The Geometry of Path Coefficients and Correlations

In the present paper, a generalized cosine formula is obtained for the difference between two angles in a k-dimensional Euclidean space, which is utilized to derive one of the principles of path analysis, namely, the correlation between two random variables is the sum of all connecting paths between them.     

A model of weak selection in the infinite alleles framework

Ewens (1972) proposed a model in the infinite allele framework for populations with neutrality of all alleles at a particular locus. This paper proposes a generalisation of Ewens' result for situations where there is a form of weak selection. The models considered here are continuous time, discrete state space Markov processes.     

Site frequency spectra from genomic SNP surveys

Genomic survey data now permit an unprecedented level of sensitivity in the detection of departures from canonical evolutionary models, including expansions in population size and selective sweeps. Here, we examine the effects of seemingly subtle differences among sampling distributions on goodness of fit analyses of site frequency spectra constructed from single nucleotide polymorphisms. Conditioning on the observation of exactly two alleles in a random sample results in a site frequency spectrum that is independent of the scaled rate of neutral substitution (θ). Other sampling distributions, including conditioning on a single mutational event in the sample genealogy or randomly selecting a single mutation from a genealogy with multiple mutations, have distinct site frequency spectra that show highly significant departures from the predictions of the biallelic model. Some aspects of data filtering may contribute to significant departures of site frequency spectra from expectation, apart from any violation of the standard neutral model.     

Anti-inflammatory and analgesic effects and molecular mechanisms of JCICM-6, a purified extract derived from an anti-arthritic Chinese herbal formula

The anti-inflammatory and anti-nociceptive effects and the molecular mechanisms of JCICM-6, a purified extract derived from an anti-arthritic Chinese herbal formula composed of Caulis Sinomenii, Aconiti laterralis Preparata, Rhizoma Curcumae longae, Radix Paeoniae albae, and Cortex Moutan, were examined for the first time. JCICM-6 was prepared using pharmaceutical extraction technology, purified by Amberlite XAD-7HP polymeric resin. Pharmacologically, in carrageenan-induced edema and carrageenan-evoked thermal hyperalgesia in paws of rats, the oral administration of JCICM-6 at dosages of 0.4, 0.8, and 1.6 g/kg demonstrated significant inhibition with a dose-dependent manner. Mechanistic studies showed that JCICM-6 effectively decreased the production of the pro-inflammatory cytokines of IL-6 and IL-1β and expression of COX-2 and iNOS proteins, and simultaneously elevated the level of anti-inflammatory cytokine IL-4 in the carrageenan-injected rat paw tissues and exudates. The positive reference drug, indomethacin at a dosage of 10 mg/kg, demonstrated inhibitory potency in both rat models, but it could not augment the production of IL-4, indicating JCICM-6 and indomethacin might possess different pharmacological properties and molecular mechanisms although both have anti-inflammatory and analgesic effects in rats. These results suggest that JCICM-6 would be a valuable candidate for further investigation as a new anti-arthritic drug.     

Polar Bear (Ursus maritimus) Adipose Tissue Fatty Acid Composition Compared to Fatty Acid Constituents of a Common Milk Replacer

This study compared the fatty acid composition of polar bear (Ursus maritimus) adipose tissue (n=2) to the fatty acid (FA) composition in published literature for maternal milk (n=3 samples) and a primary milk formula (liquid Esbilac, Pet Ag Inc., Hampshire, IL) commonly used in hand rearing, to look at possible dietary influences on ultimate body fat constituency. All tissue and commercial milk fatty acids were analyzed on a percent relative (% of fat) basis for consistency in reporting results and to make easier comparisons between samples with varying fat contents. Thirty‐eight individual fatty acid profiles were measured and the results tabulated into saturated, monounsaturated and polyunsaturated fats. The tissue adipose results for the two cubs had similar patterns throughout the assay. Saturated FA totals were 30% of the total fat, monounsaturated FA represented 50% of the total fat, and polyunsaturated FA was 15%. Similar fatty acid proportions were reported when comparing adipose to published data for maternal milk of polar bears. The most striking differences were between the commercial milk replacer (liquid Esbilac) and the tissue samples and maternal milk values. Esbilac FA summaries for saturated FAs were 24%, monounsaturated were 26%, and polyunsaturated comprised 50% of the total fat. Polyunsaturated fat in Esbilac is substantially higher than the tissue and milk scores. Although lipid sources from whole cream or half‐and‐half are used to increase the fat concentration of milk replacers for the hand‐reared polar bear cub, alternative ingredients such as fish oil may prove more suitable for this species, as their FA profiles better duplicate natural diets and resulting lipid stores in milk and adipose tissues of free‐ranging polar bears. Zoo Biol 0:1–11, 2006. © 2006 Wiley‐Liss, Inc.     

Effect of heat treatment on Cronobacter spp. in reconstituted, dried infant formula: preparation guidelines for manufacturers

Aim:  To explore safe guidelines for manufacturers and consumers to prepare, handle and store dry infant formula (DIF) to protect infants against Cronobacter spp.
Methods and Results:  Selected strains (2.45, FSM 293, ATCC-12868, FSM-271) screened from 68 strains of Cronobacter spp . were used to study growth and survival in commercial DIF. Prototype growth patterns in Enterobacteriaceae enrichment broth (EEB) containing a cocktail comprised of ATCC 12868, ATCC 29004, ATCC 29544 and ATCC 51329 showed a rapid increase in cell count (2·0 log₁₀ to 6·2 log₁₀ CFU ml⁻¹). Infant formula provided a better protective environment for the cells of Cronobacter strains than did buffered peptone water . Experiments on survival in inoculated (10⁴–10⁶ CFU ml⁻¹) reconstituted infant formula (RIF), preparation temperature, the effect of preparation volume (one-serving or two-serving) and effect of storage at room temperature for up to 10 h provided information to develop consumer guidelines for DIF preparation and handling.
Conclusions:  Reconstituted DIF in water at >70°C in larger volumes, minimizing storage time before feeding and storing unused reconstituted formulate at <4°C, may reduce the risk of Cronobacter infection in infants.
Significance and Impact of the Study:  Meningitis, necrotizing enterocolitis and bacteremia in premature babies has been linked to contaminated milk powder and DIF; better handling practices may improve the safety of these foods for neonates.     

Molybdenum supply of very low-birth-weight premature infants during the first months of life

This explorative study was performed to assess basic data on the Mo metabolism of premature infants. Premature (n=18, gestational age ≤32 wk, birth weight ≤1500 g) and healthy formula-fed term infants (n=14) were nourished and corrected for gestational age, identically. Plasma was collected at 3, 16, and 52 wk and 72 h balances were performed at 3 wk of age. In the premature infants, these investigations were preceded by two balance studies and an initial plasma collection. Increased Mo intake and low relative urinary excretion resulted in a retention of 4.4 (0.99–7.77) μg Mo/kg initially in premature infants (median, range). Parallel plasma concentrations were 5.5 (2.5–7.3) μg Mo/L, declining to 2.36 (0.73–3.87) μg Mo/L at 4 wk. Term infants rendered 1.49 (0.29–1.7) μg Mo/L (p<0.05), with no significant differences later. It was concluded that the supplementation of formulas for premature infants with Mo should be recinded until there is evidence for its necessity.