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1.
The aim of the present research was to investigate the influence of packaging design on consumers' perception of quality of fresh carrots. We adopted a conjoint analytic approach in which 251 Danish consumers rated the perceived quality and value (expected price) of nine packaging images, obtained by systematically varying packaging type (plastic bag, plastic box, cardboard paper) and label color (blue, brown, grey). The results revealed that the main attribute influencing the perceptions of the consumer was packaging type. Specifically, the box packages (both plastic and cardboard) were associated to carrots of significantly higher perceived value and quality compared to the plastic bag packages. Furthermore, the study identified the most important aspects consumers attend to when purchasing carrots. A transparent packaging, allowing consumers to inspect the produce, was mentioned as the most important aspect. Being organic and local were identified as the second and third most important, respectively.

Practical applications

Packaging is an important extrinsic product attribute that can influence consumer perceptions of fresh produce. The results have implications for retailers and producers with respect to the choice of packaging and label design. Specifically, consumers associated box packages to higher quality produce, suggesting that carrots in this type of package may command higher price and/or be preferred to bagged alternatives at a similar price point. The study further indicated the importance of using a transparent packaging that clearly allow consumers to inspect the produce, and also suggest that “organic” and “local” are important drivers of purchase for this product category.  相似文献   

2.
The effect of some fresh‐cut carrot label attributes on consumer purchase intention was evaluated using conjoint analysis. The following three attributes were chosen and manipulated: price (high and low), packaging type (polyethylene bags and expanded polystyrene trays) and production process (organic with certification stamp, organic without certification stamp and no information). A complete factorial design was used, and 12 hypothetical packages of fresh‐cut carrot were developed and evaluated by 96 consumers based on their purchase intention. The consumers were divided into four groups with different opinions. Low price and organic with certification label were the favorite choices of the groups. Only one group preferred expanded polystyrene trays. No interactions were exhibited among the attributes in all groups.  相似文献   

3.
Humans and animals readily generalize previously learned knowledge to new situations. Determining similarity is critical for assigning category membership to a novel stimulus. We tested the hypothesis that category membership is initially encoded by the similarity of the activity pattern evoked by a novel stimulus to the patterns from known categories. We provide behavioral and neurophysiological evidence that activity patterns in primary auditory cortex contain sufficient information to explain behavioral categorization of novel speech sounds by rats. Our results suggest that category membership might be encoded by the similarity of the activity pattern evoked by a novel speech sound to the patterns evoked by known sounds. Categorization based on featureless pattern matching may represent a general neural mechanism for ensuring accurate generalization across sensory and cognitive systems.  相似文献   

4.
Fuzzy cluster analysis has been applied to the 20 amino acids by using 65 physicochemical properties as a basis for classification. The clustering products, the fuzzy sets (i.e., classical sets with associated membership functions), have provided a new measure of amino acid similarities for use in protein folding studies. This work demonstrates that fuzzy sets of simple molecular attributes, when assigned to amino acid residues in a protein''s sequence, can predict the secondary structure of the sequence with reasonable accuracy. An approach is presented for discriminating standard folding states, using near-optimum information splitting in half-overlapping segments of the sequence of assigned membership functions. The method is applied to a nonredundant set of 252 proteins and yields approximately 73% matching for correctly predicted and correctly rejected residues with approximately 60% overall success rate for the correctly recognized ones in three folding states: alpha-helix, beta-strand, and coil. The most useful attributes for discriminating these states appear to be related to size, polarity, and thermodynamic factors. Van der Waals volume, apparent average thickness of surrounding molecular free volume, and a measure of dimensionless surface electron density can explain approximately 95% of prediction results. hydrogen bonding and hydrophobicity induces do not yet enable clear clustering and prediction.  相似文献   

