326 research outputs found

    Metagenomic Analysis of Microbial 18s Eukaryotes Communities and Environmental factors in the Western Antarctic Peninsula waters during Austral Summers

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    Little is known about the environmental factors that impact eukaryotic microbial populations in the Western Antarctic Peninsula. Metagenomic and environmental data have been collected over the course of three consecutive austral summers in the Western Antarctic Peninsula off Palmer Station. More than 13 million 18S rRNA eukaryotic sequences have been taxonomically identified and categorized from the Antarctic water samples collected. Here we will investigate the environmental factors that affect eukaryotic organism populations, as well as possible indicator species that could provide insight as to the status of other eukaryotic species. Due to climate change, understanding these factors and identifying status indicating species is becoming increasingly important in understanding microbial systems, and to inform future research of Antarctic ecosystems and environmental conditions. We identified several groupings of correlated taxonomic operational units. Additionally, we found that Stramenopiles.Diatomea.ME-Euk-FW10, an uncultured diatom with a large population presence, had a particularly strong correlation to temperature

    Lawmakers as Lawbreakers

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    How would Congress act in a world without judicial review? Canlawmakers be trusted to police themselves? This Article examinesCongress’s capacity and incentives to enforce upon itself “the law ofcongressional lawmaking”—a largely overlooked body of law that iscompletely insulated from judicial enforcement. The Article exploresthe political safeguards that may motivate lawmakers to engage inself-policing and rule-following behavior. It identifies the majorpolitical safeguards that can be garnered from the relevant legal,political science, political economy, and social psychology scholarship,and evaluates each safeguard by drawing on a combination oftheoretical, empirical, and descriptive studies about Congress. TheArticle’s main argument is that the political safeguards that scholarsand judges commonly rely upon to constrain legislative behavioractually motivate lawmakers to be lawbreakers. In addition to providing insights about Congress’s behavior in theabsence of judicial review, this Article’s examination contributes tothe debate about judicial review of the legislative process, the generaldebate on whether political safeguards reduce the need for judicialreview, and the burgeoning new scholarship about legislative rules

    A New Nuclear Function of the Entamoeba histolytica Glycolytic Enzyme Enolase: The Metabolic Regulation of Cytosine-5 Methyltransferase 2 (Dnmt2) Activity

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    Cytosine-5 methyltransferases of the Dnmt2 family function as DNA and tRNA methyltransferases. Insight into the role and biological significance of Dnmt2 is greatly hampered by a lack of knowledge about its protein interactions. In this report, we address the subject of protein interaction by identifying enolase through a yeast two-hybrid screen as a Dnmt2-binding protein. Enolase, which is known to catalyze the conversion of 2-phosphoglycerate (2-PG) to phosphoenolpyruvate (PEP), was shown to have both a cytoplasmatic and a nuclear localization in the parasite Entamoeba histolytica. We discovered that enolase acts as a Dnmt2 inhibitor. This unexpected inhibitory activity was antagonized by 2-PG, which suggests that glucose metabolism controls the non-glycolytic function of enolase. Interestingly, glucose starvation drives enolase to accumulate within the nucleus, which in turn leads to the formation of additional enolase-E.histolytica DNMT2 homolog (Ehmeth) complex, and to a significant reduction of the tRNAAsp methylation in the parasite. The crucial role of enolase as a Dnmt2 inhibitor was also demonstrated in E.histolytica expressing a nuclear localization signal (NLS)-fused-enolase. These results establish enolase as the first Dnmt2 interacting protein, and highlight an unexpected role of a glycolytic enzyme in the modulation of Dnmt2 activity

    Expression of bovine leukemia virus ENV glycoprotein in insect cells by recombinant baculovirus

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    AbstractThe gp51-p30 glycoprotein constituting BLV envelope was expressed in Sf-21 insect cells by means of recombinant baculoviruses. Post-infection cell lysates were analyzed, in order to define the immunologic reactivity of recombinant products. Oligosaccharide chains, containing N-acetylglucosamine, mannose, galactose and sialic acid were found on recombinant gp51-p30. In order to investigate the timing of transcription and translation of the glycoprotein, kinetic assays were carried out on cell lysates and directly in situ on Sf-21 cells during the course of baculovirus infection. The use of different solubilizing reagents was also evaluated in order to rescue recombinant glycoprotein from its subcellular location

    Hydrothermal formation of fibrous mineral structures: The role on strength and mode of failure

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    Studying the mechanisms that control the rheology of rocks and geomaterials is crucial as much for predicting geological processes as for functionalizing geomaterials. That requires the understanding of how structural arrangements at the micro and nano scale control the physical and mechanical properties at the macroscopic scale. This is an area of rock physics still in its infancy. In this paper, we focus the attention on the formation of cementitious phases made of micro- and nano-scale fibrous structures, and the controls of the arrangement of these phases on mechanical properties. We use hydrothermal synthesis, and the properties of hydrothermal water, to promote the growth of fibrous mineral phases having nano-size diameter and length of a few microns, creating disordered and entangled mats of fibrous bundles as those found in natural samples. We draw inferences from structural microscopy to inform a statistical model that establishes an interdependence between structural parameters of fibrous structures and bulk mechanical response. Structural parameters include number and length of fibers, spatial orientation, and fraction of fibrous threads bearing the load. Mechanical properties include strength and mode of failure. Results show that as the fibrous microstructure evolves from ordered and aligned to disordered and entangled, the mechanical response of the fibrous composite transitions from a brittle to ductile behavior. Furthermore, the disordered and entangled microstructure exhibits lower strength at failure though strength increases as the number of fibers within the microstructure increases. Finally, the longer the entangled fiber, the larger the strain that the matrix can accommodate. The value of this study lies in further understanding fault healing through hydrothermal fluids and how the physical properties of fibrous microstructures resulting from it control brittle-ductile transitions, and possibly, slow slip events along subduction zones

    An innovative tool to assess the functional resilience of a school system: learning from the COVID-19 pandemic

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    IntroductionPreparing the school system for a future crisis requires the ability to examine the effectiveness of schools’ functioning during distant learning and their level of preparedness for future crises. Functional resilience (FR) is defined as the ability to maintain vital operational continuity in the face of disturbance. The study objectives included to develop a FR index of schools and to evaluate and validate it.MethodsTo enable examination of the study objectives, the study design included tool development, followed by a validation process among 20 content experts. Concurrently, an eDelphi process for building an inclusive index, based on various components of resilience was conducted. The final study tool consists of four tailored questionnaires to examine perceptions of key stakeholders, i.e.- teachers, principals, parents, and highschool students regarding communication, psychosocial aspects, perceived stress, infrastructure, resources, pedagogic support, digital literacy, and perceived FR. Using an internet panel, the tool was disseminated cross-sectionally among the four groups of stakeholders.ResultsThe results showed high reliability of most of the scales developed. Furthermore, a high consensus level was reached on the relative importance of each component/ stakeholder to the schools FR. The findings further suggest that there were no significant differences in the composite FR score based on characteristics such as school type/ size/geographic location. However, the findings revealed interesting variations among stakeholders, with findings suggesting greater vulnerability among some.DiscussionTo increase resilience and preparedness for future adversities that school systems may face, it is recommended to periodically incorporate an assessment based on a structured tool
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