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Inhibitory control can be divided into motor and cognitive inhibition. The current research is the first study exploring the impact of brief mindfulness training on motor inhibition, measured by a stop signal task in participants without any meditation experience. Motor inhibition performance was compared before and immediately after three different conditions; a brief mindfulness induction, a resting state and an active control session in which participants listened to their favorite music. Post-test learning effect on go-reaction times was seen for the resting and mindfulness conditions, but was absent in the music session, possibly due to emotional arousal might have led slower responses. Brief mindfulness training did not significantly alter inhibitory control, although marginal improvement in stop signal reaction time following the mindfulness induction was observed. Motor inhibition appears unresponsive to either short-term or long-term mindfulness practice. Future mindfulness studies should explore a broad spectrum of cognitive functions and populations.
The Square Kilometre Array (SKA) is a planned large radio interferometer designed to operate over a wide range of frequencies, and with an order of magnitude greater sensitivity and survey speed than any current radio telescope. The SKA will address many important topics in astronomy, ranging from planet formation to distant galaxies. However, in this work, we consider the perspective of the SKA as a facility for studying physics. We review four areas in which the SKA is expected to make major contributions to our understanding of fundamental physics: cosmic dawn and reionisation; gravity and gravitational radiation; cosmology and dark energy; and dark matter and astroparticle physics. These discussions demonstrate that the SKA will be a spectacular physics machine, which will provide many new breakthroughs and novel insights on matter, energy, and spacetime.
In this contribution, we use heavy ion irradiation and photoluminescence (PL) spectroscopy to demonstrate that defects can be used to tailor the optical properties of two-dimensional molybdenum disulfide (MoS2). Sonicated MoS2 flakes were deposited onto Si/SiO2 substrate and subjected to 3 MeV Au2+ ion irradiation at room temperature to fluences ranging from 1 × 1012 to 1 × 1016 cm−2. We demonstrate that irradiation-induced defects can control optical excitations in the inner core shell of MoS2 by binding A1s- and B1s-excitons, and correlate the exciton peaks to the specific defects introduced with irradiation. The systematic increase of ion fluence produced different defect densities in MoS2, which were estimated using B/A exciton ratios and progressively increased with ion fluence. We show that up to the fluences of 1 × 1014 cm−2, the MoS2 lattice remains crystalline and defect densities can be controlled, whereas at higher fluences (≥1 × 1015 cm−2), the large number of introduced defects distorts the excitonic structure of the material. In addition to controlling excitons, defects were used to split bound and free trions, and we demonstrate that at higher fluences (1 × 1015 cm−2), both free and bound trions can be observed in the same PL spectrum. Most importantly, the lifetimes of these states exceed trion and exciton lifetimes in pristine MoS2, and PL spectra of irradiated MoS2 remains unchanged weeks after irradiation experiments. Thus, this work demonstrated the feasibility of engineering novel optical behaviors in low-dimensional materials using heavy ion irradiation. The insights gained from this study will aid in understanding the many-body interactions in low-dimensional materials and may ultimately be used to develop novel materials for optoelectronic applications.
The present study aimed to evaluate the effect of mandatory iodine fortification of bread on the iodine status of South Australian populations using newborn thyroid-stimulating hormone (TSH) concentration as a marker.
The study used an interrupted time-series design.
TSH data collected between 2005 and 2016 (n 211 033) were extracted from the routine newborn screening programme in South Australia for analysis. Iodine deficiency is indicated when more than 3 % of newborns have TSH > 5 mIU/l.
Newborns were classified into three groups: the pre-fortification group (those born before October 2009); the transition group (born between October 2009 and June 2010); and the post-fortification group (born after June 2010).
The percentage of newborns with TSH > 5 mIU/l was 5·1, 6·2 and 4·6 % in the pre-fortification, transition and post-fortification groups, respectively. Based on a segmented regression model, newborns in the post-fortification period had a 10 % lower risk of having TSH > 5 mIU/l than newborns in the pre-fortification group (incidence rate ratio (IRR) = 0·90; 95 % CI 0·87, 0·94), while newborns in the transitional period had a 22 % higher risk of having TSH > 5 mIU/l compared with newborns in the pre-fortification period (IRR = 1·22; 95 % CI 1·13, 1·31).
Using TSH as a marker, South Australia would be classified as mild iodine deficiency post-fortification in contrast to iodine sufficiency using median urinary iodine concentration as a population marker. Re-evaluation of the current TSH criteria to define iodine status in populations is warranted in this context.
