To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Neuroimaging characteristics have demonstrated disrupted functional organization in schizophrenia (SZ), involving large-scale networks within grey matter (GM). However, previous studies have ignored the role of white matter (WM) in supporting brain function.
Using resting-state functional MRI and graph theoretical approaches, we investigated global topological disruptions of large-scale WM and GM networks in 93 SZ patients and 122 controls. Six global properties [clustering coefficient (Cp), shortest path length (Lp), local efficiency (Eloc), small-worldness (σ), hierarchy (β) and synchronization (S) and three nodal metrics [nodal degree (Knodal), nodal efficiency (Enodal) and nodal betweenness (Bnodal)] were utilized to quantify the topological organization in both WM and GM networks.
At the network level, both WM and GM networks exhibited reductions in Eloc, Cp and S in SZ. The SZ group showed reduced σ and β only for the WM network. Furthermore, the Cp, Eloc and S of the WM network were negatively correlated with negative symptoms in SZ. At the nodal level, the SZ showed nodal disturbances in the corpus callosum, optic radiation, posterior corona radiata and tempo-occipital WM tracts. For GM, the SZ manifested increased nodal centralities in frontoparietal regions and decreased nodal centralities in temporal regions.
These findings provide the first evidence for abnormal global topological properties in SZ from the perspective of a substantial whole brain, including GM and WM. Nodal centralities enhance GM areas, along with a reduction in adjacent WM, suggest that WM functional alterations may be compensated for adjacent GM impairments in SZ.
Few studies have investigated the association between maternal dietary patterns (DP) during pregnancy, derived from reduced-rank regression (RRR), and fetal growth. This study aims to identify DP during pregnancy associated with macro- and micronutrient intakes, using the RRR method, and to examine their relationship with birth weight (BW). We used data of 7194 women from a large-scale cross-sectional survey in Northwest China. Dietary protein, carbohydrate, haem Fe density and the ratio of PUFA and MUFA:SFA were used as the intermediate variables in the RRR model to extract DP. Generalised estimating equation models were applied to evaluate the associations between DP and BW and related outcomes (including BW z-score, low birth weight (LBW) and small for gestational age (SGA)). Four DP during pregnancy were identified. Socio-demographically disadvantaged pregnant women were more likely to have lower BW and lower adherence to DP1 (high legumes, soyabean products, vegetables and animal-source foods, with relative low wheat and oils). Women with medium and high adherence to DP1 had significantly increased BW (medium 28·6 (95 % CI 7·1, 50·1); high 25·2 (95 % CI 2·7, 47·6)) and BW z-score and had significantly reduced risks of LBW and SGA. The associations were stronger among women with babies <3100 g. There is no association between other DP and outcomes. Higher adherence to the DP that was high in legumes, soyabean products, vegetables and animal-source foods was associated with improved BW in the Chinese pregnant women, particularly among those with disadvantageous socio-demographic conditions.
In 2018, the Alliance for Open Media (AOMedia) finalized its first video compression format AV1, which is jointly developed by the industry consortium of leading video technology companies. The main goal of AV1 is to provide an open source and royalty-free video coding format that substantially outperforms state-of-the-art codecs available on the market in compression efficiency while remaining practical decoding complexity as well as being optimized for hardware feasibility and scalability on modern devices. To give detailed insights into how the targeted performance and feasibility is realized, this paper provides a technical overview of key coding techniques in AV1. Besides, the coding performance gains are validated by video compression tests performed with the libaom AV1 encoder against the libvpx VP9 encoder. Preliminary comparison with two leading HEVC encoders, x265 and HM, and the reference software of VVC is also conducted on AOM's common test set and an open 4k set.
