On the dynamics of flame edges in diffusion-flame/vortex interactions

We analyze the local flame extinction and reignition of a counterflow diffusion flame perturbed by a laminar vortex ring. Local flame extinction leads to the appearance of flame edges separating the burning and extinguished regions of the distorted mixing layer. The dynamics of these edges is modeled based on previous numerical results, with heat release effects fully taken into account, which provide the propagation velocity of triple and edge flames in terms of the upstream unperturbed value of the scalar dissipation. The temporal evolution of the mixing layer is determined using the classical mixture fraction approach, with both unsteady and curvature effects taken into account. Although variable density effects play an important role in exothermic reacting mixing layers, in this paper the description of the mixing layer is carried out using the constant density approximation, leading to a simplified analytical description of the flow field. The mathematical model reveals the relevant nondimensional parameters governing diffusion-flame/vortex interactions and provides the parameter range for the more relevant regime of local flame extinction followed by reignition via flame edges. Despite the simplicity of the model, the results show very good agreement with previously published experimental results

Landscape response to late Pleistocene climate change in NW Argentina: Sediment flux modulated by basin geometry and connectivity

Citation: Schildgen, T. F., Robinson, R. A. J., Savi, S., Phillips, W. M., Spencer, J. Q. G., Bookhagen, B., . . . Strecker, M. R. (2016). Landscape response to late Pleistocene climate change in NW Argentina: Sediment flux modulated by basin geometry and connectivity. Journal of Geophysical Research-Earth Surface, 121(2), 392-414. doi:10.1002/2015jf003607Fluvial fill terraces preserve sedimentary archives of landscape responses to climate change, typically over millennial timescales. In the Humahuaca Basin of NW Argentina (Eastern Cordillera, southern Central Andes), our 29 new optically stimulated luminescence ages of late Pleistocene fill terrace sediments demonstrate that the timing of past river aggradation occurred over different intervals on the western and eastern sides of the valley, despite their similar bedrock lithology, mean slopes, and precipitation. In the west, aggradation coincided with periods of increasing precipitation, while in the east, aggradation coincided with decreasing precipitation or more variable conditions. Erosion rates and grain size dependencies in our cosmogenic Be-10 analyses of modern and fill terrace sediments reveal an increased importance of landsliding compared to today on the west side during aggradation, but of similar importance during aggradation on the east side. Differences in the timing of aggradation and the Be-10 data likely result from differences in valley geometry, which causes sediment to be temporarily stored in perched basins on the east side. It appears as if periods of increasing precipitation triggered landslides throughout the region, which induced aggradation in the west, but blockage of the narrow bedrock gorges downstream from the perched basins in the east. As such, basin geometry and fluvial connectivity appear to strongly influence the timing of sediment movement through the system. For larger basins that integrate subbasins with differing geometries or degrees of connectivity (like Humahuaca), sedimentary responses to climate forcing are likely attenuated

Clinical and virological characteristics of hospitalised COVID-19 patients in a German tertiary care centre during the first wave of the SARS-CoV-2 pandemic: a prospective observational study

Purpose: Adequate patient allocation is pivotal for optimal resource management in strained healthcare systems, and requires detailed knowledge of clinical and virological disease trajectories. The purpose of this work was to identify risk factors associated with need for invasive mechanical ventilation (IMV), to analyse viral kinetics in patients with and without IMV and to provide a comprehensive description of clinical course. Methods: A cohort of 168 hospitalised adult COVID-19 patients enrolled in a prospective observational study at a large European tertiary care centre was analysed. Results: Forty-four per cent (71/161) of patients required invasive mechanical ventilation (IMV). Shorter duration of symptoms before admission (aOR 1.22 per day less, 95% CI 1.10-1.37, p < 0.01) and history of hypertension (aOR 5.55, 95% CI 2.00-16.82, p < 0.01) were associated with need for IMV. Patients on IMV had higher maximal concentrations, slower decline rates, and longer shedding of SARS-CoV-2 than non-IMV patients (33 days, IQR 26-46.75, vs 18 days, IQR 16-46.75, respectively, p < 0.01). Median duration of hospitalisation was 9 days (IQR 6-15.5) for non-IMV and 49.5 days (IQR 36.8-82.5) for IMV patients. Conclusions: Our results indicate a short duration of symptoms before admission as a risk factor for severe disease that merits further investigation and different viral load kinetics in severely affected patients. Median duration of hospitalisation of IMV patients was longer than described for acute respiratory distress syndrome unrelated to COVID-19

