912 research outputs found

    What Happens to the Tax Return after It Is Filed?, cont.

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    Ultrasonic borehole flowmeter

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    Published ArticleAlthough research has been conducted in the field of Acoustic Doppler Borehole Flowmeters (ADBF), it has been focused on point source of flow and three dimensional borehole flow techniques. However as of yet, no studies have been conducted on the possible use of Acoustic Doppler Borehole Profiling (ADBP). This technique of borehole flow measurement is possibly a revolutionary concept in how vertical flow in a borehole is measured. It makes use of a single inexpensive transducer that can float on the surface of the water in a borehole and use Acoustic Doppler techniques to profile the flow in a borehole. No complicated and expensive flow probe winching systems will be required. Another added benefit of the ADBP will be the non-evasive technologies that comprise its design. Current borehole flow probes are required to be present at the point of flow measurement in the borehole. The presence of the probe inadvertently alters the flow in the borehole by adding resistance to the flow in the borehole. Under stressed or pumped flow tests these flow resistance effects cause sufficient pressure gradients at the flow sensors to divert part of the flow away from the sensor. This causes erroneous readings of flow as a part of the flow in the borehole is not accounted for. In ADBP the sensor is not physically present at the point of flow being read. This makes the ADBP technique of borehole flow measurement far more representative of the natural flow conditions in the borehole under ambient and stressed conditions

    The Physics Case for the New Muon (g-2) Experiment

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    This White Paper briefly reviews the present status of the muon (g-2) experiment and the physics motivation for a new effort. The present comparison between experiment and theory indicates a tantalizing 3.4σ3.4 \sigma deviation. An improvement in precision on this comparison by a factor of 2--with the central value remaining unchanged--will exceed the ``discovery'' threshold, with a sensitivity above 6σ6 \sigma. The 2.5-fold reduction improvement goal of the new Brookhaven E969 experiment, along with continued steady reduction of the standard model theory uncertainty, will achieve this more definitive test. Already, the (g-2) result is arguably the most compelling indicator of physics beyond the standard model and, at the very least, it represents a major constraint for speculative new theories such as supersymmetry or extra dimensions. In this report, we summarize the present experimental status and provide an up-to-date accounting of the standard model theory, including the expectations for improvement in the hadronic contributions, which dominate the overall uncertainty. Our primary focus is on the physics case that motivates improved experimental and theoretical efforts. Accordingly, we give examples of specific new-physics implications in the context of direct searches at the LHC as well as general arguments about the role of an improved (g-2) measurement. A brief summary of the plans for an upgraded effort complete the report.Comment: 18 pages, 7 figure

    The adenoma-carcinoma sequence in the colorectum--early appearance of a hierarchy of small intestinal mucin antigen (SIMA) epitopes and correlation with malignant potential.

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    The colorectal adenoma-carcinoma sequence was examined in relation to the ectopic expression of the oncofoetal Small Intestinal Mucin Antigen (SIMA), to the development of morphologic changes in the adenoma and perineoplastic mucosa and to indices of malignant potential. Four anti-SIMA MAbs, which define a novel hierarchy of SIMA epitopes in the normal small intestine and adjacent to colorectal cancers, were used in a retrospective immunohistochemical study of Familial Adenomatous Polyposis (FAP, n = 183) and non-familial (n = 44) adenomas. Inappropriate expression of SIMA epitopes was first detected in mucosa adjacent to minute microadenomas larger than three glands, and with increase in size, in increasing amounts within adenomas themselves, but not with microadenomas smaller than three glands or regions of flat mucosa free of adenomas. SIMA epitope expressed in mucosa adjacent to adenomas preceded changes in perineoplastic morphology, which progressed with adenoma growth to resemble transitional mucosa (TM) adjacent to cancers. Thus, the onset of both SIMA expression and morphological changes in TM were consistent with reactive rather than pre-existing field change phenomena. The previously reported hierarchy of four SIMA epitopes (5C5, 3D4, 4D3, 6C5) was also consistently observed in the adenoma-carcinoma sequence, and applied to (i) the order of epitope detection, (ii) the number of positive adenomas and (iii) extent of staining; (iv) the height in the crypt and (v) distance from the adenoma to which epitopes were expressed in perineoplastic mucosa. These observations are consistent with a progression of changes in mucin composition with adenoma development. The percentage of positive adenomas and reactivity scores for each anti-SIMA MAb correlated with increasing adenoma size, degree of dysplasia and growth pattern. SIMA expression appears to predate the earliest reported oncogene and tumour suppressor gene changes, was persistent and increased throughout adenoma development. SIMA epitopes are thus markers of very early neoplastic change, whose expression correlates with malignant potential and may contribute to the accumulation of changes necessary for tumourigenesis

    Analysis of a jet stream induced gravity wave associated with an observed ice cloud over Greenland

