MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 2 2008
The 37 brightest radio sources
ABSTRACT We study the 37 brightest radio sources in the Subaru/XMM,Newton Deep Field. We have spectroscopic redshifts for 24 of 37 objects and photometric redshifts for the remainder, yielding a median redshift zmed for the whole sample of zmed, 1.1 and a median radio luminosity close to the ,Fanaroff,Riley type I/type II (FR I/FR II)' luminosity divide. Using mid-infrared (mid-IR) (Spitzer MIPS 24 ,m) data we expect to trace nuclear accretion activity, even if it is obscured at optical wavelengths, unless the obscuring column is extreme. Our results suggest that above the FR I/FR II radio luminosity break most of the radio sources are associated with objects that have excess mid-IR emission, only some of which are broad-line objects, although there is one clear low-accretion-rate object with an FR I radio structure. For extended steep-spectrum radio sources, the fraction of objects with mid-IR excess drops dramatically below the FR I/FR II luminosity break, although there exists at least one high-accretion-rate ,radio-quiet' QSO. We have therefore shown that the strong link between radio luminosity (or radio structure) and accretion properties, well known at z, 0.1, persists to z, 1. Investigation of mid-IR and blue excesses shows that they are correlated as predicted by a model in which, when significant accretion exists, a torus of dust absorbs ,30 per cent of the light, and the dust above and below the torus scatters ,1 per cent of the light. [source]

Postplasmic/PEM RNAs: A class of localized maternal mRNAs with multiple roles in cell polarity and development in ascidian embryos

DEVELOPMENTAL DYNAMICS, Issue 7 2007
François Prodon
Abstract Ascidian is a good model to understand the cellular and molecular mechanisms responsible for mRNA localization with the discovery of a large family of localized maternal mRNAs, called postplasmic/PEM RNAs, which includes more than 40 members in three different ascidian species (Halocynthia roretzi, Ciona intestinalis, and C. savignyi). Among these mRNAs, two types (Type I and Type II) have been identified and show two different localization patterns from fertilization to the eight-cell stage. At the eight-cell stage, both types concentrate to a macromolecular cortical structure called CAB (for Centrosome Attracting Body) in the posterior-vegetal B4.1 blastomeres. The CAB is responsible for unequal cleavages and the partitioning of postplasmic/PEM RNAs at the posterior pole of embryos during cleavage stages. It has also been suggested that the CAB region could contain putative germ granules. In this review, we discuss recent data obtained on the distribution of Type I postplasmic/PEM RNAs from oogenesis to late development, in relation to their localization and translational control. We have first regrouped localization patterns for Type I and Type II into a comparative diagram and included all important definitions in the field. We also have made an exhaustive classification of their embryonic expression profiles (Type I or Type II), and analyzed their functions after knockdown and/or overexpression experiments and the role of the 3,-untranslated region (3,UTR) controlling both their localization and translation. Finally, we propose a speculative model integrating recent data, and we also discuss the relationship between postplasmic/PEM RNAs, posterior specification, and germ cell formation in ascidians. Developmental Dynamics 236:1698,1715, 2007. © 2007 Wiley-Liss, Inc. [source]

Degeneration of germ line cells in amphibian ovary

ACTA ZOOLOGICA, Issue 3 2010
Maria Ogielska
Abstract Ogielska, M., Rozenblut, B., Augusty,ska, R., Kotusz, A. 2010. Degeneration of germ line cells in amphibian ovary. ,Acta Zoologica (Stockholm) 91: 319,327 We studied the morphology of degenerating ovarian follicles in juvenile and adult frogs Rana temporaria, Rana lessonae and Rana ridibunda. Degeneration of primordial germ cells was never observed and was extremely rare in oogonia and early oocytes in a cyst phase in juveniles. Previtellogenic oocytes were rarely affected. Three main types of atresia were identified. In type I (subdivided into stages A,D), vitellogenic oocytes are digested by proliferating follicle cells that hypertrophy and become phagocytic. A , germinal vesicle shrinks, nucleoli fuse, oocyte envelope interrupts, and follicular cells hypertrophy; B , follicular cells multiply and invade the oocyte; C , entire vesicle is filled by phagocytic cells; D , degenerating phagocytes accumulate black pigment. Type II is rare and resembles breakdown of follicles and release of ooplasm. In type III, observed in previtellogenic and early vitellogenic oocytes, ooplasm and germinal vesicle shrink, follicle cells do not invade the vesicle, and condensed ooplasm becomes fragmented. The residual oogonia in adult ovaries (germ patches) multiply, but soon degenerate. [source]

Association of Bicuspid Aortic Valve Morphology and Aortic Root Dimensions: A Substudy of the Aortic Stenosis Progression Observation Measuring Effects of Rosuvastatin (ASTRONOMER) Study

ECHOCARDIOGRAPHY, Issue 2 2010
Davinder S. Jassal M.D., F.R.C.P.C.
Background: Bicuspid aortic valve (BAV) is the leading cause of aortic stenosis in patients younger than the age of 50. A classification scheme of BAVs is based upon leaflet orientation: Type I (fusion of right and left coronary cusps) and Type II (fusion of right and noncoronary cusps). The correlation between BAV leaflet orientation and aortic root pathology however remains ill defined. Objective: The objective was to describe a potential relationship between BAV leaflet morphology and aortic root measurements in the ASTRONOMER study, a multicenter study to assess the effect of rosuvastatin on the progression of AS. Methods: BAV morphology was classified as Type I or Type II orientation based on the parasternal short-axis view. Echo measurements including left ventricular and aortic root dimensions were obtained. Results: The study population included 89 patients (56 ± 11 years; 44 males). There were 63 patients with Type I and 26 patients with Type II BAV. Baseline demographics, hemodynamics, and left heart dimensions were similar between both groups. Patients with Type I BAV had larger aortic annulus and ascending root dimensions compared to those patients with Type II BAV (P < 0.05). Conclusion: In patients with mild to moderate aortic stenosis due to a BAV, the presence of Type I valve orientation was associated with significantly greater aortic root parameters compared to Type II valve orientation. (ECHOCARDIOGRAPHY 2010;27:174-179) [source]

