222 research outputs found
Comparative gene mapping in Arabidopsis lyrata chromosomes 1 and 2 and the corresponding A. thaliana chromosome 1: recombination rates, rearrangements and centromere location
Improvements in diffraction efficiency of gratings and microlenses with continuous relief structures
Multiple self-healing Bloch surface wave beams generated by a two-dimensional fraxicon
Two-dimensional surface waves are a cornerstone for future integrated photonic circuits. They can also be beneficially exploited in sensing devices by offering dark-field illuminations of objects. One major problem in sensing schemes arises from the individual sensing objects: the interaction of surface waves with an object reduces the field amplitude, and the readout of other objects along the propagation path suffers from this reduced signal. Here we show in two experiments that nondiffracting and self-healing Bloch surface waves can be launched using a Fresnel axicon (i.e., fraxicon). First, we visualize the generation of an array of multiple focal spots by scanning near-field optical microscopy in the infrared. With a second device operating in the visible, we demonstrate the self-healing effect directly using a far-field readout method by placing metallic nanoantennas onto the multiple focal spots of the fraxicon. Our study extends the versatile illumination capabilities of surface wave systems
Studying genetics of adaptive variation in model organisms: flowering time variation in Arabidopsis lyrata
Arabidopsis thaliana has emerged as a model organism for plant developmental genetics, but it is also now being widely used for population genetic studies. Outcrossing relatives of A. thaliana are likely to provide suitable additional or alternative species for studies of evolutionary and population genetics. We have examined patterns of adaptive flowering time variation in the outcrossing, perennial A. lyrata. In addition, we examine the distribution of variation at marker genes in populations form North America and Europe. The probability of flowering in this species differs between southern and northern populations. Northern populations are much less likely to flower in short than in long days. A significant daylength by region interaction shows that the northern and southern populations respond differently to the daylength. The timing of flowering also differs between populations, and is made shorter by long days, and in some populations, by vernalization. North American and European populations show consistent genetic differentiation over microsatellite and isozyme loci and alcohol dehydrogenase sequences. Thus, the patterns of variation are quite different from those in A. thaliana, where flowering time differences show little relationship to latitude of origin and the genealogical trees of accessions vary depending on the genomic region studied. The genetic architecture of adaptation can be compared in these species with different life historie
Diffractive beamshaping elements at the fabrication limit
We treat the generation of flat-top intensity distributions, as required for laser applications at short wavelengths. To obtain high fill factors and almost arbitrary shapes, arrays of diffractive Fresnel zone plates at the fabrication limit are investigated. The angular power spectrum noise due to the binarization of the transmission phase function is smoothed using an incoherent source. The remaining zeroth order is ommited by the addition of a constant offset phase to the transmission phase function of the array. An analysis of etch-depth errors as well as an investigation of multilevel elements is appended. Simulation results, obtained by a 2-D analysis for radial symmetry, are compared to measurements. © 1996 Society of Photo-Optical Instrumentation Engineers
Nanostructured surface fabricated by laser interference lithography to attenuate the reflectivity of microlens arrays
A subwavelength-scale square lattice optical nanostructure is fabricated using an interference photolithography process on the surface of a quartz microlens array. This nanostructuring of the quartz surface introduces an antireflective effect, reducing reflectivity between 10% and 30% and enhancing the transmissivity 3% in the visible spectrum. This approach permits fast fabrication on a 4-inch wafer covered with microlenses (non-flat surface) and produces monolithic devices which are robust to adverse environments such as temperature variations. [DOI: 10.2971/jeos.2010.10006
Diffractive elements designed to suppress unwanted zeroth order due to surface depth error
CD34+ cell mobilization, blood graft composition, and posttransplant recovery in myeloma patients compared to nonâHodgkinÊŒs lymphoma patients: results of the prospective multicenter GOA study
BACKGROUNDAutologous stem cell transplantation is an established treatment option for patients with multiple myeloma (MM) or nonâHodgkinÊŒs lymphoma (NHL).STUDY DESIGN AND METHODSIn this prospective multicenter study, 147 patients with MM were compared with 136 patients with NHL regarding the mobilization and apheresis of blood CD34+ cells, cellular composition of infused blood grafts, posttransplant recovery, and outcome.RESULTSMultiple myeloma patients mobilized CD34+ cells more effectively (6.3âĂâ106/kg vs. 3.9âĂâ106/kg, pâ=â0.001). The proportion of poor mobilizers (peak blood CD34+ cell count 100âdays) nonrelapse mortality (NRM; 6% vs. 0%, pâ=â0.003).CONCLUSIONSNonâHodgkinÊŒs lymphoma and MM patients differ in terms of mobilization of CD34+ cells, graft cellular composition, and posttransplant recovery. Thus, the optimal graft characteristics may also be different.</p
Detailed Long-Term Follow-Up of Patients Who Relapsed After the Nordic Mantle Cell Lymphoma Trials : MCL2 and MCL3
Mantle cell lymphoma (MCL) is an incurable disease with a highly variable clinical course. The prognosis after relapse is generally poor, and no standard of care exists. We investigated the postrelapse outcomes of 149 patients who were initially treated in the Nordic Lymphoma Group trials, MCL2 or MCL3, both representing intensive cytarabine-containing frontline regimens including autologous stem cell transplant. Patients with progression of disease before 24 months (POD24, n = 51, 34%) displayed a median overall survival of 6.6 months compared with 46 months for patients with later POD (n = 98, 66%; P < 0.001). MCL international prognostic index, cell proliferation marker, blastoid morphology, and TP53 mutations showed independent prognostic value irrespective of POD24, and in a combined, exploratory risk score, patients with 0, 1, 2-3, or 4-5 high-risk markers, respectively, displayed a 5-year overall survival of 62%, 39%, 31%, and 0%. By a comparison of median progression-free survival of the different salvage therapies in the relapse setting, bendamustine-rituximab was superior to all other combination chemotherapy regimens; however, it was also associated with longer responses to last line of therapy. Collectively, we confirm the prognostic impact of POD24 and highlight the relevance of other biomarkers, and we emphasize the importance of novel therapies for patients with high-risk features at first POD.Peer reviewe
- âŠ