Academic literature on the topic 'Leaf level measurements'

Successful measurements of chlorophyll fluorescence (ChlF) spectral properties (typically in the wavelength range of 650–850 nm) across plant species, environmental conditions, and stress levels are a first step towards establishing a quantitative link between solar-induced chlorophyll fluorescence (SIF), which can only be measured at discrete ChlF spectral bands, and photosynthetic functionality. Despite its importance and significance, the various methodologies for the estimation of leaf-level ChlF spectral properties have not yet been compared, especially when applied to leaves with complex morphology, such as needles. Here we present, to the best of our knowledge, a first comparison of protocols for measuring leaf-level ChlF spectra: a custom-made system designed to measure ChlF spectra at ambient and 77 K temperatures (optical chamber, OC), the widely used FluoWat leaf clip (FW), and an integrating sphere setup (IS). We test the three methods under low-light conditions, across two broadleaf species and one needle-like species. For the conifer, we characterize the effect of needle arrangements: one needle, three needles, and needle mats with as little gap fraction as technically possible. We also introduce a simple baseline correction method to account for non-fluorescence-related contributions to spectral measurements. Baseline correction was found especially useful in recovering the spectra nearby the filter cut-off. Results show that the shape of the leaf-level ChlF spectra remained largely unaffected by the measurement methodology and geometry in OC and FW methods. Substantially smaller red/far-red ratios were observed in the IS method. The comparison of needle arrangements indicated that needle mats could be a practical solution to investigate temporal changes in ChlF spectra of needle-like leaves as they produced more reproducible results and higher signals.

The determination of plant nitrogen (N) content (%) in wheat via destructive lab analysis is expensive and inadequate for precision farming applications. Vegetation indices (VI) based on spectral reflectance can be used to predict plant N content indirectly. For these VI, reflectance from space-borne, airborne, or ground-borne sensors is captured. Measurements are often taken at the canopy level for practical reasons. Hence, translocation processes of nutrients that take place within the plant might be ignored or measurements might be less accurate if nutrient deficiency symptoms occur on the older leaves. This study investigated the impact of leaf number and measurement position on the leaf itself on the determination of plant N content (%) via reflectance measurements. Two hydroponic experiments were carried out. In the first experiment, the N fertilizer amount and growth stage for the determination of N content was varied, while the second experiment focused on a secondary induction of N deficiency due to drought stress. For each plant, reflectance measurements were taken from three leaves (L1, L2, L3) and at three positions on the leaf (P1, P2, P3). In addition, the N content (%) of the whole plant was determined by chemical lab analysis. Reflectance spectrometer measurements (400–1650 nm) were used to calculate 16 VI for each combination of leaf and position. N content (%) was predicted using each VI for each leaf and each position. Significant lower mean residual error variance (MREV) was found for leaves L1 and L3 and for measurement position on P3 in the N trial, but the difference of MREV between the leaves was very low and therefore considered as not relevant. The drought stress trial also led to no significant differences in MREV between leaves and positions. Neither the position on the leaf nor the leaf number had an impact on the accuracy of plant nitrogen determination via spectral reflectance measurements, wherefore measurements taken at the canopy level seem to be a valid approach.

Leaf Color Chart (LCC) is a measurement tool that can be used to measure the color intensity of rice leaves. The function of these measurements is to find out how many doses of fertilizer are needed by rice plants. However, readings made by human vision have a high level of subjectivity and risk of error. Therefore we need a method that can minimize errors and the level of subjectivity. One method that can be done is to classify the green color of rice leaves using LAB color space. Rice leaf image taken using a smartphone device is then extracted in RGB format. The color is then converted to LAB color space and then compared to the standard green color in the LCC. The comparison results are then used to classify the colors. The testing results show that the method has the value of accuracy, average precision, and average recall of 54.74%, 54.44%, and 51.16% respectively. Therefore the method can only classify correctly half of the data testing.

Reflectance measurements at leaf and canopy scales were made in a red-blush pear (Pyrus communis) orchard for two growing seasons. Canopy reflectance measurements were obtained using a multispectral camera flown on board an unmanned aerial vehicle (UAV), and leaf reflectance measurements were undertaken in a laboratory using a portable spectrometer. These measurements were used to compute reflectance indices as surrogates for direct leaf nitrogen (N) concentration measurements. The indices were evaluated against laboratory analysis of leaf N concentration. Regression results for leaf %N on canopy-level measurements with the multispectral camera resulted in the highest R2 value [R2 = 0.67; root mean square error (RMSE) = 0.24%N] with a new index, Modified Canopy Chlorophyll Content Index (M3CI)_710 nm. Regression results for leaf %N on leaf-level measurements in-laboratory resulted in the highest R2 value (R2 = 0.65) with two other indices, Normalized Difference Vegetation Index (NDVI) and Normalized Difference Red-edge Index (NDRE)_720 nm. The corresponding RMSE values were 0.26%N. The results indicate that reflectance indices measured at the leaf level, with a controlled light source and calibration, could be used to estimate leaf %N. An analysis of uncertainty indicated that if leaf %N is estimated from leaf-level reflectance values, 10 or more leaves (from the same tree) should be averaged. The results support the use of a UAV-based assessment for canopy %N using the M3CI_710 nm, which could provide spatial information of leaf N concentration across an orchard.

Abstract. Plants emit considerable quantities of volatile organic compounds (VOCs), the identity and amount of which vary with temperature, light, and other environmental factors. Portable photosynthesis systems are a useful method for simultaneously quantifying in situ leaf-level emissions of VOCs and plant physiology. We present a comprehensive characterization of the LI-6800 portable photosynthesis system's ability to be coupled to trace gas detectors and measure leaf-level trace gas emissions, including limits in flow rates, environmental parameters, and VOC backgrounds. Instrument contaminants from the LI-6800 can be substantial but are dominantly complex molecules such as siloxanes that are structurally dissimilar to biogenic VOCs and thus unlikely to interfere with most leaf-level emissions measurements. We validate the method by comparing CO2 assimilation calculated internally by the portable photosynthesis system to measurements taken with an external CO2 gas analyzer; these assimilation measurements agree within 1 %. We also demonstrate both online and offline measurements of plant trace gas exchange using the LI-6800. Offline measurements by pre-concentration on adsorbent cartridges enable the detection of a broad suite of VOCs, including monoterpenes (e.g., limonene) and aldehydes (e.g., decanal). Online measurements can be more challenging if flow rates require dilution with ultrapure zero air. We use high-resolution time-of-flight chemical ionization mass spectrometry coupled to the LI-6800 to measure the direct plant emission of formic acid.

This study has provided a landscape level estimate of leaf area index (LAI) and net primary productivity (NPP) for a temperate broadleaf forest ecosystem in south-central Indiana. The estimates were compared with the Moderate Resolution Imaging Spectroradiometer (MODIS) biophysical products LAI and NPP from both spatial and temporal perspectives. The evidence suggests that field-based estimates were poorly correlated with global MODIS data due to the simplifying assumptions of the MODIS global applicability, saturation problems of the red reflectance in highly vegetated areas, homogeneous land cover types of the study area, and other design assumptions of the field-based estimates. To improve the localized applicability of MODIS product algorithms, an empirical and localized algorithm combining in-situ measurements, the buildup of a localized biophysical model, and remote sensing-derived data were suggested for each local-scaled ecosystem.
Department of Natural Resources and Environmental Management

Plants emit a diverse range of biogenic volatile organic compounds (BVOCs) into the atmosphere, of which isoprene is the most abundantly emitted. Isoprene significantly affects biological and atmospheric processes, but the range of isoprene and BVOCs present in bamboos has not been well characterized. In this thesis I explore the range of isoprene emission found in bamboos and relate it to plant morphological and physiological characteristics. In addition, I measure and relate the entire suite of BVOCs present in the bamboos to their fundamental isoprene emission rate. Interspecific variation in isoprene emission documented in a comprehensive survey of bamboos. Two groups of bamboo species were measured in the greenhouse and the field. Elevated photosynthetic rate was significantly correlated with isoprene emission. In the field, dark respiration rate was highest in bamboos that made the least amount of isoprene. The total BVOC suite was significantly influenced by whether or not leaf-level isoprene emission was present. I conclude that bamboos vary with regard to physiology, morphology, and total BVOC suite and that isoprene emission is correlated with these changes, and introduce the bamboos as a novel system for studying the impacts of isoprene emission.

Thesis (Ph. D.)--Ohio State University, 2004.
Title from first page of PDF file. Document formatted into pages; contains xvii, 220 p. : ill. (some col.). Advisor: Peter T. Ward, Dept. of Business Administration. Includes bibliographical references (p. 197-203).

