Weak convergence of the localized disturbance flow to the coalescing Brownian flow

We define a new state-space for the coalescing Brownian flow, also known as the Brownian web, on the circle. The elements of this space are families of order-preserving maps of the circle, depending continuously on two time parameters and having a certain weak flow property. The space is equipped with a complete separable metric. A larger state-space, allowing jumps in time, is also introduced, and equipped with a Skorokhod-type metric, also complete and separable. We prove that the coalescing Brownian flow is the weak limit in this larger space of a family of flows which evolve by jumps, each jump arising from a small localized disturbance of the circle. A local version of this result is also obtained, in which the weak limit law is that of the coalescing Brownian flow on the line. Our set-up is well adapted to time-reversal and our weak limit result provides a new proof of time-reversibility of the coalescing Brownian flow. We also identify a martingale associated with the coalescing Brownian flow on the circle and use this to make a direct calculation of the Laplace transform of the time to complete coalescence.Comment: Published at http://dx.doi.org/10.1214/13-AOP845 in the Annals of Probability (http://www.imstat.org/aop/) by the Institute of Mathematical Statistics (http://www.imstat.org). arXiv admin note: substantial text overlap with arXiv:0810.021

The Clean Air Act Amendments and Firm Investment in Pollution Abatement Equipment

The command-and-control approach to environmental regulation requires that firms install prescribed technologies to meet specified goals. However, environmental regulations change frequently; in addition, the enforcement agency cannot perfectly monitor firm compliance. We examine the impact of uncertainties surrounding the enactment and the enforcement of the Clean Air Act Amendments of 1990 on firm investment in air pollution abatement equipment. We find that our measures of the likelihood of CAAA passage clearly affect a firm's investment in pollution equipment. Enforcement actions also affect a firm's investment, but these effects are weaker and are statistically significant only after enactment

Bioaccumulation of Microcystins by Freshwater Mussels in Mystic Lake and Middle Pond, MA

The UNH Center for Freshwater Biology investigated a possible relationship between a cyanobacteria bloom and a large-scale die-off of freshwater mussels in Mystic Lake and Middle Pond (Barnstable, MA). Four mussel species, Elliptio complanata (Eastern Elliptio), Pyganodon cataracta (Eastern Floater), Leptodea ochracea (Tidewater Mucket), and Lampsilis radiata (Eastern Lampmussel) (Nedeau, 2008), along with water samples, were collected from these lakes on August 9, 2010 (during bloom) and again on September 29 and October 8, 2010 (post-bloom). Hepatopancreas tissue, foot tissue, and water samples were tested for the cyanobacteria toxins, microcystins (MC), using ELISA techniques. MC concentrations in the hepatopancreas were generally higher (171.2 ng MC g-1 dry weight (dw)) than in the muscle (foot) tissue (55.8 ng MC g -1 dw) for each species. Average microcystin concentrations in mussels sampled during postbloom tissues were slightly lower (161.6 ng MC g-1 dw) than those collected during the cyanobacteria bloom (171.2 ng MC g1 dw). Live mussels were also subjected to a depuration experiment to determine the release of MC from mussels into the water. Mussels that were placed in cyanobacteria-free water depurated 61-90% MC within the first few days demonstrating their ability to release free MC-cyanotoxins into the lake water

Effect of competitive cues on reproductive morphology and behavioral plasticity in male fruitflies

Phenotypic plasticity will be favored whenever there are significant fitness benefits of responding to environmental variation. The extent and nature of the plasticity that evolves depends on the rate of environmental fluctuations and the capacity to track and respond to that variability. Reproductive environments represent one arena in which changes can be rapid. The finding that males of many species show morphological, physiological, and behavioral plasticity in response to premating and postmating reproductive competition (RC) suggests that plasticity is broadly beneficial. The developmental environment is expected to accurately predict the average population level of RC but to be a relatively poor indicator of immediate RC at any particular mating. Therefore, we predict that manipulation of average RC during development should cause a response in plasticity “set” during development (e.g., size of adult reproductive structures), but not in flexible plasticity determined by the immediate adult environment (e.g., behavioral plasticity in mating duration). We tested this prediction in Drosophila melanogaster males by manipulating 2 independent cues of average RC during development: 1) larval density and 2) the presence or absence of adult males within larval culture vials. Consistent with the prediction, both manipulations resulted in the development of males with significantly larger adult accessory glands (although testis size decreased when males were added to culture vials). There was no effect on adult plasticity (mating duration, extended mating in response to rivals). The results suggest that males have evolved independent responses to long- and short-term variation in RC

Effect of competitive cues on reproductive morphology and behavioral plasticity in male fruitflies

