bluuebunny/crossref_metadata_2025 huggingface dataset:
An S-band Receiver and Backend System for MeerKAT
Authors: Barr Ewan D.
Published: June 2018

The MPIfR is working together with SKA-SA and the Universities of Manchester and Oxford to deploy three instruments on MeerKAT: An S-band receiver system, a dedicated beamforming cluster and a flexible pulsar search cluster. Together these instruments will provide MeerKAT with powerful tools for supporting a wide range of scientific applications and in particular will enable large-scale pulsar and fast transient surveys to be performed. In these proceedings we describe the design, implementation and deployment timeline for these instruments.
MSP Binaries as Astrophysical Laboratories
Authors: Wadiasingh Zorawar , Harding Alice K. , Venter Christo , Böttcher Markus , Baring Matthew G.
Published: June 2018

Follow-up of unidentified Fermi sources has expanded the number of known galactic-field “black widow” and “redback” millisecond pulsar binaries from four to nearly 30. Several systems observed by Chandra, XMM-Newton, Suzaku, and NuSTAR exhibit double-peaked X-ray orbital modulation. This is attributed to synchrotron emission from electrons accelerated in an intrabinary shock and Doppler boosting by mildly relativistic bulk flow. We briefly discuss the rich complexity of these systems, their astrophysical utility, and open questions.
Mode changing in the Black Widow Pulsar
Authors: Mahajan Nikhil , van Kerkwijk Marten
Published: June 2018

Mode changing is a phenomenon where a pulsar’s emission abruptly changes between two or more quasi-stable modes. We have discovered mode changing in the Black Widow Pulsar (PSR B1957+20), a first detection of mode changing in a millisecond pulsar. On average, a mode change occurs every 1.7 seconds. Multiple components across the pulse profile participate in the mode changing, indicating that this is likely caused by a global change in the pulsar’s magnetosphere.
Search for pulsars and transients with the GMRT
Authors: Bhattacharyya Bhaswati
Published: June 2018

This paper details on the discovery of 21 pulsars using the Giant Metrewave Radio Telescope (GMRT) from targeted (Fermi directed search) and blind surveys (GMRT High Resolution Southern Sky - GHRSS) and results from the follow up studies. We discovered seven millisecond pulsars (MSPs) in the Fermi directed searches, which are the first Galactic MSPs discovered with the GMRT. We have discovered 13 pulsars (including a MSP and two mildly recycled pulsars) with the GHRSS survey, which is an off-Galactic-plane survey at 322 MHz with complementary target sky (declination range −40 deg to −54 deg) to other ongoing low-frequency surveys by GBT and LOFAR. The simultaneous time-domain and imaging study for localising pulsars and transients and efficient candidate investigation with machine learning are some of the features of the GHRSS survey, which are also finding application in the SKA design methodology.
MeerTRAP: A pulsar and fast transients survey with MeerKAT
Authors: Sanidas S. , Caleb M. , Driessen L. , Morello V. , Rajwade K. , Stappers B. W.
Published: June 2018

We present a brief overview of MeerTRAP, a real-time, fully commensal survey for pulsars and fast transients with the MeerKAT radio telescope in South Africa. MeerTRAP will combine the excellent sensitivity of MeerKAT with an unprecedented amount of on-sky time in order to significantly extend the parameter space covered by similar, previous or ongoing, surveys with other radio telescopes. Here, we will give a brief overview of the project.
Referencing the Polarization Orientation to the Emission-Region Magnetic Field
Authors: Rankin Joanna M.
Published: June 2018

Using the proper-motion as a proxy for a pulsar’s rotation-axis orientation, the emission polarization can be related to the magnetic field direction in the emission region, providing a much more physical foundation for understanding orthogonal mode radiation.
X-rays from the mode-switching PSR B0943+10
Authors: Mereghetti S. , Kuiper L. , Tiengo A. , Hessels J. , Hermsen W. , Stovall K. , Possenti A. , Rankin J. , Esposito P. , Turolla R. , Mitra D. , Wright G. , Stappers B. , Horneffer A. , Oslowski S. , Serylak M. , Griessmeier J.-M. , Rigoselli M.
Published: June 2018

New simultaneous X-ray and radio observations of the archetypal mode-switching pulsar PSR B0943+10 have been carried out with XMM-Newton and the LOFAR, LWA and Arecibo radio telescopes in November 2014. They allowed us to better constrain the X-ray spectral and variability properties of this pulsar and to detect, for the first time, the X-ray pulsations also during the X-ray-fainter mode. The combined timing and spectral analysis indicates that unpulsed non-thermal emission, likely of magnetospheric origin, and pulsed thermal emission from a small polar cap are present during both radio modes and vary in a correlated way.
What will eROSITA reveal among X-ray faint isolated neutron stars?
Authors: Pires Adriana M.
Published: June 2018

Since the discovery of the first radio pulsar fifty years ago, the population of neutron stars in our Galaxy has grown to over 2,600. A handful of these sources, exclusively seen in X-rays, show properties that are not observed in normal pulsars. Despite their scarcity, they are key to understanding aspects of the neutron star phenomenology and evolution. The forthcoming all-sky survey of eROSITA will unveil the X-ray faint end of the neutron star population at unprecedented sensitivity; therefore, it has the unique potential to constrain evolutionary models and advance our understanding of the sources that are especially silent in the radio and γ-ray regimes. In this contribution I discuss the expected role of eROSITA, and the challenges it will face, at probing the galactic neutron star population.
Low frequency pulsar observations with the international LOFAR station FR606
Authors: Bondonneau Louis , Grießmeier Jean-Mathias , Theureau Gilles , Serylak Maciej
Published: June 2018

