The true identity of the protein found in the crystals reported by Bondoc et al. [(2019), Acta Cryst. F75, 646–651] is given.

Scientists from the Smithsonian Museum Conservation Institute, the University of Valencia in Spain and the University of Minnesota, recently made an important observation regarding charcoals […]

The post Fungi still visible in wood charcoal centuries after burning appeared first on Smithsonian Insider.

A roundup of recent articles featuring spiders, bats and rats....

The post A Halloween roundup featuring recent articles on spiders, bats and rats appeared first on Smithsonian Insider.

The new research reveals that from the period between 1100-1600 small agricultural settlements up and down the Delaware River Valley caused a 50-percent increase in sediment runoff into the Delaware River.

The post Study reveals environmental impact of American Indian farms centuries before Europeans arrived in North America appeared first on Smithsonian Insider.

The impact of industrial fishing on coastal ecosystems has been studied for many years. But how it affects food webs in the open ocean―a vast […]

The post Scientists find impact of open-ocean industrial fishing within centuries of bird bones appeared first on Smithsonian Insider.

Studies show that on average, the weight of cremated remains for men is about 7.13 pounds (plus or minus 1.2 pounds) and for women, 4.9 […]

The post Hi-Tech Analysis Cracks Curious Case of Contaminated Cremains appeared first on Smithsonian Insider.

For the first time, researchers at the Smithsonian Conservation Biology Institute’s Migratory Bird Center have accurately tracked small migratory ovenbirds (Seiurus aurocapilla) to their tropical […]

The post Miniaturized GPS Tags Allow Tracking of Small Songbirds for first time appeared first on Smithsonian Insider.

In August astronomers announced that the nearby star Proxima Centauri hosts an Earth-sized planet (called Proxima b) in its habitable zone. At first glance, Proxima […]

The post Proxima Centauri Might Be More Sunlike Than We Thought appeared first on Smithsonian Insider.

A one-cubic-foot approach to studying biodiversity as showcased in the new Biocube exhibit at the Smithsonian’s National Museum of Natural History has led to the […]

The post New parasitic crab species discovered during Smithsonian Biocube work in Solomon Islands appeared first on Smithsonian Insider.

Eric Peterman, Mindaugas Valius, and Rytis Prekeris

During mitotic cell division, the actomyosin cytoskeleton undergoes several dynamic changes that play key roles in progression through mitosis. While the regulators of cytokinetic ring formation and contraction are well-established, proteins that regulate cortical stability during anaphase and telophase have been understudied. Here, we describe a role for CLIC4 in regulating actin and actin-regulators at the cortex and cytokinetic cleavage furrow during cytokinesis. We first describe CLIC4 as a new component of the cytokinetic cleavage furrow that is required for successful completion of mitotic cell division. We also demonstrate that CLIC4 regulates the remodeling of sub-plasma membrane actomyosin network within the furrow by recruiting MST4 kinase and regulating ezrin phosphorylation. This work identifies and characterizes new molecular players involved in regulating cortex stiffness and blebbing during late stages of cytokinetic furrowing.

Yung-An Huang, Chih-Hsuan Hsu, Ho-Chieh Chiu, Pei-Yu Hsi, Chris T. Ho, Wei-Lun Lo, and Eric Hwang

Microtubule (MT) is the most abundant cytoskeleton in neurons and controls multiple facets of their development. While the MT-organizing center (MTOC) in mitotic cells is typically located at the centrosome, MTOC in neurons switches to non-centrosomal sites. A handful of cellular components have been shown to promote non-centrosomal MT (ncMT) formation in neurons, yet the regulation mechanism remains unknown. Here we demonstrate that the small GTPase Ran is a key regulator of ncMTs in neurons. Using an optogenetic tool that enables light-induced local production of RanGTP, we demonstrate that RanGTP promotes ncMT plus-end growth along the neurite. Additionally, we discovered that actin waves drive the anterograde transport of RanGTP. Pharmacological disruption of actin waves abolishes the enrichment of RanGTP and reduces growing ncMT plus-ends at the neurite tip. These observations identify a novel regulation mechanism of ncMTs and pinpoint an indirect connection between the actin and MT cytoskeletons in neurons.