5.
Social networks can be organized into communities of closely connected nodes, a property known as modularity. Because diseases, information, and behaviors spread faster within communities than between communities, understanding modularity has broad implications for public policy, epidemiology and the social sciences. Explanations for community formation in social networks often incorporate the attributes of individual people, such as gender, ethnicity or shared activities. High modularity is also a property of large-scale social networks, where each node represents a population of individuals at a location, such as call flow between mobile phone towers. However, whether or not place-based attributes, including land cover and economic activity, can predict community membership for network nodes in large-scale networks remains unknown. We describe the pattern of modularity in a mobile phone communication network in the Dominican Republic, and use a linear discriminant analysis (LDA) to determine whether geographic context can explain community membership. Our results demonstrate that place-based attributes, including sugar cane production, urbanization, distance to the nearest airport, and wealth, correctly predicted community membership for over 70% of mobile phone towers. We observed a strongly positive correlation (r = 0.97) between the modularity score and the predictive ability of the LDA, suggesting that place-based attributes can accurately represent the processes driving modularity. In the absence of social network data, the methods we present can be used to predict community membership over large scales using solely place-based attributes.  相似文献   

6.
To determine if the songs of male prairie warblers could potentially reveal to female listeners information about the quality of singers, we compared various aspects of prairie warbler song structure and performance to attributes that might reflect a male singer's potential to enhance the fitness of his mate. We found that all the tested male attributes—arrival date, age, body size, annual survival, and fledging success—were associated with singing, most with multiple aspects of singing. Several of the song traits that were associated with potential indicators of male quality had also been found previously to be good predictors of female social mate choice. In particular, longer songs with longer elements, performed at lower frequency and with greater consistency, were associated with both female mate choice and potential indicators of quality. Thus, female prairie warblers may assess potential mates with the help of a set of song characteristics that collectively reveal an array of attributes that together indicate overall male quality.  相似文献   

7.
Neighborhood characteristics, such as healthy food availability, have been associated with consumption of healthy food. Little is known about the influence of the local food environment on other dietary choices, such as the decision to consume organic food. We analyzed the associations between organic produce consumption and demographic, socioeconomic and neighborhood characteristics in 4,064 participants aged 53–94 in the Multi-Ethnic Study of Atherosclerosis using log-binomial regression models. Participants were classified as consuming organic produce if they reported eating organic fruits and vegetables either “sometimes” or “often or always”. Women were 21% more likely to consume organic produce than men (confidence interval [CI]: 1.12–1.30), and the likelihood of organic produce consumption was 13% less with each additional 10 years of age (CI: 0.84–0.91). Participants with higher education were significantly more likely to consume organic produce (prevalence ratios [PR] were 1.05 with a high school education, 1.39 with a bachelor''s degree and 1.68 with a graduate degree, with less than high school as the reference group [1.00]). Per capita household income was marginally associated with produce consumption (p = 0.06), with the highest income category more likely to consume organic produce. After adjustment for these individual factors, organic produce consumption was significantly associated with self-reported assessment of neighborhood produce availability (PR: 1.07, CI: 1.02–1.11), with an aggregated measure of community perception of the local food environment (PR: 1.08, CI: 1.00–1.17), and, to a lesser degree, with supermarket density (PR: 1.02: CI: 0.99–1.05). This research suggests that both individual-level characteristics and qualities of the local food environment are associated with having a diet that includes organic food.  相似文献   

8.

Background

Mental health, specifically mood/anxiety disorders, may be associated with value for health care attributes, but the association remains unclear. Examining the relation between mental health and attributes in a context where quality of care is low and exposure to suboptimal health conditions is increased, such as in Sub Saharan Africa (SSA), may elucidate the association.

Methodology/Principal Findings

We assessed whether preference weights for obstetric care attributes varied by mental health among 1006 women from Jimma Zone, Ethiopia, using estimates obtained through a discrete choice experiment (DCE), a method used to elicit preferences. Facilities were described by several attributes including provider attitude and performance and drug/equipment availability. Mental health measures included depressive symptoms and posttraumatic stress disorder (PTSD). We used Bayesian models to estimate preference weights for attributes and linear models to investigate whether these weights were associated with mental health. We found that women with high depressive symptoms valued a positive provider attitude [β = −0.43 (95% CI: −0.66, −0.21)] and drug/equipment availability [β = −0.43 (95% CI: −0.78, −0.07)] less compared to women without high depressive symptoms. Similar results were obtained for PTSD. Upon adjusting for both conditions, value for drug/equipment availability was lower only among women with both conditions [β = −0.89 (95% CI −1.4, −0.42)].

