Provenance history of a Late Triassic-Jurassic Gondwana margin forearc basin, Murihiku Terrane, North Island, New Zealand: petrographic and geochemical constraints

The Murihiku Terrane in the North Island was a forearc basin adjacent to a volcanic arc along the eastern margin of Gondwana during the Mesozoic. The rocks that infill the basin are mainly volcaniclastic sandstones and mudstones, often turbiditic, with sparse shellbeds, rhyolitic tuffs, carbonaceous sandstones, plant beds, concretionary horizons, and rare thick granitoid-rich conglomerates. Petrographic studies of the rock fragments in the sandstones show that andesites are the dominant lithic type, but there is a wide range of other lithologies, including dacites, rhyolites, ignimbrites, granitoids, quartzofeldspathic mica schists, rare amphibolites, and reworked mudstones and sandstones. The sandstones are texturally and mineralogically immature and suggest deposition relatively close to a source of high relief, undergoing physical rather than chemical weathering in cool- to cold-temperate conditions. Geochemical analyses of 67 whole-rock volcaniclastic sandstones and siltstones indicate that they were derived from an active and dissected volcanic arc in a convergent margin setting built upon relatively thin continental crust. Modal petrographic data and whole-rock geochemistry both confirm that there were systematic variations with time in the composition of clastic material being supplied to the basin. From the Late Triassic to Middle Jurassic, there was a decrease in silicic volcanic material, plutonics, and metamorphics, and an increase in the supply of andesitic detritus. This was followed in the Late Jurassic by a broader range of volcanic detritus, varying from basaltic andesite to rhyolite, which may have been caused by progressive extension of the volcanic arc and thinning of the crust, a precursor to the breakup of Gondwana in the Early-Middle Cretaceous. Comparison with the Southland segment of the Murihiku Terrane in the South Island suggests that there were significant along-arc source variations, with relatively less silicic but greater andesitic and continental crust contributions in the North Island than in Southland. This may be analogous to the modern Taupo-Kermadec arc where there is a south-north along-arc transition from a continental to an oceanic arc

teacher shortage as a local phenomenon: district leader sensemaking, responses, and implications for policy

While the teacher shortage is a national crisis, the manifestations of the shortage are felt most acutely at the local district level. The diversity of these micro-contexts often leads to disparities in the ways local school systems are served by large-scale initiatives. District leaders provide an important lens for understanding the localized manifestation of teacher shortages. This research contributes to the existing macro-level literature on teacher shortages through investigation of the ways in which district leaders in West Virginia make sense of and respond to the teacher shortage. As part of a broader study, we share analyses of interviews with seven district leaders across five county school districts and highlight the ways in which leaders made sense of the phenomenon in paradoxical ways, both in terms of the most salient causes as well as the perceived locus of control in addressing the teacher shortage. Findings also highlight the way district leader sensemaking led to action, with responses differing based on relative affordances of metropolitan versus rural contexts. We conclude with implications for policy and research to further understand the local nature of teacher shortages and to address the problem, particularly in rural contexts underserved by current research and policy

Falta de professores como um fenômeno local: Sensemaking do líder distrital, respostas e implicações para políticas

