Rotational Spectral Unmixing of Exoplanets: Degeneracies between Surface Colors and Geography

Unmixing the disk-integrated spectra of exoplanets provides hints about heterogeneous surfaces that we cannot directly resolve in the foreseeable future. It is particularly important for terrestrial planets with diverse surface compositions like Earth. Although previous work on unmixing the spectra of Earth from disk-integrated multi-band light curves appeared successful, we point out a mathematical degeneracy between the surface colors and their spatial distributions. Nevertheless, useful constraints on the spectral shape of individual surface types may be obtained from the premise that albedo is everywhere between 0 and 1. We demonstrate the degeneracy and the possible constraints using both mock data based on a toy model of Earth, as well as real observations of Earth. Despite the severe degeneracy, we are still able to recover an approximate albedo spectrum for an ocean. In general, we find that surfaces are easier to identify when they cover a large fraction of the planet and when their spectra approach zero or unity in certain bands.Comment: 11 pages, 7 figures, published in AJ. Minor text updates from previous versio

The Effect of Occupational Licensing on Women and Minorities in Utah

The Effect of Occupational Licensing on Women and Minorities in Utah Jacob Caldwell, Colton Cowan, Olivia Mackelprang, Fiona Harrigan All state governments require occupational licenses in order to work in certain fields. Previous research and economic theory suggest occupational licenses are used to restrict the entry of workers into a chosen field, thus lowering the competition in a certain field (Young, 2012). Though costly to the licensed businesses, the lowered competition results in the ability to charge higher prices which may result in a net gain for the licensee (Stigler, 1971; Peltzman, 1976).We collect, analyze, and create an index from data on Utah\u27s licensed occupations to explore how occupational licensing affects women and minorities. In our ordinary least squares regression we focus on price to submit an application, years of training, and cost of necessary exams to determine which fields were most impacted by occupational licensure. We then compare the data we used with the demographic data of workers in those fields. We find that women and minorities are disproportionately affected - meaning they bear more of the costs from occupational licensing than other segments of the population. This suggests laws meant to protect the population can sometimes come at the cost of other segments of the population. Young, David S. (2002). Occupational Licensing. Library of Economics and Liberty. Retrieved from: http://www.econlib.org/library/Enc1/OccupationalLicensing.html#abouttheauthor Peltzman, Samuel. (1976). Toward a more general theory of regulation. The Journal of Law & Economics, Vol. 19, 211-240. Stigler, George J. (1971). The Theory of Economic Regulation. The Bell Journal of Economics and Management Science, Vol. 2, No. 1. 3-21. Faculty Mentor: Ryan Yonk: [email protected]

Individual Differences in Dopamine Are Associated with Reward Discounting in Clinical Groups But Not in Healthy Adults.

Some people are more willing to make immediate, risky, or costly reward-focused choices than others, which has been hypothesized to be associated with individual differences in dopamine (DA) function. In two studies using PET imaging, one empirical (Study 1: N = 144 males and females across 3 samples) and one meta-analytic (Study 2: N = 307 across 12 samples), we sought to characterize associations between individual differences in DA and time, probability, and physical effort discounting in human adults. Study 1 demonstrated that individual differences in DA D2-like receptors were not associated with time or probability discounting of monetary rewards in healthy humans, and associations with physical effort discounting were inconsistent across adults of different ages. Meta-analytic results for temporal discounting corroborated our empirical finding for minimal effect of DA measures on discounting in healthy individuals but suggested that associations between individual differences in DA and reward discounting depend on clinical features. Addictions were characterized by negative correlations between DA and discounting, but other clinical conditions, such as Parkinson's disease, obesity, and attention-deficit/hyperactivity disorder, were characterized by positive correlations between DA and discounting. Together, the results suggest that trait differences in discounting in healthy adults do not appear to be strongly associated with individual differences in D2-like receptors. The difference in meta-analytic correlation effects between healthy controls and individuals with psychopathology suggests that individual difference findings related to DA and reward discounting in clinical samples may not be reliably generalized to healthy controls, and vice versa.SIGNIFICANCE STATEMENT Decisions to forgo large rewards for smaller ones due to increasing time delays, uncertainty, or physical effort have been linked to differences in dopamine (DA) function, which is disrupted in some forms of psychopathology. It remains unclear whether alterations in DA function associated with psychopathology also extend to explaining associations between DA function and decision making in healthy individuals. We show that individual differences in DA D2 receptor availability are not consistently related to monetary discounting of time, probability, or physical effort in healthy individuals across a broad age range. By contrast, we suggest that psychopathology accounts for observed inconsistencies in the relationship between measures of DA function and reward discounting behavior