Conclusions/Significance

We found that women with psychopathology had lower preference weights for positive provider attitude and drug/equipment availability. Further work investigating why value for obstetric care attributes might vary by psychopathology in SSA is needed.  相似文献   

9.
Restoration is a young and swiftly developing field. It has been almost a decade since the inception of one of the field's foundational documents—the Society for Ecological Restoration International Primer on Ecological Restoration (Primer). Through a series of organized discussions, we assessed the Primer for its currency and relevance in the modern field of ecological restoration. We focused our assessment on the section entitled “The Nine Attributes of a Restored Ecosystem” and grouped each of the attributes into one of four categories: species composition, ecosystem function, ecosystem stability, and landscape context. We found that in the decade since the document's inception, the concepts, methods, goals, and thinking of ecological restoration have shifted significantly. We discuss each of the four categories in this light with the aim of offering comments and suggestions on options for updating the Primer. We also include a fifth category that we believe is increasingly acknowledged in ecological restoration: the human element. The Primer is an important document guiding the practice of restoration. We hope that this critical assessment contributes to its ongoing development and relevance and more generally to the development of restoration ecology, particularly in our current era of rapid environmental change.  相似文献   

10.
There are numerous statistical models for evaluating the degree of pollution in an environment. This study presents a fuzzy logic–based model—simple fuzzy classification (SFC)—for evaluating contamination of Ni and V species in the sediments of Nigeria's Ondo coastal area. Concentrations of five species of these metals were obtained from 10 sampling sites following sequential extractions from sediments. The results were formulated into a fuzzy membership function matrix based on three classifications relative to regulatory standards and sediments’ degree of contamination. The results of the SFC show that the estuary is moderately enriched by Ni species in a range of 61–84% and further introduction of Ni may shift its contamination level into the highly polluted category. The SFC results also show that the estuary is clean of V species contamination in a range of 77–99%. The Ni and V were associated with the organic specie notably at the crude oil exploration site and at the coastal discharge point. Crude oil exploration and domestic wastes discharges are notable sources of metal contaminations into the estuary. However, the salinity incursion from the coastal ocean and prevailing biogeochemistry affect the species in which the metals exist.  相似文献   

11.
Gao P  Song YX  Wang ZN  Xu YY  Tong LL  Zhu JL  Tang QC  Xu HM 《PloS one》2012,7(4):e35021

Objective

At present, only the number of metastatic lymph nodes (LNs+) is used for the pN category of AJCC TNM system for colon cancer. Recently, the ratio of metastatic to examined lymph nodes (LNR) has been reported to represent powerful independent predictive capacity in colon cancer. We sought to propose a novel category (nLN) which intergrades LNR and LNs+ into the AJCC staging system for colon cancer.

Design

34476 patients from the National Cancer Institute''s Surveillance, Epidemiology, and End Results (SEER) dataset with stage III colon cancer were reviewed. Harrell''s C statistic was used to evaluate the predictive capacity. The Cox proportional hazards model was used to construct a novel category.

Results

The LNR category had more predictive capacity than the pN category in whole groups of patients (Harrell''s C index: 0.6194 vs 0.6113, p = 0.003). Subgroup analysis showed that the LNR category was not better than pN category in predictive capacity if the number of lymph nodes examined was more than 13. We also found that there was significant survival heterogeneity among different pN categories at the same LNR category (P<0.001). The Harrell''s C index for our nLN category which intergrades LNR and LNs+ was 0.6228, which was significant higher than that of the pN category (Harrell''s C index: 0.6113, P<0.001) or LNR category (Harrell''s C index: 0.6194, P = 0.005), respectively.

Conclusion

To evaluate the prognosis of colon cancer, our nLN category which intergrades LNR with LNs+ is more accurate than the pN category or LNR category, respectively.  相似文献   

12.

