1,862 research outputs found

    Problematizing Māori achievement in education policy : an exploratory mixed-methods study on teacher enactment of Ka Hikitia : a thesis presented in partial fulfilment of the requirement for the degree of Doctor of Education at Massey University, Manawatū, New Zealand

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    This thesis analyses and describes a range of factors that impact upon mainstream primary school teachersā€™ enactments of the MaĢ„ori education policy strategy, Ka Hikitia (Ministry of Education, 2013, 2018, 2020). Where this study differs is that it goes beyond the traditional implementation approach to policy research and seeks to identify and investigate the ā€˜messierā€™ aspects of interpretation, subjectivity and context, factors that are often missing in accounts of how policy works in schools. It has utilised an exploratory, two-phase mixed-methods approach to collect the data. The initial phase was a series of one-to-one interviews with a small cohort of primary school teachers from the ManawatuĢ„ region of New Zealand. The data collated helped to develop a set of initial themes that were used to formulate the second phase survey that was sent out to a wider cohort. The themes from both two phases of the study have been used in a complementary manner to engage with research and literature from the fields of MaĢ„ori education, culturally responsive pedagogy and critical policy enactment. This study concludes that teachers rely heavily upon school context and personal subjectivities to interpret and enact Ka Hikitia. It contends that teachers respond to Ka Hikitia in three key ways: considered enactment, perfunctory enactment, and/or enactment resistance. While teacher enactment is a focus of this study, it is purported that a broader consideration of how government and institutional factors impact upon teacher enactment of Ka Hikitia needs to be taken into account. Solely focusing on teachers as mere ciphers of policy reinforces institutional invisibility. This study calls for a broader understanding of how MaĢ„ori student achievement is understood and problematized in Ka Hikitia. While supporting the necessity for MaĢ„ori language, culture and identity to be an integral part of mainstream primary schools, this research urges policy makers and MaĢ„ori academics to re-consider and re-calibrate the impact of socio-economic factors upon MaĢ„ori student achievement and, henceforth, rework policy designed to address this

    Raman and fluorescence contributions to resonant inelastic soft x-ray scattering on LaAlO3_3/SrTiO3_3 heterostructures

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    We present a detailed study of the Ti 3dd carriers at the interface of LaAlO3_3/SrTiO3_3 heterostructures by high-resolution resonant inelastic soft x-ray scattering (RIXS), with special focus on the roles of overlayer thickness and oxygen vacancies. Our measurements show the existence of interfacial Ti 3dd electrons already below the critical thickness for conductivity and an increase of the total interface charge up to a LaAlO3_3 overlayer thickness of 6 unit cells before it levels out. By comparing stoichiometric and oxygen deficient samples we observe strong Ti 3dd charge carrier doping by oxygen vacancies. The RIXS data combined with photoelectron spectroscopy and transport measurements indicate the simultaneous presence of localized and itinerant charge carriers. However, it is demonstrated that the relative amount of localized and itinerant Ti 3d3d electrons in the ground state cannot be deduced from the relative intensities of the Raman and fluorescence peaks in excitation energy dependent RIXS measurements, in contrast to previous interpretations. Rather, we attribute the observation of either the Raman or the fluorescence signal to the spatial extension of the intermediate state reached in the RIXS excitation process.Comment: 9 pages, 6 figure

    Aneuploidy Drives Genomic Instability in Yeast

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    Aneuploidy decreases cellular fitness, yet it is also associated with cancer, a disease of enhanced proliferative capacity. To investigate one mechanism by which aneuploidy could contribute to tumorigenesis, we examined the effects of aneuploidy on genomic stability. We analyzed 13 budding yeast strains that carry extra copies of single chromosomes and found that all aneuploid strains exhibited one or more forms of genomic instability. Most strains displayed increased chromosome loss and mitotic recombination, as well as defective DNA damage repair. Aneuploid fission yeast strains also exhibited defects in mitotic recombination. Aneuploidy-induced genomic instability could facilitate the development of genetic alterations that drive malignant growth in cancer

    Performance and carcass traits of crossbred cattle raised in pastures supplemented or not with virginiamycin.

