116 research outputs found
Escherichia coli induces apoptosis and proliferation of mammary cells
Mammary cell apoptosis and proliferation were assessed after injection of Escherichia coli into the left mammary quarters of six cows. Bacteriological analysis of foremilk samples revealed coliform infection in the injected quarters of four cows. Milk somatic cell counts increased in these quarters and peaked at 24 h after bacterial injection. Body temperature also increased, peaking at 12 h postinjection, The number of apoptotic cells was significantly higher in the mastitic tissue than in the uninfected control. Expression of Bax and interleukin-1 beta converting enzyme increased in the mastitic tissue at 24 h and 72 h postinfection, whereas Bcl-2 expression decreased at 24 h but did not differ significantly from the control at 72 h postinfection, Induction of matrix metalloproteinase-g, stromelysin-1 and urokinase-type plasminogen activator was also observed in the mastitic tissue. Moreover, cell proliferation increased in the infected tissue, These results demonstrate that Escherichia coli-induced mastitis promotes apoptosis and cell proliferation
Phenology of Scramble Polygyny in a Wild Population of Chrysolemid Beetles: The Opportunity for and the Strength of Sexual Selection
Recent debate has highlighted the importance of estimating both the strength of sexual selection on phenotypic traits, and the opportunity for sexual selection. We describe seasonal fluctuations in mating dynamics of Leptinotarsa undecimlineata (Coleoptera: Chrysomelidae). We compared several estimates of the opportunity for, and the strength of, sexual selection and male precopulatory competition over the reproductive season. First, using a null model, we suggest that the ratio between observed values of the opportunity for sexual selections and their expected value under random mating results in unbiased estimates of the actual nonrandom mating behavior of the population. Second, we found that estimates for the whole reproductive season often misrepresent the actual value at any given time period. Third, mating differentials on male size and mobility, frequency of male fighting and three estimates of the opportunity for sexual selection provide contrasting but complementary information. More intense sexual selection associated to male mobility, but not to male size, was observed in periods with high opportunity for sexual selection and high frequency of male fights. Fourth, based on parameters of spatial and temporal aggregation of female receptivity, we describe the mating system of L. undecimlineata as a scramble mating polygyny in which the opportunity for sexual selection varies widely throughout the season, but the strength of sexual selection on male size remains fairly weak, while male mobility inversely covaries with mating success. We suggest that different estimates for the opportunity for, and intensity of, sexual selection should be applied in order to discriminate how different behavioral and demographic factors shape the reproductive dynamic of populations
Towards a Holographic Model of Color-Flavor Locking Phase
We demonstrate a holographic realization of color-flavor locking phase, using
N=4 SU(Nc) SYM coupled to N=2 Nf fundamental hypermultiplets as an example. The
gravity dual consists of Nc D3-branes and Nf D7-branes with world volume gauge
field representing the baryon density. Treating a small number \tilde{N}c << Nc
of D3-branes as Yang-Mills instantons on the D7-branes, we consider possible
potential(s) on their moduli space or equivalently the Higgs branch. We show
that a non-trivial potential can be generated by including the backreaction of
the baryonic density on the D7-branes, this dynamically drives the instantons
(= D3-branes) into dissolution. We interpret this as a color-flavor locking
since the size of the instanton is the squark vev, and study the symmetry
breaking patterns. Extending to finite temperature setup, we demonstrate that
color-flavor locking persists, and the thermal effect provides additional
structures in the phase diagram.Comment: 1+38 pages, 6 eps figures; typos corrected, acknowledgment and
references added, discussions in sections 3.1 and 4.3 improve
Cardiovascular risks and elevation of serum DHT vary by route of testosterone administration: a systematic review and meta-analysis
Drug–Drug Interactions Between the Anti-Hepatitis C Virus 3D Regimen of Ombitasvir, Paritaprevir/Ritonavir, and Dasabuvir and Eight Commonly Used Medications in Healthy Volunteers
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