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Letteratura scientifica selezionata sul tema "Natural rewards"

Autore: Grafiati

Pubblicato: 7 settembre 2024

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Articoli di riviste sul tema "Natural rewards"

1

Jamali, Shole, Mohsen Parto Dezfouli, AmirAli Kalbasi, Mohammad Reza Daliri e Abbas Haghparast. "Selective Modulation of Hippocampal Theta Oscillations in Response to Morphine versus Natural Reward". Brain Sciences 13, n. 2 (14 febbraio 2023): 322. http://dx.doi.org/10.3390/brainsci13020322.

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Despite the overlapping neural circuits underlying natural and drug rewards, several studies have suggested different behavioral and neurochemical mechanisms in response to drug vs. natural rewards. The strong link between hippocampal theta oscillations (4–12 Hz) and reward-associated learning and memory has raised the hypothesis that this rhythm in hippocampal CA1 might be differently modulated by drug- and natural-conditioned place preference (CPP). Time–frequency analysis of recorded local field potentials (LFPs) from the CA1 of freely moving male rats previously exposed to a natural (in this case, food), drug (in this case, morphine), or saline (control) reward cue in the CPP paradigm showed that the hippocampal CA1 theta activity represents a different pattern for entrance to the rewarded compared to unrewarded compartment during the post-test session of morphine- and natural-CPP. Comparing LFP activity in the CA1 between the saline and morphine/natural groups showed that the maximum theta power occurred before entering the unrewarded compartment and after the entrance to the rewarded compartment in morphine and natural groups, respectively. In conclusion, our findings suggest that drug and natural rewards could differently affect the theta dynamic in the hippocampal CA1 region during reward-associated learning and contextual cueing in the CPP paradigm.

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2

Gomide, Paula Inez Cunha, e Cesar Ades. "Effects of Reward and Familiarity of Reward Agent on Spontaneous Play in Preschoolers: A Field Study". Psychological Reports 65, n. 2 (ottobre 1989): 427–34. http://dx.doi.org/10.2466/pr0.1989.65.2.427.

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A field experiment was conducted with preschool children to test the effect of rewards on a familiar, spontaneous play activity, in conditions as close as possible to the children's natural school context, and to examine the role of familiarity of the person who administered rewards. In three experimental conditions, children were rewarded either by their own teacher or by an unknown adult for playing with toys at the school playground and stayed with either the teacher or the unknown adult in the remaining part of reward sessions. Spontaneous play was significantly reduced by the reward relative to baseline levels and recovered after a 3-wk interval. However, no difference due to familiarity/unfamiliarity of reward agent could be found. Results, discussed in terms of an incentive contrast hypothesis, attest to the generality and external validity of the undermining effects of rewards.

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3

Nakamura, K., e T. Ono. "Lateral hypothalamus neuron involvement in integration of natural and artificial rewards and cue signals". Journal of Neurophysiology 55, n. 1 (1 gennaio 1986): 163–81. http://dx.doi.org/10.1152/jn.1986.55.1.163.

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Involvement of rat lateral hypothalamus (LHA) neurons in integration of motivation, reward, and learning processes was studied by recording single-neuron activity during cuetone discrimination, learning behavior to obtain glucose, or electrical rewarding intracranial self-stimulation (ICSS) of the posterior LHA. To relate the activity of an LHA neuron to glucose, ICSS, and anticipatory cues, the same licking task was used to obtain both rewards. Each neuron was tested with rewards alone and then with rewards signaled by cuetone stimuli (CTS), CTS1+ = 1,200 Hz for glucose, CTS2+ = 4,300 Hz for ICSS, and CTS- = 2,800 Hz for no reward. The activity of 318 neurons in the LHA was analyzed. Of these, 212 (66.7%) responded to one or both rewarding stimuli (glucose, 115; ICSS, 193). Usually, both rewards affected the same neuron in the same direction. Of 96 neurons that responded to both rewards, the responses of 72 (75%) were similar, i.e., either both excitatory or both inhibitory. When a tone was associated with glucose or ICSS reward, 81 of the 212 neurons that responded to either or both rewards and none of 106 neurons that failed to respond to either reward acquired a response to the respective CTS. Usually, the response to a tone was in the same direction as the reward response. Of 45 neurons that responded to both glucose and CTS1+, 38 (84.4%) were similar, and of 66 that responded to both ICSS and CTS2+, 47 (71.2%) were similar. The neural response to a tone was acquired rapidly after licking behavior was learned and was extinguished equally rapidly before licking stopped in extinction. The latency of the neural response to CTS1+ was 10-150 ms (58.7 +/- 40.9 ms, mean +/- SE, n = 31), and that of the first lick was 100-370 ms (204.8 +/- 59.1 ms, n = 31). The latency of neural responses to CTS2+ was 10-230 ms (68.3 +/- 53.5 ms, n = 33), and that of the first lick was 90-370 ms (212.4 +/- 58.5 ms, n = 33). There was no significant difference between the neural response latencies for the two cue tones nor between the lick latencies for the different rewards. Neurons inhibited by glucose or ICSS reward were distributed widely in the LHA, whereas most excited neurons were in the posterodorsal subarea; fewer were in the anteroventral subarea. Neurons responding to the CTS for glucose or ICSS were found more frequently in the posterior region.(ABSTRACT TRUNCATED AT 400 WORDS)

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4

Bastian, Abda Billah Faza Muhammadkan, Wildan Alim Nurhidayah e Yogi Damai Syaputra. "Memberikan Reward sebagai Upaya Meningkatkan Motivasi Belajar Anak". Jurnal al-Shifa Bimbingan Konseling Islam 3, n. 1 (30 giugno 2022): 40–58. http://dx.doi.org/10.32678/alshifa.v3i1.7875.

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This study aims to find out how to increase children's learning motivation after being given areward. Rewards given to children are in the form of object rewards, praise rewards, symbolic rewards (star stamps) and touch rewards. The research method uses descriptive qualitative methods with data collection techniques through observation, interviews and documentation. Data analysis techniques use the Miles and Huberman model. The results of the studys how that giving rewards helps increase student learning motivation. Most students like reward items suchas snacks, because they are useful for them. Symbolic rewards such as star stamps also greatly enhance student learning. This is natural because the child willfeel proud of the symbol and show off this achievement to his friends and parents. Reward praise and touch can also improve some students. However, some students think that praise or touch is normal, so it doesn't increase their motivation to learn

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5

Lardeux, Sylvie, Dany Paleressompoulle, Remy Pernaud, Martine Cador e Christelle Baunez. "Different populations of subthalamic neurons encode cocaine vs. sucrose reward and predict future error". Journal of Neurophysiology 110, n. 7 (1 ottobre 2013): 1497–510. http://dx.doi.org/10.1152/jn.00160.2013.

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The search for treatment of cocaine addiction raises the challenge to find a way to diminish motivation for the drug without decreasing it for natural rewards. Subthalamic nucleus (STN) inactivation decreases motivation for cocaine while increasing motivation for food, suggesting that STN can dissociate different rewards. Here, we investigated how rat STN neurons respond to cues predicting cocaine or sucrose and to reward delivery while rats are performing a discriminative stimuli task. We show that different neuronal populations of STN neurons encode cocaine and sucrose. In addition, we show that STN activity at the cue onset predicts future error. When changing the reward predicted unexpectedly, STN neurons show capacities of adaptation, suggesting a role in reward-prediction error. Furthermore, some STN neurons show a response to executive error (i.e., “oops neurons”) that is specific to the missed reward. These results position the STN as a nexus where natural rewards and drugs of abuse are coded differentially and can influence the performance. Therefore, STN can be viewed as a structure where action could be taken for the treatment of cocaine addiction.

