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Sample records for distribution ultrastructural localization

  1. Transport, ultrastructural localization and distribution of chemical forms of lead in radish (Raphanus sativus L.

    Directory of Open Access Journals (Sweden)

    Yan eWang

    2015-05-01

    Full Text Available Lead (Pb, a ubiquitous but highly toxic heavy metal, is harmful to human health through various pathways including by ingestion of contaminated vegetables. Radish is a worldwide root vegetable crop with significant health and nutritional benefits. However, little is known about Pb translocation and distribution within radish plants after its uptake by the roots. In this study, Pb stress was induced using Pb(NO32 in hydroponic culture, aiming to characterize the transport, ultrastructural localization and distribution of chemical forms of Pb in different tissues of radish. The results showed that the majority of Pb (85.76–98.72% was retained in underground organs including lateral roots, root heads and taproot skins, while a small proportion of Pb was absorbed by root flesh (0.44–1.56% or transported to the shoot (1.28-14.24%. A large proportion of Pb (74.11–99.30% was integrated with undissolved Pb oxalate, protein and pectates forming Pb-phosphate complexes. Moreover, a low-Pb-accumulating line of radish showed a higher proportion of Pb in water-soluble form compared with a high-Pb-accumulating line. Subcellular distribution analysis showed that a large proportion of Pb was bound to cell wall fraction in lateral roots (71.08–80.40% and taproot skin (46.22–77.94%, while the leaves and roots had 28.36–39.37% and 27.35–46.51% of Pb stored in the soluble fraction, respectively. Furthermore, transmission electron microscopy (TEM revealed Pb precipitates in intercellular space, cell wall, plasma lemma and vacuoles. Fractionation results also showed the accumulation of Pb on the cell wall, intercellular space and vacuole, and low uptake of undissolved Pb oxalate, protein, pectates and Pb–phosphate complexes, which might be due to low transport efficiency and Pb tolerance of radish. These findings would provide insight into molecular mechanism of Pb uptake and translocation in radish and facilitate development of low

  2. Ultrastructural localization of silver in rat testis and organ distribution of radioactive silver in the rat

    DEFF Research Database (Denmark)

    Ernst, E; Rungby, J; Baatrup, E

    1992-01-01

    The deposition of silver after a single intravenous injection (2 micrograms Ag g-1 body weight) was studied in the testes of Wistar rats 24 h and 1 and 2 weeks after dosing with radiolabelled 110AgNo3 (2 micrograms Ag and 1.2 kBq g-1 body weight). Also, the temporal accumulation of silver during...... the experimental period was monitored in the blood, testes, epididymides, kidney, liver and brain. The subcellular distribution of silver within the testes was demonstrated by using the histochemical technique of autometallography. Silver was cleared rapidly from the blood. After an initial rise, concentrations...... in organs remained almost stable throughout the experimental period. Silver was especially abundant in interstitial macrophages and in the basement membrane. Deposits of silver were found in all cell types of spermatogenesis and in the lysosomes of the Sertoli cells. Udgivelsesdato: 1991-Oct...

  3. Calretinin in the entorhinal cortex of the rat: distribution, morphology, ultrastructure of neurons, and co-localization with gamma-aminobutyric acid and parvalbumin.

    Science.gov (United States)

    Wouterlood, F G; van Denderen, J C; van Haeften, T; Witter, M P

    2000-09-18

    Calretinin is a marker that differentially labels neurons in the central nervous system. We used this marker to distinguish subtypes of neurons within the general population of neurons in the entorhinal cortex of the rat. The distribution, morphology, and ultrastructure of calretinin-immunopositive neurons in this cortical area were documented. We further analyzed the co-localization of the marker with gamma-aminobutyric acid (GABA) and studied whether calretinin-positive neurons project to the hippocampal formation. Methods used included single-label immunocytochemistry at the light and electron microscopic level, retrograde tracing combined with immunocytochemistry, and double-label confocal laser scanning microscopy (CLSM). The entorhinal cortex contained calretinin-positive cells in a scattered fashion, in all layers except layer IV (lamina dissecans). Bipolar and multipolar dendritic configurations were present, displaying smooth dendrites. Bipolar cells had a uniform morphology whereas the multipolar calretinin cell population consisted of large neurons, cells with long ascending dendrites, horizontally oriented neurons, and small spherical cells. Retrograde tracing combined with immunocytochemistry showed that calretinin is not present in cells projecting to the hippocampus. Few synapic contacts between calretinin-positive axon terminals and immunopositive cell bodies and dendrites were seen. Most axon terminals of calretinin fibers formed asymmetrical synapses, and immunopositive axons were always unmyelinated. Results obtained in the CLSM indicate that calretinin co-exists in only 18-20% of the GABAergic cell population (mostly small spherical and bipolar cells). Thus, the entorhinal cortex contains two classes of calretinin interneurons: GABA positive and GABA negative. The first class is presumably a classical, GABAergic inhibitory interneuron. The finding of calretinin-immunoreactive axon terminals with asymmetrical synapses suggests that the second

  4. Ultrastructural localization of acid phosphatase in nonhuman primate vaginal epithelium.

    Science.gov (United States)

    King, B F

    1985-01-01

    The vagina of the rhesus monkey is lined by a stratified squamous epithelium. However, little is known regarding the cytochemical composition of its cell organelles and the substances found in the intercellular spaces. In this study we have examined the ultrastructural distribution of acid phosphatase in the vaginal epithelium. In basal and parabasal cells reaction product was found in some Golgi cisternae and vesicles and in a variety of cytoplasmic granules. Reaction product was also found in some, but not all, membrane-coating granules. In the upper layers of the epithelium, the membrane-coating granules extruded their contents and acid phosphatase was localized in the intercellular spaces. The possible roles of acid phosphatase in keratinization, desquamation, or modification of substances in the intercellular compartment are discussed.

  5. Ultrastructural localization of intravenously injected carbon nanohorns in tumor

    Directory of Open Access Journals (Sweden)

    Matsumura S

    2014-07-01

    Full Text Available Sachiko Matsumura,1 Ryota Yuge,2 Shigeo Sato,3 Akihiro Tomida,3 Toshinari Ichihashi,2 Hiroshi Irie,4 Sumio Iijima,2,5,6 Kiyotaka Shiba,1 Masako Yudasaka6 1Cancer Institute, Japanese Foundation for Cancer Research, Tokyo, Japan; 2Smart Energy Research Laboratories, NEC Corporation, Tsukuba, Japan; 3Cancer Chemotherapy Center, Japanese Foundation for Cancer Research, Koto-ku, Tokyo, Japan; 4Teikyo University School of Medicine, Tokyo, Japan; 5Faculty of Science and Technology, Meijo University, Tenpaku, Nagoya, Japan; 6Nanotube Research Center, National Institute of Advanced Industrial Science and Technology, Higashi, Tsukuba, Japan Abstract: Nanocarbons have many potential medical applications. Drug delivery, diagnostic imaging, and photohyperthermia therapy, especially in the treatment of tumors, have attracted interest. For the further advancement of these application studies, the microscopic localization of nanocarbons in tumor tissues and cells is a prerequisite. In this study, carbon nanohorns (CNHs with sizes of about 100 nm were intravenously injected into mice having subcutaneously transplanted tumors, and the CNHs in tumor tissue were observed with optical and electron microscopy. In the tumor tissue, the CNHs were found in macrophages and endothelial cells within the blood vessels. Few CNHs were found in tumor cells or in the region away from blood vessels, suggesting that, under these study conditions, the enhanced permeability of tumor blood vessels was not effective for the movement of CNHs through the vessel walls. The CNHs in normal skin tissue were similarly observed. The extravasation of CNHs was not so obvious in tumor but was easily found in normal skin, which was probably due to their vessel wall structure difference. Proper understanding of the location of CNHs in tissues is helpful in the development of the medical uses of CNHs. Keywords: ultrastructural localization, carbon nanohorn, tumor, in vivo, extravasation

  6. Ultrastructural immunocytochemical localization of chondroitin sulfate proteoglycan in Bruch's membrane of the rat

    DEFF Research Database (Denmark)

    Lin, W L; Essner, E; McCarthy, K J

    1992-01-01

    Two monoclonal antibodies (Mab 4D5 and 2D6) raised against the core protein of a basement membrane chondroitin sulfate proteoglycan from Reichert's membrane of the rat, were used for ultrastructural immunoperoxidase localization of this protein in Bruch's membrane of the rat. Immunoreactivity for...

  7. Entactin: ultrastructural localization of an ubiquitous basement membrane glycoprotein in mouse skin

    DEFF Research Database (Denmark)

    Horiguchi, Y; Fine, J D; Ljubimov, A V;

    1989-01-01

    Entactin is a recently described sulfated glycoprotein component of mouse endodermal cell-derived extracellular matrix and is present in a number of basement membranes. It has been ultrastructurally localized to both lamina densa and adjacent epithelial cell membranes in rodent kidney. In the pre...

  8. Localization of the loosely bound nuclear proteins of rat brain: an immunocytochemical ultrastructural study.

    Science.gov (United States)

    Cocchia, D; Michetti, F

    1980-06-01

    Antibodies against the loosely bound subnuclear protein fraction (0.35 M NaCl-extractable subnuclear fraction) of rat brain were raised in rabbits, and the ultrastructural distribution of the antigenic determinants in rat cerebellum was studied using the unlabeled antibody peroxidase-antiperoxidase (PAP) method. A localization restricted to the nucleus was observed. Both neuronal and neuroglial nuclei exhibited antigens, whereas nuclei of pericytes and endothelial cells did not. The immunoreaction product was homogeneously distributed in dispersed chromatin and was absent from condensed chromatin, suggesting that the antigens were confined to the active regions of the genoma. The outer nuclear membrane and the nucleolus appeared to be free of the antigens, while a perinucleolar ring of immunoreaction was detectable. Liver preparations showed a nuclear reaction markedly weaker than the one for brain nuclei. Adsorption of the serum with isolated liver nuclei nullified the reactivity in liver tissue, whereas a sharp reaction was still observed in the cerebellum, indicating the subcellular reaction under examination to contain antigens specifically concentrated in the nervous system or unique to the brain.

  9. Histological and ultrastructural localization of antigen B in the metacestode of Taenia solium

    Energy Technology Data Exchange (ETDEWEB)

    Laclette, J.P.; Merchant, M.T.; Willms, K.

    1987-02-01

    The morphological localization of antigen B (AgB) in the tissues of the Taenia solium metacestode was studied by immunological and biochemical methods. Indirect immunofluorescence carried out on vibratome sections showed that AgB is widely distributed throughout the tissue. A more intense fluorescence was observed in the tegumentary cytons of the bladder wall and in the lumen of the spiral canal of the invaginated scolex. Ultrastructural analysis of larvae washed in PBS after dissection from meat and then incubated with rabbit antibodies against AgB, followed by peroxidase-labeled goat anti-rabbit IgG, did not exhibit electron-dense material on the external surface. Larvae fixed in glutaraldehyde immediately after dissection and exposed to the immunoperoxidase reagents did exhibit electron-dense material on microtriches, indicating that AgB is only loosely bound to the external surface. Crude extracts of surface-radioiodinated cysticerci analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) contained no labeled proteins with the molecular weight of AgB. Autoradiography of the immunoelectrophoretograms in which the crude extract was confronted with antibodies to AgB demonstrated that this antigen was not labeled, and therefore is not exposed on the tegumentary surface. The results suggest that AgB is synthesized by the tegumentary cytons of the parasite and secreted through the tegumental membrane into the host tissues and the lumen of the spiral canal.

  10. Ultrastructural localization of hair keratins, high sulfur keratin-associated proteins and sulfhydryl oxidase in the human hair.

    Science.gov (United States)

    Alibardi, Lorenzo

    2017-03-01

    Hardening of the human hair shaft during cornification results from the bonding of keratins and keratin-associated proteins. In situ hybridization and light immunocytochemical studies have shown the general distribution of different keratins and some associated proteins but not determined their ultrastructural localization. I report here the localization of hair keratins, two high-sulfur keratin-associated proteins and sulfhydryl oxidase has been studied under the transmission electron microscope in the cornification zone of the human hair. The ultrastructural study on keratin distribution in general confirms previous light microscopic studies. Sulfur-rich KAP1 is mainly cortical but the labeling disappears in fully cornified cortical cells while a diffuse labeling is also present in differentiating cuticle cells. Sulfur-rich K26 immunolocalization is only detected in the exocuticle and endocuticle. Sparse labeling for sulfhydryl oxidase occurs in differentiating cortical cells but is weak and uneven in cuticle cells and absent in medulla and inner root sheath. Labeling disappears in the upper fully cornified cortex and cuticle. The observations indicate that sulfhydryl oxidase and keratin associated proteins are initially produced in the cytoplasm among keratin bundles accumulating in cortical and cuticle cells but these proteins undergo changes during the following cornification that alter the epitopes tagged by the antibodies.

  11. Accumulation and ultrastructural distribution of copper in Elsholtzia splendens

    Institute of Scientific and Technical Information of China (English)

    PENG Hong-yun; YANG Xiao-e; TIAN Sheng-ke

    2005-01-01

    Copper accumulation and intracellular distribution in Elsholtzia splendens, a native Chinese Cu-tolerant and accumulating plant species, was investigated by transmission electron microscope (TEM) and gradient centrifugation techniques.Copper concentrations in roots, stems and leaves of E. splendens increased with increasing Cu levels in solution. After exposure to 500 μmol/L Cu for 8 d, about 1000 mg/kg Cu were accumulated in the stem and 250 mg/kg Cu in the leaf of E. splendens. At 50μmol/L Cu, no significant toxicity was observed in the chloroplast and mitochondrion within its leaf cells, but separation appeared at the cytoplasm and the cell wall within the root cells. At >250 μmol/L Cu, both root and leaf organelles in E. splendens were damaged heavily by excessive Cu in vivo. Copper subcellular localization in the plant leaf after 8 days' exposure to 500 μmol/L Cu using gradient centrifugation techniques was found to be decreased in the order: chloroplast>cell wall>soluble fraction>other organelles. The plant root cell wall was found to be the site of highest Cu localization. Increase of Cu exposure time from 8 d to 16d, increased slightly Cu concentration in cell wall fraction in roots and leaves, while that in the chloroplast fraction decreased in leaves of the plants grown in both 0.25 μmol/L and 500 μmol/L Cu. TEM confirmed that much more Cu localized in cell walls of E. splendens roots and leaves, but also more Cu localized in E. splendens' chloroplast when the plant is exposed to Cu levels>250μmol/L, as compared to those in the plant grown in 0.25 μmol/L Cu. Copper treatment at levels>250 μmol/L caused pronounced damage in the leaf chloroplast and root organelles. Copper localization in cell walls and chloroplasts could mainly account for the high detoxification of Cu in E. splendens.

  12. Ultrastructural localization of active genes in Allium cepa cells

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    By using the anti-RNA/DNA hybrid antibody as the probe, we labeled and analyzed the precise transcriptional sites of active genes in Allium cepa cells in situ. The results showed that the location of labeled signals appeared in mitochondrion was the same as that in chloroplast, generally concentrated at the central matrix space where there were no cristae and thylakoids. In the extranucleolar regions of nucleus, the labeled signals of transcriptional sites were situated at the perichromatin fibrils, which decondensed and stretched out from the chromosome territories. Our results also displayed the concentrations of labeled signals in a cer-tain region of nucleus, and this means that the gene tran-scription rich region actually existed in Allium cepa cells. In nucleolus, the synthetic sites of rRNA were localized not only to the periphery of fibrillar centers but also to the DFC near FC.

  13. Ultrastructural Localization of Adiponectin protein in Vasculature of Normal and Atherosclerotic mice

    Science.gov (United States)

    Mori, Takuya; Koyama, Yoshihisa; Maeda, Norikazu; Nakamura, Yukiko; Fujishima, Yuya; Matsuda, Keisuke; Funahashi, Tohru; Shimada, Shoichi; Shimomura, Iichiro

    2014-01-01

    Adiponectin, adipose-specific secretory protein, abundantly circulates in bloodstream and its concentration is around 1000-fold higher than that of other cytokines and hormones. Hypoadiponectinemia is a risk factor for atherosclerosis. There is little or no information on ultrastructural localization of adiponectin in the vasculature. Herein we investigated the localization of vascular adiponectin in the aorta using the immunoelectron microscopic technique. In wild-type (WT) mice, adiponectin was mainly detected on the luminal surface membrane of endothelial cells (ECs) and also found intracellularly in the endocytic vesicles of ECs. In the atherosclerotic lesions of apolipoprotein E-knockout (ApoE-KO) mice, adiponectin was detected in ECs, on the cell surface membrane of synthetic smooth muscle cells, and on the surface of monocytes adherent to ECs. Changes in adiponectin localization within the wall of the aorta may provide novel insight into the pathogenesis of atherosclerosis. PMID:24809933

  14. New, improved lanthanide-based methods for the ultrastructural localization of acid and alkaline phosphatase activity.

    Science.gov (United States)

    Halbhuber, K J; Zimmermann, N; Linss, W

    1988-01-01

    New, improved techniques for the ultrastructural localization of acid and alkaline phosphatase activity using lanthanide cations as the trapping agent were developed. Delayed penetration of the capture ions and the incubation constituents into cellular compartments was prevented by pretreating specimens with borohydride/saponin. Both the concentration of the capture agent in the incubation medium and the incubation time of the tissue specimens were optimized to achieve a satisfactory cytochemical reaction and to avoid precipitation artefacts caused by local matrix effects. The conversion of cerium phosphate into the almost insoluble cerium fluoride minimized losses of the reaction product during postincubation processing. Moreover, lanthanum itself as well as lanthanides other than cerium, e.g., gadolinium and didymium (praseodymium, neodymium), were successfully applied and can be recommended as capture agents for phosphatase cytochemistry.

  15. Local distribution and franchising rights

    Energy Technology Data Exchange (ETDEWEB)

    Penick, V. [McInnes, Cooper and Robertson, Halifax, NS (Canada); Grant, R.; McKelvey, S. [Stirling Scales, NB (Canada); Cramm, K. [Maritimes NRG, Halifax, NS (Canada)

    1998-12-31

    A summary of local distribution and franchising rights in Nova Scotia and New Brunswick is presented. The Gas Distribution Act calls for two distinct sets of regulations : broad regulations to be made by the provinces, and more technical procedural regulations to be made by the Utility and Review Board. The focus of this paper is on how municipalities will be affected by the regulations and how franchising within a local area will work. The overall objective is to ensure free competition in gas sales.

  16. Ultrastructural localization of human papilloma virus by nonradioactive in situ hybridization on tissue of human cervical intraepithelial neoplasia

    DEFF Research Database (Denmark)

    Multhaupt, H A; Rafferty, P A; Warhol, M J

    1992-01-01

    BACKGROUND: A nonradioactive in situ hybridization was developed to localize human papilloma virus (HPV) at the ultrastructural level. EXPERIMENTAL DESIGN: Cervical biopsies from human uterine cervices clinically suspicious of condyloma were embedded in Lowicryl K4M at low temperature...... confirmed the specificity of the HPV positive signals. CONCLUSIONS: This study helps define the subcellular compartmentalization of HPV DNA in infected human cells....

  17. Ultrastructural organization of muscle fiber types and their distribution in the rat superior rectus extraocular muscle.

    Science.gov (United States)

    Rashed, Rashed M; El-Alfy, Sherif H

    2012-05-01

    Extraocular muscles (EOMs) are unique as they show greater variation in anatomical and physiological properties than any other skeletal muscles. To investigate the muscle fiber types and to understand better the structure-function correlation of the extraocular muscles, the present study examined the ultrastructural characteristics of the superior rectus muscle of rat. The superior rectus muscle is organized into two layers: a central global layer of mainly large-diameter fibers and an outer C-shaped orbital layer of principally small-diameter fibers. Six morphologically distinct fiber types were identified within the superior rectus muscle. Four muscle fiber types, three single innervated fibers (SIFs) and one multiple innervated fiber (MIF), were recognized in the global layer. The single innervated fibers included red, white and intermediate fibers. They differed from one another with respect to diameter, mitochondrial size and distribution, sarcoplasmic reticulum and myofibrillar size. The orbital layer contained two distinct MIFs in addition to the red and intermediate SIFs. The orbital MIFs were categorized into low oxidative and high oxidative types according to their mitochondrial content and distribution. The highly specialized function of the superior rectus extraocular muscle is reflected in the multiplicity of its fiber types, which exhibit unique structural features. The unique ultrastructural features of the extraocular muscles and their possible relation to muscle function are discussed. Copyright © 2011 Elsevier GmbH. All rights reserved.

  18. Distribution and ultrastructure of pigment cells in the skins of normal and albino adult turbot, Scophthalmus Maximus

    Institute of Scientific and Technical Information of China (English)

    GUO Huarong; HUANG Bing; QI Fei; ZHANG Shicui

    2007-01-01

    The distribution and ultrastructure of pigment cells in skins of normal and albino adult turbots were examined with transmission electron microscopy (TEM). Three types of pigment cells of melanophore, iridophore and xanthophore have been recognized in adult turbot skins. The skin color depends mainly on the amount and distribution of melanophore and iridophore, as xanthophore is quite rare. No pigment cells can be found in the epidermis of the skins. In the pigmented ocular skin of the turbot, melanophore and iridophore are usually co-localized in the dermis. This is quite different from the distribution in larvae skin. In albino and white blind skins of adult turbots, however, only iridophore monolayer still exists, while the melanophore monolayer disappears. This cytological evidence explains why the albino adult turbot, unlike its larvae, could never resume its body color no matter what environmental and nutritional conditions were provided. Endocytosis is quite active in the cellular membrane of the iridophore. This might be related to the formation of reflective platelet and stability of the iridophore.

  19. Calcium Forms,Subcelluar Distribution and Ultrastructure of Pulp Cells as Influenced by Calcium Deficiency in Apple (Malus pumila) Fruits

    Institute of Scientific and Technical Information of China (English)

    CHEN Jian-hui; ZHOU Wei

    2004-01-01

    Calcium in Red Fuji and Starkrimson apples during storage were fractionated by sequent extracting. Localization and distribution of calcium and influence of calcium nutrition on cell ultrastructure were observed by transmission electron microscopy combined with in situ precipitation of calcium with an improved method of potassium pyroantimonate technique. Results indicated that spraying calcium solution on surface of young fruits increased contents of calcium in all forms. During storage, contents of soluble calcium and pectic calcium declined and thosein calcium phosphate, calcium oxalate and calcium silicate increased. Calcium contents of Red Fuji in all forms were higher than those of Starkrimson, indicating that calcium accumulating capability of Red Fuji fruits preceded that of Starkrimson. Under transmission electron microscopy, calcium antimonite precipitates (CaAP) was mainly distributed in cell wall, tonoplast, nuclear membrane and nucleoplasm,much more CaAP deposited in vacuole. Calcium deficiency during storage leads to decrease of CaAP in locations mentioned above, disappearance of compartmentation, and entrance of CaAP to cytoplasm. Transformation from soluble calcium and pectic calcium to calcium phosphate,oxalate and damages of biomembranes structuraly and functionally resulted from calcium deficiency during storage were the crucial causation of physiological disorder.

  20. Ultrastructure and distribution of antennal sensilla of the chilli thrips Scirtothrips dorsalis hood (Thysanoptera: Thripidae).

    Science.gov (United States)

    Zhu, Wenjing; Zhou, Shihao; Wang, Shijie; Han, Dongyin; Chen, Junyu; Fu, Yueguan

    2017-08-21

    The chilli thrips, Scirtothrips dorsalis Hood, is a serious pest of numerous important vegetable and ornamental crops. Various signals, especially phytochemical cues, determine the behavior of the phytophagous thrips at host selection. The sensory abilities of S. dorsalis are poorly understood although the antennae of adult are known to possess important sensory structures in orther insects. In this study, the morphology, distribution, and ultrastructure of the antennal sensilla of the S. dorsalis were examined by using scanning and transmission electron microscopy. Microscopy observations revealed that adult male and female S. dorsalis possess filiform antennae. Each antenna comprises a scape, a pedicel, and a flagellum composed of six segments without clear sexual dimorphism in the number and distribution of antennal sensilla. The scape and pedicel exhibit Böhm's bristles, sensilla chaetica, and sensilla campaniform. The external structures of these organs reveal their mechanosensory function. In the flagellum, the most represented sensilla are the multiporous sensilla basiconica, which can be divided into three types of single-walled olfactory sensilla; three types of sensilla chaetica with mechanosensory and gustatory functions; sensilla coeloconica, which possess hollow cuticular spoke channels and represent double-walled olfactory sensilla; sensilla capitula and sensilla cavity with thermo-hygrosensory functions; and aporous sensilla trichodea with smooth cuticula and mechanosensory function. The putative function of described sensilla is discussed in ralation to host plant selection behavior of S. dorsalis. © 2017 Wiley Periodicals, Inc.

  1. Assessment of local food distribution

    OpenAIRE

    Nordmark, Ingrid

    2015-01-01

    There is increasing interest in local food, as consumers feel confidence in such food. Local food has good opportunities to fulfil quality aspects/requirements of transparency and traceability in the supply chain due to the possibilities for direct interaction between producers and consumers. However, local food producers often face logistics challenges due to their small scale, decentralisation and integration difficulties with larger supply chains. This necessitates analysis of specific log...

  2. Local Polynomial Estimation of Distribution Functions

    Institute of Scientific and Technical Information of China (English)

    LI Yong-hong; ZENG Xia

    2007-01-01

    Under the condition that the total distribution function is continuous and bounded on (-∞,∞), we constructed estimations for distribution and hazard functions with local polynomial method, and obtained the rate of strong convergence of the estimations.

  3. Localization of Helicobacter spp. in the fundic mucosa of laboratory Beagle dogs: an ultrastructural study

    Science.gov (United States)

    2011-01-01

    In dogs Helicobacter spp. are found in all gastric regions usually localized in the surface mucus, gastric glands and parietal cells. The aim of this study was to detail the distribution of Helicobacter spp. in the fundic mucosa of asymptomatic Beagle dogs and their intracellular localization within parietal cells, in order to evaluate species-specific pathogenetic effects on gastric cells. The presence of Helicobacter spp. was investigated by immunohistochemistry, TEM, and PCR in the fundic mucosa of six Beagle dogs. Helicobacter spp. were found in all dogs examined, and H. bizzozeronii and H. felis were identified by PCR and confirmed by TEM. In the lumen of the fundic glands, co-localization was common. H. bizzozeronii was present in larger numbers than H. felis in both intraluminal and intraparietal localization. The amounts of H. bizzozeronii were similar in superficial and basal portions of the glands. H. felis was predominantly localized in the superficial portions of gastric glands but almost absent from the base. Within parietal cells, most Helicobacter organisms were intracanalicular, but intact and degenerate Helicobacter organisms were also visualized free in the cytoplasm or in secondary lysosomes. No specific degenerative lesions were found in infected parietal cells. Helicobacter organisms were also observed within macrophages in the lamina propria. In conclusion, there is a differential distribution of H. bizzozeronii and H. felis in the fundic mucosa of Beagle dogs, and their intracellular localization in parietal cells and macrophages suggests novel pathogenic scenarios for the development of immune response and maintenance of chronic gastritis in dogs. PMID:21366900

  4. Localization of Helicobacter spp. in the fundic mucosa of laboratory Beagle dogs: an ultrastructural study

    Directory of Open Access Journals (Sweden)

    Lanzoni Anna

    2011-03-01

    Full Text Available Abstract In dogs Helicobacter spp. are found in all gastric regions usually localized in the surface mucus, gastric glands and parietal cells. The aim of this study was to detail the distribution of Helicobacter spp. in the fundic mucosa of asymptomatic Beagle dogs and their intracellular localization within parietal cells, in order to evaluate species-specific pathogenetic effects on gastric cells. The presence of Helicobacter spp. was investigated by immunohistochemistry, TEM, and PCR in the fundic mucosa of six Beagle dogs. Helicobacter spp. were found in all dogs examined, and H. bizzozeronii and H. felis were identified by PCR and confirmed by TEM. In the lumen of the fundic glands, co-localization was common. H. bizzozeronii was present in larger numbers than H. felis in both intraluminal and intraparietal localization. The amounts of H. bizzozeronii were similar in superficial and basal portions of the glands. H. felis was predominantly localized in the superficial portions of gastric glands but almost absent from the base. Within parietal cells, most Helicobacter organisms were intracanalicular, but intact and degenerate Helicobacter organisms were also visualized free in the cytoplasm or in secondary lysosomes. No specific degenerative lesions were found in infected parietal cells. Helicobacter organisms were also observed within macrophages in the lamina propria. In conclusion, there is a differential distribution of H. bizzozeronii and H. felis in the fundic mucosa of Beagle dogs, and their intracellular localization in parietal cells and macrophages suggests novel pathogenic scenarios for the development of immune response and maintenance of chronic gastritis in dogs.

  5. Local properties of local multiplicity distributions in hadronic Z decay

    Energy Technology Data Exchange (ETDEWEB)

    Chekanov, S.V.; Kittel, W.; Metzger, W.J

    1999-03-01

    Preliminary results on local multiplicity fluctuations in hadronic Z decays are presented. The data were obtained using the L3 detector at LEP. It is investigated to what extent Monte-Carlo models, which are tuned to reproduce global event-shape variables and single-particle inclusive distributions, can describe the local fluctuations measured by means of bunching parameters.

  6. Local properties of local multiplicity distributions in hadronic Z decay

    Energy Technology Data Exchange (ETDEWEB)

    Chekanov, S.V.; Kittel, W.; Metzger, W.J. [Nijmegen Univ. (Netherlands). High Energy Phys. Inst.; L3 Collaboration

    1999-03-01

    Preliminary results on local multiplicity fluctuations in hadronic Z decays are presented. The data were obtained using the L3 detector at LEP. It is investigated to what extent Monte-Carlo models, which are tuned to reproduce global event-shape variables and single-particle inclusive distributions, can describe the local fluctuations measured by means of bunching parameters. (orig.) 16 refs.

  7. Human skin basement membrane-associated heparan sulphate proteoglycan: distinctive differences in ultrastructural localization as a function of developmental age

    DEFF Research Database (Denmark)

    Horiguchi, Y; Fine, J D; Couchman, J R

    1991-01-01

    Recent studies have demonstrated that skin basement membrane components are expressed within the dermo-epidermal junction in an orderly sequence during human foetal development. We have investigated the ultrastructural localization of basement membrane-related antigens in human foetal skin...... was identical to that observed in neonatal and adult human skin. These findings demonstrate that active remodelling of the dermo-epidermal junction occurs during at least the first two trimesters, and affects not only basement membrane-associated structures but also specific antigens....... at different developmental ages using two monoclonal antibodies to a well-characterized basement membrane-associated heparan sulphate proteoglycan. A series of foetal skin specimens (range, 54-142 gestational days) were examined using an immunoperoxidase immunoelectron microscopic technique. In specimens...

  8. Ultrastructural Localization of Polygalacturonase in Ethylene-Stimulated Abscission of Tomato Pedicel Explants

    Directory of Open Access Journals (Sweden)

    Ming-Fang Qi

    2014-01-01

    Full Text Available Polygalacturonase (PG is crucial in plant organ abscission process. This paper investigated the cellular and subcellular localization of PG in ethylene-stimulated abscission of tomato pedicel explants. Confocal laser scanning microscopy of abscission zone sections with the fluorescent probe Cy3 revealed that PG was initially accumulated in parenchyma cells in cortical and vascular tissues after 8 h of ethylene treatment and then extended throughout the abscission zone when the abscission zone separated at 24 h after ethylene treatment. At the subcellular level, transmission electron microscopy with immunogold staining showed that PG showed abundant accumulation in the cortical and vascular tissues at 8 h after ethylene treatment, and the distribution area extended to the central parenchyma cells at 16 h after ethylene treatment. In addition, PGs were observed in the distal and proximal parts of the tomato pedicel explants throughout the abscission process. The results provided a visualized distribution of PG in the pedicel abscission zone and proved that PG was closely related to abscission.

  9. Distribution and Structure of Purkinje Fibers in the Heart of Ostrich (Struthio camelus with the Special References on the Ultrastructure

    Directory of Open Access Journals (Sweden)

    Paria Parto

    2013-01-01

    Full Text Available Purkinje fibers or Purkinje cardiomyocytes are part of the whole complex of the cardiac conduction system, which is today classified as specific heart muscle tissue responsible for the generation of the heart impulses. From the point of view of their distribution, structure and ultrastructural composition of the cardiac conduction system in the ostrich heart were studied by light and electron microscopy. These cells were distributed in cardiac conducting system including SA node, AV node, His bundle and branches as well as endocardium, pericardium, myocardium around the coronary arteries, moderator bands, white fibrous sheet in right atrium, and left septal attachment of AV valve. The great part of the Purkinje fiber is composed of clear, structure less sarcoplasm, and the myofibrils tend to be confined to a thin ring around the periphery of the cells. They have one or more large nuclei centrally located within the fiber. Ultrastructurally, they are easily distinguished. The main distinction feature is the lack of electron density and having a light appearance, due to the absence of organized myofibrils. P-cells usually have two nuclei with a mass of short, delicate microfilaments scattered randomly in the cytoplasm; they contain short sarcomeres and myofibrillar insertion plaque. They do not have T-tubules.

  10. Ultrastructural localization of Charcot-Leyden crystal protein in human eosinophils and basophils.

    Science.gov (United States)

    Calafat, J; Janssen, H; Knol, E F; Weller, P F; Egesten, A

    1997-01-01

    The Charcot-Leyden crystal (CLC) protein with lysophospholipase activity and carbohydrate-binding properties is a characteristic constituent of eosinophils and basophils. We investigated its subcellular distribution using immunoelectron microscopy. Eosinophil progenitors, mature eosinophils and basophils all contained CLC protein in their cytosol and in the euchromatin of the nucleus. A minor population of granules in eosinophils, increasing in number with maturation, and a more abundant granule-population in basophils, were found to contain CLC protein. Double-labeling experiments showed, in eosinophils, that CLC protein-containing granules contain also eosinophil peroxidase, a characteristic specific granule protein. This suggests a relationship between the CLC protein-containing organelle and the specific granule. In basophils both the CLC protein positive and the negative granules showed the same characteristic particulate-like structure of the granular matrix and both share the same membrane marker CD63. In nasal polyps, macrophages were observed phagocytosing necrotic eosinophils. In these macrophages CLC protein-containing vesicles were observed, probably representing late endosomes. The dual (cytosolic/nuclear and granular) localization of CLC protein suggests that this protein enters both a secretory and a nonsecretory pathway during its biosynthesis, indicating functional roles for this protein both within the cell and extracellularly.

  11. Ultrastructural localization of metals in specimens of Littorina littorea collected from clean and polluted sites

    Energy Technology Data Exchange (ETDEWEB)

    MAson, A.Z.; Simkiss, K.; Ryan, K.P.

    1984-08-01

    Specimens of the periwinkle, Littorina littorea, were collected from a relatively unpolluted site on the Menai Straight, N. Wales, or from the heavily polluted site at Restronguet Creek on the Fal Estuary, Cornwall. The ultrastructural organization of various metal-containing cells of the specimens were analyzed to provide information on the specificity and identity of the biochemical pathways involved in manipulating the metals. The majority of the metals were bound to intracellular ligands. The diversity of ligands includes differences in both composition of the ligands and their availability to pollutant metals. The ligands are usually compartmentalized within membrane-delineated structures. The basophil cells and connective tissue calcium cells appear to contain oxygen donor ligands which mainly bind class A metals (e.g. Ca, Mg, K, Mn). The pore cells and ctenidium contain sulphur donor ligands which mainly bind copper. Ligands of unknown composition occur in the nephrocytes and stomach epithelial cells. The effects of ligand specificity, induction and turnover rates will lead to variation in the results obtained in the use of an organism such as L. littorea as a monitoring system for metal pollution. 34 references, 6 figures, 2 tables.

  12. Restructuring local distribution services: Possibilities and limitations

    Energy Technology Data Exchange (ETDEWEB)

    Duann, D.J.

    1994-08-01

    The restructuring of local distribution services is now the focus of the natural gas industry. It is the last major step in the ``reconstitution`` of the natural gas industry and a critical clement in realizing the full benefits of regulatory and market reforms that already have taken place in the wellhead and interstate markets. It could also be the most important regulatory initiative for most end-use customers because they are affected directly by the costs and reliability of distribution services. Several factors contribute to the current emphasis on distribution service restructuring. They include the unbundling and restructuring of upstream markets, a realization of the limitations of supply-side options (such as gas procurement oversight), and the increased diversity and volatility of gas demand facing local distribution companies. Local distribution service is not one but a series of activities that start with commodity gas procurement and extend to transportation, load balancing, storage, and metering and billing of services provided. There are also considerable differences in the economies of scale and scope associated with these various activities. Thus, a mixture of supply arrangements (such as a competitive market or a monopoly) is required for the most efficient delivery of local distribution services. A distinction must be made between the supply of commodity gas and the provision of a bundled distribution service. This distinction and identification of the best supply arrangements for various distribution service components are the most critical factors in developing appropriate restructuring policies. For most state public utility commissions the criteria for service restructuring should include pursuing the economies of scale and scope in gas distribution, differentiating and matching gas service reliability and quality with customer requirements, and controlling costs associated with the search, negotiation, and contracting of gas services.

  13. Ultrastructural evidence for pre- and postsynaptic localization of Cav1.2 L-type Ca2+ channels in the rat hippocampus.

    Science.gov (United States)

    Tippens, Alyssa L; Pare, Jean-Francois; Langwieser, Nicole; Moosmang, Sven; Milner, Teresa A; Smith, Yoland; Lee, Amy

    2008-02-01

    In the hippocampal formation, Ca(v)1.2 (L-type) voltage-gated Ca(2+) channels mediate Ca(2+) signals that can trigger long-term alterations in synaptic efficacy underlying learning and memory. Immunocytochemical studies indicate that Ca(v)1.2 channels are localized mainly in the soma and proximal dendrites of hippocampal pyramidal neurons, but electrophysiological data suggest a broader distribution of these channels. To define the subcellular substrates underlying Ca(v)1.2 Ca(2+) signals, we analyzed the localization of Ca(v)1.2 in the hippocampal formation by using antibodies against the pore-forming alpha(1)-subunit of Ca(v)1.2 (alpha(1)1.2). By light microscopy, alpha(1)1.2-like immunoreactivity (alpha(1)1.2-IR) was detected in pyramidal cell soma and dendritic fields of areas CA1-CA3 and in granule cell soma and fibers in the dentate gyrus. At the electron microscopic level, alpha(1)1.2-IR was localized in dendrites, but also in axons, axon terminals, and glial processes in all hippocampal subfields. Plasmalemmal immunogold particles representing alpha(1)1.2-IR were more significant for small- than large-caliber dendrites and were largely associated with extrasynaptic regions in dendritic spines and axon terminals. These findings provide the first detailed ultrastructural analysis of Ca(v)1.2 localization in the brain and support functionally diverse roles of these channels in the hippocampal formation. (c) 2007 Wiley-Liss, Inc.

  14. On Locality in Distributed Storage Systems

    CERN Document Server

    Rawat, Ankit Singh

    2012-01-01

    This paper studies the design of codes for distributed storage systems (DSS) that enable local repair in the event of node failure. This paper presents locally repairable codes based on low degree multivariate polynomials. Its code construction mechanism extends work on Noisy Interpolating Set by Dvir et al. \\cite{dvir2011}. The paper presents two classes of codes that allow node repair to be performed by contacting 2 and 3 surviving nodes respectively. It further shows that both classes are good in terms of their rate and minimum distance, and allow their rate to be bartered for greater flexibility in the repair process.

  15. Local average height distribution of fluctuating interfaces

    Science.gov (United States)

    Smith, Naftali R.; Meerson, Baruch; Sasorov, Pavel V.

    2017-01-01

    Height fluctuations of growing surfaces can be characterized by the probability distribution of height in a spatial point at a finite time. Recently there has been spectacular progress in the studies of this quantity for the Kardar-Parisi-Zhang (KPZ) equation in 1 +1 dimensions. Here we notice that, at or above a critical dimension, the finite-time one-point height distribution is ill defined in a broad class of linear surface growth models unless the model is regularized at small scales. The regularization via a system-dependent small-scale cutoff leads to a partial loss of universality. As a possible alternative, we introduce a local average height. For the linear models, the probability density of this quantity is well defined in any dimension. The weak-noise theory for these models yields the "optimal path" of the interface conditioned on a nonequilibrium fluctuation of the local average height. As an illustration, we consider the conserved Edwards-Wilkinson (EW) equation, where, without regularization, the finite-time one-point height distribution is ill defined in all physical dimensions. We also determine the optimal path of the interface in a closely related problem of the finite-time height-difference distribution for the nonconserved EW equation in 1 +1 dimension. Finally, we discuss a UV catastrophe in the finite-time one-point distribution of height in the (nonregularized) KPZ equation in 2 +1 dimensions.

  16. Distribution and ultrastructural features of the serotonin innervation in rat and squirrel monkey subthalamic nucleus.

    Science.gov (United States)

    Parent, Martin; Wallman, Marie-Josée; Descarries, Laurent

    2010-04-01

    The main purpose of this light and electron microscopic immunocytochemical study was to characterize and compare the serotonin (5-HT) innervation of the subthalamic nucleus (STN) in rats and squirrel monkeys (Saimiri sciureus) following labeling with an antibody against the 5-HT transporter (SERT). Unbiased counts of SERT+ axon varicosities revealed an average density of 5-HT innervation higher in monkeys (1.52 x 10(6) varicosities/mm3) than rats (1.17 x 10(6)), particularly in the anterior half of the nucleus (1.70 x 10(6)). As measured by electron microscopy, SERT+ axon varicosity profiles in the STN of both species were smaller than unlabeled profiles. The number of SERT+ profiles displaying a synaptic junction indicated that, in both rat and monkey STN, approximately half of 5-HT axon varicosities were asynaptic. In monkeys, all synaptic junctions made by SERT+ varicosities were asymmetrical, as opposed to only 77% in rats. Despite the higher density of 5-HT innervation in the anterior half of monkey STN, the ultrastructural features of its SERT+ varicosities, including synaptic incidence, did not significantly differ from those in its posterior half. These findings suggest that, throughout the rat and monkey STN, 5-HT afferents may exert their influence via both synaptic delivery and diffusion of 5-HT, and that an ambient level of 5-HT maintained in STN by these two modes of transmission might also modulate neuronal activity and influence motor behavior. A better understanding of the factors governing the complex interplay between these signaling processes would greatly improve our knowledge of the physiopathology of the STN.

  17. Ultrastructural and immunohistochemical localization of plasma membrane Ca2+-ATPase 4 in Ca2+-transporting epithelia

    DEFF Research Database (Denmark)

    Alexander, R Todd; Beggs, Megan R; Zamani, Reza

    2015-01-01

    Plasma Membrane Ca(2+)-ATPase's (PMCA) participate in epithelial Ca(2+) transport and intracellular Ca(2+) signaling. The Pmca4 isoform is enriched in distal nephron isolates and decreased in mice lacking the epithelial Ca(2+) channel, Trpv5. We therefore hypothesized that Pmca4 plays a significant...... in distal nephron cells at both the basolateral membrane and intracellular perinuclear compartments, but not submembranous vesicles, suggesting rapid trafficking to the plasma membrane is unlikely to occur in vivo. Pmca4 expression was not altered by perturbations in Ca(2+) balance, pointing...... detected Pmca1 in lateral membranes of enterocytes. In kidney, Pmca4 showed broad localization to the distal nephron. In mouse, expression was most abundant in segments coexpressing the epithelial Ca(2+) channel, Trpv5. Significant, albeit lower expression, was also evident in the region encompassing...

  18. Ultrastructural localization of uranium biosorption in Penicillium digitatum by stem x-ray microanalysis

    Energy Technology Data Exchange (ETDEWEB)

    Galun, M.; Siegel, S.M.; Cannon, M.I.; Siegel, B.Z.; Galun, E.

    1987-01-01

    When Penicillium digitatum Saccardo cultures are exposed to aqueous solutions containing soluble uranium salts, considerable amounts of this element are accumulated in the fungal mycelium. The accumulated uranium is retained after thorough rinsing with distilled water but is removed by alkali carbonate solutions. Analysis of thick sections (0.5 ..mu..m) of the fungal hyphae with TEM, after incubation in UO/sub 2/Cl/sub 2/ solutions of varying concentrations under both light and dark conditions, revealed conspicuous crystal-like deposits in UO/sub 2/Cl/sub 2/-exposed hyphae, but none in the control hyphae. Thick sections were necessary for crystal visualization. Using energy-dispersive X-ray analysis, uranium was detected as the only heavy element in these crystals. Uranium crystal biosorption was localized on the outside surface of the hyphal cell wall (following short exposures to relatively low uranium concentrations) or inside the cell wall (following long exposure to relatively high uranium concentrations). In some cases, crystal-like deposits of uranium salts were located on the outside surface as well as inside the cell.

  19. Ultrastructure and mineral distribution in the tergal cuticle of the terrestrial isopod Titanethes albus. Adaptations to a karst cave biotope.

    Science.gov (United States)

    Hild, Sabine; Neues, Frank; Znidarsic, Nada; Strus, Jasna; Epple, Matthias; Marti, Othmar; Ziegler, Andreas

    2009-12-01

    Composition and spatial distribution of organic and inorganic materials within the cuticle of isopods vary between species. These variations are related to the behaviour and habitat of the animal. The troglobiotic isopod Titanethes albus lives in the complete darkness of caves in the Slovenian Karst. This habitat provides constant temperature and saturated humidity throughout the year and inconsistent food supply. These conditions should have lead to functional adaptations of arthropod cuticles. However, studies on structure and composition of cave arthropod cuticles are rare and lacking for terrestrial isopods. We therefore analysed the tergite cuticle of T. albus using transmission and field-emission electron microscopy, confocal micro-Raman spectroscopic imaging, quantitative X-ray diffractometry, thermogravimetric analysis and atomic absorption spectroscopy. The ultrastructure of the epicuticle suggests a poor resistance against water loss. A weak interconnection between the organic and mineral phase within the endo- and exocuticle, a comparatively thin apical calcite layer, and almost lack of magnesium within the calcite crystal lattice suggest that the mechanical strength of the cuticle is low in the cave isopod. This may possibly be of advantage in maintaining high cuticle flexibility and reducing metabolic expenditures.

  20. Composition and distribution of elements and ultrastructural topography of a human cardiac calculus.

    Science.gov (United States)

    Cheng, Ching-Li; Chang, Hsiao-Huang; Huang, Pei-Jung; Chu, Yu-Ting; Lin, Shan-Yang

    2013-04-01

    Trace elements (TEs) may contribute to the formation of calculi or stones or be involved in the aetiopathogenesis of stone diseases. The compositions and spatial distribution of elements from the inner nucleus to outer crust of the cardiac calculus were investigated by energy-dispersive X-ray fluorescence (EDXRF) spectrometer. The surface topograph, distribution map of elements, elemental and chemical compositions were also determined by environmental scanning electron microscope (ESEM)-energy-dispersive X-ray (EDX) analysis. Twenty-five elements were identifiable from 18 positions on the cardiac calculus by EDXRF spectrometer, in which the highest concentrations of toxic TEs (Ni, Pt, Hg, Sn, Pb, W, Au, Al, Si) and higher levels of essential TEs (Ca, Sr, Cr, P) were detected. A moderate positive Pearson's correlation between TEs concentrations of Mg, Ca or P and location differences from centre to periphery in the cardiac calculus was observed. A positive correlation was also found for Ca/Zn and Ca/Cu, indicating the gradual increase of calcium concentration from inner nucleus to outer crust of cardiac calculus. The drop-like nodules/crystals on the surface of petrous part of cardiac calculus were observed from ESEM analysis. ESEM-EDX analysis determined the calculus to be predominantly composed of calcium hydroxyapatite and cholesterol, as indicated by the petrous surface and drop-like nodules/crystals, respectively. This composition was confirmed using a portable Raman analyser. The spatial distribution analysis indicated a gradual increase in Mg, P and Ca concentrations from the inner nucleus to the outer crust of the cardiac calculus. The major chemical compositions of calcium hydroxyapatite and cholesterol were detected on this cardiac calculus.

  1. [Supplemental data to the ultrastructural study of Trichomonas tenax. Intra-cellular distribution of acid phosphatase].

    Science.gov (United States)

    Ribaux, C L; Magloire, H

    1980-09-01

    In scanning electron microscopy, the flagella come out from the cellular body following different configurations: either separately or in groups. The undulating membrane lasted up to 2/3 of the cell body: at its end the recurrent flagella seems to penetrate again into the cell. The costa starts from the cinetosome of the recurrent flagella: the two parabasal filaments start from two different cinetosomes and follow the costa for a small distance. The nucleus is surrounded by a membrane which is not always visible. The axostyle has a cylindrical shape in the posterior two thirds of the cell. Bacteria at different stages of phagocytosis have been observed. The acid phosphatase is localized in the saccules and vesicles of the Golgi apparatus, in the lysosomes and phagolysosomes and in the terminal lamina of the undulating membrane.

  2. Local search in physical distribution management

    NARCIS (Netherlands)

    G.A.P. Kindervater (Gerard); M.W.P. Savelsbergh (Martin)

    1992-01-01

    textabstractPhysical distribution management presents a variety of decision making problems at three levels of strategic, tactical and operational planning. The importance of effective and efficient distribution management is evident from its associated costs. Physical distribution management at the

  3. [Tooth macromorphological and ultrastructural analysis of osteological material from the medieval locality of St. Panteleimon Church in Nis].

    Science.gov (United States)

    Mitić, Nadica; Mitić, Aleksandar; Mitić, Vladimir; Savić, Vojin; Nikolić, Marija

    2010-01-01

    Analysis of macromorphological and ultrastructural tooth characteristics of osteological material from the medieval site of St. Pantaleimon Church in Nis provides us with insight on the life, nutrition and habits of medieval population, as well as the structure and composition of their teeth. The aim of this research, based on the tooth inspection of skeletal remains from the medieval site of St. Pantaleimon Church in Nis, was to analyze macromorphological characteristics, ultrastructure of the dental tissue of maxillary and mandibular molars, canines and incisors, as well as their chemical composition. Macromorphological and ultrastructural analysis of the dental tissue of osteological material dating from the 12th century included 1312 teeth with advanced abrasion. Macromorphological changes were detected by using a dental mirror, probe and radiography. After irrigation, the teeth were prepared using the standard procedure and analyzed by scanning electronic microscopy (JEOL-JSM-5300). Chemical analysis was done by expanded downscaling (EDS) method for Mg, P, Ca. The analysis detected second degree abrasions of all teeth in individuals aged 20-25 years. Third and fourth degree abrasions of teeth were detected in individuals aged over 40 years. Ultrastructural analysis showed a complete obliteration of dentin tubules and pulp of the lower incisors, the apposition of intratubular dentin inside the tubules, as well as extensive deformity and loss of dentin structure on molars with preserved pulp volume and nerve fiber calcification. The calcification of nerve fibers showed that the formation of intratubular dentin was proportional with the biological potential of pulp and the degree of abrasion, and inversely proportional with the size of dentin surface. Chemical analysis showed that in the analyzed teeth Ca composition was slightly lower than that in the control group, P composition was almost identical, while Mg composition was multiply increased in comparison to

  4. Distribution and ultrastructure of the stomata connecting the pleural cavity with lymphatics in the rat costal pleura.

    Science.gov (United States)

    Wang, Q X; Ohtani, O; Saitoh, M; Ohtani, Y

    1997-01-01

    We investigated the detailed distribution and ultrastructure of the stomata connecting the pleural cavity and the lymphatics in the rat costal pleura by scanning electron, transmission electron and light microscopy. The mesothelial cells lining the costal pleura appeared as both flattened and thick cell bodies. The thick cells possessed more rough endoplasmic reticula, Golgi complexes, mitochondria, and free ribosomes than the flattened cells. The thick cells were distributed in the intercostal regions each cephalic to the junction of the costal cartilage and bone, and in the band-like regions along the cephalic and caudal sides of each rib in the lateral and dorsal thoracic walls. In the regions lined with thick cells, there were stomata [12.9 +/- 10.3 microns2 (mean +/- SD) in area] consisting of prolongations of thick mesothelial cells and funnel-like projections of lymphatic endothelial cells that came up along the rims of the pores (5.9 +/- 3.2 microns2 in average area) in the submesothelial collagen fiber network. At the stomata, the basal lamina of the mesothelium was continuous with that of the endothelium. The mesothelial cells forming the stomata were mostly in close contact with the endothelial cells, but some gaps also existed between them. Valve-like endothelial flaps were frequently observed wherever endothelial cells constituting the stomata merged into the submesothelial lymphatics. Also present were lymphatic bulges that were either in close contact with the base of the thick mesothelial cells or exposed through the mesothelial pores. The lymphatic network was especially well developed in the submesothelial layer at and around the thick-cell regions. The initial lymphatics drained into the intercostal collecting lymphatics, which in turn led into either the parasternal or paravertebral lymphatic trunk. Our results suggest that the stomata play a major role in absorbing fluids and particulates in the pleural cavity. The thick mesothelial cells

  5. Ultrastructural localization of intracellular immunoglobulins in Epon-embedded human lymph nodes. An immunoelectron microscopic investigation using the immunogold staining (IGS) and the avidin-biotin-peroxidase complex (ABC) methods.

    Science.gov (United States)

    Viale, G; Dell'Orto, P; Braidotti, P; Coggi, G

    1985-05-01

    The ultrastructural localization of intracellular immunoglobulins on ultrathin sections of glutaraldehyde-fixed, postosmicated, and Epon-embedded human lymph nodes has been achieved using such highly sensitive immunocytochemical techniques as immunogold staining and avidin-biotin-peroxidase complex. These immunoelectron microscopic techniques allow the identification of intracellular immunoglobulins without affecting the ultrastructural morphology of the tissue, since they do not require any pretreatment of the sections with proteolytic enzymes or deresinating agents. Therefore, immunoglobulins can be precisely localized in the cell organelles; structures whose morphology is well preserved. The availability of a reliable postembedding staining procedure for the ultrastructural localization of immunoglobulins is of definite value for investigations on human lymphoid tissue, both normal and pathological.

  6. Local search in physical distribution management

    OpenAIRE

    1992-01-01

    textabstractPhysical distribution management presents a variety of decision making problems at three levels of strategic, tactical and operational planning. The importance of effective and efficient distribution management is evident from its associated costs. Physical distribution management at the operational level, which is considered in this paper is responsible for an important fraction of the total distribution costs. Not surprisingly, there is a growing demand for planning systems that...

  7. Ultrastructural localization of silver in rat testis and organ distribution of radioactive silver in the rat

    DEFF Research Database (Denmark)

    Ernst, E; Rungby, J; Baatrup, E

    1992-01-01

    The deposition of silver after a single intravenous injection (2 micrograms Ag g-1 body weight) was studied in the testes of Wistar rats 24 h and 1 and 2 weeks after dosing with radiolabelled 110AgNo3 (2 micrograms Ag and 1.2 kBq g-1 body weight). Also, the temporal accumulation of silver during ...

  8. Pricing local distribution services in a competitive market

    Energy Technology Data Exchange (ETDEWEB)

    Duann, D.J.

    1995-12-01

    Unbundling and restructuring of local distribution services is the focus of the natural gas industry. As a result of regulatory reforms, a competitive local distribution market has emerged, and the validity of traditional cost-based regulation is being questioned. One alternative is to completely unbundle local distribution services and transform the local distribution company into a common carrier for intrastate transportation services. Three kinds of alternative pricing mechanisms are examined. For firm intrastate transportation services, cost-based pricing is the preferred method unless it can be shown that a competitive secondary market can be established and maintained. Pricing interruptible transportation capacity is discussed.

  9. An Efficient Local Algorithm for Distributed Multivariate Regression

    Data.gov (United States)

    National Aeronautics and Space Administration — This paper offers a local distributed algorithm for multivariate regression in large peer-to-peer environments. The algorithm is designed for distributed...

  10. A Scalable Local Algorithm for Distributed Multivariate Regression

    Data.gov (United States)

    National Aeronautics and Space Administration — This paper offers a local distributed algorithm for multivariate regression in large peer-to-peer environments. The algorithm can be used for distributed...

  11. Tendon's ultrastructure.

    Science.gov (United States)

    Tresoldi, Ilaria; Oliva, Francesco; Benvenuto, Monica; Fantini, Massimo; Masuelli, Laura; Bei, Roberto; Modesti, Andrea

    2013-01-01

    The structure of a tendon is an important example of complexity of ECM three-dimensional organization. The extracellular matrix (ECM) is a macromolecular network with both structural and regulatory functions. ECM components belong to four major types of macromolecules: the collagens, elastin, proteoglycans, and noncollagenous glycoproteins. Tendons are made by a fibrous, compact connective tissue that connect muscle to bone designed to transmit forces and withstand tension during muscle contraction. Here we show the ultrastructural features of tendon's components.

  12. Object Management in Local Distributed Systems

    Science.gov (United States)

    1985-11-01

    Theory, Vol. 2, Jack Minker et a.l. editors, Plenum Press, New York, IQ84. / A3/ Gottlob , G., P. Paolini, and R. Zicari, "Properties and Update Semantics...February 1980. /D3/ Enslow, P., "What is a ’distributed’ data processing system?" IEEE Computer, 11, 1, January 1978. /D4/ Gottlob , G. and R. Zicari

  13. Shaped input distributions for structural damage localization

    DEFF Research Database (Denmark)

    Ulriksen, Martin Dalgaard; Bernal, Dionisio; Damkilde, Lars

    2017-01-01

    Given a structure in a state with any type of perturbation, the steady-state vibrational response will be identical to that in the unperturbed state if the perturbation is rendered dormant and, of course, if the load distribution is the same in the two states. Guided by this principle, a damage l...

  14. Binding-energy distribution and dephasing of localized biexcitons

    DEFF Research Database (Denmark)

    Langbein, Wolfgang Werner; Hvam, Jørn Märcher; Umlauff, M.

    1997-01-01

    We report on the binding energy and dephasing of localized biexciton states in narrow ZnSe multiple quantum wells. The measured binding-energy distribution of the localized biexcitons shows a width of 2.2 meV centered at 8.5 meV, and is fairly independent of the exciton localization energy. In four...

  15. Localization theory of distributed fiber vibration sensor

    Institute of Scientific and Technical Information of China (English)

    Weimin Chen; Yuanyuan Xie; Peng Zhang; Lei Lin

    2009-01-01

    Based on Sagnac interferometer, a simple distributed optical fiber sensing system with sub-loop is pre-sented to monitor the vibration applied on the sensing fiber. By introducing a sub-loop, three output beams of interference with different delay time are gotten. Location of the vibration is analyzed through mathematical-physical equations. The vibration frequency, amplitude, and location are theoretically sim-ulated. The results agree well with the previous experiments.

  16. Optimal operation of water distribution networks under local pipe failures

    Institute of Scientific and Technical Information of China (English)

    TIAN Yi-mei; G.Y.FU; CHI Hai-yan; LIU Ye

    2007-01-01

    The optimal operation of water distribution networks under local pipe failures, such as water main breaks, was proposed.Based on a hydraulic analysis and a simulation of water distribution networks, a macroscopic model for a network under a local pipe failure was established by the statistical regression. After the operation objectives under a local pipe failure were determined, the optimal operation model was developed and solved by the genetic algorithm. The program was developed and examined by a city distribution network. The optimal operation alternative shows that the electricity cost is saved approximately 11%, the income of the water corporation is increased approximately 5%, and the pressure in the water distribution network is distributed evenly to ensure the network safe operation. Therefore, the proposed method for optimal operation under local pipe failure is feasible and cost-effective.

  17. The effects of electrical stunning methods on broiler meat quality: effect on stress, glycolysis, water distribution, and myofibrillar ultrastructures.

    Science.gov (United States)

    Huang, J C; Huang, M; Yang, J; Wang, P; Xu, X L; Zhou, G H

    2014-08-01

    This study was designed to compare the effects of different stunning systems on the meat quality of broilers. This was done by investigating meat water-holding capacity, meat color, muscle glycogen, and lactate concentrations, as well as blood parameters, low-field nuclear magnetic resonance (NMR) transverse relaxation, and myofibrillar ultrastructures. A total of 160 broilers were divided into 4 treatment groups: a low-voltage stunning (LS) with a constant voltage of 15 V at 750 Hz for 10 s; a midvoltage stunning (MS) with a constant voltage of 50 V at 50 Hz for 10 s; a high-voltage stunning (HS) with a constant voltage of 100 V at 50 Hz for 5 s; and a control group with no stunning (NS). Blood samples were collected immediately after cutting the neck. Pectoralis major muscles were removed from the carcass after chilling and placed in ice. Breast muscle pH, meat color, glycogen, and lactate contents were determined at both 2 and 24 h postmortem. Drip loss, cooking loss, pressing loss, cooked breast meat shear values, low-field NMR, and ultrastructures of myofibrils were determined 24 h postmortem. The NS and MS treatments significantly increased (P plasma corticosterone, initial rate of glycolysis, and drip loss, and significantly reduced (P low-field NMR reflect that NS and MS significantly decreased (P treatments reduce meat water-holding capacity and decrease meat shear force when compared with LS and HS.

  18. Distributional Dimension of Fractal Sets in Local Fields

    Institute of Scientific and Technical Information of China (English)

    Hua QIU; Wei Yi SU

    2008-01-01

    The distributional dimension of fractal sets in Rn has been systematically studied by Triebel by virtue of the theory of function spaces.In this paper,we .rst discuss some important properties about the B type spaces and the F type spaces on local .elds,then we give the de .nition of the distributional dimension dim D in local .elds and study the relations between distributional dimension and Hausdor .dimension.Moreover,the analysis expression of the Hausdor .dimension is given.Lastly,we de .ne the Fourier dimension in local .elds,and obtain the relations among all the three dimensions.

  19. Immunoelectron microscopical localization of a circulating antigen in the excretory system of Schistosoma mansoni. Ultrastructural localization studies of the excretory system of S. mansoni.

    Science.gov (United States)

    Bogers, J J; Nibbeling, H A; Van Marck, E A; Deelder, A M

    1995-01-01

    In this study the excretory system of Schistosoma mansoni was ultrastructurally examined with a recently described monoclonal antibody (mAb) against a circulating antigen. In previous studies this mAb was found to have affinity for the excretory system. Strong immunoreactivity was found on the flagella of the flame cells and of the collecting ducts throughout the worm. The eggshell and the space between the miracidium and the eggshell showed strong reactivity with a declining gradient towards the exterior, suggesting a secretion process. In cercariae, immunoreactivity was restricted to the tegument, whereas in schistosomula the labeling pattern resembled that of the adult worm, demonstrating positive reactivity of the flame cells and no immunostaining of the tegument. This stage-dependent differential expression of different antigens in the excretory system and in the tegument could suggest a maturation process of the excretory system.

  20. Reconstructing the three-dimensional local dark matter velocity distribution

    CERN Document Server

    Kavanagh, Bradley J

    2016-01-01

    Directionally sensitive dark matter (DM) direct detection experiments present the only way to observe the full three-dimensional velocity distribution of the Milky Way halo local to Earth. In this work we compare methods for extracting information about the local DM velocity distribution from a set of recoil directions and energies in a range of hypothetical directional and non-directional experiments. We compare a model independent empirical parameterisation of the velocity distribution based on an angular discretisation with a model dependent approach which assumes knowledge of the functional form of the distribution. The methods are tested under three distinct halo models which cover a range of possible phase space structures for the local velocity distribution: a smooth Maxwellian halo, a tidal stream and a debris flow. In each case we use simulated directional data to attempt to reconstruct the shape and parameters describing each model as well as the DM particle properties. We find that the empirical pa...

  1. Distribution of DNA and localization of rRNA transcription in G2 phase nucleolus of Physarum polycephalum

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Using electron microscopy, NAMA-Ur DNA selective staining and BrUTP incorporation, the nucleo lus ultrastructure, the distribution of DNA and the rRNA transcription sites in nucleolus of G2 phase Physarum poly cephalum were studied. The nucleolus was found to be different in structure from that of other plant cells. Fibrillar cen tern (FCs) were present in a large amount all over the nucleolus. DNA was distributed both in dense fibrillar components (DFC) and in FC. The DNA in the nucleolus was less condensed than that of the chromosome territory. These changes suggested that the transcription was active within the nucleolus. BrUTP incorporation localized the rRNA transcription in DFC and at the interface of FC and DFC, suggesting that the DNA in FC is in a storage form and only the rDNA in DFC is transcribed.

  2. Higher-order momentum distributions and locally affine LDDMM registration

    DEFF Research Database (Denmark)

    Sommer, Stefan Horst; Nielsen, Mads; Darkner, Sune;

    2013-01-01

    higher-order momentum distributions in the large deformation diffeomorphic metric mapping (LDDMM) registration framework. While the zeroth-order moments previously used in LDDMM only describe local displacement, the first-order momenta that are proposed here represent a basis that allows local...

  3. Sound source localization using distributed elevated acoustic sensors

    Science.gov (United States)

    Di, Xiao; Wagstaff, Ronald A.; Anderson, John D.; Gilbert, Kenneth E.

    2009-05-01

    Detecting and localizing impulsive acoustic sources in the daytime using distributed elevated acoustic sensors with large baseline separations has distinct advantages over small ground-based arrays. There are generally two reasons for this: first, during the daytime, because of more direct and less encumbered propagation paths, signal levels are generally larger at altitude than near the ground. Second, larger baselines provide improved localization accuracy. Results are reported from a distributed array of acoustic sensors deployed during an experiment near Bourges, France during June of 2008. The distributed array consisted of microphones and GPS receivers attached to the tether lines of three widely separated aerostats. The sound sources were various impulsive devices. Results from the measurements are presented and discussed. Localization errors (GPS accuracy, propagation calculation, and aerostat motion, etc) are discussed. Possible ways to improve the localization accuracy are suggested.

  4. Local Control of Reactive Power by Distributed Photovoltaic Generators

    CERN Document Server

    Turitsyn, Konstantin S; Backhaus, Scott; Chertkov, Misha

    2010-01-01

    High penetration levels of distributed photovoltaic (PV) generation on an electrical distribution circuit may severely degrade power quality due to voltage sags and swells caused by rapidly varying PV generation during cloud transients coupled with the slow response of existing utility compensation and regulation equipment. Although not permitted under current standards for interconnection of distributed generation, fast-reacting, VAR-capable PV inverters may provide the necessary reactive power injection or consumption to maintain voltage regulation under difficult transient conditions. As side benefit, the control of reactive power injection at each PV inverter provides an opportunity and a new tool for distribution utilities to optimize the performance of distribution circuits, e.g. by minimizing thermal losses. We suggest a local control scheme that dispatches reactive power from each PV inverter based on local instantaneous measurements of the real and reactive components of the consumed power and the re...

  5. Ultra-structural cell distribution of the melanoma marker iodobenzamide: improved potentiality of SIMS imaging in life sciences

    Directory of Open Access Journals (Sweden)

    Papon Janine

    2004-04-01

    Full Text Available Abstract Background Analytical imaging by secondary ion mass spectrometry (SIMS provides images representative of the distribution of a specific ion within a sample surface. For the last fifteen years, concerted collaborative research to design a new ion microprobe with high technical standards in both mass and lateral resolution as well as in sensitivity has led to the CAMECA NanoSims 50, recently introduced onto the market. This instrument has decisive capabilities, which allow biological applications of SIMS microscopy at a level previously inaccessible. Its potential is illustrated here by the demonstration of the specific affinity of a melanoma marker for melanin. This finding is of great importance for the diagnosis and/or treatment of malignant melanoma, a tumour whose worldwide incidence is continuously growing. Methods The characteristics of the instrument are briefly described and an example of application is given. This example deals with the intracellular localization of an iodo-benzamide used as a diagnostic tool for the scintigraphic detection of melanic cells (e.g. metastasis of malignant melanoma. B16 melanoma cells were injected intravenously to C57BL6/J1/co mice. Multiple B16 melanoma colonies developed in the lungs of treated animals within three weeks. Iodobenzamide was injected intravenously in tumour bearing mice six hours before sacrifice. Small pieces of lung were prepared for SIMS analysis. Results Mouse lung B16 melanoma colonies were observed with high lateral resolution. Cyanide ions gave "histological" images of the cell, representative of the distribution of C and N containing molecules (e.g. proteins, nucleic acids, melanin, etc. while phosphorus ions are mainly produced by nucleic acids. Iodine was detected only in melanosomes, confirming the specific affinity of the drug for melanin. No drug was found in normal lung tissue. Conclusion This study demonstrates the potential of SIMS microscopy, which allows the

  6. Ultrastructural immunogold localization of major sperm protein (MSP) in spermatogenic cells of the nematode Acrobeles complexus (Nematoda, Rhabditida).

    Science.gov (United States)

    Yushin, Vladimir V; Claeys, Myriam; Bert, Wim

    2016-10-01

    The nematode spermatozoa represent a highly modified (aberrant) type of male gametes that lack a flagellum but for which the process of spermatogenesis culminates in the production of a crawling spermatozoon on the basis of the cytoskeletal component known as "major sperm protein", or MSP. MSP is also known as an important hormone triggering oocyte maturation and ovulation in the model nematode Caenorhabditis elegans, where this protein was first identified. However, direct evidence of MSP localization and of its fate in nematode spermatogenic cells is rare. In this study, the spermatogenesis and sperm structure in the rhabditid nematode Acrobeles complexus (Rhabditida: Tylenchina: Cephalobomorpha: Cephaloboidea: Cephalobidae) has been examined with electron microscopy. Morphological observations were followed by high-pressure freezing and freeze-substitution fixation which allows post-embedding immunogold localization of MSP in all stages of sperm development using antibodies raised for MSP of C. elegans. In spermatocytes, synthetic activity results in the development of specific cellular components, fibrous bodies (FB) and membranous organelles (MO), which appear as FB-MO complexes where the filamentous matter of FB has been MSP-labeled. The spermatids subdivide into a residual body with superfluous cytoplasm, and a main cell body which contains nucleus, mitochondria and FB-MO complexes. These complexes dissociate into individual components, MO and FB, with the MSP being localized in FB. Immature spermatozoa from testes are opaque cells where a centrally located nucleus is surrounded by mitochondria, MO and FB clustered together, the MSP still being localized only in FB. Cytoplasm of mature spermatozoa from spermatheca is segregated into external pseudopods lacking organelles and a central cluster of mitochondria with intact MO surrounding the central nucleus. The FB ultimately disappear, and the MSP labeling becomes concentrated in the filamentous content of

  7. Distributed Mobile Robot Localization and Communication System for Special Interventions

    OpenAIRE

    Sales Gil, Jorge

    2011-01-01

    This thesis focuses on the development of a distributed mobile robot localization and communication system for special interventions like those carried out by fire-fighters in fire ground search and rescue. The use case scenario is related to the one described for the GUARDIANS EU project, where a swarm formation of mobile robots accompany a fire fighter during a rescue intervention in a warehouse. In this line, localizing the robots and the fire fighter during an indoor intervention with the...

