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In this paper, we study almost proximal extensions of minimal flows. Let
$\pi : (X,T)\rightarrow (Y,T)$
be an extension of minimal flows. Then
$\pi $
is called an almost proximal extension if there is some
$N\in {\mathbb N}$
such that the cardinality of any almost periodic subset in each fiber is not greater than N. When
$N=1$
,
$\pi $
is proximal. We will give the structure of
$\pi $
and give a dichotomy theorem: any almost proximal extension of minimal flows is either almost finite to one, or almost all fibers contain an uncountable strongly scrambled subset. Using the category method, Glasner and Weiss showed the existence of proximal but not almost one-to-one extensions [On the construction of minimal skew products. Israel J. Math.34 (1979), 321–336]. In this paper, we will give explicit such examples, and also examples of almost proximal but not almost finite to one extensions.
This study aimed to analyze the clinical effects of microdissection testicular sperm extraction (micro-TESE) surgery combined with an intracytoplasmic sperm injection (ICSI) regimen in the treatment of non-obstructive azoospermia (NOA) patients with different etiologies. In total, 128 NOA patients participated in this study, in which they received infertility treatment by micro-TESE surgery combined with an ICSI regimen, and all patients were divided into three groups [the Klinefelter syndrome (KS), the idiopathic and the secondary NOA groups]. In addition, the sperm retrieval rate (SRR), fertilization rate, embryo development status and clinical treatment effects were analyzed. Among the 128 NOA patients, the SRR of KS NOA patients was 48.65%, those of idiopathic and the secondary patients were 33.82% and 73.91%, respectively. Regardless of etiologies, there was no correlation with age, hormone value or testicular volume. Further analysis showed that the SRR of the KS group was positively related with testosterone (T) values, and the SRR of the secondary group had a positive relationship with follicle-stimulating hormone or luteinizing hormone values. In the subsequent clinical treatment, the retrieved sperm was subjected to ICSI and achieved good treatment effects, especially in the secondary group, and the implantation rate (55.56%) and clinical pregnancy rate (68.42%) were both higher than those of the idiopathic group (28.75% and 40.00%) and KS group (22.05% and 30.77%). Micro-TESE surgery combined with ICSI insemination is the most effective treatment regimen for NOA patients. The SRR of NOA patients with different etiologies are related to certain specific factors, and micro-TESE surgery seems to be the ideal and only way to have biological children.
Inkjet printing, originally invented for text and pattern printing, is now central to many industrial applications, such as printed electronics, flexible electronics, 3-D printing of mechanical and even biological devices. However, constrained by the droplets’ ejection mechanism, the accuracy of traditional inkjet printing is limited by the size of its orifice, and it is difficult to achieve a volume of droplets at the femtolitre scale, which hinders its further application in the above fields. To this end, we propose the confined interface vibration inkjet printing (CIVIJP) technique, which is capable of printing patterns in a liquid environment with droplet size much smaller than the orifice from which they are dispensed. Here, further systematic study of the mechanism of printing in a liquid environment was carried out with the assistance of a high-speed imaging technique. It is found for the first time that a single pulse stimulation applied on the piezo-ceramic of the inkjet nozzle can trigger damping oscillations of the oil/water interface confined by the orifice, which can last more than 500 $\mathrm {\mu }$s. By adjusting the intensity of single pulse stimulation, the size and quantity of the dispensed droplets can be controlled in a wide range, which is obviously different from traditional droplet ejection in a gaseous environment. This work reveals the underlying physics between the pulse stimulation and the interface behaviours, as well as the physics between the interface behaviours and the size and number of dispensed droplets, enriching the fundamental theory of the inkjet printing in liquid phase.
After patent foramen ovale interventional closure, puncture of the interatrial septum through the occluder is difficult but sometimes needed for further interventional treatment. This paper presents findings from an in vivo experimental study of a reserved atrial septal puncture area patent foramen ovale occluder.
