Archives, Room Use Only - HE336.E94 O74 1858

Archives, Room Use Only - CS71.M885 L67 1896

Archives, Room Use Only - TK6540.S86 1950

Archives, Room Use Only - TK5243.M7 M46 1875

Archives, Room Use Only - Q143.J5 S74 1901

Archives, Room Use Only - TK6547.I56 2006

President Ram Nath Kovind and Prime Minister Narendra Modi welcomed Trump and First Lady Melania Trump at the Rashtrapati Bhavan.

The women agitators have been on a sit-in at Shaheen Bagh for over three months, protesting the newly amended Citizenship Act .

Unconscious children being carried by parents in their arms, people laying on roads, health workers scrambling to attend to those affected by the styrene vapour leak and residents fleeing were some of the scenes that played out near Visakhapatnam on Thursday, bringing back grim memories of the 1984 Bhopal gas tragedy.

THANJAVUR The All India Trade Union Congress will be organising a demonstration on May 11 to press the Union and State governments to expedite the pro

Vizag gas leak: Chilling scenes bring back memories of Bhopal gas tragedy

US PGA's Memorial to track fans to maintain COVID-19 social distancing

The age-old Elephant Gate bridge was fully demolished on Saturday. The Southern Railway dismantled the railway overbridge (ROB) within 12 days, after

BJP MLAs will meet CM Arvind Kejriwal on Monday and submit a memorandum to draw his attention to increasing cases of COVID-19, the alleged poor condit

Biggest tremor on record at Little Plumpton site forces halt to fracking in Lancashire  Lancashire Evening Post

UK's only active fracking site near Blackpool records largest ever earth tremor as homeowners complain of windows shaking  iNews

Did the quake shake you? Earth tremor felt in Shropshire  shropshirestar.com

Largest tremor yet detected at Lancashire fracking site  ITV News

Somerset earthquake: Homes shaken by 3.2 magnitude tremor  BBC News

Did the earth move for you? British Geological Survey has asked if Cumbrians felt an earth tremor last week  News & Star

The bond-valence method was performed on 51 crystal data sets from nitrogenase proteins, indicating the presence of molybdenum(III) in FeMo cofactors and vanadium(III) with more reduced iron complements in FeV cofactors.

For Heusler-type Ni–Mn–Ga ferromagnetic shape-memory alloys, the configuration of the martensite variants is a decisive factor in achieving a large magnetic shape-memory effect through field-induced variant reorientation. Based upon the spatially resolved electron backscatter diffraction technique, the microstructural evolution associated with the martensitic transformation from austenite to seven-layered modulated (7M) martensite was investigated on a polycrystalline Ni53Mn22Ga25 alloy. It was clearly shown that grain interior nucleation led to the formation of diamond-shaped 7M martensite within the parent austenite matrix. This diamond microstructure underwent further growth through an isotropic expansion with the coordinated outward movement of four side habit planes, followed by an anisotropic elongation with the forward extension of a type-I twin pair. A two-step growth model is proposed to describe the specific morphology and crystallography of 7M martensite. In addition, the habit planes were revealed to possess a stepped structure, with the {1 0 1}A plane as the terrace and the {0 1 0}A plane as the step. The characteristic combination of martensite variants and the underlying mechanism of self-accommodation in the martensitic transformation have been analysed in terms of the minimum total transformation strain, where the deformation gradient matrix was constructed according to the experimentally determined orientation relationship between the two phases. The present results may deepen the understanding of special martensite microstructures during the martensitic transformation in ferromagnetic shape-memory alloys.

100 kV is investigated as the operating voltage for single-particle electron cryomicroscopy (cryoEM). Reducing the electron energy from the current standard of 300 or 200 keV offers both cost savings and potentially improved imaging. The latter follows from recent measurements of radiation damage to biological specimens by high-energy electrons, which show that at lower energies there is an increased amount of information available per unit damage. For frozen hydrated specimens around 300 Å in thickness, the predicted optimal electron energy for imaging is 100 keV. Currently available electron cryomicroscopes in the 100–120 keV range are not optimized for cryoEM as they lack both the spatially coherent illumination needed for the high defocus used in cryoEM and imaging detectors optimized for 100 keV electrons. To demonstrate the potential of imaging at 100 kV, the voltage of a standard, commercial 200 kV field-emission gun (FEG) microscope was reduced to 100 kV and a side-entry cryoholder was used. As high-efficiency, large-area cameras are not currently available for 100 keV electrons, a commercial hybrid pixel camera designed for X-ray detection was attached to the camera chamber and was used for low-dose data collection. Using this configuration, five single-particle specimens were imaged: hepatitis B virus capsid, bacterial 70S ribosome, catalase, DNA protection during starvation protein and haemoglobin, ranging in size from 4.5 MDa to 64 kDa with corresponding diameters from 320 to 72 Å. These five data sets were used to reconstruct 3D structures with resolutions between 8.4 and 3.4 Å. Based on this work, the practical advantages and current technological limitations to single-particle cryoEM at 100 keV are considered. These results are also discussed in the context of future microscope development towards the goal of rapid, simple and widely available structure determination of any purified biological specimen.