The triplite LiFeSO4F displays both the highest potential ever reported for an Fe-based compound, as well as a comparable specific energy with that of popular LiFePO4. The synthesis is still a challenge because the present approaches are connected with long time, special equipments or organic reagents, etc. In this work, the triplite LiFeSO4F powder was synthesized through an ambient two-step solid-state route. The reaction process and phase purity were analyzed, coupled with structure refinement and electrochemical test.
The discovery of the first electromagnetic counterpart to a gravitational wave signal has generated follow-up observations by over 50 facilities world-wide, ushering in the new era of multi-messenger astronomy. In this paper, we present follow-up observations of the gravitational wave event GW170817 and its electromagnetic counterpart SSS17a/DLT17ck (IAU label AT2017gfo) by 14 Australian telescopes and partner observatories as part of Australian-based and Australian-led research programs. We report early- to late-time multi-wavelength observations, including optical imaging and spectroscopy, mid-infrared imaging, radio imaging, and searches for fast radio bursts. Our optical spectra reveal that the transient source emission cooled from approximately 6 400 K to 2 100 K over a 7-d period and produced no significant optical emission lines. The spectral profiles, cooling rate, and photometric light curves are consistent with the expected outburst and subsequent processes of a binary neutron star merger. Star formation in the host galaxy probably ceased at least a Gyr ago, although there is evidence for a galaxy merger. Binary pulsars with short (100 Myr) decay times are therefore unlikely progenitors, but pulsars like PSR B1534+12 with its 2.7 Gyr coalescence time could produce such a merger. The displacement (~2.2 kpc) of the binary star system from the centre of the main galaxy is not unusual for stars in the host galaxy or stars originating in the merging galaxy, and therefore any constraints on the kick velocity imparted to the progenitor are poor.
This study characterized Neisseria meningitidis serogroup C strains in China in order to establish their genetic relatedness and describe the use of multilocus variable-number tandem-repeat (VNTR) analysis (MLVA) to provide useful epidemiological information. A total of 215 N. meningitidis serogroup C strains, obtained from 2003 to 2012 in China, were characterized by MLVA with different published schemes as well as multilocus sequence typing. (i) Based on the MLVA scheme with a combination of five highly variable loci, 203 genotypes were identified; this level of discrimination supports its use for resolving closely related isolates. (ii) Based on a combination of ten low variable loci, clear phylogenetic relationships were established within sequence type complexes. In addition, there was evidence of microevolution of VNTR loci over the decade as strain lineages spread from Anhui to other provinces, the more distant the provinces from Anhui, the higher the genetic variation.
Radiation-tolerant materials, sensors and electronics can enable lightweight space subsystems with reduced packaging requirements and increased operation lifetimes. Such technology can be used within extreme harsh environments related to space exploration, radiation medicine and power generation (combustion and nuclear). Gallium nitride (GaN), a ceramic semiconductor material, is a candidate material due to its stability within high-radiation, high-temperature and chemically corrosive environments. In addition, the wide bandgap of GaN (3.4 eV) can be leveraged for ultraviolet (UV) wavelength photodetection. In metal-semiconductor-metal (MSM) photodetector architectures using Schottky contacts, transparent electrodes (e.g., graphene) can increase sensitivity and improve overall device response. Here we present fabrication and characterization of GaN-based UV photodetectors using graphene electrodes irradiated up to 200 krad total ionizing dose (TID) then tested under UV light and dark conditions. For current-voltage measurements taken at 90, 120 and 200 krad TID, the current-voltage response does not vary significantly. From 90 to 120 krad TID, the responsivity shifts by 2% before dropping off at 200 krad TID. These initial findings suggest that graphene/GaN MSM UV photodetectors can provide robust operation within extreme harsh environments.
We have numerically investigated the development of strong Langmuir turbulence (SLT) and associated electron acceleration at different angles of incidence of ordinary (O) mode pump waves. For angles of incidence within the Spitze cone, the turbulence initially develops within the first maximum of the Airy pattern near the plasma resonance altitude. After a few milliseconds, the turbulent layer shifts downwards by about 1 km. For injections outside the Spitze region, the turning point of the pump wave is at lower altitudes. Yet, an Airy-like pattern forms here, and the turbulence development is quite similar to that for injections within the Spitze. SLT leads to the acceleration of 10–20 eV electrons that ionize the neutral gas thereby creating artificial ionospheric layers. Our numerical modeling shows that most efficient electron acceleration and ionization occur at angles between the magnetic and geographic zenith, where SLT dominates over weak turbulence. Possible effects of the focusing of the electromagnetic beam on magnetic field-aligned density irregularities and the finite heating beam width at the magnetic zenith are also discussed. The results have relevance to ionospheric heating experiments using ground-based, high-power radio transmitters to heat the overhead plasma, where recent observations of artificial ionization layers have been made.
