bluuebunny/crossref_metadata_2025 huggingface dataset:
Drug delivery through the skin: molecular simulations of barrier lipids to design more effective noninvasive dermal and transdermal delivery systems for small molecules, biologics, and cosmetics
Authors: Torin Huzil J. , Sivaloganathan Siv , Kohandel Mohammad , Foldvari Marianna
Published: May 2011

The delivery of drugs through the skin provides a convenient route of administration that is often preferable to injection because it is noninvasive and can typically be self‐administered. These two factors alone result in a significant reduction of medical complications and improvement in patient compliance. Unfortunately, a significant obstacle to dermal and transdermal drug delivery alike is the resilient barrier that the epidermal layers of the skin, primarily the stratum corneum, presents for the diffusion of exogenous chemical agents. Further advancement of transdermal drug delivery requires the development of novel delivery systems that are suitable for modern, macromolecular protein and nucleotide therapeutic agents. Significant effort has already been devoted to obtain a functional understanding of the physical barrier properties imparted by the epidermis, specifically the membrane structures of the stratum corneum. However, structural observations of membrane systems are often hindered by low resolutions, making it difficult to resolve the molecular mechanisms related to interactions between lipids found within the stratum corneum. Several models describing the molecular diffusion of drug molecules through the stratum corneum have now been postulated, where chemical permeation enhancers are thought to disrupt the underlying lipid structure, resulting in enhanced permeability. Recent investigations using biphasic vesicles also suggested a possibility for novel mechanisms involving the formation of complex polymorphic lipid phases. In this review, we discuss the advantages and limitations of permeation‐enhancing strategies and how computational simulations, at the atomic scale, coupled with physical observations can provide insight into the mechanisms of diffusion through the stratum corneum. WIREs Nanomed Nanobiotechnol 2011 3 449–462 DOI: 10.1002/wnan.147

This article is categorized under:

Therapeutic Approaches and Drug Discovery > Emerging Technologies

Implantable Materials and Surgical Technologies > Nanomaterials and Implants

Nanotechnology Approaches to Biology > Nanoscale Systems in Biology
Laparoscopic Repair of Duodenal Atresia: Revisited
Authors: van der Zee David C.
Published: May 2011

Background

Since the initial reports of laparoscopic repair of duodenal atresia in neonates, further reports have been scant. Could this be because of unacceptable rates of complications, like anastomotic leakage, as mentioned in later reports? In the present study the laparoscopic repair of duodenal atresia in neonates is revisited.

Patients

Group 1 consisted of 22 patients with duodenal obstruction between 2000–2005 until the laparoscopic approach was abandoned. Of these 22 patients, 10 had Down syndrome and 8 had concomitant malformations. In this group 18 patients were operated laparoscopically. Four patients underwent an open procedure. Group 2 consisted of six patients that underwent operation between 2008 and February 2010.

Results

In group 1 there were four conversions. In 14 patients the procedure could be completed laparoscopically. In five patients postoperative leakage occurred. The complication rate was found to be unacceptably high, and the laparoscopic approach was abandoned. After gaining additional experience in intracorporeal suturing and adjusting the technique, the procedure was started up again in 2008. Since then six consecutive neonates have undergone laparoscopic repair of duodenal atresia without complications.

Conclusions

Laparoscopic repair of duodenal atresia is one of the most demanding pediatric laparoscopic surgical procedures. After initial promising results at the beginning of the twenty‐first century a relative “radio silence“ followed, apparently caused by unsatisfactory results. Only considerable adjustments in technique and extensive improvement in experience has led to acceptable outcomes more recently. Laparoscopic repair of duodenal atresia should therefore be restricted to pediatric centers with extensive experience in laparoscopic surgery and intracorporeal suturing.
Androgeninsensitivität
Authors: Wieacker P. , Ledig S.
Published: May 2011

Mutationen des Androgenrezeptorgens sind mit einem Spektrum von Störungen assoziiert, die von der kompletten Androgeninsensitivität mit weiblichem äußerem Genitale über die partielle Androgeninsensitivität mit intersexuellem Genitale bis zur minimalen Androgeninsensitivität mit männlicher Infertilität reichen. Das CAG-Repeat im 1. Exon ist für die Transaktivierung von Zielgenen bedeutsam und moduliert androgenabhängige Prozesse. Eine pathologische Expansion dieses Repeats verursacht die X-chromosomale spinobulbäre Muskelatrophie.
The emerging role of magnetic resonance imaging and multidetector computed tomography in the diagnosis of dilated cardiomyopathy
Authors: Slavich Massimo , Florian Anca , Bogaert Jan
Published: May 2011

Magnetic resonance imaging and multidetector computed tomography are new imaging methods that have much to offer clinicians caring for patients with dilated cardiomyopathy. In this article we briefly describe the clinical, pathophysiological and histological aspects of dilated cardiomyopathy. Then we discuss in detail the use of both imaging methods for measurement of chamber size, global and regional function, for myocardial tissue characterisation, including myocardial viability assessment, and determination of arrhythmogenic substrate, and their emerging role in cardiac resynchronisation therapy.
The moderating role of contextual factors on quality management practices
Authors: Zhang Dongli , Linderman Kevin , Schroeder Roger G.
Published: May 2011

