Groundwater quality assessment in semi-arid regions using integrated approaches: the case of Grombalia aquifer (NE Tunisia).

PubMed

Kammoun, Siwar; Trabelsi, Rim; Re, Viviana; Zouari, Kamel; Henchiri, Jihed

2018-01-19

As many arid and semi-arid regions in the Mediterranean Basin, the Grombalia coastal aquifer (NE Tunisia) is affected by severe groundwater exploitation and contamination. Therefore, quality assessments are becoming increasingly important as the long-term protection of water resources is at stake. Multidisciplinary investigations, like the one presented in this paper, are particularly effective in identifying the different origins of mineralization within an aquifer and investigating the impact of anthropogenic activities on groundwater quality. An integrated assessment, focused on the combined use of geostatistical, geochemical and isotopic (δ 18 O, δ 2 H and 3 H) tools, was performed in the Grombalia aquifer between February and March 2014. The overall goal was to study the main processes controlling aquifer salinization, with special focus to nitrate contamination. Results indicate a persisting deterioration of water quality over the whole basin except the south-eastern zone juxtaposing the recharge area of the aquifer. Nitrate contents exceed the drinking water standard (50 mg/l) in 70% of groundwater samples, mainly due to the excessive use of fertilizers and urban activities. Stable isotope measurements showed the contribution of modern rainwater to aquifer recharge and proved the presence of evaporation contributing to the salinity increase. Tritium values of groundwater samples suggested two hypotheses: the existence of mixture between old and recent water or/and the existence of two recharge periods of the aquifer, pre- and post-nuclear weapons test. Principal component analysis confirmed the geochemical interpretation, highlighting that water-rock interaction evaporation effect and intensive anthropogenic activities constitute the main processes controlling the regional groundwater mineralization.

The Educational System of Tunisia.

ERIC Educational Resources Information Center

Office of Education (DHEW), Washington, DC.

An overview of the basic system of education in Tunisia is presented in this booklet. Since Tunisia's independence in 1956, the government has emphasized the role of education as a major factor in building a modern nation. The educational system in Tunisia is based on both the nation's own rich cultural background and also on the linguistic and…

Tunisia Country Analysis Brief

EIA Publications

2014-01-01

Tunisia is a relatively small hydrocarbon producer. Production of petroleum and other liquids has been steadily declining from its peak of 120,000 barrels per day (bbl/d) in the mid-1980s to 60,000 bbl/d in 2013. Tunisia produced 66 billion cubic feet of dry natural gas in 2012.

Coniacian-Turonian Carbonates of the Miskar Field, offshore Tunisia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Knott, I.; Moody, R.; Sandman, R.

1995-08-01

The R1 and R1 Superior Carbonates of the Miskar Field, offshore Tunisia are of Coniacian-Turonian age. These ages are constrained by several biostratigraphic events including a rapid increase in ostracod diversity at the base of the overlying Aleg Formation and the occurrence of several diagnostic benthonic foraminifera including Rotalia algeriana. The indication is that the R1 and R1 Superior Carbonates are the lateral equivalents, in part, of the Douleb Formation which is a known reservoir, onshore Tunisia. During the Coniacian-Turonian the area of the Miskar Field was subject to regional extension with the opening of several major North-South trending fractures.more » These culminate in the contemporaneous outpouring of submarine serpentinized volcanics during deposition of the R1 Superior/Aleg Formation. The R1 lithologies are deposited in a shallow water regime and consist of rudist buildup and debraic carbonates overlain by lagoonal facies in the North with an increase in beach/sabkha facies to the South. The indication is for a shallowing upward sequence and a general progradation of lithofacies northwards across a tilted block. In contrast the R1 Superior is indicative of a flooding event with relative sea-level changes reflected in variations of both lithofacies and biofacies. Overall the lithofacies are dominated by calcispheric/bioclastic wackestone-packstones probably deposited in a mid-platform setting. The diagenetic history of the R1 is the more complex of the two carbonate sequences reflecting several phases of fluid movement through the constituent lithologies. Original depositional characteristics and subsequent diagenetic meditation result in the development of highly variable reservoir properties.« less

Tunisia: Islam as a Political Force

DTIC Science & Technology

1992-06-18

Program Element Number Project No. Task Work Unit Accession No. II Title (Include Security Classification) Tunisia : Islam as a Political Force 12...necessary and identify by block number) Tunisia , Islam, Habib Bourguiba, Colonial France, Zine ben Ali, Rachid Ghannouchi, North Africa, L;.S./Tunisian...vernments o•l these countries. In Tunisia , the government has virtually halted its promised democratic reforms claimig that the Islamists will use

Late Miocene extensional systems in northern Tunisia and their relation with SE directed delamination of the African subcontinental mantle lithosphere

NASA Astrophysics Data System (ADS)

Booth-Rea, Guillermo; Gaidi, Seif; Melki, Fetheddine; Pérez-Peña, Vicente; Marzougui, Wissem; Azañón, Jose Miguel; Galve, Jorge Pedro

2017-04-01

Recent work has proposed the delamination of the subcontinental mantle lithosphere under northern Tunisia during the late Miocene. This process is required to explain the present location of the Tunisian segment of the African slab, imaged by seismic tomography, hanging under the Gulf of Gabes to the south of Tunisia. Thus, having retreated towards the SE several hundred km from its original position under the Tellian-Atlas nappe contact that crops out along the north of Tunisia. However, no tectonic structures have been described which could be related to this mechanism of lithospheric mantle peeling. Here we describe for the first time extensional fault systems in northern Tunisia that strongly thinned the Tellian nappes, exhuming rocks from the Tunisian Atlas in the core of folded extensional detachments. Two normal fault systems with sub-orthogonal extensional transport occur. These were active during the late Miocene associated to the extrusion of 13 Ma granodiorite and 9 Ma rhyodacite in the footwall of the Nefza detachment. We have differentiated an extensional system formed by low-angle normal faults with NE- and SW-directed transport cutting through the Early to Middle Miocene Tellian nappen stack and a later system of low and high-angle normal faults that cuts down into the underlying Tunisian Atlas units with SE-directed transport, which root in the Nefza detachment. Both normal fault systems have been later folded and cut by thrusts during Plio-Quaternary NW-SE directed compression. These findings change the interpretation of the tectonic evolution of Tunisia that has always been framed in a transpressive to compressive setting, manifesting the extensional effects of Late Miocene lithospheric mantle delamination under northern Tunisia.

Using hydrochemistry, tracers and isotopes to analyze hydrogeological dynamics and eutrophication processes in coastal lagoons

NASA Astrophysics Data System (ADS)

Menció, Anna; Mas-Pla, Josep; Quintana, Xavier D.

2016-04-01

Wetlands and coastal lagoons in Mediterranean areas have recently been the focus of an increasing interest due to the degradation of their ecological status in terms of declining biodiversity, alteration of ecological functioning and limitation of the ecosystem services they provide. Accordingly, the Horizon 2020 Programme of the European Union has set, as one of its priorities, to prevent a further degradation of these ecosystems and to recover their ecological functioning. The aim of this project is to analyze the hydrogeological dynamics in the Pletera coastal lagoons (NE, Spain) as a basis to propose guidelines for their sustainable management. Thus, monthly hydrochemical (with major ions, nutrients and tracers) and isotopic (δ18OH2O and δD) campaigns have been conducted, from November 2014 to October 2015, to determine the hydrogeological dynamics of the Pletera lagoons. In addition, in some of the sampling campaigns δ34SSO4, δ18OSO4, δ15NNO3 and δ18ONO3 have also been analyzed to determine the origin of eutrophication problems observed in these lagoons, mainly caused by nitrogen compounds. Project founded by MEC CGL-2014-57215-C4-2R and LIFE 13 NAT/ES/001001

Tunisia cours complementaire (Tunisia Complementary Course).

ERIC Educational Resources Information Center

Peace Corps (Thailand).

The instructional materials in French are designed for use by language trainers of Peace Corps volunteers serving in francophone Tunisia, to supplement situational language and grammar instruction. A brief introductory section offers strategies for teaching verb tenses. The diverse materials that follow include lists of situational questions in…

English Language Development in Tunisia.

ERIC Educational Resources Information Center

Daoud, Mohamed

1996-01-01

Describes English language policy decisions and implementation strategies in Tunisia and highlights the problems accompanying them. The article emphasizes that Tunisia has entered a critical stage in the promotion of English as the language of economic, scientific, and technological development and that the educational system must develop programs…

Comparative oceanography of coastal lagoons

NASA Technical Reports Server (NTRS)

Kjerfve, Bjorn

1986-01-01

The hypothesis that physical lagoon characteristics and variability depend on the channel connecting the lagoon to the adjacent coastal ocean is evaluated. The geographical, hydrological, and oceanographic characteristics of 10 lagoon systems are described and analyzed; these oceanographic features are utilized to classify the lagoon systems. Choked lagoons (Laguna Joyuda, Coorong, Lake St.Lucia, Gippsland Lakes, Lake Songkla/Thale Luang/Thale Noi, and Lagoa dos Patos) are prevalent on coasts with high wave energy and low tidal range; restricted lagoons (Lake Pontchartrain and Laguna de Terminos) are located on low/medium wave energy coasts with a low tidal range; and leaky lagoons (Mississippi Sound and Belize Lagoon/Chetumal Bay) are connected to the ocean by wide tidal passes that transmit oceanic effects into the lagoon with a minimum of resistance. The data support the hypothesis that the nature of the connecting channel controls system functions.

Zooplankton taxonomic and size diversity in Mediterranean coastal lagoons (NE Iberian Peninsula): Influence of hydrology, nutrient composition, food resource availability and predation

NASA Astrophysics Data System (ADS)

Badosa, Anna; Boix, Dani; Brucet, Sandra; López-Flores, Rocío; Gascón, Stéphanie; Quintana, Xavier D.

2007-01-01

The influence of hydrology, nutrient composition, food resource availability and predation on zooplankton taxonomic and size diversity was analyzed in several shallow lagoons of a Mediterranean salt marsh (Baix Ter Wetlands, NE Iberian Peninsula). Taxonomic diversity correlated better with variables related to the trophic state, such as nutrient concentrations, whereas size diversity was more sensitive to fish predation. However, the fish predation influence on the size diversity was only significant when fishes reached high densities. Under low fish densities no predation effects were observed and the food resource availability (FR a) appeared to be more important in structuring the zooplankton community. Nevertheless, the two diversity indexes showed opposite responses to this factor. With increasing FR a the taxonomic diversity increased and the size diversity decreased. Neither taxonomic nor size diversity of the zooplankton community correlated with other physical or biotic factors such as hydrological variability or macroinvertebrate predation. The relationships found suggest that the size diversity is mainly related to biotic interactions, such as fish predation or inter/intraspecific competition, while the taxonomic diversity appears to be more sensitive to abiotic factors such as the nutrient composition.

Organ transplantation in Tunisia.

PubMed

El Matri, Aziz; Ben Abdallah, Taieb

2015-04-01

Kidney transplants were first performed in Tunisia in 1986, and transplants soon extended to other organs including the heart, liver, and pancreas. Live-related donor and deceased-donor kidney transplants were both began in the summer of 1986. An organ procurement and transplant law was passed in March 1991, and the National Centre for Advancement of Organ Transplantation was created in 1995. The number of transplantation units has increased to 7 throughout the country, and the yearly transplant number has progressively increased to 139 in 2010, including 20% from deceased kidney donors. Despite these gains, the need continues to grow. Heart transplants began in January 1993, and Tunisia and Jordan are currently the only Arab countries where it is practiced. However, only 16 patients have received a heart transplant as of 2004, and the number of recipients has decreased in the past 10 years. Liver transplants are rare in other Arab countries, but began in Tunisia in January 1998. Over 10 years, 38 patients benefited from this procedure. After a few years of stagnation, the number of liver transplants is increasing. While all types of transplantation are needed, kidney transplantation is a priority in Tunisia. The target is to perform 400 transplants annually, which would require a long-term strategy to provide full financial coverage using the National Health Insurance Funds in both the public and private sectors.

The plankton food web of the Bizerte Lagoon (South-western Mediterranean): II. Carbon steady-state modelling using inverse analysis

NASA Astrophysics Data System (ADS)

Grami, Boutheïna; Niquil, Nathalie; Sakka Hlaili, Asma; Gosselin, Michel; Hamel, Dominique; Hadj Mabrouk, Hassine

2008-08-01

A steady-state model of the planktonic food web of the Bizerte Lagoon (Tunisia, South-western Mediterranean) was developed to characterize its structure and functioning through four stations: MA under urban discharge, MB impacted by industrial input, MJ located at proximity of shellfish farming and R in the central area of the lagoon. Carbon stocks of eight chosen compartments were determined and flows were assigned for each one from field data. Missing flow values were calculated by inverse analysis for each station. Network analysis was applied to the resulting food web models to characterize their properties. These analyses mainly showed similarity among stations concerning (1) a high primary production of phytoplankton which was dominated by >10 μm cells (i.e. diatoms); (2) important herbivory against detritivory in stations MA and MJ; (3) major role of detritivory in stations MB and R; (4) efficiency of microbial link in transferring carbon for higher trophic level; (5) efficiency of microzooplankton as a trophic link between detritus, dissolved organic carbon, autotrophs and mesozooplankton; (6) important recycling of carbon leading to conclude about an immature state of the ecosystem. Differences between the functioning of microbial food webs in the lagoon are mainly due to the location of stations. The proximity of station MB to inland and industrial discharges affected its productivity and made it the least productive station. Water circulation into the lagoon made pollutant concentrate into the south and the western sections which seemed to affect the planktonic food web, since the values of productivity reported for stations MB and R were lower than those calculated for the others stations.

Pesticides in Ichkeul Lake-Bizerta Lagoon Watershed in Tunisia: use, occurrence, and effects on bacteria and free-living marine nematodes.

PubMed

Salem, Fida Ben; Said, Olfa Ben; Aissa, Patricia; Mahmoudi, Ezzeddine; Monperrus, Mathilde; Grunberger, Olivier; Duran, Robert

2016-01-01

This study aimed to identify the most commonly used agricultural pesticides around Ichkeul Lake-Bizerta Lagoon watershed. First survey of pesticide use on agricultural watershed was performed with farmers, Regional Commissioner for Agricultural Development, and pesticide dealers. Then, sediment contamination by pesticides and response of benthic communities (bacteria and free-living marine nematode) were investigated. The analysis of 22 active organochlorine pesticides in sediments was performed according to quick, easy, cheap, effective, rugged, and safe (QuEChERS) method, biodiversity of indigenous bacterial community sediment was determined by terminal restriction fragment length polymorphism (T-RFLP), and free-living marine nematodes were counted. The results of the field survey showed that iodosulfuron, mesosulfuron, 2,4-dichlorophenoxyacetic acid (2,4 D), glyphosate, and fenoxaprops were the most used herbicides, tebuconazole and epoxiconazole the most used fungicides, and deltamethrin the most used insecticide. Sixteen organochlorine pesticide compounds among the 22 examined were detected in sediments up to 2 ppm in Ichkeul Lake, endrin, dieldrin, and hexachlorocyclohexane being the most detected molecules. The most pesticide-contaminated site in the lake presented the higher density of nematode, but when considering all sites, no clear correlation with organochlorine pesticide (OCP) content could be established. The bacterial community structure in the most contaminated site in the lake was characterized by the terminal restriction fragments (T-RFs) 97, 146, 258, 285, and 335 while the most contaminated site in the lagoon was characterized by the T-RFs 54, 263, 315, 403, and 428. Interestingly, T-RFs 38 and 143 were found in the most contaminated sites of both lake and lagoon ecosystems, indicating that they were resistant to OCPs and able to cope with environmental fluctuation of salinity. In contrast, the T-RFs 63, 100, 118, and 381 in the lake and the T

PAH (Polycyclic Aromatic Hydrocarbon) bioaccumulation and PAHs/shell weight index in Ruditapes philippinarum (Adams & Reeve, 1850) from the Vallona lagoon (northern Adriatic Sea, NE Italy).

PubMed

Cacciatore, Federica; Bernarello, Valentina; Boscolo Brusà, Rossella; Sesta, Giulio; Franceschini, Gianluca; Maggi, Chiara; Gabellini, Massimo; Lamberti, Clauda Virno

2018-02-01

The Vallona lagoon is a transitional area located in the Po River delta (NE, ITALY) traditionally exploited for Manila clam (Ruditapes philippinarum) farming. During 2007-2008, a pipeline was buried in the middle of the lagoon to connect an off-shore structure to facilities on land. PAH levels were monitored in Manila clams and sediments before, during and after the pipeline construction to assess the impact of the activities through the pattern of distribution of the PAH compounds. PAH bioaccumulation in clams displayed seasonal fluctuations with higher levels in autumnal and wintry surveys than in spring-summer. Principal component analysis applied to PAHs in clams highlighted a petrogenic input during ante operam period and a pyrolytic origin during the burying activities. On the contrary, sediment PAH concentrations resulted quite similar both among sites and periods. Biota-Sediment-Accumulation-Factor values also confirmed that sediments were not the major source of PAH pollution for clams in this study. The welfare of clams was examined through two physiological indices (condition index and survival in air) to check the effects of the activities on a commercial resource. Both physiological indices exhibited seasonal variations connected to natural endogenous and exogenous factors; however survival in air was the most sensitive index in highlighting the effects of the pipeline burying activities. Finally, to ensure that PAH bioavailability assessment was not affected by seasonal variation of soft tissues of molluscs, PAHs/shell weight index was applied. Higher levels of this index were observed before and during the burying activities, whilst, after that, values significantly lowered. Moreover, the normalization enabled us to highlight the PAH uptake from clams in some particular periods and to compare different populations in a long-term biomonitoring program with data obtained from different periods of the year. Copyright © 2017 Elsevier Inc. All rights

Lagoon Restoration Project: Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

This project is a multiyear effort focusing on energy flow in the Palace of Fine Arts lagoon just outside the Exploratorium in San Francisco. Phase 1 was a pilot study to determine the feasibility of improving biological energy flow through the small freshwater lagoon, using the expertise and resources of an environmental artist in collaboration with museum biologists and arts department staff. The primary outcome of Phase 1 is an experimental fountain exhibit inside the museum designed by public artist Laurie Lundquist with Exploratorium staff. This fountain, with signage, functions both as a model for natural aeration and filtration systemsmore » and as a focal point for museum visitors to learn about how biological processes cycle energy through aquatic systems. As part of the study of the lagoon`s health, volunteers continued biweekly bird consus from March through September, 1994. The goal was to find out whether the poor water quality of the lagoon is affecting the birds. Limited dredging was undertaken by the city Parks and Recreation Department. However, a more peermanent solution to the lagoon`s ecological problems would require an ambitious redesign of the lagoon.« less

Brazil The Duck Lagoon

NASA Technical Reports Server (NTRS)

2002-01-01

This Multi-angle Imaging SpectroRadiometer (MISR) image of Brazil covers an area of about 298 kilometers x 358 kilometers, and was captured by the instrument's vertical-viewing (nadir) camera on December 27, 2001. The 'Lagoa dos Patos', in the Brazilian state of Rio Grande do Sul, translates to 'the Duck Lagoon'. It was named by 16th century Jesuit settlers, who asked the King of Spain to grant them title to the lagoon so that they could breed ducks. The King consented, but revoked his edict when he discovered that the 'duck-pond' (measuring about 14,000 square kilometers) was one of the largest lagoonal systems in the world. Note the sediment plume emanating from the southern end of the lagoon. Sailors in the 16th century imagined this outlet to be the mouth of a large river. Early Portuguese explorers mistook the entrance to the lagoon for the mouth of a great river and called it the Rio Grande. A series of wave-like points and curls form 'cusps' on the inner shores of the lagoon. The lagoon's characteristics change with short-term tide-induced cyclic perturbations, and with longer term large scale meteorological conditions. The distinctive wavelike 'cusps' along the inner shores result from the circulation, erosion and accumulation of sediments driven by wind and tidal action. The El Nino Southern Oscillation (ENSO) circulation affects precipitation amount and continental runoff, thereby changing the contents of the lagoon waters. High rainfall and increased freshwater discharge during El Nino events correspond with elevated dissolved nutrient concentrations and increased phytoplankton growth. La Nina years are dry and the associated low rainfall reduces the freshwater recharge to the lagoon, causing an increase in salinity. Occasional blooms of toxic cyanobacteria (Microcystis aeruginosa), have been registered in the lagoon when nutrient concentrations are elevated. A number of reeds and grasses are important to the lagoon estuary, including widgeon grass

Brazil: Duck Lagoon

Atmospheric Science Data Center

2013-04-18

article title:  Brazil - The Duck Lagoon     View Larger Image ... the Brazilian state of Rio Grande do Sul, translates to "the Duck Lagoon". It was named by 16th century Jesuit settlers, who asked the King ...

Evidences of "Lago-Mare" episode around the Messinian-Pliocene boundary in eastern Tunisia (central Mediterranean)

NASA Astrophysics Data System (ADS)

Frigui, Mouna; Ben Youssef, Mohamed; Ouaja, Mohamed

2016-11-01

Eight stratigraphic sections, located in northeastern part of the Sahel area of Tunisia recorded evidences of "Lago-Mare" episode and events related to the Messinian-Late Pliocene interval. A comparison with previous studies carried on sections from neighboring areas and boreholes data drilled within the Gulf of Hammamet and the Gulf of Gabès, is conducted and gives useful information to characterize the Late Messinian to Late Pliocene events. The most notable feature distinguished in the studied area consists on the lack of gypsum, commonly recorded in relation with the crucial event of the Messinian Salinity Crisis. However, only lagoonal deposits, bearing messinian brackish fauna, are encountered. These sediments are usually attributed to the "Segui" formation or the so called "Mio-Pliocene continental". Thin sections samples and field observations have recognized sands, marls, clays, lacustrine limestone, some gypsum lenses, mud-cracks, lignite and Messinian brackish fauna. Similar deposits were previously described in the Kechabta basin from the Northern Tunisia and in some wells from the Gulf of Gabès and the Gulf of Hammamet. We suggest that all these facies belong to the coeval of the "Lago-Mare" facies within Eastern and Western Mediterranean basins (e.g. Sicily, Mallorca, Libya and Cyprus). Finally, four major erosional surfaces have been recorded within the Late Messinian-Late Pliocene deposits, aged post-Tortonian, intra-Messinian, Late Messinian and intra-Pliocene times. They seem to be the result of local tectonic uplifts and eustatic fluctuations.

Factors driving the seasonal distribution of zooplankton in a eutrophicated Mediterranean Lagoon.

PubMed

Ziadi, Boutheina; Dhib, Amel; Turki, Souad; Aleya, Lotfi

2015-08-15

The distribution of the zooplankton community was studied along with environmental factors at five sampling stations in Ghar El Melh Lagoon (GML) (Mediterranean Sea, northern Tunisia). GML is characterized by specific following properties: broad and shallow, freshwater supply (Station 1); connection to the sea (S2); stagnation (S3 especially), and eutrophic conditions with enhanced nutrient concentrations (S4 and S5). Samples were taken twice monthly from February 2011 to January 2012. Twenty-three zooplankton groups comprising 10 larval stages were identified. Zooplankton assemblages were largely dominated by copepods (37.25%), followed respectively by ciliates (21.09%), bivalve larvae (14.88%) and gastropod veligers (12.53%). Redundancy analysis indicated that while no significant difference was found in the distribution of zooplankton at any station, a strong difference was observed according to season. Both temporal and physicochemical fluctuations explain more than 50% of changes in zooplankton abundances. Copyright © 2015 Elsevier Ltd. All rights reserved.

Mud deposit formation on the open coast of the larger Patos Lagoon-Cassino Beach system

NASA Astrophysics Data System (ADS)

Vinzon, S. B.; Winterwerp, J. C.; Nogueira, R.; de Boer, G. J.

2009-03-01

This paper proposes an explanation of the mud deposits on the inner Shelf of Cassino Beach, South Brazil, by using computational modeling. These mud deposits are mainly formed by sediments delivered from Patos Lagoon, a coastal lagoon connected to the Shelf, next to Cassino Beach. The deposits are characterized by (soft) mud layers of about 1 m thick and are found between the -5 and -20 isobaths. Two hydrodynamic models of the larger Patos Lagoon-Cassino Beach system were calibrated against water elevation measured for a 5 months period, and against currents and salinity measured for a week period. The circulation patterns and water exchange through the mouth were analyzed as a function of local and remote wind effects, and river discharges. The remote wind effect mainly governs the quantity of water exchange with the Lagoon through its effect on mean sea level as a result of Ekman dynamics, while river discharges are important for the salinity of the exchanged water masses. Local winds augment the export-import rates by set-up and set-down within the Lagoon, but their effects are much smaller than those of the remote wind. Currents patterns on the inner Shelf during water outflow revealed a recirculation zone south of the Lagoon, induced by the local geometry and bathymetry of the system. This recirculation zone coincides with observed locations of mud deposition. Water, hence suspended sediment export occurs when remote and local winds are from the N-E, which explains why fine sediment deposits are mainly found south of the Lagoon's breakwater. A sensitivity analysis with the numerical model quantified the contribution of the various mechanisms driving the transport and fate of the fine suspended sediments, i.e. the effects of remote and local wind, of the astronomical tide, of river discharge and fresh-salt water-induced density currents, and of earth rotation. It is concluded that gravitational circulation and earth rotation affects the further dispersion of

Patterns of seasonal variation in lagoonal macrozoobenthic assemblages (Mellah lagoon, Algeria).

PubMed

Magni, Paolo; Draredja, Brahim; Melouah, Khalil; Como, Serena

2015-08-01

In coastal lagoons, many studies indicated that macrozoobenthic assemblages undergo marked temporal fluctuations as related to the strong environmental variability of these systems. However, most of these studies have not assessed the seasonal patterns of these fluctuations and none of them has investigated the consistency of this variation in different areas within the same lagoon system. In this study, we assessed patterns of variation at multiple temporal (date, season and year) scales in two different areas in the coastal lagoon of Mellah (northeast Algeria). These areas (hereafter Shore and Center) are representative of two different environments typically found in coastal lagoons. The Shore (water depth of about 1.5-2 m) is characterized by relatively higher hydrodynamics, sand to silty-sand sediments and the presence of vegetation (Ruppia maritima), the Center (water depth of about 3-3.5 m) is characterized by mud to sandy-mud, organic-enriched sediments due to fine particle accumulation. Results showed two distinct patterns of seasonal variation in Shore and Center assemblages for two consecutive years. In Shore, species richness (S), total abundance (N) and the abundance of several dominant taxa were highest in summer and/or autumn. This pattern can be related to the local environmental conditions maintaining relatively well oxidized conditions, while increasing food availability, and favoring the recruitment of species and individuals in summer/autumn. On the contrary in Center, S was lowest in summer and autumn, and N and the abundance of fewer dominant taxa were lowest in summer. In Center, the bivalve Loripes lucinalis showed a 10-fold increase from summer to autumn in both years, likely related to the lagoon's hydrodynamics favoring larval transport and settlement in the central sector of the lagoon. Overall, the seasonal variation found in Center followed a regression/recovery pattern typical of opportunistic assemblages occurring in confined

The fate of Mediterranean lagoons under climate change

NASA Astrophysics Data System (ADS)

Umgiesser, Georg; Ferrarin, Christian; Cucco, Andrea; De Pascalis, Francesca; Ghezzo, Michol; Bellafiore, Debora; Bajo, Marco

2014-05-01

A numerical model (SHYFEM) has been applied to 10 Mediterranean lagoons and a comparison study between the lagoons has been carried out. The lagoons are the lagoons of Venice, Marano-Grado, Varano and Lesina in the Adriatic Sea, the Taranto basin in the Ionian Sea, the Cabras lagoon in Sardinia, and the lagoons of Ganzirri and Faro in Sicily, the Mar Menor in Spain and the Nador lagoon in Morocco. These lagoons give a representative picture of the lagoons situated around the Mediterranean basin. The lagoons range from a leaky type of lagoons to a choked type. The number of inlets ranges from just one in the Nador lagoon to 6 in the case of the Marano-Grado lagoons. Tidal range is from nano-tidal to micro-tidal. The depth ranges from an average depth of 1 m to up to 40 meters. The model is a finite element model, especially suited to shallow water basins with complicated geometric and morphologic variations. The model can compute the basic hydrodynamics, dispersion of tracers, temperature and salinity evolution, sediment transport and ecological parameters. Building on an earlier study that focused on the classification of Mediterranean lagoons based on hydrodynamics, exchange rates and renewal time, this study is concerned with the changes in physical parameters under climate change. Data from IPCC has been used to simulate the changes in renewal time, salinity and temperature of all lagoons, with respect to the control simulation. Whenever possible downscaled data for the Mediterranean basin have been used. Sea level rise scenarios are taken from the last IPCC report. The model has been applied in its 3D version and the chosen setup allows a comparison between results in the different lagoons. Results indicate that the differences of renewal time between all studied lagoons become smaller. This means that leaky lagoons become less leaky and choked lagoons less choked. What concerns temperature and salinity, changes occurring in the sea are amplified inside lagoons

Metals in some lagoons of Mexico.

PubMed

Vazquez, F G; Sharma, V K; Alexander, V H; Frausto, C A

1995-02-01

The concentrations of metals, Cd, Cu, Fe, Mn, Ni, Pb, and Zn were determined in some lagoons to establish the level of metal pollution. The lagoons studied were Alvarado lagoon, Veracruz; San Andres lagoon, Tamaulipas; and Terminos lagoon, Campeche. The concentrations were determined in water, oyster (Crassostrea virginica), and sediments. Metals were accumulated in either oysters or sediments. Cu and Zn were higher in oysters and Fe and Mn were higher in sediments. The results in water samples were compared with the limit established by the Secretaria de Ecologia and Desarrollo Urbano Report and briefly discussed.

Metals in some lagoons of Mexico.

PubMed Central

Vazquez, F G; Sharma, V K; Alexander, V H; Frausto, C A

1995-01-01

The concentrations of metals, Cd, Cu, Fe, Mn, Ni, Pb, and Zn were determined in some lagoons to establish the level of metal pollution. The lagoons studied were Alvarado lagoon, Veracruz; San Andres lagoon, Tamaulipas; and Terminos lagoon, Campeche. The concentrations were determined in water, oyster (Crassostrea virginica), and sediments. Metals were accumulated in either oysters or sediments. Cu and Zn were higher in oysters and Fe and Mn were higher in sediments. The results in water samples were compared with the limit established by the Secretaria de Ecologia and Desarrollo Urbano Report and briefly discussed. PMID:7621796

How climate change threats water resource: the case of the Thau coastal lagoon (Mediterranean Sea, France)

NASA Astrophysics Data System (ADS)

La Jeunesse, Isabelle; Sellami, Haykel; Cirelli, Claudia

2014-05-01

The latest reports of the intergovernmental panel on climate change explained that the Mediterranean regions are especially vulnerable to the impacts of climate change. These latest are expected to have strong impacts on the management of water resources and on regional economies. The aim of this paper is to discuss impacts of climate changes on the Thau case study in relation to the evolution of water balance, water uses and adaptation to climate change. The Thau coastal lagoon is located in the Mediterranean coast in south of France in the Languedoc-Roussillon Region. Economic activities are diverse from shellfish farming, fertilizers industries to agriculture and tourism. However, tourism and shellfish farming are of major importance for local economy. If tourism is mainly turned to the Sea coast, shellfishes grow within the lagoon and rely on water quality. Previous studies have demonstrated the link between the coastal lagoon water quality and inputs of freshwater from the catchment. Thus, changes in rainfalls, runoff and water balance would not only affect water uses but also water quality. Climate changes projections are presented following the implementation of 4 downscaled climatic models. Impacts on water balance are modelled with SWAT (Soil Water Assessment Tool) for 2041-2070 compared to the 1971-2000 reference period. The decrease of precipitations and water balance will impact discharges and thus decrease the freshwater inputs to the coastal lagoon. A study of water uses conducted in interactions with stakeholders within the Thau area has permitted to assess both current and evolution of water uses. It has revealed local water resources are depleting while water demand is increasing and is planned to continue to increase in the really near future. To prevent water scarcity events, mainly due to the climate change context, the Regional authorities have connected the catchment to the Rhône river to import water. The conclusion of this study is while

Dynamics of harmful dinoflagellates driven by temperature and salinity in a northeastern Mediterranean lagoon.

PubMed

Dhib, Amel; Frossard, Victor; Turki, Souad; Aleya, Lotfi

2013-04-01

To attempt to determine the effects of temperature and salinity on the dynamics of the dinoflagellate community, a monthly sampling was carried out from October 2008 to March 2009 at eight sampling stations in Ghar El Melh Lagoon (GML; Mediterranean Sea, Northern Tunisia). Dinoflagellates were dominant among plankton, accounting for 73.9 % of the lagoon's overall plankton community, and were comprised of 25 different species among which 17 were reported in the literature as harmful. While no significant difference was found in the distribution of dinoflagellates among the stations, a strong monthly difference was observed. This temporal variability was due to an increase in the abundance of Prorocentrum micans from December to February, leading to a strong decrease in the Shannon diversity index from station to station. At the onset of P. micans development, dinoflagellate abundances reached 1.26.10(5) cells l(-1). A redundance analysis indicates that both temperature and salinity have a significant effect on the dynamics of the dinoflagellate community. Using a generalized additive model, both temperature and salinity appear to have significant nonlinear relationships with P. micans abundances. Model predictions indicate that outbreaks of P. micans may occur at a temperature below 22.5 °C and with salinity above 32.5. We discuss our results against a backdrop of climate change which, by affecting temperature and salinity, is likely to have an antagonistic impact on P. micans development and subsequently on the dinoflagellate dynamics in GML.

Lagoon Seepage Testing Report for Central Facilities Area (CFA) Sewage Lagoons at Idaho National Laboratory, Butte County, Idaho

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morrison, Bridger

J-U-B ENGINEERS, Inc. (J-U-B) performed seepage tests on the CFA Wastewater Lagoons 1, 2, and 3 between August 26th and September 22nd, 2014. The lagoons were tested to satisfy the Idaho Department of Environmental Quality (DEQ) Rules (IDAPA 58.01.16) that require all lagoons be tested at a frequency of every 10 years and the Compliance Activity CA-141-03 in the DEQ Wastewater Reuse Permit for the CFA Sewage Treatment Plant (LA-000141-03). The lagoons were tested to determine if the average seepage rates are less than 0.25 in/day, the maximum seepage rate allowed for lagoons built prior to April 15, 2007. Themore » average seepage rates were estimated for each lagoon and are given in Table-ES1. The average seepage rates for Lagoons 1 and 2 are less than the allowable seepage rate of 0.25 in/day. Lagoon 1 and 2 passed the seepage test and will not have to be tested again until the year 20241. However, the average seepage rate for Lagoon 3 appears to exceed the allowable seepage rate of 0.25 in/day which means the potential source for the excessive leakage should be investigated further.« less

Groundwater-driven nutrient inputs to coastal lagoons: The relevance of lagoon water recirculation as a conveyor of dissolved nutrients.

PubMed

Rodellas, Valentí; Stieglitz, Thomas C; Andrisoa, Aladin; Cook, Peter G; Raimbault, Patrick; Tamborski, Joseph J; van Beek, Pieter; Radakovitch, Olivier

2018-06-16

Evaluating the sources of nutrient inputs to coastal lagoons is required to understand the functioning of these ecosystems and their vulnerability to eutrophication. Whereas terrestrial groundwater processes are increasingly recognized as relevant sources of nutrients to coastal lagoons, there are still limited studies evaluating separately nutrient fluxes driven by terrestrial groundwater discharge and lagoon water recirculation through sediments. In this study, we assess the relative significance of these sources in conveying dissolved inorganic nutrients (NO 3 - , NH 4 + and PO 4 3- ) to a coastal lagoon (La Palme lagoon; France, Mediterranean Sea) using concurrent water and radon mass balances. The recirculation of lagoon water through sediments represents a source of NH 4 + (1900-5500 mol d -1 ) and PO 4 3- (22-71 mol d -1 ), but acts as a sink of NO 3 - . Estimated karstic groundwater-driven inputs of NO 3 - , NH 4 + and PO 4 3- to the lagoon are on the order of 200-1200, 1-12 and 1.5-8.7 mol d -1 , respectively. A comparison between the main nutrient sources to the lagoon (karstic groundwater, recirculation, diffusion from sediments, inputs from a sewage treatment plant and atmospheric deposition) reveals that the recirculation of lagoon water through sediments is the main source of both dissolved inorganic nitrogen (DIN) and phosphorous (DIP) to La Palme lagoon. These results are in contrast with several studies conducted in systems influenced by terrestrial groundwater inputs, where groundwater is often assumed to be the main pathway for dissolved inorganic nutrient loads. This work highlights the important role of lagoon water recirculation through permeable sediments as a major conveyor of dissolved nutrients to coastal lagoons and, thus, the need for a sound understanding of the recirculation-driven nutrient fluxes and their ecological implications to sustainably manage lagoonal ecosystems. Copyright © 2018. Published by Elsevier B.V.

How Terrorism Affects Attitudes toward Democracy: Tunisia in 2015.

PubMed

Andersen, Robert; Brym, Robert

2017-11-01

Tunisia is the only country that emerged from the Arab Spring as a democracy. However, Tunisian democracy is threatened by political divisions, economic problems, and the threat of terrorist attacks. We shed light on Tunisia's democratic prospects by examining (1) the degree to which major terrorist attacks in 2015 influenced Tunisian public opinion on democracy and (2) the extent to which preference for a democratic system affected opinions on the prospects for democracy in Tunisia. We use data from three waves of a nationwide survey conducted just before and just after Tunisia's first major terrorist attack, and just after the country's second major terrorist attack. We demonstrate that after the attacks the Tunisian public became less favourable toward democracy and less optimistic that Tunisia would soon be ready for it. Such scepticism was widespread, affecting people who preferred democracy as much as those who did not. We conclude that the prospects for Tunisian democracy are more precarious than is sometimes assumed. © 2017 Canadian Sociological Association/La Société canadienne de sociologie.

Tertiary oil discoveries whet explorer interest off Tunisia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Long, M.

Prospects for increased Tertiary oil production in the S. Mediterranean have brightened with discoveries off Tunisia, but more evaluation is needed before commercial potential is known. Several groups of U.S. and European companies have tested oil in the relatively unexplored Miocene in the Gulf of Hannamet. These include groups operated by Buttes Resources Tunisia, Elf-Aquitaine Tunisia, and Shell Tunirex. Oil test rates of 1,790 to 1,800 bpd have been reported by the Buttes group in 2 Gulf of Hammamet wells. The initial discovery probably was the first Tertiary oil ever tested in that part of the Mediterranean. The discoveries havemore » helped boost exploratory interest in the northern waters of Tunisia and northeast toward Sicily. There are reports more U.S. and European companies are requesting exploration permits from the government of Tunisia. Companies with permits are planning new exploration for 1978. Probably the most significant discovery to date has been the Buttes group's 1 Jasmine (2 BGH). The group tested high-quality 39.5'-gravity oil at a rate of 1,790 bpd. Test flow was from the Sabri Sand at 6,490 to 6,590 ft. The well was drilled in 458 ft of water.« less

Season of birth and multiple sclerosis in Tunisia.

PubMed

Sidhom, Youssef; Kacem, Imen; Bayoudh, Lamia; Ben Djebara, Mouna; Hizem, Yosr; Ben Abdelfettah, Sami; Gargouri, Amina; Gouider, Riadh

2015-11-01

Recent studies on date of birth of multiple sclerosis (MS) patients showed an association between month of birth and the risk of developing MS. This association has not been investigated in an African country. We aimed to determine if the risk of MS is associated with month of birth in Tunisia. Data concerning date of birth for MS patients in Tunisia (n = 1912) was obtained. Birth rates of MS patients were compared with all births in Tunisia matched by year of birth (n = 11,615,912). We used a chi-squared analysis and the Hewitt's non-parametric test for seasonality. The distribution of births among MS patients compared with the control population was not different when tested by the chi-squared test. The Hewitt's test for seasonality showed an excess of births between May and October among MS patients (p = 0.03). The peak of Births of MS patients in Tunisia was in July and the nadir in December. Our data does support the seasonality hypothesis of month of birth as risk factor for MS in Tunisia. Low vitamin D levels during pregnancy could be a possible explanation that needs further investigation. Copyright © 2015 Elsevier B.V. All rights reserved.

Are coastal lagoons physically or biologically controlled ecosystems? Revisiting r vs. K strategies in coastal lagoons and estuaries

NASA Astrophysics Data System (ADS)

Pérez-Ruzafa, Angel; Marcos, Concepción; Pérez-Ruzafa, Isabel María; Pérez-Marcos, María

2013-11-01

Environmental stress influences biological assemblages, with species responding to stress by adopting particular life-history strategies (e.g., r vs. K). Coastal lagoons and estuaries are considered naturally stressed and physically controlled systems with frequent environmental disturbances and fluctuations. At the same time, their transitional nature (between terrestrial, freshwater and marine) makes them especially vulnerable to human impacts and land and freshwater inputs. As a result, it is hypothesised that residents of coastal lagoons would display characteristics of r-selected species. The r-strategy involves increased reproductive effort through early reproduction, small and numerous offspring with a large dispersive capability, short lifespan and small adult body size. Together, these traits provide a selective advantage in such unpredictable or short-lived environments. Alternatively, immigrants to coastal lagoons should mostly be K-strategists, with a competitive advantage over the r-strategists, at least on a temporary time scale. These hypotheses were explored using a dataset from 73 Atlanto-Mediterranean sites: 27 estuaries, 42 coastal lagoons and 4 from the sea, obtained from published sources. A detailed analysis of the distributions of the different resident fish species according to lagoon characteristics indicated that in lagoons with a higher marine influence the families Gobiidae, Blenniidae and Syngnathidae were common, while lagoons with freshwater influence are characterized by Cyprinidae and other freshwater species. In analyzing the biological strategies of lagoon species we found that fish assemblages inhabiting marine influenced lagoons were characterized by solitary, necto-benthonic sedentary species. These species are often hermaphroditic, with benthic broods and many exhibit brooding behaviour. This suggests that marine influenced lagoons are dominated by K-strategist species, while r-strategy species will be more common in

Evaluation of sediment contamination by monoaromatic hydrocarbons in the coastal lagoons of Gulf of Saros, NE Aegean Sea.

PubMed

Ünlü, Selma; Alpar, Bedri

2017-05-15

The concentrations and distribution of monoaromatic hydrocarbons (benzene, toluene, ethyl benzene and the sum of m-, p- and o-, xylenes) were determined in the sediments of coastal lagoons of the Gulf of Saros, using a static headspace GC-MS. The total concentrations of BTEX compounds ranged from 368.5 to below detection limit 0.6μgkg -1 dw, with a mean value of 61.5μgkg -1 dw. The light aromatic fraction of m-, p-xylene was the most abundant compound (57.1% in average), and followed by toluene (38.1%)>ethylbenzene (4.1%)>o-xylene (2.5%)>benzene (1.1%). The factor analysis indicated that the levels and distribution of BTEX compounds depend on the type of contaminant source (mobile/point), absorbance of compounds in sediment, and mobility of benzene compound and degradation processes. Point sources are mainly related to agricultural facilities and port activities while the dispersion of compounds are related with their solubility, volatility and effect of sea/saline waters on lagoons. Copyright © 2017. Published by Elsevier Ltd.

West Nile virus in Tunisia, 2014: First isolation from mosquitoes.

PubMed

Wasfi, F; Dachraoui, K; Cherni, S; Bosworth, A; Barhoumi, W; Dowall, S; Chelbi, I; Derbali, M; Zoghlami, Z; Beier, J C; Zhioua, E

2016-07-01

Several outbreaks of human West Nile virus (WNV) infections were reported in Tunisia during the last two decades. Serological studies on humans as well as on equine showed intensive circulation of WNV in Tunisia. However, no virus screening of mosquitoes for WNV has been performed in Tunisia. In the present study, we collected mosquito samples from Central Tunisia to be examined for the presence of flaviviruses. A total of 102 Culex pipiens mosquitoes were collected in September 2014 from Central Tunisia. Mosquitoes were pooled according to the collection site, date and sex with a maximum of 5 specimens per pool and tested for the presence of flaviviruses by conventional reverse transcription heminested PCR and by a specific West Nile virus real time reverse transcription PCR. Of a total of 21 pools tested, 7 were positive for WNV and no other flavivirus could be evidenced in mosquito pools. In addition, WNV was isolated on Vero cells. Phylogenetic analysis showed that recent Tunisian WNV strains belong to lineage 1 WNV and are closely related to the Tunisian strain 1997 (PAH 001). This is the first detection and isolation of WNV from mosquitoes in Tunisia. Some areas of Tunisia are at high risk for human WNV infections. WNV is likely to cause future sporadic and foreseeable outbreaks. Therefore, it is of major epidemiological importance to set up an entomological surveillance as an early alert system. Timely detection of WNV should prompt vector control to prevent future outbreaks. In addition, education of people to protect themselves from mosquito bites is of major epidemiological importance as preventive measure against WNV infection. Copyright © 2016 Elsevier B.V. All rights reserved.

Aerated Lagoons. Student Manual. Biological Treatment Process Control.

ERIC Educational Resources Information Center

Andersen, Lorri

This student manual contains the textual material for a unit which focuses on the structural and operationally unique features of aerated lagoons. Topic areas discussed include: (1) characteristics of completely mixed aerated lagoons; (2) facultative aerated lagoons; (3) aerated oxidation ponds; (4) effects of temperature on aerated lagoons; (5)…

Multi-centennial scale precipitation and following lagoon ecosystem fluctuation in the Holocene reconstructed by East Korean Lagoon sediment analysis

NASA Astrophysics Data System (ADS)

Katsuki, K.; Yang, D. Y.; Lim, J.; Nahm, W. H.; Nakanishi, T.; Seto, K.; Otsuka, M.; Kashima, K.

2014-12-01

There are lagoons in the northern east coast of the South Korea, which were formed during the transgression period in the early Holocene. These lagoons shrank about 5-30 % during the first half of 20 century due to terrestrial sediment input from soil erosion in reclamation lands. However, buried lagoonal sediments record Holocene climate change. In this study, multi-centennial scale paleo-climate and paleo-ecosystem change were investigated by analysis of this buried and present lagoon deposits. Based on the diatom assemblage analysis of the sediment in the lagoon Maeho where it is the east coast lagoons in Korea, this lagoon was formed about 8,400 years ago, and halophilic diatoms showed high peaks at three times within the last 8,400 years. Timings of these peaks were well coincident with the high-sea level periods reported in the western Japan. It is considered that sea-level of the east coast in Korea also showed high at three times during the mid-late Holocene, and then, salinity of the lagoon increased in these periods. Except for such sea-level dependent change, salinity of the lagoon Maeho showed the multi-centennial (200 or 400 years) scale periodic variation. Magnetic susceptibility (MS) also showed the clear 400 years periodicity in the mid-late Holocene. When the MS showed high value, oligohalobous diatoms showed high value. However, halophilic diatoms and number of total diatom valves increased when the MS showed low value. This correspondence probably indicates that magnetic minerals flew into the lagoon with river fresh water, and then volume of fresh water inflow has changed with 400 years cycles. Such MS cycle was also confirmed in the sediments of other lagoons. Change of fresh water inflow should be not local event, was a part of regional environmental change. These results probably indicate that the precipitation on the northeastern South Korea has changed by the 400 years cycle. On the basis of lagoon bottom sediment, it made clear that the

First genotype identification of Trichosporon asahii in Sfax, Tunisia.

PubMed

Sellami, Hayet; Trabelsi, Houaida; Neji, Sourour; Amouri, Imen; Cheikhrouhou, Fatma; Makni, Fattouma; Ayadi, Ali

2017-04-01

The objectives of our study were species identification and genotyping of Trichosporon isolates collected at the Parasitology and Mycology Laboratory in Sfax, Tunisia. Molecular identification was carried out by analysing the IGS1 regions of the rDNA of 30 Trichosporon isolates. Trichosporon asahii was the most frequent species detected. Furthermore, four genotypes were identified in Tunisia: 1 (46.4 %), 4 (35.7 %), 7 (14.3 %) and 3 (3.6 %). In vitro antifungal susceptibility testing of the isolates showed that voriconazole exhibited the highest activity. This is the first reported study of genotype identification of T. asahii in Tunisia and even in the African continent.

Natural infection of Ctenodactylus gundi by Leishmania major in Tunisia.

PubMed

Ghawar, Wissem; Bettaieb, Jihène; Salem, Sadok; Snoussi, Mohammed-Ali; Jaouadi, Kaouther; Yazidi, Rihab; Ben-Salah, Afif

2018-01-01

Incriminating new rodent species, as reservoir hosts of Leishmania parasites is crucial for understanding the transmission cycle of cutaneous leishmaniasis in Tunisia. Ctenodactylus (C.) gundi was previously described as extremely abundant in all Tunisian Leishmania (L.) tropica foci in south Tunisia besides its presence in L. major endemic area. The aim of this study was to detect Leishmania species parasites among C. gundi in two endemic regions in Tunisia: Sidi Bouzid and Tataouine. Total DNA was isolated from the spleens and the livers of 92C. gundi. Leishmaniasis clinical manifestations were detected among 11 rodents (12%). Leishmania parasites were detected in 30 (32.6%) rodents using direct exam method. Leishmania DNA was detected in 40 (43.5%) C. gundi by combining results among spleens and livers using ITS1-PCR. Positive samples were confirmed to be L. major except for only one specimen which was L. tropica. These results demonstrated, for the first time, the high natural infection rate of C. gundi with L. major parasites in Tunisia. Hence, C. gundi should be considered as potential reservoir host of Leishmania parasites causing cutaneous leishmaniasis in Tunisia. Copyright © 2017. Published by Elsevier B.V.

Flushing of a coastal lagoon in the Red Sea

NASA Astrophysics Data System (ADS)

Sultan, S. A. R.; Ahmad, F.

1990-09-01

Shu'aiba Lagoon (Lat. 20°45'N; Long. 39°28'E) is located on the eastern coast of the Red Sea. It is relatively shallow with an area of approximately 11·7 km 2. The inlet to the lagoon is narrow with a cross-sectional area of about 245 m 2. This lagoon is a future site to develop mariculture. With this objective in view the flushing time scale of the lagoon was calculated, as flushing is an important abiotic factor in lagoon ecology. The average flushing time for the months February to June and September to November is about 20 days. Oceanic inputs play an important part in the process of fertilization of the lagoons. The marine environment in arid zone lagoons is under natural stress due to high temperatures and salinities. However, the flushing time scale of 20 days may not exert intolerable stress on the ecology of the Shu'aiba Lagoon.

[Urbanization and its consequences for socio-demographic structures in Tunisia].

PubMed

Taamallah, M

1986-01-01

Comparisons are made between rural and urban populations in Tunisia in terms of selected demographic and social factors using official and other published data for the late 1970s and early 1980s. The focus is on the consequences of imbalances created by Tunisia's urbanization for population composition, health, economic development, and certain social structures. The history of urbanization in Tunisia since the end of the nineteenth century is outlined. Urban and rural populations are compared on the basis of sex distribution, age distribution, mortality, and fertility. The relationships among urbanization and economic development, public health, and family structure are considered.

Dust Streams from Tunisia

NASA Technical Reports Server (NTRS)

2002-01-01

On October 6, 2001, the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) captured this true-color image of a large dust storm blowing northeastward across the Mediterranean Sea from Tunisia. According to Joseph Prospero, professor of atmospheric science at the University of Miami, there is an unusual arc-shaped 'front' to the dust cloud. The storm's shape suggests that the source of the dust is rather small and that the meteorology driving it rather unusual. The dust seems to be coming out of the wadis, dry lakebeds and riverbeds, at the base of the Tell Atlas Mountains in northern Tunisia and eastern Algeria. The dust appears to be blowing toward the island of Sicily, Italy (toward the upper righthand corner). Also notice there is a relatively thin plume of smoke emanating eastward from the top of Mount Etna on Sicily. Image courtesy the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

The present environmental scenario of the Nador Lagoon (Morocco).

PubMed

Ruiz, F; Abad, M; Olías, M; Galán, E; González, I; Aguilá, E; Hamoumi, N; Pulido, I; Cantano, M

2006-10-01

In this paper, we present a multivariate approach (waters, sediments, microfauna) concerning the environmental state of the Nador Lagoon (NE Morocco). The normal water quality parameters (salinity, pH, nutrients) of the dominant marine flows are altered by local fecal water effluents, urban discharges, sewages derived from a water treatment station, and residues originated in a slaughterhouse. The geochemical analyses carried out in surficial sediment samples show very high concentrations of all metals studied near an old iron mine and moderate contents between Nador and its treatment station. Ostracods are good bioindicators of these environmental impacts, with the presence of a highly brackish assemblage in the quieter, more confined areas or the appearance of opportunistic species under hypoxic conditions. In addition, these microcrustaceans are absent in polluted bottom sediments or areas with high hydrodynamic gradients, whereas they decrease in both density and diversity if the subaerial exposure increases.

The Language Situation in Tunisia.

ERIC Educational Resources Information Center

Daoud, Mohamed

2001-01-01

Describes the current language situation in Tunisia while maintaining a historical perspective that is helpful in understanding how language-related changes have come about, and a prospective view that may illuminate future developments. (Author/VWL)

Lateral extrusion of Tunisia : Contribution of Jeffara Fault (southern branch) and Petroleum Implications

NASA Astrophysics Data System (ADS)

Ghedhoui, R.; Deffontaines, B.; Rabia, M. C.

2012-04-01

to the tectonic accident, located in the south of the Tunisian extrusion, in favour of the eastern migration of the Sahel block toward the free Mediterranean sea boundary. Therefore this geodynamic movement explains the presence, in offshore area, of small elongated NW-SE, N-S &NE-SW petroleum transtensive basins and grabens. To conclude, at the regional scale, the structural geomorphologic approach combined with both field work and reflexion seismic profile analyses appear to be an excellent tool to prove & confirm the east Sahel block extrusion of the central Tunisian part caused by the northward migration of African plate. _______________________________________ Keywords : Geodynamics, Neotectonics, right lateral transtensive fault, Extrusion, Petroleum exploration, Geomorphometry, Digital Elevation Model, Geographic Information System (GIS), Geodatabase, Jeffara, South Tunisia.

Inverse-dispersion technique for assessing lagoon gas emissions

USDA-ARS?s Scientific Manuscript database

Measuring gas emissions from treatment lagoons and storage ponds poses challenging conditions for existing micrometeorological techniques because of non-ideal wind conditions, such as those induced by trees and crops surrounding the lagoons, and lagoons with dimensions too small to establish equilib...

Genetic Diversity of HIV-1 in Tunisia.

PubMed

El Moussi, Awatef; Thomson, Michael M; Delgado, Elena; Cuevas, María Teresa; Nasr, Majda; Abid, Salma; Ben Hadj Kacem, Mohamed Ali; Benaissa Tiouiri, Hanene; Letaief, Amel; Chakroun, Mohamed; Ben Jemaa, Mounir; Hamdouni, Hayet; Tej Dellagi, Rafla; Kheireddine, Khaled; Boutiba, Ilhem; Pérez-Álvarez, Lucía; Slim, Amine

2017-01-01

In this study, the genetic diversity of HIV-1 in Tunisia was analyzed. For this, 193 samples were collected in different regions of Tunisia between 2012 and 2015. A protease and reverse transcriptase fragment were amplified and sequenced. Phylogenetic analyses were performed through maximum likelihood and recombination was analyzed by bootscanning. Six HIV-1 subtypes (B, A1, G, D, C, and F2), 5 circulating recombinant forms (CRF02_AG, CRF25_cpx, CRF43_02G, CRF06_cpx, and CRF19_cpx), and 11 unique recombinant forms were identified. Subtype B (46.4%) and CRF02_AG (39.4%) were the predominant genetic forms. A group of 44 CRF02_AG sequences formed a distinct Tunisian cluster, which also included four viruses from western Europe. Nine viruses were closely related to isolates collected in other African or in European countries. In conclusion, a high HIV-1 genetic diversity is observed in Tunisia and the local spread of CRF02_AG is first documented in this country.

Mercury Concentrations in Coastal Sediment from Younger Lagoon, Central California

NASA Astrophysics Data System (ADS)

Hohn, R. A.; Ganguli, P. M.; Swarzenski, P. W.; Richardson, C. M.; Merckling, J.; Johnson, C.; Flegal, A. R.

2013-12-01

Younger Lagoon Reserve, located in northern Monterey Bay, is one of the few relatively undisturbed wetlands that remain along the Central Coast of California. This lagoon system provides protected habitat for more than 100 bird species and for populations of fish, mammals, and invertebrates. Total mercury (HgT) concentrations in water within Younger Lagoon appear to vary with rainfall conditions and range from about 5-15 pM. These concentrations are similar to HgT in water from six nearby lagoon systems. However, Younger Lagoon contains elevated concentrations of dissolved organic carbon (~1 mM) and monomethylmercury (MMHg, ~1 pM) relative to our comparison lagoon sites (DOC < 0.5 mM and MMHg < 0.5 pM). We attribute Younger Lagoon's high DOC and MMHg to its restricted connection to the ocean and minor riverine contribution. Coastal lagoons in this region typically form at the mouth of streams. They behave as small estuaries during the wet season when surface water discharge keeps the mouth of the stream open to the ocean, and then transition into lagoons in the dry season when a sand berm develops and effectively cuts off surface water exchange. At Younger Lagoon, the sand berm remains intact throughout the year, breaching only during particularly high tides or intense rain events. Therefore, the lagoon's connection to nearshore seawater is primarily via surface water - groundwater interaction through the sand berm. Because Younger Lagoon is largely isolated from a surface water connection with the ocean, runoff from upgradient urban and agricultural land has an enhanced impact on water (and presumably sediment) quality. As a result, the lagoon is eutrophic and experiences annual algal blooms. Groundwater surveys suggest surface water, groundwater, and coastal seawater are hydraulically connected at Younger Lagoon, and mixing among these water masses appears to influence water geochemistry. To date, no chemical analyses have been conducted on sediment from Younger

Facultative Lagoons. Student Manual. Biological Treatment Process Control.

ERIC Educational Resources Information Center

Andersen, Lorri

The textual material for a unit on facultative lagoons is presented in this student manual. Topic areas discussed include: (1) loading; (2) microbial theory; (3) structure and design; (4) process control; (5) lagoon start-up; (6) data handling and analysis; (7) lagoon maintenance (considering visual observations, pond structure, safety, odor,…

Preliminary study of plants used in ethnoveterinary medicine in Tunisia and in Italy.

PubMed

Viegi, Lucia; Ghedira, Kamel

2014-01-01

A survey relative to the use of plants for the cure of animals in Tunisia was conducted in order to make a comparison with the same species (or similar ones) in central and southern Italy. available bibliographical data both for Italy and for Tunisia were consulted. Thirty-nine plants, representing 22 families, used in Tunisia in ethnoveterinary medicine were reported, and comparisons made with close species used in Central and Southern Italy. Seven of the 39 species (about the 18% of the total) are not present in Italian flora. Fourteen of the 39 species (35% of the total) are also used in Italy. Camelidae (dromedaries and camels) are the most valuable types of domestic animals cured in Tunisia, but ovines, horses, bulls, dogs are also treated. Some uses coincide with those existing in different Italian regions. The plants used are the most common and most easily found in these areas. The present study confirms the convergence in ethnoveterinary medicine between Tunisia and Italy, even if it appears less significant than in human ethnobotany. Further studies are required in areas of Tunisia that have not yet been studied, in order to get the possibility of an evaluation of active compounds.

A Century of changes for Razelm-Sinoe Lagoon System

NASA Astrophysics Data System (ADS)

Scrieciu, Marian-Albert; Stanica, Adrian

2014-05-01

A Century of changes for Razelm-Sinoe Lagoon System Marian-Albert Scrieciu (a), Adrian Stanica (a) (a) National Institute of Marine Geology and Geoecology e GeoEcoMar, Str. Dimitrie Onciul 23e25, Sector 2, 024053 Bucharest, Romania Razelm-Sinoe Lagoon System, situated in the NW part of the Black Sea, in tight connection with the Danube Delta, has been subject to major changes due to human interventions in the past century. These changes have resulted into a complete change of the Lagoon specific ecosystems compared to its pristine state. In its natural state, as brackish - transitional environment, Antipa (1894) mentions Razelm Lagoon as one of the places with the greatest fisheries around the Black Sea coast (about 1879 - 1884, there were approximately 10,000 fishermen, all working on the Razelm Sinoe Lagoon System). Starting with the end of the XIXth Century, new canals were dug and existing channels were dredged in order to develop tighter connections with the Danube River. The natural inlet of Portita was blocked four decades ago and connections between the various parts of the lagoon system were controlled by the building of locks and sluices. The 2 inlets of Sinoe Lagoon were also controlled during early 1980s. Under these conditions, the lagoon ecosystem changed from brackish towards freshwater, with major effects on the existing flora and fauna. The period of brutal interventions ended in 1989 and the Razelm-Sinoe Lagoon System became part of the Danube Delta Biosphere Reserve in 1991, with a strict policy of nature protection and restoration. Spatial planning has been the major management option for the entire reserve, lagoon system included. Plans for sustainable development of the Razelm-Sinoe Lagoon System have been built in a participative manner, involving the local stakeholders, as part of FP7 ARCH project. Special attention has been given to impacts of climate change. The study presents the vision for the development Razelm-Sinoe Lagoon System over

Lagoonal deposits in the Upper Cretaceous Rock Springs Formation (Mesaverde Group), southwest Wyoming

USGS Publications Warehouse

Kirschbaum, M.A.

1989-01-01

Most paleogeographic reconstructions of the Rock Springs Formation show shorelines having lobate to arcuate deltas. These shorelines are oriented NE-SW, with the sea to the southeast. Brackish-water bodies are usually shown in interdistributary areas or associated with abandoned delta lobes, and are open to the sea. In this study, a sedimentary sequence 30-50 m thick is interpreted as interdeltaic deposits. Brackish-water deposits within the sequence are interpreted as interdeltaic lagoons rather than interdistributary bays. Three facies associations (units) are recognized in nine measured sections of the study interval. Unit A consists of interbedded sandstone, mudrock and coal which occur in both fining- and coarsening-upward sequences less than 10 m thick. Fining-upward sequences decrease in thickness and frequency upwards in unit A and are interpreted as distributary channels. Coarsening-upward sequences associated with the channels are interpreted as crevasse splays that filled lakes or interdistributary bays. In the upper part of the unit where only minor channels are present, the coarsening-upward sequences are interpreted as bay deltas. Unit B consists of fossiliferous silty shale and bioturbated sandy siltstone. A low-diversity fauna of bivalves, gastropods, ostracods and foraminifers indicates that brackish-water conditions existed. Unit B intertongues with unit A to the northwest and with unit C to the southeast, and is interpreted as lagoonal deposits. Unit C consists of crossbedded and burrowed sandstone in beds 0.5-9 m thick. Sandstones are laterally continuous in the southeast but become tabular bodies enclosed within unit B to the northwest. Laterally continuous sandstones are interpreted as shoreface deposits on the basis of multidirectional crossbeds, marine trace fossils and continuity. Tabular sandstones are interpreted as flood-tidal deltas on the basis of NW-oriented crossbeds, pinchouts to the northwest and enclosure within unit B. Scoured

Santa Margarita Lagoon Water Quality Monitoring Data

DTIC Science & Technology

2012-08-01

sits entirely within the boundaries of Marine Corps Base Camp Pendleton. It forms up where the Santa Margarita River meets the Pacific Ocean just north...of Oceanside, California. The western boundary of the lagoon is the beach berm that borders the ocean . The estuarine lagoon is usually open to the... ocean through a limited section of berm, although there are occasions when the lagoon is effectively closed to exchange with the ocean . The eastern

Clinical surveillance for human astrovirus in Monastir region, Tunisia.

PubMed

Monastiri, Abir; Aouni, Mahjoub; Guix, Susana; Mechri, Badereddine; Lopez-Roig, Marc; Abid, Nabil Ben Salem; Gueddiche, Neji; Hamami, Sabeur; Boughzala, Lamjed; Serra-Cobo, Jordi

2016-01-21

Astroviruses (AstVs) are enteric viruses that can cause gastroenteritis in children. This study is part of monitoring the circulation of astroviruses in children hospitalized and/or outpatients for acute gastroenteritis at the primary care center of Ouerdanine or at the Pediatric Department of the University Hospital Fattouma-Bourguiba (Monastir, Tunisia). The aims of our study were to know the prevalence of human astrovirus in clinical samples of children, characterize the strains and evaluate the infectivity of isolated strains on cell culture. Fifty stool samples were collected from children under five years old in the region of Monastir (Tunisia) from October 2010 to June 2011. All specimens were subjected to RT-PCR amplification followed by sequencing and phylogenetic analysis. The study shows a low prevalence of astrovirus (4 %) in children. The two positive samples obtained were HAstV type 3. Samples that were RT-PCR positive were cultured in CaCO-2 cells and the presence of infectious viral particles was confirmed. The phylogenetic analysis shows that the different HAstV-3 strains isolated in Tunisia are grouped into two clusters. The first cluster includes strains obtained in 2004, which belong to lineage HAstV-3a, while strains isolated in 2010 belong to lineage HAstV-3c. This study is part of monitoring the circulation of astroviruses in children younger than five years old from Monastir region, Tunisia. The results show low prevalence (4 %). All genotyped samples belonged to lineage HAstV-3c, which could be presently emerging. Two different lineages have been isolated in Tunisia: HAstV-3a in 2004 and HAstV-3c in 2010.

Registration of NE Trailblazer C-1, NE Trailblazer C0, NE Trailblazer C2, NE Trailblazer C3, NE Trailblazer C4, and NE Trailblazer C5 Switchgrass Germplasms

USDA-ARS?s Scientific Manuscript database

NE Trailblazer C-1 (GP-101, PI 672015), NE Trailblazer C0 (GP-100, PI 672014), NE Trailblazer C2 (GP-102, PI 672016), NE Trailblazer C3 (GP-103, PI 672017), NE Trailblazer C4 (GP-104, PI 672018), and NE Trailblazer C5 (GP-105, PI 672019) switchgrass (Panicum virgatum L.) germplasms were released by ...

Scottish saline lagoons: Impacts and challenges of climate change

NASA Astrophysics Data System (ADS)

Angus, Stewart

2017-11-01

The majority of Scotland's saline lagoons are located on the low-lying coastlines of the Western Isles and the northern archipelagos of Orkney and Shetland, where recorded annual relative sea level rise rates are among the highest in Scotland. The sediment-impounded lagoons of Orkney and Shetland will either lose their impoundment and become incorporated in marine coastal waters, or become increasingly saline, as relative sea levels rise. The rock-basin lagoons of the Western Isles will retain their restricted exchange with the sea but will also become more saline with rising sea level. Specialist lagoonal organisms tend to have wide salinity tolerances but may succumb to competition from marine counterparts. In all areas, there are sufficient fresh-water inland water bodies with potential to be captured as lagoons to compensate for loss of extent and number, but the specialist lagoon biota tend to have limited dispersal powers. It is thus possible that they will be unable to transfer to their analogue sites before existing lagoons become fully marine, giving conservation managers the problem of deciding on management options: leave natural processes to operate without interference, manage the saline inflow to maintain the current salinity regime, or translocate lagoon organisms perceived as threatened by rising salinities. Timing of conversion and capture is unpredictable due to local topography and complications caused by variable stratification.