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Feng, Yufei, Xiaoyu Yang, Xiaodan Zhu e Michael Greenspan. "Neuro-symbolic Natural Logic with Introspective Revision for Natural Language Inference". Transactions of the Association for Computational Linguistics 10 (2022): 240–56. http://dx.doi.org/10.1162/tacl_a_00458.

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Abstract We introduce a neuro-symbolic natural logic framework based on reinforcement learning with introspective revision. The model samples and rewards specific reasoning paths through policy gradient, in which the introspective revision algorithm modifies intermediate symbolic reasoning steps to discover reward-earning operations as well as leverages external knowledge to alleviate spurious reasoning and training inefficiency. The framework is supported by properly designed local relation models to avoid input entangling, which helps ensure the interpretability of the proof paths. The proposed model has built-in interpretability and shows superior capability in monotonicity inference, systematic generalization, and interpretability, compared with previous models on the existing datasets.

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Pastor-Bernier, Alexandre, Arkadiusz Stasiak e Wolfram Schultz. "Reward-specific satiety affects subjective value signals in orbitofrontal cortex during multicomponent economic choice". Proceedings of the National Academy of Sciences 118, n. 30 (20 luglio 2021): e2022650118. http://dx.doi.org/10.1073/pnas.2022650118.

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Sensitivity to satiety constitutes a basic requirement for neuronal coding of subjective reward value. Satiety from natural ongoing consumption affects reward functions in learning and approach behavior. More specifically, satiety reduces the subjective economic value of individual rewards during choice between options that typically contain multiple reward components. The unconfounded assessment of economic reward value requires tests at choice indifference between two options, which is difficult to achieve with sated rewards. By conceptualizing choices between options with multiple reward components (“bundles”), Revealed Preference Theory may offer a solution. Despite satiety, choices against an unaltered reference bundle may remain indifferent when the reduced value of a sated bundle reward is compensated by larger amounts of an unsated reward of the same bundle, and then the value loss of the sated reward is indicated by the amount of the added unsated reward. Here, we show psychophysically titrated choice indifference in monkeys between bundles of differently sated rewards. Neuronal chosen value signals in the orbitofrontal cortex (OFC) followed closely the subjective value change within recording periods of individual neurons. A neuronal classifier distinguishing the bundles and predicting choice substantiated the subjective value change. The choice between conventional single rewards confirmed the neuronal changes seen with two-reward bundles. Thus, reward-specific satiety reduces subjective reward value signals in OFC. With satiety being an important factor of subjective reward value, these results extend the notion of subjective economic reward value coding in OFC neurons.

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He, Liuyi, Jifeng Luo, Yisong Tang, Zhiyan Wu e Han Zhang. "Motivating User-Generated Content: The Unintended Consequences of Incentive Thresholds". MIS Quarterly 47, n. 3 (1 giugno 2022): 1015–44. http://dx.doi.org/10.25300/misq/2022/17369.

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While monetary rewards have been widely used by online platforms to motivate user-generated content (UGC) contributions, users may not always demonstrate the expected behaviors. Unintended consequences of reward policies, exemplified by unchanged or reduced UGC contributions, may occur. Through two natural experiments, this study investigates the implications of providing users with an incentive structure that rewards users’ continued contribution according to the volume of UGC. Using a unique data set on two completion-contingent incentive programs from a popular online aesthetic medicine platform, we examine user responses to reward thresholds. We found that after users reach a threshold to obtain a monetary reward, they are less likely to continue contributing UGC, suggesting a minimal-effort effect. Our findings indicate that social approval from peers helps to mitigate unintended user responses to monetary reward policies. We also observed that monetary rewards primarily improve the quality and website traffic of low- to moderate-quality contributions.

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Dooren, Marierose M. M. van, Valentijn T. Visch e Renske Spijkerman. "The Design and Application of Game Rewards in Youth Addiction Care". Information 10, n. 4 (6 aprile 2019): 126. http://dx.doi.org/10.3390/info10040126.

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Different types of rewards are applied in persuasive games to encourage play persistence of its users and facilitate the achievement of desired real-world goals, such as behavioral change. Persuasive games have successfully been applied in mental healthcare and may hold potential for different types of patients. However, we question to what extent game-based rewards are suitable in a persuasive game design for a substance dependence therapy context, as people with substance-related disorders show decreased sensitivity to natural rewards, which may result in different responses to commonly applied game rewards compared to people without substance use disorders. In a within-subject experiment with 20 substance dependent and 25 non-dependent participants, we examined whether play persistence and reward evaluation differed between the two groups. Results showed that in contrast to our expectations, substance dependent participants were more motivated by the types of rewards compared to non-substance dependent participants. Participants evaluated monetary rewards more positively than playing for virtual points or social rewards. We conclude this paper with design implications of game-based rewards in persuasive games for mental healthcare.

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Ryvkin, Julia, Liora Omesi, Yong-Kyu Kim, Mali Levi, Hadar Pozeilov, Lital Barak-Buchris, Bella Agranovich et al. "Failure to mate enhances investment in behaviors that may promote mating reward and impairs the ability to cope with stressors via a subpopulation of Neuropeptide F receptor neurons". PLOS Genetics 20, n. 1 (18 gennaio 2024): e1011054. http://dx.doi.org/10.1371/journal.pgen.1011054.

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Living in dynamic environments such as the social domain, where interaction with others determines the reproductive success of individuals, requires the ability to recognize opportunities to obtain natural rewards and cope with challenges that are associated with achieving them. As such, actions that promote survival and reproduction are reinforced by the brain reward system, whereas coping with the challenges associated with obtaining these rewards is mediated by stress-response pathways, the activation of which can impair health and shorten lifespan. While much research has been devoted to understanding mechanisms underlying the way by which natural rewards are processed by the reward system, less attention has been given to the consequences of failure to obtain a desirable reward. As a model system to study the impact of failure to obtain a natural reward, we used the well-established courtship suppression paradigm in Drosophila melanogaster as means to induce repeated failures to obtain sexual reward in male flies. We discovered that beyond the known reduction in courtship actions caused by interaction with non-receptive females, repeated failures to mate induce a stress response characterized by persistent motivation to obtain the sexual reward, reduced male-male social interaction, and enhanced aggression. This frustrative-like state caused by the conflict between high motivation to obtain sexual reward and the inability to fulfill their mating drive impairs the capacity of rejected males to tolerate stressors such as starvation and oxidative stress. We further show that sensitivity to starvation and enhanced social arousal is mediated by the disinhibition of a small population of neurons that express receptors for the fly homologue of neuropeptide Y. Our findings demonstrate for the first time the existence of social stress in flies and offers a framework to study mechanisms underlying the crosstalk between reward, stress, and reproduction in a simple nervous system that is highly amenable to genetic manipulation.

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Più fonti

Tesi sul tema "Natural rewards"

1

Becker, Christoph Alexander [Verfasser]. "Neuronal processing of natural rewards / Christoph Alexander Becker". Konstanz : Bibliothek der Universität Konstanz, 2017. http://d-nb.info/1132995639/34.

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2

Cantor, Anna. "Amphetamine sensitization disrupts certain aspects of associative learning about natural rewards". Thesis, University of British Columbia, 2010. http://hdl.handle.net/2429/27911.

