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The linear temporal and absolute/convective stability characteristics of a thermal plume generated along a heated vertical cylinder are investigated theoretically under the Boussinesq approximation. Special focus is given to the uniform-wall-buoyancy-flux case whereby the cylinder surface sustains the same linear temperature gradient as the environment. A competition between the axisymmetric and helical modes is a remarkable feature of the instability, distinguishing these ‘annular plumes’ from free plumes/jets for which the helical mode is generally dominant. It is found that higher surface curvature stabilises the temporal axisymmetric mode significantly, but only has moderate effects on the helical mode. The most temporally unstable perturbation mode switches from a helical into an axisymmetric mode when the Prandtl number increases beyond a critical value. Both the roles of shear and buoyancy during the destabilisation are identified through an energy analysis which indicates that, while the shear work is usually a major source of perturbation energy, the buoyancy work manifests for long-wave axisymmetric perturbation modes, and for thin cylinders and high Prandtl numbers. For the specific temperature configuration considered herein, an annular plume is always convectively unstable whereas decreasing the cylinder radius from the planar limiting case first decreases and then increases the tendency of the flow towards being absolutely unstable. The helical mode is especially susceptible to being absolutely unstable on very thin cylinders. Several conditions for the onset of cellular thermal convection and plume detrainment are proposed based on our results and a hypothesis which connects the absolute instability to the detrainment phenomenon.
ABSTRACT IMPACT: This study deepens knowledge with respect to the associations between depression, cardiometabolic conditions, and accelerated aging with a clinically accessible marker in a population with disproportionate risk for comorbidity. OBJECTIVES/GOALS: The aim of this secondary analysis is to examine associations between DNA methylation age acceleration (DNAm AA) and depressive symptoms in African American women (AAW) considering the presence of cardiometabolic conditions (CMCs) including hypertension, diabetes, obesity. METHODS/STUDY POPULATION: Genomic and longitudinal clinical data (collected 2015-2020) from the Intergenerational Impact of Genetic and Psychosocial Factors on Blood Pressure Study (InterGEN) cohort (n=227) were utilized for this analysis. DNA methylation age (estimated by the Horvath method) incorporates DNA methylation status at 353 CpG sites. DNAm AA is the residual of DNA methylation age regressed on chronological age in a linear model. Spearman’s correlations and linear regression examine the relationship between DNAm AA and depressive symptoms (Beck Depression Inventory) and cardiometabolic status. The potential association and impact of SES, trauma, substance use, and stress were also considered. RESULTS/ANTICIPATED RESULTS: Contrary to our hypothesis, DNAm AA did not associate with the severity of depressive symptoms. Correlation between DNAm AA and affective symptom subscore (BDI) approached significance (p = 0.06). We observed significant correlations between DNAm AA and specific depressive symptoms including participants’ reported disappointment, disgust, or hatred toward themselves (p < 0.05), difficulty with making decisions (p < 0.05), and worry about their physical health (p < 0.05). DNAm AA was also significantly correlated with BMI (p > 0.001). Significant relationships were not evident in the subsequent regression analysis examining potential relationships between DNAm AA and depression. To our knowledge, this is the first study to examine associations between DNAm AA and depressive symptoms in AAW. DISCUSSION/SIGNIFICANCE OF FINDINGS: Depression limits life quality and quantity and is highly comorbid in CMCs. AAW have a high risk of comorbidity. This study deepens knowledge with respect to the associations between depression, CMCs, and aging with a clinically accessible marker in a population with disproportionate risk.
Social cognition has not previously been assessed in treatment-naive patients with chronic schizophrenia, in patients over 60 years of age, or in patients with less than 5 years of schooling.
We revised a commonly used measure of social cognition, the Reading the Mind in the Eyes Test (RMET), by expanding the instructions, using both self-completion and interviewer-completion versions (for illiterate respondents), and classifying each test administration as ‘successfully completed’ or ‘incomplete’. The revised instrument (RMET-CV-R) was administered to 233 treatment-naive patients with chronic schizophrenia (UT), 154 treated controls with chronic schizophrenia (TC), and 259 healthy controls (HC) from rural communities in China.
