| 1. |
- Allaria, E., et al.
(författare)
-
Highly coherent and stable pulses from the FERMI seeded free-electron laser in the extreme ultraviolet
- 2012
-
Ingår i: Nature Photonics. - 1749-4885. ; 6:10, s. 699-704
-
Tidskriftsartikel (refereegranskat)abstract
- Free-electron lasers (FELs) are promising devices for generating light with laser-like properties in the extreme ultraviolet and X-ray spectral regions. Recently, FELs based on the self-amplified spontaneous emission (SASE) mechanism have allowed major breakthroughs in diffraction and spectroscopy applications, despite the relatively large shot-to-shot intensity and photon-energy fluctuations and the limited longitudinal coherence inherent in the SASE mechanism. Here, we report results on the initial performance of the FERMI seeded FEL, based on the high-gain harmonic generation configuration, in which an external laser is used to initiate the emission process. Emission from the FERMI FEL-1 source occurs in the form of pulses carrying energy of several tens of microjoules per pulse and tunable throughout the 65 to 20 nm wavelength range, with unprecedented shot-to-shot wavelength stability, low-intensity fluctuations, close to transform-limited bandwidth, transverse and longitudinal coherence and full control of polarization.
|
|
| 2. |
- Sygletos, S., et al.
(författare)
-
Phase locking and carrier extraction schemes for phase sensitive amplification
- 2010
-
Ingår i: 2010 12th International Conference on Transparent Optical Networks, ICTON 2010. - 9781424477975
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- We demonstrate two schemes which enable simultaneous phase locking, carrier extraction and frequency shifting for use in stand-alone phase sensitive amplifiers. The schemes provide phase locked pumps at appropriate frequency spacing for a number of non-degenerate PSA configurations. © 2010 IEEE.
|
|
| 3. |
- Wood, Laura D, et al.
(författare)
-
The genomic landscapes of human breast and colorectal cancers.
- 2007
-
Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 318:5853, s. 1108-1113
-
Tidskriftsartikel (refereegranskat)abstract
- Human cancer is caused by the accumulation of mutations in oncogenes and tumor suppressor genes. To catalog the genetic changes that occur during tumorigenesis, we isolated DNA from 11 breast and 11 colorectal tumors and determined the sequences of the genes in the Reference Sequence database in these samples. Based on analysis of exons representing 20,857 transcripts from 18,191 genes, we conclude that the genomic landscapes of breast and colorectal cancers are composed of a handful of commonly mutated gene "mountains" and a much larger number of gene "hills" that are mutated at low frequency. We describe statistical and bioinformatic tools that may help identify mutations with a role in tumorigenesis. These results have implications for understanding the nature and heterogeneity of human cancers and for using personal genomics for tumor diagnosis and therapy.
|
|
| 4. |
- Ellis, A. D., et al.
(författare)
-
Future Directions to Realize Ultra-High Bit-Rate Transmission Systems
- 2010
-
Ingår i: Proceedings of OptoElectronics and Communications Conference, OECC 2010, Sapporo, Japan, 5-9 July 2010, invited paper..
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In this paper we examine two potential future directions for the realization of ultra-high bit rate transmission systems.
|
|
| 5. |
- Lin, Jimmy, et al.
(författare)
-
A multidimensional analysis of genes mutated in breast and colorectal cancers
- 2007
-
Ingår i: Genome Research. - : Cold Spring Harbor Laboratory. - 1088-9051 .- 1549-5469. ; 17:9, s. 1304-1318
-
Tidskriftsartikel (refereegranskat)abstract
- A recent study of a large number of genes in a panel of breast and colorectal cancers identified somatic mutations in 1149 genes. To identify potential biological processes affected by these genes, we examined their putative roles based on sequence similarity, membership in known functional groups and pathways, and predicted interactions with other proteins. These analyses identified functional groups and pathways that were enriched for mutated genes in both tumor types. Additionally, the results pointed to differences in molecular mechanisms that underlie breast and colorectal cancers, including various intracellular signaling and metabolic pathways. These studies provide a multidimensional framework to guide further research and help identify cellular processes critical for malignant progression and therapeutic intervention.
|
|
| 6. |
- Parmigiani, Francesca, et al.
(författare)
-
All-Optical Phase Regeneration of 40Gbit/s DPSK Signals in a Black‐Box Phase Sensitive Amplifier
- 2010
-
Ingår i: 2010 Conference on Optical Fiber Communication, Collocated National Fiber Optic Engineers Conference, OFC/NFOEC 2010; San Diego, CA; United States; 21 March 2010 through 25 March 2010. - 9781557528841 ; , s. PDPC3-
-
Konferensbidrag (refereegranskat)abstract
- We present a black‐box four wave mixingbased bit‐rate‐flexible phase sensitive amplifier and use it in the first demonstration of 40 Gbit/s DPSK phaseregeneration.
|
|
| 7. |
- Rocha, A. L., et al.
(författare)
-
Enoxacin induces oxidative metabolism and mitigates obesity by regulating adipose tissue miRNA expression
- 2020
-
Ingår i: Science Advances. - : American Association for the Advancement of Science (AAAS). - 2375-2548. ; 6:49
-
Tidskriftsartikel (refereegranskat)abstract
- MicroRNAs (miRNAs) have been implicated in oxidative metabolism and brown/beige adipocyte identity. Here, we tested whether widespread changes in miRNA expression promoted by treatment with the small-molecule enoxacin cause browning and prevent obesity. Enoxacin mitigated diet-induced obesity in mice, and this was associated with increased energy expenditure. Consistently, subcutaneous white and brown adipose tissues and skeletal muscle of enoxacin-treated mice had higher levels of markers associated with thermogenesis and oxidative metabolism. These effects were cell autonomous since they were recapitulated in vitro in m urine and human cell models. In preadipocytes, enoxacin led to a reduction of miR-34a-5p expression and up-regulation of its target genes (e.g., Fgfr1, Klb, and Sirt1), thus increasing FGF21 signaling and promoting beige adipogenesis. Our data demonstrate that enoxacin counteracts obesity by promoting thermogenic signaling and inducing oxidative metabolism in adipose tissue and skeletal muscle in a mechanism that involves, at least in part, miRNA-mediated regulation.
|
|
| 8. |
- Slavík, Radan, et al.
