Size isn’t the only thing that’s small about the pygmy sloth―its population is too. But scientists at the Smithsonian say things may be looking up […]

The post Study reveals more Pygmy Sloths, But There Still Aren’t Many appeared first on Smithsonian Insider.

Tiny Anolis lizards preserved since the Miocene in amber are giving scientists a true appreciation of the meaning of community stability. Dating back some 15 […]

The post Trapped in Amber: Ancient fossils reveal remarkable stability of Caribbean lizard communities appeared first on Smithsonian Insider.

Since researchers began surveys in the 1980s, coral reefs in the Caribbean have undergone widespread change following bleaching and disease epidemics that have reduced the […]

The post Study reveals Agriculture and Fishing Cause Coral Reef Decline appeared first on Smithsonian Insider.

Recently crowned the “astronomy photo of the year” by Slate’s Bad Astronomy blog, a new image of a region of Orion’s belt reveals the deepest […]

The post Stunning deep space photo reveals new details of Orion nebulae appeared first on Smithsonian Insider.

Smithsonian scientists and colleagues have discovered a new genus and species of river dolphin that has long been extinct. They made the discovery after carefully […]

The post Fossil Specimen Reveals a New Species of Ancient River Dolphin appeared first on Smithsonian Insider.

New research by a team of archaeologists has revealed a curious connection between our traditional Thanksgiving dinner and the taste buds of prehistoric mammoths and […]

The post Study reveals ancient link between mammoth dung and pumpkin pie appeared first on Smithsonian Insider.

Most people think of black holes as giant vacuum cleaners sucking in everything that gets too close. But the supermassive black holes at the centers […]

The post Event Horizon Telescope Reveals Magnetic Fields at Milky Way’s Central Black Hole appeared first on Smithsonian Insider.

Through sheer coincidence, two Smithsonian researchers at the National Zoological Park have discovered that 18 percent of the white-tailed deer population in the Eastern United […]

The post Smithsonian study reveals white-tailed deer in eastern U.S. are infected with a malaria parasite appeared first on Smithsonian Insider.

Pop quiz! Name the first five dinosaurs that come to mind. Chances are good that one you named was Tyrannosaurs rex, a popular favorite perhaps best […]

The post New horse-sized tyrannosaur with big brain reveals how “T. rex” became top predator appeared first on Smithsonian Insider.

Nocturnal, solitary and fiercely territorial the adult Egyptian pigmy shrew—one of the smallest mammals on earth—weighs just 7 grams. French zoologist Isidore Geoffroy Saint-Hilaire first […]

The post Sacred shrew mummies reveal species distribution in ancient Egypt appeared first on Smithsonian Insider.

Astronomers announced today that they have found the organic molecule methyl alcohol, or methanol, in the TW Hydrae protoplanetary disk. This is the first such […]

The post Methanol reveals comets forming in distant solar system appeared first on Smithsonian Insider.

The planet’s last stronghold of wild cheetahs (Acinonyx jubatus) is losing genetic diversity at an alarming rate according to a new study from the Smithsonian […]

The post Smithsonian Study reveals Decline of Genetic Diversity in Wild Cheetahs appeared first on Smithsonian Insider.

Using new numerical simulations and observations, scientists may now be able to explain why the Sun’s magnetic field reverses every eleven years. This significant discovery […]

The post 3D simulations reveals why the Sun flips its magnetic field every 11 years appeared first on Smithsonian Insider.

Covered in sharp spines, when harassed the porcupine fish inflates like a balloon. Think of a small soccer ball bristling all over with nails. Most predators […]

The post Indestructible jaws from ancient, extinct porcupine fish reveal new species appeared first on Smithsonian Insider.

Plastic debris floating in the ocean has become a powerful new passport to far-away destinations for a wide variety of invasive species, according to new […]

The post Tsunami reveals drifting ocean plastic opens globe to invasive castaways appeared first on Smithsonian Insider.

