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SN1991bg-like supernovae are a distinct subclass of thermonuclear Type Ia supernovae (SNe Ia). Their spectral and photometric peculiarities indicate that their progenitors and explosion mechanisms differ from ‘normal’ SNe Ia. One method of determining information about supernova progenitors we cannot directly observe is to observe the stellar population adjacent to the apparent supernova explosion site to infer the distribution of stellar population ages and metallicities. We obtain integral field observations and analyse the spectra extracted from regions of projected radius
about the apparent SN explosion site for 11 91bg-like SNe in both early- and late-type galaxies. We utilise full-spectrum spectral fitting to determine the ages and metallicities of the stellar population within the aperture. We find that the majority of the stellar populations that hosted 91bg-like supernovae have little recent star formation. The ages of the stellar populations suggest that that 91bg-like SN progenitors explode after delay times of >6 Gyr, much longer than the typical delay time of normal SNe Ia, which peaks at
Excessive intake of high-energy diets is an important cause of most obesity. The intervention of rats with high-fat diet can replicate the ideal animal model for studying the occurrence of human nutritional obesity. The proteomics and bioinformatics analysis can help us to systematically and comprehensively study the effect of high-fat diet on rat liver. In this study, 4056 proteins were identified in rat liver by using tandem mass tag. A total of 198 proteins were significantly changed, of which 103 were significantly up-regulated and 95 were significantly down-regulated. These significant differentially expressed proteins are primarily involved in lipid metabolism and glucose metabolism processes. The intake of a high-fat diet forces the body to maintain physiological balance by regulating these key protein spots to inhibit fatty acid synthesis, promote fatty acid oxidation, and accelerate fatty acid degradation. This study enriches our understanding of metabolic disorders induced by high-fat diets at the protein level.
Geochronological, major and trace element, and Sr–Nd–Hf isotopic data are reported for the monzonitic rocks of the Fushan pluton in the Taihang Mountains, central North China Craton, in order to investigate their sources, petrogenesis and tectonic implications. Zircon U–Pb dating results reveal that the Fushan pluton was emplaced during the Early Cretaceous (∼126–124 Ma). The monzonites and quartz monzonites are mainly characterized by calc-alkaline and magnesian features and display light rare earth element (LREE) enrichment and flat heavy REE (HREE) patterns with slightly positive Eu anomalies. They have similar whole-rock initial 87Sr/86Sr ratios (0.70653–0.70819), εNd(t) values (−13.6 to −18.6) and zircon εHf(t) values (−21.8 to −17.3). The primary magma of the Fushan pluton was derived from the partial melting of a spinel-facies amphibole-bearing ancient enriched lithospheric mantle. The monzonitic rocks also have high Ba–Sr and low Y and Yb contents, with high Sr/Y and La/Yb ratios. These geochemical features of monzonitic rocks are not only inherited from the magma source but also significantly enhanced by crystal fractionation during magmatic evolution; e.g. hornblende fractionation increased the Ba–Sr concentrations and Sr/Y ratios. During the Early Cretaceous, the slab sinking and roll-back of the Palaeo-Pacific Plate could have created an ancient big mantle wedge beneath East Asia and induced a lithospheric extensional process in the central North China Craton within an intracontinental setting.
In order to reveal the quantitative relationship between fatigue crack deflection path and cross-sectional grain boundary (GB) arrangement of metallic nanolayered composites (NLCs), a stochastic model was established based on the interface-dominant fatigue damage for the ultrafine-scale NLCs. The model indicates that the crack deflection length decreases with decreasing GB arrangement deviation and grain size of constituent layers. The observation and quantitative analysis of fatigue cracking behavior of the Cu/W multilayers with a layer thickness of 5 and 20 nm was conducted to verify the model.