Background

Theories of categorization make different predictions about the underlying processes used to represent categories. Episodic theories suggest that categories are represented in memory by storing previously encountered exemplars in memory. Prototype theories suggest that categories are represented in the form of a prototype independently of memory. A number of studies that show dissociations between categorization and recognition are often cited as evidence for the prototype account. These dissociations have compared recognition judgements made to one set of items to categorization judgements to a different set of items making a clear interpretation difficult. Instead of using different stimuli for different tests this experiment compares the processes by which participants make decisions about category membership in a prototype-distortion task and with recognition decisions about the same set of stimuli by examining the Event Related Potentials (ERPs) associated with them.

Method

Sixty-three participants were asked to make categorization or recognition decisions about stimuli that either formed an artificial category or that were category non-members. We examined the ERP components associated with both kinds of decision for pre-exposed and control participants.

Conclusion

In contrast to studies using different items we observed no behavioural differences between the two kinds of decision; participants were equally able to distinguish category members from non-members, regardless of whether they were performing a recognition or categorisation judgement. Interestingly, this did not interact with prior-exposure. However, the ERP data demonstrated that the early visual evoked response that discriminated category members from non-members was modulated by which judgement participants performed and whether they had been pre-exposed to category members. We conclude from this that any differences between categorization and recognition reflect differences in the information that participants focus on in the stimuli to make the judgements at test, rather than any differences in encoding or process.  相似文献   

13.
Analyzing the Indonesian Family Life Survey 2007, this paper estimates the value of relative height (relative to the spouse's height) in the marriage market of a developing country. The results indicate that the value of a 1 cm reduction in the husband's height relative to his wife's height is about 3% of his earnings. 3% of the mean of yearly earnings amounts to Rp. 492,000 or US$54 in 2007. That value is reduced to 1% when earnings-generating attributes are controlled for. This difference of 2% points can be considered the value that women attach to their husbands’ earnings-generating attributes; meanwhile, the remaining 1% suggests that there are still other attributes that women look for in male height.  相似文献   

14.
Studies increasingly show that social connectedness plays a key role in determining survival, in addition to natural and anthropogenic environmental factors. Few studies, however, integrated social, non-social and demographic data to elucidate what components of an animal''s socio-ecological environment are most important to their survival. Female giraffes (Giraffa camelopardalis) form structured societies with highly dynamic group membership but stable long-term associations. We examined the relative contributions of sociability (relationship strength, gregariousness and betweenness), together with those of the natural (food sources and vegetation types) and anthropogenic environment (distance from human settlements), to adult female giraffe survival. We tested predictions about the influence of sociability and natural and human factors at two social levels: the individual and the social community. Survival was primarily driven by individual- rather than community-level social factors. Gregariousness (the number of other females each individual was observed with on average) was most important in explaining variation in female adult survival, more than other social traits and any natural or anthropogenic environmental factors. For adult female giraffes, grouping with more other females, even as group membership frequently changes, is correlated with better survival, and this sociability appears to be more important than several attributes of their non-social environment.  相似文献   

15.
Categorization is an important cognitive process. However, the correct categorization of a stimulus is often challenging because categories can have overlapping boundaries. Whereas perceptual categorization has been extensively studied in vision, the analogous phenomenon in audition has yet to be systematically explored. Here, we test whether and how human subjects learn to use category distributions and prior probabilities, as well as whether subjects employ an optimal decision strategy when making auditory-category decisions. We asked subjects to classify the frequency of a tone burst into one of two overlapping, uniform categories according to the perceived tone frequency. We systematically varied the prior probability of presenting a tone burst with a frequency originating from one versus the other category. Most subjects learned these changes in prior probabilities early in testing and used this information to influence categorization. We also measured each subject''s frequency-discrimination thresholds (i.e., their sensory uncertainty levels). We tested each subject''s average behavior against variations of a Bayesian model that either led to optimal or sub-optimal decision behavior (i.e. probability matching). In both predicting and fitting each subject''s average behavior, we found that probability matching provided a better account of human decision behavior. The model fits confirmed that subjects were able to learn category prior probabilities and approximate forms of the category distributions. Finally, we systematically explored the potential ways that additional noise sources could influence categorization behavior. We found that an optimal decision strategy can produce probability-matching behavior if it utilized non-stationary category distributions and prior probabilities formed over a short stimulus history. Our work extends previous findings into the auditory domain and reformulates the issue of categorization in a manner that can help to interpret the results of previous research within a generative framework.  相似文献   

