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An ultrasonic phased array system is introduced to study the three-dimensional (3-D) movement of a single bubble in a GaInSn alloy under a transverse magnetic field (MF), which is verified by bubble experiments in water. The 3-D motion trajectories of individual bubbles in the GaInSn are obtained under a horizontal MF. As the MF becomes stronger, the bubble successively oscillates in random directions (R mode), a direction perpendicular to the MF (V mode), a direction parallel to the MF (P mode) and finally it rises straight (S mode). The significant anisotropy of the oscillation directions at a moderate MF intensity may be due to the anisotropy of the vortex structure around the bubble. Furthermore, the oscillation amplitude gradually declines with increasing MF intensity until the bubble trajectory finally becomes a straight line. Our measurements allow us to specify the characteristic regions for the observed bubble modes in the $N-Eo-Re$ parameter space (N is the magnetic interaction parameter, Eo is the Eötvös number and Re is the Reynolds number). In addition, more detailed characteristics of bubble terminal velocity are revealed, showing that the bubble velocities are closely related to the motion modes. The increase in bubble velocity at a moderate MF intensity is caused by the weakening oscillation. At a high strength, the MF monotonically suppresses the rise velocity of the bubble with a fixed scaling law.
Amid resurgent geopolitical fissures and in the aftermath of the Covid-19 pandemic, there is a growing awareness in the sector of the need for, and concern about, national and international collaboration in archaeological projects. This article reflects on present-day challenges for international collaboration in central Eurasian archaeology and furthers a much-needed discussion about (re)integrating local narratives with inter-regional trends in future research. Responsible and practical proposals for bridging collaborator differences in institutional or publishing obligations, language capacities and access to resources are discussed.
Essential minerals are cofactors for synthesis of neurotransmitters supporting cognition and mood. An 8-week fully-blind randomised controlled trial of multinutrients for attention-deficit/hyperactivity disorder (ADHD) demonstrated three times as many children (age 6–12) had significantly improved behaviour (‘treatment responders’) on multinutrients (54 %) compared with placebo (18 %). The aim of this secondary study was to evaluate changes in fasted plasma and urinary mineral concentrations following the intervention and their role as mediators and moderators of treatment response. Fourteen essential or trace minerals were measured in plasma and/or urine at baseline and week eight from eighty-six participants (forty-nine multinutrients, thirty-seven placebos). Two-sample t tests/Mann–Whitney U tests compared 8-week change between treatment and placebo groups, which were also evaluated as potential mediators. Baseline levels were evaluated as potential moderators, using logistic regression models with clinical treatment response as the outcome. After 8 weeks, plasma boron, Cr (in females only), Li, Mo, Se and vanadium and urinary iodine, Li and Se increased more with multinutrients than placebo, while plasma phosphorus decreased. These changes did not mediate treatment response. However, baseline urinary Li trended towards moderation: participants with lower baseline urinary Li were more likely to respond to multinutrients (P = 0·058). Additionally, participants with higher baseline Fe were more likely to be treatment responders regardless of the treatment group (P = 0·036.) These results show that multinutrient treatment response among children with ADHD is independent of their baseline plasma mineral levels, while baseline urinary Li levels show potential as a non-invasive biomarker of treatment response requiring further study.
This article approaches the Metapolitefsi as an international event and seeks to historicize the perceptions and concepts that drove Greek and Western policy-making after the fall of the junta. Its main argument is that from 1974 to 1976 and in conjunction with domestic democratization, a parallel process developed when it came to Greece's external relations, which entailed a significant reformulation of Greek foreign policy. The year 1974, then, should be seen as an important turning point not only in Greek domestic politics but in Greece's external relations as well. These two processes were mutually reinforcing and closely interdependent.
Econometricians have usefully separated study of estimation into identification and statistical components. Identification analysis, which assumes knowledge of the probability distribution generating observable data, places an upper bound on what may be learned about population parameters of interest with finite-sample data. Yet Wald’s statistical decision theory studies decision-making with sample data without reference to identification, indeed without reference to estimation. This paper asks if identification analysis is useful to statistical decision theory. The answer is positive, as it can yield an informative and tractable upper bound on the achievable finite-sample performance of decision criteria. The reasoning is simple when the decision-relevant parameter (true state of nature) is point-identified. It is more delicate when the true state is partially identified and a decision must be made under ambiguity. Then the performance of some criteria, such as minimax regret, is enhanced by randomizing choice of an action in a controlled manner. I find it useful to recast choice of a statistical decision function as selection of choice probabilities for the elements of the choice set.
