Understanding the Impact of Commercial Harvest on White Suckers (Catostomus commersonii) in Maine

The State of Maine issues an unlimited number of commercial permits for the harvest of White Suckers Catostomus commersonii in Maine’s inland waters. The fishery provides a necessary source of fresh lobster Homarus americanus bait to coastal communities at a time when other bait sources are scarce. The impacts of the increasing number of permits and subsequent numbers of fishermen on the white sucker population is unknown. The Maine Department on Inland Fisheries and Wildlife (MDIFW) has closed a number of waters due to concerns that overfishing and incidental catch of other fish species may occur. In Chapter 1, we investigated demographic differences of White Suckers from lakes open to and closed to harvest. Each harvested lake was paired to a lake closed to harvest (reference lake) of similar size. Fish were captured from each lake and biological information was collected for each individual (i.e. sex, mass, gonadosomatic index, fecundity, and age). Distributions of each demographic were compared in a series of paired lake by sex analysis. Fish from harvested lakes were younger, smaller, and had lower fecundity than fish from reference lakes. Estimated mortality rates for harvested lakes were also two fold higher than reference lakes. There were some detectable differences in growth parameters from the von Bertalanffy growth function ( and K) between lake pairs as might occur under selective pressure. White Suckers are long-lived and the few differences found in growth may also reflect the infancy of the fishery (established in 1991). These data do suggest that current levels of exploitation are resulting in age truncation of white sucker populations. In Chapter 2, we built a deterministic population model of White Suckers using parameters from literature and field studies to investigate the theoretical effects of harvest mortality on age-structure and fecundity. We compared the age-structure of White Suckers from our reference lakes to a baseline model and observed and simulated distributions were similar. When harvesting mortality increased in the model there was an expected truncation in age-classes. The average mortality from harvested lakes was used to run the harvest model and the age structure was compared to the aggregate of harvested lakes. A similar age truncation pattern occurred, however distributions were different. This could be due to the variation in the additive mortality estimated for each harvested lake. The results of harvest pressure were evaluated under the assumptions of –both a Beverton-Holt and Ricker recruitment curves. In Chapter 3, we determined the spatial scale of harvesting effort in Maine using commercial sucker permits issued from 2006 to 2016. Of the 7-biological regions managed by MDIFW, Region B had the highest number of permitted waters and Region G had the lowest. A list was also compiled for each biological region for waterbodies with 8 permits (issued in the last 5-years) to provide managers an idea of where to focus efforts for monitoring in future harvest seasons. Possible areas for improvement to aid in management might include the use of a central database for harvesting information, as well as requiring more harvest information from commercial harvesters. It would be advantageous for managers if future commercial sucker report logs were site-specific to inform managers of areas that harvesters repeatedly target. In aggregate, this study provided an important first-look at harvest impacts on white sucker populations in Maine. We now have a better understanding of how White Suckers respond to additive mortality through both field work and deterministic models. The permit analysis also provides managers with specific locations where monitoring efforts could be focused for the next harvest season. Additional data on the number of traps used, where traps are set, effort, and catch total per harvester will be important for future fishery management. Monitoring the age structure of harvested lakes could help assess the viability, productivity, and resilience of white sucker populations. An important next step in the commercial sucker fishery is identifying critical levels of white sucker mortality that cause declines in resilience and productivity, ultimately leading to population collapse

The Real Costs of Corporate Credit Ratings

Credit rating agencies emphasize the importance of specific financial ratio thresholds in their rating process. Firms on the favorable side of these thresholds are more likely to receive higher ratings than similar firms that are not. I show that firms near these salient thresholds respond to the incentive to improve their appearance on this dimension by distorting real investment activities during periods leading up to bond issuance. These firms are significantly more likely to reduce R&D and SG&A expenditures compared to observationally similar firms not near a threshold. Subsequently, they are more likely to experience declines in innovation output, profitability, and Tobin's Q. These distortions highlight an important cost of arms-length financing and an adverse consequence of transparency in credit rating criteria.http://deepblue.lib.umich.edu/bitstream/2027.42/106407/1/1230_Begley.pd

