Physical Sciences and Mathematics Commons^™

Vertebrate Diversity In The La Amistad International Park Buffer Zone, Guadalupe, Chiriqui, Panamá, Mina Olson

Independent Study Project (ISP) Collection

Forest fragmentation and increasing agricultural land use are posing threats to the diversity of vertebrates in Panama and across the Mesoamerican Biological Corridor. Protected areas are crucial for providing connectivity and maintaining vertebrate populations. For endemic species with small native ranges, these protected areas are critical for their survival due to sensitivity of habitat change. Higher species diversity and occupancy has been reported for both birds and mammals in protected and forested areas. This pilot survey of vertebrate species was conducted to determine which species live in a primary forest within the buffer zone of La Amistad International Park near …

Deep Reinforcement Learning For Dynamic Algorithm Selection: A Proof-Of-Principle Study On Differential Evolution, Hongshu Guo, Yining Ma, Zeyuan Ma, Jiacheng Chen, Xinglin Zhang, Zhiguang Cao, Jun Zhang, Yue-Jiao Gong

Research Collection School Of Computing and Information Systems

Evolutionary algorithms, such as differential evolution, excel in solving real-parameter optimization challenges. However, the effectiveness of a single algorithm varies across different problem instances, necessitating considerable efforts in algorithm selection or configuration. This article aims to address the limitation by leveraging the complementary strengths of a group of algorithms and dynamically scheduling them throughout the optimization progress for specific problems. We propose a deep reinforcement learning-based dynamic algorithm selection framework to accomplish this task. Our approach models the dynamic algorithm selection a Markov decision process, training an agent in a policy gradient manner to select the most suitable algorithm according …

Transcriptional Dynamics During Rhodococcus Erythropolis Infection With Phage Wc1, Dana Willner, Sudip Paudel, Andrew D. Halleran, Grace E. Solini, Veronica Gray, Margaret Saha

Arts & Sciences Articles

Background

Belonging to the Actinobacteria phylum, members of the Rhodococcus genus thrive in soil, water, and even intracellularly. While most species are non-pathogenic, several cause respiratory disease in animals and, more rarely, in humans. Over 100 phages that infect Rhodococcus species have been isolated but despite their importance for Rhodococcus ecology and biotechnology applications, little is known regarding the molecular genetic interactions between phage and host during infection. To address this need, we report RNA-Seq analysis of a novel Rhodococcus erythopolis phage, WC1, analyzing both the phage and host transcriptome at various stages throughout the infection process.

Results

By five …

Sovereign Seeds: Analyzing The Sustainability Of Peasant Seeds In The Context Of Climate Change And Rural Exodus In Tunisia, Alice Carlson

Independent Study Project (ISP) Collection

How sustainable are peasant seeds? I answer this question on the basis of three elements: environment, economy, and social justice. Using interviews with farmers from various regions of Tunisia, an interview with an expert on climate change and migration, and an interview with a civil society organization working to promote sustainable agriculture, I found that peasant seeds are a sustainable solution for a suffering agricultural sector. Depleted water sources and drought are bringing to light the problems with water-intensive hybrid seeds, and farmers are losing money. As young men increasingly leave the agricultural sector, women are left behind, finding themselves …

A Study Of Anthropogenic Impacts On Echinoderms In The Jambiani Intertidal Area, Zanzibar, Amaury O. Halley

Independent Study Project (ISP) Collection

The coastal region of Jambiani, Unguja, hosts a rich diversity of marine life within its extensive intertidal zones. Despite its ecological significance, this area is increasingly exposed to anthropogenic disturbances due to increased human activities. This study examines the impacts of these disturbances on the biodiversity, zonation, and species abundance of echinoderms in the intertidal habitats of Jambiani. Through a comprehensive field study involving fifteen transects and detailed substrate analysis, the project evaluated the distribution and abundance of echinoderm species and assessed the influence of human activities such as seaweed farming, anchor damage, and beach trampling on these communities. The …

Impacts Of Gas Flaring On Soil Quality In The Ecuadorian Amazon: Measuring Gas Flare Effects On Soils At Comparative Distances In Loma Del Tigre, Orellana, Francesca Lopresti

Independent Study Project (ISP) Collection

Gas flaring, the process of burning off the natural gas excreted during petroleum extraction, has recently been the source of public outcry, citing degraded public and environmental health caused by constant flaring near populated centers. While extensive research has been done on the environmental and health impacts of gas flaring, regionally specific research to the Ecuadorian Amazon is lacking. It is crucial that updated research in this region is produced to inform regulations that have the potential to minimize the physical, environmental, and economic impact of the petroleum industry on nearby, under-resourced, and marginalized communities. While air quality surrounding gas …