The pulsar’s signal passes through the interstellar medium (ISM) which leads to both chromatic dispersive delays and multipath pulse broadening. These effects have a strong frequency dependence (f−2 and f−4 respectively). Pulse profiles of pulsars are also frequency-dependent leading to some degeneracy with the ISM imprint. Furthermore, many pulsars show a turnover of their spectrum around ~100 MHz. For all these reasons, the frequency band below 100 MHz contains a lot of information about both the pulsar emission and the ISM. Our study is based on a LOw Frequency ARray (LOFAR) monitoring campaign using the international station FR606. Firstly, we demonstrate the importance of a monitoring campaign. Secondly, we calculate median spectra and locate the turnover frequency for 3 pulsars (B0809+74, B1133+16, B1508+55).
Early results of a Phased Array Feed system at Effelsberg
Authors: Deng Xinping , Chippendale Aaron , Barr Ewan , Malenta Mateusz , Wucknitz Olaf , Hilmarsson Guðjón Henning , Houben Leon , George Daniel , Spitler Laura , Karuppusamy Ramesh , Kramer Michael , Wieching Gundolf
Published: June 2018

The overview of a Phased Array Feed (PAF) system and the early results with it on the 100 m diameter telescope at Effelsberg are presented in the paper.
Conquering systematics in the timing of the pulsar triple system J0337+1715: Towards a unique and robust test of the strong equivalence principle
Authors: Gusinskaia N. V. , Archibald A. M. , Hessels J. W. T. , Lorimer D. R. , Ransom S. M. , Stairs I. H. , Lynch R. S.
Published: June 2018

PSR J0337+1715 is a millisecond radio pulsar in a hierarchical stellar triple system with two white dwarfs. This system is a unique and excellent laboratory in which to test the strong equivalence principle (SEP) of general relativity. An initial SEP-violation test was performed using direct 3-body numerical integration of the orbit in order to model the more than 25000 pulse times of arrival (TOAs) from three radio telescopes: Arecibo, Green Bank and Westerbork. In this work I present our efforts to quantify the effects of systematics in the TOAs and timing residuals, which limit the precision of an SEP test. In particular, we apply Fourier-based techniques to the timing residuals in order to isolate the effects of systematics that can masquerade as an SEP violation.
Broadband observations of pulsar profiles and frequency dependent DMs
Authors: Rammala Isabella , Karastergiou Aris , Foster Griffin
Published: June 2018

The aim of our project is to search for ways to best extract information on pulsar profiles and the interstellar medium (ISM), using the wide frequency bands that are typical of radio telescopes today. Pulsar profiles typically show a strong dependence on frequency. This depends both on the intrinsic radio emission mechanism, and the interaction of the radio waves with the ISM that lies between the pulsars and our detectors on Earth, due mostly to the effects of dispersion and scattering. In this work, we make use of radio pulsar beam models from the existing literature, to generate simulated pulse profiles, observed across various bands (centre frequencies and bandwidths), for each beam model. For all the chosen geometric parameters of the pulsar beam, observed in any frequency band, the simulated profiles manifest a relative shift in phase in their observed components, as a result of the intrinsic profile evolution. This relative shift in phase could be interpreted as an additional component to the ISM induced dispersion measure (DM). This additional DM component due to profile evolution is frequency dependent. We discuss the systematics introduced to pulsar data due to this effect.
The Neutron Star Zoo
Authors: Kaspi Victoria M.
Published: June 2018

Since their discovery 50 years ago, neutron stars have continually astonished. From the first-discovered radio pulsars to the powerful “magnetars” that emit sudden bursts of X-rays and γ-rays, from the so-called Isolated Neutron Stars to Central Compact Objects, observational manifestations of neutron stars are surprisingly varied, with most properties totally unpredicted. The challenge is to cement an overarching physical theory of neutron stars and their birth properties that can explain this great diversity. Here I briefly survey the disparate neutron star classes, describe their properties, highlight recent results, and describe efforts at “grand unification” of this wealth of observational phenomena.
Pulsar Emission Physics: The First Fifty Years
Authors: Harding Alice K.
Published: June 2018

Over the last fifty years since the discovery of pulsars, our understanding of where and how pulsars emit the radiation we observe has undergone significant revision. The location and mechanisms of high-energy radiation are intimately tied to the sites of particle acceleration. The evolution of emission models has paralleled the development of increasingly more sensitive telescopes, especially at high energies. I will review the history of pulsar emission modeling, from the early days of gaps at the polar caps, to outer gaps and slot gaps in the outer magnetosphere, to the present era of global magnetosphere simulations that locate most acceleration and high-energy emission in the current sheets.
Policy Targeting to Reduce Economic Damages From Land Subsidence
Authors: Wade Christopher M. , Cobourn Kelly M. , Amacher Gregory S. , Hester Erich T.
Published: June 2018

Groundwater pumping contributes significantly to land subsidence, which generates economic costs as changes in the frequency of flooding affect property values. We evaluate these costs by estimating the marginal damages from pumping, which define the corrective policy incentive to address land subsidence externalities. In an application to the southern Chesapeake Bay region of Virginia, we find that land subsidence due to groundwater pumping is greatest in inland rural areas, but that the damages from pumping are greatest in coastal urban areas. Our results suggest that cost‐minimizing groundwater policy is spatially heterogeneous and targets the damages from land subsidence due to pumping in different locations, not simply physical land subsidence itself. These results are driven by differences in the spatial patterns of aquifer characteristics, which determine subsidence, and housing density, which determines the damages from subsidence.
Effects of Climate Variability on Snowmelt and Implications for Organic Matter in a High‐Elevation Lake
Authors: Sadro Steven , Sickman James O. , Melack John M. , Skeen Kevin
Published: June 2018

