query: human interaction with the nitrogen cycle is primarily due to

pos: Human impact on the nitrogen cycle Human impact on the nitrogen cycle Human impact on the nitrogen cycle is diverse. Agricultural and industrial nitrogen (N) inputs to the environment currently exceed inputs from natural N fixation. As a consequence of anthropogenic inputs, the global nitrogen cycle (Fig. 1) has been significantly altered over the past century. Global atmospheric nitrous oxide (NO) mole fractions have increased from a pre-industrial value of ~270 nmol/mol to ~319 nmol/mol in 2005. Human activities account for over one-third of NO emissions, most of which are due to the agricultural sector. This article is intended to give a brief review of the

pos: Human impact on the nitrogen cycle Human impact on the nitrogen cycle Human impact on the nitrogen cycle is diverse. Agricultural and industrial nitrogen (N) inputs to the environment currently exceed inputs from natural N fixation. As a consequence of anthropogenic inputs, the global nitrogen cycle (Fig. 1) has been significantly altered over the past century. Global atmospheric nitrous oxide (NO) mole fractions have increased from a pre-industrial value of ~270 nmol/mol to ~319 nmol/mol in 2005. Human activities account for over one-third of NO emissions, most of which are due to the agricultural sector. This article is intended to give a brief review of the

neg: Human impact on the nitrogen cycle control the N cascade, there must be integration of scientific disciplines and further work on Nr storage and denitrification rates. Human impact on the nitrogen cycle Human impact on the nitrogen cycle is diverse. Agricultural and industrial nitrogen (N) inputs to the environment currently exceed inputs from natural N fixation. As a consequence of anthropogenic inputs, the global nitrogen cycle (Fig. 1) has been significantly altered over the past century. Global atmospheric nitrous oxide (NO) mole fractions have increased from a pre-industrial value of ~270 nmol/mol to ~319 nmol/mol in 2005. Human activities account for over one-third of NO emissions,

neg: Institute for Earth System Preservation considered sum of the planet´s interacting physical, chemical, biotic and societal processes. The atmosphere, hydrosphere, and cryosphere are parts of the earth system as well as the grand natural cycles (carbon cycle, nitrogen cycle, phosphorus cycle and sulfur cycle) including the water cycle. All living organisms, including humans and their activities, are an integral part of the earth system. The growing human population, however, seriously challenges the interaction of the system´s components and dynamics. Advancing solutions to maintain the resilience of the grand living conditions on planet Earth is the main interest of IESP's members. Therefore, IESP organizes interdisciplinary, discussion-based

neg: Mycorrhizal network Mycorrhizal network Mycorrhizal networks (also known as common mycorrhizal networks or CMN) are underground hyphal networks created by mycorrhizal fungi that connect individual plants together and transfer water, carbon, nitrogen, and other nutrients and minerals. The formation of these networks is context dependent, and can be influenced by factors such as soil fertility, resource availability, host or myco-symbiont genotype, disturbance and seasonal variation. due to enrichment of nitrogen in soil affect michozial communities or effect of human activities of human affecting nitrogen cycle. By analogy to the many roles intermediated by the World Wide Web in human communities, the many

neg: Nitrogen diatomic gas with the formula N. Dinitrogen forms about 78% of Earth's atmosphere, making it the most abundant uncombined element. Nitrogen occurs in all organisms, primarily in amino acids (and thus proteins), in the nucleic acids (DNA and RNA) and in the energy transfer molecule adenosine triphosphate. The human body contains about 3% nitrogen by mass, the fourth most abundant element in the body after oxygen, carbon, and hydrogen. The nitrogen cycle describes movement of the element from the air, into the biosphere and organic compounds, then back into the atmosphere. Many industrially important compounds, such as ammonia, nitric acid,

neg: Soil food web flowed from lower resources to higher trophic levels through three main channels. The bacterial and fungal channels had the largest energy flow, while the herbivory channel, in which organisms directly consumed plant roots, was smaller. It is now widely recognized that bacteria and fungi are critical to the decomposition of carbon and nitrogen and play important roles in both the carbon cycle and nitrogen cycle. An interaction web, shown above right, is similar to a topological web, but instead of showing the movement of energy or materials, the arrows show how one group influences another. In interaction food web models,

neg: Human impact on the nitrogen cycle progress has been made in determining the relative importance of Nr accumulation and denitrification, which has been mainly due to a lack of integration among scientific disciplines. Most Nr applied to global agroecosystems cascades through the atmosphere and aquatic and terrestrial ecosystems until it is converted to N, primarily through denitrification. Although terrestrial denitrification produces gaseous intermediates (nitric oxide [NO] and nitrous oxide [NO]), the last step—microbial production of N— is critical because atmospheric N is a sink for Nr. Many studies have clearly demonstrated that managed buffer strips and wetlands can remove significant amounts of nitrate (NO) from agricultural

neg: Lichens and nitrogen cycling population. While costly, in regions where nitrogen availability is low, fixation process is the main way for the lichen to absorb nitrogen which is macronutrient (essential nutrient). Nitrogen, as a macronutrient and a biogeochemical cycle, also affects the ecology. Through the nitrogen cycle, it breaks down into the chemical form that allows plants to absorb as nutrients. There are certain regions in the world that most plants can not live due to harsh environments as well as lack of nutrients such as nitrogen. That means that at in some regions, the biogeochemical cycle (including nitrogen cycle and carbon cycle) is

neg: Nitrogen cycle nitrogen availability can affect the rate of key ecosystem processes, including primary production and decomposition. Human activities such as fossil fuel combustion, use of artificial nitrogen fertilizers, and release of nitrogen in wastewater have dramatically altered the global nitrogen cycle. Nitrogen is present in the environment in a wide variety of chemical forms including organic nitrogen, ammonium (NH), nitrite (NO), nitrate (NO), nitrous oxide, (NO), nitric oxide (NO) or inorganic nitrogen gas (N). Organic nitrogen may be in the form of a living organism, humus or in the intermediate products of organic matter decomposition. The processes in the nitrogen cycle

neg: Human impact on the nitrogen cycle During this time, the human population more than tripled, partly due to increased food production. Since the industrial revolution, an additional source of anthropogenic N input has been fossil fuel combustion, which is used to generate energy (e.g., to power automobiles). During combustion of fossil fuels, high temperatures and pressures provide energy to produce NO from N oxidation. Additionally, when fossil fuel is extracted and burned, fossil N may become reactive (i.e., NO emissions). During the 1970s, scientists began to recognize that N inputs were accumulating in the environment and affecting ecosystems. Between 1600 and 1990, global reactive nitrogen (Nr)

neg: Microbial ecology In such zones, chemosynthetic microbes provide energy and carbon to the other organisms. Other microbes are decomposers, with the ability to recycle nutrients from other organisms' waste products. These microbes play a vital role in biogeochemical cycles. The nitrogen cycle, the phosphorus cycle, the sulphur cycle and the carbon cycle all depend on microorganisms in one way or another. For example, the nitrogen gas which makes up 78% of the earth's atmosphere is unavailable to most organisms, until it is converted to a biologically available form by the microbial process of nitrogen fixation. Due to the high level of horizontal