The outer membrane of Gram-negative bacteria is highly impermeable to hydrophilic molecules of larger than 600 Da, protecting these bacteria from toxins present in the environment. In order to transport nutrients across this impermeable membrane, Gram-negative bacteria utilize a diverse family of outer-membrane proteins called TonB-dependent transporters. The majority of the members of this family transport iron-containing substrates. However, it is becoming increasingly clear that TonB-dependent transporters target chemically diverse substrates. In this work, the structure and phylogenetic distribution of the TonB-dependent transporter YncD are investigated. It is shown that while YncD is present in some enteropathogens, including Escherichia coli and Salmonella spp., it is also widespread in Gammaproteobacteria and Betaproteobacteria of environmental origin. The structure of YncD was determined, showing that despite a distant evolutionary relationship, it shares structural features with the ferric citrate transporter FecA, including a compact positively charged substrate-binding site. Despite these shared features, it is shown that YncD does not contribute to the growth of E. coli in pure culture under iron-limiting conditions or with ferric citrate as an iron source. Previous studies of transcriptional regulation in E. coli show that YncD is not induced under iron-limiting conditions and is unresponsive to the ferric uptake regulator (Fur). These observations, combined with the data presented here, suggest that YncD is not responsible for the transport of an iron-containing substrate.

The biological processes related to protein homeostasis in Mycobacterium tuberculosis, the etiologic agent of tuberculosis, have recently been established as critical pathways for therapeutic intervention. Proteins of particular interest are ClpC1 and the ClpC1–ClpP1–ClpP2 proteasome complex. The structure of the potent antituberculosis macrocyclic depsipeptide ecumicin complexed with the N-terminal domain of ClpC1 (ClpC1-NTD) is presented here. Crystals of the ClpC1-NTD–ecumicin complex were monoclinic (unit-cell parameters a = 80.0, b = 130.0, c = 112.0 Å, β = 90.07°; space group P21; 12 complexes per asymmetric unit) and diffracted to 2.5 Å resolution. The structure was solved by molecular replacement using the self-rotation function to resolve space-group ambiguities. The new structure of the ecumicin complex showed a unique 1:2 (target:ligand) stoichiometry exploiting the intramolecular dyad in the α-helical fold of the target N-terminal domain. The structure of the ecumicin complex unveiled extensive interactions in the uniquely extended N-terminus, a critical binding site for the known cyclopeptide complexes. This structure, in comparison with the previously reported rufomycin I complex, revealed unique features that could be relevant for understanding the mechanism of action of these potential antituberculosis drug leads. Comparison of the ecumicin complex and the ClpC1-NTD-L92S/L96P double-mutant structure with the available structures of rufomycin I and cyclomarin A complexes revealed a range of conformational changes available to this small N-terminal helical domain and the minor helical alterations involved in the antibiotic-resistance mechanism. The different modes of binding and structural alterations could be related to distinct modes of action.

Tidal Freshwater Wetlands focuses on wetlands found in North America and Europe near the mouths of rivers that flow into estuaries like the Chesapeake Bay.

The post New book reveals tidal freshwater wetlands are on frontlines of global change appeared first on Smithsonian Insider.

Some of the earliest humans to inhabit America came from Europe according to a new book "Across Atlantic Ice: The Origin of America's Clovis Culture."

The post New book reveals Ice Age mariners from Europe were America’s first inhabitants appeared first on Smithsonian Insider.

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.

Su Ming Sun, Amandine Batte, Mireille Tittel-Elmer, Sophie van der Horst, Tibor van Welsem, Gordon Bean, Trey Ideker, Fred van Leeuwen, and Haico van Attikum

Eukaryotic chromosomes are replicated in interphase and the two newly duplicated sister chromatids are held together by the cohesin complex and several cohesin auxiliary factors. Sister chromatid cohesion is essential for accurate chromosome segregation during mitosis, yet has also been implicated in other processes, including DNA damage repair, transcription and DNA replication. To assess how cohesin and associated factors functionally interconnect and coordinate with other cellular processes, we systematically mapped genetic interactions of 17 cohesin genes centered on quantitative growth measurements of >52,000 gene pairs in budding yeast. Integration of synthetic genetic interactions unveiled a cohesin functional map that constitutes 373 genetic interactions, revealing novel functional connections with post-replication repair, microtubule organization and protein folding. Accordingly, we show that the microtubule-associated protein Irc15 and the prefoldin complex members Gim3, Gim4 and Yke2 are new factors involved in sister chromatid cohesion. Our genetic interaction map thus provides a unique resource for further identification and functional interrogation of cohesin proteins. Since mutations in cohesin proteins have been associated with cohesinopathies and cancer, it may also identify cohesin interactions relevant in disease etiology.

