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The oscillatory Kelvin–Helmholtz (K–H) instability of a planar liquid sheet was experimentally investigated in the presence of an axial oscillating gas flow. An experimental system was initiated to study the oscillatory K–H instability. The surface wave growth rates were measured and compared with theoretical results obtained using the authors’ early linear method. Furthermore, in a larger parameter range experimentally studied, it is interesting that there are four different unstable modes: first disordered mode (FDM), second disordered mode (SDM), K–H harmonic unstable mode (KHH) and K–H subharmonic unstable mode (KHS). These unstable modes are determined by the oscillating amplitude, oscillating frequency and liquid inertia force. The frequencies of KHH are equal to the oscillating frequency; the frequency of KHS equals half the oscillating frequency, while the frequencies of FDM and SDM are irregular. By considering the mechanism of instability, the instability regime maps on the relative Weber number versus liquid Weber number (Werel–Wel) and the Weber number ratio versus the oscillating frequency (Werel/Wel–$\varOmega$s2) were plotted. Among these four modes, KHS is the most unexpected: the frequency of this mode is not equal to the oscillating frequency, but the surface wave can also couple with the oscillating gas flow. Linear instability theory was applied to divide the parameter range between the different unstable modes. According to linear instability theory, K–H and parametric unstable regions both exist. However, note that all four modes (KHH, KHS, FDM and SDM) corresponded primarily to the K–H unstable region obtained from the theoretical analysis. Nevertheless, the parametric unstable mode was also observed when the oscillating frequency and amplitude were relatively low, and the liquid inertia force was relatively high. The surface wave amplitude was small but regular, and the evolution of this wave was similar to that of Faraday waves. The wave oscillating frequency was half that of the surface wave.
Given the rising burden of palliative care and the limited human resources for its facilitation in China, volunteers are becoming increasingly indispensable. In particular, there is a high demand for volunteers who can serve as spiritual caregivers. However, a volunteer’s ability to provide good spiritual care in a palliative setting may be influenced by their attitude toward palliative care. To uncover the current state of spiritual caregiving in palliative settings in China and insights into best practices for its improvement, this study measured spiritual care competence and identified its influencing factors and explored its relationship with attitudes toward palliative care among volunteers. Notably, this study is the first to consider spiritual care competence alongside attitudes toward palliative care.
A descriptive cross-sectional study using online survey methods was conducted with 385 volunteers in Shanghai, China. Data were collected using a structured questionnaire.
Volunteers demonstrated relatively low levels of spiritual care competence (58.50 ± 10.92). Statistically significant correlations were found between spiritual care competence and the following variables: age, educational background, marital status, religious beliefs, occupational status, and relevant training and practical experience. Attitude toward palliative care significantly correlated with spiritual care competence (r = 0.49, p < 0.001).
Significance of results
To continually improve volunteers’ spiritual care competence, diversified education and training programs about spiritual care should be designed for different kinds of volunteers; moreover, because attitude toward palliative care significantly impacted spiritual care competence, such programs should encourage positive attitudes toward palliative care.
Similar to research on risky choice, the traditional analysis of intertemporal choice takes the view that an individual behaves so as to maximize the discounted sum of all future utilities. The well-known Allais paradox contradicts the fundamental postulates of maximizing the expected value or utility of a risky option. We describe a violation of the law of diminishing marginal utility as well as an intertemporal version of the Allais paradox.
Everyone faces uncertainty on a daily basis. Two kinds of probability expressions, verbal and numerical, have been used to characterize the uncertainty that we face. Because our cognitive concept of living things differs from that of non-living things, and distinguishing cognitive concepts might have linguistic markers, we designed four studies to test whether people use different probability expressions when faced with animate or inanimate uncertainty. We found that verbal probability is the preferred way to express animate uncertainty, whereas numerical probability is the preferred way to express inanimate uncertainty. The “verbal-animate” and “numerical-inanimate” associations were robust enough to persist when tested with forced-choice response patterns regardless of the information (e.g., equally likely outcomes, frequencies, or personal beliefs) used to construct probabilities of events. When the response pattern was changed to free-responses, the associations were evident unless the subjects were asked to write their own probability predictions for vague uncertainty. Given that the world around us consists of both animate (i.e., living) and inanimate (i.e., non-living) things, “verbal-animate” and “numerical-inanimate” associations may play a major role in risk communication and may otherwise be useful for practitioners and consultants.
