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Outer Part (outer + part)
Selected AbstractsMechanisms determining cell membrane expression of different ,, TCR chain pairingsEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 7 2009Laurent Boucontet Abstract We investigated the ability of the most common TCR-, and , chains to express on the cell surface. V,1C,4 and V,7C,1 chains paired with all TCR-, chains tested, whereas V,4C,1 chains were found with V,4 and V,5, but not with V,2 or V,6 chains, and V,2C,2 chains were expressed only with V,5. Mapping studies showed that up to four polymorphic residues influence the different co-expressions of V,1 and V,2 chains with V, chains. Unexpectedly, these residues are not located in the canonical ,/, interface, but in the outer part of the ,, TCR complex exposed to the solvent. Expression of functional V,4 or V,6 chains in V,2/V,5+ cells or of functional V,2C,2 in V,1+ cells reduced cell-surface expression of the ,, TCR. Taken together, these data show that (i) the V,/V, repertoire of mouse ,, T cells is reduced by physical constraints in their associations. (ii) Lack of V,2/V, expression is due to the formation of aberrant TCR complexes, rather than to an intrinsic inability of the chains to pair and (iii) despite not being expressed at the cell surface, the presence of a functionally rearranged V,2 chain in ,, T cells results in reduced TCR levels. [source] Synapse-specific localization of vesicular glutamate transporters in the rat olfactory bulbEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 5 2007Marie-Madeleine Gabellec Abstract Vesicular glutamate transporters (VGLUTs) mediate the packaging of the excitatory neurotransmitter glutamate into synaptic vesicles. Three VGLUT subtypes have so far been identified, with distinct expression patterns in the adult brain. Here, we investigated the spatial distribution of the three VGLUTs in the rat olfactory bulb, a brain region containing a variety of glutamate synapses, both axodendritic and dendrodendritic. Using multilabelling confocal microscopy and electron microscopic immunocytochemistry, we showed that each VGLUT isoform has a highly selective localization in olfactory bulb synapses. VGLUT1 is present at dendrodendritic synapses established by the output neurones (mitral and tufted cells) with bulbar interneurones in the glomerular layer and external plexiform layer, as well as in axonal synapses of the granule cell layer. By contrast, VGLUT2 is strongly expressed in axon terminals of olfactory sensory neurones, which establish synapses with second-order neurones in the glomerular neuropil. VGLUT2 is also found in the outer part of the external plexiform layer and in the granule cell layer but colocalizes only partially with VGLUT1. Finally, we showed that VGLUT3 is exclusively located in the glomerular neuropil, where it colocalizes extensively with the vesicular inhibitory amino acid transporter vesicular GABA transporter, suggesting that it is associated with a subset of inhibitory synapses. Together, these observations extend previous findings on VGLUT distribution in the forebrain, and suggest that each VGLUT subtype has a specific function in the distinct features of axodendritic and dendrodendritic synapses that characterize the olfactory bulb circuit. [source] Ecology and microbial structures of archaeal/bacterial strings-of-pearls communities and archaeal relatives thriving in cold sulfidic springsFEMS MICROBIOLOGY ECOLOGY, Issue 1 2004Christian Rudolph Abstract Recently, a unique microbial community, growing in a whitish, macroscopically visible strings-of-pearls-like structure was discovered in the cold, sulfidic marsh water of the Sippenauer Moor near Regensburg, Bavaria, Germany. The pearls interior is predominated by microcolonies of the non-methanogenic SM1 euryarchaeon; the outer part of the pearls is mainly composed of Thiothrix. To screen sulfidic ecosystems for the distribution of such unique microbial communities, comparative microbial and geochemical analyses of cold, sulfidic springs of three geographically distinct locations in Bavaria, Germany, and Dalyan, Turkey, were performed. Here, we report on the discovery and study of another type of strings-of-pearls revealing a new microbial community structure. While the SM1 euryarchaeon is again the predominant archaeal constituent, the bacterial partner is the so-called IMB1 ,-proteobacterium. Due to the predominance of the IMB1 ,-proteobacterium, the strings-of-pearls reveal a fluffy and greyish macroscopical appearance. The phylogenetic survey revealed SM1 euryarchaeal relatives, designated as SM1 group, in all sites studied, indicating a widespread distribution of these archaea in terrestrial ecosystems. [source] Return migration of adult Atlantic salmon, Salmo salar, in relation to water diverted through a power stationFISHERIES MANAGEMENT & ECOLOGY, Issue 1 2003E. B. Thorstad Abstract ,The migration of Atlantic salmon, Salmo salar L., returning to the River Suldalslågen, Norway, was studied in relation to redirection of freshwater flow through a power station. The outlet of the power station is situated in the Hylsfjord, a fjord adjacent to the river mouth. Seventy-two salmon were tagged with acoustic transmitters, released in the outer part of the fjord system and automatically recorded when entering the Hylsfjord or the river. Data were collected during one period when the power station was running and two periods when the power station was closed. The release of water from the power station did not greatly attract the salmon during their return migration. Proportions of salmon entering the river or time from release to entering the river did not differ among salmon tagged in the different periods. The salmon were recorded in the Hylsfjord both when the power station was running and closed and there were no differences in number of times, number of days or hours recorded in the Hylsfjord among salmon tagged in the three periods. The only significant difference found among periods was duration of continuous stays in the inner part of the Hylsfjord. This may indicate a slight attraction to the freshwater release, but the difference seems small (1.8 vs. 0.7 h) compared with the time the fish stayed in the fjord system before