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1.
This study sought to determine if providing affectively positive information about a flavor to preschool-aged children during tasting will increase recognition of and liking for the flavor and if the recognition and liking are associated. Forty-six 3- to 6-year-old children tasted 10 flavors: 5 presented with affectively positive information and 5 without. The 10 flavors were then presented again interspersed with 10 distracter flavors. Children reported whether they had tasted the flavor previously and provided hedonic ratings for each flavor. Children's ability to remember having tasted a flavor was greater when the flavor was presented with affectively positive information than without in children throughout the age range of 3-6 years. In children younger than 4.5 years, the provision of information had no effect on hedonic rating, whereas in older children, the provision of information was associated with greater hedonic ratings. We conclude that providing affectively positive information to children about a flavor can increase their ability to recognize the flavor as previously tasted and increases hedonic rating of the flavor in children older than 4.5 years.  相似文献   

2.
Incidental and intentional learning and memory for 2 novel flavors were compared in young and elderly subjects. Incidental and intentional learning groups rated 2 new soups on acceptability for different occasions and were tested for memory the next day. On the first day, only the intentional group was asked to memorize the stimuli. With incidental learning, elderly and young were equally good, but the young performed better with intentional than with incidental learning, whereas the elderly did not. There were no age-related differences in perceptual discrimination. When comparing perceived flavor with the memory of it, the elderly tend to overrate intensities of remembered flavor attributes, whereas the young tend to underrate them. Memory was not related to flavor pleasantness or neophobia. Like memory for taste and texture, flavor memory seems to be mainly tuned at detecting changes and based on "feelings of not knowing" rather than on precise identification and recognition of previously encountered stimuli.  相似文献   

3.
The rate at which triploid grass carp, Ctenopharyngodon idella , consumed two plant species from different locations was measured and compared to the chemical composition of the plants. Grass carp fed on Elodea canadensis from three lakes at significantly different rates ( P > 0.001), but did not eat Elodea densa from two of the sites at different rates. Feeding rate of the grass carp was positively correlated to the concentration of calcium ( r = 0.976) and lignin ( r = 0.946), but negatively correlated to the content of iron ( r =−0.808), silica (r=-0.934) and cellulose ( r =−0.922). Multiple regression analysis revealed that calcium and cellulose content were the most important predictors of consumption rate. These experiments demonstrate that water chemistry may affect palatability and could in part be responsible for some of the discrepancies in grass carp consumption rate and preference studies.  相似文献   

4.
Our reliance on our group members has exerted a profound influence over our motivation: successful group functioning requires that we are motivated to interact, and engage, with those around us. In other words, we need to belong. In this article, I explore the developmental origins of our need to belong. I discuss existing evidence that, from early in development, children seek to affiliate with others and to form long-lasting bonds with their group members. Furthermore, when children are deprived of a sense of belonging, it has negative consequences for their well-being. This focus on social motivation enables us to examine why and in what circumstances children engage in particular behaviours. It thus provides an important complement to research on social cognition. In doing so, it opens up important questions for future research and provides a much-needed bridge between developmental and social psychology.  相似文献   

5.
The kinetics of the acquisition and loss of the use of olfactory and visual cues were previously obtained in six experimental colonies of the ant Myrmica sabuleti meinert 1861, under normal conditions. In the present work, the same experiments were conducted on six other naive identical colonies of M. sabuleti, under electromagnetic radiation similar to those surrounding GSM and communication masts. In this situation, no association between food and either olfactory or visual cues occurred. After a recovery period, the ants were able to make such an association but never reached the expected score. Such ants having acquired a weaker olfactory or visual score and still undergoing olfactory or visual training were again submitted to electromagnetic waves. Not only did they lose all that they had memorized, but also they lost it in a few hours instead of in a few days (as under normal conditions when no longer trained). They kept no visual memory at all (instead of keeping 10% of it as they normally do). The impact of GSM 900 MHz radiation was greater on the visual memory than on the olfactory one. These communication waves may have such a disastrous impact on a wide range of insects using olfactory and/or visual memory, i.e., on bees.  相似文献   

6.
Learning ability and immunity to parasites are linked at the physiological level in several insect species. The aim of this work was to investigate the relationship between learning and immunity at an evolutionary level. We tested whether selection for improved learning ability in Drosophila melanogaster led to changes in parasitoid resistance as a correlated response. Similarly, we assayed whether selection for better parasitoid resistance led to a change in learning ability. There was no significant difference between selected and control lines in either case; the estimated confidence intervals for the differences indicate that a trade-off relationship is unlikely.  相似文献   