Ph.D., Faculty of Science, University of the Witwatersrand, 2011
Deep-level gold mining in the Witwatersrand Basin Goldfields (WBG) of central South Africa is characterised by the production of extensive unlined tailings storage facilities (TSFs) comprising large quantities of pulverised rock and water contaminated with salts and a wide range of other inorganic pollutants (Weiersbye et al., 2006). There are more than 200 such TSFs covering a total area of more than 400 km2 (Rosner et al., 2001), and significant contaminated “footprint” areas occur after removal and reprocessing of the original TSFs (Chevrel et al., 2003). It is estimated that the Witwatersrand Basin contains six billion tons of gold and uranium tailings (Chevrel et al., 2003), 430 000 tons of uranium (Council of Geoscience, 1998; Winde, 2004a; b; c) and approximately 30 million tons of sulphur (Witkowski and Weiersbye, 1998a). An estimated 105 million tons of waste per annum is generated by the gold mining industry within the WBG (Department of Tourism, Economic and Environmental Affairs, 2002; Chamber of Mines of South Africa, 2004). A major environmental problem resulting from deep level mining in the WBG is the contaminated water that seeps from TSFs into adjacent lands and groundwater. Van As (1992) reported on the significant environmental hazards resulting from the storage of highly pulverised pyrite rock waste in TSFs (Straker et al., 2007). Adjacent lands become polluted through near-surface seepage, and this is enhanced by the movement of polluted groundwater in shallow aquifers that are commonly 1-30 m below ground (Funke, 1990; Hodgson et al., 2001; Rosner et al., 2001; Naicker et al., 2003). The impact of the mines and the TSFs extends far beyond their localities (Cogho et al., 1990). The Vaal River catchment receives a large proportion of the pollutants from WBG mining activities, with consequent acidification and salinisation of surface and ground waters. Salt discharges to the Vaal River were estimated to be 170 000 t/annum (Best, 1985), whereas discharges from the Free State gold mines south of the Vaal catchment were estimated at 350 000 t/annum of salts (Cogho et al., 1990). Concern also exists over the spread of dangerous contaminants such as uranium, chromium and mercury (Coetzee et al., 2006; Winde, 2009). Engineering solutions to these problems are hindered by the large sizes and great extent of TSFs, the high and indefinite costs involved, and the typically low hydraulic conductivity in affected aquifers, which makes the “pump and treat” option impractical. An alternative phytoremediation strategy is to establish belts or blocks of trees in strategic areas surrounding the TSFs in order to reduce the seepage of contaminated water into adjacent lands and groundwater bodies. The major reasons why trees are likely to have a greater impact on seepage water than the existing grasslands that characterise the area around most TSFs in the WBG, are that some tree species have the potential to develop very deep root systems and to continue transpiring water throughout the year. This is in contrast to seasonally dormant grasslands. In addition, some tree species are known to be tolerant to salts and other pollutants. Trees are thus potentially able to reach deep water tables, take up large quantities of water, and remove some of the pollutants in this water. It is crucial for a successful implementation of this strategy to know on what sites trees are able to access mine seepage water, and consequently maintain a high year-round rate of water use. If this access is limited, then growth and water use will be curtailed during the long winter dry season, and control of seepage will be considerably below potential. A primary aim of this study was to develop methodologies to discriminate between water-stressed and non-water-stressed trees currently growing in three gold mining districts (Welkom, Vaal River, West Wits) within the WBG. This information was required to assess what site types are likely to support adequate tree growth and permit high rates of water use and seepage control. The tree species selected were those most widely occurring in these areas, and include the non-native species Eucalyptus sideroxylon A. Cunningham ex Woolls and Eucalyptus camaldulensis Dehnhardt, as well as the indigenous species Searsia lancea L.f. Various remote sensing technologies including leaf-level spectroscopy, satellite and airborne remote sensing images were evaluated for their usefulness in detecting levels of winter-time water stress. Four commonly used ground-truthing techniques (predawn leaf water potential, leaf chlorophyll fluorescence, leaf chlorophyll and carotenoid pigment content, and leaf water content) were used for localised measurements of plant water stress and for ground-truthing of remotely sensed data on 75 sample sites and 15 sample sites. This study provided a unique opportunity to test and compare the use of stress reflectance models derived from different remote sensing data acquired at different spatial and spectral resolutions (i.e. multispectral and hyperspectral) for the same geographical location. The use of remote sensing to examine the spectral responses of vegetation to plant stress has been widely described in the scientific literature. A collation of published spectral reflectance indices provided the basis for investigating the use of hand-held remote sensing technology to detect plant water stress, and was used as a stepping stone to further develop spectral plant water stress relationships for specific tree species in this study. Seventy seven spectral reflectance indices and specific individual spectral wavelengths useful for detecting plant water stress, plant pigment content, the presence of stress related pigments in vegetation, and changes in leaf cellular structure, were investigated using hand-held spectroscopy. Ground-based measurements of plant water stress were taken on 75 sample trees. In this study, the measurement of predawn leaf water potential has been identified as a key methodology for linking remotely sensed assessments of plant water stress to actual plant water stress; a reading of -0.8 MPa was used to separate stressed trees from unstressed trees in the landscape (Cleary and Zaerr, 1984). The results of the predawn leaf water potential measurements ranged from -0.56 to -0.68 MPa at unstressed sites, and from -0.93 to -1.78 MPa at stressed sites. A novel approach of using spectral reflectance indices derived from previous studies was used to identify specific indices which are applicable to South Africa and to the three species investigated in the WGB. Maximal multiple linear regression models were derived for all possible combinations of plant water stress measurements and the 77 spectral reflectance indices extracted from leaf-level spectral reflectance data, and included the interactions of district and species. The results of the multiple linear regression models indicated that the (695/690) index, DATT index (850-710)/(850-680), near infra-red index (710/760) and the water band (900/970) index performed well and accounted for more than 50% of the variance in the data. The stepwise regression model derived between chlorophyll b content and the DATT index was selected as the “best” model, having the highest adjusted R2 of 69.3%. This was shown to be the most robust model in this application, which could be used at different locations for different species to predict chlorophyll content at the leaf-level. Satellite earth observation data were acquired from two data sources for this investigation; the Hyperion hyperspectral sensor (United States Geological Survey Earth Resources Observation Systems) and the Proba Chris pseudo-hyperspectral sensor (European Space Agency). The Hyperion sensor was selected to obtain high spatial and spectral resolution data, whereas the Proba Chris sensor provided high spatial and medium spectral resolution earth observation data. Twelve vegetation indices designed to capture changes in canopy water status, plant pigment content and changes in plant cellular structure, were selected and derived from the satellite remote sensing imagery. Ground-based measurements of plant water stress undertaken during late July 2004 were used for ground-truthing the Hyperion image, while measurements undertaken during July 2005 and August 2005 were used for ground-truthing the Proba Chris images. Predawn leaf water potential measurements undertaken for the three species, ranged from -0.42 to -0.78 MPa at unstressed sites, and -0.95 to -4.66 MPa at stressed sites. Predawn leaf water potentials measured for E. camaldulensis trees sampled in species trials in Vaal River were significantly different between stressed and non stressed trees (t = 3.39, 8df, P = 0.009). In contrast, E. camaldulensis trees sampled near a pan within the Welkom mining district, which had greater access to water but were exposed to higher concentrations of salts and inorganic contaminants, displayed differences in total chlorophyll content (t = -2.20, 8df, P = 0.059), carotenoid content (t = -5.68, 8df, P < 0.001) and predawn leaf water potential (t = 4.25, 8df, P = 0.011) when compared to trees sampled on farmland. E. sideroxylon trees sampled close to a farm dam in the West Wits mining district displayed differences in predawn leaf water potential (t = 69.32, 8df, P < 0.001) and carotenoid content (t = -2.13, 8df, P = 0.066) when compared to stressed trees further upslope away from the water source. Multiple linear regressions revealed that the predawn leaf water potential greenness normalised difference vegetation index model, and the predawn leaf water potential water band index model were the “best” surrogate measures of plant water stress when using broad band multispectral satellite and narrow-band hyperspectral satellite data respectively. It was concluded from these investigations that vegetation indices designed to capture changes in plant water content/plant water status and spectral changes in the red edge region of the spectrum, performed well when applied to high spectral resolution remote sensing data. The greenness normalised difference vegetation index was considered to be a fairly robust index, which was highly correlated to chlorophyll fluorescence and predawn leaf water potential. It is recommended that this index has the potential to be used to map spatial patterns of winter-time plant stress for different genera/species and in different geographical locations. Airborne remote sensing surveys were conducted to investigate the application of high spatial resolution remote sensing data to detect plant water stress. Multispectral airborne imagery was acquired by Land Resource International (PTY) Ltd, South Africa. Ground-based measurements of plant water stress were carried out during July and August 2005.Four individual spectral bands and two vegetation spectral reflectance indices, which are sensitive to changes in plant pigment content, were derived from the processed multispectral images viz. red, green, blue and near-infrared spectral bands and the normalised difference vegetation index (NDVI) and greenness normalised difference vegetation index (GNDVI).The results of the multispectral airborne study revealed that carotenoid content together with the green spectral waveband resulted in the “best” surrogate measure of plant water stress when using broad-band multispectral airborne data. Airborne remote sensing surveys were conducted by Bar-Kal Systems Engineering Ltd, Israel, to investigate the application of hyperspectral airborne imagery to detect plant water stress. Six vegetation spectral reflectance indices designed to capture changes in plant pigment and plant water status/content, were derived from the processed hyperspectral images. When using airborne hyperspectral data, predawn leaf water potential with the normalized difference water index was selected as the most appropriate model. It was concluded, upon evaluation of the multiple linear regression models, that the airborne hyperspectral data produced several more regression models with higher adjusted R2 values (Ra2 range 6.2 - 76.2%) when compared to the airborne multispectral data (Ra2 range 6 - 50.1). Exploration of relationships between vegetation indices derived from leaf-level, satellite and airborne spectral reflectance data and ground-based measurements used as “surrogate” measures of plant water stress, revealed that several prominent and recurring spectral reflectance indices could be applied to identify species-specific plant water stress within the Welkom, Vaal River and West Wits mining districts. The models recommended for mapping and detecting spatial patterns of plant water stress when using different sources of remote sensing data are as follows: the chlorophyll b DATT spectral reflectance model when derived from leaf-level spectral reflectance data, can be applied across all three mining districts the predawn leaf water potential GNDVI spectral reflectance model and predawn leaf water potential water band index spectral reflectance model when utilising satellite multispectral and hyperspectral remote sensing data carotenoid content green band spectral reflectance model can be used for airborne multispectral resolution data predawn leaf water potential NDVI spectral reflectance model is best suited for airborne high spatial and hyperspectral resolution data. These results indicate that measurements of predawn leaf water potential and plant pigment content have been identified as key methodologies for ground-truthing of remotely sensed data and can be used as surrogate measures of plant water stress. Some preliminary research was undertaken to evaluate if wood anatomy characteristics could be used as a non-destructive and rapid low-cost survey approach for identifying trees which are experiencing long-term plant stress. Seventy two wood core samples were extracted and analysed. Predawn leaf water potential measurements were used to classify stressed and unstressed trees. Relative differences in radial vessel diameter, vessel frequency and wood density were examined. Comparison of the radial vessel diameter and vessel frequency measurements revealed significant differences in three of the five comparative sampling sites (p <0.05). The results of the density analyses were significantly different for all five comparative sampling sites (p < 0.01). In general, trees experiencing higher plant water stress displayed smaller vessel diameters, compared to less stressed or healthy trees. Sites which were influenced by high levels of contaminated water also displayed smaller vessel diameters, indicating that the uptake of contaminants could affect the wood anatomy of plants. Trees considered to be experiencing higher plant water stress displayed higher vessel frequency. This preliminary study showed that plant stress does influence the wood anatomical characteristics (radial vessel diameter, vessel frequency and wood density) in E. camaldulensis, E. sideroxylon and S. lancea in the three mining districts. Spatial patterns of trees, mapped in the three gold mining districts, Welkom (27º57´S, 26º34´E) in the Free State Province, Vaal River (26º55´S, 26º40´E) located in the North West Province, and West Wits (26º25´S, 27º21´E) located in Gauteng, which were not experiencing winter-time water stress were correlated to site characteristics such as average soil depth, percent clay in the topsoil, groundwater chloride and sulphate concentrations, total dissolved solids, electrical conductivity and groundwater water level. The spectral reflectance model derived between predawn leaf water potential and the green normalised difference vegetation index using broad-band multispectral Proba Chris satellite data was used to map spatial patterns of unstressed trees across the three mining districts. Very high resolution (75 cm) multispectral airborne images acquired by LRI in 2005 were used to demarcate and classify vegetation using the maximum likelihood supervised classification technique. Interpolated surfaces of groundwater chloride and sulphate concentrations, total dissolved solids, electrical conductivity, pH and groundwater table levels were created using the kriging geostatistical interpolation technique for each mining district. Random sample analyses between stressed and unstressed trees were extracted in order to determine whether site characteristics were significantly different (using t-tests). Site characteristic surfaces which were significantly different from stressed areas were spatially linked to trees which were not experiencing winter-time plant water stress for each tree species investigated in each mining district. This spatial correlation was used to make recommendations and prioritise sites for the establishment of future block plantings. Analysis of the site characteristic data and the geophysical surveys undertaken in the three mining districts which provided detailed information on groundwater saturation and an indication of the salinity conditions, confirmed the presence of relatively shallow and saline groundwater sources. This would imply that tree roots could access the relatively shallow groundwater even during the dry winter season and assist in containing contaminated groundwater seeping into surrounding lands. Keywords : airborne imagery, ground-based measurements of plant water stress, hyperspectral, leaf-level spectroscopy, multispectral, satellite imagery, spatial patterns of unstressed trees, spectral reflectance indices

