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65 articles from PhysOrg

Webb's primary mirror deployment has begun

Engineers have begun the final stage of Webb's major structural deployments: the unfolding of its two primary mirror wings. These side panels, which were folded back for launch, each hold three of the observatory's 18 hexagonal, gold-coated mirror segments.

Winter storm snarls travel, gives some schools the day off

A winter storm that had already blanketed parts of the South in snow moved into the Northeast on Friday, snarling air travel, crushing morning commutes and giving hundreds of school districts struggling to keep kids in the classroom during a wave of new coronavirus cases an excuse to shut down for a one-day respite.

Life in the 'dead' heart of Australia

A team of Australian and international scientists led by Australian Museum (AM) and University of New South Wales (UNSW) paleontologist Dr. Matthew McCurry and Dr. Michael Frese of the University of Canberra has discovered and investigated an important new fossil site in New South Wales, Australia, containing superb examples of fossilized animals and plants from the Miocene epoch. The team's...

Nonequilibrium mechanism of bacterial flagellar motor switching revealed

In work published in Physical Review Letters, a research group led by Prof. Yuan Junhua and Prof. Zhang Rongjing from the University of Science and Technology of China (USTC) of the Chinese Academy of Sciences proposed a novel nonequilibrium mechanism in the allosteric regulation of motor switching, based on a precise measurement of the switching dynamics of the bacterial flagellar motor. This...

Light-controlled 'drug-free' macromolecules for precise tumor therapy

Drug-free macromolecular therapies can induce cell apoptosis by clustering non-internalizing cell-surface receptors. These show enormous promise in tumor treatment, particularly in terms of non-specific toxicities when compared with low-molecular-weight drugs. However, most reported drug-free macromolecular therapies involve a 'two-step' administration manner and there is a paucity of in vivo...

Racial demographics influence school choices for white, Asian and Latino parents, finds study of NYC school preferences

White, Asian and Latino parents in New York City all express strong racial/ethnic preferences in where to send their kids to high school, according to a study just published in Sociology of Education. The study suggests that these preferences contribute substantially to school segregation in New York, which has one of the most racially segregated school systems in the country.

Our galaxy's most recent major collision

One of the characteristic features of modern cosmology is its description of how galaxies evolve: via a hierarchical process of colliding and merging with other systems. Nowhere in the universe do we have a clearer view of this buildup than in our own Milky Way. Currently one of our nearby neighbors, the Sagittarius dwarf galaxy, is being tidally disrupted (a dwarf galaxy has less than about 1% of...

Budget of dissolved organic carbon in the South China Sea assessed by an eddy-resolving ocean model

Dissolved organic carbon (DOC) makes up the majority of marine organic carbon. Understanding its source and sink processes is of great significance to the global carbon cycle and will provide insights in achieving carbon neutrality. How do different physical and biogeochemical processes interact to contribute to the budgets of DOC and particulate organic carbon (POC)? Are there unique dynamics in...

Leveraging social media during a disaster

During a disaster, many people turn to social media seeking information. But communicating during disasters is challenging, especially using an interactive environment like social media where misinformation can spread easily.

Integrated photonics for quantum technologies

An international team of scientists, headed up by Paderborn physicist Professor Klaus Jöns, has compiled a comprehensive overview of the potential, global outlook, background and frontiers of integrated photonics. The paper—a roadmap for integrated photonic circuits for quantum technologies—has now been published in Nature Reviews Physics. The review outlines underlying technologies, presents...

Eccentric exoplanet discovered

Led by the University of Bern, an international research team has discovered a sub-Neptune exoplanet orbiting a red dwarf star. The discovery was also made thanks to observations performed by the SAINT-EX observatory in Mexico. SAINT-EX is run by a consortium including the Center for Space and Habitability (CSH) at the University of Bern and the National Center of Competence in Research NCCR...

A new cholera strain replaced older strains during the seventh cholera pandemic

The bacterium Vibrio cholerae is the causative agent of the diarrheal disease cholera and is responsible for seven known pandemics. The seventh cholera pandemic began in 1961 and is still active. Unlike previous pandemics, it is caused by cholera strains of a slightly different type. How did the modified cholera strains develop and spread, and what might have contributed to their success?...

Why doesn't Webb have deployment cameras?

As NASA's James Webb Space Telescope makes its way out to its intended orbit, ground teams monitor its vitals using a comprehensive set of sensors located throughout the entire spacecraft. Mechanical, thermal, and electrical sensors provide a wide array of critical information on the current state and performance of Webb while it is in space.

Scientist aims to ensure 'microbe-free' Mars samples

The Mars 2020 Perseverance Rover is collecting samples in search of signs of ancient microbial life, which would advance NASA's quest to explore the past habitability of Mars. The samples are set to return to Earth no earlier than 2031, as part of the Mars Sample Return campaign being planned by NASA and the European Space Agency. Before the rover went to space, NASA and its engineers worked hard...

A cointegrating relationship between the COVID-19 global fear index and stock returns

Researchers in Fiji have used the recently developed COVID-19 based global "fear index" to investigate the impact of the pandemic on nine major Asia-Pacific countries, specifically: Australia, China, Hong Kong, India, Japan, Malaysia, Singapore, Taiwan, and Thailand. The results for the period February 2020, just before the WHO declaration of the pandemic status of the disease, to November 2020...

Webb's specialized heat radiator deployed successfully

At about 8:48 a.m. EST, a specialized radiator assembly necessary for Webb's science instruments to reach their required low and stable operating temperatures deployed successfully. The Aft Deployable Instrument Radiator, or ADIR, is a large, rectangular, 4- by 8-foot panel, consisting of high-purity aluminum subpanels covered in painted honeycomb cells to create an ultra-black surface. The ADIR,...

Scientists uncover the distribution and physiological role of planteose

Witchweed (Striga spp.) and broomrapes (Orobanche and Phelipanche spp.) are root parasitic weeds that inflict major losses in agriculture globally. Being obligate parasitic flowering plants in nature, they parasitize other autotrophic plants of agricultural importance. The plants are attached to their host by means of haustoria, which transfer nutrients from the host to the parasite. Weeds reduce...

Researchers propose multi-aperture vertical cavity surface emitting lasers of varying size and shape

Vertical cavity surface emitting lasers (VCSELs) present the basis for large data rate optical interconnects in data centers. Presently VCSELs have replaced edge-emitting lasers for distances below 500 m due to their advantages such as on-wafer test possibility. The demand for VCSELs and in particular, arrays has most recently significantly increased due to the trend for wavelength multiplexing in...