Propagation through and characterization of atmospheric and oceanic phenomena: introduction to the joint feature issue in Applied Optics and Journal of the Optical Society of America A.

This joint feature issue in Applied Optics and JOSA A collects articles focused on the topic of propagation through and characterization of atmospheric oceanic phenomena. The papers cover a broad range of topics, many of which were addressed at the 2023 Propagation Through and Characterization of Atmospheric Oceanic Phenomena (pcAOP) Topical Meeting at the Optica Imaging Congress in Boston, Massachusetts, 14-17 August 2023. These papers are supplemented by numerous examples of the current state of research in the field.

Propagation through and characterization of atmospheric and oceanic phenomena: introduction to the joint feature issue in Applied Optics and Journal of the Optical Society of America A.

This joint feature issue in Applied Optics and JOSA A collects articles focused on the topic of propagation through and characterization of atmospheric oceanic phenomena. The papers cover a broad range of topics, many of which were addressed at the 2023 Propagation Through and Characterization of Atmospheric Oceanic Phenomena (pcAOP) Topical Meeting at the Optica Imaging Congress in Boston, Massachusetts, 14-17 August 2023. These papers are supplemented by numerous examples of the current state of research in the field.

Field correlations of multimode optical beams in underwater turbulence.

For multimode optical beams, field correlations at the receiver plane are found in underwater turbulence. Field correlations of single high order beams in underwater turbulence are special cases of our formulation. Variations of field correlations against the underwater turbulence parameters and the diagonal length from various receiver points are examined for different multimode and single high order beams.

Monte-Carlo based vertical underwater optical communication performance analysis with chlorophyll depth profiles.

Although underwater wireless optical communication (UWOC) has the advantages of high speed, low latency, and high confidentiality, the transmission of light in water will be affected by the absorption and scattering of particles, which will lead to the aggravation of channel path loss as well as channel pulse spreading, finally causing false codes. Therefore, how to analyze the channel impulse response (CIR) effectively is a key task in channel modeling. In this paper, we consider a two-way underwater vertical line-of-sight (LOS) communication system model, based on the inherent optical property (IOP) model of chlorophyll, using the Kopelevich phase function containing water depth information, the CIR curves under different water types and transceiver configurations are plotted using the Monte-Carlo Simulation (MCS).

Correlations of multimode optical incidences in a turbulent biological tissue.

In a turbulent biological tissue, field correlations at the observation plane are found when a multimode optical incidence is used. For different multimode structures, variations of the multimode field correlations are evaluated against the biological tissue turbulence parameters, i.e.

Aperture-averaged scintillation for a weak underwater turbulence-affected Gaussian beam using the OTOPS model.

The calculation of optical system performance for laser beam propagation in optical turbulence, such as bit error rate (BER), signal-to-noise ratio, and probability of fade, requires the knowledge of scintillation. In this paper, we show the analytical expressions of the aperture-averaged scintillation using a new recently introduced power spectrum of the refractive index fluctuations for underwater turbulence, the oceanic turbulence optical power spectrum (OTOPS). In addition, we use this main result to investigate the impact of weak oceanic turbulence on free-space optical system performance for a propagating Gaussian beam wave.

Correlation of multimode fields in atmospheric turbulence.

Multimode field correlations are evaluated in atmospheric turbulence. High order field correlations are special cases of the results that we obtained in this paper. Field correlations are presented for various numbers of multimodes, various multimode contents of the same number of modes, and various high order modes versus the diagonal distance from various receiver points, source size, link length, structure constant, and the wavelength.

Prevention of Scarring of Lung Parenchyma in COVID-19 Patients through Glucocorticoid Treatment.

The objective of this research was to determine the impact of glucocorticoid treatment on preventing scarring of lung parenchyma in COVID-19 patients by considering their health behavior. A sample of 65 Turkish patients who had pneumonia and were hospitalized between March/December 2020 were included in this research. The data for this research was collected after the consent of the hospital.

Structure functions for optical waves in a complex medium of turbulent biological tissues.

Although optical wave propagation is investigated based on the absorption and scattering in biological tissues, the turbulence effect can also not be overlooked. Here, the closed-form expressions of the wave structure function (WSF) and phase structure function (PSF) of plane and spherical waves propagating in biological tissue are obtained to help with future research on imaging, intensity, and coherency in turbulent biological tissues. This paper presents the effect of turbulent biological tissue on optical wave propagation to give a perception of the performance of biomedical systems that use optical technologies.

Absorption, scattering, and optical turbulence in natural waters.

The Beer-Lambert-Bouguer law characterizes attenuation of an optical plane wave resolved in terms of absorption and scattering of a medium it passes through. However, the optical turbulence present in a medium may also cause severe local attenuation in beam-like light fields. This study aims to incorporate the effects of absorption and scattering with that of optical turbulence in Earth's natural waters.

Temporal statistics of irradiance fluctuations in an underwater turbulent medium.

Expressions for the temporal covariance function and temporal frequency spectrum for a plane wave propagation in an underwater turbulent medium are developed analytically. Temporal correlation in moving natural water is presented, which is shown to be dependent upon the moving velocity, the delay between two instants of time, propagation distance, average temperature, and average salinity concentration. Coherence time and zero crossing time also are calculated.

Use of colistin with rifampicin, trimethoprim-sulfamethoxazole and teicoplanin in mouse infection model.

Infections with multidrug-resistant Gram-negative bacteria such as are major cause of morbidity and mortality. Colistin is used commonly to treat these infections. In this study, we evaluated the efficacy of different colistin combinations in a infection mouse model.

Structure function, coherence length, and angle-of-arrival variance for Gaussian beam propagation in turbulent waters.