This study investigates how contextual factors influence the relationship between Quality Management (QM) practices and manufacturing performance. It contributes to the contingency theory of QM effectiveness. Drawing on the management literature, we differentiate two different groups of QM practices: Quality Exploitation and Quality Exploration. The analysis empirically investigates the internal fit with organizational structure and the external fit with environmental uncertainty on the relationship between Quality Exploration, Quality Exploitation, and operational performance. The data comes from a survey of 238 manufacturing plants in three industries across eight countries. Regression analyses show that both internal fit with the organizational structure and external fit with the environment affect performance. The findings also provide insights for managers on how to customize QM programs to achieve optimal performance benefits. In stable environments Quality Exploitation practices provide the best performance outcomes, while in a dynamic environment Quality Exploration practices with an organic organizational structure give the best results.
Proteomic comparison of human embryonic stem cells with their differentiated fibroblasts: Identification of 206 genes targeted by hES cell‐specific microRNAs
Authors: Tsai Zong‐Yun , Chou Chi‐Hsien , Lu Chi‐Yu , Singh Sher , Yu Sung‐Liang , Li Steven Shoei‐Lung
Published: May 2011

Human embryonic stem (hES)‐T3 (T3ES) cells were spontaneously differentiated into autogeneic fibroblast‐like T3DF cells, as feeder cells with the capacity to support the growth of undifferentiated hES cells. The proteomes of undifferentiated T3ES cells and their differentiated T3DF fibroblasts were quantitatively compared. Several heterogeneous nuclear ribonucleoproteins and glycolytic enzymes, including l‐lactate dehydrogenase A (M), were found to be abundantly and differentially expressed in T3ES cells and T3DF fibroblasts, respectively. Both miRNA and mRNA profiles from the undifferentiated T3ES cells and their differentiated T3DF fibroblasts had been previously determined. In this investigation, 206 genes were found to be targets of the four hES cell‐specific miRNAs of miR‐302d, miR‐372, miR‐200c, and/or miR‐367 by using two‐fold differential expression and inverse expression levels (highly negative correlations) of miRNAs to their target mRNAs. That YWHAZ (14‐3‐3 zeta) is a target of miR‐302d and miR‐372 was further confirmed by proteomic comparison between T3ES cells and their differentiated T3DF fibroblasts. According to GeneOntology analyses, almost 50% of these 206 target proteins are nuclear and are involved in gene transcription. Identifying the target mRNAs of hES cell‐specific miRNAs will provide a better understanding of the complex regulatory networks in hES cells. Furthermore, these miRNA‐targeted proteins play important roles in differentiation of hES cells and during embryo development.
Parties, Coalitions, and the Internal Organization of Legislatures
Authors: DIERMEIER DANIEL , VLAICU RAZVAN
Published: May 2011

We present a theory of parties-in-legislatures that can generate partisan policy outcomes despite the absence of any party-imposed voting discipline. Legislators choose all procedures and policies through majority-rule bargaining and cannot commit to vote against their preferences on either. Yet, off-median policy bias occurs in equilibrium because a majority of legislators with correlated preferences has policy-driven incentives to adopt partisan agenda-setting rules—as a consequence, bills reach the floor disproportionately from one side of the ideological spectrum. The model recovers, as special cases, the claims of both partisan and nonpartisan theories in the ongoing debate over the nature of party influence in the U.S. Congress. We show that (1) party influence increases in polarization, and (2) the legislative median controls policy making only when there are no bargaining frictions and no polarization. We discuss the implications of our findings for the theoretical and empirical study of legislatures.
Enantiomeric selectivity in behavioural and electrophysiological responses of Aedes aegypti and Culex quinquefasciatus mosquitoes
Authors: Cook J.I. , Majeed S. , Ignell R. , Pickett J.A. , Birkett M.A. , Logan J.G.
Published: May 2011

1-Octen-3-ol is a kairomone for many haematophagous insects including mosquitoes. Numerous studies have examined the effects of racemic 1-octen-3-ol; however, few studies have investigated the role of individual enantiomers in relation to mosquito attraction. In the present study, we investigated the behavioural and electrophysiological responses of two mosquito species, Aedes aegypti and Culex quinquefasciatus, to individual enantiomers and mixtures of 1-octen-3-ol, employing a laboratory Y-tube olfactometer and single sensillum recordings. The olfactory receptor neurons of both Ae. aegypti and Cx. quinquefasciatus had a significantly higher response to the (R)-1-octen-3-ol enantiomer compared to the (S)-1-octen-3-ol enantiomer at 10−9 g μl−1 to 10−6 g μl−1. Behaviourally, Ae. aegypti was more responsive to the (R)-1-octen-3-ol enantiomer, showing an increase in flight activity and relative attraction compared to Cx. quinquefasciatus. The (R)-1-octen-3-ol enantiomer caused an increase in activation for Cx. quinquefasciatus. However, the most notable effect was from an (R:S)-1-octen-3-ol mixture (84:16) that caused significantly more mosquitoes to sustain their flight and reach the capture chambers (demonstrated by a reduced non-sustained flight activity), suggesting that it may have a behaviourally excitatory effect. For Cx. quinquefasciatus, a reduced relative attraction response was also observed for all treatments containing the (R)-1-octen-3-ol enantiomer, either on its own or as part of a mixture, but not with the (S)-1-octen-3-ol enantiomer. This is the first time enantiomeric selectivity has been shown for Ae. aegypti using electrophysiology in vivo. The implications of these results for exploitation in mosquito traps are discussed.
Physiological trade-offs of forming maggot masses by necrophagous flies on vertebrate carrion
Authors: Rivers D.B. , Thompson C. , Brogan R.
Published: May 2011

