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A genetic and molecular investigation of the circadian and circatidal clocks in the Horseshoe crab, Limulus polyphemus
Get PDFBiological rhythms are cyclical behavioral and/or physiological changes that are driven by endogenous biological clocks. The most common type of rhythm, known as a circadian rhythm, oscillates with a period of about 24 hours. The endogenous clock that modulates circadian rhythms is composed of a set of core" and accessory circadian genes. The core genes in animals are clock cycle period nonphotoreceptive-cryptochrome2 and timeless and appear to be self-regulated by transcription-translation negative feedback loops thus allowing for synchronization and anticipation of the daily light and dark changes. Organisms that live in or visit the intertidal areas are also exposed to another type of environmental rhythm which corresponds to the rise and fall of oceanic tides. Tidal rhythms are well documented in several intertidal animals yet unlike circadian rhythms the molecular basis of the tidal clock system is largely unknown. One intertidal organism the Atlantic horseshoe crab Limulus polyphemus is an important keystone species and has robust circadian and circatidal rhythms which makes it a potential model system for the study of these rhythms and the mechanisms of the clocks that drive them. The aims of this thesis are:(1) to create Limulus genomic and transcriptomic datasets and (2) to investigate the presence of core clock gene homologs in the brain of Limulus as well as examine their potential modulation by time of day and time of tide. In these studies the central nervous system of Limulus was used to develop a draft genome and transcriptome of this species. Four adult horseshoe crabs were selected and total RNA was extracted from their central nervous systems during the day and night and during high and low tides. Illumina library preparation sequencing subsequent assembly and RNA-seq investigations indicated the presence of virtually all of the core clock gene homologs and accessory genes although with there was no clear rhythmic cycling of the transcription of any circadian core or accessory gene. Interestingly total transcript expression showed more high versus low tidal phase differences than light versus dark photoperiodic differences. Additionally the majority of the genes that seemed to be regulated according to these conditions did not have homologs in public bioinformatics databases suggesting that these rhythmic genes are novel and currently unique to Limulus. Using data from the genome and transcriptome as a guide for primer design QPCR was used to further explore the expression of the putative core circadian genes clock npcryptochome2 cycle1 and timeless in the protocerebrum over conditions of photoperiod and tidal phase. To accomplish this aim horseshoe crabs were placed into tide-simulating tanks and were subjected to light/dark and tidal cycles. QPCR was performed on the mRNA extracts from the central nervous system to quantify the expression of the circadian clock genes clock cycle1 timeless and npcryptochrome2over photoperiodic and tidal conditions. While core circadian transcripts were found to be expressed in all investigated sections of the central nervous system there were nostatistically significant rhythmic cycling of those genes within the protocerebrum with respect to either photoperiod or tidal phase. Overall both the RNA-seq and QPC Rresults suggest a relatively constitutive expression of core circadian transcripts within the Limulus central nervous system. These results when taken together suggest at least five possible explanations; (1) These genes may not be involved with the circadian or tidal clocks; (2) Rhythmic mRNA expression of these genes may not be necessary for these clocks; (3) The circadian and tidal clocks share some genes and them RNA of those shared genes oscillates out of phase with each other masking true rhythmic expression; (4) Non-clock cells in the tissues examined are also expressing these genes at a high enough level to "dilute" the rhythms of mRNA expression; (5) Finally there may be a heavy reliance of Limulus clocks on post-transcriptional and post-translational modifications. In order to explore some of these potential explanations future studies should aim to systematically investigate putative circadian genes in Limulus. This will help to determine whether or not these genes are involved with one or more of these clocks and whether or not their transcription is required for measurable rhythms.Electronic Thesis or Dissertatio
Soil condition and morphology on hiking trails in the White Mountains Region
Get PDFMaintaining certain conditions on a trail's surface is essential for a trail to function properly and serve its purpose of transporting hikers and other trail users. Understanding how trail design influences erosion and changes to the soil condition of a trail is critical to building and maintaining trails with sustainable surface conditions. Published practices for controlling water erosion on trails are based on hypotheses about length of slope and drainage area that are understudied or not studied at all. To test these hypotheses, this study applies the stream power equation to erosion on trails. This novel approach to multivariate modeling of trail design variables reveals that drainage area and length of slope have positive logarithmic effects on erosion. Trail slope was observed to have an exponential relationship with erosion when modeled independently of other variables, but a linear relationship with erosion when mediated by drainage area. Three on-trail soil conditions -- organic content, compaction, and particle size -- were measured along with design variables and erosion. Organic content showed the strongest correlation with these variables.Electronic Thesis or Dissertatio
A novel way to construct the Fibonacci sequence and the uni-phi-cation of mathematics and physics
Get PDFWhen the Fibonacci number sequence is based on the number seven and its multiples, the Fibonacci sequence self-reflexively reappears when differences are calculated between it and this new number-seven-based Fibonacci sequence. The same thing happens with Lucas numbers. Can this same procedure be applied to any two numbers at the beginning of a Fibonacci/Lucas-like sequence? The answer is in the negative. This special quality of the golden proportion casts light on the fine structure constant of hydrogen, which is the unique, lightest, and most pervasive element in nature, plus other constants in nature, all of which have a dimensionless number close to the golden proportion (Phi) of the Fibonacci sequence, and provides the basis for the binary computer code as well as a uni-Phi-ed theory of mathematics and physics.Article
Hindsight: how prepared did corporate CEOs believe they were to lead as presidents of colleges and universities?
