Comparative ecology of the parasites of the spot, Leiostomus xanthurus Lacepede, and the Atlantic croaker, Micropogonias undulatus Linnaeus (Sciaenidae), in the Cape Hatteras region

Parasite communities of spot, Leiostomus xanthurus, and Atlantic croaker, Micropogonias undulatus, were examined to determine if (1) their structure changed with host age, (2) geographical location affected community structure, (3) food habits affected community structure, and (4) their parasite communities are predictable. Juvenile fish were collected monthly from Chesapeake Bay and Pamlico Sound. Adult fish were collected offshore north of Cape Hatteras in fall, and offshore south of Cape Hatteras in spring and fall. A total of 21 parasitic species occurred in juvenile spot and 19 in juvenile croaker from Chesapeake Bay and Pamlico Sound. The parasite communities of juvenile fishes varied with size, season, and area. Although juvenile spot and croaker shared eight and six parasites between estuaries, respectively, many nonspecific parasites (generalists) were more common in both spot and croaker from one estuary than the other. The estuary of residence was as important as host species identity in determining parasite community structure. Twenty-three species of metazoan parasites were recorded from adult spot and 26 from adult croaker. of the 33 parasitic species found, 17 occurred in both spot and croaker. All parasites had overdispersed or clumped distributions among hosts. Adult spot and croaker collected offshore had much greater species-richness, diversity, and total number of individual parasites than juvenile fishes collected in adjoining estuaries. The number of species and diversity of parasites in adult fish was greater in croaker than spot. However, when only gastrointestinal helminths were considered, spot had greater species-richness as well as greater numbers of individual helminths. Comparison of adult spot and croaker parasite faunas collected offshore indicated that their respective parasite component communities were distinct and that similar infracommunity variability existed in both hosts. Although the parasite dominance hierarchy in adults of both species varied slightly between areas and seasons, there appeared to be predictable dominant species. The core species were accompanied by subordinate, less predictable species. Variability in both relative intensities and presence absence of parasites within communities resulting from their diverse diets made them less predictable than those of other vertebrates with less diverse diets

Bibliography of the Monogenetic Trematode Literature of the World, 1758 to 1982

Interest in the monogenean parasites has grown markedly in the last twenty years. To enhance and speed world-wide research activity, we prepared the first edition of this bibliography in 1969. This latest effort is intended to do the same

Satisfying due-dates in a job shop with sequence-dependent family set-ups

This paper addresses job shop scheduling with sequence dependent family set-ups. Based on a simple, single-machine dynamic scheduling problem, state dependent scheduling rules for the single machine problem are developed and tested using Markov Decision Processes. Then, a generalized scheduling policy for the job shop problem is established based on a characterization of the optimal policy. The policy is combined with a 'forecasting' mechanism to utilize global shop floor information for local dispatching decisions. Computational results show that performance is significantly better than that of existing alternative policies

US Army Aviation air movement operations assignment, utilization and routing

Purpose – The purpose of this study was to create an air movement operations planning model to rapidly generate air mission request (AMR) assignment and routing courses of action (COA) in order to minimize unsupported AMRs, aircraft utilization and routing cost. Design/methodology/approach – In this paper, the US Army Aviation air movement operations planning problem is modeled as a mixed integer linear program (MILP) as an extension of the dial-a-ride problem (DARP). The paper also introduces a heuristic as an extension of a single-vehicle DARP demand insertion algorithm to generate feasible solutions in a tactically useful time period. Findings – The MILP model generates optimal solutions for small problems (low numbers of AMRs and small helicopter fleets). The heuristic generates near-optimal feasible solutions for problems of various sizes (up to 100 AMRs and 10 helicopter team fleet size) in near real time. Research limitations/implications – Due to the inability of the MILP to produce optimal solutions for mid- and large-sized problems, this research is limited in commenting on the heuristic solution quality beyond the numerical experimentation. Additionally, the authors make several simplifying assumptions to generalize the average performance and capabilities of aircraft throughout a flight. Originality/value – This research is the first to solve the US Army Aviation air movement operations planning problem via a single formulation that incorporates multiple refuel nodes, minimization of unsupported demand by priority level, demand time windows, aircraft team utilization penalties, aircraft team time windows and maximum duration and passenger ride time limits