1,427 research outputs found
Context based clearing procedure: A niching method for genetic algorithms
AbstractIn this paper we present CBC (context based clearing), a procedure for solving the niching problem. CBC is a clearing technique governed by the amount of heterogeneity in a subpopulation as measured by the standard deviation. CBC was tested using the M7 function, a massively multimodal deceptive optimization function typically used for testing the efficiency of finding global optima in a search space. The results are compared with a standard clearing procedure. Results show that CBC reaches global optima several generations earlier than in the standard clearing procedure. In this work the target was to test the effectiveness of context information in controlling clearing. A subpopulation includes a fixed number of candidates rather than a fixed radius. Each subpopulation is then cleared either totally or partially according to the heterogeneity of its candidates. This automatically regulates the radius size of the area cleared around the pivot of the subpopulation
Effect of extreme low and high temperatures on the almond moth, Ephestia cautella (Walker) (Lepidoptera: Pyralidae)
he different immature stages of the almond moth, Ephestia cautella (Walker) were exposed to low temperature of -5ºC for different exposure times. Exposure of eggs to 240 to 360 minutes is sufficient to achieve 100% mortality for this stage. Exposed early larval instar to -5ºC for 180 minutes is sufficient to achieve 100% mortality. Exposure of the late larval instars to 300 and/or 360 minutes is effective to achieve a complete mortality for the late larval instars of the pest. The calculated LT50 and LT95 were 113.73 and 208.64 minutes. Exposure of pupae to 300 minutes or more is effective to get a complete mortality for the pupal stage. High temperatures of 45º, 50º, 55º and 60ºC were tested against egg, late larval instars and pupal stages of E. cautella. Mortality tended to be increased with the increasing of temperature and exposure time. Exposure time for more than one hour at 45ºC, 15 minutes at 50ºC and 10 minutes at 55ºC were more effective and led to more than 95% mortality for the egg stage of E. cautella. Exposure of the late larval instars for more than 97.22, 72.17, 17.65 minutes at 45, 50 and 55ºC is sufficient to achieve more than 95% mortality for the late larval instars as indicated by LT95 values. Exposing the pupae to 25 minutes at high temperatures of 50ºC and to 15 minutes at 55ºC is an effective to get complete mortality for the pupal stage. Thus exposure times for more than 90 minutes at high temperature of 45ºC; 33 minutes at 50ºC and/or 11.67 minutes at 55ºC were more effective to achieve more than 95% mortality of the pupal stage of E. cautella.
Developing antibacterial peptides as a promising therapy for combating antibiotic-resistant Pseudomonas aeruginosa infections
Background and Aim: Antibiotic-resistant Pseudomonas aeruginosa poses a serious health threat. This study aimed to investigate the antibacterial activity of peptide KW-23 against drug-resistant P. aeruginosa and its potential for enhancing the efficacy of conventional antibiotics.
Materials and Methods: KW-23 was synthesized from nine amino acids, specifically three tryptophans and three lysines. The purity of the substance was analyzed using reverse-phase high-performance liquid chromatography. The peptide was identified through mass spectrometry using electrospray ionization. The minimum inhibitory concentration (MIC) values of KW-23 in combination with conventional antibiotics against control and multidrug-resistant P. aeruginosa were determined utilizing broth microdilution. The erythrocyte hemolytic assay was used to measure toxicity. The KW-23 effect was analyzed using the time-kill curve.
Results: The peptide exhibited strong antibacterial activity against control and multidrug-resistant strains of P. aeruginosa, with MICs of 4.5 μg/mL and 20 μg/mL, respectively. At higher concentration of 100 μg/mL, KW-23 exhibited a low hemolytic impact, causing no more than 3% damage to red blood. The cytotoxicity assay demonstrates KW-23’s safety, while the time-kill curve highlights its rapid and sustained antibacterial activity. The combination of KW-23 and gentamicin exhibited synergistic activity against both susceptible and resistant P. aeruginosa, with fractional inhibitory concentration index values of 0.07 and 0.27, respectively.
