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Lush ‘oases’ of life seen in chemosynthetic ecosystems such as hot vents and cold seeps represent rare, localized exceptions to the generally oligotrophic deep ocean floor. Organic falls, best known from sunken wood and whale carcasses, are additional sources of such oases. Kemp Caldera (59°42'S, 28°20'W) in the Weddell Sea exhibits active hydrothermal vents and a natural whale fall in close proximity, where an undescribed cocculinid limpet was found living in both types of chemosynthetic habitats. This represents the first member of the gastropod order Cocculinida discovered from hot vents, and also the first record from the Southern Ocean. Here, we applied an integrative taxonomy framework incorporating traditional dissection, electron microscopy, genetic sequencing and 3D anatomical reconstruction through synchrotron computed tomography in order to characterize this species. Together, our data revealed an unusual member of the genus Cocculina with a highly modified radula for feeding on bacterial film, described herein as Cocculina enigmadonta n. sp. Its phylogenetically derived position within the largely wood-inhabiting Cocculina indicates that it probably evolved from an ancestor adapted to living on sunken wood, providing a compelling case of the ‘stepping stone’ evolutionary trajectory from organic falls to seeps and vents.
Studies have shown that mental health problems during pregnancy have adverse effects on fetal growth. The impact of depressive and anxiety symptoms during pregnancy on the fetus have not yet been examined in Singapore.
To examine the association between mental health problems during the second trimester of pregnancy on the quality of the pregnancy, reflected by birth weight and birth length of the newborn.
This study aims to understand the importance of mental health during pregnancy on the development of the child in an Asian population.
Preliminary data of a prospective cohort study of pregnant women (GUSTO), were followed from pregnancy onwards. At 26 weeks of the pregnancy, the Edinburgh Postnatal Depression Scale (EPDS), the Beck Depression Inventory (BDI) and the State Trait Anxiety Inventory (STAI) were administered. Data on birth parameters were collected from medical records.
Linear regression analyses of preliminary data show negative correlations between depressive symptoms measured with EPDS (n = 1025, P = 0.54), BDI (n = 1012, P = 0.001), and anxiety symptoms measured with STAI (n = 1023, P = 0.002) and birth length (corrected for gestational age and gender). No associations were found for birth weight.
There is an association between depressive and anxiety symptoms reported at the end of the second trimester of the pregnancy and birth length, but not birth weight, of the newborn. As it is known that fetal length increases mainly in the second trimester, it suggests that stress of the mother influences the development of the fetus during this trimester.
The advantage of alcohol–calcium method on the formation and the stability of vaterite against ethanol–water binary solvents (EWBS) method was studied through comparative experiment. The polymorphs and morphologies of CaCO3 were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). XRD results show that vaterite slowly decreases from 90.4 to 82.5% as increasing aging time from 0 to 1320 min in alcohol–calcium system, while quickly decreases from 46.5% to 0% at the same aging time in EWBS system. The similar variation as reaction temperature was found in both systems. SEM images indicate that calcite presents its typical rhombohedral morphology in both systems, while the morphologies of vaterite particles in two systems are different. In alcohol–calcium system, small vaterite nanoparticles aggregate into spherical microparticles, and these microparticles become porous, loose, and irregular, even incomplete, as increasing aging time and reaction temperature, while in EWBS system, vaterite nanoparticles aggregate into irregular microparticles. The advantage of alcohol–calcium method was discussed from the formation of the complex compound CaCl2·n(C2H5OH) in alcohol and its decomplexation in aqueous medium.
Abnormal effort-based decision-making represents a potential mechanism underlying motivational deficits (amotivation) in psychotic disorders. Previous research identified effort allocation impairment in chronic schizophrenia and focused mostly on physical effort modality. No study has investigated cognitive effort allocation in first-episode psychosis (FEP).
Cognitive effort allocation was examined in 40 FEP patients and 44 demographically-matched healthy controls, using Cognitive Effort-Discounting (COGED) paradigm which quantified participants’ willingness to expend cognitive effort in terms of explicit, continuous discounting of monetary rewards based on parametrically-varied cognitive demands (levels N of N-back task). Relationship between reward-discounting and amotivation was investigated. Group differences in reward-magnitude and effort-cost sensitivity, and differential associations of these sensitivity indices with amotivation were explored.