Few coupled lake‐watershed studies examine long‐term effects of climate on the ecosystem function of lakes in a hydrological context. We use 32 years of hydrological and biogeochemical data from a high‐elevation site in the Sierra Nevada of California to characterize variation in snowmelt in relation to climate variability and explore the impact on factors affecting phytoplankton biomass. The magnitude of accumulated winter snow, quantified through basinwide estimates of snow water equivalent (SWE), was the most important climate factor controlling variation in the timing and rate of spring snowmelt. Variations in SWE and snowmelt led to significant differences in lake flushing rate, water temperature, and nitrate concentrations across years. On average in dry years, snowmelt started 25 days earlier and proceeded 7 mm/day slower, and the lake began the ice‐free season with nitrate concentrations ~2 μM higher and water temperatures 9°C warmer than in wet years. Flushing rates in wet years were 2.5 times larger than those in dry years. Consequently, particulate organic matter concentrations, a proxy for phytoplankton biomass, were 5–6 μM higher in dry years. There was a temporal trend of increase in particulate organic matter across dry years that corresponded to lake warming independent of variation in SWE. These results suggest that phytoplankton biomass is increasing as a result of both interannual variability in precipitation and long‐term warming trends. Our study underscores the need to account for local‐scale catchment variability that may affect the accumulation of winter snowpack when predicting climate responses in lakes.
Mixing Efficiency in the Presence of Stratification: When Is It Constant?
Authors: Monismith Stephen G. , Koseff Jeffrey R. , White Brian L.
Published: June 2018

The efficiency of the conversion of mechanical to potential energy, often expressed as the flux Richardson number, Rif, is an important determinant of vertical mixing in the ocean. To examine the dependence of Rif on the buoyancy Reynolds number, ReB, we analyze three sets of data: microstructure profiler data for which mixing is inferred from rates of dissipation of turbulent kinetic energy (ε) and temperature variance (χ) measured in the open ocean, time series of spectrally fit values of ε and covariance‐derived buoyancy fluxes measured in nearshore internal waves, and time series of spectrally fit values of ε and χ measured in an energetic estuarine flow. While profiler data are well represented by Rif ≈ 0.2 for 1 < ReB < 1,000, the covariance data have much larger values of ReB and, consistent with direct numerical simulation results, show that Rif ~ ReB−0.5. The estuarine data have values of ReB that fall between those of the other two data sets but also shows Rif ≈ 0.2 for ReB < 5000. Overall, these data suggest that Rif is in general not constant and may be substantially less than 0.2 when ReB is large, although the value at which the transition from constant to ReB‐dependent mixing may depend on additional parameters that are yet to be determined. Nonetheless, for much of the ocean, ReB < 100 and so Rif is constant there.
Small Earthquakes Matter in Injection‐Induced Seismicity
Authors: Brown Megan R. M. , Ge Shemin
Published: June 2018

A simplistic triggering mechanism, pore pressure increase from injection, has been the focus of injection‐induced seismicity studies for decades. Research into other possible mechanisms, like poroelastic stress changes, is ongoing, but there has been relatively little focus on earthquake interaction. While studies have looked at how moderate‐magnitude events (M ≥ 3.0) may trigger larger magnitude‐induced seismicity, research into the cumulative effect of the hundreds to thousands of small‐magnitude (M ≤ 3.0) events is lacking. Here we use generic models to compare the possible stress changes from pore pressure increase and from earthquake interactions of small‐magnitude events. We find that the area of increased pore pressure is much larger than that of positive Coulomb static stress transfer; however, maximum Coulomb static stress change is larger than maximum pore pressure increase. We argue that, yes, small earthquakes do matter, and their interaction may be an important triggering mechanism to consider.
Rain on Generative Seas
Authors: Cavaleri Luigi , Bertotti Luciana
Published: June 2018

Following evidence derived in the field and from previous numerical experiments, we carry out wave modeling tests where the white‐capping and wind input source functions are modified to be functions of also the rain rate and the wind speed. We show the high sensitivity of the results to these parameterizations and how related physically sound, but purely intuitive, choices can reproduce almost perfectly the original results also in extreme conditions. We discuss the related physical and numerical implications.
Increases in Land Surface Temperature in Response to Fire in Siberian Boreal Forests and Their Attribution to Biophysical Processes
Authors: Liu Zhihua , Ballantyne Ashley P. , Cooper L. Annie
Published: June 2018

Wildfire is the most prevalent natural disturbance in boreal forests and impacts climate through biogeochemical (e.g., greenhouse gas emission from biomass burning) and biophysical (e.g., albedo [α], evapotranspiration [ET], and roughness) processes. We used satellite observations to investigate the immediate (i.e., 1 year after fire) biophysical effects of fire in Siberian boreal forests. We found that boreal forest fires have a net annual warming effect (0.0728 to 0.325 K) due to strong summer warming and weak winter cooling. Fires also increased the diurnal temperature range and seasonal amplitude. These effects are strongest in summer and significantly higher in evergreen than in deciduous coniferous forests. Decreases in ET contributed to warming effects in summer, and increases in α contributed to cooling in winter. Our results suggest that the increase in observed land surface temperature immediately following fires in boreal ecosystems is most likely due to reduced ET leading to a strong positive feedback on the surface radiative budget.
Deep Sea Currents Driven by Breaking Internal Tides on the Continental Slope
Authors: Xie Xiaohui , Liu Qian , Zhao Zhongxiang , Shang Xiaodong , Cai Shuqun , Wang Dongxiao , Chen Dake
Published: June 2018