The potential threshold for dietary energy intake (DEI) that might prevent protein-energy wasting (PEW) in chronic kidney disease (CKD) is uncertain. The subjects were non-dialysis CKD patients aged ≥ 14 years who were hospitalised from September 2019 to July 2022. PEW was measured by subjective global assessment. DEI and dietary protein intake (DPI) were obtained by 3-d diet recalls. Patients were divided into adequate DEI group and inadequate DEI group according to DEI ≥ 30 or < 30 kcal/kg/d. Logistic regression analysis and restricted cubic spline were used in this study. We enrolled 409 patients, with 53·8 % had hypertension and 18·6 % had diabetes. The DEI and DPI were 27·63 (sd 5·79) kcal/kg/d and 1·00 (0·90, 1·20) g/kg/d, respectively. 69·2 % of participants are in the inadequate DEI group. Malnutrition occurred in 18·6 % of patients. Comparing with patients in the adequate DEI group, those in the inadequate DEI group had significantly lower total lymphocyte count, serum cholesterol and LDL-cholesterol and a higher prevalence of PEW. For every 1 kcal/kg/d increase in DEI, the incidence of PEW was reduced by 12·0 % (OR: 0·880, 95 % CI: 0·830, 0·933, P < 0·001). There was a nonlinear curve relationship between DEI and PEW (overall P < 0·001), and DEI ≥ 27·6 kcal/kg/d may have a preventive effect on PEW in CKD. Low DPI was also significantly associated with malnutrition, but not when DEI was adequate. Decreased energy intake may be a more important factor of PEW in CKD than protein intake.
To examine if the COVID-19 pandemic was associated with a differential effect longitudinally in relation to its psychological and functional impact on patients with bipolar disorder and Emotionally Unstable Personality Disorder (EUPD).
Methods:
Semi-structured interviews were conducted with 29 individuals attending the Galway-Roscommon Mental Health Services with an ICD-10 diagnosis of either bipolar disorder (n = 18) or EUPD (n = 11). The impact of the COVID-19 pandemic was assessed in relation to anxiety and mood symptoms, social and occupational functioning, and quality of life utilising psychometric instruments and Likert scale data, with qualitative data assessing participants’ subjective experiences.
Results:
Individuals with EUPD exhibited significant anxiety and depressive symptoms and increased hopelessness compared to individuals with bipolar disorder. Repeated measures data demonstrated no significant change in symptomatology for either the EUPD or bipolar disorder group over time, but demonstrated an improvement in social (t = 4.40, p < 0.001) and occupational functioning (t = 3.65, p = 0.03), and in quality of life (t = 4.03, p < 0.001) for both participant groups. Themes attained from qualitative data included the positive impact of the discontinuation of COVID-19 mandated restrictions (n = 19), and difficulties experienced secondary to reductions in the provision of mental health services during the COVID-19 pandemic (n = 17).
Conclusion:
Individuals with EUPD demonstrated increased symptomatology over a two-year period compared to those with bipolar disorder. The importance of face-to-face mental health supports for this cohort are indicated, particularly if future pandemics impact the delivery of mental health services.
This paper proposes and partially defends a novel philosophy of arithmetic—finitary upper logicism. According to it, the natural numbers are finite cardinalities—conceived of as properties of properties—and arithmetic is nothing but higher-order modal logic. Finitary upper logicism is furthermore essentially committed to the logicality of finitary plenitude, the principle according to which every finite cardinality could have been instantiated. Among other things, it is proved in the paper that second-order Peano arithmetic is interpretable, on the basis of the finite cardinalities’ conception of the natural numbers, in a weak modal type theory consisting of the modal logic $\mathsf {K}$, negative free quantified logic, a contingentist-friendly comprehension principle, and finitary plenitude. By replacing finitary plenitude for the axiom of infinity this result constitutes a significant improvement on Russell and Whitehead’s interpretation of second-order Peano arithmetic, itself based on the finite cardinalities’ conception of the natural numbers.
Classical political economists developed several different explanations for what they saw as an inherent tendency for the rate of profit to decline over time. In the second quarter of the nineteenth century, some British advocates of colonization developed a corollary to those theories, suggesting that exporting capital to colonies could help arrest and reverse the decline. That argument was championed by the English political economist and promoter of colonization projects Edward Gibbon Wakefield, and it was systematized by John Stuart Mill. Ironically, the view that capital export and colonization played crucial roles in sustaining the rate of profit in advanced economies was later adopted by some Marxist theorists. Parallels between Karl Marx and J. S. Mill may help explain the remarkable theoretical continuity on this topic between nineteenth-century British advocates of colonization and early twentieth-century Marxist critics of colonialism.