While the teacher shortage is a national crisis, the manifestations of the shortage are felt most acutely at the local district level. The diversity of these micro-contexts often leads to disparities in the ways local school systems are served by large-scale initiatives. District leaders provide an important lens for understanding the localized manifestation of teacher shortages. This research contributes to the existing macro-level literature on teacher shortages through investigation of the ways in which district leaders in West Virginia make sense of and respond to the teacher shortage. As part of a broader study, we share analyses of interviews with seven district leaders across five county school districts and highlight the ways in which leaders made sense of the phenomenon in paradoxical ways, both in terms of the most salient causes as well as the perceived locus of control in addressing the teacher shortage. Findings also highlight the way district leader sensemaking led to action, with responses differing based on relative affordances of metropolitan versus rural contexts. We conclude with implications for policy and research to further understand the local nature of teacher shortages and to address the problem, particularly in rural contexts underserved by current research and policy. Si bien la escasez de docentes es una crisis nacional, las manifestaciones de escasez se sienten con mayor intensidad a nivel de distrito local. La diversidad de estos microconceptos a menudo conduce a disparidades en la forma en que los sistemas escolares locales son atendidos por iniciativas a gran escala. Los líderes del distrito proporcionan una lente importante para comprender la manifestación localizada de la escasez de maestros. Esta investigación contribuye a la literatura existente sobre la escasez de maestros al investigar las formas en que los líderes del distrito en West Virginia entienden y responden a la escasez de maestros. Como parte de un estudio más amplio, compartimos el análisis de entrevistas con siete líderes de distrito en cinco distritos escolares del condado y destacamos formas en que los líderes entendieron el fenómeno paradójicamente, en términos de las causas más destacadas, así como el lugar percibido. de control para abordar la escasez de docentes. Los hallazgos también resaltan cómo la sensemakingdel líder del distrito condujo a la acción, con respuestas diferentes en función de las posibilidades relativas de los contextos metropolitanos versus rurales. Concluimos con implicaciones de política e investigación para una mejor comprensión de la naturaleza local de la escasez de docentes y para abordar el problema, particularmente en contextos rurales no cubiertos por la investigación y la política actual.Embora a escassez de professores seja uma crise nacional, as manifestações da escassez são sentidas mais intensamente no nível do distrito local. A diversidade desses microconceitos freqüentemente leva a disparidades na forma como os sistemas escolares locais são atendidos por iniciativas de larga escala. Os líderes distritais fornecem uma lente importante para entender a manifestação localizada da falta de professores. Esta pesquisa contribui para a literatura existente sobre a escassez de professores através da investigação das maneiras pelas quais os líderes distritais em West Virginia compreendem e respondem à escassez de professores. Como parte de um estudo mais amplo, compartilhamos análises de entrevistas com sete líderes distritais em cinco distritos escolares do condado e destacamos as maneiras pelas quais os líderes entenderam o fenômeno de maneira paradoxal, em termos das causas mais salientes e do lócus percebido. de controle na abordagem da escassez de professores. Os resultados também destacam a forma como o sensemaking do líder distrital levou à ação, com as respostas diferindo com base nas affordances relativas dos contextos metropolitanos versus rurais. Concluímos com implicações para a política e a pesquisa para entender melhor a natureza local da escassez de professores e para abordar o problema, particularmente em contextos rurais não atendidos pela pesquisa e pela política atuais

Conceptualización del desarrollo profesional en matemáticas: Elementos de un modelo

This theoretical paper discusses the concept of models for mathematics professional development. After examining the related literature, we propose a definition of this concept that includes four elements: goals, theories, contexts, and structure. We present aspects of professional development that comprise each element.En este artículo teórico discutimos sobre el concepto de modelos para el desarrollo profesional en matemáticas. Después de examinar la literatura relacionada, proponemos una definición de este concepto que incluye cuatro elementos: metas, teorías, contextos y estructura. Presentamos los aspectos del desarrollo profesional que abarca cada elemento

The effect of surgical approach on the histology of the femoral head following resurfacing of the hip : analysis of retrieval specimens

Objectives: We aimed to determine the effect of surgical approach on the histology of the femoral head following resurfacing of the hip. Methods: We performed a histological assessment of the bone under the femoral component taken from retrieval specimens of patients having revision surgery following resurfacing of the hip. We compared the number of empty lacunae in specimens from patients who had originally had a posterior surgical approach with the number in patients having alternative surgical approaches. Results: We found a statistically significant increase in the percentage of empty lacunae in retrieval specimens from patients who had the posterior approach compared with other surgical approaches (p < 0.001). Conclusions: This indicates that the vascular compromise that occurs during the posterior surgical approach does have long-term effects on the bone of the femoral head, even if it does not cause overt avascular necrosis