In bivariate and multivariate analyses, successful completion rates and RMET-CV-R scores (percent correct judgments about emotion exhibited in 70 presented slides) were highest in HC, intermediate in TC, and lowest in UT (adjusted completion rates, 97.0, 72.4, and 49.9%, respectively; adjusted RMET-CV-R scores, 45.4, 38.5, and 34.6%, respectively; all p < 0.02). Stratified analyses by the method of administration (self-completed v. interviewer-completed) and by education and age (‘educated-younger’ v. ‘undereducated-older’) show the same relationship between groups (i.e. NC>TC>UT), though not all differences remain statistically significant.
We find poorer social cognition in treatment-naive than in treated patients with chronic schizophrenia. The discriminant validity of RMET-CV-R in undereducated, older patients demonstrates the feasibility of administering revised versions of RMET to patients who may otherwise be considered ineligible due to education or age by changing the method of test administration and carefully assessing respondents' ability to complete the task successfully.
A theoretical model is presented for the steady multi-layered flow induced by a plane vertically distributed buoyancy source producing a turbulent wall plume in a ventilated box. While aspects of the stratification and rate of fluid exchange between box and exterior have been studied previously, the streamline pattern and velocity field have not been considered until now, despite having potentially important practical implications for achieving comfort in naturally ventilated buildings and for the indoor spread of airborne contagions. The boundary condition at the wall for each layer is established by deducing the turbulent entrainment rate. Using conformal mapping techniques and Poisson's integral theorem, closed-form solutions for the streamfunction of the induced flow in each layer are established. While the flow near the ceiling was overlooked in the classic model for the multi-layered stratification, after considering the possible flow scenarios, the stratification is re-evaluated herein by incorporating an entraining ceiling current. With a markedly thinner top layer, the refined stratification matches well with the available experimental observations, the restrictions we place on the applicability of the model overcoming the previous over-prediction in the number of interfaces. The magnitude of the dimensionless flow velocity, independent of the wall buoyancy flux and physical scale of the box, decreases significantly with the number of layers. Three types of layer, each with a distinct induced flow pattern, are distinguished and their implications for room airflow considered. Notably, the flow in the base layer represents a continual and smooth flushing of air between the inlet opening and the wall plume, whereas an intermediate layer is almost entirely comprised of near-stagnant air.
OBJECTIVES/GOALS: The purpose of this secondary data analysis was to identify latent subgroups of seriously ill adults based on multiple chronic conditions and mortality risk using the CCI. This study was conducted by performing a secondary analysis of data from a randomized controlled trial of seriously ill patients receiving palliative care. METHODS/STUDY POPULATION: A cross-sectional analysis of baseline CCI data was conducted. 381 seriously ill adults receiving palliative care were in the original study. Latent subgroups were identified based on the CCI by conducting a latent class analysis in MPlus. The LCA was modeled on each of the 19 disease items as binary latent predictor variables, an additional binary variable representing presence of any disease not accounted for by the CCI, and a final categorical variable representing the total CCI score divided based on clinically significant cutoffs including zero, low (> = 1-<2), moderate (> = 2-<5), and high CCI (> = 5). RESULTS/ANTICIPATED RESULTS: Three distinct latent subgroups were identified based on the CCI. Latent subgroup 1 included those with a low-moderate CCI consisting of MCC and non-Metastatic Cancers (n = 178), with 45% of this group having chronic obstructive pulmonary disease. The second two subgroups included individuals with a high CCI or a score greater than or equal to 5. Latent subgroup 2 (n = 64) was comprised of individuals with MCC and non-metastatic cancer. Latent subgroup 3 (n = 139) included individuals with metastatic cancer. DISCUSSION/SIGNIFICANCE OF IMPACT: In a sample of seriously ill adults with MCC, latent subgroups were identified consisting of individuals with low, moderate, or high CCI. The low to moderate CCI group consists of individuals with chronic conditions including COPD, congestive heart failure, myocardial infarction, cardiovascular disease. There were two subgroups with high CCI scores and the differentiating factor between the two subgroups was the presence of metastatic cancer in latent subgroup 3. The identification of latent subgroups sets the groundwork for further analyses to compare differences in symptom burden, quality of life, and functional status between groups. The findings have the potential to inform future studies seeking to better characterize seriously adults with MCC based on their disease burden and mortality risk.
