bluuebunny/crossref_metadata_2025 huggingface dataset:
III.—The Water Basin of Lough Derg, Ireland
Authors: Kinahan G. Henry
Published: May 2009

Some time since, I read before the Geological Society of Glasgow a paper on “The Valley of Loch Lomond,” and pointed out that the deeps and shallows corresponded with, the faults and breaks in the adjoining country. This paper was quoted by His Grace the Duke of Argyll, President of the London Geological Society, in opposition to the view (so ably advocated by Professor Ramsay) that ice has been the principal, if not the only, agent engaged in the formation of such hollows.
IV.—On the Northerly Extension of the Old Red Sandstone to Linley, and other Geological Features of the Valley of Linley Brook
Authors: Randall John
Published: May 2009

Two remarkable geological features present themselves in this little valley: one, the occurrence of the Upper Coal Measures of Bewdley, together with the well-known Spirorbis Limestone; the other, that of the Bone-bed, succeeded by the no less interesting Passage-beds, forming connecting links between the Old Red, Sandstone and Upper Ludlow Limestone. The order in which these occur, taking both banks of the brook, appears to be this.
IV.—History of the Names Cambrian and Silurian in Geology
Authors: Hunt T. Sterry
Published: May 2009

In accordance with our plan, we now proceed to sketch the history of the Lower Palæozoic rocks in North America. While European geologists were carrying out the researches which have been described in the first and second parts of this paper, American investigators were not idle. The geological studies of Eaton led the way to a systematic survey of the State of New York, the results of which have been the basis of most of the subsequent geological work in eastern North America, and which was begun by legislative enactment in 1836.
III.—On the Coal-bearing Rocks of Southern Chile
Authors: Lebour G. A.
Published: May 2009

Little as the Geology of South America has been worked, yet the presence of coal along the coast of Chile has long been known to navigators and others. Of late years this coal has been worked in sundry places—in short, wherever the circumstances seemed most favourable. The strata in which the seams occur, were made the subject of considerable study from a palæontological point of view by D'Orbigny and by Darwin; but not until the last ten or fifteen years have the resources of the country, with regard to this branch of industry, been examined into sufficiently to enable a correct estimate to be made of them. The surveys, which have been the direct result of the interest awakened by the knowledge of the presence of workable seams of lignite in Chile, have been greatly conducive to a more perfect knowledge of the geological structure of the coast; and the consequent accumulation of material for its study has, we believe, brought it within our power, not only to add to the very limited stock of notes on the subject, but also, it is hoped, to give such explanations of some of the more obscure facts connected therewith as were, from the want of reliable data, either overlooked by earlier observers, or only vaguely suggested by them.
IV.—On Supposed Pholas Burrows in Derbyshire
Authors: Bonney T. G.
Published: May 2009

During a short vacation visit to Derbyshire I have had the opportunity of making some further notes on burrows in limestone rocks, which may be worth recording. These burrows, it will be remembered, have been attributed by Messrs. Darbyshire, Mackintosh, and others, to the action of Pholades, a conclusion which I ventured to oppose, after an examination of several instances in the neighbourhood of Llandudno. Mr. Darbyshire calls attention, in his paper, to the occurrence of these burrows near Buxton, on Grin Edge and Harper Hill, at a height of about 1400 feet above the sea. I was therefore fully prepared to meet with them in the Carboniferous Limestone in other parts of the county.
II.—Descriptions of two New Species of Fossil Tubicolar Annelides
Authors: Nicholson H. Alleyne
Published: May 2009

In a recent paper (American Journal of Science and Arts, vol. iii., March, 1872), I founded a new genus, under the name of Conchicolites, for the reception of some singular Tubicolar Annelides found growing upon the shells of Orthocerata in the Lower Silurian of the North of England.
III.—Notes on Calceola sandalina, Lamarck
Authors: Stebbing T. R. R.
Published: May 2009

Calceola sandalina, both by its generic and specific name, means a little shoe or slipper. It is a common fossil in the Devonian rocks of the Eifel and other continental localities, and was found years ago by Mr. Godwin-Austen at Ogwell, near Chircombe Bridge, in Devonshire.
EDUCATING WOMEN FOR DEVELOPMENT: THE ARAB HUMAN DEVELOPMENT REPORT 2005 AND THE PROBLEM WITH WOMEN'S CHOICES
Authors: Adely Fida J.
Published: May 2009

The Arab Human Development Report 2005, the fourth in a series that has received much acclaim and stirred much controversy, takes up the issue of women's development in the Arab world. Through a careful reading and analysis of sections of the report that address education and economic participation, this paper offers a critique of the human capabilities framework that frames this report. I highlight critical tensions between the claim that providing education is an essential element of expanding choices and the assumptions embedded in discussions about women and education regarding which choices are acceptable and/or desirable. These tensions point to the persistence of values derived from the mandates of global capital, albeit in the new language of neoliberal choice, revealing that ‘human development’ does not represent a significant departure from earlier conceptualizations of development. I draw on my ethnographic research in Jordan as one example to interrogate such assumptions and to shed light on the ambiguities built into the educational project for young women today.
Anatomy of a Scare: Yellow Peril Politics in America, 1980–1993
Authors: HEALE M. J.
Published: May 2009

