Functional response of Stethorus gilvifrons (Col.: Coccinellidae) to different densities of Eutetranychus orientalis (Acari: Tetranychidae) in laboratory

The stage specific functional response of the acarophagous ladybird beetle Stethorus gilvifrons Mulsant to varying densities of citrus brown mite Eutetranychus orientalis (Klein) eggs was examined in a simplified castor bean leaf arena under laboratory conditions. All stages of S. gilvifrons were individually isolated for 24 hours with different prey densities at 30ºC and a photoperiod of 14: 10 (L: D). The number of prey consumed by the predator was checked after 24 hours. Each larval stage of S. gilvifrons showed a type II functional response when 88 eggs out of 120 eggs were consumed by the fourth-instar larva. Based on the random predator equation, the estimated attack rates of S. gilvifrons were 0.065, 0.089, 0.143, 0.125 and 0.046 per hour while the estimated handling times stood at 0.141, 0.166, 0.150, 0.134 and 0.082 per hour for the first, second, third and fourth instar as well as the adult female respectively. The species S. gilvifrons showed to be an effective predator on E. orientalis under controlled conditions. The results suggest that the simultaneous use of the both fourth-instar larvae and adult females of the acarophagous ladybird beetle could increase the rate of predation in the field

Holistic Farsi handwritten word recognition using gradient features

In this paper we address the issue of recognizing Farsi handwritten words. Two types of gradient features are extracted from a sliding vertical stripe which sweeps across a word image. These are directional and intensity gradient features. The feature vector extracted from each stripe is then coded using the Self Organizing Map (SOM). In this method each word is modeled using the discrete Hidden Markov Model (HMM). To evaluate the performance of the proposed method, FARSA dataset has been used. The experimental results show that the proposed system, applying directional gradient features, has achieved the recognition rate of 69.07% and outperformed all other existing methods

Dynamic simulation of boring process

a b s t r a c t This article presents a model to simulate the dynamics of boring process. In boring operations the boring bar should be long and slender; therefore it is easily subjected to vibrations. Tool vibrations result in reduced tool life, poor surface finish and may also introduce chatter. Hence, predicting the vibrational behavior of boring process for certain cutting conditions and tool work-piece properties is of great importance. The proposed method models the cutting tool geometry by B-spline parametric curves. By using B-spline curves it is possible to simulate different tool geometries with a single approach. B-spline curves also enable the modeling of the kinematics of chip formation for different tool work-piece engagement conditions with a single formulation. The boring bar has been modeled by the Euler-Bernoulli beam theory. The simulation process has been implemented with MATLAB. The algorithm consists of different computational modules that are interconnected by a main program. Experimental machining tests have been conducted to verify the validity of the proposed model. Proposed dynamic models have been able to predict the dynamic cutting force components and vibration frequencies with less than 15% deviation. The proposed model has been also able to predict the chatter onset correctly

Temporal associations between morningness/eveningness, problematic social media use, psychological distress and daytime sleepiness: mediated roles of sleep quality and insomnia among young adults

The extant literature has suggested relationships between an individual's chronotype (in relation to morningness/eveningness) and several outcomes, including addictive disorders, psychological distress and daytime sleepiness. Moreover, sleep quality has been proposed to be a mediator in the aforementioned relationships. Consequently, the aim of the present study was to investigate the complex relationship between morningness/eveningness, problematic social media use, psychological distress and daytime sleepiness, with the potential mediators of sleep quality and insomnia. All participants (N = 1,791 [30.1% males]; mean age = 27.2 years, SD = 10.1) completed a battery of psychometric scales, including a reduced version of the Morningness‐Eveningness Questionnaire (at baseline), the Pittsburgh Sleep Quality Index and Insomnia Severity Index (1 month after baseline assessment), the Bergen Social Media Addiction Scale, the Hospital Anxiety and Depression Scale, and the Epworth Sleepiness Scale (2 months after baseline assessment). The impacts of morningness‐eveningness on problematic social media use, anxiety, depression and daytime sleepiness were found in the mediation models. Furthermore, the mediated effects of insomnia and sleep quality were observed. The present study's results emphasize the importance of promoting healthy sleep habits and sleep hygiene behaviours, and that of early detection of sleep problems among individuals who have the eveningness chronotype, because this would significantly improve their health outcomes

Double quick, double click reversible peptide “stapling”

The development of constrained peptides for inhibition of protein–protein interactions is an emerging strategy in chemical biology and drug discovery. This manuscript introduces a versatile, rapid and reversible approach to constrain peptides in a bioactive helical conformation using BID and RNase S peptides as models. Dibromomaleimide is used to constrain BID and RNase S peptide sequence variants bearing cysteine (Cys) or homocysteine (hCys) amino acids spaced at i and i + 4 positions by double substitution. The constraint can be readily removed by displacement of the maleimide using excess thiol. This new constraining methodology results in enhanced α-helical conformation (BID and RNase S peptide) as demonstrated by circular dichroism and molecular dynamics simulations, resistance to proteolysis (BID) as demonstrated by trypsin proteolysis experiments and retained or enhanced potency of inhibition for Bcl-2 family protein–protein interactions (BID), or greater capability to restore the hydrolytic activity of the RNAse S protein (RNase S peptide). Finally, use of a dibromomaleimide functionalized with an alkyne permits further divergent functionalization through alkyne–azide cycloaddition chemistry on the constrained peptide with fluorescein, oligoethylene glycol or biotin groups to facilitate biophysical and cellular analyses. Hence this methodology may extend the scope and accessibility of peptide stapling