16.
Summary Several surveys have documented an association among species between habitat type and seed mass, suggesting that habitat attributes impose a direct selective force on seed mass. Previous comparative surveys, however, have not controlled for the statistical effects of shared phylogenetic history (at the genus or family level) and life form when evaluating the relationship between habitat and seed mass. This study of the Indiana Dunes angiosperm flora provides statistical control of genus and family membership by: (i) partitioning out the statistical effect of genus membership prior to measuring the effect of habitat on seed mass, and (ii) seeking an association between habitat and seed mass within eight genera (206 species) and ten families (366 species). To measure the associations between ecological factors, taxonomic membership and seed mass, I examined life form, phenological schedules and seed mass among species in 8 genera distributed among 13 habitat types (assigned to 1 of 4 categories of inferred water and light availability). One-way ANOVAS indicated that genus, life form, habitat, water/light category, the onset of flowering and the duration of flowering accounted for 71%, 51%, 10%, 4%, 14% and 14% of the variance in seed mass, respectively. However, multi-factor ANOVAS measured the variance in seed mass accounted for by each variable independently of the others: only genus explained a significant proportion (11%). Genus membership is strongly associated with the other ecological factors, accounting for the difference between one-way and multi-factor ANOVAS. Within the ecologically widespread genera and families of this study, there was no significant association between water/light category and seed mass, even though this association can be detected across taxa. Among congeners and confamilials, interspecific variation in seed mass (measured as the coefficient of variation) was as high within habitat types as among them, suggesting that habitats do not provide upper limits to the range of seed mass exhibited by the species within them. A previous study of 648 Indiana Dune species showed that species segregate among habitats on the basis of seed size; large-seeded species tend to occupy closed habitats and small-seeded species tend to inhabit open habitats. This segregation creates the ecologically meaningful observation that low-light habitats support larger-seeded species than high-light habitats, even though this pattern cannot be detected independently of taxonomic membership. Generalist taxa may occupy a wide range of habitats for reasons other than their seed size. If this is a common feature of ecological generalists, it may not be possible to detect an association between habitat and seed size independently of taxonomic membership.  相似文献   

17.
基于GIS的滨海盐渍化农田土壤空间变异及其分区管理   总被引:4,自引:0,他引:4  
针对滨海盐渍化农田盐碱瘠薄、土壤属性空间变异大、粗放管理效益低的现实,研究管理分区精准划分方法,采取差异化措施,提升盐渍化土地利用水平。该文以无棣县农田为研究区,采用网格法结合土地利用现状定点野外采样、室内化验分析获取土壤属性数据,运用ArcGIS 10.2地统计方法分析土壤属性的空间变异特征;在MATLAB R2016a中采用模糊c-均值聚类法(FCM)计算各样点的模糊隶属度,通过插值预测模糊隶属度的空间分布,基于最大隶属度原则进行分区;通过变异性分析和最小极差法(LSR)差异显著性检验,对分区结果进行精度验证。结果表明:无棣县农田土壤总体呈轻中度盐渍化,有效氮含量偏低,有机质、有效磷含量中等,速效钾含量较高;有机质、有效氮、有效磷、速效钾和含盐量呈中等变异性(变异系数25.0%-52.3%),空间变异性较大,应分区调控;速效钾、含盐量和pH的块金效应值小于25%,主要受土壤质地、地下水矿化度等结构因素影响,有机质、有效氮和有效磷的块金效应值在50%-75%之间,受耕作方式、施肥等人为因素影响较大。将全县农田划分为3类管理区,估算面积分别为2.56万hm2、1.76万hm2、3.24万hm2;各分区土壤养分变异系数分别为23.9%-51.5%、15.9%-50.3%、14.7%-33.0%,检验结果表明各分区间差异显著,而各分区内部变异性明显低于未分区。管理分区与土壤属性空间分布特征具有较高的拟合度,分区结果可以作为差异化管理的作业单元。研究结果为各分区内部统一、不同分区间差异化管理提供了依据,研究有助于推进滨海盐渍化农田精准化管理水平的提高。  相似文献   