We aimed to comprehensively examine the association of breast-feeding, types and initial timing of complementary foods with adolescent cognitive development in low- and middle-income countries. We conducted a prospective cohort study of 745 adolescents aged 10–12 years who were born to women who participated in a randomised trial of prenatal micronutrient supplementation in rural Western China. An infant feeding index was constructed based on the current WHO recommendations. Full-scale intelligence quotient (FSIQ) was assessed and derived by the fourth edition of the Wechsler Intelligence Scale for Children. The duration of exclusive or any breast-feeding was not significantly associated with adolescent cognitive development. Participants who regularly consumed Fe-rich or Fe-fortified foods during 6–23 months of age had higher FSIQ than those who did not (adjusted mean differences 4·25; 95 % CI 1·99, 6·51). For cows’/goats’ milk and high protein-based food, the highest FSIQ was found in participants who initially consumed at 10–12 and 7–9 months, respectively. A strong dose–response relationship of the composite infant feeding index was also identified, with participants in the highest tertile of overall feeding quality having 3·03 (95 % CI 1·37, 4·70) points higher FSIQ than those in the lowest tertile. These findings suggest that appropriate infant feeding practices (breast-feeding plus timely introduction of appropriate complementary foods) were associated with significantly improved early adolescent cognitive development scores in rural China. In addition, improvement in Fe-rich or Fe-fortified foods complementary feeding may produce better adolescent cognitive development outcomes.
Endometrial injury is an important cause of intrauterine adhesion (IUA), amenorrhea and infertility in women, with limited effective therapies. Recently, stem cells have been used in animal experiments to repair and improve injured endometrium. To date, our understanding of adipose-derived stem cells (ADSCs) in endometrial injury repair and their further therapeutic mechanisms is incomplete. Here, we examined the benefit of ADSCs in restoration of injured endometrium by applying a rat endometrial injury model. The results revealed by immunofluorescence showed that green fluorescent protein (GFP)-labelled ADSCs can differentiate into endometrial epithelial cells in vivo. At 30 days after ADSCs transplantation, injured endometrium was significantly improved, with increased microvessel density, endometrial thickness and glands when compared with the model group. Furthermore, the fertility of rats with injured endometrium in ADSCs group was improved and had a higher conception rate (60% vs 20%, P = 0.014) compared with the control phosphate-buffered saline (PBS) group. However, there was no difference in the control group compared with the sham group. In addition, expression levels of the oestrogen receptor Eα/β (ERα, ERβ) and progesterone receptor (PR) detected by western blot and enzyme-linked immunosorbent assay (ELISA) were higher in the ADSCs group than in the PBS group. Taken together, these results suggested that ADSC transplantation could improve endometrial injury as a novel therapy for IUA.
The effect of maternal folate intake on small-for-gestational-age (SGA) births remains inconclusive. The present study aimed to investigate the associations of maternal folate intake from diet and supplements with the risk of SGA births using data from a cross-sectional study in Shaanxi Province of Northwest China. A total of 7307 women who were within 12 months (median 3; 10th–90th percentile 0–7) after delivery were included. Two-level models were adopted to examine the associations of folate (dietary folate, supplemental folic acid and total folate) intake with the risk of SGA births and birth weight Z score, controlling for a minimum set of confounders that were identified in a directed acyclic graph. Results showed that a higher supplemental folic acid intake during the first trimester was negatively associated with the risk of SGA births (≤60 d v. non-use: OR 0·80; 95 % CI 0·66, 0·96; >60 d v. non-use: OR 0·78; 95 % CI 0·65, 0·94; Ptrend = 0·010; per 10-d increase: OR 0·97; 95 % CI 0·95, 0·99). A higher total folate intake during pregnancy was associated with a reduced risk of SGA births (highest tertile v. lowest tertile: OR 0·77; 95 % CI 0·64, 0·94; Ptrend = 0·010; per one-unit increase in the log-transformed value: OR 0·81; 95 % CI 0·69, 0·95). A similar pattern was observed for the birth weight Z score. Our study suggested that folic acid supplementation during the first trimester and a higher total folate intake during pregnancy were associated with a reduced risk of SGA births.
