Exploring noise effects in chaotic optical networks

We report the experimental evidence coherence and stochastic resonance in a dynamics of fast chaotic spiking of a semiconductor laser with optical feedback using an external nonwhite noise in the pumping current. We characterize both coherence and stochastic resonance in the time and frequency domain. We show that the regularity of the chaotic pulses in the intensity of laser diod increases when adding noise and it is optimal for some intermediate value of the noise intensity. We find that the power spectrum of the signal develops a peak at a finite frequency at intermediate values of the noise. The results show that noise may help in extracting the periodic signal without synchronization in chaotic communication. Then we reported the effect of external noise numerically on a single system by using bifurcation diagram. Finally, we considered Chaos synchronization in a network of 28 distinct chaotic systems with independent initial conditions when a normal Gaussian noise is added. The transition between non-synchronization to synchronization states using a suitable spatio-temporal representation has been reported. The role of coherence has also been considered. Keywords: Coherence resonance, Stochastic resonance, Control, Nois

SARS-CoV-2 vaccination modelling for safe surgery to save lives: data from an international prospective cohort study

Background Preoperative SARS-CoV-2 vaccination could support safer elective surgery. Vaccine numbers are limited so this study aimed to inform their prioritization by modelling. Methods The primary outcome was the number needed to vaccinate (NNV) to prevent one COVID-19-related death in 1 year. NNVs were based on postoperative SARS-CoV-2 rates and mortality in an international cohort study (surgical patients), and community SARS-CoV-2 incidence and case fatality data (general population). NNV estimates were stratified by age (18–49, 50–69, 70 or more years) and type of surgery. Best- and worst-case scenarios were used to describe uncertainty. Results NNVs were more favourable in surgical patients than the general population. The most favourable NNVs were in patients aged 70 years or more needing cancer surgery (351; best case 196, worst case 816) or non-cancer surgery (733; best case 407, worst case 1664). Both exceeded the NNV in the general population (1840; best case 1196, worst case 3066). NNVs for surgical patients remained favourable at a range of SARS-CoV-2 incidence rates in sensitivity analysis modelling. Globally, prioritizing preoperative vaccination of patients needing elective surgery ahead of the general population could prevent an additional 58 687 (best case 115 007, worst case 20 177) COVID-19-related deaths in 1 year. Conclusion As global roll out of SARS-CoV-2 vaccination proceeds, patients needing elective surgery should be prioritized ahead of the general population

Manganese Deficiency is Associated with Histological Changes in Date Palm Fronds Showing Brittle Leaf Disease Symptoms

Several diseases, pests and physiological disorders threat date palm life. Among them, Brittle leaf disease or, in French, Maladie des feuilles cassantes (MFC) is a lethal disease that has acquired alarming proportions since the 1960s, when it was first observed in southern Tunisia. Up to now no causal agent has been found. Previous studies have reported that brittle fronds are deficient in manganese but the mechanisms involved in symptom expression have not yet been identified. In this study, an anatomical investigation was carried out in order to identify the deleterious effect of MFC on the development and structure of palm fronds. Results showed that in old healthy fronds the major tissue is schlerenchyma, which is characterized by very thick lignified cell walls and is often associated with conducting tissue. Indeed, large vessels are surrounded by schlerenchyma fibers that are strongly lignified when compared with those of young fronds. Diseased young fronds have almost the same shape as the healthy young fronds. Nevertheless, in old diseased fronds MFC induces important structural changes. Xylem and phloem vessels are larger, taking more space through the fibers that are smaller in number and size, and tighter. The larger diameter of the lumen and the lower thickness of the fibers present in the fronds in advanced disease stages, decreases the lignin content of cells walls, leading to an increased frond friability, which gives "the brittle leaf disease" its name

Effect of inorganic or organic copper additions on reproductive performance, lipid metabolism and morphology of organs of dual-purpose breeding hens

A total number of one hundred and twenty (100 female + 20 male) dual propose breeding chickens of Gimmizah strain was housed in individual cages in semi open house during 30-50 wks of age. Birds were distributed randomly into five treatments (20 female + 4 male). The 1st treatment was fed a control, unsupplemented, diet (17.5% CP and 11.4 MJ ME/kg) containing 10 mg Cu/kg by analysis. The 2(nd), 3(rd), 4(th) and 5(th) treatments were fed the control diet supplemented with 60 and 120 mg Cu/kg from inorganic (Copper sulfate pentahydrate) and organic sources (Bioplex (R) Cu-lysine, 10%), respectively. Productive and reproductive performance, egg quality, plasma and yolk cholesterol and histopathology of liver, spleen and intestinal were investigated. Level and/or source of Cu did not significantly affect laying rate, EW, EM, and FCR. Piped embryos significantly (P < 0.004) decreased due to addition of 120 ppm of ICu and 60 ppm of OCu. The tibia Ca percentages significantly (P < 0.005) increased due to Cu supplementation. Level and/or source of Cu significantly (P < 0.01 and P <0.0001) affected plasma cholesterol. Yolk cholesterol significantly decreased with Cu addition at both levels of supplemented Cu sources. The plasma Cu significantly (P < 0.0001) increased with Cu supplementation at 60 and 120 ppm and OCu was more efficient than ICu. In conclusion, Cu level at 10 ppm was adequate for productive and reproductive performance and egg quality of laying hens. Although, addition at 60 ppm OCu decreased cholesterol in plasma and egg yolk this can't be recommended due to its toxic effect on organ morphology confirming EU regulation of 35 ppm as the maximum permitted level

Standardization in Quantitative Imaging: A Multicenter Comparison of Radiomic Features from Different Software Packages on Digital Reference Objects and Patient Data Sets

Radiomic features are being increasingly studied for clinical applications. We aimed to assess the agreement among radiomic features when computed by several groups by using different software packages under very tightly controlled conditions, which included standardized feature definitions and common image data sets. Ten sites (9 from the NCI\u27s Quantitative Imaging Network] positron emission tomography–computed tomography working group plus one site from outside that group) participated in this project. Nine common quantitative imaging features were selected for comparison including features that describe morphology, intensity, shape, and texture. The common image data sets were: three 3D digital reference objects (DROs) and 10 patient image scans from the Lung Image Database Consortium data set using a specific lesion in each scan. Each object (DRO or lesion) was accompanied by an already-defined volume of interest, from which the features were calculated. Feature values for each object (DRO or lesion) were reported. The coefficient of variation (CV), expressed as a percentage, was calculated across software packages for each feature on each object. Thirteen sets of results were obtained for the DROs and patient data sets. Five of the 9 features showed excellent agreement with CV &lt; 1%; 1 feature had moderate agreement (CV &lt; 10%), and 3 features had larger variations (CV ≥ 10%) even after attempts at harmonization of feature calculations. This work highlights the value of feature definition standardization as well as the need to further clarify definitions for some features