Active Symptom-Based Surveillance of Adverse Events Following Immunization Among Individuals Vaccinated with ChAdOx1 nCoV-19 Coronavirus Vaccine in a Tertiary Hospital of Kerala.

Background: The reports on adverse experiences following vaccination are scanty from India. It is important to know the real-world post-vaccination experience outside of clinical trial conditions.

Objectives: The study aims to estimate the incidence of adverse events following immunization with the ChAdOx1 nCoV-19 coronavirus vaccine and to identify the predictors for the development of vaccine adverse events.

Linear canonical transform as a tool to analyze coherence properties of electromagnetic beams propagating in a quadratic phase system.

Linear canonical transformation (LCT) provides a generalized and elegant mathematical framework for analyzing the coherence properties of an electromagnetic (EM) beam propagating in quadratic phase systems (QPSs). It is shown that LCT may be used to analyze coherence properties such as generalized Stokes parameters and EM degree of coherence of a partially coherent EM beam propagating through a QPS. We present simulation results of a Gaussian Schell model beam propagating through a Fourier system, fractional Fourier system, and 4 imaging system with an aperture and beam relay system.

Statistical investigation of the double random phase encoding technique.

The amplitude-encoding case of the double random phase encoding technique is examined by defining a cost function as a metric to compare an attempted decryption against the corresponding original input image. For the case when a cipher-text pair has been obtained and the correct decryption key is unknown, an iterative attack technique can be employed to ascertain the key. During such an attack the noise in the output field for an attempted decryption can be used as a measure of a possible decryption key's correctness.

Compact portable ocular microtremor sensor: design, development and calibration.

Ocular microtremor (OMT) is a physiological high-frequency (up to 150 Hz) low-amplitude (25-2500 nm peak-to-peak) involuntary motion of the human eye. Recent studies suggest a number of clinical applications for OMT that include monitoring the depth of anesthesia of a patient in surgery, prediction of outcome in coma, and diagnosis of brain stem death. Clinical OMT investigations to date have used mechanical piezoelectric probes or piezoelectric strain gauges that have many drawbacks which arise from the fact that the probe is in contact with the eye.

Coherence effects in digital in-line holographic microscopy.

We analyze the effects of partial coherence in the image formation of a digital in-line holographic microscope (DIHM). The impulse response is described as a function of cross-spectral density of the light used in the space-frequency domain. Numerical simulation based on the applied model shows that a reduction in coherence of light leads to broadening of the impulse response.

Role of phase key in the double random phase encoding technique: an error analysis.

We perform a numerical analysis of the double random phase encryption-decryption technique to determine how, in the case of both amplitude and phase encoding, the two decryption keys (the image- and Fourier-plane keys) affect the output gray-scale image when they are in error. We perform perfect encryption and imperfect decryption. We introduce errors into the decrypting keys that correspond to the use of random distributions of incorrect pixel values.

Generalized in-line digital holographic technique based on intensity measurements at two different planes.

In-line digital holography based on two-intensity measurements [Zhang Opt. Lett. 29, 1787 (2004)], is modified by introducing a pi shifting in the reference phase.

Noninterferometric phase retrieval using a fractional Fourier system.

The signal extraction method based on intensity measurements in two close fractional Fourier domains is examined by using the phase space formalism. The fractional order separation has a lower bound and an upper bound that depend on the signal at hand and the noise in the optical system used for measurement. On the basis of a theoretical analysis, it is shown that for a given optical system a judicious choice of fractional order separation requires some a priori knowledge of the signal bandwidth.

Controlling speckle using lenses and free space.

The correlation properties of speckle fields are studied for general paraxial systems. The previous studies on lateral and longitudinal speckle size for the case of free-space propagation (Fresnel transform) are generalized to the case of the linear canonical transform. These results have implications for the control of speckle size, through appropriate design of optical systems, with particular relevance for speckle interferometry.

Key-space analysis of double random phase encryption technique.

We perform a numerical analysis on the double random phase encryption/decryption technique. The key-space of an encryption technique is the set of possible keys that can be used to encode data using that technique. In the case of a strong encryption scheme, many keys must be tried in any brute-force attack on that technique.

Cryptanalysis of optical security systems with significant output images.

The security of the encryption and verification techniques with significant output images is examined by a known-plaintext attack. We introduce an iterative phase-retrieval algorithm based on multiple intensity measurements to heuristically estimate the phase key in the Fourier domain by several plaintext-cyphertext pairs. We obtain correlation output images with very low error by correlating the estimated key with corresponding random phase masks.

Elevated expressions of osteopontin and tenascin C in ascending aortic aneurysms are associated with trileaflet aortic valves as compared with bicuspid aortic valves.

Objective: Ascending aortic aneurysms (AscAAs) are a highly lethal condition whose pathobiology remains to be poorly understood. Although most AscAAs occur in the presence of a trileaflet aortic valve (TAV), a bicuspid aortic valve (BAV) is a common congenital anomaly associated with an increased risk for an AscAA and dissection independent of functional valve pathology but secondary to inherent structural abnormality of the aorta. The objective of this investigation was to compare the patterns of gene expression in aortas between TAV and BAV patients with the aim of identifying markers for AscAAs.

Generalized Yamaguchi correlation factor for coherent quadratic phase speckle metrology systems with an aperture.

In speckle-based metrology systems, a finite range of possible motion or deformation can be measured. When coherent imaging systems with a single limiting aperture are used in speckle metrology, the observed decorrelation effects that ultimately define this range are described by the well-known Yamaguchi correlation factor. We extend this result to all coherent quadratic phase paraxial optical systems with a single aperture and provide experimental results to support our theoretical conclusions.

Paraxial speckle-based metrology systems with an aperture.

Digital speckle photography can be used in the analysis of surface motion in combination with an optical linear canonical transform (LCT). Previously [D. P.

Polarization encoding and multiplexing of two-dimensional signals: application to image encryption.

We discuss an optical system that encodes an input signal to a polarization state, using a spatial light modulator (SLM). Using two SLMs the optical system multiplexes two 2D signals in the polarization domain, and we demonstrate the multiplexing of two binary images. The encryption and decryption of two binary images using an XOR operation is also presented.

Intranasal exposure to staphylococcal enterotoxin B elicits an acute systemic inflammatory response.

Staphylococcus aureus produces a variety of superantigen exotoxins, including staphylococcal enterotoxin B (SEB). Little is known regarding the pathogenesis of SEB entering through the intranasal route. Intranasal exposure to SEB might occur because of nasal packing following surgical procedure, biologic warfare, or even S.

A known-plaintext heuristic attack on the Fourier plane encryption algorithm.

The Fourier plane encryption algorithm is subjected to a known-plaintext attack. The simulated annealing heuristic algorithm is used to estimate the key, using a known plaintext-ciphertext pair, which decrypts the ciphertext with arbitrarily low error. The strength of the algorithm is tested by using this estimated key to decrypt a different ciphertext which was also encrypted using the same original key.

Lensless sensor system using a reference structure.

We describe a reference structure based sensor system for tracking the motion of an object. The reference structure is designed to implement a Hadamard transformation over a range of angular perspectives. We implemented a reference structure with an angular resolution of 5(o) and a field of view of 40(o).