bluuebunny/crossref_metadata_2025 huggingface dataset:
Evidence of basolateral water permeability regulation in amphibian urinary bladder
Authors: Candia Oscar A , Mia Abdul , Yorio Thomas
Published: February 2012

It is well known that arginine vasopressin (AVP) produces up to a 40‐fold increase (0.1 to 4,0 μL/min·cm2) in net water flux across the amphibian urinary bladder under an osmotic gradient (mucosal side 10% hypotonic). No AVP effect is observed when the gradient is in the opposite direction (serosal hypotonic). Similar asymmetrical behavior to osmotic gradients occurs in the frog corneal epithelium. This rectification phenomenon has not been satisfactorily explained. We measured net water fluxes in bladder sacs and confirmed that AVP has no effect when the serosal bath is hypotonic. We reasoned that the ‘abnormal’ serosal osmolarity was inducing changes in membrane water permeability, the very parameter being measured. Thus, we studied the effect of solution osmolarity on diffusional water flow (Jdw) across the frog bladder using 3H2O. As expected, AVP doubled Jdw (in either direction from 12 to 21 μL/min·cm2) when the serosal solution was iso‐osmolar regardless of mucosal osmolarity. However, in the AVP‐stimulated bladders, hypo‐osmolarity of the serosal solution reduced Jdw by 42%, an effect that was reversible when normal osmolarity was re‐established. Amphotericin B (instead of AVP) was used to irreversibly increase the permeability to water of the apical membrane. Under these conditions, basolateral hypotonicity also reversibly decreased Jdw by 32%, suggesting the basolateral membrane as the site where permeability is reduced. SEM and TEM of the tissue shows extreme swelling when it was exposed to serosal hypotonicity with or without AVP and typical surface morphology changes following hormone stimulation. We conclude that this swelling may initiate a signaling mechanism that reduces basolateral water permeability. These findings constitute evidence of basolateral water channel permeability regulation, which can also contribute to cell volume regulation.
Influence of genistein (4′,5,7‐trihydroxyisoflavone) on the growth and proliferation of testicular cell lines
Authors: Kumi‐Diaka James , Rodriguez Rosanna , Goudaze Gould
Published: February 2012

The effects of genistein on testicular cells, TM3, TM4, and GC‐1 spg, were studied in vitro. First, each cell line was cultured with pre‐determined concentrations of genistein for a maximum of 72 h to assess the effects of genistein on in vitro growth of the test cells. A second series of experiments were performed to determine the degree of genistein‐induced apoptosis in these cells, using Apop‐TagR kit reagents, to detect apoptotic cells in situ by specific end labeling, and detection of DNA fragments produced by the apoptotic process. The results obtained indicate that: i) genistein inhibits the growth and proliferation of testicular cells; ii) growth inhibition and proliferation is dose‐ and exposure‐time dependent; iii) there is significant difference in sensitivity of the different testicular cells to genistein; iv) genistein induces apoptosis in testicular cells in a concentration‐dependent manner. Genistein‐induced apoptosis identifies genistein as a potential diagnostic and therapeutic tool in testicular pathophysiological research.
Control of vascular endothelial growth factor angiogenic activity by the extracellular matrix
Authors: Ortéga Nathalie , L'Faqihi Fatima‐Ezzahra , Plouët Jean
Published: February 2012

In adult vessels the proliferation rate of differentiated endothelial cells is very low. In response to several environmental stimuli the expression of so‐called ‘angiogenic factors’ is upregulated and the messenger RNAs are actively translated in secreted factors which induce the proliferation of endothelial cells; the digestion of their basement membrane then allows their migration and differentiation. Considerable progress has been made during the past years in elucidating the molecular actors of angiogenesis. Vascular endothelial growth factor turned out to represent the major inducer of angiogenesis. Optional splicing of its pre‐messenger RNA generates various isoforms which differ not only by their storage in the extracellular matrix but also by their signaling pathways.
Maturation promoting factor activation in early amphibian embryos: Temporal and spatial control
Authors: Beckhelling Clare , Ford Chris
Published: February 2012

The cytoplasmic localisation of factors capable of influencing the behaviour of nuclei has long been considered a potential mechanism for generating cell differences during development. Yoshio Masui was instrumental in identifying two cytoplasmic factors, maturation promoting factor (MPF) and cytostatic factor (CSF), defining the first biological assay for their isolation and characterisation. These biological assays involved the transfer of cytoplasm between amphibian oocytes, MPF being able to promote meiotic maturation (progression to MII) and CSF to stabilise the MII state. Masui was subsequently involved in developing a ‘cell‐free’ system with the potential for analysis not just of MPF and CSF, but many aspects of nucleo‐cytoplasmic interaction. Masui and Markert initially showed that MPF activity could be generated in enucleate oocytes following progesterone stimulation, indicating a cytoplasmic origin. Masui subsequently showed that MPF activity was distributed unevenly through the egg of Rana pipiens during maturation. In this review we will consider the historical context in which the MPF assays were established, then briefly consider some of the molecular components that are now known to influence MPF activation. We will then consider evidence for the asymmetric activation of MPF and the possibility that the nucleus contributes to MPF activation in early embryos.
Germinal vesicle material is dispensable for oscillations in cdc2 and MAP kinase activities, cyclin B degradation and synthesis during meiosis in Xenopus oocytes
Authors: Fisher Daniel , Coux Olivier , Bompard‐Maréchal Guillaume , Dorée Marcel
Published: February 2012