The effect of lagoons on Adriatic Sea tidal dynamics

NASA Astrophysics Data System (ADS)

Ferrarin, Christian; Maicu, Francesco; Umgiesser, Georg

2017-11-01

In this study the effects that lagoons exert on the barotropic tidal dynamics of a regional sea, the Adriatic Sea, were numerically explored. This semi-enclosed basin is one of the places with the highest tidal range in the Mediterranean Sea and is characterised by the presence of several lagoons in its northern part. The tidal dynamics of a system comprising the whole Adriatic Sea and the lagoons of Venice, Marano-Grado and Po Delta were investigated using an unstructured hydrodynamic model. Numerical experiments with and without lagoons reveal that even if the considered shallow water bodies represent only the 0.5 and 0.002% of the Adriatic Sea surface and volume, respectively, they significantly affect the entire Northern Adriatic Sea tidal dynamics by enhancing tidal range (by 5%) and currents (by 10%). The inclusion of lagoons in the computation improved the model performance by 25% in reproducing tidal constituents in the Adriatic Sea. The back-effect of the lagoons on the open-sea tide is due to the waves radiating from the co-oscillating lagoons into the adjacent sea. This is the first time these processes are shown to be relevant for the Adriatic Sea, thus enhancing the understanding of the tidal dynamics in this regional sea. These findings may also apply to other coastal seas with connections to lagoons, bays and estuaries.

Blood meal analysis of culicoides (Diptera: ceratopogonidae) in central Tunisia.

PubMed

Slama, Darine; Haouas, Najoua; Mezhoud, Habib; Babba, Hamouda; Chaker, Emna

2015-01-01

To evaluate the host preferences of Culicoides species (Diptera: Ceratopogonidae) in Central Tunisia, we identified the source of blood meals of field collected specimens by sequencing of the cytochrome b (cyt b) mitochondrial locus and Prepronociceptine single copy nuclear gene. The study includes the most common and abundant livestock associated species of biting midges in Tunisia: C. imicola, C. jumineri, C. newsteadi, C. paolae, C. cataneii, C. circumscriptus, C. kingi, C. pseudojumineri, C. submaritimus, C. langeroni, C. jumineri var and some unidentified C. species. Analysis of cyt b PCR products from 182 field collected blood-engorged females' midges revealed that 92% of them fed solely on mammalian species, 1.6% on birds, 2.4% on insects and 0.8% on reptiles. The blast results identified the blood origin of biting midges to the species level with exact or nearly exact matches (≥98%). The results confirm the presence of several Culicoides species, including proven vectors in Central Tunisia. Blood meal analyses show that these species will indeed feed on bigger mammals, thereby highlighting the risk that these viruses will be able to spread in Tunisia.

Blood Meal Analysis of Culicoides (Diptera: Ceratopogonidae) in Central Tunisia

PubMed Central

Slama, Darine; Haouas, Najoua; Mezhoud, Habib; Babba, Hamouda; Chaker, Emna

2015-01-01

To evaluate the host preferences of Culicoides species (Diptera: Ceratopogonidae) in Central Tunisia, we identified the source of blood meals of field collected specimens by sequencing of the cytochrome b (cyt b) mitochondrial locus and Prepronociceptine single copy nuclear gene. The study includes the most common and abundant livestock associated species of biting midges in Tunisia: C. imicola, C. jumineri, C. newsteadi, C. paolae, C. cataneii, C. circumscriptus, C. kingi, C. pseudojumineri, C. submaritimus, C. langeroni, C. jumineri var and some unidentified C. species. Analysis of cyt b PCR products from 182 field collected blood-engorged females’ midges revealed that 92% of them fed solely on mammalian species, 1.6% on birds, 2.4% on insects and 0.8% on reptiles. The blast results identified the blood origin of biting midges to the species level with exact or nearly exact matches (≥98%). The results confirm the presence of several Culicoides species, including proven vectors in Central Tunisia. Blood meal analyses show that these species will indeed feed on bigger mammals, thereby highlighting the risk that these viruses will be able to spread in Tunisia. PMID:25793285

Biomarker responses and contamination levels in crabs (Carcinus aestuarii) from the Lagoon of Venice: An integrated approach in biomonitoring estuarine environments.

PubMed

Ricciardi, Francesco; Matozzo, Valerio; Binelli, Andrea; Marin, Maria Gabriella

2010-03-01

An integrated biological-chemical approach is necessary to evaluate correctly the environmental status of bodies of water, as suggested by the EU Water Framework Directive. The shore crab Carcinus aestuarii, sampled in the Lagoon of Venice (NE Italy), was used as a biomonitor species, and the chemical concentrations of 42 organic pollutants (HCHs, PAHs, PCBs, DDTs, PBDEs), biological responses related to neurotoxicity (AChE inhibition), detoxification mechanisms (CYP450 induction) and endocrine alterations (vitellogenin-like protein induction) were measured at the same time. The responsiveness of biomarkers as predictors (or descriptors) of chemical contamination was evaluated by multivariate regression analysis, revealing good predictor potential for the selected biomarkers. Biomonitoring in the Lagoon of Venice revealed a predominance of DDT and PCB compounds, especially near industrial sites or large cities. Endocrine alterations, not always correlated with the presence of measured compounds, were also detected in many areas, suggesting exposure to compounds able to interfere with the crab endocrine system. Copyright 2009 Elsevier Ltd. All rights reserved.

Nutrient-Chlorophyll Relationships in the Indian River Lagoon, Florida

EPA Science Inventory

The Indian River Lagoon is a highly diverse estuary located along Florida’s Atlantic coast. The system is made up of the main stem and two side-lagoons: the Banana River and Mosquito Lagoon. We segmented the main stem into three sections based on spatial trends in water quality ...

First report of naturally infected Sergentomyia minuta with Leishmania major in Tunisia.

PubMed

Jaouadi, Kaouther; Ghawar, Wissem; Salem, Sadok; Gharbi, Mohamed; Bettaieb, Jihene; Yazidi, Rihab; Harrabi, Mariem; Hamarsheh, Omar; Ben Salah, Afif

2015-12-21

Many sand fly species are implicated in the transmission cycle of Leishmania parasites around the world. Incriminating new sand flies species, as vectors of Leishmania is crucial to understanding the parasite-vector transmission cycle in different areas in Tunisia and surrounding countries. Seventy-four unfed females belonging to the genera Sergentomyia and Phlebotomus were collected in South Tunisia between June and November 2014, using sticky papers. PCR-RFLP (Restriction Fragment Length Polymorphism) analysis of the internal transcribed spacer 1 (ITS1) was used for Leishmania parasites detection and identification. Leishmania (L.) major (Yakimoff & Shokkor, 1914) was identified within two Sergentomyia (S.) minuta (Rondani, 1843) and one Phlebotomus papatasi (Scopoli, 1786). This is the first report of L. major identified from S. minuta in Tunisia. This novel finding enhances the understanding of the transmission cycle of L. major parasites of cutaneous leishmaniasis in an endemic area in South Tunisia.

New insights into the structure of Om Ali-Thelepte basin, central Tunisia, inferred from gravity data: Hydrogeological implications

NASA Astrophysics Data System (ADS)

Harchi, Mongi; Gabtni, Hakim; El Mejri, Hatem; Dassi, Lassaad; Mammou, Abdallah Ben

2016-08-01

This work presents new results from gravity data analyses and interpretation within the Om Ali-Thelepte (OAT) basin, central Tunisia. It focuses on the hydrogeological implication, using several qualitative and quantitative techniques such as horizontal gradient, upward continuation and Euler deconvolution on boreholes log data, seismic reflection data and electrical conductivity measurements. The structures highlighted using the filtering techniques suggest that the Miocene aquifer of OAT basin is cut by four major fault systems that trend E-W, NE-SW, NW-SE and NNE-SSW. In addition, a NW-SE gravity model established shows the geometry of the Miocene sandstone reservoir and the Upper Cretaceous limestone rocks. Moreover, the superimposition of the electrical conductivity and the structural maps indicates that the low conductivity values of sampled water from boreholes are located around main faults.

Benthic ecology of tropical coastal lagoons: Environmental changes over the last decades in the Términos Lagoon, Mexico

NASA Astrophysics Data System (ADS)

Grenz, Christian; Fichez, Renaud; Silva, Carlos Álvarez; Benítez, Laura Calva; Conan, Pascal; Esparza, Adolfo Contreras Ruiz; Denis, Lionel; Ruiz, Silvia Díaz; Douillet, Pascal; Martinez, Margarita E. Gallegos; Ghiglione, Jean-François; Mendieta, Francisco José Gutiérrez; Origel-Moreno, Montserrat; Garcia, Antonio Zoilo Marquez; Caravaca, Alain Muñoz; Pujo-Pay, Mireille; Alvarado, Rocío Torres; Zavala-Hidalgo, Jorge

2017-10-01

The Términos Lagoon is a 2000-km2 wide coastal lagoon linked to the largest river catchment in Mesoamerica. Economic development, together with its ecological importance, led the Mexican government to pronounce the Términos Lagoon and its surrounding wetlands as a Federal protected area for flora and fauna in 1994. It is characterized by small temperature fluctuations, but with two distinct seasons (wet and dry) that control the biological, geochemical, and physical processes and components. This paper presents a review of the available information about the Términos Lagoon. The review shows that the diversity of benthic communities is structured by the balance between marine and riverine inputs and that this structuration strongly influences the benthic metabolism and its coupling with the biogeochemistry of the water column. The paper also presents many specific drivers and recommendations for a long-term environmental survey strategy in the context of the expected Global Change in the Central American region.

Seroprevalence of Toscana virus infection in Tunisia.

PubMed

Fezaa, Ons; Bahri, Olfa; Alaya Bouafif, Nissaf Ben; Triki, Henda; Bouattour, Ali

2013-12-01

The main objective of this study was to assess the prevalence of IgG antibodies against Toscana virus (TOSV) by an ELISA test and to determine the extent of its circulation in Tunisia. An indirect ELISA test was performed to detect anti-TOSV IgG. The results were compared to those of an indirect fluorescent antibody (IFA) test. The survey tested 494 healthy people from various regions of Tunisia by ELISA for anti-TOSV IgG; 47 people (9.5%) were found to be positive. Seroprevalence varied by bioclimatic region and gender. Two hundred and twelve samples, randomly chosen from the same selected population and tested with ELISA, were retested using an IFA for IgG antibodies. An 85% concordance between the IFA and ELISA was obtained (kappa=0.650). These serological data confirm the circulation of TOSV in different bioclimatic zones in Tunisia where the vector sand flies are found. The detection of IgG against TOSV suggests that the diagnosis of TOSV infection is often neglected, as this virus often causes asymptomatic infections, with only a few patients developing severe illnesses involving neurological manifestations. Copyright © 2013 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Both riverine detritus and dissolved nutrients drive lagoon fisheries

NASA Astrophysics Data System (ADS)

Bonthu, Subbareddy; Ganguly, Dipnarayan; Ramachandran, Purvaja; Ramachandran, Ramesh; Pattnaik, Ajit K.; Wolanski, Eric

2016-12-01

The net ecosystem metabolism in lagoons has often been estimated from the net budget of dissolved nutrients. Such is the case of the LOICZ estuarine biogeochemistry nutrient budget model that considers riverine dissolved nutrients, but not riverine detritus. However the neglect of detritus can lead to inconsistencies; for instance, it results in an estimate of 5-10 times more seaward export of nutrients than there is import from rivers in Chilika Lagoon, India. To resolve that discrepancy the UNESCO estuarine ecohydrology model, that considers both dissolved nutrients and detritus, was used and, for Chilika Lagoon, it reproduced successfully the spatial distribution of salinity, dissolved nutrients, phytoplankton and zooplankton as well as the fish yield data. Thus the model suggests that the riverine input of both detritus and dissolved nutrients supports the pelagic food web. The model also reproduces well the observation of decreased fish yield when the mouth of the lagoon was choked in the 1990s, demonstrating the importance of the physics that determine the flushing rate of waterborne matter. Thus, both farming in the watershed by driving the nutrient and detritus inputs to the lagoon, and dredging and engineering management of the mouth by controlling the flushing rate of the lagoon, have a major influence on fish stocks in the lagoon.

Evaluating the human impact on groundwater quality discharging into a coastal reef lagoon

NASA Astrophysics Data System (ADS)

Rebolledo-Vieyra, M.; Hernandez-Terrones, L.; Soto, M.; Lecossec, A.; Monroy-Rios, E.

2008-12-01

The Eastern coast of the Yucatan Peninsula has the fastest growth rate in Mexico and groundwater is the only source of drinking water in the region. The consequences of the lack of proper infrastructure to collect and treat wastewater and the impact of human activities on the quality of groundwater are addressed. The groundwater in the coastal aquifer of Quintana Roo (SE Mexico) discharges directly into the ocean. In addition, the coral reef of the Eastern Yucatan Peninsula is part of the Mesoamerican Coral Reef System, one of the largest in the world. The interaction of the reef-lagoon hydraulics with the coastal aquifer of Puerto Morelos (NE Yucatan Peninsula), and a major input of NH4, SO4, SiO2, as a consequence of the use of septic tanks and the lack of modern wastewater treatment plants are presented. No seasonal parameters differences were observed, suggesting that groundwater composition reaching the reef lagoon is not changing seasonally. A conceptual model of the coastal aquifer was developed, in order to explain how the human activities are impacting directly on the groundwater quality that, potentially, will have a direct impact on the coral reef. The protection and conservation of coral reefs must be directly related with a policy of sound management of coastal aquifers and wastewater treatment.

Fish fauna recovery in a newly re-flooded Mediterranean coastal lagoon

NASA Astrophysics Data System (ADS)

Koutrakis, Emmanuil; Sylaios, Georgios; Kamidis, Nikolaos; Markou, Dimitrios; Sapounidis, Argyris

2009-08-01

Drana Lagoon, located at the NW site of Evros River Delta, was drained in 1987 and re-flooded in 2004 within the framework of an integrated wetland restoration project. This study presents the results of a monitoring program of the lagoon's oceanographic, water quality and fish fauna characteristics, during the pre- and post-restoration period. Results depict the presence of high salinity water (up to 41) due to seawater intrusion, strong evaporation in its interior and inadequate freshwater inflows. Overall, nutrient levels were low depicting local changes. Tidal variability at the mouth was approximately 0.2 m, producing high velocity tidal currents (up to 0.75 m/s). Eleven fish fauna species were collected; seven species were caught in both the inlet channel and the lagoon during the pre-restoration period and nine species in the post-restoration period. Atherina boyeri (37.6%) and Pomatoschistus marmoratus (31.7%) dominated the lagoon during the post-restoration period. Most of the A. boyeri specimens (88.5%) were caught inside the lagoon, while P. marmoratus had an almost equal distribution in the inlet channel and the lagoon (56.3% and 43.7% respectively). The presence of species of the Mugilidae family (5.2% total average catches after lagoon re-flooding) was mainly in the inlet channel (12.6% of the average catches) and not inside the lagoon (only 1.3% of the average catches). The small number of fish species inhabiting the lagoon might be the result of the recent restoration or it could be related with the increased water flow observed at the lagoon mouth during the flood and ebb tidal phases, and also in the presence of a smooth bank in the concrete waterspout that connects the entrance channel with the lagoon. The limited presence of the Mugilidae juveniles inside the lagoon could be related to the prevailing tidal inlet dynamics (i.e. strong ebb flow at lagoon inlet), thus preventing the species to enter the lagoon. In order to restore the lagoon

Vulvar cancer in Tunisia: Epidemiological and clinicopathological features multicentric study.

PubMed

Kehila, Mehdi; Harabi, Souad; Mhiri, Raoudha; Touhami, Omar; Abouda, Hassine Saber; Khlifi, Abdeljalil; Hsairi, Mohamed; Chelli, Dalenda; Derbel, Mohamed; Kebaili, Sahbi; Boujelbane, Nadia; Chaabene, Kais; Chanoufi, Mohamed Badis

2017-06-01

To describe for the first time the epidemiologic and clinico-pathologic characteristics of vulvar cancer in Tunisia. Two parts are distinguished in this study: Part1: Multicentric retrospective study about the characteristics of all cancer cases diagnosed during a 17-years period (January 1998-December 2014) in three departments of Gynecology and Obstetrics: one in south Tunisia and two in the capital. Part 2: To determine the Incidence trend of invasive vulvar cancer in North Tunisia 1994-2009, on the basis of North Cancer Registry of Tunisia. A total of 76 cases of vulvar cancer were recorded. The median age at diagnosis was 65.4years and 86.9% of patients were more than 55years old. The symptomatology was dominated by vulvar pruritus in 48.7%. The average size of the tumor was 3.96cm. Stage III was the most frequent (53.7%) followed by stage II (28.3%). Only 10.4% of tumors were at stage I. The most common histologic type of vulvar malignancy was squamous cell carcinoma (SCC) (94.7%). Standardized incidence varied from 1.2/100 000 (1994) to 0.5/100 000 (2009). There was significant decrease of Standardized incidence (APC of -8.8% per year, 95% CI: -5.5%, -9.0%-p<0.001). Vulvar cancer in Tunisia is a rare disease, occurs mostly in elderly women, and is diagnosed at advanced stages. Our findings emphasize that a greater effort should be made to facilitate early diagnosis, as treatment in earlier stages is less extensive and potentially curative. Copyright © 2017 National Cancer Institute, Cairo University. Production and hosting by Elsevier B.V. All rights reserved.

Nutrient removal from swine lagoon effluent by duckweed

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bergmann, B.A.; Cheng, J.; Classen, J.

2000-04-01

Three duckweed geographic isolates were grown on varying concentrations of swine lagoon effluent in a greenhouse to determine their ability to remove nutrients from the effluent. Duckweed biomass was harvested every other day over a 12-day period. Duckweed biomass production, nutrient loss from the swine lagoon effluent, and nutrient content of duckweed biomass were used to identify effluent concentrations/geographic isolate combinations that are effective in terms of nutrient utilization from swine lagoon effluent and production of healthy duckweed biomass. When Lemna minor geographic isolate 8627 was grown on 50% swine lagoon effluent, respective losses of TKN, NH{sub 3}-N, TP, OPO{submore » 4}-P, TOC, K, Cu, and Zn were 83, 100, 49, 31, 68, 21, 28 and 67%.« less

Accuracy of lagoon gas emissions using an inverse dispersion method

USDA-ARS?s Scientific Manuscript database

Measuring gas emissions from treatment lagoons and storage ponds poses challenging conditions for existing micrometeorological techniques because of non-ideal wind conditions. These include those induced by trees and crops surrounding the lagoons, and lagoons with dimensions too small to establish ...

Mosquito Lagoon environmental resources inventory

NASA Technical Reports Server (NTRS)

Provancha, Jane A.; Hall, Carlton R.; Oddy, Donna M.

1992-01-01

This document provides a synopsis of biotic and abiotic data collected in the Mosquito Lagoon area in relation to water quality. A holistic ecological approach was used in this review to allow for summaries of climate, land use, vegetation, geohydrology, water quality, fishes, sea turtles, wading birds, marine mammals, invertebrates, shellfish, and mosquito control. The document includes a bibliographic database list of 157 citations that have references to the Mosquito Lagoon, many of which were utilized in development of the text.

Sediment budget in the Lagoon of Venice, Italy

NASA Astrophysics Data System (ADS)

Sarretta, A.; Pillon, S.; Molinaroli, E.; Guerzoni, S.; Fontolan, G.

2010-05-01

A comparison of 1927, 1970 and 2002 bathymetric surveys in the Lagoon of Venice was used to reconstruct historical changes in sedimentation. A detailed GIS-based analysis of the charts revealed the timing and pattern of geomorphic changes and allowed calculation of sediment deposition and erosion for the entire lagoon and each of its four sub-basins: Treporti, Lido, Malamocco and Chioggia. Two main developments are discernible from comparative observation of the areal distribution of the main elevation ranges: the diminution in area of the saltmarshes, which decreased by more than 50%, from 68 km 2 in 1927 to 32 km 2 in 2002, and the progressive deepening of the lagoon, with a huge increase in the area of subtidal flats (between -0.75 and -2.00 m depth), from 88 to 206 km 2 during the same period. Generally, the lagoon showed a clear-cut change in the most frequent depths (modal depth) from a value of -0.62 m in 1927 to -0.88 m in 2002. The deepening of the lagoon affected mostly the lagoonal sub-basins south of the town of Venice, where modal depth increased from -0.65 to -1.12 m in Lido, from -0.64 to -1.75 m in Malamocco and from -0.39 to -0.88 m in Chioggia. Large changes in lagoonal morphology were caused by human-induced subsidence, the dredging of navigation channels between 1927 and 1970, and intense natural erosion enhanced by sediment re-suspension due to Manila clam fishing between 1970 and 2002. There was a net loss of about 110 Mm 3 of sediment from the lagoon, most of which (73 Mm 3, ca.70%) was in the earlier period. A significant amount was lost by dredging and direct disposal outside the system, either on land or at sea, and there was a net loss of 39 Mm 3 from the lagoon to the sea through the inlets, at an annual rate of 0.5 Mm 3. Comparison of erosion rates in the two periods revealed an alarming acceleration, from a net sediment loss of 0.3 Mm 3 yr -1 in the period 1927-1970 to 0.8 Mm 3 yr -1 in 1970-2002. Deterioration caused a shift from a

Metagenomes of Mediterranean Coastal Lagoons

PubMed Central

Ghai, Rohit; Hernandez, Claudia Mella; Picazo, Antonio; Mizuno, Carolina Megumi; Ininbergs, Karolina; Díez, Beatriz; Valas, Ruben; DuPont, Christopher L.; McMahon, Katherine D.; Camacho, Antonio; Rodriguez-Valera, Francisco

2012-01-01

Coastal lagoons, both hypersaline and freshwater, are common, but still understudied ecosystems. We describe, for the first time, using high throughput sequencing, the extant microbiota of two large and representative Mediterranean coastal lagoons, the hypersaline Mar Menor, and the freshwater Albufera de Valencia, both located on the south eastern coast of Spain. We show there are considerable differences in the microbiota of both lagoons, in comparison to other marine and freshwater habitats. Importantly, a novel uncultured sulfur oxidizing Alphaproteobacteria was found to dominate bacterioplankton in the hypersaline Mar Menor. Also, in the latter prokaryotic cyanobacteria were almost exclusively comprised by Synechococcus and no Prochlorococcus was found. Remarkably, the microbial community in the freshwaters of the hypertrophic Albufera was completely in contrast to known freshwater systems, in that there was a near absence of well known and cosmopolitan groups of ultramicrobacteria namely Low GC Actinobacteria and the LD12 lineage of Alphaproteobacteria. PMID:22778901

Benthic Primary Production Budget of a Caribbean Reef Lagoon (Puerto Morelos, Mexico)

PubMed Central

Naumann, Malik S.; Jantzen, Carin; Haas, Andreas F.; Iglesias-Prieto, Roberto; Wild, Christian

2013-01-01

High photosynthetic benthic primary production (P) represents a key ecosystem service provided by tropical coral reef systems. However, benthic P budgets of specific ecosystem compartments such as macrophyte-dominated reef lagoons are still scarce. To address this, we quantified individual and lagoon-wide net (Pn) and gross (Pg) primary production by all dominant functional groups of benthic primary producers in a typical macrophyte-dominated Caribbean reef lagoon near Puerto Morelos (Mexico) via measurement of O2 fluxes in incubation experiments. The photosynthetically active 3D lagoon surface area was quantified using conversion factors to allow extrapolation to lagoon-wide P budgets. Findings revealed that lagoon 2D benthic cover was primarily composed of sand-associated microphytobenthos (40%), seagrasses (29%) and macroalgae (27%), while seagrasses dominated the lagoon 3D surface area (84%). Individual Pg was highest for macroalgae and scleractinian corals (87 and 86 mmol O2 m−2 specimen area d−1, respectively), however seagrasses contributed highest (59%) to the lagoon-wide Pg. Macroalgae exhibited highest individual Pn rates, but seagrasses generated the largest fraction (51%) of lagoon-wide Pn. Individual R was highest for scleractinian corals and macroalgae, whereas seagrasses again provided the major lagoon-wide share (68%). These findings characterise the investigated lagoon as a net autotrophic coral reef ecosystem compartment revealing similar P compared to other macrophyte-dominated coastal environments such as seagrass meadows and macroalgae beds. Further, high lagoon-wide P (Pg: 488 and Pn: 181 mmol O2 m−2 lagoon area d−1) and overall Pg:R (1.6) indicate substantial benthic excess production within the Puerto Morelos reef lagoon and suggest the export of newly synthesised organic matter to surrounding ecosystems. PMID:24367570

Cystic echinococcosis in slaughtered domestic ruminants from Tunisia.

PubMed

Lahmar, S; Trifi, M; Ben Naceur, S; Bouchhima, T; Lahouar, N; Lamouchi, I; Maâmouri, N; Selmi, R; Dhibi, M; Torgerson, P R

2013-09-01

A total of 10,818 domestic ruminants (3913 cattle, 2722 sheep, 3779 goats, 404 dromedaries) slaughtered in various abattoirs in Tunisia between 2003 and 2010 were examined for the presence of Echinococcus granulosus hydatid cysts. The prevalence of cystic echinococcosis (CE) was 16.42% in sheep, 8.56% in cattle, 5.94% in dromedaries and 2.88% in goats. CE prevalence increased with age according to an asymptotic model and there was evidence of variation in infection pressure depending on the region of Tunisia where the animals were slaughtered. Cattle appeared to have the highest infection pressure of the species examined. The mean intensity of hepatic cysts was higher than that of pulmonary cysts in all species. The highest mean intensity of infection with E. granulosus larvae was observed in cattle (18.14) followed by sheep (9.58), goats (2.31) and dromedaries (2.12). The abundance of infection increased in a linear fashion with age in all animal species. Cyst abundance varied with species of animal and district of Tunisia. Cysts from dromedaries were more fertile (44.44%) than those from sheep (30.25%), goats (30.32%) and cattle (0.95%). The viability of the protoscoleces from fertile cysts from cattle (78.45%) was higher than those from sheep (70.71%) and camels (69.57%). The lowest protoscolex viability was recorded for hydatid cysts from goats (20.21%). This epidemiological study confirms the importance of CE in all domestic ruminant species, particularly in sheep, throughout Tunisia and emphasizes the need to interrupt parasite transmission by preventive integrated approaches in a CE control programme.

Virtual water balance estimation in Tunisia

NASA Astrophysics Data System (ADS)

Stambouli, Talel; Benalaya, Abdallah; Ghezal, Lamia; Ali, Chebil; Hammami, Rifka; Souissi, Asma

2015-04-01

The water in Tunisia is limited and unevenly distributed in the different regions, especially in arid zones. In fact, the annual rainfall average varies from less than 100 mm in the extreme South to over 1500 mm in the extreme North of the country. Currently, the conventional potential of water resources of the country is estimated about 4.84 billion m³ / year of which 2.7 billion cubic meters / year of surface water and 2.14 billion cubic meters / year of groundwater, characterizing a structural shortage for water safety in Tunisia (under 500m3/inhabitant/year). With over than 80% of water volumes have been mobilized for agriculture. The virtual water concept, defined by Allan (1997), as the amount of water needed to generate a product of both natural and artificial origin, this concept establish a similarity between product marketing and water trade. Given the influence of water in food production, virtual water studies focus generally on food products. At a global scale, the influence of these product's markets with water management was not seen. Influence has appreciated only by analyzing water-scarce countries, but at the detail level, should be increased, as most studies consider a country as a single geographical point, leading to considerable inaccuracies. The main objective of this work is the virtual water balance estimation of strategic crops in Tunisia (both irrigated and dry crops) to determine their influence on the water resources management and to establish patterns for improving it. The virtual water balance was performed basing on farmer's surveys, crop and meteorological data, irrigation management and regional statistics. Results show that the majority of farmers realize a waste of the irrigation water especially at the vegetable crops and fruit trees. Thus, a good control of the cultural package may result in lower quantities of water used by crops while ensuring good production with a suitable economic profitability. Then, the virtual water

Checklist, distribution, and a new record of Nepomorphan water bugs (Hemiptera: Heteroptera) in northern Tunisia.

PubMed

Slimani, Noura; Moulet, Pierre; Chen, Ping-Ping; Nieser, Nico; Pluot-Sigwalt, Dominique; Boumaïza, Moncef; Guilbert, Eric

2015-07-03

We report on the results of a survey of the Nepomorpha of northern Tunisia, and list twenty-three species belonging to twelve genera and seven families: Nepidae, Ochteridae, Corixidae, Micronectidae, Naucoridae, Notonectidae, and Pleidae. These records are based on intensive field surveys during the year 2013 and examination of the entomological collections of the National Museum Natural History of Paris. Ranatra linearis (Linnaeus, 1758) is recorded for the first time from Tunisia. The occurrence of Sigara (Halicorixa) stagnalis stagnalis (Leach, 1817) in Tunisia is confirmed. A preliminary checklist of the Nepomorpha of Northern Tunisia and updated distribution maps for all species treated are provided for further studies.

Bringing Community Colleges to Tunisia

ERIC Educational Resources Information Center

Hagedorn, Linda Serra; Mezghani, Wafa Thabet

2013-01-01

The country of Tunisia experienced intense uprisings and massive civil resistance that were termed the Arab Spring of 2010. The riots stemmed from a desire to topple government rulers who were blamed for the high unemployment, poverty, regional inequalities, and general political unrest within the country. In a quest for relief and prosperity,…

Reproductive Health Policy in Tunisia

PubMed Central

Goicolea, Isabel; Hernandez, Alison

2016-01-01

Abstract Although Tunisia is regarded as a pioneer in the Middle East and North Africa in terms of women’s status and rights, including sexual and reproductive health and rights, evidence points to a number of persisting challenges. This article uses the Health Rights of Women Assessment Instrument (HeRWAI) to analyze Tunisia’s reproductive health policy between 1994 and 2014. It explores the extent to which reproductive rights have been incorporated into the country’s reproductive health policy, the gaps in the implementation of this policy, and the influence of this policy on gender empowerment. Our results reveal that progress has been slow in terms of incorporating reproductive rights into the national reproductive health policy. Furthermore, the implementation of this policy has fallen short, as demonstrated by regional inequities in the accessibility and availability of reproductive health services, the low quality of maternal health care services, and discriminatory practices. Finally, the government’s lack of meaningful engagement in advancing gender empowerment stands in the way as the main challenge to gender equality in Tunisia. PMID:28559685

Lockport Sewage Lagoon.

ERIC Educational Resources Information Center

Perry, John

1995-01-01

Describes a student initiated stewardship project that resulted in the transformation of a sewage lagoon near the school into a place to study nature. Contains a list of 20 things that discourage a successful stewardship project. (LZ)

Nutrient-Chlorophyll Relationships in the Indian River Lagoon, Florida(SEERS)

EPA Science Inventory

The Indian River Lagoon is a highly diverse estuary located along Florida’s Atlantic coast. The system is made up of the main stem and two side-lagoons: the Banana River and Mosquito Lagoon. We segmented the main stem into three sections based on spatial trends in water quality ...

Hydrogen Sulfide Emissions from Sow Farm Lagoons across Climates Zones.

PubMed

Grant, Richard H; Boehm, Matthew T; Lawrence, Alfred J; Heber, Albert J

2013-11-01

Hydrogen sulfide (HS) emissions were measured periodically over the course of 2 yr at three sow waste lagoons representing humid mesothermal (North Carolina, NC), humid microthermal (Indiana, IN), and semiarid (Oklahoma, OK) climates. Emissions were determined using a backward Lagrangian stochastic model in conjunction with line-sampled HS concentrations and measured turbulence. The median annual sow-specific (area-specific) lagoon emissions at the OK farm were approximately 1.6 g head [hd] d (5880 µg m s), whereas those at the IN and NC sow farms were 0.035 g hd d (130 µg m s), and 0.041 g hd d (260 µg m s), respectively. Hydrogen sulfide emissions generally increased with wind speed. The daily HS emissions from the OK lagoon were greatest during the first half of the year and decreased as the year progressed. Emissions were episodic at the NC and IN lagoons. The generally low emissions at the NC and IN lagoons were probably a result of significant populations of purple sulfur bacteria maintained in the humid mesothermal and humid microthermal climates. Most of the large HS emission events at the NC and IN lagoons appeared to be a result of either precipitation events or liquid pump-out events. The high emissions at the OK lagoon in a semiarid climate were largely a result of high wind speeds enhancing both lagoon and air boundary layer mixing. The climate (air temperature, winds, and precipitation) appeared to influence the HS emissions from lagoons. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

77 FR 40790 - Republic of Tunisia Loan Guarantees Issued Under the Department of State, Foreign Operations, and...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-11

... AGENCY FOR INTERNATIONAL DEVELOPMENT 22 CFR Part 232 Republic of Tunisia Loan Guarantees Issued... benefit of the Republic of Tunisia pursuant to the State, Foreign Operations, and Related Programs... applicable to sums borrowed by Banque Centrale de Tunisie, acting on behalf of the Republic of Tunisia (the...

Is the Venice Lagoon Noisy? First Passive Listening Monitoring of the Venice Lagoon: Possible Effects on the Typical Fish Community.

PubMed

Bolgan, Marta; Picciulin, Marta; Codarin, Antonio; Fiorin, Riccardo; Zucchetta, Matteo; Malavasi, Stefano

2016-01-01

Three passive listening surveys have been carried out in two of the three Venice lagoon tide inlets and inside the Venice island. The spectral content and the intensity level of the underwater noise as well as the presence or absence of Sciaena umbra and the distribution of its different sound patterns have been investigated in all the recording sites. The passive listening proved to be successful in detecting S. umbra drumming sounds in both Venice lagoon tide inlets. Our results indicate that the spectral content and the level of underwater noise pollution in the Venice lagoon could affect fish acoustic communication.

Environmental enhancement of swine lagoons through influent treatment

USDA-ARS?s Scientific Manuscript database

Confined swine production generates large volumes of wastewater typically stored and treated in anaerobic lagoons. Failure of these lagoons during tropical storms in North Carolina along with major public environmental concerns led to a permanent state moratorium of construction of new anaerobic lag...

Mercury methylation and demethylation in Hg-contaminated lagoon sediments (Marano and Grado Lagoon, Italy)

NASA Astrophysics Data System (ADS)

Hines, Mark E.; Poitras, Erin N.; Covelli, Stefano; Faganeli, Jadran; Emili, Andrea; Žižek, Suzana; Horvat, Milena

2012-11-01

Mercury (Hg) transformation activities and sulfate (SO42-) reduction were studied in sediments of the Marano and Grado Lagoons in the Northern Adriatic Sea region as part of the "MIRACLE" project. The lagoons, which are sites of clam (Tapes philippinarum) farming, have been receiving excess Hg from the Isonzo River for centuries. Marano Lagoon is also contaminated from a chlor-alkali plant. Radiotracer methods were used to measure mercury methylation (230Hg, 197Hg), methylmercury (MeHg) demethylation (14C-MeHg) and SO42- reduction (35S) in sediment cores collected in autumn, winter and summer. Mercury methylation rate constants ranged from near zero to 0.054 day-1, generally decreased with depth, and were highest in summer. Demethylation rate constants were much higher than methylation reaching values of ˜0.6 day-1 in summer. Demethylation occurred via the oxidative pathway, except in winter when the reductive pathway increased in importance in surficial sediments. Sulfate reduction was also most active in summer (up to 1600 nmol mL-1 day-1) and depth profiles reflected seasonally changing redox conditions near the surface. Methylation and demethylation rate constants correlated positively with SO42- reduction and pore-water Hg concentrations, and inversely with Hg sediment-water partition coefficients indicating the importance of SO42- reduction and Hg dissolution on Hg cycling. Hg transformation rates were calculated using rate constants and concentrations of Hg species. In laboratory experiments, methylation was inhibited by amendments of the SO42--reduction inhibitor molybdate and by nitrate. Lagoon sediments displayed a dynamic seasonal cycle in which Hg dissolution in spring/summer stimulated Hg methylation, which was followed by a net loss of MeHg in autumn from demethylation. Sulfate-reducing bacteria (SRB) tended to be responsible for methylation of Hg and the oxidative demethylation of MeHg. However, during winter in surficial sediments, iron

Depositional history of the Late Barremian deposits (Sidi Aïch Formation) in central Tunisia and adjacent parts of Algeria: A geostatistical revelation

NASA Astrophysics Data System (ADS)

Aloui, Tahar; Ounis, Anouar; Dasgupta, Prabir; Lourimi, Wijden; Chaabani, Fredj

2018-07-01

The lithofacies analysis of the Sidi Aïch Formation and equivalents in Tunisia and adjacent parts of Algeria was carried out using probabilistic and quantitative approach as Discrete Time Markov Chain (DTMC) and entropy functions coupled with detailed sedimentary analyses with a view to decipher the Late Barremian depositional history. The Late Barremian successions exhibit asymmetric, fining-upward and retrograding to aggrading cycles in both outcrop and borehole data. Complete cycles typically start with intraformational conglomerates or trough and planar cross-stratified coarse sands, overlain by fine-grained sands, which are succeeded, in turn, by laminated sands, silts, clays and carbonates, and ends with paleosoils. Such ideal succession of lithofacies is observed at Zemlet el Baidha Hill in Tunisia and OuM.1 borehole in northeast Algeria marked by high values of entropy. The entropy analysis indicates deposition in a neritic environment with interplay of fluvial (and rarely alluvial) processes. The facies associations observed at Zemlet el Baidha Hill document evidences of wave and tide dominated coast with complex-gradient of environments that graded from neritic (upper to lower shoreface) to coastal settings (lagoons, embayments, restricted bays, mires, swamps etc.). The architecture of lithofacies appears to have been controlled by autocyclic processes (effects of local tectonics, basin bathymetry, lateral redistribution of deposits by longshore waves and tide currents) and allocyclic processes (global decrease of relative sea-level and sediments supply). Due to large salinity variations, wave action, ephemeral and local aspects of these marginal environments, the ichnodiversity was often limited in time and space, and inhibited the development of fossils during the onset of deposition of Sidi Aïch Formation and its equivalents.

Submarine groundwater discharge into typical tropical lagoons: A case study in eastern Hainan Island, China

NASA Astrophysics Data System (ADS)

Wang, Xilong; Du, Jinzhou

2016-11-01

Assessing submarine groundwater discharge (SGD) into lagoons and bays can be helpful to understand biogeochemical processes, especially nutrient dynamics. In the present paper, radium (Ra) isotopes were used to quantify SGD in two typical tropical lagoons (Laoye Lagoon (LY Lagoon) and Xiaohai Lagoon (XH Lagoon)) of eastern Hainan Island, China. The Ra mass balance model provided evidence that SGD plays an important role in the hydrology of the LY Lagoon and the XH Lagoon, delivering average SGD fluxes of 1.7 × 106 (94 L m-2 d-1) and 1.8 × 106 (41 L m-2 d-1) m3 d-1, respectively. Tidal pumping was one of the important driving forces for SGD fluxes in the LY and the XH Lagoons. Tidal-driven SGD into the tidal channels of both lagoons can account for approximately 10% of the total SGD flux into the lagoons. In addition, the dissolved inorganic nutrient budgets were reassessed in the LY Lagoon and the XH Lagoon, which showed that SGD was the major source of nutrients entering the LY Lagoon and that the LY Lagoon behaved as a source for dissolved inorganic nitrogen (DIN) and dissolved inorganic phosphorus (DIP) and as a sink for dissolved silicate (DSi). Nutrient loads in the XH Lagoon were mainly derived from riverine inputs and SGD, and the XH Lagoon behaved as a source for DIP, but a sink for DIN and DSi.

Comparison of the triple-point temperatures of {sup 20}Ne, {sup 22}Ne and normal Ne

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nakano, T.; Tamura, O.; Nagao, K.

2013-09-11

At the National Metrology Institute of Japan (NMIJ), the triple points of {sup 20}Ne and {sup 22}Ne were realized using modular sealed cells, Ec3Ne20 and Ec8Ne22, made by the Istituto Nazionale di Ricerca Metrologica (INRiM) in Italy. The difference of the triple-point temperatures of {sup 20}Ne and {sup 22}Ne was estimated by using the sub-range of standard platinum resistance thermometers (SPRTs) calibrated by NMIJ on the International Temperature Scale of 1990 (ITS-90). The melting curves obtained with the Ec3Ne20 and Ec8Ne22 cells show narrow widths (0.1 mK) over a wide range of the inverse of the melted fraction (1/F) frommore » 1/F=1 to 1/F=10. The liquidus point T{sub tp} estimated by the melting curves from F∼0.5 to F∼0.85 using the Ec8Ne22 is 0.146 29 (4) K higher than that using the Ec3Ne20 cell, which is in good agreement with that observed by INRiM using the same cells. After correction of the effect of impurities and other isotopes for Ec3Ne20 and Ec8Ne22 cells, the difference of T{sub tp} between pure {sup 20}Ne and pure {sup 22}Ne is estimated to be 0.146 61 (4) K, which is consistent with the recent results reported elsewhere. The sub-ranges of SPRTs computed by using the triple point of {sup 20}Ne or {sup 22}Ne realized by the Ec3Ne20 cell or the Ec8Ne22 cell in place of the triple point of Ne for the defining fixed point of the ITS-90 are in good agreement with those realized on the basis of the ITS-90 at NMIJ within 0.03 mK, which is much smaller than the non-uniqueness and the sub-range inconsistency of SPRTs.« less

Initial crop growth in soil collected from a closed animal waste lagoon.

PubMed

Zhu, L; Kirkham, M B

2003-03-01

In the 21st century, remediation of the soil beneath animal waste lagoons will become an important issue, as they are closed due to environmental regulations or to abandonment. The possibility of growing crops in the soil, which has high concentrations of ammonium-N, has not been studied. The objective of this experiment was to determine if crop species would germinate and grow in lagoon soil. Soil was gathered from a lagoon that had received wastes from swine (Sus scrofa) and beef (Bos taurus) since 1968. Eight crops were grown in greenhouse pots containing the lagoon soil: winter barley (Hordeum vulgare L. 'Weskan'); field corn (Zea mays L., Cargill's hybrid 7997); 'Plainsman' winter rapeseed [Brassica napus L. spp. oleifera (Metzg.) Sinsk. f. biennis]; soybean [Glycine max (L.) Merr. 'KS 4694'); forage sorghum [Sorghum bicolor (L.) Moench 'Norkan']; sunflower (Helianthus annuus L. 'Hysun 354'); and winter wheat (Triticum aestivum L.)--two cultivars: '2137' and 'Turkey.' Plants were grown for 35 days in lagoon soil or an agricultural soil (Haynie very fine sandy loam; coarse-silty, mixed, superactive, calcareous, mesic Mollic Udifluvent) obtained from a field near the closed lagoon. Ammonium-N (average value of 692 mg/kg) was about 70-85 times greater than the average value of 8-10 mg/kg NH4-N in Kansan soils. The lagoon soil was nonsodic and had a salinity ranking of "medium" with an electrical conductivity averaging 2.29 dS/m. The high ammonium-N concentration in the lagoon soil was not inhibitory to emergence and growth. The eight crops grew taller in the lagoon soil than in the agricultural soil. Except for '2137' wheat, dry weight was higher in the lagoon soil than in the agricultural soil. The results showed that the lagoon soil is not detrimental to early growth of eight crops.

Response of early Ruppia cirrhosa litter breakdown to nutrient addition in a coastal lagoon affected by agricultural runoff

NASA Astrophysics Data System (ADS)

Menéndez, Margarita

2009-05-01

The response of early Ruppia cirrhosa Petagna (Grande) litter decomposition to external nitrogen and phosphorus availability in La Tancada (Ebro River, NE Spain), a coastal lagoon that receives agricultural freshwater runoff from rice fields has been examined. Recently abscised dead R. cirrhosa stems were collected and 25 g of fresh weight was placed in litter bags with a mesh size of 100 μm and 1 mm. These bags were fertilised by adding nitrogen (N), a mixture of nitrogen plus phosphorus (N + P), or phosphorus (P), or were left untreated (CT). Macroinvertebrates were retrieved from the bags and the ash-free dry weight, and carbon, and N and P content of the remaining plant material were measured after 0, 3, 7, 14, 22 and 32 days. Litter decomposition rates, k (day -1), were estimated using a simple exponential model. Litter decay was clearly accelerated by the addition of P in the fine (100 μm) litter bags (0.042), but when N was added alone (0.0099) the decomposition rate was lower than in the CT treatments (0.022). No significant difference was observed between the N (0.0099-0.018) and N + P (0.0091-0.015) treatments in either the fine or the coarse (1 mm) litter bags. These results could be attributed to the relatively high availability of external (environmental) and internal (detritus contents) N. No significant effect of macro invertebrates was observed in the CT treatment or under N or P or N + P addition. The ratio between the decomposition rates in coarse and fine litter bags (k c/k f) was lower in disturbed Tancada lagoon (0.82) than in Cesine lagoon (2.11), a similar Mediterranean coastal water body with almost pristine conditions. These results indicate that, in addition to data on macroinvertebrate community structure, decomposition rates could also be used to assess water quality in coastal lagoons.

Overview of ecotoxicological studies performed in the Venice Lagoon (Italy).

PubMed

Losso, C; Ghirardini, A Volpi

2010-01-01

This work reports on the state of the art of the bioindicators used to assess environmental quality (regarding chemical pollutant impacts) in the Venice lagoon. After a brief description of the roles, advantages and limitations of bioindicators in marine and transitional environments and a summary of the Venice lagoon characteristics, the ecotoxicological methods used during scientific studies and research projects in the Lagoon are reported. Since not all data are available and no database can be formulated, the main evidence from toxicity bioassays, biomarkers and bioaccumulation analyses since the end of the 1970s is spatially synthesized using maps and discussed according to the four Venice lagoon basins. The majority of indicators showed that the Lido basin (north-central lagoon), affected by the presence of the industrial area and the city of Venice, is the one most highly impacted (particularly in the sites located within or in front of the industrial area, which showed very high sediment toxicity and high levels of DNA damage). The Malamocco basin (south-central lagoon) seems to be the least problematic. The southern basin (Chioggia basin) was shown to be impacted by urban contaminants from the town of Chioggia. The northern basin (Treporti basin) presented both impacted sites (high toxicity and high bioaccumulation factor) and relatively unpolluted sites (absence of toxicity, absence of imposex and low levels of bioaccumulation). This review can serve as a basis on which to select pragmatic, cost-effective biomonitoring techniques for environmental effects in lagoon ecosystems.

Challenges of Globalization: Morocco and Tunisia. Curriculum Projects. Fulbright-Hays Summer Seminars Abroad Program, 2001 (Morocco and Tunisia).

ERIC Educational Resources Information Center

2002

This publication contains a collection of curriculum projects developed by educators who were participants in the 2001 Fulbright-Hays Summer Seminars Abroad Program in Morocco and Tunisia. The 13 curriculum projects in the publication are entitled: "Women in Morocco, Artists and Artisans" (Virginia da Costa); "Cultures of…

Helium-carbon isotopic composition of thermal waters from Tunisia

NASA Astrophysics Data System (ADS)

Fourré, E.; Aiuppa, A.; di Napoli, R.; Parello, F.; Gaubi, E.; Jean-Baptiste, P.; Allard, P.; Calabrese, S.; Ben Mammou, A.

2010-12-01

Tunisia has numerous thermo-mineral springs. Previous studies have shown that their chemical composition and occurrence are strongly influenced by the regional geology, however little work has been conducted to date to investigate the isotopic composition of volatiles associated with these geothermal manifestations. Here, we report the results of an extensive survey of both natural hot springs and production wells across Tunisia aimed at investigating the spatial distribution of the 3He/4He ratio and associated carbon isotopic compositions. With respect to helium isotopes, not unexpectedly, the lowest 3He/4He values (0.01-0.02 Ra) are associated with the old groundwaters of the “Continental Intercalaire” aquifer of the stable Saharan Platform. The 3He/4He values are equal to the crustal production ratio, with no detectable amount of mantle-derived 3He, in agreement with previous studies of helium isotopes in sedimentary basin, which conclude that tectonically-stable regions are essentially impermeable to mantle volatiles. The low 3He/4He domain extends to the entire Atlasic domain of central Tunisia. This Atlasic domain also displays the highest helium concentrations : along the Gafsa Fault, helium concentrations of 1777 and 4723 x 10-8 cm3STP/g (the highest value of our data set) are observed in the production wells of Sidi Ahmed Zarrouk. This emphasizes the role of deep tectonic features in channelling and transporting deep crustal volatiles to shallow levels. The eastern margin of Tunisia displays higher 3He/4He values indicative of a substantial mantle volatile input. The highest value is recorded in the carbo-gaseous mineral water of Ain Garci (2.4 Ra). This northeastern part of the African plate commonly referred to as the Pelagian block extends from Tunisia to Sicily and is characterized by strong extensional tectonics (Pantelleria rift zone) and present-day magmatic activity. This lithospheric stretching and decompressional mantle melts production in

Macroalgae, nutrient cycles, and pollutants in the lagoon of Venice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sfriso, A.; Pavoni, B.; Marcomini, A.

1992-12-01

The Lagoon of Venice is a wide, shallow coastal basin that extends for about 50 km along the northwest coast of the Adriatic Sea. The lagoon has been substantially modified through the actions of man over the last century through the artificial control of the hydraulic dynamics of the lagoon including the construction of channels to facilitate navigation. The lagoon is subjected to considerable pollutant loading through the drainage of land under cultivation, municipal sewage, and industrial effluents. In this paper are reported the results of observations designed to document recent changes in macroalgal species composition, seasonal cycles of primarymore » producers and nutrient levels, and the effects of the macroalgal community on concentrations of organic and inorganic pollutants. The dominant macroalgae in the lagoon was Ulva rigida, and the levels of plant nutrients and pollutants were influenced by the seasonal cycles of the macroalgal community. 44 refs., 11 figs., 2 tabs.« less

Surface Water Quality Survey of Northern Indian River Lagoon from Sebastian Inlet to Mosquito Lagoon

NASA Astrophysics Data System (ADS)

Weaver, R. J.; Webb, B. M.

2012-12-01

Following news of an emerging brown tide algal bloom in the northern Indian River Lagoon (IRL), researchers sought to gain insight into the surface water quality in the IRL, as well as the extent of the algae coverage. A Portable SeaKeeper from YSI, mounted to a personal watercraft-based coastal profiling system, autonomously collected and analyzed the surface water. The system operates by recording sample data every 12 seconds while continuously underway at speeds up to and greater than 50 km/hr. The researchers covered a transect that started at Sebastian Inlet and followed a zig-zag path extending up through the Haulover Canal and into the Mosquito Lagoon. The survey path covered 166.7 km, and collected 2248 samples. Along the way stops were made at water quality stations used by the Saint John's River Water Management District, so that the data collected can be incorporated into ongoing monitoring efforts. The system analyzed the surface water for dissolved oxygen, pH, chlorophyll-a, salinity, temperature, turbidity, refined fuels, and CDOM. In the two days following the lagoon survey, the inlets at Port Canaveral and Sebastian were also surveyed for tidal currents and hydrography. The IRL transect survey data recorded evidence of the southern extent of the algae bloom in both chlorophyll-a and pH levels. Visual evidence of the bloom was striking as the water in the northern IRL turned a milk chocolaty brown color. Chlorophyll-a levels in the two inlets suggested bloom activity at these locations; however this bloom was different. This oceanic bloom was a result of a persistent upwelling event along the East Florida shelf, and the color was a paler green-yellow. The near-synoptic nature of the comprehensive lagoon survey, conducted in just over 7 hours, allows researchers to obtain a better understanding of water quality in coastal lagoons. Elevated levels of salinity, temperature, and refined fuels in the northern IRL indicate a low exchange rate and absence

Metagenomic Survey of a Military-Impacted Lagoon in Puerto Rico

NASA Astrophysics Data System (ADS)

Davila-Santiago, L.; DeLeon-Rodriguez, N.; LaSanta-Pagan, K. Y.; Kurt, Z.; Padilla-Crespo, E.; Hatt, J.; Spain, J.; Konstantinidis, K.; Massol-Deya, A.

2016-02-01

Military practices have left a legacy of contamination worldwide. In Puerto Rico, the east part of the populated Vieques Island was used for over fifty years as a bombing range by the Navy. A year after the base was closed in 2003, the impacted area was designated as a Superfund site. Previous studies have shown elevated levels of heavy metals, explosives (e.g. RDX, TNT, HMX), and other toxic chemicals at the site. The Anones Lagoon, located in the middle of the bombing range is one of the most polluted spots within the site. Intermittently, the lagoon is connected through a channel to the Caribbean Sea. In order to describe the microbial diversity and its potential contribution to natural attenuation of explosives, sediment samples have been collected since 2005. Sediment from reference lagoons (San Juan and Cabo Rojo) have also been sampled and analyzed in parallel for comparisons. Total DNA was extracted and sequenced using Ilumina My-Seq platform. Results indicate that Gammaproteobacteria were abundant in all lagoons samples but the Vieques lagoon harbors overall different microbial taxa. Alpha diversity analysis showed that Anones was less diverse compared to the pristine Cabo Rojo lagoon. Importantly, a clear shift was seen in the Anones Lagoon in 2013 compared to 2005, were Halomonas spp. became dominant (up to 25%) while other groups like Marinobacter showed signs of enrichment as well. Interestingly, these groups have been shown to degrade explosive-related chemicals in tropical sediments. Functional gene annotation of the Anones metagenome showed the presence of RDX degradation genes such as cytochrome p450. This study is the first comparative metagenomic survey of lagoons in Puerto Rico that explored the microbial diversity and biodegradation potential at Vieques.

Sludge Lagoons. Sludge Treatment and Disposal Course #166. Instructor's Guide [and] Student Workbook.

ERIC Educational Resources Information Center

Sharman, Ronald M.

This lesson describes three different types of sludge lagoons: (1) drying lagoons; (2) facultative lagoons; and (3) anaerobic lagoons. Normal operating sequence and equipment are also described. The lesson is designed to be used in sequence with the complete Sludge Treatment and Disposal Course #166 or as an independent lesson. The instructor's…

Enterovirus Migration Patterns between France and Tunisia

PubMed Central

Othman, Ines; Mirand, Audrey; Slama, Ichrak; Mastouri, Maha; Peigue-Lafeuille, Hélène; Aouni, Mahjoub; Bailly, Jean-Luc

2015-01-01

The enterovirus (EV) types echovirus (E-) 5, E-9, and E-18, and coxsackievirus (CV-) A9 are infrequently reported in human diseases and their epidemiologic features are poorly defined. Virus transmission patterns between countries have been estimated with phylogenetic data derived from the 1D/VP1 and 3CD gene sequences of a sample of 74 strains obtained in France (2000–2012) and Tunisia (2011–2013) and from the publicly available sequences. The EV types (E-5, E-9, and E-18) exhibited a lower worldwide genetic diversity (respective number of genogroups: 4, 5, and 3) in comparison to CV-A9 (n = 10). The phylogenetic trees estimated with both 1D/VP1 and 3CD sequence data showed variations in the number of co-circulating lineages over the last 20 years among the four EV types. Despite the low number of genogroups in E-18, the virus exhibited the highest number of recombinant 3CD lineages (n = 10) versus 4 (E-5) to 8 (E-9). The phylogenies provided evidence of multiple transportation events between France and Tunisia involving E-5, E-9, E-18, and CV-A9 strains. Virus spread events between France and 17 other countries in five continents had high probabilities of occurrence as those between Tunisia and two European countries other than France. All transportation events were supported by BF values > 10. Inferring the source of virus transmission from phylogenetic data may provide insights into the patterns of sporadic and epidemic diseases caused by EVs. PMID:26709514

Enterovirus Migration Patterns between France and Tunisia.

PubMed

Othman, Ines; Mirand, Audrey; Slama, Ichrak; Mastouri, Maha; Peigue-Lafeuille, Hélène; Aouni, Mahjoub; Bailly, Jean-Luc

2015-01-01

The enterovirus (EV) types echovirus (E-) 5, E-9, and E-18, and coxsackievirus (CV-) A9 are infrequently reported in human diseases and their epidemiologic features are poorly defined. Virus transmission patterns between countries have been estimated with phylogenetic data derived from the 1D/VP1 and 3CD gene sequences of a sample of 74 strains obtained in France (2000-2012) and Tunisia (2011-2013) and from the publicly available sequences. The EV types (E-5, E-9, and E-18) exhibited a lower worldwide genetic diversity (respective number of genogroups: 4, 5, and 3) in comparison to CV-A9 (n = 10). The phylogenetic trees estimated with both 1D/VP1 and 3CD sequence data showed variations in the number of co-circulating lineages over the last 20 years among the four EV types. Despite the low number of genogroups in E-18, the virus exhibited the highest number of recombinant 3CD lineages (n = 10) versus 4 (E-5) to 8 (E-9). The phylogenies provided evidence of multiple transportation events between France and Tunisia involving E-5, E-9, E-18, and CV-A9 strains. Virus spread events between France and 17 other countries in five continents had high probabilities of occurrence as those between Tunisia and two European countries other than France. All transportation events were supported by BF values > 10. Inferring the source of virus transmission from phylogenetic data may provide insights into the patterns of sporadic and epidemic diseases caused by EVs.

Toxic metals in Venics lagoon sediments: Model, observation, an possible removal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Basu, A.; Molinaroli, E.

1994-11-01

We have modeled the distribution of nine toxic metals in the surface sediments from 163 stations in the Venice lagoon using published data. Three entrances from the Adriatic Sea control the circulation in the lagoon and divide it into three basins. We assume, for purposes of modeling, that Porto Marghera at the head of the Industrial Zone area is the single source of toxic metals in the Venice lagoon. In a standing body of lagoon water, concentration of pollutants at distance x from the source (C{sub 0}) may be given by C=C{sub 0}e{sup -kx} where k is the rate constantmore » of dispersal. We calculated k empirically using concentrations at the source, and those farthest from it, that is the end points of the lagoon. Average k values (ppm/km) in the lagoon are: Zn 0.165, Cd 0.116, Hg 0.110, Cu 0.105, Co 0.072, Pb 0.058, Ni 0.008, Cr (0.011) and Fe (0.018 percent/km), and they have complex distributions. Given the k values, concentration at source (C{sub 0}), and the distance x of any point in the lagoon from the source, we have calculated the model concentrations of the nine metals at each sampling station. Tides, currents, floor morphology, additional sources, and continued dumping perturb model distributions causing anomalies (observed minus model concentrations). Positive anomalies are found near the source, where continued dumping perturbs initial boundary conditions, and in areas of sluggish circulation. Negative anomalies are found in areas with strong currents that may flush sediments out of the lagoon. We have thus identified areas in the lagoon where higher rate of sediment removal and exchange may lesson pollution. 41 refs., 4 figs., 3 tabs.« less

Migration pattern of hepatitis A virus genotype IA in North-Central Tunisia.

PubMed

Beji-Hamza, Abir; Taffon, Stefania; Mhalla, Salma; Lo Presti, Alessandra; Equestre, Michele; Chionne, Paola; Madonna, Elisabetta; Cella, Eleonora; Bruni, Roberto; Ciccozzi, Massimo; Aouni, Mahjoub; Ciccaglione, Anna Rita

2015-02-08

Hepatitis A virus (HAV) epidemiology in Tunisia has changed from high to intermediate endemicity in the last decades. However, several outbreaks continue to occur. The last reported sequences from Tunisian HAV strains date back to 2006. In order to provide an updated overview of the strains currently circulating in Tunisia, a large-scale molecular analysis of samples from hepatitis A cases was performed, the first in Tunisia. Biological samples were collected from patients with laboratory confirmed hepatitis A: 145 sera samples in Tunis, Monastir, Sousse and Kairouan from 2008 to 2013 and 45 stool samples in Mahdia in 2009. HAV isolates were characterised by nested RT-PCR (VP1/2A region) and sequencing. The sequences finally obtained from 81 samples showed 78 genotype IA and 3 genotype IB isolates. A Tunisian genotype IA sequence dataset, including both the 78 newly obtained IA sequences and 51 sequences retrieved from GenBank, was used for phylogenetic investigation, including analysis of migration pattern among six towns. Virus gene flow from Sfax and Monastir was directed to all other towns; in contrast, the gene flows from Sousse, Tunis, Mahdia and Kairouan were directed to three, two, one and no towns, respectively. Several different HAV strains co-circulate in Tunisia, but the predominant genotype still continues to be IA (78/81, 96% isolates). A complex gene flow (migration) of HAV genotype IA was observed, with Sfax and Monastir showing gene flows to all other investigated towns. This approach coupled to a wider sampling can prove useful to investigate the factors underlying the spread of HAV in Tunisia and, thus, to implement appropriate preventing measures.

First steps of ecological restoration in Mediterranean lagoons: Shifts in phytoplankton communities

NASA Astrophysics Data System (ADS)

Leruste, A.; Malet, N.; Munaron, D.; Derolez, V.; Hatey, E.; Collos, Y.; De Wit, R.; Bec, B.

2016-10-01

Along the French Mediterranean coast, a complex of eight lagoons underwent intensive eutrophication over four decades, mainly related to nutrient over-enrichment from continuous sewage discharges. The lagoon complex displayed a wide trophic gradient from mesotrophy to hypertrophy and primary production was dominated by phytoplankton communities. In 2005, the implementation of an 11 km offshore outfall system diverted the treated sewage effluents leading to a drastic reduction of anthropogenic inputs of nitrogen and phosphorus into the lagoons. Time series data have been examined from 2000 to 2013 for physical, chemical and biological (phytoplankton) variables of the water column during the summer period. Since 2006, total nitrogen and phosphorus concentrations as well as chlorophyll biomass strongly decreased revealing an improvement in lagoon water quality. In summertime, the decline in phytoplankton biomass was accompanied by shifts in community structure and composition that could be explained by adopting a functional approach by considering the common functional traits of the main algal groups. These phytoplankton communities were dominated by functional groups of small-sized and fast-growing algae (diatoms, cryptophytes and green algae). The trajectories of summer phytoplankton communities displayed a complex response to changing nutrient loads over time. While diatoms were the major group in 2006 in all the lagoons, the summer phytoplankton composition in hypertrophic lagoons has shifted towards green algae, which are particularly well adapted to summertime conditions. All lagoons showed increasing proportion and occurrence of peridinin-rich dinophytes over time, probably related to their capacity for mixotrophy. The diversity patterns were marked by a strong variability in eutrophic and hypertrophic lagoons whereas phytoplankton community structure reached the highest diversity and stability in mesotrophic lagoons. We observe that during the re

Structuring and evolution of Neogene transcurrent basins in the Tellian foreland domain, north-eastern Tunisia

NASA Astrophysics Data System (ADS)

Melki, Fetheddine; Zouaghi, Taher; Harrab, Salah; Sainz, Antonio Casas; Bédir, Mourad; Zargouni, Fouad

2011-07-01

The Neogene sedimentary basins (Serravallian to Quaternary) of the Tellian tectonic foreland in north-eastern Tunisia formed within the overall NE-SW sinistral strike-slip tectonic framework of the Ras El Korane-Thibar and El Alia-Teboursouk fault systems. From stratigraphic logs, structural cross sections and interpretation of 2D seismic lines and boreholes, the pre-Neogene basement can be interpreted to be structured according to Eocene (NW-SE) compressional and Oligocene extensional phases. This basement comprises structural highs (anticlines and horsts) and subsiding areas (synclines, half-grabens and grabens) formed during the Neogene. The subsiding areas are delineated by faults striking N030E, N-S and N140E, defining (i) narrow, strongly subsiding synclines, (ii) lozenge-shaped basins and (iii) trapezoidal basins. The architecture of their fill results from the sedimentary balance between tectonics and eustatism. Halokinesis and clay diapirism (driven by Triassic and Neogene evaporites and clays) also played an important role in basin evolution, contributing to the formation of domes and diapirs along active faults.

Atmospheric particle-bound organophosphate ester flame retardants and plasticizers in a North African Mediterranean coastal city (Bizerte, Tunisia).

PubMed

Castro-Jiménez, Javier; Sempéré, Richard

2018-06-12

Organophosphate ester (OPE) flame retardants and plasticizers have been detected at generally high frequencies (70-98%) for the first time in the atmosphere over the NW African coastal Mediterranean. Results from sixty air samples (total suspended particles, TSP) collected between March 2015 and January 2016 in an urban coastal site (Bizerte, Tunisia) revealed ∑ 9 OPE concentrations of ~100-1060 pg m -3 (470 pg m -3 , median) with TCPPs, EHDPP and TiBP exhibiting the higher median concentrations (~110, 100 and 85 pg m -3 , respectively). Spring generally exhibited the lowest concentrations, probably linked to the influence of local meteorological conditions and air mass trajectories to a lesser extent. Non-chlorinated OPEs generally predominated, in contrast to the most common reported situation in marine environments (i.e. higher abundance of chlorinated OPEs) pointing to the relevance of local OPE sources in the study area. TiBP levels were generally higher than those reported for other marine/coastal environments suggesting this OPE as a good tracer of local sources in Bizerte. Contrarily, the atmospheric levels of other abundant OPEs in the area (e.g. TCPP) seem to be in the range and/or lower than those reported for remote marine environments. These findings point to the interplay of different factors with solar irradiance (potentially enhancing atmospheric photochemical oxidation reactions) and meteorological conditions in the study area likely compensating potential local sources of some OPEs. Not all OPEs presented the same seasonality in terms of atmospheric concentrations and pattern. The estimated atmospheric dry deposition fluxes (∑ 9 OPEs) were 18-180 ng m -2  d -1 . Up to ~9 kg y -1 of OPEs (~1 kg y -1 of new organic anthropogenic phosphorus coming from OPEs) can be loaded to the shallow and enclosed Bizerte lagoon (~130 km 2 ), considered as the most important aquaculture area in Tunisia, with yet unknown implications

DESIGN INFORMATION REPORT: PROTECTION OF WASTEWATER LAGOON INTERIOR SLOPES

EPA Science Inventory

A problem common to many wastewater treatment and storage lagoons is erosion of the interior slopes. Erosion may be caused by surface runoff and wind-induced wave action. The soils that compose the steep interior slopes of lagoons are especially susceptible to erosion and slumpin...

Coastal Processes with Improved Tidal Opening in Chilika Lagoon (east Coast of India)

NASA Astrophysics Data System (ADS)

Jayaraman, Girija; Dube, Anumeha

Chilika Lagoon (19°28-19°54¢N and 85°06-85°36¢E) is the largest brackish water lagoon with estuarine character. Interest in detailed analysis of the ecology of the lagoon and the various factors affecting it is due to the opening of the new mouth on September 23, 2000 to resolve the threat to its environment from various factors - Eutrophication, weed proliferation, siltation, industrial pollution, and depletion of bioresources. The opening of the new mouth has changed the lagoon environment significantly with better socio­economic implications. There is a serious concern if the significant improvement in the biological productivity of the lagoon post-mouth opening is indeed sustainable. The present study focuses on the changes in the coastal processes as a result of the additional opening of a new mouth. Our results based on mathematical modeling and numerical simulation compare the dynamics, nutrient, and plankton distribution before and after the new mouth opening. The model could confirm the significant increase (14-66% depending on the sector) in the salinity after the new mouth opening, the maximum change being observed in the channel which connects the lagoon to the sea. The constriction in the lagoon which blocks the tidal effects entering the lagoon must be responsible for maintaining the main body of the lagoon with low salinity. The ecological model is first tested for different sectors individually before a complete model, including the entire lagoon area, is included incorporating their distinct characteristics. The model is validated with available observations of plankton and nutrients made before the opening of the new mouth. It predicts the annual distribution of plankton in all the sectors of the lagoon for post-mouth opening which is to be verified when the data will be forthcoming.