entering the river (16,85 days). [source] Leg ulcers and hydroxyurea: report of three cases with essential thrombocythemiaINTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 12 2002Zeynep Demirçay MD Case 1,A 65-year-old woman with essential thrombocythemia (ET) had been taking oral hydroxyurea (HU), 1000 mg daily, for 7 years. Six months ago, she developed an ulcer on the outer part of her left ankle, which healed spontaneously within 2 months. She presented with a new, tender, shallow ulcer, 2 cm × 2 cm in size, at the same site. Doppler examination revealed thrombosis of the left common femoral vein and a calcified atheroma plaque of the left common femoral artery. The dosage of HU was decreased to 500 mg daily when the platelet counts were found to be within normal levels. The ulcer completely healed within 2 months with occlusive wound dressings, and has not recurred within the follow-up period of 1 year. Case 2,A 56-year-old women presented with multiple, painful, leg ulcers of 1 year duration. She had been diagnosed as having ET and had been on HU therapy, 1500 mg/day, for the past 5 years. Interferon-,-2b was started 3 months ago, in addition to HU, which was tapered to 1000 mg daily. She had suffered from hypertension for 20 years treated with nifedipine and enalapril, and had recently been diagnosed with diabetes mellitus which was controlled by diet. Examination revealed three ulcers located on the lateral aspects of both ankles and right distal toe. Arterial and venous Doppler examinations were within normal limits. Histopathology of the ulcer revealed nonspecific changes with a mixed inflammatory cell infiltrate around dermal vessels. The ulcers completely healed within 10 weeks with topical hydrocolloid dressings. After healing, she was lost to follow-up. A year later, it was learned that she had developed a new ulcer at her right heel, 3 months after her last visit (by phone call). This ulcer persisted for 8 months until HU was withdrawn. Case 3,A 64-year-old woman with ET presented with a painful leg ulcer of 6 months' duration. She had been taking oral HU for 5 years. She had a 20-year history of hypertension treated with lisinopril. Examination revealed a punched-out ulcer of 2 cm × 2 cm over the right lateral malleolus (Fig. 1). Doppler examination of the veins revealed insufficiency of the right greater saphenous and femoral veins. Angiography showed multiple stenoses of the right popliteal and femoral arteries. As her platelet count remained high, HU was continued. During the follow-up period of 13 months, the ulcer showed only partial improvement with local wound care. Figure 1. Punched-out ulcer surrounded by an erythematous border over the right malleolus (Case 3) [source] Spinel,cordierite symplectites replacing andalusite: evidence for melt-assisted diapirism in the Bushveld Complex, South AfricaJOURNAL OF METAMORPHIC GEOLOGY, Issue 6 2004T. Johnson Abstract Spinel,cordierite symplectites partially replacing andalusite occur in metapelitic rocks within the cores of several country rock diapirs that have ascended into the upper levels of layered mafic/ultramafic rocks in the Bushveld Complex. We investigate the petrogenesis of these symplectites in one of these diapirs, the Phepane dome. Petrographic evidence indicates that at conditions immediately below the solidus the rocks were characterized by a cordierite-, biotite- and K-feldspar-rich matrix and 5,10 mm long andalusite porphyroblasts surrounded by biotite-rich fringes. Phase relations in the MnNCKFMASHT model system constrain the near-solidus prograde path to around 3 kbar and imply that andalusite persisted metastably into the sillimanite + melt field, where the fringing relationship between biotite and andalusite provided spatially restricted equilibrium domains with silica-deficient effective bulk compositions that focused suprasolidus reaction. MnNCKFMASHT pseudosections that model these compositional domains suggest that volatile phase-absent melting reactions consuming andalusite and biotite initially produced a moat of cordierite surrounding andalusite; reaction progressed until all quartz was consumed. Spinel is predicted to grow with cordierite at around 720 °C. Formation of the aluminous solid products was strongly controlled by the receding edge of andalusite grains, with symplectites forming at the andalusite-cordierite moat interface. Decompression due to melt-assisted diapiric rise of the floor rocks into the overlying mafic/ultramafic rocks occurred close to the thermal peak. Re-crossing of the solidus at P = 1.5,2 kbar, T > 700 °C resulted in preservation of the symplectites. Two features of the silica-deficient domains inhibited resorption of spinel. First, the cordierite moat armoured the symplectites from reaction with crystallizing melt in the outer part of the pseudomorphs. Second, an up- T step in the solidus at low- P, which may be in excess of 100 °C higher than the quartz-saturated solidus, resulted in high- T crystallization of melt on decompression. Even in metapelitic rocks where melt is retained, preservation of spinel is favoured by decompression. [source] Interaction of a ,-sheet breaker peptide with lipid membranesJOURNAL OF PEPTIDE SCIENCE, Issue 2 2010Giuseppe Vitiello Abstract Aggregation of ,-amyloid peptides into senile plaques has been identified as one of the hallmarks of Alzheimer's disease. An attractive therapeutic strategy for Alzheimer's disease is the inhibition of the soluble ,-amyloid aggregation using synthetic ,-sheet breaker peptides that are capable of binding A, but are unable to become part of a ,-sheet structure. As the early stages of the A, aggregation process are supposed to occur close to the neuronal membrane, it is strategic to define the ,-sheet breaker peptide positioning with respect to lipid bilayers. In this work, we have focused on the interaction between the ,-sheet breaker peptide acetyl-LPFFD-amide, iA,5p, and lipid membranes, studied by ESR spectroscopy, using either peptides alternatively labeled at the C- and at the N-terminus or phospholipids spin-labeled in different positions of the acyl chain. Our results show that iA,5p interacts directly with membranes formed by the zwitterionic phospholipid dioleoyl phosphatidylcholine and this interaction is modulated