REDUCED FREQUENCY MOTOR STARTING FOR THIRD WORLD POWER SYSTEMS

People in modern industrialized societies live a blessed life relative to those who do not when it comes to some modern conveniences. While many think nothing of flipping on a light switch or running electric appliances, there are people in third world countries could not imagine such things. As service projects are being undertaken to bring such conveniences to those less fortunate, there often is the harsh reality of a strict budget. An item that commands a large portion of said budget is often the diesel generator used to provide the facility with electricity. Generators serving motor loads are typically oversized due to a large kVA starting requirement. This paper addresses an approach to this problem by temporarily restricting the generator fuel supply by pulling back the rack of the mechanical governor reducing the frequency and voltage output as a motor load is switched onto the system. By reducing the voltage and frequency output of the generator, the motor is switched on at a time when its typically poor power factor and resulting kVA requirement is mitigated by the lower voltage and frequency allowing for a smaller generator to be used

Brain natriuretic peptide and NT-proBNP levels reflect pulmonary artery systolic pressure in trekkers at high altitude.

Our objective was to evaluate the utility of the natriuretic peptides BNP (brain natriuretic peptide) and NT-proBNP as markers of pulmonary artery systolic pressure (PASP) in trekkers ascending to high altitude (HA). 20 participants had BNP and NT-proBNP assayed and simultaneous echocardiographic assessment of PASP performed during a trek to 5150 m. PASP increased significantly (p=0.006) with ascent from 24+/-4 to 39+/-11 mm Hg at 5150 m. At 5150 m those with a PASP>/=40 mm Hg (n=8) (versus those with PASP/=400 pg/ml) rise in NT-proBNP at 5150 m (n=4) PASP was significantly higher: 45.9+/-7.5 vs. 32.2+/-6.2 mm Hg (p=0.015). BNP and NT-proBNP may reflect elevated PASP, a central feature of high altitude pulmonary oedema, at HA

Surface ozone in the Colorado northern Front Range and the influence of oil and gas development during FRAPPE/DISCOVER-AQ in summer 2014

High mixing ratios of ozone (O3) in the northern Front Range (NFR) of Colorado are not limited to the urban Denver area but were also observed in rural areas where oil and gas activity is the primary source of O3 precursors. On individual days, oil and gas O3 precursors can contribute in excess of 30 ppb to O3 growth and can lead to exceedances of the EPA O3 National Ambient Air Quality Standard. Data used in this study were gathered from continuous surface O3 monitors for June–August 2013–2015 as well as additional flask measurements and mobile laboratories that were part of the FRAPPE/DISCOVER-AQ field campaign of July–August 2014. Overall observed O3 levels during the summer of 2014 were lower than in 2013, likely due to cooler and damper weather than an average summer. This study determined the median hourly surface O3 mixing ratio in the NFR on summer days with limited photochemical production to be approximately 45–55 ppb. Mobile laboratory and flask data collected on three days provide representative case studies of different O3 formation environments in and around Greeley, Colorado. Observations of several gases (including methane, ethane, CO, nitrous oxide) along with O3 are used to identify sources of O3 precursor emissions. A July 23 survey demonstrated low O3 (45–60 ppb) while August 3 and August 13 surveys recorded O3 levels of 75–80 ppb or more. August 3 exemplifies influence of moderate urban and high oil and gas O3 precursor emissions. August 13 demonstrates high oil and gas emissions, low agricultural emissions, and CO measurements that were well correlated with ethane from oil and gas, suggesting an oil and gas related activity as a NOx and O3 precursor source. Low isoprene levels indicated that they were not a significant contributor to O3 precursors measured during the case studies

A Quantitative Evaluation of Growth in Leptodea Fragilis Before and After the Arrival of Zebra Mussels in Lake Erie

The arrival of zebra mussels in the Great Lakes in the 1980’s marked several environmental changes, most notably in freshwater mussels in the Unionidae. There are no studies of population demographics of native Great Lake species before this period of time. In this study, several recent shell collections of Leptodea fragilis, a fast-growing freshwater mussel, were made on various beaches along Lake Erie. To compare the effects of the zebra mussels on L. fragilis, we compared growth rates, determined from size and estimated age of shells, to additional collections of L. fragilis from 1941 to 1967available at the Cleveland Museum of Natural History. The growth rates of this species are exceptional for their speed among freshwater mussels. A modern comparison of growth rates and age are presented with a sexually dimorphic unionid river species, Lampsilis siliquoidea, that were collected in Summer 2013. We hypothesized that the arrival of zebra mussels could affect the growth rate of L. fragilis by selecting on age of reproduction or growth to reach a minimum size for reproduction, results that could shift growth curves and/or age demography of current populations, and help them persist where zebra mussels remain abundant.https://engagedscholarship.csuohio.edu/u_poster_2013/1006/thumbnail.jp

