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The scalp electroencephalogram (EEG) signals detect the extracellular electrical field generated by the columns underneath the electrodes closer to the cortical surface and represent near-synchronous summated potentials (excitatory postsynaptic potential (EPSP) and inhibitory postsynaptic potential (IPSP)) generated by these columns of the cerebral cortex.1–4
Consumption of sugar sweetened beverages (SSBs) in infants and young children are less explored in Asian populations. The Growing in Singapore Towards healthy Outcomes (GUSTO) cohort study examined associations between SSB intakes at ages 18 months and 5 years with adiposity measures at age 6 years. We studied Singaporean infants/children with SSB intake assessed by food frequency questionnaires (FFQ) at ages 18 months (n=555) and 5 years (n=767). The median (interquartile range) for SSB intakes is 28(5.5-98) ml at age 18 months and 111 (57-198) ml at age 5 years. Associations between SSB intakes (100 ml/day increments and tertile categories) and adiposity measures (BMI standard deviation scores (s.d. unit), sum of skinfolds (SSFs)) and overweight/obesity status were examined using multivariable linear and Poisson regression models, respectively. After adjusting for confounders and additionally for energy intake, SSB intakes at age 18 months were not significantly associated with later adiposity measures and overweight/obesity outcomes. In contrast, at age 5 years, SSB intakes when modelled as 100ml/day increments were associated with higher BMI by 0.09 (95% CI: 0.02, 0.16) s.d. unit, higher SSF thickness by 0.68 (0.06, 1.44) mm, and increased risk for overweight/obesity by 1.2 times (1.07, 1.23) at age 6 years. Trends were consistent with SSB intakes modelled as categorical tertiles. In summary, SSB intake in young childhood is associated with higher risks of adiposity and risk for overweight/obesity. Public health policies working to reduce SSB consumption need to focus on prevention programs targeted at young children.
Arbuscular mycorrhizal fungi (AMF) can increase plant nutrient uptake and chemical defense production, both of which can improve plants’ ability to resist insect herbivory. Cover crops—non-commercial species planted in between cash crops in a crop rotation—can naturally alter both soil nutrients and AMF. We tested whether different cover crop species alter AMF colonization, plant nutrient status and plant–insect interactions in a subsequent maize crop. Cover crop species were either non-mycorrhizal, non-leguminous (canola, forage radish), mycorrhizal non-leguminous (cereal rye, oats), mycorrhizal leguminous (clover, pea) or absent (fallow). We measured the cascading consequences of cover crop treatment on maize root AMF colonization, maize growth and performance of an herbivorous insect (European corn borer) feeding on the maize. Maize AMF colonization was greater in plots previously planted with mycorrhizal (rye, oats) than non-mycorrhizal (canola, radish) cover crops or no cover crop (fallow). AMF colonization was linked to increased plant phosphorous and nitrogen, and maize growth increased with low plant N:P. Induced jasmonic acid pathway plant defenses increased with increasing maize growth and AMF colonization. European corn borer survivorship decreased with lower plant N:P, and insect development rate decreased with increased induced plant defenses. Our data describe a cascade in which cover crop species selection can increase or decrease mycorrhizal colonization of subsequent maize crop roots, which in turn impacts phosphorus uptake and may affect herbivory resistance in the maize. These results suggest that farmers could select cover crop species to manage nutrient uptake and pest resistance, in order to amend or limit fertilizer and pesticide use.
Visual vertigo is defined as a condition in which there is worsening or triggering of vestibular symptoms in certain visual environments. Previous studies have associated visual vertigo with an increased prevalence of underlying white matter lesions on brain imaging.
This study evaluated the magnetic resonance imaging scans of the brain from a cohort of patients with visual vertigo, and compared the outcomes to an age- and gender-matched group of healthy volunteers.
Results and conclusion
White matter lesions were observed in 17.9 per cent of the patient group and in 16.3 per cent of the control group. The prevalence of white matter lesions in the patient group was not too different to that expected based on age.