Patients displayed significantly greater reward-discounting than controls. In particular, such discounting was most pronounced in patients with high levels of amotivation even when N-back performance and reward base amount were taken into consideration. Moreover, patients exhibited reduced reward-benefit sensitivity and effort-cost sensitivity relative to controls, and that decreased sensitivity to reward-benefit but not effort-cost was correlated with diminished motivation. Reward-discounting and sensitivity indices were generally unrelated to other symptom dimensions, antipsychotic dose and cognitive deficits.
This study provides the first evidence of cognitive effort-based decision-making impairment in FEP, and indicates that decreased effort expenditure is associated with amotivation. Our findings further suggest that abnormal effort allocation and amotivation might primarily be related to blunted reward valuation. Prospective research is required to clarify the utility of effort-based measures in predicting amotivation and functional outcome in FEP.
How do periods of conflict and peace shape women's empowerment around the world? While existing studies have demonstrated that gender inequalities contribute to the propensity for armed conflict, we consider how the anticipation and realization of armed conflict shape women's opportunities for influence in society. Some scholars have pointed to the role that militarization and threat play in entrenching male dominance, while others have argued that periods of warfare can upend existing gender hierarchical orders. We posit mechanisms by which the preparation for and experiences during war affect change in women's empowerment. We develop and test observable implications using cross-national data from 1900 to 2015. We find that, at least in the short and medium term, warfare can disrupt social institutions and lead to an increase in women's empowerment via mechanisms related to role shifts across society and political shifts catalyzed by war. Reforming institutions and mainstreaming gender during peace processes stand to have important legacies for gender power relations in postconflict societies, though much more may be needed for more permanent change.
Febrile seizure (FS) in children is a common complication of infections with respiratory viruses and hand, foot and mouth disease (HFMD). We conducted a retrospective ecological time-series analysis to determine the temporal relationship between hospital attendances for FS and HFMD or respiratory virus infections. Epilepsy attendance was used as a control. Data from 2004 to 2012 FS and epilepsy hospital attendance, HFMD notifications to the Ministry of Health and from laboratory-confirmed viral respiratory infections among KK Women's and Children's Hospital inpatients were used. A multivariate linear regression analysis was conducted to evaluate the relationship between FS and the virus time series. Relative risks of FS by age were calculated using Bayesian statistical methods. Paediatric accident and emergency (A&E) attendances for FS were found to be associated with influenza A (extra 0.47 FS per influenza A case), B (extra 0.32 per influenza B case) and parainfluenza 3 (extra 0.35 per parainfluenza type 3 case). However, other viruses were not significantly associated with FS. None of the viruses were associated with epileptic seizure attendance. Influenza A, B and parainfluenza 3 viruses contributed to the burden of FS resulting in A&E attendance. Children at risk of FS should be advised to receive seasonal influenza vaccination.
Synthetic photonic materials created by engineering the profile of refractive index or gain/loss distribution, such as negative-index metamaterials or parity-time-symmetric structures, can exhibit electric and magnetic properties that cannot be found in natural materials, allowing for photonic devices with unprecedented functionalities. In this article, we discuss two directions along this line—non-Hermitian photonics and topological photonics—and their applications in nonreciprocal light transport when nonlinearities are introduced. Both types of synthetic structures have been demonstrated in systems involving judicious arrangement of optical elements, such as optical waveguides and resonators. They can exhibit a transition between different phases by adjusting certain parameters, such as the distribution of refractive index, loss, or gain. The unique features of such synthetic structures help realize nonreciprocal optical devices with high contrast, low operation threshold, and broad bandwidth. They provide promising opportunities to realize nonreciprocal structures for wave transport.