This article maps the rise and dissemination of Yellow Peril fears in the United States between about 1980 and 1993 and seeks to explain them. Anti-communism had been an animating force in Ronald Reagan's career, but shortly after he left office an opinion poll revealed that Japan had replaced the Soviet Union as the greatest perceived threat to the US. While economic anxieties contributed to the resurgence of Yellow Peril sentiments, this article emphasizes the vital parts played by other phenomena, notably Reagan's economic policies, partisan politics, a media war, and the ending of the Cold War. The Yellow Peril scare was widely criticized, and by the early 1990s the controversy had invaded popular culture. Ronald Reagan is frequently applauded for restoring American self-confidence after the “malaise” of the Carter years, but the apprehensions discussed here suggest that he enjoyed only limited success in this respect.
“Meet the Real Lena Horne”: Representations of Lena Horne in Ebony Magazine, 1945–1949
Authors: WILLIAMS MEGAN E.
Published: May 2009

Following World War II, Ebony's creator and editor, John H. Johnson, sought to create a popular black magazine in the vein of Life and Look that would reflect the accomplishments and joys, “the happier side,” of African American life.1 Throughout the first four years of its publication, Lena Horne appeared on the magazine's cover three times – the only woman to do so during this period. In this paper, I argue that the fledgling Ebony magazine drew on Lena Horne's wartime status as a beautiful black icon and represented her as a symbol of its ideological project, broadly, and as the Ebony image of postwar black womanhood, specifically. The magazine's representation of Lena Horne acts as a useful trope for understanding how Ebony imaged postwar black femininity in terms of motherhood, work, and civil rights activism; additionally, Ebony's representation of Horne and Ebony readers' letters to the editor reveal central issues of respectability, pinup photography, colorism, hair care, and interracial relationships as they were debated within the magazine's pages.

Behind the lavish make-up, gay tinsel and brilliant glitter of American's most popular Negro entertainer, Lena Horne is a wonderfully human, somewhat lonesome, amazingly-honest, militant-minded personality who is relatively unknown to a vast audience of millions of movie, radio, and night club fans.2
Nabokov's Dystopia: Bend Sinister, America and Mass Culture
Authors: NORMAN WILL
Published: May 2009

“I am as American as April in Arizona,” Nabokov claimed in a 1966 interview. Although he repeatedly emphasized his American citizenship and the affection he held for his adopted nation, my argument is that his 1947 novel, Bend Sinister, offers us an opportunity to interrogate the received narrative of Nabokov's unproblematic arrival and assimilation into the United States. In examining the engagement with mass culture in this dystopian novel, my intention is to restore some of the political valence denied the novel by both Nabokov and his readers, and to suggest how it functions as a critique of American culture which reveals the author's profound ambivalence about his adopted nation in the early to mid-1940s. Drawing on unpublished archive material, as well as theoretical work by Theodor Adorno, this paper opens up a new approach to Nabokov's American work and demands a reassessment of his avowed apoliticism.
On shear sheltering and the structure of vortical modes in single- and two-fluid boundary layers
Authors: ZAKI TAMER A. , SAHA SANDEEP
Published: May 2009

Studies of vortical interactions in boundary layers have often invoked the continuous spectrum of the Orr–Sommerfeld (O-S) equation. These vortical eigenmodes provide a link between free-stream disturbances and the boundary-layer shear – a link which is absent in the inviscid limit due to shear sheltering. In the presence of viscosity, however, a shift in the dominant balance in the operator determines the structure of these eigenfunctions inside the mean shear. In order to explain the mechanics of shear sheltering and the structure of the continuous modes, both numerical and asymptotic solutions of the linear perturbation equation are presented in single- and two-fluid boundary layers. The asymptotic analysis identifies three limits: a convective shear-sheltering regime, a convective–diffusive regime and a diffusive regime. In the shear-dominated limit, the vorticity eigenfunction possesses a three-layer structure, the topmost being a region of exponential decay. The role of viscosity is most pronounced in the diffusive regime, where the boundary layer becomes ‘transparent’ to the oscillatory eigenfunctions. Finally, the convective–diffusive regime demonstrates the interplay between the the accumulative effect of the shear and the role of viscosity. The analyses are complemented by a physical interpretation of shear-sheltering mechanism. The influence of a wallfilm, in particular viscosity and density stratification, and surface tension are also evaluated. It is shown that a modified wavenumber emerges across the interface and influences the penetration of vortical disturbances into the two-fluid shear flow.
Mixed bottom-friction–Kelvin–Helmholtz destabilization of source-driven abyssal overflows in the ocean
Authors: SWATERS GORDON E.
Published: May 2009