neg: Human impact on the nitrogen cycle systems through denitrification. Such management may help attenuate the undesirable cascading effects and eliminate environmental Nr accumulation. Human activities dominate the global and most regional N cycles. N inputs have shown negative consequences for both nutrient cycling and native species diversity in terrestrial and aquatic systems. In fact, due to long-term impacts on food webs, Nr inputs are widely considered the most critical pollution problem in marine systems. In both terrestrial and aquatic ecosystems, responses to N enrichment vary; however, a general re-occurring theme is the importance of thresholds (e.g., nitrogen saturation) in system nutrient retention capacity. In order to

neg: Human impact on the nitrogen cycle competitive exclusion of these superior colonizers/poor competitors. Aquatic ecosystems also exhibit varied responses to nitrogen enrichment. NO loading from N saturated, terrestrial ecosystems can lead to acidification of downstream freshwater systems and eutrophication of downstream marine systems. Freshwater acidification can cause aluminium toxicity and mortality of pH-sensitive fish species. Because marine systems are generally nitrogen-limited, excessive N inputs can result in water quality degradation due to toxic algal blooms, oxygen deficiency, habitat loss, decreases in biodiversity, and fishery losses. Atmospheric N deposition in terrestrial landscapes can be transformed through soil microbial processes to biologically available nitrogen, which can result in

neg: Nitrogen cycle result of extensive cultivation of legumes (particularly soy, alfalfa, and clover), growing use of the Haber–Bosch process in the creation of chemical fertilizers, and pollution emitted by vehicles and industrial plants, human beings have more than doubled the annual transfer of nitrogen into biologically available forms. In addition, humans have significantly contributed to the transfer of nitrogen trace gases from Earth to the atmosphere and from the land to aquatic systems. Human alterations to the global nitrogen cycle are most intense in developed countries and in Asia, where vehicle emissions and industrial agriculture are highest. Nitrous oxide (NO) has risen

neg: Role of Calmodulins tube for elongation during the process of fertilization. Similarly, CaM is also essential at the pollen tube apex it's primarily role here involves guidance of the pollen tube growth. 1) Nodule formation: Ca plays a significantly important role in nodule formation in legumes. Nitrogen is an essential element required in plants and many legumes, unable to fix nitrogen independently, pair symbiotically with nitrogen-fixing bacteria that reduce nitrogen to ammonia. This legume-"rhizobia" interaction establishment requires the Nod factor that is produced by the "rhizobium" bacteria. The Nod factor is recognized by the root hair cells that are involved in the nodule

neg: Water cycle erosion and transport of dissolved salts from the land. Cultural eutrophication of lakes is primarily due to phosphorus, applied in excess to agricultural fields in fertilizers, and then transported overland and down rivers. Both runoff and groundwater flow play significant roles in transporting nitrogen from the land to waterbodies. The dead zone at the outlet of the Mississippi River is a consequence of nitrates from fertilizer being carried off agricultural fields and funnelled down the river system to the Gulf of Mexico. Runoff also plays a part in the carbon cycle, again through the transport of eroded rock and soil.

neg: Nitrogen generator functioning as a spool with specifically reeled polymer fibers. Gas flow is supplied under pressure into a bundle of membrane fibers. Due to the difference in partial pressures on the external and internal membrane surface gas flow separation is accomplished. Nitrogen generator Nitrogen generators and stations are stationary or mobile air-to-nitrogen production complexes. The adsorption gas separation process in nitrogen generators is based on the phenomenon of fixing various gas mixture components by a solid substance called an adsorbent. This phenomenon is brought about by the gas and adsorbent molecules' interaction. The technology of air-to-nitrogen production with the use of

neg: Air–fuel ratio the formation of nitrogen oxides. Some engines are designed with features to allow lean-burn. For precise air-fuel ratio calculations, the oxygen content of combustion air should be specified because of different air density due to different altitude or intake air temperature, possible dilution by ambient water vapor, or enrichment by oxygen additions. In theory a stoichiometric mixture has just enough air to completely burn the available fuel. In practice this is never quite achieved, due primarily to the very short time available in an internal combustion engine for each combustion cycle. Most of the combustion process is completed in approximately

neg:
Steady-state economy times. Widespread overuse of groundwater results in water deficits in many countries. By 2025, water scarcity could impact the living conditions of two-thirds of the world's population.

 The destructive impact of human activity on wildlife habitats worldwide is accelerating the extinction of rare species, thereby substantially reducing earth's biodiversity. The natural nitrogen cycle is heavily overloaded by industrial nitrogen fixation and use, thereby disrupting most known types of ecosystems. The accumulating plastic debris in the oceans decimates aquatic life. Ocean acidification due to the excess concentration of carbon dioxide in the atmosphere is resulting in coral bleaching and impedes

neg: Human impact on the nitrogen cycle microbial nitrification and denitrification are "leaky", N deposition is expected to increase trace gas emissions. Additionally, with increasing NH accumulation in the soil, nitrification processes release hydrogen ions, which acidify the soil. NO, the product of nitrification, is highly mobile and can be leached from the soil, along with positively charged alkaline minerals such as calcium and magnesium. In acid soils, mobilized aluminium ions can reach toxic concentrations, negatively affecting both terrestrial and adjacent aquatic ecosystems. Anthropogenic sources of N generally reach upland forests through deposition. A potential concern of increased N deposition due to human activities is altered nutrient

neg: Liquid nitrogen object into a slush of liquid and solid nitrogen rather than liquid nitrogen alone. Liquid nitrogen is a compact and readily transported source of dry nitrogen gas, as it does not require pressurization. Further, its ability to maintain temperatures far below the freezing point of water makes it extremely useful in a wide range of applications, primarily as an open-cycle refrigerant, including: The culinary use of liquid nitrogen is mentioned in an 1890 recipe book titled "Fancy Ices" authored by Mrs. Agnes Marshall, but has been employed in more recent times by restaurants in the preparation of frozen desserts, such

neg: HSP90AB1 to the HNGC (HUGO gene nomenclature committee): Chaperonins are characterized by their barrel-shaped structure with binding sites for client proteins inside the barrels. Human HSP90 proteins are classified into 5 major groups according to the HNGC: Whereas HSP90AA1 and HSP90AB1 are located primarily in the cytoplasm of the cells, HSP90B1 can be found in the endoplasmic reticulum and Trap1 in mitochondria. Co-chaperones bind to HSPs and influence their activity, substrate (client) specificity and interaction with other HSPs. For example, the co-chaperone CDC37 (cell division cycle 37) stabilizes the cell cycle regulatory proteins CDK4 (cyclin dependent kinase 4) and Cdk6. Hop

neg: RHOA to GTP (conducted simultaneously via guanine nucleotide exchange factors and GTPase activating factor). RhoA is activated primarily by guanine nucleotide exchange factors (GEFs) via phosphorylation; due to large network of overlapping phosphorylation, a multitude of GEFs are utilized to enable specific signaling pathways. These structural arrangements provide interaction sites that can interact with effectors and guanine factors in order to stabilize and signal the hydrolysis of GTP. RhoA is primarily involved in these activities: actin organization, myosin contractility, cell cycle maintenance, cellular morphological polarization, cellular development and transcriptional control. RhoA is prevalent in regulating cell shape, polarity and locomotion via

neg: Nitrogen cycle Nitrogen cycle The nitrogen cycle is the biogeochemical cycle by which nitrogen is converted into multiple chemical forms as it circulates among atmosphere, terrestrial, and marine ecosystems. The conversion of nitrogen can be carried out through both biological and physical processes. Important processes in the nitrogen cycle include fixation, ammonification, nitrification, and denitrification. The majority of Earth's atmosphere (78%) is atmosphere nitrogen, making it the largest source of nitrogen. However, atmospheric nitrogen has limited availability for biological use, leading to a scarcity of usable nitrogen in many types of ecosystems. The nitrogen cycle is of particular interest to ecologists because