by inclusion of cholesterol in the lipid bilayer formulation, in terms of both peptide partition coefficient and the solubilization site. In particular, cholesterol decreases the peptide partition coefficient between the membrane and the aqueous medium. Moreover, in the absence of cholesterol, iA,5p is located between the outer part of the hydrophobic core and the external hydrophilic layer of the membrane, while in the presence of cholesterol it penetrates more deeply into the lipid bilayer. Copyright © 2010 European Peptide Society and John Wiley & Sons, Ltd. [source] Vapor-condensed phase processes in the early solar systemMETEORITICS & PLANETARY SCIENCE, Issue 1 2010Lawrence GROSSMAN Many refractory inclusions in CM2 chondrites contain a relatively SiO2 -poor assemblage (spinel, hibonite, grossite, perovskite, corundum) that represents a high-temperature stage of condensation, and some may be pristine condensates that escaped later melting. Compact Type A and Type B refractory inclusions, consisting of spinel, melilite, perovskite, Ca-rich clinopyroxene ± anorthite, in CV3 chondrites are more SiO2 -rich and equilibrated with the solar nebular gas at a slightly lower temperature. Textures of many of these objects indicate that they underwent melting after condensation, crystallizing into the same phase assemblage as their precursors. The Ti3+/Ti4+ ratio of their pyroxene indicates that this process occurred in a gas whose oxygen fugacity () was approximately 8.5 log units below that of the iron-wüstite buffer, making them the only objects in chondrites known to have formed in a system whose composition was close to that of the sun. Relative to CI chondrites, these inclusions are uniformly enriched in a group of elements (e.g., Ca, REE, Zr, Ta, Ir) that are chemically diverse except for their high condensation temperatures in a system of solar composition. The enrichment factor, 17.5, can be interpreted to mean that these objects represent either the first 5.7 wt% of the condensable matter to condense during nebular cooling or the residue after vaporization of 94.3% of a CI chondrite precursor. The Mg and Si isotopic compositions of Types A and B inclusions are mass-fractionated by up to 10 and 4 ,/amu, respectively. When interpreted in terms of Rayleigh fractionation during evaporation of Mg and Si from the inclusions while they were molten, the isotopic compositions imply that up to 60% of the Mg and up to 25% of the Si were evaporated, and that approximately 80% of the enrichment in refractory (CaO+Al2O3) relative to more volatile (MgO+SiO2) in the average inclusion is due to initial condensation and approximately 20% due to subsequent evaporation. The mineralogical composition, including the Ti3+/Ti4+ ratio of the pyroxene, in Inti, a particle sampled from Comet Wild 2 by the Stardust spacecraft, is nearly identical to that of a Type B inclusion, indicating that comets contain not only the lowest-temperature condensates in the form of ices but the highest-temperature condensates as well. The FeO/(FeO+MgO) ratios of olivine and pyroxene in the matrix and chondrules of carbonaceous and ordinary chondrites are too high to be made in a system of solar composition, requiring s only 1 or 2 log units below iron-wüstite, more than 105 times higher than that of a solar gas. Various ways have been devised to generate cosmic gases sufficiently oxidizing to stabilize significant FeO in olivine at temperatures above those where Fe-Mg interdiffusion in olivine ceases. One is by vertical settling of dust toward the nebular midplane, enriching a region in dust relative to gas. Because dust is enriched in oxygen compared to carbon and hydrogen relative to solar composition, a higher results from total vaporization of the region, but the factor by which theoretical models have so far enriched the dust is 10 times too low. Another is by transporting icy bodies from the outer part of the nebula into the hot, inner part where vaporization of water ice occurs. Not only does this method fail to make the needed by a factor of 30,1000 but it also ignores simultaneous evaporation of carbon-bearing ices that would make the even lower. [source] The effect of a finite mass reservoir on the collapse of spherical isothermal clouds and the evolution of protostellar accretionMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 2 2005E. I. Vorobyov ABSTRACT Motivated by recent observations that detect an outer boundary for starless cores, and evidence for time-dependent mass accretion in the Class 0 and Class I protostellar phases, we re-examine the case of spherical isothermal collapse in the case of a finite mass reservoir. The presence of a core boundary, implemented through a constant-volume approximation in our simulation, results in the generation of an inward-propagating rarefaction wave. This steepens the gas density profile from r,2 (self-similar value) to r,3 or steeper. After a protostar forms, the mass accretion rate evolves through three distinct phases: (1) an early phase of decline in , which is a non-self-similar effect due to rapid and spatially non-uniform infall in the pre-stellar phase; (2) for large cores, an intermediate phase of near-constant from the infall of the outer part of the self-similar density profile, which has low (subsonic) infall speed in the pre-stellar phase; and (3) a late phase of rapid decline in when accretion occurs from the region affected by the inward-propagating rarefaction wave. Our model clouds of small to intermediate size make a direct transition from phase (1) to phase (3) above. Both the first and second phase (if the latter is indeed present) are characterized by a temporally increasing bolometric luminosity Lbol, while Lbol is decreasing in the third (final) phase. We identify the period of temporally increasing Lbol with the Class 0 phase, and the later period of terminal accretion and decreasing Lbol with the Class I phase. The peak in Lbol corresponds to the evolutionary time when 50 ± 15 per cent of the cloud mass has been accreted by the protostar. This is in agreement with the classification scheme proposed in the early 1990s by André et al.; our model adds a physical context to their interpretation. We show how our results can be used to explain tracks of envelope mass Menv