RESUMEN
Surface water (SW) quality is particularly vulnerable to increased concentrations of nutrients, and this issue may be exacerbated by climate change. Knowledge of the effects of temperature and rainfall on SW quality is required to take the necessary measures to achieve good SW status in the future. To address this, the aims of this study were threefold: (1) to assess how a changing climate may alter the nitrate, ammonium, phosphorus and biological oxygen demand status (BOD5) of SW; (2) assess the relationship between water quality and flow; and (3) simulate diffuse and point source pollution reduction scenarios in the Júcar River Basin District in the Mediterranean region. A regionalised long-term climate scenario was used following one Representative Concentration Pathway (RCP8.5) with the data incorporated into the coupling of hydrological and water quality models. According to these climate change scenarios, SW with poor nitrate, ammonium, phosphorus and BOD5 status are expected to increase in the future by factors of 1.3, 1.9, 4 and 4, respectively. Furthermore, median ammonium and phosphorus concentration may be doubled in months with low flows. Additional measures are required to maintain current status in the water bodies, and it is necessary to reduce at least 25% of diffuse nitrate pollution, and 50% of point loads of ammonium, phosphorus, and BOD5.
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Compuestos de Amonio , Calidad del Agua , Ríos , Cambio Climático , Nitratos , Fósforo/análisisRESUMEN
The electrical response of plants to environmental stimuli can be measured and quantitatively related to the intensity of several stimulating sources, like temperature, solar radiation, soil water content, evapotranspiration rates, sap flow and dendrometric cycles. These relations can be used to assess the influence of different environmental situations on soil water availability to plants, defined as a steady state condition between leaf transpirative flow and soil water flow to plant roots. A restricted soil water flow due to soil dryness can trigger water stress in plants, if the atmospheric evaporative demand is high, causing partial stomata closure as a physiological response to avoid plant dehydration; water stressed and unstressed plants manifest a differential electrical response. Real time plant electrical response measurements can anticipate actions that prevent the plant reaching actual stress conditions, optimizing stomata gas exchange and photosynthetic rates. An electrophysiological sensor developed in this work, allows remote real-time recording information on plant electrical potential (EP) in the field, which is highly related to EP measurements obtained with a laboratory Keithley voltmeter sensor used in an highly controlled experimental setup. Our electrophysiological sensor is a wireless, autonomous devise, which transmits EP information via Internet to a data server. Using both types of sensors (EP electrodes with a Keithley voltmeter and the electrophysiological sensor), we measured in real time the electrical responses of Persea americana and Prunus domestica plants, to induced water deficits. The differential response for 2 scenarios: irrigation and water restriction is identified by a progressive change in slope on the daily maximal and minimal electric signal values in stressed plants, and a zero-slope for similar signals for well-watered plants. Results show a correspondence between measured signals obtained by our electrophysiological sensor and the EP electrodes connected to the Keithley voltmeter in each irrigation stage. Also, both sensors show a daily cyclical signal (circadian cycle).
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Riego Agrícola , Fenómenos Electrofisiológicos , Persea/fisiología , Prunus/fisiología , Madera/fisiología , Electrofisiología/instrumentaciónRESUMEN
BACKGROUND: A computerized physician order entry (CPOE) system provides opportunity for real-time alerts to prescribers. Winthrop University Hospital began using CPOE in 2009. OBJECTIVE: We sought to improve prescribing among older hospitalized patients by adding alerts to the CPOE system for potentially inappropriate medications. METHODS: In January 2011, informational alerts were integrated into the CPOE system for selected high-risk medications: diphenhydramine, metoclopramide, and all antipsychotics. We evaluated the effect of these alerts on prescribing frequency by comparing the number of prescriptions during the second quarters of 2010 ("pre-alert") with the second quarters of 2011 through 2013 ("post-alert"). Prescribing patterns were evaluated through a pharmacy database of medication orders. Frequency of prescribing was adjusted for total discharges. A comparison was made to ages 18-64 years, and comparing "as needed" vs standing orders. RESULTS: In the 65 years of age and older group, there were significant reductions in prescription rates pre-alert vs post-alert for diphenhydramine (p < 0.001) and metoclopramide (p < 0.001). There was no decrease in prescription rates for antipsychotics in older patients (p = 0.80). In the younger comparison group, no decreases in prescription rates for those drugs were observed. Our analysis is based on numbers of written prescriptions and not actual doses administered; therefore, no conclusions concerning the effect of these alerts on communication or documentation of risk/benefits of these medications can be ascertained. CONCLUSION: The data suggest that prescribing rates for drugs with the least efficacy and potential for harm and with alternative agents (i.e., diphenhydramine and metoclopramide) can be modified by CPOE alerts for older patients.