neg: Human action cycle Human action cycle The human action cycle is a psychological model which describes the steps humans take when they interact with computer systems. The model was proposed by Donald A. Norman, a scholar in the discipline of human–computer interaction. The model can be used to help evaluate the efficiency of a user interface (UI). Understanding the cycle requires an understanding of the user interface design principles of affordance, feedback, visibility and tolerance. The human action cycle describes how humans may form goals and then develop a series of steps required to achieve that goal, using the computer system. The user

neg: Planetary boundaries science and tools to value and account for natural capital, in biophysical, economic and other terms [...] Two: compelling demonstrations of such tools in resource policy. Three: cooperation among governments, development organizations, corporations and communities to help nations build more durable economies while also maintaining critical ecosystem services." Since the industrial revolution, the Earth's nitrogen cycle has been disturbed even more than the carbon cycle. "Human activities now convert more nitrogen from the atmosphere into reactive forms than all of the Earth´s terrestrial processes combined. Much of this new reactive nitrogen pollutes waterways and coastal zones, is emitted back to

neg: Nitrogen cycle nitrogen conversion in the oceans. The balanced formula for this "anammox" chemical reaction is: NH + NO → N + 2HO (Δ"G"° = ). Though nitrogen fixation is the primary source of plant-available nitrogen in most ecosystems, in areas with nitrogen-rich bedrock, the breakdown of this rock also serves as a nitrogen source. The nitrogen cycle is an important process in the ocean as well. While the overall cycle is similar, there are different players and modes of transfer for nitrogen in the ocean. Nitrogen enters the water through the precipitation, runoff, or as N from the atmosphere. Nitrogen cannot

neg: Nitrogen cycle ammonium - two reduced forms of nitrogen - can be detrimental over time due to an increased toxicity toward sensitive species of plants, particularly those that are accustomed to using nitrate as their source of nitrogen, causing poor development of their roots and shoots. Increased nitrogen deposition also leads to soil acidification, which increases base cation leaching in the soil and amounts of aluminium and other potentially toxic metals, along with decreasing the amount of nitrification occurring and increasing plant-derived litter. Due to the ongoing changes caused by high nitrogen deposition, an environment's susceptibility to ecological stress and disturbance -

neg: Human impact on the nitrogen cycle livestock operations are transported to downwind ecosystems, influencing N cycling and nutrient losses. Six major effects of NO and NH emissions have been cited: 1) decreased atmospheric visibility due to ammonium aerosols (fine particulate matter [PM]); 2) elevated ozone concentrations; 3) ozone and PM affects human health (e.g. respiratory diseases, cancer); 4) increases in radiative forcing and global climate change; 5) decreased agricultural productivity due to ozone deposition; and 6) ecosystem acidification and eutrophication. Terrestrial and aquatic ecosystems receive Nr inputs from the atmosphere through wet and dry deposition. Atmospheric Nr species can be deposited to ecosystems in precipitation (e.g.,

neg: Nitrogen cycle of ammonium to nitrate is performed primarily by soil-living bacteria and other nitrifying bacteria. In the primary stage of nitrification, the oxidation of ammonium (NH) is performed by bacteria such as the "Nitrosomonas" species, which converts ammonia to nitrites (). Other bacterial species such as "Nitrobacter", are responsible for the oxidation of the nitrites () into nitrates (). It is important for the ammonia () to be converted to nitrates or nitrites because ammonia gas is toxic to plants. Due to their very high solubility and because soils are highly unable to retain anions, nitrates can enter groundwater. Elevated nitrate

neg: Phenylacetylglutamine Phenylacetylglutamine Phenylacetylglutamine is a product formed by the conjugation of phenylacetate and glutamine. It is a common metabolite that is naturally occurring in human urine. The highly-nitrogenous compound most commonly encountered in the human subjects with urea cycle disorders, associated with uremic conditions in the body. These conditions, such as uremia or hyperammonemia, tend to cause high levels of nitrogen in the form of ammonia in the blood. Uremic conditions are a result of defects in enzymes that convert ammonia to urea, the primary nitrogenous waste metabolite in the urea cycle. Phenylacetylglutamine is the primary metabolite of the degradation of

neg: Blood urea nitrogen Blood urea nitrogen Blood urea nitrogen (BUN) is a medical test that measures the amount of urea nitrogen found in blood. The liver produces urea in the urea cycle as a waste product of the digestion of protein. Normal human adult blood should contain between 6 and 20 mg of urea nitrogen per 100 ml (6–20 mg/dL) of blood. Individual laboratories will have different reference ranges as the assay used can vary between laboratories. BUN is an indication of renal (kidney) health. The normal range is 1.8–7.1 mmol/L or 6–20 mg/dL. The main causes of an increase in BUN are:

neg: Blood urea nitrogen mmol (1 mole N = 2 moles N per mole of urea): Blood urea nitrogen Blood urea nitrogen (BUN) is a medical test that measures the amount of urea nitrogen found in blood. The liver produces urea in the urea cycle as a waste product of the digestion of protein. Normal human adult blood should contain between 6 and 20 mg of urea nitrogen per 100 ml (6–20 mg/dL) of blood. Individual laboratories will have different reference ranges as the assay used can vary between laboratories. BUN is an indication of renal (kidney) health. The normal range is 1.8–7.1 mmol/L

neg: Fishkeeping often addressed through filtration. Activated carbon filters absorb nitrogen compounds and other toxins from the water. Biological filters provide a medium specially designed for colonization by the desired nitrifying bacteria. Activated carbon and other substances, such as ammonia absorbing resins, stop working when their pores fill, so these components have to be replaced with fresh stocks periodically. New aquaria often have problems associated with the nitrogen cycle due to insufficient beneficial bacteria, which is known as "New Tank Syndrome". Therefore, new tanks have to mature before stocking them with fish. There are three basic approaches to this: the "fishless cycle",

neg: Human impact on the nitrogen cycle surface-water acidification, and loss of biodiversity. NO and NH inputs from terrestrial systems and the atmosphere can acidify freshwater systems when there is little buffering capacity due to soil acidification. N pollution in Europe, the Northeastern United States, and Asia is a current concern for freshwater acidification. Lake acidification studies in the Experimental Lake Area (ELA) in northwestern Ontario clearly demonstrated the negative effects of increased acidity on a native fish species: lake trout (Salvelinus namaycush) recruitment and growth dramatically decreased due to extirpation of its key prey species during acidification. Urbanization, deforestation, and agricultural activities largely contribute sediment and

neg: PURA The Pur-alpha inhibition of cancer cell proliferation occurs at specific points in the cell division cycle, primarily at checkpoints for transition to DNA replication or mitosis. These cell cycle effects are consistent with an interaction between Pur-alpha and CDK, cell cycle-dependent protein kinases. They are also consistent with documented interaction between Pur-alpha and the tumor suppressor protein, Rb. Studies of genetic inactivation of "PURA" in the mouse provided evidence leading to that for "PURA" gene disorders in brain disease. Homozygous "PURA" knockouts die shortly after birth with severe defects in brain layer development, tissue wasting and movement disorders. Defects in

