337 research outputs found

    Occurrence of Pulmonary Arteritis with Lungworm Infections in Gray Seals from New England, 2013-2020

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    Gray seals (Halichoerus grypus) are a common pinniped species in New England coastal waters. Parasitic infection is an important cause of mortality for this species, and lungworm species are frequently implicated in cases of respiratory infection, especially in pups and weanling seals. The most common of these is Otostrongylus circumlitus, a large nematode found in the bronchi and bronchioles of affected seals. The full life cycle is unknown but its presence in lungs and sometimes pulmonary arteries suggests that migration via arterial circulation occurs. Signs and microscopic findings are widely variable; our cases included dyspnea, bloody mucoid oral and nasal discharge, eosinophilic bronchitis/bronchiolitis, suppurative pneumonia, and pulmonary congestion and emphysema. Recent evidence suggests a possible increase in O. circumlitus respiratory infection among gray seals that includes arterial vasculitis lesions with deposition of Splendore-Hoeppli tissue and infiltrates of eosinophils. We aim to describe and document the occurrence of this lesion in cases of O. circumlitus in the gray seal population on Cape Cod, MA. Necropsy results including gross and histologic examination of lung were compiled for 34 gray seals, with 11 of these being diagnosed with pulmonary nematodiasis. Eight of the diagnosed nematodiasis cases were found to have concurrent arteritis. Work is ongoing to evaluate the changes in both the pathology and prevalence of this pathogen over time

    Histological evidence of trauma in tusks of southern African dicynodonts

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    Dicynodonts were a clade of globally-distributed therapsids known for their abundance in the fossil record and for surviving the Permo-Triassic mass extinction. The group had distinctive dental adaptations including a beak and, in many species, paired maxillary tusks. The function of these tusks has long been of interest, yet remains poorly understood.We report here on two instances of unusual morphology in tusk dentine from specimens of: 1) Lystrosaurus from the Karoo Basin of South Africa and, 2) an unidentified dicynodontoid from the Luangwa Basin of Zambia. In both, the cross-sectional shape of the tusk root is lobed and infolded, which histological features suggest is a result of abnormal dentine deposition. We infer that this abnormal morphology is likely the consequence of trauma given its reparative nature and structural similarities to trauma-related morphologies reported in the tusks of modern elephants. This study demonstrates that histological sampling of dicynodont tusks can shed light on the biology of this important clade of therapsids.National Geographic Exploration Grant NGS-158R-18 National Science Foundation PLR-1341304 National Science Foundation DEB-1701383 Palaeontological Scientific TrustJNC201

    The impact of early life immune challenge on behavior and microglia during postnatal development

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    Sexual dichotomy exists in the development, presentation, and course of many neuropsychiatric disorders, including anxiety. Anxiety disorders are one of the earliest psychiatric illnesses to manifest and a role for immune system programming of the developing CNS has emerged in relation to anxiety. Adult rodents neonatally exposed to an immune challenge exhibit increased anxiety-related behaviors. The objective of this study was to determine the impact of postnatal immune challenge on behavior and microglia during the postnatal period and in adulthood. Mice were administered lipopolysaccharide (LPS; 0.05mg/kg, i.p.) or saline on postnatal days (P) three and five. Anxiety-related behavior was assessed during early development on P15 and P21, and re-assessed in adulthood at 10 and 12 weeks. Results reveal sex-specificity in the temporal emergence and phenotypic profile of behaviors displayed by LPS-treated mice. Male LPS-treated mice exhibited reduced exploratory in early development (P15 and P21) that persisted into adulthood. Female LPS-mice exhibited increased anxiety-like behaviors in the EPM in adulthood. These results demonstrate a role for interactions between sex and the immune system in shaping the developmental trajectory of exploratory and anxiety-like behaviors

    Dinosaur biogeographic structure and Mesozoic continental fragmentation: a network-based approach

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    Aim: To reconstruct dinosaur macro-biogeographical patterns through the Mesozoic Era using a network-based approach. We test how continental fragmentation affected dinosaur macro-biogeographical structure and evolutionary rates. Location: A global occurrence database of dinosaur families from the Late Triassic to the end-Cretaceous was used for this study. Methods: Biogeographical and geographical network models were constructed. Continental landmasses were linked by direct continental contact and sea level (SL)-conditioned connections in geographical networks, and by shared dinosaur families in biogeographical networks. Biogeographical networks were run with raw, novel and first-step connections for all dinosaur, ornithischian, theropod, and sauropodomorph taxa. Results: Geographical connectedness declines through time, from peak aggregation in the Triassic–Jurassic to complete separation in the latest Cretaceous. Biogeographical connectedness shows no common trend in the raw and novel connection network models, but decreases through time while showing some correlation with continental fragmentation in most of the first-step network models. Despite continental isolation and high SLs, intercontinental faunal exchange continued right up to the end of the Cretaceous. Continental fragmentation and dinosaurian macro-biogeographical structure do not share a common pattern with dinosaurian evolutionary rates, although there is evidence that increased continental isolation resulted in increased origination rates in some dinosaurian lineages. Spatiotemporal sampling biases and early Mesozoic establishment of family-level distribution patterns are important drivers of apparent dinosaur macro-biogeographical structure. Main conclusions: There is some evidence to suggest that dinosaur macro-biogeographical structure was influenced by continental fragmentation, although intercontinental exchange of dinosaur faunas appears to have continued up to the end of the Cretaceous. Macro-biogeographical patterns are obscured by uneven geographical sampling through time and a residual earlier Mesozoic distribution which is sustained up to the end of the Cretaceous

