The word-level prosodic system of Mangghuer

Mangghuer’s prosodic system has been described as a stress system (Slater 2003), and alternately, because of a few minimal pairs, as a system that is undergoing tonogenesis. (Dwyer 2008). This thesis looks at new data to evaluate both of these claims. I analyze the prosody of native words and confirm that Mangghuer has a stress system. Duration is one of the indicators of stress, which has not been mentioned in previous literature. Potential minimal pairs are considered, including the minimal tone pairs that Dwyer found; her minimal pairs are not minimal pairs in my data. However, one set of nativized Chinese borrowings form a minimal tone pair by contrasting the pitch on the unstressed syllable. There are two pairs of words that have a high/falling distinction on the stressed syllable, which are not perceived as phonemically distinct. The high and the falling pitch distinctions are still associated with stress, but the evidence shows that the stress system is transitioning to a mixed prosodic system that uses both stress and tone

The Use of Native Prairie Grasses to Degrade Atrazine and Metolachlor in Soil

The ability of native prairie grasses, big bluestem (Andropogon gerardii Vitman), Yellow indiangrass (Sorghastrum nutans L.), and switchgrass (Panicum virgatum L.), to degrade atrazine and metolachlor was evaluated in two soils denoted as Alpha and Bravo soils. Vegetation significantly decreased the amount of remaining atrazine in Alpha soil when the concentration of atrazine before vegetation was 93 μg g-1, but had no effect on the degradation of atrazine when it was 4.9 μg g-1. The significant effect of the plants on atrazine degradation in Alpha soil occurred at 57 days after the transplanting of vegetation, but not at 28 days after the transplanting of vegetation. The grasses did not enhance the degradation of atrazine in Bravo soil due to the population of atrazine-degrading microorganisms in that soil. The native prairie grasses had a significant positive effect on the enhanced degradation of metolachlor in both soils, and the significant effect was observed at 28 and 57 days after the transplanting of vegetation in Alpha and Bravo soil, respectively. NH4NO3 had no effect on the degradation of atrazine and metolachlor in either soil. Our results indicate that it is feasible to use the native prairie grasses to help remediate the soils contaminated with high concentrations of atrazine and metolachlor, especially in the absence of the indigenous atrazine or metolachlor degraders

Influence of Microbial Inoculation (Pseudomonas Sp. Strain ADP), the Enzyme Atrazine Chlorohydrolase, and Vegetation on the Degradation of Atrazine and Metolachlor in Soil

The concentrations of atrazine in the freshly added soils and the soils that had been incubated for 50 days significantly decreased 1 day after the addition of the enzyme atrazine chlorohydrolase or the soil bacterium Pseudomonas sp. strain ADP as compared with those in the uninoculated soils. Atrazine chlorohydrolase or ADP had no effect on the degradation of metolachlor. The half-lives of atrazine in the freshly added soils and in the aged soils after the treatment with atrazine chlorohydrolase or ADP markedly decreased as compared with those in the uninoculated soils. The half-lives of metolachlor in the aged soils were much longer than those of freshly added metolachlor. The percentage atrazine degraded in the freshly treated soils was much higher than that in the aged soils. This indicates that aging significantly decreased the bioavailability of atrazine. Vegetation significantly decreased the concentration of metolachlor. However, vegetation showed no effect on the degradation of atrazine

Degradation of Atrazine, Metolachlor, and Pendimethalin in Pesticide‐Contaminated Soils: Effects of Aged Residues on Soil Respiration and Plant Survival

This study was conducted to determine the effects of pesticide mixtures on degradation patterns of parent compounds as well as effects on soil microbial respiration. Bioavailability of residues to sensitive plant species was also determined. Soil for this study was obtained from a pesticide‐contaminated area within an agrochemical dealer site. Degradation patterns were not affected by the presence or absence of other herbicides in this study. Atrazine concentrations were significantly lower at 21 through 160 days aging time compared to day 0 concentrations. Metolachlor and pendimethalin concentrations were not significantly different over time and remained high throughout the study. Microbial respiration was suppressed in treated soils from day 21 to day 160. Soybean and canola were the most successful plant species in the germination and survival tests. Generally, with increased aging of pesticides in soil, germination time decreased. Survival time of plants increased over time for some treatments indicating possible decreased bioavailability of pesticide residues. In some cases, survival time decreased at the longer 160‐day aging period, possibly indicating a change in bioavailability, perhaps as the result of formation of more bioavailable and phytotoxic metabolites. No interactive effects were noted for mixtures of pesticides compared to individually applied pesticides in terms of degradation of the parent compound or on seed germination, plant survival, or microbial respiration

