Carleton College is a private non-sectarian, coeducational, liberal arts college in Northfield, Minnesota. The college enrolls 2,035 undergraduate students, and employs 220 full-time faculty members. In its 2014 edition of college rankings, U.S. News & World Report ranked Carleton College the seventh-best liberal arts college in the United States and ranked Carleton number one for undergraduate teaching at a national liberal arts college. Wikipedia.
Mohrig J.R.,Carleton College
Accounts of Chemical Research | Year: 2013
Many mechanistic and stereochemical studies have focused on the breaking of the C-H bond through base-catalyzed elimination reactions. When we began our research, however, chemists knew almost nothing about the stereospecificity of addition-elimination reactions involving conjugated acyclic carbonyl compounds, even though the carbonyl group is a pivotal functional group in organic chemistry. Over the last 25 years, we have studied the addition-elimination reactions of β-substituted acyclic esters, thioesters, and ketones in order to reach a comprehensive understanding of how electronic effects influence their stereochemistry. This Account brings together our understanding of the stereochemistry of 1,2-elimination and proton-transfer reactions, describing how each study has built upon previous work and contributed to our understanding of this field.When we began, chemists thought that anti stereospecificity in base-catalyzed 1,2-elimination reactions occurred via concerted E2 mechanisms, which provide a smooth path for anti elimination. Unexpectedly, we discovered that some E1cBirrev reactions produce the same anti stereospecificity as E2 reactions even though they proceed through diffusionally equilibrated, "free" enolate-anion intermediates. This result calls into question the conventional wisdom that anti stereochemistry must result from a concerted mechanism. While carrying out our research, we developed insights ranging from the role of historical contingency in the evolution of hydratase-dehydratase enzymes to the influence of buffers on the stereochemistry of H/D exchange in D2O.Negative hyperconjugation is the most important concept for understanding our results. This idea provides a unifying view for the largely anti stereochemistry in E1cBirrev elimination reactions and a basis for understanding the stereoelectronic influence of electron-withdrawing β-substituents on proton-transfer reactions. © 2013 American Chemical Society.
Tasson J.D.,Carleton College
Reports on Progress in Physics | Year: 2014
The realization that Planck-scale physics can be tested with existing technology through the search for spacetime-symmetry violation brought about the development of a comprehensive framework, known as the gravitational standard-model extension (SME), for studying deviations from exact Lorentz and CPT symmetry in nature. The development of this framework and its motivation led to an explosion of new tests of Lorentz symmetry over the past decade and to considerable theoretical interest in the subject. This work reviews the key concepts associated with Lorentz and CPT symmetry, the structure of the SME framework, and some recent experimental and theoretical results. © 2014 IOP Publishing Ltd.
Agency: NSF | Branch: Continuing grant | Program: | Phase: LIGO RESEARCH SUPPORT | Award Amount: 140.00K | Year: 2015
The observation of gravitational waves by the Laser Interferometer Gravitational-wave Observatory (LIGO) will be a tremendous scientific accomplishment, but the resources provided through this grant will create many other positive opportunities. Carleton College is a leader in producing future scientists. This project will provide research opportunities to students with interests in physics and statistics, and help train them to become the next generation of scientists. Carleton students are eager to participate in exciting research, and their interest in gravitational wave astronomy, and science in general, is large. The computational statistical methods developed as a consequence of this project have, and will continue to have significant influence in other scientific fields: astrophysics, chaos studies, and gravitational wave detectors in space. The project will also continue to provide material that will improve teaching at the college level; subjects that will benefit from the science covered in this project include optics, general relativity, and statistics. This project also creates opportunities for scientific outreach; high school students and high school teachers will continue to be exposed to the wonder and significance of LIGOs research, and this outreach creates much excitement for science and physics. Finally, the research work of this project promotes international scientific collaboration. Albert Einstein predicted the existence of gravitational waves in 1916; a century later we should actually observe gravitational waves, and consequently the scientific and educational benefit will be tremendous.
Events seen by LIGO will produce a wealth of astrophysical information, the extraction of which will require advanced techniques in data analysis, parameter estimation, and statistics. Detector characterization work will provide scientists with confidence in the quality of the data, and the performance of the detectors. Carleton College will continue with its significant efforts in identifying and characterizing noise in LIGO data; this information will be fed back to the interferometer operators in order to improve the detector performance. Carleton and colleagues are researching how to eliminate magnetic field noise from the Schumann resonances that is coherent in the LIGO-Virgo detector network. Carleton will use LIGO data to observe a cosmologically produced stochastic gravitational wave background. Carleton will contribute to the effort to detect long duration gravitational waves by correlating data from two detectors, and using pattern recognition techniques to look for signals. The Carleton team will develop Bayesian parameter estimation methods to extract physical parameters associated with core collapse supernova produced gravitational wave signals.
