Big defensin is a 79-residue peptide derived from hemocytes of the Japanese horseshoe crab. The amino acid sequence of big defensin is divided into an N-terminal hydrophobic domain and a C-terminal ...cationic domain, which are responsible for antimicrobial activities against Gram-positive and -negative bacteria, respectively. The N-terminal domain of big defensin forms a unique globular conformation with two *a-helices and a parallel *b-sheet, while the C-terminal domain adopts a *b-defensin-like fold. Although our previous study implied that big defensin changes its N-terminal structure in a micellar environment, due to the poor quality of the NMR spectra it remained to be resolved whether the N-terminal domain adopts any structure in the presence of micelles. In this analysis, we successfully determined the structure of the N-terminal fragment of big defensin in a micellar solution, showing that the fragment peptide forms a single *a-helix structure. Moreover, NMR experiments using paramagnetic probes revealed that the N-terminal domain of big defensin penetrates into the micelle with a dipping at the N-terminal edge of the *a-helix. Here, we propose a model for how big defensin associates with the target membrane.
This study aimed to compare the ecological sustainability of marine shrimp ponds located in 'highlands' (licensed) and 'lowlands' (unlicensed located in Permanent Preservation Areas) in Sergipe ...State, Brazil. In each area four ponds were studied during summer and winter. Data on the use of feed inputs, shrimp biomass and aspects related to the management were collected through direct observation and semi-structured interviews. Sustainability was measured by indicators that showed lower ecological sustainability of shrimp farming located at 'highlands'. The study suggests that the used indicators are a useful and simple tool for measurement of the ecological sustainability of marine shrimp ponds, but indicators of social and economic dimensions are also relevant to be applied in such context, providing a systematic evaluation of the sustainability of the activity.
Nowadays there are fishery resources that have suffered the consequences of overexploitation, pollution or climate change, therefore, the population of marine organisms of commercial importance has ...diminished noticeably. One of the alternatives to mitigate this reduction, is the diversification of the fishery and aquaculture activity, through value creation. This article has as a general objective to develop an added value proposal for the commercialization of crabs, through a Soft Shell Crab closed system technical production, for the coastal region of the State of Sonora, in such a way to be taken as a viable option of economic and social growing for the community, by a sustainable development, the establishment of communication mechanisms and a permanent concentration among the different actors and factors that will constitute the soft crab technical process, acceding the establishment of strategic alliances and commercial agreements for the integration of productive chains with the participation in state and national production programs, with the purpose of product commercialization.
Horseshoe crab can be poisonous and intoxication due to intake of horseshoe crab is possible. Horseshoe crab intoxication can be seen in many countries with seacoasts including Thailand. Here, the ...authors summarized the death rate due to horseshoe crab poisoning in Thailand.
Astaxanthin is a high value pigment, extracted by using organic solvent, acetone: hexane (3:1) (v/v), from shrimp waste such as carapace, cephalothoraxes, chelipeds and perciopods etc. Astaxanthin ...showed potential effect against various diseases such as cancers, hypertension, diabetes, cardiovascular, gastrointestinal, liver, neurodegenerative, and skin diseases. Astaxanthin is available in much form like tablets, gel, capsule etc. The minimum of dosage of Astaxanthin 4mg/day. More consumption of Astaxanthin does not have any effect in our body; Astaxanthin is more helpful for the people above 40 years of age. Phytoplankton and some micro algae is the primary level source of Astaxanthin. The objective of this study is to increase the productivity as well as improve the efficiency of extraction using organic solvents from shrimp waste. Finally, the Astaxanthin was quantified as 33.98 mu g and it was extracted in 5gm of shrimp waste by using chemical extraction method and analyzed by Ultraviolet-Visible spectroscopy and thin layer chromatography.