neg: Lichens and nitrogen cycling heaths. Lichens and nitrogen cycling The nitrogen cycle is one of the Earth’s biogeochemical cycle that involves the conversion of nitrogen into different chemical forms. The main processes of the nitrogen cycle are the fixation, ammonification, nitrification, and denitrification. As one of the macronutrients, nitrogen plays an important role in plant growth. Both nitrogen-fixing lichens and non-nitrogen fixing lichens absorb the nitrogen as the one of the nutrient. Different environments have different factors that contributes or affect the nitrogen cycle. For example, in the subarctic heath, increase in temperature can cause N2 fixation to increase or decrease based on season

neg: Lichens and nitrogen cycling Lichens and nitrogen cycling The nitrogen cycle is one of the Earth’s biogeochemical cycle that involves the conversion of nitrogen into different chemical forms. The main processes of the nitrogen cycle are the fixation, ammonification, nitrification, and denitrification. As one of the macronutrients, nitrogen plays an important role in plant growth. Both nitrogen-fixing lichens and non-nitrogen fixing lichens absorb the nitrogen as the one of the nutrient. Different environments have different factors that contributes or affect the nitrogen cycle. For example, in the subarctic heath, increase in temperature can cause N2 fixation to increase or decrease based on season while

neg: Sex effects of water pollution the global nitrogen cycle which affects ocean climate, the Haber-Bosch process, is used for an agricultural fertilizer. There are also humans. The chemicals that alter gender are constantly produced and excreted by a human being on a normal everyday basis. Along with this, pregnant women contain greater amounts of the chemicals thus releasing greater amounts of it with every excretion. Because of this, one can see that the source of gender-altering pollutants is not natural, but due to man-made chemicals that, globally, are being released. Chemicals such as EDC's and artificial estrogens are in constant circulation around the planet through

neg: Demitarian diet, are not opposed to eating meat occasionally but do not have the same unifying environmental reasons for reduction in consumption as Demitarians. As the human population increases and more of the world develops, consumption of animal products increases and the associated nitrogen pollution poses substantial threats to the environment. Nitrogen has been used in synthetic fertilizers since the 1900s causing significant alterations to the global nitrogen cycle. Since then, humans have more than doubled the amount of Nitrogen in the biosphere, releasing more Nitrogen than all other natural processes combined. This overabundance of Nitrogen flows freely through the globe

neg: Korean natural farming of plant secretions. Mold constitutes 70-75%, bacteria 20-25% and small animals the rest. The microorganisms contain approximately 70 kg of carbon and 11 kg of nitrogen, similar to the amount of nitrogen typically applied as fertilizer. Nutrients are taken up and deposited in a natural cycle unless disrupted by human intervention. As plants decay,"detrital" nitrogen and phosphorus is returned to the soil. Soil fungus and bacteria absorb these nutrients. The fungus and bacteria are consumed by fungal and bacterial-feeding namatodes, respectively. These nematodes are in turn consumed by omnivorous predatory nematodes. At each stage, some inorganic nitrogen and phosphorus is

neg: Crystallographic defects in diamond a result of thermal degradation of platelets. Contrary to platelets, voidites do contain much nitrogen, in the molecular form. Extrinsic and intrinsic defects can interact producing new defect complexes. Such interaction usually occurs if a diamond containing extrinsic defects (impurities) is either plastically deformed or is irradiated and annealed. Most important is the interaction of vacancies and interstitials with nitrogen. Carbon interstitials react with substitutional nitrogen producing a bond-centered nitrogen interstitial showing strong IR absorption at 1450 cm. Vacancies are efficiently trapped by the A, B and C nitrogen centers. The trapping rate is the highest for the C centers,

neg: Hydrothermal vent microbial communities to provide some of the biologically available nitrogen to the nitrogen cycle especially at unsedimented hydrothermal vents. Nitrogen fixation is done by many different microbes including methanogen in the orders "Methanomicrobiales", "Methanococcales", and "Methanobacteriales""." Thermophilic microbes have been found to be able to fix nitrogen at higher temperatures such as 92°C. Nitrogen fixation may be especially prevalent in microbial mats and particulate material where biologically available levels of nitrogen are low, due to high microbe density and anaerobic environment allows the function of nitrogenase, a nitrogen fixing enzyme. Evidence have also been detected of assimilation, nitrification, denitrification, anamox, mineralization and

neg: Leighton relationship Leighton relationship In atmospheric chemistry, the Leighton relationship is an equation that determines the concentration of tropospheric ozone in areas polluted by the presence of nitrogen oxides. Ozone in the troposphere is primarily produced through the photolysis of nitrogen dioxide by photons with wavelengths (λ) less than 420 nanometers, which are able to reach the lowest levels of the atmosphere, through the following mechanism: This series of reactions creates a null cycle, in which there is no net production or loss of any species involved. Since O (P) is very reactive and O is abundant, O (P) can be assumed

neg: Human impact on the nitrogen cycle harmful to other marine life as well as to humans. The above system responses to reactive nitrogen (Nr) inputs are almost all exclusively studied separately; however, research increasingly indicates that nitrogen loading problems are linked by multiple pathways transporting nutrients across system boundaries. This sequential transfer between ecosystems is termed the nitrogen cascade. (see illustration from United Nations Environment Programme). During the cascade, some systems accumulate Nr, which results in a time lag in the cascade and enhanced effects of Nr on the environment in which it accumulates. Ultimately, anthropogenic inputs of Nr are either accumulated or denitrified; however, little

neg: Soil organic matter and other nitrogen containing products, incorporating thus nitrogen and avoiding its mineralization. Other nutrients are also protected in this way from mineralization. There is a classification into three groups, based on solubility in acids and alkalis, and also related to stability. Soil plays a major role in the global carbon cycle, with the global soil carbon pool estimated at 2500 gigatons. This is 3.3 times the size of the atmospheric pool (750 gigatons) and 4.5 times the biotic pool (560 gigatons). The pool of organic carbon, which occurs primarily in the form of SOM, accounts roughly 1550 gigatons of the

neg: Archaea release of ~0.3 to 0.5 gigatons of carbon per year globally. Archaea recycle elements such as carbon, nitrogen and sulfur through their various habitats. Although these activities are vital for normal ecosystem function, archaea can also contribute to human-made changes, and even cause pollution. Archaea carry out many steps in the nitrogen cycle. This includes both reactions that remove nitrogen from ecosystems (such as nitrate-based respiration and denitrification) as well as processes that introduce nitrogen (such as nitrate assimilation and nitrogen fixation). Researchers recently discovered archaeal involvement in ammonia oxidation reactions. These reactions are particularly important in the oceans. The

neg: Aquarium ammonia absorbing resins, stop working when their pores fill, so these components have to be replaced regularly. New aquaria often have problems associated with the nitrogen cycle due to insufficient beneficial bacteria. Therefore, fresh water has to be matured before stocking them with fish. There are three basic approaches to this: the "fishless cycle", the "silent cycle" and "slow growth". In a fishless cycle, small amounts of ammonia are added to an unpopulated tank to feed the bacteria. During this process, ammonia, nitrite, and nitrate levels are tested to monitor progress. The "silent" cycle is basically nothing more than densely

neg: Madison Symmetric Torus the inability to achieve a perfect vacuum in a fusion reactor before fueling. Thus, materials such as water vapor, nitrogen, and carbon will be found in small amounts in typical plasma discharges. Impurities may also be generated during plasma discharges due to plasma-wall interactions. These interactions primarily cause material from the wall to be ejected into the plasma through sputtering. In the Madison Symmetric Torus (MST), properties of the impurity ions (e.g. carbon, oxygen, etc.) are closely linked to properties of the deuterium ions as a result of strong interaction between the ion species. Thus, impurity ion measurements can, in

