744 research outputs found
Sounding the past: three silent films
The project was an experiment in linking music and poetry to archive films, not only to provide an enhancing accompaniment but, in some cases, with the aim of making something new which would quite profoundly change the way that these films were perceived by audiences
Dot Product Graphs and Their Applications to Ecology
During the past few decades, examinations of social, biological, and communication networks have taken on increased attention. While numerous models of these networks have arisen, some have lacked visual representations. This is particularly true in ecology, where scientists have often been restricted to at most three dimensions when creating graphical representations of pattern and process. I will introduce an application of dot product representation graphs that allows scientists to view the high dimensional connections in ecological networks. Using actual data, example graphs will be developed and analyzed using key measures of graph theory
Crowdsourcing the UK’s constitution: why the status quo is not an option
LSE’s Institute of Public Affairs and Department of Law, and Democratic Audit have recently teamed up for a project which will crowdsource a UK written constitution. In advance of project launch event, Jack Bailey of the LSE Institute of Public Affairs and Sean Kippin of Democratic Audit explain why the current state of affairs is untenable, and how the process of crowdsourcing will work in practice
Peru: Reserve Requirements, GFC
Peru experienced the Global Financial Crisis of 2007–2009 (GFC) in two distinct phases. First, starting in the summer of 2007, record capital inflows to the Peru banking sector contributed to an overheating economy. The Banco Central de Reserva del Perú (BCRP) responded in September 2007 by removing reserve requirements on long-term external credit to promote long-term, rather than short-term, capital inflows. In February 2008, for similar reasons, it began to raise the ordinary minimum reserve requirement on bank liabilities and implemented new marginal reserve requirements on increases in those liabilities. Second, when the collapse of the US investment bank Lehman Brothers in September 2008 exacerbated worldwide liquidity strains, the BCRP reacted by lowering the ordinary reserve requirements to pre-crisis levels and lowering the marginal requirements. In total, the BCRP estimated that the reserve requirement changes injected 2.3 billion soles (USD 752 million) in liquidity, or 0.6% of GDP, between September 2008 and March 2009. Although scholars are divided on the BCRP’s success at limiting credit growth during the first phase, they generally view the liquidity provision during the second phase as successful
Binge Learning – A Conceptual-Developmental Model
Whilst publications exist identifying the concept of binge learning, little consideration has been paid to its alignment with government policy, modern society and technology – effectively its causes and resultant outcomes. This paper provides a conceptual model to explain the underlying causes and net outputs of binge learning, and identifies the social construct faced through its development over time
EMBEDDING CULTURE IN RELATION TO THE SHOTGUN AT THE UNITED STATES NAVAL ACADEMY
The objective of this study was to determine if the randomization of members in an organization can result in a new organizational culture. This study was conducted following the 2021 shotgun of the Brigade of Midshipmen at the United States Naval Academy, where 75 percent of Midshipmen were redistributed into new companies. Different aspects of organizational culture were researched, including the way cultures form, transformational leadership, different configuration models, and Schein’s embedding mechanisms. Focus groups were held for the Midshipmen and their leadership to discuss how the shotgun impacted their company’s culture, if at all. Despite the wide variety of experiences from the Midshipmen, three common themes emerged. Embedding a new culture requires a cohesive environment to create a change, a promulgation of a clear set of goals is needed to align the personnel with the organization, and that establishing a sense of accountability is critical. It was also discovered that a culture would establish itself regardless of the intentionality presented by its members. Limitations of this study included no pre-shotgun data, the voluntary nature of the focus groups, and the sheer amount of data synthesizing required. Recommendations for further attempts of this shotgun should include more oversight to ensure current issues are corrected beforehand, and that new cultures align with the larger organization.Lieutenant, United States NavyLieutenant, United States NavyApproved for public release. Distribution is unlimited
Bipartite Dot Product Graphs
Given a bipartite graph G = (X, Y, E), the bipartite dot product representation of G is a function f : X ∪Y → ℝk and a positive threshold t such that for any x ∈ X and y ∈ Y , xy ∈ E if and only if f(x) · f(y) ≥ t. The minimum k such that a bipartite dot product representation exists for G is the bipartite dot product dimension of G, denoted bdp(G). We will show that such representations exist for all bipartite graphs as well as give an upper bound for the bipartite dot product dimension of any graph. We will also characterize the bipartite graphs of bipartite dot product dimension 1 by their forbidden subgraphs
An Experimental Investigation of Wing-Tip Vortex Decay in Turbulence
