Fearless Friday: Kirsten Crear

Even in her last semester here at Gettysburg, Kirsten Crear ’14 is fearlessly working to make changes for the future of the campus community. This semester, Kirsten introduced a STEMinists club on campus that will give female students who are STEM (an acronym for Science-Technology-Engineering-Mathematics) majors the opportunity to come together and create a community, share and discuss the difficulties they face as women in their fields of study, and support and mentor each other as they prepare to enter their fields. Kirsten is passionate, driven, and determined, taking the initiative to bring this group of women together on campus so that together they can begin to challenge the norms and stereotypes about women in their fields, creating change for the future. [excerpt

Assessing The Variability In Distribution Of Four Shark Species Within The Mississippi Sound

Global declines in shark populations have been observed, including several species indigenous to the northwest Atlantic Ocean and the Gulf of Mexico (GOM). Attributing to these declines is a lack of abundance and distribution data of early life stages, particularly within essential habitats such as nursery grounds. Previous research has defined the Mississippi Sound as a multispecies shark nursery, therefore determining how abundance and distribution patterns change will aid in verifying where these species are throughout the year within this shark nursery. Thus, the objectives of the current study were to describe the variability in distributions of four shark species in the Mississippi Sound. From March 2009 to October 2011, 1,309 sharks including, 737 Atlantic sharpnose, Rhizoprionodon terraenovae, 332 finetooth, Carcharhinus isodon, 151 blacktip, Carcharhinus limbatus, and 89 bonnethead, Sphyrna tiburo, sharks were collected within the Mississippi Sound. Male Atlantic sharpnose were present in the sound throughout all life stages where as females left the sound once maturity was reached. Immature finetooth and blacktip utilized the Mississippi Sound as a nursery and left before maturity was reached. Low abundances of bonnethead suggested that this area is not as important for this species. All species preferred the Central and East Areas within the Mississippi Sound in 2010 and 2011, demonstrating the possible effect of environmental parameters such as temperature, salinity, and dissolved oxygen on shark distribution. Relatively higher abundances were observed in the summer compared to spring and fall for all species of sharks. This study confirms that the Mississippi Sound is an important nursery ground for Atlantic sharpnose, finetooth, and blacktip sharks

Adaptation of Dry Collection Methods to Quantify Extraction Efficiency of Staphylococcus aureus from Environmental Samples

The Gram-positive bacterium, Staphylococcus aureus can survive in indoor environments in the community, such as schools and homes, contributing to public health concerns related to human exposure and transmission. While convenient methods that do not require refrigeration or surface wetting have been described for identification of environmental S. aureus, these methods currently only provide a positive or negative result. Therefore, the goal of this project was to adapt and validate a dry collection method to provide quantification of S. aureus from indoor environmental samples comparing culture-based and culture-independent approaches, and then apply this method to environmental surface samples from local schools. For this project, S. aureus ATCC43300 was inoculated onto autoclaved Swiffer cloths. Then, S. aureus colonies were extracted from the cloths in 100ml of 1x solution phosphate buffered saline (PBS), the PBS extract was concentrated by vacuum filtration, and colony forming units (CFUs) enumerated on CHROMagar staph agar. S. aureus was successfully enumerated from experimentally-inoculated cloths. The findings from this work demonstrate that S. aureus can be recovered and quantified from dry cloth surface samples. This work also displays that the culture independent method was optimum for extraction efficiency and ease of use. This work highlights the importance of methodological development for S. aureus exposure assessment from indoor community environments

Adaptation of Dry Collection Methods to Quantify Extraction Efficiency of Staphylococcus aureus from Environmental Samples Johns Hopkins Bloomberg School of Public Health

The Gram-positive bacterium, Staphylococcus aureus can survive in indoor environments in the community, such as schools and homes, contributing to public health concerns related to human exposure and transmission. While convenient methods that do not require refrigeration or surface wetting have been described for identification of environmental S. aureus, these methods currently only provide a positive or negative result. Therefore, the goal of this project was to adapt and validate a dry collection method to provide quantification of S. aureus from indoor environmental samples comparing culture-based and culture-independent approaches, and then apply this method to environmental surface samples from local schools. For this project, S. aureus ATCC43300 was inoculated onto autoclaved Swiffer cloths. Then, S. aureus colonies were extracted from the cloths in 100ml of 1x solution phosphate buffered saline (PBS). The PBS extract was concentrated by vacuum filtration, and colony forming units (CFUs) enumerated on CHROMagar staph agar. S. aureus was successfully enumerated from experimentally-inoculated cloths. The findings from this work demonstrate that S. aureus can be recovered and quantified from dry cloth surface samples. This work also displays that the culture independent method was optimum for extraction efficiency and ease of use. This work highlights the importance of methodological development for S. aureus exposure assessment from indoor community environments

A Case Study Exploring Organizational Development and Performance Management in the Operational Infrastructure of a Professional Working Organization, Using Academic Constructs

