| 1. |
- Clark, Andrew G., et al.
(författare)
-
Evolution of genes and genomes on the Drosophila phylogeny
- 2007
-
Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 450:7167, s. 203-218
-
Tidskriftsartikel (refereegranskat)abstract
- Comparative analysis of multiple genomes in a phylogenetic framework dramatically improves the precision and sensitivity of evolutionary inference, producing more robust results than single-genome analyses can provide. The genomes of 12 Drosophila species, ten of which are presented here for the first time (sechellia, simulans, yakuba, erecta, ananassae, persimilis, willistoni, mojavensis, virilis and grimshawi), illustrate how rates and patterns of sequence divergence across taxa can illuminate evolutionary processes on a genomic scale. These genome sequences augment the formidable genetic tools that have made Drosophila melanogaster a pre-eminent model for animal genetics, and will further catalyse fundamental research on mechanisms of development, cell biology, genetics, disease, neurobiology, behaviour, physiology and evolution. Despite remarkable similarities among these Drosophila species, we identified many putatively non-neutral changes in protein-coding genes, non-coding RNA genes, and cis-regulatory regions. These may prove to underlie differences in the ecology and behaviour of these diverse species.
|
|
| 2. |
- Fu, Hongyan, et al.
(författare)
-
High-Frequency Fiber Bragg Grating Sensing Interrogation System Using Sagnac-Loop-Based Microwave Photonic Filtering
- 2009
-
Ingår i: IEEE Photonics Technology Letters. - : Institute of Electrical and Electronics Engineers (IEEE). - 1041-1135 .- 1941-0174. ; 21:8, s. 519-521
-
Tidskriftsartikel (refereegranskat)abstract
- A novel high-frequency fiber Bragg grating (FBG) sensing interrogation system by using fiber Sagnac-loop-based microwave photonic filtering is proposed and experimentally demonstrated. By adopting the microwave photonic filtering, the wavelength shift of sensing FBG can be converted into amplitude variation of the modulated electronic radio-frequency (RF) signal. In the experiment, the strain applied onto the sensing FBG has been demodulated by measuring the intensity of the recovered RF signal, and by modulating the RF signal with different frequencies, different interrogation sensitivities can be achieved.
|
|
| 3. |
- Zhang, Shu-sheng, et al.
(författare)
-
Plasminogen activator Pla of Yersinia pestis utilizes murine DEC-205 (CD205) as a receptor to promote dissemination
- 2008
-
Ingår i: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 283:46, s. 31511-21
-
Tidskriftsartikel (refereegranskat)abstract
- Yersinia pestis, a Gram-negative bacterium that causes bubonic and pneumonic plague, is able to rapidly disseminate to other parts of its mammalian hosts. Y. pestis expresses plasminogen activator (PLA) on its surface, which has been suggested to play a role in bacterial dissemination. It has been speculated that Y. pestis hijacks antigen-presenting cells, such as macrophages (MPhis) and dendritic cells, to be delivered to lymph nodes to initiate dissemination and infection. Both alveolar MPhis and pulmonary dendritic cells express a C-type lectin receptor, DEC-205 (CD205), which mediates antigen uptake and presentation. However, no ligand has been identified for DEC-205. In this study, we show that the invasion of alveolar MPhisby Y. pestis depends both in vitro and in vivo on the expression of PLA. DEC-205-expressing MPhis and transfectants, but not their negative counterparts, phagocytosed PLA-expressing Y. pestis and Escherichia coli K12 more efficiently than PLA-negative controls. The interactions between PLA-expressing bacteria and DEC-205-expressing transfectants or alveolar MPhis could be inhibited by an anti-DEC-205 antibody. Importantly, the blockage of the PLA-DEC-205 interaction reduced the dissemination of Y. pestis in mice. In conclusion, murine DEC-205 is a receptor for PLA of Y. pestis, and this host-pathogen interaction appears to play a key role in promoting bacterial dissemination.
|
|
| 4. |
- Zhang, Yang-Fei, et al.
(författare)
-
Study on the Viscoelastic Properties of the Epoxy Surface by means of Nano-Dynamic Mechanical Analysis
- 2008
-
Ingår i: Journal of Polymer Science Part B. - : Wiley periodicals, Inc.. - 0887-6266 .- 1099-0488. ; 46:3, s. 281-288
-
Tidskriftsartikel (refereegranskat)abstract
- The viscoelastic properties of the epoxy surface have been investigated by nano-dynamic mechanical analysis (nano-DMA). Both a Berkovich tip and a conospherical tip were used under the condition of different forces (i.e. different penetration depths) in the frequency range of 10–200 Hz. Loss tangent and storage modulus are characteristics that describe the viscoelastic properties. The effect of force frequency, penetration depth and tip shape on the viscoelastic properties is studied and discussed according to the features of microstructures and mobility of molecular chains. The experimental results show important variations when the penetration depth is shallow (<30 nm). As the depth becomes deeper, the results tend to be stable and become almost constant over 120nm. The two kinds of indenter tip can cause a slight difference of the storage modulus. A “master curve” of the storage modulus as a function of force frequency is established.
|
|
| 5. |
- Baldock, Paul A., et al.
