437 research outputs found
Development of Preventive Measures to Reduce Mortalities for Holding Live Wild-caught Flounder in Recirculating Aquaculture Systems
A substantial high-value market exists for wild-caught live summer flounder (Paralichthys dentatus). An important component of accessing this market is the ability to hold wild-caught flounder in land based recirculating aquaculture systems (RAS). A major constraint to holding summer flounder in land-based RAS is fish mortalities associated with the ectoparasite argulus spp. Very little information exists that provides a live flounder holding facility with FDA approved treatment options to prevent introduction of argulus from wild caught fish into holding systems. The project objective was to test the available FDA approved chemotherapeutics for treatment of ectoparasite infections in summer flounder. To validate treatment efficacy, 8 infected individuals were treated with bath treatments according to maximum recommended doses (250ppm formalin for 60 m; 200 ppm hydrogen peroxide for 30 m; and freshwater for 20 m) and then transferred to separate RAS to monitor for two weeks. Daily observations were made to determine if treatments were lethal to the attached argulus. Following the two week monitoring period, fish from all treatments showed no sign of a reduction in attached argulus. According to the findings of this study, there are currently no FDA approved treatments for argulus infections on summer flounder. It is recommended that a live wild flounder holding facility visually inspect all incoming fish for the presence of argulus and maintain fish in a quarantine system prior to holding in a RAS
Dynamics of former ice lobes of the southernmost Patagonian Ice Sheet based on a glacial landsystems approach
Social learning as a link between the individual and the collective: evaluating deliberation on social values
The role of social learning in deliberative processes is an emerging area of research in sustainability science. Functioning as a link between the individual and the collective, social learning has been envisioned as a process that can empower and give voice to a diverse set of stakeholder viewpoints, contribute to more adaptive and resilient management decisions and foster broader societal transformations. However, despite its widespread use in the context of participatory management of natural resources, the empirical properties of social learning remain understudied. This paper evaluates the role of social interaction and social capital in achieving transformative learning in discussions about social values. We employ a longitudinal design involving three consecutive surveys of 25 participants of an expert workshop focused on social values, as well as approximately 12 hours of transcribed audio and video recordings of participant interactions. Our mixed methods approach demonstrates the potential of using changes in social networks and definitions of social values that emerge from qualitative coding as indicators of social learning. We find that individuals with a weaker conceptual understanding of social values are more likely to change their definitions of the concept after deliberation. Though slight, these changes display a shift towards definitions more firmly held by other group members.Peer reviewe
Simulating Descent and Landing of a Spacecraft
The Dynamics Simulator for Entry, Descent, and Surface landing (DSENDS) software performs high-fidelity simulation of the Entry, Descent, and Landing (EDL) of a spacecraft into the atmosphere and onto the surface of a planet or a smaller body. DSENDS is an extension of the DShell and DARTS programs, which afford capabilities for mathematical modeling of the dynamics of a spacecraft as a whole and of its instruments, actuators, and other subsystems. DSENDS enables the modeling (including real-time simulation) of flight-train elements and all spacecraft responses during various phases of EDL. DSENDS provides high-fidelity models of the aerodynamics of entry bodies and parachutes plus supporting models of atmospheres. Terrain and real-time responses of terrain-imaging radar and lidar instruments can also be modeled. The program includes modules for simulation of guidance, navigation, hypersonic steering, and powered descent. Automated state-machine-driven model switching is used to represent spacecraft separations and reconfigurations. Models for computing landing contact and impact forces are expected to be added. DSENDS can be used as a stand-alone program or incorporated into a larger program that simulates operations in real time
Hepatitis C Virus Indirectly Disrupts DNA Damage-Induced p53 Responses by Activating Protein Kinase R
ABSTRACT Many DNA tumor viruses promote cellular transformation by inactivating the critically important tumor suppressor protein p53. In contrast, it is not known whether p53 function is disrupted by hepatitis C virus (HCV), a unique, oncogenic RNA virus that is the leading infectious cause of liver cancer in many regions of the world. Here we show that HCV-permissive, liver-derived HepG2 cells engineered to constitutively express microRNA-122 (HepG2/miR-122 cells) have normal p53-mediated responses to DNA damage and that HCV replication in these cells potently suppresses p53 responses to etoposide, an inducer of DNA damage, or nutlin-3, an inhibitor of p53 degradation pathways. Upregulation of p53-dependent targets is consequently repressed within HCV-infected cells, with potential consequences for cell survival. Despite this, p53 function is not disrupted by overexpression of the complete HCV polyprotein, suggesting that altered p53 function may result from the host response to viral RNA replication intermediates. Clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9-mediated ablation of double-stranded