Curriculum, as a concept, has been historically associated with traditional schooling, but the reality is that its application extends to many arenas beyond academia. Through the case study lens, this dissertation utilized the ideologies of curricular theorists John Dewey, John Franklin Bobbitt, and Ralph Tyler to explore how intended, enacted, and assessed curricula phases can integrate into a professional working organization’s comprehensive functionality and materialize into the planning and implementation of its operational infrastructure. Following content analysis of a selected institution’s operational system, using closed codes, a descriptive comprehensive curriculum was designed to address the research purpose of understanding employee performance and organizational outcomes. Findings indicated that curricular phases are inherently embedded into the organizational development and performance management of nonacademic spaces; moreover, the framework of an organization’s operational infrastructure consists largely of curriculum elements. The primary research implication invokes being able to manage the efficiency and effectiveness levels of (a) personnel unit performance and (b) the workplace environment, through curriculum analysis and prescription

Predicting the Impacts of Climate Change on the Sandbar Shark and Cobia

A changing climate has been identified as a major driver of changes in marine species’ distribution, phenology, and habitat selection in recent decades and is expected to continue to influence these traits. These changes are not only happening in our oceans, but within coastal habitats as well, where waters are susceptible to sudden changes in temperature and oxygen levels are influenced by nutrient inputs. These changes which will likely impact fish species that utilize these areas as nurseries, spawning habitat, or foraging grounds. In this dissertation I consider climate impacts on two important predators, the sandbar shark (Carcharhinus plumbeus) and cobia (Rachycentron canadum), both of which rely on coastal habitats like Chesapeake Bay for their survival. I used a series of physiological, survey, tagging, and modeling studies to estimate the current and future impacts of climate change on these two species. Sandbar sharks are unable to handle temperatures as warm as 32°C physiology, but in the wild prefer temperatures between 22-26°C. As a result, I estimate bottom habitat losses in Chesapeake Bay by end-of-century for juvenile sandbar sharks. Although they are relatively intolerant of hypoxia (critical oxygen concentration = 3.5 mg l-1), juvenile sandbar shark appear to prefer areas on the fringes of hypoxic zones to avoid larger sharks and find more abundant prey. Therefore, the continued reduction in oxygen levels throughout the entire water column actually improves juvenile sandbar shark suitable habitat. Being a bottom dwelling species, sandbar shark in Chesapeake Bay may be forced to remain in non-preferred bottom habitat, move up in the water column, or shift to shallower habitats. Cobia are tolerant of high temperatures (32°C) and low oxygen (1.7-2.4 mg/l) which should allow them to withstand the detrimental effects of climate change in Chesapeake Bay, at least through mid-century. Hypoxia and elevated temperatures reduce survival of cobia that are exercised to exhaustion. Although the physiology experiments and habitat models suggest cobia will withstand climate change through mid-century, declines in their suitable habitat in Chesapeake Bay are expected by end-of-century. I project arrival time to occur earlier and departure time to occur later when temperatures are warmer and that by mid- and end-of-century cobia may spend on average up to 30 and 65 more days, respectively, in Chesapeake Bay. As conditions worsen in more southern estuaries, cobia may shift spawning habitat in estuaries and bays further north, such as Delaware Bay, New York/New Jersey Bight, and Long Island Sound, where conditions are more thermally suitable. Over the next 60-80 years, suitable cobia habitat is projected to shift northward from spring to fall and to decrease over the U.S. continental shelf. As cobia shift into new areas, the development of regulations in more northern states will become necessary to promote a sustainable cobia fishery. As species shift their distributions as a result of climate change, it is imperative that we understand why and how these shifts are occurring so that both managers and fishers can ensure important resources continue to be fished sustainably

Visibly Invisible: Uncovering Identity for African American Women at an Academically Selective University

Using intersectionality as the theoretical framework, this study examined the identity development of African American women attending an academically selective university. Much of the extant literature on African American college women was either not identity focused or did not speak to the experiences of those students situated in these highly competitive academic environments. A qualitative research approach and case study analysis was utilized for this study. This included the use of photographs and photo-elicitation interviewing to actively engage the study’s participants in the process of sharing their identity development and to place their voice and how they make meaning of their complex identities as primary. Examining both their pre-college and in-college experiences, this study looked closely at the impact of family, peer groups, society, internal messages, and the academically selective university setting on the participants’ identity development. While the women in the study enter college viewing identity as largely fixed, the collegiate context played an important role in facilitating their identity evolution. This study outlined the growth process as these participants shifted their understanding of identity from fixed to fluid or from invisible to visible. Implications for this research include the need for colleges and universities to better address the holistic needs of African American female students, especially at their identity intersections. Additional areas for research include reconceptualizing college student identity development to incorporate more holistic, intersectional elements as a means to supporting a student’s development more comprehensively