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Going North: Inferring Testate Amoeba Habitat Shifts in Response to Climate Change with Ecological Niche Modeling
No full textArcellinida are an ancient clade of single-celled eukaryotes distinguished by their tests (shells). They occupy a variety of habitats, including freshwater and other moist environments like leaf litter and soil. The question of how microbes like Arcellinida are dispersed has long troubled microbiologists. Arcellinida are seen as cosmopolitan morphospecies, but studies have shown the distribution of cryptic species within these lineages may be limited by environmental factors or geographical regions. Understanding Arcellinida distribution patterns is important to interpret their evolutionary history and possible ecological shifts that influenced speciation events. Previous studies often focused on a few sites over a small geographic range, making it difficult to assess broad environmental drivers that govern restricted habitat distributions. Here, we use MaxEnt, a machine learning software that uses presence-absence data to assess Arcellinda through time, space, and geography, to predict preferred ecological niches across North America. We train this model by introducing location data collected from a literature review of sites where Arcellinida have been recorded and environmental layers collected from the global climate data site Worldclim. Based on the abiotic characteristics of the literature observation sites, MaxEnt predicts other habitats across North America where Arcellinida are likely to be found. We then use sets of future data taken from the Coupled Model Intercomparison Project, which predict what environmental conditions will be in the years 2050 and 2070, to predict how Arcellinida habitats will shift as a result of climate change. Preliminary results suggest that current habitats for Arcellinida are concentrated in Northern Mexico, along the West Coast of Canada, and the south of the United States. These niches are predicted to shift increasingly Northwest over time, with a narrowing latitudinal range. This work will help us better understand the most influential environmental conditions for Arcellinida distribution and lays the groundwork for future assessments of paleoclimate. By increasing our understanding of the geographic and evolutionary history of the Arcellinida clade, this project will contribute to our understanding of a major microbial community, and allow us to understand how the environment has and will shape diversity in the future
What Makes a Requirement?: Towards Distinguishing Software Requirements from Generic Text
No full textRequirements engineering is the practice of identifying and managing requirements during the software engineering process. These requirements are identified and stored in natural language documents called Software Requirements Specification (SRS) documents, which also contain other information about the software project. Requirements are written in a variety of requirements notations, for example natural language and EARS. As SRS documents grow to be very long or become unstructured, it becomes harder for humans to identify requirements within them. As a result, it would be ideal to have the ability to extract only the requirements out of SRS documents written in natural language. To distinguish requirements among natural language, Natural Language Processing (NLP) techniques must be used. This thesis explores the research question of identifying requirements among natural language and conducts a literature survey of existing relevant techniques. We build off existing state of the art and present our initial system, ReqSpotter, that identifies sentence long requirements among natural language
Temporal Dynamics of Faculty Hiring in Mathematics
Get PDFUniversity faculty hiring networks are known to be hierarchical and to exacerbate various types of inequity. Still, a detailed, historical understanding of hiring dynamics lacks in many academic fields. We focus on the field of mathematics, analyzing over 120,000 records from 150 institutions over seven decades to elucidate the temporal dynamics of hiring doctoral-granting (DG) faculty at the individual and departmental levels. We demonstrate that the disparity between the number of mathematics Ph.D.s awarded and the number of DG faculty positions filled has grown over time. Even institutions with the best records of DG faculty placement have experienced a temporal decline in the probability of their graduates obtaining a DG faculty position. By quantifying the mathematical prestige of each department with a network statistic, authority centrality, we find an approximately linear relationship between the log of the prestige of one’s Ph.D. institution and the log of the probability of obtaining a faculty position. Moreover, we observe associations suggesting that the probability of DG faculty placement has decreased over time and is smaller for women than for men. On the departmental level, a group of 14 elite departments dominated the authority centrality of the entire network between 1950 and 2019. Strikingly, one department within this elite group increased its centrality scores consistently, which hints at the possibility for a department to improve its prestige. This analysis highlights the challenges of transitioning from Ph.D. holder to faculty member in mathematics
Assessing the Language of 2-year-olds: From Theory to Practice
Get PDFEarly screening for language problems is a priority given the importance of language for success in school and interpersonal relationships. The paucity of reliable behavioral instruments for this age group prompted the development of a new touchscreen language screener for 2-year-olds that relies on language comprehension. Developmental literature guided selection of age-appropriate markers of language disorder risk that are culturally and dialectally neutral and could be reliably assessed. Items extend beyond products of linguistic knowledge (vocabulary and syntax) and tap the process by which children learn language, also known as fast mapping. After piloting an extensive set of items (139), two phases of testing with over 500 children aged 2; 0–2; 11 were conducted to choose the final 40-item set. Rasch analysis was used to select the best fitting and least redundant items. Norms were created based on 270 children. Sufficient test-retest reliability, Cronbach\u27s alpha, and convergent validity with the MB-CDI and PPVT are reported. This quick behavioral measure of language capabilities could support research studies and facilitate the early detection of language problems
Prevalence, Co-Occurring Difficulties, and Risk Factors of Developmental Language Disorder: First Evidence for Mandarin-Speaking Children in a Population-Based Study
Get PDFDevelopmental language disorder (DLD) is a condition that significantly affects children\u27s achievement but has been understudied. We aim to estimate the prevalence of DLD in Shanghai, compare the co-occurrence of difficulties between children with DLD and those with typical development (TD), and investigate the early risk factors for DLD
Malthi in Media: Peopling an Ancient Village in Virtual Space
Get PDFSTRIDE Project A Digital Archaeology of Malthi, Greece
Digital applications have increased the possibilities for the visualization of archaeological material. Here are presented two reconstructions of the Bronze Age settlement Malthi, created using Minecraft and Twine, both readily accessible programs. These recreations draw on data from archaeological work at the site and are intended to depict alternative interpretations of the settlement, allowing for the uncertainty inherent in archaeology. They are likewise intended to invite interaction with the site beyond physically visiting, with the goal of increasing participation in the formation of knowledge about Malthi. The approach advocated here is applicable to other projects struggling with ambiguous data.
