Giant prehistoric crocodile shieldcroc identified

first_imgImage: Henry Tsai, University of Missouri © 2011 PhysOrg.com Discovered in Morocco and subsequently carted off to the Royal Ontario Museum in Canada, the head sat ignored for nearly a decade before Casey Holliday, a paleontologist at the University of Missouri decided to look a little deeper. After analysis the head piece turned out to be from an animal that belonged to the family crocodyliforms, which of course is where modern crocodiles, alligators, caimans and others come from.Interestingly, despite its massive size, the old croc appears to have been rather weak jawed, and thus was more likely to eat fish swimming by (such as the car-length coelacanths) than grabbing animals off the shore and twisting them down into the water to drown them as modern crocs do.Holliday believes the shield was used to help cool the animal, due to the presence of skin and blood vessels similar to those in the frill of triceratops. Thus it would have been too soft to serve as protection, which makes Holliday believe it was likely mostly used to either frighten off other males, or to attract females.Also, because the head fragment was found in Morocco, new fuel has been added to fire in the ongoing debate among paleontologists regarding the origins of crocodyliforms. This new evidence points to North Africa of course, near the Mediterranean, though many still believe the original location was much farther north But since we’re talking about animals that lived around a hundred million years ago; so far back that land masses were configured differently from today, it’s likely the arguments will go on without ever being proved one way or the other.Holliday says the shieldcroc likely had an extra long face that was sort of flat with a roundish nose and small teeth. Its head alone was likely the size of a full-grown man. He also believes the giant beast’s feeding habits were more like modern pelicans than crocodiles and alligators. Ancient crocodile relative likely food source for Titanoboa (PhysOrg.com) — A scientist working in Canada studying a part of a head of a dinosaur found some ten years ago in Morocco, has uncovered what may be the great granddaddy of all modern crocs. The ancient beast, believed to have been wandering around during the Cretaceous period is estimated to have been nearly the length of a school bus and had a strange shield type crown covering the top of his head that researchers believe might have been more for showing off than fighting.center_img Explore further Citation: Giant prehistoric crocodile ;shieldcroc; identified (2011, November 10) retrieved 18 August 2019 from https://phys.org/news/2011-11-giant-prehistoric-crocodile-shieldcroc.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.last_img read more

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Automated meter reading systems make life easy for intruders

first_img Citation: Automated meter reading systems make life easy for intruders (2012, October 20) retrieved 18 August 2019 from https://phys.org/news/2012-10-automated-meter-life-easy-intruders.html An aerial view of the neighborhood where the researchers performed their eavesdropping experiments. Each blue triangle or red star represents a group of four or five meters mounted in a cluster on an exterior wall. Using an LNA and a 5 dBi omnidirectional antenna, they were able to monitor all meters in the neighborhood. Some sniffed meters may be out of the scope of this view. Credit: Ishtiaq Rouf et al. More information: Research paper: www.winlab.rutgers.edu/~grutes … ers/fp023-roufPS.pdfvia Newscientist Explore further This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. (Phys.org)—Intruders of the break-in and snooping variety have their work cut out for them by just picking up wireless signals that are broadcast by utility meters, say researchers from the University of South Carolina at Columbia, IEEE and Rutgers. As with many other technological advances that bring new pathways for criminals, advances in meters have created concerns about intrusions. Millions of analogue meters to measure water, gas and electricity consumption have been replaced by automated meter reading (AMR) in the U.S. The newer method enables devices to broadcast readings by radio every 30 seconds for utility company employees to read as they walk or drive around with a receiver. Intruders can tune into the same information, however, according to Ishtiaq Rouf and his colleagues, authors of a paper that delivers a security analysis of AMR systems. More than 40 million meters in the United States have been equipped with AMR technology over the past years. The smart meters collect energy consumption data which could reveal sensitive personal information from homes, they said. Because energy usage often drops to near zero when a house is empty, the readings could be used to identify which owners are at work or traveling. Their work shows that currently deployed AMR systems are vulnerable to spoofing attacks and privacy breaches. The research was presented earlier this week at the 19th ACM Conference on Computer and Communications Security, which ran from October 16 to 18 in Raleigh, North Carolina. The AMR meters that they studied make data publicly available over unsecured wireless transmissions. “They use a basic frequency hopping wireless communication protocol and show no evidence of attempting to ensure confidentiality, integrity, and authenticity of the data,” added the research team.They picked up transmissions from AMR meters operated by companies. They said that the communication protocol can be reverse-engineered with only a few days of effort. They made use of radio equipment and information available through online tutorials. They used software radio equipment publicly available for about $1,000 (GNU Radio with the Universal Software Radio Peripheral). “We were able to both eavesdrop on messages as well as spoof messages to falsify the reading captured by a commonly used ‘walk-by’ reader,” they said. Through wireless monitoring, they harvested consumption data from 485 meters within a 300m radius region.As remedies, the authors suggested alternative schemes based on defensive jamming, which they said may be easier to deploy than upgrading meters themselves. Jamming could protect against the leakage of legacy devices and requires no modification of the deployed meters. © 2012 Phys.org Google’s PowerMeter Will Help Reduce Energy Consumption (Video)last_img read more

