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61.
Overexploitation of common-pool resources, resulting from uncooperative harvest behavior, is a major problem in many social-ecological systems. Feedbacks between user behavior and resource productivity induce non-linear dynamics in the harvest and the resource stock that complicate the understanding and the prediction of the co-evolutionary system. With an adaptive model constrained by data from a behavioral economic experiment, we show that users’ expectations of future pay-offs vary as a result of the previous harvest experience, the time-horizon, and the ability to communicate. In our model, harvest behavior is a trait that adjusts to continuously changing potential returns according to a trade-off between the users’ current harvest and the discounted future productivity of the resource. Given a maximum discount factor, which quantifies the users’ perception of future pay-offs, the temporal dynamics of harvest behavior and ecological resource can be predicted. Our results reveal a non-linear relation between the previous harvest and current discount rates, which is most sensitive around a reference harvest level. While higher than expected returns resulting from cooperative harvesting in the past increase the importance of future resource productivity and foster sustainability, harvests below the reference level lead to a downward spiral of increasing overexploitation and disappointing returns. 相似文献
62.
Defranoux Fanny Noè Simona Cutignano Adele Casapullo Agostino Ciavatta Maria Letizia Carbone Marianna Mollo Ernesto Gianguzza Paola 《Aquatic Ecology》2022,56(2):447-457
Aquatic Ecology - Marine invasive species and their bioactive metabolites have become critical ecological issues in the Mediterranean Sea. In particular, the highly invasive green algae Caulerpa... 相似文献
63.
Federico Fogolari Lidia Pieri Agostino Dovier Luca Bortolussi Gilberto Giugliarelli Alessandra Corazza Gennaro Esposito Paolo Viglino 《BMC structural biology》2007,7(1):15
Background
Reduced representations of proteins have been playing a keyrole in the study of protein folding. Many such models are available, with different representation detail. Although the usefulness of many such models for structural bioinformatics applications has been demonstrated in recent years, there are few intermediate resolution models endowed with an energy model capable, for instance, of detecting native or native-like structures among decoy sets. The aim of the present work is to provide a discrete empirical potential for a reduced protein model termed here PC2CA, because it employs a PseudoCovalent structure with only 2 Centers of interactions per Amino acid, suitable for protein model quality assessment. 相似文献64.
Pasquinucci L Parenti C Turnaturi R Aricò G Marrazzo A Prezzavento O Ronsisvalle S Georgoussi Z Fourla DD Scoto GM Ronsisvalle G 《Life sciences》2012,90(1-2):66-70
AimsPowerful analgesics relieve pain primarily through activating mu opioid receptor (MOR), but the long-term use of MOR agonists, such as morphine, is limited by the rapid development of tolerance. Recently, it has been observed that simultaneous stimulation of the delta opioid receptor (DOR) and MOR limits the incidence of tolerance induced by MOR agonists. 3-[(2R,6R,11R)-8-hydroxy-6,11-dimethyl-1,4,5,6-tetrahydro-2,6-methano-3-benzazocin-3(2H)-yl]-N-phenylpropanamide (LP1) is a centrally acting agent with antinociceptive activity comparable to morphine and is able to bind and activate MOR and DOR. The aim of this work was to evaluate and compare the induction of tolerance to antinociceptive effects from treatment with LP1 and morphine.Main methodsHere, we evaluated the pharmacological effects of LP1 administered at a dose of 4 mg/kg subcutaneously (s.c.) twice per day for 9 days to male Sprague–Dawley rats. In addition, the LP1 mechanism of action was assessed by measurement of LP1-induced [35S]GTPγS binding to the MOR and DOR.Key findingsData obtained from the radiant heat tail flick test showed that LP1 maintained its antinociceptive profile until the ninth day, while tolerance to morphine (10 mg/kg s.c. twice per day) was observed on day 3. Moreover, LP1 significantly enhanced [35S]GTPγS binding in the membranes of HEK293 cells expressing either the MOR or the DOR.SignificanceLP1 is a novel analgesic agent for chronic pain treatment, and its low tolerance-inducing capability may be correlated with its ability to bind both the MOR and DOR. 相似文献
65.
66.
