143 research outputs found

    The Structure and Function of Enzyme 42

    Get PDF
    In the video game Subnautica, Enzyme 42 is an enzyme produced by the Sea Emperor Leviathan. It is able to destroy the Kharaa bacterium, a disease-causing pathogen. The structure of an enzyme is often specific to its function. This paper unites the function of Enzyme 42 with a hypothetical structure, based on both its purpose in Subnautica, and real enzymes with similar functions

    Issues associated with the formation of the ocean by SCP-045

    Get PDF
    Within the creative writing universe of the SCP Foundation, SCP-045 is an object that formed the Earth’s oceans through magical conversion of gaseous nitrogen to liquid water. This conversion would require a large mass of gaseous nitrogen, as well as enough time for it to be converted. It also requires SCP-045 to be continuously supplied with new gaseous nitrogen. This paper discusses some of the different environmental constraints on SCP-045’s ability to convert enough nitrogen into liquid water to form Earth’s entire ocean

    Potential adaptations of an E. Coli Colony on the surface of Venus

    Get PDF
    The conditions of the surface of Venus are extremely harsh, and there is no naturally evolved life on Venus. E. coli is a bacteria with a number of subtypes and adaptations to varying environments. This paper covers a number of adaptations a theoretical colony of E. coli bacteria could evolve, based on pre-existing adaptations of E. coli to its natural environments

    Ohmic Dissipation in the Atmospheres of Hot Jupiters

    Full text link
    Hot Jupiter atmospheres exhibit fast, weakly-ionized winds. The interaction of these winds with the planetary magnetic field generates drag on the winds and leads to ohmic dissipation of the induced electric currents. We study the magnitude of ohmic dissipation in representative, three-dimensional atmospheric circulation models of the hot Jupiter HD 209458b. We find that ohmic dissipation can reach or exceed 1% of the stellar insolation power in the deepest atmospheric layers, in models with and without dragged winds. Such power, dissipated in the deep atmosphere, appears sufficient to slow down planetary contraction and explain the typically inflated radii of hot Jupiters. This atmospheric scenario does not require a top insulating layer or radial currents that penetrate deep in the planetary interior. Circulation in the deepest atmospheric layers may actually be driven by spatially non-uniform ohmic dissipation. A consistent treatment of magnetic drag and ohmic dissipation is required to further elucidate the consequences of magnetic effects for the atmospheres and the contracting interiors of hot Jupiters.Comment: Accepted to the Astrophysical Journa

    Racism and Medical Care: Intersectional Analysis of Covid-19 Treatment

    Get PDF
    It is crucial to analyze the ways in which Black women are discriminated against in the United States healthcare system. As a nation, we are witnessing in real-time the ramifications of the inadequate care Black women commonly receive during the Covid-19 pandemic, however this is historically only one stage of many where Black women suffer at the hands of prejudiced medical treatment. Leading research on the subject presents quantitative data and patient interviews that provide evidence for systemic, discriminatory treatment on the part of healthcare providers. We are looking at patient/health care provider interaction, levels of satisfaction in the care that Black women receive, and differential medical outcomes as a result of varying levels of care. We structured this information around interviews with researchers at Binghamton University to gather personal narratives and advice for the trajectory of our research. Further, we have conducted a meta-analysis of womanist literature on the subject. With this information we provide an updated synopsis of the inequities in medical outreach, treatment, and the care that Black women receive, specifically regarding Covid-19, which manifests in lower confidence in medical professionals, higher infection rates, and higher death rates. Our data collection will assist in delineating this problem and in working towards solutions within the scope of the pandemic and beyond. Black women who face these disparities in health care are left to manage their health without the help of the very people tasked with that responsibility, and it is therefore imperative that we shine light upon the racism and sexism within the United States healthcare system to supply data in support of the demands for reform.https://orb.binghamton.edu/research_days_posters_2021/1043/thumbnail.jp

    Atmospheric Circulation of Hot Jupiters: A Shallow Three-Dimensional Model

    Full text link
    Remote observing of exoplanetary atmospheres is now possible, offering us access to circulation regimes unlike any of the familiar Solar System cases. Atmospheric circulation models are being developed to study these new regimes but model validations and intercomparisons are needed to establish their consistency and accuracy. To this end, we present a simple Earth-like validation of the pseudo-spectral solver of meteorological equations called IGCM (Intermediate General Circulation Model), based on Newtonian relaxation to a prescribed latitudinal profile of equilibrium temperatures. We then describe a straightforward and idealized model extension to the atmospheric flow on a hot Jupiter with the same IGCM solver. This shallow, three-dimensional hot Jupiter model is based on Newtonian relaxation to a permanent day-night pattern of equilibrium temperatures and the absence of surface drag. The baroclinic regime of the Earth's lower atmosphere is contrasted with the more barotropic regime of the simulated hot Jupiter flow. For plausible conditions at the 0.1-1 bar pressure level on HD 209458b, the simulated flow is characterized by unsteadiness, subsonic wind speeds, a zonally-perturbed superrotating equatorial jet and large scale polar vortices. Violation of the Rayleigh-Kuo inflexion point criterion on the flanks of the accelerating equatorial jet indicates that barotropic (horizontal shear) instabilities may be important dynamical features of the simulated flow. Similarities and differences with previously published simulated hot Jupiter flows are briefly noted.Comment: 31 pages, 9 figures, accepted for publication in ApJ. Version with hi-res figures: http://www.astro.columbia.edu/~kristen/Hires/hotjup.3d.shallow.ps.g

