Science news

• [Working Life] Choosing the hard road

  12-01-2017 23:18
  Author: Katharina Henke
  
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• [This Week in Science] Three strands ironed closely together

  12-01-2017 23:18
  Author: Jake Yeston
  
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• [This Week in Science] TAMpering with tumors

  12-01-2017 23:18
  Author: Angela Colmone
  
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• [This Week in Science] Squeezing out the oddness

  12-01-2017 23:18
  Author: Jelena Stajic
  
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• [This Week in Science] Soil biota and plant diversity

  12-01-2017 23:18
  Author: Andrew M. Sugden
  
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• [This Week in Science] Redox metabolite role in biofilms

  12-01-2017 23:18
  Author: Caroline Ash
  
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• [This Week in Science] Prions enter another domain of life

  12-01-2017 23:18
  Author: Stella M. Hurtley
  
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• [This Week in Science] Poised for the second step of splicing

  12-01-2017 23:18
  Author: Valda Vinson
  
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• [This Week in Science] Pin the tail on the hydrogens

  12-01-2017 23:18
  Author: Marc S. Lavine
  
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• [This Week in Science] Phages build themselves a wall

  12-01-2017 23:18
  Author: Stella M. Hurtley
  
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• [This Week in Science] Parallel computation in memory-making

  12-01-2017 23:18
  Author: Peter Stern
  
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• [This Week in Science] More light on dopamine receptors

  12-01-2017 23:18
  Author: Philip Yeagle
  
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• [This Week in Science] Initiating an antitumor attack

  12-01-2017 23:18
  Author: Yevgeniya Nusinovich
  
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• [This Week in Science] Inducing strong coupling

  12-01-2017 23:18
  Author: Ian S. Osborne
  
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• [This Week in Science] How to get to place B

  12-01-2017 23:18
  Author: Peter Stern
  
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• [This Week in Science] Faster tree growth is no panacea

  12-01-2017 23:18
  Author: Julia Fahrenkamp-Uppenbrink
  
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• [This Week in Science] Designing proteins with cavities

  12-01-2017 23:18
  Author: Valda Vinson
  
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• [This Week in Science] Channeling pain through GPCRs

  12-01-2017 23:18
  Author: Nancy R. Gough
  
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• [This Week in Science] Better living through water-splitting

  12-01-2017 23:18
  Author: Jake Yeston
  
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• [This Week in Science] Are you aware how well you remember?

  12-01-2017 23:18
  Author: Peter Stern
  
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• [This Week in Science] A machine for building ribosomes

  12-01-2017 23:18
  Author: Guy Riddihough
  
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• [This Week in Science] A cyclic catalyst to pair up sugars

  12-01-2017 23:18
  Author: Jake Yeston
  
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• [Technical Response] Response to Comment on “Ribose and related sugars from ultraviolet irradiation of interstellar ice analogs”

  12-01-2017 23:18
  We detected ribose and related sugars in the organic residues of simulated interstellar ices using multidimensional gas chromatography. Kawai questions the formation of sugar compounds in the ices and suggests that they arise from a classical formose reaction during sample workup for analysis. We disagree with this hypothesis and present additional data to argue that Kawai’s criticism does not apply.
  Authors: Cornelia Meinert, Iuliia Myrgorodska, Pierre de Marcellus, Thomas Buhse, Laurent Naho
  
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• [Technical Comment] Comment on “Ribose and related sugars from ultraviolet irradiation of interstellar ice analogs”

  12-01-2017 23:18
  Meinert et al. (Reports, 8 April 2016, p. 208) reported the formation of prebiotic molecules, including ribose, in an interstellar ice analog experiment. We show that if their experimental procedure is accurately described, much or most of their products may have been formed during their analysis process, not in the parent ice.
  Author: Jun Kawai
  
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• [Review] Combining theory and experiment in electrocatalysis: Insights into materials design

  12-01-2017 23:18
  Electrocatalysis plays a central role in clean energy conversion, enabling a number of sustainable processes for future technologies. This review discusses design strategies for state-of-the-art heterogeneous electrocatalysts and associated materials for several different electrochemical transformations involving water, hydrogen, and oxygen, using theory as a means to rationalize catalyst performance. By examining the common principles that govern catalysis for different electrochemical reaction
  
