Predicting Key Grassland Characteristics from Hyperspectral Data

A series of experiments were conducted to measure and quantify the yield, dry matter content, sugars content, and nitrates content of grass intended for ensilement. These experiments took place in the East Midlands of Ireland during the Spring, Summer, and Autumn of 2019. A bespoke sensor rig was constructed; included in this rig was a hyperspectral radiometer that measured a broad spectrum of reflected natural light from a circular spot approximately 1.2 m in area. Grass inside a 50 cm square quadrat was manually collected from the centre of the circular spot for ground truth estimation of the grass qualities. Up to 25 spots were recorded and sampled each day. The radiometer readings for each spot were automatically recorded onto a laptop that controlled the sensor rig, and ground truth measurements were made either on-site or within 24 h in a wet chemistry laboratory. The collected data was used to build Partial Least Squares Regression (PLSR) predictive models of grass qualities from the hyperspectral dataset, and it was found that substantial relationships exist between the spectral reflectance from the grass and yield (r2 = 0.62), dry matter % (r2 = 0.54), sugar content (r2 = 0.54) and nitrates (r2 = 0.50). This shows that hyperspectral reflectance data contains substantial information about key grass qualities and can form part of a broader holistic data-driven approach to provide accurate and rapid predictions to farmers, agronomists, and agricultural contractors.

Predicting Key Grassland Characteristics from Hyperspectral Data

A series of experiments were conducted to measure and quantify the yield, dry matter content, sugars content and nitrates content of grass intended for ensilement. These experiments took place in the East Midlands of Ireland during the Spring, Summer and Autumn of 2019. A bespoke sensor rig was constructed; included in this rig was a hyperspectral radiometer that measured a broad spectrum of reflected natural light from a circular spot approximately 1.2 metres in area. Grass inside a 50cm square quadrat was manually collected from the centre of the circular spot for ground truth estimation of the grass qualities. Up to 25 spots were recorded and sampled each day. The radiometer readings for each spot were automatically recorded onto a laptop that controlled the sensor rig, and ground truth measurements were made either on site or within 24 hours in a wet chemistry laboratory. The collected data was used to build Partial Least Squares Regression (PLSR) predictive models of grass qualities from the hyperspectral dataset and it was found that substantial relationships exist between the spectral reflectance from the grass and yield (r2 = 0.62), dry matter % (r2 = 0.54), sugar content (r2 = 0.54) and nitrates (r2 = 0.50). This shows that hyperspectral reflectance data contains substantial information about key grass qualities and can form part of a broader holistic data driven approach to provide accurate and rapid predictions to farmers, agronomists and agricultural contractors.

Immature stages of Murgantia histrionica (Hemiptera: Pentatomidae)

Immature stages of Murgantia histrionica (Hemiptera: Pentatomidae) are described using light and scanning electron microscopy. Specimens of all life stages of M. histrionica were collected on Peritoma arborea (Cleomaceae) in Palm Springs, California. Specimens were observed in light and scanning microscopies, imagens taken and described based on specimens and photographs. We provide images of the eggs and immatures in light microscopy, and SEM of the eggs and first and fifth instars. Eggs of M. histrionica are barrel-shaped, white, with brown band and circular spot; the corium surface carinated, forming hexagonal cells; carinae irregular apically. The nymphal color pattern; the reflexed lateral margins of pro- and mesothorax; and the scattered punctuation of the tegument are a combination of characteristics enabling M. histrionica identification in its nymphal stages. The eggs of M. histrionica are similar in shape, color, and size to other Strachiini genera, such as Bagrada, Eurydema and Stenozygum. Among the Strachiini, the correct identification of M. histrionica based on immatures is possible by the shape of the head and pronotum, overall size of immatures, and coloration patterns.

