On the Emergent Spectra of Hot Protoplanet Collision Afterglows

We explore the appearance of terrestrial planets in formation by studying the emergent spectra of hot molten protoplanets during their collisional formation. While such collisions are rare, the surfaces of these bodies may remain hot at temperatures of 1000-3000 K for up to millions of years during the epoch of their formation. These object are luminous enough in the thermal infrared to be observable with current and next generation optical/IR telescopes, provided that the atmosphere of the forming planet permits astronomers to observe brightness temperatures approaching that of the molten surface. Detectability of a collisional afterglow depends on properties of the planet's atmosphere -- primarily on the mass of the atmosphere. A planet with a thin atmosphere is more readily detected, because there is little atmosphere to obscure the hot surface. Paradoxically, a more massive atmosphere prevents one from easily seeing the hot surface, but also keeps the planet hot for a longer time. In terms of planetary mass, more massive planets are also easier to detect than smaller ones because of their larger emitting surface areas. We present preliminary calculations assuming a range of protoplanet masses (1-10 M_\earth), surface pressures (1-1000 bar), and atmospheric compositions, for molten planets with surface temperatures ranging from 1000 to 1800 K, in order to explore the diversity of emergent spectra that are detectable. While current 8- to 10-m class ground-based telescopes may detect hot protoplanets at wide orbital separations beyond 30 AU (if they exist), we will likely have to wait for next-generation extremely large telescopes or improved diffraction suppression techniques to find terrestrial planets in formation within several AU of their host stars.Comment: 28 pages, 6 figures, ApJ manuscript format, accepted into the Ap

Do non-steroidal anti-inflammatory drugs provide a protective effect on developing Barrett’s esophagus and esophageal cancer? A systematic review and meta-analysis

This is a protocol of a systematic review

Is the research you value a waste of money?

Introduction and Hypothesis: Eighty-five percent of health research may be wasted, resulting in $170 billion annually in wasteful research spending worldwide. Given the increased use of randomized trials and their influence on medicine, one method to combat research waste is to conduct RCTs only when a systematic review (SR) suggests more data are needed or when no previous systematic reviews are identified. Here, we hypothesize SRs would be rarely cited as justification for conducting RCTs.Methods: We analysed RCTs published between 2016 and 2018 in New England Journal of Medicine, Lancet, and Journal of the American Medical Association. We performed duplicate and independent data extraction to ensure the accuracy and validity of our data. For each trial, we extracted whether SRs were cited as justification for conducting the clinical trial.Results: Our search retrieved 665 records, of which 628 were included. Overall, 706 SR's were cited in these 628 RCTs; of which, 318 were referenced in the introduction, 82 in the methods, and 306 in the discussion. 49 SRs were cited verbatim as justification for conducting the trial. RCTs published in Lancet were more likely to cite a SR as justification for conducting the trial.Conclusion: Very few clinical trials cite systematic reviews as the basis for undertaking the trial. We believe trialists should be required to present relevant systematic reviews to an ethics or peer review committee demonstrating an unmet need prior to initiating a trial. Eliminating research waste is both a scientific and ethical responsibility

The chemistry of vibrationally excited H2 in the interstellar medium

The internal energy available in vibrationally excited H2 molecules can be used to overcome or diminish the activation barrier of various chemical reactions of interest for molecular astrophysics. In this article we investigate in detail the impact on the chemical composition of interstellar clouds of the reactions of vibrationally excited H2 with C+, He+, O, OH, and CN, based on the available chemical kinetics data. It is found that the reaction of H2 (v>0) and C+ has a profound impact on the abundances of some molecules, especially CH+, which is a direct product and is readily formed in astronomical regions with fractional abundances of vibrationally excited H2, relative to ground state H2, in excess of 10^(-6), independently of whether the gas is hot or not. The effects of these reactions on the chemical composition of the diffuse clouds zeta Oph and HD 34078, the dense PDR Orion Bar, the planetary nebula NGC 7027, and the circumstellar disk around the B9 star HD 176386 are investigated through PDR models. We find that formation of CH+ is especially favored in dense and highly FUV illuminated regions such as the Orion Bar and the planetary nebula NGC 7027, where column densities in excess of 10^(13) cm^(-2) are predicted. In diffuse clouds, however, this mechanism is found to be not efficient enough to form CH+ with a column density close to the values derived from astronomical observations.Comment: accepted for publication in the Astrophysical Journal; 9 pages, 7 figure

