Uncertainty about efficiency and sustainability of shrimp production due to diseases and climatic events may prevent Vietnam from attaining US $10 million target from shrimp exports by 2025. We surveyed 120 and 159 shrimp farmers from Khánh Hòa and Trà Vinh provinces, respectively, to obtain information on their input use, production levels and the effects of diseases and climate change events on their farm profitability. Stochastic production frontier analysis (SFA) discovered that the number of workers, crops and seed costs positively influenced farmers’ profits, while cost of chemicals and labour negatively affected the profit of Khánh Hòa farmers. The number of workers and chemical costs positively affected profits in Trà Vinh, while cost of labour and energy, the number of crops and average stocking density negatively influenced farmer profit in Trà Vinh. Number of years of schooling, experience and average size of ponds positively influenced economic efficiency, while the number of ponds and climatic change events negatively influenced efficiency in Khánh Hòa province. Age and alternative power source positively affected economic efficiency, while disease prevalence affected efficiency of Trà Vinh. All farms practicing intensive or extensive shrimp production achieved 90% efficiency. The government should encourage the wise use of resources, high-quality seeds and a sensitive balance between intensive and extensive culture to sustainably attain its national production and export goals.
Alzheimer’s disease (AD) is
a protein misfolding disease
commonly characterized by neuritic amyloid plaques and proteinaceous
fibrillar aggregate deposits composed of β-amyloid (Aβ)
aggregates. The dynamic aggregation of Aβ forms toxic, nanoscale
aggregate species which proceed from oligomers to fibrils. Currently,
there is need for rapid and direct detection of Aβ peptide aggregation
and interaction with lipid membranes, as detecting an interaction
with various lipid environments will provide insights to better understand
how interactions may modulate membrane function on cellular surfaces,
leading to the progression of AD. The goal of this study was to utilize
a colorimetric, biomimetic, vesicle-binding assay as a biosensor to
detect and investigate the occurrence of neurodegenerative disease-associated
protein aggregation and interaction with lipid membranes. Lipid/polydiacetylene
(PDA) vesicles were exposed to monomeric preparations of Wild Type
Aβ(1–40) or point mutations in Aβ with amino acid
substitutions that are commonly associated with familial AD (E22G
Arctic, E22Q Dutch, A21G Flemish, D23N Iowa, and E22K Italian). We
investigated how these substitutions affect Aβ(1–40)
aggregation and interaction with lipid vesicles designed to mimic
biological membranes. Time-resolved colorimetric measurements were
obtained and reveal that exposure to lipid/PDA vesicle biosensors
results in the direct detection of mutant Aβ(1–40) peptide–lipid
interaction events. Aβ(1–40) peptide aggregate membrane
activity varies among Aβ peptide variants and lipid composition.
In addition, we used atomic force microscopy and Thioflavin T fluorescence
assays to distinguish the stages of Aβ(1–40) aggregate
formation, morphology, and membrane activity. These studies provide
a simple means of aggregate detection and insight into the role of
cellular surfaces in the mechanism of AD aggregation.
Supplementary materials in this section are entirely based on the simulations study. All results and from different percent of contamination and the different sample size are summarized though the figures below. Figures 1, 2 3, and 4 summarizes the results in of scenario 1 in which the design space was contaminated using a normal contamination.
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