Nitric oxide (NO) is an important signaling molecule that is involved in a wide range of physiological and pathological events in biology. Metal coordination chemistry, especially with iron, is at the heart of many biological transformations involving NO. A series of heme proteins, nitric oxide synthases (NOS), soluble guanylate cyclase (sGC), and nitrophorins, are responsible for the biosynthesis, sensing, and transport of NO.
View Article and Find Full Text PDFBlue copper proteins have a constrained Cu(II) geometry that has proven difficult to recapitulate outside native cupredoxin folds. Previous work has successfully designed green copper proteins which could be tuned blue using exogenous ligands, but the question of how one can create a self-contained blue copper site within a de novo scaffold, especially one removed from a cupredoxin fold, remained. We have recently reported a red copper protein site within a three helical bundle scaffold which we later revisited and determined to be a nitrosocyanin mimic, with a CuHisCysGlu binding site.
View Article and Find Full Text PDFObjectives: This study investigated the feasibility, safety, and the potential benefit of faster hemostasis with the distal transradial artery access (TRA).
Background: TRA has been shown to be associated with lower bleeding and vascular complications. Limited data are available regarding the new technique of accessing the distal radial artery in the anatomical snuffbox.
Landscape characteristics and social behavior can affect the foraging patterns of seed-dependent animals. We examine the movement of acorns from valley oak (Quercus lobata) trees to granaries maintained by acorn woodpeckers (Melanerpes formicivorus) in two California oak savanna-woodlands differing in the distribution of Q. lobata within each site.
View Article and Find Full Text PDFThe reproductive system is extremely susceptible to insults from exposure to exogenous steroids during development. Excess prenatal testosterone exposure programs neuroendocrine, ovarian, and metabolic deficits in the female, features seen in women with polycystic ovary disease. The objective of this study was to determine whether prenatal testosterone excess also disrupts the male reproductive system, using sheep as a model system.
View Article and Find Full Text PDFIn this paper, an index for measuring fragility of proportional integral derivative (PID) controllers is proposed. This index relates the losses of robustness of the control loop when controller parameters change, to the nominal robustness of the control loop. Furthermore, it defines when a PID controller is fragile, nonfragile or resilient.
View Article and Find Full Text PDFThe granulocyte-macrophage colony stimulating factor (GM-CSF) is a pleiotropic cytokine capable of stimulating proliferation, maturation and function of hematopoietic cells. Receptors for this cytokine are composed of two subunits, alpha and beta, and are expressed on myeloid progenitors and mature mononuclear phagocytes, monocytes, eosinophils and neutrophils, as well as in other nonhematopietic cells. We have recently demonstrated that bull spermatozoa express functional GM-CSF receptors that signal for increased glucose and Vitamin C uptake.
View Article and Find Full Text PDFSperm migration in estrous cervical mucus can be used to measure the ability of spermatozoa to migrate through the genital tract. The relationship of this test with the sperm colonization of the isthmus, and its impact on fertility has not been evaluated in goats. Our objectives were to determine the differences among spermatozoa of different bucks in their ability to penetrate homologous cervical mucus in vitro and to determine the relationship between sperm displacement through cervical mucus and the ability of spermatozoa to colonize the oviduct and penetrate IVM oocytes, in vivo.
View Article and Find Full Text PDFAn alternative to conventional in vivo validation of sperm assays might be to assess the fertilization rate of multiple oocytes transferred to the oviducts of inseminated females. Increasing the number of oocytes increases the egg-sperm ratio in the oviduct under an unaltered endocrine milieu, setting the basis for picking up statistical differences between treatments in small populations. The study evaluated the model by transferring oocytes to females inseminated under conditions that are known to modify the fertilization rate in the field.
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