TreeWatch.net : a water and carbon monitoring and modeling network to assess instant tree hydraulics and carbon status

TreeWatch.net is an initiative that has been developed to watch trees grow and function in real-time. It is a water- and carbon-monitoring and modeling network, in which high quality measurements of sap flow and stem diameter variation are collected on individual trees. Automated data processing using a cloud service enables instant visualization of water movement and radial stem growth. This can be used to demonstrate the sensitivity of trees to changing weather conditions, such as drought, heat waves, or heavy rain showers. But TreeWatch.net's true innovation lies in its use of these high precision harmonized data to also parameterize process-based tree models in real-time, which makes displaying the much needed mechanisms underlying tree responses to climate change possible. Continuous simulation of turgor to describe growth processes and long-term time series of hydraulic resistance to assess drought-vulnerability in real-time are only a few of the opportunities our approach offers. TreeWatch.net has been developed with the view to be complementary to existing forest monitoring networks and with the aim to contribute to existing dynamic global vegetation models. It provides high-quality data and real-time simulations in order to advance research on the impact of climate change on the biological response of trees and forests. Besides its application in natural forests to answer climate-change related scientific and political questions, we also envision a broader societal application of TreeWatch.net by selecting trees in nature reserves, public areas, cities, university areas, schoolyards, and parks to teach youngsters and create public awareness on the effects of changing weather conditions on trees and forests in this era of climate change

Simulation of long-term stem diameter variation of Ficus benjamina based on simulated transpiration

Greenhouse microclimate (light, temperature, relative humidity and CO2) and irrigation are important factors for plant growth, development and quality in ornamental horticulture. To optimize plant growth, actual stem diameter growth can be measured and compared with a desired growth pattern. Using the deviation between measured and simulated stem diameter growth, growers can decide whether and in which way the microclimate or irrigation needs to be adjusted. Together with this decision, costs associated with climate control and irrigation must also be taken into account. This will help growers to find a proper balance between cultivation costs and plant growth. In this study, Ficus benjamina was grown from cutting to mature plant in a controlled greenhouse environment. Growing conditions, microclimate as well as plant spacing, closely resembled the ones used in commercial greenhouses. Microclimate, soil water content, leaf temperature, sap flow, stem diameter variation and leaf thickness were continuously measured on three plants. In addition, discrete measurements of leaf area, projected crown surface area, stem water potential, photosynthesis, transpiration and stomatal conductance were performed. These measurements were used to further extend a mechanistic plant model, which allows simulation of long-term stem diameter variation

Use of leaf thickness sensors in horticultural crops

Changes in leaf thickness can be a rapid indicator of the plant’s water status and can therefore serve as an alarm signal for potential water deficits. Combining the use of continuous leaf thickness measurements with a mechanistic plant model describing optimal leaf growth and diel variations, would allow growers to optimize greenhouse growing conditions by adaptation of the microclimate and applied irrigation. Recent development of new sensors offers the possibility for real time measurements of leaf thickness on small plants, including ornamentals. However, the accuracy of leaf thickness variation measurements needs to be assured. In this study, the temperature influence on 12 LeafSen (Netafim, Tel Aviv, Israel) sensors has been tested in a temperature range from 16 °C to 31 °C by installation of the sensors on aluminium plates. Temperature variations in the investigated range resulted in sensor signal differences of up to 48 μm, indicating that temperature response can exceed the expected diel leaf thickness variation. Two typical temperature responses were distinguished, pointing to the need for a sensor specific temperature correction. The practical use of leaf thickness sensors and the established temperature corrections has been demonstrated by installing the sensors on the stem and leaf of three Ficus plants (Ficus benjamina) and three pot roses (Rosa chinensis cv.) starting from cutting stage in a commercial greenhouse environment

Titration procedures for nasal CPAP: Automatic CPAP or prediction formula?

