The new book Subsistence Economies of Indigenous North American Societies provides a comprehensive and in-depth documentation of how Native American societies met the challenges of […]

The post New book: “The Subsistence Economies of Indigenous North American Societies: A Handbook” appeared first on Smithsonian Insider.

Only the Wing is a new book by Russell Lee that recounts Horten's epic quest to stabalize and control the all-wing aircraft.

The post New Book: “Only the Wing: Reimar Horten’s Epic Quest to Stabilize and Control the All-Wing Aircraft” appeared first on Smithsonian Insider.

Despite the importance of seasonally dry forests, little is known of their ecology. Now, a new book The Ecology and Conservation of Seasonally Dry Forests in Asia, published by Smithsonian Institution Scholarly Press, explores these unique ecosystems, its animals, plants, and the people that inhabit them.

The post New book: The Ecology and Conservation of Seasonally Dry Forests in Asia appeared first on Smithsonian Insider.

Between the world wars of the early Twentieth Century, an age of adventure travel and cultural exploration flourished when newly developed transport and recording technologies–particularly […]

The post New Book: “Recreating First Contact: Expeditions, Anthropology, and Popular Culture” appeared first on Smithsonian Insider.

Osiris Martinez-Guzman, Mathilda M. Willoughby, Arushi Saini, Jonathan V. Dietz, Iryna Bohovych, Amy E. Medlock, Oleh Khalimonchuk, and Amit R. Reddi

Heme is a cofactor and signaling molecule that is essential for much of aerobic life. All heme-dependent processes in eukaryotes require that heme is trafficked from its site of synthesis in the mitochondria to hemoproteins located throughout the cell. However, the mechanisms governing the mobilization of heme out of the mitochondria, and the spatio-temporal dynamics of these processes, are poorly understood. Herein, using genetically encoded fluorescent heme sensors, we developed a live cell assay to monitor heme distribution dynamics between the mitochondrial inner-membrane, where heme is synthesized, and the mitochondrial matrix, cytosol, and nucleus. Surprisingly, heme trafficking to the nucleus is ~25% faster than to the cytosol or mitochondrial matrix, which are nearly identical, potentially supporting a role for heme as a mitochondrial-nuclear retrograde signal. Moreover, we discovered that the heme synthetic enzyme, 5-aminolevulinic acid synthase (ALAS), and GTPases in control of the mitochondrial dynamics machinery, Mgm1 and Dnm1, and ER contact sites, Gem1, regulate the flow of heme between the mitochondria and nucleus. Overall, our results indicate that there are parallel pathways for the distribution of bioavailable heme.

Aline A. Alves, Heloisa B. Gabriel, Maria J. R. Bezerra, Wanderley de Souza, Sue Vaughan, Narcisa L. Cunha-e-Silva, and Jack D. Sunter

Eukaryotic flagella are complex microtubule based organelles and in many organisms there are extra-axonemal structures present, including the outer dense fibres of mammalian sperm and the paraflagellar rod (PFR) of trypanosomes. Flagellum assembly is a complex process occurring across three main compartments, the cytoplasm, the transition fibre-transition zone, and the flagellum. It begins with translation of protein components, followed by their sorting and trafficking into the flagellum, transport to the assembly site and then incorporation. Flagella are formed from over 500 proteins; the principles governing axonemal component assembly are relatively clear. However, the coordination and sites of extra-axonemal structure assembly processes are less clear.

We have discovered two cytoplasmic proteins in T. brucei that are required for PFR formation, PFR assembly factors 1 and 2. Deletion of either PFR-AF1 or PFR-AF2 dramatically disrupted PFR formation and caused a reduction in the amount of major PFR proteins. The presence of cytoplasmic factors required for PFR formation aligns with the concept of processes occurring across multiple compartments to facilitate axoneme assembly and this is likely a common theme for extra-axonemal structure assembly.

Tara L. Mastro, Vishnu P. Tripathi, and Susan L. Forsburg

Translesion synthesis polymerases (TLSPs) are non-essential error-prone enzymes that ensure cell survival by facilitating DNA replication in the presence of DNA damage. In addition to their role in bypassing lesions, TLSPs have been implicated in meiotic double strand break repair in several systems. Here we examine the joint contribution of four TLS polymerases to meiotic progression in the fission yeast S. pombe. We observed the dramatic loss of spore viability in fission yeast lacking all four TLSPs which is accompanied by disruptions in chromosome segregation during meiosis I and II. Rec8 cohesin dynamics are altered in the absence of the TLSPs. These data suggest that the TLSPs contribute to multiple aspects of meiotic chromosome dynamics.

