117,328 research outputs found
Caratterizzazione e interazione di pentraxina 3 e inter -alpha-trypsin-inhibitor nella matrice del cumulo ooforo
No full textE' stato precedentemente dimostrato che la sintesi di PTX3 è stimolata nelle cellule del cumulo durante il periodo preovulatorio ed è essenziale per l'organizzazione dell'acido ialuronico e l'espansione del complesso ovocito-cellule del cumulo (COC). Il presente studio mostra che, sebbene tumor necrosis factor α and interleukin-1β siano capaci di indurre PTX3 in molti tipi cellulari e sebbene queste citochine siano prodotte nel follicolo, la prima non ha nessun effetto sulla sintesi di PTX3 e sull'espansione di COC coltivati in vitro e la seconda è soltanto parzialmente efficace, suggerendo un ruolo marginale di queste citochine in vivo.
Inoltre questa ricerca mostra che il dominio N terminale di PTX3 ricombinante, così come la
molecola intera, è capace di organizzare l'HA nella matrice e ripristinare la normale espansione in cumuli PTX3 -/-, mentre il dominio C terminale è completamente inefficace nello svolgere tale funzione. Abbiamo anche dimostrato che un anticorpo monoclonale che riconosce il dominio N terminale di PTX3 neutralizza l'azione dell'intera molecola ricombinante in cumuli PTX3 -/-. Questi risultati evidenziano che la funzione strutturale di PTX3 nella matrice del cumulo dipende esclusivamente dalla regione N terminale, che non è correlata a nessun altra proteina conosciuta.
Noi avevamo precedentemente riportato che PTX3 è in grado di legare TSG6, una proteina
sintetizzata dalle cellule del cumulo, capace di legare l'HA. Attraverso esperimenti di
coimmunoprecipitazione abbiamo dimostrato che PTX3 lega anche le catene pesanti dell'IαI,
che sono covalentemente legate all'HA. I risultati suggeriscono che queste molecole
cooperino nello stabilizzare la matrice formando dei ponti trasversali tra le catene di HA.It has been shown that PTX3 synthesis is stimulated in cumulus cell during the preovulatory period and is essential for hyaluronan (HA) organization and expansion by cumulus cell-oocyte complexes (COC). In the present study we show that, although tumor necrosis factor- and interleukin-1 are able to induce PTX3 in several cell types and these cytochines are produced in the follicle, the former is ineffective and the latter is a poor inducer of PTX3 synthesis and expansion in COC cultured in vitro, suggesting a marginal role of these cytochines in vivo.
We also show that recombinant N terminal PTX3 domain, as the full length molecule, is able to organize HA in the matrix and restore normal expansion in PTX3 -/- COC culture, while recombinant C terminal PTX3 domain is not. In addition, an anti-PTX3 monoclonal antibody binding to N terminal region neutralizes the action of full length recombinant PTX3 in PTX3
-/- COC culture. These results demonstrate that the matrix structural function of PTX3 is exclusively dependent on the N terminal region, that is unrelated to other known proteins.
We have previously reported that PTX3 is able to bind TSG-6, an HA binding protein synthesized by cumulus cells. By coimmunoprecipation studies and binding assay we now show that PTX3 also binds to I heavy chains, which are covalently linked to HA. These findings suggest a cooperative effect of these molecules on matrix stability by the formation of cross linking among HA strains
Extraordinary blowing snow transport events in East Antarctica
No full textIn the convergence slope/coastal areas of Antarctica, a large fraction of snow is continuously eroded and exported by wind to the atmosphere and into the ocean. Snow transport observations from instruments and satellite images were acquired at the wind convergence zone of Terra Nova Bay (East Antarctica) throughout 2006 and 2007. Snow transport features are well-distinguished in satellite images and can extend vertically up to 200 m as first-order quantitatively estimated by driftometer sensor FlowCaptTM. Maximum snow transportation occurs in the fall and winter seasons. Snow transportation (drift/blowing) was recorded for ~80% of the time, and 20% of time recorded, the flux is >10-2 kg m-2 s-1 with particle density increasing with height. Cumulative snow transportation is ~4 orders of magnitude higher than snow precipitation at the site. An increase in wind speed and transportation (~30%) was observed in 2007, which is in agreement with a reduction in observed snow accumulation. Extensive presence of ablation surface (blue ice and wind crust) upwind and downwind of the measurement site suggest that the combine processes of blowing snow sublimation and snow transport remove up to 50% of the precipitation in the coastal and slope convergence area. These phenomena represent a major negative effect on the snow accumulation, and they are not sufficiently taken into account in studies of surface mass balance. The observed wind-driven ablation explains the inconsistency between atmospheric model precipitation and measured snow accumulation value. © 2009 The Author(s)
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Square Dancing with the Stars to Enhance Dynamic Hirschman Linkages?