  8. Spatial distributions of red blood cells significantly alter local haemodynamics.

    Directory of Open Access Journals (Sweden)

    Joseph M Sherwood

    Full Text Available Although bulk changes in red blood cell concentration between vessels have been well characterised, local distributions are generally overlooked. Red blood cells aggregate, deform and migrate within vessels, forming heterogeneous distributions which have considerable effect on local haemodynamics. The present study reports data on the local distribution of human red blood cells in a sequentially bifurcating microchannel, representing the branching geometry of the microvasculature. Imaging methodologies with simple extrapolations are used to infer three dimensional, time-averaged velocity and haematocrit distributions under a range of flow conditions. Strong correlation between the bluntness of the velocity and haematocrit profiles in the parent branch of the geometry is observed and red blood cell aggregation has a notable effect on the observed trends. The two branches of the first bifurcation show similar characteristics in terms of the shapes of the profiles and the extent of plasma skimming, despite the difference in geometric configuration. In the second bifurcation, considerable asymmetry between the branches in the plasma skimming relationship is observed, and elucidated by considering individual haematocrit profiles. The results of the study highlight the importance of considering local haematocrit distributions in the analysis of blood flow and could lead to more accurate computational models of blood flow in microvascular networks. The experimental approaches developed in this work provide a foundation for further examining the characteristics of microhaemodynamics.

  9. Reconstructing the three-dimensional local dark matter velocity distribution

    Science.gov (United States)

    Kavanagh, Bradley J.; O'Hare, Ciaran A. J.

    2016-12-01

    Directionally sensitive dark matter (DM) direct detection experiments present the only way to observe the full three-dimensional velocity distribution of the Milky Way halo local to Earth. In this work we compare methods for extracting information about the local DM velocity distribution from a set of recoil directions and energies in a range of hypothetical directional and nondirectional experiments. We compare a model-independent empirical parametrization of the velocity distribution based on an angular discretization with a model-dependent approach which assumes knowledge of the functional form of the distribution. The methods are tested under three distinct halo models which cover a range of possible phase space structures for the local velocity distribution: a smooth Maxwellian halo, a tidal stream and a debris flow. In each case we use simulated directional data to attempt to reconstruct the shape and parameters describing each model as well as the DM particle properties. We find that the empirical parametrization is able to make accurate unbiased reconstructions of the DM mass and cross section as well as capture features in the underlying velocity distribution in certain directions without any assumptions about its true functional form. We also find that by extracting directionally averaged velocity parameters with this method one can discriminate between halo models with different classes of substructure.

  10. Cooperative Localization and Tracking in Distributed Robot-Sensor Networks

    Institute of Scientific and Technical Information of China (English)

    ZHANG Fan; Guilherme S.Pereira; Vijay Kumar

    2005-01-01

    This paper addresses the problem of real-time position and orientation estimation of networked mobile robots in two-dimensional Euclidean space with simultaneous tracking of a rigid unknown object based on exteroceptive sensory information extracted from distributed vision systems. The sufficient and necessary conditions for team localization are proposed. A localization and object tracking approach based on statistical operators and graph searching algorithms is presented for a team of robots localized with heterogeneous sensors. The approach was implemented in an experimental platform consisting of car-like mobile robots equipped with omnidirectional video cameras and IEEE 802.11b wireless networking. The experimental results validate the approach.

  11. Local Pulsars; A note on the Birth-Velocity Distribution

    NARCIS (Netherlands)

    Blaauw, A.; Ramachandran, R.

    1998-01-01

    Submitted to: Astron. Astrophys. Abstract: We explore a simple model for the representation of the observed distributions of the motions, and the characteristic ages of the local population of pulsars. The principal difference from earlier models is the introduction of a unique value, S, for the kic

  12. Local pulsars : A note on the birth-velocity distribution

    NARCIS (Netherlands)

    Blaauw, A; Ramachandran, R

    1998-01-01

    We explore a simple model for the representation of the observed distributions of the motions, and the characteristic ages of the local population of pulsars. The principal difference from earlier models is the introduction of a unique value, S, for the kick velocity with which pulsars are born. We

  13. Local structure studies using the pair distribution function

    Directory of Open Access Journals (Sweden)

    Bordet Pierre

    2015-01-01

    Full Text Available The pair distribution analysis method is a fast spreading structural analysis method allowing to go beyond classical crystallographic analysis by providing quantitative information about local as well as meso-structure. It based on powder diffraction data fourier transformed to direct space. We will present here the main characteristics of the method, and its domain of application.

  14. Price Based Local Power Distribution Management System (Local Power Distribution Manager) v1.0

    Energy Technology Data Exchange (ETDEWEB)

    2016-11-28

    A trans-active energy micro-grid controller is implemented in the VOLTTRON distributed control platform. The system uses the price of electricity as the mechanism for conducting transactions that are used to manage energy use and to balance supply and demand. In order to allow testing and analysis of the control system, the implementation is designed to run completely as a software simulation, while allowing the inclusion of selected hardware that physically manages power. Equipment to be integrated with the micro-grid controller must have an IP (Internet Protocol)-based network connection and a software "driver" must exist to translate data communications between the device and the controller.

  15. Protein local conformations arise from a mixture of Gaussian distributions

    Indian Academy of Sciences (India)

    Ashish V Tendulkar; Babatunde Ogunnaike; Pramod P Wangikar

    2007-08-01

    The classical approaches for protein structure prediction rely either on homology of the protein sequence with a template structure or on ab initio calculations for energy minimization. These methods suffer from disadvantages such as the lack of availability of homologous template structures or intractably large conformational search space, respectively. The recently proposed fragment library based approaches first predict the local structures, which can be used in conjunction with the classical approaches of protein structure prediction. The accuracy of the predictions is dependent on the quality of the fragment library. In this work, we have constructed a library of local conformation classes purely based on geometric similarity. The local conformations are represented using Geometric Invariants, properties that remain unchanged under transformations such as translation and rotation, followed by dimension reduction via principal component analysis. The local conformations are then modeled as a mixture of Gaussian probability distribution functions (PDF). Each one of the Gaussian PDF’s corresponds to a conformational class with the centroid representing the average structure of that class. We find 46 classes when we use an octapeptide as a unit of local conformation. The protein 3-D structure can now be described as a sequence of local conformational classes. Further, it was of interest to see whether the local conformations can be predicted from the amino acid sequences. To that end, we have analyzed the correlation between sequence features and the conformational classes.

  16. Local biogeomorphic feedbacks and macroscale drivers shape coastal wetland distributions

    Science.gov (United States)

    Braswell, A. E.; Heffernan, J. B.

    2016-12-01

    Recent models have demonstrated that lateral biogeomorphic processes are important for the persistence of coastal wetlands in the face of sea level rise and other anthropogenic pressures. Yet empirical studies of marsh ecomorphodynamics have largely focused on vertical accretion. Moreover, local vertical and lateral processes of marsh-building depend on external sediment supply and the wave energy environment, and thus are connected to macroscale characteristics such as estuarine morphology and watershed size. These broad scale drivers, combined with local biogeomorphic feedbacks within wetlands, determine wetland extent. Our goal is to understand the scales at which local biogeomorphic feedbacks and macroscale estuarine and watershed characteristics influence the distribution of coastal marshes. To that end, we examined the distribution of wetland extent and its potential watershed and estuarine drivers at multiple scales along the Atlantic and Gulf coasts, USA. Using existing GIS resources, we delineated extents of coastal wetlands, and generated proxies of sediment input, estuarine energy, and human alteration. We found that distributions of wetland extent were bi-modal at the finest scale of our analysis (approx. 1-100 km2), a finding that is consistent with theoretical models of local marsh feedbacks. At larger spatial scales, distributions of marsh extent were associated with both estuarine size and drainage ratio. These relationships indicate that sediment supply and erosion ultimately constrain the extent of marsh development and persistence, while local feedbacks operate at smaller scales. Our findings support and extend theory and observation at the scale of marsh platforms and lagoons, but also demonstrate the importance of macroscale watershed and estuarine characteristics for wetland establishment and persistence.

  17. Local distribution and thermal ecology of two intertidal fishes.

    Science.gov (United States)

    Pulgar, Jose M; Bozinovic, Francisco; Ojeda, F Patricio

    2005-02-01

    Geographic variability in the physiological attributes of widely distributed species can be a result of phenotypic plasticity or can reflect evolutionary responses to a particular habitat. In the field, we assessed thermal variability in low and high intertidal pools and the distribution of resident fish species Scartichthys viridis and transitory Girella laevifrons along this vertical intertidal gradient at three localities along the Chilean coast: Antofagasta (the northernmost and warmest habitat), Carrizal Bajo (central coast) and Las Cruces (the southernmost and coldest habitat). In the laboratory, we evaluated the thermal sensitivity of fish captured from each locality. The response to temperature was estimated as the frequency of opercular movements and as thermal selectivity in a gradient; the former being a indirect indicator of energy costs in a particular environment and the latter revealing differential occupation of habitat. Seawater temperature in intertidal pools was greatest at Antofagasta, and within each site was greatest in high intertidal pools. The two intertidal fish species showed opposite patterns of local distribution, with S. viridis primarily inhabiting the lower sectors of the intertidal zone, and G. laevifrons occupying the higher sectors of the intertidal zone. This pattern was consistent for all three localities. Locality was found to be a very important factor determining the frequency of opercular movement and thermal selectivity of both S. viridis and G. laevifrons. Our results suggest that S. viridis and G. laevifrons respond according to: (1) the thermal history of the habitat from which they came, and (2) the immediate physical conditions of their habitat. These results suggest local adaptation rather than plasticity in thermoregulatory and energetic mechanisms.

  18. Distributed localization for anchor-free sensor networks

    Institute of Scientific and Technical Information of China (English)

    Cui Xunxue; Shan Zhiguan; Liu Jianjun

    2008-01-01

    Geographic location of nodes is very useful in a sensor network. Previous localization algorithms assume that there exist some anchor nodes in this kind of network, and then other nodes are estimated to create their coordinates. Once there are not anchors to be deployed, those localization algorithms will be invalidated. Many papers in this field focus on anchor-based solutions. The use of anchors introduces many limitations, since anchors require external equipments such as global position system, cause additional power consumption. A novel positioning algorithm is proposed to use a virtual coordinate system based on a new concept-virtual anchor. It is executed in a distributed fashion according to the connectivity of a node and the measured distances to its neighbors. Both the adjacent member information and the ranging distance result are combined to generate the estimated position of a network, one of which is independently adopted for localization previously. At the position refinement stage the intermediate estimation of a node begins to be evaluated on its reliability for position mutation; thus the positioning optimization process of the whole network is avoided falling into a local optimal solution. Simulation results prove that the algorithm can resolve the distributed localization problem for anchor-free sensor networks, and is superior to previous methods in terms of its positioning capability under a variety of circumstances.

  19. Indirect linear locally distributed damping of coupled systems

    Directory of Open Access Journals (Sweden)

    Annick BEYRATH

    2004-11-01

    Full Text Available The aim of this paper is to prove indirect internal stabilization results for different coupled systems with linear locally distributed damping (coupled wave equations, wave equations with different speeds of propagation. In our case, a linear local damping term appears only in the first equation whereas no damping term is applied to the second one (this is indirect stabilization, see [11]. Using thepiecewise multiplier method we prove that the full system is stabilized and that the total energy of the solution of this system decays polynomially.

  20. Distributed localization using mobile beacons in wireless sensor networks

    Institute of Scientific and Technical Information of China (English)

    KUANG Xing-hong; SHAO Hui-he

    2007-01-01

    A new distributed node localization algorithm named mobile beacons-improved particle filter (MB-IPF) was proposed. In the algorithm, the mobile nodes equipped with globe position system (GPS) move around in the wireless sensor network (WSN) field based on the Gauss-Markov mobility model, and periodically broadcast the beacon messages. Each unknown node estimates its location in a fully distributed mode based on the received mobile beacons. The localization algorithm is based on the IPF and several refinements, including the proposed weighted centroid algorithm, the residual resampling algorithm, and the markov chain monte carlo (MCMC) method etc., which were also introduced for performance improvement. The simulation results show that our proposed algorithm is efficient for most applications.

  1. Distribution and ultrastructure of neurons in opossum piriform cortex displaying immunoreactivity to GABA and GAD and high-affinity tritiated GABA uptake

    Energy Technology Data Exchange (ETDEWEB)

    Haberly, L.B.; Hansen, D.J.; Feig, S.L.; Presto, S.

    1987-12-08

    GABAergic neurons have been identified in the piriform cortex of the opossum at light and electron microscopic levels by immunocytochemical localization of GABA and the GABA-synthesizing enzyme glutamic acid decarboxylase and by autoradiographic visualization of high-affinity /sup 3/H-GABA uptake. Four major neuron populations have been distinguished on the basis of soma size, shape, and segregation at specific depths and locations: large horizontal cells in layer Ia of the anterior piriform cortex, small globular cells with thin dendrites concentrated in layers Ib and II of the posterior piriform cortex, and multipolar and fusiform cells concentrated in the deep part of layer III in anterior and posterior parts of the piriform cortex and the subjacent endopiriform nucleus. All four populations were well visualized with both antisera, but the large layer Ia horizontal cells displayed only very light /sup 3/H-GABA uptake, thus suggesting a lack of local axon collaterals or lack of high-affinity GABA uptake sites. The large, ultrastructurally distinctive somata of layer Ia horizontal cells receive a very small number of symmetrical synapses; the thin, axonlike dendrites of small globular cells are exclusively postsynaptic and receive large numbers of both symmetrical and asymmetrical synapses, in contrast to somata which receive a small number of both types; and the deep multipolar and fusiform cells receive a highly variable number of symmetrical and asymmetrical synapses on somata and proximal dendrites. Labeled puncta of axon terminal dimensions were found in large numbers in the neuropil surrounding pyramidal cell somata in layer II and in the endopiriform nucleus. Moderately large numbers of labeled puncta were found in layer I at the depth of pyramidal cell apical dendrites with greater numbers in layer Ia at the depth of distal apical segments than in layer Ib.

  2. Climate Controls AM Fungal Distributions from Global to Local Scales

    Science.gov (United States)

    Kivlin, S. N.; Hawkes, C.; Muscarella, R.; Treseder, K. K.; Kazenel, M.; Lynn, J.; Rudgers, J.

    2016-12-01

    Arbuscular mycorrhizal (AM) fungi have key functions in terrestrial biogeochemical processes; thus, determining the relative importance of climate, edaphic factors, and plant community composition on their geographic distributions can improve predictions of their sensitivity to global change. Local adaptation by AM fungi to plant hosts, soil nutrients, and climate suggests that all of these factors may control fungal geographic distributions, but their relative importance is unknown. We created species distribution models for 142 AM fungal taxa at the global scale with data from GenBank. We compared climate variables (BioClim and soil moisture), edaphic variables (phosphorus, carbon, pH, and clay content), and plant variables using model selection on models with (1) all variables, (2) climatic variables only (including soil moisture) and (3) resource-related variables only (all other soil parameters and NPP) using the MaxEnt algorithm evaluated with ENMEval. We also evaluated whether drivers of AM fungal distributions were phylogenetically conserved. To test whether global correlates of AM fungal distributions were reflected at local scales, we then surveyed AM fungi in nine plant hosts along three elevation gradients in the Upper Gunnison Basin, Colorado, USA. At the global scale, the distributions of 55% of AM fungal taxa were affected by both climate and soil resources, whereas 16% were only affected by climate and 29% were only affected by soil resources. Even for AM fungi that were affected by both climate and resources, the effects of climatic variables nearly always outweighed those of resources. Soil moisture and isothermality were the main climatic and NPP and soil carbon the main resource related factors influencing AM fungal distributions. Distributions of closely related AM fungal taxa were similarly affected by climate, but not by resources. Local scale surveys of AM fungi across elevations confirmed that climate was a key driver of AM fungal

  3. Distributed Source Localization in Wireless Underground Sensor Networks

    CERN Document Server

    Chen, Hongyang; Wang, Chen

    2011-01-01

    Node localization plays an important role in many practical applications of wireless underground sensor networks (WUSNs), such as finding the locations of earthquake epicenters, underground explosions, and microseismic events in mines. It is more difficult to obtain the time-difference-of-arrival (TDOA) measurements in WUSNs than in terrestrial wireless sensor networks because of the unfavorable channel characteristics in the underground environment. The robust Chinese remainder theorem (RCRT) has been shown to be an effective tool for solving the phase ambiguity problem and frequency estimation problem in wireless sensor networks. In this paper, the RCRT is used to robustly estimate TDOA or range difference in WUSNs and therefore improves the ranging accuracy in such networks. After obtaining the range difference, distributed source localization algorithms based on a diffusion strategy are proposed to decrease the communication cost while satisfying the localization accuracy requirement. Simulation results c...

  4. Distributed Plume Source Localization Using Hierarchical Sensor Networks

    Institute of Scientific and Technical Information of China (English)

    KUANG Xing-hong; LIU Yu-qing; WU Yan-xiang; SHAO Hui-he

    2009-01-01

    A hierarchical wireless sensor networks (WSN) was proposed to estimate the plume source location. Such WSN can be of tremendous help to emergency personnel trying to protect people from terrorist attacks or responding to an accident. The entire surveillant field is divided into several small sub-regions. In each sub-region, the localization algorithm based on the improved particle filter (IPF) was performed to estimate the location. Some improved methods such as weighted centroid, residual resampling were introduced to the IPF algorithm to increase the localization performance. This distributed estimation method elirninates many drawbacks inherent with the traditional centralized optimization method. Simulation results show that localization algorithm is efficient far estimating the plume source location.

  5. Kinetics of functionalised carbon nanotube distribution in mouse brain after systemic injection: Spatial to ultra-structural analyses.

    Science.gov (United States)

    Wang, Julie T-W; Rubio, Noelia; Kafa, Houmam; Venturelli, Enrica; Fabbro, Chiara; Ménard-Moyon, Cécilia; Da Ros, Tatiana; Sosabowski, Jane K; Lawson, Alastair D; Robinson, Martyn K; Prato, Maurizio; Bianco, Alberto; Festy, Frederic; Preston, Jane E; Kostarelos, Kostas; Al-Jamal, Khuloud T

    2016-02-28

    Earlier studies proved the success of using chemically functionalised multi-walled carbon nanotubes (f-MWNTs) as nanocarriers to the brain. Little insight into the kinetics of brain distribution of f-MWNTs in vivo has been reported. This study employed a wide range of qualitative and quantitative techniques with the aim of shedding the light on f-MWNT's brain distribution following intravenous injection. γ-Scintigraphy quantified the uptake of studied radiolabelled f-MWNT in the whole brain parenchyma and capillaries while 3D-single photon emission computed tomography/computed tomography imaging and autoradiography illustrated spatial distribution within various brain regions. Raman and multiphoton luminescence together with transmission electron microscopy confirmed the presence of intact f-MWNT in mouse brain, in a label-free manner. The results evidenced the presence of f-MWNT in mice brain parenchyma, in addition to brain endothelium. Such information on the rate and extent of regional and cellular brain distribution is needed before further implementation into neurological therapeutics can be made. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  6. Local Environment Distribution in Ab Initio Liquid Water

    Science.gov (United States)

    Santra, Biswajit; Distasio, Robert A., Jr.; Car, Roberto

    2013-03-01

    We have analyzed the distribution of local environments in liquid water at ambient conditions and its inherent potential energy surface (IPES) based on state-of-the-art ab initio molecular dynamics simulations performed on 128 molecules implementing hybrid PBE0 exchange [PRB 79, 085102 (2009)] and van der Waals (vdW) interactions [PRL 102, 073005 (2009)]. The local environments of molecules are characterized in terms of the local structure index (LSI) [JCP 104, 7671 (1996)] which is able to distinguish high- and low-density molecular environments. In agreement with simulations based on model potentials, we find that the distribution of LSI is unimodal at ambient conditions and bimodal in the IPES, consistent with the existence of polymorphism in amorphous phases of water. At ambient conditions spatial LSI fluctuations extend up to ~7 Å and their dynamical correlation decays on a time scale of ~3 ps, as found for density fluctuations in a recent study [PRL 106, 037801 (2011)]. DOE: DE-SC0008626, DOE: DE-SC0005180, NSF: CHE-0956500

  7. Improved Distributed Particle Filter for Simultaneous Localization and Mapping

    Directory of Open Access Journals (Sweden)

    Mei Wu

    2013-07-01

    Full Text Available The Simultaneous localization and mapping (SLAM problem have become a focus of many researches on robot navigation. Generally the most widely used filter in SLAM problems are centralized filter. It is well known that SLAM based on conventional centralized filter must reconfigure the entire state vectors when the observation dimension changes, which cause an exponential growth in computation quantities and difficulties in isolate potential faults. In this paper, we proposed improved DPF distributed particle filter-SLAM in two aspects, in DPF-SLAM one centralized filter is divided into several distributed filters which reduce the computation quantities efficiently and avoid the necessary to reconfigure the entire state vectors in every step. First, we improved the important function of the local filters in distributed particle filter. By changed a set constant in the important function to an adaptive value, we improved the robustness of the system. Second, we propose an information fusion method that mixed the innovation method and the number of effective particles method, which combined the advantages of these two methods. The result of simulations shows that the algorithms we proposed improved the virtue of the DPF-SLAM system in isolate faults and enabled the system has a better tolerance and robustness.    

  8. LaRC local area networks to support distributed computing

    Science.gov (United States)

    Riddle, E. P.

    1984-01-01

    The Langley Research Center's (LaRC) Local Area Network (LAN) effort is discussed. LaRC initiated the development of a LAN to support a growing distributed computing environment at the Center. The purpose of the network is to provide an improved capability (over inteactive and RJE terminal access) for sharing multivendor computer resources. Specifically, the network will provide a data highway for the transfer of files between mainframe computers, minicomputers, work stations, and personal computers. An important influence on the overall network design was the vital need of LaRC researchers to efficiently utilize the large CDC mainframe computers in the central scientific computing facility. Although there was a steady migration from a centralized to a distributed computing environment at LaRC in recent years, the work load on the central resources increased. Major emphasis in the network design was on communication with the central resources within the distributed environment. The network to be implemented will allow researchers to utilize the central resources, distributed minicomputers, work stations, and personal computers to obtain the proper level of computing power to efficiently perform their jobs.

  9. Fiber optic distributed temperature sensing for fire source localization

    Science.gov (United States)

    Sun, Miao; Tang, Yuquan; Yang, Shuang; Sigrist, Markus W.; Li, Jun; Dong, Fengzhong

    2017-08-01

    A method for localizing a fire source based on a distributed temperature sensor system is proposed. Two sections of optical fibers were placed orthogonally to each other as the sensing elements. A tray of alcohol was lit to act as a fire outbreak in a cabinet with an uneven ceiling to simulate a real scene of fire. Experiments were carried out to demonstrate the feasibility of the method. Rather large fluctuations and systematic errors with respect to predicting the exact room coordinates of the fire source caused by the uneven ceiling were observed. Two mathematical methods (smoothing recorded temperature curves and finding temperature peak positions) to improve the prediction accuracy are presented, and the experimental results indicate that the fluctuation ranges and systematic errors are significantly reduced. The proposed scheme is simple and appears reliable enough to locate a fire source in large spaces.

  10. Functional brain networks develop from a "local to distributed" organization.

    Directory of Open Access Journals (Sweden)

    Damien A Fair

    2009-05-01

    Full Text Available The mature human brain is organized into a collection of specialized functional networks that flexibly interact to support various cognitive functions. Studies of development often attempt to identify the organizing principles that guide the maturation of these functional networks. In this report, we combine resting state functional connectivity MRI (rs-fcMRI, graph analysis, community detection, and spring-embedding visualization techniques to analyze four separate networks defined in earlier studies. As we have previously reported, we find, across development, a trend toward 'segregation' (a general decrease in correlation strength between regions close in anatomical space and 'integration' (an increased correlation strength between selected regions distant in space. The generalization of these earlier trends across multiple networks suggests that this is a general developmental principle for changes in functional connectivity that would extend to large-scale graph theoretic analyses of large-scale brain networks. Communities in children are predominantly arranged by anatomical proximity, while communities in adults predominantly reflect functional relationships, as defined from adult fMRI studies. In sum, over development, the organization of multiple functional networks shifts from a local anatomical emphasis in children to a more "distributed" architecture in young adults. We argue that this "local to distributed" developmental characterization has important implications for understanding the development of neural systems underlying cognition. Further, graph metrics (e.g., clustering coefficients and average path lengths are similar in child and adult graphs, with both showing "small-world"-like properties, while community detection by modularity optimization reveals stable communities within the graphs that are clearly different between young children and young adults. These observations suggest that early school age children and adults

  11. Subspace Learning via Local Probability Distribution for Hyperspectral Image Classification

    Directory of Open Access Journals (Sweden)

    Huiwu Luo

    2015-01-01

    Full Text Available The computational procedure of hyperspectral image (HSI is extremely complex, not only due to the high dimensional information, but also due to the highly correlated data structure. The need of effective processing and analyzing of HSI has met many difficulties. It has been evidenced that dimensionality reduction has been found to be a powerful tool for high dimensional data analysis. Local Fisher’s liner discriminant analysis (LFDA is an effective method to treat HSI processing. In this paper, a novel approach, called PD-LFDA, is proposed to overcome the weakness of LFDA. PD-LFDA emphasizes the probability distribution (PD in LFDA, where the maximum distance is replaced with local variance for the construction of weight matrix and the class prior probability is applied to compute the affinity matrix. The proposed approach increases the discriminant ability of the transformed features in low dimensional space. Experimental results on Indian Pines 1992 data indicate that the proposed approach significantly outperforms the traditional alternatives.

  12. Ultrastructural localization of atrial natriuretic peptide-synthesizing cells in rat stomach%心房钠尿肽合成细胞在大鼠胃的超微结构定位

    Institute of Scientific and Technical Information of China (English)

    潘理会; 李春辉; 杨宗伟

    2008-01-01

    BACKGROUND: Atrial natriuretic peptide (ANP)-synthesizing cells distribute in all over the body. However, very little is known about the morphological localization and the distribution characteristics of ANP-synthesizing cells in different regions of rat stomach. OBJECTIVE: To investigate the ultrastructural localization and distribution characteristics of ANP-synthesizing cells in rat stomach. DESIGN: Repeated measurement experiment. SETTING: Chengde Medical Collage, Chengde, Hebei Province, China. MATERIALS: This study was performed at the Laboratory for Institute of Chinese Materia Medica Immunology (provincial key laboratory), Chengde Medical College between October 2004 and July 2007. Eighteen adult Wistar rats of either gender, weighing 175-300 g, were provided by the Laboratory Animal Center of Chengde Medical College. The disposal of animals was conducted in accordance with ethical guidelines for the use and care of animals. ANP antibody and serum (Santa Cruz Biotechnology, Inc, USA), Protein A-15 nm colloidal gold labeled (Sino-American Biotechnology Company, China), CMIAS image analysis system (Beijing University of Aeronautics and Astronautics, China) and JEM-1200EX transmission election microscope (Japan) were used in the study. METHODS: After gastric and right atrial tissues (as a positive control in immanohistochemical staining for ANP-synthesizing cells) were fleshly excised from anesthetized Wistar rats, the specimens were longitudinally harvested along rat gastric cardiac region, gastric fundic mucosa and gastric pyloric region. Gastric tissue was performed immunohistochemical staining (for positive control) together with right atrial tissue, to observe the distribution characteristics of ANP-synthesizing cells in different regions of rat gastric tissue, and to localize ANP-synthesizing cells. The ultrastructural localization of ANP-synthesizing cells in the rat gastric mucosa was performed by postembedding immunoelectron microscopy. The area

  13. Teleparallel Energy-Momentum Distribution of Locally Rotationally Symmetric Spacetimes

    CERN Document Server

    Amir, M Jamil

    2014-01-01

    In this paper, we explore the energy-momentum distribution of locally rotationally symmetric (LRS) spacetimes in the context of the teleparallel theory of gravity by considering the three metrics, I, II and III, representing the whole class of LRS sapcetimes. In this regard, we use the teleparallel versions of the Einstein, Landau-Lifshitz, Bergmann-Thomson, and M$\\ddot{o}$ller prescriptions. The results show that the momentum density components for the Einstein, Bergmann-Thomson, and M$\\ddot{o}$ller prescriptions turn out to be same in all cases of the metrics I, II and III, but are different from those of the Landau- Lifshitz prescription, while the energy components remain the same for these three prescriptions only in all possible cases of the metrics I and II. We mention here that the M$\\ddot{o}$ller energy-momentum distribution is independent of the coupling constant $\\lambda$; that is, these results are valid for any teleparallel models.

  14. Distributed SLAM using improved particle filter for mobile robot localization.

    Science.gov (United States)

    Pei, Fujun; Wu, Mei; Zhang, Simin

    2014-01-01

    The distributed SLAM system has a similar estimation performance and requires only one-fifth of the computation time compared with centralized particle filter. However, particle impoverishment is inevitably because of the random particles prediction and resampling applied in generic particle filter, especially in SLAM problem that involves a large number of dimensions. In this paper, particle filter use in distributed SLAM was improved in two aspects. First, we improved the important function of the local filters in particle filter. The adaptive values were used to replace a set of constants in the computational process of importance function, which improved the robustness of the particle filter. Second, an information fusion method was proposed by mixing the innovation method and the number of effective particles method, which combined the advantages of these two methods. And this paper extends the previously known convergence results for particle filter to prove that improved particle filter converges to the optimal filter in mean square as the number of particles goes to infinity. The experiment results show that the proposed algorithm improved the virtue of the DPF-SLAM system in isolate faults and enabled the system to have a better tolerance and robustness.

  15. Distributed SLAM Using Improved Particle Filter for Mobile Robot Localization

    Directory of Open Access Journals (Sweden)

    Fujun Pei

    2014-01-01

    Full Text Available The distributed SLAM system has a similar estimation performance and requires only one-fifth of the computation time compared with centralized particle filter. However, particle impoverishment is inevitably because of the random particles prediction and resampling applied in generic particle filter, especially in SLAM problem that involves a large number of dimensions. In this paper, particle filter use in distributed SLAM was improved in two aspects. First, we improved the important function of the local filters in particle filter. The adaptive values were used to replace a set of constants in the computational process of importance function, which improved the robustness of the particle filter. Second, an information fusion method was proposed by mixing the innovation method and the number of effective particles method, which combined the advantages of these two methods. And this paper extends the previously known convergence results for particle filter to prove that improved particle filter converges to the optimal filter in mean square as the number of particles goes to infinity. The experiment results show that the proposed algorithm improved the virtue of the DPF-SLAM system in isolate faults and enabled the system to have a better tolerance and robustness.

  16. ULTRASTRUCTURAL LOCALIZATION AND EFFECT OF LEAD ON MINERAL ELEMENTS IN CALLUS OF ALTERNANTHERA PHILOXEROIDES%Pb在水花生愈伤组织中的超微定位及对矿质元素的影响

    Institute of Scientific and Technical Information of China (English)

    王娟; 张乐乐; 康宜宁; 施国新

    2012-01-01

    B在各亚细胞组分中均表现出先升后降;Cu在前两个组分中总体呈上升趋势,可溶性部分中则是先升后降;Si在细胞壁中逐渐减少,细胞器中呈先升后降的趋势,而可溶性部分中无法测出.可见,Pb打乱了各亚细胞组分中离子平衡,导致愈伤组织正常生理活动紊乱,这些都是Pb毒害水花生愈伤组织的主要表现.%Heavy metal pollution of water bodies has become an increasingly serious environmental problem. Understand the principles of heavy metal contamination and heavy metals in water treatment have become a topic that must be addressed. Heavy metals can cause serious health hazards to animals and humans through the food chain due to the refractory, easy accumulation, toxicity and other characteristics. Therefore, much attention has been devoted to the studies on the mechanisms of heavy metal tolerance in plants and how to improve heavy metal tolerance of plants. Although antioxidative reactions of plants subjected to Pb2+ have been studied by several authors, there are few reports on the research of callus response to heavy metals. In view of this, callus of Alternanthera philoxeroides was cultured to overcome the uncontrollability of light, temperature, moisture and plant growth and development in the natural state, so that the experimental data is more repeated and scientific. Callus of Alternanthera philoxeroides stems was cultured in 1/2 MS medium including 6-BA (3.0 mg/L) and NAA (0.2 mg/L) after the disinfection of 70% ethanol 30s, 5% sodium hypochlorite 10min and 0.1% mercuric chloride 10min, was used as experimental material, and Pb2+ was selected as the stress factor. The toxic effects of Pb gradient concentrations (0, 0.2, 0.4, 0.8 and 1.6 mmol/L) on the accumulation, subcellular distribution, ultrastructural localization and mineral elements were studied. The results indicated that, with the increasing of Pb concentration, (1) Alternanthera philoxeroides callus was able to accumulate lead, the bioconcen

  17. Generating the Local Oscillator "Locally" in Continuous-Variable Quantum Key Distribution Based on Coherent Detection

    Science.gov (United States)

    Qi, Bing; Lougovski, Pavel; Pooser, Raphael; Grice, Warren; Bobrek, Miljko

    2015-10-01

    Continuous-variable quantum key distribution (CV-QKD) protocols based on coherent detection have been studied extensively in both theory and experiment. In all the existing implementations of CV-QKD, both the quantum signal and the local oscillator (LO) are generated from the same laser and propagate through the insecure quantum channel. This arrangement may open security loopholes and limit the potential applications of CV-QKD. In this paper, we propose and demonstrate a pilot-aided feedforward data recovery scheme that enables reliable coherent detection using a "locally" generated LO. Using two independent commercial laser sources and a spool of 25-km optical fiber, we construct a coherent communication system. The variance of the phase noise introduced by the proposed scheme is measured to be 0.04 (rad2 ), which is small enough to enable secure key distribution. This technology also opens the door for other quantum communication protocols, such as the recently proposed measurement-device-independent CV-QKD, where independent light sources are employed by different users.

  18. 稻秸皮层硅物质的分布及超微构造%Distribution and ultrastructure of silica on rice straw surface

    Institute of Scientific and Technical Information of China (English)

    潘明珠; 杜俊; 甘习华; 吕歆悦

    2016-01-01

    electron microscopy with energy dispersive spectra (SEM-EDS). The ultrastructure of SiO2derived from rice straw tissues was measured with the X-ray diffraction (XRD). The results of SiO2 content measurement showed that the silicon content of sheath (7.2%) was higher than that of stem (2.7%). The SEM-EDS results showed that the silicon content was 12.65%, 0.22% and 1.14% in exterior, middle and interior sheath, respectively. And the silicon content was 8.98%, 0.39% and 0.52% in exterior, middle and interior stem, respectively. Considering total SiO2 content of sheath and stem, silica was mainly distributed in the exterior surface of sheath and stem. Furthermore, silica distributed in the exterior surface of sheath mainly exhibited small granular matter, accompanied with bigger granular matter and hair-like trichome. The distribution of silica in the exterior surface of stem was more regular, however, the content of bigger granular matter and hair-like trichome was further decreased. The silica in small granular matter with the diameter of 1μm mainly exhibited spherical and dumbbell-shaped. The XRD results showed that the crystal phase of rice straw exhibited Cellulose I, with crystallinity index of 55.3%, 59.0%, 47.8% and 57.4% in sheath, stem, node and ear, respectively. The crystallite size within them was 2.10, 2.13, 1.36 and 2.22 nm, respectively. Moreover, the SiO2 derived from rice straw exhibited amorphous.%为了探索稻秸表面硅物质的分布和超微构造,该文以稻秸各皮层的硅物质作为研究对象,采用扫描电子显微镜-能谱分析(scanning electric microscopy coupled with energy-dispersive spectroscopy,SEM-EDS)和X射线衍射仪(X-ray diffraction,XRD)探讨稻秸各皮层硅物质的分布及构造。SEM-EDS研究表明,硅物质主要分布在叶鞘、茎秆的外层,且叶鞘中硅物质的含量高于茎秆。叶鞘外层的硅物质主要以小颗粒物存在、夹杂少量大颗粒物和毛状物。茎秆外层

  19. Heterogeneous Distribution of Fetal Microchimerism in Local Breast Cancer Environment.

    Directory of Open Access Journals (Sweden)

    Dragos Nemescu

    Full Text Available Fetal cells enter maternal circulation during pregnancy and persist in the woman's body for decades, achieving a form of physiological microchimerism. These cells were also evidenced in tumors. We investigated the frequency and concentration of fetal microchimerism in the local breast cancer environment. From 19 patients with confirmed breast neoplasia, after breast surgical resection, we collected three fresh specimens from the tumor core, breast tissue at tumor periphery, and adjacent normal breast tissue. The presence of male DNA was analyzed with a quantitative PCR assay for the sex determining region gene (SRY gene. In the group of women who had given birth to at least one son, we detected fetal microchimerism in 100% of samples from tumors and their periphery and in 64% (9 of 14 of those from normal breast tissue. The tissues from the tumor and its periphery carry a significantly increased number of SRY copies compared to its neighboring common breast tissue (p = 0.005. The median of the normalized SRY-signal was about 77 (range, 3.2-21467 and 14-fold (range, 1.3-2690 greater in the tumor and respectively in the periphery than in the normal breast tissue. In addition, the relative expression of the SRY gene had a median 5.5 times larger in the tumor than in its periphery (range, 1.1-389.4. We found a heterogeneous distribution of fetal microchimerism in breast cancer environment. In women with sons, breast neoplasia harbors male cells at significantly higher levels than in peripheral and normal breast tissue.

  20. Heterogeneous Distribution of Fetal Microchimerism in Local Breast Cancer Environment.

    Science.gov (United States)

    Nemescu, Dragos; Ursu, Ramona Gabriela; Nemescu, Elena Roxana; Negura, Lucian

    2016-01-01

    Fetal cells enter maternal circulation during pregnancy and persist in the woman's body for decades, achieving a form of physiological microchimerism. These cells were also evidenced in tumors. We investigated the frequency and concentration of fetal microchimerism in the local breast cancer environment. From 19 patients with confirmed breast neoplasia, after breast surgical resection, we collected three fresh specimens from the tumor core, breast tissue at tumor periphery, and adjacent normal breast tissue. The presence of male DNA was analyzed with a quantitative PCR assay for the sex determining region gene (SRY) gene. In the group of women who had given birth to at least one son, we detected fetal microchimerism in 100% of samples from tumors and their periphery and in 64% (9 of 14) of those from normal breast tissue. The tissues from the tumor and its periphery carry a significantly increased number of SRY copies compared to its neighboring common breast tissue (p = 0.005). The median of the normalized SRY-signal was about 77 (range, 3.2-21467) and 14-fold (range, 1.3-2690) greater in the tumor and respectively in the periphery than in the normal breast tissue. In addition, the relative expression of the SRY gene had a median 5.5 times larger in the tumor than in its periphery (range, 1.1-389.4). We found a heterogeneous distribution of fetal microchimerism in breast cancer environment. In women with sons, breast neoplasia harbors male cells at significantly higher levels than in peripheral and normal breast tissue.

  1. Function-related adaptations of ultrastructure, mineral phase distribution and mechanical properties in the incisive cuticle of mandibles of Porcellio scaber Latreille, 1804.

    Science.gov (United States)

    Huber, Julia; Fabritius, Helge-Otto; Griesshaber, Erika; Ziegler, Andreas

    2014-10-01

    In terrestrial isopods the mandibles consist of a corpus carrying strong muscle tissue, and a pars incisiva (PI) that cuts dry leaves into smaller ingestible pieces. We studied the cuticle of the PI of Porcellio scaber in order to understand region-dependent differences in its ultrastructure, composition, and the resulting mechanical properties, employing several microscopic and analytical techniques as well as nanoindentation experiments. The cuticle of the incisive tip is not mineralized and consists of an unusually thick epicuticle containing thin fibrils, two subjacent cuticular layers, and a central core containing fibrils of different orientation, either longitudinal or circumferential. A thick epicuticle of the middle region just behind the tip projects long epicuticular extensions into the subjacent endocuticle, likely to prevent delamination. A distinct exocuticular layer is lacking in the middle region. Most chitin-protein fibrils within the endocuticle are oriented in parallel pointing towards the tip. Surprisingly, the middle region is mineralized by amorphous calcium phosphate (ACP) only. Near the base, ACP is successively replaced by amorphous calcium carbonate and calcite is restricted to a distal layer in the base. At the transition between middle and base, the epicuticle forms a hybrid material containing fibrils of the exocuticle. Nanoindentation experiments reveal an increase of the stiffness and hardness from the tip towards the base and significantly higher values on transversal in comparison to longitudinal planes. The results suggest that ultrastructure and composition are adapted for conveying high forces from a rather thin cutting edge to the stable base of the PI.

  2. Ultrastructural localization of extracellular matrix proteins of the lymph node cortex: evidence supporting the reticular network as a pathway for lymphocyte migration

    Directory of Open Access Journals (Sweden)

    Sobocinski Gregg P

    2010-08-01

    Full Text Available Abstract Background The lymph node (LN is a crossroads of blood and lymphatic vessels allowing circulating lymphocytes to efficiently recognize foreign molecules displayed on antigen presenting cells. Increasing evidence indicates that after crossing high endothelial venules, lymphocytes migrate within the node along the reticular network (RN, a scaffold of fibers enwrapped by fibroblastic reticular cells (FRC. Light microscopy has shown that the RN contains specific extracellular matrix (ECM proteins, which are putative molecular "footholds" for migration, and are known ligands for lymphocyte integrin adhesion receptors. Results To investigate whether ECM proteins of the RN are present on the outer surface of the FRC and are thus accessible to migrating lymphocytes, ultrastructural immunohistochemical staining of cynomolgus monkey LN was performed using antibodies to human ECM proteins that were successfully employed at the light microscopic level. The fibrillar collagens I and III were observed primarily within the reticular network fibers themselves. In contrast, the matrix proteins laminin, fibronectin, collagen IV, and tenascin were observed within the reticular fibers and also on the outer membrane surface of the FRC. Conclusions These findings suggest a molecular basis for how the RN functions as a pathway for lymphocyte migration within the lymph node.

  3. Ultrastructural localization of unique neurosecretory granules in the corpora cardiaca of the stable fly, Stomoxys calcitrans, and the tsetse fly, Glossina morsitans.

    Science.gov (United States)

    Meola, S M; Pendleton, M W; Langley, P A; Lovering, S L

    1999-05-01

    Ultrastructural analysis of the corpora cardiaca of the stable fly, Stomoxys calcitrans, and the tsetse fly, Glossina morsitans, revealed the presence of elementary neurosecretory granules (ENG) unique to the intrinsic neurosecretory cells (INC) of these species. In addition to electron-dense spheres, the INC of the corpus species. In addition to electron-dense spheres, the INC of the corpus cardiacum of the stable fly contain electrondense angular granules, either square or rectangular in shape, while the INC of the tsetse fly contain electron-dense spindle-shaped ENG. The distinctive granules of these INC can be traced within nerves to their sites of storage and release, eliminating the need for labeling with artificial probes. Although the INC of the corpus cardiacum of most species have been found to be fuchsinophilic, neither the INC of the stable fly nor the tsetse fly are aldehyde-fuchsinophilic. These peptigenic cells offer neuroendocrinologists a unique opportunity to study the physiology and biochemistry of neurosecretory cells.

  4. Scalable Distributed Change Detection from Astronomy Data Streams using Local, Asynchronous Eigen Monitoring Algorithms

    Data.gov (United States)

    National Aeronautics and Space Administration — This paper considers the problem of change detection using local distributed eigen monitoring algorithms for next generation of astronomy petascale data pipelines...

  5. Experimental study of the relationship between local particle-size distributions and local ordering in random close packing.

    Science.gov (United States)

    Kurita, Rei

    2015-12-01

    We experimentally study the structural properties of a sediment of size distributed colloids. By determining each particle size using a size estimation algorithm, we are able to investigate the relationship between local environment and local ordering. Our results show that ordered environments of particles tend to generate where the local particle-size distribution is within 5%. In addition, we show that particles whose size is close to the average size have 12 coordinate neighbors, which matches the coordination number of the fcc and hcp crystals. On the other hand, bcc structures are observed around larger particles. Our results represent experiments to show a size dependence of the specific ordering in colloidal systems.

  6. Exposure and post-exposure effects of endosulfan on Bufo bufo tadpoles: morpho-histological and ultrastructural study on epidermis and iNOS localization.

    Science.gov (United States)

    Bernabò, Ilaria; Guardia, Antonello; La Russa, Daniele; Madeo, Giuseppe; Tripepi, Sandro; Brunelli, Elvira

    2013-10-15

    Endosulfan is a persistent organic pollutant (POP) that has lethal and sublethal effects on non-target organisms, including amphibians. In a laboratory study, we investigated direct and post-exposure effects of endosulfan on Bufo bufo tadpoles. For this purpose we exposed the tadpoles to a single short-term contamination event (96 h) at an environmentally-realistic concentration (200 μg endosulfan/L). This was followed by a recovery period of 10 days when the experimental animals were kept in pesticide-free water. The endpoints were assessed in terms of mortality, incidence of deformity, effects on behavior, and the morpho-functional features of the epidermis. We found that a short-term exposure to the tested concentration of endosulfan did not cause mortality but induced severe sublethal effects, such as hyperactivity, convulsions, and axis malformations. Following relocation to a pesticide-free environment, we noted two types of response within the experimental sample, in terms of morphological and behavioral traits. Moreover, by using both ultrastructural and a morpho-functional approach, we found that a short-term exposure to endosulfan negatively affected the amphibian epidermis. We also observed several histo-pathological alterations: increased mucous secretion, an increase in intercellular spaces and extensive cell degeneration, together with the induction of an inducible isoform of nitric oxide synthase (iNOS). Following the post-exposure period, we found large areas of epidermis in which degeneration phenomena were moderate or absent, as well as a further increase in iNOS immunoreactivity. Thus, after 10 days in a free-pesticide environment, the larval epidermis was able to partially replace elements that had been compromised due to a physiological and/or a pathological response to the pesticide. These results highlight the need for both exposure and post-exposure experiments, when attempting to assess pollutant effects.

  7. Data Locality via Coordinated Caching for Distributed Processing

    Science.gov (United States)

    Fischer, M.; Kuehn, E.; Giffels, M.; Jung, C.

    2016-10-01

    To enable data locality, we have developed an approach of adding coordinated caches to existing compute clusters. Since the data stored locally is volatile and selected dynamically, only a fraction of local storage space is required. Our approach allows to freely select the degree at which data locality is provided. It may be used to work in conjunction with large network bandwidths, providing only highly used data to reduce peak loads. Alternatively, local storage may be scaled up to perform data analysis even with low network bandwidth. To prove the applicability of our approach, we have developed a prototype implementing all required functionality. It integrates seamlessly into batch systems, requiring practically no adjustments by users. We have now been actively using this prototype on a test cluster for HEP analyses. Specifically, it has been integral to our jet energy calibration analyses for CMS during run 2. The system has proven to be easily usable, while providing substantial performance improvements. Since confirming the applicability for our use case, we have investigated the design in a more general way. Simulations show that many infrastructure setups can benefit from our approach. For example, it may enable us to dynamically provide data locality in opportunistic cloud resources. The experience we have gained from our prototype enables us to realistically assess the feasibility for general production use.

  8. Quantum localization of chaotic eigenstates and the level spacing distribution

    Science.gov (United States)

    Batistić, Benjamin; Robnik, Marko

    2013-11-01

    The phenomenon of quantum localization in classically chaotic eigenstates is one of the main issues in quantum chaos (or wave chaos), and thus plays an important role in general quantum mechanics or even in general wave mechanics. In this work we propose two different localization measures characterizing the degree of quantum localization, and study their relation to another fundamental aspect of quantum chaos, namely the (energy) spectral statistics. Our approach and method is quite general, and we apply it to billiard systems. One of the signatures of the localization of chaotic eigenstates is a fractional power-law repulsion between the nearest energy levels in the sense that the probability density to find successive levels on a distance S goes like ∝Sβ for small S, where 0≤β≤1, and β=1 corresponds to completely extended states. We show that there is a clear functional relation between the exponent β and the two different localization measures. One is based on the information entropy and the other one on the correlation properties of the Husimi functions. We show that the two definitions are surprisingly linearly equivalent. The approach is applied in the case of a mixed-type billiard system [M. Robnik, J. Phys. A: Math. Gen.JPHAC50305-447010.1088/0305-4470/16/17/014 16, 3971 (1983)], in which the separation of regular and chaotic eigenstates is performed.

  9. Stimulated luminescence emission from localized recombination in randomly distributed defects

    DEFF Research Database (Denmark)

    Jain, Mayank; Guralnik, Benny; Andersen, Martin Thalbitzer

    2012-01-01

    We present a new kinetic model describing localized electronic recombination through the excited state of the donor (d) to an acceptor (a) centre in luminescent materials. In contrast to the existing models based on the localized transition model (LTM) of Halperin and Braner (1960 Phys. Rev. 117...... that evolves only in the temporal domain. An excellent agreement is observed between thermally and optically stimulated luminescence (TL and OSL) results produced from the two models. In comparison to the first-order kinetic behaviour of the LTM of Halperin and Braner (1960 Phys. Rev. 117 408–15), our model...... results in a highly asymmetric TL peak; this peak can be understood to derive from a continuum of several first-order TL peaks. Our model also shows an extended power law behaviour for OSL (or prompt luminescence), which is expected from localized recombination mechanisms in materials with random...

  10. Scaling up from epidemiology to biogeography: local infection patterns predict geographical distribution in fish parasites

    NARCIS (Netherlands)

    Poulin, R.; Blanar, C.A.; Thieltges, D.W.; Marcogliese, D.J.

    2012-01-01

    Aim We investigated how the spatial distribution of parasites, measured as either their geographical range size or their frequency of occurrence among localities, relates to either their average local abundance or the variance in their abundance among localities where they occur. Location We used da

  11. Localization of Distributed Fiber Sensor Employing a Sub-Ring

    Institute of Scientific and Technical Information of China (English)

    Wei-Min Chen; Yuan-Yuan Xie; Peng Zhang; Lei Lin

    2008-01-01

    A simple distributed optical fiber sensing system used to monitor vibration signal has an additional sub-loop coupled with main ring by a 3 dB coupler. This paper compares three outputting interfered beams, each of them travels in the sub-ring 0, 1, 2 times, separately. Using the simultaneous equations produced by those three outputs, we find the relation between the interference lights and vibration signal's characteristics, such as frequency, amplitude and position. Through simplifying and calculating, the vibration position can be obtained finally.

  12. Supervisor localization a top-down approach to distributed control of discrete-event systems

    CERN Document Server

    Cai, Kai

    2016-01-01

    This monograph presents a systematic top-down approach to distributed control synthesis of discrete-event systems (DES). The approach is called supervisor localization; its essence is the allocation of external supervisory control action to individual component agents as their internal control strategies. The procedure is: first synthesize a monolithic supervisor, to achieve globally optimal and nonblocking controlled behavior, then decompose the monolithic supervisor into local controllers, one for each agent. The collective behavior of the resulting local controllers is identical to that achieved by the monolithic supervisor. The basic localization theory is first presented in the Ramadge–Wonham language-based supervisory control framework, then demonstrated with distributed control examples of multi-robot formations, manufacturing systems, and distributed algorithms. An architectural approach is adopted to apply localization to large-scale DES; this yields a heterarchical localization procedure, which is...

  13. Localized bedrock aquifer distribution explains discharge from a headwater catchment

    Science.gov (United States)

    Kosugi, Ken'ichirou; Fujimoto, Masamitsu; Katsura, Shin'ya; Kato, Hiroyuki; Sando, Yoshiki; Mizuyama, Takahisa

    2011-07-01

    Understanding a discharge hydrograph is one of the leading interests in catchment hydrology. Recent research has provided credible information on the importance of bedrock groundwater on discharge hydrographs from headwater catchments. However, intensive monitoring of bedrock groundwater is rare in mountains with steep topography. Hence, how bedrock groundwater controls discharge from a steep headwater catchment is in dispute. In this study, we conducted long-term hydrological observations using densely located bedrock wells in a headwater catchment underlain by granitic bedrock. The catchment has steep topography affected by diastrophic activities. Results showed a fairly regionalized distribution of bedrock aquifers within a scale of tens of meters, consisting of upper, middle, and lower aquifers, instead of a gradual and continuous decline in water level from ridge to valley bottom. This was presumably attributable to the unique bedrock structure; fault lines developed in the watershed worked to form divides between the bedrock aquifers. Spatial expanse of each aquifer and the interaction among aquifers were key factors to explain gentle and considerable variations in the base flow discharge and triple-peak discharge responses of the observed hydrograph. A simple model was developed to simulate the discharge hydrograph, which computed each of the contributions from the soil mantle groundwater, from the lower aquifer, and from the middle aquifer to the discharge. The modeling results generally succeeded in reproducing the observed hydrograph. Thus, this study demonstrated that understanding regionalized bedrock aquifer distribution is pivotal for explaining discharge hydrograph from headwater catchments that have been affected by diastrophic activities.

  14. An Autonomous Distributed Fault-Tolerant Local Positioning System

    Science.gov (United States)

    Malekpour, Mahyar R.

    2017-01-01

    We describe a fault-tolerant, GPS-independent (Global Positioning System) distributed autonomous positioning system for static/mobile objects and present solutions for providing highly-accurate geo-location data for the static/mobile objects in dynamic environments. The reliability and accuracy of a positioning system fundamentally depends on two factors; its timeliness in broadcasting signals and the knowledge of its geometry, i.e., locations and distances of the beacons. Existing distributed positioning systems either synchronize to a common external source like GPS or establish their own time synchrony using a scheme similar to a master-slave by designating a particular beacon as the master and other beacons synchronize to it, resulting in a single point of failure. Another drawback of existing positioning systems is their lack of addressing various fault manifestations, in particular, communication link failures, which, as in wireless networks, are increasingly dominating the process failures and are typically transient and mobile, in the sense that they typically affect different messages to/from different processes over time.

  15. Distribution and localization of histamine in bovine and rabbit eye.

    Science.gov (United States)

    Nowak, J Z; Nawrocki, J; Maslinski, C

    1984-04-01

    Histamine (HI) is present in various structures of the bovine and rabbit eye (retina, choroid, sclera) and in the optic nerve of both species. The amine levels in particular structures of either cow or rabbit are highly differentiated, as well as profile of HI distribution which differs markedly between both species, except only the retina structure (HI levels were between 70-80 ng per g tissue). In the bovine retina HI is stored in non mast cell compartment, while in the optic nerve at least 50% of the amine is of mast cell origin. Approximately 90% of the retinal HI was recovered in the P1 subcellular fraction. HI in the bovine retina is metabolized by methylation. The data are discussed in terms of a possible physiological role of HI in the retina.

  16. Level set segmentation of brain magnetic resonance images based on local Gaussian distribution fitting energy.

    Science.gov (United States)

    Wang, Li; Chen, Yunjie; Pan, Xiaohua; Hong, Xunning; Xia, Deshen

    2010-05-15

    This paper presents a variational level set approach in a multi-phase formulation to segmentation of brain magnetic resonance (MR) images with intensity inhomogeneity. In our model, the local image intensities are characterized by Gaussian distributions with different means and variances. We define a local Gaussian distribution fitting energy with level set functions and local means and variances as variables. The means and variances of local intensities are considered as spatially varying functions. Therefore, our method is able to deal with intensity inhomogeneity without inhomogeneity correction. Our method has been applied to 3T and 7T MR images with promising results.

  17. Clumps and streams in the local dark matter distribution.

    Science.gov (United States)

    Diemand, J; Kuhlen, M; Madau, P; Zemp, M; Moore, B; Potter, D; Stadel, J

    2008-08-01

    In cold dark matter cosmological models, structures form and grow through the merging of smaller units. Numerical simulations have shown that such merging is incomplete; the inner cores of haloes survive and orbit as 'subhaloes' within their hosts. Here we report a simulation that resolves such substructure even in the very inner regions of the Galactic halo. We find hundreds of very concentrated dark matter clumps surviving near the solar circle, as well as numerous cold streams. The simulation also reveals the fractal nature of dark matter clustering: isolated haloes and subhaloes contain the same relative amount of substructure and both have cusped inner density profiles. The inner mass and phase-space densities of subhaloes match those of recently discovered faint, dark-matter-dominated dwarf satellite galaxies, and the overall amount of substructure can explain the anomalous flux ratios seen in strong gravitational lenses. Subhaloes boost gamma-ray production from dark matter annihilation by factors of 4 to 15 relative to smooth galactic models. Local cosmic ray production is also enhanced, typically by a factor of 1.4 but by a factor of more than 10 in one per cent of locations lying sufficiently close to a large subhalo. (These estimates assume that the gravitational effects of baryons on dark matter substructure are small.).

  18. Distributed thin film sensor array for damage detection and localization

    Science.gov (United States)

    Downey, Austin; Laflamme, Simon; Ubertini, Filippo

    2016-04-01

    The authors have developed a capacitive-based thin film sensor for monitoring strain on mesosurfaces. Arranged in a network configuration, the sensing system is analogous to a biological skin, where local strain can be monitored over a global area. The measurement principle is based on a measurable change in capacitance provoked by strain. In the case of bidirectional in-plane strain, the sensor output contains the additive measurement of both principal strain components. In this paper, we present an algorithm for retrieving unidirectional strain from the bidirectional measurements of the capacitive-based thin film sensor when place in a hybrid dense sensor network with state-of-the-art unidirectional strain sensors. The algorithm leverages the advantages of a hybrid dense network for application of the thin film sensor to reconstruct the surface strain maps. A bidirectional shape function is assumed, and it is differentiated to obtain expressions for planar strain. A least squares estimator (LSE) is used to reconstruct the planar strain map from the networks measurements, after the system's boundary conditions have been enforced in the model. The coefficients obtained by the LSE can be used to reconstruct the estimated strain map. Results from numerical simulations and experimental investigations show good performance of the algorithm.

  19. Metallicity Distribution Functions of Four Local Group dwarf galaxies

    CERN Document Server

    Ross, Teresa L; Saha, Abhijit; Anthony-Twarog, Barbara J

    2015-01-01

    We present stellar metallicities in Leo I, Leo II, IC 1613, and Phoenix dwarf galaxies derived from medium (F390M) and broad (F555W, F814W) band photometry using the Wide Field Camera 3 (WFC3) instrument aboard the Hubble Space Telescope. We measured metallicity distribution functions (MDFs) in two ways, 1) matching stars to isochrones in color-color diagrams, and 2) solving for the best linear combination of synthetic populations to match the observed color-color diagram. The synthetic technique reduces the effect of photometric scatter, and produces MDFs 30-50 % narrower than the MDFs produced from individually matched stars. We fit the synthetic and individual MDFs to analytical chemical evolution models (CEM) to quantify the enrichment and the effect of gas flows within the galaxies. Additionally, we measure stellar metallicity gradients in Leo I and II. For IC 1613 and Phoenix our data do not have the radial extent to confirm a metallicity gradient for either galaxy. We find the MDF of Leo I (dwarf spher...

  20. METALLICITY DISTRIBUTION FUNCTIONS OF FOUR LOCAL GROUP DWARF GALAXIES

    Energy Technology Data Exchange (ETDEWEB)

    Ross, Teresa L.; Holtzman, Jon [Department of Astronomy, New Mexico State University, P.O. Box 30001, MSC 4500, Las Cruces, NM 88003-8001 (United States); Saha, Abhijit [NOAO, 950 Cherry Avenue, Tucson, AZ 85726-6732 (United States); Anthony-Twarog, Barbara J., E-mail: rosst@nmsu.edu, E-mail: holtz@nmsu.edu, E-mail: bjat@ku.edu [Department of Physics and Astronomy, University of Kansas, Lawrence, KS 66045-7582 (United States)

    2015-06-15

    We present stellar metallicities in Leo I, Leo II, IC 1613, and Phoenix dwarf galaxies derived from medium (F390M) and broad (F555W, F814W) band photometry using the Wide Field Camera 3 instrument on board the Hubble Space Telescope. We measured metallicity distribution functions (MDFs) in two ways, (1) matching stars to isochrones in color–color diagrams and (2) solving for the best linear combination of synthetic populations to match the observed color–color diagram. The synthetic technique reduces the effect of photometric scatter and produces MDFs 30%–50% narrower than the MDFs produced from individually matched stars. We fit the synthetic and individual MDFs to analytical chemical evolution models (CEMs) to quantify the enrichment and the effect of gas flows within the galaxies. Additionally, we measure stellar metallicity gradients in Leo I and II. For IC 1613 and Phoenix our data do not have the radial extent to confirm a metallicity gradient for either galaxy. We find the MDF of Leo I (dwarf spheroidal) to be very peaked with a steep metal-rich cutoff and an extended metal-poor tail, while Leo II (dwarf spheroidal), Phoenix (dwarf transition), and IC 1613 (dwarf irregular) have wider, less peaked MDFs than Leo I. A simple CEM is not the best fit for any of our galaxies; therefore we also fit the “Best Accretion Model” of Lynden-Bell. For Leo II, IC 1613, and Phoenix we find similar accretion parameters for the CEM even though they all have different effective yields, masses, star formation histories, and morphologies. We suggest that the dynamical history of a galaxy is reflected in the MDF, where broad MDFs are seen in galaxies that have chemically evolved in relative isolation and narrowly peaked MDFs are seen in galaxies that have experienced more complicated dynamical interactions concurrent with their chemical evolution.

  1. A Local Asynchronous Distributed Privacy Preserving Feature Selection Algorithm for Large Peer-to-Peer Networks

    Data.gov (United States)

    National Aeronautics and Space Administration — In this paper we develop a local distributed privacy preserving algorithm for feature selection in a large peer-to-peer environment. Feature selection is often used...

  2. A Local Scalable Distributed EM Algorithm for Large P2P Networks

    Data.gov (United States)

    National Aeronautics and Space Administration — his paper describes a local and distributed expectation maximization algorithm for learning parameters of Gaussian mixture models (GMM) in large peer-to-peer (P2P)...

  3. A Local Scalable Distributed Expectation Maximization Algorithm for Large Peer-to-Peer Networks

    Data.gov (United States)

    National Aeronautics and Space Administration — This paper describes a local and distributed expectation maximization algorithm for learning parameters of Gaussian mixture models (GMM) in large peer-to-peer (P2P)...

  4. Tendon’s ultrastructure

    Science.gov (United States)

    Tresoldi, Ilaria; Oliva, Francesco; Benvenuto, Monica; Fantini, Massimo; Masuelli, Laura; Bei, Roberto; Modesti, Andrea

    2013-01-01

    Summary The structure of a tendon is an important example of complexity of ECM three-dimensional organization. The extracellular matrix (ECM) is a macromolecular network with both structural and regulatory functions. ECM components belong to four major types of macromolecules: the collagens, elastin, proteoglycans, and noncollagenous glycoproteins. Tendons are made by a fibrous, compact connective tissue that connect muscle to bone designed to transmit forces and withstand tension during muscle contraction. Here we show the ultrastructural features of tendon’s components. PMID:23885339

  5. Distributed Evaluation of Local Sensitivity Analysis (DELSA), with application to hydrological models

    NARCIS (Netherlands)

    Rakovec, O.; Hill, M.C.; Clark, M.P.; Weerts, A.H.; Teuling, A.J.; Uijlenhoet, R.

    2014-01-01

    1] This paper presents a hybrid local-global sensitivity analysis method termed the Distributed Evaluation of Local Sensitivity Analysis (DELSA), which is used here to identify important and unimportant parameters and evaluate how model parameter importance changes as parameter values change. DELSA

  6. Cooperative and Distributed Localization for Wireless Sensor Networks in Multipath Environments

    CERN Document Server

    Leng, Mei; Quek, Tony Q S

    2011-01-01

    We consider the problem of sensor localization in a wireless network in a multipath environment, where time and angle of arrival information are available at each sensor. We propose a distributed algorithm based on belief propagation, which allows sensors to cooperatively self-localize with respect to one single anchor in a multihop network. The algorithm has low overhead and is scalable. Simulations show that although the network is loopy, the proposed algorithm converges, and achieves good localization accuracy.

  7. Regional Distribution Shifts Help Explain Local Changes in Wintering Raptor Abundance: Implications for Interpreting Population Trends

    Science.gov (United States)

    Paprocki, Neil; Heath, Julie A.; Novak, Stephen J.

    2014-01-01

    Studies of multiple taxa across broad-scales suggest that species distributions are shifting poleward in response to global climate change. Recognizing the influence of distribution shifts on population indices will be an important part of interpreting trends within management units because current practice often assumes that changes in local populations reflect local habitat conditions. However, the individual- and population-level processes that drive distribution shifts may occur across a large, regional scale and have little to do with the habitats within the management unit. We examined the latitudinal center of abundance for the winter distributions of six western North America raptor species using Christmas Bird Counts from 1975–2011. Also, we considered whether population indices within western North America Bird Conservation Regions (BCRs) were explained by distribution shifts. All six raptors had significant poleward shifts in their wintering distributions over time. Rough-legged Hawks (Buteo lagopus) and Golden Eagles (Aquila chrysaetos) showed the fastest rate of change, with 8.41 km yr−1 and 7.74 km yr−1 shifts, respectively. Raptors may be particularly responsive to warming winters because of variable migration tendencies, intraspecific competition for nesting sites that drives males to winter farther north, or both. Overall, 40% of BCR population trend models were improved by incorporating information about wintering distributions; however, support for the effect of distribution on BCR indices varied by species with Rough-legged Hawks showing the most evidence. These results emphasize the importance of understanding how regional distribution shifts influence local-scale population indices. If global climate change is altering distribution patterns, then trends within some management units may not reflect changes in local habitat conditions. The methods used to monitor and manage bird populations within local BCRs will fundamentally change as

  8. Regional distribution shifts help explain local changes in wintering raptor abundance: implications for interpreting population trends.

    Directory of Open Access Journals (Sweden)

    Neil Paprocki

    Full Text Available Studies of multiple taxa across broad-scales suggest that species distributions are shifting poleward in response to global climate change. Recognizing the influence of distribution shifts on population indices will be an important part of interpreting trends within management units because current practice often assumes that changes in local populations reflect local habitat conditions. However, the individual- and population-level processes that drive distribution shifts may occur across a large, regional scale and have little to do with the habitats within the management unit. We examined the latitudinal center of abundance for the winter distributions of six western North America raptor species using Christmas Bird Counts from 1975-2011. Also, we considered whether population indices within western North America Bird Conservation Regions (BCRs were explained by distribution shifts. All six raptors had significant poleward shifts in their wintering distributions over time. Rough-legged Hawks (Buteo lagopus and Golden Eagles (Aquila chrysaetos showed the fastest rate of change, with 8.41 km yr(-1 and 7.74 km yr(-1 shifts, respectively. Raptors may be particularly responsive to warming winters because of variable migration tendencies, intraspecific competition for nesting sites that drives males to winter farther north, or both. Overall, 40% of BCR population trend models were improved by incorporating information about wintering distributions; however, support for the effect of distribution on BCR indices varied by species with Rough-legged Hawks showing the most evidence. These results emphasize the importance of understanding how regional distribution shifts influence local-scale population indices. If global climate change is altering distribution patterns, then trends within some management units may not reflect changes in local habitat conditions. The methods used to monitor and manage bird populations within local BCRs will fundamentally

  9. Regional distribution shifts help explain local changes in wintering raptor abundance: implications for interpreting population trends.

    Science.gov (United States)

    Paprocki, Neil; Heath, Julie A; Novak, Stephen J

    2014-01-01

    Studies of multiple taxa across broad-scales suggest that species distributions are shifting poleward in response to global climate change. Recognizing the influence of distribution shifts on population indices will be an important part of interpreting trends within management units because current practice often assumes that changes in local populations reflect local habitat conditions. However, the individual- and population-level processes that drive distribution shifts may occur across a large, regional scale and have little to do with the habitats within the management unit. We examined the latitudinal center of abundance for the winter distributions of six western North America raptor species using Christmas Bird Counts from 1975-2011. Also, we considered whether population indices within western North America Bird Conservation Regions (BCRs) were explained by distribution shifts. All six raptors had significant poleward shifts in their wintering distributions over time. Rough-legged Hawks (Buteo lagopus) and Golden Eagles (Aquila chrysaetos) showed the fastest rate of change, with 8.41 km yr(-1) and 7.74 km yr(-1) shifts, respectively. Raptors may be particularly responsive to warming winters because of variable migration tendencies, intraspecific competition for nesting sites that drives males to winter farther north, or both. Overall, 40% of BCR population trend models were improved by incorporating information about wintering distributions; however, support for the effect of distribution on BCR indices varied by species with Rough-legged Hawks showing the most evidence. These results emphasize the importance of understanding how regional distribution shifts influence local-scale population indices. If global climate change is altering distribution patterns, then trends within some management units may not reflect changes in local habitat conditions. The methods used to monitor and manage bird populations within local BCRs will fundamentally change as

  10. An Iterated Local Search Algorithm for Estimating the Parameters of the Gamma/Gompertz Distribution

    Directory of Open Access Journals (Sweden)

    Behrouz Afshar-Nadjafi

    2014-01-01

    Full Text Available Extensive research has been devoted to the estimation of the parameters of frequently used distributions. However, little attention has been paid to estimation of parameters of Gamma/Gompertz distribution, which is often encountered in customer lifetime and mortality risks distribution literature. This distribution has three parameters. In this paper, we proposed an algorithm for estimating the parameters of Gamma/Gompertz distribution based on maximum likelihood estimation method. Iterated local search (ILS is proposed to maximize likelihood function. Finally, the proposed approach is computationally tested using some numerical examples and results are analyzed.

  11. Immunohistochemical, in situ hybridization, and ultrastructural localization of SARS-associated coronavirus in lung of a fatal case of severe acute respiratory syndrome in Taiwan.

    Science.gov (United States)

    Shieh, Wun-Ju; Hsiao, Cheng-Hsiang; Paddock, Christopher D; Guarner, Jeannette; Goldsmith, Cynthia S; Tatti, Kathleen; Packard, Michelle; Mueller, Laurie; Wu, Mu-Zong; Rollin, Pierre; Su, Ih-Jen; Zaki, Sherif R

    2005-03-01

    This article describes the pathological studies of fatal severe acute respiratory syndrome (SARS) in a 73-year-old man during an outbreak of SARS in Taiwan, 2003. Eight days before onset of symptoms, he visited a municipal hospital that was later identified as the epicenter of a large outbreak of SARS. On admission to National Taiwan University Hospital in Taipei, the patient experienced chest tightness, progressive dyspnea, and low-grade fever. His condition rapidly deteriorated with increasing respiratory difficulty, and he died 7 days after admission. The most prominent histopathologic finding was diffuse alveolar damage of the lung. Immunohistochemical and in situ hybridization assays demonstrated evidence of SARS-associated coronavirus (SARS-CoV) infection in various respiratory epithelial cells, predominantly type II pneumocytes, and in alveolar macrophages in the lung. Electron microscopic examination also revealed coronavirus particles in the pneumocytes, and their identity was confirmed as SARS-CoV by immunogold labeling electron microscopy. This report is the first to describe the cellular localization of SARS-CoV in human lung tissue by using a combination of immunohistochemistry, double-stain immunohistochemistry, in situ hybridization, electron microscopy, and immunogold labeling electron microscopy. These techniques represent valuable laboratory diagnostic modalities and provide insights into the pathogenesis of this emerging infection.

  12. Novel active contour model based on multi-variate local Gaussian distribution for local segmentation of MR brain images

    Science.gov (United States)

    Zheng, Qiang; Li, Honglun; Fan, Baode; Wu, Shuanhu; Xu, Jindong

    2017-09-01

    Active contour model (ACM) has been one of the most widely utilized methods in magnetic resonance (MR) brain image segmentation because of its ability of capturing topology changes. However, most of the existing ACMs only consider single-slice information in MR brain image data, i.e., the information used in ACMs based segmentation method is extracted only from one slice of MR brain image, which cannot take full advantage of the adjacent slice images' information, and cannot satisfy the local segmentation of MR brain images. In this paper, a novel ACM is proposed to solve the problem discussed above, which is based on multi-variate local Gaussian distribution and combines the adjacent slice images' information in MR brain image data to satisfy segmentation. The segmentation is finally achieved through maximizing the likelihood estimation. Experiments demonstrate the advantages of the proposed ACM over the single-slice ACM in local segmentation of MR brain image series.