The three major diabetic emergencies comprise diabetic ketoacidosis (DKA), hyperglycaemic hyperosmolar state (HHS), and prolonged hypoglycaemia. These complications are preventable, treatable, and rather infrequently lead to prolonged intensive care (ICU) admission. Hyperglycaemic crises, whether DKA in type 1 diabetics, or HHS in type 2 diabetics, are characterized by moderate to severe hypovolaemia, electrolyte disturbances and a potentially life-threatening trigger. Hence, airway–breathing–circulation securement, diagnosis, and treatment of the underlying condition, as well as fluid resuscitation are the cornerstones of the acute management of DKA and HHS. Currently, a continuous, low (physiological) dose insulin scheme intravenously with omission of the priming bolus is advocated to avoid hypoglycaemia. An evidence-based treatment protocol, and reliable blood glucose and electrolyte measurements are compulsory to safely manage these crises until resolution of ketoacidosis or the hyperosmolar state. Profound hypoglycaemia should be suspected in every coma patient with an indistinct history or on a known regimen of insulin or sulphonylurea/meglitinide. This condition warrants immediate and sufficiently long administration of glucose orally or intravenously, as well as repeated monitoring of blood glucose levels. Alternatively, the counter-regulatory hormone glucagon may be injected intramuscularly in the emergency setting.

The aim of the study was to determine the influence of different disturbances (both natural and anthropogenic) on species composition and stand structure of old-growth mixed mountain forests in the Western Carpathians. These stands are usually dominated by beech, fir and spruce, mixed in different proportions. The tree main species represent different growth strategies, and they compete against each other. The longevity of trees makes the factors influencing the stand structure difficult to identify, even during longitudinal studies conducted on permanent research plots. That is why dendroecological techniques, based upon the annual variability of tree rings, are commonly used to analyze the disturbance histories of old-growth stands. Dendroecological methods make it possible to reconstruct the stand history over several centuries in the past by analyzing the frequency, intensity, duration and spatial scale of disturbances causing the death of trees. Combining the dendroecological techniques with the detailed measurements of stand structure, snag volume, CWD volume, and the analyses of regeneration species composition and structure allows us to identify the factors responsible for the changes in dynamics of mixed mountain forests. Various disturbance agents affect some species selectively, while some disturbances promote the establishment of tree seedlings of specific species by modifying environmental conditions. Describing the disturbance regime requires a broad scope of data on stand structure, on dead wood and tree regeneration, while various factors affecting all the stages of tree growth should be taken into consideration. On the basis of the already published data from permanent sample plots, combined with the available disturbance history analyses from the Western Carpathians, three research hypotheses were formulated. 1. The species composition of mixed mountain forests has been changing for at least several decades. These directional changes are the consequence of simultaneous conifer species decline and expansion of beech. 2. The observed changes in species composition of mixed mountain forests are the effect of indirect anthropogenic influences, significantly changing tree growth conditions also in the forests that are usually considered natural or near-natural. Cumulative impact of these indirect influences leads to the decrease of fir share in the tree layer (spruce decline has also been observed recently),and it limits the representation of this species among seedlings and saplings. The final effect is the decrease of fir and spruce share in the forest stands. 3. Small disturbances, killing single trees or small groups of trees, and infrequent disturbances of medium size and intensity dominate the disturbance regime in mixed mountain forests. The present structure of beech-fir-spruce forests is shaped both by complex disturbance regime and indirect anthropogenic influences. The data were gathered in permanent sample plots in strictly protected areas of Babia Góra, Gorce, and Tatra National Parks, situated in the Western Carpathians. All plots were located in the old-growth forest stands representing Carpathian beech forest community. The results of the measurements of trees, snags, coarse woody debris (CWD) and tree regeneration were used for detailed description of changes in the species composition and structure of tree stands. Tree ring widths derived from increment cores were used to reconstruct the historical changes in tree growth trends of all main tree species, as well as the stand disturbance history within the past two to three hundred years. The analyses revealed complex disturbance history in all of the three forest stands. Intermediate disturbances of variable intensity occurred, frequently separated by the periods of low tree mortality lasting from several decades up to over one hundred years. The intervals between the disturbances were significantly shorter than the expected length of forest developmental cycle, in commonly used theories describing the dynamics of old-growth stands. During intermediate disturbances up to several dozen percent of canopy trees were killed. There were no signs of stand-replacing disturbances, killing all or nearly all of canopy trees. The periods of intense tree mortality were followed by subsequent periods of increased sapling recruitment. Variability in disturbance intensity is one of the mechanisms promoting the coexistence of beech and conifer species in mixed forests. The recruitment of conifer saplings depended on the presence of larger gaps, resulting from intermediate disturbances, while beech was more successful in the periods of low mortality. However, in the last few decades, beech seems to benefit from the period of intense fir mortality. This change results from the influence of long-term anthropogenic disturbances, affecting natural mechanisms that maintain the coexistence of different tree species and change natural disturbance regimes. Indirect anthropogenic influence on tree growth was clearly visible in the gradual decrease of fir increments in the twentieth century, resulting from the high level of air pollution in Europe. Synchronous decreases of fir tree rings’ widths were observed in all three of the sample plots, but the final outcomes depended on the fir age. In most cases, the damage to the foliage limited the competitive abilities of fir, but it did not cause a widespread increase in tree mortality, except for the oldest firs in the BGNP (Babia Góra National Park) plot. BGNP is located in the proximity of industrial agglomeration of Upper Silesia, and it could be exposed to higher level of air pollution than the other two plots. High level of fir regeneration browsing due to the deer overabundance and insufficient number of predators is the second clear indication of the indirect anthropogenic influence on mixed mountain forests. Game impact on fir regeneration is the most pronounced in Babia Góra forests, where fir was almost completely eliminated from the saplings. Deer browsing seems to be the main factor responsible for limiting the number of fir saplings and young fir trees, while the representation of fir among seedlings is high. The experiments conducted in fenced plots located in the mixed forests in BGNP proved that fir and sycamore were the most preferred by deer species among seedlings and saplings. In GNP (Gorce National Park) and TNP (Tatra National Park), the changes in species composition of tree regeneration are similar, but single firs or even small groups of firs are present among saplings. It seems that all of the analysed mixed beech-fir-spruce forests undergo directional changes, causing a systematic decrease in fir representation, and the expansion of beech. This tendency results from the indirect anthropogenic impact, past and present. Fir regeneration decline, alongside with the high level of spruce trees’ mortality in recent years, may lead to a significant decrease in conifers representation in the near future, and to the expansion of beech forests at the cost of mixed ones.