Anaerobic arsenite oxidation by novel denitrifying isolates

ENVIRONMENTAL MICROBIOLOGY, Issue 5 2006
E. Danielle Rhine
Summary Autotrophic microorganisms have been isolated that are able to derive energy from the oxidation of arsenite [As(III)] to arsenate [As(V)] under aerobic conditions. Based on chemical energetics, microbial oxidation of As(III) can occur in the absence of oxygen, and may be relevant in some environments. Enrichment cultures were established from an arsenic contaminated industrial soil amended with As(III) as the electron donor, inorganic C as the carbon source and nitrate as the electron acceptor. In the active enrichment cultures, oxidation of As(III) was stoichiometrically coupled to the reduction of NO3,. Two autotrophic As(III)-oxidizing strains were isolated that completely oxidized 5 mM As(III) within 7 days under denitrifying conditions. Based on 16S rRNA gene sequencing results, strain DAO1 was 99% related to Azoarcus and strain DAO10 was most closely related to a Sinorhizobium. The nitrous oxide reductase (nosZ) and the RuBisCO Type II (cbbM) genes were successfully amplified from both isolates underscoring their ability to denitrify and fix CO2 while coupled to As(III) oxidation. Although limited work has been done to examine the diversity of anaerobic autotrophic oxidizers of As(III), this process may be an important component in the biological cycling of arsenic within the environment. [source]

Differential Effects of Cold Exposure on Muscle Fibre Composition and Capillary Supply in Hibernator and Non-Hibernator Rodents

EXPERIMENTAL PHYSIOLOGY, Issue 5 2001
S. Egginton
Changes in the composition of fibre types and the capillary supply of skeletal muscle (tibialis anterior) were quantified in rats and hamsters subjected to 8-10 weeks of cold exposure and reduced photoperiod (10 °C, 1 h light-23 h dark). Muscle mass decreased in both species (by 12% and 17%, respectively). Following acclimation to cold there were no specific changes in fibre cross-sectional area (FCSA) in rats, whereas in hamsters there was a substantial atrophy of Type II, but not Type I fibres. In rat muscle there was little difference between the two groups in average capillary to fibre ratio (C:F) (1.76 ± 0.15, normothermia, N; 1.69 ± 0.05, hypothermia, H) and average capillary density (CD) (188 ± 14 mm,2, N; 201 ± 12 mm -2, H). Similarly, the average C:F was unaltered in hamsters (2.75 ± 0.11, N; 2.72 ± 0.15, H), although the 30% smaller fibre size observed with hypothermia resulted in a corresponding increase in average CD, to 1539 ± 80 mm,2 (P < 0.01). However, there was a coordinated regional adaptation to cold exposure in hamsters resulting in capillary rarefaction in the glycolytic cortex and angiogenesis in the oxidative core. Following acclimation of rats to cold there was a reduction in the supply area of individual vessels (capillary domain), particularly in the cortex (9310, N; 8938 ,m2, H; P < 0.05). In contrast, hypothermic hamsters showed only a small decrease in mean domain area in the cortex (948 ,m2, N; 846 ,m2, H; n.s.) but a marked reduction in the core (871 ,m2, N; 604 ,m2, H; P < 0.01). Rats showed little or no change in local capillary supply (LCFR) to fast fibres on acclimation to cold, while in hamsters the LCFR of Type IIb fibres showed a decrease in the cortex (2.7, N; 2.3, H) and an increase in the core (3.0, N; 3.3, H) during acclimation to cold. These data suggest that during a simulated onset of winter rats maintain FCSA and capillary supply as part of an avoidance strategy, whereas hamsters increase muscle capillarity in part as a consequence of disuse atrophy. [source]

Identity of active methanotrophs in landfill cover soil as revealed by DNA-stable isotope probing

FEMS MICROBIOLOGY ECOLOGY, Issue 1 2007
Aurélie Cébron
Abstract A considerable amount of methane produced during decomposition of landfill waste can be oxidized in landfill cover soil by methane-oxidizing bacteria (methanotrophs) thus reducing greenhouse gas emissions to the atmosphere. The identity of active methanotrophs in Roscommon landfill cover soil, a slightly acidic peat soil, was assessed by DNA-stable isotope probing (SIP). Landfill cover soil slurries were incubated with 13C-labelled methane and under either nutrient-rich nitrate mineral salt medium or water. The identity of active methanotrophs was revealed by analysis of 13C-labelled DNA fractions. The diversity of functional genes (pmoA and mmoX) and 16S rRNA genes was analyzed using clone libraries, microarrays and denaturing gradient gel electrophoresis. 16S rRNA gene analysis revealed that the cover soil was mainly dominated by Type II methanotrophs closely related to the genera Methylocella and Methylocapsa and to Methylocystis species. These results were supported by analysis of mmoX genes in 13C-DNA. Analysis of pmoA gene diversity indicated that a significant proportion of active bacteria were also closely related to the Type I methanotrophs, Methylobacter and Methylomonas species. Environmental conditions in the slightly acidic peat soil from Roscommon landfill cover allow establishment of both Type I and Type II methanotrophs. [source]

Ecophysiology of the filamentous Alphaproteobacterium Meganema perideroedes in activated sludge