In this study, a new ultra-wideband (UWB) band-edge selectivity antenna with a modified radiation slot using defected ground structure (DGS) is presented to obtain bandpass filtering reflection coefficient and gain performance. The well-designed DGS is designed on backside metallic of the substrate and can be seen as a low-pass filter that provides a good roll-off at a higher frequency. By connecting the DGS and the stepped slot and making them merge with each other, good cut-off property in the upper passband and better in-band impedance characteristics are obtained. Measured results show that the proposed design not only shows good band-edge selectivity in reflection coefficient and gain performance but also has a good impedance matching of −13.5 dB reflection coefficients and a good radiation efficiency of 90% in the operating frequencies. The measured bandwidth defined with the reflection coefficient less than −10 dB is from 3.1–11.2 GHz. Furthermore, the size of the filtering UWB antenna is 22 mm × 12 mm, which is smaller than many individual UWB antennas and UWB filters.
Maternal one-carbon metabolism during pregnancy is crucial for fetal development and programming by DNA methylation. However, evidence on one-carbon biomarkers other than folate is lacking. We, therefore, investigated whether maternal plasma methyl donors, that is, choline, betaine and methionine, are associated with birth outcomes. Blood samples were obtained from 115 women during gestation (median 26·3 weeks, 90 % range 22·7–33·0 weeks). Plasma choline, betaine, methionine and dimethylglycine were measured using HPLC-tandem MS. Multivariate linear and logistic regression models were used to estimate the association between plasma biomarkers and birth weight, birth length, the risk of small-for-gestational-age and large-for-gestational-age (LGA). Higher level of maternal betaine was associated with lower birth weight (–130·3 (95 % CI –244·8, –15·9) per 1 sd increment for log-transformed betaine). Higher maternal methionine was associated with lower risk of LGA, and adjusted OR, with 95 % CI for 1 sd increase in methionine concentration was 0·44 (95 % CI 0·21, 0·89). Stratified analyses according to infant sex or maternal plasma homocysteine status showed that reduction in birth weight in relation to maternal betaine was only limited to male infants or to who had higher maternal homocysteine status (≥5·1 µmol/l). Higher maternal betaine status was associated with reduced birth weight. Maternal methionine was inversely associated with LGA risk. These findings are needed to be replicated in future larger studies.
The average power of diode-pumped fiber lasers has been developed deeply into the kW regime in the past years. However, stimulated Raman scattering (SRS) is still a major factor limiting the further power scaling. Here, we have demonstrated the mitigation of SRS in kilowatt-level diode-pumped fiber amplifiers using a chirped and tilted fiber Bragg grating (CTFBG) for the first time. The CTFBG is designed and inscribed in large-mode-area (LMA) fibers, matching with the operating wavelength of the fiber amplifier. With the CTFBG inserted between the seed laser and the amplifier stage, an SRS suppression ratio of
is achieved in spectrum at the maximum output laser power of 2.35 kW, and there is no reduction in laser slope efficiency and degradation in beam quality. This work proves the feasibility and practicability of CTFBGs for SRS suppression in high-power fiber lasers, which is very useful for the further power scaling.
Mosquitoes are haematophagous vectors for hundreds of pathogenic viruses that are aetiological agents of human diseases. In nature, mosquito-borne viruses maintain a lifecycle between mosquitoes and vertebrate animals. Viruses are acquired by a naive mosquito from an infected host by blood meals and then propagate extensively in the mosquito's tissues. This mosquito then becomes a virus reservoir and is competent to transmit the viruses to a naive vertebrate host through the next blood meal. To survive in and efficiently cycle between two distinct host environments, mosquito-borne viruses have evolved delicate and smart strategies to comprehensively exploit host and vector factors. Here, we provide an update on recent studies of the mechanisms of virus survival in, acquisition and transmission by mosquitoes.