Juan Martin D'Ambrosio, Veronique Albanese, Nicolas-Frederic Lipp, Lucile Fleuriot, Delphine Debayle, Guillaume Drin, and Alenka Copic

Osh6 and Osh7 are lipid transfer proteins (LTPs) that move phosphatidylserine (PS) from the endoplasmic reticulum (ER) to the plasma membrane (PM). High PS level at the PM is key for many cellular functions. Intriguingly, Osh6/7 localize to ER-PM contact sites, although they lack membrane-targeting motifs, in contrast to multidomain LTPs that both bridge membranes and convey lipids. We show that Osh6 localization to contact sites depends on its interaction with the cytosolic tail of the ER-PM tether Ist2, a homologue of TMEM16 proteins. We identify a motif in the Ist2 tail, conserved in yeasts, as the Osh6-binding region, and we map an Ist2-binding surface on Osh6. Mutations in the Ist2 tail phenocopy osh6 osh7 deletion: they decrease cellular PS levels, and block PS transport to the PM. Our study unveils an unexpected partnership between a TMEM16-like protein and a soluble LTP, which together mediate lipid transport at contact sites.

Samantha-Su Z. Taylor, Nicole L. Jacobsen, Tasha K. Pontifex, Paul Langlais, and Janis M. Burt

Connexin 37 (Cx37) expression profoundly suppresses proliferation of rat insulinoma (Rin) cells in a manner dependent on gap junction channel (GJCh) functionality and the presence and phosphorylation status of its carboxyl-terminus (CT). In Rin cells growth arrested by induced Cx37 expression, serine 319 (S319) is frequently phosphorylated. Preventing phosphorylation at this site (alanine substitution; S319A) relieved Cx37 of its growth suppressive effect whereas mimicking phosphorylation at this site (aspartate substitution; S319D) enhanced Cx37's growth suppressive properties. Like Cx37-WT, -S319D GJChs and hemichannels (HChs) preferred the closed state, rarely opening fully, and gated slowly. In contrast, Cx37-S319A channels preferred open states, opened fully, and gated rapidly. These data indicate that phosphorylation-dependent conformational differences in Cx37 protein and channel function underlie Cx37-induced growth arrest vs. growth permissive phenotypes. That the closed state of -WT and Cx37-S319D GJChs and HChs favors growth arrest suggests that rather than specific permeants mediating cell cycle arrest, the closed conformation instead supports interaction of Cx37 with growth regulatory proteins that result in growth arrest.

The Smithsonian Research Online program recently surpassed the mark of 10,000 publications in the Digital Repository. This collection of digital publications by Smithsonian staff represents a broad review of research done by researchers at the Institution.

The post Smithsonian Digital Repository Now Contains 10,000 Items appeared first on Smithsonian Insider.

A mysterious cycle of booms and busts in marine biodiversity over the past 500 million years could be tied to a periodic uplifting of the world's continents, scientists report

The post Boom and bust cycle of marine biodiversity every 60 million years linked to uplifting of continents appeared first on Smithsonian Insider.

Recent airborne geophysical surveys near Decorah, Iowa are providing an unprecedented look at a 470-million-year-old meteorite crater concealed beneath bedrock and sediments. The aerial surveys, […]

The post Iowa meteorite crater confirmed 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.

Odile Madden knows a lot about plastic. A materials scientist with the Smithsonian Museum Conservation Institute, she has spent the past eight years studying plastics […]

The post Microplastics in our environment: A conversation with Odile Madden, Smithsonian plastics scientist appeared first on Smithsonian Insider.

Appendices B4 and B5 of Cayron [Acta Cryst. (2019), A75, 411–437] contain equations involving the point group and the metric tensor in which the equality symbol should be substituted by the inclusion symbol.

The transformations from the primitive cells of the centered Bravais lattices to the corresponding centered cells have conventionally been listed as three-by-three matrices that transform three-space lattice vectors. Using those three-by-three matrices when working in the six-dimensional space of lattices represented as Selling scalars as used in Delone (Delaunay) reduction, one could transform to the three-space representation, apply the three-by-three matrices and then back-transform to the six-space representation, but it is much simpler to have the equivalent six-by-six matrices and apply them directly. The general form of the transformation from the three-space matrix to the corresponding matrix operating on Selling scalars (expressed in space S6) is derived, and the particular S6matrices for the centered Delone types are listed. (Note: in his later publications, Boris Delaunay used the Russian version of his surname, Delone.)

The post Conservators challenged by contemporary artworks at the Hirshhorn Museum appeared first on Smithsonian Insider.

When animal care staff at the Smithsonian's National Zoo need to know when to breed their pandas or when to expect a cub they turn to the Endocrine (Hormones) Research Lab at the Zoo's Front Royal, Va. facility.