Materials and methods:
A patent foramen ovale model was established in canines using trans-septal puncture of the fossa ovale and high-pressure balloon dilation. Then, patent foramen ovale closure was performed with a reserved atrial septal puncture area and all canines were raised for 3 months. Then, the occluder was crossed and left atrial angiography was performed on the septal area with the occluder. Finally, DSA angiography, echocardiography, and histology were used to evaluate the performance and feasibility of the reserved atrial septal puncture area.
Results:
A patent foramen ovale model was successfully established in 10 canines using the atrial septal puncture method. The average diameter of the patent foramen ovale was 3.77 ±0.19 mm, and the patent foramen ovale was successfully closed in all canines using a reserved atrial septal puncture area. As assessed using transoesophageal echocardiography, the new occluder exhibited an ideal position and was occluded entirely without a residual shunt intraoperatively and postoperatively. A 100% success rate of atrial septum puncture was achieved across the new occluder. The occluders were completely endothelialised 3 months post-implantation.
Conclusions:
The reserved atrial septal puncture area was effective in patent foramen ovale closure and exhibited positive sealing performance and biological compatibility. Trans-septal puncture was feasible and effective after reserved atrial septal puncture area patent foramen ovale closure.
Maternal gestational weight gain (GWG) is an important determinant of infant birth weight, and having adequate total GWG has been widely recommended. However, the association of timing of GWG with birth weight remains controversial. We aimed to evaluate this association, especially among women with adequate total GWG. In a prospective cohort study, pregnant women’s weight was routinely measured during pregnancy, and their GWG was calculated for the ten intervals: the first 13, 14–18, 19–23, 24–28, 29–30, 31–32, 33–34, 35–36, 37–38 and 39–40 weeks. Birth weight was measured, and small-for-gestational-age (SGA) and large-for-gestational-age were assessed. Generalized linear and Poisson models were used to evaluate the associations of GWG with birth weight and its outcomes after multivariate adjustment, respectively. Of the 5049 women, increased GWG in the first 30 weeks was associated with increased birth weight for male infants, and increased GWG in the first 28 weeks was associated with increased birth weight for females. Among 1713 women with adequate total GWG, increased GWG percent between 14 and 23 weeks was associated with increased birth weight. Moreover, inadequate GWG between 14 and 23 weeks, compared with the adequate GWG, was associated with an increased risk of SGA (43 (13·7 %) v. 42 (7·2 %); relative risk 1·83, 95 % CI 1·21, 2·76). Timing of GWG may influence infant birth weight differentially, and women with inadequate GWG between 14 and 23 weeks may be at higher risk of delivering SGA infants, despite having adequate total GWG.
Sporadic clusters of healthcare-associated coronavirus disease 2019 (COVID-19) occurred despite intense rostered routine surveillance and a highly vaccinated healthcare worker (HCW) population, during a community surge of the severe acute respiratory coronavirus virus 2 (SARS-CoV-2) B.1.617.2 δ (delta) variant. Genomic analysis facilitated timely cluster detection and uncovered additional linkages via HCWs moving between clinical areas and among HCWs sharing a common lunch area, enabling early intervention.
