Science news

• [Working Life] The America I believe in

  16-02-2017 23:17
  Author: Hilal A. Lashuel
  
  Read more

• [This Week in Science] When is a mutation a true genetic variant?

  16-02-2017 23:17
  Author: Laura M. Zahn
  
  Read more

• [This Week in Science] Vitamin B3 protects mice from glaucoma

  16-02-2017 23:17
  Author: Priscilla Kelly
  
  Read more

• [This Week in Science] Understanding insulin release

  16-02-2017 23:17
  Author: Stella M. Hurtley
  
  Read more

• Advertisement

• [This Week in Science] Touchdown for gut pathogen virulence

  16-02-2017 23:17
  Author: Caroline Ash
  
  Read more

• [This Week in Science] Sugar rush

  16-02-2017 23:17
  Author: Sacha Vignieri
  
  Read more

• [This Week in Science] Stamping hydrogen into metal

  16-02-2017 23:17
  Author: Brent Grocholski
  
  Read more

• [This Week in Science] Peak HIV viremia pushes CD8+ T cells

  16-02-2017 23:17
  Author: Lindsey Pujanandez
  
  Read more

• Advertisement

• [This Week in Science] Passivating traps in perovskites

  16-02-2017 23:17
  Author: Phil Szuromi
  
  Read more

• [This Week in Science] Organic compounds detected on Ceres

  16-02-2017 23:17
  Author: Keith T. Smith
  
  Read more

• [This Week in Science] Missing meadows fail to mop up microbes

  16-02-2017 23:17
  Author: Caroline Ash
  
  Read more

• [This Week in Science] Hypoxic conditioning of immune cells

  16-02-2017 23:17
  Author: Angela Colmone
  
  Read more

• [This Week in Science] Hydroamination gets a light push uphill

  16-02-2017 23:17
  Author: Jake Yeston
  
  Read more

• [This Week in Science] Host-pathogen point-counterpoint

  16-02-2017 23:17
  Author: Pamela J. Hines
  
  Read more

• [This Week in Science] Hair follicles: Secret to prevent scars?

  16-02-2017 23:17
  Author: Beverly A. Purnell
  
  Read more

• [This Week in Science] Coordinating cell wall synthesis and cell division

  16-02-2017 23:17
  Author: Stella M. Hurtley
  
  Read more

• [This Week in Science] Being selective in fighting infection

  16-02-2017 23:17
  Author: Julia Fahrenkamp-Uppenbrink
  
  Read more

• [This Week in Science] An encephalitis-boosting microRNA

  16-02-2017 23:17
  Author: John F. Foley
  
  Read more

• [Research Article] Observation of the Wigner-Huntington transition to metallic hydrogen

  16-02-2017 23:17
  Producing metallic hydrogen has been a great challenge in condensed matter physics. Metallic hydrogen may be a room-temperature superconductor and metastable when the pressure is released and could have an important impact on energy and rocketry. We have studied solid molecular hydrogen under pressure at low temperatures. At a pressure of 495 gigapascals, hydrogen becomes metallic, with reflectivity as high as 0.91. We fit the reflectance using a Drude free-electron model to determine the plasma
  
  Read more

• [Research Article] Lipid transport by TMEM24 at ER–plasma membrane contacts regulates pulsatile insulin secretion

  16-02-2017 23:17
  Insulin is released by β cells in pulses regulated by calcium and phosphoinositide signaling. Here, we describe how transmembrane protein 24 (TMEM24) helps coordinate these signaling events. We showed that TMEM24 is an endoplasmic reticulum (ER)–anchored membrane protein whose reversible localization to ER-plasma membrane (PM) contacts is governed by phosphorylation and dephosphorylation in response to oscillations in cytosolic calcium. A lipid-binding module in TMEM24 transports the phosphat
  
  Read more

• [Research Article] A paralogous decoy protects Phytophthora sojae apoplastic effector PsXEG1 from a host inhibitor

  16-02-2017 23:17
  The extracellular space (apoplast) of plant tissue represents a critical battleground between plants and attacking microbes. Here we show that a pathogen-secreted apoplastic xyloglucan-specific endoglucanase, PsXEG1, is a focus of this struggle in the Phytophthora sojae–soybean interaction. We show that soybean produces an apoplastic glucanase inhibitor protein, GmGIP1, that binds to PsXEG1 to block its contribution to virulence. P. sojae, however, secretes a paralogous PsXEG1-like protein, Ps
  
  Read more

• [Report] Vitamin B3 modulates mitochondrial vulnerability and prevents glaucoma in aged mice