Género Y Resiliencia En La Amazonía Peruana: Las Experiencias Y Respuestas De Agricultoras Indígenas Ante El Cambio Climático, Zoe Klausner

Independent Study Project (ISP) Collection

El cambio climático antropogénico está redefiniendo rápidamente las relaciones humano-ambientales, especialmente en la Amazonía peruana, donde más de 66 comunidades indígenas enfrentan mayores sequías y temperaturas, afectando profundamente sus medios de vida. Crucialmente, desde la visión ecofeminista central a esta investigación se subraya que las mujeres indígenas experimentan los impactos del cambio climático más severamente y son a menudo los líderes en el fomento de la resiliencia ambiental. Esta investigación explora cómo las agricultoras indígenas de la Amazonía peruana viven el cambio climático y sus estrategias de adaptación y resiliencia. El trabajo de campo se realizó en la comunidad Ese'Eja …

10 Meters To Disaster: The Challenges Of Premature Application Of Circular Economy Strategies In Jakarta’S Waste Management Structure, Almira Bowo

Independent Study Project (ISP) Collection

Jakarta's complex issue of waste management encompasses a multitude of challenges that include inefficiencies in infrastructure, a lack of public awareness of the consequences of an inadequate waste system, socioeconomic disparities, and a deficiency in intersectoral collaboration. The urgency for holistic and sustainable solutions that prioritize proactive waste collection is underscored by the complexities of these dynamics. This field study paper argues that the attention that is being drawn towards trending waste management innovations, which are reactive strategies, could bring the waste crisis in Jakarta to an even more critical state. The sections will critically examine current waste management efforts …

Anuran Diversity And Abundance Across Two Sites With Varying Levels Of Light Pollution In El Valle De Antón, Coclé, Panamá, Jackson Dray

Independent Study Project (ISP) Collection

The impact of artificial light at night (ALAN) on anuran populations has been a subject of growing concern in ecological research. Anurans are particularly susceptible to the impacts of artificial light due to their nocturnal nature and an extensive exposure throughout various stages of life histories. Exposure to artificial light has been shown to impact the larval development and reproductive behavior of anurans. The impacts on anurans juvenile populations suggest a relationship between light pollution and anuran abundance. This study aimed to investigate the hypothesis that ALAN negatively affects the abundance and diversity of anurans. Field surveys were conducted in …

From Collaboration To Continuity: Exploring Stakeholder Engagement For Sustainable Global Health Partnerships, Annabelle Falconer

Independent Study Project (ISP) Collection

Global health partnerships have been identified as crucial to achieving the Sustainable Development Goals and targets related to health and wellbeing. Specifically, the Global Fund, UNAIDS Joint Programme, and the World Food Programme are examples of some of the relevant partners currently engaged in this work, filling roles in global health financing, governance, and delivery. Current literature has identified that the effective engagement of stakeholders in partnerships can be crucial in effective project implementation and that global health partnerships during the era of the Millennium Development Goals did impact health outcomes. This research aims to investigate the current strategies for …

Assessing The Impact Of Climate Change On Harbor Seals: Haul-Out Patterns In Iceland Using Cmip6 Projections, Colin Lau

Independent Study Project (ISP) Collection

Harbor seals (Phoca vitulina) are known to exhibit a preference for specific environmental and weather conditions when hauling out, particularly during the pupping and molting cycles during summer. Climate change is projected to have a significant impact on the haul-out patterns and site conditions of harbor seals in Iceland, which could further diminish their dwindling population. A comprehensive literature review was conducted to identify and discuss the environmental variables that can affect haul-out probability. Among them, surface wind speed and air temperature are reported to have the biggest influence on harbor seal haul-out numbers between May and August. Climate projections …

The Role Of Geomorphological Context In Vegetative Succession Within The Breiðamerkurjökull Glacial Foreland, Lucas Nerbonne

Independent Study Project (ISP) Collection

As glaciers retreat worldwide at an accelerating pace, understanding primary succession in these newly exposed landscapes becomes increasingly critical. This study examines the initial vegetative colonization patterns in glacial forelands, focusing on the influence of geomorphological formations of resulting plant communities. By analyzing vegetative communities in glaciofluvial and push moraine deposits, this study highlights how the more varied, channelized morphologies of fluvial deposits create potential microclimates better conducive to heterogenous plant colonization than the homogenous terrain of the nearby push moraine. Vegetative coverage, sediment size, and species abundance was collected at 480 sites across 6 different historical glacial extents across …