7.
A methodological issue in research relating daytime mood to dream content is the question of whether mood congruency effects—that is, recalling more negative events if the current mood is more negative—also play a role in the dream recall process. This study adopted an indirect approach by testing the hypothesis that interindividual differences in mood congruency effects in a memory task carried out in the daytime correlate with mood congruency effects in dream recall (recalling more negative dream emotions, as one would predict on the basis of the current stress level or overall mood state). The findings, however, did not support the hypothesis of mood congruency effects and, thus, rule out that the findings regarding the continuity hypothesis of dreaming are biased by selective recall. Studies with different methodological approaches are necessary to validate this study’s findings. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

8.
ABSTRACT: BACKGROUND: Greaves "delayed infection" hypothesis suggested that Acute Lymphoblastic Leukemia (ALL) in children is caused by a lack of exposure to infection in infancy, which may be due higher standards of sanitation. We have conducted an ecologic analysis of the relationship between sanitation, using Helicobacter pylori (H. pylori) as the marker, and the incidence of childhood ALL in 127 cancer registries from 28 countries. RESULTS: There were inverse associations between H. pylori perverse and ALL incidence rates in children. These associations were minor and only significant for ALL incidence rates for all cancer registries. They became non-significant and smaller in magnitude when the population source and/or the GNP per capita were added to the relationship. Furthermore, these results were unchanged when the associations were examined using the Generalized Estimating Equations. CONCLUSIONS: Although the findings showed lower prevalence of H. pylori and improved sanitation is associated with increased incidence of childhood ALL, they do not conclusively support Greaves "delayed infection" hypothesis.  相似文献   

9.
10.
近日节律是生物界普遍存在的一种生理现象,而内源性生物钟是产生近日节律的物质基础,它能使生物体感知并适应环境中的光、温度和食物等周期信号,从而使生物体与外界环境保持周期同步。研究表明,葡萄糖、胆固醇、腺苷、咖啡因、维生素A和视黄酸等营养物质能通过各自不同的方式调控哺乳动物的生物钟,影响其近日节律的信号输出。本文概述了至今为止研究发现的各类与生物钟信号调控相关的营养物质及功能的相关研究进展。  相似文献   

11.
Forty three subjects were invited under the pretence that they would take part in an experiment on hunger feelings. They came without having eaten anything that morning and received a standard breakfast containing orange juice, cream cheese on crackers and yoghurt. These products were later (when subjects returned after scoring hunger feelings during the day) used as targets amidst a set of distractors varied by adding or subtracting different amounts of two basic tastes. Orange juice was varied in sweetness and bitterness, cream cheese in sourness and bitterness and yoghurt in sweetness and sourness. The changes were made comparable by using just noticeable differences, determined in preliminary experiments with other subjects, as units of change. Two measurements of memory were compared, an absolute (indicating which were the targets) and a relative one (indicating whether the targets and distractors were more, less or equally pleasant, sweet, sour, bitter or salty as the item eaten at breakfast). Both methods showed incidental learning, but relative memory was superior. Memory differed between tastes and was partly product dependent. These experiments suggest that taste memory is tuned to detect novel and potentially dangerous stimuli rather than to remember features of earlier experienced stimuli with great precision.  相似文献   

12.

Background

Candidate gene case-control studies have identified several single nucleotide polymorphisms (SNPs) that are associated with asthma susceptibility. Most of these studies have been restricted to evaluations of specific SNPs within a single gene and within populations from European ancestry. Recently, there is increasing interest in understanding racial differences in genetic risk associated with childhood asthma. Our aim was to compare association patterns of asthma candidate genes between children of European and African ancestry.

Methodology/Principal Findings

Using a custom-designed Illumina SNP array, we genotyped 1,485 children within the Greater Cincinnati Pediatric Clinic Repository and Cincinnati Genomic Control Cohort for 259 SNPs in 28 genes and evaluated their associations with asthma. We identified 14 SNPs located in 6 genes that were significantly associated (p-values <0.05) with childhood asthma in African Americans. Among Caucasians, 13 SNPs in 5 genes were associated with childhood asthma. Two SNPs in IL4 were associated with asthma in both races (p-values <0.05). Gene-gene interaction studies identified race specific sets of genes that best discriminate between asthmatic children and non-allergic controls.

