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Gap Junction Expression and Function in Xenopus Laevis Embryos
Get PDFConnexins are intermembrane proteins that form protein complexes called connexons. These complexes bind together to form intercellular pores, called gap junctions, by binding to connexons of adjacent cells. These pores allow for passive transport of small molecules and ions involved in intercellular communication. Because gap junctions are required to transport of these ions, it is hypothesized that gap junctions are involved in developmental processes such as convergent extension during the processes of gastrulation and neurulation. In order to determine the role these genes play in development we must first determine the stages where they are expressed. To do this, cDNA (DNA reverse transcribed from RNA to only contain expressed genes) was made from developmental stages of Xenopus laevis embryos. The stages used were stage 6 (prior to activation of embryonic transcription), stage 8 (blastula), stages 10 and 12 (gastrula), stages 14, 16, 18 (neurula) and stage 20 (tailbud). This cDNA was then standardized by PCR using primers specific to ef1 alpha. This series of cDNA was then used as a template for PCR reactions of Xenopus connexin genes. The PCR reactions were then analyzed via gel electrophoresis in order to determine at what stages of development each gene is expressed. Gap junction gene alpha 3 was found to be expressed throughout neurulation and Gap junction gene alpha 7 was found to be expressed at all stages that were tested. Gap junction gene beta 1 and beta 2 were found to be expressed throughout gastrulation and neurulation. Gap junction gene alpha 2 was found to be maternally expressed as well as expressed in early gastrula, while Gap junction gene alpha 5 and alpha 4 are only expressed though early gastrulation. The next step of this project will be to use In Situ Hybridization to detect localized gene expression in embryotic tissue
Understanding Differences in Nest Site Characteristics Between Juvenile and Adult Turkeys
Get PDFWild turkeys are one of the most-actively monitored and regulated bird species in North America. Data from the northern Black Hills, South Dakota indicate that the turkey population is declining. Nest success is an important driver of turkey populations and previous nesting experience could increase the chances of selecting a nest site where at least one egg hatches. As a result, we were curious if nest site characteristics differ between adult and juvenile hens. We monitored 88 nests and recorded nest fate (success/failure) during two field seasons. We also characterized horizontal and vertical vegetation cover around each nest at the actual or projected hatch date. Of the 43 successful nests (≥1 egg hatched), 33 belonged to adult hens and 10 to juveniles. Of the 45 failed nests, 30 belonged to adults and 15 to juveniles. Successful nests of juvenile hens were in locations with 20.7% greater horizontal total cover (95% CI= 5.7 to 35.7) and 16.6% greater shrub cover (-3.2 to 36.4) than successful nests of adults. However, we did not detect differences in horizontal total or shrub cover for failed nests of juveniles and adults. We also did not detect a difference in vertical vegetation cover between nests of adults and juveniles, regardless of nest fate. Retaining sufficient vegetation cover might help provide habitat features ideal for nesting juvenile and adult hens
Characterizing Summer Roosts of Little Brown Myotis and Evaluating the Effects of Mountain Pine Beetle Disturbance
Get PDFMountain pine beetle (MPB, Dendroctonus ponderosae) outbreaks have resulted in large-scale changes in forest structure throughout the western United States. These changes can have large impacts on wildlife, but have not been studied in bats. Given that roosting sites may limit the distribution and abundance of bat populations, we aim to 1) quantify characteristics of roosts in forests during the summer and 2) evaluate how the availability of these characteristics changes with different intensities of MPB disturbance. During the summer of 2017, we mist-netted for bats in forests dominated by lodgepole pine (Pinus contorta) that exhibited varying degrees of tree mortality due to MPB. Three bat species comprised 76% of captures: hoary bat (Lasiurus cinereus, 12%), silver-haired bat (Lasionycteris noctivagans, 29%), and little brown myotis (Myotis lucifugus, 35%).Originally, we intended to tag lactating female little brown myotis to characterize maternity roosts. However, all 42 captures of little brown myotis were male. We attached radiotransmitters to 11 males and located at least 1 roost for 6 individuals (total roosts = 18). All roosts were in rock features, even though lodgepole snags were abundant and in close proximity to roosting sites. These preliminary results suggest that in lodgepole-dominated forests, male little brown myotis choose to roost in rock features over snags, regardless of the severity of MPB disturbance
Wolverine Monitoring Using Integrated Camera Trap Station in the Helena National Forest of Montana