The plerocercoid (sparganum) of Spirometra erinaceieuropaei is the main aetiological agent of human sparganosis. To improve the current knowledge on S. erinaceieuropaei evolution, we performed multi-locus microsatellite typing of sparganum isolates from China for the first time. All available expressed sequence tag (EST) sequences for the Spirometra were downloaded from the GenBank. The identification and localization of microsatellites in ESTs was accomplished by MISA. Based on the selected microsatellites, the genetic structure of 64 sparganum isolates collected from 11 geographical locations in southwest China were investigated through principal component analysis, STRUCTURE analysis and neighbour-joining clustering. A total of 522 non-redundant ESTs containing 915 simple sequence repeats were identified from 12 481 ESTs screened. Five primer pairs were finally selected. Using these loci, a total of 12 alleles were detected in 64 sparganum isolates. Little variability was observed within each of geographical population, especially among isolates derived from Kunming of Yunnan (YN-KM) province. Both STRUCTURE analysis and the clustering analysis supported that two genotypes existed among the sparganum isolates from southwest China. In conclusion, five microsatellite markers were successfully developed, and sparganum population was observed to harbour low genetic variation, further investigation with deeper sampling was needed to elucidate the population structure.
Limited information is available on the prevalence and effect of hypertriglyceridaemic–waist (HTGW) phenotype on the risk of type 2 diabetes mellitus (T2DM) in rural populations.
In the present cross-sectional study, we investigated the prevalence of the HTGW phenotype and T2DM and the strength of their association among rural adults in China.
HTGW was defined as TAG >1·7 mmol/l and waist circumference (WC) ≥90 cm for males and ≥80 cm for females. Logistic regression analysis yielded adjusted odds ratios (aOR) relating risk of T2DM with HTGW.
Adults (n 12 345) aged 22·83–92·58 years were recruited from July to August of 2013 and July to August of 2014 from a rural area of Henan Province in China.
The prevalence of HTGW and T2DM was 23·71 % (males: 15·35 %; females: 28·88 %) and 11·79 % (males: 11·15 %; females: 12·18 %), respectively. After adjustment for sex, age, smoking, alcohol drinking, blood pressure, physical activity and diabetic family history, the risk of T2DM (aOR; 95 % CI) was increased with HTGW (v. normal TAG and WC: 3·23; CI 2·53, 4·13; males: 3·37; 2·30, 4·92; females: 3·41; 2·39, 4·85). The risk of T2DM with BMI≥28·0 kg/m2, simple enlarged WC and simple disorders of lipid metabolism showed an increasing tendency (aOR=1·31, 1·75 and 2·32).
The prevalence of HTGW and T2DM has reached an alarming level among rural Chinese people, and HTGW is a significant risk factor for T2DM.
This paper investigates the relation between media coverage and offering yield spreads using a comprehensive dataset of 5,338 industrial bonds issued from 1990 to 2011. We find that media coverage is negatively associated with firms’ cost of debt. This association is robust to controlling for standard yield determinants, different model specifications, and endogeneity. We identify 4 economic channels through which media coverage influences the cost of debt: Information asymmetry, governance, liquidity, and default risk. Importantly, media coverage has an independent influence beyond the effects of these economic mechanisms and is not a proxy for other firm attributes.
A compact reconfigurable filtering ultra-wideband (UWB) antenna with switchable band-notched functions is proposed. The basic structure of the proposed design is a filtering slot antenna with good band-edge selectivity using stepped impedance resonator feeding line. The reconfigurability is achieved by using two microstrip lines paralleling to the feeding line and two PIN diodes. The reconfigurable structure and bias circuit of the antenna are relatively simple and are not connected to the radiation structure, so they have little negative influence on the radiation characteristics of the antenna. Total four states could be achieved by using two PIN diodes to short the microstrip lines and ground. To verify the performance of the final design, multiple measured and simulated results in frequency and time domain are studied and analyzed. The measured results agreed very well with simulation. Compared with the traditional UWB antenna, the proposed antenna has advantages in size, filtering function in-band and out-of-band, and tunable states for multiple UWB applications.
