Rhythms of Locomotion Expressed by Limulus polyphemus, the American Horseshoe Crab: II. Relationship to Circadian Rhythms of Visual Sensitivity

In the laboratory, horseshoe crabs express a circadian rhythm of visual sensitivity as well as daily and circatidal rhythms of locomotion. The major goal of this investigation was to determine whether the circadian clock underlying changes in visual sensitivity also modulates locomotion. To address this question, we developed a method for simultaneously recording changes in visual sensitivity and locomotion. Although every animal (24) expressed consistent circadian rhythms of visual sensitivity, rhythms of locomotion were more variable: 44% expressed a tidal rhythm, 28% were most active at night, and the rest lacked statistically significant rhythms. When exposed to artificial tides, 8 of 16 animals expressed circatidal rhythms of locomotion that continued after tidal cycles were stopped. However, rhythms of visual sensitivity remained stable and showed no tendency to be influenced by the imposed tides or locomotor activity. These results indicate that horseshoe crabs possess at least two biological clocks: one circadian clock primarily used for modulating visual sensitivity, and one or more clocks that control patterns of locomotion. This arrangement allows horseshoe crabs to see quite well while mating during both daytime and nighttime high tides

Effective Utilization of a Questioned Document Examiner

I. Introduction II. Document Examination as a Profession … A. Historical Development … B. Qualifications of the Document Expert III. Development of a Document Case by the Attorney … A. General … B. Evidence of Invalidity … C. Classification of Questioned Documents … D. Capabilities of a Qualified Document Examiner … E. Care and Preservation of Disputed Document … F. Interviews with Prospective Witnesses … G. Acquisition of Standards … 1. General … 2. Collected Standards … 3. Requested Standards … H. Collateral Study IV. Function of Document Examiner upon Referral and before Trial … A. Referral to Document Examiner … B. Types of Examination Made by Trained Examiner … C. Report of the Document Examiner … D. Preparation of Document Examiner for Trial … E. Pre-Trial Conference V. Trial … A. General … B. Proof of Genuine Specimens … C. Establishing Qualifications of Document Examiner … D. Direct Testimony … E. Cross-Examination … F. Redirect Examination … G. Weight Given to Testimony of Examiner VI. Post-Trial Conference … A. Critique … B. Fees VII. Conclusio

A Proposal for Changing Florida\u27s Civil Commitment System

For purposes of this analysis, civil commitment is a form of noncriminal confinement for those who are legally found to be mentally ill.1 With the minor exception of rare confinement for some communicable diseases, there is no analogue of involuntary commitment for physical illness

Circatidal and Circadian Rhythms of Locomotion in Limulus polyphemus

The nocturnal increases in the sensitivity of the lateral eye of Limulus polyphemus, the species of horseshoe crab found along the Atlantic coast, have been firmly established as being controlled by an endogenous circadian clock (1,2,3) located in the brain (4). Virtually nothing is known, however, about the control of the animal’s behavioral rhythms of mating and spawning that are observed in the intertidal zone during high tides in late spring (5,6,7). Many other marine species, especially intertidal crabs, exhibit similar rhythmic behaviors that have been demonstrated to be under the control of endogenous clocks that are circatidal (8,9,10,11,12), circadian (10,12), or both. While there is some evidence that the activity of juvenile horseshoe crabs is primarily nocturnal (13,14), and possibly controlled by a circadian clock (14), we know of no published work showing that locomotor activity in the adult is endogenously controlled on either a 12.4-h (circatidal) or 24-h (circadian) basis. We report here that locomotor activity in adult individuals of L. polyphemus is endogenously modulated on both a circatidal and a circadian basis and that when the animals are subjected to a light-dark (LD) cycle, most activity occurs at night

Effective Utilization of a Questioned Document Examiner

I. Introduction II. Document Examination as a Profession … A. Historical Development … B. Qualifications of the Document Expert III. Development of a Document Case by the Attorney … A. General … B. Evidence of Invalidity … C. Classification of Questioned Documents … D. Capabilities of a Qualified Document Examiner … E. Care and Preservation of Disputed Document … F. Interviews with Prospective Witnesses … G. Acquisition of Standards … 1. General … 2. Collected Standards … 3. Requested Standards … H. Collateral Study IV. Function of Document Examiner upon Referral and before Trial … A. Referral to Document Examiner … B. Types of Examination Made by Trained Examiner … C. Report of the Document Examiner … D. Preparation of Document Examiner for Trial … E. Pre-Trial Conference V. Trial … A. General … B. Proof of Genuine Specimens … C. Establishing Qualifications of Document Examiner … D. Direct Testimony … E. Cross-Examination … F. Redirect Examination … G. Weight Given to Testimony of Examiner VI. Post-Trial Conference … A. Critique … B. Fees VII. Conclusio

Sublethal Behavioral and Physiological Effects of the Biomedical Bleeding Process on the American Horseshoe Crab, Limulus polyphemus

The hemolymph of the American horseshoe crab, Limulus polyphemus, is harvested from over 500,000 animals annually to produce Limulus amebocyte lysate (LAL), a medically important product used to detect pathogenic bacteria. Declining abundance of spawning Limulus females in heavily harvested regions suggests deleterious effects of this activity, and while mortality rates of the harvest process are known to be 10%–30%, sublethal behavioral and physiological effects are not known. In this study, we determined the impact of the harvest process on locomotion and hemocyanin levels of 28 female horseshoe crabs. While mortality rates after bleeding (18%) were similar to previous studies, we found significant decreases in the linear and angular velocity of freely moving animals, as well as changes in their activity levels and expression of circatidal behavioral rhythms. Further, we found reductions in hemocyanin levels, which may alter immune function and cuticle integrity. These previously unrecognized behavioral and physiological deficits suggest that the harvest of LAL may decrease female fitness, and thus may contribute to the current population decline

Rhythms of Locomotion Expressed by Limulus polyphemus, the American Horseshoe Crab: I. Synchronization by Artificial Tides

Limulus polyphemus, the American horseshoe crab, has an endogenous clock that drives circatidal rhythms of locomotor activity. In this study, we examined the ability of artificial tides to entrain the locomotor rhythms of Limulus in the laboratory. In experiments one and two, the activity of 16 individuals of L. polyphemus was monitored with activity boxes and “running wheels.” When the crabs were exposed to artificial tides created by changes in water depth, circatidal rhythms were observed in animals exposed to 12.4-h “tidal” cycles of either water depth changes (8 of 8 animals) or inundation (7 of 8 animals). In experiment three, an additional 8 animals were exposed to water depth changes under cyclic conditions of light and dark and then monitored for 10 days with no imposed artificial tides. Most animals (5) clearly synchronized their activity to the imposed artificial tidal cycles, and 3 of these animals showed clear evidence of entrainment after the artificial tides were terminated. Overall, these results demonstrate that the endogenous tidal clock that influences locomotion in Limulus can be entrained by imposed artificial tides. In the laboratory, these tidal cues override the influence of light/dark cycles. In their natural habitat, where both tidal and photoperiod inputs are typically always present, their activity rhythms are likely to be much more complex