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1.
The sciences of industrial ecology, complex systems, and adaptive management are intimately related, since they deal with flows and dynamic interdependencies between system elements of various kinds. As such, the tool kit of complex systems science could enrich our understanding of how industrial ecosystems might evolve over time. In this article, I illustrate how an important tool of complex systems science— agent-based simulation —can help to identify those potential elements of an industrial ecosystem that could work together to achieve more eco-efficient outcomes. For example, I show how agent-based simulation can generate cost-efficient energy futures in which groups of firms behave more eco-efficiently by introducing strategically located clusters of renewable, low-emissions, distributed generation. I then explain how role-playing games and participatory modeling can build trust and reduce conflict about the sharing of common-pool resources such as water and energy among small clusters of evolving agents. Collective learning can encourage potential industrial partners to gradually cooperate by exchanging by-products and/or sharing common infrastructure by dint of their close proximity. This kind of coevolutionary learning, aided by participatory modeling, could help to bring about industrial symbiosis.  相似文献   

2.
We have used a 692 case dataset, collected retrospectively by a single observer, to develop decision support systems for the cytodiagnosis of fine needle aspirates of breast lesions. In this study, we use a 322 case dataset that was prospectively collected by multiple observers in a working clinical environment to test two predictive systems, using logistic regression and the multilayer perceptron (MLP) type of neural network. Ten observed features and the patient age were used as input features. The systems were developed using a training set and test set from the single observer dataset and then applied to the multiple observer dataset. For the independent test cases from the single observer dataset, with a threshold set for no false positives on the training set, logistic regression produced a sensitivity of 82% (95% confidence interval 73-91) and a predictive value of a positive result (PV +) of 98% (95-99), the values for the MLP were 79% (69-89) and 100%, respectively. However the performance on the prospective multiple observer dataset was much worse, with a sensitivity of 72% (65-80), and PV + of 97% (94-99) for logistic regression and 67% (60-75) and 91% (85-97) for the MLP. These results suggest that there is considerable interobserver variability for the defined features and that this system is unsuitable for further development in the clinical environment unless this problem can be overcome.  相似文献   

3.
地理信息系统及其在动物空间行为研究中的应用   总被引:1,自引:0,他引:1  
空间属性是动物行为的重要特征,也是行为生态学研究中必须要面对的难题之一。地理信息系统(Geographic Information System,GIS)具有强大的空间分析功能,它在动物行为生态学研究中得到了越来越广泛的应用,如生境选择、领域分析、迁徙路线、活动节律等。本文较系统地阐述了GIS的原理以及在行为生态学研究中所涉及的基本概念和原理,对近年来利用GIS进行的行为生态学研究做了回顾和总结,并对其未来的发展进行了展望。  相似文献   

4.
Two new manganese(II) complexes, [Mn(L1)(L1H)(ClO4)(H2O)][ClO4]2·0.5CH3CN·H2O (1) [L1 = trans-(±)2-(2,5-di(pyridin-2-yl)-4,5-dihydro-1H-imidazol-4-yl)pyridine)] and [Mn2(μ-L2)2(H2O)3(CH3CN)3][ClO4]4·2CH3CN (2) [L2 = cis-(±)2-(2,5-di(pyridin-2-yl)-4,5-dihydro-1H-imidazol-4-yl)pyridine)], have been prepared and examined by single-crystal X-ray diffraction analysis, showing that complex 1 is a mononuclear compound, whereas complex 2 is a dinuclear species. The cis/trans isomers L1 and L2 have similar coordination properties, but behave as bidentate and tridentate chelating ligands, respectively, giving distorted octahedral metal coordination geometries. X-ray diffraction studies revealed that the molecular and crystal structures are stabilized by a series of intra- and intermolecular interactions. In both cases extended supramolecular networks are generated, in compound 1 through O-H···O, O-H···N, N-H···O, N-H···N, C-H···O, C-H···N, C-H···π and π···π interactions, and in compound 2 through O-H···O, O-H···N, C-H···O and π···π interactions. The observed structural differences between the two metal complexes might be a consequence of these stabilizing effects.  相似文献   