FEMS MICROBIOLOGY ECOLOGY, Issue 1 2005
Caroline Kragelund
Abstract A comprehensive study of the ecophysiology of the filamentous Meganema perideroedes affiliated to the Alphaproteobacteria, possessing a "Nostocoida limicola Type II" filamentous morphology was conducted. This morphotype often causes serious bulking problems in activated sludge wastewater treatment plants, and hardly anything is known about its physiology. The study was carried out by applying a suite of in situ methods in an industrial activated sludge treatment plant with excessive growth of this species. The experiments revealed a very versatile organism able to take up a large variety of organic substrates under aerobic conditions. It had a remarkably high storage capacity forming polyhydroxyalkanoates from most substrates tested. When nitrate was present as e-acceptor, the number of substrates to be consumed by M. perideroedes was more restricted compared to aerobic conditions. With nitrite as e-acceptor, only acetate and glucose among the substrates tested could be assimilated and used for storage and possibly growth. This indicated that M. perideroedes might be able to denitrify under certain conditions, which is unusual for filamentous bacteria in activated sludge. No substrate uptake or storage was seen under anaerobic conditions. M. perideroedes was relatively hydrophobic, compared to other filamentous bacteria and microcolonies present in the sludge, indicating the presence of a hydrophobic sheath. Several excreted surface-associated exoenzymes were detected in the sludge, but M. perideroedes never showed any activity, except once after a breakdown in the production facility. This confirmed that M. perideroedes mainly grows on soluble substrates. Based on the studies of the ecophysiology of M. perideroedes, potential control strategies are suggested. [source]

Tectono-sedimentary evolution of the northernmost margin of the NE German Basin between uppermost Carboniferous and Late Permian (Rotliegend)

GEOLOGICAL JOURNAL, Issue 1 2001
H. Rieke
Abstract The tectono-sedimentary evolution of the Rotliegend deposits of the northernmost margin of NE German Basin (NEGB) has been analysed on the basis of detailed sedimentary logs of 300,m of core material together with the re-evaluation of 600,km of seismic lines. Three distinct phases were recognized. During the initial Phase I, basin geometry was largely controlled by normal faulting related to deep-seated ductile shearing leading to a strong asymmetric shape, with a steep fault-controlled eastern margin and a gently, dipping western margin. The results of forward modelling along a cross-section fit the basin geometry in width and depth and reveal a footwall uplift of c. 1000,m. Adjacent to the steep faults, local sedimentation of Lithofacies Type I was confined to non-cohesive debris flow-dominated alluvial fans, whereas the gently dipping western margin was dominated by alluvial-cone sedimentation. During the post-extensional period (Phase II), cooling of the lithosphere generated additional accommodation space. The sediments of Lithofacies Type II, comprising mainly clast-supported conglomerates, are interpreted as braided ephemeral stream flow-surge deposits. Tectonic quiescence and an increase in flood events resulting from wetter climate led to progradation of this facies over the entire region. At the end of this period, the accommodation space was almost completely filled resulting in a level topography. Phase III was controlled by the thermal-induced subsidence of the southerly located NEGB in post-Illawarra times. The formerly isolated region tilted towards the SW, thus forming the northern margin of the NEGB during uppermost Havel and Elbe Subgroup times. The sediments of Lithofacies Type III were divided into a marginal sandstone-dominated environment and a finer-grained facies towards the SW. The former consists of poorly-sorted coarse-grained sandstones of a proximal and medial ephemeral stream floodplain facies. The latter comprise mud flat fines and fine-grained distal ephemeral stream deposits. The end of the tectono-sedimentary evolution is marked by the basinwide Zechstein transgression. Copyright © 2001 John Wiley & Sons, Ltd. [source]

Impact of glucose levels on advanced glycation end products in hemodialysis

HEMODIALYSIS INTERNATIONAL, Issue 3 2007
Amy Ruth GODFREY
Abstract The current obesity epidemic throughout the western world has resulted in a considerable increase in the condition Type II diabetes mellitus. Recently, the World Health Organization has predicted that the global prevalence of Type II will increase from 175 million patients in 2003 to over 350 million by 2030. One of the major consequences of this disorder is renal failure, which presents itself as chronic kidney disease, and can progress to end-stage renal disease. Once diagnosed, patients are generally treated using dialysis due to a shortage of kidney donors. The fundamental process of dialysis still requires improvement because the survival rate of these patients is relatively poor. This has resulted in considerable research into improvements in hemodialysis membranes, and the challenge to find more suitable marker(s) in assessing the efficacy of the dialysis process. A class of compounds highlighted as a possible accumulative toxin is advanced glycation end products or AGEs. This is an article regarding the impact of hemodialysis and hemodiafiltration on glucose and AGE levels within the body and the consequences of a chronic hyperglycemic condition. It also highlights the negative aspects of using dextrose in conventional dialysis solutions (an area that has already been identified by peritoneal dialysis clinicians as problematic). The review concludes by suggesting several possible topics of future research. [source]

CoagMDB: a database analysis of missense mutations within four conserved domains in five vitamin K,dependent coagulation serine proteases using a text-mining tool,

HUMAN MUTATION, Issue 3 2008
Rebecca E. Saunders
Abstract Central repositories of mutations that combine structural, sequence, and phenotypic information in related proteins will facilitate the diagnosis and molecular understanding of diseases associated with them. Coagulation involves the sequential activation of serine proteases and regulators in order to yield stable blood clots while maintaining hemostasis. Five coagulation serine proteases,factor VII (F7), factor IX (F9), factor X (F10), protein C (PROC), and thrombin (F2),exhibit high sequence similarities and all require vitamin K. All five of these were incorporated into an interactive database of mutations named CoagMDB (http://www.coagMDB.org; last accessed: 9 August 2007). The large number of mutations involved (especially for factor IX) and the increasing problem of out-of-date databases required the development of new database management tools. A text mining tool automatically scans full-length references to identify and extract mutations. High recall rates between 96 and 99% and precision rates of 87 to 93% were achieved. Text mining significantly reduces the time and expertise required to maintain the databases and offers a solution to the problem of locus-specific database management and upkeep. A total of 875 mutations were extracted from 1,279 literature sources. Of these, 116 correspond to Gla domains, 86 to the N-terminal EGF domain, 73 to the C-terminal EGF domain, and 477 to the serine protease domain. The combination of text mining and consensus domain structures enables mutations to be correlated with experimentally-measurable phenotypes based on either low protein levels (Type I) or reduced functional activities (Type II), respectively. A tendency for the conservation of phenotype with structural location was identified. Hum Mutat 29(3), 333,344, 2008. © 2007 Wiley-Liss, Inc. [source]

