INTRODUCTION: Nicotine is a substance associated with rewarding and abusive effects. The rewarding effects of nicotine are thought to be due to dopamine signaling, which is negatively controlled ...through peroxisome proliferator-activated receptors (PPARs). Docosahexaenoic acid (DHA), also known as omega-3, can trigger the peroxisomal β-oxidation enzymes through PPARs. In this study, we planned to examine the effect of DHA on the rewarding properties of nicotine-induced conditioned place preference (CPP) in male rats. METHODS: CPP was established by giving male rats an intraperitoneal injection of nicotine (0.5 mg/kg). The effects of PPAR agonist DHA on the rewarding properties of nicotine were evaluated with the administration of DHA (150 mg/kg and 250 mg/kg, p.o.) or saline 30 min prior to nicotine injection. RESULTS: The present finding confirms that DHA attenuated nicotine acquisition (150 and 250 mg/kg, p<0.01) and failed to produce CPP or/and conditioned place aversion. DISCUSSION AND CONCLUSION: These findings could be a bridge from bench to bedside as DHA may be helpful as an adjuvant for smoking cessation; however, these are the preliminary results, and further research is needed to illuminate this feature completely.
This study was aimed to evaluate the involvement of CB2 cannabinoid receptors (CB2r) in the rewarding, reinforcing and motivational effects of nicotine. Conditioned place preference (CPP) and ...intravenous self-administration experiments were carried out in knockout mice lacking CB2r (CB2KO) and wild-type (WT) littermates treated with the CB2r antagonist AM630 (1 and 3 mg/kg). Gene expression analyses of tyrosine hydroxylase (TH) and α3- and α4-nicotinic acetylcholine receptor subunits (nAChRs) in the ventral tegmental area (VTA) and immunohistochemical studies to elucidate whether CB2r colocalized with α3- and α4-nAChRs in the nucleus accumbens and VTA were performed. Mecamylamine-precipitated withdrawal syndrome after chronic nicotine exposure was evaluated in CB2KO mice and WT mice treated with AM630 (1 and 3 mg/kg). CB2KO mice did not show nicotine-induced place conditioning and self-administered significantly less nicotine. In addition, AM630 was able to block (3 mg/kg) nicotine-induced CPP and reduce (1 and 3 mg/kg) nicotine self-administration. Under baseline conditions, TH, α3-nAChR, and α4-nAChR mRNA levels in the VTA of CB2KO mice were significantly lower compared with WT mice. Confocal microscopy images revealed that CB2r colocalized with α3- and α4-nAChRs. Somatic signs of nicotine withdrawal (rearings, groomings, scratches, teeth chattering, and body tremors) increased significantly in WT but were absent in CB2KO mice. Interestingly, the administration of AM630 blocked the nicotine withdrawal syndrome and failed to alter basal behavior in saline-treated WT mice. These results suggest that CB2r play a relevant role in the rewarding, reinforcing, and motivational effects of nicotine. Pharmacological manipulation of this receptor deserves further consideration as a potential new valuable target for the treatment of nicotine dependence.
Network marketing is a trading technique that provides companies with the opportunity to increase sales. With the increasing number of Internet-based purchases, several threats are increasingly ...observed in this field, such as user privacy violations, company owner (CO) fraud, the changing of sold products’ information, and the scalability of selling networks. This study presents the concept of a blockchain-based market called ACR-MLM that functions based on the multi-level marketing (MLM) model, through which registered users receive anonymous and confidential rewards for their own and their subgroups’ sales. Applying a public blockchain as the ACR-MLM framework’s infrastructure solves existing problems in MLM-based markets, such as CO fraud (against the government or its users), user privacy violations (obtaining their real names or subgroup users), and scalability (when vast numbers of users have been registered). To provide confidentiality and scalability to the ACR-MLM framework, hierarchical identity-based encryption (HIBE) was applied with a functional encryption (FE) scheme. Finally, the security of ACR-MLM is analyzed using the random oracle (RO) model and then evaluated.
The neotropical orchid genus Catasetum embraces about 180 species that produce perfume as reward for pollinators (i.e. male euglossine bees). Among the ca. 1000 perfume‐rewarding plants, Catasetum ...species are the best studied with respect to their natural history. Nevertheless, the pollination ecology of most species (> 80%) remains unknown. Here, we investigated the pollination ecology and floral scent chemistry of C. galeritum, a rare species endemic to the poorly investigated Brazilian Amazon. Flowers of C. galeritum were visited only by male bees of Eufriesea superba. Its perfume bouquet was composed of six volatiles, with 1,4‐dimethoxybenzene accounting for about 85% of the total scent discharge. Curiously, this compound is a potent attractant of more than 40 euglossine species. The absence of euglossine species other than Ef. superba on flowers of C. galeritum might be, therefore, be mediated by a modifier effect of another compound(s) in its floral scent bouquet.