AbstractAn historic shift in focus on the quality and person-centeredness of health care has occurred in the last two decades. Accounts of results produced from reinvigorated attention to the measurement, management, and improvement of the outcomes of health care show that much has been learned, and much remains to be done. This article proposes that causes of the failure to replicate in health care the benefits of “lean” methods lie in persistent inattention to measurement fundamentals. These fundamentals must extend beyond mathematical and technical issues to the social, economic, and political processes involved in constituting trustworthy performance measurement systems. Successful “lean” implementations will follow only when duly diligent investments in these fundamentals are undertaken. Absent those investments, average people will not be able to leverage brilliant processes to produce exceptional outcomes, and we will remain stuck with broken processes in which even brilliant people can produce only flawed results. The methodological shift in policy and practice prescribed by the authors of the chapters in this book moves away from prioritizing the objectivity of data in centrally planned and executed statistical modeling, and toward scientific models that prioritize the objectivity of substantive and invariant unit quantities. The chapters in this book describe scientific modeling’s bottom-up, emergent and evolving standards for mass customized comparability. Though the technical aspects of the scientific modeling perspective are well established in health care outcomes measurement, operationalization of the social, economic, and political aspects required for creating new degrees of trust in health care institutions remains at a nascent stage of development. Potentials for extending everyday thinking in new directions offer hope for achieving previously unattained levels of efficacy in health care improvement efforts.

AbstractSmoke plume dynamic science focuses on understanding the various smoke processes that control the movement and mixing of smoke. A current challenge facing this research is providing timely and accurate smoke information for the increasing area burned by wildfires in the western USA. This chapter synthesizes smoke plume research from the past decade to evaluate the current state of science and identify future research needs. Major advances have been achieved in measurements and modeling of smoke plume rise, dispersion, transport, and superfog; interactions with fire, atmosphere, and canopy; and applications to smoke management. The biggest remaining gaps are the lack of high-resolution coupled fire, smoke, and atmospheric modeling systems, and simultaneous measurements of these components. The science of smoke plume dynamics is likely to improve through development and implementation of: improved observational capabilities and computational power; new approaches and tools for data integration; varied levels of observations, partnerships, and projects focused on field campaigns and operational management; and new efforts to implement fire and stewardship strategies and transition research on smoke dynamics into operational tools. Recent research on a number of key smoke plume dynamics has improved our understanding of coupled smoke modeling systems, modeling tools that use field campaign data, real-time smoke modeling and prediction, and smoke from duff burning. This new research will lead to better predictions of smoke production and transport, including the influence of a warmer climate on smoke.

AbstractEver since international large-scale student assessments made it possible to rank countries according to their equitability, Nordic countries have topped these rankings. Nevertheless, a decline in equity has been reported lately. However, the process of empirical enquiry that leads to specific inferences on equity partly stays obscure to education decision-makers. This unawareness of the boundaries of specific methodological and analytical approaches may lead to wrong interpretations and policy implications. Therefore, our aim is to discuss and empirically illustrate how the array of choices taken throughout the research process, from equity conceptualization and operationalization to its measurement, may affect the inferences on educational equity for Nordic countries. Our sample includes fourth- and eighth-grade students from Norway, Sweden, Denmark and Finland who participated in TIMSS 2015. We applied two-level multigroup regression models within the structural equation modelling framework to investigate the sensitivity of the countries’ level of equity to: (a) operationalization of the socioeconomic status measure; (b) operationalization of equity or, in other words, the method of analysis employed (e.g., bivariate analysis versus univariate); (c) single-level against multilevel analytical approaches; (d) the grade/age of students; and (e) the choice of the learning outcome across subject domains. Prior to the analyses, we estimated the comparability of SES as a latent construct between Nordic countries. Our results confirmed that some of the most common choices to measure educational equity do matter. Thus, we would encourage a researcher to report elaborately on the research process and inform on its limitations because if interpreted wrongly, it may have unfavourable consequences for a particular group of individuals.

This chapter steps back and examines several fundamental quantum issues. Although not strictly needed for QIS and QC, these issues help the reader understand why quantum computing provides capabilities that go far beyond those of classical computers. Alice and Bob lead look at a specific instantiation of Bell’s theorem and why, nearly 60 years after its publication, it continues to roil discussions about the foundations of quantum mechanics and the implications for what we can say about the physical nature of the world. Equally controversial, at the foundational level, is the problem of describing quantum measurements and their probabilistic results. Alice and Bob show that entanglement issues lie at the core of many of the debates about measurement and that correlations among measurement outcomes can reveal entanglement. They also explain why Planck’s constant, a critical parameter in quantum mechanics, plays only a limited role in quantum information science.

Non-ferrous metals play an important role in the national economy, and more and more attention has been paid to their efficient large-scale production. However, the non-ferrous metal production plant environment is bad, the ingot line vibration is violent, the surface of the metal solution also has strong reflective, these adverse factors lead to the automatic detection of the level measurement process in the non-ferrous metal production is very difficult, have to retain a large number of manual links. In order to solve the above problems, an automatic measurement system of non-ferrous metal solution level based on structured light triangulation is established. The system adopts filtering algorithm based on statistics to suppress the adverse effect of ingot line vibration on measurement. At the same time, by increasing the Angle between the optical axis of the camera and the laser plane, the influence of the strong reflection of the solution surface on the measurement can be reduced. The relative error of the system can be controlled within 1.3%, which can meet the actual measurement demand in engineering.

A successful e-government implementation cannot do without some kind of business process change, not only of the front-office parts of processes, but the entire processes, which often flow through several departmental units or even several government agencies. Further advances of e-government that lead to t-government, are not possible without an integration of business processes. The implementation of t-government requires a high level of business process orientation and typically involves a business process change project. Non-profit organisations have some specifics, which make process renovation projects considerably different. The purpose of this chapter is to present an approach that enables governmental institutions to move towards t-government. The general framework for business process change methodologies, techniques and tools is customised for their needs and extended with several other business process management elements, e.g. measurement of the level of business process orientation in an organisation. The relationship between business process orientation levels and the sophistication of online services is shown through a case study of one of the Slovene ministries, where the proposed adapted methodology has been successfully employed.

To meet customer’s needs for high-quality goods and avoiding risks of product-liability, global firms continually evaluate the performance of their supply chain for optimum design. Lean management is one of the key techniques businesses adopt in redesigning their processes. The technique is a vital strategy to increase productivity and effectiveness with respect to the movement of goods. Multivariate Analysis of Variance (MANOVA) was utilized to evaluate the performance of work cell, shift, worker’s experience, and kaizen event participation level during a lean enterprise deployment effort at a multinational organization. The significance of the effects of these variables were assessed based on various lean supply chain factors such as First In First Out (FIFO), Setup Wheel System (SWS), Standard Operating Procedures (SOP), Clip System(CS), and Key Performances Indicators (KPI). The results support the criticality of metrics and their impact in implementing a lean manufacturing process in a global supply chain environment.

Circular economics (CE) is increasingly discussed among researchers, practitioners, and politicians. The discussions between the parties and the confusion about the concept cause the issue to remain on the agenda. According to the general view, CE is the slowing, shrinking, and closing of the welding flow to increase the welding efficiency. However, little attention has been devoted to measuring the CE level of a given economic system. The aim of this chapter is to demonstrate the emergence and development process of CE, and also to show how the CE level of any economic system can be measured. In this context, it is important for developing countries to interest with the issue but not in practice. To put this into perspective, the study examined Turkey's economic system. Turkey's economic, environmental, and social indicators examined were found to have a remote structure of the CE principle. It is expected that the results of the study will lead to a positive social change and become a framework for increasing the contribution of developing economies to the sustainable world.

The efficient work of the employees is important for the adaptation of the business to the rapidly changing environmental conditions. Businesses should identify the factors that affect employee productivity and emerging threats because the efficient level of performance and the measurability of this output lead to rational use of the resources. Employees who do not fulfill their duties and responsibilities in the organization and take a share from the group product may lead to deviations in reaching the targets set by the organization. Justice in the organization, trust, the deterioration in the values may adversely affect the process. The existence of such employees is the indicator of parasitic relations in organizations. In literature, the number of applied studies is limited. The strength of the study is to provide a detailed evaluation and measurement tool in the subject of parasitism in organizations. The scale of parasitism was developed with self-directed and community-directed dimensions consisting of 20 statements and was validated by EFA, CFA, and reliability analysis.