5.
The localization of -D-galactose, N-acetyl-D-galactosamine, and N-acetyl-D-glucosamine sugar residues of glycoconjugates in the vomeronasal organ, olfactory mucosa, and septal organ in the nasal mucosae of rats was investigated using lectinohistochemical techniques combined with bright-field, epifluorescence, and confocal laser scanning microscopy. Glycoconjugates in the mucomicrovillar complex of the vomeronasal organ contained all the sugar residues investigated, whereas glycoconjugates in the mucociliary complex of the olfactory mucosa and septal organ contained only N-acetyl-D-glucosamine. Vomeronasal receptor neurons expressed glycoconjugates with terminal -D-galactose and -N-acetyl-D-galactosamine, and N-acetyl-D-glucosamine residues, whereas olfactory and septal receptor neurons expressed glycoconjugates with only N-acetyl-D-glucosamine residues. Secretory granules of glands of the vomeronasal organ contained glycoconjugates with terminal -D-galactose and N-acetyl-D-galactosamine, and N-acetyl-D-glucosamine, whereas those of the Bowman's glands and glands of septal organ contained glycoconjugates with only internal N-acetyl-D-glucosamine residues. The results demonstrate that the glycoconjugates expressed by vomeronasal receptor neurons and glands contain terminal -D-galactose and -N-acetyl-D-galactosamine sugar residues that are not expressed by analogous cells in the olfactory mucosa and septal organ.  相似文献   

6.
The interaction between copper (II) 2-oxo-propionic acid salicyloyl hydrazone (CuIIL) and bovine serum albumin (BSA) under physiological conditions was investigated by the methods of fluorescence spectroscopy, UV-Vis absorption, and circular dichroism spectroscopy. Fluorescence data showed that the fluorescence quenching of BSA by CuIIL was the result of the formation of the BSA–CuIIL complex. The apparent binding constants (K a) between CuIIL and BSA at four different temperatures were obtained according to the modified Stern–Volmer equation. The thermodynamic parameters, enthalpy change (ΔH) and entropy change (ΔS), for the reaction were calculated to be ?80.79 kJ mol?1 and ?175.48 J mol?1 K?1 according to van’t Hoff equation. The results indicated that van der Waals force and hydrogen bonds were the dominant intermolecular force in stabilizing the complex. The binding distance (r) between CuIIL and the tryptophan residue of BSA was obtained to be 4.1 nm according to Förster’s nonradioactive energy transfer theory. The conformational investigation showed that the application of CuIIL increased the hydrophobicity of amino acid residues and decreased the α-helical content of BSA (from 62.71% to 37.31%), which confirmed some microenvironmental and conformational changes of BSA molecules.  相似文献   

7.
Shigeru Itoh 《BBA》1984,766(2):464-471
Large blue-shifts of carotenoid absorption bands were induced by dark addition of a hydrophobic anion, tetraphenylborate, in chromatophores and cell membranes of photosynthetic bacteria, Rhodopseudomonas sphaeroides and Rhodopseudomonas capsulata. Tetraphenylborate also induced a red-shift of the 850 nm absorption band and a blue-shift and broadening of the 800 nm band of bacteriochlorophyll. From the analysis of the relation between the magnitude and isosbestic wavelength of the absorbance changes the tetraphenylborate-induced carotenoid band shift were assumed to reflect the change of local electrical field close to each carotenoid molecule which exists as a minor pool on the light-harvesting pigment-protein complex II (LHC II). Absorbance changes of carotenoid and chlorophylls were also induced by tetraphenylborate in membranes of spinach chloroplasts.  相似文献   

8.
Of the inhibitory checkpoints in the immune system, programmed death 1 (PD-1) is one of the most promising targets for cancer immunotherapy. The anti-PD-1 antibodies currently approved for clinical use or under development bind to human PD-1 (hPD-1), but not murine PD-1. To facilitate studies in murine models, we developed a functional antibody against both human and murine PD-1, and compared the epitopes of such antibody to a counterpart that only bound to hPD-1. To quickly identify the epitopes of the 2 antibodies, we used alanine scanning and mammalian cell expression cassette. The epitope identification was based on PD-1-binding ELISA and supported by affinity ranking of surface plasmon resonance results. The hPD-1 epitopes of the 2 functional antibodies were also compared with the binding region on hPD-1 that is responsible for PD-L1 interaction. In silico modeling were conducted to explain the different binding modes of the 2 antibodies, suggesting a potential mechanism of the antibody cross-species binding.  相似文献   