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Repeated exposure to psychostimulant drugs induces numerous behavioral, and neuronal changes, which in animals is thought to model certain neural adaptations that may contribute to drug addiction. Chronic AMPH has repeatedly been shown to alter the acquisition and expression of associations between a conditioned stimulus (CS) and natural rewards. Although repeated psychostimulant exposure can interfere with associative learning about natural food rewards, the manner in which these treatments affect acquisition and expression of these associations remains unclear. The current study investigated how repeated AMPH exposure (5 x 2 mg/kg over 10 days) affects learning, extinction and cue-induced reinstatement of instrumental responding of food-seeking behavior. Rats were trained over 7 days to press one of two levers for food and a tone/light CS. During subsequent extinction conducted over 3-6 days, responding delivered neither food nor the CS. On reinstatement tests, active lever presses produced the CS, but not food. Rats received repeated AMPH or saline prior to training (exp. 1A), after instrumental training (exp. 1B), or after training and extinction (exp. 1C). In experiment 1A, cue-induced reinstatement was blunted significantly in AMPH-treated rats. In contrast, AMPH-treatment after initial training (experiment 1B) significantly retarded extinction relative to controls, but did not affect cue-induced reinstatement. In experiment 1C, AMPH exposed rats displayed enhanced cue-induced reinstatement. Experiment 2 was conducted to clarify the results of experiment 1A. Rats were trained to nosepoke for food following a CS, and were then tested in the presence of two novel levers, responding on one delivered the food-associated CS. AMPH treatment impaired the acquisition of a new response with conditioned reinforcement. These findings suggest that repeated AMPH exposure prior to formation of response-CS associations selectively disrupts the ability of food-related stimuli to influence instrumental responding. Exposure after initial associative learning impedes extinction. AMPH administration after training and extinction enhance responding. Collectively, these findings suggest that AMPH sensitization can perturb certain aspects of amygdala-mediated associative learning related to natural, food rewards, and this impairment seems to reflect a weakened CS-reward association as opposed to a reduced preference for the food.

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3

Lund, Lisa, e Patrick O'Regan. "Gamifying Natural Language Acquisition : A quantitative study on Swedish antonyms while examining the effects of consensus driven rewards". Thesis, KTH, Skolan för datavetenskap och kommunikation (CSC), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-187485.

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Little research has been done on antonymic relations, a great deal of this has been done by linguists Paradis et al. Gamification was used in natural language acquisition by Bos and Nissim in their 2015 study about noun-noun compound relations, but gamification of information retrieval remains a relatively new field of study. This thesis reproduced work done by Paradis et al. in an attempt to answer the following questions for Swedish antonyms: will reversing word order in antonymic relations affect the strength of said word pair? Will the perceived strength of canonical antonyms have a lower variance than that of non-canonical antonyms? It will also examine whether giving points depending on the agreement with other users reduce the occurrence of extreme points on an ordinal scale? Two parallel studies were conducted, one using a web app which implemented consensus driven rewards, and another utilising a questionnaire. Reversing the order of the words did not to alter the perceived strength of the antonymic pair, which is consistent with the results acquired by Paradis et al. in 2009. Results regarding variance of canonical and non-canonical antonym pairs were inconclusive. An implementation with consensus driven rewards yielded more extreme values than the questionnaire. More research is suggested to improve the strength of the results.
Lite forskning har gjorts om antonymer inom natural language acquisition, och mycket av den forskning som finns om antonymer är gjord av Paradis et al. inom lingvistik. Gamifiering har använts inom natural language acquisition, bland annat av Bos och Nissim i deras studie om relationer hos sammansatta substantiv från 2015. Denna rapport försöker besvara följande frågor om svenska antonymer: spelar ordningen på ord i ett antonympar någon roll i hur parets antonymiska styrka uppfattas? Kommer den uppfattade styrkan hos kanoniska antonympar ha lägre varians än deras ickekanoniska motsvarigheter? Rapporten undersöker även huruvida konsensusdriven poängsättning påverkar förekomsten av extremvärden på en ordinalskala. Två parallella delstudier utfördes, en webapp som implementerade konsensusdriven poängsättning, samt ett frågeformulär utan poängsättning. Ordningen av orden i ett antonympar hade ingen signifikant påverkan på dess uppfattade styrka, i enighet med Paradis et al.s studie från 2009. Resultaten angående kanoniska antonymers varians var inte entydiga. Implementationen med konsensusbaserad poängsättning gav fler extremvärden än frågeformuläret. Eftersom detta var en liten studie behövs vidare undersökning för att stärka resultaten.

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4

Doremus-Fitzwater, Tamara L. "Incentive motivational processes in adolescent and adult rats effects of amphetamine sensitization on cue-induced craving for natural rewards /". Diss., Online access via UMI:, 2008.

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5

McGraw, Justin James. "Reward processing alterations for natural reward in alcohol-preferring (P) rats: Incentive contrast, reward discrimination, and alcohol consumption". Bowling Green State University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1526310548842931.

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6

Smith, Aaron Paul. "NEUROBEHAVIORAL MEASUREMENTS OF NATURAL AND OPIOID REWARD VALUE". UKnowledge, 2019. https://uknowledge.uky.edu/psychology_etds/164.

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In the last decade, (non)prescription opioid abuse, opioid use disorder (OUD) diagnoses, and opioid-related overdoses have risen and represent a significant public health concern. One method of understanding OUD is as a disorder of choice that requires choosing opioid rewards at the expense of other nondrug rewards. The characterization of OUD as a disorder of choice is important as it implicates decision- making processes as therapeutic targets, such as the valuation of opioid rewards. However, reward-value measurement and interpretation are traditionally different in substance abuse research compared to related fields such as economics, animal behavior, and neuroeconomics and may be less effective for understanding how opioid rewards are valued. The present research therefore used choice procedures in line with behavioral/neuroeconomic studies to determine if drug-associated decision making could be predicted from economic choice theories. In Experiment 1, rats completed an isomorphic food-food probabilistic choice task with dynamic, unpredictable changes in reward probability that required constant updating of reward values. After initial training, the reward magnitude of one choice subsequently increased from one to two to three pellets. Additionally, rats were split between the Signaled and Unsignaled groups to understand how cues modulate reward value. After each choice, the Unsignaled group received distinct choice-dependent cues that were uninformative of the choice outcome. The Signaled group also received uninformative cues on one option, but the alternative choice produced reward-predictive cues that informed the trial outcome as a win or loss. Choice data were analyzed at a molar level using matching equations and molecular level using reinforcement learning (RL) models to determine how probability, reward magnitude, and reward-associated cues affected choice. Experiment 2 used an allomorphic drug versus food procedure where the food reward for one option was replaced by a self-administered remifentanil (REMI) infusion at doses of 1, 3 and 10 μg/kg. Finally, Experiment 3 assessed the potential for both REMI and food reward value to be commonly scaled within the brain by examining changes in nucleus accumbens (NAc) Oxygen (O2) dynamics. Results showed that increasing reward probability, magnitude, and the presence of reward-associated cues all independently increased the propensity of choosing the associated choice alternative, including REMI drug choices. Additionally, both molar matching and molecular RL models successfully parameterized rats’ decision dynamics. O2 dynamics were generally commensurate with the idea of a common value signal for REMI and food with changes in O2 signaling scaling with the reward magnitude of REMI rewards. Finally, RL model-derived reward prediction errors significantly correlated with peak O2 activity for reward delivery, suggesting a possible neurological mechanism of value updating. Results are discussed in terms of their implications for current conceptualizations of substance use disorders including a potential need to change the discourse surrounding how substance use disorders are modeled experimentally. Overall, the present research provides evidence that a choice model of substance use disorders may be a viable alternative to the disease model and could facilitate future treatment options centered around economic principles.