OBJECTIVES/GOALS: To examine the relationship between epigenetic age acceleration (EAA) and depressive symptoms in a cohort of African American women (AAW) with cardiometabolic conditions (CMC) including hypertension, diabetes, obesity; and to explore clinical phenotypes of depressive symptoms in this population. METHODS/STUDY POPULATION: This secondary analysis utilized genomic and longitudinal clinical data from AAW in the InterGEN cohort (n = 250). EWAS data was used to estimate EAA based on the Horvath method, which incorporates the DNA methylation statuses at 353 specific CpG sites and regresses this epigenetic age on chronological age to determine EAA. Pearson’s correlations and linear regression will be used to examine the relationship between EAA and depressive symptoms and a linear mixed model will investigate this relationship over four time points during a two-year period. Clinical phenotyping of depressive symptoms will be explored using a cluster analysis. RESULTS/ANTICIPATED RESULTS: Analysis is underway and will be complete by the time of presentation. We hypothesize that higher EAA will associate with higher depressive symptoms and poorer trajectories over time. We expect that this relationship may be meditated by the presence of CMCs. Exploratory analysis of clinical phenotyping is expected to provide descriptive evidence with respect to specific depressive symptoms or clusters which are most associated with EAA and CMCs. These results will address several gaps. To our knowledge, this is the first study to examine the relationship of EAA and depressive symptoms considering the role of CMC, in a historically understudied population with disproportionate risk. DISCUSSION/SIGNIFICANCE OF IMPACT: Depression limits life quality and quantity and is highly comorbid in CMC. AAW have high risk of comorbidity, and this study furthers knowledge of depression and aging with a clinically accessible marker and aids recognition of a heterogenous phenotype in an undertreated population.
Hill (Twin Research and Human Genetics, Vol. 21, 2018, 84–88) presented a critique of our recently published paper in Cell Reports entitled ‘Large-Scale Cognitive GWAS Meta-Analysis Reveals Tissue-Specific Neural Expression and Potential Nootropic Drug Targets’ (Lam et al., Cell Reports, Vol. 21, 2017, 2597–2613). Specifically, Hill offered several interrelated comments suggesting potential problems with our use of a new analytic method called Multi-Trait Analysis of GWAS (MTAG) (Turley et al., Nature Genetics, Vol. 50, 2018, 229–237). In this brief article, we respond to each of these concerns. Using empirical data, we conclude that our MTAG results do not suffer from ‘inflation in the FDR [false discovery rate]’, as suggested by Hill (Twin Research and Human Genetics, Vol. 21, 2018, 84–88), and are not ‘more relevant to the genetic contributions to education than they are to the genetic contributions to intelligence’.
A past history of self-harm is a significant risk factor for suicide in older people. The aims of this study are to (i) characterize older people who present with self-harm to emergency departments (EDs); and (ii) determine the predictors for repeat self-harm and suicide.
Demographic and clinical data were retrospectively collected on older people (age 65+ years), who presented to seven EDs in New Zealand following an episode of self-harm between 1st July 2010 and 30th June 2013. In addition, 12-month follow-up information on repeat self-harm and suicide was collected.