Anchor ice formation in streams: a field study

HYDROLOGICAL PROCESSES, Issue 16 2009
Morten Stickler
Abstract In northern steep streams anchor ice is commonly observed during winter, and plays a key role when considering in-stream conditions. The understanding, however, of the nature of anchor ice formation is less understood, in particular, under natural conditions. In the following, observations of anchor ice formation in three stream environments with different physical characteristics are presented. Results demonstrate that anchor ice not only form in riffle areas, but also in shallow and slow running stream sections. No linkage between spatial distribution of anchor ice and calculated dimensionless numbers (Froude and Reynolds number) was found. Furthermore, analyses on growth and density showed that anchor ice may be distinguished by two main types. (1) Type I: Lower density forming on top of substrata. (2) Type II: Higher density forming between the substrata filling interstitial spaces. Distribution of anchor ice Types I and II suggests a relation between intensity of turbulence expressed by the Reynolds number, growth pattern and density. As anchor ice has both physical and biological implications on in-stream environments, findings from the present study may be of particular interest to cold region freshwater stream management. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Analysing the effect of novel therapies on cytokine expression in experimental arthritis

INTERNATIONAL JOURNAL OF EXPERIMENTAL PATHOLOGY, Issue 5 2005
Richard O. Williams
Summary Type II collagen-induced arthritis (CIA) is an animal model of rheumatoid arthritis that has been used extensively to address questions of disease pathogenesis and to validate novel therapeutic targets. Susceptibility to CIA is strongly associated with major histocompatibility complex class II genes, and the development of arthritis is accompanied by a robust T- and B-cell response to type II collagen. The main pathological features of CIA include proliferative synovitis with infiltration of inflammatory cells, pannus formation, cartilage degradation, erosion of bone and fibrosis. Pro-inflammatory cytokines, such as tumour necrosis factor , and interleukin-1,, are expressed in the arthritic joints in both murine CIA and human rheumatoid arthritis, and blockade of these molecules results in amelioration of disease. Hence, there is a great deal of interest in the development of small-molecular-weight inhibitors of pro-inflammatory cytokines. There is also interest in the development and testing of drugs with the capacity to modulate the immune pathways involved in driving the inflammatory response in arthritis. For these reasons, there is a need to monitor the effect of novel treatments on cytokine expression in vivo. In this review, we outline the various techniques used to detect cytokines in experimental arthritis and describe how these techniques have been used to quantify changes in cytokine expression following therapeutic intervention. [source]

Effect of temperature and initial moisture content on sorption isotherms of banana dried by tunnel drier

INTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 8 2008
Zhengyong Yan
Summary Sorption isotherms of intermediate moisture content (IMC) products are essential to predict shelf-life of packaged moisture-sensitive product by modelling moisture uptake during storage and distribution. The effect of temperature and initial moisture content (MC) of IMC banana on the relationship between MC and water activity were investigated. Raw bananas were dried in a tunnel dryer at 2% relative humidity (RH), 70 °C, and a 3.2 ± 0.2 m s,1 air velocity. Drying procedure was carried out a number of times until various IMC levels were obtained (5%, 14%, 22% and 33% db for banana). Sorption isotherms of bananas were determined at 10, 20, 30 and 40 °C. The initial MC of IMC banana had no significant effect on the relationship between MC and water activity according to statistical analysis. All the sorption curves were found to be Type II. BET, GAB, modified GAB, Oswin, Halsey and modified Freundlich models were fitted to the data and it was found that the best results were obtained with a modified Freundlich equation. A secondary modified Freundlich model was built accounting for the effect of aw and temperature on the sample MC. [source]

Structure,function studies of glutamate synthases: A class of self-regulated iron-sulfur flavoenzymes essential for nitrogen assimilation

IUBMB LIFE, Issue 5 2008
Maria Antonietta Vanoni
Abstract Glutamate synthases play with glutamine synthetase an essential role in nitrogen assimilation processes in microorganisms, plants, and lower animals by catalyzing the net synthesis of one molecule of L -glutamate from L -glutamine and 2-oxoglutarate. They exhibit a modular architecture with a common subunit or region, which is responsible for the L -glutamine-dependent glutamate synthesis from 2-oxoglutarate. Here, a PurF- (Type II- or Ntn-) type amidotransferase domain is coupled to the synthase domain, a (,/,)8 barrel containing FMN and one [3Fe-4S]0,+1 cluster, through a ,30 Å-long intramolecular tunnel for the transfer of ammonia between the sites. In bacterial and eukaryotic GltS, reducing equivalents are provided by reduced pyridine nucleotides thanks to the stable association with a second subunit or region, which acts as a FAD-dependent NAD(P)H oxidoreductase and is responsible for the formation of the two low potential [4Fe-4S]+1,+2 clusters of the enzyme. In photosynthetic cells, reduced ferredoxin is the physiological reductant. This review focus on the mechanism of cross-activation of the synthase and glutaminase reactions in response to the bound substrates and the redox state of the enzyme cofactors, as well as on recent information on the structure of the ,, protomer of the NADPH-dependent enzyme, which sheds light on the intramolecular electron transfer pathway between the flavin cofactors. © 2008 IUBMB IUBMB Life, 60(5): 287,300, 2008 [source]

