Effect of red imported fire ant (Solenopsis invicta Buren) on the nesting success of Northern Bobwhite (Colinus virginianus L.)

The Northern Bobwhite (Colinus virginianus L.) has experienced average yearly decline of 3% in the United States from 1966-2005. Factors implicated in decline include habitat destruction, alteration of farm practices, and red imported fire ant (RIFA) (Solenopsis invicta Buren). Effect of RIFA on bobwhites has been a hot topic leading to formation of polarized camps – those who believe RIFA have little effect and those who believe the effect will further threaten the species’ survival. The main objective of this study was to determine if RIFA affect nesting of bobwhites and at what stage in nesting birds are most vulnerable. Effect of broadcast-spread fire ant bait on RIFA and non-target ant species also was studied. In 2005, eight 4.45 ha plots, each with one aviary housing breeding bobwhites from Louisiana captive stock, were paired by habitat feature. Four plots were broadcast-treated aerially with Amdro® (0.73% hydramethylnon). Sticky traps indicated successful dispersal of bait, although percent composition of particle size on traps differed from that expected. Food traps were used to measure success of RIFA suppression and to determine effect of bait on non-RIFA ants. In 2006, number of plots was reduced to six (three pairs), but number of aviaries per plot increased to four. Two aviaries per plot contained captive-bred bobwhites from Arkansas, whereas the other two contained Louisiana captives. In addition to RIFA, which was successfully suppressed on treated plots, Aphaenogaster fulva-rudis-texana was negatively affected by treatment. Data from other myrmecines suggested similar patterns of decrease by treatment. Only Prenolepis imparis showed a possible competitive release from RIFA. In 2005, lack of nesting reduced number of replicates. One nest hatched successfully; another failed – overrun by RIFA. In 2006, mean number of nests, eggs, and chicks did not differ significantly between treated and untreated plots nor between the two populations of bobwhites. A significantly greater proportion of AR and LA nests were attacked by RIFA on untreated plots. Three nests hatched successfully on treated plots versus one on untreated. RIFA appear to breach intact bobwhite eggshells. In areas of sympatry, RIFA may exacerbate bobwhite decline by attacking eggs prior to hatch

A Study of Dynamical and Emission Variabilities in Pulsars

Pulsars are rapidly rotating highly magnetized neutron stars thought to have been formed in the core-collapse supernova of massive stars. Ever since their discovery, pulsars have shown complex behaviors. This is certainly true for their emission mechanism, which is still not fully understood. This is primarily because of the abrupt changes that appear in the pulse profile. Recent discoveries have shown that these emission changes effect the spin dynamics, particularly the spin-down rate. This indicates that pulsar emissions are even more complex than previously thought. The goal of this thesis is to apply new analysis techniques to help shed light on the pulsar emission problem.;Over the past decade, it has become apparent that a class of `bursting pulsars\u27 exist with the discovery of PSR J1752+2359 and PSR J1938+2213. In these pulsars, a sharp increase in the emission intensity is observed that then tends to systematically drop-off from pulse-to-pulse. We describe the discovery of such a relationship in high-sensitivity observations of the young (characteristic age of 90; 000 yrs) 0.33 s pulsar B0611+22 at both 327 MHz and 1400 MHz with the Arecibo observatory. While it was previously shown that B0611+22 has mode-switching properties, the data presented here show that this pulsar emits bursts with characteristic time-scales of several hundred seconds. At 327 MHz, the pulsar shows steady behavior in one emission mode which is enhanced by bursting emission slightly offset in pulse phase from this steady emission. Contrastingly at 1400 MHz, the two modes appear to behave in a competing operation while still offset in phase. Using a uctuation spectrum analysis, we also investigate each mode independently for sub-pulse drifting. Neither emission mode (i.e. during bursts or persistent emission) shows the presence of the drifting sub-pulse phenomenon. While further examples of this behavior and studies at different wavelengths are required, it appears that this phenomenon may be quite common among the pulsar population.;Until now, PSR J1752+2359 is the only one of the three bursting pulsars that has not been accompanied by a lower energy level normal emission mode. Rather, it has appeared to null between bursting events. We have been able to show through the pulse-energy distribution that PSR J1752+2359 does indeed have a normal mode with a peak flux at 0.17+/-0.3 mJy with a pulse energy of 1.0+/-0.1 muJy-s. It is also shown that PSR J1752+2359 presents no evidence for the drifting sub-pulse phenomenon in either emission mode. This is consistent with what has been seen in PSR B0611+22.;We also present techniques that searched for chaotic behaviors within the spin dynamics of 17 pulsars. These techniques allow us to re-sample the original spin-down rate estimates without losing structural information, and to search for evidence of a strange attractor within these frequency derivative time series. We demonstrate the effectiveness of our methods by applying them to a component of the Lorenz and Rossler attractors that were sampled with similar cadence to the pulsar time series. Our measurements of correlation dimension and Lyapunov exponent show that the underlying behavior appears to be driven by a strange attractor with approximately three governing non-linear differential equations. This is particularly apparent in the case of PSR B1828--11 where a correlation dimension of 2.06+/-0.03 and a Lyapunov exponent of (4.0+/-) x 10-4 inverse days were measured. These results provide an additional diagnostic for testing future models of this behavior.;Lastly, we introduce future plans to further improve our understanding of the bursting phenomena and spin-down rate changes seen here. Simultaneous observations at different frequencies will help determine how a burst is propagating through different emission regions. Along with this, a recent analogous discovery to bursting implies that bursting events may be accompanied by X-ray changes. Scheduled X-ray observations will soon determine if this is true. As data sets cover even larger amounts of time, the non-linear analysis will improve and can be utilized to test theoretical models. We also present data provided by Andrew Lyne that hints at a connection between bursting and spin-down changes