In this research work the potential of rich quench lean combustion for low emission aeroengines is investigated in a rectangular atmospheric sector, representing a segment of an annular combustor. For a constant design point (cruise) the mixing process and the NOx formation are studied in detail by concentration, temperature and velocity measurements using intrusive and non-intrusive measuring techniques. Measurements at the exit of the homogeneous primary zone show relatively high levels of non-thermal NO. The NOx formation in the quench zone is very low due to the quick mixing of the secondary air achieved by an adequate penetration of the secondary air jets and a high turbulence level. The NOx and CO emissions at the combustor exit are low and the pattern factor of the temperature distribution is sufficient.

Abstract The development of jet engines is typically accompanied by measurement campaigns to mitigate technical risks at an early design stage and to validate the specified performance. Often different configurations are compared in order to determine the superior one. But due to uncertainties in boundary conditions, geometry, and sensors, the derived performance values are subject to uncertainty as well. Assuming that the desired difference in performance metrics is small compared to the associated uncertainty, it can consequently be hard to conclude on the superiority of the configurations. In this paper, a probabilistic approach is used to estimate the uncertainties of the output values of interest. For that, the measurement process is executed virtually taking the low-speed research compressor of Technische Universität Dresden as a test case. In the first step, a sampling for the uncertainties associated with boundary conditions and geometry is created. Then, Computational Fluid Dynamics (CFD) calculations for these samples are executed. Afterwards, virtual measurements are performed, for which the unbiased value of the measurement quantity of interest is extracted from the CFD calculation and then merged with a measurement uncertainty. Finally, these virtual measurements are evaluated in the same way as it is done for real measurements to derive the output values. Evaluating the samples allows to obtain the associated uncertainties and hence the confidence levels of a measurement campaign which are to be optimized. The system behavior is first approximated with an inner meta model. This surrogate can be used to create an outer meta model describing the relationship between the variance of the input variables and the uncertainties of the output variables. By evaluating the outer meta model it is possible to identify important input variables effecting the uncertainty of the output variables. Finally, the outer meta model is used to find combinations of input variances, which on one hand lead to the desired output uncertainties and on the other hand are optimal with respect to the associated cost.

Suncor Energy Inc. contacted Synodon as part of an effort to enhance pipeline leak detection. Ideally, Suncor needed a technology that could detect natural gas as well as liquid hydrocarbon releases. Synodon’s new technology is an aircraft mounted gas remote sensing instrument that has been used for detecting leaks from natural gas pipelines for over four (4) years and was expanding their capability to include liquid hydrocarbons. This paper will describe the steps that Suncor and Synodon have taken over the last two years to develop and validate this detection technology. Synodon completed a number of studies including laboratory and field tests that demonstrated the ability of Synodon’s technology to remotely detect ground-level plumes of vapours released from a liquid hydrocarbon pipeline. Synodon conducted full atmospheric analytic modeling followed by laboratory measurements to determine the level of sensitivity of its instrument measurement to both methane and various liquid hydrocarbon vapors including gasoline, condensates and synthetic crude oil. Suncor participated in the development of test methodology and field execution in order to witness and validate the results. Based on this work, Suncor has determined an optimum inspection frequency based on theoretical spill size, SCADA leak detection thresholds and conventional aerial patrol constraints. The results and conclusions of this work will be presented.

A novel Bayesian Network methodology has been developed to enable the prediction of fatigue fracture of cardiac lead medical devices. The methodology integrates in-vivo measurements of device loading, patient demographics, patient activity level, in-vitro measurements of fatigue strength, and cumulative damage modeling techniques. Many plausible combinations of these variables can be simulated within a Bayesian Network framework to generate a family of fatigue fracture survival curves, enabling sensitivity analyses and the construction of confidence bounds on survival.

Experimental evidence correlating equivalence ratio fluctuations with combustion instabilities and NOX emissions in a jet-A fueled lean premixed prevaporized (LPP) combustor utilizing a non-proprietary ‘generic’ fuel injector is presented. Real-time laser absorption measurements of equivalence ratio, together with dynamic combustor pressure, flame luminosity and fuel pressure were obtained at inlet air conditions up to 16.7 atm and 817 K. From this data, an extensive database of real-time variables was obtained for the purposes of providing validation data for future studies of LPP combustion modeling. In addition, time and frequency space analysis of the data revealed measurable levels of acoustic coupling between all variables. Equivalence ratio and dynamic pressure cross-correlations were found to predict the level of combustion instability. Furthermore, NOX production was found to follow the root-mean-square (RMS) flame luminosity and RMS combustor dynamic pressure. However, the unmixedness of the fuel-air mixture was not found to predict NOX production in this combustor. The generic LPP injector, although not optimized for low-emissions or combustion stability, provides some of the essential features of real injectors for the purposes of studying the relationship between fluctuations in equivalence ratios and combustion instability. In particular, the fuel premixer advection time was found to have a significant and direct impact on the level of combustion instability. The results of this work support the time-lag concept for avoiding combustion instability when designing injector/premixers in LPP combustors.

Background Early detection and identification of faulty greenhouse operation is essential, if losses are to be minimized by taking immediate corrective actions. Automatic detection and identification would also free the greenhouse manager to tend to his other business. Original objectives The general objective was to develop a method, or methods, for the detection, identification and accommodation of faults in the greenhouse. More specific objectives were as follows: 1. Develop accurate systems models, which will enable the detection of small deviations from normal behavior (of sensors, control, structure and crop). 2. Using these models, develop algorithms for an early detection of deviations from the normal. 3. Develop identifying procedures for the most important faults. 4. Develop accommodation procedures while awaiting a repair. The Technion team focused on the shoot environment and the Cornell University team focused on the root environment. Achievements Models: Accurate models were developed for both shoot and root environment in the greenhouse, utilizing neural networks, sometimes combined with robust physical models (hybrid models). Suitable adaptation methods were also successfully developed. The accuracy was sufficient to allow detection of frequently occurring sensor and equipment faults from common measurements. A large data base, covering a wide range of weather conditions, is required for best results. This data base can be created from in-situ routine measurements. Detection and isolation: A robust detection and isolation (formerly referred to as 'identification') method has been developed, which is capable of separating the effect of faults from model inaccuracies and disturbance effects. Sensor and equipment faults: Good detection capabilities have been demonstrated for sensor and equipment failures in both the shoot and root environment. Water stress detection: An excitation method of the shoot environment has been developed, which successfully detected water stress, as soon as the transpiration rate dropped from its normal level. Due to unavailability of suitable monitoring equipment for the root environment, crop faults could not be detected from measurements in the root zone. Dust: The effect of screen clogging by dust has been quantified. Implications Sensor and equipment fault detection and isolation is at a stage where it could be introduced into well equipped and maintained commercial greenhouses on a trial basis. Detection of crop problems requires further work. Dr. Peleg was primarily responsible for developing and implementing the innovative data analysis tools. The cooperation was particularly enhanced by Dr. Peleg's three summer sabbaticals at the ARS, Northem Plains Agricultural Research Laboratory, in Sidney, Montana. Switching from multi-band to hyperspectral remote sensing technology during the last 2 years of the project was advantageous by expanding the scope of detected plant growth attributes e.g. Yield, Leaf Nitrate, Biomass and Sugar Content of sugar beets. However, it disrupted the continuity of the project which was originally planned on a 2 year crop rotation cycle of sugar beets and multiple crops (com and wheat), as commonly planted in eastern Montana. Consequently, at the end of the second year we submitted a continuation BARD proposal which was turned down for funding. This severely hampered our ability to validate our findings as originally planned in a 4-year crop rotation cycle. Thankfully, BARD consented to our request for a one year extension of the project without additional funding. This enabled us to develop most of the methodology for implementing and running the hyperspectral remote sensing system and develop the new analytical tools for solving the non-repeatability problem and analyzing the huge hyperspectral image cube datasets. However, without validation of these tools over a ful14-year crop rotation cycle this project shall remain essentially unfinished. Should the findings of this report prompt the BARD management to encourage us to resubmit our continuation research proposal, we shall be happy to do so.

Increased production rates and cost reduction are affecting manufacturing in all sectors of the mobility industry. One enabling methodology that could achieve these goals in the burgeoning “Industry 4.0” environment is the deterministic assembly (DA) approach. The DA approach is defined as an optimized assembly process; it always forms the same final structure and has a strong link to design-for-assembly and design-for-automation methodologies. It also looks at the whole supply chain, enabling drastic savings at the original equipment manufacturer (OEM) level by reducing recurring costs and lead time. Within Industry 4.0, DA will be required mainly for the aerospace and the space industry, but serves as an interesting approach for other industries assembling large and/or complex components. In its entirety, the DA approach connects an entire supply chain—from part manufacturing at an elementary level to an OEM’s final assembly line level. Addressing the whole process of aircraft design and manufacturing is necessary to develop further collaboration models between OEMs and the supply chain, including addressing the most pressing technology challenges. Since all parts aggregate at the OEM level, the OEM—as an integrator of all these single parts—needs special end-to-end methodologies to drastically decrease cost and lead time. This holistic approach can be considered in part design as well (in the design-for-automation and design-for-assembly philosophy). This allows for quicker assembly at the OEM level, such as “part-to-part” or “hole-to-hole” approaches, versus traditional, classical assembly methods like manual measurement or measurement-assisted assembly. In addition, it can increase flexibility regarding rate changes in production (such as those due to pandemic- or climate-related environmental challenges). The standardization and harmonization of these areas would help all industries and designers to have a deterministic approach with an end-to-end concept. Simulations can easily compare possible production and assembly steps with different impacts on local and global tolerances. Global measurement feedback needs high-accuracy turnkey solutions, which are very costly and inflexible. The goal of standardization would be to use Industry 4.0 feedback and features, as well as to define several building blocks of the DA approach as a one-way assembly (also known as one-up assembly, or “OUA”), false one-way assembly, “Jig-as-Master,” etc., up to the hole-to-hole assembly approach. The evolution of these assembly principles and the link to simulation approaches are undefined and unsolved domains; they are discussed in this report. They must be discussed in greater depth with aims of (first) clarifying the scope of the industry-wide alignment needs and (second) prioritizing the issues requiring standardization. NOTE: SAE EDGE™ Research Reports are intended to identify and illuminate key issues in emerging, but still unsettled, technologies of interest to the mobility industry. The goal of SAE EDGE™ Research Reports is to stimulate discussion and work in the hope of promoting and speeding resolution of identified issues. SAE EDGE™ Research Reports are not intended to resolve the challenges they identify or close any topic to further scrutiny.

