Improved inference for the generalized Pareto distribution under linear, power and exponential normalization

summary:We discuss three estimation methods: the method of moments, probability weighted moments, and L-moments for the scale parameter and the extreme value index in the generalized Pareto distribution under linear normalization. Moreover, we adapt these methods to use for the generalized Pareto distribution under power and exponential normalizations. A simulation study is conducted to compare the three methods on the three models and determine which is the best, which turned out to be the probability weighted moments. A new computational technique for improving fitting quality is proposed and tested on two real-world data sets using the probability weighted moments. We looked back at various maximal data sets that had previously been addressed in the literature and for which the generalized extreme value distribution under linear normalization had failed to adequately explain them. We use the suggested procedure to find good fits

Mortality of emergency abdominal surgery in high-, middle- and low-income countries

Background: Surgical mortality data are collected routinely in high-income countries, yet virtually no low- or middle-income countries have outcome surveillance in place. The aim was prospectively to collect worldwide mortality data following emergency abdominal surgery, comparing findings across countries with a low, middle or high Human Development Index (HDI). Methods: This was a prospective, multicentre, cohort study. Self-selected hospitals performing emergency surgery submitted prespecified data for consecutive patients from at least one 2-week interval during July to December 2014. Postoperative mortality was analysed by hierarchical multivariable logistic regression. Results: Data were obtained for 10 745 patients from 357 centres in 58 countries; 6538 were from high-, 2889 from middle- and 1318 from low-HDI settings. The overall mortality rate was 1⋅6 per cent at 24 h (high 1⋅1 per cent, middle 1⋅9 per cent, low 3⋅4 per cent; P < 0⋅001), increasing to 5⋅4 per cent by 30 days (high 4⋅5 per cent, middle 6⋅0 per cent, low 8⋅6 per cent; P < 0⋅001). Of the 578 patients who died, 404 (69⋅9 per cent) did so between 24 h and 30 days following surgery (high 74⋅2 per cent, middle 68⋅8 per cent, low 60⋅5 per cent). After adjustment, 30-day mortality remained higher in middle-income (odds ratio (OR) 2⋅78, 95 per cent c.i. 1⋅84 to 4⋅20) and low-income (OR 2⋅97, 1⋅84 to 4⋅81) countries. Surgical safety checklist use was less frequent in low- and middle-income countries, but when used was associated with reduced mortality at 30 days. Conclusion: Mortality is three times higher in low- compared with high-HDI countries even when adjusted for prognostic factors. Patient safety factors may have an important role. Registration number: NCT02179112 (http://www.clinicaltrials.gov)

31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two

Background The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd. Methods We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background. Results First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001). Conclusions In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival

Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

Correction to: Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

The original version of this article unfortunately contained a mistake

Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

Biosurfactant production by haloalkaliphilic Bacillus strains isolated from Red Sea, Egypt

This study aimed to produce biosurfactant by extremophilic marine bacteria. Twenty-one oil-spilled seawater samples were collected from Shalateen, Red Sea, Egypt. Two promising morphologically distinct biosurfactant-producing marine bacteria, SH20 and SH24, were selected. They were grown on minimal salt medium (MSM) and the biosurfactant production was evaluated and detected after 24 h using drop collapsing test, blood hemolysis, emulsification index and surface tension. SH20 and SH24 isolates showed the highest emulsification index 57 and 56%, respectively, and have positive results for hemolysis and drop collapse. The two isolates were identified using 16 S rRNA as Bacillus amyloliquefaciens SH20 and Bacillus thuringiensis SH24. Stability of biosurfactant production by both strains was observed at moderate temperature (30 °C), high alkalinity at pH (11) and high salt concentration (15%). An increase of emulsification index tended to be 60 and 69%, respectively, considering the two strains haloalkiphilic bacteria. To study the stability mechanism for extremophilic biosurfactant producers, the protein profile was determined using SDS-PAGE electrophoresis showing some new detected proteins depends on their culturing conditions. Partially purified biosurfactant from the most active strain B. amyloliquefaciens SH20 was chemically determined by FTIR and GCâMS analysis showed characteristic bands, revealed the presence of non-anionic didemnin surfactant. Keywords: Biosurfactant, Haloalkaliphiles, Bacillus sp, SDS-PAGE, FTIR, GCâM

TiO2 NPs-immobilized silica granules: New insight for nano catalyst fixation for hydrogen generation and sustained wastewater treatment

In heterogeneous catalytic processes, immobilization of the functional material over a proper support is a vital solution for reusing and/or avoiding a secondary pollution problem. The study introduces a novel approach for immobilizing R25 NPs on the surface of silica granules using hydrothermal treatment followed by calcination process. Due to the privileged characteristics of the subcritical water, during the hydrothermal treatment process, the utilized R25 NPs were partially dissolved and precipitated on the surface of the silica granules. Calcination at high temperature (700°C) resulted in improving the attachment forces. The structure of the newly proposed composite was approved by 2D and 3D optical microscope images, XRD and EDX analyses. The functionalized silica granules were used in the form of a packed bed for continuous removal of methylene blue dye. The results indicated that the TiO2:sand ratio has a considerable effect on the shape of the dye removal breakthrough curve as the exhaustion point, corresponding to ~ 95% removal, was 12.3, 17.4 and 21.3 min for 1:20, 1:10 and 1:5 metal oxides ratio, respectively. Furthermore, the modified silica granules could be exploited as a photocatalyst for hydrogen generation from sewage wastewaters under direct sunlight with a good rate; 75×10−3 mmol/s. Interestingly, after the ease separation of the used granules, the performance was not affected. Based on the obtained results, the 170°C is the optimum hydrothermal treatment temperature. Overall, the study opens a new avenue for immobilization of functional semiconductors on the surface of sand granules

H3PO4/KOH Activation Agent for High Performance Rice Husk Activated Carbon Electrode in Acidic Media Supercapacitors

H3PO4/KOH combined solution is proposed as a new effective activation agent for activated carbon production from rice husk. Several activated carbon samples were produced by using different volumes of the utilized acid and alkali individually, in addition to the combined solution. FTIR results indicated that the mixed agent partially decomposed the chemical compounds on the rice husk char surface, resulting in an increase in the surface area. Moreover, XRD and EDS analyses showed the presence of a considerable amount of amorphous silica. Electrochemical measurements concluded that the volume of the activation agent solution should be optimized for both single and mixed activation agents. Numerically, for 0.3 g treated rice husk char, the maximum specific capacitance was observed at 7, 10 and 14 mL of H3PO4, KOH (3 M) and mixed (1:1 by volume) activation agents, respectively; the determined specific capacitance values were 73.5, 124.2 and 241.3 F/g, respectively. A galvanostatic charging/discharging analysis showed an approximate symmetrical triangular shape with linear voltage versus time profile which indicates very good electrochemical performance as an electrode in the supercapacitors application. The stability of the proposed activated carbon was checked by performing a cyclic voltammetry measurement for 1000 cycles at 2 mV/s and for 30,000 cycles at 10 mV/s. The results indicate an excellent specific capacitance retention, as no losses were observed