Scientists conducting deep-sea research in the Galapagos have described a new species of catshark. The new shark is approximately a foot long and has a chocolate-brown coloration with pale, irregularly distributed spots on its body. The spotted patterns appear to be unique to each individual.

The post New species of deep-sea catshark described from the Galapagos appeared first on Smithsonian Insider.

Smithsonian Conservation Biology Institute scientists and collaborators have found that the island scrub-jay’s population on Santa Cruz Island—its only habitat—is significantly smaller than previously believed […]

The post New count reveals scrub-jay on Santa Cruz Island is among rarest bird species in the U.S. appeared first on Smithsonian Insider.

David Guerit, Pauline Marie, Anne Morel, Justine Maurin, Christel Verollet, Brigitte Raynaud-Messina, Serge Urbach, and Anne Blangy

Among hematopoietic cells, osteoclasts (Oc) and immature dendritic cells (Dc) are closely related myeloid cells with distinct functions; Oc participate skeleton maintenance while Dc sample the environment for foreign antigens. Such specificities rely on profound modifications of gene and protein expression during Oc and Dc differentiation. We provide global proteomic and transcriptomic analyses of primary mouse Oc and Dc, based on original SILAC and RNAseq data. We established specific signatures for Oc and Dc including genes and proteins of unknown functions. In particular, we showed that Oc and Dc have the same α and β tubulin isotypes repertoire but that Oc express much more β tubulin isotype Tubb6. In both mouse and human Oc, we demonstrate that elevated expression of Tubb6 in Oc is necessary for correct podosomes organization and thus for the structure of the sealing zone, which sustains the bone resorption apparatus. Hence, lowering Tubb6 expression hindered Oc resorption activity. Overall, we highlight here potential new regulators of Oc and Dc biology and illustrate the functional importance of the tubulin isotype repertoire in the biology of differentiated cells.

Björn Eismann, Teresa G. Krieger, Jürgen Beneke, Ruben Bulkescher, Lukas Adam, Holger Erfle, Carl Herrmann, Roland Eils, and Christian Conrad

3D cell cultures enable the in vitro study of dynamic biological processes such as the cell cycle, but their use in high-throughput screens remains impractical with conventional fluorescent microscopy. Here, we present a screening workflow for the automated evaluation of mitotic phenotypes in 3D cell cultures by light-sheet microscopy. After sample preparation by a liquid handling robot, cell spheroids are imaged for 24 hours in toto with a dual-view inverted selective plane illumination microscope (diSPIM) with a much improved signal-to-noise ratio, higher imaging speed, isotropic resolution and reduced light exposure compared to a spinning disc confocal microscope. A dedicated high-content image processing pipeline implements convolutional neural network based phenotype classification. We illustrate the potential of our approach by siRNA knock-down and epigenetic modification of 28 mitotic target genes for assessing their phenotypic role in mitosis. By rendering light-sheet microscopy operational for high-throughput screening applications, this workflow enables target gene characterization or drug candidate evaluation in tissue-like 3D cell culture models.

Mei Wang, Luping Yu, Shu Wang, Fan Yang, Min Wang, Lufan Li, and Xin Wu

RNA-binding protein LIN28A is required for maintaining tissue homeostasis, including the reproductive system, but the underlying mechanisms on how LIN28A regulates germline progenitors remain unclear. Here, we dissected LIN28A-binding targets using high-throughput sequencing of RNAs isolated by crosslinking immunoprecipitation (HITS-CLIP) in the mouse testes. LIN28A preferentially binds to CDS or 3'UTR regions through these sites with GGAG(A) sequences enriched within mRNAs. Further investigation of Lin28a null mouse testes indicated that meiosis-associated mRNAs mediated by LIN28A were differentially expressed. Next, ribosome profiling revealed that the mRNA levels of these targets were significantly reduced in polysome fractions, and their protein expression levels decreased in the Lin28a null mouse testes, even when meiotic arrest in null mouse testes was not apparent. Collectively, these findings provide a set of binding targets that are regulated by LIN28A, which may potentially be the mechanism for the prominent role of LIN28A in regulating mammalian undifferentiated spermatogonia fates and male fertility.

