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Guangxi, a province in southwestern China, has the second highest reported number of HIV/AIDS cases in China. This study aimed to develop an accurate and effective model to describe the tendency of HIV and to predict its incidence in Guangxi. HIV incidence data of Guangxi from 2005 to 2016 were obtained from the database of the Chinese Center for Disease Control and Prevention. Long short-term memory (LSTM) neural network models, autoregressive integrated moving average (ARIMA) models, generalised regression neural network (GRNN) models and exponential smoothing (ES) were used to fit the incidence data. Data from 2015 and 2016 were used to validate the most suitable models. The model performances were evaluated by evaluating metrics, including mean square error (MSE), root mean square error, mean absolute error and mean absolute percentage error. The LSTM model had the lowest MSE when the N value (time step) was 12. The most appropriate ARIMA models for incidence in 2015 and 2016 were ARIMA (1, 1, 2) (0, 1, 2)12 and ARIMA (2, 1, 0) (1, 1, 2)12, respectively. The accuracy of GRNN and ES models in forecasting HIV incidence in Guangxi was relatively poor. Four performance metrics of the LSTM model were all lower than the ARIMA, GRNN and ES models. The LSTM model was more effective than other time-series models and is important for the monitoring and control of local HIV epidemics.
This study investigates numerically the performance of applying aerospike nozzle in a hydrogen peroxide mono-propellant propulsion system. A set of governing equations, including continuity, momentum, energy and species conservation equations with extended k-ε turbulence equations, are solved using the finite-volume method. The hydrogen peroxide mono-propellant is assumed to be fully decomposed into water vapor and oxygen after flowing through a catalyst bed before entering the nozzle. The aerospike nozzle is expected to have high performance even in deep throttling cases due to its self-compensating characteristics in a wide range of ambient pressure environments. The results show that the thrust coefficient efficiency (Cf,η) of this work exceeds 90% of the theoretical value with a nozzle pressure ratio (PR) in the range of 20 ~ 45. Many complex gas dynamics phenomena in the aerospike nozzle are found and explained in the paper. In addition, performance of the aerospike nozzle is compared with that of the bell-shape nozzle.
Recent evidence suggests that exercise plays a role in cognition and that the posterior cingulate cortex (PCC) can be divided into dorsal and ventral subregions based on distinct connectivity patterns.
To examine the effect of physical activity and division of the PCC on brain functional connectivity measures in subjective memory complainers (SMC) carrying the epsilon 4 allele of apolipoprotein E (APOE 4) allele.
Participants were 22 SMC carrying the APOE ɛ4 allele (ɛ4+; mean age 72.18 years) and 58 SMC non-carriers (ɛ4–; mean age 72.79 years). Connectivity of four dorsal and ventral seeds was examined. Relationships between PCC connectivity and physical activity measures were explored.
ɛ4+ individuals showed increased connectivity between the dorsal PCC and dorsolateral prefrontal cortex, and the ventral PCC and supplementary motor area (SMA). Greater levels of physical activity correlated with the magnitude of ventral PCC–SMA connectivity.
The results provide the first evidence that ɛ4+ individuals at increased risk of cognitive decline show distinct alterations in dorsal and ventral PCC functional connectivity.
Diarrhea is a common cause of morbidity and mortality and the incidence of diarrhea in the world has changed little over the past four decades. To assess the prevalence of and healthcare practices for diarrhea, a cross-sectional study was conducted in Pudong, Shanghai, China. In October 2014, a total of 5324 community residents were interviewed. Respondents were asked if they had experienced diarrhea (defined as ⩾3 passages of watery, loose, bloody, or mucoid stools within a 24-h period) in the previous month prior to the interview. The monthly prevalence of diarrhea was 4·1% (95% CI: 3·3–4·8), corresponding to an incidence rate of 0·54 episodes per person-year. The proportion of individuals with diarrhea who sought healthcare was 21·2% (95% CI: 13·4–29·0). Diarrhea continues to impose a considerable burden on the community and healthcare system in Pudong. Young age and travel were identified as predictors of increased diarrhea occurrence.