versus Lbol for protostars in Taurus and Ophiuchus. We also develop an analytic formalism that successfully reproduces the protostellar accretion rate from profiles of density and infall speed in the pre-stellar phase. It shows that the spatial gradient of infall speed that develops in the pre-stellar phase is a primary cause of the temporal decline in during the early phase of protostellar accretion. [source] Rigid rotation of the solar core?MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 4 2001On the reliable extraction of low-, rotational p-mode splittings from full-disc observations of the Sun We present low-, rotational p-mode splittings from the analysis of 8 yr of observations made by the Birmingham Solar-Oscillations Network (BiSON) of the full solar disc. These data are presented in the light of a thorough investigation of the fitting techniques used to extract them. Particular attention is paid to both the origin and magnitude of bias present in these estimates. An extensive Monte Carlo strategy has been adopted to facilitate this study , in all, several thousand complete, artificial proxies of the 96-month data set have been generated to test the analysis of real ,full-disc' data. These simulations allow for an assessment of any complications in the analysis which might arise from variations in the properties of the p modes over the 11-yr solar activity cycle. The use of such an extended data set affords greater precision in the splittings, and by implication the rotation rate inferred from these data, and reduces bias inherent in the analysis, thereby giving a more accurate determination of the rotation. The grand, weighted sidereal average of the BiSON set is , a value consistent with that expected were the deep radiative interior to rotate at the same frequency, and in the same ,rigid' manner, as the more precisely and accurately studied outer part of the radiative zone. [source] Formation of blue compact dwarf galaxies from merging and interacting gas-rich dwarfsMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY: LETTERS (ELECTRONIC), Issue 1 2008Kenji Bekki ABSTRACT We present the results of numerical simulations which show the formation of blue compact dwarf (BCD) galaxies from merging between very gas-rich dwarfs with extended H i gas discs. We show that dwarf,dwarf merging can trigger central starbursts and form massive compact cores dominated by young stellar populations. We also show that the pre-existing old stellar components in merger precursor dwarfs can become diffuse low surface brightness components after merging. The compact cores dominated by younger stellar populations and embedded in more diffusely distributed older ones can be morphologically classified as BCDs. Since new stars can be formed from gas transferred from the outer part of the extended gas discs of merger precursors, new stars can be very metal-poor ([Fe/H] < ,1). Owing to very high gaseous pressure exceeding 105 kB (where kB is the Boltzmann constant) during merging, compact star clusters can be formed in forming BCDs. The BCDs formed from merging can still have extended H i gas discs surrounding their blue compact cores. We discuss whether tidal interaction of gas-rich dwarfs without merging can also form BCDs. [source] Metastasis of renal cell carcinoma to central nervous system hemangioblastoma in two patients with von Hippel,Lindau diseasePATHOLOGY INTERNATIONAL, Issue 12 2001Shuji Hamazaki Here we report tumor-to-tumor metastases identified in two patients with von Hippel,Lindau (VHL) disease. The first patient had bilateral renal carcinomas and multiple cerebellar hemangioblastomas, and the second patient had a renal carcinoma and multiple hemangioblastomas in the retina, cerebellum and spinal cord. A cerebellar lesion from the first patient and a spinal lesion from the second patient contained two distinct components. The inner part of these tumors consisted of a nested mass of polygonal clear cells that expressed cytokeratin and epithelial membrane antigen, while the outer part of the tumors showed proliferation of capillaries and intervening foamy stromal cells that were negative for cytokeratin and epithelial membrane antigen. The tumors were thus considered to be hemangioblastomas complicated by metastatic lesions of renal cell carcinoma of clear cell type. These cases indicate that tumor-to-tumor metastasis should be considered when hemangioblastoma contains a clear cell carcinoma component in the setting of VHL disease, and that immunohistochemical staining for cytokeratin and epithelial membrane antigen is useful for the diagnosis. [source] Silicon deposition in the root reduces sodium uptake in rice (Oryza sativa L.) seedlings by reducing bypass flowPLANT CELL & ENVIRONMENT, Issue 10 2006H. J. GONG ABSTRACT Sodium chloride reduces the growth of rice seedlings, which accumulate excessive concentrations of sodium and chloride ions in their leaves. In this paper, we describe how silicon decreases transpirational bypass flow and ion concentrations in the xylem sap in rice (Oryza sativa L.) seedlings growing under NaCl stress. Salt (50 mM NaCl) reduced the growth of shoots and roots: adding silicate (3 mM) to the saline culture solution improved the growth of the shoots, but not roots. The improvement of shoot growth in the presence of silicate was correlated with reduced sodium concentration in the shoot. The net transport rate of Na from the root to shoot (expressed per unit of root mass) was also decreased by added silicate. There was, however, no effect of silicate on the net transport of potassium. Furthermore, in salt-stressed plants, silicate did not decrease the transpiration, and even increased it in seedlings pre-treated with silicate for 7 d prior to salt treatment, indicating that the reduction of sodium uptake by silicate was not simply through a reduction in volume flow from root to shoot. Experiments using trisodium-8-hydroxy-1,3,6-pyrenetrisulphonic acid (PTS), an apoplastic tracer, showed that silicate dramatically decreased transpirational bypass flow in rice (from about 4.2 to 0.8%), while the apparent sodium concentration in the xylem, which was estimated indirectly from the flux data, decreased from 6.2 to 2.8 mM. Direct measurements of the concentration of sodium in xylem