Predation of beech seed by mice: effects of numerical and functional responses

JOURNAL OF ANIMAL ECOLOGY, Issue 6 2005
WENDY A. RUSCOE
Summary 1The functional response of post-dispersal seed predators (house mouse, Mus musculus) to absolute densities of southern beech seed (Nothofagus solandri var. cliffortioides) was studied in laboratory and field trials. House mice showed a Type II (hyperbolic) functional response to seed availability and this was not modified by the presence of an alternative food source. 2Maximum daily intake rate of beech seeds during field trials averaged 1042 seeds mouse,1. This is sufficient to provide house mice with both the energy and protein required for growth and reproduction. 3We explicitly incorporated the functional response into the numerical response of house mice to beech seed, measured for field populations monitored in a New Zealand beech forest. House mice showed a strong numerical response to beech seed intake rate that was modified by some density-dependent mechanism(s). 4We developed a model that simulated seedfall, house mouse population growth and seed reserve depletion over one year. We found that the previously reported decline in house-mouse populations in beech forests during spring and summer is likely to be related to spring beech seed germination that renders seed no longer available as a food source for house mice. 5From our simulation model it does not appear that house-mouse populations can completely eat-out beech seed reserves prior to germination in a year of large seedfall. ,Masting' behaviour in New Zealand native beech trees is therefore sufficient to satiate an eruptive population of an exotic mammalian omnivore, despite the lack of a long co-evolutionary interaction. [source]

Joint properties of cast Fe-Pt magnetic alloy laser welded to gold alloys

JOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 1 2006
Ikuya Watanabe
Abstract This study investigated the joint properties of a cast Fe-Pt magnetic alloy (Fe-36 at % Pt) laser welded to three gold alloys. The gold alloys used were ADA Type II and Type IV gold alloys, and an Ag-based (Ag-Au) gold alloy. Cast plates (0.5 × 3.0 × 10 mm) were prepared for each alloy. After the cast Fe-Pt plates were heat treated, they were butted against each of the three alloys and then laser welded with Nd:YAG laser at 200 V. Homogeneously welded specimens were also prepared for each alloy. Tensile testing was conducted at a crosshead speed of 1 mm/min. Failure load (N) and elongation (%) were recorded. After tensile testing, the fractured surfaces were examined with the use of SEM. The failure-load values of the group of alloys welded homogeneously were ranked in the order of: Ag-Au alloy > Type IV alloy > Type II alloy > Fe-Pt alloy. The Type IV alloy welded to Fe-Pt alloy had the highest failure-load value among the three alloys tested. The elongation results tended to follow a similar pattern. The results of this study indicated that Type IV gold alloy is a suitable alloy for metal frameworks to which cast Fe-Pt magnetic alloy is laser welded. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006 [source]

Primary mouse embryonic fibroblasts: A model of mesenchymal cartilage formation,

JOURNAL OF CELLULAR PHYSIOLOGY, Issue 3 2004
Christopher J. Lengner
Cartilage formation is an intricate process that requires temporal and spatial organization of regulatory factors in order for a mesenchymal progenitor cell to differentiate through the distinct stages of chondrogenesis. Gene function during this process has best been studied by analysis of in vivo cartilage formation in genetically altered mouse models. Mouse embryonic fibroblasts (MEFs) isolated from such mouse models have been widely used for the study of growth control and DNA damage response. Here, we address the potential of MEFs to undergo chondrogenic differentiation. We demonstrate for the first time that MEFs can enter and complete the program of chondrogenic differentiation ex vivo, from undifferentiated progenitor cells to mature, hypertrophic chondrocytes. We show that chondrogenic differentiation can be induced by cell,cell contact or BMP-2 treatment, while in combination, these conditions synergistically enhance chondrocyte differentiation resulting in the formation of 3-dimensional (3-D) cartilaginous tissue ex vivo. Temporal expression profiles of pro-chondrogenic transcription factors Bapx1 and Sox9 and cartilaginous extracellular matrix (ECM) proteins Collagen Type II and X (Coll II and Coll X) demonstrate that the in vivo progression of chondrocyte maturation is recapitulated in the MEF model system. Our findings establish the MEF as a powerful tool for the generation of cartilaginous tissue ex vivo and for the study of gene function during chondrogenesis. © 2004 Wiley-Liss, Inc. [source]

RELATIONSHIP BETWEEN ORGANIC MATTER, SULPHUR AND PHOSPHATE CONTENTS IN UPPER CRETACEOUS MARINE CARBONATES (KARABOGAZ FORMATION, SE TURKEY): IMPLICATIONS FOR EARLY OIL GENERATION

JOURNAL OF PETROLEUM GEOLOGY, Issue 4 2010
S. Inan
In this paper, we discuss the relationship between the organic matter, sulphur and phosphate contents of Upper Cretaceous marine carbonates (Karabogaz Formation) in the Adiyaman Petroleum Province of SE Turkey. The results of organic geochemical analyses of core samples obtained from the Karabogaz Formation suggest that phosphate deposition occurred in settings where the water column was oxic to sub-oxic. However, the preservation of organic matter was favoured in anoxic environments. Moreover, the presence of sulphur (especially sulphur incorporated into kerogen) in organic matter-rich layers led to early oil generation. The results of stepwise py-gc analyses are consistent with a model in which, with increasing maturity, S-S and C-S bonds are the first to be eliminated from the macromolecular kerogen structure. Study of the maturity evolution of S-rich kerogen by laboratory pyrolysis implies that marginally mature and/or mature kerogen in the Karabogaz Formation, which may be classified as classic "Type II" kerogen, was most probably Type II/S at lower maturity stages. This enabled oil generation to occur at relatively shallow burial depths and relatively early stages of maturation. It is reasonable to conclude that Type II/S kerogen, overlooked in previous studies, was abundant in TOC-rich intervals in the Karabogaz Formation. Early generation (and expulsion) from Type II/S kerogen may have sourced the sulphur-rich oils in the Adiyaman area oilfields. [source]

