With the arrival of a cheap and bountiful supply of crude-oil derived sources the need for the sustainable route was deemed unnecessary.
While optogenetics is continuing to enable novel studies that were previously impossible, a number of fundamental limitations exist, including lack of deep tissue penetration using conventional visible light sources, the need for invasive surgeries to deliver light, and difficulties in targeting deeper brain regions [43].
Journalists spoke of common concerns like how to protect one's sources, the need for codes of conduct, and ways to overcome low education and training standards in many countries.
(e) Herder also refers to the second limb of his doctrine of radical difference — individual variations in mode of thought even within a single period and culture — as a source of the need for psychological interpretation.
A flip-mounted mirror enabled the BARD to be used with either light source without the need for realignment of the optical beam path.
The differing strengths of association by fibre type or source highlight the need for a better understanding of the mode of action of fibre components.
Fructobacillus is distinguished from Leuconostoc by the preference for fructose over glucose as the carbon source and the need for an electron acceptor (e.g. pyruvate or oxygen) during glucose assimilation.
The relevant lines are: "The Parties recognize the desirability of a wide variety of sources, public and private, bilateral and multilateral, including alternative sources, noting the need for a diversity of sources and instruments to fit recipients' changing economic circumstances.
The small numbers provided with GWG targets, and the dominance of non-clinical information sources, supports the need for GWG guidance from reputable sources.
According to the official line, new media -- first cable television, then the Internet -- have given the public access to a diversity of news sources, eliminating the need for public guidelines.