sap sampled using Philaenus spumarius confirmed that the apparent reduction was not a consequence of sodium recycling. X-ray microanalysis showed that silicon was deposited in the outer part of the root and in the endodermis, being more obvious in the latter than in the former. The results suggest that silicon deposition in the exodermis and endodermis reduced sodium uptake in rice (Oryza sativa L.) seedlings under NaCl stress through a reduction in apoplastic transport across the root. [source] Histological Structure of the Adrenal Gland of the Bottlenose Dolphin (Tursiops truncatus) and the Striped Dolphin (Stenella coeruleoalba) from the Adriatic SeaANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 1 2010S. Vukovi Summary The structure of the adrenal gland was studied in 11 bottlenose dolphins (Tursiops truncatus), and five striped dolphins (Stenella coeruleoalba). These species are legally protected in Croatia. All examined animals died of natural causes and were found stranded along eastern Adriatic coast. In both species the adrenal gland consists of a cortex and a medulla; the cortex is divided into three zones. Whereas in the bottlenose dolphin, there is a zona arcuata which contains columnar cells arranged in the form of arches; in the striped dolphin this zone is replaced by zona glomerulosa containing rounded clusters of polygonal cells. In both species, the zona fasciculata consists of radially oriented cords of polygonal cells, whereas in zona reticularis cells are arranged in branching and anastomosing cords. The adrenal medulla in both species contains dark, epinephrine-secreting cells and light norepinephrine-secreting cells. Epinephrine-secreting cells are localized in the outer part of the medulla, whereas norepinephrine-secreting cells are found in the inner part, arranged in clusters and surrounded by septa of thin connective tissue. The gland is surrounded by a thick connective-tissue capsule, from where thick trabeculae extend towards the interior. In the bottlenose dolphin, group of cells resembling both medullar and cortical cells can be seen within the capsule; whereas only groups of cells resembling cortical cells are found within the capsule of the striped dolphin. In the bottlenose dolphin invagination of the adrenal cortex into the medulla is obvious as well as medullary protrusions extending through cortex to the connective tissue capsule. [source] An interpretation of rapid changes in the magnetic field associated with solar flaresASTRONOMISCHE NACHRICHTEN, Issue 8 2008I.V. Oreshina Abstract The energy source of a flare is the magnetic field in the corona. A topological model of the magnetic field is used here for interpreting the recently discovered drastic changes in magnetic field associated with solar flares. The following observational results are self-consistently explained: (1) the transverse field strength decreases at outer part of active regions and increases significantly in their centers; (2) the center-of-mass positions of opposite magnetic polarities converge towards the magnetic neutral line just after flares onset; (3) the magnetic flux of active regions decreases steadily during the course of flares. For X-class flares, almost 50% events show such changes. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] 4362: Iodine-125 orbital irradiation : improvement of cosmetic results for patients needing postenucleation irradiationACTA OPHTHALMOLOGICA, Issue 2010C LEVY-GABRIEL Purpose Patients enucleated for malignant intraocular tumors (as retinoblastoma or uveal melanoma) that have extrascleral extension and/or optic nerve resection margin involvement, are at risk of orbital recurrence. These enucleated orbits were previously treated with external beam radiotherapy which induced late sequelae, in particular facial atrophy. Iodine 125 Orbital brachytherapy (BRT) was first realised in 1983 in South Africa as a technique to irradiate the content of the orbit while minimizing the dose to the surrounding bone and eyelids. We report our experience since 2000 with this technique Methods Six nylon tubes containing 125 I seeds were implanted though the eyelids around the periphery of the orbit. Each contained a metal gutter that screened the outer part of the seeds from the bony orbit. A seventh unscreened tube was placed in the center and a golden plaque with 125 I seeds on its inner surface was secured beneath the eyelid. The reference dose around the target was 45 Gy for retinoblastoma and 60 Gy for uveal melanoma Results Since 2000 13 patients underwent BRT : 9 retinoblastomas (median follow up 36 months, 1 child died of craniospinal metastasis), 3 uveal melanomas (median follow up 55 months, 1 patient developed a metastatic disease), and 1 medulloepithelioma (median follow up 45 months). No patient developed orbital recurrence after BRT. Regarding cosmesis, results were much more acceptable than with other forms of irradiation with a normal size prothesis adaptation Conclusion 125 I orbital brachytherapy is an effective method of irradiating the orbit to prevent recurrent tumor after enucleation with better cosmesis results than with other forms of irradiation, especially in case of children Commercial interest [source] Age-Related Microhabitat Segregation in Willow Tit Parus montanus Winter FlocksETHOLOGY, Issue 11 2000Lluís Brotons It is expected that through flexibility in behaviour, flock living birds respond to the asymmetries in resource access derived from dominance relationships. We analysed the microhabitat use of willow tits in winter flocks and assessed possible factors which shape habitat segregation between adults and juveniles in different temperature regimes. When foraging in mild conditions (ambient temperature >,0°C), flocks split up into subgroups with adults foraging in inner parts of trees more often than juveniles. However, no differences were recorded in the vertical position occupied in trees. In harsh conditions (< , 4°C), flocks re-united and juveniles further moved to outer parts of trees, increasing horizontal segregation between age classes. In mild conditions, vigilance behaviour was not related to the position of birds in trees, but in harsh conditions, scanning frequency was higher in outer parts of trees only for adults. In mild