Backbone NMR resonance assignment of the Abelson kinase domain in complex with imatinib

Imatinib (Glivec or Gleevec) potently inhibits the tyrosine kinase activity of BCR-ABL, a constitutively activated kinase, which causes chronic myelogenous leukemia (CML). Here we report the first almost complete backbone assignment of c-ABL kinase domain in complex with imatini

The Australian Mainstream Media’s Portrayal of Youth Climate Activism and Dissent

The March 2019 School Strikes 4 Climate, predominantly organized by young students, garnered widespread and polarizing media coverage. We aimed to identify how Australian mainstream print news media portrays youth involvement and dissent within climate action movements. A qualitative media framing analysis was conducted to determine how youth climate activists and dissent were presented during the first large-scale youth climate protests in Australia. Australian newspaper articles and opinion pieces (N = 101) were identified via ProQuest and screened. An inductive thematic analysis was conducted in NVivo12. Findings were assessed through a typology of dissent to determine how different forms of dissent were represented in the Australian print news media. The framing of dissent in Australian media coverage was varied, with news articles being more likely to prioritize the voices of young people, while opinion pieces resorted to fear-mongering rhetoric that critiqued and invalidated their agency. Protestors used combinations of dutiful and disruptive dissent to advocate for climate action, with the latter being more effective for challenging systemic drivers of climate change

TACCL: Guiding Collective Algorithm Synthesis using Communication Sketches

Machine learning models are increasingly being trained across multiple GPUs and multiple machines. In this setting, data is transferred between GPUs using communication collectives such as AlltoAll and AllReduce, which can become a significant bottleneck in large models. It is important to use efficient algorithms for collective communication. We introduce TACCL, a tool that allows algorithm designers to guide a synthesizer into automatically generating algorithms for a given hardware configuration and communication collective. TACCL uses the novel communication sketch abstraction to obtain crucial information from the designer that is used to significantly reduce the state space and guide the synthesizer towards better algorithms. TACCL also uses a novel encoding of the problem that allows it to scale beyond single-node topologies. We use TACCL to synthesize algorithms for three collectives and two hardware topologies: DGX-2 and NDv2. We demonstrate that the algorithms synthesized by TACCL outperform the NVIDIA Collective Communication Library (NCCL) by up to 6.7$\times$. We also show that TACCL can speed up end-to-end training of Transformer-XL and BERT models by 11%--2.3$\times$ for different batch sizes.Comment: Accepted at NSDI'23. Contains 17 pages, 11 figures, including Appendi

Bacterial degradation of coal discard and geologically weathered coal:

The biodegradation of coal discard is being intensively studied in South Africa in an effort to develop passive methods for the successful revegetation and rehabilitation of waste dumps, to mitigate pollution, and facilitate mine closure. Bacteria were isolated from slurries of coal tailings and diesel-contaminated soil, screened for coal biodegradation competence, characterized, and the colonization and degradation of coal discard and geologically weathered coal investigated using individual isolates and consortia. Ten novel coal-degrading bacterial strains were isolated and characterized, the gene sequences deposited with GenBank, and the (wild-type) strains deposited at Microbial Culture Collection, India

Structural biology contributions to the discovery of drugs to treat chronic myelogenous leukaemia

A case study showing how the determination of multiple cocrystal structures of the protein tyrosine kinase c-Abl was used to support drug discovery, resulting in a compound effective in the treatment of chronic myelogenous leukaemia