Catasetum is one of the best studied genus of perfume‐rewarding orchids with respect to its natural history. Nevertheless, the pollination ecology of most species (>80%) remains unknown. In this study, we provide for the first time information on the pollinators and floral scent chemistry of Catasetum galeritum, a rare species endemic to the poorly investigated Brazilian Amazon.
A large suite of floral signals, and environmental and biotic characteristics influence the behavior of pollinators, affecting the female success of food‐deceptive orchids. In this study, we examined ...the many factors shaping the reproductive output of three orchid taxa: Dactylorhiza majalis, D. incarnata var. incarnata, and D. fuchsii. We applied a statistical model to correlate female success (number of fruit sets) with individual characteristics (plant and inflorescence height, number of flowers, and spur length), number of pollinaria removed, flowering time, and density of floral units of co‐flowering rewarding plants. Our findings suggested that the broad spectrum of variations in Dactylorhiza's morphological traits, floral display, and flowering phenology within different environmental contexts has a significant impact on their reproductive success. The number of fruits increased with an increase in the number of pollinaria removed in the studied Dactylorhiza taxa. In contrast, a higher number of flowers per inflorescence and higher inflorescences in relation to individual height always decreased fruit set. We observed that low number of co‐flowering rewarding plants in populations could affect the Dactylorhiza reproductive output as magnets and competitor plants. The synchronization of flowering, or lack thereof, between Dactylorhiza and rewarding plants can limit reproductive success. This demonstrates that the food deception strategy is multidirectional, and reproductive output can vary considerably both spatially and temporally within the context of this strategy.
We observed that a wide range of variations in Dactylorhiza morphological traits, floral display, and flowering phenology in an environmental context affects Dactylorhiza's reproductive success. In contrast, a higher number of flowers per inflorescence and higher inflorescences in relation to individual height always decreased female success. The low number of co‐flowering rewarding plants in populations could shape the Dactylorhiza fruits set as magnets and competitor plants. The lack of synchronized flowering between Dactylorhiza and rewarding plants limits reproduction. This demonstrates that the food deception strategy is multidirectional, and reproductive output can vary considerably spatially and temporally within the context of this strategy.
Nectar, the most common floral reward, is generally used to determine whether an orchid species involves deceptive pollination. Estimates of the deceptive pollination systems with nectarless flowers ...have ranged from one quarter to one third of the nearly 30 000 species of orchids. These estimates, however, are biased towards temperate‐zone, usually terrestrial, orchids. Here we investigated nectar production and property in 34 epiphytic orchid species of the Southeast Asian genus Dendrobium. Twenty‐one species were observed producing nectar. The amount and sugar concentration (in bagged flowers) of 12 species varied from 0.45 to 2.78 μL and from 8.1% to 31.1%. The nectar was sucrose‐dominant, typical of bee‐pollinated flowers. Reconstruction of phylogenetic relationship indicated that transition of nectar secretion occurred in the genus. Spur length was positively correlated with flower size but species with relatively long spurs tended to produce small volume of nectar. Nectar production was strikingly variable among and within individuals in some species, suggesting that a vital measurement of bagged and fresh flowers is needed. Given that the quantitative measurement of nectar or floral reward in orchid species remains scarce, an estimate of deceptive pollination systems awaits further survey in diverse genera.
Although an estimate of the deceptive pollination systems with nectarless flowers has been usually cited as one‐third of the nearly 30 000 species in Orchidaceae, the quantitative measurements of nectar production in orchid flowers remain scarce. The genus Dendrobium is species‐rich, economic and horticultural importance, a group of epiphytic orchids in tropics characteristic of nectar spur. Previous studies in southeastern Asia showed these Dendrobium species generally involving deceptive pollination, with an assumption these species are nectarless. Here we investigated nectar production and property in 34 Dendrobium species over two years. Reconstruction of phylogenetic relationship indicated that transition of nectar secretion occurred in the genus and nectar production was positively correlated with flower size. Given that 21 species produced sucrose‐dominant nectar, typical of bee‐pollinated flowers, an estimate of deceptive pollination systems awaits further survey of nectar or floral reward in diverse genera.
The exact relationship between nicotine metabolism and dependence is not fully understood but is known to be influenced at a molecular level by genetic factors. A sample comprising 274 Chinese adult ...male smokers was categorized into groups based on their metabolic rates, namely fast, intermediate, and slow metabolizers. We then measured their smoking topography, evaluated their nicotine dependence, and assessed the rewarding effects. Based on these findings, we proposed the hypothesis that the rate of nicotine metabolism could influence the level of dopamine release which in turn had repercussions on the pleasurable and rewarding effects. To test this hypothesis, male mice were selected with different nicotine metabolic rates that closely resembled in the smoker group. We evaluated their nicotine dependence and rewarding effects through conditioned place preference and withdrawal symptom tests, supplemented with dopamine release measurements. In both animal and human, the slow metabolism group (SMG) required less nicotine to maintain a comparable level of dependence than the fast metabolism group (FMG). The SMG could achieve similar rewarding effects to FMG despite consuming less nicotine. Comparable dopamine levels released were therefore critical in setting the nicotine acquisition behavior in this animal model and also for the smokers tested. Our findings suggested that even within the same ethnicity of established smokers (Chinese Han), differences in nicotine metabolism were an important parameter to modulate the degree of nicotine dependence.
