2009

The integrated wave equation datuming scheme is an integrated datuming method to implement the wave equation velocity replacement with a one‐way extrapolator for overthrust data. The integrated wave equation datuming scheme is accomplished by downward continuing the data from the topography to a non‐planar base of the weathering layer, followed by an upward continuation from the base of the weathering layer to a final planar datum. Both the downward and the upward continuation are accomplished by a one‐way extrapolator by a classical ‘two‐step’ implementation. The topographic datuming operator is a distinctive technique by which the shots and receivers are downward continued simultaneously. Although its inadaptability to non‐planar datum and the strong lateral variation of the near‐surface structure constrains its application to the downward continuation of the overthrust data, we found that the ‘one‐step’ feature of the topographic datuming operator is extremely suitable for the upward continuation. In this paper, the topographic datuming operator is incorporated into the integrated wave equation datuming scheme to perform upward continuation instead of a one‐way extrapolator – thus a revised integrated wave equation datuming scheme is constructed. Compared with the previous scheme, the computatiol cost of the revised integrated wave equation datuming scheme is greatly reduced, thus the applicability of the integrated wave equation datuming scheme is further improved. The synthetic and real data examples demonstrate its effectiveness and efficiency.
Patterns of mortality for each life‐history stage in a population of the endangered New Zealand stitchbird
Authors: Low Matthew , Pärt Tomas
Published: March 2009

Using data from 396 breeding attempts over an 8‐year period, we investigated age‐ and stage‐specific survival rates and their modifying factors in a closed island population of the New Zealand stitchbird (or hihi,Notiomystis cinctaDu Bus).

Survival probability generally increased over time; however, at each life‐history transition, survival in the new stage started lower than at the end of the previous stage, creating a ‘saw‐tooth’ function of age‐related survival.

The probability of an egg hatching was low (0·73 ± 0·01): most likely a consequence of genetic bottlenecks previously endured by this population. There was strong support for a positive relationship between hatching rate and the subsequent survival of the female parent, and hatching success declining for females > 4 years old.

Nestling survival probability increased as a function of brood size and days since hatching, and decreased relative to daily maximum ambient temperature and hatching date. Support for models including ambient temperature was greater than for other covariates, with the majority of this temperature‐mediated survival effect being restricted to the early nestling stage.

Fledglings had low survival rates in the first two weeks after leaving the nest, with post‐fledging survival related to the fledgling's mass. Two months after fledging, juvenile survival probability plateaued and remained relatively constant for the following autumn, winter and spring/summer breeding season. There was no effect of sex or season on adult survival probability. However, there was strong support for age‐specific variation in adult survival, with survival likelihood increasing during the first four years before showing evidence of a senescence decline.

Within‐stage survival increases were likely related to stage‐specific selection pressures initially weeding out individuals of poorer phenotypes for the environment specific to each life‐history stage. Such a mechanism explains the initial high mortality at life‐history transitions; a well‐adapted phenotype for one stage may not necessarily be so well adapted for subsequent stages. These patterns are not only valuable for examining life‐history theory, but also for understanding the regulation of vital rates in an endangered species and providing a basis from which better population management models and harvesting regimes can be derived.