The crystal structure of haemoglobin from Atlantic cod has been solved to 2.54 Å resolution. The structure consists of two tetramers in the crystallographic asymmetric unit. The structure of haemoglobin obtained from one individual cod suggests polymorphism in the tetrameric assembly.

Archaea are motile by the rotation of the archaellum. The archaellum switches between clockwise and counterclockwise rotation, and movement along a chemical gradient is possible by modulation of the switching frequency. This modulation involves the response regulator CheY and the archaellum adaptor protein CheF. In this study, two new crystal forms and protein structures of CheY are reported. In both crystal forms, CheY is arranged in a domain-swapped conformation. CheF, the protein bridging the chemotaxis signal transduction system and the motility apparatus, was recombinantly expressed, purified and subjected to X-ray data collection.

The anemones—both of which are commonly called Tealia red anemones under the species of Urticina—spawned in late April and early May, just days apart. Henley collected the eggs and sperm from the more than 2,000-gallon tank and put them together in smaller tanks to increase the chances of fertilization. After fertilization, the larvae settled and metamorphosed into a polyp.

The post National Zoo scientists successfully grow two species of anemones in aquarium tanks appeared first on Smithsonian Insider.

Viewed from inside the SOMATOM Emotion 6CT scanner used at the Smithsonian’s National Museum of Natural History, the skeleton and internal organs of this well-preserved […]

The post Peruvian mummy as seen by a SOMATOM Emotion 6CT scanner appeared first on Smithsonian Insider.

The remora's sucker disc is "one of the most remarkable and most highly modified skeletal structures among vertebrates."

The post New study proves the remora’s sucker disc is in fact a highly modified dorsal fin / Q&A with taxonomist David Johnson appeared first on Smithsonian Insider.

The bond-valence method has been used for valence calculations of FeMo/V cofactors in FeMo/V proteins using 51 crystallographic data sets of FeMo/V proteins from the Protein Data Bank. The calculations show molybdenum(III) to be present in MoFe7S9C(Cys)(HHis)[R-(H)homocit] (where H4homocit is homocitric acid, HCys is cysteine and HHis is histidine) in FeMo cofactors, while vanadium(III) with a more reduced iron complement is obtained for FeV cofactors. Using an error analysis of the calculated valences, it was found that in FeMo cofactors Fe1, Fe6 and Fe7 can be unambiguously assigned as iron(III), while Fe2, Fe3, Fe4 and Fe5 show different degrees of mixed valences for the individual Fe atoms. For the FeV cofactors in PDB entry 5n6y, Fe4, Fe5 and Fe6 correspond to iron(II), iron(II) and iron(III), respectively, while Fe1, Fe2, Fe3 and Fe7 exhibit strongly mixed valences. Special situations such as CO-bound and selenium-substituted FeMo cofactors and O(N)H-bridged FeV cofactors are also discussed and suggest rearrangement of the electron configuration on the substitution of the bridging S atoms.

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.

Keepers at the Smithsonian's National Zoo perform an artificial insemination procedure on a pair of Stanley Cranes. A Stanley Crane chick was successfully hatched on May 23, 2011.

The post Bird keepers at the National Zoo demonstrate the art of artificially inseminating Stanley cranes 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.

Tuvan ensemble Alash demonstrates various traditional throat singing styles that they use in their music. Smithsonian Folkways Recordings video.

The post Alash demonstrates throat singing styles appeared first on Smithsonian Insider.

The storage and flux of terrestrial carbon (C) is one of the most uncertain components of the global C budget and detailed quantification of forest […]

The post Remote sensing of a Smithsonian forest with airborne LiDAR appeared first on Smithsonian Insider.

At the 2018 Smithsonian Folklife Festival, Armenian participants Mariam Hovhannisyan and Stepan Toroyan—who were recently married—recreated a traditional ceremony on the National Mall, with contributions […]

The post Armenian Wedding Ceremony appeared first on Smithsonian Insider.

In Armenia, the completion of a carpet and cutting it from its loom is a significant rite of passion for young female weavers.

The post Smithsonian Folklife Festival: Armenian carpet-cutting ceremony appeared first on Smithsonian Insider.