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Download the A*STAR Research app now! | | | | | | | Jump to the content that matters to you | | | | | | | | Specials - Outlook: Obesity | | | | Given how common – and how dangerous – obesity is, it's amazing how little is known about the science underlying this condition. Why do some people seem predisposed to weight gain? And how does appetite actually work? Devising an effective strategy to combat the obesity epidemic will require the integration of insights from neuroscience, genetics and the behavioural sciences. ▼ more | | | | | | | | | The ensemble nature of allostery | The classic model for understanding allostery , the regulated process by which biological macromolecules (typically enzymes) transmit the effect of binding at one site to another with subsequent change in activity, has focused on the structural differences between the various functional forms. During the past 20 years there has been a realization that allostery is associated with changes in dynamics as well. This review discusses a new model that unifies the description of allosteric mechanisms from different systems. | | | | | | | | | Isotopic links between atmospheric chemistry and the deep sulphur cycle on Mars | A new sulphur isotope analysis of 40 Martian meteorites suggests an atmospheric sulphur chemistry, notably the photochemical processing preserved in meteoritic sulphide and sulphate, very different from what we see on Earth. The data provide evidence that the assimilation of sulphur into Martian magmas was common throughout much of the planet's history. The authors conclude that sulphur isotope systematics, used in conjunction with data for other isotopic systems and trace element characteristics, is a powerful tool for reconstructing the geological history of Mars. | | | | | | | | | Impressive thermoelectric performance from SnSe crystals | Thermoelectric materials hold promise as a practical means of converting waste heat into electrical energy, but the energy-conversion efficiency of existing materials is too low. The main obstacle to improving the thermoelectric efficiencies arises from the interdependence of electrical and thermal conductivity. Thermoelectric efficiency demands high electrical but low thermal conductivity. One route that might provide that combination is nanostructuring. Here Li-Dong Zhao and colleagues describe a simple layered crystalline material, tin selenide (SnSe), that appears to have these qualities built in. | | | | | | | | | | | | | In this week's podcast: how egg and sperm meet and greet each other, how the countryside benefits biodiversity, and harnessing the sun's power for the developing world. | | | | | | | | | | | | | | | | | | | | | | | | The democracy carousel ▶ | | | European law has allowed citizens to force a debate on human embryonic stem cells less than a year after the previous one. This fruitless democratic exercise has left scientists spinning in uncertainty. | | | | | | | | Cancer crossroads ▶ | | | Efforts to understand cancer genomes should take on a fresh focus. | | | | | | | | Practical nonsense ▶ | | | Downgrading practical science will impede UK students in the global workplace | | | | | | | | | | | | | | | | | Seven days: 11–17 April 2014 ▶ | | | The week in science: Japan reapproves use of nuclear power, second sighting of an exotic tetraquark, and biotech stocks plunge. | | | | | | | | | | | | | | | | | | | | IPCC report under fire ▶ | | | Critics attack panel’s lack of specific guidance on how countries should lower emissions. | | | | | | | | | | | | | | | | | | | | Toxicology: The plastics puzzle ▶ | | | When toxicologists warned that the plastics ingredient BPA might be harmful, consumers clamoured for something new. But problems persist. | | | | | | | | | | | | | | Publishing: Credit where credit is due ▶ | | | Liz Allen, Amy Brand, Jo Scott, Micah Altman and Marjorie Hlava are trialling digital taxonomies to help researchers to identify their contributions to collaborative projects. | | | | | | | | | | | Astronomy: Art of the eclipse ▶ | | | As the next solar eclipse approaches, Jay M. Pasachoff and Roberta J. M. Olson ponder how artists from the early Renaissance onwards have interpreted the phenomenon. | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Juno is the egg Izumo receptor and is essential for mammalian fertilization ▶ | | | Enrica Bianchi, Brendan Doe, David Goulding et al. | | | The egg receptor for Izumo, a sperm cell-surface protein required for male fertility, is identified here and renamed Juno; these findings show that the Izumo–Juno interaction is conserved within mammals, and open new opportunities for the development of fertility treatments and contraceptives. | | | | | | | | | | | | | | | | | Coordination of entorhinal–hippocampal ensemble activity during associative learning ▶ | | | Kei M. Igarashi, Li Lu, Laura L. Colgin et al. | | | Simultaneous recordings from hippocampus and entorhinal cortex in rats show that as the animals learn odour guidance cues during their exploration of two-dimensional space in the laboratory, ensembles of coherently firing neurons emerge in both locations, with cortical–hippocampal oscillatory coupling occurring in a specific range of the beta-gamma frequency band. | | | | | | | | Structural basis of Sec-independent membrane protein insertion by YidC ▶ | | | Kaoru