Mooring data collected on the continental slope of the South China Sea show that along‐slope deep sea bottom currents are generated when large spring internal tides (internal waves with tidal frequency) are observed, with the maximum velocity amplitude exceeding 0.15 m/s. The observations are consistent with predictions that near‐bottom breaking of internal waves can result in generation of along‐slope flows when these waves obliquely approach the slope. A linear internal tide model in one horizontal dimension with realistic topography and stratification is used to show that the breaking of internal tides is likely due to near‐critical reflection on the slope. Combining the mooring observations and the model simulation, an along‐slope near‐bottom transport of ~0.5 Sv is estimated. Along‐slope bottom flows caused by breaking internal waves potentially provide a significant way to deform continental slopes and affect deep water exchange between the marginal sea and open ocean.
Investigation of Coatings for Langmuir Probes in an Oxygen‐Rich Space Environment
Authors: Samaniego Joseph I. , Wang Xu , Andersson Laila , Malaspina David , Ergun Robert E. , Horányi Mihály
Published: June 2018

Use of Langmuir probes in the atmospheres of planets is complicated by oxidation of the probe surface when high‐density oxygen atoms/molecules and/or ions are present. Oxidation of most materials creates an electrically resistive layer on the probe surface that reduces the current collected at a given bias voltage, changing the probe's current‐voltage (I‐V) curves and consequently the measured plasma parameters. TiN (Titanium Nitride), DAG (a graphite coating), or Gold are currently used Langmuir probe coatings, yet they all have issues when exposed to oxygen‐rich environments. Iridium and Rhenium are selected as new coating candidates because of the high conductivity of their oxidized forms and high hardness. Here we present the oxidation effect on the measurements of probes made of current coating materials (DAG, Gold, and TiN) and new coating materials (Iridium and Rhenium) against controls (Copper and Nickel) in the laboratory. The oxidation process is performed by bombarding oxygen ions on the probe surface with energies of 1.5–10 eV. The probe's I‐V curves taken in an argon plasma are compared before and after oxidation. Our results show that the TiN, Gold, and DAG probes show significant to small changes in their I‐V curves, while Iridium outperforms all the other testing materials with almost unchanged I‐V curves after the oxidation process. Additionally, this new coating can be applied for other plasma instruments in which surface oxidation may pose an issue. However, for the application of Iridium to electric field probes, future work must be carried out to determine photoemission characteristics.
Metabolic patterns in insulin-resistant male hypogonadism
Authors: Gevi Federica , Fanelli Giuseppina , Zolla Lello
Published: June 2018

Male hypogonadism associated with insulin resistance (IR) very often leads to metabolic syndrome, at variance with hypogonadism in its first stadium of insulin sensitivity (IS). A plasma metabolomic investigation of these patients can provide useful information in comparison with the values of IS patients. To this aim plasma from insulin-resistant males with hypogonadism were analysed by using ultra high-performance liquid chromatography (UHPLC) and high-resolution mass spectrometry (HRMS). Thus, metabolites were compared to the controls through multivariate statistical analysis and grouped by metabolic pathways. Metabolite database searches and pathway analyses identified imbalances in 18–20 metabolic pathways. Glucose metabolism (e.g., glycolysis and the Krebs cycle) is fuelled by amino acids degradation, in particular of branched amino acids, in individuals with lean body mass. Gluconeogenesis is strongly activated. Some crucial pathways such as glycerol are skewed. Mitochondrial electron transport is affected with a reduction in ATP production. Beta-oxidation of short and medium chain fatty acids did not represent an energy source in hypogonadism, at variance with long and branched fatty acids, justifying the increase in fat mass. Carnosine and β-alanine are strongly reduced resulting in increased fatigue and mental confusion. A comparison of IR with IS male hypogonadism will contribute to a better understanding of how these two hormones work in synergy or antagonise each other in humans. It could also help to select patients who will respond to hormone treatment, and provide accurate biomarkers to measure the response to treatment eventually leading to better strategies in preventing systemic complications in patients not fit for hormone replacement therapy.
CREB controls cortical circuit plasticity and functional recovery after stroke
Authors: Caracciolo L. , Marosi M. , Mazzitelli J. , Latifi S. , Sano Y. , Galvan L. , Kawaguchi R. , Holley S. , Levine M. S. , Coppola G. , Portera-Cailliau C. , Silva A. J. , Carmichael S. T.
Published: June 2018

Treatments that stimulate neuronal excitability enhance motor performance after stroke. cAMP-response-element binding protein (CREB) is a transcription factor that plays a key role in neuronal excitability. Increasing the levels of CREB with a viral vector in a small pool of motor neurons enhances motor recovery after stroke, while blocking CREB signaling prevents stroke recovery. Silencing CREB-transfected neurons in the peri-infarct region with the hM4Di-DREADD blocks motor recovery. Reversing this inhibition allows recovery to continue, demonstrating that by manipulating the activity of CREB-transfected neurons it is possible to turn off and on stroke recovery. CREB transfection enhances remapping of injured somatosensory and motor circuits, and induces the formation of new connections within these circuits. CREB is a central molecular node in the circuit responses after stroke that lead to recovery from motor deficits.
Analysis of 3800-year-old Yersinia pestis genomes suggests Bronze Age origin for bubonic plague
Authors: Spyrou Maria A. , Tukhbatova Rezeda I. , Wang Chuan-Chao , Valtueña Aida Andrades , Lankapalli Aditya K. , Kondrashin Vitaly V. , Tsybin Victor A. , Khokhlov Aleksandr , Kühnert Denise , Herbig Alexander , Bos Kirsten I. , Krause Johannes
Published: June 2018