Source-driven ocean currents that flow over topographic sills are important initiation sites for the abyssal component of the thermohaline circulation. These overflows exhibit vigorous space and time variability over many scales as they progress from a predominately gravity-driven downslope flow to a geostrophic along-slope current. Observations show that in the immediate vicinity of a sill, grounded abyssal ocean overflows can possess current speeds greater than the local long internal gravity wave speed with bottom friction and downslope gravitational acceleration dominating the flow evolution. It is shown that these dynamics lead to the mixed frictionally induced and Kelvin–Helmholtz instability of grounded abyssal overflows. Within the overflow, the linearized instabilities correspond to bottom-intensified baroclinic roll waves, and in the overlying water column amplifying internal gravity waves are generated. The stability characteristics are described as functions of the bottom drag coefficient and slope, Froude, bulk Richardson and Reynolds numbers associated with the overflow and the fractional thickness of the abyssal current compared to the mean depth of the overlying water column. The marginal stability boundary and the boundary separating the parameter regimes in which the most unstable mode has a finite or infinite wavenumber are determined. When it exists, the high-wavenumber cutoff is obtained. Conditions for the possible development of an ultraviolet catastrophe are determined. In the infinite-Reynolds-number limit, an exact solution is obtained which fully includes the effects of mean depth variations in the overlying water column associated with a sloping bottom. For parameter values characteristic of the Denmark Strait overflow, the most unstable mode has a wavelength of about 19 km, a geostationary period of about 14 hours, an e-folding amplification time of about 2 hours and a downslope phase speed of about 74 cm s−1.
Viscous sheet retraction
Authors: SAVVA NIKOS , BUSH JOHN W. M.
Published: May 2009

We present the results of a combined theoretical and numerical investigation of the rim-driven retraction of flat fluid sheets in both planar and circular geometries. Particular attention is given to the influence of the fluid viscosity on the evolution of the sheet and its bounding rim. In both geometries, after a transient that depends on the sheet viscosity and geometry, the film edge eventually attains the Taylor–Culick speed predicted on the basis of inviscid theory. The emergence of this result in the viscous limit is rationalized by consideration of both momentum and energy arguments. We first consider the planar geometry considered by Brenner & Gueyffier (Phys. Fluids, vol. 11, 1999, p. 737) and deduce new analytical expressions for the speed of the film edge at the onset of rupture and the evolution of the maximum film thickness for viscous films. In order to consider the expansion of a circular hole, we develop an appropriate lubrication model that predicts the form of the early stage dynamics of film rupture. Simulations of a broad range of flow parameters confirm the importance of geometry on the dynamics, verifying the exponential hole growth reported in early experimental studies. We demonstrate the sensitivity of the initial retraction speed on the film profile, and so suggest that the anomalous rate of retraction reported in these experiments may be attributed in part to geometric details of the puncture process.
Gradient trajectory analysis of a scalar field with external intermittency
Authors: MELLADO JUAN PEDRO , WANG LIPO , PETERS NORBERT
Published: May 2009

The passive scalar field of a temporally evolving shear layer is investigated using gradient trajectories as a means to analyse the scalar probability density function and the conditional scalar dissipation rate in the presence of external intermittency. These results are of significance for turbulent combustion, where improved predictions of the statistics of the conditional dissipation rate are needed in several models. First, the variation of the conventional first and second moments of the conditional dissipation rate across the layer is quantitatively documented in detail. A strong dependence of the conditional dissipation rate on the lateral position and on the conditioning value of the scalar is observed. The dependence on the transverse distance to the centre-plane partially explains the double-hump profile usually reported when this dependence is ignored. The variation with the scalar observed in the ratio between the second and first moments would invalidate certain assumptions commonly done in turbulent combustion. It is also seen that conditioning on the scalar does not reduce the fluctuation of the dissipation rate with respect to unconditional values. Next, the role of external intermittency in these results is investigated. For that purpose, the flow is partitioned into different zones based on different types of gradient trajectories passing through each point, thereby introducing non-local information in comparison with the standard turbulent/non-turbulent separation based on the conventional intermittency function. In addition to the homogeneous outer regions, three zones are identified: a turbulent zone, a turbulence interface and quasi-laminar diffusion layers. The relative contribution from each of these zones to the conventional intermittency factor is reported. The statistics are then conditioned on each of these zones, and the spatial variation of the scalar distribution and of the conditional scalar dissipation rate is explained in terms of the observed zonal statistics. For the Reynolds numbers of the present simulation, between 1500 and 3000 based on the vorticity thickness and the velocity difference, and a Schmidt number equal to 1, it results that the major contribution to both statistics is due to the turbulence interfaces. At the same time, the turbulent zone shows a distinct behaviour, being approximately homogeneous but anisotropic.
Nonlinear dynamics of core-annular film flows in the presence of surfactant
Authors: KAS-DANOUCHE S. A. , PAPAGEORGIOU D. T. , SIEGEL M.
Published: May 2009

