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11.
Now is the time to refocus efforts in urban research and design. A changing climate and extreme weather events are presenting unique challenges to urban systems around the world. These challenges illuminate the social barriers that accompany disruptive events such as resource inequities and injustices. In this perspective, we provide three research priorities for just and sustainable urban systems that help to address these matters. The three research priorities are: (1) social equity and justice, (2) circularity, and (3) digital twins. Conceptual context and future research directions are provided for each. For social equity and justice, the future directions are mandatory equity analysis and inclusionary practices, understanding and reconciling historical injustices, and intentional integration with diverse community stakeholders. For circularity applications, they are better metrics for integration, more robust evaluation frameworks, and dynamic modeling at multiple spatial and temporal scales. Future directions for digital twins include developing principles to reduce complexity, integrating model and system components, and reducing barriers to data access. These research priorities are core to meeting several of the United Nations Sustainable Development Goals (i.e., 1—No Poverty, 8—Decent Work and Economic Growth, 10—Reduced Inequalities, and 11—Sustainable Cities and Communities). Useful social and technical matters are discussed throughout, where we highlight the importance of prioritizing localized research efforts, provide guidance for community-engaged research and co-development practices, and explain how these priorities interact to align with the evolving field of industrial ecology.  相似文献   
12.
A series of ZnB2O4 phosphors doped with different concentrations of Eu and Dy (0.05 0.1, 0.2, 0.5, 1.0 mol%) and co-doped with Ce (1, 2, 5, 7, 10 mol%) respectively was prepared via the solid-state reaction technique and the thermoluminescence (TL) behaviour of gamma ray-irradiated samples was studied. The synthesized samples were irradiated with γ-rays for the dose range 0.03–1.20 kGy. The TL intensity variations with dose, dopant concentration, and the effect of co-doping were studied. The TL response curves for ZnB2O4:Eu3+ and ZnB2O4:Dy3+, ZnB2O4:Eu3,Ce3+ and ZnB2O4:Dy3+,Ce3+ phosphor were observed. It was revealed that ZnB2O4:Eu3+ showed a linear TL behaviour for the dose 0.03–1.20 kGy and ZnB2O4:Dy3+ showed linearity for the gamma dose range 0.03–0.10 kGy. Furthermore, fading for all the samples was observed to be less than 10% for a storage period of 30 days. In addition to this, the trapping parameters, especially activation energies were evaluated using the Ilich method and the initial rise method. The activation energy values obtained from both methods were in complete agreement with each other.  相似文献   
13.
Metabolic engineering of the pathways of lipid biosynthesis has generated transgenic oilseed crops with enhanced levels of specialty fatty acids of Industrial value. Stearic acid, a 18:0 saturated fatty acid, is one such important fatty acid. Stearoylacyl carrier protein (stearoyl-ACP) desaturase (EC 1.14.99.6) catalyzes the first desaturation step in seed oil biosynthesis and converts stearoyl-ACP to oleoyl-ACP. We have cloned the complete coding region of the gene for this enzyme in Brassica juncea. Based on the sequence information of the gene in B. napus, 27-mer forward and reverse primers were designed each of which incorporated a Sal I restriciton site at the end. The primers were used to fish out the desaturase gene from B. juncea genome by polymerase chain reaction (PCR). The PCR product conformed to the average size of the coding region of the gene in B. napus. The PCR product was cloned in the pGem-T vector. The cloning was reconfirmed by restriction enzyme analysis and by PCR of the recombinant plasmid. The potential use of this gene in molecular farming of designer oilseed brassicas is discussed.  相似文献   
14.
Lipid metabolism in plants provides uncommon opportunities for genetic engineering to produce plant oils suited to a variety of end-uses. These opportunities include improvement of food and nutritional value, creating specialty lipids and feedstocks for high-value products and designing custom-made materials for industry. Genetic engineering intervention for production of novel transgenic plants which elaborate the desired product has graduated from academic exercise to commercial possibilities. It is now realized that transgenic crops can serve as biological factories for upscaling production of premium lipids via molecular farming. This review is an attempt at analyzing the status in this field.  相似文献   
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The seed meal of oleiferous brassicas is an excellent feed concentrate whose nutritional value is impaired by glucosinolates. Glucosinolates and the products of their hydrolytic cleavage are toxic, goitrogenic and reduce palatability because of their pungency. Efforts to develop low-glucosinolate varieties have not been very successful since the genetics of total glucosinolate biosynthesis is complex and highly regulated. This review summarizes information from genetic and plant breeding studies on identification and mapping of the genetic determinants for glucosinolate biosynthesis in Brassicas. Additional options offered by plant biotechnology using genetic engineering tools such as antisense technology and metabolic pathway engineering that could bring down the seed glucosinolate levels have also been highlighted.  相似文献   
17.
