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We derive and test a new heuristic theory for third-order structure functions that resolves the forcing scale in the scenario of simultaneous spectral energy transfer to both small and large scales, which can occur naturally, for example, in rotating stratified turbulence or magnetohydrodynamical (MHD) turbulence. The theory has three parameters – namely the upscale/downscale energy transfer rates and the forcing scale – and it includes the classic inertial-range theories as local limits. When applied to measured data, our global-in-scale theory can deduce the energy transfer rates using the full range of data, therefore it has broader applications compared with the local theories, especially in situations where the data is imperfect. In addition, because of the resolution of forcing scales, the new theory can detect the scales of energy input, which was impossible before. We test our new theory with a two-dimensional simulation of MHD turbulence.
We present an idealized study of rotating stratified wave turbulence in a two-dimensional vertical slice model of the Boussinesq equations, focusing on the peculiar case of equal Coriolis and buoyancy frequencies. In this case the fully nonlinear fluid dynamics can be shown to be isotropic in the vertical plane, which allows the classical methods of isotropic turbulence to be applied. Contrary to ordinary two-dimensional turbulence, here a robust downscale flux of total energy is observed in numerical simulations that span the full parameter regime between Ozmidov and forcing scales. Notably, this robust downscale flux of the total energy does not hold separately for its various kinetic and potential components, which can exhibit both upscale and downscale fluxes, depending on the parameter regime. Using a suitable extension of the classical Kármán–Howarth–Monin equation, exact expressions that link third-order structure functions and the spectral energy flux are derived and tested against numerical results. These expressions make obvious that even though the total energy is robustly transferred downscale, the third-order structure functions are sign indefinite, which illustrates that the sign and the form of measured third-order structure functions are both crucially important in determining the direction of the spectral energy transfer.
This research investigated patients who underwent surgery for a dilated aorta associated with a connective tissue disease or inflammatory vasculitis in children and adolescents.
Materials and Methods:
The medical records of 11 patients who underwent aortic surgery for dilatation resulting from a connective tissue disease or inflammatory vasculitis between 2000 and 2017 were retrospectively reviewed.
The median age and body weight of the patients were 9.6 years (range 5.4 months–15.5 years) and 25.8 kg (range 6.8–81.5), respectively. The associated diseases were Marfan syndrome (n = 3), Loeys-Dietz syndrome (n = 3), Kawasaki disease (n = 1), Takayasu arteritis (n = 1), PHACE syndrome (n = 1), tuberous sclerosis (n = 1), and unknown (n = 1). The most common initially affected area was the ascending aorta. During the 66.4 ± 35.9 months of follow-up, two Marfan syndrome patients died, and four patients (one Marfan syndrome and three Loeys-Dietz syndrome) had repeated aortic operation. Except for one patient, the functional class was well maintained in all patients who were followed up.
Cases of surgical treatment for a dilated aorta associated with a connective tissue disease and inflammatory vasculitis are rare in children and adolescents at our institution. Most of the patients in this study showed a tolerable postoperative course. However, the aorta showed progressive dilation over time even after surgical treatment, especially in patients with Loeys-Dietz syndrome. In these patients, close and more frequent regular follow-up is required.
Many patients with advanced serious illness or at the end of life experience delirium, a potentially reversible form of acute brain dysfunction, which may impair ability to participate in medical decision-making and to engage with their loved ones. Screening for delirium provides an opportunity to address modifiable causes. Unfortunately, delirium remains underrecognized. The main objective of this pilot was to validate the brief Confusion Assessment Method (bCAM), a two-minute delirium-screening tool, in a veteran palliative care sample.
This was a pilot prospective, observational study that included hospitalized patients evaluated by the palliative care service at a single Veterans’ Administration Medical Center. The bCAM was compared against the reference standard, the Diagnostic and Statistical Manual of Mental Disorders, fifth edition. Both assessments were blinded and conducted within 30 minutes of each other.
