High resolution tracking of adult horseshoe crabs Limulus polyphemus in a New Hampshire estuary using fixed array ultrasonic telemetry

While several studies have documented the large-scale, seasonal movements of horseshoe crabs, little is known about their fine-scale, daily movement patterns. In this study we used a fixed array ultrasonic telemetry system to track the movements of 12 male and 16 female horseshoe crabs in the Great Bay estuary, New Hampshire. Data were obtained during the mating season, as well as during the remainder of the summer and fall, in the years 2005-2008. During the mating season animals were often, but not always, active during the high tides when they were approaching and leaving the spawning beaches. On average, both males and females approached mating beaches during 33% of the high tides they experienced and they most often made the tran- sition from being inactive to active during the last two hours of an incoming tide. From April-October horseshoe crabs were significantly more active during high tide periods vs low tide periods, with no clear preference for diurnal vs nocturnal activity. After the mating season ended horseshoe crabs continued to move into shallower water at high tide and then return to deeper water at low tide. Observations by SCUBA divers suggest that during these excursions into the mudflats horseshoe crabs were digging pits in the sediment while foraging for food. Thus, the tidal rhythm of activity that has been so well documented during the mating season probably persists into the fall, and primarily involves foraging activities

Seasonal movements of American horseshoe crabs Limulus polyphemus in the Great Bay Estuary,New Hampshire (USA)

The goal of this study was to determine the year round movement patterns of American horseshoe crabs, Limulus polyphemus, in the Great Bay Estuary, New Hampshire （USA） by using acoustic telemetry to track the movements of 37 adult Limulus, for periods ranging from 2 to 31 months. During the winter （December-March） horseshoe crabs moved very little. In the spring, when water temperatures exceeded II^C, horseshoe crabs moved at least 1 km further up into the estuary to shallower subtidal areas about a month prior to spawning. The mean distance traveled during spring migrations was 2.6 ＋ 0.5 （n=20） km up the estuary. Mating occurred in May and June and during these months animals spent most of their time in shallow subtidal areas adjacent to mating beaches. In the summer （July-Augnst）, animals moved 1.5 ± 0.5 （n=26） km down the estuary, towards the ocean, and ranged widely, using extensive portions of the estuary. In the fall （September-November） movement was more limited （0.5 ± 0.5 km; n = 24） while animals settled into wintering locations, where they remained until spring. The mean annual linear range for all animals was 4.5 ± 0.3 km （n =35） and the maximum distance traveled by an individual horseshoe crab within one year was 9.2 km. There was no evidence that any of the horseshoe crabs tracked during this study left the estuary

Circatidal rhythms of locomotion in the American horseshoe crab Limulus polyphemus: Underlying mechanisms and cues that influence them

While eye sensitivity in the American horseshoe crab Limulus polyphemus has long been known to be under the control of an endogenous circadian clock, only recently has horseshoe crab locomotion been shown to be controlled by a separate clock system. In the laboratory, this system drives clear activity rhythms throughout much of the year, not just during the mating season when horseshoe crabs express clear tidal rhythms in the field. Water temperature is a key factor influencing the expression of these rhythms： at 17~C tidal rhythms are expressed by most animals, while at I l^C expression of circatidal rhythms is rarely seen, and at 4~C rhythms are suppressed. Neither long （16：8 Light：Dark） nor short （8：16） photoperiods modify this behavior at any of these temperatures. Synchronization of these circatidal rhythms can be most readily effeeted by water pressure cycles both in situ and in the lab, while temperature and current cycles play lesser, but possibly contributory, roles. Interestingly, Light：Dark cycles appear to have synchronizing as well as ＂masking＂ effects in some individuals. Evidence that each of two daily bouts of activity are independent suggests that the Limulus circatidal rhythm of locomotion is driven by two （circalunidian） clocks, each with a period of 24.8h. While the anatomical locations of either the circadian clock, that drives fluctuations in visual sensitivity, or the circatidal clock, that controls tidal rhythms of locomotion, are currently unknown, preliminary molecular analyses have shown that a 71 kD protein that reacts with antibodies directed against the Drosophila PERIOD （PER） protein is found in both the pro- tocerebrum and the subesophageal ganglion