Kumazaki, Shinobu Chiba, Mizuki Takemoto et al. | | | The crystal structure of the bacterial protein YidC is reported, together with a structure-based functional analysis, providing insight into the role of YidC in inserting single-spanning membrane proteins into the membrane. | | | | | | | | | | | Scalable control of mounting and attack by Esr1+ neurons in the ventromedial hypothalamus ▶ | | | Hyosang Lee, Dong-Wook Kim, Ryan Remedios et al. | | | Activation of Esr1+ neurons of the mouse ventromedial hypothalamus initiates graded social behavioural responses–weak activation triggers close investigation (sniffing) during a social encounter that often leads, with continued stimulation, to mounting behaviours by males towards either gender; mounting behaviour transitions to aggressive attacks with greater stimulation intensity. | | | | | | | | | | | Dynamics and associations of microbial community types across the human body ▶ | | | Tao Ding, Patrick D. Schloss | | | The microbiome composition of 300 individuals sampled over 12–18 months was partitioned into microbial community types, which could be associated with the type found at other body sites, as well as with whether individuals were breastfed as an infant, their gender and their level of education. | | | | | | | | A Palaeozoic shark with osteichthyan-like branchial arches ▶ | | | Alan Pradel, John G. Maisey, Paul Tafforeau et al. | | | A description of the gill skeleton of a very early fossil shark-like fish shows that it bears more resemblance to gill skeletons from bony fishes rather than to those from modern cartilaginous fishes, suggesting that modern sharks are not anatomically primitive, as previously thought. | | | | | | | | Oncogene-like induction of cellular invasion from centrosome amplification ▶ | | | Susana A. Godinho, Remigio Picone, Mithila Burute et al. | | | Cancer cells often have extra centrosomes, a paradox considering the detrimental effect extra centrosomes usually have on cell division; a study of human cells reveals that extra centrosomes can promote cancer cell invasion phenotypes through a pathway involving increased microtubule nucleation and Rac1 activity. | | | | | | | | | | | | | | Domains of genome-wide gene expression dysregulation in Down’s syndrome ▶ | | | Audrey Letourneau, Federico A. Santoni, Ximena Bonilla et al. | | | By studying the transcriptome of fetal cells of monozygotic twins discordant for trisomy 21, this paper finds that differential expression between the twins is organized in domains along all chromosomes; these gene expression dysregulation domains are conserved in the mouse model of Down’s syndrome and correlate with the lamina-associated domains and replication domains. | | | | | | | | Brainstem nucleus MdV mediates skilled forelimb motor tasks ▶ | | | Maria Soledad Esposito, Paolo Capelli, Silvia Arber | | | The authors use a combination of viral tracing and genetics to characterize the diversity of neurons projecting from mouse brainstem to motor neurons that control limb movements; in particular they discover that the medullary reticular formation ventral part (MdV) is functionally specialized for skilled forelimb motor control. | | | | | | | | Skilled reaching relies on a V2a propriospinal internal copy circuit ▶ | | | Eiman Azim, Juan Jiang, Bror Alstermark et al. | | | Cervical propriospinal neurons (PNs) form a genetically accessible subclass of V2a interneurons that convey both premotor output and precerebellar copy signals; their ablation in mice impairs reaching movements selectively, and activation of their internal copy projection recruits a rapid cerebellar feedback loop that modulates forelimb movement. | | | | | | | | A new fossil species supports an early origin for toothed whale echolocation ▶ | | | Jonathan H. Geisler, Matthew W. Colbert, James L. Carew | | | Phylogenetic analysis of a new species of fossil toothed whale, Cotylocara macei, from the Oligocene epoch places it in a basal clade of odontocetes, and its features suggest that rudimentary echolocation evolved in the early Oligocene and was followed by convergent evolution in their skulls. | | | | | | | | Rapid and tunable post-translational coupling of genetic circuits ▶ | | | Arthur Prindle, Jangir Selimkhanov, Howard Li et al. | | | Protease competition is used to produce rapid and tunable coupling of genetic circuits, enabling a coupled clock network that can encode independent environmental cues into a single time series output, a form of frequency multiplexing in a genetic circuit context. | | | | | | | | | | | A committed precursor to innate lymphoid cells ▶ | | | Michael G. Constantinides, Benjamin D. McDonald, Philip A. Verhoef et al. | | | A committed precursor to innate lymphoid cell lineages, but not classical natural killer and lymphoid tissue inducer cells, is derived from common lymphoid precursors and distinguished by high levels of expression of the transcription factor PLZF. | | | | | | | | | | | | | | miRNAs trigger widespread epigenetically activated siRNAs from transposons in Arabidopsis ▶ | | | Kate M. Creasey, Jixian Zhai, Filipe Borges et al. | | | The generation of widespread epigenetically activated short interfering RNAs by the targeting of microRNAs to transposon transcripts in Arabidopsis thaliana is shown to be a latent mechanism that only becomes active when the transcripts are epigenetically reactivated, for