An efficient chameleon swarm algorithm for economic load dispatch problem

Economic Load Dispatch (ELD) is a complicated and demanding problem for power engineers. ELD relates to the minimization of the economic cost of production, thereby allocating the produced power by each unit in the most possible economic manner. In recent years, emphasis has been laid on minimization of emissions, in addition to cost, resulting in the Combined Economic and Emission Dispatch (CEED) problem. The solutions of the ELD and CEED problems are mostly dominated by metaheuristics. The performance of the Chameleon Swarm Algorithm (CSA) for solving the ELD problem was tested in this work. CSA mimics the hunting and food searching mechanism of chameleons. This algorithm takes into account the dynamics of food hunting of the chameleon on trees, deserts, and near swamps. The performance of the aforementioned algorithm was compared with a number of advanced algorithms in solving the ELD and CEED problems, such as Sine Cosine Algorithm (SCA), Grey Wolf Optimization (GWO), and Earth Worm Algorithm (EWA). The simulated results established the efficacy of the proposed CSA algorithm. The power mismatch factor is the main item in ELD problems. The best value of this factor must tend to nearly zero. The CSA algorithm achieves the best power mismatch values of 3.16×10−13, 4.16×10−12 and 1.28×10−12 for demand loads of 700, 1000, and 1200 MW, respectively, of the ELD problem. The CSA algorithm achieves the best power mismatch values of 6.41×10−13 , 8.92×10−13 and 1.68×10−12 for demand loads of 700, 1000, and 1200 MW, respectively, of the CEED problem. Thus, the CSA algorithm was found to be superior to the algorithms compared in this work

A brief investigation on the prospective of co-composted biochar as a fertilizer for Zucchini plants cultivated in arid sandy soil

Compost is commonly utilized to improve properties of infertile sandy soils, despite its high biodegradability which may increase greenhouse gases emissions. It is possible to combine compost with biochar, which degrades at a slower rate, forming a “co-composted biochar” product. This mixture could enhance plant growth parameters beyond those attained for using each component, individually. To investigate this assumption, zucchini was selected as a test plant to be grown, under greenhouse conditions, on a sandy soil that received biochar, compost or co-composted biochar (from rice straw or sugarcane bagasse (SB)) for a duration of 15 days. This timeframe was deemed sufficient to achieve a relatively stable degradation rate for compost. Application of organic materials increased both fresh and dry weights of zucchini plants, particularly when co-composted biochar of SB was used. Specifically, plant fresh weights increased by 1.24–1.71 folds when using this additive versus the control group. Additionally, availability of nitrogen, phosphorus, and potassium in soil and their uptake by plants significantly increased owing to application of all additives, with superiority for the co-composted biochar of SB. Enhancements in plant fresh weights were strongly correlated with increasing availability and uptake of phosphorus by plants. In conclusion, organic amendments have a substantial positive impact on enhancing the nutritional status and growth of zucchini, even during the early vegetative growth stage (within the first 15 days after planting). The greatest improvements were observed when co-composted biochar of SB was used and this confirm the main hypothesis of the study

Relationship between fiber cotton grade and some related characteristics of long and extra-long staple Egyptian cotton varieties (Gossypium barbadense. L)

The materials used in this study were four commercial varieties of Egyptian cotton; two (Giza 86 and Giza 90) belonging to the long staple class and the others (Giza 88 and Giza 92) belonging to the extra-long staple category. Within each variety, nine lint cotton grades namely: Fully Good (FG), Good/Fully Good (G/FG), Good (G), Fully Good Fair/Good (FGF/G), Fully Good Fair (FGF), Good Fair/ Fully Good Fair (GF/FGF), Good Fair (GF), Fully Fair/Good Fair (FF/GF) and Fully Fair (FF) were used. Thus Fully Good (FG) is the top quality grade and the others are progressively lower; i.e. Fully Fair (FF) is the lowest grade. Fiber properties were measured by using the Cotton Classifying System Version-5 instrument (CCS-V5). Data collected for the following characteristics were: reflectance degree (Rd %), yellowness degree (+b), trash%, dust%, fiber fragments%, total trash%, No. of neps and Micronaire value. Mean squares due to all nine grades of long and extra-long staple cotton varieties in combined analysis were highly significant over seasons for all studied characters except yellowness (+b) and fiber fragments% in Giza 92. Highly significant mean performance values of four cotton varieties and nine lint grades for each variety for all studied characters, it became clear that there were significant genetically differences between studied varieties and fiber cotton lint grades within each variety. Gradually increased for yellowness degree, trash%, dust%, fiber fragments%, total trash% (trash, dust, fiber fragments) and number of neps, while gradually decreased for reflectance degree (Rd%) and micronaire value with significant level as transfer for all tested varieties from (FG) grade down to the (FF). All studied varieties showed highly significant negative correlation between fiber cotton grade with yellowness, trash, dust, total trash% and No. of neps, while highly significant positive correlation between fiber cotton grade with reflectance degree and micronaire value. Total trash% and micronaire value as well as reflectance degree and their interactions were the most contributing and influencing of fiber cotton grades. Also these properties and their joint effects are prevailing factors which affect the personal judgment of the grader at evaluating the cotton grade