9.
Burkholderia cenocepacia is an opportunistic pathogen threatening patients with cystic fibrosis. Flagella are required for biofilm formation, as well as adhesion to and invasion of epithelial cells. Recognition of flagellin via the Toll-like receptor 5 (TLR5) contributes to exacerbate B. cenocepacia-induced lung epithelial inflammatory responses. In this study, we report that B. cenocepacia flagellin is glycosylated on at least 10 different sites with a single sugar, 4,6-dideoxy-4-(3-hydroxybutanoylamino)-d-glucose. We have identified key genes that are required for flagellin glycosylation, including a predicted glycosyltransferase gene that is linked to the flagellin biosynthesis cluster and a putative acetyltransferase gene located within the O-antigen lipopolysaccharide cluster. Another O-antigen cluster gene, rmlB, which is required for flagellin glycan and O-antigen biosynthesis, was essential for bacterial viability, uncovering a novel target against Burkholderia infections. Using glycosylated and nonglycosylated purified flagellin and a cell reporter system to assess TLR5-mediated responses, we also show that the presence of glycan in flagellin significantly impairs the inflammatory response of epithelial cells. We therefore suggest that flagellin glycosylation reduces recognition of flagellin by host TLR5, providing an evasive strategy to infecting bacteria.  相似文献   

10.
UBE2W ubiquitinates N termini of proteins rather than internal lysine residues, showing a preference for substrates with intrinsically disordered N termini. The in vivo functions of this intriguing E2, however, remain unknown. We generated Ube2w germ line KO mice that proved to be susceptible to early postnatal lethality without obvious developmental abnormalities. Although the basis of early death is uncertain, several organ systems manifest changes in Ube2w KO mice. Newborn Ube2w KO mice often show altered epidermal maturation with reduced expression of differentiation markers. Mirroring higher UBE2W expression levels in testis and thymus, Ube2w KO mice showed a disproportionate decrease in weight of these two organs (∼50%), suggesting a functional role for UBE2W in the immune and male reproductive systems. Indeed, Ube2w KO mice displayed sustained neutrophilia accompanied by increased G-CSF signaling and testicular vacuolation associated with decreased fertility. Proteomic analysis of a vulnerable organ, presymptomatic testis, showed a preferential accumulation of disordered proteins in the absence of UBE2W, consistent with the view that UBE2W preferentially targets disordered polypeptides. These mice further allowed us to establish that UBE2W is ubiquitously expressed as a single isoform localized to the cytoplasm and that the absence of UBE2W does not alter cell viability in response to various stressors. Our results establish that UBE2W is an important, albeit not essential, protein for early postnatal survival and normal functioning of multiple organ systems.  相似文献   

11.
Abstract

The effect of pH and temperature on the apparent association equilibrium constant (Ka) for the binding of the recombinant proteinase inhibitor eglin c (eglin c), of the soybean Bowman-Birk proteinase inhibitor (BBI) and of its chymotrypsin and trypsin inhibiting fragments (F-C and F-T, respetively) to Leuproteinase, the leucine specific serine proteinase from spinach (Spinacia oleracea L.) leaves, has been investigated. On lowering the pH from 9.5 to 4.5, values of Ka (at 21°C) for complex formation decrease thus reflecting the acidic pK-shift of the hystidyl catalytic residue from ~6.9, in the free Leu-proteinase, to ~5.1, in the enzyme: inhibitor adducts. At pH 8.0, values of the apparent thermodynamic parameters for the proteinase:inhibitor complex formation are: Leu-proteinase:eglin c - Ka = 2.2 × 1011 M-1, δG°= - 64kJ/mol, δH° = + 5.9kJ/mol, and δS° = + 240J/molK; Leu-proteinase:BBI - Ka = 3.2 × 1010 M-1, δG° = - 59kJ/mol, δH°= + 8.8kJ/mol, and δS° = + 230J/molK; and Leu-proteinase:F-C - Ka = 1.1 × 106 M-1, δG°= - 34kJ/mol, δH° = + 18J/mol, and δS° = + 180J/molK (values of Ka, δG° and δS° were obtained at 21.0°C; values of δH° were temperature-independent over the range explored, i.e. between 10.0°C and 40.0°C). F-T does not inhibit Leu-proteinase up to an inhibitor concentration of 1.0 × 10-3 M, suggesting that the upper limit of Ka is 1 × 102 M-1. Considering the known molecular models, the observed binding behaviour of eglin c, BBI, F-C and F-T to Leu-proteinase has been related to the inferred stereochemistry of the enzyme/inhibitor contact region  相似文献   

