In the United States, natural-gas production from shale rock has increased by more than 700 percent since 2007. Yet scientists still do not fully understand […]

The post Biological fallout of shale-gas production still largely unknown appeared first on Smithsonian Insider.

Wetlands Wetlands are one of the habitats to benefit most from conservation. The North American Wetlands Conservation Act has enabled strategic conservation projects covering a […]

The post The State of the Birds: Four critical habitats (videos) appeared first on Smithsonian Insider.

Before iPhones and laptops there were human computers, some of whom worked at the Harvard College Observatory. Women like Henrietta Swan Leavitt, Williamina Fleming, and […]

The post Volunteers needed to preserve astronomical history and promote discovery appeared first on Smithsonian Insider.

Human skin and gut microbes influence processes from digestion to disease resistance. Despite the fact that tropical forests are the most biodiverse terrestrial ecosystems on […]

The post Smithsonian scientists discover tropical tree microbiome in Panama appeared first on Smithsonian Insider.

Scientists examining the stomach contents of invasive lionfish caught on the inner barrier reef of Belize have discovered that nearly half of the diet of […]

The post In Belize, Critically endangered wrasse now favorite food of invasive lionfish appeared first on Smithsonian Insider.

Surplus mustard gas canisters and unexploded bombs dumped in the Pacific Ocean near Hawaii after WWII, have become, scientists say, a potential reef that is […]

The post Old bombs, chemical weapons now home for deep-sea starfish appeared first on Smithsonian Insider.

When soil temperatures 8 inches under the ground reach a balmy 64 degrees Fahrenheit, periodical cicadas emerge on the U.S. East Coast. They tend to […]

The post Billions & Billions of Periodical Cicadas appeared first on Smithsonian Insider.

The next generation of the Sloan Digital Sky Survey (SDSS-V), directed by Juna Kollmeier of the Carnegie Institution for Science, will move forward with mapping […]

The post Next generation astronomical survey to map the entire sky 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.

Kasun Buddika, Ishara S. Ariyapala, Mary A. Hazuga, Derek Riffert, and Nicholas S. Sokol

Stressed cells downregulate translation initiation and assemble membrane-less foci termed stress granules (SGs). Extensively characterized in cultured cells, the existence of such structures in stressed adult stem cell pools remain poorly characterized. Here we report that Drosophila orthologs of mammalian SG components AGO1, ATX2, CAPRIN, eIF4E, FMRP, G3BP, LIN-28, PABP, and TIAR are enriched in adult intestinal progenitor cells where they accumulate in small cytoplasmic messenger ribonucleoprotein complexes (mRNPs). Treatment with sodium arsenite or rapamycin reorganized these mRNPs into large cytoplasmic granules. Formation of these intestinal progenitor stress granules (IPSGs) depended on polysome disassembly, led to translational downregulation, and was reversible. While canonical SG nucleators ATX2 and G3BP were sufficient for IPSG formation in the absence of stress, neither of them, nor TIAR, either individually or collectively, were required for stress-induced IPSG formation. This work therefore finds that IPSGs do not assemble via a canonical mechanism, raising the possibility that other stem cell populations employ a similar stress-response mechanism.

Olga Kopach, Noemi Esteras, Selina Wray, Dmitri A. Rusakov, and Andrey Y. Abramov

Frontotemporal dementia and parkinsonism (FTDP-17) caused by the 10+16 splice-site mutation in the MAPT provides an established platform to model tau-related dementia in vitro. Human iPSC-derived neurons have been shown to recapitulate the neurodevelopmental profile of tau pathology during in vitro corticogenesis as in the adult human brain. However, the neurophysiological phenotype of these cells has remained unknown, leaving unanswered questions over the functional relevance and the gnostic power of this disease model. Here we used electrophysiology to explore the membrane properties and intrinsic excitability of the generated neurons to find that human cells mature by ~150 days of neurogenesis to become compatible with matured cortical neurons. In earlier FTDP-17, neurons, however, exhibited a depolarized resting membrane potential associated with increased resistance and reduced voltage-gated Na⁺- and K⁺-channel-mediated conductance. The Na_v1.6 protein was reduced in FTDP-17. These led to a reduced cell capability of induced firing and changed action potential waveform in FTDP-17. The revealed neuropathology may thus contribute to the clinicopathological profile of the disease. This sheds new light on the significance of human models of dementia in vitro.

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.

Nearly four billion years ago, life arose on Earth. Life appeared because our planet had a rocky surface, liquid water, and a blanketing atmosphere. But […]

The post Sun-like Star Shows Magnetic Field Critical for Life on the early Earth appeared first on Smithsonian Insider.

