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The daughter you've always wanted

Nature - Wed, 10/04/2017 - 00:00

The daughter you've always wanted

Nature 550, 7674 (2017). doi:10.1038/550150a

Author: Steve Pantazis

Family matters.

Categories: Literature

Women's Health

Nature - Wed, 10/04/2017 - 00:00

Women's Health

Nature. doi:10.1038/550S1a

Author: Michelle Grayson

Categories: Literature

Sexual arousal: Sex matters

Nature - Wed, 10/04/2017 - 00:00

Sexual arousal: Sex matters

Nature. doi:10.1038/550S2a

Author: Anna Petherick

Research on women's sexual desire and satisfaction lags behind that on men's, but scientists and drug companies are trying to close the gap.

Categories: Literature

Africa: Women's invisible power

Nature - Wed, 10/04/2017 - 00:00

Africa: Women's invisible power

Nature. doi:10.1038/550S4a

Author: Linda Nordling

Understanding the nuances of women's various roles in African societies can make or break health research.

Categories: Literature

Genetics: Sex and the single cell

Nature - Wed, 10/04/2017 - 00:00

Genetics: Sex and the single cell

Nature. doi:10.1038/550S6a

Author: Claire Ainsworth

Sex chromosomes in every cell of the body exert widespread and sometimes unexpected effects.

Categories: Literature

A heartfelt plea

Nature - Wed, 10/04/2017 - 00:00

A heartfelt plea

Nature. doi:10.1038/550S9a

Author: Nanette Wenger

Heart disease is a different for women. Researchers must investigate, educate, advocate and legislate to decrease the risks, says Nanette Wenger.

Categories: Literature

Puberty: Early starters

Nature - Wed, 10/04/2017 - 00:00

Puberty: Early starters

Nature. doi:10.1038/550S10a

Author: Jessa Gamble

Girls are entering puberty at ever younger ages. What are the causes, and should we be worried?

Categories: Literature

Microbiome: Detecting diversity

Nature - Wed, 10/04/2017 - 00:00

Microbiome: Detecting diversity

Nature. doi:10.1038/550S12a

Author: Courtney Humphries

Surveys of the microbes that live in the vagina have revealed unexpected variability. More research might reveal links between these microbes, infection and birth complications.

Categories: Literature

Osteoporosis: Staying strong

Nature - Wed, 10/04/2017 - 00:00

Osteoporosis: Staying strong

Nature. doi:10.1038/550S15a

Author: Carolyn Brown

An improved understanding of bone loss can help women reduce their risk of fractures as they age.

Categories: Literature

Clinical research: Inequality in medicine

Nature - Wed, 10/04/2017 - 00:00

Clinical research: Inequality in medicine

Nature. doi:10.1038/550S18a

Author: Anna Nowogrodzki

Regulators have been calling for equal representation of men and women in health research for nearly 25 years. So why are women still underrepresented?

Categories: Literature

The United States is failing its mothers

Nature - Wed, 10/04/2017 - 00:00

The United States is failing its mothers

Nature. doi:10.1038/550S20a

Author: Lauren Gravitz

There is only one industrialized country where the rate of maternal deaths has risen over the past 30 years. US researchers are trying to find out what went wrong.

Categories: Literature

Medical imaging: Material change for X-ray detectors

Nature - Wed, 10/04/2017 - 00:00

Medical imaging: Material change for X-ray detectors

Nature 550, 7674 (2017). doi:10.1038/550047a

Authors: John A. Rowlands

The X-ray sensitivity of radiology instruments is limited by the materials used in their detectors. A material from the perovskite family of semiconductors could allow lower doses of X-rays to be used for medical imaging. See Letter p.87

Categories: Literature

Engineering: Computational design hits record resolution

Nature - Wed, 10/04/2017 - 00:00

Engineering: Computational design hits record resolution

Nature 550, 7674 (2017). doi:10.1038/550050a

Authors: Matthijs Langelaar

A supercomputer-powered design technique enables the discovery of efficient mechanical structures that have an unprecedented level of detail. The findings provide insights into both physical and biological structures. See Letter p.84

Categories: Literature

50 & 100 Years Ago

Nature - Wed, 10/04/2017 - 00:00

50 & 100 Years Ago

Nature 550, 7674 (2017). doi:10.1038/550051a

50 Years AgoThe British preoccupation with the need to persuade young people into science and engineering, but particularly the latter, was continued last week by the Research and Development Society ... Adults, at least, are prepared to take the subject seriously ... the British