Global economic burden of unmet surgical need for appendicitis

Background: There is a substantial gap in provision of adequate surgical care in many low-and middle-income countries. This study aimed to identify the economic burden of unmet surgical need for the common condition of appendicitis. Methods: Data on the incidence of appendicitis from 170 countries and two different approaches were used to estimate numbers of patients who do not receive surgery: as a fixed proportion of the total unmet surgical need per country (approach 1); and based on country income status (approach 2). Indirect costs with current levels of access and local quality, and those if quality were at the standards of high-income countries, were estimated. A human capital approach was applied, focusing on the economic burden resulting from premature death and absenteeism. Results: Excess mortality was 4185 per 100 000 cases of appendicitis using approach 1 and 3448 per 100 000 using approach 2. The economic burden of continuing current levels of access and local quality was US $92 492 million using approach 1 and$73 141 million using approach 2. The economic burden of not providing surgical care to the standards of high-income countries was $95 004 million using approach 1 and$75 666 million using approach 2. The largest share of these costs resulted from premature death (97.7 per cent) and lack of access (97.0 per cent) in contrast to lack of quality. Conclusion: For a comparatively non-complex emergency condition such as appendicitis, increasing access to care should be prioritized. Although improving quality of care should not be neglected, increasing provision of care at current standards could reduce societal costs substantially

Laparoscopy in management of appendicitis in high-, middle-, and low-income countries: a multicenter, prospective, cohort study.

BACKGROUND: Appendicitis is the most common abdominal surgical emergency worldwide. Differences between high- and low-income settings in the availability of laparoscopic appendectomy, alternative management choices, and outcomes are poorly described. The aim was to identify variation in surgical management and outcomes of appendicitis within low-, middle-, and high-Human Development Index (HDI) countries worldwide. METHODS: This is a multicenter, international prospective cohort study. Consecutive sampling of patients undergoing emergency appendectomy over 6 months was conducted. Follow-up lasted 30 days. RESULTS: 4546 patients from 52 countries underwent appendectomy (2499 high-, 1540 middle-, and 507 low-HDI groups). Surgical site infection (SSI) rates were higher in low-HDI (OR 2.57, 95% CI 1.33-4.99, p = 0.005) but not middle-HDI countries (OR 1.38, 95% CI 0.76-2.52, p = 0.291), compared with high-HDI countries after adjustment. A laparoscopic approach was common in high-HDI countries (1693/2499, 67.7%), but infrequent in low-HDI (41/507, 8.1%) and middle-HDI (132/1540, 8.6%) groups. After accounting for case-mix, laparoscopy was still associated with fewer overall complications (OR 0.55, 95% CI 0.42-0.71, p < 0.001) and SSIs (OR 0.22, 95% CI 0.14-0.33, p < 0.001). In propensity-score matched groups within low-/middle-HDI countries, laparoscopy was still associated with fewer overall complications (OR 0.23 95% CI 0.11-0.44) and SSI (OR 0.21 95% CI 0.09-0.45). CONCLUSION: A laparoscopic approach is associated with better outcomes and availability appears to differ by country HDI. Despite the profound clinical, operational, and financial barriers to its widespread introduction, laparoscopy could significantly improve outcomes for patients in low-resource environments. TRIAL REGISTRATION: NCT02179112

Pooled analysis of WHO Surgical Safety Checklist use and mortality after emergency laparotomy