We have investigated at a molecular level the requirements for germinal vesicle (nuclear) material during the course of meiosis in Xenopus oocytes. We present the localization of some cell cycle proteins in stage VI oocytes; most of those analyzed are cytoplasmic, although some (MAD, 26S proteasome) are distributed between the cytoplasm and the germinal vesicle. By analyzing changes in individual oocytes, we find that the unphosphorylated form of cyclin B2 disappears and the phosphorylated form is then degraded in both nucleated and enucleated oocytes. Enucleated oocytes are also capable of resynthesizing both cyclin B1 and cyclin B2 after the initial degradation and of reactivating cdc2 kinase. Synthesis of mos protein and activation of MAP kinase concomitant with cdc2‐cyclin B reactivation are also unaffected by prior removal of the germinal vesicle.
Cytoplasmic factors that control nuclear behavior in mammalian oocytes: A re‐evaluation of studies performed as a student of Yoshio Masui
Authors: Clarke Hugh J
Published: February 2012

Studies performed by the author in the laboratory of Dr Yoshio Masui are reviewed and interpreted in the light of subsequent findings. The first series of studies indicated that that chromosome condensation during meiotic maturation of mouse oocytes is controlled initially by a stable protein that decays during maturation and subsequently by an unstable protein synthesized after germinal vesicle breakdown. Cyclin B is present in immature oocytes, becomes partially degraded near metaphase I and then re‐accumulates, suggesting that this may be protein whose activity was inferred from the original results. The second series of experiments indicated that factors which appear in the oocyte cytoplasm during maturation are able to remodel the sperm into metaphase‐like chromosomes, and that the supply of these factors is limited. Recent work indicates that these factors are required for the assembly of histones onto the sperm DNA, and has identified two molecular species, mNAP‐1 and NPM‐3, known to promote replication‐independent chromatin assembly in somatic cells, that are expressed in oocytes.
Ras family proteins: New players involved in the diplotene arrest of Xenopus oocytes
Authors: Jessus Catherine , Rime Hélène , Ozon René
Published: February 2012

Oogonia undergo numerous mitotic cell cycles before completing the last DNA replication and entering the meiotic prophase I. After chromosome pairing and chromatid exchanges between paired chromosomes, the oocyte I remains arrested at the diplotene stage of the first meiotic prophase. Oocyte growth then occurs independently of cell division; indeed, during this growth period, oocytes (4n DNA) are prevented from completing the meiotic divisions. How is the prophase arrest regulated? One of the players of the prophase block is the high level of intracellular cAMP, maintained by an active adenylate cyclase. By using lethal toxin from Clostridium sordellii (LT), a glucosyl‐transferase that glucosylates and inactivates small G proteins of the Ras subfamily, we have shown that inhibition of either Ras or Rap or both proteins is sufficient to release the prophase block of Xenopus oocytes in a cAMP‐dependent manner. The implications of Ras family proteins as new players involved in the prophase arrest of Xenopus oocytes will be discussed here.
The complete sequence and expression patterns of the atrial myosin heavy chain in the developing chick*
Authors: Oana Shinji , Machida Shuichi , Hiratsuka Eriko , Furutani Yoshiyuki , Momma Kazuo , Takao Atsuyoshi , Matsuoka Rumiko
Published: February 2012

We have earlier reported partial cloning of a cDNA of a chick atrial myosin heavy chain (MHC) gene, CCSV2 and its expression pattern in embryonic chick hearts (Oana et al (1995) Eur J Cell Biol 67, 42–49). In this study, five overlapping cDNA clones (including CCSV2) which together encode the entire open reading frame of the chick atrial MHC gene were characterized, and both the entire nucleotide sequence consisting of 5825 bases and the deduced amino acid sequence consisting of 1931 amino acids determined. Reinvestigation of the nucleotide sequence of the previously reported and presumably different chick atrial specific MHC cDNA clone, AMHC1 (Yutzey et al (1994) Development 120, 871–883), revealed that our clone and AMHC1 encoded the same MHC. The chick atrial MHC gene was strongly expressed in developing chick atria from a very early stage (Hamburger and Hamilton stage 9, 29–33 h) to the adult stage. This gene was also expressed, although weakly, in the ventricle, somite (the precursor to skeletal muscle) and skeletal muscle during embryonic stages but not in adults.
The direct visualization of structural array from laminin to dystrophin in sarcolemmal vesicles prepared from rat skeletal muscles
Authors: Hijikata Takao , Fujimaki Noboru , Osawa Hidenobu , Ishikawa Harunori
Published: February 2012