Subnicho etario y aspectos de la biología reproductiva de Parachondria neglectus (Littorinimorpha: Annulariidae) en Manzanillo, Cuba

In the present research, the temporal dynamics of age-related subniche and some aspects of the reproductive biology of a Parachondria neglectus population, located in Manzanillo-Granma-Cuba, were characterized. Thirty expeditions were performed from December 2013 to February 2015. The comparisons between the length (t = 8.05, P = 0.007) and biggest diameter (t = 6.24, P = 0.0001) of the shells of truncated juveniles and the shells of full juveniles showed significant statistical differences, indicating that both groups represent two kinds of different ages. The comparison between the biggest diameter of the shells of truncated adults and the shells of full adults (t = 1.50, P = 0.16) showed that both groups represent the same kind of age in the population. The existence of significant statistical differences between the length (t = 19.45, P = 0.0003) and the biggest diameter (t = 13.19, P = 0.006) of the females’ shells and the males’ shells verify the sexual dimorphism in the species, proving to be the females of bigger dimensions in relation to the males. The whitish circular spot in the shells is a valid external morphological characteristic to differentiate the adult females already mated in previous occasions from the rest of the members of the population. The reproductive period was from July to December 2014. Copulations were observed from July to October 2014 and they were associated to conditions of abundant precipitations and high temperatures of summer. The recruitment period took place from September to December 2014.

High-Speed Fabrication of Microchannels Using Line-Based Laser Induced Plasma Micromachining

Microtexturing of surfaces has various applications that often involve texturing over large (macroscale) areas with high precision and resolution. This demands scalability and speed of texturing while retaining feature sizes of the order of a few microns. Microchannels are a versatile microfeature, which are often used in microfluidic devices and can be arrayed or joined to form patterns and free-form geometries. We present a technique to fabricate microchannels on surfaces with high-speed and by using a multimaterial process, namely, laser induced plasma micromachining (LIPMM). The process has the potential to machine metals, ceramics, polymers, and other transparent, brittle, and hard-to-machine materials. The presented technique uses an optical system to modify the laser spot into the shape of a line, to fabricate microchannels directly without scanning as in the case of a regular circular spot. The process schematics are shown, and micromachining experiments on polished aluminum are discussed. Moreover, it is shown that the depth and width of the channels may be varied by changing process parameters like the pulse energy, pulse frequency, and number of exposures.

Signaling molecules from Lactuca sativa L. induced quorum sensing phenotypes in bacteria

The outcome of the present investigation revealed that lettuce (Lactuca sativa L.) extract strongly interferes with acyl homoserine lactone (AHL) regulated physiological functions in the bioreporter strain, Chromobacterium violaceum CV026. Extracts of L. sativa also promoted production of virulence factors in plant pathogen, Pectobacterium carotovorum, and significantly increased tissue maceration on potato tubers when there was a low concentration (103 cfu · ml−1) of the bacterium was used. The thin layer chromatogram which visualised with AHL bioreporter strain, CV026, showed that L. sativa extract produced a circular spot with a diffuse edge tail and migrated with the same mobility as standard N-hexanoyl-L-homoserine lactone (C6-HSL). Gas Chromatography Mass Spectroscopy (GC-MS) analysis of the lettuce extract resulted in the identification of 19 compounds of which homoserine was identified for the first time in plants. Homoserine accounted for 2.37% of the total constituents. It is a new finding that lettuce contains AHL like substances (homoserine) which excite AHL related quorum sensing (QS) in bacteria.

Two new Indo-Pacific species in the Eviota nigriventris complex (Teleostei: Gobiidae)

Three species are recognized in the Eviota nigriventris complex, two of them new. Eviota nigriventris Giltay is a species with a red ventral band, edged dorsally with a narrow white line, the ventral band ending in an asymmetrical black mark at the caudal-fin base; E. dorsopurpurea n. sp. is a species with a purple back and head and a black ventral band ending in a semi-circular spot; and E. dorsogilva n. sp. is a species with a black to dark reddish ventral band ending in a semicircular spot and has a cream-colored back. Eviota dorsogilva and E. dorsopurpurea also differ in counts, pectoral-fin base coloration and eye size.

Surface Brightness Variation of the Contact Binary SW Lac: Clues From Doppler Imaging

In this study, we present the preliminary light curve analysis of the contact binary SW Lac, using B, V light curves of the system spanning 2 years (2009 - 2010). During the spot modeling process, we used the information coming from the Doppler maps of the system, which was performed using the high resolution and phase dependent spectra obtained at the 2.1m Otto Struve Telescope of the McDonald Observatory, in 2009. The results showed that the spot modeling from the light curve analysis are in accordance with the Doppler maps, while the non-circular spot modeling technique is needed in order to obtain much better and reliable spot models.