The nonlinear stability of two-phase core-annular flow in a cylindrical pipe is studied. A constant pressure gradient drives the flow of two immiscible liquids of different viscosities and equal densities, and surface tension acts at the interface separating the phases. Insoluble surfactants are included, and we assess their effect on the flow stability and ensuing spatio-temporal dynamics. We achieve this by developing an asymptotic analysis in the limit of a thin annular layer – which is usually the relevant regime in applications – to derive a coupled system of nonlinear evolution equations that govern the dynamics of the interface and the local surfactant concentration on it. In the absence of surfactants the system reduces to the Kuramoto–Sivashinsky (KS) equation, and its modifications due to viscosity stratification (present when the phases have unequal viscosities) are derived elsewhere. We report on extensive numerical experiments to evaluate the effect of surfactants on KS dynamics (including chaotic states, for example), in both the absence and the presence of viscosity stratification. We find that chaos is suppressed in the absence of viscosity differences and that the new flow consists of successive windows (in parameter space) of steady-state travelling waves separated by time-periodic attractors. The intricate structure of the travelling pulses is also explained physically. When viscosity stratification is present we observe a transition from time-periodic dynamics, for instance, to steady-state travelling wave pulses of increasing amplitudes and speeds. Numerical evidence is presented that indicates that the transition occurs through a reverse Feigenbaum cascade in phase space.
CRITICAL NOTICE: MACROJUSTICE AS A RESEARCH PROGRAMME
Authors: Schokkaert Erik
Published: May 2009

In this book, the French economist and philosopher Serge-Christophe Kolm discusses the problem of what he calls “macrojustice”, which “concerns the most general rules of society and their application to the distribution of the benefits from the main resources” (MJ 1). He reminds his readers that the first and most important challenge for any policy analysis is the spelling out of its ethical foundations. On that basis, he argues in favour of what is nothing less than a paradigm shift in the theory of optimal income taxation, rejecting the whole traditional approach in public economics as being welfarist and too strongly focused on the problem of labour market distortions. As an alternative, he proposes an approach based on the ideal of equal freedom, and works out a specific tax proposal: equal-labour income equalization (or ELIE). He claims that ELIE is a general and operational solution for the organization of the distribution branch of taxation and public expenditure policy that does not create labour market distortions.
Richter's Wagner: a new source for tempi in Das Rheingold
Authors: ALLIS MICHAEL
Published: May 2009

Despite the number of musicological studies that have focused upon Wagner's theories of tempo modification, the basic speeds adopted in early performances of Wagner's music dramas have been more difficult to identify. This article focuses upon an important new source of information concerning Wagnerian performance – a list of metronome timings made by Edward Dannreuther at the first dress rehearsal of Das Rheingold at Bayreuth in July 1876. After considering the practical difficulties of tempo measurement, and briefly placing the broad implications of Dannreuther's timings in the context of Wagner's theories and practice, the dress rehearsal tempi are examined in more detail in terms of their potential for practical realisation in performance. Six readings of Das Rheingold from the recorded canon (Bodanzky, Furtwängler, Knappertsbusch, Solti, Karajan, Boulez) provide a suitable comparative perspective from which to discuss how these tempi might affect perceptions of physical distance, the nature of motifs related to characters or events, tempo relationships within a musical scene, and larger-scale tempo connections in Das Rheingold as a whole. In particular, the very quick tempi identified by Dannreuther (especially in relation to modern sensibilities) might encourage a reassessment of practical possibilities in the realisation of Wagner's scores, along with a reconsideration of Wagner's music and its meanings.

I know of no conductor whom I could trust to perform my music correctly … on the evening of the final performance of Twilight of the Gods in Bayreuth … what … had reduced me to such despair … was my horror at realizing that my conductor [Hans Richter] – in spite of the fact that I consider him the best I know – was not able to maintain the correct tempo, however often he got it right, because – he was incapable of knowing why the music had to be interpreted in one way and not another. – For this is the very heart of the matter: anyone may succeed by chance at least once, but he is not aware of what he is doing, – for I alone could have justified it by means of what I call my school.1

I am persistently returning to the question of tempo because, as I said before, this is the point at which it becomes evident whether a conductor understands his business or not.2
Soil moisture conditions affect the sensitivity ofBromus catharticusdormant seeds to light and the emergence pattern of seedlings
Authors: Mollard Federico P.O. , Insausti Pedro
Published: May 2009

The soil moisture regime may affect dormancy of seeds and their sensitivity to signals that promote germination. We studied the effect of moisture regime on the sensitivity to light of dormantBromus catharticusseeds, and on the emergence pattern of seedlings. Seeds were incubated under continuously hydrated, continuously dehydrated, or fluctuating moisture regimes in a controlled environment (25°C, darkness) for 2 months. After moisture treatments, seeds were exposed to red or far-red light pulses, or to darkness, to determine germinability. In addition, grassland mesocosms with intact seed bank and vegetation were irrigated or subjected to a drought regime in a glasshouse at summer temperatures. After 2 months, the temperature was reduced to correspond to grassland temperatures in autumn; the canopy was removed and half of the mesocosms were covered with filters that exclude red light. Density ofB. catharticusseedlings was evaluated after 2 weeks. Dormancy decreased in continuously hydrated seeds but they still required red light for germination. In contrast, an important fraction of seeds that experienced continuously dehydrated or fluctuating moisture regimes germinated in darkness or after far-red light pulses. In the mesocosms that had experienced a soil drought, a higher density of seedlings emerged in the absence of red light than in the daily irrigated mesocosms. This indicates that a fraction ofB. catharticusseeds acquired the capability to germinate under the canopy, especially in the drought moisture regime. Results indicate that the soil moisture environment experienced during dormancy affects the sensitivity to light ofB. catharticusseeds, as well as the emergence pattern of seedlings.
Längsschnittliche Effekte von Zielorientierungen auf Dimensionen des beruflichen Belastungserlebens im Lehrberuf
Authors: Tönjes Britt , Dickhäuser Oliver
Published: May 2009

