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In perennial ryegrass breeding programmes, dry‐matter yield (DMY) of individual plots is monitored destructively at the different cuts or derived from non‐destructive canopy height measurements using devices like rising plate meters (RPM). These approaches both have constraints. Destructive sampling implies low temporal resolution, restraining the study of dry‐matter accumulation rates, while RPM measurements are influenced by the canopy structure and limit intra‐field variability identification. We present a phenotyping methodology, based on the use of an affordable RGB camera mounted on an unmanned aerial vehicle (UAV), to monitor the spatial and temporal evolution of canopy height and to estimate DMY. Weekly flights were carried out from April to October above a field comprising a diverse set of accessions. To test the capacity of UAV imagery to estimate canopy height, 8 ground control points and 28 artificial height references were placed at different locations. Accurate flights with an RMSE as low as 0.94 cm were achieved. In addition, canopy height was recorded using an RPM and destructive biomass samples were collected. Different models (linear, multiple linear, principal components, partial least squares regression and random forest) were used to predict DMY, and their performance was evaluated. The best estimations were obtained by combining variables including canopy height, vegetation indices and environmental data in a multiple linear regression (R2 = .81). All models built using UAV data obtained a lower RMSE than the one using RPM data. The approach presented is a possibility for breeders to incorporate new information in their selection process. [ABSTRACT FROM AUTHOR]

The D0-D3 fragment of von Willebrand factor (VWF) can be divided into TIL0-E0-VWD3-C8_3-TIL3-E3 subdomains of which TIL0-E0-VWD3 comprises the main factor VIII (FVIII)-binding region. Yet, von Willebrand disease (VWD) Type 2 Normandy (2N) mutations, associated with impaired FVIII interaction, have been identified in C8_3-TIL3-E3. We now assessed the role of the VWF (sub)domains for FVIII binding using isolated D0, D3 and monomeric C-terminal subdomain truncation variants of D0-D3. Competitive binding assays and surface plasmon resonance analysis revealed that D0 requires the presence of D3 for effective interaction with FVIII. The isolated D3 domain, however, did not show any FVIII binding. Results indicated that the E3 subdomain is dispensable for FVIII binding. Subsequent deletion of the other subdomains from D3 resulted in a progressive decrease in FVIII-binding affinity. Chemical footprinting mass spectrometry suggested increased conformational changes at the N-terminal side of D3 upon subsequent subdomain deletions at the C-terminal side of the D3. A D0-D3 variant with a VWD type 2N mutation in VWD3 (D879N) or C8_3 (C1060R) also revealed conformational changes in D3, which were proportional to a decrease in FVIII-binding affinity. A D0-D3 variant with a putative VWD type 2N mutation in the E3 subdomain (C1225G) showed, however, normal binding. This implies that the designation VWD type 2N is incorrect for this variant. Results together imply that a structurally intact D3 in D0-D3 is indispensable for effective interaction between D0 and FVIII explaining why specific mutations in D3 can impair FVIII binding. [ABSTRACT FROM AUTHOR]

Centrifugal fertilizer spreaders are by far the most commonly used granular fertilizer spreader type in Europe. Their spread pattern however is error-prone, potentially leading to an undesired distribution of particles in the field and losses out of the field, which is often caused by poor calibration of the spreader for the specific fertilizer used. Due to the large environmental impact of fertilizer use, it is important to optimize the spreading process and minimize these errors. Spreader calibrations can be performed by using collection trays to determine the (field) spread pattern, but this is very time-consuming and expensive for the farmer and hence not common practice. Therefore, we developed an innovative multi-camera system to predict the spread pattern in a fast and accurate way, independent of the spreader configuration. Using high-speed stereovision, ejection parameters of particles leaving the spreader vanes were determined relative to a coordinate system associated with the spreader. The landing positions and subsequent spread patterns were determined using a ballistic model incorporating the effect of tractor motion and wind. Experiments were conducted with a commercial spreader and showed a high repeatability. The results were transformed to one spatial dimension to enable comparison with transverse spread patterns determined in the field and showed similar results. [ABSTRACT FROM AUTHOR]