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7

DE, CHIARA VALENTINA. "The role of endocannabinoid system in stress e natural reward". Doctoral thesis, Università degli Studi di Roma "Tor Vergata", 2010. http://hdl.handle.net/2108/1177.

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Gli endocannabinoidi giocano un ruolo fondamentale nella regolazione della trasmissione sinaptica. L’esposizione ad eventi stressanti o gratificanti induce modificazioni sinaptiche nelle diverse aree cerebrali. L’attività del sistema degli endocannabinoidi nei circuiti neuronali coinvolti nelle risposte allo stress e alla gratificazione (reward) suggerisce il suo coinvolgimento nelle risposte comportamentali e negli adattamenti a livello sinaptico tipiche dello stress, delle droghe d’abuso ed altre forme di comportamenti reward dipendenti. In questo studio, mediante l’utilizzo di registrazioni elettrofisiologiche abbiamo dimostrato che lo stress indotto in topi cronicamente esposti ad aggressione (social defeat stress) e reward naturali come arricchimento ambientale e consumo di una soluzione contenente saccarosio (3%), alterano in modo opposto il controllo delle trasmissione sinaptica mediato dai recettori dei cannabinoidi CB1 nello striato. Lo striato svolge un ruolo centrale nelle funzioni motorie comportamentali ed emotive modulate dallo stress e da eventi gratificanti; in questa struttura i recettori CB1 sono espressi a livelli elevati modulando la trasmissione sinaptica sia inibitoria che eccitatoria. Nel corso di questo lavoro, abbiamo dimostrato che l’ inibizione presinaptica delle correnti GABAergiche inibitorie indotta dall’agonista dei recettori CB1 HU210, è abolita in topi esposti a stress cronico, mentre risulta significativamente potenziata a seguito di trattamenti gratificanti quali arricchimento ambientale e consumo di saccarosio. La sensibilità dei recettori CB1 espressi sui terminali glutammatergici risulta invece inalterata, così come quella dei recettori GABAB espressi presinapticamente sulle sinapsi GABAergiche, suggerendo che le alterazioni registrate in cellule di animali esposti ai protocolli di stress e reward, siano limitate ai recettori presinaptici CB1 GABAergici. Le alterazioni delle risposte CB1 mediate sono lentamente reversibili e sono riscontrabili anche a seguito della stimolazione dei recettori metabotropici del glutammato 5, responsabili della mobilizzazione dei cannabinoidi endogeni. Abbiamo inoltre osservato che l’aumento dell’ inibizione presinaptica delle correnti GABAergiche inibitorie CB1-mediata a seguito di trattamenti gratificanti quali arricchimento ambientale e consumo di saccarosio, svolge un ruolo cruciale di protezione dalle conseguenze sinaptiche e comportamentali indotte da stress. Infine, abbiamo esteso i nostri studi all’interazione tra i recettori CB1 e il BDNF, molecola coinvolta nelle conseguenze comportamentali delle esperienze di stress e di gratificazione. Il BDNF inibisce l’attività dei CB1 nello striato, attraverso un meccanismo tirosina chinasi dipendente e questa inibizione è riscontrabile anche a seguito della sensitizzazione reward-mediata di questi recettori. La regolazione BDNF mediata dei recettori CB1 potrebbe avere un ruolo rilevante nelle funzioni cognitive e comportamentali, mentre un’azione diretta sui recettori CB1 e sul metabolismo degli endocannabinoidi potrebbe essere valutato nel trattamento di disturbi neuropsichiatrici associati allo stress.
The endocannabinoid system plays a fundamental role in the regulation of synaptic transmission. Exposure to stressful or rewarding events triggers synaptic adaptations in many brain areas. The activity of the endocannabinoid system in stress-responsive neural circuits and central reward pathway suggests that it may be involved in the behavioural responses and synaptic effects typical of stress, drug addiction an other forms of reward-based behaviors. In the present study, by means of electrophysiological recordings we found that social defeat stress, induced in mice by exposure to aggression, and natural rewards such as running wheel and sucrose consumption, alter in opposite way the cannabinoid CB1 receptor-mediated control of synaptic transmission in the striatum. The striatum plays a central role in motor, cognitive and emotional functions modulated by stress and rewarding agents, and contains high levels of cannabinoid receptors controlling both excitatory and inhibitory synaptic transmission . We found that the presynaptic inhibition of GABAergic inhibitory postsynaptic currents induced by the cannabinoid CB1 receptor agonist HU210 was abolished after chronic stress exposure, whereas it was remarkably potentiated after running wheel and sucrose consumption. In contrast, the sensitivity of glutamate synapses to CB1 receptor stimulation was unaltered, as well as that of GABA synapses to the stimulation of other presynaptic receptors such as GABAB. The alterations of cannabinoid CB1 receptor-mediated responses were slowly reversible and were also detectable following the mobilization of endocannabinoids by metabotropic glutamate receptor 5 stimulation. Finally, we found that the up-regulation of cannabinoid transmission induced by wheel running or sucrose played a crucial role in the protective effects of these environmental manipulations against the motor and synaptic consequences of stress. Since BDNF also play a role in the emotional consequences of stress and of rewarding experiences, we have extended our study to address the functional interplay between BDNF and cannabinoid CB1 receptors in the striatum. We found that BDNF potently inhibits CB1 receptor function in the striatum. The action of BDNF on CB1 receptor function was tyrosine kinase dependent, and was complete even after receptor sensitization with behavioral manipulations activating the reward system. BDNF-mediated regulation of striatal CB1 receptors might have relevant roles in cognitive and behavioral functions and targeting cannabinoid CB1 receptors or endocannabinoid metabolism might be a valuable option to treat stress-associated neuropsychiatric conditions.

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8

Werme, Martin. "On natural and drug-induced reward : genetic, biochemical and behavioral comparisons /". Stockholm : [Karolinska Univ. Press], 2001. http://diss.kib.ki.se/2001/91-7349-027-X/.

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Vicq, Eléonore. "Modulation nicotinique de l'activité dopaminergique et des comportements motivés". Electronic Thesis or Diss., Sorbonne université, 2024. http://www.theses.fr/2024SORUS135.