True ileal digestibility (TID) values of amino acid (AA) obtained using growing rats are often used for the characterisation of protein quality in different foods and acquisition of digestible indispensable amino acid scores (DIAAS) in adult humans. Here, we conducted an experiment to determine the TID values of AA obtained from nine cooked cereal grains (brown rice, polished rice, buckwheat, oats, proso millet, foxtail millet, tartary buckwheat, adlay and whole wheat) fed to growing Sprague–Dawley male rats. All rats were fed a standard basal diet for 7 d and then received each diet for 7 d. Ileal contents were collected from the terminal 20 cm of ileum. Among the TID values obtained, whole wheat had the highest values (P<0·05), and polished rice, proso millet and tartary buckwheat had relatively low values. The TID indispensable AA concentrations in whole wheat were greater than those of brown rice or polished rice (P<0·05), and polished rice was the lowest total TID concentrations among the other cereal grains. The DIAAS was 68 for buckwheat, 47 for tartary buckwheat, 43 for oats, 42 for brown rice, 37 for polished rice, 20 for whole wheat, 13 for adlay, 10 for foxtail millet and 7 for proso millet. In this study, the TID values of the nine cooked cereal grains commonly consumed in China were used for the creation of a DIAAS database and thus gained public health outcomes.
5xxx series aluminum alloys, as Al-4.5Mg-1.0Mn (AA5083), are strengthened by Mg solid solution and work hardening. A drawback of this alloy is the fact that β phase, Al3Mg2, can precipitate on grain boundaries causing sensitization and intergranular corrosion, which is detrimental to the integrity of the structure. Metallography is an important technique to study the grain structure and highly sought for intergranular corrosion evaluation; however, revealing the grains of completely un-sensitized AA5083 is challenging. This paper introduces a new procedure to etch AA5083 samples that were solutionized at 450°C for 1.5 h. The new procedure is a two-step etching method, including a phosphoric acid pre-etching step and a Weck’s reagent coloring step. Solutionized, lightly sensitized, and as-received AA5083 were evaluated, and the grains were observed using optical microscopy. The microetching mechanism was further studied by optical profilometry, atomic force microscopy, scanning electron microscopy, and energy dispersive spectrometry. The phosphoric acid created a surface profile determined by the grain orientations and its reactivity, and the Weck’s reagent was then able to color grains by preferential MnO2 formation over some pre-etched grains. Moreover, the final polishing with colloidal silica was essential to reach a high contrast image.
This study examined whether taking advice is influenced by regulatory fit and whether this effect is reduced or disappears within certain attribution conditions during vocational decision making. Experiment 1 created a vocational decision setting to compare differences in decision makers’ weight of advice (WOA) between ‘eager strategy’ and ‘vigilant strategy’ advice conditions. Results showed no significant main effect of regulatory orientation or advice strategy, but there was a significant interaction. The WOA value, with fit between regulatory focus and advice strategy, was higher than with a fit violation. Experiment 2 examined whether the regulatory fit effect is reduced or disappears within attribution conditions during vocational decision making. Results showed job seekers more easily take others’ advice under the fit condition, and a significant interaction existed between regulatory fit and attribution. Thus, attribution could reduce the influence of the regulatory fit effect. Implications for vocational consultants, job seekers, and advisors are also discussed.
It is difficult to control Holotrichia parallela Motschulsky with chemical insecticides due to the larvae's soil-living habit, thus the pest has caused great economic losses in agriculture. In addition, uridine diphosphate-glycosyltransferases (UGTs) catalyze the glycosylation process of a variety of small lipophilic molecules with sugars to produce water-soluble glycosides, and play multiple roles in detoxification, endobiotic modulation, and sequestration in an insect. Some UGTs were found specifically expressed in antennae of Drosophila melanogaster and Spodoptera littoralis, and glucurono-conjugated odorants could not elicit any olfactory signals, suggesting that the UGTs may play roles in odorant inactivation by biotransformation. In the current study, we performed a genome-wide analysis of the candidate UGT family in the dark black chafer, H. parallela. Based on a UGT gene signature and the similarity of these genes to UGT homologs from other organisms, 20 putative H. parallela UGT genes were identified. Bioinformatics analysis was used to predict sequence and structural features of H. parallela UGT proteins, and revealed important domains and residues involved in sugar donor binding and catalysis by comparison with human UGT2B7. Phylogenetic analysis of these 20 UGT protein sequences revealed eight major groups, including both order-specific and conserved groups, which are common to more than one order. Of these 20 UGT genes, HparUGT1265-1, HparUGT3119, and HparUGT8312 were highly (>100-fold change) expressed in antennae, suggesting a possible role in olfactory tissue, and most likely in odorant inactivation and olfactory processing. The remaining UGT genes were expressed in all tissues (head, thorax, abdomen, leg, and wing), indicating that these UGTs likely have different biological functions. This study provides the fundamental basis for determining the function of UGTs in a highly specialized olfactory organ, the H. parallela antenna.