Coastal Processes with Improved Tidal Opening in Chilika Lagoon (east Coast of India)

NASA Astrophysics Data System (ADS)

Jayaraman, Girija; Dube, Anumeha

Chilika Lagoon (19°28-19°54'N and 85°06-85°36'E) is the largest brackish water lagoon with estuarine character. Interest in detailed analysis of the ecology of the lagoon and the various factors affecting it is due to the opening of the new mouth on September 23, 2000 to resolve the threat to its environment from various factors — Eutrophication, weed proliferation, siltation, industrial pollution, and depletion of bioresources. The opening of the new mouth has changed the lagoon environment significantly with better socio-economic implications. There is a serious concern if the significant improvement in the biological productivity of the lagoon post-mouth opening is indeed sustainable. The present study focuses on the changes in the coastal processes as a result of the additional opening of a new mouth. Our results based on mathematical modeling and numerical simulation compare the dynamics, nutrient, and plankton distribution before and after the new mouth opening. The model could confirm the significant increase (14-66% depending on the sector) in the salinity after the new mouth opening, the maximum change being observed in the channel which connects the lagoon to the sea. The constriction in the lagoon which blocks the tidal effects entering the lagoon must be responsible for maintaining the main body of the lagoon with low salinity. The ecological model is first tested for different sectors individually before a complete model, including the entire lagoon area, is included incorporating their distinct characteristics. The model is validated with available observations of plankton and nutrients made before the opening of the new mouth. It predicts the annual distribution of plankton in all the sectors of the lagoon for post-mouth opening which is to be verified when the data will be forthcoming.

Chemistry of modern sediments in a hypersaline lagoon, north of Jeddah, Red Sea

NASA Astrophysics Data System (ADS)

El-Sayed, Mahmoud Kh.

1987-10-01

Previous studies of modern peritidal sedimentary environments of the Red Sea, such as hypersaline lagoons and sea-marginal flats, have concentrated on its northern part, particularly in the Gulf of Aqaba. However, little is known about lagoon sediments in other localities along the Red Sea coastal stretches. This paper deals with the chemical characteristics of the sediments of a hypersaline (Ras Hatiba) lagoon, north of Jeddah, Saudi Arabia. The chemistry of hypersaline lagoon sediments is considerably changed following the modifications to the water chemistry by evaporation and precipitation. Ras Hatiba lagoon is a hypersaline elongated water body connected to the Red Sea by a narrow and shallow opening. The total area of the lagoon is c. 30 km 2. Coarse bioclastic sands are dominant in the lagoon and mostly surround lithified calcareous grounds. However, fine silt and clay sediments are present in separate patches. The sediments are rich in carbonates (average 78·5%) and organic carbon (average 7·3%), although they are negatively correlated. Calcium (average 25·1%) and magnesium (average 10·8‰) show a similar distribution pattern in the lagoon sediments. Strontium (average 5·2‰) is positively correlated with calcium. Sodium and potassium are relatively highly concentrated in the sediments (average 118 ppm and 173 ppm, respectively). Magnesium and strontium are of prime importance in the process of mineralization and diagenesis. The sabkha formation surrounding the lagoon is of low carbonate and organic carbon content, compared with the lagoon sediments, whilst it is characterized by high magnesium, sodium and potassium concentrations. Ras Hatiba lagoon sediments and sabkha resemble those of the northern Red Sea in the Gulfs of Aqaba and Suez and the Arabian Gulf in their major sedimentological and chemical characteristics.

Educational Television and Educational Development in Tunisia.

ERIC Educational Resources Information Center

National Association of Educational Broadcasters, Washington, DC.

The National Association of Educational Broadcasters attempted to determine how educational television and related technologies could strengthen the educational system of Tunisia. An overview of the Tunisian society is presented, followed by a brief history of the development of its educational system. The tremendous educational needs of the…

English versus French: Language Rivalry in Tunisia.

ERIC Educational Resources Information Center

Battenburg, John

1997-01-01

Examines the competition between English and French in Tunisian educational institutions and programs. Scrutinizes two periods in postprotectorate Tunisia: the introduction of English and the spread of English. Findings indicate that the decline in French linguistic influence may be accompanied by a future decrease in French political and economic…

The distribution of salinity and main forcing effects in the Berre lagoon

NASA Astrophysics Data System (ADS)

Roux, Bernard; Alekseenko, Elena; Chen, Paul Gang; Kharif, Christian; Kotarba, Richard; Fougere, Dominique

2014-05-01

The results from previous studies in lagoons and well mixed estuaries indicate that salt transport is primarily in response to advection associated with freshwater outflow, tidal diffusion, and to shear effects arising from spatial correlations of vertical and especially transverse deviations in salinity and current speed (Smith, 1994). Therefore, the inflow of fresh and salt water into coastal lagoons is an important factor influencing the structure and function of lagoonal ecosystems worldwide (Lirman et al., 2007). The predominance of marine or freshwater inflow leads to the different ecosystems. Among several lagoons located along the Mediterranean shore of France, the Berre lagoon has been under intense anthropogenic pressure for several decades (Delpy et al., 2012). Moreover, the salinity level of the Berre lagoon was varying dramatically from the 19th century up to now. In this work, a special attention is focused on the salinity variation in the Berre lagoon due to the three dominant abiotic forcing mechanisms, i.e., incoming sea tide, runoff from a hydropower and a strong wind. Four different model scenarios were considered in order to examine the impact of each forcing mechanism or combined effects, i.e. : (a) tide only, (b) runoff only, (c) combined tide and runoff, and (d) an N-NW wind, tide and runoff together. Numerical modeling and interpretation of numerical results are based on three-dimensional hydrodynamic model MARS3D. It is found that the strongest negative impact is related to the huge hydropower runoffs, inducing the desalinization of the surface and subsurface waters not only in the centre of the lagoon, but also in the entire water column in the coastal seagrass recolonization zones. In the absence of wind, the huge inputs of freshwater from the hydropower lead to a haline stratification and thus, to anoxic conditions, making most of the lagoon unproductive. On the contrary, strong winds play a positive role on the salinity level of the

Environmental Assessment of the Bolinas Lagoon: a study utilizing benthic foraminifera

NASA Astrophysics Data System (ADS)

Benton, L.; Espinoza Madrid, N.; Grande, C.

2016-12-01

Benthic foraminifera have long been recognized for their utility in environmental assessments. They are abundant, diverse, and found in all marine environments, but species distributions depend largely on local environmental conditions. This study analyses benthic foraminiferal assemblages from the Bolinas Lagoon, Marin County, California. The Careers in Science Intern Program collected 36 sediment samples from 13 sites within the Bolinas Lagoon. Foraminiferal assemblages for each site are reported, and species richness, relative abundance, and Shannon's diversity calculated. Results indicate that Shannon's diversity is low throughout the Bolinas Lagoon and stress tolerant taxa are abundant, which suggests that current conditions in the Bolinas Lagoon are sub optimal.

[Social determinants of contraceptive use in Tunisia].

PubMed

Dimassi, K; Douik, F; Douzi, M A; Saidi, O; Ben Romdhane, H

2017-02-01

In Tunisia, the "Revolution" of January 2011 highlighted significant regional disparities and social inequalities in access to health care, including reproductive health services. The purpose of this study was to analyze the social determinants of the use of contraception in Tunisia. A cross-sectional national study conducted in 2012; on a sample of 15 to 49-year married women (n=4374) drawn by a two levels random sampling. Prevalence of contraception and its association factors were assessed. Logistic regression was used to evaluate the variation of contraception prevalence with area of residence, age, level of education, number of children and household income. The prevalence of contraception was 66.4 %. Eighty-two percent of women used a modern contraceptive method. The use of contraceptive methods was significantly dependent on the age (P<0.001), area of residence (P=0.008), education (P<0.001). The prevalence of contraception was higher in North West (OR=1.1 [0.81-1.5]; P<0.001), among multiparous women (OR=4.49 [3.57-5.66]; P<0.001), among the youngest women (OR=1.4 [0.9-2,19]; P<0.001) and among those with higher levels of education (OR=1.62 [1.19-2.21]; P=0.008). Tunisia, precursor Arab country in family planning, is recording a slowdown in the use of contraception in comparison with other countries of North Africa. Social determinants, such as, age, living conditions, area of residence and level of education are indicators to consider when targeting interventions. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

L'enseignement superieur tunisien: Enjeux et avenir (Higher Education in Tunisia: Challenges and Opportunities).

ERIC Educational Resources Information Center

World Bank, Washington, DC.

This report presents findings of a study of higher education in Tunisia. It finds that higher education in Tunisia is a largely effective and well-performing system. However, it notes an expected doubling of enrollment over the next 10 years which will create obstacles that prevent it from playing the role expected of it by a society and economy…

Evaluation of short-rotation woody crops to stabilize a decommissioned swine lagoon

Treesearch

K.C. Dipesh; Rodney E. Will; Thomas C. Hennessey; Chad J. Penn

2012-01-01

Fast growing tree stands represent an environmentally friendly, less expensive method for stabilization of decommissioned animal production lagoons than traditional lagoon closure. We tested the feasibility of using short-rotation woody crops (SRWCs) in central Oklahoma to close a decommissioned swine lagoon by evaluating the growth performance and nutrient uptake of...

Seasonal Variability in Mercury Speciation within Select Coastal Lagoons of Central California

NASA Astrophysics Data System (ADS)

Ganguli, P. M.; Conaway, C. H.; Dimova, N. T.; Swarzenski, P. W.; Kehrlein, N. C.; Flegal, A. R.

2011-12-01

Coastal lagoons may play an important role in mercury biogeochemical cycling at the land-sea margin. Along the coast of California, these systems are seasonally dynamic, behaving as estuaries during the wet season and as lagoons in the dry season when ephemeral sand berms develop and isolate terrestrial freshwater from direct exchange with the ocean. As a consequence, many lagoons become eutrophic in the dry season and are characterized by high nutrient and low dissolved oxygen concentrations. Because monomethylmercury (MMHg) production can be mediated by anaerobic bacteria, coastal lagoons are a potential source of biologically available MMHg that may be transported to the nearshore environment via submarine groundwater discharge. To evaluate the importance of coastal lagoons at the land-sea margin, we quantified total mercury (HgT) and MMHg concentrations in surface water and coastal seawater from six sites during dry and wet season conditions, including one storm event. Additionally, we conducted a tidal study at one lagoon in which we sampled surface water, seawater, and groundwater over a 10-hour period during a falling tide (+1.63 to 0.00 m). Groundwater was collected using a multi-port piezometer screened at depths ranging from 1 m to a few centimeters below the lagoon's sediment-water interface. This enabled us to characterize surface water - groundwater interaction. During wet season conditions, the average unfiltered HgT (U-HgT) concentration in surface water at the tidal study lagoon was 13 pM and did not fluctuate in response to tidal changes. Filtered (< 0.45 μm) HgT (F-HgT) concentrations in the lagoon were similar to U-HgT concentrations during high tide and decreased to 8 pM during low tide. Groundwater F-HgT concentrations were about 1.5 pM at a depth of 1 m and systematically increased at shallower depths, reaching approximately 6 pM near the surface. These data indicate F-HgT exchange between the lagoon and groundwater to a depth of at least 1 m

The effect of floods on sediment contamination in a microtidal coastal lagoon: the lagoon of Lesina, Italy.

PubMed

D'Adamo, Raffaele; Specchiulli, Antonietta; Cassin, Daniele; Botter, Margherita; Zonta, Roberto; Fabbrocini, Adele

2014-10-01

The effects on the microtidal lagoon of Lesina of runoff and the discharge of water and material from agricultural activities were investigated combining chemical analyses of pollutants [11 metals and 16 priority polycyclic aromatic compounds (PAHs)], determination of organic matter and grain size, and performance of innovative ecotoxicological tests. For metals, enrichment factors >3 for arsenic, nickel, and copper (Cu) were observed in the eastern zone of the lagoon, which is affected by nearby urban activities with discharge of water and domestic waste and by agricultural input with waters rich in fertilizers. Cu was correlated with no other metal, and its high concentrations (≤77 µg g(-1)) may result from the use of Cu-based fungicides in vineyards. Total PAHs (2,230 ± 3,150 ng g(-1)) displayed a wide range of concentrations with hot spots near freshwater inputs from the part of the catchment area exploited for wheat crops. Pyrolitic contamination also emerged, with higher-mass PAH congeners, such as asphalt, bitumen or coal, usually present in higher fractions as the dominant components. Ecotoxicological evaluations recorded moderate to high toxicity levels; the innovative MOT test bioassay showed good discriminatory ability because it identified a lagoon area whose inputs mainly depend on agricultural activities and which is impacted by metals rather than PAHs. Floods during periods of heavy rain and the discharge of water and material from agricultural activities may impact vulnerable systems, such as the lagoon of Lesina, where the presence of hot spots with remarkably high pollution values was observed.

Gastrointestinal parasites of canids, a latent risk to human health in Tunisia.

PubMed

Oudni-M'rad, Myriam; Chaâbane-Banaoues, Raja; M'rad, Selim; Trifa, Fatma; Mezhoud, Habib; Babba, Hamouda

2017-06-05

Although data on the parasite environmental contamination are crucial to implement strategies for control and treatment, information about zoonotic helminths is very limited in Tunisia. Contamination of areas with canid faeces harboring infective parasite elements represents a relevant health-risk impact for humans. The aim of this study was to assess the environmental contamination with eggs and oocysts of gastrointestinal parasites of dogs and wild canids in Tunisia with special attention to those that can be transmitted to humans. One thousand two hundred and seventy faecal samples from stray dogs and 104 from wild canids (red foxes and golden jackals) were collected from different geographical regions throughout Tunisia. The helminth eggs and protozoan oocysts were concentrated by sucrose flotation and identified by microscopic examination. The most frequently observed parasites in dog samples were Toxocara spp. (27.2%), E. granulosus (25.8%), and Coccidia (13.1%). For wild canid faeces, the most commonly encountered parasites were Toxocara spp. (16.3%) followed by Capillaria spp. (9.6%). The parasite contamination of dog faeces varied significantly from one region to another in function of the climate. To our knowledge, the study highlights for the first time in Tunisia a serious environmental contamination by numerous parasitic stages infective to humans. Efforts should be made to increase the awareness of the contamination risk of such parasites in the environment and implement a targeted educational program.

Sludge-Drying Lagoons: a Potential Significant Methane Source in Wastewater Treatment Plants.

PubMed

Pan, Yuting; Ye, Liu; van den Akker, Ben; Ganigué Pagès, Ramon; Musenze, Ronald S; Yuan, Zhiguo

2016-02-02

"Sludge-drying lagoons" are a preferred sludge treatment and drying method in tropical and subtropical areas due to the low construction and operational costs. However, this method may be a potential significant source of methane (CH4) because some of the organic matter would be microbially metabolized under anaerobic conditions in the lagoon. The quantification of CH4 emissions from lagoons is difficult due to the expected temporal and spatial variations over a lagoon maturing cycle of several years. Sporadic ebullition of CH4, which cannot be easily quantified by conventional methods such as floating hoods, is also expected. In this study, a novel method based on mass balances was developed to estimate the CH4 emissions and was applied to a full-scale sludge-drying lagoon over a three year operational cycle. The results revealed that processes in a sludge-drying lagoon would emit 6.5 kg CO2-e per megaliter of treated sewage. This would represent a quarter to two-thirds of the overall greenhouse gas (GHG) emissions from wastewater-treatment plants (WWTPs). This work highlights the fact that sludge-drying lagoons are a significant source of CH4 that adds substantially to the overall GHG footprint of WWTPs despite being recognized as a cheap and energy-efficient means of drying sludge.

Sero-epidemiological survey of Crimean-Congo hemorrhagic fever virus in Tunisia

PubMed Central

Wasfi, Fares; Dowall, Stuart; Ghabbari, Tayssir; Bosworth, Andrew; Chakroun, Mohamed; Varghese, Anitha; Tiouiri, Hanene; Ben Jemaa, Mounir; Znazen, Abir; Hewson, Roger; Zhioua, Elyes; Letaief, Amel

2016-01-01

Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne disease associated with a high case fatality rate and transmitted mainly by Hyalomma marginatum. The geographical distribution of H. marginatum covers most of the Western Mediterranean basin. We aimed to investigate whether CCHF virus (CCHFv) is circulating in Tunisia. Samples from unexplained acute febrile patients (n = 181) and a high risk group of humans, mainly slaughter workers (n = 38), were collected in the summer of 2014 and analyzed for exposure to CCHFv using serological tests and real-time RT-PCR. Ticks were collected from Northern and Southern Tunisia during May–June 2014 and examined for the presence of CCHFv by real-time RT-PCR. Of the 181 febrile patients, 5 showed only high titers of IgM suggesting a recent exposure to CCHFv. Among 38 slaughter workers, 2 had IgG anti-CCHFv responses yielding a seroprevalence of 5.2%. No CCHFv was detected in ticks and sera. Our results provide evidence of human exposure to CCHFv in Tunisia. PMID:26956221

Sero-epidemiological survey of Crimean-Congo hemorrhagic fever virus in Tunisia.

PubMed

Wasfi, Fares; Dowall, Stuart; Ghabbari, Tayssir; Bosworth, Andrew; Chakroun, Mohamed; Varghese, Anitha; Tiouiri, Hanene; Ben Jemaa, Mounir; Znazen, Abir; Hewson, Roger; Zhioua, Elyes; Letaief, Amel

2016-01-01

Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne disease associated with a high case fatality rate and transmitted mainly by Hyalomma marginatum. The geographical distribution of H. marginatum covers most of the Western Mediterranean basin. We aimed to investigate whether CCHF virus (CCHFv) is circulating in Tunisia. Samples from unexplained acute febrile patients (n = 181) and a high risk group of humans, mainly slaughter workers (n = 38), were collected in the summer of 2014 and analyzed for exposure to CCHFv using serological tests and real-time RT-PCR. Ticks were collected from Northern and Southern Tunisia during May-June 2014 and examined for the presence of CCHFv by real-time RT-PCR. Of the 181 febrile patients, 5 showed only high titers of IgM suggesting a recent exposure to CCHFv. Among 38 slaughter workers, 2 had IgG anti-CCHFv responses yielding a seroprevalence of 5.2%. No CCHFv was detected in ticks and sera. Our results provide evidence of human exposure to CCHFv in Tunisia. © F. Wasfi et al., published by EDP Sciences, 2016.

Redistribution of fallout radionuclides in Enewetak Atoll lagoon sediments by callianassid bioturbation.

PubMed

McMurtry, G M; Schneider, R C; Colin, P L; Buddemeier, R W; Suchanek, T H

The lagoon sediments of Enewetak Atoll in the Marshall Islands contain a large selection of fallout radionuclides as a result of 43 nuclear weapon tests conducted there between 1948 and 1958. Studies of the burial of fallout radionuclides have been conducted on the islands and in several of the large craters, but studies of their vertical distribution have been limited to about the upper 20 cm of the lagoon sediments. We have found elevated fallout radionuclide concentrations buried more deeply in the lagoon sediments and evidence of burrowing into the sediment by several species of callianassid ghost shrimp (Crustacea: Thalassinidea) which has displaced highly radioactive sediment. The burrowing activities of callianassids, which are ubiquitous on the lagoon floor, facilitate radionuclide redistribution and complicate the fallout radionuclide inventory of the lagoon.

Spatiotemporal variation of bacterial community composition and possible controlling factors in tropical shallow lagoons.

PubMed

Laque, Thaís; Farjalla, Vinicius F; Rosado, Alexandre S; Esteves, Francisco A

2010-05-01

Bacterial community composition (BCC) has been extensively related to specific environmental conditions. Tropical coastal lagoons present great temporal and spatial variation in their limnological conditions, which, in turn, should influence the BCC. Here, we sought for the limnological factors that influence, in space and time, the BCC in tropical coastal lagoons (Rio de Janeiro State, Brazil). The Visgueiro lagoon was sampled monthly for 1 year and eight lagoons were sampled once for temporal and spatial analysis, respectively. BCC was evaluated by bacteria-specific PCR-DGGE methods. Great variations were observed in limnological conditions and BCC on both temporal and spatial scales. Changes in the BCC of Visgueiro lagoon throughout the year were best related to salinity and concentrations of NO (3) (-) , dissolved phosphorus and chlorophyll-a, while changes in BCC between lagoons were best related to salinity and dissolved phosphorus concentration. Salinity has a direct impact on the integrity of the bacterial cell, and it was previously observed that phosphorus is the main limiting nutrient to bacterial growth in these lagoons. Therefore, we conclude that great variations in limnological conditions of coastal lagoons throughout time and space resulted in different BCCs and salinity and nutrient concentration, particularly dissolved phosphorus, are the main limnological factors influencing BCC in these tropical coastal lagoons.

An integrated Pan-European perspective on coastal Lagoons management through a mosaic-DPSIR approach

PubMed Central

Dolbeth, Marina; Stålnacke, Per; Alves, Fátima L.; Sousa, Lisa P.; Gooch, Geoffrey D.; Khokhlov, Valeriy; Tuchkovenko, Yurii; Lloret, Javier; Bielecka, Małgorzata; Różyński, Grzegorz; Soares, João A.; Baggett, Susan; Margonski, Piotr; Chubarenko, Boris V.; Lillebø, Ana I.

2016-01-01

A decision support framework for the management of lagoon ecosystems was tested using four European Lagoons: Ria de Aveiro (Portugal), Mar Menor (Spain), Tyligulskyi Liman (Ukraine) and Vistula Lagoon (Poland/Russia). Our aim was to formulate integrated management recommendations for European lagoons. To achieve this we followed a DPSIR (Drivers-Pressures-State Change-Impacts-Responses) approach, with focus on integrating aspects of human wellbeing, welfare and ecosystem sustainability. The most important drivers in each lagoon were identified, based on information gathered from the lagoons’ stakeholders, complemented by scientific knowledge on each lagoon as seen from a land-sea perspective. The DPSIR cycles for each driver were combined into a mosaic-DPSIR conceptual model to examine the interdependency between the multiple and interacting uses of the lagoon. This framework emphasizes the common links, but also the specificities of responses to drivers and the ecosystem services provided. The information collected was used to formulate recommendations for the sustainable management of lagoons within a Pan-European context. Several common management recommendations were proposed, but specificities were also identified. The study synthesizes the present conditions for the management of lagoons, thus analysing and examining the activities that might be developed in different scenarios, scenarios which facilitate ecosystem protection without compromising future generations. PMID:26776151

Mechanism of nitrogen removal in wastewater lagoon: a case study.

PubMed

Vendramelli, Richard A; Vijay, Saloni; Yuan, Qiuyan

2017-06-01

Ammonia being a nutrient facilitates the growth of algae in wastewater and causes eutrophication. Nitrate poses health risk if it is present in drinking water. Hence, nitrogen removal from wastewater is required. Lagoon wastewater treatment systems have become common in Canada these days. The study was conducted to understand the nitrogen removal mechanisms from the existing wastewater treatment lagoon system in the town of Lorette, Manitoba. The lagoon system consists of two primary aerated cells and two secondary unaerated cells. Surface samples were collected periodically from lagoon cells and analysed from 5 May 2015 to 9 November 2015. The windward and leeward sides of the ponds were sampled and the results were averaged. It was found that the free ammonia volatilization to the atmosphere is responsible for most of the ammonia removal. Ammonia and nitrate assimilation into biomass and biological growth in the cells appears to be the other mechanisms of nitrogen removal over the monitoring period. Factors affecting the nitrogen removal efficiency were found to be pH, temperature and hydraulic residence time. Also, the ammonia concentration in the effluent from the wastewater treatment lagoon was compared with the regulatory standard.

HPV Types and Variants Among Cervical Cancer Tumors in Three Regions of Tunisia

PubMed Central

KrennHrubec, Keris; Mrad, Karima; Sriha, Badreddine; Ben Ayed, Farhat; Bottalico, Danielle M.; Ostolaza, Janae; Smith, Benjamin; Tchaikovska, Tatyana; Soliman, Amr S.; Burk, Robert D.

2014-01-01

Cervical cancer is the second most common cancer among Tunisian women, and the incidence rates vary by region. Three Tunisian registries report age-standardized rates of 6.3/105 in the central region, 5.4/105 in the north, and 2.7/105 in the south. High-risk human papillomavirus (HPV) types and their variants differ in carcinogenic potential and geographic distribution. The HPV type and variant distribution could be a factor in the differing rates between regions of Tunisia. Tumor tissue was collected from 142 Tunisian cervical cancer patients. Demographic and reproductive characteristics of the patients were abstracted from cancer registry and hospital records. HPV type and variant analyses were performed using PCR-based Luminex and dot-blot hybridization assays. Eighty-three percent of tumors were infected with at least one HPV type. European variants of HPV16/18 were the most prevalent in tumors from all three regions, with all HPV18 infections and 64% of HPV16 infections being of European lineage. A higher frequency of HPV16 was present in Northern Tunisia (80%) than in Central (68%) or Southern Tunisia (50%) (P = 0.02). HPV18/45 was significantly more common in adenocarcinomas (50%) than in squamous cell carcinomas (11%) (P = 0.004). Frequent infection with European HPV variants most likely reflects the history of European migration to Tunisia. In addition to the importance of understanding the variants of HPV in Tunisia, behavioral and cultural attitudes towards screening and age-specific infection rates should be investigated to aid the development of future vaccination and HPV screening programs and policies. PMID:21328380

Exposure of resident sparrows to West Nile virus evidenced in South Tunisia.

PubMed

Hammouda, A; Lecollinet, S; Hamza, F; Nasri, I; Neb, A; Selmi, S

2015-12-01

During the last few years, several cases of West Nile virus (WNV) infection in humans have been reported in Tunisia. However, detailed information on WNV infection in wild birds, the primary amplifying host of WNV, are lacking. In this work, we investigated the exposure of wild sparrows (hybrid Passer domesticus × hispaniolensis) living in two oases in southern Tunisia (Gabès and Kébili oases) to WNV, through the detection of WNV-specific antibodies by using ELISA and microneutralization tests. In total, 208 birds were sampled (54 from Kébili, 154 from Gabès). Anti-WNV antibodies were detected in two birds, corresponding to an overall seroprevalence of 1%. There was no significant difference between the two sampled populations [1·85% (1/54) in Kébili, 0·65% (1/154) in Gabès]. These data provide indirect evidence of the exposure of resident sparrows in southern Tunisia to WNV.

Monitoring of dioxin-like, estrogenic and anti-androgenic activities in sediments of the Bizerta lagoon (Tunisia) by means of in vitro cell-based bioassays: contribution of low concentrations of polynuclear aromatic hydrocarbons (PAHs).

PubMed

Louiz, I; Kinani, S; Gouze, M-E; Ben-Attia, M; Menif, D; Bouchonnet, S; Porcher, J M; Ben-Hassine, O K; Aït-Aïssa, S

2008-09-01

We used an array of in vitro cell-based bioassays to assess dioxin-like, estrogenic and (anti-)androgenic activities in organic extracts of sediments from the Bizerta lagoon, one of the largest Tunisian lagoons subjected to various anthropogenic and industrial pressures. The sediments were sampled both in winter and summer 2006 in 6 stations differently impacted and in one reference station located in the seawards entrance of Ghar el Melh lagoon. Chemical analyses of the 16 priority PAHs showed that the sediments were low to moderately contaminated (2-537 ng/g dry weight). By using the estrogen- (MELN) and androgen-responsive (MDA-kb2) reporter cell lines, significant estrogenic and anti-androgenic activities were detected only in the Menzel Bourguiba (MB) site, the most contaminated site, both in winter and summer. By using 7-ethoxyresorufin-O-deethylase (EROD) induction in the fish PLHC-1 cell line after both 4 and 24 h of cell exposure, dioxin-like activities were detected in all analysed samples. Dioxin-like activities were higher after 4 h exposure, and varied according to the sites and the sampling season. While highly significant correlation was observed between bioassay- and chemical analyses-derived toxic equivalents (TEQs), PAHs accounted for only a small part (up to 4%) of the detected biological activities, suggesting that other readily metabolised EROD-inducing compounds were present. This study argues for the use of short time exposure to assess biological TEQs in low contaminated samples and provides new induction equivalent factors (IEF(4h)) for 16 PAHs in the PLHC-1 cell line. Finally, our results stress the need to further characterise the nature of organic chemical contamination as well as its long-term impacts on aquatic wildlife in the Bizerta lagoon.

Environmental quality of transitional waters: the lagoon of Venice case study.

PubMed

Micheletti, C; Gottardo, S; Critto, A; Chiarato, S; Marcomini, A

2011-01-01

The health status of European aquatic environments, including transitional waters such as coastal lagoons, is regulated by the Water Framework Directive (WFD), which requires the classification of the water bodies' environmental quality and the achievement of a good ecological status by 2015. In the Venice lagoon, a transitional water body located in the northeastern part of Italy, the achievement of a good ecological status is hampered by several anthropogenic and natural pressures, such as sediment and water chemical contamination, and sediment erosion. In order to evaluate the lagoon's environmental quality according to the WFD (i.e. 5 quality classes, from High to Bad), an integrated Weight-of-Evidence methodology was developed and applied to classify the quality of the lagoon water bodies, integrating biological, physico-chemical, chemical, ecotoxicological, and hydromorphological data (i.e. Lines of Evidence, LOE). The quality assessment was carried out in two lagoon habitat typologies (previously defined on the basis of morphological, sediment, and hydrodynamic characteristics) which were selected taking into account the ecological gradient from sea to land, and the differences in anthropogenic pressure and contamination levels. The LOE classification was carried out by using indicators scored by comparing site specific conditions to reference conditions measured in lagoon reference sites, or provided by local, national or European regulations (e.g. Environmental Quality Standards, EQS, for chemicals). Finally, the overall quality status for each water body was calculated by a probabilistic approach, i.e. by reporting the final result as the frequency distribution of quality classes. The developed procedure was applied by using data and information concerning selected LOE and collected from monitoring programs and research studies carried out in the last 15 years in the lagoon of Venice. A set of sampling stations characterized by spatially and temporally

Airport malaria: report of four cases in Tunisia.

PubMed

Siala, Emna; Gamara, Dhikrayet; Kallel, Kalthoum; Daaboub, Jabeur; Zouiten, Faiçal; Houzé, Sandrine; Bouratbine, Aïda; Aoun, Karim

2015-01-28

Four cases of airport malaria were notified for the first time in Tunisia during the summer of 2013. All patients were neighbours living within 2 km of Tunis International Airport. They had no history of travel to malarious countries, of blood transfusion or of intravenous drug use. Although malaria transmission had ceased in Tunisia since 1980, autochthonous infection by local Anopheles mosquitoes was initially considered. However, this diagnostic hypothesis was ruled out due to negative entomological survey and the absence of additional cases.All cases were caused by Plasmodium falciparum. Clinical presentation was severe (important thrombocytopaenia and parasitaemia), because of relatively important delay in diagnosis (average of seven days). This indicates the need to consider malaria while examining airport employees or people living near international airports presenting with fever of unknown origin. It also stresses the need for effective spraying of aircrafts coming from malarious areas.

Quantitative morphometric analysis for the tectonic characterisation of northern Tunisia.

NASA Astrophysics Data System (ADS)

Camafort, Miquel; Pérez-Peña, José Vicente; Booth-Rea, Guillermo; Ranero, César R.; Gràcia, Eulàlia; Azañón, José Miguel; Melki, Fetheddine; Ouadday, Mohamed

2016-04-01

Northern Tunisia is characterized by low deformation rates and low to moderate seismicity. Although instrumental seismicity reaches maximum magnitudes of Mw 5.5, some historical earthquakes have occurred with catastrophic consequences in this region. Aiming to improve our knowledge of active tectonics in Tunisia, we carried out both a quantitative morphometric analysis and field study in the north-western region. We applied different morphometric tools, like river profiles, knickpoint analysis, hypsometric curves and integrals and drainage pattern anomalies in order to differentiate between zones with high or low recent tectonic activity. This analysis helps identifying uplift and subsidence zones, which we relate to fault activity. Several active faults in a sparse distribution were identified. A selected sector was studied with a field campaign to test the results obtained with the quantitative analysis. During the fieldwork we identified geological evidence of recent activity and a considerable seismogenic potential along El Alia-Teboursouk (ETF) and Dkhila (DF) faults. The ETF fault could be responsible of one of the most devastating historical earthquakes in northern Tunisia that destroyed Utique in 412 A.D. Geological evidence include fluvial terraces folded by faults, striated and cracked pebbles, clastic dikes, sand volcanoes, coseismic cracks, etc. Although not reflected in the instrumental seismicity, our results support an important seismic hazard, evidenced by the several active tectonic structures identified and the two seismogenic faults described. After obtaining the current active tectonic framework of Tunisia we discuss our results within the western Mediterranean trying to contribute to the understanding of the western Mediterranean tectonic context. With our results, we suggest that the main reason explaining the sparse and scarce seismicity of the area in contrast with the adjacent parts of the Nubia-Eurasia boundary is due to its extended

Interannual and cyclone-driven variability in phytoplankton communities of a tropical coastal lagoon.

PubMed

Srichandan, Suchismita; Kim, Ji Yoon; Kumar, Abhishek; Mishra, Deepak R; Bhadury, Punyasloke; Muduli, Pradipta R; Pattnaik, Ajit K; Rastogi, Gurdeep

2015-12-15

One of the main challenges in phytoplankton ecology is to understand their variability at different spatiotemporal scales. We investigated the interannual and cyclone-derived variability in phytoplankton communities of Chilika, the largest tropical coastal lagoon in Asia and the underlying mechanisms in relation to environmental forcing. Between July 2012 and June 2013, Cyanophyta were most prolific in freshwater northern region of the lagoon. A category-5 very severe cyclonic storm (VSCS) Phailin struck the lagoon on 12th October 2013 and introduced additional variability into the hydrology and phytoplankton communities. Freshwater Cyanophyta further expanded their territory and occupied the northern as well as central region of the lagoon. Satellite remote sensing imagery revealed that the phytoplankton biomass did not change much due to high turbidity prevailing in the lagoon after Phailin. Modeling analysis of species-salinity relationship identified specific responses of phytoplankton taxa to the different salinity regime of lagoon. Copyright © 2015 Elsevier Ltd. All rights reserved.

Hydrodynamic framework of Saharan Triassic aquifers in South Tunisia and Algeria

NASA Astrophysics Data System (ADS)

Dhia, H. Ben; Chiarelli, A.

The main characteristics of the lower Triassic in the Saharan part of Tunisia are presented. This first study of the aquifer is made possible because of data available from numerous petroleum wells that exist in the region. The results show that the reservoir is of importance for either geothermal energy recovering or human water needs; especially since its salinity lies in the range 2 g/l to 60 g/l. Along the Tunisian-Llibyan frontier, because of its pressure and salinity (<3 g/l), the aquifer can be used for regional needs. The study also shows that the salinity gradient (SE-NW) increases orthogonally to the runoff direction (SW-NE). This phenomenon was unexpected and it is necessary to consider the aquifer in its regional North African framework and to include its Algerian part to understand it; when the salinity and potentiometric maps include both countries, a regional pattern is evident. Furthermore, a correspondence is noted between the salinity variations and the percentage of detritic elements in the reservoir. Salinity increases toward the NW, while the detritic elements decrease in that direction. Zones with salt content lower than 5 g/l seem to be related to good reservoirs and shales, that are rich in sands, and carbonates. The aquifer water supply is primarily linked to gravity flow and secondarily to compaction flow.

Reconstruction of historic sea ice conditions in a sub-Arctic lagoon

USGS Publications Warehouse

Petrich, Chris; Tivy, Adrienne C.; Ward, David H.

2014-01-01

Historical sea ice conditions were reconstructed for Izembek Lagoon, Bering Sea, Alaska. This lagoon is a crucial staging area during migration for numerous species of avian migrants and a major eelgrass (Zostera marina) area important to a variety of marine and terrestrial organisms, especially Pacific Flyway black brant geese (Branta bernicla nigricans). Ice cover is a common feature of the lagoon in winter, but appears to be declining, which has implications for eelgrass distribution and abundance, and its use by wildlife. We evaluated ice conditions from a model based on degree days, calibrated to satellite observations, to estimate distribution and long-term trends in ice conditions in Izembek Lagoon. Model results compared favorably with ground observations and 26 years of satellite data, allowing ice conditions to be reconstructed back to 1943. Specifically, periods of significant (limited access to eelgrass areas) and severe (almost complete ice coverage of the lagoon) ice conditions could be identified. The number of days of severe ice within a single season ranged from 0 (e.g., 2001) to ≥ 67 (e.g., 2000). We detected a slight long-term negative trend in ice conditions, superimposed on high inter-annual variability in seasonal aggregate ice conditions. Based on reconstructed ice conditions, the seasonally cumulative number of significant or severe ice days correlated linearly with mean air temperature from January until March. Further, air temperature at Izembek Lagoon was correlated with wind direction, suggesting that ice conditions in Izembek Lagoon were associated with synoptic-scale weather patterns. Methods employed in this analysis may be transferable to other coastal locations in the Arctic.

Dynamics of copper and zinc sedimentation in a lagooning system receiving landfill leachate.

PubMed

Guigue, Julien; Mathieu, Olivier; Lévêque, Jean; Denimal, Sophie; Steinmann, Marc; Milloux, Marie-Jeanne; Grisey, Hervé

2013-11-01

This study characterises the sediment dredged from a lagooning system composed of a settling pond and three lagoons that receive leachates from a municipal solid waste (MSW) landfill in France. Organic carbon, carbonate, iron oxyhydroxides, copper (Cu) and zinc (Zn) concentrations were measured in the sediment collected from upstream to downstream in the lagooning system. In order to complete our investigation of sedimentation mechanisms, leachates were sampled in both dry (spring) and wet (winter) seasonal conditions. Precipitation of calcite and amorphous Fe-oxyhydroxides and sedimentation of organic matter occurred in the settling pond. Since different distributions of Zn and Cu concentrations are measured in sediment samples collected downstream in the lagooning system, it is suggested that these elements were not distributed in a similar way in the leachate fractions during the first stage of treatment in the settling pond, so that their sedimentation dynamics in the lagooning system differ. In the lagoons, it was found that organic carbon plays a major role in Cu and Zn mobility and trapping. The presence of macrophytes along the edges provided an input of organic matter that enhanced Cu and Zn scavenging. This edge effect resulted in a two-fold increase in Cu and Zn concentrations in the sediment deposited near the banks of the lagoons, thus confirming the importance of vegetation for the retention of Cu and Zn in lagooning systems. Copyright © 2013 Elsevier Ltd. All rights reserved.

Temporal stability of otolith elemental fingerprints discriminates among lagoon nursery habitats

NASA Astrophysics Data System (ADS)

Tournois, Jennifer; Ferraton, Franck; Velez, Laure; McKenzie, David J.; Aliaume, Catherine; Mercier, Lény; Darnaude, Audrey M.

2013-10-01

The chemical composition of fish otoliths reflects that of the water masses that they inhabit. Otolith elemental compositions can, therefore, be used as natural tags to discriminate among habitats. However, for retrospective habitat identification to be valid and reliable for any adult, irrespective of its age, significant differences in environmental conditions, and therefore otolith signatures, must be temporally stable within each habitat, otherwise connectivity studies have to be carried out by matching year-classes to the corresponding annual fingerprints. This study investigated how various different combinations of chemical elements in otoliths could distinguish, over three separate years, between four coastal lagoon habitats used annually as nurseries by gilthead sea bream (Sparus aurata L.) in the Gulf of Lions (NW Mediterranean). A series of nine elements were measured in otoliths of 301 S. aurata juveniles collected in the four lagoons in 2008, 2010 and 2011. Percentages of correct re-assignment of juveniles to their lagoon of origin were calculated with the Random Forest classification method, considering every possible combination of elements. This revealed both spatial and temporal variations in accuracy of habitat identification, with correct re-assignment to each lagoon ranging from 44 to 99% depending on the year and the lagoon. There were also annual differences in the combination of elements that provided the best discrimination among the lagoons. Despite this, when the data from the three years were pooled, a combination of eight elements (B, Ba, Cu, Li, Mg, Rb, Sr and Y) provided greater than 70% correct re-assignment to each single lagoon, with a multi-annual global accuracy of 79%. When considering the years separately, discrimination accuracy with these elemental fingerprints was above 90% for 2008 and 2010. It decreased to 61% in 2011, when unusually heavy rainfall occurred, which presumably reduced chemical differences among several of the

[Epidemiological transition and cardiovascular risk factors in Tunisia].

PubMed

Ghannem, H; Fredj, A H

1997-09-01

In Tunisia a growing extension of chronic diseases has resulted from the environmental and behavioral changes such as the adoption of new dietary habits, sedentarity habitat, stress of urbanization and work conditions. To illustrate this trend, we undertook a household epidemiologic survey of a representative sample of the adult urban population of Soussa (n = 957) to assess the main cardiovascular risk factors except the lipid profile distribution. This study showed a high prevalence of hypertension (> 160/95 mm Hg): 18.8% with an adjusted rate of 15.6%. History of diabetes 10.2%, obesity (BMI > 30) 27.7% significantly higher in women (34.4%), android obesity 36%, smoking habits 21.5% significantly higher in men (61.4%). With this risk factor profile, Tunisia has to implement a national strategy of primary prevention and heart health promotion in addition to the efforts recently made in secondary prevention of some chronic diseases such as hypertension and diabetes.

Biogeochemical responses of shallow coastal lagoons to Climate Change

NASA Astrophysics Data System (ADS)

Brito, A.; Newton, A.; Tett, P.; Fernandes, T.

2009-04-01

The importance of climate change and global warming in the near future is becoming consensual within the scientific community (e.g. Kerr et al., 2008; Lloret et al., 2008). The surface temperature and sea level have increased during the last few years in the northern hemisphere (IPCC, 2007). Predictions for future changes include an increase of surface temperature and sea level for Europe. Moreover, the global warming phenomenon will also change the hydrological cycle and increase precipitation in northern and central Europe (IPCC, 2007). Sea level rise already threatens to overwhelm some lagoons, such as Venice and Moroccan lagoons (Snoussi et al., 2008). Shallow coastal lagoons are some of the most vulnerable systems that will be impacted by these changes (Eisenreich, 2005). Environmental impacts on coastal lagoons include an increase of water turbidity and therefore light attenuation. If these effects are strong enough, the lighted bottoms of shallow lagoons may loose a significant part of the benthic algal community. These communities are highly productive and are essential to control nutrient dynamics of the system by uptaking large amounts of nutrients both from the water column and from the sediments. A decrease in benthic algal communities and photosynthetic oxygen production will also contribute to increasing the vulnerability of the lagoons to hypoxia and anoxia. The flux of nutrients such as phosphate from the sediments may increase dramatically, further disrupting the nutrient balance and condition and promoting cyanobacterial blooms. Microbial activity is temperature dependent, therefore, the increase of temperature will increase the concentrations of ammonium within sediments. The release of phosphate and silicate will also increase with temperature. Coastal lagoons are valuable ecosystems and may be severely impacted, both ecologically and economically, by global change. Shallow coastal lagoons should be considered as sentinel systems and should be

[Intestinal parasitosis among non-permanent resident students in Tunisia: a review of 23 years of monitoring in the department of Parasitology-Mycology at the Rabta Hospital of Tunisia].

PubMed

Dridi, Kalthoum; Fakhfakh, Najla; Belhadj, Sleh; Kaouech, Emira; Kallel, Kalthoum; Chaker, Emna

2015-07-01

In order to fight digestive parasitism in Tunisia, a national program of surveillance of non-permanent resident students in Tunisia has been found to detect these parasitosis in this target population. To determine the prevalence of intestinal parasitosis among non-permanent resident students in Tunisia, to identify the different parasitic species founded and to show the interest of this screening. During a period of 23 years (1990-2012), 7386 parasitological examinations of stools has been made among students essentially from or had visited tropical Africa, Maghreb and Middle-East, at the laboratory of Parasitology-Mycology at the Rabta Hospital of Tunis. The prevalence of intestinal parasitism found was 34.45% (i.e. 2545 infested students). Among the protozoa that have been isolated in the majority of cases (78.75%), amoebae were most frequently found (86.4%) represented mainly by Entamoeba coli and Endolimax nanus in respectively, 25.62 and 23.33% of parasites isolated; while Entamoeba histolytica/dispar, only pathogenic Amoeba was found in 8.05% of the total of parasites isolated. Regarding helminths, found in 21.25% of parasites isolated, Ankylostome was predominant (34.5%) represented by the species of Necator americanus. A single case of Ancylostom duodenale has been isolated. Among the identified parasite species, 38.7% were known parasitic pathogens for humans. These results note the interest of the control of the non-permanent resident students in Tunisia. The precocious tracking and treatment of affected subjects permits to avoid the introduction and the dissemination of parasites already rare and virulent strains in our country.

Export of health services from developing countries: the case of Tunisia.

PubMed

Lautier, Marc

2008-07-01

Although the subject of health services exports by developing countries has been much discussed, the phenomenon is still in its early stage, and its real implications are not yet clear. Given the rapid development in this area, little empirical data are available. This paper aims to fill this gap by providing reliable data on consumption of health services abroad (GATS mode 2 of international service supply). It starts by assessing the magnitude of the volume of international trade in health services. This is followed by an in-depth analysis of the case of Tunisia based on an original field research. Because of the high quality of its health sector and its proximity with Europe, Tunisia has the highest export potential for health services in the Middle-East and North Africa (MENA) Region. Health services exports may represent a quarter of Tunisia's private health sector output and generate jobs for 5000 employees. If one takes into account tourism expenses by the incoming patient (and their relatives), these exports contribute to nearly 1% of the country's total exports. Finally, this case study highlights the regional dimension of external demand for health services and the predominance of South-South trade.

Molecular prevalence and genetic characterization of piroplasms in dogs from Tunisia.

PubMed

Rjeibi, Mohamed R; Amairia, Safa; Rouatbi, Mariem; Ben Salem, Fatma; Mabrouk, Moez; Gharbi, Mohamed

2016-10-01

In this study, the prevalence of piroplasms in dogs was assessed using polymerase chain reaction (PCR) to identify Babesia and Theileria species in 200 dogs from Northern and Central Tunisia between spring and autumn 2014. The overall molecular prevalence for piroplasms was 14·5% ± 0·05 (29/200); PCR detected 2 species, namely Babesia vogeli and Theileria annulata with an overall prevalence of 12·5 ± 0·04 and 2% ± 0·02, respectively. No differences in the molecular prevalences of B. vogeli were revealed for age and sex (P > 0·05). The molecular prevalence of B. vogeli was significantly higher in central Tunisia (26·5% ± 0·01) compared with the North (9·6% ± 0·04) (P 0·05). Comparison of the partial sequences of 18S rRNA and Tams 1 genes confirmed the presence of 2 novel B. vogeli and T. annulata genotypes. This is the first molecular detection of T. annulata and genetic characterization of dogs' piroplasms in Tunisia. Further studies are needed to better assess the epidemiological feature of piroplasms infection in North Africa.

Characterization of a Colletotrichum population causing anthracnose disease on Olive in northern Tunisia.

PubMed

Chattaoui, M; Raya, M C; Bouri, M; Moral, J; Perez-Rodriguez, M; Trapero, A; Msallem, M; Rhouma, A

2016-05-01

To phenotypically, physiologically and molecularly characterize the causal agent of olive anthracnose in the northern Tunisia and to study its genetic variability and pathogenicity. A total of 43 isolates were obtained from symptomatic olives collected from four regions in northern Tunisia. A range of morphological and physiological characteristics was recorded; and a phylogenetic study, based on the sequence analysis of both internal transcribed spacers and TUB2 gene regions, was performed. Of the 43 isolates, 41 were identified as Colletotrichum acutatum s.s, and only two were affiliated to Colletotrichum gloeosporioides s.s. Two more representative Spanish isolates, included for comparison, were identified as Colletotrichum godetiae. Using six inter-simple-sequence-repeat markers, homogeneity between isolates from different locations and within the same species was recorded. In pathogenicity and virulence studies, C. gloeosporioides s.s was found to be less virulent, while the Spanish C. godetiae isolate was significantly more virulent than the Tunisian C. acutatum s.s. Olive anthracnose in the North of Tunisia is mainly caused by C. acutatum s.s species. This is the first study of olive anthracnose in Tunisia, which combines both phenotypic and molecular approaches. Colletotrichum acutatum s.s group was recorded for the first time in the country as the causal agent of olive anthracnose. © 2016 The Society for Applied Microbiology.

LANDSAT imagery of the Venetian Lagoon: A multitemporal analysis

NASA Technical Reports Server (NTRS)

Alberotanza, L.; Zandonella, A. (Principal Investigator)

1980-01-01

The use of LANDSAT multispectral scanner images from 1975 to 1979 to determine pollution dispersion in the central basin of the lagoon under varying tidal conditions is described. Images taken during the late spring and representing both short and long range tidal dynamics were processed for partial haze removal and removal of residual striping. Selected spectral bands were correlated to different types of turbid water. The multitemporal data was calibrated, classified considering sea truth data, and evaluated. The classification differentiated tide diffusion, algae belts, and industrial, agricultural, and urban turbidity distributions. Pollution concentration is derived during the short time interval between inflow and outflow and from the distance between the two lagoon inlets and the industrial zones. Increasing pollution of the lagoon is indicated.

Eutrophication Process on Coastal Lagoons of North of Sinaloa, Mexico

NASA Astrophysics Data System (ADS)

Escobedo-Urias, D.; Martinez-Lopez, A.

2007-05-01

Coastal ecosystems in the Gulf of California support diverse and important fisheries and are reservoirs of great biological diversity. In northern Sinaloa, population growth and development, as well as increased use of these natural systems for recreation, has substantially increased the pressure placed upon marine resources. Discharge of untreated wastewaters generated by diverse human activities has been notably altered its health and integrity, principally along the lagoon's eastern shore In the late 60s, agriculture moved into a dominant role in coastal northern Sinaloa. The coastal plain encompasses more than 200,000 hectares under cultivation that now introduces large amounts of organic material, pesticides, heavy metals, and fertilizers into the lagoon systems of Topolobampo and San Ignacio-Navachiste-Macapule System at drainage discharge points and a minor grade in Colorado Lagoon. These lagoons are shallow and exhibit low water quality, lost of lagoon depth, presence of toxic substances (heavy metals) near the discharge points of wastewaters, and presence of harmful algal blooms. With the aim of evaluate the nutrients loadings (wastewaters, groundwaters) and their effects on the coastal lagoons of north of Sinaloa, the preliminary analysis of the physical, chemical and biologic variables data series are analyzed. From 1987-2007 eutrophication process is identified in Topolobampo Complex show increase tendency in annual average concentrations of DIN (Dissolved Inorganic Nitrogen= NO2+NO3) from 0.5 μ M in 1987 to 2.7 μ M in 2006. Trophic Index (TRIX) values, low nutrient ratios (N: P and N: Si) and the phytoplanktonic community structure support this result. Preliminary results of nutrients loadings show a mayor contribution of wastewaters into the coastal zone.

Copper complexation capacity in surface waters of the Venice Lagoon.

PubMed

Delgadillo-Hinojosa, Francisco; Zirino, Alberto; Nasci, Cristina

2008-10-01

Total copper (Cu(T)), copper ion activity (pCu) and the copper complexation capacity (CuCC) were determined in samples of seawater collected in July 2003 from the Venice Lagoon. Cu(T) and CuCC showed considerable spatial variability: Cu(T) ranged from 1.8 to 70.0nM, whereas the CuCC varied from 195 to 573nM. pCu values varied from 11.6 to 12.6 and are consistent with those previously reported in estuarine and coastal areas (10.9-14.1). The range of Cu(T) values compares well with those reported in the past in the lagoon and in the adjacent Adriatic Sea. The highest concentrations of Cu(T) were found in samples collected near the industrial area of Porto Marghera, whereas the lowest were measured near the Chioggia and Malamocco inlets, where an intense tidally-driven renewal of seawater takes place. Although CuCC showed a high degree of spatial variability, the values recorded in the Venice Lagoon are comparable to those reported in other estuarine systems. In addition, CuCC was positively correlated with dissolved organic carbon (DOC), suggesting that organic ligands responsible for Cu complexation are part of the bulk organic matter pool in the lagoon. The CuCC:Cu(T) molar ratio was, on average 55:1, indicating that a large excess of complexation capacity exists in the Venice Lagoon. The high levels of CuCC and the narrow range of pCu indicates the importance of the role played by organic ligands in controlling the free ion Cu concentrations in the lagoon, and as a consequence, regulating its availability and/or toxicity.

Hydrology and Salt Balance in a Large, Hypersaline Coastal Lagoon: Lagoa de Araruama, Brazil

NASA Astrophysics Data System (ADS)

Kjerfve, Björn; Schettini, C. A. F.; Knoppers, Bastiaan; Lessa, Guilherme; Ferreira, H. O.

1996-06-01

Lagoa de Araruama in the state of Rio de Janeiro, Brazil, is a hypersaline coastal lagoon as a result of semi-arid climate conditions, a small drainage basin and a choked entrance channel. The lagoon has been continuously hypersaline for at least 4·5 centuries, but the mean salinity has varied substantially. It has recently decreased from 57 to 52 as indicated by density (salinity) measurements between 1965 and 1990. Analysis of more than 20 years of salinity time series data, in addition to monthly lagoon cruises to measure the spatial salinity distribution, indicate that the lagoon salinity largely fluctuates in response to the difference between evaporation and precipitation. The major factor explaining the long-term trend of decreasing salinity in the lagoon is the constant pumping of 1 m 3s -1of freshwater to the communities surrounding the lagoon from an adjacent watershed, and subsequent discharge of this water into Lagoa de Araruama. The net salt budget is primarily a balance between the advective import of salt from the coastal ocean and eddy diffusive export of salt to the ocean, although the extensive mining of salt from the lagoon during past decades is also a small but significant contribution to the salt budget. The flushing half-life is proposed as a useful time scale of water exchange, is calculated based on a combination of hydrological and tidal processes, and is excellent for comparison of lagoons and assessing water quality changes. The flushing half-life measures 83·5 days for Lagoa de Araruama, considerably longer than for most other coastal lagoons. The proposed dredging of a second ocean channel to Lagoa de Araruama is probably not a good idea. It is likely to accelerate the decrease of lagoon salinity and somewhat improve the lagoon water exchange. At the same time, this will eliminate the apparent buffering capacity provided by the hypersaline environment, and thus may potentially cause water quality problems.

Consistency of temporal and habitat-related differences among assemblages of fish in coastal lagoons

NASA Astrophysics Data System (ADS)

Gray, Charles A.; Rotherham, Douglas; Johnson, Daniel D.

2011-12-01

The consistency of habitat-related differences in coastal lagoon fish assemblages was assessed across different spatial and temporal scales. Multimesh gillnets were used to sample assemblages of fish on a monthly basis for 1-year in three habitats (shallow seagrass, shallow bare and deep substrata) at two locations (>1 km apart), in each of two coastal lagoons (approximately 500 km apart), in southeastern Australia. A total of 48 species was sampled with 34 species occurring in both lagoons and in all three habitats; species caught in only one lagoon or habitat occurred in low numbers. Ten species dominated assemblages and accounted for more than 83% of all individuals sampled. In both lagoons, assemblages in the deep habitat consistently differed to those in the shallow strata (regardless of habitat). Several species were caught more frequently or in larger numbers in the deep habitat. Assemblages in the two shallow habitats did not differ consistently and were dominated by the same species and sizes of fish, possibly due to habitat heterogeneity and the scale and method of sampling. Within each lagoon, very few between location differences in assemblages within each habitat were observed. Consistent differences in assemblages were detected between lagoons for the shallow bare and deep habitats, indicating there were some intrinsic differences in ichthyofauna between lagoons. Assemblages in spring differed to those in summer, which differed to those in winter for the shallow bare habitat in both lagoons, and the deep habitat in only one lagoon. Fish-habitat relationships are complex and differences in the fish fauna between habitats were often temporally inconsistent. This study highlights the need for greater testing of habitat relationships in space and time to assess the generality of observations and to identify the processes responsible for structuring assemblages.

Aptian-Albian boundary in Central Southern Atlas of Tunisia: New tectono-sedimentary facts

NASA Astrophysics Data System (ADS)

Ghanmi, Mohamed Abdelhamid; Barhoumi, Amine; Ghanmi, Mohamed; Zargouni, Fouad

2017-08-01

The Aptian-Albian boundary preserves one of the most important events in Central-Southern Atlas of Tunisia, which belongs to the Southern Tethyan margin. A major sedimentary break was recorded between Early Aptian and Albian series in Bouhedma-Boudouaou Mountains. This major hiatus probably linked to the ''Austrian phase'' and to the Aptian and Albian ''Crisis'' testify a period of major tectonic events. In this paper, field observations on the Mid-Cretaceous stratigraphy combined with seismic profile interpretation were used for the first time to characterize the Aptian-Albian boundary in Central-Southern Atlas of Tunisia. Our new results reveal that Aptian-Albian boundary marks a critical interval not only in Maknassy-Mezzouna orogenic system but also in the Tunisian Atlas. Furthermore, Aptian-Albian series outcrop is marked by the important sedimentary gaps as well as a dramatic thickness change from West to East and predominately from North to South. This is linked to the extensional tectonic features which characterize all the Central-Southern Atlas of Tunisia.

The environment of south-central Tunisia as observed on Landsat scene 206/036

USGS Publications Warehouse

Grolier, M.J.; Schultejann, P.A.

1982-01-01

One Landsat image in south-central Tunisia was analyzed to demonstrate the application of remote-sensing technology to regional development. A preliminary analysis included I) major landscape features; 2) gypsum-encrusted soils; and 3) phosphate-bearing beds exposed in the Gafsa mining district. The products specifically used for this report include: 1) A false-color composite (FCC), which had been linearly stretched to enhance contrast, and to which a modulation transfer function correction (a high-pass filter 3 pixels by 3 pixels wide) had been applied to enhance fine topographic relief. 2) A sinusoidally stretched false-color composite, on which mappable gypsum-encrusted soils and saline soils are detectable in greater detail than on the existing soil map of Tunisia at 1:500,000 scale. 3) A sinusoidally stretched band-ratio false-color composite, from which a thematic map of most phosphate-bearing beds in the Gafsa mining district was prepared. Recommendations for future Landsat image interpretation in Tunisia are offered.

Sustainability assessment of traditional fisheries in Cau Hai lagoon (South China Sea).

PubMed

Marconi, Michele; Sarti, Massimo; Marincioni, Fausto

2010-01-01

Overfishing and progressive environmental degradation of the Vietnamese Cau Hai coastal lagoon appear to be threatening the ecological integrity and water quality of the largest estuarine complex of Southeast Asia. This study assessed the relationships between the density of traditional fisheries and organic matter sedimentary contents in Cau Hai lagoon. Data revealed that the density of stake traps (the most common fishing gear used in this lagoon), decreasing hydrodynamic energy in shallow water, causes the accumulation of a large fraction of organic matter refractory to degradation. The relationship between biopolymeric carbon (a proxy of availability of organic matter) and stake traps density fits a S-shape curve. The logistic equation calculated a stake traps density of 90 m of net per hectare, as the threshold over which maximum accumulation of organic matter occurs in Cau Hai. With such level of stake trap density, and assuming a theoretical stationary status of the lagoon, the time necessary for the system to reach hypoxic conditions has been calculated to be circa three weeks. We recommend that this density threshold should not be exceeded in the Cau Hai lagoon and that further analyses of organic loads in the sediment should be conducted to monitor the trophic conditions of this highly eutrophicated lagoon. 2010 Elsevier Ltd. All rights reserved.

Microbial community analysis of swine wastewater anaerobic lagoons by next-generation DNA sequencing.

PubMed

Ducey, Thomas F; Hunt, Patrick G

2013-06-01

Anaerobic lagoons are a standard practice for the treatment of swine wastewater. This practice relies heavily on microbiological processes to reduce concentrated organic material and nutrients. Despite this reliance on microbiological processes, research has only recently begun to identify and enumerate the myriad and complex interactions that occur in this microbial ecosystem. To further this line of study, we utilized a next-generation sequencing (NGS) technology to gain a deeper insight into the microbial communities along the water column of four anaerobic swine wastewater lagoons. Analysis of roughly one million 16S rDNA sequences revealed a predominance of operational taxonomic units (OTUs) classified as belonging to the phyla Firmicutes (54.1%) and Proteobacteria (15.8%). At the family level, 33 bacterial families were found in all 12 lagoon sites and accounted for between 30% and 50% of each lagoon's OTUs. Analysis by nonmetric multidimensional scaling (NMS) revealed that TKN, COD, ORP, TSS, and DO were the major environmental variables in affecting microbial community structure. Overall, 839 individual genera were classified, with 223 found in all four lagoons. An additional 321 genera were identified in sole lagoons. The top 25 genera accounted for approximately 20% of the OTUs identified in the study, and the low abundances of most of the genera suggests that most OTUs are present at low levels. Overall, these results demonstrate that anaerobic lagoons have distinct microbial communities which are strongly controlled by the environmental conditions present in each individual lagoon. Published by Elsevier Ltd.

Future evolution of a tidal inlet due to changes in wave climate, Sea level and lagoon morphology (Óbidos lagoon, Portugal)

NASA Astrophysics Data System (ADS)

Bruneau, Nicolas; Fortunato, André B.; Dodet, Guillaume; Freire, Paula; Oliveira, Anabela; Bertin, Xavier

2011-11-01

Tidal inlets are extremely dynamic, as a result of an often delicate balance between the effects of tides, waves and other forcings. Since the morphology of these inlets can affect navigation, water quality and ecosystem dynamics, there is a clear need to anticipate their evolution in order to promote adequate management decisions. Over decadal time scales, the position and size of tidal inlets are expected to evolve with the conditions that affect them, for instance as a result of climate change. A process-based morphodynamic modeling system is validated and used to analyze the effects of sea level rise, an expected shift in the wave direction and the reduction of the upper lagoon surface area by sedimentation on a small tidal inlet (Óbidos lagoon, Portugal). A new approach to define yearly wave regimes is first developed, which includes a seasonal behavior, random inter-annual variability and the possibility to extrapolate trends. Once validated, this approach is used to produce yearly time series of wave spectra for the present and for the end of the 21st century, considering the local rotation trends computed using hindcast results for the past 57 years. Predictions of the mean sea level for 2100 are based on previous studies, while the bathymetry of the upper lagoon for the same year is obtained by extrapolation of past trends. Results show, and data confirm, that the Óbidos lagoon inlet has three stable configurations, largely determined by the inter-annual variations in the wave characteristics. Both sea level rise and the reduction of the lagoon surface area will promote the accretion of the inlet. In contrast, the predicted rotation of the wave regime, within foreseeable limits, will have a negligible impact on the inlet morphology.

Hepatitis E virus genotypes 1 and 3 in wastewater samples in Tunisia.

PubMed

Béji-Hamza, A; Hassine-Zaafrane, M; Khélifi-Gharbi, H; Della Libera, S; Iaconelli, M; Muscillo, M; Petricca, S; Ciccaglione, A R; Bruni, R; Taffon, S; Aouni, M; La Rosa, G

2015-01-01

Hepatitis E represents an important public-health concern throughout the world. It is one of the leading causes of hepatitis in North Africa, Asia and the Middle East. In Tunisia, the true burden of HEV infection is still unknown. The objectives of the present study were to assess the occurrence of hepatitis E virus in Tunisia through the monitoring of urban sewage and to characterize the strains identified using molecular assays. A total of 150 sewage samples (raw and treated) were collected from three wastewater treatment plants located in the regions of Monastir and Mahdia and analyzed by nested RT-PCR using a qualitative assay targeting the methyltransferase gene in ORF1. Of these, only three samples (2 %) were found to be positive for HEV, one belonging to genotype 1 and two to genotype 3. The results of the present study indicate a low level of virus excretion among the Tunisian population. Both genotypes 1 and 3 are circulating in this country, however, possibly causing sporadic infections. The presence of the zoonotic genotype 3, known to be transmitted to humans mainly by swine and demonstrated in Tunisia for the first time in this work, raises the question of possible reservoir species, since pork products are not consumed in this country, pigs are not bred, and wild boar is not endemic. Further studies will be needed to gather information on the occurrence and diversity of HEV strains circulating among humans and animals in Tunisia, and on possible animal reservoirs.

Ne-20/Ne-22 in the Martian Atmosphere: New Evidence from Martian Meteorites

NASA Technical Reports Server (NTRS)

Park, J.; Nyquist, L. E.; Herzog, G. F.; Nagao, K.; Mikouchi, T.; Kusakabe, M.

2017-01-01

Analyses of Ne trapped in "pods" of impact melt in the Elephant Moraine 79001 (EET 79001) Martian meteorite led to suggest (Ne-20/Ne-22) approx.10 in the Martian atmosphere (MA). In contrast, obtained trapped (Ne-20/Ne-22)Tr approx.7 from an impact melt vein in Yamato 793605 (Y-793605) and concluded that the isotopic composition of Martian Ne remained poorly defined. A "pyroxene-rich" separate from Dhofar 378 (Dho 378) analyzed gave a comparatively high trapped Ne concentration and (Ne-20/Ne-22) = 7.3+/-0.2 in agreement with the Y-793605 value. We explore the hypothesis that Martian Ne was trapped in the Dho 378 meteorite in a manner similar to entrapment of terrestrial Ne in tektites strengthening the "Martian atmosphere" interpretation. We also report new data for Northwest Africa 7034 (NWA 7034) that are consistent with the Ne data for Dho 378.

Groundwater and porewater as a major source of alkalinity to a fringing coral reef lagoon (Muri Lagoon, Cook Islands)

NASA Astrophysics Data System (ADS)

Cyronak, T.; Santos, I. R.; Erler, D. V.; Eyre, B. D.

2012-11-01

To better predict how ocean acidification will affect coral reefs, it is important to understand how biogeochemical cycles on reefs alter carbonate chemistry over various temporal and spatial scales. This study quantifies the contribution of fresh groundwater discharge (as traced by radon) and shallow porewater exchange (as quantified from advective chamber incubations) to total alkalinity (TA) dynamics on a fringing coral reef lagoon along the southern Pacific island of Rarotonga over a tidal and diel cycle. Benthic alkalinity fluxes were affected by the advective circulation of water through permeable sediments, with net daily flux rates of carbonate alkalinity ranging from -1.55 to 7.76 mmol m-2 d-1, depending on the advection rate. Submarine groundwater discharge (SGD) was a source of TA to the lagoon, with the highest flux rates measured at low tide, and an average daily TA flux of 1080 mmol m-2 d-1. Both sources of TA were important on a reef wide basis, although SGD acted solely as a delivery mechanism of TA to the lagoon, while porewater advection was either a sink or source of TA dependant on the time of day. On a daily basis, groundwater can contribute approximately 70% to 80% of the TA taken up by corals within the lagoon. This study describes overlooked sources of TA to coral reef ecosystems that can potentially alter water-column carbonate chemistry. We suggest that porewater and groundwater fluxes of TA should be taken into account in ocean acidification models in order to properly address changing carbonate chemistry within coral reef ecosystems.