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Le tabagisme, qui concerne un milliard de personnes à travers le monde, est à l’origine de plus de 8 millions de décès évitables par an, et constitue ainsi un enjeu sanitaire majeur. La nicotine, principal composé actif du tabac, agit au niveau du système nerveux en se liant aux récepteurs nicotiniques de l’acétylcholine (nAChR). Cette liaison produit de manière concomitante des effets récompensants et aversifs, permettant respectivement de promouvoir et limiter la consommation de tabac. Les nAChR sont exprimés au niveau du système de la récompense, notamment l’aire tegmentale ventrale (VTA), mais également dans de nombreuses autres régions cérébrales perturbées par la nicotine. L’objectif de mes travaux de thèse a été d’étudier l’effet de la nicotine sur deux voies cérébrales centrées sur la VTA et non canoniques : la voie reliant noyau interpédonculaire (IPN) et la VTA d’une part, et la voie projetant de la VTA vers le claustrum (CLA) d’autre part. J’ai dans un premier temps étudié l’implication de l’IPN dans le renforcement à la nicotine. Nous avons montré que les neurones de l’IPN répondent de manière hétérogène à la nicotine, et découvert qu’ils sont sensibles à de faibles doses de nicotine qui n’activent pas la VTA. A l’aide de nouveaux outils chémogénétiques que j’ai développés, nous avons mis en évidence que les nAChR contenant β4 de l’IPN jouent un rôle de frein sur la réponse à la nicotine dans la VTA, et diminuent ainsi l’effet récompensant de la drogue. L’IPN ne jouerait donc pas uniquement un rôle dans l’aversion mais également dans le renforcement à la nicotine. Dans un second temps, j’ai étudié comment une exposition prolongée à la nicotine modifie les interactions sociales, et comment la voie VTA-CLA pourrait participer à ces perturbations comportementales. Nous avons observé qu’une exposition chronique à la nicotine produit une augmentation de la saillance d’un stimulus social nouveau dans une tâche trois-chambres, se traduisant par une augmentation du temps passé avec le nouveau congénère. De plus, l’activation optogénétique de la voie VTA-CLA induit une perte de la préférence pour le stimulus social nouveau dans la tâche trois-chambre, tandis que la stimulation optogénétique non contingente reproduit les effets comportementaux d’une exposition prolongée à la nicotine. La voie VTA-CLA semble donc impliquée dans la saillance pour de nouveaux stimuli sociaux, et cette fonction serait perturbée par la nicotine chronique. L’ensemble de ces travaux permet de mettre en évidence l’importance de ces deux nouvelles voies non canoniques dans l’addiction à la nicotine
Smoking affects one billion people worldwide, and is responsible for over 8 million preventable deaths a year, making it a major health concern. Nicotine, the main active compound in tobacco, acts on the nervous system by binding to nicotinic acetylcholine receptors (nAChRs). There is a wide diversity of nAChR subunits (��2 to 10 and β2 to 4) which assemble in different combinations to form pentameric receptors with different biophysical properties and localizations. Nicotine concomitantly produces rewarding and aversive effects, promoting and limiting nicotine consumption, respectively. While nAChRs are expressed in the reward system, notably the ventral tegmental area (VTA), they are also present in many other brain regions susceptible to nicotine-induced disruptions. The aim of my thesis work was to investigate the involvement of two non-canonical VTA-connected brain pathways in nicotine addiction: the pathways linking the interpeduncular nucleus (IPN) and the VTA, and the one connecting the VTA to the claustrum (CLA). I first studied the involvement of the IPN in nicotine reinforcement. We showed that IPN neurons respond heterogeneously to nicotine, and discovered that they are sensitive to low doses of nicotine that do not activate the VTA. Using new chemogenetic tools that I have developed, we have shown that β4-containing nAChRs of the IPN act as a brake on the response to nicotine in the VTA, thereby reducing the rewarding effects of the drug. The IPN would therefore contribute not only to aversion but also to nicotine reinforcement. Secondly, I studied how prolonged exposure to nicotine alters social interactions, and the potential involvement of the VTA-CLA pathway in these behavioral perturbations. We showed that chronic nicotine exposure increased the saliency of a novel social stimulus in a three-chamber task, resulting in an increased interaction time with novel conspecifics. Moreover, optogenetic activation of the VTA-CLA pathway induced a loss of preference for the novel social stimulus, while non-contingent optogenetic stimulation replicated the behavioral effects of prolonged nicotine exposure. Therefore, the VTA-CLA pathway seems to be involved in the saliency for new social stimuli, and this function may be disrupted by chronic nicotine exposure. Taken together, these studies highlight the importance of these two non-canonical pathways in nicotine addiction

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Davis, Jon Franklin. "A Functional, Anatomical, and Molecular Investigation of Natural Reward: Sexual Plasticity and Limbic System". Cincinnati, Ohio : University of Cincinnati, 2005. http://www.ohiolink.edu/etd/view.cgi?acc%5Fnum=ucin1123831570.

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Thesis (Ph. D.)--University of Cincinnati, 2005.
Title from electronic thesis title page (viewed Mar. 23, 2006). Includes abstract. Keywords: limbic, reward, plasticity. Includes bibliographical references.

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Libri sul tema "Natural rewards"

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United States. Bureau of Land Management. Office of Public Affairs, a cura di. Public rewards from public lands: 2000. Washington, D.C: U.S. Department of the Interior, Bureau of Land Management, Office of Public Affairs, 2000.

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United States. Bureau of Land Management. Public rewards from public lands. [Washington, D.C.]: U.S. Dept. of the Interior, Bureau of Land Management, 1995.

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United States. Bureau of Land Management, a cura di. Public rewards from public lands. [Washington, D.C.]: U.S. Dept. of the Interior, the Bureau of Land Management, 1997.

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Bartsch, Ulrich. Financial risks and rewards in LNG projects: Qatar, Oman, and Yemen. 2^a ed. [Oxford]: Oxford Institute for Energy Studies, 1998.

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United States. Bureau of Land Management. Office of Public Affairs e National Science and Technology Center. Branch of Publishing Services, a cura di. Public rewards from public lands 2003: Montana. Washington, D.C: Bureau of Land Management, Office of Public Affairs, 2003.

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United States. Bureau of Land Management. Office of Public Affairs e National Science and Technology Center. Branch of Publishing Services, a cura di. Public rewards from public lands 1999: Montana. Washington, D.C: Bureau of Land Management, Office of Public Affairs, 1999.

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United States. Bureau of Land Management. Office of Public Affairs e National Science and Technology Center. Branch of Publishing Services, a cura di. Public rewards from public lands 2000: Montana. Washington, D.C: Bureau of Land Management, Office of Public Affairs, 2000.

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United States. Bureau of Land Management. Office of Public Affairs e National Science and Technology Center. Branch of Publishing Services, a cura di. Public rewards from public lands 1997: Montana. Washington, D.C: Bureau of Land Management, Office of Public Affairs, 1997.

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United States. Bureau of Land Management. Public rewards from public lands: 2007-2008. Washington, D.C: U.S. Department of the Interior, Bureau of Land Management, Office of Public Affairs, 2008.

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United States. Bureau of Land Management. Office of Public Affairs, a cura di. Public rewards from public lands: 1999. Washington, D.C: U.S. Department of the Interior, Bureau of Land Management, [Office of Public Affairs], 1999.

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Capitoli di libri sul tema "Natural rewards"

1

Molua, Ernest L. "Global Warming and Carbon Sequestration in Africa’s Forests: Potential Rewards for New Policy Directions in the Congo Basin". In New Frontiers in Natural Resources Management in Africa, 59–77. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-11857-0_5.

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Cui, Shiliang, Zhongbin Wang e Luyi Yang. "Distance-Based Service Priority". In Innovative Priority Mechanisms in Service Operations, 99–118. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-30841-3_6.

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AbstractObtaining a service usually comes with both rewards and costs. For example, dining at a popular restaurant provides customers with a pleasant dining experience, but also incurs costs to them. The costs include the direct service charge that customers have to pay to receive the service (the meal cost) and indirect hassle costs such as going to the restaurant and waiting in line for the service. When the service reward is too low or the service fee is too high, customers will be less likely interested in the service. The same happens when the hassle cost of seeking service is too high, which is especially true when customers must travel a long distance to obtain a service that tends to have cumbersome wait times. It is without question that increasing the number of customers being served (i.e. system throughput) is critical for service providers, as it translates directly into service revenue in the case of a for-profit company and service provision in the case of a non-profit organization. Therefore, how may service providers incentivize customers located far away from the service location to seek service? In this chapter, we introduce an innovative but natural distance-based service priority mechanism to help service providers increase their system throughput. The idea is to assign higher service priority to customers who have to travel farther for the service, thus giving them with new incentives to consider using the service. We shall demonstrate, among other results, that such a mechanism can significantly increase system throughput by attracting more customers to use the service, and the increase can be up to 50% compared to the ordinary first-come-first-served service discipline. This chapter is primarily based on Wang et al. (Manuf Serv Oper Manag, 25(1), 353–369, 2023) where interested readers can find proofs of the findings shown in this chapter.

