Ovarian follicular dynamics during the interovulatory interval in Najdi goats

The pattern of growth and regression of ovarian follicles was characterized during the estrus cycle in 5 Najdi goats by daily ultrasonographic examination of the ovaries. Follicles 2 mm was measured and their relative locations within the ovary were determined to follow the sequential development of each individual follicle. Results indicated the presence of either four (n = 2 estrus cycles) or five (n = 3 estrus cycles) waves of follicular growth during the interovulatory interval. Each wave was characterized by the development of at least 1 large follicle (dominant) and a variable number of small follicles (subordinate). The mean number of follicular waves in Najdi goats is 4.6 ± 0.55, the days of wave emergence were on -0.8 ± 1.06, 3.2 ± 0.4, 7.0 ± 0.6, 12.3 ± 1.72 and 13.0 ± 1.63, for the first to fifth follicular waves, retrospectively. In goats with four or five follicular waves the dominant follicle in forth or fifth wave was ovulatory follicle. The mean number of ovulations in Najdi goats is 1.8 ± 0.4. Means of values were analyzed by repeated measures test using general linear model (GLM).Key words: Goats, estrous, follicles, ultrasonography

Reactivity of aminophenols in forming nitrogen-containing brown carbon from iron-catalyzed reactions

Nitrogen-containing organic carbon (NOC) in atmospheric particles is an important class of brown carbon (BrC). Redox active NOC like aminophenols received little attention in their ability to form BrC. Here we show that iron can catalyze dark oxidative oligomerization of o- and p-aminophenols under simulated aerosol and cloud conditions (pH 1–7, and ionic strength 0.01–1 M). Homogeneous aqueous phase reactions were conducted using soluble Fe(III), where particle growth/agglomeration were monitored using dynamic light scattering. Mass yield experiments of insoluble soot-like dark brown to black particles were as high as 40%. Hygroscopicity growth factors (κ) of these insoluble products under sub- and super-saturated conditions ranged from 0.4–0.6, higher than that of levoglucosan, a prominent proxy for biomass burning organic aerosol (BBOA). Soluble products analyzed using chromatography and mass spectrometry revealed the formation of ring coupling products of o- and p-aminophenols and their primary oxidation products. Heterogeneous reactions of aminophenol were also conducted using Arizona Test Dust (AZTD) under simulated aging conditions, and showed clear changes to optical properties, morphology, mixing state, and chemical composition. These results highlight the important role of iron redox chemistry in BrC formation under atmospherically relevant conditions