990 research outputs found

    #Landback: Northern Cheyenne to Reclaim Sovereignty

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    Statement of Purpose: As new movements emerge and become evermore relevant across Indian Country, I believe that it is important to address and document these movements and their themes in academic scholarship. Namely, the #Landback, Indigenous Data Sovereignty, and Indigenous Data Governance movements are significant. Proof of this significance lies within their purposes and the very fact that there is a lack of conversation regarding this discourse in the scholarly world. Therefore, the purpose of this essay is to increase this discourse by exploring and discussing Indigenous activism, land reclamation, resurgence, sovereignty, and #Landback in the context of the So’taa’eo/TsetsĂȘhesĂȘstĂąhase/Tsitsistas (Northern Cheyenne) Nation. I believe that through these movements the Northern Cheyenne people and other Indigenous nations have the opportunity to resurge, (re)enforce, and reclaim their sovereignty, on levels that concern the health and well-being of these nations – including that of humans, plants, and animal relatives. Lastly, on a more personal note, this essay was created in my interest to bring light to the persistence and resistance work that my people and nation continuously and consistently practice – that ultimately enables them to reject the broken promises of the coal and mining industry

    An Analysis of Target Location Error Generated by the Litening Pod as Integrated on the AV-8B Harrier II

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    The modern battlefield continues to rapidly change requiring a quick, reactive, and precise strike capability by air forces. The Litening Pod (Tpod), as integrated on the AV-8B Harrier, can now be easily used by the pilot as a target coordinate generation source for global positioning system (GPS) guided weapons. This thesis has attempted to mathematically determine the target coordinate generation accuracy of the Tpod. The total mathematical target location error (TLE) was then compared to actual flight test data. The analytical approach to calculating the accuracy of Tpod generated target coordinates has shown to be too conservative. This is due to no consideration being given to the possibility that errors are not necessarily additive in nature but instead will most likely cancel to some extent and also that performance of the Tpod is better than specified. Because of this, the analytical approach shows the Tpod coordinate generation capability is not good enough to meet the joint direct attack munitions (JDAM) specification at reasonable standoff ranges. Actual flight test data shows the Tpod is able to meet the specification threshold for JDAM TLE inside 6 nautical miles (nm) slant range. The number one recommendation for minimizing the TLE for Tpod generated target coordinates is to fix the aircraft software to properly set the relative bit for Tpod targeting

    Functions of the novel RhoGAP proteins RGA-3 and RGA-4 in the germ line and in the early embryo of C. elegans

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    We have identified two redundant GTPase activating proteins (GAPs) ñ€“ RGA-3 and RGA-4 ñ€“ that regulate Rho GTPase function at the plasma membrane in early Caenorhabditis elegans embryos. Knockdown of both RhoGAPs resulted in extensive membrane ruffling, furrowing and pronounced pseudo-cleavages. In addition, the non-muscle myosin NMY-2 and RHO-1 accumulated on the cortex at sites of ruffling. RGA-3 and RGA-4 are GAPs for RHO-1, but most probably not for CDC-42, because only RHO-1 was epistatic to the two GAPs, and the GAPs had no obvious influence on CDC-42 function. Furthermore, knockdown of either the RHO-1 effector, LET-502, or the exchange factor for RHO-1, ECT-2, alleviated the membrane-ruffling phenotype caused by simultaneous knockdown of both RGA-3 and RGA-4 [rga-3/4 (RNAi)]. GFP::PAR-6 and GFP::PAR-2 were localized at the anterior and posterior part of the early C. elegans embryo, respectively showing that rga-3/4 (RNAi) did not interfere with polarity establishment. Most importantly, upon simultaneous knockdown of RGA-3, RGA-4 and the third RhoGAP present in the early embryo, CYK-4, NMY-2 spread over the entire cortex and GFP::PAR-2 localization at the posterior cortex was greatly diminished. These results indicate that the functions of CYK-4 are temporally and spatially distinct from RGA-3 and RGA-4 (RGA-3/4). RGA-3/4 and CYK-4 also play different roles in controlling LET-502 activation in the germ line, because rga-3/4 (RNAi), but not cyk-4 (RNAi), aggravated the let-502(sb106) phenotype. We propose that RGA-3/4 and CYK-4 control with which effector molecules RHO-1 interacts at particular sites at the cortex in the zygote and in the germ line

    The variable stellar wind of Rigel probed at high spatial and spectral resolution

