Classification of Aedes Adults Mosquitoes in Two Distinct Groups Based on Fisher Linear Discriminant Analysis and FZOARO Techniques

This paper describes the breeding, feeding and measurement of Aedes mosquitoes based on body size (wing length). Due to similarity in body size measurements, we were constrained on gender recognition. To reveal the gender identity of these mosquitoes, Fisher linear discriminant analysis and FZOARO classification models were considered suitable for prediction and classification.   We randomly selected 15 mosquitoes from each groups and categorize the body size as small and large and applied the classification procedures. Both classification techniques perform similar. The numerical simulation reveals that 86.67% were classified as male for group one and 80% were correctly classified as female in group two. Keywords: Fisher linear discriminant analysis; FZOARO; Classification

Classification of Aedes Adults Mosquitoes in Two Distinct Groups Based on Fisher Linear Discriminant Analysis and FZOARO Techniques

This paper describes the breeding, feeding and measurement of Aedes mosquitoes based on body size (wing length). Due to similarity in body size measurements, we were constrained on gender recognition. To reveal the gender identity of these mosquitoes, Fisher linear discriminant analysis and FZOARO classification models were considered suitable for prediction and classification.   We randomly selected 15 mosquitoes from each groups and categorize the body size as small and large and applied the classification procedures. Both classification techniques perform similar. The numerical simulation reveals that 86.67% were classified as male for group one and 80% were correctly classified as female in group two.   Keywords: Fisher linear discriminant analysis; FZOARO; Classification

Intraperitoneal drain placement and outcomes after elective colorectal surgery: international matched, prospective, cohort study

Despite current guidelines, intraperitoneal drain placement after elective colorectal surgery remains widespread. Drains were not associated with earlier detection of intraperitoneal collections, but were associated with prolonged hospital stay and increased risk of surgical-site infections.Background Many surgeons routinely place intraperitoneal drains after elective colorectal surgery. However, enhanced recovery after surgery guidelines recommend against their routine use owing to a lack of clear clinical benefit. This study aimed to describe international variation in intraperitoneal drain placement and the safety of this practice. Methods COMPASS (COMPlicAted intra-abdominal collectionS after colorectal Surgery) was a prospective, international, cohort study which enrolled consecutive adults undergoing elective colorectal surgery (February to March 2020). The primary outcome was the rate of intraperitoneal drain placement. Secondary outcomes included: rate and time to diagnosis of postoperative intraperitoneal collections; rate of surgical site infections (SSIs); time to discharge; and 30-day major postoperative complications (Clavien-Dindo grade at least III). After propensity score matching, multivariable logistic regression and Cox proportional hazards regression were used to estimate the independent association of the secondary outcomes with drain placement. Results Overall, 1805 patients from 22 countries were included (798 women, 44.2 per cent; median age 67.0 years). The drain insertion rate was 51.9 per cent (937 patients). After matching, drains were not associated with reduced rates (odds ratio (OR) 1.33, 95 per cent c.i. 0.79 to 2.23; P = 0.287) or earlier detection (hazard ratio (HR) 0.87, 0.33 to 2.31; P = 0.780) of collections. Although not associated with worse major postoperative complications (OR 1.09, 0.68 to 1.75; P = 0.709), drains were associated with delayed hospital discharge (HR 0.58, 0.52 to 0.66; P < 0.001) and an increased risk of SSIs (OR 2.47, 1.50 to 4.05; P < 0.001). Conclusion Intraperitoneal drain placement after elective colorectal surgery is not associated with earlier detection of postoperative collections, but prolongs hospital stay and increases SSI risk

Classification of Aedes Adults Mosquitoes in Two Distinct Groups Based on Fisher Linear Discriminant Analysis and FZOARO Techniques

This paper describes the breeding, feeding and measurement of Aedes mosquitoes based on body size (wing length). Due to similarity in body size measurements, we were constrained on gender recognition. To reveal the gender identity of these mosquitoes, Fisher linear discriminant analysis and FZOARO classification models were considered suitable for prediction and classification. We randomly selected 15 mosquitoes from each groups and categorize the body size as small and large and applied the classification procedures. Both classification techniques perform similar. The numerical simulation reveals that 86.67% were classified as male for group one and 80% were correctly classified as female in group two

Changes in the biting activity of a dengue vector relative to larval and adult nutritional histories : implications for preventive measures

The magnitude of dengue transmission depends largely on the level of human–vector contact. Therefore, knowledge regarding the biting periodicity of mosquitoes is crucial to determine transmission periods' risk, and in planning personal protection measures. Dengue vectors are day-active and endure transitory periods of starvation overnight. However, it is unclear how their blood feeding activity pattern is related to body size when temporarily deprived of their main source of energy — sugar. We examined the changes in Aedes albopictus diurnal biting activity, taking into account larval nutritional history and adult starvation. Overall, large body size and non-starvation conditions were associated with better blood feeding success, but these parameters did not significantly modify the timing of first blood feeding attempt. Females of both sizes showed significant temporal variations in their blood feeding activities. Under conditions of starvation, blood meal uptake was much greater in large females from morning to evening. Similar variations of feeding activity were observed in small females, except in the morning. Under non-starvation conditions, the blood feeding activity of small mosquitoes tended to decrease over time, whereas blood meal uptake activity was high and remained almost constant from morning to evening for larger mosquitoes. This work emphasizes the importance of body size and hunger on the dynamics of vector–host interaction and has important implications for the development of novel strategies for the prevention of disease transmission. Knowing when dengue vectors actively bite during the day can help in timing effective personal protective measures