Objective: Deficits in the semantic learning strategy were observed in subjects with amnestic mild cognitive impairment (aMCI) in our previous study. In the present study, we explored the contributions of executive function and brain structure changes to the decline in the semantic learning strategy in aMCI. Methods: A neuropsychological battery was used to test memory and executive function in 96 aMCI subjects and 90 age- and gender-matched healthy controls (HCs). The semantic clustering ratio on the verbal learning test was calculated to evaluate learning strategy. Medial temporal lobe atrophy (MTA) and white matter hyperintensities (WMH) were measured on MRI with the MTA and Fazekas visual rating scales, respectively. Results: Compared to HCs, aMCI subjects had poorer performance in terms of memory, executive function, and the semantic clustering ratio (P < .001). In aMCI subjects, no significant correlation between learning strategy and executive function was observed. aMCI subjects with obvious MTA demonstrated a lower semantic clustering ratio than those without MTA (P < .001). There was no significant difference in the learning strategies between subjects with high-grade WMH and subjects with low-grade WMH. Conclusion: aMCI subjects showed obvious impairment in the semantic learning strategy, which was attributable to MTA but independent of executive dysfunction and subcortical WMH. These findings need to be further validated in large cohorts with biomarkers identified using volumetric brain measurements. (JINS, 2019, 25, 706–717)
Dynamic trajectory prediction is an important topic in the field of navigation and positioning. Due to the drawbacks of a Global Navigation Satellite System (GNSS) receiver, the trajectory of the position always lags behind the dynamic platform's actual position, especially in highly dynamic situations. In order to solve the prediction of a dynamic trajectory, a generalised extension extrapolated model is proposed in this paper. The model utilises the current motion state and a priori position data of the platform, combines the interpolation and fitting method, adds the angle information as a constraint condition and solves the platform position prediction. In this paper, the feasibility of the generalised extended extrapolation algorithm is analysed theoretically and practically. Simulation results show that the prediction error is within 0.2 metres and experimental results show that the algorithm still has high prediction accuracy when a land vehicle platform is turned through a large angle.
The aim of this study was to investigate the in vivo degradation mechanism and the mechanical properties of poly(lactide-co-glycolide)/beta-tricalcium phosphate (PLGA/β-TCP) composite anchors. Anchors composed of PLGA and β-TCP were implanted in the dorsal subcutaneous tissue of beagle dogs for 6, 12, 16, and 26 weeks. The degradation of the materials was evaluated by measuring the changes in thermal behavior, crystallinity, and mechanical properties. Scanning electron microscope (SEM) was used to observe the surface and longitudinal section of the material. The evaluation of mechanical strength retention and degradation properties suggest that the addition of β-TCP particles efficiently enhances their mechanical properties and thermal characteristics and delays their degradation rate. By analyzing the results of SEM, X-ray diffraction, and differential scanning calorimetry, we can infer that after 12 weeks, the connection between β-TCP and PLGA becomes less compact, which accelerates the decline of mechanical strength.
This study was conducted to investigate the protective effects of l-threonine (l-Thr) supplementation on growth performance, inflammatory responses and intestinal barrier function of young broilers challenged with lipopolysaccharide (LPS). A total of 144 1-d-old male chicks were allocated to one of three treatments: non-challenged broilers fed a basal diet (control group), LPS-challenged broilers fed a basal diet without l-Thr supplementation and LPS-challenged broilers fed a basal diet supplemented with 3·0 g/kg l-Thr. LPS challenge was performed intraperitoneally at 17, 19 and 21 d of age, whereas the control group received physiological saline injection. Compared with the control group, LPS challenge impaired growth performance of broilers, and l-Thr administration reversed LPS-induced increase in feed/gain ratio. LPS challenge elevated blood cell counts related to inflammation, and pro-inflammatory cytokine concentrations in serum (IL-1β and TNF-α), spleen (IL-1β and TNF-α) and intestinal mucosa (jejunal interferon-γ (IFN-γ) and ileal IL-1β). The concentrations of intestinal cytokines in LPS-challenged broilers were reduced by l-Thr supplementation. LPS administration increased circulating d-lactic acid concentration, whereas it reduced villus height, the ratio between villus height and crypt depth and goblet density in both jejunum and ileum. LPS-induced decreases in jejunal villus height, intestinal villus height:crypt depth ratio and ileal goblet cell density were reversed with l-Thr supplementation. Similarly, LPS-induced alterations in the intestinal mRNA abundances of genes related to intestinal inflammation and barrier function (jejunal toll-like receptor 4, IFN-γ and claudin-3, and ileal IL-1β and zonula occludens-1) were normalised with l-Thr administration. It can be concluded that l-Thr supplementation could attenuate LPS-induced inflammatory responses and intestinal barrier damage of young broilers.