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• [Research Article] Structure of a yeast step II catalytically activated spliceosome

  12-01-2017 23:18
  Each cycle of precursor messenger RNA (pre-mRNA) splicing comprises two sequential reactions, first freeing the 5′ exon and generating an intron lariat–3′ exon and then ligating the two exons and releasing the intron lariat. The second reaction is executed by the step II catalytically activated spliceosome (known as the C* complex). Here, we present the cryo–electron microscopy structure of a C* complex from Saccharomyces cerevisiae at an average resolution of 4.0 angstroms. Compared wit
  
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• [Research Article] Strong peak in Tc of Sr2RuO4 under uniaxial pressure

  12-01-2017 23:18
  Sr2RuO4 is an unconventional superconductor that has attracted widespread study because of its high purity and the possibility that its superconducting order parameter has odd parity. We study the dependence of its superconductivity on anisotropic strain. Applying uniaxial pressures of up to ~1 gigapascals along a 〈100〉 direction (a axis) of the crystal lattice results in the transition temperature (Tc) increasing from 1.5 kelvin in the unstrained material to 3.4 kelvin at compression by ≈
  
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• [Research Article] Architecture of the yeast small subunit processome

  12-01-2017 23:18
  The small subunit (SSU) processome, a large ribonucleoprotein particle, organizes the assembly of the eukaryotic small ribosomal subunit by coordinating the folding, cleavage, and modification of nascent pre–ribosomal RNA (rRNA). Here, we present the cryo–electron microscopy structure of the yeast SSU processome at 5.1-angstrom resolution. The structure reveals how large ribosome biogenesis complexes assist the 5′ external transcribed spacer and U3 small nucleolar RNA in providing an inter
  
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• [Report] Vectorial representation of spatial goals in the hippocampus of bats

  12-01-2017 23:18
  To navigate, animals need to represent not only their own position and orientation, but also the location of their goal. Neural representations of an animal’s own position and orientation have been extensively studied. However, it is unknown how navigational goals are encoded in the brain. We recorded from hippocampal CA1 neurons of bats flying in complex trajectories toward a spatial goal. We discovered a subpopulation of neurons with angular tuning to the goal direction. Many of these neuron
  
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• [Report] Superficial layers of the medial entorhinal cortex replay independently of the hippocampus

  12-01-2017 23:18
  The hippocampus is thought to initiate systems-wide mnemonic processes through the reactivation of previously acquired spatial and episodic memory traces, which can recruit the entorhinal cortex as a first stage of memory redistribution to other brain areas. Hippocampal reactivation occurs during sharp wave–ripples, in which synchronous network firing encodes sequences of places. We investigated the coordination of this replay by recording assembly activity simultaneously in the CA1 region of
  
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• [Report] Strong coupling of a single electron in silicon to a microwave photon

  12-01-2017 23:18
  Silicon is vital to the computing industry because of the high quality of its native oxide and well-established doping technologies. Isotopic purification has enabled quantum coherence times on the order of seconds, thereby placing silicon at the forefront of efforts to create a solid-state quantum processor. We demonstrate strong coupling of a single electron in a silicon double quantum dot to the photonic field of a microwave cavity, as shown by the observation of vacuum Rabi splitting. Strong
  
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• [Report] Pyocyanin degradation by a tautomerizing demethylase inhibits Pseudomonas aeruginosa biofilms

  12-01-2017 23:18
  The opportunistic pathogen Pseudomonas aeruginosa produces colorful redox-active metabolites called phenazines, which underpin biofilm development, virulence, and clinical outcomes. Although phenazines exist in many forms, the best studied is pyocyanin. Here, we describe pyocyanin demethylase (PodA), a hitherto uncharacterized protein that oxidizes the pyocyanin methyl group to formaldehyde and reduces the pyrazine ring via an unusual tautomerizing demethylation reaction. Treatment with PodA dis
  