12.
Shigeru Itoh 《BBA》1978,504(2):324-340
A hypothesis is proposed to explain the change in the apparent rate constant for the reaction between the primary electron acceptor of System II situated in the thylakoid membrane and the artificial electron acceptors added in the medium. Dark oxidation rate of the primary acceptor by artificial electron acceptors was monitored by measuring the induction of chlorophyll fluorescence in the presence of an electron transport inhibitor, 3-(3′,4′-dichlorophenyl)-1,1-dimethylurea, in spinach chloroplasts. The apparent rate constant for the oxidation changed widely when the medium pH or salt concentrations were varied, or ionic detergents were added. The change was quantitatively ascribed (1) to the change in the local concentration of electron acceptors at the thylakoid surface due to the electrical potential difference between the surface and the bulk aqueous phase (Gouy-Chapman diffuse double layer theory) and (2) to the situation whereby the apparent rate constant is determined with respect to concentration in the bulk phase.Values for the surface potential in the vicinity of System II were estimated from the change in the apparent rate constant under various conditions. The results closely agreed with those obtained previously from the rate constant of the dark step of the System II-dependent Hill reaction with ferricyanide (Itoh, S. (1978) Plant Cell Physiol. 19, 149–166).Application of the hypothesis to various reactions between the added ionic reagents and the endogenous components in the membrane or between the endogenous components situated in different parts of the membrane is discussed.  相似文献   

13.
Exposure of 25 °C-grown, seven-day-old rice seedlings to mild heat stress of 40 °C for 24 h in dark did not cause any change in protein or pigment content of the thylakoids, but produced major disorganization of chloroplast ultrastructure. This heat induced disorganization of thylakoid structure/organization caused significant (65 percnt;) loss in PSII activity, slight loss in PSI activity, and brought about a decrease in relative quantum efficiency of PSII. The herbicide 14C atrazine binding assay revealed a decreased number of binding sites of the herbicide and altered the herbicide dissociation constant, suggesting that the heat induced disorganization of the thylakoids affects the acceptor side of PSII. Cation induced Chla fluorescence analyses at room temperature and low temperature indicated thatin vivo heat exposure of rice seedlings altered the extent of energy transfer in favor of PSI. Immunoblotting analysis of several PSII polypeptides such as D1/D2 reaction dimer and Cyt b559 showed no major changes due to mild heat exposure except for the PSII core antenna polypeptide (CP43), which could reflect the reduction in PSII activity observed in light saturation studies. Similarly, haeme staining did not indicate any change in other cytochrome related polypeptides. Our results therefore clearly suggest thatin vivo exposure of rice seedlings to elevated (40 °C) temperature caused thylakoid structural disorganization, and this disorganization of some of the thylakoid complexes resulted in a loss in thylakoid photochemical function.  相似文献   

14.
1. 125I-Endothelin (ET)-1 binding to the rat anterior pituitary gland was saturable and single, with a K d of 71 pM and a B max of 120 fmol/mg.2. When 1.0 M BQ-123 (ETA antagonist) was added to the incubation buffer, the binding parameters were 8.3 pM and 8.0 fmol/mg, whereas 10 nM sarafotoxin S6c (ETBagonist) exerted little change in these binding parameters (K d,72pM;B max, 110 fmol/mg).3. ETB receptor-related compounds such as sarafotoxin S6c, ET-3, IRL1620, and BQ-788 competitively inhibited 125I-ET-1 binding, only when 1.0 M BQ-123 was present in the incubation buffer.4. Thus, the ETB receptor is capable of binding ET-1 when the ETA receptor is being occupied by BQ-123. A collaboration mechanism between the ETA and the ETB receptor may function in the recognition of ET-1, a typical bivalent ligand.  相似文献   

