This growing collection consists of scholarly works authored by ASU-affiliated faculty, staff, and community members, and it contains many open access articles. ASU-affiliated authors are encouraged to Share Your Work in KEEP.

Displaying 71 - 80 of 2,326
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Chemical composition affects virtually all aspects of astrobiology, from stellar astrophysics to molecular biology. We present a synopsis of the research results presented at the “Stellar Stoichiometry” Workshop Without Walls hosted at Arizona State University April 11–12, 2013, under the auspices of the NASA Astrobiology Institute. The results focus on

Chemical composition affects virtually all aspects of astrobiology, from stellar astrophysics to molecular biology. We present a synopsis of the research results presented at the “Stellar Stoichiometry” Workshop Without Walls hosted at Arizona State University April 11–12, 2013, under the auspices of the NASA Astrobiology Institute. The results focus on the measurement of chemical abundances and the effects of composition on processes from stellar to planetary scales. Of particular interest were the scientific connections between processes in these normally disparate fields. Measuring the abundances of elements in stars and giant and terrestrial planets poses substantial difficulties in technique and interpretation. One of the motivations for this conference was the fact that determinations of the abundance of a given element in a single star by different groups can differ by more than their quoted errors.

The problems affecting the reliability of abundance estimations and their inherent limitations are discussed. When these problems are taken into consideration, self-consistent surveys of stellar abundances show that there is still substantial variation (factors of ∼2) in the ratios of common elements (e.g., C, O, Na, Al, Mg, Si, Ca) important in rock-forming minerals, atmospheres, and biology. We consider how abundance variations arise through injection of supernova nucleosynthesis products into star-forming material and through photoevaporation of protoplanetary disks. The effects of composition on stellar evolution are substantial, and coupled with planetary atmosphere models can result in predicted habitable zone extents that vary by many tens of percent. Variations in the bulk composition of planets can affect rates of radiogenic heating and substantially change the mineralogy of planetary interiors, affecting properties such as convection and energy transport.

ContributorsYoung, Patrick (Author) / Desch, Steven (Author) / Anbar, Ariel (Author) / Barnes, Rory (Author) / Hinkel, Natalie R. (Author) / Kopparapu, Ravikumar (Author) / Madhusudhan, Nikku (Author) / Monga, Nikhil (Author) / Pagano, Michael (Author) / Riner, Miriam A. (Author) / Scannapieco, Evan (Author) / Shim, Sang-Heon (Author) / Truitt, Amanda (Author) / College of Liberal Arts and Sciences (Contributor)
Created2014-07-01
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Description

This paper studies the effect of targeted observations on state and parameter estimates determined with Kalman filter data assimilation (DA) techniques. We first provide an analytical result demonstrating that targeting observations within the Kalman filter for a linear model can significantly reduce state estimation error as opposed to fixed or

This paper studies the effect of targeted observations on state and parameter estimates determined with Kalman filter data assimilation (DA) techniques. We first provide an analytical result demonstrating that targeting observations within the Kalman filter for a linear model can significantly reduce state estimation error as opposed to fixed or randomly located observations. We next conduct observing system simulation experiments for a chaotic model of meteorological interest, where we demonstrate that the local ensemble transform Kalman filter (LETKF) with targeted observations based on largest ensemble variance is skillful in providing more accurate state estimates than the LETKF with randomly located observations. Additionally, we find that a hybrid ensemble Kalman filter parameter estimation method accurately updates model parameters within the targeted observation context to further improve state estimation.

ContributorsBellsky, Thomas (Author) / Kostelich, Eric (Author) / Mahalov, Alex (Author) / College of Liberal Arts and Sciences (Contributor)
Created2014-06-01
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Description

In this article, we suggest that graduate programs in predominantly white institutions can and should be sites of self-education and tribal nation building. In arguing this, we examine how a particular graduate program and the participants of that program engaged tribal nation building, and then we suggest that graduate education

In this article, we suggest that graduate programs in predominantly white institutions can and should be sites of self-education and tribal nation building. In arguing this, we examine how a particular graduate program and the participants of that program engaged tribal nation building, and then we suggest that graduate education writ large must also adopt an institutional orientation of nation building. We connect Guinier’s notion of democratic merit to our discussion of nation building as a way to suggest a rethinking of “success” and “merit” in graduate education. We argue that higher education should be centrally concerned with capacity building and graduates who aim to serve their communities.