Effect of COVID-19 pandemic lockdowns on planned cancer surgery for 15 tumour types in 61 countries: an international, prospective, cohort study

Background: Surgery is the main modality of cure for solid cancers and was prioritised to continue during COVID-19 outbreaks. This study aimed to identify immediate areas for system strengthening by comparing the delivery of elective cancer surgery during the COVID-19 pandemic in periods of lockdown versus light restriction. Methods: This international, prospective, cohort study enrolled 20 006 adult (≥18 years) patients from 466 hospitals in 61 countries with 15 cancer types, who had a decision for curative surgery during the COVID-19 pandemic and were followed up until the point of surgery or cessation of follow-up (Aug 31, 2020). Average national Oxford COVID-19 Stringency Index scores were calculated to define the government response to COVID-19 for each patient for the period they awaited surgery, and classified into light restrictions (index <20), moderate lockdowns (20–60), and full lockdowns (>60). The primary outcome was the non-operation rate (defined as the proportion of patients who did not undergo planned surgery). Cox proportional-hazards regression models were used to explore the associations between lockdowns and non-operation. Intervals from diagnosis to surgery were compared across COVID-19 government response index groups. This study was registered at ClinicalTrials.gov, NCT04384926. Findings: Of eligible patients awaiting surgery, 2003 (10·0%) of 20 006 did not receive surgery after a median follow-up of 23 weeks (IQR 16–30), all of whom had a COVID-19-related reason given for non-operation. Light restrictions were associated with a 0·6% non-operation rate (26 of 4521), moderate lockdowns with a 5·5% rate (201 of 3646; adjusted hazard ratio [HR] 0·81, 95% CI 0·77–0·84; p<0·0001), and full lockdowns with a 15·0% rate (1775 of 11 827; HR 0·51, 0·50–0·53; p<0·0001). In sensitivity analyses, including adjustment for SARS-CoV-2 case notification rates, moderate lockdowns (HR 0·84, 95% CI 0·80–0·88; p<0·001), and full lockdowns (0·57, 0·54–0·60; p<0·001), remained independently associated with non-operation. Surgery beyond 12 weeks from diagnosis in patients without neoadjuvant therapy increased during lockdowns (374 [9·1%] of 4521 in light restrictions, 317 [10·4%] of 3646 in moderate lockdowns, 2001 [23·8%] of 11 827 in full lockdowns), although there were no differences in resectability rates observed with longer delays. Interpretation: Cancer surgery systems worldwide were fragile to lockdowns, with one in seven patients who were in regions with full lockdowns not undergoing planned surgery and experiencing longer preoperative delays. Although short-term oncological outcomes were not compromised in those selected for surgery, delays and non-operations might lead to long-term reductions in survival. During current and future periods of societal restriction, the resilience of elective surgery systems requires strengthening, which might include protected elective surgical pathways and long-term investment in surge capacity for acute care during public health emergencies to protect elective staff and services. Funding: National Institute for Health Research Global Health Research Unit, Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, Medtronic, Sarcoma UK, The Urology Foundation, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Intraperitoneal drain placement and outcomes after elective colorectal surgery: international matched, prospective, cohort study

Many surgeons routinely place intraperitoneal drains after elective colorectal surgery. However, enhanced recovery after surgery guidelines recommend against their routine use owing to a lack of clear clinical benefit. This study aimed to describe international variation in intraperitoneal drain placement and the safety of this practice

Safety and efficacy of intraperitoneal drain placement after emergency colorectal surgery. An international, prospective cohort study

Intraperitoneal drains are often placed during emergency colorectal surgery. However, there is a lack of evidence supporting their use. This study aimed to describe the efficacy and safety of intraperitoneal drain placement after emergency colorectal surgery. Method: COMPlicAted intra-abdominal collectionS after colorectal Surgery (COMPASS) is a prospective, international, cohort study into which consecutive adult patients undergoing emergency colorectal surgery were enrolled (from 3 February 2020 to 8 March 2020). The primary outcome was the rate of intraperitoneal drain placement. Secondary outcomes included rate and time-to-diagnosis of postoperative intraperitoneal collections, rate of surgical site infections (SSIs), time to discharge and 30-day major postoperative complications (Clavien-Dindo III-V). Multivariable logistic and Cox proportional hazards regressions were used to estimate the independent association of the outcomes with drain placement. Results: Some 725 patients (median age 68.0 years; 349 [48.1%] women) from 22 countries were included. The drain insertion rate was 53.7% (389 patients). Following multivariable adjustment, drains were not significantly associated with reduced rates (odds ratio [OR] = 1.56, 95% CI: 0.48-5.02, p = 0.457) or earlier detection (hazard ratio [HR] = 1.07, 95% CI: 0.61-1.90, p = 0.805) of collections. Drains were not significantly associated with worse major postoperative complications (OR = 1.26, 95% CI: 0.67-2.36, p = 0.478), delayed hospital discharge (HR = 1.11, 95% CI: 0.91-1.36, p = 0.303) or increased risk of SSIs (OR = 1.61, 95% CI: 0.87-2.99, p = 0.128). Conclusion: This is the first study investigating placement of intraperitoneal drains following emergency colorectal surgery. The safety and clinical benefit of drains remain uncertain. Equipoise exists for randomized trials to define the safety and efficacy of drains in emergency colorectal surgery