A calculation model is put forward to analyze the interfacial response of an elastic frictionless punch, pressed normally into a half-plane, and subject to bending moment throughout this paper to observe the important effect that different normal loads and bending moments on the contact pressure distribution and contact deformation. Results for the detailed considerations have been given to the specific different cases of ηc. A characteristic response of the punch to a surplus bending moment has been found. The small differences can be observed between both methods show characteristic features of the FEM model and the theoretical model. The presented numerical results illustrate the influences of the normal load and bending moment on the contact stresses. The results obtained can be used to analyze the crack nucleation in fretting when the punch is acted upon by the normal force and the bending moment.
The safety and nutritional adequacy of goat milk infant formulas have been questioned. The primary aim of the present study was to compare the growth and nutritional status of infants fed a goat milk infant formula with those of infants fed a typical whey-based cow milk infant formula. The secondary aim was to examine a range of health- and allergy-related outcomes. A double-blind, randomised controlled trial with 200 formula-fed term infants randomly assigned to receive either goat or cow milk formula from 2 weeks to at least 4 months of age was conducted. A cohort of 101 breast-fed infants was included for comparison. Weight, length and head circumference were measured at 2 weeks and 1, 2, 3, 4, 6 and 12 months of age. Nutritional status was assessed from serum albumin, urea, creatinine, Hb, ferritin, and folate and plasma amino acid concentrations at 4 months. Z-scores for weight, length, head circumference and weight for length were not different between the two formula-fed groups. There were differences in the values of some amino acids and blood biomarkers between the formula-fed groups, but the mean values for biomarkers were within the normal reference range. There were no differences in the occurrence of serious adverse events, general health, and incidence of dermatitis or medically diagnosed food allergy. The incidence of parentally reported blood-stained stools was higher in the goat milk formula-fed group, although this was a secondary outcome and its importance is unclear. Goat milk formula provided growth and nutritional outcomes in infants that did not differ from those provided by a standard whey-based cow milk formula.
In this work, experiments were performed to study the effect of cathode materials on the amplitude of the super-short avalanche electron beam (SAEB) current and X-ray density during discharges in atmospheric-pressure air. In the experiments, discharges were generated by three nanosecond-pulse generators in air gaps between a plane anode and a tubular cathode made of different metals. The output pulse of the three generators had a rise time of 0.3, 1, 15 ns, and a full width at half maximum of 1, 2, 30–40 ns, respectively. For the generators with pulse rise-time of 0.3 and 1 ns, the cathodes used in these experiments were made of stainless steel, permalloy, titanium, niobium, copper, brass, and aluminum. For the generator with pulse rise-time of 15 ns, the cathodes were made of stainless steel, titanium, copper, and aluminum. When the rise time of the applied pulse is 0.3 ns, our experimental results show that the amplitude of the voltage across the gap depends on the cathode material and reaches its maximum value when a stainless steel cathode is used. It is also observed that, under such situation, the maximum amplitudes of the SAEB current occur at maximum voltages across the gap when all other factors are equal. Furthermore, the amplitude of the SAEB current hereof is found to depend not only on the material of the sharp edge of the tubular cathode, but also on the material of the side surface of the tubular cathode. When the rise time of the applied pulse is 1 ns, the experimental results show that the average number of electrons in SAEB is also affected by the cathode materials. In addition, in the case that the rise time of the voltage pulse is 15 ns and the gap spacing is 8 cm, the experimental results show that the cathode material has no effect on the voltage amplitude across the gap and the X-ray density. The increase of the pulse repetition frequency from 250 to 500 Hz under such condition can lead to a three-fold increase in X-ray density in a repetitive pulsed mode.
We study and compare the stellar populations of host galaxies of different types of supernovae (SNe): SN Ia and core collapse SN (SN II and SN Ibc) at the same time. The 234 sample galaxies are selected by cross-matching the Asiago Supernova Catalogue (ASC) and the SDSS-DR7 main galaxy sample (MGS). The STARLIGHT software is used to analyze their stellar populations by fitting the continua and absorption lines of the hosts.