Karolina Losenkova, Mariachiara Zuccarini, Marika Karikoski, Juha Laurila, Detlev Boison, Sirpa Jalkanen, and Gennady G. Yegutkin

Extracellular adenosine mediates diverse anti-inflammatory, angiogenic and vasoactive effects and becomes an important therapeutic target for cancer, which has been translated into clinical trials. This study was designed to comprehensively assess adenosine metabolism in prostate and breast cancer cells. We identified cellular adenosine turnover as a complex cascade, comprised of (a) the ectoenzymatic breakdown of ATP via sequential nucleotide pyrophosphatase/phosphodiesterase-1, ecto-5’-nucleotidase/CD73 and adenosine deaminase reactions, and ATP re-synthesis through counteracting adenylate kinase and nucleoside diphosphokinase; (b) the uptake of nucleotide-derived adenosine via equilibrative nucleoside transporters; and (c) the intracellular adenosine phosphorylation into ATP by adenosine kinase and other nucleotide kinases. The exposure of cancer cells to 1% O₂ for 24 hours triggered ~2-fold up-regulation of CD73, without affecting nucleoside transporters, adenosine kinase activity and cellular ATP content. The ability of adenosine to inhibit the tumor-initiating potential of breast cancer cells via receptor-independent mechanism was confirmed in vivo using a xenograft mouse model. The existence of redundant pathways controlling extracellular and intracellular adenosine provides a sufficient justification for reexamination of the current concepts of cellular purine homeostasis and signaling in cancer.

Aparna Sherlekar, Gayatri Mundhe, Prachi Richa, Bipasha Dey, Swati Sharma, and Richa Rikhy

Branched actin networks driven by Arp2/3 collaborate with actomyosin filaments in processes such as cell migration. The syncytial Drosophila blastoderm embryo also shows expansion of apical caps by Arp2/3 driven actin polymerization in interphase and buckling at contact edges by MyosinII to form furrows in metaphase. Here we study the role of Syndapin (Synd), an F-BAR domain containing protein in apical cap remodelling prior to furrow extension. synd depletion showed larger apical caps. STED super-resolution and TIRF microscopy showed long apical actin protrusions in caps in interphase and short protrusions in metaphase in control embryos. synd depletion led to sustained long protrusions even in metaphase. Loss of Arp2/3 function in synd mutants partly reverted defects in apical cap expansion and protrusion remodelling. MyosinII levels were decreased in synd mutants and MyosinII mutant embryos have been previously reported to have expanded caps. We propose that Syndapin function limits branching activity during cap expansion and affects MyosinII distribution in order to shift actin remodeling from apical cap expansion to favor lateral furrow extension.

Julian Chollet, Alexander Dünkler, Anne Bäuerle, Laura Vivero-Pol, Medhanie A. Mulaw, Thomas Gronemeyer, and Nils Johnsson

Yeast cells select the position of their new bud at the beginning of each cell cycle. The recruitment of the septins to this prospective bud site is one of the critical events in a complex assembly pathway that culminates in the outgrowth of a new daughter cell. Hereby, the septin-rods follow the high concentration of Cdc42_GTP that is generated by the focused localization of its GEF Cdc24. We show that shortly before budding Cdc24 not only activates Cdc42 but also transiently interacts with Cdc11, the septin subunit that caps both ends of the septin rods. Mutations in Cdc24 reducing the affinity to Cdc11 impair septin recruitment and decrease the stability of the polarity patch. The interaction between septins and Cdc24 thus reinforces bud assembly at sites where septin structures are formed. Once the septins polymerize into the ring, Cdc24 is found at the cortex of the bud and directs its further outgrowth from this position.

Forensic anthropologists from the Smithsonian's National Museum of Natural History discover African remains at a Colonial burial site in Maryland. Follow them as they study the remains, reconstruct the face and body, and share what they learn about the African experience in the Chesapeake in the 1600s.

The post Smithsonian team examines African remains from a colonial burial site in Maryland appeared first on Smithsonian Insider.

Meet the Smithsonian's Matthew Carrano, curator of Dinosauria at the Smithsonian's National Museum of Natural History in Washington, D.C. Matthew studies all things dinosaur, but focuses on the evolutionary history of predatory (meat eating) dinosaurs.

The post Meet Our Scientist: Matthew Carrano, curator of dinosauria at the Smithsonian’s National Museum of Natural History appeared first on Smithsonian Insider.

The post Short video featuring the fieldwork of Smithsonian scientists created in 2000, posted by the Smithsonian Archives appeared first on Smithsonian Insider.

What is the average blood pressure of a geriatric sloth bear? Asia Trail keeper Stacey Tabellario is hoping to learn exactly that, as she trains […]

The post Measuring Sloth Bear Blood Pressure appeared first on Smithsonian Insider.

The Smithsonian Deep Reef Observation Project (DROP) captures a new species of deep-reef fish, the Godzilla goby, using the Curasub submersible. The lead scientist on […]

The post Capturing a new species with a submersible appeared first on Smithsonian Insider.

This new research has revealed that in areas considered unsuitable for farming today, "pre-Columbian farmers constructed thousands of raised fields in the seasonally flooded coastal savannas of the Guianas.

The post Amazon farmers who vanished centuries ago were remarkably innovative appeared first on Smithsonian Insider.

