Scott J. Neal, Qingxiang Zhou, and Francesca Pignoni

The specification of organs, tissues and cell types results from cell fate restrictions enacted by nuclear transcription factors under the control of conserved signaling pathways. The progenitor epithelium of the Drosophila compound eye, the eye imaginal disc, is a premier model for the study of such processes. Early in development, apposing cells of the eye disc are established as either retinal progenitors or support cells of the peripodial epithelium (PE), in a process whose genetic and mechanistic determinants are poorly understood. We have identified Protein Phosphatase 2A (PP2A), and specifically a STRIPAK-PP2A complex that includes the scaffolding and substrate-specificity components Cka, Strip and SLMAP, as a critical player in the retina-PE fate choice. We show that these factors suppress ectopic retina formation in the presumptive PE and do so via the Hippo signaling axis. STRIPAK-PP2A negatively regulates Hpo kinase, and consequently its substrate Wts, to release the transcriptional co-activator Yki into the nucleus. Thus, a modular higher-order PP2A complex refines the activity of this general phosphatase to act in a precise specification of cell fate.

Xian Hu, Salma Jalal, Michael Sheetz, Oddmund Bakke, and Felix Margadant

Despite progress made in confocal microscopy, even fast systems still have insufficient temporal resolution for detailed live cell volume imaging, such as tracking rapid movement of membrane vesicles in three-dimensional space. Depending on the shortfall, this may result in undersampling and/or motion artifacts that ultimately limit the quality of the imaging data. By sacrificing detailed information in the Z-direction, we propose a new imaging modality that involves capturing fast "projections" from the field of depth which shortens imaging time by approximately an order of magnitude as compared to standard volumetric confocal imaging. With faster imaging, radiation exposure to the sample is reduced, resulting in less fluorophore photobleaching and potential photodamage. The implementation minimally requires two synchronized control signals that drive a piezo stage and trigger the camera exposure. The device generating the signals has been tested on spinning disk confocals and instant structured-illumination-microscopy (iSIM) microscopes. Our calibration images show that the approach provides highly repeatable and stable imaging conditions that enable photometric measurements of the acquired data, in both standard live imaging and super-resolution modes.

If a supernova vaporized Earth’s ozone layer, what would happen to life in the ocean? Smithsonian biologist Pat Neale shows how UV rays could harm […]

The post If a supernova vaporized our ozone layer, what would happen to life on Earth? appeared first on Smithsonian Insider.

Smithsonian staff gathered on Thursday, June 1 outside the National Museum of African American History and Culture to show their support and listen to Director […]

The post Smithsonian staff rally to support African American History Museum after noose incident appeared first on Smithsonian Insider.

The Windows Defender Browser Protection tech support scam is a fake web site alert that states that Windows Defender Browser Extension detected someone to hack your bank account.

This article was published first at Remove the Windows Defender Browser Protection Tech Support Scam

It is one of the rarest shrubs in the southeastern United States but for scientists trying to save it, the critically endangered Michaux’s sumac (Rhus michauxii) is not cooperating.

The post Super tough seed coat keeps Michaux’s sumac on critically endangered list appeared first on Smithsonian Insider.

Celo, a competing project to...

File photo: LAUSD Superintendent Ramon Cortines faces a suit brought by a school district employee, who has sued him twice before.; Credit: David McNew/Getty Images

A Los Angeles Unified School District employee filed suit Wednesday accusing Superintendent Ramon Cortines of sexual harassment and retaliation, and alleging officials failed to intervene when told of the situation.

The lawsuit is the third one filed by Scot Graham, LAUSD's real estate director, who has made similar charges in previous complaints. The suit was filed in Los Angeles County Superior Court.

LAUSD General Counsel David Holmquist issued a statement Tuesday saying the courts have previously ruled on the case and the district is not aware of any new charges. "This is simply a frivolous refiling of the same allegations," he stated.

The latest suit alleges Cortines made sexual advances to Graham in 2000 soon after Cortines helped Graham get a job with the school district’s real estate leasing operations. Cortines left the school district that same year and Graham didn’t report what allegedly happened, according to the suit.

Graham claims that Cortines made additional sexual advances in 2010, the year the school board hired Cortines a second time to run the school district. The sexual advances were made at Cortines’ second home in Kern County, the suit alleges.

“Cortines’ advance shocked and disturbed Graham, who feared that declining Cortines’ request for sex would lead to unwarranted retaliatory consequences,” according to the lawsuit.

Graham said he notified his boss John Creer, and his boss’ boss James Sohn, but the school district conducted no investigation. Then in an October 2010 meeting, the suit claims General Counsel Holmquist “discouraged Graham from pursuing his claims, and suggested, in an intimidating and patronizing manner, that the incidents at the Ranch and Cortines’ unsolicited phone call were better left unreported.”

In May 2012, the district announced that it would pay $200,000 to Graham to settle his sexual harassment claims against Cortines, who by then had left the post. In the announcement, the district said Cortines denied sexually harassing Graham, but acknowledged they had a consensual relationship.

Graham later declined to sign off on the settlement. He filed one lawsuit in 2013 that was dismissed on a legal technicality and then a second one that was withdrawn in May 2014.

Five months later, the LAUSD school board rehired Cortines as an interim superintendent after the resignation of his predecessor, John Deasy. Cortines is expected to serve until a permanent replacement is chosen by the board later this year.

“What makes this different and new is the school board has rehired Ramon Cortines despite documented history of sexual harassment and sexual assault against Scot Graham,” said Rob Hennig, Graham’s lawyer.