In this study, crab shells were recycled as an adsorbent for the removal of phosphate. The effects of shell particle size, temperature, pH and phosphate concentration on phosphate removal were ...investigated. Shell particles less than 1000 mm in diameter removed more than 85% of 500 mg/L phosphate in 24 h while particles 3350 mm in diameter exhibited only 50% removal efficiency. Temperature showed negligible effect on phosphate removal in the range of 15-45 °C. Although removal efficiency was highest at pH 2.0, the efficiency remained 50-60% at pH of 4.0-10.0. The maximum removal capacity was calculated as 108.9 mg/g through Langmuir isotherm plotting, which was 17.0 and 4.7 times higher than those of coal fly ash and scallop shells, respectively. Although calcium carbonate played an active role in the removal of phosphate, both proteins composing 12.5% of crab shells and cellulose-like backbone of the crab shells also played an important role in phosphate removal.
The South Tianshan orogenic belt, the southwestern extension of the Central Asian orogenic belt, separates the Yili-Central Tianshan block to the north from the Tarim block to the south. This belt is ...marked by a Proterozoic metamorphic complex, ophiolites, granitoids, mafic intrusions and younger high-pressure and low-temperature metamorphic rocks. The Jingbulake mafic intrusion in this belt is a zoned body composed of pyroxene diorite, olivine gabbro and wehrlite. Pyroxenite locally intrudes all of these rocks but is most abundant along the boundaries between pyroxene diorite and olivine gabbro. Both the olivine gabbro and wehrlite contain disseminated sulfide mineralization, and a sulfide rich orebody intrudes the pyroxenite. The pyroxene diorite has a SHRIMP zircon U-Pb isotope age of 431 +/- 6 Ma. All the rocks have nearly flat chondrite-normalized rare earth element patterns and show negative Nb-Ta and P-Ti anomalies on mantle-normalized trace element diagrams. They have positive eNd values (+ 1.6 to + 4.0), and low ( super(87)Sr/ super(86)Sr) sub(i) ratios (0.7039-0.7048), indicative of a depleted mantle source. The rocks all have low Th/Nb ratios, narrow isotopic variations, and slightly negative Zr-Hf anomalies, suggesting insignificant crustal contamination. They are enriched in large ion lithophile elements, such as Cs, Rb, Ba, Pb and Sr, and have constant but radiogenic Pb isotopic ratios of super(206)Pb/ super(204)Pb (18.159-18.250), super(207)Pb/ super(204)Pb (15.599-15.633) and super(208)Pb/ super(204)Pb (37.978-38.250), consistent with the involvement of subduction-related fluids and sediments in the source region. The Jingbulake intrusion, together with other mafic intrusions in the belt, suggests subduction of the South Tianshan oceanic lithosphere beneath the Yili-Central Tianshan block. The subduction-related fluids and sediments not only metasomatized the mantle wedge above the subduction zone, but also triggered the melting of the mantle due to the addition of water.
In this paper we estimate the living carbon lost from Ecuador's mangrove forests since the advent of export-focused shrimp aquaculture. We use remote sensing techniques to delineate the extent of ...mangroves and aquaculture at approximately decadal periods since the arrival of aquaculture in each Ecuadorian estuary. We then spatiotemporally calculate the carbon values of the mangrove forests and estimate the amount of carbon lost due to direct displacement by aquaculture. Additionally, we calculate the new carbon stocks generated due to mangrove reforestation or afforestation. This research introduces time and LUCC (land use / land cover change) into the tropical forest carbon literature and examines forest carbon loss at a higher spatiotemporal resolution than in many earlier analyses. We find that 80 percent, or 7,014,517 t of the living carbon lost in Ecuadorian mangrove forests can be attributed to direct displacement of mangrove forests by shrimp aquaculture. We also find that IPCC (Intergovernmental Panel on Climate Change) compliant carbon grids within Ecuador's estuaries overestimate living carbon levels in estuaries where substantial LUCC has occurred. By approaching the mangrove forest carbon loss question from a LUCC perspective, these findings allow for tropical nations and other intervention agents to prioritize and target a limited set of land transitions that likely drive the majority of carbon losses. This singular cause of transition has implications for programs that attempt to offset or limit future forest carbon losses and place value on forest carbon or other forest good and services.
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