Investigating Ocean Carbonate System Changes Across Latitudes In The North Atlantic Basin With A Time-Series Mooring System, Anna Trujillo

Independent Study Project (ISP) Collection

The world ocean, specifically the Arctic, serves as one of the greatest mitigators for anthropogenic carbon dioxide release, making the study of high latitude ocean carbonate chemistry an increasingly important topic. While much work has been done concerning the science of acidification and future model projections, analyzing data to detect decadal anthropogenic trends and effects is also highly important. Aiming to add to this data pool, this study investigated the ocean carbonate system at three North Atlantic mooring locations at polar, subtropical, and tropical latitudes from 2013 - 2021. Time series datasets of the pH and pCO₂ of surface water …

Lisbon’S Electric Vehicle (Ev) Fleet: A Cost-Benefit Analysis Of A Mass Adoption Of Evs In Lisbon By 2050, Maya Estrera

Independent Study Project (ISP) Collection

As the impacts of climate change increase, the EU and its member countries are attempting to achieve carbon neutrality by 2050. The adoption of electric vehicles is proving to be a promising solution to achieve this goal, and specifically, reductions in the transport sector emissions. This study analyzes the potential costs and benefits resulting from a mass adoption of electric vehicles in Lisbon by 2050. Through a cost-benefit analysis, this study aims to quantify the major costs and benefits associated with electric vehicles. The results display the potential monetary benefits of a city-wide shift to electric vehicles in addition to …

Mushroom Composition Across An Elevational Gradient During The 2024 Wet Season In Mazumbai Forest Reserve, Tanzania, Christopher Brady

Independent Study Project (ISP) Collection

Mushrooms are key bioindicators that contribute greatly to ecological health, and their diversity is indicative of a healthy ecosystem. However, even with the vital role they play in ecological health, there are few studies which measure the diversity of mushrooms in Mazumbai Forest Reserve (MFR), Tanzania, Africa, and none which focus on diversity along the elevational gradient within the reserve (1300-1900m). This study measures the diversity and equitability of mushrooms growing in six elevational zones within MFR during the rainy season of 2024. A species checklist of mushrooms growing in MFR during the 2024 rainy season was created, tracking the …

Solar Energy Adoption In Unguja, Tanzania: Influence Of Awareness, Socioeconomics, And Technology Knowledge, Maxime Warnery

Independent Study Project (ISP) Collection

This study looked into the effect of information dissemination on the willingness to adopt solar energy on Unguja Island in the Zanzibar Archipelago. Utilizing an information provision survey, I collected data on demographic factors, personal beliefs, and attitudes towards solar energy. The research focused on determining how information provision affects public perceptions and the likelihood of adopting solar technologies. The findings revealed a significant positive correlation between detailed and contextually relevant information and increased acceptance of solar energy solutions. The enhanced intervention was particularly effective in changing beliefs about solar energy's reliability and economic benefits, addressing critical local issues such …

Applications Of Survival Estimation Under Stochastic Order To Cancer: The Three Sample Problem, Sage Vantine

Honors Program Theses and Research Projects

Stochastic ordering of probability distributions holds various practical applications. However, in real-world scenarios, the empirical survival functions extracted from actual data often fail to meet the requirements of stochastic ordering. Consequently, we must devise methods to estimate these distribution curves in order to satisfy the constraint. In practical applications, such as the investigation of the time of death or the progression of diseases like cancer, we frequently observe that patients with one condition are expected to exhibit a higher likelihood of survival at all time points compared to those with a different condition. Nevertheless, when we attempt to fit a …

Urban Flooding: Legal Tools To Address A Growing Crisis, Michael B. Gerrard

Faculty Scholarship

While sea level rise has long received a great deal of attention, another impact of climate change is now getting greater notice — increases in extreme precipitation. As the atmosphere warms, it can hold more moisture; for every increase of one degree Celsius, seven percent more water vapor is carried in the air. When that moisture is quickly released as intense rainstorms, stormwater systems can be overwhelmed, and cities can suffer devastating floods.