example, during reprogramming of the germ line. | | | | | | | | Structural basis for translocation by AddAB helicase–nuclease and its arrest at χ sites ▶ | | | Wojciech W. Krajewski, Xin Fu, Martin Wilkinson et al. | | | A dual-function helicase–nuclease, typified by RecBCD in Escherichia coli, acts on free DNA ends during bacterial double-stranded break repair until it reaches a χ sequence at which it pauses before continuing with modified enzymatic properties; here several crystal structures of the related AddAB enzyme from Bacillus subtilis bound to χ-containing DNA are presented, offering insight into χ recognition and its effect on DNA translocation. | | | | | | | | | | | The ensemble nature of allostery ▶ | | | Hesam N. Motlagh, James O. Wrabl, Jing Li et al. | | | Allostery is the process by which biological macromolecules transmit the effect of binding at one site to another, often distal, functional site, allowing for the regulation of activity; here facilitation of allostery through dynamic and intrinsically disordered proteins is discussed, and a framework to unify the description of allosteric mechanisms for different systems is proposed. | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Ubiquitin and ubiquitin-like proteins have central roles in regulating cellular processes and homeostasis. This Focus examines our understanding of the ubiquitination reaction and the mechanisms by which ubiquitin and related modifications affect key cellular functions. Produced with support from | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Enantioselective construction of remote quaternary stereocentres ▶ | | | Tian-Sheng Mei, Harshkumar H. Patel, Matthew S. Sigman | | | A catalytic and enantioselective intermolecular Heck-type reaction of trisubstituted-alkenyl alcohols with aryl boronic acids provides direct access to quaternary stereocentres remote from a carbonyl group. | | | | | | | | Isotopic links between atmospheric chemistry and the deep sulphur cycle on Mars ▶ | | | Heather B. Franz, Sang-Tae Kim, James Farquhar et al. | | | Isotopic analyses of 40 Martian meteorites indicate that assimilation of sulphur into Martian magmas was a common occurrence throughout much of the planet’s history and that the atmospheric imprint of photochemical processing preserved in Martian meteoritic sulphide and sulphate is distinct from that observed in terrestrial analogues. | | | | | | | | | | | Ultralow thermal conductivity and high thermoelectric figure of merit in SnSe crystals ▶ | | | Li-Dong Zhao, Shih-Han Lo, Yongsheng Zhang et al. | | | The main obstacle to improving the thermoelectric efficiency of a material arises from the common interdependence of electrical and thermal conductivity, whereas one ideally wants to raise the former while lowering the latter: a simple layered crystalline material — SnSe — is now reported that seems to have these qualities built in. | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Sea-level and deep-sea-temperature variability over the past 5.3 million years ▶ | | | E. J. Rohling, G. L. Foster, K. M. Grant et al. | | | A novel approach to the estimation of sea level and deep-sea temperature has been used to determine these quantities over the past 5.3 million years; this approach, based on oxygen isotope records from the eastern Mediterranean, shows that temperature and sea-level histories are broadly correlated but also show intriguing temporal offsets. | | | | | | | | | | | Isotopic links between atmospheric chemistry and the deep sulphur cycle on Mars ▶ | | | Heather B. Franz, Sang-Tae Kim, James Farquhar et al. | | | Isotopic analyses of 40 Martian meteorites indicate that assimilation of sulphur into Martian magmas was a common occurrence throughout much of the planet’s history and that the atmospheric imprint of photochemical processing preserved in Martian meteoritic sulphide and sulphate is distinct from that observed in terrestrial analogues. | | | | | | | | Mid-latitude interhemispheric hydrologic seesaw over the past 550,000 years ▶ | | | Kyoung-nam Jo, Kyung Sik Woo, Sangheon Yi et al. | | | Tropical and subtropical speleothems show that the latitudinal migration of the Intertropical Convergence Zone tends to produce increased precipitation in one hemisphere and drying in the other; now it is shown using speleothems from the Korean peninsula that this phenomenon extended to the mid-latitudes during the past 550,000 years. | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Public health: Society at large ▶ | | | The increasing prevalence of obesity is a worldwide phenomenon, affecting peoples from diverse cultural and economic backgrounds. By Tony Scully. | | | | | | | | | | | Treatment: Marginal gains ▶ | | | Behavioural interventions work, but not for everyone, and weight regain is common. Are there better ways to treat obesity? | | | | | | | | | | | Heritability: The family roots of obesity ▶ | | | Scores of genes are implicated in obesity, but they cannot account for a family's predisposition to obesity. Are there other ways parents can influence their children? | | | | | | | | | | | | | | Perspective: Tricks of the trade ▶ | | | Processed foods that dilute protein content subvert our appetite control systems, say Stephen J. Simpson and David Raubenheimer. | | | | | | | | | | | | | | | nature.com webcasts
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