Several previous prospective studies suggest that consumption of green leafy and cruciferous vegetables may lower the risk of type 2 diabetes (T2D). We investigated the association between consumption of different types of vegetables in relation to T2D risk in an Asian Population. We included 45 411 participants (age range: 45–74 years) of the Singapore Chinese Health Study (SCHS) free of diabetes, cancer or CVD at baseline (1993–1998). Dietary information was collected using a validated FFQ. Physician-diagnosed incident diabetes was reported at follow-up I (1999–2004) and II (2006–2010) interviews. Cox proportional hazards regression was used to estimate hazard ratio (HR) and 95 % CI of T2D risk. An updated meta-analysis was also conducted to summarise results for green leafy and cruciferous vegetables. During 494 741 person-years of follow-up, 5207 incident T2D occurred. After adjustment for potential confounders, neither total vegetables (top v. bottom quintile HR=1·08; 95 % CI 0·98, 1·18, Ptrend=0·66) nor specific vegetables including dark green leafy vegetables (HR=1·05; 95 % CI 0·96, 1·15, Ptrend=0·21) and cruciferous vegetables (HR=0·97; 95 % CI 0·88, 1·06, Ptrend=0·29) were substantially associated with risk of T2D. A meta-analysis (eleven studies with 754 729 participants and 58 297 cases) including the SCHS and all previous prospective studies suggested borderline significant inverse associations between green leafy (summary relative risk (RR)=0·91; 95 % CI 0·84, 1·00) and cruciferous vegetable consumption (RR=0·87; 95 % CI 0·76, 1·00) and T2D risk, with moderate-to-high heterogeneity. In conclusion, green leafy or cruciferous vegetable consumption was not substantially associated with risk of T2D in an Asian population. Meta-analysis of available cohort data indicated that evidence for a beneficial effect of green leafy or cruciferous vegetable consumption on T2D risk is not convincing.
The quality of prenatal maternal mental health, from psychological stress and depressive symptoms to anxiety and other nonpsychotic mental disorders, profoundly affects fetal neurodevelopment. Despite the evidence for the influence of positive mental well-being on health, there is, to our knowledge, no research examining the possible effects of positive antenatal mental health on the development of the offspring. Using exploratory bifactor analysis, this prospective study (n = 1,066) demonstrated the feasibility of using common psychiatric screening tools to examine the effect of positive maternal mental health. Antenatal mental health was assessed during 26th week of pregnancy. The effects on offspring were assessed when the child was 12, 18, and 24 months old. Results showed that positive antenatal mental health was uniquely associated with the offspring's cognitive, language and parentally rated competences. This study shows that the effects of positive maternal mental health are likely to be specific and distinct from the sheer absence of symptoms of depression or anxiety.
To achieve more accurate navigation performance in the landing process, a multi-resolution visual positioning technique is proposed for landing assistance of an Unmanned Aerial System (UAS). This technique uses a captured image of an artificial landmark (e.g. barcode) to provide relative positioning information in the X, Y and Z axes, and yaw, roll and pitch orientations. A multi-resolution coding algorithm is designed to ensure the UAS will not lose the detection of the landing target due to limited visual angles or camera resolution. Simulation and real world experiments prove the performance of the proposed technique in positioning accuracy, detection accuracy, and navigation effect. Two types of UAS are used to verify the generalisation of the proposed technique. Comparison experiments to state-of-the-art techniques are also included with the results analysis.
Fragile X mental retardation 1 (FMR1) full-mutation expansion causes fragile X syndrome. Trans-generational fragile X syndrome transmission can be avoided by preimplantation genetic diagnosis (PGD). We describe a robust PGD strategy that can be applied to virtually any couple at risk of transmitting fragile X syndrome. This novel strategy utilises whole-genome amplification, followed by triplet-primed polymerase chain reaction (TP-PCR) for robust detection of expanded FMR1 alleles, in parallel with linked multi-marker haplotype analysis of 13 highly polymorphic microsatellite markers located within 1 Mb of the FMR1 CGG repeat, and the AMELX/Y dimorphism for gender identification. The assay was optimised and validated on single lymphoblasts isolated from fragile X reference cell lines, and applied to a simulated PGD case and a clinical in vitro fertilisation (IVF)-PGD case. In the simulated PGD case, definitive diagnosis of the expected results was achieved for all ‘embryos’. In the clinical IVF-PGD case, delivery of a healthy baby girl was achieved after transfer of an expansion-negative blastocyst. FMR1 TP-PCR reliably detects presence of expansion mutations and obviates reliance on informative normal alleles for determining expansion status in female embryos. Together with multi-marker haplotyping and gender determination, misdiagnosis and diagnostic ambiguity due to allele dropout is minimised, and couple-specific assay customisation can be avoided.
