18043 research outputs found
Sort by
One-pot enol silane formation-allylation of ketones promoted by trimethylsilyl trifluoromethanesulfonate
Get PDFKetones and related substrate classes undergo enol silane formation in the presence of trimethylsilyl trifluoromethanesulfonate (TMSOTf) and triethylamine, reaction conditions that also promote the in situ ionization of allyl propionates. When these two processes are performed in one pot, allylation of the ketone is observed in high yields. Aldehydes, esters, and thioesters also serve as enol silane precursors under these conditions. When unsymmetrical allyl cations are employed, regioselectivity depends upon the electronic and steric properties of the substituents
The Humanitarian–Development–Peace Nexus in practice: building climate and conflict sensitivity into humanitarian projects
No full textThe concept of the Humanitarian–Development–Peace (HDP) Nexus, also known as the Triple Nexus, developed in response to 21st century realities of climate change, protracted displacement, and the challenge of sustainable development in conflict environments. The HDP Nexus signals a change in the way international assistance is planned and funded, highlighting the need for simultaneously addressing humanitarian assistance, development, and activities that promote peace rather than addressing and conducting them separately or in an iterative fashion. This article is an overview of current thinking on the HDP Nexus and draws attention to its applicability in humanitarian projects occurring in ecologically fragile settings. Since so many humanitarian projects occur in environmentally sensitive areas, many of which are suffering the effects of climate change, addressing natural resources and their protection is a necessary part of the HDP Nexus
Critical edition of Camp-Bell, or the Ironmonger’s Fair Field (author, Anthony Munday) with Mapping Early Modern London
No full textShakespeare and his contemporaries traversed London on foot. Early modern plays, pamphlets, histories, and poems assume intimate knowledge of the streets, alleys, and topography of the city. At Map of Early Modern London (MoEML), our ongoing project is to map the spatial imaginary of Shakespeare’s city; we ask how London’s spaces and places were named, traversed, used, repurposed, and contested by various practitioners (Michel de Certeau’s term), writers, and civic officials. MoEML’s maps allow us to plot people, historical documents, literary works, and recent critical research onto topography and the built environment. At the same time, we experiment with new digital modes of answering GeoHumanities questions. An early contributor to the spatial turn and literary geographic information systems (GIS), MoEML provides a virtual space for exploring the meaning and representation of cultural space in the London of Shakespeare and his contemporaries. We also experiment with new ways of working collaboratively as teams and across institutions and disciplines
Mindsets of poverty: Implications for redistributive policy support
No full textBelief systems impact poverty reduction efforts, as they can enhance, or diminish, support for redistributive economic policies. We examined the predictive utility of mindsets about the changeability (growth mindsets) or the stability (fixed mindsets) of the nature of poverty in society. We conducted six studies, two pre-registered, using both cross-sectional (N = 763) and experimental methods (N = 1361). Growth mindsets of poverty in society predicted greater support for redistributive policies, in part through decreased blame, although there was also a small but unreliable negative indirect effect through social class essentialism. The three experimental studies, each using a different approach, were successful in manipulating mindsets of poverty. However, only the approach leveraging system justifying beliefs had implications for blame, essentialist beliefs, and indirect consequences for policy support. We discuss potential implications of this work for leveraging multiple belief systems to optimally promote support for policies designed to abolish poverty
Physicochemical and Inflammatory Analysis of Unconjugated and Conjugated Bone-Binding Carbon Dots
No full textCarbon nanodots (CDs) have drawn significant attention for their potential uses in diagnostic and therapeutic applications due to their small size, tissue biocompatibility, stable photoluminescence, and modifiable surface groups. However, the effect of cargo molecules on CD photoluminescence and their ability to interact with tissues are not fully understood. Our previous work has shown that CDs produced from the acidic oxidation of carbon nanopowder can bind to mineralized bone with high affinity and specificity in a zebrafish animal model system. Using this model, we investigated the impact of loading Cy5 and biotin cargo on CDs’ photoluminescence and bone-binding properties. We report that CD cargo loading alters CD photoluminescence in a pH- and cargo-dependent manner without interfering with the CDs’ bone binding properties. In a reciprocal analysis, we show that cargo loading of CDs does not affect the cargo’s fluorescence. Significantly, CDs do not trigger nitric oxide production in a mouse macrophage assay, suggesting that they are noninflammatory. Together, these results further support the development of carbon nanopowder-derived CDs for the precise delivery of therapeutic agents to bone tissue
Effects of deforestation and forest degradation on ecosystem service indicators across the Southwestern Amazon