  13. Green's function formalism in semi-infinite composites: an investigation of local field distribution

    Science.gov (United States)

    Li, Chen; Gu, Ying; Dai, Bing; Gong, Qi-Huang

    2004-11-01

    In the resonant composites, the formerly developed Green's function formalism (GFF) can be used to compute the local field distribution near resonance. In this paper, we extend the GFF in the infinite network to the semi-infinite networks by the method of image. Using the formalism, we investigate the local field distribution near resonance for the impurity clusters with admittance epsilon0 embedded in one semi-infinite network with epsilon1. With varying the admittance epsilon2 of another semi-infinite network, we find that the local fields in the boundary experience great changes, especially at epsilon2 = -epsilon1. The existence of the boundary enhances the localization of the fields within and around the metallic clusters. Therefore, the intensity of local field is influenced by the arrangement of impurity metallic bonds and its distance from the boundary.

  14. Green's function formalism in semi-infinite composites:an investigation of local field distribution

    Institute of Scientific and Technical Information of China (English)

    Li Chen; Gu Ying; Dai Bing; Gong Qi-Huang

    2004-01-01

    In the resonant composites, the formerly developed Green's function formalism (GFF) can be used to compute the local field distribution near resonance. In this paper, we extend the GFF in the infinite network to the semi-infinite networks by the method of image. Using the formalism, we investigate the local field distribution near resonance for the impurity clusters with admittance ∈0 embedded in one semi-infinite network with ∈1. With varying the admittance ∈2 of another semi-infinite network, we find that the local fields in the boundary experience great changes, especially at ∈2= -∈1. The existence of the boundary enhances the localization of the fields within and around the metallic clusters.Therefore, the intensity of local field is influenced by the arrangement of impurity metallic bonds and its distance from the boundary.

  15. Localization of WSN using Distributed Particle Swarm Optimization algorithm with precise references

    Science.gov (United States)

    Janapati, Ravi Chander; Balaswamy, Ch.; Soundararajan, K.

    2016-08-01

    Localization is the key research area in Wireless Sensor Networks. Finding the exact position of the node is known as localization. Different algorithms have been proposed. Here we consider a cooperative localization algorithm with censoring schemes using Crammer Rao Bound (CRB). This censoring scheme can improve the positioning accuracy and reduces computation complexity, traffic and latency. Particle swarm optimization (PSO) is a population based search algorithm based on the swarm intelligence like social behavior of birds, bees or a school of fishes. To improve the algorithm efficiency and localization precision, this paper presents an objective function based on the normal distribution of ranging error and a method of obtaining the search space of particles. In this paper Distributed localization algorithm PSO with CRB is proposed. Proposed method shows better results in terms of position accuracy, latency and complexity.

  16. Distribution of acid phosphatases in the hypopharyngeal glands from workers, queens and males of a Brazilian stingless bee Scaptotrigona postica Latreille: an ultrastructural cytochemical study.

    Science.gov (United States)

    Costa, R A; da Cruz-Landim, C

    2001-01-01

    The present study reports the localization of acid phosphatase in the hypopharyngeal gland cells from workers (newly-emerged, nurse and forager), queens (newly-emerged and laying) and males (newly-emerged and mature for mating) of the Brazilian stingless bee, Scaptotrigona postica. The phosphatase activity varied in intensity and localization depending on the individual class, physiological age and the substrate used. In newly-emerged workers, the phosphatase-positive sites suggest the involvement of the enzyme with cellular differentiation that occurs in the presecretory phase, in nurse workers with protein synthesis and in forager workers with changes in cellular activity or glandular regression. In males mature for mating and laying queens, the positive sites are related to secretory activity, showing that the gland maintains some activity in spite of the regressive aspect. Of the substrates used, beta-glycerophosphate gave the least specific localization.

  17. Distribution of local density of states in superstatistical random matrix theory

    Energy Technology Data Exchange (ETDEWEB)

    Abul-Magd, A.Y. [Department of Mathematics, Faculty of Science, Zagazig University, Zagazig (Egypt)]. E-mail: a_y_abul_magd@hotmail.com

    2007-07-02

    We expose an interesting connection between the distribution of local spectral density of states arising in the theory of disordered systems and the notion of superstatistics introduced by Beck and Cohen and recently incorporated in random matrix theory. The latter represents the matrix-element joint probability density function as an average of the corresponding quantity in the standard random-matrix theory over a distribution of level densities. We show that this distribution is in reasonable agreement with the numerical calculation for a disordered wire, which suggests to use the results of theory of disordered conductors in estimating the parameter distribution of the superstatistical random-matrix ensemble.

  18. Surface micro-distributions of pigment and the relation between smearing and local mass distribution

    Energy Technology Data Exchange (ETDEWEB)

    Buelow, K. E-mail: karin.bulow@nuclear.lu.se; Kristiansson, P.; Larsson, T.; Malmberg, S.; Elfman, M.; Malmqvist, K.; Pallon, J.; Shariff, A

    2001-07-01

    In this work, the process of smearing and its time evolution have been investigated. When smearing occurs, the print is removed from the printed paper and colours other parts of the paper or the printing press and destroys the final product. To study the re-distribution of ink, cyan ink with Cu as a tracer in the coloured pigment has been used. Non-printed paper has been pressed against the paper, 1 and 5 s after the printing. The micro-distributions of ink on both printed and non-printed papers have then been studied using particle-induced X-ray emission (PIXE). Basis weight was measured with the off-axis scanning transmission ion microscopy (STIM) technique and this data was correlated with the data from the print. One conclusion is that the process of smearing is not dependent on the shape of the pigment distribution, i.e. copper, or the content of copper in a specific pixel. On the contrary, the smearing was found to be related to the structure of the paper and that it mainly occurs where the paper is thicker.

  19. Distributed parameter estimation in wireless sensor networks using fused local observations

    Science.gov (United States)

    Fanaei, Mohammad; Valenti, Matthew C.; Schmid, Natalia A.; Alkhweldi, Marwan M.

    2012-05-01

    The goal of this paper is to reliably estimate a vector of unknown deterministic parameters associated with an underlying function at a fusion center of a wireless sensor network based on its noisy samples made at distributed local sensors. A set of noisy samples of a deterministic function characterized by a nite set of unknown param- eters to be estimated is observed by distributed sensors. The parameters to be estimated can be some attributes associated with the underlying function, such as its height, its center, its variances in dierent directions, or even the weights of its specic components over a predened basis set. Each local sensor processes its observation and sends its processed sample to a fusion center through parallel impaired communication channels. Two local processing schemes, namely analog and digital, are considered. In the analog local processing scheme, each sensor transmits an amplied version of its local analog noisy observation to the fusion center, acting like a relay in a wireless network. In the digital local processing scheme, each sensor quantizes its noisy observation before trans- mitting it to the fusion center. A at-fading channel model is considered between the local sensors and fusion center. The fusion center combines all of the received locally-processed observations and estimates the vector of unknown parameters of the underlying function. Two dierent well-known estimation techniques, namely maximum-likelihood (ML), for both analog and digital local processing schemes, and expectation maximization (EM), for digital local processing scheme, are considered at the fusion center. The performance of the proposed distributed parameter estimation system is investigated through simulation of practical scenarios for a sample underlying function.

  20. Distributed Channel Selection in CRAHNs with Heterogeneous Spectrum Opportunities: A Local Congestion Game Approach

    Science.gov (United States)

    Xu, Yuhua; Wu, Qihui; Wang, Jinlong; Min, Neng; Anpalagan, Alagan

    This letter investigates the problem of distributed channel selection in cognitive radio ad hoc networks (CRAHNs) with heterogeneous spectrum opportunities. Firstly, we formulate this problem as a local congestion game, which is proved to be an exact potential game. Then, we propose a spatial best response dynamic (SBRD) to rapidly achieve Nash equilibrium via local information exchange. Moreover, the potential function of the game reflects the network collision level and can be used to achieve higher throughput.

  1. Fundamental limitations of the local approximation for electron distribution function and fluid model in bounded plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Krasilnikov, M. B., E-mail: mihail.krasilnikov@gmail.com; Kudryavtsev, A. A. [St. Petersburg State University, St. Petersburg 198504 (Russian Federation); Kapustin, K. D. [St. Petersburg University ITMO, St. Petersburg 197101 (Russian Federation)

    2014-12-15

    It is shown that the local approximation for computing the electron distribution function depends both on the ratio between the energy relaxation length and a characteristic plasma length and on the ratio between heating and ambipolar electric fields. In particular, the local approximation is not valid at the discharge periphery even at high pressure due to the fact that the ambipolar electric field practically always is larger than the heating electric field.

  2. Local field distribution and configuration of CO molecules adsorbed on the nanostructure platinum surface

    Institute of Scientific and Technical Information of China (English)

    Huang Xiao-Jing; He Su-Zhen; Wu Chen-Xu

    2006-01-01

    This paper shows that the local electric field distribution near the nanostructure metallic surface is obtained by solving the Laplace equation, and furthermore, the configuration of CO molecules adsorbed on a Pt nanoparticle surface is obtained by using Monte Carlo simulation. It is found that the uneven local electric field distribution induced by the nanostructure surface can influence the configuration of carbon monoxide (CO) molecules by a force, which drags the adsorbates to the poles of the nanoparticles. This result, together with our results obtained before, may explain the experimental results that the nanostructure metallic surface can lead to abnormal phenomena such as anti-absorption infrared effects.

  3. Local strain distributions in partially recrystallized copper determined by in situ tensile investigation

    DEFF Research Database (Denmark)

    Lin, Fengxiang; Ubhi, H.S.; Zhang, Yubin

    2015-01-01

    A partially recrystallized copper sample produced by cold-rolling and annealing was deformed in situ by uniaxial tension in a scanning electron microscope, and electron backscatter diffraction data were collected before and after deformation to certain strains. The local strain distributions...... are quantified using digital image correlation. Distributions of the normal strain along the tensile direction (εxx) are shown in this paper. The recrystallized grains are found to deform more than the remaining unrecrystallized matrix. When εxx is averaged along lines perpendicular to the tensile direction......, significant variation are observed, which may be related to the local recrystallized volume fraction....

  4. Quasi-Local Energy Distribution and Thermodynamics of Reissner-Nordstrom Black Hole Surrounded by Quintessence

    Institute of Scientific and Technical Information of China (English)

    Mahamat Saleh; Bouetou Bouetou Thomas; Timoleon Crepin Kofane

    2011-01-01

    We investigate quasi-local energy distribution and thermodynamics of the Reissner-Nordstrom black hole space-time surrounded by quintessence.We use the quasi-local energy distribution from Einstein energy-momentum complex.We plot the variation of the energies, temperature and heat capacity with the state parameter related to the quintessence ωq.We show that due to the presence of quintessence, the total energy of the outer region as well as the temperature and heat capacity decreases with the increase of the density of quintessence, while the total energy of the black hole region increases.

  5. Efficient calculation of local dose distribution for response modelling in proton and ion beams

    CERN Document Server

    Greilich, S; Kiderlen, M; Andersen, C E; Bassler, N

    2013-01-01

    We present an algorithm for fast and accurate computation of the local dose distribution in MeV beams of protons, carbon ions or other heavy-charged particles. It uses compound Poisson-process modelling of track interaction and succesive convolutions for fast computation. It can handle mixed particle fields over a wide range of fluences. Since the local dose distribution is the essential part of several approaches to model detector efficiency or cellular response it has potential use in ion-beam dosimetry and radiotherapy.

  6. Efficient calculation of local dose distributions for response modeling in proton and heavier ion beams

    DEFF Research Database (Denmark)

    Greilich, Steffen; Hahn, Ute; Kiderlen, Markus;

    2014-01-01

    We present an algorithm for fast and accurate computation of the local dose distribution in MeV beams of protons, carbon ions or other heavy charged particles. It uses compound Poisson modeling of track interaction and successive convolutions for fast computation. It can handle arbitrary complex ...... mixed particle fields over a wide range of fluences. Since the local dose distribution is the essential part of several approaches to model detector efficiency and cellular response it has potential use in ion-beam dosimetry, radiotherapy, and radiobiology....

  7. Predictive Distribution of the Dirichlet Mixture Model by the Local Variational Inference Method

    DEFF Research Database (Denmark)

    Ma, Zhanyu; Leijon, Arne; Tan, Zheng-Hua;

    2014-01-01

    In Bayesian analysis of a statistical model, the predictive distribution is obtained by marginalizing over the parameters with their posterior distributions. Compared to the frequently used point estimate plug-in method, the predictive distribution leads to a more reliable result in calculating...... the predictive likelihood of the new upcoming data, especially when the amount of training data is small. The Bayesian estimation of a Dirichlet mixture model (DMM) is, in general, not analytically tractable. In our previous work, we have proposed a global variational inference-based method for approximately...... calculating the posterior distributions of the parameters in the DMM analytically. In this paper, we extend our previous study for the DMM and propose an algorithm to calculate the predictive distribution of the DMM with the local variational inference (LVI) method. The true predictive distribution of the DMM...

  8. Multiobjective Memetic Estimation of Distribution Algorithm Based on an Incremental Tournament Local Searcher

    Directory of Open Access Journals (Sweden)

    Kaifeng Yang

    2014-01-01

    Full Text Available A novel hybrid multiobjective algorithm is presented in this paper, which combines a new multiobjective estimation of distribution algorithm, an efficient local searcher and ε-dominance. Besides, two multiobjective problems with variable linkages strictly based on manifold distribution are proposed. The Pareto set to the continuous multiobjective optimization problems, in the decision space, is a piecewise low-dimensional continuous manifold. The regularity by the manifold features just build probability distribution model by globally statistical information from the population, yet, the efficiency of promising individuals is not well exploited, which is not beneficial to search and optimization process. Hereby, an incremental tournament local searcher is designed to exploit local information efficiently and accelerate convergence to the true Pareto-optimal front. Besides, since ε-dominance is a strategy that can make multiobjective algorithm gain well distributed solutions and has low computational complexity, ε-dominance and the incremental tournament local searcher are combined here. The novel memetic multiobjective estimation of distribution algorithm, MMEDA, was proposed accordingly. The algorithm is validated by experiment on twenty-two test problems with and without variable linkages of diverse complexities. Compared with three state-of-the-art multiobjective optimization algorithms, our algorithm achieves comparable results in terms of convergence and diversity metrics.

  9. Fire Source Localization Based on Distributed Temperature Sensing by a Dual-Line Optical Fiber System.

    Science.gov (United States)

    Sun, Miao; Tang, Yuquan; Yang, Shuang; Li, Jun; Sigrist, Markus W; Dong, Fengzhong

    2016-06-06

    We propose a method for localizing a fire source using an optical fiber distributed temperature sensor system. A section of two parallel optical fibers employed as the sensing element is installed near the ceiling of a closed room in which the fire source is located. By measuring the temperature of hot air flows, the problem of three-dimensional fire source localization is transformed to two dimensions. The method of the source location is verified with experiments using burning alcohol as fire source, and it is demonstrated that the method represents a robust and reliable technique for localizing a fire source also for long sensing ranges.

  10. Diagnosis by ultrastructural study of primary ciliary dyskinesia

    Directory of Open Access Journals (Sweden)

    Melgarejo-Moreno P

    2015-01-01

    Full Text Available Introduction and objective: Primary ciliary dyskinesia (PCD, also known as ciliary immotility (SIC syndrome is an inherited disorder that includes a group of diseases in which respiratory cilia are immobile, ciliary movement is dyskinetic and ineffective or no cilia . The aim of this study is to determine the ciliary ultrastructure in patients with suspected DCP. Method: In 8 patients with suspected DCP nasal mucosa biopsy is performed with endoscopy at the inferior turbinate in the middle third by the ENT service under local anesthesia. Results: Of the 8 cases studied in 2 cases no ciliary ultrastructural level defects were found. In two cases with abnormal ciliary ultrastructure is present Kartagener syndrome. In a case no cilia were observed in the nasal mucosa. Discussion: The DCP and SIC are synonymous terms from clinical and pathogenetic view: immobility and dyskinesia lead to an absence of mucociliary transport, stasis of respiratory secretions with their consequences: chronic infections of lower respiratory tract and from birth . The most common ultrastructural defect is the total or partial absence of dynein. Conclusions: The ultrastructural study allows the diagnosis of PCD because genetic diagnosis is complicated and therefore get an early diagnosis of this condition which serves to improve the morbidity and mortality of these patients.

  11. Distribution of immunoglobulin allotypes among local populations of Kenya olive baboons.

    Science.gov (United States)

    Oliver, T J; Coppenhaver, D H; Steinberg, A G

    1986-05-01

    In this paper we report on the distributions of immunoglobulin allotypes among 564 olive baboons collected at six localities in Kenya. The sample localities and sizes are 1) Lake Magadi, N = 107; 2) Nanyuki, N = 77; 3) Lake Baringo, N = 55; 4) Mosiro, N = 132; 5) Isiolo, N = 36; 6) Gilgil, N = 157. Gm allotypes 1, 10, 13, 15, and 17 are polymorphic among these samples. Gm(11) and Km(3) were present in all samples, and Gm(2,3,5,6,14,16,21,24,26) and Km(1) were absent from all samples. The proportions of individuals positive for polymorphic allotypes varied substantially between different local samples, as did the arrays and estimated frequencies of haplotypes. Allotype frequencies in local samples do not appear to be simply related to either geographic location or habitat characteristics of the localities. Our data suggest that much of the geographic variability in Kenya olive baboon populations occurs between populations separated by small geographic distances.

  12. Local host specialization, host-switching, and dispersal shape the regional distributions of avian haemosporidian parasites.

    Science.gov (United States)

    Ellis, Vincenzo A; Collins, Michael D; Medeiros, Matthew C I; Sari, Eloisa H R; Coffey, Elyse D; Dickerson, Rebecca C; Lugarini, Camile; Stratford, Jeffrey A; Henry, Donata R; Merrill, Loren; Matthews, Alix E; Hanson, Alison A; Roberts, Jackson R; Joyce, Michael; Kunkel, Melanie R; Ricklefs, Robert E

    2015-09-08

    The drivers of regional parasite distributions are poorly understood, especially in comparison with those of free-living species. For vector-transmitted parasites, in particular, distributions might be influenced by host-switching and by parasite dispersal with primary hosts and vectors. We surveyed haemosporidian blood parasites (Plasmodium and Haemoproteus) of small land birds in eastern North America to characterize a regional parasite community. Distributions of parasite populations generally reflected distributions of their hosts across the region. However, when the interdependence between hosts and parasites was controlled statistically, local host assemblages were related to regional climatic gradients, but parasite assemblages were not. Moreover, because parasite assemblage similarity does not decrease with distance when controlling for host assemblages and climate, parasites evidently disperse readily within the distributions of their hosts. The degree of specialization on hosts varied in some parasite lineages over short periods and small geographic distances independently of the diversity of available hosts and potentially competing parasite lineages. Nonrandom spatial turnover was apparent in parasite lineages infecting one host species that was well-sampled within a single year across its range, plausibly reflecting localized adaptations of hosts and parasites. Overall, populations of avian hosts generally determine the geographic distributions of haemosporidian parasites. However, parasites are not dispersal-limited within their host distributions, and they may switch hosts readily.

  13. Localizing Near and Far Field Acoustic Sources with Distributed Microhone Arrays

    DEFF Research Database (Denmark)

    Hansen, Martin Weiss; Jensen, Jesper Rindom; Christensen, Mads Græsbøll

    2014-01-01

    In this paper, we consider the problem of acoustic source localization using distributed microphone arrays. Time differences of arrival (TDOAs) are estimated using a recently proposed method based on joint direction of arrival (DOA) and range estimation. The TDOAs are used to estimate the locatio...

  14. How dispersal limitation shapes species-body size distributions in local communities

    NARCIS (Netherlands)

    Etienne, R.S.; Olff, H.

    2004-01-01

    A critical but poorly understood pattern in macroecology is the often unimodal species - body size distribution ( also known as body size - diversity relationship) in a local community ( embedded in a much larger regional species pool). Purely neutral community models that assume functional

  15. Efficient calculation of local dose distributions for response modeling in proton and heavier ion beams

    DEFF Research Database (Denmark)

    Greilich, Steffen; Hahn, Ute; Kiderlen, Markus

    2014-01-01

    We present an algorithm for fast and accurate computation of the local dose distribution in MeV beams of protons, carbon ions or other heavy charged particles. It uses compound Poisson modeling of track interaction and successive convolutions for fast computation. It can handle arbitrary complex ...

  16. Schools, Choice and Reputation: Local School Markets and the Distribution of Symbolic Capital in Segregated Cities

    Science.gov (United States)

    Bunar, Nihad; Ambrose, Anna

    2016-01-01

    An exploration is presented of how urban spaces, polarized by class and ethnicity, structure the basic conditions of emerging local school markets. The authors investigate how the distribution of symbolic capital, or "hot knowledge" of the market, affects schools, the market, and the urban spaces themselves. The study is guided by…

  17. A non-Gaussian distribution quantifies distances measured with fluorescence localization techniques

    DEFF Research Database (Denmark)

    Churchman, L.S.; Flyvbjerg, H.; Spudich, J.A.

    2006-01-01

    When single-molecule fluorescence localization techniques are pushed to their lower limits in attempts to measure ever-shorter distances, measurement errors become important to understand. Here we describe the non-Gaussian distribution of measured distances that is the key to proper interpretation...

  18. Distributed model predictive control for constrained nonlinear systems with decoupled local dynamics.

    Science.gov (United States)

    Zhao, Meng; Ding, Baocang

    2015-03-01

    This paper considers the distributed model predictive control (MPC) of nonlinear large-scale systems with dynamically decoupled subsystems. According to the coupled state in the overall cost function of centralized MPC, the neighbors are confirmed and fixed for each subsystem, and the overall objective function is disassembled into each local optimization. In order to guarantee the closed-loop stability of distributed MPC algorithm, the overall compatibility constraint for centralized MPC algorithm is decomposed into each local controller. The communication between each subsystem and its neighbors is relatively low, only the current states before optimization and the optimized input variables after optimization are being transferred. For each local controller, the quasi-infinite horizon MPC algorithm is adopted, and the global closed-loop system is proven to be exponentially stable.

  19. Scalable and Fully Distributed Localization in Large-Scale Sensor Networks

    Directory of Open Access Journals (Sweden)

    Miao Jin

    2017-06-01

    Full Text Available This work proposes a novel connectivity-based localization algorithm, well suitable for large-scale sensor networks with complex shapes and a non-uniform nodal distribution. In contrast to current state-of-the-art connectivity-based localization methods, the proposed algorithm is highly scalable with linear computation and communication costs with respect to the size of the network; and fully distributed where each node only needs the information of its neighbors without cumbersome partitioning and merging process. The algorithm is theoretically guaranteed and numerically stable. Moreover, the algorithm can be readily extended to the localization of networks with a one-hop transmission range distance measurement, and the propagation of the measurement error at one sensor node is limited within a small area of the network around the node. Extensive simulations and comparison with other methods under various representative network settings are carried out, showing the superior performance of the proposed algorithm.

  20. Mobile Codes Localization in Ad hoc Networks: a Comparative Study of Centralized and Distributed Approaches

    CERN Document Server

    Zafoune, Youcef; kanawati, Rushed; 10.5121/ijcnc.2010.2213

    2010-01-01

    This paper presents a new approach in the management of mobile ad hoc networks. Our alternative, based on mobile agent technology, allows the design of mobile centralized server in ad hoc network, where it is not obvious to think about a centralized management, due to the absence of any administration or fixed infrastructure in these networks. The aim of this centralized approach is to provide permanent availability of services in ad hoc networks which are characterized by a distributed management. In order to evaluate the performance of the proposed approach, we apply it to solve the problem of mobile code localization in ad hoc networks. A comparative study, based upon a simulation, of centralized and distributed localization protocols in terms of messages number exchanged and response time shows that the centralized approach in a distributed form is more interesting than a totally centralized approach.

  1. Local Field Distribution Function and High Order Field Moments for metal-dielectric composites.

    Science.gov (United States)

    Genov, Dentcho A.; Sarychev, Andrey K.; Shalaev, Vladimir M.

    2001-11-01

    In a span of two decades the physics of nonlinear optics saw vast improvement in our understanding of optical properties for various inhomogeneous mediums. One such medium is the metal-dielectric composite, where the metal inclusions have a surface coverage fraction of p, while the rest (1-p) is assumed to represent the dielectric host. The computations carried out by using different theoretical models and the experimental data show existence of giant local electric and magnetic field fluctuations. In this presentation we will introduce a new developed 2D model that determines exactly the Local Field Distribution Function (LFDF) and all other relevant parameters of the film. The LFDF for small filling factors will be shown to transform from lognormal distribution into a single-dipole distribution function. We also will confirm the predictions of the scaling theory for the high field moments, which have a power law dependence on the loss factor.

  2. On the Vertical Distribution of Local and Remote Sources of Water for Precipitation

    Science.gov (United States)

    Bosilovich, Michael G.

    2001-01-01

    The vertical distribution of local and remote sources of water for precipitation and total column water over the United States are evaluated in a general circulation model simulation. The Goddard Earth Observing System (GEOS) general circulation model (GCM) includes passive constituent tracers to determine the geographical sources of the water in the column. Results show that the local percentage of precipitable water and local percentage of precipitation can be very different. The transport of water vapor from remote oceanic sources at mid and upper levels is important to the total water in the column over the central United States, while the access of locally evaporated water in convective precipitation processes is important to the local precipitation ratio. This result resembles the conceptual formulation of the convective parameterization. However, the formulations of simple models of precipitation recycling include the assumption that the ratio of the local water in the column is equal to the ratio of the local precipitation. The present results demonstrate the uncertainty in that assumption, as locally evaporated water is more concentrated near the surface.

  3. On Distributed Localization for Road Sensor Networks: A Game Theoretic Approach

    Directory of Open Access Journals (Sweden)

    Jie Jia

    2013-01-01

    Full Text Available Road sensor network is an important part of vehicle networks system and is critical for many intelligent automobile scenarios, such as vehicle safety monitoring and transportation efficiency supporting. Localization of sensors is an active and crucial issue to most applications of road sensor network. Generally, given some anchor nodes’ positions and certain pairwise distance measurements, estimating the positions of all nonanchor nodes embodies a nonconvex optimization problem. However, due to the small number of anchor nodes and low sensor node connectivity degree in road sensor networks, the existing localization solutions are ineffective. In order to tackle this problem, a novel distributed localization method based on game theory for road sensor networks is proposed in this paper. Formally, we demonstrate that our proposed localization game is a potential game. Furthermore, we present several techniques to accelerate the convergence to the optimal solution. Simulation results demonstrate the effectiveness of our proposed algorithm.

  4. Improved Integrity Constraints Checking in Distributed Databases by Exploiting Local Checking

    Institute of Scientific and Technical Information of China (English)

    Ali A.Alwan; Hamidah Ibrahim; Nur Izura Udzir

    2009-01-01

    Most of the previous studies concerning checking the integrity constraints in distributed database derive simplified forms of the initial integrity constraints with the sufficiency property, since the sufficient test is known to be cheaper than the complete test and its initial integrity constraint as it involves less data to be transferred across the network and can always be evaluated at the target site (single site). Their studies are limited as they depend strictly on the assumption that an update operation will be executed at a site where the relation specified in the update operation is located, which is not always true. Hence, the sufficient test, which is proven to be local test by previous study, is no longer appropriate. This paper proposes an approach to checking integrity constraints in a distributed database by utilizing as much as possible the local information stored at the target site. The proposed approach derives support tests as an alternative to the existing complete and sufficient tests proposed by previous researchers with the intention to increase the number of local checking regardless the location of the submitted update operation. Several analyses have been performed to evaluate the proposed approach, and the results show that support tests can benefit the distributed database, where local constraint checking can be achieved.

  5. Predicting Posttraumatic Stress Symptom Prevalence and Local Distribution after an Earthquake with Scarce Data.

    Science.gov (United States)

    Dussaillant, Francisca; Apablaza, Mauricio

    2017-08-01

    After a major earthquake, the assignment of scarce mental health emergency personnel to different geographic areas is crucial to the effective management of the crisis. The scarce information that is available in the aftermath of a disaster may be valuable in helping predict where are the populations that are in most need. The objectives of this study were to derive algorithms to predict posttraumatic stress (PTS) symptom prevalence and local distribution after an earthquake and to test whether there are algorithms that require few input data and are still reasonably predictive. A rich database of PTS symptoms, informed after Chile's 2010 earthquake and tsunami, was used. Several model specifications for the mean and centiles of the distribution of PTS symptoms, together with posttraumatic stress disorder (PTSD) prevalence, were estimated via linear and quantile regressions. The models varied in the set of covariates included. Adjusted R2 for the most liberal specifications (in terms of numbers of covariates included) ranged from 0.62 to 0.74, depending on the outcome. When only including peak ground acceleration (PGA), poverty rate, and household damage in linear and quadratic form, predictive capacity was still good (adjusted R2 from 0.59 to 0.67 were obtained). Information about local poverty, household damage, and PGA can be used as an aid to predict PTS symptom prevalence and local distribution after an earthquake. This can be of help to improve the assignment of mental health personnel to the affected localities. Dussaillant F , Apablaza M . Predicting posttraumatic stress symptom prevalence and local distribution after an earthquake with scarce data. Prehosp Disaster Med. 2017;32(4):357-367.

  6. Nanoparticles as Alternative Strategies for Drug Delivery to the Alzheimer Brain: Electron Microscopy Ultrastructural Analysis.

    Science.gov (United States)

    Aliev, Gjumrakch; Daza, Jesús; Herrera, Arturo Solís; del Carmen Arias Esparza, María; Morales, Ludis; Echeverria, Valentina; Bachurin, Sergey Olegovich; Barreto, George Emilio

    2015-01-01

    One of the biggest problems and challenges for the development of new drugs and treatment strategies against Alzheimer Disease (AD) is the crossing of target drugs into the blood brain barrier. The use of nanoparticles in drug delivery therapy holds much promise in targeting remote tissues, and as a result many studies have attempted to study the ultrastructural localization of nanoparticles in various tissues. However, there are currently no in vivo studies demonstrating the ultrastructural distribution of nanoparticles in the brain. The aim of this study was to address how intraperitoneal injection of silver nanoparticles in the brain leads to leaking on the inter-endothelial contact and luminal plasma membrane, thus elucidating the possibility of penetrating into the most affected areas in the Alzheimer brain (vascular endothelium, perivascular, neuronal and glial cells). Our results show that the silver nanoparticles reached the brain and were found in hippocampal areas, indicating that they can be conjugated and used to deliver the drugs into the cell cytoplasm of the damaged brain cells. The present study can be useful for the development of novel drug delivering therapy and useful in understanding the delivery, distribution and effects of silver nanoparticles in AD brain tissue at cellular and subcellular level.

  7. The Distribution of Coalescing Compact Binaries in the Local Universe: Prospects for Gravitational-Wave Observations

    CERN Document Server

    Kelley, Luke Zoltan; Zemp, Marcel; Diemand, Jürg; Mandel, Ilya

    2010-01-01

    Merging compact binaries are the most viable and best studied candidates for gravitational wave (GW) detection by the fully operational network of ground-based observatories. In anticipation of the first detections, the expected distribution of GW sources in the local universe is of considerable interest. Here we investigate the full phase space distribution of coalescing compact binaries at $z = 0$ using dark matter simulations of structure formation. The fact that these binary systems acquire large barycentric velocities at birth (``kicks") results in merger site distributions that are more diffusely distributed with respect to their putative hosts, with mergers occurring out to distances of a few Mpc from the host halo. Redshift estimates based solely on the nearest galaxy in projection can, as a result, be inaccurate. On the other hand, large offsets from the host galaxy could aid the detection of faint optical counterparts and should be considered when designing strategies for follow-up observations. The...

  8. Distributed embedded controller development with petri nets application to globally-asynchronous locally-synchronous systems

    CERN Document Server

    Moutinho, Filipe de Carvalho

    2016-01-01

    This book describes a model-based development approach for globally-asynchronous locally-synchronous distributed embedded controllers.  This approach uses Petri nets as modeling formalism to create platform and network independent models supporting the use of design automation tools.  To support this development approach, the Petri nets class in use is extended with time-domains and asynchronous-channels. The authors’ approach uses models not only providing a better understanding of the distributed controller and improving the communication among the stakeholders, but also to be ready to support the entire lifecycle, including the simulation, the verification (using model-checking tools), the implementation (relying on automatic code generators), and the deployment of the distributed controller into specific platforms. Uses a graphical and intuitive modeling formalism supported by design automation tools; Enables verification, ensuring that the distributed controller was correctly specified; Provides flex...

  9. STM investigations of local potential barrier distribution of the atomic surface of graphite

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    To modulate the tunneling gap with the lock-in amplifier in the scanning tunneling microscopy(STM), information of the tunneling current variation can be obtained. The local potential barrier distribution of graphite surface atoms is got by means of such technology. Compared with STM image under topography observation mode, the local potential barrier image has higher resolu tion and less influence on the tip and better anti-interference capability. Obs erved results of the graphite are given and discussed in this paper.

  10. Feature Extraction Method for High Impedance Ground Fault Localization in Radial Power Distribution Networks

    DEFF Research Database (Denmark)

    Jensen, Kåre Jean; Munk, Steen M.; Sørensen, John Aasted

    1998-01-01

    processes and communication systems lead to demands for improved monitoring of power distribution networks so that the quality of power delivery can be kept at a controlled level. The ground fault localization method for each feeder in a network is based on the centralized frequency broadband measurement...... of three phase voltages and currents. The method consists of a feature extractor, based on a grid description of the feeder by impulse responses, and a neural network for ground fault localization. The emphasis of this paper is the feature extractor, and the detection of the time instance of a ground fault...

  11. Distributed Classification of Localization Attacks in Sensor Networks Using Exchange-Based Feature Extraction and Classifier

    Directory of Open Access Journals (Sweden)

    Su-Zhe Wang

    2016-01-01

    Full Text Available Secure localization under different forms of attack has become an essential task in wireless sensor networks. Despite the significant research efforts in detecting the malicious nodes, the problem of localization attack type recognition has not yet been well addressed. Motivated by this concern, we propose a novel exchange-based attack classification algorithm. This is achieved by a distributed expectation maximization extractor integrated with the PECPR-MKSVM classifier. First, the mixed distribution features based on the probabilistic modeling are extracted using a distributed expectation maximization algorithm. After feature extraction, by introducing the theory from support vector machine, an extensive contractive Peaceman-Rachford splitting method is derived to build the distributed classifier that diffuses the iteration calculation among neighbor sensors. To verify the efficiency of the distributed recognition scheme, four groups of experiments were carried out under various conditions. The average success rate of the proposed classification algorithm obtained in the presented experiments for external attacks is excellent and has achieved about 93.9% in some cases. These testing results demonstrate that the proposed algorithm can produce much greater recognition rate, and it can be also more robust and efficient even in the presence of excessive malicious scenario.

  12. Speciation and distribution of arsenic and localization of nutrients in rice grains

    Energy Technology Data Exchange (ETDEWEB)

    Lombi, E.; Scheckel, K.G.; Pallon, J.; Carey, A.M.; Zhu, Y.G.; Meharg, A.A. (EPA); (UCopenhagen); (Aberdeen); (Lund); (Chinese Aca. Sci.)

    2012-09-05

    Arsenic (As) contamination of rice grains and the generally low concentration of micronutrients in rice have been recognized as a major concern for human health. Here, we investigated the speciation and localization of As and the distribution of (micro)nutrients in rice grains because these are key factors controlling bioavailability of nutrients and contaminants. Bulk total and speciation analyses using high-pressure liquid chromatography (HPLC)-inductively coupled plasma mass spectrometry (ICP-MS) and X-ray absorption near-edge spectroscopy (XANES) was complemented by spatially resolved microspectroscopic techniques ({mu}-XANES, {mu}-X-ray fluorescence ({mu}-XRF) and particle induced X-ray emission (PIXE)) to investigate both speciation and distribution of As and localization of nutrients in situ. The distribution of As and micronutrients varied between the various parts of the grains (husk, bran and endosperm) and was characterized by element-specific distribution patterns. The speciation of As in bran and endosperm was dominated by As(III)-thiol complexes. The results indicate that the translocation from the maternal to filial tissues may be a bottleneck for As accumulation in the grain. Strong similarities between the distribution of iron (Fe), manganese (Mn) and phosphorus (P) and between zinc (Zn) and sulphur (S) may be indicative of complexation mechanisms in rice grains.

  13. Stabilization of Nonuniform Euler-Bernoulli Beam with Locally Distributed Feedbacks

    Institute of Scientific and Technical Information of China (English)

    Xian-bing CAO; Qing-xu YAN

    2012-01-01

    In this article,we study the stabilization problem of a nonuniform Euler-Bernoulli beam with locally distributed feedbacks.Firstly,using the semi-group theory,we establish the well-posedness of the associated closed loop system.Then by proving the uniqueness of the solution of a related ordinary differential equations,we derive the asymptotic stability of the closed loop system. Finally,by means of the piecewise frequency domain multiplier method,we prove that the corresponding closed loop system can be exponentially stabilized by only one of the two distributed feedback controls proposed in this paper.

  14. Structure in the 3D Galaxy Distribution: II. Voids and Watersheds of Local Maxima and Minima

    CERN Document Server

    Way, M J; Scargle, Jeffrey D

    2014-01-01

    The major uncertainties in studies of the multi-scale structure of the Universe arise not from observational errors but from the variety of legitimate definitions and detection methods for individual structures. To facilitate the study of these methodological dependencies we have carried out 12 different analyses defining structures in various ways. This has been done in a purely geometrical way by utilizing the HOP algorithm as a unique parameter-free method of assigning groups of galaxies to local density maxima or minima. From three density estimation techniques (smoothing kernels, Bayesian Blocks and self organizing maps) applied to three data sets (the Sloan Digital Sky Survey Data Release 7, the Millennium Simulation and randomly distributed points) we tabulate information that can be used to construct catalogs of structures connected to local density maxima and minima. The resulting sizes follow continuous multi-scale distributions with no indication of the presence of a discrete hierarchy. We also int...

  15. Luminescence with Local Distribution and Its Possible Mechanism in Zinc Oxide Micro-Crystallites

    Institute of Scientific and Technical Information of China (English)

    SHI Yuan-Yuan; TIAN Ke; LIN Bi-Xia; FU Zhu-Xi

    2007-01-01

    @@ The spatial luminescence distribution in the ZnO microocrystallite films deposited on silicon substrates by CVD at room temperature is investigated by the cathedoluminescence (CL) image. It has been observed that the CL image of the samples constitutes a certain pattern. The UV emission pattern projective to the (0001) face of ZnO grains consists of a series of lines nearby the grain boundaries .The included angles between any two adjacent lines are almost 120°. What is more, some luminescent lines form a close hexagon similar to ZnO crystalline structure. Such a local distribution property shows that the UV emission on as-grown ZnO crystallite should be due to some local defects congregated to {10(1)0} facets of ZnO grain rather than free exciton recombination.

  16. The local subsurface water and chlorine distributions evaluated by DAN/MSL in Curiosity observational campaigns

    Science.gov (United States)

    Litvak, Maxim; Mitrofanov, Igor; Hardgrove, Craig; Sanin, Anton; Lisov, Denis; Golovin, Dmitry; Jun, Insoo; Kozyrev, Alexander; Malakhov, Alexey; Mischna, Michael; Moersch, Jeffrey; Nikiforov, Sergey; Tate, Cristopher; Vostrukhin, Andrey

    2016-04-01

    The measurements with the Dynamic Albedo of Neutrons (DAN) instrument onboard the Mars Science Laboratory (MSL) Curiosity rover are presented and analyzed as a summary of observations acquired during several special observational campaigns at the Yellowknife Bay area (first discovery of habitability environment), at the striated units of Kimberley formation, at outcrops studied in Pahrump Hills (at the base of Mt Sharp) and in high silica area discovered in Marias Pass (Mudstone facies of the Murray formation). DAN data were analyzed to test local and global variability in the distribution of bulk hydrogen and neutron-absorbing elements, characterized as chlorine-equivalent concentration. Using multi instrument approach in the data analysis we have compared DAN estimations of subsurface H and Cl distributions with inhomogeneity of local geological context, top surface measurements of chlorine with APXS and with SAM measurements of absorbed H2O extracted from the drilled samples based on low temperature evolved gas analysis.

  17. Local active information storage as a tool to understand distributed neural information processing.

    Science.gov (United States)

    Wibral, Michael; Lizier, Joseph T; Vögler, Sebastian; Priesemann, Viola; Galuske, Ralf

    2014-01-01

    Every act of information processing can in principle be decomposed into the component operations of information storage, transfer, and modification. Yet, while this is easily done for today's digital computers, the application of these concepts to neural information processing was hampered by the lack of proper mathematical definitions of these operations on information. Recently, definitions were given for the dynamics of these information processing operations on a local scale in space and time in a distributed system, and the specific concept of local active information storage was successfully applied to the analysis and optimization of artificial neural systems. However, no attempt to measure the space-time dynamics of local active information storage in neural data has been made to date. Here we measure local active information storage on a local scale in time and space in voltage sensitive dye imaging data from area 18 of the cat. We show that storage reflects neural properties such as stimulus preferences and surprise upon unexpected stimulus change, and in area 18 reflects the abstract concept of an ongoing stimulus despite the locally random nature of this stimulus. We suggest that LAIS will be a useful quantity to test theories of cortical function, such as predictive coding.

  18. A method of analysis of distributions of local electric fields in composites

    Science.gov (United States)

    Kolesnikov, V. I.; Yakovlev, V. B.; Bardushkin, V. V.; Lavrov, I. V.; Sychev, A. P.; Yakovleva, E. N.

    2016-03-01

    A method of prediction of distributions of local electric fields in composite media based on analysis of the tensor operators of the concentration of intensity and induction is proposed. Both general expressions and the relations for calculating these operators are obtained in various approximations. The analytical expressions are presented for the operators of the concentration of electric fields in various types of inhomogeneous structures obtained in the generalized singular approximation.

  19. The two-stage aegean extension, from localized to distributed, a result of slab rollback acceleration

    OpenAIRE

    Brun, Jean-Pierre; Faccenna, Claudio; Gueydan, Frédéric; Sokoutis, Dimitrios; Philippon, Mélody; Kydonakis, Konstantinos; Gorini, Christian

    2016-01-01

    International audience; Back-arc extension in the Aegean, which was driven by slab rollback since 45 Ma, is described here for the first time in two stages. From Middle Eocene to Middle Miocene, deformation was localized leading to i) the exhumation of high-pressure metamorphic rocks to crustal depths, ii) the exhumation of high-temperature metamorphic rocks in core complexes and iii) the deposition of sedimentary basins. Since Middle Miocene, extension distributed over the whole Aegean domai...

  20. The impact of local stellar radiation on the HI column density distribution

    CERN Document Server

    Rahmati, Alireza; Pawlik, Andreas H; Raičević, Milan

    2013-01-01

    It is often assumed that local sources of ionizing radiation have little impact on the distribution of HI in the post-reionization Universe. While this is a good assumption for the IGM, analytic arguments suggest that local sources may typically be more important than the background radiation for high column density absorbers (N_HI > 10^17 /cm^2). We post-process cosmological simulations with accurate radiation transport to investigate the impact of local stellar sources on the HI distribution. We demonstrate that the limited numerical resolution and the simplified treatment of the ISM that are typical of current cosmological simulations provide significant challenges, but that many of the problems can be overcome by taking two steps. First, using ISM particles rather than stellar particles as sources results in a much better sampling of the source distribution. Second, by rescaling the source luminosities so that the amount of radiation escaping into the IGM agrees with that required to produce the observed ...

  1. Harmonic Differential Quadrature Analysis of Soft-Core Sandwich Panels under Locally Distributed Loads

    Directory of Open Access Journals (Sweden)

    Xinwei Wang

    2016-11-01

    Full Text Available Sandwich structures are widely used in practice and thus various engineering theories adopting simplifying assumptions are available. However, most engineering theories of beams, plates and shells cannot recover all stresses accurately through their constitutive equations. Therefore, the soft-core is directly modeled by two-dimensional (2D elasticity theory without any pre-assumption on the displacement field. The top and bottom faces act like the elastic supports on the top and bottom edges of the core. The differential equations of the 2D core are then solved by the harmonic differential quadrature method (HDQM. To circumvent the difficulties in dealing with the locally distributed load by point discrete methods such as the HDQM, a general and rigorous way is proposed to treat the locally distributed load. Detailed formulations are provided. The static behavior of sandwich panels under different locally distributed loads is investigated. For verification, results are compared with data obtained by ABAQUS with very fine meshes. A high degree of accuracy on both displacement and stress has been observed.

  2. Local Voltage Support from Distributed Energy Resources to Prevent Air Conditioner Motor Stalling

    Energy Technology Data Exchange (ETDEWEB)

    Baone, Chaitanya A [ORNL; Xu, Yan [ORNL; Kueck, John D [ORNL

    2010-01-01

    Microgrid voltage collapse often happens when there is a high percentage of low inertia air-conditioning (AC) motors in the power systems. The stalling of the AC motors results in Fault Induced Delayed Voltage Recovery (FIDVR). A hybrid load model including typical building loads, AC motor loads, and other induction motor loads is built to simulate the motoring stalling phenomena. Furthermore, distributed energy resources (DE) with local voltage support capability are utilized to boost the local bus voltage during a fault, and prevent the motor stalling. The simulation results are presented. The analysis of the simulation results show that local voltage support from multiple DEs can effectively and economically solve the microgrid voltage collapse problem.

  3. Sum-capacity of Interference Channels with a Local View: Impact of Distributed Decisions

    CERN Document Server

    Aggarwal, Vaneet; Sabharwal, Ashutosh

    2009-01-01

    Due to the large size of wireless networks, it is often impractical for nodes to track changes in the complete network state. As a result, nodes have to make distributed decisions about their transmission and reception parameters based on their local view of the network. In this paper, we characterize the impact of distributed decisions on the global network performance in terms of achievable sum-rates. We first formalize the concept of local view by proposing a protocol abstraction using the concept of local message passing. In the proposed protocol, nodes forward information about the network state to other neighboring nodes, thereby allowing network state information to trickle to all the nodes. The protocol proceeds in rounds, where all transmitters send a message followed by a message by all receivers. The number of rounds then provides a natural metric to quantify the extent of local information at each node. We next study three network connectivities, Z-channel, a three-user double Z-channel and a redu...

  4. A Self-Organizing Incremental Neural Network based on local distribution learning.

    Science.gov (United States)

    Xing, Youlu; Shi, Xiaofeng; Shen, Furao; Zhou, Ke; Zhao, Jinxi

    2016-12-01

    In this paper, we propose an unsupervised incremental learning neural network based on local distribution learning, which is called Local Distribution Self-Organizing Incremental Neural Network (LD-SOINN). The LD-SOINN combines the advantages of incremental learning and matrix learning. It can automatically discover suitable nodes to fit the learning data in an incremental way without a priori knowledge such as the structure of the network. The nodes of the network store rich local information regarding the learning data. The adaptive vigilance parameter guarantees that LD-SOINN is able to add new nodes for new knowledge automatically and the number of nodes will not grow unlimitedly. While the learning process continues, nodes that are close to each other and have similar principal components are merged to obtain a concise local representation, which we call a relaxation data representation. A denoising process based on density is designed to reduce the influence of noise. Experiments show that the LD-SOINN performs well on both artificial and real-word data. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Distribution, ultrastructural localization, and ontogeny of the core protein of a heparan sulfate proteoglycan in human skin and other basement membranes

    DEFF Research Database (Denmark)

    Horiguchi, Y; Couchman, J R; Ljubimov, A V;

    1989-01-01

    A variety of heparan sulfate proteoglycans (HSPG) have been identified on cell surfaces and in basement membrane (BM). To more fully characterize HSPG in human skin BM, we used two monoclonal antibodies (MAb) directed against epitopes of the core protein of a high molecular weight HSPG isolated...

  6. Ultrastructure of quiescent oocytes of Cebus albifrons.

    Science.gov (United States)

    Barton, B R; Hertig, A T

    1975-11-01

    Quiescent oocytes of the monkey Cebus albifrons were examined with the electron microscope. In many respects the ultrastructure of these cells was similar to that of other mammalian species. Elongate and oval mitochondria, lamellar Golgi complexes, small profiles of smooth endoplasmic reticulum, and vacuolar organelles were randomly distributed around a round nucleus which usually contained a nucleolus and clumps of heterochromatin. Among the unusual morphological characteristics of these oocytes are 'membranous aggregates', membrane-bound organelles containing a complex of convoluted membranes, some very dense rod-like structures and a droplet of moderate density which resembles lipid. A similar droplet is frequently found in mitochondria. Rough endoplasmic reticulum is abundant in many of these oocytes, forming parallel arrays and concentric rings around the nucleus. Folded membrane complexes, apparent elaborations of smooth endoplasmic reticulum, are frequently found in the cytoplasm in continuity with cisternae of smooth and rough endoplasmic reticulum and associated with vesicles which often contain flocculent material. The morphology of Cebus oocytes suggests a greater rate of steroid and protein synthesis, transport, and storage than is usually indicated by the ultrastructure of other mammalian oocytes.

  7. Analysis of the spatial-local distribution of the sport complexes using GIS system

    Directory of Open Access Journals (Sweden)

    Naeim Amiri

    2014-07-01

    Full Text Available This article studies theexiting status of the sport spaces of Kerman city using geographicalinformation system (GIS. After studying the exiting status of the sportspaces, it was found that the exiting distribution of sport spaces in the urbanhierarchical level is not appropriate. In carrying out this research, first thefield survey was performed using GPS, and then the resulted data were insertedin GIS software. After that, by applying the descriptive-analytical methodusing the resulted information, and also by applying the library method, thespatial- local distribution of the sport complexes of Kerman city was studied.The findings resulted indicate that distribution of the sport complexes centersof Kerman city, in contrast with other urban facilities, show lower abeyancefrom the urban categorical rules (urban zones, regions, areas andneighborhoods. In some regions, even sever shortage of sport complexes wasobserved. This article tries to provide some strategies for development ofsport complexes towards meeting the citizens' needs.

  8. An Estimation of Distribution Algorithm with Intelligent Local Search for Rule-based Nurse Rostering

    CERN Document Server

    Uwe, Aickelin; Jingpeng, Li

    2007-01-01

    This paper proposes a new memetic evolutionary algorithm to achieve explicit learning in rule-based nurse rostering, which involves applying a set of heuristic rules for each nurse's assignment. The main framework of the algorithm is an estimation of distribution algorithm, in which an ant-miner methodology improves the individual solutions produced in each generation. Unlike our previous work (where learning is implicit), the learning in the memetic estimation of distribution algorithm is explicit, i.e. we are able to identify building blocks directly. The overall approach learns by building a probabilistic model, i.e. an estimation of the probability distribution of individual nurse-rule pairs that are used to construct schedules. The local search processor (i.e. the ant-miner) reinforces nurse-rule pairs that receive higher rewards. A challenging real world nurse rostering problem is used as the test problem. Computational results show that the proposed approach outperforms most existing approaches. It is ...

  9. Comparative sperm ultrastructure in Nemertea.

    Science.gov (United States)

    von Döhren, J; Beckers, P; Vogeler, R; Bartolomaeus, T

    2010-07-01

    Although the monophyly of Nemertea is strongly supported by unique morphological characters and results of molecular phylogenetic studies, their ingroup relationships are largely unresolved. To contribute solving this problem we studied sperm ultrastructure of 12 nemertean species that belong to different subtaxa representing the commonly recognized major monophyletic groups. The study yielded a set of 26 characters with an unexpected variation among species of the same genus (Tubulanus and Procephalothrix species), whereas other species varied in metric values or only one character state (Ramphogordius). In some species, the sperm nucleus has grooves (Zygonemertes virescens, Amphiporus imparispinosus) that may be twisted and give a spiral shape to the sperm head (Paranemertes peregrina, Emplectonema gracile). To make the characters from sperm ultrastructure accessible for further phylogenetic analyses, they were coded in a character matrix. Published data for eight species turned out to be sufficiently detailed to be included. Comparative evaluation of available information on the sperm ultrastructure suggests that subtaxa of Heteronemertea and Hoplonemertea are supported as monophyletic by sperm morphology. However, the data do not provide information on the existing contradictions regarding the internal relationships of "Palaeonemertea." Nevertheless, our study provides evidence that sperm ultrastructure yields numerous potentially informative characters that will be included in upcoming phylogenetic analyses.

  10. Inferring local competition intensity from patch size distributions: a test using biological soil crusts

    Science.gov (United States)

    Bowker, Matthew A.; Maestre, Fernando T.

    2012-01-01

    Dryland vegetation is inherently patchy. This patchiness goes on to impact ecology, hydrology, and biogeochemistry. Recently, researchers have proposed that dryland vegetation patch sizes follow a power law which is due to local plant facilitation. It is unknown what patch size distribution prevails when competition predominates over facilitation, or if such a pattern could be used to detect competition. We investigated this question in an alternative vegetation type, mosses and lichens of biological soil crusts, which exhibit a smaller scale patch-interpatch configuration. This micro-vegetation is characterized by competition for space. We proposed that multiplicative effects of genetics, environment and competition should result in a log-normal patch size distribution. When testing the prevalence of log-normal versus power law patch size distributions, we found that the log-normal was the better distribution in 53% of cases and a reasonable fit in 83%. In contrast, the power law was better in 39% of cases, and in 8% of instances both distributions fit equally well. We further hypothesized that the log-normal distribution parameters would be predictably influenced by competition strength. There was qualitative agreement between one of the distribution's parameters (μ) and a novel intransitive (lacking a 'best' competitor) competition index, suggesting that as intransitivity increases, patch sizes decrease. The correlation of μ with other competition indicators based on spatial segregation of species (the C-score) depended on aridity. In less arid sites, μ was negatively correlated with the C-score (suggesting smaller patches under stronger competition), while positive correlations (suggesting larger patches under stronger competition) were observed at more arid sites. We propose that this is due to an increasing prevalence of competition transitivity as aridity increases. These findings broaden the emerging theory surrounding dryland patch size distributions

  11. Hierarchical models for failure analysis of plates bent by distributed and localized transverse loadings

    Institute of Scientific and Technical Information of China (English)

    Erasmo CARRERA; Gaetano GIUNTA

    2008-01-01

    The failure analysis of simply supported, isotropic, square plates is addressed. Attention focuses on minimum failure load amplitudes and failure locations, von Mises' equivalent stress along the plate thickness is also addressed. Several distributed and localized loading conditions are considered. Loads act on the top of the plate. Bi-sinusoidal and uniform loads are taken into account for distributed loadings, while stepwise constant centric and off-centric loadings are addressed in the case of localized loadings. Analysis is performed considering plates whose length-to-thickness ratio a/h can be as high as 100 (thin plates) and as low as 2 (very thick plates). Results are obtained via several 2D plate models. Classical theories (CTs) and higher order models are applied. Those theories are based on polynomial approximation of the displacement field. Among the higher order theories (HOTs), HOTsd models account for the transverse shear deformations, while HOTs models account for both transverse shear and transverse normal deformations. LHOTs represent a local application of the higher order theories. A layerwise approach is thus assumed: by means of mathematical interfaces, the plate is considered to be made of several fictitious layers. The exact 3D solution is presented in order to determine the accuracy of the results obtained via the 2D models. In this way a hierarchy among the 2D theories is established. CTs provide highly accurate results for a/h greater than 10 in the case of distributed loadings and greater than 20 for localized Ioadings. Results obtained via HOTs are highly accurate in the case of very thick plates for bi-sinusoidal and centric loadings. In the case of uniform and off-centric loadings a high gradient is present in the neighborhood of the plate top. In those cases, LHOTs yield results that match the exact solution.

  12. Spatio-temporal distribution of localized aerosol loading in China: A satellite view

    Science.gov (United States)

    Sun, Kun; Chen, Xiaoling

    2017-08-01

    In recent years, haze pollution and high concentrations of particulate matter frequently occur in many mega cities of China, which has seriously impacted the regional air quality, and further caused harm to human health. Although satellite observation provides a convenient way to evaluate air quality in space and time, satellite measurements do not separate between natural and anthropogenic aerosols. To discriminate anthropogenic aerosol contribution from satellite observations, we proposed the concept of Local Aerosol Optical Depth (LAOD) to describe the localized aerosol loading. A comparative analysis was performed between seasonal/monthly Mean AOD (MAOD), LAOD and ground measured PM2.5/PM10. The comparison results show that LAOD has better linear relationship with PM2.5/PM10 than MAOD in central and eastern China with persistent localized aerosol emissions. Based on the MODIS Deep Blue AOD dataset from 2001 to 2015, we analyzed the spatio-temporal distribution of LAOD over China. Spatially, high LAODs are mainly distributed in Sichuan basin, North China Plain, and central China; temporally, LAOD over China presents an upward trend (+0.003 year-1) during 2001-2007 and a weak downward (-0.002 year-1) trend from 2008 to 2015. LAOD was also found to be highly correlated with haze frequency over most areas of central and eastern China, especially in North China Plain with a correlation coefficient of 0.87 (P aerosol emission on regional haze pollution in China.

  13. Detection prospects for high energy neutrino sources from the anisotropic matter distribution in the local Universe

    Science.gov (United States)

    Mertsch, Philipp; Rameez, Mohamed; Tamborra, Irene

    2017-03-01

    Constraints on the number and luminosity of the sources of the cosmic neutrinos detected by IceCube have been set by targeted searches for point sources. We set complementary constraints by using the 2MASS Redshift Survey (2MRS) catalogue, which maps the matter distribution of the local Universe. Assuming that the distribution of the neutrino sources follows that of matter, we look for correlations between ``warm'' spots on the IceCube skymap and the 2MRS matter distribution. Through Monte Carlo simulations of the expected number of neutrino multiplets and careful modelling of the detector performance (including that of IceCube-Gen2), we demonstrate that sources with local density exceeding 10‑6 Mpc‑3 and neutrino luminosity Lν lesssim 1042 erg s‑1 (1041 erg s‑1) will be efficiently revealed by our method using IceCube (IceCube-Gen2). At low luminosities such as will be probed by IceCube-Gen2, the sensitivity of this analysis is superior to requiring statistically significant direct observation of a point source.

  14. Study of Climate Change Impact to Local Rainfall Distribution in Lampung Provinces

    Directory of Open Access Journals (Sweden)

    Tumiar Katarina Manik

    2016-08-01

    Full Text Available Global warming which leads to climate change has potential affect to Indonesia agriculture activities and production. Analyzing rainfall pattern and distribution is important to investigate the impact of global climate change to local climate. This study using rainfall data from 1976-2010 from both lowland and upland area of Lampung Province. The results show that rainfall tends to decrease since the 1990s which related to the years with El Nino event. Monsoonal pattern- having rain and dry season- still excist in Lampung; however, since most rain fell below the average, it could not meet crops water need. Farmers conclude that dry seasons were longer and seasonal pattern has been changed. Global climate change might affect Lampung rainfall distribution through changes on sea surface temperature which could intensify the El Nino effect. Therefore, watching the El Nino phenomena and how global warming affects it, is important in predicting local climate especially the rainfall distribution in order to prevent significant loss in agriculture productivities.

  15. A Local Scalable Distributed Expectation Maximization Algorithm for Large Peer-to-Peer Networks

    Science.gov (United States)

    Bhaduri, Kanishka; Srivastava, Ashok N.

    2009-01-01

    This paper offers a local distributed algorithm for expectation maximization in large peer-to-peer environments. The algorithm can be used for a variety of well-known data mining tasks in a distributed environment such as clustering, anomaly detection, target tracking to name a few. This technology is crucial for many emerging peer-to-peer applications for bioinformatics, astronomy, social networking, sensor networks and web mining. Centralizing all or some of the data for building global models is impractical in such peer-to-peer environments because of the large number of data sources, the asynchronous nature of the peer-to-peer networks, and dynamic nature of the data/network. The distributed algorithm we have developed in this paper is provably-correct i.e. it converges to the same result compared to a similar centralized algorithm and can automatically adapt to changes to the data and the network. We show that the communication overhead of the algorithm is very low due to its local nature. This monitoring algorithm is then used as a feedback loop to sample data from the network and rebuild the model when it is outdated. We present thorough experimental results to verify our theoretical claims.

  16. Observability and Estimation of Distributed Space Systems via Local Information-Exchange Networks

    Science.gov (United States)

    Rahmani, Amirreza; Mesbahi, Mehran; Fathpour, Nanaz; Hadaegh, Fred Y.

    2008-01-01

    In this work, we develop an approach to formation estimation by explicitly characterizing formation's system-theoretic attributes in terms of the underlying inter-spacecraft information-exchange network. In particular, we approach the formation observer/estimator design by relaxing the accessibility to the global state information by a centralized observer/estimator- and in turn- providing an analysis and synthesis framework for formation observers/estimators that rely on local measurements. The noveltyof our approach hinges upon the explicit examination of the underlying distributed spacecraft network in the realm of guidance, navigation, and control algorithmic analysis and design. The overarching goal of our general research program, some of whose results are reported in this paper, is the development of distributed spacecraft estimation algorithms that are scalable, modular, and robust to variations inthe topology and link characteristics of the formation information exchange network. In this work, we consider the observability of a spacecraft formation from a single observation node and utilize the agreement protocol as a mechanism for observing formation states from local measurements. Specifically, we show how the symmetry structure of the network, characterized in terms of its automorphism group, directly relates to the observability of the corresponding multi-agent system The ramification of this notion of observability over networks is then explored in the context of distributed formation estimation.

  17. Arsenic-induced bone marrow toxicity: ultrastructural and electron-probe analysis

    Energy Technology Data Exchange (ETDEWEB)

    Feussner, J.R.; Shelburne, J.D.; Bredehoeft, S.; Cohen, H.J.

    1979-05-01

    A patient with severe arsenic poisoning that resulted in marked peripheral blood and bone marrow abnormalities, including megaloblastic erythropoiesis experienced many of the previously reported hematologic complications of arsenic poisoning: leukopenia, granulocytopenia, absolute eosinophilia, and profound anemia. In this study we report an ultrastructural and electron-proble analysis of the bone marrow. Although megaloblastic anemia associated with arsenic poisoning has been described rarely, the presence of arsenic in the local bone marrow milieu has not been demonstrated previously. The ultrastructural features of arsenic-induced bone marrow toxicity are similar to those described in other dyserythropoietic states and include marked nuclear aberrations involving shape, chromatin distribution, and nuclear envelope. Using the technique of energy-dispersive x-ray analysis (electron probe) we demonstrated arsenic in bone marrow spicules; this supports the contention that arsenic can cause megaloblastic anemia. We suggest that this technique may be a useful tool in further studies that attempt to explore the mechanism of arsenic-induced hematologic toxicity. Finally, we suggest that arsenic has a direct toxic effect on DNA synthesis that results in marked disturbances of nuclear division. We recommend that the most appropriate screening procedure to evaluate possible arsenic poisoning is tissue arsenic measurements (hair and nails) rather than 24-hr urinary measurements.

  18. Addressing potential local adaptation in species distribution models: implications for conservation under climate change

    Science.gov (United States)

    Hällfors, Maria Helena; Liao, Jishan; Dzurisin, Jason D. K.; Grundel, Ralph; Hyvärinen, Marko; Towle, Kevin; Wu, Grace C.; Hellmann, Jessica J.

    2016-01-01

    Species distribution models (SDMs) have been criticized for involving assumptions that ignore or categorize many ecologically relevant factors such as dispersal ability and biotic interactions. Another potential source of model error is the assumption that species are ecologically uniform in their climatic tolerances across their range. Typically, SDMs to treat a species as a single entity, although populations of many species differ due to local adaptation or other genetic differentiation. Not taking local adaptation into account, may lead to incorrect range prediction and therefore misplaced conservation efforts. A constraint is that we often do not know the degree to which populations are locally adapted, however. Lacking experimental evidence, we still can evaluate niche differentiation within a species' range to promote better conservation decisions. We explore possible conservation implications of making type I or type II errors in this context. For each of two species, we construct three separate MaxEnt models, one considering the species as a single population and two of disjunct populations. PCA analyses and response curves indicate different climate characteristics in the current environments of the populations. Model projections into future climates indicate minimal overlap between areas predicted to be climatically suitable by the whole species versus population-based models. We present a workflow for addressing uncertainty surrounding local adaptation in SDM application and illustrate the value of conducting population-based models to compare with whole-species models. These comparisons might result in more cautious management actions when alternative range outcomes are considered.

  19. Addressing potential local adaptation in species distribution models: implications for conservation under climate change.

    Science.gov (United States)

    Hällfors, Maria Helena; Liao, Jishan; Dzurisin, Jason; Grundel, Ralph; Hyvärinen, Marko; Towle, Kevin; Wu, Grace C; Hellmann, Jessica J

    2016-06-01

    Species distribution models (SDMs) have been criticized for involving assumptions that ignore or categorize many ecologically relevant factors such as dispersal ability and biotic interactions. Another potential source of model error is the assumption that species are ecologically uniform in their climatic tolerances across their range. Typically, SDMs treat a species as a single entity, although populations of many species differ due to local adaptation or other genetic differentiation. Not taking local adaptation into account may lead to incorrect range prediction and therefore misplaced conservation efforts. A constraint is that we often do not know the degree to which populations are locally adapted. Lacking experimental evidence, we still can evaluate niche differentiation within a species' range to promote better conservation decisions. We explore possible conservation implications of making type I or type II errors in this context. For each of two species, we construct three separate Max-Ent models, one considering the species as a single population and two of disjunct populations. Principal component analyses and response curves indicate different climate characteristics in the current environments of the populations. Model projections into future climates indicate minimal overlap between areas predicted to be climatically suitable by the whole species vs. population-based models. We present a workflow for addressing uncertainty surrounding local adaptation in SDM application and illustrate the value of conducting population-based models to compare with whole-species models. These comparisons might result in more cautious management actions when alternative range outcomes are considered.

  20. Uncertainty in identifying local extinctions: the distribution of missing data and its effects on biodiversity measures.

    Science.gov (United States)

    Boakes, Elizabeth H; Fuller, Richard A; McGowan, Philip J K; Mace, Georgina M

    2016-03-01

    Identifying local extinctions is integral to estimating species richness and geographic range changes and informing extinction risk assessments. However, the species occurrence records underpinning these estimates are frequently compromised by a lack of recorded species absences making it impossible to distinguish between local extinction and lack of survey effort-for a rigorously compiled database of European and Asian Galliformes, approximately 40% of half-degree cells contain records from before but not after 1980. We investigate the distribution of these cells, finding differences between the Palaearctic (forests, low mean human influence index (HII), outside protected areas (PAs)) and Indo-Malaya (grassland, high mean HII, outside PAs). Such cells also occur more in less peaceful countries. We show that different interpretations of these cells can lead to large over/under-estimations of species richness and extent of occurrences, potentially misleading prioritization and extinction risk assessment schemes. To avoid mistakes, local extinctions inferred from sightings records need to account for the history of survey effort in a locality.

  1. Ubiquitous distribution and different subcellular localization of sorbitol dehydrogenase in fruit and leaf of apple.

    Science.gov (United States)

    Wang, Xiu-Ling; Xu, Yan-Hong; Peng, Chang-Cao; Fan, Ren-Chun; Gao, Xin-Qi

    2009-01-01

    NAD(+)-dependent sorbitol dehydrogenase (NAD-SDH, EC 1.1.1.14), a key enzyme in sorbitol metabolism, plays an important role in regulating sink strength and determining the quality of apple fruit. Understanding the tissue and subcellular localization of NAD-SDH is helpful for understanding sorbitol metabolism in the apple. In this study, two NAD-SDH cDNA sequences were isolated from apple fruits (Malus domestica Borkh cv. Starkrimson) and named MdSDH5 and MdSDH6. Immunohistochemical analysis revealed that NAD-SDH is distributed in both the flesh and the vascular tissue of the fruit, and the vascular tissue and mesophyll tissue in the young and old leaves, indicating that it is a ubiquitous protein expressed in both sink and source organs. Immunogold electron microscopy analysis demonstrated that NAD-SDH is localized mainly in the cytoplasm and chloroplast of the fruit and leaves. The chloroplast localization of NAD-SDH was confirmed by the transient expression of MdSDH5-GFP and MdSDH6-GFP in the mesophyll protoplast of Arabidopsis. NAD-SDH was also found in electron opaque deposits of vacuoles in young and mature leaves. These data show that NAD-SDH has different subcellular localizations in fruit and leaves, indicating that it might play a different role in sorbitol metabolism in different tissues of apple.

  2. A scalable, locality aware, fault-tolerant, and decentralized location scheme for distributed networks

    Institute of Scientific and Technical Information of China (English)

    BAI Hai-huan; JIANG Jun-jie; ZOU Fu-tai; WANG Wei-nong

    2005-01-01

    This paper presents Isotope, an efficient, locality aware, fault-tolerant, and decentralized scheme for data location in distributed networks. This scheme is designed based on the mathematical model of decentralized location services and thus has provable correctness and performance. In Isotope, each node needs to only maintain linkage information with about O( log n) other nodes and any node can be reached within O( log n) routing hops. Compared with other related schemes, Isotope' s average locating path length is only half that of Chord,and its locating performance and locality-awareness are sinilar to that of Pastry and Tapestry. In addition, Isotope is more suitable for constantly changing networks because it needs to exchange only O(log n) O(log n)messages to update the routing information for nodes arrival, departure and failure.

  3. Local Voltage Control in Distribution Networks: A Game-Theoretic Perspective

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Xinyang; Tian, Jie; Chen, Lijun; Dall' Anese, Emiliano

    2016-11-21

    Inverter-based voltage regulation is gaining importance to alleviate emerging reliability and power-quality concerns related to distribution systems with high penetration of photovoltaic (PV) systems. This paper seeks contribution in the domain of reactive power compensation by establishing stability of local Volt/VAr controllers. In lieu of the approximate linear surrogate used in the existing work, the paper establishes existence and uniqueness of an equilibrium point using nonlinear AC power flow model. Key to this end is to consider a nonlinear dynamical system with non-incremental local Volt/VAr control, cast the Volt/VAr dynamics as a game, and leverage the fixed-point theorem as well as pertinent contraction mapping argument. Numerical examples are provided to complement the analytical results.

  4. Local Voltage Control in Distribution Networks: A Game-Theoretic Perspective: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Xinyang; Tian, Jie; Chen, Lijun; Dall' Anese, Emiliano

    2016-09-01

    Inverter-based voltage regulation is gaining importance to alleviate emerging reliability and power-quality concerns related to distribution systems with high penetration of photovoltaic (PV) systems. This paper seeks contribution in the domain of reactive power compensation by establishing stability of local Volt/VAr controllers. In lieu of the approximate linear surrogate used in the existing work, the paper establishes existence and uniqueness of an equilibrium point using nonlinear AC power flow model. Key to this end is to consider a nonlinear dynamical system with non-incremental local Volt/VAr control, cast the Volt/VAr dynamics as a game, and leverage the fixed-point theorem as well as pertinent contraction mapping argument. Numerical examples are provided to complement the analytical results.