It has been biochemically shown that dystrophin and α‐ and β‐dystroglycan form an oligomeric complex which links laminin, a component of the basement membrane, to components of the subsarcolemmal cytoskeleton in skeletal muscle fibers. In the present study the dystrophin‐glycoprotein complex and its structural relationships to laminin and subsarcolemmal cytoskeleton were ultrastructurally examined in crude surface membranes prepared from rat skeletal muscles. Sarcolemmal vesicles within crude surface membranes were identified and characterized by fine protrusions on their outer surface and electron‐dense materials or patches associated with the inner surface. These two components were seen to be in register with each other across the sarcolemma. The fine protrusions were immunolabeled by anti‐α‐dystroglycan and reassociated with exogenous laminin. Immunolabeling in combination with laminin reassociation demonstrated that the electron‐dense materials contained dystrophin at laminin‐binding domains of the membrane. In addition, they were often associated with very fine filaments. These results provide morphological evidence for the biochemically proposed model of molecular array of dystrophin complex from the basement membrane to the subsarcolemmal cytoskeleton.
A fluorescence dequenching method for monitoring exocytotic membrane fusion in fertilization of single sea urchin eggs
Authors: Takemoto Kazuhisa , Hirano Ken‐ichi , Hayakawa Tsuyoshi , Kuroda Ritsu , Kuroda Hideyo
Published: February 2012

A method for monitoring exocytotic membrane fusion by using a fluorescent membrane probe is presented. The method is based on the relief from concentration‐dependent self‐quenching (dequenching) of fluorescence of 5‐N‐(octadecanoyl)aminofluorescein (AF18), an amphiphilic derivative of fluorescein. The validity and usefulness of this method were shown by the following results: 1) self‐quenching of AF18 fluorescence occurred in the plasma membrane of unfertilized eggs of a sea urchin, Pseudocentrotus depressus, which were heavily stained with the fluorescent dye; 2) dequenching of AF18 fluorescence occurred upon fertilization in normal eggs but not in EGTA‐injected eggs; 3) Ca2+ induced both AF18 fluorescence dequenching and cortical granule disappearance in the isolated sea urchin egg cortex; and 4) simultaneous measurements of the intracellular Ca2+ concentration ([Ca2+]i) and dequenching of AF18 fluorescence by using a simple one‐excitation and two‐emission wavelength system.
Organisation of complex nuclear domains in somatic mouse cells
Authors: Cerda María Cristina , Berríos Soledad , Fernández‐Donoso Raúl , Garagna Silvia , Redi Carlo
Published: February 2012

The number and associations of heterochromatin chromocenters, nucleoli, centromeres and telomeres were studied in the nucleus of different somatic cells of Mus domesticus. Fibroblasts of the cell line 3T3, kidney cells (primary culture), and bone marrow cells were used. The above mentioned nuclear and chromosome markers were identified by DAPI/actinomycin D, indirect immunofluorescence with anti‐centromere antibodies, silver impregnation for nucleolar proteins and fluorescence in situ hybridisation (FISH) with telomeric probes. The quantitative analysis of the nuclei showed that the pericentromeric heterochromatin is organised in about 18 chromocenters per nucleus in the 3T3 cells, and about seven in kidney and bone marrow cells, having generally a peripheral distribution in the nucleus of all the studied cells. Several aggregated centromeres were participating in each of the chromocenters, about four centromeres per 3T3 cell and about six centromeres per kidney and bone marrow cells. Some of the chromocenters were also in close association with nucleoli. The number of telomeric labels per nucleus was as expected for each chromosome set (2n = 68–70 and 2n = 40). About half of the telomeric signals were loosely aggregated within the heterochromatic blocks while the rest were distributed in the nucleus as unrelated units not bound with chromocenters. The three cell types have complex nuclear territories formed by different chromosomal domains: the pericentromeric heterochromatin, centromeres, proximal telomeres and nucleoli. With the exception of some bone marrow cells, we have not found a nuclear polarisation of the analysed chromosomal markers compatible with the Rabl configuration. However, Rabl anaphasic polarisation allows the contact of centromeric regions making possible that centromeric associations arise. If in addition, associative elements such as constitutive heterochromatin or nucleoli are close to the centromeric regions, like in Mus domesticus chromosomes, then the associations might be consolidated and persist until the interphase. These associations may be the origin of the nuclear domains described here for Mus domesticus somatic cells.
Life cycles of yeast spindle pole bodies: Getting microtubules into a closed nucleus
Authors: McIntosh J Richard , O'Toole Eileen T
Published: February 2012

The spindle pole body (SPB) is the principal microtubule organizing center of budding and fission yeast. We have examined SPBs and their associated microtubules from both organisms, using electron microscopy and three‐dimensional reconstruction techniques, to identify the structural changes that accompany progression through the cell cycle. In this report, we compare these changes in the two kinds of yeasts and present a model for how microtubules get into a closed nucleus.
Polarities of the centriolar structure: Morphogenetic consequences
Authors: Beisson Janine , Jerka‐Dziadosz Maria
Published: February 2012

Centrioles and basal bodies are two versions of the same conserved eukaryotic organelle and share two remarkable properties: nine‐fold symmetry of their microtubular shaft and capacity to generate a new organelle in a fixed geometrical relationship to the mother organelle. It can thus be postulated that what is true for basal bodies is likely to be true also for centrioles. While the functions of centrioles are difficult to dissect, the functions of basal bodies are easier to approach. Over more than two decades, studies on protists have led to the notion that ciliary and flagellar basal bodies display polarities, not only a proximo‐distal polarity, like in centrioles, but also a circumferential polarity accorded to the polarities of the cell and of its cytoskeleton. The major cytological and genetical data, mainly on Chlamydomonas, Paramecium and Tetrahymena, which support the notion that the microtubule triplets of basal bodies are non‐equivalent, are reviewed. The morphogenetic implications of this circumferential anisotropy, perpetuated through the process of basal body duplication itself, are discussed. The question is raised of the possibility that centrioles also display a circumferential polarity, like basal bodies, and whether at least certain of their functions depend on such asymmetries.
Cell cycle‐dependent localization of monoclonal antibodies raised against isolated Dictyostelium centrosomes
Authors: Gräf Ralph , Daunderer Christine , Schliwa Manfred
Published: February 2012