Nearly 60 million years ago rainforests prospered at temperatures that were 3-5 degrees higher and at atmospheric carbon dioxide levels 2.5 times today’s levels.

The post Plant diversity in tropical forests increased during ancient global warming event appeared first on Smithsonian Insider.

In a study published Sept. 28 in the journal Nature Plants, a team led by Smithsonian Conservation Biology Institute scientists found that bigger trees suffer […]

The post Forest Giants Suffer Most During Droughts appeared first on Smithsonian Insider.

Living trees can rot from the inside out, leaving only a hollowed trunk. Wood rot in living trees can cause overestimates of global carbon pools, […]

The post Measuring trees with the speed of sound appeared first on Smithsonian Insider.

According to a new study by biologists at the Smithsonian Migratory Bird Center and Virginia Tech the offspring of a certain songbird, the wood thrush, […]

The post Study: Large shady forest plots essential to survival of post-fledgling songbirds during drought appeared first on Smithsonian Insider.

This work presents a technique for extracting the detailed shape of peaks with extended, overlapping tails in an X-ray powder diffraction pattern. The application discussed here concerns crystallite size broadening, though the technique can be applied to spectra of any origin and without regard to how the profiles are to be subsequently analyzed. Historically, the extraction of profile shapes has been difficult due to the complexity of determining the background under the peak, resulting in an offset of the low-frequency components of the Fourier transform of the peak known as the `hook' problem. The use of a carefully considered statistical weighting function in a non-linear least-squares fit, followed by summing the residuals from such a fit with the fit itself, allows one to extract the full shape of an isolated peak, without contributions from either the background or adjacent peaks. The extracted shape, consisting of the fit function recombined with the residuals, is not dependent on any specific shape model. The application of this to analysis of microstructure is performed independently of global parametric models, which would reduce the number of refined parameters; therefore the technique requires high-quality data to produce results of interest. The effectiveness of the technique is demonstrated by extraction of Fourier transforms of peaks from two sets of size-broadened materials with two differing pieces of equipment.

In certain scenarios, a Subsystem Reference block changes its position. It can happen during: 

1. Loading of top model which contains the Subsystem Reference block 
2. Synchronization of Subsystem Reference block's contents
3. Converting a subsystem to Subsystem Reference block 

Crystals of the rare earth metal polytelluride LaTe1.82(1), namely, lanthanum telluride (1/1.8), have been grown by molten alkali halide flux reactions and vapour-assisted crystallization with iodine. The two-dimensionally incommensurately modulated crystal structure has been investigated by X-ray diffraction experiments. In contrast to the tetra­gonal average structure with unit-cell dimensions of a = 4.4996 (5) and c = 9.179 (1) Å at 296 (1) K, which was solved and refined in the space group P4/nmm (No. 129), the satellite reflections are not compatible with a tetra­gonal symmetry but enforce a symmetry reduction. Possible space groups have been derived by group–subgroup relationships and by consideration of previous reports on similar rare earth metal polychalcogenide structures. Two structural models in the ortho­rhom­bic superspace group, i.e. Pmmn(α,β,1 over 2)000(−α,β,1 over 2)000 (No. 59.2.51.39) and Pm21n(α,β,1 over 2)000(−α,β,1 over 2)000 (No. 31.2.51.35), with modulation wave vectors q1 = αa* + βb* + 1 over 2c* and q2 = −αa* + βb* + 1 over 2c* [α = 0.272 (1) and β = 0.314 (1)], have been established and evaluated against each other. The modulation describes the distribution of defects in the planar [Te] layer, coupled to a displacive modulation due to the formation of different Te anions. The bonding situation in the planar [Te] layer and the different Te anion species have been investigated by density functional theory (DFT) methods and an electron localizability indicator (ELI-D)-based bonding analysis on three different approximants. The temperature-dependent electrical resistance revealed a semiconducting behaviour with an estimated band gap of 0.17 eV.

(The Paypers) Yoti has revealed a pair of partnerships to provide solutions combining its biometric technology...

(The Paypers) Menlo Security, a global enterprise cloud security provider, has entered the Australian...

(The Paypers) A new survey suggests the majority of Canadians remain worried about the security of their personal information online.

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.

Use of protective face coverings will be one of many strategies used to slow or prevent transmission of the flu virus in the event of a pandemic, even though scientific evidence about the effectiveness of inexpensive, disposable medical masks and respirators against influenza is limited.

Although most people who receive and manage Social Security benefits on behalf of other individuals perform their duties well.

Good morning. I am Dr. Alice Gast and I am here today with Dr. David Relman as the chair and vice chair of the Committee on the Review of the Scientific Approaches Used During the FBI’s Investigation of the 2001 Bacillus anthracis Mailings.