  5. Secure Quantum Key Distribution Network with Bell States and Local Unitary Operations

    Institute of Scientific and Technical Information of China (English)

    LI Chun-Yan; ZHOU Hong-Yu; WANG Yan; DENG Fu-Guo

    2005-01-01

    @@ We propose a theoretical scheme for secure quantum key distribution network following the ideas in quantum dense coding. In this scheme, the server of the network provides the service for preparing and measuring the Bell states,and the users encode the states with local unitary operations. For preventing the server from eavesdropping, we design a decoy when the particle is transmitted between the users. The scheme has high capacity as one particle carries two bits of information and its efficiency for qubits approaches 100%. Moreover, it is unnecessary for the users to store the quantum states, which makes this scheme more convenient in applications than others.

  6. Multiple concurrent sources localization based on a two-node distributed acoustic sensor network

    Science.gov (United States)

    Xu, Jiaxin; Zhao, Zhao; Chen, Chunzeng; Xu, Zhiyong

    2017-01-01

    In this work, we propose a new approach to localize multiple concurrent sources using a distributed acoustic sensor network. Only two node-arrays are required in this sensor network, and each node-array consists of only two widely spaced sensors. Firstly, direction-of-arrivals (DOAs) of multiple sources are estimated at each node-array by utilizing a new pooled angular spectrum proposed in this paper, which can implement the spatial aliasing suppression effectively. Based on minimum variance distortionless response (MVDR) beamforming and the DOA estimates of the sources, the time-frequency spectra containing the corresponding energy distribution features associated with those sources are reconstructed in each node-array. Then, scale invariant feature transform (SIFT) is employed to solve the DOA association problem. Performance evaluation is conducted with field recordings and experimental results prove the effectivity and feasibility of the proposed method.

  7. Macroscopic locality with equal bias reproduces with high fidelity a quantum distribution achieving the Tsirelson's bound

    Science.gov (United States)

    Gazi, Md. Rajjak; Banik, Manik; Das, Subhadipa; Rai, Ashutosh; Kunkri, Samir

    2013-11-01

    Two physical principles, macroscopic locality (ML) and information causality (IC), so far have been most successful in distinguishing quantum correlations from post-quantum correlations. However, there are also some post-quantum probability distributions which cannot be distinguished with the help of these principles. Thus, it is interesting to see whether consideration of these two principles, separately, along with some additional physically plausible constraints, can explain some interesting quantum features which are otherwise hard to reproduce. In this paper we show that in a Bell-Clauser-Horne-Shimony-Holt scenario, ML along with the constraint of equal bias for the concerned observables, almost reproduces the quantum joint probability distribution corresponding to a maximal quantum Bell violation, which is unique up to relabeling. From this example and earlier work of Cavalcanti, Salles, and Scarani, we conclude that IC and ML are inequivalent physical principles; satisfying one does not imply that the other is satisfied.

  8. Imaging of local temperature distributions in mesas of high-Tc superconducting terahertz sources

    Science.gov (United States)

    Tsujimoto, M.; Kambara, H.; Maeda, Y.; Yoshioka, Y.; Nakagawa, Y.; Kakeya, I.

    2014-12-01

    Stacks of intrinsic Josephson junctions in high-Tc superconductors are a promising source of intense, continuous, and monochromatic terahertz waves. In this paer, we establish a fluorescence-based temperature imaging system to directly image the surface temperature on a Bi2Sr2CaCu2O8+δ mesa sample. Intense terahertz emissions are observed in both high- and low-bias regimes, where the mesa voltage satisfies the cavity resonance condition. In the high- bias regime, the temperature distributions are shown to be inhomogeneous with a considerable temperature rise. In contrast, in the low-bias regime, the distributions are rather uniform and the local temperature is close to the bath temperature over the entire sample.

  9. Quantifying how the full local distribution of daily precipitation is changing and its uncertainties

    Science.gov (United States)

    Stainforth, David; Chapman, Sandra; Watkins, Nicholas

    2016-04-01

    The study of the consequences of global warming would benefit from quantification of geographical patterns of change at specific thresholds or quantiles, and better understandings of the intrinsic uncertainties in such quantities. For precipitation a range of indices have been developed which focus on high percentiles (e.g. rainfall falling on days above the 99th percentile) and on absolute extremes (e.g. maximum annual one day precipitation) but scientific assessments are best undertaken in the context of changes in the whole climatic distribution. Furthermore, the relevant thresholds for climate-vulnerable policy decisions, adaptation planning and impact assessments, vary according to the specific sector and location of interest. We present a methodology which maintains the flexibility to provide information at different thresholds for different downstream users, both scientists and decision makers. We develop a method[1,2] for analysing local climatic timeseries to assess which quantiles of the local climatic distribution show the greatest and most robust changes in daily precipitation data. We extract from the data quantities that characterize the changes in time of the likelihood of daily precipitation above a threshold and of the amount of precipitation on those days. Our method is a simple mathematical deconstruction of how the difference between two observations from two different time periods can be assigned to the combination of natural statistical variability and/or the consequences of secular climate change. This deconstruction facilitates an assessment of how fast different quantiles of precipitation distributions are changing. This involves not only determining which quantiles and geographical locations show the greatest and smallest changes, but also those at which uncertainty undermines the ability to make confident statements about any change there may be. We demonstrate this approach using E-OBS gridded data[3] which are timeseries of local daily

  10. Global-to-Local Approach to Rigorously Developing Distributed System with Exception Handling

    Institute of Scientific and Technical Information of China (English)

    Chao Cai; Zong-Yan Qiu; Hong-Li Yang; Xiang-Peng Zhao

    2009-01-01

    Cooperative distributed system covers a wide range of applications such as the systems for industrial controlling and business-to-business trading, which are usually safety-critical. Coordinated exception handling (CEH) refers to exception handling in the cooperative distributed systems, where exceptions raised on a peer should be dealt with by all relevant peers in a consistent manner. Some CEH algorithms have been proposed. A crucial problem in using these algorithms is how to develop the peers which are guaranteed coherent in both normal execution and exceptional execution. Straightforward testing or model checking is very expensive. In this paper, we propose an effective way to rigorously develop the systems with correct CEH behavior. Firstly, we formalize the CEH algorithm by proposing a Peer Process Language to precisely describe the distributed systems and their operational semantics. Then we dig out a set of syntactic conditions, and prove its sufficiency for system coherence. Finally, we propose a global-to-local approach, including a language describing the distributed systems from a global perspective and a projection algorithm, for developing the systems. Given a well-formed global description, a set of peers can be generated automatically. We prove the system composed of these peers satisfies the conditions, that is, it is always coherent and correct for CEH.

  11. Regional data refine local predictions: modeling the distribution of plant species abundance on a portion of the central plains.

    Science.gov (United States)

    Young, Nicholas E; Stohlgren, Thomas J; Evangelista, Paul H; Kumar, Sunil; Graham, Jim; Newman, Greg

    2012-09-01

    Species distribution models are frequently used to predict species occurrences in novel conditions, yet few studies have examined the consequences of extrapolating locally collected data to regional landscapes. Similarly, the process of using regional data to inform local prediction for species distribution models has not been adequately evaluated. Using boosted regression trees, we examined errors associated with extrapolating models developed with locally collected abundance data to regional-scale spatial extents and associated with using regional data for predictions at a local extent for a native and non-native plant species across the northeastern central plains of Colorado. Our objectives were to compare model results and accuracy between those developed locally and extrapolated regionally, those developed regionally and extrapolated locally, and to evaluate extending species distribution modeling from predicting the probability of presence to predicting abundance. We developed models to predict the spatial distribution of plant species abundance using topographic, remotely sensed, land cover and soil taxonomic predictor variables. We compared model predicted mean and range abundance values to observed values between local and regional. We also evaluated model prediction performance based on Pearson's correlation coefficient. We show that: (1) extrapolating local models to regional extents may restrict predictions, (2) regional data can help refine and improve local predictions, and (3) boosted regression trees can be useful to model and predict plant species abundance. Regional sampling designed in concert with large sampling frameworks such as the National Ecological Observatory Network may improve our ability to monitor changes in local species abundance.

  12. Reptilian spermatogenesis: A histological and ultrastructural perspective

    OpenAIRE

    Gribbins, Kevin M

    2011-01-01

    Until recently, the histology and ultrastructural events of spermatogenesis in reptiles were relatively unknown. Most of the available morphological information focuses on specific stages of spermatogenesis, spermiogenesis, and/or of the mature spermatozoa. No study to date has provided complete ultrastructural information on the early events of spermatogenesis, proliferation and meiosis in class Reptilia. Furthermore, no comprehensive data set exists that describes the ultrastructure of the ...

  13. Local storage federation through XRootD architecture for interactive distributed analysis

    Science.gov (United States)

    Colamaria, F.; Colella, D.; Donvito, G.; Elia, D.; Franco, A.; Luparello, G.; Maggi, G.; Miniello, G.; Vallero, S.; Vino, G.

    2015-12-01

    A cloud-based Virtual Analysis Facility (VAF) for the ALICE experiment at the LHC has been deployed in Bari. Similar facilities are currently running in other Italian sites with the aim to create a federation of interoperating farms able to provide their computing resources for interactive distributed analysis. The use of cloud technology, along with elastic provisioning of computing resources as an alternative to the grid for running data intensive analyses, is the main challenge of these facilities. One of the crucial aspects of the user-driven analysis execution is the data access. A local storage facility has the disadvantage that the stored data can be accessed only locally, i.e. from within the single VAF. To overcome such a limitation a federated infrastructure, which provides full access to all the data belonging to the federation independently from the site where they are stored, has been set up. The federation architecture exploits both cloud computing and XRootD technologies, in order to provide a dynamic, easy-to-use and well performing solution for data handling. It should allow the users to store the files and efficiently retrieve the data, since it implements a dynamic distributed cache among many datacenters in Italy connected to one another through the high-bandwidth national network. Details on the preliminary architecture implementation and performance studies are discussed.

  14. Local and distributed PiB accumulation associated with development of preclinical Alzheimer’s disease

    Science.gov (United States)

    Brier, Matthew R.; McCarthy, John E.; Benzinger, Tammie L.S.; Stern, Ari; Su, Yi; Friedrichsen, Karl A.; Morris, John C.; Ances, Beau M.; Vlassenko, Andrei G.

    2017-01-01

    Amyloid-beta plaques are a hallmark of Alzheimer’s disease (AD) that can be assessed by amyloid imaging (e.g., Pittsburgh B compound [PiB]) and summarized as a scalar value. Summary values may have clinical utility but are an average over many regions of interest, potentially obscuring important topography. This study investigates the longitudinal evolution of amyloid topographies in cognitively normal older adults who had normal (N = 131) or abnormal (N = 26) PiB scans at baseline. At 3 years follow-up, 16 participants with a previously normal PiB scan had conversion to PiB scans consistent with preclinical AD. We investigated the multivariate relationship (canonical correlation) between baseline and follow-up PiB topographies. Furthermore, we used penalized regression to investigate the added information derived from PiB topography compared to summary measures. PiB accumulation can be local, that is, a topography predicting the same topography in the future, and/or distributed, that is, one topography predicting another. Both local and distributed PiB accumulation was associated with conversion of PiB status. Additionally, elements of the multivariate topography, and not the commonly used summary scalar, correlated with future PiB changes. Consideration of the entire multivariate PiB topography provides additional information regarding the development of amyloid-beta pathology in very early preclinical AD. PMID:26827648

  15. Local and distributed PiB accumulation associated with development of preclinical Alzheimer's disease.

    Science.gov (United States)

    Brier, Matthew R; McCarthy, John E; Benzinger, Tammie L S; Stern, Ari; Su, Yi; Friedrichsen, Karl A; Morris, John C; Ances, Beau M; Vlassenko, Andrei G

    2016-02-01

    Amyloid-beta plaques are a hallmark of Alzheimer's disease (AD) that can be assessed by amyloid imaging (e.g., Pittsburgh B compound [PiB]) and summarized as a scalar value. Summary values may have clinical utility but are an average over many regions of interest, potentially obscuring important topography. This study investigates the longitudinal evolution of amyloid topographies in cognitively normal older adults who had normal (N = 131) or abnormal (N = 26) PiB scans at baseline. At 3 years follow-up, 16 participants with a previously normal PiB scan had conversion to PiB scans consistent with preclinical AD. We investigated the multivariate relationship (canonical correlation) between baseline and follow-up PiB topographies. Furthermore, we used penalized regression to investigate the added information derived from PiB topography compared to summary measures. PiB accumulation can be local, that is, a topography predicting the same topography in the future, and/or distributed, that is, one topography predicting another. Both local and distributed PiB accumulation was associated with conversion of PiB status. Additionally, elements of the multivariate topography, and not the commonly used summary scalar, correlated with future PiB changes. Consideration of the entire multivariate PiB topography provides additional information regarding the development of amyloid-beta pathology in very early preclinical AD.

  16. The Structure, Density, and Local Environment Distribution in Ab Initio Liquid Water

    Science.gov (United States)

    Santra, Biswajit; Distasio, Robert A., Jr.; Wu, Xifan; Car, Roberto

    2014-03-01

    We have performed extensive ab initio molecular dynamics (AIMD) simulations of liquid water at ambient conditions in the canonical (NVT) and isothermal-isobaric (NPT) ensembles to understand the individual and collective importance of exact exchange, van der Waals interactions, and nuclear quantum effects on the structural properties of liquid water. AIMD simulations which include these effects result in oxygen-oxygen radial distribution functions which are in excellent agreement with experiments and a liquid water structure having an equilibrium density within 1% of the experimental value of 1 g/cm3. A detailed analysis of the distribution of local structure in ambient liquid water has revealed that the inherent potential energy surface is bimodal with respect to high- and low-density molecular environments, consistent with the existence of polymorphism in the amorphous phases of water. With these findings in mind, the methodology presented herein overcomes the well-known limitations of semi-local density functional theory (GGA-DFT) providing a detailed and accurate microscopic description of ambient liquid water. DOE: DE-SC0008626, DOE: DE-SC0005180, NSF: CHE-0956500.

  17. Observability and Estimation of Distributed Space Systems via Local Information-Exchange Networks

    Science.gov (United States)

    Fathpour, Nanaz; Hadaegh, Fred Y.; Mesbahi, Mehran; Rahmani, Amirreza

    2011-01-01

    Spacecraft formation flying involves the coordination of states among multiple spacecraft through relative sensing, inter-spacecraft communication, and control. Most existing formation-flying estimation algorithms can only be supported via highly centralized, all-to-all, static relative sensing. New algorithms are proposed that are scalable, modular, and robust to variations in the topology and link characteristics of the formation exchange network. These distributed algorithms rely on a local information exchange network, relaxing the assumptions on existing algorithms. Distributed space systems rely on a signal transmission network among multiple spacecraft for their operation. Control and coordination among multiple spacecraft in a formation is facilitated via a network of relative sensing and interspacecraft communications. Guidance, navigation, and control rely on the sensing network. This network becomes more complex the more spacecraft are added, or as mission requirements become more complex. The observability of a formation state was observed by a set of local observations from a particular node in the formation. Formation observability can be parameterized in terms of the matrices appearing in the formation dynamics and observation matrices. An agreement protocol was used as a mechanism for observing formation states from local measurements. An agreement protocol is essentially an unforced dynamic system whose trajectory is governed by the interconnection geometry and initial condition of each node, with a goal of reaching a common value of interest. The observability of the interconnected system depends on the geometry of the network, as well as the position of the observer relative to the topology. For the first time, critical GN&C (guidance, navigation, and control estimation) subsystems are synthesized by bringing the contribution of the spacecraft information-exchange network to the forefront of algorithmic analysis and design. The result is a

  18. Distributed Evaluation of Local Sensitivity Analysis (DELSA), with application to hydrologic models

    Science.gov (United States)

    Rakovec, O.; Hill, M. C.; Clark, M. P.; Weerts, A. H.; Teuling, A. J.; Uijlenhoet, R.

    2014-01-01

    This paper presents a hybrid local-global sensitivity analysis method termed the Distributed Evaluation of Local Sensitivity Analysis (DELSA), which is used here to identify important and unimportant parameters and evaluate how model parameter importance changes as parameter values change. DELSA uses derivative-based "local" methods to obtain the distribution of parameter sensitivity across the parameter space, which promotes consideration of sensitivity analysis results in the context of simulated dynamics. This work presents DELSA, discusses how it relates to existing methods, and uses two hydrologic test cases to compare its performance with the popular global, variance-based Sobol' method. The first test case is a simple nonlinear reservoir model with two parameters. The second test case involves five alternative "bucket-style" hydrologic models with up to 14 parameters applied to a medium-sized catchment (200 km2) in the Belgian Ardennes. Results show that in both examples, Sobol' and DELSA identify similar important and unimportant parameters, with DELSA enabling more detailed insight at much lower computational cost. For example, in the real-world problem the time delay in runoff is the most important parameter in all models, but DELSA shows that for about 20% of parameter sets it is not important at all and alternative mechanisms and parameters dominate. Moreover, the time delay was identified as important in regions producing poor model fits, whereas other parameters were identified as more important in regions of the parameter space producing better model fits. The ability to understand how parameter importance varies through parameter space is critical to inform decisions about, for example, additional data collection and model development. The ability to perform such analyses with modest computational requirements provides exciting opportunities to evaluate complicated models as well as many alternative models.

  19. Predicting habitat suitability for rare plants at local spatial scales using a species distribution model.

    Science.gov (United States)

    Gogol-Prokurat, Melanie

    2011-01-01

    If species distribution models (SDMs) can rank habitat suitability at a local scale, they may be a valuable conservation planning tool for rare, patchily distributed species. This study assessed the ability of Maxent, an SDM reported to be appropriate for modeling rare species, to rank habitat suitability at a local scale for four edaphic endemic rare plants of gabbroic soils in El Dorado County, California, and examined the effects of grain size, spatial extent, and fine-grain environmental predictors on local-scale model accuracy. Models were developed using species occurrence data mapped on public lands and were evaluated using an independent data set of presence and absence locations on surrounding lands, mimicking a typical conservation-planning scenario that prioritizes potential habitat on unsurveyed lands surrounding known occurrences. Maxent produced models that were successful at discriminating between suitable and unsuitable habitat at the local scale for all four species, and predicted habitat suitability values were proportional to likelihood of occurrence or population abundance for three of four species. Unfortunately, models with the best discrimination (i.e., AUC) were not always the most useful for ranking habitat suitability. The use of independent test data showed metrics that were valuable for evaluating which variables and model choices (e.g., grain, extent) to use in guiding habitat prioritization for conservation of these species. A goodness-of-fit test was used to determine whether habitat suitability values ranked habitat suitability on a continuous scale. If they did not, a minimum acceptable error predicted area criterion was used to determine the threshold for classifying habitat as suitable or unsuitable. I found a trade-off between model extent and the use of fine-grain environmental variables: goodness of fit was improved at larger extents, and fine-grain environmental variables improved local-scale accuracy, but fine-grain variables

  20. Acoustic Source Localization via Distributed Sensor Networks using Tera-scale Optical-Core Devices

    Energy Technology Data Exchange (ETDEWEB)

    Imam, Neena [ORNL; Barhen, Jacob [ORNL; Wardlaw, Michael [Office of Naval Research

    2008-01-01

    For real-time acoustic source localization applications, one of the primary challenges is the considerable growth in computational complexity associated with the emergence of ever larger, active or passive, distributed sensor networks. The complexity of the calculations needed to achieve accurate source localization increases dramatically with the size of sensor arrays, resulting in substantial growth of computational requirements that cannot be met with standard hardware. One option to meet this challenge builds upon the emergence of digital optical-core devices. The objective of this work was to explore the implementation of key building block algorithms used in underwater source localization on an optical-core digital processing platform recently introduced by Lenslet Inc. They investigate key concepts of threat-detection algorithms such as Time Difference Of Arrival (TDOA) estimation via sensor data correlation in the time domain with the purpose of implementation on the optical-core processor. they illustrate their results with the aid of numerical simulation and actual optical hardware runs. The major accomplishments of this research, in terms of computational speedup and numerical accurcy achieved via the deployment of optical processing technology, should be of substantial interest to the acoustic signal processing community.

  1. Discrete element simulation of localized deformation in stochastic distributed granular materials

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The deformation in granular material under loading conditions is a problem of great interest currently. In this paper,the micro-mechanism of the localized deformations in stochastically distributed granular materials is investigated based on the modi-fied distinct element method under the plane strain conditions,and the influences of the confining pressure,the initial void ratio and the friction coefficient on the localized deformation and the stability of granular materials are also studied. It is concluded,based on the numerical simulation testing,that two crossed shear sliding planes may occur inside the granular assembly,and deformation patterns vary with the increasing of transverse strain. These conclusions are in good agreement with the present experimental results. By tangential velocity profiles along the direction normal to the two shear sliding planes,it can be found that there are two different shear deformation patterns: one is the fluid-like shear mode and the other is the solid-like shear mode. At last,the influences of various material parameters or factors on localized deformation features and patterns of granular materials are discussed in detail.

  2. Discrete element simulation of localized deformation in stochastic distributed granular materials

    Institute of Scientific and Technical Information of China (English)

    WANG DengMing; ZHOU YouHe

    2008-01-01

    The deformation in granular material under loading conditions is a problem of great interest currently. In this paper, the micro-mechanism of the localized deformations in stochastically distributed granular materials is investigated based on the modi-fied distinct element method under the plane strain conditions, and the influences of the confining pressure, the initial void ratio and the friction coefficient on the localized deformation and the stability of granular materials are also studied. It is concluded, based on the numerical simulation testing, that two crossed shear sliding planes may occur inside the granular assembly, and deformation patterns vary with the increasing of transverse strain. These conclusions are in good agreement with the present experimental results. By tangential velocity profiles along the direction normal to the two shear sliding planes, it can be found that there are two different shear deformation patterns: one is the fluid-like shear mode and the other is the solid-like shear mode. At last, the influences of various material parameters or factors on localized deformation features and patterns of granular materials are discussed in detail.

  3. Localized Slip and Distributed Deformation in Oblique Settings: The Example of the Denali Fault System, Alaska

    Science.gov (United States)

    Vallage, A.; Deves, M.; Klinger, Y.; King, G. C. P.; Ruppert, N. A.

    2014-12-01

    Earthquakes occurring in oblique tectonic settings often partition between several faults that accommodate different components of the total motion. The 2002 Mw 7.9 Denali strike-slip earthquake, which azimuth varies by more than 50° over the 341 km total rupture length, offers a unique opportunity to look at partitioning in details, thanks to a large seismological dataset. Using a kinematic model that incorporates the obliquity of the plate-motion direction relative to the local fault azimuth, we show that the co-seismic deformation is consistent with the general northwestward displacement of the Wrangell block relative to stable North America. Hence we quantify the efficiency of the Denali fault to accommodate such oblique far field tectonic conditions by defining a coefficient of accommodation Ca, and we evaluate how much remains to be accommodated by distributed deformation off the strike-slip fault. We represent the distributed deformation using strain rosette for a catalog of 735 focal mechanisms between 1987 and 2011. We show that in oblique settings, such as in the Denali case, the aftershocks and the background seismicity are organized to accommodate the deformation that is not localized on the Denali strike-slip fault during the main earthquakes. Actually the westward increase of the obliquity increases the amount of such deformation accommodated through distributed thrust faults, leading to the westward widening of the Alaska Range. In addition we use a simple 2D boundary element elastic model to investigate the difference between geodetic data, showing a rotation of the block south of the fault, and our oblique boundary conditions. We show that it is possible to reproduce the rotation of such block while it is subjected to a northwestward oblique displacement applied on the curved Denali fault system.

  4. The Hierarchical Distribution of the Young Stellar Clusters in Six Local Star-forming Galaxies

    Science.gov (United States)

    Grasha, K.; Calzetti, D.; Adamo, A.; Kim, H.; Elmegreen, B. G.; Gouliermis, D. A.; Dale, D. A.; Fumagalli, M.; Grebel, E. K.; Johnson, K. E.; Kahre, L.; Kennicutt, R. C.; Messa, M.; Pellerin, A.; Ryon, J. E.; Smith, L. J.; Shabani, F.; Thilker, D.; Ubeda, L.

    2017-05-01

    We present a study of the hierarchical clustering of the young stellar clusters in six local (3-15 Mpc) star-forming galaxies using Hubble Space Telescope broadband WFC3/UVIS UV and optical images from the Treasury Program LEGUS (Legacy ExtraGalactic UV Survey). We identified 3685 likely clusters and associations, each visually classified by their morphology, and we use the angular two-point correlation function to study the clustering of these stellar systems. We find that the spatial distribution of the young clusters and associations are clustered with respect to each other, forming large, unbound hierarchical star-forming complexes that are in general very young. The strength of the clustering decreases with increasing age of the star clusters and stellar associations, becoming more homogeneously distributed after ˜40-60 Myr and on scales larger than a few hundred parsecs. In all galaxies, the associations exhibit a global behavior that is distinct and more strongly correlated from compact clusters. Thus, populations of clusters are more evolved than associations in terms of their spatial distribution, traveling significantly from their birth site within a few tens of Myr, whereas associations show evidence of disruption occurring very quickly after their formation. The clustering of the stellar systems resembles that of a turbulent interstellar medium that drives the star formation process, correlating the components in unbound star-forming complexes in a hierarchical manner, dispersing shortly after formation, suggestive of a single, continuous mode of star formation across all galaxies.

  5. Local knowledge, use pattern and geographical distribution of Moringa oleifera Lam. (Moringaceae) in Nigeria.

    Science.gov (United States)

    Popoola, Jacob O; Obembe, Olawole O

    2013-11-25

    All parts of Moringa oleifera are medicinally valuable with overlapping uses in treating myriads of ailments and diseases including body pains and weakness, fever, asthma, cough, blood pressure, arthritis, diabetes, epilepsy, wound, and skin infection. Moringa also has robust ability to challenge terminal diseases such as HIV/AIDs infections, chronic anemia, cancer, malaria and hemorrhage. The present study was to obtain ethnobotanical information on the use and local knowledge variation, geographical distribution, and to collect different landraces of Moringa oleifera from the different agro-ecological regions in Nigeria, for further studies. Ethnobotanical data were collected through face to face interviews, semi structured questionnaires and discussions with selected people who had knowledge about the plant. The fidelity level (FL %) and use value for different use categories of Moringa oleifera and its parts were estimated. The variation in ethnobotanical knowledge was evaluated by comparing the mean use value among ethnic, gender and age groups using sample T test. Garmi GPS was used to determine the locations (latitude and longitude) and height in different areas to assess the geographical spread of the species. Seven (7) categories of use (Food, medicine, fodder, fencing, firewood, gum and coagulant) were recorded for Moringa oleifera. Food and medicinal uses showed highest fidelity level while the leaves and the seeds were the plant parts most utilized for the same purposes. There were significant differences among the ethnic, gender and age groups regarding the ethno-botanical use value. The geographical distribution pattern shows that the Moringa oleifera is well distributed in all ecological zones of Nigeria, well adapted to the varied climatic conditions and gaining unprecedented awareness among the people. Though considered an introduced species, Moringa oleifera has found wide acceptance, recognition and usefulness among the various ethnicities in the

  6. Windows .NET Network Distributed Basic Local Alignment Search Toolkit (W.ND-BLAST

    Directory of Open Access Journals (Sweden)

    Oliver Melvin J

    2005-04-01

    Full Text Available Abstract Background BLAST is one of the most common and useful tools for Genetic Research. This paper describes a software application we have termed Windows .NET Distributed Basic Local Alignment Search Toolkit (W.ND-BLAST, which enhances the BLAST utility by improving usability, fault recovery, and scalability in a Windows desktop environment. Our goal was to develop an easy to use, fault tolerant, high-throughput BLAST solution that incorporates a comprehensive BLAST result viewer with curation and annotation functionality. Results W.ND-BLAST is a comprehensive Windows-based software toolkit that targets researchers, including those with minimal computer skills, and provides the ability increase the performance of BLAST by distributing BLAST queries to any number of Windows based machines across local area networks (LAN. W.ND-BLAST provides intuitive Graphic User Interfaces (GUI for BLAST database creation, BLAST execution, BLAST output evaluation and BLAST result exportation. This software also provides several layers of fault tolerance and fault recovery to prevent loss of data if nodes or master machines fail. This paper lays out the functionality of W.ND-BLAST. W.ND-BLAST displays close to 100% performance efficiency when distributing tasks to 12 remote computers of the same performance class. A high throughput BLAST job which took 662.68 minutes (11 hours on one average machine was completed in 44.97 minutes when distributed to 17 nodes, which included lower performance class machines. Finally, there is a comprehensive high-throughput BLAST Output Viewer (BOV and Annotation Engine components, which provides comprehensive exportation of BLAST hits to text files, annotated fasta files, tables, or association files. Conclusion W.ND-BLAST provides an interactive tool that allows scientists to easily utilizing their available computing resources for high throughput and comprehensive sequence analyses. The install package for W.ND-BLAST is

  7. Localization and distribution of fibrinogen C domain containing 1 (FIBCD1) in human tissues

    DEFF Research Database (Denmark)

    von Huth, Sebastian; Møller, Jesper Bonnet; Schlosser, Anders

    have previously shown that FIBCD1 is present at mucosal surfaces in the lung and large intestine. Aim: The present study investigates the distribution and localization of FIBCD1 in various healthy human tissues. Results: We used a monoclonal antibody directed towards the FIBCD1 ectodomain...... in an immunohistochemistry-based analysis and demonstrate that FIBCD1 protein is highly expressed at the apical surfaces of the epithelium throughout the gastrointestinal tract, in the uterus, testis, bladder, gallbladder and the salivary glands. To a lesser extent, FIBCD1 is expressed in the pancreas, the spleen...... and the tonsils. Moreover, using quantitative real-time PCR we demonstrate that FIBCD1 mRNA is highly expressed in the gastrointestinal tract, the lung, the adrenal gland and the testis, which is in coherence with our immunohistochemical findings. Conclusion: FIBCD1 is present at the apical epithelial surfaces...

  8. Characterization of Miniature Millimeter-Wave Vivaldi Antenna for Local Multipoint Distribution Service

    Science.gov (United States)

    Simon, Rainee N.; Lee, Richard Q.

    1997-01-01

    The paper presents first, an efficient measurement technique to characterize the input impedance of a Vivaldi antenna, second, a simple technique to impedance match a Vivaldi antenna to a 50 Ohm feed line and lastly, a desktop arrangement to determine the directional gain of a Vivaldi antenna. The characterization is done using a microwave wafer probe station, a ground-signal microwave probe, impedance standard substrate and an automatic network analyzer. The Vivaldi antenna with a matching transformer has a VSVIR close to unity and a gain of about 10 dB over the frequency band of 27.5 to 28.35 GHz which is allocated for local multipoint distribution service (LMDS).

  9. Local stress distribution around garnet inclusions during hydration of granulite in the Bergen Arcs, Norway

    Science.gov (United States)

    Centrella, Stephen; Vrijmoed, Johannes C.; Putnis, Andrew; Austrheim, Håkon

    2017-04-01

    The importance of heterogeneous stress and pressure distribution within a rock has been established over the last decades (see review in Tajčmanová et al., 2015). During a hydration reaction, depending on whether the system is open to mass transfer, the volume changes of the reaction may be accommodated by removing material into the fluid phase that leaves the system (Centrella et al., 2015; Centrella et al., 2016). The magnitudes and the spatial distribution of stress and pressure that evolve during such processes is largely unknown. We present here a natural example where a granulite is hydrated at amphibolite facies conditions from the Bergen Arcs in Norway. Granulitic garnet is associated with kyanite and quartz on one side, and amphibole-biotite on the other side. The first couple replaces the plagioclase of the granulite matrix whereas the second replaces the garnet. We use electron probe microanalysis (EPMA) and X-ray mapping to investigate the spatial and possible temporal relationships between these two parageneses. Gresens' analysis has been used to determine the mass balance and the local volume changes associated with the two reactions. The reaction to kyanite+quartz induces a loss in volume compared to the original plagioclase whereas the second reaction amphibole+biotite gains volume compared to the original garnet. The specific mass evolution associated with both reactions suggests a local mass balance probably associated with a single hydration event. Using the methodology of Vrijmoed & Podladchikov (2015) we test whether the microstructure may be partly related to the local stress heterogeneity around the garnet inclusion. We evaluate the phase assemblage and distribution at chemical equilibrium under a given input pressure field that can be computed with the Thermolab software. By varying the input pressure field using the Finite Element Method and comparing the resulting equilibrium assemblage to the real data an estimate of the local stress

  10. Filaments from the galaxy distribution and from the velocity field in the local universe

    CERN Document Server

    Libeskind, Noam I; Hoffman, Yehuda; Tully, R Brent; Courtois, Helene

    2015-01-01

    The cosmic web that characterizes the large-scale structure of the Universe can be quantified by a variety of methods. For example, large redshift surveys can be used in combination with point process algorithms to extract long curvilinear filaments in the galaxy distribution. Alternatively, given a full 3D reconstruction of the velocity field, kinematic techniques can be used to decompose the web into voids, sheets, filaments and knots. In this paper we look at how two such algorithms - the Bisous model and the velocity shear web - compare with each other in the local Universe (within 100 Mpc), finding good agreement. This is both remarkable and comforting, given that the two methods are radically different in ideology and applied to completely independent and different data sets. Unsurprisingly, the methods are in better agreement when applied to unbiased and complete data sets, like cosmological simulations, than when applied to observational samples. We conclude that more observational data is needed to i...

  11. Local distortion in Co-doped LSMO from entropy-maximized charge density distribution

    Energy Technology Data Exchange (ETDEWEB)

    Syed Ali, K.S. [Department of Physics, The Madura College, Madurai 625011 (India); Saravanan, R., E-mail: saragow@dataone.i [Department of Physics, The Madura College, Madurai 625011 (India); Pashchenko, A.V.; Pashchenko, V.P. [Galkin Donetsk Institute of Physics and Technology, National Academy of Sciences of Ukraine, Donetsk 83114 (Ukraine)

    2010-07-09

    Perovskite structure manganites La{sub 0.67}Sr{sub 0.22}Mn{sub 1.11-x}Co{sub x}O{sub 3} were prepared by the solid state reaction method. An X-ray analysis of the structure was undertaken using the Rietveld technique on the experimental powder X-ray diffraction data and, then, a charge density distribution study was undertaken, using the maximum entropy method (MEM). The charge density in the unit cell was reconstructed and the effect of Co{sup 3+} doping in the Mn-O matrix was studied. Local distortions due to Co doping were analyzed and the results are now discussed.

  12. STOMATOLOGIC ASPECTS IN THERAPY OF LOCALLY DISTRIBUTED CANCER OF ORAL CAVITY MUCUS

    Directory of Open Access Journals (Sweden)

    G. G. Matyakin

    2013-01-01

    Full Text Available Aim of the investigation: to improve prophylaxis of dental complications during the therapy in the patients with locally distributed cancer of oral cavity mucus.Materials. Results of sanation of oral cavity in 305 patients with cancer of oral and pharyngeal area are analyzed.Results. The best results are noted in the patients given surgical sanation before chemo-radial therapy. The most number of complications is observed when teeth were extracted after chemical therapy in the period of radial therapy at summary focal dose above 20 Gy as well as in the late periods after radial therapy.Conclusion. A complex of preventive measures with using haemostatic sponge with canamycin in such patients decreases the number of complications and the terms of healing of alveoli of extracted teeth.

  13. Light-sheet fluorescence imaging to localize cardiac lineage and protein distribution

    Science.gov (United States)

    Ding, Yichen; Lee, Juhyun; Ma, Jianguo; Sung, Kevin; Yokota, Tomohiro; Singh, Neha; Dooraghi, Mojdeh; Abiri, Parinaz; Wang, Yibin; Kulkarni, Rajan P.; Nakano, Atsushi; Nguyen, Thao P.; Fei, Peng; Hsiai, Tzung K.

    2017-02-01

    Light-sheet fluorescence microscopy (LSFM) serves to advance developmental research and regenerative medicine. Coupled with the paralleled advances in fluorescence-friendly tissue clearing technique, our cardiac LSFM enables dual-sided illumination to rapidly uncover the architecture of murine hearts over 10 by 10 by 10 mm3 in volume; thereby allowing for localizing progenitor differentiation to the cardiomyocyte lineage and AAV9-mediated expression of exogenous transmembrane potassium channels with high contrast and resolution. Without the steps of stitching image columns, pivoting the light-sheet and sectioning the heart mechanically, we establish a holistic strategy for 3-dimentional reconstruction of the “digital murine heart” to assess aberrant cardiac structures as well as the spatial distribution of the cardiac lineages in neonates and ion-channels in adults.

  14. Continuous-variable quantum key distribution with random intensity fluctuation of the local oscillator

    Science.gov (United States)

    Gui, Ming; Huang, Ming-Qiu; Liang, Lin-Mei

    2016-10-01

    In practical continuous-variable quantum key distribution (CVQKD) systems, due to environmental disturbance or some intrinsic imperfections of devices, inevitably the local oscillator (LO) employed in a coherent detection always fluctuates arbitrarily over time, which compromises the security and performance of practical CVQKD systems. In this paper, we investigate the performance of practical CVQKD systems with LO fluctuating randomly. By revising the measurement result of balanced homodyne detection and embedding fluctuation parameters into security analysis, we find that in addition to the average LO intensity, the fluctuation variance also severely affects the secret key rate. No secret key can be obtained if fluctuation variance is relatively large. This indicates that in a practical CVQKD, LO intensity should be well monitored and stabilized. Our research can be directly applied to improve the robustness of a practical CVQKD system as well as be used to optimize CVQKD protocols.

  15. First-Principles Momentum-Dependent Local Ansatz Wavefunction and Momentum Distribution Function Bands of Iron

    Science.gov (United States)

    Kakehashi, Yoshiro; Chandra, Sumal

    2016-04-01

    We have developed a first-principles local ansatz wavefunction approach with momentum-dependent variational parameters on the basis of the tight-binding LDA+U Hamiltonian. The theory goes beyond the first-principles Gutzwiller approach and quantitatively describes correlated electron systems. Using the theory, we find that the momentum distribution function (MDF) bands of paramagnetic bcc Fe along high-symmetry lines show a large deviation from the Fermi-Dirac function for the d electrons with eg symmetry and yield the momentum-dependent mass enhancement factors. The calculated average mass enhancement m*/m = 1.65 is consistent with low-temperature specific heat data as well as recent angle-resolved photoemission spectroscopy (ARPES) data.

  16. A new approach for beam hardening correction based on the local spectrum distributions

    Energy Technology Data Exchange (ETDEWEB)

    Rasoulpour, Naser; Kamali-Asl, Alireza, E-mail: a_kamali@sbu.ac.ir; Hemmati, Hamidreza

    2015-09-11

    Energy dependence of material absorption and polychromatic nature of x-ray beams in the Computed Tomography (CT) causes a phenomenon which called “beam hardening”. The purpose of this study is to provide a novel approach for Beam Hardening (BH) correction. This approach is based on the linear attenuation coefficients of Local Spectrum Distributions (LSDs) in the various depths of a phantom. The proposed method includes two steps. Firstly, the hardened spectra in various depths of the phantom (or LSDs) are estimated based on the Expectation Maximization (EM) algorithm for arbitrary thickness interval of known materials in the phantom. The performance of LSD estimation technique is evaluated by applying random Gaussian noise to transmission data. Then, the linear attenuation coefficients with regarding to the mean energy of LSDs are obtained. Secondly, a correction function based on the calculated attenuation coefficients is derived in order to correct polychromatic raw data. Since a correction function has been used for the conversion of the polychromatic data to the monochromatic data, the effect of BH in proposed reconstruction must be reduced in comparison with polychromatic reconstruction. The proposed approach has been assessed in the phantoms which involve less than two materials, but the correction function has been extended for using in the constructed phantoms with more than two materials. The relative mean energy difference in the LSDs estimations based on the noise-free transmission data was less than 1.5%. Also, it shows an acceptable value when a random Gaussian noise is applied to the transmission data. The amount of cupping artifact in the proposed reconstruction method has been effectively reduced and proposed reconstruction profile is uniform more than polychromatic reconstruction profile. - Highlights: • A novel Beam Hardening (BH) correction approach was described. • A new concept named Local Spectrum Distributions (LSDs) was used to BH

  17. Nanofiber of ultra-structured aluminum and zirconium oxide hybrid.

    Science.gov (United States)

    Kim, Hae-Won; Kim, Hyoun-Ee

    2006-02-01

    An internally ultrastructured Al- and Zr-oxide hybrid was developed into a nanofiber. As a precursor for the generation of nanofiber, a hybridized sol was prepared using the Pechini-type sol-gel process, whereby the Al- and Zr-metallic ions were to be efficiently distributed and stabilized within the polymeric network. The hybridized sol was subsequently electrospun and heat treated to a nanofiber with diameters of tens to hundreds of nanometers. The internal structure of the nanofiber was organized at the molecular level, with the Al- and Zr-oxide regions being interspaced at distances of less than ten nanometers. This ultrastructured Al- and Zr-oxide hybrid nanofiber is considered to be potentially applicable in numerous fields.

  18. Ultrastructural Study of Dermatic Tissues in Secondary Syphilis

    Institute of Scientific and Technical Information of China (English)

    张晓东; 脱朝伟; 张庆瑞; 宋芳吉

    2001-01-01

    Objective: For the purpose of understanding the changing process of syphilis histomorphology and its injury mechanism,the ultrastructure of dermatic tissues of secondary syphilis was studied.Methods: Different skin injury tissues of secondary syphilis patients, whose serum RPR and TPHA tests in the lab both appeared positive reaction, were observed through transmission electron microscope (TEM).Results: Inflammations appeared on epidermides and coria,a great deal of neutrocytes, lymphocytes and a small amount of plasma infiltrated them. Karyopyknosis, karyorrhexis,epicyte lysis and mitochondrion vacular degeneration occurred. Spirocheta pallida was distributed on intercellular substances, epicytes and coilagenous fibers. The epicytes were pressed to foveation. Conclusion The pathological change of characteristic tissue ultrastructure reported here is a histomorphological foundation to study the organism injury mechanism caused by syphilis.

  19. Ultrastructural researches on rabbit myxomatosis. Lymphnodal lesions.

    Science.gov (United States)

    Marcato, P S; Simoni, P

    1977-07-01

    Ultrastructural examination of head and neck lymph nodes in rabbits with spontaneous subacute myxomatosis showed fusion of immature reticuloendothelial cells which lead to the formation of polykarocytes. There was no ultrastructural evidence of viral infection of these polykaryocytes. Histiosyncytial lymphadenitis can be considered a specific lesion of myxomatosis.

  20. Ultrastructural basis of acute renal allograft rejection

    NARCIS (Netherlands)

    V.D. Vuzevski (Vojislav)

    1976-01-01

    textabstractAn attempt was made: I. to demonstrate the evolution and the time of onset of the ultrastructural morphological changes in the renal parenchyma and blood vessels, as well as the ultrastructural feature of the interstitial cellular infiltration in acute rejection of kidney allografts; 2.

  1. Oncocytic carcinoid of lung: an ultrastructural analysis.

    Science.gov (United States)

    Scharifker, D; Marchevsky, A

    1981-02-01

    A 52-year-old man with a typical carcinoid tumor of the lung in which the tumor cells displayed marked oncocytic metaplasia is presented. The clinicopathologic and ultrastructural differences with so-called oncocytic of the lung are discussed. The potential of Kulchitsky cell derivatives to undergo oncocytic metaplasma is documented ultrastructurally.

  2. Distribution and localization of the harmonic magnon modes in a one-dimensional Heisenberg spin glass

    Science.gov (United States)

    Boukahil, A.; Huber, D. L.

    1989-09-01

    The harmonic magnon modes in a one-dimensional Heisenberg spin glass having nearest-neighbor exchange interactions of fixed magnitude and random sign are investigated. The Lyapounov exponent is calculated for chains of 107-108 spins over the interval 0<=ω<=4J. In the low-frequency regime, ω<~0.1J, an anomalous behavior for the density of states ρ(ω)~ω-1/3 is established, consistent with earlier results obtained by Stinchcombe and Pimentel using transfer-matrix techniques; at higher frequencies, gaps appear in the spectrum. At low frequencies, the localization length diverges as ω-2/3. A formal connection is established between the spin glass and the one-dimensional discretized Schrödinger equation. By making use of the connection, it is shown that the theory of Derrida and Gardner, which was developed for weak potential disorder, can account quantitatively for the distribution and localization of the low-frequency magnon modes in the spin-glass model.

  3. Structure in the 3D Galaxy Distribution. II. Voids and Watersheds of Local Maxima and Minima

    Science.gov (United States)

    Way, M. J.; Gazis, P. R.; Scargle, Jeffrey D.

    2015-01-01

    The major uncertainties in studies of the multi-scale structure of the universe arise not from observational errors but from the variety of legitimate definitions and detection methods for individual structures. To facilitate the study of these methodological dependencies, we have carried out 12 different analyses defining structures in various ways. This has been done in a purely geometrical way by utilizing the HOP algorithm as a unique parameter-free method of assigning groups of galaxies to local density maxima or minima. From three density estimation techniques (smoothing kernels, Bayesian blocks, and self-organizing maps) applied to three data sets (the Sloan Digital Sky Survey Data Release 7, the Millennium simulation, and randomly distributed points) we tabulate information that can be used to construct catalogs of structures connected to local density maxima and minima. We also introduce a void finder that utilizes a method to assemble Delaunay tetrahedra into connected structures and characterizes regions empty of galaxies in the source catalog.

  4. STRUCTURE IN THE 3D GALAXY DISTRIBUTION. II. VOIDS AND WATERSHEDS OF LOCAL MAXIMA AND MINIMA

    Energy Technology Data Exchange (ETDEWEB)

    Way, M. J. [Also at NASA Goddard Institute for Space Studies, 2880 Broadway, New York, NY 10025, USA. (United States); Gazis, P. R.; Scargle, Jeffrey D., E-mail: Michael.J.Way@nasa.gov, E-mail: PGazis@sbcglobal.net, E-mail: Jeffrey.D.Scargle@nasa.gov [NASA Ames Research Center, Space Science Division, Moffett Field, CA 94035 (United States)

    2015-01-20

    The major uncertainties in studies of the multi-scale structure of the universe arise not from observational errors but from the variety of legitimate definitions and detection methods for individual structures. To facilitate the study of these methodological dependencies, we have carried out 12 different analyses defining structures in various ways. This has been done in a purely geometrical way by utilizing the HOP algorithm as a unique parameter-free method of assigning groups of galaxies to local density maxima or minima. From three density estimation techniques (smoothing kernels, Bayesian blocks, and self-organizing maps) applied to three data sets (the Sloan Digital Sky Survey Data Release 7, the Millennium simulation, and randomly distributed points) we tabulate information that can be used to construct catalogs of structures connected to local density maxima and minima. We also introduce a void finder that utilizes a method to assemble Delaunay tetrahedra into connected structures and characterizes regions empty of galaxies in the source catalog.

  5. Immunocytochemical and ultrastructural characterization of endocrine cells in the larval stomach of the frog Rana temporaria tadpoles: a comparison with adult specimens.

    Science.gov (United States)

    Villaro, A C; Rovira, J; Bodegas, M E; Burrell, M A; García-Ros, D; Sesma, P

    2001-10-01

    According to immunostaining and ultrastructural patterns, Rana temporaria tadpole stomach displays a well-differentiated endocrine population comprising, at least, six cellular types: ECL, EC [serotonin], D [somatostatin] - all three of them abundant -, P [bombesin] - less numerous -, CCK-8 [cholecystokinin/gastrin] and A [glucagon/glicentin] - both very scarce. Larval endocrine cells are mainly located in the surface epithelium and show open or closed morphologies. Cellular diversity is similar in tadpoles and frogs, with the exception of immunoreactivity for gastrin-17, found in adults in numerous cells. Larval cells display mature ultrastructural traits, although with smaller secretory granules. The different distribution of endocrine cells, which in adults are preferentially located in the glands, probably refers to different functional requirements. However, the rich vascular plexus present in larval mucosa may be an efficient transport medium of surface hormones to-gastric targets. The enhancement in adults of endocrine population and correlative increase in hormonal secretion indicates a more active functional role, probably related to the shift from herbivorous to carnivorous habits. In summary, the tadpole gastric endocrine population, although not as numerous as that of adult frogs, displays histological traits that indicate a relevant (immunoreactive and ultrastructural properties, cellular diversity) and specific (surface location, relative abundance of open-type cells) role of local regulatory factors in amphibian larval gastric function.

  6. Seasonal and Local Characteristics of Lightning Outages of Power Distribution Lines in Hokuriku Area

    Science.gov (United States)

    Sugimoto, Hitoshi; Shimasaki, Katsuhiko

    The proportion of the lightning outages in all outages on Japanese 6.6kV distribution lines is high with approximately 20 percent, and then lightning protections are very important for supply reliability of 6.6kV lines. It is effective for the lightning performance to apply countermeasures in order of the area where a large number of the lightning outages occur. Winter lightning occurs in Hokuriku area, therefore it is also important to understand the seasonal characteristics of the lightning outages. In summer 70 percent of the lightning outages on distribution lines in Hokuriku area were due to sparkover, such as power wire breakings and failures of pole-mounted transformers. However, in winter almost half of lightning-damaged equipments were surge arrester failures. The number of the lightning outages per lightning strokes detected by the lightning location system (LLS) in winter was 4.4 times larger than that in summer. The authors have presumed the occurrence of lightning outages from lightning stroke density, 50% value of lightning current and installation rate of lightning protection equipments and overhead ground wire by multiple regression analysis. The presumed results suggest the local difference in the lightning outages.

  7. Core-collapse supernova progenitor constraints using the spatial distributions of massive stars in local galaxies

    Science.gov (United States)

    Kangas, T.; Portinari, L.; Mattila, S.; Fraser, M.; Kankare, E.; Izzard, R. G.; James, P.; González-Fernández, C.; Maund, J. R.; Thompson, A.

    2017-01-01

    We studied the spatial correlations between the Hα emission and different types of massive stars in two local galaxies, the Large Magellanic Cloud (LMC) and Messier 33. We compared these to correlations derived for core-collapse supernovae (CCSNe) in the literature to connect CCSNe of different types with the initial masses of their progenitors and to test the validity of progenitor mass estimates which use the pixel statistics method. We obtained samples of evolved massive stars in both galaxies from catalogues with good spatial coverage and/or completeness, and combined them with coordinates of main-sequence stars in the LMC from the SIMBAD database. We calculated the spatial correlation of stars of different classes and spectral types with Hα emission. We also investigated the effects of distance, noise and positional errors on the pixel statistics method. A higher correlation with Hα emission is found to correspond to a shorter stellar lifespan, and we conclude that the method can be used as an indicator of the ages, and therefore initial masses, of SN progenitors. We find that the spatial distributions of type II-P SNe and red supergiants of appropriate initial mass (≳9 M⊙) are consistent with each other. We also find the distributions of type Ic SNe and WN stars with initial masses ≳20 M⊙ consistent, while supergiants with initial masses around 15 M⊙ are a better match for type IIb and II-L SNe. The type Ib distribution corresponds to the same stellar types as type II-P, which suggests an origin in interacting binaries. On the other hand, we find that luminous blue variable stars show a much stronger correlation with Hα emission than do type IIn SNe.

  8. Distributed Self-Organization Of Swarms To Find Globally $\\epsilon$-Optimal Routes To Locally Sensed Targets

    CERN Document Server

    Chattopadhyay, Ishanu

    2011-01-01

    The problem of near-optimal distributed path planning to locally sensed targets is investigated in the context of large swarms. The proposed algorithm uses only information that can be locally queried, and rigorous theoretical results on convergence, robustness, scalability are established, and effect of system parameters such as the agent-level communication radius and agent velocities on global performance is analyzed. The fundamental philosophy of the proposed approach is to percolate local information across the swarm, enabling agents to indirectly access the global context. A gradient emerges, reflecting the performance of agents, computed in a distributed manner via local information exchange between neighboring agents. It is shown that to follow near-optimal routes to a target which can be only sensed locally, and whose location is not known a priori, the agents need to simply move towards its "best" neighbor, where the notion of "best" is obtained by computing the state-specific language measure of an...

  9. local

    Directory of Open Access Journals (Sweden)

    Abílio Amiguinho

    2005-01-01

    Full Text Available The process of socio-educational territorialisation in rural contexts is the topic of this text. The theme corresponds to a challenge to address it having as main axis of discussion either the problem of social exclusion or that of local development. The reasons to locate the discussion in this last field of analysis are discussed in the first part of the text. Theoretical and political reasons are there articulated because the question is about projects whose intentions and practices call for the political both in the theoretical debate and in the choices that anticipate intervention. From research conducted for several years, I use contributions that aim at discuss and enlighten how school can be a potential locus of local development. Its identification and recognition as local institution (either because of those that work and live in it or because of those that act in the surrounding context are crucial steps to progressively constitute school as a partner for development. The promotion of the local values and roots, the reconstruction of socio-personal and local identities, the production of sociabilities and the equation and solution of shared problems were the dimensions of a socio-educative intervention, markedly globalising. This scenario, as it is argued, was also, intentionally, one of transformation and of deliberate change of school and of the administration of the educative territoires.

  10. Distributed Localization Algorithm for Wireless Sensor Network Based on Multidimensional Scaling and the Shortest Path Distance Correction

    Institute of Scientific and Technical Information of China (English)

    DING Yingqiang; DU Liufeng; YANG Ting; SUN Yugeng

    2009-01-01

    Sensor localization is crucial for the configuration and applications of wireless sensor network (WSN). A novel distributed localization algorithm, MDS-DC was proposed for wireless sensor network based on multidi-mensional scaling (MDS) and the shortest path distance correction. In MDS-DC, several local positioning regions with reasonable distribution were firstly constructed by an adaptive search algorithm, which ensures the mergence between the local relative maps of the adjacent local position regions and can reduce the number of common nodes in the network. Then, based on the relationships between the estimated distances and actual distances of anchors, the distance estimation vectors of sensors around anchors were corrected in each local positioning region. During the computations of the local relative coordinates, an iterative process, which is the combination of classical MDS algorithm and SMACOF algorithm, was applied. Finally, the global relative positions or absolute positions of sen-sors were obtained through merging the relative maps of all local positioning regions. Simulation results show that MDS-DC has better performances in positioning precision, energy efficiency and robustness to range error, which can meet the requirements of applications for sensor localization in WSN.

  11. Gas source localization and gas distribution mapping with a micro-drone

    Energy Technology Data Exchange (ETDEWEB)

    Neumann, Patrick P.

    2013-07-01

    The objective of this Ph.D. thesis is the development and validation of a VTOL-based (Vertical Take Off and Landing) micro-drone for the measurement of gas concentrations, to locate gas emission sources, and to build gas distribution maps. Gas distribution mapping and localization of a static gas source are complex tasks due to the turbulent nature of gas transport under natural conditions and becomes even more challenging when airborne. This is especially so, when using a VTOL-based micro-drone that induces disturbances through its rotors, which heavily affects gas distribution. Besides the adaptation of a micro-drone for gas concentration measurements, a novel method for the determination of the wind vector in real-time is presented. The on-board sensors for the flight control of the micro-drone provide a basis for the wind vector calculation. Furthermore, robot operating software for controlling the micro-drone autonomously is developed and used to validate the algorithms developed within this Ph.D. thesis in simulations and real-world experiments. Three biologically inspired algorithms for locating gas sources are adapted and developed for use with the micro-drone: the surge-cast algorithm (a variant of the silkworm moth algorithm), the zigzag / dung beetle algorithm, and a newly developed algorithm called ''pseudo gradient algorithm''. The latter extracts from two spatially separated measuring positions the information necessary (concentration gradient and mean wind direction) to follow a gas plume to its emission source. The performance of the algorithms is evaluated in simulations and real-world experiments. The distance overhead and the gas source localization success rate are used as main performance criteria for comparing the algorithms. Next, a new method for gas source localization (GSL) based on a particle filter (PF) is presented. Each particle represents a weighted hypothesis of the gas source position. As a first step, the PF

  12. Gas source localization and gas distribution mapping with a micro-drone

    Energy Technology Data Exchange (ETDEWEB)

    Neumann, Patrick P.

    2013-07-01

    The objective of this Ph.D. thesis is the development and validation of a VTOL-based (Vertical Take Off and Landing) micro-drone for the measurement of gas concentrations, to locate gas emission sources, and to build gas distribution maps. Gas distribution mapping and localization of a static gas source are complex tasks due to the turbulent nature of gas transport under natural conditions and becomes even more challenging when airborne. This is especially so, when using a VTOL-based micro-drone that induces disturbances through its rotors, which heavily affects gas distribution. Besides the adaptation of a micro-drone for gas concentration measurements, a novel method for the determination of the wind vector in real-time is presented. The on-board sensors for the flight control of the micro-drone provide a basis for the wind vector calculation. Furthermore, robot operating software for controlling the micro-drone autonomously is developed and used to validate the algorithms developed within this Ph.D. thesis in simulations and real-world experiments. Three biologically inspired algorithms for locating gas sources are adapted and developed for use with the micro-drone: the surge-cast algorithm (a variant of the silkworm moth algorithm), the zigzag / dung beetle algorithm, and a newly developed algorithm called ''pseudo gradient algorithm''. The latter extracts from two spatially separated measuring positions the information necessary (concentration gradient and mean wind direction) to follow a gas plume to its emission source. The performance of the algorithms is evaluated in simulations and real-world experiments. The distance overhead and the gas source localization success rate are used as main performance criteria for comparing the algorithms. Next, a new method for gas source localization (GSL) based on a particle filter (PF) is presented. Each particle represents a weighted hypothesis of the gas source position. As a first step, the PF

  13. Spectral distribution of local field potential responses to electrical stimulation of the retina

    Science.gov (United States)

    Wong, Yan T.; Halupka, Kerry; Kameneva, Tatiana; Cloherty, Shaun L.; Grayden, David B.; Burkitt, Anthony N.; Meffin, Hamish; Shivdasani, Mohit N.

    2016-06-01

    Objective. Different frequency bands of the local field potential (LFP) have been shown to reflect neuronal activity occurring at varying cortical scales. As such, recordings of the LFP may offer a novel way to test the efficacy of neural prostheses and allow improvement of stimulation strategies via neural feedback. Here we use LFP measurements from visual cortex to characterize neural responses to electrical stimulation of the retina. We aim to show that the LFP is a viable signal that contains sufficient information to optimize the performance of sensory neural prostheses. Approach. Clinically relevant electrode arrays were implanted in the suprachoroidal space of one eye in four felines. LFPs were simultaneously recorded in response to stimulation of individual electrodes using penetrating microelectrode arrays from the visual cortex. The frequency response of each electrode was extracted using multi-taper spectral analysis and the uniqueness of the responses was determined via a linear decoder. Main results. We found that cortical LFPs are reliably modulated by electrical stimulation of the retina and that the responses are spatially localized. We further characterized the spectral distribution of responses, with maximum information being contained in the low and high gamma bands. Finally, we found that LFP responses are unique to a large range of stimulus parameters (∼40) with a maximum conveyable information rate of 6.1 bits. Significance. These results show that the LFP can be used to validate responses to electrical stimulation of the retina and we provide the first steps towards using these responses to provide more efficacious stimulation strategies.

  14. Ultrastructural Alterations in the Epidermis of Patients with Tinea Pedis

    Directory of Open Access Journals (Sweden)

    Yurdagül Canberk

    2011-06-01

    Full Text Available Objective: Tinea pedis is the most common superficial fungal infection of the foot. Although light microscopic characteristics of tinea pedis have already been described and are well known, electron microscopic data is still lacking. In this study, we aimed to examine the ultrastructural changes in the epidermis of patients diagnosed with tinea pedis.Material and Methods: Biopsies were taken from the lesions between the toes of patients with untreated tinea pedis and from healthy volunteers with no fungal infections. The materials obtained were prepared for electron microscopy and examined by transmission electron microscope.Results: The ultrastructural examination revealed the following changes: (1 Disturbances in the form and organization of keratinocytes; (2 Irregular distribution and interlacing of tonofilament bundles in keratinocytes; (3 Disruption of desmosomes and detachment of adjoining keratinocytes; (4 Excessive widening of intercellular spaces between keratinocytes; (5 Dilatation of intercellular spaces between basal cells; (6 Degranulation of melanocytes in the stratum basale; (7 Migration of lymphocytes and polymorphonuclear leukocytes between keratinocytes in the stratum spinosum; (8 Degradation of basal lamina; (9 Pericapillary edema in the apillary dermis. Conclusion: The ultrastructural findings in tinea pedis are described and related to the clinical symptoms and histopathologic features of the disease.

  15. Distribution and abundance of house dust mites, Dermatophagoides spp., in different ecological localities in Esna City, Kena Governorate, Egypt.

    Science.gov (United States)

    Yassin, M K; Rifaat, M M

    1997-08-01

    The distribution and abundance of house dust mites, Dermatophagoides spp. were studied in July, September and November, 1995 in three different localities in Esna City, Kena Governorate, Upper Egypt. During these months, 15 houses were sampled in each locality. 87% of riverside houses were infested with mites where D. pteronyssinus dominated (80%) over D. farinae. Sixty percent of the valley houses sampled were infested, where D. farinae was dominant (66%). Densities of both Dermatophagoides spp., were considerably higher in riverside than in valley houses. Live mites were not found in the lightly infested houses sampled in the desert area (54% positive). Relative humidity, which varied in houses located in different climatic localities in Esna City, was noted to be the principal limiting factor influencing the distribution and abundance of both species. Temperature did not appear to be an important factor influencing the distribution and abundance.

  16. Localization in Self-Healing Autonomous Sensor Networks (SASNet): Studies on Cooperative Localization of Sensor Nodes using Distributed Maps

    Science.gov (United States)

    2008-01-01

    capteurs sans fil, pour proposer un nouveau schéma de localisation coopérative fondé sur l’analyse de composants curviligne (Curvilinear Component...à nouveau les avantages et désavantages de l’approche coopérative sélectionnée en comparaison aux autres approches, surtout l’approche itérative à...shortcomings of the cooperative approach that was selected. For a more detailed survey of the state-of- art of WSN localization, please refer to our

  17. Radiofrequency Field Distribution Assessment in Indoor Areas Covered by Wireless Local Area Network

    Directory of Open Access Journals (Sweden)

    HELBET, R.

    2009-02-01

    Full Text Available Electromagnetic environment becomes day by day more congested. Radio communication systems in the short range are now part of everyday life, and there is a need to also assess the pollution level due to their emission if we take into account human health and protection. There is consistent scientific evidence that environmental electromagnetic field may cause undesirable biological effects or even health hazards. Present paper aims at giving a view on exposure level due to wireless local area networks (WLAN emission solely, as part of environmental radiofrequency pollution. Highly accurate measurements were made indoor by using a frequency-selective measurement system and identifying the correct settings for an error-minimum assessment. We focused on analysis of the electric flux density distribution inside a room, in the far field of the emitting antennas, in case of a single network communication channel. We analyze the influence the network configuration parameters have on the field level. Distance from the source and traffic rate are also important parameters that affect the exposure level. Our measurements indicate that in the immediate vicinity of the WLAN stations the average field may reach as much as 13% from the present accepted reference levels given in the human exposure standards.

  18. Local field distribution near corrugated interfaces: Green function formalism versus effective medium theory

    Science.gov (United States)

    Choy, C. W.; Xiao, J. J.; Yu, K. W.

    2007-05-01

    The recent Green function formalism (GFF) has been used to study the local field distribution near a periodic interface separating two homogeneous media of different dielectric constants. In the GFF, the integral equations can be solved conveniently because of the existence of an analytic expression for the kernel (Greenian). However, due to a severe singularity in the Greenian, the formalism was formerly applied to compute the electric fields away from the interface region. In this work, we have succeeded in extending the GFF to compute the electric field inside the interface region by taking advantage of a sum rule. To our surprise, the strengths of the electric fields are quite similar in both media across the interface, despite of the large difference in dielectric constants. Moreover, we propose a simple effective medium approximation (EMA) to compute the electric field inside the interface region. We show that the EMA can indeed give an excellent description of the electric field, except near a surface plasmon resonance.

  19. Ground truth delineation for medical image segmentation based on Local Consistency and Distribution Map analysis.

    Science.gov (United States)

    Cheng, Irene; Sun, Xinyao; Alsufyani, Noura; Xiong, Zhihui; Major, Paul; Basu, Anup

    2015-01-01

    Computer-aided detection (CAD) systems are being increasingly deployed for medical applications in recent years with the goal to speed up tedious tasks and improve precision. Among others, segmentation is an important component in CAD systems as a preprocessing step to help recognize patterns in medical images. In order to assess the accuracy of a CAD segmentation algorithm, comparison with ground truth data is necessary. To-date, ground truth delineation relies mainly on contours that are either manually defined by clinical experts or automatically generated by software. In this paper, we propose a systematic ground truth delineation method based on a Local Consistency Set Analysis approach, which can be used to establish an accurate ground truth representation, or if ground truth is available, to assess the accuracy of a CAD generated segmentation algorithm. We validate our computational model using medical data. Experimental results demonstrate the robustness of our approach. In contrast to current methods, our model also provides consistency information at distributed boundary pixel level, and thus is invariant to global compensation error.

  20. Local and landscape-scale biotic correlates of mistletoe distribution in Mediterranean pine forests

    Energy Technology Data Exchange (ETDEWEB)

    Roura-Pascual, N.; Brotons, L.; Garcia, D.; Zamora, R.; Caceres, M. de

    2012-11-01

    The study of the spatial patterns of species allows the examination of hypotheses on the most plausible ecological processes and factors determining their distribution. To investigate the determinants of parasite species on Mediterranean forests at regional scales, occurrence data of the European Misletoe (Viscum album) in Catalonia (NE Iberian Peninsula) were extracted from forest inventory data and combined with different types of explanatory variables by means of generalized linear mixed models. The presence of mistletoes in stands of Pinus halepensis seems to be determined by multiple factors (climatic conditions, and characteristics of the host tree and landscape structure) operating at different spatial scales, with the availability of orchards of Olea europaea in the surroundings playing a relevant role. These results suggest that host quality and landscape structure are important mediators of plant-plant and plant-animal interactions and, therefore, management of mistletoe populations should be conducted at both local (i.e. clearing of infected host trees) and landscape scales (e.g. controlling the availability of nutrient-rich food sources that attract bird dispersers). Research and management at landscape-scales are necessary to anticipate the negative consequence of land-use changes in Mediterranean forests. (Author) 38 refs.

  1. [Spatial distribution of soil total nitrogen in Liangshui National Nature Reserve based on local model].

    Science.gov (United States)

    Zhen, Zhen; Guo, Zhi-ying; Zhao, Ying-hui; Li, Feng-ri; Wei, Qing-bin

    2016-02-01

    Based on LiDAR data of Liangshui National Nature Reserve, digital elevation model (DEM) was constructed and both primary terrain attributes (slope, aspect, profile curvature, etc.) and secondary terrain attributes (wetness index, sediment transport index, relative stream power index, etc.) were extracted. According to the theory of soil formation, geographically weighted regression (GWR) was applied to predict soil total nitrogen (TN) of the area, and the predicted results were compared with those of three traditional interpolation methods including inverse distance weighting (IDW), ordinary Kriging (OK) and universal Kriging (UK). Results showed that the prediction accuracy of GWR (77.4%) was higher than that of other three interpolation methods and the accuracy of IDW (69.4%) was higher than that of OK (63.5%) and UK (60.6%). The average of TN predicted by GWR reached 4.82 g . kg-1 in the study area and TN tended to be higher in the region with higher elevation, bigger wetness index and stronger relative stream power index than in other areas. Further, TN also varied partly with various aspects and slopes. Thus, local model using terrain attributes as independent variables was effective in predicting soil attribute distribution.

  2. Experimental Investigation on Local Air Age and Air Distribution of Stratum Ventilation

    Institute of Scientific and Technical Information of China (English)

    WANG Feng-hao; LI Yuan-bin; LIU Xiao-dong; WANG Xin-ke

    2009-01-01

    Because of the multiple problems on high energy consumption and unbalanced thermal comfort caused by the traditional ventilation system,a new concept of ventilation-stratum ventilation has been proposed,which sends the fresh air to the breathing zone directly.In this paper,the local air distributions of the displace-ment ventilation and the stratum ventilation in a model office were measured.The air ages in the breathing zone for the displacement ventilation and stratum ventilation were compared with the tracer gas concentration decay method.The decay curves of tracer gas concentration for these two ventilation systems in the breathing zonewere obtained, and the air ages were calculated.The experimental results show that the stratum ventilation sys-tem can offer lower air age for four mechanically ventilated cases in the breathing zone,and it can also provide better thermal comfort,which renews the air of breathing zone more quickly and reduces the energy consump-tion in some degree.The experimental investigation provides a theoretical basis for the application of stratum ventilation system.

  3. Explaining local-scale species distributions: relative contributions of spatial autocorrelation and landscape heterogeneity for an avian assemblage.

    Science.gov (United States)

    Mattsson, Brady J; Zipkin, Elise F; Gardner, Beth; Blank, Peter J; Sauer, John R; Royle, J Andrew

    2013-01-01

    Understanding interactions between mobile species distributions and landcover characteristics remains an outstanding challenge in ecology. Multiple factors could explain species distributions including endogenous evolutionary traits leading to conspecific clustering and endogenous habitat features that support life history requirements. Birds are a useful taxon for examining hypotheses about the relative importance of these factors among species in a community. We developed a hierarchical Bayes approach to model the relationships between bird species occupancy and local landcover variables accounting for spatial autocorrelation, species similarities, and partial observability. We fit alternative occupancy models to detections of 90 bird species observed during repeat visits to 316 point-counts forming a 400-m grid throughout the Patuxent Wildlife Research Refuge in Maryland, USA. Models with landcover variables performed significantly better than our autologistic and null models, supporting the hypothesis that local landcover heterogeneity is important as an exogenous driver for species distributions. Conspecific clustering alone was a comparatively poor descriptor of local community composition, but there was evidence for spatial autocorrelation in all species. Considerable uncertainty remains whether landcover combined with spatial autocorrelation is most parsimonious for describing bird species distributions at a local scale. Spatial structuring may be weaker at intermediate scales within which dispersal is less frequent, information flows are localized, and landcover types become spatially diversified and therefore exhibit little aggregation. Examining such hypotheses across species assemblages contributes to our understanding of community-level associations with conspecifics and landscape composition.

  4. Explaining local-scale species distributions: relative contributions of spatial autocorrelation and landscape heterogeneity for an avian assemblage.

    Directory of Open Access Journals (Sweden)

    Brady J Mattsson

    Full Text Available Understanding interactions between mobile species distributions and landcover characteristics remains an outstanding challenge in ecology. Multiple factors could explain species distributions including endogenous evolutionary traits leading to conspecific clustering and endogenous habitat features that support life history requirements. Birds are a useful taxon for examining hypotheses about the relative importance of these factors among species in a community. We developed a hierarchical Bayes approach to model the relationships between bird species occupancy and local landcover variables accounting for spatial autocorrelation, species similarities, and partial observability. We fit alternative occupancy models to detections of 90 bird species observed during repeat visits to 316 point-counts forming a 400-m grid throughout the Patuxent Wildlife Research Refuge in Maryland, USA. Models with landcover variables performed significantly better than our autologistic and null models, supporting the hypothesis that local landcover heterogeneity is important as an exogenous driver for species distributions. Conspecific clustering alone was a comparatively poor descriptor of local community composition, but there was evidence for spatial autocorrelation in all species. Considerable uncertainty remains whether landcover combined with spatial autocorrelation is most parsimonious for describing bird species distributions at a local scale. Spatial structuring may be weaker at intermediate scales within which dispersal is less frequent, information flows are localized, and landcover types become spatially diversified and therefore exhibit little aggregation. Examining such hypotheses across species assemblages contributes to our understanding of community-level associations with conspecifics and landscape composition.