Stephen Kershaw, David J. Morgan, James Boyd, David G. Spiller, Gareth Kitchen, Egor Zindy, Mudassar Iqbal, Magnus Rattray, Chris M. Sanderson, Andrew Brass, Claus Jorgensen, Tracy Hussell, Laura C. Matthews, and David W. Ray

Glucocorticoids (GCs) act through the glucocorticoid receptor (GR) to regulate immunity, energy metabolism, and tissue repair. Upon ligand binding, activated GR mediates cellular effects by regulating gene expression, but some GR effects can occur rapidly without new transcription. We show GCs rapidly inhibit cell migration, in response to both GR agonist and antagonist ligand binding. The inhibitory effect on migration is prevented by GR knockdown with siRNA, confirming GR specificity, but not by actinomycin D treatment, suggesting a non-transcriptional mechanism. We identified a rapid onset increase in microtubule polymerisation following glucocorticoid treatment, identifying cytoskeletal stabilisation as the likely mechanism of action. HDAC6 overexpression, but not knockdown of αTAT1, rescued the GC effect, implicating HDAC6 as the GR effector. Consistent with this hypothesis, ligand-dependent cytoplasmic interaction between GR and HDAC6 was demonstrated by quantitative imaging. Taken together, we propose that activated GR inhibits HDAC6 function and thereby increases the stability of the microtubule network to reduce cell motility. We therefore report a novel, non-transcriptional mechanism whereby GCs impair cell motility through inhibition of HDAC6 and rapid reorganization of the cell architecture.

A new approach is presented to obtain candidate structures from atomic pair distribution function (PDF) data in a highly automated way. It fetches, from web-based structural databases, all the structures meeting the experimenter's search criteria and performs structure refinements on them without human intervention. It supports both X-ray and neutron PDFs. Tests on various material systems show the effectiveness and robustness of the algorithm in finding the correct atomic crystal structure. It works on crystalline and nanocrystalline materials including complex oxide nanoparticles and nanowires, low-symmetry and locally distorted structures, and complicated doped and magnetic materials. This approach could greatly reduce the traditional structure searching work and enable the possibility of high-throughput real-time auto-analysis PDF experiments in the future.

The post Invasive Caribbean lionfish under scrutiny by Smithsonian Tropical Research Institute intern appeared first on Smithsonian Insider.

The post Pam Wintle, senior film archivist, describes the moving image collection of the Human Studies Film Archives appeared first on Smithsonian Insider.

Speeding Up Science from Facebook Stories on Vimeo. In January 2011, Oregon State University ichthyologist Brian Sidlauskas led a research expedition into the little-known Cuyuni […]

The post Facebook comes to rescue of ichythyologists struggling to describe specimens appeared first on Smithsonian Insider.

For the first time researchers from the Smithsonian, South Dakota State University and the University of Nebraska described the immature stages of the switchgrass moth, first collected in Denver in 1910.

The post Potential biofuel pest, the switchgrass moth, under renewed scrutiny of entomologists appeared first on Smithsonian Insider.

The crystal structure of vanthoffite, Na6Mg(SO4)4, was redetermined and refined with anisotropic displacement parameters for all atoms. Here, for the first time, we give its detailed description.

The crystal structure of vanthoffite {hexasodium magnesium tetrakis[sulfate(VI)]}, Na6Mg(SO4)4, was solved in the year 1964 on a synthetic sample [Fischer & Hellner (1964). Acta Cryst. 17, 1613]. Here we report a redetermination of its crystal structure on a mineral sample with improved precision. It was refined in the space group P21/c from a crystal originating from Surtsey, Iceland. The unique Mg (site symmetry overline{1}) and the two S atoms are in usual, only slightly distorted octahedral and tetrahedral coordinations, respectively. The three independent Na atoms are in a distorted octahedral coordination (1×) and distorted 7-coordinations intermediate between a `split octahedron' and a pentagonal bipyramid (2×). [MgO6] coordination polyhedra interchange with one half of the sulfate tetrahedra in <011> chains forming a (100) meshed layer, with dimers formed by edge-sharing [NaO7] polyhedra filling the interchain spaces. The other [NaO7] polyhedra are organized in a parallel layer formed by [010] and [001] chains united through edge sharing and bonds to the remaining half of sulfate groups and to [NaO6] octahedra. The two types of layers interconnect through tight bonding, which explains the lack of morphological characteristics typical of layered structures.

The application of groupoids to modular crystal structures is presented.

Structure-mining finds and returns the best-fit structures from structural databases given a measured pair distribution function data set. Using databases and heuristics for automation it has the potential to save experimenters a large amount of time as they explore candidate structures from the literature.

(The Paypers) Scrive, a Nordic e-sign and eID services provider, and

Björn Eismann
Apr 15, 2020; 0:jcs.245043v1-jcs.245043
TOOLS AND RESOURCES

To ensure that minority students who are poorly prepared for school are not assigned to special education for that reason, educators should be required to first provide them with high-quality instruction and social support in a general education classroom before making a determination that special education is needed.

The federal government should not rely on polygraph examinations for screening prospective or current employees to identify spies or other national-security risks because the test results are too inaccurate when used this way.

For severe acute pain due to surgeries and medical conditions, there is a lack of guidance on the appropriate type, strength, and amount of opioid medication that clinicians should prescribe to patients, says a new report from the National Academies of Sciences, Engineering, and Medicine.