We enrolled 36 patients who were a median of 67 years (interquartile range 63–73). The primary reasons for admission to the hospital were sepsis or severe infection (33%), severe cardiac disease (including heart failure, cardiogenic shock, and myocardial infarction) (17%), or gastrointestinal/liver disease (17%). The bCAM performed well against the Diagnostic and Statistical Manual of Mental Disorders, fifth edition, for detecting delirium, with a sensitivity (95% confidence interval) of 0.80 (0.4, 0.96) and specificity of 0.87 (0.67, 0.96).
Significance of Results
Delirium was present in 27% of patients enrolled and never recognized by the palliative care service in routine clinical care. The bCAM provided good sensitivity and specificity in a pilot of palliative care patients, providing a method for nonpsychiatrically trained personnel to detect delirium.
The status of Asian populations of the Eurasian otter Lutra lutra is largely unknown. Since its designation as a Natural Monument (in 1983) and as Endangered (in 1997) in South Korea the authorities there have been trying to conserve and recover the species. We conducted a national otter survey by standard methods in 2017 and compared the current otter distribution to those recorded in a previous survey (2010). We found otter signs in 84.5% of 1,105 10 × 10 km grid cells, with the highest sprainting intensity in the south-west in the Yeongsan River Basin and on the south coast, where we recorded 7.05 and 6.26 spraints/site, respectively. Despite relatively low spraint densities, the otter has expanded its range since 2010 by colonizing urban areas. This trend suggests that South Korea could be a source area for the recovery of the Eurasian otter in East Asia.
Large-scale coherent structures such as jets in Rayleigh–Bénard convection and related systems are receiving increasing attention. This paper studies, both numerically and theoretically, the process of jet formation in two-dimensional salt-finger convection. The approach utilizes an asymptotically derived system of equations referred to as the modified Rayleigh–Bénard convection (MRBC) model, valid in the geophysically and astrophysically relevant limit in which the solute diffuses much more slowly than heat. In these equations, convection is driven by a destabilizing salinity gradient while the effects of the stabilizing temperature gradient manifest themselves as an additional anisotropic dissipation acting on large scales. The MRBC system is specified by two external parameters: the Schmidt number
(ratio of viscosity to solutal diffusivity) and the Rayleigh ratio
(ratio between the Rayleigh numbers of the destabilizing solutal stratification and the stabilizing thermal stratification). Two distinct
regimes are explored for fixed
. In all cases studied the system develops a horizontal jet structure that is maintained self-consistently by turbulent fluctuations, but coarsens over time. For intermediate Rayleigh ratios (e.g.
), the MRBC model captures the relaxation oscillations superposed on the jet structure observed at similar parameter values in direct numerical simulations of the primitive equations. For smaller Rayleigh ratios (e.g.
), a regime for which direct numerical simulation of the primitive equations is difficult because of the presence of fast gravity waves, the MRBC model reveals the existence of statistically steady jets whose properties are studied in detail. Three hierarchical models, the MRBC and further reductions in the form of quasilinear and single-mode approximations, are used to confirm that jets form and are sustained as a result of the interaction between fluctuations (salt fingers) and large-scale horizontally averaged horizontal flows (jets). Even though the small-scale structures exhibited by the three models exhibit clear differences, all three produce the same power-law spectrum of the mean fields at large vertical scales: in all, the spectrum of the mean streamfunction scales as
and the mean salinity field scales as
the vertical wavenumber. A theoretical explanation of these observations based on the dominant balances in the mean and fluctuation equations is provided. As a consequence, the jets have a zigzag profile, a conclusion that is consistent with numerical simulations. Based on numerical observations, a three-component phenomenological model consisting of a linearly growing mode, a linearly damped mode and a mean mode is proposed to explain the observed transition from statistically steady jet structure to jets with superposed oscillations that takes place with increasing Rayleigh ratio.