The ultrastructure of the Dictyostelium centrosome is markedly different from that of the well known yeast spindle pole body and vertebrate centriole‐containing centrosome. It consists of a box‐shaped, layered core structure surrounded by a corona with dense nodules embedded in an amorphous matrix. For further structural and biochemical analyses of this type of centrosome we used highly enriched isolated Dictyostelium centrosomes as an antigen to raise 14 new centrosomal monoclonal antibodies. Immunofluorescence microscopy and Western blot analysis revealed that at least 10 of them were directed against different antigens. Immunofluorescence microscopy also showed that the monoclonal antibodies fell into three different groups: A) antibodies localizing to the centrosome during the entire cell cycle; B) antibodies staining the centrosome mainly during mitosis; and C) antibodies labeling centrosome associated structures. All antibodies, except one, exhibited a cell cycle‐dependent staining pattern underscoring the highly dynamic properties of the Dictyostelium centrosome.
A transient decrease of electrochemical gradient stabilizes DNA structural change in single mitochondria of living cells
Authors: Durieux Christiane , Brunet Anne‐Christine , Geeraert Virginie , Coppey Jacques , Coppey‐Moisan Maïte
Published: February 2012

The effect of controlled and reversible perturbation of the electrochemical gradient on the structural changes of mitochondrial DNA has been studied in living cells by fluorescence microscopy. Electrochemical gradient perturbations were induced by the protonophore carbonyl cyanide p‐trifluoromethoxyphenylhydrazone and quantified by measuring the mitochondrial membrane potential using tetramethyl rhodamine methyl ester. Under our experimental conditions, we have shown that ethidium fluorescence was mainly due to ethidium molecules intercalated in mtDNA. Ethidium fluorescence variations have been used to probe DNA structural changes. This showed that: i) electrochemical gradient perturbations induced mtDNA structural change; ii) this change was readily reversible following a total but short collapse of the electrochemical gradient; iii) in contrast, a short and weak perturbation of the electrochemical gradient stabilized the mtDNA structural change; and iv) the degree of weak depolarization varied from cell to cell, showing the necessity of studying the effect of energetic perturbations at the level of an individual cell.
Seasonal variation of xanthine oxidoreductase activity in the digestive gland cells of the mussel Mytilus galloprovincialis: A biochemical, histochemical and immunochemical study
Authors: Cancio Ibon , Cajaraville Miren P
Published: February 2012

The activity and the tissue distribution of the oxygen radical producing enzyme xanthine oxidoreductase (XOR) were measured in the digestive gland of the common marine mussel Mytilus galloprovincialis Lmk along an annual cycle. No xanthine oxidase (XOX) activity could be measured, the enzyme only displaying xanthine dehydrogenase (XDH) activity in all the cases. This is interpreted as a mechanism to avoid the harmful effects of the oxygen radicals that would be produced by XOX during periods following anoxic conditions at low tide. The highest XDH activities coincided with the late spring/early summer months, the activity maxima being recorded from May to July. Histochemically XOR activity was very pronounced in duct and stomach epithelial cells as well as in the surrounding connective tissue and hemolymph vessels, the activity increasing towards the summer months. These seasonal variations in XDH or XOR activities are possibly linked to hormonal changes governing the reproductive cycle and to changes in food availability. The localization of the protein in the connective tissue lining the hemolymph vessels was confirmed immunohistochemically using a polyclonal antibody against rat liver protein that cross‐reacted specifically with a polypeptide of 150 kDa of molecular mass in homogenates of the digestive gland. This polypeptide was linked to cytosolic fractions isolated by differential centrifugation from mussel digestive glands. In paraffin sections the antibody labeled the digestive cells of digestive tubules, as well as the connective tissue surrounding the hemolymph vessels, gonadal follicles, digestive epithelia and certain protozoan parasites. Taken together our results suggest that in the digestive gland of bivalve molluscs XOR is involved in the metabolism of purines and in the scavenging of oxygen free radicals.
Deletion of the fiber gene induces the storage of hexon and penton base proteins in PML/Sp100‐containing inclusions during adenovirus infection
Authors: Puvion‐Dutilleul Francine , Legrand Valérie , Mehtali Majid , Chelbi‐Alix Mounira K , de Thé Hugues , Puvion Edmond
Published: February 2012