Organic Amendments to Enhance Herbicide Biodegradation in Contaminated Soils

Pesticide contamination of soil and groundwater at agricultural chemical distribution sites is a widespread problem in the USA. Alternatives to land-farming or solid waste disposal include biostimulation and phytoremediation. This research investigated the ability of compost, corn stalks, corn fermentation byproduct, peat, manure, and sawdust at rates of 0.5% and 5% (w/w) to stimulate biodegradation of atrazine [6-chloro-N-ethyl-N′-(1-methyethyl)-1,3,5-triazine-2,4-diamine], metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide], and trifluralin [2,6-dinitro-N,N-dipropyl-4-(trifluoromethyl)benzenamine] added as a mixture to soil. Initial concentrations were 175±42 mg atrazine kg–1 soil, 182±25 mg metolachlor kg–1 soil, and 165±23 mg trifluralin kg–1soil. After amendment addition, 30% of the atrazine, 33% of the metolachlor, and 44% of the trifluralin was degraded over 245 days, which included 63 days\u27 aging prior to amendment additions. Atrazine degradation was enhanced by 0.5% manure, 5% peat, and 5% cornstalk amendments compared to nonamended soils. Metolachlor degradation was enhanced by all amendments at the 5% level, except for compost and peat. Amendments had no effect on trifluralin degradation. The 5% addition of compost, manure, and cornstalks resulted in significant increases in bacterial populations and dehydrogenase activity. A second experiment compared the persistence of atrazine, metolachlor, and trifluralin applied in a mixture to their persistence in soil individually. A combined average of 123 mg atrazine kg–1 remained in soil treated with the three-herbicide mixture compared to 31 mg atrazine kg–1 remaining in soil treated with atrazine only. Atrazine mineralization and atrazine-degrading microorganisms were suppressed by high concentrations of metolachlor, but not by trifluralin

Morbillivirus infections in animal hosts of the Serengeti District of Northern Tanzania: PPRV and CDV in multi-host livestock communities, and CDV in African wild dogs (Lycaon pictus).

Morbilliviruses are responsible for some of the most devastating outbreaks of disease in animals, accompanied by high morbidity and mortality rates. Canine distemper virus (CDV) and peste des petits ruminants virus (PPRV) are highly promiscuous morbilliviruses which have widely expanded their host range in recent decades. However, the extent of infection in atypical hosts and the genetic impact upon endangered, vulnerable species remain poorly understood, particularly in East Africa. The development of a highly accurate serological method capable of differentiating between circulating morbilliviruses is required. Further, the need for longitudinal and clinical monitoring of animals is essential to understand the infection dynamics occurring in susceptible and emerging hosts. Finally, there is a lack of research on the impact which decades of morbillivirus outbreaks have had on the critically endangered African wild dogs of Tanzania, which is paramount to understanding how this species can be further protected and preserved. This thesis comprises two studies. The first study aims to confirm the presence of PPRV and CDV in cattle, sheep, and goats from ten households across the Serengeti District in Northern Tanzania. This work involves a longitudinal serological study underpinning active infection of animals, using a pseudotyped-virus neutralization assay (PVNA) to detect highly specific antibodies to PPRV and to CDV. This study also monitored clinical signs to investigate the disease manifestations of infections in livestock hosts, using a logistic regression model to test for associations between infection and signs of disease in each species. The second study aims to clarify whether genetic change has occurred in the wild dog population of the Serengeti over recent decades, by investigating neutral (microsatellite) and adaptive (MHC DRB1) genetic markers from published data (Marsden et al, 2012), and recently developed data following a fatal CDV outbreak in 2017. It also aims to determine whether there is evidence of natural selection on adaptive markers, and evidence of genetic variation attributable to factors beyond demographic change. Results from these studies demonstrate that cattle in a mixed livestock setting become naturally infected with PPRV with no associated clinical disease. Data also show for the first time that cattle, sheep, and goats become naturally infected with CDV with no associated clinical disease. CDV seropositivity was detected predominantly in cattle. Infections occurred throughout the study with no patterns associated between household and infection, indicating widespread circulation of both viruses beyond the household level. The source of infection remains to be established, although livestock trade and sporadic outbreaks in domestic dogs are likely sources of PPRV and CDV infection, respectively. This work provides strong evidence that PPRV sub-clinically infects cattle in multi-host livestock communities, and that CDV sub-clinically infects livestock, predominantly cattle. This thesis provides the first analysis of genetic changes in the Serengeti population of African wild dogs. This work utilized the pseudotype-based virus neutralization assay to detect CDV-specific neutralizing antibodies in sera of wild dogs which survived the 2017 CDV outbreak, while RT-qPCR was used to detect CDV in tissue samples from deceased wild dogs. Results showed an overwhelming proportion of PCR positives and lack of protective immune response in deceased and surviving animals, respectively. Allele frequency data showed fluctuations in DRB diversity over time coinciding with CDV outbreaks. Heterozygosity varied for both neutral and immune markers over time but showed no excess or evidence of population bottleneck. Bayesian analysis of microsatellites found some genetic structuring over time (K = 2). The test for selection indicated balancing selection during at least two time points at the DRB, in keeping with CDV outbreaks. This study provides strong evidence of population structuring and the potential link between adaptive markers and disease outbreaks in wild dogs