neg: Human-Computer Interaction Institute and improves human capabilities by integrating aspects of computer science, design, social science, and learning science. HCII offers Human Computer Interaction (HCI) as an additional major for undergraduates, as well as a master's degree and PhDs in HCI. Students from various academic backgrounds come together from around the world to participate in this program. Students hold undergraduate degrees in psychology, design, and computer science, as well as many others. Students enter the program at various stages in their academic and professional careers. HCII research and educational programs span a full cycle of knowledge creation. The cycle includes research on how

neg: ISO 9241 and Part 11 (general guidance on the specification and measurement of usability). The revised multipart standard is numbered in series as follows: Within those series, the standard currently includes the following parts: In 2006, it revised ISO 9241-10:1996, Ergonomic requirements for office work with visual display terminals (VDTs) -- Part 10: Dialogue principles. This part deals with general ergonomic principles which apply to the design of dialogues between humans and information systems: ISO 9241-210, Ergonomics of human-system interaction, provides guidance on human-system interaction throughout the life cycle of interactive systems. With its introduction in 2008, it revised ISO 13407, Human-centred

neg: Nitrososphaera gargensis found to oxidize ammonia in this study, and with this knowledge, the researchers plan on coupling this ability with other processes in the nitrogen cycle in order to remove the form of nitrogen that is polluting the area. Such couplings could occur due to the fact that AOA are not affected by nitrous acid concentrations whereas nitrite-oxidizing bacteria are inhibited by this chemical. In this difference, techniques could be developed to foster deammonification, which is more cost-effective. Overall, in these studies, researchers are trying to find the correct balance in a thermophilic bioreactor in order to eliminate nitrogen. Nitrososphaera gargensis

neg: History of ecology was metaphorical and thus included environmental selection, were given less emphasis in the Origin than competition. Despite most portrayals of Darwin conveying him as a non-aggressive recluse who let others fight his battles, Darwin remained all his life a man nearly obsessed with the ideas of competition, struggle and conquest – with all forms of human contact as confrontation. By the 19th century, ecology blossomed due to new discoveries in chemistry by Lavoisier and de Saussure, notably the nitrogen cycle. After observing the fact that life developed only within strict limits of each compartment that makes up the atmosphere, hydrosphere,

neg: Human impact on the nitrogen cycle increase in soil nitrogen, as these fungi are unable to break down soil organic nitrogen. Two other studies found evidence that increased N availability has resulted in declines in species-diverse heathlands. Heathlands are characterized by N-poor soils, which exclude N-demanding grasses; however, with increasing N deposition and soil acidification, invading grasslands replace lowland heath. In a more recent experimental study of N fertilization and disturbance (i.e., tillage) in old field succession, it was found that species richness decreased with increasing N, regardless of disturbance level. Competition experiments showed that competitive dominants excluded competitively inferior species between disturbance events. With increased

neg: Human–computer interaction and development environments are relevant. On the human side, communication theory, graphic and industrial design disciplines, linguistics, social sciences, cognitive psychology, social psychology, and human factors such as computer user satisfaction are relevant. And, of course, engineering and design methods are relevant." Due to the multidisciplinary nature of HCI, people with different backgrounds contribute to its success. HCI is also sometimes termed "human–machine interaction" (HMI), "man-machine interaction" (MMI) or "computer-human interaction" (CHI). Poorly designed human-machine interfaces can lead to many unexpected problems. A classic example is the Three Mile Island accident, a nuclear meltdown accident, where investigations concluded that the

neg: Aquarium as "Nitrospira", it has recently been found that "Nitrobacter" are not present in detectable levels in established aquaria, while "Nitrospira" are plentiful.) However, commercial products sold as kits to "jump start" the nitrogen cycle often still contain "Nitrobacter". In addition to bacteria, aquatic plants also eliminate nitrogen waste by metabolizing ammonia and nitrate. When plants metabolize nitrogen compounds, they remove nitrogen from the water by using it to build biomass that decays more slowly than ammonia-driven plankton already dissolved in the water. What hobbyists call the nitrogen cycle is only a portion of the complete cycle: nitrogen must be added

neg: Fishkeeping well as the breakdown of mulm. While very small amounts of rotting foliage may be allowed to decompose and cycle nitrogen back into a planted aquarium, in practice aquarists will prune and remove substantial amounts of plant litter. Although called the nitrogen "cycle" by hobbyists, in aquaria the cycle is not complete: nitrogen must be added (usually indirectly through food) and nitrates must be removed at the end. Nitrogen bound up in plant matter is removed when the plant grows too large. Hobbyist aquaria typically do not have the requisite bacteria needed to detoxify nitrogen waste. This problem is most

neg: Kartik Chandran Kartik Chandran Kartik Chandran is an American environmental engineer at Columbia University, where he is a Professor in the Department of Earth and Environmental Engineering. He primarily works on the interface between environmental molecular and microbiology, environmental biotechnology and environmental engineering. The focus of his research is on elucidating the molecular microbial ecology and metabolic pathways of the microbial nitrogen cycle. Applications of his work have ranged from energy and resource efficient treatment of nitrogen containing wastewater streams, development and implementation of sustainable approaches to sanitation to novel models for resource recovery. Under his stewardship, the directions of biological wastewater

neg: Human impact on the nitrogen cycle Nr. Prior to industrial processes, the only sources of such energy were solar radiation and electrical discharges. Utilizing a large amount of metabolic energy and the enzyme nitrogenase, some bacteria and cyanobacteria convert atmospheric N to NH, a process known as biological nitrogen fixation (BNF). The anthropogenic analogue to BNF is the Haber-Bosch process, in which H is reacted with atmospheric N at high temperatures and pressures to produce NH. Lastly, N is converted to NO by energy from lightning, which is negligible in current temperate ecosystems, or by fossil fuel combustion. Until 1850, natural BNF, cultivation-induced BNF (e.g., planting

neg: Spongivore levels. Sponges also provide habitats for other organisms to live in, without them, these organisms would not have a protected habitat. Scientist have discovered that sponges play an important role in the nitrogen cycle. There are low amounts of nitrogen found in the water around coral reefs and most of the nitrogen that is found it bound into particulate or dissolved organic matter. Before this dissolved organic matter is able to be used by other reef organisms it must undergo a series of microbial transformations. The nitrogen cycle that occurs in sponges are able to cycle the nitrogen back into

neg: Nitrogen-15 tracing be a bias by changing natural nitrogen transformations. In agricultural soil, however, application of N enriched tracers, such as ammonium and nitrate, resembles conventional fertilisation practise. A way to calculate nitrogen transformation rates in soil can be achieved by numerical approximation that takes different, simultaneous nitrogen transformations into account. A numerical tool to study the nitrogen cycle is the N model based on a Markov chain Monte Carlo simulation. Nitrogen-15 tracing Nitrogen-15 (N) tracing is a technique to study the nitrogen cycle using the heavier, stable nitrogen isotope N. Despite the different weights, N is involved in the same chemical

neg: Human impact on the nitrogen cycle the Northeastern United States, hardwood stands receiving chronic N inputs have demonstrated greater capacity to retain N and increase annual net primary productivity (ANPP) than conifer stands. Once N input exceeds system demand, N may be lost via leaching and gas fluxes. When available N exceeds the ecosystem's (i.e., vegetation, soil, and microbes, etc.) uptake capacity, N saturation occurs and excess N is lost to surface waters, groundwater, and the atmosphere. N saturation can result in nutrient imbalances (e.g., loss of calcium due to nitrate leaching) and possible forest decline. A 15-year study of chronic N additions at the Harvard

neg: Silica cycle damming has lead to a reduction in silica supply to the ocean due to uptake by freshwater diatoms behind dams. The dominance of non-siliceous phytoplankton due to anthropogenic nitrogen and phosphorus loading and enhanced silica dissolution in warmer waters has the potential to limit silicon ocean sediment export in the future. The silica cycle plays an important role in long term global climate regulation. The global silica cycle also has large effects on the global carbon cycle through the Carbonate-Silicate Cycle. The process of silicate mineral weathering transfers atmospheric CO to the hydrologic cycle through the chemical reaction displayed above.