No full textThe Southwestern Amazon (SWA) is home to one of the Earth́s remaining intact ecosystems and a key provider of continental atmospheric moisture flows. However, the integrity of this region is threatened by global changes in climate and local to regional changes in land-use and land-cover. Here, unlike most Amazonia-land-change research which has focused primarily on deforestation, we evaluated the effects of both deforestation and forest degradation on three Ecosystem Service Indicators (ESIs) – evapotranspiration (ET), land surface temperature (LST), and precipitation (P) – at the local and watershed scale across the SWA between 2003 and 2020. We computed annual and monthly ESI differences over distinct forest conditions and buffers around disturbed areas (degraded or deforested). We also determined the influence of forest disturbance trends on ESI trends at the pixel and watershed level through a Partial Mann-Kendall approach. The results show that ESI differences among different forest conditions are statistically-significant and more pronounced during the dry season. In comparison with intact forest, monthly P rates were up to 25 % lower over any type of disturbance; whereas ET rates were up to 15 % and 48 % lower, and LST rates up to 1.6 °C and 4.4 °C higher, over degraded and deforested areas, respectively. ET and LST edge effects were only significant within buffers around some of the most heavily disturbed areas. At the pixel scale, negative trends in ET and positive trends in both LST and P were more frequently explained by forest disturbances as these trends themselves become more pronounced. ET and LST trends determined by disturbances were generally located near roads, rivers, and human settlements; and surprisingly, we found that degradation more often influences these trends than deforestation, which we attribute to the practice of converting deforested areas into crops whose growing season ET and LST rates are similar to those in natural vegetation. At the watershed scale, the analysis suggested that the climate implications of degradation and deforestation have not scaled up to this level yet; however, literature has shown that even the local impacts we report here can have important implications for areas outside of the SWA, which emphasizes the importance of continuing to conserve this remote region
Block symmetries in graph coloring reconfiguration systems
No full textIn this paper, we study reconfiguration systems for proper graph colorings modified by single-vertex recolorings. Applying a general construction of Ghrist and Peterson[15] to the graph coloring problem, we consider cubical complexes in which cubes represent recolorings of independent sets of vertices. For any choice of base graph and number of colors, the 0-skeleton of the associated coloring state complex is the set of proper colorings, and the 1-skeleton is the transition graph. Appealing to symmetries induced by color permutation, we give two main results regarding the organization of the biconnected components (blocks) of coloring transition graphs and the colorings within those blocks. First, the 1-skeleton of any connected coloring state complex has a unique block whose vertex set is the union of entire classes of isomorphic colorings. We call this block the nucleus. Second, the nucleus of the state complex of any non-empty graph contains a non-trivial cycle. This implies that although the state complex for any reconfiguration system is locally CAT(0)[15], only the very simplest coloring state complexes are globally CAT(0)
Educators’ Perspectives of Using (or Not Using) Online Exam Proctoring
No full textThe onset of the COVID-19 pandemic changed the land- scape of education and led to increased usage of remote proc- toring tools that are designed to monitor students when they take assessments outside the classroom. While prior work has explored students’ privacy and security concerns regard- ing online proctoring tools, the perspective of educators is under explored. Notably, educators are the decision makers in the classrooms and choose which remote proctoring ser- vices and the level of observations they deem appropriate. To explore how educators balance the security and privacy of their students with the requirements of remote exams, we sent survey requests to over 3,400 instructors at a large private university that taught online classes during the 2020/21 aca- demic year. We had n = 125 responses: 21% of the educators surveyed used online exam proctoring services during the remote learning period, and of those, 35% plan to continue using the tools even when there is a full return to in-person learning. Educators who use exam proctoring services are of- ten comfortable with their monitoring capabilities. However, educators are concerned about students sharing certain types of information with exam proctoring companies, particularly when proctoring services collect identifiable information to validate students’ identities. Our results suggest that many ed- ucators developed alternative assessments that did not require online proctoring and that those who did use online proctoring services often considered the tradeoffs between the potential risks to student privacy and the utility or necessity of exam proctoring services
Expert and novice evaluations of piano performances: Criteria for computer-aided feedback
No full textLearning an instrument can be rewarding, but is unavoid- ably a huge undertaking. Receiving constructive feedback on one’s playing is crucial for improvement. However, per- sonal feedback from an expert instructor is seldom avail- able on demand. The goal motivating this project is to build software that will provide comparably useful feed- back to beginners, in order to supplement feedback from human instructors. To lay the groundwork for that, in this paper we investigate performance assessment criteria from both quantitative and qualitative perspectives. We gathered 83 piano performances from 21 players. Each recording was evaluated by both expert piano instructors and novice players. This dataset is unique in that the novice evalua- tors are also players, and that both quantitative and quali- tative evaluations are collected. Our analysis of the eval- uations indicates that the kind of specific, concrete piano techniques that are most elusive to novice evaluators are precisely the kind of characteristics that can be detected, measured, and visualized for learners by a well-designed software tool
Families Formed, Found, and Fractured in the Children\u27s Novels of Frances Hodgson Burnett
No full textThis chapter discusses the ways families are configured and reconfigured in Frances Hodgson Burnett\u27s three major novels for children, A Little Princess, The Secret Garden, and Little Lord Fauntleroy. Burnett\u27s novels, though well known, are too often slotted into the ‘nostalgic’ category of children\u27s literature, without thorough examination. Yet her children are remarkably agentic. Unable to ‘fit’ in their English families, they create found families from the friends they make—other children, schoolfriends, servants, even animals—and repair the failures of their families by telling new stories rather than following in their footsteps. In Burnett\u27s novels, imagination and ‘maternal’ care, along with the vital energy of colonial children, restore and reform the English family