Thanks for the great questions, Reddit! We’re done answering for the day and are off to finish preparations for tomorrow’s Earth Gravity Assist maneuver. Tomorrow, NASA’s asteroid-hunting spacecraft, OSIRIS-REx, will fly by Earth and use the planet’s gravitational pull to slingshot itself onto a new trajectory. This maneuver, called an Earth Gravity Assist (EGA), will put the spacecraft on course to rendezvous with a primitive, near-Earth asteroid named Bennu. The spacecraft will reach Bennu next year, map the asteroid, and collect a sample of surface material (called regolith) that will be returned to Earth for study in 2023. This mission will bring the largest sample of space material to Earth since the Apollo missions’ lunar samples. We’re a group of scientists and engineers based at the University of Arizona—home to the mission’s Principal Investigator’s office and the Science Processing Operations Center—ready to answer your questions about OSIRIS-REx, EGA, and the mission to collect some of the oldest material in the solar system. We’ll be online from 1 to 3 pm PST (4 to 6 pm EST). Ask us anything! Proof: https://www.asteroidmission.org/reddit-ask-us-anything-earth-gravity-assist/ Dr. Dante Lauretta, OSIRIS-REx Principal Investigator Sara Knutson, OSIRIS-REx Science Operations Lead Engineer Dr. Ellen Howell, OSIRIS-REx Senior Research Scientist, Asteroid Spectroscopy Joshua Nelson, OSIRIS-REx Science Operations Engineer Anjani Polit, OSIRIS-REx Mission Implementation Systems Engineer Heather Enos, OSIRIS-REx Deputy Principal Investigator Dr. Lucy Lim, OSIRIS-REx Assistant Project Scientist
The HeLa cell line, named after the patient Henrietta Lacks, was one the first human cell lines to be used for tissue culture. In the decades since its origin, it has become a feature in labs across the world. Despite its longevity, repeated detection of most HeLa marker chromosomes have lead the scientific community to view HeLa as a stable cell line and its corresponding findings to be reproducible. However, to date no investigation has examined other meaningful aspects of HeLa's genomic variability, such has whether HeLa's modal chromosome number remains constant. Considering the importance of a cell line's karyotype with respect to reproducibility, I sought to examine the stability of HeLa's karyotype by examining HeLa's modal chromosome number as reported in the literature.
Boyer’s framework of scholarship was published before significant growth in digital technology. As more digital products are produced by medical educators, determining their scholarly value is of increasing importance. This scoping systematic review developed a taxonomy of digital products and determined their fit within Boyer’s framework of scholarship. We conducted a broad literature search for descriptions of digital products in the medical literature in July 2013 using Medline, EMBASE, ERIC, PSYCHinfo, and Google Scholar. A framework analysis categorized each product using Boyer’s model of scholarship, while a thematic analysis defined a taxonomy of digital products. 7422 abstracts were found and 524 met inclusion criteria. Digital products mapped primarily to the scholarship of teaching (85.4%) followed by integration (7.6%), application (5.5%), and discovery (1.5%). A taxonomy of 19 categories was defined. Web-based or computer assisted learning (41%) was described most frequently. We found that digital products are well described in medical literature and fit into Boyer’s framework of scholarship and proposed a taxonomy of digital products that parallel traditional forms of the scholarship of teaching and learning. This research should inform the development of tools to examine the impact and quality of digital products.
Hello Reddit, we will be answering questions starting at 1 PM EST. We have a large team of scientists from many different timezones, so we will continue answering questions throughout the week. Keep the questions coming! About this Discovery: On January 4, 2017 the LIGO twin detectors detected gravitational waves for the third time. The gravitational waves detected this time came from the merger of 2 intermediate mass black holes about 3 billion lightyears away! This is the furthest detection yet, and it confirms the existence of stellar-mass black holes. The black holes were about 32 solar masses and 19 solar masses which merged to form a black hole of about 49 solar masses. This means that 2 suns worth of energy was dispersed in all directions as gravitational waves (think of dropping a stone in water)! More info can be found here Simulations and graphics: Simulation of this detections merger Animation of the merger with gravitational wave representation The board of answering scientists: Martin Hendry Bernard F Whiting Brynley Pearlstone Kenneth Strain Varun Bhalerao Andrew Matas Avneet Singh Sean McWilliams Aaron Zimmerman Hunter Gabbard Rob Coyne Daniel Williams Tyson Littenberg Carl-Johan Haster Giles Hammond Jennifer Wright Sean Levey Andrew Spencer The LIGO Laboratory is funded by the NSF, and operated by Caltech and MIT, which conceived and built the Observatory. The NSF led in financial support for the Advanced LIGO project with funding organizations in Germany (MPG), the U.K. (STFC) and Australia (ARC) making significant commitments to the project. More than 1,000 scientists from around the world participate in the effort through the LIGO Scientific Collaboration, which includes the GEO Collaboration. LIGO partners with the Virgo Collaboration, which is supported by Centre National de la Recherche Scientifique (CNRS), Istituto Nazionale di Fisica Nucleare (INFN) and Nikhef, as well as Virgo’s host institution, the European Gravitational Observatory, a consortium that includes 280 additional scientists throughout Europe. Additional partners are listed at: http://ligo.org/partners.php.