  5. Explaining local-scale species distributions: relative contributions of spatial autocorrelation and landscape heterogeneity for an avian assemblage

    Science.gov (United States)

    Mattsson, Brady J.; Zipkin, Elise F.; Gardner, Beth; Blank, Peter J.; Sauer, John R.; Royle, J. Andrew

    2013-01-01

    Understanding interactions between mobile species distributions and landcover characteristics remains an outstanding challenge in ecology. Multiple factors could explain species distributions including endogenous evolutionary traits leading to conspecific clustering and endogenous habitat features that support life history requirements. Birds are a useful taxon for examining hypotheses about the relative importance of these factors among species in a community. We developed a hierarchical Bayes approach to model the relationships between bird species occupancy and local landcover variables accounting for spatial autocorrelation, species similarities, and partial observability. We fit alternative occupancy models to detections of 90 bird species observed during repeat visits to 316 point-counts forming a 400-m grid throughout the Patuxent Wildlife Research Refuge in Maryland, USA. Models with landcover variables performed significantly better than our autologistic and null models, supporting the hypothesis that local landcover heterogeneity is important as an exogenous driver for species distributions. Conspecific clustering alone was a comparatively poor descriptor of local community composition, but there was evidence for spatial autocorrelation in all species. Considerable uncertainty remains whether landcover combined with spatial autocorrelation is most parsimonious for describing bird species distributions at a local scale. Spatial structuring may be weaker at intermediate scales within which dispersal is less frequent, information flows are localized, and landcover types become spatially diversified and therefore exhibit little aggregation. Examining such hypotheses across species assemblages contributes to our understanding of community-level associations with conspecifics and landscape composition.

  6. 口虾蛄脑部褐脂质分布、组织学和超微结构特征研究%Morphology and histology of brain and ultrastructure and distribution of lipofuscin in brain of mantis shrimp Oratosquilla oratoria

    Institute of Scientific and Technical Information of China (English)

    范青松; 邢坤; 刘海映; 孙静娴; 陈雷; 刘奇

    2016-01-01

    为了解口虾蛄Oratosquilla oratoria脑部形态特征,揭示口虾蛄生理年龄与褐脂质( lipofuscin)含量的关系,采用组织切片、荧光成像和透射电镜技术,研究了口虾蛄脑中褐脂质的形态、分布和超微结构特征。结果表明:口虾蛄脑位于眼节之后、头脑甲最前方,体积较小; H. E组织切片下脑部细胞核颗粒呈圆形且均匀分布,直径为10~30μm,并在脑前桥细胞团( protocerebral bridge cell mass)区域分布较多;荧光显微镜下褐脂质颗粒呈黄褐色,直径为1~3μm,均匀分布于脑部;透射电镜下可见褐脂质颗粒多聚集分布于近细胞核区域,外被单层细胞器膜,染色密度较其他区域高且均匀。研究表明,整体上口虾蛄脑部褐脂质分布均匀,其形态与其他甲壳动物脑部褐脂质相似。%Morphology and histology of brain and ultrastructure and distribution of lipofuscin in brain were investi-gated in mantis shrimp Oratosquilla oratoria by biopsy, fluorescent microscopy and transmission electron microscopy to research the characterization of morphology, distribution and ultrastructure of lipofuscin in the brain. The brain was found in the rear of ophthalmic segment and in the small sharp point of cephalothorax, and histologically the rounded cerebral nucleus with diameter of 10-30 μm was distributed uniformly in the brain, especially aggregated in the protocerebral bridge cell mass. Under fluorescent microscopy, the lipofuscin granules with diameter of 1-3μm were yellow-brown in color and uniformly distributed in the brain. The transmission electron microscope re-vealed that lipofuscin was similar to the lysosome in that both were covered by single-layered organelles membrane, and in the granules filled with homogeneous electron-dense contents. The findings indicated that the lipofuscin granules in brain of the mantis shrimp had similar form to other crustaceans and uniform distribution in brain.

  7. The reorganization of root anatomy and ultrastructure of syncytial cells in tomato (Lycopersicon esculentum Mill. infected with potato cyst nematode (Globodera rostochiensis Woll.

    Directory of Open Access Journals (Sweden)

    Sylwia Fudali

    2011-01-01

    Full Text Available The sequence of anatomical and ultrastructural events leading to the syncytium development in tomato roots infected with Globodera rostochiensis was examined. The syncytia were preferentially induced in cortical or pericyclic cells in the elongation zone of root. They developed towards the vascular cylinder by incorporation of new cells via local cell wall breakdown. After surrounding primary phloem bundle and reaching xylem tracheary elements syncytia spread along vascular cylinder. Roots in primary state of growth seemed to be the best place for syncytium induction as syncytia formed in the zone of secondary growth were less hypertrophied. At the ultrastructural level syncytial elements were characterized by strong hypertrophy, breakdown of central vacuole, increased volume of cytoplasm, proliferation of organelles, and enlargement of nuclei. On the syncytial wall adjoining vessels the cell wall ingrowths were formed, while the syncytial walls at interface of phloem were considerably thickened. They lacked of functional plasmodesmata and did not form any ingrowths. Using immunofluorescent-labelling and immunogold-labelling methods tomato expansin 5 protein was localized in nematode infected roots. The distribution of LeEXP A5 was restricted only to the walls of syncytia. The protein distribution pattern indicated that LeEXP A5 could mediates cell wall expansion during hypertrophy of syncytial elements.

  8. Localization and distribution of magnetic chemotherapeutic drugs with magnetic targeting in rat brain

    Institute of Scientific and Technical Information of China (English)

    LI An-min; ZHANG Chuan-xiu; FU Xiang-ping; ZHANG Zhi-wen; XUE Qing-hui; YAN Run-min; YI Lin-hua

    2005-01-01

    Background Magnetic targeting therapy may be a new method for the treatment of malignent tumors. The purpose of this study was to investigate the localization and distribution of ferrofluid microsphere of human serum albumin methotrexate (FM-HSA-MTX) carriers in the brain and to explore the magnetic targeting chemotherapy for malignant brain tumor. Methods Ninety SD rats were divided into three groups: targeting group, non-magnetic targeting group, and control group. Synthesized FM-HSA-MTX carriers (MTX 25 mg/kg) were injected into the systemic circulation via the caudal vein (magnetic targeting group, n=30). A 0.6 T magnetic field was placed around the right hemisphere. The non-magnetic targeting group (n=30) was administered with FM-HSA-MTX without external magnetic field, meanwhile the control group (n=30) was treated with MTX and a magnetic field. Random serial sacrifices (n=10) were conducted at 15, 30 and 45 minutes after drug administration. Bilateral hemispheres were collected respectively, and analyzed for total MTX content. Results MTX content in the right hemisphere of the magnetic targeting group was significantly higher than that in the other two groups at 15, 30 and 45 minutes after drug administration (P<0.05) No difference was seen between the non-targeting group and control group. In the magnetic targeting group, MTX returned to the peak level [(0.564±0.018) mg/g, q15-45=32.252, P<0.05] 45 minutes after the injection but it deceased in the other two groups [non-magnetic targeting group: (0.060±0.015) mg/g, q15-45=9.245, P<0.05, control group: (0.074±0.045) mg/g, q15-45=6.299, P<0.05]. In the magnetic targeting group, the concentration of MTX in the right hemisphere was significantly higher than that in the left hemisphere (t45min=21.135, P=0.000) but no difference was observed between bilateral hemispheres in the other two groups (non-magnetic targeting group: t45min=0.434, P=0.670; control group: t45min=0.533, P=0.600). Conclusion In

  9. [Leaf epidermis ultrastructure of Zeugites (Poaceae: Panicoideae)].

    Science.gov (United States)

    Soriano, Ana María; Terrazas, Teresa; Dávila, Patricia

    2011-06-01

    The genus Zeugites comprises eleven species of neotropical grasses and it is principally distributed in Mexico, with some species extending to the Caribbean region, Central and South America. In this work, leaf epidermis ultrastructure of 11 species is described by the use of scanning electron microscopy. At least three specimens per species, that included herbarium and collected specimens, were used. An identification key and specific descriptions are included, in which the distinctive epidermal features are highlighted. The taxonomic valuable characters found were the following: presence or absence of prickles and macrohairs, intercostals short cells form and silica body form. Based on leaf epidermis characteristics, Zeugites species can be arranged into three groups: (1) species that lack prickles (Z. americana, Z. mexicana, Z. pringlei, Z. munroana and Z. sagittata); and lack macro hairs, with the exception of Z. pringlei; (2) species that have prickles (Z. latifolia and Z. smilacifolia); (3) species that have both, prickles and macrohairs (Z. capillaris, Z. hackelii, Z. pittieri and Z. sylvatica). The morphological features of leaf epidermis, support the relationship between the tribes Centotheceae and Paniceae.

  10. Local influences of geothermal anomalies on permafrost distribution in an active volcanic island (Deception Island, Antarctica)

    Science.gov (United States)

    Goyanes, G.; Vieira, G.; Caselli, A.; Cardoso, M.; Marmy, A.; Santos, F.; Bernardo, I.; Hauck, C.

    2014-11-01

    This study aims at understanding the spatial distribution and characteristics of the frozen and unfrozen terrain in an alluvial fan on Deception Island, which is an active strato-volcano located in the Bransfield Strait (South Shetland Islands) with recent eruptions in 1967, 1969 and 1970. The alluvial fan is dominated by debris-flow, run-off and rock fall processes and permafrost occurs in several parts in the vicinity of anomalous geothermal heat flux. The aim is to assess the ways volcanic activity controls permafrost development and associated geomorphic dynamics using shallow subsurface, surface and air temperature measurements as well as thaw depth and electrical resistivity tomography (ERT) surveys. Results show a temperature increase with depth in the lower part of the fan reaching 13 °C at 0.80 m depth, without the presence of permafrost. The shallow borehole located at this site showed a stable thermal stratification all year-round, with only the upper 0.20 m reacting to meteorological forcing. In the upper part of the alluvial fan and debris cones, c. 100 m from the coast, frozen ground is present at c. 0.70 m depth. There, the shallow borehole shows a good coupling with air temperatures and the thermal regime favours the presence of permafrost. ERT shows the lowest resistivity values in the lower part of the alluvial fan and a highly resistivity zone in the upper sector of the fan and in the debris cones. These large variations in resistivity mark the presence of a saline water wedge from the sea into the fan, reaching frozen ground conditions about 100 m inland. It can be shown that the volcano-hydrothermal activity only inhibits frost development very locally, with frozen ground conditions occurring about 100 m away.

  11. Trichomonas tenax: ultrastructure of giant forms.

    Science.gov (United States)

    Ribaux, C L; Joffre, A; Magloire, H

    1988-03-01

    Trichomonas tenax is a parasitic flagellate of the human mouth. The morphology and the ultrastructure of the protozoan are identical to those of other trichomonads. Giant forms suddenly appeared in a strain maintained in culture for two years. The structure and the ultrastructure of these abnormal forms were studied at the light and electron microscope level. Several nuclei, groups of flagella, undulating membranes and Golgi complexes were observed. The significance of these forms is still unknown.

  12. Studies of chain substitution caused sub-fibril level differences in stiffness and ultrastructure of wildtype and oim/oim collagen fibers using multifrequency-AFM and molecular modeling.

    Science.gov (United States)

    Li, Tao; Chang, Shu-Wei; Rodriguez-Florez, Naiara; Buehler, Markus J; Shefelbine, Sandra; Dao, Ming; Zeng, Kaiyang

    2016-11-01

    Molecular alteration in type I collagen, i.e., substituting the α2 chain with α1 chain in tropocollagen molecule, can cause osteogenesis imperfecta (OI), a brittle bone disease, which can be represented by a mouse model (oim/oim). In this work, we use dual-frequency Atomic Force Microscopy (AFM) and incorporated with molecular modeling to quantify the ultrastructure and stiffness of the individual native collagen fibers from wildtype (+/+) and oim/oim diseased mice humeri. Our work presents direct experimental evidences that the +/+ fibers have highly organized and compact ultrastructure and corresponding ordered stiffness distribution. In contrast, oim/oim fibers have ordered but loosely packed ultrastructure with uncorrelated stiffness distribution, as well as local defects. The molecular model also demonstrates the structural and molecular packing differences between +/+ and oim/oim collagens. The molecular mutation significantly altered sub-fibril structure and mechanical property of collagen fibers. This study can give the new insight for the mechanisms and treatment of the brittle bone disease.

  13. Clinicopathological, immunohistochemical, and ultrastructural study of 13 cases of melanotic schwannoma

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hong-ying; ZHANG Yuan-heng; YANG Guang-hua; CHEN Hui-jiao; WEI Bing; KE Qi; GUO Hua; YE Lü; BU Hong; YANG Ke

    2005-01-01

    Background Melanotic schwannoma is a rare variant of schwannoma composed of melanin-producing cells with ultrastructural features of schwann cells. The description of the course of the tumors differs somewhat, but it is generally considered as a benign lesion. We investigated the clinicopathologic features, immunophenotypes, and ultrastructural features of 13 patients with nonpsammomatous melanotic schwannoma (NPMS).Methods Tumor specimens of each patient were sectioned and stained with hematoxylin-eosin, Fontana-Masson, Prussian blue, and periodic acid-Schiff (PAS). Immunohistochemical markers such as S-100, Leu-7, HMB-45, Melan-A, CK, EMA, vimentin, GFAP, laminin, collagen Ⅳ and MIB-1 were detected with the Envision immunohistochemical staining method. Four of the cases were observed by electron microscopy.Results Of the 13 patients, 8 were male and 5 female, aged from 11 to 92 years (mean, 38.6 years). The tumor sites included the spinal nerve root (5 patients), cranial nerve (1), greater omentum (1), subcutaneous tissue (3), mesentery (1), bone (1) and mediastinum (1). Eleven patients were followed up for over 2 years, with a mean of 5.9 years. One patient (9.1%) with a primary tumor in the greater omentum developed another primary tumor of the same type in the subcutaneous tissue of the abdominal wall after the first operation. Local recurrence of the tumor was seen in 2 patients (18.2%). One patient (9.1%) showed the local recurrence and metastasis. Seven patients (63.6%) showed no evidence of the recurrence or metastasis. Grossly, all tumors were well-circumscribed and the gross findings were suggestive of melanin-containing tumors. The tumor was composed of spindled and epithelioid cells with abundant intracytoplasmic melanin pigments. Nuclei were round and contained delicate, evenly distributed chromatins as well as small, distinct nucleoli. In some areas, the nucleoli were large and prominent. Rare mitoses were seen in most lesions except the larger

  14. Assessing water resources in Azerbaijan using a local distributed model forced and constrained with global data

    Science.gov (United States)

    Bouaziz, Laurène; Hegnauer, Mark; Schellekens, Jaap; Sperna Weiland, Frederiek; ten Velden, Corine

    2017-04-01

    In many countries, data is scarce, incomplete and often not easily shared. In these cases, global satellite and reanalysis data provide an alternative to assess water resources. To assess water resources in Azerbaijan, a completely distributed and physically based hydrological wflow-sbm model was set-up for the entire Kura basin. We used SRTM elevation data, a locally available river map and one from OpenStreetMap to derive the drainage direction network at the model resolution of approximately 1x1 km. OpenStreetMap data was also used to derive the fraction of paved area per cell to account for the reduced infiltration capacity (c.f. Schellekens et al. 2014). We used the results of a global study to derive root zone capacity based on climate data (Wang-Erlandsson et al., 2016). To account for the variation in vegetation cover over the year, monthly averages of Leaf Area Index, based on MODIS data, were used. For the soil-related parameters, we used global estimates as provided by Dai et al. (2013). This enabled the rapid derivation of a first estimate of parameter values for our hydrological model. Digitized local meteorological observations were scarce and available only for limited time period. Therefore several sources of global meteorological data were evaluated: (1) EU-WATCH global precipitation, temperature and derived potential evaporation for the period 1958-2001 (Harding et al., 2011), (2) WFDEI precipitation, temperature and derived potential evaporation for the period 1979-2014 (by Weedon et al., 2014), (3) MSWEP precipitation (Beck et al., 2016) and (4) local precipitation data from more than 200 stations in the Kura basin were available from the NOAA website for a period up to 1991. The latter, together with data archives from Azerbaijan, were used as a benchmark to evaluate the global precipitation datasets for the overlapping period 1958-1991. By comparing the datasets, we found that monthly mean precipitation of EU-WATCH and WFDEI coincided well

  15. Phase-space structure in the local dark matter distribution and its signature in direct detection experiments

    NARCIS (Netherlands)

    Vogelsberger, Mark; Helmi, Amina; Springel, Volker; White, Simon D. M.; Wang, Jie; Frenk, Carlos S.; Jenkins, Adrian; Ludlow, Aaron; Navarro, Julio F.

    2009-01-01

    We study predictions for dark matter (DM) phase-space structure near the Sun based on high-resolution simulations of six galaxy haloes taken from the Aquarius project. The local DM density distribution is predicted to be remarkably smooth; the density at the Sun differs from the mean over a best-fit

  16. Phase-space structure in the local dark matter distribution and its signature in direct detection experiments

    NARCIS (Netherlands)

    Vogelsberger, Mark; Helmi, Amina; Springel, Volker; White, Simon D. M.; Wang, Jie; Frenk, Carlos S.; Jenkins, Adrian; Ludlow, Aaron; Navarro, Julio F.

    2008-01-01

    We study predictions for dark matter phase-space structure near the Sun based on high-resolution simulations of six galaxy halos taken from the Aquarius Project. The local DM density distribution is predicted to be remarkably smooth; the density at the Sun differs from the mean over a best-fit ellip

  17. Thermo-economic optimization of secondary distribution network of low temperature district heating network under local conditions of South Korea

    DEFF Research Database (Denmark)

    Park, Byung Sik; Imran, Muhammad; Hoon, Im-Yong

    2017-01-01

    A secondary distribution network of a low temperature district heating system is designed and optimized for a residential apartment complex under the local conditions of South Korea in the TRNSYS simulation environment. The residential apartment complex is a typical example of Korean residential...

  18. SPIN POLARIZATION AND MAGNETIC DICHROISM IN PHOTOEMISSION FROM CORE AND VALENCE STATES IN LOCALIZED MAGNETIC SYSTEMS .3. ANGULAR-DISTRIBUTIONS

    NARCIS (Netherlands)

    THOLE, BT; VANDERLAAN, G

    1994-01-01

    A general analysis is presented for angle-dependent photoemission from magnetic and oriented atoms using linearly and circularly polarized x-rays. The anisotropy in the angular distribution in a localized material is due to the polarization of the photon, the polarization of the shell from which the

  19. Carriers' localization and thermal redistribution in post growth voluntarily tuned quantum dashes' size/composition distribution

    Energy Technology Data Exchange (ETDEWEB)

    Alouane, M.H. Hadj, E-mail: helmi.alouane@yahoo.fr [Université de Monastir, Laboratoire de Micro-Optoélectronique et Nanostructures (LMON), Faculté des Sciences, 5019 Monastir (Tunisia); Université de Lyon, Institut des Nanotechnologies de Lyon (INL)-UMR5270-CNRS, UMR-5270 CNRS, Ecole cenrale de Lyon, 69134 Ecully (France); Helali, A. [Université de Monastir, Laboratoire de Micro-Optoélectronique et Nanostructures (LMON), Faculté des Sciences, 5019 Monastir (Tunisia); Morris, D. [Institut Interdisciplinaire d' Innovation Technologique (3IT), Université de Sherbrooke, Sherbrooke (Québec), Canada J1K 2R1 (Canada); Maaref, H. [Université de Monastir, Laboratoire de Micro-Optoélectronique et Nanostructures (LMON), Faculté des Sciences, 5019 Monastir (Tunisia); Aimez, V. [Institut Interdisciplinaire d' Innovation Technologique (3IT), Université de Sherbrooke, Sherbrooke (Québec), Canada J1K 2R1 (Canada); Salem, B. [Laboratoire des Technologies de la Microélectronique (LTM)–UMR 5129 CNRS-UJF, CEA Grenoble, 17 Rue des Martyrs, F-38054 Grenoble (France); Gendry, M. [Université de Lyon, Institut des Nanotechnologies de Lyon (INL)-UMR5270-CNRS, UMR-5270 CNRS, Ecole cenrale de Lyon, 69134 Ecully (France); and others

    2014-01-15

    This paper treats the impact of post growth tuned InAs/InP quantum dashes' (QDas) size/composition distribution on carriers' localization and thermal redistribution. The spread of this distribution depends on the experimental conditions used for the phosphorus ion implantation enhanced intermixing process. Atypical temperature-dependent luminescence properties have been observed and found to be strongly dependent on the amount of QDas size/composition dispersion. The experimental results have been reproduced by a model that takes into account the width of the QDas localized states distribution and consequent thermally induced carriers' redistribution. This model gives critical temperature values marking the beginning and the end of carriers delocalization and thermal transfer processes via an intermixing induced carrier's transfer channel located below the wetting layer states. -- Highlights: • We examine optical properties of post growth tuned QDas size/composition distribution. • Carriers' localization and thermal redistribution within inhomogeneously intermixed QDas are the origin of the atypical temperature-dependent luminescence properties. • Localized states ensemble's model is successively used to interpret the experimental results. • The carriers thermal transfer processes occur via an intermixing induced channel located below the wetting layer states. • Intermixing degree strongly influence the critical temperatures marking the beginning and the end of the carriers thermal transfer processes.

  20. Discrete, 3D distributed, linear imaging methods of electric neuronal activity. Part 1: exact, zero error localization

    CERN Document Server

    Pascual-Marqui, Roberto D

    2007-01-01

    This paper deals with the EEG/MEG neuroimaging problem: given measurements of scalp electric potential differences (EEG: electroencephalogram) and extracranial magnetic fields (MEG: magnetoencephalogram), find the 3D distribution of the generating electric neuronal activity. This problem has no unique solution. Only particular solutions with "good" localization properties are of interest, since neuroimaging is concerned with the localization of brain function. In this paper, a general family of linear imaging methods with exact, zero error localization to point-test sources is presented. One particular member of this family is sLORETA (standardized low resolution brain electromagnetic tomography; Pascual-Marqui, Methods Find. Exp. Clin. Pharmacol. 2002, 24D:5-12; http://www.unizh.ch/keyinst/NewLORETA/sLORETA/sLORETA-Math01.pdf). It is shown here that sLORETA has no localization bias in the presence of measurement and biological noise. Another member of this family, denoted as eLORETA (exact low resolution bra...

  1. Age distribution patterns of human gene families: divergent for Gene Ontology categories and concordant between different subcellular localizations.

    Science.gov (United States)

    Liu, Gangbiao; Zou, Yangyun; Cheng, Qiqun; Zeng, Yanwu; Gu, Xun; Su, Zhixi

    2014-04-01

    The age distribution of gene duplication events within the human genome exhibits two waves of duplications along with an ancient component. However, because of functional constraint differences, genes in different functional categories might show dissimilar retention patterns after duplication. It is known that genes in some functional categories are highly duplicated in the early stage of vertebrate evolution. However, the correlations of the age distribution pattern of gene duplication between the different functional categories are still unknown. To investigate this issue, we developed a robust pipeline to date the gene duplication events in the human genome. We successfully estimated about three-quarters of the duplication events within the human genome, along with the age distribution pattern in each Gene Ontology (GO) slim category. We found that some GO slim categories show different distribution patterns when compared to the whole genome. Further hierarchical clustering of the GO slim functional categories enabled grouping into two main clusters. We found that human genes located in the duplicated copy number variant regions, whose duplicate genes have not been fixed in the human population, were mainly enriched in the groups with a high proportion of recently duplicated genes. Moreover, we used a phylogenetic tree-based method to date the age of duplications in three signaling-related gene superfamilies: transcription factors, protein kinases and G-protein coupled receptors. These superfamilies were expressed in different subcellular localizations. They showed a similar age distribution as the signaling-related GO slim categories. We also compared the differences between the age distributions of gene duplications in multiple subcellular localizations. We found that the distribution patterns of the major subcellular localizations were similar to that of the whole genome. This study revealed the whole picture of the evolution patterns of gene functional

  2. Regional distribution shifts help explain local changes in wintering raptor abundance: implications for interpreting population trends

    National Research Council Canada - National Science Library

    Paprocki, Neil; Heath, Julie A; Novak, Stephen J

    2014-01-01

    .... Recognizing the influence of distribution shifts on population indices will be an important part of interpreting trends within management units because current practice often assumes that changes...

  3. Distributed High Accuracy Peer-to-Peer Localization in Mobile Multipath Environments

    CERN Document Server

    Ekambaram, Venkatesan

    2010-01-01

    In this paper we consider the problem of high accuracy localization of mobile nodes in a multipath-rich environment where sub-meter accuracies are required. We employ a peer to peer framework where the vehicles/nodes can get pairwise multipath-degraded ranging estimates in local neighborhoods together with a fixed number of anchor nodes. The challenge is to overcome the multipath-barrier with redundancy in order to provide the desired accuracies especially under severe multipath conditions when the fraction of received signals corrupted by multipath is dominating. We invoke a message passing analytical framework based on particle filtering and reveal its high accuracy localization promise through simulations.

  4. The Reviewing of Distributed Power Sources Impact on Fallout’s Localization in 22 kV Network

    Directory of Open Access Journals (Sweden)

    Peter Bracinik

    2008-01-01

    Full Text Available The aim of this paper is to point out some facts that will occur by fault localization in 22 kV networks after the implementation of distributed power sources, especially wind power plants. This paper describes possible connection of these sources into power system in regard to their rated output. It also presents short theoretical background for short circuit calculation in 22 kV network. Then several examples explaining how the point of wind power plant connection can influence network’s operation during short-circuits and consequential fault’s localization are described in the second part of this paper

  5. Dutch gas distribution grid goes green: decision support tool for local biogas utilization

    NARCIS (Netherlands)

    Weidenaar, T.D.

    2011-01-01

    A Decision Support Tool (DST) has been developed that will aid Distribution Service Operators (DSOs) in their decision making process on which investments to make in the gas distribution grid in order to facilitate the use of biogas. The DST considers both the conversion of biogas to electricity as

  6. Complex frequencies and field distributions of localized surface plasmon modes in graphene-coated subwavelength wires

    Science.gov (United States)

    Cuevas, Mauro; Riso, Máximo A.; Depine, Ricardo A.

    2016-04-01

    In this work we study the modal characteristics of localized surface plasmons in graphene-coated, circular cross-section wires. Localized surface plasmons are represented in terms of cylindrical multipole partial waves characterized by discrete, complex frequencies that depend on the size of the wire and can be dynamically tuned via a gate voltage. We consider both intrinsically nonplasmonic wires and intrinsically plasmonic wires. In the first case the localized surface plasmons are introduced by the graphene coating, whereas in the second case the localized eigenmodes of the graphene coating are expected to hybridize those already existing in the bare wire. We show that the approach presented here, valid for particle sizes where the retardation effects can be significant, is in good agreement with analytical expressions obtained in the limit when particle size is very small compared to the wavelength of the eigenmode and with results indirectly determined from scattering cross-section spectra.

  7. Pion-to-photon transition distribution amplitudes in the non-local chiral quark model

    CERN Document Server

    Kotko, Piotr

    2008-01-01

    We apply the non-local chiral quark model to study vector and axial pion-to-photon transition amplitudes that are needed as a nonperturbative input to estimate the cross section of pion annihilation into the real and virtual photon. We use a simple form of the non-locality that allows to perform all calculations in the Minkowski space and guaranties polynomiality of the TDA's. We note only residual dependence on the precise form of the cut-off function, however vector TDA that is symmetric in skewedness parameter in the local quark model is no longer symmetric in the non-local case. We calculate also the transition form-factors and compare them with existing experimental parametrizations.

  8. Reptilian spermatogenesis: A histological and ultrastructural perspective.

    Science.gov (United States)

    Gribbins, Kevin M

    2011-07-01

    Until recently, the histology and ultrastructural events of spermatogenesis in reptiles were relatively unknown. Most of the available morphological information focuses on specific stages of spermatogenesis, spermiogenesis, and/or of the mature spermatozoa. No study to date has provided complete ultrastructural information on the early events of spermatogenesis, proliferation and meiosis in class Reptilia. Furthermore, no comprehensive data set exists that describes the ultrastructure of the entire ontogenic progression of germ cells through the phases of reptilian spermatogenesis (mitosis, meiosis and spermiogenesis). The purpose of this review is to provide an ultrastructural and histological atlas of spermatogenesis in reptiles. The morphological details provided here are the first of their kind and can hopefully provide histological information on spermatogenesis that can be compared to that already known for anamniotes (fish and amphibians), birds and mammals. The data supplied in this review will provide a basic model that can be utilized for the study of sperm development in other reptiles. The use of such an atlas will hopefully stimulate more interest in collecting histological and ultrastructural data sets on spermatogenesis that may play important roles in future nontraditional phylogenetic analyses and histopathological studies in reptiles.

  9. Precipitation Recycling and the Vertical Distribution of Local and Remote Sources of Water for Precipitation

    Science.gov (United States)

    Bosilovich, Michael G.; Atlas, Robert (Technical Monitor)

    2002-01-01

    Precipitation recycling is defined as the amount of water that evaporates from a region that precipitates within the same region. This is also interpreted as the local source of water for precipitation. In this study, the local and remote sources of water for precipitation have been diagnosed through the use of passive constituent tracers that represent regional evaporative sources along with their transport and precipitation. We will discuss the differences between this method and the simpler bulk diagnostic approach to precipitation recycling. A summer seasonal simulation has been analyzed for the regional sources of the United States Great Plains precipitation. While the tropical Atlantic Ocean (including the Gulf of Mexico) and the local continental sources of precipitation are most dominant, the vertically integrated column of water contains substantial water content originating from the Northern Pacific Ocean, which is not precipitated. The vertical profiles of regional water sources indicate that local Great Plains source of water dominates the lower troposphere, predominantly in the PBL. However, the Pacific Ocean source is dominant over a large portion of the middle to upper troposphere. The influence of the tropical Atlantic Ocean is reasonably uniform throughout the column. While the results are not unexpected given the formulation of the model's convective parameterization, the analysis provides a quantitative assessment of the impact of local evaporation on the occurrence of convective precipitation in the GCM. Further, these results suggest that local source of water is not well mixed throughout the vertical column.

  10. Ultrastructural investigation of human sperm from asthenozoospermic men

    Directory of Open Access Journals (Sweden)

    S. Sh. Khayat

    2014-11-01

    Full Text Available Ultrastructure of the flagellum is highly conserved and is composed of a number of cytoskeletal elements whose proper assembly is critical for sperm motility. Ultrastructural mechanisms damage as cause of asthenozoospermia development are discussed.

  11. Ultrastructural investigation of human sperm from asthenozoospermic men

    Directory of Open Access Journals (Sweden)

    S. Sh. Khayat

    2012-01-01

    Full Text Available Ultrastructure of the flagellum is highly conserved and is composed of a number of cytoskeletal elements whose proper assembly is critical for sperm motility. Ultrastructural mechanisms damage as cause of asthenozoospermia development are discussed.

  12. The Study of Environmental Crisis and Local Distribution of Green Space in Tehran City

    Directory of Open Access Journals (Sweden)

    K. zayyari

    2012-01-01

    .- Necessity to review and codify land preservation regulation to protect trees with usage as green are and operating such area as one of the top priority for saving green life of the city. This must be implemented through a comprehensive urban plan with executive guarantees. Support from legislative bodies for preservation of the green area in the city. Keywords: environmental crisis, green space per capita, green space local distribution, Tehran, urban parks. ReferencesEbrahimzadeh, E, and Ebadi Joe Kndan, I, (2008, an analysis of distribution space - a place for green space in the three cities of Zahedan, Journal of Geography and Development, No 11, Tehran, P1. Bahrain, H, (1990, used in meteorological studies of air pollution in urban design (specific examples of Tehran, Journal of Environmental Studies, No 18, Tehran, P1. Behbahani, (1994, to determine the pattern of Tehran's parks, green space, education Journal, No 8, P1. Bijan Zad, M.R, (1990, of green space in Tehran, published by the Cultural Office of the Jihad, Tehran, P1. Pour Mohammadi, M.R, (2003, land use, urban planning, published by Samt, Tehran, P4. Tvahn, A., (2004, Editor's Note Journal of municipalities, No 17, Tehran, P1. Harimi, A., (1999, organizing neighborhood parks and green space, Evin, Supervisor Pourahmad, Ahmad, Tehran University, Department of Geography and Urban Planning. Hekmati, J, (1992, designed gardens and parks, published by Farhang Jame, Tehran, P1. Dabiri, F., and Maleki, M, (2009, review the legal capacity to destroy and change associated with green spaces, publications, research and planning in Tehran, Tehran, P3.Rohani, Gh, (1986, garden design and construction of green space, part publisher, Tehran, P3.Statistical Yearbook of Tehran, (2006,Tehran. P1. Statistics Organization of Iran (1996 and 2006, General Census of Population and Housing Tehran. Saeed Nia, A., (1368, place in Tehran, Iranian Journal of Environmental Studies, No. 15, Tehran, P1. Sharifi, M, (1992, Introduction to

  13. Ecological and social factors affecting the local habitat distribution of western sandpipers wintering at Bah?Santa Mar? Northwest Mexico

    OpenAIRE

    2005-01-01

    The process of habitat selection often requires individuals to choose among habitats that differ in foraging profitability and predation danger. The local habitat distribution of Western Sandpipers (Calidris maur~] was studied at Bahia Santa Maria, northwest Mexico, for three non-breeding seasons (1 999-2002). Western Sandpipers are highly sexually dimorphic, males being lighter and smaller-billed than females, and thus males may use visual foraging more often, be more susceptible to interfer...

  14. Distributed Bayesian Computation and Self-Organized Learning in Sheets of Spiking Neurons with Local Lateral Inhibition

    Science.gov (United States)

    Bill, Johannes; Buesing, Lars; Habenschuss, Stefan; Nessler, Bernhard; Maass, Wolfgang; Legenstein, Robert

    2015-01-01

    During the last decade, Bayesian probability theory has emerged as a framework in cognitive science and neuroscience for describing perception, reasoning and learning of mammals. However, our understanding of how probabilistic computations could be organized in the brain, and how the observed connectivity structure of cortical microcircuits supports these calculations, is rudimentary at best. In this study, we investigate statistical inference and self-organized learning in a spatially extended spiking network model, that accommodates both local competitive and large-scale associative aspects of neural information processing, under a unified Bayesian account. Specifically, we show how the spiking dynamics of a recurrent network with lateral excitation and local inhibition in response to distributed spiking input, can be understood as sampling from a variational posterior distribution of a well-defined implicit probabilistic model. This interpretation further permits a rigorous analytical treatment of experience-dependent plasticity on the network level. Using machine learning theory, we derive update rules for neuron and synapse parameters which equate with Hebbian synaptic and homeostatic intrinsic plasticity rules in a neural implementation. In computer simulations, we demonstrate that the interplay of these plasticity rules leads to the emergence of probabilistic local experts that form distributed assemblies of similarly tuned cells communicating through lateral excitatory connections. The resulting sparse distributed spike code of a well-adapted network carries compressed information on salient input features combined with prior experience on correlations among them. Our theory predicts that the emergence of such efficient representations benefits from network architectures in which the range of local inhibition matches the spatial extent of pyramidal cells that share common afferent input. PMID:26284370

  15. Distributed Bayesian Computation and Self-Organized Learning in Sheets of Spiking Neurons with Local Lateral Inhibition.

    Science.gov (United States)

    Bill, Johannes; Buesing, Lars; Habenschuss, Stefan; Nessler, Bernhard; Maass, Wolfgang; Legenstein, Robert

    2015-01-01

    During the last decade, Bayesian probability theory has emerged as a framework in cognitive science and neuroscience for describing perception, reasoning and learning of mammals. However, our understanding of how probabilistic computations could be organized in the brain, and how the observed connectivity structure of cortical microcircuits supports these calculations, is rudimentary at best. In this study, we investigate statistical inference and self-organized learning in a spatially extended spiking network model, that accommodates both local competitive and large-scale associative aspects of neural information processing, under a unified Bayesian account. Specifically, we show how the spiking dynamics of a recurrent network with lateral excitation and local inhibition in response to distributed spiking input, can be understood as sampling from a variational posterior distribution of a well-defined implicit probabilistic model. This interpretation further permits a rigorous analytical treatment of experience-dependent plasticity on the network level. Using machine learning theory, we derive update rules for neuron and synapse parameters which equate with Hebbian synaptic and homeostatic intrinsic plasticity rules in a neural implementation. In computer simulations, we demonstrate that the interplay of these plasticity rules leads to the emergence of probabilistic local experts that form distributed assemblies of similarly tuned cells communicating through lateral excitatory connections. The resulting sparse distributed spike code of a well-adapted network carries compressed information on salient input features combined with prior experience on correlations among them. Our theory predicts that the emergence of such efficient representations benefits from network architectures in which the range of local inhibition matches the spatial extent of pyramidal cells that share common afferent input.

  16. Distributed Bayesian Computation and Self-Organized Learning in Sheets of Spiking Neurons with Local Lateral Inhibition.

    Directory of Open Access Journals (Sweden)

    Johannes Bill

    Full Text Available During the last decade, Bayesian probability theory has emerged as a framework in cognitive science and neuroscience for describing perception, reasoning and learning of mammals. However, our understanding of how probabilistic computations could be organized in the brain, and how the observed connectivity structure of cortical microcircuits supports these calculations, is rudimentary at best. In this study, we investigate statistical inference and self-organized learning in a spatially extended spiking network model, that accommodates both local competitive and large-scale associative aspects of neural information processing, under a unified Bayesian account. Specifically, we show how the spiking dynamics of a recurrent network with lateral excitation and local inhibition in response to distributed spiking input, can be understood as sampling from a variational posterior distribution of a well-defined implicit probabilistic model. This interpretation further permits a rigorous analytical treatment of experience-dependent plasticity on the network level. Using machine learning theory, we derive update rules for neuron and synapse parameters which equate with Hebbian synaptic and homeostatic intrinsic plasticity rules in a neural implementation. In computer simulations, we demonstrate that the interplay of these plasticity rules leads to the emergence of probabilistic local experts that form distributed assemblies of similarly tuned cells communicating through lateral excitatory connections. The resulting sparse distributed spike code of a well-adapted network carries compressed information on salient input features combined with prior experience on correlations among them. Our theory predicts that the emergence of such efficient representations benefits from network architectures in which the range of local inhibition matches the spatial extent of pyramidal cells that share common afferent input.

  17. Non-local velocity distribution function and one-flight approximation

    Energy Technology Data Exchange (ETDEWEB)

    Bakunin, O.G. [FOM Instituut voor Plasmafysica ' Rijnhuizen' , Associate Euroatom-FOM, 3430 BE Nieuwegein (Netherlands) and Russian Research Center ' Kurchatov Institute' , Nuclear Fusion Institute, sq. Kurchatova 1, 123182 Moscow (Russian Federation)]. E-mail: oleg_bakunin@yahoo.com

    2004-09-13

    The functional equation describing the collisionless particle velocity distribution function f(V) is considered in the framework of probabilistic approach. The key element of the collisionless particles description is using the waiting time distribution {psi}(t). The solution of the considered functional is obtained for several model functions {psi}(t) and it leads to the power form tails of the velocity distribution f(V). It is possible to adopt considered functional to the Laplace transformation form that allows us to accord 'collision' and 'collisionless' description. This Laplace form of the functional yields the Levy-Smirnov velocity distribution function with the characteristic exponent aL=1/2.

  18. Ultrastructure of Oogenesis in Dryopteris crassirhizoma Nakai

    Institute of Scientific and Technical Information of China (English)

    Wen-Mei BAO; Qun HE; Quan-Xi WANG; Guo-Wei TIAN; Jian-Guo CAO

    2005-01-01

    The ultrastructure of oogenesis in Dryopteris crassirhizoma Nakai has been investigated using transmission electron microscopy. The nucleus in the young egg is rounded with an uneven outline. As it develops, it becomes amoeboid and extends nuclear protrusions that are not only sac-like nuclear evaginations like those often seen in the oogenesis of other ferns, but also mushroom-like and finger-like, with an opening at their end allowing the nucleolus material to flow out from the openings. This has not been observed previously. The nuclear protrusions differ from Dryopteris filix-mas (L.) Schott. in the absence of sheets of nuclear membrane in the form of a closed ring. As the egg matures, the nucleus transforms into a tuber-like structure with a smooth surface, lying transversely in the egg cell. In the immature egg, vesicles almost encircle the nucleus twice and are most remarkable. In the maturing egg, the vesicles are distributed at the periphery, except for at the top of the egg, and affect the formation of the separation cavity and extra egg membrane. Simultaneously, vesicles from the venter canal cell move to the egg and take part in the formation of separation cavity and extra egg membrane. In the mature egg, a large number of small vesicles containing fragments of lamellae or osmiophilic material emerge from the cytoplasm. The origin of these vesicles is obscure. Irregular plastids containing a cylindrical starch grain dedifferentiated progressively.Mitochondria seem to have been undeveloped during the process, but return to normal at later stages of oogenesis. There is a high frequency of ribosomes in the mature egg. Microtubules, rarely seen in the eggs ofD. filix-mas (L.) Schott. and Pteridium aquilinum (L.) Kuhn, have been observed inside the plasmalemma of the maturing egg in D. crassirhizoma.

  19. Evaluation of structural change and local strain distribution in polymers comparatively imaged by FFSA and OCT techniques

    Directory of Open Access Journals (Sweden)

    E. Leiss-Holzinger

    2012-03-01

    Full Text Available Mechanical material testing combined with optical coherence tomography (OCT allows for the first time the immediate detection of inner structural changes along with a qualitative observation of the local strain distribution in surface near bulk regions of semitransparent and translucent specimens. In addition to a 3D full field strain analysis (FFSA system based on digital image correlation (DIC, a customized spectral domain OCT system operating at 1550 nm was applied for investigation. Exemplified by tensile testing of elastomer particle filled polypropylene specimens, local dissimilarity evaluation of the OCT images was performed. The results show the high potential of OCT to provide complementary information to DIC-based FFSA, like to identify processes influencing the remaining life of advanced commodity plastics such as the start and progress of yielding, identification of the yielding point, localization of the necking front and the development of small scale voids as in the case of matrix crazing.

  20. Distribution of joint local and total size and of extension for avalanches in the Brownian force model

    Science.gov (United States)

    Delorme, Mathieu; Le Doussal, Pierre; Wiese, Kay Jörg

    2016-05-01

    The Brownian force model is a mean-field model for local velocities during avalanches in elastic interfaces of internal space dimension d , driven in a random medium. It is exactly solvable via a nonlinear differential equation. We study avalanches following a kick, i.e., a step in the driving force. We first recall the calculation of the distributions of the global size (total swept area) and of the local jump size for an arbitrary kick amplitude. We extend this calculation to the joint density of local and global sizes within a single avalanche in the limit of an infinitesimal kick. When the interface is driven by a single point, we find new exponents τ0=5 /3 and τ =7 /4 , depending on whether the force or the displacement is imposed. We show that the extension of a "single avalanche" along one internal direction (i.e., the total length in d =1 ) is finite, and we calculate its distribution following either a local or a global kick. In all cases, it exhibits a divergence P (ℓ ) ˜ℓ-3 at small ℓ . Most of our results are tested in a numerical simulation in dimension d =1 .

  1. Distribution of joint local and total size and of extension for avalanches in the Brownian force model.

    Science.gov (United States)

    Delorme, Mathieu; Le Doussal, Pierre; Wiese, Kay Jörg

    2016-05-01

    The Brownian force model is a mean-field model for local velocities during avalanches in elastic interfaces of internal space dimension d, driven in a random medium. It is exactly solvable via a nonlinear differential equation. We study avalanches following a kick, i.e., a step in the driving force. We first recall the calculation of the distributions of the global size (total swept area) and of the local jump size for an arbitrary kick amplitude. We extend this calculation to the joint density of local and global sizes within a single avalanche in the limit of an infinitesimal kick. When the interface is driven by a single point, we find new exponents τ_{0}=5/3 and τ=7/4, depending on whether the force or the displacement is imposed. We show that the extension of a "single avalanche" along one internal direction (i.e., the total length in d=1) is finite, and we calculate its distribution following either a local or a global kick. In all cases, it exhibits a divergence P(ℓ)∼ℓ^{-3} at small ℓ. Most of our results are tested in a numerical simulation in dimension d=1.

  2. Health insurance coverage, income distribution and healthcare quality in local healthcare markets.

    Science.gov (United States)

    Damianov, Damian S; Pagán, José A

    2013-08-01

    We develop a theoretical model of a local healthcare system in which consumers, health insurance companies, and healthcare providers interact with each other in markets for health insurance and healthcare services. When income and health status are heterogeneous, and healthcare quality is associated with fixed costs, the market equilibrium level of healthcare quality will be underprovided. Thus, healthcare reform provisions and proposals to cover the uninsured can be interpreted as an attempt to correct this market failure. We illustrate with a numerical example that if consumers at the local level clearly understand the linkages between health insurance coverage and the quality of local healthcare services, health insurance coverage proposals are more likely to enjoy public support.

  3. Global Optimization, Local Adaptation, and the Role of Growth in Distribution Networks

    Science.gov (United States)

    Ronellenfitsch, Henrik; Katifori, Eleni

    2016-09-01

    Highly optimized complex transport networks serve crucial functions in many man-made and natural systems such as power grids and plant or animal vasculature. Often, the relevant optimization functional is nonconvex and characterized by many local extrema. In general, finding the global, or nearly global optimum is difficult. In biological systems, it is believed that such an optimal state is slowly achieved through natural selection. However, general coarse grained models for flow networks with local positive feedback rules for the vessel conductivity typically get trapped in low efficiency, local minima. In this work we show how the growth of the underlying tissue, coupled to the dynamical equations for network development, can drive the system to a dramatically improved optimal state. This general model provides a surprisingly simple explanation for the appearance of highly optimized transport networks in biology such as leaf and animal vasculature.

  4. Global optimization, local adaptation and the role of growth in distribution networks

    CERN Document Server

    Ronellenfitsch, Henrik

    2016-01-01

    Highly-optimized complex transport networks serve crucial functions in many man-made and natural systems such as power grids and plant or animal vasculature. Often, the relevant optimization functional is non-convex and characterized by many local extrema. In general, finding the global, or nearly global optimum is difficult. In biological systems, it is believed that natural selection slowly guides the network towards an optimized state. However, general coarse grained models for flow networks with local positive feedback rules for the vessel conductivity typically get trapped in low efficiency, local minima. In this work we show how the growth of the underlying tissue, coupled to the dynamical equations for network development, can drive the system to a dramatically improved optimal state. This general model provides a surprisingly simple explanation for the appearance of highly optimized transport networks in biology such as leaf and animal vasculature.

  5. Phyllodistomum spinopapillatum sp. nov. (Digenea: Gorgoderidae), from the Oaxaca killifish Profundulus balsanus (Osteichthyes: Profundulidae) in Mexico, with new host and locality records of P. inecoli: Morphology, ultrastructure and molecular evidence.

    Science.gov (United States)

    Pérez-Ponce de León, Gerardo; Pinacho-Pinacho, Carlos D; Mendoza-Garfias, Berenit; García-Varela, Martin

    2015-06-01

    Phyllodistomum spinopapillatum sp. nov. is described from the urinary bladder of the Oaxaca killifish, Profundulus balsanus Ahl (Profundulidae) in Rio Pueblo Viejo and Rio Santa Cruz, Oaxaca, southwestern Mexico. The new species is described based on evidence gathered from morphology, scanning electron microscopy (SEM), and partial sequences of the 28S rRNA gene. Diagnostic characters of the new species of Phyllodistomum Braun 1899 are the presence of spines on the entire body surface and having a ventral sucker almost half the size of oral sucker. The new species possess a large number of dome-like papillae on the body surface with scattered distribution along the hindbody, and these papillae are characteristically spinulated. Phyllodistomum spinopapillatum sp. nov. most closely resembles P. inecoli Razo-Mendivil, Perez-Ponce de Leon and Rubio- Godoy, 2013, a parasite of the twospot livebearer Pseudoxiphophorus bimaculatus (Heckel) from Veracruz, in the Atlantic slope of Mexico. In addition to the new species, specimens of P. inecoli were also found parasitising the urinary bladder of cyprinodontiforms such as the Mexican molly Poecilia sphenops Valencienes in a pond at Santa Maria Coyotepec, and in Profundulus sp. in Rio Templo, both in Oaxaca, and in the Porthole livebearer Poeciliopsis gracilis (Heckel) in Rio San Juan, as well as in Profundulus punctatus (Gunter) from Rio Nueva Francia, both in Chiapas. The distribution and host range of P. inecoli is extended to freshwaters of the Pacific slope of Mexico, and to other cyprynodontiforms.

  6. Localized eigenmodes of the overlap operator and their impact on the eigenvalue distribution

    CERN Document Server

    Hasenfratz, Anna; Schaefer, Stefan

    2007-01-01

    In a system where chiral symmetry is spontaneously broken, the low energy eigenmodes of the continuum Dirac operator are extended. On the lattice, due to discretization effects, the Dirac operator can have localized eigenmodes that affect physical quantities sensitive to chiral symmetry. While the infrared eigenmodes of the Wilson Dirac operator are usually extended even on coarse lattices, the chiral overlap operator has many localized eigenmodes in the physical region, especially in mixed action simulations. Depending on their density, these modes can introduce strong lattice artifacts. The effect can be controlled by changing the parameters of the overlap operator, in particular the clover improvement term and the center of the overlap projection.

  7. Distribution of energy storage rate in area of strain localization during tension of austenitic steel

    Science.gov (United States)

    Oliferuk, W.; Maj, M.; Zembrzycki, K.

    2015-01-01

    The present work is devoted to experimental determination of the energy storage rate in the area of strain localization. The experimental procedure involves two complementary techniques: i.e. infrared thermography (IRT) and visible light imaging. The results of experiments have shown that during the evolution of plastic strain localization the energy storage rate in some areas of the deformed specimen drops to zero. To interpret the decrease of the energy storage rate in terms of micro-mechanisms, microstructural observations using electron back scattered diffraction (EBSC) were performed.

  8. Local Synthesis of Carbon Nanotubes in Silicon Microsystems: The Effect of Temperature Distribution on Growth Structure

    Directory of Open Access Journals (Sweden)

    Knut E. Aasmundtveit

    2013-07-01

    Full Text Available Local synthesis and direct integration of carbon nanotubes (CNTs into microsystems is a promising method for producing CNT-based devices in a single step, low-cost, and wafer-level, CMOS/MEMS-compatible process. In this report, the structure of the locally grown CNTs are studied by transmission imaging in scanning electron microscopy—S(TEM. The characterization is performed directly on the microsystem, without any post-synthesis processing required. The results show an effect of temperature on the structure of CNTs: high temperature favors thin and regular structures, whereas low temperature favors “bamboo-like” structures.

  9. Localized eigenmodes of the overlap operator and their impact on the eigenvalue distribution

    Energy Technology Data Exchange (ETDEWEB)

    Hasenfratz, A.; Hoffmann, R. [Colorado Univ., Boulder, CO (United States). Department of Physics; Schaefer, S. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC

    2007-09-15

    In a system where chiral symmetry is spontaneously broken, the low energy eigenmodes of the continuum Dirac operator are extended. On the lattice, due to discretization effects, the Dirac operator can have localized eigenmodes that affect physical quantities sensitive to chiral symmetry. While the infrared eigenmodes of the Wilson Dirac operator are usually extended even on coarse lattices, the chiral overlap operator has many localized eigenmodes in the physical region, especially in mixed action simulations. Depending on their density, these modes can introduce strong lattice artifacts. The effect can be controlled by changing the parameters of the overlap operator, in particular the clover improvement term and the center of the overlap projection. (orig.)

  10. Distributed Transmitter Localization by Power Difference of Arrival (PDOA) on a Network of GNU Radio Sensors

    Science.gov (United States)

    2015-02-03

    requiring the least hardware investment is to localize by received signal strength [1, 4, 5]. Because our intended scenario of low-complexity...MHz were taken with a spectrum analyzer program on the USRP and a range finder was used to measure the distance between the emitter and sensor

  11. Sustainability of Urban Freight Transport: Retail Distribution and Local Regulations in Cities

    NARCIS (Netherlands)

    H.J. Quak (Hans)

    2008-01-01

    textabstractAlthough our urbanized civilization requires freight transport in order to sustain it, urban freight transport is especially recognized for its unsustainable impacts. To reduce the unsustainable impacts of urban freight transport, many local governments develop policies that focus someti

  12. Experimental validation of a distributed algorithm for dynamic spectrum access in local area networks

    DEFF Research Database (Denmark)

    Tonelli, Oscar; Berardinelli, Gilberto; Tavares, Fernando Menezes Leitão;

    2013-01-01

    Next generation wireless networks aim at a significant improvement of the spectral efficiency in order to meet the dramatic increase in data service demand. In local area scenarios user-deployed base stations are expected to take place, thus making the centralized planning of frequency resources...

  13. Relation between Local Acoustic Parameters and Protein Distribution in Human and Porcine Eye Lenses

    NARCIS (Netherlands)

    Korte, de C.L.; Steen, van der A.F.W.; Thijssen, J.M.; Duindam, J.J.; Otto, Cees; Puppels, G.J.

    1994-01-01

    The purpose of this study is to characterize the eye lens (human, porcine) by acoustic measurements and to investigate whether relations exist with the local protein content. The acoustic measurements were performed with a 'scanning acoustic microscope' (SAM), operating at a frequency of 20 MHz. At

  14. Controlling gradient phase distributions in a model of active antenna array with locally coupled elements

    Science.gov (United States)

    Mishagin, K. G.; Shalfeev, V. D.

    2006-12-01

    The regime of synchronization with a certain gradient phase distribution and the possibility of controlling such distribution in a linear array of oscillators coupled by phase-locked loops (PLLs) have been theoretically studied. It is shown that a constant phase progression can be controlled by manipulating collective dynamics, with oscillator eigenfrequencies and coupling coefficients being the control parameters. The proposed principle of control, based on the nonlinear dynamics of PLL-coupled oscillators, can be used in solving the problems of phasing and controlled beam scanning in antenna arrays operating in different frequency bands.

  15. Histochemical and ultrastructural studies on the calcareous corpuscles and eggs of Taenia taeniaeformis and Dipylidium caninum.

    Science.gov (United States)

    Khalifa, Refaat M A; Mazen, Nawal A M; Marawan, Aziza M A; Thabit, Hasnaa T M

    2011-08-01

    Calcareous corpuscles were noticed by several previous workers to be present in larval and adult cestodes without knowing their function. However, nothing was mentioned in the available literature about distribution of these corpuscles and their density, structure and composition in different parts of the body of different cestodes. Hence, in the present work, a comparative study of their distribution, density, histochemical and ultrastructural characters in different parts of the body was performed in Taenia taeniaeformis and Dipylidium caninum. Due to the presence of the eggs in their gravid segments, their histochemical and ultrastructural characteristics were also studied. It was found that the size, location and density of the calcareous bodies were different in different body parts of the same and the other cestode. Histochemically, the main component of these corpuscles was calcium; while other constituents as polysaccharides, lipids, protrins and mucopolysaccharides were found in their outer rim. Ultrastructurally, they were quite similar in the two studied cestodes and different stages of their development were exhibited. Histochemically, the eggs of both cestodes were similar in their contents. However, some ultrastructural differences have been demonstrated particularly in relation to the size and shape of the rods in the embryophore and the structures in between the embryophore and onchosphere.

  16. Distribution patterns of wintering sea ducks in relation to the North Atlantic Oscillation and local environmental characteristics

    Science.gov (United States)

    Zipkin, Elise F.; Gardner, Beth; Gilbert, Andrew T.; O'Connell, Allan F.; Royle, J. Andrew; Silverman, Emily D.

    2010-01-01

    Twelve species of North American sea ducks (Tribe Mergini) winter off the eastern coast of the United States and Canada. Yet, despite their seasonal proximity to urbanized areas in this region, there is limited information on patterns of wintering sea duck habitat use. It is difficult to gather information on sea ducks because of the relative inaccessibility of their offshore locations, their high degree of mobility, and their aggregated distributions. To characterize environmental conditions that affect wintering distributions, as well as their geographic ranges, we analyzed count data on five species of sea ducks (black scoters Melanitta nigra americana, surf scoters M. perspicillata, white-winged scoters M. fusca, common eiders Somateria mollissima, and long-tailed ducks Clangula hyemalis) that were collected during the Atlantic Flyway Sea Duck Survey for ten years starting in the early 1990s. We modeled count data for each species within ten-nautical-mile linear survey segments using a zero-inflated negative binomial model that included four local-scale habitat covariates (sea surface temperature, mean bottom depth, maximum bottom slope, and a variable to indicate if the segment was in a bay or not), one broad-scale covariate (the North Atlantic Oscillation), and a temporal correlation component. Our results indicate that species distributions have strong latitudinal gradients and consistency in local habitat use. The North Atlantic Oscillation was the only environmental covariate that had a significant (but variable) effect on the expected count for all five species, suggesting that broad-scale climatic conditions may be directly or indirectly important to the distributions of wintering sea ducks. Our results provide critical information on species-habitat associations, elucidate the complicated relationship between the North Atlantic Oscillation, sea surface temperature, and local sea duck abundances, and should be useful in assessing the impacts of climate

  17. 18 CFR 284.224 - Certain transportation and sales by local distribution companies.

    Science.gov (United States)

    2010-04-01

    ...; (3) The total volume of natural gas received by the applicant from all sources during the same time... common costs allocated to the distribution function), (iv) The volume throughput of the system... not have any existing rates on file with the appropriate state regulatory agency for city-gate service...

  18. Molecular Frame X-Ray Photoelectron Angular Distributions and an Attempt to Detect Core Hole Localization

    Science.gov (United States)

    Trevisan, Cynthia; Williams, Joshua; Rescigno, Thomas; McCurdy, C.; Landers, Allen

    2013-05-01

    We present preliminary experimental and theoretical results of the angular dependence of electrons ejected from the core orbitals of ethane (C2H6) as viewed in the frame of the molecule in search for evidence of the localization of core holes on one of two equivalent atoms following X-ray photoionization. While the probability of ionization from equivalent atoms is the same, the fragmentation pattern following ionization can be asymmetric and reveal the creation of a core hole on one atom followed by breakup dynamics that depend on its location. These experiments, together with the theoretical calculations to interpret them, may result in direct observation of the fundamental quantum phenomenon of localized hole dynamics in isolated polyatomic molecules following Auger decay. Our measurements employ the COLTRIMS method and the calculations were performed with the Complex Kohn Variational method.

  19. Local administration of siRNA through Microneedle: Optimization, Bio-distribution, Tumor Suppression and Toxicity

    Science.gov (United States)

    Tang, Tao; Deng, Yan; Chen, Jiao; Zhao, Yi; Yue, Ruifeng; Choy, Kwong Wai; Wang, Chi Chiu; Du, Quan; Xu, Yan; Han, Linxiao; Chung, Tony Kwok Hung

    2016-07-01

    Although RNA interference may become a novel therapeutic approach for cancer treatment, target-site accumulation of siRNA to achieve therapeutic dosage will be a major problem. Microneedle represents a better way to deliver siRNAs and we have evaluated for the first time the capability of a silicon microneedle array for delivery of Gapdh siRNA to the skin in vivo and the results showed that the microneedle arrays could effectively deliver siRNA to relevant regions of the skin noninvasively. For the further study in this field, we evaluated the efficacy of the injectable microneedle device for local delivery of siRNA to the mouse xenograft. The results presented here indicate that local administration of siRNA through injectable microneedle could effectively deliver siRNA into the tumor region, and inhibit tumor progression without major adverse effects.

  20. Model-based Leakage Localization in Drinking Water Distribution Networks using Structured Residuals

    OpenAIRE

    Rosich, Albert; Puig, Vicenç

    2013-01-01

    In this paper, a new model based approach to leakage localization in drinking water networks is proposed based on generating a set of structured residuals. The residual evaluation is based on a numerical method based on an enhanced Newton-Raphson algorithm. The proposed method is suitable for water network systems because the non-linearities of the model make impossible to derive analytical residuals. Furthermore, the computed residuals are designed so that leaks are decoupled, which impro...

  1. Effects of axotomy on the expression and ultrastructural localization of N-cadherin and neural cell adhesion molecule in the quail ciliary ganglion: an in vivo model of neuroplasticity.

    Science.gov (United States)

    Squitti, R; De Stefano, M E; Edgar, D; Toschi, G

    1999-01-01

    Postganglionic nerve crush of the avian ciliary ganglion induces detachment of preganglionic terminals from the soma of the injured ciliary neurons, followed by reattachment at about the same time that the postganglionic axons regenerate to their targets. In order to determine the role played by cell adhesion molecules in this response, we have studied injury-induced changes in the amount and distribution of N-cadherin and neural cell adhesion molecule, together with modifications in the expression of their messenger RNAs. Both N-cadherin and neural cell adhesion molecule immunoreactivities associated with postsynaptic specializations decreased between one and three days following postganglionic nerve crush, preceding the detachment of the preganglionic boutons. Immunoreactivities subsequently increased between 13 and 20 days, in parallel with restoration of synaptic contacts on the ganglion cells and the progressive reinnervation of the peripheral targets. In contrast to the rapid decrease in immunoreactivity, the messenger RNA levels of N-cadherin and neural cell adhesion molecule both increased after crush, and remained elevated throughout the 20-day period of the experiment. These results are consistent with roles for N-cadherin and neural cell adhesion molecule in the maintenance of synaptic contacts. The rapid regulation of these proteins in injury-induced synaptic plasticity occurs at the post-transcriptional level, whereas longer term regulation associated with the re-establishment of synapses may be promoted by the increased levels of gene expression.

  2. A Distributed Method to Localization for Mobile Sensor Networks based on the convex hull

    Directory of Open Access Journals (Sweden)

    Yassine SABRI,

    2012-10-01

    Full Text Available There has been recently a trend of exploiting the heterogeneity in WSNs and the mobility of either the sensor nodes or the sink nodes to facilitate data dissemination in WSNs. Recently, there has been much focus on mobile sensor networks, and we have even seen the development of small-profile sensing devices that are able to control their own movement. Although it has been shown that mobility alleviates several issues relating to sensor network coverage and connectivity, many challenges remain. Among these, the need for position estimation is perhaps the most important. Not only is localization required to understand sensor data in a spatial context, but also for navigation, a key feature of mobile sensors. This paper concerns the localization problem in the case where all nodes in the network (anchors and others sensors are mobile. We propose the technique following the capabilities of nodes. Thus, each node obtains either an exact position or an approximate position with the knowledge of the maximal error born. Also, we adapt the periods where nodes invoke their localization. Simulation results show the performances of our method in term of accuracy and determinate the technique the more adapted related to the network configurations.

  3. Distributed RSS-Based Localization in Wireless Sensor Networks Based on Second-Order Cone Programming

    Science.gov (United States)

    Tomic, Slavisa; Beko, Marko; Dinis, Rui

    2014-01-01

    In this paper, we propose a new approach based on convex optimization to address the received signal strength (RSS)-based cooperative localization problem in wireless sensor networks (WSNs). By using iterative procedures and measurements between two adjacent nodes in the network exclusively, each target node determines its own position locally. The localization problem is formulated using the maximum likelihood (ML) criterion, since ML-based solutions have the property of being asymptotically efficient. To overcome the non-convexity of the ML optimization problem, we employ the appropriate convex relaxation technique leading to second-order cone programming (SOCP). Additionally, a simple heuristic approach for improving the convergence of the proposed scheme for the case when the transmit power is known is introduced. Furthermore, we provide details about the computational complexity and energy consumption of the considered approaches. Our simulation results show that the proposed approach outperforms the existing ones in terms of the estimation accuracy for more than 1.5 m. Moreover, the new approach requires a lower number of iterations to converge, and consequently, it is likely to preserve energy in all presented scenarios, in comparison to the state-of-the-art approaches. PMID:25275350

  4. Distributed RSS-Based Localization in Wireless Sensor Networks Based on Second-Order Cone Programming

    Directory of Open Access Journals (Sweden)

    Slavisa Tomic

    2014-10-01

    Full Text Available In this paper, we propose a new approach based on convex optimization to address the received signal strength (RSS-based cooperative localization problem in wireless sensor networks (WSNs. By using iterative procedures and measurements between two adjacent nodes in the network exclusively, each target node determines its own position locally. The localization problem is formulated using the maximum likelihood (ML criterion, since ML-based solutions have the property of being asymptotically efficient. To overcome the non-convexity of the ML optimization problem, we employ the appropriate convex relaxation technique leading to second-order cone programming (SOCP. Additionally, a simple heuristic approach for improving the convergence of the proposed scheme for the case when the transmit power is known is introduced. Furthermore, we provide details about the computational complexity and energy consumption of the considered approaches. Our simulation results show that the proposed approach outperforms the existing ones in terms of the estimation accuracy for more than 1:5 m. Moreover, the new approach requires a lower number of iterations to converge, and consequently, it is likely to preserve energy in all presented scenarios, in comparison to the state-of-the-art approaches.

  5. African and local wind-blown dist contributions at three rural sites in SE Spain: the aerosol size distribution

    Energy Technology Data Exchange (ETDEWEB)

    Orza, J. A. G.; Cabello, M.; Lidon, V.; Martinez, J.

    2009-07-01

    The entrainment of particulate material into the atmosphere by wind action on surface soils both disturbed and natural, as well as directly due to human activities like agricultural practices, mineral industry operations, construction works and traffic, is a significant contribution to the aerosol load in Mediterranean semi-arid areas. A further crustal contribution in the region comes from the frequent arrival of African mineral dust plumes. We summarize some of the results obtained after 4-6 month campaigns at three rural sites in SE Spain where the aerosol number size distribution (31 size bins between 0.25 and 32 {mu}m) was continuously measured. The influence of both local wind speed and the arrival of air masses loaded with African dust on the airborne particulate distribution is assessed. Similarities and differences between the three locations give information that allows a better understanding of the influence of both local wind speed and African dust outbreaks (ADO), while highlight what is mostly related to local features. (Author)

  6. Ultrastructure of the ganglion on human internal laryngeal nerve.

    Science.gov (United States)

    Ramaswamy, S; Shankar, S K; Manjunath, K Y; Devanathan, P H; Nityaseelan, N

    1994-01-01

    There is now definite evidence for the presence of a macroscopic ganglion on the human internal laryngeal nerve, with the distribution of its post-ganglionic fibres to the glands in the saccule and to the glands at the root of epiglottis in the vicinity of the opening of the saccule. This ganglion could be identified as early as 14 weeks in human foetal larynx, which contains immature neurons. Seven ganglia, dissected from human laryngectomy specimens and resected for carcinoma larynx, were studied by electron microscopy. Ultrastructurally, the neurons and the synaptic terminals had both small, round, luscent vesicles and dense core vesicles. Symmetrical, asymmetrical and electrical synaptic complexes were noted. A few neurons revealed degenerative changes suggestive of axotomy. The location of the ganglion on the internal laryngeal nerve, a branch of nervus vagus, and ultrastructural demonstration of large and small dense core vesicles and small luscent vesicles in the neurons of this ganglion, lead us to believe that the ganglion is parasympathetic in nature.

  7. Visualising the strain distribution in suspended two-dimensional materials under local deformation

    Science.gov (United States)

    Elibol, Kenan; Bayer, Bernhard C.; Hummel, Stefan; Kotakoski, Jani; Argentero, Giacomo; Meyer, Jannik C.

    2016-06-01

    We demonstrate the use of combined simultaneous atomic force microscopy (AFM) and laterally resolved Raman spectroscopy to study the strain distribution around highly localised deformations in suspended two-dimensional materials. Using the AFM tip as a nanoindentation probe, we induce localised strain in suspended few-layer graphene, which we adopt as a two-dimensional membrane model system. Concurrently, we visualise the strain distribution under and around the AFM tip in situ using hyperspectral Raman mapping via the strain-dependent frequency shifts of the few-layer graphene’s G and 2D Raman bands. Thereby we show how the contact of the nm-sized scanning probe tip results in a two-dimensional strain field with μm dimensions in the suspended membrane. Our combined AFM/Raman approach thus adds to the critically required instrumental toolbox towards nanoscale strain engineering of two-dimensional materials.

  8. Local distribution of wall static pressure and heat transfer on a smooth flat plate impinged by a slot air jet

    Science.gov (United States)

    Adimurthy, M.; Katti, Vadiraj V.

    2016-06-01

    Local distribution of wall static pressure and heat transfer on a smooth flat plate impinged by a normal slot air jet is experimental investigated. Present study focuses on the influence of jet-to-plate spacing (Z/D h ) (0.5-10) and Reynolds number (2500-20,000) on the fluid flow and heat transfer distribution. A single slot jet with an aspect ratio (l/b) of about 22 is chosen for the current study. Infrared Thermal Imaging technique is used to capture the temperature data on the target surface. Local heat transfer coefficients are estimated from the thermal images using `SMART VIEW' software. Wall static pressure measurement is carried out for the specified range of Re and Z/D h . Wall static pressure coefficients are seen to be independent of Re in the range between 5000 and 15,000 for a given Z/D h . Nu values are higher at the stagnation point for all Z/D h and Re investigated. For lower Z/D h and higher Re, secondary peaks are observed in the heat transfer distributions. This may be attributed to fluid translating from laminar to turbulent flow on the target plate. Heat transfer characteristics are explained based on the simplified flow assumptions and the pressure data obtained using Differential pressure transducer and static pressure probe. Semi-empirical correlation for the Nusselt number in the stagnation region is proposed.

  9. Local distribution of wall static pressure and heat transfer on a smooth flat plate impinged by a slot air jet

    Science.gov (United States)

    M, Adimurthy; Katti, Vadiraj V.

    2017-02-01

    Local distribution of wall static pressure and heat transfer on a smooth flat plate impinged by a normal slot air jet is experimental investigated. Present study focuses on the influence of jet-to-plate spacing ( Z/D h ) (0.5-10) and Reynolds number (2500-20,000) on the fluid flow and heat transfer distribution. A single slot jet with an aspect ratio ( l/b) of about 22 is chosen for the current study. Infrared Thermal Imaging technique is used to capture the temperature data on the target surface. Local heat transfer coefficients are estimated from the thermal images using `SMART VIEW' software. Wall static pressure measurement is carried out for the specified range of Re and Z/D h . Wall static pressure coefficients are seen to be independent of Re in the range between 5000 and 15,000 for a given Z/D h . Nu values are higher at the stagnation point for all Z/D h and Re investigated. For lower Z/D h and higher Re, secondary peaks are observed in the heat transfer distributions. This may be attributed to fluid translating from laminar to turbulent flow on the target plate. Heat transfer characteristics are explained based on the simplified flow assumptions and the pressure data obtained using Differential pressure transducer and static pressure probe. Semi-empirical correlation for the Nusselt number in the stagnation region is proposed.

  10. The Local Lyman-$\\alpha$ Forest; 1, Distribution of HI Absorbers, Doppler Widths, and Baryon Content

    CERN Document Server

    Penton, S V; Stocke, J T; Penton, Steven V.; Stocke, John T.

