1,520 research outputs found

    Temperature - pressure phase diagram of CeCoSi: Pressure induced high-temperature phase

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    We have studied the temperature-pressure phase diagram of CeCoSi by electrical-resistivity experiments under pressure. Our measurements revealed a very unusual phase diagram. While at low pressures no dramatic changes and only a slight shift of the Ne\'{e}l temperature TNT_N (≈10\approx 10 K) are observed, at about 1.45 GPa a sharp and large anomaly, indicative of the opening of a spin-density-wave (SDW) gap, appears at a comparatively high temperature TS≈38T_S \approx 38 K. With further increasing pressure TST_S shifts rapidly to low temperatures and disappears at about 2.15 GPa, likely continuously in a quantum critical point, but without evidence for superconductivity. Even more surprisingly, we observed a clear shift of TST_S to higher temperatures upon applying a magnetic field. We discuss two possible origins for TST_S, either magnetic ordering of Co or a meta-orbital type of transition of Ce.Comment: 6 pages, 5 figure

    Benign Bilateral Adenomyoepithelioma of the Mammary Gland in a Ring-tailed Lemur (Lemur catta)

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    Naturally occurring mammary tumours are uncommon in prosimians. A 20-year-old female ring-tailed lemur (Lemur catta) developed bilateral enlargement of the mammary glands. Surgical removal revealed that both masses were comprised of multiple nodules and cystic areas that entirely replaced the normal glands. Histologically, a benign neoplastic biphasic cellular proliferation, composed of luminal–epithelial and basal–myoepithelial components, was identified. Immunohistochemical analysis for expression of cytokeratin (CK) AE1/AE3, CK7, CK5 + 8, CK14, vimentin, p63 and 14-3-3σ highlighted the biphasic nature of the neoplasm. A low mitotic count, low Ki67 labelling index, expression of oestrogen receptor-α, lack of expression of human epidermal growth factor receptor and a 3-year disease-free period without recurrence supported the benign nature of the tumour. Macroscopically, histologically and immunohistochemically this neoplasm resembled benign adenomyoepithelioma of the breast in women. This is the first complete report of a naturally occurring mammary tumour in a ring-tailed lemur

    Multi-Segment Direct Inject nano-ESI-LTQ-FT-ICR-MS/MS For Protein Identification

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    Reversed phase high performance liquid chromatography (HPLC) interfaced to electrospray tandem mass spectrometry (MS/MS) is commonly used for the identification of peptides from proteolytically cleaved proteins embedded in a polyacrylamide gel matrix as well as for metabolomics screening. HPLC separations are time consuming (30-60 min average), costly (columns and mobile phase reagents), and carry the risk of column carry over between samples. The use of a chip-based nano-ESI platform (Advion NanoMate) based on replaceable nano-tips for sample introduction eliminates sample cross-contamination, provides unchanging sample matrix, and enhances spray stability with attendant increases in reproducibility. Recent papers have established direct infusion nano-ESI-MS/MS utilizing the NanoMate for protein identification of gel spots based on full range MS scans with data dependent MS/MS. In a full range scan, discontinuous ion suppression due to sample matrix can impair identification of putative mass features of interest in both the proteomic and metabolomic workflows. In the current study, an extension of an established direct inject nano-ESI-MS/MS method is described that utilizes the mass filtering capability of an ion-trap for ion packet separation into four narrow mass ranges (50 amu overlap) with segment specific dynamic data dependent peak inclusion for MS/MS fragmentation (total acquisition time of 3 minutes). Comparison of this method with a more traditional nanoLC-MS/MS based protocol utilizing solvent/sample stream splitting to achieve nanoflow demonstrated comparable results for protein identification from polyacrylamide gel matrices. The advantages of this method include full automation, lack of cross-contamination, low cost, and high throughput

    Leishmania (Viannia) spp. dissemination and tissue tropism in naturally infected dogs (Canis familiaris).