ContributorsBrayboy, Bryan (Author) / Castagno, Angelina E. (Author) / Solyom, Jessica (Author) / College of Liberal Arts and Sciences (Contributor)
Created2014-08-01
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High proportions of autistic children suffer from gastrointestinal (GI) disorders, implying a link between autism and abnormalities in gut microbial functions. Increasing evidence from recent high-throughput sequencing analyses indicates that disturbances in composition and diversity of gut microbiome are associated with various disease conditions. However, microbiome-level studies on autism are

High proportions of autistic children suffer from gastrointestinal (GI) disorders, implying a link between autism and abnormalities in gut microbial functions. Increasing evidence from recent high-throughput sequencing analyses indicates that disturbances in composition and diversity of gut microbiome are associated with various disease conditions. However, microbiome-level studies on autism are limited and mostly focused on pathogenic bacteria. Therefore, here we aimed to define systemic changes in gut microbiome associated with autism and autism-related GI problems. We recruited 20 neurotypical and 20 autistic children accompanied by a survey of both autistic severity and GI symptoms. By pyrosequencing the V2/V3 regions in bacterial 16S rDNA from fecal DNA samples, we compared gut microbiomes of GI symptom-free neurotypical children with those of autistic children mostly presenting GI symptoms. Unexpectedly, the presence of autistic symptoms, rather than the severity of GI symptoms, was associated with less diverse gut microbiomes. Further, rigorous statistical tests with multiple testing corrections showed significantly lower abundances of the genera Prevotella, Coprococcus, and unclassified Veillonellaceae in autistic samples. These are intriguingly versatile carbohydrate-degrading and/or fermenting bacteria, suggesting a potential influence of unusual diet patterns observed in autistic children. However, multivariate analyses showed that autism-related changes in both overall diversity and individual genus abundances were correlated with the presence of autistic symptoms but not with their diet patterns. Taken together, autism and accompanying GI symptoms were characterized by distinct and less diverse gut microbial compositions with lower levels of Prevotella, Coprococcus, and unclassified Veillonellaceae.

ContributorsKang, Dae Wook (Author) / Park, Jin (Author) / Ilhan, Zehra (Author) / Wallstrom, Garrick (Author) / LaBaer, Joshua (Author) / Adams, James (Author) / Krajmalnik-Brown, Rosa (Author) / Biodesign Institute (Contributor)
Created2013-06-03
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Description

Pre-print of the article, and supplementary data tables describing evidence used to show moderate amounts of hybridization among competing theories in systematic biology between 1960 and 1990.

ContributorsSterner, Beckett (Author)
Created2017-02-01
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Description

Introduction: The Arizona State University (ASU) Library chose to particulate in the Ithaka S+R research study on Asian Studies faculty’s research practices and needs. The rationale for the study was as follows:

Asian Studies covers a diverse and vital world region that in recent decades has had major centers of both development

Introduction: The Arizona State University (ASU) Library chose to particulate in the Ithaka S+R research study on Asian Studies faculty’s research practices and needs. The rationale for the study was as follows:

Asian Studies covers a diverse and vital world region that in recent decades has had major centers of both development and conflict. Although different from one another, these fields indicate the importance we place not only in traditional arts and sciences fields but also in the sciences, professions, and area studies that will continue to be important for our society and our universities. This study will generate a richly illustrated description of the field’s practices and needs and make actionable recommendations for how libraries (and others) can best support their research going forward.

The ASU Library is one of 19 university libraries selected to participate in the study. Among the selected libraries were Harvard University, Indiana University, UCLA University, University of Washington, Colorado University, University of Maryland, and University of Texas. Each university was responsible for interviewing 15 scholars involved in Asian Studies using a set of semi-structured interview questions. The identity of the scholars was kept anonymous. Each interview was recorded and transcribed. Each institution will write a report (to be placed in their university repositories) which will be passed up to the Ithaka S+R team who will write a report summarizing the entire project.

This local research project was implemented by a researcher at ASU with guidance on the research methodology and data analysis provided by Ithaka S+R. The ASU researcher participated in an Ithaka S+R training session which encouraged consistency across all the participating institutions. This report is organized This report is organized into seven sections providing an overview of Asian Studies at ASU and a discussions of the issues resulting from this study. Lastly, recommendations for the ASU Library to support Asian Studies.

ContributorsGabbard, Ralph (Creator)
Created2018-02-02