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    We present a spatially resolved, high-spectral resolution (R=12000) K-band temporal monitoring of Rigel using AMBER at the VLTI. Rigel was observed in the Bracket Gamma line and its nearby continuum in 2006-2007, and 2009-2010. These unprecedented observations were complemented by contemporaneous optical high-resolution spectroscopy. We analyse the near-IR spectra and visibilities with the 1D non-LTE radiative-transfer code CMFGEN. The differential and closure phase signal exhibit asymmetries that are interpreted as perturbations of the wind. A systematic visibility decrease is observed across the Bracket Gamma. During the 2006-2007 period the Bracket Gamma and likely the continuum forming regions were larger than in the 2009-2010 epoch. Using CMFGEN, we infer a mass-loss rate change of about 20% between the two epochs. We further find time variations in the differential visibilities and phases. The 2006-2007 period is characterized by noticeable variations of the differential visibilities in Doppler position and width and by weak variations in differential and closure phase. The 2009-2010 period is much more quiet with virtually no detectable variations in the dispersed visibilities but a strong S-shape signal is observed in differential phase coinciding with a strong ejection event discernible in the optical spectra. The differential phase signal that is sometimes detected is reminiscent of the signal computed from hydrodynamical models of corotating interaction regions. For some epochs the temporal evolution of the signal suggests the rotation of the circumstellar structures.Comment: Paper accepted in the A&A journa

    Expression of cadherin and NCAM in human small cell lung cancer cell lines and xenografts.

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    Tumour cell adhesion, detachment and aggregation seem to play an important part in tumour invasion and metastasis, and numerous cell adhesion molecules are expressed by tumour cells. Several families of cell-cell adhesion molecules have been described, of which two groups are particularly well characterised, the cadherin family and the Ig superfamily member, neural cell adhesion molecule (NCAM). We investigated expression of these two adhesion molecule families in small cell lung cancer (SCLC) cell lines and xenografts by immunoblotting. Nineteen tumours established from 15 patients with SCLC were examined. All tumours but one expressed both cadherin and NCAM. The tumours expressed one, two or rarely three cadherin bands, and different combinations of two major isoforms of NCAM with M(r)'s of approximately 190,000 and 135,000. Polysialylation of NCAM, a feature characteristic of NCAM during embryonic development, which may play a role in connection with tumour invasion and metastasis, was found in 14/18 NCAM expressing SCLC tumours. Individual tumours grown as cell lines and as nude mouse xenografts showed no qualitative differences in cadherin or NCAM expression

    Large-scale environments of binary AGB stars probed by Herschel. II: Two companions interacting with the wind of pi1 Gruis

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    Context. The Mass loss of Evolved StarS (MESS) sample observed with PACS on board the Herschel Space Observatory revealed that several asymptotic giant branch (AGB) stars are surrounded by an asymmetric circumstellar envelope (CSE) whose morphology is most likely caused by the interaction with a stellar companion. The evolution of AGB stars in binary systems plays a crucial role in understanding the formation of asymmetries in planetary nebul{\ae} (PNe), but at present, only a handful of cases are known where the interaction of a companion with the stellar AGB wind is observed. Aims. We probe the environment of the very evolved AGB star π1\pi^1 Gruis on large and small scales to identify the triggers of the observed asymmetries. Methods. Observations made with Herschel/PACS at 70 ÎŒ\mum and 160 ÎŒ\mum picture the large-scale environment of π1\pi^1 Gru. The close surroundings of the star are probed by interferometric observations from the VLTI/AMBER archive. An analysis of the proper motion data of Hipparcos and Tycho-2 together with the Hipparcos Intermediate Astrometric Data help identify the possible cause for the observed asymmetry. Results. The Herschel/PACS images of π1\pi^1 Gru show an elliptical CSE whose properties agree with those derived from a CO map published in the literature. In addition, an arc east of the star is visible at a distance of 38â€Čâ€Č38^{\prime\prime} from the primary. This arc is most likely part of an Archimedean spiral caused by an already known G0V companion that is orbiting the primary at a projected distance of 460 au with a period of more than 6200 yr. However, the presence of the elliptical CSE, proper motion variations, and geometric modelling of the VLTI/AMBER observations point towards a third component in the system, with an orbital period shorter than 10 yr, orbiting much closer to the primary than the G0V star.Comment: 13 pages, 11 figures, accepted for publication in Astronomy & Astrophysic

    A least angle regression model for the prediction of canonical and non-canonical miRNA-mRNA interactions