Additional files:
File name: MalthiTwine_Edited_Final_4Sept23.html Title: Malthi in Twine Author: Nora Sullivan, Annika Lof
File names: Instructions for Opening Zipped Java MC World; Java MC Malthi 1m_2blocks clean.zip Title: Malthi in Minecraft, Unpopulated (Java) Author: Sarah Kam
File names: Instructions for Opening MC Windows Populated Malthi; Populated Malthi.mcworld Title: Malthi in Minecraft, Populated (Windows/Bedrock) Author: Sarah Kam, Aurora Bagle
New Advances in Long-Term Monitoring of Storm-Deposited Boulder Ridges Along Rocky Shorelines of San Salvador Island, Bahamas
Get PDFBeginning in January 2012, we have monitored two boulder ridges on San Salvador: Singer Bar Point (SBP, length ~790 m) along the reef- and lagoon-protected northern coast and The Gulf (TG, length ~460 m) on the island’s high-energy southern coast. This long-term monitoring aims at documenting changes in ridge morphology and distribution, and the direction and amount of movement of individual boulders to gain insights into the intensity and effects of storms on these coastal areas.
In the initial stage of our investigations, the largest boulders from each site were photographed, GPS-located, measured, and characterized by composition and morphology. Boulders at SBP are generally smaller (15 total; ~150-4000 kg; with most \u3c1500 kg) than those at TG (12 original; ~700-6500 kg; most \u3e1000 kg). Our monitoring surveys from January 2013, 2016, and 2017, after Hurricanes Sandy (October 2012), Joaquin (October 2015), and Matthew (October 2016), respectively, indicated only modest modifications at SBP, and major changes to TG, where we were unable to relocate 2 boulders post- Sandy, and 5 of the 10 remaining original boulders after Joaquin. Two TG boulders, weighing ~1 and 3 tons, were transported inland to the NNW by 20 and 26 meters, respectively during Hurricane Joaquin, and there was significant movement inland of the entire boulder ridge.
Even though documentation of boulder movement allows calculation of minimum flow velocity needed to initiate transport, our experience indicated that lack of adequate tagging made it challenging or impossible to relocate individual boulders after major storms. This problem was addressed by the application of RFID (radio frequency identification) tagging in June 2019. With a larger cohort of boulders now tagged, our monitoring program is well established to continue into the future, as passive tags are inductively charged by the reader and can remain operational for decades. Drilling to insert small tags (23 and 32 mm long, and \u3c4 mm in diameter) is minimally destructive and also allows tagging of pebbles and cobbles. This is especially important for monitoring at SBP where large boulders are not moved often or much by waves, but smaller-sized sediment movement is significant during storms
Organic Chemistry II
Get PDFThis text has many contributors. It was adapted for use in CHM 223 at Smith College by Kevin Shea with the assistance of a Smith College Library OER Incentive Grant.https://scholarworks.smith.edu/textbooks/1005/thumbnail.jp
Temperature and Convictions: Evidence from India
Get PDFHigh temperatures have been shown to affect human cognition and decision-making in a variety of settings. In this paper, we explore the extent to which higher temperatures affect judicial decision-making in India. We use data on judicial decisions from the Indian eCourt platform, merged with high-resolution gridded daily weather data. We estimate causal effects by leveraging a fixed effects framework. We find that high daily maximum temperatures raise the likelihood of convictions and these results are robust to numerous controls and specifications. Our findings contribute to a growing literature that documents that the negative impacts of rising temperatures are often more severe in low- and middle-income countries