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van Daalen, Silke, e Hal Caswell. "15. Demographic Sources of Variation in Fitness". In Human Evolutionary Demography, 345–60. Cambridge, UK: Open Book Publishers, 2024. http://dx.doi.org/10.11647/obp.0251.15.

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Heritable variation in fitness is required for natural selection, which makes identification of the sources of variation in fitness a crucial question in evolutionary biology. A neglected source of variance is the demography of the population. Demographic processes can generate a large amount of variance in fitness, but these processes are stochastic and the variance results from the random outcomes of survival, development, and reproduction, and will therefore be non-heritable. To quantify the variance in fitness due to individual stochasticity, the mean and variance of lifetime reproductive output (LRO) are calculated from age-specific fertility and mortality rates. These rates are incorporated into a stochastic model (a Markov chain with rewards) and the statistical properties of lifetime reproduction, including Crow’s Index of the opportunity for selection, are calculated. We present the basic theory for these calculations, and compare results with empirical measurements of the opportunity for selection. In the case of a historical population in Finland, 57% of the empirically observed opportunity for selection can be explained by individual stochasticity resulting from demographic processes. Analyzing the contribution of demography to variance in fitness will improve our understanding of the selective pressures operating on human populations.

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Liu, Shilei, Xiaofeng Zhao, Bochao Li e Feiliang Ren. "Knowledge-Grounded Dialogue with Reward-Driven Knowledge Selection". In Natural Language Processing and Chinese Computing, 455–66. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-88480-2_36.

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Morbini, Fabrizio, David DeVault, Kenji Sagae, Jillian Gerten, Angela Nazarian e David Traum. "FLoReS: A Forward Looking, Reward Seeking, Dialogue Manager". In Natural Interaction with Robots, Knowbots and Smartphones, 313–25. New York, NY: Springer New York, 2013. http://dx.doi.org/10.1007/978-1-4614-8280-2_28.

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Hu, Xiaoxuan, Hengtong Zhang, Wayne Xin Zhao, Yaliang Li, Jing Gao e Ji-Rong Wen. "RAST: A Reward Augmented Model for Fine-Grained Sentiment Transfer". In Natural Language Processing and Chinese Computing, 196–209. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-88480-2_16.

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Wang, Sheng, Xiaoying Chen e Shengwu Xiong. "Attention Based Reinforcement Learning with Reward Shaping for Knowledge Graph Reasoning". In Natural Language Processing and Chinese Computing, 275–87. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-88480-2_22.

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Teichmann, Fabian, e Marie-Christin Falker. "Compliance Incentives, Whistleblowing, and the Payment of Rewards for Information". In Artificial Intelligence: Anthropogenic Nature vs. Social Origin, 490–99. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-39319-9_56.

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Hill, Berkeley. "Factors of production and their rewards: theory of distribution." In An introduction to economics: concepts for students of agriculture and the rural sector, 115–37. 5^a ed. Wallingford: CABI, 2021. http://dx.doi.org/10.1079/9781800620063.0006.

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Abstract Following an introduction into the nature of production, this chapter explains four broad groups of factors of production in agriculture: (i) land; (ii) capital; (iii) labour; and (iv) entrepreneurship. Also discussed are the mobility and unemployment of the factors of production, as well as the allocation of the factors of production and their rewards.

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du Preez-Wilkinson, Nathaniel, e Marcus Gallagher. "Fitness Landscape Features and Reward Shaping in Reinforcement Learning Policy Spaces". In Parallel Problem Solving from Nature – PPSN XVI, 500–514. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-58115-2_35.

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Atti di convegni sul tema "Natural rewards"

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Goyal, Prasoon, Scott Niekum e Raymond J. Mooney. "Using Natural Language for Reward Shaping in Reinforcement Learning". In Twenty-Eighth International Joint Conference on Artificial Intelligence {IJCAI-19}. California: International Joint Conferences on Artificial Intelligence Organization, 2019. http://dx.doi.org/10.24963/ijcai.2019/331.

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Recent reinforcement learning (RL) approaches have shown strong performance in complex domains, such as Atari games, but are highly sample inefficient. A common approach to reduce interaction time with the environment is to use reward shaping, which involves carefully designing reward functions that provide the agent intermediate rewards for progress towards the goal. Designing such rewards remains a challenge, though. In this work, we use natural language instructions to perform reward shaping. We propose a framework that maps free-form natural language instructions to intermediate rewards, that can seamlessly be integrated into any standard reinforcement learning algorithm. We experiment with Montezuma's Revenge from the Atari video games domain, a popular benchmark in RL. Our experiments on a diverse set of 15 tasks demonstrate that for the same number of interactions with the environment, using language-based rewards can successfully complete the task 60% more often, averaged across all tasks, compared to learning without language.

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Pasunuru, Ramakanth, e Mohit Bansal. "Reinforced Video Captioning with Entailment Rewards". In Proceedings of the 2017 Conference on Empirical Methods in Natural Language Processing. Stroudsburg, PA, USA: Association for Computational Linguistics, 2017. http://dx.doi.org/10.18653/v1/d17-1103.

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Chawla, Kushal, Balaji Vasan Srinivasan e Niyati Chhaya. "Generating Formality-Tuned Summaries Using Input-Dependent Rewards". In Proceedings of the 23rd Conference on Computational Natural Language Learning (CoNLL). Stroudsburg, PA, USA: Association for Computational Linguistics, 2019. http://dx.doi.org/10.18653/v1/k19-1078.

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Pasunuru, Ramakanth, Han Guo e Mohit Bansal. "DORB: Dynamically Optimizing Multiple Rewards with Bandits". In Proceedings of the 2020 Conference on Empirical Methods in Natural Language Processing (EMNLP). Stroudsburg, PA, USA: Association for Computational Linguistics, 2020. http://dx.doi.org/10.18653/v1/2020.emnlp-main.625.

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Lee, Youngwon, Jinu Lee e Seung-won Hwang. "Learning to Rank Generation with Pairwise Partial Rewards". In Proceedings of the 2023 Conference on Empirical Methods in Natural Language Processing. Stroudsburg, PA, USA: Association for Computational Linguistics, 2023. http://dx.doi.org/10.18653/v1/2023.emnlp-main.371.

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Romano, Giulia, Andrea Agostini, Francesco Trovò, Nicola Gatti e Marcello Restelli. "Multi-Armed Bandit Problem with Temporally-Partitioned Rewards: When Partial Feedback Counts". In Thirty-First International Joint Conference on Artificial Intelligence {IJCAI-22}. California: International Joint Conferences on Artificial Intelligence Organization, 2022. http://dx.doi.org/10.24963/ijcai.2022/472.

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There is a rising interest in industrial online applications where data becomes available sequentially. Inspired by the recommendation of playlists to users where their preferences can be collected during the listening of the entire playlist, we study a novel bandit setting, namely Multi-Armed Bandit with Temporally-Partitioned Rewards (TP-MAB), in which the stochastic reward associated with the pull of an arm is partitioned over a finite number of consecutive rounds following the pull. This setting, unexplored so far to the best of our knowledge, is a natural extension of delayed-feedback bandits to the case in which rewards may be dilated over a finite-time span after the pull instead of being fully disclosed in a single, potentially delayed round. We provide two algorithms to address TP-MAB problems, namely, TP-UCB-FR and TP-UCB-EW, which exploit the partial information disclosed by the reward collected over time. We show that our algorithms provide better asymptotical regret upper bounds than delayed-feedback bandit algorithms when a property characterizing a broad set of reward structures of practical interest, namely α-smoothness, holds. We also empirically evaluate their performance across a wide range of settings, both synthetically generated and from a real-world media recommendation problem.