Residence times in a hypersaline lagoon: Using salinity as a tracer

NASA Astrophysics Data System (ADS)

Mudge, Stephen M.; Icely, John D.; Newton, Alice

2008-04-01

Generally the waters of the Ria Formosa Lagoon, Portugal have a short residence time, in the order of 0.5 days (Tett, P., Gilpin, L., Svendsen, H., Erlandsson, C.P., Larsson, U., Kratzer, S., Fouilland, E., Janzen, C., Lee, J., Grenz, C., Newton, A., Ferreira, J.G., Fernandes, T., Scory, S., 2003. Eutrophication and some European waters of restricted exchange. Continental Shelf Research 23, 1635-1671). This estimation is based on the measurements of currents and the modelling of water exchange at the outlets to the ocean. However, observations of the temperature and salinity in the inner channels imply that residence time is greater in these regions of the lagoon. To resolve this apparent contradiction, spatial measurements of the temperature and salinity were made with a meter for conductivity, temperature and depth along the principal channels of the western portion of the lagoon, with a sampling frequency of two per second. Evaporation rates of 5.4 mm day -1 were measured in a salt extraction pond adjacent to the lagoon and used to determine the residence time through salinity differences with the incoming seawater. In June 2004, the water flooding in from the ocean had an average salinity of 36.07 which contrasted with a maximum of 37.82 at mid ebb on a spring tide, corresponding to a residence time of >7 days; the mean residence time was 2.4 days. As the tide flooded into the channels, the existing water was advected back into the lagoon. Although there was a small amount of mixing with water from another inlet, the water body from the inner lagoon essentially remained distinct with respect to temperature and salinity characteristics. The residence time of the water was further prolonged at the junction between the main channels, where distinct boundaries were observed between the different water masses. As the water ebbed out, the shallow Western Channel was essentially isolated from the rest of the outer lagoon, and the water from this channel was forced

Paleozoic oil/gas shale reservoirs in southern Tunisia: An overview

NASA Astrophysics Data System (ADS)

Soua, Mohamed

2014-12-01

During these last years, considerable attention has been given to unconventional oil and gas shale in northern Africa where the most productive Paleozoic basins are located (e.g. Berkine, Illizi, Kufra, Murzuk, Tindouf, Ahnet, Oued Mya, Mouydir, etc.). In most petroleum systems, which characterize these basins, the Silurian played the main role in hydrocarbon generation with two main 'hot' shale levels distributed in different locations (basins) and their deposition was restricted to the Rhuddanian (Lllandovery: early Silurian) and the Ludlow-Pridoli (late Silurian). A third major hot shale level had been identified in the Frasnian (Upper Devonian). Southern Tunisia is characterized by three main Paleozoic sedimentary basins, which are from North to South, the southern Chotts, Jeffara and Berkine Basin. They are separated by a major roughly E-W trending lower Paleozoic structural high, which encompass the Mehrez-Oued Hamous uplift to the West (Algeria) and the Nefusa uplift to the East (Libya), passing by the Touggourt-Talemzane-PGA-Bou Namcha (TTPB) structure close to southern Tunisia. The forementioned major source rocks in southern Tunisia are defined by hot shales with elevated Gamma ray values often exceeding 1400 API (in Hayatt-1 well), deposited in deep water environments during short lived (c. 2 Ma) periods of anoxia. In the course of this review, thickness, distribution and maturity maps have been established for each hot shale level using data for more than 70 wells located in both Tunisia and Algeria. Mineralogical modeling was achieved using Spectral Gamma Ray data (U, Th, K), SopectroLith logs (to acquire data for Fe, Si and Ti) and Elemental Capture Spectroscopy (ECS). The latter technique provided data for quartz, pyrite, carbonate, clay and Sulfur. In addition to this, the Gamma Ray (GR), Neutron Porosity (ΦN), deep Resistivity (Rt) and Bulk Density (ρb) logs were used to model bulk mineralogy and lithology. Biostratigraphic and complete

Subtidal hydrodynamics in a tropical lagoon: A dimensionless numbers approach

NASA Astrophysics Data System (ADS)

Tenorio-Fernandez, L.; Valle-Levinson, A.; Gomez-Valdes, J.

2018-01-01

Observations in a tropical lagoon of the Yucatan peninsula motivated a non-dimensional number analysis to examine the relative influence of tidal stress, density gradients and wind stress on subtidal hydrodynamics. A two-month observation period in Chelem Lagoon covered the transition from the dry to the wet season. Chelem Lagoon is influenced by groundwater inputs and exhibits a main sub-basin (central sub-basin), a west sub-basin and an east sub-basin. Subtidal hydrodynamics were associated with horizontal density gradients that were modified seasonally by evaporation, precipitation, and groundwater discharge. A tidal Froude number (Fr0), a Wedderburn number (W), and a Stress ratio (S0) were used to diagnose the relative importance of dominant subtidal driving forces. The Froude number (Fr0) compares tidal forcing and baroclinic forcing through the ratio of tidal stress to longitudinal baroclinic pressure gradient. The Wedderburn number (W) relates wind stress to baroclinicity. The stress ratio (S0) sizes tidal stress and wind stress. S0 is a new diagnostic tool for systems influenced by tides and winds, and represents the main contribution of this research. Results show that spring-tide subtidal flows in the tropical lagoon had log(Fr0) ≫ 0 and log(S0) > 0 , i.e., driven mainly by tidal stresses (advective accelerations). Neap tides showed log(Fr0) ≪ 0 and log(S0) < 0) , i.e., flows driven by baroclinicity, especially at the lagoon heads of the east and west sub-basins. However, when the wind stress intensified over the lagoon, the relative importance of baroclinicity decreased and the wind stress controlled the dynamics (log(W) ≫ 0). Each sub-basin exhibited a different subtidal response, according to the dimensionless numbers. The response depended on the fortnightly tidal cycle, the location and magnitude of groundwater input, and the direction and magnitude of the wind stress.

Spatial and temporal variation of water quality in the coastal lagoons of Sinaloa

NASA Astrophysics Data System (ADS)

Paez-Osuna, F.; Lopez-Aguiar, L. K.; Del Río-Chuljak, A.; Ruiz-Fernandez, A. C.

2007-05-01

The Mexican state of Sinaloa has 656 km of coastline and 221,600 ha of coastal lagoons, and is characterized by a high fishing and agriculture activity. It is well known that agricultural activities constitute a major factor affecting the water quality in the coastal waters. The current study focused on the 6 more important coastal lagoons of Sinaloa (Topolobampo-Ohuira-Santa María, Navachiste-San Ignacio-Macapule, Santa María-La Reforma, Altata-Ensenada del Pabellón, Ceuta and Teacapán-Agua Brava) with the aim to evaluate the water quality spatial and temporal variation at the lagoons (physico-chemical parameters, nutrients (N, P and Si), dissolved oxygen, total suspended solids and chlorophyll a) and to assess its eutrophication status. The water samples were collected in several stations at each lagoon (between 9 and 23 stations depending on the lagoon area) at low and high tides, during three different weather periods (dry-warm, rainy and dry-cold seasons) between May 2004 and April 2005. Mean concentrations of nutrients (μM), dissolved oxygen (mg/L) and chlorophyll a (mg/m3) obtained for each variable were comparable between lagoons (total N=51±45; total P= 2.5±1.5; Si=23±31; DO=6.7±1.8; Chll=1.7±1.9) although seasonal and spatial differences were observed at each lagoon. The nutrient concentrations measured fell in the typical concentration intervals for coastal lagoons; however, critical sampling points were identified and related to direct discharges of untreated effluents from municipal wastes, aquaculture farms and agriculture drain ditches.

Distribution and stability of eelgrass beds at Izembek Lagoon, Alaska

USGS Publications Warehouse

Ward, David H.; Markon, Carl J.; Douglas, David C.

1997-01-01

Spatial change in eelgrass meadows, Zostera marina L., was assessed between 1978 and 1987 and between 1987 and 1995 at Izembek Lagoon, Alaska. Change in total extent was evaluated through a map to map comparison of data interpreted from a 1978 Landsat multi-spectral scanner image and 1987 black and white aerial photographs. A ground survey in 1995 was used to assess spatial change from 1987. Eelgrass beds were the predominant vegetation type in the lagoon, comprising 44-47% (15000-16000 ha) of the total area in 1978 and 1987. Izembek Lagoon contains the largest bed of seagrass along the Pacific Coast of North America and largest known single stand of eelgrass in the world. There was a high degree of overlap in the spatial distribution of eelgrass among years of change detection. The overall net change was a 6% gain between, 1978 and 1987 and a <1% gain between 1987 and 1995. The lack of significant change in eelgrass cover suggests that eelgrass meadows in Izembek Lagoon have been stable during the 17-year period of our study.

Digenean species diversity in teleost fishes from the Gulf of Gabes, Tunisia (Western Mediterranean)

PubMed Central

Derbel, H.; Châari, M.; Neifar, L.

2012-01-01

This study is the first attempt to survey the diversity of fish digeneans in the Gulf of Gabes (southern coast of Tunisia). A total of 779 fishes belonging to 32 species were sampled. 53 species of Digenea belonging to 15 families were recorded. Among these species, 24 are reported for the first time from the coast of Tunisia. We report one new host record, Lecithochirium sp. from Sardinella aurita. The Hemiuridae is the dominant family. A host-parasite list is presented with the information on the prevalence, abundance and mean intensity of each species collected. The diversity of Digenea is compared with other localities in the Mediterranean Sea and the northern east of Tunisia. The Gulf of Gabes shows the lowest diversity linked to the anthropogenic activities and impact of exotic species. The use of Digenea as indicators of the state of the ecosystem is discussed. PMID:22550623

Family planning in Tunisia and Morocco: a summary and evaluation of the recent record.

PubMed

Lapham, R

1971-05-01

Family planning activity during 1969-1970 in Morocco and Tunisia is discussed in terms of 12 criteria (such as leadership, educational services, availability) used to evaluate the programs in the 2 countries. Significant differences between family planning activity in the 2 countries can be seen in the nature of involvement of their governments through the open and public endorsement of family planning by Tunisia's president compared to the reserve of Morocco's king. Although family planning programs in both countries are organized within the Ministries of Health, the Tunisian program is conducted by a separate division, the Department of Family Planning and Maternal and Child Health, while Morocco's program is completely integrated within existing health services, a fusion which seems to create financial problems for the Moroccan family planning efforts. The Tunisian program, when compared to that of Morocco, is also characterized by a greater availability of contraceptives, more postpartum education and information activity, available induced-abortion and sterilization services, more widespread use of mass media and communication techniques and greater success in program evaluation. On a population basis, Tunisia (population of 5.2 million in 1970) has about 3 times the number of acceptors as Morocco (population of 15.4 million). Both programs have record-keeping systems which improved considerably during 1969 and 1970, but neither program has an effective field worker network. While Tunisia's program has demonstrated more success in meeting the criteria than Morocco's program and a slight decline has occurred in the crude birth rate in Tunisia in recent years, much of this decline can be attributed to a rising age at marriage resulting from the government's policies of social development. Evaluation indicated that both countries will have to increase availability of contraceptives and encourage effective use if substantial decreases in the crude birth rate are

Evolutionary dynamics of HBV-D7 subgenotype in Tunisia.

PubMed

Ciccozzi, Massimo; Chaouch, Houda; Lo Presti, Alessandra; Taffon, Stefania; Villano, Umbertina; Equestre, Michele; Bruni, Roberto; Marcantonio, Cinzia; Tritarelli, Elena; Cella, Eleonora; Blasi, Aletheia; Aouni, Mahjoub; Letaief, Amel; Ciccaglione, Anna Rita

2017-03-01

Hepatitis B virus (HBV) is the main cause of diseases liver related infecting more than 200 milion persons worldwide. HBV infection shows high level of prevalence in South-East Europe and in Mediterranean basin. In Tunisia, a country with an intermediate level endemicity, HbsAg prevalence ranges from 2 to 5%. Most of the HBV isolates from Tunisia were classified as subgenotype D7 whose circulation is restricted to a specific area of North Africa including Maghreb region. In this paper, the phylogeny of HBV-D7 isolated from 38 Tunisian patients was investigated by analyzing the S gene region of HBV. A Bayesian coalescent-based framework was used to estimate the origin of the HBV-D7 in the country. The Tunisian D7 isolates were found to share a common ancestor whose origin was traced back to 1958. Population dynamics indicated that HBV-D7 epidemic in Tunisia grew exponentially from 1960s to 1990s. After that, the curve reached a plateau around the years 2000 likely due to the implementation of the infant vaccination program in 1996. Epidemiological data suggested that the exponential growth phase was likely sustained by intra-familial transmission events occurring during infancy. Further characterization of HBV-D7 isolates should be performed to evaluate, in the post-vaccination era, the emergence of new transmission routes, and to monitor the efficacy of the vaccination program. J. Med. Virol. 89:469-475, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

The high resolution mapping of the Venice Lagoon tidal network

NASA Astrophysics Data System (ADS)

Madricardo, Fantina; Foglini, Federica; Kruss, Aleksandra; Bellafiore, Debora; Trincardi, Fabio

2017-04-01

One of the biggest challenges of the direct observation of the ocean is to achieve a high resolution mapping of its seafloor morphology and benthic habitats. So far, sonars have mapped just 0.05% of the ocean floor with less than ten-meter resolution. The recent efforts of the scientific community have been devoted towards the mapping of both Deep Ocean and very shallow coastal areas. Coastal and transitional environments in particular undergo strong morphological changes due to natural and anthropogenic pressure. Nowadays, only about 5% of the seafloor of these environments † have been mapped: the shallowness of these environments has prevented the use of underwater acoustics to reveal their morphological features. The recent technological development of multibeam echosounder systems, however, enables these instruments to achieve very high performances also in such shallow environments. In this work, we present results and case studies of an extensive multibeam survey carried out in the Lagoon of Venice in 2013. The Lagoon of Venice is the biggest lagoon in the Mediterranean Sea with a surface of about 550 km2 and with an average depth of about 1 m. In the last century, the morphological and ecological properties of the lagoon changed dramatically: the surface of the salt marshes was reduced by 60% and some parts of the lagoon are deepening with a net sediment flux exiting from the inlets. Moreover, major engineering interventions are currently ongoing at the inlets (MOSE project). These changes at the inlets could affect substantially the lagoon environment. To understand and monitor the future evolution of the Lagoon of Venice, ISMAR within the project RITMARE (a National Research Programme funded by the Italian Ministry of University and Research) carried out an extensive survey, involving a team of more than 25 scientists, to collect high resolution (0.5 m) bathymetry of key study areas such as the tidal inlets and channels. Following a broad

Aspects of fish conservation in the upper Patos Lagoon basin.

PubMed

Fontoura, N F; Vieira, J P; Becker, F G; Rodrigues, L R; Malabarba, L R; Schulz, U H; Möller, O O; Garcia, A M; Vilella, F S

2016-07-01

The Patos Lagoon basin is a large (201 626 km(2) ) and complex drainage system in southern Brazil. The lagoon is 250 km long and 60 km wide, covering an area of 10 360 km(2) . The exchange of water with the Atlantic Ocean occurs through a 0·8 km wide and 15 m deep inlet, fixed by 4 km long jetties, at the southernmost part of the Patos Lagoon. The estuarine area is restricted to its southern portion (10%), although the upper limit of saline waters migrates seasonally and year to year, influenced by the wind regime and river discharge. The known number of recorded limnetic fish species is 200, but this number is expected to increase. A higher endemism is observed in fish species occurring in upper tributaries. The basin suffers from the direct impact of almost 7 million inhabitants, concentrated in small to large cities, most with untreated domestic effluents. There are at least 16 non-native species recorded in natural habitats of the Patos Lagoon basin, about half of these being from other South American river basins. Concerning the fishery, although sport and commercial fisheries are widespread throughout the Patos Lagoon basin, the lagoon itself and the estuarine area are the main fishing areas. Landing statistics are not available on a regular basis or for the whole basin. The fishery in the northern Patos Lagoon captures 31 different species, nine of which are responsible for most of the commercial catches, but only three species are actually sustaining the artisanal fishery: the viola Loricariichthys anus: 455 kg per 10 000 m(2) gillnet per day, the mullet Mugil liza: 123 kg per 10 000 m(2) gillnet per day and the marine catfish Genidens barbus: 50 kg per 10 000 m(2) gillnet per day. A decline of the fish stocks can be attributed to inadequate fishery surveillance, which leads to overfishing and mortality of juveniles, or to decreasing water quality because of urban and industrial activities and power production. Global climatic changes also represent a

Coastal tourism and climate change in Tunisia

NASA Astrophysics Data System (ADS)

Henia, Latifa; Hlaoui, Zouhaier; Alouane, Tahar

2014-05-01

Tunisia is a major tourist destination on the southern shore of the Mediterranean. The tourism sector occupies an important place in the Tunisian economy with 816 hotels, 229,873 beds and a more than six million tourists at the end of the first decade of the 21th century, i.e. , more than half of the population. It offers a large number of direct and indirect jobs: One out of five people work in the tourism sector. The 1960s tourism boom was caused by a number of factors including long days of sunshine, 1,300 km of sandy coast, and a location close to Europe. Tunisian tourism is fundamentally based on two natural determinants: the sun and the sea. The coastline accounts for 95% of tourism investments and functional beds. The high season extends from April to October and it records 73% of nonresident tourists. This results in a homogenous growth of the "product" and its "consumers". This standardization is an important factor in the vulnerability of the Tunisian tourism to climate change. Global warming may affect the comfort level of the swimming season as well as its structure. An estimation of air and water temperature evolution near the Tunisian coasts was conducted under the CLIM-RUN project "Climate Local Information in the Mediterranean Region: Responding to User Needs" funded by the European Union's Seventh Framework Program (FP7). The University of Tunis research unit "GREVACHOT", project partner in charge of the case study of Tunisian tourism, has made the study of comfort indices of the present climate. This paper presents: - The climate comfort indices for seaside tourism in Tunisia, - The approach and results of the future evolution of air and water temperatures by the Tunisian coasts, - The future evolution of climate seaside comfort indices of Tunisia as well as the evolution of the swimming season in relation to global warming.

Marshall Islands Fringing Reef and Atoll Lagoon Observations of the Tohoku Tsunami

NASA Astrophysics Data System (ADS)

Ford, Murray; Becker, Janet M.; Merrifield, Mark A.; Song, Y. Tony

2014-12-01

The magnitude 9.0 Tohoku earthquake on 11 March 2011 generated a tsunami which caused significant impacts throughout the Pacific Ocean. A description of the tsunami within the lagoons and on the surrounding fringing reefs of two mid-ocean atoll islands is presented using bottom pressure observations from the Majuro and Kwajalein atolls in the Marshall Islands, supplemented by tide gauge data in the lagoons and by numerical model simulations in the deep ocean. Although the initial wave arrival was not captured by the pressure sensors, subsequent oscillations on the reef face resemble the deep ocean tsunami signal simulated by two numerical models, suggesting that the tsunami amplitudes over the atoll outer reefs are similar to that in deep water. In contrast, tsunami oscillations in the lagoon are more energetic and long lasting than observed on the reefs or modelled in the deep ocean. The tsunami energy in the Majuro lagoon exhibits persistent peaks in the 30 and 60 min period bands that suggest the excitation of closed and open basin normal modes, while energy in the Kwajalein lagoon spans a broader range of frequencies with weaker, multiple peaks than observed at Majuro, which may be associated with the tsunami behavior within the more irregular geometry of the Kwajalein lagoon. The propagation of the tsunami across the reef flats is shown to be tidally dependent, with amplitudes increasing/decreasing shoreward at high/low tide. The impact of the tsunami on the Marshall Islands was reduced due to the coincidence of peak wave amplitudes with low tide; however, the observed wave amplitudes, particularly in the atoll lagoon, would have led to inundation at different tidal phases.

Literacy in Tunisia: Educational Radio and Television for Adults

ERIC Educational Resources Information Center

Tahar, El Arbi

1971-01-01

The national campaign for literacy in Tunisia provides television broadcasts completed by radio programs. Adults listening to the broadcasts belong to organized centers, with qualified instructors, to semi-organized centers in the hands of national organizations, or to family centers providing instructional materials. (EB)

Mapping Croplands in Morocco and Tunisia using MAGE

NASA Astrophysics Data System (ADS)

McGaughey, K.; Purcell, B.; Tetrault, R. L.; Wasko, C.

2017-12-01

Morocco and Tunisia are both net-wheat importing countries, which experience fluctuations in production due to drought. Knowledge of food supply is critical for the local governments' understanding of food security and to re-assure the population regarding food availability. Tunisia was the epicenter for the event known as the "Arab Spring." Although the Arab Spring had several societal components, chronic uncertainty in the governments' reliability raised concerns about food supply and food availability despite the government's policy responses. Due to its importance for geopolitical as well as market opportunity reasons, in March and April of 2017, analysts from the USDA Foreign Agricultural Service (FAS) traveled to Morocco and Tunisia to conduct crop assessment. Fieldwork data collection is necessary for us as crop analysts to use our convergence of evidence approach, which includes ground information, satellite imagery, meteorological information and reports from our offices abroad. During this trip, analysts used the new mobile application from the National Geospatial Intelligence Agency (NGA) called MAGE to collect fieldwork data for crop classification. Using the several thousand training data collected through the mobile application and by leveraging satellite data within Google Earth Engine, an in-season crop mask was created. The final product was delivered to the team just a few days after returning to USDA Washington and was used in the first wheat production estimate of the season released May 10, 2017. The final product helps analysts determine an experimental in-season area estimation and to focus our other remote sensing tools and products on our areas of interest. The US Department of Agriculture's International Production Assessment Division is responsible for publishing monthly production, area and yield estimates for 17 commodities in over 150 countries.

Atmospheric dust deposition on soils around an abandoned fluorite mine (Hammam Zriba, NE Tunisia).

PubMed

Djebbi, Chaima; Chaabani, Fredj; Font, Oriol; Queralt, Ignasi; Querol, Xavier

2017-10-01

The present study focuses on the eolian dispersion and dust deposition, of major and trace elements in soils in a semi-arid climate, around an old fluorite (CaF 2 ) and barite (BaSO 4 ) mine, located in Hammam Zriba in Northern Tunisia. Ore deposits from this site contain a high amount of metal sulphides constituting heavy metal pollution in the surrounding environment. Samples of waste from the surface of mine tailings and agricultural topsoil samples in the vicinity of the mine were collected. The soil samples and a control sample from unpolluted area, were taken in the direction of prevailing northwest and west winds. Chemical analysis of these solids was performed using both X-ray fluorescence and X-ray diffraction. To determine the transfer from mine wastes to the soils, soluble fraction was performed by inductively coupled plasma and ionic chromatography. The fine grained size fraction of the un-restored tailings, still contained significant levels of barium, strontium, sulphur, fluorine, zinc and lead with mean percentages (wt%) of 30 (calculated as BaO), 13 (as SrO), 10 (as SO 3 ), 4 (F), 2 (Zn) and 1.2 (Pb). Also, high concentrations of cadmium (Cd), arsenic (As) and mercury (Hg) were found with an averages of 36, 24 and 1.2mgkg -1 , respectively. As a result of the eolian erosion of the tailings and their subsequent wind transport, the concentrations of Ba, Sr, S, F, Zn and Pb were extremely high in the soils near to the tailings dumps, with 5%, 4%, 7%, 1%, 0.8% and 0.2%, respectively. Concentration of major pollutants decreases with distance, but they were high even in the farthest samples. Same spatial distribution was observed for Cd, As and Hg. While, the other elements follow different spatial patterns. The leaching test revealed that most elements in the mining wastes, except for the anions, had a low solubility despite their high bulk concentrations. According the 2003/33/CE Decision Threshold, some of these tailings samples were considered as

LANDSAT M. S. S. IMAGE MOSAIC OF TUNISIA.

USGS Publications Warehouse

Boswell-Thomas, J. C.; ,

1984-01-01

The Landsat mosaic of Tunisia funded by USAID for the Remote Sensing Laboratory, Soils Division, Ministry of Agriculture, Tunisia, was completed by the USGS in September 1983. It is a mixed mosaic associating digital corrections and enhancements to manual mosaicking and corresponding to the Tunisian request for high resolution and the limited available funds. The scenes were processed by the Environmental Research Institute of Michigan, resampling the data geodesically corrected to fit the Universal Transverse Mercator projection using control points from topographic maps at 1:50,000 and 1:100,000 scales available in the U. S. The mosaicking was done in the Eastern Mapping Center under the supervision of the Graphic Arts System Section. The three black and white mosaics were made at the 1:1,000,000 scale and various products generated. They included color film positives at 1:2,000,000 and 1:4,000,000 scales reproducible in the Remote Sensing Laboratory in Tunis and corresponding color prints as well as tricolor prints at various scales from 1:500,000 to 1:2,000,000.

Sheep pox in Tunisia: Current status and perspectives.

PubMed

Ben Chehida, F; Ayari-Fakhfakh, E; Caufour, P; Amdouni, J; Nasr, J; Messaoudi, L; Haj Ammar, H; Sghaier, S; Bernard, C; Ghram, A; Cêtre-Sossah, C

2018-02-01

Sheep pox, a well-known endemic capripox infection, has significant impacts on small ruminant populations in Tunisia. It is responsible for high economic losses throughout North Africa due to its enzootic nature and to the active animal transhumance existing in some governorates in Tunisia. The aim of this review was to analyse data gathered on annual vaccination campaigns designed to control its spread by reducing the level of endemicity and to describe diagnostic and management tools adapted to the Tunisian situation. Seasonal, temporal and spatial distributions of sheep pox outbreaks, as well as related clinical features, were found. It was concluded from this review that establishing strong herd immunization through individual animal immunization, creating adequate infrastructure, increasing awareness among breeders, setting up a field-based surveillance network and improving routine diagnostic methods need to be the major components of a programme to eradicate the disease. It was also felt that cost-benefit analyses of the surveillance and control strategies used would help in controlling its persistence. © 2017 Blackwell Verlag GmbH.

Suicide by self-immolation in Tunisia: A 10 year study (2005-2014).

PubMed

Ben Khelil, Mehdi; Zgarni, Amine; Zaafrane, Malek; Chkribane, Youssef; Gharbaoui, Meriem; Harzallah, Hana; Banasr, Ahmed; Hamdoun, Moncef

2016-11-01

In Tunisia, few data are available about self-immolation epidemiology especially in the absence of official statistics on suicides. The aim of our study was to analyze the trends of suicide by self-immolation over a period of ten years (2005-2014). We conducted a descriptive, retrospective study including all the cases of self-immolation suicides that occurred over a period of 10 years (2005-2014) and autopsied in the Department of Legal Medicine of the Charles Nicolle Hospital of Tunis, including self-immolation occurring in Northern Tunisia as well as those committed in remaining governorates and transferred before death to the central intensive care unit of burnt in Tunis receiving patients from all over Tunisia (about 80% of cases occurring in Tunisia). 235 cases of self-immolation were collected. The average age at death was 34.1±12.43 years (range 14-83 years). Gender ratio was of 3.27. Psychiatric history was mentioned in 32.8% of cases, represented by schizophrenia in 17.9% and depression in 12.3% of cases. 12.3% had a history of suicide attempts, and 7.3% presented a history of suicidal threats. The number of casualties of suicide by self-immolation tripled after 2011 with a rising trend during the next three years and slight drop in 2014. The most reported reason in our study was decompensation of a psychiatric illness (24.7%). Self-immolation occurred most frequently in a private home (34.5%) or a public place (30.2). Our study showed that self-immolation affects essentially, young men, who are unemployed and mostly having mental diseases. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

Trace metals in sediments of two estuarine lagoons from Puerto Rico.

PubMed

Acevedo-Figueroa, D; Jiménez, B D; Rodríguez-Sierra, C J

2006-05-01

Concentrations of As, Cd, Cu, Fe, Hg, Pb and Zn were evaluated in surface sediments of two estuaries from Puerto Rico, known as San José Lagoon (SJL) and Joyuda Lagoon. Significantly higher concentrations in microg/g dw of Cd (1.8 vs. 0.1), Cu (105 vs. 22), Hg (1.9 vs. 0.17), Pb (219 vs. 8), and Zn (531 vs. 52) were found in sediment samples from SJL when compared to Joyuda Lagoon. Average concentrations of Hg, Pb, and Zn in some sediment samples from SJL were above the effect range median (ERM) that predict toxic effects to aquatic organisms. Enrichments factors using Fe as a normalizer, and correlation matrices showed that metal pollution in SJL was the product of anthropogenic sources, while the metal content in Joyuda Lagoon was of natural origins. Sediment metal concentrations found in SJL were comparable to aquatic systems classified as contaminated from other regions of the world.

Larval Habitats Characterization and Species Composition of Anopheles Mosquitoes in Tunisia, with Particular Attention to Anopheles maculipennis Complex

PubMed Central

Tabbabi, Ahmed; Boussès, Philippe; Rhim, Adel; Brengues, Cécile; Daaboub, Jabeur; Ben-Alaya-Bouafif, Nissaf; Fontenille, Didier; Bouratbine, Aïda; Simard, Frédéric; Aoun, Karim

2015-01-01

In Tunisia, malaria transmission has been interrupted since 1980. However, the growing number of imported cases and the persistence of putative vectors stress the need for additional studies to assess the risk of malaria resurgence in the country. In this context, our aim was to update entomological data concerning Anopheles mosquitoes in Tunisia. From May to October of 2012, mosquito larval specimens were captured in 60 breeding sites throughout the country and identified at the species level using morphological keys. Environmental parameters of the larval habitats were recorded. Specimens belonging to the An. maculipennis complex were further identified to sibling species by the ribosomal deoxyribonucleic acid (rDNA)–internal transcribed spacer 2 (ITS2) polymerase chain reaction (PCR) technique. In total, 647 Anopheles larvae were collected from 25 habitats. Four species, including An. labranchiae, An. multicolor, An. sergentii, and An. algeriensis, were morphologically identified. rDNA-ITS2 PCR confirmed that An. labranchiae is the sole member of the An. maculipennis complex in Tunisia. An. labranchiae was collected throughout northern and central Tunisia, and it was highly associated with rural habitat, clear water, and sunlight areas. Larvae of An. multicolor and An. sergentii existed separately or together and were collected in southern Tunisia in similar types of breeding places. PMID:25561567

[Preliminary investigation of four anopheles larvae samples susceptibility to chlorpyrifos in Tunisia].

PubMed

Krida, G; Bouattour, A; Rhaim, A; el Kebir, A; Jlidi, R

1998-01-01

Larvae susceptibility to chlorpyrifos is studied on four Tunisian Anopheles larvas samples: Anopheles labranchiae from Rades (South of Tunis) and Menchar (region of Beja), in the North of Tunisia, A. sergentii from Meknassy and A. multicolor from Sidi Bouzid, both in the Centre of Tunisia. The test results of larvae susceplibility indicate that the LC50 and the LC95 values are less than 0.002 and 0.02 mg l-1 respectively and their 95% confidence limits overlap. We also notice that the studied samples show the same susceptibility to chlorpyrifos. The results can be used as a base data further studies on the susceptibility of Anopheles to chemical insecticides.

Selected Bibliography of Educational Materials: Algeria, Libya, Morocco, Tunisia.

ERIC Educational Resources Information Center

Azzouz, Azzedine; And Others

A 100-item bibliography with abstracts of books, newspaper articles, and periodical articles in English and French published predominantly in 1970 offers information on various aspects of education in Algeria, Libya, Morocco, and Tunisia. Emphasis is placed on sections dealing with: (1) educational philosophy, administration, statistics, and…

Educational Assessment of Students in Primary School in Tunisia

ERIC Educational Resources Information Center

Khalifa, Wiem Ben; Souilem, Dalila; Neji, Mahmoud

2017-01-01

Regardless of the study level, the assessments applied in the different educational institutions in Tunisia raise many questions. Do these practices indicate the learners' cognitive metamorphoses? Do formative and summative evaluations intend to access knowledge acquisition at the expense of understanding? Is the content of the evaluation…

Introduction of Sex Education: An American School in Tunisia

ERIC Educational Resources Information Center

Mueller, Elisabeth E.

1971-01-01

This paper describes the introduction of a sex education course into a private American school in Tunisia. The steps involved in the development of the project and curriculum are recorded. The impact of the project on receptive Tunisian authorities and its influence on change are discussed. (Author)

Reproductive Health Policy in Tunisia: Women's Right to Reproductive Health and Gender Empowerment.

PubMed

Amroussia, Nada; Goicolea, Isabel; Hernandez, Alison

2016-12-01

Although Tunisia is regarded as a pioneer in the Middle East and North Africa in terms of women's status and rights, including sexual and reproductive health and rights, evidence points to a number of persisting challenges. This article uses the Health Rights of Women Assessment Instrument (HeRWAI) to analyze Tunisia's reproductive health policy between 1994 and 2014. It explores the extent to which reproductive rights have been incorporated into the country's reproductive health policy, the gaps in the implementation of this policy, and the influence of this policy on gender empowerment. Our results reveal that progress has been slow in terms of incorporating reproductive rights into the national reproductive health policy. Furthermore, the implementation of this policy has fallen short, as demonstrated by regional inequities in the accessibility and availability of reproductive health services, the low quality of maternal health care services, and discriminatory practices. Finally, the government's lack of meaningful engagement in advancing gender empowerment stands in the way as the main challenge to gender equality in Tunisia.

Project summary. PERSISTENCE OF PATHOGENS IN LAGOON-STORED SLUDGE (EPA/600/S2-89/015)

EPA Science Inventory

The project objective was to investigate pathogen inactlvation in lagoon-stored municipal sludges. The in-field lagoons were located in Louisiana (New Orleans) and in Texas (Port Aransas), both semitropical areas of the United States. Each lagoon was filled with 7.56 mL of ...

Water resources management strategies and its implications on hydrodynamic and hydrochemical changes of costal groundwater: Case of Grombalia shallow aquifer, NE Tunisia

NASA Astrophysics Data System (ADS)

Lachaal, Fethi; Chekirbane, Anis; Chargui, Sameh; Sellami, Haykel; Tsujimura, Maki; Hezzi, Hmida; Faycel, Jelassi; Mlayah, Ammar

2016-12-01

Information on groundwater quantity as well as quality is required by water managers and decision-makers for defining a sustainable management strategy. This requires a comprehensive assessment of the surface water and groundwater resources. This paper provides an assessment of water resources management strategy in the Grombalia region (Northeast Tunisia) and its impact on quantity and quality evolution of groundwater resources based on an approach that combines (i) hydro-climatic data, (ii) field monitoring, (iii) historic piezometric records, and (iv) geochemical and stable isotopes (δ18O and δ2H) analyses. We apply this approach to identify the origin of the various water resources and outline how the actual water management impact the quantity and quality of the groundwater in the region. As consequence of poor water resources management, the shallow groundwater levels have been disrupted: a groundwater rise is observed in the centre and a piezometric drawdown is observed in the upstream regions. Groundwater quality degradation was registered especially in the centre and downstream zones.

Bacterioplankton diversity and community composition in the Southern Lagoon of Venice.

PubMed

Simonato, Francesca; Gómez-Pereira, Paola R; Fuchs, Bernhard M; Amann, Rudolf

2010-04-01

The Lagoon of Venice is a large water basin that exchanges water with the Northern Adriatic Sea through three large inlets. In this study, the 16S rRNA approach was used to investigate the bacterial diversity and community composition within the southern basin of the Lagoon of Venice and at one inlet in October 2007 and June 2008. Comparative sequence analysis of 645 mostly partial 16S rRNA gene sequences indicated high diversity and dominance of Alphaproteobacteria, Gammaproteobacteria and Bacteroidetes at the lagoon as well as at the inlet station, therefore pointing to significant mixing. Many of these sequences were close to the 16S rRNA of marine, often coastal, bacterioplankton, such as the Roseobacter clade, the family Vibrionaceae, and class Flavobacteria. Sequences of Actinobacteria were indicators of a freshwater input. The composition of the bacterioplankton was quantified by catalyzed reporter deposition fluorescence in situ hybridization (CARD-FISH) with a set of rRNA-targeted oligonucleotide probes. CARD-FISH counts corroborated the dominance of members of the phyla Alphaproteobacteria, Gammaproteobacteria and Bacteroidetes. When assessed by a probe set for the quantification of selected clades within Alphaproteobacteria and Gammaproteobacteria, bacterioplankton composition differed between October 2007 and June 2008, and also between the inlet and the lagoon. In particular, members of the readily culturable copiotrophic gammaproteobacterial genera Vibrio, Alteromonas and Pseudoalteromonas were enriched in the southern basin of the Lagoon of Venice. Interestingly, the alphaproteobacterial SAR11 clade and related clusters were also present in high abundances at the inlet and within the lagoon, which was indicative of inflow of water from the open sea.

Ambivalence, Modernisation and Language Attitudes: French and Arabic in Tunisia.

ERIC Educational Resources Information Center

Stevens, Paul B.

1983-01-01

Examines the ambivalent attitude toward the major speech varieties used in Tunisia (French, Classical Arabic, and Tunisian Arabic) and seeks to show the effects of that ambivalence on language policy, especially with regard to Arabization and bilingualism. (EKN)

Chasing boundaries and cascade effects in a coupled barrier - marshes - lagoon system

NASA Astrophysics Data System (ADS)

Lorenzo Trueba, J.; Mariotti, G.

2015-12-01

Low-lying coasts are often characterized by barriers islands, shore-parallel stretches of sand separated from the mainland by marshes and lagoons. We built an exploratory numerical model to examine the morphological feedbacks within an idealized barrier - marshes -lagoon system and predict its evolution under projected rates of sea level rise and sediment supply to the backbarrier environment. Our starting point is a recently developed morphodynamic model, which couples shoreface evolution and overwash processes in a dynamic framework. As such, the model is able to capture dynamics not reproduced by morphokinematic models, which advect geometries without specific concern to processes. These dynamics include periodic barrier retreat due to time lags in the shoreface response to barrier overwash, height drowning due to insufficient overwash fluxes as sea level rises, and width drowning, which occurs when the shoreface response rate is insufficient to maintain the barrier geometry during overwash-driven landward migration. We extended the model by coupling the barrier model with a model for the evolution of the marsh platform and the boundary between the marsh and the adjacent lagoon. The coupled model explicitly describes marsh edge processes and accounts for the modification of the wave regime associated with lagoon width (fetch). Model results demonstrate that changes in factors that are not typically associated with the dynamics of coastal barriers, such as the lagoon width and the rate of export/import of sediments from and to the lagoon, can lead to previously unidentified complex responses of the coupled system. In particular, a wider lagoon in the backbarrier, and/or a reduction in the supply of muddy sediments to the backbarrier, can increase barrier retreat rates and even trigger barrier drowning. Overall, our findings highlight the importance of incorporating backbarrier dynamics in models that aim at predicting the response of barrier systems.

Assessment of global solar radiation to examine the best locations to install a PV system in Tunisia

NASA Astrophysics Data System (ADS)

Belkilani, Kaouther; Ben Othman, Afef; Besbes, Mongi

2018-02-01

The study of the solar radiation is the starting point of any investigation for a new energy, to study and search the best location to install a PV system. A very important factor in the assessment of solar potential is the availability of data for global solar radiation that must be coherent and of high quality. In this paper, we analyze the estimation result of the monthly global solar radiation for three different locations, Bizerte in Northern Tunisia, Kairouan in Middle Eastern Tunisia, and Tozeur in Southern Tunisia, measured on the surface by the National Institute of Meteorology and the meteorological year irradiation based on satellite imagery result PVGIS radiation databases. To get the right measurements with minimum error, we propose a numerical model used to calculate the global solar radiation in the indicated three sites. The results show that the model can estimate the global solar radiation (kWh/m²) at a specific station and over most area of Tunisia. The model gives a good estimation for solar radiation where error between the measured values and those calculated are negligible.

Impact of mussel bioengineering on fine-grained sediment dynamics in a coastal lagoon: A numerical modelling investigation

NASA Astrophysics Data System (ADS)

Forsberg, Pernille L.; Lumborg, Ulrik; Bundgaard, Klavs; Ernstsen, Verner B.

2017-12-01

Rødsand lagoon in southeast Denmark is a non-tidal coastal lagoon. It is home to a wide range of marine flora and fauna and part of the Natura 2000 network. An increase in turbidity through elevated levels of suspended sediment concentration (SSC) within the lagoon may affect the ecosystem health due to reduced light penetration. Increasing SSC levels within Rødsand lagoon could be caused by increasing storm intensity or by a sediment spill from dredging activities west of the lagoon in relation to the planned construction of the Fehmarnbelt fixed link between Denmark and Germany. The aim of the study was to investigate the impact of a mussel reef on sediment import and SSC in a semi-enclosed lagoon through the development of a bioengineering modelling application that makes it possible to include the filtrating effect of mussels in a numerical model of the lagoonal system. The numerical implementation of an exterior mussel reef generated a reduction in the SSC in the vicinity of the reef, through the adjacent inlet and in the western part of the lagoon. The mussel reef reduced the sediment import to Rødsand lagoon by 13-22% and reduced the SSC within Rødsand lagoon by 5-9% depending on the filtration rate and the reef length. The results suggest that the implementation of a mussel reef has the potential to relieve the pressure of increasing turbidity levels within a semi-enclosed lagoonal system. However, further assessment and development of the bioengineering application and resulting ecosystem impacts are necessary prior to actual implementation.

Analysis of the unique geothermal microbial ecosystem of the Blue Lagoon.

PubMed

Petursdottir, Solveig K; Bjornsdottir, Snaedis H; Hreggvidsson, Gudmundur O; Hjorleifsdottir, Sigridur; Kristjansson, Jakob K

2009-12-01

Cultivation and culture-independent techniques were used to describe the geothermal ecosystem of the Blue Lagoon in Iceland. The lagoon contains both seawater and freshwater of geothermal origin and is extremely high in silica content. Water samples were collected repeatedly in summer and autumn in 2003 and 2005 and in winter 2006 were analyzed for species composition. The study revealed the typical traits of an extreme ecosystem characterized by dominating species and other species represented in low numbers. A total of 35 taxa were identified. The calculated biodiversity index of the samples was 2.1-2.5. The majority (83%) of analyzed taxa were closely related to bacteria of marine and geothermal origin reflecting a marine character of the ecosystem and the origin of the Blue Lagoon hydrothermal fluid. A high ratio (63%) of analyzed taxa represented putative novel bacterial species. The majority (71%) of analyzed clones were Alphaproteobacteria, of which 80% belonged to the Roseobacter lineage within the family of Rhodobacteraceae. Of seven cultivated species, the two most abundant ones belonged to this lineage. Silicibacter lacuscaerulensis was confirmed as a dominating species in the Blue Lagoon. One group of isolates represented a recently identified species within the genus of Nitratireductor within Rhizobiales. This study implies an annually stable and seasonally dynamic ecosystem in the Blue Lagoon.

Water sources, mixing and evaporation in the Akyatan lagoon, Turkey

NASA Astrophysics Data System (ADS)

Lécuyer, C.; Bodergat, A.-M.; Martineau, F.; Fourel, F.; Gürbüz, K.; Nazik, A.

2012-12-01

Akyatan lagoon, located southeast of Turkey along the Mediterranean coast, is a choked and hypersaline lagoon, and hosts a large and specific biodiversity including endangered sea turtles and migrating birds. Physicochemical properties of this lagoon were investigated by measuring temperature, salinity, and hydrogen and oxygen isotope ratios of its waters at a seasonal scale during years 2006 and 2007. Winter and spring seasons were dominated by mixing processes between freshwaters and Mediterranean seawater. The majority of spring season waters are formed by evapoconcentration of brackish water at moderate temperatures of 22 ± 2 °C. During summer, hypersaline waters result from evaporation of seawater and brackish waters formed during spring. Evaporation over the Akyatan lagoon reaches up to 76 wt% based on salinity measurements and operated with a dry (relative humidity of 0.15-0.20) and hot (44 ± 6 °C) air. These residual waters were characterized by the maximal seasonal isotopic enrichment in both deuterium and 18O relative to VSMOW. During autumn, most lagoonal waters became hypersaline and were formed by evaporation of waters that had isotopic compositions and salinities close to that of seawater. These autumnal hypersaline waters result from an air humidity close to 0.45 and an atmospheric temperature of evaporation of 35 ± 5 °C, which are responsible for up to 71 wt% of evaporation, with restricted isotopic enrichments relative to VSMOW. During the warm seasons, the combination of air humidity, wind velocity and temperature were responsible for a large kinetic component in the total isotopic fractionation between water liquid and water vapour.

Changes in sludge accumulation of anaerobic swine lagoons receiving pretreated influent

USDA-ARS?s Scientific Manuscript database

This study evaluated the changes in sludge depth and volume of anaerobic swine lagoon in North Carolina after six years of applying treatment to the liquid flushed manure prior to entering the lagoon. The farm had seven swine barns with a permitted capacity of 5,145 head feeder to finish (735 head/b...

Whiteriver Sewage Lagoons, Whiteriver, AZ: AZ0024058

EPA Pesticide Factsheets

Authorization to Discharge Under National Pollutant Discharge Elimination System (NPDES) Permit No. AZ0024058 for Tribal Utility Authority, White Mountain Apache Tribe Whiteriver Sewage Lagoons, Whiteriver, AZ.

Library Education in Tunisia and Jordan: A Comparative Study.

ERIC Educational Resources Information Center

Bouazza, A.; Nimer, R.

1986-01-01

This article examines the state of development of library education in Jordan and Tunisia and pinpoints problems affecting this development in order to verify if library education in countries with similar cultures and type of economy evolves similarly and faces same problems. A brief introduction to the countries is provided. (EJS)

Larval habitats characterization and species composition of Anopheles mosquitoes in Tunisia, with particular attention to Anopheles maculipennis complex.

PubMed

Tabbabi, Ahmed; Boussès, Philippe; Rhim, Adel; Brengues, Cécile; Daaboub, Jabeur; Ben-Alaya-Bouafif, Nissaf; Fontenille, Didier; Bouratbine, Aïda; Simard, Frédéric; Aoun, Karim

2015-03-01

In Tunisia, malaria transmission has been interrupted since 1980. However, the growing number of imported cases and the persistence of putative vectors stress the need for additional studies to assess the risk of malaria resurgence in the country. In this context, our aim was to update entomological data concerning Anopheles mosquitoes in Tunisia. From May to October of 2012, mosquito larval specimens were captured in 60 breeding sites throughout the country and identified at the species level using morphological keys. Environmental parameters of the larval habitats were recorded. Specimens belonging to the An. maculipennis complex were further identified to sibling species by the ribosomal deoxyribonucleic acid (rDNA)-internal transcribed spacer 2 (ITS2) polymerase chain reaction (PCR) technique. In total, 647 Anopheles larvae were collected from 25 habitats. Four species, including An. labranchiae, An. multicolor, An. sergentii, and An. algeriensis, were morphologically identified. rDNA-ITS2 PCR confirmed that An. labranchiae is the sole member of the An. maculipennis complex in Tunisia. An. labranchiae was collected throughout northern and central Tunisia, and it was highly associated with rural habitat, clear water, and sunlight areas. Larvae of An. multicolor and An. sergentii existed separately or together and were collected in southern Tunisia in similar types of breeding places. © The American Society of Tropical Medicine and Hygiene.

Are Sea Surface Temperature satellite measurements reliable proxies of lagoon temperature in the South Pacific?

NASA Astrophysics Data System (ADS)

Van Wynsberge, Simon; Menkes, Christophe; Le Gendre, Romain; Passfield, Teuru; Andréfouët, Serge

2017-12-01

In remote coral reef environments, lagoon and reef in situ measurements of temperature are scarce. Sea Surface Temperature (SST) measured by satellite has been frequently used as a proxy of the lagoon temperature experienced by coral reef organisms (TL) especially during coral bleaching events. However, the link between SST and TL is poorly characterized. First, we compared the correlation between various SST series and TL from 2012 to 2016 in three atolls and one island in the Central South Pacific Ocean. Simple linear correlation between SST and TL ranged between 0.44 and 0.97 depending on lagoons, localities of sensors, and type of SST data. High-resolution-satellite-measurements of SST inside the lagoons did not outperform oceanic SST series, suggesting that SST products are not adapted for small lagoons. Second, we modelled the difference between oceanic SST and TL as a function of the drivers of lagoon water renewal and mixing, namely waves, tide, wind, and season. The multivariate models reduced significantly the bias between oceanic SST and TL. In atoll lagoons, and probably in other hydrodynamically semi-open systems, a correction taking into account these factors is necessary when SST are used to characterize organisms' thermal stress thresholds.

[Species and size composition of fishes in Barra de Navidad lagoon, Mexican central Pacific].

PubMed

González-Sansón, Gaspar; Aguilar-Betancourt, Consuelo; Kosonoy-Aceves, Daniel; Lucano-Ramírez, Gabriela; Ruiz-Ramírez, Salvador; Flores-Ortega, Juan Ramón; Hinojosa-Larios, Angel; de Asís Silva-Bátiz, Francisco

2014-03-01

Coastal lagoons are considered important nursery areas for many coastal fishes. Barra de Navidad coastal lagoon (3.76km2) is important for local economy as it supports tourism development and artisanal fisheries. However, the role of this lagoon in the dynamics of coastal fish populations is scarcely known. Thus, the objectives of this research were: to characterize the water of the lagoon and related weather conditions, to develop a systematic list of the ichthyofauna, and to estimate the proportion of juveniles in the total number of individuals captured of most abundant species. Water and fish samples were collected between March 2011 and February 2012. Physical and chemical variables were measured in rainy and dry seasons. Several fishing gears were used including a cast net, beach purse seine and gillnets of four different mesh sizes. Our results showed that the lagoon is most of the time euhaline (salinity 30-40ups), although it can be mixopolyhaline (salinity 18-30ups) during short periods. Chlorophyll and nutrients concentrations suggested eutrophication in the lagoon. Mean water temperature changed seasonally from 24.9 degrees C (April, high tide) to 31.4 degrees C (October, low tide). Considering ichthyofauna species, a total of 36 448 individuals of 92 species were collected, 31 of them adding up to 95% of the total of individuals caught. Dominant species were Anchoa spp. (44.6%), Diapterus peruvianus (10.5%), Eucinostomus currani (8.1%), Cetengraulis mysticetus (7.8%), Mugil curema (5.2%) and Opisthonema libertate (4.5%). The lagoon is an important juvenile habitat for 22 of the 31 most abundant species. These included several species of commercial importance such as snappers (Lutjanus argentiventris, L. colorado and L. novemfasciatus), snook (Centropomus nigrescens) and white mullet (Mugil curema). Other four species seem to use the lagoon mainly as adults. This paper is the first contribution on the composition of estuarine ichthyofauna in Jalisco

Spatial variability in fish species assemblage and community structure in four subtropical lagoons of the Okavango Delta, Botswana

NASA Astrophysics Data System (ADS)

Mosepele, K.; Mosepele, B.; Bokhutlo, T.; Amutenya, K.

The species assemblage and community structure of four lagoons was assessed through time series data collected between 2001 and 2005 in the Okavango Delta. The main aim of this study was to evaluate the importance of lagoons as fish habitats in the Delta. Therefore, this study assessed the importance of these habitats through determining fish species diversity, composition, relative abundance, and community structure between the lagoons. Forty six species belonging to 11 families and five orders were collected over the study period. Main results showed that Cichlidae was the most important family and had the highest species richness in the lagoons. Significant differences ( p < 0.05) were observed in species richness, faunal composition, and diversity among some of the lagoons. Moreover, there were also variations in species composition, and also significant differences in mean length and weight of some selected fish species in the four lagoons. This study showed that lagoons are important repositories of food fish to local communities. Moreover, a management of the fish stocks based on restricting fishing in some lagoons as protected areas is not feasible because of these significant differences in species assemblages between lagoons. Furthermore, lagoons are subject to multiple where most of the lodges are constructed, which makes subsequently makes them vulnerable to pollution. Therefore, the integrity of lagoon habitats needs to be maintained so that their ecosystem functioning (i.e. fish repositories) is maintained.

Monitoring land degradation in southern Tunisia: A test of LANDSAT imagery and digital data

NASA Technical Reports Server (NTRS)

Hellden, U.; Stern, M.

1980-01-01

The possible use of LANDSAT imagery and digital data for monitoring desertification indicators in Tunisia was studied. Field data were sampled in Tunisia for estimation of mapping accuracy in maps generated through interpretation of LANDSAT false color composites and processing of LANDSAT computer compatible tapes respectively. Temporal change studies were carried out through geometric registration of computer classified windows from 1972 to classified data from 1979. Indications on land degradation were noted in some areas. No important differences, concerning results, between the interpretation approach and the computer processing approach were found.

Monitoring benthic foraminiferal dynamics at Bottsand coastal lagoon (western Baltic Sea)

NASA Astrophysics Data System (ADS)

Schönfeld, Joachim

2018-04-01

Benthic foraminifera from Bottsand coastal lagoon, western Baltic Sea, have been studied since the mid-1960s. They were monitored annually in late autumn since 2003 at the terminal ditch of the lagoon. There were 12 different species recognised, of which three have not been recorded during earlier investigations. Dominant species showed strong interannual fluctuations and a steady increase in population densities over the last decade. Elphidium incertum, a stenohaline species of the Baltic deep water fauna, colonised the Bottsand lagoon in 2016, most likely during a period of salinities >19 units and water temperatures of 18 °C on average in early autumn. The high salinities probably triggered their germination from a propagule bank in the ditch bottom sediment. The new E. incertum population showed densities higher by an order of magnitude than those of the indigenous species. The latter did not decline, revealing that E. incertum used another food source or occupied a different microhabitat. Elphidium incertum survived transient periods of lower salinities in late autumn 2017, though with reduced abundances, and became a regular faunal constituent at the Bottsand lagoon.

Methane fluxes from tropical coastal lagoons surrounded bymangroves, Yucatán, Mexico

USGS Publications Warehouse

Chuang, Pei-Chuan; Young, Megan B.; Dale, Andrew W.; Miller, Laurence G.; Herrera-Silveira, Jorge A; Paytan, Adina

2017-01-01

Methane concentrations in the water column and emissions to the atmosphere were determined for three tropical coastal lagoons surrounded by mangrove forests on the Yucatán Peninsula, Mexico. Surface water dissolved methane was sampled at different seasons over a period of 2 years in areas representing a wide range of salinities and anthropogenic impacts. The highest surface water methane concentrations (up to 8378 nM) were measured in a polluted canal associated with Terminos Lagoon. In Chelem Lagoon, methane concentrations were typically lower, except in the polluted harbor area (1796 nM). In the relatively pristine Celestún Lagoon, surface water methane concentrations ranged from 41 to 2551 nM. Methane concentrations were negatively correlated with salinity in Celestún, while in Chelem and Terminos high methane concentrations were associated with areas of known pollution inputs, irrespective of salinity. The diffusive methane flux from surface lagoon water to the atmosphere ranged from 0.0023 to 15 mmol CH4 m−2 d−1. Flux chamber measurements revealed that direct methane release as ebullition was up to 3 orders of magnitude greater than measured diffusive flux. Coastal mangrove lagoons may therefore be an important natural source of methane to the atmosphere despite their relatively high salinity. Pollution inputs are likely to substantially enhance this flux. Additional statistically rigorous data collected globally are needed to better consider methane fluxes from mangrove-surrounded coastal areas in response to sea level changes and anthropogenic pollution in order to refine projections of future atmospheric methane budgets.

Chasing boundaries and cascade effects in a coupled barrier-marsh-lagoon system

NASA Astrophysics Data System (ADS)

Lorenzo-Trueba, Jorge; Mariotti, Giulio

2017-08-01

The long-term dynamic evolution of an idealized barrier-marsh-lagoon system experiencing sea-level rise is studied by coupling two existing numerical models. The barrier model accounts for the interaction between shoreface dynamics and overwash flux, which allows the occurrence of barrier drowning. The marsh-lagoon model includes both a backbarrier marsh and an interior marsh, and accounts for the modification of the wave regime associated with changes in lagoon width and depth. Overwash, the key process that connects the barrier shoreface with the marsh-lagoon ecosystems, is formulated to account for the role of the backbarrier marsh. Model results show that a number of factors that are not typically associated with the dynamics of coastal barriers can enhance the rate of overwash-driven landward migration by increasing backbarrier accommodation space. For instance, lagoon deepening could be triggered by marsh edge retreat and consequent export of fine sediment via tidal dispersion, as well as by an expansion of inland marshes and consequent increase in accommodation space to be filled in with sediment. A deeper lagoon results in a larger fraction of sediment overwash being subaqueous, which coupled with a slow shoreface response sending sediment onshore can trigger barrier drowning. We therefore conclude that the supply of fine sediments to the back-barrier and the dynamics of both the interior and backbarrier marsh can be essential for maintaining the barrier system under elevated rates of sea-level rise. Our results highlight the importance of considering barriers and their associated backbarriers as part of an integrated system in which sediment is exchanged.

Structural evolution of Cenozoic basins in northeastern Tunisia, in response to sinistral strike-slip movement on the El Alia-Teboursouk Fault

NASA Astrophysics Data System (ADS)

Bejaoui, Hamida; Aïfa, Tahar; Melki, Fetheddine; Zargouni, Fouad

2017-10-01

This paper resolves the structural complexity of Cenozoic sedimentary basins in northeastern Tunisia. These basins trend NE-SW to ∼ E-W, and are bordered by old fracture networks. Detailed descriptions of the structural features in outcrop and in subsurface data suggest that the El Alia-Teboursouk Fault zone in the Bizerte area evolved through a series of tectonic events. Cross sections, lithostratigraphic correlations, and interpretation of seismic profiles through the basins show evidence for: (i) a Triassic until Jurassic-Early Cretaceous rifting phase that induced lateral variations of facies and strata thicknesses; (ii) a set of faults oriented NE-SW, NW-SE, N-S, and E-W that guided sediment accumulation in pull-apart basins, which were subject to compressive and transpressive deformation during Eocene (Lutetian-Priabonian), Miocene (Tortonian), and Pliocene-Quaternary; and (iii) NNW-SSE to NS contractional events that occurred during the Late Pliocene. Part of the latest phase has been the formation of different synsedimentary folded structures with significant subsidence inversion. Such events have been responsible for the reactivation of inherited faults, and the intrusion of Triassic evaporites, ensuring the role of a slip layer. The combined effects of the different paleoconstraints and halokinetic movements are at the origin of the evolution of these pull-apart basins. The subsurface data suggest that an important fault displacement occurred during the Mesozoic-Cenozoic. The patterns of sediment accumulation in the different basins reflect a high activity of deep ancient faults.

Echinococcus granulosus sensu stricto (s.s.) from the critically endangered antelope Addax nasomaculatus in Tunisia.

PubMed

Boufana, Belgees; Saïd, Yousra; Dhibi, Mokhtar; Craig, Philip S; Lahmar, Samia

2015-12-01

Echinococcus granulosus sensu lato (s.l.) is a zoonotic disease highly endemic in Tunisia. Canids including stray and semi-stray dogs, jackals and foxes are known as definitive hosts and a wide range of ungulates have been shown to harbour the metacestode hydatid stage and may serve as intermediate hosts. Fertile hydatid cysts of Echinococcus equinus and E. granulosus sensu stricto (s.s.) were recently molecularly identified for the first time from Tunisian donkeys. E. granulosus (s.s.) was also identified from wild boars in Tunisia. Here we report the confirmation of hydatid cysts caused by E. granulosus (s.s.) in the critically endangered antelope, Addax nasomaculatus in Tunisia. DNA-based molecular analysis revealed that A.nasomaculatus was infected with E. granulosus (s.s.) which had a 100% identity with the main globally distributed E. granulosus (s.s.) (EgTu01) haplotype. Cysts of Taenia hydatigena (n=33) were also observed on the liver and in the body cavity. Due to their endangered status and their relatively small numbers, it is unlikely that hydatid infection of A. nasomaculatus will form a major contribution to the epidemiology and transmission of E. granulosus in Tunisia, but infection may result in pathology, morbidity and early mortality, and may still play a role in the perpetuation of the parasite in wildlife cycles. Copyright © 2015 Elsevier B.V. All rights reserved.

Phylogenetic Analysis and Epidemic History of Hepatitis C Virus Genotype 2 in Tunisia, North Africa

PubMed Central

Rajhi, Mouna; Ghedira, Kais; Chouikha, Anissa; Djebbi, Ahlem; Cheikh, Imed; Ben Yahia, Ahlem; Sadraoui, Amel; Hammami, Walid; Azouz, Msaddek; Ben Mami, Nabil; Triki, Henda

2016-01-01

HCV genotype 2 (HCV-2) has a worldwide distribution with prevalence rates that vary from country to country. High genetic diversity and long-term endemicity were suggested in West African countries. A global dispersal of HCV-2 would have occurred during the 20th century, especially in European countries. In Tunisia, genotype 2 was the second prevalent genotype after genotype 1 and most isolates belong to subtypes 2c and 2k. In this study, phylogenetic analyses based on the NS5B genomic sequences of 113 Tunisian HCV isolates from subtypes 2c and 2k were carried out. A Bayesian coalescent-based framework was used to estimate the origin and the spread of these subtypes circulating in Tunisia. Phylogenetic analyses of HCV-2c sequences suggest the absence of country-specific or time-specific variants. In contrast, the phylogenetic grouping of HCV-2k sequences shows the existence of two major genetic clusters that may represent two distinct circulating variants. Coalescent analysis indicated a most recent common ancestor (tMRCA) of Tunisian HCV-2c around 1886 (1869–1902) before the introduction of HCV-2k in 1901 (1867–1931). Our findings suggest that the introduction of HCV-2c in Tunisia is possibly a result of population movements between Tunisia and European population following the French colonization. PMID:27100294

Phylogenetic Analysis and Epidemic History of Hepatitis C Virus Genotype 2 in Tunisia, North Africa.

PubMed

Rajhi, Mouna; Ghedira, Kais; Chouikha, Anissa; Djebbi, Ahlem; Cheikh, Imed; Ben Yahia, Ahlem; Sadraoui, Amel; Hammami, Walid; Azouz, Msaddek; Ben Mami, Nabil; Triki, Henda

2016-01-01

HCV genotype 2 (HCV-2) has a worldwide distribution with prevalence rates that vary from country to country. High genetic diversity and long-term endemicity were suggested in West African countries. A global dispersal of HCV-2 would have occurred during the 20th century, especially in European countries. In Tunisia, genotype 2 was the second prevalent genotype after genotype 1 and most isolates belong to subtypes 2c and 2k. In this study, phylogenetic analyses based on the NS5B genomic sequences of 113 Tunisian HCV isolates from subtypes 2c and 2k were carried out. A Bayesian coalescent-based framework was used to estimate the origin and the spread of these subtypes circulating in Tunisia. Phylogenetic analyses of HCV-2c sequences suggest the absence of country-specific or time-specific variants. In contrast, the phylogenetic grouping of HCV-2k sequences shows the existence of two major genetic clusters that may represent two distinct circulating variants. Coalescent analysis indicated a most recent common ancestor (tMRCA) of Tunisian HCV-2c around 1886 (1869-1902) before the introduction of HCV-2k in 1901 (1867-1931). Our findings suggest that the introduction of HCV-2c in Tunisia is possibly a result of population movements between Tunisia and European population following the French colonization.

Assessment of the trophic state of a hypersaline-carbonatic environment: Vermelha Lagoon (Brazil)

PubMed Central

Martins, Maria Virginia Alves; Frontalini, Fabrizio; Ballalai, João M.; Belart, Pierre; Habib, Renan; Fontana, Luiz F.; Clemente, Iara M. M. M.; Lorini, Maria Lucia; Mendonça Filho, João G.; Laut, Vanessa M.; Figueiredo, Marcos de Souza Lima

2017-01-01

Vermelha Lagoon is a hypersaline shallow transitional ecosystem in the state of Rio de Janeiro (Brazil). This lagoon is located in the protected area of Massambaba, between the cities of Araruama and Saquarema (Brazil), and displays two quite uncommon particularities: it exhibits carbonate sedimentation and displays the development of Holocene stromatolites. Due to both particularities, the salt industry and property speculation have been, increasingly, generating anthropic pressures on this ecosystem. This study aims to apply a multiproxy approach to evaluate the trophic state of Vermelha Lagoon based on physicochemical parameters and geochemical data for the quantification and qualification of organic matter (OM), namely total organic carbon (TOC), total sulfur (TS), total phosphorus (TP) and biopolymeric carbon (BPC), including carbohydrates (CHO), lipids (LIP) and proteins (PTN). The CHO/TOC ratio values suggest that OM supplied to the sediment is of autochthonous origin and results, essentially, from microbial activity. The cluster analyses allowed the identification of four regions in Vermelha Lagoon. The Region I included stations located in shallow areas of the eastern sector of Vermelha lagoon affected by the impact of the artificial channel of connection with Araruama Lagoon. The Region II, under the influence of salt pans, is characterized by the highest values of BPC, namely CHO promoted by microbiological activity. The Region III include stations spread through the lagoon with high values of dissolved oxygen and lower values of TP. Stromatolites and microbial mattes growth was observed in some stations of this sector. Region IV, where the highest values of TOC and TS were found, represents depocenters of organic matter, located in general in depressed areas. Results of this work evidences that the Vermelha Lagoon is an eutrophic but alkaline and well oxygenated environment (at both water column and surface sediment) where the autotrophic activity is

Induction of Purple Sulfur Bacterial Growth in Dairy Wastewater Lagoons by Circulation

USDA-ARS?s Scientific Manuscript database

Aims: To determine if circulation of diary wastewater induces the growth of phototrophic purple sulfur bacteria (PSB). Methods and Results: Two dairy wastewater lagoons that were similar in size, geographic location, number and type of cattle loading the lagoons were chosen. The only obvious diffe...

Assessing hog lagoon waste contamination in the Cape Fear Watershed using Bacteroidetes 16S rRNA gene pyrosequencing.

PubMed

Arfken, Ann M; Song, Bongkeun; Mallin, Michael A

2015-09-01

Hog lagoons can be major sources of waste and nutrient contamination to watersheds adjacent to pig farms. Fecal source tracking methods targeting Bacteroidetes 16S rRNA genes in pig fecal matter may underestimate or fail to detect hog lagoon contamination in riverine environments. In order to detect hog lagoon wastewater contamination in the Cape Fear Watershed, where a large number of hog farms are present, we conducted pyrosequencing analyses of Bacteroidetes 16S rRNA genes in hog lagoon waste and identified new hog lagoon-specific marker sequences. Additional pyrosequencing analyses of Bacteroidetes 16S rRNA genes were conducted with surface water samples collected at 4 sites during 5 months in the Cape Fear Watershed. Using an operational taxonomic unit (OTU) identity cutoff value of 97 %, these newly identified hog lagoon markers were found in 3 of the river samples, while only 1 sample contained the pig fecal marker. In the sample containing the pig fecal marker, there was a relatively high percentage (14.1 %) of the hog lagoon markers and a low pig fecal marker relative abundance of 0.4 % in the Bacteroidetes 16S rRNA gene sequences. This suggests that hog lagoon contamination must be somewhat significant in order for pig fecal markers to be detected, and low levels of hog lagoon contamination cannot be detected targeting only pig-specific fecal markers. Thus, new hog lagoon markers have a better detection capacity for lagoon waste contamination, and in conjunction with a pig fecal marker, provide a more comprehensive and accurate detection of hog lagoon waste contamination in susceptible watersheds.

Assessing hydrological effects of human interventions on coastal systems: numerical applications to the Venice Lagoon

NASA Astrophysics Data System (ADS)

Ferrarin, C.; Ghezzo, M.; Umgiesser, G.; Tagliapietra, D.; Camatti, E.; Zaggia, L.; Sarretta, A.

2013-05-01

The hydrological consequences of historical, contemporary and future human activities on a coastal system were investigated by means of numerical models. The changes in the morphology of the Lagoon of Venice during the last century result from the sedimentological response to the combined effects of human interventions on the environment and global changes. This study focuses on changes from 1927 to 2012 and includes the changes planned for the protection of the city of Venice from storm surges and exceptional tides under future sea level rise scenarios. The application of a hydrodynamic model allowed for the analysis of the morphological effects on the lagoon circulation, the interaction with the sea and the internal mixing processes. The absolute values of the exchange between the lagoon and sea increased from 1927 to 2002 (from 3900 to 4600 m3 s-1), while the daily fraction of lagoon water volume exchanged decreased. At the same time, the flattening of the lagoon and loss of morphological heterogeneity enhanced the internal mixing processes driven by the tide and wind, reducing thus the overall water renewal time from 11.9 days in 1927 to 10.8 days in 2002. Morphological changes during the last decade reduced the water exchange through the inlets and induced an increase of the basin-wide water renewal time of 0.5 day. In the future, Venice Lagoon will evolve to a more restricted environment due to sea level rise, which increases the lagoon volume, and periodical closure of the lagoon from the sea during flooding events, which reduces the communication with the open sea. Therefore, the flushing capacity of the lagoon will decrease considerably, especially in its central part. Furthermore, some considerations on the impact of the hydromorphological changes on the ecological dynamics are proposed.

Design and installation of 3 photovoltaic village power systems in Tunisia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Darkazalli, G.; Rangaraian, A.; Scudder, L.