15.
Experiments dedicated to gaining an understanding of the mechanism underlying the orderly, sequential association of elongation factor Tu (EF-Tu) and elongation factor G (EF-G) with the ribosome during protein synthesis were undertaken. The binding of one EF is always followed by the binding of the other, despite the two sharing the same—or a largely overlapping—site and despite the two having isosteric structures. Aminoacyl-tRNA, peptidyl-tRNA, and deacylated-tRNA were bound in various combinations to the A-site, P-site, or E-site of ribosomes, and their effect on conformation in the peptidyl transferase center, the GTPase-associated center, and the sarcin/ricin domain (SRD) was determined. In addition, the effect of the ribosome complexes on sensitivity to the ribotoxins sarcin and pokeweed antiviral protein and on the binding of EF-G•GTP were assessed. The results support the following conclusions: the EF-Tu ternary complex binds to the A-site whenever it is vacant and the P-site has peptidyl-tRNA; and association of the EF-Tu ternary complex is prevented, simply by steric hindrance, when the A-site is occupied by peptidyl-tRNA. On the other hand, the affinity of the ribosome for EF-G•GTP is increased when peptidyl-tRNA is in the A-site, and the increase is the result of a conformational change in the SRD. We propose that peptidyl-tRNA in the A-site is an effector that initiates a series of changes in tertiary interactions between nucleotides in the peptidyl transferase center, the SRD, and the GTPase-associated center of 23S rRNA; and that the signal, transmitted through a transduction pathway, informs the ribosome of the position of peptidyl-tRNA and leads to a conformational change in the SRD that favors binding of EF-G.  相似文献   

16.
Rémy Beauchemin 《BBA》2007,1767(7):905-912
Polyamines are implicated in plant growth and stress response. However, the polyamines spermine and spermidine were shown to elicit strong inhibitory effects in photosystem II (PSII) submembrane fractions. We have studied the mechanism of this inhibitory action in detail. The inhibition of electron transport in PSII submembrane fractions treated with millimolar concentrations of spermine or spermidine led to the decline of plastoquinone reduction, which was reversed by the artificial electron donor diphenylcarbazide. The above inhibition was due to the loss of the extrinsic polypeptides associated with the oxygen evolving complex. Thermoluminescence measurements revealed that charge recombination between the quinone acceptors of PSII, QA and QB, and the S2 state of the Mn-cluster was abolished. Also, the dark decay of chlorophyll fluorescence after a single turn-over white flash was greatly retarded indicating a slower rate of QA reoxidation.  相似文献   

17.
RIG-I (retinoic acid-inducible gene I) is an essential cytosolic pathogen recognition receptor that binds to a variety of viral RNA or DNA to induce type I interferons. In the present study, insert–deletion polymorphisms in promoter and introns of CiRIG-I (Ctenopharyngodon idella RIG-I) were explored, their associations with resistance/susceptibility to grass carp reovirus (GCRV) were analyzed. To this end, genomic sequence of CiRIG-I gene was obtained, and twenty pairs of primers were prepared for the detection of insert–deletion polymorphisms. Five insert–deletion mutations were found, a 2-bp mutation and an 8-bp mutation existed in the promoter and other three sizes in 74 bp, 146 bp and 53 bp were sited in the intron 8. After a challenge experiment, only the genotype and allele of − 740 insert–deletion mutation in the promoter and allele of 6804 insert–deletion mutation were significantly associated with resistance/susceptibility to GCRV among the five mutations (P < 0.05). To further identify this correlation, another independent challenge test was carried out. The result revealed that the cumulative mortality in ins/ins genotype individuals (43.75%) at − 740 insert–deletion mutation was significantly lower than that in ins/del (72.09%) and del/del (74.19%) genotypes (P < 0.05). Linkage disequilibrium and haplotype analysis showed 6610 insert–deletion mutation and 6804 insert–deletion mutation were linkage disequilibrium. The haplotype ins–ins (6610ins–6804ins) was significantly susceptible to GCRV, and ins–del (6610ins–6804del) was significantly resistant to GCRV (P < 0.05). Those could be potential gene markers for the future molecular selection of strains that are resistant to GCRV.  相似文献   

18.
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