Under-dominance constrains the evolution of negative autoregulation in diploids

Regulatory networks have evolved to allow gene expression to rapidly track changes in the environment as well as to buffer perturbations and maintain cellular homeostasis in the absence of change. Theoretical work and empirical investigation in Escherichia coli have shown that negative autoregulation confers both rapid response times and reduced intrinsic noise, which is reflected in the fact that almost half of Escherichia coli transcription factors are negatively autoregulated. However, negative autoregulation is exceedingly rare amongst the transcription factors of Saccharomyces cerevisiae. This difference is all the more surprising because E. coli and S. cerevisiae otherwise have remarkably similar profiles of network motifs. In this study we first show that regulatory interactions amongst the transcription factors of Drosophila melanogaster and humans have a similar dearth of negative autoregulation to that seen in S. cerevisiae. We then present a model demonstrating that this fundamental difference in the noise reduction strategies used amongst species can be explained by constraints on the evolution of negative autoregulation in diploids. We show that regulatory interactions between pairs of homologous genes within the same cell can lead to under-dominance - mutations which result in stronger autoregulation, and decrease noise in homozygotes, paradoxically can cause increased noise in heterozygotes. This severely limits a diploid's ability to evolve negative autoregulation as a noise reduction mechanism. Our work offers a simple and general explanation for a previously unexplained difference between the regulatory architectures of E. coli and yeast, Drosophila and humans. It also demonstrates that the effects of diploidy in gene networks can have counter-intuitive consequences that may profoundly influence the course of evolution

The Enhanced WUDMA Image Processing System

This document describes recent enhancements to the WUDMA image processing laboratory that implement improvements suggested by experience gained during the WUDMA I program. More recent improvements to the software are mentioned as well as a discussion of some of the design issues faced during the early stages of conception. Finally, some ongoing projects and future plans are mentioned

Privacy and Security Concerns Associated with Mobile Money Applications in Africa

The rapid adoption of mobile money use in Africa raises concerns regarding the privacy and security of users, particularly in light of Financial Action Task Force recommendations requiring user transparency and the collection of transaction data. The transparency required of the now-financially-included—particularly in nations with weak adherence to the rule of law and limited privacy protections—leaves users vulnerable to abuse. Further, the increasing complexity of mobile phone use that is indicative of mobile money applications raises concerns regarding Africa’s preparedness for heightened security threats that come hand in hand with increased use. To address these problems, the authors of this Article recommend specific policy actions by African nations to improve consumer privacy and cybersecurity, supported by policies of industrialized nations like the United States and responsible corporate behavior

