1,631 research outputs found

    Two-Rowed Hecke Algebra Representations at Roots of Unity

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    In this paper, we initiate a study into the explicit construction of irreducible representations of the Hecke algebra Hn(q)H_n(q) of type An−1A_{n-1} in the non-generic case where qq is a root of unity. The approach is via the Specht modules of Hn(q)H_n(q) which are irreducible in the generic case, and possess a natural basis indexed by Young tableaux. The general framework in which the irreducible non-generic Hn(q)H_n(q)-modules are to be constructed is set up and, in particular, the full set of modules corresponding to two-part partitions is described. Plentiful examples are given.Comment: LaTeX, 9 pages. Submitted for the Proceedings of the 4th International Colloquium ``Quantum Groups and Integrable Systems,'' Prague, 22-24 June 199

    \u27Race, Racism, and American Law \u27: A Seminar From The Indigenous, Black, And Immigrant Legal Perspectives

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    The events of fall 2016 exploded the myth of a post-racial America that some believed had been ushered in by Barack Obama’s presidency.1With the U.S. presidential campaign in full swing, soon-to-be President Donald Trump disparaged Muslims as terrorists, Mexicans as rapists and murderers, and African Americans as poor.2 Trump’s racist demagoguery came amidst the momentum of the Black Lives Matter,Standing Rock, and Dreamer movements—mass mobilizations that sought to end the police killings of Black people, protect Native American treaty rights, and grant immigrant minors legal status.3 Once again, the racial divide that has defined this nation since its inception 2019] RACE,RACISM,ANDAMERICANLAW 3reemerged in the national discourse with an intensity that exposed the fallacy of post-racialism.4The national anger, confusion, and vulnerability sown by that fall’s campaign reflected and reverberated in our community in Montana. They fractured our law school, our university, our state, and our city along lines of difference, not the least of which was racial.5 We would not know until November that Trump would be elected president. We would not know until after his inauguration that he would harden and intensify his racist agenda.6 But we sensed a new era had dawned, and therefore, we and our students needed to understand the undercurrents and urgencies of the moment. In response, we sought to reaffirm an anti-racist agenda and harness the ferment by finding common ground in the legal treatments of Native Americans, African Americans, and immigrants. That is how our seminar, “Race, Racism, and American Law from the Native American, African American, and Immigrant Legal Perspectives,” came to be

    Antiracism, Reflection, and Professional Identity

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    Intent on more systematically developing the emerging professional identities of law students, the professional identity formation movement is recasting how we think about legal education. Notably, however, the movement overlooks the structural racism imbedded in American law and legal education. While current models of professional development value diversity and cross-cultural competence, they do not adequately prepare the next generation of legal professionals to engage in the sustained work of interrupting and overthrowing race and racism in the legal profession and system. This article argues that antiracism is essential to the profession’s responsibility to serve justice and therefore key to legal professional identity. Fortunately, developing a legal antiracist identity does not require inventing a new approach. Rather, infusing reflective practice with critical race consciousness provides a sound basis from which to launch a new effort to develop the next generation of antiracist lawyers

    Antiracism, Reflection, and Professional Identity

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    Intent on more systematically developing the emerging professional identities of law students, the professional identity formation movement is recasting how we think about legal education. Notably, however, the movement overlooks the structural racism imbedded in American law and legal education. While current models of professional development value diversity and cross-cultural competence, they do not adequately prepare the next generation of legal professionals to engage in the sustained work of interrupting and overthrowing race and racism in the legal profession and system. This article argues that antiracism is essential to the profession’s responsibility to serve justice and therefore key to legal professional identity. Fortunately, developing a legal antiracist identity does not require inventing a new approach. Rather, infusing reflective practice with critical race consciousness provides a sound basis from which to launch a new effort to develop the next generation of antiracist lawyers

    Parafermionic algebras, their modules and cohomologies

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    We explore the Fock spaces of the parafermionic algebra introduced by H.S. Green. Each parafermionic Fock space allows for a free minimal resolution by graded modules of the graded 2-step nilpotent subalgebra of the parafermionic creation operators. Such a free resolution is constructed with the help of a classical Kostant's theorem computing Lie algebra cohomologies of the nilpotent subalgebra with values in the parafermionic Fock space. The Euler-Poincar\'e characteristics of the parafermionic Fock space free resolution yields some interesting identities between Schur polynomials. Finally we briefly comment on parabosonic and general parastatistics Fock spaces.Comment: 10 pages, talk presented at the International Workshop "Lie theory and its applications in Physics" (17-23 June 2013, Varna, Bulgaria