    The earliest bird-line archosaurs and the assembly of the dinosaur body plan

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    © 2017 Macmillan Publishers Limited, part of Springer Nature. All rights reserved.The relationship between dinosaurs and other reptiles is well established, but the sequence of acquisition of dinosaurian features has been obscured by the scarcity of fossils with transitional morphologies. The closest extinct relatives of dinosaurs either have highly derived morphologies or are known from poorly preserved or incomplete material. Here we describe one of the stratigraphically lowest and phylogenetically earliest members of the avian stem lineage (Avemetatarsalia), Teleocrater rhadinus gen. et sp. nov., from the Middle Triassic epoch. The anatomy of T. rhadinus provides key information that unites several enigmatic taxa from across Pangaea into a previously unrecognized clade, Aphanosauria. This clade is the sister taxon of Ornithodira (pterosaurs and birds) and shortens the ghost lineage inferred at the base of Avemetatarsalia. We demonstrate that several anatomical features long thought to characterize Dinosauria and dinosauriforms evolved much earlier, soon after the bird-crocodylian split, and that the earliest avemetatarsalians retained the crocodylian-like ankle morphology and hindlimb proportions of stem archosaurs and early pseudosuchians. Early avemetatarsalians were substantially more species-rich, widely geographically distributed and morphologically diverse than previously recognized. Moreover, several early dinosauromorphs that were previously used as models to understand dinosaur origins may represent specialized forms rather than the ancestral avemetatarsalian morphology

    Development, validation, and utilization of a competitive enzyme-linked immunosorbent assay for the detection of antibodies against Brucella species in marine mammals

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    A competitive enzyme-linked immunosorbent assay (cELISA) was developed by using a whole-cell antigen from a marine Brucella sp. isolated from a harbor seal (Phoca vitulina). The assay was designed to screen sera from multiple marine mammal species for the presence of antibodies against marine-origin Brucella. Based on comparisons with culture-confirmed cases, specificity and sensitivity for cetacean samples tested were 73% and 100%, respectively. For pinniped samples, specificity and sensitivity values were 77% and 67%, respectively. Hawaiian monk seal (Monachus schauinslandi; n = 28) and bottlenose dolphin (Tursiops truncatus; n = 48) serum samples were tested, and the results were compared with several other assays designed to detect Brucella abortus antibodies. The comparison testing revealed the marine-origin cELISA to be more sensitive than the B. abortus tests by the detection of additional positive serum samples. The newly developed cELISA is an effective serologic method for detection of the presence of antibodies against marine-origin Brucella sp. in marine mammals

    Links between maternal postpartum depressive symptoms, maternal distress, infant gender and sensitivity in a high-risk population

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    <p>Abstract</p> <p>Background</p> <p>Maternal postpartum depression has an impact on mother-infant interaction. Mothers with depression display less positive affect and sensitivity in interaction with their infants compared to non-depressed mothers. Depressed women also show more signs of distress and difficulties adjusting to their role as mothers than non-depressed women. In addition, depressive mothers are reported to be affectively more negative with their sons than with daughters.</p> <p>Methods</p> <p>A non-clinical sample of 106 mother-infant dyads at psychosocial risk (poverty, alcohol or drug abuse, lack of social support, teenage mothers and maternal psychic disorder) was investigated with EPDS (maternal postpartum depressive symptoms), the CARE-Index (maternal sensitivity in a dyadic context) and PSI-SF (maternal distress). The baseline data were collected when the babies had reached 19 weeks of age.</p> <p>Results</p> <p>A hierarchical regression analysis yielded a highly significant relation between the PSI-SF subscale "parental distress" and the EPDS total score, accounting for 55% of the variance in the EPDS. The other variables did not significantly predict the severity of depressive symptoms. A two-way ANOVA with "infant gender" and "maternal postpartum depressive symptoms" showed no interaction effect on maternal sensitivity.</p> <p>Conclusions</p> <p>Depressive symptoms and maternal sensitivity were not linked. It is likely that we could not find any relation between both variables due to different measuring methods (self-reporting and observation). Maternal distress was strongly related to maternal depressive symptoms, probably due to the generally increased burden in the sample, and contributed to 55% of the variance of postpartum depressive symptoms.</p

    Inter- and intraobserver reliability of the MTM-classification for proximal humeral fractures: A prospective study

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    <p>Abstract</p> <p>Background</p> <p>A precise modular topographic-morphological (MTM) classification for proximal humeral fractures may address current classification problems. The classification was developed to evaluate whether a very detailed classification exceeding the analysis of fractured parts may be a valuable tool.</p> <p>Methods</p> <p>Three observers classified plain radiographs of 22 fractures using both a simple version (fracture displacement, number of parts) and an extensive version (individual topographic fracture type and morphology) of the MTM classification. Kappa-statistics were used to determine reliability.</p> <p>Results</p> <p>An acceptable reliability was found for the simple version classifying fracture displacement and fractured main parts. Fair interobserver agreement was found for the extensive version with individual topographic fracture type and morphology.</p> <p>Conclusion</p> <p>Although the MTM-classification covers a wide spectrum of fracture types, our results indicate that the precise topographic and morphological description is not delivering reproducible results. Therefore, simplicity in fracture classification may be more useful than extensive approaches, which are not adequately reliable to address current classification problems.</p
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