President Trump has said he wants to see the country begin to reopen. The pandemic crashed the economy by keeping people at home, leading to millions of job losses.; Credit: Pool/Getty Images

The White House coronavirus task force rejected detailed guidance drafted by the Centers for Disease Control and Prevention on how workplaces ranging from schools to bars to churches should resume operations to prevent the spread of the virus because it was viewed as "overly prescriptive."

President Trump has said he wants to see the country begin to reopen. The pandemic crashed the economy by keeping people at home, leading to millions of job losses. The White House task force issued guidelines on how to gradually and safely reopen but left decisions up to governors based on conditions in their states.

Experts have warned that a rush to reopen could have disastrous implications for containing COVID-19. Many businesses have said they want more details about how to do things safely.

The draft detailed guidance was provided to the task force in late April, a couple of weeks after it released its April 16 guidance to states for reopening.

The task force sought "certain revisions" to the CDC's detailed guidance, two administration officials told NPR. But revised recommendations were never returned to the task force.

The Associated Press first reported on the task force decision to shelve the detailed guidance. Copies obtained and published by the AP, The New York Times and The Washington Post revealed detailed, staged directions for child care centers, schools, camps, restaurants and bars, churches and mass transit providers about how to safely resume operations.

"I think many people would argue that it is not the role of the federal government to tell specific entities — whether they be schools or churches or businesses — how they should go about doing things because the nation is so diverse," one of the administration officials said.

The task force said that some of the points may be helpful, but they needed to "zoom out a little bit and not be so prescriptive," according to the official. The task force said they would welcome a new set of recommendations, but that never happened, the official said.

"Issuing overly specific instructions — that CDC leadership never cleared — for how various types of businesses open up would be overly prescriptive and broad for the various circumstances states are experiencing throughout the country," the second administration official said. "Guidance in rural Tennessee shouldn't be the same guidance for urban New York City."

The United States last month reached 1 million known coronavirus cases, representing one-third of all coronavirus cases worldwide. Nearly 74,000 Americans have been felled by the disease as of Thursday, according to data compiled by the Johns Hopkins Coronavirus Resource Center.

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

A recent study has described a simple method to screen the toxicity of materials used in consumer products. Using utility meter products as examples, the study found, for example, that stainless steel and polyvinyl chloride (PVC) had high toxicity potentials and suggests less toxic, but equally effective and priced, alternatives that could be used instead.

Microsoft is now stating that they will fix mysterious and spontaneous cracks in Surface Laptop 3 displays as they may have been caused by a "foreign particle" introduced during manufacturing. [...]

Researchers from the University of Oxford's Bodleian Libraries and from universities in the Netherlands have used high-tech imaging to uncover the details of a rare Mexican codex dating from before the colonization of the Americas. The newly revealed codex, or book, has been hidden from view for almost 500 years, concealed beneath a layer of plaster and chalk on the back of a later manuscript known as the Codex Selden, which is housed at the Bodleian Libraries. Scientists have used hyperspectral imaging to reveal pictographic scenes from this remarkable document and have published their findings in the Journal of Archaeological Science: Reports.

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A new study suggests gaps exist in the treatment of depression with many individuals who screen positive for the mental health disorder not receiving treatment, according to an article published online by JAMA Internal Medicine.

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The risk of drought in the Norrström drainage basin, Sweden, increased during the 20th century, a new study has found. As the frequency of the dry periods increased, less water was available in the landscape for agriculture and for the resupply of groundwater — despite an increase in precipitation in the area over the same period. The researchers reached this conclusion after screening soil moisture conditions in the basin over the course of the century.

Flat screen televisions and computer monitors should be designed so they can be quickly dismantled for recycling, a recent study says. The researchers calculated that in order to ensure the recycling process remains economically viable, it must be possible to disassemble small screens in less than 11 minutes. Good design could lower the costs of recycling and enable near-total recovery of precious metals from the waste screens.

The potential of recycling aluminium scrap in Austria has been modelled in a new study. A surplus of mixed aluminium scrap is expected by 2045 if no advanced sorting technologies are applied. Increased demand for wrought aluminium alloys could mean this surplus occurs sooner. New methods to intensively sort aluminium could prevent this excess and contribute towards REACH1 recycling and climate targets.

A new screening tool to assess the potential seismic risks (earthquake activity) from deep geothermal energy projects has been outlined in a recent study. The tool provides categories of seismicity risk for projects, which are dependent on factors including geological aspects, as well as social concern and location in relation to urban areas.

5G will cover more than 20 percent of the global population six years from now, according to the latest Ericsson Mobility Report

A new study shows how titanium dioxide nanoparticles used in sunscreens may cause cancer in mice. Although there is no proof that the nanoparticles can cause cancer in humans, the researchers say the study raises concerns about the safety of workers exposed to high concentrations of the nanoparticles in factory settings.