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    he aim of this study was to assess performance and carcass traits of crossbred cattle raised grazing tropical grasses, receiving supplement with or without virginiamycin (VM). Steers (n = 49) and heifers (n = 56) produced from matting Nellore, Ā½ Nellore x Ā½ Angus and Ā½ Nellore x Ā½ Caracu dams with Braford, Charbray and Caracu sires were raised grazing tropical grasses ( Brachiaria brizantha cv. Marandu) from 9 to 20 mo of age. The animals were divided into eight paddocks of eight hectares each, with care to form groups containing individuals of all genetic groups and balanced in age and average body weight (BW). During the dry season (July to October) cattle received protein supplements containing (n = 52) or not VM (n = 53), formulated for intake of 1 g kg -1 of BW and during the rainy season (November to June) cattle received mineral mixtures containing (n = 52) or not VM (n = 53). The VM was included in the supplements to provide an intake of 45 mg 100 kg -1 of BW. Supplements were provided in open troughs ad libitum and intake was evaluated by weighing monthly leftovers

    Automatic spacecraft docking using computer vision-based guidance and control techniques

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76754/1/AIAA-21001-304.pd

    Isoform-specific potentiation of stem and progenitor cell engraftment by AML1/RUNX1

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    Background: AML1/RUNX1 is the most frequently mutated gene in leukaemia and is central to the normal biology of hematopoietic stem and progenitor cells. However, the role of different AML1 isoforms within these primitive compartments is unclear. Here we investigate whether altering relative expression of AML1 isoforms impacts the balance between cell self-renewal and differentiation in vitro and in vivo. Methods and Findings: The human AML1a isoform encodes a truncated molecule with DNA-binding but no transactivation capacity. We used a retrovirus-based approach to transduce AML1a into primitive haematopoietic cells isolated from the mouse. We observed that enforced AML1a expression increased the competitive engraftment potential of murine long-term reconstituting stem cells with the proportion of AML1a-expressing cells increasing over time in both primary and secondary recipients. Furthermore, AML1a expression dramatically increased primitive and committed progenitor activity in engrafted animals as assessed by long-term culture, cobblestone formation, and colony assays. In contrast, expression of the full-length isoform AML1b abrogated engraftment potential. In vitro, AML1b promoted differentiation while AML1a promoted proliferation of progenitors capable of short-term lymphomyeloid engraftment. Consistent with these findings, the relative abundance of AML1a was highest in the primitive stem/progenitor compartment of human cord blood, and forced expression of AML1a in these cells enhanced maintenance of primitive potential both in vitro and in vivo. Conclusions: These data demonstrate that the "a" isoform of AML1 has the capacity to potentiate stem and progenitor cell engraftment, both of which are required for successful clinical transplantation. This activity is consistent with its expression pattern in both normal and leukaemic cells. Manipulating the balance of AML1 isoform expression may offer novel therapeutic strategies, exploitable in the contexts of leukaemia and also in cord blood transplantation in adults, in whom stem and progenitor cell numbers are often limiting. Ā© 2007 Tsuzuki et al

    Crossbreeding applied to systems of beef cattle production to improve performance traits and carcass quality.

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    Crossbreeding represents an important technique to improve growth, beef quality and adaptability in beef production systems in tropical countries. The aim of this study was to evaluate sire and dam breed effects on performance and carcass traits of crossbred cattle produced in a tropical environment. Heifers and steers were evaluated during the pre-weaning, the post-weaning (n = 173) and the finishing phase (n = 123). Animals were produced by mating Nellore (N_N), Angus Ɨ Nellore (A_N) and Caracu Ɨ Nellore (C_N) dams with Braford, Charbray and Caracu sires. After weaning, animals were raised grazing on Marandu grass for 12 months; thereafter they were housed in individual pens and finished in a feedlot, receiving a total mixed ration. Ultrasound carcass evaluations were performed to determine ribeye area (R_A), backfat thickness (B_T) and rump fat thickness (R_T). A_N progeny were heavier at birth than N_N (P 0.05). Progeny of N_N cows had greater B_T (P 0.05). A_N progeny were superior in final B_T compared to C_N (P < 0.01), and Braford progeny had greater R_T at the end of finishing than Charbray (P = 0.05). The use of crossbred dams allows an increase in productivity until weaning, but this is not maintained in the post-weaning and finishing periods. The use of Braford sires produces similar growth performance in the different stages of the production system to those seen with Charbray and Caracu sires but generates animals with higher fat thickness at the end of finishing, which may improve carcass quality and commercial value