Get PDF This study tested non-invasive wolverine monitoring methods designed to achieve cost effective collection of robust genetic and natural history data useful for the development of management practices. Historically, wolverine monitoring has used bait stations to collect hair samples, confirm presence, and estimate population sizes. Individual wolverines, their sex and reproductive status can, however, be consistently identified in the absence of DNA samples through photo analysis. Here, Integrated Camera Trap (ICT) stations combined strategically placed bait and motion-activated trail cameras with construction of wooden frameworks designed to encourage wolverines into upright, bipedal positions. Photographs of the unique ventral pelage markings that distinguish individual wolverines, as well as of sex organs and signs of reproduction were consistently captured throughout the term of the study. Hair samples for later DNA analysis were also collected from gun brushes located on the wooden frameworks. Between January and May 2016, eight ICT stations were deployed evenly across six contiguous cells in a 5 x 5 square mile grid system within the Helena National Forest near Lincoln, Montana. Six of the eight stations successfully attracted two wolverines who collectively made a total of 93 visits over the course of the study. The individuals were successfully identified as male wolverine M6 and female wolverine F7 from a library of photographs. The identity of these individuals was further confirmed through DNA analysis of hair samples collected during the study. In sum, this study supported the ability of ICT stations to collect reliable information on individual wolverine presence, sex, and reproductive status. They are cost-effective and can provide wildlife managers with valuable data
The Effect of Wildfire Smoke on Migratory Bird Species Using Nocturnal Flight Call Monitoring
Get PDFMany migratory songbirds travel at night and produce unique calls while in flight. These species-specific calls are referred to as nocturnal flight calls (NFCs) and function as a way for the birds to communicate with other individuals, echolocate, and maintain flock formation in the darker night hours. This study focused on the impact wildfire smoke density had on the frequency of NFCs recorded. The NFCs were recorded using a 21C bucket microphone from Oldbird.org, and placed at Florence-Carlton High School (FCHS), the floodplain of the MPG Ranch, and Seeley-Swan High School (SSHS). The smoke data, provided by the Montana Department of Environmental Quality (MT DEQ), were collected by monitors located in Florence and Seeley Lake. These monitors tracked the concentration of pollutant particulate matter less than 2.5 microns (PM2.5) produced by the wildfires. No previous research on the correlation between smoke and NFCs has been found. By comparing the frequency of NFCs with smoke particulate density throughout the month of August, we hope to gain a better understanding of the impact wildfire smoke has on NFC production and potentially on migration timing and patterns
Creating a Town Library Team: Collaborative Projects Between Public, School, and Academic Librarians
No full textLibrary outreach, especially at the public and academic levels, is not a new concept. In the current climate of library budget cuts, instantaneous information, and readily available nonauthoritative sources, librarians, library staff, and library directors are making it a priority to educate their communities on the benefits of and accessibility to quality library resources. Collaboration between different types of libraries is also not uncommon. Partnerships between public and school libraries assist in coordinating information literacy curricula, promoting reading programs and providing access to materials and resources. This article encourages pushing those boundaries even further out to include academic libraries, thereby expanding the scope of inter-library relationships and embracing librarianship at all com-munity levels. Each library has its own, unique perspective and clientele. Pooling information and networking at all levels of community librarianship benefits each library, its patrons, and the community as a whole
Calibration and Application of Montana Tech Shake Table Apparatus
Get PDFIn the field of geotechnical engineering, a key task when designing earth structures is preparation for seismically induced loads. To directly study the impacts of these loads upon geologic structures, models or samples of the structures are tested with a seismic shake table, an apparatus that precisely accelerates back and forth according to a specific pattern. Montana Tech recently acquired a high quality, unique shake table, and this project was the first use of it. Initially, the table was installed and a booklet outlining its use and specifications created. With the table in use, the efficacy of its ability to model acceleration-induced loads was tested by subjecting a number of rock joint samples to seismic loads of varying intensity. The critical acceleration value, the value at which static friction is overcome, will then be identified and compared to other methods of frictional analysis such as tilt tests. The critical acceleration can be implemented into a calculation to find static coefficient of friction, as can a friction angle acquired from tilt tests of the same samples, allowing for direct comparison. Furthermore, samples subjected to sinusoidal wave patterns can also be compared to dynamically loaded discrete element models for further verification. This project itself is preliminary, buy with this relationship proven, the application of the shake table can proliferate to more complex simulations such as liquefaction, structural fundamental frequencies, and complex earthquake time histories
Does Aquaporin 3B Affect the Number and Characteristics of Calcium Waves in the Neural Plate of Xenopus Laevis Embryos?