  16-02-2017 23:17
  Glaucomas are neurodegenerative diseases that cause vision loss, especially in the elderly. The mechanisms initiating glaucoma and driving neuronal vulnerability during normal aging are unknown. Studying glaucoma-prone mice, we show that mitochondrial abnormalities are an early driver of neuronal dysfunction, occurring before detectable degeneration. Retinal levels of nicotinamide adenine dinucleotide (NAD+, a key molecule in energy and redox metabolism) decrease with age and render aging neuron
  
  Read more

• [Report] Treadmilling by FtsZ filaments drives peptidoglycan synthesis and bacterial cell division

  16-02-2017 23:17
  The mechanism by which bacteria divide is not well understood. Cell division is mediated by filaments of FtsZ and FtsA (FtsAZ) that recruit septal peptidoglycan-synthesizing enzymes to the division site. To understand how these components coordinate to divide cells, we visualized their movements relative to the dynamics of cell wall synthesis during cytokinesis. We found that the division septum was built at discrete sites that moved around the division plane. FtsAZ filaments treadmilled circumf
  
  Read more

• [Report] Seagrass ecosystems reduce exposure to bacterial pathogens of humans, fishes, and invertebrates

  16-02-2017 23:17
  Plants are important in urban environments for removing pathogens and improving water quality. Seagrass meadows are the most widespread coastal ecosystem on the planet. Although these plants are known to be associated with natural biocide production, they have not been evaluated for their ability to remove microbiological contamination. Using amplicon sequencing of the 16S ribosomal RNA gene, we found that when seagrass meadows are present, there was a 50% reduction in the relative abundance of
  
  Read more

• [Report] Regeneration of fat cells from myofibroblasts during wound healing

  16-02-2017 23:17
  Although regeneration through the reprogramming of one cell lineage to another occurs in fish and amphibians, it has not been observed in mammals. We discovered in the mouse that during wound healing, adipocytes regenerate from myofibroblasts, a cell type thought to be differentiated and nonadipogenic. Myofibroblast reprogramming required neogenic hair follicles, which triggered bone morphogenetic protein (BMP) signaling and then activation of adipocyte transcription factors expressed during dev
  
  Read more

• [Report] Localized aliphatic organic material on the surface of Ceres

  16-02-2017 23:17
  Organic compounds occur in some chondritic meteorites, and their signatures on solar system bodies have been sought for decades. Spectral signatures of organics have not been unambiguously identified on the surfaces of asteroids, whereas they have been detected on cometary nuclei. Data returned by the Visible and InfraRed Mapping Spectrometer on board the Dawn spacecraft show a clear detection of an organic absorption feature at 3.4 micrometers on dwarf planet Ceres. This signature is characteri
  
  Read more

• [Report] Host cell attachment elicits posttranscriptional regulation in infecting enteropathogenic bacteria

  16-02-2017 23:17
  The mechanisms by which pathogens sense the host and respond by remodeling gene expression are poorly understood. Enteropathogenic Escherichia coli (EPEC), the cause of severe intestinal infection, employs a type III secretion system (T3SS) to inject effector proteins into intestinal epithelial cells. These effectors subvert host cell processes to promote bacterial colonization. We show that the T3SS also functions to sense the host cell and to trigger in response posttranscriptional remodeling
  
  Read more

• [Report] Hawkmoths use nectar sugar to reduce oxidative damage from flight

  16-02-2017 23:17
  Nectar-feeding animals have among the highest recorded metabolic rates. High aerobic performance is linked to oxidative damage in muscles. Antioxidants in nectar are scarce to nonexistent. We propose that nectarivores use nectar sugar to mitigate the oxidative damage caused by the muscular demands of flight. We found that sugar-fed moths had lower oxidative damage to their flight muscle membranes than unfed moths. Using respirometry coupled with δ13C analyses, we showed that moths generate anti
  
  Read more

• [Report] GTPase activity–coupled treadmilling of the bacterial tubulin FtsZ organizes septal cell wall synthesis

  16-02-2017 23:17
  The bacterial tubulin FtsZ is the central component of the cell division machinery, coordinating an ensemble of proteins involved in septal cell wall synthesis to ensure successful constriction. How cells achieve this coordination is unknown. We found that in Escherichia coli cells, FtsZ exhibits dynamic treadmilling predominantly determined by its guanosine triphosphatase activity. The treadmilling dynamics direct the processive movement of the septal cell wall synthesis machinery but do not li
  
  Read more

• [Report] Efficient and stable solution-processed planar perovskite solar cells via contact passivation

  16-02-2017 23:17
  Planar perovskite solar cells (PSCs) made entirely via solution processing at low temperatures (<150°C) offer promise for simple manufacturing, compatibility with flexible substrates, and perovskite-based tandem devices. However, these PSCs require an electron-selective layer that performs well with similar processing. We report a contact-passivation strategy using chlorine-capped TiO2 colloidal nanocrystal film that mitigates interfacial recombination and improves interface binding in lo
  
