Hydraulic Strategy of Cactus Trichome for Absorption and Storage of Water under Arid Environment

Being an essential component in various metabolic activities, water is important for the survival of plants and animals. Cacti grown in arid areas have developed intrinsic water management systems, such as water collection through spines, water absorption through trichome, and water storage using mucilage. The water collection method of cactus is well-documented, but its water absorption and storage strategies remain to be elucidated. Thus, this study analyzed the morphology and wettability of cactus trichomes by using advanced bio-imaging techniques and by performing in vitro experiments on an artificial system mimicking these structures, respectively. In addition, the in situ water absorption process through the trichome cluster was quantitatively visualized. This paper proposes a new bio-inspired technique for dew collection based on information about the water management strategies of cactus. This study discusses the underlying water absorption and storage strategies of cactus and provides the experimental database required to develop a biomimetic water management device.114Ysciescopu

Novel water filtration of saline water in the outermost layer of mangrove roots

The scarcity of fresh water is a global challenge faced at present. Several desalination methods have been suggested to secure fresh water from sea water. However, conventional methods suffer from technical limitations, such as high power consumption, expensive operating costs, and limited system durability. In this study, we examined the feasibility of using halophytes as a novel technology of desalinating high-concentration saline water for long periods. This study investigated the biophysical characteristics of sea water filtration in the roots of the mangrove Rhizophora stylosa from a plant hydrodynamic point of view. R. stylosa can grow even in saline water, and the salt level in its roots is regulated within a certain threshold value through filtration. The root possesses a hierarchical, triple layered pore structure in the epidermis, and most Na+ ions are filtered at the first sublayer of the outermost layer. The high blockage of Na+ ions is attributed to the high surface zeta potential of the first layer. The second layer, which is composed of macroporous structures, also facilitates Na+ ion filtration. This study provides insights into the mechanism underlying water filtration through halophyte roots and serves as a basis for the development of a novel bio-inspired desalination method.Creative Research Initiative (Diagnosis of Biofluid Flow Phenomena and Biomimic Research) of the Ministry of Science, ICT and Future Planning (MSIP) , National Research Foundation (NRF) of Korea , ICT R&D program of MSIP/IITP (Korea

Study on a model of street vended food choices by Korean high school students

Street vended food (SVF) includes food and beverages prepared and sold outdoors or in public areas by street merchants for consumption on the scene or later without further preparation. Due to its low price and convenience, SVF has been popular in Korea for a long time, particularly with high school students. Beyond Korea, SVF is also popular in southeast Asia and southern Africa in the form of ready-to-eat food. This study on high school students, who are main consumers of SVF in Korea, focused on the factors that affect consumer loyalty. The study was performed by questionnaire and used AMOS software to develop a structural equation model. The results of verifying the model's fidelity were χ2 = 685.989, df = 261, GFI = 0.851, AGFI = 0.814, NFI = 0.901, CFI = 0.907, RMR = 0.048, indicating a satisfying structural model. SVF quality and service, emotional response, and the physical environment had a statistically significant effect on consumer loyalty. In contrast, SVF sanitation had no statistically significant effect on consumer loyalty. Based on these results, the sanitary management of SVF needs to be addressed immediately combined with education for SVF providers to maintain a clean environment

STAT1 and Nmi are downstream targets of Ets-1 transcription factor in MCF-7 human breast cancer cell

AbstractEts-1 is a cellular homologue of the product of the viral ets oncogene of the E26 virus, and it functions as a tissue-specific transcription factor. It plays an important role in cell proliferation, differentiation, lymphoid cell development, transformation, angiogenesis, and apoptosis. Ets-1 controls the expression of critical genes involved in these processes by binding to ets binding sites present in the transcriptional regulatory regions. Here, we transiently overexpressed Ets-1 in MCF-7 and comprehensively searched for potential downstream targets of Ets-1 by cDNA microarray analysis. The expressions of several interferon-related genes including STAT1 and Nmi were augmented by the overexpression of Ets-1. RT-PCR and Western blotting confirmed the increase in the levels of STAT1 and Nmi mRNA and protein. In contrast, Ets-1 siRNA decreased the expression of STAT1 and Nmi proteins. As in our transient transfection experiments, stable overexpression of Ets-1, also increased the protein expression of STAT1 and Nmi in MCF-7 cells. Taken together, our results indicate that STAT1 and Nmi are downstream targets of Ets-1 in MCF-7 human breast cancer cells

Effects of artificial, stand-level induced drought and thinning on Pseudotsuga menziesii plantation eco-physiology, and soil respiration

Thesis (Ph.D.)--University of Washington, 2019Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) is an important tree species in the Pacific Northwest (PNW), ranging from central British Columbia to Mexico. Douglas-fir is widely used for wood production and silvicultural applications such as thinning, and fertilization have led to increases in productivity. Climate change in the PNW is predicted to increase temperatures, and less precipitation in the summer is expected to increase drought effects and reduce Douglas-fir plantation growth and productivity. Therefore, better understanding the impacts of climate change on Douglas-fir growth and physiology, the interactive effects of silviculture and reduced water availability (i.e., drought) on Douglas-fir plantations in PNW is needed. This study was conducted at UW’s Pack Forest to evaluate the effects of thinning and drought stress on tree physiology and growth. Throughfall exclusion panels were used to create an artificial drought on the study site, reducing 40 % of throughfall precipitation. The first and second studies examined the effects of thinning and drought stress on tree physiological responses, and stem growth. Tree physiological traits such as sapflow density, photosynthesis, leaf water potential and stem growth increased with thinning and decreased with drought. Thinning increased physiological measures and stem growth, and drought stress reduced physiological measures and stem growth. The physiological responses and stem growth on the combination plot (thinning and throughfall exclusion) were similar to the control plot, which indicated that thinning mitigated the drought effects on tree physiology and growth. The third study examined the impacts of thinning and drought on soil respiration. Soil respiration decreased on the throughfall exclusion plot, but soil respiration on the thinned plot was similar to the control plot. Q10 which is the temperature sensitivity of soil respiration, is also negatively affected by the two treatments. Drought treatment lowered the soil respiration by decreasing soil moisture which directly affected root production and breakdown of the organic matter forming the substrate for heterotrophic respiration. Thinning initially reduced soil respiration due to a reduction in tree root respiration, then the soil respiration reached a similar level as the control, likely due to decomposition of dead roots. Overall results indicate that thinning can be beneficial in Douglas-fir plantations experiencing drought stress by increasing soil water availability and serve as a mitigating tool to climate change