The development of path integration: combining estimations of distance and heading

Efficient daily navigation is underpinned by path integration, the mechanism by which we use self-movement information to update our position in space. This process is well-understood in adulthood, but there has been relatively little study of path integration in childhood, leading to an underrepresentation in accounts of navigational development. Previous research has shown that calculation of distance and heading both tend to be less accurate in children as they are in adults, although there have been no studies of the combined calculation of distance and heading that typifies naturalistic path integration. In the present study 5-year-olds and 7-year-olds took part in a triangle-completion task, where they were required to return to the startpoint of a multi-element path using only idiothetic information. Performance was compared to a sample of adult participants, who were found to be more accurate than children on measures of landing error, heading error, and distance error. 7-year-olds were significantly more accurate than 5-year-olds on measures of landing error and heading error, although the difference between groups was much smaller for distance error. All measures were reliably correlated with age, demonstrating a clear development of path integration abilities within the age range tested. Taken together, these data make a strong case for the inclusion of path integration within developmental models of spatial navigational processing

Spatial memory in the grey mouse lemur (Microcebus murinus)

Wild animals face the challenge of locating feeding sites distributed across broad spatial and temporal scales. Spatial memory allows animals to find a goal, such as a productive feeding patch, even when there are no goal-specific sensory cues available. Because there is little experimental information on learning and memory capabilities in free-ranging primates, the aim of this study was to test whether grey mouse lemurs (Microcebus murinus), as short-term dietary specialists, rely on spatial memory in relocating productive feeding sites. In addition, we asked what kind of spatial representation might underlie their orientation in their natural environment. Using an experimental approach, we set eight radio-collared grey mouse lemurs a memory task by confronting them with two different spatial patterns of baited and non-baited artificial feeding stations under exclusion of sensory cues. Positional data were recorded by focal animal observations within a grid system of small foot trails. A change in the baiting pattern revealed that grey mouse lemurs primarily used spatial cues to relocate baited feeding stations and that they were able to rapidly learn a new spatial arrangement. Spatially concentrated, non-random movements revealed preliminary evidence for a route-based restriction in mouse lemur space; during a subsequent release experiment, however, we found high travel efficiency in directed movements. We therefore propose that mouse lemur spatial memory is based on some kind of mental representation that is more detailed than a route-based network map

International Journal of Multidisciplinary and Current Research Effect of Fermentation Process on the Improvement of Nutrition Value of Camel Milk

Abstract This study was carried out to determine the effect of fermentation process using lactic acid bacteria on nutrition value of camel milk

Middle Bronze Age oil lamps from As-Salt (Jordan)

This article focuses on eight new oil lamps excavated by As-Salt archaeology office at Tell- Al-Gadur and As-Salalm, in As-Salt, Jordan. Based on their form and related stratigraphic evidence, these pottery oil lamps date to the EBIV-MBI Period. All of them found in tombs discovered during excavation, they appear to have never been used

Middle Bronze Age oil lamps from As-Salt (Jordan)

This article focuses on eight new oil lamps excavated by As-Salt archaeology office at Tell- Al-Gadur and As-Salalm, in As-Salt, Jordan. Based on their form and related stratigraphic evidence, these pottery oil lamps date to the EBIV-MBI Period. All of them found in tombs discovered during excavation, they appear to have never been used

Synthesis of New Heterocycles from Reactions of 1-Phenyl-1H-pyrazolo[3,4-b]pyridine-5-carbonyl Azides

Two individual examples of pyrazolo[3,4-b]pyridine-5-carbonyl azides and hydrazides were reacted with various nucleophilic reagents. Different unexpected behaviors was observed. NMR, IR, mass spectra together with elemental analyses and X-ray structure analyses, were used to prove the structure of the obtained products.Peer reviewe