weather, juvenile position in trees was associated with body size and mass. The foraging microhabitat segregation detected in harsh conditions fits the age-related hoarding distribution previously described in the same population. This supports the hypothesis that hoarded food is important in determining future foraging habitat use. Adult preference and intraspecific competition for safer or richer inner parts of trees as foraging sites during harsh conditions seems to determine the habitat segregation between adults and juveniles. Furthermore, we suggest that in mild weather, when foraging in the absence of adults, juveniles balance the costs of using a potentially dangerous microhabitat with the benefits of building energetically cheap and large food reserves through hoarding. The expected patterns of microhabitat segregation may differ in parids, depending on whether predation risk or other factors such as food availability are the main factors controlling habitat quality. [source] Characterizing organic matter of soil aggregate coatings and biopores by Fourier transform infrared spectroscopyEUROPEAN JOURNAL OF SOIL SCIENCE, Issue 2 2004R. H. Ellerbrock Summary In some soils, aggregate coatings and walls of biopores differ in the content of clay and organic carbon from that of the aggregate interiors or the soil matrix. The composition of the organic matter on aggregates and on the surfaces of biopores is largely unknown. We have compared the composition of organic matter between inner and outer parts of aggregates and between biopore walls and the soil matrix in a loamy arable soil and a sandy forest one. Hot-water- and sodium-pyrophosphate-extractable organic matter was analysed by Fourier transform infrared (FT-IR) spectroscopy. For the sandy forest soil, the FT-IR spectra showed that organic matter from the walls of root channels contains fewer functional groups with absorption bands at 1740,1710 cm,1 and 1640,1600 cm,1 than that from burrow fillings. For the arable soil, the content of these functional groups in hot-water-soluble organic matter from the coatings is less than in that from the interiors in the topsoil, and the reverse is so in the subsoil, probably because water-soluble organic matter containing these functional groups has moved from topsoil to subsoil. The results indicate that root channels in the forest soil have more reactive zones in an otherwise relatively inert sandy matrix, whereas aggregate coatings in the arable subsoil have a greater cation exchange capacity and a greater sorption potential for hydrophobic substances than the aggregate interiors. [source] Test of flow field on the annular meridian plane in a tubular membrane separator with rotary tangential flowJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 9 2004Cheng Duan Wang Abstract Enhancement of membrane microfiltration by rotary tangential flow is a new technique, which is based on the hydrocyclone mechanism. It improved the structure of the general membrane separator and the form of the liquid suspension flowing into the separator, so as to increase membrane fluxes and decrease membrane fouling. In our research, a tubular membrane separator with rotary tangential flow was designed for the first time. The flow field characteristics of polypropylene tubular membrane microfiltration in this tubular separator were studied systematically by means of the Particle Image Velocimetry (PIV) test. Streamlines and velocity distributions of the meridian plane of the separator under different operating parameters were obtained. The velocity distribution characteristics of rotary circular tangential flow were analyzed quantitatively with the following conclusions being obtained: (1)In the non-vortex area, no matter how the operating parameters (flux, entry pressure) change, the velocity near the rotary tangential flow entrance is higher than the velocity far from the entrance at the same radial coordinates. In the vortex area, generally the flow velocity of the inner vortex is lower than that of the outer vortex. At the vortex center, the velocity is the lowest, the radial velocity being generally equal to zero. In the vortex zone, the radial velocity is less than the axial velocity. (2)Under test conditions, the radial velocity and the axial velocity of the vortexes' borders are 1,2 times the average axial velocity in the annular gap of the membrane module. The maximum radial velocity and axial velocity of Taylor vortexes are 2,5 times the average axial velocity in the annular gap of the membrane module. (3)In the vortexes that formed on the meridian plane, it was found that mass transfer occurred between the inner and outer parts of the fluid. Much fluid moved from the outer vortexes into the inner ones, which was able to prevent particles blocking the membrane tube. Copyright © 2004 Society of Chemical Industry [source] Tastier and Healthier Alternatives to French FriesJOURNAL OF FOOD SCIENCE, Issue 4 2010Caius M. Rommens ABSTRACT:, The effect of both the origin and shape of potato cuts on fry quality was investigated in this study. Linear strips from the inner core of tubers were compared to those from outer tissues, both before and after processing, and strips from either specific tissues or whole peeled tubers were also evaluated against ring-shaped cuts. Both strips and rings had 0.7 cm sides and, in most cases, a volume of 4.9 cm3. They were analyzed for moisture content, antioxidants, asparagine, and reducing sugars. The material was then blanched, dipped in 0.5% disodium acid pyrophosphate and 0.3% glucose, dried at 77 °C, par-fried in soybean oil at 191 °C, and finish-fried at 168 °C. The fried product was analyzed for sensory characteristics and oil, salt, and acrylamide content. Our results showed that strips from the inner core absorbed 28% more oil and exhibited inferior sensory characteristics compared to strips from the outer parts. The extended drying and frying times needed to match the crispness and flavor of inner strips to those of regularly fried outer strips resulted in a further increased absorption of oil and, importantly, triggered a 163% increase in levels of the toxic Maillard reaction product acrylamide. Potato rings consisted of higher dry matter material, contained more antioxidants, and had a lower