Book Reviews

Reviews of the following books: Joe Scott, The Woodsman-Songmaker by Edward D. Ives; Legacy of a Lifetime: The Story of Baxter State Park by John W. Hakola; General William King: Merchant, Shipbuilder, and Maine\u27s First Governor by Marion Jaques Smith; Picture History of New England Passenger Vessels by W. Bartlett Cram; Colonial Massachusetts: A History by Benjamin Labaree

Mobility and Degradation of Pesticides and Their Degradates in Intact Soil Columns

Laboratory studies were conducted to determine the mobility of parent pesticides and degradation products through the use of large undisturbed soil columns. The influence of vegetation on the mobility of pesticide adjuvants was also investigated. Modifications to the laboratory setup of soil columns for studying various pesticides, degradation products, and adjuvants were done to fit the needs of the particular compound being studied. To improve mass balances of volatile parent compounds, such as methyl bromide, as well as biodegradable (mineralizable) pesticide degradation products such as deethylatrazine, modifications of columns to accommodate isolation of volatile degradation products were accomplished by enclosure of the column head space and use of flow-through systems. Evidence of preferential flow of atrazine, deethylatrazine, metolachlor, and methyl bromide were indicated by the presence of either the 14C-compound or Br-(in the case of methyl bromideapplied soil columns) after the first leaching event. Diffusion through the soil matrix was also evident with a peak of14C in the leachate several weeks after pesticide (or degradate) application to the soil column. Deethylatrazine, a major degradate of atrazine, was more mobile than the parent compound. Vegetation had a significant positive effect on reducing the mobility of the adjuvants propylene glycol and ethylene glycol

Insular cortex dopamine 1 and 2 receptors in methamphetamine conditioned place preference and aversion: Age and sex differences

Rodent studies have proposed that adolescent susceptibility to substance use is at least partly due to adolescents experiencing reduced aversive effects of drugs compared to adults. We thus investigated methamphetamine (meth) conditioned place preference/aversion (CPP/CPA) in adolescent and adult mice in both sexes using a high dose of meth (3 mg/kg) or saline as controls. Mice tagged with green-fluorescent protein (GFP) at Drd1a or Drd2 were used so that dopamine receptor 1 (D1) and 2 (D2) expression within the insular cortex (insula) could be quantified. There are sex differences in how the density of D1+ and D2+ cells in the insula changes across adolescence that may be related to drug-seeking behaviors. Immunohistochemistry followed by stereology were used to quantify the density of cells with c-Fos and/or GFP in the insula. Unexpectedly, mice showed huge variability in behaviors including CPA, CPP, or no preference or aversion. Females were less likely to show CPP compared to males, but no age differences in behavior were observed. Conditioning with meth increased the number of D2 + cells co-labelled with c-Fos in adults but not in adolescents. D1:D2 ratio also sex- and age-dependently changed due to meth compared to saline. These findings suggest that reduced aversion to meth is unlikely an explanation for adolescent vulnerability to meth use. Sex- and age-specific expressions of insula D1 and D2 are changed by meth injections, which has implications for subsequent meth use