3,459 research outputs found
THE POTENTIAL OF FRESHWATER MACROALGAE AS A BIOFUELS FEEDSTOCK AND THE INFLUENCE OF NUTRIENT AVAILABILITY ON FRESHWATER MACROALGAL BIOMASS PRODUCTION
Extensive efforts have been made to evaluate the potential of microalgae as a biofuel feedstock during the past 4-5 decades. However, filamentous freshwater macroalgae have numerous characteristics that favor their potential use as an alternative algal feedstock for biofuels production. Freshwater macroalgae exhibit high rates of areal productivity, and their tendency to form dense floating mats on the water surface imply significant reductions in harvesting and dewater costs compared to microalgae. In Chapter 1, I reviewed the published literature on the elemental composition and energy content of five genera of freshwater macroalgae. This review suggested that freshwater macroalgae compare favorably with traditional bio-based energy sources, including terrestrial residues, wood, and coal. In addition, I performed a semi-continuous culture experiment using the common Chlorophyte genus Oedogonium to investigate whether nutrient availability can influence its higher heating value (HHV), productivity, and proximate analysis. The experimental study suggested that the most nutrient-limited growth conditions resulted in a significant increase in the HHV of the Oedogonium biomass (14.4 MJ/kg to 16.1 MJ/kg). Although there was no significant difference in productivity between the treatments, the average dry weight productivity of Oedogonium (3.37 g/m2/day) was found to be much higher than is achievable with common terrestrial plant crops. Although filamentous freshwater macroalgae, therefore, have significant potential as a renewable source of bioenergy, the ultimate success of freshwater macroalgae as a biofuel feedstock will depend upon the ability to produce biomass at the commercial-scale in a cost-effective and sustainable manner. Aquatic ecology can play an important role to achieve the scale-up of algal crop production by informing the supply rates of nutrients to the cultivation systems, and by helping to create adaptive production systems that are resilient to environmental change. In Chapter 2, I performed a review and an analysis of data from the published literature on the large-cultivation of freshwater macroalgae. This study revealed that the large-scale cultivation of freshwater macroalgae is feasible at relatively low cost using currently available technologies such as the Algal Turf Scrubber system (ATS). In addition, graphical analyses of published data obtained from ATS systems of varying sizes in operation worldwide revealed that both macroalgal biomass productivity and nutrient removal rates are hyperbolically related to the areal loading rates of both total nitrogen and total phosphorus. An assessment of the limited existing literature on carbon dioxide amendments suggested that the effectiveness and need for CO2 supplementation of macroalgal production systems like the ATS has not yet been conclusively demonstrated. Overall, this thesis demonstrates that filamentous freshwater macroalgae have great potential as a feedstock for both liquid and solid fuels, especially if nutrient-rich wastewater can be used as the supply of water and mineral nutrients. In addition, this thesis highlights the importance of studying the algal cultivation conditions that influence trade-offs between nutrient loading, biomass productivity, and biomass energy content. In particular, the hyperbolic relationship between algal biomass productivity and the areal loading rates of both total nitrogen and total phosphorus should provide critical insight when considering the production costs of macroalgal biomass at the commercial-scale
Availability of hairy vetch (Vicia villosa Roth) as leguminous green manure crops for organic rice in reclaimed saline land
Hairy vetch (Vicia villosa) is playing an important role to improve soil physical properties and soil fertility for the supply of crop nutrients and this crop is also used as a representative legumes green manure for the production of organic agricultural food. In this study we evaluated the availability of hairy vetch in reclaimed organic rice cultivation. The response to increasing salinity was analyzed by means of the germination rate and seedling growth of hairy vetch. Results showed that seed germination of hairy vetch decreased insignificantly up to concentration of 0.6% NaCl. However, shoot and root growth of hairy vetch showed significant reduction at salinity concentrations higher than 0.1% NaCl level. In these results we were considered that hairy vetch can be use under concentration of 0.1% salinity as green manure for reclaimed saline agriculture
Učinci prenatalne i postnatalne izloženosti perfluorooktanskoj kiselini na ekspresiju glavnih gena povezanih s reprodukcijom u mišjem hipotalamusu i spolnim žlijezdama
