409 research outputs found
A CENSORED SYSTEM ESTIMATION OF HISPANIC HOUSEHOLD FOOD CONSUMPTION PATTERNS
A system of nine censored Engel curve equations was estimated for Hispanic households in the U.S.: grains, vegetables, fruits, milk, meat, legumes, fats, sugar, and beverages. Income and household size elasticities, with their respective confidence intervals, are reported and the results compared with other ethnic groups in the U.S.Food Consumption/Nutrition/Food Safety,
COMPARISONS OF HISPANIC HOUSEHOLDS' DEMAND FOR MEATS WITH OTHER ETHNIC GROUPS
The objective of this research was to analyze the demand patterns of Hispanic households for meats in comparison with other ethnic groups using data from the 1998 Consumer Expenditure Survey. A system of demand equations of the LinQuad form were estimated for ten meat products using an incomplete system of censored equations. Hispanic households showed a clear preference for beef. Price, income, and household-size elasticities were estimated for each meat product by ethnic group. The demand for ground beef was the most income-inelastic product regardless of ethnicity. Household size had a positive effect on the probability of consuming a particular meat product but a negative effect on actual item expenditures.Consumer/Household Economics, Demand and Price Analysis,
On the eigenvalues of Cayley graphs on the symmetric group generated by a complete multipartite set of transpositions
Given a finite simple graph \cG with vertices, we can construct the
Cayley graph on the symmetric group generated by the edges of \cG,
interpreted as transpositions. We show that, if \cG is complete multipartite,
the eigenvalues of the Laplacian of \Cay(\cG) have a simple expression in
terms of the irreducible characters of transpositions, and of the
Littlewood-Richardson coefficients. As a consequence we can prove that the
Laplacians of \cG and of \Cay(\cG) have the same first nontrivial
eigenvalue. This is equivalent to saying that Aldous's conjecture, asserting
that the random walk and the interchange process have the same spectral gap,
holds for complete multipartite graphs.Comment: 29 pages. Includes modification which appear on the published version
in J. Algebraic Combi
Vortex corrections to universal scaling of magnetic fluctuations in 2D XY model
The vortex contribution to the probability density function of longitudinal
magnetization fluctuations is examined in finite 2D XY systems close to the
Kosterlitz-Thouless-Berezinskii transition temperature. Within the temperature
range studied their relevance is limited to rare fluctuations, where they
increase the probability of events exceeding four standard deviations below the
mean magnetization.Comment: 6 pages, 4 figures. Refs adde
The in vivo Therapeutic Effect of Free Wanderer Powder (逍 遙 散 xiāo yáo sǎn, Xiaoyaosan) on Mice with 4T1 Cell Induced Breast Cancer Model
ABSTRACTIn the present study, we investigated the therapeutic effect of a classical TCM formula, Free Wanderer Powder (逍遙散 xiāo yáo sǎn), in a breast cancer mouse model induced with estrogen-insensitive breast cancer 4T1 cells. Ovariectomized Balb/c mice (6-8 weeks) or sham mice were injected into the fourth mammary fat pad with 4T1 cells in which tumors were palpable 7days after injection. On the eighth day, the mice were divided into 4 groups and tubefed daily with vehicle, Free Wanderer Powder (逍遙散 xiāo yáo sǎn) formula or tamoxifen for 28days. Tumor growth inhibition and the decrease of the average tumor mass were most evident in mice treated with Free Wanderer Powder (逍遙散 xiāo yáo sǎn). Free Wanderer Powder (逍遙散 xiāo yáo sǎn) treatment significantly reduced Bcl-2 and elevated Bax and p53 protein expressions in breast cancer tumor. These results were further confirmed by immunohistochemisty. Tamoxifen could decrease spleen mass and Bcl-2 protein expression, increase the Bax protein expression as well as exert uterotrophic effects by increasing uterus index and inducing the gene expressions in the uterus. Taken together, these results show that Free Wanderer Powder (逍遙散 xiāo yáo sǎn) treatment induced apoptosis at protein level and inhibited the tumor growth in 4T1-induced ovariectomized Balb/c female mice, indicating the possibility of its future use for treatment of estrogen-insensitive breast caner
Parental Influence on Child and Adolescent Physical Activity Level: A Meta-Analysis
Parents are often regarded as one of the significant social agents who are important to the participation of physical activity (PA) among children and adolescents. However, within the literature, the relationships between parental influences and child and adolescent PA have been inconclusive and discordant. The purpose of this meta-analysis was to quantify and synthesize the associations between parental social influences (positive parental influence, punishment, and discouragement) and the PA level of children and adolescents. Through a systematic literature search using PsycINFO, Web of Science, PubMed, ProQuest, and SPORTDiscus databases, we identified 112 eligible studies and subsequently extracted 741 effect sizes for our analysis. Multilevel meta-analysis showed that the corrected zero-order correlation of positive parental influence was positive and statistically significant, r = 0.202, SE = 0.014, t = 14.975, p \u3c 0.001, 95% confidence interval (CI) = [0.176, 0.228]. Further moderation analysis also found that this was significantly moderated by parental gender (maternal vs. paternal), respondent of influence measure (parent-reported vs. child-reported), and type of PA measure (subjective vs. objective). The corrected zero-order correlations of negative parental influences (i.e., punishment and discouragement) were not statistically significant, and no significant moderation effects were observed. The findings of our meta-analysis showed that children and adolescents had higher PA levels when their parents supported PA participation by exerting positive social influence. Punishment and discouragement against PA by parents did not appear to be significantly associated with the PA level of children and adolescents. The findings of negative parental social influence were mixed and required further investigations
The geometry of spontaneous spiking in neuronal networks
The mathematical theory of pattern formation in electrically coupled networks
of excitable neurons forced by small noise is presented in this work. Using the
Freidlin-Wentzell large deviation theory for randomly perturbed dynamical
systems and the elements of the algebraic graph theory, we identify and analyze
the main regimes in the network dynamics in terms of the key control
parameters: excitability, coupling strength, and network topology. The analysis
reveals the geometry of spontaneous dynamics in electrically coupled network.
Specifically, we show that the location of the minima of a certain continuous
function on the surface of the unit n-cube encodes the most likely activity
patterns generated by the network. By studying how the minima of this function
evolve under the variation of the coupling strength, we describe the principal
transformations in the network dynamics. The minimization problem is also used
for the quantitative description of the main dynamical regimes and transitions
between them. In particular, for the weak and strong coupling regimes, we
present asymptotic formulas for the network activity rate as a function of the
coupling strength and the degree of the network. The variational analysis is
complemented by the stability analysis of the synchronous state in the strong
coupling regime. The stability estimates reveal the contribution of the network
connectivity and the properties of the cycle subspace associated with the graph
of the network to its synchronization properties. This work is motivated by the
experimental and modeling studies of the ensemble of neurons in the Locus
Coeruleus, a nucleus in the brainstem involved in the regulation of cognitive
performance and behavior
Vertex functions for d-wave mesons in the light-front approach
While the light-front quark model (LFQM) is employed to calculate hadronic
transition matrix elements, the vertex functions must be pre-determined. In
this work we derive the vertex functions for all d-wave states in this model.
Especially, since both of and are mesons, the Lorentz
structures of their vertex functions are the same. Thus when one needs to study
the processes where is involved, all the corresponding formulas for
states can be directly applied, only the coefficient of the vertex
function should be replaced by that for . The results would be useful
for studying the newly observed resonances which are supposed to be d-wave
mesons and furthermore the possible 2S-1D mixing in with the LFQM.Comment: 12 pages, 2 figures, some typos corrected and more discussions added.
Accepted by EPJ
- …