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Nanoscale magnetic imaging of ferritin in a single cell

first_img This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. In the present work, Wang et al. reported two technical advancements to allow nanoscale MI of intracellular proteins within a single cell. For this, they freeze-fixed the cell to a solid state and intricately segmented it to a cube shape, then placed it on a tuning fork scanning probe of an atomic force microscope (AFM) for imaging, where the flat cross section of the cell was exposed to air. The scientists used the sample placement setup to allow the NV sensor to be positioned within 10 nm of the target proteins and used the AFM to suppress thermal drift during sample positioning. They then engineered trapezoidal cylinder-shaped nanopillars at a bulk diamond surface for image acquisition, technically shortening the time of image acquisition by one order compared to previous methods. In the present study, the scientists used this technique to conduct in situ MI of the magnetic fluctuating noise of intracellular ferritin proteins (a biomarker of iron stores and transferrin saturation in the body) within the experimental setup. In life sciences, the ability to measure the distribution of biomolecules inside a cell in situ is an important investigative goal. Among a variety of techniques, scientists have used magnetic imaging (MI) based on the nitrogen vacancy center (NV) in diamonds as a powerful tool in biomolecular research. However, nanoscale imaging of intracellular proteins has remained a challenge thus far. In a recent study now published in Science Advances, Pengfei Wang and colleagues at the interdisciplinary departments of physics, biomacromolecules, quantum information and life sciences in China, used ferritin proteins to demonstrate the MI realization of endogenous proteins in a single cell, using the nitrogen-vacancy (NV) center as the sensor. They imaged intracellular ferritins and ferritin-containing organelles using MI and correlative electron microscopy to pave the way for nanoscale magnetic imaging (MI) of intracellular proteins. The scientists measured fluorescence decay at a fixed free evolution time of 50 microseconds (τ = 50 μs) to reveal the degree of NV sensor spin polarization, which correlated with the amount of ferritin in the sensing volume. They observed the appearance of some clusters via both TEM and MI images, although some details were not observed in MI, the results confirmed that spin noise from intracellular ferritin contributed to depolarize the NV center. In order to obtain details of the ferritin clusters at higher resolution, the scientists minimized the pixel size to 8.3 nm and acquired MI of high resolution of the proteins as expected. In this way, Wang et al. explored the sensitivity of NV centers as an appropriate sensor for biological imaging applications at the level of the single molecule. They used the technique as a sensor in the experimental setup to obtain the first MI of a protein at a resolution of 10 nm in situ. The scientists aim to improve the stability and sensitivity of the technique to speed up the scanning process and image a larger area of interest in the cell and locate ferritin beyond the nucleus in association with additional organelles. New method discovered to view proteins inside human cells Explore further Ferritin is a globular protein complex with an outer diameter of 12 nm, containing a cavity spanning 8 nm in diameter that allows up to 4500 iron atoms to be stored within the protein. The magnetic noise of the ferric ions can be detected due to their effects on the T1 relaxation time of an NV center. In this work, Wang et al. confirmed the observation using fluorescence measurements of time-dependent decay of the population of NV centers (magnetic spin, mS = 0 state), in a diamond surface coated with ferritins. Additionally, the scientists detected the magnetic noise with label-free methods using the NV center via transmission electron microscopy (TEM). The work allowed the development of a correlated MI and TEM scheme to obtain and verify the first nanoscale MI of a protein in situ. The scientists used the hepatic carcinoma cell line (HepG2) for the experiments and studied iron metabolism by treating the cells with ferric ammonium citrate (FAC), which significantly increased the amount of intracellular ferritin. They verified this using confocal microscopy (CFM), western blotting and TEM techniques at first. The results showed the primary localization of ferritins in the intracellular puncta around the nucleus, among the cytoplasm. The scientists used