The present study has documented changes in the in situ distribution of viral DNA and capsid proteins in 293 cells infected with fiber gene‐deleted adenoviruses. It shows that infection results in the intense production of progeny viruses which appear morphologically intact although they are devoid of fiber‐coding sequence in their genome and hence of fiber protein in their capsid. The data confirm, therefore, that fiber protein is not essential for the assembly of progeny viruses. The main contribution of our observations concerns specific intranuclear structures induced by infection with either wild‐type or fiber gene‐deleted viruses. These clear amorphous inclusions contain two cellular proteins, PML and Sp100, which in non‐infected cells co‐localize to a special type of nuclear bodies. PML and Sp100 nuclear bodies appear to directly modulate or to be altered in a wide variety of situations including viral infections, cell death and transformation. In cells infected with fiber gene‐deleted viruses, the clear amorphous inclusions now accumulate non‐used hexon and penton base proteins, whereas the absence of fiber protein prevents the assembly of capsid proteins in crystallin arrays. Taken together, the data suggest that the clear amorphous inclusions may correspond to storage sites of structural and regulatory proteins. Consequently, these virus‐induced structures may promote the productive cycle of adenoviruses by regulating the amount of over‐produced viral proteins and the shutoff of the host cell metabolism.
p53‐independent regulation of cyclin B1 in normal human fibroblasts during UV‐induced G2‐arrest
Authors: Vincent Florence , Deplanque Gaël , Ceraline Jocelyn , Duclos Brigitte , Bergerat Jean‐Pierre
Published: February 2012

Recently we demonstrated, using normal human fibroblasts (NHFs), that UVc radiation induces G2/M arrest which was even more pronounced when p53 expression was inhibited. So, the aim of this study was to evaluate in NHFs the relationship between UV‐inducedG2/M arrest and cyclin B1 regulation and to investigate if p53 could contribute to the cyclin B1 regulation in these conditions. Following exposure of asynchronous NHFs to UV light, we showed that the induced G2/M arrest was accompanied by a dose‐dependent down‐regulation of cyclin B1 mRNA as evaluated by RT‐PCR. Concomitantly, using flow cytometric analysis, we observed a strong accumulation of cyclin B1 protein which was correlated to the apparition of the G2/M arrest. In order to study the contribution of p53 to the cyclin B1 accumulation in response to UV exposure, we inhibited p53 induction using p53 antisense oligonucleotides. We found that the inhibition of p53 protein induction after UV exposure had no effect on the level of cyclin B1 mRNA. Moreover, although inhibition of p53 protein induction increased the number of the cells in the G2‐M phase, the mean content of cyclin B1 protein was not augmented in these cells. These results indicate clearly that the induction of p53 protein following UV exposure does not regulate the level of cyclin B1 mRNA or protein in normal cells.
Composition and organization of tubulin isoforms reveals a variety of axonemal models
Authors: Péchart Isabelle , Kann Marie‐Louise , Levilliers Nicolette , Bre Marie‐Hélène , Fouquet Jean‐Pierre
Published: February 2012

In the flagellum of mammalian spermatozoa, glutamylated and glycylated tubulin isoforms are detected according to longitudinal gradients and preferentially in axonemal doublets 1–5–6 and 3–8, respectively. This suggested a role for these tubulin isoforms in the regulation of flagellar beating. In the present work, using antibodies directed against various tubulin isoforms and quantitative immunogold analysis, we aimed at investigating whether the particular accessibility of tubulin isoforms in the mammalian sperm flagellum is restricted to this model of axoneme surrounded with periaxonemal structures or is also displayed in naked axonemes. In rodent lung ciliated cells, all studied tubulin isoforms are uniformly distributed in all axonemal microtubules with a unique deficiency of glutamylated tubulin in the transitional region. A similar distribution of tubulin isoforms is observed in cilia of Paramecium, except for a decreasing gradient of glutamylated tubulin labeling in the proximal part of axonemal microtubules. In the sea urchin sperm flagellum, predominant labeling of tyrosinated and detyrosinated tubulin in 1–5–6 and 3–8 doublets, respectively, were observed together with decreasing proximo‐distal gradients of glutamylated and polyglycylated tubulin labeling and an increasing gradient of monoglycylated tubulin labeling. In flagella of Chlamydomonas, the glutamylated and glycylated tubulin isoforms are detected at low levels. Our results show a specific composition and organization of tubulin isoforms in different models of cilia and flagella, suggesting various models of functional organization and beating regulation of the axoneme.
Precision of a photogrammetric method to perform 3D wound measurements compared to standard 2D photographic techniques in the horse
Authors: LABENS R. , BLIKSLAGER A.
Published: January 2012

Reasons for performing study: Methods of 3D wound imaging in man play an important role in monitoring of healing and determination of the prognosis. Standard photographic assessments in equine wound management consist of 2D analyses, which provide little quantitative information on the wound bed.

Hypotheses: 3D imaging of equine wounds is feasible using principles of stereophotogrammetry. 3D measurements differ significantly and are more precise than results with standard 2D assessments.

Methods: Repeated specialised photographic imaging of 4 clinical wounds left to heal by second intention was performed. The intraoperator variability in measurements due to imaging and 3D processing was compared to that of a standard 2D technique using descriptive statistics and multivariate repeated measures ANOVA.

Results: Using a custom made imaging system, 3D analyses were successfully performed. Area and circumference measurements were significantly different between imaging modalities. The intraoperator variability of 3D measurements was up to 2.8 times less than that of 2D results. On average, the maximum discrepancy between repeated measurements was 5.8% of the mean for 3D and 17.3% of the mean for 2D assessments.

Conclusions: The intraoperator repeatability of 3D wound measurements based on principles of stereophotogrammetry is significantly increased compared to that of a standard 2D photographic technique indicating it may be a useful diagnostic and monitoring tool.