Necrophagous flies that colonize human and animal corpses are extremely efficient at locating and utilizing carrion. Adult flies deposit eggs or larvae on the ephemeral food resource, which signals the beginning of intense inter- and intra-species competition. Within a short period of time after egg hatch, large larval aggregations or maggot masses form. A period of intense larval feeding ensues that will culminate with consumption/decomposition of all soft tissues associated with the corpse. Perhaps the most distinctive feature of these feeding aggregations is heat production; that is, the capacity to generate internal heat that can exceed ambient temperatures by 30°C or more. While observations of maggot mass formation and heat generation have been described in the research literature for more than 50 years, our understanding of maggot masses, particularly the physiological ecology of the aggregations as a whole, is rudimentary. In this review, an examination of what is known about the formation of maggot masses is presented, as well as arguments for the physiological benefits and limitations of developing in feeding aggregations that, at times, can represent regions of intense competition, overcrowded conditions, or a microclimate with elevated temperatures approaching or exceeding proteotoxic stress levels.
Species-specific treatment effects of helminth/HIV-1 co-infection: a systematic review and meta-analysis
Authors: SANGARÉ LAURA R. , HERRIN BRADELY R. , JOHN-STEWART GRACE , WALSON JUDD L.
Published: May 2011

In sub-Saharan Africa, over 22 million people are estimated to be co-infected with both helminths and HIV-1. Several studies have suggested that de-worming individuals with HIV-1 may delay HIV-1 disease progression, and that the benefit of de-worming may vary by individual helminth species. We conducted a systematic review and meta-analysis of the published literature to determine the effect of treatment of individual helminth infections on markers of HIV-1 progression (CD4 count and HIV viral load). There was a trend towards an association between treatment for Schistosoma mansoni and a decrease in HIV viral load (Weighted mean difference (WMD)=−0·10; 95% Confidence interval (CI): −0·24, 0·03), although this association was not seen for Ascaris lumbricoides, hookworm or Trichuris trichiura. Treatment of A. lumbricoides, S. mansoni, hookworm or T. trichiura was not associated with a change in CD4 count. While pooled data from randomized trials suggested clinical benefit of de-worming for individual helminth species, these effects decreased when observational data were included in the pooled analysis. While further trials are needed to confirm the role of anthelmintic treatment in HIV-1 co-infected individuals, providing anthelmintics to individuals with HIV-1 may be a safe, inexpensive and practical intervention to slow progression of HIV-1.
Eradication and control of livestock ticks: biological, economic and social perspectives
Authors: WALKER ALAN R.
Published: May 2011

Comparisons of successful and failed attempts to eradicate livestock ticks reveal that the social context of farming and management of the campaigns have greater influence than techniques of treatment. The biology of ticks is considered principally where it has contributed to control of ticks as practiced on farms. The timing of treatments by life cycle and season can be exploited to reduce numbers of treatments per year. Pastures can be managed to starve and desiccate vulnerable larvae questing on vegetation. Immunity to ticks acquired by hosts can be enhanced by livestock breeding. The aggregated distribution of ticks on hosts with poor immunity can be used to select animals for removal from the herd. Models of tick population dynamics required for predicting outcomes of control methods need better understanding of drivers of distribution, aggregation, stability, and density-dependent mortality. Changing social circumstances, especially of land-use, has an influence on exposure to tick-borne pathogens that can be exploited for disease control.
Geographical and host distribution patterns of Parvicapsula minibicornis (Myxozoa) small subunit ribosomal RNA genetic types
Authors: ATKINSON STEPHEN D. , JONES SIMON R. M. , ADLARD ROBERT D. , BARTHOLOMEW JERRI L.
Published: May 2011

Parvicapsula minibicornis is a myxozoan parasite implicated in mortalities of both juvenile and pre-spawning adult salmon in the Pacific Northwest of North America. Disease severity and presentation varies between salmon species and geographical localities. To better characterize population structure of the parasite, we sought genetic markers in the P. minibicornis ribosomal RNA gene. We compared samples from California with the type specimen from British Columbia, identified sequence variations, and then sequenced 197 samples from fish, river water and the parasite's polychaete worm host. Although DNA sequences of the parasite were >98·9% similar, there was enough variation to define 15 genotypes. All genotypes were detected in fish samples, although not in all species. A single genotype only was found in sockeye and pink salmon in the Fraser River Basin, but was not detected in sockeye from the adjacent Columbia River Basin. All coho salmon, irrespective of river basin, were infected with a unique mix of 2 genotypes. These data indicated that the P. minibicornis population exhibited strong signals of structuring by both geography and salmonid host species. Particular genotypes may correlate with disease differences seen in salmon populations in the Pacific Northwest.
Psychophysical scaling: Judgments of attributes or objects?
Authors: Lockhead Gregory R.
Published: May 2011