The objectives of this study were to compare the quality-of-life scores of Malaysian children with CHD and their healthy siblings, to determine the level of agreement between proxy-reports and child self-reports, and to examine variables that have an impact on quality of life in those with CHD.
Parental-proxy scores of the Pediatric Quality of Life Inventory 4.0 core scales were obtained for 179 children with CHD and 172 siblings. Intra-class coefficients were derived to determine the levels of proxy–child agreement in 66 children aged 8–18 years. Multiple regression analysis was used to determine factors that impacted Pediatric Quality of Life Inventory scores.
Proxy scores were lower in children with CHD than siblings for all scales except physical health. Maximum differences were noted in children aged 5–7 years, whereas there were no significant differences in the 2–4 and 13–18 years age groups. Good levels of proxy–child agreement were found in children aged 8–12 years for total, psychosocial health, social, and school functioning scales (correlation coefficients 0.7–0.8). In children aged 13–18 years, the level of agreement was poor to fair for emotional and social functioning. The need for future surgery and severity of symptoms were associated with lower scores.
Differences in proxy perception of quality of life appear to be age related. The level of proxy–child agreement was higher compared with other reported studies, with lower levels of agreement in teenagers. Facilitating access to surgery and optimising control of symptoms may improve quality of life in this group of children.
The collision between aqueous drops in air typically leads to coalescence after impact. Rebounding of the droplets with similar sizes at atmospheric conditions is not generated, unless with significantly large pressure or high impact parameters exhibiting near-grazing collision. Here we demonstrate experimentally the creation of a non-coalescent regime through addition of a small amount of water-soluble surfactant. We perform a direct simulation to account for the continuum and short-range flow dynamics of the approaching interfaces, as affected by the soluble surfactant. Based on the immersed-boundary formulation, a conservative scheme is developed for solving the coupled surface-bulk convection–diffusion concentration equations, which presents excellent mass preservation in the solvent as well as conservation of total surfactant mass. We show that the Marangoni effect, caused by non-uniform distributions of surfactant on the droplet surface and surface tension, induces stresses that oppose the draining of gas in the interstitial gap, and hence prohibits merging of the interfaces. In such gas–liquid systems, the repulsion caused by the addition of surfactant, as frequently observed in liquid–liquid systems such as emulsions in the form of an electric double-layer force, was found to be too weak to dominate in the attainable range of interfacial separation distances. These results thus identify the key mechanisms governing the impact dynamics of surfactant-coated droplets in air and imply the potential of using a small amount of surfactant to manipulate impact outcomes, for example, to prevent coalescence between droplets or interfaces in gases.
In long-term care facilities (LTCFs), the elderly are apt to be infected because those with latent tuberculosis infections (LTBIs) are at an increased risk for reactivation and post-primary TB disease. We report an outbreak of TB in staff and residents in a LTCF. An outbreak investigation was conducted after two TB cases were reported from the LTCF. A tuberculin skin test (TST), bacteriological examination and chest radiograph were administered to all facility staff and residents. An outbreak is defined as at least two epidemiologically linked cases that have identical Mycobacterium tuberculosis genotype isolates. This outbreak infected eight residents and one staff member, who were confirmed to have TB in a LTCF between September 2011 and October 2012. Based on the Becker method, the latent and infectious periods were estimated at 223·6 and 55·9 days. Two initial TST-negative resident contacts were diagnosed as TB cases through comprehensive TB screening. Observing elderly people who have a negative TST after TB screening appears to be necessary, given the long latent period for controlling a TB outbreak in a LTCF. It is important to consider providing LTBI treatment for elderly contacts.