Potential relevance: The equine granulation bed plays an important role in equine wound healing. When compared to 2D analyses 3D monitoring of the equine wound bed allows superior quantitative characterisation, contributing to clinical and experimental investigations by offering potential new parameters.
Pharmacy technicians' views of learning and practice implementation
Authors: Schafheutle Ellen I , Smith Clar , Cutts Christophe , Higginson Paula J , Noyce Peter R
Published: February 2012

Objective

Registered pharmacy technicians are a new group of regulated healthcare professionals in Great Britain, who fall under the same requirements for undertaking and recording of continuing professional development (CPD) as pharmacists. Little is known about this group of pharmacy professionals, their understanding of CPD and learning, or how they implement their learning into practice. This study aimed to address this.

Methods

A questionnaire was developed and sent to all 216 attendees of an interactive continuing education workshop provided in 12 different geographical locations in England.

Key findings

Over a third (n = 146; 67.6%) responded. The majority (94.5%) were female, aged between 40 and 49 years (43.8%), and had qualified less than 10 years ago (49.4%). Most worked in community (56.2%) or hospital (19.9%) pharmacy. When asked about whether they had implemented any of the workshop learning into practice, 84.2% ticked at least one option from a predetermined list, and 83.6% provided detailed descriptions of a situation, what they did and its outcome. These were grouped into two themes: people and places. Places referred to comments made about changes to systems, operations or equipment within the workplace; people concerned changes within respondents themselves or others, such as staff or customers. More than two-thirds (70.3%) had used their learning to create a CPD record, and those who had not (n = 43) gave lack of time but also lack of understanding as reasons.

Conclusions

This study has provided detailed insights into pharmacy technicians' learning, reflection and practice implementation following an interactive workshop.
Simplified screening for overweight in children using the 2007 WHO Reference
Authors: Nainar S. M. H.
Published: February 2012

Objective

The aim of this study was to develop a screening instrument for easy identification of overweight in children and adolescents.

Methods

Data derived from the 2007 Growth Reference published by the World Health Organization (WHO) were utilized to compute gender‐specific screening values for identification of overweight in 5‐ to 19‐year‐olds. Computations were based on age‐ and gender‐specific +1 standard deviation z‐scores for the body mass index and calculated for the various height percentiles at 6‐month age intervals.

Results

The simplified approach for identification of overweight consisted of two tables, one each for girls and boys. Each table described the screening values for overweight at 6‐month age intervals for all the 11 height percentiles described in the 2007 WHO Reference.

Conclusion

The simplified approach uses only the child's height and weight measurements and without any additional computation provides an assessment of overweight status in children and adolescents.
Effects of Wind Turbine Starting Capability on Energy Yield
Authors: Worasinchai Supakit , Ingram Grant L. , Dominy Robert G.
Published: February 2012

The purpose of this study was to investigate the effect of turbine starting capability on overall energy-production capacity. The investigation was performed through the development and validation of matlab/Simulink models of turbines. A novel aspect of this paper is that the effects of load types, namely resistive heating, battery charging, and grid connection were also investigated. It was shown that major contributors to improved starting performance are aerodynamic improvements, reduction of inertia, and simply changing the pitch angle of the blades. The first two contributors can be attained from an exploitation of a “mixed-airfoil” blade.The results indicate that starting ability has a direct effect on the duration that the turbine can operate and consequently its overall energy output. The overall behavior of the wind turbine system depends on the load type, these impose different torque characteristics for the turbine to overcome and lead to different power production characteristics.When a “mixed-airfoil” blade is used the annual energy production of the wind systems increases with the exception of resistive heating loads. Net changes in annual energy production were range of −4% to 40% depending on the load types and sites considered. The significant improvement in energy production strongly suggests that both the starting performance and load types should be considered together in the design process.
An Experimental Study of Lean Blowout With Hydrogen-Enriched Fuels
Authors: Zhu Shengrong , Acharya Sumanta
Published: February 2012

Lean premixed combustion is widely used to achieve a better compromise between nitric oxide (NOx) emissions and combustion efficiency (related to CO levels). However, combustor operation near the lean blowout (LBO) limit can render the flame unstable and lead to oscillations, flashback, or extinction, thereby limiting the potential range of lean combustion application. Recent interest in integrated gasification combined cycle plants and syngas combustion requires an improved understanding of the role of hydrogen on the combustion process. Therefore, in the present study, combustion of pure methane and blended methane-hydrogen with hydrogen-levels up to 80% by volume has been conducted in a swirl stabilized premixed combustor. Particle imaging velocimetry (PIV) and OH* chemiluminescence imaging have been used in this study. Results show that there is a single-ringed structure of internal recirculation zone (IRZ) in the non-reacting flow, while in the reacting flows, there is a more complex flow pattern with a two-celled IRZ structure in which the axial velocity near the center-axis is oriented downstream. As the equivalence ratio decreases, the width of IRZ decreases in methane flames while it increases in hydrogen-enriched flames, and the flame shape changes from conical to an elongated columnar shape, especially in hydrogen-enriched flames. There are two different modes of vortex breakdown observed, spiral mode in methane flames and bubble mode in hydrogen-enriched flames. These differences between the behavior of the methane-only and hydrogen-enriched flames lead to different behavior of the flame as it approaches the lean blowout. The differences in the mechanisms of LBO in pure methane and hydrogen-enriched premixed flames are examined and explained in the present study.
Potential Flow Theory and Numerical Analysis of Forces on Cylinders Induced by Oscillating Disturbances
Authors: Valentine Daniel T. , Madhi Farshad
Published: February 2012