Psychophysical scaling models of the form R = f(I), with R the response and I some intensity of an attribute, all assume that people judge the amounts of an attribute. With simple biases excepted, most also assume that judgments are independent of space, time, and features of the situation other than the one being judged. Many data support these ideas: Magnitude estimations of brightness (R) increase with luminance (I). Nevertheless, I argue that the general model is wrong. The stabilized retinal image literature shows that nothing is seen if light does not change over time. The classification literature shows that dimensions often combine to produce emergent properties that cannot be described by the elements in the stimulus. These and other effects cannot be adjusted for by simply adding variables to the general model because some factors do not combine linearly. The proposed alternative is that people initially judge the entire stimulus – the object in terms of its environment. This agrees with the constancy literature that shows that objects and their attributes are identified through their relations to other aspects of the scene. That the environment determines judgments is masked in scaling studies where the standard procedure is to hold context constant. In a typical brightness study (where different lights are presented on the same background on different trials) the essential stimulus might be the intensity of the light or a difference between the light and the background. The two are perfectly confounded. This issue is examined in the case of audition. Judgments of the loudness of a tone depend on how much that tone differs from the previous tone in both pitch and loudness. To judge loudness (and other attributes) people first seem to process the stimulus object in terms of differences between it and other aspects in the situation; only then do they assess the feature of interest. Psychophysical judgments will therefore be better interpreted by theories of attention that are based in biology or psychology than those (following Fechner) that are based in classical physics.
What connectionist models learn: Learning and representation in connectionist networks
Authors: Hanson Stephen José , Burr David J.
Published: May 2011

Connectionist models provide a promising alternative to the traditional computational approach that has for several decades dominated cognitive science and artificial intelligence, although the nature of connectionist models and their relation to symbol processing remains controversial. Connectionist models can be characterized by three general computational features: distinct layers of interconnected units, recursive rules for updating the strengths of the connections during learning, and “simple” homogeneous computing elements. Using just these three features one can construct surprisingly elegant and powerful models of memory, perception, motor control, categorization, and reasoning. What makes the connectionist approach unique is not its variety of representational possibilities (including “distributed representations”) or its departure from explicit rule-based models, or even its preoccupation with the brain metaphor. Rather, it is that connectionist models can be used to explore systematically the complex interaction between learning and representation, as we try to demonstrate through the analysis of several large networks.
Functional specialization in the lower and upper visual fields in humans: Its ecological origins and neurophysiological implications
Authors: Previc Fred H.
Published: May 2011

Functional specialization in the lower and upper visual fields in humans is analyzed in relation to the origins of the primate visual system. Processing differences between the vertical hemifields are related to the distinction betweennear(peripersonal) andfar(extrapersonal) space, which are biased toward the lower and upper visual fields, respectively.Nonlinear/globalprocessing is required in the lower visual field in order to pergeive the optically degraded and diplopic images in near vision, whereas objects in far vision are searched for and recognized primarily usinglinear/localperceptual mechanisms. The functional differences between near and far visual space are correlated with their disproportionate representations in thedorsalandventraldivisions of visual association cortex, respectively, and in themagnocellularandparvocellularpathways that project to them. Advances in far visual capabilities and forelimb manipulatory skills may have led to a significant enhancement of these functional specializations.
Provenance changes between recent and glacial-time sediments in the Amundsen Sea embayment, West Antarctica: clay mineral assemblage evidence
Authors: Ehrmann Werner , Hillenbrand Claus-Dieter , Smith James A. , Graham Alastair G.C. , Kuhn Gerhard , Larter Robert D.
Published: May 2011

The Amundsen Sea embayment is a probable site for the initiation of a future collapse of the West Antarctic Ice Sheet. This paper contributes to a better understanding of the transport pathways of subglacial sediments into this embayment at present and during the last glacial period. It discusses the clay mineral composition of sediment samples taken from the seafloor surface and marine cores in order to decipher spatial and temporal changes in the sediment provenance. The most striking feature in the present-day clay mineral distribution is the high concentration of kaolinite, which is mainly supplied by the Thwaites Glacier system and indicates the presence of hitherto unknown kaolinite-bearing sedimentary strata in the hinterland, probably in the Byrd Subglacial Basin. The main illite input is via the Pine Island Glacier. Smectite originates from the erosion of volcanic rocks in Ellsworth Land and western Marie Byrd Land. The clay mineral assemblages in diamictons deposited during the last glacial period are distinctly different from those in corresponding surface sediments. This relationship indicates that glacial sediment sources were different from modern ones, which could reflect changes in the catchment areas of the glaciers and ice streams.
Clinical Ethics Committees in Norway: What Do They Do, and Does It Make a Difference?
Authors: FØRDE REIDUN , PEDERSEN REIDAR
Published: May 2011