There is an ongoing debate on whether wine reviews provide meaningful information on wine properties and quality. However, few studies have been conducted aiming directly at comparing the utility of wine reviews and numeric measurements in wine data analysis. Based on data from close to 300,000 wines reviewed by Wine Spectator, we use logistic regression models to investigate whether wine reviews are useful in predicting a wine's quality classification. We group our sample into one of two binary quality brackets, wines with a critical rating of 90 or above and the other group with ratings of 89 or below. This binary outcome constitutes our dependent variable. The explanatory variables include different combinations of numerical covariates such as the price and age of wines and numerical representations of text reviews. By comparing the explanatory accuracy of the models, our results suggest that wine review descriptors are more accurate in predicting binary wine quality classifications than are various numerical covariates—including the wine's price. In the study, we include three different feature extraction methods in text analysis: latent Dirichlet allocation, term frequency-inverse document frequency, and Doc2Vec text embedding. We find that Doc2Vec is the best performing feature extraction method that produces the highest classification accuracy due to its capability of using contextual information from text documents. (JEL Classifications: C45, C88, D83)
Wines are usually evaluated by wine experts and enthusiasts who give numeric ratings as well as text reviews. While most wine classification studies have been based on conventional statistical models using numeric variables, there has been very limited work on implementing neural network models using wine reviews. In this paper, we apply neural network models (CNN, BiLSTM, and BERT) to extract useful information from wine reviews and classify wines according to different rating classes. Using a large collection of wine reviews from Wine Spectator, the study shows that BERT, a neural network framework recently developed by Google, has the best performance. In the two-class classification (90–100 and 80–89), BERT achieves an accuracy of 89.12%, followed by BiLSTM (88.69%) and CNN (88.02%). In the four-class classification (95–100, 90–94, 85–89, and 80–84), BERT yields an 81.57% accuracy, while the other two produce an 80% accuracy. The neural network models in the paper are independent of domain knowledge and thus can be easily extended to other kinds of text analysis. Expanding the limited work on wine text review classification studies, these models are up-to-date and provide valuable additions to wine data analysis. (JEL Classifications: C45, C88, D83)
Ediacaran cap dolostone atop Marinoan glacial deposits contains complex sedimentary structures with extremely negative δ13Ccarb values in close association with oscillations in palaeoclimatic and oceanographic proxy records. However, the precise geological, geochronological and geochemical context of the cap dolostone is not clarified, which hampers us from correctly interpreting the extremely negative δ13Ccarb values and their causal relationships with the Snowball Earth hypothesis. In this study, we conducted detailed in situ geochronological and geochemical analyses on the calcite within the cap dolostone from the Ediacaran Doushantuo Formation in South China in order to define its formation and relationship to the Snowball Earth hypothesis. Petrographic observations show that formation of dolomite pre-dates precipitation of calcite and pyrite, which pre-dates quartz cementation in the basal cap carbonate. Calcite cement within the cap dolostone yielded a U–Pb age of 636.5 ± 7.4/17.8 Ma (2σ, MSWD = 1.6, n = 36/40), which is within uncertainty of a published dolomite U–Pb age of 632 ± 17 Ma (recalculated as 629.3 ± 16.7/22.9 Ma). These age constraints negate the possibility that the calcite cement was formed by late Ediacaran or Cambrian hydrothermal activity. The rare earth element distribution patterns suggest a dominant seawater origin overprinted by subsequent early Ediacaran hydrothermal activity. The combined age, petrographic and geochemical data suggest oxidization of methane clathrates in response to complicated interplay between eustasy and isostatic rebound and hydrothermal fluids.
To examine the mediating effects of maternal perception of child weight (weight perception) and concern about overweight (weight concern) on the paths between child weight and maternal feeding practices.
Setting:
Pudong District, Shanghai, China.
Participants:
A convenience sample of 1164 mothers who were primary caregivers of preschool children.
Results:
Sixty per cent of the mothers perceived their overweight/obese children as normal weight or even underweight. The disagreement between actual child weight and maternal weight perception was statistically significant (Kappa = 0·212, P < 0·001). Structural equation modelling indicated that weight perception fully mediated the relationship between child BMI Z-scores and pressure to eat. Weight concern fully mediated the relationships between child BMI Z-scores and the other three feeding practices. The serial mediating effects of weight perception and concern were statistically significant for the paths between child BMI Z-score and monitoring (β = 0·035, P < 0·001), restriction (β = 0·022, P < 0·001), and food as a reward (β = –0·017, P < 0·05).
Conclusion:
Child weight may influence maternal feeding practices through weight perception and concern. Thus, interventions are needed to increase the accuracy of weight perception, which may influence several maternal feeding practices and thereby contribute to child health.