Several epidemiological studies have investigated that Na or K intakes might be associated with the metabolic syndrome (MetS). However, little evidence has evaluated the association between Na:K ratio and the MetS. In this study, we assessed the association between the dietary Na:K ratio and the MetS. The cross-sectional study was conducted among adults aged 18 years and older in Nanjing, using a multi-stage random sampling method, which resulted in a sample size of 1993 participants. Dietary Na and K intakes were assessed by 3 consecutive days of dietary recollection combined with condiments weighing method. Health-related data were obtained by standardised questionnaires, as well as physical examinations and laboratory assessments. The prevalence rate of the MetS was 36·5 % (728/1993). After adjusting for various lifestyle and dietary factors of the MetS, participants in the highest quartile of dietary Na:K ratio were at a higher risk of developing MetS (OR=1·602; 95 % CI 1·090, 2·353) compared with those in the lowest quartile. Each 1-sd increase in dietary Na:K ratio was associated with a higher risk of prevalent MetS (OR=1·166; 95 % CI: 1·018, 1·336). Among the components of the MetS, dietary Na:K ratio was positively associated with high blood pressure (quartile 3 v. quartile 1: OR=1·656; 95 % CI 1·228, 2·256) and hypertriacylglycerolaemia (quartile 4 v. quartile1: OR=1·305; 95 % CI 1·029, 1·655) in multivariate analysis. These results revealed that higher dietary Na:K ratio significantly increased the risk of the MetS in Chinese adults. Further studies are needed to verify this association.
We derive and investigate exact expressions for third-order structure functions in stationary isotropic two-dimensional turbulence, assuming a statistical balance between random forcing and dissipation both at small and large scales. Our results extend previously derived asymptotic expressions in the enstrophy and energy inertial ranges by providing uniformly valid expressions that apply across the entire non-dissipative range, which, importantly, includes the forcing scales. In the special case of white noise in time forcing this leads to explicit predictions for the third-order structure functions, which are successfully tested against previously published high-resolution numerical simulations. We also consider spectral energy transfer rates and suggest and test a simple robust diagnostic formula that is useful when forcing is applied at more than one scale.
Delirium is heterogeneous and can vary by etiology.
We sought to determine how delirium subtyped by etiology affected six-month function and cognition.
Prospective cohort study.
Tertiary care, academic medical center.
A total of 228 hospitalized patients > 65 years old were admitted from the emergency department (ED).
The modified Brief Confusion Assessment Method was used to determine delirium in the ED. Delirium etiology was determined by three trained physician reviewers using a Delirium Etiology checklist. Pre-illness and six-month function and cognition were determined using the Older American Resources and Services Activities of Daily Living (OARS ADL) questionnaire and the short-form Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE). Multiple linear regression was performed to determine if delirium etiology subtypes were associated with six-month function and cognition adjusted for baseline OARS ADL and IQCODE. Two-factor interactions were incorporated to determine pre-illness function or cognition-modified relationships between delirium subtypes and six-month function and cognition.
In patients with poorer pre-illness function only, delirium secondary to metabolic disturbance (β coefficient = −2.9 points, 95%CI: −0.3 to −5.6) and organ dysfunction (β coefficient = −4.3 points, 95%CI: −7.2 to −1.4) was significantly associated with poorer six-month function. In patients with intact cognition only, delirium secondary to central nervous system insults was significantly associated with poorer cognition (β coefficient = 0.69, 95%CI: 0.19 to 1.20).
Delirium is heterogeneous and different etiologies may have different prognostic implications. Furthermore, the effect of these delirium etiologies on outcome may be dependent on the patient's pre-illness functional status and cognition.
