scholarly journals Dissolved nitrogen in rivers: comparing pristine and impacted regions of Brazil

2010 ◽  
Vol 70 (3 suppl) ◽  
pp. 709-722 ◽  
Author(s):  
LA Martinelli ◽  
LD. Coletta ◽  
EC. Ravagnani ◽  
PB. Camargo ◽  
JPHB. Ometto ◽  
...  
Keyword(s):  
Population Density ◽  
Anthropogenic Activities ◽  
Inorganic Nitrogen ◽  
Developed Countries ◽  
Tropical Country ◽  
Dissolved Nitrogen ◽  
The North ◽  
Nitrogen Concentrations ◽  
Fate Of Nitrogen ◽  
The Tropics

Riverine nitrogen distribution is increasingly controlled by anthropogenic activities in their watersheds, regardless of spatial scale, climate, and geographical zone. Consequently, modelling efforts to predict the export of nitrogen from rivers worldwide have used attributes such as population density, land use, urbanization and sanitation. These models have greatly enhanced our understanding of the sources and fate of nitrogen added to terrestrial systems and transported to rivers and streams, especially for developed countries of the North temperate zone. However, much of the world's population lives in developing countries of the tropics, where the effects of human activities on riverine N exports are still poorly understood. In an effort to close this gap, we compare riverine nitrogen data from 32 Brazilian rivers draining two contrasting regions in this tropical country in terms of economic development - the State of São Paulo and the Amazon. Our data include nitrogen in different dissolved forms, such as Dissolved Inorganic Nitrogen (DIN) and Dissolved Organic Nitrogen (DON). The results show that nitrogen concentrations decreased as river runoff increased in both study areas, and that concentrations were significantly higher in rivers draining the most economically developed region. The relationships between nitrogen concentrations and fluxes with demographic parameters such as population density were also determined and compared to those in temperate systems. In contrast to temperate watersheds, we found that nitrogen fluxes increased only after population densities were higher than 10 individuals per km².

Stable nitrogen isotopes as indicators of anthropogenic activities in small freshwater systems

2001 ◽  
Vol 58 (5) ◽  
pp. 870-878 ◽  
Author(s):  
James L Lake ◽  
Richard A McKinney ◽  
Frank A Osterman ◽  
Richard J Pruell ◽  
John Kiddon ◽  
...  
Keyword(s):  
Largemouth Bass ◽  
Trophic Position ◽  
Anthropogenic Activities ◽  
Inorganic Nitrogen ◽  
Micropterus Salmoides ◽  
Anthropogenic Activity ◽  
Dissolved Inorganic Nitrogen ◽  
Shoreline Development ◽  
Freshwater Systems ◽  
Nitrogen Concentrations

Stable nitrogen isotope ratios (δ15N) were measured in fish, mussel, and sediment samples taken from 17 small freshwater sites to examine food chain length and trophic position across sites affected by differing levels of anthropogenic activity. Both shoreline development and fish species composition varied greatly among sites, and a range of up to 11.2‰ was found for the δ15N values of largemouth bass (Micropterus salmoides). Fish δ15N values were baseline corrected using unionid mussel (Elliptio complanata) δ15N values. Predators, such as largemouth bass and chain pickerel (Esox niger), exhibited normalized δ15N values that were less variable than those of benthic-feeding fishes. Relationships between δ15N and dissolved inorganic nitrogen concentrations indicated that δ15N was a valid descriptor of eutrophication at sites with low dissolved inorganic nitrogen concentrations. The fraction of residential land in buffer zones surrounding sites was correlated with fish δ15N, indicating that urban development, and presumably human wastewater, resulted in elevated δ15N values in these small freshwater systems.

scholarly journals A Synechococcus PglnA::luxAB Fusion for Estimation of Nitrogen Bioavailability to Freshwater Cyanobacteria

2003 ◽  
Vol 69 (3) ◽  
pp. 1465-1474 ◽  
Author(s):  
Osnat Gillor ◽  
Ayelet Harush ◽  
Ora Hadas ◽  
Anton F. Post ◽  
Shimshon Belkin
Keyword(s):  
Light Emission ◽  
Inorganic Nitrogen ◽  
Freshwater Ecosystems ◽  
Reporter Strain ◽  
Dissolved Nitrogen ◽  
Total Dissolved Nitrogen ◽  
Response Range ◽  
Nitrogen Concentrations ◽  
Nitrate And Nitrite

