Looping Pattern Research Articles

Saltatory search in a lateral line predator

The dwarf scorpionfish Scorpaena papillosa detected the hydrodynamic signals produced by prey with the mechanosensory lateral line. This species displayed a pause and move search pattern that is consistent with a saltatory search. The pause phase of the search cycle was probably used to detect prey because pauses often ended early in order to initiate an approach at prey and prey were detected throughout the search space. The move phase of the search cycle repositioned the fish so that it moved approximately a third of the reactive distance. Move distance was found to be the most important factor in gaining novel search space. Turning was shown to be relatively unimportant in gaining novel search space with a high frequency of low turn angles made by the fish. The dwarf scorpionfish, however, exhibited a spiralling or looping pattern over a search path exhibiting a turn bias towards either the left or right. The dwarf scorpionfish adopted a search behaviour that is consistent with a saltatory search and efficient for lateral line predation.

Can origin of the 2400-year cycle of solar activity be caused by solar inertial motion?

Abstract. A solar activity cycle of about 2400 years has until now been of uncertain origin. Recent results indicate it is caused by solar inertial motion. First we describe the 178.7-year basic cycle of solar motion. The longer cycle, over an 8000 year interval, is found to average 2402.2 years. This corresponds to the Jupiter/Heliocentre/Barycentre alignments (9.8855 × 243). Within each cycle an exceptional segment of 370 years has been found characterized by a looping pattern by a trefoil or quasitrefoil geometry. Solar activity, evidenced by 14C tree-ring proxies, shows the same pattern. Solar motion is computable in advance, so this provides a basis for future predictive assessments. The next 370-year segment will occur between AD 2240 and 2610.Key words: Solar physics (celestial mechanics)

Can origin of the 2400-year cycle of solar activity be caused by solar inertial motion?

A solar activity cycle of about 2400 years has until now been of uncertain origin. Recent results indicate it is caused by solar inertial motion. First we describe the 178.7-year basic cycle of solar motion. The longer cycle, over an 8000 year interval, is found to average 2402.2 years. This corresponds to the Jupiter/Heliocentre/Barycentre alignments (9.8855 × 243). Within each cycle an exceptional segment of 370 years has been found characterized by a looping pattern by a trefoil or quasitrefoil geometry. Solar activity, evidenced by 14C tree-ring proxies, shows the same pattern. Solar motion is computable in advance, so this provides a basis for future predictive assessments. The next 370-year segment will occur between AD 2240 and 2610.Key words: Solar physics (celestial mechanics)

Salivary Duct Carcinoma in Five Cats

Carcinomas1999 Harcourt Publishers Ltdof salivary gland ducts are described in five cats. The typical histological pattern was the formation of large cell aggregates resembling dilated ducts, often with central necrosis and a looping pattern. All tumours were labelled with antibody to cytokeratins (CKs) 5, 6, 8, 14, 17 and 19. Labelling of tumour cells with CK14 suggested basal cell differentiation. All tumours stained with Jack bean (Copyright Canavalia ensiformis) agglutinin (Con A); this is a feature of normal salivary gland ducts but is seen in other salivary gland tumours. Staining of tumour cells at the luminal surface of ductal structures with wheat germ (Triticum vulgaris) agglutinin (WGA) in the cat tumours was similar to that seen in ducts of normal cat salivary glands but occurs in other cat tumours. Other immunohistochemical staining results were unremarkable. 1999 W.B. Saunders and Company Ltd.

Cardiac laterality and ventricular looping in retinoic acid-treated rat embryos.

To determine the ventricular looping pattern in relation to cardiac laterality, we studied rat embryos treated with retinoic acid (RA). A total of 243 Wistar rat embryos from an in vivo treated group (a single dose of 20-40 mg/kg all-trans RA administered to pregnant rats on day 6.5 to 9.5) and 29 control embryos were examined on day 13 of gestation. Twenty-nine embryos from the in-vitro treated group (treated by all-trans RA at 2 x 10(-7) M for 6 hr on day 9.0 or 9.5 during the entire embryo culture for 72 hr) and seven control embryos were examined on day 12 of gestation. Abnormalities in cardiac laterality and ventricular looping were found in the in-vivo groups treated on day 8.5 and 8.75 and in the in-vitro group on day 9.0. Among 25 animals with abnormal laterality, right isomerism was the most common feature (22 cases), while the type of ventricular looping varied. Cases with normal laterality had a low incidence of abnormal looping (1.4%). In rat embryos treated with all-trans RA, normal cardiac looping was expected when cardiac laterality was normal. But in cases with abnormal laterality, the type of abnormal ventricular looping was unexpected.