By manipulating the scale in graphs, this study demonstrated a new evaluation bias caused by attribute salience in graphical representations. That is, (de)compressing the graph axis scale changed the relative distance with respect to the options of a given attribute and thus changed the salience of the information in graphical representations. Experiment 1 showed that the differences in the graphical representations had a significant impact on the evaluation. Experiment 2 repeated the scale manipulation effect in a different scenario and extended it to a multi-options context. Experiment 3 disentangled the effect of scale distance manipulation from the other variables (e.g., scale resolution and assignment of attributes to axes) and further supported the finding of Experiment 1. These results indicated that attribute salience in graphical representations clearly affects evaluations and that graphs can be manipulated to cause very different impressions of the same data. This finding is not consistent with the axioms of normative economic theory. Experiment 3 also tested the attribute importance hypothesis, but the evidence indicated that the participants did not regard the longer axis as the more important attribute. Finally, we related our findings to the impact of visual processing on decision making and discussed them from the perspective of two-system cognitive theory.
According to the positive time-discounting assumption of intertemporal decision-making, people prefer to undergo negative events in the future rather than in the present. However, negative discounting has been identified in the intertemporal choice and loss domains, which refers to people’s preference to experience negative events earlier rather than later. Studies have validated and supported the "anticipated dread" as an explanation for negative discounting. This study again explored the effect of anticipated dread on intertemporal choice using content analysis; that is, having participants identify anticipated dread among reasons for negative discounting. This study also validated the effect of anticipated dread on negative discounting by manipulating anticipated dread. This study adds empirical and direct evidence for the role of anticipated dread in negative discounting.
In “The value of nothing: asymmetric attention to opportunity costs drives intertemporal decision making” Read, Olivola and Hardisty (2017) proposed an asymmetric subjective opportunity cost (ASOC) effect to explain and predict why impatience can be detected in intertemporal choice. This work deserves to be replicated and extended for its novel and potentially important findings. The present study aimed to examine the reliability and robustness of the evidence presented by Read et al. by conducting precise replications of their key findings in Study 1. The ASOC effect (Read, et al., 2017) was important for expanding its application and reported to be typically stronger when baseline larger-but-later option (LL) and smaller-but-sooner option (SS) preferences were closer to 50% in the authors’ original condition. Therefore, the present study also aimed to replicate and test the ASOC effect when baseline LL preferences were higher or lower than those in the original condition. We intended to set two additional conditions wherein either LL or SS is more obviously favored (i.e., baseline LL preferences were higher or lower than those in the original condition) by respectively applying the common difference effect (Kirby & Herrnstein, 1995) and the unit effect (Burson, Larrick & Lynch Jr., 2009; Pandelaere, Briers & Lembregts, 2011). Having successfully generated two more obviously favored conditions, the ASOC effect was replicated and confirmed under the original condition and one additional condition wherein SS was more obviously favored. However, the ASOC effect was not detected under the other additional condition wherein LL was more obviously favored. The implications of these findings were discussed.
Whether starchy and non-starchy vegetables have distinct impacts on health remains unknown. We prospectively investigated the intake of starchy and non-starchy vegetables in relation to mortality risk in a nationwide cohort. Diet was assessed using 24-h dietary recalls. Deaths were identified via the record linkage to the National Death Index. Hazard ratios (HR) and 95 % CI were calculated using Cox regression. During a median follow-up of 7·8 years, 4904 deaths were documented among 40 074 participants aged 18 years or older. Compared to those with no consumption, participants with daily consumption of ≥ 1 serving of non-starchy vegetables had a lower risk of mortality (HR = 0·76, 95 % CI 0·66, 0·88, Ptrend = 0·001). Dark-green and deep-yellow vegetables (HR = 0·79, 95 % CI 0·63, 0·99, Ptrend = 0·023) and other non-starchy vegetables (HR = 0·80, 95 % CI 0·70, 0·92, Ptrend = 0·004) showed similar results. Total starchy vegetable intake exhibited a marginally weak inverse association with mortality risk (HR = 0·89, 95 % CI 0·80, 1·00, Ptrend = 0·048), while potatoes showed a null association (HR = 0·93, 95 % CI 0·82, 1·06, Ptrend = 0·186). Restricted cubic spline analysis suggested a linear dose–response relationship between vegetable intake and death risk, with a plateau at over 300 and 200 g/d for total and non-starchy vegetables, respectively. Compared with starchy vegetables, non-starchy vegetables might be more beneficial to health, although both showed a protective association with mortality risk. The risk reduction in mortality plateaued at approximately 200 g/d for non-starchy vegetables and 300 g/d for total vegetables.