Mentalizing deficits are a hallmark of the autism spectrum condition (ASC) and a potential endophenotype for atypical social cognition in ASC. Differences in performance and neural activation on the ‘Reading the Mind in the Eyes’ task (the Eyes task) have been identified in individuals with ASC in previous studies.
Performance on the Eyes task along with the associated neural activation was examined in adolescents with ASC (n = 50), their unaffected siblings (n = 40) and typically developing controls (n = 40). Based on prior literature that males and females with ASC display different cognitive and associated neural characteristics, analyses were stratified by sex. Three strategies were applied to test for endophenotypes at the level of neural activation: (1) identifying and locating conjunctions of ASC–control and sibling–control differences; (2) examining whether the sibling group is comparable to the ASC or intermediate between the ASC and control groups; and (3) examining spatial overlaps between ASC–control and sibling–control differences across multiple thresholds.
Impaired behavioural performance on the Eyes task was observed in males with ASC compared to controls, but only at trend level in females; and no difference in performance was identified between sibling and same-sex control groups in both sexes. Neural activation showed a substantial endophenotype effect in the female groups but this was only modest in the male groups.
Behavioural impairment on complex emotion recognition associated with mental state attribution is a phenotypic, rather than an endophenotypic, marker of ASC. However, the neural response during the Eyes task is a potential endophenotypic marker for ASC, particularly in females.
Uptake of oestrogens into breast tissue and their subsequent metabolism can be studied by infusing radio-labelled steroids into volunteer patients. Such studies show that oestradiol is preferentially accumulated in breast tumours, oestradiol concentrations exceeding those of oestrone. This contrasts with plasma, in which oestrone concentrations in postmenopausal women are greater than those of the oestradiol. This observation suggests that tissue factors can modulate local oestrogen metabolism, and thus local steroid concentrations.
We have studied the local production of oestrogens from androgen, and also the interconversion of the major oestrogens, oestrone and oestradiol. Using isotopic techniques, it is possible to calculate the proportion of endogenous oestrogen produced from androgen, as opposed to uptake from the circulation. These studies suggest that a very variable proportion of tissue oestrogen derives from endogenous synthesis. After administration of aromatase inhibitors, aromatase activity is substantially inhibited, both in vivo and in vitro.
Relative oestrogen concentrations are determined in part by the activity of oestradiol dehydrogenase. In breast tissue, dehydrogenase activity is present and this is modified by various factors, including androgens. In addition, we have demonstrated that normal, benign and malignant breast tissues produce factors which can modulate both growth and dehydrogenase activity of cancer cells in vitro.
We conclude that breast tissue is a site of synthesis of oestrogens, and that a number of factors can affect their local concentration. Tumour cells produce growth factors which can influence steroid metabolism, and may thus be able to enhance favourably their own endocrine environment.
The prevalence and genotype distribution of human papillomavirus (HPV) infection in women with normal cervical cytology varies widely according to the population studied. Two non-overlapping population-based cohort studies of women aged ⩾30 years for the periods 2008–2009 (n=5026) and 2004–2005 (n=10 014) were analysed. The prevalence rate of HPV was 11·0% (95% CI 10·5–11·6). HPV infection was significantly associated with age, menopausal status, and inversely associated with hormone replacement therapy. There was an increasing trend of α3/α15, α5/α6, and multiple HPV infections with increasing age. The five most common types were HPV52, 18, 53, 58 and 70, while HPV16, 31, 33 ranked 21st, 25th, and 16th, respectively, in the merged cohort with normal cytology (n=14 724). HPV16, 31, and 33 were significantly associated with abnormal cytology, which could have resulted in their rarity in the total merged cohort (n=15 040).
Co-sputtering has been used to fabricate equiatomic thin films of TiNi, a shape memory alloy, which form the basis of microactuators with many applications in MEMS. The stress evolution of TiNi films will be described. The performance of the TiNi actuators has been characterized, with regards to actuation force, recoverable strain, time response, and fatigue resistance. The performance of microvalves using these actuators will also be presented.