4,031 research outputs found
Boardroom Roulette — A Reflective Look at International Goals, Failures, Crises and Remedies in the Field of Corporate Governance
Article published in the Michigan State International Law Review
Transmission of prices and price volatility in Australian electricity spot markets: A multivariate GARCH analysis
This paper examines the transmission of spot electricity prices and price volatility among the five Australian electricity markets in the National Electricity Market (NEM): namely, New South Wales (NSW), Queensland (QLD), South Australia (SA), the Snowy Mountains Hydroelectric Scheme (SNO) and Victoria (VIC). A multivariate generalised autoregressive conditional heteroskedasticity (MGARCH) model is used to identify the source and magnitude of spillovers. The results indicate the presence of positive own mean spillovers in only a small number of markets and no mean spillovers between any of the markets. This appears to be directly related to the limitations of the present system of regional interconnectors. Nevertheless, the large number of significant ownvolatility and cross-volatility spillovers in all five markets indicates the presence of strong ARCH and GARCH effects. Contrary to evidence from studies in North American electricity markets, the results also indicate that Australian electricity spot prices are stationary.spot electricity price markets; mean and volatility spillovers; multivariate GARCH
Renormalization group for measurement and entanglement phase transitions
We analyze the renormalization-group (RG) flows of two effective Lagrangians,
one for measurement induced transitions of monitored quantum systems and one
for entanglement transitions in random tensor networks. These Lagrangians,
previously proposed on grounds of replica symmetry, are derived in a controlled
regime for an illustrative family of tensor networks. They have different forms
in the two cases, and involve distinct replica limits. The perturbative RG is
controlled by working close to a critical dimensionality, for
measurements and for random tensors, where interactions become
marginal. The resulting RG flows are surprising in several ways. They indicate
that in high dimensions there are at least two (stable) universality
classes for each kind of transition, separated by a nontrivial tricritical
point. In each case one of the two stable fixed points is Gaussian, while the
other is nonperturbative. In lower dimensions, , the flow always runs to
the nonperturbative regime. This picture clarifies the "mean-field theory" of
these problems, including the phase diagram of all-to-all quantum circuits. It
suggests a way of reconciling exact results on tree tensor networks with field
theory. Most surprisingly, the perturbation theory for the random tensor
network (which also applies to a version of the measurement transition with
"forced" measurements) formally possesses a dimensional reduction property
analogous to that of the random-field Ising model. When only the leading
interactions are retained, perturbative calculations in dimensions reduce
to those in a simple scalar field theory in dimensions. We show that
this holds to all orders by writing the action in a superspace formulation.Comment: 30 pages, 4 figure
Optimal tempo and defence for consumers of multiple resources
Journal ArticleEcological models of behaviour are typically based on the assumption that decisions can be evaluated with a single resource currency. Here we present models that predict the tactics of consumers collecting two nutritionally distinct resources: fuel that is used for activity and food used for growth (F4G). Both models assume that foragers seek to maximize F4G gain subject to collecting enough fuel for activity
Metabolism And The Rise Of Fungus Cultivation By Ants
Most ant colonies are comprised of workers that cooperate to harvest resources and feed developing larvae. Around 50 million years ago (MYA), ants of the attine lineage adopted an alternative strategy, harvesting resources used as compost to produce fungal gardens. While fungus cultivation is considered a major breakthrough in ant evolution, the associated ecological consequences remain poorly understood. Here, we compare the energetics of attine colony-farms and ancestral hunter-gatherer colonies using metabolic scaling principles within a phylogenetic context. We find two major energetic transitions. First, the earliest lower-attine farmers transitioned to lower mass-specific metabolic rates while shifting significant fractions of biomass from ant tissue to fungus gardens. Second, a transition 20 MYA to specialized cultivars in the higher-attine clade was associated with increased colony metabolism (without changes in garden fungal content) and with metabolic scaling nearly identical to hypometry observed in hunter-gatherer ants, although only the hunter-gatherer slope was distinguishable from isometry. Based on these evolutionary transitions, we propose that shifting living-tissue storage from ants to fungal mutualists provided energetic storage advantages contributing to attine diversification and outline critical assumptions that, when tested, will help link metabolism, farming efficiency, and colony fitness.Integrative Biolog