Images obtained by NASA’s MErcury Surface, Space ENvironment, GEochemistry and Ranging (MESSENGER) spacecraft during the low-altitude orbital phase of the mission have revealed previously undetected […]

The post Mercury Joins Earth As Tectonically Active Planet appeared first on Smithsonian Insider.

Cambridge, MA -Physicists are capitalizing on a direct connection between the largest cosmic structures and the smallest known objects to use the universe as a […]

The post Scientists are using the universe as a “cosmological collider” appeared first on Smithsonian Insider.

Seven corrections are made and several supplementary equations are added to the article by Yoshimura [Acta Cryst. (2015), A71, 368–381].

Dr. JoGayle Howard of the Smithsonian's National Zoo discusses her work to breed and study one of the world's most endangered cats, the clouded leopard. More about the National Zoo's work to save clouded leopards: http://nationalzoo.si.edu/SCBI/ReproductiveScience/ConsEn...
http://nationalzoo.si.edu/support/annualappeal/cloudedleo... ... (more info)

The post Meet Our Scientist: Dr. JoGayle Howard of the Smithsonian’s National Zoological Park appeared first on Smithsonian Insider.

Smithsonian Tropical Research Center Botanist Stefan Schnitzer talks about his work studying lianas (woody vines) in the jungles of Panama. These hardy vines compete with trees for water and nutrients and also act as highways for jungle animals moving through the forest canopy.

The post Meet Our Scientist: Stefan Schnitzer – Tropical Vine Science appeared first on Smithsonian Insider.

What determines the variety of trees in a tropical forest? Is it the seed size? Perhaps seed-hungry animals? And what happens to forests that are being drastically changed by humans? Smithsonian Tropical Research Center Botanist, Helene Muller Landau, talks about her attempt to find answers to these questions.

The post Meet Our Scientist: Helene Muller Landau – Tropical Forest Science appeared first on Smithsonian Insider.

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

"I'm getting paid to do what I like doing," says entomologist David Roubik. He loved nature and being outdoors when he was a kid, and now he does fieldwork in the tropical forests of Panama. He loves to travel, and his research takes him around the world. Can his work, then, be called a job?

The post Tropical Research Institute entomologist David Roubik talks about his life as a scientist based in Panama appeared first on Smithsonian Insider.

Meet Smithsonian scientist Justin Touchon, a National Science Foundation (NSF) postdoctoral researcher at the Smithsonian Tropical Research Institute in Panama.

Justin's work focuses on developmental ecology and reproductive plasticity of the hourglass treefrog (Dendropsophus ebraccatus) and red-eyed treefrog (Agalychnis callidryas). Justin and his advisor, Karen Warkentin, were the first to have witnessed the frogs laying eggs in water, in addition to doing so on land -- something with major implications for the evolutionary biology of similar creatures.

The post Meet Our Scientist: Justin Touchon, Frog Follower at the Smithsonian Tropical Research Institute in Panama appeared first on Smithsonian Insider.

The Smithsonian Tropical Research Institute

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

Five critically endangered Cuban crocodiles hatched at the National Zoo’s Reptile Discovery Center between July 29 and Aug. 7. The eggs were laid by Dorothy, […]

The post Five Critically endangered Cuban crocodiles hatched at National Zoo appeared first on Smithsonian Insider.

Visits to the Smithsonian's National Zoo just became a little bit sweeter with the arrival of a new honeybee colony. With a hive made of glass in the Zoo's Pollinarium and full access to the outdoors, these bees are showing off the wondrous ways of their world.

The post Honeybees fascinate visitors at the National Zoological Park appeared first on Smithsonian Insider.

New results from a massive study at the Smithsonian Tropical Research Institute show that interactions among community members play an important role in determining which organisms thrive.

The post Tropical tree study shows interactions with neighbors plays an important role in tree survival appeared first on Smithsonian Insider.

The Center for Tropical Forest Science, which manages a global network of temperate and tropical forest research plots, will utilize the funds to conduct workshops in the Americas and Asia to investigate how taxonomic, functional, and genetic dimensions of diversity affect tree communities and their resilience to global change.

The post Center for Tropical Forest Science receives grant to study diversity of tree communities 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.

A new study shows that as climate change enhances tree growth in tropical forests, the resulting increase in litterfall could stimulate soil micro-organisms leading to a release of stored soil carbon.

The post Increased tropical forest growth may result in release of stored carbon in the soil appeared first on Smithsonian Insider.

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.

Studies at two remote Smithsonian Institution Global Earth Observatory sites in Panama and Thailand show the first evidence of long-term effects of nitrogen pollution in tropical trees.