The complete solution of several two-dimensional potential flow problems are reported that deal with the unsteady flow around circular cylinders. Three of the flows considered are induced by an oscillating disturbance near the cylinder. The three elemental disturbances examined are (1) a pulsating source, (2) a pulsating doublet, and (3) a pulsating vortex. The formulas for the force acting on the cylinder due to each of the elemental disturbances were derived by applying the method of images. These results were checked by deriving the equivalent surface distribution of sources to model the cylinder by applying Green’s second identity. The theory helped direct the development of a boundary-integral numerical model described and applied in this paper to solve the unsteady flow around a circular cylinder due to an arbitrarily specified oscillatory disturbance near the cylinder. The numerical method is validated by comparing predictions of the force with the exact solutions. We applied the theory to examine a model problem related to the vortex-shedding force that causes vortex-induced vibration.
Resonant Bending Fatigue Test Setup for Pipes With Optical Displacement Measuring System
Authors: Van Wittenberghe Jeroen , De Baets Patrick , De Waele Wim , Ost Wouter , Verstraete Matthias , Hertelé Stijn
Published: February 2012

Pipes and tubular members are used in offshore applications as structural elements, such as columns or in transport pipelines, risers, etc. When subjected to dynamic loads, weld defects or geometrical stress raisers can initiate fatigue cracks, causing the columns or pipelines to fail prematurely. In order to investigate the fatigue behavior of pipe joints, a resonant bending fatigue setup was designed, suitable for testing pipes within a diameter range from 6 in. to 20 in. In this setup, the pipe, filled with water, is subjected to a dynamic excitation force with a frequency close to the natural frequency of the filled pipe. The force is applied using a unique drive unit with excentric masses. The pipe is supported in the nodes of its natural wave-form, so that no dynamic forces are transmitted to the setup. The deformation of the pipe is measured at discrete locations using an optical 3D dynamic measuring system. Through-thickness fatigue cracks can be detected by pressurizing the water in the pipe and applying a pressure gauge. In this paper, some unique aspects of the design of the resonant bending fatigue setup are discussed by presenting the results of a semianalytical model used for calculating the deformation and bending stress in the excitated pipe and by comparing these results to the deformation measurements made by the dynamic measuring system. The working principles of the setup are illustrated by showing the preliminary test results for a 12 in. diameter X65 steel pipe with a wall thickness of 12.7 mm. It is demonstrated that the model predicts the behavior of the pipe in the setup very accurately.
A Comparative Wet Collapse Buckling Study for the Carcass Layer of Flexible Pipes
Authors: Gay Neto Alfredo , de Arruda Martins Clóvis
Published: February 2012

When there is a failure on the external sheath of a flexible pipe, a high value of hydrostatic pressure is transferred to its internal plastic layer and consequently to its interlocked carcass, leading to the possibility of collapse. The design of a flexible pipe must predict the maximum value of external pressure the carcass layer can be subjected to without collapse. This value depends on the initial ovalization due to manufacturing tolerances. To study that problem, two numerical finite element models were developed to simulate the behavior of the carcass subjected to external pressure, including the plastic behavior of the materials. The first one is a full 3D model and the second one is a 3D ring model, both composed by solid elements. An interesting conclusion is that both the models provide the same results. An analytical model using an equivalent thickness approach for the carcass layer was also constructed. A good correlation between analytical and numerical models was achieved for pre-collapse behavior but the collapse pressure value and post-collapse behavior were not well predicted by the analytical model.
Individual Pitch Control of Horizontal Axis Wind Turbines
Authors: Sandquist Fredrik , Moe Geir , Anaya-Lara Olimpo
Published: February 2012

An individual pitch controller (IPC) based on the multivariable Linear Quadratic Gaussian (LQG) concept is presented to reduce loads in megawatt-size wind turbines. Most turbines currently installed use collective pitch control to pitch the blades in order to limit the excess of wind power and to regulate the rotor speed above rated conditions. However, research has shown that IPC control is much more effective to reduce blade loads. Both collective and individual pitch control are implemented for the NREL 5 MW reference turbine. Simulation results are used to illustrate the advantage of the IPC approach, and its ability to reduce much of the flap-wise blade motion is demonstrated.
In vitro Articular Cartilage Growth with Sequential Application of IGF-1 and TGF-β1 Enhances Volumetric Growth and Maintains Compressive Properties
Authors: Balcom Nathan T. , Berg-Johansen Britta , Dills Kristin J. , Van Donk Jennifer R. , Williams Gregory M. , Chen Albert C. , Hazelwood Scott J. , Sah Robert L. , Klisch Stephen M.
Published: February 2012