Wave structure function, coherence length, and angle-of-arrival variance are derived analytically for a Gaussian beam propagating in an underwater turbulent medium. The recently introduced oceanic turbulence optical power spectrum model [J. Opt.

Electromagnetic phase coherence gratings for atmospheric applications.

We propose using electromagnetic phase coherence gratings (EMPCGs) for fine spatial segregation in polarimetric components of stationary beams on their propagation in atmospheric turbulence. Unlike for other beams, e.g.

Underwater imaging in optical turbulence: average temperature and salinity effects.

Classic imaging systems may experience deleterious effects of optical turbulence, leading to their quality degradation induced by image jitter and blur. Using a recently introduced model for the refractive index power spectrum of natural water turbulence accounting for average temperature in the range of 0°-30°C and average salinity concentration in NaCl in the range of 0-40 ppt, we derive expressions for turbulence-induced modulation transfer functions. Our analysis indicates that the imaging systems are very sensitive not only to the variance of fluctuations in these parameters but also to their average values.

International Nosocomial Infection Control Consortium (INICC) report, data summary of 45 countries for 2013-2018, Adult and Pediatric Units, Device-associated Module.

Background: We report the results of INICC surveillance study from 2013 to 2018, in 664 intensive care units (ICUs) in 133 cities, of 45 countries, from Latin-America, Europe, Africa, Eastern-Mediterranean, Southeast-Asia, and Western-Pacific.

Methods: Prospective data from patients hospitalized in ICUs were collected through INICC Surveillance Online System. CDC-NHSN definitions for device-associated healthcare-associated infection (DA-HAI) were applied.

Adaptive optics correction in natural turbulent waters.

The recently introduced power spectrum of the refractive index fluctuations of the natural oceanic water turbulence is applied to an underwater communication system in the presence of adaptive optics corrections. The effects of the average temperature (0-30°C), the average salinity (0-40 ppt), the temperature-salinity gradient ratio (0-400°C/ppt), and the wavelength of the source (400-700 nm) on such a system are considered for the first time, to the best of our knowledge. It is revealed that even in the presence of adaptive optics the communication system's operation is severely affected by the regional and seasonal averages and fluctuations in the water's refractive index.

Performance of M-ary pulse position modulated optical wireless communications systems in the marine atmosphere.

The marine atmosphere exhibits different turbulence spectrum characteristics when compared to the turbulence spectra of the land atmosphere and underwater medium. The performance of M-ary pulse position modulated (PPM) optical wireless communications (OWC) systems operating in the marine atmosphere, as measured by the bit error rate (BER), is studied here. In our investigation, the scintillation index and the average intensity in marine atmospheric turbulence are used.

Future perspective: biologic agents in patients with severe COVID-19.

The SARS-CoV-2 is a β-CoV, which is enveloped by non-segmented positive-stranded RNA virüs. When β-CoV infects the respiratory tract, it can cause mild and/or severe acute respiratory syndrome (SARS) with consequent release of cytokines/mediators, including interleukin (IL)-1β, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8 (CXCL8), IL-10, IP10, IL-12, IL-13, IL-17, IL-33, IL-25, IL-37, IL-38, GCSF, GM-CSF, HGF, IP-10, MCP-1, MIP-1α (also known as CCL3), IFN-γ, IFN-α, TRAIL, MCSF, and TNF-α. Our hypothesis of writing this article can be summarized as; if the monoclonal antibody (mAb) administered by us does not inhibit the immune response for the β-CoV and inhibits uncontrolled-adaptive/hyperimmune responses (also called cytokine storm) on endothelium level, then it may cause severe coronavirus disease 2019 (COVID-19).

A case of asthma with Behcet's disease: successful treatment with omalizumab and its effects on recurrent aphthous lesions.

Context: Monoclonal antibody therapies have revolutionized the treatment of autoinflammatory-immune/genetic disease including spondylarthritis, asthma and rheumatoid arthritis. Behcet's disease (BD) is a multi-systemic vasculitis, which is generally recurrent aphthous lesions (RAL) as well as ocular and skin lesions. Today, the immunohistopathogenesis of BD is mostly unknown.

Performance of M-ary pulse position modulation for aeronautical uplink communications in an atmospheric turbulent medium.

This paper discusses the bit-error-rate (BER) performance of an aeronautical uplink optical wireless communication system (OWCS) when a Gaussian beam is employed and the M-ary pulse position modulation technique is used in an atmospheric turbulent medium. Weak turbulence conditions and log-normal distribution are utilized. The Gaussian beam is assumed to propagate on a slant path, the transmitter being ground-based, and the airborne receiver is on-axis positioned.

On channel capacity of FSO communication systems in anisotropic non-Kolmogorov strong turbulent atmosphere.

Average channel capacity of free space optical (FSO) communication systems using a Gaussian beam with the intensity modulation and direct detection technique is investigated in anisotropic non-Kolmogorov strong turbulent atmosphere. The channel model is selected as gamma-gamma distribution, which is valid for strong turbulence. Obtained results show that anisotropy in both the horizontal and vertical affects the average channel capacity of an FSO communication system positively.

Effect of strong atmospheric non-Kolmogorov turbulence on the M-ary PSK subcarrier intensity modulated free space optical communications system performance.

Atmospheric turbulence is one of the significant phenomena that degrades the free space optical (FSO) communications system performance, and thus designers need to define the requirements related to turbulence and optimize the system design to ensure optimum performance. The subcarrier intensity modulation (SIM) shows superiority in terms of bandwidth usage over the other modulation techniques. Performance of FSO communication systems exercising M-ary phase-shift-keying (PSK) SIM with the PIN photodiode receiver is evaluated in non-Kolmogorov strong atmospheric turbulence when a Gaussian beam is used as the excitation.