The frequency and intensity of heavy precipitation events have increased since the 1950s over most of the world's land areas. One 2023 study — generally consistent with …

Automated Glacier Classification In High Mountain Asia Using Machine Learning And A Random Forest Classifier, Victoria Elizabeth Halvorson

Dartmouth College Master’s Theses

High Mountain Asia (HMA) is home to the largest mass of glaciers and ice outside the north and south polar regions. HMA glaciers are projected to experience accelerated mass loss from higher greenhouse gas emissions through the end of the century. Many studies of glacier mass balance and mass loss in HMA obtain glacier area from the Randolph Glacier Inventory (RGI). However, the RGI is designed to show glacier area across the world that is accurate to the year 2000 and, as a result, is not an accurate representation of the current state of glacier area in HMA. Additionally, glacier …

Multi-Aspect Rule-Based Ai: Methods, Taxonomy, Challenges And Directions Towards Automation, Intelligence And Transparent Cybersecurity Modeling For Critical Infrastructures, Iqbal H. Sarker, Helge Janicke, Mohamed A. Ferrag, Alsharif Abuadbba

Research outputs 2022 to 2026

Critical infrastructure (CI) typically refers to the essential physical and virtual systems, assets, and services that are vital for the functioning and well-being of a society, economy, or nation. However, the rapid proliferation and dynamism of today's cyber threats in digital environments may disrupt CI functionalities, which would have a debilitating impact on public safety, economic stability, and national security. This has led to much interest in effective cybersecurity solutions regarding automation and intelligent decision-making, where AI-based modeling is potentially significant. In this paper, we take into account “Rule-based AI” rather than other black-box solutions since model transparency, i.e., human …

Matrix Profile Data Mining For Bgp Anomaly Detection, Ben A. Scott, Michael N. Johnstone, Patryk Szewczyk, Steven Richardson

Research outputs 2022 to 2026

The Border Gateway Protocol (BGP), acting as the communication protocol that binds the Internet, remains vulnerable despite Internet security advancements. This is not surprising, as the Internet was not designed to be resilient to cyber-attacks, therefore the detection of anomalous activity was not of prime importance to the Internet creators. Detection of BGP anomalies can potentially provide network operators with an early warning system to focus on protecting networks, systems, and infrastructure from significant impact, improve security posture and resilience, while ultimately contributing to a secure global Internet environment. In this paper, we present a novel technique for the detection …

Nonstationary Recharge Responses To A Drying Climate In The Gnangara Groundwater System, Western Australia, Simone Gelsinari, Sarah Bourke, James Mccallum, Don Mcfarlane, Joel Hall, Richard Silberstein, Sally Thompson

Research outputs 2022 to 2026

The response of groundwater recharge to climate change needs to be understood to enable sustainable management of groundwater systems today and in the future, yet observations of recharge over long-enough time periods to reveal responses to climate trends are scarce. Here we present a meta-analysis of 60 years of recharge studies over the Gnangara Groundwater System of South-West Western Australia, covering a period of sustained drying consistent with climate change projections. The recharge process in the area is defined by a wet winter during which rain saturates a deep, highly permeable soil profile with very low water storage capacity. Measurements …

Discovering Significant Topics From Legal Decisions With Selective Inference, Jerrold Tsin Howe Soh

Research Collection Yong Pung How School Of Law

We propose and evaluate an automated pipeline for discovering significant topics from legal decision texts by passing features synthesized with topic models through penalized regressions and post-selection significance tests. The method identifies case topics significantly correlated with outcomes, topic-word distributions which can be manually interpreted to gain insights about significant topics, and case-topic weights which can be used to identify representative cases for each topic. We demonstrate the method on a new dataset of domain name disputes and a canonical dataset of European Court of Human Rights violation cases. Topic models based on latent semantic analysis as well as language …

Dynamic Soil-Structure Response And Failure Of Wood Utility Poles Under Hurricane-Force Wind And Non-Linear Cable Loads, Ramani Ayakannu

Civil & Environmental Engineering Theses & Dissertations

This dissertation presents the outcome of a study of the dynamic soil-structure interaction response of tapered wood utility poles embedded in various foundation soils subject to quasi-static and dynamic wind loads. The study includes the effects of nonlinear soil behavior with varying quantities of moisture and nonlinear cable tension loads on a class H1 wood pole. The natural frequency response of the pole is determined using a finite element formulation. The dynamic response in the presence of wind-induced forcing function is studied using a SAP2000 finite element scheme with wind speeds up to 220 mph. The natural frequency of the …

Impact Of Climate Change On Carbon And Nitrogen Balance In Zostera Marina L. (Eelgrass), Malee Jinuntuya

OES Theses and Dissertations

Seagrasses face vulnerability to both global stressors like Ocean Acidification (OA) and climate warming compounded by local stressors such as eutrophication that reduces light availability, leading to a complex dynamic of positive and negative effect on their growth and survival. Increased dissolved aqueous CO₂ (CO_2(aq)) benefits seagrasses by enhancing photosynthetic and growth rates, but it may increase nutrient demand, potentially depleting nutrient supply, especially in oligotrophic environments.