The first clinical ethics committees (CEC) in Norway were established in 1996. This started as an initiative from hospital clinicians, the Norwegian Medical Association, and health authorities and politicians. Norwegian hospitals are, by and large, publicly funded through taxation, and all inpatient treatment is free of charge. Today, all the 23 hospital trusts (providing specialized and hospital-based healthcare services to the Norwegian population of 4.9 million people) have established at least one committee. Center for Medical Ethics (SME), University of Oslo, receives an annual amount of US$335,000 from the Ministry of Health and Care Services to coordinate the committees and to facilitate competency building for committee members.
DOMESTIC SERVANTS, MIDNIGHT MEETINGS, AND THE MAGDALEN'S FRIEND AND FEMALE HOMES’ INTELLIGENCER
Authors: Rogers Scott
Published: May 2011

Published monthly from April 1860 until 1864, The Magdalen's Friend and Female Homes’ Intelligencer was a periodical with a very specific mission. Launched at the height of the mid-Victorian concern with prostitution – when institutions devoted to the reclamation of penitent prostitutes began to emerge across Britain – it only ceased publication after the sudden death of its editor, the Reverend William Tuckniss. In its opening issue, the editors describe their explicit purpose: “Christians and Philanthropists who are now labouring single-handed [in the cause of reclaiming prostitutes and fallen women] will here find a rallying point, where they may exchange words of encouragement and advice, and confer with others who are their Fellow-labourers in the same cause” (“Opening Address” 1.1 1–2). It was, then, a trade publication for a movement that had grown remarkably – seven years after its founding in 1853, the Society for the Rescue of Young Women and Children (commonly known as the “Rescue Society”) was operating twelve houses of reclamation in London.
LESSONS FROM THE GUTTER: SEX AND CONTAMINATION IN THE WAY WE LIVE NOW
Authors: Bleicher Elizabeth
Published: May 2011

Felix Carbury's name is a classically Trollopian bit of fun. The heir to the Carbury family estate is dubbed with the Latinate for “happy and fortunate” when Felix is in fact the active agent of its sorrow, loss of fortune, and impending demise. Though Felix's gambling, drinking, and indolence are the practices most dangerous to his family, Anthony Trollope frames his sexual habits as most dangerous to society and young readers. The narrator and other characters aptly call Felix “vicious” (21; ch.2, 132; ch. 17, 540; ch. 71), which is etymologically rooted in “vice.” Margaret Markwick's assertion that “viciousness” was Trollope's regular reference to “carnality or sexual licentiousness” (95) is helpful in understanding how Felix, and his fate, are being made to function in the discussion of male sexuality in which the novel engages. As a result of improper sexual liaisons, Felix descends from the status of eligible, aristocratic bachelor to contaminating social pariah. In the process, he ends up walking the streets in a parody of the desperation and police harassment that Victorian fallen women faced; loses his beauty in a symbolic disfigurement that mirrors the ravages of syphilis; and ends up banished not merely from his community but from the entire country. The plot explicitly states that Felix is exiled to prevent him from inflicting financial harm on women, but Felix's participation in the extratextual discourse on men's sexuality required that he also be expelled from the sexual economy to contain his potential for transmitting sexual contagion.
REVOLUTIONIZING ELIZABETH BARRETT BROWNING: A REVIEW OF THE COMPLETE WORKS OF ELIZABETH BARRETT BROWNING
Authors: Chapman Alison
Published: May 2011

Any attempt to edit EBB's works encounters immediate and overwhelming challenges. The manuscripts, together with letters, books, drawings, and works of art, were more or less blown to the four corners of the globe with the 1913 Sotheby's sale of her son “Pen” Browning's estate. As Philip Kelley and Betty A. Coley put it, this has been considered “a disaster” by scholars (ix). Kelley and Coley's magnificent reconstruction of the contents of Pen's estate, The Browning Collections, lists each item and whereabouts, if known (the reference aid is updated at The Brownings: A Research Guidehttp://www.browningguide.org/). It is a disheartening as well as essential reading for the researcher, for its catalogue includes academic and public libraries, private collection and associations, throughout North America and Europe. Although locating those Browning effects is now easier with The Browning Collections, should the scholar have funds for travel, the manuscripts themselves are in a perilous state. Not only are they often fragile (especially the important tiny notebooks) but also often extremely challenging to read because of the spidery, faint, and often illegible handwriting. Barrett Browning often revised her poems and had false starts, and sometimes one poem in manuscript is entwined into another. They are, as EBB herself declared, a “chaos of illegibility” (Works 1: xxxiv). The poetry manuscripts do not readily welcome the editor. In addition to the geographical and paleographical challenges, EBB's corpus was huge, including the ballad, verse novel, narrative, dramatic lyric, sonnet and sonnet sequence, translation, hymn, dream vision, lyrical drama, ode, tribute poem, and elegy. Finally, much of the information about her poetry comes from the ongoing Brownings’ Correspondence, which includes letters both sent and received, and is currently at volume 18 (up to March 1853) out of a projected 40. There is a wealth of material by the Brownings, and not all of it readily accessible. Editing the works of EBB is a daunting prospect.
Foreign Land Holdings in Iran 1828 to 1911
Authors: MARTIN VANESSA , NOURAEI MORTEZA
Published: May 2011