1982-09-01

A joint program sponsored by the United States Agency for International Development (U.S.A.I.D.) and the government of Tunisia was initiated to study the feasibility of using photovoltaics to supply electricity to remote villages in Tunisia. U.S.A.I.D. selected the NASA Lewis Research Center to implement the installation of three photovoltaic systems in the Tunisian village of Hammam Biadha Sud. In a competitive procurement, NASA selected a team proposed by the Solar Power Corporation, TriSolar Corporation, Esso Standard Tunisie and Development Sciences, Inc. to design and install the systems and train the villagers in the use of photovoltaics. The Tunisian Government counterpartmore » to NASA, is STEG, the Tunisian electrical generation authority. An overview of the systems designs is presented in this paper.« less

Hubble reveals heart of Lagoon Nebula

NASA Image and Video Library

2010-09-22

Image release date September 22, 2010 To view a video of this image go here: www.flickr.com/photos/gsfc/5014452203 Caption: A spectacular new NASA/ESA Hubble Space Telescope image reveals the heart of the Lagoon Nebula. Seen as a massive cloud of glowing dust and gas, bombarded by the energetic radiation of new stars, this placid name hides a dramatic reality. The Advanced Camera for Surveys (ACS) on the NASA/ESA Hubble Space Telescope has captured a dramatic view of gas and dust sculpted by intense radiation from hot young stars deep in the heart of the Lagoon Nebula (Messier 8). This spectacular object is named after the wide, lagoon-shaped dust lane that crosses the glowing gas of the nebula. This structure is prominent in wide-field images, but cannot be seen in this close-up. However the strange billowing shapes and sandy texture visible in this image make the Lagoon Nebula’s watery name eerily appropriate from this viewpoint too. Located four to five thousand light-years away, in the constellation of Sagittarius (the Archer), Messier 8 is a huge region of star birth that stretches across one hundred light-years. Clouds of hydrogen gas are slowly collapsing to form new stars, whose bright ultraviolet rays then light up the surrounding gas in a distinctive shade of red. The wispy tendrils and beach-like features of the nebula are not caused by the ebb and flow of tides, but rather by ultraviolet radiation’s ability to erode and disperse the gas and dust into the distinctive shapes that we see. In recent years astronomers probing the secrets of the Lagoon Nebula have found the first unambiguous proof that star formation by accretion of matter from the gas cloud is ongoing in this region. Young stars that are still surrounded by an accretion disc occasionally shoot out long tendrils of matter from their poles. Several examples of these jets, known as Herbig-Haro objects, have been found in this nebula in the last five years, providing strong support for

Modelling alpha-diversities of coastal lagoon fish assemblages from the Mediterranean Sea

NASA Astrophysics Data System (ADS)

Riera, R.; Tuset, V. M.; Betancur-R, R.; Lombarte, A.; Marcos, C.; Pérez-Ruzafa, A.

2018-07-01

Coastal lagoons are marine ecosystems spread worldwide with high ecological value; however, they are increasingly becoming deteriorated as a result of anthropogenic activity. Their conservation requires a better understanding of the biodiversity factors that may help identifying priority areas. The present study is focused on 37 Mediterranean coastal lagoons and we use predictive modelling approaches based on Generalized Linear Model (GLM) analysis to investigate variables (geomorphological, environmental, trophic or biogeographic) that may predict variations in alpha-diversity. It included taxonomic diversity, average taxonomic distinctness, and phylogenetic and functional diversity. Two GLM models by index were built depending on available variables for lagoons: in the model 1 all lagoons were used, and in the model 2 only 23. All alpha-diversity indices showed variability between lagoons associated to exogenous factors considered. The biogeographic region strongly conditioned most of models, being the first variable introduced in the models. The salinity and chlorophyll a concentration played a secondary role for the models 1 and 2, respectively. In general, the highest values of alpha-diversities were found in northwestern Mediterranean (Balearic Sea, Alborán Sea and Gulf of Lion), hence they might be considered "hotspots" at the Mediterranean scale and should have a special status for their protection.

Pan-European management of coastal lagoons: A science-policy-stakeholder interface perspective

NASA Astrophysics Data System (ADS)

Lillebø, Ana I.; Stålnacke, Per; Gooch, Geoffrey D.; Krysanova, Valentina; Bielecka, Małgorzata

2017-11-01

The main objective of the work carried out in the scope of a three years collaborative research project was to develop science-based strategies and a decision support framework for the integrated management of coastal lagoons and their catchments and, in this context, to enhance connectivity between research and policymaking. In this paper our main objective is to share the lessons learned from the innovative methodology used throughout the project. To achieve the proposed objectives, the multidisciplinary scientific knowledge in the project team was combined and integrated with the knowledge and views of local stakeholders of four selected European coastal lagoons, using a three step participatory approach. With this innovative approach, which included the usage of eco-hydrological and water quality-modelling tools, the team developed and analyzed integrated scenarios of possible economic development and environmental impacts in four European lagoons and their catchments. These scenarios were presented and discussed with stakeholders, giving rise to management recommendations for each case study lagoon. Results show that some management options might be transferrable to other European lagoons having similar climatic, geophysical and socio-economic settings. In management terms, the project output provides a set of policy guidelines derived from the different analyses conducted and proposes initiatives concerning management implementation in a local-regional-national-European setting.

Lagoon-sea exchanges, nutrient dynamics and water quality management of the Ria Formosa (Portugal)

NASA Astrophysics Data System (ADS)

Newton, Alice; Mudge, Stephen M.

2005-02-01

Historical data from the Ria Formosa lagoon are classified according to the EEA 2001 guidelines to provide a frame of reference to evaluate the effect of management during the implementation of the environmental legislative Directives. Water samples from the Ria Formosa lagoon were significantly enriched in nitrogen (NH 4+ NO 2- and NO 3-) with respect to the adjacent coastal waters indicating that inputs from sewage, agricultural runoff and benthic fluxes were not fully assimilated within the lagoon. Tidal flushing was insufficient in the inner areas of the lagoon to remove or effectively dilute these inputs. Enrichment was most severe close to the urban centres of Faro and Olhão, as well as in the Gilão Estuary and the shallow extremities. Dissolved oxygen undersaturation (mean 75% during daylight hours) was associated with the area close to the sewage outlets of Faro. In the shallow west end of the lagoon during summer, dissolved oxygen supersaturation reached 140% during the day but fell to 50% at night. Classification using the EEA (2001) guidelines suggests the system is "poor" or "bad" with respect to phosphate concentrations for the majority of the year and "poor" in nitrogen contamination during the autumn rainy period. Due to the high overall nitrogen load in the lagoon, there is a net export to the coastal waters, especially during November and December, and phosphate only becomes limiting briefly during the spring bloom (April). Therefore, substantial phytoplankton populations may be supported year-round in the lagoon. The consequences of water quality deterioration in the Ria Formosa would negatively affect the lagoon as a regional resource, important for its ecological, economic and recreational value. The industries most affected would be tourism, fisheries and aquaculture. Management options include Urban Waste Water Treatment, dredging, artificial inlets, limits on urban development and changes in agricultural practices.

CISOCUR - Residence time modelling in the Curonian Lagoon and validation through stable isotope measurements

NASA Astrophysics Data System (ADS)

Umgiesser, Georg; Razinkovas-Baziukas, Arturas; Zemlys, Petras; Ertürk, Ali; Mėžinė, Jovita

2015-04-01

The spatial pattern of the hydrodynamic circulation of the Curonian lagoon, the largest European coastal lagoon, is still little understood. In absence of automatic current registration data all the existing models relied mostly on such data as water levels leaving high level of uncertainty. Here we present CISOCUR, a new project financed by European Social Fund under the Global Grant measure. The project applies a new methodology that uses the carbon stable isotope (SI) ratio of C12 and C13 that characterize different water sources entering the lagoon and may be altered by internal kinetic processes. Through the tracing of these isotope ratios different water masses can be identified. This gives the possibility to validate several hypotheses of water circulation and validate hydrodynamic models. In particular it will be possible to 1) trace water masses entering the lagoon through the Nemunas and the Klaipeda strait; 2) test the hypothesis of sediment transport mechanisms inside the lagoon; 3) evaluate the importance of physical forcing on the lagoon circulation. The use of a hydrodynamic finite element model, coupled with the SI method, will allow for a realistic description of the transport processes inside the Curonian lagoon. So the main research goal is to apply the stable isotope tracers and a finite element model to determine the circulation patterns in the Curonian lagoon. Here we show how the SI analysis was used to validate the hydrodynamic model on the basis of residence time. The average residence time of the Nemunas waters is estimated through SI data and is then compared with the model data computed through standard algorithms. Seasonal changes of carbon content are taken care of through a preliminary application of a carbon kinetic model. The results are compared to literature data.

The spectrum of presumed tubercular uveitis in Tunisia, North Africa.

PubMed

Khochtali, Sana; Gargouri, Salma; Abroug, Nesrine; Ksiaa, Imen; Attia, Sonia; Sellami, Dorra; Feki, Jamel; Khairallah, Moncef

2015-10-01

The purpose of this study was to analyze the spectrum of presumed tubercular uveitis in Tunisia, North Africa. We retrospectively reviewed the clinical records of 38 patients (65 eyes) diagnosed with presumed tubercular uveitis at two referral centers in Tunisia, between January 2009 and December 2011. Mean age at presentation was 42.7 years. Twenty-four patients were women (63.2%) and 14 (36.8%) were men. Twenty-three eyes (35.4%) had posterior uveitis, 21 eyes (32.3%) had intermediate uveitis, 13 eyes (20%) had panuveitis, and 8 eyes (12.3%) had anterior uveitis. Ocular findings included vitritis in 67.7% of eyes, posterior synechiae in 47.7%, multifocal non-serpiginoid choroiditis in 23.1%, multifocal serpiginoid choroiditis in 21.5%, periphlebitis in 21.5%, and mutton-fat keratic precipitates in 20%. Anti-tubercular treatment was prescribed in 33 patients (86.8%) and was associated with systemic corticosteroids in 20 patients (52.6%) and periocular injections of corticosteroids in four patients (10.5%). After a mean follow-up of 14.2 months (range, 10-58), inflammation was controlled, with a significant improvement in visual acuity (VA) (p = 0.028). However, recurrences developed in two patients (5.3%). Final VA was better than 20/40 in 27 eyes (41.5%) and less than 20/200 in five eyes (7.7%). In Tunisia, all anatomic types are possible in tuberculosis-associated uveitis, but posterior and intermediate uveitis are more frequent. Vitritis, posterior synechiae, multifocal serpiginoid or non-serpiginoid choroiditis, and periphlebitis are the most common manifestations.

Spatial Variation in Development of Epibenthic Assemblages in a Coastal Lagoon

NASA Astrophysics Data System (ADS)

Benedetti-Cecchi, L.; Rindi, F.; Bertocci, I.; Bulleri, F.; Cinelli, F.

2001-05-01

Spatial and temporal patterns in colonization of epibenthic assemblages were measured in a coastal lagoon on the west coast of Italy using recruitment panels. It was proposed that if the ecological processes influencing development of assemblages were homogeneous within the lagoon, then there should be no differences in mean cover of colonists nor in spatial patterns of variance in abundance in different areas of the lagoon. In contrast, heterogeneity in ecological processes affecting development would be revealed by spatial variability in colonization. To test these hypotheses, two sticks each with five replicate panels were placed 3-5 m apart in each of two sites 30-100 m apart in each of three locations 500-100 m apart; the experiment was repeated three times between April and December 1999, using new sites at each location each time. The results revealed considerable spatial variation in the structure of developing assemblages across locations. There were significant Location or Time×Location effects in the mean abundance of common taxa, such as Enteromorpha intestinalis , Ulva rigida, Cladophora spp., bryozoans and serpulids. Patterns in spatial variation differed among locations for these organisms. Collectively, the results supported a model of spatial heterogeneity in intensity of processes influencing patterns of recruitment and development of epibenthic assemblages in the Lagoon of Orbetello. The implications of these results for management of environmental problems in complex, variable habitats such as coastal lagoons, are discussed.

Phosphorus recovery from anaerobic swine lagoon sludge using the quick wash process

USDA-ARS?s Scientific Manuscript database

Long term accumulation of sludge in anaerobic swine lagoons reduces its storage volume and ability to treat waste. Usually, excess accumulation of lagoon sludge is removed using pumping dredges. The dredged sludge is then land applied at agronomic rates according to its nutrient content. The accumul...

Phosphorus recovery from anaerobic swine lagoon sludge using the quick wash process

USDA-ARS?s Scientific Manuscript database

Long term and significant accumulation of sludge in anaerobic swine lagoons reduces its storage volume and ability to treat waste. Usually, excess accumulation of lagoon sludge is removed by dredging. The dredged sludge is then land applied at agronomic rates according to its nutrient content. Becau...

Tunisia-Japan Symposium: R&D of Energy and Material Sciences for Sustainable Society

NASA Astrophysics Data System (ADS)

Akimoto, Katsuhiro; Suzuki, Yoshikazu; Monirul Islam, Muhammad

2015-04-01

This volume of the Journal of Physics: Conference Series contains papers presented at the Tunisia-Japan Symposium: R&D of Energy and Material Sciences for Sustainable Society (TJS 2014) held at Gammarth, Republic of Tunisia on November 28-30, 2014. The TJS 2014 is based on the network of the Tunisia-Japan Symposium on Science, Society and Technology (TJASSST) which has been regularly organized since 2000. The symposium was focused on the technological developments of energy and materials for the realization of sustainable society. To generate technological breakthrough and innovation, it seems to be effective to discuss with various fields of researchers such as solid-state physicists, chemists, surface scientists, process engineers and so on. In this symposium, there were as many as 109 attendees from a wide variety of research fields. The technical session consisted of 106 contributed presentations including 3 plenary talks and 7 key-note talks. We hope the Conference Series and publications like this volume will contribute to the progress in research and development in the field of energy and material sciences for sustainable society and in its turn contribute to the creation of cultural life and peaceful society.

Brominated Flame Retardants in Sediments of Four Coastal Lagoons of Yucatan, Mexico.

PubMed

Valenzuela-Sánchez, I S; Gold-Bouchot, G; Hernández-Núñez, E; Barrientos-Medina, R C; Garza-Gisholt, E; Zapata-Pérez, O

2018-05-02

We examined the sediments of four coastal lagoons (Ria Lagartos, Bocas de Dzilam, Laguna de Chelem and Ria Celestun) from the state of Yucatan, Mexico, for three widely used commercial polybrominated diphenyl ethers formulations (penta-, octa- and deca-BDE). The most commonly found congeners in all four lagoons were BDEs 47, 99 and 100 (all in the penta-BDE formulation) and BDE209 (deca-BDE formulation). The greatest variety and highest concentrations of brominated flame retardants were found in Ria Lagartos, which also showed the highest BDE 100 concentration (24.129 ng/g). Hexabromocyclododecane was found in all lagoons, but at lower concentrations than those of the various polybrominated diphenyl ethers. Dispersal routes of these compounds are discussed, such as a ring of sinkholes (cenotes) adjacent to the lagoons. Moreover, electronic waste is a serious problem because municipal landfills have been the primary disposal method for these wastes and therefore represent a reservoir of brominated fire retardants.

Morphological characterization of a Daucus L. germplasm collection in Tunisia

USDA-ARS?s Scientific Manuscript database

The genus Daucus includes about 25 recognized species worldwide. Northern Africa represents a major center of diversity of Daucus, with Tunisia containing at least 12 species and six subspecies. We assessed morphological diversity from a Daucus L. germplasm collection of 103 accessions at the Nation...

Accuracy of vertical radial plume mapping technique in measuring lagoon gas emissions.

PubMed

Viguria, Maialen; Ro, Kyoung S; Stone, Kenneth C; Johnson, Melvin H

2015-04-01

Recently, the U.S. Environmental Protection Agency (EPA) posted a ground-based optical remote sensing method on its Web site called Other Test Method (OTM) 10 for measuring fugitive gas emission flux from area sources such as closed landfills. The OTM 10 utilizes the vertical radial plume mapping (VRPM) technique to calculate fugitive gas emission mass rates based on measured wind speed profiles and path-integrated gas concentrations (PICs). This study evaluates the accuracy of the VRPM technique in measuring gas emission from animal waste treatment lagoons. A field trial was designed to evaluate the accuracy of the VRPM technique. Control releases of methane (CH4) were made from a 45 m×45 m floating perforated pipe network located on an irrigation pond that resembled typical treatment lagoon environments. The accuracy of the VRPM technique was expressed by the ratio of the calculated emission rates (QVRPM) to actual emission rates (Q). Under an ideal condition of having mean wind directions mostly normal to a downwind vertical plane, the average VRPM accuracy was 0.77±0.32. However, when mean wind direction was mostly not normal to the downwind vertical plane, the emission plume was not adequately captured resulting in lower accuracies. The accuracies of these nonideal wind conditions could be significantly improved if we relaxed the VRPM wind direction criteria and combined the emission rates determined from two adjacent downwind vertical planes surrounding the lagoon. With this modification, the VRPM accuracy improved to 0.97±0.44, whereas the number of valid data sets also increased from 113 to 186. The need for developing accurate and feasible measuring techniques for fugitive gas emission from animal waste lagoons is vital for livestock gas inventories and implementation of mitigation strategies. This field lagoon gas emission study demonstrated that the EPA's vertical radial plume mapping (VRPM) technique can be used to accurately measure lagoon gas

Nutrient budgets and trophic state in a hypersaline coastal lagoon: Lagoa de Araruama, Brazil

NASA Astrophysics Data System (ADS)

Souza, Marcelo F. L.; Kjerfve, Björn; Knoppers, Bastiaan; Landim de Souza, Weber F.; Damasceno, Raimundo N.

2003-08-01

Lagoa de Araruama in the state of Rio de Janeiro, Brazil, is a hypersaline lagoon with salinity varying spatially from 45 to 56. We collected water samples during monthly cruises throughout the lagoon, and along the streams feeding the system, from April 1991 to March 1992. Nutrients and other water quality parameters exhibited great spatial and temporal variations. Mass balance calculations indicate large amounts of anthropogenic nutrient inputs. The data indicate that the lagoon currently is oligotrophic but is in a state of transition to become a mesotrophic system. Molar dissolved inorganic nitrogen:dissolved inorganic phosphorus (DIN/DIP) varied between 2.2:1 and 659:1 with a volume-weighted average of 22:1. The high DIN/DIP ratio contrasts with that found in nearby lagoons, suggesting that phytoplankton primary production is limited by phosphorus in Lagoa de Araruama. The major loss of DIP is apparently driven by biological assimilation and diagenic reactions in the sediments. Calculations indicate that the lagoon is slightly net autotrophic at +0.9 mol C m -2 yr -1. This suggests that the biomass of the primary producers is restricted by phosphorus availability. Phosphorus retention in the sediment and the hypersaline state of the lagoon prevent changes in autotrophic communities and the formation of eutrophic conditions.

Spatial distribution, enrichment, and source of environmentally important elements in Batticaloa lagoon, Sri Lanka.

PubMed

Adikaram, Madurya; Pitawala, Amarasooriya; Ishiga, Hiroaki; Jayawardana, Daham

2017-01-01

The present paper is the first documentation of distribution and contamination status of environmentally important elements of superficial sediments in the Batticaloa lagoon that is connected to the largest bay of the world. Surface sediment samples were collected from 34 sites covering all over the lagoon. Concentrations of elements such as As, Cr, Cu, Fe, Nb, Ni, Pb, Sc, Sr, Th, V, Y, Zn, and Zr were measured by X-ray florescence analysis. Geochemically, the lagoon has three different zones that were influenced mainly by fresh water sources, marine fronts, and intermediate mixing zones. The marine sediment quality standards indicate that Zr and Th values are exceeded throughout the lagoon. According to the freshwater sediment quality standards, Cr levels of all sampling sites exceed the threshold effect level (TEL) and 17 % of them are even above the probable effect level (PEL). Most sampling sites of the channel discharging areas show minor enrichment of Cu, Ni, and Zn with respect to the TEL. Contamination indices show that the lagoon mouth area is enriched with As. Statistical analysis implies that discharges from agricultural channel and marine fluxes of the lagoon effects on the spatial distribution of measured elements. Further research is required to understand the rate of contamination in the studied marine system.

Clinical epidemiological and molecular aspects of rubella outbreak with high number of neurological cases, Tunisia 2011-2012.

PubMed

Messedi, Emna; Fki-Berrajah, Lamia; Gargouri, Saba; Chouikha, Anissa; Chaari, Anis; Bouaziz, Mounir; Jallouli, Hajer; Yahia, Ahlem Ben; Hammami, Adnene; Triki, Henda; Karray-Hakim, Héla

2014-10-01

A large and unusually prolonged rubella outbreak occurred in Tunisia from April 2011 to July 2012 and was characterized by a high number of neurological cases. To describe the outbreak and to perform virus genotyping of isolated virus strains. From January 2011 to December 2012, 5000 sera for serological diagnosis of acute rubella and 31 cerebrospinal fluid from patients with neurological symptoms were tested for the presence of rubella immunoglobulins G and M. Real-time PCR was performed on 49 throat swabs, 21 cerebrospinal fluid and 27 serum samples. Positive samples were assessed for virus genotyping by sequencing and the obtained sequences were compared to those previously isolated in the country. Acute rubella was confirmed in 280 patients including 15 neonates, 217 children and adults with mild rash and 48 patients with severe rubella (mainly encephalitis, n = 39). Most of acquired rubella cases (60.7%) were aged over 12 years with a male predominance observed in the age group 12-25 years (79%). Females belonged essentially to the unvaccinated age groups under 12 and over 25 years. Among the 23 samples tested positive by real-time PCR, six could be genotyped and clustered with either the 1E genotype, previously detected in Tunisia, or the 2B genotype which has never been isolated in Tunisia before. Gender and age distributions of the patients reflect the impact of the selective rubella vaccination program adopted in Tunisia since 2005. Genotype 1E continues to circulate and genotype 2B was probably recently introduced in Tunisia. Copyright © 2014 Elsevier B.V. All rights reserved.

Risk Assessment for the Explosive Washout Lagoons (Site 4), Umatilla Depot Activity Hermiston, Oregon

DTIC Science & Technology

1992-03-01

Activity .............................. 2 2-2 Explosive Washout Lagoons (Site 4) and Washout Plant Area ............................... 2-3 3-1 Site 4...ponds for liquid wastes from bomb-washing operations in the washout plant . The measured dimensions of the flat bottoms of the two lagoons are 30 by 80...explosives washout plant system was drained, flushed, and cleaned approximately once each week from the mid-1950s until 1965. The lagoons received all of the

[The virological and epidemiological aspects of human adenoviral conjunctivitis in Tunisia].

PubMed

Fedaoui, N; Ben Ayed, N; Ben Yahia, A; Matri, L; Nacef, L; Triki, H

2017-01-01

Human adenoviruses (HAdV) are the main cause of viral conjunctivitis. In Tunisia and North Africa more generally, there is no regular nationwide surveillance program that monitors viruses causing conjunctivitis and keratoconjunctivitis. In this study, we report the results of HAdV screening in conjunctival samples collected for over 14 years in Tunisia. A total of 282 conjunctival samples received between 2000 and 2013 were investigated. Detection and identification of genotype were performed by PCR-sequencing at the hexon gene; 64.5% of samples (n=182) revealed positive by PCR detection without correlation noted between infection, age, sex, social class or clinical manifestations of viral conjunctivitis. HAdV-D8 was the largely predominant genotype in Tunisia, representing 81.3% of all isolates, and was detected continuously from 2000 to 2013. Minor co-circulating genotypes were also identified - HAdV-E4, HAdV-B3, B55 and HAdV-B7 - accounting for 10.7%, 4.9%, 1.9% and 0.9% of isolates, respectively. In conclusion, this work reports epidemiological data on adenoviral conjunctivitis from a region where such information is very scarce and contributes to a better knowledge of the worldwide distribution of causative genotypes. It also presents an approach for the identification of circulating HAdV in the country and demonstrates the importance of molecular tools for both detection and identification of genotypes, which allow rapid virological investigation, especially during epidemics. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Lagoon microbialites on Isla Angel de la Guarda and associated peninsular shores, Gulf of California (Mexico)

NASA Astrophysics Data System (ADS)

Johnson, Markes E.; Ledesma-Vázquez, Jorge; Backus, David H.; González, Maria R.

2012-07-01

Examples of two closed lagoons with extensive growth of Recent microbialites showing variable surface morphology and internal structure are found on Isla Angel de la Guarda in the Gulf of California. Comparable lagoonal microbialites also occur ashore from Ensenada El Quemado on the adjacent peninsular mainland of Baja California. The perimeters of all three lagoons feature crusted structures indicative of thrombolites with a knobby surface morphology 2 cm to 3 cm in relief and internal clotting without any sign of laminations. Outward from this zone, thrombolitic construction thins to merge with a white calcified crust below which a soft substratum of dark organic material 4 cm to 6 cm in thickness is concealed. The substratum is laminated and heavily mucilaginous, as observed along the edges of extensive shrinkage cracks in the overlying crust. The thrombolitic crust is anchored to the shore, while the thinner crust and associated stromatolitic mats float on the surface of the lagoons. Laboratory cultures of the dark organic material yielded the solitary cyanobacterium Chroococcidiopsis as the predominant taxon interspersed with filamentous forms. In decreasing order of abundance, other morphotypes present include Phormidium, Oscillatoria, Geitlerinema, Chroococus, and probably Spirulina. The larger of the two island lagoons follows an east-west azimuth and covers 0.225 km2, while the smaller lagoon has a roughly north-south axis and covers only 0.023 km2. The salinity of water in the smaller lagoon was measured as148 ppt. Pliocene strata along the edge of the smaller modern lagoon include siltstone bearing calcified platelets suggestive of a microbial origin. Dry lagoons abandoned during the later Quaternary occur inland at higher elevations on the island, but retain no fossils except for sporadic white crusts cemented on cobbles around distinct margins. Raised Quaternary lagoons parallel to the big lagoon on Isla Angel de la Guarda are partly obscured by flood

Scattering study of the Ne + NeH+(v0 = 0, j0 = 0) → NeH+ + Ne reaction on an ab initio based analytical potential energy surface

NASA Astrophysics Data System (ADS)

Koner, Debasish; Barrios, Lizandra; González-Lezana, Tomás; Panda, Aditya N.

2016-01-01

Initial state selected dynamics of the Ne + NeH+(v0 = 0, j0 = 0) → NeH+ + Ne reaction is investigated by quantum and statistical quantum mechanical (SQM) methods on the ground electronic state. The three-body ab initio energies on a set of suitably chosen grid points have been computed at CCSD(T)/aug-cc-PVQZ level and analytically fitted. The fitting of the diatomic potentials, computed at the same level of theory, is performed by spline interpolation. A collinear [NeHNe]+ structure lying 0.72 eV below the Ne + NeH+ asymptote is found to be the most stable geometry for this system. Energies of low lying vibrational states have been computed for this stable complex. Reaction probabilities obtained from quantum calculations exhibit dense oscillatory structures, particularly in the low energy region and these get partially washed out in the integral cross section results. SQM predictions are devoid of oscillatory structures and remain close to 0.5 after the rise at the threshold thus giving a crude average description of the quantum probabilities. Statistical cross sections and rate constants are nevertheless in sufficiently good agreement with the quantum results to suggest an important role of a complex-forming dynamics for the title reaction.

Socio-economic appraisal of fishing community in Pulicat lagoon, south east coast of India: case study.

PubMed

Devi, V Vandhana; Krishnaveni, M

2012-10-01

Assessment of socio-economic issues of fishing community is an important aspect in framing a strategy for the preservation of eco-systems which leads to sustainable lagoon management. The present investigation analyses the current potential socio-economic status of the fishing community of Pulicat lagoon, the second largest lagoon in India. The socio-economic indicators considered in the study include demography, economic aspects, social aspects and occupation details. The relevant details were collected from 300 fisher folk family by conducting field survey through a well prepared questionnaire in the villages around Pulicat lagoon. The data analysis was done using Statistical Program for Social Sciences (SPSS) to assess the adequacy and precision of the collected data. The important and encouraging socio-economic indicators identified from the field survey for effective lagoon management includes significant presence of younger generation in the region; affinity and self-belongingness of fisher folk towards the lake; better economic status and moderate education level; appreciable fishing income and affinity towards fishing profession. It is emphasized to motivate the fisher folk to improve their work attitude for betterment in economic status. The pertinent lagoon issues, comprising seasonal variation, local fishing issues, pollution from industries, water intake to thermal power plant which directly or indirectly affects the socio-economic status of fishing community, also need much emphasis while proposing sustainable lagoon management system. The information and observation from this study will be very helpful in formulating management policies on the conservation of the Pulicat lagoon ecosystem.

The atypical hydrodynamics of the Mayotte Lagoon (Indian Ocean): Effects on water age and potential impact on plankton productivity

NASA Astrophysics Data System (ADS)

Chevalier, C.; Devenon, J. L.; Pagano, M.; Rougier, G.; Blanchot, J.; Arfi, R.

2017-09-01

In mesotidal lagoons of the Indian Ocean, the coral reef barrier may be temporarily submerged at high tide and partially exposed at low tide, and this may cause unusual lagoon dynamics. A field measurement campaign was conducted in the north-east Mayotte Lagoon in order to understand these processes. An experimental approach was used, combining measurements taken by 1) a side-mounted Acoustic Doppler Current Profiler (ADCP) on a moving boat along transects through the reef passages (17 transects) and 2) by more conventional high-resolution moored ADCP measurements. A specific tidal analysis methodology was used to determine the spatial variability of the velocity. The tidal hydrodynamics within the lagoon were determined using a numerical model and then analyzed. The tide acted as a quasi-progressive forced wave in the lagoon: at low tide, water entered through the south passage, over the reef and left the lagoon through the north passage. This flow was reversed at high tide. The tide-driven quasi-progressive wave created a specific lagoon dynamics. Contrary to most other channel lagoons, the flow over the reef was mainly outward. This increases the inflow through the passages, which renews the water in the lagoon as shown by the indicators of age and origin of the water inside the lagoon. This study also showed the importance of these indicators for better understanding the variations and levels of plankton biomass (with chlorophyll concentration as proxy) which is quite high in this lagoon.

Groundwater and porewater as major sources of alkalinity to a fringing coral reef lagoon (Muri Lagoon, Cook Islands)

NASA Astrophysics Data System (ADS)

Cyronak, T.; Santos, I. R.; Erler, D. V.; Eyre, B. D.

2013-04-01

To better predict how ocean acidification will affect coral reefs, it is important to understand how biogeochemical cycles on reefs alter carbonate chemistry over various temporal and spatial scales. This study quantifies the contribution of shallow porewater exchange (as quantified from advective chamber incubations) and fresh groundwater discharge (as traced by 222Rn) to total alkalinity (TA) dynamics on a fringing coral reef lagoon along the southern Pacific island of Rarotonga over a tidal and diel cycle. Benthic alkalinity fluxes were affected by the advective circulation of water through permeable sediments, with net daily flux rates of carbonate alkalinity ranging from -1.55 to 7.76 mmol m-2 d-1, depending on the advection rate. Submarine groundwater discharge (SGD) was a source of TA to the lagoon, with the highest flux rates measured at low tide, and an average daily TA flux of 1080 mmol m-2 d-1 at the sampling site. Both sources of TA were important on a reef-wide basis, although SGD acted solely as a delivery mechanism of TA to the lagoon, while porewater advection was either a sink or source of TA dependent on the time of day. This study describes overlooked sources of TA to coral reef ecosystems that can potentially alter water column carbonate chemistry. We suggest that porewater and groundwater fluxes of TA should be taken into account in ocean acidification models in order to properly address changing carbonate chemistry within coral reef ecosystems.

Modeling olive-crop forecasting in Tunisia

NASA Astrophysics Data System (ADS)

Ben Dhiab, Ali; Ben Mimoun, Mehdi; Oteros, Jose; Garcia-Mozo, Herminia; Domínguez-Vilches, Eugenio; Galán, Carmen; Abichou, Mounir; Msallem, Monji

2017-05-01

Tunisia is the world's second largest olive oil-producing region after the European Union. This paper reports on the use of models to forecast local olive crops, using data for Tunisia's five main olive-producing areas: Mornag, Jemmel, Menzel Mhiri, Chaal, and Zarzis. Airborne pollen counts were monitored over the period 1993-2011 using a Cour trap. Forecasting models were constructed using agricultural data (harvest size in tonnes of fruit/year) and data for several weather-related and phenoclimatic variables (rainfall, humidity, temperature, Growing Degree Days, and Chilling). Analysis of these data revealed that the amount of airborne pollen emitted over the pollen season as a whole (i.e., the Pollen Index) was the variable most influencing harvest size. Findings for all local models also indicated that the amount, timing, and distribution of rainfall (except during blooming) had a positive impact on final olive harvests. Air temperature also influenced final crop yield in three study provinces (Menzel Mhiri, Chaal, and Zarzis), but with varying consequences: in the model constructed for Chaal, cumulative maximum temperature from budbreak to start of flowering contributed positively to yield; in the Menzel Mhiri model, cumulative average temperatures during fruit development had a positive impact on output; in Zarzis, by contrast, cumulative maximum temperature during the period prior to flowering negatively influenced final crop yield. Data for agricultural and phenoclimatic variables can be used to construct valid models to predict annual variability in local olive-crop yields; here, models displayed an accuracy of 98, 93, 92, 91, and 88 % for Zarzis, Mornag, Jemmel, Chaal, and Menzel Mhiri, respectively.

Evidence of North Africa’s Green Revolution Preserved in Sedimentary Organic Matter Deposited in Three Coastal Lagoons.

EPA Science Inventory

Because of longer residence times and limited mixing in coastal lagoons, the impacts of anthropogenic nutrient loading to lagoon food webs are often more pronounced than in other coastal ecosystems. For these reasons, many lagoons also provide an excellent environment for the dep...

Decline of phosphorus, copper, and zinc in anaerobic lagoon columns receiving pretreated influent

USDA-ARS?s Scientific Manuscript database

Confined swine production generates large volumes of wastewater typically stored and treated in anaerobic lagoons. These lagoons usually require a sludge management plan for their maintenance consisting of regular sludge removal by mechanical agitation and pumping followed by land application at agr...

The role of benthic macrophytes and their associated macroinvertebrate community in coastal lagoon resistance to eutrophication.

PubMed

Lloret, Javier; Marín, Arnaldo

2009-12-01

Eutrophication is widely recognised as one of the major menaces to coastal environments, particularly enclosed bays and lagoons. Although there is a general understanding of the consequences of eutrophication in these systems, there is a lack of sufficient knowledge concerning biotic feedbacks that influence eutrophication patterns and the resistance capacity of coastal environments. In this paper, the isotope ratios of main producers and consumers of a Mediterranean lagoon were examined in order to elucidate the fate of anthropogenic inputs from the main watercourse flowing into the lagoon. The results of the study of stable isotope data in the Mar Menor lagoon reflected that the whole benthic community plays an important role as a natural 'filter' that removes excess nutrients from the water column and stores them in the sediments, thereby enhancing lagoon resistance to eutrophication.

Living in a coastal lagoon environment: photosynthetic and biochemical mechanisms of key marine macroalgae.

PubMed

García-Sánchez, Marta; Korbee, Nathalie; Pérez-Ruzafa, Isabel María; Marcos, Concepción; Figueroa, Félix L; Pérez-Ruzafa, Ángel

2014-10-01

The physiological status of Cystoseira compressa, Padina pavonica and Palisada tenerrima was studied by in vivo chlorophyll fluorescence, pigment content, stoichiometry (C:N), accumulation of UV photoprotectors and antioxidant activity; comparing their photosynthetic response in a coastal lagoon (Mar Menor) and in Mediterranean coastal waters. In general, the specimens reached their highest ETRmax in spring in the Lagoon, but in summer in the Mediterranean, coinciding with their maximum biomass peak. The species exhibited a dynamic photoinhibition. Except C. compressa, they showed a lower decrease in Fv/Fm and higher recovery rates in the Mediterranean populations when exposed to high irradiance. The higher salinity and temperature of the lagoon could impair the photoprotection mechanisms. The acclimation to lagoon environments is species-specific and involves complex regulatory mechanisms. The results underline the importance of N in repair, avoidance, quenching and scavenging mechanisms. In general, Lagoon specimens showed higher pigment concentration. Although xanthophylls play important photo-protective and antioxidant roles, the observed trend is more likely to be explained by the higher temperatures reached in the lagoon compared to Mediterranean. Therefore the studied photosynthetic and biochemical mechanisms can be effective not only for high irradiance, but also for higher temperatures in a climate change scenario, but are highly dependent on nutrient availability. Copyright © 2014 Elsevier Ltd. All rights reserved.

A Bayesian Network Model for Assessing Estrogen Fate and Transport in a Swine Waste Lagoon

PubMed Central

Lee, Boknam; Kullman, Seth W.; Yost, Erin; Meyer, Michael T.; Worley-Davis, Lynn; Reckhow, Kenneth H.

2017-01-01

Commercial swine waste lagoons are regarded as a major reservoir of natural estrogens, which have the potential to produce adverse physiological effects on exposed aquatic organisms and wildlife. However, there remains limited understanding of the complex mechanisms of physical, chemical, and biological processes that govern the fate and transport of natural estrogens within an anaerobic swine lagoon. To improve lagoon management and ultimately help control the offsite transport of these compounds from swine operations, a Bayesian network model was developed to predict estrogen fate and budget and compared against data collected from a commercial swine field site. In general, the model was able to predict the estrogen fate and budget in both the slurry and sludge stores within the swine lagoon. Sensitivity analysis within the model, demonstrated that the estrogen input loading from the associated barn facility was the most important factor in controlling estrogen concentrations within the lagoon slurry storage, while the settling rate was the most significant factor in the lagoon sludge storage. The degradation reactions were shown to be minor in both stores based on prediction of average total estrogen concentrations. Management scenario evaluations showed that the best possible management options to reduce estrogen levels in the lagoon are either to adjust the estrogen input loading from swine barn facilities or to effectively enhancing estrogen bonding with suspended solids through the use of organic polymers or inorganic coagulants. PMID:24798317

Southern Tunisia: A still high endemicity area for hepatitis A.

PubMed

Neffatti, Houcine; Lebraud, Patricia; Hottelet, Corinne; Gharbi, Jawher; Challouf, Taieb; Roque-Afonso, Anne-Marie

2017-01-01

Hepatitis A (HAV) and E (HEV) viruses are responsible for enterically transmitted hepatitis. Tunisia is reported to be of intermediate endemicity for HAV and of low seroprevalence for HEV; however, data from rural areas of South Tunisia are lacking. Sera from 216 asymptomatic pregnant women and from 92 patients with acute hepatitis were collected between October 2014 and November 2015. Total and IgM anti-HAV immunoglobulins and anti-HEV IgG and IgM were investigated. Anti-HAV IgM-positive samples were subjected to RT-PCR targeting the VP1/2A region and sequenced. HEV IgM positive samples and all samples from acute hepatitis patients were assessed for HEV RNA. Among pregnant women (mean age 32+/-8), HAV seroprevalence was 98.6%, none presented anti-HAV IgM; HEV seroprevalence was 5.1% and three presented weakly reactive anti-HEV IgM without detectable RNA. Among acute hepatitis patients (mean age 18.5 +/- 14), HEV seroprevalence was 19,5%, none presented anti-HEV IgM, nor HEV RNA. HAV seroprevalence exceeded 90% by age 5 and acute HAV infection was detected in 20 patients (21,7%), younger than patients with other hepatitis causes (9,8 years vs. 20,4 years, p = 0,004); 65% were male. Most acute HAV infections were observed in a coastal area where HAV infections represented 52% of hepatitis etiology. Phylogenetic analysis identified genotype IA strains, clustering close to previously published Tunisian sequences. The present study confirmed a low HEV endemicity and evidenced a still high level of HAV circulation in Southern Tunisia, suggesting distinct dissemination patterns for these viruses.

Southern Tunisia: A still high endemicity area for hepatitis A

PubMed Central

Neffatti, Houcine; Lebraud, Patricia; Hottelet, Corinne; Gharbi, Jawher; Challouf, Taieb

2017-01-01

Background Hepatitis A (HAV) and E (HEV) viruses are responsible for enterically transmitted hepatitis. Tunisia is reported to be of intermediate endemicity for HAV and of low seroprevalence for HEV; however, data from rural areas of South Tunisia are lacking. Methods Sera from 216 asymptomatic pregnant women and from 92 patients with acute hepatitis were collected between October 2014 and November 2015. Total and IgM anti-HAV immunoglobulins and anti-HEV IgG and IgM were investigated. Anti-HAV IgM-positive samples were subjected to RT-PCR targeting the VP1/2A region and sequenced. HEV IgM positive samples and all samples from acute hepatitis patients were assessed for HEV RNA. Results Among pregnant women (mean age 32+/-8), HAV seroprevalence was 98.6%, none presented anti-HAV IgM; HEV seroprevalence was 5.1% and three presented weakly reactive anti-HEV IgM without detectable RNA. Among acute hepatitis patients (mean age 18.5 +/- 14), HEV seroprevalence was 19,5%, none presented anti-HEV IgM, nor HEV RNA. HAV seroprevalence exceeded 90% by age 5 and acute HAV infection was detected in 20 patients (21,7%), younger than patients with other hepatitis causes (9,8 years vs. 20,4 years, p = 0,004); 65% were male. Most acute HAV infections were observed in a coastal area where HAV infections represented 52% of hepatitis etiology. Phylogenetic analysis identified genotype IA strains, clustering close to previously published Tunisian sequences. Conclusion The present study confirmed a low HEV endemicity and evidenced a still high level of HAV circulation in Southern Tunisia, suggesting distinct dissemination patterns for these viruses. PMID:28426700

Methane fluxes from tropical coastal lagoons surrounded by mangroves, Yucatán, Mexico

NASA Astrophysics Data System (ADS)

Chuang, P.-C.; Young, M. B.; Dale, A. W.; Miller, L. G.; Herrera-Silveira, J. A.; Paytan, A.

2017-05-01

Methane concentrations in the water column and emissions to the atmosphere were determined for three tropical coastal lagoons surrounded by mangrove forests on the Yucatán Peninsula, Mexico. Surface water dissolved methane was sampled at different seasons over a period of 2 years in areas representing a wide range of salinities and anthropogenic impacts. The highest surface water methane concentrations (up to 8378 nM) were measured in a polluted canal associated with Terminos Lagoon. In Chelem Lagoon, methane concentrations were typically lower, except in the polluted harbor area (1796 nM). In the relatively pristine Celestún Lagoon, surface water methane concentrations ranged from 41 to 2551 nM. Methane concentrations were negatively correlated with salinity in Celestún, while in Chelem and Terminos high methane concentrations were associated with areas of known pollution inputs, irrespective of salinity. The diffusive methane flux from surface lagoon water to the atmosphere ranged from 0.0023 to 15 mmol CH4 m-2 d-1. Flux chamber measurements revealed that direct methane release as ebullition was up to 3 orders of magnitude greater than measured diffusive flux. Coastal mangrove lagoons may therefore be an important natural source of methane to the atmosphere despite their relatively high salinity. Pollution inputs are likely to substantially enhance this flux. Additional statistically rigorous data collected globally are needed to better consider methane fluxes from mangrove-surrounded coastal areas in response to sea level changes and anthropogenic pollution in order to refine projections of future atmospheric methane budgets.

Fingerprints of lagoonal life: Migration of the marine flatfish Solea solea assessed by stable isotopes and otolith microchemistry

NASA Astrophysics Data System (ADS)

Dierking, Jan; Morat, Fabien; Letourneur, Yves; Harmelin-Vivien, Mireille

2012-06-01

The commercially important marine flatfish common sole (Solea solea) facultatively uses NW Mediterranean lagoons as nurseries. To assess the imprint left by the lagoonal passage, muscle carbon (C) and nitrogen (N) isotope values of S. solea juveniles caught in Mauguio lagoon in spring (shortly after arrival from the sea) and in autumn (before the return to the sea) were compared with values of juveniles from adjacent coastal marine nurseries. In addition, in the lagoon, sole otolith stable isotope (C and oxygen (O)) and elemental (11 elements) composition in spring and autumn, and the stable isotope composition (C and N) of organic matter sources in autumn, were determined. Overall, our data indicate that a distinct lagoonal signature existed. Specifically, lagoon soles showed a strong enrichment in muscle tissue 15N (>6‰) compared to their coastal relatives, likely linked to sewage inputs (see below), and a depletion in 13C (1-2‰), indicative of higher importance of 13C depleted terrestrial POM in the lagoon compared to coastal nurseries. In addition, over the time spent in the lagoon, sole otolith δ13C and δ18O values and otolith elemental composition changed significantly. Analysis of the lagoon sole foodweb based on C and N isotopes placed sediment particulate organic matter (POM) at the base. Seagrasses, formerly common but in decline in Mauguio lagoon, played a minor role in the detritus cycle. The very strong 15N enrichment of the entire foodweb (+7 to +11‰) compared to little impacted lagoons and coastal areas testified of important human sewage inputs. Regarding the S. solea migration, the analysis of higher turnover and fast growth muscle tissue and metabolically inert and slower growth otoliths indicated that soles arrived at least several weeks prior to capture in spring, and that no migrations took place in summer. In the autumn, the high muscle δ15N value acquired in Mauguio lagoon would be a good marker of recent return to the sea, whereas

Taphonomy of coral reefs from Southern Lagoon of Belize

DOE Office of Scientific and Technical Information (OSTI.GOV)

Westphall, M.J.; Ginsburg, R.N.

1985-02-01

The Southern Lagoon of the Belize barrier complex, an area of some 600 km/sup 2/, contains a tremendous number of lagoon reefs, which range in size from patches several meters across to rhomboidal-shaped structures several kilometers in their long dimension. These lagoon reefs are remarkable because they have Holocene sediment accumulations in excess of 13 m consisting almost entirely of coral debris and lime mud and sand, and rise up to 30 m above the surrounding lagoon floor with steeply sloping sides (50-80/sup 0/), yet are totally uncemented. The reef-building biota and their corresponding deposits were studied at a representativemore » reef, the rhomboidal complex of Channel Cay. As with many of the reefs in this area, the steeply sloping flanks of Channel Cay are covered mainly by the branched staghorn coral Acropora cervicornis and ribbonlike and platy growth of Agaricia spp. The living corals are not cemented to the substrate, but are merely intergrown. Fragmented pieces of corals accumulate with an open framework below the living community; this open framework is subsequently infilled by lime muds and sands produced mainly from bioerosion. Results from probing and coring suggest that the bafflestone fabric of coral debris and sediment extends at least 13 m into the subsurface. Radiocarbon-age estimates indicate these impressive piles of coral rubble and sediment have accumulated in the past 9000 yr (giving a minimum accumulation rate of 1.4 m/1000 yr) and illustrate the potential for significant carbonate buildups without the need for early lithification.« less

Biodiversity patterns of macrophyte and macroinvertebrate communities in two lagoons of Western Greece.

NASA Astrophysics Data System (ADS)

Fyttis, G.; Reizopoulou, S.; Papastergiadou, E.

2012-04-01

Aquatic macrophytes and benthic macroinvertebrates were studied seasonally (Spring, Autumn, Summer) between the years 2009 - 2011 in two coastal lagoons (Kotychi and Prokopos) located in Peloponnese, Greece, in order to investigate spatial and temporal biodiversity trends related to hydrological processes (degree of confinement, nitrates, phosphates, chl-a, total suspended materials, light irradiance, pH, salinity, temperature and dissolved oxygen). Kotychi lagoon presents a better communication with the sea, while Prokopos has a high degree of confinement. Both ecosystems seasonally receive freshwater input from streams. The submerged aquatic macrophytes constituted a major component of the ecosystems studied. In total, 22 taxa of aquatic macrophytes (angiosperms and macroalgae), 16 taxa for Kotychi (2 Rhodophyta, 8 Chlorophyta, 5 Magnoliophyta, 1 Streptophyta) and 14 taxa for Prokopos (1 Rhodophyta, 5 Chlorophyta, 5 Magnoliophyta, 3 Streptophyta) were found. Ruppia cirrhosa, and Potamogeton pectinatus were dominant in both lagoons. Kotychi lagoon was also dominated by Zostera noltii and Prokopos by Zannichellia pallustris ssp. pedicellata, while the biomass of aquatic species peaked during the summer periods, in both lagoons. The total number of macroinvertebrates found in the lagoons was 28 taxa for Kotychi and 19 for Prokopos. Chironomidae were dominant in both lagoons, while Kotychi was also dominated by Lekanesphaera monodi and Monocorophium insidiosum, and Prokopos by Ostracoda and Lekanesphaera monodi. Benthic diversity ranged from 1.33 to 2.57 in Kotychi and from 0.67 to 2.48 in Prokopos. Species richness, diversity, and abundance of benthic macroinvertebrates were strongly related to aquatic vegetation and to the degree of communication with the marine environment. Moreover, species richness and abundance of both macrophytes and macroinvertebrates were mainly dependent on depth, temperature, pH and concentration of total suspended materials (TSM). Results

Prevalence of cardiovascular risk factors in the urban population of Soussa in Tunisia.

PubMed

Ghannem, H; Hadj Fredj, A

1997-12-01

With the epidemiological transition phenomenon, Tunisia is now facing the growing prevalence of chronic diseases. Environmental and behavioural changes such as the adoption of new dietary habits and a sedentary lifestyle, and the stress of urbanization and of working conditions all lead to the rise in cardiovascular disease (CVD) risk factors. The aim of this study is to estimate the prevalence of the main CVD risk factors in an urban context. For this, we have undertaken a household epidemiological survey of a representative sample of the adult urban population of Soussa, Tunisia (n = 957). This study shows high prevalences of hypertension (blood pressure >160/95 mmHg) of 18.8 per cent with an adjusted rate of 15.6 per cent, history of diabetes of 10.2 per cent, and obesity (body mass index > 30) of 27.7 per cent [significantly higher in women (34.4 per cent)], android obesity 36 per cent, smoking habits 21.5 per cent [significantly higher in men (61.4 per cent)]. With this profile of CVD risk factors, Tunisia must implement a national strategy of primary prevention and heart health promotion in addition to the efforts recently made in secondary prevention of some chronic diseases such as hypertension and diabetes.

[Mycological and epidemiological aspects of tinea capitis in the Sousse region of Tunisia].

PubMed

Saghrouni, F; Bougmiza, I; Gheith, S; Yaakoub, A; Gaïed-Meksi, S; Fathallah, A; Mtiraoui, A; Ben Saïd, M

2011-01-01

Tinea capitis continues to be considered a public health problem in Tunisia. The purpose of our study was to investigate trends in the incidence and the mycological and epidemiological aspects of tinea capitis in the Sousse region (Central Tunisia). Our work is a retrospective study concerning all scalp samples taken by the parasitology laboratory of the Farhat Hached Hospital in Sousse, Tunisia, over a 26-year period (1983-2008). A total of 10,505 specimens were examined. Of these, 5593 were positive with positive direct examination and/or positive culture. The average incidence was 215 cases per year. Patients were aged under 12 years in 89.3% of cases. A total of 175 cases of tinea capitis in adults were diagnosed. Ten dermatophyte species were isolated: Trichophyton (T.) violaceum (66.7%), Microsporum (M.) canis (29.3%), T. schoenleinii (1.6%), T. mentagrophytes (1.1%), T. verrucosum (0.6%), T. tonsurans (0.2%), T. rubrum (0.2%), M. gypseum (0.1%), M. audouinii (0.03%) and M. nanum (0.01%). Our study showed a decrease in the annual incidence of tinea capitis over the study period with an evident decrease in trichophytic tinea and disappearance of favus giving way to microsporic and inflammatory tinea. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Observations of emperor geese feeding at Nelson Lagoon, Alaska

USGS Publications Warehouse

Petersen, Margaret R.

1983-01-01

Estuaries along the north side of the Alaska Peninsula provide essential habitat for most of the American population of Emperor Goose (Chen canagica) during migration (Petersen and Gill 1982). Most of the population passes through Nelson Lagoon in spring and fall, with over 40,000 birds recorded there (Gill et al 1981). Little is known about the feeding activity of Emperor Geese while they are in estuaries, and the importance of estuaries as staging areas during spring and fall migration is poorly understood. Here I report observations on the feeding activity of emperor Geese at one estuary (Nelson Lagoon).

Seismic reflection and structuring characterization of deep aquifer system in the Dakhla syncline (Cap Bon, North-Eastern Tunisia)

NASA Astrophysics Data System (ADS)

Bellali, Abir; Jarraya Horriche, Faten; Gabtni, Hakim; Bédir, Mourad

2018-04-01

The Dakhla syncline is located in the North-Eastern Tunisia. It is bounded by Abd El Rahmene anticline to the North-West, El Haouaria Graben to the North-East, Grombalia Graben to the South-West and the Mediterranean Sea to the East. The main aquifer reservoirs of Dakhla syncline are constituted by stacks of fluvial to deltaic Neogene sequences and carbonates. The interpretation of eight seismic reflection profiles, calibrated by wire line logging data of three oil wells, hydraulic wells and geologic field sections highlighted the impact of tectonics on the structuring geometry of aquifers and their distribution in elevated structures and subsurface depressions. Lithostratigraphic correlations and seismic profiles analysis through the syncline show that the principal aquifers are thickest within the central and northern part of the study area and thinnest to the southern part of the syncline. Seismic sections shows that the fracture/fault pattern in this syncline is mainly concentrated along corridors with a major direction of NW-SE and secondary directions of N-S, E-W and NE-SW with different release. This is proved by the complexity structure of Eastern Tunisia, resulted from the interaction between the African and Eurasiatic plates. Isochron maps of aquifers systems exhibited the structuring of this syncline in sub-surface characterized by important lateral and vertical geometric and thickness variations. Seismic sections L1, L2, L3, L4, L5 and petroleum wells showed an heterogeneous multilayer aquifers of Miocene formed by the arrangement of ten sandstone bodies, separated by impermeable clay packages. Oligo-Miocene deposits correspond to the most great potential aquifers, with respectively an average transmissivity estimated: Somaa aquifer 6.5 10-4 m2/s, Sandstone level aquifer 2.6 10-3 m2/s, Beglia aquifer 1.1 10-3 m2/s, Ain Ghrab aquifer 1.3 10-4 m2/s and Oligocene aquifer 2 10-3 m2/s. The interpretation of spatial variations of seismic units and the

International financial institutions and health in Egypt and Tunisia: change or continuity?

PubMed

Ismail, Sharif

2013-01-01

The revolutions in Egypt and Tunisia appeared to herald a re-casting of International Monetary Fund and World Bank policy across the region. Public pronouncements by the heads of both institutions in the months following February 2011 acknowledged flaws in their approach to macroeconomic advice, against a background of worsening socioeconomic indicators, widespread youth unemployment, and widening health inequalities. Evidence on the ground, however, suggests continuity rather than change in international financial institution policies in Egypt and Tunisia, notwithstanding the emergence of a powerful new player-the European Bank for Reconstruction and Development. In the long term, new electoral realities and hardening public opposition in both countries seem likely to force a fundamentally different relationship between regional governments and the major international financial institutions than existed before 2011.

HYDROBIOLOGICAL CHARACTERISTICS OF THE COASTAL LAGOONS AT HUGH TAYLOR BIRCH STATE RECREATION AREA, FORT LAUDERDALE, FLORIDA: A HISTORICAL PERSPECTIVE.

USGS Publications Warehouse

Brock, Robert J.

1987-01-01

The author presents initial results of an ongoing study of Southeast Florida coastal lagoon lakes. Objectives include presenting environmental conditions within and adjacent to the lagoons under a variety of hydrologic conditions and to determine water-quality changes in ground water and surface water and how these changes in water quality affect lagoonal biological communities within the lagoons.

Parasite communities of the neotropical cormorant Phalacrocorax brasilianus (Gmelin) (Aves, Phalacrocoracidae) from two coastal lagoons in Guerrero state, Mexico.

PubMed

Violante-González, Juan; Monks, Scott; Gil-Guerrero, Salvador; Rojas-Herrera, Agustín; Flores-Garza, Rafael; Larumbe-Morán, Edvino

2011-11-01

The parasite community structure of the neotropical cormorant, Phalacrocorax brasilianus, from two lagoons (Coyuca and Tres Palos) from Guerrero state, México, was examined. Fourteen species of adult helminths (6,391 individuals) from 48 cormorants were identified: 9 digeneans, 1 acanthocephalan, 1 cestode, and 3 nematodes. A total of 11 species were collected in Coyuca Lagoon and 12 in Tres Palos Lagoon. Nine species co-occurred in cormorants of both lagoons but, with the exception of Contracaecum multipapillatum and Drepanocephalus olivaceus, species were not equally common in both lagoons. The prevalence values of six species of helminth and the mean abundance of four species varied significantly between lagoons, and C. multipapillatum was numerically dominant in both lagoons. The qualitative similarity between the two communities at the component level was 64%. All cormorants examined were infected, and parasite species richness was 3-5 in Coyuca and 4-9 in Tres Palos lagoon. The results indicate that both communities presented a similar structure at the component level, probably because the cormorants of both lagoons feed on the same species of fish and thus acquire almost the same species of parasites. Differences observed at the infracommunity level were attributed to variations in the degree of dominance of the particular species.

Flushing of a polluted lagoon in Canc'un, using a SIBEO wave-driven seawater pump

NASA Astrophysics Data System (ADS)

Czitrom, Steven; Carbajal, Noel

2006-11-01

The coastal lagoon which adorns the seaside resort at Canc'un, Mexico, is heavily polluted as a result of decades of intense tourist activity development and overwhelmed inadequate planning. The natural flushing time of the lagoon, estimated at 2 to 4 years, is insufficient to cope with the waste that is being dumped and a thick layer of organic matter has accumulated on the lagoon bed. Appropriate legal and sewage treatment measures are imperative to curb further dumping and thus attack the root cause of the problem. This aside, however, the existing situation requires additional technical solutions to restore the ecosystem to a less altered state. A wave and tide driven seawater pump, invented and developed at the National University of Mexico, has been proposed to flush the lagoon with an average 0.2 m^3/s of clean and oxygen rich seawater from the neighboring ocean. This flow would reduce the residence time of the lagoon to around 6 months, promoting long term recovery of the ecosystem. The effect and distribution of the pumped water is being studied using a wind and tide driven 3D numerical model of the lagoon hydrodynamics. Some results from this study are presented here.

Inhibition of microbial metabolism in anaerobic lagoons by selected sulfonamides, tetracyclines, lincomycin, and tylosin tartrate

USGS Publications Warehouse

Loftin, Keith A.; Henny, Cynthia; Adams, Craig D.; Surampali, Rao; Mormile, Melanie R.

2005-01-01

Antibiotics are used to maintain healthy livestock and to promote weight gain in concentrated animal feed operations. Antibiotics rarely are metabolized completely by livestock and, thus, are often present in livestock waste and in waste-treatment lagoons. The introduction of antibiotics into anaerobic lagoons commonly used for swine waste treatment has the potential for negative impacts on lagoon performance, which relies on a consortium of microbes ranging from fermentative microorganisms to methanogens. To address this concern, the effects of eight common veterinary antibiotics on anaerobic activity were studied. Anaerobic microcosms, prepared from freshly collected lagoon slurries, were amended with individual antibiotics at 10 mg/L for the initial screening study and at 1, 5, and 25 mg/L for the dose-response study. Monitored metabolic indicators included hydrogen, methane, and volatile fatty acid concentrations as well as chemical oxygen demand. The selected antibiotics significantly inhibited methane production relative to unamended controls, thus indicating that antibiotics at concentrations commonly found in swine lagoons can negatively impact anaerobic metabolism. Additionally, historical antibiotic usage seems to be a potential factor in affecting methane production. Specifically, less inhibition of methane production was noted in samples taken from the lagoon with a history of multiple-antibiotic use.

Inhibition of microbial metabolism in anaerobic lagoons by selected sulfonamides, tetracyclines, lincomycin, and tylosin tartrate.

PubMed

Loftin, Keith A; Henny, Cynthia; Adams, Craig D; Surampali, Rao; Mormile, Melanie R

2005-04-01

Antibiotics are used to maintain healthy livestock and to promote weight gain in concentrated animal feed operations. Antibiotics rarely are metabolized completely by livestock and, thus, are often present in livestock waste and in waste-treatment lagoons. The introduction of antibiotics into anaerobic lagoons commonly used for swine waste treatment has the potential for negative impacts on lagoon performance, which relies on a consortium of microbes ranging from fermentative microorganisms to methanogens. To address this concern, the effects of eight common veterinary antibiotics on anaerobic activity were studied. Anaerobic microcosms, prepared from freshly collected lagoon slurries, were amended with individual antibiotics at 10 mg/L for the initial screening study and at 1, 5, and 25 mg/L for the dose-response study. Monitored metabolic indicators included hydrogen, methane, and volatile fatty acid concentrations as well as chemical oxygen demand. The selected antibiotics significantly inhibited methane production relative to unamended controls, thus indicating that antibiotics at concentrations commonly found in swine lagoons can negatively impact anaerobic metabolism. Additionally, historical antibiotic usage seems to be a potential factor in affecting methane production. Specifically, less inhibition of methane production was noted in samples taken from the lagoon with a history of multiple-antibiotic use.

Sludge reduction and water quality improvement in anaerobic lagoons through influent pre-treatment

USDA-ARS?s Scientific Manuscript database

Confined swine production generates large volumes of wastewater typically stored and treated in anaerobic lagoons. These lagoons may require cleanup and closure measures in the future. In practice, liquid and sludge need to be removed by pumping, usually at great expense of energy, and land applied ...

Developing a model for the mercury cycle in the Marano-Grado Lagoon (Italy)

EPA Science Inventory

The Marano-Grado Lagoon is a wetland system of about 160 km2 located in the Northern Adriatic Sea (Italy) between the Tagliamento and the Isonzo River mouths. The lagoon morphology and biogeochemistry are primarily controlled by the exchange with the Adriatic Sea and, to a lesser...

The role of connectivity and hydrodynamic conditions in the configuration of ichthyoplankton assemblages in coastal lagoons

NASA Astrophysics Data System (ADS)

Pérez-Ruzafa, Angel; Quispe, Jhoni I.; Umgiesser, Georg; Ghezzo, Michol; De Pascalis, Francesca; Marcos, Concepción

2014-05-01

Fish assemblages in coastal lagoons are constituted by species with different gilds and life stories including estuarine residents but also a high percentage of marine stragglers and marine migrants. Previous studies showed that different ichthyoplancton assemblages can be identified inside a lagoon, depending on hydrological conditions, but at the same time a high spatial and temporal variability haven observed. The proposed models to explain lagoon assemblages configuration based on probabilities of colonization from the open sea involves an important stochastic component and introduces some randomness that could lead to that high spatial and temporal variability at short and long-term scales. In this work we analyze the relationship between ichthyoplankton assemblages in the Mar Menor lagoon and the adjacent open sea in the framework of the hydrodynamics of the lagoon and connectivity between sampling stations using hydrodynamic models. The results, show a complex interaction between the different factors that lead to a highly variable system with high accumulated richness and diversity of species, and a large proportion of occasional visitors and stragglers suggesting that the mechanisms of competitive lottery can play an important role in the maintenance of communities of coastal lagoons , where environmental variability occurs in a system with strong differences in colonization rates and connectivity, not only with the open sea, but also between locations within the lagoon.

CISOCUR - Hydrodynamic circulation in the Curonian Lagoon inferred through stable isotope measurements and numerical modelling

NASA Astrophysics Data System (ADS)

Umgiesser, Georg; Razinkovas-Baziukas, Arturas; Barisevičiūtė, Ruta; Baziukė, Dalia; Ertürk, Ali; Gasiūnaitė, Jovita; Gulbinskas, Saulius; Lubienė, Irma; Maračkinaite, Jurgita; Petkuvienė, Jolita; Pilkaitytė, Renata; Ruginis, Tomas; Zemlys, Petras; Žilius, Mindaugas

2013-04-01

The spatial pattern of the hydrodynamic circulation of the Curonian lagoon, the largest European coastal lagoon, is still little understood. In absence of automatic current registration data all the existing models relied mostly on such data as water levels leaving high level of uncertainty. Here we present CISOCUR, a new project financed by the European Social Fund under the Global Grant measure. The project applies a new methodology that uses the carbon stable isotope (SI) ratio of C12 and C13 that characterize different water sources entering the lagoon and may be altered by internal kinetic processes. Through the tracing of these isotope ratios different water masses can be identified. This gives the possibility to validate several hypotheses of water circulation and validate hydrodynamic models. In particular it will be possible to 1) trace water masses entering the lagoon through the Nemunas and the Klaipeda strait; 2) test the hypothesis of sediment transport mechanisms inside the lagoon; 3) evaluate the importance of physical forcing on the lagoon circulation. The use of a hydrodynamic finite element model, coupled with the SI method, will allow for a realistic description of the transport processes inside the Curonian lagoon. So the main research goal is to apply the stable isotope tracers and a finite element model to determine the circulation patterns in the Curonian lagoon. Overall, the project will develop according to 4 main phases: 1) A pilot study to measure the isotope composition of different carbon compounds (dissolved and suspended) in different water bodies that feed water into the central lagoon. Through this pilot study the optimal study sites for the seasonal campaign will be identified as well. 2) Seasonal field campaigns in the monitoring stations identified in phase 1 to measure the carbon isotope ratio. 3) Development of a model that describes the kinetics of carbon isotopes and its transformation. 4) Application of a hydrodynamic model

Metazoan parasites of fishes from the Celestun coastal lagoon, Yucatan, Mexico.

PubMed

Sosa-Medina, Trinidad; Vidal-Martínez, Víctor M; Aguirre-Macedo, M Leopoldina

2015-08-31

The aims of this study were to produce a checklist of the metazoan parasites of fishes from the Celestun coastal lagoon and to determine the degree of faunal similarity among the fishes based on the metazoan parasites they share. A checklist was prepared including all available records (1996-2014) of parasites of marine, brackish water and freshwater fishes of the area. All of these data were included in a presence/absence database and used to determine similarity via Jaccard's index. The results indicate the presence of 62 metazoan parasite species infecting 22 fish species. The number of metazoan parasite species found in the fishes from the Celestún lagoon is apparently the highest reported worldwide for a tropical coastal lagoon. The parasites included 12 species of adult digeneans, 27 digeneans in the metacercarial stage, 6 monogeneans, 3 metacestodes, 9 nematodes, 2 acanthocephalans, 2 crustaceans and 1 annelid. Forty parasite species were autogenic and 23 were allogenic and 1 unknown. The overall similarity among all of the species of fish with respect to the metazoan parasites they share was low (0.08 ± 0.12), with few similarity values above 0.4 being obtained. This low similarity was due primarily to the presence of suites of parasites exclusive to specific species of fish. The autogenic component of the parasite fauna (40 species) dominated the allogenic component (21 species). The most likely explanation for the large number of fish parasites found at Celestún is the good environmental condition of the lagoon, which allows the completion of parasite life cycles and free circulation of euryhaline fishes from the marine environment bringing marine parasites into the lagoon.

Méthodologie de l'extraction des hydrocarbures aromatiques polycycliques. Application à des sédiments de la lagune de Bizerte (Tunisie)Methodology of extraction of polycyclic aromatic hydrocarbons. Application to sediment from the Bizerte Lagoon (Tunisia)

NASA Astrophysics Data System (ADS)

Mzoughi, Nadia; Hellal, Fayçal; Dachraoui, Mohamed; Villeneuve, Jean-Pierre; Cattini, Chantal; de Mora, Stephen J.; El Abed, Amor

2002-09-01

The marine environment is very complex, with several important chemical, biological, and sedimentological interactions. Sediments constitute a reservoir for numerous pollutants, including polycyclic aromatic hydrocarbons (PAHs). PAHs are known by their mutagenic and/or carcinogenic effect. This study evaluates contamination levels in Bizerte Lagoon with respect to PAHs. The extraction efficiency of PAHs from sediment has been evaluated using Soxhlet or ultrasonic procedures, based on the recovery of an internal standard (9,10-dihydroanthracene). Several PAHs were found, including sixteen that are reported in the priority list of pollutants of the US Environmental Protection Agency (EPA). PAHs analysis was carried out by GC-FID and GC-MS for 16 samples sampled in two seasons: summer and winter. Results permit an assessment of PAHs pollution in the Bizerte Lagoon. To cite this article: N. Mzoughi et al., C. R. Geoscience 334 (2002) 893-901.

