1,058 research outputs found
Ries impact crater sedimentary conglomerates: Sedimentary particle 'impact pre-processing', transport distances and provenance, and implications for Gale crater conglomerates, Mars
No full textTerrestrial impact cratering events produce anomalous rock fragmentation and alteration, and form sedimentary basins that are out of equilibrium with the local geomorphological environment. Assessement of their initial deposits, crater erosion and infilling, lacustrine environments and biology can provide important insights into similar features on Mars. Here we report on fluviodeltaic conglomerates associated with the 26km diameter Miocene Ries impact structure (target: sediments overlying crystalline basement) with respect to shock features, grain size distribution, roundness, and potential parent rocks (provenance). The poorly sorted conglomerates form coarsening-upwards cycles associated with a delta-mouth bar system, with subangular to subrounded pebbles derived from crystalline rock impact breccia deposits. Pebbles comprise a wide range of lithologies and states ranging from fresh and solid to intensively impact-fractured, friable crystalline rocks, including shatter cones. Shocked quartz grains, however, are restricted to the sand fraction. The latter observation points to suevite as an additional, but subordinate source of the conglomerates. Granulometric analysis indicates that, in contrast to being derived from weathering of bedrock, impact brecciation of the parent crystalline rocks generated the initial grain size distribution of the conglomerates (i.e., preprocessing). This concept of “impact preprocessing” helped to defne the provenance, the post-impact sedimentologic history and the sediment transport distances of the conglomerates. Post-impact fluvial transport leads to the outwash of fine fractions into the prodelta subenvironment, and an increase in roundness and mean diameter in the residual conglomerates (i.e. hydraulic sorting). On the basis of the characteristics of the ejecta deposits and the present-day locations and occurrences of crystalline rock impact breccias and blocks in the northwestern Ries crater segment analyzed, a transport distance of less than 3.5km is derived for these impact-preprocessed conglomerates. Reconstruction of the initial distribution and composition of the primary ejecta layer indicates that the conglomerates composed solely of crystalline rock had a maximum transport distance less than 6.5km, i.e., within the closed basin of the Ries impact structure. In contrast to traditional interpretations of conglomerates, requiring long transport distances from bedrock source regions to deposition to ensure sufficient rounding and sorting, the rounding and sorting associated with these short transport distances are explained by preprocessing of parent rocks by impact brecciation and enhanced susceptibility to abrasion. Consequently, transport distances of conglomeratic fragments associated with impact craters, such as Gale crater on Mars, are likely to have been only a few kilometers, and derived from nearby ejecta, most likely from the inner crater walls. This Ries crater-based preprocessing and transport model implies that the unusual Gale crater conglomeratic fragments are likely to represent the immediate target material excavated by the Gale cratering event, rather than fragments transported laterally from greater distances outside the crater
Is Hondius or Schultz the Author of the Portrait Study of Karol Ferdynand Vasa?
No full textStanding face to face with a civil war and a danger of destabilisation of the country, King Jan Kazimierz decided that a change in his official iconography was so important that almost immediately after succeeding to the throne (1648) he reorganised his artistic court. In 1649 the outstanding portrait painter Daniel Schultz was employed and he was charged with the task of creating the image of the monarch that would be suitable for the requirements of the new authorities' propaganda and at the same time would meet the society's expectations. (It was for the same reasons that the great Roman sculptor Francesco Rossi was brought to Poland in 1651.) Of the former group of artists among others Willem Hondius was kept – as it turns out not a very able draughtsman, but a good copper engraver, who proved useful in his earlier works for the royal court, and now was indispensable for putting into effect Jan Kazimierz's propaganda aims.