Phenotypic plasticity will be favored whenever there are significant fitness benefits of responding to environmental variation. The extent and nature of the plasticity that evolves depends on the rate of environmental fluctuations and the capacity to track and respond to that variability. Reproductive environments represent one arena in which changes can be rapid. The finding that males of many species show morphological, physiological, and behavioral plasticity in response to premating and postmating reproductive competition (RC) suggests that plasticity is broadly beneficial. The developmental environment is expected to accurately predict the average population level of RC but to be a relatively poor indicator of immediate RC at any particular mating. Therefore, we predict that manipulation of average RC during development should cause a response in plasticity “set” during development (e.g., size of adult reproductive structures), but not in flexible plasticity determined by the immediate adult environment (e.g., behavioral plasticity in mating duration). We tested this prediction in Drosophila melanogaster males by manipulating 2 independent cues of average RC during development: 1) larval density and 2) the presence or absence of adult males within larval culture vials. Consistent with the prediction, both manipulations resulted in the development of males with significantly larger adult accessory glands (although testis size decreased when males were added to culture vials). There was no effect on adult plasticity (mating duration, extended mating in response to rivals). The results suggest that males have evolved independent responses to long- and short-term variation in RC

Rural Primary Care and the Diagnostic Resolution of Abnormal Screening Mammograms: A Mixed Methods Study in Rural Missouri

Rural health clinics (RHCs) and federally qualified health centers (FQHCs) play a vital role in initiating cancer screening in underserved, rural settings. Yet there is limited information about their involvement in diagnostic tests when a mammogram result is abnormal. Diagnostic resolution of abnormal mammograms varies widely by geographic location and resources, and timely resolution is important for addressing rural-urban cancer disparities. This mixed methods study in a rural region of Missouri with high rates of cancer mortality examined the roles of primary care providers during follow-up after an abnormal mammogram, the processes they used, and the clinic specific variations among these roles and processes. Our data show substantial involvement of primary care during follow-up, with differences in resources and formalized and informal strategies between FQHCs and RHCs. Elucidating roles and processes is a necessary step before evidence based strategies, often developed in urban settings, can be adapted for rural settings

Toxic Cyanobacteria Aerosols: Tests of Filters for Cells

Aerosolization of toxic cyanobacteria released from the surface of lakes is a new area of study that could uncover a previously unknown route of exposure to toxic cyanobacteria. Since toxic cyanobacteria may be responsible for adverse human health effects, methods and equipment need to be tested and established for monitoring these airborne bacteria. The primary focus of this study was to create controlled laboratory experiments that simulate natural lake aerosol production. I set out to test for the best type of filter to collect and analyze the aerosolized cells as small as 0.2-2.0 µm, known as picoplankton. To collect these aerosols, air was vacuumed from just above a sample of lake water passing through either glass fiber filters (GFF) or 0.22 µm MF-Millipore™ membrane filters (0.22 Millipore™). Filter collections were analyzed through epiflourescence microscopy for determining cell counts. Data analysis revealed that 0.22 Millipore™ filters were the best option for cell enumeration providing better epiflourescence optical quality and higher cell counts

The spatial variation of low birth weight infants in Windsor and Essex County, 1986.

Dept. of Geography. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1989 .J35. Source: Masters Abstracts International, Volume: 40-07, page: . Thesis (M.A.)--University of Windsor (Canada), 1989

Less class, more sass!

Less Class, More Sass! is a visual soundtrack to the crass jokes, hairy faces and smelly wardrobes of my disorderly, and politically incorrect friends. These young men and women have mutated into a ragged crew of personified sasquatches to tell a collection of stories about coming of age in the American punk and metal music subcultures. In this series of prints the characters grow from aimlessly rebellious youths into hopeless but happy young adults, ashamed of their desires for a nice neighborhood and a steady job. While thrashing through a sea of self-destructive tendencies, each character slowly finds their inner resilience empowering them to stay afloat and keep swimming

Efficient size estimation and impossibility of termination in uniform dense population protocols

We study uniform population protocols: networks of anonymous agents whose pairwise interactions are chosen at random, where each agent uses an identical transition algorithm that does not depend on the population size $n$. Many existing polylog$(n)$ time protocols for leader election and majority computation are nonuniform: to operate correctly, they require all agents to be initialized with an approximate estimate of $n$ (specifically, the exact value $\lfloor \log n \rfloor$). Our first main result is a uniform protocol for calculating $\log(n) \pm O(1)$ with high probability in $O(\log^2 n)$ time and $O(\log^4 n)$ states ($O(\log \log n)$ bits of memory). The protocol is converging but not terminating: it does not signal when the estimate is close to the true value of $\log n$. If it could be made terminating, this would allow composition with protocols, such as those for leader election or majority, that require a size estimate initially, to make them uniform (though with a small probability of failure). We do show how our main protocol can be indirectly composed with others in a simple and elegant way, based on the leaderless phase clock, demonstrating that those protocols can in fact be made uniform. However, our second main result implies that the protocol cannot be made terminating, a consequence of a much stronger result: a uniform protocol for any task requiring more than constant time cannot be terminating even with probability bounded above 0, if infinitely many initial configurations are dense: any state present initially occupies $\Omega(n)$ agents. (In particular, no leader is allowed.) Crucially, the result holds no matter the memory or time permitted. Finally, we show that with an initial leader, our size-estimation protocol can be made terminating with high probability, with the same asymptotic time and space bounds.Comment: Using leaderless phase cloc