Categories: Literature

Expanding and reprogramming the genetic code

Nature - Wed, 10/04/2017 - 00:00

Expanding and reprogramming the genetic code

Nature 550, 7674 (2017). doi:10.1038/nature24031

Authors: Jason W. Chin

Nature uses a limited, conservative set of amino acids to synthesize proteins. The ability to genetically encode an expanded set of building blocks with new chemical and physical properties is transforming the study, manipulation and evolution of proteins, and is enabling diverse applications, including approaches

Categories: Literature

A hybrid type Ia supernova with an early flash triggered by helium-shell detonation

Nature - Wed, 10/04/2017 - 00:00

A hybrid type Ia supernova with an early flash triggered by helium-shell detonation

Nature 550, 7674 (2017). doi:10.1038/nature23908

Authors: Ji-an Jiang, Mamoru Doi, Keiichi Maeda, Toshikazu Shigeyama, Ken’ichi Nomoto, Naoki Yasuda, Saurabh W. Jha, Masaomi Tanaka, Tomoki Morokuma, Nozomu Tominaga, Željko Ivezić, Pilar Ruiz-Lapuente, Maximilian D. Stritzinger, Paolo A. Mazzali, Christopher Ashall, Jeremy Mould, Dietrich Baade, Nao Suzuki, Andrew J. Connolly, Ferdinando Patat, Lifan Wang, Peter Yoachim, David Jones, Hisanori Furusawa & Satoshi Miyazaki

Type Ia supernovae arise from the thermonuclear explosion of white-dwarf stars that have cores of carbon and oxygen. The uniformity of their light curves makes these supernovae powerful cosmological distance indicators, but there have long been debates about exactly how their explosion is triggered and what kind of companion stars are involved. For example, the recent detection of the early ultraviolet pulse of a peculiar, subluminous type Ia supernova has been claimed as evidence for an interaction between a red-giant or a main-sequence companion and ejecta from a white-dwarf explosion. Here we report observations of a prominent but red optical flash that appears about half a day after the explosion of a type Ia supernova. This supernova shows hybrid features of different supernova subclasses, namely a light curve that is typical of normal-brightness supernovae, but with strong titanium absorption, which is commonly seen in the spectra of subluminous ones. We argue that this early flash does not occur through previously suggested mechanisms such as the companion–ejecta interaction. Instead, our simulations show that it could occur through detonation of a thin helium shell either on a near-Chandrasekhar-mass white dwarf, or on a sub-Chandrasekhar-mass white dwarf merging with a less-massive white dwarf. Our finding provides evidence that one branch of previously proposed explosion models—the helium-ignition branch—does exist in nature, and that such a model may account for the explosions of white dwarfs in a mass range wider than previously supposed.

Categories: Literature

Giga-voxel computational morphogenesis for structural design

Nature - Wed, 10/04/2017 - 00:00

Giga-voxel computational morphogenesis for structural design

Nature 550, 7674 (2017). doi:10.1038/nature23911

Authors: Niels Aage, Erik Andreassen, Boyan S. Lazarov & Ole Sigmund

In the design of industrial products ranging from hearing aids to automobiles and aeroplanes, material is distributed so as to maximize the performance and minimize the cost. Historically, human intuition and insight have driven the evolution of mechanical design, recently assisted by computer-aided design approaches. The computer-aided approach known as topology optimization enables unrestricted design freedom and shows great promise with regard to weight savings, but its applicability has so far been limited to the design of single components or simple structures, owing to the resolution limits of current optimization methods. Here we report a computational morphogenesis tool, implemented on a supercomputer, that produces designs with giga-voxel resolution—more than two orders of magnitude higher than previously reported. Such resolution provides insights into the optimal distribution of material within a structure that were hitherto unachievable owing to the challenges of scaling up existing modelling and optimization frameworks. As an example, we apply the tool to the design of the internal structure of a full-scale aeroplane wing. The optimized full-wing design has unprecedented structural detail at length scales ranging from tens of metres to millimetres and, intriguingly, shows remarkable similarity to naturally occurring bone structures in, for example, bird beaks. We estimate that our optimized design corresponds to a reduction in mass of 2–5 per cent compared to currently used aeroplane wing designs, which translates into a reduction in fuel consumption of about 40–200 tonnes per year per aeroplane. Our morphogenesis process is generally applicable, not only to mechanical design, but also to flow systems, antennas, nano-optics and micro-systems.

