Reinforcement-related neurons in the primate basal forebrain respond to the learned significance of task events rather than to the hedonic attributes of reward

The objective of this study was to determine if the responses of basal forebrain neurons are related to the cognitive processes necessary for the performance of behavioural tasks, or to the hedonic attributes of the reinforcers delivered to the monkey as

THE PHYLOGENETIC-RELATIONSHIPS AND CLASSIFICATION OF THE DOUCS AND SNUB-NOSED LANGURS OF CHINA AND VIETNAM

The taxonomy of the douc and snub-nosed langurs has changed several times during the 20th century. The controversy over the systematic position of these animals has been due in part to difficulties in studying them: both the doucs and the snub-nosed langurs are rare in the wild and are generally poorly represented in institutional collections. This review is based on a detailed examination of relatively large numbers of specimens of most of the species of langurs concerned. An attempt was made to draw upon as many types of information as were available in order to make an assessment of the phyletic relationships between the langur species under discussion. Toward this end, quantitative and qualitative features of the skeleton, specific features of visceral anatomy and characteristics of the pelage were utilized. The final data matrix comprised 178 characters. The matrix was analyzed using the program Hennig86. The results of the analysis support the following conclusions: (1) that the douc and snub-nosed langurs are generically distinct and should be referred to as species of Pygathrix and Rhinopithecus, respectively; (2) that the Tonkin snub-nosed langur be placed in its own subgenus as Rhinopithecus (Presbytiscus) avunculus and that the Chinese snub-nosed langur thus be placed in the subgenus Rhinopithecus (Rhinopithecus); (3) that four extant species of Rhinopithecus be recognized: R. (Rhinopithecus) roxellana Milne Edwards, 1870; R. (Rhinopithecus) bieti Milne Edwards, 1897; R. (Rhinopithecus) brelichi Thomas, 1903, and R. (Presbytiscus) avunculus Dollman, 1912; (4) that the Chinese snub-nosed langurs fall into northern and southern subgroups divided by the Yangtze river; (5) that R. lantianensis Hu and Qi, 1978, is a valid fossil species, and (6) the precise affinities and taxonomic status of the fossil species R. tingianus Matthew and Granger, 1923, are unclear because the type specimen is a subadult.

Fish-Specific Duplicated dmrt2b Contributes to a Divergent Function through Hedgehog Pathway and Maintains Left-Right Asymmetry Establishment Function

Gene duplication is thought to provide raw material for functional divergence and innovation. Fish-specific dmrt2b has been identified as a duplicated gene of the dmrt2a/terra in fish genomes, but its function has remained unclear. Here we reveal that Dmrt2b knockdown zebrafish embryos display a downward tail curvature and have U-shaped somites. Then, we demonstrate that Dmrt2b contributes to a divergent function in somitogenesis through Hedgehog pathway, because Dmrt2b knockdown reduces target gene expression of Hedgehog signaling, and also impairs slow muscle development and neural tube patterning through Hedgehog signaling. Moreover, the Dmrt2b morphants display defects in heart and visceral organ asymmetry, and, some lateral-plate mesoderm (LPM) markers expressed in left side are randomized. Together, these data indicate that fish-specific duplicated dmrt2b contributes to a divergent function in somitogenesis through Hedgehog pathway and maintains the common function for left-right asymmetry establishment.

Distribution and bioaccumulation of microcystins in water columns: A systematic investigation into the environmental fate and the risks associated with microcystins in Meiliang Bay, Lake Taihu

For the purpose of understanding the environmental fate of microcystins (MCs) and the potential health risks caused by toxic cyanobacterial blooms in Lake Taihu, a systematic investigation was carried out from February 2005 to January 2006. The distribution of MCs in the water column, and toxin bioaccumulations in aquatic organisms were surveyed. The results suggested that Lake Taihu is heavily polluted during summer months by toxic cyanobacterial blooms (with a maximum biovolume of 6.7 x 10(8) cells/L) and MCs. The maximum concentration of cell-bound toxins was 1.81 mg/g (DW) and the dissolved MCs reached a maximum level of 6.69 mu g/L. Dissolved MCs were always found in the entire water column at all sampling sites throughout the year. Our results emphasized the need for tracking MCs not only in the entire water column but also at the interface between water and sediment. Seasonal changes of MC concentrations in four species of hydrophytes (Eichhornic crassipes, Potamogeton maackianus, Alternanthera philoxeroides and Myriophyllum spicatum) ranged from 129 to 1317, 147 to 1534, 169 to 3945 and 124 to 956 ng/g (DW), respectively. Toxin accumulations in four aquatic species (Carassius auratus auratu, Macrobrachium nipponensis, Bellamya aeruginosa and Cristaria plicata) were also analyzed. Maximum toxin concentrations in the edible organs and non-edible visceral organs ranged from 378 to 730 and 754 to 3629 ng/g (DW), respectively. Based on field studies in Lake Taihu, risk assessments were carried out, taking into account the WHO guidelines and the tolerable daily intake (TDI) for MCs. Our findings suggest that the third largest lake in China poses serious health threats when serving as a source of drinking water and for recreational use. In addition, it is likely to be unsafe to consume aquatic species harvested in Lake Taihu due to the high-concentrations of accumulated MCs. (C) 2007 Elsevier Ltd. All rights reserved.

