Nutrient export from a proximal intermittent stream draining EKU Meadowbrook Farm, Madison County, Kentucky

Agricultural activities contribute significant amounts of nutrients that contaminate surface and subsurface water. Eastern Kentucky University (EKU) Meadowbrook Farm (Madison County, Kentucky) seeks to decrease its export of nutrients to Muddy Creek using sequestration techniques. The first step in the overall process is to determine nutrient export at present, before sequestration efforts take place. Here we estimate the export of phosphate, nitrate, and ammonium during Tropical Storm Cindy (July 22 to 24, 2017) from a proximal, intermittent stream, named the BRC. This stream drains a representative portion the Farm, receiving water from a dairy complex, pasture, and cropland. To estimate nutrient export, both discharge and nutrient concentration must be determined. We have built a V-notched weir across the BRC drainage equipped with a datalogger that measures water elevation behind the dam, and an autosampler that captures water samples during rain events. Water level and discharge over the dam are proportional, so that discharge can be calculated during rain events. Nutrient concentration is measured for each water sample using accepted colorimetric methods: ascorbic acid (phosphate), cadmium reduction (nitrate), and sodium hypochlorite (ammonium). Once discharge and nutrient concentrations are measured for the rain event, total nutrient mass can be calculated from the resultant curves (Fig. 1). Discharge and concentration data were parsed into 30-second time steps over the course of the entire, 72-hour rain event, and we used a cubic spline application (grafted into MS Excel) to produce a continuous function for each parameter. The area under the discharge and concentration curves yielded total solute mass for the Cindy event. Based on these data and using the cubic spline technique, we estimate that the export of phosphorus was 3.1 kg P occurring as dissolved orthophosphate, and 6.3 kg N occurring as dissolved nitrate (5.3 kg) and ammonium (1.0 kg) during Cindy. We also intend to determine the amount of total phosphorus (orthophosphate, other forms of dissolved phosphorus, P contained within dissolved organics, and P adsorbed onto fine particulates) exported during Cindy, as well as estimating nutrient export for five other rain events captured during 2017

Patterns of nutrient export for a typical non-point source, Meadowbrook Farm, Madison County, Kentucky

Excess nutrients are found in watersheds originating from active farmland often causing poor water quality and eutrophication in natural waters. Use of fertilizer and animal husbandry can contaminate both surface water and groundwater. Eastern Kentucky University’s Meadowbrook Farm raises crops and livestock and is typical of farms that contribute excess nutrient contaminants to watersheds as non-point sources. An instrumented weir is positioned within a key sub-watershed of the Farm that empties into Muddy Creek, a tributary of the Kentucky River. This drainage is the largest outlet from the Farm that is representative of the Farm’s collective activities. We measured flow and nutrient concentration (orthophosphate, PO43-; nitrate, NO3-; and ammonium, NH4+) over the weir to ascertain flow rates, nutrient export rates, and overall nutrient export. We concentrate on patterns of nutrient export during a single rainy period from 22 to 25 June 2017, which encompasses the passage of the remnants of tropical storm Cindy. In addition, baseline samples were obtained during drier periods throughout that summer. Various nutrients respond differently to storm flow. Dissolved phosphate mirrors the flow hydrograph showing peak concentrations of 0.5, 0.8, 1.2, and 1.0 mg/L correlative with 4 distinct instances of peak flow. Nitrate concentration spikes sharply to ~3.0 mg/L during initial runoff but then quickly decreases and maintains constant values between 1.0 and 1.5 mg/L. Ammonium values are highest, just under 2 mg/L, before initial flow over the weir and then decrease to show sporadic values between 0.1 and 0.6 mg/L, apparently independent of discharge

Nutrient contamination from an agricultural non-point source and its mitigation: A case study of EKU Meadowbrook Farm, Madison County, Kentucky

