Our objective is to quantify the spectral changes occurring in partially coherent light beams as they interact with the crystalline lens of the human eye. The study reveals a significant alteration in the wavelength of random light beams as they traverse through the human eye. The methodology comprises three key components: the ABCD matrix elements of the lens, the cross-spectral density matrix of the light beam, and the spectral shifts in the beam during propagation. Following an initial examination of how the crystalline human eye lens responds to stochastic light, we can now analyze the interaction of various types of light with the eye lens. The entering light is broadband, exhibiting a range of coherence values from incoherent to fully coherent. By employing the diffraction theory of optics alongside ray tracing methods, we observe wavelength shifts in partially coherent light passing through the human eye lens. The study involves directing unpolarized random light with a cross-sectional radius of approximately 0.3 mm numerically to the lens surface, situated at the minimum pupil radius of around 0.5 mm. The propagation is then analyzed over a distance of 17 mm after the lens, representing the typical length of the vitreous humor. Numerical plots demonstrate a wavelength shift in the incident light (with a Gaussian profile). In summary, our findings indicate that the correlation effects of nearly natural light on the gradient index of the human eye lens lead to a notable spectral shift.

Correlations between stochastic electromagnetic beams' intensity variations which are produced by sources with anisotropic crossspectral density matrices are explored. Recently introduced spectral degree of cross -polarization, spectral degree of coherence, and the intensity fluctuations of electromagnetic sources are analyzed upon propagation by considering the source as an anisotropic beam. An analytical formula is given for the cross -spectral density matrix of an anisotropic electromagnetic Gaussian Schell beam moving across free space and extended to longitudinal and transverse directions. The analysis shows that the cross -polarization of two beams having same source parameters might increase or decrease on propagation depending on the anisotropy ratio alpha. Numerical results are presented to show that the beam anisotropy might be one of the convenient methods for modeling partially coherent sources.

Phase-space transforms describe spatial and angular information about light sources where one example is the Wigner functions in wave optics. Stokes parameters, on the other hand, supply information about the polarization of light beams. The generalized phase space Stokes parameters of 2D stochastic electromagnetic beams are already developed. In this article, the application of anisotropic light sources in generalized phase space Stokes parameters is theoretically investigated and numerically analyzed. There are several different ways of studying electromagnetic light beams depending on the spatial domain. But, most measure of the polarization of random light fields is carried out within the Stokes parameters context. In this account we study the electromagnetism, Stokes parameters, phase space, and the anisotropy properties of random light beams at once. We find here that when an anisotropy introduced in phase space then the cross terms of the Wigner matrix depart from the diagonal terms, which is not the same in configuration space. As a result, anisotropy has a different effect in Phase space, i.e. an anisotropic source introduces a phase and a variance change only in the cross terms of Wigner matrix. This is due to the use of anisotropy in the shifted kernel of Wigner transform.

A class of electromagnetic random sources with a multi-Gaussian functional form in the spectral density and in the correlations part of the cross-spectral density matrix is introduced based on the genuine cross-spectral density-matrix theory. The analytic propagation formulas of the cross-spectral density matrix of such beams propagating in free space are derived by use of Collins' diffraction integral. With the help of analytic formulas, the evolution of statistical characteristics, i.e., the spectral density, the spectral degree of polarization, and the spectral degree of coherence for such beams in free space are analyzed numerically. Employing the multi-Gaussian functional form in the cross-spectral density matrix introduces one more freedom in the modeling of Gaussian Schell-model sources.

In this study, we characterized a collection of clinical samples obtained from Syrian and Turkish patients with cutaneous leishmaniasis using internal transcribed spacer 1 (ITS1) sequences. All obtained sequences belonged to Leishmania tropica. Combining them with those available from GenBank allowed us performing a broad-scale analysis of genetic diversity for this species. We demonstrated that L. tropica has a complex phylogeographic pattern with some haplotypes being widespread across endemic countries and others restricted to particular regions. We hypothesize that at least some of them may be associated with alternative vectors or animal reservoirs.