The origin ofYersinia pestisand the early stages of its evolution are fundamental subjects of investigation given its high virulence and mortality that resulted from past pandemics. Although the earliest evidence ofY. pestisinfections in humans has been identified in Late Neolithic/Bronze Age Eurasia (LNBA 5000–3500y BP), these strains lack key genetic components required for flea adaptation, thus making their mode of transmission and disease presentation in humans unclear. Here, we reconstruct ancientY. pestisgenomes from individuals associated with the Late Bronze Age period (~3800 BP) in the Samara region of modern-day Russia. We show clear distinctions between our new strains and the LNBA lineage, and suggest that the full ability for flea-mediated transmission causing bubonic plague evolved more than 1000 years earlier than previously suggested. Finally, we propose that severalY. pestislineages were established during the Bronze Age, some of which persist to the present day.
Genetic inactivation of ANGPTL4 improves glucose homeostasis and is associated with reduced risk of diabetes
Authors: Gusarova Viktoria , O’Dushlaine Colm , Teslovich Tanya M. , Benotti Peter N. , Mirshahi Tooraj , Gottesman Omri , Van Hout Cristopher V. , Murray Michael F. , Mahajan Anubha , Nielsen Jonas B. , Fritsche Lars , Wulff Anders Berg , Gudbjartsson Daniel F. , Sjögren Marketa , Emdin Connor A. , Scott Robert A. , Lee Wen-Jane , Small Aeron , Kwee Lydia C. , Dwivedi Om Prakash , Prasad Rashmi B. , Bruse Shannon , Lopez Alexander E. , Penn John , Marcketta Anthony , Leader Joseph B. , Still Christopher D. , Kirchner H. Lester , Mirshahi Uyenlinh L. , Wardeh Amr H. , Hartle Cassandra M. , Habegger Lukas , Fetterolf Samantha N. , Tusie-Luna Teresa , Morris Andrew P. , Holm Hilma , Steinthorsdottir Valgerdur , Sulem Patrick , Thorsteinsdottir Unnur , Rotter Jerome I. , Chuang Lee-Ming , Damrauer Scott , Birtwell David , Brummett Chad M. , Khera Amit V. , Natarajan Pradeep , Orho-Melander Marju , Flannick Jason , Lotta Luca A. , Willer Cristen J. , Holmen Oddgeir L. , Ritchie Marylyn D. , Ledbetter David H. , Murphy Andrew J. , Borecki Ingrid B. , Reid Jeffrey G. , Overton John D. , Hansson Ola , Groop Leif , Shah Svati H. , Kraus William E. , Rader Daniel J. , Chen Yii-Der I. , Hveem Kristian , Wareham Nicholas J. , Kathiresan Sekar , Melander Olle , Stefansson Kari , Nordestgaard Børge G. , Tybjærg-Hansen Anne , Abecasis Goncalo R. , Altshuler David , Florez Jose C. , Boehnke Michael , McCarthy Mark I. , Yancopoulos George D. , Carey David J. , Shuldiner Alan R. , Baras Aris , Dewey Frederick E. , Gromada Jesper
Published: June 2018

Angiopoietin-like 4 (ANGPTL4) is an endogenous inhibitor of lipoprotein lipase that modulates lipid levels, coronary atherosclerosis risk, and nutrient partitioning. We hypothesize that loss of ANGPTL4 function might improve glucose homeostasis and decrease risk of type 2 diabetes (T2D). We investigate protein-altering variants in ANGPTL4 among 58,124 participants in the DiscovEHR human genetics study, with follow-up studies in 82,766 T2D cases and 498,761 controls. Carriers of p.E40K, a variant that abolishes ANGPTL4 ability to inhibit lipoprotein lipase, have lower odds of T2D (odds ratio 0.89, 95% confidence interval 0.85–0.92, p = 6.3 × 10−10), lower fasting glucose, and greater insulin sensitivity. Predicted loss-of-function variants are associated with lower odds of T2D among 32,015 cases and 84,006 controls (odds ratio 0.71, 95% confidence interval 0.49–0.99, p = 0.041). Functional studies in Angptl4-deficient mice confirm improved insulin sensitivity and glucose homeostasis. In conclusion, genetic inactivation of ANGPTL4 is associated with improved glucose homeostasis and reduced risk of T2D.
Solvent-controlled growth of inorganic perovskite films in dry environment for efficient and stable solar cells
Authors: Wang Pengyang , Zhang Xingwang , Zhou Yuqin , Jiang Qi , Ye Qiufeng , Chu Zema , Li Xingxing , Yang Xiaolei , Yin Zhigang , You Jingbi
Published: June 2018

Inorganic halide perovskites such as cesium lead halide are promising due to their excellent thermal stability. Cesium lead iodide (CsPbI3) has a bandgap of 1.73 eV and is very suitable for making efficient tandem solar cells, either with low-bandgap perovskite or silicon. However, the phase instability of CsPbI3 is hindering the further optimization of device performance. Here, we show that high quality and stable α-phase CsPbI3 film is obtained via solvent-controlled growth of the precursor film in a dry environment. A 15.7% power conversion efficiency of CsPbI3 solar cells is achieved, which is the highest efficiency reported for inorganic perovskite solar cells up to now. And more importantly, the devices can tolerate continuous light soaking for more than 500 h without efficiency drop.
Nickel-catalyzed reductive thiolation and selenylation of unactivated alkyl bromides
Authors: Fang Yi , Rogge Torben , Ackermann Lutz , Wang Shun-Yi , Ji Shun-Jun
Published: June 2018

