For each symbiont three markers were used to identify intraspecific variation (mycobiont ITS, mtSSU, RPB1; photobiont ITS, psbJ-L, COX2). For the mycobiont, the saxicolous genera Lecidea, Porpidia, Poeltidea and Lecidella were phylogenetically re-evaluated, along with their photobionts Asterochloris and Trebouxia. For several globally distributed species groups, the results show geographically highly differentiated subclades, classified as operational taxonomical units (OTUs), which were assigned to the different regions of southern South America (sSA). Furthermore, several small endemic and well-supported clades apparently restricted to sSA were detected at the species level for both symbionts.Lichens are widely acknowledged to be a key component of high latitude ecosystems. However, the time investment needed for full inventories and the lack of taxonomic identification resources for crustose lichen and lichenicolous fungal diversity have hampered efforts to fully gauge the depth of species richness in these ecosystems. Using a combination of classical field inventory and extensive deployment of chemical and molecular analysis, we assessed the diversity of lichens and associated fungi in Glacier Bay National Park, Alaska (USA), a mixed landscape of coastal boreal rainforest and early successional low elevation habitats deglaciated after the Little Ice Age. We collected nearly 5000 specimens and found a total of 947 taxa, including 831 taxa of lichen-forming and 96 taxa of lichenicolous fungi together with 20 taxa of saprotrophic fungi typically included in lichen studies. A total of 98 species (10.3% of those detected) could not be assigned to known species and of those, two genera and 27 species l taxa new to Alaska. We use four to eight DNA loci to validate the placement of ten of the new species in the orders Baeomycetales, Ostropales, Lecanorales, Peltigerales, Pertusariales and the broader class Lecanoromycetes with maximum likelihood analyses. We present a total of 280 new fungal DNA sequences. The lichen inventory from Glacier Bay National Park represents the second largest number of lichens and associated fungi documented from an area of comparable size and the largest to date in North America. Coming from almost 60°N, these results again underline the potential for high lichen diversity in high latitude ecosystems.The performance of an ultra-compact all-optical D flip-flop using photonic crystal waveguides is numerically analyzed and examined by optimized parameters such as refractive index and silicon rod radius. In the field of optical networking and computing, flip-flops are used to reduce the complexity of digital circuits. The phenomenon of optical interference effect is used to implement a D flip-flop at a wavelength of 1550 nm. This structure is designed using T-shaped waveguides without using non-linear material. The proposed design is small, has low insertion losses of 0.087 dB when operated at low power level, and provides high contrast ratio of 25 dB and transmission ratio of more than 96%.We demonstrated a single-shot, multispectral birefringence mapping by use of a supercontinuum (SC) vector beam. The vector beam, which was generated by a pair of axially symmetric wave plates, leads to angular-variant polarization modulation to divide birefringence properties of a sample substrate into Fourier space. This strategy allows multispectral birefringence mapping from a single-shot image captured by a multispectral imaging detector. For SC vector beam analysis, we also compensated the retardance error of the axially symmetric wave plate in the superbroadband spectrum. Resolutions of retardance and azimuthal angle were 0.4° and 0.2°, respectively, and the spatial resolution was 60 µm. Those results are expected to provide us a single-shot, multispectral birefringence mapping with high spatial resolution as compared with using a scanning laser microscope. Our proposal has extendibility to develop high-speed, high-resolution birefringence imaging spectroscopy.We describe a monolithic approach to fabricating large-scale arrays of high-finesse and low-mode-volume Fabry-Perot microcavities with open access to the air core. A stress-driven buckling self-assembly technique was used to form half-symmetric curved-mirror cavities, and a dry etching process was subsequently used to create micropores through the upper mirror. We show that the cavities retain excellent optical properties, with reflectance-limited finesse ∼2500 and highly predictable Laguerre-Gaussian modes. We furthermore demonstrate the ability to introduce liquids into the cavity region by microinjection through the pores. https://www.selleckchem.com/products/mm3122.html Applications in sensing, optofluidics, and cavity quantum electrodynamics are envisioned.We propose a comprehensive point spread function (PSF) degradation model, which considers multiple factors consisting of degradation of specimen retardant sampling and polarization angularly anamorphic sampling, to indicate the image degradation characteristics of polarization imaging systems. First, a one-layer optical coherence tomography (OCT) model was established to express the retardancy of medium-loading specimens. Then, a PSF degradation model of angularly anamorphic polarization sampling was deduced through the retrieval of Stokes parameters. Finally, maximum a posteriori probability (MAP) was adopted to assess the distribution of the proposed model. Hypothesis testing using actual data and numerical simulations demonstrated that the error of the system followed an asymmetric generalized Gaussian distribution (AGGD). Finite-difference time-domain (FDTD) simulation results and an actual imaging experiment demonstrate the consistency of the proposed model and the degradation characteristics of the PSF, which provide support for the improved accuracy and enhanced image quality of the optical field retrieval of nanoparticles.A decoding scheme based on a convolution neural network (CNN) is proposed and experimentally demonstrated in mobile optical camera communication (OCC). The CNN can be used to extract features between bright and dark stripes in images effectively. Thus, it can alleviate the stripe distortion in the mobile environment and reduce bit error rates (BERs) by using the proposed decoding scheme based on CNN. A controllable lateral and vertical mobile platform is built to simulate the mobile scenarios with different moving speeds (40-80 cm/s). The experimental results show that, at the moving speed of 80 cm/s, the proposed scheme based on CNN can achieve the BERs of 3.8×10-5 at the lateral case and 1×10-5 at the vertical case in a mobile OCC system.
