Interpolating between periodicity and discreteness through the fractional Fourier transform

Cataloged from PDF version of article.Periodicity and discreteness are Fourier duals in the same sense as operators such as coordinate multiplication and differentiation, and translation and phase shift. The fractional Fourier transform allows interpolation between such operators which gradually evolve from one member of the dual pair to the other as the fractional order goes from zero to one. Here, we similarly discuss the interpolation between the dual properties of periodicity and discreteness, showing how one evolves into the other as the order goes from zero to one. We also discuss the concepts of partial discreteness and partial periodicity and relate them to fractional discreteness and periodicity

Whole-body tissue stabilization and selective extractions via tissue-hydrogel hybrids for high-resolution intact circuit mapping and phenotyping

To facilitate fine-scale phenotyping of whole specimens, we describe here a set of tissue fixation-embedding, detergent-clearing and staining protocols that can be used to transform excised organs and whole organisms into optically transparent samples within 1–2 weeks without compromising their cellular architecture or endogenous fluorescence. PACT (passive CLARITY technique) and PARS (perfusion-assisted agent release in situ) use tissue-hydrogel hybrids to stabilize tissue biomolecules during selective lipid extraction, resulting in enhanced clearing efficiency and sample integrity. Furthermore, the macromolecule permeability of PACT- and PARS-processed tissue hybrids supports the diffusion of immunolabels throughout intact tissue, whereas RIMS (refractive index matching solution) grants high-resolution imaging at depth by further reducing light scattering in cleared and uncleared samples alike. These methods are adaptable to difficult-to-image tissues, such as bone (PACT-deCAL), and to magnified single-cell visualization (ePACT). Together, these protocols and solutions enable phenotyping of subcellular components and tracing cellular connectivity in intact biological networks

Reconstructing neuronal anatomy from whole-brain images

Reconstructing multiple molecularly defined neurons from individual brains and across multiple brain regions can reveal organizational principles of the nervous system. However, high resolution imaging of the whole brain is a technically challenging and slow process. Recently, oblique light sheet microscopy has emerged as a rapid imaging method that can provide whole brain fluorescence microscopy at a voxel size of 0.4\times 0.4\times 2.5\mu \mathrm{m}^{3}. On the other hand, complex image artifacts due to whole-brain coverage produce apparent discontinuities in neuronal arbors. Here, we present connectivity-preserving methods and data augmentation strategies for supervised learning of neuroanatomy from light microscopy using neural networks. We quantify the merit of our approach by implementing an end-to-end automated tracing pipeline. Lastly, we demonstrate a scalable, distributed implementation that can reconstruct the large datasets that sub-micron whole-brain images produce. © 2019 IEEE

Fatty Acid Profile and Biological Data of Four Endemic Cephalaria Species Grown in Turkey

WOS: 000299683800008The fatty acid compositions of the n-hexane extracts of the aerial parts of four Turkish Cephalaria species (C. paphlagonica, C. stellipilis, C. davisiana and C. elazigensis var. purpurea) were analyzed by GC-MS for the first time. The oil yields of these species were determined as ranging from 0.07% to 0.36 %. Seventeen fatty acids as methyl esters were identified. All extracts were found to contain significant quantities of palmitic, linoleic (LA), stearic and alpha-linolenic acid (ALA). ALA was the most abundant fatty acid in all species (29.00%, 30.51%, 32.49% and 34.87% for C. stellipilis, C. elazigensis, C. davisiana and C. paphlagonica, respectively). Other dominant fatty acid was palmitic acid, which ranged from 19.10% to 28.23% for all species. LA was detected in a considerable amount of 19.44 % for C. paphlagonica. The n-hexane extracts of the plants were also checked for their antimicrobial and antioxidant activities.TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [107T028]The authors acknowledge to TUBITAK for financial support (107T028) and also Hygiene Center of Izmir for GC-MS analyses