Agostino Sorgonà Giovanni Cacco Lugi Di Dio Wolfgang Schmidt Paula Jay Perry Maria Rosa Abenavoli 《Acta Physiologiae Plantarum》2010,32(4):683-693
Spatial–temporal variation of the regulation and the kinetics of net nitrate (NO3
−) uptake rate (NNUR) along the tap root of Citrus aurantium L. were analysed. Suberin incrustation in the peripheral cell layers and plasma membrane (PM) H+-ATPase localisation, anatomical and physiological factors involved in NO3
− uptake were also investigated. The results clearly indicated a spatially uniform distribution of the regulation process,
accompanied by a temporal heterogeneous pattern of the kinetics of NO3
− uptake along citrus tap root. In particular, kinetic analysis had a biphasic pattern, saturating (high affinity transport
system) and linear (low affinity transport system), in response to increasing external NO3
− concentrations in each root region, where 200 μM NO3
− represented the threshold separating these two systems. Kinetic parameters, K
m and V
max, clearly indicated that apical segments reached the maximum value of induction before basal segments. Hence, the apical root
zones, early exhibiting the maximum of potential capacity to absorb the NO3
−, could be considered more efficient than basal root segments for acquiring NO3
− from external solution. Suberin incrustations in the hypodermal cell layer, characterised by uniform fluorescence intensity
among the root segments, could be responsible for the unchanged NNUR, while the PM H+-ATPase could explain the temporal pattern of NNUR. 相似文献
67.
Gabrielli E Ferraioli G Ferraris L Riva A Galli M Filice C Gervasoni C 《The new microbiologica》2010,33(3):263-265
Enfuvirtide is a large protein that should be injected subcutaneously to ensure an appropriate absorption. Here we report the case of a transgender HIV-positive patient receiving enfuvirtide with an individualized background regimen of antiretroviral drugs, who had previously undergone liquid silicone oil injections. We performed US scan to detect silicone-free areas for following enfuvirtide injections. US can be useful in the correct management of those patients with liquid silicone oil soft tissue augmentation who require subcutaneously injected drugs. 相似文献
68.
Vito G. D’Agostino Anna Minoprio Paola Torreri Ilaria Marinoni Cecilia Bossa Tamara C. Petrucci Alessandra M. Albertini Guglielmina N. Ranzani Margherita Bignami Filomena Mazzei 《DNA Repair》2010,9(6):700-707
The MUTYH DNA glycosylase specifically removes adenine misincorporated by replicative polymerases opposite the oxidized purine 8-oxo-7,8-dihydroguanine (8-oxoG). A defective protein activity results in the accumulation of G > T transversions because of unrepaired 8-oxoG:A mismatches. In humans, MUTYH germline mutations are associated with a recessive form of familial adenomatous polyposis and colorectal cancer predisposition (MUTYH-associated polyposis, MAP). Here we studied the repair capacity of the MUTYH variants R171W, E466del, 137insIW, Y165C and G382D, identified in MAP patients. Following expression and purification of human proteins from a bacterial system, we investigated MUTYH incision capacity on an 8-oxoG:A substrate by standard glycosylase assays. For the first time, we employed the surface plasmon resonance (SPR) technology for real-time recording of the association/dissociation of wild-type and MUTYH variants from an 8-oxoG:A DNA substrate. When compared to the wild-type protein, R171W, E466del and Y165C variants showed a severe reduction in the binding affinity towards the substrate, while 137insIW and G382D mutants manifested only a slight decrease mainly due to a slower rate of association. This reduced binding was always associated with impairment of glycosylase activity, with adenine removal being totally abrogated in R171W, E466del and Y165C and only partially reduced in 137insIW and G382D. Our findings demonstrate that SPR analysis is suitable to identify defective enzymatic behaviour even when mutant proteins display minor alterations in substrate recognition. 相似文献
69.
Manuela Contin Susan Mohamed Carmina Candela Fiorenzo Albani Roberto Riva Agostino Baruzzi 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2010,878(3-4):461-465
We present an implementation of a method we previously reported allowing the newer antiepileptic drugs (AEDs) rufinamide (RFN) and zonisamide (ZNS) to be simultaneously determined with lamotrigine (LTG), oxcarbazepine's (OXC) main active metabolite monohydroxycarbamazepine (MHD) and felbamate (FBM) in plasma of patients with epilepsy using high performance liquid chromatography (HPLC) with UV detection. Plasma samples (250 μL) were deproteinized by 1 mL acetonitrile spiked with citalopram as internal standard (I.S.). HPLC analysis was carried out on a Synergi 4 μm Hydro-RP, 250 mm × 4.6 mm I.D. column. The mobile phase was a mixture of potassium dihydrogen phosphate buffer (50 mM, pH 4.5), acetonitrile and methanol (65:26.2:8.8, v/v/v) at an isocratic flow rate of 0.8 mL/min. The UV detector was set at 210 nm. The chromatographic run lasted 19 min. Commonly coprescribed AEDs did not interfere with the assay. Calibration curves were linear for both AEDs over a range of 2–40 μg/mL for RFN and 2–80 μg/mL for ZNS. The limit of quantitation was 2 μg/mL for both analytes and the absolute recovery ranged from 97% to 103% for RFN, ZNS and the I.S. Intra- and interassay precision and accuracy were lower than 10% at all tested concentrations. The present study describes the first simple and validated method for RFN determination in plasma of patients with epilepsy. By grouping different new AEDs in the same assay the method can be advantageous for therapeutic drug monitoring (TDM). 相似文献
70.