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• [Report] Principles for designing proteins with cavities formed by curved β sheets

  12-01-2017 23:18
  Active sites and ligand-binding cavities in native proteins are often formed by curved β sheets, and the ability to control β-sheet curvature would allow design of binding proteins with cavities customized to specific ligands. Toward this end, we investigated the mechanisms controlling β-sheet curvature by studying the geometry of β sheets in naturally occurring protein structures and folding simulations. The principles emerging from this analysis were used to design, de novo, a series of pr
  
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• [Report] Plant-soil feedback and the maintenance of diversity in Mediterranean-climate shrublands

  12-01-2017 23:18
  Soil biota influence plant performance through plant-soil feedback, but it is unclear whether the strength of such feedback depends on plant traits and whether plant-soil feedback drives local plant diversity. We grew 16 co-occurring plant species with contrasting nutrient-acquisition strategies from hyperdiverse Australian shrublands and exposed them to soil biota from under their own or other plant species. Plant responses to soil biota varied according to their nutrient-acquisition strategy,
  
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• [Report] Macrocyclic bis-thioureas catalyze stereospecific glycosylation reactions

  12-01-2017 23:18
  Carbohydrates are involved in nearly all aspects of biochemistry, but their complex chemical structures present long-standing practical challenges to their synthesis. In particular, stereochemical outcomes in glycosylation reactions are highly dependent on the steric and electronic properties of coupling partners; thus, carbohydrate synthesis is not easily predictable. Here we report the discovery of a macrocyclic bis-thiourea derivative that catalyzes stereospecific invertive substitution pathw
  
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• [Report] Hydrogen positions in single nanocrystals revealed by electron diffraction

  12-01-2017 23:18
  The localization of hydrogen atoms is an essential part of crystal structure analysis, but it is difficult because of their small scattering power. We report the direct localization of hydrogen atoms in nanocrystalline materials, achieved using the recently developed approach of dynamical refinement of precession electron diffraction tomography data. We used this method to locate hydrogen atoms in both an organic (paracetamol) and an inorganic (framework cobalt aluminophosphate) material. The re
  
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• [Report] Causal neural network of metamemory for retrospection in primates

  12-01-2017 23:18
  We know how confidently we know: Metacognitive self-monitoring of memory states, so-called “metamemory,” enables strategic and efficient information collection based on past experiences. However, it is unknown how metamemory is implemented in the brain. We explored causal neural mechanism of metamemory in macaque monkeys performing metacognitive confidence judgments on memory. By whole-brain searches via functional magnetic resonance imaging, we discovered a neural correlate of metamemory fo
  
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• [Report] Braiding a molecular knot with eight crossings

  12-01-2017 23:18
  Knots may ultimately prove just as versatile and useful at the nanoscale as at the macroscale. However, the lack of synthetic routes to all but the simplest molecular knots currently prevents systematic investigation of the influence of knotting at the molecular level. We found that it is possible to assemble four building blocks into three braided ligand strands. Octahedral iron(II) ions control the relative positions of the three strands at each crossing point in a circular triple helicate, wh
  
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• [Report] Assembly of a nucleus-like structure during viral replication in bacteria

  12-01-2017 23:18
  We observed the assembly of a nucleus-like structure in bacteria during viral infection. Using fluorescence microscopy and cryo-electron tomography, we showed that Pseudomonas chlororaphis phage 201φ2-1 assembled a compartment that separated viral DNA from the cytoplasm. The phage compartment was centered by a bipolar tubulin-based spindle, and it segregated phage and bacterial proteins according to function. Proteins involved in DNA replication and transcription localized inside the compartmen
  
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• [Report] A bacterial global regulator forms a prion

  12-01-2017 23:18
  Prions are self-propagating protein aggregates that act as protein-based elements of inheritance in fungi. Although prevalent in eukaryotes, prions have not been identified in bacteria. Here we found that a bacterial protein, transcription terminator Rho of Clostridium botulinum (Cb-Rho), could form a prion. We identified a candidate prion-forming domain (cPrD) in Cb-Rho and showed that it conferred amyloidogenicity on Cb-Rho and could functionally replace the PrD of a yeast prion-forming protei
  