Cancer Biology Data Curation at the Mouse Tumor Biology Database (MTB)

Many advances in the field of cancer biology have been made using mouse models of human cancer. The Mouse Tumor Biology (MTB, "http://tumor.informatics.jax.org":http://tumor.informatics.jax.org) database provides web-based access to data on spontaneous and induced tumors from genetically defined mice (inbred, hybrid, mutant, and genetically engineered strains of mice). These data include standardized tumor names and classifications, pathology reports and images, mouse genetics, genomic and cytogenetic changes occurring in the tumor, strain names, tumor frequency and latency, and literature citations.

Although primary source for the data represented in MTB is peer-reviewed scientific literature an increasing amount of data is derived from disparate sources. MTB includes annotated histopathology images and cytogenetic assay images for mouse tumors where these data are available from The Jackson Laboratory’s mouse colonies and from outside contributors. MTB encourages direct submission of mouse tumor data and images from the cancer research community and provides investigators with a web-accessible tool for image submission and annotation. 

Integrated searches of the data in MTB are facilitated by the use of several controlled vocabularies and by adherence to standard nomenclature. MTB also provides links to other related online resources such as the Mouse Genome Database, Mouse Phenome Database, the Biology of the Mammary Gland Web Site, Festing's Listing of Inbred Strains of Mice, the JAX® Mice Web Site, and the Mouse Models of Human Cancers Consortium's Mouse Repository. 

MTB provides access to data on mouse models of cancer via the internet and has been designed to facilitate the selection of experimental models for cancer research, the evaluation of mouse genetic models of human cancer, the review of patterns of mutations in specific cancers, and the identification of genes that are commonly mutated across a spectrum of cancers.

MTB is supported by NCI grant CA089713

Regulation of Androgen Receptor Co-Regulators by Activation of the CXCL12/CXCR4 Axis: A Microarray and Proteomics Approach

Background: Activation of the CXCL12/CXCR4 axis is known to stimulate androgen-independent activation of the androgen receptor (AR) in the LNCaP prostate cancer cell line. In the present study, the CXCL12-stimulated expression profile of androgen responsive genes (ARGs) and AR:co-regulator protein:protein interactions has been identified by microarray and proteomic analysis, respectively. Methods: To directly identify proteins that interacted with the AR in response to CXCL12 stimulation, LNCaP cells treated with CXCL12 were subjected to a total proteomics analysis after co-immunoprecipitation (co-IP) with anti-AR antibody. AR- interacting proteins from co-IP were pre-fractionated by SDS-PAGE, in-gel trypsin digested, and analyzed by liquid chromatography coupled to MS (nanoLC-MS/MS). Acquired MS2 data was searched using MASCOT against a SWISSProt human database. Detected proteins were analyzed by spectral counting to qualitatively determine significant changes in protein expression. Results: Gene expression profiling and proteomics analysis of CXCL12-treated LNCaP cells indicated a robust regulation of ARGs, including known AR co-regulators and/or AR-interacting proteins. All known AR co-regulators were extracted and segregated according to their molecular function. GTF2 (Transcription factor), ARID1A (Chromatin Remodeling complex component) and PRDX1 (other function) are the AR co-regulators which showed greater than two fold more interaction with AR in response to CXCL12 treatment, and HNRNPD (Splicing and RNA metabolism) is the protein which is commonly differentially regulated in both microarray and proteomic analysis in response to CXCL12 treatment. The potential role of the above AR co-regulators in promoting the CXCL12- mediated and androgen-independent AR activation and hence the prostate cancer is yet to be elucidated. Conclusions: These data shed new light into the role of ARGs and/or AR Co-regulators in CXCL12- mediated androgen independent activation of AR and suggests new therapeutic targets for the treatment of castration-resistant prostate cancers