50 research outputs found

    Use of Vegetation Monitoring and Professional Sharpshooting in White-Tailed Deer (Odocoileus virginianus) Management at Eagle Creek Park in Indianapolis

    Get PDF
    High white-tailed deer abundance at Eagle Creek Park (ECP) in Indianapolis necessitated active management to improve park habitat conditions. Significant deer impacts on local natural areas were first noted in the late 1990’s. Multiple years of deer browse monitoring, beginning in 2003, documented greatly impacted vegetation with heavy to severe browse damage in the park. After an initial managed hunt in 2014, population reductions have been accomplished exclusively at night by professional sharpshooters. Positive results are being evidenced through increasing pounds of venison per deer harvested and significant recovery of impacted vegetation communities

    TOI-561 b: A Low Density Ultra-Short Period "Rocky" Planet around a Metal-Poor Star

    Full text link
    TOI-561 is a galactic thick disk star hosting an ultra-short period (0.45 day orbit) planet with a radius of 1.37 R⊕_{\oplus}, making it one of the most metal-poor ([Fe/H] = -0.41) and oldest (∌\sim10 Gyr) sites where an Earth-sized planet has been found. We present new simultaneous radial velocity measurements (RVs) from Gemini-N/MAROON-X and Keck/HIRES, which we combined with literature RVs to derive a mass of Mb_{b}=2.24 ±\pm 0.20 M⊕_{\oplus}. We also used two new Sectors of TESS photometry to improve the radius determination, finding Rb_{b}=1.37±0.04R⊕1.37 \pm 0.04 R_\oplus, and confirming that TOI-561 b is one of the lowest-density super-Earths measured to date (ρb\rho_b= 4.8 ±\pm 0.5 g/cm3^{3}). This density is consistent with an iron-poor rocky composition reflective of the host star's iron and rock-building element abundances; however, it is also consistent with a low-density planet with a volatile envelope. The equilibrium temperature of the planet (∌\sim2300 K) suggests that this envelope would likely be composed of high mean molecular weight species, such as water vapor, carbon dioxide, or silicate vapor, and is likely not primordial. We also demonstrate that the composition determination is sensitive to the choice of stellar parameters, and that further measurements are needed to determine if TOI-561 b is a bare rocky planet, a rocky planet with an optically thin atmosphere, or a rare example of a non-primordial envelope on a planet with a radius smaller than 1.5 R⊕_{\oplus}.Comment: Accepted to AJ on 11/28/202

    Constraints on the shallow elastic and anelastic structure of Mars from InSight seismic data

    Get PDF
    Mars’s seismic activity and noise have been monitored since January 2019 by the seismometer of the InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) lander. At night, Mars is extremely quiet; seismic noise is about 500 times lower than Earth’s microseismic noise at periods between 4 s and 30 s. The recorded seismic noise increases during the day due to ground deformations induced by convective atmospheric vortices and ground-transferred wind-generated lander noise. Here we constrain properties of the crust beneath InSight, using signals from atmospheric vortices and from the hammering of InSight’s Heat Flow and Physical Properties (HP3) instrument, as well as the three largest Marsquakes detected as of September 2019. From receiver function analysis, we infer that the uppermost 8–11 km of the crust is highly altered and/ or fractured. We measure the crustal diffusivity and intrinsic attenuation using multiscattering analysis and find that seismic attenuation is about three times larger than on the Moon, which suggests that the crust contains small amounts of volatiles

    Escape from a metastable state

    Full text link

    Exploring, exploiting and evolving diversity of aquatic ecosystem models: a community perspective

    Get PDF

    Remote Data Collection of NOx Emissions from Surface Mine Coal Blasts Using UAV and Evaluation of Effects on Human Health and the Environment

