1. |
|
|
2. |
- Kimberling, William J., et al.
(author)
-
Localization of Usher syndrome type II to chromosome 1q
- 1990
-
In: Genomics. - : Elsevier BV. - 0888-7543 .- 1089-8646. ; 7:2, s. 245-249
-
Journal article (peer-reviewed)abstract
- Usher syndrome is characterized by congenital hearing loss, progressive visual impairment due to retinitis pigmentosa, and variable vestibular problems. The two subtypes of Usher syndrome, types I and II, can be distinguished by the degree of hearing loss and by the presence or absence of vestibular dysfunction. Type I is characterized by a profound hearing loss and totally absent vestibular responses, while type II has a milder hearing loss and normal vestibular function. Fifty-five members of eight type II Usher syndrome families were typed for three DNA markers in the distal region of chromosome 1q: D1S65 (pEKH7.4), REN (pHRnES1.9), and D1S81 (pTHH33). Statistically significant linkage was observed for Usher syndrome type II with a maximum multipoint lod score of 6.37 at the position of the marker THH33, thus localizing the Usher type II (USH2) gene to 1q. Nine families with type I Usher syndrome failed to show linkage to the same three markers. The statistical test for heterogeneity of linkage between Usher syndrome types I and II was highly significant, thus demonstrating that they are due to mutations at different genetic loci.
|
|
3. |
|
|
4. |
|
|
5. |
|
|
6. |
|
|
7. |
|
|
8. |
- Nilsson, S., et al.
(author)
-
DFB laser with nonuniform coupling coefficient realized by double-layer buried grating
- 1993
-
In: IEEE Photonics Technology Letters. - : Institute of Electrical and Electronics Engineers (IEEE). - 1041-1135 .- 1941-0174. ; 5, s. 1128-1131
-
Journal article (peer-reviewed)abstract
- A technique for the realization of a nonuniform grating coupling coefficient kappa , and its implementation in distributed-feedback (DFB) lasers is presented. This technique, which is an extension of the buried-grating concept, offers precise control of the coupling coefficient and enables a kappa -ratio greater than 10. DFB lasers with an asymmetric kappa -variation have been fabricated using this method. A front-to-rear facet output power ratio close to five was obtained, qualitatively in agreement with simulations.<>
|
|