ABSTRACT In contrast to extensive studies of phosphorus, widely considered the main nutrient limiting phytoplankton biomass in freshwater ecosystems, there have been few studies on the role of nitrogen in controlling phytoplankton populations. This situation may be due partly to the complexity in estimating its utilization and bioavailability. In an attempt to provide a novel tool for this purpose, we fused the promoter of the glutamine synthetase-encoding gene, P glnA, from Synechococcus sp. strain PCC7942 to the luxAB luciferase-encoding genes of the bioluminescent bacterium Vibrio harveyi. The resulting construct was introduced into a neutral site on the Synechococcus chromosome to yield the reporter strain GSL. Light emission by this strain was dependent upon ambient nitrogen concentrations. The linear response range of the emitted luminescence was 1 mM to 1 μM for the inorganic nitrogen species tested (ammonium, nitrate, and nitrite) and 10- to 50-fold lower for glutamine and urea. When water samples collected from along a depth profile in Lake Kinneret (Israel) were exposed to the reporter strain, the bioluminescence of the reporter strain mirrored the total dissolved nitrogen concentrations determined for the same samples and was shown to be a sensitive indicator of the concentration of bioavailable nitrogen.

scholarly journals FOOD AND DRINK PROCESSING FROM LYCHEE PRODUCTS IN THE NORTHERN PROVINCES OF VIETNAM - AND ROLES OF AGRICULTURE PROJECT FINANCING

2021 ◽  
Vol 33 (1) ◽  
pp. 187-195
Author(s):  
Dinh Tran Ngoc-Huy ◽  
Nguyen Thi Hang ◽  
Le Thi Thanh-Huong ◽  
Pham Van Hong
Keyword(s):  
Value Chain ◽  
Black Tea ◽  
Developed Countries ◽  
Northern Region ◽  
Tropical Country ◽  
The North ◽  
Inductive Methods ◽  
Capital Financing ◽  
Food And Drink ◽  
Trade Promotion

The purpose of this study focuses on presenting the food and drink process in the case of making lychee juice and lychee-tea combination fruit juice in a tropical country such as Vietnam. We mainly use methods of qualitative analysis, synthesis and inductive methods, with description and explanatory methods. Authors also use a value chain approach from a material supply (lychee products) to production and market distribution.Research results show us that choosing good red lychee together with good green or black tea, esp. Lipton tea, which is produced from the region of material supplying in the Northern region of Vietnam, then mixed with sugar and ice, using little vegetables will be very good for everybody health, functioning as medical treatment to prevent heart disease, and helps men and women stronger.In the meantime, we also propose lychee and tea planting policies and capital financing policies in the country, esp. In the north of Vietnam. For instance, the nation needs to continue to negotiate with countries that have not yet allowed Vietnam’s fresh lychee to be imported into developed countries (such as Korea, ...); The state/province cooperates with donors and businesses in trade promotion activities in potential export markets for Vietnamese lychee and fruit products (Japan, Korea, US, EU, ASEAN…).

scholarly journals The Pattern of Change in the Abundances of Specific Bacterioplankton Groups Is Consistent across Different Nutrient-Enriched Habitats in Crete

2014 ◽  
Vol 80 (13) ◽  
pp. 3784-3792 ◽  
Author(s):  
Stilianos Fodelianakis ◽  
Nafsika Papageorgiou ◽  
Paraskevi Pitta ◽  
Panagiotis Kasapidis ◽  
Ioannis Karakassis ◽  
...  
Keyword(s):  
Nutrient Enrichment ◽  
Anthropogenic Activities ◽  
North Coast ◽  
Common Source ◽  
Content Type ◽  
Dissolved Nitrogen ◽  
The North ◽  
Change Pattern ◽  
Α Diversity ◽  
Taxonomic Groups

ABSTRACTA common source of disturbance for coastal aquatic habitats is nutrient enrichment through anthropogenic activities. Although the water column bacterioplankton communities in these environments have been characterized in some cases, changes in α-diversity and/or the abundances of specific taxonomic groups across enriched habitats remain unclear. Here, we investigated the bacterial community changes at three different nutrient-enriched and adjacent undisturbed habitats along the north coast of Crete, Greece: a fish farm, a closed bay within a town with low water renewal rates, and a city port where the level of nutrient enrichment and the trophic status of the habitat were different. Even though changes in α-diversity were different at each site, we observed across the sites a common change pattern accounting for most of the community variation for five of the most abundant bacterial groups: a decrease in the abundance of thePelagibacteraceaeand SAR86 and an increase in the abundance of theAlteromonadaceae,Rhodobacteraceae, andCryomorphaceaein the impacted sites. The abundances of the groups that increased and decreased in the impacted sites were significantly correlated (positively and negatively, respectively) with the total heterotrophic bacterial counts and the concentrations of dissolved organic carbon and/or dissolved nitrogen and chlorophyll α, indicating that the common change pattern was associated with nutrient enrichment. Our results provide anin situindication concerning the association of specific bacterioplankton groups with nutrient enrichment. These groups could potentially be used as indicators for nutrient enrichment if the pattern is confirmed over a broader spatial and temporal scale by future studies.