Chalcogen-containing compounds have received considerable attention because of their manifold applications in agrochemicals, pharmaceuticals, and material science. While many classical methods have been developed for preparing organic sulfides, most of them exploited the transition-metal-catalyzed cross-couplings of aryl halides or pseudo halides with thiols or disulfides, with harsh reaction conditions usually being required. Herein, we present a user-friendly, nickel-catalyzed reductive thiolation of unactivated primary and secondary alkyl bromides with thiosulfonates as reliable thiolation reagents, which are easily prepared and bench-stable. Furthermore, a series of selenides is also prepared in a similar fashion with selenosulfonates as selenolation reagents. This catalytic method offers a facile synthesis of a wide range of unsymmetrical alkyl-aryl or alkyl-alkyl sulfides and selenides under mild conditions with an excellent tolerance of functional groups. Likewise, the use of sensitive and stoichiometric organometallic reagents can be avoided.
A multi-modal MRI study of the central response to inflammation in rheumatoid arthritis
Authors: Schrepf Andrew , Kaplan Chelsea M. , Ichesco Eric , Larkin Tony , Harte Steven E. , Harris Richard E. , Murray Alison D. , Waiter Gordon D. , Clauw Daniel J. , Basu Neil
Published: June 2018

It is unknown how chronic inflammation impacts the brain. Here, we examined whether higher levels of peripheral inflammation were associated with brain connectivity and structure in 54 rheumatoid arthritis patients using functional and structural MRI. We show that higher levels of inflammation are associated with more positive connections between the inferior parietal lobule (IPL), medial prefrontal cortex, and multiple brain networks, as well as reduced IPL grey matter, and that these patterns of connectivity predicted fatigue, pain and cognitive dysfunction. At a second scan 6 months later, some of the same patterns of connectivity were again associated with higher peripheral inflammation. A graph theoretical analysis of whole-brain functional connectivity revealed a pattern of connections spanning 49 regions, including the IPL and medial frontal cortex, that are associated with peripheral inflammation. These regions may play a critical role in transducing peripheral inflammatory signals to the central changes seen in rheumatoid arthritis.
Strong sesquiterpene emissions from Amazonian soils
Authors: Bourtsoukidis E. , Behrendt T. , Yañez-Serrano A. M. , Hellén H. , Diamantopoulos E. , Catão E. , Ashworth K. , Pozzer A. , Quesada C. A. , Martins D. L. , Sá M. , Araujo A. , Brito J. , Artaxo P. , Kesselmeier J. , Lelieveld J. , Williams J.
Published: June 2018

The Amazon rainforest is the world’s largest source of reactive volatile isoprenoids to the atmosphere. It is generally assumed that these emissions are products of photosynthetically driven secondary metabolism and released from the rainforest canopy from where they influence the oxidative capacity of the atmosphere. However, recent measurements indicate that further sources of volatiles are present. Here we show that soil microorganisms are a strong, unaccounted source of highly reactive and previously unreported sesquiterpenes (C15H24; SQT). The emission rate and chemical speciation of soil SQTs were determined as a function of soil moisture, oxygen, and rRNA transcript abundance in the laboratory. Based on these results, a model was developed to predict soil–atmosphere SQT fluxes. It was found SQT emissions from a Terra Firme soil in the dry season were in comparable magnitude to current global model canopy emissions, establishing an important ecological connection between soil microbes and atmospherically relevant SQTs.
Scaling law for excitons in 2D perovskite quantum wells
Authors: Blancon J.-C. , Stier A. V. , Tsai H. , Nie W. , Stoumpos C. C. , Traoré B. , Pedesseau L. , Kepenekian M. , Katsutani F. , Noe G. T. , Kono J. , Tretiak S. , Crooker S. A. , Katan C. , Kanatzidis M. G. , Crochet J. J. , Even J. , Mohite A. D.
Published: June 2018

Ruddlesden–Popper halide perovskites are 2D solution-processed quantum wells with a general formula A2A’n-1M
n
X3n+1, where optoelectronic properties can be tuned by varying the perovskite layer thickness (n-value), and have recently emerged as efficient semiconductors with technologically relevant stability. However, fundamental questions concerning the nature of optical resonances (excitons or free carriers) and the exciton reduced mass, and their scaling with quantum well thickness, which are critical for designing efficient optoelectronic devices, remain unresolved. Here, using optical spectroscopy and 60-Tesla magneto-absorption supported by modeling, we unambiguously demonstrate that the optical resonances arise from tightly bound excitons with both exciton reduced masses and binding energies decreasing, respectively, from 0.221 m0 to 0.186 m0 and from 470 meV to 125 meV with increasing thickness from n equals 1 to 5. Based on this study we propose a general scaling law to determine the binding energy of excitons in perovskite quantum wells of any layer thickness.
Diverse populations of local interneurons integrate into the Drosophila adult olfactory circuit
Authors: Liou Nan-Fu , Lin Shih-Han , Chen Ying-Jun , Tsai Kuo-Ting , Yang Chi-Jen , Lin Tzi-Yang , Wu Ting-Han , Lin Hsin-Ju , Chen Yuh-Tarng , Gohl Daryl M. , Silies Marion , Chou Ya-Hui
Published: June 2018

Drosophila olfactory local interneurons (LNs) in the antennal lobe are highly diverse and variable. How and when distinct types of LNs emerge, differentiate, and integrate into the olfactory circuit is unknown. Through systematic developmental analyses, we found that LNs are recruited to the adult olfactory circuit in three groups. Group 1 LNs are residual larval LNs. Group 2 are adult-specific LNs that emerge before cognate sensory and projection neurons establish synaptic specificity, and Group 3 LNs emerge after synaptic specificity is established. Group 1 larval LNs are selectively reintegrated into the adult circuit through pruning and re-extension of processes to distinct regions of the antennal lobe, while others die during metamorphosis. Precise temporal control of this pruning and cell death shapes the global organization of the adult antennal lobe. Our findings provide a road map to understand how LNs develop and contribute to constructing the olfactory circuit.
Experimental realization of a Rydberg optical Feshbach resonance in a quantum many-body system
Authors: Thomas O. , Lippe C. , Eichert T. , Ott H.
Published: June 2018