No full textThe purpose of this multi-case study was to explore the experiences of college presidents who have held top executive level positions at both academic and corporate institutions and who ascended to their college presidency from a role outside higher education. Through this study, the researcher ascertained from the presidents how prepared they believed they were to assume the role of president and uncovered what these particular leaders perceived as the similarities and differences in leading a college and a corporation. Seven presidents from colleges and universities in New England participated in this study. All of the presidents interviewed indicated that they felt prepared to assume the role of president from their former leadership position outside higher education. They described two main areas of preparedness: their own prior engagement in higher education and the match of their strengths to the needs of the institution. The similarities and differences described by the presidents were in the areas of finances, faculty and outcomes. The presidents spoke specifically about the attributes of professionals they believed would be successful in making a transition from a corporate environment to higher education, which included being open-minded, being collaborative, and having a passion for the mission. The results of this study may benefit Board of Trustees who are considering non-academic candidates for the role of president and current corporate CEOs who are considering transitioning to a leadership position in higher education.Electronic Thesis or Dissertatio
A time series observation of two stream communities: disturbance, seasonal variation, and macroinvertebrate assemblages
Get PDFMacroinvertebrate surveys offer a rapid and cost-effective approach for research linking hydrological indices with biological communities in streams. While macroinvertebrates have been successfully used to describe water quality, only recently has research demonstrated their use for describing flow regime. The intent of my research was to describe the response of benthic communities in headwater streams to seasonal and hydrological variation. In 2014, I sampled two streams biweekly in the Hubbard Brook Experimental Forest in New Hampshire from stream thaw in early April until streams froze in late December. I found changes in taxonomic and functional membership and assemblage rheophily in apparent response to hydrological disturbance. Assemblage response patterns to high flow were similar at both sites for a period of approximately five days. Beyond five days, the recovery was unique to each site, however, and emphasized the importance of considering both the spatial and temporal nature of lotic environments when describing benthic communities. These findings become more important as effective policy-making in the face of a changing climate and continuing human impacts requires thorough understanding of abiotic influences on our aquatic communities.Electronic Thesis or Dissertatio
Evaluating the ecosystem service of nutrient removal in a coastal watershed: a case study of New Hampshire's Great Bay
Get PDFNew Hampshire's Great Bay, valued as one of 28 "estuaries of national significance," provides a host of economic, ecological, and social environmental services that are threatened by the deterioration of water quality and increased levels of nitrogen. The US Environmental Protection Agency has issued several National Pollutant Discharge Elimination System permits that mandate the reduction of point source pollution to the limits of technology. In order to meet the new strict permit limits, the aging built infrastructure must be updated, and the combined capital costs are about $354 million (Kessler, 2010). Alternatives, such as land conservation and natural infrastructure, provide ways of reducing nitrogen sources from nonpoint source pollution. Relying on expert stakeholder input, we developed two land use scenarios to model potential nitrogen reduction or input under increased conservation or increased development. Two modeling programs, the river network ecosystem model Framework for Aquatic Modeling of the Earth System (FrAMES) and the Natural Capital Project's Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) nutrient retention model, were utilized to execute the stakeholder-based scenarios. Holding point sources constant, FrAMES predicts that an average of 28.1 tons TN/yr and InVEST predicts that 3.1 tonsTN/yr or more will be added to the system per year under an increased development scenario compared to an increased conservation scenario. If Epping, a town in the Great Bay Watershed, upgraded its wastewater treatment facility to the limits of technology, it would remove an estimated additional 2.99 metric tons TN/yr (Kessler, 2010). A conservative estimate of the effect of realistic land conservation efforts across the watershed would provide analogous benefits to the town of Epping upgrading to the best available wastewater technology. The FrAMES estimate of 28.1 tons TN/yr is comparable to upgrading the Newmarket wastewater treatment facility, which will keep 26.5 tons TN/yr from entering the Great Bay Estuary.Electronic Thesis or Dissertatio
The open anthology of earlier American literature
Get PDFThis is an anthology of public domain texts from earlier American literature, collected by students, faculty, and alumnae of Plymouth State University as an OER alternative to expensive commercial anthologies. The project is now developing through the Rebus Community, under the direction of managing editor Timothy Robbins, so users are encouraged to visit Rebus online to find additional information about and subsequent iterations of this book.