The Expansion of the Autonomy of Youth: Responses of the Secondary School to Problems of Order in the 1960s

This reports a study of the extent of violence and disorder, drug use, vandalism and theft, and racial conflicts in high schools, and of attempts at social control. The authors analyzed two national surveys of school principals supplemented with interviews in the local area. They concluded that while numerous problems exist, schools have dealt with them, not primarily by surveillance and punishment but rather by redefining students from “children of the school” to “citizens of the community,” thus externalizing many of the problems of disorder and control

Chemical pathways in ultracold reactions of SrF molecules

We present a theoretical investigation of the chemical reaction SrF + SrF $\rightarrow$ products, focusing on reactions at ultralow temperatures. We find that bond swapping, SrF + SrF $\rightarrow$ Sr$_2$ + F$_2$, is energetically forbidden at these temperatures. Rather, the only energetically allowed reaction is SrF + SrF $\rightarrow$ SrF$_2$ + Sr, and even then only singlet states of the SrF$_2$ trimer can form. A calculation along a reduced reaction path demonstrates that this abstraction reaction is barrierless, and proceeds by one SrF molecule "handing off" a fluorine atom to the other molecule.Comment: Two column format, 7 pages, 3 figures. Submitted to PR

Changing Groundwater Levels in the Sandstone Aquifers of Northern Illinois and Southern Wisconsin: Impacts on Available Water Supply

In 2014-15, the Illinois State Water Survey conducted their largest synoptic measurement of water levels (i.e., heads) in Cambrian-Ordovician sandstone wells since 1980. The study covered 33 counties in the northern half of Illinois where demands for water are satisfied, in part, by sandstone aquifers. The Wisconsin Geological and Natural History Survey also measured sandstone wells in 10 counties in southern Wisconsin. These observations were used to generate head contours of the sandstone aquifers. These contours provide insight into the direction and magnitude of groundwater flow. They also can be compared with historic measurements, providing insight into the impact of changing groundwater withdrawals through time. In predevelopment conditions, heads in the Cambrian-Ordovician sandstone aquifers were near or above land surface. Due to pumping from the sandstone aquifers, heads have decreased over time; this decrease is referred to as drawdown. In 2014, drawdown in northeastern Illinois was typically over 300 ft and exceeded 800 ft in the Joliet region. Three factors drove this large drawdown. First, demands for water from sandstone aquifers are much greater in northeastern Illinois than in the rest of the study region. Second, the sandstone aquifers are overlain by aquitards, which are low permeable materials that limit vertical infiltration of water. Third, the Sandwich Fault Zone limits water flowing into the sandstone aquifers of northeastern Illinois from the south. Heads near the center of the cone of depression continue to have a decreasing trend. The more severe drawdown in northeastern Illinois has resulted in local areas where heads have fallen below the top of the sandstone, known as desaturation. Desaturation of a sandstone aquifer can create a number of water quality and quantity concerns. The uppermost sandstone, the St. Peter, was observed to be partially desaturated in portions of Will, Kane, and Kendall Counties under non-pumping conditions. Other areas in these counties are at risk of desaturation under pumping conditions or with the installation of additional wells connecting the St. Peter to deeper, more heavily stressed sandstones. Simulations from a groundwater flow model indicate that the risk of desaturation will increase with increased future withdrawals. Despite the relatively small demand for water throughout much of central Illinois, heads have been declining since predevelopment, likely due to the shale overlying the sandstone. This shale serves as an aquitard, minimizing vertical infiltration of groundwater to the sandstone. Sustained drawdown in this region could potentially induce flow from the southern half of the state, where water in the sandstone is highly saline and not suitable as a drinking water supply. Drawdown in northwestern Illinois was also typically small (<100 ft), primarily due to two factors: 1) low demands from the sandstone aquifers and 2) the absence of shale aquitards. The notable exception is in Winnebago County, near Rockford, where demands are historically high and drawdown was on the order of 100-200 ft. While the quantity of water in the aquifer is not a concern in this region, large withdrawals could result in reductions of natural groundwater discharge to surface waters, impacting stream ecosystems under low flow conditions. Drawdown since predevelopment was over 300 ft in southeastern Wisconsin, with the greatest drawdown in Waukesha County of over 400 ft. Recent trends indicate heads in the Waukesha area are recovering, although they are still well below predevelopment levels. [This report is also associated with the fact sheets: Changing Groundwater Levels in the Cambrian-Ordovician Sandstone Aquifers of Northern Illinois, 1980-2014, Groundwater Availability in Northeastern Illinois from Deep Sandstone Aquifers, and Sources of Water for Communities in Northeastern Illinois.published or submitted for publicationis peer reviewedOpe

