The mitotic spindle, an apparatus that segregates chromosomes during cell division, may be more complex than the standard textbook picture suggests, according to researchers at the Harvard School of Engineering and Applied Sciences (SEAS).The findings, which result from quantitative measurements of the mitotic spindle, appear in the journal Cell.The researchers used a femtosecond laser to slice through the strands of the organelle and then performed a mathematical analysis to infer the microscopic structure of the spindle from its response to this damage.“We’ve been using this nanosurgery technique to understand the architecture and assembly of the spindle in a way that was never possible before,” says Eric Mazur, Balkanski Professor of Physics and Applied Physics at Harvard, who co-authored the study. “It’s very exciting.”The spindle, which is made of protein strands called microtubules, forms during cell division and segregates chromosomes into the daughter cells. It was previously unclear how microtubules are organized in the spindles of animal cells, and it was often assumed that the microtubules stretch along the length of the entire structure, pole to pole.Mazur and his colleagues demonstrated that the microtubules can begin to form throughout the spindle. They also vary in length, with the shortest ones close to the poles.“We wondered whether this size difference might result from a gradient of microtubule stabilization across the spindle, but it actually results from transport,” says lead author Jan Brugués, a postdoctoral fellow at SEAS. “The microtubules generally nucleate and grow from the center of the spindle, from which point they are transported towards the poles. They disassemble over the course of their life span, resulting in long, young microtubules close to the midline and older, short microtubules closer to the poles.”“This research provides concrete evidence for something that we’ve only been able to estimate until now,” Brugués adds.Mazur and Brugués worked with Daniel Needleman, assistant professor of applied physics and molecular and cellular biology at Harvard, and Valeria Nuzzo, a former postdoctoral fellow in Mazur’s lab at SEAS, to bring the tools of applied physics to bear on a biological question.The team used a femtosecond laser to make two small slices perpendicular to the plane of growth of the spindle apparatus in egg extracts of the frog species Xenopus laevis.They were then able to collect quantitative data on the reconstruction of the spindle following this disruption and precisely determine the length and polarity of individual microtubules. Observing the speed and extent of depolymerization (unraveling) of the spindle, the team worked backwards to compile a complete picture of the beginning and end points of each microtubule. Finally, additional experiments and a numerical model confirmed the role of transport.“The laser allowed us to make precise cuts and perform experiments that simply were not possible using previous techniques,” says Mazur.With further inquiries into spindle architecture, the researchers hope that scientists will one day have a complete understanding, and possibly even control over, the formation of the spindle.“Understanding the spindle means understanding cell division,” notes Brugués. “With a better understanding of how the spindle is supposed to operate, we have more hope of tackling the range of conditions — from cancer to birth defects — that result from disruptions to the cell cycle or from improper chromosomal segregation.”The research was supported by the National Science Foundation and by a fellowship from the Human Frontiers Science Program.For additional information, contact Caroline Perry at [email protected]
Notre Dame has been given a $25 million gift to establish the Lucy Family Institute for Data & Society, according to a University press release Friday.The institute will expand Notre Dame’s data-based academic programs and serve as “an interdisciplinary, university-wide hub that will connect faculty, students and research across existing data science and analytics programs on campus,” according to the release.University provost Tom Burish said the Lucy Family Institute will work with University’s existing data-driven academic and research programs to bring data science to a broader range of disciplines, including health, business and the social sciences. The institute will also be host to academic publications and conferences, and seek partnerships with outside entities.Alumnus Robert Lumpkins and his wife, Sara, who graduated from Saint Mary’s, donated the $25 million gift.“We are exceedingly grateful to Bob and Sara for their past generosity in helping Notre Dame keep pace with emerging trends in data science and business analytics,” University President Fr. John Jenkins said in the release. “With this latest gift, they have ensured that our undergraduate, graduate and professional students will wield the latest tools, knowledge and innovations to better society and the world.”The Lumpkins have previously helped fund endowed faculty positions, scholarships and business, science and mathematics programs.“We are pleased to support Notre Dame’s vision in this endeavor, which meshes with our values,” Sara and Bob Lumpkins said in the release. “We believe data science and analytics offer a powerful opportunity to enhance interdisciplinary collaboration and learning at the University, and that Notre Dame is uniquely positioned to bring an ethical perspective to its use for the good of society.”Tags: data analytics, data science, Lucy Family Institute, Lumpkins
ShareShareSharePrintMailGooglePinterestDiggRedditStumbleuponDeliciousBufferTumblr NCUA Chairman Rodney Hood continue reading » NCUA Chairman Rodney Hood Thursday called on the Financial Accounting Standards Board (FASB) to exempt credit unions from the current expected credit loss (CECL) standard. Since 2016, when the standard was issued, NAFCU has continuously urged FASB to exempt credit unions from the standard due to their unique capital framework and the negative impact the standard could have on the industry.“We applaud NCUA Chairman Rodney Hood for urging the Financial Accounting Standards Board to exempt credit unions from complying with FASB’s CECL standard,” said NAFCU President and CEO Dan Berger. “NAFCU has pushed hard for credit unions to be exempt from this onerous and costly accounting standard as it could place significant strains on credit unions’ capital levels, particularly amid the coronavirus pandemic.”NAFCU has worked closely with the NCUA to reduce CECL’s burden on the industry, most recently asking the agency to press FASB for more relief for credit unions in a discussion with NCUA Board Member J. Mark McWatters last week. NAFCU also reiterated its CECL concerns to Hood during a February meeting; NAFCU has consistently shared these concerns with Hood since he took office last year.