The issue of the purchase of land in one country, in this case Iran, by other countries, in this case Britain and Russia, is one of great significance because of light it may throw on the strength or weakness of national sovereignty, and the ways and degree to which it may be undermined. It can also show the strategies deployed by the country challenged to protect its territorial integrity, as here in the case of Iran. The intricacies of foreign landownership patterns thus have implications for international relations, on which they can provide telling detail in terms of contemporary power politics. The details of land purchase also demonstrate considerable differences as between the two outside powers involved in terms of their objectives in Iran, and thus challenge a tendency in the literature to see them as similar.
TRANSCRITICAL FLOW PAST AN OBSTACLE
Authors: GRIMSHAW R.
Published: May 2011

It is well known that transcritical flow past an obstacle may generate undular bores propagating away from the obstacle. This flow has been successfully modelled in the framework of the forced Korteweg–de Vries equation, where numerical simulations and asymptotic analyses have shown that the unsteady undular bores are connected by a locally steady solution over the obstacle. In this paper we present an overview of the underlying theory, together with some recent work on the case where the obstacle has a large width.
Pension costs and liabilities for UK-regulated utilities
Authors: HUGHES GORDON
Published: May 2011

This paper argues that a substantial portion of the risks associated with the defined benefit (DB) pension schemes operated by regulated utilities in the UK will, in practice, fall on customers via the tariffs that they pay for regulated goods and services. It examines the assumptions made by regulated companies in their FRS 17 valuations. These assumptions generate parameters that systematically understate both the present value of pension liabilities and current service costs. These are re-estimated using the risk-free real rate of discount and compatible assumptions. On this basis, the total pension deficit for the sample increased from £12.7 billion to £56.3 billion in 2009, equivalent to about 110% of regulated revenues. Further, the cost of current service for 2008–09 was 20% higher than total contributions in the year, despite large top-up contributions. If contributions were increased to cover current service costs and to eliminate pension deficits over a period of 10 years, the additional contributions would amount to 235% of actual contributions or 13% of regulated revenues implying a significant increase in regulated charges. Companies in the communications and transport sectors face the largest adjustments in addressing the problems of underfunded pension schemes.
Multilayer porous waveguide for microwave low-loss applications
Authors: Mortazy Ebrahim , Hassani Alireza , Legare Francois , Wu Ke , Chaker Mohamed
Published: May 2011

A novel waveguide called multilayer porous waveguide (MPW) is proposed as microwave low-loss transmission lines. MPW is a fully rectangular dielectric waveguide composed of several periodically rectangular air gaps in a bulk dielectric that can be easily formed by placing several dielectric substrates in interval with air gaps. The loss and propagating characteristics of both TE and TM modes in MPW are studied. The TE mode confined in the air gaps has a lower loss than the TM mode spread out in air gaps and dielectric; however, the loss of TM mode is still less than that of conventional microwave waveguides. Finally, MPW is an artificial material with desirable electrical permittivity and loss that can be used in structure of conventional waveguides.
Limitations of laser diffraction for measuring fine particles in oligotrophic systems: Pitfalls and potential solutions
Authors: Andrews S. W. , Nover D. M. , Reuter J. E. , Schladow S. G.
Published: May 2011

Sampling of suspended particulates in oligotrophic environments is inherently difficult because of low ambient concentrations. The performance of a Laser In Situ Scattering and Transmissometry (LISST) series particle size analyzer is evaluated for use in such low‐concentration environments. Five issues are studied for their effect on recorded particle size distributions: the instrument limits of detection, the kernel matrix used in the inversion of the scattered light distribution, the effect of particles sized outside the instrument inversion limits (1.25 μm–250 μm), the effect of ambient light conditions, and the effect of sampling in density stratified conditions. We evaluate a LISST‐100X type B instrument using a series of small‐scale lab experiments and concentrate mainly on fine particles (<20 μm). Kernel matrix processing effects are shown to have large impacts on fine particle measurements, but accurate results can be obtained with the correct matrix choice. Concentration detection limits may be sufficient for the clearest fresh water environments but may be too high for accurate sampling in the oligotrophic open ocean. Large out of range particles (>250 μm) show little effects on the size distribution, but small particles (<1.25 μm) have large impacts. High ambient light conditions, typical in clear oligotrophic systems, create erroneously high concentrations of fine particles, and profiling in density stratified conditions is found to create incorrectly low concentrations. We present recommendations for the next generation of in situ laser diffractometers and advise consideration of the issues covered here before using current instruments in oligotrophic environments.
Visualizing classification of natural video sequences using sparse, hierarchical models of cortex.
Authors: Brumby Steven , Ham Michael , Landecker Will , Kenyon Garrett , Bettencourt Luís
Published: May 2011