Securing tropical forest carbon: the contribution of protected areas to REDD

Forest loss and degradation in the tropics contribute 6-17% of all greenhouse gas emissions. Protected areas cover 217.2 million ha (19.6%) of the world's humid tropical forests and contain c. 70.3 petagrams of carbon (Pg C) in biomass and soil to 1 m depth. Between 2000 and 2005, we estimate that 1.75 million ha of forest were lost from protected areas in humid tropical forests, causing the emission of 0.25-0.33 Pg C. Protected areas lost about half as much carbon as the same area of unprotected forest. We estimate that the reduction of these carbon emissions from ongoing deforestation in protected sites in humid tropical forests could be valued at USD 6,200-7,400 million depending on the land use after clearance. This is >1.5 times the estimated spending on protected area management in these regions. Improving management of protected areas to retain forest cover better may be an important, although certainly not sufficient, component of an overall strategy for reducing emissions from deforestation and forest degradation (REDD

Performance Metrics for the Objective Assessment of Capacitive Deionization Systems

In the growing field of capacitive deionization (CDI), a number of performance metrics have emerged to describe the desalination process. Unfortunately, the separation conditions under which these metrics are measured are often not specified, resulting in optimal performance at minimal removal. Here we outline a system of performance metrics and reporting conditions that resolves this issue. Our proposed system is based on volumetric energy consumption (Wh/m$^3$) and throughput productivity (L/h/m$^2$) reported for a specific average concentration reduction, water recovery, and feed salinity. To facilitate and rationalize comparisons between devices, materials, and operation modes, we propose a nominal standard testing condition of removing 5 mM from a 20 mM NaCl feed solution at 50% water recovery for CDI research. Using this separation, we compare the desalination performance of a flow-through electrode (fte-CDI) cell and a flow between membrane (fb-MCDI) device, showing how significantly different systems can be compared in terms of generally desirable desalination characteristics. In general, we find that performance analysis must be considered carefully so to not allow for ambiguous separation conditions or the maximization of one metric at the expense of another. Additionally, for context we discuss a number of important underlying performance indicators and cell characteristics that are not performance measures in and of themselves but can be examined to better understand differences in performance

Using a virtual reality cricket simulator to explore the effects of pressure, competition anxiety on batting performance in cricket

Virtual reality (VR) has created opportunities to innovatively re-imagine the way we examine the relations between pressure, competition anxiety and performance. This study aimed to determine the efficacy of VR as a means of measuring the effects of competition anxiety when pressure manipulations are applied while participants bat in a cricket batting VR simulator. The twenty-eight male participants who took part in two experiments were divided into a high (14, mean age: 22.94, SD: 5.4) and a low skill group (14; mean age: 23.55, SD: 9.9). The aim of the first experiment was to validate the VR simulator as a tool that could capture differences in batting performance between a high and low skilled group. The results showed that high skill participants not only scored significantly higher run rates than low skill participants, but they outperformed the low skill group in all performance measures including higher incidences of correct foot placements that reflect better anticipatory responses. Having established the VR batting simulator as being a reliable tool for capturing batting dynamics, experiment 2 aimed to explore the effects of a pressure manipulation on competition anxiety and batting performance. All measures of competition anxiety were significantly greater for both groups in the high-pressure condition compared to the two low-pressure conditions (p &lt; 0.001). The magnitude of this effect was greater in the low skill group for cognitive (0.59) and somatic (0.794) anxiety. Despite anxiety levels significantly increasing in the high-pressure condition, no significant negative changes to batting performance were found for either group, with both groups actually demonstrating performance improvements. Overall, the findings show how a cricket batting virtual reality simulator can be used as a tool to measure the effects of pressure on competition anxiety and batting performance in tasks involving dynamic skill execution.</p