Sign up for our COVID-19 newsletter to stay up-to-date on the latest coronavirus news throughout New York State lawmakers joined Common Core opponents in criticizing President Barack Obama’s nomination of former New York State Education Commissioner John King for U.S. Secretary of Education in the first day of confirmation hearings Thursday.King, who assumed the role of acting commissioner in January, remains a lightning rod for fury among parents and teachers across New York State upset about his botched implementation of the controversial Common Core education reforms, which led to hundreds of thousands of students across the state and nation “opting out” of taking the standardized tests.Critics charge King’s previous tenure is proof he is incompetent and therefore unqualified for a higher office that carries nationwide responsibilities. “The bottom line is putting King as the Secretary of Education is basically perpetuating a flawed program that’s destructive to kids and destructive to schools,” NYS Assemb. Al Graf (R,C,I – Holbrook) tells the Press. “I would think that if they really want to fix education in this country, you want someone with experience in the classroom. And he doesn’t have that. He made a mess of New York, now you’re going to give him the opportunity to make a mess out of the rest of the country?”Graf accompanied fellow Long Island lawmakers Assemb. Ed Ra (R-Franklin Square), Assemb. Dave McDonough (R,C,I-Merrick) and Assemb. Dean Murray (R,C,I-East Patchogue) in issuing statements calling upon U.S. Sen. Kirsten Gillibrand and Sen. Charles Schumer to oppose the confirmation. “I am disappointed with the decision to nominate King as Arne Duncan’s successor, as it limits the opportunity to revitalize the future of our education system,” slammed Assemb. Ra, ranking minority member of the Assembly Committee on Education, in a press release. “We are encouraging our federal representatives to oppose King’s selection because he is simply not the visionary our students deserve. “In order to be successful in our efforts, we must keep our calls for appropriate educational standards, local control, and decreased reliance on mandated testing consistent at the state and federal levels,” he continued.Despite the bashing, King, who grew up in Brooklyn and whose parents were lifelong public school educators, credited education with saving his life during testimony before the U.S. Senate Education Committee Thursday. “I’m mindful of how remarkable it is that I am here at all,” he told federal lawmakers. “Some of you may know, I believe education is the difference between hope and despair, between life and death even, because it was for me.”Describing a “scary and unpredictable” home life following the death of his mother when he was 8 years old and the loss of his father to undiagnosed Alzheimer’s disease just four years later, King stated:“Amidst that trauma and uncertainty, school was my refuge and teachers were my saviors.” His personal battles aside, King remains within the crosshairs of local anti-Common Core advocates, among them, the Patchogue-Medford School District went so far as to adopt a resolution opposing his nomination, with its Board of Education declaring: “We cannot help but conclude that amplifying Dr. King’s abject failure as the leader of the educational establishment in New York State to the federal level is good for no one.”The resolution put forth a recommendation stipulating that “the President of the United States nominate, for our nation, a Secretary of Education who is proven leader in education, who has extensive public school experience, and proven success, as a both a teacher and administrator, who will be responsive to others, while being empathetic to the realistic needs of our nation’s students and working with the educational community.”Patchogue-Medford Superintendent Michael Hynes tells the Press via Facebook: “In his short tenure as the Commissioner of Education, John King has done more damage to the children in the state of NY then the past five commissioners combined.”In a feature report titled “John King: More of the Same or Worse” for the education advocacy nonprofit Network for Public Education, Executive Director Carol Burris (former principal of Rockville Centre’s South Side High School) detailed King’s experience leading up to this nomination, describing King as an inadequate leader who oversaw disastrous education policy. Burris examines not only King’s lack of experience as a classroom educator, but within the realm of public education. His experience, it states, centered around only private and charter schools for a total of three years before taking a position as managing director of the Uncommon Schools chain of charter schools. Burris describes King as “inflexible” and “quick to criticize” those who opposed his views while education commissioner. Under his tenure, the “opt-out” movement in New York grew such that an estimated 240,000 students refused the tests, and 625,000 nationwide, according to nonprofit The National Center for Fair and Open Testing. Burris also criticizes King’s decision to “stay the course” after it was apparent that the Common Core initiative was riddled with flaws that invalidated the efforts of the education community and discouraged thousands of educators, students, and parents throughout the state.“The 2013 Common Core tests were a disaster,” Burris writes. “The setting of unreasonably high proficiency cut scores, the length of the tests, and confusing and overly difficult questions caused both scores and parent confidence to plummet. “Principals reported young children in tears, becoming physically ill,” she adds. “The 2014 tests were a rerun of the previous year, and the achievement gap and the Opt Out movement grew. In 2014, the New York State United Teachers called for John King’s resignation.”