M. Pinar and M. A. Penalva

TRAnsport Protein Particle (TRAPP) complexes regulate membrane traffic. TRAPPII and TRAPPIII share a core hetero-heptamer, also denoted TRAPPI. In fungi TRAPPIII and TRAPPII mediate GDP exchange on RAB1 and RAB11, respectively, regulating traffic across the Golgi, with TRAPPIII also activating RAB1 in autophagosomes. Our finding that Aspergillus nidulans TRAPPII can be assembled by addition of a TRAPPII-specific subcomplex onto core TRAPP prompted us to investigate the possibility that TRAPPI/TRAPPIII already residing in the Golgi matures into TRAPPII to determine a RAB1-to-RAB11 conversion as Golgi cisternae progress from early Golgi to TGN identity. By time-resolved microscopy we determine that the TRAPPII reporter Trs120/TRAPPC9 is recruited to existing TGN cisternae slightly before RAB11 arrives, and resides for~45 sec on them before cisternae tear off into RAB11 secretory carriers. Notably, the core TRAPP reporter Bet3/TRAPPC3 was not detectable in early Golgi cisternae, being instead recruited to TGN cisternae simultaneously with Trs120/TRAPPC9, indicating en bloc recruitment of TRAPPII to the Golgi and arguing strongly against the TRAPP maturation model.

New images from NASA's Lunar Reconnaissance Orbiter (LRO) spacecraft show the moon's crust is being stretched, forming minute valleys in a few small areas on the lunar surface.

The post Photos reveal recent activity in moon’s crust appeared first on Smithsonian Insider.

The humble salamander may provide evidence to support a controversial claim that North and South America were joined together much earlier than previously thought. The […]

The post Salamander DNA reveals evidence of older land connection between Central and South America appeared first on Smithsonian Insider.

Miniature camels and horses, a rhinoceros and a giant bear-dog are among fossils unearthed in the recent excavations of the Panama Canal expansion project. These […]

The post First five years of Panama Canal excavations reveal fossil finds appeared first on Smithsonian Insider.

The post How do we know if dinosaurs cared for their young? Smithsonian curator Matthew Carrano reveals the fossil evidence. appeared first on Smithsonian Insider.

Botanists Gerhard Zotz of the Smithsonian Tropical Research Institute and Stefan Wester of the University of Oldenburg in Germany decided to take a closer look at these high-wire bromeliads. They were interested to find out how the growth and survival rates of these plants on electrical cables compared to the growth and survival of plants of the same species growing in trees--their natural environment.

The post Study reveals hazards of the high-wire life for bromeliads appeared first on Smithsonian Insider.

Recent analysis using DNA sequencing of ancient Roman pills found aboard a ship that sank in Italy’s Gulf of Baratti between 140 -120 B.C, has revealed that the medicines consist of material from simple garden plants, namely carrot, radish, parsley, celery, wild onion and cabbage.

The post DNA sequencing reveals simple vegetables in ancient Roman medicines appeared first on Smithsonian Insider.

A 48 million-year-old fossilized leaf has revealed the oldest known evidence of a macabre part of nature – parasites taking control of their hosts to turn them into zombies.

The post Fossil reveals 48-million year history of zombie ants appeared first on Smithsonian Insider.

Despite many laws to protect it, a new survey reveals wild ginseng in Maryland is on the decline.

The post Wild ginseng in steep decline in Maryland, survey reveals: Q&A with Smithsonian botanist Christopher Puttock appeared first on Smithsonian Insider.

Going for the gut will soon become standard protocol for scientists working to unravel the complex living web of interactions between plants and animals on […]

The post Going for the gut: DNA from beetle stomachs reveals complex network appeared first on Smithsonian Insider.