DOLOMITIZATION OF THE EARLY EOCENE JIRANI DOLOMITE FORMATION, GABES-TRIPOLI BASIN, WESTERN OFFSHORE, LIBYA

JOURNAL OF PETROLEUM GEOLOGY, Issue 4 2000
I. Y. Mriheel
Dolomitization in the early Eocene Jirani Formation in the Gabes-Tripoli Basin (offshore western Libya) occurred in two stages. Stage I dolomites are composed of two types, one associated with anhydrite (Type I) the other anhydrite free (Type II,). The stratigraphic and sedimentological settings together with petrographic and geochemical criteria suggest that dolomitization was effected by refluxed evaporative seawater. Stable isotope and trace element analyses suggest dolomitization of both Types from a fluid of near-surface seawater composition under oxidising conditions modified by evaporation. Non-luminescence and lack ofzonation of all the dolomite indicate that the dolomitizing fluids maintained a relatively constant composition. The geologic setting during the early Eocene, interpreted as hypersaline lagoon, supports an evaporative reflux origin for the anhydritic dolomite Type I. Type II developed under less saline conditions in the transition zone between lagoon and open marine shelf. Stage II dolomitization is recorded by negative isotope values in both Types I and II indicating their dissolution and recrystallization (neomorphism) by dilute solutions. A period of exposure of the overlying Jdeir Formation following a relative sea-level fall allowed ingress of meteoric waters into both the Jdeir and the underlying Jirani Formations. Flushing by meteoric waters also resulted in development of excellent secondaly porosity and caused major dissolution of anhydrite to form the anhydritic-free dolomite facies typical of Type II. Following, and possibly during, both Stages I and II, low temperature dolomites (Type IIIa) precipitated in pore spaces from residual jluids at shallow burial depths, partially occluding porosity. In the late stage of basin evolution, medium clystalline, pore-filling saddle dolomite precipitated, causing some filling of mouldic and vuggy porosity (Type IIIb). Very light oxygen isotopic signatures confirm that it developed from high temperature fluids during deep burial diagenesis. Calculation of temperatures and timings of the dolomitization and cement phases show that the main dolomitization phases and Type IIIa cements occurred in the early Eocene, and that the saddle dolomite precipitated in the Miocene; these results are consistent with age relationships established from stratigraphic, petrographic and geochemical signatures. The most common porosity includes intercrystal, vuggy and mouldic types. Porosity is both pre-dolomitization and syn-dolomitization in origin, but the latter is the most dominant. Hence, reservoir quality is largely controlled by fluid dynamics. [source]

Random poly(fluorenylene-vinylene)s containing 3,7-Dibenzothiophene-5,5-dioxide units: Synthesis, photophysical, and electroluminescence properties

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 8 2009
Roberto Grisorio
Abstract The synthesis of new random poly(arylene-vinylene)s containing the electron withdrawing 3,7-dibenzothiophene-5,5-dioxide unit was achieved by the Suzuki,Heck cascade polymerization reaction. The properties of poly[9,9-bis(2-ethylhexyl)-2,7-fluorenylene-vinylene- co -3,7-dibenzothiophene-5,5-dioxide-vinylene] (50/50 mol/mol, P1) and poly[1,4-bis(2-ethylhexyloxy)-2,5-phenylene-vinylene- co -3,7-dibenzothiophene-5,5-dioxide-vinylene] (50/50 mol/mol, P2) were compared with those of terpolymers obtained by combining the fluorene, dibenzothiophene, and 1,4-bis(2-ethylexyloxy)benzene in 20/40/40 (P3), 50/25/25 (P4), and 80/10/10 (P5) molar ratios. The polymers were characterized by 1H NMR and IR, whereas their thermal properties were investigated by TGA and DSC. Polymers P1,5 are blue,green emitters in solution (,em between 481 and 521 nm) whereas a profound red shift observed in the solid state is emission (,em from 578 to 608 nm) that can be attributed both to the charge transfer stabilization exerted by the polar medium and to intermolecular interactions occurring in the solid state. Cyclic voltammetry permitted the evaluation of the ionization potentials and also revealed a quasi-reversible behavior in the reduction scans for the polymers (P1,4) containing the higher amounts of 3,7-dibenzothiophene-5,5-dioxide units. Electroluminescent devices with both ITO/PEDOT-PSS/P1,5/Ca/Al (Type I) and ITO/PEDOT-PSS/P1,5/Alq3/Ca/Al (Type II) configuration were fabricated showing a yellow to yellow,green emission. In the case of P4, a luminance of 1835 cd/m2 and an efficiency of 0.25 cd/A at 14 V were obtained for the Type II devices. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2093,2104, 2009 [source]

Biologic and clinical variations of adenocarcinoma at the esophago,gastric junction: Relevance of a topographic-anatomic subclassification,

JOURNAL OF SURGICAL ONCOLOGY, Issue 3 2005
J. Rüdiger Siewert
Abstract A topographic-anatomic subclassification of adenocarcinomas of the esophago,gastric junction (AEG) in distal esophageal adenocarcinoma (AEG Type I), true carcinoma of the cardia (AEG Type II), and subcardial gastric cancer (AEG Type III) was introduced in 1987 and is now increasingly accepted and used worldwide. Our experience with now more than 1,300 resected AEG tumors indicates that the subtypes differ markedly in terms of surgical epidemiology, histogenesis and histomorphologic tumor characteristics. While underlying specialized intestinal metaplasia can be found in basically all patients with AEG Type I tumors, this is uncommon in Type II tumors and virtually absent in Type III tumors. Stage distribution and overall long-term survival after surgical resection also shows marked differences between the AEG subtypes. Surgical treatment strategies based on tumor type allow a differentiated approach and result in survival rates superior to those reported with other approaches. The subclassification of AEG tumors thus provides a useful tool for the selection of the surgical procedure and allows a better comparison of treatment results. J. Surg. Oncol. 2005;90:139,146. © 2005 Wiley-Liss, Inc. [source]