Analysing the portrait study of the King's brother, Karol Ferdynand Vasa (1650) from the collection of the National Museum in Gdańsk (Fig. 1), Gajewski finds in it both new principles of the art of portrait introduced into the official image by Daniel Schultz, and the artistic qualities characteristic of Schultz's painting (Fig. 2, 3). Gajewski challenges the proposition put forward in the literature of the subject saying that it is Hondius who is the author of the portrait study of Karol Ferdynand, and he claims that the author of the study is Schultz. He also thinks that the study is Schultz's drawing for the graphic portrait of Karol Ferdynand Vasa that was not used. The portrait was made (1650) by Hondius after another pattern by Daniel Schultz (Fig. 4)
Real-Time Monitoring of Apoptosis by Caspase-3-Like Protease Induced FRET Reduction Triggered by Amyloid Aggregation
No full textAmyloid formation is cytotoxic and can activate the caspase cascade. Here, we monitor caspase-3-like activity as reduction of fluorescence resonance energy transfer (FRET) using the contstruct pFRET2-DEVD containing enhanced cyan fluorescent protin (EYFP) linked by the caspase-3 specific cleavage site residues DEVD. Beta-TC-6 cells were transfected, and the fluoorescence was measured at 440 nm excitation and 535 nm (EYFP) and 480 nm (ECFP) emission wavelength. Cells were incubated with recombinant pro lset Amyloid Polypeptide (rec prolAPP) or the processing metabolites of prolAPP; the N-terminal flanking peptide withIAPP (recN+IAPP); IAPP with the C-terminal flanking peptied (recIAPP+C) and lslet Amyloid Polypeptide (recIAPP). Peptides were added in solubilized from (50 mu M) or as performed amyloid-like fibrils, or as a combination of these. FRET was measured and incubation with a mixture of solubilized peptide and performed fibrils resulted in loss of FRET and apoptosis was determined to occurein cells incubated with recproIAPP (49%), recN+IAPP (46%), recIAPP (72%) and recIAPP+C (59%). These results show that proIAPP and the processing intermediates reside the same cell toxic capacity as IAPP, and they can all have a central role in the reduction of beta-cell number in type 2 diabetes.Original Publication:Johan F Paulsson, Sebastian Schultz, Martin Kohler, Ingo Leibiger, Per-Olof Berggren and Gunilla Westermark, Real-Time Monitoring of Apoptosis by Caspase-3-Like Protease Induced FRET Reduction Triggered by Amyloid Aggregation, 2008, EXPERIMENTAL DIABETES RESEARCH, (2008), 865850.http://dx.doi.org/10.1155/2008/865850Copyright: Author
Analysis and validation of a scaled, launch-vehicle-like composite cylinder under axial compression
No full textLaunch vehicle structures, such as payload adapters and interstages, are increasingly designed and constructed using composite materials due to their high stiffness- and strength-to-weight ratios. Therefore, it is important to develop a validated finite element modeling methodology for designing and analyzing composite launch-vehicle shell structures. This can be achieved, in part, by correlating high-fidelity numerical models with test data. Buckling is often an important failure mode for cylindrical shells, and the buckling response of such structures is also often quite sensitive to imperfections in geometry and loading. Hence, it is crucial to understand the model parameters and details required to accurately predict the buckling load and behavior of composite cylindrical shells, especially if the shell is buckling critical. The inclusion of as-built features, such as radial imperfections, thickness variations, and loading imperfections can help improve the correlation between test and analysis. To demonstrate such an approach, a validated modeling methodology that was used to predict the buckling behavior of a scaled component for a launch-vehicle-like structure is presented, and results from the model are compared with experimental results. The modeling approach presented herein was used to successfully predict the buckling behavior.Aerospace Structures & Computational Mechanic