  Read more

• [Report] DNA damage is a pervasive cause of sequencing errors, directly confounding variant identification

  16-02-2017 23:17
  Mutations in somatic cells generate a heterogeneous genomic population and may result in serious medical conditions. Although cancer is typically associated with somatic variations, advances in DNA sequencing indicate that cell-specific variants affect a number of phenotypes and pathologies. Here, we show that mutagenic damage accounts for the majority of the erroneous identification of variants with low to moderate (1 to 5%) frequency. More important, we found signatures of damage in most seque
  
  Read more

• [Report] Catalytic intermolecular hydroaminations of unactivated olefins with secondary alkyl amines

  16-02-2017 23:17
  The intermolecular hydroamination of unactivated alkenes with simple dialkyl amines remains an unsolved problem in organic synthesis. We report a catalytic protocol for efficient additions of cyclic and acyclic secondary alkyl amines to a wide range of alkyl olefins with complete anti-Markovnikov regioselectivity. In this process, carbon-nitrogen bond formation proceeds through a key aminium radical cation intermediate that is generated via electron transfer between an excited-state iridium phot
  
  Read more

• [Policy Forum] Ensuring scientific integrity in the Age of Trump

  16-02-2017 23:17
  With the new Donald J. Trump Administration comes uncertainty in the role that science will play in the U.S. federal government. Early indications that the Administration plans to distort or disregard science and evidence, coupled with the chaos and confusion occurring within federal agencies, now imperil the effectiveness of our government. Evidence from the past 20 years demonstrates that, when faced with such threats, supporters of science can take steps to protect the integrity of science in
  
  Read more

• [Policy Forum] CRISPR, surrogate licensing, and scientific discovery

  16-02-2017 23:17
  Several institutions are embroiled in a legal dispute over the foundational patent rights to CRISPR-Cas9 gene-editing technology, and it may take years for their competing claims to be resolved (1–4). But even before ownership of the patents is finalized, the institutions behind CRISPR have wasted no time capitalizing on the huge market for this groundbreaking technology by entering into a series of license agreements with commercial enterprises (see the figure). With respect to the potentiall
  
  Read more

• [Perspective] Sweet relief for pollinators

  16-02-2017 23:17
  During the first half of Earth's history, oxygen supplies were scant. Photosynthesis probably evolved soon after the appearance of life, but it was not until 2.4 to 2.1 billion years ago that photosynthetic organisms invented the ability to use water as an electron donor and began to produce molecular oxygen (O2) as a waste product. The production of O2 and its accumulation in the atmosphere facilitated the evolution of complex multicellular organisms; there are no exclusively anaerobic multicel
  
  Read more

• [Perspective] Relief for retinal neurons under pressure

  16-02-2017 23:17
  Advancing age predisposes us to a number of neurodegenerative diseases, yet the underlying mechanisms are poorly understood. With some 70 million individuals affected, glaucoma is the world's leading cause of irreversible blindness. Glaucoma is characterized by the selective loss of retinal ganglion cells that convey visual messages from the photoreceptive retina to the brain. Age is a major risk factor for glaucoma, with disease incidence increasing near exponentially with increasing age. Treat
  
  Read more

• [Perspective] Oliver Smithies (1925–2017)

  16-02-2017 23:17
  Oliver Smithies passed away on 10 January 2017, at the age of 91, in Chapel Hill, North Carolina. On that day, the world lost a legendary scientist, and I lost a colleague, collaborator, and friend. Smithies began his career as a physical biochemist and transitioned into genetics, earning a share of a Nobel Prize for his work in 2007. His interests and talents were wide ranging. In addition to his research, he rode motorcycles as a young man, sang in professional choirs throughout his life, and
  
  Read more

• [Perspective] Illuminating amination

  16-02-2017 23:17
  Amines, molecules containing carbon-nitrogen (C–N) bonds, are among the most common and biologically important molecules in organic chemistry; 84% of small-molecule pharmaceuticals contain at least one C–N bond (1). Hydroamination, the direct addition of an N–H bond across a carbon-carbon double or triple bond, represents an ideal approach for the synthesis of amines (2). Despite extensive research over the past several decades, the efficient and direct intermolecular hydroamination of una
  
  Read more

• [Perspective] Fighting the enemy within

  16-02-2017 23:17
  The dynamic microbiota that populate all human body surfaces affect health and disease in complex and often subtle ways. At the same time, human gastrointestinal and respiratory tract microbiota are the reservoirs for most of the human pathogens that cause invasive bacterial infections. Antibiotic resistance in such pathogens has dramatically increased in recent years, resulting in infections that are much more difficult to treat (1, 2). To counter this rise, research and development efforts mus
  