Sediment characteristics and water quality in the two hyper-saline lagoons along the Red Sea coast of Saudi Arabia

NASA Astrophysics Data System (ADS)

Rasul, Najeeb; Al-Farawati, Radwan; Al-Harbi, Omer; Naser Qutub, Abdul

2013-04-01

The two hyper-saline Shoaiba lagoons, Khawr ash Shaibah al Masdudah (northern lagoon) and Khawr ash Shaibah al Maftuhah (southern lagoon) have a unique environmental set-up because no rivers or wadis flow into the lagoons and therefore detrital material to the lagoons is lacking and most of the sediments are indigenous carbonates. The biogenic material is mostly derived from coral debris, coralline algae and molluscs abundant in gravel and sand size fractions. The evaporite deposits from the adjoining sabkhas are transported to the lagoon during tidal cycles. Carbonate is abundant in the form of aragonite and High Mg-calcite indicating carbonate to be recent and formed under shallow water conditions. In general, the sediments are the result of the mechanical breakdown of molluscs and coral reefs by either human activity or by coral boring marine organisms and physical processes such as tidal and wind generated currents. Strong currents dominate only the deeper part at the entrance of the lagoons that causes the winnowing of the finer sediments, and its transportation during flooding and ebbing. Shallow depths averaging 3 m, wind and tidal stirring are the main forces preventing the lagoons from developing stratification resulting in a well-mixed body of water. The shallow depth of the lagoons keep the turbidity levels higher, whereas salinity as high as 52 ‰ and water temperature as high as 38 °C helps in the formation of halite at the periphery. The cyclical inundation of sabkhas by a thin sheet of water during tidal cycles is important in understanding the ecological consequence. Mangrove stands in the lagoons act as a source of nutrients to the flora and fauna inhabiting the lagoons. The configurations of the mouth of the lagoons influence the tidal currents, including the sediment and water movement. The tidal current is enhanced as it enters the lagoons, in response to the funneling effect caused by the narrow channel. The current diffuses as the entrance

Production of Ne Auger electrons by Ne/+/ bombardment of Mg and Al surfaces

NASA Technical Reports Server (NTRS)

Ferrante, J.; Pepper, S. V.

1976-01-01

A description is given of experiments which provide evidence for the production of an inner shell vacancy in the Ne by the asymmetric Ne-Mg and Ne-Al collision. In addition, autoionization states of neutral Ne have been observed. These states are to be distinguished from the more usual case in Auger electron spectroscopy of de-excitation of an ion with a core vacancy. The experiments involved the bombardment of Mg and Al surfaces with Ne(+) ions. A LEED-Auger system equipped with an ion gun and a four-grid retarding potential analyzer operated in the usual dN(E)/dE mode was used.

Into the Depths of the Lagoon Nebula

NASA Image and Video Library

2011-09-16

Swirling dust clouds and bright newborn stars dominate the view in this image of the Lagoon nebula from NASA Spitzer Space Telescope. The nebula lies in the general direction of the center of our galaxy in the constellation Sagittarius.

Prevalence, Genotype Distribution and Risk Factors for Cervical Human Papillomavirus Infection in the Grand Tunis Region, Tunisia.

PubMed

Ardhaoui, Monia; Ennaifer, Emna; Letaief, Hajer; Salsabil, Rejaibi; Lassili, Thalja; Chahed, Karim; Bougatef, Souha; Bahrini, Asma; El Fehri, Emna; Ouerhani, Kaouther; Paez Jimenez, Adela; Guizani, Ikram; Boubaker, Med Samir; Ben Alaya, Nissaf Bouafif Ép

2016-01-01

Implementation of Human Papillomavirus (HPV) vaccination should be considered a key cervical cancer prevention strategy in Tunisia, where Pap smear screening is not efficient. This study aims to estimate the prevalence and to identify risk factors associated with HPV infection among women from Grand Tunis, Tunisia. We conducted a cross-sectional study, between December 2012 and May 2013. Eligible women for this study were those aged 18-65 years, sexually active, who sought medical attention at their primary health care centre or clinic in Grand Tunis, Tunisia and who gave written consent. A liquid-based Pap smear sample was obtained from all women using a cervical brush. Only women with betaglobin positive test were further analysed for HPV detection and typing. A nested-PCR of the L1 region was performed followed by reverse line blot hybridization to facilitate the specific detection of 31 HPV genotypes. Multiple logistic regression modeling was used for the analysis of associations between variables with some considered possible confounders after checking for interactions. A total of 391 women were enrolled in this study and 325 out of the 391 cervical samples were positive for the betaglobin test. Overall HPV prevalence was 13.2% [9.8%-17.5%], with the following most prevalent HPV genotypes: HPV6 (40%), HPV40 (14%), HPV16 (12%), HPV52 (9%), HPV31 and HPV59 (7%), followed by HPV68 (4%). Mean age of HPV positive women was 40.7±0.92 years. Independently associated risk factors of HPV infection were smoking (OR:2.8 [0.8-9.6]), low income (OR:9.6 [1.4-63.4), bad housing type (OR:2.5 [1-6.8]), partner with multiple sexual relationship (OR:4.5 [0.9-22.9]) and single women (widowed, divorced, separated, never married) (OR:6.9 [1.1-42.2]). This study provides the first national-based estimate of HPV prevalence in Tunisia. Our findings contribute to the evidence on the current burden of HPV infection, the critical role of sexual behaviour and socioeconomic status and

Tidal dynamics in a changing lagoon: Flooding or not flooding the marginal regions

NASA Astrophysics Data System (ADS)

Lopes, Carina L.; Dias, João M.

2015-12-01

Coastal lagoons are low-lying systems under permanent changes motivated by natural and anthropogenic factors. Ria de Aveiro is such an example with its margins currently threatened by the advance of the lagoonal waters recorded during the last decades. This work aims to study the tidal modifications found between 1987 and 2012 in this lagoon, motivated by the main channels deepening which induce higher inland tidal levels. Additionally it aims to study the impact that protective walls designed to protect the margins against flooding may have in those modifications under sea level rise predictions. The hydrodynamic model ELCIRC previously calibrated for Ria de Aveiro was used and tidal asymmetry, tidal ellipses and residual currents were analyzed for different scenarios, considering the mean sea level rise predicted for 2100 and the implementation of probable flood protection walls. Results evidenced that lagoon dominance remained unchanged between 1987 and 2012, but distortion decreased/increased in the deeper/shallower channels. The same trend was found under mean sea level rise conditions. Tidal currents increased over this period inducing an amplification of the water properties exchange within the lagoon, which will be stronger under mean sea level rise conditions. The deviations between scenarios with or without flood protection walls can achieve 60% for the tidal distortion and residual currents and 20% for the tidal currents, highlighting that tidal properties are extremely sensitive to the lagoon geometry. In summary, the development of numerical modelling applications dedicated to study the influence of mean sea level rise on coastal low-lying systems subjected to human influence should include structural measures designed for flood defence in order to accurately predict changes in the local tidal properties.

A Trophic Model of a Sandy Barrier Lagoon at Chiku in Southwestern Taiwan

NASA Astrophysics Data System (ADS)

Lin, H.-J.; Shao, K.-T.; Kuo, S.-R.; Hsieh, H.-L.; Wong, S.-L.; Chen, I.-M.; Lo, W.-T.; Hung, J.-J.

1999-05-01

Using the ECOPATH 3.0 software system, a balanced trophic model of a sandy barrier lagoon with intensive fishery activities at Chiku in tropical Taiwan was constructed. The lagoon model comprised 13 compartments. Trophic levels of the compartments varied from 1·0 for primary producers and detritus to 3·6 for piscivorous fish. Hanging-cultured oysters accounted for 39% of the harvestable fishery biomass and were the most important fishery species. The most prominent group in terms of biomass and energy flow in the lagoon was herbivorous zooplankton. Manipulations of the biomass of herbivorous zooplankton would have a marked impact on most compartments. Both total system throughput and fishery yield per unit area were high when compared to other reported marine ecosystems. This appears mainly due to high planktonic primary production, which is probably promoted by enriched river discharges draining mangroves and aquaculture ponds. Consequently, more than half of the total system throughput originates from primary producers in the lagoon. Although half of the primary production was not immediately used by upper trophic levels and flowed into the detrital pool, most of the detritus was directly consumed, passed up the food web and was exported to the fishery. Thus only a small proportion of energy was recycled through detritus pathways. This mechanism produces short pathways with high trophic efficiencies at higher trophic levels. The high fishery yield in the lagoon is due to high primary production and short pathways. This is the first model of a tropical sandy barrier lagoon with intensive fishery activities and thus may serve as a basis for future comparisons and ecosystem management.

[Role of Toscana virus in meningo-encephalitis in Tunisia].

PubMed

Bahri, O; Fazaa, O; Ben Alaya-Bouafif, N; Bouloy, M; Triki, H; Bouattour, A

2011-12-01

To detect the presence of Toscana virus (TOSV) circulation in Tunisia and to study its role in viral meningo-encephalitis. A total of 315 (167 sera and 178 cerobrospinal fluid [CSF]) samples was investigated. These samples are colleted from Tunisian patients with neurological diseases during the period between January 2003 and December 2009. All samples were tested negative for enterovirus, Herpes Simplex virus and West Nile virus. Detection for IgM and IgG specific to TOSV was done by ELISA tests. Specific IgM for TOSV were detected in 10 % of patients with neurological diseases (31 cases). These recent infections were distributed throughout the study period and predominated during summer and automn. Patients were originated, in the majority from the coastal region. IgG were isolated in 22 cases (7 %) corresponding to previous infection. This is the first report of TOSV circulating in Tunisia and its frequent implication in neurological diseases. These results incited to include TOSV as one of the viral etiologies to target in the diagnosis of viral meningitis and encephalitis in the country. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

Biodegradation of hexadecane using sediments from rivers and lagoons of the Southern Gulf of Mexico.

PubMed

García-Cruz, N Ulises; Sánchez-Avila, Juan I; Valdés-Lozano, David; Gold-Bouchot, Gerardo; Aguirre-Macedo, Leopoldina

2018-03-01

The Southern Gulf of Mexico is an area highly impacted by crude oil extraction, refining activities and the presence of natural petroleum seepage. Oceanic currents in the Gulf of Mexico continually facilitate the transport of hydrocarbons to lagoons and rivers. This research evaluated hexadecane (HXD) degradation in marine sediment samples from lagoons and rivers that are fed by the Southern Gulf of Mexico, specifically six samples from rivers, three samples from lagoons, and one sample from a marine outfall. The highest rates of biodegradation were observed in sediments from the mouths of the Gonzalez River and the Champotón Lagoon. The lowest consumption rate was found in sediment from the mouth of the Coatzacoalcos River. With regards to the Ostión Lagoon and the Grijalva River, there was a low rate of consumption, but a high efficiency of degradation which took place at the end of the experiments. No correlation was found between the consumption rate and the environmental physicochemical parameters. Copyright © 2018 Elsevier Ltd. All rights reserved.

Meiobenthic communities in permanently open estuaries and open/closed coastal lagoons of Uruguay (Atlantic coast of South America)

NASA Astrophysics Data System (ADS)

Kandratavicius, N.; Muniz, P.; Venturini, N.; Giménez, L.

2015-09-01

This study aimed to determine if estuarine meiofaunal communities of Uruguay (South America) vary between permanently open estuaries and open/closed coastal lagoons, or if they respond to the sediment composition. In Uruguay, estuaries and coastal lagoons vary in the degree of connectivity to the sea and in the sediment composition; sediments in estuaries are characterized by fine-medium sands but sediments vary from lagoon to lagoon (either fine-medium or coarse sand). Taxa richness (total = 16) showed less temporal variability in lagoons than in estuaries, due to patterns of presence/absence of the less abundant taxa. However, no major response to habitat was found in the most abundant groups: polychaetes (6% of total fauna) were on average 5% more abundant in lagoons than in estuaries. Some level of zonation, within estuaries and lagoons, was found in the most abundant groups, nematodes (63% of total fauna) and copepods (15%) in response to medium and fine sands. In addition, sediment type modulated seasonal patterns in the frequency of presence/absence in ostracods, polychaetes and oligochaetes. For instance, in polychaetes and ostracods the increase in the frequency of absences, occurring from summer to winter, was stronger in lagoons and estuaries dominated by fine sands. The lagoon habitat appears to ameliorate the effects of unfavourable (winter) conditions in less abundant meiofaunal taxa. In summary, sediment fractions explain spatial patterns in the average abundance of organisms (e.g. nematodes) as well as the seasonal changes in frequency of presence/absence (e.g. polychaetes).

Spatio-temporal Genetic Structuring of Leishmania major in Tunisia by Microsatellite Analysis

PubMed Central

Harrabi, Myriam; Bettaieb, Jihène; Ghawar, Wissem; Toumi, Amine; Zaâtour, Amor; Yazidi, Rihab; Chaâbane, Sana; Chalghaf, Bilel; Hide, Mallorie; Bañuls, Anne-Laure; Ben Salah, Afif

2015-01-01

In Tunisia, cases of zoonotic cutaneous leishmaniasis caused by Leishmania major are increasing and spreading from the south-west to new areas in the center. To improve the current knowledge on L. major evolution and population dynamics, we performed multi-locus microsatellite typing of human isolates from Tunisian governorates where the disease is endemic (Gafsa, Kairouan and Sidi Bouzid governorates) and collected during two periods: 1991–1992 and 2008–2012. Analysis (F-statistics and Bayesian model-based approach) of the genotyping results of isolates collected in Sidi Bouzid in 1991–1992 and 2008–2012 shows that, over two decades, in the same area, Leishmania parasites evolved by generating genetically differentiated populations. The genetic patterns of 2008–2012 isolates from the three governorates indicate that L. major populations did not spread gradually from the south to the center of Tunisia, according to a geographical gradient, suggesting that human activities might be the source of the disease expansion. The genotype analysis also suggests previous (Bayesian model-based approach) and current (F-statistics) flows of genotypes between governorates and districts. Human activities as well as reservoir dynamics and the effects of environmental changes could explain how the disease progresses. This study provides new insights into the evolution and spread of L. major in Tunisia that might improve our understanding of the parasite flow between geographically and temporally distinct populations. PMID:26302440

Tunisia Renewable Energy Project systems description report

NASA Technical Reports Server (NTRS)

Scudder, L. R.; Martz, J. E.; Ratajczak, A. F.

1986-01-01

In 1979, the Agency for International Development (AID) initiated a renewable energy project with the Government of Tunisia to develop an institutional capability to plan and institute renewable energy technologies in a rural area. The specific objective of the district energy applications subproject was to demonstrate solar and wind energy systems in a rural village setting. The NASA Lewis Research Center was asked by the AID Near East Bureau to manage and implement this subproject. This report describes the project and gives detailed desciptions of the various systems.

Spatial variation of acid-volatile sulfide and simultaneously extracted metals in Egyptian Mediterranean Sea lagoon sediments.

PubMed

Younis, Alaa M; El-Zokm, Gehan M; Okbah, Mohamed A

2014-06-01

In risk assessment of aquatic sediments, the immobilizing effect of acid-volatile sulfide (AVS) on trace metals is a principal control on availability and associated toxicity of metals to aquatic biota, which reduces metal bioavailability and toxicity by binding and immobilizing metals as insoluble sulfides. Spatial variation pattern of AVS, simultaneously extracted metals (SEM), and sediment characteristics were studied for the first time in surface sediment samples (0-20 cm) from 43 locations in Egyptian northern delta lagoons (Manzalah, Burullus, and Maryut) as predictors of the bioavailability of some divalent metals (Cu, Zn, Cd, Pb, and Ni) in sediments as well as indicators of metal toxicity in anaerobic sediments. The results indicated that the ∑SEM (Cu + Zn + Cd + Pb + Ni) values in sediments of lagoon Burullus had higher concentrations than those of Maryut and Manzalah. In contrast, AVS concentrations were considerably higher in lagoons Manzalah and Maryut and seemed to be consistent with the increase in organic matter than lagoon Burullus. Generally, the average concentrations of the SEM in all lagoons were in the order of Zn > Cu > Ni > Pb > Cd. The ratios of ∑SEM/AVS were less than 1 at all the sampling stations except at one station in lagoon Maryut as well as four stations located in lagoon Burullus (∑SEM/AVS > 1), which suggests that the metals have toxicity potential in these sediments. Therefore, SEM concentrations probably are better indicators of the metal bioavailability in sediments than the conventional total metal concentrations.

Vadose Zone Monitoring of Dairy Green Water Lagoons using Soil Solution Samplers.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brainard, James R.; Coplen, Amy K

2005-11-01

Over the last decade, dairy farms in New Mexico have become an important component to the economy of many rural ranching and farming communities. Dairy operations are water intensive and use groundwater that otherwise would be used for irrigation purposes. Most dairies reuse their process/green water three times and utilize lined lagoons for temporary storage of green water. Leakage of water from lagoons can pose a risk to groundwater quality. Groundwater resource protection infrastructures at dairies are regulated by the New Mexico Environment Department which currently relies on monitoring wells installed in the saturated zone for detecting leakage of wastemore » water lagoon liners. Here we present a proposal to monitor the unsaturated zone beneath the lagoons with soil water solution samplers to provide early detection of leaking liners. Early detection of leaking liners along with rapid repair can minimize contamination of aquifers and reduce dairy liability for aquifer remediation. Additionally, acceptance of vadose zone monitoring as a NMED requirement over saturated zone monitoring would very likely significantly reduce dairy startup and expansion costs. Acknowledgment Funding for this project was provided by the Sandia National Laboratories Small Business Assistance Program« less

Reprint of "Echinococcus granulosus sensu stricto (s.s.) from the critically endangered antelope Addax nasomaculatus in Tunisia".

PubMed

Boufana, Belgees; Saïd, Yousra; Dhibi, Mokhtar; Craig, Philip S; Lahmar, Samia

2017-01-01

Echinococcus granulosus sensu lato (s.l.) is a zoonotic disease highly endemic in Tunisia. Canids including stray and semi-stray dogs, jackals and foxes are known as definitive hosts and a wide range of ungulates have been shown to harbour the metacestode hydatid stage and may serve as intermediate hosts. Fertile hydatid cysts of Echinococcus equinus and E. granulosus sensu stricto (s.s.) were recently molecularly identified for the first time from Tunisian donkeys. E. granulosus (s.s.) was also identified from wild boars in Tunisia. Here we report the confirmation of hydatid cysts caused by E. granulosus (s.s.) in the critically endangered antelope, Addax nasomaculatus in Tunisia. DNA-based molecular analysis revealed that A. nasomaculatus was infected with E. granulosus (s.s.) which had a 100% identity with the main globally distributed E. granulosus (s.s.) (EgTu01) haplotype. Cysts of Taenia hydatigena (n=33) were also observed on the liver and in the body cavity. Due to their endangered status and their relatively small numbers, it is unlikely that hydatid infection of A. nasomaculatus will form a major contribution to the epidemiology and transmission of E. granulosus in Tunisia, but infection may result in pathology, morbidity and early mortality, and may still play a role in the perpetuation of the parasite in wildlife cycles. Copyright © 2015 Elsevier B.V. All rights reserved.

Optical researches for cyanobacteria bloom monitoring in Curonian Lagoon

NASA Astrophysics Data System (ADS)

Shirshin, Evgeny A.; Budylin, Gleb B.; Yakimov, Boris P.; Voloshina, Olga V.; Karabashev, Genrik S.; Evdoshenko, Marina A.; Fadeev, Victor V.

2016-04-01

Cyanobacteria bloom is a great ecological problem of Curonian Lagoon and Baltic Sea. The development of novel methods for the on-line control of cyanobacteria concentration and, moreover, for prediction of bloom spreading is of interest for monitoring the state of ecosystem. Here, we report the results of the joint application of hyperspectral measurements and remote sensing of Curonian Lagoon in July 2015 aimed at the assessment of cyanobacteria communities. We show that hyperspectral data allow on-line detection and qualitative estimation of cyanobacteria concentration, while the remote sensing data indicate the possibility of cyanobacteria bloom detection using the spectral features of upwelling irradiation.

Late Holocene sedimentation in a high Arctic coastal setting: Simpson Lagoon and Colville Delta, Alaska

NASA Astrophysics Data System (ADS)

Hanna, Andrea J. M.; Allison, Mead A.; Bianchi, Thomas S.; Marcantonio, Franco; Goff, John A.

2014-02-01

Arctic coastal environments near major river outfalls, like Simpson Lagoon, Alaska and the adjacent Colville River Delta, potentially contain high-resolution sediment records useful in elucidating late Holocene Arctic sediment transport pathways and coupled terrestrial-ocean evidence of paleoclimate variability. This study utilizes a multi-tracer geochronology approach (137Cs, 239,240Pu, and 14C) tailored for high-latitude environments to determine the age models for cores collected from Simpson Lagoon, and to date seismic boundaries in shallow acoustic reflection data (CHIRP) to examine late Holocene infill patterns. Modern (~100 y) sediment accumulation rates range from <0.02 to 0.46±0.04 cm y-1, with a primary depocenter in western Simpson Lagoon adjacent to the Colville Delta and a secondary depocenter in eastern Simpson Lagoon. CHIRP reflectors, age-constrained by 14C analysis, reveal rapid late Holocene (0-3500 y BP) transgression consistent with high modern shoreline retreat rates. The western depocenter contains >5 m of late Holocene interbedded sediments, likely derived primarily from the Colville River, with onset of accumulation occurring prior to ~3500 y BP. A paleo-high in central Simpson Lagoon, separating the two depocenters, was subaerially exposed prior to ~600 y BP. The millimeters-per-year sedimentation rates across the lagoon, coupled with the undisturbed, interbedded sediment record, indicate that these settings hold great potential to develop new Arctic paleoenvironmental records.

Acid Tar Lagoons: Management and Recovery

NASA Astrophysics Data System (ADS)

Bohers, Anna; Hroncová, Emília; Ladomerský, Juraj

2017-04-01

This contribution presents the issue with possibility of definitive removal of dangerous environmental burden in Slovakia - serious historical problem of two acid tar lagoons. In relation to their removal, no technology has been found so far - technologically and economically suitable, what caused problems with its management. Locality Predajná is well known in Slovakia by its character of contrasts: it is situated in the picturesque landscape of National Park buffer zone of Nízke Tatry, on the other site it is contaminated by 229 211m3 of acid tar with its characteristics of toxicity, carcinogenicity, teratogenicity, mutagenicity and toxicity especially for animals and plants. Acid tar in two landfills with depth of 1m in case of the first lagoon and 9,5m in case of the second lagoon is a waste product derived from operation of Petrochema Dubová - refinery and petrochemical plant whose activity was to process the crude oil through processes of sulfonation and adsorption technology for producing lubricating and special oils, synthetic detergents and special white oils for cosmetic and medical purposes. A part of acid tar was incinerated in two incineration plats. Concentration of SO2 in combustion gases was too high and it was not possible to decrease it under the value of 2000 mg.mn-3 [LADOMERSKÝ, J. - SAMEŠOVÁ, D.: Reduction in sulfur dioxide emissions waste gases of incineration plant. Acta facultatis ecologiae. 1999, p. 217-223]. That is why it was necessary to put them out of operation. Later, because of public opposition it was not possible to build a new incineration plat corresponding to the state of the art. Even though actual Slovak and European legislative for protection of environment against such impacts, neither of tried methods - bio or non-biologic treatment methods - was proved as suitable for processing or for recovery in the reason of different factors admission: i.e. strong aggressivity, difficulty with handling because of its sludgy and

Assessment of temporal and spatial water quality in international Gomishan Lagoon, Iran, using multivariate analysis.

PubMed

Basatnia, Nabee; Hossein, Seyed Abbas; Rodrigo-Comino, Jesús; Khaledian, Yones; Brevik, Eric C; Aitkenhead-Peterson, Jacqueline; Natesan, Usha

2018-04-29

Coastal lagoon ecosystems are vulnerable to eutrophication, which leads to the accumulation of nutrients from the surrounding watershed over the long term. However, there is a lack of information about methods that could accurate quantify this problem in rapidly developed countries. Therefore, various statistical methods such as cluster analysis (CA), principal component analysis (PCA), partial least square (PLS), principal component regression (PCR), and ordinary least squares regression (OLS) were used in this study to estimate total organic matter content in sediments (TOM) using other parameters such as temperature, dissolved oxygen (DO), pH, electrical conductivity (EC), nitrite (NO 2 ), nitrate (NO 3 ), biological oxygen demand (BOD), phosphate (PO 4 ), total phosphorus (TP), salinity, and water depth along a 3-km transect in the Gomishan Lagoon (Iran). Results indicated that nutrient concentration and the dissolved oxygen gradient were the most significant parameters in the lagoon water quality heterogeneity. Additionally, anoxia at the bottom of the lagoon in sediments and re-suspension of the sediments were the main factors affecting internal nutrient loading. To validate the models, R 2 , RMSECV, and RPDCV were used. The PLS model was stronger than the other models. Also, classification analysis of the Gomishan Lagoon identified two hydrological zones: (i) a North Zone characterized by higher water exchange, higher dissolved oxygen and lower salinity and nutrients, and (ii) a Central and South Zone with high residence time, higher nutrient concentrations, lower dissolved oxygen, and higher salinity. A recommendation for the management of coastal lagoons, specifically the Gomishan Lagoon, to decrease or eliminate nutrient loadings is discussed and should be transferred to policy makers, the scientific community, and local inhabitants.

Assessing hydrological effects of human interventions on coastal systems: numerical applications to the Venice Lagoon

NASA Astrophysics Data System (ADS)

Ferrarin, C.; Ghezzo, M.; Umgiesser, G.; Tagliapietra, D.; Camatti, E.; Zaggia, L.; Sarretta, A.

2012-12-01

The hydrological consequences of historical, contemporary and future human activities on a coastal system were investigated by means of numerical models. The changes in the morphology of the Lagoon of Venice during the last century result from the sedimentological response to the combined effects of human interventions on the environment and global changes. This study focuses on changes from 1927 to 2012 and includes the changes planned for the protection of the city of Venice from storm surges and exceptional tides under future sea level rise scenarios. The application of a hydrodynamic model to simulate the circulation of water masses and the transport of a passive tracer enabled the analysis of the morphodynamic effects on the lagoon circulation and the interaction with the sea. The absolute values of the exchange between the lagoon and sea increased from 1927 to 2002 (from 3900 to 4600 m3 s-1), while the daily fraction of lagoon water volume exchanged decreased. At the same time, the water renewal time shortened from 11.9 to 10.8 days. Morphological changes during the last decade induced an increase of the basin-wide water renewal time (from 10.8 to 11.3 days). In the future, Venice Lagoon will evolve to a more restricted environment due to sea level rise and periodical closure of the lagoon from the sea during flooding events. Simulated scenarios of sea level rise showed that under fall-winter conditions the water renewal time will increased considerably especially in the central part of the lagoon. Furthermore, some considerations on the impact of the hydromorphological changes on the ecological dynamics are proposed.

Middle-Upper Triassic and Middle Jurassic tetrapod track assemblages of southern Tunisia, Sahara Platform

NASA Astrophysics Data System (ADS)

Niedźwiedzki, Grzegorz; Soussi, Mohamed; Boukhalfa, Kamel; Gierliński, Gerard D.

2017-05-01

Three tetrapod track assemblages from the early-middle Mesozoic of southern Tunisia are reported. The strata exposed at the Tejra 2 clay-pit near the Medenine and Rehach site, located in the vicinity of Kirchaou, contain the first tetrapod tracks found in the Triassic of Tunisia. The Middle Jurassic (early Aalenian) dinosaur tracks are reported from the Mestaoua plain near Tataouine. In the Middle Triassic outcrop of the Tejra 2 clay-pit, tridactyl tracks of small and medium-sized dinosauromorphs, were discovered. These tracks represent the oldest evidence of dinosaur-lineage elements in the Triassic deposits of Tunisia. Similar tracks have been described from the Middle Triassic of Argentina, France and Morocco. An isolated set of the manus and pes of a quadrupedal tetrapod discovered in Late Triassic Rehach tracksite is referred to a therapsid tracemaker. The Middle Jurassic deposits of the Mestaoua plain reveal small and large tridactyl theropod dinosaur tracks (Theropoda track indet. A-C). Based on comparison with the abundant record of Triassic tetrapod ichnofossils from Europe and North America, the ichnofauna described here indicates the presence of a therapsid-dinosauromorph ichnoassociation (without typical Chirotheriidae tracks) in the Middle and Late Triassic, which sheds light on the dispersal of the Middle-Upper Triassic tetrapod ichnofaunas in this part of Gondwana. The reported Middle Jurassic ichnofauna show close similarities to dinosaur track assemblages from the Lower and Middle Jurassic of northwestern Africa, North America, Europe and also southeastern Asia. Sedimentological and lithostratigraphic data of each new tracksite have been defined on published data and new observations. Taken together, these discoveries present a tantalizing window into the evolutionary history of tetrapods from the Triassic and Jurassic of southern Tunisia. Given the limited early Mesozoic tetrapod record from the region, these discoveries are of both temporal and

Temporal coherence among tropical coastal lagoons: a search for patterns and mechanisms.

PubMed

Caliman, A; Carneiro, L S; Santangelo, J M; Guariento, R D; Pires, A P F; Suhett, A L; Quesado, L B; Scofield, V; Fonte, E S; Lopes, P M; Sanches, L F; Azevedo, F D; Marinho, C C; Bozelli, R L; Esteves, F A; Farjalla, V F

2010-10-01

Temporal coherence (i.e., the degree of synchronicity of a given variable among ecological units within a predefined space) has been shown for several limnological features among temperate lakes, allowing predictions about the structure and function of ecosystems. However, there is little evidence of temporal coherence among tropical aquatic systems, where the climatic variability among seasons is less pronounced. Here, we used data from long-term monitoring of physical, chemical and biological variables to test the degree of temporal coherence among 18 tropical coastal lagoons. The water temperature and chlorophyll-a concentration had the highest and lowest temporal coherence among the lagoons, respectively, whereas the salinity and water colour had intermediate temporal coherence. The regional climactic factors were the main factors responsible for the coherence patterns in the water temperature and water colour, whereas the landscape position and morphometric characteristics explained much of the variation of the salinity and water colour among the lagoons. These results indicate that both local (lagoon morphometry) and regional (precipitation, air temperature) factors regulate the physical and chemical conditions of coastal lagoons by adjusting the terrestrial and marine subsidies at a landscape-scale. On the other hand, the chlorophyll-a concentration appears to be primarily regulated by specific local conditions resulting in a weak temporal coherence among the ecosystems. We concluded that temporal coherence in tropical ecosystems is possible, at least for some environmental features, and should be evaluated for other tropical ecosystems. Our results also reinforce that aquatic ecosystems should be studied more broadly to accomplish a full understanding of their structure and function.

Lagoons and Reefs of New Caledonia

NASA Image and Video Library

2011-04-20

NASA image acquired May 10, 2001 In July 2008, the United Nations Educational, Scientific, and Cultural Organization (UNESCO) added 27 new areas to its list of World Heritage sites. One of those areas included the lagoons of New Caledonia. Some 1,200 kilometers (750 miles) east of Australia, this French-governed archipelago contains the world’s third-largest coral reef structure. The coral reefs enclose the waters near the islands in shallow lagoons of impressive biodiversity. On May 10, 2001, the Enhanced Thematic Mapper Plus on NASA’s Landsat 7 satellite captured this image of Île Balabio, off the northern tip of Grande Terra, New Caledonia’s main island. In this natural-color image, the islands appear in shades of green and brown—mixtures of vegetation and bare ground. The surrounding waters range in color from pale aquamarine to deep blue, and the color differences result from varying depths. Over coral reef ridges and sand bars, the water is shallowest and palest in color. Darker shades of blue characterize deeper waters. Reef-enclosed, shallow waters surround Île Balabio, and a larger, semi-enclosed lagoon appears immediately east of that island. Immediately north of Grande Terra, unenclosed, deeper waters predominate. The coral reefs around New Caledonia support an unusual diversity of species, including large numbers of predators and big fish, turtles, and the world’s third-largest dugong population. NASA image created by Jesse Allen, using Landsat data provided by the United States Geological Survey. Caption by Michon Scott. Instrument: Landsat 7 - ETM+ Credit: NASA/GSFC/Landsat NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Join us on Facebook

Stage-specific distribution models can predict eel (Anguilla anguilla) occurrence during settlement in coastal lagoons

NASA Astrophysics Data System (ADS)

Leone, C.; Zucchetta, M.; Capoccioni, F.; Gravina, M. F.; Franzoi, P.; Ciccotti, E.

2016-03-01

Eel (Anguilla anguilla) is a catadromous fish species typical of Mediterranean coastal lagoons, that currently suffers from several anthropogenic and natural impacts. These are thought to be the cause of a stock-wide decline that this panmictic species is facing, in inland and coastal waters of Europe and North Africa. The decline affects both adult phases and recruitment, i.e. glass eel arrival to coastal waters and their ascent to inland waters. Quantitative features of eel recruitment reflect a transoceanic global scale, but also depend on local environmental conditions, the latter also affecting settlement dynamics in transitional waters. There is only little information on the dynamics of these two processes in coastal lagoons, notwithstanding the paramount importance of both in sustaining local stocks abundance and their demographic structure for this typical but also economically important inhabitant of Mediterranean lagoons, habitats that constitute an important share of the eel distribution area. The present study aims, therefore, to clarify space and time dynamics of local scale recruitment and of settlement in a coastal lagoon in the Mediterranean area, also by setting up a specific methodological approach. For this purpose, data from field surveys in combination with Species Distribution Models (SDMs) have been used in order to relate distribution of eel juvenile stages to the environmental conditions within the lagoon. Specifically, models were calibrated to quantify the relationship between presence of juvenile eel and the main environmental drivers, with the aim of identifying potential habitats for eel settlement within the lagoon. Results gained by modelling suggest certain spatial and temporal colonization patterns for the juvenile eel in the Fogliano lagoon, a typical Mediterranean coastal lake. The modelling approach has therefore proved to be a useful tool for predicting habitats for eel recruitment at the local scale and settlement, because

First report of natural infection of least weasel (Mustela nivalis Linnaeus, 1776) with Leishmania major in Tunisia.

PubMed

Ghawar, Wissem; Snoussi, Mohamed Ali; Hamida, Nabil Bel Haj; Boukthir, Aïcha; Yazidi, Rihab; Chaâbane, Sana; Chemkhi, Jomâa; Zâatour, Amor; Salah, Afif Ben

2011-11-01

Zoonotic cutaneous leishmaniasis, caused by Leishmania major (L. major), is endemic in Tunisia. Several rodents have been identified as reservoir hosts of parasites. This study reports, for the first time, the natural infection with L. major zymodeme MON-25 in a specimen of least weasel: Mustela nivalis Linnaeus, 1776 (M. nivalis) collected in Sidi Bouzid. This finding justifies further research on larger samples of this animal to verify its role as a potential reservoir host for cutaneous leishmaniasis in Tunisia.

Evaluation of some heavy metal loading in the Kpeshi lagoon, Ghana

NASA Astrophysics Data System (ADS)

Fianko, Joseph R.; Laar, Cynthia; Osei, Juilet; Anim, Alfred K.; Gibrilla, Abass; Adomako, Dickson

2013-03-01

A study was carried out on the Kpeshi lagoon to evaluate the relative contributions of some heavy metals (Na, k, Ca, K, Fe, Mn, Ni, Cr, Cd, Al, Pb) on the current state of the Kpeshi lagoon. The lagoon water was sampled along with some fish samples. Water pH, electrical conductivity and total dissolved salts were measured in situ whilst Na and K were measured using flame emission spectrometry. Heavy metals (iron, manganese, nickel, aluminium, chromium, lead and cadmium) in both water and fish samples were analyzed using atomic absorption spectrometry. Measured pH values ranged between 6.60 and 7.87, a mean conductivity and total dissolved salts of 87.31 ± 19.14 μS/cm and 38.4 ± 8.43 mg/L, respectively. Nutrient and organic matter were among the frequent source of pollution in the lagoon with mean sulphate, phosphate and nitrate concentrations of 190 ± 108.84, 1.62 ± 0.49 and 0.89 ± 0.26 mg/L, respectively. Iron and aluminium in the lagoon water measured the highest concentration of 13.2 ± 3.47 and 13.6 ± 4.29 mg/L, respectively. Fish samples however revealed very high concentrations of calcium and potassium measuring 15,709 ± 75.35 and 5,949.49 ± 87.30 mg/kg, respectively. Sodium and aluminium also revealed relatively high concentrations: 3,775.70 ± 24.80 and 708.47 ± 4.95 mg/kg, respectively. Notably, sites closer to settlement community (Teshie Township, e.g. S1, S2, S3 and S4) and the hospitality industries (i.e. dotted hotels, e.g. S7) appeared to be relatively more contaminated.

Tidal dynamics of the Terminos Lagoon, Mexico: observations and 3D numerical modelling

NASA Astrophysics Data System (ADS)

Contreras Ruiz Esparza, Adolfo; Douillet, Pascal; Zavala-Hidalgo, Jorge

2014-09-01

The tidal circulation patterns in the Terminos Lagoon were studied based on the analysis of 1 year of measurements and numerical simulations using a baroclinic 3D hydrodynamic model, the MARS3D. A gauging network was installed consisting of six self-recording pressure-temperature sensors, a tide gauge station and two current profilers, with pressure and temperature sensors moored in the main lagoon inlets. Model simulations were validated against current and sea level observations and were used to analyse the circulation patterns caused by the tidal forcing. The numerical model was forced with eight harmonic components, four diurnal ( K 1, O 1, P 1, Q 1) and four semi-diurnal ( M 2, S 2, N 2, K 2), extracted from the TPX0.7 database. The tidal patterns in the study area vary from mixed, mainly diurnal in the two main inlets of the lagoon, to diurnal in its interior. The tidal residual circulation inside the lagoon is dominated by a cyclonic gyre. The results indicate a net flux from the southwest Ciudad del Carmen inlet (CdC) towards the northeast Puerto Real inlet (PtR) along the southern side of the lagoon and the opposite in the northern side. The results indicate two areas of strong currents in the vicinity of the inlets and weak currents inside the lagoon. The area of strong currents in the vicinity of the CdC inlet is larger than that observed in the PtR inlet. Nevertheless, the current analysis indicates that the highest current speeds, which can reach a magnitude of 1.9 m s-1, occurred in PtR. A further analysis of the tide distortion in the inlets revealed that both passages are ebb dominated.

Biotic variation in coastal water bodies in Sussex, England: Implications for saline lagoons

NASA Astrophysics Data System (ADS)

Joyce, Chris B.; Vina-Herbon, Cristina; Metcalfe, Daniel J.

2005-12-01

Coastal water bodies are a heterogeneous resource typified by high spatial and temporal variability and threatened by anthropogenic impacts. This includes saline lagoons, which support a specialist biota and are a priority habitat for nature conservation. This paper describes the biotic variation in coastal water bodies in Sussex, England, in order to characterise the distinctiveness of the saline lagoon community and elucidate environmental factors that determine its distribution. Twenty-eight coastal water bodies were surveyed for their aquatic flora and invertebrate fauna and a suite of exploratory environmental variables compiled. Ordination and cluster analyses were used to examine patterns in community composition and relate these to environmental parameters. Biotic variation in the coastal water body resource was high. Salinity was the main environmental parameter explaining the regional distribution of taxa; freshwater and saline assemblages were evident and related to sea water ingress. Freshwater sites were indicated by the plant Myriophyllum spicatum and gastropod mollusc Lymnaea peregra, while more saline communities supported marine and brackish water taxa, notably a range of chlorophytic algae and the bivalve mollusc Cerastoderma glaucum. Site community differences were also related to bank slope and parameters describing habitat heterogeneity. A saline lagoon community was discerned within the matrix of biotic variation consisting of specialist lagoonal species with associated typically euryhaline taxa. For fauna, the latter were the molluscs Abra tenuis and Hydrobia ulvae, and the crustaceans Corophium volutator and Palaemonetes varians, and for flora they were the algae Ulva lactuca, Chaetomorpha mediterranea, Cladophora spp. and Enteromorpha intestinalis. One non-native polychaete species, Ficopomatus enigmaticus, also strongly influenced community structure within the lagoonal resource. The community was not well defined as specialist and

Organic matter composition in the sediment of three Brazilian coastal lagoons: district of Macaé, Rio de Janeiro (Brazil).

PubMed

Zink, Klaus-Gerhard; Furtado, André L S; Casper, Peter; Schwark, Lorenz

2004-03-01

Freshwater lagoons comprise important coastal ecosystems and natural buffers between urbanized land areas and open ocean in the Rio de Janeiro State, Brazil. Studies of sediment and water chemistry, zooplankton and bacterial communities to assess the extent of anthropogenic disturbance are available. Here we contribute with an organic-geochemical approach supplemented by some microbiological aspects to complete the characterization of these lagoonal ecosystems. Bulk organic matter and extractable lipids (aliphatic hydrocarbons, alcohols and fatty acids, sterols) were investigated from two locations per lagoon: at the seaward site and landward ends - and at two depth intervals (0-3 and 3-6 cm) per site. Urbanized Imboacica Lagoon received increased anthropogenic input over the most recent years represented by the topmost 3 cm of sediment, whereas deeper sediment layers are less affected by human influence. Eutrophication or nutrient availability favored enhanced algal/cyanobacterial growth. In remote Cabiúnas and Comprida Lagoons pristine conditions are preserved. Organic matter from vascular plants dominates (chain length of free lipids up to C36), which is exceptionally well preserved by acidic lagoonal waters. Differentiation between landward and seaward sites in these two lagoons is less well established due to much smaller surface/volume to catchment ratios. No anthropogenic influences are yet detectable in sediments of Cabiúnas and Comprida Lagoons.

KM3NeT

NASA Astrophysics Data System (ADS)

de Jong, M.

2015-07-01

KM3NeT is a large research infrastructure, that will consist of a network of deep-sea neutrino telescopes in the Mediterranean Sea. The main objective of KM3NeT is the discovery and subsequent observation of high-energy neutrino sources in the Universe. A further physics perspective is the measurement of the mass hierarchy of neutrinos. A corresponding study, ORCA, is ongoing within KM3NeT. A cost effective technology for (very) large water Cherenkov detectors has been developed based on a new generation of low price 3-inch photo-multiplier tubes. Following the successful deployment and operation of two prototypes, the construction of the KM3NeT research infrastructure has started. The prospects of the different phases of the implementation of KM3NeT are summarised.

Effects of regional climate changes on the planktonic ecosystem and water environment in the frozen Notoro Lagoon, northern Japan.

PubMed

Katsuki, Kota; Seto, Koji; Noguchi, Takuro; Sonoda, Takeshi; Kim, JuYong

2012-10-01

Diatom fossils from core sediments and living diatoms from water samples of Notoro Lagoon in northern Japan were examined to evaluate natural climate effects on lagoon environmental changes. In 1974, the artificial inlet was excavated. Immediately after, the anoxic bottom water in Notoro Lagoon began to disappear due to an increasing water exchange rate. However, chemical oxygen demand (COD) in the bottom water of Notoro Lagoon gradually increased, with fluctuations, during the last 30 years. In addition, the dominant diatom assemblages in Notoro Lagoon shifted to ice-related and spring bloom taxa after the excavation. The dominant taxa of each year in the sediment core were also strongly related to the timing of lagoon ice melting. This is because the COD in Notoro Lagoon was affected by the deposited volume of blooming diatoms, which was controlled by the duration of ice cover and the timing of ice discharge to the Okhotsk Sea likely due to an air pressure pattern change over the northern North Pacific like the Pacific Decadal Oscillation (PDO). Copyright © 2012 Elsevier Ltd. All rights reserved.

Metal pollution loading, Manzalah lagoon, Nile delta, Egypt: Implications for aquaculture

DOE Office of Scientific and Technical Information (OSTI.GOV)

Siegel, F.R.; Slaboda, M.L.; Stanley, D.J.

1994-03-01

High cultural enrichment factors are found for Hg (13 x), Pb (22.1 x), and other potentially toxic metals (e.g., Sn, Zn, Cu, Ag) in the upper 20 cm of sediment cores from the southeastern Ginka subbasin of Manzalah lagoon, Nile delta, Egypt. Cores from other areas of the lagoon show little metal loading. Metal loading followed the closure of the Aswan High Dam, the availability of abundant cheap electricity, and the development of major power-based industries. Industrial wastes containing potentially toxic metals are dumped into the Nile delta drain system. The load carried by Bahr El-Baqar drain discharges into themore » Ginka subbasin, which acts as a sink and results in metal loading of the sediment deposited there. Further development of aquaculture in this subbasin, of food-stuff agriculture on recently reclaimed lagoon bottom, or where irrigation waters come from Bahr El-Baqar drain or its discharge should be halted or strictly limited until potentially toxic metals in the drain waters and sediment are removed and polluted input drastically reduced. This environmental assessment of heavy metals in aquaculture or agriculture development should extend to other waterbodies in the northern Nile delta, particularly Idku lagoon and Lake Mariut, where industrial metal-bearing wastes discharge into the waterbodies. 21 refs., 7 figs., 3 tabs.« less

Distribution and sources of carbon, nitrogen, phosphorus and biogenic silica in the sediments of Chilika lagoon

NASA Astrophysics Data System (ADS)

Nazneen, Sadaf; Raju, N. Janardhana

2017-02-01

The present study investigated the spatial and vertical distribution of organic carbon (OC), total nitrogen (TN), total phosphorus (TP) and biogenic silica (BSi) in the sedimentary environments of Asia's largest brackish water lagoon. Surface and core sediments were collected from various locations of the Chilika lagoon and were analysed for grain-size distribution and major elements in order to understand their distribution and sources. Sand is the dominant fraction followed by silt + clay. Primary production within the lagoon, terrestrial input from river discharge and anthropogenic activities in the vicinity of the lagoon control the distribution of OC, TN, TP and BSi in the surface as well as in the core sediments. Low C/N ratios in the surface sediments (3.49-3.41) and cores (4-11.86) suggest that phytoplankton and macroalgae may be major contributors of organic matter (OM) in the lagoon. BSi is mainly associated with the mud fraction. Core C5 from Balugaon region shows the highest concentration of OC ranging from 0.58-2.34%, especially in the upper 30 cm, due to direct discharge of large amounts of untreated sewage into the lagoon. The study highlights that Chilika is a dynamic ecosystem with a large contribution of OM by autochthonous sources with some input from anthropogenic sources as well.

Lacaziosis in bottlenose dolphins (Tursiops truncatus) in the Indian River Lagoon, Florida, USA.

PubMed

Durden, Wendy Noke; St Leger, Judy; Stolen, Megan; Mazza, Teresa; Londono, Catalina

2009-07-01

The objective of this study was to document the presence of the fungal granulomatous skin disease lacaziosis in stranded Indian River Lagoon (IRL) bottlenose dolphins (Tursiops truncatus). From 1 January 2007 through 31 December 2007, stranded dolphins from the northern part of the IRL were thoroughly examined, and appropriate tissue samples were collected. The intralesional fungal agent (Lacazia loboi) was identified histologically in three bottlenose dolphins. Histologically, lacaziosis has been previously documented in IRL dolphins inhabiting the southern portion of the lagoon. Our findings suggest that the disease occurs throughout the lagoon. Enhanced monitoring of the prevalence of lacaziosis in dolphins throughout the IRL is needed to assess changes in population health.

[Clandestine slaughtering in Tunisia: investigation on the knowledge and practices of butchers concerning hydatidosis].

PubMed

Besbes, M; Sellami, H; Cheikhrouhou, F; Makni, F; Ayadi, A

2003-11-01

Echinococcosis is one of the major parasitic diseases in Tunisia, accounting for a considerable public health problem. We propose in this work to analyse the behaviour of butchers and to evaluate its impact on the hydatic cyst transmission. We carried out a national transversal descriptive survey that included 97 butcher shops using illegal practice, located in 18 regions (governorats) of Tunisia. The sampling procedure was implemented according to the level of disease endemicity. 60.8% of butcher shops were located along main roads and therefore supplying travellers. Among the animals slaughtered sheep come in first position (97.9%). More than 80% of the butchers kept aside a place around the butcher shop to sacrifice their animals. We noted the presence of dogs near butcher shop in 52.6% of cases and stray dogs in 43.3% of cases. Only 13.4% of the butchers knew the disease mode of transmission. Parasitized viscera were thrown into dustbins or further in the riverbed in 56.7%. More than 50% of butchers, having an inadequate behaviour in front of parasitized viscera or ignoring the disease cycle, were originating from an hyper or holoendemic area. Illegal slaughtering practices have an important impact on transmission of cystic echinococcosis in Tunisia.

Suicide and Fire: A 20-Year Study of Self-Immolation Death in Sousse, Tunisia.

PubMed

Jedidi, Maher; El Khal, Mohamed Cherif; Mlayeh, Souheil; Masmoudi, Tasnim; Mahjoub, Mohamed; Brahem, Mohamed Yassine; Ben Dhiab, Mohamed; Zemni, Majed; Souguir, Mohamed Kamel

Self-immolation is a self-destructive conduct described since antiquity. Its frequency is variable from one country to another and it is a real public health problem in parts of the world. In Tunisia, after the 2011 revolution the problem of self-immolation protest has been highly publicized giving the impression of an increase in this phenomenon. This is a retrospective analysis of all fatal self-immolation cases, collected over a 20-year period (1996-2015) at the Forensic Medicine Department of the Farhat Hached University Hospital, Sousse, Tunisia. A total of 41 cases were collected, of which 23 were men (56%). The mean age was 36.1 years. Prior to 2011, 78.9% of the victims of self-immolation were women and after 2011, 86.4% were men. The rural origin of the victims was found in 56.25% of the cases. History of psychiatric illness was found in four individuals. The self-immolation took place in the victims' homes in 19 cases (46.3%). It came after a conjugal or family conflict in 14 cases (34.1%) and it is of protest character in 8 cases (19.5%). This study confirmed the increasing frequency of self-immolation in Tunisia after the 2011 revolution and noted a change in the victims' profiles.

The Defense Committees of Sleepy Lagoon: A Convergent Struggle against Fascism, 1942-1944

ERIC Educational Resources Information Center

Barajas, Frank P.

2006-01-01

The Sleepy Lagoon Defense Committee originated as an ad hoc committee and evolved to a broad-based movement for legal justice on behalf of seventeen youth convicted of murder and assault charges in connection with the Sleepy Lagoon case in Los Angeles in January 1943. This essay chronicles the multidimensional organizing to shift public opinion in…

[Mangrove dynamics in the Cispata lagoon system (Colombian Caribbean) during last 900 years].

PubMed

Castaño, Ana; Urrego, Ligia; Bernal, Gladys

2010-12-01

The lagoon complex of Cispatá (old Sinú river delta) located at the Northwestern coast of the Colombian Caribbean, encloses one of the biggest mangrove areas in this region. This area has changed during the last 330 years because of several environmental and climatic causes, mainly changes in the position of the delta (Sinú River), which is the main freshwater source in this area, and sea level rise. We hypothesized that the climatic and geomorphologic dynamics has caused changes in the extension and composition of mangrove vegetation, especially during last 150 years. The dynamics of mangroves during the last 900 years was reconstructed based on the changes in the stratigraphy, pollen record, calcite concentrations (CaCO3) and C/N ratio, along two sediment cores from La Flotante and Navio lagoons, located in Cispatá complex. The age model was built based on lineal interpolation of 210Pb ages and changes in granulometry. Establishment and expansion of mangrove forests during the last 900 years were related to fluviomarine dynamics in the area and the lagoon formation. During the period encompassed between 1064 and 1762 A.D., the Mestizos spit was formed when marine conditions predominated in the surroundings of La Flotante Lagoon. At the site of Navío, a river dominated lagoon, terrigenous conditions dominated since 1830. Although the colonization of herbaceous pioneer vegetation started between 1142 and 1331 A.D., mangrove colonization only took place since 1717 A.D. Mangrove colonization was a result of the delta progradation. In 1849 A.D. the Sinú river delta migrated to the Cispatá bay. The eustatic sea level rise, the increase in river discharges and sedimentation rates produced the establishment of mangrove forests dominated by Rhizophora since 1849. Since 1900 a marine intrusion was recorded in both lagoons. In 1938, the migration of the delta toward its actual location in Tinajones gave place to the formation of the present lagoon system and to the

A new sampler for stratified lagoon chemical and microbiological assessments.

PubMed

McLaughlin, M R; Brooks, J P; Adeli, A

2014-07-01

A sampler was needed for a spatial and temporal study of microbial and chemical stratification in a large swine manure lagoon that was known to contain zoonotic bacteria. Conventional samplers were limited to collections of surface water samples near the bank or required a manned boat. A new sampler was developed to allow simultaneous collection of multiple samples at different depths, up to 2.3 m, without a manned boat. The sampler was tethered for stability, used remote control (RC) for sample collection, and accommodated rapid replacement of sterile tubing modules and sample containers. The sampler comprised a PVC pontoon with acrylic deck and watertight enclosures, for a 12 VDC gearmotor, to operate the collection module, and vacuum system, to draw samples into reusable autoclavable tubing and 250-mL bottles. Although designed primarily for water samples, the sampler was easily modified to collect sludge. The sampler held a stable position during deployment, created minimal disturbance in the water column, and was readily cleaned and sanitized for transport. The sampler was field tested initially in a shallow fresh water lake and subsequently in a swine manure treatment lagoon. Analyses of water samples from the lagoon tests showed that chemical and bacterial levels, pH, and EC did not differ between 0.04, 0.47, and 1.0 m depths, but some chemical and bacterial levels differed between winter and spring collections. These results demonstrated the utility of the sampler and suggested that future manure lagoon studies employ fewer or different depths and more sampling dates.

Water hyacinths for upgrading sewage lagoons to meet advanced wastewater treatment standards, part 2

NASA Technical Reports Server (NTRS)

Wolverton, B. C.; Mcdonald, R. C.

1976-01-01

Field tests using water hyacinths as biological filtration agents were conducted in the Mississippi gulf coast region. The plants were installed in one single cell and one multiple cell sewage lagoon systems. Water hyacinths demonstrated the ability to maintain BOD5 and total suspended solid (TSS) levels within the Environmental Protection Agency's prescribed limits of 30 mg/lBOD5 and 30 mg/l TSS. A multiple cell sewage lagoon system consisting of two aerated and one water hyacinth covered cell connected in series demonstrated the ability to maintain BOD5 and TSS levels below 30 mg/l year-round. A water hyacinth covered lagoon with a surface area of 0.28 hectare containing a total volume of 6.8 million liters demonstrated the capacity to treat 437,000 to 1,893,000 liters of sewage influent from 2.65 hectares of aerated lagoons daily and produce an effluent that met or exceeded standards year-round.

The United States and Tunisia: A Foreign Policy Analysis.

DTIC Science & Technology

1985-12-01

headquarters to Tunis from Cairo following the signing of the Egypt- Israel peace treaty, and when the Palestine Liberation Organization .- set up its... Israel [Ref. 201. Such a message serves only to reinforce the appeal of Populist Islam. It is probable that the Islamic movement will, if well...THE ARAB-ISRAELI CONFLICT~ Tunisia has been a consistent supporter of the rights of Palestina * Arabs, but the Bourguibist idea of how Palestinians

Calibration of Linked Hydrodynamic and Water Quality Model for Santa Margarita Lagoon

DTIC Science & Technology

2016-07-01

was used to drive the transport and water quality kinetics for the simulation of 2007–2009. The sand berm, which controlled the opening/closure of...TECHNICAL REPORT 3015 July 2016 Calibration of Linked Hydrodynamic and Water Quality Model for Santa Margarita Lagoon Final Report Pei...Linked Hydrodynamic and Water Quality Model for Santa Margarita Lagoon Final Report Pei-Fang Wang Chuck Katz Ripan Barua SSC Pacific James

Characterization of a Mud Deposit Offshore of the Patos Lagoon, Southern Brazil

DTIC Science & Technology

2009-02-01

Journal Article 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE Characterization of mud deposit offshore of the Patos lagoon, southern Brazil 5a...deposition of mud on the beach along the shoreface of Rio Grande do Sul, Brazil dramatically influences the normal operations in the littoral zone...Continental Shelf Research journal homepage: www.elsevier.com/locate/csr Characterization of a mud deposit offshore of the Patos Lagoon, southern Brazil

Growth, Survival and Reproduction of the Giant Clam Tridacna maxima (Röding 1798, Bivalvia) in Two Contrasting Lagoons in French Polynesia

PubMed Central

Van Wynsberge, Simon; Andréfouët, Serge; Gaertner-Mazouni, Nabila; Wabnitz, Colette C. C.; Menoud, Mathilde; Le Moullac, Gilles; Levy, Peva; Gilbert, Antoine; Remoissenet, Georges

2017-01-01

Shell growth, reproduction, and natural mortality of the giant clam Tridacna maxima were characterized over a two-year-period in the lagoon of the high island of Tubuai (Austral Archipelago) and in the semi-closed lagoon of Tatakoto (Tuamotu Archipelago) in French Polynesia. We also recorded temperature, water level, tidal slope, tidal range, and mean wave height in both lagoons. Lower lagoon aperture and exposure to oceanic swells at Tatakoto than at Tubuai was responsible for lower lagoon water renewal, as well as higher variability in temperature and water level at Tatakoto across the studied period. These different environmental conditions had an impact on giant clams. Firstly, spawning events in the lagoon of Tatakoto, detected by gonad maturity indices in June and July 2014, were timed with high oceanic water inflow and a decrease in lagoon water temperature. Secondly, temperature explained differences in shell growth rates between seasons and lagoons, generating different growth curves for the two sites. Thirdly, local mortality rates were also found to likely be related to water renewal patterns. In conclusion, our study suggests that reef aperture and lagoon water renewal rates play an integral role in giant clam life history, with significant differences in rates of shell growth, mortality and fertility found between open versus semi-closed atoll lagoons in coral reef ecosystems. PMID:28118406

Hydrologic characteristics of lagoons at San Juan, Puerto Rico, during an October 1974 tidal cycle

USGS Publications Warehouse

Gómez-Gómez, Fernando; Ellis, S.R.

1983-01-01

Flow and water-quality changes were studied during a period of intense rainfall in the San Juan Lagoon system. The study covered a 25-hour period beginning 0900 hours 22 October, 1974. Precipitation during the study period averaged 70 millimeters. Sampling stations were located at Boca de Cangrejos, the main ocean outlet; Canal Pinones between Laguna de Pinones and Laguna La Torrecilla; Canal Suarez between Laguna San Jose, connects to Laguna La Torrecilla; and Cano de Martin Pena between Laguna San Jose and Bahia de San Juan. In addition water-elevation recording gages were installed at each lagoon. Water samples from the canal stations were analyzed for organic carbon, nitrogen and phosphorus species, and suspended sediment. Specific-conductance measurements were used with the chemical data to estimate the runoff contributions of nutrients. Runoff into the lagoon, system during the study period was about 2.8 million cubic meters, or about 70 percent of the average precipitation. The runoff contributed chemical loadings to the lagoons of 95,000 kilograms total-organic carbon; 2,700 kilograms of total phosphorus; and 10,000 kilograms of total Khjeldhal nitrogen. A comparison with a prior study during which there was no significant rain, show that dry-period loadings are less than 10 percent of the wet-period loadings. At the end of the study period the system had not reached equilibrium, and the lagoons retained 80 percent of the water inflows from 50 to 90 percent of the chemical loads. Nearly 95 percent of the water outflows occurred at the Boca de Cangrejos sea outlet. The three lagoons and interconnecting canals form a very complex hydraulic system that is difficult to study using traditional techniques. A model of the system will facilitate management to improve the quality of water in the lagoons.

Hydrological behavior of coastal lagoons associated to wetlands, an example from southernmost bahía Samborombón (Argentina).

NASA Astrophysics Data System (ADS)

Tejada Tejada, Macarena; Carol, Eleanora; Galliari, Julieta; Richiano, Sebastian

2017-04-01

Coastal wetlands are located at a critical interface between the terrestrial and marine environments and are ideally positioned to reduce impacts from land-based sources. At the southern region of Bahía Samborombón (Argentina) the wetlands includes several small coastal lagoons developed inside of a sandy spike. The main object of this work is to analyze the hydrological behavior of the lagoons evaluating their role in the maintenances of the wetland. In order to do this, satellite image analysis was performed to identify the marshy areas, drainage features, morphology and connections of the lagoons, both with the tidal flows from the Río de la Plata estuary and from the Argentine Sea. Field surveys were carried out in one of the lagoons to define their geological and geomorphological characteristics. After that, a monitoring network was designed for sampling the superficial and the underground water, additionally electrical conductivity and pH of the water were determined in situ. In all the water samples extracted the content of majority ions was determined by standard methods. Complementary, sedimentological and malacological aspects were observed at several stations in the lagoon. The obtained results allow us to recognize that the tidal flow that enters from the sea, at least in the studied lagoon, is the main hydrological sustenance of the wetland. This flow enters mainly using one tidal channel which connects (in a semi-permanent way) the sea with the lagoon during extraordinary tide and storm events. During low tide the lagoon loses connection and the drainage towards the sea is scarce. The tidal water that accumulates in the lagoon is subsequently evaporated causing an increase in the salinity of the surface water to values higher than the sea. Groundwater that accumulates through the infiltration of rainfall in the sandy sediments of the spike also discharges to the lagoon and supports the wetland surrounding the coastal lagoon. This flow, even when it

KM3NeT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jong, M. de; Leiden Institute of Physics, Leiden University, Leiden; Collaboration: KM3NeT Collaboration

2015-07-15

KM3NeT is a large research infrastructure, that will consist of a network of deep-sea neutrino telescopes in the Mediterranean Sea. The main objective of KM3NeT is the discovery and subsequent observation of high-energy neutrino sources in the Universe. A further physics perspective is the measurement of the mass hierarchy of neutrinos. A corresponding study, ORCA, is ongoing within KM3NeT. A cost effective technology for (very) large water Cherenkov detectors has been developed based on a new generation of low price 3-inch photo-multiplier tubes. Following the successful deployment and operation of two prototypes, the construction of the KM3NeT research infrastructure hasmore » started. The prospects of the different phases of the implementation of KM3NeT are summarised.« less

Microcystins Presence in Mussels (M. galloprovincialis) and Water of Two Productive Mediterranean's Lagoons (Sardinia, Italy)

PubMed Central

Baralla, Elena; Varoni, Maria Vittoria; Sedda, Tiziana; Floris, Antonello; Demontis, Maria Piera

2017-01-01

Microcystins (MCs) are hepatotoxins harmful for animal and human health. The most toxic type between them is MC-LR whose presence has been investigated in different reservoirs all around the world. In this work microcystins were monitored in spring and summer in water and mussels (Mytilus galloprovincialis) of two Sardinia lagoons: Cabras and Calich lagoons. A Solid Phase Extraction method was developed to clean and concentrate samples before the Enzyme Linked Immunosorbent Assay (ELISA) and the following Mass Spectrometry detection. MCs presence was detected using the screening ELISA test in both lagoons. MCs peak was revealed in July for water and mussels belonging to Cabras lagoon (0.75 ± 0.07 ng/L in water and 0.12 ± 0.04 ng/g ww in mussels). In water of Calich lagoon there was a constant trend in the concentration of MCs during the considered months, while there was a MCs peak in July (0.6 ± 0.5 ng/g ww) in mussels. The following LC-MS/MS analysis did not reveal MC-LR presence in all analyzed samples. These results can be useful to enrich knowledge on public health and consumer's safeguard. PMID:29359150

First Report on Natural Infection of Phlebotomus sergenti with Leishmania Promastigotes in the Cutaneous Leishmaniasis Focus in Southeastern Tunisia

PubMed Central

Tabbabi, Ahmed; Bousslimi, Nadia; Rhim, Adel; Aoun, Karim; Bouratbine, Aïda

2011-01-01

During September 2010, 133 female sand flies were caught inside houses of patients with cutaneous leishmaniasis in the focus for this disease in southeastern Tunisia and subsequently dissected. One specimen was positive for Leishmania protozoa. This sand fly species was identified as Phlebotomus sergenti, and the parasite was identified as L. tropica. This is the first report of P. sergenti involvement in transmission of L. tropica in Tunisia. PMID:21976566

Water-Quality Monitoring and Biological Integrity Assessment in the Indian River Lagoon, Florida: Status, Trends, and Loadings (1988-1994).

PubMed

Sigua; Steward; Tweedale

2000-02-01

/ The Indian River Lagoon (IRL) system that extends from Ponce DeLeon Inlet to Jupiter Inlet is comprised of three interconnected estuarine lagoons: the Mosquito Lagoon (ML), the Banana River Lagoon (BRL), and the Indian River Lagoon (subdivided into North Indian River Lagoon, NIRL and the South Indian River Lagoon, SIRL). The declines in both the areal coverage and species diversity of seagrass communities within the IRL system are believed to be due in part to continued degradation of water quality. Large inflows of phosphorus (P) and nitrogen (N) -laden storm-water from urban areas and agricultural land have been correlated with higher chlorophyll a production in the central, south central, and the south segments of the lagoon. In a system as large and complex as the lagoon, N and P limitations are potentially subject to significant spatial and temporal variability. Total Kjeldahl nitrogen (TN) was higher in the north (1.25 mg/liter) and lower in the south (0.89 mg/liter). The reverse pattern was observed for total P (TP), i.e., lowest in the north (0.03 mg/liter) and highest at the south (0.14 mg/liter) ends of the IRL. This increased P concentration in the SIRL appears to have a significantly large effect on chlorophyll a production compared with the other segments, as indicated by stepwise regression statistics. This relationship can be expressed as follows: South IRL [chlorophyll a] = -8.52 + 162.41 [orthophosphate] + 7.86 [total nitrogen] + 0.38 [turbidity]; R(2) = 0.98**.

Tracing organic matter sources in a tropical lagoon of the Caribbean Sea

NASA Astrophysics Data System (ADS)

Alonso-Hernández, Carlos M.; Garcia-Moya, Alejandro; Tolosa, Imma; Diaz-Asencio, Misael; Corcho-Alvarado, Jose Antonio; Morera-Gomez, Yasser; Fanelli, Emanuela

2017-09-01

The natural protected lagoon of Guanaroca, located between Cienfuegos Bay and the Arimao River, Cuba, has been heavily impacted by human-induced environmental changes over the past century. Sources of organic matter in the Guanaroca lagoon and concentrations of radioisotopes (210Pb, 226Ra, 137Cs and 239,240Pu), as tracers of anthropogenic impacts, were investigated in a 78 cm sediment core. Variations in total organic carbon (TOC), total nitrogen (TN), stable isotopic composition (δ13C and δ15N) and ratio of total organic carbon to total nitrogen (C/N) were analysed. On such a basis, environmental changes in the lagoon were revealed. Down core variation patterns of the parameters representing sources of organic matter were predominantly related to the impacts of human activities. Up to the nineteenth century, the principal sources of organic matter to sediments (more than 80%) were a mixing of terrestrial vascular plants ( 48%) and freshwater phytoplankton ( 8%), with minimal contribution from the marine component ( 16%). In the period 1900-1980, due to the strong influence of human activities in the catchment area, the water exchange capacity of the lagoon declined substantially, as indicated by the relatively high proportion of organic matter originated from human activities (58%). Since 1980, as a result of management actions in the protected area, the lagoon has regained gradually its capability to exchange freshwater, showing sources of organic matter similar to the natural conditions recorded previous to 1900, although an indication of human impact (treated sewage contributed for 26% to the organic matter in sediments) was still observed and further management measures would be required.