Spacesuit Range of Motion Investigations Using Video and Motion Capture Systems at Spaceflight Analogue Expeditions and within the ERAU S.U.I.T. Lab

The Embry-Riddle Aeronautical University (ERAU) Spacesuit Utilization of Innovative Technology Laboratory (S.U.I.T. Lab) is dedicated to the pursuit of advancing human spaceflight by contributing to spacesuit and operations research with experiential programs for students. A significant portion of the S.U.I.T. Lab’s portfolio is dedicated to the design and execution of spacesuit range of motion (ROM) investigations using video and motion capture systems. ROM biomechanical angles were measured using these techniques in conjunction with developing protocols for both simulated extravehicular activity suits at spaceflight analogue expeditions, and on ERAU campus with Final Frontier Design (FFD) intravehicular activity pressure suits. Designing protocols ensures effective communication for the analysis of simulated spacesuit performance to a remote crew. With communication delays to Earth, a self-sufficient spacesuit diagnosis is required to provide future astronauts with immediate action to take when dealing with a malfunctioning spacesuit. The video capture methodology is designed so that any crew would be able to conduct recordings with minimal impact to their schedule and with camera resources that are standard equipment. Spaceflight mission analogues involved in this study include: Hawai\u27i Space Exploration Analog and Simulation (HI-SEAS Mission V, 2017); Mars Desert Research Station (MDRS Crew 188, 2018), and AMADEE-18 in Oman (2018). Video capture can be used to collaborate with several spacesuit manufacturers to offer a snapshot comparison between designs, validate and verify capabilities, and aid with the selection of the right suit for the right job. The analogue locations recorded unsuited and suited data, while the November FFD test focused on motion capture (with video capture taken for validation) of unsuited, suited unpressurized, and suited while pressurized to 3.5 psid conditions. Early results from the motion capture align with values estimated from video capture and future work will compare the accuracy of these techniques

A world population growth model: Interaction with Earth's carrying capacity and technology in limited space

Up to 1900, world population growth over 1500 years fitted the quasi-hyperbolic format P(t) = a/(D-t)M, but this fit projected to infinite population around 2000. The recent slowdown has been fitted only by iteration of differential equations. This study fits the mean world population estimates from CE 400 to present with "tamed quasi-hyperbolic function" P(t) = A/[ln(B + e(D-t)//τ)]M, which reverts to P = a/(D-t)M when t ≤D. With coefficient values P(t) = 3.83 × 109/[ln(1.28 + e(1980-t)/22.9)]0.70, the fit is within ±9%, except in 1200-1400, and projects to a plateau at 10.2 billion. An interaction model of Earth's carrying capacity and technological-organizational skills is proposed. It can be approximately fitted with this P(t) and an analogous equation for carrying capacity. © 2013 Elsevier Inc

Using genomic repeats for phylogenomics: A case study in wild tomatoes (Solanum section Lycopersicon: Solanaceae)

High-throughput sequencing data have transformed molecular phylogenetics and a plethora of phylogenomic approaches are now readily available. Shotgun sequencing at low genome coverage is a common approach for isolating high-copy DNA, such as the plastid or mitochondrial genomes, and ribosomal DNA. These sequence data, however, are also rich in repetitive elements that are often discarded. Such data include a variety of repeats present throughout the nuclear genome in high copy number. It has recently been shown that the abundance of repetitive elements has phylogenetic signal and can be used as a continuous character to infer tree topologies. In the present study, we evaluate repetitive DNA data in tomatoes (Solanum section Lycopersicon) to explore how they perform at the inter- and intraspecific levels, utilizing the available data from the 100 Tomato Genome Sequencing Consortium. The results add to previous examples from angiosperms where genomic repeats have been used to resolve phylogenetic relationships at varying taxonomic levels. Future prospects now include the use of genomic repeats for population-level analyses and phylogeography, as well as potentially for DNA barcoding