Since the ancient times, there exist all kinds of criminals in the world. In order to punish them, most authorities usually encourage the people to provide the evidence of a crime. To avoid the ...revenges from the criminals, it is necessary to study the anonymous reporting scheme with anonymous rewarding. In this paper, for the first time, we propose the novel concept of blockchain-based anonymous reporting scheme with anonymous rewarding (BB2AR). Our BB2AR scheme solves the open problem: how to realize the anonymous reporting and the anonymous rewarding simultaneously? First, we formalize the system model, definition, and security model of BB2AR. Second, we propose a concrete BB2AR scheme based on the elliptic curve public key cryptography. Our formal proof shows that our BB2AR scheme satisfies the anonymous reporting and the anonymous rewarding simultaneously. Finally, we analyze its efficiency and provide its prototype implementation. From the comparison, our BB2AR scheme is more efficient and practical.
This study investigates the road capacity allocation scheme and step tolling-rewarding scheme for carpooling. Different from most studies that assume a single or a continuous carpooling ratio, this ...study models multiple scenarios explicitly considering two-person, three-person, and four-person carpooling, as well as shared vans or shuttle buses. The proposed capacity allocation schemes reserve road service capacity during designated time windows for specific carpooling vehicles. During these time windows, the road service capacity is exclusively allocated to carpooling vehicles with a designated number of commuters (or carpoolers), while other vehicles are only allowed to pass the roadway bottleneck outside these time windows. Multiple reserved time windows can be designed and allocated to carpooling vehicles with different numbers of carpoolers. We examine the commuting equilibrium profile under given temporal capacity allocation schemes. We also model the potential “braking or tactical waiting” behavior due to temporal changes of right-of-way under the capacity allocation schemes. On the one hand, the temporal capacity allocation scheme encourages more carpoolers to share one vehicle and thus the number of vehicles on the road is potentially reduced; on the other hand, the temporal capacity allocation scheme yields inconvenience costs due to carpooling and road capacity waste due to braking or tactical waiting behavior under the capacity allocation scheme. We model this trade-off and quantify the system performance under the temporal road capacity allocation scheme. We also extend the analysis to the cases with heterogeneous inconvenience costs due to carpooling and with both temporal and spatial road capacity allocation (i.e., a proportion of road capacity is used for carpooling during certain time windows). Furthermore, we integrate the step tolling-rewarding scheme with the capacity allocation scheme, which further manages the carpooling choices and reduces total system cost. Numerical studies are presented to illustrate the analytical results. We found that carpooling should not be rewarded in some occasions, and instead should be penalized to avoid overcrowded carpooling flows in order to improve system efficiency.
•This paper investigates and optimizes the capacity allocation to carpooling vehicles.•This paper models the braking or tactical waiting due to temporal changes of right-of-way.•Carpooling might have to be encouraged to reduce road traffic.•Carpooling might have to be penalized to avoid overcrowded carpooling flows.
Although common among orchids, pollination by perfume‐gathering male euglossine bees is quite rare in other Neotropical families. In Gesneriaceae, for example, it is reported in two genera only, ...Drymonia and Gloxinia. Flowers of G. perennis are known to emit perfume, thereby attracting male euglossine bees as pollinators. However, detailed reports on the pollination ecology, as well as on chemistry of floral perfume of individuals in natural populations, are still missing. In this study, we report on the pollination ecology of G. perennis, focusing on the ecological significance of its floral perfume.
In natural populations in Peru, we documented the floral biology and breeding system of G. perennis, as well as its interaction with flower visitors. We also characterised the chemical composition of floral perfume, as well as its timing of emission.
Gloxinia perennis is self‐compatible and natural pollination success is high. Spontaneous self‐pollination occurs as a ‘just in case strategy’ when pollinators are scarce. Perfume‐collecting males of Eulaema cingulata and El. meriana were identified as pollinators. The perfume bouquet of G. perennis consists of 16 compounds. (E)‐Carvone epoxide (41%) and limonene (23%) are the major constituents. Perfume emission is higher at 09:00 h, matching the activity peak of Eulaema pollinators.
Flowers of G. perennis have evolved a mixed strategy to ensure pollination (i.e. self‐ and cross‐pollination), but cross‐pollination is favoured. The size and behaviour of Eulaema males enables only these bees to successfully cross‐pollinate G. perennis. Furthermore, G. perennis floral perfume traits (i.e. chemistry and timing of emission) have evolved to optimise the attraction of these bees.
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