Conclusions/Significance

We identified IL4 as having a role in asthma susceptibility in both African American and Caucasian children. However, while IL4 SNPs were associated with asthma in asthmatic children with European and African ancestry, the relative contributions of the most replicated asthma-associated SNPs varied by ancestry. These data provides valuable insights into the pathways that may predispose to asthma in individuals with European vs. African ancestry.  相似文献   

13.
The association between arthritis and the weather   总被引:9,自引:0,他引:9  
 Despite the pervasiveness of the idea that arthritis is influenced by the weather, scientific evidence on the matter is sparse and non-conclusive. This study, conducted in the Australian inland city of Bendigo, sought to establish a possible relationship between the pain and rigidity of arthritis and the weather variables of temperature, relative humidity, barometric pressure, wind speed and precipitation. Pain and rigidity levels were scored by 25 participants with osteoarthritis and/or rheumatoid arthritis four times per day for 1 month from each season. Mean pain and rigidity scores for each time of each day were found to be correlated with the meteorological data. Correlations between mean symptoms and temperature and relative humidity were significant (P <0.001). Time of day was included in the analysis. Stepwise multiple regression analysis indicated that meteorological variables and time of day accounted for 38% of the variance in mean pain and 20% of the variance in mean rigidity when data of all months were considered. A post-study telephone questionnaire indicated 92% of participants perceived their symptoms to be influenced by the weather, while 48% claimed to be able to predict the weather according to their symptoms. Hence, the results suggest (1) decreased temperature is associated with both increased pain and increased rigidity and (2) increased relative himidity is associated with increased pain and rigidity in arthritis sufferers. Received: 3 October 1996/Accepted: 10 December 1996  相似文献   

14.
In non-territorial species, individuals can move freely and should be distributed in an ideal free manner between habitats and areas with respect to resources that influence lifetime reproductive success (LRS). Consequently, no relationship between diet quality and LRS should be expected. However, there have been no attempts to test this prediction. The present paper investigates the relationship between forage habitat use and LRS in red deer (Cervus elaphus) hinds within three neighbouring areas on the Isle of Rum which differed in their amounts of high-quality-forage habitat. Within areas, hinds move widely and have access to the same resources. We found no correlation between LRS of individual hinds and their use of high-quality-forage habitat (i.e. short Agrostis/Festuca grassland). Our analysis suggests that high hind densities on short Agrostis/Festuca grassland offset any advantages of increased access to preferred forage. These results support the hypothesis that red deer hinds are distributed in an ideal free manner with respect to the use of high-quality-forage habitat. However, hinds rarely leave areas where they are born, and the analysis suggests that constraints in changing areas hindered an ideal free distribution on a larger spatial scale. Consequently, mean LRS was not the same within the three investigated areas: one area, with a low amount of short Agrostis/Festuca grassland and a low hind density, contributed more male offspring (and more total offspring) per hind to the population than the other two areas. Received: 11 September 1998 / Accepted: 15 March 1999  相似文献   

15.
The possibility of feeding on green and newly fallen leaves of the small-leaved lime Tilia cordata was studied for the collembolans Protaphorura armata and Vertagopus pseudocinereus. Young leaves grown under sterile conditions and almost free of yeast fungi were found to be toxic to the collembolan V. pseudocinereus: feeding on them led to the death of the animals. Leaves grown under natural conditions were nontoxic: when used by the collembolans as feed, they provided for collembolan growth and fecundity. Feeding preferences of the collembolans in relation to the yeasts attributed to different ecomorphs—epiphytes, litter saprophytes, pedobionts, and saccharobionts—were studied. Of the 24 yeast strains isolated from plant green parts, litter, and soil and assigned to eight species, no strain was revealed that was not used by the collembolans. However, certain yeast strains were preferable for the collembolans. The population of the V. pseudocinereus collembolans feeding on the yeast Rhodotorula glutinis (nss 31–4) exceeded that grown on Cryptococcus terricola (2044) 1.5-fold. Thus, the collembolans have feeding preferences in relation to yeast fungi, as was shown earlier with mycelial micromycetes. The possible mechanisms of the feeding preferences of the collembolans in relation to yeasts are discussed.  相似文献   