This study aimed to determine the risk factors for chronic diseases and to identify the potential influencing mechanisms from the perspectives of lifestyle and dietary factors. The findings could provide updated and innovative evidence for the prevention and control of chronic diseases.
Design:
A cross-sectional study.
Setting:
Shanghai, China.
Participants:
1005 adults from Yangpu district of Shanghai participated in the study, and responded to questions on dietary habits, lifestyle and health status.
Results:
Residents suffering from chronic diseases accounted for about 34·99 % of the respondents. Logistic regression analysis showed that age, diet quality, amount of exercise and tea drinking were related to chronic diseases. Age > 60 and overeating (Diet Balance Index total score > 0) had negative additive interaction on the occurrence of chronic disease, while overexercise (Physical Activity Index > 17·1) and tea drinking had negative multiplicative interaction and negative additive interaction on the occurrence of chronic disease. Diet quality, physical activity and tea drinking were incomplete mediators of the relationship between types of medical insurance residents participating in and chronic diseases.
Conclusions:
The residents in Yangpu District of Shanghai have a high prevalence of chronic diseases. Strengthening access of residents to health education and interventions to prevent chronic diseases and cultivating healthy eating and exercise habits of residents are crucial. The nutritional environment of the elderly population should be considered, and the reimbursement level of different types of medical insurance should be designed reasonably to improve the accessibility of medical and health services and reduce the risk of chronic diseases.
In recent years, the controlling nutritional status (CONUT) score has increasingly became an effective indicator associated with tumor prognosis. This study was conducted to synthesise data on the prognostic value of CONUT score on patients with upper tract urothelial carcinoma (UTUC) or renal cell carcinoma (RCC) undergoing nephrectomy. We designed and performed a systematic analysis of studies that verified the correlation between preoperative CONUT score and prognosis for UTUC and RCC using PubMed, Web of Science and Embase. The conclusion was clarified by pooled hazard ratios (HR) and 95% confidence intervals (95% CI). Subgroup analysis were further conducted in accordance with different primary tumor. Six studies involving 3529 patients were included in this evidence synthesis, which revealed that the CONUT score had a potential role to predict the survival of UTUC and RCC patients accepting surgery. Pooled analysis showed that the overall survival (OS, HR 2·32, p < 0·0001), cancer-specific survival (CSS, HR 2·68, p < 0·0001) and disease-free survival (DFS, HR 1·62, p < 0·00001) were inferior in the high CONUT score group when compared with low score group. Subgroup analysis revealed that this result was in line with UTUC (OS: HR 1·86, p = 0·02; CSS: HR 2·24, p = 0·01; DFS: HR 1·54, p < 0·00001) and RCC (OS: HR 3·05, p < 0·00001; CSS: HR 3·47, p < 0·00001; DFS: HR 2·21, p = 0·0005) patients respectively. Consequently, the CONUT score is a valuable preoperative index to predict the survival of patients with UTUC or RCC undergoing nephrectomy.
Paraguay is a landlocked country in South America. It is a democratic low-middle-income nation, and the Ministry of Public Health and Social Welfare is responsible for its healthcare system. Mental health services receive just 1–2% of healthcare budgets, and there are only 1.6 psychiatrists per 100 000 inhabitants. There are insufficient resources to adequately assess and treat mental disorders in high-risk populations such as children, adolescents and prisoners. Despite several improvements to mental health policies within the past two decades, the nation still lacks a Mental Health Act and specific policies required to optimise the mental health of the population.