Better characterization of the fertilizer spreading process, especially the fertilizer pattern distribution on the ground, requires an accurate measurement of individual particle properties and dynamics. Both 2D and 3D high speed imaging techniques have been developed for this purpose. To maximize the accuracy of the predictions, a specific illumination level is required. This paper describes the development of a high irradiance LED system for high speed motion estimation of fertilizer particles. A spectral sensitivity factor was used to select the optimal LED in relation to the used camera from a range of commercially available high power LEDs. A multiple objective genetic algorithm was used to find the optimal configuration of LEDs resulting in the most homogeneous irradiance in the target area. Simulations were carried out for different lenses and number of LEDs. The chosen configuration resulted in an average irradiance level of 452 W/m2 with coefficient of variation less than 2%. The algorithm proved superior and more flexible to other approaches reported in the literature and can be used for various other applications. [ABSTRACT FROM AUTHOR]

Tandem mass tags (TMTs) were utilized in a novel chemical footprinting approach to identify lysine residues that mediate the interaction of receptor-associated protein (RAP) with cluster II of LDL (low-density lipoprotein) receptor (LDLR)-related protein (LRP). The isolated RAP D3 domain was modified with TMT- 126 and the D3 domain-cluster II complex with TMT-127. Nano- LC-MS analysis revealed reduced modification with TMT-127 of peptides including Lys256, Lys270 and Lys305-Lys306 suggesting that these residues contribute to cluster II binding. This agrees with previous findings that Lys256 and Lys270 are critical for binding cluster II sub-domains [Fisher, Beglova and Blacklow (2006) Mol. Cell 22, 277-283]. Cluster II-binding studies utilizing D3 domain variants K256A, K305A and K306A now showed that Lys306 contributes to cluster II binding as well. For full-length RAP, we observed that peptides including Lys60, Lys191, Lys256, Lys270 and Lys305-Lys306 exhibited reduced modification with TMT in the RAP-cluster II complex. Notably, Lys60 has previously been implicated to mediate D1 domain interaction with cluster II. Our results suggest that also Lys191 of the D2 domain contributes to cluster II binding. Binding studies employing the RAP variants K191A, K256A, K305A and K306A, however, revealed a modest reduction in cluster II binding for the K256A variant only. This suggests that the other lysine residues can compensate for the absence of a single lysine residue for effective complex assembly. Collectively, novel insight has been obtained into the contribution of lysine residues of RAP to cluster II binding. In addition, we propose that TMTs can be utilized to identify lysine residues critical for protein complex formation. [ABSTRACT FROM AUTHOR]

A 3D imaging technique using a high speed binocular stereovision system was developed in combination with corresponding image processing algorithms for accurate determination of the parameters of particles leaving the spinning disks of centrifugal fertilizer spreaders. Validation of the stereo-matching algorithm using a virtual 3D stereovision simulator indicated an error of less than 2 pixels for 90% of the particles. The setup was validated using the cylindrical spread pattern of an experimental spreader. A 2D correlation coefficient of 90% and a Relative Error of 27% was found between the experimental results and the (simulated) spread pattern obtained with the developed setup. In combination with a ballistic flight model, the developed image acquisition and processing algorithms can enable fast determination and evaluation of the spread pattern which can be used as a tool for spreader design and precise machine calibration. [ABSTRACT FROM AUTHOR]

Background/Aims: Diarrhea-associated hemolytic uremic syndrome is associated with the presence of Shiga toxin (Stx1, Stx2 and several variants) in the circulation. The aim of this study is to examine the possible triggering effect of Stx1 on the exocytosis of Weibel-Palade bodies (WPbs). Methods: Cultured human umbilical venous endothelial cells (HUVECs) and glomerular microvascular endothelial cells (GMVECs) were stimulated by thrombin and Stx1 in both static and flowing conditions. The amount of secreted von Willebrand factor (VWF) in the supernatant as well as the remaining intracellular fraction was determined. Results: In HUVECs and in 2 out of 4 GMVECs, the stimulation of Stx1 in flow at 1 dyne/cm2 resulted in a decrease of intracellular VWF. This is contrary to the results of Stx1 applied in static conditions. At a higher flow rate of 5 dyne/cm2, no effect in GMVECs was observed. Conclusion: Stx1 can contribute, via an effect on WPbs, to the exocytosis of WPbs in flow conditions in HUVECs and probably in GMVECs. This results in the release of VWF, suggesting an initiating role of the coagulation system in the pathogenesis. © 2014 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