Agency: NSF | Branch: Standard Grant | Program: | Phase: Chemistry of Life Processes | Award Amount: 293.51K | Year: 2016
With this award, the Chemistry of Life Processes Program in the Chemistry Division is funding Dr. Christopher Calderone from Carleton College. Small molecules, produced by microbial cells and known as non-ribosomal peptides are the source of dozens of clinically useful medicines, including antibiotics and anticancer drugs. The structures of these molecules is incredibly complex and diverse, but they are all produced by assembly lines that are made up of only a handful of different types of repeating biological machinery. This research is identifying new types of biological assembly line machinery that can explain the origins of a large number of non-ribosomal peptides and ultimately allow the design of new varieties that are not currently accessible. The new varieties could have valuable therapeutic potential. An additional important component of this project is the development of the LearningWorks program in downtown Minneapolis to teach underserved middle-school students molecular biology concepts and techniques.
This research is aimed at characterizing a predicted subclass of condensation domains involved in non-ribosomal peptide biosynthesis. Though non-ribosomal peptide synthetases have been extensively studied over the past decades, mechanistic reasoning and bioinformatic analysis suggests that there is a broadly distributed, but as-yet uncharacterized, subclass of the condensation domain involved that is able to catalyze dehydration in addition to canonical amide-bond formation. These experiments are aimed at reconstituting the biosynthetic pathway from Pseudomonas aeruginosa that leads to aminomethoxy-trans-butenoic acid (AMB) in vitro, the centerpiece of which is a predicted condensation domain-catalyzed dehydration. In addition, this funding supports the development of educational modules for incorporation into the undergraduate teaching lab and the curriculum of LearningWorks, a public-private partnership in downtown Minneapolis that serves middle-school students from underserved populations.
Agency: NSF | Branch: Standard Grant | Program: | Phase: Genetic Mechanisms | Award Amount: 160.05K | Year: 2015
On the main, this research project lies in the broad interdisciplinary area between geometric topology and quantum physics. Many of the motivating conjectures come from physics, and their mathematical solutions would be of interest to theoretical physicists. A second part of the project concerns the topological characteristics of biopolymers like DNA and proteins. This can be important from a pharmaceutical perspective, as some drugs can be designed to target topological characteristics which affect specific biological functions. Besides its research goals, the project has a strong educational component. Many of the proposed problems are intended for research with undergraduate students. Through her research, teaching and other outreach activities, the PI intends to expand the reach of mathematics, for example to historically under-represented groups and to other audiences not usually exposed to cutting edge mathematics.
This project will explore the extent to which the Kauffman skein algebra and its generalizations can serve as intermediaries between quantum topology and hyperbolic geometry. The PI will study the representation theory of the Kauffman skein algebra, paying particular attention to the representation coming from the Witten-Reshetikhin-Turaev theory. The long-term, overarching goal is to construct and classify all representations of the Kauffman skein algebra, a goal which this project will advance. The project considers the algebraic structure of the Kauffman skein algebra and of its generalizations (e.g., ones that allow arcs on the surface). In addition, the project includes problems investigating which types of topologically complex structures, like knots, links, and non-planar graphs, are possible in biopolymers like DNA and proteins.
Agency: NSF | Branch: Standard Grant | Program: | Phase: TRIBAL COLLEGE & UNIVERS PROGR | Award Amount: 18.93K | Year: 2016
At least half of the 7,000 languages worldwide will cease to be spoken by the end of the current century. Native American languages represent a portion of those languages that will fall silent, that is, have no remaining first language fluent speakers. The Native American Languages Act, passed by the U.S. Congress in 1990, enacted into policy the recognition of the unique status and importance of Native American languages. Many Native American communities are working hard to create new speakers while elder speakers are still here. One challenge in creating new speakers is the lack of effective teaching materials. Another challenge is having a deep enough understanding of the complexities of the particular language, since a deeper linguistic understanding of a language can be used to train teachers, to develop effective pedagogical resources, and to help learners move from beginner levels to more intermediate and advanced levels of complexity. Other challenges include the lack of adequate language documentation and resources, including dictionaries and reference grammars. Cases of successful language revitalization often involve partnerships between tribal communities and organizations with linguists and other academics. Those partnerships often take years to develop, but their results include broader impacts like Native Americans earning degrees and other credentials in linguistics and other social sciences. In this project, a workshop and follow up meetings will be held to try to address these challenges and develop support for language restoration for Dakota, a Native American language of the Upper Midwest. This will bring together linguists, computer scientists, and tribal experts in the Dakota language. Broader impacts include capacity building in the social sciences and computational infrastructure in the tribes educational department and tribal college, the development of better electronic and other resources to support Dakota language learning, and potential opportunities for undergraduates at two institutions to participate in authentic research experiences in linguistics.