    Vaughan-Jackson-like syndrome as an unusual presentation of Kienbƶck's disease: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Kienbƶck's disease is a condition of osteonecrosis of the lunate bone in the hand, and most patients present with a painful and sometimes swollen wrist with a limited range of motion in the affected wrist. Vaughan-Jackson syndrome is characterized by the disruption of the digital extensor tendons, beginning on the ulnar side with the extensor digiti minimi and extensor digitorum communis tendon of the small finger. It is most commonly associated with rheumatoid arthritis. We describe a case of a patient with an unusual presentation of Kienbƶck's disease with symptoms similar to those of Vaughan-Jackson syndrome.</p> <p>Case presentation</p> <p>A 40-year-old man of Indian ethnic origin with no known history of trauma presented to our clinic with a ten-day history of an inability to extend his right little and ring fingers with associated pain in his right wrist. He was being treated with long-term steroids but had no other significant medical history. His examination revealed an inability to extend the metacarpal and phalangeal joints of the right ring and little fingers with localized tenderness over the lunate bone. Spontaneous disruption of the extensor tendons was diagnosed clinically and, after radiological investigation, was confirmed to be secondary to dorsal extrusion of the fragmented lunate bone. The patient underwent surgical repair of the tendons and had a full recovery afterward.</p> <p>Conclusion</p> <p>Kienbƶck's disease, though rare, is an important cause of spontaneous extensor tendon rupture. The original description of Vaughan-Jackson syndrome was of rupture of the extensor tendons of the little and ring fingers caused by attrition at an arthritic inferior radioulnar joint. We describe a case of a patient with Kienbƶck's disease that first appeared to be a Vaughan-Jackson-like syndrome.</p

    Remodelling of human atrial K+ currents but not ion channel expression by chronic Ī²-blockade

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    Chronic Ī²-adrenoceptor antagonist (Ī²-blocker) treatment in patients is associated with a potentially anti-arrhythmic prolongation of the atrial action potential duration (APD), which may involve remodelling of repolarising K+ currents. The aim of this study was to investigate the effects of chronic Ī²-blockade on transient outward, sustained and inward rectifier K+ currents (ITO, IKSUS and IK1) in human atrial myocytes and on the expression of underlying ion channel subunits. Ion currents were recorded from human right atrial isolated myocytes using the whole-cell-patch clamp technique. Tissue mRNA and protein levels were measured using real time RT-PCR and Western blotting. Chronic Ī²-blockade was associated with a 41% reduction in ITO density: 9.3ā€‰Ā±ā€‰0.8 (30 myocytes, 15 patients) vs 15.7ā€‰Ā±ā€‰1.1 pA/pF (32, 14), pā€‰&#60;ā€‰0.05; without affecting its voltage-, time- or rate dependence. IK1 was reduced by 34% at āˆ’120 mV (pā€‰&#60;ā€‰0.05). Neither IKSUS, nor its increase by acute Ī²-stimulation with isoprenaline, was affected by chronic Ī²-blockade. Mathematical modelling suggested that the combination of ITO- and IK1-decrease could result in a 28% increase in APD90. Chronic Ī²-blockade did not alter mRNA or protein expression of the ITO pore-forming subunit, Kv4.3, or mRNA expression of the accessory subunits KChIP2, KChAP, KvĪ²1, KvĪ²2 or frequenin. There was no reduction in mRNA expression of Kir2.1 or TWIK to account for the reduction in IK1. A reduction in atrial ITO and IK1 associated with chronic Ī²-blocker treatment in patients may contribute to the associated action potential prolongation, and this cannot be explained by a reduction in expression of associated ion channel subunits
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