This paper presents the fundamental principles and recent advances in the field of photonic filtering of microwave signals using discrete-time incoherent processing. We also provide a comprehensive ...review of the fundamentals, applications, and current state of the art.
We consider a concept of angle in normed spaces which preserves isosceles orthogonality and approximate isosceles orthogonality and then we investigate linear mappings which approximately preserve ...such an angle. We show that such mappings are approximate similarities thus they are continuous and bounded below. We also state some results related to conformality and approximate conformality in normed spaces. In particular, an equivalent definition for conformality of mappings defined between inner product spaces is obtained from the methods developed in the paper. Finally, we pay attention to modular mappings defined between inner product
C
∗
-modules over standard algebras with the property of approximately orthogonality preserving and study approximate conformality for such mappings.
Diabetes mellitus is a multiorgan systemic disease impacting numerous ocular structures that results in significant ocular morbidity and often results in more frequent corneal and glaucoma surgeries ...for affected individuals. We hypothesize that the systemic metabolic and proteomic derangement observed in the progression of diabetes influences the composition of the aqueous humor (AH), which ultimately impacts the anterior segment health of the eye. To identify changes associated with diabetes progression, we mapped the metabolite profile and proteome of AH samples from patients with varying severities of type II diabetes (T2DM). Patients were classified as nondiabetic (ND or control), non-insulin-dependent diabetic without advanced features of disease (NAD-ni), insulin-dependent diabetic without advanced features (NAD-i), or diabetic with advanced features (AD). AH samples collected from the anterior chamber during elective ophthalmic surgery were evaluated for metabolite and protein expression changes associated with diabetic severity via gas chromatography/mass spectrometry and ultra-high performance liquid chromatography tandem mass spectrometry, respectively. Metabolic and proteomic pathway analyses were conducted utilizing MetaboAnalyst 4.0 and Ingenuity Pathway Analysis. A total of 14 control, 12 NAD-ni, 4 NAD-I, and 14 AD samples were included for analysis. Elevated levels of several branched amino acids (e.g., valine, leucine, isoleucine), and lipid metabolites (e.g., palmitate) were found only with increasing diabetic severity (i.e., the AD group). Similar proteomic trends were noted in amino acid and fatty acid metabolism and the unfolded protein/stress response. These results represent the first report of both metabolomic and proteomic evaluation of aqueous humor. Diabetes results in metabolic and proteomic perturbations detectable in the AH, and unique changes become manifest as T2DM severity worsens. Changes in AH composition may serve as an indicator of disease severity, risk assessment of anterior segment cells and structures, and potential future therapies.
We propose and experimentally demonstrate new architectures to realize multi-tap microwave photonic filters, based on the generation of a single or multiple dynamic Brillouin gratings in polarization ...maintaining fibers. The spectral range and selectivity of the proposed periodic filters is extensively tunable, simply by reconfiguring the positions and the number of dynamic gratings along the fiber respectively. In this paper, we present a complete analysis of three different configurations comprising a microwave photonic filter implementation: a simple notch-type Mach-Zehnder approach with a single movable dynamic grating, a multi-tap performance based on multiple dynamic gratings and finally a stationary grating configuration based on the phase modulation of two counter-propagating optical waves by a common pseudo-random bit sequence (PRBS).
In the tropics, highly weathered soils with high phosphorus (P) fixation capacities predominate, reducing the P availability to plants. For this reason, understanding the cycle of P in the soil is ...important to develop management strategies that increase P availability to plants, especially in low-input production systems. The aim of this study was to apply structural equation modeling with latent variables, at an exploratory level, to test hypothetical models of the P cycle using data from the Hedley extraction method. Specifically, we evaluated interactions between the pools of P, and identified which pools act as a sink or source of P in unfertilized soils. The models of the P cycle for the tested soil were able to distinguish between the direct and indirect effects of labile and stable P on the available P pool. This approach led to a proposed distinction of functional P pools in the soil, and identifying the processes of P transformation in the soil between the pools based on a source–sink relationship. Based on these analyses, the organic pool consists of the bicarbonate organic phosphate (Po), hydroxide Po, and sonic Po fractions. The bicarbonate inorganic phosphate (Pi) and hydroxide Pi fractions formed the inorganic pool. The hydrochloride (HCl) Pₕₒₜ and residual P fractions formed the occluded pool, the HCl Pi fraction formed the primary mineral pool, and the resin Pi fraction constituted the most available P pool. Organic P pool was the major source to the available P pool.
In this paper, we study mappings, which approximately preserve angles between inner product spaces. We also introduce a notion of angle in normed spaces. The notion of angle, considered in this part, ...relates to the well-known Birkhoff–James orthogonality. Based on it, we express a characterization for approximate Birkhoff–James orthogonality, introduced in the literature, through this notion of angle. Then we return to the issue of mappings which approximately preserve angle stating some results in normed spaces.
Some anterior chambers do not readily shallow because of insufficient posterior pressure and/or very deep anterior chamber anatomy, which can make unscrolling descemet membrane endothelial ...keratoplasty (DMEK) tissue more challenging with an unmodified tap technique. We present a hands-free method for augmenting posterior pressure by temporarily tucking cellulose sponges under the blades of the eyelid speculum. The sponges transfer some of the eyelid speculum's weight onto the bulbar surface posterior to the iris, thereby indenting the sclera and causing the iris diaphragm to bulge further forward. This hands-free technique can transform a potentially challenging DMEK case into a more straightforward one by facilitating both a shallow anterior chamber and a bimanual unscrolling technique. However, it only works in bicameral eyes with a vitreous body (e.g., an eye with penetrating keratoplasty, vitreous syneresis, and axial myopia) and will not work in unicameral eyes after vitrectomy (e.g., an eye with an Anterior Chamber Intraocular Lens (ACIOL)).
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