Types of lymphoscintigraphy and indications for lymphaticovenous anastomosis

MICROSURGERY, Issue 6 2010
Jiro Maegawa M.D.
Several authors have reported the usefulness and benefits of lymphoscintigraphy. However, it is insufficient to indicate microvascular treatment based on lymphedema. Here, we present the relationships between lymphoscintigraphic types and indications for lymphatic microsurgery. Preoperative lymphoscintigraphy was performed in 142 limbs with secondary lymphedema of the lower extremity. The images obtained were classified into five types. Type I: Visible inguinal lymph nodes, lymphatics along the saphenous vein and/or collateral lymphatics. Type II: Dermal backflow in the thigh and stasis of an isotopic material in the lymphatics. Type III: Dermal backflow in the thigh and leg. Type IV: Dermal backflow in the leg. Type V: Radiolabeled colloid remaining in the foot. Lymphaticovenous anastomosis was performed in 35 limbs. The average number of anastomoses per limb was 3.3 in type II, 4.4 in type III, 3.6 in type IV, and 3 in type V. The highest number of anastomosis was performed in type III. In conclusion, type III is suggested to be the best indication for anastomosis compared with types IV and V. © 2010 Wiley-Liss, Inc. Microsurgery 30:437,442, 2010. [source]

Acquired Cutis Laxa Type II (Marshall Syndrome) in an 18-Month-Old Child: A Case Report

PEDIATRIC DERMATOLOGY, Issue 1 2010
F.C.P.S. (Dermatology), Mansoor Haider M.B.B.S.
Type II acquired cutis laxa, shows only cutaneous changes without any systemic involvement. We describe an infant with acquired cutis laxa type II following a generalized inflammatory dermatitis. [source]

Prevalence of Interatrial Block in Healthy School-Aged Children: Definition by P-Wave Duration or Morphological Analysis

ANNALS OF NONINVASIVE ELECTROCARDIOLOGY, Issue 1 2010
F.E.S.C., Polychronis Dilaveris M.D.
Background: P waves ,110 ms in adults and ,90 ms in children are considered abnormal, signifying interatrial block, particularly in the first case. Methods: To evaluate the prevalence of interatrial block in healthy school-aged children, we obtained 12-lead digital ECGs (Cardioperfect 1.1, CardioControl NV, Delft, The Netherlands) of 664 healthy children (349 males/315 females, age range 6,14 years old). P-wave analysis indices [mean, maximum and minimum (in the 12 leads) P-wave duration, P-wave dispersion, P-wave morphology in the derived orthogonal (X, Y, Z) leads, as well the amplitude of the maximum spatial P-wave vector] were calculated in all study participants. Results: P-wave descriptor values were: mean P-wave duration 84.9 ± 9.5 ms, maximum P-wave duration 99.0 ± 9.8 ms, P dispersion 32.2 ± 12.5 ms, spatial P amplitude 182.7 ± 69.0 ,V. P-wave morphology distribution in the orthogonal leads were: Type I 478 (72.0%), Type II 178 (26.8%), Type III 1 (0.2%), indeterminate 7 (1%). Maximum P-wave duration was positively correlated to age (P < 0.001) and did not differ between sexes (P = 0.339). Using the 90-ms value as cutoff for P-wave duration, 502 (75.6%) children would be classified as having maximum P-wave duration above reference range. The 95th and the 99th percentiles were in the overall population 117 ms and 125 ms, respectively. P-wave morphology type was not in any way correlated to P-wave duration (P = 0.715). Conclusions: Abnormal P-wave morphology signifying the presence of interatrial block is very rare in a healthy pediatric population, while widened P waves are quite common, although currently classified as abnormal. Ann Noninvasive Electrocardiol 2010;15(1):17,25 [source]

Functional response of Ameca splendens (Family Goodeidae) fed cladocerans during the early larval stage

AQUACULTURE RESEARCH, Issue 14 2009
Fabiola Peña-Aguado
Abstract We studied the functional response of the goodeid Ameca splendens, an endangered species from rivers Ameca and Teuchitlán (Jalisco, Mexico), from birth until 8 weeks old. The cladocerans, Alona glabra adults, Simocephalus vetulus neonates, Ceriodaphnia dubia adults, Daphnia pulex juveniles and Moina macrocopa adults were used as prey. The prey densities, depending on the species, ranged between 0.25, 0.5, 1.0, 2.0, 4.0, 6.0, 8.0, 16.0 and 32 ind. mL,1, with four replicates at each density. We found that all functional responses were Type II. During the feeding period of 30 min, the fish larvae consumed about 600 individuals of the smallest prey A. glabra (450 ,m). The consumption of larger prey (<1.0 mm) such as S. vetulus, C. dubia, D. pulex and M. macrocopa ranged between 150 and 200 prey larva,1 during the feeding trials. Our study shows that A. splendens reached maximal prey consumption at around 4 weeks of age, after which there was no increase in prey consumption during the feeding period with age until the end of the study period of 8 weeks. Our study indicates that prey digestion rather than handling time determines the functional response in this fish species and that M. macrocopa is most suited as live food for A. splendens. [source]

Improved controllability test for dependent siphons in S3PR based on elementary siphons