Self- or parent report of (co-occurring) internalizing and externalizing problems, and basal or reactivity measures of HPA-axis functioning:A systematic evaluation of the internalizing-hyperresponsivity versus externalizing-hyporesponsivity HPA-axis hypot

<p>Background: Previous research findings on the link between adolescents' psychopathology and hypothalamic-pituitary-adrenal (HPA) axis activity have been heterogeneous.</p><p>Method: Adolescents (n = 211) with a preadolescent DSM-IV diagnosis participated in a lab-based social stress task. Saliva cortisol was assessed at awakening and during social stress. It was investigated if continuous measures of internalizing and externalizing problems and their interaction, using both self- and parent report, were associated with basal or reactivity measures of HPA-axis functioning</p><p>Results: During social stress, an enhanced total release of cortisol was associated with self-reported internalizing problems and a blunted total release of cortisol with self-reported externalizing problems. Post hoc analyses revealed that the association between enhanced cortisol output and internalizing problems held for boys but not for girls. Associations with morning cortisol measures were overall weak</p><p>Conclusions: Only in the context of stress, and particularly when based on self-report, blunted cortisol output was associated with externalizing and enhanced cortisol output with internalizing problems. Our broad approach demonstrates the importance of who reports on psychopathology, the use of dimensional measures of psychopathology, simultaneous analysis of internalizing and externalizing problems, and the use of awakening and social stress related measures of cortisol. (C) 2013 Elsevier B. V. All rights reserved.</p>

Neutrophil to lymphocyte ratio and response to tyrosine kinase inhibitor therapy in metastatic renal cell carcinoma

477 Background: Neutrophil to lymphocyte ratio (NLR) and platelet to lymphocyte ratio (PLR) are markers of host inflammation and have prognostic value in many solid tumors. Here we aimed to explore the association of NLR and PLR with response to tyrosine kinase inhibitor (TKI) treatment in metastatic renal cell carcinoma (mRCC). Methods: Data from patients with mRCC treated at the Princess Margaret Cancer Centrein Toronto with a TKI as first-line treatment were retrospectively collected. The association of several variables with response to treatment (complete response [CR] or partial response [PR] vs. stable disease &gt; 3 months [SD] or progressive disease [PD]) was assessed by binary logistic regression. Significant variables were dichotomized and cut-offs selected by the area under the receiver operating characteristic (AUC) curve. Results: Data from 157 patients treated between 11/2004 and 09/2012 were analyzed. Median age at start of TKI treatment was 61 years and first-line treatment was sunitinib, sorafenib, and other in 49%, 43%, and 8% of patients, respectively. Best response was CR/PR, SD, and PD in 27%, 55%, and 18% patients. On multivariable analysis NLR &gt; 2.5 and Karnofsky Performance Status (KPS) &lt; 90% were associated with a lower likelihood of response and each allocated a score of 1 unit. Response rates for a score of 0, 1, or 2 were 45% (29-61%), 28% (17-38%), 10% (1-19%), respectively. PLR did not retain association with response in multivariable analysis. Conclusions: NLR and KPS are associated with response to TKI treatment in mRCC. Data from an external validation set will also be presented. </jats:p

In-situ\textit {In-situ} control of microdischarge characteristics in unipolar pulsed plasma electrolytic oxidation of aluminum

Microdischarges occurring during plasma electrolytic oxidation are the main mechanism promoting oxide growth compared to classical anodization. When the dissipated energy by microdischarges during the coating process gets too large, high-intensity discharges might occur, which are detrimental to the oxide layer. In bipolar pulsed plasma electrolytic oxidation a so called "soft-sparking" mode limits microdischarge growth. This method is not available for unipolar pulsing and for all material combinations. In this work, the authors provide a method to control the size- and intensity distributions of microdischarges by utilizing a multivariable closed-loop control. $\textit {In-situ}$ detection of microdischarge properties by CCD-camera measurements and fast image processing algorithms are deployed. The visible size of microdischarges is controlled by adjusting the duty cycle in a closed-loop feedback scheme, utilizing a PI-controller. Uncontrolled measurements are compared to controlled cases. The microdischarge sizes are controlled to a mean value of $\it A$ = 5 ­­­­· $10^{-3}$ $mm^{2}$ and $\it A$ = 7 ­­­­· $10^{-3}$ $mm^{2}$, respectively. Results for controlled cases show, that size and intensity distributions remain constant over the processing time of 35 minutes. Larger, high-intensity discharges can be effectively prevented. Optical emission spectra reveal, that certain spectral lines can be influenced or controlled with this method. Calculated black body radiation fits with very good agreement to measured continuum emission spectra $\it T$ = 3200 K. Variance of microdischarge size, emission intensity and continuum radiation between consecutive measurements is reduced to a large extent, promoting uniform microdischarge and oxide layer properties. A reduced variance in surface defects can be seen in SEM measurements, after coating for 35 minutes, for controlled cases. Surface defect study shows increased number density of microdischarge impact regions, while at the same time reducing pancake diameters, implying reduced microdischarge energies compared to uncontrolled cases