18.
Oxygen depletion of lake and seawater is a serious condition with large implications for biodiversity. Therefore, in LCA, the potential oxygen demand of water emissions is estimated under the label eutrophication impact category. This impact category should contain the impact of water emissions on the total oxygen consumption in the receiving water. This means that it should include both primary and secondary oxygen consumption. In spite of this, the oxygen needed to oxidise ammonia has normally not been taken into account when quantifying the eutrophication impact category. In this paper, weighting factors for ammonium/ammonia are suggested for the eutrophication impact category. It is shown that, for treated wastewater, the amount of oxygen needed for nitrification of ammonia is important when compared to the potential eutrophication calculated using the current recommended weighting factors. These weighting factors take into account oxygen needed to oxidise the organic matter in the wastewater emission and that needed to degrade the algae potentially grown due to the emission of nutrients.  相似文献   

19.
Song YX  Gao P  Wang ZN  Liang JW  Sun Z  Wang MX  Dong YL  Wang XF  Xu HM 《PloS one》2012,7(3):e34087

Objective

The 7th edition of AJCC staging manual implicitly states that only T1 and T2 lesions that lack regional lymph node metastasis but have tumor deposit(s) will be classified in addition as N1c, though it is not consistent in that pN1c is also an option for pT3/T4a tumors in the staging table. Nevertheless, in this TNM classification, how to classify tumor deposits (TDs) in colorectal cancer patients with lymph node metastasis (LNM) and TDs simultaneously is still not clear. The aim of this study is to investigate the possibility of counting TDs as metastatic lymph nodes in TNM classification and to indentify its prognostic value for colorectal cancer patients.

Methods and Results

In this retrospective study, 513 cases of colorectal cancer with LNM were reviewed. We proposed a novel pN (npN) category in which TDs were counted as metastatic lymph nodes in the TNM classification. Cancer-specific survival according to the npN or pN category was analyzed using Kaplan-Meier survival curves. Univariate and multivariate analyses were performed to indentify significant prognostic factors. Harrell''s C statistic was used to test the predictive capacity of the prognostic models. The results revealed that the TD was a significant prognostic factor in colorectal cancer. Univariate and multivariate analyses uniformly indicated that the npN category was significantly correlated with prognosis. The results of Harrell''s C statistical analysis demonstrated that the npN category exhibited a superior predictive capacity compared to the pN category of the 7th edition TNM classification. Moreover, we also found no significant prognostic differences in patients with or without TD in the same npN categories.

Conclusions

The counting of TDs as metastatic lymph nodes in the TNM classification system is potentially superior to the classification in the 7th edition of the TNM staging system to assess prognosis and survival for colorectal cancer patients.  相似文献   

20.
生态系统服务价值定量化评价及其空间制图可以为确定生态系统文化服务(CES)优先保护地域提供有效途径.本研究以上海共青森林公园为例,采用问卷和结构式访谈结合参与式制图(PPGIS)方法,将非货币CES价值和空间信息结合,把丰度、多样性和稀有度指数转化为空间生态综合指数,定量评价了CES价值及其空间分布,识别出优先保护地域.结果表明: 不同景观类型的CES价值分布不同,共青森林公园美学服务价值主要分布在相对开阔的草地、滨水和疏林区,滨水区具有较高的社会关系和灵感价值.多样性较高价值区主要沿湖滨水分布,而稀有度价值较高区域多分布在森林和草地区.通过对8个梯度阈值生态指数的最高值区域进行叠加,验证了25%为有效划分阈值,能够更准确划分公园CES优先保护范围.该方法引入公众参与,实现了使用者体验的空间化、定量化、类型化,建立了景观、空间、体验的地域关系,可为城市保护地优先保护地域划分及其规划管理提供重要依据.  相似文献   

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