ASIAN JOURNAL OF CONTROL, Issue 3 2010
Daniel Y. Chao
Abstract When siphons in a flexible manufacturing system (FMS) modeled by an ordinary Petri net (OPN) become unmarked, the net gets deadlocked. To prevent deadlocks, some control places and related arcs are added to strict minimal siphons (SMS) so that no siphon can be emptied. For large systems, it is infeasible to add a monitor to every SMS since the number of SMS or control elements grows exponentially with respect to the size of a Petri net. To tackle this problem, Li and Zhou propose to add control nodes and arcs for only elementary siphons. The rest of siphons, called dependent ones, may be controlled by adjusting control depth variables of elementary siphons associated with a dependent siphon after the failure of two tests. First, they test a Marking Linear Inequality (MLI); if it fails, then they perform a Linear Integer Programming (LIP) test which is an NP-hard problem. This implies that the MLI test is only sufficient, but not necessary. We propose a sufficient and necessary test for adjusting control depth variables in an S3PR to avoid the sufficient-only time-consuming linear integer programming (LIP) test (NP-complete problem) required previously for some cases. We theoretically prove the following: i) no need for LIP test for Type II siphons; and ii) Type I strongly n-dependent (n>2) siphons being always marked. As a result, the total time complexity to check controllability of all strongly dependent siphons is no longer exponential but reduced to linear if all siphons are of Type I. The total time complexity is O(|,E||,D|) (order of the product of total number of elementary siphons and total number of dependent siphons) if all siphons are of Type II. A well-known S3PR example has been illustrated to show the advantages. Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society [source]

Review: Studies of ferric heme proteins with highly anisotropic/highly axial low spin (S = 1/2) electron paramagnetic resonance signals with bis-Histidine and histidine-methionine axial iron coordination,

BIOPOLYMERS, Issue 12 2009
Giorgio Zoppellaro
Abstract Six-coordinated heme groups are involved in a large variety of electron transfer reactions because of their ability to exist in both the ferrous (Fe2+) and ferric (Fe3+) state without any large differences in structure. Our studies on hemes coordinated by two histidines (bis-His) and hemes coordinated by histidine and methionine (His-Met) will be reviewed. In both of these coordination environments, the heme core can exhibit ferric low spin (electron paramagnetic resonance EPR) signals with large gmax values (also called Type I, highly anisotropic low spin, or highly axial low spin, HALS species) as well as rhombic EPR (Type II) signals. In bis-His coordinated hemes rhombic and HALS envelopes are related to the orientation of the His groups with respect to each other such that (i) parallel His planes results in a rhombic signal and (ii) perpendicular His planes results in a HALS signal. Correlation between the structure of the heme and its ligands for heme with His-Met axial ligation and ligand-field parameters, as derived from a large series of cytochrome c variants, show, however, that for such a combination of axial ligands there is no clear-cut difference between the large gmax and the "small g -anisotropy" cases as a result of the relative Met-His arrangements. Nonetheless, a new linear correlation links the average shift ,,, of the heme methyl groups with the gmax values. © 2009 Wiley Periodicals, Inc. Biopolymers 91: 1064,1082, 2009. This article was originally published online as an accepted preprint. The "Published Online" date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com [source]

4233: Outcomes of the Boston Keratoprosthesis Type II

ACTA OPHTHALMOLOGICA, Issue 2010
J CHODOSH
Purpose To report the long term outcomes of Boston keratoprosthesis type II implantation in the management of severe ocular surface disease and corneal blindness. Methods A retrospective review of medical records of patients after Boston keratoprosthesis type II implantation at the Massachusetts Eye and Ear Infirmary from January, 1, 2000 through December 31, 2009. Main outcome measures included visual acuity, device retention, and postoperative complications. Results A total of 29 eyes of 26 patients received a Boston keratoprosthesis type II during the study period. Operated patients had corneal blindness due to mucous membrane pemphigoid (51.7%), Stevens Johnson syndrome/toxic epidermal necrolysis (41.4%), or other ocular surface disease (6.9%). Visual acuity after surgery improved to at least 20/200 in 23 eyes (79.3%), and to 20/30 or better in 10 eyes (34.5%). In patients with at least 1 year of follow-up (n=21), visual acuity of 20/200 or better was maintained in 14 eyes (66.7%). Of these 14 eyes, 6 eyes (42.9%) retained visual acuity of 20/200 or better for more than 5 years. Overall, visual acuity of 20/200 or better was maintained for at least 5 years in 6 of 23 eyes (26.0%). Eyes that failed to improve to 20/200 or lost vision during follow-up were found to have end stage glaucoma, previous retinal detachment, or age related macular degeneration. Of the total of 29 eyes, 17 devices (58.6%) were retained without extrusion or replacement during a total follow-up time of 107.9 person-years. Conclusion The Boston keratoprosthesis type II is a viable option for corneal blindness from severe autoimmune ocular surface diseases. Complications require prompt recognition and management to promote retention of the device and preservation of vision. [source]

Phylogenetics and Ecology: As Many Characters as Possible Should Be Included in the Cladistic Analysis,

CLADISTICS, Issue 1 2001
Philippe Grandcolas
As many data as possible must be included in any scientific analysis, provided that they follow the logical principles on which this analysis is based. Phylogenetic analysis is based on the basic principle of evolution, i.e., descent with modification. Consequently, ecological characters or any other nontraditional characters must be included in phylogenetic analyses, provided that they can plausibly be postulated heritable. The claim of Zrzavý (1997, Oikos 80, 186,192) or Luckow and Bruneau (1997, Cladistics 13, 145,151) that any character of interest should be included in the analysis is thus inaccurate. Many characters, broadly defined or extrinsic (such as distribution areas), cannot be considered as actually heritable. It is argued that we should better care for the precise definition and properties of characters of interest than decide a priori to include them in any case in the analysis. The symmetrical claim of de Queiroz (1996, Am. Nat. 148, 700,708) that some characters of interest should better be excluded from analyses to reconstruct their history is similarly inaccurate. If they match the logical principles of phylogenetic analysis, there is no acceptable reason to exclude them. The different statistical testing strategies of Zrzavý (1997) and de Queiroz (1996) aimed at justifying inclusion versus exclusion of characters are ill-conceived, leading respectively to Type II and Type I errors. It is argued that phylogenetic analyses should not be constrained by testing strategies that are downstream of the logical principles of phylogenetics. Excluding characters and mapping them on an independent phylogeny produces a particular and suboptimal kind of secondary homology, the use of which can be justified only for preliminary studies dealing with broadly defined characters. [source]