Perfluorooctanoic acid (PFOA), a ubiquitous environmental pollutant reported to be an endocrine disruptor, is used in many industrial and consumer products. Although the adverse effects of PFOA on the reproductive health of animals and humans have been widely reported, most studies have focused on assessing the anatomical features and conventional histology of adult gonads. Therefore, the molecular mechanisms activated in the hypothalamus and gonads following PFOA exposure during the pre- and postnatal periods are not clear. This study used a mouse model to evaluate the effects of PFOA exposure on the alteration of molecular mechanisms in the hypothalamus and gonads during the prenatal and postpartum periods. Changes in gene and protein expression following PFOA exposure were evaluated by quantitative polymerase chain reaction and Western blotting, respectively. Kisspeptin 1 and gonadotropin-releasing hormone expression in the hypothalamus of female and male mouse pups was significantly decreased. Additionally, Cyp17a1 expression was upregulated in male offspring testes, while Cyp17a1 and Cyp19a1 expression was downregulated in female offspring ovaries. Changes at the molecular level due to PFOA exposure in the early stages of development did not show sex-related differences in the hypothalamus; however, such differences were confirmed in the gonads. These results could be used as basic data to study the molecular mechanisms underlying the reproductive dysfunction caused by PFOA exposure in the early stages of embryonic development.Perfluorooktanska kiselina (PFOA) sveprisutna je onečišćujuća tvar za okoliš, za koju je zabilježeno da uzrokuje i endokrinopatije, a upotrebljava se u mnogim industrijskim proizvodima. Bez obzira na poznate i zabilježene nuspojave PFOA-e na reproduktivno zdravlje životinja i ljudi, većina se istraživanja usredotočuje na procjenu anatomskih histoloških značajki u spolnim žlijezdama odraslih jedinki. Molekularni mehanizmi koji se aktiviraju u hipotalamusu i spolnim žlijezdama nakon izlaganja PFOA-i stoga nisu razjašnjeni. U ovom je istraživanju upotrijebljen mišji model za procjenu učinaka izlaganja PFOA-i na promjenu molekularnih mehanizama u hipotalamusu i spolnim žlijezdama za vrijeme prijeporođajnog i poslijeporođajnog razdoblja. Promjene u ekspresiji gena i proteina nakon izloženosti PFOA-i analizirane su kvantitativnom PCR metodom i metodom Western blotting. Ekspresija kispeptina 1 i hormona koji oslobađa gonadotropin u hipotalamusu ženske i muške mladunčadi bila je znakovito smanjena. Osim toga ekpresija Cyp17a1 bila je pojačana u testisima muških potomaka, dok je ekspresija Cyp17a1 i Cyp19a1 u jajnicima ženskih potomaka bila smanjena. Kod promjena na molekularnoj razini u hipotalamusu u ranim razvojnim stadijima nije bilo razlike među spolovima, dok je kod promjena u spolnim žlijezdama povrđena razlika među spolovima. Rezultati ovog istraživanja mogli bi biti korisni kao osnovni podaci u proučavanju molekularnih mehanizama podležeće reproduktivne disfunkcije uzrokovane izloženošću PFOA-i u ranim stadijima embrionalnog razvoja
Cyclophilin A Cpr1 Protein Modulates the Response of Antioxidant Molecules to Menadione-induced Oxidative Stress in Saccharomyces cerevisiae KNU5377Y
AbstractObjectivesThe cellular function of cyclophilin A (CypA) differs between organisms, even though CypA is conserved in both prokaryotes and eukaryotes. The purpose of this study was to elucidate the role of activated CypA isoform CPR1 in the antioxidative mechanisms of Saccharomyces cerevisiae under menadione (MD)-induced oxidative stress.MethodsFour S. cerevisiae strains, KNU5377Y (kwt) and BY4741 (bwt), and their isogenic cpr1Δ mutant strains (kc1 and bc1), were treated with MD, at a concentration ranging between 0.25 and 0.4 mM. Cpr1-mediated antioxidative effects were analyzed by measuring the levels of cellular glutathione (GSH) and ascorbate (AsA)-like molecules in yeast.ResultsGSH and AsA-like reductant molecule concentrations were more reduced in the presence of MD in the kc1 strain than in the kwt strain; whereas, there was no significant difference between the bwt and bc1 strains under the same conditions. In kc1 strain samples, we observed a reduction in the expression of proteins related both to GSH synthesis and the recycling system, and simultaneously, downregulation of GSH synthetase and GSH reductase activities were also evident. Oxidative stress in the kc1 strain was alleviated by the application of the GSH and AsA analog.ConclusionThese results indicate that activated Cpr1 modulates the response of antioxidant molecules involved in cellular redox homeostasis of KNU5377Y during oxidative stress induced by MD
Antiosteoporosis Activity of New Oriental Medicine Preparation (Kyungokgo Mixed with Water Extract of Hovenia dulcis
Protective effect of new oriental medicine (Kyungokgo mixed with water extract of Hovenia dulcis, KOGHD) was assessed on the bone loss induced mice by ovariectomy. In the in vivo experiments, antiosteoporosis effect of KOGHD was investigated using ovariectomized osteoporosis mice model. After 6 weeks of treatment, the mice were euthanized, and the effect of Kyungokgo (KOG) and KOGHD on body weight, spleen weigh, thymus weight, uterine weight, serum biochemical indicators, bone weight and length, immune cell population, bone morphometric parameters, and histological stains was observed. Our results showed that KOGHD prevented the deterioration of trabecular microarchitecture caused by ovariectomy, which were accompanied by the lower levels of bone turnover markers and immune cell population as evidenced by the inhibition of RANKL-mediated osteoclast differentiation without cytotoxic effect on bone marrow derived macrophages (BMMs). Therefore, these results suggest that the Hovenia dulcis (HD) supplementation in the KOG may also prevent and treat bone loss
