Global Wheat Head Detection (GWHD) dataset: a large and diverse dataset of high resolution RGB labelled images to develop and benchmark wheat head detection methods

Detection of wheat heads is an important task allowing to estimate pertinent traits including head population density and head characteristics such as sanitary state, size, maturity stage and the presence of awns. Several studies developed methods for wheat head detection from high-resolution RGB imagery. They are based on computer vision and machine learning and are generally calibrated and validated on limited datasets. However, variability in observational conditions, genotypic differences, development stages, head orientation represents a challenge in computer vision. Further, possible blurring due to motion or wind and overlap between heads for dense populations make this task even more complex. Through a joint international collaborative effort, we have built a large, diverse and well-labelled dataset, the Global Wheat Head detection (GWHD) dataset. It contains 4,700 high-resolution RGB images and 190,000 labelled wheat heads collected from several countries around the world at different growth stages with a wide range of genotypes. Guidelines for image acquisition, associating minimum metadata to respect FAIR principles and consistent head labelling methods are proposed when developing new head detection datasets. The GWHD is publicly available at http://www.global-wheat.com/ and aimed at developing and benchmarking methods for wheat head detection.Comment: 16 pages, 7 figures, Dataset pape

First Observation of Self-Amplified Spontaneous Emission in a Free-Electron Laser at 109 nm Wavelength

We present the first observation of Self-Amplified Spontaneous Emission (SASE) in a free-electron laser (FEL) in the Vacuum Ultraviolet regime at 109 nm wavelength (11 eV). The observed free-electron laser gain (approx. 3000) and the radiation characteristics, such as dependency on bunch charge, angular distribution, spectral width and intensity fluctuations all corroborate the existing models for SASE FELs.Comment: 6 pages including 6 figures; e-mail: [email protected]

Satellite-supported flood forecasting in river networks: a real case study

Satellite-based (e.g., Synthetic Aperture Radar [SAR]) water level observations (WLOs) of the floodplain can be sequentially assimilated into a hydrodynamic model to decrease forecast uncertainty. This has the potential to keep the forecast on track, so providing an Earth Observation (EO) based flood forecast system. However, the operational applicability of such a system for floods developed over river networks requires further testing. One of the promising techniques for assimilation in this field is the family of ensemble Kalman (EnKF) filters. These filters use a limited-size ensemble representation of the forecast error covariance matrix. This representation tends to develop spurious correlations as the forecast-assimilation cycle proceeds, which is a further complication for dealing with floods in either urban areas or river junctions in rural environments. Here we evaluate the assimilation of WLOs obtained from a sequence of real SAR overpasses (the X-band COSMO-Skymed constellation) in a case study. We show that a direct application of a global Ensemble Transform Kalman Filter (ETKF) suffers from filter divergence caused by spurious correlations. However, a spatially-based filter localization provides a substantial moderation in the development of the forecast error covariance matrix, directly improving the forecast and also making it possible to further benefit from a simultaneous online inflow error estimation and correction. Additionally, we propose and evaluate a novel along-network metric for filter localization, which is physically-meaningful for the flood over a network problem. Using this metric, we further evaluate the simultaneous estimation of channel friction and spatially-variable channel bathymetry, for which the filter seems able to converge simultaneously to sensible values. Results also indicate that friction is a second order effect in flood inundation models applied to gradually varied flow in large rivers. The study is not conclusive regarding whether in an operational situation the simultaneous estimation of friction and bathymetry helps the current forecast. Overall, the results indicate the feasibility of stand-alone EO-based operational flood forecasting

The effect of enteral and parenteral feeding on secretion of orexigenic peptides in infants