Zusammenfassung. Die Zielorientierungstheorie konnte als Rahmen zur Beschreibung von Erleben im Lehrberuf belegt werden ( Butler, 2007 ). Querschnittliche Zusammenhänge zwischen beruflichen Zielorientierungen und Dimensionen des Belastungserlebens nach Maslach im Lehrberuf konnten ebenfalls bereits aufgezeigt werden ( Tönjes, Dickhäuser & Kröner, 2008 ). Basierend auf einem theoriegeleiteten Modell wird mittels zweier Pfadanalysen in dieser Studie geprüft, welche längsschnittlichen Effekte die beruflichen Zielorientierungen auf die Leistungsmangelwahrnehmung und die emotionale Erschöpfung nach Maslach haben. In Studie I mit N = 96 Lehrkräften hat die Vermeidungsleistungszielorientierung einen positiven längsschnittlichen Effekt auf Leistungsmangelwahrnehmung und emotionale Erschöpfung. Die Lernzielorientierung hat einen negativen Effekt auf die emotionale Erschöpfung. Die Annäherungsleistungszielorientierung hat einen marginalen negativen Effekt auf die Leistungsmangelwahrnehmung. In Studie II mit N = 80 Lehramtsanwärtern hat die Vermeidungsleistungszielorientierung ebenfalls einen positiven und die Annäherungsleistungszielorientierung einen negativen längsschnittlichen Effekt auf die Leistungsmangelwahrnehmung und die emotionale Erschöpfung. Die Befunde unterstreichen die Relevanz der Zielorientierungstheorie für das Verständnis von Belastungserleben im Lehrberuf.
Circulation responses to snow albedo feedback in climate change
Authors: Fletcher Christopher G. , Kushner Paul J. , Hall Alex , Qu Xin
Published: May 2009

Climate change is expected to cause a reduction in the spatial extent of snow cover on land. Recent work suggests that this will exert a local influence on the atmosphere and the hydrology of snow‐margin areas through the snow‐albedo feedback (SAF) mechanism. A significant fraction of variability among IPCC AR4 general circulation model (GCM) predictions for future summertime climate change over these areas is related to the models' representation of springtime SAF. In this study, we demonstrate a nonlocal influence of SAF on the summertime circulation in the extratropical Northern Hemisphere. Increased land surface warming in models with stronger SAF is associated with large‐scale sea‐level pressure anomalies over the northern oceans and a poleward intensified subtropical jet. We find that up to 25–30% and, on average, 5–10% of the inter‐model spread in projections of the circulation response to climate change is linearly related to SAF strength.
Phosphoinositide 3-kinases and their role in inflammation: potential clinical targets in atherosclerosis?
Authors: Fougerat Anne , Gayral Stéphanie , Malet Nicole , Briand-Mesange Fabienne , Breton-Douillon Monique , Laffargue Muriel
Published: May 2009

Inflammation has a central role in the pathogenesis of atherosclerosis at various stages of the disease. Therefore it appears of great interest to develop novel and innovative drugs targeting inflammatory proteins for the treatment of atherosclerosis. The PI3K (phosphoinositide 3-kinase) family, which catalyses the phosphorylation of the 3-OH position of phosphoinositides and generates phospholipids, controls a wide variety of intracellular signalling pathways. Recent studies provide evidence for a crucial role of this family not only in immune function, such as inflammatory cell recruitment, and expression and activation of inflammatory mediators, but also in antigen-dependent responses making it an interesting target to modulate inflammatory processes. The present review will focus on the regulation of inflammation within the vasculature during atherogenesis. We will concentrate on the different functions played by each isoform of PI3K in immune cells which could be involved in this pathology, raising the possibility that inhibition of one or more PI3K isoforms may represent an effective approach in the treatment of atherosclerosis.
Is Expressive Language Disorder an Accurate Diagnostic Category?
Authors: Leonard Laurence B.
Published: May 2009

Purpose

To propose that the diagnostic category of “expressive language disorder” as distinct from a disorder of both expressive and receptive language might not be accurate.

Method

Evidence that casts doubt on a pure form of this disorder is reviewed from several sources, including the literature on genetic findings, theories of language impairments, and the outcomes of late talkers with expressive language delays. Areas of language that are problematic in production but not readily amenable to comprehension testing are also discussed.

