Building Morphological Chains for Agglutinative Languages

In this paper, we build morphological chains for agglutinative languages by using a log-linear model for the morphological segmentation task. The model is based on the unsupervised morphological segmentation system called MorphoChains. We extend MorphoChains log linear model by expanding the candidate space recursively to cover more split points for agglutinative languages such as Turkish, whereas in the original model candidates are generated by considering only binary segmentation of each word. The results show that we improve the state-of-art Turkish scores by 12% having a F-measure of 72% and we improve the English scores by 3% having a F-measure of 74%. Eventually, the system outperforms both MorphoChains and other well-known unsupervised morphological segmentation systems. The results indicate that candidate generation plays an important role in such an unsupervised log-linear model that is learned using contrastive estimation with negative samples.Comment: 10 pages, accepted and presented at the CICLing 2017 (18th International Conference on Intelligent Text Processing and Computational Linguistics

Structure and membrane organization of photosystem II in green plants

Photosystem II (PSII) is the pigment protein complex embedded in the thylakoid membrane of higher plants, algae, and cyanobacteria that uses solar energy to drive the photosynthetic water-splitting reaction. This chapter reviews the primary, secondary, tertiary, and quaternary structures of PSII as well as the function of its constituent subunits. The understanding of in vivo organization of PSII is based in part on freeze-etched and freeze-fracture images of thylakoid membranes. These images show a resolution of about 40-50 Angstrom and so provide information mainly on the localization heterogeneity, dimensions, and shapes of membrane-embedded PSII complexes. Higher resolution of about 15-40 Angstrom has been obtained from single particle images of isolated PSII complexes of defined and differing subunit composition and from electron crystallography of 2-D crystals. Observations are discussed in terms of the oligomeric state and subunit organization of PSII and its antenna components.</p

Microalgal Aquafeeds As Part of a Circular Bioeconomy

Photosynthetic microalgae are unicellular plants, many of which are rich in pro-tein, lipids, and bioactives and form an important part of the base of the natural aquatic food chain. Population growth, demand for high-quality protein, and depletion of wildfish stocks are forecast to increase aquacultural fish demand by 37% between 2016 and 2030. This review highlights the role of microalgae andrecent advances that can support a sustainable‘circular’aquaculture industry. Microalgae-based feed supplements and recombinant therapeutic production offer significant opportunities to improve animal health, disease resistance,and yields. Critically, microalgae in biofloc, ‘green water’, nutrient remediation,and integrated multitrophic aquaculture technologies offer innovative solutions for economic and environmentally sustainable development in line with key UN Sustainability Goals

Localization of the 23-kDa subunit of the oxygen-evolving complex of photosystem II by electron microscopy

A dimeric photosystem II light-harvesting II super complex (PSII-LHCII SC), isolated by sucrose density gradient centrifugation, was previously structurally characterized. This PSII-LHCII SC bound the 33-kDa subunit of the oxygen-evolving complex (OEC), but lacked the 23-kDa and 17-kDa subunits of the OEC. Here the isolation procedure was modified by adding 1 M glycine betaine (1-carboxy-N,N,N-trimethylmethanaminium hydroxide inner salt) to the sucrose gradient mixture. This procedure yielded PSII-LHCII SC that contained both the 33-kDa and the 23-kDa subunits and had twice the oxygen-evolving capacity of the super complexes lacking the 23-kDa polypeptide. Addition of CaCl2 to PSII-LHCII SC with the 23-kDa subunit attached did not increase the oxygen-evolution rate. This suggests that the 23-kDa subunit is bound in a functional manner and is present in significant amounts. Over 5000 particle projections extracted from electron microscope images of negatively stained PSII-LHCII SC, isolated in the presence and absence of glycine betaine, were analyzed using single-particle image-averaging techniques. Both the 23-kDa and 33-kDa subunits could be visualized in top-view and side-view projections. In the side view the 23-kDa subunit is seen to protrude 0.5-1 nm further than the 33-kDa subunit, giving the PSII particle a maximal height of 9.5 nm. Measured from the centres of the masses, the two 33-kDa subunits associated with the dimeric PSII-LHCII SC are separated by 6.3 nm. The corresponding distance between the two 23-kDa subunits is 8.8 nm.