Few previous studies have investigated how socioeconomic differences in labour market exit have changed after restrictions in social insurance policies. The aim of this register-based study is to investigate how early labour market exit pathways among older men and women with different levels of education changed after major restrictive social insurance and retirement policy reforms in Sweden. Cohort 1 (pre-reform) consisted of individuals who were 60 or 61 years old in 2005 (N = 186,145) and Cohort 2 (post-reform) consisted of individuals who were 60 or 61 years old in 2012 (N = 176,216). Educational differences in four labour market exit pathways were investigated using Cox proportional hazards regression; the exit pathways were disability pension, early old-age pension with and without income respectively, and no income for two consecutive years. As expected, exits through disability pension were rarer in Cohort 2. Lower education was also more strongly associated with disability pension in Cohort 2. Parallel to this, lower education showed a stronger association with both early old-age pension types in Cohort 2. Additionally, a tendency towards a relatively higher likelihood of earning no income was seen among the less educated. Increases in inequalities tended to be greater for women. Our results indicate that educational inequalities in labour market exit have grown significantly after restrictions in social insurance and changes in retirement policies, which can have negative financial repercussions for those already in a vulnerable position. These results indicate that careful analyses of effects on disparities are needed before making major changes in welfare systems.
This paper extends the spurious factor analysis of Onatski and Wang (2021, Spurious factor analysis. Econometrica, 89(2), 591–614.) to high-dimensional data with heterogeneous local-to-unit roots. We find a spurious factor phenomenon similar to that observed in the data with unit roots. Namely, the “factors” estimated by the principal components analysis converge to principal eigenfunctions of a weighted average of the covariance kernels of the demeaned Ornstein–Uhlenbeck processes with different decay rates. Thus, such “factors” reflect the structure of the strong temporal correlation of the data and do not correspond to any cross-sectional commonalities, that genuine factors are usually associated with. Furthermore, the principal eigenvalues of the sample covariance matrix are very large relative to the other eigenvalues, creating an illusion of the “factors”capturing much of the data’s common variation. We conjecture that the spurious factor phenomenon holds, more generally, for data obtained from high frequency sampling of heterogeneous continuous time (or spacial) processes, and provide an illustration.
To evaluate the clinical impact and features associated with repeat tracheal aspirate (TA) cultures in children admitted to the intensive care unit.
Design:
Retrospective cohort study.
Setting:
A 338-bed freestanding, tertiary pediatric academic medical center with pediatric medical intensive care unit (PICU) and cardiac intensive care units (CICU).
Patients:
Children ≤18 years of age who were admitted to either the PICU or CICU who had ≥2 TA cultures in a single intensive care admission.
Methods:
Patients with ≥2 TA cultures between 2018 and 2019 were included in this study. The following information was collected: patient demographics, clinical data summarizing patient condition at the time of culture collection, number of TA cultures per patient, antibiotic usage, and microbiologic data. Descriptive statistics established the frequency of TA collection, time between culturing, clinical reasoning for collection, antibiotic exposure, and development of multidrug-resistant organisms (MDRO).
Results:
Sixty-three patients had repeat TA cultures and accounted for 252 TA cultures during the study period. Most patients with repeat TA cultures were admitted to the PICU (71%) and were male (65%). A median of 3 TA cultures per patient were obtained with 50% of repeat cultures occurring within 7 days from the previous culture. Sixty-six percent of patients had the same organism cultured on ≥2 TA cultures. Most antibiotics were not modified or continued to treat the results of the TA culture.
Conclusions:
Repeat TA cultures frequently show the same pathogens, and results do not often influence antibiotic selection or usage. Repeat TA cultures did demonstrate the development of MDROs.
We consider two-dimensional flows above topography, revisiting the selective decay (or minimum enstrophy) hypothesis of Bretherton and Haidvogel. We derive a ‘condensed branch’ of solutions to the variational problem where a domain-scale condensate coexists with a flow at the (smaller) scale of the topography. The condensate arises through a supercritical bifurcation as the conserved energy of the initial condition exceeds a threshold value, a prediction that we quantitatively validate using direct numerical simulations. We then consider the forced–dissipative case, showing how weak forcing and dissipation select a single dissipative state out of the continuum of solutions to the energy-conserving system predicted by selective decay. As the forcing strength increases, the condensate arises through a supercritical bifurcation for topographic-scale forcing and through a subcritical bifurcation for domain-scale forcing, both predictions being quantitatively validated by direct numerical simulations. This method provides a way of determining the equilibrated state of forced–dissipative flows based on variational approaches to the associated energy-conserving system, such as the statistical mechanics of two-dimensional flows or selective decay.