neg: University of Madeira Other Research Groups Undergraduate / 1st Bologna cycle Masters / 2nd Bologna cycle Postgraduate Doctoral / 3rd Bologna cycle University of Madeira The University of Madeira ("UMa" – , , is a Portuguese public university, created in 1988 in Funchal, Madeira. The university offers first, second cycle and Doctorate academic degrees in a wide range of fields, in accordance with the Bologna process. It is now under the CMU/Portugal agreement with Carnegie Mellon University, having master programme in Computer Engineering, Human Computer Interaction and Entertainment Technology. Students admitted will be eligible for scholarships and have internship opportunity during the summer

neg: Human trafficking in Texas is a large destination for many of these trafficked persons. These large transnational crime networks traffic primarily women and children, and cycle them through prostitution circuits with stops in large metropolitan areas around the country, usually only for several weeks at a time. Texas is an attractive stop for these circuits due to its sizable Asian population, which makes it easier for Asian trafficking victims to blend in. Texas sex trafficking operations involving Asian women and children typically operate out of massage parlors and hostess clubs, and are usually located in predominantly Asian areas with primarily Asian customer bases. Southeast

neg: Fasciolosis disease in the same capacity. Human infection is rare, even if the infection rate is high among animals. Especially high rates of human infection have been found in Bolivia, Peru and Egypt, and this may be due to consumption of certain foods. No vaccine is available to protect people against "Fasciola" infection. Preventative measures are primarily treating and immunization of the livestock, which are required to host the live cycle of the worms. Veterinary vaccines are in development, and their use is being considered by a number of countries on account of the risk to human health and economic losses

neg: Marilyn Fogel isotope ratios in prehistoric human bone collagen, Fogel was able to study the diet of ancient humans. North American humans were either primarily maize eaters, which is a C plant, or primarily hunter-gatherers, which contains more C plants. Using this knowledge, Fogel measured the 𝛿C values of essential amino acids to indicate whether the ancient human populations consumed primarily maize or were hunter-gatherers. Similarly, she was able to measure the marine nitrogen presence in human skeletons on Easter Island to establish that they consumed large amounts of marine food, and used the N enrichment in infants to determine the length

neg: Integrated gasification fuel cell cycle stream (needed for storage of carbon in greenhouse gas emissions control scenarios) is inefficient. In oxy-combustion, oxygen is extracted from air and used for fuel combustion, resulting in exhaust gases uncontaminated with nitrogen from which capture of a pure carbon dioxide stream is efficient. However, a large energy penalty for doing the air separation required for isolating the oxygen stream in the first place is incurred. In contrast, for SOFC function neither inefficient carbon capture from exhaust gases nor air separation is required: the only required interaction of the anode and cathode reactant streams is the transfer of oxygen from

neg: Nitrogen cycle is to transform nitrogen from one form to another. Many of those processes are carried out by microbes, either in their effort to harvest energy or to accumulate nitrogen in a form needed for their growth. For example, the nitrogenous wastes in animal urine are broken down by nitrifying bacteria in the soil to be used as new. The diagram {besides} alongside shows how these processes fit together to form the nitrogen cycle. The conversion of nitrogen gas (N) into nitrates and nitrites through atmospheric, industrial and biological processes is called nitrogen fixation. Atmospheric nitrogen must be processed, or "fixed",

neg: Biogeochemical cycle Biogeochemical cycle In ecology and Earth science, a biogeochemical cycle or substance turnover or cycling of substances is a pathway by which a chemical substance moves through biotic (biosphere) and abiotic (lithosphere, atmosphere, and hydrosphere) compartments of Earth. There are biogeochemical cycles for the chemical elements calcium, carbon, hydrogen, mercury, nitrogen, oxygen, phosphorus, selenium, and sulfur; molecular cycles for water and silica; macroscopic cycles such as the rock cycle; as well as human-induced cycles for synthetic compounds such as polychlorinated biphenyl (PCB). In some cycles there are "reservoirs" where a substance remains for a long period of time (such as

neg: Fishkeeping niche as Nitrospira, it has recently been found that "Nitrobacter" are not present in detectable levels in established aquaria, while "Nitrospira" is plentiful.) This process is known in the aquarium hobby as the nitrogen cycle. In a planted aquarium, aquatic plants also metabolize ammonium and nitrate as nutrients, removing them from the water column primarily through leaf surfaces. Plants remove some nutrients through their roots, either in or at the substrate level or via aerial roots floating in the water. Additional nitrogen and other nutrients are also made available for root uptake by decomposing organic matter in the substrate as

neg: Allam power cycle Allam power cycle The Allam power cycle or Allam cycle is a process for converting fossil fuels into mechanical power, while capturing the generated carbon dioxide and water. The main inventor behind the process is English engineer Rodney John Allam. A conventional combined cycle power station burns natural gas or gasified coal with air to drive a gas turbine and then uses the hot exhaust gas to heat water and drive a steam turbine. The working fluid for the gas turbine is carbon dioxide and water vapor from the combustion, along with nitrogen from the air (partially converted into nitrogen

neg: Demitarian Demitarian Demitarianism is the practice of making a conscious effort to reduce meat consumption largely for environmental reasons. The term was devised in October 2009 in Barsac, France at the combined workshop of Nitrogen in Europe (NinE) and Biodiversity in European Grasslands: Impacts of Nitrogen (BEGIN) where they developed “The Barsac Declaration: Environmental Sustainability and the Demitarian Diet”. The declaration was developed due to the implication of large scale animal farming as a primary contributor to disruptions in the nitrogen cycle and the subsequent effects on air, land, water, climate and biodiversity. Overconsumption of meat is also considered to contribute

neg: Human impact on the environment by 95%. Biodiesel reduced net emissions of carbon dioxide by 78.45%, compared with petroleum diesel. In urban buses, biodiesel reduced particulate emissions 32 percent, carbon monoxide emissions 35 percent, and emissions of sulfur oxides 8%, relative to life cycle emissions associated with use of petroleum diesel. Life cycle emissions of hydrocarbons were 35% higher and emission of various nitrogen oxides (NOx) were 13.5% higher with biodiesel. Life cycle analyses by the Argonne National Laboratory have indicated reduced fossil energy use and reduced greenhouse gas emissions with biodiesel, compared with petroleum diesel use. Biodiesel derived from various vegetable oils (e.g. canola