Amaç Dünya Sağlık Örgütü Akılcı İlaç Kullanımı’nı, “hastaların klinik ihtiyaçlarına uygun ilaçları, kişisel gereksinimlerini karşılayan dozlarda, yeterli bir süre boyunca, kendilerine ve topluma en az maliyet ile kullanmaları” olarak tanımlamıştır. akılcı ilaç kullanımında hastanın, hekimin ve eczacının verdiği talimatlar doğrultusunda ilacını kullanması gerekmektedir. Bu çalışmada Yozgat Bozok Üniversitesi Tıp Fakültesi öğrencilerinin akılcı ilaç kullanımına ilişkin düşüncelerinin değerlendirilmesi amaçlanmıştır. Bulgular Öğrencilerin yaş ortalaması 20,2 ± 1,2, % 47,3’ü erkekti. Öğrencilerin yaklaşık üçte ikisi akılcı ilaç kullanımını hastaya uygun ilaç yazılması olarak tanımladı, öğrencilerin yaklaşık yarısıda akılcı ilaç kullanımı eğitimi aldıklarını ifade etti. Hekimlerce en sık ağrı kesici ilaçların yazıldığını, akılcı ilaç kullanımına en büyük engelin yanlış tanı ve yoğunluktan hasta ile yeterince ilgilenememe olduğu belirtildi. Öğrenciler, Akılcı ilaç kullanımında en önemli paydaşın hekimler olduğunu ve ayrıca aktarlar, televizyon, internet vb. yollarla bitkisel ürünlerin alınarak kullanılmasının, hastaya uygulanacak tedavi sürecinin başarısında olumsuz etkisinin olduğunu ifade etti. Sonuç Akılcı ilaç kullanımına engel olarak görülen hasta muayene süreleri için sağlık yöneticileri tarafından hekimlerin hastası için ayırdığı muayene süresini yeterli düzeye getirecek tedbirlerin (hekim başına düşen hasta sayısı gibi) alınmasının da, akılcı ilaç kullanımı konusunda ilerleme ve katkı sağlayacağını düşündürmektedir.

We derive analytical expressions for the cross-spectral density matrix of polychromatic electromagnetic multi-Gaussian Schell-model (EMGSM) beam transmission through a gradient-index fiber. The space-spectrum evolution properties for the spectral density, spectral shift, degree of polarization, and electromagnetic coherence state of a polychromatic EMGSM beam with Lorentzian line type spectrum and central wavelength λ0=1550  nm propagation in a silica-clad germania core inhomogeneous graded-index fiber are studied in detail. We show that these statistical properties exhibit periodicity in the fiber, caused by the focusing property of square-law media, which can be reminiscent of the self-imaging effect of optical fields. The effects of the nonconventional correlation functions of the polychromatic EMGSM beam on the transmission properties are also investigated.

OBJECTIVE:The present study aimed to evaluate scabies and pediculosis cases in the city of Kayseri and to contribute to the epidemiological data in Turkey.METHODS:Data for the present study were obtained from the Kayseri Directorate of Public Health. The distribution of lice and scabies according to age, sex, and years was evaluated retrospectively.RESULTS:A total of 3908 scabies and 4762 pediculosis cases have been reported from the central and peripheral districts of Kayseri between January 2006 and April 2017. It was observed that the number of female cases is higher in both infestations. When positive cases were evaluated according to age, it appears that scabies cases in the 25-44 age group and pediculosis cases in the 10-14 age group are higher. At the same time, in the first 4 months of 2017, it was observed that the number of cases in both infestations was two times higher than that in the previous year.CONCLUSION:We believe that scabies and pediculosis infestations are still a major public health concern in Turkey and its city.

We introduce analytical models for scattering potentials of particles that have ellipsoid-, cylinder-, and parallelepiped-like shapes and adjustable edge sharpness with the help of the three-dimensional versions of the multi-Gaussian functions. The far fields produced upon scattering from such potentials are examined in detail and are shown to qualitatively and quantitatively depend on the scatterer's symmetry type as well as its orientation and edge sharpness.

Planar, scalar, optical Schell-model, and quasi-homogeneous sources with correlations that are Fourier transforms of multi-Gaussian functions are introduced. It is demonstrated that far fields produced by these families of sources carry interesting characteristics, being flatlike with adjustable steepness of the edge. Beam conditions for such sources are also derived.