Seasonal dynamics of the hepatotoxic microcystins in various organs of four freshwater bivalves from the large eutrophic Lake Taihu of subtropical China and the risk to human consumption

So far, little is known on the distribution of hepatotoxic microcystin (MC) in various organs of bivalves, and there is no study on MC accumulation in bivalves from Chinese waters. Distribution pattern and seasonal dynamics of MC-LR, -YR and -RR in various organs (hepatopancreas, intestine, visceral mass, gill, foot, and rest) of four edible freshwater mussels (Anodonta woodiana, Hyriopsis cumingii, Cristaria plicata, and Lamprotula leai) were studied monthly during Oct. 2003-Sep. 2004 in Lake Taihu with toxic cyanobacterial blooms in the summer. Qualitative and quantitative determinations of MCs in the organs were done by LC-MS and HPLC. The major toxins were present in the hepatopancreas (45.5-55.4%), followed by visceral mass with substantial amount of gonad (27.6-35.5%), whereas gill and foot were the least (1.8-5.1%). The maximum MC contents in the hepatopancreas, intestine, visceral mass, gill, foot, and rest were 38.48, 20.65, 1.70, 0.64, 0.58, and 0.61 mu g/g DW, respectively. There were rather good positive correlation in MC contents between intestines and hepatopancreas of the four bivalves (r = 0.75-0.97, p < 0.05). There appeared to be positive correlations between the maximum MC content in the hepatopancreas and the delta(13)C (r = 0.919) or delta(15)N (r = 0.878) of the foot, indicating that the different MC content in the hepatopancreas might be due to different food ingestion. A glutathione (GSH) conjugate of MC-LR was also detected in the foot sample of C. plicata. Among the foot samples analyzed, 54% were above the provisional WHO tolerable daily intake (TDI) level, and the mean daily intakes from the four bivalves were 8-23.5 times the TDI value when the bivalves are eaten as a whole, suggesting the high risk of consuming bivalves in Lake Taihu. (C) 2005 Wiley Periodicals, Inc.

网上消费者购物动机、点击流行为及其之间的关系

Online shopping has been a growing phenomenon all over the world as well as China in the recent years. Studies on online shopping with clickstream data have become a new research stream. But it is a pity that the online conversion rate is low. Accordingly, we can study on online consumers focusing on their shopping motivation, and put their shopping motivation and clickstream behavior into an integrative frame, study on the both construction and their relationship, and then we can get insight in chinese online consumers. This study has two processes. First, this study will use the questionnaire to explore all kinds of consumers’ online shopping motivation, and then emend the questionnaire and form the ultimate one for the second process. Second, we will simulate a shopping site to get clickstream data, participants need to complete the ultimate questionnaire at the same time. We will analyse the integrated data from two measures, cluster analysis separately, and explore the correspondence between the two cluster methods. Results show that, first, Chinese online shoppers contain five steady motivation factors: usefulness, fashion involvement, ease of use on searching, ease of use on alternative evaluation, ease of use after trade. Fashion involvement is comparatively independent, while the other have correlations between each two. Second, Chinese consumers can be clustered into five steady clusters according to online shopping motivation: functional shoppers, following shoppers, surfing shoppers, conflicting shoppers, e-laggard. The five clusters have significant differences on job, monthly income and online shopping experience of late six months, while have no significant differences on gender, age and education. Third, Chinese consumers can be clustered into five steady clusters according to clickstream data: functional browsers, hedonic browsers, impulsive shoppers, comparative shoppers and knowledge building browsers. The five clusters have significant differences only on age, while have no significant differences on other demographic variables. Fourth, the cluster methods according to motivation and according to clickstream data are two comparatively independent cluster frame, but they have limit correspondence.

从赌博游戏中的损失厌恶行为看情感预测与体验在决策中的作用

In Kermer, Driver-Linn, Wilson and Gilbert’s (2006) study on affective forecast, they found that people have a tendency to overestimate affective reactions in gains and losses, and people expect losses to have greater hedonic impact than gains of equal magnitude. Because of thus affective forecasting error, people prefer to irrationally avoid losses. Loss aversion is then seen as both a wealth-maximizing error and an affect-maximizing error. The present study examined the relationships among affective forecast, affective experience and loss aversion, and tested Kermer et al.’s (2006) conclusion that people’s loss aversion is an affective forecasting error. In experiment 1, we examined the relationship between affective forecast and loss aversion. Kermer et al.’s (2006) hypothesized that when people expect losses to have greater hedonic impact than gains, they will accept the gambling task, and when people expect gains to have greater hedonic impact than losses, they will refuse the gambling task. We found that (1) individuals with lower loss aversion had a greater tendency to accept a gambling task than those with higher loss aversion; (2) individuals with lower loss aversion expected losses and gains to have smaller affective impacts than those with higher loss aversion. Thus, people never exactly calculated their forecasting affective. In experiment 2, we examined the relationship between affective forecast and affective experience. Consistent with Kermer et al.’s (2006) finding, we found that our participants tended to overestimate affective reactions in gains as well as losses. More interestingly, Kermer et al.’s (2006) found that participants’ predictions for a loss were significantly more distant from experienced emotions than were their predictions for a win, we, however, found the opposite —participants’ predictions for a win were significantly more distant from the experienced emotions than were their predictions for a loss. These experiments further validated the relations between affection and decision making, and contributed to our understanding on the affective reactions to future events. Our study imply that it was not the exact calculation of affective forecast on decision outcomes, but rather the magnitude of affection on outcomes, that influenced people’s affective decision making. It indicated that those with lower magnitude of affection would less like to avoid losses, and thus more like to accept a gambling task.