    The \u27Second Wave\u27 of Spanish Clinical Legal Education: Empirical, Pedagogical, and Institutional Lessons for a Pilot Course and Program at the University of Granada

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    Spanish clinicians today benefit from the ‘first wave’ of early adopters. We also benefit from decades of clinical scholarship—most recently about the Western European and global clinical legal education movements—and empirical data on what lawyers actually do and need in practice. In this article, the authors summarize key empirical, pedagogical, and institutional lessons to ground the creation of a pilot course and program at the University of Granada

    Sustaining productivity of a Vertisol at Warra, Queensland, with fertilisers, no-tillage, or legumes. 5. Wheat yields, nitrogen benefits and water-use efficiency of chickpea-wheat rotation

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    In this study, the benefits of chickpea–wheat rotation compared with continuous wheat cropping (wheat–wheat rotation) were evaluated for their effects on soil nitrate nitrogen, wheat grain yields and grain protein concentrations, and water-use efficiency at Warra, southern Queensland from 1988 to 1996. Benefits in terms of wheat grain yields varied, from 17% in 1993 to 61% in 1990, with a mean increase in grain yield of 40% (825 kg/ha). Wheat grain protein concentration increased from 9.4% in a wheat–wheat rotation to 10.7% in a chickpea–wheat rotation, almost a 14% increase in grain protein. There was a mean increase in soil nitrate nitrogen of 35 kg N/ha.1.2 m after 6 months of fallow following chickpea (85 kg N/ha) compared with continuous wheat cropping (50 kg N/ha). This was reflected in additional nitrogen in the wheat grain (20 kg N/ha) and above-ground plant biomass (25 kg N/ha) following chickpea. Water-use efficiency by wheat increased from a mean value of 9.2 kg grain/ha. mm in a wheat–wheat rotation to 11.7 kg grain/ha.mm in a chickpea–wheat rotation. The water-use efficiency values were closely correlated with presowing nitrate nitrogen, and showed no marked distinction between the 2 cropping sequences. Although presowing available water in soil in May was similar in both the chickpea–wheat rotation and the wheat–wheat rotation in all years except 1996, wheat in the former used about 20 mm additional water and enhanced water-use efficiency. Thus, by improving soil fertility through restorative practices such as incorporating chickpea in rotation, water-use efficiency can be enhanced and consequently water runoff losses reduced. Furthermore, beneficial effects of chickpea in rotation with cereals could be enhanced by early to mid sowing (May–mid June) of chickpea, accompanied by zero tillage practice. Wheat of ‘Prime Hard’ grade protein (≄13%) could be obtained in chickpea–wheat rotation by supplementary application of fertiliser N to wheat. In this study, incidence of crown rot of wheat caused by Fusarium graminearum was negligible, and incidence and severity of common root rot of wheat caused by Bipolaris sorokiniana were essentially similar in both cropping sequences and inversely related to the available water in soil at sowing. No other soil-borne disease was observed. Therefore, beneficial effects of chickpea on wheat yields and grain protein were primarily due to additional nitrate nitrogen following the legume crop and consequently better water-use efficiency

    Measuring Black Hole Spin using X-ray Reflection Spectroscopy

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    I review the current status of X-ray reflection (a.k.a. broad iron line) based black hole spin measurements. This is a powerful technique that allows us to measure robust black hole spins across the mass range, from the stellar-mass black holes in X-ray binaries to the supermassive black holes in active galactic nuclei. After describing the basic assumptions of this approach, I lay out the detailed methodology focusing on "best practices" that have been found necessary to obtain robust results. Reflecting my own biases, this review is slanted towards a discussion of supermassive black hole (SMBH) spin in active galactic nuclei (AGN). Pulling together all of the available XMM-Newton and Suzaku results from the literature that satisfy objective quality control criteria, it is clear that a large fraction of SMBHs are rapidly-spinning, although there are tentative hints of a more slowly spinning population at high (M>5*10^7Msun) and low (M<2*10^6Msun) mass. I also engage in a brief review of the spins of stellar-mass black holes in X-ray binaries. In general, reflection-based and continuum-fitting based spin measures are in agreement, although there remain two objects (GROJ1655-40 and 4U1543-475) for which that is not true. I end this review by discussing the exciting frontier of relativistic reverberation, particularly the discovery of broad iron line reverberation in XMM-Newton data for the Seyfert galaxies NGC4151, NGC7314 and MCG-5-23-16. As well as confirming the basic paradigm of relativistic disk reflection, this detection of reverberation demonstrates that future large-area X-ray observatories such as LOFT will make tremendous progress in studies of strong gravity using relativistic reverberation in AGN.Comment: 19 pages. To appear in proceedings of the ISSI-Bern workshop on "The Physics of Accretion onto Black Holes" (8-12 Oct 2012). Revised version adds a missing source to Table 1 and Fig.6 (IRAS13224-3809) and corrects the referencing of the discovery of soft lags in 1H0707-495 (which were in fact first reported in Fabian et al. 2009