Non-point sources are now responsible for most nutrient contamination in surface water and groundwater, leading to eutrophication and decreased water quality. Because of fertilizer use and animal husbandry, agricultural areas are prime sources for nutrient contamination. Consequently, it is advisable to mitigate entry of nutrients into watersheds from agricultural runoff and groundwater flow. Eastern Kentucky University (EKU) Meadowbrook Farm (Madison County, Kentucky) seeks to decrease its export of nutrients to Muddy Creek, which is tributary of the Kentucky River. To demonstrate the efficacy of any sequestration strategies, nutrient export must be measured both before and after sequestration efforts are implemented. Over the past two field seasons, we have investigated the sources and behavior of dissolved nutrients (phosphate, PO43-; ammonium, NH4+; nitrate, NO3-) and other dissolved ions, and their transport via hydrologic pathways at the Farm. Here, we present our findings in three parts: (1) background nutrient concentration in surface water and groundwater during fair-weather times and identification of likely nutrient sources (Borowski et al.); (2) details of cation and nutrient drainage from the Farm during rain events (Buskirk et al.); and (3) quantification of nutrient export from a representative sub-watershed on the Farm during a major rainfall event (Winter et al.). Meadowbrook Farm is a working farm raising crops (mainly corn and soybeans), and rearing dairy and beef cattle and other livestock. Livestock produce manure that is eventually applied to pasture and croplands; supplemental fertilizer is also used. These are the primary sources for excess nutrients that leave the Farm via overland and groundwater flow. We sampled water from several different water sources and measured their nutrient content. Water types include that from drainage tiles, springs (groundwater), and surface water within intermittent streams on the Farm, other adjacent streams, and Muddy Creek. Water samples were passed through a 0.4 mm syringe filter and then preserved at a pH of 2 with sulfuric acid (H2SO4). Nutrient concentration, expressed in terms of phosphorus (P) and nitrogen (N) content, was measured colorimetrically using an UV-VIS spectrophotometer and the ascorbic acid (orthophosphate; P-PO43-), sodium hypochlorite (ammonium, N-NH4+), and cadmium reduction (nitrate, N-NO3-) methods. Nitrate is the nutrient contaminant with highest median concentration (~1.1 mg/L N-NO3) in surface waters; median concentration for ammonium and phosphate are ~0.3 mg/L N-NH4+ and ~0.03 mg/L P-PO43-, respectively. Relative to national data, Farm groundwater is enriched in all nutrients with median concentrations of ~0.04 mg/L N-NH4+, ~7.3 mg/L N-NO3, and ~0.04 mg/L P-PO43-. Enrichment in ammonium is more significant compared to that of nitrate and phosphate. These data provide fair-weather, background estimates for comparison to nutrient export that occur during rain events

Decision to Use an Airframe Parachute in a Flight Training Environment

The purpose of this study was to complete a qualitative analysis of the decision-making process used by pilots to determine whether or not to deploy an airframe parachute system. A sample of participants from the subject university’s flight training program was selected to complete a scripted simulator flight in instrument flight conditions. During the flight, participants experienced an engine failure while enroute during IFR conditions. The script was examined and validated by an expert panel who determined use of the airframe parachute was the most appropriate outcome for the scenario. Interestingly, only 9 of the 21 participants responded as expected by the expert panel and deployed the parachute system; only three of the nine followed the correct deployment procedure as outlined in the Pilot’s Operating Handbook. Analysis of a post-flight survey completed by participants provides insights into the decision-making process used by pilots and offers explanations on why or why not participants used the airframe parachute

Control of interjoint coordination during the swing phase of normal gait at different speeds

BACKGROUND: It has been suggested that the control of unconstrained movements is simplified via the imposition of a kinetic constraint that produces dynamic torques at each moving joint such that they are a linear function of a single motor command. The linear relationship between dynamic torques at each joint has been demonstrated for multijoint upper limb movements. The purpose of the current study was to test the applicability of such a control scheme to the unconstrained portion of the gait cycle – the swing phase. METHODS: Twenty-eight neurologically normal individuals walked along a track at three different speeds. Angular displacements and dynamic torques produced at each of the three lower limb joints (hip, knee and ankle) were calculated from segmental position data recorded during each trial. We employed principal component (PC) analysis to determine (1) the similarity of kinematic and kinetic time series at the ankle, knee and hip during the swing phase of gait, and (2) the effect of walking speed on the range of joint displacement and torque. RESULTS: The angular displacements of the three joints were accounted for by two PCs during the swing phase (Variance accounted for – PC1: 75.1 ± 1.4%, PC2: 23.2 ± 1.3%), whereas the dynamic joint torques were described by a single PC (Variance accounted for – PC1: 93.8 ± 0.9%). Increases in walking speed were associated with increases in the range of motion and magnitude of torque at each joint although the ratio describing the relative magnitude of torque at each joint remained constant. CONCLUSION: Our results support the idea that the control of leg swing during gait is simplified in two ways: (1) the pattern of dynamic torque at each lower limb joint is produced by appropriately scaling a single motor command and (2) the magnitude of dynamic torque at all three joints can be specified with knowledge of the magnitude of torque at a single joint. Walking speed could therefore be altered by modifying a single value related to the magnitude of torque at one joint