Variable-energy positron beam study of arsenic diffusion in poly-silicon
No full textThe positron beam technique is shown to be a sensitive indicator of the presence of arsenic within the grain boundaries of poly-silicon. Variable-energy positron beam and secondary-ion mass spectrometry studies have been performed on As+-implanted pre-amorphized Si samples as a function of dose and rapid thermal anneal temperature. Positron trapping within negatively-charged grain boundaries of the recrystallized poly-Si is observed, resulting in a similar to 2% elevation in the Doppler-broadening S lineshape parameter value. Infusion of As+-ions into the grain boundaries passivates the charge and reduces their specific positron-trapping rate.PT: J; CR: AERS GC, 1991, POSITRON BEAMS SOLIE, P162 ASOKAKUMAR P, 1993, NUCL INSTRUM METH B, V74, P89 BOUSETTA A, 1991, NUCL INSTRUM METH B, V55, P565 DANNEFAER S, 1987, PHYS STATUS SOLIDI A, V102, P481 DANNEFAER S, 1989, J APPL PHYS, V66, P3526 DLUBEK G, 1987, PHYS STATUS SOLIDI A, V102, P443 FLYNN CP, 1992, POINT DEFECTS DIFFUS GANIN E, 1989, APPL PHYS LETT, V54, P2127 HAKVOORT RA, 1992, MATER SCI FORUM, V105, P1391 HAKVOORT RA, 1993, THESIS DELFT U TECHN JACKMAN TE, 1989, APPL PHYS A-SOLID, V49, P335 KALISH R, 1984, APPL PHYS LETT, V44, P107 KEINONEN J, 1988, PHYS REV B, V37, P8269 LEO PH, 1981, PHYS STATUS SOLIDI B, V108, K145 LOMBARDO S, 1994, J APPL PHYS, V75, P345 MAKINEN J, 1990, J APPL PHYS, V67, P990 MITCHELL IV, 1991, POSITRON BEAMS SOLID, P121 NASU H, 1987, YOGYO-KYOKAI-SHI, V95, P5 NIELSEN B, 1987, APPL PHYS LETT, V51, P1022 NIELSEN B, 1991, PHYS REV B, V44, P1812 SCHULTZ PJ, 1988, PHYS REV LETT, V61, P187 SCHULTZ PJ, 1988, REV MOD PHYS, V60, P701 SEIDEL TE, 1991, NUCL INSTRUM METH B, V55, P17 SIMPSON PJ, 1991, POSITRON BEAMS SOLID, P125 TAKAI M, 1989, NUCL INSTRUM METH B, V39, P352 TANDBERG E, 1989, CAN J PHYS, V67, P275 VANDERDRIFT A, 1967, PHILIPS RES REP, V22, P267; NR: 27; TC: 0; J9: APPL SURF SCI; PG: 6; GA: QD950Source type: Electronic(1
Bruno Schultz, Self-Portrait, 1933; Back of postcard
No full textBruno Schultz, Self-Portrait, 1933; Back of postcard; Black and white reproduction of a self portrait by Polish Jewish author and artist, Bruno Schulz (1892-1942). Below the reproduction is the artist’s signature. Back: A caption in Polish, English and German reads: “RYSUNKI BRUNONA SCHULZA Z KOLEKCJI MUZEUM LITERATURY W WARSZAWIE 12 REPRODUKCJI” – “DRAWINGS OF BRUNO SCHULZ FROM THE COLLECTION OF THE MUSEUM OF LITERATURE, WARSAW 12 REPRODUCTIONS” – “ZEICHUNGEN VON BRUNO SCHULZ AUS KOLLEKTION DIE LITERATURMUSEUM, WARSCHAU 12 REPRODUKTIONEN”. A second caption in Polish, English and German reads: “NA OKŁADCE: AUTOPORTRET, OK. 1933” - “ON THE COVER: SELF - PORTRAIT, C. 1933” – “AUF DEM BAND: SELBSTBILDNIS, UM 1933”. Below, a caption in Polish reads: “WYDAWNICTWO KRZYSZTOFA KWASKOWSKIEGO, ŁÓDŹ - WARSZA 29 JUL. 862653 OPRACOWANIE GRAFICZNE - MICHAŁ KRĘOLEWICZ”
Tagging of Biomedical Articles on CiteULike: A Comparison of User, Author and Professional Indexing
No full textThis paper examines the context of online indexing from the viewpoint of three different groups: users, authors, and professional indexers. User tags, author keywords and descriptors were collected from academic journal articles, which were both indexed in Pubmed and tagged on CiteULike, and analysed. Descriptive statistics, informetric measures, and thesaural term comparison shows that there are important differences in the use of keywords between the three groups in addition to similarities which can be used to enhance support for search and browse. While tags and author keywords were found that matched descriptors exactly, other terms which did not match but provided important expansion to the indexing lexicon were found. These additional terms could be used to enhance support for searching and browsing in article databases as well as to provide invaluable data for entry vocabulary and emergent terminology for regular updates to indexing systems. Additionally, the study suggests that tags support organisation by association to task, projects and subject while making important connections to traditional systems which classify into subject categories
