Electronic northern

Mining the extensive soybean EST data using the electronic Northern approach illustrates how information can be inferred about the possible sites of expression of gene family members. Here, we illustrate this approach for a small family of soybean lectins and present new information on the expression patterns of two non-seed lectins. 

The libraries in which either Lei or Le3 were present were grouped by tissues to aid in the electronic northern . The occurrences of Lei and Le3 sequences were counted for each tissue and a normalized value (ESTs per million) was calculated with the following formula (Le ESTs in Library A + Le ESTs in Library B +. ..+ Le ESTs in Library n / ESTs in Library A + ESTs in Library B +. .. + ESTs in Library n) X (1.0 x 10 ) = Expression level in ESTs per million (EPM). 

Figure 9.2 Electronic northern histogram of Lei and Le3 expression patterns. Lei (first darker bar), is expressed in cotyledons of the seeds, and /.ci (second, ligliter bar) in nonseed tissues. Root is included to illustrate that neither /, / nor Le3 are expressed in roots.

The electronic northerns are a semi-quantitative, first approximation of expression levels in various tissues. They are more accurate when the input data are from non-nonnalized cDNA libraries, the database is large, and most libraries have been sequenced relatively deeply. Microarrays provide a method to quantify relative gene expression in RNA samples by dual labeling with fluorescent dyes. They also enable the simultaneous comparisons of expression levels of thousands of genes at the same time. Genes that respond in a similar developmental manner and/or to the same stress or environmental conditions can be determined. Below, we illustrate the power of microarrays to reveal information on networks of pathways that operate during the induction of somatic embryos on tissue culture media. 

The market for optical fiber worldwide in 1992 was 2.8 billion corresponding to 10 million fiber kilometers (Mfk) (38). This can be broken down into the U.S. market (3.7 Mfk), the rest of North America (0.4 Mfk), northern Europe (4.1 Mfk), eastern Europe (2.6 Mfk), the Pacific Rim (2.8 Mfk), and elsewhere (0.3 Mfk). Most of the optical fiber is manufactured by only a few companies, the largest of which are AT T and Coming. Other producers include Alcatel, Eujikura, Eurakawa, Northern Telecom, Pirelli, and Sumitomo. The market for optical fibers is projected to reach 3.5 biUion by 1998. In addition, according to ElectroniCast (San Mateo, Ca.), the total market for passive optical components, optical electronics, connectors, and fiber-optic cable is predicted to increase from 1.76 billion (U.S.) in 1992 to over 4 billion in 1997, and 10 billion by 2002. 

Blum et al. (1998) isolated a bacterial strain Bacillus arsenicoselenatis from muds of Mono Lake, ahypersaline alkaline lake in northern California (see Section 24.2). Under anaerobic conditions in saline water, over an optimum pH range of 8.5-10, the strain can respire using As(V), or arsenate, as the electron acceptor, reducing it to As(III), arsenite. 

Today, scientists explain the northern lights as resulting from streams of protons and electrons—plasma—emanating from the Sun. When the electrons from the plasma interact with gaseous atoms in Earth s upper atmosphere, the atoms emit coloured light. 

The green colours in the northern lights come from the interaction of accelerated electrons with oxygen atoms. The red colours usually come from nitrogen atoms. How do these interactions lead to atoms of different elements emitting light with characteristic wavelengths ... 

The electronic equipment used is now commercially available from three or four sources. Ours consisted of a Nuclear Science Instruments Mossbauer spectrometer and a Northern Scientific pulse height analyzer. The spectra we obtained were all fitted (by least squares) by an IBM 360 computer (7) used in a time-shared system. Plots were also computer-produced. All of our spectra, whether obtained by transmission or by scattering, are shown with the ordinate as fractional absorption relative to the off-peak background. 

Naval Research Laboratory, 626 Northern Illinois University, 258,661 Northwestern University, 226,294 NTT Opto-electronics Laboratories, 704 Pennsylvania State University, 258,605... 

Northern Ireland Whitehall, GB Applicant Philips Electronic and Associated ... 

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