Grading of Anatomopathological Disparity in the Cases of Invasive Pulmonary Aspergillosis in wild avian species as recorded in Pigeons (Columba livia), Peafowls (Pavo cristatus), and Griffon Vultures (Gyps fulvus).

Aspergillosis which is caused by Aspergillus fumigatus, a fungal pathogen, can vary from a localized infection to severe life-threatening invasive or disseminated systemic diseases in birds. The present study aimed to evaluate and grade the anatomopathological disparity in the cases of invasive pulmonary aspergillosis (IPA) in Columba livia (pigeons), Pavo cristatus (peafowls), and Gyps fulvus (Griffon vultures). Necropsy gross lesions varied from mere congestion of lungs in P. cristatus, congestion and large necrotizing masses surrounded by a zone of hyperemia (10 mm dia) in lungs of C. livia, and typically disseminated granuloma in the lungs, air sacs, and organs of other serous membranes in G. fulvus. Histopathology varied from extensive parenchymal necrosis amidst exuberant fungal invasion in P. cristatus, multifocal to focally extensive tissue necrosis with colonies of fungal hyphae surrounded by heterophils and lymphocytes in C. livia, as well as typical mycotic granuloma embedded in the lungs, air sacs, and thoracoabdominal serous membranes with angio-invasion in G. fulvus. Based on gross and histopathological findings, we diagnosed the cases as Acute Invasive Pulmonary Aspergillosis (AIPA) in peafowls and pigeons, as well as Chronic Invasive Pulmonary Aspergillosis (CIPA) in Griffon vultures. There is a paucity of case reports on aspergillosis in wild avian species, and this report strived to document the cases of IPA in peafowls, pigeons, and vultures. This is the first report of its kind which evaluated anatomopathological disparity of IPA in pigeons, peafowls, and vultures with a proposed anatomopathological grading system which would help to understand and investigate the nature of aspergillosis in different avian hosts.

Mechanistic details of energy transfer and soft landing in ala2-H(+) collisions with a F-SAM surface.

Previous chemical dynamics simulations (Phys. Chem. Chem. Phys., 2014, 16, 23769-23778) were analyzed to delineate atomistic details for collision of N-protonated dialanine (ala2-H(+)) with a C8 perfluorinated self-assembled monolayer (F-SAM) surface. Initial collision energies Ei of 5-70 eV and incident angles θi of 0° and 45°, with the surface normal, were considered. Four trajectory types were identified: (1) direct scattering; (2) temporary sticking/physisorption on top of the surface; (3) temporary penetration of the surface with additional physisorption on the surface; and (4) trapping on/in the surface, by physisorption or surface penetration, when the trajectory is terminated. Direct scattering increases from 12 to 100% as Ei is increased from 5 to 70 eV. For the direct scattering at 70 eV, at least one ala2-H(+) heavy atom penetrated the surface for all of the trajectories. For ∼33% of the trajectories all eleven of the ala2-H(+) heavy atoms penetrated the F-SAM at the time of deepest penetration. The importance of trapping decreased with increase in Ei, decreasing from 84 to 0% with Ei increase from 5 to 70 eV at θi = 0°. Somewhat surprisingly, the collisional energy transfers to the F-SAM surface and ala2-H(+) are overall insensitive to the trajectory type. The energy transfer to ala2-H(+) is primarily to vibration, with the transfer to rotation ∼10% or less. Adsorption and then trapping of ala2-H(+) is primarily a multi-step process, and the following five trapping mechanisms were identified: (i) physisorption-penetration-physisorption (phys-pen-phys); (ii) penetration-physisorption-penetration (pen-phys-pen); (iii) penetration-physisorption (pen-phys); (iv) physisorption-penetration (phys-pen); and (v) only physisorption (phys). For Ei = 5 eV, the pen-phys-pen, pen-phys, phys-pen, and phys trapping mechanisms have similar probabilities. For 13.5 eV, the phys-pen mechanism, important at 5 eV, is unimportant. The radius of gyration of ala2-H(+) was calculated once it is trapped on/in the F-SAM surface and trapping decreases the ion's compactness, in part by breaking hydrogen bonds. The ala2-H(+) + F-SAM simulations are compared with the penetration and trapping dynamics found in previous simulations of projectile + organic surface collisions.