RNA (dsRNA)-activated protein kinase R (PKR) restored p53 responses while boosting HCV replication, showing that p53 inhibition results directly from viral activation of PKR. The hepatocellular abundance of phosphorylated PKR is elevated in HCV-infected chimpanzees, suggesting that PKR activation and consequent p53 inhibition accompany HCV infection in vivo . These findings reveal a feature of the host response to HCV infection that may contribute to hepatocellular carcinogenesis. IMPORTANCE Chronic infection with hepatitis C virus (HCV) is the leading cause of liver cancer in most developed nations. However, the mechanisms whereby HCV infection promotes carcinogenesis remain unclear. Here, we demonstrate that HCV infection inhibits the activation of p53 following DNA damage. Contrary to previous reports, HCV protein expression is insufficient to inhibit p53. Rather, p53 inhibition is mediated by cellular protein kinase R (PKR), which is activated by HCV RNA replication and subsequently suppresses global protein synthesis. These results redefine our understanding of how HCV infection influences p53 function. We speculate that persistent disruption of p53-mediated DNA damage responses may contribute to hepatocellular carcinogenesis in chronically infected individuals
Genomic and panproteomic analysis of the development of infant immune responses to antigenically-diverse pneumococci
Streptococcus pneumoniae (pneumococcus) is a nasopharyngeal commensal and respiratory pathogen. This study characterises the immunoglobulin G (IgG) repertoire recognising pneumococci from birth to 24 months old (mo) in a prospectively-sampled cohort of 63 children using a panproteome array. IgG levels are highest at birth, due to transplacental transmission of maternal antibodies. The subsequent emergence of responses to individual antigens exhibit distinct kinetics across the cohort. Stable differences in the strength of individuals’ responses, correlating with maternal IgG concentrations, are established by 6 mo. By 12 mo, children develop unique antibody profiles that are boosted by re-exposure. However, some proteins only stimulate substantial responses in adults. Integrating genomic data on nasopharyngeal colonisation demonstrates rare pneumococcal antigens can elicit strong IgG levels post-exposure. Quantifying such responses to the diverse core loci (DCL) proteins is complicated by cross-immunity between variants. In particular, the conserved N terminus of DCL protein zinc metalloprotease B provokes the strongest early IgG responses. DCL proteins’ ability to inhibit mucosal immunity likely explains continued pneumococcal carriage despite hosts’ polyvalent antibody repertoire. Yet higher IgG levels are associated with reduced incidence, and severity, of pneumonia, demonstrating the importance of the heterogeneity in response strength and kinetics across antigens and individuals
Discovery and characterization of WASP-6b, an inflated sub-Jupiter mass planet transiting a solar-type star
We report the discovery of WASP-6b, an inflated sub-Jupiter mass planet transiting every 3.3610060^{\rm + 0.0000022 }_ days a mildly metal-poor solar-type star of magnitude V = 11.9. A combined analysis of the WASP photometry, high-precision followup transit photometry and radial velocities yield a planetary mass M_{\rm p} = 0.503^_ and radius R_{\rm p} = 1.224^_ , resulting in a density . The mass and radius for the host star are M_\ast = 0.88^_ and R_\ast = 0.870^_ . The non-zero orbital eccentricity e = 0.054^{\rm +0.018}_ that we measure suggests that the planet underwent a massive tidal heating ~1 Gyr ago that could have contributed to its inflated radius. High-precision radial velocities obtained during a transit allow us to measure a sky-projected angle between the stellar spin and orbital axis \beta = 11^_ deg. In addition to similar published measurements, this result favors a dominant migration mechanism based on tidal interactions with a protoplanetary disk
Differences in genotype and virulence among four multidrug-resistant <i>Streptococcus pneumoniae</i> isolates belonging to the PMEN1 clone
We report on the comparative genomics and characterization of the virulence phenotypes of four <i>S. pneumoniae</i> strains that belong to the multidrug resistant clone PMEN1 (Spain<sup>23F</sup> ST81). Strains SV35-T23 and SV36-T3 were recovered in 1996 from the nasopharynx of patients at an AIDS hospice in New York. Strain SV36-T3 expressed capsule type 3 which is unusual for this clone and represents the product of an in vivo capsular switch event. A third PMEN1 isolate - PN4595-T23 - was recovered in 1996 from the nasopharynx of a child attending day care in Portugal, and a fourth strain - ATCC700669 - was originally isolated from a patient with pneumococcal disease in Spain in 1984. We compared the genomes among four PMEN1 strains and 47 previously sequenced pneumococcal isolates for gene possession differences and allelic variations within core genes. In contrast to the 47 strains - representing a variety of clonal types - the four PMEN1 strains grouped closely together, demonstrating high genomic conservation within this lineage relative to the rest of the species. In the four PMEN1 strains allelic and gene possession differences were clustered into 18 genomic regions including the capsule, the blp bacteriocins, erythromycin resistance, the MM1-2008 prophage and multiple cell wall anchored proteins. In spite of their genomic similarity, the high resolution chinchilla model was able to detect variations in virulence properties of the PMEN1 strains highlighting how small genic or allelic variation can lead to significant changes in pathogenicity and making this set of strains ideal for the identification of novel virulence determinant
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