    Controlling the structures of organic semiconductor–quantum dot nanocomposites through ligand shell chemistry

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    Nanocrystal quantum dots (QD) functionalised with active organic ligands hold significant promise as solar energy conversion materials, capable of multiexcitonic processes that could improve the efficiencies of single-junction photovoltaic devices. Small-angle X-ray and neutron scattering (SAXS and SANS) were used to characterize the structure of lead sulphide QDs post ligand-exchange with model acene-carboxylic acid ligands (benzoic acid, hydrocinnamic acid and naphthoic acid). Results demonstrate that hydrocinnamic acid and naphthoic acid ligated QDs form monolayer ligand shells, whilst benzoic acid ligated QDs possess ligand shells thicker than a monolayer. Further, the formation of a range of nanocomposite materials through the self-assembly of such acene-ligated QDs with an organic small-molecule semiconductor [5,12-bis((triisopropylsilyl)ethynyl)tetracene (TIPS-Tc)] is investigated. These materials are representative of a wider set of functional solar energy materials; here the focus is on structural studies, and their optoelectronic function is not investigated. As TIPS-Tc concentrations are increased, approaching the solubility limit, SANS data show that QD fractal-like features form, with structures possibly consistent with a diffusion limited aggregation mechanism. These, it is likely, act as heterogeneous nucleation agents for TIPS-Tc crystallization, generating agglomerates containing both QDs and TIPS-Tc. Within the TIPS-Tc crystals there seem to be three distinct QD morphologies: (i) at the crystallite centre (fractal-like QD aggregates acting as nucleating agents), (ii) trapped within the growing crystallite (giving rise to QD features ordered as sticky hard spheres), and (iii) a population of aggregate QDs at the periphery of the crystalline interface that were expelled from the growing TIPS-Tc crystal. Exposure of the QD:TIPS-Tc crystals to DMF vapour, a solvent known to be able to strip ligands from QDs, alters the spacing between PbS–hydrocinnamic acid and PbS–naphthoic acid ligated QD aggregate features. In contrast, for PbS–benzoic acid ligated QDs, DMF vapour exposure promotes the formation of ordered QD colloidal crystal type phases. This work thus demonstrates how different QD ligand chemistries control the interactions between QDs and an organic small molecule, leading to widely differing self-assembly processes. It highlights the unique capabilities of multiscale X-ray and neutron scattering in characterising such composite materials

    American Society of Hematology 2020 guidelines for sickle cell disease: Prevention, diagnosis, and treatment of cerebrovascular disease in children and adults

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    BACKGROUND: Central nervous system (CNS) complications are among the most common, devastating sequelae of sickle cell disease (SCD) occurring throughout the lifespan.OBJECTIVE: These evidence-based guidelines of the American Society of Hematology are intended to support the SCD community in decisions about prevention, diagnosis, and treatment of the most common neurological morbidities in SCD.METHODS: The Mayo Evidence-Based Practice Research Program supported the guideline development process, including updating or performing systematic evidence reviews. The panel used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, including GRADE evidence-to-decision frameworks, to assess evidence and make recommendations.RESULTS: The panel placed a higher value on maintaining cognitive function than on being alive with significantly less than baseline cognitive function. The panel developed 19 recommendations with evidence-based strategies to prevent, diagnose, and treat CNS complications of SCD in low-middle- and high-income settings.CONCLUSIONS: Three of 19 recommendations immediately impact clinical care. These recommendations include: use of transcranial Doppler ultrasound screening and hydroxyurea for primary stroke prevention in children with hemoglobin SS (HbSS) and hemoglobin SÎČ0 (HbSÎČ0) thalassemia living in low-middle-income settings; surveillance for developmental delay, cognitive impairments, and neurodevelopmental disorders in children; and use of magnetic resonance imaging of the brain without sedation to detect silent cerebral infarcts at least once in early-school-age children and once in adults with HbSS or HbSÎČ0 thalassemia. Individuals with SCD, their family members, and clinicians should become aware of and implement these recommendations to reduce the burden of CNS complications in children and adults with SCD.</p
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