The post Air pollution is fertilizing tropical forests appeared first on Smithsonian Insider.

Older forests with just the right fungi may be secret to saving these vulnerable plants.

The post Fungi-filled forests are critical if endangered orchids are to thrive appeared first on Smithsonian Insider.

The North Pole isn’t the only place on Earth affected by slight increases in temperature. Until recently, scientific thinking used to posit that tropical forests, […]

The post Rising temperatures mean more blooms for tropical rainforests appeared first on Smithsonian Insider.

Tropical forests speed their own recovery, capturing nitrogen and carbon faster after being logged or cleared for agriculture. Researchers working at the Smithsonian Tropical Research […]

The post Tropical forests “fix” themselves appeared first on Smithsonian Insider.

Mexico is the fourth largest honey producer and fifth largest honey exporter in the world. A Smithsonian researcher and colleagues helped rural farmers in Mexico […]

The post Genetically modified soybean pollen threatens Mexican honey sales appeared first on Smithsonian Insider.

What plant species has just been discovered but is almost gone? Bidens meyeri–a just discovered flowering plant from the small South Pacific island of Rapa, […]

The post New South Pacific cliff flower is critically endangered appeared first on Smithsonian Insider.

Scientific inspiration springs from many sources. In the case of Smithsonian botanist David Kenfack, ant bites were the inspiration for a recent paper he co-authored […]

The post Sweet life: tropical plants attract ants with sugary nectar appeared first on Smithsonian Insider.

A global analysis raises the minimum estimated number of tropical tree species to at least 40,000–53,000 worldwide in a paper appearing in Proceedings of the […]

The post Analysis: Many tropical tree species have yet to be discovered appeared first on Smithsonian Insider.

Although useful to Tarzan, vines endanger tropical forests’ capacity to store carbon. In a major experimental study in Panama, Smithsonian researchers showed that woody vines, […]

The post Climbing plants disturb carbon storage in tropical forests appeared first on Smithsonian Insider.

Profound ideas don’t need to be complicated. A simple cube made of aluminum tubing, a centerpiece of a new exhibit “Life in One Cubic Foot,” […]

The post From Rochester to Polynesia, a simple cube unveils Earth’s dazzling biological diversity appeared first on Smithsonian Insider.

Internet and phone connections are essential for effective communicators and for success in business. New results from the Smithsonian Tropical Research Institute in Panama show […]

The post Ant bridges connect tropical tree crowns appeared first on Smithsonian Insider.

A newly discovered Hawaiian tree recently had the distinction of being added to the International Union for the Conservation of Nature’s Red List of Critically […]

The post Newly named, Hawaiian tree species already critically endangered appeared first on Smithsonian Insider.

Rainforests on infertile wet soils support more than half of all plant species. Shrublands on infertile dry soils in southwestern Australia, jokingly called “knee-high tropical […]

The post Microbes rule in ‘knee-high tropical rainforests’ appeared first on Smithsonian Insider.

The post Global forest network cracks the case of tropical biodiversity appeared first on Smithsonian Insider.

Visitors to the tropics are amazed by the huge variety of colorful, complex and sometimes ferocious creatures living near the equator. Smithsonian scientists and colleagues […]

The post Is This the Long-Sought Answer to the Question of Tropical Biodiversity? 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.

The structural and nonlinear optical properties of a new anilinium hybrid crystal of chemical formula (C6H7NCl+·NO3−)3 have been investigated. The crystal structure was determined from single-crystal X-ray diffraction measurements performed at a temperature of 100 K which show that the compound crystallizes in a noncentrosymmetric space group (Pna21). The structural analysis was coupled with Hirshfeld surface analysis to evaluate the contribution of the different intermolecular interactions to the formation of supramolecular assemblies in the solid state that exhibit nonlinear optical features. This analysis reveals that the studied compound is characterized by a three-dimensional network of hydrogen bonds and the main contributions are provided by the O...H, C...H, H...H and Cl...H interactions, which alone represent ∼85% of the total contributions to the Hirshfeld surfaces. It is noteworthy that the halogen...H contributions are quite comparable with those of the H...H contacts. The nonlinear optical properties were investigated by nonlinear diffuse femtosecond-pulse reflectometry and the obtained results were compared with those of the reference material LiNbO3. The hybrid crystals exhibit notable second (SHG) and third (THG) harmonic generation which confirms its polarity is generated by the different intermolecular interactions. These measurements also highlight that the THG signal of the new anilinium compound normalized to its SHG counterpart is more pronounced than for LiNbO3.