Relict flow stripes on the Ross Ice Shelf

Analysis of AVHRR data collected during the summer and winter over the Ross Ice Shelf reveals complex patterns of curvilinear stripes. In particular, a large, looping pattern of stripes is observed west of Crary Ice Rise in an area where conventional glaciological data collected with surface and airborne methods have been interpreted to suggest uncomplicated flow. On the basis of previous work using radar data to study ice flow downstream of Crary Ice Rise, we conclude that the stripes represent relict flowlines. The mechanism that produces these stripes is unclear, but we hypothesize that they are associated with subtle topography. Based solely on the patterns of stripes and their location in the outflow of major ice streams, we propose that they are related to an ice raft torn from the grounded ice sheet about 400 km upstream from its present position.

Relict flow stripes on the Ross Ice Shelf

Analysis of AVHRR data collected during the summer and winter over the Ross Ice Shelf reveals complex patterns of curvilinear stripes. In particular, a large, looping pattern of stripes is observed west of Crary Ice Rise in an area where conventional glaciological data collected with surface and airborne methods have been interpreted to suggest uncomplicated flow. On the basis of previous work using radar data to study ice flow downstream of Crary Ice Rise, we conclude that the stripes represent relict flowlines. The mechanism that produces these stripes is unclear, but we hypothesize that they are associated with subtle topography. Based solely on the patterns of stripes and their location in the outflow of major ice streams, we propose that they are related to an ice raft torn from the grounded ice sheet about 400 km upstream from its present position.

Atropine sulfate impairs selective parameters of performance in the Morris water maze

Twelve rats were trained to learn the location of a spatially fixed platform hidden in a Morris water maze. Asymptotic performance was achieved over six training days (10 trials/day). Then retention of the spatial task was assessed 30 min after treatment with 5, 25, 50, 75, or 100 mg/kg, ip, atropine sulfate or the equivalent volume of saline. There was a significant drug effect on escape latency, swim distance, swim speed and swim path measures of spatial performance. There was no significant drug effect on heading error; atropinized animals initially headed toward the escape platform over the first 12 cm of their swim path. However, treatment with atropine sulfate significantly disrupted the usual, direct swim path used to reach the hidden escape platform. Atropinized animals frequently swam a spiraled or looping pattern to locate the platform. We suggest that cholinergic blockade may significantly disrupt the processing of visual cues which rats use in place navigation tasks.

Timber Rattlesnakes (Crotalus horridus) of the Pine Barrens: Their Movement Patterns and Habitat Preference

Radiotelemetry was used to monitor the movements and habitat use of timber rattlesnakes (Crotalus horridus) in the Pine Barrens of southern New Jersey. Reproductive condition strongly influenced both aspects of behavior. Males generally exhibited the largest activity ranges, and the sizes of their ranges were positively correlated with the number of days the snakes were monitored. This was not true for gravid or non-gravid females. Time series analyses indicated that movement patterns of males and non-gravid females consisted of constantly shifting, non-overlapping activity areas. In most cases these snakes moved in a looping pattern during the active season that returned them to the same hibernation site from which they departed. Gravid females exhibited more static, overlapping activity areas and shorter dispersal distances from hibernacula. Males and non-gravid females utilized forested habitat with greater than 50% canopy closure, thick surface vegetation (approx. 75%), and few fallen logs. This habitat occurred with high frequency throughout the study area. Gravid snakes utilized less densely forested sites with approx. 25% canopy closure, an equal mixture of vegetation and leaf litter covering the surface, frequent fallen logs, and warmer climatic conditions. This habitat occurred in low frequency on the study area and was largely restricted to the edge of sand roads.

Horizontal Variability of temperature microstructure at the base of a mixed layer during MILE

Horizontal observations of temperature microstructure made during the Mixed Layer Experiment (MILE) show that the distribution of mixing activity in the seasonal thermocline at the base of the surface mixed layer was highly intermittent in horizontal planes. The horizontal extent of the observed microstructure patches was usually less than 10 m. The patches tended to occur in groups extending over distances of a few hundred meters, although some were isolated. Many patches of temperature microstructure activity occurred at density fronts separating regions of strong but opposite horizontal temperature‐salinity (T‐S) gradients. The sequence of horizontally averaged T‐S values form a looping pattern on a T‐S diagram which suggests that horizontal stirring processes are a source of microstructure generation. Spatial averages of the Cox number 〈(∇T)2〉/〈∇T〉2 and χ, the temperature variance dissipation rate, are determined by very small ractions of the record lengths, usually less than 5%. The distribution of χ was found to be approximately lognormal with variance of log10 χ of about 1.0, mean of 1.1×10−6 °C2/s, and mode 3.9×10−10 °C2/s. Good agreement was found with X values measured by dropsondes during MILE after accounting for the strong intermittency.