ABSTRACT BACKGROUND Multimodality imaging such as proton magnetic resonance spectroscopy (MRS) and positron emission tomography (PET) have provided information specific to the underlying mechanisms of many brain diseases, including multiple sclerosis (MS). PURPOSE To determine the structural and metabolic characterization of two particular variants of MS, namely tumefactive MS and Balo's concentric sclerosis (BCS). METHODS Conventional MR imaging, diffusion and perfusion MR, MR spectroscopy and PET imaging with F-18 fluorodeoxyglucose (FDG) and F-18 fluoromethylcholine (FCho) were performed. RESULTS In a case with pathologically proven tumefactive MS, magnetic resonance imaging (MRI) showed a pseudotumoral lesion with incomplete ring enhancement, peripheral diffusion restriction, and high choline and lactate peaks on MRS. On follow-up, the lesion showed significant growth. In a case of BCS, MRI showed an onion-like lesion without contrast enhancement or diffusion restriction, and only a moderate increase in choline on MRS. The lesion remained stable on follow-up. On PET, there was no uptake of F-18 FDG in either type of MS lesion. Conversely, uptake of F-18 FCho was moderate in tumefactive MS, whereas no F-18 FCho uptake was noted in the lesion with, on MRI, typical features of BCS. CONCLUSIONS Our findings illustrate that metabolic features may differ between variants of MS possibly signifying different disease activity. [ABSTRACT FROM AUTHOR]

Wideband receiver (RX) and transmitter (TX) RF front-ends for wireless universal radio applications are presented. The RX is comprised of a two-stage low-noise amplifier (LNA) applying feedback and shunt peaking, a combiner buffer for performance boosting, and an inverter-based in-phase/quadrature (IQ) down-conversion mixer. The wideband LNA provides input matching of better than -\ 10 dB from dc to beyond 10 GHz. The conversion gain (CG) of the RX front-end has a peak value of 31 dB with a 3-dB bandwidth up to 9 GHz. The minimal noise figure is 6 dB and kept below 9 dB within the entire operational bandwidth. The RX has a linearity in terms of intermodulation distortion of better than -\12 dBm. The direct conversion TX involving inverter-based IQ modulator and Darlington-type pre-power amplifier features operation up to 9 GHz with 10-dB mean CG and an average output power of 4 dBm at 1-dB compression level. Excluding buffers and local oscillator generation, the RX and TX dissipate 54 and 84 mW, respectively, from a 1.2-V voltage supply. The circuit prototypes have been fabricated in a standard 65-nm CMOS low-power process without any additional RF options and occupy an area of only 0.77 \ mm^2 and 0.53 \ mm^2, respectively. [ABSTRACT FROM PUBLISHER]

As apoptosis occurs over an interval of time after administration of apoptosis-inducing therapy in tumors, the changes in technetium 99m (99mTc)-tricarbonyl (CO)3 His-annexin A5 (His-ann A5) accumulation over time were examined. Colo205-bearing mice were divided into six treatment groups: (1) control, (2) 5-fluorouracil (5-FU; 250 mg/kg), (3) irinotecan (100 mg/kg), (4) oxaliplatin (30 mg/kg), (5) bevacizumab (5 mg/kg), and (6) panitumumab (6 mg/kg). 99mTc-(CO)3 His-ann A5 was injected 4, 8, 12, 24, and 48 hours posttreatment, and micro--single-photon emission computed tomography was performed. Immunostaining of caspase-3 (apoptosis), survivin (antiapoptosis), and LC3-II (autophagy marker) was also performed. Different dynamics of 99mTc-(CO)3 His-ann A5 uptake were observed in this colorectal cancer xenograft model, in response to a single dose of three different chemotherapeutics (5-FU, irinotecan, and oxaliplatin). Bevacizumab-treated mice showed no increased uptake of the radiotracer, and a peak of 99mTc-(CO)3 His-ann A5 uptake in panitumumab-treated mice was observed 24 hours posttreatment, as confirmed by caspase-3 immunostaining. For irinotecan-, oxaliplatin-, and bevacizumab-treated tumors, a significant correlation was established between the radiotracer uptake and caspase-3 immunostaining (r = .8, p < .05; r = .9, p < .001; r = .9, p < .001, respectively). For 5-FU- and panitumumab-treated mice, the correlation coefficients were r = .7 (p = .18) and r = .7 (p = .19), respectively. Optimal timing of annexin A5 imaging after the start of different treatments in the Colo205 model was determined. [ABSTRACT FROM AUTHOR]