A new lonchidiid genus, Pristrisodus, from the Upper Triassic Tiki Formation of India is described based on multiple, well-preserved, isolated teeth. Comparative analysis resulted in synonymizing Parvodus tikiensis and Lissodus duffini, which are known from the same horizon and resulted in a new taxon, Pristrisodus tikiensis n. comb. These teeth are elongated with mesiodistal length greater than or equal to twice the labiolingual width and have a high principal cusp, lateral cusplets, a distinct ridge near the crown-root junction labially and higher up on the crown lingually, weak ornamentation, and linear depression along the crown-root junction. Five morphotypes based on overall shape, robustness and crown height are determined. The teeth show a gradual monognathic heterodonty. The anterolateral teeth (morphotypes I−II) have high, pyramidal principal cusp with two or three small but pointed cusplets, and triangular labial and lingual protuberance. The posterolateral teeth (morphotypes III−IV) have four incipient cusplets, relatively low principal cusp, bilobed/rounded, hanging labial and incipient lingual protuberances. Morphotype V comprises anterior teeth that are broad, triangular and robust, and have rounded/blunt principal cusp, one cusplet, and low, hanging labial peg. Multivariate analyses corroborate the qualitative assessment of the Indian hybodonts. Dental histology of Pristrisodus n. gen., shows that it is distinctly different from other lonchidiid genera. The assemblage of freshwater sharks, along with other vertebrate microfossils of the Tiki Formation, shows similarity with that of the lower Tecovas Formation of the Chinle Group, USA. The euryhaline nature resulted in the adaptation of the hybodonts to freshwater systems in India during the Carnian.
Implicit in the significant resources invested globally in SETI searches is the assumption that there is a small but finite probability that one such search will be successful in the next few years. The potential significance of such an event makes it essential to have contingency plans in place to deal with it. I describe the processes that are in place to deal with a SETI detection, including the SETI Post-Detection Committee and outline the challenges facing us.
We present techniques for obtaining large (∼100 L STP) samples of ancient air for analysis of 14C of methane (14CH4)and other trace constituents. Paleoatmospheric 14CH4 measurements should constrain the fossil fraction of past methane budgets, as well as provide a definitive test of methane clathrate involvement in large and rapid methane concentration ([CH4]) increases that accompanied rapid warming events during the last deglaciation. Air dating to the Younger Dryas–Preboreal and Oldest Dryas–Bølling abrupt climatic transitions was obtained by melt extraction from old glacial ice outcropping at an ablation margin in West Greenland. The outcropping ice and occluded air were dated using a combination of δ15N of N2, δ18O of O2, δ18Oice and [CH4] measurements. The [CH4] blank of the melt extractions was <4 ppb. Measurements of δ18O and δ15N indicated no significant gas isotopic fractionation from handling. Measured Ar/N2, CFC-11 and CFC-12 in the samples indicated no significant contamination from ambient air. Ar/N2, Kr/Ar and Xe/Ar ratios in the samples were used to quantify effects of gas dissolution during the melt extractions and correct the sample [CH4]. Corrected [CH4] is elevated over expected values by up to 132 ppb for most samples, suggesting some in situ CH4 production in ice at this site.
Phased Array Feed (PAF) technology is the next major advancement in radio astronomy in terms of combining high sensitivity and large field of view. The Focal L-band Array for the Green Bank Telescope (FLAG) is one of the most sensitive PAFs developed so far. It consists of 19 dual-polarization elements mounted on a prime focus dewar resulting in seven beams on the sky. Its unprecedented system temperature of ~17 K will lead to a 3 fold increase in pulsar survey speeds as compared to contemporary single pixel feeds. Early science observations were conducted in a recently concluded commissioning phase of the FLAG where we clearly demonstrated its science capabilities. We observed a selection of normal and millisecond pulsars and detected giant pulses from PSR B1937+21.
Black widows and redbacks are binary systems consisting of a millisecond pulsar in a close binary with a companion having matter driven off of its surface by the pulsar wind. X-rays due to an intrabinary shock have been observed from many of these systems, as well as orbital variations in the optical emission from the companion due to heating and tidal distortion. We have been systematically studying these systems in radio, optical and X-rays. Here we will present an overview of X-ray and optical studies of these systems, including new XMM-Newton and NuStar data obtained from several of them, along with new optical photometry.