    1999-01-01

    In Paper I of this series (astro-ph/9911117) we described observations of 15 extragalactic targets taken with the Hubble Space Telescope GHRS/G160M grating for studies of the low-z Lya forest. We reported the detection of 110 Lya absorbers at significance level >3 sigma in the redshift range z=0.002-0.069, over a total pathlength of 116,000 km/s. In this second paper, we evaluate the physical properties of these Lya absorbers and compare them to their high-z counterparts. The distribution of Doppler parameters is similar to that at high redshift, with mean b = 35.0 +- 16.6 km/s. The true Doppler parameter may be somewhat lower, owing to component blends and non-thermal velocities. The distribution of equivalent widths exhibits a significant break at W~133mA, with an increasing number of weak absorbers (10mA-100mA). Adopting a curve of growth with b = 25 +- 5km/s and applying a sensitivity correction as a function of equivalent width and wavelength, we derive the distribution in column density, Nh^{-1.80+-0.05...

  11. Ultrastructure of sporulation in Haplosporidium armoricanum

    NARCIS (Netherlands)

    Hine, P.M.; Engelsma, M.Y.; Wakefield, S.J.

    2007-01-01

    An ultrastructural study was carried out on the tissues of an oyster (Ostrea edulis), heavily infected with Haplosporidium armoricanum (van Banning, 1977), that had been fixed in Carson¿s fixative. The well-fixed tissues revealed details of sporulation and of the spores, which had not been previousl

  12. Ultrastructural differences between diabetic and idiopathic gastroparesis

    NARCIS (Netherlands)

    Faussone-Pellegrini, Maria Simonetta; Grover, Madhusudan; Pasricha, Pankaj J.; Bernard, Cheryl E.; Lurken, Matthew S.; Smyrk, Thomas C.; Parkman, Henry P.; Abell, Thomas L.; Snape, William J.; Hasler, William L.; Uenalp-Arida, Aynur; Nguyen, Linda; Koch, Kenneth L.; Calles, Jorges; Lee, Linda; Tonascia, James; Hamilton, Frank A.; Farrugia, Gianrico

    2012-01-01

    The ultrastructural changes in diabetic and idiopathic gastroparesis are not well studied and it is not known whether there are different defects in the two disorders. As part of the Gastroparesis Clinical Research Consortium, full thickness gastric body biopsies from 20 diabetic and 20 idiopathic g

  13. Ultrastructure of sporulation in Haplosporidium armoricanum

    NARCIS (Netherlands)

    Hine, P.M.; Engelsma, M.Y.; Wakefield, S.J.

    2007-01-01

    An ultrastructural study was carried out on the tissues of an oyster (Ostrea edulis), heavily infected with Haplosporidium armoricanum (van Banning, 1977), that had been fixed in Carson¿s fixative. The well-fixed tissues revealed details of sporulation and of the spores, which had not been

  14. INTEGRATED MANAGEMENT SYSTEMS IN LOCAL PUBLIC ENTERPRIZE FOR PRODUCTION, DISTRIBUTION AND CLEANING OF WASTED WATER

    Directory of Open Access Journals (Sweden)

    Slavko Arsovski

    2007-06-01

    Full Text Available Appearance of large number of management systems, with different and sometimes divergent demands, needs reconsideration of their implementation strategies and their integration in one integrated management system (IMS. So defined IMS would be designed and implemented in different areas. In this paper is presented basic concept of integration of partical management systems in areas of quality (ISO 9001, environmental protection (ISO 14001, occupational health (ISO 18001, food safety (ISO 22000 and accreditation of laboratories (ISO17025/ISO17020. As a pilot organization is choosed local public enterprise for production, supply and drain of water.

  15. Ubiquitous distribution and different subcellular localization of sorbitol dehydrogenase in fruit and leaf of apple

    OpenAIRE

    2009-01-01

    NAD+-dependent sorbitol dehydrogenase (NAD-SDH, EC 1.1.1.14), a key enzyme in sorbitol metabolism, plays an important role in regulating sink strength and determining the quality of apple fruit. Understanding the tissue and subcellular localization of NAD-SDH is helpful for understanding sorbitol metabolism in the apple. In this study, two NAD-SDH cDNA sequences were isolated from apple fruits (Malus domestica Borkh cv. Starkrimson) and named MdSDH5 and MdSDH6. Immunohistochemical analysis re...

  16. Relativistic electron's butterfly pitch angle distribution modulated by localized background magnetic field perturbation driven by hot ring current ions

    Science.gov (United States)

    Xiong, Ying; Chen, Lunjin; Xie, Lun; Fu, Suiyan; Xia, Zhiyang; Pu, Zuyin

    2017-05-01

    Dayside modulated relativistic electron's butterfly pitch angle distributions (PADs) from ˜200 keV to 2.6 MeV were observed by Van Allen Probe B at L = 5.3 on 15 November 2013. They were associated with localized magnetic dip driven by hot ring current ion (60-100 keV proton and 60-200 keV helium and oxygen) injections. We reproduce the electron's butterfly PADs at satellite's location using test particle simulation. The simulation results illustrate that a negative radial flux gradient contributes primarily to the formation of the modulated electron's butterfly PADs through inward transport due to the inductive electric field, while deceleration due to the inductive electric field and pitch angle change also makes in part contribution. We suggest that localized magnetic field perturbation, which is a frequent phenomenon in the magnetosphere during magnetic disturbances, is of great importance for creating electron's butterfly PADs in the Earth's radiation belts.

  17. Single molecule localization microscopy of the distribution of chromatin using Hoechst and DAPI fluorescent probes.

    Science.gov (United States)

    Szczurek, Aleksander T; Prakash, Kirti; Lee, Hyun-Keun; Zurek-Biesiada, Dominika J; Best, Gerrit; Hagmann, Martin; Dobrucki, Jurek W; Cremer, Christoph; Birk, Udo

    2014-01-01

    Several approaches have been described to fluorescently label and image DNA and chromatin in situ on the single-molecule level. These superresolution microscopy techniques are based on detecting optically isolated, fluorescently tagged anti-histone antibodies, fluorescently labeled DNA precursor analogs, or fluorescent dyes bound to DNA. Presently they suffer from various drawbacks such as low labeling efficiency or interference with DNA structure. In this report, we demonstrate that DNA minor groove binding dyes, such as Hoechst 33258, Hoechst 33342, and DAPI, can be effectively employed in single molecule localization microscopy (SMLM) with high optical and structural resolution. Upon illumination with low intensity 405 nm light, a small subpopulation of these molecules stochastically undergoes photoconversion from the original blue-emitting form to a green-emitting form. Using a 491 nm laser excitation, fluorescence of these green-emitting, optically isolated molecules was registered until "bleached". This procedure facilitated substantially the optical isolation and localization of large numbers of individual dye molecules bound to DNA in situ, in nuclei of fixed mammalian cells, or in mitotic chromosomes, and enabled the reconstruction of high-quality DNA density maps. We anticipate that this approach will provide new insights into DNA replication, DNA repair, gene transcription, and other nuclear processes.

  18. Distributed, signal strength-based indoor localization algorithm for use in healthcare environments.

    Science.gov (United States)

    Wyffels, Jeroen; De Brabanter, Jos; Crombez, Pieter; Verhoeve, Piet; Nauwelaers, Bart; De Strycker, Lieven

    2014-11-01

    In current healthcare environments, a trend toward mobile and personalized interactions between people and nurse call systems is strongly noticeable. Therefore, it should be possible to locate patients at all times and in all places throughout the care facility. This paper aims at describing a method by which a mobile node can locate itself indoors, based on signal strength measurements and a minimal amount of yes/no decisions. The algorithm has been developed specifically for use in a healthcare environment. With extensive testing and statistical support, we prove that our algorithm can be used in a healthcare setting with an envisioned level of localization accuracy up to room revel (or region level in a corridor), while avoiding heavy investments since the hardware of an existing nurse call network can be reused. The approach opted for leads to very high scalability, since thousands of mobile nodes can locate themselves. Network timing issues and localization update delays are avoided, which ensures that a patient can receive the needed care in a time and resources efficient way.

  19. Single molecule localization microscopy of the distribution of chromatin using Hoechst and DAPI fluorescent probes

    Science.gov (United States)

    Szczurek, Aleksander T; Prakash, Kirti; Lee, Hyun-Keun; Żurek-Biesiada, Dominika J; Best, Gerrit; Hagmann, Martin; Dobrucki, Jurek W; Cremer, Christoph; Birk, Udo

    2014-01-01

    Several approaches have been described to fluorescently label and image DNA and chromatin in situ on the single-molecule level. These superresolution microscopy techniques are based on detecting optically isolated, fluorescently tagged anti-histone antibodies, fluorescently labeled DNA precursor analogs, or fluorescent dyes bound to DNA. Presently they suffer from various drawbacks such as low labeling efficiency or interference with DNA structure. In this report, we demonstrate that DNA minor groove binding dyes, such as Hoechst 33258, Hoechst 33342, and DAPI, can be effectively employed in single molecule localization microscopy (SMLM) with high optical and structural resolution. Upon illumination with low intensity 405 nm light, a small subpopulation of these molecules stochastically undergoes photoconversion from the original blue-emitting form to a green-emitting form. Using a 491 nm laser excitation, fluorescence of these green-emitting, optically isolated molecules was registered until “bleached”. This procedure facilitated substantially the optical isolation and localization of large numbers of individual dye molecules bound to DNA in situ, in nuclei of fixed mammalian cells, or in mitotic chromosomes, and enabled the reconstruction of high-quality DNA density maps. We anticipate that this approach will provide new insights into DNA replication, DNA repair, gene transcription, and other nuclear processes. PMID:25482122

  20. Tissue distribution, intracellular localization and proteolytic processing of rat 4-hydroxyphenylpyruvate dioxygenase.

    Science.gov (United States)

    Neve, Søren; Aarenstrup, Lene; Tornehave, Ditte; Rahbek-Nielsen, Henrik; Corydon, Thomas Juhl; Roepstorff, Peter; Kristiansen, Karsten

    2003-01-01

    4-hydroxyphenylpyruvate dioxygenase (HPD) is an important enzyme involved in tyrosine catabolism. HPD was shown to be identical to a protein named the F-antigen, exploited by immunologists because of its unique immunological properties. Congenital HPD deficiency is a rare, relatively benign condition known as hereditary type III tyrosinemia. Decreased expression of HPD is often observed in association with the severe type I tyrosinemia, and interestingly, inhibition of HPD activity seems to ameliorate the clinical symptoms of type I tyrosinemia. In this study we present a comprehensive analysis of tissue specific expression and intracellular localization of HPD in the rat. By combined use of in situ hybridization and immunohistochemistry we confirm previously known sites of expression in liver and kidney. In addition, we show that HPD is abundantly expressed in neurons in the cortex, cerebellum and hippocampus. By using immunoelectron microscopy and confocal laser scanning microscopy, we provide evidence that HPD contrary to earlier assumptions specifically localizes to membranes of the endoplasmic reticulum and the Golgi apparatus. Detailed mass spectrometric analyses of HPD purified from rat liver revealed N-terminal and C-terminal processing of HPD, and expression of recombinant HPD suggested that C-terminal processing enhances the enzymatic activity.

  1. The Localized Discovery and Recovery for Query Packet Losses in Wireless Sensor Networks with Distributed Detector Clusters

    Directory of Open Access Journals (Sweden)

    Ryu Miura

    2013-06-01

    Full Text Available An essential application of wireless sensor networks is to successfully respond to user queries. Query packet losses occur in the query dissemination due to wireless communication problems such as interference, multipath fading, packet collisions, etc. The losses of query messages at sensor nodes result in the failure of sensor nodes reporting the requested data. Hence, the reliable and successful dissemination of query messages to sensor nodes is a non-trivial problem. The target of this paper is to enable highly successful query delivery to sensor nodes by localized and energy-efficient discovery, and recovery of query losses. We adopt local and collective cooperation among sensor nodes to increase the success rate of distributed discoveries and recoveries. To enable the scalability in the operations of discoveries and recoveries, we employ a distributed name resolution mechanism at each sensor node to allow sensor nodes to self-detect the correlated queries and query losses, and then efficiently locally respond to the query losses. We prove that the collective discovery of query losses has a high impact on the success of query dissemination and reveal that scalability can be achieved by using the proposed approach. We further study the novel features of the cooperation and competition in the collective recovery at PHY and MAC layers, and show that the appropriate number of detectors can achieve optimal successful recovery rate. We evaluate the proposed approach with both mathematical analyses and computer simulations. The proposed approach enables a high rate of successful delivery of query messages and it results in short route lengths to recover from query losses. The proposed approach is scalable and operates in a fully distributed manner.

  2. Abiotic and biotic controls on local spatial distribution and performance of Boechera stricta

    Directory of Open Access Journals (Sweden)

    KUSUM J NAITHANI

    2014-07-01

    Full Text Available This study investigates the relative influence of biotic and abiotic factors on community dynamics using an integrated approach and highlights the influence of space on genotypic and phenotypic traits in plant community structure. We examined the relative influence of topography, environment, spatial distance, and intra- and interspecific interactions on spatial distribution and performance of Boechera stricta (rockcress, a close perennial relative of model plant Arabidopsis. First, using Bayesian kriging, we mapped the topography and environmental gradients and explored the spatial distribution of naturally occurring rockcress plants and two neighbors, Taraxacum officinale (dandelion and Solidago missouriensis (goldenrod found in close proximity within a typical diverse meadow community across topographic and environmental gradients. We then evaluated direct and indirect relationships among variables using Mantel path analysis and developed a network displaying abiotic and biotic interactions in this community. We found significant spatial autocorrelation among rockcress individuals, either because of common microhabitats as displayed by high density of individuals at lower elevation and high soil moisture area, or limited dispersal as shown by significant spatial autocorrelation of naturally occurring inbred lines, or a combination of both. Goldenrod and dandelion density around rockcress does not show any direct relationship with rockcress fecundity, possibly due to spatial segregation of resources. However, dandelion density around rockcress shows an indirect negative influence on rockcress fecundity via herbivory, indicating interspecific competition. Overall, we suggest that common microhabitat preference and limited dispersal are the main drivers for spatial distribution. However, intra-specific interactions and insect herbivory are the main drivers of rockcress performance in the meadow community.

  3. Wearable Sensor Localization Considering Mixed Distributed Sources in Health Monitoring Systems.

    Science.gov (United States)

    Wan, Liangtian; Han, Guangjie; Wang, Hao; Shu, Lei; Feng, Nanxing; Peng, Bao

    2016-03-12

    In health monitoring systems, the base station (BS) and the wearable sensors communicate with each other to construct a virtual multiple input and multiple output (VMIMO) system. In real applications, the signal that the BS received is a distributed source because of the scattering, reflection, diffraction and refraction in the propagation path. In this paper, a 2D direction-of-arrival (DOA) estimation algorithm for incoherently-distributed (ID) and coherently-distributed (CD) sources is proposed based on multiple VMIMO systems. ID and CD sources are separated through the second-order blind identification (SOBI) algorithm. The traditional estimating signal parameters via the rotational invariance technique (ESPRIT)-based algorithm is valid only for one-dimensional (1D) DOA estimation for the ID source. By constructing the signal subspace, two rotational invariant relationships are constructed. Then, we extend the ESPRIT to estimate 2D DOAs for ID sources. For DOA estimation of CD sources, two rational invariance relationships are constructed based on the application of generalized steering vectors (GSVs). Then, the ESPRIT-based algorithm is used for estimating the eigenvalues of two rational invariance matrices, which contain the angular parameters. The expressions of azimuth and elevation for ID and CD sources have closed forms, which means that the spectrum peak searching is avoided. Therefore, compared to the traditional 2D DOA estimation algorithms, the proposed algorithm imposes significantly low computational complexity. The intersecting point of two rays, which come from two different directions measured by two uniform rectangle arrays (URA), can be regarded as the location of the biosensor (wearable sensor). Three BSs adopting the smart antenna (SA) technique cooperate with each other to locate the wearable sensors using the angulation positioning method. Simulation results demonstrate the effectiveness of the proposed algorithm.

  4. Wearable Sensor Localization Considering Mixed Distributed Sources in Health Monitoring Systems

    Directory of Open Access Journals (Sweden)

    Liangtian Wan

    2016-03-01

    Full Text Available In health monitoring systems, the base station (BS and the wearable sensors communicate with each other to construct a virtual multiple input and multiple output (VMIMO system. In real applications, the signal that the BS received is a distributed source because of the scattering, reflection, diffraction and refraction in the propagation path. In this paper, a 2D direction-of-arrival (DOA estimation algorithm for incoherently-distributed (ID and coherently-distributed (CD sources is proposed based on multiple VMIMO systems. ID and CD sources are separated through the second-order blind identification (SOBI algorithm. The traditional estimating signal parameters via the rotational invariance technique (ESPRIT-based algorithm is valid only for one-dimensional (1D DOA estimation for the ID source. By constructing the signal subspace, two rotational invariant relationships are constructed. Then, we extend the ESPRIT to estimate 2D DOAs for ID sources. For DOA estimation of CD sources, two rational invariance relationships are constructed based on the application of generalized steering vectors (GSVs. Then, the ESPRIT-based algorithm is used for estimating the eigenvalues of two rational invariance matrices, which contain the angular parameters. The expressions of azimuth and elevation for ID and CD sources have closed forms, which means that the spectrum peak searching is avoided. Therefore, compared to the traditional 2D DOA estimation algorithms, the proposed algorithm imposes significantly low computational complexity. The intersecting point of two rays, which come from two different directions measured by two uniform rectangle arrays (URA, can be regarded as the location of the biosensor (wearable sensor. Three BSs adopting the smart antenna (SA technique cooperate with each other to locate the wearable sensors using the angulation positioning method. Simulation results demonstrate the effectiveness of the proposed algorithm.

  5. Stationary and uniform entanglement distribution in qubit networks with quasi-local dissipation

    CERN Document Server

    Rafiee, Morteza; Mokhtari, Hossein; Mancini, Stefano

    2012-01-01

    We consider qubit networks where adjacent qubits besides interacting via XY-coupling, also dissipate into the same environment. The steady states are computed exactly for all network sizes and topologies, showing that they are always symmetric under permutation of network sites, leading to a uniform distribution of the stationary entanglement across the network. The maximum entanglement between two arbitrary qubits is shown to depend only on the total number of qubits in the network, and scales linearly with it. A possible physical realization by means of an array of doped cavities is discussed for the case of a linear chain.

  6. Unambiguous observation of F-atom core-hole localization in CF4 through body-frame photoelectron angular distributions

    Science.gov (United States)

    McCurdy, C. W.; Rescigno, T. N.; Trevisan, C. S.; Lucchese, R. R.; Gaire, B.; Menssen, A.; Schöffler, M. S.; Gatton, A.; Neff, J.; Stammer, P. M.; Rist, J.; Eckart, S.; Berry, B.; Severt, T.; Sartor, J.; Moradmand, A.; Jahnke, T.; Landers, A. L.; Williams, J. B.; Ben-Itzhak, I.; Dörner, R.; Belkacem, A.; Weber, Th.

    2017-01-01

    A dramatic symmetry breaking in K -shell photoionization of the CF4 molecule in which a core-hole vacancy is created in one of four equivalent fluorine atoms is displayed in the molecular frame angular distribution of the photoelectrons. Observing the photoejected electron in coincidence with an F+ atomic ion after Auger decay is shown to select the dissociation path where the core hole was localized almost exclusively on that atom. A combination of measurements and ab initio calculations of the photoelectron angular distribution in the frame of the recoiling CF3+ and F+ atoms elucidates the underlying physics that derives from the Ne-like valence structure of the F(1 s-1 ) core-excited atom.

  7. Immunocytochemical localization of sodium channel distributions in the excitable membranes of Electrophorus electricus.

    Science.gov (United States)

    Ellisman, M H; Levinson, S R

    1982-01-01

    The tetrodotoxin binding protein, a major component of the Na+ channel, has been purified from the electric organ of the South American eel Electrophorus electricus. Antibodies to this protein were raised in rabbits and their specificity was demonstrated by a highly sensitive radioimmunoassay and by immunoprecipitation procedures. These antibodies were used to examine the distribution of the binding protein in the eel electroplax membranes and along myelinated nerve axons. The distribution of the antigen was determined by using the peroxidase-antiperoxidase technique at both the light and electron microscopic levels. In the electrocytes of the electric organ, only the innervated face showed staining in experimental material. The stained regions of electroplax plasmalemma included the caveolae of the innervated surface while caveolae of the non-innervated surface did not stain. Thus, the innervated surface including caveolae exclusively contains the Na+ channels. Along myelinated axons, staining was limited to the nodal zone of the node of Ranvier. The paranodal and internodal zones did not stain for the binding protein. Limited diffusion of primary IgG and subsequent reactants into the paranodal and internodal sites was eliminated as a possible source of focal staining at nodes because mechanically demyelinated preparations also exhibited focal nodal staining. Thus, this tetrodotoxin binding protein component of the Na+ channel is located solely within the nodal zone of the node of Ranvier. Images PMID:6292913

  8. Optimization of the Distribution and Localization of Wireless Sensor Networks Based on Differential Evolution Approach

    Directory of Open Access Journals (Sweden)

    Armando Céspedes-Mota

    2016-01-01

    Full Text Available Location information for wireless sensor nodes is needed in most of the routing protocols for distributed sensor networks to determine the distance between two particular nodes in order to estimate the energy consumption. Differential evolution obtains a suboptimal solution based on three features included in the objective function: area, energy, and redundancy. The use of obstacles is considered to check how these barriers affect the behavior of the whole solution. The obstacles are considered like new restrictions aside of the typical restrictions of area boundaries and the overlap minimization. At each generation, the best element is tested to check whether the node distribution is able to create a minimum spanning tree and then to arrange the nodes using the smallest distance from the initial position to the suboptimal end position based on the Hungarian algorithm. This work presents results for different scenarios delimited by walls and testing whether it is possible to obtain a suboptimal solution with inner obstacles. Also, a case with an area delimited by a star shape is presented showing that the algorithm is able to fill the whole area, even if such area is delimited for the peaks of the star.

  9. The Stellar Number Density Distribution in the Local Solar Neighborhood is North-South Asymmetric

    Energy Technology Data Exchange (ETDEWEB)

    Yanny, Brian [Fermilab; Gardner, Susan [Kentucky U.

    2013-10-17

    We study the number density distribution of a sample of K and M dwarf stars, matched North and South of the Galactic plane within a distance of 2 kpc from the sun, using observations from the Ninth Data Release of the Sloan Digital Sky Survey. We determine distances using the photometric parallax method, and in this context systematic effects exist which could potentially impact the determination of the number density profile with height from the Galactic plane --- and ultimately affect a number density North-South asymmetry. They include: (i) the calibration of the various photometric parallax relations, (ii) the ability to separate dwarfs from giants in our sample, (iii) the role of stellar population differences such as age and metallicity, (iv) the ability to determine the offset of the sun from the Galactic plane, and (v) the correction for reddening from dust in the Galactic plane, though our stars are at high Galactic latitudes. We find the various analyzed systematic effects to have a negligible impact on our observed asymmetry, and using a new and larger sample of stars we confirm and refine the earlier discovery of Widrow et al. of a significant Galactic North-South asymmetry in the stellar number density distribution.

  10. An Auction-Bidding Protocol for Distributed Bit Allocation in RSSI-based Localization Networks

    Directory of Open Access Journals (Sweden)

    Ahmad A. Ababneh

    2016-06-01

    Full Text Available Several factors (e.g., target energy, sensor density affect estimation error at a point of interest in sensor networks. One of these factors is the number of allocated bits to sensors that cover the point of interest when quantization is employed. In this paper, we investigate bit allocation in such networks such that estimation error requirements at multiple points of interest are satisfied as best as possible. To solve this nonlinear integer programming problem, we propose an iterative distributed auctionbidding protocol. Starting with some initial bit distribution, a network is divided into a a number of clusters each with its own auction. Each cluster head (CH acts as an auctioneer and divides sensors into buyers or sellers of bits (i.e., commodity. With limited messaging, CHs redistribute bits among sensors, each bit at a time such that the difference between achieved and required estimation errors within each cluster is reduced in each round. We propose two bit-pricing schemes used by sensors to decide on exchanging bits. Finally, simulation results show that our proposed ‘distributed’ protocol’s error performance can be within 5%-10% of that of a ‘centralized’ genetic algorithm (GA solution.

  11. Electron distribution function behavior during localized transverse ion acceleration events in the topside auroral zone

    Energy Technology Data Exchange (ETDEWEB)

    Lynch, K.A.; Arnoldy, R.L. [Univ. of New Hampshire, Durham, NH (United States); Kintner, P.M. [Cornell Univ., Ithaca, NY (United States); Vago, J.L. [European Space Agency, Noordwijk (Netherlands)

    1994-02-01

    The Topaz3 auroral sounding rocket made the following observations concerning the transfer of precipitating auroral electron energy to transverse ion acceleration in the topside auroral zone. During the course of the flight, the precipitating electron beam was modified to varying degrees by interaction with VLF hiss, at times changing the beam into a field-aligned plateau. The electron distribution functions throughout the flight are classified according to the extent of this modification, and correspondences with ion acceleration events are sought. The hiss power during most of this rocket flight apparently exceeded the threshold for collapse into solitary structures. At the times of plateaued electron distributions, the collapse of these structures was limited by Landau damping through the ambient ions, resulting in a velocity-dependent acceleration of both protons and oxygen. This initial acceleration is sufficient to supply the number flux of upflowing ions observed at satellite altitudes. The bursty ion acceleration was anticorrelated, on 1-s or smaller timescales, with dispersive bursts of precipitating field-aligned electrons, although on longer timescales the bursty ions and the bursty electrons are correlated. 45 refs., 9 figs.

  12. Parallel Distributed Implementation of Truss Optimization on a Local Area Network

    Institute of Scientific and Technical Information of China (English)

    唐天兵; 韦凌云; 严毅; 韦日钰

    2004-01-01

    A two-level optimization method for the design of complex truss and parallel distributed implementation on a LAN is presented using parallel virtual machine (PVM) for Win 32 as message passing between PCs. The volumes of truss are minimized by decomposing the original optimization problem into a number of bar optimization problems executed concurrently and a coordinate optimization problem, subject to constraints on nodal displacements, and stresses, buckling and crippling of bars, etc. The system sensitivity analysis that derives the partial derivatives of displacements and stresses with respect to areas are also performed in parallel so as to shorten the analysis time. The convergence and the speedup performances as well as parallel computing efficiency of the method are investigated by the optimization examples of a 52-bar planar truss and a 3 126-bar three-dimensional truss. The results show that the ideal speedup is obtained in the cases of 2 PCs for the 3 126-bar space truss optimization, while no speedup is observed for the 52-bar truss. It is concluded that ( 1 ) the parallel distributed algorithm proposed is efficient on the PC-based LAN for the coarsegrained large optimization problem; (2) to get a high speedup, the problem granularity should match with the network granularity;and (3) the larger the problem size is, the higher the parallel efficiency is.

  13. Conventional and conformal technique of external beam radiotherapy in locally advanced cervical cancer: Dose distribution, tumor response, and side effects

    Science.gov (United States)

    Mutrikah, N.; Winarno, H.; Amalia, T.; Djakaria, M.

    2017-08-01

    The objective of this study was to compare conventional and conformal techniques of external beam radiotherapy (EBRT) in terms of the dose distribution, tumor response, and side effects in the treatment of locally advanced cervical cancer patients. A retrospective cohort study was conducted on cervical cancer patients who underwent EBRT before brachytherapy in the Radiotherapy Department of Cipto Mangunkusumo Hospital. The prescribed dose distribution, tumor response, and acute side effects of EBRT using conventional and conformal techniques were investigated. In total, 51 patients who underwent EBRT using conventional techniques (25 cases using Cobalt-60 and 26 cases using a linear accelerator (LINAC)) and 29 patients who underwent EBRT using conformal techniques were included in the study. The distribution of the prescribed dose in the target had an impact on the patient’s final response to EBRT. The complete response rate of patients to conformal techniques was significantly greater (58%) than that of patients to conventional techniques (42%). No severe acute local side effects were seen in any of the patients (Radiation Therapy Oncology Group (RTOG) grades 3-4). The distribution of the dose and volume to the gastrointestinal tract affected the proportion of mild acute side effects (RTOG grades 1-2). The urinary bladder was significantly greater using conventional techniques (Cobalt-60/LINAC) than using conformal techniques at 72% and 78% compared to 28% and 22%, respectively. The use of conformal techniques in pelvic radiation therapy is suggested in radiotherapy centers with CT simulators and 3D Radiotherapy Treatment Planning Systems (RTPSs) to decrease some uncertainties in radiotherapy planning. The use of AP/PA pelvic radiation techniques with Cobalt-60 should be limited in body thicknesses equal to or less than 18 cm. When using conformal techniques, delineation should be applied in the small bowel, as it is considered a critical organ according to RTOG

  14. Spatial Distributions of HIV Infection in an Endemic Area of Western Kenya: Guiding Information for Localized HIV Control and Prevention.

    Directory of Open Access Journals (Sweden)

    Tomonori Hoshi

    Full Text Available HIV is still a major health problem in developing countries. Even though high HIV-risk-taking behaviors have been reported in African fishing villages, local distribution patterns of HIV infection in the communities surrounding these villages have not been thoroughly analyzed. The objective of this study was to investigate the geographical distribution patterns of HIV infection in communities surrounding African fishing villages. In 2011, we applied age- and sex-stratified random sampling to collect 1,957 blood samples from 42,617 individuals registered in the Health and Demographic Surveillance System in Mbita, which is located on the shore of Lake Victoria in western Kenya. We used these samples to evaluate existing antibody detection assays for several infectious diseases, including HIV antibody titers. Based on the results of the assays, we evaluated the prevalence of HIV infection according to sex, age, and altitude of participating households. We also used Kulldorff's spatial scan statistic to test for HIV clustering in the study area. The prevalence of HIV at our study site was 25.3%. Compared with the younger age group (15-19 years, adults aged 30-34 years were 6.71 times more likely to be HIV-positive, and the estimated HIV-positive population among women was 1.43 times larger than among men. Kulldorff's spatial scan statistic detected one marginally significant (P = 0.055 HIV-positive and one significant HIV-negative cluster (P = 0.047 in the study area. These results suggest a homogeneous HIV distribution in the communities surrounding fishing villages. In addition to individual behavior, more complex and diverse factors related to the social and cultural environment can contribute to a homogeneous distribution pattern of HIV infection outside of African fishing villages. To reduce rates of transmission in HIV-endemic areas, HIV prevention and control programs optimized for the local environment need to be developed.

  15. Species Abundance Distribution of Ectoparasites on Norway rats (Rattus norvegicus from a Localized Area in Southwest China

    Directory of Open Access Journals (Sweden)

    Xian Guo Guo

    2016-01-01

    Full Text Available Background: The species of ectoparasites that live on a specific host in a geographical region form an ectoparasite community. Species abundance distributions describe the number of individuals observed for each different species that is encountered within a community. Based on properties of the species abundance distribution, the expected total number of species present in the community can be estimated.Methods: Preston’s lognormal distribution model was used to fit the expected species abundance distribution curve. Using the expected species abundance distribution curve, we estimated the total number of expected parasite species present and the amount of species that were likely missed by our sampling in the field.Results: In total, 8040 ectoparasites (fleas, sucking lice, gamasid mites and chigger mites were collected from 431 Norway rats (Rattus norvegicus from a localized area in southwest China. These ectoparasites were identified to be 47 species from 26 genera in 10 families. The majority of ectoparasite species were chigger mites (family Trombicu­lidae while the majority of individuals were sucking lice in the family Polyplacidae. The expected species abun­dance distribution curve demonstrated the classic pattern that the majority of ectoparasite species were rare and that there were a few common species. The total expected number of ectoparasite species on R. norvegicus was estimated to be 85 species, and 38 species were likely missed by our sampling in the field.Conclusions: Norway rats harbor a large suite of ectoparasites. Future field investigations should sample large num­bers of host individuals to assess ectoparasite populations.

  16. Distributed pedestrian detection alerts based on data fusion with accurate localization.

    Science.gov (United States)

    García, Fernando; Jiménez, Felipe; Anaya, José Javier; Armingol, José María; Naranjo, José Eugenio; de la Escalera, Arturo

    2013-09-04

    Among Advanced Driver Assistance Systems (ADAS) pedestrian detection is a common issue due to the vulnerability of pedestrians in the event of accidents. In the present work, a novel approach for pedestrian detection based on data fusion is presented. Data fusion helps to overcome the limitations inherent to each detection system (computer vision and laser scanner) and provides accurate and trustable tracking of any pedestrian movement. The application is complemented by an efficient communication protocol, able to alert vehicles in the surroundings by a fast and reliable communication. The combination of a powerful location, based on a GPS with inertial measurement, and accurate obstacle localization based on data fusion has allowed locating the detected pedestrians with high accuracy. Tests proved the viability of the detection system and the efficiency of the communication, even at long distances. By the use of the alert communication, dangerous situations such as occlusions or misdetections can be avoided.

  17. Distributed Pedestrian Detection Alerts Based on Data Fusion with Accurate Localization

    Directory of Open Access Journals (Sweden)

    Arturo de la Escalera

    2013-09-01

    Full Text Available Among Advanced Driver Assistance Systems (ADAS pedestrian detection is a common issue due to the vulnerability of pedestrians in the event of accidents. In the present work, a novel approach for pedestrian detection based on data fusion is presented. Data fusion helps to overcome the limitations inherent to each detection system (computer vision and laser scanner and provides accurate and trustable tracking of any pedestrian movement. The application is complemented by an efficient communication protocol, able to alert vehicles in the surroundings by a fast and reliable communication. The combination of a powerful location, based on a GPS with inertial measurement, and accurate obstacle localization based on data fusion has allowed locating the detected pedestrians with high accuracy. Tests proved the viability of the detection system and the efficiency of the communication, even at long distances. By the use of the alert communication, dangerous situations such as occlusions or misdetections can be avoided.

  18. The State of the Art in Locally Distributed Web-Server Systems

    Directory of Open Access Journals (Sweden)

    M. Ezhilvendan

    2013-01-01

    Full Text Available The paper describes a novel algorithms for a load balancer, allocates the work to the clusters of SIP server. The several load balancing algorithms for distributing Session Initiation Protocol (SIP request to a cluster of SIP servers. This algorithm also supports the following three techniques such as CJSQ, TJSQ and TLWL. It is combine knowledge of the SIP, recognizing variability in call length, dynamic estimates of back-end server load for different SIP transactions. In this paper load balancer improves both throughput and response time. The SIP is a protocol of growing importance, with uses for VOIP, IPTV, audio conferencing, instant messaging. We present a detailed analysis of occupancy to show how our algorithms significantly reduce response time.

  19. Climate change and plant distribution: local models predict high-elevation persistence

    DEFF Research Database (Denmark)

    Randin, Christophe F.; Engler, Robin; Normand, Signe

    2009-01-01

    of habitat loss have been predicted, with associated risk of species extinction. Few coordinated across-scale comparisons have been made using data of different resolutions and geographic extents. Here, we assess whether climate change-induced habitat losses predicted at the European scale (10 × 10' grid...... in the area. Proportion of habitat loss depends on climate change scenario and study area. We find good agreement between the mismatch in predictions between scales and the fine-grain elevation range within 10 × 10' cells. The greatest prediction discrepancy for alpine species occurs in the area......Mountain ecosystems will likely be affected by global warming during the 21st century, with substantial biodiversity loss predicted by species distribution models (SDMs). Depending on the geographic extent, elevation range, and spatial resolution of data used in making these models, different rates...

  20. Skeletal growth, ultrastructure and composition of the azooxanthellate scleractinian coral Balanophyllia regia

    Science.gov (United States)

    Brahmi, C.; Meibom, A.; Smith, D. C.; Stolarski, J.; Auzoux-Bordenave, S.; Nouet, J.; Doumenc, D.; Djediat, C.; Domart-Coulon, I.

    2010-03-01

    The biomineralization process and skeletal growth dynamics of azooxanthellate corals are poorly known. Here, the growth rate of the shallow-water dendrophyllid scleractinian coral Balanophyllia regia was evaluated with calcein-labeling experiments that showed higher lateral than vertical extension. The structure, mineralogy and trace element composition of the skeleton were characterized at high spatial resolution. The epitheca and basal floor had the same ultrastructural organization as septa, indicating a common biological control over their formation. In all of these aragonitic skeletal structures, two main ultrastructural components were present: “centers of calcification” (COC) also called rapid accretion deposits (RAD) and “fibers” (thickening deposits, TD). Heterogeneity in the trace element composition, i.e., the Sr/Ca and Mg/Ca ratios, was correlated with the ultrastructural organization: magnesium was enriched by a factor three in the rapid accretion deposits compared with the thickening deposits. At the interface with the skeleton, the skeletogenic tissue (calicoblastic epithelium) was characterized by heterogeneity of cell types, with chromophile cells distributed in clusters regularly spaced between calicoblasts. Cytoplasmic extensions at the apical surface of the calicoblastic epithelium created a three-dimensional organization that could be related to the skeletal surface microarchitecture. Combined measurements of growth rate and skeletal ultrastructural increments suggest that azooxanthellate shallow-water corals produce well-defined daily growth steps.

  1. Local distribution and abundance of Cardisoma guanhumi Latreille, 1928 (Brachyura: Gecarcinidae) in southern Brazil.

    Science.gov (United States)

    Oliveira-Neto, J F; Batista, E; Metri, R; Metri, C B

    2014-02-01

    The blue land crab, Cardisoma guanhumi Latreille, 1828 (Brachyura: Gecarcinidae) is officially included in the list of over-exploited species in Brazil, although still abundantly found in the state of Santa Catarina, the southern limit of its distribution. This species was found in forested areas, gardens, and grassy areas, including crabs with carapace width larger than 80mm. The existence of this population with these characteristics is surprising, since there is only one official record of the species in the southern region. The objectives of this study are to estimate the abundance and occupation patterns of C. guanhumi in this region. Correlations with conservation were discussed. The absolute abundance of crabs in the middle of summer activity was established for an area of 100,000 m2. A smaller area was mapped and divided into sampling units for statistical analyses. We distributed approximately 240 crabs in a forested area of about 3,000 m2 and 150 crabs in grassy areas (90,000 m2). The statistical test of Kruskal-Wallis test showed that there are significant differences between the sizes of the openings of the galleries inside the forest and that located in grassy areas. In the forest, the openings tend to be much larger. Burrows were found at a distance of 150 metres from the channel. The number of galleries was higher in the forested area, although the burrows were more densely grouped in grassy areas. Although C. guanhumi seems to be adjusting well to changes caused by human occupation, small forested areas are more conducive to growth and conservation of this species.

  2. Ultrastructural relationship between the mu opioid receptor and its interacting protein, GPR177, in striatal neurons.

    Science.gov (United States)

    Reyes, Arith-Ruth S; Levenson, Robert; Berrettini, Wade; Van Bockstaele, Elisabeth J

    2010-10-28

    GPR177, the mammalian ortholog of Drosophila Wntless/Evi/Sprinter, was recently identified as a novel mu-opioid receptor (MOR) interacting protein. GPR177 is a trans-membrane protein pivotal to mediating the secretion of Wnt signaling proteins. Wnt proteins, in turn, are essential in regulating neuronal development, a phenomenon inhibited upon chronic exposure to MOR agonists such as morphine and heroin. We previously showed that GPR177 and MOR are co-localized in the mouse dorsolateral striatum; however, the nature of this interaction was not fully elucidated. Therefore, in the present study, we examined cellular substrates for interactions between GPR177 and MOR using a combined immunogold-silver and peroxidase detection approach in coronal sections in the dorsolateral segment of the striatum. Semi-quantitative analysis of the ultrastructural distribution of GPR177 and MOR in striatal somata and in dendritic processes showed that, of the somata and dendritic processes exhibiting GPR177, 32% contained MOR immunolabeling while for profiles exhibiting MOR, 37% also contained GPR177 immunoreactivity. GPR177-labeled particles were localized predominantly along both the plasma membrane and within the cytoplasm of MOR-labeled dendrites. Somata and dendritic processes that contained both GPR177 and MOR more often received symmetric (inhibitory-type) synapses from unlabeled axon terminals. To further define the phenotype of GPR177 and MOR-containing cellular profiles, triple immunofluorescence detection showed that GPR177 and MOR are localized in neurons containing the opioid peptide, enkephalin, within the dorsolateral striatum. The results provide an anatomical substrate for interactions between MOR and its interacting protein, GPR177, in striatal opioid-containing neurons that may underlie the morphological alterations produced in neurons by chronic opiate use.

  3. New locality of Hymenochaete cruenta in the Olbina nature reserve and revisiting of distribution of this fungus in Poland

    Directory of Open Access Journals (Sweden)

    Marta Brygida Kujawska

    2016-12-01

    Full Text Available Hymenochaete cruenta is a saprotrophic fungus, grown mainly on the bark of dead branches and trunks of Abies trees and thus the distribution of this fungus in Poland and other European countries is closely connected with natural range of silver fir. Despite its wide range, H. cruenta is considered as rare in the whole area of its occurrence. In this paper, we present a new locality of H. cruenta, discovered in May and September 2016 in the Olbina nature reserve (southern Wielkopolska Lowland, Kalisz Forest District. Ecological notes and macro- and microscopic feature of basidiocarps of this fungus are presented. Additionally, the current distribution of H. cruenta in Poland comprising 78 localities is provided. The rank of H. cruenta among threatened species categories in different European countries is discussed. It seems that the species is rare and threatened in Poland, and it should be still classified as “vulnerable” on the red list of macrofungi. The significance of H. cruenta for diversity of mycobiota and the necessity of further research on the dynamic of occurrence of H. cruenta inside and outside of the natural range of A. alba is underlined.

  4. Chromosomal localization of a novel retinoic acid induced gene RA28 and the protein distribution of its encoded protein

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Gene RA28 is a retinoic acid induced novel gene isolated in our laboratory previously. All-trans retinoic acid (ATRA) was used to induce lung adenocarcinoma cell line GLC-82, and RA28 was obtained by subtractive hybridization. Green fluorescent protein (GFP) has emerged as a unique tool for examining introcellular phenomena in living cells. GFP possesses an intrinsic fluorescence at 488 nm that does not require other co-factors. In this report, an eukaryotic expression plasmid pEGFP-C1-RA28 was constructed and transfected with parental cell line GLC-82 to analyze protein expression and its distribution in living cells. Moreover, radiation hybrid (RH) technique was used to localize RA28 to the chromosome. The results show that gene RA28 is mapped to the chromosome 19q13.1 region, its encoded protein is distributed on cell membrane. All the results further demonstrate that GFP and RH techniques are accurate, fast, repetitive, and will be powerful methods for investigating the gene and protein localization.

  5. Successfully Changing the Landscape of Information Distribution: Extension Food Website Reaches People Locally and Globally

    Directory of Open Access Journals (Sweden)

    Alice Henneman

    2016-02-01

    Full Text Available The goal of the Food website was to develop Internet-based content that was relevant and reached the general public and multiplier groups, such as educators, health professionals, and media outlets. The purpose of this paper was to examine whether a multi-modal approach to information delivery through increases in and changes to content, electronic mailing list creation, and social media posting impacted user access, traffic channels, and referrals from 2010 to 2014. When comparing 2010-2011 versus 2013-2014, there was a 150% increase in total pageviews, 197% increase in unique pageviews, and a 39% increase in average time spent on a page. Since 2010, the website had over 5.2 million total pageviews, 3.1 million sessions, and 2.6 million users. In 2014, top social media referrals included Pinterest, Facebook, LinkedIn, and Twitter. Age of visitors ranged from 18 to 65+, with 45% being 18-34 years old. Approximately 70% were female. Visitors came from 229 countries/territories and 18,237 different cities. The website connects Nebraska and the world to the exciting food research and information generated at the University of Nebraska-Lincoln and is playing an increasingly important role in shaping the future of food in the local and global community.

  6. Core-collapse supernova progenitor constraints using the spatial distributions of massive stars in local galaxies

    CERN Document Server

    Kangas, T; Mattila, S; Fraser, M; Kankare, E; Izzard, R G; James, P; González-Fernández, C; Maund, J R; Thompson, A

    2016-01-01

    We study the spatial correlations between the H$\\alpha$ emission and different types of massive stars in two local galaxies, the Large Magellanic Cloud (LMC) and Messier 33. We compare these to correlations derived for core-collapse supernovae (CCSNe) in the literature to connect CCSNe of different types with the initial masses of their progenitors and to test the validity of progenitor mass estimates which use the pixel statistics method. We obtain samples of evolved massive stars in both galaxies from catalogues with good spatial coverage and/or completeness, and combine them with coordinates of main-sequence stars in the LMC from the SIMBAD database. We calculate the spatial correlation of stars of different classes and spectral types with H$\\alpha$ emission. We also investigate the effects of distance, noise and positional errors on the pixel statistics method. A higher correlation with H$\\alpha$ emission is found to correspond to a shorter stellar lifespan, and we conclude that the method can be used as ...

  7. Systemic distribution, subcellular localization and differential expression of sphingosine-1-phosphate receptors in benign and malignant human tissues.

    Science.gov (United States)

    Wang, Chunyi; Mao, Jinghe; Redfield, Samantha; Mo, Yinyuan; Lage, Janice M; Zhou, Xinchun

    2014-10-01

    Five sphingosine-1-phosphate receptors (S1PR): S1PR1, S1PR2, S1PR3, S1PR4 and S1PR5 (S1PR1-5) have been shown to be involved in the proliferation and progression of various cancers. However, none of the S1PRs have been systemically investigated. In this study, we performed immunohistochemistry (IHC) for S1PR1-S1PR5 on different tissues, in order to simultaneously determine the systemic distribution, subcellular localization and expression level of all five S1PRs. We constructed tissue microarrays (TMAs) from 384 formalin-fixed paraffin-embedded (FFPE) blocks containing 183 benign and 201 malignant tissues from 34 human organs/systems. Then we performed IHC for all five S1PRs simultaneously on these TMA slides. The distribution, subcellular localization and expression of each S1PR were determined for each tissue. The data in benign and malignant tissues from the same organ/tissue were then compared using the Student's t-test. In order to reconfirm the subcellular localization of each S1PR as determined by IHC, immunocytochemistry (ICC) was performed on several malignant cell lines. We found that all five S1PRs are widely distributed in multiple human organs/systems. All S1PRs are expressed in both the cytoplasm and nucleus, except S1PR3, whose IHC signals are only seen in the nucleus. Interestingly, the S1PRs are rarely expressed on cellular membranes. Each S1PR is unique in its organ distribution, subcellular localization and expression level in benign and malignant tissues. Among the five S1PRs, S1PR5 has the highest expression level (in either the nucleus or cytoplasm), with S1PR1, 3, 2 and 4 following in descending order. Strong nuclear expression was seen for S1PR1, S1PR3 and S1PR5, whereas S1PR2 and S1PR4 show only weak staining. Four organs/tissues (adrenal gland, liver, brain and colon) show significant differences in IHC scores for the multiple S1PRs (nuclear and/or cytoplasmic), nine (stomach, lymphoid tissues, lung, ovary, cervix, pancreas, skin, soft

  8. Autoradiographic and ultrastructural studies on the human fibro-atheromatous plaque

    Energy Technology Data Exchange (ETDEWEB)

    Villaschi, S.; Spagnoli, L.G. (Universita degli Studi, Rome (Italy). Istituto di Anatomia ed Istologia Patologica)

    1983-07-01

    Foam cells, either myogenic or macrophagic, are commonly detected in experimental and human fibro-atheromatous plaques. Their role in human atherosclerosis is not yet understood. This paper reports on a preliminary autoradiographic study combined with ultrastructural observations in the human fibro-atheromatous plaque. Most of the autoradiographic silver grains appeared on foam cells and monocytelike cells, thus suggesting a local proliferation of these cells.

  9. [Distribution patterns of canopy and understory tree species at local scale in a Tierra Firme forest, the Colombian Amazonia].

    Science.gov (United States)

    Barreto-Silva, Juan Sebastian; López, Dairon Cárdenas; Montoya, Alvaro Javier Duque

    2014-03-01

    The effect of environmental variation on the structure of tree communities in tropical forests is still under debate. There is evidence that in landscapes like Tierra Firme forest, where the environmental gradient decreases at a local level, the effect of soil on the distribution patterns of plant species is minimal, happens to be random or is due to biological processes. In contrast, in studies with different kinds of plants from tropical forests, a greater effect on floristic composition of varying soil and topography has been reported. To assess this, the current study was carried out in a permanent plot of ten hectares in the Amacayacu National Park, Colombian Amazonia. To run the analysis, floristic and environmental variations were obtained according to tree species abundance categories and growth forms. In order to quantify the role played by both environmental filtering and dispersal limitation, the variation of the spatial configuration was included. We used Detrended Correspondence Analysis and Canonical Correspondence Analysis, followed by a variation partitioning, to analyze the species distribution patterns. The spatial template was evaluated using the Principal Coordinates of Neighbor Matrix method. We recorded 14 074 individuals from 1 053 species and 80 families. The most abundant families were Myristicaceae, Moraceae, Meliaceae, Arecaceae and Lecythidaceae, coinciding with other studies from Northwest Amazonia. Beta diversity was relatively low within the plot. Soils were very poor, had high aluminum concentration and were predominantly clayey. The floristic differences explained along the ten hectares plot were mainly associated to biological processes, such as dispersal limitation. The largest proportion of community variation in our dataset was unexplained by either environmental or spatial data. In conclusion, these results support random processes as the major drivers of the spatial variation of tree species at a local scale on Tierra Firme

  10. An ESPRIT-Based Approach for 2-D Localization of Incoherently Distributed Sources in Massive MIMO Systems

    Science.gov (United States)

    Hu, Anzhong; Lv, Tiejun; Gao, Hui; Zhang, Zhang; Yang, Shaoshi

    2014-10-01

    In this paper, an approach of estimating signal parameters via rotational invariance technique (ESPRIT) is proposed for two-dimensional (2-D) localization of incoherently distributed (ID) sources in large-scale/massive multiple-input multiple-output (MIMO) systems. The traditional ESPRIT-based methods are valid only for one-dimensional (1-D) localization of the ID sources. By contrast, in the proposed approach the signal subspace is constructed for estimating the nominal azimuth and elevation direction-of-arrivals and the angular spreads. The proposed estimator enjoys closed-form expressions and hence it bypasses the searching over the entire feasible field. Therefore, it imposes significantly lower computational complexity than the conventional 2-D estimation approaches. Our analysis shows that the estimation performance of the proposed approach improves when the large-scale/massive MIMO systems are employed. The approximate Cram\\'{e}r-Rao bound of the proposed estimator for the 2-D localization is also derived. Numerical results demonstrate that albeit the proposed estimation method is comparable with the traditional 2-D estimators in terms of performance, it benefits from a remarkably lower computational complexity.

  11. Localization of spatially distributed brain sources after a tensor-based preprocessing of interictal epileptic EEG data.

    Science.gov (United States)

    Albera, L; Becker, H; Karfoul, A; Gribonval, R; Kachenoura, A; Bensaid, S; Senhadji, L; Hernandez, A; Merlet, I

    2015-01-01

    This paper addresses the localization of spatially distributed sources from interictal epileptic electroencephalographic data after a tensor-based preprocessing. Justifying the Canonical Polyadic (CP) model of the space-time-frequency and space-time-wave-vector tensors is not an easy task when two or more extended sources have to be localized. On the other hand, the occurrence of several amplitude modulated spikes originating from the same epileptic region can be used to build a space-time-spike tensor from the EEG data. While the CP model of this tensor appears more justified, the exact computation of its loading matrices can be limited by the presence of highly correlated sources or/and a strong background noise. An efficient extended source localization scheme after the tensor-based preprocessing has then to be set up. Different strategies are thus investigated and compared on realistic simulated data: the "disk algorithm" using a precomputed dictionary of circular patches, a standardized Tikhonov regularization and a fused LASSO scheme.

  12. Ultrastructure of extrusomes in hypotrichous ciliate Pseudourostyla nova

    Institute of Scientific and Technical Information of China (English)

    ZHOU Yao; WANG Zhengjun; ZHANG Jun; GU Fukang

    2011-01-01

    The ultrastructure of extrusomes of the hypotrichous ciliate Pseudourostyla nova was observed in scanning and transmission electron microscopy and enzyme-cytochemistry. The results show that the distribution, morphological characteristics, morphogenesis process, and extrusive process of the extrusomes in P. nova are different from the trichocysts in Paramecium, suggesting that the extrusomes of P. nova can respond to environmental stimuli, play an important role in the defense of this species, and cannot be regarded as "trichocysts". The results also suggest that the extrusomes might be originated from the Golgi apparatus and mature in the cytoplasm; after the extrusion of mature extrusomes, the residual substance might be reabsorbed and reused by the ciliate cell via food vacuoles, and take part in material recycling of the cell.

  13. Ultrastructural and Histochemical Characterization of the Zebra Mussel Adhesive Apparatus

    Science.gov (United States)

    Farsad, Nikrooz

    Since their accidental introduction into the Great Lakes in mid- to late-1980s, the freshwater zebra mussels, Dreissena polymorpha, have colonized most lakes and waterways across eastern North America. Their rapid spread is partly attributed to their ability to tenaciously attach to hard substrates via an adhesive apparatus called the byssus, resulting in serious environmental and economic impacts. A detailed ultrastructural study of the byssus revealed a 10 nm adhesive layer at the attachment interface. Distributions of the main adhesive amino acid, 3,4-dihydroxyphenylalanine (DOPA), and its oxidizing (cross-linking) enzyme, catechol oxidase, were determined histochemically. It was found that, upon aging, DOPA levels remained high in the portion of the byssus closest to the interface, consistent with an adhesive role. In contrast, reduced levels of DOPA corresponded well with high levels of catechol oxidase in the load-bearing component of the byssus, presumably forming cross-links and increasing the cohesive strength.

  14. Distribution, biomass and local importance of tamarind trees in south-western Madagascar

    Directory of Open Access Journals (Sweden)

    Tahiry Ranaivoson

    2015-07-01

    Full Text Available The multipurpose tamarind (Tamarindus indica L. tree is important for people’s livelihood and considered as sacred in the Mahafaly region of south-western Madagascar. However, the ongoing overexploitation of this species has caused a decline of tamarind trees. In this study, the species distribution, changes in tamarind biomass and the role of traditional taboos for the conservation of this species were determined to identify opportunities and constraints for its conservation and appropriate land management planning. Semi-structured interviews (N=63 were conducted in 10 villages in the study region to obtain information regarding the utilization of tamarind trees. During field surveys, the diameter at breast height (DBH, height, wood volume and wood biomass were measured for already felled trees (N=25. Additionally, 318 trees were inventoried by measuring their DBH, height and GPS location. Using high resolution satellite images from 2004/2005 and 2012 the crown areas of all tamarind trees in six village areas were identified. Allometric equations were established to predict their wood biomass from DBH, crown surface and wood volume. Tamarind trees are mainly used as supplementary food, as well as for traditional ceremonies, charcoal production and medicinal purposes. Altogether, 0.06–0.35 trees ha−1 were observed. A regression analysis yielded high coefficients of determination for the relationships between DBH and wood biomass (r2=0.98, DBH and crown area (r2=0.72, and crown area and wood biomass (r2=0.71. From 2004/2005 to 2012, wood biomass losses of 12%–90% were caused by charcoal production and slash and burn agriculture. The traditionally sacred status of the tree has become insufficient to secure its conservation in the Mahafaly region.

  15. A Local Distributed Peer-to-Peer Algorithm Using Multi-Party Optimization Based Privacy Preservation for Data Mining Primitive Computation

    Data.gov (United States)

    National Aeronautics and Space Administration — This paper proposes a scalable, local privacy-preserving algorithm for distributed peer-to-peer (P2P) data aggregation useful for many advanced data mining/analysis...

  16. Spectral narrowing and spin echo for localized carriers with heavy-tailed L evy distribution of hopping times

    Energy Technology Data Exchange (ETDEWEB)

    Yue, Z. [Univ. of Utah, Salt Lake City, UT (United States); Mkhitaryan, Vagharsh [Ames Lab. and Iowa State Univ., Ames, IA (United States); Raikh, M. E. [Univ. of Utah, Salt Lake City, UT (United States)

    2016-02-02

    We study analytically the free induction decay and the spin echo decay originating from the localized carriers moving between the sites which host random magnetic fields. Due to disorder in the site positions and energies, the on-site residence times, , are widely spread according to the L evy distribution. The power-law tail ∝ τ-1-∝ in the distribution of does not affect the conventional spectral narrowing for α > 2, but leads to a dramatic acceleration of the free induction decay in the domain 2 > α > 1. The next abrupt acceleration of the decay takes place as becomes smaller than 1. In the latter domain the decay does not follow a simple-exponent law. To capture the behavior of the average spin in this domain, we solve the evolution equation for the average spin using the approach different from the conventional approach based on the Laplace transform. Unlike the free induction decay, the tail in the distribution of the residence times leads to the slow decay of the spin echo. The echo is dominated by realizations of the carrier motion for which the number of sites, visited by the carrier, is minimal.

  17. Seeding method influences warm-season grass abundance and distribution but not local diversity in grassland restoration

    Science.gov (United States)

    Yurkonis, Kathryn A.; Wilsey, Brian J.; Moloney, Kirk A.; Drobney, Pauline; Larson, Diane L.

    2010-01-01

    Ecological theory predicts that the arrangement of seedlings in newly restored communities may influence future species diversity and composition. We test the prediction that smaller distances between neighboring seeds in drill seeded grassland plantings would result in lower species diversity, greater weed abundance, and larger conspecific patch sizes than otherwise similar broadcast seeded plantings. A diverse grassland seed mix was either drill seeded, which places seeds in equally spaced rows, or broadcast seeded, which spreads seeds across the ground surface, into 24 plots in each of three sites in 2005. In summer 2007, we measured species abundance in a 1 m2 quadrat in each plot and mapped common species within the quadrat by recording the most abundant species in each of 64 cells. Quadrat-scale diversity and weed abundance were similar between drilled and broadcast plots, suggesting that processes that limited establishment and controlled invasion were not affected by such fine-scale seed distribution. However, native warm-season (C4) grasses were more abundant and occurred in less compact patches in drilled plots. This difference in C4 grass abundance and distribution may result from increased germination or vegetative propagation of C4 grasses in drilled plots. Our findings suggest that local plant density may control fine-scale heterogeneity and species composition in restored grasslands, processes that need to be further investigated to determine whether seed distributions can be manipulated to increase diversity in restored grasslands.

  18. A hybrid downscaling procedure for estimating the vertical distribution of ambient temperature in local scale

    Science.gov (United States)

    Yiannikopoulou, I.; Philippopoulos, K.; Deligiorgi, D.

    2012-04-01

    The vertical thermal structure of the atmosphere is defined by a combination of dynamic and radiation transfer processes and plays an important role in describing the meteorological conditions at local scales. The scope of this work is to develop and quantify the predictive ability of a hybrid dynamic-statistical downscaling procedure to estimate the vertical profile of ambient temperature at finer spatial scales. The study focuses on the warm period of the year (June - August) and the method is applied to an urban coastal site (Hellinikon), located in eastern Mediterranean. The two-step methodology initially involves the dynamic downscaling of coarse resolution climate data via the RegCM4.0 regional climate model and subsequently the statistical downscaling of the modeled outputs by developing and training site-specific artificial neural networks (ANN). The 2.5ox2.5o gridded NCEP-DOE Reanalysis 2 dataset is used as initial and boundary conditions for the dynamic downscaling element of the methodology, which enhances the regional representivity of the dataset to 20km and provides modeled fields in 18 vertical levels. The regional climate modeling results are compared versus the upper-air Hellinikon radiosonde observations and the mean absolute error (MAE) is calculated between the four grid point values nearest to the station and the ambient temperature at the standard and significant pressure levels. The statistical downscaling element of the methodology consists of an ensemble of ANN models, one for each pressure level, which are trained separately and employ the regional scale RegCM4.0 output. The ANN models are theoretically capable of estimating any measurable input-output function to any desired degree of accuracy. In this study they are used as non-linear function approximators for identifying the relationship between a number of predictor variables and the ambient temperature at the various vertical levels. An insight of the statistically derived input

  19. Plantar fibromatosis: an immunohistochemical and ultrastructural study.

    Science.gov (United States)

    de Palma, L; Santucci, A; Gigante, A; Di Giulio, A; Carloni, S

    1999-04-01

    The analogies between plantar fibromatosis and Dupuytren's disease (palmar fibromatosis) are well known. The latter is clinically more frequent and has been the object of extensive immunohistochemical and ultrastructural studies, with a view to investigating its pathogenesis. By contrast, such data on plantar fibromatosis are quite scarce. A histochemical, immunohistochemical, and ultrastructural study was performed on nodule tissue from six patients who were subjected to total fasciectomy for plantar fibromatosis. The study of myofibroblasts revealed features suggestive of their fibroblastic origin and evidenced a cytoskeleton and an extracellular filamentous system that could enable myofibroblasts to generate and exert the intracellular forces that contribute to the contraction of the aponeurosis. These aspects are similar to those observed in Dupuytren's disease and seem to lend support to the theory that the two diseases are expressions of the same disorder.

  20. Wisconsin builds a distributed resources collaborative: Looking for local solutions that work

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, C.

    1995-12-01

    I`d like to tell you how I got involved in the DR Collaborative and why I`m here. John Nesbitt asked me to come, to be the public advocate, the bumblebee on the EPRI body politic. What follows is my own thought, not that of John or my fellow collaborators, who may or may not agree with me. How did I come to know John Nesbitt? In August 1991, I found that some Wisconsin utilities intended to run a 138 kV transmission line across my property, along the driveway where my kids ride their bikes, along the high ground where we walk to escape the mosquitoes in the summer, where we ski cross-country and admire the snowy view in the winter. As a result, I became intensely interested in the electric power business. One thing led to another. I got on the Board of Wisconsin Demand-Side Demonstrations (WDSD), representing a group called the Citizens` Utility Board (CUB). I met Mr. Nesbitt. We shared an interest in distributed resources (DR). Along with some others, we conspired to initiate the Targeted Area Planning (TAP) collaborative. TAP is what we call DR in Wisconsin. I began to talk in acronyms. The simple truth is, I detest transmission lines. And, since transmission lines are invariably hooked up to central generation, I have no love for big power plants either. That whole system approach looks excessive and outdated to me, a vestige of the nineteenth century, Jules Verne without the romance. My opinion is, who needs it? I am aware that my opinion is not shared by everyone. I grant you that transmission lines might be a mite more acceptable if the thousands of landowners like me who presently subsidize their existence were receiving compensation, say an annual commodity transfer fee, that reflected some small portion of the value of transmission lines in the present system. That is certainly not the case, and if it were, the present system, when and if deregulated, would price itself out of existence all the more quickly.

  1. Enhanced effects of nonisotopic hafnium chloride in methanol as a substitute for uranyl acetate in TEM contrast of ultrastructure of fungal and plant cells.

    Science.gov (United States)

    Ikeda, Ken-Ichi; Inoue, Kanako; Kanematsu, Satoko; Horiuchi, Yoshitaka; Park, Pyoyun

    2011-09-01

    This ultrastructural study showed that nonisotopic methanolic hafnium chloride and aqueous lead solution was an excellent new electron stain for enhancing TEM contrasts of fungal and plant cell structures. The ultrastructural definition provided by the new stain was often superior to that provided by conventional staining with uranyl acetate and lead. Definition of fine ultrastructure was also supported by quantitative data on TEM contrast ratios of organelles and components in fungal and plant cells. In particular, polysaccharides, which were localized in cell walls, glycogen particles, starch grains, and plant Golgi vesicle components, were much more reactive to the new stain than to the conventional one. The new nonisotopic stain is useful for enhancing the contrast of ultrastructure in biological tissues and is a safer alternative to uranyl acetate. Copyright © 2010 Wiley-Liss, Inc.

  2. Ultrastructure of the mouse spinal cord ependyma.

    OpenAIRE

    Bjugn, R; Haugland, H K; Flood, P R

    1988-01-01

    This study was done in order to investigate the normal ultrastructure of well-preserved mouse spinal canal ependyma using light, scanning and transmission electron microscopy. The ependymal lining was found to consist of a simple, cuboidal epithelium essentially similar to the unspecialized cuboidal ependyma of the brain ventricles. Apart from great variation in kinociliary density, no intracellular difference was noted between the ependymal cells. In contrast to earlier findings, indications...

  3. [Ultrastructural study of embryonic development in Grantia compressa F. (Porifera, Calcarea)].

    Science.gov (United States)

    Gallissian, M F

    1983-01-01

    The embryonic development of Grantia compressa is studied by means of the electron microscope from the blastula inside the mesenchyme to the mature amphi-blastula released in the excurrent canals. The study of the different cellular categories of the embryon shows the distribution of the vitellin inclusions and their evolution. The ultrastructure of the "cellules en croix" is not in favour of a photoreceptor part.

  4. Simulation of Blast Loading on an Ultrastructurally-based Computational Model of the Ocular Lens

    Science.gov (United States)

    2015-10-01

    public release; distribution unlimited The views, opinions and/or findings contained in this report are those of the author(s) and should not be...cells) is stressed by the passing shock wave. Traumatic cataract can result in a partially or fully clouded lens, complete dislo- cation of the lens...CSLM), and type IV collagen ultrastructure in lens capsule using cyro- electron tomography: 6b - On as-received porcine lens capsules, image type IV

  5. Nematodes ultrastructure: complex systems and processes.

    Science.gov (United States)

    Basyoni, Maha M A; Rizk, Enas M A

    2016-12-01

    Nematode worms are among the most ubiquitous organisms on earth. They include free-living forms as well as parasites of plants, insects, humans and other animals. Recently, there has been an explosion of interest in nematode biology, including the area of nematode ultrastructure. Nematodes are round with a body cavity. They have one way guts with a mouth at one end and an anus at the other. They have a pseudocoelom that is lined on one side with mesoderm and on the other side with endoderm. It appears that the cuticle is a very complex and evolutionarily plastic feature with important functions involving protection, body movement and maintaining shape. They only have longitudinal muscles so; they seem to thrash back and forth. While nematodes have digestive, reproductive, nervous and excretory systems, they do not have discrete circulatory or respiratory systems. Nematodes use chemosensory and mechanosensory neurons embedded in the cuticle to orient and respond to a wide range of environmental stimuli. Adults are made up of roughly 1000 somatic cells and hundreds of those cells are typically associated with the reproductive systems. Nematodes ultrastructure seeks to provide studies which enable their use as models for diverse biological processes including; human diseases, immunity, host-parasitic interactions and the expression of phylogenomics. The latter has, however, not been brought into a single inclusive entity. Consequently, in the current review we tried to provide a comprehensive approach to the current knowledge available for nematodes ultrastructures.

  6. Changes in root gravitropism, ultrastructure, and calcium balance of pea root statocytes induced by A23187

    Science.gov (United States)

    Belyavskaya, N.

    The role for calcium in the regulation of a wide variety of cellular events in plants is well known. Calcium signaling has been implicated in plant gravitropism. A carboxylic acid antibiotic A23187 (calcimycin) has been widely used in biological studies since it can translocate calcium across membranes. Seedlings of Pisum sativum L. cv. Uladovsky germinated in a vertically oriented cylinder of moist filter paper soaked in water during 4.5 day had been treated with 10-5 M A23187 for 12 hr. Tips of primary roots of control and A23187-treated pea seedlings were fixed for electron microscopy and electron cytochemistry. Experiments with Pisum sativum 5- day seedlings placed horizontally for 4 h after treatment with 10 μM A23187 during 12 h found that the graviresponsiveness of their primary roots was lost completely (91 % of roots) or inhibited (24 +/- 6° in comparison with 88 +/- 8° in control). At ultrastructural level, there were observed distribution of amyloplasts around the nucleus, remarkable lengthening of statocytes, advanced vacuolization, changes in dictyosome structure, ER fragmentation, cell wall thinning in A23187-treated statocytes. Cytochemical study has indicated that statocytes exposed to calcimycin have contained a number of Ca-pyroantimonate granules detected Ca 2 + ions in organelles and hyaloplasm (unlike the control ones). The deposits were mainly associated with the plasma membrane. Among organelles, mitochondria were notable for their ability to accumulate Ca 2 +. In amyloplasts, a fine precipitate was predominately located in their stroma and envelope lumens. In cell walls, deposits of the reaction product were observed along the periphery and in the median zone. Localization of electron-dense granules of lead phosphate, which indicated Ca 2 +- ATPase activities in pea statocytes exposed to A23187, was generally consistent with that in untreated roots. Apart from plasma membrane, chromatin, and nucleolus components, the cytochemical reaction

  7. Study delay and dispersion effects in dynamic susceptibility contrast MRI based on local density random walk distribution

    Science.gov (United States)

    Li, Xingfeng; Tian, Jie; Wang, Xiaoxiang; Dai, Jianping; Ai, Lin

    2004-04-01

    The aim of this study was to assess the validation of the local density random walk (LDRW) function to correct the delayed and dispersed arterial input function (AIF) data derived from dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI). Instead of using the gamma-variate function to smooth and extrapolate the AIF curves, we suggested a method which was based on diffusion with drift approach. Forty-seven AIF curves from ten patients were segmented to test the effectiveness of the proposed method. The results of the comparisons with the gamma-variate function showed that the LDRW distribution function may provide a new means for more accurate correction of AIF curves.

  8. Localization of ANP-synthesizing cells in rat stomach

    Institute of Scientific and Technical Information of China (English)

    Chun-Hui Li; Li-Hui Pan; Chun-Yu Li; Chang-Lin Zhu; Wen-Xie Xu

    2006-01-01

    AIM: To study the morphological positive expression of antrial natriuretic peptide (ANP)-synthesizing cells and ultrastructural localization and the relationship between ANP-synthesizing cells and microvessel density in the stomach of rats and to analyze the distribution of the three histologically distinct regions of ANP-synthesizing cells.METHODS: Using immunohistochemical techniques, we studied positive expression of ANP-synthesizing cells in rat stomach. A postembedding immunogold microscopy technique was used for ultrastructural localization of ANP-synthesizing cells. Microvessel density in the rat stomach was estimated using tannic acid-ferric chloride (TAFC) method staining. Distribution of ANP-synthesizing cells were studied in different regions of rat stomach histochemically.RESULTS: Positive expression of ANP-synthesizing cells were localized in the gastric mucosa of rats. Localization of ANP-synthesizing cells identified them to be enterochrochromaffin cells (EC) by using a postembedding immunogold electron microscopy technique. EC cells were in the basal third of the cardiac mucosa region.ANP-synthesizing cells existed in different regions of rat stomach and its density was largest in the gastric cardiac region, and the distribution order of ANP-synthesizing cells in density was cardiac region, pyloric region and fundic region in mucosa layer. We have also found a close relationship between ANP-synthesizing cells and microvessel density in gastric mucosa of rats using TAFC staining.CONCLUSION: ANP-synthesizing cells are expressed in the gastric mucosa. EC synthesize ANP. There is a close relationship between ANP-synthesizing cells and microvessel density in gastric mucosa of rats.The distribution density of ANP-synthesizing cells is largest in the gastric cardiac region.