Bruno Schultz, Self-Portrait, 1933; Back of postcard
No full textBruno Schultz, Self-Portrait, 1933; Back of postcard; Black and white reproduction of a self portrait by Polish Jewish author and artist, Bruno Schulz (1892-1942). Below the reproduction is the artist’s signature. Back: A caption in Polish, English and German reads: “RYSUNKI BRUNONA SCHULZA Z KOLEKCJI MUZEUM LITERATURY W WARSZAWIE 12 REPRODUKCJI” – “DRAWINGS OF BRUNO SCHULZ FROM THE COLLECTION OF THE MUSEUM OF LITERATURE, WARSAW 12 REPRODUCTIONS” – “ZEICHUNGEN VON BRUNO SCHULZ AUS KOLLEKTION DIE LITERATURMUSEUM, WARSCHAU 12 REPRODUKTIONEN”. A second caption in Polish, English and German reads: “NA OKŁADCE: AUTOPORTRET, OK. 1933” - “ON THE COVER: SELF - PORTRAIT, C. 1933” – “AUF DEM BAND: SELBSTBILDNIS, UM 1933”. Below, a caption in Polish reads: “WYDAWNICTWO KRZYSZTOFA KWASKOWSKIEGO, ŁÓDŹ - WARSZA 29 JUL. 862653 OPRACOWANIE GRAFICZNE - MICHAŁ KRĘOLEWICZ”
Armadilloniscus ninae Schultz 1984
No full textArmadilloniscus ninae Schultz, 1984 Figs 1, 2F, 13–14 Armadilloniscus ninae Schultz, 1984: 4, figs 1–2. Material examined COLOMBIA – Bolívar, Cartagena de Indias, Islas del Rosario, Isla Grande • 1 ♂ (parts in micropreparations); Paraíso Secreto; 10°10′15.9″ N, 75°44′38.8″ W; 24 Nov. 2017; C.M. López- Orozco leg.; CUDC-CRU 212 • 1 ♂, 4 ♀♀; same collection data as for preceding; CUDC-CRU 214 • 21 ♂♂, 61 ♀♀; same locality as for preceding; 4 Apr. 2018; C.M. López-Orozco, R. Borja-Arrieta and K. Meza leg.; CUDC-CRU 213 • 3 ♀♀; same locality as for preceding; 6 Sep. 2017; C.M. López- Orozco leg.; CUDC-CRU 215 • 1 ♂, 6 ♀♀ (one with parts in micropreparations); Caño Ratón; 10°10′33.4″ N, 75°44′52.4″ W; 24 Nov. 2017; C.M. López-Orozco leg.; CUDC-CRU 216 • 5 ♀♀; 10°10′44.91″ N, 75°44′53.01″ W; same collection data as for preceding; CUDC-CRU 217. CUBA – Cayo Piedras del Norte, Varadero • 2 ♂♂, 2 ♀♀; 8 Aug. 1985; A. Poggesi leg.; MZUF 1824. Redescription BODY. Color pale brown; cephalon, antennae, epimera of pereonites 1–7, epimera of pleonites 1–5 and uropod protopods more pigmented; pereon and pleon with median and paramedian region more depigmented (Fig. 2F). Body elongated and elliptical-shaped (Fig. 13A). Dorsal surface bearing elongated scale-setae (Fig. 13B). Cephalon and pereon covered with small tubercles (Fig. 13A, C–D): cephalon bearing six tubercles in two rows, anterior row with two and posterior row with four; pereonites 1–7 with one row of 8 tubercles. CEPHALON. Lateral lobes well developed and directed outwards, median lobe triangular, slightly surpassing distal margin of lateral lobes, frontal and suprantennal lines absent; eyes consisting of 5 ommatidia (Fig. 13C–D). PLEON. Outline continuous with that of pereonite 7, epimera of pleonites 3–5 rectangular (Fig. 13A, E). Telson (Fig. 13E) triangular, wider than long, lateral margins almost straight, broadly rounded apex. ANTENNULA. Composed of two articles, second article bearing many lateral setae, distal margin bearing one flagellar seta and two aesthetascs (Fig. 13F). ANTENNA. When extended posteriorly slightly surpassing pereonite 1, flagellum of four articles (Fig. 13G). BUCCAL PIECES. As in Armadilloniscus luisi sp. nov. UROPOD. Protopod enlarged with distal margin slightly rounded, exopod not surpassing protopod, endopod