Over the last two decades, an increasing number of highway construction and maintenance projects in the United States have been completed at night to avoid or alleviate traffic congestion delays. Working at night entails several advantages, including lower traffic volumes, less impact on local businesses, cooler temperatures for equipment and material, and fewer overall crashes. Although nighttime roadway operations may minimize traffic disruptions, there are several safety concerns about passing motorists and workers in the nighttime work zone. For instance, improper lighting arrangements or excessive lighting levels at the job site could cause harmful levels of glare for the traveling public and workers, which can lead to an increased level of hazards and crashes in the vicinity of the work zone. To address the issue of glare, the current report focuses on determining and evaluating disability glare on nighttime work zones in order to develop appropriate strategies for improving the safety of workers and motorists during nighttime highway construction and maintenance projects. Disability glare is the glare that impairs our vision of objects without necessarily causing discomfort, and it can be evaluated using the veiling luminance ratio (VL ratio). In this study, disability glare values were determined by using lighting data (vertical illuminance and pavement luminance measurements) from the testing of 49 lighting arrangements. Two LED balloon lights, a metal-halide light tower, and an LED light tower were utilized for the field lighting experiments. The glare assessment analyzed the effects of the lighting system setup’s parameters, such as the mounting height, power output, rotation angle, and aiming angle of luminaires on the veiling luminance ratio values (which is a criterion for limiting disability glare). The study revealed the following key findings: (1) an increase in mounting heights of both balloon lights and light towers resulted in lower disability glare levels; (2) compared to the "perpendicular" and "away" orientations, orienting the light towers "towards" the traffic (45 degrees) significantly increases the disability glare levels of the lighting arrangement; and (3) increasing the tilt angles of portable light tower luminaries resulted in an increase in disability glare levels.

Founded with the mission to “advance the understanding, practice, and development of leadership for the benefit of society worldwide”, the Center for Creative Leadership (CCL) has served both the social and commercial sectors for over 50 years. Many of our programs across corporate, government, philanthropic, and social (e.g., NGOS, nonprofits, K12 institutions, higher education institutions, and population health organizations) sectors have the goal of improving outcomes for individual leaders and groups, and extending those outcomes to create impact at the organizational, community, or societal level. Our clients often aspire for large and transformational impact. They are interested in telling stories of impact – both immediate and sustained – that trace the power of their investment and its ability to result in improved outcomes for individuals, organizations, and communities. However, it’s often difficult or impossible to represent such impact without intentional planning and measurement. Using the idea of levers as a metaphor, we present a pathway for how leadership development across contexts can lead to larger scale impact, with examples from some of our current efforts to demonstrate this impact. We also provide a typology of stories that can be useful for communicating complex impact pathways. The typology provides metaphors for understanding the variety of layers of impact that contribute to societal change. Our work in support of this framework is continuously evolving, as we are learning, improving our measures, and identifying opportunities for increased evaluation efforts.

Polyphenol oxidases (PPOs) participate in the preparation of many plant products on the one hand and cause considerable losses during processing of plant products on the other hand. However, the physiological functions of plant PPO were still a subject of controversy at the onset of the project. Preliminary observations that suggested involvement of PPOs in resistance to herbivores and pathogens held great promise for application in agriculture but required elucidation of PPO's function if modulation of PPO expression is to be considered for improving plant protection or storage and processing of plant products. Suggestions on a possible role of PPO in various aspects of chloroplast metabolism were also relevant in this context. The characterization of plant PPO genes opened a way for achieving these goals. We reasoned that "understanding PPO targeting and routing, designing ways to manipulate its expression and assessing the effects of such modifications will enable determination of the true properties of the enzyme and open the way for controlling its activity". The objective of the project was to "obtain an insight into the function and biological significance of PPOs" by examining possible function(s) of PPO in photosynthesis and plant-pest interactions using transgenic tomato plants; extending our understanding of PPO routing and assembly and the mechanism of its thylakoid translocation; preparing recombinant PPOs for use in import studies, determination of the genuine properties of PPOs and understanding its assembly and determining the effect of PPO's absence on chloroplast performance. Results obtained during work on the project made it necessary to abandon some minor objectives and devote the effort to more promising topics. Such changes are mentioned in the 'Body of the report' which is arranged according to the objectives of the original proposal. The complex expression pattern of tomato PPO gene family was determined. Individual members of the family are differentially expressed in various parts of the plant and subjected to developmentally regulated turnover. Some members are differentially regulated also by pathogens, wounding and chemical wound signals. Wounding systemically induces PPO activity and level in potato. Only tissues that are developmentally competent to express PPO are capable of responding to the systemic wounding signal by increased accumulation of PPO mRNA. Down regulation of PPO genes causes hyper susceptibility to leaf pathogens in tomato while over expression regulation of PPO expression in tomato plants is their apparent increased tolerance to drought. Both the enhanced disease resistance conferred by PPO over expression and the increased stress tolerance due to down regulation can be used in the engineering of improved crop plants. Photosynthesis rate and variable fluorescence measurements in wild type, and PPO-null and over expressing transgenic tomato lines suggest that PPO does not enable plants to cope better with stressful high light intensities or reactive oxygen species. Rather high levels of the enzyme aggravate the damage caused under such conditions. Our work suggests that PPO's primary role is in defending plants against pathogens and herbivores. Jasmonate and ethylene, and apparently also salicylate, signals involved in responses to wounding and defense against herbivores and pathogens, enhance markedly and specifically the competence of chloroplasts to import and process pPPO. The interaction of the precursor with thylakoid membranes is primarily affected. The routing of PPO shows other unusual properties: stromal processing occurs in two sites, resulting in intermediates that are translocated across thylakoids by two different mechanisms - a DpH- and a Sec-dependent one. It is suggested that the dual pattern of processing and routing constitutes a'fail safe' mechanism, reflecting the need for a rapid and flexible response to defense challenges. Many of the observations described above should be taken into consideration when manipulation of PPO expression is contemplated for use in crop improvement.

Trichloroethylene (TCE) releases from leaks and spills next to a large government building occurred over several decades with the most recent event occurring 20 years ago. In response to a perceived conventional vapor intrusion (VI) issue a sub-slab depressurization system (SSDS) was installed 6 years ago. The SSDS is operating within design limits and has achieved building TCE vapor concentration reductions. However, subsequent periodic TCE vapor spikes based on daily HAPSITE™ measurements indicate additional source(s). Two rounds of smoke tests conducted in 2017 and 2018 involved introduction of smoke into a sanitary sewer and storm drain manholes located on effluent lines coming from the building until smoke was observed exiting system vents on the roof. Smoke testing revealed many leaks in both the storm sewer and sanitary sewer systems within the building. Sleuthing of the VI source term using a portable HAPSITE™ indicate elevated vapor TCE levels correspond with observed smoke emanation from utility lines. In some instances, smoke odors were perceived but no leak or suspect pipe was identified suggesting the odor originates from an unidentified pipe located behind or enclosed in a wall. Sleuthing activities also found building roof materials explain some of the elevated TCE levels on the 2nd floor. A relationship was found between TCE concentrations in the roof truss area, plenum space above 2nd floor offices, and breathing zone of 2nd floor offices. Installation of an external blower in the roof truss space has greatly reduced TCE levels in the plenum and office spaces. Preferential VI pathways and unexpected source terms may be overlooked mechanisms as compared to conventional VI.