WTO SUCCESSOR TO GATT

1997 ◽  
Vol 14 (2) ◽  
pp. 172-187
Author(s):  
Arif Sultan
Keyword(s):  
North Africa ◽  
European Economic Community ◽  
Developed Countries ◽  
Economic Community ◽  
Land Area ◽  
The North ◽  
Muslim Countries ◽  
The Pacific ◽  
The World ◽  
The Developed Countries

Within a short span of time a number of economic blocs have emergedon the world horizon. In this race, all countriedeveloped, developingand underdeveloped-are included. Members of the North America FreeTrade Agreement (NAITA) and the European Economic Community(EEC) are primarily of the developed countries, while the EconomicCooperation Organization (ECO) and the Association of South EastAsian Nations (ASEAN) are of the developing and underdevelopedAsian countries.The developed countries are scrambling to create hegemonies throughthe General Agreement on Tariff and Trade (GATT). In these circumstances,economic cooperation among Muslim countries should be onthe top of their agenda.Muslim countries today constitute about one-third of the membershipof the United Nations. There are around 56 independentMuslim states with a population of around 800 million coveringabout 20 percent of the land area of the world. Stretchingbetween Atlantic and the Pacific Oceans, the Muslim Worldstraddles from North Africa to Indonesia, in two major Islamicblocs, they are concentrated in the heart of Africa to Indonesia,in two major blocs, they are concentrated in the heart of Africaand Asia and a smaller group in South and Southeast Asia.'GATT is a multilateral agreement on tariffs and trade establishing thecode of rules, regulations, and modalities regulating and operating internationaltrade. It also serves as a forum for discussions and negotiations ...

scholarly journals Striking forest revival at the end of the Roman Period in north-western Europe

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
C. Lambert ◽  
A. Penaud ◽  
M. Vidal ◽  
C. Gandini ◽  
L. Labeyrie ◽  
...  
Keyword(s):  
North Atlantic ◽  
Western Europe ◽  
Anthropogenic Activities ◽  
Sedimentary Environment ◽  
Pollen Grains ◽  
Roman Period ◽  
Freshwater Microalgae ◽  
Environmental Signals ◽  
The North ◽  
North Western

AbstractThe Holocene period (last 11,700 years BP) has been marked by significant climate variability over decadal to millennial timescales. The underlying mechanisms are still being debated, despite ocean–atmosphere–land connections put forward in many paleo-studies. Among the main drivers, involving a cluster of spectral signatures and shaping the climate of north-western Europe, are solar activity, the North Atlantic Oscillation (NAO) varying atmospheric regimes and North Atlantic oceanic gyre dynamics. Over the last 2500 years BP, paleo-environmental signals have been strongly affected by anthropogenic activities through deforestation and land use for crops, grazing, habitations, or access to resources. Palynological proxies (especially pollen grains and marine or freshwater microalgae) help to highlight such anthropogenic imprints over natural variability. Palynological analyses conducted in a macro-estuarine sedimentary environment of north-western France over the last 2500 years BP reveal a huge and atypical 300 year-long arboreal increase between 1700 and 1400 years BP (around 250 and 550 years AD) that we refer to as the ‘1.7–1.4 ka Arboreal Pollen rise event’ or ‘1.7–1.4 ka AP event’. Interestingly, the climatic 1700–1200 years BP interval coincides with evidence for the withdrawal of coastal societies in Brittany (NW France), in an unfavourable socio-economic context. We suggest that subpolar North Atlantic gyre strengthening and related increasing recurrence of storminess extremes may have affected long-term coastal anthropogenic trajectories resulting in a local collapse of coastal agrarian societies, partly forced by climatic degradation at the end of the Roman Period.

scholarly journals Hookworm infection in infants: a case report and review of literature

2021 ◽  
Vol 47 (1) ◽  
Author(s):  
G. Umbrello ◽  
R. Pinzani ◽  
A. Bandera ◽  
F. Formenti ◽  
G. Zavarise ◽  
...  
Keyword(s):  
Rural Areas ◽  
Simulation Models ◽  
Developed Countries ◽  
Hookworm Infection ◽  
Case Presentation ◽  
Abdominal Symptoms ◽  
Asymptomatic Children ◽  
Ancylostoma Duodenale ◽  
Stool Analysis ◽  
The Tropics