Horseshoe crab behavior:Patterns and processes

1 Introduction The Ameriean horseshoe erab Limulus PolyPhemus has long served as a souree of delight and insPiration to a broad eross-seetion of seientists-from naturalists to neuroseientists.Periodieally, for the last hundred years or so,new discoveries have been made

Virtue Education： Josef Pieper＇s Vita Contemplativa as Pedagogical Ground

Virtue education in the United States has lost its clout while the corporatization of higher education may be at its peak. The focus of traditional education has shifted from ideas, wisdom, and the love of learning to having a corporate mindset on progress and skills-based knowledge. In many cases, the focus of attention is on remaining viable/sustainable in times of economic decline rather than learning itself, so the resources supporting institutions of higher education are directed into marketing and public relations practices instead of the infrastructure for thinking and learning. This essay draws together three coordinates to make a case for a return to virtue education in the United States. First, the current condition of higher education is shown to have dubiously strayed from a virtue model. Second, the re-emergence of philosophy as a preferred major and its growth in the academy suggest that people realize that something has to change in higher education as they revert back to a broad liberal arts emphasis. Third, a discussion of virtue education from the lens of Josef Pieper＇s virtue philosophy, grounded in the lSta Contemplativa, offers renewed possibility to reengaged higher education for a sustainable future. Together, I suggest that the tradition of higher education in the United States is no longer viable and return to a virtue education model is an alternative that might make higher education sustainable.

Effect of time-of-day and day-of-the-week on congestion duration and breakdown:A case study at a bottleneck in Salem,NH

This work uses regression models to analyze two characteristics of recurrent congestion： breakdown, the transition from freely flowing conditions to a congested state, and duration, the time between the onset and clearance of recurrent congestion. First, we apply a binary logistic regression model where a continuous measurement for traffic flow and a dichoto- mous categorical variable for time-of-day （AM- or PM-rush hours） is used to predict the probability of breakdown. Second, we apply an ordinary least squares regression model where categorical variables for time-of-day （AM- or PM-rush hours） and day-of-the-week （Monday-Thursday or Friday） are used to predict recurrent congestion duration. Models are fitted to data collected from a bottleneck on 1-93 in Salem, NH, over a period of 9 months. Results from the breakdown model, predict probabilities of recurrent congestion, are consistent with observed traffic and illustrate an upshift in breakdown probabilities between the AM- and PM-rush periods. Results from the regression model for congestion duration reveal the presences of significant interaction between time-of-day and day-of-the-week. Thus, the effect of time-of-day on congestion duration depends on the day-of-the-week. This work provides a simplification of recurrent congestion and recovery, very noisy processes. Simplification, conveying complex relationships with simple statistical summaries-facts, is a practical and powerful tool for traffic administrators to use in the decision-making process.

Tensegrity: A Novel Conceptual Framework for Rehabilitation of Functional Deficits for Breast Cancer Survivors

The current approach to breast cancer rehabilitation is currently narrowly focused on addressing resultant problems such as lymphedema or shoulder pain.Referrals to rehabilitation are reactive responses to these problems.Taking a step back and looking at the breast cancer intervention in totality,it becomes apparent that steps could be taken to minimize or actu-ally prevent some of the ensuing functional problems by proactively treating a breast cancer survivor.Rather than waiting for problems to arise,immediately post-intervention or ideally pre-intervention and throughout intervention referral of an individual to rehabilitation could provide a supportive role in the functional progression of the patient.Furthermore,while most orthopedic rehabilitation focuses on the function of a particular joint,with the extensive impact of the breast cancer treatments on the soft tissue of the body without any specific intervention at a joint,it is imperative that we begin to shift our rehabilitation approach to focusing on the alterations of the soft tissue prior to addressing any functional limitations in the joints,with the most common victim being the shoulder joint.This novel approach to breast cancer rehabilitation sug-gests initially addressing soft tissue limitations.As these limitations begin to resolve as optimally as possible,secondary consideration is then given to functional limitations of a joint such as the shoulder joint.