The sample included 339 older people (55.2% female) with an age range of 65–96 years (mean age = 75.0; SD = 7.6). Overdose (68.7%) was the most common method of self-harm. 76.4% of the self-harm cases were classified as suicide attempts. Perceived physical illness (47.8%) and family discord (34.5%) were the most common stressors. 12.7% of older people repeated self-harm and 2.1% died by suicide within 12 months. Older people who had a positive blood alcohol reading (OR = 3.87, 95% Cl = 1.35–11.12, p = 0.012) and were already with mental health services at the index self-harm (OR = 2.73, 95% Cl = 1.20–6.25, p = 0.047) were more likely to repeat self-harm/suicide within 12 months.
Older people who self-harm are at very high risk of repeat self-harm and suicide. Screening and assessment for alcohol use disorders should be routinely performed following a self-harm presentation, along with providing structured psychological treatment as an adjunct to pharmacological treatment for depression and interventions to improve the person's resilience resources.
The aim of this study was to determine the factors associated with a feeling of well-being using the Edmonton Symptom Assessment Scale (ESAS)–Feeling of Well-Being item (ESAS–FWB; where 0 = best and 10 = worst) among advanced lung or non-colonic gastrointestinal cancer patients who were referred to an outpatient palliative care clinic (OPCC). We also examined the association of performance on the ESAS–FWB with overall survival (OS).
We reviewed the records of consecutive patients with incurable advanced lung cancer and non-colonic gastrointestinal cancer presenting to an OPCC from 1 January 2008 through to 31 December 2013. Descriptive statistics were employed to summarize patient characteristics. Multivariate regression analysis was used to determine the factors associated with ESAS–FWB severity. We also examined the association of ESAS–FWB scores and survival using Kaplan–Meier survival analysis.
A total of 826 evaluable patients were analyzed (median age = 62 years, 57% male). Median ESAS–FWB scores were five times the interquartile range (5 × IQR; 3–7). ESAS–FWB score was found to be significantly associated with ESAS fatigue (OR = 2.31, p < 0.001); anxiety (OR = 1.98, p < 0.001); anorexia (OR = 2.31, p < 0.001); cut down, annoyed, guilty, eye opener (CAGE) score (hazard ratio [HR] = 1.80, p = 0.008); and family caregiver distress (HR = 1.93, p = 0.002). A worse ESAS–FWB score was significantly associated with decreased OS (r = –0.18, p < 0.001). However, ESAS–FWB score was not independently associated with OS in the final multivariate model (p = 0.35), which included known major clinical prognostic factors.
Worse ESAS–FWB scores were significantly associated with high scores on ESAS fatigue, anorexia, anxiety, CAGE, and family caregiver distress. More research is necessary to understand how palliative care interventions are capable of improving the contributory factors related to ESAS–FWB score.
Although outcomes among people with schizophrenia differ by social context, this has rarely been examined across rural v. urban settings. For individuals with schizophrenia, employment is widely recognised as a critical ingredient of social integration.
To compare employment for people with schizophrenia in rural v. urban settings in China.
In a large community-based study in four provinces representing 12% of China's population, we identified 393 people with schizophrenia (112 never treated). We used adjusted Poisson regression models to compare employment for those living in rural (n = 297) v. urban (n = 96) settings.
Although rural and urban residents had similar impairments due to symptoms, rural residents were three times more likely to be employed (adjusted relative risk 3.27, 95% Cl 2.11-5.07, P<0.001).
People with schizophrenia have greater opportunities to use their capacities for productive work in rural than urban settings in China. Contextual mechanisms that may explain this result offer a useful focus for future research.
This paper reports on the fabrication and characterization of thin-film nanocomposites comprised of tangled carbon nanotubes in a polymer matrix. The concentration of nanotubes in the polymer was significantly increased using detonation nanodiamonds. Nanodiamonds reduce the surface forces between the polymer and the nanotubes and mitigate the agglomeration problem of nanotubes in polymer. This resulted in thinner and more uniform networks that are efficient absorbers of infrared energy over a broad spectrum, ranging from the visible to the mid-wavelength infrared. An infrared absorbance of 97% was achieved for a 1.6 μm thick nanocomposite film across the spectral range of 714 nm to 5 μm. The films are mechanically and thermally stable up to 300 °C, and can be integrated with microbolometers to enhance their responsivity.