The ‘Shinkai Seep Field’ is a serpentinite-hosted chemosynthetic ecosystem in the Southern Mariana Forearc. In June 2015 the site was revisited and a number of rissoiform gastropods were collected. Taxonomic investigations revealed that these specimens represent a hitherto undescribed species of Provanna (Gastropoda: Abyssochrysoidea), described herein as Provanna cingulata n. sp. This new species is characterized by numerous spiral keels, lack of significant axial sculpture, rounded and inflated whorls, and large size for the genus. With the shell height exceeding 16.5 mm (may reach 20 mm), it is the largest Provanna species known thus far. Phylogenetic analysis using 411 bp of the cytochrome oxidase c subunit I (COI) gene confirmed its systematic placement within the genus Provanna. This is the only gastropod from a family endemic to chemosynthetic ecosystems thus far known from the ‘Shinkai Seep Field’. Furthermore, with a collection depth of 5687 m, it represents the deepest known bathymetric range for the superfamily Abyssochrysoidea as a whole.
The existing literature dealing with mutual interactions between the extent of oil dependence and the possibility of belief-driven fluctuations unanimously ignores international loans. This simplified assumption disregards the fact that the relative magnitude of the financial account and the trade account exhibits an increasing trend. Faced with this deficiency in the literature, this paper develops a real business cycle model featuring oil dependence in domestic production and international loans, and examines whether both the presence of international borrowings and the dependence on imported energy will govern the emergence of belief-driven fluctuations.
Maternal vitamin D status during pregnancy has been associated with infant birth and postnatal growth outcomes, but reported findings have been inconsistent, especially in relation to postnatal growth and adiposity outcomes. In a mother–offspring cohort in Singapore, maternal plasma vitamin D was measured between 26 and 28 weeks of gestation, and anthropometric measurements were obtained from singleton offspring during the first 2 years of life with 3-month follow-up intervals to examine birth, growth and adiposity outcomes. Associations were analysed using multivariable linear regression. Of a total of 910 mothers, 13·2 % were vitamin D deficient (<50 nmol/l) and 26·5 % were insufficient (50–75 nmol/l). After adjustment for potential confounders and multiple testing, no statistically significant associations were observed between maternal vitamin D status and any of the birth outcomes – small for gestational age (OR 1·00; 95 % CI 0·56, 1·79) and pre-term birth (OR 1·16; 95 % CI 0·64, 2·11) – growth outcomes – weight-for-age z-scores, length-for-age z-scores, circumferences of the head, abdomen and mid-arm at birth or postnatally – and adiposity outcomes – BMI, and skinfold thickness (triceps, biceps and subscapular) at birth or postnatally. Maternal vitamin D status in pregnancy did not influence infant birth outcomes, postnatal growth and adiposity outcomes in this cohort, perhaps due to the low prevalence (1·6 % of the cohort) of severe maternal vitamin D deficiency (defined as of <30·0 nmol/l) in our population.
Findings from observational studies have suggested a possible relation between Ca and breast cancer risk. However, the results of these studies are inconclusive, and the dose–response relationship between Ca intake and risk of breast cancer remains to be determined. A meta-analysis of prospective studies was conducted to address these issues. PubMed and Embase databases were searched for relevant studies concerning the association between Ca intake and breast cancer up to March 2016. The summary relative risks (RR) with 95 % CI were calculated with a random-effects model. The final analysis included eleven prospective cohort studies involving 26 606 cases and 872 895 participants. The overall RR of breast cancer for high v. low intake of Ca was 0·92 (95 % CI 0·85, 0·99), with moderate heterogeneity (P=0·026, I2=44·2 %). In the subgroup analysis, the inverse association appeared stronger for premenopausal breast cancer (RR 0·75; 95 % CI 0·59, 0·96) than for postmenopausal breast cancer (RR 0·94; 95 % CI 0·87, 1·01). Dose–response analysis revealed that each 300 mg/d increase in Ca intake was associated with 2 % (RR 0·98; 95 % CI 0·96, 0·99), 8 % (RR 0·92; 95 % CI 0·87, 0·98) and 2 % (RR 0·98; 95 % CI 0·97, 0·99) reduction in the risk of total, premenopausal and postmenopausal breast cancer, respectively. Our findings suggest an inverse dose–response association between Ca intake and risk of breast cancer.