Optimal non-circular fiber geometries for image scrambling in high-resolution spectrographs
Optical fibers are a key component for high-resolution spectrographs to
attain high precision in radial velocity measurements. We present a custom
fiber with a novel core geometry - a 'D'-shape. From a theoretical standpoint,
such a fiber should provide superior scrambling and modal noise mitigation,
since unlike the commonly used circular and polygonal fiber cross sections, it
shows chaotic scrambling. We report on the fabrication process of a test fiber
and compare the optical properties, scrambling performance, and modal noise
behavior of the D-fiber with those of common polygonal fibers.Comment: 7 pages, 6 figures, submitted to SPIE Astronomical Telescopes &
Instrumentation 2016 (9912-192
A study of controversial literature in the high school English program
Call number: LD2668 .R4 1968 A28
Boardroom Roulette — A Reflective Look at International Goals, Failures, Crises and Remedies in the Field of Corporate Governance
Article published in the Michigan State International Law Review
Terrebonne Farms, Louisiana: an Anthropogeographic Study of a New Deal Resettlement.
This dissertation examines Terrebonne Farms, a 1940\u27s community in south Louisiana established by the federal government during the New Deal period. Planned by the Resettlement Administration and overseen by the Farm Security Administration, the community was one of approximately one hundred experimental towns or resettlements located around the nation. Although these resettlements varied widely in their organization, appearance, and history, few writers have chosen to focus on individual communities. This study combines recollections of original residents and local accounts of Terrebonne Farms with its government records and photographs to create a detailed and contextual description of a single resettlement. In particular, it considers the interplay of government planning with local customs and conditions, and it relates the community to larger social movements such as regionalism and pragmatism
Outer Retinal Structure in Best Vitelliform Macular Dystrophy
Importance Demonstrating the utility of adaptive optics scanning light ophthalmoscopy (AOSLO) to assess outer retinal structure in Best vitelliform macular dystrophy (BVMD).
Objective To characterize outer retinal structure in BVMD using spectral-domain optical coherence tomography (SD-OCT) and AOSLO.
Design, Setting, and Participants Prospective, observational case series. Four symptomatic members of a family with BVMD with known BEST1 mutation were recruited at the Advanced Ocular Imaging Program research lab at the Medical College of Wisconsin Eye Institute, Milwaukee.
Intervention Thickness of 2 outer retinal layers corresponding to photoreceptor inner and outer segments was measured using SD-OCT. Photoreceptor mosaic AOSLO images within and around visible lesions were obtained, and cone density was assessed in 2 subjects.
Main Outcome and Measure Photoreceptor structure.
Results Each subject was at a different stage of BVMD, with photoreceptor disruption evident by AOSLO at all stages. When comparing SD-OCT and AOSLO images from the same location, AOSLO images allowed for direct assessment of photoreceptor structure. A variable degree of retained photoreceptors was seen within all lesions. The photoreceptor mosaic immediately adjacent to visible lesions appeared contiguous and was of normal density. Fine hyperreflective structures were visualized by AOSLO, and their anatomical orientation and size were consistent with Henle fibers.
Conclusions and Relevance The AOSLO findings indicate that substantial photoreceptor structure persists within active lesions, accounting for good visual acuity in these patients. Despite previous reports of diffuse photoreceptor outer segment abnormalities in BVMD, our data reveal normal photoreceptor structure in areas adjacent to clinical lesions. This study demonstrates the utility of AOSLO for understanding the spectrum of cellular changes that occur in inherited degenerations such as BVMD. Photoreceptors are often significantly affected at various stages of inherited degenerations, and these changes may not be readily apparent with current clinical imaging instrumentation
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