Optical skyrmions formed in terms of polarization are topological quasi-particles, and they have garnered much interest in the optical community owing to their unique inhomogeneous polarization structure and simplicity in their experimental realization. These structures belong to the Poincaré beams satisfying the stable topology. We theoretically investigated the non-diffracting and self-healing Poincaré beams based on the superposition of two orthogonal Bessel modes by the longitudinal mode matching technique.
View Article and Find Full Text PDFOur overarching goal in this paper was to both test and identify applications for a fundamental theorem of replacement-level populations known as the Stationary Population Identity (SPI), a mathematical model that equates the fraction of a population age x and the fraction with x years to live. Since true stationarity is virtually non-existent in human populations as well as in populations of non-human species, we used historical data on the memberships in both chambers of the U.S.
View Article and Find Full Text PDFMulticolor visible high-order Bessel (Bessel-vortex) beams which have a helical wavefront and a long confocal length have garnered significant interest for applications in materials processing and biomedical technologies. In this paper, we demonstrate the direct generation of multicolor (523, 605 and 637 nm) Bessel-vortex beams from a Pr-doped water-proof fluoro-aluminate glass (Pr: WPFG) fiber laser with an intracavity lens which induces chromatic and spherical aberration. The handedness of the generated Bessel-vortex beam is selectively controlled through lateral displacement of the intra-cavity lens.
View Article and Find Full Text PDFWe report the direct generation of vector vortex laser modes at 640 nm from a compact, diode end-pumped continuous-wave : (YLF) laser that utilizes an intracavity lens and diaphragm. On-axis displacement of the intracavity lens, combined with appropriate choice of the intracavity diaphragm, enables selective generation of a desired radial and azimuthal vector laser mode. Such compact, vector vortex laser sources based on : in the visible wavelength region are a significant enabling technology for a wide range of applications.
View Article and Find Full Text PDFFrom Leonhard Euler to Alfred Lotka and in recent years understanding the stationary process of the human population has been of central interest to scientists. Population reproductive measure NRR (net reproductive rate) has been widely associated with measuring the status of population stationarity and it is also included as one of the measures in the millennium development goals. This article argues how the partition theorem-based approach provides more up-to-date and timely measures to find the status of the population stationarity of a country better than the NRR-based approach.
View Article and Find Full Text PDFVisible vortex beams have a large array of applications; however, the sources are often large or complex. Here, we present a compact vortex source with red, orange, and dual wavelength emission. This Pr:Waterproof Fluoro-Aluminate Glass fiber laser uses a standard microscope slide as an interferometric output coupler, yielding high quality first order vortex modes in a compact setup.
View Article and Find Full Text PDFObjective: To determine whether initiating saline nasal irrigation after COVID-19 diagnosis reduces hospitalization and death in high-risk outpatients compared with observational controls, and if irrigant composition impacts severity.
Methods: Participants 55 and older were enrolled within 24 hours of a + PCR COVID-19 test between September 24 and December 21, 2020. Among 826 screened, 79 participants were enrolled and randomly assigned to add 2.
Two-photon microscopy (TPM) offers deeper imaging depth inside the scattering medium, however, it suffers from limited resolution owing to the longer excitation wavelength. We demonstrate the use of a hollow Gaussian beam (HGB) at the therapeutic window to improve the resolution and signal-to-background ratio (SBR). The HGB was produced by omitting the azimuthal phase term from the vortex mode, and the excitation point spread function (PSF) can be readily tuned by the mode order.
View Article and Find Full Text PDFWe demonstrate an ultra-compact (8 mm-long) green orbital Poincaré Pr:LiYF (YLF) laser, in which the intracavity lasing modes are represented as eigenmodes on an equivalent orbital Poincaré sphere (eOPS). This is achieved through the simple application of an 'optical-needle' pumping geometry in conjunction with off-axis laser mode-manipulation. Optical vortices that are produced and mapped on north and south poles of the eOPS exhibit a maximum output power of 304 mW with a pump-to-laser-output slope efficiency of 12%.
View Article and Find Full Text PDFJ Math Anal Appl
October 2022
We consider the structure of the novel coronavirus (SARS-Cov-2) in terms of the number of spikes that are critical in bonding with the cells in the host. Bonding formation is considered for selection criteria with and without any treatments. Functional mappings from the discrete space of spikes and cells and their analysis are performed.