    Human Faces Are Slower than Chimpanzee Faces

    Get PDF
    BACKGROUND: While humans (like other primates) communicate with facial expressions, the evolution of speech added a new function to the facial muscles (facial expression muscles). The evolution of speech required the development of a coordinated action between visual (movement of the lips) and auditory signals in a rhythmic fashion to produce "visemes" (visual movements of the lips that correspond to specific sounds). Visemes depend upon facial muscles to regulate shape of the lips, which themselves act as speech articulators. This movement necessitates a more controlled, sustained muscle contraction than that produced during spontaneous facial expressions which occur rapidly and last only a short period of time. Recently, it was found that human tongue musculature contains a higher proportion of slow-twitch myosin fibers than in rhesus macaques, which is related to the slower, more controlled movements of the human tongue in the production of speech. Are there similar unique, evolutionary physiologic biases found in human facial musculature related to the evolution of speech?\ud \ud METHODOLOGY/PRINICIPAL FINDINGS: Using myosin immunohistochemistry, we tested the hypothesis that human facial musculature has a higher percentage of slow-twitch myosin fibers relative to chimpanzees (Pan troglodytes) and rhesus macaques (Macaca mulatta). We sampled the orbicularis oris and zygomaticus major muscles from three cadavers of each species and compared proportions of fiber-types. Results confirmed our hypothesis: humans had the highest proportion of slow-twitch myosin fibers while chimpanzees had the highest proportion of fast-twitch fibers.\ud \ud CONCLUSIONS/SIGNIFICANCE: These findings demonstrate that the human face is slower than that of rhesus macaques and our closest living relative, the chimpanzee. They also support the assertion that human facial musculature and speech co-evolved. Further, these results suggest a unique set of evolutionary selective pressures on human facial musculature to slow down while the function of this muscle group diverged from that of other primates.\ud \u

    Three Dimensional Modeling of Hot Jupiter Atmospheric Flows

    Full text link
    We present a three dimensional hot Jupiter model, extending from 200 bar to 1 mbar, using the Intermediate General Circulation Model from the University of Reading. Our horizontal spectral resolution is T31 (equivalent to a grid of 48x96), with 33 logarithmically spaced vertical levels. A simplified (Newtonian) scheme is employed for the radiative forcing. We adopt a physical set up nearly identical to the model of HD 209458b by Cooper & Showman (2005,2006) to facilitate a direct model inter-comparison. Our results are broadly consistent with theirs but significant differences also emerge. The atmospheric flow is characterized by a super-rotating equatorial jet, transonic wind speeds, and eastward advection of heat away from the dayside. We identify a dynamically-induced temperature inversion ("stratosphere") on the planetary dayside and find that temperatures at the planetary limb differ systematically from local radiative equilibrium values, a potential source of bias for transit spectroscopic interpretations. While our model atmosphere is quasi-identical to that of Cooper & Showman (2005,2006) and we solve the same meteorological equations, we use different algorithmic methods, spectral-implicit vs. grid-explicit, which are known to yield fully consistent results in the Earth modeling context. The model discrepancies identified here indicate that one or both numerical methods do not faithfully capture all of the atmospheric dynamics at work in the hot Jupiter context. We highlight the emergence of a shock-like feature in our model, much like that reported recently by Showman et al. (2009), and suggest that improved representations of energy conservation may be needed in hot Jupiter atmospheric models, as emphasized by Goodman (2009).Comment: 25 pages, 6 figures, minor revisions, ApJ accepted, version with hi-res figures: http://www.astro.columbia.edu/~kristen/Hires/hotjup.3d.deep.ps.g

    Radiation-Hydrodynamics of Hot Jupiter Atmospheres

    Full text link
    Radiative transfer in planetary atmospheres is usually treated in the static limit, i.e., neglecting atmospheric motions. We argue that hot Jupiter atmospheres, with possibly fast (sonic) wind speeds, may require a more strongly coupled treatment, formally in the regime of radiation-hydrodynamics. To lowest order in v/c, relativistic Doppler shifts distort line profiles along optical paths with finite wind velocity gradients. This leads to flow-dependent deviations in the effective emission and absorption properties of the atmospheric medium. Evaluating the overall impact of these distortions on the radiative structure of a dynamic atmosphere is non-trivial. We present transmissivity and systematic equivalent width excess calculations which suggest possibly important consequences for radiation transport in hot Jupiter atmospheres. If winds are fast and bulk Doppler shifts are indeed important for the global radiative balance, accurate modeling and reliable data interpretation for hot Jupiter atmospheres may prove challenging: it would involve anisotropic and dynamic radiative transfer in a coupled radiation-hydrodynamical flow. On the bright side, it would also imply that the emergent properties of hot Jupiter atmospheres are more direct tracers of their atmospheric flows than is the case for Solar System planets. Radiation-hydrodynamics may also influence radiative transfer in other classes of hot exoplanetary atmospheres with fast winds.Comment: 25 pages, 4 figures, accepted for publication in ApJ (minor revisions
    • …
    corecore