(författare)
-
All-optical phase and amplitude regenerator for next-generation telecommunications systems
- 2010
-
Ingår i: Nature Photonics. - 1749-4885 .- 1749-4893. ; 4:10, s. 690-695
-
Tidskriftsartikel (refereegranskat)abstract
- Fibre-optic communications systems have traditionally carried data using binary (on-off) encoding of the light amplitude. However, next-generation systems will use both the amplitude and phase of the optical carrier to achieve higher spectral efficiencies and thus higher overall data capacities. Although this approach requires highly complex transmitters and receivers, the increased capacity and many further practical benefits that accrue from a full knowledge of the amplitude and phase of the optical field more than outweigh this additional hardware complexity and can greatly simplify optical network design. However, use of the complex optical field gives rise to a new dominant limitation to system performance—nonlinear phase noise. Developing a device to remove this noise is therefore of great technical importance. Here, we report the development of the first practical (‘black-box’) all-optical regenerator capableof removing both phase and amplitude noise from binary phase-encoded optical communications signals.
|
|
| 9. |
|
|
| 10. |
|
|
| 11. |
- Hülsmann, Lisa, et al.
(författare)
-
Latitudinal patterns in stabilizing density dependence of forest communities
- 2024
-
Ingår i: Nature. - 0028-0836 .- 1476-4687. ; 627, s. 564-571
-
Tidskriftsartikel (refereegranskat)abstract
- Numerous studies have shown reduced performance in plants that are surrounded by neighbours of the same species1,2, a phenomenon known as conspecific negative density dependence (CNDD)3. A long-held ecological hypothesis posits that CNDD is more pronounced in tropical than in temperate forests4,5, which increases community stabilization, species coexistence and the diversity of local tree species6,7. Previous analyses supporting such a latitudinal gradient in CNDD8,9 have suffered from methodological limitations related to the use of static data10–12. Here we present a comprehensive assessment of latitudinal CNDD patterns using dynamic mortality data to estimate species-site-specific CNDD across 23 sites. Averaged across species, we found that stabilizing CNDD was present at all except one site, but that average stabilizingCNDD was not stronger toward the tropics. However, in tropical tree communities, rare and intermediate abundant species experienced stronger stabilizing CNDD than did common species. This pattern was absent in temperate forests, which suggests that CNDD influences species abundances more strongly in tropical forests than it does in temperate ones13. We also found that interspecific variation in CNDD, which might attenuate its stabilizing effect on species diversity14,15, was high but not significantly different across latitudes. Although the consequences of these patterns for latitudinal diversity gradients are difficult to evaluate, we speculate that a more effective regulation of population abundances could translate into greater stabilization of tropical tree communities and thus contribute to the high local diversity of tropical forests.
|
|
| 12. |
- Leite, Melina de Souza, et al.
(författare)
-
Major axes of variation in tree demography across global forests
- 2024
-
Ingår i: Ecography. - 0906-7590 .- 1600-0587.
-
Tidskriftsartikel (refereegranskat)abstract
- The future trajectory of global forests is closely intertwined with tree demography, and a major fundamental goal in ecology is to understand the key mechanisms governing spatio-temporal patterns in tree population dynamics. While previous research has made substantial progress in identifying the mechanisms individually, their relative importance among forests remains unclear mainly due to practical limitations. One approach to overcome these limitations is to group mechanisms according to their shared effects on the variability of tree vital rates and quantify patterns therein. We developed a conceptual and statistical framework (variance partitioning of Bayesian multilevel models) that attributes the variability in tree growth, mortality, and recruitment to variation in species, space, and time, and their interactions – categories we refer to as organising principles (OPs). We applied the framework to data from 21 forest plots covering more than 2.9 million trees of approximately 6500 species. We found that differences among species, the species OP, proved a major source of variability in tree vital rates, explaining 28–33% of demographic variance alone, and 14–17% in interaction with space, totalling 40–43%. Our results support the hypothesis that the range of vital rates is similar across global forests. However, the average variability among species declined with species richness, indicating that diverse forests featured smaller interspecific differences in vital rates. Moreover, decomposing the variance in vital rates into the proposed OPs showed the importance of unexplained variability, which includes individual variation, in tree demography. A focus on how demographic variance is organized in forests can facilitate the construction of more targeted models with clearer expectations of which covariates might drive a vital rate. This study therefore highlights the most promising avenues for future research, both in terms of understanding the relative contributions of groups of mechanisms to forest demography and diversity, and for improving projections of forest ecosystems.
|
|
| 13. |
- Liu, S., et al.
(författare)
-
OTDM to WDM format conversion based on cascaded SHG/DFG in a single PPLN waveguide
- 2010
-
Ingår i: Optics InfoBase Conference Papers. - Washington, D.C. : Optical Society of America (OSA).
-
Konferensbidrag (refereegranskat)abstract
- We propose and experimentally demonstrate error-free OTDM to WDM format conversion based on cSHG/DFG within a 30mm-long PPLN waveguide and a time-to-frequency domain conversion approach, which relies upon switching a linearly chirped pulse.
|
|
| 14. |
|
|
| 15. |
|
|