How easy is it to lose a basketball game, assuming both sides want to lose? Now, let’s be clear: I do not advocate trying to lose in any sport. Please take this essay primarily as a source of amusement – an intellectual exercise, if you will. Actually trying to lose is not only bad sportsmanship, but it may be cause players to be suspended, coaches to be fired, and teams to be fined and even disqualified from leagues. Quite possibly, trying to lose may actually be illegal. At its worst, someone might get hurt and the perpetrator may even get jail time. However, imagining that everyone is OK with trying to lose, and that no one gets hurt, then let’s have some fun and see what can be done to lose a basketball game.
Factor analysis of allele frequencies was used to identify signals of polygenic selection on human intelligence. Four SNPs which reached genome-wide significance in previous meta-analyses were used. Allele frequencies for 26 population were obtained from 1000 Genomes. The resulting factor scores were highly correlated to average national IQ (r=0.92). A regression of IQ differences between subcontinental groups on the 4 SNPs g factor and an index of genome-wide genetic distances showed the former was an independent and significant predictor (Beta= 1.14), whereas genome-wide distances lost all predictive power. This finding suggests that the relationship between the 4 SNPs g factor and IQ is due to natural selection on a specific phenotype and not the result of a spurious correlation arising from genome-wide evolutionary processes such as random drift or migrations. A regression of IQs on genetic factor scores of developed countries was used to estimate the predicted genotypic IQs of developing countries. The residuals (difference between predicted and actual scores) were negatively correlated to per capita GDP and Human Development Index, implying that countries with low socioeconomic conditions have not yet reached their full intellectual potential.
I present a checklist of acquisition parameters for inclusion in the methods section of an fMRI paper. The current list expands and updates the list that was given in the 2008 paper from Poldrack et al. (I have reproduced below the section on acquisition that appeared in that 2008 paper.) The emphasis is on fMRI experiments that use 1.5 to 3 T scanners with standard hardware available today, but the list should work reasonably well for 7 T experiments as well. I further assume that fMRI is performed with 2D multi-slice EPI or spiral scanning and uses BOLD contrast, but parameter reporting for 3D sequences and other k-space trajectories as well as non-BOLD contrast should be feasible. The first full version of the checklist, version 1.1, was presented in January, 2013. Version 1.2 was released in December, 2014. This version is denoted 1.3 and will be the final series 1.x release. Release notes for this version appear below. The checklist was initially developed based on my experience with Siemens scanners but I have attempted to use generic descriptions as far as possible. Version 2.0 is planned for the end of 2015 and will include vendor-specific nomenclature under each parameter.
Time travel has captured the public imagination for much of the past century, but little has been done to actually search for time travelers. Here, three implementations of Internet searches for time travelers are described, all seeking a prescient mention of information not previously available. The first search covered prescient content placed on the Internet, highlighted by a comprehensive search for specific terms in tweets on Twitter. The second search examined prescient inquiries submitted to a search engine, highlighted by a comprehensive search for specific search terms submitted to a popular astronomy web site. The third search involved a request for a direct Internet communication, either by email or tweet, pre-dating to the time of the inquiry. Given practical verifiability concerns, only time travelers from the future were investigated. No time travelers were discovered. Although these negative results do not disprove time travel, given the great reach of the Internet, this search is perhaps the most comprehensive to date.
This article examines the U.S. Army’s Comprehensive Soldier Fitness (CSF) program from a scientific, ethical, and pragmatic viewpoint. CSF is one of the largest single applications of psychological research in history, intended to develop “resilience” in every U.S. Army soldier. I highlight several areas where the available information about the program either suggests the likelihood of specific problems, or is insufficient to allow the research community to evaluate the effectiveness of CSF independently of the claims made by its originators and assurances given by other non-disinterested parties. In particular, I question (a) whether a program based on resiliency training for school-aged children can hope to address the serious mental trauma, including PTSD, faced by soldiers deployed to war zones; (b) whether the instruments used to measure the performance of the program are reliable, valid, and appropriate for the circumstances in which they are being used, and (c) whether the design and delivery of the program takes sufficient account of the conflicting real-world demands placed on the individuals involved. I conclude that the program appears to have a number of potentially problematic aspects that require wider scrutiny from psychological researchers and practitioners.
I examined the gender balance of speakers at annual meetings of the Society for the Neurobiology of Language from 2009–2015, and in authors in the journal Brain and Language from the beginning of 2015. Of the conference speakers, 30% (14/47) were women, with no year having more than 38% speakers who were women. In contrast, approximately half of the authors (82/159) published in Brain and Language were women. These findings suggest intentional strategies are needed to achieve conference speaker gender balance.