For centuries untold numbers of this tiny arachnid (cousin to spiders and ticks) have ended up in teapots, invisibly steeping alongside the leaves of the tea plant on which it lives.

The post Primitive, bizarre, beautiful: New mite species reveal a lost world awaiting discovery appeared first on Smithsonian Insider.

Named for Charles Darwin, the only known specimen of a newly discovered beetle, Darwinylus marcosi, died in a sticky battle in a gob of tree […]

The post Beetle and pollen trapped in 105 million-year-old amber reveal fourth major pollination mode in mid-Mesozoic appeared first on Smithsonian Insider.

For the first time, a new public database will link genetic data with records of where and when the samples it was taken from were […]

The post A first: New website reveals origin of genetic samples and date collected appeared first on Smithsonian Insider.

How specific fungi interact with seeds in tropical forest soils may be the ultimate arbiter in the struggle for survival among tropical trees. “Depending on […]

The post Study reveals soil fungi has final say in survival of seeds from tropical trees appeared first on Smithsonian Insider.

Compared with X-rays, electron diffraction faces a crucial challenge: dynamical electron scattering compromises structure solution and its effects can only be modelled in specific cases. Dynamical scattering can be reduced experimentally by decreasing crystal size but not without a penalty, as it also reduces the overall diffracted intensity. In this article it is shown that nanometre-sized crystals from organic pharmaceuticals allow positional refinement of the hydrogen atoms, even whilst ignoring the effects of dynamical scattering during refinement. To boost the very weak diffraction data, a highly sensitive hybrid pixel detector was employed. A general likelihood-based computational approach was also introduced for further reducing the adverse effects of dynamic scattering, which significantly improved model accuracy, even for protein crystal data at substantially lower resolution.

(The Paypers) Forter has released the seventh edition of its Fraud Attack Index, tracking shifting behaviours...

Su Ming Sun
Apr 16, 2020; 0:jcs.237628v1-jcs.237628
Articles

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

The 2020 State of Disbursements: APAC Outlook Report by Rapyd...

A new large-scale, multidisciplinary ocean exploration program would increase the pace of discovery of new species - ecosystems, energy sources, seafloor features, pharmaceutical products, and artifacts, as well as improve understanding of the role oceans play in climate change.

The Institute of Medicine today presented the Gustav O. Lienhard Award to Linda Aiken, Claire M. Fagin Leadership Professor of Nursing at the University of Pennsylvania School of Nursing, for her rigorous research demonstrating the importance of nursing care and work environments in achieving safe, effective, patient-centered, and affordable health care.

The importance of coral reefs in supporting diverse fish communities has been highlighted in a recent study. However, the effects of damaging fishing techniques were also observed in video footage of the reefs studied, located off the coast of Ireland.

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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Phrases that combine 'carbon' with other words, such as 'carbon finance' or 'carbon footprint', can provide insight into how climate change issues are communicated. A new study explored online use of these so-called 'carbon compounds' and indicated that they form three clusters focused on finance, lifestyle and attitudes.

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.

Scientists have tested the behaviour of biodegradable plastics in managed composting and anaerobic conditions, as well as under simulated environmental conditions, such as in seawater or soil. This study found that blending different types of biodegradable plastics may open up new opportunities in relation to their end-of-life treatment — notably the potential to make one of the world’s best-selling biodegradable plastics, polyactic acid (PLA), home-compostable by blending it with another polymer (polycaprolactone — PCL). However, the researchers were also concerned that most materials tested could still cause plastic pollution as they failed to biodegrade sufficiently — and, in some cases, not at all, in particular, in soil and the marine environment.

Ever since the 1950s discovery of the solar wind - the constant flow of charged particles from the sun - there's been a stark disconnect between this outpouring and the sun itself. As it approaches Earth, the solar wind is gusty and turbulent. But near the sun where it originates, this wind is structured in distinct rays, much like a child's simple drawing of the sun. The details of the transition from defined rays in the corona, the sun's upper atmosphere, to the solar wind have been, until now, a mystery.

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