Prognostic implications of ezrin and phosphorylated ezrin expression in non-small cell lung cancer
BACKGROUND: The cytoskeletal organizer ezrin is a member of the ezrin-radixin-moesin (ERM) family and plays important roles in not only cell motility, cell adhesion, and apoptosis, but also in various cell signaling pathways. Phosphorylation at Thr-567 and Tyr-353 are key regulatory events in the transition of the dormant to active form of ezrin. This study investigated the prognostic implications of ezrin and phosphorylated ezrin (p-ezrin) expression in non-small cell lung carcinoma (NSCLC). METHODS: Ezrin and p-ezrin protein expressions were examined by immunohistochemistry in 150 NSCLC and adjacent non-tumor tissues and 14 normal lung tissues. qRT-PCR was used to determine ezrin mRNA expression levels in fresh tissues. The correlations between overexpression of ezrin and p-ezrin and the clinicopathological features of NSCLC were analyzed. The survival rates were calculated by the Kaplan-Meier method for 108 NSCLC cases. RESULTS: Ezrin and ezrin(Thr-567) proteins showed cytosolic and membranous staining patterns; however, ezrin(Tyr-353) protein only showed cytosolic staining. Ezrin and p-ezrin were significantly upregulated in NSCLC compared with the normal counterparts. Increased ezrin, ezrin(Thr-567), and ezrin(Tyr-353) levels were correlated with the late stage and poor differentiation of NSCLC. However, only ezrin(Thr-567) was correlated with the presence of lymph node metastasis. In regard to survival, only ezrin(Thr-567) was related with the overall survival time of patients with NSCLC, and both ezrin and ezrin(Thr-567) were associated with shortened survival time for patients with early stage NSCLC. CONCLUSIONS: Ezrin and p-ezrin, especially ezrin(Thr-567), may prove to be useful as a novel prognostic biomarker of NSCLC
Effectiveness of a Virtual Reality Head-Mounted Display System-based Developmental Eye Movement Test
By transplanting the Developmental Eye Movement (DEM) test chart to a virtual reality head-mounted display (VR HMD) system, this study sought to evaluate the effectiveness of the DEM test for measuring dynamic visual acuity.Thirty-nine adults aged 20–39 years of both genders were the subjects of the study. After undergoing measurement of their visual function, through medical questionnaire, interpupillary distance, near point of convergence (NPC), near point of accommodation (NPA), and far and near phoria, the correlation between the tests was analyzed performing DEM vertical, horizontal test and VR HMD DEM (VHD) vertical, horizontal test.NPC and NPA decreased significantly after the VHD test, while phoria did not. The horizontal was quicker than the vertical in the DEM test, and vice versa in the VHD test. DEM was quicker than VHD in both the vertical and horizontal directions. There was no notable difference in error frequency between DEM and VHD. In terms of DEM and VHD test, there was no notable difference in the short-range IPD and subjective symptoms of the top 10 and bottom 10 subjects. There was also no notable difference between the exercise and non-exercise groups and the game and non-game groups.The performance time for VHD, in which the chart must be read while moving the body, was longer than that of DEM. Therefore, based on the consistency of the results of both tests and the lack of a difference in error frequency and subjective symptoms, the VHD equipment proposed in this thesis is as effective as dynamic visual acuity measurement equipment. In addition, the lack of a difference between the exercise and non-exercise groups and the game and non-game groups demonstrated that the amount of exercise and game by an ordinary person does not influence their dynamic visual function
ReFine: Re-randomization before Fine-tuning for Cross-domain Few-shot Learning
Cross-domain few-shot learning (CD-FSL), where there are few target samples
under extreme differences between source and target domains, has recently
attracted huge attention. Recent studies on CD-FSL generally focus on transfer
learning based approaches, where a neural network is pre-trained on popular
labeled source domain datasets and then transferred to target domain data.
Although the labeled datasets may provide suitable initial parameters for the
target data, the domain difference between the source and target might hinder
fine-tuning on the target domain. This paper proposes a simple yet powerful
method that re-randomizes the parameters fitted on the source domain before
adapting to the target data. The re-randomization resets source-specific
parameters of the source pre-trained model and thus facilitates fine-tuning on
the target domain, improving few-shot performance.Comment: CIKM 2022 Short; 5 pages, 3 figures, 4 table
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