The present study tested the hypothesis that zebrafish (Danio rerio) aquaporin-1a1 (AQP1a1) serves as a multi-functional channel for the transfer of the small gaseous molecules, CO2 and ammonia, as well as water, across biological membranes. Zebrafish embryos were microinjected with a translation-blocking morpholino oligonucleotide targeted to AQP1a1. Knockdown of AQP1a1 significantly reduced r...

Ammonia has been shown to function as a morphogen at multiple steps during the development of the cellular slime mold Dictyostelium discoideum; however, it is largely unknown how intracellular ammonia levels are controlled. In the Dictyostelium genome, there are five genes that encode putative ammonium transporters: amtA, amtB, amtC, rhgA, and rhgB. Here, we show that AmtA regulates ammonia hom...

Molecular approaches have revealed considerable diversity and uncultured novelty in natural prokaryotic populations, but not direct links between the new genotypes detected and ecosystem processes. Here we describe the influence of the structure of communities of ammonia-oxidizing bacteria on nitrogen cycling in microcosms containing natural and managed grasslands and amended with artificial sh...

The x-ray crystal structure of the heterodimeric carbamoyl phosphate synthetase from Escherichia coli has identified an intermolecular tunnel that connects the glutamine binding site within the small amidotransferase subunit to the two phosphorylation sites within the large synthetase subunit. The tunneling of the ammonia intermediate through the interior of the protein has been proposed as a m...

The effects of exposure of animals to ammonia on their delayed type of dermal response, the mitogenic and antigenic responses of their lymphocytes, and the bactericidal and phagocytic activities of their alveolar macrophages were examined. Experimental guinea pigs vaccinated with Mycobacterium bovis BCG were exposed to 3.75 micrograms of ammonia per dl of air (50 ppm) or 6.75 micrograms of ammo...

Dairy barns are thought to emit large amounts of ammonia, which can have detrimental effects on human health and natural ecosystems. In the U.S., relatively little is known about the processes that affect the rate and magnitude of ammonia emissions from dairy barns. The end of a conventional tie-stall dairy barn was remodeled into four chambers (four animals per chamber) to initially evaluate d...

ammonia (nh3) and nitrite (no2) toxic chemicals which resulted from fish culture, especially in intensive fish culture systems. to evaluate the efficiency of green algae scenedesmus quadricauda in ammonia and nitrite removal from intensive fish farm effluent and also its application as suitable culture medium for s. quadricauda , effluent water samples were collected from rainbow trout farm. si...

ammonia in air can be hazardous to human and animal life and should be removed from the environment. recently the removal of environmental pollutants such as ammonia by means of natural and modified zeolites has attracted a lot of attention and interests. in this study the capability of three iranian natural zeolites (clinoptilolite) in point of view of removal of ammonia from air was investiga...

BAJWA, KANWARDEEP SINGH. Measurements and Modeling of Emissions, Dispersion and Dry Deposition of Ammonia from Swine Facilities. (Under the direction of Dr. Viney P. Aneja and Dr. S. Pal Arya). Ammonia has recently gained importance for its increasing atmospheric concentrations and its role in the formation of aerosols. Studies have shown increasing atmospheric concentration levels of NH3 and N...

There is much information about the concentrations and emissions of ammonia in livestock production facilities in Europe and North America; examples of best and worst practice have been identified in terms of building design and environmental management. Numerically, cattle are the largest source of ammonia emissions, while the ammonia concentration in swine and poultry buildings is much higher...