The potential of artificial intelligence (AI) has grown exponentially in recent years, which not only generates value but also creates risks. AI systems are characterised by their complexity, opacity and autonomy in operation. Now and in the foreseeable future, AI systems will be operating in a manner that is not fully autonomous. This signifies that providing appropriate incentives to the human parties involved is still of great importance in reducing AI-related harm. Therefore, liability rules should be adapted in such a way to provide the relevant parties with incentives to efficiently reduce the social costs of potential accidents. Relying on a law and economics approach, we address the theoretical question of what kind of liability rules should be applied to different parties along the value chain related to AI. In addition, we critically analyse the ongoing policy debates in the European Union, discussing the risk that European policymakers will fail to determine efficient liability rules with regard to different stakeholders.
Human immunodeficiency virus (HIV) has been widely prevalent among older men (aged ≥50 years old) in Sichuan Province. The study aimed to discover associated factors with the new HIV infection in older men, and provide a scientific basis for the prevention and control of acquired immunodeficiency syndrome (AIDS) in this group. A cross-sectional survey study of newly reported HIV/AIDS and general male residents aged 50 years and older was conducted between April and June 2019, with a resample of respondents to identify cases and controls, followed by a case–control study. Logistic regression was applied to analyse the association between the selected factors and new HIV infection among older men. At last, 242 cases and 968 controls were included. The results of multiple logistic regression suggested that many factors including living alone/concentrated (OR 1.56, 95% CI 1.20–2.04, P = 0.001), have a history of migrant worker (OR 2.10, 95% CI 1.61–2.73, P < 0.001), have commercial sexual behaviour (OR 1.71, 95% CI 1.32–2.22, P < 0.001), married (OR 0.48, 95% CI 0.37–0.64, P < 0.001), have a history of HIV antibody testing (OR 0.73, 95% CI 0.56–0.96, P = 0.026), HIV-related knowledge (OR 0.55, 95% CI 0.42–0.72, P < 0.001) were associated with new HIV infection among older men. The present study revealed some potential risky/protective factors altogether. The results highlighted the direction of HIV/AIDS prevention and control among older men, and it is a social issue that requires the joint participation of the whole society.
This study evaluated the association between inflammatory diets as measured by the Dietary Inflammatory index (DII), inflammation biomarkers and the development of preeclampsia among the Chinese population. We followed the reporting guidelines of the Strengthening the Reporting of Observational Studies in Epidemiology statement for observational studies. A total of 466 preeclampsia cases aged over 18 years were recruited between March 2016 and June 2019, and 466 healthy controls were 1:1 ratio matched by age (±3 years), week of gestation (±1 week) and gestational diabetes mellitus. The energy-adjusted DII (E-DII) was computed based on dietary intake assessed using a seventy-nine item semiquantitative FFQ. Inflammatory biomarkers were analysed by ELISA kits. The mean E-DII scores were −0·65 ± 1·58 for cases and −1·19 ± 1·47 for controls (P value < 0·001). E-DII scores positively correlated with interferon-γ (rs = 0·194, P value = 0·001) and IL-4 (rs = 0·135, P value = 0·021). After multivariable adjustment, E-DII scores were positively related to preeclampsia risk (Ptrend < 0·001). The highest tertile of E-DII was 2·18 times the lowest tertiles (95 % CI = 1·52, 3·13). The odds of preeclampsia increased by 30 % (95 % CI = 18 %, 43 %, P value < 0·001) for each E-DII score increase. The preeclampsia risk was positively associated with IL-2 (OR = 1·07, 95 % CI = 1·03, 1·11), IL-4 (OR = 1·26, 95 % CI = 1·03, 1·54) and transforming growth factor beta (TGF-β) (OR = 1·17, 95 % CI = 1·06, 1·29). Therefore, proinflammatory diets, corresponding to higher IL-2, IL-4 and TGF-β levels, were associated with increased preeclampsia risk.