neg: Nitrogen generator Nitrogen generator Nitrogen generators and stations are stationary or mobile air-to-nitrogen production complexes. The adsorption gas separation process in nitrogen generators is based on the phenomenon of fixing various gas mixture components by a solid substance called an adsorbent. This phenomenon is brought about by the gas and adsorbent molecules' interaction. The technology of air-to-nitrogen production with the use of adsorption processes in nitrogen generators is well studied and widely applied at industrial facilities for the recovery of high-purity nitrogen. The operating principle of a nitrogen generator utilizing the adsorption technology is based upon the dependence of the adsorption rates

neg: Lake Superior other Great Lakes and so is less productive in terms of fish populations and is an oligotrophic lake. This is a result of the underdeveloped soils found in its relatively small watershed. However, nitrate concentrations in the lake have been continuously rising for more than a century. They are still much lower than levels considered dangerous to human health; but this steady, long-term rise is an unusual record of environmental nitrogen buildup. It may relate to anthropogenic alternations to the regional nitrogen cycle, but researchers are still unsure of the causes of this change to the lake's ecology. As for

neg: Atropa baetica "A. baetica" is a somewhat smaller plant, rarely exceeding 125 cm in height, while "A. belladonna" often reaches 150 cm with occasional very robust specimens reaching 200 cm. "Atropa baetica" grows among the undergrowth of mixed, upland forest on dry, sunny, rocky or stony slopes (and also, occasionally, in moister, shadier areas near watercourses) in limy (Calcium-rich) soils (often in disturbed, nitrogen-rich locations – see Nitrification and Human impact on the nitrogen cycle) at altitudes of 900–2,000 m. It is not, however, a quick coloniser of recently disturbed areas, preferring instead locations which have been disturbed at some time in

neg: Canaline the canaline-urea cycle (analogous to the ornithine-urea cycle) is formed. Every time a canavanine molecule runs through the canaline-urea cycle, the two terminal nitrogen atoms are released as urea. Urea is an important by-product of this reaction sequence because it makes ammonicial ammonia (urease-mediated) that is available to support intermediary nitrogen metabolism. -Canaline can be reductively cleaved to -homoserine, a non-protein amino acid of great importance in the formation of a host of essential amino acids. In this way, the third nitrogen atom of canavanine enters into the reactions of nitrogen metabolism of the plant. As homoserine, its carbon skeleton

neg: Vagina that the function of the penis simply is to impregnate, while female genitals can alter shape upon interaction with male organs, especially as to benefit or hinder reproductive success. Non-human primates are optimal models for human biomedical research because humans and non-human primates share physiological characteristics as a result of evolution. While menstruation is heavily associated with human females, and they have the most pronounced menstruation, it is also typical of ape relatives and monkeys. Female macaques menstruate, with a cycle length over the course of a lifetime that is comparable to that of female humans. Estrogens and progestogens in

neg: Urine earth's nitrogen cycle. In balanced ecosystems urine fertilizes the soil and thus helps plants to grow. Therefore, urine can be used as a fertilizer. Some animals use it to mark their territories. Historically, aged or fermented urine (known as lant) was also used for gunpowder production, household cleaning, tanning of leather and dyeing of textiles. Human urine and feces are collectively referred to as human waste or human excreta, and are managed with a sanitation system. Livestock urine and feces also require proper management if the livestock population density is high. Most animals have excretory systems for elimination of soluble

neg: Hydrothermal vent microbial communities species of dissolved inorganic nitrogen and can be produced by water mass mixing below hydrothermal vents and discharged in vent fluids. Quantities of available ammonium varies with each vent depending on the geological activity and microbial composition. Nitrate and nitrite concentrations are depleted in hydrothermal vents compared to the surrounding seawater. The study of the Nitrogen Cycle in hydrothermal vent microbial communities still requires more comprehensive research. However, isotope data suggests that microorganism influence dissolved inorganic nitrogen quantities and compositions and all pathways of the nitrogen cycle are likely to be found at hydrothermal vents. Biological nitrogen fixation is important

neg: Sustainable gardening natural economy there is the production and consumption of goods and services in the “human economy” which has now significantly altered, in a detrimental way, natural biogeochemical cycles (notable here are the water cycle, carbon cycle and nitrogen cycle so sustainable practices maximise support for ecosystem services. The use of native plants in a garden or landscape can both preserve and protect natural ecosystems, and reduce the amount of care and energy required to maintain a healthy garden or landscape. Native plants are adapted to the local climate and geology, and often require less maintenance than exotic species. Native plants

neg: Small tumor antigen and LTag interact through their J domains with Hsc70 to increase its ATPase activity. Because polyomavirus genome replication relies on the DNA replication machinery of the host cell, the cell must be in S phase (the part of the cell cycle in which the host cell's genome is normally replicated) in order to provide the necessary molecular machinery for viral DNA replication. Viral proteins therefore promote dysregulation of the cell cycle and entry into S phase. This function is usually primarily provided by LTag through its interactions with retinoblastoma protein and p53. STag contributes to this process through its interaction

neg: Human impact on the nitrogen cycle history of anthropogenic N inputs, and reported impacts of nitrogen inputs on selected terrestrial and aquatic ecosystems. Approximately 78% of earth's atmosphere is N gas (N), which is an inert compound and biologically unavailable to most organisms. In order to be utilized in most biological processes, N must be converted to reactive N (Nr), which includes inorganic reduced forms (NH and NH), inorganic oxidized forms (NO, NO, HNO, NO, and NO), and organic compounds (urea, amines, and proteins). N has a strong triple bond, and so a significant amount of energy (226 kcal mol) is required to convert N to

neg: Cahill cycle other purposes: This cycle is an important part of mammal physiology, but its presence and physiological significance in non-mammalian land vertebrates is unclear. For example although some fish use alanine as a nitrogen carrier, the cycle is unlikely to take place due to a slower glucose turnover rate and lower release of alanine from exercising muscle tissue. The Cahill cycle ultimately serves as a method of ridding the muscle tissue of the toxic ammonium ion, as well as indirectly providing glucose to energy-deprived muscle tissue. Under long periods of fasting, skeletal muscle can be degraded for use as an energy

neg: Fitts's law in space, the larger the D or the smaller the W, the more difficult it becomes to select the target. The task of selecting the temporal target is called temporal pointing. The model for temporal pointing was first presented to Human-computer Interaction field in 2016 . The model predicts the error rate, the human performance in temporal pointing, as a function of temporal index of difficulty (ID): formula_10 Fitts's law Fitts's law (often cited as Fitts' law) is a predictive model of human movement primarily used in human–computer interaction and ergonomics. This scientific law predicts that the time required to

neg: Human impact on the nitrogen cycle leading to changes in community composition. Several nutrient addition studies have shown that increased N inputs lead to dominance of fast-growing plant species, with associated declines in species richness. Fast growing species have a greater affinity for nitrogen uptake, and will crowd out slower growing plant species by blocking access to sunlight with their higher above ground biomass. Other studies have found that secondary responses of the system to N enrichment, including soil acidification and changes in mycorrhizal communities have allowed stress-tolerant species to out-compete sensitive species. Trees that have arbuscular mycorrhizal associations are more likely to benefit from an

neg: Human impact on the nitrogen cycle of leguminous crops), and incorporated organic matter were the only sources of N for agricultural production. Near the turn of the century, Nr from guano and sodium nitrate deposits was harvested and exported from the arid Pacific islands and South American deserts. By the late 1920s, early industrial processes, albeit inefficient, were commonly used to produce NH. Due to the efforts of Fritz Haber and Carl Bosch, the Haber-Bosch process became the largest source of nitrogenous fertilizer after the 1950s, and replaced BNF as the dominant source of NH production. From 1890 to 1990, anthropogenically created Nr increased almost ninefold.