Participants in these workshops to support the Dakota language include the Sisseton-Wahpeton Oyate of the Lake Traverse Reservation in eastern South Dakota, the Sisseton-Wahpeton Oyate Dakotah Language Institute, and Carleton College in southern Minnesota. Dakota is a member of the large Siouan language family, spoken from Canada to Arkansas with a number of close relatives in the Upper Midwest, but all are endangered, with some severely threatened and even lacking first language speakers. The Dakotah Language Institute of the Sisseton-Wahpeton Oyate and Carleton will explore the documentation, analysis, preservation, and revitalization of Dakota at a two-day workshop in August 2016, and follow up with a subsequent meeting at Sisseton-Wahpeton in the fall. Funding will also cover the costs of attending the Linguistic Society of America meeting in January 2017 for tribal educators, including those at the tribal college, and Carleton College participants. This conference is the premier annual meeting of American linguists and is the largest gathering each year of those who focus on Native American languages. The goal of these activities is to bring together potential partners in the work to create a thorough, up-to-date description of the language, and developing tools and materials to facilitate instruction in Dakota to children. One long-term goal of the project is to develop a clear analysis of Dakota that is informed by current language science. A second goal is to construct an array of resources for classroom and extracurricular use at the Oyate. The NSF Tribal Colleges and Universities (TCUP) program in EHR is providing support for tribal college participation in this project.
Agency: NSF | Branch: Standard Grant | Program: | Phase: NSF INCLUDES | Award Amount: 300.00K | Year: 2016
Part I - At the same time communities all over the US are struggling to deal with climate change, resilience, and environmental justice, the nation faces a shortage of geoscientists who can work on these issues. This shortage is especially acute for marginalized and underserved communities. Gaps in the pathways to careers in geoscience begin as early as middle school?the last time many students encounter Earth science content in the classroom. To address these challenges, this project will create opportunities for students in three diverse communities (Atlanta, GA; San Bernardino, CA; and Oklahoma) to develop their scientific skills and knowledge while working on authentic, local problems as they progress from middle school to college and beyond, into the workforce.
Part II - The project design is informed by research findings that students are more engaged and invested in learning science when it is connected to issues of concern to their local community and that use of authentic, mentored, real world research experiences increase retention and persistence. Bringing together partners who have led relevant, successful national efforts with partners in the three regions the project team will design and begin implementation of inclusive pathways that lead from an early interest in Earth to careers that require geoscience skills and knowledge. Each pathway will include multiple opportunities for students to 1) learn geoscience in the context of compelling local issues, 2) use geoscience to address local challenges, and 3) explore geoscience career pathways. Experience gained by initial program partners and regional pilots will be used to create national support structures for developing integrated geoscience pathways and a collective action framework for expanded partnerships.
Agency: NSF | Branch: Standard Grant | Program: | Phase: S-STEM:SCHLR SCI TECH ENG&MATH | Award Amount: 1.00M | Year: 2016
This National Science Foundation (NSF) Scholarships in Science, Technology, Engineering, and Mathematics (S-STEM) project at Carleton College in Northfield, Minnesota will provide scholarships for talented, low-income students pursuing bachelors degrees in the sciences and mathematics. In addition to scholarships, the program will provide academic support to increase the persistence of academically talented, low-income students. Project efforts will include a study of the means of improving the second-year experience of STEM students and a focus on increasing the number of STEM faculty with direct expertise in fostering the success of those STEM students from low-income backgrounds that are at risk for non-completion of STEM degrees. The results of this project will be applicable to other institutions that do not require students to declare a major until the end of the sophomore year and are seeking to improve the retention of students in STEM programs. Scholarships and support for academically strong students, who may not otherwise be able to afford college, will help to produce a well-trained workforce that will contribute to the economic vitality of Minnesota and the nation.