In this study, we present clay mineral records from a late Pleistocene loess-paleosol sequence in the Ili Basin, Central Asia, and assess their significance for paleoclimatic reconstruction. The results show that the clay minerals are mainly illite (average 60%) and chlorite (28%), with minor kaolinite (9%) and smectite (3%). Illite was of detrital origin with no obvious modification to its crystal structure. Increases in illite content in the loess are ascribed to wind intensity rather than pedogenesis. High proportions of illite in the clay fraction, and of muscovite in the bulk samples of the paleosol units, may lead to an overestimation of the weathering intensity. Kaolinite was likely inherited from the sedimentary rocks, while chlorite might have been inherited from both sedimentary and metamorphic rocks. The paleoclimatic signals of kaolinite and chlorite were unclear, due to reworking by both fluvial and eolian systems. Smectite was more likely formed by the transformation of biotite and illite, and its variation in the loess sequence was also controlled by wind intensity; this was largely due to aggregation and is unlikely to reflect moisture changes. Although the interpretation of paleoclimate evolution may contain some uncertainties, clay mineralogy does provide the possibility of tracing dust provenance.
Tomographic particle image velocimetry (TPIV) measurement with six high-resolution charge-coupled device (CCD) cameras is conducted to investigate flow structures over a finite circular cylinder with an aspect ratio of 2 (
). This short wall-mounted cylinder is fully immersed in a thick turbulent boundary layer (
). Focus is placed on the three-dimensional instantaneous vortex structures and their dynamic characteristics in the wake flow fields. Based on the present results, a refined topological model of the mean wake field behind the finite circular cylinder is proposed, where the spatial locations of the typical vortex structures and their interactions are described in more detail. Among the reported typical vortex structures (i.e. the horseshoe, tip, base, trailing and arch vortex), emphasis is laid on discussion of the tip and arch vortex. The instantaneous 3D M-shape arch vortex and an alternating large-scale streamwise vortex are first found in the present experiment, and their developments are also discussed. Therefore, it is suggested that the instantaneous finite-cylinder wake is dominated by the arch vortex system and the large-scale streamwise vortices. Moreover, in the instantaneous volumetric flow fields, both the antisymmetric and the symmetric wake behaviours are observed. With proper orthogonal decomposition (POD) analysis, the dynamic characteristics of the wake field are clarified. Different from the flow around an infinite cylinder without control, the third and fourth POD modes are characterized by low-frequency symmetric shedding. The low-frequency feature shown in the second mode pair is observed and associated with the occurrence of instantaneous symmetric 3D wake behaviour triggered by the low-aspect-ratio effect and the extension of the separated shear layer. The low frequency seems be attributed to the flapping phenomenon, i.e. oscillation of the recirculation in the backward-facing step flow. It is found that the flapping motion has a modulating effect on the occurrence of the antisymmetric shedding vortex and thus the large-scale streamwise vortex.
In this work, we investigate the numerical approximation of the compressible Navier-Stokes equations under the framework of discontinuous Galerkin methods. For discretization of the viscous and heat fluxes, we extend and apply the symmetric direct discontinuous Galerkin (SDDG) method which is originally introduced for scalar diffusion problems. The original compressible Navier-Stokes equations are rewritten into an equivalent form via homogeneity tensors. Then, the numerical diffusive fluxes are constructed from the weak formulation of primal equations directly without converting the second-order equations to a first-order system. Additional numerical flux functions involving the jump of second order derivative of test functions are added to the original direct discontinuous Galerkin (DDG) discretization. A number of numerical tests are carried out to assess the practical performance of the SDDG method for the two dimensional compressible Navier-Stokes equations. These numerical results obtained demonstrate that the SDDG method can achieve the optimal order of accuracy. Especially, compared with the well-established symmetric interior penalty (SIP) method , the SDDG method can maintain the expected optimal order of convergence with a smaller penalty coefficient.