Plants lacking the main light-harvesting complex retain photosystem II macro-organization

Photosystem II (PSII) is a key component of photosynthesis, the process of converting sunlight into the chemical energy of life. In plant cells, it forms a unique oligomeric macrostructure in membranes of the chloroplasts. Several light-harvesting antenna complexes are organized precisely in the PSII macrostructure—the major trimeric complexes (LHCII) that bind 70% of PSII chlorophyll and three minor monomeric complexes—which together form PSII supercomplexes. The antenna complexes are essential for collecting sunlight and regulating photosynthesis, but the relationship between these functions and their molecular architecture is unresolved. Here we report that antisense Arabidopsis plants lacking the proteins that form LHCII trimers have PSII supercomplexes with almost identical abundance and structure to those found in wild-type plants. The place of LHCII is taken by a normally minor and monomeric complex, CP26, which is synthesized in large amounts and organized into trimers. Trimerization is clearly not a specific attribute of LHCII. Our results highlight the importance of the PSII macrostructure: in the absence of one of its main components, another protein is recruited to allow it to assemble and function

Membrane-protein crystallization in cubo: Temperature-dependent phase behaviour of monoolein-detergent mixtures

The lipidic cubic phase of monoolein has proved to be a matrix well suited to the production of three-dimensional crystals of membrane proteins. It consists of a single continuous bilayer, which is contorted in three-dimensional space and separates two distinct water channels. It has previously been proposed that on the addition of precipitants, membrane proteins embedded in the cubic phase migrate through the matrix to nucleation sites and that this process is dependent upon the stability of the lipidic cubic phase. Here, the effect of detergent type (C-8-C-12 glucosides, C-8-C-12 maltosides and C-7 thioglucoside) and concentration (1-3 x the critical micelle concentration; CMC) on cubic phase stability are reported in the form of the temperature-dependent phase behaviour (268-313 K) in 40% aqueous solution. The results are tabulated to show the best monoolein (MO)-detergent mixtures, mixing temperatures and crystallization temperatures identified. Monoolein-detergent mixtures suited for low-temperature in cubo crystallization of temperature-sensitive proteins are also reported for the first time. These mixtures can be prepared at low temperatures (mixed at less than or equal to 288 K) and remain stable at 277 K for a period of at least one month. They include MO- heptyl thioglucoside (1x and 3x CMC), MO-nonyl glucoside (3 x CMC), MO-octyl maltoside (3 x CMC), MO-nonyl maltoside (1 x CMC) and MO-decyl maltoside (1 x CMC)

Lexical Extension and Grammatical Transformations

Proceedings of the Sixth Annual Meeting of the Berkeley Linguistics Society (1980), pp. 238-24

Design scenarios of outdoor arrayed cylindrical photobioreactors for microalgae cultivation considering solar radiation and temperature

Advancing microalgae biotechnologies requires the design of high efficiency, large scale outdoor photobioreactor systems. Here we present a predictive biomass productivity model to define system design parameters yielding high biomass productivities for a facility encompassing arrays of cylindrical photobioreactors (PBRs) in a sub-tropical location (Brisbane, Australia). The model analyses the temperature and the light distributed through the culture medium as a function of PBR height, diameter, spacing distance between reactors, biomass concentration and cultivation regime (continuous vs. batch; fixed vs. capped temperature control). Temporal changes in light and temperature were used to predict volumetric and areal productivities (Pvol and Pareal respectively) for three Chlorella strains (C. vulgaris, C. sp. 11_H5 and C. pyrenoidosa). A simple empirical relationship was derived to rapidly predict Pvol in PBR arrays based on the ratio of spacing distance and reactor height (L/H) if the Pvol of a single, unshaded PBR was known. For C. vulgaris under a continuous operation and variable temperature (within its maximum growth threshold), the highest Pvol in the range analysed was obtained at the smallest diameter (0.1 m), highest biomass concentration (1.5 g L−1) and largest L/H, (Pvol ~0.3 g L−1 d−1). In contrast, the highest Pareal (~50 t ha−1 yr−1) was found at higher diameters (0.15 and 0.3 m), a lower biomass concentration (0.3 g L−1) and low L/H (0.2–0.4); this was attributed to a higher overall culture volume per PBR and per area. Our predictions, based on light and temperature effects on productivity, suggest that attaining a high Pvol could reduce costs, energy and materials associated with water usage, harvest loads and PBRs; whereas attaining a Pareal toward its maxima could reduce costs associated with land. The model supports effective PBR array design and process optimisation to help minimise production cost