The project builds on several existing initiatives at Carleton and introduces additional effective students support practices targeted at areas expected to be particularly critical to student success. The project will refine and evaluate current first-year cohort strategies in support of student learning, student sense of belonging, and student drive to succeed in STEM. A year-long civic-engagement research project will be implemented for students in the sophomore year. The effect of this research participation on student attitudes will be evaluated. For students in the junior and senior years, opportunities for teaching-as-learning will be implemented. The project activities will also enlarge the pool of Carleton STEM faculty with direct expertise in fostering the success of STEM students from low-income backgrounds. This project will advance understanding of: the effect of first-year and second-year engaged-learning research projects on student perseverance and success in introductory courses; the effect of the second-year STEM civic-engagement research and advising on student choice of STEM major; and the impact of faculty advising and mentoring of students as well as faculty design of introductory courses. The evaluation of the students sophomore-year experience will be of particular value to colleges in which students declare majors at the end of the second year. The lessons learned that emerge from the program will be disseminated widely to the STEM education community and help increase understanding of the attributes and practices of successful student scholarship and support programs.
Agency: NSF | Branch: Continuing grant | Program: | Phase: Chemical Synthesis | Award Amount: 221.39K | Year: 2016
In this project funded by the Chemical Synthesis Program of the Chemistry Division, Professor Matthew T. Whited of Carleton College works with a research group of undergraduate students to investigate the preparation and reactivity of new complexes featuring transition metal/main-group bonds with acidic and basic sites. In these systems an electron-rich transition metal works synergistically with an electron-poor main-group to facilitate difficult reactions. This allows the development of new selective transformations of industrially and environmentally important molecules such as carbon dioxide and hydrocarbons. This project is developing earth abundant metal catalysts to convert carbon dioxide into chemical feedstocks. This is important contribution to achieving sustainability. As such the project contributes to the Sustainable Chemistry, Engineering, and Materials (SusChEM) effort. Professor Whited is also developing course-based undergraduate research experiences (CUREs) at Carleton College and working with an outreach program to bring local high-school students into Carleton College chemistry laboratories.
This project seeks to understand and develop reactions around late-metal/main-group interactions using complexes featuring constrained metal-silicon single and multiple bonds as prototypes. In order to constrain the metal-silicon linkage, the silyl group is tethered into an easily modified pincer-type ligand. The electronic frustration resulting from the disparity between electron-rich late metals and electropositive silicon, combined with the kinetic lability of bonds to each, allows the development of a cooperative approach to strong-bond activation with applications in catalytic hydrocarbon oxidation and carbon dioxide reduction. Spectroscopic and reactivity studies of metal/silicon systems motivate the expansion of this research to include pincers with boryl and carbyl/carbene donors as well as to catalysis with earth-abundant metals. The project provides a training ground for undergraduate researchers and supports the expansion of both college- and high-school education efforts related to Dr. Whiteds interests in inorganic synthesis and X-ray crystallography.
Agency: NSF | Branch: Standard Grant | Program: | Phase: Campus Cyberinfrastrc (CC-NIE) | Award Amount: 349.90K | Year: 2014
This project broadly improves Carletons cyberinfrastructure design and integration to ensure system performance and reliability, including rate and security of data transfer, in support of computational science. Project goals include (1) Upgrading campus Internet2 connection to the Northern Lights GigaPOP to a speed of 10Gbps; (2) Designing and building a prototype Science DMZ to provide immediate support for researchers constrained by the current limitations of the campus building and data infrastructures; (3) Blending the experience gained from the prototype Science DMZ with the ongoing work of the Carleton Science Planning Group to formulate the most effective plan for end-to-end research connectivity, with attention to proposed expansion and remodeling of campus science facilities; (4) Leveraging the knowledge and experience gained by the faculty and staff in this process into the ongoing collaboration efforts to facilitate shared research nationally and internationally. The projects design and implementation is based on best practices developed by successful NSF-funded projects, with particular focus on design of a Science DMZ to meet the needs of researchers at a research-oriented liberal arts college. The design and implementation of the project improves high bandwidth connections accessible to end-users in order to improve network performance and predictability for a wide range of applications. The project addresses specific cyberinfrastructure limitations that impede faculty research with external research partners. Project leaders will present findings regarding design challenges and innovations at national workshops, meetings, and conferences in order to advance small-institution understanding of SDN across wide-area and campus cyberinfrastructure.