Fossil fuel power plants are complex systems containing multiple components that create extreme environments for the purpose of extracting usable energy. Failures in the system can lead to increased down time for the plant, reduction of power and significant cost for repairs. In the past, inspections and maintenance of the plant's superheater tubes has been predominantly manual, laborious, and extremely time consuming. This is due to the pipe's small diameter size (between 1.3 and 7.6 cm) and the coiled structure of the tubing. In addition, the tubes are often stacked close to each other, limiting access for external inspection. Detection of pipe degradation, such as increased levels of corrosion, creep, and the formation of micro-cracks is possible using standard non-destructive evaluation (NDE) methods, including ultrasonic, radiography and electromagnetic methods. However, when the access to the sub-systems is limited or the configuration of the structure is prohibitive, alternative methods are needed for deploying the NDE tools. This research effort considers a novel robotic inspection system for the evaluation of small pipes found in typical boiler superheaters that have limited access. The pipe crawler system is an internal inspection device that can potentially navigate through the entire pipe length using linear actuators to grip the walls and inch along the pipe. The modular nature of the system allows it to traverse through straight sections and multiple 90-degree and 180-degree bends. The crawler is also capable of providing visual inspections, ultrasonic thickness measurements, and generating inner diameter surface maps using LiDAR (light detection and ranging). Ultimately, the development of this robotic inspection tool can provide information regarding the structural integrity of key pipeline components in fossil fuel power plants that are not easily accessible

Original objectives (revisions from original proposal are highlighted) 1. Elucidate the direct effects O3 and H2O2 on guard cell function, utilizing assays of stomatal response in isolated epidermal peels and whole cell gas exchange. 2. Determine the mechanistic basis of O3 and H2O2 effects on the plasma membrane through application of the electrophysiological technique of patch clamping to isolated guard cells. 3. Determine the relative sensitivity of Israeli cultivars of economically important crops to O3 and determine whether differential leaf conductance responses to O3 can explain relative sensitivity to the air pollutant: transfer of technological expertise to Israel. Background to the topic For a long time O3 has been known to reduce gas exchange in plants; it has however been unclear if O3 can affect the stomatal complex directly. Ion channels are essential in stomatal regulation, but O3 has never before been shown to affect these directly. Major conclusions, solution, achievements 1. Ozone inhibits light-induced stomatal opening in epidermal peels isolated from Vicia faba, Arabidopsis thaliana and Nicotiana tabacum in V. faba plants this leads to reduced assimilation without a direct effect on the photosynthetic apparatus. Stomatal opening is more sensitive to O3 than stomatal closure. 2. Ozone causes inhibition of inward K+ channels (involved in stomatal opening) while no detectable effect is observed o the outward K+ channels (stomatal closure). 3. Hydrogen peroxide inhibits stomatal opening and induces stomatal closure in epidermal peels isolated from Vicia faba. 4. Hydrogen peroxide enhances stomatal closure by increasing K+ efflux from guard cells via outward rectifying K+ channels. 5. Based on epidermal peel experiments we have indirectly shown that Ca2+ may play a role in the guard cell response to O3. However, direct measurement of the guard cell [Ca2+]cyt did not show a response to O3. 6. Three Israeli cultivars of zucchini, Clarita, Yarden and Bareqet, were shown to be relatively sensitive to O3 (0.12 ml1-1 ). 7. Two environmentally important Israeli pine species are adversely affected by O3, even at 0.050 ml1-1 , a level frequently exceeded under local tropospheric conditions. P. brutia may be better equipped than P. halepensis to tolerate O3 stress. 8. Ozone directly affects pigment biosynthesis in pine seedlings, as well as the metabolism of O5 precursors, thus affecting the allocation of resources among various metabolic pathways. 9. Ozone induces activity of antioxidant enzymes, and of ascorbate content i the mesophyll and epidermis cells of Commelina communis L. Implications, both scientific and agricultural We have improved the understanding of how O3 and H2O2 do affect guard cell and stomatal function. We have shown that economical important Israeli species like zucchini and pine are relatively sensitive to O3.

Research Objectives 1) Reviewing the rich economic literature on contracting and agricultural contracting; 2) Conducting a descriptive comparative study of actual contracting patterns in the U.S. and Israeli agricultural sectors; 3) Theoretical analysis of division of assets ownership, authority allocation and incentives in agricultural production contracts; 4) Theoretical analysis of strategic noncompetitive choice of agricultural production and marketing contracts, 5) Empirical studies of contracting in agricultural sectors of US and Israel, among them the broiler industry, the citrus industry and sugar beet sector. Background Recent decades have witnessed a world-wide increase in the use of agricultural contracts. In both the U.S. and Israel, contracts have become an integral part of production and marketing of many crops, fruits, vegetables and livestock commodities. The increased use of agricultural contracts raises a number of important economic policy questions regarding the optimal design of contracts and their determinants. Even though economists have made a substantial progress in understanding these issues, the theory of contracts and an empirical methodology to analyze contracts are still evolving. Moreover, there is an enormous need for empirical research of contractual relationships. Conclusions In both U.S. and Israel, contracts have become an integral part of production and marketing of many agricultural commodities. In the U.S. more than 40% of the value of agricultural production occurred under either marketing or production contracts. The use of agricultural contracts in Israel is also ubiquitous and reaches close to 60% of the value of agricultural production. In Israel we have found strategic considerations to play a dominant role in the choice of agricultural contracts and may lead to noncompetitive conduct and reduced welfare. In particular, the driving force, leading to consignment based contracts is the strategic effect. Moreover, an increase in the number of contractors will lead to changes in the terms of the contract, an increased competition and payment to farmers and economic surplus. We found that while large integrations lead to more efficient production, they also exploit local monopsonistic power. For the U.S, we have studied in more detail the choice of contract type and factors that affect contracts such as the level of informational asymmetry, the authority structure, and the available quality measurement technology. We have found that assets ownership and decision rights are complements of high-powered incentives. We have also found that the optimal allocation of decision rights, asset ownership and incentives is influenced by: variance of systemic and idiosyncratic shocks, importance (variance) of the parties’ private information, parameters of the production technology, the extent of competition in the upstream and downstream industries. Implications The primary implication of this project is that the use of agricultural production and marketing contracts is growing in both the US and Israeli agricultural sectors, while many important economic policy questions are still open and require further theoretical and empirical research. Moreover, actual contracts that are prevailing in various agricultural sectors seems to be less than optimal and, hence, additional efforts are required to transfer the huge academic know-how in this area to the practitioners. We also found evidence for exploitation of market powers by contactors in various agricultural sectors. This may call for government regulations in the anti-trust area. Another important implication of this project is that in addition to explicit contracts economic outcomes resulting from the interactions between growers and agricultural intermediaries depend on a number of other factors including allocation of decision and ownership rights and implicit contracting. We have developed models to study the interactions between explicit contracts, decision rights, ownership structure, and implicit contracts. These models have been applied to study contractual arrangements in California agriculture and the North American sugarbeet industry.

