2,576 research outputs found
Use of a Self-Fed, Small-Package Protein Supplement for Beef Cows Post-Weaning
A 2-year supplementation study conducted at Miles City, MT from mid-October to mid-December in 2007 and 2008 evaluated responses of beef cows (n = 141 in 2007, n = 138 in 2008; avg BW = 546 ± 5.2 kg) grazing dormant native range (8.8% CP, 64% NDF, 71% IVDMD) to two different supplementation strategies. Each year, cows were stratified by age and weight at weaning and then assigned to one of two supplements: 1) self-fed loose mineral mix (MIN) or 2) self-fed mineral plus high-bypass protein sources (MIN+PRO; 50% mineral mix, 25% feather meal, 25% fish meal). Target intakes were 70 g/d for MIN and 140 g/d for MIN+PRO. Cows were weighed and hip height and girth measurements were taken at the beginning and end of the 60-d studies. Weight-to-height and weight-to-girth ratio changes were calculated. Data were analyzed with supplement, cow age (2, 3, and 4+), year, and their interactions in the model. In 2007, cows fed MIN consumed 28 g/d and MIN+PRO cows consumed 93 g/d, which was lower than the target amount for both supplements. In 2008, MIN cows again failed to consume the target amount (13 g/d), while MIN+PRO cows consumed just over target amount (160 g/d). Cows lost similar (P = 0.70) amounts of weight during the study regardless of supplement treatment (-22 and -25 ± 5 kg for MIN and MIN+PRO, respectively). Likewise, weight-toheight ratio change (-0.25 and -0.25 ± 0.04) and weight-togirth ratio change (-0.10 and -0.12 ± 0.02) were similar (P ≥ 0.60) for MIN and MIN+PRO cows, respectively. Year × cow age interactions (P ≤ 0.08) were observed for weight change and weight-to-height ratio change. Two- and 3-yrold cows lost less weight in 2008 than in 2007, while mature cows lost similar amounts of weight in both years. All cows exhibited less change in weight-to-height ratio in 2008 compared to 2007, with the difference between years most pronounced in younger cows. Protein supplementation at this level did not impact cow performance; however, forage quality was higher than expected, which may have contributed to the lack of response to supplementation with the mineral-protein mix
Use of a Self-Fed, Small-Package Protein Supplement for Beef Cows Post-Weaning
A 2-year supplementation study conducted at Miles City, MT from mid-October to mid-December in 2007 and 2008 evaluated responses of beef cows (n = 141 in 2007, n = 138 in 2008; avg BW = 546 ± 5.2 kg) grazing dormant native range (8.8% CP, 64% NDF, 71% IVDMD) to two different supplementation strategies. Each year, cows were stratified by age and weight at weaning and then assigned to one of two supplements: 1) self-fed loose mineral mix (MIN) or 2) self-fed mineral plus high-bypass protein sources (MIN+PRO; 50% mineral mix, 25% feather meal, 25% fish meal). Target intakes were 70 g/d for MIN and 140 g/d for MIN+PRO. Cows were weighed and hip height and girth measurements were taken at the beginning and end of the 60-d studies. Weight-to-height and weight-to-girth ratio changes were calculated. Data were analyzed with supplement, cow age (2, 3, and 4+), year, and their interactions in the model. In 2007, cows fed MIN consumed 28 g/d and MIN+PRO cows consumed 93 g/d, which was lower than the target amount for both supplements. In 2008, MIN cows again failed to consume the target amount (13 g/d), while MIN+PRO cows consumed just over target amount (160 g/d). Cows lost similar (P = 0.70) amounts of weight during the study regardless of supplement treatment (-22 and -25 ± 5 kg for MIN and MIN+PRO, respectively). Likewise, weight-toheight ratio change (-0.25 and -0.25 ± 0.04) and weight-togirth ratio change (-0.10 and -0.12 ± 0.02) were similar (P ≥ 0.60) for MIN and MIN+PRO cows, respectively. Year × cow age interactions (P ≤ 0.08) were observed for weight change and weight-to-height ratio change. Two- and 3-yrold cows lost less weight in 2008 than in 2007, while mature cows lost similar amounts of weight in both years. All cows exhibited less change in weight-to-height ratio in 2008 compared to 2007, with the difference between years most pronounced in younger cows. Protein supplementation at this level did not impact cow performance; however, forage quality was higher than expected, which may have contributed to the lack of response to supplementation with the mineral-protein mix
Addition-Deletion Networks
We study structural properties of growing networks where both addition and
deletion of nodes are possible. Our model network evolves via two independent
processes. With rate r, a node is added to the system and this node links to a
randomly selected existing node. With rate 1, a randomly selected node is
deleted, and its parent node inherits the links of its immediate descendants.