surface-to-volume ratio than the conventional linear strips. Upon processing, they also absorbed 22% less oil, contained 26% less salt, and displayed superior sensory properties. Thus, ring fries may represent an attractive alternative to French fries as processed staple food. [source] Two stage growth of microdiamond in UHP dolomite marble from Kokchetav Massif, KazakhstanJOURNAL OF METAMORPHIC GEOLOGY, Issue 6 2003H. Ishida Abstract The abundance and morphology of microdiamond in dolomite marble from Kumdy-kol in the Kokchetav Massif, are unusual; a previous study estimated the maximum content of diamonds in dolomite marble to be about 2700 carat ton,1. Microdiamond is included primarily in garnet, and occasionally in diopside and phlogopite pseudomorphs after garnet. They are classified into three types on the basis of their morphology: (1) S-type: star-shaped diamond consisting of translucent cores and transparent subhedral to euhedral very fine-grained outer parts; (2) R-type: translucent crystals with rugged surfaces; and (3) T-type: transparent, very fine-grained crystals. The S-type is the most abundant. Micro-Laue diffraction using a 1.6-µm X-ray beam-size demonstrated that the cores of the star-shaped microdiamond represent single crystals. In contrast, the most fine-grained outer parts usually have different orientations compared to the core. Laser,Raman studies indicate that the FWHM (Full Width at Half Maximum) of the Raman band of the core of the S-type diamond is slightly larger than that for the outer parts. Differences in morphology, crystal orientations, and in the FWHM of the Raman band between the core and the fine-grained outer-parts of S-type microdiamond suggest that the star-shaped microdiamond was formed discontinuously in two distinct stages. [source] The shape of an accretion disc in a misaligned black hole binaryMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 1 2009Rebecca G. Martin ABSTRACT We model the overall shape of an accretion disc in a semidetached binary system in which mass is transferred on to a spinning black hole the spin axis of which is misaligned with the orbital rotation axis. We assume the disc is in a steady state. Its outer regions are subject to differential precession caused by tidal torques of the companion star. These tend to align the outer parts of the disc with the orbital plane. Its inner regions are subject to differential precession caused by the Lense,Thirring effect. These tend to align the inner parts of the disc with the spin of the black hole. We give full numerical solutions for the shape of the disc for some particular disc parameters. We then show how an analytic approximation to these solutions can be obtained for the case when the disc surface density varies as a power law with radius. These analytic solutions for the shape of the disc are reasonably accurate even for large misalignments and can be simply applied for general disc parameters. They are particularly useful when the numerical solutions would be slow. [source] The stellar population content of the thick disc and halo of the Milky Way analogue NGC 891MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 3 2009M. Rejkuba ABSTRACT We present deep VI images obtained with the Advanced Camera for Surveys on board the Hubble Space Telescope, covering three fields in the north-east side of the edge-on disc galaxy NGC 891. The observed fields span a wide range of galactocentric distances along the eastern minor axis, extending from the plane of the disc to 12 kpc, and out to ,25 kpc along the major axis. The photometry of individual stars reaches ,2.5 mag below the tip of the red giant branch. We use the astrophotometric catalogue to probe the stellar content and metallicity distribution across the thick disc and spheroid of NGC 891. The colour,magnitude diagrams of thick disc and spheroid population are dominated by old red giant branch stars with a wide range of metallicities, from the sparsely populated metal-poor tail at [Fe/H],,2.4 dex, up to about half-solar metallicity. The peak of the metallicity distribution function of the thick disc is at ,0.9 dex. The inner parts of the thick disc, within ,14 kpc along the major axis show no vertical colour/metallicity gradient. In the outer parts, a mild vertical gradient of ,(V,I)0/,|Z| = 0.1 ± 0.05 kpc,1 or less than 0.1 dex kpc,1 is detected, with bluer colours or more metal-poor stars at larger distances from the plane. This gradient is, however, accounted for by the mixing with the metal-poor halo stars. No metallicity gradient along the major axis is present for thick-disc stars, but strong variations of about 0.35 dex around the mean of [Fe/H]=,1.13 dex are found. The properties of the asymmetric metallicity distribution functions of the thick-disc stars show no significant changes in both the radial and the vertical directions. The stellar populations situated within the solar-cylinder-like distances show strikingly different properties from those of the Galaxy populating similar distances. This suggests that the accretion histories of both galaxies have been different. The spheroid population, composed of the inner spheroid and the halo, shows remarkably uniform stellar population properties. The median metallicity of the halo stellar population shows a shallow gradient from about ,1.15 dex in the inner parts to ,1.27 dex at 24 kpc distance from the centre, corresponding to ,13reff. Similar to the thick-disc stars, large variations around the mean relation are present. [source] The properties of the heterogeneous Shakhbazyan groups of galaxies in the SDSSMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 2 2009D. Capozzi ABSTRACT We present a systematic study of the subsample of Shakhbazyan (SHK) groups covered by the Sloan Digital Sky Survey Data Release 5 (SDSS DR5). SHK groups probe an environment with characteristics which are intermediate between those of loose and very compact groups. Surprisingly, we found that several groups identifying algorithms, e.g. Berlind et al. and Tago et al., miss this type of structures. Using the SDSS DR5 spectroscopic data and the photometric redshifts derived in D'Abrusco et al., we identified possible group members in photometric redshift space and derived, for each group, several