Uterine infusion of bacteria alters the transcriptome of bovine oocytes

Postpartum uterine infection reduces fertility in dairy cattle; however, the mechanisms of uterine infection‐mediated infertility are unknown. Paradoxically, infection‐induced infertility persists after the resolution of disease. Oocytes are a finite resource, which are present at various stages of development during uterine infection. It is likely that oocyte development is influenced by uterine infection‐induced changes to the follicular microenvironment. To better understand the impact of infection on oocyte quality we employed global transcriptomics of oocytes collected from heifers after receiving intrauterine infusion of pathogenic Escherichia coli and Trueperella pyogenes . We hypothesized that the oocyte transcriptome would be altered in response to intrauterine infection. A total of 452 differentially expressed genes were identified in oocytes collected from heifers 4 days after bacteria infusion compared to vehicle infusion, while 539 differentially expressed genes were identified in oocytes collected from heifers 60 days after bacteria infusion. Only 42 genes were differentially expressed in bacteria‐infused heifers at both Day 4 and Day 60. Interferon, HMGB1, ILK, IL‐6, and TGF‐beta signaling pathways were downregulated in oocytes collected at Day 4 from bacteria‐infused heifers, while interferon, ILK, and IL‐6 signaling were upregulated in oocytes collected at Day 60 from bacteria‐infused heifers. These data suggest that bacterial infusion alters the oocyte transcriptome differently at Day 4 and Day 60, suggesting different follicle stages are susceptible to damage. Characterizing the long‐term impacts of uterine infection on the oocyte transcriptome aids in our understanding of how infection causes infertility in dairy cattle

Saints, heroes, sages, and villains

This essay explores the question of how to be good. My starting point is a thesis about moral worth that I’ve defended in the past: roughly, that an action is morally worthy if and only it is performed for the reasons why it is right. While I think that account gets at one important sense of moral goodness, I argue here that it fails to capture several ways of being worthy of admiration on moral grounds. Moral goodness is more multi-faceted. My title is intended to capture that multi-facetedness: the essay examines saintliness, heroism, and sagacity. The variety of our common-sense moral ideals underscores the inadequacy of any one account of moral admirableness, and I hope to illuminate the distinct roles these ideals play in our everyday understanding of goodness. Along the way, I give an account of what makes actions heroic, of whether such actions are supererogatory, and of what, if anything, is wrong with moral deference. At the close of the essay, I begin to explore the flipside of these ideals: villainy

Diagnosing students' difficulties in learning mathematics

This study considers the results of a diagnostic test of student difficulty and contrasts the difference in performance between the lower attaining quartile and the higher quartile. It illustrates a difference in qualitative thinking between those who succeed and those who fail in mathematics, illustrating a theory that those who fail are performing a more difficult type of mathematics (coordinating procedures) than those who succeed (manipulating concepts). Students who have to coordinate or reverse processes in time will encounter far greater difficulty than those who can manipulate symbols in a flexible way. The consequences of such a dichotomy and implications for remediation are then considered

Reconstruction of water ice: the neglected process OH + OH → H2O + O

Producción CientíficaContext. Although H2O is the most important molecular material found in the solid state in the interstellar medium, the chemical routes leading to ice through surface reactions are still a matter of discussion. Three reaction pathways proposed in the past are at the heart of current research: hydrogenation of atomic oxygen, molecular oxygen, and ozone. The reaction network finally leads to a small number of processes giving H2O: H + OH, H2 + OH, and H + H2O2. To these processes, OH + OH should be added. It is known to be efficient in atmospheric chemistry and takes the irradiations of the interstellar grains into account that, directly or indirectly, create a number of OH radicals on and in the icy mantles. Aims. We study the role of the existing ice in its own reconstruction after it is destroyed by the constant irradiation of interstellar grains and focus on the OH + OH reaction in the triplet state. Methods. We used numerical simulations with a high level of coupled cluster ab initio calculations for small water aggregates and methods relevant to density functional theory for extended systems, including a periodic description in the case of solid water of infinite dimensions. Results. OH + OH → H2O + O reaction profiles are reported that take the involvement of an increasing number of H2O support molecules into account. It is found that the top of the barrier opposing the reaction gradually decreases with the number of supporting H2O and falls below the level of the reactants for H2O layers or solid water. Conclusions. In contrast to the gas phase, the reaction is barrierless on water ice. By adding a reconstructed H2O molecule and a free oxygen atom at the surface of the remaining ice, this reaction leaves open the possibility of the ice reconstruction

Origin of molecular oxygen in Comet 67P/Churyumov-Gerasimenko

Molecular oxygen has been detected in the coma of comet 67P/Churyumov-Gerasimenko with abundances in the 1-10% range by the ROSINA-DFMS instrument on board the Rosetta spacecraft. Here we find that the radiolysis of icy grains in low-density environments such as the presolar cloud may induce the production of large amounts of molecular oxygen. We also show that molecular oxygen can be efficiently trapped in clathrates formed in the protosolar nebula, and that its incorporation as crystalline ice is highly implausible because this would imply much larger abundances of Ar and N2 than those observed in the coma. Assuming that radiolysis has been the only O2 production mechanism at work, we conclude that the formation of comet 67P/Churyumov-Gerasimenko is possible in a dense and early protosolar nebula in the framework of two extreme scenarios: (1) agglomeration from pristine amorphous icy grains/particles formed in ISM and (2) agglomeration from clathrates that formed during the disk's cooling. The former scenario is found consistent with the strong correlation between O2 and H2O observed in 67P/C-G's coma while the latter scenario requires that clathrates formed from ISM icy grains that crystallized when entering the protosolar nebula.Comment: The Astrophysical Journal Letters, in pres

Adsorption energy and spin state of first-row transition metals adsorbed on MgO(100)

Slab and cluster model spin-polarized calculations have been carried out to study various properties of isolated first-row transition metal atoms adsorbed on the anionic sites of the regular MgO(100) surface. The calculated adsorption energies follow the trend of the metal cohesive energies, indicating that the changes in the metal-support and metal-metal interactions along the series are dominated by atomic properties. In all cases, except for Ni at the generalized gradient approximation level, the number of unpaired electron is maintained as in the isolated metal atom. The energy required to change the atomic state from high to low spin has been computed using the PW91 and B3LYP density-functional-theory-based methods. PW91 fails to predict the proper ground state of V and Ni, but the results for the isolated and adsorbed atom are consistent within the method. B3LYP properly predicts the ground state of all first-row transition atom the high- to low-spin transition considered is comparable to experiment. In all cases, the interaction with the surface results in a reduced high- to low-spin transition energy

Egalitarian justice and expected value

According to all-luck egalitarianism, the differential distributive effects of both brute luck, which defines the outcome of risks which are not deliberately taken, and option luck, which defines the outcome of deliberate gambles, are unjust. Exactly how to correct the effects of option luck is, however, a complex issue. This article argues that (a) option luck should be neutralized not just by correcting luck among gamblers, but among the community as a whole, because it would be unfair for gamblers as a group to be disadvantaged relative to non-gamblers by bad option luck; (b) individuals should receive the warranted expected results of their gambles, except insofar as individuals blamelessly lacked the ability to ascertain which expectations were warranted; and (c) where societal resources are insufficient to deliver expected results to gamblers, gamblers should receive a lesser distributive share which is in proportion to the expected results. Where all-luck egalitarianism is understood in this way, it allows risk-takers to impose externalities on non-risk-takers, which seems counterintuitive. This may, however, be an advantage as it provides a luck egalitarian rationale for assisting ‘negligent victims’