longer than exopod (Fig. 13E). PEREOPODS. Pereopods 1–7 stout, merus to propodus bearing sparse setae on sternal margin, carpus 1 with strong distal seta bearing long sensilla, dactylus with elongated and digitform ungual seta, dactylar seta elongated, apically cleft and plumose. Male PEREOPODS 1 AND 7. Without any sexual modifications (Fig. 14A–B). GENITAL PAPILLA. Ventral shield stout triangular, papilla rounded at apex, bearing small setae (Fig. 14C). PLEOPODS. Pleopod 1 (Fig. 14D) exopod ovoid, wider than long; endopod stout, three times as long as exopod, apical portion slightly bent inwards. Pleopod 2 (Fig. 14E) exopod ovoid, wider than long; endopod with flagelliform distal article. Exopods of pleopods 3–5 as in Fig. 14F–H. Remarks Schultz (1984) described A. ninae from San Pedro beach, Ambergris Cay, Belize. Comparing Shultz’s description with the specimens examined here, it was possible to observe that almost all characters mentioned, including the pale dorsal pigmentation, are quite similar. However, Schultz (1984) mentioned that A. ninae has eyes composed of 14 ommatidia and antennula with three articles, and herein the specimens showed the eyes composed of 5 ommatidia and antennula of two articles. Most probably, the author misinterpreted the composition of the eyes of this species, since the illustrations of the cephalon clearly show a smaller number. The same statement can be applied to the antennula. In general, within Oniscidea, the composition of the antennula does not vary within the genera, with just few exceptions (see Schmidt 2002, 2003). Moreover, analyzing other representatives of Armadilloniscus, it is possible to observe that the antennula is always composed of two articles (see Taiti & Ferrara 1989; Kwon & Wang 1996). Therefore, we identify our specimens as A. ninae. Distribution This species was previously recorded only from San Pedro beach, Ambergris Cay, Belize (Schultz 1984). First record for Colombia and Cuba.Published as part of López-Orozco, Carlos Mario, Carpio-Díaz, Yesenia M., Borja-Arrieta, Ricardo, Navas-S, Gabriel R., Campos-Filho, Ivanklin Soares, Taiti, Stefano, Mateos, Mariana, Olazaran, Alexandra, Caballero, Isabel C., Jotty, Karick, Gómez-Estrada, Harold & Hurtado, Luis A., 2022, A glimpse into a remarkable unknown diversity of oniscideans along the Caribbean coasts revealed on a tiny island, pp. 1-50 in European Journal of Taxonomy 793 on pages 26-29, DOI: 10.5852/ejt.2022.793.1643, http://zenodo.org/record/603789
Amyloid Deposition in Transplanted Human Pancreatic Islets : A Conceivable Cause of Their Long-Term Failure
No full textFollowing the encouraging report of the Edmonton group, there was a rejuvenation of the islet transplantation field. After that, more pessimistic views spread when long-term results of the clinical outcome were published. A progressive loss of the beta-cell function meant that almost all patients were back on insulin therapy after 5 years. More than 10 years ago, we demonstrated that amyloid deposits rapidly formed in human islets and in mouse islets transgenic for human IAPP when grafted into nude mice. It is, therefore, conceivable to consider amyloid formation as one potential candidate for the long-term failure. The present paper reviews attempts in our laboratories to elucidate the dynamics of and mechanisms behind the formation of amyloid in transplanted islets with special emphasis on the impact of long-term hyperglycemia.Original Publication:Arne Andersson, Sara Bohman, L A Hakan Borg, Johan Paulsson, Sebastian Schultz, Gunilla Westermark and Per Westermark, Amyloid Deposition in Transplanted Human Pancreatic Islets: A Conceivable Cause of Their Long-Term Failure, 2008, EXPERIMENTAL DIABETES RESEARCH, (2008), 562985.http://dx.doi.org/10.1155/2008/562985Copyright: Author
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