Existence and features of the myodural bridge in Gentoo penguins: A morphological study

Recent studies have evidenced that the anatomical structure now known as the myodural bridge (MDB) connects the suboccipital musculature to the cervical spinal dura mater (SDM). In humans, the MDB passes through both the posterior atlanto-occipital and the posterior atlanto-axial interspaces. The existence of the MDB in various mammals, including flying birds (Rock pigeons and Gallus domesticus) has been previously validated. Gentoo penguins are marine birds, able to make 450 dives per day, reaching depths of up to 660 feet. While foraging, this penguin is able to reach speeds of up to 22 miles per hour. Gentoo penguins are also the world’s fastest diving birds. The present study was therefore carried out to investigate the existence and characteristics of the MDB in Gentoo penguin (Pygoscelis papua), a non-flying, marine bird that can dive. For this study, six Gentoo penguin specimens were dissected to observe the existence and composition of their MDB. Histological staining was also performed to analyze the anatomic relationships and characteristic of the MDB in the Gentoo penguin. In this study, it was found that the suboccipital musculature in the Gentoo penguin consists of the rectus capitis dorsalis minor (RCDmi) muscle and rectus capitis dorsalis major (RCDma) muscle. Dense connective tissue fibers were observed connecting these two suboccipital muscles to the spinal dura mater (SDM). This dense connective tissue bridge consists of primarily type I collagen fibers. Thus, this penguin’s MDB appears to be analogous to the MDB previously observed in humans. The present study evidences that the MDB not only exists in penguins but it also has unique features that distinguishes it from that of flying birds. Thus, this study advances the understanding of the morphological characteristics of the MDB in flightless, marine birds.

Panophthalmitis in a Gentoo Penguin (Pygoscelis Papua) From The Antarctic Peninsula: Evaluation of Microbiological and Histopathological Analysis Outcomes

In this study, it was aimed to present the results of microbiological, cytological, histopathological, and immunohistochemical analyses of ocular samples from an Antarctic (Ardley Island, King George Island) Gentoo penguin chick (Pygoscelis papua) with pyogranulomatous panophthalmitis in the right eye. Samples were taken from both the healthy left eye and the lesion in the right eye. Conventional culture methods and phenotypic and molecular tests were used for bacterial isolation and identification, respectively. None of the isolates could be identified phenotypically. As a result, four of the five isolates obtained from the right eye were considered to belong to putative novel bacterial species and taxa as their similarity to GenBank data was below 98.75%. The isolates were considered to be Pasteurellaceae bacterium, Corynebacterium ciconiae, Cardiobacteriaceae bacterium, Actinomyces sp., and Dermabacteraceae bacterium. The only isolate from the left eye was identified as Psychrobacter pygoscelis. The cytological analysis demonstrated cell infiltrates composed mostly of degenerate heterophils, reactive macrophages, plasma cells, lymphocytes, and eosinophils. Based on histopathological findings, the lesion was defined as typical pyogranulomatous panophthalmitis. Immunohistochemistry demonstrated that the granuloma was positive for TNF-α, IL-4, MMP-9, IL-1β, and IL-6. This is the first documented report of unilateral pyogranulomatous panophthalmitis in a Gentoo penguin chick, living in its natural habitat in Antarctica. This report also describes the isolation of four bacteria from the infected eye, which are considered to belong to novel Genus, species, or taxa. The primary bacterial pathogen that caused the ocular lesion was not able to be detected and remains unclear.

Coastal regions of the northern Antarctic Peninsula are key for gentoo populations

Southern Ocean ecosystems are rapidly changing due to climate variability. An apparent beneficiary of such change in the western Antarctic Peninsula (WAP) is the gentoo penguin Pygoscelis papua , which has increased its population size and expanded its range southward in the last 20 years. To better understand how this species has responded to large-scale changes, we tracked individuals during the non-breeding winter period from five colonies across the latitudinal range of breeding sites in the WAP, including from a recently established colony. Results highlight latitudinal gradients in movement; strong associations with shallow, coastal habitats along the entire Antarctic Peninsula; and movements that are independent of, yet constrained by, sea ice. It is clear that coastal habitats essential to gentoo penguins during the breeding season are similarly critical during winter. Larger movements of birds from northern colonies in the WAP further suggest that leap-frog migration may influence colonization events by facilitating nest-area prospecting and use of new haul-out sites. Our results support efforts to develop a marine protected area around the WAP. Winter habitats used by gentoo penguins outline high priority areas for improving the management of the spatio-temporally concentrated krill ( Euphausia superba ) fishery that operates in this region during winter.

Existence and Features of the Myodural Bridge in Gentoo Penguins: a morphological study

Recent studies have evidenced that the anatomical structure now known as the myodural bridge (MDB) connects the suboccipital musculature to the cervical spinal dura mater (SDM). In humans, the MDB passes through both the posterior atlanto-occipital and the posterior atlanto-axial interspaces. The present authors suggest that the MDB has important physiological functions in humans. The existence of the MDB in various mammals, including flying birds (Rock pigeons and Gallus domesticus) has been previously validated. Gentoo penguins are marine birds, able to make 450 dives per day, reaching depths of up to 660 feet. Gentoo penguins are also the world’s fastest diving birds. The present study was therefore carried out to investigate the existence and characteristics of the MDB in Gentoo penguin (Pygoscelis papua), a non-flying, marine bird that can dive. While foraging, this penguin is able to reach speeds of up to 22 miles per hour. For this study, six Gentoo penguin specimens were dissected to observe the existence and composition of their MDB. Histological staining was also performed to analyze the anatomic relationships and characteristic of the MDB in the Gentoo penguin. In this study, it was found that the suboccipital musculature in the Gentoo penguin consists of the rectus capitis dorsalis minor (RCDmi) muscle and rectus capitis dorsalis major (RCDma) muscle. Dense connective tissue fibers were observed connecting these two suboccipital muscles to the spinal dura mater (SDM). This dense connective tissue bridge consists of primarily type I collagen fibers. Thus, this penguin’s MDB appears to be analogous to the MDB previously observed in humans. The present study evidences that the MDB not only exists in penguins but it also has unique features that distinguishes it from that of flying birds. Thus, this study advances the understanding of the morphological characteristics of the MDB in flightless, marine birds.

Diminution of real power loss by novel gentoo penguin algorithm

<span lang="EN-US">In this paper Gentoo Penguin Algorithm (GPA) is proposed to solve optimal reactive power problem. Gentoo Penguins preliminary population possesses heat radiation and magnetizes each other by absorption coefficient. Gentoo Penguins will move towards further penguins which possesses low cost (elevated heat concentration) of absorption. Cost is defined by the heat concentration, distance. Gentoo Penguins penguin attraction value is calculated by the amount of heat prevailed between two Gentoo penguins. Gentoo Penguins heat radiation is measured as linear. Less heat is received in longer distance, in little distance, huge heat is received. Gentoo Penguin Algorithm has been tested in standard IEEE 57 bus test system and simulation results show the projected algorithm reduced the real power loss considerably.</span>