Previous studies have yielded conflicting results on the associations of maternal Fe intake with birth outcomes. This study aimed to investigate the associations between maternal Fe intake (total Fe from diet and supplements, dietary total Fe, haeme Fe, non-haeme Fe and Fe supplements use) and adverse birth outcomes in Shaanxi Province of Northwest China. In all, 7375 women were recruited using a stratified multistage random sampling method at 0–12 months (median 3; 10th–90th percentile 0–7) after delivery. Diets were collected by a validated FFQ and maternal characteristics were obtained via a standard questionnaire. The highest tertile of haeme Fe intake compared with the lowest tertile was negatively associated with low birth weight (LBW) (OR 0·68; 95 % CI 0·49, 0·94), small for gestational age (SGA) (OR 0·76; 95 % CI 0·62, 0·94) and birth defects (OR 0·55; 95 % CI 0·32, 0·89). Maternal haeme Fe intake was associated with a lower risk of intra-uterine growth retardation (IUGR) (medium tertile v. lowest tertile: OR 0·78; 95 % CI 0·61, 0·95; highest tertile v. lowest tertile: OR 0·76; 95 % CI 0·59, 0·93; Ptrend=0·045). The OR of LBW associated with Fe supplements use were as follows: during pregnancy: 0·72 (95 % CI 0·50, 0·95); in the second trimester: 0·67 (95 % CI 0·42, 0·98); in the third trimester: 0·47 (95 % CI 0·24, 0·93). We observed no associations of total Fe, dietary total Fe or non-haeme Fe intake with birth outcomes. The results suggest that maternal haeme Fe intake is associated with a reduced risk of LBW, SGA, IUGR and birth defects, and Fe supplements use during pregnancy reduces LBW risk.
To describe nutrient intakes, characterize dietary patterns and analyse their associations with sociodemographic characteristics among pregnant women in Shaanxi, China.
Population-based cross-sectional survey.
Twenty counties and ten districts in Shaanxi Province of Northwest China, 2013.
Women (n 7462) were recruited using a stratified multistage random sampling method to report diets during pregnancy, at 0–12 months (median 3 months; 10th–90th percentile, 0–7 months) after delivery.
Pregnant women had higher intakes of fat, niacin and vitamin E than the nutrient reference values, while most micronutrients such as vitamin A, folate, Ca and Zn were reportedly low. Women in the highest education, occupation and household income groups had higher nutrient intakes than those in the lowest groups. Nutrient intake differences also existed by geographic area, residence and maternal age at delivery. Three dietary patterns were identified: balanced pattern, vegetarian pattern and snacks pattern. Participants with high balanced pattern scores tended to be better educated, wealthier, 25–29 years old at delivery, working outside and living in urban areas and central Shaanxi. Women with high scores on the vegetarian pattern and snacks pattern tended to be in low balanced pattern score groups, and had lower nutrient intakes than those in the high balanced pattern score groups.
The study suggested that pregnant women in Shaanxi, China had low intakes of most nutrients such as vitamin A, folate and Ca. Dietary patterns and most nutrient intakes varied by sociodemographic characteristics. Targeted programmes are needed to improve dietary intakes and dietary patterns among sociodemographically disadvantaged groups.
The Endangered giant panda Ailuropoda melanoleuca is one of the most threatened mammals. The species has experienced declines in its population and habitat as a result of human disturbance. We investigated the influence of human disturbance on habitat use by giant pandas in the Daxiangling Mountains, in China's Sichuan Province. We mapped all signs of giant panda and all locations of seven types of human disturbance in the study area. We used correlation analysis, generalized linear models, and Akaike information criteria to analyse the influence of the various types of human disturbances on habitat use by the giant panda. Our results showed that habitat use was positively correlated with elevation and distance from roads, residences, hydropower stations and logging or tree-felling sites, but negatively correlated with distance from bamboo shoot collection sites and trap sites. We found that the road-effect zone spanned a distance of c. 1,200 m and that human residence could affect the intensity of habitat use by giant pandas at distances > 2,500 m. The effect of roads on habitat use was probably influenced by the association of roads with residences, hydropower stations and mines. In the area occupied by giant pandas, we recommend increased regulation to minimize the expansion and impact of roads, residences, hydropower stations and logging activities.
In this study, scanning electron microscope, electron backscatter diffraction, and transmission electron microscope have been used to investigate the microstructure evolution of Cu–0.2Mg alloy during continuous extrusion in mass production. The continuous extrusion could change the size and orientation of as-cast crystallite grains of the alloy. Hardness increased gently in upsetting zone and dropped sharply in adhesion zone. Hardness reached the maximum value in right-angle bending zone; and it decreased rapidly in extending extrusion zone. Upsetting zone was mainly composed of cell blocks and microbands, and adhesion zone mainly consisted of discontinuous recrystallize grain. Shear band and subgrains were formed in right-angle bending zone due to polygonization during shear deformation. In extending extrusion zone and extrusion rod zone, recrystallize microstructures were predominant.