‘Outbreak Gold Standard’Selection to Provide Optimized Threshold for Infectious Diseases Early-alert Based on China Infectious Disease Automated-alert and Response System

The China Infectious Disease Automated-alert and Response System（CIDARS） was successfully implemented and became operational nationwide in 2008. The CIDARS plays an important role in and has been integrated into the routine outbreak monitoring efforts of the Center for Disease Control（CDC） at all levels in China. In the CIDARS, thresholds are determined using the ？Mean＋2SD？ in the early stage which have limitations. This study compared the performance of optimized thresholds defined using the ？Mean ＋2SD？ method to the performance of 5 novel algorithms to select optimal ？Outbreak Gold Standard（OGS）？ and corresponding thresholds for outbreak detection. Data for infectious disease were organized by calendar week and year. The ？Mean＋2 SD？, C1, C2, moving average（MA）, seasonal model（SM）, and cumulative sum（CUSUM） algorithms were applied. Outbreak signals for the predicted value（Px） were calculated using a percentile-based moving window. When the outbreak signals generated by an algorithm were in line with a Px generated outbreak signal for each week, this Px was then defined as the optimized threshold for that algorithm. In this study, six infectious diseases were selected and classified into TYPE A（chickenpox and mumps）, TYPE B（influenza and rubella） and TYPE C [hand foot and mouth disease（HFMD） and scarlet fever]. Optimized thresholds for chickenpox（P_（55））, mumps（P_（50））, influenza（P_（40）, P_（55）, and P_（75））, rubella（P_（45） and P_（75））, HFMD（P_（65） and P_（70））, and scarlet fever（P_（75） and P_（80）） were identified. The C1, C2, CUSUM, SM, and MA algorithms were appropriate for TYPE A. All 6 algorithms were appropriate for TYPE B. C1 and CUSUM algorithms were appropriate for TYPE C. It is critical to incorporate more flexible algorithms as OGS into the CIDRAS and to identify the proper OGS and corresponding recommended optimized threshold by different infectious disease types.

Gustatory responsiveness in Vespula germanica workers:exploring the interplay between sensory perception and task specialization

Workers'task specialization and division of labor are critical features of social insects'ecological success.It has been proposed that the division of labor relies on response threshold models:individuals varying their sensitivity(and responsiveness)to biologically relevant stimuli and performing a specific task when a stimulus exceeds an internal threshold.In this work,we study carbohydrate and protein responsiveness and their relation to worker task specialization in Vespula germanica,an invasive social wasp.The sucrose and peptone responsiveness of two different subcastes,preforagers and foragers,was determined by stimulating the antenna of the wasps with increasing concentrations of the solution and quantifying whether each concentration elicited a licking response.We studied responsiveness in five different ways:(1)response threshold,(2)concentration 50(concentration to which at least 50%of wasps responded),(3)maximum response,(4)mean scores and(5)median scores.Our results suggest that V germanica foragers are more sensitive to sucrose(lower thresholds)than preforager workers.However,we found no differences for peptone thresholds(i.e.,a protein resource).Nonetheless,this is the first study to investigate response thresholds for protein resources.The intercaste variation in sucrose responsiveness shown in our work contributes to the existing knowledge about response threshold theory as a mechanism for task specialization observed in V germanica.

Flexible foraging decisions made by workers of the social wasp Vespula germanica (Hymenoptera: Vespidae) in response to different resources: influence of ontogenetic shifts and colony feedback

Decisions made by foraging animals conform a complex process based on the integration of information from multiple external environmental stimuli and internal physiological signals,which in turn are modulated by individual experience and a detection threshold of each individual.For social insects in which foraging is limited to given age subcastes,individual foraging decisions may also be affected by ontogenetic shifts and colony requirements.We studied the short-term changes in foraging preferences of the generalist wasp Vespula germanica,focusing on whether the individual response to different resources could be influenced by the ontogenetic shifts and/or by social interaction with nestmates.We carried both laboratory and field experiments to confront worker wasps to a short-term resource switch between either protein or carbohydrate-based foods.We tested the response of(1)Preforager workers(no foraging experience nor interaction with other wasps),(2)Forager workers(experience in foraging and no colony feedback),and(3)Wild forager workers(foraging naturally and exposed to free interactions with nestmates).We evaluated the maxilla-labium extension response(MaLER)for laboratory assays or the landing response for field assays.We observed that for wasps deprived of colony feedback(either preforagers or foragers),the protein-rich foods acceptance threshold increased(and thus a lower level of foraging on that item was observed)if they had foraged on carbohydrates previously,whereas carbohydrates were accepted in all assays.However,wasps immersed in a natural foraging context did accept protein foods regardless of their first foraging experience and reduced the carbohydrates collected when trained on protein foods.We provide evidence that short-term changes in foraging preferences depend on the type of resource foraged and on the social interactions,but not on ontogenetic shifts.