The post The science of panda cubs at the Smithsonian Conservation Biology Institute appeared first on Smithsonian Insider.

Dr. Mary Hagedorn, a marine biologist at the Smithsonian Institution, talks about her research to understand and conserve our oceans' corals. To meet more scientists, visit https://insider.si.edu.

The post Coral biologist Mary Hagedorn speaks about her research to conserve our ocean’s corals appeared first on Smithsonian Insider.

The post Many years of research are celebrated in the December 2010 birth of two cheetah cubs at the Smithsonian Conservation Biology Institute appeared first on Smithsonian Insider.

The post After a bulldozer unearthed five statues in Ain Ghazal, Jordan in 1984, Smithsonian conservators carefully restore these otherworldy figures appeared first on Smithsonian Insider.

Animal care staff at the Smithsonian Conservation Biology Institute in Front Royal, Virginia, are hand-rearing the pair of clouded leopard cubs born on March 28, increasing the chances that the cubs will be more successful at breeding later in their life.

The post Hand-rearing clouded leopard cubs at the Smithsonian Conservation Biology Institute appeared first on Smithsonian Insider.

Tom Crouch, Senior curator in the National Air and Space Museum's Aeronautics Division, discusses Thaddeus Lowe and the birth of American aerial reconnaissance during the Civil War. This presentation was recorded on May 11, 2011 on the National Mall.

The post Tom Crouch, Senior curator in the National Air and Space Museum’s Aeronautics Division, discusses Thaddeus Lowe and the birth of American aerial reconnaissance appeared first on Smithsonian Insider.

What's possibly the most calming yet nerve-racking job in the world? Come behind the scenes of the Smithsonian's Freer Gallery of Art to find out!

The post Zen and the art of fine art conservation: Behind the scenes in the Freer Gallery’s art conservation lab appeared first on Smithsonian Insider.

The post Museum Conservation Institute research scientist Ed Vicenzi discusses his work analyzing daguerreotypes appeared first on Smithsonian Insider.

The post Smithsonian conservators open 2001 Jim Thorpe Wheaties Box from the Smithsonian’s National Museum of the American Indian appeared first on Smithsonian Insider.

The post Conrad Labandiera, Smithsonian palentologist, studies fossils to learn how insects got along before flowering plants arrived appeared first on Smithsonian Insider.

Clip from silent edited film "Bryson Jones Travelogue: Lure of the West" (ca. 1927) shows Mount Rushmore National Memorial under construction, including blasting off cliff face, scaffolding, men working, and the completed monument.

The post Construction of Mount Rushmore National Memorial from the Smithsonian’s Human Studies Film Archives appeared first on Smithsonian Insider.

The post How do paleontologists reconstruct environments from the ancient past? appeared first on Smithsonian Insider.

The Smithsonian Tropical Research Institute

The post Join the longest conversation in tropical biology appeared first on Smithsonian Insider.

Scientists from the Migratory Bird Center of the Smithsonian Conservation Biology Institute are using transmitters to track the movements of shorebirds–the long-billed curlew, red knot, […]

The post Studying migratory connectivity of shorebirds on the Texas coast appeared first on Smithsonian Insider.

Seven red panda cubs were born at the Smithsonian Conservation Biology Institute! The cubs were born to mothers Nutmeg, Regan and Leo Mei. Keepers are […]

The post Red Panda Cubs Born at Conservation Biology Institute appeared first on Smithsonian Insider.

Identifying and understanding the migratory connectivity of birds throughout an entire annual cycle (not just the times of year they are in your back yard), […]

The post Video: Protecting songbirds by Better Understanding their Migratory connectivity appeared first on Smithsonian Insider.

A small Ontario company is putting together one of the most complete T. rex ever found. It will be on display at the Smithsonian.

The post T-rex reconstruction appeared first on Smithsonian Insider.

This is a short film showing the process of the detail paint work on the conservation of the original U.S.S. Enterprise studio model. The detail […]

The post U.S.S. Enterprise studio model conservation appeared first on Smithsonian Insider.

Oct. 4, 2016—The Smithsonian Conservation Biology Institute welcomed an Eld’s deer fawn Oct. 2 around 4:30 p.m. Both the fawn and her mom Sienna appear […]

The post Eld’s Deer Fawn Born at the Smithsonian Conservation Biology Institute appeared first on Smithsonian Insider.

Click here to read more about the work of the Laser Interferometer Gravitational-Wave Observatory. The Smithsonian has been celebrating innovation in American culture for more than […]

The post Stephen Hawking Congratulates LIGO Team on its Smithsonian American Ingenuity Award appeared first on Smithsonian Insider.