individual properties (richness, size, mean photometric redshift, fraction of red galaxies, etc.). We also combined pointed and stacked Rosat All Sky Survey (RASS) data to investigate the X-ray luminosities of these systems. Our study confirms that the majority of groups are physical entities with richness in the range 3,13 galaxies, and properties ranging between those of loose and compact groups. We confirm that SHK groups are richer in early-type galaxies than the surrounding environment and the field, as expected from the morphology,density relation and from the selection of groups of red galaxies. Furthermore, our work supports the existence of two subclasses of structures, the first one being formed by compact and isolated groups and the second formed by extended structures. We suggest that while the first class of objects dwells in less dense regions like the outer parts of clusters or the field, possibly sharing the properties of Hickson Compact Groups, the more extended structures represent a mixture of [core + halo] configurations and cores of rich clusters. X-ray luminosities for SHK groups are generally consistent with these results and with the expectations for the LX,,v relation, but also suggest the velocity dispersions reported in literature are underestimated for some of the richest systems. [source] A deep kinematic survey of planetary nebulae in the Andromeda galaxy using the Planetary Nebula SpectrographMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 1 2006H. R. Merrett ABSTRACT We present a catalogue of positions, magnitudes and velocities for 3300 emission-line objects found by the Planetary Nebula Spectrograph in a survey of the Andromeda galaxy, M31. Of these objects, 2615 are found likely to be planetary nebulae (PNe) associated with M31. The survey area covers the whole of M31's disc out to a radius of . Beyond this radius, observations have been made along the major and minor axes, and the Northern Spur and Southern Stream regions. The calibrated data have been checked for internal consistency and compared with other catalogues. With the exception of the very central, high surface brightness region of M31, this survey is complete to a magnitude limit of m5007, 23.75, 3.5 mag into the PN luminosity function. We have identified emission-line objects associated with M31's satellites and other background galaxies. We have examined the data from the region tentatively identified as a new satellite galaxy, Andromeda VIII, comparing it to data in the other quadrants of the galaxy. We find that the PNe in this region have velocities that appear to be consistent with membership of M31 itself. The luminosity function of the surveyed PNe is well matched to the usual smooth monotonic function. The only significant spatial variation in the luminosity function occurs in the vicinity of M31's molecular ring, where the luminosities of PNe on the near side of the galaxy are systematically ,0.2 mag fainter than those on the far side. This difference can be explained naturally by a modest amount of obscuration by the ring. The absence of any difference in luminosity function between bulge and disc suggests that the sample of PNe is not strongly populated by objects whose progenitors are more massive stars. This conclusion is reinforced by the excellent agreement between the number counts of PNe and the R -band light. The number counts of kinematically selected PNe also allow us to probe the stellar distribution in M31 down to very faint limits. There is no indication of a cut-off in M31's disc out to beyond four scalelengths, and no signs of a spheroidal halo population in excess of the bulge out to 10 effective bulge radii. We have also carried out a preliminary analysis of the kinematics of the surveyed PNe. The mean streaming velocity of the M31 disc PNe is found to show a significant asymmetric drift out to large radii. Their velocity dispersion, although initially declining with radius, flattens out to a constant value in the outer parts of the galaxy. There are no indications that the disc velocity dispersion varies with PN luminosity, once again implying that the progenitors of PNe of all magnitudes form a relatively homogeneous old population. The dispersion profile and asymmetric drift results are shown to be mutually consistent, but require that the disc flares with radius if the shape of its velocity ellipsoid remains invariant. [source] Mass components in ordered and in chaotic motion in galactic N -body modelsMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 2 2002N. Voglis ABSTRACT Two self-consistent (N -body) non-rotating equilibrium models of elliptical galaxies with smooth central density profiles (called ,Q' and ,C' models) are constructed, starting from quiet and clumpy cosmological initial conditions, respectively. Both models are triaxial. The Q model has an E7 maximum ellipticity in the inner parts and tends to E6 or E5 maximum ellipticity in the outer parts. The C model has a maximum ellipticity E4 in the inner parts and tends to an E2 or E1 in the outer parts. For each model, we identify the particles moving in chaotic orbits with the Lyapunov number exceeding a particular threshold (namely, 10,2.8, in units of the inverse radial periods of the particular orbits). At energy levels in the deepest 30 per cent of the potential well, no chaotic orbits were detected in the above limit of chaoticity. In the Q model, the detected chaotic part is 32 per cent of the total mass. This part has a nearly spherical distribution. It imposes limitations on the maximum ellipticity of the system, in spite of the fact that only a part of less than about 8 per cent of the total mass moves in chaotic orbits and is able to develop chaotic diffusion within a Hubble time. In the C model, the detected chaotic part is about 26 per cent of the total mass, but only less than 2 per cent can develop chaotic diffusion within a Hubble time. These chaotic components produce surface density profiles flatter than the profiles of the rest of the mass, particularly in the Q model. The two profiles intersect at a given distance, where the overall profile forms an observable hump, especially if the surface density profiles are taken along the shortest axis of the projection. [source] | ||||||||||||||||||||||