The Neutron Star Interior Composition Explorer (NICER) presents an exciting new capability for exploring the modulation properties of X-ray emitting neutron stars, including large area, low background, extremely precise absolute event time stamps, superb low-energy response and flexible scheduling. The Pulsation Searches and Multiwavelength Coordination working group has designed a 2.5 Ms observing program to search for emission and characterize the modulation properties of about 30 known or suspected neutron star sources across a number of source categories. A key early goal will be to search for pulsations from millisecond pulsars that might exhibit thermal pulsations from the surface suitable for pulse profile modeling to constrain the neutron star equation of state. In addition, we will search for pulsations from transitional millisecond pulsars, isolated neutron stars, low-mass X-ray binaries (LMXBs), accretion-powered millisecond pulsars, central compact objects and other sources. We present our science plan and initial results from the first months of the NICER mission, including the discovery of pulsations from the millisecond pulsar J1231–1411.
We have investigated Kelvin-Helmholtz (K-H) instabilities for a homogeneous compressible plasma containing a uniform magnetic field and a linear velocity shear. A derivation of the relevant K-H dispersion equation and details regarding method of solution are given elsewhere (submitted to Mon. Not. R. Astr. Soc.). We present here an outline of our results.
The percutaneous osseointegrated bone conduction device can be associated with more soft tissue complications when compared to the magnetic transcutaneous osseointegrated bone conduction device. This study aimed to determine whether fewer soft tissue complications may result in the transcutaneous osseointegrated bone conduction device being a lower cost option in hearing rehabilitation.
This retrospective case note review included adult patients who underwent implantation with the transcutaneous Cochlear Attract (n = 22) or percutaneous Cochlear DermaLock (n = 25) bone-anchored hearing aids between September 2013 and December 2014. The number of post-operative clinic appointments, complications and treatments undertaken, and calculated cost average, were compared between the two groups.
Although the transcutaneous device was slightly more expensive than the percutaneous device, the percutaneous device was associated with a greater number of soft tissue complications and, as a result, the percutaneous device had significantly higher follow-up costs in the first six months following surgery.
The transcutaneous osseointegrated bone conduction device may represent a more cost-effective method of hearing rehabilitation compared to the percutaneous osseointegrated bone conduction device.
We present wide-field, spatially and highly resolved spectroscopic observations of Balmer filaments in the northeastern rim of Tycho’s supernova remnant in order to investigate the signal of cosmic-ray (CR) acceleration. The spectra of Balmer-dominated shocks (BDSs) have characteristic narrow (FWHM ~ 10 km s−1) and broad (FWHM ~ 1000 km s−1) Hα components. CRs affect the Hα-line parameters: heating the cold neutrals in the interstellar medium results in broadening of the narrow Hα-line width beyond 20 km s−1, but also in reduction of the broad Hα-line width due to energy being removed from the protons in the post-shock region. For the first time we show that the width of the narrow Hα line, much larger than 20 km s−1, is not a resolution or geometric effect nor a spurious result of a neglected intermediate (FWHM ~ 100 km s−1) component resulting from hydrogen atoms undergoing charge exchange with warm protons in the broad-neutral precursor. Moreover, we show that a narrow line width ≫ 20 km s−1 extends across the entire NE rim, implying CR acceleration is ubiquitous, and making it possible to relate its strength to locally varying shock conditions. Finally, we find several locations along the rim, where spectra are significantly better explained (based on Bayesian evidence) by inclusion of the intermediate component, with a width of 180 km s−1 on average.
We have observed the oxygen-rich SNR 1E 0102.2-7219 with the integral field spectrograph WiFeS at Siding Spring Observatory and discovered sulfur-rich ejecta for the first time. Follow-up deep DDT observations with MUSE on the VLT (8100 s on source) reaching down to a noise level of ~5 × 10−20ergs−1cm−2Å−1spaxel−1 have led to the additional discovery of fast-moving hydrogen as well as argon-rich and chlorine-rich material. The detection of fast-moving hydrogen knots challenges the interpretation that the progenitor of 1E 0102 was a compact core of a Wolf-Rayet star that had shed its entire envelope. In addition to the detection of hydrogen and the products of oxygen-burning, this unprecedented sharp (0.2″ spaxel size at ~0.7″ seeing) and deep MUSE view of an oxygen-rich SNR in the Magellanic Clouds reveals further exciting discoveries, including [Fe xiv]λ5303 and [Fe xi]λ7892 emission, which we associate with the forward shock. We present this exciting data set and discuss some of its implications for the explosion mechanism and nucleosynthesis of the associated supernova.