The aim of this study was to determine whether vitamin D supplementation and maintaining vitamin D sufficiency are associated with changes in inflammatory and metabolic biomarkers in patients with knee osteoarthritis (OA) and vitamin D deficiency. A total of 413 participants with symptomatic knee OA and vitamin D deficiency were enrolled in a randomised, placebo-controlled trial and received 1·25 mg vitamin D3 or placebo monthly for 24 months across two sites. In this post hoc analysis, 200 participants from one site (ninety-four from the placebo group and 106 from the vitamin D group; mean age 63·1 (sd 7·3) years, 53·3 % women) were randomly selected for measurement of serum levels of inflammatory and metabolic biomarkers at baseline and 24 months using immunoassays. In addition, participants were classified into two groups according to serum 25-hydroxyvitamin D (25(OH)D) levels at months 3 and 24: (1) not consistently sufficient (25(OH)D≤50 nmol/l at either month 3 or 24, n 61), and (2) consistently sufficient (25(OH)D>50 nmol/l at both months 3 and 24, n 139). Compared with placebo, vitamin D supplementation had no significant effect on change in serum high-sensitive C-reactive protein, IL-6, IL-8, IL-10, leptin, adiponectin, resistin, adipsin and apelin. Being consistently vitamin D sufficient over 2 years was also not associated with changes in these biomarkers compared with not being consistently sufficient. Vitamin D supplementation and maintaining vitamin D sufficiency did not alter serum levels of inflammatory and metabolic biomarkers over 2 years in knee OA patients who were vitamin D insufficient, suggesting that they may not affect systemic inflammation in knee OA patients.
We describe the case of a young man with bilateral coronary artery to left ventricular fistula, which was drained via a single, common channel. The anomaly was incidentally detected with coronary CT angiography.
Mountain-generated inertia–gravity waves (IGWs) affect the dynamics of both the atmosphere and the ocean through the mean force they exert as they interact with the flow. A key to this interaction is the presence of critical-level singularities or, when planetary rotation is taken into account, inertial-level singularities, where the Doppler-shifted wave frequency matches the local Coriolis frequency. We examine the role of the latter singularities by studying the steady wavepacket generated by a multiscale mountain in a rotating linear shear flow at low Rossby number. Using a combination of Wentzel–Kramers–Brillouin (WKB) and saddle-point approximations, we provide an explicit description of the form of the wavepacket, of the mean forcing it induces and of the mean-flow response. We identify two distinguished regimes of wave propagation: Regime I applies far enough from a dominant inertial level for the standard ray-tracing approximation to be valid; Regime II applies to a thin region where the wavepacket structure is controlled by the inertial-level singularities. The wave–mean-flow interaction is governed by the change in Eliassen–Palm (or pseudomomentum) flux. This change is localised in a thin inertial layer where the wavepacket takes a limiting form of that found in Regime II. We solve a quasi-geostrophic potential-vorticity equation forced by the divergence of the Eliassen–Palm flux to compute the wave-induced mean flow. Our results, obtained in an inviscid limit, show that the wavepacket reaches a large-but-finite distance downstream of the mountain (specifically, a distance of order
measure the wave and envelope scales of the mountain) and extends horizontally over a similar scale.
The Saemangeum tidal flat, an important staging site for migratory shorebirds that travel the East Asian-Australasian (EAA) Flyway, was isolated from the eastern Yellow Sea in 2006 as part of a large-scale reclamation project. To gain a better understanding of the impacts that this reclamation has had on the long-distance migratory shorebirds that use the EAA Flyway, we examined the number of shorebirds visiting Saemangeum and three adjacent sites in the Geum Estuary (Yubu Island, the Janghang coastline, and the Geum River Channel) during the spring and fall prior to, and after, completion of the reclamation (2004–2013). A total of 48 shorebird species, including one Critically Endangered, three Endangered, and nine Near Threatened species, were observed over this period. Peak numbers of shorebirds recorded at sites in Saemangeum and the Geum Estuary following completion of the project were 74% below those recorded in 2004 and 2005, the years prior to reclamation activity. In Saemangeum, shorebird abundance declined by approximately 95% and 97.3% during the northward and southward migrations, respectively, as a result of reclamation. Although shorebird populations in the Geum Estuary increased by 5% and 20% during the northwards and southward migrations, respectively, these increases failed to offset the reduction in shorebird abundance in Saemangeum; overall, shorebird abundance at Saemangeum and the three adjacent sites in the Geum Estuary markedly declined over the reclamation period. Given the more favourable conditions of adjacent areas, sites in Saemangeum and the Geum Estuary no longer provide the habitat conditions necessary for long-distance migratory shorebirds. In order to improve habitat for staging migratory birds, we suggest that measures such as the conversion of an abandoned salt farm for use as roosting sites, the construction of artificial barriers to prevent human disturbance, and re-opening of the river-banks to facilitate water flow be implemented.