Previous studies show inconsistent associations between α-linolenic acid (ALA) and risk of CHD. We aimed to examine an aggregate association between ALA intake and risk of CHD, and assess for any dose–response relationship. We searched the PubMed, EMBASE and Web of Science databases for prospective cohort studies examining associations between ALA intake and CHD, including composite CHD and fatal CHD. Data were pooled using random-effects meta-analysis models, comparing the highest category of ALA intake with the lowest across studies. Subgroup analysis was conducted based on study design, geographic region, age and sex. For dose–response analyses, we used two-stage random-effects dose–response models. In all, fourteen studies of thirteen cohorts were identified and included in the meta-analysis. The pooled results showed that higher ALA intake was associated with modest reduced risk of composite CHD (risk ratios (RR)=0·91; 95 % CI 0·85, 0·97) and fatal CHD (RR=0·85; 95 % CI 0·75, 0·96). The analysis showed a J-shaped relationship between ALA intake and relative risk of composite CHD (χ2=21·95, P<0·001). Compared with people without ALA intake, only people with ALA intake <1·4 g/d showed reduced risk of composite CHD. ALA intake was linearly associated with fatal CHD – every 1 g/d increase in ALA intake was associated with a 12 % decrease in fatal CHD risk (95 % CI −0·21, −0·04). Though a higher dietary ALA intake was associated with reduced risk of composite and fatal CHD, the excess composite CHD risk at higher ALA intakes warrants further investigation, especially through randomised controlled trials.
Water level fluctuations of inland lakes are related to regional-scale climate changes, and reflect variations in evaporation, precipitation and glacier meltwater flowing into the lake area in its catchment. In this paper, Ice, Cloud and land Elevation Satellite (ICESat) altimeter data and Landsat imagery (2002-09) are used to estimate Nam Co lake (Nyainqentanglha range, Tibetan Plateau) water elevation changes during 2002-09. In 2003 Nam Co lake covered an area of ~1998.8 ± 4.2 km2 and was situated at 4723 m a.s.l. Over such inland water bodies, ICESat altimeter data offer both wide coverage and spatial and temporal accuracy. We combine remote-sensing and GIS technology to map and reconstruct lake area and increased volume changes during a 7 year time series. Nam Co lake water level increased by 2.4±0.12m (0.33ma–1) between 23 February 2003 and 1 October 2009, and lake volume increased by 4.9 ±0.5 km3. In the past 7 years, Nam Co lake area has increased from 1998.78 ±5.4 to 2023.8 ±3.4 km2, the glacier-covered area has decreased from 832.34 to 821.0 km2 and the drainage basin area has decreased from 201.1 ±4.2 to 196.1 ±2.3 km2. However, the most spectacular feature is the continual water level rise from 2003 to 2009 without an obvious associated increase in precipitation. Based on digital elevation models (DEMs) from Shuttle Radar Topography Mission (SRTM) DEM data and corrected ICESat elevation data, significant changes to glacier mass balance in the western Nyainqentanglha mountains are indicated. Nyainqentanglha mountain glacier surface elevations decreased by 8.39 ± 0.45 m during 2003-09. Over the same period, at least 1.01 km3 of glacial meltwater flowed into Nam Co lake, assuming a glacial runoff coefficient of 0.6. The mean glacier mass-balance value is -490mmw.e. over the corresponding period, indicating that glacier meltwater in the catchment contributes to lake level rise. The contribution rate of glacial meltwater to lake water volume rise is 20.75%. The temporal lake level fluctuation correlates with temperature variations over the same time span.