Background: Point mutations resulting in reduced factor VIII (FVIII) binding to von Willebrand factor (VWF) are an important cause of mild/moderate hemophilia A. Treatment includes desmopressin infusion, which concomitantly increases VWF and FVIII plasma levels, apparently from storage pools containing both proteins. The source of these VWF/FVIII co-storage pools and the mechanism of granule biogenesis are not fully understood. Methodology/Principal Findings: We studied intracellular trafficking of FVIII variants implicated in mild/moderate hemophilia A together with VWF in HEK293 cells and primary endothelial cells. The role of VWF binding was addressed using FVIII variants displaying reduced VWF interaction. Binding studies using purified FVIII proteins revealed moderate (Arg2150His, Del2201, Pro2300Ser) to severe (Tyr1680Phe, Ser2119Tyr) VWF binding defects. Expression studies in HEK293 cells and primary endothelial cells revealed that all FVIII variants were present within VWF-containing organelles. Quantitative studies showed that the relative amount of FVIII storage was independent of various mutations. Substantial amounts of FVIII variants are co-stored in VWF-containing storage organelles, presumably by virtue of their ability to interact with VWF at low pH. Conclusions: Our data suggest that the potential of FVIII co-storage with VWF is not affected in mild/moderate hemophilia A caused by reduced FVIII/VWF interaction in the circulation. These data support the hypothesis that Weibel-Palade bodies comprise the desmopressin-releasable FVIII storage pool in vivo. [ABSTRACT FROM AUTHOR]

Purpose To give an up-to-date overview of the potential clinical utility of 18F-labelled choline derivatives for tumour imaging with positron emission tomography. Methods A PubMed search for 18F-labelled choline analogues was performed. Review articles and reference lists were used to supplement the search findings. Results 18F-labelled choline analogues have been investigated as oncological PET probes for many types of cancer on the basis of enhanced cell proliferation. To date, studies have focused on the evaluation of prostate cancer. Available studies have provided preliminary results for detecting local and metastatic disease. Experience with 18F-fluorocholine PET in other tumour types, including brain and liver tumours, is still limited. In the brain, excellent discrimination between tumour and normal tissue can be achieved due to the low physiological uptake of 18F-fluorocholine. In the liver, in which there is a moderate to high degree of physiological uptake in normal tissue, malignancy discrimination may be more challenging. Conclusion PET/CT with 18F-fluorocholine can be used to detect (recurrent) local prostate cancer, but seems to have limited value for T (tumour) and N (nodal) staging. In patients presenting with recurrent biochemical prostate cancer, it is a suitable single-step examination with the ability to exclude distant metastases when local salvage treatment is intended. In the brain, high-grade gliomas, metastases and benign lesions can be distinguished on the basis of 18F-fluorocholine uptake. Moreover, PET imaging is able to differentiate between radiation-induced injury and tumour recurrence. In the liver, 18F-fluorocholine PET/CT seems promising for the detection of hepatocellular carcinoma. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate whether normoglycemic glucose concentrations interfere with cerebral F-18 FDG uptake. The analysis was based on 2 sets of paired PET scans in 94 patients who were in complete metabolic remission after the successful completion of treatment for lymphoma. For these 188 PET scans, 2 subgroups were defined according to the plasma glucose level at the time of scanning. Group 1 contained the PET images that were associated with the lower of both normoglycemic plasma glucose levels, whereas group 2 contained the PET images that were associated with the higher of both plasma glucose levels. SUVs (standard uptake values) in the cerebellum between both groups were compared using paired sample T test. Subsequently, SUVs were normalized to a standard glucose concentration and normalized SUVs were again compared. Further, we calculated the coefficient of variation of SUVs in group 1 and 2 both before and after the normalization step. Mean plasma glucose level was 86 mg/dL (SD of 9 mg/dL) in group 1 and 97 mg/dL (SD of 10 mg/dL) in group 2. Mean SUV was 3.8 (SD of 1.1) for group 1 and 3.5 (SD of 1.1) for group 2. Mean SUV in group 1 was slightly but statistically significantly higher than the mean SUV in group 2 ( p < 0.01). Mean normalized SUV was 3.6 (SD of 1.1) in group 1 and 3.7 (SD of 1.3) in group 2. A paired comparison between normalized SUVs in both groups indicated that there was no statistically significant difference ( p < 0.31). The coefficient of variation for the SUVs in group 1 and 2 before normalization was 29 and 30%, respectively. The coefficient of variation for the normalized SUVs in group 1 and 2 was 30 and 34%, respectively. Our results indicated that plasma glucose levels that are within the normoglycemic range have a small but systematic effect on F-18 FDG uptake in the brain (following an inverse relationship). Normalizing plasma glucose levels to a standard glucose concentration successfully reduced the intra-subject variability of SUV measures. Inter-subject variability, however, remained high suggesting that other factors have an influence as well. [ABSTRACT FROM AUTHOR]