bulk electron paramagnetic resonance (EPR) spectroscopy to confirm the paramagnetic properties of ferritin in the FAC-treated HepG2 cells and mass spectroscopy to measure the interference due to other paramagnetic metal ions. Journal information: Science Advances © 2019 Science X Network Increasing existing spatial resolution of biomedical imaging is required to achieve ongoing demands in medical imaging, and therefore, among a variety of techniques, magnetic imaging is of broad interest at present. Magnetic resonance imaging (MRI) is widely used to quantify the distribution of nuclear spins but conventional MRI can only reach a resolution of 1 µm in nuclear spin imaging where the resolution is limited by electrical detection sensitivity. Scientists have developed a series of techniques to break this resolution barrier, including a superconducting quantum interference device and magnetic resonance force microscopy. Nevertheless, these reports require a cryogenic environment and high vacuum for imaging, limiting the experimental implementation and its translation to clinical practice. A recently developed quantum sensing method based on the nitrogen vacancy center in diamond has radically pushed the boundary of MI techniques at the nanoscale to detect organic molecules and proteins in the lab. Scientists have combined quantum sensing with NV centers and scanning probe microscopy to demonstrate nanoscale MRI for single electron spin and small nuclear spin ensemble while using the NV center as a biocompatible magnetometer to noninvasively image ferromagnetic particles within cells at the subcellular scale (0.4 µm). For example, depolarization of the NV center can be used as a wideband magnetometer to detect and measure fluctuating noise from metal ions and nuclear spins. However, such imaging of single proteins via MI at the nanoscale has not been reported in the single cell thus far. Citation: Nanoscale magnetic imaging of ferritin in a single cell (2019, April 18) retrieved 18 August 2019 from https://phys.org/news/2019-04-nanoscale-magnetic-imaging-ferritin-cell.html Correlative MI and TEM images. (A) Schematic view of sectioning for correlative MI and TEM imaging. The last section and the remaining cube were transferred for TEM imaging and MI scanning, respectively. The sectioning resulted in some split ferritin clusters that could be imaged under both microscopes. A transparent blue strip of ~10 nm indicates the imaging depth of the MI, while in the TEM, the imaging depth is ~100 nm. (B) Distribution of ferritins from the last ultrathin section under TEM. Inset: Magnified figure of the part in black dashed box. (C) MI result of the remaining cell cube. The pixel size is 43 nm. (D) The merged MI and TEM micrograph shows ferritins in a membrane-bound organelle. The red arrows in (B) to (D) indicate the same ferritin cluster. Scale bars, 5 μm (B) and 1 μm [B (inset), C, and D]. Credit: Science Advances, doi: 10.1126/sciadv.aau8038.center_img TOP – The preparation and characterization of ferritin-rich HepG2 cell samples. (A) Schematic view of the treatment to cultured cells. Following iron loading or no treatment, the HepG2 cells were examined for fluorescence images and EPR spectra, respectively. For the MI and TEM imaging, cell samples were treated through high-pressure freezing, freeze substitution, and sectioning. (B) Representative confocal microscopy (CFM) image of ferritin structures (green) in iron-loaded HepG2 cells. The ferritin proteins were immunostained by anti-ferritin light chain antibody. The nuclei are indicated by 4′,6-diamidino-2-phenylindole (DAPI) in the blue channel. Inset displays magnified ferritin structures. The yellow dashed line outlines the contour of a cell. Scale bar, 20 μm. (C) EPR spectra of control and iron-loaded HepG2 cells at T = 300 K. BOTTOM – Adjusting the distance between the NV center and the cell section. (A) Interference fringes between the cell cube and the diamond surface. Scale bar, 20 μm. (B) The geometric relation and the gap R between cell samples and diamond-pillars for MI. The top surface diameter of the nanopillar is 400 nm. Credit: Science Advances, doi: 10.1126/sciadv.aau8038. The work will contribute to clinical diagnostics to determine biomarker-based iron storage and release in cells. This will include studies on the regulatory mechanisms of iron metabolism during the progression of hemochromatosis, anemia, liver cirrhosis and Alzheimer’s disease. Wang et al. propose to extend the approach in situ to other cellular components with paramagnetic signals, including magnetic molecules, metalloproteins and special spin-labelled proteins. The