This work is also available on the Pressbooks platform at https://openamlit.pressbooks.com
Healing trauma among female prisoners through mindfulness: a phenomenological study
Get PDFThe connection between trauma and criminal behavior has been well documented in the literature, as are quantitative data on the impact of wellness training in assisting prisoners with trauma recovery. However, there is a dearth of research exploring the perceptions of female prisoners. This research represents a first attempt to qualitatively explore the mental health needs and wellness-based treatment of female prisoners with a history of trauma. Statistics regarding both trauma and mental illness among the prison population were reviewed, as well as the rationale for the need for gender-sensitive treatment modalities for prisoners. The researcher conducted an eight-week mindfulness group at a prison in the northeastern United States with 17 female prisoners. Data collection points included open-ended, semi-structured interviews at pre-group, weekly during the group, post-group, and at both 30 and 60 days post-group. The aim of this phenomenological investigation was to assess qualitative changes in female prisoners' perceptions of their own personal traumas.Electronic Thesis or Dissertatio
An examination of the relationship between supercell composite parameter and tornado occurrence in U.S. landfalling tropical cyclones.
Get PDFFor many years it has been known that tornadoes accompany most, if not all, landfalling Tropical Cyclones (TCs) in the United States. Much research has been done on the thermodynamic and kinematic environments of TCs to determine why this is, and to determine if there is a way to forecast the number of tornadoes a landfalling TC is likely to produce. Past research has indicated that many TC Tornadoes are produced by shallow supercells embedded in the rainbands of TCs. As the Storm Prediction Center has a metric, Supercell Composite Parameter (SCP),for determining potential formation of supercell thunderstorms, the question is asked whether SCP can be applied to TCs as well, and whether it can be used to discriminate between outbreak" and "non-outbreak" TCs. All U.S. landfalling TCs from 2000-2010 are studied and statistical methods are applied to determine that SCP is correlated with tornado occurrence and that SCP can be used as a discriminator between "outbreak" and "non-outbreak" TCs."Electronic Thesis or Dissertatio
Extended learning opportunities in New Hampshire: an exploration of high school students' perspectives and lived experiences
No full textThis dissertation examines the perceptions and lived experiences of high school students who have completed Extended Learning Opportunities in New Hampshire. Extended Learning Opportunities are defined as learning that occurs outside of the traditional classroom. The New Hampshire Department of Education changed its Minimum Standards for Public School Approval in 2005, and since that time, students have been eligible to earn high school credit for internships, apprenticeships, independent studies, community service, private instruction, sports, and performing groups through demonstration of mastery of academic competencies. Since very little has been written from the students' points of view regarding Extended Learning Opportunities, this hermeneutic phenomenological research study explored the perceptions and lived experiences of the students themselves. Data was collected from interviews, field notes, and artifacts and the analysis resulted in four significant themes: Relationships, Academic Freedom, Sense of Accomplishment and Connections to Life After High School. These findings shed light on the transformative and personalized benefits of Extended Learning Opportunities.Electronic Thesis or Dissertatio