In vitro cultures with insulin-like growth factor-1 (IGF-1) and transforming growth factor-β1 (TGF-β1) have previously been shown to differentially modulate the growth of immature bovine articular cartilage. IGF-1 stimulates expansive growth yet decreases compressive moduli and increases compressive Poisson’s ratios, whereas TGF-β1 maintains tissue size, increases compressive moduli, and decreases compressive Poisson’s ratios. The current study’s hypothesis was that sequential application of IGF-1 and TGF-β1 during in vitro culture produces geometric and compressive mechanical properties that lie between extreme values produced when using either growth factor alone. Immature bovine articular cartilage specimens were harvested and either untreated (D0, i.e., day zero) or cultured in vitro for either 6 days with IGF-1 (D6 IGF), 12 days with IGF-1 (D12 IGF), or 6 days with IGF-1 followed by 6 days with TGF-β1 (D12 SEQ, i.e., sequential). Following treatment, all specimens were tested for geometric, biochemical, and compressive mechanical properties. Relative to D0, D12 SEQ treatment enhanced volumetric growth, but to a lower value than that for D12 IGF. Furthermore, D12 SEQ treatment maintained compressive moduli and Poisson’s ratios at values higher and lower, respectively, than those for D12 IGF. Considering the previously described effects of 12 days of treatment with TGF-β1 alone, D12 SEQ induced both growth and mechanical property changes between those produced with either IGF-1 or TGF-β1 alone. The results suggest that it may be possible to vary the durations of select growth factors, including IGF-1 and TGF-β1, to more precisely modulate the geometric, biochemical, and mechanical properties of immature cartilage graft tissue in clinical repair strategies.
Molecular beam epitaxial growth and characterization of nitrogen δ-doped AlGaAs/GaAs quantum wells
Authors: Furuse Shin-ichiro , Sumiya Kengo , Morifuji Masato , Ishikawa Fumitaro
Published: February 2012

The authors carry out δ-doping at the middle of AlGaAs/GaAs quantum wells employing molecular beam epitaxy and varying the nitrogen coverage up to 0.5 monolayers. Transmission electron micrography and x ray diffraction indicate the introduction of a nitrogen δ-doped layer with precisely controlled position and nitrogen coverage. Photoluminescence spectra obtained for the samples show clear redshift of spectral peak positions depending on the amount of nitrogen, suggesting the band structure is modified by the δ-doping. The growth can be carried out at a substrate temperature of 560 °C. The growth temperature, which is high compared with that of standard dilute nitride compounds, could suppress the formation of growth-induced defects, resulting in the weak effect of post-growth thermal annealing on the characteristics of room-temperature photoluminescence.
Blueshift in sulfur treated GaAsP/AlGaAs near surface quantum well
Authors: Pal Suparna , Singh S. D. , Porwal S. , D’Souza S. W. , Barman S. R. , Oak S. M.
Published: February 2012

Large blueshift was observed in a near-surface GaAs0.86P0.14/Al0.7Ga0.3As quantum well upon treatment with Na2S·xH2O solution. Very slow etching with simultaneous surface passivation of the quantum well was obtained using this chemical treatment. Photoreflectance (PR) spectra exhibit maximum blueshift of 28 meV after treating the quantum well surface with Na2S·xH2O solution for 30 min (top layer thickness reduced to 10 Å). The blueshift is attributed to an increase in the confinement and/or an image charge effect due to the penetration of the wave function into vacuum. The blueshift is accompanied by a significant reduction in the broadening parameter of the observed e1-lh1 transition in PR spectra indicating effective passivation along with an increase in the confinement.
Using Health Information Technology to Engage Communities in Health, Education, and Research
Authors: Marriott Lisa K. , Nelson David A. , Allen Shauntice , Calhoun Karen , Eldredge Christina E. , Kimminau Kim S. , Lucero Robert J. , Pineda-Reyes Fernando , Rumala Bernice B. , Varanasi Arti P. , Wasser June S. , Shannon Jackilen
Published: February 2012

The Internet can be used for personal health management as well as to facilitate partnerships and data-sharing in a community setting.
A One-Two Punch to the Hepatitis C Virus
Authors: Gesty-Palmer Diane
Published: February 2012

Combination treatment of hepatitis C infection with a replication inhibitor and a protease inhibitor shows promise.
Ecological Succession of Bacterial Communities during Conventionalization of Germ-Free Mice
Authors: Gillilland Merritt G. , Erb-Downward John R. , Bassis Christine M. , Shen Michael C. , Toews Galen B. , Young Vincent B. , Huffnagle Gary B.
Published: January 2012

Little is known about the dynamics of early ecological succession during experimental conventionalization of the gastrointestinal (GI) tract; thus, we measured changes in bacterial communities over time, at two different mucosal sites (cecum and jejunum), with germfree C57BL/6 mice as the recipients of cecal contents (input community) from a C57BL/6 donor mouse. Bacterial communities were monitored using pyrosequencing of 16S rRNA gene amplicon libraries from the cecum and jejunum and analyzed by a variety of ecological metrics. Bacterial communities, at day 1 postconventionalization, in the cecum and jejunum had lower diversity and were distinct from the input community (dominated by either
Escherichia
or
Bacteroides
). However, by days 7 and 21, the recipient communities had become significantly diverse and the cecal communities resembled those of the donor and donor littermates, confirming that transfer of cecal contents results in reassembly of the community in the cecum 7 to 21 days later. However, bacterial communities in the recipient jejunum displayed significant structural heterogeneity compared to each other or the donor inoculum or the donor littermates, suggesting that the bacterial community of the jejunum is more dynamic during the first 21 days of conventionalization. This report demonstrates that (i) mature input communities do not simply reassemble at mucosal sites during conventionalization (they first transform into a “pioneering” community and over time take on the appearance, in membership and structure, of the original input community) and (ii) the specific mucosal environment plays a role in shaping the community.