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Sistemas de Entrada de Órdenes Médicas , Pautas de la Práctica en Medicina/estadística & datos numéricos , Adolescente , Adulto , Factores de Edad , Anciano , Humanos , Persona de Mediana Edad , Adulto JovenRESUMEN
Development and evaluation of a real-time plant water stress sensor, based on the electrophysiological behavior of fruit-bearing woody plants is presented. Continuous electric potentials are measured in tree trunks for different irrigation schedules, inducing variable water stress conditions; results are discussed in relation to soil water content and micro-atmospheric evaporative demand, determined continuously by conventional sensors, correlating this information with tree electric potential measurements. Systematic and differentiable patterns of electric potentials for water-stressed and no-stressed trees in 2 fruit species are presented. Early detection and recovery dynamics of water stress conditions can also be monitored with these electrophysiology sensors, which enable continuous and non-destructive measurements for efficient irrigation scheduling throughout the year. The experiment is developed under controlled conditions, in Faraday cages located at a greenhouse area, both in Persea americana and Prunus domestica plants. Soil moisture evolution is controlled using capacitance sensors and solar radiation, temperature, relative humidity, wind intensity and direction are continuously registered with accurate weather sensors, in a micro-agrometeorological automatic station located at the experimental site. The electrophysiological sensor has two stainless steel electrodes (measuring/reference), inserted on the stem; a high precision Keithley 2701 digital multimeter is used to measure plant electrical signals; an algorithm written in MatLab(®), allows correlating the signal to environmental variables. An electric cyclic behavior is observed (circadian cycle) in the experimental plants. For non-irrigated plants, the electrical signal shows a time positive slope and then, a negative slope after restarting irrigation throughout a rather extended recovery process, before reaching a stable electrical signal with zero slope. Well-watered plants presented a continuous signal with daily maximum and a minimum EP of similar magnitude in time, with zero slope. This plant electrical behavior is proposed for the development of a sensor measuring real-time plant water status.
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Ritmo Circadiano/fisiología , Persea/fisiología , Prunus/fisiología , Transducción de Señal/fisiología , Agua/fisiología , Deshidratación , Fenómenos Electrofisiológicos , Ambiente , Luz , Persea/efectos de la radiación , Tallos de la Planta/fisiología , Tallos de la Planta/efectos de la radiación , Prunus/efectos de la radiación , Suelo , ÁrbolesRESUMEN
Increased whole blood viscosity (WBV) can be injurious to the vascular endothelium and increase the risk of atherothrombotic events. This study examined the effect of hemodialysis ultrafiltration (UF) on WBV, with a focus on high vs. low-volume UF patients. In stable hemodialysis patients, blood was drawn for hematocrit (Hct) and WBV at the start, midpoint, and at the end of dialysis. For analysis, patients were divided into high UF (≥2700 mL) or low UF (<2700 mL) groups. A total of 59 patients completed the study. Mean Hct increased during dialysis in both groups. The intradialytic increase in Hct was significantly greater in the high vs. the low UF group (3.2% vs. 1.28%, P = 0.01), with a significantly higher end-dialysis Hct in the high UF group (40.5% vs. 38%, P = 0.02). At the end of dialysis, both high shear rate WBV (P < 0.01) and low shear rate WBV (P < 0.01) were significantly higher in the high UF compared with the low UF group. There was an approximately two-fold greater increase in high shear rate (P < 0.01) and low shear rate (P = 0.01) WBV during dialysis in high vs. low UF groups. The increase in high shear rate WBV during dialysis was significantly correlated with an increase in Hct (R(2) = 0.63, P < 0.01). We found that hemodialysis UF causes a surge in WBV. The surge was of greater magnitude in high than in low UF patients.