Recent work on hierarchical models of visual cortex has reported state-of-the-art accuracy on whole-scene labeling using natural still imagery. This raises the question of whether the reported accuracy may be due to the sophisticated, non-biological back-end supervised classifiers typically used (support vector machines) and/or the limited number of images used in these experiments. In particular, is *the model classifying features from the object or the background? Previous work (Landecker, Brumby, et al., COSYNE 2010) proposed tracing the spatial support *of a classifier’s decision back through a hierarchical cortical model to determine which parts of the image contributed to the classification, compared to the positions of objects in the scene. In this way, we can go beyond standard measures of accuracy to provide tools for visualizing and analyzing high-level object classification. We now describe new work exploring the extension of these ideas to detection of objects in video sequences of natural scenes.
Estimation of oxidative status in lymphocytes of type2 diabetes mellitus patients
Authors: Arya Awadhesh K , Tripathi Kamlakar
Published: May 2011

Introduction: Diabetes mellitus (DM) is a group of metabolic disorders which opens the door for many diseases leading to various complications like neuropathy, nephropathy and retinopathy. Type 2 diabetes mellitus (T2DM) is associated with elevated level of oxidative stress, which is one of the most important factors responsible for the development of chronic complications of this disease. Antioxidants like reduced glutathione (GSH), superoxide dismutase (SOD) and catalase protects cells against oxidative damage.

Purpose:

Our present study suggests that hyperglycemia induced oxidative stress leads to various complications in T2DM patients. Here we investigated oxidative stress markers in lymphocytes of healthy control and diabetes mellitus patients.

Methods:

In the present study, 40 patients with T2DM (group A), aged 35-65 years and 30 healthy individuals (group B) of the same age group were included. Lymphocytes were isolated by using ficoll hypaque from heparinised blood obtained from all the participants in this study. Lymphocyte SOD, Catalase, Glutathione and MDA were estimated by using an ELISA reader.

Results:

SOD activity was higher in group B (98.97 ± 8.01) as compared with group A (49.71 ± 5.85);whereas catalase (61.50 ± 8.79 vs 76.33 ± 6.80) and glutathione (44.22 ± 6.85 vs 63.61 ± 8.89) amount was reduced in the same group as compared with healthy control. Lipid peroxidation was higher in group B (13.43 ± 3.99) as compared with healthy control (9.89 ± 2.59).

Conclusions:

Hyperglycemia induces the oxidative stress condition inside the lymphocytes which stimulates cell death for various cells including lymphocytes. Our data collectively confirm a significant decrease in lymphocyte GSH and catalase activity as well as an increase in activity of SOD and MDA reflecting elevated oxidative stress in the diabetic state.
Toll-like receptor 2 and 4 stimulation elicits an enhanced inflammatory response in human obese patients with atherosclerosis
Authors: Scholtes Vincent P.W. , Versteeg Dik , de Vries Jean-Paul P.M. , Hoefer Imo E. , Schoneveld Arjan H. , Stella Pieter R. , Doevendans Pieter A.F.M. , van Keulen Karlijn J.K. , de Kleijn Dominique P.V. , Moll Frans L. , Pasterkamp Gerard
Published: May 2011

The innate immune response elicited by activation of TLRs (Toll-like receptors) plays an important role in the pathogenesis of atherosclerosis. We hypothesized that cardiovascular risk factors are associated with the activation status of the innate immune system. We therefore assessed the responsiveness of TLRs on circulating cells in two groups of patients with established atherosclerosis and related this to the presence of cardiovascular risk factors. TNF (tumour necrosis factor)-α release induced by TLR2 and TLR4 activation was measured in patients with established coronary [PCI (percutaneous coronary intervention) study, n=78] or carotid artery disease [CEA (carotid endarterectomy) study, n=104], by stimulating whole blood samples with lipopolysaccharide (TLR4 ligand) and Pam3CSK4 [tripalmitoylcysteinylseryl-(lysyl)4; TLR2 ligand]. As an early activation marker, CD11b expression was measured by flow cytometry on CD14+ cells. Obesity was the ‘only’ risk factor that correlated with the TLR response. In both studies, obese patients had significantly higher TNF-α levels after stimulation of TLR2 compared with non-obese patients [16.9 (7.7–49.4) compared with 7.5 (1.5–19.2) pg/ml (P=0.008) in coronary artery disease and 14.6 (8.1–28.4) compared with 9.5 (6.1–15.7) pg/ml (P=0.015) in carotid artery disease; values are medians (interquartile range)]. Similar results were obtained following TLR4 stimulation. The enhanced inflammatory state in obese patients was also confirmed by a significant increased expression of the activation marker CD11b on circulating monocytes. In conclusion, obesity is associated with an enhanced TLR response in patients suffering from established atherosclerotic disease.
Axis-switching of non-axisymmetric microdroplet ejected from inkjet with an elliptical nozzle
Authors: Kwon Dae Hee , Lee Sang Joon
Published: May 2011

Dynamic behaviors of the microdroplet ejected from the inkjet printhead with an elliptical nozzle are investigated using a high-speed micro-imaging system. The elliptic geometry of the nozzle induces elliptical cross section of the ejected droplet and the periodic switching of its major and minor axes. From the temporally resolved measurement of droplet configuration based on the reproducibility of drop formation, the frequency responses and the viscous damping rates of the droplet oscillations are analyzed. The discrepancies in the dominant frequency and the decaying time constant between the axis-switching and axial oscillations are maintained in the measurement section, despite the effects of the nonlinearity and mode coupling.
Laboratory experiments on two coalescing axisymmetric turbulent plumes in a rotating fluid
Authors: Yamamoto H. , Cenedese C. , Caulfield C. P.
Published: May 2011