Iron supplementation moderates but does not cure the Belgrade anemia   总被引:2,自引:0,他引:2  
Belgrade rats inherit microcytic, hypochromic anemia as an autosomalrecessive trait (gene symbol b). Erythrocytes and tissue are iron deficientin the face of elevated TIBC (total iron binding capacity) and percent ironsaturation; iron injections increased the number of erythrocytes but theirappearance remained abnormal. We have investigated iron supplements toimprove husbandry of b/b rats and to learn more about the underlying defectand its tissue distribution. Weekly IM (intramuscular) injections ofiron–dextran (Imferon at 30 mg kg) improved the anemia but did not alter thered cell morphology. Certain diets also improved the health of b/b rats whencompared to standard rat chows by the criteria of weight, survival toadulthood, hematology and reproduction. The critical nutritional factorturned out to be iron bioavailability, with ferrous iron added to the dietimproving the health of Belgrade rats without affecting the underlyingerythroid defect. Tissue iron measurements after dietary or parenteralsupplementation confirmed the iron deficient status of untreated b/b rats andestablished that dietary ferrous iron partially relieved this deficiency,with injections leading to greater amounts of tissue iron. Serum iron andTIBC were also found to be elevated in untreated b/b rats, with dietarysupplementation decreasing but not eliminating the elevation in TIBC. Thesestudies indicate that iron supplements can improve the health of b/b ratswithout altering the underlying defect and also suggest that the mutationcould alter iron uptake in the GI (gastrointestinal) tract.  相似文献   
18.
Proteolytic thermophilic bacterial cultures (171 strains) were isolated from different milk and milk products. After screening these isolates for protease production in a liquid medium, fifty that exhibited enzyme activity in excess of 100 units/ml were selected and identified. Twenty-nine were Bacillus stearothermophilus (constituting 58% of the total), twelve were B. coagulans , five were B. circulans and four were B. licheniformis . Skim milk powder contributed the maximum number of B. stearothermophilus (64.7%) followed by raw milk (63.2%) and pasteurized milk (44.4%). When the culture supernatant liquids from the selected isolates were given heat treatment, five cultures retained 100% protease activity at 65°C for 30 min. Protease of B. stearothermophilus RM-67 had the maximum heat resistance because it retained 87.5% of its activity at 70°C for 30 min.  相似文献   
19.
Summary Primary and passaged cultures of normal colon epithelial cells, derived from human fetuses (13 to 17 wk of conceptual age) have been established. These cultures have been passaged 16 times thus far. The cultures have been initiated and maintained in medium consisting of 50% Dulbecco's minimum essential medium and 50% Ham's F12 medium and supplemented with antibiotics (penicillin, 100 U/ml; streptomycin, 100 μg/ml); ascorbic acid, 40 μg/ml;l-isoleucine, 50 μg/ml; epidermal growth factor, 20 ng/ml; insulin, 5 μg/ml; cholera toxin, 5 ng/ml; transferrin, 1 μg/ml; fetal bovine serum (10%); and HEPES, 25 mM final concentration, and incubated at 37°C in humidified gas containing 5% CO2: 95% air. The cellular and subcellular characteristics of primary and passaged cultures were defined using light microscopy and scanning and transmission electron microscopy. The cells exhibited microvilli on cell surfaces and showed junctional complexes and interdigitations between cells. Indented nuclei with dense chromatin and marginated heterochromatin, numerous mitochondria, rough endoplasmic reticulum, polysomes, and extensive Golgi zones were conspicuous. Also, periodic acid Schiff's reagent-positive staining of the cells suggests the active synthesis of complex mucopolysaccharides in the cytoplasm. This study was supported by USPHS Grant CA-30185 from the National Large Bowel Cancer Project, National Cancer Institute.  相似文献   
20.
An experimental model of protein calorie malnutrition (PCM) was created in young rhesus monkeys. Ulnar and tibial nerves from six monkeys with PCM, six rehabilitated and 12 control monkeys were studied for lipid composition and activity of myelin marker enzyme. Total lipids, myelin marker lipids and activity of myelin marker enzyme, 2', 3'-cyclic nucleotide 3' - phosphohydrolase were decreased, while esterified cholesterol and free fatty acids were increased in PCM as compared to controls. There was partial recovery in myelin marker lipids and complete restoration of other lipids on nutritional rehabilitation.  相似文献   
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