Determination of Seroprevalence of Contagious Caprine Pleuropneumonia and Associated Risk Factors in Goats and Sheep Using Classification and Regression Tree

Classification and Regression Tree (CART) analysis is a potentially powerful tool for identifying risk factors associated with contagious caprine pleuropneumonia (CCPP) and the important interactions between them. Our objective was therefore to determine the seroprevalence and identify the risk factors associated with CCPP using CART data mining modeling in the most densely sheep- and goat-populated governorates. A cross-sectional study was conducted on 620 animals (390 sheep, 230 goats) distributed over four governorates in the Nile Delta of Egypt in 2019. The randomly selected sheep and goats from different geographical study areas were serologically tested for CCPP, and the animals’ information was obtained from flock men and farm owners. Six variables (geographic location, species, flock size, age, gender, and communal feeding and watering) were used for risk analysis. Multiple stepwise logistic regression and CART modeling were used for data analysis. A total of 124 (20%) serum samples were serologically positive for CCPP. The highest prevalence of CCPP was between aged animals (>4 y; 48.7%) raised in a flock size ≥200 (100%) having communal feeding and watering (28.2%). Based on logistic regression modeling (area under the curve, AUC = 0.89; 95% CI 0.86 to 0.91), communal feeding and watering showed the highest prevalence odds ratios (POR) of CCPP (POR = 3.7, 95% CI 1.9 to 7.3), followed by age (POR = 2.1, 95% CI 1.6 to 2.8) and flock size (POR = 1.1, 95% CI 1.0 to 1.2). However, higher-accuracy CART modeling (AUC = 0.92, 95% CI 0.90 to 0.95) showed that a flock size >100 animals is the most important risk factor (importance score = 8.9), followed by age >4 y (5.3) followed by communal feeding and watering (3.1). Our results strongly suggest that the CCPP is most likely to be found in animals raised in a flock size >100 animals and with age >4 y having communal feeding and watering. Additionally, sheep seem to have an important role in the CCPP epidemiology. The CART data mining modeling showed better accuracy than the traditional logistic regression.

Caries-Preventive Effect of Salt Fluoridation in Preschool Children in The Gambia: A Prospective, Controlled, Interventional Study

The aim of this study was to investigate the anticaries effect of fluoridated salt in a communal feeding program for preschool children. In the Gambian city of Brikama, drinking water had a low fluoride content (0.1 mg F-/L) and young children did not use toothpaste for oral hygiene. Its 2 preschools served as clusters for the trial. Random allocation of the kindergartens was performed by one person not involved in the study, and the clinical examinations were carried out using the envelope method. Meals were prepared with fluoridated salt (250 mg F-/kg salt) in the intervention group but not in the control group. According to the inclusion criteria (complete primary dentition and informed consent from legal guardian), 441 children aged 3-5 years were enrolled. The children were examined by calibrated persons according to WHO criteria, allowing the calculation of d3mft scores. The primary end point was the mean difference in the incidence of caries cavities (Δd3/4mft) after 12 months. After 12 months, the mean caries incidence per person was 1.29 d3/4mf teeth (95% CI: 0.96; 1.62) in the test group (n = 304 children) and 3.83 d3/4mf teeth (95% CI: 2.94; 4.72) in the control group (n = 137 children). Thus, the caries-prevented fraction was 66.3%. No signs of harm due to the intervention were observed. The use of fluoridated salt in a communal feeding program and in an environment with negligible availability of fluoride from other sources yields a considerable caries-preventive effect.

Letter to the British Medical Journal

In this letter to the British Medical Journal on communal feeding in schools, Winnicott stresses the importance to the family of the emotional side of meals cooked and eaten together at home.

Extended maternal care and offspring interactions in the subsocial Australian crab spider, Xysticus bimaculatus

Extended maternal care is considered a prerequisite for the evolution of permanent family grouping and eusociality in invertebrates. In spiders, the essential evolutionary transitions to permanent sociality along this ‘subsocial route’ include the extension of care beyond hatching, the persistence of offspring groups to maturation and the elimination of premating dispersal. Subsocial Australian crab spiders (Thomisidae) present a suitable system to identify the selective agents prolonging group cohesion. Particularly, the recent discovery of independently evolved subsociality in the thomisid Xysticus bimaculatus provides new potential for comparative studies to expand the limited understanding of group cohesion beyond the offspring’s potential independence and despite socially exploitative behaviour. Providing fundamental knowledge, the present study investigated maternal care and offspring interactions in X. bimaculatus for the first time. Nest dissections revealed that mothers produce exceptionally small clutches, potentially reflecting a limit in the number of juveniles they can successfully care for. A laboratory experiment demonstrated crucial benefits for offspring in receiving maternal care beyond nutritional independence, mediated by extensive maternal food provisioning. However, prey-sharing also occurred between juveniles irrespective of maternal presence, which marks this species’ predisposition for exploitative feeding behaviour. I therefore suggest X. bimaculatus as a suitable model for investigating the regulation of communal feeding in group-living spiders.

Variable participation in the defense of communal feeding territories by blue monkeys in the Kakamega Forest, Kenya

While blue monkey groups often defend feeding territories against their neighbours, group members do not participate equally. Data spanning 5 years and 5 wild groups were used to address factors that might explain variable participation, both across age-sex classes and among individual adult females. Adult females participated most, although there was a 9-fold difference between those individuals who participated most and least. Juvenile participation increased with age, but female juveniles participated more than males in each cohort. Male juveniles reduced participation as they approached the age of natal emigration. In general, it seems that adult participation patterns are acquired gradually during ontogeny. Among adult females, those with infants participated less than those without infants, and higher-ranking females participated more than lower-rankers. The presence of matrilineal kin in the group did not generally affect participation by adult females. Age-sex class differences and the effect of infant presence can be explained in terms of relative costs and benefits to participation. The lack of a kinship effect was unexpected. The rank effect was also unanticipated, given that rank does not predict reproductive success in this species. High-ranking females may face lower costs, offer staying incentives to lower-ranked females, or trade services with them.