Categories: Literature

Printable organometallic perovskite enables large-area, low-dose X-ray imaging

Nature - Wed, 10/04/2017 - 00:00

Printable organometallic perovskite enables large-area, low-dose X-ray imaging

Nature 550, 7674 (2017). doi:10.1038/nature24032

Authors: Yong Churl Kim, Kwang Hee Kim, Dae-Yong Son, Dong-Nyuk Jeong, Ja-Young Seo, Yeong Suk Choi, In Taek Han, Sang Yoon Lee & Nam-Gyu Park

Medical X-ray imaging procedures require digital flat detectors operating at low doses to reduce radiation health risks. Solution-processed organic–inorganic hybrid perovskites have characteristics that make them good candidates for the photoconductive layer of such sensitive detectors. However, such detectors have not yet been built on thin-film transistor arrays because it has been difficult to prepare thick perovskite films (more than a few hundred micrometres) over large areas (a detector is typically 50 centimetres by 50 centimetres). We report here an all-solution-based (in contrast to conventional vacuum processing) synthetic route to producing printable polycrystalline perovskites with sharply faceted large grains having morphologies and optoelectronic properties comparable to those of single crystals. High sensitivities of up to 11 microcoulombs per air KERMA of milligray per square centimetre (μC mGyair−1 cm−2) are achieved under irradiation with a 100-kilovolt bremsstrahlung source, which are at least one order of magnitude higher than the sensitivities achieved with currently used amorphous selenium or thallium-doped cesium iodide detectors. We demonstrate X-ray imaging in a conventional thin-film transistor substrate by embedding an 830-micrometre-thick perovskite film and an additional two interlayers of polymer/perovskite composites to provide conformal interfaces between perovskite films and electrodes that control dark currents and temporal charge carrier transportation. Such an all-solution-based perovskite detector could enable low-dose X-ray imaging, and could also be used in photoconductive devices for radiation imaging, sensing and energy harvesting.

Categories: Literature

Delta progradation in Greenland driven by increasing glacial mass loss

Nature - Wed, 10/04/2017 - 00:00

Delta progradation in Greenland driven by increasing glacial mass loss

Nature 550, 7674 (2017). doi:10.1038/nature23873

Authors: Mette Bendixen, Lars Lønsmann Iversen, Anders Anker Bjørk, Bo Elberling, Andreas Westergaard-Nielsen, Irina Overeem, Katy R. Barnhart, Shfaqat Abbas Khan, Jason E. Box, Jakob Abermann, Kirsty Langley & Aart Kroon

Climate changes are pronounced in Arctic regions and increase the vulnerability of the Arctic coastal zone. For example, increases in melting of the Greenland Ice Sheet and reductions in sea ice and permafrost distribution are likely to alter coastal morphodynamics. The deltas of Greenland are largely unaffected by human activity, but increased freshwater runoff and sediment fluxes may increase the size of the deltas, whereas increased wave activity in ice-free periods could reduce their size, with the net impact being unclear until now. Here we show that southwestern Greenland deltas were largely stable from the 1940s to 1980s, but prograded (that is, sediment deposition extended the delta into the sea) in a warming Arctic from the 1980s to 2010s. Our results are based on the areal changes of 121 deltas since the 1940s, assessed using newly discovered aerial photographs and remotely sensed imagery. We find that delta progradation was driven by high freshwater runoff from the Greenland Ice Sheet coinciding with periods of open water. Progradation was controlled by the local initial environmental conditions (that is, accumulated air temperatures above 0 °C per year, freshwater runoff and sea ice in the 1980s) rather than by local changes in these conditions from the 1980s to 2010s at each delta. This is in contrast to a dominantly eroding trend of Arctic sedimentary coasts along the coastal plains of Alaska, Siberia and western Canada, and to the spatially variable patterns of erosion and accretion along the large deltas of the main rivers in the Arctic. Our results improve the understanding of Arctic coastal evolution in a changing climate, and reveal the impacts on coastal areas of increasing ice mass loss and the associated freshwater runoff and lengthening of open-water periods.

Categories: Literature

Giant pandas, gender lawsuit and more disaster havoc

Nature - Tue, 10/03/2017 - 22:00

Giant pandas, gender lawsuit and more disaster havoc

Nature 549, 7673 (2017). http://www.nature.com/doifinder/10.1038/549436a

The week in science: 22–28 September 2017.

Categories: Literature

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