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    First evidence is presented for Leishmania (Viannia) spp. dissemination and tissue tropism in the domestic dog. Using PCR and histology, parasites were detected in the conjunctiva, lung, lymph nodes and ovaries of 2 naturally infected Peruvian dogs. The detection of parasites in the blood indicates that parasite dissemination to those organs may have been haematogenous

    Seismic imaging and attribute analysis of Chicxulub Crater central sector, YucatĂĄn Platform, Gulf of Mexico

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    Chicxulub Crater, formed ~66Ma ago by an asteroid impact on the southern Gulf of Mexico, is the best preserved of the three large multi-ring basins in the terrestrial record. The crater structure is characterized by a semi-circular concentric ring pattern, marking the crater basin, peak ring, terrace zone and basement uplift. Analysis of a grid of 19 seismic reflection profiles using seismic attributes, marker horizons, contour surfaces and 3-D views is used to investigate the stratigraphy of the central zone. We used interactive software and routine applications to map the impact breccias, breccia-carbonate contact and post-impact carbonates. Four horizons marked by high-amplitude reflectors representing high-impedance contrasts were identified and laterally correlated in the seismic images. Complex trace attribute analysis was applied for petrophysical characterization. Surface contour maps of base and top of stratigraphic packages were constructed, which mapped the impactites and post- and pre-impact carbonate stratigraphy. Basin floor, marked by the contact between the impact breccias and overlying carbonates is shown by laterally discontinuous high-amplitude reflectors. Discontinuous scattered reflectors interpreted as the upper breccias beneath the crater floor, have an average thickness of ~300msm. The Paleogene sedimentary units are characterized by multiple reflectors with lateral continuity, which contrast with the seismic response of underlying breccias. The basal Paleocene sediments follow the basin floor relief. Upwards in the section, the carbonate strata are characterized by horizontal reflectors, which are interrupted by a regional unconformity. Onlap/downlap packages over the unconformity record a period of sea level change

    Seismic imaging and attribute analysis of Chicxulub Crater central sector, YucatĂĄn Platform, Gulf of Mexico

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    Chicxulub Crater, formed ~66Ma ago by an asteroid impact on the southern Gulf of Mexico, is the best preserved of the three large multi-ring basins in the terrestrial record. The crater structure is characterized by a semi-circular concentric ring pattern, marking the crater basin, peak ring, terrace zone and basement uplift. Analysis of a grid of 19 seismic reflection profiles using seismic attributes, marker horizons, contour surfaces and 3-D views is used to investigate the stratigraphy of the central zone. We used interactive software and routine applications to map the impact breccias, breccia-carbonate contact and post-impact carbonates. Four horizons marked by high-amplitude reflectors representing high-impedance contrasts were identified and laterally correlated in the seismic  images. Complex trace attribute analysis was applied for petrophysical characterization. Surface contour maps of base and top of stratigraphic packages were constructed, which mapped the impactites and post- and pre-impact carbonate stratigraphy. Basin floor, marked by the contact between the impact breccias and overlying carbonates is shown by laterally discontinuous high-amplitude reflectors. Discontinuous scattered reflectors interpreted as the upper breccias beneath the crater floor, have an average thickness of ~300msm. The Paleogene sedimentary units are characterized by multiple reflectors with lateral continuity, which contrast with the seismic response of underlying breccias. The basal Paleocene sediments follow the basin floor relief. Upwards in the section, the carbonate strata are characterized by horizontal reflectors, which are interrupted by a regional unconformity. Onlap/downlap packages over the unconformity record a period of sea level change

    Flavored Non-Minimal Left-Right Symmetric Model Fermion Masses and Mixings

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    A complete study on the fermion masses and flavor mixing is presented in a non-minimal left-right symmetric model (NMLRMS) where the S3⊗Z2⊗Z2e{\bf S}_{3}\otimes {\bf Z}_{2}\otimes {\bf Z}^{e}_{2} flavor symmetry drives the Yukawa couplings. In the quark sector, the mass matrices possess a kind of the generalized Fritzsch textures that allow us to fit the CKM mixing matrix in good agreement to the last experimental data. In the lepton sector, on the other hand, a soft breaking of the μ↔τ\mu\leftrightarrow \tau symmetry provides a non zero and non maximal reactor and atmospheric angles, respectively. The inverted and degenerate hierarchy are favored in the model where a set of free parameters is found to be consistent with the current neutrino data.Comment: 23 pages, 9 figures. references added, typos corrected, JCGI added his current institution;conclusions rewrote and unchanged results. Version published in European Physical Journal

    Columbus Operations - Joint Undertaking Between DLR and Industry

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