Complexity constrains evolution of human brain genes
Despite the explosive growth in size and complexity of the human brain, the pace of evolutionary change among the thousands of genes expressed in brain tissue has actually slowed since the split, millions of years ago, between human and chimpanzee, an international research team reports in the Dece...
Breaking the ties that bind: New hope for biomass fuels
... can shift to remain stable under a wide range of temperatures. This plasticity allows the material to swap different types of hydrogen bonds but also constrains
the molecules so that they must form bonds in the weaker configuration described by Langan and his colleagues. Most important, Shen and Gnanakaran's m...
AGU journal highlights -- Oct. 16, 2008
... coast of Greenland. However, how deep water circulates within these basins is not well known. Noting that the shape of the ocean bottom significantly constrains
fluid motion in weakly stratified deep waters, Siland et al. study the positions of neutrally buoyant subsurface drifting floats that were deployed ac...
Genes and nutrition influence caste in unusual species of harvester ant
... on Pogonomyrmex harvester ants have found colonies in which becoming a worker or gyne is determined exclusively by genetic differences. Such rigidity constrains
the colony's ability to adaptively adjust to environmental realities. For example, colonies that have few workers and yet produce a lot of larvae that...
Scientists may have solved an ecological riddle
...m developed two new hypotheses for understanding the distribution of nitrogen fixing plants across global ecosystems.
The first is that temperature constrains
the distribution of nitrogen fixation, contributing to the lack of nitrogen-fixing trees in mature forests at high latitudes.
The second that nitr...
At the root of nutrient limitation, ecosystems are not as different as they seem
...a system responds positively to the initial nitrogen addition, it is said to be nitrogen-limited, because the availability of nitrogen instantaneously constrains
the productivity of the ecosystem. The converse is true in phosphorus-limited systems.
Plant production in both cases is limited by the nutrient i...
New insights into how lasers cut flesh
...er of differences.
One such difference involves the elasticity, or stretchiness, of tissue. By stretching and absorbing energy, the biological matrix constrains
the growth of the micro-explosions. As a result, the explosions tend to be considerably smaller than they are in water. This reduces the damage that t...