16.
This preliminary study examined the association between sleep habits and problematic behaviors in healthy preschool children using an internationally standardized method. Two groups of 4-6-yr-old healthy Japanese children were recruited. Children in Group A (n=68) met one or more of the following three conditions: they went out from their home with adults after 21:00 h two or more times a week, they went to bed after 23:00 h four or more times a week, and they returned home after 21:00 h three or more times a week, while those in Group B (n=67) met none of these conditions. Sleep-wake logs and the Child Behavior Checklist (CBCL)/4-18 were completed daily for two weeks. The CBCL consists of questions with 113 items categorized into eight subscale items: (I) Withdrawn, (II) Somatic complaints, (III) Anxious/depressed, (IV) Social problems, (V) Thought problems, (VI) Attention problems, (VII) Delinquent behavior, and (VIII) Aggressive behavior. Internalizing (I+II+III), externalizing (VII+VIII), and total scale scores were also derived. Generally, the higher the score, the greater the likelihood of problematic behaviors in that scale. We compared both the CBCL scores and distribution of the CBCL score-determined clinical classification of behavior (normal, borderline, and abnormal) between the groups. Correlation coefficients between CBCL scores and each of the seven indices of the studied sleep habits (wake-up times, bedtimes, nocturnal sleep duration, nap duration, total sleep duration, and range of variation in wake-up and bedtime) were also assessed. Group A children showed significantly shorter average nocturnal sleep, nap, and total sleep duration, significantly later average bedtimes and wake-up times, and a significantly greater range of variation in bedtimes and wake-up times than Group B children. The CBCL score of the total scale was significantly higher in Group A than Group B children. The distribution of the clinical classifications of behavior between the two groups showed no significant differences. Although nocturnal sleep, nap, and total sleep duration did not correlate with total CBCL score, it showed a high positive correlation with wake-up times, bedtimes, and ranges of variation in both wake-up and bed times. The distribution of the clinical classification for the total scale showed significant differences between early and late risers, and also between regular and irregular sleepers. The number of children classified as normal for the total scale score was higher in early risers and regular sleepers than in late risers and irregular sleepers. Preschool children of Group A, late risers, late sleepers, irregular risers, and irregular sleepers were likely to show problematic behaviors.  相似文献   

17.
The fundamental determinants of division of labor among honey bee workers are age, genotype, and environment. These determinants work through intermediate physiological channels to realize particular patterns of division of labor. The change of juvenile hormone (JH) titer in worker bees is one such channel. Previous studies concentrated on the impact of JH on timing of in-hive and foraging activity. Here we examined the effects of JH on task specialization and the collection of pollen or nectar by same-age bees and we tested the possible impact on JH titer on foraging performance. Methoprene treatments were conducted after workers began to forage inside a flight room. We found that methoprene, a JH analogue, had no effect on preferences for pollen or nectar and, also, did not influence nectar foraging rate, nectar load size, and foraging span.  相似文献   

18.
Receptive language disorder in schizophrenia has been hypothesized to involve a fundamental deficit in the temporal (time-based) dynamics of brain function that includes disruptions to patterns of activation and synchronization. In this paper, candidate mechanisms and pathways that could account for this basic deficit are discussed. Parallels are identified between the patterns of language dysfunction observed for schizophrenia and dyslexia, two separate clinical disorders that may share a common abnormality in cell membrane phospholipids. A heuristic is proposed which details a trajectory involving an interaction of brain fatty acids and second-messenger function that modulates synaptic efficacy, and, in turn, influences language processing in schizophrenia patients. It is additionally hypothesized that a primary deficit of functional excitation originating in the cerebellum, in combination with a compensatory decrease of functional inhibition in the prefrontal cortex, influences receptive language dysfunction in schizophrenia.  相似文献   

19.
The relationship between the 50% survival time for flies feeding on a malathion-containing medium and the activity of acetylcholinesterase (AChE) was determined for 15 isofemale lines of Drosophila melanogaster. A significant correlation was found (r=0.28, P<0.05), with more resistant lines tending to have a lower level of AChE activity. An association between AChE and malathion resistance was also observed in a selection experiment. The AChE activity decreased in two of two populations selected for malathion resistance. AChE from these populations was altered in kinetic parameters (measured in crude head extracts) and electrophoretic mobility. Although the resistant AChE had a lower activity (V m) on either a per milligram protein or a per individual basis, its apparent K m for acetylthiocholine was lower than that of susceptible AChE. Recombination mapping of both low activity and fast electrophoretic mobility localized these traits to the region of the structural locus (Ace) on the third chromosome. The AChE activity of flies heterozygous for a variety of Ace lesions (kindly provided by Dr. W. M. Gelbart) was consistent with this location. The changes in AChE were suggested to have been caused by selection of alleles at the Ace locus.This work was supported by NSERC Grants A5857, G0183, and A0629.  相似文献   

20.
Observations in 5 fetal sheep at 120-134 days gestation, using either real time ultrasound or direct emg recordings to detect fetal movements, showed an association between such movements and cardiac accelerations (greater than 2 s duration and 4 beats/min amplitude). Neuromuscular blockade with gallamine abolished the fetal movements but not the accelerations.  相似文献   

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