(författare)
-
Novel role of Y1 receptors in the coordinated regulation of bone and energy homeostasis
- 2007
-
Ingår i: Journal of Biological Chemistry. - 1083-351X .- 0021-9258. ; 282:26, s. 19092-19102
-
Tidskriftsartikel (refereegranskat)abstract
- The importance of neuropeptide Y (NPY) and Y2 receptors in the regulation of bone and energy homeostasis has recently been demonstrated. However, the contributions of the other Y receptors are less clear. Here we show that Y1 receptors are expressed on osteoblastic cells. Moreover, bone and adipose tissue mass are elevated in Y1(-/-) mice with a generalized increase in bone formation on cortical and cancellous surfaces. Importantly, the inhibitory effects of NPY on bone marrow stromal cells in vitro are absent in cells derived from Y1(-/-) mice, indicating a direct action of NPY on bone cells via this Y receptor. Interestingly, in contrast to Y2 receptor or germ line Y1 receptor deletion, conditional deletion of hypothalamic Y1 receptors in adult mice did not alter bone homeostasis, food intake, or adiposity. Furthermore, deletion of both Y1 and Y2 receptors did not produce additive effects in bone or adiposity. Thus Y1 receptor pathways act powerfully to inhibit bone production and adiposity by nonhypothalamic pathways, with potentially direct effects on bone tissue through a single pathway with Y2 receptors.
|
|
| 6. |
|
|
| 7. |
- Fu, Hongyan, et al.
(författare)
-
Transversal Loading Sensor Based on Tunable Beat Frequency of a Dual-Wavelength Fiber Laser
- 2009
-
Ingår i: IEEE Photonics Technology Letters. - : Institute of Electrical and Electronics Engineers (IEEE). - 1041-1135 .- 1941-0174. ; 21:14, s. 987-989
-
Tidskriftsartikel (refereegranskat)abstract
- Microwave signal generation by using the photonic beating from a phase-shift fiber Bragg grating (PS-FBG)-based dual-wavelength laser is proposed and experimentally demonstrated. The dual-wavelength laser is formed by a linear cavity, in which a PS-FBG is used as a dual-wavelength selective component. Transversal loading on the PS-FBG enhances the birefringence of the optical fiber and consequently makes the transmission peak of the PS-FBG splitting into two sharp transmission peaks of orthogonal polarizations. The wavelength spacing between the two transmission peaks increases with the transversal loading on the PS-FBG, thus making the polarization beating frequency increase. This property is exploited in a transversal loading sensor.
|
|
| 8. |
- Sodergren, Erica, et al.
(författare)
-
The genome of the sea urchin Strongylocentrotus purpuratus.
- 2006
-
Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 1095-9203 .- 0036-8075. ; 314:5801, s. 941-52
-
Tidskriftsartikel (refereegranskat)abstract
- We report the sequence and analysis of the 814-megabase genome of the sea urchin Strongylocentrotus purpuratus, a model for developmental and systems biology. The sequencing strategy combined whole-genome shotgun and bacterial artificial chromosome (BAC) sequences. This use of BAC clones, aided by a pooling strategy, overcame difficulties associated with high heterozygosity of the genome. The genome encodes about 23,300 genes, including many previously thought to be vertebrate innovations or known only outside the deuterostomes. This echinoderm genome provides an evolutionary outgroup for the chordates and yields insights into the evolution of deuterostomes.
|
|
| 9. |
- Wei, Jian-Feng, et al.
(författare)
-
Formation of Kv2.1-FAK complex as a mechanism of FAK activation, cell polarization and enhanced motility
- 2008
-
Ingår i: Journal of Cellular Physiology. - : Wiley. - 0021-9541 .- 1097-4652. ; 217:2, s. 544-557
-
Tidskriftsartikel (refereegranskat)abstract
- Focal adhesion kinase (FAK) plays key roles in cell adhesion and migration. We now report that the delayed rectifier Kv2.1 potassium channel, through its LD-like motif in N-terminus, may interact with FAK and enhance phosphorylation of FAK(397) and FAK(576/577) Overlapping distribution of Kv2.1 and FAK was observed on soma and proximal dendrites of cortical neurons. FAK expression promotes a polarized membrane distribution of the Kv2.1 channel. In Kv2.1-transfected CHO cells, formation of the Kv2.1-FAK complex was stimulated by fibronectin/integrin and inhibited by the K channel blocker tetraethylammonium (TEA). FAK phosphorylation was minimized by shRNA knockdown of the Kv2.1 channel, point mutations of the N-terminus, and TEA, respectively. Cell migration morphology was altered by Kv2.1 knockdown or TEA, hindering cell migration activity. In wound healing tests in vitro and a traumatic injury animal model, Kv2.1 expression and co-localization of Kv2.1 and FAK significantly enhanced directional cell migration and wound closure. It is suggested that the Kv2.1 channel may function as a promoting signal for FAK activation and cell motility.
|
|
| 10. |
|
|