  Read more

• [Perspective] Fibroblasts become fat to reduce scarring

  16-02-2017 23:17
  Following cutaneous injury in adult mammals, one of two outcomes can occur: successful healing with scar formation or nonsuccessful healing and a chronic wound. In humans, scar formation can be classified in terms of “normal scar” formation versus pathologically increased fibrosis, as seen in hypertrophic scarring and keloids (1). Although scarring does not look or function like surrounding unwounded skin, it allows one to survive injury (and hence, procreate). However, extensive scarring fr
  
  Read more

• [Perspective] Dwarf planet Ceres and the ingredients of life

  16-02-2017 23:17
  A fundamental question in the evolution of the early Earth is the origin of the oceans and of some of the organic molecules that were required for the formation of life. Earth formed in the protoplanetary disk, a mixture of gas and dust. At the location of Earth, temperatures were too high for water vapor and some more volatile organic components to condense. This led to the idea that those materials may have been delivered to Earth by asteroids and/or comets from the outer solar system. Recent
  
  Read more

• [Letter] U.S. immigration ban undermines scientists

  16-02-2017 23:17
  Author: Mohamed Hassan
  
  Read more

• [Letter] Maternal antibodies' role in immunity—Response

  16-02-2017 23:17
  Authors: Katelyn M. Gostic, Monique Ambrose, Michael Worobey, James O. Lloyd-Smith
  
  Read more

• [Letter] Maternal antibodies' role in immunity

  16-02-2017 23:17
  Author: Hilmar Lemke
  
  Read more

• [In Depth] Parasitic worm may trigger mystery nodding syndrome

  16-02-2017 23:17
  Between 1990 and 2013, thousands of children in war-torn South Sudan and northern Uganda suddenly developed a severe and puzzling form of epilepsy. When exposed to food or cold temperatures, affected children nodded their heads uncontrollably. Over time the seizures often worsened, leaving the children severely disabled. Many died of malnutrition, accidents, or secondary infections. The outbreak triggered an intense hunt for the cause, but searches for viruses, bacteria, environmental toxins, ge
  
  Read more

• [In Depth] Failed spinal cord trial offers cautionary tale

  16-02-2017 23:17
  Eight months after cell therapy company StemCells Inc. announced the failure of its closely watched clinical trial for spinal cord injury, some of the company's longtime academic collaborators have come forward with disheartening animal data—and an admonition for future trials. Researchers at the University of California, Irvine, found no benefit to the company's human neural stem cell product, derived from fetal tissue, in mice with damage to the upper spine. In a paper published this week in
  
  Read more

• [In Depth] European gravitational wave detector falters

  16-02-2017 23:17
  On 20 February, dignitaries will descend on Virgo, Europe's premier gravitational wave detector near Pisa, Italy, for a dedication ceremony to celebrate a 5-year, €24 million upgrade. But the pomp will belie nagging problems that are likely to keep Virgo from joining its U.S. counterpart, the Laser Interferometer Gravitational-Wave Observatory (LIGO), in a hunt for gravitational wave sources that was meant to start next month. What has hobbled the 3-kilometer-long observatory: glass threads ju
  
  Read more

• [In Depth] Easier cure for resistant TB

  16-02-2017 23:17
  A new treatment strategy has had astonishing success against extensively drug-resistant tuberculosis (XDR TB), which kills more than 70% of patients. XDR and other drug-resistant forms of TB are burgeoning among people with HIV, and current treatments are so prolonged and toxic that many patients fail to adhere to them. But a small study now shows that a simpler, safer regimen can cure the disease. Called Nix-TB, the trial has had 34 people in South Africa with XDR on three antibiotics that hav
  
  Read more

• [In Depth] Drop in foreign applicants worries engineering schools

  16-02-2017 23:17
  Amid the uncertainty over U.S. immigration policy, one fact is sending a chill through U.S. higher education: Some U.S. graduate programs in engineering, Science has learned, are seeing a sharp drop this year in the number of applications from international students. University administrators worry that the declines, as much as 30% from 2016 levels in some programs, reflect heightened fears among foreign-born students that the United States is tightening its borders. Given the timing, the offici
  
  Read more

• [In Depth] Demise of stream rule won't revitalize coal industry

  16-02-2017 23:17
  Environmentalists were outraged earlier this month after the Republican-led Congress used an obscure law to erase a new regulation aimed at reducing the environmental damage caused by coal mining. The votes to undo the so-called stream protection rule, released last month on President Barack Obama's last day in office, were "a disgraceful opening salvo from this Congress, as they begin to try and do the bidding of big polluters," Michael Brune, executive director of the San Francisco,
  
  Read more

Follow @ScienceUKnews on Twitter!