The KaVA and KVN Pulsar Project

We present our work towards using the Korean VLBI (Very Long Baseline Interferometer) Network (KVN) and VLBI Exploration of Radio Astronomy (VERA) arrays combined into the KVN and VERA Array (KaVA) for observations of radio pulsars at high frequencies ($\simeq$22-GHz). Pulsar astronomy is generally focused at frequencies approximately 0.3 to several GHz and pulsars are usually discovered and monitored with large, single-dish, radio telescopes. For most pulsars, reduced radio flux is expected at high frequencies due to their steep spectrum, but there are exceptions where high frequency observations can be useful. Moreover, some pulsars are observable at high frequencies only, such as those close to the Galactic Center. The discoveries of a radio-bright magnetar and a few dozen extended Chandra sources within 15 arc-minute of the Galactic Center provide strong motivations to make use of the KaVA frequency band for searching pulsars in this region. Here, we describe the science targets and report progresses made from the KVN test observations for known pulsars. We then discuss why KaVA pulsar observations are compelling.Comment: To appear in PASJ KaVA Special Issu

The WUDMA Image Processing System

The WUDMA Image Processing System provides a framework that allows many image processing packages to function as the single system. It currently contains several packages that provide a powerful range of image processing tools for use in teaching and research. The WUDMA System overcomes the lack of standardization in image processing by providing bridges between diverse software packages and shielding the user from incompatibilities inherent in the software. As such, it may be considered as a paradigm from integrating packages in other application areas

Measuring Supermassive Black Hole Properties via Gravitational Radiation from Eccentrically Orbiting Stellar Mass Black Hole Binaries

There may exist stellar-mass binary black holes (BBH) which merge while orbiting nearby a supermassive black hole (SMBH). In such a triple system, the SMBH will modulate the gravitational waveform of the BBH through orbital Doppler shift and de Sitter precession of the angular momentum. Future space-based GW observatories focused on the milli- and decihertz band will be uniquely poised to observe these waveform modulations, as the GW frequency from stellar-mass BBHs varies slowly in this band while modulation effects accumulate. In this work, we apply the Fisher information matrix formalism to estimate how well space-borne GW detectors can measure properties of BBH+SMBH hierarchical triples using the GW from orbiting BBH. We extend previous work by considering the more realistic case of an eccentric orbit around the SMBH, and notably include the effects of orbital pericenter precession. We find that for detector concepts such as LISA, B-DECIGO, and TianGO, we can extract the SMBH mass and semimajor axis of the orbit with a fractional uncertainty below the 0.1% level over a wide range of triple system parameters. Furthermore, we find that the effects of pericenter precession and orbital eccentricity significantly improve our ability to measure this system. We also find that while LISA could measure these systems, the decihertz detector concepts B-DECIGO and TianGO would enable better sensitivity to the triple's parameters.Comment: 12 pages (main text excluding references and appendices), 11 figures, submitted to PR

Patient as teacher sessions contextualize learning, enhancing knowledge, communication, and participation of pharmacy students in the United Kingdom

Purpose: This study aimed to evaluate the impact of Patient As Teacher (PAT) sessions on the knowledge, communication skills, and participation of pharmacy students in the United Kingdom. Methods: During the academic year 2019-2020, year 1 and 2 pharmacy students at the University of Central Lancashire were invited to complete a questionnaire following PAT sessions. Data were analyzed by means of descriptive statistics, including mean and standard deviation (SD) for: continuous variables and reliability analysis. Pearson’s Chi-Square or Fisher Exact Test, odds ratio, and Phi were used for analyzing dichotomous variables. Thematic analysis was used for free text comments. Results: Sixty eight of 228 students participated, (response rate of 29.8%). No statistical difference was found between gender (p=0.090); a statistically significant difference was found between year (p=0.008). Cronbach's alpha (0.809) confirmed a good internal consistency. 97.0% of the students learned a lot, and 85.3% appreciated and valued the PAT sessions; 89.7% wanted more sessions. 92.7% perceived the sessions to contextualize their learning. Five questions were dichotomized by grouping the responses into negative and positive; 90.3% of responses were positive and did not show statistically significant differences in gender and year of study. Overall students’ free text comments were positive, but active listening and consultation appeared in the positive and negative domains, highlighting the need for more student engagement. Conclusions: PAT sessions had a positive impact on students’ knowledge, communication skills, and participation, and contextualized learning. They provide a valuable contribution to the pharmcy students’ experience in the United Kingdom