No full textIn this Presidential Address, the author takes the reader on a reconnaissance of his life and time as a regional scientist. He points out scenery he found scintillating along the way, hoping that some may pick up the banner and chew on a few of the ideas for a while. He suggests a revisit to Albert O. Hirschman’s notion of key sectors and more empirical analysis related to Marcus Berliant’s and Masahisa Fujita’s notion of knowledge creation and transfer.Presidential Address, San Antonio, Texas, March 29, 2014 (53rd Meetings of the Southern Regional Science Association
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Letter from unknown writer to Jesse L. Boyce
No full textLetter to Jesse L. Boyce from unknown author (possibly Jack) about the investigation into the powder magazine located in the Grand Canyon. Some personal news is included in the letter such as the writer's marriage to the daughter of C.A. Taylor, former Supervisor of Cochise County
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Biogenic aerosol in central East Antarctic Plateau as a proxy for the ocean-atmosphere interaction in the Southern Ocean
No full textTen years of data of biogenic aerosol (methane sulfonic acid, MSA, and non-sea salt sulfate, nssSO42−) collected at Concordia Station in the East Antarctic plateau (75° 06′ S, 123° 20′ E) are interpreted as a function of the Southern Annular Mode (SAM), Chlorophyll-a concentration (Chl-a; a proxy for phytoplankton biomass), sea ice extent and area. It is possible to draw three different scenarios that link these parameters in early, middle, and late summer. In early summer, the biogenic aerosol is significantly correlated to sea ice retreats through the phytoplankton biomass increases. Chl-a shows a significant correlation with nssSO42− in the finest fraction (< 1 μm). In contrast, only Chl-a in West Pacific and Indian Ocean sectors correlates with MSA in the coarse fraction. The transport routes towards the inner Antarctic plateau and aerosol formation processes could explain the different correlation patterns of the two compounds both resulting from the DMS oxidation. In mid-summer, Chl-a concentrations are at the maximum and are not related to sea ice melting. Due to the complexity of transport processes of air masses towards the Antarctic plateau, the MSA concentrations are low and not related to Chl-a concentration. In late summer, MSA and nssSO42− present the highest concentrations in their submicrometric aerosol fraction, and both are significantly correlated with Chl-a but not with the sea ice. In early and mid-summer, the enhanced efficiency of transport processes from all the surrounding oceanic sectors with air masses traveling at low elevation can explain the highest concentrations of nssSO42− and especially MSA. Finally, considering the entire time series, MSA shows significant year-to-year variability. This variability is significantly correlated with SAM but with a different time lag in early (0-month lag) and late summer (4-months lag). This correlation likely occurs through the effect of the SAM on phytoplankton blooms
Sarah L. Blum Author Visit - Warrior Nurse: PTSD and Healing
No full textHear Sarah L. Blum, author of Women Under Fire: Abuse in the Military, discuss her newest book, Warrior Nurse: PTSD and Healing followed by a Q&A and book signing.
Sarah L. Blum is a decorated Vietnam veteran who served as an operating room nurse during the intense fighting of 1967. In recognition of her service, she was awarded the Army Commendation Medal.
Sponsored by CWU Veterans Center and CWU Libraries.https://digitalcommons.cwu.edu/libraryevents/1252/thumbnail.jp
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