    No full text
    One of the most common emissions from detonating explosives are nitrogen oxides (NOx), which are potentially deadly if inhaled. Lab studies estimate emission quantities, though great variation is shown based on site-specific conditions, and lab tests may not fully represent field results. Field values have not been measured due to the vast area affected. OSMRE recently promised to release a ruling regarding surface mine NOx production. Once the ruling is implemented, it may eventually be necessary to monitor site-specific NOx production from blasting. A small unmanned aerial vehicle system (sUAS) is able to carry a NOx gas monitor, rapidly travel to the blast location, and to follow resulting clouds of dust and emission gasses. This project will perform laboratory tests to expand on current estimations, determine an optimal method for collecting data, and evaluate the ability for this unique application of sUAS to assist in health risk assessment for mine employees and nearby communities. Additionally, large initial NOx concentrations do not necessarily correlate to unsafe conditions, and this project will be groundbreaking in observance of surface blasting emission dispersion. The project is still in early phases at the time of submission for this paper (Nov 1, 2017). Therefore, this paper focuses primarily on summarizing background research related to the project and a description of the project plan

    Effects of Downwash from a 6-Rotor Unmanned Aerial Vehicle (UAV) on Gas Monitor Concentrations

    No full text
    Unmanned aerial vehicles (UAVs) are being explored by researchers to measure concentrations of gas emissions in situations where such measurements are otherwise extremely difficult to obtain, such as NO and NO2 (NOx) emissions from surface mine blasting. Recently, countries have imposed or are planning to impose surface blasting gas pollution regulations, which creates a need for an improved understanding of UAV-based gas measuring systems. The experiments detailed in this paper were performed to determine if airflow generated by the rotors, also known as downwash, unnaturally alters concentration measurements. Downwash turbulence could create locations of varying pressure, which could affect concentration. A UAV fitted with gas sensors was attached to a stand in a controlled environment containing a mixture of NOx. The gas sensor measuring points were placed at various distances on and from the UAV body to evaluate downwash effects on gas concentration. Results show that the presence of downwash turbulence causes no statistically significant changes to concentration measurements at any distance or direction from the UAV. Based on these results, it is possible to use a UAV-mounted gas monitor to measure concentrations without concern for downwash interference, provided the UAV and measuring point are entirely contained within the gas cloud

    Post-Movement Stabilization Time for the Downwash Region of a 6-Rotor UAV for Remote Gas Monitoring

    No full text
    Unmanned aerial vehicles (UAV) have been used to monitor gas emissions for research projects, though downwash, the airflow produced by the UAV rotors, is potentially capable of artificially altering gas concentration measurements. Anemometers, placed at ten different distances below a 6-rotor UAV, measured air speeds in the downwash region. The collected data was used in combination with UAV rotor speed data to determine the stabilization time of the downwash region after the UAV has returned to a stable hovering position. The stabilization time will determine the amount of time after UAV movement until reliable concentration readings can be obtained within the downwash region. This paper presents stabilization times after vertical upward and rotational UAV movement

    Two-Component System Cross-Regulation Integrates <i>Bacillus anthracis</i> Response to Heme and Cell Envelope Stress

    No full text
    <div><p>Two-component signaling systems (TCSs) are one of the mechanisms that bacteria employ to sense and adapt to changes in the environment. A prototypical TCS functions as a phosphorelay from a membrane-bound sensor histidine kinase (HK) to a cytoplasmic response regulator (RR) that controls target gene expression. Despite significant homology in the signaling domains of HKs and RRs, TCSs are thought to typically function as linear systems with little to no cross-talk between non-cognate HK-RR pairs. Here we have identified several cell envelope acting compounds that stimulate a previously uncharacterized <i>Bacillus anthracis</i> TCS. Furthermore, this TCS cross-signals with the heme sensing TCS HssRS; therefore, we have named it <i><u>H</u></i>ssRS <i><u>i</u></i>nterfacing <i><u>T</u></i>CS (HitRS). HssRS reciprocates cross-talk to HitRS, suggesting a link between heme toxicity and cell envelope stress. The signaling between HssRS and HitRS occurs in the parental <i>B. anthracis</i> strain; therefore, we classify HssRS-HitRS interactions as cross-regulation. Cross-talk between HssRS and HitRS occurs at both HK-RR and post-RR signaling junctions. Finally, HitRS also regulates a previously unstudied ABC transporter implicating this transporter in the response to cell envelope stress. This chemical biology approach to probing TCS signaling provides a new model for understanding how bacterial signaling networks are integrated to enable adaptation to complex environments such as those encountered during colonization of the vertebrate host.</p></div
    corecore