Feshbach resonances are a powerful tool to tune the interaction in an ultracold atomic gas. The commonly used magnetic Feshbach resonances are specific for each species and are restricted with respect to their temporal and spatial modulation. Optical Feshbach resonances are an alternative which can overcome this limitation. Here, we show that ultra-long-range Rydberg molecules can be used to implement an optical Feshbach resonance. Tuning the on-site interaction of a degenerate Bose gas in a 3D optical lattice, we demonstrate a similar performance compared to recent realizations of optical Feshbach resonances using intercombination transitions. Our results open up a class of optical Feshbach resonances with a plenitude of available lines for many atomic species and the possibility to further increase the performance by carefully selecting the underlying Rydberg state.
Anomalous Hall magnetoresistance in a ferromagnet
Authors: Yang Yumeng , Luo Ziyan , Wu Haijun , Xu Yanjun , Li Run-Wei , Pennycook Stephen J. , Zhang Shufeng , Wu Yihong
Published: June 2018

The anomalous Hall effect, observed in conducting ferromagnets with broken time-reversal symmetry, offers the possibility to couple spin and orbital degrees of freedom of electrons in ferromagnets. In addition to charge, the anomalous Hall effect also leads to spin accumulation at the surfaces perpendicular to both the current and magnetization direction. Here, we experimentally demonstrate that the spin accumulation, subsequent spin backflow, and spin–charge conversion can give rise to a different type of spin current-related spin current related magnetoresistance, dubbed here as the anomalous Hall magnetoresistance, which has the same angular dependence as the recently discovered spin Hall magnetoresistance. The anomalous Hall magnetoresistance is observed in four types of samples: co-sputtered (Fe1−xMn
x
)0.6Pt0.4, Fe1−xMn
x
/Pt multilayer, Fe1−xMn
x
with x = 0.17–0.65 and Fe, and analyzed using the drift-diffusion model. Our results provide an alternative route to study charge–spin conversion in ferromagnets and to exploit it for potential spintronic applications.
Boosting hot electron flux and catalytic activity at metal–oxide interfaces of PtCo bimetallic nanoparticles
Authors: Lee Hyosun , Lim Juhyung , Lee Changhwan , Back Seoin , An Kwangjin , Shin Jae Won , Ryoo Ryong , Jung Yousung , Park Jeong Young
Published: June 2018

Despite numerous studies, the origin of the enhanced catalytic performance of bimetallic nanoparticles (NPs) remains elusive because of the ever-changing surface structures, compositions, and oxidation states of NPs under reaction conditions. An effective strategy for obtaining critical clues for the phenomenon is real-time quantitative detection of hot electrons induced by a chemical reaction on the catalysts. Here, we investigate hot electrons excited on PtCo bimetallic NPs during H2 oxidation by measuring the chemicurrent on a catalytic nanodiode while changing the Pt composition of the NPs. We reveal that the presence of a CoO/Pt interface enables efficient transport of electrons and higher catalytic activity for PtCo NPs. These results are consistent with theoretical calculations suggesting that lower activation energy and higher exothermicity are required for the reaction at the CoO/Pt interface.
Publisher Correction: Imaging the square of the correlated two-electron wave function of a hydrogen molecule
Authors: Waitz M. , Bello R. Y. , Metz D. , Lower J. , Trinter F. , Schober C. , Keiling M. , Lenz U. , Pitzer M. , Mertens K. , Martins M. , Viefhaus J. , Klumpp S. , Weber T. , Schmidt L. Ph. H. , Williams J. B. , Schöffler M. S. , Serov V. V. , Kheifets A. S. , Argenti L. , Palacios A. , Martín F. , Jahnke T. , Dörner R.
Published: June 2018

The original version of this Article contained an error in the fifth sentence of the first paragraph of the ‘Application on H2’ section of the Results, which incorrectly read ‘The role of electron correlation is quite apparent in this presentation: Fig. 1a is empty for the uncorrelated Hartree–Fock wave function, since projection of the latter wave function onto the 2pσu orbital is exactly zero, while this is not the case for the fully correlated wave function (Fig. 1d); also, Fig. 1b, c for the uncorrelated description are identical, while Fig. 1e, f for the correlated case are significantly different.’ The correct version replaces ‘Fig. 1e, f’ with ‘Fig. 2e and f’.
Author Correction: HIV-1 counteracts an innate restriction by amyloid precursor protein resulting in neurodegeneration
Authors: Chai Qingqing , Jovasevic Vladimir , Malikov Viacheslav , Sabo Yosef , Morham Scott , Walsh Derek , Naghavi Mojgan H.
Published: June 2018

The original version of this Article contained an error in the Methods section ‘Viruses and drugs’. The timing for drug treatment of CHME3 4 × 4 or 293T cells with γ-secretase inhibitor or BACE1 inhibitor was incorrectly given as ‘1 day prior to infection or transfection’ and should have stated ‘4 or 6 h post transfection or infection, respectively’. This error is now corrected in both the PDF and HTML versions of the Article.
Publisher Correction: 78,000-year-old record of Middle and Later Stone Age innovation in an East African tropical forest
Authors: Shipton Ceri , Roberts Patrick , Archer Will , Armitage Simon J. , Bita Caesar , Blinkhorn James , Courtney-Mustaphi Colin , Crowther Alison , Curtis Richard , Errico Francesco d’ , Douka Katerina , Faulkner Patrick , Groucutt Huw S. , Helm Richard , Herries Andy I. R. , Jembe Severinus , Kourampas Nikos , Lee-Thorp Julia , Marchant Rob , Mercader Julio , Marti Africa Pitarch , Prendergast Mary E. , Rowson Ben , Tengeza Amini , Tibesasa Ruth , White Tom S. , Petraglia Michael D. , Boivin Nicole
Published: June 2018