scientists envision that further studies will explore additional targets suitable for high-resolution MI and correlated TEM imaging techniques, with optical microscopy detection incorporated to the experimental setup to extend the work and determine protein nuclear spin MRI as well as perform three-dimensional cell tomography. More information: Mamin H.J. et al. February 2013, Science. Pengfei Wang et al. Nanoscale magnetic imaging of ferritins in a single cell, Science Advances (2019). DOI: 10.1126/sciadv.aau8038 Denis Vasyukov et al. A scanning superconducting quantum interference device with single electron spin sensitivity, Nature Nanotechnology (2013). DOI: 10.1038/nnano.2013.169 D. Rugar et al. Single spin detection by magnetic resonance force microscopy, Nature (2004). DOI: 10.1038/nature02658H. J. Mamin et al. Nanoscale Nuclear Magnetic Resonance with a Nitrogen-Vacancy Spin Sensor, Science (2013). DOI: 10.1126/science.1231540 , Nature Nanotechnology Wang et al. then used ultrafast, high-pressure freezing to immobilize all intracellular components of the Fe-loaded cells. The process stabilized the intracellular structures and molecules by minimizing Brownian motion in cells, which typically contributes to random motion of proteins up to 100 nm in vivo. To image the samples, they embedded and polymerized the frozen cells in LR White medium, followed by gluing the embedded cell sample to the AFM tuning fork with a few cells at the tip. Using a diamond knife, the scientists then sectioned the tip surface to nanometer flatness to examine the cuboid cell section under AFM. They acquired MI images of ferritins by scanning the cell cube along the diamond nanopillars and simultaneously measured NV spin repolarization rate using the “leapfrog” scanning mode of the microscope as detailed previously. , Science , Nature Schematic of the setup and experimental principle. (A) Schematic view of the experimental setup. The cell embedded in resin is attached to a tuning fork and scans above the diamond nanopillar that contains a shallow NV center. A copper wire is used to deliver the microwave pulse to the NV center. A green laser (532 nm) from the confocal microscope (CFM) is used to address, initialize, and read out the NV center. (B) Left: Crystal lattice and energy level of the NV center. The NV center is a point defect that consists of a substitutional nitrogen atom and an adjacent vacancy in diamond. Right: Schematic view of a ferritin. The black arrows indicate the electron spins of Fe3+. (C) Experimental demonstration of the spin noise detection with and without ferritin in the form of polarization decay for the same NV center. The inset is the pulse sequence for detection and imaging of the ferritin. A 5-μs green laser is used to initialize the spin state to ms = 0, followed by a free evolution time τ to accumulate the magnetic noise, and finally the spin state is read out by detecting the fluorescence intensity. The pulse sequence is repeated about 105 times to acquire a good signal-to-noise ratio (SNR). The relaxation time is fitted to be 0.1 and 3.3 ms by exponential decay for the case with and without ferritin, respectively, indicating a spin noise of 0.01 mT2. Credit: Science Advances, doi: 10.1126/sciadv.aau8038. LEFT – Experimental setup. The experiment was carried out on a homebuilt setup, which combined optically detected magnetic resonance microscopy (ODMR) with atomic force microscopy (AFM). DM: dichroic mirror. BP: bandpass filter working at 650–775 nm. APD: avalanche photodiode. CCD: charge coupled device. LED: light emitting diode of 470 nm. AL: achromatic lens. PH: pinhole at a size of 30 μm. BS: beam splitter. RIGHT – Images of the nanopillars on diamonds. (A) SEM imaging of the fabricated diamond nanopillars just after reactive ion etching (RIE). The top of the nanopillar is covered by the hydrogen silsesquioxane (HSQ) to protect the NV center. (B) A single trapezoidal-cylinder shaped nanopillar to sense cell sections adhered at the AFM tip. Scale bars, 10 μm (A); 400 nm (B). Credit: Science Advances, doi: 10.1126/sciadv.aau8038. (A) Ferritin cluster imaged by the NV sensor with 80 × 24 pixels and a pixel size of 8.3 nm. Scale bar, 100 nm. (B) Trace data of the scanning line in (A) directed by the red arrow. The platform indicates the ferritin cluster. The red curve fitted by a plateau function serves as a guide to the eye. (C) Magnified figure of the gold dashed box in (B). The sharp transition indicated by the red arrow around x = 283 nm shows the scanning from the blank area to the area with ferritins. Credit: Science Advances, doi: 10.1126/sciadv.aau8038.last_img read more