Although the roll-streak (R-S) is fundamentally involved in the dynamics of wall turbulence, the physical mechanism responsible for its formation and maintenance remains controversial. In this work we investigate the dynamics maintaining the R-S in turbulent Poiseuille flow at $R=1650$. Spanwise collocation is used to remove spanwise displacement of the streaks and associated flow components, which isolates the streamwise-mean flow R-S component and the second-order statistics of the streamwise-varying fluctuations that are collocated with the R-S. This partition of the dynamics into streamwise-mean and fluctuation components facilitates exploiting insights gained from the analytic characterization of turbulence in the second-order statistical state dynamics (SSD), referred to as S3T, and its closely associated restricted nonlinear dynamics (RNL) approximation. Symmetry of the statistics about the streak centreline permits separation of the fluctuations into sinuous and varicose components. The Reynolds stress forcing induced by the sinuous and varicose fluctuations acting on the R-S is shown to reinforce low- and high-speed streaks, respectively. This targeted reinforcement of streaks by the Reynolds stresses occurs continuously as the fluctuation field is strained by the streamwise-mean streak and not intermittently as would be associated with streak-breakdown events. The Reynolds stresses maintaining the streamwise-mean roll arise primarily from the dominant proper orthogonal decomposition (POD) modes of the fluctuations, which can be identified with the time average structure of optimal perturbations growing on the streak. These results are consistent with a universal process of R-S growth and maintenance in turbulent shear flow arising from roll forcing generated by straining turbulent fluctuations, which was identified using the S3T SSD.
We report the presence of three Palaearctic species, Suillia variegata (Loew), Tephrochlamys flavipes (Zetterstedt), and Tephrochlamys tarsalis (Zetterstedt) (Diptera: Heleomyzidae), recently introduced to North America. We use community science (also known as citizen science) data to show that S. variegata, which was first reported in Portland, Oregon, United States of America, in 2016, has persisted in that area and has subsequently also been observed in Washington and California. Tephrochlamys flavipes, first reported in Seattle, Washington, United States of America, in 2010, has been observed comparatively more rarely, in a more restricted geographic area. The presence of T. tarsalis in the Nearctic, previously reported in Canada based on genetic barcodes, is verified from photographs taken in British Columbia, Canada and Washington. We provide updates to the keys to Suillia Robineau-Desvoidy and Tephrochlamys Loew of the United States of America and Canada. Finally, we discuss potential means of introduction and patterns of dispersal for each species.
International migrants face barriers when accessing health-care in their destination countries. For older migrants, there are additional difficulties due to their age and associated health conditions. Chinese migrants are an understudied group with culture-specific barriers in addition to those shared with other migrant groups. This review aims to understand the barriers and facilitators to health-care access faced by older Chinese migrants in high-income countries. Literature from MEDLINE, Web of Science, EMBASE, Scopus, CINAHL Plus and ProQuest (1 January 2000 to 6 October 2021) were retrieved. Quantitative, qualitative and mixed-methods studies focusing on older Chinese migrants’ access to, utilisation of and satisfaction with health-care services in high-income countries were included. Studies were appraised using checklists from the Joanna Briggs Institute and the Critical Appraisal Skills Programme. Qualitative and quantitative data were extracted and analysed narratively to identify barriers and facilitators to accessing health-care, then applied to Levesque’s five-step health-care access journey framework. We included 33 studies in the analysis. Qualitative evidence identified barriers and facilitators to health-care access in four categories: health-care system, social factors, personal factors and health-care interactions. Quantitative studies found that health status and having insurance were positively associated with using non-preventive care, while time of residence and physician’s recommendations were positively associated with using preventive care. Factors that influence older Chinese migrants’ access to health care include practical barriers (communication, time and cost), social support (family and community), perceptions of health and care needs (beliefs and knowledge) and interactions with health-care professionals (patient–physician trust and support from physicians). Efforts to overcome universal barriers, acknowledgement of cultural contexts, improvements in translation services, and involvement of Chinese families and communities in health-care outreach will benefit this population.
Pressure-driven flows of viscoelastic fluids in narrow non-uniform geometries are common in physiological flows and various industrial applications. For such flows, one of the main interests is understanding the relationship between the flow rate $q$ and the pressure drop $\Delta p$, which, to date, is studied primarily using numerical simulations. We analyse the flow of the Oldroyd-B fluid in slowly varying arbitrarily shaped, contracting channels and present a theoretical framework for calculating the $q-\Delta p$ relation. We apply lubrication theory and consider the ultra-dilute limit, in which the velocity profile remains parabolic and Newtonian, resulting in a one-way coupling between the velocity and polymer conformation tensor. This one-way coupling enables us to derive closed-form expressions for the conformation tensor and the flow rate–pressure drop relation for arbitrary values of the Deborah number ($De$). Furthermore, we provide analytical expressions for the conformation tensor and the $q-\Delta p$ relation in the high-Deborah-number limit, complementing our previous low-Deborah-number lubrication analysis. We reveal that the pressure drop in the contraction monotonically decreases with $De$, having linear scaling at high Deborah numbers, and identify the physical mechanisms governing the pressure drop reduction. We further elucidate the spatial relaxation of elastic stresses and pressure gradient in the exit channel following the contraction and show that the downstream distance required for such relaxation scales linearly with $De$.