Get PDFEarly in the development of the nervous system, vertebrate embryos undergo neural tube closure. This is a process where the cells in the dorsal part of an embryo, the neural plate,constrict on their outward facing side (apical constriction) to form a tube. The Merzdorf lab has found that inhibiting expression of the protein Aquaporin 3b (Aqp3b) in Xenopus laevis embryos prevents neural tube closure from happening. Given that aqp3b is only expressed in a well-defined line along the outer edge of each side of the neural plate, this action at a distance suggests some form of intercellular communication. In fact, calcium waves are required for neural tube closure. My hypothesis is that Aqp3b triggers the calcium waves that cause neural plate cells to apically constrict. To address this question, the number and characteristics of calcium waves will be compared between normal embryos and embryos that have been inhibited from expressing Aqp3b. My specific hypothesis is that the neural plate in embryos with inhibited aquaporin expression will have fewer calcium waves with different characteristics. Working towards the goal of answering this question I have developed and finetuned a method for injecting the embryos with a calcium indicator and imaging them. I have begun collecting time lapse images of calcium activity during neural tube closure and am designing methods for analyzing the time lapses I capture. This research is significant because, while calcium transients are known to be necessary to neural tube closure, no triggers of these calcium waves are known
Sampling the Grains: Pollen Samples from Hummingbirds
Get PDFHummingbirds transmit pollen both actively and passively while feeding or moving through the landscape. They play a largely undocumented role in plant pollination on their breeding grounds. Many hummingbirds also migrate thousands of miles, potentially transporting pollen greater distances than other pollinators. To investigate the role of hummingbirds in both short- and long-distance pollen transfer, we collected pollen samples from the heads and bills of hummingbirds during migration and throughout the breeding season. We identified the pollen from 44 hummingbirds captured during the 2016 and 2017 field season in western Montana. We also solicited and analyzed 9 samples from southwestern Idaho. Pollen analysis revealed 18 different genera of pollen on sampled hummingbirds, including genera (e.g., Pinus, Larix) that passively broadcast pollen. We detected some pollen from plant species not locally available, suggesting that hummingbirds do transfer pollen long distances, and may serve as vectors for plant genetic diversity. Pollen grains differed in their anatomy and potential for adhesion to hummingbird feathers and bills, suggesting that some pollen is better suited for long-distance dispersal. We plan to continue collecting pollen samples from ours and other sites in the future. We also hope to perform experiments that investigate the role pollen morphology may play in adhesion longevity
Grizzly Bear and Human Use at Moth Sites in the Greater Yellowstone Ecosystem
Get PDFIn the greater Yellowstone ecosystem (GYE), alpine aggregations of army cutworm moths (Euxoa auxiliaris) are an important food source for grizzly bears (Ursus arctos horribilis). The number of grizzly bears utilizing this food source has increased since initial documentation in 1986 in the Shoshone National Forest, Wyoming. Dozens of bears congregate and feed on moths offering a unique viewing opportunity for bear-enthusiasts, professional media, and hikers. Currently, there is a limited understanding of how bears use these areas and no information on human use. The proximity of grizzly bears and humans poses a management concern for grizzly bears and human safety. Our objectives are to quantify grizzly bear and human use patterns and to identify areas of bear-human interactions. Our methods include occupancy and written surveys, GPS tracking unit deployment, and GIS analysis. Preliminary results from our first year of bear observations (n=220) showed 48% of bears foraging on moths, 20% foraging on vegetation, and 23% travelling. We recorded 5 groups and 26 groups of human use at two locations. We documented 18 bearhuman interactions, all on high-use travel routes common to bears and humans. Despite low human use all interactions between bears and humans resulted in bear avoidance of humans. At present, bear-human interactions appear to be very low but if human use increases, interactions will increase due to lack of alternate travel routes