Particle image velocimetry measurements were conducted for a wing-tip vortex decaying in free-stream turbulence. The vortex exhibited stochastic collapse with free-stream turbulence present, with the breakdown initiating earlier for higher levels of turbulence. An increased rate of decay of the vortex tangential velocity was also observed, increasing with increasing free-stream turbulence. The decay of the vortex tangential velocity without the free-stream turbulence was well represented by viscous diffusion, resulting in an increase in the core radius and decrease in the peak tangential velocity. With the addition of free-stream turbulence, the rate of decay of the peak tangential velocity of the vortex increases, whereas the rate of increase of core radius remains unchanged. The circulation of the vortex decayed in time when immersed in free-stream turbulence, whereas it remained approximately constant when free-stream turbulence was not present. This decay in circulation was found to be almost entirely due to a decrease in circulation of the vortex core, caused by the relative decrease in the peak tangential velocity without a corresponding increase in the core radius. The scaling of the radial profiles of velocity and circulation was also examined, and it was found that, regardless of the free-stream condition, the core was scaled by the peak tangential velocity and core radius. The region outside the core did not scale with these quantities, and an alternative scaling for circulation is proposed which results in improved collapse of the profiles
Experimental Examination of Vorticity Stripping from a Wing-Tip Vortex in Free-Stream Turbulence
Time-resolved stereoscopic particle image velocimetry measurements were conducted of a wing-tip vortex decaying in free-stream turbulence. The objective of the research was to experimentally investigate the mechanism causing the increased rate of decay of the vortex in the presence of turbulence. It was observed that the circulation of the vortex core experienced periods of rapid loss and recovery when immersed in free-stream turbulence. These events were not observed when the vortex was in a laminar free stream. A connection was made between these events and distortion of the vortex, coinciding with stripping of core fluid from the vortex core. Specifically, vortex stripping events were connected to asymmetry in the vortex core, and this asymmetry was associated with instances of rapid circulation loss. The increased rate of decay of the vortex in turbulence coincided with the formation of secondary vortical structures which wrapped azimuthally around the primary vortex
Inhibition of compensatory survival and proliferative pathway activation induced by mTOR inhibition in renal cell carcinoma
The mammalian target of rapamycin (mTOR) is a key regulator of tumor progression in a variety of cancers and has been shown to be dysregulated in renal cell carcinoma (RCC). mTOR exists in two independent complexes. The mTORC1 complex consists of mTOR, Raptor, and GβL, while the mTORC2 complex consists of mTOR, Rictor, and GβL. Currently there are two FDA approved rapamycin derivatives (rapalogs) for the treatment of advanced renal cell carcinoma (RCC). Allosteric mTOR inhibition (i.e. rapalogs) results in the release of negative feedback inhibition on the PI3K/AKT survival-signaling pathway as well as upregulates the metabolically protective process known as autophagy. Furthermore, catalytic mTOR inhibitors attenuate mTORC1 downstream signaling nodes more completely, but also diminishes mTORC2 mediated AKT survival signals induced by allosteric mTOR inhibitors. Additionally, it has been demonstrated, that mTOR inhibition results in activation of the MEK/MAPK signaling cascade. Based on this information, we wished to interrogate the molecular and biological consequences of inhibiting mTOR pharmacologically and genetically in the context of RCC. We first asked what was the effect of allosteric versus catalytic mTOR inhibition in several conventional human RCC cell lines and novel patient derived xenograft cell lines on mTORC1 and mTORC2 signaling. We saw that only 1) catalytic mTOR inhibition decreased pAKTS473 expression, 2) that both allosteric and catalytic mTOR inhibition increase pERKT202/Y204 expression, and 3) combined MEK and mTOR inhibition induced cell death better than single pathway inhibition alone. Finally, we noted that hierarchal clustering of KIRC_TCGA RPPA (reverse phase protein array) data by markers of mTOR and MEK activation revealed subclasses respective to mTOR and MEK/ERK signaling with significant differences in clinical outcome. We next asked how allosteric versus catalytic mTOR inhibition affected the metabolically conserved process known as autophagy. While both allosteric and catalytic inhibition increased autophagic flux; catalytic mTOR inhibition did so to a greater degree. To determine if this was due to catalytic mTOR inhibitors' ability to attenuate mTORC2 signaling we assessed autophagic flux in cell lines stably expressing shRNAs targeting Raptor or Rictor, essential components for mTORC1 and mTORC2 signaling, respectively. Knock-down of Raptor results in an increase in autophagic flux, however knock-down of Rictor also increases autophagic flux demonstrating that the increased autophagic flux induced by catalytic mTOR inhibition is partly due to inhibition of mTORC2. Finally, we show that catalytic mTOR inhibition in conjunction with autophagy inhibition decreases cellular proliferation while augmenting apoptosis. Together these data support that there are differences in levels of activation of compensatory survival pathways in the context of allosteric and catalytic mTOR inhibition.Doctor of Philosoph
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