Food insecurity has been shown to be associated with fast-food consumption. However, to date, studies on this specific topic are scarce. Therefore, the aim of the present study was to investigate the association between food insecurity and fast-food consumption in adolescents aged 12–15 years from sixty-eight countries (seven low-income, twenty-seven lower middle-income, twenty upper middle-income, fourteen high-income countries). Cross-sectional, school-based data from the Global School-based Student Health Survey were analysed. Data on past 30-d food insecurity (hunger) and fast-food consumption in the past 7 d were collected. Multivariable logistic regression and meta-analysis were conducted to assess associations. Models were adjusted for age, sex and BMI. There were 180 164 adolescents aged 12–15 years (mean age 13·8 (sd 1·0) years; 50·8 % boys) included in the analysis. Overall, severe food insecurity (i.e. hungry because there was not enough food in home most of the time or always) was associated with 1·17 (95 % CI 1·08, 1·26) times higher odds for fast-food consumption. The estimates pooled by country-income levels were significant in low-income countries (adjusted OR (aOR) = 1·30; 95 % CI 1·05, 1·60), lower middle-income countries (aOR = 1·15; 95 % CI 1·02, 1·29) and upper middle-income countries (aOR = 1·26; 95 % CI 1·07, 1·49), but not in high-income countries (aOR = 1·04; 95 % CI 0·88, 1·23). The mere co-occurrence of food insecurity and fast-food consumption is of public health importance. To tackle this issue, a strong governmental and societal approach is required to utilise effective methods as demonstrated in some high-income countries such as the implementation of food banks and the adoption of free school meals.
Classification of wines with a large number of correlated covariates may lead to classification results that are difficult to interpret. In this study, we use a publicly available dataset on wines from three known cultivars, where there are 13 highly correlated variables measuring chemical compounds of wines. The goal is to produce an efficient classifier with straightforward interpretation to shed light on the important features of wines in the classification. To achieve the goal, we incorporate principal component analysis (PCA) in the k-nearest neighbor (kNN) classification to deal with the serious multicollinearity among the explanatory variables. PCA can identify the underlying dominant features and provide a more succinct and straightforward summary over the correlated covariates. The study shows that kNN combined with PCA yields a much simpler and interpretable classifier that has comparable performance with kNN based on all the 13 variables. The appropriate number of principal components is chosen to strike a balance between predictive accuracy and simplicity of interpretation. Our final classifier is based on only two principal components, which can be interpreted as the strength of taste and level of alcohol and fermentation in wines, respectively. (JEL Classifications: C10, Cl4, D83)
Single-shot laser-induced damage threshold (LIDT) measurements of multi-type free-standing ultrathin foils were performed in a vacuum environment for 800 nm laser pulses with durations τ ranging from 50 fs to 200 ps. The results show that the laser damage threshold fluences (DTFs) of the ultrathin foils are significantly lower than those of corresponding bulk materials. Wide band gap dielectric targets such as SiN and formvar have larger DTFs than semiconductive and conductive targets by 1–3 orders of magnitude depending on the pulse duration. The damage mechanisms for different types of targets are studied. Based on the measurement, the constrain of the LIDTs on the laser contrast is discussed.
In this article we establish the arithmetic purity of strong approximation for certain semisimple simply connected linear algebraic groups and their homogeneous spaces over a number field $k$. For instance, for any such group $G$ and for any open subset $U$ of $G$ with ${\mathrm {codim}}(G\setminus U, G)\geqslant 2$, we prove that (i) if $G$ is $k$-simple and $k$-isotropic, then $U$ satisfies strong approximation off any finite number of places; and (ii) if $G$ is the spin group of a non-degenerate quadratic form which is not compact over archimedean places, then $U$ satisfies strong approximation off all archimedean places. As a consequence, we prove that the same property holds for affine quadratic hypersurfaces. Our approach combines a fibration method with subgroup actions developed for induction on the codimension of $G\setminus U$, and an affine linear sieve which allows us to produce integral points with almost-prime polynomial values.
The docking simulators are significant ground test equipment for aerospace projects. The fidelity of docking simulation highly depends on the accuracy performance. This paper investigates the kinematic accuracy for the developed docking simulator. A novel kinematic calibration method which can reduce the number of parameters for error modeling is presented. The principle of parameters separation is studied. A simplified error model is derived based on Taylor series. This method can contribute to the simplification of the error model, fewer measurements, and easier convergence during the parameters identification. The calibration experiment validates this method for further accuracy enhancement.