A series of oxidation experiments were carried out on these novel γ/γ′-strengthened cobalt-based alloys of the systems Co–9Al–10W and Co–9Al–10W–0.02X (X = La, Ce, Dy, Y) at 900 °C. The appropriate amounts’ addition of rare earth elements leads to improved oxidation properties at 900 °C, especially La elements show the best oxidation resistance (129.008 mg/cm2). However, the base Co–9Al–10W alloy shows the worst oxidation performance (151.544 mg/cm2). Multilayer oxide layers formed during the oxidation process, the outer were mainly CoO and Co3O4 oxides, and the middle layer contained complex oxides (containing Co, Al, and W). The inner layer consists of little discontinuous oxides, included few Al2O3 oxides. There existed a different crack width and the base alloy had the widest crack. Moreover, there exists a phase transformation (γ/γ′ to γ/Co3W) at the interface between oxide film and substrate.
In this paper, we proposed a simple approach to analyse the efficiency and propulsive characteristics of the high-altitude propeller in accordance to the Vortex Lattice Lifting line Method (VLM) theory, which is commonly used in preliminary design and parametric studies of propeller propulsion. The Computational Fluid Dynamics (CFD) method was used to obtain aerofoil aerodynamic data. The optimal pitch angle and propeller blade chord length (along the radial direction) can be calculated using the information from the database. The propeller wake model sees helical slipstreams applied to both lightly and moderately loaded propellers. The proposed method is capable of identifying the optimal efficiency through varying the number of propeller blades, radius and the rotational speed. The relationship between the optimal efficiency and design parameters is then established. This method was verified using CFD calculations.
A life-threatening cardiopulmonary resuscitation (CPR)-related injury can cause recurrent arrest after return of circulation. Such injuries are difficult to identify during resuscitation, and their contribution to failed resuscitation can be missed given the limitations of conventional CPR. Extracorporeal cardiopulmonary resuscitation (ECPR), increasingly being considered for selected patients with potentially reversible etiology of arrest, may identify previously occult CPR-related injuries by restoring arterial pressure and flow. Herein, we describe two cases of severe CPR-related injuries contributing to recurrent arrest. Each case had ECPR implemented within 60 minutes of the start of CPR. After the presumed cardiac etiology had been addressed with percutaneous coronary intervention, life-threatening cardiovascular injuries with recurrent arrest were noted, and resuscitative thoracotomy was performed under ECPR. One patient survived to hospital discharge.
ECPR may provide an opportunity to identify and correct severe resuscitation-related injuries causing recurrent arrest. Chest compression depth >6 cm, especially in older women, may contribute to these injuries.
Personality may predispose family caregivers to experience caregiving differently in similar situations and influence the outcomes of caregiving. A limited body of research has examined the role of some personality traits for health-related quality of life (HRQoL) among family caregivers of persons with dementia (PWD) in relation to burden and depression.
Data from a large clinic-based national study in South Korea, the Caregivers of Alzheimer's Disease Research (CARE), were analyzed (N = 476). Path analysis was performed to explore the association between family caregivers’ personality traits and HRQoL. With depression and burden as mediating factors, direct and indirect associations between five personality traits and HRQoL of family caregivers were examined.
Results demonstrated the mediating role of caregiver burden and depression in linking two personality traits (neuroticism and extraversion) and HRQoL. Neuroticism and extraversion directly and indirectly influenced the mental HRQoL of caregivers. Neuroticism and extraversion only indirectly influenced their physical HRQoL. Neuroticism increased the caregiver's depression, whereas extraversion decreased it. Neuroticism only was mediated by burden to influence depression and mental and physical HRQoL.
Personality traits can influence caregiving outcomes and be viewed as an individual resource of the caregiver. A family caregiver's personality characteristics need to be assessed for tailoring support programs to get the optimal benefits from caregiver interventions.