Conclusions

The notion of expressive language disorder has been formalized in classification systems and is implicit if not explicit in the organization of many standardized tests. However, a close inspection of the evidence suggests that deficits in language expression are typically accompanied by limitations in language knowledge or difficulties processing language input. For this reason, the diagnostic category of expressive language disorder should be used with considerable caution. This view has implications for both research and clinical practice.
Inactivation of expression of several genes in a variety of bacterial species by EGS technology
Authors: Shen Ning , Ko Jae-hyeong , Xiao Gaoping , Wesolowski Donna , Shan Ge , Geller Bruce , Izadjoo Mina , Altman Sidney
Published: May 2009

The expression of gene products in bacteria can be inhibited by the use of RNA external guide sequences (EGSs) that hybridize to a target mRNA. Endogenous RNase P cleaves the mRNA in the complex, making it inactive. EGSs participate in this biochemical reaction as the data presented here show. They promote mRNA cleavage at the expected site and sometimes at other secondary sites. Higher-order structure must affect these reactions if the cleavage does not occur at the defined site, which has been determined by techniques based on their ability to find sites that are accessible to the EGS oligonucleotides. Sites defined by a random EGS technique occur as expected. Oligonucleotides made up primarily of defined or random nucleotides are extremely useful in inhibiting expression of the
gyrA
and
rnpA
genes from several different bacteria or the
cat
gene that determines resistance to chloramphenicol in
Escherichia coli
. An EGS made up of a peptide-phosphorodiamidate morpholino oligonucleotide (PPMO) does not cleave at the same site as an unmodified RNA EGS for reasons that are only partly understood. However, PPMO-EGSs are useful in inhibiting the expression of targeted genes from Gram-negative and Gram-positive organisms during ordinary growth in broth and may provide a basis for broad-spectrum antibiotics.
Evolution under canalization and the dual roles of microRNAs—A hypothesis
Authors: Wu Chung-I , Shen Yang , Tang Tian
Published: May 2009

Canalization refers to the process by which phenotypes are stabilized within species. Evolution by natural selection can proceed efficiently only when phenotypes are canalized. The existence and identity of canalizing genes have thus been an important, but controversial topic. Recent evidence has increasingly hinted that microRNAs may be involved in canalizing gene expression. Their paradoxical properties (e.g., strongly conserved but functionally dispensable) suggest unconventional regulatory roles. We synthesized published and unpublished results and hypothesize that miRNAs may have dual functions—in gene expression tuning and in expression buffering. In tuning, miRNAs modify the mean expression level of their targets, but in buffering they merely reduce the variance around a preset mean. In light of the constant emergence of new miRNAs, we further discuss the relative importance of these two functions in evolution.
Adaptive evolution of young gene duplicates in mammals
Authors: Han Mira V. , Demuth Jeffery P. , McGrath Casey L. , Casola Claudio , Hahn Matthew W.
Published: May 2009

Duplicate genes act as a source of genetic material from which new functions arise. They exist in large numbers in every sequenced eukaryotic genome and may be responsible for many differences in phenotypes between species. However, recent work searching for the targets of positive selection in humans has largely ignored duplicated genes due to complications in orthology assignment. Here we find that a high proportion of young gene duplicates in the human, macaque, mouse, and rat genomes have experienced adaptive natural selection. Approximately 10% of all lineage-specific duplicates show evidence for positive selection on their protein sequences, larger than any reported amount of selection among single-copy genes in these lineages using similar methods. We also find that newly duplicated genes that have been transposed to new chromosomal locations are significantly more likely to have undergone positive selection than the ancestral copy. Human-specific duplicates evolving under adaptive natural selection include a surprising number of genes involved in neuronal and cognitive functions. Our results imply that genome scans for selection that ignore duplicated loci are missing a large fraction of all adaptive substitutions. The results are also in agreement with the classical model of evolution by gene duplication, supporting a common role for neofunctionalization in the long-term maintenance of gene duplicates.
The Genus Polypterus (Bichirs): A Fish Group Diverged at the Stem of Ray-Finned Fishes (Actinopterygii)
Authors: Takeuchi Masaki , Okabe Masataka , Aizawa Shinichi
Published: May 2009

INTRODUCTION

Axis and germ-layer formations are central issues in vertebrate embryology that can be examined in the zebrafish, Xenopus, chick, and mouse. An intriguing question is how the mechanisms that existed in an ancestral vertebrate have been modified during vertebrate evolution. A major stream of vertebrates (Osteichthyes) evolved in two monophyletic lineages: the Sarcopterygii and Actinopterygii. The zebrafish is a well-known and well-studied teleost fish highly derived in the actinopterygian lineage, ray-finned fishes. The early cleavage pattern of teleosts is meroblastic, in contrast to the holoblastic cleavage seen in amphibians, which diverged early in the sarcopterygian lineage. There are many differences in the molecular and cellular mechanisms of embryogenesis between teleosts and amphibians or actinopterygians and sarcopterygians, including the differences in bauplan (body plan). However, the lineage leading to the teleost fishes has undergone a whole-genome duplication before their radiation, which may have also caused changes in molecular usage independent of the teleost bauplan. Polypterus diverged from all other actinopterygians ~400 million years ago (Mya) during the Devonian period, soon after the divarication of an ancestral bony fish into Actinopterygii and Sarcopterygii. Polypterus is thus uniquely well suited for studies assessing the ancestral state or bauplan of Osteichthyes and Actinopterygii, as well as the divergence of embryogenetic processes in teleosts and amphibians.
Construction and Characterization of Adenovirus Vectors
Authors: Ross P. Joel , Parks Robin J.
Published: May 2009

