61 research outputs found
Trace Fossils from the Shawangunk Formation in the Hudson Valley Indicate an Estuarine Depositional Environment
The Middle Silurian Shawangunk Formation crops out in the lower Hudson Valley and extends toward the southwest into New Jersey and Pennsylvania. It reaches a maximum thickness around Guymard (1,400 ft.; 400m) and gradually thins toward the northeast, pinching out near Binnewater, New York. The formation consists of gray conglomerate, quartz arenite, and minor shale. Worm burrows, Arthrophycus, Skolithos, Planolites?, and a bilobed resting trace have been found at different stratigraphic horizons in the Shawangunk Formation. All traces are associated with a finer, sandy matrix and/or hematite-rich interval rather than a coarse, pebbly quartz sandstone lithology dominant in the bulk of the unit, indicating a marine influence as well an environment with less energy than the braided stream environment inferred for most of the formation. Rivers and streams moving away from the eastern Taconic Mountains flowed into a westerly situated shallow marine basin. Eurypterids have previously been found on approximately the same stratigraphic levels as the traces and may be useful for constraining the depositional environment of these beds. Silurian eurypterids, now largely considered euryhaline, suggest that the environment of deposition was a marine-influenced estuary based on recent work documenting autochthonous assemblages of similar taxa in marginal marine settings. Association of eurypterids with Arthrophycus-dominated ichnofacies has been noted elsewhere in the Lower Silurian Tuscarora Formation in central Pennsylvania, suggesting a recurrent nearshore benthic assemblage
Epstein-Barr Virus LMP2A Reduces Hyperactivation Induced by LMP1 to Restore Normal B Cell Phenotype in Transgenic Mice
Epstein-Barr virus (EBV) latently infects most of the human population and is strongly associated with lymphoproliferative disorders. EBV encodes several latency proteins affecting B cell proliferation and survival, including latent membrane protein 2A (LMP2A) and the EBV oncoprotein LMP1. LMP1 and LMP2A signaling mimics CD40 and BCR signaling, respectively, and has been proposed to alter B cell functions including the ability of latently-infected B cells to access and transit the germinal center. In addition, several studies suggested a role for LMP2A modulation of LMP1 signaling in cell lines by alteration of TRAFs, signaling molecules used by LMP1. In this study, we investigated whether LMP1 and LMP2A co-expression in a transgenic mouse model alters B cell maturation and the response to antigen, and whether LMP2A modulates LMP1 function. Naïve LMP1/2A mice had similar lymphocyte populations and antibody production by flow cytometry and ELISA compared to controls. In the response to antigen, LMP2A expression in LMP1/2A animals rescued the impairment in germinal center generation promoted by LMP1. LMP1/2A animals produced high-affinity, class-switched antibody and plasma cells at levels similar to controls. In vitro, LMP1 upregulated activation markers and promoted B cell hyperproliferation, and co-expression of LMP2A restored a wild-type phenotype. By RT-PCR and immunoblot, LMP1 B cells demonstrated TRAF2 levels four-fold higher than non-transgenic controls, and co-expression of LMP2A restored TRAF2 levels to wild-type levels. No difference in TRAF3 levels was detected. While modulation of other TRAF family members remains to be assessed, normalization of the LMP1-induced B cell phenotype through LMP2A modulation of TRAF2 may be a pathway by which LMP2A controls B cell function. These findings identify an advance in the understanding of how Epstein-Barr virus can access the germinal center in vivo, a site critical for both the genesis of immunological memory and of virus-associated tumors
Discordant retention of HIV-infected mothers and children
It is often assumed that children and their caregivers either stay in care together or discontinue together, but data is lacking on caregiver-child retention concordance. We sought to describe the pattern of care among a cohort of human immunodeficiency virus (HIV) infected children and mothers enrolled in care at the Manhiça District Hospital (MDH).This was a retrospective review of routine HIV clinical data collected under a larger prospective HIV cohort study at MDH. Children enrolling HIV care from January 2013 to November 2016 were identified and matched to their mother's HIV clinical data. Retention in care for mothers and children was assessed at 24 months after the child's enrolment. Multinomial logistic regression was performed to evaluate variables associated with retention discordance.For the 351 mother-child pairs included in the study, only 39% of mothers had concordant care status at baseline (23% already active in care, 16% initiated care concurrently with their children). At 24-months follow up, a total of 108 (31%) mother-child pairs were concordantly retained in care, 88 (26%) pairs were concordantly lost to follow up (LTFU), and 149 (43%) had discordant retention. Pairs with concurrent registration had a higher probability of being concordantly retained in care. Children who presented with advanced clinical or immunological stage had increased probability of being concordantly LTFU.High rates of LTFU as well as high proportions of discordant retention among mother-child pairs were found. Prioritization of a family-based care model that has the potential to improve retention for children and caregivers is recommended
Supplemental Table 1
Raw locality, age, stratigraphic, lithological, sedimentological, faunal, and reference data used in this study
Supplemental Table 3
Raw data for binomal substrate affinity analysis
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