In a recent publication [Opt. Lett.37, 2970 (2012)10.1364/OL.37.002970], a novel class of planar stochastic sources, generating far fields with flat intensity profiles, was introduced. In this paper we examine the behavior of the spectral density and the state of coherence of beamlike fields generated by such sources on propagation in free space and linear isotropic random media. In particular, we find that at sufficiently large distances from the source, the medium destroys the flat intensity profile, even if it remains such for intermediate distances from the source.

A three-dimensional multi-Gaussian function is adopted for modeling of a spherically-symmetric scatterer with semi-soft boundary, i.e. such that has continuous and adjustable drop in the index of refraction.

A three-dimensional multi-Gaussian function, being a finite sum of Gaussian functions, is adopted for modeling of a spherically symmetric scatterer with a semisoft boundary, i.e. such that has continuous and adjustable drop in the index of refraction. A Gaussian sphere and a hard sphere are the two limiting cases when the number of terms in multi-Gaussian distribution is one and infinity, respectively. The effect of the boundary's softness on the intensity distribution of the scattered wave is revealed. The generalization of the model to random scatterers with semisoft boundaries is also outlined.

We present the first account (to our knowledge) of interaction between stochastic light and the crystalline human eye lens. In particular, the spectral density and the spectral degree of polarization of light focused by the crystalline lens onto the eye’s back wall are examined. We find that the correlation properties of the incident light play the important role in the process of image formation by the eye and in its perception of polarization features of the incoming radiation.

An active bistatic LIDAR system operating through atmospheric turbulence is considered. Illumination field is assumed to be an electromagnetic Gaussian–Schell model beam. Target surface is modeled as a combination of isotropic phase screen governed by Gaussian statistics, to account for its roughness, and a Gaussian lens to account for its size and radius of curvature. With the help of a recently developed tensor method for propagation of stochastic electromagnetic beams through ABCD systems and random media we examine the evolution of states of coherence and polarization of the beam. In the case of unresolved flat (planar) target we show that by comparing coherence and polarization properties of the illumination beam and of the return beam it is possible to predict the typical roughness of the target surface.

The generalized Stokes parameters (GSP) are studied under the theory of phase space. It is noted that phase-space Stokes parameters can be a useful tool for Wigner distribution function measurements. Electromagnetic Wigner functions are introduced by use of the two-point statistics of GSP. The advantage in the GSP is that they can be measured in terms of the electric correlation matrix (which is a measurable quantity) or they can be measured independently. Hence, the GSP help in finding the polarization and coherence properties of electromagnetic beams. Within this framework, by using the GSP in phase space, the intensity feature of electromagnetic beams in phase space is given, as well.

Based on the unified theory of coherence and polarization and the extended Huygens–Fresnel integral the free-space evolution of the recently introduced spectral degree of cross-polarization of a stochastic electromagnetic beam is studied. Unlike the spectral degree of coherence, the degree of cross-polarization is unbounded and exhibits non-monotonic changes with growing propagation distance and growing radial distance from the center of the beam, at fixed transverse cross-sections. Our numerical results pertain to the electromagnetic Gaussian Schell-model beams. We derive expressions for the cross-spectral density matrix of the EGSM beam for arbitrary transverse and longitudinal positions. The results show that the behavior of the degree of cross-polarization on propagation is determined by all of the parameters of the source radiating the beam. At sufficiently large distances from the source, the degree of cross-polarization stabilizes for all points within the beam independently of their radial positions.

Using scattering matrices and the angular spectrum representation of waves, we develop the analytical theory of scattering of random scalar waves from random collections of particles, valid under the first Born approximation. We demonstrate that in the calculation of far-field statistics, such as the spectral density and the spectral degree of coherence, the knowledge of the pair-structure factor of the collection is crucial. We illustrate our analytical approach by considering a numerical example involving scattering of two partially correlated plane waves from a random distribution of spheres.

Fluctuations in Stokes parameters of stochastic electromagnetic beams on propagation in turbulent atmosphere are studied. The expressions are derived for the scintillation indexes (contrasts) of the Stokes parameters and their versions normalized by the instantaneous intensity in the case when the beam is generated by the electromagnetic Gaussian Schell-model source with uniform polarization. We illustrate our analytical results by numerical examples.