Background: The increasing incidence of hepatocellular carcinoma in Western countries has led to an expanding interest of scientific research in this field. Therefore, a vast need of experimental models that mimic the natural pathogenesis of hepatocellular carcinoma (HCC) in a short time period is present. The goal of our study was (1) to develop an efficient mouse model for HCC research, in which tumours develop in a natural background of fibrosis and (2) to assess the time-dependent angiogenic changes in the pathogenesis of HCC. Methods: Weekly intraperitoneal injections with the hepatocarcinogenic compound N-nitrosodiethylamine was applied as induction method and samples were taken at several time points to assess the angiogenic changes during the progression of HCC. Results: The N-nitrosodiethylamine-induced mouse model provides well vascularised orthotopic tumours after 25 weeks. It is a representative model for human HCC and can serve as an excellent platform for the development of new therapeutic targets. [ABSTRACT FROM AUTHOR]

A WiMediaI/MBOA compliant RF transceiver for ultra-wideband data communication in the 3-5-GHz band is presented. The transceiver includes receiver, transmitter and synthesizer is completely integrated in 0.13-µm standard CMOS technology. The receiver uses a feedback-based low-noise amplifier (LNA) to obtain an RF gain of 4 to 37 dB and an overall measured noise figure of 3.6 to 4.1 dB over the 3-5-GHz band of interest. The transmitter supports an error vector magnitude (EVM) of -28 dB up to -4 dBm output power and meets the FCC and WiMedia mask specifications. The power consumption from a single supply voltage of 1.5 V is 237 mW for the receiver and 284 mW for the transmitter, both including the synthesizer. [ABSTRACT FROM AUTHOR]

A fully integrated 0.25 μm CMOS bluetooth class 1 power amplifier is presented. On this chip all inductors and decoupling capacitors are situated on the silicon die. Due to the high level of integration, a cheap flip chip assembly method has been used. The chip delivers 138 mW (21.4 dBm) of output power with a power added efficiency of 25.8%. When the amplifier is tuned to its optimum frequency of 2.1 GHz, the output power increases to 184 mW and the power added efficiency increases to 29.5%. To compare the performance of this realisation with other recently published PA, a figure of merit for saturated (switched) power amplifiers is introduced. [ABSTRACT FROM AUTHOR]

Low-density lipoprotein receptor-related protein (LRP) contributes to factor VIII (FVIII) catabolism in vivo. Besides LRP, FVIII also interacts with very low-density lipoprotein receptor (VLDLR) in vitro. We investigated the physiological role of VLDLR in FVIII catabolism, using knockout mouse models for VLDLR and LRP, alone and in combination. VLDLR−/− mice displayed normal plasma FVIII, whereas VLDLR−/− LRP− double-knockout mice had slightly increased FVIII compared with LRP-deficient mice. Remarkably, VLDLR deficiency slightly accelerated FVIII clearance. Adenovirus-mediated overexpression of VLDLR did not lower plasma FVIII in LRP-deficient mice. We conclude that VLDLR does not act in concert with LRP in FVIII clearance in vivo. [ABSTRACT FROM AUTHOR]

Develops a state-space behavioral model for complementary metal oxide semiconductors class E power amplifiers. Design of amplifiers; Use of state-space equations; Derivation of the power balance of the power amplifier; Design of switched power amplifiers.

Presents the use of Complementary Metal Oxide Semiconductors (CMOS) for integration of a Radio Frequency (RF) transceiver front-end. Attempts of producing single-chip CMOS RF circuits for cellular applications; Discussion of fundamental pitfalls and limitations of RF CMOS; Emphasis on optimizing transceiver as a single block.