Tenderness is considered as the most important quality determinant of meat. Calcium chloride application has been shown to improve tenderness by regulating endogenous proteinases. This study was designed to determine the effect of 300 mM calcium chloride injection on myofibrillar structures, caspase activities and shear force in longissimus muscles of bulls during postmortem storage of 7 days. Myofibrillar fragmentation index was determined as an index of proteolysis occurring in muscle fibers and associated proteins. Maximum tenderness was observed at days 4 and 7 in both treated and control samples. The injection of calcium chloride significantly increased myofibrillar proteolysis and improved tenderness at postmortem days 4 and 7. The treatment reduced caspase-9 activity at 4 h and day 4, whereas those of caspase-8 and -3 activities at days 1 and 4 with respect to control. The improved tenderness and increased myofibril fragmentation with decreased caspase activities suggested that the proteolytic systems activated with calcium chloride injection possibly behave independent of the caspase system.
Recent studies indicate that bipolar disorder is associated with mitochondrial dysfunction and oxidative stress. Previous studies in our laboratory have shown that the mood stabilizer lithium inhibits oxidative stress. The α,β-unsaturated aldehyde 4-hydroxy-2-nonenal (4-HNE), a major product of lipid peroxidation, is able to exert cytotoxicity and disturb cellular function by forming protein adducts. The purpose of this study is to determine whether chronic lithium treatment prevents 4-HNE-protein adduction in an amphetamine-induced hyperactive mania-like model. We found that repeated amphetamine stimulation significantly induced hyperactive behaviour, decreased activities of mitochondrial complexes I and III, and increased 4-HNE-protein adducts in rat frontal cortex, and that chronic lithium treatment inhibited both amphetamine-induced hyperactivity and 4-HNE-protein adduction. Monoamine neurotransmitters are involved in the aetiology and pathology of bipolar disorder and other psychiatric diseases, and also contribute significantly to amphetamine-induced behavioural effects. Vesicular monoamine transporter 2 (VMAT2) is critical in packaging monoamine neurotransmitters. We found that 4-HNE can form protein adducts with VMAT2. Repeated amphetamine stimulation significantly increased 4-HNE-VMAT2 adducts, while chronic lithium treatment reduced amphetamine-increased 4-HNE-VMAT2 adducts in rat frontal cortex. Our findings suggest that chronic lithium treatment may inhibit amphetamine-induced hyperactive mania-like behaviour by preventing 4-HNE-VMAT2 adduction. This finding also indicates that prevention of 4-HNE-VMAT2 adduction may contribute in part to the pharmacological action of lithium for the treatment of bipolar disorder.
Studies in Western countries have repeatedly shown that women with a history of childhood sexual abuse (CSA) are at increased risk for developing major depression (MD). Would this relationship be found in China?
Three levels of CSA (non-genital, genital, and intercourse) were assessed by self-report in two groups of Han Chinese women: 1970 clinically ascertained with recurrent MD and 2597 matched controls. Diagnostic and other risk factor information was assessed at personal interview. Odds ratios (ORs) were calculated by logistic regression and regression coefficients by linear or Poisson regression.
Any form of CSA was significantly associated with recurrent MD [OR 3.26, 95% confidence interval (CI) 1.95–5.45]. This association strengthened with increasing CSA severity: non-genital (OR 2.47, 95% CI 1.17–5.23), genital (OR 2.77, 95% CI 1.32–5.83) and intercourse (OR 13.35, 95% CI 1.83–97.42). The association between any form of CSA and MD remained significant after accounting for parental history of depression, childhood emotional neglect (CEN), childhood physical abuse (CPA) and parent–child relationship. Among the depressed women, those with CSA had an earlier age of onset, longer depressive episodes and an increased risk for generalized anxiety disorder (GAD; OR 1.92, 95% CI 1.39–2.66) and dysthymia (OR 2.16, 95% CI 1.52–3.09).
In Chinese women CSA is strongly associated with MD and this association increases with greater severity of CSA. Depressed women with CSA have an earlier age of onset, longer depressive episodes and increased co-morbidity with GAD and dysthymia. Although reporting biases cannot be ruled out, our results are consistent with the hypothesis that, as in Western countries, CSA substantially increases the risk for MD in China.