<p>Abstract</p> <p>Background</p> <p>The feeding in the first months of the life seems to influence the risks of obesity and affinity to some diseases including atherosclerosis. The mechanisms of these relations are unknown, however, the modification of hormonal action can likely be taken into account. Therefore, in this study the levels of ghrelin and orexin A - peripheral and central peptide from the orexigenic gut-brain axis were determined.</p> <p>Methods</p> <p>Fasting and one hour after the meal plasma concentrations of ghrelin and orexin were measured in breast-fed (group I; n = 17), milk formula-fed (group II; n = 16) and highly hydrolyzed, hypoallergic formula-fed (group III; n = 14) groups, age matched infants (mean 4 months) as well as in children with iv provision of nutrients (glucose - group IV; n = 15; total parenteral nutrition - group V; n = 14). Peptides were determined using EIA commercial kits.</p> <p>Results</p> <p>Despite the similar caloric intake in orally fed children the fasting ghrelin and orexin levels were significantly lower in the breast-fed children (0.37 ± 0.17 and 1.24 ± 0.29 ng/ml, respectively) than in the remaining groups (0.5 ± 0.27 and 1.64 ± 0.52 ng/ml, respectively in group II and 0.77 ± 0.27 and 2.04 ± 1.1 ng/ml, respectively, in group III). The postprandial concentrations of ghrelin increased to 0.87 ± 0.29 ng/ml, p < 0.002 and 0.76 ± 0.26 ng/ml, p < 0.01 in groups I and II, respectively as compared to fasting values. The decrease in concentration of ghrelin after the meal was observed only in group III (0.47 ± 0.24 ng/ml). The feeding did not influence the orexin concentration. In groups IV and V the ghrelin and orexin levels resembled those in milk formula-fed children.</p> <p>Conclusion</p> <p>The highly hydrolyzed diet strongly affects fasting and postprandial ghrelin and orexin plasma concentrations with possible negative effect on short- and long-time effects on development. Also total parenteral nutrition with the continuous stimulation and lack of fasting/postprandial modulation might be responsible for disturbed development in children fed this way.</p

Increased 5-HT3-mediated signalling in pelvic afferent neurons from mice deficient in P2X2 and/or P2X3 receptor subunits

Extracellular ATP and 5-hydroxytryptamine (5-HT) are both involved in visceral sensory pathways by interacting with P2X and 5-HT3 receptors, respectively. We have investigated the changes in P2X and 5-HT3-mediated signalling in pelvic afferent neurons in mice deficient in P2X2 and/or P2X3 subunits by whole-cell recording of L6–S2 dorsal root ganglion (DRG) neurons and by multi-unit recording of pelvic afferents of the colorectum. In wildtype DRG neurons, ATP evoked transient, sustained or mixed (biphasic) inward currents. Transient currents were absent in P2X3−/− neurons, whereas sustained currents were absent in P2X2−/− DRG neurons. Neither transient nor sustained currents were observed following application of ATP or α,β-methylene ATP (α,β-meATP) in P2X2/P2X3Dbl−/− DRG neurons. 5-HT was found to induce a fast inward current in 63% of DRG neurons from wildtype mice, which was blocked by tropisetron, a 5-HT3 receptor antagonist. The percentage of DRG neurons responding to 5-HT was significantly increased in P2X 2−/−, P2X3−/− and P2X2/P2X3Dbl−/− mice, and the amplitude of 5-HT response was significantly increased in P2X2/P2X3Dbl−/− mice. The pelvic afferent response to colorectal distension was attenuated in P2X2/P2X3Dbl−/− mice, but the response to serosal application of 5-HT was enhanced. Furthermore, tropisetron resulted in a greater reduction in pelvic afferent responses to colorectal distension in the P2X2/P2X3Dbl−/− preparations. These data suggest that P2X receptors containing the P2X2 and/or P2X3 subunits mediate purinergic activation of colorectal afferents and that 5-HT signalling in pelvic afferent neurons is up-regulated in mice lacking P2X2 or P2X3 receptor genes. This effect is more pronounced when both subunits are absent

Methane emission by Camelids

Methane emissions from ruminant livestock have been intensively studied in order to reduce contribution to the greenhouse effect. Ruminants were found to produce more enteric methane than other mammalian herbivores. As camelids share some features of their digestive anatomy and physiology with ruminants, it has been proposed that they produce similar amounts of methane per unit of body mass. This is of special relevance for countrywide greenhouse gas budgets of countries that harbor large populations of camelids like Australia. However, hardly any quantitative methane emission measurements have been performed in camelids. In order to fill this gap, we carried out respiration chamber measurements with three camelid species (Vicugna pacos, Lama glama, Camelus bactrianus; n = 16 in total), all kept on a diet consisting of food produced from alfalfa only. The camelids produced less methane expressed on the basis of body mass (0.3260.11 L kg21 d21) when compared to literature data on domestic ruminants fed on roughage diets (0.5860.16 L kg21 d21). However, there was no significant difference between the two suborders when methane emission was expressed on the basis of digestible neutral detergent fiber intake (92.7633.9 L kg21 in camelids vs. 86.2612.1 L kg21 in ruminants). This implies that the pathways of methanogenesis forming part of the microbial digestion of fiber in the foregut are similar between the groups, and that the lower methane emission of camelids can be explained by their generally lower relative food intake. Our results suggest that the methane emission of Australia’s feral camels corresponds only to 1 to 2% of the methane amount produced by the countries’ domestic ruminants and that calculations of greenhouse gas budgets of countries with large camelid populations based on equations developed for ruminants are generally overestimating the actual levels