Prognostic role of platelet to lymphocyte ratio in solid tumors: a systematic review and meta-analysis

BACKGROUND: Inflammation influences cancer development and progression. An elevated platelet to lymphocyte ratio (PLR), a marker of inflammation, has been linked to poor prognosis in several malignancies. Here, we quantify the prognostic impact of this biomarker. METHODS: A systematic review of databases was conducted to identify publications exploring the association of blood PLR and overall survival (OS) in solid tumors. Data were pooled in a meta-analysis. Pooled HRs for OS by disease group and by PLR cutoff groups were computed and weighted using generic inverse-variance and random-effect modeling. RESULTS: Twenty studies comprising 12,754 patients were assessed. Cutoffs for PLR defining risk groups ranged from 150 to 300 and were dichotomous (12 studies; group 1) or split into three groups (300, 8 studies; group 2). Higher PLR was associated with significantly worse OS in group 1 [HR = 1.87; 95% confidence interval (CI, 1.49-2.34); P < 0.001] and with a nonsignificant association in group 2 (HR per higher category = 1.21; 95%CI, 0.97-1.50; P = 0.10). The size of effect of PLR on OS was greater for metastatic disease (HR[group 1] = 2.0; 95% CI, 1.6-2.7; HR[group 2] = 1.6; 95% CI, 1.1-2.4) than for early-stage disease (HR[group 1] = 1.5; 95% CI, 1.0-2.2; HR[group 2] = 1.0; 95% CI, 0.8-1.3). A significant association was observed for colorectal, hepatocellular, gastroesophageal, ovarian, and pancreatic carcinoma in group 1 and for colorectal cancers in group 2. CONCLUSION: A high PLR is associated with worse OS in various solid tumors. Further research of its regulation and relevance in daily practice is warranted. IMPACT: PLR is a readily available and inexpensive biomarker with independent prognostic value in solid tumors

Sex-specific differences in genetic and nongenetic determinants of mean platelet volume: results from the Gutenberg Health Study

Mean platelet volume (MPV), a measure of platelet size, is a potential biological marker of platelet function. To date, a comprehensive analysis including known genetic and nongenetic factors that determine MPV is still lacking. MPV has been evaluated in 15 010 individuals from the population-based Gutenberg Health Study. Genetic information was available for 4175 individuals. Our results showed that age (β, 0.0346; 95% confidence interval [CI], 0.0255 to 0.0436), cardiovascular risk factors (CVRFs) such as smoking (β, 0.178; 95% CI, 0.128 to 0.229), hypertension (β, 0.05; 95% CI, 0.00289 to .0981), and high glucose level (β, 0.00179; 95% CI, 0.0006 to 0.00299) were linked with higher MPV in males only. Intake of oral contraceptives (β, 0.150; 95% CI, 0.0649 to 0.236) and menstruation (β, 0.123; 95% CI, 0.0231 to 0.224) were strongly associated with higher MPV in females. Seven single nucleotide polymorphisms (SNPs) for females and 4 SNPs for males were associated with higher MPV. The full model, including age, CVRFs, laboratory parameters, medications, and genetic variation, explained 20.4% of the MPV variance in females and 18.6% in males. The curves of cumulative mortality, stratified for sex, showed worse survival for males only with MPV >9.96 fL vs MPV ≤9.96 fL (P < .0001). This study provides evidence for heterogeneity in the profile of determinants for MPV between sexes. The observed interactions between genetic variability, CVRFs, and MPV and its association with the development of cardiovascular disease or thrombotic risk need to be further investigated