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Böhm, Florian, Yang Gao, Christian M. Meyer, Ori Shapira, Ido Dagan e Iryna Gurevych. "Better Rewards Yield Better Summaries: Learning to Summarise Without References". In Proceedings of the 2019 Conference on Empirical Methods in Natural Language Processing and the 9th International Joint Conference on Natural Language Processing (EMNLP-IJCNLP). Stroudsburg, PA, USA: Association for Computational Linguistics, 2019. http://dx.doi.org/10.18653/v1/d19-1307.

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Li, Siyao, Deren Lei, Pengda Qin e William Yang Wang. "Deep Reinforcement Learning with Distributional Semantic Rewards for Abstractive Summarization". In Proceedings of the 2019 Conference on Empirical Methods in Natural Language Processing and the 9th International Joint Conference on Natural Language Processing (EMNLP-IJCNLP). Stroudsburg, PA, USA: Association for Computational Linguistics, 2019. http://dx.doi.org/10.18653/v1/d19-1623.

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Cao, Meng, Mukul Sharma, Maria-Magdalena Chiotoroiu e Torsten Clemens. "Geothermal Energy Recovery for Urban Heating Applications: Risks and Rewards". In SPE Europe Energy Conference and Exhibition. SPE, 2024. http://dx.doi.org/10.2118/220012-ms.

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Abstract It is possible to recover large quantities of heat from modestly hot reservoirs (90 °C). The harvested energy can be used to heat homes and businesses in the winter months. To accomplish this, water is circulated through the hot formation using injection and production wells. The water flows through the rock matrix and any natural or induced fractures. This paper discusses a field study to determine the feasibility of recovering heat from the subsurface by water injection into a high permeability sandstone reservoir. The heat recovery rate is computed and the risks associated with large scale water injection are evaluated. It is shown that it is difficult to avoid the formation of fractures in the injection well. The increase in pore pressure can also result in the slippage of natural faults. No previous study has systematically investigated the influence of both heat conduction and convection and the associated stress alteration and fracture height growth during long-term water injection. In this paper a general poro-thermo-elastic model is used to model the process of long-term water injection for geothermal heat recovery. The model is based on mass and energy balances for fluid flow, for the reservoir temperature, and a stress balance for the reservoir stress/deformation calculation. As the reservoir stress condition evolves over time, we apply a fracture propagation criterion to predict fracture initiation and growth. A Newton-Raphson formulation and fully implicit algorithms are used to ensure tight coupling between multiple physical components in simulations and are optimized to predict water injection-induced fracturing. A modified Mohr-Coulomb failure criterion is used to detect the possibility of inducing natural fault slippage during geothermal energy recovery. The results demonstrate that it is possible to induce fracture propagation and natural fault slippage during long-term water injection for geothermal energy recovery. A comprehensive sensitivity study is conducted to investigate the effect of solids content, injection rate, stress contrast, containment, and injection temperature. The results indicate that (1) reducing the injection rate is a possible way to delay fracture initiation; (2) the fractures can potentially breach the shale above the injection zone. However, vertical migration of the fractures will be limited to a few meters; (3) improving the water quality delays the onset of fracturing but fractures still propagate after a few months of injection; and (4) increasing the injection water temperature also reduces the fracture length, but it is not possible to completely avoid injection induced fractures. Furthermore, the possibility of slip of natural faults is evaluated. Stresses and pore pressures computed at the location of the fault indicate that vertical faults are unlikely to slip; and (2) a fault is likely to slip if it has a dip angle of over 20 degrees. The fully 3-D poro-thermo-elastic flow and fracture propagation model presented in this paper provides a valuable tool to evaluate the rewards and risks associated with geothermal energy extraction. No such study has been undertaken in the past to our knowledge. Methods to reduce the risks of fracturing and fault activation are suggested based on the results.

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Imaizumi, Masaaki, e Ryohei Fujimaki. "Factorized Asymptotic Bayesian Policy Search for POMDPs". In Twenty-Sixth International Joint Conference on Artificial Intelligence. California: International Joint Conferences on Artificial Intelligence Organization, 2017. http://dx.doi.org/10.24963/ijcai.2017/607.

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This paper proposes a novel direct policy search (DPS) method with model selection for partially observed Markov decision processes (POMDPs). DPSs have been standard for learning POMDPs due to their computational efficiency and natural ability to maximize total rewards. An important open challenge for the best use of DPS methods is model selection, i.e., determination of the proper dimensionality of hidden states and complexity of policy functions, to mitigate overfitting in highly-flexible model representations of POMDPs. This paper bridges Bayesian inference and reward maximization and derives marginalized weighted log-likelihood~(MWL) for POMDPs which takes both advantages of Bayesian model selection and DPS. Then we propose factorized asymptotic Bayesian policy search (FABPS) to explore the model and the policy which maximizes MWL by expanding recently-developed factorized asymptotic Bayesian inference. Experimental results show that FABPS outperforms state-of-the-art model selection methods for POMDPs, with respect both to model selection and to expected total rewards.

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Rapporti di organizzazioni sul tema "Natural rewards"

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Carrillo, Paul E., Edgar Castro e Carlos Scartascini. Do Rewards Work?: Evidence from the Randomization of Public Works. Inter-American Development Bank, aprile 2017. http://dx.doi.org/10.18235/0011793.

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This paper evaluates the effect of positive inducements on tax behavior by exploiting a natural experiment in which a municipality of Argentina randomly selected 400 individuals among more than 72,000 taxpayers who had complied with payment of their property tax. These individuals were publicly recognized and awarded the construction of a sidewalk. Results indicate that: i) being selected in the lottery and publicly recognized by the government has a positive but not persistent effect on future compliance; ii) receiving the sidewalk has a large positive and persistent effect; iii) high and persistent spillover effects exist: some neighbors of those who receive the reward comply more too, and these effects can be even larger than the direct effects; and iv) there is no financial motive effect; i.e., people do not pay their taxes just to participate in the lottery. Recognition serves only as a short-term incentive, but the provision of a durable and visible good has more persistent and broader effects. These findings provide evidence on features that make a positive inducement more successful, whether for tax compliance or other policy purposes.

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Southgate, Douglas. Alternatives for Habitat Protection and Rural Income Generation. Inter-American Development Bank, marzo 1997. http://dx.doi.org/10.18235/0008857.

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The key question the research in this paper tries to answer is whether those four activities truly represent a viable economic alternative in Latin America's environmentally fragile hinterlands. Several cases in each line of activity are analyzed to determine the level and distribution of the net financial returns they generate. Special attention was devoted to examining the degree to which net returns flow to local populations, as opposed to other economic agents. In general, examination of the rewards local populations can expect to derive from ecotourism and the harvesting of nontimber forest products suggests that allocating time and effort to those activities is unlikely to be very remunerative since unskilled labor is not particularly scarce in rural areas. In addition, little is to be gained by controlling access to natural resources, which for the most part are abundant. Moreover, making the sector-specific human capital and other investments needed for forest dwellers to capture more of the net returns from ecotourism, genetic prospecting, and so forth would probably not benefit them very much. Instead, furnishing them with education and training

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Timar, Levente. Modelling private land-use decisions affecting forest cover: the effect of land tenure and environmental policy. Motu Economic and Public Policy Research, novembre 2022. http://dx.doi.org/10.29310/wp.2022.12.