INTRODUCTION

Genetically modified adenoviruses (Ads) make attractive vectors for the delivery of exogenous DNA to mammalian cells for basic science and gene therapy applications. Ad vector production consists of (1) cloning a transgene into an infectious plasmid by in vivo recombination in bacteria, (2) rescuing and propagating the vector in complementing cells, and (3) purifying the vector. All of this can be accomplished using commercially available reagents, plasmids, and cell lines. First-generation Ads have a large cloning capacity (5-14 kbp) and efficiently transduce a wide range of both quiescent and proliferating cell types. They are readily propagated to produce high-titer stocks (1011-1013 vector particles from a 3-L culture). Furthermore, Ads rarely integrate into the host genome and are relatively safe. However, Ad vector production typically takes 4-6 wk, and promiscuous host-cell transduction can occur in vivo. Furthermore, immune responses against viral proteins encoded by the vector backbone can occur, which limits the duration of transgene expression in vivo. Regardless of these limitations, Ad remains one of the more versatile and efficient gene delivery systems. Here, we discuss methods for the generation, propagation, purification, and characterization of first-generation Ad vectors.
Whole-Mount In Situ Hybridization of Bichir (Polypterus) Embryos
Authors: Takeuchi Masaki , Okabe Masataka , Aizawa Shinichi
Published: May 2009

INTRODUCTION

Axis and germ-layer formations are central issues in vertebrate embryology. An intriguing question is how the mechanisms that existed in an ancestral vertebrate have been modified during vertebrate evolution. A major stream of vertebrates (Osteichthyes) evolved in two monophyletic lineages: the Sarcopterygii and Actinopterygii. There are many differences in the molecular and cellular mechanisms of embryogenesis between teleosts (actinopterygians) and amphibians (sarcopterygians), including the differences in bauplan (body plan). Polypterus diverged from all other actinopterygians ~400 million years ago (Mya) during the Devonian period, soon after the divarication of an ancestral bony fish into Actinopterygii and Sarcopterygii. Polypterus is thus uniquely well suited for studies assessing the ancestral state or bauplan of Osteichthyes and Actinopterygii, as well as the divergence of embryogenetic processes in teleosts and amphibians. This protocol describes a method for in situ hybridization in Polypterus embryos.
Dissection of Larval and Pupal Wings from the African Butterfly Bicyclus anynana
Authors: Brakefield Paul M. , Beldade Patrícia , Zwaan Bas J.
Published: May 2009

INTRODUCTION

This protocol describes a procedure for the dissection of larval and pupal wings from the African butterfly Bicyclus anynana. Dissected pupal wings can be used subsequently for in situ hybridization or for immunohistochemistry. They can also be analyzed with stereomicroscopy to study scale maturation and pigment deposition.
Constant Volume Respirometry in the African Butterfly Bicyclus anynana
Authors: Brakefield Paul M. , Beldade Patrícia , Zwaan Bas J.
Published: May 2009

INTRODUCTION

This protocol describes the use of constant volume respirometry to measure CO2 production by the African butterfly Bicyclus anynana. The instrument used is the TR-2 system from Sable Systems International. In this setup, dry CO2-free air is sequentially pumped through 16 sealed chambers. The CO2 produced by the butterflies is subsequently measured with an infrared CO2 detector. CO2 production (μL/ h) by individual butterflies is an index of the resting metabolic rate (RMR). The RMR of each individual is corrected for weight, preferably after removal of water and fat mass, to allow comparison of the RMRs among individuals.
Super under‐actuated multi‐fingered mechanical hand with modular self‐adaptive gear‐rack mechanism
Authors: Zhang Wenzeng , Che Demeng , Liu Hongbin , Ma Xiande , Chen Qiang , Du Dong , Sun Zhenguo
Published: May 2009

Purpose

The purpose of this paper is to present recent work designing a mechanical robotic hand for self‐adaptive grasping, human‐like appearance, which can be used in a humanoid robot. Conventional robotic devices are relatively complex, large, cumbersome and difficult to be installed in a humanoid robot arm. Under‐actuated robot hands use less motors to drive more rotating joints, thus to simplify the mechanical structure, decrease the volume and weight and finally lower the difficulty of control and the cost.

Design/methodology/approach

A novel under‐actuated finger mechanism is designed, which is based on a gear‐rack mechanism, spring constraint and an active sleeve middle phalanx. The principle analyses of its self‐adaptive grasp and end power grasping are given. A new multi‐fingered hand named as TH‐3R Hand is designed based on the finger.

Findings

The design finger mechanism can be used in a robotic hand to make the hand obtain more degrees of freedom (DOF) with fewer actuators, and good grasping function of shape adaptation, decrease the requirement of control system. TH‐3R Hand has five fingers, 15 DOF. All fingers are similar. TH‐3R Hand has many advantages: it is simple in structure, light in weight, easy to control and low in cost. TH‐3R Hand can passively adapt different shapes and sizes of the grasped object. Experimental studies have demonstrated the self‐adaptation in grasping of the finger.