We investigate the early-time coalescence of two co-flowing axisymmetric turbulent plumes and the later-time flow of the induced vortices in a rotating, homogeneous fluid using laboratory experiments. The experiments demonstrate the critical importance of the rotation period Tf=2π/f, where f is the Coriolis parameter of the background rotation. We find that if the plumes’ sources are sufficiently “close” for the plumes to merge initially at an “early time” tm≲tr=3Tf/4, the experimentally observed merging height zme agrees well with the non-rotating theoretical relationship of zmt≈(0.44/α)x0<zr=5.5F01/4f-3/4, where α is the entrainment “constant” of the turbulent plumes, x0 is the separation distance between the two plume sources, F0 is the source buoyancy flux of each plume, and zr is the distance that the plume rises in the time tr before rotational effects become significant. Therefore, rotation does not affect the initial time to merger or the initial merger height of such “close” plumes. For “late” times t>tr, however, the flow dynamics are substantially more complicated, as the flow becomes significantly affected by rotation. The propagation and entrainment of the plumes becomes strongly affected by the vortices induced by the entrainment flow in a rotating environment. Also, the plume fluid itself starts to interact with these vortices. If the plumes have already initially merged by the time t=tr, a single vortex (initially located at the midpoint of the line connecting the two plume sources) develops, which both advects and modifies the geometry of the merging plumes. Coupled with the various suppressing effects of rotation on the radial plume entrainment, the “apparent” observed height of merger can vary substantially from its initial value. Conversely, for more widely separated “distant” plumes, where x0>xc=(25α/2)F01/4f-3/4, the plumes do not merge before the critical time tr when rotation becomes significant in the flow dynamics and two vortices are observed, each located over a plume source. The combined effect of these vortices with the associated suppression of entrainment by rotation thus significantly further delays the merger of the two plumes, which apparently becomes possible only through the merger of the induced vortices.
Cell chip array for microfluidic proteomics enabling rapid in situ assessment of intracellular protein phosphorylation
Authors: Faley Shannon L. , Copland Mhairi , Reboud Julien , Cooper Jonathan M.
Published: May 2011

We discuss the ability to perform fluorescent immunocytochemistry, following cell fixation, using a microfluidic array of primary, nonadherent, single CD34+ stem cells. The technique requires small cell samples and proceeds with no cell loss, making it well-suited to monitoring these rare patient-derived cells. The chip allows us to correlate live cell dynamics across arrays of individual cells with post-translational modifications of intracellular proteins, following their exposure to drug treatments. Results also show that due to the microfluidic environment, the time scale of cell fixation was significantly reduced compared to conventional methods, leading to greater confidence in the status of the protein modifications studied.
Smoothing of surface of silica glass by heat treatment in wet atmosphere
Authors: Osawa Kenta , Inoue Hiroyuki , Masuno Atsunobu , Katayama Keiichi , Zhang Yingjiu , Utsuno Futoshi , Sugahara Yoshiyuki , Koya Kazuo , Fujinoki Akira , Tawarayama Hiromasa , Kawazoe Hiroshi
Published: May 2011

The effect of heat treatment on the surface morphology of fused silica glass substrates was investigated. It was found that the water vapor pressure during heat treatment had a strong influence on the flattening of the silica glass surface. The surface of the frosted glass changed into a transparent and lustrous surface after heat treatment with water vapor at 1200 °C for 48 h, whereas surface irregularities remained for heat treatment under a dry atmosphere. It was suggested that the difference in surface flattening was caused by changes in surface viscosity that depended on the concentration of OH groups on the surface. In order to quantitatively understand the effect of the heat treatment atmosphere, power spectral density (PSD) analysis and a novel peak and valley method were applied to the experimental results. From the PSD analysis, it was found that the Mullins’ model could not explain the smoothing behavior by heat treatment. The peak and valley method, which could separate the surface morphology into the surface irregularities and the background undulation, revealed that the Mullins’ model limitation was mainly for the surface and the background undulation could be understood within the model. These results indicate that there are different mechanisms between for the surface smoothing and for the relaxation of the background undulation.
Analytical approach to modulation properties of quantum dot lasers
Authors: Lüdge Kathy , Schöll Eckehard , Viktorov Evgeny , Erneux Thomas
Published: May 2011

We analyze a microscopically based rate equation model for quantum dot lasers. The model separately treats the dynamics of electrons and holes, and the carrier-carrier scattering rates depend nonlinearly on the wetting layer carrier densities. Our objective is to determine analytical expressions for the relaxation oscillation frequency and damping rate. To this end, we consider the Class B limit of the five rate equations and apply asymptotic techniques. We consider two cases corresponding to either equivalent or drastically different decay rates for the electrons and holes. We show how they contribute to increase the relaxation oscillation damping rate compared to the damping rate of the conventional laser and that there exist optimal conditions on the control parameters in order to observe maximum damping.