Sensing Victory This video shows a zebrafish embryo as it…

Sensing Victory

This video shows a zebrafish embryo as it develops an elaborate network of neurons, the sensory nervous system, which will allow it to make sense of the world around it. Sights, smells and tastes are detected by receptors then encoded into electronic signals that are transmitted along the wire-like axons of sensory neurons. Captured here, developing axons are sprouting upwards, away from the circular cell body of each neuron. The axons form an elaborate, spider-web like network. Sixteen hours of time-lapse footage were sped-up to form this short clip. It was captured with an unconventional microscope technique that allowed the embryo to grow in water, its natural environment. This was more challenging than standard techniques that typically hold specimens in place during filming. Such high-quality footage helps researchers to investigate how healthy neurons develop and what might go wrong in neurodegenerative diseases.

Written by Deborah Oakley

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Experimental work reproduces the knapping process at Olduvai

Alfonso Benito Calvo, a geologist at the Centro Nacional de Investigación sobre la Evolución Humana (CENIEH) has participated in a paper published recently in the journal Archaeological and Anthropological Sciences, which reproduced the knapping process observed at Olduvai (Tanzania), using one of the most abundant raw materials at those sites, quartzite rocks.

Experimental work reproduces the knapping process at Olduvai
Credit: CENIEH

This was experimental work on which members from the CENIEH, University College London, Max Planck Institute and from the Universidad Autónoma de Barcelona have collaborated, based on studying the spatial patterns of the refits, that is to say, the assembly or matching of the lithic material to reconstruct the original geometry prior to knapping.
First, the quartzite rocks were knapped, and then the position and orientation of each resulting fragment were plotted exhaustively, yielding detailed maps showing the distribution of the materials.

“Starting from these maps, we have carried out a spatial analysis of the layout of the fragments and their refits, using GIS applications, designed for specialist analysis of spatial databases,” explains Benito.
The results obtained have shown very different spatial patterns characteristic of each knapping technique: bipolar or freehand. Comparison of these theoretical experimental patterns with the distribution found in the sites will allow the amount of post-depositional disturbance suffered by the sites to be quantified, and thus further investigation of the processes which have affected them.

Source: CENIEH [October 24, 2018]

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New projectile point style could suggest two separate migrations into North America

Texas A&M University researchers have discovered what are believed to be the oldest weapons ever found in North America: ancient spear points that are 15,500 years old. The findings raise new questions about the settlement of early peoples on the continent.

New projectile point style could suggest two separate migrations into North America
An excavation takes place at the Debra L. Friedkin site in 2016
[Credit: Texas A&M University]

Michael Waters, distinguished professor of anthropology and director of the Center for the Study of the First Americans at Texas A&M, and colleagues from Baylor University and the University of Texas have had their work published in the current issue of Science Advances.
The team found the numerous weapons — about 3-4 inches long — while digging at what has been termed the Debra L. Friedkin site, named for the family who owns the land about 40 miles northwest of Austin in Central Texas. The site has undergone extensive archaeological work for the past 12 years.

Spear points made of chert and other tools were discovered under several feet of sediment that dating revealed to be 15,500 years old, and pre-date Clovis, who for decades were believed to be the first people to enter the Americas.

New projectile point style could suggest two separate migrations into North America
A 15,000 year old stemmed point [Credit: Texas A&M University]

“There is no doubt these weapons were used for hunting game in the area at that time,” Waters said. “The discovery is significant because almost all pre-Clovis sites have stone tools, but spear points have yet to be found. These points were found under a layer with Clovis and Folsom projectile points. Clovis is dated to 13,000 to 12,700 years ago and Folsom after that. The dream has always been to find diagnostic artifacts — such as projectile points — that can be recognized as older than Clovis and this is what we have at the Friedkin site.”
Clovis is the name given to the distinctive tools made by people starting around 13,000 years ago. The Clovis people invented the “Clovis point,” a spear-shaped weapon made of stone that is found in Texas and parts of the United States and northern Mexico and the weapons were made to hunt animals, including mammoths and mastodons, from 13,000 to 12,700 years ago.

“The findings expand our understanding of the earliest people to explore and settle North America,” Waters said. “The peopling of the Americas during the end of the last Ice Age was a complex process and this complexity is seen in their genetic record. Now we are starting to see this complexity mirrored in the archaeological record.”

Author: Keith Randall | Source: Texas A&M University [October 24, 2018]

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