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Watch out for the Bikers

first_imgToday, Delhi’s men are doing something that nobody thought of, they are asking women to take charge of their lives. How?Realising that their women are yet not safe in the Capital, a Delhi based biker group Bikers for Good are organising a ride cum rally from South Extension till Kingdom of Dreams on Sunday morning. The ride is called I’m Power- Delhi Bikers Empower Women.This ride also marks the second anniversary of the group. The ride has been planned by the founder of the group Mohit Ahuja. ‘It is practically impossible to be with our women all the time, to protect them. The government doesn’t seem to show interest towards taking serious action. Looking at the recent cases I feel all that has happened in the name of women empowerment till date has gone waste as it is mere education given to the men,’ he said. The ride has been gaining a considerable amount of support from the people looking forward to attend it and most of these are men. All the bikers are invited with their female friends. However, going against stereotypes of Men being ‘Bikers’, the ride consist of both men and women riding together for the common cause. Also Read – ‘Playing Jojo was emotionally exhausting’With this ride, Bikers for Good is raising many issues like female sexual abuse, their safety and also they are asking the government for more practical solutions regarding women safety. Talking about the same Ahuja says, ‘There is only one solution to this problem, arm the women! If every woman has the power to protect themselves, then we don’t need women empowerment. If the government can distribute free condoms, medicines and vaccines in government hospitals and dispensaries, then why not pepper sprays?’Never before have Delhi’s men given the baton in the hands of the women and asked them to be their own saviours. Bikers for Good looks at distributing free pepper sprays to these women, highlighting the fact that they can take responsibility for themselves rather than depending on anybody else.last_img read more

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Delhi to romance Romeo and Juliet

first_imgThe show is to be presented as homage to the pioneer of Opera in India, Francis Wacziarg. Charles Gounod who composed the music of the Opera had long been interested in turning the Shakespeare play into an opera. His librettists Jules Barbier and Michel Carré purposefully chose to adhere closely to Shakespeare’s play as seen in the choral prologue which contains the words of the dialogue from the play.The opera is in five acts: The Capulets’ Ball, The Garden of Juliet, the Cell of Friar Laurence and a Street near the Capulet’s Palace, Juliet’s Room at Dawn, and Juliet’s Tomb. The cast includes Indian singers Amar Muchhala (tenor) from London as Romeo, Aude Priya (soprano) who has been a part of many other productions by TNMF, as Juliet, Vikrant Subramanian (baritone) as Mercutio, Sparsh Bajpai (soprano) as Stefano, Toshanbor Singh Nonbet (tenor) as Benvolio, Prabhat Chandola (tenor) as Tybalt, Madhav Raina Thapan (baritone) as Paris, Clifford Afonso (baritone) as Gregorio,  Ramya Roy (Mezzo Soprano) as Getrude, and visiting singers from France Paul Medioni (Bass) as Friar Laurent and Bernard Ohanian(baritone) as count Capulet.  A symphonic instrumental concert on the theme of ‘Destiny’ is also being presented on 20th March at 7.00 pm at Kamani Auditorium with the Orchestra of the Romeo & Juliet opera, joined by Indian musicians.WHEN: 18, 19, 21 MarchWHERE: Kamani Auditoriumlast_img read more

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Rousseff reelected on call to save Brazils social gains

first_imgIn a campaign that featured ‘change’ as the buzzword for both sides, the incumbent argued that Neves’s economic proposals would produce recession and erase gains for 36 million Brazilians who have risen from extreme poverty under her party’s rule. Rousseff in her victory speech pledged to engage in dialog as she vows to stimulate economic growth and fight corruption. ‘Some times in history, narrow results produced much stronger changes than very wide victories,’ she said in Brasilia. ‘From now on in Brazil we will have a debate of ideas, clash of positions that may produce areas of consensus capable of moving our society along the paths of change that we so badly need. My first words are a call for peace and unity.’ Neves said in his concession speech that he phoned Rousseff to casking to unite the country.last_img read more

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