This work comprises the structural characterization of Eucalyptus and Pinus radiata pulp fibers and their corresponding fibrillated materials, based on quantitative electron microscopy techniques. Compared to hardwood fibers, the softwood fibers have a relatively open structure of the fiber wall outer layers. The fibrillation of the fibers was performed mechanically and chemi-mechanically. In the chemi-mechanical process, the pulp fibers were subjected to a TEMPO-mediated oxidation to facilitate the homogenization. Films were made of the fibrillated materials to evaluate some structural properties. The thicknesses and roughnesses of the films were evaluated with standardized methods and with scanning electron microscopy (SEM), in backscattered electron imaging mode. Field-emission SEM (FE-SEM) and transmission electron microscopy (TEM) were performed to quantify the nanofibril morphology. In this study, we give additional and significant evidences about the suitability of electron microscopy techniques for quantification of nanofibril structures. In addition, we conclude that standard methods are not suitable for estimating the thickness of films having relatively rough surfaces. The results revealed significant differences with respect to the morphology of the fibrillated material. The differences are due to the starting raw material and to the procedure applied for the fibrillation.
In densely-populated cities or indoor environments, limited visibility to satellites and severe multipath effects significantly affect the accuracy and reliability of satellite-based positioning systems. To meet the needs of “seamless navigation” in these challenging environments an advanced terrestrial positioning system is under development. This system is based upon Ultra-Wideband (UWB) technology, which is a promising candidate for this application due to good time domain resolution and immunity to multipath. This paper presents a detailed analysis of two key aspects of the UWB signal design that will allow it to be used as the basis of such a high performance positioning system: the modulation scheme and the multiple access technique. These two aspects are evaluated in terms of spectral efficiency and synchronisation performance over multipath channels. Thus this paper identifies optimal modulation and multiple access techniques for a long range, high performance terrestrial positioning system using UWB.
Brucellosis is a zoonotic disease caused by a number of Brucella species and is characterized by chronic macrophage infection. However, genes that may contribute to intracellular survival of the Brucella species are not well studied. This review presents, first, genomic islands that are present or absent in various Brucella species that may help establish Brucella infection and survival strategies. Second, the alteration in macrophage transcription by Brucella to permit its long-term survival within this hostile intracellular environment. A large number of macrophage gene transcripts are altered following Brucella infection indicating that Brucella is not a silent invader of host cells. Macrophage transcript levels associated with inflammation, apoptosis, signal transduction and vesicular intracellular trafficking are altered during Brucella infection, and likely contribute to intracellular survival of Brucella. Lastly, the host–pathogen interaction events associated with Brucella infection in living mice visualized in real-time using biophotonic imaging. Mice are often used to evaluate Brucella infections; however, Brucella dissemination and pathogenesis is poorly understood in mice. Biophotonic imaging of Brucella infections revealed sites of bacterial localization similar to human infections and different patterns of infection by attenuated or virulent Brucella.
New poly(fluorene-thiophene) alternating copolymers are described in which either the dioctylfluorene or bithiophene units in poly(9,9-dioctylfluorene-alt-bithiophene) (F8T2) are replaced by other fluorene or thiophene-based groups, respectively. Improvements in solubility are realized when the bithiophene unit of F8T2 is replaced by dihexylterthiophene or dihexylpentathiophene units. Melting temperatures are also lowered by 50 – 100°C in these polymers when compared to F8T2. Replacement of the bithiophene unit of F8T2 with a dihexylpentathiophene unit also results in a significant improvement in hysteresis (< 2 V vs. 3.5 – 5 V for F8T2). Initial results are also reported on the thermal cleavage of the C8 side groups of F8T2, which yields an insoluble polymeric semiconductor film that continues to exhibit transistor switching characteristics as part of a bottom gate device.