The objective of this study was to examine the relationships between students’ perceptions of their school policies and environments (i.e. sugar-sweetened beverages (SSB) free policy, plain water drinking, vegetables and fruit eating campaign, outdoor physical activity initiative, and the SH150 programme (exercise 150 min/week at school)) and their dietary behaviours and physical activity.
Primary, middle and high schools in Taiwan.
A nationally representative sample of 2433 primary school (5th–6th grade) students, 3212 middle school students and 2829 high school students completed the online survey in 2018.
Multivariate analysis results showed that after controlling for school level, gender and age, the students’ perceptions of school sugar-free policies were negatively associated with the consumption of SSB and positively associated with consumption of plain water. Schools’ campaigns promoting the eating of vegetables and fruit were positively associated with students’ consumption of vegetables. In addition, schools’ initiatives promoting outdoor physical activity and the SH150 programme were positively associated with students’ engagement in outdoor physical activities and daily moderate-to-vigorous physical activity.
Students’ perceptions of healthy school policies and environments promote healthy eating and an increase in physical activity for students.
We aimed to investigate the associations between dietary branched-chain amino acids (BCAA) intake and long-term risks of CVD, cancer and all-cause mortality in nationwide survey participants aged ≥ 18.
This was a prospective cohort study. Dietary intakes of BCAA (leucine, isoleucine and valine) were determined from the total nutrient intake document. The main outcomes were CVD, cancer and all-cause mortality.
A nationally representative sample of US adults were recruited by the National Center for Health Statistics (NCHS) from 1988 to 1994.
A total of 14 397 adults aged ≥ 18 who participated in the United States National Health and Nutrition Examination Survey III (NHANES III) were included.
During 289 406 person-years of follow-up, we identified 4219 deaths, including 1133 from CVD and 926 from cancer. After multivariate adjustment, the hazard ratios (95 % confidence intervals) of all-cause mortality in the highest dietary BCAA and isoleucine intake quintile (reference: lowest quintiles) were 0·68 (0·48, 0·97) and 0·68 (0·48, 0·97), respectively. Each one-standard-deviation increase in total dietary BCAA or isoleucine intake was associated with an 18 % or 21 % decrease in the risk of all-cause mortality, respectively. The serum triglyceride (TAG) concentration was found to modify the association between the dietary BCAA intake and all-cause mortality (Pfor interaction = 0·008).
In a nationally representative cohort, higher dietary intakes of BCAA and isoleucine were independently associated with a lower risk of all-cause mortality, and these associations were stronger in participants with higher serum TAG concentrations.
In general, LDPC codes are classified into two categories based on their construction methods: algebraic methods and graphical methods. LDPC codes constructed based on finite geometries and finite fields are classified as algebraic LDPC codes, such as the cyclic and quasi-cyclic LDPC codes presented in to .
Cyclic codes form an important subclass of linear block codes. These codes are attractive for two reasons: first, encoding and syndrome computation can be implemented easily by using simple shift-registers with linear feedback connections, namely, linear feedback shift-registers (LFSRs); and second, because they have considerable inherent algebraic structure, it is possible to devise various practical algorithms for decoding them. Cyclic codes have been widely used in communication and storage systems for error control. They are particularly efficient for error detection.
Finite fields have been applied to construct error-correcting codes for reliable information transmission and data storage [–] since the late 1950s. These codes are commonly called algebraic codes, which have nice structures and large minimum distances. The most well-known classical algebraic codes are BCH and RS codes presented in and which can be decoded with the elegant hard-decision Berlekamp–Massey iterative algorithm.