Research limitations/implications

The implication of this research is that under‐actuated robotic hands are appropriate for the missions of grasping different objects. The limitation of the research to date is that issues of sensors, control, and communication have not yet been addressed.

Practical implications

Key technologies of the under‐actuated finger and TH‐3R Hand, with self‐adaptive grasping, human‐like appearance and low‐cost lightweight, are feasible. These technologies have the potential to make a significant impact.

Originality/value

These results present a self‐adaptive under‐actuated grasp concept and a humanoid robotic hand with under‐actuated gear‐rack mechanism.
Unintended consequences of race‐based segmentation strategies
Authors: Davidson Edith F.
Published: May 2009

Purpose

The purpose of this paper is to review the pitfalls and potentials of segmentation decisions based on the visible demographic variable of race.

Design/methodology/approach

The paper takes as its approach a review of assumptions and values of use of race as a marketing segmentation strategy, but places them against the inherent dangers that could be overlooked in a retail environment. The paper's purpose is to note the misuse of the planning tool of segmentation.

Findings

Dealing with race‐driven decisions could create an unwelcome or even segregating situation with potential for customer loss or even discrimination. The business needs to understand how to attract and retain customers of all types.

Originality/value

It is easy to forget that people of any type could be valued customers, and no store should, intentionally or otherwise, desire to discourage some customers at the expense of gaining others.
Mandated change gone wrong? A case study of law‐based school reform in South Africa
Authors: Bisschoff Tom
Published: May 2009

Purpose

This paper aims to explore and describe the limits of recent law‐based school reform in South Africa from an education management perspective.

Design/methodology/approach

The research design consists of a qualitative, investigative, descriptive and contextual design which Merriam would classify as a basic or generic design type.

Findings

The findings revealed specific problems associated with recent mandated changes in South African schools. These were classified as categories (themes) within the research design and described in detail: lack of local skills capacity at school and district levels; the “knowing and doing” gap; the tensions created by legal issues between teachers and learners; too many changes too rapidly; bureaucratic red tape; top‐down approach; contextual factors.

Research limitations/implications

The paper explored the problems associated with mandated changes in South African schools in one province. The sample is very limited and therefore further study is needed to fully understand the lack of implementation in the 25,139 public schools country wide.

Originality/value

This paper recognises the seminal work done by De Mitchell and Fossey on the limits of law‐based school reform but adds illumination on the lack of implementation of mandated changes within the South African context.
An application of Six Sigma methodology to turnover intentions in health care
Authors: Tolga Taner Mehmet , Sezen Bulent
Published: May 2009

Purpose

The purpose of this study is to show how the principles of Six Sigma can be applied to the high turnover problem of doctors in medical emergency services and paramedic backup.

Design/methodology/approach

Six Sigma's define‐measure‐analyse‐improve‐control (DMAIC) is applied for reducing the turnover rate of doctors in an organisation operating in emergency services. Variables of the model are determined. Explanatory factor analysis, multiple regression, analysis of variance (ANOVA) and Gage R&R are employed for the analysis.

Findings

Personal burnout/stress and dissatisfaction from salary were found to be the “vital few” variables. The organisation took a new approach by improving its initiatives to doctors' working conditions. Sigma level of the process is increased. New policy and process changes have been found to effectively decrease the incidence of turnover intentions. The improved process is gained, standardised and institutionalised.

Originality/value

This study is one of the few papers in the literature that elaborates the turnover problem of doctors working in the emergency and paramedic backup services.
Audit of an inpatient liaison psychiatry consultation service
Authors: Lyne John , Hill Michelle , Burke Patricia , Ryan Martina
Published: May 2009

Purpose

The purpose of this paper is to examine an audit that was performed of all patients referred to a liaison psychiatry inpatient consultation service which sought to establish a baseline for demographics, type of referral, and management of referrals, with a view to introducing improved evidence‐based treatments. It also aims to examine timeliness of response to referrals benchmarked against published standards.

Design/methodology/approach

All inpatient referrals to a liaison psychiatry service were recorded over a six‐month period, including demographics, diagnosis, management and timeliness of response to referrals. The data were retrospectively analysed and compared against international standards.

Findings

A total of 172 referrals were received in the six months. Commonest referral reasons included assessments regarding depressive disorders (23.8 per cent), delirium/other cognitive disorders (19.2 per cent), alcohol‐related disorders (18.6 per cent), anxiety disorders (14.5 per cent), and risk management (12.2 per cent). Evidence‐based practices were not utilised effectively for a number of different types of presentations. A total of 40.1 per cent of referrals were seen on the same day, 75.4 per cent by the end of the next day, and 93.4 per cent by the end of the following day.

Practical implications

Use of a hospital protocol for management of delirium may improve outcomes for these patients. Evidence‐based techniques, such as brief intervention therapies, may be beneficial for referrals involving alcohol dependence. Referrals were seen reasonably quickly, but there is room for improvement when compared with published standards.

Originality/value

This paper provides valuable information for those involved in management of liaison psychiatry consultation services, providing ideas for development and implementation of evidence based practices.