PGRMC1 localization and putative function in the nucleolus of bovine granulosa cells and oocytes

Progesterone Receptor Membrane Component-1 (PGRMC1) is a highly conserved multifunctional protein that is found in numerous systems, including reproductive system. Interestingly, PGRMC1 is expressed at several intracellular locations, including the nucleolus. The aim of this study is to investigate the functional relationship between PGRMC1 and nucleolus. Immunofluorescence experiments confirmed PGRMC1's nucleolar localization in cultured bovine granulosa cells (bGC) and oocytes. Additional experiments conducted on bGC revealed that PGRMC1 co-localizes with nucleolin (NCL), a major nucleolar protein. Furthermore, small interfering RNA (RNAi) mediated gene-silencing experiments showed that when PGRMC1 expression was depleted, NCL translocated from the nucleolus to the nucleoplasm. Similarly, oxidative stress induced by hydrogen peroxide (H2O2) treatment, reduced PGRMC1 immunofluorescent signal in the nucleolus and increased NCL nucleoplasmic signal, when compared to non-treated cells. Although PGRMC1 influenced NCL localization, a direct interaction between these two proteins was not detected using in situ proximity ligation assay. This suggests the involvement of additional molecules in mediating the co-localization of PGRMC1 and nucleolin. Since nucleolin translocates into the nucleoplasm in response to various cellular stressors, PGRMC1's ability to regulate its localization within the nucleolus is likely an important component of mechanism by which cells response to stress. This concept is consistent with PGRMC1's well-described ability to promote ovarian cell survival and provides a rationale for future studies on PGRMC1, NCL and the molecular mechanism by which these two proteins protect against the adverse effect of cellular stressors, including oxidative stress

Effects of macrobenthos on sediment-water oxygen and ammonium fluxes. Final Report.

Sediments are an important location in determining the fate of nutrients entering the estuary. Role of sediments needs to be incorporated into water quality models. Purpose of this study was to estimate the portion of sediment oxygen consumption (SOC) and sediment ammonium (NH4+) release directly attributable to benthic invertebrates via the respiratory use of oxygen and catabolic release of ammonium. Samples were collected at 8 locations from August 1985 through November 1988. (PDF contains 45 pages

Macroinvertebrate diversity and abundance in two created wetlands in Ohio

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Niche segregation between two closely similar gammarids (Peracarida, Amphipoda) — native vs. naturalized non-native species

Closely similar species may occupy similar niches, but usually divergence can be found in one or more traits when they inhabit the same habitat. In this study, we examined how two co-occurring gammarids — the nativeGammarus fossarumand the naturalizedG. roeselii — are distributed among microhabitats, depending on their sympatric or allopatric distribution. We hypothesized that the larger body-sized species (G. roeselii), exploiting their advantages in competition, restrict smaller species to microhabitats with smaller particle sizes. Four headwaters were sampled in the Mecsek Mountains (SW Hungary) in May, July and October 2009, and 37 local scale environmental variables at each site were measured. AlthoughG. fossarumis smaller in size, significantly more individuals were collected from the more favourable lithal and biotic microhabitats, whereas a strong negative association was observed between the two species.Gammarus roeseliioccurred at sites characterized by degraded riparian vegetation, which indicates stronger anthropogenic impacts, but still has a disadvantage in competition in mountainous streams under anthropogenic influence.</jats:p

Estudo da fadiga de contato em engrenagens cilíndricas de dentes retos

Due to the resistance of automotive manufactures on apply ADI gear studies have been made to verify the performance of this material. Inside this context this work has a main objective the construction of contact fatigue test machine in gears and the comparison, related to the wear resistance, between spur-gears made of carburized and quenched AISI 8620 low steel and austempered ductile iron (ADI). These gears were supplied in two states of finish surface (by shaving or by machining). The developed equipment functions with the principle of the power recirculation and commonly called FZG. The wear experiments were performed in two stages of torque: 135 N.m (running-in) and 302 N.m (steady-state) and the gears have modified profile. After the accomplishment of the experiments, was possible verify that: (1) The damaged area of flanks, due to the phenomenon of pitting, at ADI gears was bigger than AISI 8620 low-alloy steel gears. (2) The comparisons between the roughness parameter in the supply state and after each period of the experiment shows that gears with surface finish by shaving have better load distribution and minor wear. (3) Lubricant regime at pitch diameter was the boundary for both manufacture process, but the film thickness parameter λ is higher for shaved gears, making the lubricant film thickness has major value, (4) The reduction effect the resistive area of contact due the presence of the graphite nodules in the contact fatigue resistance was evidenced, however surface finishing was more relevant than the distribution and size nodules.Devido à resistência dos fabricantes de automóveis quanto à utilização de engrenagens de FNA estudos tem sido feitos para averiguar o desempenho deste material em engrenagens. Dentro deste contexto esta dissertação tem como objetivos principais o desenvolvimento e construção de uma máquina de ensaios de fadiga de contato em engrenagens e a comparação quanto à resistência ao desgaste de engrenagens cilíndricas de dentes retos fabricadas em aço liga 8620 (cementado e temperado) e em ferro fundido nodular austêmperado (FNA). Estas engrenagens foram fornecidas em dois estados de acabamento superficial (shaving ou por fresamento). O equipamento desenvolvido funciona com o princípio de recirculação de potência e é comumente chamado de FZG. Os experimentos de desgaste têm sido feitos com dois estágios de torque: 135 N.m (running-in) e 302 N.m (steady-state) e as engrenagens são de perfil modificado. Após a realização dos ensaios, foi possível verificar que: (1) a área danificada dos flancos, devido ao fenômeno de pitting, das engrenagens de FNA foi maior do que das de aço AISI 8620; (2) a comparação entre os parâmetros de rugosidade nos estágio de fornecimento e após cada estágio do experimento mostra que as engrenagens com acabamento por shaving apresentam uma melhor distribuição da carga e um menor desgaste, (3) o regime de lubrificação na região do diâmetro primitivo durante os ensaios foi o limite (ou limítrofe) para ambos os processos de fabricação, porém o parâmetro de espessura de filme (λ) é maior para engrenagens fabricadas por shaving, fazendo com que a espessura do filme lubrificante seja maior, (4) o efeito da redução da área resistente aos esforços de contato, devido à presença dos nódulos de grafita, na resistência a fadiga foi evidenciado, porém o acabamento superficial mostrou-se mais relevante do que a distribuição e tamanho dos nódulos