The originally published version of this Article contained an error in Fig. 3, whereby an additional unrelated graph was overlaid on top of the magnetic susceptibility plot. Furthermore, the Article title contained an error in the capitalisation of ‘Stone Age’. Both of these errors have now been corrected in both the PDF and HTML versions of the Article.
Intraoperative detection of circulating tumor cells in pulmonary venous blood during metastasectomy for colorectal lung metastases
Authors: Le Uyen-Thao , Bronsert Peter , Picardo Francesco , Riethdorf Sabine , Haager Benedikt , Rylski Bartosz , Czerny Martin , Beyersdorf Friedhelm , Wiesemann Sebastian , Pantel Klaus , Passlick Bernward , Kaifi Jussuf Thomas , Schmid Severin
Published: June 2018

Circulating tumor cells (CTC) have been studied extensively in various tumor types and are a well-established prognosticator in colorectal cancer (CRC). This is the first study to isolate CTC directly from the tumor outflow in secondary lung tumors. For this purpose in 24 patients with CRC who underwent pulmonary metastasectomy in curative intent blood was drawn intraoperatively from the pulmonary vein (tumor outflow). In 22 samples CTC-enumeration was performed using CellSieve-microfilters and immunohistochemical- and Giemsa-staining. Additionally 10 blood samples were analyzed using the CellSearch-System. We could isolate more CTC in pulmonary venous blood (total 41, range 0–15) than in samples taken from the periphery at the same time (total 6, range 0–5, p = 0.09). Tumor positive lymph nodes correlated with presence of CTC in pulmonary venous blood as in all cases CTC were present (p = 0.02). Our findings suggest a tumor cell release from pulmonary metastases in CRC and a correlation of CTC isolated from the tumor outflow with established negative prognostic markers in metastasized CRC. The presented data warrant further investigations regarding the significance of local tumor compartments when analyzing circulating markers and the possibility of tumor cell shedding from secondary lung tumors.
Expression of the Shrimp wap gene in Drosophila elicits defense responses and protease inhibitory activity
Authors: Li Dianxiang , Luan Yuanyuan , Wang Lei , Qi Mei , Wang Jinxing , Xu Jidong , Arefin Badrul , Li Meixia
Published: June 2018

The wap gene encodes a single whey acidic protein (WAP) domain-containing peptide from Chinese white shrimp (Fenneropenaeus chinensis), which shows broad-spectrum antimicrobial activities and proteinase inhibitory activities in vitro. To explore the medical applications of the WAP peptide, a wap gene transgenic Drosophila melanogaster was constructed. In wap-expressing flies, high expression levels of wap gene (>100 times) were achieved, in contrast to those of control flies, by qRT-PCR analysis. The wap gene expression was associated with increased resistance to microbial infection and decreased bacterial numbers in the flies. In addition, the WAP protein extract from wap-expressing flies, compared with control protein extract from control flies, showed improved antimicrobial activities against broad Gram-positive and Gram-negative bacteria, including the clinical drug resistant bacterium of methicillin-resistant S. aureus (MRSA), improved protease inhibitor activities against crude proteinases and commercial proteinases, including elastase, subtilis proteinase A, and proteinase K in vitro, and improved growth rate and microbial resistance, as well as wound-healing in loach and mouse models. These results suggest that wap-expressing flies could be used as a food additive in aquaculture to prevent infections and a potential antibacterial for fighting drug-resistant bacteria.
MicroRNA-410-5p exacerbates high-fat diet-induced cardiac remodeling in mice in an endocrine fashion
Authors: Zou Tong , Zhu Mei , Ma Yi-Cheng , Xiao Fei , Yu Xue , Xu Li , Ma Lan-Qing , Yang Jiefu , Dong Jian-Zeng
Published: June 2018

Metabolic disorders, such as obesity and type 2 diabetes, are associated with an increased risk of cardiomyopathy. To date, microRNA (miRNAs) functions in cardiac remodeling induced by obesity remain to be elucidated. We found that rats fed a high fat diet (HFD) manifested cardiac fibrosis and LV dysfunction. In the heart of rats fed HFD, the phosphorylation levels of Smad 2 and the expression of fibrotic genes, such as connective tissue growth factor, collagen-1α1 (Col1α1), Col3α1, and Col4α1, were up-regulated, which accompanied by an increase in Smad 7 protein levels, but not its mRNA levels. Using miRNA microarray analysis, we showed that the miRNA miR-410-5p inhibited the protein expression of Smad 7, thus increasing the phosphorylation levels of Smad 2. Overexpression of miR-410-5p promoted cardiac fibrosis in rats fed normal diet, whereas inhibition of miR-410-5p by way of miR-410-5p antimiR suppressed cardiac fibrosis in rats fed HFD. Finally, our data revealed that miR-410-5p from the kidney and adipose tissues was probably transferred to heart to induce cardiac fibrosis. Taken together, our study characterizes an endocrine mechanism in which adipose- or kidney-derived circulating miR-410-5p regulates metabolic disorders-mediated cardiac remodeling by activating the TGFβ/Smad signaling in heart.