View Article and Find Full Text PDFBackground: The increasing shortage of specialized health care services contributes to the ongoing HIV epidemic. Telemedicine (TM) is a potential tool to improve HIV care, but little is known about its effectiveness when compared with traditional (face-to-face [F2F]) care in rural populations. The objective of this study was to compare the effectiveness of HIV care delivered through TM with the F2F model.
View Article and Find Full Text PDFComputation of basic reproductive numbers is one of the primary goals of epidemic modelers. There are several challenges in such computations, especially when the data from the virus transmission networks are not so easy to collect; this makes model validation almost impossible. We provide a technical comment on the precautions to be taken while computing model-based basic reproductive numbers so that the ground realities of such computation are maintained.
View Article and Find Full Text PDFHere we demonstrate intracavity frequency-doubling of an ultra-compact (cavity length < 20 mm) Pr:LiYF (YLF) orbital Poincaré laser, in which the fundamental modes are represented on an equivalent orbital Poincaré sphere (eOPS) and a singularities hybrid evolution nature sphere (SHENS). The generated ultraviolet (UV, 320 nm) output carries orbital angular momentum (OAM), and it typically exhibits an optical bottle beam with a 3-dimensional dark core, formed of a coherent superposition of eigen Laguerre-Gaussian (LG) modes. Such ultraviolet structured light beams with OAM offer many advanced applications from microscopy to materials processing.
View Article and Find Full Text PDFBackground: Length of stay (LOS) is an important measure of quality; however, estimating LOS for rare populations such as gastroschisis is problematic. Our objective was to identify explanatory variables for LOS and build a model to estimate LOS in neonates with simple gastroschisis.
Methods: In 73 neonates with simple gastroschisis (47% female, 67% White), statistical correlations for 31 potential explanatory variables for LOS were evaluated using multivariate linear regression.
We highlight the advantages of virtual tourism and the use of data science to improve existing television and internet-based experiences with new technologies. Information geometry and conformal mappings can improve audiovisual experiences based on drone recordings. The data collection, assimilation, and transformation requirements for a seamless and user-friendly service are discussed along with the precautions to ensure that this technology is used appropriately to protect human safety and the environment.
View Article and Find Full Text PDFWe propose the use of a machine learning algorithm to improve possible COVID-19 case identification more quickly using a mobile phone-based web survey. This method could reduce the spread of the virus in susceptible populations under quarantine.
View Article and Find Full Text PDFIn this technical article, we are proposing ideas, that we have been developing on how machine learning and deep learning techniques can potentially assist obstetricians/gynecologists in better clinical decision-making, using infertile women in their treatment options in combination with mathematical modeling in pregnant women as examples.
View Article and Find Full Text PDFA new synthetic route for the total synthesis of dendrodolide-L has been developed from known chiral epoxides. The key reactions involved in this synthesis are regioselective ring-opening of epoxide, Yamaguchi esterification and ring-closing metathesis reactions (RCM) to result the target compound.
View Article and Find Full Text PDFCoccidiosis is one of the biggest challenges faced by the global poultry industry. Recent studies have highlighted the ubiquitous distribution of all Eimeria species which can cause this disease in chickens, but intriguingly revealed a regional divide in genetic diversity and population structure for at least one species, Eimeria tenella. The drivers associated with such distinct geographic variation are unclear, but may impact on the occurrence and extent of resistance to anticoccidial drugs and future subunit vaccines.
View Article and Find Full Text PDFThe phylum Apicomplexa includes parasites of medical, zoonotic and veterinary significance. Understanding the global distribution and genetic diversity of these protozoa is of fundamental importance for efficient, robust and long-lasting methods of control. Eimeria spp.
View Article and Find Full Text PDFIn this present research work, the aim was to develop ileo-colonic targeted matrix-mini-tablets-filled capsule system of Naproxen for chronotherapeutic treatment of Rheumatoid Arthritis. So Matrix-mini-tablets of Naproxen were prepared using microsomal enzyme dependent and pH-sensitive polymers by direct compression method which were further filled into an empty HPMC capsule. The compatibility was assessed using FT-IR and DSC studies for pure drug, polymers and their physical mixtures.
View Article and Find Full Text PDFThis research work aims to determine the pharmacokinetic parameters and in vitro-in vivo correlation of the selected ileocolonic-targeted coated mini-tablet filled capsule formulation of naproxen. The pure suspension and coated mini-tablet filled capsule formulation of naproxen were administered to adult albino rabbits through the oral route. The samples were analyzed for naproxen by an HPLC method.
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