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    microRNAs (miRNAs) are short non-coding RNAs with regulatory functions in various biological processes including cell differentiation, development and oncogenic transformation. They can bind to mRNA transcripts of protein-coding genes and repress their translation or lead to mRNA degradation. Conversely, the transcription of miRNAs is regulated by proteins including transcription factors, co-factors, and messenger molecules in signaling pathways, yielding a bidirectional regulatory network of gene and miRNA expression. We describe here a least angle regression approach for uncovering the functional interplay of gene and miRNA regulation based on paired gene and miRNA expression profiles. First, we show that gene expression profiles can indeed be reconstructed from the expression profiles of miRNAs predicted to be regulating the specific gene. Second, we propose a two-step model where in the first step, sequence information is used to constrain the possible set of regulating miRNAs and in the second step, this constraint is relaxed to find regulating miRNAs that do not rely on perfect seed binding. Finally, a bidirectional network comprised of miRNAs regulating genes and genes regulating miRNAs is built from our previous regulatory predictions. After applying the method to a human cancer cell line data set, an analysis of the underlying network reveals miRNAs known to be associated with cancer when dysregulated are predictors of genes with functions in apoptosis. Among the predicted and newly identified targets that lack a classical miRNA seed binding site of a specific oncomir, miR-19b-1, we found an over-representation of genes with functions in apoptosis, which is in accordance with the previous finding that this miRNA is the key oncogenic factor in the mir-17-92 cluster. In addition, we found genes involved in DNA recombination and repair that underline its importance in maintaining the integrity of the cell

    NDC1: a crucial membrane-integral nucleoporin of metazoan nuclear pore complexes

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    POM121 and gp210 were, until this point, the only known membrane-integral nucleoporins (Nups) of vertebrates and, thus, the only candidate anchors for nuclear pore complexes (NPCs) within the nuclear membrane. In an accompanying study (see Stavru et al. on p. 477 of this issue), we provided evidence that NPCs can exist independently of POM121 and gp210, and we predicted that vertebrate NPCs contain additional membrane-integral constituents. We identify such an additional membrane protein in the NPCs of mammals, frogs, insects, and nematodes as the orthologue to yeast Ndc1p/Cut11p. Human NDC1 (hNDC1) likely possesses six transmembrane segments, and it is located at the nuclear pore wall. Depletion of hNDC1 from human HeLa cells interferes with the assembly of phenylalanine-glycine repeat Nups into NPCs. The loss of NDC1 function in Caenorhabditis elegans also causes severe NPC defects and very high larval and embryonic mortality. However, it is not ultimately lethal. Instead, homozygous NDC1-deficient worms can be propagated. This indicates that none of the membrane-integral Nups is universally essential for NPC assembly, and suggests that NPC biogenesis is an extremely fault-tolerant process

    How to diagnose plantaris tendon involvement in midportion Achilles tendinopathy - clinical and imaging findings

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    Background: The purpose of this investigation was to evaluate if clinical assessment, Ultrasound + Colour Doppler (US + CD) and Ultrasound Tissue Characterisation (UTC) can be useful in detecting plantaris tendon involvement in patients with midportion Achilles tendinopathy. Methods: Twenty-three tendons in 18 patients (14 men, mean age: 37 years and 4 women: 44 years) (5 patients with bilateral tendons) with midportion Achilles tendinopathy were surgically treated with a scraping procedure and plantaris tendon removal. For all tendons, clinical assessment, Ultrasound + Colour Doppler (US + CD) examination and Ultrasound Tissue Characterisation (UTC) were performed. Results: At surgery, all 23 cases had a plantaris tendon located close to the medial side of the Achilles tendon. There was vascularised fat tissue in the interface between the Achilles and plantaris tendons. Clinical assessment revealed localised medial activity-related pain in 20/23 tendons and focal medial tendon tenderness in 20/23 tendons. For US + CD, 20/23 tendons had a tendon-like structure interpreted to be the plantaris tendon and localised high blood flow in close relation to the medial side of the Achilles. For UTC, 19/23 tendons had disorganised (type 3 and 4) echopixels located only in the medial part of the Achilles tendon indicating possible plantaris tendon involvement. Conclusions: US + CD directly, and clinical assessment indirectly, can detect a close by located plantaris tendon in a high proportion of patients with midportion Achilles tendinopathy. UTC could complement US + CD and clinical assessment by demonstrating disorganised focal medial Achilles tendon structure indicative of possible plantaris involvement
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