  9. The Regional and Local Distribution of Funds Allocated by the European Agricultural Fund for Rural Development in Romania

    Directory of Open Access Journals (Sweden)

    ALINA-MIRELA MARCU

    2013-01-01

    Full Text Available The objective of this study is to present and analyze the regional and local distribution of the funds allocated by the European Agricultural Fund for Rural Development (EAFRD, European fund that finances rural development in Romania, in the post-accession period. This financing instrument was created by the European Union with the order to continue the main directions of investment of Special Pre-Accession Programme for Agriculture and Rural Development (SAPARD. As a member state of the European Union, Romania observes the principles of the Common Agricultural Policy (CAP while the development of the Romanian rural area for the programming period 2007-2013 is supported by the European Community through the National Rural Development Programme (RDP. This approach pays special attention to improving the quality of life in rural areas and the diversification of the rural economy because local communities in Romania have experienced some changes in this period, while accessing EAFRD funds contributed to increased regional disparities between developed and poor areas.

  10. Distributed Position Localization and Tracking (DPLT) of Malicious Nodes in Cluster Based Mobile Ad hoc Networks (MANET)

    CERN Document Server

    Niraj, Shakhakarmi

    2012-01-01

    In this paper, a robust distributed malicious node detection and precise localization and tracking method is proposed for Cluster based Mobile Ad hoc Network (MANET). Certificate Authority (CA) node is selected as the most stable node among trusted nodes, surrounded by Registration Authority nodes (RAs) in each cluster to generate the Dynamic Demilitarized Zone (DDMZ) to defend CA from probable attackers and mitigate the authentication overhead. The RAs also co-operate with member nodes to detect a target node and determine whether it is malicious or not, by providing the public key certificate and trust value. In addition, Internet Protocol (IP) based Triangulation and multi-lateration method are deployed based on using the average time difference of Time of Arrival (ToA) and Time of Departure (ToD) of the management packets. Triangulation uses three reference nodes which are elected within each cluster based on Best Criterion Function (BCF) to localize each member node inside the cluster in 2D. Multi-latera...

  11. Factors influencing distribution and local coexistence of diploids and tetraploids of Vicia cracca: inferences from a common garden experiment.

    Science.gov (United States)

    Eliášová, Anežka; Münzbergová, Zuzana

    2017-07-01

    Vicia cracca diploids and autotetraploids are highly parapatric in Europe; tetraploids reside in western and northern part, whereas diploids occupy much drier south-eastern part. They meet together in a Central European contact zone. This distribution pattern raised questions about a transformative effect of polyploidization on plant performance and environmental tolerances. We investigated plant survival, growth, and seed production in two water regimes in a common garden experiment using seeds collected from five localities in the Central European contact zone where diploids and tetraploids occur in sympatry. Obtained data imply that tetraploids of V. cracca are not generally superior in performance to diploids. Significantly larger seeds from tetraploid mother plants collected in the field were not correlated with greater stature of the seedlings. Nonetheless, tetraploids might have a potential to out-compete diploids in the long run due to the tetraploids' ability of greater growth which manifested in the second year of cultivation. Considering the response of diploids and tetraploids to water supply, drought stressed tetraploids but not diploids produced a higher proportion of aborted seeds than watered ones, which implies that tetraploids are more drought susceptible than diploids. On the other hand, decreased plant height in drought stresses tetraploids, which simultaneously increased total seed production, may suggest that tetraploids have a greater ability to avoid local extinction under unfavourable conditions by enhancing biomass allocation into production of seeds at the cost of lower growth. The significant interaction between ploidy level and locality in several traits suggests possible polyfyletic origin of tetraploids and the necessity to clarify the history of the tetraploids in Europe.

  12. Ultrastructure of the endolymphatic sac in rat with a proposal for a new cell nomenclature

    DEFF Research Database (Denmark)

    Qvortrup, Klaus; Rostgaard, Jørgen; Bretlau, P.

    1994-01-01

    Anatomy, endolymphatic sac, ultrastructure, rat, nomenclature, methods, tubulocisternal endoplasmic reticulum......Anatomy, endolymphatic sac, ultrastructure, rat, nomenclature, methods, tubulocisternal endoplasmic reticulum...

  13. Local influence of south-east France topography and land cover on the distribution and characteristics of intense rainfall cells

    Science.gov (United States)

    Renard, Florent

    2017-04-01

    The Greater Lyon area is strongly built up, grouping 58 communes and a population of 1.3 million in approximately 500 km2. The flood risk is high as the territory is crossed by two large watercourses and by streams with torrential flow. Floods may also occur in case of runoff after heavy rain or because of a rise in the groundwater level. The whole territory can therefore be affected, and it is necessary to possess in-depth knowledge of the depths, causes and consequences of rainfall to achieve better management of precipitation in urban areas and to reduce flood risk. This study is thus focused on the effects of topography and land cover on the occurrence, intensity and area of intense rainfall cells. They are identified by local radar meteorology (C-band) combined with a processing algorithm running in a geographic information system (GIS) which identified 109,979 weighted mean centres of them in a sample composed of the five most intense rainfall events from 2001 to 2005. First, analysis of spatial distribution at an overall scale is performed, completed by study at a more detailed scale. The results show that the distribution of high-intensity rainfall cells is spread in cluster form. Subsequently, comparison of intense rainfall cells with the topography shows that cell density is closely linked with land slope but that, above all, urbanised zones feature nearly twice as many rainfall cells as farm land or forest, with more intense intensity.

  14. First-Principles Momentum Dependent Local Ansatz Approach to the Momentum Distribution Function in Iron-Group Transition Metals

    Science.gov (United States)

    Kakehashi, Yoshiro; Chandra, Sumal

    2017-03-01

    The momentum distribution function (MDF) bands of iron-group transition metals from Sc to Cu have been investigated on the basis of the first-principles momentum dependent local ansatz wavefunction method. It is found that the MDF for d electrons show a strong momentum dependence and a large deviation from the Fermi-Dirac distribution function along high-symmetry lines of the first Brillouin zone, while the sp electrons behave as independent electrons. In particular, the deviation in bcc Fe (fcc Ni) is shown to be enhanced by the narrow eg (t2g) bands with flat dispersion in the vicinity of the Fermi level. Mass enhancement factors (MEF) calculated from the jump on the Fermi surface are also shown to be momentum dependent. Large mass enhancements of Mn and Fe are found to be caused by spin fluctuations due to d electrons, while that for Ni is mainly caused by charge fluctuations. Calculated MEF are consistent with electronic specific heat data as well as recent angle resolved photoemission spectroscopy data.

  15. The Herschel Exploitation of Local Galaxy Andromeda (HELGA). IV. The distribution and properties of molecular cloud associations in M31

    CERN Document Server

    Kirk, Jason M; Fritz, Jacopo; Smith, Matthew W L; Ford, George; Baes, Maarten; Bendo, George J; De Looze, Ilse; Eales, Steve A; Gentile, Gianfranco; Gomez, Haley L; Gordon, Karl; O'Halloran, Brian; Madden, Suzanne C; Duval, Julia Roman; Verstappen, Joris; Viaene, Sebastien; Boselli, Alessandro; Cooray, Asantha; Leibouteiller, Vianney; Spinoglio, Luigi

    2013-01-01

    In this paper we present a catalogue of Giant Molecular Clouds (GMCs) in the Andromeda (M31) galaxy extracted from the Hershel Exploitation of Local Galaxy Andromeda (HELGA) dataset. GMCs are identified from the Herschel maps using a hierarchical source extraction algorithm. We present the results of this new catalogue and characterise the spatial distribution and spectral energy properties of its clouds based on the radial dust/gas properties found by Smith et al (2012). 236 GMCs in the mass range 10^4-10^7 M_sol are identified, their cumulative mass distribution is found to be proportional to M^-1.45 in agreement with earlier studies. The GMCs appear to follow the same cloud mass to L_CO correlation observed in the Milky Way. However, comparison between this catalogue and interferometry studies also shows that the GMCs are substructured below the Herschel resolution limit suggesting that we are observing associations of GMCs. Following Gordon et al. (2006), we study the spatial structure of M31 by splitting...

  16. An improved algorithm for calculating first-order reversal curve (FORC) distributions using locally-weighted regression smoothing

    Science.gov (United States)

    Harrison, R. J.; Feinberg, J. M.

    2007-12-01

    First-order reversal curves (FORCs) are a powerful method for characterizing the magnetic hysteresis properties of natural and synthetic materials, and are rapidly becoming a standard tool in rock magnetic and paleomagnetic investigations. Here we describe a modification to existing algorithms for the calculation of FORC diagrams using locally-weighted regression smoothing (often referred to as loess smoothing). Like conventional algorithms, the FORC distribution is calculated by fitting a second degree polynomial to a region of FORC space defined by a smoothing factor, N. Our method differs from conventional algorithms in two ways. Firstly, rather than a square of side (2N+1) centered on the point of interest, the region of FORC space used for fitting is defined as a span of arbitrary shape encompassing the (2N+1)2 data points closest to the point of interest. Secondly, data inside the span are given a weight that depends on their distance from the point being evaluated: data closer to the point being evaluated have higher weights and have a greater effect on the fit. Loess smoothing offers two advantages over current methods. Firstly, it allows the FORC distribution to be calculated using a constant smoothing factor all the way to the Hc = 0 axis. This eliminates possible distortions to the FORC distribution associated with reducing the smoothing factor close to the Hc = 0 axis, and does not require use of the extended FORC formalism and the reversible ridge, which swamps the low-coercivity signal. Secondly, it allows finer control over the degree of smoothing applied to the data, enabling automated selection of the optimum smoothing factor for a given FORC measurement, based on an analysis of the standard deviation of the fit residuals. The new algorithm forms the basis for FORCinel, a new suite of FORC analysis tools for Igor Pro (www.wavemetrics.com), freely available on request from the authors.

  17. Cutaneous epithelioid cell histiocytoma: immunohistochemical and ultrastructural findings suggesting endothelial origin.

    Science.gov (United States)

    Manente, L; Schmitt, I; Onetti, A M; Peris, K; Caracciolo, E; Chimenti, S

    1997-10-01

    A 13-year-old boy presented with a polypoid nodule localized in the groin. Although the clinical and histopathological features corresponded to previously described diagnostic criteria of epithelioid cell histiocytoma, immunohistochemical and ultrastructural findings suggested vascular differentiation of the epithelioid cells. In particular, the immunohistochemical negativity of the epithelioid cell elements for Factor XIIIa failed to substantiate the previously forwarded hypothesis that this lesion represents a dendrocytoma. Instead, the presence of histiocytoid, vacuolated cells occasionally containing sparse red blood cells, positive staining for Factor VIII-related antigen, and ultrastructural evidence of endothelial characteristics in epithelioid neoplastic cells favor the hypothesis that "epithelioid cell histiocytoma" is of endothelial origin. We suggest the descriptive term cutaneous histiocytoid hemangioendothelioma for this lesion.

  18. Revealing 3D Ultrastructure and Morphology of Stem Cell Spheroids by Electron Microscopy.

    Science.gov (United States)

    Jaros, Josef; Petrov, Michal; Tesarova, Marketa; Hampl, Ales

    2017-01-01

    Cell culture methods have been developed in efforts to produce biologically relevant systems for developmental and disease modeling, and appropriate analytical tools are essential. Knowledge of ultrastructural characteristics represents the basis to reveal in situ the cellular morphology, cell-cell interactions, organelle distribution, niches in which cells reside, and many more. The traditional method for 3D visualization of ultrastructural components, serial sectioning using transmission electron microscopy (TEM), is very labor-intensive due to contentious TEM slice preparation and subsequent image processing of the whole collection. In this chapter, we present serial block-face scanning electron microscopy, together with complex methodology for spheroid formation, contrasting of cellular compartments, image processing, and 3D visualization. The described technique is effective for detailed morphological analysis of stem cell spheroids, organoids, as well as organotypic cell cultures.

  19. Inter-relationships of haplosporidians deduced from ultrastructural studies

    NARCIS (Netherlands)

    Hine, P.M.; Carnegie, R.B.; Burreson, E.M.; Engelsma, M.Y.

    2009-01-01

    We reviewed papers reporting haplosporidian ultrastructure to compare inter-relationships based on ultrastructure with those based on molecular data, to identify features that may be important in haplosporidian taxonomy, and to consider parasite taxonomy in relation to host taxonomy. There were link

  20. Ultrastructural changes in goat interspecies and intraspecies reconstructed early embryos

    DEFF Research Database (Denmark)

    Tao, Yong; Gheng, Lizi; Zhang, Meiling

    2008-01-01

    The low efficiency of somatic cell nuclear transfer may be related to the ultrastructural deviations of reconstructed embryos. The present study investigated ultrastructural differences between in vivo-produced and cloned goat embryos, including intra- and interspecies embryos. Goat ear fibroblast...

  1. Ultrastructure of interstitial cells in subserosa of human colon

    DEFF Research Database (Denmark)

    Rumessen, Jüri Johannes; Vanderwinden, Jean-Marie; Hansen, Alastair;

    2013-01-01

    We studied the ultrastructure of interstitial cells in the subserosal/adventitial layer in human colon. An interstitial cell type with an ultrastructure intermediate between fibroblast-like cells (FLC) and interstitial cells of Cajal was identified (IC-SS). IC-SS had thin and flattened branching...

  2. Predicting the impacts of climate change on animal distributions: the importance of local adaptation and species' traits

    Energy Technology Data Exchange (ETDEWEB)

    HELLMANN, J. J.; LOBO, N. F.

    2011-12-20

    The geographic range limits of many species are strongly affected by climate and are expected to change under global warming. For species that are able to track changing climate over broad geographic areas, we expect to see shifts in species distributions toward the poles and away from the equator. A number of ecological and evolutionary factors, however, could restrict this shifting or redistribution under climate change. These factors include restricted habitat availability, restricted capacity for or barriers to movement, or reduced abundance of colonists due the perturbation effect of climate change. This research project examined the last of these constraints - that climate change could perturb local conditions to which populations are adapted, reducing the likelihood that a species will shift its distribution by diminishing the number of potential colonists. In the most extreme cases, species ranges could collapse over a broad geographic area with no poleward migration and an increased risk of species extinction. Changes in individual species ranges are the processes that drive larger phenomena such as changes in land cover, ecosystem type, and even changes in carbon cycling. For example, consider the poleward range shift and population outbreaks of the mountain pine beetle that has decimated millions of acres of Douglas fir trees in the western US and Canada. Standing dead trees cause forest fires and release vast quantities of carbon to the atmosphere. The beetle likely shifted its range because it is not locally adapted across its range, and it appears to be limited by winter low temperatures that have steadily increased in the last decades. To understand range and abundance changes like the pine beetle, we must reveal the extent of adaptive variation across species ranges - and the physiological basis of that adaptation - to know if other species will change as readily as the pine beetle. Ecologists tend to assume that range shifts are the dominant

  3. Ultrastructural studies of the gray platelet syndrome.

    Science.gov (United States)

    White, J G

    1979-05-01

    The gray platelet syndrome (GPS) is a rare inherited disorder in which peripheral blood platelets are relatively large, vacuolated, and almost devoid of cytoplasmic granulation. In the present study we have evaluated the ultrastructure and cytochemistry of platelets from 2 patients with the GPS to determine precisely which organelles are missing from their cells. The findings indicate that gray platelets contain normal numbers of mitochondria, dense bodies, peroxisomes, and lysosomes but specifically lack alpha-granules. Preliminary studies of megakaryocytes from 1 of the 2 patients suggest that the defect in granule formation may lie at the level of the Golgi zone.

  4. The matter distribution in the local Universe as derived from galaxy groups in SDSS DR12 and 2MRS

    Science.gov (United States)

    Saulder, Christoph; van Kampen, Eelco; Chilingarian, Igor V.; Mieske, Steffen; Zeilinger, Werner W.

    2016-11-01

    Context. Friends-of-friends algorithms are a common tool to detect galaxy groups and clusters in large survey data. In order to be as precise as possible, they have to be carefully calibrated using mock catalogues. Aims: We create an accurate and robust description of the matter distribution in the local Universe using the most up-to-date available data. This will provide the input for a specific cosmological test planned as follow-up to this work, and will be useful for general extragalactic and cosmological research. Methods: We created a set of galaxy group catalogues based on the 2MRS and SDSS DR12 galaxy samples using a friends-of-friends based group finder algorithm. The algorithm was carefully calibrated and optimised on a new set of wide-angle mock catalogues from the Millennium simulation, in order to provide accurate total mass estimates of the galaxy groups taking into account the relevant observational biases in 2MRS and SDSS. Results: We provide four different catalogues: (i) a 2MRS based group catalogue; (ii) an SDSS DR12 based group catalogue reaching out to a redshift z = 0.11 with stellar mass estimates for 70% of the galaxies; (iii) a catalogue providing additional fundamental plane distances for all groups of the SDSS catalogue that host elliptical galaxies; (iv) a catalogue of the mass distribution in the local Universe based on a combination of our 2MRS and SDSS catalogues. Conclusions: While motivated by a specific cosmological test, three of the four catalogues that we produced are well suited to act as reference databases for a variety of extragalactic and cosmological science cases. Our catalogue of fundamental plane distances for SDSS groups provides further added value to this paper. The full catalogues (Tables A.1 to A.8) are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/596/A14

  5. Local distribution of wall static pressure and heat transfer on a rough flat plate impinged by a slot air jet

    Science.gov (United States)

    Meda, Adimurthy; Katti, Vadiraj V.

    2017-08-01

    The present work experimentally investigates the local distribution of wall static pressure and the heat transfer coefficient on a rough flat plate impinged by a slot air jet. The experimental parameters include, nozzle-to-plate spacing (Z /D h = 0.5-10.0), axial distance from stagnation point ( x/D h ), size of detached rib ( b = 4-12 mm) and Reynolds number ( Re = 2500-20,000). The wall static pressure on the surface is recorded using a Pitot tube and a differential pressure transmitter. Infrared thermal imaging technique is used to capture the temperature distribution on the target surface. It is observed that, the maximum wall static pressure occurs at the stagnation point ( x/D h = 0) for all nozzle-to-plate spacing ( Z/D h ) and rib dimensions studied. Coefficient of wall static pressure ( C p ) decreases monotonically with x/D h . Sub atmospheric pressure is evident in the detached rib configurations for jet to plate spacing up to 6.0 for all ribs studied. Sub atmospheric region is stronger at Z/D h = 0.5 due to the fluid accelerating under the rib. As nozzle to plate spacing ( Z/D h ) increases, the sub-atmospheric region becomes weak and vanishes gradually. Reasonable enhancement in both C p as well as Nu is observed for the detached rib configuration. Enhancement is found to decrease with the increase in the rib width. The results of the study can be used in optimizing the cooling system design.

  6. Photo-electron momentum distribution and electron localization studies from laser-induced atomic and molecular dissociations

    Science.gov (United States)

    Ray, Dipanwita

    The broad objective of ultrafast strong-field studies is to be able to measure and control atomic and molecular dynamics on a femtosecond timescale. This thesis work has two major themes: (1) Study of high-energy photoelectron distributions from atomic targets. (2) Electron localization control in atomic and molecular reactions using shaped laser pulses. The first section focuses on the study of photoelectron diffraction patterns of simple atomic targets to understand the target structure. We measure the full vector momentum spectra of high energy photoelectrons from atomic targets (Xe, Ar and Kr) generated by intense laser pulses. The target dependence of the angular distribution of the highest energy photoelectrons as predicted by Quantitative Rescattering Theory (QRS) is explored. More recent developments show target structure information can be retrieved from photoelectrons over a range of energies, from 4Up up to 10Up, independent of the peak intensity at which the photoelectron spectra have been measured. Controlling the fragmentation pathways by manipulating the pulse shape is another major theme of ultrafast science today. In the second section we study the asymmetry of electron (and ion) emission from atoms (and molecules) by interaction with asymmetric pulses formed by the superposition of two colors (800 & 400 nm). Xe electron momentum spectra obtained as a function of the two-color phase exhibit a pronounced asymmetry. Using QRS theory we can analyze this asymmetric yield of the high energy photoelectrons to determine accurately the laser peak intensity and the absolute phase of the two-color electric field. This can be used as a standard pulse calibration method for all two-color studies. Experiments showing strong left-right asymmetry in D+ ion yield from D2 molecules using two-color pulses is also investigated. The asymmetry effect is found to be very ion-energy dependent.

  7. Local adaptation constrains the distribution potential of heat-tolerant Symbiodinium from the Persian/Arabian Gulf.

    Science.gov (United States)

    D'Angelo, Cecilia; Hume, Benjamin C C; Burt, John; Smith, Edward G; Achterberg, Eric P; Wiedenmann, Jörg

    2015-12-01

    The symbiotic association of corals and unicellular algae of the genus Symbiodinium in the southern Persian/Arabian Gulf (PAG) display an exceptional heat tolerance, enduring summer peak temperatures of up to 36 °C. As yet, it is not clear whether this resilience is related to the presence of specific symbiont types that are exclusively found in this region. Therefore, we used molecular markers to identify the symbiotic algae of three Porites species along >1000 km of coastline in the PAG and the Gulf of Oman and found that a recently described species, Symbiodinium thermophilum, is integral to coral survival in the southern PAG, the world's hottest sea. Despite the geographic isolation of the PAG, we discovered that representatives of the S. thermophilum group can also be found in the adjacent Gulf of Oman providing a potential source of thermotolerant symbionts that might facilitate the adaptation of Indian Ocean populations to the higher water temperatures expected for the future. However, corals from the PAG associated with S. thermophilum show strong local adaptation not only to high temperatures but also to the exceptionally high salinity of their habitat. We show that their superior heat tolerance can be lost when these corals are exposed to reduced salinity levels common for oceanic environments elsewhere. Consequently, the salinity prevailing in most reefs outside the PAG might represent a distribution barrier for extreme temperature-tolerant coral/Symbiodinium associations from the PAG.

  8. The matter distribution in the local universe as derived from galaxy groups in SDSS DR12 and 2MRS

    CERN Document Server

    Saulder, Christoph; Mieske, Steffen; Zeilinger, Werner W

    2015-01-01

    Context. Friends-of-friends algorithms are a common tool to detect galaxy groups and clusters in large survey data. For them to be as precise as possible, they have to be carefully calibrated using mock-catalogues. Aims. To create an accurate and robust description of the matter distribution in the local universe using the most up-to-date available data. This will provide input for a specific cosmological test planned as follow-up to this work, and will be useful for general extra- galactic and cosmological research. Methods. We create a set of galaxy group catalogues based on the 2MRS and SDSS DR12 catalogues using a friends-of-friends based group finder algorithm. The algorithm is carefully calibrated and optimised on a new set of wide-angle mock catalogues from the Millennium simulation, such as to provide accurate total mass estimates of the galaxy groups taking into account the relevant observational biases in 2MRS and SDSS. Results. We provide four different catalogues: 1) a 2MRS based group catalogue; ...

  9. Review and Analysis of Local Multipoint Distribution System (LMDS) to Deliver Voice, Data, Internet, and Video Services

    CERN Document Server

    Ahamed, S S Riaz

    2010-01-01

    Local multipoint distribution system (LMDS) uses cellular-like network architecture of microwave radios placed at the client's location and at the company's base station to deliver fixed services, mainly telephony, video and Internet access. The use of time-division multiple access (TDMA) and FDMA (frequency DMA) technology allows multiple customers within a 3-5 mile coverage radius to share the same radio channel. Customers can receive data rates between 64kbps to 155Mbps. LMDS was conceived as a broadband, fixed wireless, point-to-multipoint technology for utilization in the last mile. Throughput capacity and reliable distance of the link depends on common radio link constraints and the modulation method used - either phase-shift keying or amplitude modulation. In general deployment links of up to 5 miles (8 km) from the base station are possible, but distance is typically limited to about 1.5 miles due to rain fading attenuation constraints. Point-to-point systems are also capable of using the LMDS frequen...

  10. Observation of the Ultrastructure in Syphilitic Chancres

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiaodong(张晓东); ZHOU Jing(周晶); WANG Dequan(王德权); WU Haiyan(吴海燕); SONG Fangji(宋芳吉)

    2002-01-01

    Objective:To study the occurrence and development of primary syphilis from a morphological and structural aspect.Method: The ultrastructural pathological changes of syphilitic chancre were examined by transmission electron microscopy (TEM).Results: The pathological changes of syphilitic chancre occur mainly in the dermal layer, manifested as partial thinning or lysis of the capillary basal membrane,proliferation of capillary endothelial cells, thickening of some collagen fibers and rupture of collagen fibers surrounding T.pallidum, structural disruption of the axous of terminal nerves,disarrangement of the sheath of the myelinated nerve fibers with separation of laminae and the attachment of T. Pallidum on its outer membrane, appearance of slightly swollen T.pallidum in the plasma of the capillary endothelial cells and fibroblasts, and infiltration of neutrophils, macrophages and plasma cells containing T. Pallidum and its debris frequently lined by a clear sheath.Conclusion: The pathogenesis and injury of mechanism in primary syphilis can be explained morphologically by its characteristic ultrastructural pathological changes.

  11. Ultrastructure, biology, and phylogenetic relationships of kinorhyncha.

    Science.gov (United States)

    Neuhaus, Birger; Higgins, Robert P

    2002-07-01

    The article summarizes current knowledge mainly about the (functional) morphology and ultrastructure, but also about the biology, development, and evolution of the Kinorhyncha. The Kinorhyncha are microscopic, bilaterally symmetrical, exclusively free-living, benthic, marine animals and ecologically part of the meiofauna. They occur throughout the world from the intertidal to the deep sea, generally in sediments but sometimes associated with plants or other animals. From adult stages 141 species are known, but 38 species have been described from juvenile stages. The trunk is arranged into 11 segments as evidenced by cuticular plates, sensory spots, setae or spines, nervous system, musculature, and subcuticular glands. The ultrastructure of several organ systems and the postembryonic development are known for very few species. Almost no data are available about the embryology and only a single gene has been sequenced for a single species. The phylogenetic relationships within Kinorhyncha are unresolved. Priapulida, Loricifera, and Kinorhyncha are grouped together as Scalidophora, but arguments are found for every possible sistergroup relationship within this taxon. The recently published Ecdysozoa hypothesis suggests a closer relationship of the Scalidophora, Nematoda, Nematomorpha, Tardigrada, Onychophora, and Arthropoda.

  12. Cytological and ultrastructural studies on root tissues

    Science.gov (United States)

    Slocum, R. D.; Gaynor, J. J.; Galston, A. W.

    1984-01-01

    The anatomy and fine structure of roots from oat and mung bean seedlings, grown under microgravity conditions for 8 days aboard the Space Shuttle, was examined and compared to that of roots from ground control plants grown under similar conditions. Roots from both sets of oat seedlings exhibited characteristic monocotyledonous tissue organization and normal ultrastructural features, except for cortex cell mitochondria, which exhibited a 'swollen' morphology. Various stages of cell division were observed in the meristematic tissues of oat roots. Ground control and flight-grown mung bean roots also showed normal tissue organization, but root cap cells in the flight-grown roots were collapsed and degraded in appearance, especially at the cap periphery. At the ultrastructural level, these cells exhibited a loss of organelle integrity and a highly-condensed cytoplasm. This latter observation perhaps suggests a differing tissue sensitivity for the two species to growth conditions employed in space flight. The basis for abnormal root cap cell development is not understood, but the loss of these putative gravity-sensing cells holds potential significance for long term plant growth orientation during space flight.

  13. Ultrastructural changes in LGMD1F.

    Science.gov (United States)

    Cenacchi, Giovanna; Peterle, Enrico; Fanin, Marina; Papa, Valentina; Salaroli, Roberta; Angelini, Corrado

    2013-06-01

    A large Italo-Spanish kindred with autosomal-dominant inheritance has been reported with proximal limb and axial muscle weakness. Clinical, histological and genetic features have been described. A limb girdle muscular dystrophy 1F (LGMD1F) disease locus at chromosome 7q32.1-32.2 has been previously identified. We report a muscle pathological study of two patients (mother and daughter) from this family. Muscle morphologic findings showed increased fiber size variability, fiber atrophy, and acid-phosphatase-positive vacuoles. Immunofluorescence against desmin, myotilin, p62 and LC3 showed accumulation of myofibrils, ubiquitin binding protein aggregates and autophagosomes. The ultrastructural study confirmed autophagosomal vacuoles. Many alterations of myofibrillar component were detected, such as prominent disarray, rod-like structures with granular aspect, and occasionally, cytoplasmic bodies. Our ultrastructural data and muscle pathological features are peculiar to LGMD1F and support the hypothesis that the genetic defect leads to a myopathy phenotype associated with disarrangement of the cytoskeletal network. © 2012 Japanese Society of Neuropathology.

  14. Ultrastructural Morphology of Sperm from Human Globozoospermia

    Directory of Open Access Journals (Sweden)

    Giuseppe Ricci

    2015-01-01

    Full Text Available Globozoospermia is a rare disorder characterized by the presence of sperm with round head, lacking acrosome. Coiling tail around the nucleus has been reported since early human studies, but no specific significance has conferred it. By contrast, studies on animal models suggest that coiling tail around the nucleus could represent a crucial step of defective spermatogenesis, resulting in round-headed sperm. No observations, so far, support the transfer of this hypothesis to human globozoospermia. The purpose of this work was to compare ultrastructural morphology of human and mouse model globozoospermic sperm. Sperm have been investigated by using scanning and transmission electron microscopy. The images that we obtained show significant similarities to those described in GOPC knockout mice, an animal model of globozoospermia. By using this model as reference, we were able to identify the probable steps of the tail coiling process in human globozoospermia. Although we have no evidence that there is the same pathophysiology in man and knocked-out mouse, the similarities between these ultrastructural observations in human and those in the experimental model are very suggestive. This is the first demonstration of the existence of relevant morphological homologies between the tail coiling in animal model and human globozoospermia.

  15. Ultrastructural Morphology of Sperm from Human Globozoospermia.

    Science.gov (United States)

    Ricci, Giuseppe; Andolfi, Laura; Zabucchi, Giuliano; Luppi, Stefania; Boscolo, Rita; Martinelli, Monica; Zweyer, Marina; Trevisan, Elisa

    2015-01-01

    Globozoospermia is a rare disorder characterized by the presence of sperm with round head, lacking acrosome. Coiling tail around the nucleus has been reported since early human studies, but no specific significance has conferred it. By contrast, studies on animal models suggest that coiling tail around the nucleus could represent a crucial step of defective spermatogenesis, resulting in round-headed sperm. No observations, so far, support the transfer of this hypothesis to human globozoospermia. The purpose of this work was to compare ultrastructural morphology of human and mouse model globozoospermic sperm. Sperm have been investigated by using scanning and transmission electron microscopy. The images that we obtained show significant similarities to those described in GOPC knockout mice, an animal model of globozoospermia. By using this model as reference, we were able to identify the probable steps of the tail coiling process in human globozoospermia. Although we have no evidence that there is the same pathophysiology in man and knocked-out mouse, the similarities between these ultrastructural observations in human and those in the experimental model are very suggestive. This is the first demonstration of the existence of relevant morphological homologies between the tail coiling in animal model and human globozoospermia.

  16. Enhancement in statistical and image analysis for in situ µSXRF studies of elemental distribution and co-localization, using Dioscorea balcanica

    Energy Technology Data Exchange (ETDEWEB)

    Dučić, Tanja, E-mail: tanja.ducic@desy.de; Borchert, Manuela [DESY, Notkestrasse 85, D-22607 Hamburg (Germany); Savić, Aleksandar; Kalauzi, Aleksandar; Mitrović, Aleksandra; Radotić, Ksenija, E-mail: tanja.ducic@desy.de [University of Belgrade, Kneza Višeslava 1, 11000 Belgrade (Serbia)

    2013-03-01

    Synchrotron-radiation-based X-ray microfluorescence has been used for in situ investigation of the distribution of micronutrient and macronutrient elements in an unstained cross section of a stem of monocotyledonous liana plant Dioscorea balcanica Košanin. The elemental allocation has been quantified and the grouping/co-localization in straight and twisted stem internodes has been analysed. Synchrotron-based X-ray microfluorescence (µSXRF) is an analytical method suitable for in situ investigation of the distribution of micronutrient and macronutrient elements in several-micrometres-thick unstained biological samples, e.g. single cells and tissues. Elements are mapped and quantified at sub-p.p.m. concentrations. In this study the quantity, distribution and grouping/co-localization of various elements have been identified in straight and twisted internodes of the stems of the monocotyledonous climber D. balcanica Košanin. Three different statistical methods were employed to analyse the macro-nutrient and micronutrient distributions and co-localization. Macronutrient elements (K, P, Ca, Cl) are distributed homogeneously in both straight and twisted internodes. Micronutrient elements are mostly grouped in the vasculature and in the sclerenchyma cell layer. In addition, co-localization of micronutrient elements is much more prominent in twisted than in straight internodes. These image analyses and statistical methods provided very similar outcomes and could be applied to various types of biological samples imaged by µSXRF.

  17. Ultrastructural damage of Trypanosoma cruzi epimastigotes exposed to decomplemented immune sera.

    Science.gov (United States)

    Fernández-Presas, A M; Zavala, J T; Fauser, I B; Merchant, M T; Guerrero, L R; Willms, K

    2001-08-01

    The susceptibility of Trypanosoma cruzi epimastigotes to lysis by normal or immune sera in a complement-dependent reaction has been reported, but the effects induced directly by immune serum depleted of complement remain unstudied. The aim of this work was to study the ultrastructural alterations induced in T. cruzi epimastigotes by immune mouse or rabbit sera with or without complement. A local isolate of T. cruzi (Queretaro) was used in all experiments. Immune sera were raised in both mouse and rabbit by immunization with T. cruzi epimastigote antigens. Light microscopy showed intense agglutination of epimastigotes when incubated with decomplemented mouse or rabbit immune sera. A distinctive ultrastructural feature of this agglutination pattern was the fusion of plasma membranes and a pattern of intercrossing between subpellicular microtubules. Agglutination was associated with fragmentation of nuclear membranes and swelling of cytoplasm, Golgi cisternae, endoplasmic reticulum, mitochondria and kinetoplast membranes. Agglutinated parasites also incorporated trypan blue stain. Results of [3H]-thymidine incorporation confirmed that epimastigotes exposed to specific antibodies in the absence of complement were incapable of proliferating. Ultrastructural changes observed in epimastigote micrographs incubated with decomplemented immune mouse sera were statistically significant (P<0.001) when compared with results obtained from images after incubation with decomplemented normal mouse sera.

  18. Ultrastructural study of hippocampal cortex neurons in an experimental model of valproate encephalopathy.

    Science.gov (United States)

    Sendrowski, Krzysztof; Sobaniec, Wojciech; Sobaniec, Piotr; Sobaniec-Lotowska, Maria E

    2013-01-01

    Valproate (VPA) is a widely used antiepileptic drug. A serious neurological-outcome defined as valproate encephalopathy (VE) may rarely occur during VPA therapy. Structural abnormalities within neurons are postulated as one of the reasons for VE. The aim of this study was to assess the ultrastructure of neurons in the hippocampal cortex during the course of chronic application of VPA to rats. VPA was chronically administered to rats, intragastrically, once daily at a dose of 200 mg/kg b.w. for 1, 3, 6, 9 and 12 months. The samples of hippocampal cortex, after routine laboratory preparation, were examined by electron microscopy. The drug induced pronounced ultrastructural changes in the population of pyramidal neurons within the hippocampal cortex after 9 and 12 months of VPA administration. The most expressed abnormalities were observed within the mitochondria and manifested by fragmentation of crests and almost complete disappearance of intramitochondrial granules. Mitochondria of numerous neurons resembled large vacuolar structures. Widening, shortening and irregular distribution of rough endoplasmic reticulum was also found. A characteristic feature of damaged neurocytes in the last two phases of the experiment was the disintegration of nuclear chromatin and the presence of numerous lipofuscin deposits within hyaloplasm. These cells assumed the look of "dark neurons" and presented the ultrastructural features of apoptosis and necrosis. Our results indicate that long-term VPA administration to rats leads to aponecrosis of hippocampal neurons.

  19. Effects of iron and copper overload on the human liver: an ultrastructural study.

    Science.gov (United States)

    Fanni, D; Fanos, V; Gerosa, C; Piras, M; Dessi, A; Atzei, A; Van, Eyken P; Gibo, Y; Faa, G

    2014-01-01

    Iron and copper ions play important roles in many physiological functions of our body, even though the exact mechanisms regulating their absorption, distribution and excretion are not fully understood. Metal-related human pathology may be observed in two different clinical settings: deficiency or overload. The overload in liver cells of both trace elements leads to multiple cellular lesions. Here we report the main pathological changes observed at transmission electron microscopy in the liver of subjects affected by Beta-thalassemia and by Wilson's disease. The hepatic iron overload in beta-thalassemia patients is associated with haemosiderin storage both in Kupffer cells and in the cytoplasm of hepatocytes. Haemosiderin granules are grouped inside voluminous lysosomes, also called siderosomes. Other ultrastructural changes are fat droplets, proliferation of the smooth endoplasmic reticulum and fibrosis. Apoptosis of hepatocytes and infiltration of sinusoids by polymorphonucleates is also detected in beta-thalassemia. Ultrastructural changes in liver biopsies from Wilson's disease patients are characterized by severe mitochondrial changes, associated with an increased number of perossisomes, cytoplasmic lipid droplets and the presence of lipolysosomes, characteristic cytoplasmic bodies formed by lipid vacuoles surrounded by electron-dense lysosomes. In patients affected by Wilson's disease, nuclei are frequently involved, with disorganization of the nucleoplasm and with glycogen inclusions. On the contrary, no significant changes are detected in Kupffer cells. Our data show that iron and copper, even though are both transition metals, are responsible of different pathological changes at ultrastructural level. In particular, copper overload is associated with mitochondrial damage, whereas iron overload only rarely may cause severe mitochondrial changes. These differences underlay the need for further studies in which biochemical analyses should be associated with

  20. 非均质Euler-bernoulli梁的局部反馈定问题%Locally Distributed Feedback Stabilization of Nonuniform Euler-Bernoulli Beam

    Institute of Scientific and Technical Information of China (English)

    闫庆旭; 侯瑞鸿; 冯德兴; 齐剑冷

    2005-01-01

    In this article, we study the locally distributed feedback stabilization problem of a nonuniform Euler-Bernoulli beam. Firstly, using the semi-group theory, we establish the wellposedness of the associated closed loop system. Then by proving the uniqueness of the solution to a related ordinary differential equation, we derive the asymptotic stability of the closed loop system. Finally, by means of the piecewise multiplier method, we prove that, by either one distributed force feedback or a distributed moment feedback control, the closed loop system can be exponentially stabilized.

  1. Impact of ACTH administration on the oviductal sperm reservoir in sows: the local endocrine environment and distribution of spermatozoa.

    Science.gov (United States)

    Brandt, Y; Lang, A; Madej, A; Rodriguez-Martinez, H; Einarsson, S

    2006-03-01

    The objective of the study was to investigate if short-term stress in sows (simulated by injections of synthetic adrenocorticotrophic hormone (ACTH)) during standing oestrus had a negative effect on the local environment in the utero-tubal junction (UTJ) and isthmus and the distribution of spermatozoa in these segments. Fourteen sows were monitored for ovulation using ultrasonography in two consecutive oestruses. The sows were fitted with jugular catheters and, from onset of the second oestrus, blood samples were collected every second hour. In the 2nd oestrus, seven sows were given ACTH every second hour, from the onset of standing oestrus until the sow ovulated (ACTH-group), whereas the other seven sows remained as controls (C-group) and were given NaCl solution. The sows were artificially inseminated 16-18 h before expected ovulation. Six hours after ovulation the sows were anaesthetised, and blood samples were repeatedly taken from veins draining the uterus and the UTJ-isthmus, respectively. This oviduct was thereafter removed and divided in four adjacent sections consisting of: (i) the UTJ, (ii) the first, and (iii) the second isthmus segment prior to (iv), the ampullary-isthmic junction (AIJ) and the ampulla. The three first-mentioned segments were flushed to retrieve spermatozoa, whereas the last one was flushed to collect oocytes/ova. The number of spermatozoa attached to the zona pellucida was counted. The concentrations of cortisol in jugular blood of the ACTH-group sows during the time of ACTH-injections were significantly higher than of the C-group sows (pAIJ. In conclusion, simulated stress induced by injections of ACTH during standing oestrus results in elevated concentrations of progesterone before ovulation and may interfere with the rise of progesterone after ovulation. However, ACTH-injections appeared to augment transport of spermatozoa through the female genital tract of pigs.

  2. Pediatric non-alcoholic steatohepatitis: the first report on the ultrastructure of hepatocyte mitochondria.

    Science.gov (United States)

    Lotowska, Joanna M; Sobaniec-Lotowska, Maria E; Bockowska, Sylwia B; Lebensztejn, Dariusz M

    2014-04-21

    To investigate the ultrastructure of abnormal hepatocyte mitochondria, including their cellular and hepatic zonal distribution, in bioptates in pediatric non-alcoholic steatohepatitis (NASH). Ultrastructural investigations were conducted on biopsy liver specimens obtained from 10 children (6 boys and 4 girls) aged 2-14 years with previously clinicopathologically diagnosed NASH. The disease was diagnosed if liver biopsy revealed steatosis, inflammation, ballooned hepatocytes, Mallory hyaline, or focal necrosis, varying degrees of fibrosis in the absence of clinical, serological, or histological findings of infectious liver diseases, autoimmune hepatitis, metabolic liver diseases, or celiac disease. For ultrastructural analysis, fresh small liver blocks (1 mm(3) volume) were fixed in a solution containing 2% paraformaldehyde and 2.5% glutaraldehyde in 0.1 mol/L cacodylate buffer. The specimens were postfixed in osmium tetroxide, subsequently dehydrated through a graded series of ethanols and propylene oxide, and embedded in Epon 812. The material was sectioned on a Reichert ultramicrotome to obtain semithin sections, which were stained with methylene blue in sodium borate. Ultrathin sections were contrasted with uranyl acetate and lead citrate, and examined using an Opton EM 900 transmission electron microscope. Ultrastructural analysis of bioptates obtained from children with non-alcoholic steatohepatitis revealed characteristic repetitive mitochondrial abnormalities within hepatocytes; mainly mitochondrial polymorphisms such as megamitochondria, loss of mitochondrial cristae, and the presence of linear crystalline inclusions within the mitochondrial matrix of an increased electron density. The crystalline inclusions were particularly evident within megamitochondria (MMC), which seemed to be distributed randomly both within the hepatic parenchymal cell and the zones of hepatic lobule, without special variations in abundance. The inclusions appeared as bundles viewed

  3. Histopathological confirmation of similar intramucosal distribution of fluorescein in both intravenous administration and local mucosal application for probe-based confocal laser endomicroscopy of the normal stomach.

    Science.gov (United States)

    Nonaka, Kouichi; Ohata, Ken; Ban, Shinichi; Ichihara, Shin; Takasugi, Rumi; Minato, Yohei; Tashima, Tomoaki; Matsuyama, Yasushi; Takita, Maiko; Matsuhashi, Nobuyuki; Neumann, Helmut

    2015-12-16

    Probe-based confocal laser endomicroscopy (pCLE) is capable of acquiring in vivo magnified cross-section images of the gastric mucosa. Intravenous injection of fluorescein sodium is used for confocal imaging. However, it is still under debate if local administration of the dye to the mucosa is also effective for confocal imaging as it is not yet clear if topical application also reveals the intramucosal distribution of fluorescein. The objective of this study was to evaluate the intramucosal distribution of fluorescein sodium after topical application and to compare the distribution to the conventional intravenous injection used for confocal imaging. pCLE of the stomach uninfected with Helicobacter pylori was performed in a healthy male employing intravenous administration and local mucosal application of fluorescein. The mucosa of the lower gastric body was biopsied 1 min and 5 min after intravenous administration or local mucosal application of fluorescein, and the distribution of fluorescein in the biopsy samples was examined histologically. Green fluorescence was already observed in the cytoplasm of fundic glandular cells in the biopsied deep mucosa 1 min after local mucosal application of fluorescein. It was also observed in the foveolar lumen and inter-foveolar lamina propria, although it was noted at only a few sites. In the tissue biopsied 5 min after the local mucosal application of fluorescein, green fluorescence was more frequently noted in the cytoplasm of fundic glandular cells than in that 1 min after the local mucosal application of fluorescein, although obvious green fluorescence was not identified in the foveolar lumen or inter-foveolar lamina propria. The distribution of intravenously administered fluorescein in the cytoplasm of fundic glandular cells was also clearly observed similarly to that after local mucosal application of fluorescein. Green fluorescence in more cells was observed in many cells 5 min after intravenous administration compared

  4. The effect of age on mitochondrial ultrastructure.

    Science.gov (United States)

    Wilson, P D; Franks, L M

    1975-01-01

    The ultrastructure of perfused livers and of mitochondrial fractions from 6-month-old and 30-month-old C57/BL mice were studied. In old mice the liver cell mitochondria were enlarged and rounded with a light 'foamy', vacuolated matrix, short cristae and a loss of dense granules. Quantitative studies showed a 60% increase in the mean size and an increased proportion of larger mitochondria in intact 30-month-old perfused livers. Endothelial and Kupffer cell mitochondria were smaller than those of the parenchymal cells. Mitochondria in pellets prepared from 6- and 30-month-old livers were rounded and condensed, although there were a few larger and 'foamy' mitochondria in the preparations from old mice. Up to 47% of large mitochondria in the old livers were lost during cell fractionation.

  5. Lipoid proteinosis: clinical, histologic, and ultrastructural investigations.

    Science.gov (United States)

    Muda, A O; Paradisi, M; Angelo, C; Mostaccioli, S; Atzori, F; Puddu, P; Faraggiana, T

    1995-10-01

    The case of a 12-year-old boy with lipoid proteinosis is reported. Physical examination revealed long-standing varicella-like scars and areas of hyperpigmentation on the face and upper limbs with no evidence of photosensitivity, hoarseness, small papules along the free margins of eyelids, tongue firmness with short frenulum, and widespread papular lesions of the oral cavity. Histologic and ultrastructural examination revealed the characteristic skin changes: pink, hyaline-like, strongly periodic acid-Schiff-positive material in the dermis, surrounding blood vessels, and sweat glands; thin (30 to 35 nm) collagen fibrils interspersed in abundant amorphous material; blood vessels surrounded by thickened, multilayered basement membranes, in which layers of typical, homogeneous basement membrane material were alternating with electronlucent areas filled by various amounts of thin, cross-striated fibrils, arranged perpendicularly. These findings are of great interest since they show a complex relationship between type IV and type III-like collagen components.

  6. Ultrastructure and phylogeny of Ustilago coicis *

    Science.gov (United States)

    Zhang, Jing-ze; Guan, Pei-gang; Tao, Gang; Ojaghian, Mohammad Reza; Hyde, Kevin David

    2013-01-01

    Ustilago coicis causes serious smut on Coix lacryma-jobi in Dayang Town, Jinyun County, Zhejiang Province of China. In this paper, ultrastructural assessments on fungus-host interactions and teliospore development are presented, and molecular phylogenetic analyses have been done to elucidate the phylogenetic placement of the taxon. Hyphal growth within infected tissues was both intracellular and intercellular and on the surface of fungus-host interaction, and the fungal cell wall and the invaginated host plasma membrane were separated by a sheath comprising two distinct layers between the fungal cell wall and the invaginated host plasma membrane. Ornamentation development of teliospore walls was unique as they appeared to be originated from the exosporium. In addition, internal transcribed spacer (ITS) and large subunit (LSU) sequence data showed that U. coicis is closely related to Ustilago trichophora which infects grass species of the genus Echinochloa (Poaceae). PMID:23549851

  7. Ultrastructure and phylogeny of Ustilago coicis

    Institute of Scientific and Technical Information of China (English)

    Jing-ze ZHANG; Pei-gang GUAN; Gang TAO; Mohammad Reza OJAGHIAN; Kevin David HYDE

    2013-01-01

    Ustilago coicis causes serious smut on Coix lacryma-jobi in Dayang Town,Jinyun County,Zhejiang Province of China.In this paper,ultrastructural assessments on fungus-host interactions and teliospore development are presented,and molecular phylogenetic analyses have been done to elucidate the phylogenetic placement of the taxon.Hyphal growth within infected tissues was both intracellular and intercellular and on the surface of fungus-host interaction,and the fungal cell wall and the invaginated host plasma membrane were separated by a sheath comprising two distinct layers between the fungal cell wall and the invaginated host plasma membrane.Ornamentation development of teliospore walls was unique as they appeared to be originated from the exosporium.In addition,internal transcribed spacer (ITS) and large subunit (LSU) sequence data showed that U.coicis is closely related to Ustilago trichophora which infects grass species of the genus Echinochloa (Poaceae).

  8. Ultrastructure of spore development in Scutellospora heterogama.

    Science.gov (United States)

    Jeffries, Peter; Robinson-Boyer, Louisa; Rice, Paul; Newsam, Ray J; Dodd, John C

    2007-07-01

    The ultrastructural detail of spore development in Scutellospora heterogama is described. Although the main ontogenetic events are similar to those described from light microscopy, the complexity of wall layering is greater when examined at an ultrastructural level. The basic concept of a rigid spore wall enclosing two inner, flexible walls still holds true, but there are additional zones within these three walls distinguishable using electron microscopy, including an inner layer that is involved in the formation of the germination shield. The spore wall has three layers rather than the two reported previously. An outer, thin ornamented layer and an inner, thicker layer are both derived from the hyphal wall and present at all stages of development. These layers differentiate into the outer spore layer visible at the light microscope level. A third inner layer unique to the spore develops during spore swelling and rapidly expands before contracting back to form the second wall layer visible by light microscopy. The two inner flexible walls also are more complex than light microscopy suggests. The close association with the inner flexible walls with germination shield formation consolidates the preferred use of the term 'germinal walls' for these structures. A thin electron-dense layer separates the two germinal walls and is the region in which the germination shield forms. The inner germinal wall develops at least two sub-layers, one of which has an appearance similar to that of the expanding layer of the outer spore wall. An electron-dense layer is formed on the inner surface of the inner germinal wall as the germination shield develops, and this forms the wall surrounding the germination shield as well as the germination tube. At maturity, the outer germinal wall develops a thin, striate layer within its substructure.

  9. Ultrastructural changes in non-specific duodenitis

    Institute of Scientific and Technical Information of China (English)

    Cheng-Xin Wang; Li-Jiang Liu; Jing Guan; Xiao-Ling Zhao

    2005-01-01

    AIM: To investigate the ultrastructural and morphological changes of non-specific duodenitis (NSD) in an attempt to grade them according to the extent of the lesions.METHODS: Biopsies were taken from the mucosa of duodenal bulb of 44 patients selected from the patients undergoing upper gastrointestinal endoscopy for epigastric discomforts. From each patient, two pinch biopsies on the same area were obtained from duodenal bulb. One was for scanning electron microscopy and the other was stained with hematoxylin-eosin, Warthin-Starry silver and both were then examined under light microscope. A total of 12 specimens (three from each degree of the normal and Ⅰ-Ⅲ of NSD diagnosed and graded by histology) selected from the 44patients were dehydrated, critical point dried, coated with gold palladium and examined under a JEOL JSM-30 scanning electron microscope (SEM) at 20 kV.RESULTS: According to the ultrastructural morphologic changes, non-specific duodenitis was divided into normal (as control group), mild, moderate and severe degrees according to results of SEM. The normal villi of duodenal bulb were less than 0.2 mm. There were inflammation cells,occasionally red blood cells and macrophages on the mucosal epithelial surface. Erosion and desquamation of epithelium could be seen. Three cases (25%, 3/12) had gastric metaplasia and Helicobacter pylori(H pylori) infection could be found in 5 cases (41.67%, 5/12) in duodenal bulb mucosa. The most distinctive feature was the ulcer-like defect on the surface of epithelial cells.CONCLUSION: Non-specific duodenitis is a separate entity disease caused by different factors. SEM is of value as an aid in the diagnosis of mucosal diseases of duodenum.

  10. PLEKHA7 is an adherens junction protein with a tissue distribution and subcellular localization distinct from ZO-1 and E-cadherin.

    Directory of Open Access Journals (Sweden)

    Pamela Pulimeno

    Full Text Available The pleckstrin-homology-domain-containing protein PLEKHA7 was recently identified as a protein linking the E-cadherin-p120 ctn complex to the microtubule cytoskeleton. Here we characterize the expression, tissue distribution and subcellular localization of PLEKHA7 by immunoblotting, immunofluorescence microscopy, immunoelectron microscopy, and northern blotting in mammalian tissues. Anti-PLEKHA7 antibodies label the junctional regions of cultured kidney epithelial cells by immunofluorescence microscopy, and major polypeptides of M(r approximately 135 kDa and approximately 145 kDa by immunoblotting of lysates of cells and tissues. Two PLEKHA7 transcripts ( approximately 5.5 kb and approximately 6.5 kb are detected in epithelial tissues. PLEKHA7 is detected at epithelial junctions in sections of kidney, liver, pancreas, intestine, retina, and cornea, and its tissue distribution and subcellular localization are distinct from ZO-1. For example, PLEKHA7 is not detected within kidney glomeruli. Similarly to E-cadherin, p120 ctn, beta-catenin and alpha-catenin, PLEKHA7 is concentrated in the apical junctional belt, but unlike these adherens junction markers, and similarly to afadin, PLEKHA7 is not localized along the lateral region of polarized epithelial cells. Immunoelectron microscopy definitively establishes that PLEKHA7 is localized at the adherens junctions in colonic epithelial cells, at a mean distance of 28 nm from the plasma membrane. In summary, we show that PLEKHA7 is a cytoplasmic component of the epithelial adherens junction belt, with a subcellular localization and tissue distribution that is distinct from that of ZO-1 and most AJ proteins, and we provide the first description of its distribution and localization in several tissues.

  11. Ultrastructure of the Periplastidial Compartment of the Diatom Phaeodactylum tricornutum.

    Science.gov (United States)

    Flori, Serena; Jouneau, Pierre-Henri; Finazzi, Giovanni; Maréchal, Eric; Falconet, Denis

    2016-06-01

    Diatoms contain a secondary plastid that derives from a red algal symbiont. This organelle is limited by four membranes. The two outermost membranes are the chloroplast endoplasmic reticulum membrane (cERM), which is continuous with the host outer nuclear envelope, and the periplastidial membrane (PPM). The two innermost membranes correspond to the outer and inner envelope membranes (oEM and iEM) of the symbiont's chloroplast. Between the PPM and oEM lies a minimized symbiont cytoplasm, the periplastidial compartment (PPC). In Phaeodactylum tricornutum, PPC-resident proteins are localized in "blob-like-structures", which remain associated with plastids after cell disruption. We analyzed disrupted Phaeodactylum cells by focused ion beam scanning electron microscopy, revealing the presence of a vesicular network (VN) in the PPC, at a location consistent with blob-like structures. Presence of a VN in the PPC was confirmed in intact cells. Additionally, direct membrane contacts were observed between the PPM and nuclear inner envelope membrane at the level of the chloroplast-nucleus isthmus. This study provides insights into the PPC ultrastructure and opens perspectives on the function of this residual cytoplasm of red algal origin. Copyright © 2016 Elsevier GmbH. All rights reserved.

  12. [Multicentric reticulohistiocytosis: clinical and ultrastructural study of a case].

    Science.gov (United States)

    Peteiro, C; Fernández-Redondo, V; Zulaica, A; Caeiro, J L; Beiras, A; Toribio, J

    1987-01-01

    A case of multicentric reticulohistiocytosis associated with bilateral Dupuytren's disease and xanthelasmas of the eyelids is described. Ultrastructural examination showed electron-dense intracytoplasmic granules, collagen entrapment and interdigitation of adjacent cytoplasmic membranes.

  13. Ultrastructural characteristics of the synovial membrane in osteoarthritic temporomandibular joints

    NARCIS (Netherlands)

    Dijkgraaf, LC; Liem, RSB; deBont, LGM

    1997-01-01

    Purpose: This study analyzed the ultrastructural characteristics of the synovial membrane in various stages of osteoarthritis (OA) of the temporomandibular joint (TMJ), and developed a classification of this involvement based on these morphologic characteristics. Patients and Methods: Synovial membr

  14. Ultrastructural features of the benthic dinoflagellate Ostreopsis cf. ovata (Dinophyceae).

    Science.gov (United States)

    Escalera, Laura; Benvenuto, Giovanna; Scalco, Eleonora; Zingone, Adriana; Montresor, Marina

    2014-05-01

    The toxic benthic dinoflagellate Ostreopsis cf. ovata has considerably expanded its distribution range in the last decade, posing risks to human health. Several aspects of this species are still poorly known. We studied ultrastructural features of cultivated and natural populations of Ostreopsis cf. ovata from the Gulf of Naples (Mediterranean Sea) using confocal laser scanning, and scanning and transmission electron microscopy. New information on the morphology and location of several sulcal plates was gained and a new plate designation is suggested that better fits the one applied to other Gonyaulacales. The microtubular component of the cytoskeleton, revealed using an anti-β-tubulin antibody, consisted of a cortical layer of microtubules arranged asymmetrically in the episome and in the hyposome, complemented by a complex inner microtubular system running from the sulcal area towards the internal part of the cell. The conspicuous canal was delimited by two thick, burin-shaped lobes ending in a tubular ventral opening. The canal was surrounded by mucocysts discharging their content into it. A similar structure has been reported in other benthic and planktonic dinoflagellates and may be interpreted as an example of convergent evolution in species producing large amounts of mucus. Copyright © 2014 Elsevier GmbH. All rights reserved.

  15. SAR Image Despeckling Based on a Mixture of Gaussian Distributions with Local Parameters and Multiscale Edge Detection in Lapped Transform Domain

    Science.gov (United States)

    Hazarika, Deepika; Nath, Vijay Kumar; Bhuyan, Manbendra

    2016-12-01

    A new Lapped transform domain SAR image despeckling algorithm using a two-state Gaussian mixture probability density function that uses local parameters for the mixture model, is proposed. The use of lapped orthogonal transform (LOT) is motivated by its low computational complexity and robustness to oversmoothing. It is shown that the dyadic rearranged LOT coefficients of logarithmically transformed SAR images can be well approximated using two-state Gaussian mixture distribution compared to Laplacian, Gamma, generalized Gaussian and Cauchy distributions, based on the Kolmogorov-Smirnov (KS) goodness of fit test. The LOT coefficients of speckle noise are modeled using zero mean Gaussian distributions. A maximum a posteriori (MAP) estimator within Bayesian framework is developed using this proposed prior distribution and is used to restore the noisy LOT coefficients. The parameters of mixture distribution are estimated using the expectation-maximization algorithm. This paper presents a new technique to identify LOT modulus maxima which allows us to classify LOT coefficients into the edge and non edge coefficients. The classified edge coefficients are kept unmodified by the proposed algorithm whereas the noise-free estimates of non-edge coefficients are obtained using Bayesian MAP estimator developed using two state Gaussian mixture distribution with local parameters. Finally the proposed technique is combined with the cycle spinning scheme to further improve the despeckling performance. Experimental results show that the proposed method very efficiently reduces speckle in homogeneous regions while preserving more edge structures compared to some recent well known methods.

  16. Severe myalgia in familial Mediterranean fever: clinical and ultrastructural aspects.

    OpenAIRE

    Schapira, D; Ludatscher, R; Nahir, M.; M. Lorber; Scharf, Y.

    1988-01-01

    Severe myalgia is an uncommon feature of familial Mediterranean fever (FMF). A patient is presented in whom acute myalgia and high fever were the sole clinical findings during an FMF attack. The ultrastructural picture of the muscle tissue during the acute stage was characterised by a large deposition of collagen fibrils. The myalgia subsided during colchicine treatment. The clinical and ultrastructural features of myalgia in FMF are discussed in the light of the relevant literature.

  17. Detection and Localization of Transient Sources: Comparative Study of Complex-Lag Distribution Concept Versus Wavelets and Spectrogram-Based Methods

    Directory of Open Access Journals (Sweden)

    Bertrand Gottin

    2009-01-01

    Full Text Available The detection and localization of transient signals is nowadays a typical point of interest when we consider the multitude of existing transient sources, such as electrical and mechanical systems, underwater environments, audio domain, seismic data, and so forth. In such fields, transients carry out a lot of information. They can correspond to a large amount of phenomena issued from the studied problem and important to analyze (anomalies and perturbations, natural sources, environmental singularities, …. They usually occur randomly as brief and sudden signals, such as partial discharges in electrical cables and transformers tanks. Therefore, motivated by advanced and accurate analysis, efficient tools of transients detection and localization are of great utility. Higher order statistics, wavelets and spectrogram distributions are well known methods which proved their efficiency to detect and localize transients independently to one another. However, in the case of a signal composed by several transients physically related and with important energy gap between them, the tools previously mentioned could not detect efficiently all the transients of the whole signal. Recently, the generalized complex time distribution concept has been introduced. This distribution offers access to highly concentrated representation of any phase derivative order of a signal. In this paper, we use this improved phase analysis tool to define a new concept to detect and localize dependant transients taking regard to the phase break they cause and not their amplitude. ROC curves are calculated to analyze and compare the performances of the proposed methods.

  18. Regional Distribution Shifts Help Explain Local Changes in Wintering Raptor Abundance: Implications for Interpreting Population Trends: e86814

    National Research Council Canada - National Science Library

    Neil Paprocki; Julie A Heath; Stephen J Novak

    2014-01-01

    .... Recognizing the influence of distribution shifts on population indices will be an important part of interpreting trends within management units because current practice often assumes that changes...

  19. Microgranular acute promyelocytic leukemia: a distinct clinical, ultrastructural, and cytogenetic entity

    Energy Technology Data Exchange (ETDEWEB)

    Golomb, H.M.; Rowley, J.D.; Vardiman, J.W.; Testa, J.R.; Butler, A.

    1980-02-01

    Three patients with acute leukemia, disseminated intravaslar coagulation, and a specific acquired chromosome abnormality (t(15;17)) were found by transmission electron microscopy to have the typical distribution of granules seen in promyelocytes. However, the average granule sizes were 120, 170 and 180 nm, respectively, for the three patients, significantly less than the 250-nm resolution of light microscopy. We regard the leukemia in these three patients as comprising a distinct clinical, ultrastructural, and cytogenetic entity that we have chosen to all microgranular acute promyelocytic leukemia.

  20. Ultrastructural studies on the sporogenous tissue and anther wall of Leucojum aestivum (amaryllidaceae) in different developmental stages.

    Science.gov (United States)

    Ekici, Nuran; Dane, Feruzan

    2012-12-01

    In this study, ultrastructures of anther wall and sporogenous tissue of Leucojum aestivum were investigated during different developmental stages. Cytomictic channels were seen between pollen mother cells during prophase I. Polar distribution was described in the organelle content of pollen mother cells and microspores in early phases of microsporogenesis and also in pollen mitosis. Active secretion was observed in tapetal cells. Previous reports about developmental stages of male gametophyte were compared with the results of this study.

  1. Modelling local distribution of an Arctic dwarf shrub indicates an important role for remote sensing of snow cover

    NARCIS (Netherlands)

    Beck, PSA; Kalmbach, E; Joly, D; Stien, A; Nilsen, L

    2005-01-01

    Despite the intensive research effort directed at predicting the effects of climate change on plants in the Arctic, the impact of environmental change on species' distributions remains difficult to quantify. Predictive habitat distribution models provide a tool to predict the geographical distributi

  2. Modelling local distribution of an Arctic dwarf shrub indicates an important role for remote sensing of snow cover

    NARCIS (Netherlands)

    Beck, PSA; Kalmbach, E; Joly, D; Stien, A; Nilsen, L

    2005-01-01

    Despite the intensive research effort directed at predicting the effects of climate change on plants in the Arctic, the impact of environmental change on species' distributions remains difficult to quantify. Predictive habitat distribution models provide a tool to predict the geographical

  3. Ultra-structural hair alterations in Friedreich's ataxia: A scanning electron microscopic investigation.

    Science.gov (United States)

    Turkmenoglu, F Pinar; Kasirga, U Baran; Celik, H Hamdi

    2015-08-01

    Friedreich's ataxia (FRDA) is an autosomal recessive inherited disorder involving progressive damage to the central and peripheral nervous systems and cardiomyopathy. FRDA is caused by the silencing of the FXN gene and reduced levels of the encoded protein, frataxin. Frataxin is a mitochondrial protein that functions primarily in iron-sulfur cluster synthesis. Skin disorders including hair abnormalities have previously been reported in patients with mitochondrial disorders. However, to our knowledge, ultra-structural hair alterations in FRDA were not demonstrated. The purpose of this study was to determine ultra-structural alterations in the hairs of FRDA patients as well as carriers. Hair specimen from four patients, who are in different stages of the disease, and two carriers were examined by scanning electron microscope. Thin and weak hair follicles with absence of homogeneities on the cuticular surface, local damages of the cuticular layer, cuticular fractures were detected in both carriers and patients, but these alterations were much more prominent in the hair follicles of patients. In addition, erosions on the surface of the cuticle and local deep cavities just under the cuticular level were observed only in patients. Indistinct cuticular pattern, pores on the cuticular surface, and presence of concavities on the hair follicle were also detected in patients in later stages of the disease. According to our results, progression of the disease increased the alterations on hair structure. We suggest that ultra-structural alterations observed in hair samples might be due to oxidative stress caused by deficient frataxin expression in mitochondria. © 2015 Wiley Periodicals, Inc.

  4. Effect of the irradiance distribution from light curing units on the local micro-hardness of the surface of dental resins.

    Science.gov (United States)

    Haenel, Thomas; Hausnerová, Berenika; Steinhaus, Johannes; Price, Richard B T; Sullivan, Braden; Moeginger, Bernhard

    2015-02-01

    An inhomogeneous irradiance distribution from a light-curing unit (LCU) can locally cause inhomogeneous curing with locally inadequately cured and/or over-cured areas causing e.g. monomer elution or internal shrinkage stresses, and thus reduce the lifetime of dental resin based composite (RBC) restorations. The aim of the study is to determine both the irradiance distribution of two light curing units (LCUs) and its influence on the local mechanical properties of a RBC. Specimens of Arabesk TOP OA2 were irradiated for 5, 20, and 80s using a Bluephase® 20i LCU in the Low mode (666mW/cm(2)), in the Turbo mode (2222mW/cm(2)) and a Celalux® 2 (1264mW/cm(2)). The degree of conversion (DC) was determined with an ATR-FTIR. The Knoop micro-hardness (average of five specimens) was measured on the specimen surface after 24h of dark and dry storage at room temperature. The irradiance distribution affected the hardness distribution across the surface of the specimens. The hardness distribution corresponded well to the inhomogeneous irradiance distributions of the LCU. The highest reaction rates occurred after approximately 2s light exposure. A DC of 40% was reached after 3.6 or 5.7s, depending on the LCU. The inhomogeneous hardness distribution was still evident after 80s of light exposure. The irradiance distribution from a LCU is reflected in the hardness distribution across the surface. Irradiance level of the LCU and light exposure time do not affect the pattern of the hardness distribution--only the hardness level. In areas of low irradiation this may result in inadequate resin polymerization, poor physical properties, and hence premature failure of the restorations as they are usually much smaller than the investigated specimens. It has to be stressed that inhomogeneous does not necessarily mean poor if in all areas of the restoration enough light intensity is introduced to achieve a high degree of cure. Copyright © 2014 Academy of Dental Materials. Published by

  5. Influence of regional and local topography on the distribution of polymetallic nodules in Central Indian Ocean Basin

    Digital Repository Service at National Institute of Oceanography (India)

    Kodagali, V.N.

    Detailed bathymetric surveys from part of the Central Indian Ocean revealed several bathymetric features such as hills, slopes, valleys, and plains. Areas with a local relief of a few to hundreds of meters generally have a high abundance...

  6. Numerical renormalization group study of probability distributions for local fluctuations in the Anderson-Holstein and Holstein-Hubbard models.

    Science.gov (United States)

    Hewson, Alex C; Bauer, Johannes

    2010-03-24

    We show that information on the probability density of local fluctuations can be obtained from a numerical renormalization group calculation of a reduced density matrix. We apply this approach to the Anderson-Holstein impurity model to calculate the ground state probability density ρ(x) for the displacement x of the local oscillator. From this density we can deduce an effective local potential for the oscillator and compare its form with that obtained from a semiclassical approximation as a function of the coupling strength. The method is extended to the infinite dimensional Holstein-Hubbard model using dynamical mean field theory. We use this approach to compare the probability densities for the displacement of the local oscillator in the normal, antiferromagnetic and charge ordered phases.

  7. Development of a rapid matrix digestion technique for ultrastructural analysis of elastic fibers in the intervertebral disc.

    Science.gov (United States)

    Tavakoli, Javad; Costi, John J

    2017-07-01

    Collagen and elastic fibers are two major fibrous constituents of the annulus fibrosus (AF) in the disc that contribute to its mechanical and viscoelastic properties. It was thought that elastic fibers play no substantial role in the function and properties of the disc as these fibers were irregularly distributed. Studies that have revealed highly organized elastic fibers with different regional orientation and distribution, while being strongly crosslinked with matrix, suggesting their contribution to disc structure-function properties. These studies that were performed by light microscopic analysis of histologically prepared samples, have not been able to reveal the fine-scale architectural details of the elastic fiber network. Since elastic fibers are intermingled with other fibrous components of the disc and mostly obscured by the extracellular matrix, it is difficult to demonstrate their ultra-structural organization using scanning electron microscopy (SEM). Therefore the aim of this study was to develop a rapid matrix digestion technique for ultrastructural analysis of the disc elastic fibers. This study provides a new method for fundamental visualization of elastic fibers and their architecture in the disc. Through the ultra-structural analysis, the relationship between structure and function, as well as the role of elastic fibers on AF mechanical properties can be studied. This method may be used to develop a three-dimensional map of elastic fibers distribution within the disc, which would provide valuable information for designing tissue engineered scaffolds for AF repair and replacement. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Characterizing and reducing equifinality by constraining a distributed catchment model with regional signatures, local observations, and process understanding

    Science.gov (United States)

    Kelleher, Christa; McGlynn, Brian; Wagener, Thorsten

    2017-07-01

    Distributed catchment models are widely used tools for predicting hydrologic behavior. While distributed models require many parameters to describe a system, they are expected to simulate behavior that is more consistent with observed processes. However, obtaining a single set of acceptable parameters can be problematic, as parameter equifinality often results in several behavioral sets that fit observations (typically streamflow). In this study, we investigate the extent to which equifinality impacts a typical distributed modeling application. We outline a hierarchical approach to reduce the number of behavioral sets based on regional, observation-driven, and expert-knowledge-based constraints. For our application, we explore how each of these constraint classes reduced the number of behavioral parameter sets and altered distributions of spatiotemporal simulations, simulating a well-studied headwater catchment, Stringer Creek, Montana, using the distributed hydrology-soil-vegetation model (DHSVM). As a demonstrative exercise, we investigated model performance across 10 000 parameter sets. Constraints on regional signatures, the hydrograph, and two internal measurements of snow water equivalent time series reduced the number of behavioral parameter sets but still left a small number with similar goodness of fit. This subset was ultimately further reduced by incorporating pattern expectations of groundwater table depth across the catchment. Our results suggest that utilizing a hierarchical approach based on regional datasets, observations, and expert knowledge to identify behavioral parameter sets can reduce equifinality and bolster more careful application and simulation of spatiotemporal processes via distributed modeling at the catchment scale.