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    International audienceA polar stratospheric ice cloud (PSC type II) was observed by airborne lidar above Greenland on 14 January 2000. Is was the unique observation of an ice cloud over Greenland during the SOLVE/THESEO 2000 campaign. Mesoscale simulations with the hydrostatic HRM model are presented which, in contrast to global analyses, are capable to produce a vertically propagating gravity wave that induces the low temperatures at the level of the PSC afforded for the ice formation. The simulated minimum temperature is ~8 K below the driving analyses and ~3 K below the frost point, exactly coinciding with the location of the observed ice cloud. Despite the high elevations of the Greenland orography the simulated gravity wave is not a mountain wave. Analyses of the horizontal wind divergence, of the background wind profiles, of backward gravity wave ray-tracing trajectories, of HRM experiments with reduced Greenland topography and of several instability diagnostics near the tropopause level provide consistent evidence that the wave is emitted by the geostrophic adjustment of a jet instability associated with an intense, rapidly evolving, anticyclonically curved jet stream. In order to evaluate the potential frequency of such non-orographic polar stratospheric cloud events, an approximate jet instability diagnostic is performed for the winter 1999/2000. It indicates that ice-PSCs are only occasionally generated by gravity waves emanating from an unstable jet

    Manifesting Unobtainable Secrets: Threshold Elliptic Curve Key Generation using Nested Shamir Secret Sharing

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    We present a mechanism to manifest unobtainable secrets using a nested Shamir secret sharing scheme to create public/private key pairs for elliptic curves. A threshold secret sharing scheme can be used as a decentralised trust mechanism with applications in identity validation, message decryption, and agreement empowerment. Decentralising trust means that there is no single point vulnerability which could enable compromise of a system. Our primary interest is in twisted Edwards curves as used in EdDSA, and the related Diffie-Hellman key-exchange algorithms. The key generation is also decentralised, so can be used as a decentralised secret RNG suitable for use in other algorithms. The algorithms presented could be used to fill a ``[TBS]'' in the draft IETF specification ``Threshold modes in elliptic curves'' published in 2020 and updated in 2022

    MyD88 adapter-like (Mal)/TIRAP interaction with TRAF6 is critical for TLR2- and TLR4-mediated NF-kappaB proinflammatory responses

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    Toll/interleukin-1 (TIR)receptor-containing adapters are critical in orchestrating the different signal transduction pathways following Toll-like receptor (TLR) activation. MyD88 adapter-like (Mal), also termed TIRAP, is involved in bridging MyD88 to the receptor complex for TLR-2 and TLR4 signaling in response to bacterial infection. We have previously reported an interaction between Mal and tumor necrosis factor receptor-associated factor 6 (TRAF6) via a TRAF6-binding motif, the disruption of which inhibited TLR-mediated NF-kappaB-luciferase reporter activity. Given the recent report of intracellular TRAM localization promoting sequential signaling in TLR4 responses, we further characterized Mal interaction with TRAF6, the cellular localization, and the outcomes of disrupting this association on TLR inflammatory responses. We found that Mal and TRAF6 directly interact in response to TLR2 and TLR4 stimulation, although membrane localization is not necessary to facilitate interaction. Critically, reconstitution of murine Mal-deficient macrophages with MalE190A, containing a mutation within the TRAF6-binding motif, fails to reconstitute the proinflammatory response to TLR2 and TLR4 ligands compared with wild type Mal. Furthermore, Mal interaction with TRAF6 mediates Ser phosphorylation of the p65 subunit of NF-kappaB and thus controls transcriptional activation but not nuclear translocation of NF-kappaB. This study characterizes the novel role for Mal in facilitating the direct recruitment of TRAF6 to the plasma membrane, which is necessary for TLR2- and TLR4-induced transactivation of NF-kappaB and regulation of the subsequent pro-inflammatory response

    Aberrant expression of intestinal mucin antigens associated with colorectal carcinoma defined by a panel of monoclonal antibodies.

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    Small intestine mucin antigen (SIMA) is an oncofoetal antigen for the colon and is distinct from the normal large intestinal mucin antigen (LIMA). In the present study, a panel of anti-SIMA and anti-LIMA monoclonal antibodies (MAb) was used to charaterise altered mucin expression in colorectal adenocarcinomas, by immunohistochemistry and quantitative immunoassays of tissue extracts. These results are compared with CEA expression and correlated with various clinicopathological indices. All mucin MAb reacted with a high proportion of the 100 colon cancers of every stage, histological type (including non-mucinous cancers), differentiation, site, or size. Inappropriate SIMA production was detected by either anti-SIMA MAb 4D3 or 4A1, even in 85% of early stage cancers. MAb 4D3 reacted with a higher proportion of cancers of smaller size and better differentiation. At the subcellular level, both anti-SIMA MAb showed reactivity typical of normal mucin, i.e., goblet cell and extracellular mucin. The normal colonic antigen, LIMA, was also detectable in the majority of cases, but quantitatively overproduced in some cases and reduced in others. However, in contrast to SIMA, LIMA was detected in predominantly undifferentiated cancer cells but not in goblet cells. Heterogeneity of MAb reactivity between cases and complementarity within each cancer was frequently observed. Mucin reactive with at least one of the MAb was detected in all of the CEA-negative cancers. A high rate of inappropriate SIMA expression was also detected in the perineoplastic transitional mucosa (88%, c.f. CEA, 35%) and adjacent, morphologically normal mucosa (80% c.f. CEA, 24%), indicating biochemical changes similar to the cancer. This panel of anti-mucin MAb demonstrated altered mucin glycoprotein metabolism associated with the development and progression of most colorectal cancers, which emphasises their utility as indicators of neoplastic change in the colon, and their superiority to CEA
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