The atmospheric circulation of the super Earth GJ 1214b: Dependence on composition and metallicity

We present three-dimensional atmospheric circulation models of GJ 1214b, a 2.7 Earth-radius, 6.5 Earth-mass super Earth detected by the MEarth survey. Here we explore the planet's circulation as a function of atmospheric metallicity and atmospheric composition, modeling atmospheres with a low mean-molecular weight (i.e., H2-dominated) and a high mean-molecular weight (i.e. water- and CO2-dominated). We find that atmospheres with a low mean-molecular weight have strong day-night temperature variations at pressures above the infrared photosphere that lead to equatorial superrotation. For these atmospheres, the enhancement of atmospheric opacities with increasing metallicity lead to shallower atmospheric heating, larger day-night temperature variations and hence stronger superrotation. In comparison, atmospheres with a high mean-molecular weight have larger day-night and equator-to-pole temperature variations than low mean-molecular weight atmospheres, but differences in opacity structure and energy budget lead to differences in jet structure. The circulation of a water-dominated atmosphere is dominated by equatorial superrotation, while the circulation of a CO2-dominated atmosphere is instead dominated by high-latitude jets. By comparing emergent flux spectra and lightcurves for 50x solar and water-dominated compositions, we show that observations in emission can break the degeneracy in determining the atmospheric composition of GJ 1214b. The variation in opacity with wavelength for the water-dominated atmosphere leads to large phase variations within water bands and small phase variations outside of water bands. The 50x solar atmosphere, however, yields small variations within water bands and large phase variations at other characteristic wavelengths. These observations would be much less sensitive to clouds, condensates, and hazes than transit observations.Comment: 12 pages, 11 figures, 2 tables, accepted to Ap

Ponesimod, a selective S1P1 receptor modulator: a potential treatment for multiple sclerosis and other immune-mediated diseases

The first oral treatment for relapsing multiple sclerosis, the nonselective sphingosine-1-phosphate receptor (S1PR) modulator fingolimod, led to identification of a pivotal role of sphingosine-1-phosphate and one of its five known receptors, S1P(1)R, in regulation of lymphocyte trafficking in multiple sclerosis. Modulation of S1P3R, initially thought to cause some of fingolimod's side effects, prompted the search for novel compounds with high selectivity for S1P1R. Ponesimod is an orally active, selective S1P(1)R modulator that causes dose-dependent sequestration of lymphocytes in lymphoid organs. In contrast to the long half-life/slow elimination of fingolimod, ponesimod is eliminated within 1 week of discontinuation and its pharmacological effects are rapidly reversible. Clinical data in multiple sclerosis have shown a dose-dependent therapeutic effect of ponesimod and defined 20mg as a daily dose with desired efficacy, and acceptable safety and tolerability. Phase II clinical data have also shown therapeutic efficacy of ponesimod in psoriasis. These findings have increased our understanding of psoriasis pathogenesis and suggest clinical utility of S1P(1)R modulation for treatment of various immune-mediated disorders. A gradual dose titration regimen was found to minimize the cardiac effects associated with initiation of ponesimod treatment. Selectivity for S1P(1)R, rapid onset and reversibility of pharmacological effects, and an optimized titration regimen differentiate ponesimod from fingolimod, and may lead to better safety and tolerability. Ponesimod is currently in phase III clinical development to assess efficacy and safety in relapsing multiple sclerosis. A phase II study is also ongoing to investigate the potential utility of ponesimod in chronic graft versus host disease

The Effects of Access Restrictions and Communication Strategies for Divisive Environmental Management

In 2018, the U.S. National Park Service announced a controversial plan to translocate 20−30 gray wolves (Canis lupus) to Isle Royale National Park to increase genetic diversity and ultimately the dwindling wolf population. Media were restricted physical access during the translocations, citing safety concerns for the wolves and management team, as well as logistical challenges because of the remoteness of the park. Given these restrictions, we used interviews and quantitative analyses of news stories and press releases to examine what communication strategies the National Park Service and its partners deployed and how access restriction affected the way news outlets covered the events. By identifying source diversity groups, we found U.S. government sources were predominately featured with few other source types included, and that coverage heavily relied on press release information. We discuss the implications of this communication strategy and potential consequences for access restrictions when covering divisive events in remote locations

Web Services: Enabling Dynamic Business Networks

A Dynamic Business Network is a distinct system of participants (customers, suppliers, complimentors, competitors, service providers) that use the network to achieve customer satisfaction and profitability and where participants and relationships evolve over time. However, unpredictability and rapid change in a Dynamic Business Network creates a significant challenge in implementing and supporting business application software. Traditional information systems implementation methods require an a priori design and are built for a particular purpose for use over an extended period of time. Loosely coupled business networks change interrelationships between nodes both quickly and frequently, thus providing little or no notice for planning, implementing, or changing the supporting applications. The dynamic sourcing capabilities of the emerging Web Services framework provide a key to enabling these complex eco-systems. We explore the strategic and technological dimensions of Web Services and describe how they can be used to support dynamic business networks