Assessment of human activities impact on groundwater quality discharging into a reef lagoon

NASA Astrophysics Data System (ADS)

Rebolledo-Vieyra, M.; Hernandez, L.; Paytan, A.; Merino-Ibarra, M.; Lecossec, A.; Soto, M.

2010-03-01

The Eastern coast of the Yucatan Peninsula has the fastest growth rate in Mexico and groundwater is the only source of drinking water in the region. The consequences of the lack of proper infrastructure to collect and treat wastewater and the impact of human activities on the quality of groundwater are addressed. The groundwater in the coastal aquifer of Quintana Roo (SE Mexico) discharges directly into the ocean (Submarine Groundwater Discharges). In addition, the coral reef of the Eastern Yucatan Peninsula is part of the Mesoamerican Coral Reef System, one of the largest in the world. The interaction of the reef-lagoon hydraulics with the coastal aquifer of Puerto Morelos (NE Yucatan Peninsula), and a major input of NH4, SO4, SiO2, as a consequence of the use of septic tanks and the lack of modern wastewater treatment plants are presented. A conceptual model of the coastal aquifer was developed, in order to explain how the human activities are impacting directly on the groundwater quality that, potentially, will have a direct impact on the coral reef. The protection and conservation of coral reefs must be directly related with a policy of sound management of coastal aquifers and wastewater treatment.

River capture and sediment redistribution in northern Tunisia: The doom of Utica

NASA Astrophysics Data System (ADS)

Booth-Rea, Guillermo; Camafort, Miquel; Pérez-Peña, J. Vicente; Melki, Fetheddine; Ranero, César; Azañón, José Miguel; Gracia, Eulalia; Ouadday, Mohamed

2016-04-01

Utica was a flourishing port city in northern Tunisia since the Phoenician times, 12-9th century B.C., until the 4th century A.D.. However, at present it is located 10 km from the coastline after very fast late Holocene progradation of the Mejerda River delta into the bay of Utica. This fast delta progradation occurred after Mejerda River captured Tine River increasing 140 % the river catchment area. Charcoal fragments present in the youngest Tine river terrace at the wind gap give a conventional radiocarbon age of 3240 +/- 30yr BP, indicating that the capture occurred after this date. Quaternary fluvial terraces located in the Tine River paleovalley have been folded and uplifted above a fold related to the active El Alia Tebousouk reverse fault (ETF). Continued uplift of the Tine River valley above the ETF favoured headward erosion of the Medjerda river tributaries creating a transverse drainage that captured Tine River. This capture produced an important change in sediment discharge along the northern Tunisia coast driving sediments to the Gulf of Tunis instead of feeding the Tyrrhenian Sea through the Ichkeul and Bizerte lakes. Although anthropogenic derived degradation of northern Tunisia land for agricultural purposes probably influenced the increase in sediment into the Utica bay, the main cause of rapid progradation of the Medjerda River delta during the late Holocene is related to its increase in drainage area after capturing the Tine River. This process was mostly driven by local contractive tectonics linked to the seismogenic Alia Tebousouk reverse fault.

Errors and uncertainties in regional climate simulations of rainfall variability over Tunisia: a multi-model and multi-member approach

NASA Astrophysics Data System (ADS)

Fathalli, Bilel; Pohl, Benjamin; Castel, Thierry; Safi, Mohamed Jomâa

2018-02-01

Temporal and spatial variability of rainfall over Tunisia (at 12 km spatial resolution) is analyzed in a multi-year (1992-2011) ten-member ensemble simulation performed using the WRF model, and a sample of regional climate hindcast simulations from Euro-CORDEX. RCM errors and skills are evaluated against a dense network of local rain gauges. Uncertainties arising, on the one hand, from the different model configurations and, on the other hand, from internal variability are furthermore quantified and ranked at different timescales using simple spread metrics. Overall, the WRF simulation shows good skill for simulating spatial patterns of rainfall amounts over Tunisia, marked by strong altitudinal and latitudinal gradients, as well as the rainfall interannual variability, in spite of systematic errors. Mean rainfall biases are wet in both DJF and JJA seasons for the WRF ensemble, while they are dry in winter and wet in summer for most of the used Euro-CORDEX models. The sign of mean annual rainfall biases over Tunisia can also change from one member of the WRF ensemble to another. Skills in regionalizing precipitation over Tunisia are season dependent, with better correlations and weaker biases in winter. Larger inter-member spreads are observed in summer, likely because of (1) an attenuated large-scale control on Mediterranean and Tunisian climate, and (2) a larger contribution of local convective rainfall to the seasonal amounts. Inter-model uncertainties are globally stronger than those attributed to model's internal variability. However, inter-member spreads can be of the same magnitude in summer, emphasizing the important stochastic nature of the summertime rainfall variability over Tunisia.

Assessing pollution in a Mediterranean lagoon using acid volatile sulfides and estimations of simultaneously extracted metals.

PubMed

Zaaboub, Noureddine; Helali, Mohamed Amine; Martins, Maria Virgínia Alves; Ennouri, Rym; Béjaoui, Béchir; da Silva, Eduardo Ferreira; El Bour, Monia; Aleya, Lotfi

2016-11-01

Bizerte Lagoon is a southern Mediterranean semi-enclosed lagoon with a maximum depth of 12 m. After assessing sediment quality, the authors report on the physicochemical characteristics of the lagoon's surface sediment using SEM (simultaneously extracted metals) and AVS (acid volatile sulfides) as proxies. Biogeochemical tools are used to investigate the environmental disturbance at the water-sediment interface by means of SEM and AVS to seek conclusions concerning the study area's pollution status. Results confirm accumulation of trace elements in sediment. The use of the SEM-AVS model with organic matter in sediment (ƒOC) confirms possible bioavailability of accumulated trace elements, especially Zn, in the southern part of the lagoon, with organic matter playing an important role in SEM excess correction to affirm a nontoxic total metal sediment state. Individual trace element toxicity is dependent on the bioavailable fraction of SEM Metal on sediment, as is the influence of lagoon inflow from southern water sources on element bioavailability. Appropriate management strategies are highly recommended to mitigate any potential harmful effects on health from this heavy-metal-based pollution.

Recent sea-level changes and related engineering problems in the Lagoon of Venice (Italy)

NASA Astrophysics Data System (ADS)

Pirazzoli, Paolo Antonio

In the city of Venice, where the average altitude is only a few tens of centimetres, there has been a dangerous increase in the frequency of flooding during the past few decades. Since 1872, the average increase in flooding levels (“acqua alta”) has been about 40cm: 27cm of this is due to the local rise in mean sea-level (of which some 14cm are related to man-induced subsidence of land, and 3-7cm to geological factors), and at least 14cm are caused by hydrodynamical factors, of which about 10cm can be ascribed to man-induced tidal changes. These latter are due above all to the dredging of deep artificial channels, the reclamation of wide areas of tidal flats, and the diking of fish ponds (“valli”), which have changed the ratio between the surface of the lagoon and that of the inlets. Since the latest modification (1963-1969), the lagoon has been open to large oil tankers, thereby allowing an easier entry of storm surges arising out at sea. Indeed an incompatibility exists between the accessibility of very large boats to the lagoon and the safeguard of Venice. Several engineering projects have been proposed with a view to improving the present critical situation. These projects include underground injections to raise the islands, the construction of new embankments, a reduction in the size of the passes, new access to wide areas for the tide, and the construction of flood gates at the passes. The reliability and effects of these projects are analysed and discussed. In conclusion, the removal of the oil terminal from the lagoon and a stricter control of water pollution are considered the most urgent preliminary actions for a long term solution of the flooding problem. This would enable a decrease in the exchanges between the lagoon and the sea, without, however, reducing the depth of the navigation channels to levels inconsistent with most of the present non-oil traffic. A final measure would be the construction of mobile gates at the passes which would

Recovery of viruses from field samples of raw, digested, and lagoon-dried sludges*

PubMed Central

Sattar, Syed A.; Westwood, J. C. N.

1979-01-01

In a 22-month study, viruses were detected in 84% (62/74) of raw, 53% (19/36) of anaerobically digested, and 39% (11/28) of lagoon-dried sludge samples. Lagoon sludge contained detectable viruses (reovirus and enterovirus groups) even after 8 months of retention. Because of such prolonged virus survival in sludge, care must be taken in its disposal or utilization. PMID:311705

Depositional history and fault-related studies, Bolinas Lagoon, California

USGS Publications Warehouse

Berquist, Joel R.

1978-01-01

Studies of core sediments and seismic reflection profiles elucidate the structure and depositional history of Bolinas Lagoon, Calif., which covers 4.4 km 2 and lies in the San Andreas fault zone at the southeast corner of the Point Reyes Peninsula 20 km northwest of San Francisco. The 1906 trace of the San Andreas fault crosses the west side of the lagoon and was determined from (1) tectonically caused salt-marsh destruction indicated by comparison of 1854 and 1929 U.S. Coast and Geodetic Survey (U.S.C. & G.S.) topographic surveys, (2) formation of a tidal channel along the border of destroyed salt marshes, and (3) azimuths of the trend of the fault measured in 1907. Subsidence in the lagoon of 30 cm occurred east of the San Andreas fault in 1906. Near the east shore, seismic-reflection profiling indicates the existence of a graben fault that may connect to a graben fault on the Golden Gate Platform. Comparison of radiocarbon dates on shells and plant debris from boreholes drilled on Stinson Beach spit with a relative sea-level curve constructed for southern San Francisco Bay indicates 5.8 to more than 17.9 m of tectonic subsidence of sediments now located 33 m below mean sea level. Cored sediments indicate a marine transgression dated at 7770?65 yrs B.P. overlying freshwater organic-rich lake deposits. Fossil pollen including 2 to 8 percent Picea (spruce) indicate a late Pleistocene (?)-Early Holocene climate, cooler, wetter, and foggier than at present. Above the transgression are discontinuous and interfingering sequences of transgressive-regressive marine, estuarine, and barrier sediments that reflect rapid lateral and vertical shifts of successive depositional environments. Fossil megafauna indicate (1) accumulation in a protected, shallow-water estuary or bay, and (2) that the lagoon was probably continuously shallow and never a deep-water embayment. Analysis of grain-size parameters, pollen frequencies, and organic remains from a core near the north end of

A new model evaluating Holocene sediment dynamics: Insights from a mixed carbonate-siliciclastic lagoon (Bora Bora, Society Islands, French Polynesia, South Pacific)

NASA Astrophysics Data System (ADS)

Isaack, Anja; Gischler, Eberhard; Hudson, J. Harold; Anselmetti, Flavio S.; Lohner, Andreas; Vogel, Hendrik; Garbode, Eva; Camoin, Gilbert F.

2016-08-01

Mixed carbonate-siliciclastic lagoons of barrier reefs provide great potential as sedimentary archives focusing on paleoenvironmental and paleoclimatic changes as well as on event deposition. Sediment sources include lagoonal carbonate production, the marginal reef and the volcanic hinterland. Mixed carbonate-siliciclastic continent-attached coastal lagoons have been intensively studied, however, their isolated oceanic counterparts have been widely disregarded. Here, we present a new model of Holocene sediment dynamics in the barrier-reef lagoon of Bora Bora based on sedimentological, paleontological, geochronological and geochemical data. The lagoonal succession started with a Pleistocene soil representing the Lowstand Systems Tract. As the rising Holocene sea inundated the carbonate platform, peat accumulated locally 10,650-9400 years BP. Mixed carbonate-siliciclastic sedimentation started ca. 8700-5500 years BP and represents the Transgressive Systems Tract. During that time, sediments were characterized by relatively coarse grain size and contained high amounts of terrestrial material from the volcanic hinterland as well as carbonate sediments mainly produced within the lagoon. Siliciclastic content decreases throughout the Holocene. After the rising sea had reached its modern level, sand aprons formed between reef crest and lagoon creating transport pathways for reef-derived material leading to carbonate-dominated sedimentation ca. 6000-3000 years BP during the Highstand Systems Tract. However, mainly fine material was transported and accumulated in the lagoon while coarser grains were retained on the prograding sand apron. From ca. 4500-500 years BP, significant variations in grain-size, total organic carbon as indicator for primary productivity, Ca and Cl element intensities as qualitative indicators for carbonate availability and lagoonal salinity are seen. Such patterns could indicate event (re-)deposition and correlate with contemporaneous event deposits

Fulbright-Hays Seminars Abroad Program 1992: Morocco and Tunisia. Final Projects.

ERIC Educational Resources Information Center

AMIDEAST, Washington, DC.

The projects described in this document were submitted by U.S. teachers who spent time in Morocco and Tunisia as part of the 1992 Fulbright-Hays Seminars Abroad Program. The following are among the titles of the projects included: "Formal Education in Rural Morocco: Problems and Constraints" (Victoria Baker); "Continuity and Change…

Comprehensive assessment of hormones, phytoestrogens, and estrogenic activity in an anaerobic swine waste lagoon

USGS Publications Warehouse

Yost, Erin E.; Meyer, Michael T.; Dietze, Julie E.; Meissner, Benjamin M.; Williams, Mike; Worley-Davis, Lynn; Lee, Boknam; Kullman, Seth W.

2013-01-01

In this study, the distribution of steroid hormones, phytoestrogens, and estrogenic activity was thoroughly characterized within the anaerobic waste lagoon of a typical commercial swine sow operation. Three independent rounds of sampling were conducted in June 2009, April 2010, and February 2011. Thirty-seven analytes in lagoon slurry and sludge were assessed using LC/MS-MS, and yeast estrogen screen was used to determine estrogenic activity. Of the hormone analytes, steroidal estrogens were more abundant than androgens or progesterone, with estrone being the predominant estrogen species. Conjugated hormones were detected only at low levels. The isoflavone metabolite equol was by far the predominant phytoestrogen species, with daidzein, genistein, formononetin, and coumestrol present at lower levels. Phytoestrogens were often more abundant than steroidal estrogens, but contributed minimally towards total estrogenic activity. Analytes were significantly elevated in the solid phases of the lagoon; although low observed log KOC values suggest enhanced solubility in the aqueous phase, perhaps due to dissolved or colloidal organic carbon. The association with the solid phase, as well as recalcitrance of analytes to anaerobic degradation, results in a markedly elevated load of analytes and estrogenic activity within lagoon sludge. Overall, findings emphasize the importance of adsorption and transformation processes in governing the fate of these compounds in lagoon waste, which is ultimately used for broadcast application as a fertilizer.

Comprehensive Assessment of Hormones, Phytoestrogens, and Estrogenic Activity in an Anaerobic Swine Waste Lagoon

PubMed Central

2013-01-01

In this study, the distribution of steroid hormones, phytoestrogens, and estrogenic activity was thoroughly characterized within the anaerobic waste lagoon of a typical commercial swine sow operation. Three independent rounds of sampling were conducted in June 2009, April 2010, and February 2011. Thirty-seven analytes in lagoon slurry and sludge were assessed using LC/MS-MS, and yeast estrogen screen was used to determine estrogenic activity. Of the hormone analytes, steroidal estrogens were more abundant than androgens or progesterone, with estrone being the predominant estrogen species. Conjugated hormones were detected only at low levels. The isoflavone metabolite equol was by far the predominant phytoestrogen species, with daidzein, genistein, formononetin, and coumestrol present at lower levels. Phytoestrogens were often more abundant than steroidal estrogens, but contributed minimally toward total estrogenic activity. Analytes were significantly elevated in the solid phases of the lagoon; although low observed log KOC values suggest enhanced solubility in the aqueous phase, perhaps due to dissolved or colloidal organic carbon. The association with the solid phase, as well as recalcitrance of analytes to anaerobic degradation, results in a markedly elevated load of analytes and estrogenic activity within lagoon sludge. Overall, findings emphasize the importance of adsorption and transformation processes in governing the fate of these compounds in lagoon waste, which is ultimately used for broadcast application as a fertilizer. PMID:24144340

Scattering study of the Ne + NeH{sup +}(v{sub 0} = 0, j{sub 0} = 0) → NeH{sup +} + Ne reaction on an ab initio based analytical potential energy surface

DOE Office of Scientific and Technical Information (OSTI.GOV)

Koner, Debasish; Panda, Aditya N., E-mail: adi07@iitg.ernet.in; Barrios, Lizandra

2016-01-21

Initial state selected dynamics of the Ne + NeH{sup +}(v{sub 0} = 0, j{sub 0} = 0) → NeH{sup +} + Ne reaction is investigated by quantum and statistical quantum mechanical (SQM) methods on the ground electronic state. The three-body ab initio energies on a set of suitably chosen grid points have been computed at CCSD(T)/aug-cc-PVQZ level and analytically fitted. The fitting of the diatomic potentials, computed at the same level of theory, is performed by spline interpolation. A collinear [NeHNe]{sup +} structure lying 0.72 eV below the Ne + NeH{sup +} asymptote is found to be the most stablemore » geometry for this system. Energies of low lying vibrational states have been computed for this stable complex. Reaction probabilities obtained from quantum calculations exhibit dense oscillatory structures, particularly in the low energy region and these get partially washed out in the integral cross section results. SQM predictions are devoid of oscillatory structures and remain close to 0.5 after the rise at the threshold thus giving a crude average description of the quantum probabilities. Statistical cross sections and rate constants are nevertheless in sufficiently good agreement with the quantum results to suggest an important role of a complex-forming dynamics for the title reaction.« less

Clipperton, a possible future for atoll lagoons

NASA Astrophysics Data System (ADS)

Charpy, L.; Rodier, M.; Couté, A.; Perrette-Gallet, C.; Bley-Loëz, C.

2010-09-01

Closure of the Clipperton Island atoll (10°17' N 109°13' W), now a meromictic lake, is estimated to have occurred between 1839 and 1849. It was still closed in 2005. Brackish waters in the upper layer (0-10 m) were oxygenated, while saline waters in the deep layer (>20 m) were anoxic. Allowing for the methodological difficulties of earlier measurements, the physical characteristics of the lagoon did not seem to have changed significantly since the last expedition (1980). The intermediate layer between brackish and saline waters was characterized by a strong density gradient and a temperature inversion of up to 1.6°C. Microbial activity, water exchange between the deep layer and surrounding oceanic waters and the geothermal flux hypothesis are discussed. The low DIN and SRP concentrations observed in the upper layer, despite high nutrient input by seabird droppings, reflect the high nutrient uptake by primary producers as attested by the elevated overall gross primary production (6.6 g C m-2 day-1), and high suspended photosynthetic biomass (2.23 ± 0.23 μg Chl a l-1) and production (263 ± 27 μg C l-1 day-1). Phytoplankton composition changed in 67 years with the advent of new taxa and the disappearance of previously recorded species. The freshwater phytoplanktonic community comprised 43 taxa: 37 newly identified during the expedition and 6 previously noted; 16 species previously found were not seen in 2005. The closure of the lagoon, combined with the positive precipitation-evaporation budget characteristic of the region, has induced drastic changes in lagoon functioning compared with other closed atolls.

Dissolved Copper, Nickel and Lead in Tampamachoco Lagoon and Tuxpan River Estuary in the SW Gulf of Mexico.

PubMed

Garduño Ruiz, E P; Rosales Hoz, L; Carranza Edwards, A

2016-10-01

In order to estimate the effects of a thermal power plant, physicochemical parameters and the concentrations of copper, nickel and lead were evaluated in water from both Tampamachoco Lagoon and the estuary of the Tuxpan River. Average salinities were 33.66 ups in the lagoon area, 32.77 ups in the channel that joins the lagoon and the river, and 24.74 ups in the river estuary. Total average metal concentrations were 21.95 for Cu, 29.67 for Ni and 4.31 µ/L for Pb. Sampling point 1 and samples from the bottom water of the lagoon present the highest salinities and concentrations of suspended matter, TOC, Cu, Ni and Pb.These high values may be associated with the infiltration of sea water either from plant operation or from the channel that connects the lagoon with the sea.

Phleboviruses associated with sand flies in arid bio-geographical areas of Central Tunisia.

PubMed

Dachraoui, K; Fares, W; Bichaud, L; Barhoumi, W; Beier, J C; Derbali, M; Cherni, S; Lamballerie, X de; Chelbi, I; Charrel, R N; Zhioua, E

2016-06-01

An entomological investigation was carried out in 2014 at two sites located in Central Tunisia, one irrigated and another non-irrigated situated in arid bio-geographical areas. Sand flies of the subgenus Larroussius namely Phlebotomus perfiliewi, Phlebotomus perniciosus, and Phlebotomus longicuspis are the most abundant sand fly species in the irrigated site. However, in the non-irrigated site, Phlebotomus papatasi of the Phlebotomus genus is the most abundant species. A total of 3191 sand flies were collected and pooled with up to 30 specimens per pool based on sex, trapping location and collection date, were tested for the presence of phleboviruses by nested reverse transcriptase polymerase chain reaction in the polymerase gene and sequenced. Of a total of 117 pools, 4 were positive, yielding a minimum infection rate of sand flies with phleboviruses of 0.12%. Phylogenetic analysis performed using partial nucleotide and amino acid sequence in the polymerase gene showed that these phleboviruses belonged to four different clusters corresponding to Toscana virus (TOSV), Saddaguia virus (SADV), Sandfly Fever Sicilian Virus (SFSV) and Utique virus (UTIV). This study provides more evidence that the abundance of P. perfiliewi is associated with the development of irrigation in arid bio-geographical areas of Central Tunisia which may have led to the emergence of phleboviruses. We report the first detection of TOSV from sand flies collected from Central Tunisia. Copyright © 2016 Elsevier B.V. All rights reserved.

Biological, serological and molecular typing of potato virus Y (PVY) isolates from Tunisia.

PubMed

Tayahi, M; Gharsallah, C; Khamassy, N; Fakhfakh, H; Djilani-Khouadja, F

2016-10-17

In Tunisia, potato virus Y (PVY) currently presents a significant threat to potato production, reducing tuber yield and quality. Three hundred and eighty-five potato samples (six different cultivars) collected in autumn 2007 from nine regions in Tunisia were tested for PVY infection by DAS-ELISA. The virus was detected in all regions surveyed, with an average incidence of 80.26%. Subsequently, a panel of 82 Tunisian PVY isolates (PVY-TN) was subjected to systematic biological, serological and molecular typing using immunocapture reverse-transcription polymerase chain reaction and a series of PVY OC - and PVY N -specific monoclonal antibodies. Combined analyses revealed ~67% of PVY NTN variants of which 17 were sequenced in the 5'NTR-P1 region to assess the genetic diversity and phylogenetic relationship of PVY-TN against other worldwide PVY isolates. To investigate whether selective constraints could act on viral genomic RNA, synonymous and non-synonymous substitution rates and their ratio were analyzed. Averages of all pairwise comparisons obtained in the 5'NTR-P1 region allowed more synonymous changes, suggesting selective constraint acting in this region. Selective neutrality test was significantly negative, suggesting a rapid expansion of PVY isolates. Pairwise mismatch distribution gave a bimodal pattern and pointed to an eventually early evolution characterizing these sequences. Genetic haplotype network topology provided evidence of the existence of a distinct geographical structure. This is the first report of such genetic analyses conducted on PVY isolates from Tunisia.

Identifying tsunami deposits using shell taphonomy: Sur lagoon, Oman

NASA Astrophysics Data System (ADS)

Donato, S.; Reinhardt, E.; Rothaus, R.; Boyce, J.

2007-05-01

On November 28th, 1945 an 8.1 magnitude earthquake focused in the eastern portion of the Makran subduction zone (Arabian Sea) generated a powerful tsunami that destroyed many coastal villages in Pakistan and India. Reports indicate that the tsunami also caused significant damage in Muscat, Oman, although its effects elsewhere in Oman are unknown. A thick bivalve dominated shell horizon was discovered inside the Sur lagoon, which is located on the eastern promontory of Oman (200 km south of Muscat). This shell deposit is significant because it is laterally extensive (> 1 km2), extends deep within the lagoon (>2 km), ranges in thickness from 5 - 25 cm at the sample localities, contains numerous subtidal and offshore bivalve species, and articulated subtidal and offshore bivalve species are abundant. Although there is an absence of typical tsunami indicators such as allochthonous sediment in and around the lagoon, verbal accounts, cultural evidence recovered during coring, and the absence of strong storms during the past 100 years indicates that this shell unit was caused by the 1945 tsunami. In this setting, it would be advantageous to have another proxy for tsunami detection and risk prediction. The use of shell taphonomy is one of the potential indicators and here we present new evidence of its utility. We sampled this unit in eight locations, and compared the shell taphonomy to surface shell samples collected from beach and reworked horizons in the lagoon, and to shell samples from a known tsunami and corresponding storm/ballast deposit in Israel (Reinhardt et al., 2006). Taphonomic analysis yielded promising results, as the two tsunami horizons shared excellent agreement between the amount of fragmented shells, and the percentage of shells displaying angular breaks. Both of these categories were significantly different from the percentage of fragments and angular fragments recovered from the reworked, beach, and storm/ballast deposits, indicating different

Benthic foraminiferal and organic matter compounds as proxies of environmental quality in a tropical coastal lagoon: The Itaipu lagoon (Brazil).

PubMed

Raposo, Débora; Clemente, Iara; Figueiredo, Marcos; Vilar, Amanda; Lorini, Maria Lucia; Frontalini, Fabrizio; Martins, Virgínia; Belart, Pierre; Fontana, Luiz; Habib, Renan; Laut, Lazaro

2018-04-01

Lagoons in the southeast coast of Brazil have experienced eutrophication due to the exponential increase of human population and sewage discharges. Living benthic foraminifera have demonstrated to be good bioindicators of such impacts. This study aims to evaluate the organic matter accumulation effects on the foraminiferal distribution in the Itaipu lagoon (Brazil). On the basis of the biotic and abiotic analyses, three sectors are identified. The Sector I, an inner area, is characterized by high dissolved oxygen values and foraminiferal species with preference for marine conditions, demonstrating the sea influence. The Sector II, in the mangrove margins, is associated to sandy sediment and biopolymers and mainly represented by euryhaline species. The Sector III is marked by low density or absence of living foraminifera and corresponds to a low quality organic matter enriched area (North, Southwest and Centre). Copyright © 2018 Elsevier Ltd. All rights reserved.

Type-Specific Human Papillomavirus Distribution in Invasive Squamous Cervical Carcinomas in Tunisia and Vaccine Impact.

PubMed

Ennaifer, Emna; Salhi, Faten; Laassili, Thalja; Fehri, Emna; Ben Alaya, Nissaf; Guizani, Ikram; Boubaker, Samir

2015-01-01

High risk human papillomaviruses (HPVs) are the leading cause of cervical cancer (CC) and Pap smear screening has not been successful in preventing CC in Tunisia. HPV vaccination that targets HPV16 and 18 offers a new efficient prevention tool. Identification of HPV types in CC is thus essential to determine the impact of HPV vaccine implementation. The aim of this study is to provide specific data from Tunisia. A total of 89 histological confirmed paraffin embedded samples isolated from patients with CC diagnosed between 2001 and 2011 were collected from five medical centres from Northern and Southern Tunisia. HPV DNA was detected using a nested PCR (MY09/MY11-GP5+/GP6+) and genotyping was assessed using a reverse blot line hybridisation assay that enables the detection of 32 HPV types. HPV DNA was detected in all samples. Twelve high risk types were detected; HPV16 and/or 18 were predominant, accounting together for 92.1% of all the CC cases (HPV16: 83.1%). Single infections accounted for 48.8% of the cases and were mostly linked to HPV 16 (32.6%) and less frequently to HPV 18 (2.4%). The other high risk HPV single infections were linked to HPV 35 (4.6%), 45 (4.6%), 58 (2.3%) and 59 (2.3%). Multiple infections with mixing of 2 to 4 genotypes predominately featrued HPV16 and/or 18 with HPV 35 and 45 (96.6 %) and less frequently with HPV 59, 40, 66, 73 and 58. There was no statistically significant variation in the relative distribution of HPV types with age. These results strongly indicate that prophylactic HPV vaccines can have a major impact in preventing CC in Tunisia.

Nasopharyngeal carcinoma incidence in North Tunisia: negative trends in adults but not adolescents, 1994-2006.

PubMed

Wided, Ben Ayoub Hizem; Hamouda, Boussen; Hamadi, Hsairi; Mansour, Ben Abdallah

2015-01-01

Nasopharyngeal carcinoma (NPC) is the second most common neoplasm of head and neck in Tunisia. The distribution is bimodal with a first period occurrence between 15 and 20 years old and a second peak at around 50 years of age. Undifferentiated carcinoma of nasopharynx type III (UCNT) is the predominant histological type (93.4%). Data of cancer registry of North Tunisia confirmed that it is an intermediate risk area for NPC with overall ASRs of 3.6 and 1.6/100,000 respectively in males and females. This study aimed to present the evolution of incidence rate of nasopharyngeal carcinoma over a period of 12 years (1994-2006). Data of cancer registry of North Tunisia (NTCR), covering half of the Tunisian population, were used to determine evolution of NPC incidence, calculated by 5 year periods. The estimated annual percentage change (EAPC) was used as an estimate of the trend. To best summarize the behavior or the data trend across years, we used a join-point regression program. Between 1994 and 2006, we observed negative annual average change of standardized incidence in men and women (-3.3% and -2.7%) also for the standardized incidences which showed a rather important decline (26.4% in males and 22.3% in females). The truncated age standardized incidence rate of NPC in adults aged of 30 years old and more (N=1209) decreased by -0.4% per year from 1994 to 2006 over time in north Tunisia dropping from 6.09 to 4.14 person-years. However, the rate was relatively stable during this period among youths aged 0-29 years (N=233) in both sexes. NPC demonstrated a favorable evolution from 1994-2006 probably due to a improvement in socioeconomic conditions.

Emerging vector-borne diseases in dromedaries in Tunisia: West Nile, bluetongue, epizootic haemorrhagic disease and Rift Valley fever.

PubMed

Hassine, Thameur B; Amdouni, Jihane; Monaco, Federica; Savini, Giovanni; Sghaier, Soufien; Selimen, Imed B; Chandoul, Walid; Hamida, Khaled B; Hammami, Salah

2017-03-31

A total of 118 sera were collected during 2016 from two groups of dromedaries from Kebili and Medenine governorates in the south of Tunisia. The aim of this study was to provide the first serological investigation of four emerging vector-borne diseases in two groups of dromedaries in Tunisia. Sera were tested by ELISA and serum neutralisation test to identify West Nile virus (WNV), bluetongue virus (BTV), epizootic haemorrhagic disease virus (EHDV) and Rift Valley fever virus (RVFV). In the first group, the seroprevalence for BTV was 4.6%, while in the second group, it was 25.8% for WNV and 9.7% for BTV. Only serotype 1 was detected for BTV in the two groups. No evidence for circulation of RVF and EHD viruses was revealed. Results indicated that dromedaries can be infected with BTV and WNV, suggesting that this species might play a significant role in the epizootiology of these viral diseases in Tunisia and neighbouring countries.

Epidemiology and medical cost of hospitalization due to rotavirus gastroenteritis among children under 5 years of age in the central-east of Tunisia.

PubMed

Soltani, M S; Salah, A Ben; Bouanene, I; Trabelsi, A; Sfar, M T; Harbi, A; Gueddiche, M N; Farhat, E Ben

2015-09-28

Data on the economic burden of rotavirus infection in Tunisia are needed to inform the decision to include rotavirus in routine childhood immunizations. This study aimed to describe the epidemiological profile of rotavirus disease in central-east Tunisia and to estimate its hospital cost. In the first stage - the prospective collection of epidemiological data - we enrolled all patients < 5 years old who were hospitalized for acute diarrhoea at 5 university paediatric departments in central-east Tunisia during the period 2009-2011. Rotavirus was responsible for 65 (23.3%) of the 279 cases enrolled. In the second stage, cost data were collected retrospectively using an activity-based costing method from the medical records of the children who were positively diagnosed with rotavirus. The average cost of care per child was TD 433 (SD 134). This is a significant economic burden in Tunisia, where a safe and effective vaccine is available but not yet introduced to the immunization schedule.

Liquid and atmospheric ammonia concentrations from a dairy lagoon during an aeration experiment

NASA Astrophysics Data System (ADS)

Rumburg, Brian; Neger, Manjit; Mount, George H.; Yonge, David; Filipy, Jenny; Swain, John; Kincaid, Ron; Johnson, Kristen

Ammonia emissions from agriculture are an environmental and human health concern, and there is increasing pressure to reduce emissions. Animal agriculture is the largest global source of ammonia emissions and on a per cow basis dairy operations are the largest emitters. The storage and disposal of the dairy waste is one area where emissions can be reduced, aerobic biological treatment of wastewater being a common and effective way of reducing ammonia emissions. An aeration experiment in a dairy lagoon with two commercial aerators was performed for 1 month. Liquid concentrations of ammonia, total nitrogen, nitrite and nitrate were monitored before, during and after the experiment and atmospheric ammonia was measured downwind of the lagoon using a short-path differential optical absorption spectroscopy (DOAS) instrument with 1 ppbv sensitivity. No changes in either liquid or atmospheric ammonia concentrations were detected throughout the experiment, and neither dissolved oxygen, nitrite nor nitrate could be detected in the lagoon at any time. The average ammonia concentration at 10 sampling sites in the lagoon at a depth of 0.15 m was 650 mg l -1 and at 0.90 m it was 700 mg l -1 NH 3-N. The average atmospheric ammonia concentration 50 m downwind was about 300 ppbv. The 0.90 m depth total nitrogen concentrations and total and volatile solids concentrations decreased during the experiment due to some mixing of the lagoon but the 0.15 m depth concentrations did not decrease indicating that the aerators were not strong enough to mix the sludge off the bottom into the whole water column.

Genetic variation in Tunisia in the context of human diversity worldwide.

PubMed

Cherni, Lotfi; Pakstis, Andrew J; Boussetta, Sami; Elkamel, Sarra; Frigi, Sabeh; Khodjet-El-Khil, Houssein; Barton, Alison; Haigh, Eva; Speed, William C; Ben Ammar Elgaaied, Amel; Kidd, Judith R; Kidd, Kenneth K

2016-09-01

North Africa has a complex demographic history of migrations from within Africa, Europe, and the Middle East. However, population genetic studies, especially for autosomal genetic markers, are few relative to other world regions. We examined autosomal markers for eight Tunisian and Libyan populations in order to place them in a global context. Data were collected by TaqMan on 399 autosomal single nucleotide polymorphisms on 331 individuals from Tunisia and Libya. These data were combined with data on the same SNPs previously typed on 2585 individuals from 57 populations from around the world. Where meaningful, close by SNPs were combined into multiallelic haplotypes. Data were evaluated by clustering, principal components, and population tree analyses. For a subset of 102 SNPs, data from the literature on seven additional North African populations were included in analyses. Average heterozygosity of the North African populations is high relative to our global samples, consistent with a complex demographic history. The Tunisian and Libyan samples form a discrete cluster in the global and regional views and can be separated from sub-Sahara, Middle East, and Europe. Within Tunisia the Nebeur and Smar are outlier groups. Across North Africa, pervasive East-West geographical patterns were not found. Known historical migrations and invasions did not displace or homogenize the genetic variation in the region but rather enriched it. Even a small region like Tunisia contains considerable genetic diversity. Future studies across North Africa have the potential to increase our understanding of the historical demographic factors influencing the region. Am J Phys Anthropol 161:62-71, 2016. © 2016 The Authors American Journal of Physical Anthropology Published by Wiley Periodicals, Inc. © 2016 The Authors American Journal of Physical Anthropology Published by Wiley Periodicals, Inc.

Evaluation of Puccinia carduorum for biological control of Carduus pycnocephalus in Tunisia

USDA-ARS?s Scientific Manuscript database

The rust fungus Puccinia carduorum is a candidate for biological control of Carduus pycnocephalus in the USA. In Tunisia, rusted C. pycnocephalus has been found in many fields during surveys conducted in the north of the country. The pathogenicity of Puccinia carduorum was evaluated under greenhou...

State-of-the-lagoon reports as vehicles of cross-disciplinary integration.

PubMed

Zaucha, Jacek; Davoudi, Simin; Slob, Adriaan; Bouma, Geiske; van Meerkerk, Ingmar; Oen, Amy Mp; Breedveld, Gijs D

2016-10-01

An integrative approach across disciplines is needed for sustainable lagoon and estuary management as identified by integrated coastal zone management. The ARCH research project (Architecture and roadmap to manage multiple pressures on lagoons) has taken initial steps to overcome the boundaries between disciplines and focus on cross-disciplinary integration by addressing the driving forces, challenges, and problems at various case study sites. A model was developed as a boundary-spanning activity to produce joint knowledge and understanding. The backbone of the model is formed by the interaction between the natural and human systems, including economy and governance-based subsystems. The model was used to create state-of-the-lagoon reports for 10 case study sites (lagoons and estuarine coastal areas), with a geographical distribution covering all major seas surrounding Europe. The reports functioned as boundary objects to build joint knowledge. The experiences related to the framing of the model and its subsequent implementation at the case study sites have resulted in key recommendations on how to address the challenges of cross-disciplinary work required for the proper management of complex social-ecological systems such as lagoons, estuarine areas, and other land-sea regions. Cross-disciplinary integration is initially resource intensive and time consuming; one should set aside the required resources and invest efforts at the forefront. It is crucial to create engagement among the group of researchers by focusing on a joint, appealing overall concept that will stimulate cross-sectoral thinking and focusing on the identified problems as a link between collected evidence and future management needs. Different methods for collecting evidence should be applied including both quantitative (jointly agreed indicators) and qualitative (narratives) information. Cross-disciplinary integration is facilitated by functional boundary objects. Integration offers important

Diazotroph community succession during the VAHINE mesocosms experiment (New Caledonia Lagoon)

NASA Astrophysics Data System (ADS)

Turk-Kubo, K. A.; Frank, I. E.; Hogan, M. E.; Desnues, A.; Bonnet, S.; Zehr, J. P.

2015-06-01

The VAHINE mesocosm experiment, conducted in the low-nutrient low-chlorophyll waters of the Noumea Lagoon (coastal New Caledonia) was designed to trace the incorporation of nitrogen (N) fixed by diazotrophs into the food web, using large volume (50 m3) mesocosms. This experiment provided a unique opportunity to study the succession of different N2-fixing microorganisms (diazotrophs) and calculate in situ net growth and loss rates in response to fertilization with dissolved inorganic phosphate (DIP) over a 23 day period, using quantitative polymerase chain reaction (qPCR) assays. Inside the mesocosms, the diazotroph community assemblage was dominated by the heterocyst-forming Richelia associated with Rhizosolenia (Het-1) in the first half of the experiment, and unicellularcyanobacterial Group C (UCYN-C) became the dominant diazotroph in the second half of the experiment. Decreasing DIP concentrations following the fertilization event and increasing temperatures were significantly correlated with increasing abundances of UCYN-C. Maximum net growth rates for UCYN-C were calculated to be between 1.23 ± 0.07 and 2.16 ± 0.07 d-1 which are among the highest growth rates reported for diazotrophs. Outside the mesocosms in the Noumea Lagoon, UCYN-C abundances remained low, despite increasing temperatures, suggesting that the microbial community response to the DIP fertilization created conditions favorable for UCYN-C growth inside the mesocosms. Maximum net growth and loss rates for nine diazotroph phylotypes throughout the 23 day experiment were variable between mesocosms, and repeated fluctuations between periods of net growth and loss were commonly observed. The field population of diazotrophs in the Noumea Lagoon, was dominated by Het-1 over the course of the study period. However, eight additional diazotroph phylotypes were present in the lagoon at lower abundances, indicating a diverse field population of diazotrophs. Two ecotypes of the Braarudosphaera bigelowii

Macrobenthic molluscs from a marine - lagoonal environmental transition in Lesvos Island (Greece).

PubMed

Evagelopoulos, Athanasios; Koutsoubas, Drosos; Gerovasileiou, Vasilis; Katsiaras, Nikolaos

2016-01-01

This paper describes an occurence dataset, also including numerical abundance and biomass data, pertaining to the macrobenthic molluscan assemblages from a marine - lagoonal environmental transition. The study system was the soft-substrate benthoscape of the area of the Kalloni solar saltworks (Lesvos Island, Greece). Specifically, the study area extended from the infralittoral zone of the inner Kalloni Gulf (marine habitat) to the bottoms of the first two evaporation ponds of the Kalloni solar saltworks (lagoonal habitat). Bottom sediment samples (3 replicates) were collected with a Van Veen grab sampler (0.1 m 2 ) at four sampling sites, along a 1.5 km long line transect that spanned the marine - lagoonal environmental transition. A total of four surveys were carried out seasonally in 2004.  A total of 39,345 molluscan individuals were sorted out of the sediment samples and were identified to 71 species, belonging to the Gastropoda (36), Bivalvia (34) and Scaphopoda (1) classes. Numerical abundance and wet biomass (with shells) data are included in the dataset. The dataset described in the present paper partially fills a significant gap in the scientific literature: Because ecological research of coastal lagoons has seldom explicitly considered the marine - lagoonal habitats interface, there are no openly accessible datasets pertaining to the particular structural component of the transitional waters benthoscapes of the Mediterranean Sea. Such datasets could prove valuable in the research of the structure and functioning of transitional waters benthoscapes. The present dataset is available as a supplementary file (Suppl. material 1) and can also be accessed at http://ipt.medobis.eu/resource?r=kalloni_saltworks_phd.

Identifying nutrient sources to three lagoons at Ofu and Olosega, American Samoa using δ15N of benthic macroalgae

USGS Publications Warehouse

Garrison, Virginia H.; Kroeger, Kevin D.; Fenner, Douglas; Craig, Peter

2007-01-01

Degradation of nearshore habitats is a serious problem in some areas of American Samoa, such as in Pago Pago Harbor on Tutuila Island, and is a smaller but chronic problem in other areas. Sedimentation, pollution, nutrient enrichment from surface runoff or groundwater, and trampling are the major factors causing the changes (Peshut and Brooks, 2005). On the outer islands of Ofu and Olosega (Manu’a Islands; Fig. 1), there is an interesting contrast between relatively pristine lagoon habitats not far from comparatively degraded lagoon habitats. To’aga lagoon on the southeast side of Ofu Island (Fig. 1) has clear waters, a high diversity of corals and fishes, no human habitations, and an undeveloped watershed with no streams. To’aga lagoon is within the boundaries of the National Park of American Samoa and is the site of long-term research on coral reef resilience and global climate change. Only 3 km to the east of To’aga is a degraded lagoon that fronts Olosega Village. The Olosega lagoon is similar in size but has significantly less live coral than To’aga, and blooms of filamentous algae have been reported to cover the Olosega lagoon/reef flat bottom (unpublished data, PC; Fig. 2). The islands are influenced by the same regional-scale and biogeochemical regimes, and both islands are remnants of a volcanic caldera (Craig, 2005). Thus, local factors operating on the scale of a kilometer or less are thought to be driving the differences observed between lagoons. Land disturbance is limited to a road linking the villages, the clearing of vegetation for buildings, and two village dump sites located on the narrow strip of land between the steep slopes of the islands and the shoreline; there is no industry or associated pollution on either island. Cesspools are used for sewage disposal. Nutrient enrichment (from cesspools) of groundwater and the lagoon, as well as trampling during gleaning of reef organisms, are possible factors affecting the spatial relief

Diet, living conditions and nasopharyngeal carcinoma in Tunisia--a case-control study.

PubMed

Jeannel, D; Hubert, A; de Vathaire, F; Ellouz, R; Camoun, M; Ben Salem, M; Sancho-Garnier, H; de-Thé, G

1990-09-15

We conducted a case-control study of nasopharyngeal carcinoma (NPC) in Tunisia, on diet, dietary patterns and life style, the characteristics of which had been defined by an anthropological study. Eighty incident cases, diagnosed in Tunisia between November 1986 and November 1987, were each matched for sex, age and place of residence to 2 controls. The subjects were asked for dietary data referring to the year preceding the diagnosis of NPC and, with help of their families, during childhood and after weaning. After adjustment for an empirical living conditions score, the following food items were found to be associated with an increased risk for NPC: preserved spiced meat (quaddid), basic stewing preparation (mixture of red and black pepper, garlic, oil, caraway and coriander), and harissa (red pepper, olive oil, garlic, caraway, salt) taken with bread as a snack during childhood and youth. Moreover, subjects who had been directly weaned from mother's milk on to an adult diet were found to be at higher risk for NPC.

Methane in Sediments From Three Tropical, Coastal Lagoons on the Yucatan Peninsula, Mexico

NASA Astrophysics Data System (ADS)

Young, B.; Paytan, A.; Miller, L.; Herrera-Silveira, J.

2002-12-01

Tropical wetlands are significant sources of methane (CH4) to the atmosphere, and the majority of research on methane flux and cycling in the tropics has been conducted in fresh-water wetlands and lakes. However, several previous studies have shown that tropical coastal ecosystems can produce significant methane flux to the atmosphere despite the presence of moderate to marine salinities. Information regarding methane cycling within the sediments is crucial to understanding how natural and anthropogenic changes may influence these systems. We measured methane concentrations in sediments from two tropical coastal lagoons during different seasons, as well as in a third, heavily polluted, lagoon (Terminos) during the rainy season. These three lagoons, Celestun, Chelem, and Terminos, have similar vegetation, seasonal temperature and rainfall patterns, and substrate geology, but very different levels of ground water discharge and pollution. Methane concentrations in Celestun and Terminos lagoon showed high spatial variability(> 0.001 to 5 mmol kg-1 wet sediment), while sediments in Chelem Lagoon, which has near marine salinities and little sewage discharge, showed much lower variability of methane concentrations. Methane concentrations in Celestun sediments displayed two predominant patterns: some profiles contained a peak in methane concentration (1 to 2 mmole methane kg-1 wet sediment) between 5 and 15 cm below the surface while the other sediment profiles instead displayed a steady or monotonic increase in methane concentration with depth to approximately 0.025-0.080 mmol kg-1 at 10-15cm below surface followed by stable methane concentrations to the bottom of the cores (20-45 cm below the surface). A subsurface peak in methane concentrations was also found in some locations in Chelem, however, the concentrations were much lower than those measured in Celestun. Previous studies have shown that sewage pollution may drastically increase methane production in tropical

Atoll-phosphate genesis: Role of lagoonal biomass and possible role of endo-upwelling processes in phosphate concentration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Trichet, J.; Rougerie, F.

1990-06-01

Sedimentological and hydrogeological data in Niau, a closed atoll in French Polynesia where P-concentration has been measured, suggest the role played by lagoonal organic matter in P-accumulation and the possible role of endo-upwelling processes in P-input in the system. A 15 m deep core through the lagoonal deposits shows the succession of organic-rich strata in which the P-content can reach up to 1.3% P{sub 2}O{sub 5}. Such a pattern suggests that, whatever the source of P within the lagoon (lagoonal water, bird guano, or endo-upwelled solutions, see below), this element is likely to be incorporated in quantitatively important lagoonal biomassmore » whose decay releases phosphorus back to the sediment. An example of such biomass and organic matter is given by the large amounts of cyano-bacterial organic matter that are present in the lagoon of Niau. A source for island phosphate has recently been proposed to be relatively deep seawater, which would be endo-upwelled from depths of hundreds of meters ({approximately}500 m, where P content is approximately 1.5 mmol.m{sup {minus}3} PO{sub 4}-P) through the permeable reef-body up to its surface (i.e., to its lagoonal waters, where P content reaches 5 mmol.m{sup {minus}3} in Niau atoll). The energy necessary for the transport of such solutions would be geothermal (at the bottom of the water column, i.e., close to the volcanic substrate of the reef body) and solar at its top through evaporation.« less

Tet and sul antibiotic resistance genes in livestock lagoons of various operation type, configuration, and antibiotic occurrence

USGS Publications Warehouse

McKinney, C.W.; Loftin, K.A.; Meyer, M.T.; Davis, J.G.; Pruden, A.

2010-01-01

Although livestock operations are known to harbor elevated levels of antibiotic resistant bacteria, few studies have examined the potential of livestock waste lagoons to reduce antibiotic resistance genes (ARGs). The purpose of this study was to determine the prevalence and examine the behavior of tetracycline [tet(O) and tet(W)] and sulfonamide [sul(I) and su/(II)] ARGsin a broad cross-section of livestock lagoons within the same semiarid western watershed. ARGs were monitored for one year in the water and the settled solids of eight lagoon systems by quantitative polymerase chain reaction. In addition, antibiotic residues and various bulk water quality constituents were analyzed. It was found that the lagoons of the chicken layer operation had the lowest concentrations of both tet and sul ARGs and low total antibiotic concentrations, whereas su ARGs were highest in the swine lagoons, which generally corresponded to the highest total antibiotic concentrations. A marginal benefit of organic and small dairy operations also was observed compared to conventional and large dairies, respectively. In all lagoons, su ARGs were observed to be generally more recalcitrant than tet ARGs. Also, positive correlations of various bulk water quality constituents were identified with tet ARGs but not sul ARGs. Significant positive correlations were identified between several metals and tet ARGs, but Pearson's correlation coefficients were mostly lower than those determined between antibiotic residues and ARGs. This study represents a quantitative characterization of ARGs in lagoons across a variety of livestock operations and provides insight into potential options for managing antibiotic resistance emanating from agricultural activities. ?? 2010 American Chemical Society.

Environmental changes in the Moulay Bousselham lagoon (Morocco) during the last 7 000 years using a multiproxy approach

NASA Astrophysics Data System (ADS)

Zourarah, Bendahhou; Maanan, Mohamed; Conceição Freitas, Maria; Leroy, Suzanne; Andrade, César; Cearreta, Alejandro; Cruces, Anabela

2016-04-01

The aim of this research is to reconstruct Holocene environmental changes in Moulay Bousselham lagoon using a multi-proxy approach to the study of sediments of two short cores: biological (e.g., pollen, foraminifera and diatoms), physicochemical (isotopes, chemical composition) and sedimentary (grain size, clay minerals). The research highlights the role of climatic variations and human interference in the evolution of this lagoon. The results show that at the beginning of the Holocene this area corresponded to a wide coastal bay, including the surface of Moulay Bousselham present-day lagoon and Merja Ras Ed-Dora. The dating's obtained in the base of the sediment cores range from 6790-6640 BP (end of the Atlantic and early Sub-boreal). Sand predominates in this section of the cores, with low content of organic matter and high content of bioclasts. Ammonia tepida is the predominant species but Haynesina germânica, Quinqueloculina semínula,Cibicides lobatulus,Criboelphidium oceanensis and Miliolinella sobrotunda are also presente. At the base, foraminifera assemblages show a relative abundance of Planorbulina mediterranensis, Rosalina anomala, Rosalina irregularis, Miliolinella subrotunda and Cibicides lobatulus. These are typical of a shallow environment with normal marine salinity. During the sub-boreal period (6640-4520 BP), a sandy barrier developed and the lagoon evolved to a brackish lagoon with low salinity. Sedimentation is homogeneous, the content of silt and clay is high (90%), calcium carbonate content is usually lower than 20% and the organic material exhibited the highest values (> 10%). Ammonia tepida is also the dominant species but C. oceanensis and H. germanica are secondary. The lagoon was closed in drier conditions and has gradually filled by sediments coming from the watershed, represented by an illite-chlorite association. The lagoon evolved to a sabkha. We must emphasize the role of deforestation caused by the Romans (2100 BP) in that period

Serological and molecular detection of Toscana and other Phleboviruses in patients and sandflies in Tunisia.

PubMed

Fezaa, Ons; M'ghirbi, Youmna; Savellini, Gianni Gori; Ammari, Lamia; Hogga, Nahed; Triki, Henda; Cusi, Maria Grazia; Bouattour, Ali

2014-11-15

Our aim is to detect the infection by Toscana virus (TOSV) and other Phleboviruses in the sera and cerebro-spinal fluid (CSF) of patients with meningitis in Tunisia. We examined various species of phlebotomus present in Tunisia to determine whether or not a direct relationship exists between cases of meningitis and the viruses circulating in the insect vectors. Patients with the meningeal syndrome were tested for anti-TOSV IgM and IgG using an indirect Enzyme-Linked Immunosorbent Assay (ELISA) and for the presence of TOSV and other Phleboviruses using a RT-PCR test. Of 263 patients were tested using ELISA of which 12.16% (n = 32/263) were IgM positive for anti TOSV. Of these 32 patients, 78% (n = 25/32) were IgG positive. 12.86% (n = 18/140) of the CSF samples tested by RT-PCR were positive for the Toscana virus. This study confirms, for the first time, that TOSV is involved in a neurological disorder in North Africa. The incidence of this involvement in Tunisia conforms with observations made in other Mediterranean countries. Moreover, for the first time, a molecular approach was used to detect SFSV in a Tunisian patient displaying neurological symptoms.

Effects of Fusarium culmorum and water stress on durum wheat in Tunisia

USDA-ARS?s Scientific Manuscript database

The effects of water stress on Fusarium foot and root rot in durum wheat were investigated in growth chamber, greenhouse and field tests in Tunisia. In the seedling stage, emergence of six durum wheat cultivars in the growth chamber was significantly reduced by inoculation with Fusarium culmorum and...

Scope, Relevance and Challenges of Financing Higher Education: The Case of Tunisia

ERIC Educational Resources Information Center

Abdessalem, Tahar

2011-01-01

Like other developing countries, Tunisia has allocated increasing levels of resources to education, particularly higher education, over the past few decades, mainly through public funding. From 2005 to 2008, public expenditure on education amounted to around 7.4% of GDP, with 2% allocated to higher education. Recently, however, budgetary…

Alterations in macroinvertebrate spatial patterns in coastal lagoons: Óbidos (NW coast of Portugal) 1984 versus 2002

NASA Astrophysics Data System (ADS)

Rodrigues, Ana Maria; Quintino, Victor; Pereira, Fábio; Freitas, Rosa

2012-09-01

The macroinvertebrate spatial distribution patterns in the Lagoon of Óbidos were studied in 1984 and revisited in 2002. The overall surficial sediments and benthic community patterns show consistent similarities in the two sampling periods, but also important differences. The lagoon is relatively shallow, with about 1/3 of the area covered with extensive intertidal sand banks. These are interrupted by a navigation channel bordering the northern margin (1984) and, following dredging operations, a new navigation channel was opened along the southern margin (2002). The sediments in the navigation channels were coarser and with less percentage of fines in 2002 than in 1984. Arthropods dominated the species richness and abundance in 1984, but were much less important in 2002, when the community was dominated by molluscs and annelids, both in species numbers as well as in abundance. In 1984, the structure of the macrofauna communities closely followed a general model proposed for Atlantic and Mediterranean lagoons, with the marine, the transition and the lagoon communities occupying very well defined areas. This gradient was in accordance with an increase in the fines and organic matter content directed inwards allowing for the coexistence of several characteristic lagoon species with others characteristic of organic enriched sediments. In 2002 this spatial pattern is still recognized but the marine and the transition communities are spatially mixed, occupying both the entrance region and the navigation channels, whereas the characteristic lagoon community identified in 1984 was only recognized in a group of sites located along the southern margin in 2002. Several species show very important changes in their distribution extent in the lagoon system. These changes essentially show a generalized inward expansion of the distribution range of the marine species, in agreement with a larger influence of marine conditions toward the inner areas of the lagoon. This study shows

The structure and productivity of the Thalassia testudinum community in Bon Accord Lagoon, Tobago.

PubMed

Juman, Rahanna A

2005-05-01

The Thalassia testudinum dominated seagrass community in the Buccoo Reef/ Bon Accord Lagoon Marine Park, measures 0.5 km(2) and is part of a contiguous coral reef, seagrass bed and mangrove swamp system in southwest Tobago. 7 testudinum coverage, productivity and percent turnover rates were measured from February 1998 to February 1999 at four sample locations, while total T. testudinum biomass was measured at two locations in the lagoon from 1992-2002. Productivity and turnover rates varied spatially and seasonally. They were higher in the back-reef area than in the mangrove-fringed lagoon, and were lowest at locations near to a sewage outfall. 7 testudinum coverage ranged from 6.6% in the lagoon to 68.5% in the back-reef area while productivity ranged from 3.9 to 4.9 g dry wt m(-2) d(-1) . Productivity and percentage turnover rates were higher in the dry season (January-June) than in the wet season (July-December). Productivity ranged from 3.0 in the wet season to 5.0 g dry wt m2 d-' in the dry season while percentage turnover rates ranged from 4.2% to 5.6%. Total Thalassia biomass and productivity in Bon Accord Lagoon were compared to six similar sites in the Caribbean that also participate in the Caribbean Coastal Marine Productivity Program (CARICOMP). This seagrass community is being negatively impacted by nutrient-enriched conditions.

Modelling the salinization of a coastal lagoon-aquifer system

NASA Astrophysics Data System (ADS)

Colombani, N.; Mastrocicco, M.

2017-08-01

In this study, a coastal area constituted by alternations of saline-brackish lagoons and freshwater bodies was studied and modelled to understand the hydrological processes occurring between the lagoons, the groundwater system of the Po River Delta (Italy) and the Adriatic Sea. The contribution of both evaporation and anthropogenic factors on groundwater salinization was assessed by means of soil, groundwater and surface water monitoring. Highresolution multi-level samplers were used to capture salinity gradients within the aquifer and surface water bodies. Data were employed to calibrate a density-dependent numerical transport model implemented with SEAWAT code along a transect perpendicular to the coast line. The results show that the lagoon is hydraulically well connected with the aquifer, which provides the major source of salinity because of the upcoming of paleo-seawater from the aquitard laying at the base of the unconfined aquifer. On the contrary, the seawater (diluted by the freshwater river outflow) creates only a limited saltwater wedge. The increase in groundwater salinity could be of serious concern, especially for the pinewood located in the dune near the coast, sensitive to salinity increases. This case study represents an interesting paradigm for other similar environmental setting, where the assumption of classical aquifer salinization from a saltwater wedge intruding from the sea is often not representative of the actual aquifer’s salinization mechanisms.

Seismic stratigraphy, tectonics and depositional history in the Halk el Menzel region, NE Tunisia

NASA Astrophysics Data System (ADS)

Sebei, Kawthar; Inoubli, Mohamed Hédi; Boussiga, Haïfa; Tlig, Said; Alouani, Rabah; Boujamaoui, Mustapha

2007-01-01

In the Halk el Menzel area, the proximal- to pelagic platform transition and related tectonic events during the Upper Cretaceous-Lower Miocene have not been taken into adequate consideration. The integrated interpretation of outcrop and subsurface data help define a seismic stratigraphic model and clarify the geodynamic evolution of the Halk el Menzel block. The sedimentary column comprises marls and limestones of the Campanian to Upper Eocene, overlain by Oligocene to Lower Miocene aged siliciclastics and carbonates. Well to well correlations show sedimentary sequences vary considerably in lithofacies and thicknesses over short distances with remarkable gaps. The comparison of sedimentary sequences cut by borehole and seismic stratigraphic modelling as well help define ten third order depositional sequences (S1-S10). Sequences S1 through S6 (Campanian-Paleocene) are mainly characterized by oblique to sigmoid configurations with prograding sedimentary structures, whereas, sequences S7-S10 (Ypresian to Middle Miocene) are organized in shallow water deposits with marked clinoform ramp geometry. Sedimentary discontinuities developed at sequence boundaries are thought to indicate widespread fall in relative sea level. Angular unconformities record a transpressive tectonic regime that operated from the Campanian to Upper Eocene. The geometry of sequences with reduced thicknesses, differential dipping of internal seismic reflections and associated normal faulting located westerly in the area, draw attention to a depositional sedimentary system developed on a gentle slope evolving from a tectonically driven steepening towards the Northwest. The seismic profiles help delimit normal faulting control environments of deposition. In contrast, reef build-ups in the Eastern parts occupy paleohighs NE-SW in strike with bordering Upper Maastrichtian-Ypresian seismic facies onlapping Upper Cretaceous counterparts. During the Middle-Upper Eocene, transpressive stress caused

Can conservation agriculture reduce the impact of soil erosion in northern Tunisia ?

NASA Astrophysics Data System (ADS)

Bahri, Haithem; Annabi, Mohamed; Chibani, Roukaya; Cheick M'Hamed, Hatem; Hermessi, Taoufik

2016-04-01

Mediterranean countries are prone to soil erosion, therefore Tunisia, with Mediterranean climate, is threatened by water erosion phenomena. In fact, 3 million ha of land is threatened by erosion, and 50% is seriously affected. Soils under conservation agriculture (CA) have high water infiltration capacities reducing significantly surface runoff and thus soil erosion. This improves the quality of surface water, reduces pollution from soil erosion, and enhances groundwater resources. CA is characterized by three interlinked principles, namely continuous minimum mechanical soil disturbance, permanent organic soil cover and diversification of crop species grown in sequence or associations. Soil aggregate stability was used as an indicator of soil susceptibility to water erosion. Since 1999, In Tunisia CA has been introduced in rainfed cereal areas in order to move towards more sustainable agricultural systems. CA areas increased from 52 ha in 1999 to 15000 ha in 2015. The objective of this paper is to study the effect of CA on soil erosion in northern Tunisia. Soil samples were collected at 10 cm of depth from 6 farmers' fields in northern Tunisia. Conventional tillage (CT), CA during less than 5 years (CA<5 years) and CA during more than 5 years (CA>5 years) have been practiced in each farmers field experiment of wheat crop. Soil aggregate stability was evaluated according to the method described by Le Bissonnais (1996), results were expressed as a mean weight diameter (MWD); higher values of MWD indicate higher aggregate stability. Total organic carbon (TOC) was determined using the wet oxidation method of Walkley-Black. A significant increase in SOC content was observed in CA>5years (1.64 %) compared to CT (0.97 %). This result highlights the importance of CA to improve soil fertility. For aggregate stability, a net increase was observed in CA compared to CT. After 5 years of CA the MWD was increased by 16% (MWD=1.8 mm for CT and MWD=2.1 mm for CA<5years). No

Albian salt-tectonics in Central Tunisia: Evidences for an Atlantic-type passive margin

NASA Astrophysics Data System (ADS)

Jaillard, Etienne; Bouillin, Jean-Pierre; Ouali, Jamel; Dumont, Thierry; Latil, Jean-Louis; Chihaoui, Abir

2017-11-01

Tunisia is part of the south-Tethyan margin, which comprises Triassic evaporites and a thick series of Jurassic and Cretaceous, mainly marine deposits, related to the Tethyan rifting evolution. A survey of various Cretaceous outcrops of central Tunisia (Kasserine-El Kef area), combined with literature descriptions, shows that the style of Albian deformation changes from the proximal (South) to the distal part (North) of the margin. The southern part is dominated by tilted blocks and growth faults, which evolve to the north to turtle-back and roll-over structures. Farther North, deformation is dominated by the extrusion of diapirs and salt walls. Such a distribution of deformation strongly suggests that the whole sedimentary cover glided northward on the Triassic evaporites during Albian times, as described for the Atlantic passive margin or for the Gulf of Mexico. Subsequently, these halokinetic structures have been folded during Alpine compressional tectonics.

Wind effects on prey availability: How northward migrating waders use brackish and hypersaline lagoons in the sivash, Ukraine

NASA Astrophysics Data System (ADS)

Verkuil, Yvonne; Koolhaas, Anita; Van Der Winden, Jan

Large numbers of waders migrating northward in spring use the Sivash, a large system of shallow, brackish and hypersaline lagoons in the Black Sea and Azov Sea region (Ukraine). The bottoms of these lagoons are often uncovered by the wind. Hence, for waders the time and space available for feeding depend on wind conditions. In hypersaline lagoons the benthic and pelagic fauna was very poor, consisting mainly of chironomid larvae (0.19 g AFDM·m -2) and brine shrimps Artemia salina, respectively. Brine shrimp abundance was correlated with salinity, wind force, wind direction and water depth. Dunlin Calidris alpina and curlew sandpiper Calidris ferruginea were the only species feeding on brine shrimp. As brine shrimp densities are higher in deeper water, smaller waders such as broad-billed sandpipers Limicola falcinellus are too short-legged to reach exploitable densities of brine shrimp. In brackish lagoons the benthic and pelagic fauna was rich, consisting of polychaetes, bivalves, gastropods, chironomid larvae, isopods and amphipods (8.9 to 30.5 g AFDM·m -2), but there were no brine shrimps. Prey biomass increased with the distance from the coast, being highest on the site that was most frequently inundated. Dunlin, broad-billed sandpiper and grey plover Pluvialis squatarola were the most abundant birds in the brackish lagoon. Due to the effects of wind-tides only a small area was usually available as a feeding site. Gammarus insensibilis was the alternative prey resource in the water layer, and their density varied with wind direction in the same way as brine shrimp. Curlew sandpipers and dunlins in the hypersaline lagoons and broad-billed sandpipers in the brackish lagoons often changed feeding sites, probably following the variation in prey availability. Only because of the large size and variety of lagoons are waders in the Sivash always able to find good feeding sites.

Physical Education in Tunisia: Teachers' Practical Epistemology, Students' Positioning and Gender Issues

ERIC Educational Resources Information Center

Amade-Escot, Chantal; Elandoulsi, Souha; Verscheure, Ingrid

2015-01-01

This paper explores gendered student learning in physical education (PE) viewed as a situated emerging process involving a triadic relationship between teacher, student(s) and forms of knowledge that are socioculturally bounded. It concerns gymnastic teaching and learning in Tunisia. It was conducted against the background of the Joint Action…

Molecular diagnosis of Rickettsia infection in patients from Tunisia.

PubMed

Khrouf, Fatma; Sellami, Hanene; Elleuch, Emna; Hattab, Zouhour; Ammari, Lamia; Khalfaoui, Moncef; Souissi, Jihed; Harrabi, Hejer; M'ghirbi, Youmna; Tiouiri, Hanene; Ben Jemaa, Mounir; Hammami, Adnene; Letaief, Amel; Bouattour, Ali; Znazen, Abir

2016-07-01

Diagnosis of rickettsioses had largely benefited from the development of molecular techniques. Unfortunately, in Tunisia, despite the large number of rickettsial cases registered every year, the Rickettsia species remain unidentified. In this study, we aimed to detect the Rickettsia species in clinical samples using molecular tests. A study was established to analyze skin biopsies, cutaneous swabs, and cerebrospinal fluid samples taken from clinically suspected patients to have rickettsial infection. Two molecular techniques were used to detect Rickettsia DNA: quantitative real time PCR (qPCR) and reverse line blot test (RLB). An analysis of the RLB hybridization assay results revealed the presence of Rickettsia DNA in skin biopsies (40.6%) and swabs (46.7%). Rickettsia conorii was the most prevalent identified species among tested samples. Other species of interest include Rickettsia typhi and Rickettsia massiliae. Using qPCR positivity rates in skin biopsies was 63.7% against 80% in swabs. R. conorii was the most frequently detected species, followed by R. typhi. The agreement between the two techniques was 68.6% (kappa=0.33). Molecular tests, especially using specific probes qPCR, allow for a rapid, better and confident diagnosis in clinical practice. They improve the survey of Mediterranean spotted fever which is considered to be the most important rickettsial infection in humans in Tunisia. Copyright © 2016 Elsevier GmbH. All rights reserved.

Potential changes in bacterial metabolism associated with increased water temperature and nutrient inputs in tropical humic lagoons.