Background: The best method for titration Of continuous positive airway pressure (CPAP) therapy in obstructive sleep apnea (OSA) syndrome has not yet been established. The 90th or 95th percentiles of the pressure titrated over time by automatic CPAP (A-CPAP) have been recommended as reference for prescribing therapeutic fixed CPAP (F-CPAP). We compared A-CPAP to F-CPAP. which was determined by a common prediction formula. Methods: Forty-five patients who were habituated to F-CPAP underwent titration polysomnography. In a double-blind randomized order, each patient used an A-CPAP device in the autotitration and in the fixed pressure mode during one half of the night. Apnea-hypopnea index (AHI) and pressure profiles were primary outcomes. Bias and precision were additionally assessed for both CPAP modes. Results: No significant differences in various sleep parameters or in subjective sleep quality evaluation were found. The AHI was effectively lowered in both CPAP modes (A-CPAP 7.7 [10.8] events/h versus F-CPAP 5.4 (9.0] events/h, p = 0.061). Comparison of group means showed that F-CPAP closely paralleled mean (Pmean) and median (P50). but not the 95th percentile (P95) pressure. of A-CPAP. While bias was lowest for Pmean and P50. there was a lack of precision in all A-CPAP pressure categories. Conclusions: We confirm that F-CPAP set by prediction formula is not worse in terms of AHI control than A-CPAP. On average. F-CPAP parallels Pmean and P50 but not P95. However. due to imprecise matching. individual F-CPAP values cannot be derived front Pmean or P50

A novel hybrid 3D endoscope zooming and repositioning system : design and feasibility study

Background: Manipulation of the endoscope during minimally invasive surgery is a major source of inconvenience and discomfort. This report elucidates the architecture of a novel one-hand controlled endoscope positioning device and presents a practicability evaluation. Methods and materials: Setup time and total surgery time, number and duration of the manipulations, side effects of three-dimensional (3D) imaging, and ergonomic complaints were assessed by three surgeons during cadaveric and in vivo porcine trials. Results: Setup was accomplished in an average (SD) of 230 (120) seconds. The manipulation time was 3.87 (1.77) seconds for angular movements and 0.83 (0.24) seconds for zooming, with an average (SD) of 30.5 (16.3) manipulations per procedure. No side effects of 3D imaging or ergonomic complaints were reported. Conclusions: The integration of an active zoom into a passive endoscope holder delivers a convenient synergy between a human and a machine-controlled holding device. It is shown to be safe, simple, and intuitive to use and allows unrestrained autonomic control of the endoscope by the surgeon

Lifestyle behaviour and risk factor control in coronary patients : Belgian results from the cross-sectional EUROASPIRE surveys

Objective: The aim of this study was to assess lifestyle behaviour as well as risk factor management across Belgian coronary patients who participated in the cross-sectional European Action on Secondary Prevention through Intervention to Reduce Events (EUROASPIRE) surveys. Methods: Analyses are based on a series of coronary patients by combining data from the Belgian participants in the EUROASPIRE III (328 patients; in 2006-2007) and EUROASPIRE IV (343 patients; in 2012-2013) surveys. Four hospitals located in the Ghent area participated in the surveys. Patients included in the analyses were >= 18 years old and had been hospitalised for a coronary event. Information on cardiovascular risk factors, lifestyle behaviour and medical treatment were obtained. Results: Overall, the proportion of smokers was 11% with 40% persistent smokers. Adequate physical activity levels were reported by 17%, 28% of patients were obese, 47% was central obese and known diabetes was prevalent in 21% of patients. Hypertension was observed in 46% of patients and 20% had a total cholesterol >= 5 mmol/L. About 80% had participated in a cardiac rehabilitation programme and the majority of patients were treated with blood pressure (92%) or lipid-lowering drugs (92%). Anxiety and depressive symptoms were reported by 30% and 24%, respectively. Differences between EUROASPIRE III and IV were limited. Conclusions: Compared to the overall EUROASPIRE results in Europe, Belgian CHD patients seem to do slightly better. However, tackling obesity, physical inactivity, hypertension and psychosocial distress remains an important challenge in the management of coronary patients