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I use geographic data and discrete choice modelling to investigate private land-use decisions in the context of prominent New Zealand land institutions and environmental policies. Land-use conversions involving gains and losses in planted forests and natural forests are modelled individually. Land under Māori freehold tenure is found to be less likely to be used for pastoral grazing and also less likely to undergo land-use conversion (both to and from a forested use). With respect to environmental policies, results suggest the incentives of the Emissions Trading Scheme did not significantly affect land-use decisions during the sample period of 2008-2016: the carbon reward had little effect on afforestation, and the deforestation liability was largely ineffective at deterring deforestation. On the other hand, the East Coast Forestry Project is found to have increased planted forest area in the district both by encouraging afforestation beyond baseline levels and by discouraging deforestation. Evidence for its effect on regenerating natural forest area is weaker in the data.

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Kotula, Hannah. Valuing forest ecosystem services in New Zealand. Motu Economic and Public Policy Research, novembre 2022. http://dx.doi.org/10.29310/wp.2022.11.

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Society depends on services and benefits provided by ecosystems. Yet, many of our actions affect ecosystems in ways that undermine long-term human wellbeing. Although ecosystems provide many services to society, many of these services are not accounted for in land-use decisions. The concept of “ecosystem services” offers a framework for understanding our dependence on nature and can encourage decision makers to consider broader impacts of land-use decisions beyond short-term economic rewards. Furthermore, economic valuation of ecosystem services offers a potential strategy for including the value of ecosystem services in decision making. Here I describe several ecosystem service frameworks and outline how these frameworks can inform land-use decisions, with a particular focus on those involving forests. I then describe methods for valuing ecosystem services. Following this, I provide examples relating to forest ecosystem services and draw conclusions based on existing valuation studies in New Zealand. My intention is to convey how an ecosystem service approach could be used in New Zealand to capture benefits provided by ecosystems that are often not accounted for in land-use decisions.

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Greenhill, Lucy, Christopher Leakey e Daniela Diz. Second Workshop report: Mobilising the science community in progessing towards a sustainable and inclusive ocean economy. Scottish Universities Insight Institute, luglio 2021. http://dx.doi.org/10.15664/10023.23693.

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Across the Blue Economy, science must play a fundamental role in moving us away from business as usual to a more sustainable pathway. It provides evidence to inform policy by understanding baselines, trends and tipping points, as well as the multiple and interacting effects of human activities and policy interventions. Measuring progress depends on strong evidence and requires the design of a monitoring framework based on well-defined objectives and indicators, informed by the diverse disciplines required to inform progress on cross-cutting policy objectives such as the Just Transition. The differences between the scientific and policy processes are stark and affect interaction between them, including, among other factors, the time pressures of governmental decision-making, and the lack of support and reward in academia for policy engagement. To enable improved integration, the diverse nature of the science / policy interface is important to recognise – improved communication between scientists and policy professionals within government is important, as well as interaction with the wider academic community through secondments and other mechanisms. Skills in working across boundaries are valuable, requiring training and professional recognition. We also discussed the science needs across the themes of the Just Transition, Sustainable Seafood, Nature-based Solutions and the Circular Economy, where we considered: • What research and knowledge can help us manage synergies and trade-offs? • Where is innovation needed to promote synergies? • What type of indicators, data and evidence are needed to measure progress? The insights developed through dialogue among participants on these themes are outlined in Section 4 of this report.

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De Wit, Paul. Securing Land Tenure for Prosperity of the Planet and its Peoples. Rights and Resources Initiative, febbraio 2023. http://dx.doi.org/10.53892/ogcw7082.

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Indigenous Peoples, Afro-descendant Peoples, and local communities produce up to 70 percent of the world’s food with lower climate change and environmental impact than agribusinesses, but many remain under the poverty threshold. They are the de facto owners and managers of massive carbon stocks in forested and non–forested ecosystems, but markets fail to fairly reward this. This is all achieved with these communities having legal rights over only 20 percent of their land and receiving only 1.7 percent of global climate finance for self–determined investment and nature conservation. Clarifying their rights and establishing solid tenure security and capital to invest in exercising those rights are a must. The need for Indigenous Peoples, Afro-descendant Peoples, and local communities to acquire secure tenure over land and resources to achieve conservation and production goals is twofold. First, these groups need to establish a tenure safety network over their claimed lands and resources to prevent unintended consequences, like spillovers and leakages from other global responses to climate change, environmental rehabilitation, and food systems transformation. Second, they want secure tenure as part of a more enabling environment to fully unlock the potential of delivering their own solutions to current systems, threats, and opportunities.

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Hefetz, Abraham, e Justin O. Schmidt. Use of Bee-Borne Attractants for Pollination of Nonrewarding Flowers: Model System of Male-Sterile Tomato Flowers. United States Department of Agriculture, ottobre 2003. http://dx.doi.org/10.32747/2003.7586462.bard.

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The use of bee natural product for enhancing pollination is especially valuable in problematic crops that are generally avoided by bees. In the present research we attempted to enhance bee visitation to Male Sterile (M-S) tomato flowers generally used in the production of hybrid seeds. These flowers that lack both pollen and nectar are unattractive to bees that learn rapidly to avoid them. The specific objects were to elucidate the chemical composition of the exocrine products of two bumble bee species the North American Bombus impatiens and the Israeli B. terrestris. Of these, to isolate and identify a bee attractant which when sprayed on M-S tomato flowers will enhance bee visitation, and to provide a procedure of the pheromone application regime. During the research we realized that our knowledge of B. impatiens is too little and we narrowed the objective to learning the basic social behavior of the bees and the pattern of foraging in a flight chamber and how it is affected by biogenic amines. Colonies of B. impatiens are characterized by a high number of workers and a relatively small number of queens. Size differences between queens and workers are pronounced and the queen seems to have full control over egg laying. Only about 9% of the workers in mature colonies had mature oocytes, and there were no signs of a "competition phase" as we know in B. terrestris. Queens and workers differ in their exocrine bouquet. Queen's Dufour's gland possesses a series of linear, saturated and unsaturated hydrocarbons whereas that of workers contains in addition a series of wax-type esters. Bees were trained to either visit or avoid artificially scented electronic flowers in a flight chamber. Since bee also learned to avoid scented non-rewarding flowers we attempted to interfere with this learning. We tested the effect of octopamine, a biogenic amine affecting bee behavior, on the choice behavior of free-flying bumblebees. Our results show that octopamine had no significant effect on the bees' equilibrium choice or on the overall rate of the behavioral change in response to the change in reward. Rather, octopamine significantly affected the time interval between the change in reward status and the initiation of behavioral change in the bee. In B. terrestris we studied the foraging pattern of the bees on tomato flowers in a semi commercial greenhouse in Yad Mordechai. Bee learned very quickly to avoid the non- rewarding M-S flowers, irrespective of their arrangement in the plot, i.e., their mixing with normal, pollen bearing flowers. However, bees seem to "forget" this information during the night since the foraging pattern repeats itself the next morning. Several exocrine products were tested as visitation enhancers. Among these, tarsal gland extracts are the most attractive. The compounds identified in the tarsal gland extract are mostly linear saturated hydrocarbons with small amounts of unsaturated ones. Application was performed every second day on leaves in selected inflorescences. Bee visitation increased significantly in the treated inflorescences as compared to the control, solvent treated. Treatment of the anthers cone was more effective than on the flower petals or the surrounding leaves. Methanol proved to be a non-flower-destructive solvent. We have shown that bumble bees (B. terrestris) can be manipulated by bee-borne attractants to visit non-rewarding flowers. We have further demonstrated that the bees learning ability can be manipulated by applying exogenously octopamine. Both methods can be additively applied in enhancing pollination of desired crops. Such manipulation will be especially useful in tomato cultivation for hybrid seed production.

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