Background The World Health Organization (WHO) Surgical Safety Checklist has fostered safe practice for 10 years, yet its place in emergency surgery has not been assessed on a global scale. The aim of this study was to evaluate reported checklist use in emergency settings and examine the relationship with perioperative mortality in patients who had emergency laparotomy. Methods In two multinational cohort studies, adults undergoing emergency laparotomy were compared with those having elective gastrointestinal surgery. Relationships between reported checklist use and mortality were determined using multivariable logistic regression and bootstrapped simulation. Results Of 12 296 patients included from 76 countries, 4843 underwent emergency laparotomy. After adjusting for patient and disease factors, checklist use before emergency laparotomy was more common in countries with a high Human Development Index (HDI) (2455 of 2741, 89.6 per cent) compared with that in countries with a middle (753 of 1242, 60.6 per cent; odds ratio (OR) 0.17, 95 per cent c.i. 0.14 to 0.21, P <0001) or low (363 of 860, 422 per cent; OR 008, 007 to 010, P <0.001) HDI. Checklist use was less common in elective surgery than for emergency laparotomy in high-HDI countries (risk difference -94 (95 per cent c.i. -11.9 to -6.9) per cent; P <0001), but the relationship was reversed in low-HDI countries (+121 (+7.0 to +173) per cent; P <0001). In multivariable models, checklist use was associated with a lower 30-day perioperative mortality (OR 0.60, 0.50 to 073; P <0.001). The greatest absolute benefit was seen for emergency surgery in low- and middle-HDI countries. Conclusion Checklist use in emergency laparotomy was associated with a significantly lower perioperative mortality rate. Checklist use in low-HDI countries was half that in high-HDI countries.Peer reviewe

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)

Global variation in anastomosis and end colostomy formation following left-sided colorectal resection

Background End colostomy rates following colorectal resection vary across institutions in high-income settings, being influenced by patient, disease, surgeon and system factors. This study aimed to assess global variation in end colostomy rates after left-sided colorectal resection. Methods This study comprised an analysis of GlobalSurg-1 and -2 international, prospective, observational cohort studies (2014, 2016), including consecutive adult patients undergoing elective or emergency left-sided colorectal resection within discrete 2-week windows. Countries were grouped into high-, middle- and low-income tertiles according to the United Nations Human Development Index (HDI). Factors associated with colostomy formation versus primary anastomosis were explored using a multilevel, multivariable logistic regression model. Results In total, 1635 patients from 242 hospitals in 57 countries undergoing left-sided colorectal resection were included: 113 (6·9 per cent) from low-HDI, 254 (15·5 per cent) from middle-HDI and 1268 (77·6 per cent) from high-HDI countries. There was a higher proportion of patients with perforated disease (57·5, 40·9 and 35·4 per cent; P < 0·001) and subsequent use of end colostomy (52·2, 24·8 and 18·9 per cent; P < 0·001) in low- compared with middle- and high-HDI settings. The association with colostomy use in low-HDI settings persisted (odds ratio (OR) 3·20, 95 per cent c.i. 1·35 to 7·57; P = 0·008) after risk adjustment for malignant disease (OR 2·34, 1·65 to 3·32; P < 0·001), emergency surgery (OR 4·08, 2·73 to 6·10; P < 0·001), time to operation at least 48 h (OR 1·99, 1·28 to 3·09; P = 0·002) and disease perforation (OR 4·00, 2·81 to 5·69; P < 0·001). Conclusion Global differences existed in the proportion of patients receiving end stomas after left-sided colorectal resection based on income, which went beyond case mix alone

EFFECT OF SPLIT PACKING METHOD ON RETENTION OF MAXILLARY COMPLETE DENTURE (IN VIVO AND IN VITRO STUDY)

The dimensional change of maxillary complete dentures remains a problem that may affect retention. The problem is multi-factorial and cannot be totally eliminated. Several methods were proposed to control these changes in order to keep them as minimum as possible. In the present study, a complete split packing method was investigated. The aim was to evaluate the retention of the obtained dentures clinically. 10 edentulous patients were selected; each received 2 heat cured acrylic maxillary dentures that were identical in every aspect except packing method. One maxillary denture was conventionally cured and the other was cured as two split halves that were reassembled by self cure resin. The dentures were examined for retention using a digital force gauge. The results favored the split method, so the second phase of the study was conducted. The aim of the second phase was to evaluate the accuracy of fit at the posterior palatal seal area in vitro using travelling microscope. 10 identical maxillary casts were obtained from a rubber mould. The casts were randomly divided into two groups. Identical maxillary dentures were constructed over these casts. The dentures constructed for the first group casts were split packed, while those for the second group were conventionally packed. The discrepancies at the posterior palatal seal area revealed for group I were significantly less than group II. The clinical and in vitro results suggests that the split packing method of acrylic dentures produces better maxillary denture in terms of posterior palatal seal discrepancies and clinical retention