Conclusion: The KW-23 synthesized in the laboratory significantly combats antibiotic-resistant P. aeruginosa. Due to its strong antibacterial properties and low toxicity to cells, KW-23 is a promising alternative to traditional antibiotics in combating multidrug-resistant bacteria
A pilot study on ultrashort peptide with fluconazole: A promising novel anticandidal combination
Background and Aim: Human infections caused by Candida albicans are common and range in severity from relatively treatable skin and mucosal conditions to systemic, fatal invasive candidiasis. The treatment of fungal infections is challenged by major obstacles, including the scarcity of effective therapeutic options, the toxicity of available medications, and the escalating antifungal resistance. Hence, there exists an urgent need to develop new classes of antimicrobial agents. This study was conducted to investigate the effect of KW-23 peptide against standard and resistant strains of C. albicans alone and in combination with fluconazole.
Materials and Methods: A conjugated ultrashort antimicrobial peptide (KW-23) was designed and synthesized. KW-23 was challenged against standard and multidrug-resistant C. albicans alone and in combination with fluconazole using standard antimicrobial and checkerboard assays. The toxicity of the peptide was examined using hemolytic assays.
Results: KW-23 positively affected the standard and resistant Candidal strains (at 5 and 15 µg/mL respectively), exhibiting potent synergistic antimicrobial activity against the standard strain when combined with fluconazole. The effect of the combination was additive against the resistant strain (0.6 µg/mL). Furthermore, the peptide exhibited negligible toxicity on human erythrocytes.
Conclusion: KW-23 and its combination with fluconazole could be a promising candidate for developing anticandidal agents
واقع تطبيق حوكمة الموارد البشرية وفقا للمواصفة العالمية -30408ISO في شركة مسقط لتوزيع الكهرباء - حالة دراسية
هدف المقال التعرف إلى واقع تطبيق حوكمة الموارد البشرية وفقا للمواصفة العالمية -30408ISO وقد طبقت في شركة مسقط لتوزيع الكهرباء وشملت جميع العاملين في الشركة المذكورة وبلغ عددهم )497( فردا. واستخدمت االستبانة وسيلة لجمع البيانات والمعلومات وكانت اهم نتائج الدراسة ان مستوى تطبيق حوكمة الموارد البشرية في الشركة المذكورة كان )متوسطا( وقدمت الدراسة مجموعة من التوصيات أهمها: محافظة شركة مسقط لتوزيع الكهرباء
على استمرارية االهتمام بتطبيق حوكمة الموارد البشرية بمختلف أبعادها واستخدام أدوات تضمن عدم تراجع أو تدني مستوى االهتمام بها، كتحقيق العدالة في التعامل مع الموظفين، ووضع أسس عادلة وواضحة وشفافة فيما يتعلق بنظام الترقيات والحوافز
Temperature Dependence of GaN HEMT Small Signal Parameters
This study presents the temperature dependence of small signal parameters of GaN/SiC HEMTs across the 0–150°C range. The changes with temperature for transconductance (m), output impedance (ds and ds), feedback capacitance (dg), input capacitance (gs), and gate resistance (g) are measured. The variations with temperature are established for m, ds, ds, dg, gs, and g in the GaN technology. This information is useful for MMIC designs
Kinetin Ameliorates Cisplatin‐Induced Hepatotoxicity and Lymphotoxicity via Attenuating Oxidative Damage, Cell Apoptosis and Inflammation in Rats
Though several previous studies reported the in vitro and in vivo antioxidant effect of kinetin (Kn), details on its action in cisplatin‐induced toxicity are still scarce. In this study we eval-uated, for the first time, the effects of kinetin in cisplatin (cp)‐ induced liver and lymphocyte toxicity in rats. Wistar male albino rats were divided into nine groups: (i) the control (C), (ii) groups 2,3 and 4, which received 0.25, 0.5 and 1 mg/kg kinetin for 10 days; (iii) the cisplatin (cp) group, which received a single intraperitoneal injection of CP (7.0 mg/kg); and (iv) groups 6, 7, 8 and 9, which received, for 10 days, 0.25, 0.5 and 1 mg/kg kinetin or 200 mg/kg vitamin C, respectively, and Cp on the fourth day. CP‐injected rats showed a significant impairment in biochemical, oxidative stress and inflammatory parameters in hepatic tissue and lymphocytes. PCR showed a profound increase in caspase‐3, and a significant decline in AKT gene expression. Intriguingly, Kn treatment restored the biochemical, redox status and inflammatory parameters. Hepatic AKT and caspase‐3 expression as well as CD95 levels in lymphocytes were also restored. In conclusion, Kn mitigated oxidative imbalance, inflammation and apoptosis in CP‐induced liver and lymphocyte toxicity; therefore, it can be considered as a promising therapy