We show that the in-component size distribution decays algebraically, c_k ~
k^{-beta}, as k-->infty. The exponent beta=2+1/(r-1) varies continuously with
the addition rate r. Structural properties of the network including the height
distribution, the diameter of the network, the average distance between two
nodes, and the fraction of dangling nodes are also obtained analytically.
Interestingly, the deletion process leads to a giant hub, a single node with a
macroscopic degree whereas all other nodes have a microscopic degree.Comment: 8 pages, 5 figure
Rank Statistics in Biological Evolution
We present a statistical analysis of biological evolution processes.
Specifically, we study the stochastic replication-mutation-death model where
the population of a species may grow or shrink by birth or death, respectively,
and additionally, mutations lead to the creation of new species. We rank the
various species by the chronological order by which they originate. The average
population N_k of the kth species decays algebraically with rank, N_k ~ M^{mu}
k^{-mu}, where M is the average total population. The characteristic exponent
mu=(alpha-gamma)/(alpha+beta-gamma)$ depends on alpha, beta, and gamma, the
replication, mutation, and death rates. Furthermore, the average population P_k
of all descendants of the kth species has a universal algebraic behavior, P_k ~
M/k.Comment: 4 pages, 3 figure
Formation and Interaction of Membrane Tubes
We show that the formation of membrane tubes (or membrane tethers), which is
a crucial step in many biological processes, is highly non-trivial and involves
first order shape transitions. The force exerted by an emerging tube is a
non-monotonic function of its length. We point out that tubes attract each
other, which eventually leads to their coalescence. We also show that detached
tubes behave like semiflexible filaments with a rather short persistence
length. We suggest that these properties play an important role in the
formation and structure of tubular organelles.Comment: 4 pages, 3 figure
Modeling long-range memory with stationary Markovian processes
In this paper we give explicit examples of power-law correlated stationary
Markovian processes y(t) where the stationary pdf shows tails which are
gaussian or exponential. These processes are obtained by simply performing a
coordinate transformation of a specific power-law correlated additive process
x(t), already known in the literature, whose pdf shows power-law tails 1/x^a.
We give analytical and numerical evidence that although the new processes (i)
are Markovian and (ii) have gaussian or exponential tails their autocorrelation
function still shows a power-law decay =1/T^b where b grows with a
with a law which is compatible with b=a/2-c, where c is a numerical constant.
When a<2(1+c) the process y(t), although Markovian, is long-range correlated.
Our results help in clarifying that even in the context of Markovian processes
long-range dependencies are not necessarily associated to the occurrence of
extreme events. Moreover, our results can be relevant in the modeling of
complex systems with long memory. In fact, we provide simple processes
associated to Langevin equations thus showing that long-memory effects can be
modeled in the context of continuous time stationary Markovian processes.Comment: 5 figure
Constructing transnational solidarity: the role of campaign governance
Our inductive study of two transnational labour solidarity efforts focuses on the role of campaign governance. Specifically, we study contrasting campaign strategies, tactics and coalition structures in campaigns by two global union federations, UNI Global Union and the IUF, contextualized in terms of how these campaigns unfolded in India. Our contribution consists of two arguments. The first is that a degree of internal consistency amongst different campaign elements is important for success, and the second is that a mode of articulation that allows for local concerns in affiliate countries to find voice in global campaigns is more likely to result in concrete gains at the local level
Granulocyte-macrophage colony-stimulating factor-induced protein tyrosine phosphorylation of microtubule-associated protein kinase in human neutrophils.
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