Abstract Background Hookworm infections (Necator americanus, Ancylostoma duodenale) are common in rural areas of tropical and subtropical countries. Human acquisition results from direct percutaneous invasion of infective larvae from contaminated soil. Overall, almost 472 million people in developing rural countries are infected. According to simulation models, hookworm disease has a global financial impact of over US$100 billion a year. Hookworm infection in newborn or infancy is rare, and most of the cases reported in literature are from endemic countries. Here, we describe the case of an infant with an Ancylostoma duodenale infection and review the literature currently available on this topic. Case presentation An Italian 2-month-old infant presented with vomit and weight loss. Her blood exams showed anemia and eosinophilia and stool analysis resulted positive for hookworms’ eggs, identified as Ancylostoma duodenale with real time-PCR. Parasite research on parents’ stools resulted negative, and since the mother travelled to Vietnam and Thailand during pregnancy, we assumed a transplacental transmission of the infection. The patient was treated successfully with oral Mebendazole and discharged in good conditions. Discussion Hookworm helminthiasis is a major cause of morbidity in children in the tropics and subtropics, but rare in developed countries. Despite most of the patients is usually asymptomatic, children are highly exposed to negative sequelae such as malnutrition, retarded growth and impaired cognitive development. In infants and newborns, the mechanism of infection remains unclear. Although infrequent, vertical transmission of larvae can occur through breastfeeding and transplacentally. Hookworm infection should be taken into account in children with abdominal symptoms and unexplained persistent eosinophilia. The treatment of infants infected by hookworm has potential benefit, but further studies are needed to define the best clinical management of these cases.

Terminal ileum resection as a trigger for Strongyloides stercoralis hyperinfection and ensuing serial sepsis in a 37-year-old patient with complicated Crohnʼs disease: a case report

2018 ◽  
Vol 56 (04) ◽  
pp. 380-383 ◽  
Author(s):  
Mirjana Topić ◽  
Silvija Čuković-Čavka ◽  
Marko Brinar ◽  
Mirjana Kalauz ◽  
Ivica Škrlec ◽  
...  
Keyword(s):  
Terminal Ileum ◽  
Skin Penetration ◽  
Strongyloides Stercoralis ◽  
Developed Countries ◽  
Clinical Settings ◽  
Solid Organ ◽  
Transplant Patients ◽  
Skin Contact ◽  
Life Threatening ◽  
The Tropics

AbstractThe nematode Strongyloides stercoralis, outside the tropics and subtropics present in small endemic foci, can cause an infection after direct skin contact with contaminated soil containing infective filariform larvae and, rarely, after intimate interhuman contact or after transplantation of an infected solid organ. Following skin penetration, migration, and maturation through several stages, a small number of invasive filariform larvae can develop anew in the gut lumen, perpetuating new cycles of penetration, tissue migration, and reproduction, without leaving the host.In a state of immunosuppression, autoinfection can progress to life-threatening hyperinfection and/or infection disseminated through virtually any organ. In developed countries, the most frequently recognized risk for severe hyperinfection is corticosteroid therapy, but this has been also described in malnourished, alcoholic, cancer, and transplant patients. Due to the frequent need for immunosuppressive therapy, patients suffering from inflammatory bowel disease (IBD) are susceptible to develop overwhelming strongyloidiasis. Strongyloidiasis can be easily overlooked in clinical settings, and in many European regions there is poor insight into the epidemiological burden of this disease.We present a case of S. stercoralis hyperinfection that triggered 3 successive episodes of sepsis caused by pathogens of the gut flora in a young patient suffering from stenotic form of Crohn’s disease. S. stercoralis hyperinfection occurred in the corticosteroid-free period, shortly after resection of the terminal ileum, which was probably the trigger for the overwhelming course. The patient was successfully treated with 10-day albendazole therapy.

Nitrogen cycling in a Venezuelan tropical seasonally flooded forest: soil nitrogen mineralization and nitrification

1994 ◽  
Vol 10 (3) ◽  
pp. 399-416 ◽  
Author(s):  
Barrios E. ◽  
Herrera R.
Keyword(s):  
Soil Nitrogen ◽  
Nitrogen Availability ◽  
Inorganic Nitrogen ◽  
Nitrogen Concentration ◽  
Ammonium Nitrogen ◽  
Wet Season ◽  
Flooded Forest ◽  
Nitrogen Concentrations ◽  
Minimum Stress ◽  
Seasonally Flooded

ABSTRACTSeasonally flooded forests represent a transition between terrestrial and aquatic ecosystems. The Mapire river, a tributary of the Orinoco river, floods its surrounding forests during the wet season (May–December). The soils are very acid and the total nitrogen concentration (0.1%) is only half that found in nearby soils flooded by Orinoco waters. Ammonium-nitrogen predominates in the soil during the flooded period while nitrate-nitrogen concentrations are higher in the dry period. Wide fluctuations in the inorganic nitrogen fractions did not considerably affect the annual course of soil nitrogen.The predominance of mineralization versus nitrification (56 and 5 μgsoil month−1respectively) and possibly the synchronization of nitrogen availability with plant demand could be considered as nitrogen conserving mechanisms.In synchrony with the hydrologic cycle, the seasonally flooded forest studied shows a nitrogencycle where inputs and accumulation are maximized when the system is under minimum stress (dry season). During flooding, the system enters a period of dormancy making minimal use of nutrient and energy to avoid or tolerate anaerobiosis.

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