In this study, the long-term impact of CO₂ on Zostera marina L. (eelgrass) were investigated across a gradient of CO_2(aq) concentrations (55 – 2200 µM CO_{2(aq)) …}

Longitudinal Solid Polarized Target For Clas12 And Study Of Spin Structure Of Nucleons, Pushpa Pandey

Physics Theses & Dissertations

A suite of experiments measuring target-spin observables in electron-nucleon scattering (dubbed Run Group C) was conducted at Jefferson Lab’s Hall B in Newport News, VA with a new polarized nuclear target known as ‘APOLLO’ (Ammonia Polarized Longitudinally). This innovative target is engineered to seamlessly integrate with the advanced 12 GeV CEBAF (Continuous Electron Beam Accelerator Facility) accelerator and the Hall B CLAS12 (12 GeV CEBAF Large Acceptance Spectrometer) detector array. The ‘APOLLO’ target harnesses the power of Dynamic Nuclear Polarization (DNP) to achieve longitudinal polarization of solid ammonia, thereby creating a net polarization in both protons (NH₃) and …

Study Of Deep Learning Models To Classify Nasa’S Kepler Light Curves, Heena Minnich

Computer Science Theses & Dissertations

The search for exoplanets has been an ongoing effort since the first discoveries of planets beyond our solar system in the 1990s. Finding a potentially habitable planet outside our solar system could provide key insights on life elsewhere in the universe. NASA Missions such as the Kepler, launched in 2009 and completed in 2018, have provided a massive amount of data in this goal by using the transit method to discover repetitive and periodic dips in visible light around a star. The transit method has been used to measure flux, the brightness of a star over time. These flux time …

Application Of The Fokker-Planck Equation For Quantifying Initial Condition Uncertainty Of Reversible Dynamic Systems, Troy S. Newhart

Mechanical & Aerospace Engineering Theses & Dissertations

Characterizing the behavior of dynamic systems requires the inclusion of initial conditions to propagate behavior forward in time. More realistic representations of system behavior quantify uncertainty about the initial conditions to assess sensitivity, reliability, and other stochastic response parameters. In many engineering applications, the uncertain initial conditions may be unknown given a desired response. This research applies the Fokker-Planck equation to reversible dynamic systems of select multi-dimensional nonlinear differential equations as a means for predicting the uncertainty about initial conditions. An alternating directions implicit numerical scheme is used to numerically solve the Fokker-Planck equation for both forward and reversed equations …

Scaled And Graduated Learning In Deep Relu Networks And Reconstructing Depp Inelastic Scattering Kinematics, Abdullah Ayar Farhat

Mathematics & Statistics Theses & Dissertations

To address computational challenges in learning deep neural networks, properties of deep RELU networks were studied to develop a multi-scale learning model. The multi-scale model was compared to the multi-grade learning models. Unlike the deep neural network learned from the standard single-scale, single-grade model, the multi-scale neural networks use low scale information from all hidden layers, and thusly provide a robust approximation method that requires fewer parameters, lower computational time, and is resistant to noise. It is shown that the multiscale method is not subject to issues arising from the vanishing gradient problem. This allows very deep multi-scale networks to …

Computational Modeling And Analysis Of Facial Expressions And Gaze For Discovery Of Candidate Behavioral Biomarkers For Children And Young Adults With Autism Spectrum Disorder, Megan Anita Witherow

Electrical & Computer Engineering Theses & Dissertations

Facial expression production and perception in autism spectrum disorder (ASD) suggest the potential presence of behavioral biomarkers that may stratify individuals on the spectrum into prognostic or treatment subgroups. High-speed internet and the ease of technology have enabled remote, scalable, affordable, and timely access to medical care, such as measurements of ASDrelated behaviors in familiar environments to complement clinical observation. Machine and deep learning (DL)-based analysis of video tracking (VT) of expression production and eye tracking (ET) of expression perception may aid stratification biomarker discovery for children and young adults with ASD. However, there are open challenges in 1) facial …