1,503 research outputs found
CONSUMER HOME-USE EVALUATION OF A DEVELOPED LEAN GROUND BEEF PRODUCT
This study reports findings on the acceptance of a new lean ground beef product. Tested products involved 1) a Developed Lean product (less than 10% fat plus quality enhancers), 2) a Lean product (less than 10% fat without quality enhancers), and 3) a Market product (slightly more than 20% fat). These products were home delivered on a rotating basis to a random sample of 91 households, one product each week for three weeks. Product traits were evaluated by the household meal preparer at three stages of home use: preparing (5 traits), cooking (3 traits), and eating (4 traits), and by other household members at the final consumption stage of eating. More favorable ratings were observed for both Developed Lean and Lean products over the Market product at the preparing and cooking stages. Ratings at the eating stage were similar between the Developed Lean and the Market products indicating a favorable response to the Developed Lean product.Consumer/Household Economics,
Climbing Escher's stairs: a way to approximate stability landscapes in multidimensional systems
Stability landscapes are useful for understanding the properties of dynamical
systems. These landscapes can be calculated from the system's dynamical
equations using the physical concept of scalar potential. Unfortunately, for
most biological systems with two or more state variables such potentials do not
exist. Here we use an analogy with art to provide an accessible explanation of
why this happens. Additionally, we introduce a numerical method for decomposing
differential equations into two terms: the gradient term that has an associated
potential, and the non-gradient term that lacks it. In regions of the state
space where the magnitude of the non-gradient term is small compared to the
gradient part, we use the gradient term to approximate the potential as
quasi-potential. The non-gradient to gradient ratio can be used to estimate the
local error introduced by our approximation. Both the algorithm and a
ready-to-use implementation in the form of an R package are provided
Five fundamental ways in which complex food webs may spiral out of control
Theory suggests that increasingly long, negative feedback loops of many interacting species may destabilize food webs as complexity increases. Less attention has, however, been paid to the specific ways in which these âdelayed negative feedbacksâ may affect the response of complex ecosystems to global environmental change. Here, we describe five fundamental ways in which these feedbacks might pave the way for abrupt, largeâscale transitions and species losses. By combining topological and bioenergetic models, we then proceed by showing that the likelihood of such transitions increases with the number of interacting species and/or when the combined effects of stabilizing network patterns approach the minimum required for stable coexistence. Our findings thus shift the question from the classical question of what makes complex, unaltered ecosystems stable to whether the effects of, known and unknown, stabilizing foodâweb patterns are sufficient to prevent abrupt, largeâscale transitions under global environmental change
When I Was A Dreamer / music by Egbert Van Alstyne; words by Little and Lewis
Cover: no. Illustrat.; Publisher: Jerome H. Remick and Co. (New York)https://egrove.olemiss.edu/sharris_c/1078/thumbnail.jp
Heptameric association of light-harvesting complex II trimers in partially solubilized photosystem II membranes
We report a structural characterization by electron microscopy and image analysis of a supramolecular complex consisting of seven trimeric light-harvesting complex II proteins, The complex was readily observed in partially-solubilized Tris-washed photosystem II membranes from spinach but was also found to occur, with a low frequency, in oxygen-evolving photosystem II membranes. The structure reveals sis peripheral trimers with the same rotational orientation and a central trimer with the opposite orientation. We conclude that the heptamer represents a naturally occurring aggregation state of part of the light-harvesting complex II trimers in the thylakoid membranes. (C) 1999 Federation of European Biochemical Societies.</p
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