Tag: Poster 77

Are Allometric Growth Patterns Consistent Throughout Development in Lower Jaw Bones of Chinook Salmon (Oncorhynchus tshawytscha)?

Presenter: Natasha Mckibben

Faculty Mentor: Charles Kimmel, Saywer Watson

Presentation Type: Poster 77

Primary Research Area: Science

Major: Human Physiology

In vertebrate species, bone morphology directly affects the function of the individual bone and the way it works within the skeletal system as a whole. Over the course of development, a variety of growth patterns are crucial in coordinating changes in bone morphology. Studying these changes in Chinook salmon, we hypothesized that the lower jaw bones, dentary and angular articular, grow allometrically, meaning that shape changes as a function of size. This study characterizes the growth pattern by quantitatively comparing bone shape of juvenile salmon using geometric morphometrics. We used two groups of juveniles at different ages, the first with an average length (fork length) of 48.5 mm and 85 mm for the second. We found that as the fish grows in length, the dentary becomes broader, while the posterior aspect of the angular articular rotates in a clockwise direction. These results show that growth between the two stages is allometric, supporting our hypothesis. We now can inquire whether the same allometric rules dictate the shape changes during other life history stages. To address this question we are examining both earlier and later time points of Chinook development. Studying such growth patterns across development can be used to evaluate how early growth patterns can impact the overall development of the individual and influence functionality, together resulting in constraints on evolution.

Search for Di-Higgs Resonance at the ATLAS Experiment

Presenter(s): Peace Kotamnives − Physics, Mathematics

Faculty Mentor(s): Eric Torrence

Poster 77

Research Area: Physical Science

Funding: Vice President for Research and Innovation (VPRI) Undergraduate Fellowship

With the question remaining whether there is only one Higgs boson or several, our research studies how a heavier Higgs boson could be found in the ATLAS data at the LHC. By the pure Standard Model phenomenon, we expect to find production of two SM Higgs bosons from the tri-linear Higgs coupling. However, the rate at which this will happen is far below what we will be able to see for many years at the LHC. As the discovered Higgs boson can decay to different pairs of particles, and the rate is expected to be proportional to the mass of the decay particle involved, the most likely decay channel is H→bb at 33%, and the second most likely channel is H→WW at 25%. Therefore, HH→bbbb channel has the highest rate of production, but HH→WWbb channel is chosen due to higher backgrounds in the four-b channel. In addition, two W bosons could decay into two quarks, one lepton and its neutrino. The performance of identifying HH→WWbb events for large heavy Higgs mass has studied specifically by using boosted object tagging. From the detector, we expect collimated jets from b quarks merging into a fat jet. By applying the relativistic kinematics theory and reducing some major backgrounds, we compare our alternative algorithms with the current algorithm in reconstructing the W→qq candidate. With the improved sensitivity, our expectation is to see a bump on top of the mass distribution indicating the new physics particle that we are searching for.

Investigating ancient flooding caused by the Chicxulub Meteorite impact

Presenter(s): Samuel Cooke

Faculty Mentor(s): Diego Melgar

Poster 77

Session: Sciences

The Cretaceous-Tertiary boundary is marked by a discrete lithologic marker and subsequent die- off of paleo species attributed to the Chicxulub meteorite impact. While many studies have investigated the global effects of the impact, which include a magnitude 10-11 earthquake, there has been limited investigation into the immediate effects triggered by the meteorite’s collision. Recently, in a paper published by DePalma et al, an on-shore surge deposit in North Dakota has been examined which contains a high-resolution chronology of the events that occurred immediately after the impact. The authors assert that in this flooding event, a tsunami is probably not the source, and instead a seismic generated seiche is responsible for the rapidly emplaced deposit. A seismic seiche (pronounced ‘saysh’) is an ephemeral standing wave that oscillates in a partially or fully enclosed basin of water in response to seismic waves. Currently there is a lack of data on seismic seiches that would serve to substantiate this claim. This research seeks to consolidate existing data on observed seiches in order to understand how earthquake and basin properties relate to seiche characteristics. To do this, published scientific papers containing observed seiche measurements in response to a seismic event were collected and characteristics such as earthquake magnitude, epicentral distance, seiche amplitude and magnitude as well as basin dimensions were analyzed. While this analysis is ongoing preliminary findings suggest a logarithmic relationship between epicentral distance and seiche amplitude.