Structural basis for the RING catalyzed synthesis of K63 linked ubiquitin chains

This work was supported by grants from Cancer Research UK (C434/A13067), the Wellcome Trust (098391/Z/12/Z) and Biotechnology and Biological Sciences Research Council (BB/J016004/1).The RING E3 ligase catalysed formation of lysine 63 linked ubiquitin chains by the Ube2V2–Ubc13 E2 complex is required for many important biological processes. Here we report the structure of the RING domain dimer of rat RNF4 in complex with a human Ubc13~Ub conjugate and Ube2V2. The structure has captured Ube2V2 bound to the acceptor (priming) ubiquitin with Lys63 in a position that could lead to attack on the linkage between the donor (second) ubiquitin and Ubc13 that is held in the active “folded back” conformation by the RING domain of RNF4. The interfaces identified in the structure were verified by in vitro ubiquitination assays of site directed mutants. This represents the first view of the synthesis of Lys63 linked ubiquitin chains in which both substrate ubiquitin and ubiquitin-loaded E2 are juxtaposed to allow E3 ligase mediated catalysis.PostprintPeer reviewe

Transcription control by the ENL YEATS domain in acute leukaemia

Recurrent chromosomal translocations producing a chimaeric MLL oncogene give rise to a highly aggressive acute leukaemia associated with poor clinical outcome. The preferential involvement of chromatin-associated factors as MLL fusion partners belies a dependency on transcription control. Despite recent progress made in targeting chromatin regulators in cancer, available therapies for this well-characterized disease remain inadequate, prompting the need to identify new targets for therapeutic intervention. Here, using unbiased CRISPR-Cas9 technology to perform a genome-scale loss-of-function screen in an MLL-AF4-positive acute leukaemia cell line, we identify ENL as an unrecognized gene that is specifically required for proliferation in vitro and in vivo. To explain the mechanistic role of ENL in leukaemia pathogenesis and dynamic transcription control, a chemical genetic strategy was developed to achieve targeted protein degradation. Acute loss of ENL suppressed the initiation and elongation of RNA polymerase II at active genes genome-wide, with pronounced effects at genes featuring a disproportionate ENL load. Notably, an intact YEATS chromatin-reader domain was essential for ENL-dependent leukaemic growth. Overall, these findings identify a dependency factor in acute leukaemia and suggest a mechanistic rationale for disrupting the YEATS domain in disease.K. LubinE. Wood

Amino acid-mediated impacts of elevated carbon dioxide and simulated root herbivory on aphids are neutralized by increased air temperatures

Changes in host plant quality, including foliar amino acid concentrations, resulting from global climate change and attack from multiple herbivores, have the potential to modify the pest status of insect herbivores. This study investigated how mechanically simulated root herbivory of lucerne (Medicago sativa) before and after aphid infestation affected the pea aphid (Acyrthosiphon pisum) under elevated temperature (eT) and carbon dioxide concentrations (eCO2). eT increased plant height and biomass, and eCO2 decreased root C:N. Foliar amino acid concentrations and aphid numbers increased in response to eCO2, but only at ambient temperatures, demonstrating the ability of eT to negate the effects of eCO2. Root damage reduced aboveground biomass, height, and root %N, and increased root %C and C:N, most probably via decreased biological nitrogen fixation. Total foliar amino acid concentrations and aphid colonization success were higher in plants with roots cut early (before aphid arrival) than those with roots cut late (after aphid arrival); however, this effect was counteracted by eT. These results demonstrate the importance of amino acid concentrations for aphids and identify individual amino acids as being potential factors underpinning aphid responses to eT, eCO2, and root damage in lucerne. Incorporating trophic complexity and multiple climatic factors into plant–herbivore studies enables greater insight into how plants and insects will interact in the future, with implications for sustainable pest control and future crop security

P2Y12 platelet inhibition in clinical practice

Platelet adhesion, activation and aggregation play a pivotal role in atherothrombosis. Intracoronary atherothrombosis is the most common cause of the development of acute coronary syndrome (ACS), and plays a central role in complications occurring around percutaneous coronary intervention (PCI) including recurrent ACS, procedure-related myocardial infarction or stent thrombosis. Inhibition of platelet aggregation by medical treatment impairs formation and progression of thrombotic processes and is therefore of great importance in the prevention of complications after an ACS or around PCI. An essential part in the platelet activation process is the interaction of adenosine diphosphate (ADP) with the platelet P2Y12 receptor. The P2Y12 receptor is the predominant receptor involved in the ADP-stimulated activation of the glycoprotein IIb/IIIa receptor. Activation of the glycoprotein IIb/IIIa receptor results in enhanced platelet degranulation and thromboxane production, and prolonged platelet aggregation. The objectives of this review are to discuss the pharmacological limitations of the P2Y12 inhibitor clopidogrel, and describe the novel alternative P2Y12 inhibitors prasugrel and ticagrelor and the clinical implications of the introduction of these new medicines