The functional defect caused by substitution of Arg527 (→ Trp) and Arg531 (→ Gly, His) in factor VIII (FVIII), was explored by employing FVIII derived from patient plasma and recombinant FVIII variants. Mutation of these residues is associated with mild haemophilia A. For both FVIII-R527W and FVIII-R531H, activity was lower than antigen, indicating a functional defect for both variants. In contrast to FVIII-R527W, the amount of FVIII-R531H heterodimer present in plasma was reduced compared to heavy and light chain levels. Factor X (FX) activation experiments employing recombinant FVIII-R531G revealed that the activated FVIII-R531G heterotrimer was less stable than normal FVIIIa, apparently due to rapid dissociation of the A2 domain. These findings suggest that Arg531 is involved in maintaining the stability of both the heterodimer and the activated FVIII heterotrimer. Recombinant FVIII-R527W displayed reduced stimulation of FX activation, suggesting a defect in interaction with factor IXa (FIXa). The contribution of Arg527 in the interaction with FIXa was supported by the observation that FVIII-derived synthetic peptide Tyr511-Leu530 was able to inhibit FX activation and that this inhibition could be overcome by addition of increasing concentrations of FIXa. Furthermore, in the three-dimensional FVIII model residues Val517-Arg527 are located near the FIXa binding site Ser558-Gln565. Therefore we propose that Arg527 is part of an extended FIXa binding site, comprising residues Ser558-Gln565 and Val517-Arg527. [ABSTRACT FROM AUTHOR]

Activation and limited proteolysis of factor VIII have been investigated with respect to the role of the heavy-chain region LysT13-Arg740. The kinetics of factor VIII activation have been analyzed in a system consisting of human factor VIII, factor IXa, factor X, phospholipids, and thrombin or factor Xa. Plasma-derived factor VIII is activated by thrombin with a second-order rate constant of 3.3±0.3×106 M-1 s-1, which proved to be slightly higher than for activation by factor Xa. The second-order rate constant of activation by thrombin of plasma-derived factor VIII in the presence of a monoclonal antibody against the sequence Lys713-Arg740 is markedly reduced. The same result was obtained for activation by thrombin and factor Xa of factor VIII with a deletion including the sequence Lys713-Arg740, des-(713–1637) factor VIII. This suggests that the region Lys713-Arg740 promotes factor VIII activation by both thrombin and factor Xa. Since factor VIII activation is associated with proteolysis, cleavage of factor VIII heavy and light chains was analyzed quantitatively. These studies indicated that heavy-chain cleavage of des-(713–1637)-factor VIII is similar to that of plasma-derived factor VIII. In contrast, cleavage of the light chain of des-(713–1637)-factor VIII is clearly reduced. Furthermore, the second-order rate constant (0.2±0.1×106 M-1 s-1) of des-(713–1637)-factor VIII light-chain cleavage by thrombin was reduced tenfold compared with that of plasma-derived factor VIII. Proteolysis by factor Xa yielded similar results. The rate of des-(713–1637)-factor VIII light chain cleavage by thrombin is similar to that of isolated light-chain, but isolated light-chain is cleaved by factor Xa 20-fold more efficiently than the light chain in des (713–1637)-factor VIII. We conclude that activation of factor VIII by both thrombin and factor Xa is closely associated with light-chain cleavage. Furthermore, within the factor VIII heterodimer, the heavy-chain sequence Lys713-Arg740 promotes both activation and light-chain proteolysis. [ABSTRACT FROM AUTHOR]

Perennial ryegrass (Lolium perenne) is a perennial crop used in temperate regions as forage. In L. perenne breeding programs, persistency is an important trait. Poor persistency results in sward degradation and associated yield and nutritive value losses. Breeders assess persistency of accessions using visual scoring in field plots during the 2nd or 3rd growing season. This evaluation system is easy and cheap but is not free from human bias. In this study, the correlation between the scoring done by different breeders was only 0.243. As an alternative we have developed a methodology to assess persistency of L. perenne breeding materials based on vegetation indices (VIs) derived from Unmanned Aerial Vehicle (UAV) imagery. The VIs Excess green (ExG2), Green Leaf Index and Normalized green intensity (GCC) were found to provide consistent results for flights carried out under different light conditions and were validated by ground reference information. The correlation between the VIs and the percentage of ground cover extracted from on-ground imagery was 0.885. To test the implementation of the method we compared the ExG2 value based approach to selection with a visual score based selection methodology as applied by two breeders. The breeding decisions of Breeder A agreed well with decisions based on ExG2 values (74.6%), but those of Breeder B displayed a lower agreement (54.0%). In contrast, agreement between decisions based on different flights was very high (91.6%). The methodology was validated for general applicability. In summary, the results demonstrate that basing persistency selection in L. perenne breeding programs on ExG2 values from UAV imagery is likely to be more objective in comparison to the currently-used visual scoring method. [ABSTRACT FROM AUTHOR]