Birds of Light

Autumn streams of rain hit the maple tree and red and yellow leaves wing off in all direction

Sparse Representations in Power Systems Signals

This thesis seeks to detect transient disturbances in power system signals in a sparse framework. To this end, an overcomplete wavelet packet dictionary and damped sinusoid dictionary are considered, and for each dictionary Matching Pursuit is compared with Basis Pursuit. Previous work in developing waveform dictionary theory and sparse representation is reviewed, and simulations are run on a test signal in both noisy and noiseless environments. The solutions are viewed as time-frequency plane tilings to compare the accuracy and sparsity of these algorithms in properly resolving optimal representations of the disturbances. The advantages and disadvantages of each combination of dictionary and algorithm are presented

Festina Lente

I once laid a stone path in the yard and unearthed a spadefoot toad in hibernatio

On the Move

Arriving I caught the bus to the beach under a blue and white sky and sat behind five or six rider

Promise

Her hands looked old boney and bruised but her face young her cheeks blushed her eyes wanderin

Policing Power: Essays on Coercion, Corruption, and the State

This dissertation is about how the state influences individuals’ behavior by giving certain citizens the legal and physical means to coerce other citizens. Using field experimentation, participatory observation, and time-series analysis of two large sets of micro-data on crime to study policing in West Africa and Melanesia, the findings challenge conventional wisdom about the relationship between coercion, corruption, and the state. Empowering women by sending police officers to assist them in disputes with men may not necessarily reduce gender-based coercion, because men can preserve their privileges by drawing on alternative authorities. Conferring police officers powers to coerce other people does not necessarily induce corrupt behavior, because conferral of power may cause them to care more about their reputation than the rents they can extract. Competitive elections may not reduce petty police corruption even if they make principals accountable; instead, elections may incentivize corruption by increasing agents’ uncertainty about how principals will act in the future. These findings contribute new insights to the theory of state-building, accountability, and bureaucratic politics

F22RS SGCR 53 (SG Fee Referendum)

TO PLACE A REFERENDUM BEFORE THE LOUISIANA STATE UNIVERSITY STUDENT BODY IN THE FALL 2022 ELECTION TO AMEND THE SELF-ASSESSED STUDENT GOVERNMENT FEE TO $3.50 PER FULL TIME STUDEN

Body dimensions of the extinct giant shark Otodus megalodon: a 2D reconstruction

Inferring the size of extinct animals is fraught with danger, especially when they were much larger than their modern relatives. Such extrapolations are particularly risky when allometry is present. The extinct giant shark †Otodus megalodon is known almost exclusively from fossilised teeth. Estimates of †O. megalodon body size have been made from its teeth, using the great white shark (Carcharodon carcharias) as the only modern analogue. This can be problematic as the two species likely belong to different families, and the position of the †Otodus lineage within Lamniformes is unclear. Here, we infer †O. megalodon body dimensions based on anatomical measurements of five ecologically and physiologically similar extant lamniforms: Carcharodon carcharias, Isurus oxyrinchus, Isurus paucus, Lamna ditropis and Lamna nasus. We first assessed for allometry in all analogues using linear regressions and geometric morphometric analyses. Finding no evidence of allometry, we made morphological extrapolations to infer body dimensions of †O. megalodon at different sizes. Our results suggest that a 16 m †O. megalodon likely had a head ~ 4.65 m long, a dorsal fin ~ 1.62 m tall and a tail ~ 3.85 m high. Morphometric analyses further suggest that its dorsal and caudal fins were adapted for swift predatory locomotion and long-swimming periods

The extinct marine megafauna of the Phanerozoic

The modern marine megafauna is known to play important ecological roles and includes many charismatic species that have drawn the attention of both the scientific community and the public. However, the extinct marine megafauna has never been assessed as a whole, nor has it been defined in deep time. Here, we review the literature to define and list the species that constitute the extinct marine megafauna, and to explore biological and ecological patterns throughout the Phanerozoic. We propose a size cut-off of 1 m of length to define the extinct marine megafauna. Based on this definition, we list 706 taxa belonging to eight main groups. We found that the extinct marine megafauna was conspicuous over the Phanerozoic and ubiquitous across all geological eras and periods, with the Mesozoic, especially the Cretaceous, having the greatest number of taxa. Marine reptiles include the largest size recorded (21 m; Shonisaurus sikanniensis) and contain the highest number of extinct marine megafaunal taxa. This contrasts with today’s assemblage, where marine animals achieve sizes of >30 m. The extinct marine megafaunal taxa were found to be well-represented in the Paleobiology Database, but not better sampled than their smaller counterparts. Among the extinct marine megafauna, there appears to be an overall increase in body size through time. Most extinct megafaunal taxa were inferred to be macropredators preferentially living in coastal environments. Across the Phanerozoic, megafaunal species had similar extinction risks as smaller species, in stark contrast to modern oceans where the large species are most affected by human perturbations. Our work represents a first step towards a better understanding of the marine megafauna that lived in the geological past. However, more work is required to expand our list of taxa and their traits so that we can obtain a more complete picture of their ecology and evolution