For each symbiont three markers were used to identify intraspecific variation (mycobiont ITS, mtSSU, RPB1; photobiont ITS, psbJ-L, COX2). For the mycobiont, the saxicolous genera Lecidea, Porpidia, Poeltidea and Lecidella were phylogenetically re-evaluated, along with their photobionts Asterochloris and Trebouxia. For several globally distributed species groups, the results show geographically highly differentiated subclades, classified as operational taxonomical units (OTUs), which were assigned to the different regions of southern South America (sSA). Furthermore, several small endemic and well-supported clades apparently restricted to sSA were detected at the species level for both symbionts.Lichens are widely acknowledged to be a key component of high latitude ecosystems. However, the time investment needed for full inventories and the lack of taxonomic identification resources for crustose lichen and lichenicolous fungal diversity have hampered efforts to fully gauge the depth of species richness in these ecosystems. Using a combination of classical field inventory and extensive deployment of chemical and molecular analysis, we assessed the diversity of lichens and associated fungi in Glacier Bay National Park, Alaska (USA), a mixed landscape of coastal boreal rainforest and early successional low elevation habitats deglaciated after the Little Ice Age. We collected nearly 5000 specimens and found a total of 947 taxa, including 831 taxa of lichen-forming and 96 taxa of lichenicolous fungi together with 20 taxa of saprotrophic fungi typically included in lichen studies. A total of 98 species (10.3% of those detected) could not be assigned to known species and of those, two genera and 27 species l taxa new to Alaska. We use four to eight DNA loci to validate the placement of ten of the new species in the orders Baeomycetales, Ostropales, Lecanorales, Peltigerales, Pertusariales and the broader class Lecanoromycetes with maximum likelihood analyses. We present a total of 280 new fungal DNA sequences. The lichen inventory from Glacier Bay National Park represents the second largest number of lichens and associated fungi documented from an area of comparable size and the largest to date in North America. Coming from almost 60°N, these results again underline the potential for high lichen diversity in high latitude ecosystems.The performance of an ultra-compact all-optical D flip-flop using photonic crystal waveguides is numerically analyzed and examined by optimized parameters such as refractive index and silicon rod radius. In the field of optical networking and computing, flip-flops are used to reduce the complexity of digital circuits. The phenomenon of optical interference effect is used to implement a D flip-flop at a wavelength of 1550 nm. This structure is designed using T-shaped waveguides without using non-linear material. The proposed design is small, has low insertion losses of 0.087 dB when operated at low power level, and provides high contrast ratio of 25 dB and transmission ratio of more than 96%.We demonstrated a single-shot, multispectral birefringence mapping by use of a supercontinuum (SC) vector beam. The vector beam, which was generated by a pair of axially symmetric wave plates, leads to angular-variant polarization modulation to divide birefringence properties of a sample substrate into Fourier space. This strategy allows multispectral birefringence mapping from a single-shot image captured by a multispectral imaging detector. For SC vector beam analysis, we also compensated the retardance error of the axially symmetric wave plate in the superbroadband spectrum. Resolutions of retardance and azimuthal angle were 0.4° and 0.2°, respectively, and the spatial resolution was 60 µm. Those results are expected to provide us a single-shot, multispectral birefringence mapping with high spatial resolution as compared with using a scanning laser microscope. Our proposal has extendibility to develop high-speed, high-resolution birefringence imaging spectroscopy.We describe a monolithic approach to fabricating large-scale arrays of high-finesse and low-mode-volume Fabry-Perot microcavities with open access to the air core. A stress-driven buckling self-assembly technique was used to form half-symmetric curved-mirror cavities, and a dry etching process was subsequently used to create micropores through the upper mirror. We show that the cavities retain excellent optical properties, with reflectance-limited finesse ∼2500 and highly predictable Laguerre-Gaussian modes. We furthermore demonstrate the ability to introduce liquids into the cavity region by microinjection through the pores. https://www.selleckchem.com/products/mm3122.html Applications in sensing, optofluidics, and cavity quantum electrodynamics are envisioned.We propose a comprehensive point spread function (PSF) degradation model, which considers multiple factors consisting of degradation of specimen retardant sampling and polarization angularly anamorphic sampling, to indicate the image degradation characteristics of polarization imaging systems. First, a one-layer optical coherence tomography (OCT) model was established to express the retardancy of medium-loading specimens. Then, a PSF degradation model of angularly anamorphic polarization sampling was deduced through the retrieval of Stokes parameters. Finally, maximum a posteriori probability (MAP) was adopted to assess the distribution of the proposed model. Hypothesis testing using actual data and numerical simulations demonstrated that the error of the system followed an asymmetric generalized Gaussian distribution (AGGD). Finite-difference time-domain (FDTD) simulation results and an actual imaging experiment demonstrate the consistency of the proposed model and the degradation characteristics of the PSF, which provide support for the improved accuracy and enhanced image quality of the optical field retrieval of nanoparticles.A decoding scheme based on a convolution neural network (CNN) is proposed and experimentally demonstrated in mobile optical camera communication (OCC). The CNN can be used to extract features between bright and dark stripes in images effectively. Thus, it can alleviate the stripe distortion in the mobile environment and reduce bit error rates (BERs) by using the proposed decoding scheme based on CNN. A controllable lateral and vertical mobile platform is built to simulate the mobile scenarios with different moving speeds (40-80 cm/s). The experimental results show that, at the moving speed of 80 cm/s, the proposed scheme based on CNN can achieve the BERs of 3.8×10-5 at the lateral case and 1×10-5 at the vertical case in a mobile OCC system.
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