By failing to investigate whether there was any merit to Graham’s allegations, the lawsuit argues, the school district failed in its duty to protect an employee from potential sexual harassment.

“Cortines shouldn’t have been rehired by the school board,” Hennig said.

In his statement, Holmquist said the district intends to "seek reimbursement for the taxpayers' dollars that are having to be expended in attorney's fees and costs" in dealing with Graham's allegations. The district said it spent about $240,000 defending itself against Graham's first two lawsuits.

Graham said in an interview Tuesday that he has been on leave since late last year because he’s developed a type of seizure disorder that prevents him from driving long distances.

He said he filed the latest lawsuit after the school board rehired Cortines and he was running into him in the workplace. Graham also said he felt his allegations were swept under the rug.

“No one came to talk to me…it was like being in a fraternity house,” he said.

The suit does not say how much in damages Graham is seeking, but it asks among other items for back pay, future pay, benefits, and compensation for medical treatment. It also seeks an investigation into Graham's accusations against the superintendent.

This content is from Southern California Public Radio. View the original story at SCPR.org.

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Bridges make travel faster and more convenient, but, in an earthquake, these structures are subject to forces that can cause extensive damage and make them unsafe. Now civil and environmental engineer Petros Sideris of Texas A&M University is leading a National Science Foundation (NSF)-funded research project to investigate the performance of hybrid sliding-rocking (HSR) columns. HSR columns provide the same support as conventional bridge infrastructure columns but are more earthquake-resistant. HSR columns are a series of individual concrete segments held together by steel cables that allow for controlled sliding and rocking. This allows the columns to shift without damage, while post-tensioning strands ensure that at the end of an earthquake the columns are pushed back to their original position. Conventional bridges are cast-in-place monolithic concrete elements that are strong but inflexible. Structural damage in these bridge columns, typically caused by a natural disaster, often forces a bridge to close until repairs are completed. But bridges with HSR columns can withstand large earthquakes with minimal damage and require minor repairs, likely without bridge closures. Such infrastructure helps with post-disaster response and recovery and can save thousands in taxpayer dollars. In an earthquake, HSR columns provide "multiple advantages to the public," Sideris said. "By preventing bridge damage, we can maintain access to affected areas immediately after an event for response teams to be easily deployed, and help affected communities recover faster. In mitigating losses related to post-event bridge repairs and bridge closures, more funds can be potentially directed to supporting the recovery of the affected communities." According to Joy Pauschke, NSF program director for natural hazards engineering, "NSF invests in fundamental engineering research so that, in the future, the nation's infrastructure can be more resilient to earthquakes, hurricanes, and other forces of nature."

Image credit: Texas A&M University

Outdated food safety laws and a fragmented federal structure serve as barriers to improving protection of the nations food supply from contamination or other hazards, according to Ensuring Safe Food From Production to Consumption.

Representatives from academies and research organizations around the world sent messages of condolence and support to members, officials and staff of the U.S. National Academies in the wake of terrorist attacks on the World Trade Center and the Pentagon. The following are excerpts from some of these messages.

Scientific evidence links mold and other factors related to damp conditions in homes and buildings to asthma symptoms in some people with the chronic disorder, as well as to coughing, wheezing, and upper respiratory tract symptoms in otherwise healthy people, says a new report from the Institute of Medicine of the National Academies.

The National Academy of Sciences (NAS) and Institute of Medicine (IOM) today released SCIENCE, EVOLUTION, AND CREATIONISM, a book designed to give the public a comprehensive and up-to-date picture of the current scientific understanding of evolution and its importance in the science classroom.

A congressionally mandated report from the National Research Council finds serious deficiencies in the nations forensic science system and calls for major reforms and new research.

Young athletes in the U.S. face a culture of resistance to reporting when they might have a concussion and to complying with treatment plans.

U.S. adults perform comparably to adults in other economically developed countries on most measures of science knowledge and support science in general, says a new report from the National Academies of Sciences, Engineering, and Medicine.

A new report from the National Academies of Sciences, Engineering, and Medicine urges Congress, federal and state agencies, and regulatory institutions to significantly increase their support for innovation for what the report’s study committee calls “increasingly clean” electric power technologies – nuclear power, carbon capture and storage, and renewables such as solar and wind. Some of these technologies have seen recent cost and price declines and are cost-competitive in certain locations.

The demand for family caregivers for adults who are 65 or older is increasing significantly, and family caregivers need more recognition, information, and support to fulfill their responsibilities and maintain their own health, financial security, and well-being, says a new report from the National Academies of Sciences, Engineering, and Medicine.

Cognitive training, blood pressure management for people with hypertension, and increased physical activity all show modest but inconclusive evidence that they can help prevent cognitive decline and dementia, but there is insufficient evidence to support a public health campaign encouraging their adoption, says a new report from the National Academies of Sciences, Engineering, and Medicine.

While the U.S. Department of Veterans Affairs (VA) provides mental health care of comparable or superior quality to care provided in private and non-VA public sectors, accessibility and quality of services vary across the VA health system, leaving a substantial unmet need for mental health services among veterans of the recent wars in Afghanistan and Iraq, says a new congressionally mandated report from the National Academies of Sciences, Engineering, and Medicine.

A new report from the National Academies of Sciences, Engineering, and Medicine examines evidence on whether providing permanent supportive housing (PSH) – a combination of stable housing and supportive services -- to individuals who are experiencing homelessness improves their health.