Realistic smile expression recognition approach using ensemble classifier with enhanced bagging
A robust smile recognition system could be widely used for many real-world applications. Classification of a facial smile in an unconstrained setting is difficult due to the invertible and wide variety in face images. In this paper, an adaptive model for smile expression classification is suggested that integrates a fast features extraction algorithm and cascade classifiers. Our model takes advantage of the intrinsic association between face detection, smile, and other face features to alleviate the over-fitting issue on the limited
training set and increase classification results. The features are extracted taking into account to exclude any unnecessary coefficients in the feature vector; thereby enhancing the discriminatory capacity of the extracted features and
reducing the computational process. Still, the main causes of error in learning are due to noise, bias, and variance. Ensemble helps to minimize these factors. Combinations of multiple classifiers decrease variance, especially in the case
of unstable classifiers, and may produce a more reliable classification than a single classifier. However, a shortcoming of bagging as the best ensemble classifier is its random selection, where the classification performance relies on the chance to pick an appropriate subset of training items. The suggested model employs a modified form of bagging while creating training sets to deal with this challenge (error-based bootstrapping). The experimental results for smile classification on the JAFFE, CK+, and CK+48 benchmark datasets show the feasibility of our proposed model
Impact of salicylic acid, abscisic acid, and methyl jamonate on postharvest quality and bioactive compounds of cultivated strawberry fruit
BACKGROUND:
Strawberry is one of the most highly consumed fruits worldwide. However, it is highly a perishable fruit postharvest.
OBJECTIVE:
To assess the effect of dipping strawberry fruits after harvest in plant growth regulators to maintain postharvest quality.
METHODS:
Treatments tested were: 2 and 4 mM salicylic acid (SA), 0.25 and 0.50 mM abscisic acid (ABA) and methyl jasmonate at 0.25 and 0.50 mM (MeJA). Bioactive compounds and fungal growth were assessed over 12 days of storage at 4°C.
RESULTS:
Both concentrations of SA and MeJA significantly suppressed weight loss, decay and respiration rate and 0.50 mM ABA also reduced decay. Both concentrations of SA retarded color development, and total soluble solids content was enhanced by 0.50 mM ABA and MeJA treatments. The most effective treatments for preserving firmness were 0.25 mM MeJA and 4 mM SA. Reduction in loss of ascorbic acid and bioactive compounds during storage was achieved using the highest concentrations of SA, ABA, and MeJA. Fungal growth was suppressed by all treatments but the best treatment was MeJA at both concentrations.
CONCLUSIONS:
All three plant growth regulators reduce postharvest changes in strawberry but effects differ amongst the treatments
Nurses experience of caring for patients with COVID-19 : a phenomenological study
Introduction: COVID-19 has impacted all dimensions of life and imposed serious threat on humankind. Background: In Jordan, understanding how nurses experienced providing care for patients with COVID-19 offers a framework of knowledge about similar situations within the context of Arabic culture. Aim: To explore nurses' experience with providing hands-on care to patients with active COVID-19 infection in an Arabic society. Methods: A descriptive phenomenological study interviewed 10 nurses through a purposive sampling approach until data saturation was reached. The research site was hospital designated to receive patients with active COVID-19 infection. Semi-structured interviews were used to collect the data. Findings: Three themes were generated from the data: the impact of the COVID-19 outbreak on nurses' health; unfamiliar work and social environments; and conforming to professional standards. Discussion: There are specific risks to the physical and mental wellbeing of nurses who provide hands-on care to patients with COVID-19 in an Arabic society. Implication for nursing and health policy: Health care institutions should consider establishing programs that promote nurses' wellbeing and support their productivity in a crisis. A danger pay allowance should be considered for nurses during extraordinary circumstances, such as pandemics
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