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• [Policy Forum] The irreversible momentum of clean energy

  12-01-2017 23:18
  The release of carbon dioxide (CO2) and other greenhouse gases (GHGs) due to human activity is increasing global average surface air temperatures, disrupting weather patterns, and acidifying the ocean (1). Left unchecked, the continued growth of GHG emissions could cause global average temperatures to increase by another 4°C or more by 2100 and by 1.5 to 2 times as much in many midcontinent and far northern locations (1). Although our understanding of the impacts of climate change is increasing
  
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• [Perspective] Putting the squeeze on superconductivity

  12-01-2017 23:18
  Superconductivity is a fascinating quantum state of matter that has captured the imagination of physicists for over a century. The pioneering theoretical work of Bardeen, Cooper, and Schrieffer described the superconducting state as a phase-coherent condensate of electrons bound into Cooper pairs, whose distinguishing hallmark, the order parameter, reflects the symmetry of the pair wave function. According to the laws of quantum mechanics, the wave function describing a pair of electrons must po
  
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• [Perspective] Multiple mechanisms for memory replay?

  12-01-2017 23:18
  Cast your mind back to your childhood. A stream of mental images of events and places appears, like photographs in an album. How do our brains capture and preserve these episodes, and then vividly recall them at will many years later? On page 184 of this issue, O'Neill et al. (1) show that a region of the brain called the medial entorhinal cortex can replay waking experiences. Their work thus challenges the prevailing view that the hippocampus is the sole initiator of spatial and episodic memory
  
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• [Perspective] Electron diffraction and the hydrogen atom

  12-01-2017 23:18
  The humble hydrogen atom, with just a single proton and a single electron, is the key to many chemical and biological processes, but precisely because of its low number of electrons, it is difficult to detect even in a single-crystal x-ray diffraction (XRD) experiment. If the material is polycrystalline (crystal volume <100 µm3) and only powder-diffraction techniques can be applied, detection becomes almost hopeless unless sophisticated neutron-diffraction experiments are performed on c
  
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• [Perspective] Belowground drivers of plant diversity

  12-01-2017 23:18
  Long before Ernst Haeckel coined the term “ecology” in 1866, nature explorers, such as Alexander von Humboldt, observed that vegetation composition changes with climate. However, it still remains unclear what determines the local composition and species richness of vegetation. Understanding the roles of belowground invertebrates and microbes is particularly challenging. On pages 173 and 181 of this issue, respectively, Teste et al. (1) and Bennett et al. (2) report field studies that elucida
  
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• [Perspective] A matter of tree longevity

  12-01-2017 23:18
  There is much scientific and political interest in using the transfer of carbon from the atmosphere to the biosphere, or carbon sequestration, to help mitigate the greenhouse effect (1). Because plants fix carbon dioxide (CO2) by photosynthesis and store carbon in their body (close to half of plant dry matter is carbon), faster carbon uptake by plants through faster growth is widely held to increase carbon sequestration. Yet, this assumption is supported by neither theory nor evidence. Any gain
  
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• [Letter] Pipelines imperil Canada's ecosystem

  12-01-2017 23:18
  Authors: Juan José Alava, Nastenka Calle
  
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• [Letter] Europe's biodiversity avoids fatal setback

  12-01-2017 23:18
  Authors: Arie Trouwborst, Guillaume Chapron, Floor Fleurke, Yaffa Epstein, José Vicente López-Bao
  
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• [Letter] A big, bug science party

  12-01-2017 23:18
  Author: Cara M. Gibson
  
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• [In Depth] Pioneering study images activity in fetal brains

  12-01-2017 23:18
  Babies born prematurely are prone to problems later in life—they're more likely to develop autism or attention deficit hyperactivity disorder, and more likely to struggle in school. A new study that's among the first to investigate brain activity in human fetuses suggests that the underlying neurological issues may begin in the womb. The research, led by Moriah Thomason, a developmental neuroscientist at Wayne State University School of Medicine in Detroit, Michigan, and published this week in
  
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