Feeding and growth efficiency indices of rainbow trout (Oncorhynchus mykiss) during different deprivation and re-feeding periods

This study aimed to have more insight into the effects of different feed deprivation periods on the growth and feed utilization indices of fish. The study lasted for eight weeks. Four treatments with three replicates including a control group without feed deprivation and treatment 1, 2 and 3 with 1, 2 and 3 week(s) of feed deprivation, respectively, were set up. Fish were fed ad lib for five weeks from week four up to the end of week eight, twice daily. The initial weight was (44.01g ±0.19 c S.E.M). At the end of the deprivation period (day 21 of experiment) starved fish including treatments 1 (46.90g ±2.74), 2 (46.04g ±1.21) and 3 (41.04g ±0.22) had significantly lower weights (P0.05). Different body compartments (crude protein, fat and energy) were not significantly differed among the treatments at the end of the starvation period (P>0.05). Results indicated that the fish could tolerate the starvation and could finally compensate for the final body weight

Unsupervised automated retinal vessel segmentation based on Radon line detector and morphological reconstruction

Abstract Retinal blood vessel segmentation and analysis is critical for the computer‐aided diagnosis of different diseases such as diabetic retinopathy. This study presents an automated unsupervised method for segmenting the retinal vasculature based on hybrid methods. The algorithm initially applies a preprocessing step using morphological operators to enhance the vessel tree structure against a non‐uniform image background. The main processing applies the Radon transform to overlapping windows, followed by vessel validation, vessel refinement and vessel reconstruction to achieve the final segmentation. The method was tested on three publicly available datasets and a local database comprising a total of 188 images. Segmentation performance was evaluated using three measures: accuracy, receiver operating characteristic (ROC) analysis, and the structural similarity index. ROC analysis resulted in area under curve values of 97.39%, 97.01%, and 97.12%, for the DRIVE, STARE, and CHASE‐DB1, respectively. Also, the results of accuracy were 0.9688, 0.9646, and 0.9475 for the same datasets. Finally, the average values of structural similarity index were computed for all four datasets, with average values of 0.9650 (DRIVE), 0.9641 (STARE), and 0.9625 (CHASE‐DB1). These results compare with the best published results to date, exceeding their performance for several of the datasets; similar performance is found using accuracy

The status of hepatitis C virus infection among people who inject drugs in the Middle East and North Africa.

BACKGROUND AND AIMS: People who inject drugs (PWID) are a key population at high risk of hepatitis C virus (HCV) infection. The aim of this study was to delineate the epidemiology of HCV in PWID in the Middle East and North Africa (MENA). METHODS: Syntheses of data were conducted on the standardized and systematically assembled databases of the MENA HCV Epidemiology Synthesis Project, 1989-2018. Random-effects meta-analyses and meta-regressions were performed. Meta-regression variables included country, study site, year of data collection and year of publication [to assess trends in HCV antibody prevalence over time], sample size and sampling methodology. Numbers of chronically infected PWID across MENA were estimated. The Shannon Diversity Index was calculated to assess genotype diversity. RESULTS: Based on 118 HCV antibody prevalence measures, the pooled mean prevalence in PWID for all MENA was 49.3% [95% confidence interval (CI) = 44.4-54.1%]. The country-specific pooled mean ranged from 21.7% (95% CI = 4.9-38.6%) in Tunisia to 94.2% (95% CI = 90.8-96.7%) in Libya. An estimated 221 704 PWID were chronically infected, with the largest numbers found in Iran at 68 526 and in Pakistan at 46 554. There was no statistically significant evidence for a decline in HCV antibody prevalence over time. Genotype diversity was moderate (Shannon Diversity Index of 1.01 out of 1.95; 52.1%). The pooled mean percentage for each HCV genotype was highest in genotype 3 (42.7%) and in genotype 1 (35.9%). CONCLUSION: Half of people who inject drugs in the Middle East and North Africa appear to have ever been infected with hepatitis C virus, but there are large variations in antibody prevalence among countries. In addition to > 200 000 chronically infected current people who inject drugs, there is an unknown number of people who no longer inject drugs who may have acquired hepatitis C virus during past injecting drug use. Harm reduction services must be expanded, and innovative strategies need to be employed to ensure accessibility to hepatitis C virus testing and treatment

IL-35 Is a Novel Responsive Anti-inflammatory Cytokine — A New System of Categorizing Anti-inflammatory Cytokines

It remains unknown whether newly identified anti-inflammatory/immunosuppressive cytokine interleukin-35 (IL-35) is different from other anti-inflammatory cytokines such as IL-10 and transforming growth factor (TGF)-β in terms of inhibition of inflammation initiation and suppression of full-blown inflammation. Using experimental database mining and statistical analysis methods we developed, we examined the tissue expression profiles and regulatory mechanisms of IL-35 in comparison to other anti-inflammatory cytokines. Our results suggest that in contrast to TGF-β, IL-35 is not constitutively expressed in human tissues but it is inducible in response to inflammatory stimuli. We also provide structural evidence that AU-rich element (ARE) binding proteins and microRNAs target IL-35 subunit transcripts, by which IL-35 may achieve non-constitutive expression status. Furthermore, we propose a new system to categorize anti-inflammatory cytokines into two groups: (1) the house-keeping cytokines, such as TGF-β, inhibit the initiation of inflammation whereas (2) the responsive cytokines including IL-35 suppress inflammation in full-blown stage. Our in-depth analyses of molecular events that regulate the production of IL-35 as well as the new categorization system of anti-inflammatory cytokines are important for the design of new strategies of immune therapies