1.1 Macroeconomic summary Economic recovery has consistently outperformed the technical staff’s expectations following a steep decline in activity in the second quarter of 2020. At the same time, total and core inflation rates have fallen and remain at low levels, suggesting that a significant element of the reactivation of Colombia’s economy has been related to recovery in potential GDP. This would support the technical staff’s diagnosis of weak aggregate demand and ample excess capacity. The most recently available data on 2020 growth suggests a contraction in economic activity of 6.8%, lower than estimates from January’s Monetary Policy Report (-7.2%). High-frequency indicators suggest that economic performance was significantly more dynamic than expected in January, despite mobility restrictions and quarantine measures. This has also come amid declines in total and core inflation, the latter of which was below January projections if controlling for certain relative price changes. This suggests that the unexpected strength of recent growth contains elements of demand, and that excess capacity, while significant, could be lower than previously estimated. Nevertheless, uncertainty over the measurement of excess capacity continues to be unusually high and marked both by variations in the way different economic sectors and spending components have been affected by the pandemic, and by uneven price behavior. The size of excess capacity, and in particular the evolution of the pandemic in forthcoming quarters, constitute substantial risks to the macroeconomic forecast presented in this report. Despite the unexpected strength of the recovery, the technical staff continues to project ample excess capacity that is expected to remain on the forecast horizon, alongside core inflation that will likely remain below the target. Domestic demand remains below 2019 levels amid unusually significant uncertainty over the size of excess capacity in the economy. High national unemployment (14.6% for February 2021) reflects a loose labor market, while observed total and core inflation continue to be below 2%. Inflationary pressures from the exchange rate are expected to continue to be low, with relatively little pass-through on inflation. This would be compatible with a negative output gap. Excess productive capacity and the expectation of core inflation below the 3% target on the forecast horizon provide a basis for an expansive monetary policy posture. The technical staff’s assessment of certain shocks and their expected effects on the economy, as well as the presence of several sources of uncertainty and related assumptions about their potential macroeconomic impacts, remain a feature of this report. The coronavirus pandemic, in particular, continues to affect the public health environment, and the reopening of Colombia’s economy remains incomplete. The technical staff’s assessment is that the COVID-19 shock has affected both aggregate demand and supply, but that the impact on demand has been deeper and more persistent. Given this persistence, the central forecast accounts for a gradual tightening of the output gap in the absence of new waves of contagion, and as vaccination campaigns progress. The central forecast continues to include an expected increase of total and core inflation rates in the second quarter of 2021, alongside the lapse of the temporary price relief measures put in place in 2020. Additional COVID-19 outbreaks (of uncertain duration and intensity) represent a significant risk factor that could affect these projections. Additionally, the forecast continues to include an upward trend in sovereign risk premiums, reflected by higher levels of public debt that in the wake of the pandemic are likely to persist on the forecast horizon, even in the context of a fiscal adjustment. At the same time, the projection accounts for the shortterm effects on private domestic demand from a fiscal adjustment along the lines of the one currently being proposed by the national government. This would be compatible with a gradual recovery of private domestic demand in 2022. The size and characteristics of the fiscal adjustment that is ultimately implemented, as well as the corresponding market response, represent another source of forecast uncertainty. Newly available information offers evidence of the potential for significant changes to the macroeconomic scenario, though without altering the general diagnosis described above. The most recent data on inflation, growth, fiscal policy, and international financial conditions suggests a more dynamic economy than previously expected. However, a third wave of the pandemic has delayed the re-opening of Colombia’s economy and brought with it a deceleration in economic activity. Detailed descriptions of these considerations and subsequent changes to the macroeconomic forecast are presented below. The expected annual decline in GDP (-0.3%) in the first quarter of 2021 appears to have been less pronounced than projected in January (-4.8%). Partial closures in January to address a second wave of COVID-19 appear to have had a less significant negative impact on the economy than previously estimated. This is reflected in figures related to mobility, energy demand, industry and retail sales, foreign trade, commercial transactions from selected banks, and the national statistics agency’s (DANE) economic tracking indicator (ISE). Output is now expected to have declined annually in the first quarter by 0.3%. Private consumption likely continued to recover, registering levels somewhat above those from the previous year, while public consumption likely increased significantly. While a recovery in investment in both housing and in other buildings and structures is expected, overall investment levels in this case likely continued to be low, and gross fixed capital formation is expected to continue to show significant annual declines. Imports likely recovered to again outpace exports, though both are expected to register significant annual declines. Economic activity that outpaced projections, an increase in oil prices and other export products, and an expected increase in public spending this year account for the upward revision to the 2021 growth forecast (from 4.6% with a range between 2% and 6% in January, to 6.0% with a range between 3% and 7% in April). As a result, the output gap is expected to be smaller and to tighten more rapidly than projected in the previous report, though it is still expected to remain in negative territory on the forecast horizon. Wide forecast intervals reflect the fact that the future evolution of the COVID-19 pandemic remains a significant source of uncertainty on these projections. The delay in the recovery of economic activity as a result of the resurgence of COVID-19 in the first quarter appears to have been less significant than projected in the January report. The central forecast scenario expects this improved performance to continue in 2021 alongside increased consumer and business confidence. Low real interest rates and an active credit supply would also support this dynamic, and the overall conditions would be expected to spur a recovery in consumption and investment. Increased growth in public spending and public works based on the national government’s spending plan (Plan Financiero del Gobierno) are other factors to consider. Additionally, an expected recovery in global demand and higher projected prices for oil and coffee would further contribute to improved external revenues and would favor investment, in particular in the oil sector. Given the above, the technical staff’s 2021 growth forecast has been revised upward from 4.6% in January (range from 2% to 6%) to 6.0% in April (range from 3% to 7%). These projections account for the potential for the third wave of COVID-19 to have a larger and more persistent effect on the economy than the previous wave, while also supposing that there will not be any additional significant waves of the pandemic and that mobility restrictions will be relaxed as a result. Economic growth in 2022 is expected to be 3%, with a range between 1% and 5%. This figure would be lower than projected in the January report (3.6% with a range between 2% and 6%), due to a higher base of comparison given the upward revision to expected GDP in 2021. This forecast also takes into account the likely effects on private demand of a fiscal adjustment of the size currently being proposed by the national government, and which would come into effect in 2022. Excess in productive capacity is now expected to be lower than estimated in January but continues to be significant and affected by high levels of uncertainty, as reflected in the wide forecast intervals. The possibility of new waves of the virus (of uncertain intensity and duration) represents a significant downward risk to projected GDP growth, and is signaled by the lower limits of the ranges provided in this report. Inflation (1.51%) and inflation excluding food and regulated items (0.94%) declined in March compared to December, continuing below the 3% target. The decline in inflation in this period was below projections, explained in large part by unanticipated increases in the costs of certain foods (3.92%) and regulated items (1.52%). An increase in international food and shipping prices, increased foreign demand for beef, and specific upward pressures on perishable food supplies appear to explain a lower-than-expected deceleration in the consumer price index (CPI) for foods. An unexpected increase in regulated items prices came amid unanticipated increases in international fuel prices, on some utilities rates, and for regulated education prices. The decline in annual inflation excluding food and regulated items between December and March was in line with projections from January, though this included downward pressure from a significant reduction in telecommunications rates due to the imminent entry of a new operator. When controlling for the effects of this relative price change, inflation excluding food and regulated items exceeds levels forecast in the previous report. Within this indicator of core inflation, the CPI for goods (1.05%) accelerated due to a reversion of the effects of the VAT-free day in November, which was largely accounted for in February, and possibly by the transmission of a recent depreciation of the peso on domestic prices for certain items (electric and household appliances). For their part, services prices decelerated and showed the lowest rate of annual growth (0.89%) among the large consumer baskets in the CPI. Within the services basket, the annual change in rental prices continued to decline, while those services that continue to experience the most significant restrictions on returning to normal operations (tourism, cinemas, nightlife, etc.) continued to register significant price declines. As previously mentioned, telephone rates also fell significantly due to increased competition in the market. Total inflation is expected to continue to be affected by ample excesses in productive capacity for the remainder of 2021 and 2022, though less so than projected in January. As a result, convergence to the inflation target is now expected to be somewhat faster than estimated in the previous report, assuming the absence of significant additional outbreaks of COVID-19. The technical staff’s year-end inflation projections for 2021 and 2022 have increased, suggesting figures around 3% due largely to variation in food and regulated items prices. The projection for inflation excluding food and regulated items also increased, but remains below 3%. Price relief measures on indirect taxes implemented in 2020 are expected to lapse in the second quarter of 2021, generating a one-off effect on prices and temporarily affecting inflation excluding food and regulated items. However, indexation to low levels of past inflation, weak demand, and ample excess productive capacity are expected to keep core inflation below the target, near 2.3% at the end of 2021 (previously 2.1%). The reversion in 2021 of the effects of some price relief measures on utility rates from 2020 should lead to an increase in the CPI for regulated items in the second half of this year. Annual price changes are now expected to be higher than estimated in the January report due to an increased expected path for fuel prices and unanticipated increases in regulated education prices. The projection for the CPI for foods has increased compared to the previous report, taking into account certain factors that were not anticipated in January (a less favorable agricultural cycle, increased pressure from international prices, and transport costs). Given the above, year-end annual inflation for 2021 and 2022 is now expected to be 3% and 2.8%, respectively, which would be above projections from January (2.3% and 2,7%). For its part, expected inflation based on analyst surveys suggests year-end inflation in 2021 and 2022 of 2.8% and 3.1%, respectively. There remains significant uncertainty surrounding the inflation forecasts included in this report due to several factors: 1) the evolution of the pandemic; 2) the difficulty in evaluating the size and persistence of excess productive capacity; 3) the timing and manner in which price relief measures will lapse; and 4) the future behavior of food prices. Projected 2021 growth in foreign demand (4.4% to 5.2%) and the supposed average oil price (USD 53 to USD 61 per Brent benchmark barrel) were both revised upward. An increase in long-term international interest rates has been reflected in a depreciation of the peso and could result in relatively tighter external financial conditions for emerging market economies, including Colombia. Average growth among Colombia’s trade partners was greater than expected in the fourth quarter of 2020. This, together with a sizable fiscal stimulus approved in the United States and the onset of a massive global vaccination campaign, largely explains the projected increase in foreign demand growth in 2021. The resilience of the goods market in the face of global crisis and an expected normalization in international trade are additional factors. These considerations and the expected continuation of a gradual reduction of mobility restrictions abroad suggest that Colombia’s trade partners could grow on average by 5.2% in 2021 and around 3.4% in 2022. The improved prospects for global economic growth have led to an increase in current and expected oil prices. Production interruptions due to a heavy winter, reduced inventories, and increased supply restrictions instituted by producing countries have also contributed to the increase. Meanwhile, market forecasts and recent Federal Reserve pronouncements suggest that the benchmark interest rate in the U.S. will remain stable for the next two years. Nevertheless, a significant increase in public spending in the country has fostered expectations for greater growth and inflation, as well as increased uncertainty over the moment in which a normalization of monetary policy might begin. This has been reflected in an increase in long-term interest rates. In this context, emerging market economies in the region, including Colombia, have registered increases in sovereign risk premiums and long-term domestic interest rates, and a depreciation of local currencies against the dollar. Recent outbreaks of COVID-19 in several of these economies; limits on vaccine supply and the slow pace of immunization campaigns in some countries; a significant increase in public debt; and tensions between the United States and China, among other factors, all add to a high level of uncertainty surrounding interest rate spreads, external financing conditions, and the future performance of risk premiums. The impact that this environment could have on the exchange rate and on domestic financing conditions represent risks to the macroeconomic and monetary policy forecasts. Domestic financial conditions continue to favor recovery in economic activity. The transmission of reductions to the policy interest rate on credit rates has been significant. The banking portfolio continues to recover amid circumstances that have affected both the supply and demand for loans, and in which some credit risks have materialized. Preferential and ordinary commercial interest rates have fallen to a similar degree as the benchmark interest rate. As is generally the case, this transmission has come at a slower pace for consumer credit rates, and has been further delayed in the case of mortgage rates. Commercial credit levels stabilized above pre-pandemic levels in March, following an increase resulting from significant liquidity requirements for businesses in the second quarter of 2020. The consumer credit portfolio continued to recover and has now surpassed February 2020 levels, though overall growth in the portfolio remains low. At the same time, portfolio projections and default indicators have increased, and credit establishment earnings have come down. Despite this, credit disbursements continue to recover and solvency indicators remain well above regulatory minimums. 1.2 Monetary policy decision In its meetings in March and April the BDBR left the benchmark interest rate unchanged at 1.75%.