  9. Food restriction modifies ultrastructure of hippocampal synapses.

    Science.gov (United States)

    Babits, Réka; Szőke, Balázs; Sótonyi, Péter; Rácz, Bence

    2016-04-01

    Consumption of high-energy diets may compromise health and may also impair cognition; these impairments have been linked to tasks that require hippocampal function. Conversely, food restriction has been shown to improve certain aspects of hippocampal function, including spatial memory and memory persistence. These diet-dependent functional changes raise the possibility that the synaptic structure underlying hippocampal function is also affected. To examine how short-term food restriction (FR) alters the synaptic structure of the hippocampus, we used quantitative electron microscopy to analyze the organization of neuropil in the CA1 stratum radiatum of the hippocampus in young rats, consequent to reduced food. While four weeks of FR did not modify the density, size, or shape of postsynaptic spines, the synapses established by these spines were altered, displaying increased mean length, and more frequent perforations of postsynaptic densities. That the number of perforated synapses (believed to be an indicator of synaptic enhancement) increased, and that the CA1 spine population had on average significantly longer PSDs suggests that synaptic efficacy of axospinous synapses also increased in the CA1. Taken together, our ultrastructural data reveal previously unrecognized structural changes at hippocampal synapses as a function of food restriction, supporting a link between metabolic balance and synaptic plasticity.

  10. Ultrastructural Characterization of Zika Virus Replication Factories

    Directory of Open Access Journals (Sweden)

    Mirko Cortese

    2017-02-01

    Full Text Available A global concern has emerged with the pandemic spread of Zika virus (ZIKV infections that can cause severe neurological symptoms in adults and newborns. ZIKV is a positive-strand RNA virus replicating in virus-induced membranous replication factories (RFs. Here we used various imaging techniques to investigate the ultrastructural details of ZIKV RFs and their relationship with host cell organelles. Analyses of human hepatic cells and neural progenitor cells infected with ZIKV revealed endoplasmic reticulum (ER membrane invaginations containing pore-like openings toward the cytosol, reminiscent to RFs in Dengue virus-infected cells. Both the MR766 African strain and the H/PF/2013 Asian strain, the latter linked to neurological diseases, induce RFs of similar architecture. Importantly, ZIKV infection causes a drastic reorganization of microtubules and intermediate filaments forming cage-like structures surrounding the viral RF. Consistently, ZIKV replication is suppressed by cytoskeleton-targeting drugs. Thus, ZIKV RFs are tightly linked to rearrangements of the host cell cytoskeleton.

  11. Functional ultrastructure of the plant nucleolus.

    Science.gov (United States)

    Stępiński, Dariusz

    2014-11-01

    Nucleoli are nuclear domains present in almost all eukaryotic cells. They not only specialize in the production of ribosomal subunits but also play roles in many fundamental cellular activities. Concerning ribosome biosynthesis, particular stages of this process, i.e., ribosomal DNA transcription, primary RNA transcript processing, and ribosome assembly proceed in precisely defined nucleolar subdomains. Although eukaryotic nucleoli are conservative in respect of their main function, clear morphological differences between these structures can be noticed between individual kingdoms. In most cases, a plant nucleolus shows well-ordered structure in which four main ultrastructural components can be distinguished: fibrillar centers, dense fibrillar component, granular component, and nucleolar vacuoles. Nucleolar chromatin is an additional crucial structural component of this organelle. Nucleolonema, although it is not always an unequivocally distinguished nucleolar domain, has often been described as a well-grounded morphological element, especially of plant nucleoli. The ratios and morphology of particular subcompartments of a nucleolus can change depending on its metabolic activity which in turn is correlated with the physiological state of a cell, cell type, cell cycle phase, as well as with environmental influence. Precise attribution of functions to particular nucleolar subregions in the process of ribosome biosynthesis is now possible using various approaches. The presented description of plant nucleolar morphology summarizes previous knowledge regarding the function of nucleoli as well as of their particular subdomains not only in the course of ribosome biosynthesis.

  12. Ultrastructural morphogenesis of salmonid alphavirus 1.

    Science.gov (United States)

    Herath, T K; Ferguson, H W; Thompson, K D; Adams, A; Richards, R H

    2012-11-01

    Studies on the ultrastructural morphogenesis of viruses give an insight into how the host cell mechanisms are utilized for new virion synthesis. A time course examining salmonid alphavirus 1 (SAV 1) assembly was performed by culturing the virus on Chinook salmon embryo cells (CHSE-214). Different stages of viral replication were observed under electron microscopy. Virus-like particles were observed inside membrane-bound vesicles as early as 1 h following contact of the virus with the cells. Membrane-dependent replication complexes were observed in the cytoplasm of the cells, with spherules found at the periphery of late endosome-like vacuoles. The use of intracellular membranes for RNA replication is similar to other positive-sense single-stranded RNA (+ssRNA) viruses. The number of Golgi apparatus and associated vacuoles characterized by 'fuzzy'-coated membranes was greater in virus-infected cells. The mature enveloped virions started to bud out from the cells at approximately 24 h post-infection. These observations suggest that the pathway used by SAV 1 for the generation of new virus particles in vitro is comparable to viral replication observed with mammalian alphaviruses but with some interesting differences.

  13. Effect of androgen deprivation on penile ultrastructure

    Institute of Scientific and Technical Information of China (English)

    Zhou-JunSHEN; Xie-LaiZHOU; Ying-LiLU; Zhao-DianCHEN

    2003-01-01

    Aim:To investigate the ultrastructural changes of penile corpus cavernosum and tunica albuginea in rats treated with castration or finasteride.Methods:Eighteen male Sprague-Dawley rats of nine weeks old were randomly divided into three groups with 6 rats each,Group A served as the control,Group B was castrated and Group C,treated with finasteride,Four weeks later,rats were anesthetized and blood samples obtained for the determination of serum testosterone(T)and dihydrotestosterone(DHT) levels;penile tissues were taken for scanning electron microscopy.Results:The T,free T and DHT levels in Group B and the DHT level in Group C were significantly lower than those in Group A(P0.05).Elastic fibers in the tunica albuginea of Group A were very rich and arranged regularly and undulatedly,but in Group B,most of the elastic fibers were replaced by collagenous fibers.In Group C,the tunica albuginea was mainly composed of thick and irregular-arranged collagenous fibers.In Group A,there were abundant smooth muscle fibers in the trabeculae of corpus cavernosum,but they were much less in Group C and scarce or even disappeared in Group B.In Groups B and C,the diminished/disappeared smooth muscle fibers were replaced by irregularly arranged collagenous fibers.Conclusion:In rats,androgen is essential for maintaining the normal structure of penile tunica albuginea and corpus carvenosum.

  14. Spermatozoon ultrastructure in two monorchiid digeneans

    Directory of Open Access Journals (Sweden)

    Yann Quilichini

    2016-09-01

    Full Text Available Spermatological characteristics of species from two monorchiid genera, Opisthomonorchis and Paramonorcheides, have been investigated, for the first time, by means of transmission electron microscopy. The ultrastructural study reveals that the mature spermatozoon of Opisthomonorchis dinema and Paramonorcheides selaris share several characters such as the presence of two axonemes of different lengths showing the 9+“1” pattern of the Trepaxonemata, a nucleus, two mitochondria, two bundles of parallel cortical microtubules, external ornamentation of the plasma membrane, spine-like bodies, granules of glycogen and similar morphologies of the anterior and posterior extremities. The slight differences between the male gamete of O. dinema and P. selaris are the length of the first axoneme and the position of the second mitochondrion. This study also elucidates the general morphology of the spermatozoon in all monorchiid species described so far, which corresponds to a unique spermatozoon type. Other interesting finds concern the spermatological similarities between monorchiid spermatozoa and the mature spermatozoon reported in the apocreadiid Neoapocreadium chabaudi. These similarities allow us to suggest a close phylogenetical relationship between the Monorchiidae and the Apocreadiidae, although more studies are needed, especially in the unexplored taxa.

  15. Do poorer people have poorer access to local resources and facilities? The distribution of local resources by area deprivation in Glasgow, Scotland.

    Science.gov (United States)

    Macintyre, Sally; Macdonald, Laura; Ellaway, Anne

    2008-09-01

    It has commonly been suggested that in modern cities individual or household deprivation (for example, low income or education) is amplified by area level deprivation (for example, lack of jobs or good schools), in ways which damage the health of the poorest and increase health inequalities. The aim of this study was to determine the location of a range of resources and exposures by deprivation in a UK city. We examined the location of 42 resources in Glasgow City, Scotland, in 2005-2006, by quintile of small area deprivation. Measures included number per 1000 population, network distance to nearest resource, and percentage of data zones containing at least one of each type of resource. Twelve resources had higher density in, and/or were closer to or more common in, more deprived neighbourhoods: public nurseries, public primary schools, police stations, pharmacies, credit unions, post offices, bus stops, bingo halls, public swimming pools, public sports centres, outdoor play areas, and vacant and derelict land/buildings. Sixteen had higher density in, and/or were closer to, or more common in, more affluent neighbourhoods: public secondary schools, private schools, banks, building societies, museums/art galleries, railway stations, subway stations, tennis courts, bowling greens, private health clubs, private swimming pools, colleges, A & E hospitals, parks, waste disposal sites, and tourist attractions. Private nurseries, Universities, fire stations, general, dental and ophthalmic practices, pawn brokers, ATMs, supermarkets, fast food chains, cafes, public libraries, golf courses, and cinemas showed no clear pattern by deprivation. Thus it appears that in the early 21st century access to resources does not always disadvantage poorer neighbourhoods in the UK. We conclude that we need to ensure that theories and policies are based on up-to-date and context-specific empirical evidence on the distribution of neighbourhood resources, and to engage in further research on

  16. Study on sustainable redevelopment of a densely built-up area in Tokyo by introducing a distributed local energy supply system

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Hong; Ooka, Ryozo; Huang, Hong [Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505 (Japan); Iwamura, Kazuo [Musashi Institute of Technology, UIA, JIA, Tokyo (Japan); Yoshizawa, Nobufusa; Miisho, Kiyoshi [IWAMURA Atelier Co. Ltd., Tokyo (Japan); Yoshida, Satoshi [Yokohama National University, Yokohama (Japan); Namatame, Sanae; Sakakura, Atsushi; Tanaka, Syunichi [Tokyo Gas Co. Ltd., Tokyo (Japan)

    2008-07-01

    'Distributed local energy systems' had been expected to rationalize the supply of energy to built-up areas, but until now very little research has been performed to estimate the effect of their application to actual cities. In this research, therefore, a future vision for the year 2030 in the Sancha Area (SANCHA VISION 2030), a typical densely built-up area in Tokyo, has been elaborated including a simulation to estimate benefits from the application of distributed energy systems in terms of reduced energy consumption and CO{sub 2} emissions as well as mitigation of the heat-island phenomenon. As a result, it was demonstrated that a 'distributed local energy system', which provides a district with both electrical power and heat through an integrated distribution system, may contribute to a considerable improvement in energy efficiency for those areas. In addition, it may also provide other benefits, including enhancement of living amenity and urban security in times of emergency. (author)

  17. Comparison between the localized power loss and flux distribution in a three phase distribution transformer 100 kVA assembled from various type of T-joint geometry with staggered yoke

    Energy Technology Data Exchange (ETDEWEB)

    Daut, I.; Ahmad, D.M.M.; Taib, S. [Univ. of Malaysia at Perlis (Malaysia). School of Electrical System Engineering

    2008-07-01

    The efficient operation of power transformer cores depends to a large degree on the design of the joints between their limbs and yokes. This study compared the performances of cores with different T-joint geometries. The cores were all built from identical grades of electrical steel, notably M5. In particular, the study investigated the variation of localized power loss and flux distribution in 3-phase transformer cores of 100 kVA. All the mesh graphs of the localized power loss from the transformer cores were measured using an iron loss tester at all four types of T-joints. The flux distribution was calculated using a computational method. The localized power loss was lower at the outer edge of the T-joint, and higher at the inner edge of the T- joint. Study results revealed that the localized power loss at transformer cores assembled with a 60 degree T-joint was less than with other types. As such, the core assembled with a 60 degree T-joint is more efficient than other T-joints. The flux lines showed that the flux penetration into the centre limb of transformer core is an important factor affecting the performance of the transformer core. 5 refs., 2 figs.

  18. Measurement of oil volume fraction and velocity distributions in vertical oil-in-water flows using ERT and a local probe

    Institute of Scientific and Technical Information of China (English)

    LI Hua; WANG Mi; WU Ying-xiang; MA Yi-xin; WILLIAMS Richard

    2005-01-01

    This paper presents the use of a high performance dual-plane electrical resistance tomography (ERT) system and a local dual-sensor conductance probe to measure the vertical upward oil-in-water pipe flows in which the mean oil volume fraction is up to 23.1%.A sensitivity coefficient back-projection (SBP) algorithm was adopted to reconstruct the flow distributions and a cross correlation method was applied to obtain the oil velocity distributions. The oil volume fraction and velocity distributions obtained from both measurement techniques were compared and good agreement was found, which indicates that the ERT technique can be used to measure the low fraction oil-water flows. Finally, the factors affecting measurement precision were discussed.

  19. Targeted disruption of the mouse Csrp2 gene encoding the cysteine- and glycine-rich LIM domain protein CRP2 result in subtle alteration of cardiac ultrastructure

    Directory of Open Access Journals (Sweden)

    Stoll Doris

    2008-08-01

    Full Text Available Abstract Background The cysteine and glycine rich protein 2 (CRP2 encoded by the Csrp2 gene is a LIM domain protein expressed in the vascular system, particularly in smooth muscle cells. It exhibits a bimodal subcellular distribution, accumulating at actin-based filaments in the cytosol and in the nucleus. In order to analyze the function of CRP2 in vivo, we disrupted the Csrp2 gene in mice and analysed the resulting phenotype. Results A ~17.3 kbp fragment of the murine Csrp2 gene containing exon 3 through 6 was isolated. Using this construct we confirmed the recently determined chromosomal localization (Chromosome 10, best fit location between markers D10Mit203 proximal and D10Mit150 central. A gene disruption cassette was cloned into exon 4 and a mouse strain lacking functional Csrp2 was generated. Mice lacking CRP2 are viable and fertile and have no obvious deficits in reproduction and survival. However, detailed histological and electron microscopic studies reveal that CRP2-deficient mice have subtle alterations in their cardiac ultrastructure. In these mice, the cardiomyocytes display a slight increase in their thickness, indicating moderate hypertrophy at the cellular level. Although the expression of several intercalated disc-associated proteins such as β-catenin, N-RAP and connexin-43 were not affected in these mice, the distribution of respective proteins was changed within heart tissue. Conclusion We conclude that the lack of CRP2 is associated with alterations in cardiomyocyte thickness and hypertrophy.

  20. Have the tsunami and nuclear accident following the Great East Japan Earthquake affected the local distribution of hospital physicians?

    Science.gov (United States)

    Kashima, Saori; Inoue, Kazuo; Matsumoto, Masatoshi

    2017-01-01

    The Great East Japan Earthquake occurred on 11 March 2011 near the northeast coast of the main island, 'Honshu', of Japan. It wreaked enormous damage in two main ways: a giant tsunami and an accident at the Fukushima Daiichi Nuclear Power Plant (FDNPP). This disaster may have affected the distribution of physicians in the region. Here, we evaluate the effect of the disaster on the distribution of hospital physicians in the three most severely affected prefectures (Iwate, Miyagi, and Fukushima). We obtained individual information about physicians from the Physician Census in 2010 (pre-disaster) and 2012 (post-disaster). We examined geographical distributions of physicians in two ways: (1) municipality-based analysis for demographic evaluation; and (2) hospital-based analysis for geographic evaluation. In each analysis, we calculated the rate of change in physician distributions between pre- and post-disaster years at various distances from the tsunami-affected coast, and from the restricted area due to the FDNPP accident. The change in all, hospital, and clinic physicians were 0.2%, 0.7%, and -0.7%, respectively. In the municipality-based analysis, after taking account of the decreased population, physician numbers only decreased within the restricted area. In the hospital-based analysis, hospital physician numbers did not decrease at any distance from the tsunami-affected coast. In contrast, there was a 3.3% and 2.3% decrease in hospital physicians 0-25 km and 25-50 km from the restricted area surrounding the FDNPP, respectively. Additionally, decreases were larger and increases were smaller in areas close to the FDNPP than in areas further away. Our results suggest that the tsunami did not affect the distribution of physicians in the affected regions. However, the FDNPP accident changed physician distribution in areas close to the power plant.

  1. Overview of Marketing and Distribution. The Wisconsin Guide to Local Curriculum Improvement in Industrial Education, K-12.

    Science.gov (United States)

    Ritz, John M.

    The intent of this field tested instructional package is to familiarize the student with the marketing and distribution element of industry and its function in the production of goods and services. Defining behavioral objectives, the course description offers a media guide, suggested classroom activities, and sample student evaluation forms as…

  2. CCDC65 mutation causes primary ciliary dyskinesia with normal ultrastructure and hyperkinetic cilia.

    Directory of Open Access Journals (Sweden)

    Amjad Horani

    Full Text Available BACKGROUND: Primary ciliary dyskinesia (PCD is a genetic disorder characterized by impaired ciliary function, leading to chronic sinopulmonary disease. The genetic causes of PCD are still evolving, while the diagnosis is often dependent on finding a ciliary ultrastructural abnormality and immotile cilia. Here we report a novel gene associated with PCD but without ciliary ultrastructural abnormalities evident by transmission electron microscopy, but with dyskinetic cilia beating. METHODS: Genetic linkage analysis was performed in a family with a PCD subject. Gene expression was studied in Chlamydomonas reinhardtii and human airway epithelial cells, using RNA assays and immunostaining. The phenotypic effects of candidate gene mutations were determined in primary culture human tracheobronchial epithelial cells transduced with gene targeted shRNA sequences. Video-microscopy was used to evaluate cilia motion. RESULTS: A single novel mutation in CCDC65, which created a termination codon at position 293, was identified in a subject with typical clinical features of PCD. CCDC65, an orthologue of the Chlamydomonas nexin-dynein regulatory complex protein DRC2, was localized to the cilia of normal nasal epithelial cells but was absent in those from the proband. CCDC65 expression was up-regulated during ciliogenesis in cultured airway epithelial cells, as was DRC2 in C. reinhardtii following deflagellation. Nasal epithelial cells from the affected individual and CCDC65-specific shRNA transduced normal airway epithelial cells had stiff and dyskinetic cilia beating patterns compared to control cells. Moreover, Gas8, a nexin-dynein regulatory complex component previously identified to associate with CCDC65, was absent in airway cells from the PCD subject and CCDC65-silenced cells. CONCLUSION: Mutation in CCDC65, a nexin-dynein regulatory complex member, resulted in a frameshift mutation and PCD. The affected individual had altered cilia beating patterns, and

  3. Ultrastructural Changes in the Ileum of White BALB/C Mice Experimentally Infected with Salmonella hadar

    Directory of Open Access Journals (Sweden)

    Afaf A. Yousif

    2010-01-01

    Full Text Available Problem statement: Recently, Salmonella hadar has been isolated and identified from goat in Iraq. The purpose of the present study was to investigate the ultrastructural changes in the ileum epithelial cells of mice experimentally infected with Salmonella hadar. Approach: The white BALB/c mice inoculated orally with Salmonella enterica serovar hadar strain and their ileums were examined by transmission electron microscopy at 24, 48, 72, 96 and 120 h after inoculation. Results: The challenge organism appeared adhered to the mucosal microvilli of the ileum from 24 h postinoculation. The early ultrastructural changes characterized by local derangement with slight swelling of the proximal ends of the microvilli. In addition, there was ruffling of the apical cell surfaces of the microvilli with cytoplasmic vacuolization of enterocytes due to invading by the organisms. The Challenge organism was usually intact and enclosed by a membrane. The damage of the epithelial cells started as a minor lesion at 24 h and became severe after 48, 72 and 96 h post infection. The more severe ultrastructural changes in the ileum occurred at 120 h post infection, which revealed hypertrophy of goblet cell, dilatation of endoplasmic reticulum, severe cytoplasmic vacuolization, thickening of the nuclear membrane and several Salmonella Containing Vacuoles (SCV. Conclusion: Our results revealed that the cellular invasion by Salmonella hadar may occurred early than 24 h because of the obvious alterations seen in the cells of the ileum at this time of infection. In addition, the continuation of cellular pathological changes for 120 h post infection may refers that S. hadar has some mechanisms which aid it to survive and replicate within intestinal cells. We recommend further studies with early observation periods in order to determine the invasion time.

  4. [Asteroid hyalopathy. Ultrastructural study of 3 cases].

    Science.gov (United States)

    Adenis, J P; Leboutet, M J; Loubet, R

    1984-01-01

    The vitreous of three patients with asteroïd hyalosis (average age: 57 years) was obtained by a two-hand closed pars plana vitrectomy. Asteroïd hyalosis was associated with alcoholic neuropathy in the first case, long standing retinal detachment in the second case, and diabetes mellitus in the third case. The visual acuity before and after the surgical procedure improved from 1.2/6 to 6/6 in the first case, from light perception to 0.3/6 in the second case, from 0.6/6 to 4.8/6 in the third case. The vitreous was studied by different ultrastructural technics : transmission electron microscopy (T.E.M.) scanning electron microscopy (S.E.M.) and electron diffraction X ray analysis (E.D.A.X.). By S.E.M. the asteroïd bodies appeared as rounded structures with an irregular surface connected to each other by fibrous strands among sodium chloride crystals. No cellular remnants were observed. By T.E.M. the asteroïd bodies were composed of interwinned ribbons of multilaminar membranes with a periodicity (10 to 60 A) characteristic of complex lipids, especially phospholipids. At the edge of the ribbons there were dots and sometimes clumps of opaque material that tended to crack out of the specimen with the heat of the electron beam. T.E.M. study disclosed the irregular disposition of the calcific bodies. By E.D.A.X. the calcific composition of the rounded structures could be determined : calcium and phosphorus were the main elements detectable in asteroïd bodies of all sizes for all three patients. The average calcium counts for the three successive cases were : 18, 30, 43 and for phosphorus : 9, 14, 26. Potassium was found in the first case, and sulfur in the third case.(ABSTRACT TRUNCATED AT 250 WORDS)

  5. Ultrastructure and morphogenesis of human immunodeficiency virus.

    Science.gov (United States)

    Nakai, M; Goto, T

    1996-08-01

    The ultrastructure and morphogenesis of human immunodeficiency virus (HIV) were elucidated by observation with several techniques including immunoelectron microscopy and cryo-microscopy. The virus particle consists of an envelope, a core and matrix. The virus particles were observed extracellularly as having one of three profiles: (1) a centric or an eccentric electron-dense core, (2) rod-shaped electron-dense core, and (3) doughnut-shaped. HIV-1 particles in the hydrated state were observed by high resolution electron cryo-microscopy to be globular, and the lipid membrane was clearly resolved as a bilayer. Many projections around the circumference were seen to be knob-like. The shapes and sizes of the projections, especially head parts, were found to vary in each projection. By isolation with Nonidet P40 and glutaraldehyde, HIV-1 cores were confirmed to consist of p24 protein by immunogold labeling. When the virus enters the cell, two entry modes were found: membrane fusion and endocytosis. No structures resembling virus particles could be seen in the cytoplasm after viral entry. In HIV-1-infected cells, positive reactions by immuno-labeling suggest that HIV-1 Gag may be produced in membrane-bound structures and transported to the cell surface by cytoskeletons. Then a crescent electron-dense layer was first formed underneath the cell membrane. Finally, the virus particle was released from the cell surface. Several cell clones producing defective particles were isolated from MT-4/HIV-1 cells. Among them, doughnut-shaped or teardrop-shaped particles were seen to be produced in the extracellular space. In the doughnut-shaped particles, Gag p17 and p24 proteins faced each other against the inner electron dense ring, suggesting that the inner ring consists of a precursor Gag protein.

  6. Spermatogenesis and sperm ultrastructure in the polychaete genus Ophryotrocha (Dorvilleidae)

    Science.gov (United States)

    Pfannenstiel, Hans-Dieter; Grünig, Charlotte

    1990-06-01

    The details of spermatogenesis and spermiogenesis are described for Ophryotrocha puerilis. The ultrastructure of mature sperm is shown for O. puerilis, O. hartmanni, O. gracilis, O. diadema, O. labronica, and O. notoglandulata. Clusters of sixteen cells each are proliferated by two stem cells in each setigerous segment of O. puerilis representing the very early stages of both oogenesis and spermatogenesis. In each spermatocyte-I cluster, the cells are interconnected by cytoplasmic bridges. Early, clusters are enveloped by peritoneal sheath cells. These transient gonad walls break down prior to meiosis. The meiotic processes may start in the clusters with the cells still interconnected, or during breakdown of the original cluster, giving rise to smaller subclusters of both spermatocytes I and spermatocytes II with various numbers of cells. Finally, spermatid tetrads are present. As spermiogenesis progresses, the tetrads disintegrate. Golgi vesicles in both spermatocytes and spermatids contain electron-dense material, presumably preacrosomal. The acrosome is formed by such vesicles. In the six species studied here, the acrosomes appear to be of a similar overall structure but are of different shape. Centrioles are usually located beneath the acrosome. The distal centriole forms the basal body of a flagellum-like cytoplasmic process. The microtubules of these flagellar equivalents do not show a normal ciliar arrangement. The flagellar equivalent appears to be non-motile. In O. hartmanni and in O. notoglandulata, a flagellar equivalent is missing. Microtubules originating from the proximal end of the distal centriole stretch to the nuclear envelope. This feature appears to be especially conspicuous in O. puerilis and in O. labronica. In O. labronica and in O. notoglandulata, bundles of microtubules paralleling the cell perimeter appear to stabilise the sperm. Various numbers of mitochondria are either randomly distributed around the nucleus or accumulate on one side

  7. Ultrastructural alterations of the hepatopancreas in Porcellio scaber under stress.

    Science.gov (United States)

    Znidaršič, Nada; Strus, Jasna; Drobne, Damjana

    2003-04-01

    Cellular ultrastructure varies in accordance with physiological processes, also reflecting responses to environmental stress factors. Ultrastructural changes of the hepatopancreatic cells in the terrestrial isopod Porcellio scaber exposed to sublethal concentrations of zinc or cadmium in their food were identified by transmission electron microscopy. The exclusive structural characteristic of the hepatopancreas of animals exposed to metal-dosed food was grain-like electrondense deposits (EDD) observed in the intercellular spaces and in vesicles of B cells. In addition, hepatopancreatic cells of metal-exposed animals displayed non-specific, stress-indicating alterations such as cellular disintegration, the reduction of energetic reserves (lipid droplets, glycogen), electron dense cytoplasm, ultrastructural alterations of granular endoplasmic reticulum (GER), the Golgi complex and mitochondria.

  8. Cell Ultrastructure of Kiwifruit (Actinidia chinensis) Shoot Tips During Cryopreservation

    Institute of Scientific and Technical Information of China (English)

    XU Xiao-biao; CAI Zi-guo; GU Qing-qing; ZHANG Qiu-ming

    2006-01-01

    The changes in the cell ultrastructure of in vitro cultured shoot tips from dwarf genotype of kiwifruit (Actinidia chinensis Ganmi 5) during cryopreservation were investigated. Shoot tips were preserved in liquid nitrogen using vitrification, and the cell ultrastructure was examined using transmission electron microscopy (TEM). The regular ultrastructure of the cell wall, cell membrane and nucleus of shoot tips could be damaged during the freezing and thawing associated with preservation using liquid nitrogen. The cell plasmolysis was increased and freezing tolerance was improved after preculturing and dehydrating in a preservation and vitrification solution (PVS2 ) (30% glycerol (Gly)+ 15% ethylene glycol (EG)+ 15% dimethylsulfoxide (DMSO) + 0.4 mol L-1 sucrose). The structure of some cells with low degree of injury and reversible damage was similar to that of the control and they could undergo normal cell division and differentiation. Besides, they could recover automatically and regenerate after their reculture.

  9. THE ULTRASTRUCTURE OF SEPARATED AND CULTURED CELL OF PORPHYRA YEZOENSIS

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    There are many reports that cells (protoplasts) separated from the thallus of Porphyra by enzyme can develop to normal leafy thalli in the same way as monospores. But there are few investigations on the subcellular structure of the isolated vegetative cell for comparison with the subcellular structure of monospores. To clarify whether the separated and cultured cells undergo the same or similar ultrastructure changes during culture and germination as monospores undergo in their formation and germination, we observed their ultrastructure, compared them with those of the monospore and found that the ultrastructure of separated and cultured cells did not have the characteristic feature as that of monospore formation, such as production of small and large fibrous vesicles, but was accompanied by vacuolation and starch mobilization like that in monospore germination. The paper also discusses the relations between monospores and separated and cultured cells.

  10. The Comparative Study on Ultrastructure and Immunohistochemistry in AFP Negative and Positive Hepatocellular Carcinoma

    Institute of Scientific and Technical Information of China (English)

    郑美蓉; 阮幼冰; 杨木兰; 官阳; 武忠弼

    2004-01-01

    To comparatively investigate ultrastructural characteristics and expressions of AFP(alpha-fetoprotein) and Tn (Thomsen-Friedenreich-related antigen) protein in AFP negative (AFP-)and AFP positive (AFP+) primary hepatocellular carcinoma. Fourty-three cases of AFP- and AFP+ hepatocellular carcinoma (HCC) tissues and five cases of normal liver tissues were divided into three groups: control group (normal liver tissue, n=5); AFP+ HCC group (the serum AFP level was higher than 10 ng/ml, n = 22); AFP- HCC group (the serum AFP level was lower than 10 ng/ml, n=21). The ultrastructural morphology was studied by transmission electron microscopy, the expressions of AFP and Tn protein were detected by immunohistochemistry and cell image analysis. 1. The immunohistochemical study showed that (1) the expression intensity and positive rate of Tn protein in AFP- HCC group were markedly higher than that in AFP+ HCC group (P<0.01); (2) The expression intensity of AFP in AFP- HCC group was lower than that in AFP+ HCC group (P<0.01 ). 2. The transmission electron microscopy demonstrated that some AFP- HCC cells linked closely with each other, others dispersed loosely just as cultured cells, the remarkable morphologic features in AFP- HCC cells were simple organelles, But they were abundant in the free polyribosomes. In AFP+ HCC group, all the HCC cells linked closely together and were rich organelles in their cytoplasm, especially the rough endoplasmic reticula. In addition, mitochondria and Golgi complex were obviously observed. (1) The AFP and Tn protein had discrepancy distribution in AFP- and AFP+ HCC tissues, Tn protein may be one of the early diagnostic indicators in AFP- HCC; (2) The synthetic locations of the AFP and Tn protein were different in hepatocarcinoma cells by ultrastructural observation.

  11. Structural and ultrastructural features of the agouti tongue (Dasyprocta aguti Linnaeus, 1766).

    Science.gov (United States)

    Ciena, Adriano Polican; de Sousa Bolina, Cristina; de Almeida, Sonia Regina Yokomizo; Rici, Rose Eli Grassi; de Oliveira, Moacir Franco; da Silva, Marcelo Cavenaghi Pereira; Miglino, Maria Angélica; Watanabe, Ii-sei

    2013-08-01

    The agouti (Dasyprocta aguti Linnaeus, 1766) is a wild rodent belonging to the family Dasyproctidae that is found throughout Brazil and feeds on fruits and seeds. The aim of the present study was to describe the following features of the tongue of agouti: its morphological structures, the three-dimensional characteristics of the lingual papillae surface, the connective tissue cores (CTCs) and the epithelial cell ultrastructure. Four types of papillae were observed on the dorsal surface of the tongue with a triangular shape: filiform, fungiform, foliate and vallate. Filiform papillae were distributed throughout the tongue surface, and removal of the epithelial surface revealed conical CTCs and multifilaments. Fungiform papillae were observed in the rostral and middle regions, whereas foliate papillae developed in pairs on the lateral margin of the caudal region. Removal of the epithelium in these regions revealed CTCs with parallel laminar conformation. Vallate papillae were arranged in a V-shape in the caudal region, and their CTCs ranged in shape from elongate to ovoid. The ultrastructural components of the dorsal epithelium were the basal, spinous, granular and keratinised layers. A broad area with cytoplasmic projections was identified in the interface region between the lamina propria and the basal layer. Flattened cells with intermediate filaments were observed in the transitional region between spinous and granular layers. The keratinised layer was composed of superimposed epithelial cells where desmosomes and cell-surface microridges were observed. These structural features, including the three-dimensional aspects of the lingual papillae, the CTCs and the epithelial ultrastructure, indicate that when compared with other animals, particularly other rodent species, the morphological features of the tongue of agouti are relatively well developed, especially regarding foliate and vallate papillae.

  12. A histological study of testis development and ultrastructural features of spermatogenesis in cultured Acrossocheilus fasciatus.

    Science.gov (United States)

    Fu, Su-Yan; Jiang, Jian-Hu; Yang, Wan-Xi; Zhu, Jun-Quan

    2016-02-01

    Testis development and ultrastructural features of spermatogenesis in Acrossocheilus fasciatus (Cypriniformes, Barbinae), a commercial stream fish, were studied using light and electron microscopy. The reproduction cycle in A. fasciatus testes is classified into six successive stages from Stage I to Stage VI. Based on an analysis of previous results, May to July can be confirmed as the best breeding season for A. fasciatus males. During this time, the A. fasciatus testes are in Stage V and the sperm in males is most abundant. In the first reproductive cycle, sexually mature male testes return to Stage III in October, subsequently overwintering at this stage. In the lobular-type testes of A. fasciatus, cystic type spermatogenesis occurs with restricted spermatogonia. All spermatogenic cells at different stages are distributed along the seminiferous lobules, which contain spermatogonia, spermatocytes, spermatids and spermatozoa. At the end of spermatogenesis, spermatogenic cysts open to release spermatozoa into the lobule lumen. Ultrastructural observation of A. fasciatus spermiogenesis reveals that electron-dense substances appear at the different stages of germ cells, from primary spermatogonia to secondary spermatocytes. We have termed these dense substances as "nuage" when free in the cytoplasm or adjacent to the nuclear envelope, while those close to the mitochondria are called inter-mitochondrial cement. The spermatozoa in A. fasciatus can be classified as type I due to the presence of nuclear rotation. Although the nuclear chromatin in the head of sperm was highly condensed, no acrosome was formed. The cytoplasmic canal, a common ultrastructural feature of Teleostei spermatozoa, was also present in the midpiece. In addition, numerous fused mitochondria were observed. The distal centriole and proximal centriole constituting the centriolar complex were oriented incompletely perpendicular to each other. The flagellum showed a typical 9+2 arrangement pattern

  13. Analysis of high–dose rate brachytherapy dose distribution resemblance in CyberKnife hypofractionated treatment plans of localized prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Sudahar, H., E-mail: h.sudahar@gmail.com [Department of Radiotherapy, Apollo Speciality Hospital, Chennai (India); Kurup, P.G.G.; Murali, V.; Mahadev, P. [Department of Radiotherapy, Apollo Speciality Hospital, Chennai (India); Velmurugan, J. [Department of Medical Physics, Anna University, Chennai (India)

    2013-01-01

    The present study is to analyze the CyberKnife hypofractionated dose distribution of localized prostate cancer in terms of high–dose rate (HDR) brachytherapy equivalent doses to assess the degree of HDR brachytherapy resemblance of CyberKnife dose distribution. Thirteen randomly selected localized prostate cancer cases treated using CyberKnife with a dose regimen of 36.25 Gy in 5 fractions were considered. HDR equivalent doses were calculated for 30 Gy in 3 fractions of HDR brachytherapy regimen. The D{sub 5%} of the target in the CyberKnife hypofractionation was 41.57 ± 2.41 Gy. The corresponding HDR fractionation (3 fractions) equivalent dose was 32.81 ± 1.86 Gy. The mean HDR fractionation equivalent dose, D{sub 98%}, was 27.93 ± 0.84 Gy. The V{sub 100%} of the prostate target was 95.57% ± 3.47%. The V{sub 100%} of the bladder and the rectum were 717.16 and 79.6 mm{sup 3}, respectively. Analysis of the HDR equivalent dose of CyberKnife dose distribution indicates a comparable resemblance to HDR dose distribution in the peripheral target doses (D{sub 98%} to D{sub 80%}) reported in the literature. However, there is a substantial difference observed in the core high-dose regions especially in D{sub 10%} and D{sub 5%}. The dose fall-off within the OAR is also superior in reported HDR dose distribution than the HDR equivalent doses of CyberKnife.

  14. Distribution and localization of fibroblast growth factor-8 in rat brain and nerve cells during neural stem/progenitor cell differentiation

    Institute of Scientific and Technical Information of China (English)

    Jiang Lu; Dongsheng Li; Kehuan Lu

    2012-01-01

    The present study explored the distribution and localization of fibroblast growth factor-8 and its potential receptor,fibroblast growth factor receptor-3,in adult rat brain in vivo and in nerve cells during differentiation of neural stem/progenitor cells in vitro.Immunohistochemistry was used to examine the distribution of fibroblast growth factor-8 in adult rat brain in vivo.Localization of fibroblast growth factor-8 and fibroblast growth factor receptor-3 in cells during neural stem/progenitor cell differentiation in vitro was detected by immunofluorescence.Flow cytometry and immunofluorescence were used to evaluate the effect of an anti-fibroblast growth factor-8 antibody on neural stem/progenitor cell differentiation and expansion in vitro.Results from this study confirmed that fibroblast growth factor-8 was mainly distributed in adult midbrain,namely the substantia nigra,compact part,dorsal tier,substantia nigra and reticular part,but was not detected in the forebrain comprising the caudate putamen and striatum.Unusual results were obtained in retrosplenial locations of adult rat brain.We found that fibroblast growth factor-8 and fibroblast growth factor receptor-3 were distributed on the cell membrane and in the cytoplasm of nerve cells using immunohistochemistry and immunofluorescence analyses.We considered that the distribution of fibroblast growth factor-8 and fibroblast growth factor receptor-3 in neural cells corresponded to the characteristics of fibroblast growth factor-8,a secretory factor.Addition of an anti-fibroblast growth factor-8 antibody to cultures significantly affected the rate of expansion and differentiation of neural stem/progenitor cells.In contrast,addition of recombinant fibroblast growth factor-8 to differentiation medium promoted neural stem/progenitor cell differentiation and increased the final yields of dopaminergic neurons and total neurons.Our study may help delineate the important roles of fibroblast growth factor-8 in brain

  15. Distribution of Local Open-Circuit Voltage on Amorphous and Nanocrystalline Mixed-Phase Si:H and SiGe:H Solar Cells: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, C.-S.; Moutinho, H. R.; Al-Jassim, M. M.; Kazmerski, L. L.; Yan, B.; Owens, J. M.; Yang, J.; Guha, S.

    2006-05-01

    Local open-circuit voltage (Voc) distributions on amorphous and nanocrystalline mixed-phase silicon solar cells were measured using a scanning Kelvin probe microscope (SKPM) on the p layer of an n-i-p structure without the top ITO contact. During the measurement, the sample was illuminated with a laser beam that was used for the atomic force microscopy (AFM). Therefore, the surface potential measured by SKPM is the sum of the local Voc and the difference in workfunction between the p layer and the AFM tip. Comparing the SKPM and AFM images, we find that nanocrystallites aggregate in the amorphous matrix with an aggregation size of {approx}0.5 ..mu..m in diameter, where many nanometer-size grains are clustered. The Voc distribution shows valleys in the nanocrystalline aggregation area. The transition from low to high Voc regions is a gradual change within a distance of about 1 ..mu..m. The minimum Voc value in the nanocrystalline clusters in the mixed-phase region is larger than the Voc of a nc-Si:H single-phase solar cell. These results could be due to lateral photo-charge redistribution between the two phases. We have also carried out local Voc measurements on mixed-phase SiGe:H alloy solar cells. The magnitudes of Voc in the amorphous and nanocrystalline regions are consistent with the J-V measurements.

  16. Acoustic Source Localization via Time Difference of Arrival Estimation for Distributed Sensor Networks using Tera-scale Optical-Core Devices

    Energy Technology Data Exchange (ETDEWEB)

    Imam, Neena [ORNL; Barhen, Jacob [ORNL

    2009-01-01

    For real-time acoustic source localization applications, one of the primary challenges is the considerable growth in computational complexity associated with the emergence of ever larger, active or passive, distributed sensor networks. These sensors rely heavily on battery-operated system components to achieve highly functional automation in signal and information processing. In order to keep communication requirements minimal, it is desirable to perform as much processing on the receiver platforms as possible. However, the complexity of the calculations needed to achieve accurate source localization increases dramatically with the size of sensor arrays, resulting in substantial growth of computational requirements that cannot be readily met with standard hardware. One option to meet this challenge builds upon the emergence of digital optical-core devices. The objective of this work was to explore the implementation of key building block algorithms used in underwater source localization on the optical-core digital processing platform recently introduced by Lenslet Inc. This demonstration of considerably faster signal processing capability should be of substantial significance to the design and innovation of future generations of distributed sensor networks.

  17. Cryogenic-temperature profiling of high-power superconducting lines using local and distributed optical-fiber sensors.

    Science.gov (United States)

    Chiuchiolo, Antonella; Palmieri, Luca; Consales, Marco; Giordano, Michele; Borriello, Anna; Bajas, Hugues; Galtarossa, Andrea; Bajko, Marta; Cusano, Andrea

    2015-10-01

    This contribution presents distributed and multipoint fiber-optic monitoring of cryogenic temperatures along a superconducting power transmission line down to 30 K and over 20 m distance. Multipoint measurements were conducted using fiber Bragg gratings sensors coated with two different functional overlays (epoxy and poly methyl methacrylate (PMMA)) demonstrating cryogenic operation in the range 300-4.2 K. Distributed measurements exploited optical frequency-domain reflectometry to analyze the Rayleigh scattering along two concatenated fibers with different coatings (acrylate and polyimide). The integrated system has been placed along the 20 m long cryostat of a superconducting power transmission line, which is currently being tested at the European Organization for Nuclear Research (CERN). Cool-down events from 300-30 K have been successfully measured in space and time, confirming the viability of these approaches to the monitoring of cryogenic temperatures along a superconducting transmission line.

  18. Cryogenic-temperature profiling of high-power superconducting lines using local and distributed optical-fiber sensors

    CERN Document Server

    Chiuchiolo, Antonella; Consales, Marco; Giordano, Michele; Borriello, Anna; Bajas, Hugues; Galtarossa, Andrea; Bajko, Marta; Cusano, Andrea

    2015-01-01

    This contribution presents distributed and multi-point fiber-optic monitoring of cryogenic temperatures along a superconducting power transmission line down to 30 K and over 20 m distance. Multi-point measurements were conducted using fiber Bragg gratings sensors coated with two different functional overlays (epoxy and PMMA) demonstrating cryogenic operation in the range 300 – 4.2 K. Distributed measurements exploited optical frequency-domain reflectometry to analyze the Rayleigh scattering along two concatenated fibers with different coatings (acrylate and polyimide). The integrated system has been placed along the 20 m long cryostat of a superconducting power transmission line, which is currently being tested at the European Organization for Nuclear Research (CERN). Cool-down events from 300 K to 30 K have been successfully measured in space and time, confirming the viability of these approaches to the monitoring of cryogenic temperatures along a superconducting transmission line.

  19. Abundance and Summer Distribution of a Local Stock of Black Sea Bottlenose Dolphins, Tursiops truncatus (Cetacea, Delphinidae, in Coastal Waters near Sudak (Ukraine, Crimea

    Directory of Open Access Journals (Sweden)

    Gladilina E. V.

    2016-02-01

    Full Text Available The first assessment of abundance of a local population of bottlenose dolphins in the Black Sea (near the Sudak coast in 2011–2012 has been conducted: the results of a mark-recapture study of photo identified animals were complemented by a vessel line transect survey. The overall abundance of a population was estimated at between 621 ± 198 and 715 ± 267 animals (Chapman and Petersen estimates, and the majority of members of the population were recorded in the surveyed area. The summer range covered the area of a few hundred square kilometers, similar to migrating coastal stocks in other world regions. The greatest density of distribution was observed in August in sea 45–60 m deep; in addition, frequent approaches to the coastline are usual for dolphins of this stock. These trends in distribution may be partly explained by distribution of prey. Interaction with sprat trawling fisheries can be a factor shaping the local population structure. Coastal waters of Sudak and adjoining sea areas are an important habitat for bottlenose dolphins in the northern Black Sea, significant for their conservation.

  20. Micro-macro model for prediction of local temperature distribution in heterogeneous and two-phase media

    Directory of Open Access Journals (Sweden)

    Furmański Piotr

    2014-09-01

    Full Text Available Heat flow in heterogeneous media with complex microstructure follows tortuous path and therefore determination of temperature distribution in them is a challenging task. Two-scales, micro-macro model of heat conduction with phase change in such media was considered in the paper. A relation between temperature distribution on the microscopic level, i.e., on the level of details of microstructure, and the temperature distribution on the macroscopic level, i.e., on the level where the properties were homogenized and treated as effective, was derived. The expansion applied to this relation allowed to obtain its more simplified, approximate form corresponding to separation of micro- and macro-scales. Then the validity of this model was checked by performing calculations for 2D microstructure of a composite made of two constituents. The range of application of the proposed micro-macro model was considered in transient states of heat conduction both for the case when the phase change in the material is present and when it is absent. Variation of the effective thermal conductivity with time was considered and a criterion was found for which application of the considered model is justified.

  1. In situ localization and tissue distribution of the replication-associated proteins of Cucumber mosaic virus in tobacco and cucumber.

    Science.gov (United States)

    Cillo, Fabrizio; Roberts, Ian M; Palukaitis, Peter

    2002-11-01

    The replication-associated proteins encoded by Cucumber mosaic virus (CMV), the 1a and 2a proteins, were detected by immunogold labeling in two host species of this virus, tobacco (Nicotiana tabacum) and cucumber (Cucumis sativus). In both hosts, the 1a and 2a proteins colocalized predominantly to the vacuolar membranes, the tonoplast. While plus-strand CMV RNAs were found distributed throughout the cytoplasm by in situ hybridization, minus-strand CMV RNAs were barely detectable but were found associated with the tonoplast. In both cucumber and tobacco, 2a protein was detected at higher densities than 1a protein. The 1a and 2a proteins also showed quantitative differences with regard to tissue distributions in tobacco and cucumber. About three times as much 2a protein was detected in CMV-infected cucumber tissues as in CMV-infected tobacco tissues. In tobacco, high densities of these proteins were observed only in vascular bundle cells of minor veins. In contrast, in cucumber, high densities of 1a and 2a proteins were observed in mesophyll cells, followed by epidermis cells, with only low levels being observed in vascular bundle cells. Differences were also observed in the distributions of 2a protein and capsid protein in vascular bundle cells of the two host species. These observations may represent differences in the relative rates of tissue infection in different hosts or differences in the extent of virus replication in vascular tissues of different hosts.

  2. Quantitation and localization of regional body fat distribution--a comparison between magnetic resonance imaging and somatometry.

    Science.gov (United States)

    Sharma, R C; Kramsch, D M; Lee, P L; Colletti, P; Jiao, Q

    1996-03-01

    The emerging concept that various fat compartments are metabolically active and play separate and decisive roles in the pathogenesis of coronary atherosclerosis, hypertension, insulin resistance, diabetes and stroke, has given obesity research a new direction. Of particular interest is the relative amount of intra-abdominal fat thought to be responsible for the metabolic complications. We studied the precise fat distribution and its correlations with the metabolic parameters in 44 non-human primates (Macaca fascicularis). Intra-abdominal, subcutaneous, and total abdominal fat (IAF, SAF, TAF) were assessed by magnetic resonance imaging (MRI) and somatometry. Quantitative computer analyses of abdominal MRI scans revealed predominant IAF distribution. Box plot analysis of IAF and SAF revealed wide diversity in the amounts of fat, especially in monkeys with body mass index (BMI) < 30 kg/m2. Primates with similar BMI in each quartile revealed an extensive heterogeneity in IAF as well as SAF. Numerous significant correlations within site-specific somatometric measurements as well as within the MRI determinants of abdominal fat were seen. However, only body weight correlated with IAF and skinfolds could predict SAF. After adjusting for body weight, partial correlation analysis showed a significant correlation (P < 0.05) between total cholesterol and IAF. MRI revealed considerable heterogeneity of IAF, SAF and TAF in cohort of primates believed to be homogeneous by somatometric definition. Male cynomolgus monkeys appear to be a valuable model for a systematic evaluation of fat. Individuals with identical body weight and height may show a diverse pattern of fat distribution.

  3. Basilar artery of the capybara (Hydrochaeris hydrochaeris): an ultrastructural study.

    Science.gov (United States)

    Islam, S; Ribeiro, A A C M; Loesch, A

    2004-04-01

    The present study investigated the ultrastructural features of the basilar artery of the largest rodent species, the capybara. The study suggests that the general ultrastructural morphological organization of the basilar artery of the capybara is similar to that of small rodents. However, there are some exceptions. The basilar artery of the capybara contains a subpopulation of 'granular' vascular smooth muscle cells resembling monocytes and/or macrophages. The possibility cannot be excluded that the presence of these cells reflects the remodelling processes of the artery due to animal maturation and the regression of the internal carotid artery. To clarify this issue, more systemic studies are required involving capybaras of various ages.

  4. [Morphological and Ultrastructural Features in the Characterization of Microsporidia].

    Science.gov (United States)

    Yaman, Mustafa; Algı, Gönül; Güner, Beyza Gonca

    2015-03-01

    The members of the Microsporidia are single-celled, eukaryotic, obligate intracellular parasites. They infect a wide range of invertebrate and vertebrate hosts. The studies on Microsporidia are of considerable interest because of that they cause desirable and undesirable infections in different animals. That situation requires identification of these organisms correctly. The identification of Microsporidia needs relatively more complex studies. Morphological and ultrastructural studies play important role in the identification of these organisms. In the present study, a working knowledge on the morphological and ultrastructural features of Microsporidia are given.

  5. Effect of rib angle on local heat/mass transfer distribution in a two-pass rib-roughened channel

    Science.gov (United States)

    Chandra, P. R.; Han, J. C.; Lau, S. C.

    1987-01-01

    The naphthalene sublimation technique is used to investigate the heat transfer characteristics of turbulent air flow in a two-pass channel. A test section that resembles the internal cooling passages of gas turbine airfoils is employed. The local Sherwood numbers on the ribbed walls were found to be 1.5-6.5 times those for a fully developed flow in a smooth square duct. Depending on the rib angle-of-attack and the Reynolds number, the average ribbed-wall Sherwood numbers were 2.5-3.5 times higher than the fully developed values.

  6. Spatio-temporal distribution of injured elephants in Masai Mara and the putative negative and positive roles of the local community.

    Directory of Open Access Journals (Sweden)

    Domnic Mijele

    Full Text Available BACKGROUND: Very few studies have ever focused on the elephants that are wounded or killed as local communities attempt to scare these animals away from their settlements and farms, or on the cases in which local people take revenge after elephants have killed or injured humans. On the other hand, local communities live in close proximity to elephants and hence can play a positive role in elephant conservation by informing the authorities of the presence of injured elephants. METHODOLOGY/PRINCIPAL FINDINGS: Between 2007 and 2011, 129 elephants were monitored in Masai Mara (Kenya, of which 54 had various types of active (intentionally caused or passive (non-intentionally caused injuries. Also studied were 75 random control samples of apparently unaffected animals. The observed active injuries were as expected biased by age, with adults suffering more harm; on the other hand, no such bias was observed in the case of passive injuries. Bias was also observed in elephant sex since more males than females were passively and actively injured. Cases of passive and active injuries in elephants were negatively related to the proximity to roads and farms; the distribution of injured elephants was not affected by the presence of either human settlements or water sources. Overall more elephants were actively injured during the dry season than the wet season as expected. Local communities play a positive role by informing KWS authorities of the presence of injured elephants and reported 43% of all cases of injured elephants. CONCLUSIONS: Our results suggest that the negative effect of local communities on elephants could be predicted by elephant proximity to farms and roads. In addition, local communities may be able to play a more positive role in elephant conservation given that they are key informants in the early detection of injured elephants.

  7. Spatio-temporal distribution of injured elephants in Masai Mara and the putative negative and positive roles of the local community.

    Science.gov (United States)

    Mijele, Domnic; Obanda, Vincent; Omondi, Patrick; Soriguer, Ramón C; Gakuya, Francis; Otiende, Moses; Hongo, Peter; Alasaad, Samer

    2013-01-01

    Very few studies have ever focused on the elephants that are wounded or killed as local communities attempt to scare these animals away from their settlements and farms, or on the cases in which local people take revenge after elephants have killed or injured humans. On the other hand, local communities live in close proximity to elephants and hence can play a positive role in elephant conservation by informing the authorities of the presence of injured elephants. Between 2007 and 2011, 129 elephants were monitored in Masai Mara (Kenya), of which 54 had various types of active (intentionally caused) or passive (non-intentionally caused) injuries. Also studied were 75 random control samples of apparently unaffected animals. The observed active injuries were as expected biased by age, with adults suffering more harm; on the other hand, no such bias was observed in the case of passive injuries. Bias was also observed in elephant sex since more males than females were passively and actively injured. Cases of passive and active injuries in elephants were negatively related to the proximity to roads and farms; the distribution of injured elephants was not affected by the presence of either human settlements or water sources. Overall more elephants were actively injured during the dry season than the wet season as expected. Local communities play a positive role by informing KWS authorities of the presence of injured elephants and reported 43% of all cases of injured elephants. Our results suggest that the negative effect of local communities on elephants could be predicted by elephant proximity to farms and roads. In addition, local communities may be able to play a more positive role in elephant conservation given that they are key informants in the early detection of injured elephants.

  8. Uniform spatial distribution of collagen fibril radii within tendon implies local activation of pC-collagen at individual fibrils

    Science.gov (United States)

    Rutenberg, Andrew D.; Brown, Aidan I.; Kreplak, Laurent

    2016-08-01

    Collagen fibril cross-sectional radii show no systematic variation between the interior and the periphery of fibril bundles, indicating an effectively constant rate of collagen incorporation into fibrils throughout the bundle. Such spatially homogeneous incorporation constrains the extracellular diffusion of collagen precursors from sources at the bundle boundary to sinks at the growing fibrils. With a coarse-grained diffusion equation we determine stringent bounds, using parameters extracted from published experimental measurements of tendon development. From the lack of new fibril formation after birth, we further require that the concentration of diffusing precursors stays below the critical concentration for fibril nucleation. We find that the combination of the diffusive bound, which requires larger concentrations to ensure homogeneous fibril radii, and lack of nucleation, which requires lower concentrations, is only marginally consistent with fully processed collagen using conservative bounds. More realistic bounds may leave no consistent concentrations. Therefore, we propose that unprocessed pC-collagen diffuses from the bundle periphery followed by local C-proteinase activity and subsequent collagen incorporation at each fibril. We suggest that C-proteinase is localized within bundles, at fibril surfaces, during radial fibrillar growth. The much greater critical concentration of pC-collagen, as compared to fully processed collagen, then provides broad consistency between homogeneous fibril radii and the lack of fibril nucleation during fibril growth.

  9. Distribution and Localization of 5-HT1A Receptors in the Rat Lumbar Spinal Cord after Transection and Deafferentation

    Science.gov (United States)

    Otoshi, Chad K.; Walwyn, Wendy M.; Tillakaratne, Niranjala J.K.; Zhong, Hui; Roy, Roland R.

    2009-01-01

    Abstract The serotonergic system is highly plastic, capable of adapting to changing afferent information in diverse mammalian systems. We hypothesized that removing supraspinal and/or peripheral input would play an important role in defining the distribution of one of the most prevalent serotonergic receptors, the 5-HT1A receptor (R), in the spinal cord. We investigated the distribution of this receptor in response to a complete thoracic (T7–T8) spinal cord transection (eliminating supraspinal input), or to spinal cord isolation (eliminating both supraspinal and peripheral input) in adult rats. Using two antibodies raised against either the second extracellular region (ECL2) or the third intracellular region (ICL3) of the 5-HT1AR, we compared the 5-HT1AR levels and distributions in specific laminae of the L3–L5 segments among the control, spinal cord–transected, and spinal cord–isolated groups. Each antibody labeled different populations of 5-HT1AR: ECL2 labeled receptors in the axon hillock, whereas ICL3 labeled receptors predominantly throughout the soma and proximal dendrites. Spinal cord transection increased the number of ECL2-positive cells in the medial region of laminae III–IV and lamina VII, and the mean length of the labeled axon hillocks in lamina IX. The number of ICL3-labeled cells was higher in lamina VII and in both the medial and lateral regions of lamina IX in the spinal cord–transected compared to the control group. In contrast, the length and number of ECL2-immunolabeled processes and ICL3-immunolabeled cells were similar in the spinal cord–isolated and control groups. Combined, these data demonstrate that the upregulation in 5-HT1AR that occurs with spinal cord transection alone is dependent on the presence of sensory input. PMID:19260781

  10. Distribution and localization of 5-HT(1A) receptors in the rat lumbar spinal cord after transection and deafferentation.

    Science.gov (United States)

    Otoshi, Chad K; Walwyn, Wendy M; Tillakaratne, Niranjala J K; Zhong, Hui; Roy, Roland R; Edgerton, V Reggie

    2009-04-01

    The serotonergic system is highly plastic, capable of adapting to changing afferent information in diverse mammalian systems. We hypothesized that removing supraspinal and/or peripheral input would play an important role in defining the distribution of one of the most prevalent serotonergic receptors, the 5-HT(1A) receptor (R), in the spinal cord. We investigated the distribution of this receptor in response to a complete thoracic (T7-T8) spinal cord transection (eliminating supraspinal input), or to spinal cord isolation (eliminating both supraspinal and peripheral input) in adult rats. Using two antibodies raised against either the second extracellular region (ECL(2)) or the third intracellular region (ICL(3)) of the 5-HT(1A)R, we compared the 5-HT(1A)R levels and distributions in specific laminae of the L3-L5 segments among the control, spinal cord-transected, and spinal cord-isolated groups. Each antibody labeled different populations of 5-HT(1A)R: ECL(2) labeled receptors in the axon hillock, whereas ICL(3) labeled receptors predominantly throughout the soma and proximal dendrites. Spinal cord transection increased the number of ECL(2)-positive cells in the medial region of laminae III-IV and lamina VII, and the mean length of the labeled axon hillocks in lamina IX. The number of ICL(3)-labeled cells was higher in lamina VII and in both the medial and lateral regions of lamina IX in the spinal cord-transected compared to the control group. In contrast, the length and number of ECL(2)-immunolabeled processes and ICL(3)-immunolabeled cells were similar in the spinal cord-isolated and control groups. Combined, these data demonstrate that the upregulation in 5-HT(1A)R that occurs with spinal cord transection alone is dependent on the presence of sensory input.

  11. Detecting Local Deflection Patterns of Ultra-high Energy Cosmic Rays using the Principal Axes of the Directional Energy Distribution

    CERN Document Server

    Erdmann, Martin

    2013-01-01

    From deflections in galactic and extragalactic magnetic fields energy dependent structures in the arrival directions of ultra-high energy cosmic rays (UHECR) are expected. We propose to characterize these structures by the strength of collimation of energy along the principal axes in selected regions in the sky. While the strength of collimation are indicators of anisotropy in the arrival distribution of UHECR, the orientation of the principal system holds information about the direction of the deflections of UHECR. We discuss the method and present expected limits on the strength of deflection and density of sources using simulated scenarios of UHECR proton propagation.

  12. Imaging analysis of collagen fiber networks in cusps of porcine aortic valves: effect of their local distribution and alignment on valve functionality.

    Science.gov (United States)

    Mega, Mor; Marom, Gil; Halevi, Rotem; Hamdan, Ashraf; Bluestein, Danny; Haj-Ali, Rami

    2016-01-01

    The cusps of native aortic valve (AV) are composed of collagen bundles embedded in soft tissue, creating a heterogenic tissue with asymmetric alignment in each cusp. This study compares native collagen fiber networks (CFNs) with a goal to better understand their influence on stress distribution and valve kinematics. Images of CFNs from five porcine tricuspid AVs are analyzed and fluid-structure interaction models are generated based on them. Although the valves had similar overall kinematics, the CFNs had distinctive influence on local mechanics. The regions with dilute CFN are more prone to damage since they are subjected to higher stress magnitudes.

  13. Ultrastructure and calcium balance in meristem cells of pea roots exposed to extremely low magnetic fields

    Science.gov (United States)

    Belyavskaya, N. A.

    2001-01-01

    Investigations of low magnetic field (LMF) effects on biological systems have attracted attention of biologists due to planned space flights to other planets where the field intensity does not exceed 10 -5 Oe. Pea ( Pisum sativum L.) seeds were grown in an environment of LMF 3 days. In meristem cells of roots exposed to LMF, one could observe such ultrastructural peculiarities as a noticeable accumulation of lipid bodies, development of a lytic compartment (vacuoles, cytosegresomes and paramural bodies), and reduction of phytoferritin in plastids. Mitochondria were the most sensitive organelle to LMF application. Their size and relative volume in cells increased, matrix was electron-transparent, and cristae reduced. Because of the significant role of calcium signalling in plant responses to different environmental factors, calcium participation in LMF effects was investigated using a pyroantimonate method to identify the localization of free calcium ions. The intensity of cytochemical reaction in root cells after LMF application was strong. The Ca 2+ pyroantimonate deposits were observed both in all organelles and in a hyaloplasm of the cells. Data obtained suggest that the observed LMF effects on ultrastructure of root cells were due to disruptions in different metabolic systems including effects on Ca 2+ homeostasis.

  14. Pb and Cd on growth, leaf ultrastructure and essential oil yield mint (Mentha arvensis L.

    Directory of Open Access Journals (Sweden)

    Caroline Nery Jezler

    2015-03-01

    Full Text Available Contamination of medicinal plants with heavy metals as Pb and Cd can affect the growth and the essential oil production of the plants and represent a risk to those who consume as medicine. This study aimed to evaluate the effects of absorption and localization of Pb and Cd on growth, ultrastructural aspects of leaves and essential oil yield and composition of Mentha arvensis, applied on the soil with increasing concentrations (8, 16, 32, 64 and 128mg kg-1. There was a differential absorption of Pb and Cd by M. arvensis mainly concentrated in the roots. Pb was found in small amounts in the leaves while Cd largely exceeded the safety limit without symptoms of toxicity. The ultrastructural analysis revealed the metal accumulation on vesicles surrounding the mitochondria and the presence of electron dense deposits surrounding the mitochondria, nucleus and chloroplasts. Little changes caused by Pb and Cd application were not enough to affect the growth and essential oil yield and composition of M. arvensis

  15. Angular distribution of Rh atoms desorbed from ion-bombarded Rh l brace 100 r brace : Effect of local environment

    Energy Technology Data Exchange (ETDEWEB)

    Maboudian, R.; Postawa, Z.; El-Maazawi, M.; Garrison, B.J.; Winograd, N. (Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802 (USA))

    1990-10-15

    Energy-resolved angular distributions of Rh atoms desorbed by 5 keV Ar-ion bombardment of the Rh{l brace}100{r brace} surface are measured with use of a multiphoton resonance ionization technique. The results are shown to be in good agreement with molecular-dynamics simulations of the ion-impact event using the same interaction potential optimized previously to describe desorption from Rh{l brace}111{r brace}. In addition, by analyzing contour plots of the surface potential energy, the trend in the experimental results for Rh{l brace}100{r brace} and those previously published for Rh{l brace}111{r brace} are well explained. Based on this analysis, it is concluded that the peak in the polar-angle distribution of neutral particles desorbed from ion-bombarded single crystals is mainly determined by the relative positions of surface atoms which influence the trajectory of an exiting particle via channeling and blocking. Moreover, the anisotropy of the momentum imparted to the surface atoms in the last collision leads to an enhancement of ejection along certain crystallographic directions.

  16. Simulating the effects of climate change on the distribution of an invasive plant, using a high resolution, local scale, mechanistic approach: challenges and insights.

    Science.gov (United States)

    Fennell, Mark; Murphy, James E; Gallagher, Tommy; Osborne, Bruce

    2013-04-01

    The growing economic and ecological damage associated with biological invasions, which will likely be exacerbated by climate change, necessitates improved projections of invasive spread. Generally, potential changes in species distribution are investigated using climate envelope models; however, the reliability of such models has been questioned and they are not suitable for use at local scales. At this scale, mechanistic models are more appropriate. This paper discusses some key requirements for mechanistic models and utilises a newly developed model (PSS[gt]) that incorporates the influence of habitat type and related features (e.g., roads and rivers), as well as demographic processes and propagule dispersal dynamics, to model climate induced changes in the distribution of an invasive plant (Gunnera tinctoria) at a local scale. A new methodology is introduced, dynamic baseline benchmarking, which distinguishes climate-induced alterations in species distributions from other potential drivers of change. Using this approach, it was concluded that climate change, based on IPCC and C4i projections, has the potential to increase the spread-rate and intensity of G. tinctoria invasions. Increases in the number of individuals were primarily due to intensification of invasion in areas already invaded or in areas projected to be invaded in the dynamic baseline scenario. Temperature had the largest influence on changes in plant distributions. Water availability also had a large influence and introduced the most uncertainty in the projections. Additionally, due to the difficulties of parameterising models such as this, the process has been streamlined by utilising methods for estimating unknown variables and selecting only essential parameters.

  17. Spent metal working fluids produced alterations on photosynthetic parameters and cell-ultrastructure of leaves and roots of maize plants.

    Science.gov (United States)

    Grijalbo, Lucía; Fernandez-Pascual, Mercedes; García-Seco, Daniel; Gutierrez-Mañero, Francisco Javier; Lucas, Jose Antonio

    2013-09-15

    In this work we assess the capacity of maize (Zea mays) plants to phytoremediate spent metal working fluids (MWFs) and its effects on photosynthesis and ultrastructure of mesophyll and root cells. A corn-esparto fibre system patented by us has been used to phytoremediate MWFs in hydroponic culture. Furthermore, a plant growth promoting rhizobacteria (PGPR) has been used to improve the process. The results show that this system is capable of significantly reducing the chemical oxygen demand, under local legislation limits. However, plant systems are really damaged, mainly its photosynthetic system, as shown by the photosynthetical parameters. Nevertheless, strain inoculated improves these parameters, especially Hill reaction. The ultrastructure of photosynthetic apparatus was also affected. Chloroplast number decreased and becomes degraded in the mesophyll of MWFs treated plants. In some cases even plasmolysis of chloroplast membrane was detected. Early senescence symptoms were detected in root ultrastructural study. Severe cellular damage was observed in the parenchymal root cells of plants grown with MWFs, while vascular bundles cell remained unchanged. It seems that the inoculation minimises the damage originated by the MWFs pollutants, appearing as less degenerative organelles and higher chloroplast number than in non-inoculated ones. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Deletion of Type 3 Adenylyl Cyclase Perturbs the Postnatal Maturation of Olfactory Sensory Neurons and Olfactory Cilium Ultrastructure in Mice

    Science.gov (United States)

    Zhang, Zhe; Yang, Dong; Zhang, Mengdi; Zhu, Ning; Zhou, Yanfen; Storm, Daniel R.; Wang, Zhenshan

    2017-01-01

    Type 3 adenylyl cyclase (Adcy3) is localized to the cilia of olfactory sensory neurons (OSNs) and is an essential component of the olfactory cyclic adenosine monophosphate (cAMP) signaling pathway. Although the role of this enzyme in odor detection and axonal projection in OSNs was previously characterized, researchers will still have to determine its function in the maturation of postnatal OSNs and olfactory cilium ultrastructure. Previous studies on newborns showed that the anatomic structure of the main olfactory epithelium (MOE) of Adcy3 knockout mice (Adcy3-/-) is indistinguishable from that of their wild-type littermates (Adcy3+/+), whereas the architecture and associated composition of MOE are relatively underdeveloped at this early age. The full effects of sensory deprivation on OSNs may not also be exhibited in such age. In the present study, following a comparison of postnatal OSNs in seven-, 30-, and 90-day-old Adcy3-/- mice and wild-type controls (Adcy3+/+), we observed that the absence of Adcy3 leads to cumulative defects in the maturation of OSNs. Upon aging, Adcy3-/- OSNs exhibited increase in immature cells and reduction in mature cells along with elevated apoptosis levels. The density and ultrastructure of Adcy3-/- cilia were also disrupted in mice upon aging. Collectively, our results reveal an indispensable role of Adcy3 in postnatal maturation of OSNs and maintenance of olfactory cilium ultrastructure in mice through adulthood. PMID:28154525

  19. Distribution of Luminosity, Gas, and Stellar Populations in Local Luminous Infrared Galaxies as a Function of Merger Stage

    Science.gov (United States)

    Larson, Kirsten L.

    Luminous infrared galaxies (LIRGs) are galaxies where intense infrared emission is driven by star formation and active galactic nuclei. In the local universe it is clear that many LIRGs are major mergers of gas rich spiral galaxies. I have performed a careful visual classification of local (z 1011:5Lsun are merging galaxies, while below this luminosity threshold, minor mergers and secular processes dominate. The mean molecular gas fraction ( MGF = MH2=(M* + MH2)) has an average value of 18+/-2% for non-interacting and early stage major merger LIRGs, which increases to 33±3% for intermediate stage major merger LIRGs. This is consistent with the hypotheses that during the early-mid stages of major mergers, atomic gas (H I) at large galactocentric radii is swept inward where it is converted into molecular gas (H2). The interactions also drive star formation throughout the galaxy as is evident by the blue B -- I color for LIRGs at every merger stage. Late stage mergers show a reddening in their nuclear 2 kpc region, presumably also from increase in nuclear gas and dust as the galaxy nuclei coalesce. Using deep Spitzer 3.6 and 4.5 mum imaging, I find that these interactions form tidal tails and debris that extend out to 80 kpc from the galaxy nuclei. This large scale tidal debris builds up over the course of a major merger and forms up-bending infrared surface brightness profiles. I further investigate the utility of automated morphology parameters and present a refined surface brightness method for gini, M20, and concentration indices. With this new method the M20 parameter correlates with merger stage and, in combination with gini and concentration, provides a more reliable automated separation between interacting and non-interacting galaxies than previous schemes.

  20. Regional and Local Controls on the Distribution of Geothermal Systems in the Great Basin, Western United States

    Science.gov (United States)

    Coolbaugh, M. F.; Blewitt, G.; Faulds, J. E.; Kreemer, C. W.

    2005-12-01

    In the Great Basin (GB) of the western United States, geothermal systems with reservoir temperatures in excess of 150 C can be classified into two main categories (magmatic and amagmatic) according to the presence or absence of shallow magmatic heat sources. Magmatic systems are restricted to the margins of the GB where they are closely associated with Quaternary silicic volcanic rocks, whereas amagmatic systems occur over a large portion of the Great Basin interior and are not spatially associated with young silicic volcanism. A tabulation of temperature gradients for known geothermal systems in the world confirms research by others indicating that both magmatic and amagmatic systems occur within areas of high temperature gradients and high heat flow. However, high heat flow alone is not sufficient to explain the abundance of high-temperature geothermal activity in the GB interior. While the distribution of favorable host rocks likely plays a role, active crustal tectonics appears instrumental in explaining patterns of geothermal activity. At a detailed scale, Quaternary faults control the location of most geothermal systems in the GB. However, hundreds of Quaternary faults are distributed throughout the GB, and most do not host high-temperature geothermal resources. Spatial statistical analysis demonstrates that high-temperature geothermal systems (more than 150 C) are preferentially associated with NE-striking Quaternary faults, which in turn are oriented roughly perpendicular to the current direction of crustal extension in the western GB. Maps of active crustal extension rates in the GB, derived from Global Positioning System (GPS) velocity measurements and estimated slip rates on Quaternary faults, correlate well with the distribution of high-temperature geothermal systems and help explain why some faults with lower slip rates or unfavorable orientations don't host geothermal activity. Many geothermal systems in the GB occur in a broad transitional region