neg: Anthropogenic metabolism economy sector in terms of corresponding productive land area. One of the major cycles that humans can contribute to that cause a major impact on climate change is the nitrogen cycle. This comes from nitrogen fertilizers that us humans are using. Gruber and Galloway have researched, "The massive acceleration of the nitrogen cycle caused by the production and industrial use of artificial nitrogen fertilizers worldwide has led to a range of environmental problems. Most important is how the availability of nitrogen will affect the capacity of Earth's biosphere to continue absorbing carbon from the atmosphere and to thereby continue helping

neg: Human impact on the nitrogen cycle fossil fuel and biomass combustion. In agroecosystems, fertilizer application has increased microbial nitrification (aerobic process in which microorganisms oxidize ammonium [NH] to nitrate [NO]) and denitrification (anaerobic process in which microorganisms reduce NO to atmospheric nitrogen gas [N]). Both processes naturally leak nitric oxide (NO) and nitrous oxide (NO) to the atmosphere. Of particular concern is NO, which has an average atmospheric lifetime of 114–120 years, and is 300 times more effective than CO as a greenhouse gas. NO produced by industrial processes, automobiles and agricultural fertilization and NH emitted from soils (i.e., as an additional byproduct of nitrification) and

neg: Methylomonas scandinavica vitro" with other Type I methanotrophs; values did not exceed 65%. "M. scandinavica" does not use multiple-carbon substrates as sources of carbon and energy. It uses the ribulose monophosphate pathway to incorporate methane and methanol into its biosynthetic metabolism. Following incorporation of the methane molecule, the organism uses an incomplete TCA cycle to generate reducing power for other portions of central metabolism. The TCA cycle is incomplete due to the inactivity of the α-ketoglutarate dehydrogenase enzyme. "M. scandinavica" also uses ammonia and nitrate as nitrogen sources. These precursor metabolites are incorporated via the glutamate cycle and reductive amination of pyruvate.

neg: Isotopes of nitrogen the nucleus a total magnetic spin of one. Like all elements heavier than lithium, the original source of nitrogen-14 and nitrogen-15 in the Universe is believed to be stellar nucleosynthesis, where they are produced as part of the carbon-nitrogen-oxygen cycle. Nitrogen-14 is the source of naturally-occurring, radioactive, carbon-14. Some kinds of cosmic radiation cause a nuclear reaction with nitrogen-14 in the upper atmosphere of the Earth, creating carbon-14, which decays back to nitrogen-14 with a half-life of 5,730±40 years. Nitrogen-15, is a rare stable isotope of nitrogen. Two sources of nitrogen-15 are the positron emission of oxygen-15 and the beta

neg: Novel ecosystem competitive and parasitic ways. Novel ecosystems "differ in composition and/or function from present and past systems". Novel ecosystems are the hallmark of the recently proposed anthropocene epoch. They have no natural analogs due to human alterations on global climate systems, invasive species, a global mass extinction, and disruption of the global nitrogen cycle. Novel ecosystems are creating many different kinds of dilemmas for conservation biologists. On a more local scale, abandoned lots, agricultural land, old buildings, field boundary stone walls or residential gardens provide study sites on the history and dynamics of ecology in novel ecosystems. Ellis (2008) identifies twenty-one

neg: Richard Latterell lead and arsenic, committed to stripping the polluted soil and encapsulating it in berms. Dr. Richard Lewis Latterell is a scientist in plant genetics. He completed his PhD study on the plant genus nicotina in 1958 at Cornell University. Dr. Latterell also studied the interaction of bees and red clover plant species utilization, while at the University of Pennsylvania. Later in his career was a pioneer exobiologist on the Mars Simulator II (MSII), which simulated both the day/night cycle and the nitrogen & carbon dioxide environment of Mars in the Tarrytown, NY laboratory. Over 250 different seed types were tested

neg: Human impact on the nitrogen cycle NO, NH, organic N compounds), as gases (e.g., NH and gaseous nitric acid [HNO]), or as aerosols (e.g., ammonium nitrate [NHNO]). Aquatic ecosystems receive additional nitrogen from surface runoff and riverine inputs. Increased N deposition can acidify soils, streams, and lakes and alter forest and grassland productivity. In grassland ecosystems, N inputs have produced initial increases in productivity followed by declines as critical thresholds are exceeded. Nitrogen effects on biodiversity, carbon cycling, and changes in species composition have also been demonstrated. In highly developed areas of near shore coastal ocean and estuarine systems, rivers deliver direct (e.g., surface runoff) and

neg: Hyperfine structure a dipole, both given above, we have The nuclear magnetic moments in a molecule exist in a magnetic field due to the angular momentum, T (R is the internuclear displacement vector), associated with the bulk rotation of the molecule, thus A typical simple example of the hyperfine structure due to the interactions discussed above is in the rotational transitions of hydrogen cyanide (HCN) in its ground vibrational state. Here, the electric quadrupole interaction is due to the N-nucleus, the hyperfine nuclear spin-spin splitting is from the magnetic coupling between nitrogen, N (I=1), and hydrogen, H (I=1/2), and a hydrogen spin-rotation

neg: Alternaria solani due to "A. solani" is highest when potato plants are injured, under stress or lack proper nutrition. High levels of nitrogen, moderate potassium and low phosphorus in the soil can reduce susceptibility of infection by the pathogen. "Alternaria solani" is a deuteromycete with a polycyclic life cycle. "Alternaria solani" reproduces asexually by means of conidia. "A.solani" is generally considered to be a necrotrophic pathogen, i.e. it kills the host tissue using cell wall degrading enzymes and toxins and feeds on the dead plant cell material The life cycle starts with the fungus overwintering in crop residues or wild members of

neg: Nitrogen dioxide the colorless dinitrogen tetroxide () below . The bond length between the nitrogen atom and the oxygen atom is 119.7 pm. This bond length is consistent with a bond order between one and two. Unlike ozone, O, the ground electronic state of nitrogen dioxide is a doublet state, since nitrogen has one unpaired electron, which decreases the alpha effect compared with nitrite and creates a weak bonding interaction with the oxygen lone pairs. The lone electron in also means that this compound is a free radical, so the formula for nitrogen dioxide is often written as . The reddish-brown color

neg: Oxygen concentrator gas remaining. PSA technology is a reliable and economical technique for small to mid-scale oxygen generation, with cryogenic separation more suitable at higher volumes and external delivery generally more suitable for small volumes. At high pressure, the porous zeolite adsorbs large quantities of nitrogen, due to its large surface area and chemical character. After the oxygen and other free components are collected the pressure drops which allows nitrogen to desorb. An oxygen concentrator has an air compressor, two cylinders filled with zeolite pellets, a pressure equalizing reservoir, and some valves and tubes. In the first half-cycle the first cylinder receives

neg: 1,8-Bis(dimethylamino)naphthalene solution, 1,8-bis(dimethylamino)naphthalene is one of the strongest organic bases - However, it only absorbs protons slowly—hence the trade name. The high basicity is attributed to the relief of strain upon protonation and/or the strong interaction between the nitrogen lone pairs. Additionally, although many aromatic amines such as aniline show reduced basicity (due to nitrogen being sp² hybridized; its lone pair occupying a 2p orbital and interacting and being withdrawn by the aromatic ring), this is not possible in this molecule, as the nitrogens' methyl groups prevent its substituents from adopting a planar geometry, as this would require forcing methyl groups