PubMed

Scofield, Vinicius; Jacques, Saulo M S; Guimarães, Jean R D; Farjalla, Vinicius F

2015-01-01

Temperature and nutrient concentrations regulate aquatic bacterial metabolism. However, few studies have focused on the effect of the interaction between these factors on bacterial processes, and none have been performed in tropical aquatic ecosystems. We analyzed the main and interactive effects of changes in water temperature and N and P concentrations on bacterioplankton production (BP), bacterioplankton respiration (BR) and bacterial growth efficiency (BGE) in tropical coastal lagoons. We used a factorial design with three levels of water temperature (25, 30, and 35°C) and four levels of N and/or P additions (Control, N, P, and NP additions) in five tropical humic lagoons. When data for all lagoons were pooled together, a weak interaction was observed between the increase in water temperature and the addition of nutrients. Water temperature alone had the greatest impact on bacterial metabolism by increasing BR, decreasing BP, and decreasing BGE. An increase of 1°C lead to an increase of ~4% in BR, a decrease of ~0.9% in BP, and a decrease of ~4% in BGE. When data were analyzed separately, lagoons responded differently to nutrient additions depending on Dissolved Organic Carbon (DOC) concentration. Lagoons with lowest DOC concentrations showed the strongest responses to nutrient additions: BP increased in response to N, P, and their interaction, BR increased in response to N and the interaction between N and P, and BGE was negatively affected, mainly by the interaction between N and P additions. Lagoons with the highest DOC concentrations showed almost no significant relationship with nutrient additions. Taken together, these results show that different environmental drivers impact bacterial processes at different scales. Changes of bacterial metabolism related to the increase of water temperature are consistent between lagoons, therefore their consequences can be predicted at a regional scale, while the effect of nutrient inputs is specific to different

Potential changes in bacterial metabolism associated with increased water temperature and nutrient inputs in tropical humic lagoons

PubMed Central

Scofield, Vinicius; Jacques, Saulo M. S.; Guimarães, Jean R. D.; Farjalla, Vinicius F.

2015-01-01

Temperature and nutrient concentrations regulate aquatic bacterial metabolism. However, few studies have focused on the effect of the interaction between these factors on bacterial processes, and none have been performed in tropical aquatic ecosystems. We analyzed the main and interactive effects of changes in water temperature and N and P concentrations on bacterioplankton production (BP), bacterioplankton respiration (BR) and bacterial growth efficiency (BGE) in tropical coastal lagoons. We used a factorial design with three levels of water temperature (25, 30, and 35°C) and four levels of N and/or P additions (Control, N, P, and NP additions) in five tropical humic lagoons. When data for all lagoons were pooled together, a weak interaction was observed between the increase in water temperature and the addition of nutrients. Water temperature alone had the greatest impact on bacterial metabolism by increasing BR, decreasing BP, and decreasing BGE. An increase of 1°C lead to an increase of ~4% in BR, a decrease of ~0.9% in BP, and a decrease of ~4% in BGE. When data were analyzed separately, lagoons responded differently to nutrient additions depending on Dissolved Organic Carbon (DOC) concentration. Lagoons with lowest DOC concentrations showed the strongest responses to nutrient additions: BP increased in response to N, P, and their interaction, BR increased in response to N and the interaction between N and P, and BGE was negatively affected, mainly by the interaction between N and P additions. Lagoons with the highest DOC concentrations showed almost no significant relationship with nutrient additions. Taken together, these results show that different environmental drivers impact bacterial processes at different scales. Changes of bacterial metabolism related to the increase of water temperature are consistent between lagoons, therefore their consequences can be predicted at a regional scale, while the effect of nutrient inputs is specific to different

Diazotroph community succession during the VAHINE mesocosm experiment (New Caledonia lagoon)

NASA Astrophysics Data System (ADS)

Turk-Kubo, K. A.; Frank, I. E.; Hogan, M. E.; Desnues, A.; Bonnet, S.; Zehr, J. P.

2015-12-01

The VAHINE mesocosm experiment, conducted in the low-nutrient low-chlorophyll waters of the Noumea lagoon (coastal New Caledonia) was designed to trace the incorporation of nitrogen (N) fixed by diazotrophs into the food web, using large volume (50 m3) mesocosms. This experiment provided a unique opportunity to study the succession of different N2-fixing microorganisms (diazotrophs) and calculate in situ net growth and mortality rates in response to fertilization with dissolved inorganic phosphate (DIP) over a 23-day period, using quantitative polymerase chain reaction (qPCR) assays targeting widely distributed marine diazotroph lineages. Inside the mesocosms, the most abundant diazotroph was the heterocyst-forming Richelia associated with Rhizosolenia (Het-1) in the first half of the experiment, while unicellular cyanobacterial Group C (UCYN-C) became abundant during the second half of the experiment. Decreasing DIP concentrations following the fertilization event and increasing temperatures were significantly correlated with increasing abundances of UCYN-C. Maximum net growth rates for UCYN-C were calculated to range between 1.23 ± 0.07 and 2.16 ± 0.07 d-1 in the mesocosms, which are among the highest growth rates reported for diazotrophs. Outside the mesocosms in the New Caledonia lagoon, UCYN-C abundances remained low, despite increasing temperatures, suggesting that the microbial community response to the DIP fertilization created conditions favorable for UCYN-C growth inside the mesocosms. Diazotroph community composition analysis using PCR targeting a component of the nitrogenase gene (nifH) verified that diazotrophs targeted in qPCR assays were collectively among the major lineages in the lagoon and mesocosm samples, with the exception of Crocosphaera-like phylotypes, where sequence types not typically seen in the oligotrophic ocean grew in the mesocosms. Maximum net growth and mortality rates for nine diazotroph phylotypes throughout the 23-day

Water-quality monitoring and biological integrity assessment in the Indian River Lagoon, Florida: Status, trends, and loadings (1988--1994)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sigua, G.C.; Steward, J.S.; Tweedale, W.A.

2000-02-01

The Indian River Lagoon (IRL) system that extends from Ponce DeLeon inlet to Jupiter inlet is comprised of three interconnected estuarine lagoons: The Mosquito Lagoon (ML), the Banana River Lagoon (BRL), and the Indian River Lagoon. The declines in both the aerial coverage and species diversity of seagrass communities within the IRL system are believed to be due in part to continued degradation of water quality. Large inflows of phosphorus (P) and nitrogen (N)-laden storm-water from urban areas an agricultural land have been correlated with higher chlorophyll a production in the central, south central, and the south segments of themore » lagoon. In a system as large and complex as the lagoon, N and P limitations are potentially subject to significant spatial and temporal variability. Total Kjeidahl nitrogen (TN) was higher in the north and lower in the south. The reverse pattern was observed for total P (TP), i.e., lowest in the north and highest at the south ends of the IRL. This increased P concentration in the SIRL appears to have a significantly large effect on chlorophyll a production compared with the other segments, as indicated by stepwise regression statistics. This relationship can be expressed as follows: South IRL [chlorophyll a] = {minus}8.52 + 162.41 [orthophosphate] + 7.86 [total nitrogen] + 0.38 [turbidity]; R{sup 2} = 0.98**.« less

"Normal Planetary" Ne-Q in Chelyabinsk and Mars

NASA Astrophysics Data System (ADS)

Nyquist, L. E.; Park, J.; Nagao, K.; Haba, M. K.; Mikouchi, T.; Kusakabe, M.; Shih, C.-Y.; Herzog, G. F.

2015-07-01

Chelyabinsk contains “Q”-noble gases. Martian shergottite Dhofar 378 contains trapped 20Ne/22Ne = 7.3±0.3, derivable from Q-Ne with 20Ne/22Ne = 10.67 via fractionation by solar wind induced sputtering. Martian juvenile Ne is suggested to be Q-Ne.

Spatial variations in dietary organic matter sources modulate the size and condition of fish juveniles in temperate lagoon nursery sites

NASA Astrophysics Data System (ADS)

Escalas, Arthur; Ferraton, Franck; Paillon, Christelle; Vidy, Guy; Carcaillet, Frédérique; Salen-Picard, Chantal; Le Loc'h, François; Richard, Pierre; Darnaude, Audrey Michèle

2015-01-01

Effective conservation of marine fish stocks involves understanding the impact, on population dynamics, of intra-specific variation in nursery habitats use at the juvenile stage. In some regions, an important part of the catching effort is concentrated on a small number of marine species that colonize coastal lagoons during their first year of life. To determine the intra-specific variation in lagoon use by these fish and their potential demographic consequences, we studied diet spatiotemporal variations in the group 0 juveniles of a highly exploited sparid, the gilthead seabream (Sparus aurata L.), during their ∼6 months stay in a NW Mediterranean lagoon (N = 331, SL = 25-198 mm) and traced the origin of the organic matter in their food webs, at two lagoon sites with contrasted continental inputs. This showed that the origin (marine, lagoonal or continental) of the organic matter (OM) available in the water column and the sediment can vary substantially within the same lagoon, in line with local variations in the intensity of marine and continental inputs. The high trophic plasticity of S. aurata allows its juveniles to adapt to resulting differences in prey abundances at each site during their lagoon residency, thereby sustaining high growth irrespective of the area inhabited within the lagoon. However, continental POM incorporation by the juveniles through their diet (of 21-37% on average depending on the site) is proportional to its availability in the environment and could be responsible for the greater fish sizes (of 28 mm SL on average) and body weights (of 40.8 g on average) observed at the site under continental influence in the autumn, when the juveniles are ready to leave the lagoon. This suggests that continental inputs in particulate OM, when present, could significantly enhance fish growth within coastal lagoons, with important consequences on the local population dynamics of the fish species that use them as nurseries. As our results indicate that

Facultative Lagoons. Instructor's Guide. Biological Treatment Process Control.

ERIC Educational Resources Information Center

Andersen, Lorri

This instructor's guide contains materials needed to teach a two-lesson unit on the structure and components of facultative lagoons, the biological theory of their operation, and factors affecting their operation. Control testing recommendations, maintenance guidelines, and troubleshooting hints are also provided. These materials include: (1) an…

Effect of climate change and mollusc invasion on eutrophication and algae blooms in the lagoon ecosystems of the Baltic Sea

NASA Astrophysics Data System (ADS)

Aleksandrov, Sergei; Gorbunova, Julia; Rudinskaya, Lilia

2015-04-01

Coastal lagoons are most vulnerable to impacts of natural environmental and anthropogenic factors. The Curonian Lagoon and Vistula Lagoon are the largest coastal lagoons of the Baltic Sea, relating to the most highly productive water bodies of Europe. The Curonian Lagoon is choke mostly freshwater lagoon, while the Vistula Lagoon is restricted brackish water lagoon. In the last decades the nutrients loading changes, warming trend and biological invasions are observed. The researches (chlorophyll, primary production, nutrients, phytoplankton, benthos, etc) were carried out monthly since 1991 to 2014. The database includes 1600 stations in the Curonian Lagoon, 1650 stations in the Vistula Lagoon. Eutrophication and algae blooms are most important problems. Multiple reductions of nutrients loading from the watershed area in 1990s did not result in considerable improvement of the ecological situation in the lagoons. The Curonian Lagoon may be characterized as hypertrophic water body with "poor" water quality. Climate change in 1990s-2000s combined with other factors (freshwater, slow-flow exchange, high nutrients concentrations) creates conditions for Cyanobacteria "hyperblooms". Hyperbloom of Cyanophyta (average for the growing season Chl > 100 μg/l) were observed during 4 years in 1990s and 7 years in 2000s. The summer water temperature is the key environmental factor determining the seasonal and long-term variability of the primary production and algae blooms. Mean annual primary production in 2010-2014 (600 gC·m-2·year-1) is considerable higher, than in the middle of 1970s (300 gC·m-2·year-1). The local climate warming in the Baltic region caused ongoing eutrophication and harmful algae blooms in the Curonian Lagoon despite of significant reduction of nutrients loading in 1990s-2000s. Harmful algal blooms in July-October (chlorophyll to 700-3400 μg/l) result in deterioration of the water chemical parameters, death of fish in the coastal zone and pollution

Sterile Neutrino Searches in MiniBooNE and MicroBooNE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ignarra, Christina M.

Tension among recent short baseline neutrino experiments has pointed toward the possible need for the addition of one or more sterile (non-interacting) neutrino states into the existing neutrino oscillation framework. This thesis fi rst presents the motivation for sterile neutrino models by describing the short-baseline anomalies that can be addressed with them. This is followed by a discussion of the phenomenology of these models. The MiniBooNE experiment and results are then described in detail, particularly the most recent antineutrino analysis. This will be followed by a discussion of global fits to world data, including the anomalous data sets. Lastly, futuremore » experiments will be addressed, especially focusing on the MicroBooNE experiment and light collection studies. In particular, understanding the degradation source of TPB, designing the TPB-coated plates for MicroBooNE and developing lightguide collection systems will be discussed. We find an excess of events in the MiniBooNE antineutrino mode results consistent with the LSND anomaly, but one that has a di fferent energy dependence than the low-energy excess reported in neutrino mode. This disagreement creates tension within global fi ts which include up to three sterile neutrinos. The low-energy excess will be addressed by the MicroBooNE experiment, which is expected to start taking data in early 2015. Tension among existing experiments calls for additional, more decisive future experiments.« less

Eddy Covariance Measurements of Methane Emissions from a Dairy Farm Waste Lagoon

NASA Astrophysics Data System (ADS)

Sokol, A. B.; Lauvaux, T.; Richardson, S.; Hlywiak, J.; Davis, K. J.; Hristov, A. N.

2016-12-01

Livestock manure management in dairy operations is a known source of methane (CH4), a potent greenhouse gas. Anaerobic waste lagoons are a common manure management technique; thus, their associated CH4 emissions are relevant to national greenhouse gas inventories and local air quality. Our objective was to characterize the variability of summertime CH4 emissions from a lagoon at a dairy facility in central Pennsylvania. Continuous flux measurements were taken over two weeks in July using the eddy covariance method, which uses high-frequency gas concentration and three-dimensional wind speed measurements to calculate turbulent fluxes from a source area. After data filtration based on turbulence characteristics and source area, the average CH4 flux density from the lagoon was estimated to be 99 μmol m-2 s-1. This implies daily lagoon emissions of 881 kg CH4, corresponding to an average emission rate of 340 g CH4 per cow per day. We observed no apparent relationship between emissions and air temperature or relative humidity, though an extended measurement period is needed to better quantify the relationship that is expected to exist between air and/or slurry temperature and CH4 flux. Our measured per-area emission rate is toward the high end of the range of estimates found in the literature. These results contribute to greenhouse gas inventory development and could have important implications for emission mitigation strategies.

[Epidemiological, clinical and parasitological data about canine leishmaniasis in Tunisia].

PubMed

Bouratbine, A; Aoun, K; Gharbi, M; Haouas, N; Zaroui, J; Harrat, Z; Baba, H; Darghouth, M A

2005-12-01

Epidemiological, clinical and parasitological data concerning canine leishmaniasis were collected in two Tunisian populations of dogs, different in breed and life style: 23 rural dogs and 26 dogs of European breeds. All were symptomatic and lived in the north of Tunisia where human visceral and cutaneous leishmaniasis caused by Leishmania infantum are endemic. Leishmaniasis has been confirmed in all dogs by serology or/and by parasitic identification. Significant differences concerning age and symptoms suggest a higher susceptibility to infection in European imported breeds. In fact individuals of this population were significantly younger; 81% were less than 5 years old whereas 57% of the autochthonous rural dogs were more than 5 years old with 31% of them being older than 9 (p = 0.014). In spite of their young age, 75% of imported breeds presented an affection of their general state with more frequent cutaneous symptoms than the rural dogs (96% versus 69%, p = 0.02). Isoenzyme typing of 31 strains, obtained from the two populations, from different sites (blood, lymph nodes, spleen) has only identified the zymodeme Leishmania infantum MON-1. This stresses the need of more investigations to determine reservoirs of the other enzymatic variants identified in humans in Tunisia and Mediterranean basin.

WISE Catches the Lagoon Nebula in Center of Action

NASA Image and Video Library

2011-01-06

This colorful picture is a mosaic of Messier 8, or the Lagoon nebula, taken by NASA Wide-field Infrared Survey Explorer. This nebula is composed of clouds of gas and dust in which new stars are forming.

Celestial Navigation in the USA, Fiji, and Tunisia

NASA Astrophysics Data System (ADS)

Holbrook, Jarita C.

2015-05-01

Today there are many coastal communities that are home to navigators who use stars for position finding at night; I was, however, unaware of this fact when I began researching celestial navigation practices in 1997. My project focused on three communities: the Moce Islanders of Fiji, the Kerkennah Islanders in Tunisia, and the U.S. Navy officers and students at the United States Naval Academy, Annapolis, Maryland. My goal was to answer the question of why people continue to navigate by the stars, but also to understand the role of technology in their navigation practices. Using anthropology techniques of ethnography including participant observation, formal and informal interviews, audio and videotaping, I gathered data over five years at the three communities. I began by learning the details of how they use the stars for navigation. Next, I learned about who did the navigation and where they learned to navigate. I gathered opinions on various navigation aids and instruments, and opinions about the future of using the stars for navigation. I listened to the stories that they told about navigating. In the United States I worked in English, in Fiji, in Fijian and English, and in Tunisia, French and English. For the formal interviews I worked with translators. The navigators use stars for navigating today but the future of their techniques is not certain. Though practiced today, these celestial navigation traditions have undergone and continue to undergo changes. New navigational technologies are part of the stimulation for change, thus 'a meeting of different worlds' is symbolized by peoples encounters with these technologies.

Refugees in and out North Africa: a study of the Choucha refugee camp in Tunisia.

PubMed

Dourgnon, Paul; Kassar, Hassène

2014-08-01

In recent years, North African (NA) countries ceased to be emigration-only countries and are now on the verge of becoming immigration as well as transit countries for economic migrants and refugees. Contextual as well as structural long-term factors are driving these changes. The ongoing crises in Africa and the Middle East are prompting strong outflows of refugees, which are likely to induce NA countries to share some common public policy and public health concerns with European countries in a near future. This article highlights some aspects of these changes, from the study of the consequences of the 2011 Libyan crisis in Tunisia. It addresses individual trajectories and health concerns of refugees in and out North Africa from a study of the Choucha camp in Tunisia. The camp opened to immigrants from Libya during the 2011 crisis and accommodated the bulk of the refugees flow to Tunisia until July 2012. The study includes a monographic approach and a qualitative survey in the Choucha camp refugees. We describe the crisis history and the health response with a focus on the camp. We then address refugees' trajectories, and health needs and concerns from the interviews we collected in the camp in April 2012. © The Author 2014. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

Spatio-temporal evolution of shoreline changes along the coast between sousse- Monastir (Eastearn of Tunisia)

NASA Astrophysics Data System (ADS)

Fathallah, S.; Ben Amor, R.; Gueddari, M.

2009-04-01

Spatio-temporal evolution of shoreline Changes along the coast between Sousse-Monastir (Eastern of Tunisia). Safa Fathallah*, Rim Ben Amor and Moncef Gueddari Unit of Research of Geochemistry and Environmental Geology. Faculty of Science of Tunis, University of Tunis El Manar, 2092. (*) Corresponding author: safa_fathallah@yahoo.fr The coast of Sousse-Monastir in eastern of Tunisia, has undergone great changes, due to natural and anthropic factors. Increasing human use, the construction of two ports and coastal urbanization (hotels and industries) has accelerated the erosion process. The coastal defense structures (breakwaters and enrockment), built to protect the most eroded zone are efficient, but eroded zones appeared in the southern part of breakwaters. Recent and historic aerial photography was used to estimate, observe, and analyze past shoreline and bathymetric positions and trends involving shore evolution for Sousse-Monastir coast. All of the photographs were calibrated and mosaicked by Arc Map Gis 9.1, the years used are 1925, 1962, 1988, 1996, and 2001 for shoreline change analysis and 1884 and 2001 for bathymetric changes. The analyze of this photographs show that the zone located at the south of breakwater are mostly eroded with high speed process (2m/year). Another zone appears as eroded at the south part of Hamdoun River, with 1,5m/year erosion speed . Keywords: Shoreline evolution, defense structures, Sousse-Monastir coast, Tunisia.

Continuous opacity from Ne^-

NASA Astrophysics Data System (ADS)

John, T. L.

1996-04-01

Free-free absorption coefficients of the negative neon ion are calculated by the phase-shift approximation based on multiconfiguration Hartree-Fock continuum wave functions. These wave functions accurately account for electron-neon correlation and polarization, and yield scattering cross-sections in excellent agreement with the latest experimental values. The coefficients are expected to give the best current estimates of Ne^- continuous absorption. We find that Ne^- makes only a small contribution (less than 0.3 per cent) to stellar opacities, including hydrogen-deficient stars with enhanced Ne abundances.

Alignment relaxation of Ne*(2pi [J = 1]) atoms in He-Ne* glow discharges

NASA Astrophysics Data System (ADS)

Bahrim, Cristian; Khadilkar, Vaibhav; Matsukuma, Hiraku; Hasuo, Masahiro

2009-11-01

Alignment relaxation of the Ne*(2p5 3p; 2pi [J = 1]) atoms (where i = 2, 5, 7 or 10) induced by collisions with He atoms in glow discharges at 77 K < T < 1,000 K are reported. Close-coupling many-channel quantum calculations using a model potential for the Ne*(2p5 3p) - He system are compared with measurements of the alignment relaxation using the LIFS technique and the Hanle effect. The addition of the dipole polarization potential of the Ne*(2pi [J = 1]) atoms to the spin-orbit coupling and the electrostatic interaction between Ne* and He atoms leads to good agreement between theory and experiment.

ANALYSIS OF BIOTIC AND ABIOTIC FACTORS INFLUENCING THE OCCURRENCE OF WEST NILE VIRUS INFECTION IN TUNISIA.

PubMed

Ben Hassine, Th; Calistri, P; Ippoliti, C; Conte, A; Danzetta, M L; Bruno, R; Lelli, R; Bejaoui, M; Hammami, S

2014-01-01

Eco-climatic conditions are often associated with the occurrence of West Nile Disease (WND) cases. Among the complex set of biotic and abiotic factors influencing the emergence and spread of this vector-borne disease, two main variables have been considered to have a great influence on the probability of West Nile Virus (WNV) introduction and circulation in Tunisia: the presence of susceptible bird populations and the existence of geographical areas where the environmental and climatic conditions are more favourable to mosquito multiplications. The aim of this study was to identify and classify the climatic and environmental variables possibly associated with the occurrence of WNVhuman cases in Tunisia. The following environmental and climatic variables have been considered: wetlands and humid areas, Normalised Difference Vegetation Index (NDVI), temperatures and elevation. A preliminary analysis for the characterization of main variables associated with areas with a history of WNV human cases in Tunisia between 1997 and 2011 has been made. This preliminary analysis clearly indicates the closeness to marshes ecosystem, where migratory bird populations are located, as an important risk factor for WNV infection. On the contrary the temperature absolute seems to be not a significant factor in Tunisian epidemiological situation. In relation to NDVI values, more complex considerations should be made.

Assessing Pathogen Levels in Dairy Lagoon Wastewater and Potential Evaporation Losses

NASA Astrophysics Data System (ADS)

Pandey, P.; Biswas, S.; Souza, A.; Silva-del-Rio, N.; Vaddella, V. K.; Castillo, A. R.

2014-12-01

The ongoing drought in California necessitates the conservation of existing water resources while protecting the water quality. There is a critical need to improve the understanding of evaporation losses from dairy lagoons in California, and their corresponding changes in pathogen levels in the lagoon wastewater. We have carried out preliminary studies involving extensive dairy lagoon water sampling, and batch-scale experiments. The dairy wastewater was collected from both primary and secondary lagoons in three counties of California (Merced, Tulare, and Glenn Counties) for enumerating the levels of E. coli O157:H7, Salmonella spp., and Listeria monocytogenes. Subsequently, we conducted batch-scale experiments at mesophilic (31 and 37 ⁰C) and thermophilic temperatures (43 and 49 ⁰C) to understand the E. coli O157:H7 inactivation process and potential evaporative water losses. In addition, we compared the evaporation losses under the environment of biological activity and the environment of restricted biological activity (extreme environment with low pH). For E. coli O157:H7 enumeration, we used MacConkey agar, while for Salmonella spp., XLD agar was used. Listeria monocytogenes levels were measured using PALCAM agar (with selective supplement). In flushed dairy wastewater (fresh) samples, the average of E. coli O157:H7 levels were 2 × 104 CFU/mL. The average Listeria monocytogenes levels in flushed manure were 9 × 101. The levels of Salmonella spp. were non-detectable. In mesophilic condition (37 ⁰C) after 5 days of incubation, 8% of total water loss was observed, while at thermophilic temperature (49 ⁰C), 70% of total water loss was observed. After 5 days of incubation at 37 ⁰C, E. coli O157:H7 levels in flushed dairy manure were increased from 2.8 × 103 to 5.2 × 104 CFU/mL, while at 49 ⁰C, E. coli O157:H7 levels were reduced from 2.8 × 103 to 5 × 101 CFU/mL after 4 days of incubation. We anticipate that the results of this study would be useful

Update on the Epidemiology of Scorpion Envenomation in the South of Tunisia.

PubMed

Chakroun-Walha, Olfa; Karray, Rim; Jerbi, Mouna; Nasri, Abdennour; Issaoui, Fadhila; Amine, Ben Rebeh; Bahloul, Mabrouk; Bouaziz, Mounir; Ksibi, Hichem; Rekik, Noureddine

2018-03-01

Scorpion envenomation is still a frequent occurance in tropical and subtropical regions. In Tunisia, multiple studies on scorpion envenoming have contributed to an improved understanding of cardiac dysfunction and factors predictive of poor prognosis. These previous studies have contributed to the current standardized management of envenomed patients. However, the epidemiology of scorpion envenoming in Tunisia has not been updated for more than 10 years. The aim of this study was to report an update of the epidemiological features of scorpion envenomation in the southern region of Tunisia. This is a retrospective monocentric study including all patients admitted in the emergency room for scorpion envenomation. Cases were collected from emergency medical files during a 3-year period (2013-2015). The diagnosis of scorpion envenomation was made by history of a scorpion sting. All files in which scorpion envenomation was not certain were excluded. Data are presented as mean±SD with range or percentages, as appropriate. We enrolled 282 patients aged 27.4±22.8 years with a 1:1 sex ratio. During surveillance in the emergency room, 39 patients developed cardiac dysfunction. Overall, 42 patients (14.9%) were at stage 3 of severity, and 240 patients (85.1%) had moderate scorpion envenomation (stage 2). Only 1 patient died a few hours after admission. In the remaining cases, the outcome was good. Our results show the improvement in mortality rates even in severe presentations. This study found that the outcome of scorpion-stung patients has clearly improved. This enhancement can be explained by early medical consultation and standardized management of patients with predictive factors for cardiac dysfunction. Copyright © 2017 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

Mapping the serological prevalence rate of West Nile fever in equids, Tunisia.

PubMed

Bargaoui, R; Lecollinet, S; Lancelot, R

2015-02-01

West Nile fever (WNF) is a viral disease of wild birds transmitted by mosquitoes. Humans and equids can also be affected and suffer from meningoencephalitis. In Tunisia, two outbreaks of WNF occurred in humans in 1997 and 2003; sporadic cases were reported on several other years. Small-scale serological surveys revealed the presence of antibodies against WN virus (WNV) in equid sera. However, clinical cases were never reported in equids, although their population is abundant in Tunisia. This study was achieved to characterize the nationwide serological status of WNV in Tunisian equids. In total, 1189 sera were collected in 2009 during a cross-sectional survey. Sera were tested for IgG antibodies, using ELISA and microneutralization tests. The estimated overall seroprevalence rate was 28%, 95% confidence interval [22; 34]. The highest rates were observed (i) in the north-eastern governorates (Jendouba, 74%), (ii) on the eastern coast (Monastir, 64%) and (iii) in the lowlands of Chott El Jerid and Chott el Gharsa (Kebili, 58%; Tozeur, 52%). Environmental risk factors were assessed, including various indicators of wetlands, wild avifauna, night temperature and chlorophyllous activity (normalized difference vegetation index: NDVI). Multimodel inference showed that lower distance to ornithological sites and wetlands, lower night-time temperature, and higher NDVI in late spring and late fall were associated with higher serological prevalence rate. The model-predicted nationwide map of WNF seroprevalence rate in Tunisian equids highlighted different areas with high seroprevalence probability. These findings are discussed in the perspective of implementing a better WNF surveillance system in Tunisia. This system might rely on (i) a longitudinal survey of sentinel birds in high-risk areas and time periods for WNV transmission, (ii) investigations of bird die-offs and (iii) syndromic surveillance of equine meningoencephalitis. © 2013 Blackwell Verlag GmbH.

Dynamics of pollution-indicator and heterotrophic bacteria in sewage treatment lagoons.

PubMed

Legendre, P; Baleux, B; Troussellier, M

1984-09-01

The spatio-temporal dynamics of pollution-indicator bacteria and aerobic heterotrophic bacteria were studied in the sewage treatment lagoons of an urban wastewater center after 26 months of biweekly sampling at eight stations in these lagoons. Robust statistical methods of time-series analysis were used to study successional steps (through chronological clustering) and rhythmic behavior through time (through contingency periodogram). The aerobic heterotrophic bacterial community showed two types of temporal evolution: in the first four stations, it seems mainly controlled by the nutrient support capacity of the sewage input, whereas in the remaining part of the lagoon, it seems likely that the pollution-indicator bacteria are gradually replaced by other bacterial types that are better adapted to this environment. On the other hand, the pollution-indicator bacteria showed an annual cycle which increased in amplitude at distances further from the wastewater source. The main events in this cycle were produced simultaneously at all stations, indicating control of these bacterial populations by climatic factors, which act through physical and chemical factors, and also through other biological components of this ecosystem (phytoplankton and zooplankton). Finally, we use results from this study to suggest a modified design for a future study program.

[Compulsory admission to hospital in Tunisia: a necessary evolution].

PubMed

Ellouze, Faten; Lahmar, Aymen; Beji, Rami; Dridi, Anis; Fadhel M'rad, Mohamed

2015-01-01

The evolution of the legislation governing compulsory admission to hospital in Tunisia is interesting for two reasons. The country's 2011 revolution notably brought about major changes to the legislative framework, from constitutional through to ordinary laws. At the same time, the current trend for globalisation is also affecting legislation: international laws, treaties and UN charters are imposed on the laws of individual countries. This article looks at how Tunisian law governing compulsory admission to hospital has had to evolve. Copyright © 2015. Published by Elsevier Masson SAS.

Amount and type of derelict gear from the declining black pearl oyster aquaculture in Ahe atoll lagoon, French Polynesia.

PubMed

Andréfouët, Serge; Thomas, Yoann; Lo, Cedrik

2014-06-15

Pearl oyster aquaculture is a major activity in French Polynesia atoll lagoons. After the economic decline that characterized the last decade, concerns recently rose about discarded installations and materials that supported aquaculture practices and by facilities abandoned after they had to close their activities. In May 2013, a first inventory of the type and amount of pearl farms derelict gear (PFDG) was achieved on 47 sites in Ahe lagoon. Surveys were conducted within and outside the boundaries of aquaculture concessions. Twenty types of PFDG littered the lagoon floor and the water column. The most impacted areas were near abandoned grafting houses with up to nine types of PFDG. Forty-five percent of the sites were impacted, including outside concessions. While management authorities are fully aware of the problem, this first assessment is a wake-up call to stimulate the cleaning of lagoons, enhance awareness among farmers, and identify potential ecological consequences on lagoon ecosystems. Copyright © 2014 Elsevier Ltd. All rights reserved.

Hatching rhythms and dispersion of decapod crustacean larvae in a brackish coastal lagoon in Argentina

NASA Astrophysics Data System (ADS)

Anger, K.; Spivak, E.; Bas, C.; Ismael, D.; Luppi, T.

1994-12-01

Mar Chiquita, a brackish coastal lagoon in central Argentina, is inhabited by dense populations of two intertidal grapsid crab species, Cyrtograpsus angulatus and Chasmagnathus granulata. During a preliminary one-year study and a subsequent intensive sampling programme (November December 1992), the physical properties and the occurrence of decapod crustacean larvae in the surface water of the lagoon were investigated. The lagoon is characterized by highly variable physical conditions, with oligohaline waters frequently predominating over extended periods. The adjacent coastal waters show a complex pattern of semidiurnal tides that often do not influence the lagoon, due to the existence of a sandbar across its entrance. Besides frequently occurring larvae (exclusively freshly hatched zoeae and a few megalopae) of the two dominating crab species, those of three other brachyurans ( Plathyxanthus crenulatus, Uca uruguayensis, Pinnixa patagonica) and of one anomuran (the porcellanid Pachycheles haigae) were also found occasionally. Caridean shrimp ( Palaemonetes argentinus) larvae occurred in a moderate number of samples, with a maximum density of 800·m-3. The highest larval abundance was recorded in C. angulatus, with almost 8000°m-3. Significantly more C. angulatus and C. granulata zoeae occurred at night than during daylight conditions, and more larvae (statistically significant only in the former species) during ebb (outflowing) than during flood (inflowing) tides. In consequence, most crab zoeae were observed during nocturnal ebb, the least with diurnal flood tides. Our data suggest that crab larvae do not develop in the lagoon, where the adult populations live, but exhibit an export strategy, probably based upon exogenously coordinated egg hatching rhythms. Zoeal development must take place in coastal marine waters, from where the megalopa eventually returns for settlement and metamorphosis in the lagoon. Significantly higher larval frequency of C. granulata in

The ecological status of Karavasta Lagoon (Albania): Closing the stable door before the horse has bolted?

PubMed

Munari, Cristina; Tessari, Umberto; Rossi, Remigio; Mistri, Michele

2010-02-01

Karavasta is the widest and most important lagoon in Albania. This study aimed to assess the ecological quality status of the lagoon, acquire knowledge of a natural environment which might be exploited for aquaculture, and give management hints on the basis of anthropogenic impact and ecological conditions. A sampling campaign was carried out in 2008: at six stations, benthic fauna, water, and sediment parameters were considered. Statistical analyses were carried out through multivariate procedures (PCA, classification-clustering, SIMPER, RDA, DISTLM, PERMANOVA). Ecological quality was assessed through the AZTI Marine Biotic Index (AMBI), the multivariate AMBI (M-AMBI) and the Benthic Index based on Taxonomic Sufficiency (BITS). Sediment characteristics (percent organic matter, %OM; redox potential discontinuity layer depth, RPDL; particle size composition) and salinity represented contributory influences on lagoon communities. It was possible to distinguish and characterise a confined area, and benthic communities, from a marine-influenced area and its biota. The number of species was quite low when compared with other open Adriatic lagoons. The M-AMBI and BITS classifications gave quite similar results, which seemed consistent with the ecological conditions of the lagoon, that is a distinction in the ecological quality between the seaward and landward stations, with higher ecological quality (EcoQ) at the seaward stations. Given the pressures and the ecological condition of Karavasta, an intensification of aquaculture activities must be considered with caution, since the lagoon seems at significant risk of serious hypereutrophication. This situation is made worse by the limited water exchange with the marine environment due to the irregular dredging of the communication channels. 2009 Elsevier Ltd. All rights reserved.

Does coastal lagoon habitat quality affect fish growth rate and their recruitment? Insights from fishing and acoustic surveys

NASA Astrophysics Data System (ADS)

Brehmer, P.; Laugier, T.; Kantoussan, J.; Galgani, F.; Mouillot, D.

2013-07-01

Ensuring the sustainability of fish resources necessitates understanding their interaction with coastal habitats, which is becoming ever more challenging in the context of ever increasing anthropogenic pressures. The ability of coastal lagoons, exposed to major sources of disturbance, to provide resources and suitable habitats for growth and survival of juvenile fish is especially important. We analysed three lagoons with different ecological statuses and habitat quality on the basis of their eutrophication and ecotoxicity (Trix test) levels. Fish abundances were sampled using fishing and horizontal beaming acoustic surveys with the same protocols in the same year. The relative abundance of Anguilla anguilla, Dicentrarchus labrax or the Mugilidae group was not an indicator of habitat quality, whereas Atherina boyeri and Sparus aurata appeared to be more sensitive to habitat quality. Fish abundance was higher in the two lagoons with high eutrophication and ecotoxicity levels than in the less impacted lagoon, while fish sizes were significantly higher in the two most severely impacted lagoons. This leads us to suggest low habitat quality may increase fish growth rate (by the mean of a cascading effect), but may reduce lagoon juvenile abundance by increasing larval mortality. Such a hypothesis needs to be further validated using greater investigations which take into account more influences on fish growth and recruitment in such variable environments under complex multi-stressor conditions.

Effects of rainfalls variability and physical-chemical parameters on enteroviruses in sewage and lagoon in Yopougon, Côte d'Ivoire

NASA Astrophysics Data System (ADS)

Momou, Kouassi Julien; Akoua-Koffi, Chantal; Traoré, Karim Sory; Akré, Djako Sosthène; Dosso, Mireille

2017-07-01

The aim of this study was to assess the variability of the content of nutrients, oxidizable organic and particulate matters in raw sewage and the lagoon on the effect of rainfall. Then evaluate the impact of these changes in the concentration of enteroviruses (EVs) in waters. The sewage samples were collected at nine sampling points along the channel, which flows, into a tropical lagoon in Yopougon. Physical-chemical parameters (5-day Biochemical Oxygen Demand, Chemical Oxygen Demand, Suspended Particulate Matter, Total Phosphorus, Orthophosphate, Total Kjeldahl Nitrogen and Nitrate) as well as the concentration of EV in these waters were determined. The average numbers of EV isolated from the outlet of the channel were 9.06 × 104 PFU 100 ml-1. Consequently, EV was present in 55.55 and 33.33 % of the samples in the 2 brackish lagoon collection sites. The effect of rainfall on viral load at the both sewage and brackish lagoon environments is significant correlate (two-way ANOVA, P < 0.05). Furthermore, in lagoon environment, nutrients (Orthophosphate, Total Phosphorus), 5-day Biochemical Oxygen Demand, Chemical Oxygen Demand and Suspended Particulate Matter were significant correlated with EVs loads ( P < 0.05 by Pearson test). The overall results highlight the problem of sewage discharge into the lagoon and correlation between viral loads and water quality parameters in sewage and lagoon.

Situation Report--Laos, Malawi, Pakistan, Republic of Korea, Somali Democratic Republic, and Tunisia.

ERIC Educational Resources Information Center

International Planned Parenthood Federation, London (England).

Data relating to population and family planning in six foreign countries are presented in these situation reports. Countries included are Laos, Malawi, Pakistan, Republic of Korea, Somali Democratic Republic, and Tunisia. Information is provided under two topics, general background and family planning situation, where appropriate and if it is…

Selected Bibliography of Educational Materials: Algeria, Libya, Morocco, Tunisia. Vol. 4, No. 2.

ERIC Educational Resources Information Center

Azzouz, Azzedine; And Others

A 100-item bibliography with abstracts of books, newspaper articles, and periodical articles in English and French published predominantly in 1970 offers information on various aspects of education in Algeria, Libya, Morocco, and Tunisia. Emphasis is placed on sections dealing with educational organization in primary, secondary, vocational, and…

Structure and diversity of fishes in a freshwater and coastal subtropical lagoon.

PubMed

Ferreira, N C; Guereschi, R M; Machado, C; Lopes, C A; Nuñer, A P O

2017-04-01

This study examined the fish communities of Peri Lagoon in southern Brazil to aid in the development of an effective management plan because the area is under threat from human activities. Sampling of fish fauna, ichthyoplankton and limnological data were compared between sites, differing by habitat type and characteristics such as depth, substratum composition and vegetation type. Results were significantly related to site, with the highest diversity and abundance recorded at shallow vegetated sites. A total of 14 fish species were recorded throughout the lagoon, with the most abundant being Hyphessobrycon luetkenii. Of the 14 species, half were sampled at their larval stage, suggesting a healthy and protected system. Significantly more larvae and eggs were collected during colder months (autumn to winter) and at sites closer to stream flow, possibly owing to increased food sources and habitat protection. This study highlights the importance of Peri Lagoon as a nursery ground for a wide range of fish species, providing essential information for incorporation into the future protection of fish stocks throughout Brazil. © 2016 The Fisheries Society of the British Isles.

MicroBooNE: The Search For The MiniBooNE Low Energy Excess

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaleko, David

This thesis describes work towards the search for a low energy excess in MicroBooNE. What MicroBooNE is, what the low energy excess is, and how one searches for the latter in the former will be described in detail.

Diuron tolerance and potential degradation by pelagic microbiomes in the Great Barrier Reef lagoon

PubMed Central

Pantos, Olga; Morgan, Thomas C.; Rich, Virginia; Tonin, Hemerson; Bourne, David G.; Mercurio, Philip; Negri, Andrew P.; Tyson, Gene W.

2016-01-01

Diuron is a herbicide commonly used in agricultural areas where excess application causes it to leach into rivers, reach sensitive marine environments like the Great Barrier Reef (GBR) lagoon and pose risks to marine life. To investigate the impact of diuron on whole prokaryotic communities that underpin the marine food web and are integral to coral reef health, GBR lagoon water was incubated with diuron at environmentally-relevant concentration (8 µg/L), and sequenced at specific time points over the following year. 16S rRNA gene amplicon profiling revealed no significant short- or long-term effect of diuron on microbiome structure. The relative abundance of prokaryotic phototrophs was not significantly altered by diuron, which suggests that they were largely tolerant at this concentration. Assembly of a metagenome derived from waters sampled at a similar location in the GBR lagoon did not reveal the presence of mutations in the cyanobacterial photosystem that could explain diuron tolerance. However, resident phages displayed several variants of this gene and could potentially play a role in tolerance acquisition. Slow biodegradation of diuron was reported in the incubation flasks, but no correlation with the relative abundance of heterotrophs was evident. Analysis of metagenomic reads supports the hypothesis that previously uncharacterized hydrolases carried by low-abundance species may mediate herbicide degradation in the GBR lagoon. Overall, this study offers evidence that pelagic phototrophs of the GBR lagoon may be more tolerant of diuron than other tropical organisms, and that heterotrophs in the microbial seed bank may have the potential to degrade diuron and alleviate local anthropogenic stresses to inshore GBR ecosystems. PMID:26989611

Anaplasma marginale and A. phagocytophilum in cattle in Tunisia.

PubMed

M'ghirbi, Youmna; Bèji, Marwa; Oporto, Beatriz; Khrouf, Fatma; Hurtado, Ana; Bouattour, Ali

2016-10-20

Tick-borne diseases caused by Anaplasma species put serious constraints on the health and production of domestic cattle in tropical and sub-tropical regions. After recovering from a primary infection, cattle typically become persistent carriers of pathogens and play a critical role in the epidemiology of the disease, acting as reservoirs of the Anaplasma spp. In this study a duplex PCR assay was used for the simultaneous detection of Anaplasma marginale and Anaplasma phagocytophilum in cattle using two primer pairs targeting msp4 and msp2 genes, respectively. We used this method to analyze DNA preparations derived from 328 blood cattle samples that were collected from 80 farms distributed among Tunisia's four bioclimatic zones. The prevalence of the A. marginale infection (24.7 %) was significantly higher and more widespread (in all bioclimatic areas) than that of A. phagocytophilum (0.6 %), which was found in a mixed infection with A. marginale. The duplex PCR assay used proved to be a rapid, specific and inexpensive mean for the simultaneous detection of Anaplasma marginale and Anaplasma phagocytophilum in cattle blood. It allowed us to report the identification of A. phagocytophilum for the first time in cattle in Tunisia and confirm the presence of A. marginale in cattle from several geographical areas of the country. Further epidemiological studies undertaken using this assay will help improve the surveillance of the associated diseases in the regions where they are endemic.

Transport of steroid hormones, phytoestrogens, and estrogenic activity across a swine lagoon/sprayfield system.

PubMed

Yost, Erin E; Meyer, Michael T; Dietze, Julie E; Williams, C Michael; Worley-Davis, Lynn; Lee, Boknam; Kullman, Seth W

2014-10-07

The inflow, transformation, and attenuation of natural steroid hormones and phytoestrogens and estrogenic activity were assessed across the lagoon/sprayfield system of a prototypical commercial swine sow operation. Free and conjugated steroid hormones (estrogens, androgens, and progesterone) were detected in urine and feces of sows across reproductive stages, with progesterone being the most abundant steroid hormone. Excreta also contained phytoestrogens indicative of a soy-based diet, particularly, daidzein, genistein, and equol. During storage in barn pits and the anaerobic lagoon, conjugated hormones dissipated, and androgens and progesterone were attenuated. Estrone and equol persisted along the waste disposal route. Following application of lagoon slurry to agricultural soils, all analytes exhibited attenuation within 2 days. However, analytes including estrone, androstenedione, progesterone, and equol remained detectable in soil at 2 months postapplication. Estrogenic activity in the yeast estrogen screen and T47D-KBluc in vitro bioassays generally tracked well with analyte concentrations. Estrone was found to be the greatest contributor to estrogenic activity across all sample types. This investigation encompasses the most comprehensive suite of natural hormone and phytoestrogen analytes examined to date across a livestock lagoon/sprayfield and provides global insight into the fate of these analytes in this widely used waste management system.

Transport of Steroid Hormones, Phytoestrogens, and Estrogenic Activity across a Swine Lagoon/Sprayfield System

PubMed Central

Yost, Erin E.; Meyer, Michael T.; Dietze, Julie E.; Williams, C. Michael; Worley-Davis, Lynn; Lee, Boknam; Kullman, Seth W.

2017-01-01

The inflow, transformation, and attenuation of natural steroid hormones, phytoestrogens, and estrogenic activity was assessed across the lagoon/sprayfield system of a prototypical commercial swine sow operation. Free and conjugated steroid hormones (estrogens, androgens, and progesterone) were detected in urine and feces of sows across reproductive stages, with progesterone being the most abundant steroid hormone. Excreta also contained phytoestrogens indicative of a soy-based diet; particularly daidzein, genistein, and equol. During storage in barn pits and the anaerobic lagoon, conjugated hormones dissipated, and androgens and progesterone were attenuated. Estrone and equol persisted along the waste disposal route. Following application of lagoon slurry to agricultural soils, all analytes exhibited attenuation within 2 days. However, analytes including estrone, androstenedione, progesterone, and equol remained detectable in soil at two months post-application. Estrogenic activity in the yeast estrogen screen and T47D-KBluc in vitro bioassays generally tracked well with analyte concentrations. Estrone found to be the greatest contributor to estrogenic activity across all sample types. This investigation encompasses the most comprehensive suite of natural hormone and phytoestrogen analytes examined to date across a lagoon/sprayfield system, and provides global insight into the fate of these analytes in this widely used waste management system. PMID:25148584

Resolving land subsidence within the Venice Lagoon by persistent scatterer SAR interferometry

NASA Astrophysics Data System (ADS)

Teatini, P.; Tosi, L.; Strozzi, T.; Carbognin, L.; Cecconi, G.; Rosselli, R.; Libardo, S.

Land subsidence is a severe geologic hazard threatening the lowlying transitional coastal areas worldwide. Monitoring land subsidence has been significantly improved over the last decade by space borne earth observation techniques based on Synthetic Aperture Radar (SAR) interferometry. Within the INLET Project, funded by Magistrato alle Acque di Venezia - Venice Water Authority (VWA) and Consorzio Venezia Nuova (CVN), we use Interferometric Point Target Analysis (IPTA) to characterize the ground displacements within the Venice Lagoon. IPTA measures the movement of backscattering point targets (PTs) at the ground surface that persistently reflect radar signals emitted by the SAR system at different passes. For this study 80 ERS-1/2 and 44 ENVISAT SAR scenes recorded from 1992 to 2005 and from 2003 to 2007, respectively, have been processed. Highly reliable displacement measurements have been detected for thousands of PTs located on the lagoon margins, along the littorals, in major and small islands, and on single structures scattered within the lagoon. On the average, land subsidence ranges from less than 1 mm/year to 5 mm/year, with some PTs that exhibit values also larger than 10 mm/year depending on both the local geologic conditions and the anthropic activities. A network of a few tens of artificial square trihedral corner reflectors (TCRs) has been established before summer 2007 in order to monitor land subsidence in the inner lagoon areas where “natural” reflectors completely lack (e.g., on the salt marshes). The first interferometric results on the TCRs appear very promising.

The 20Ne(d,p) 21Ne Transfer Reaction in Relation to the s-Process Abundances

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nsangu, C. T.; Laird, A. M.; Parikh, A.

2016-01-01

A study of the Ne-20(d,p)Ne-21 transfer reaction was performed using the Quadrupole Dipole Dipole Dipole (Q3D) magnetic spectrograph in Garching, Germany. The experiment probed excitation energies in Ne-21 ranging from 6.9 MeV to 8.5 MeV. The aim was to investigate the spectroscopic information of Ne-21 within the Gamow window of core helium burning in massive stars. Further information in this region will help reduce the uncertainties on the extrapolation down to Gamow window cross sections of the O-17(alpha,gamma)Ne-21 reaction. In low metallicity stars, this reaction has a direct impact on s-process abundances by determining the fate of O-16 as eithermore » a neutron poison or a neutron absorber. The experiment used a 22-MeV deuteron beam, with intensities varying from 0.5-1 mu A, and an implanted target of Ne-20 of 7 mu g/cm(2) in 40 mu g/cm(2) carbon foils. Sixteen Ne-21 peaks have been identified in the E-x = 6.9-8.5 MeV range, of which only thirteen peaks correspond to known states. Only the previously-known E-x = 7.960 MeV state was observed within the Gamow window.« less

Geochronometry and thermochronometry using nucleogenic 21Ne

NASA Astrophysics Data System (ADS)

Farley, K. A.; Flowers, R. M.; Vasconcelos, P. M.

2011-12-01

Nucleogenic 21Ne is produced by the interaction of α particles with 18O. While the cross section for this reaction is small (about 1 α in 25 million participates), 21Ne excesses can be measured in a variety of minerals, forming the basis of (U-Th)/Ne chronometry. Previous work focused on thermochronometry of U, Th rich trace minerals. For example, Gautheron et al. (2005) studied nucleogenic Ne in zircon and inferred a closure temperature of ~400 C. Our preliminary Ne diffusion data on Durango apatite suggests Tc ~280 C. The method can also be applied to phases with much lower U and Th contents in which the 21Ne is measurable on old and/or large specimens. We have obtained (U-Th)/Ne ages on ~50 mg samples of iron oxides with ppm-level U and Th and Ne ages of 50-500 Ma. For example, hematites from the Neoproterozoic (?) Urucum BIF yield a 21Ne age of 470 ± 15 Ma and post-depositional hydrothermal hematite in the Redwall Limestone in the Grand Canyon yields an age of 251 ± 11 Ma. In both cases (U-Th)/He ages are more than 100 Myr younger. Outstanding issues with this method are 1) the diffusivity of Ne - are we measuring cooling ages or formation ages?, 2) how well known is the production rate?, and 3) in what minerals is the air component sufficiently small to permit precision measurements of 21Ne excesses?

Evidence for an early land use in the Rhône delta (Mediterranean France) as recorded by late Holocene fluvial paleoenvironments (1640-100 BC)

NASA Astrophysics Data System (ADS)

Arnaud-Fassetta, Gilles; De Beaulieu, Jacques-Louis; Suc, Jean-Pierre; Provansal, Mireille; Williamson, David; Leveau, Philippe; Aloïsi, Jean-Claude; Gadel, François; Giresse, Pierre; Oberlin, Christine; Duzer, Danièle

The overall objective of this paper is to describe the late Holocene (1640-100 BC) sedimentary and biological evolution of the Rhône-delta-plain, to interpret the sedimentary facies and palynofacies as the result of the effects of fluvial dynamic fluctuations and relative sea level change and to evaluate the paleohydrological constraints in the development of the land use and settlements of the Camargue. Focus is made on the upper part of V III core drilled on NE of the Vaccarès lagoon. By combining sedimentology, palynology, magnetic susceptibility and archeological data, this study allowed to identify the superposition of three types of paleo-environments (marsh, fluvial floodplain, levee/crevasse splay). This sequence indicates a gradual extension of fluvial environments between the end of the second millennium BC and the 1st century BC. The variability of fluvial dynamic is evident during this period with important flood events which contrast with periods of low flow. Pollen record can be a good marker of the fluvial dynamic variability. The expression of the riparian tree pollen grains in the coarser floodplain deposits could correspond to increased fluvial influence and probably to erosion of riverbank during flood events. The local plants are associated to the low energy sedimentary environments. Focuses are made on the relations between the evolution of the environment and land use. The development of the cereal culture in the floodplain of the Rhône delta has been demonstrated between 1640-1410 and 100 BC. The last alluviation of the Rhône perturbs the research of the archaeological sites in the central part of the delta but the existence of the rural villages from the first part of the first millennium BC is highly possible.

Genetic differentiation in Pyrenophora teres f. teres populations from Syria and Tunisia as assessed by AFLP markers.

PubMed

Bouajila, A; Zoghlami, N; Murad, S; Baum, M; Ghorbel, A; Nazari, K

2013-06-01

To investigate the level of genetic differentiation and diversity among Pyrenophora teres isolate populations originating from different agro-ecological areas of Syria and Tunisia and to determine the potential of AFLP profiling in genotyping Pyrenophora teres f. teres. In this study, AFLP markers have been employed to identify patterns of population structure in 20 Pyrenophora teres f. teres populations from Syria and Tunisia. Ninety-four isolates were studied by the use of a protocol that involved stringent PCR amplification of fragments derived from digestion of genomic DNA with restriction enzymes EcoRI and MesI. Based on 401 amplified polymorphic DNA markers (AFLP), variance analyses indicated that most of the variation was partitioned within rather than between populations. Genotypic diversity (GD) was high for populations from Rihane, local landraces and different agro-ecological zones (GD = 0·75-0·86). There was high genetic differentiation among pathogen populations from different host populations in Syria (Gst  = 0·31, ht = 0·190) and Tunisia (Gst  = 0·39, ht = 0·263), which may be partly explained by the low gene flow around the areas sampled. A phenetic tree revealed three groups with high bootstrap values (55, 68, 76) and reflected the grouping of isolates based on host, or agro-ecological areas. AFLP profiling is an effective method for typing the genetically diverse pathogen Pyrenophora teres f. teres. The study represents a comparative analysis of the genetic diversity in P. teres isolates from two countries spanning two continents and also shows that several distinct P. teres genotypes may be found in a given environment. The implications of these findings for Pyrenophora teres f. teres evolutionary potential and net blotch-resistance breeding in Syria and Tunisia were also discussed. © 2012 The Society for Applied Microbiology.

13. Sewage treatment lagoon, drainage control at center left, looking ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

13. Sewage treatment lagoon, drainage control at center left, looking south - Ellsworth Air Force Base, Delta Flight, Launch Control Facility, County Road CS23A, North of Exit 127, Interior, Jackson County, SD

Estimating greenhouse gas emissions from a waste lagoon

USDA-ARS?s Scientific Manuscript database

A cost-effective approach was used to investigate the relationship between emission of the greenhouse gases (GHG) CO2, CH4, and N2O and energy fluxes from a swine waste lagoon. Energy fluxes were calculated using the Penman method. The energy fluxes showed a diurnal pattern as expected of such flux...

Selected Bibliography of Materials; Algeria, Libya, Morocco, Tunisia. Volume 1, Number 2, 1967.

ERIC Educational Resources Information Center

Azzouz, Azzedine; And Others

A bibliography with abstracts of 106 items from books and articles covers materials on education in the Maghreb countries of Tunisia, Libya, Algeria, and Morocco. Special emphasis is given to the two problems besetting the area's educational system: illiteracy and multilingualism. The entries cover philosophy and theory of education,…

SPREADING LAGOONED SEWAGE SLUDGE ON FARMLAND: A CASE HISTORY

EPA Science Inventory

This project demonstrated that land application is feasible and practical for a metropolitan treatment plant for disposal of a large volume (265,000 cu m) of stabilized, liquid sewage sludge stored in lagoons. The project involved transportation of sludge by semi-trailer tankers ...

Cervical cancer screening: women's knowledge, attitudes, and practices in the region of Monastir (Tunisia).

PubMed

El Mhamdi, S; Bouanene, I; Mhirsi, A; Bouden, W; Soussi Soltani, M

2012-12-01

In Tunisia, cervical cancer is considered the second leading cancer in women and causes high morbidity and mortality. This study aimed to investigate women's knowledge, attitudes, and practices of cervical cancer screening in the region of Monastir (Tunisia). We conducted a cross-sectional study exploring the cervical cancer screening knowledge, attitudes, and practices of women in the region of Monastir. The study was conducted in health centers in this region from 1st March to 30th June 2009. Data were collected using a structured questionnaire containing 15 items on demographic status, knowledge of risk factors and screening methods, and attitudes toward the relevance and effectiveness of cervical cancer screening. A total of 900 women agreed to take part in the study. Their mean age was 41.6±12.4 years and 64% did not exceed the primary level of education. According to the constructed scores, 22.8% of the participants had good knowledge of cervical cancer risk factors and 38.2% had good knowledge of screening methods. Multiple logistic regression analysis showed that women aged 45 and older, married, with good knowledge of risk factors and screening methods were more likely to undergo cervical cancer screening (P-value<0.01). This study provides useful information that could be utilized by both researchers and those involved in public health programs. The results show the need for educational programs to enhance women's adherence to cervical cancer screening programs in Tunisia. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

Organotins' fate in lagoon sewage system: dealkylation and sludge sorption/desorption.

PubMed

Ophithakorn, Thiwari; Sabah, Aboubakr; Delalonde, Michele; Bancon-Montigny, Chrystelle; Suksaroj, Thunwadee Tachapattaworakul; Wisniewski, Christelle

2016-11-01

Organotin compounds (OTs) have been widely used for their biocidal properties and as stabilizers in various industrial applications. Due to their high toxicity, organotins are subject to many studies regarding their behavior in wastewater treatment plant and aquatic environment. However, few studies are available regarding their behavior in lagoon sewage system, although such treatment is commonly used for sewage treatment in low-population areas. The present study aimed at studying the fate of organotins (monobutyltin (MBT), dibutyltin (DBT), and tributyltin (TBT)) in lagoon sewage system. Short-term experiments, carried out at lab scale, consisted in sampling sludge from aerobic stabilization ponds, and then quantifying sorption and desorption of the different organotin species, as well as their respective transformation, under defined operating conditions (e.g., tributyltin spike and dilution) simulating possible change in the surrounding environment of sludge in the lagoon. Results established that a very important percentage of the OTs was localized in the solid phase of the sludge (more than 98 %), whatever the operating conditions may be; however, transformation and locations of the three OT species differed according to the different conditions of sludge dilution, TBT spiking, and test duration. After dilution of lagoon sludge, TBT desorption from sludge was observed; it was supposed that dealkylation of TBT after desorption occurred rapidly and increased dissolved MBT and DBT in liquid phase; MBT sorbed subsequently on solid phase. The nature of the diluent (i.e., tap water or saline solution) appeared to slightly influence the sludge behavior. After TBT spiking, TBT was supposed to be rapidly sorbed but also transformed in DBT and MBT that would as well sorbed on the sludge, which explained the decrease of these species in the liquid phase. Tests aimed at studying long-term effect of TBT spiking demonstrated that the sorbed species could be remobilized

Aghien lagoon: a sustainable resource of fresh water for the city of Abidjan (Ivory Coast)? Description of the project and preliminary results

NASA Astrophysics Data System (ADS)

Kamagaté, Bamory; Effebi, Rose K.; Goula Bi, Tié Albert; Lanciné Goné, Droh; Noufé, Djibril; Diallo, Seydou; Ehouman, Serge K.; Koffi, Thierry; Zamblé Trabi, Armand; Lazare, Kouakou; Paturel, Jean Emmanuel; Perrin, Jean-Louis; Salles, Christian; Seguis, Luc; Tournoud, Marie-George; Karoui, Hela

2016-04-01

With more than 6 million inhabitants, Abidjan district faces tremendous difficulties in water supply. The aquifer of the Continental Terminal which is actually the only drinking water source of the city shows a decline of resources and water demand is increasing due to the population growth. Moreover significant evidences of chemical and biological pollution of the groundwater are observed The Aghien lagoon, the largest freshwater pool located near Abidjan, has been identified by the State of Côte d'Ivoire as a potential resource for the production of drinking water.. The main objective of this project is to assess the quantitative and qualitative capacity of the Aghien lagoon to complement the water supply of Abidjan city in the near future. The main components of the project are: • to assess the water budget of the lagoon and its tributaries, • to characterize the spatial and temporal variability of contaminant levels and fluxes from the tributaries toward the lagoon, • to assess the sustainability of the water resources (quantity and quality) of the lagoon according to land use changes in the catchments . The project started in January 2015. The first year was devoted to the set-up of hydro-meteorological gauges within the lagoon watershed. Three major tributaries of the lagoon are considered, the Mé (4000 km2), the Djibi (78 km2) and Bete (206 km2) rivers. Since the start of the project, bi-monthly hydrochemical sampling surveys have been carried out along the tributaries and in the lagoon. The data available from the surveys concern the physico-chemical parameters, trace elements, all the forms of nitrogen and phosphorus, organic carbon, suspended solids. The Djibi and Bete watersheds are partly urbanized while the Mé basin is mainly rural. Baseflow has been identified as the major contribution to streamflow at the annual scale. The Mé flows into a channel downstream to the Aghien lagoon but during the floods, water from the Mé River can flow up the

Hydrological heterogeneity, nutrient dynamics and water quality of a non-tidal lentic ecosystem (Lesina Lagoon, Italy)

NASA Astrophysics Data System (ADS)

Roselli, Leonilde; Fabbrocini, Adele; Manzo, Cristina; D'Adamo, Raffaele

2009-10-01

The dynamics of the Lesina coastal lagoon (Italy) in terms of nutrients, phytoplankton and chemical-physical parameters were evaluated, together with their functional relationships with freshwater inputs, in order to identify ecosystem responses to changes in driving forces in a Mediterranean non-tidal lentic environment. Lesina Lagoon is a shallow coastal environment characterised by limited exchange with coastal waters, which favours enrichment of nutrients and organic matter and benthic fluxes within the system. Lagoon-sea exchanges are influenced by human management. There is a steep salinity gradient from East to West. High nitrogen and silica values were found close to freshwater inputs, indicating wastewater discharges and agricultural runoff, especially in winter. Dissolved oxygen was well below saturation (65%) near sewage and runoff inputs in the western part of the lagoon during summer. Classification in accordance with EEA (2001) guidelines suggests the system is of "poor" or "bad" quality in terms of nitrogen concentrations in the eastern zone during the winter rainy period. In terms of phosphate concentrations, the majority of the stations fall into the "good" category, with only two stations (close to the sewage and runoff inputs) classed as "bad". In both cases, the raw nitrogen levels make the lagoon a P-limited system, especially in the eastern part. There was wide space-time variability in chlorophyll a concentrations, which ranged from 0.25 to 56 μg l -1. No relationships between chlorophyll a and nutrients were found, suggesting that autotrophic biomass may be controlled by a large number of internal and external forcing factors driving eutrophication processes. Water quality for this type of environment depends heavily on pressure from human activities but also on the management of sewage treatment plants, agricultural practices and the channels connecting the lagoon with the sea.

BooNE

NASA Astrophysics Data System (ADS)

McKenney, S.; Smith, D.; Koutsoliotas, S.; Church, E.; Stancu, I.; Vandalen, G. J.; Johnson, R. A.; Bugel, L.; Conrad, J. M.; Formaggio, J.; Shaevitz, M. H.; Tamminga, B.; Zimmerman, E.; Bhat, C.; Brown, B. C.; Ford, R.; Kasper, P.; Kourbanis, I.; Malensek, A.; Marsh, W.; Martin, P.; Mills, F.; Moore, C.; Russell, A.; Stefanski, R.; Eitel, K.; Garvey, G. T.; Hawker, E.; Louis, W. C.; Mills, G. B.; Sandberg, V.; Sapp, B.; Tayloe, R.; White, D. H.; Imlay, R.; Kim, H. J.; Malik, A.; Metcalf, W.; Sung, M.; Azemoon, T.; Ball, R.; Berbeco, R.; Riles, K.; Roe, B. P.; Wadia, N.; Yamamoto, J.; Bazarko, A. O.; Meyers, P. D.; Shoemaker, F. C.

2000-10-01

The phenomenon of neutrino oscillations, where a neutrino of one type spontaneously transforms into a neutrino of another type, has important and far-reaching consequences for particle physics and cosmology. For this phenomenon to occur, at least one neutrino must be massive and the heretofore observed lepton flavor conservation law must be violated. There are, at present, several results that indicate neutrino oscillations and it is not clear how and if these experimental results are indicative of the situation that actually obtains in Nature. There is evidence for a deficit of electrons neutrinos observed emanating from the sun. There is evidence for a deficit of electron neutrinos compared to muon neutrinos created in the upper atmosphere. And, there is an excess of electron antineutrinos observed in a beam of muon antineutrinos by the LSND experiment. The Booster Neutrino Experiment (BooNE) will focus on the final observation by definitely testing the LSND result. BooNE has been approved to run at Fermilab and is currently under construction. If the LSND result is due to oscillations, the first stage of the experiment (miniBooNE) will observe approximately 1000 oscillation events in the first calendar year of operation.

Radiochemical methodology for the determination of the mass balance of suspended particulate materials exchanged at the inlets of the Venice Lagoon

NASA Astrophysics Data System (ADS)

Degetto, S.; Cantaluppi, C.

2004-11-01

The Venice Lagoon is connected to the Adriatic Sea by three inlets, with an average daily water inflow of 345∗10 6 m 3. Due to the diversion of the major rivers out of the lagoon (done in the past centuries), the sediment supply from the drainage basin is now very low when compared to the amount of sediment exchanged at the inlets (<1%). The limited sediment supply and the combined action of natural and anthropic pressures (e.g. waves, ships, fishing activities, dredging for navigation purposes) have caused in the last few decades a significant erosion of mudflats and salt-marshes. In order to investigate the history and the characteristics of the above phenomenon, with particular regard to the most recent years and the future trend, a wide radiochemical survey has been carried out in the whole lagoon, including the characterisation of the suspended particulate matter entering and leaving the lagoon in different tidal and meteorological conditions, with the aim of obtaining an indirect estimate of the sediment mass balance of the lagoon. The proposed radiochemical methodology, which is based on concentration measurements of airborne radionuclides in suspended particulate matter, appears to be an useful alternative to direct methods (e.g. bathymetric campaigns in the lagoon or mass fluxes measurements of the suspended particulate materials exchanged at the inlets). The results obtained, which show a complex sedimentary situation, highlight the erosion acting in some central and southern lagoon areas but recognise also the present accumulation phase coming into view in the northern lagoon.

Stone Age settlement and Holocene water level changes of the Baltic Sea in the Torvajoe Basin area, Narva-Luga Klint Bay, NE Estonia

NASA Astrophysics Data System (ADS)

Raig, Hanna; Rosentau, Alar; Muru, Merle; Risberg, Jan

2014-05-01

The Tõrvajõe basin is located in NE Estonia in the southern part of the Narva-Luga Klint Bay, that is characterized by slow post-glacial isostatic uplift (about 0-1mm/yr) and slowly undulating low topography. Post-glacial changes of the water-level of the Baltic Sea have at times flooded the area, and at times, it has emerged as terrestrial land. In addition to a complex geological development, the surroundings of the Tõrvajõe basin are interesting from the archaeological point of view because of abundant archaeological findings in the area, of which the oldest (c 8.1 cal ka BP) from the Mesolithic period and the majority, indicating very intense habitation (c 7.1-5.5 cal ka BP), from the Neolithic period. Development of the Tőrvajőe basin area during the period of Stone Age settlement (c 8.1-5.5 cal. ka BP) is studied with multiple geological and archaeological proxies. Sediments are described by lithostratigraphical methods, loss-on-ignition. AMS radiocarbon dates are used to date events and create an age-depth model. Environment is described by pollen analyses and water environment by siliceous microfossil analyses. Palaeogeographical reconstructions for time slices of interest are created to illustrate Stone Age settlement pattern and changes of the coastline and landscape over time. The aim of this interdisciplinary study is to investigate and associate palaeoenvironmental conditions and water-level changes with Stone Age settlement pattern in the Tőrvajőe area. Results show four developmental stages in the post-glacial history of the basin: Ancylus Lake lagoon, mire, lagoon during the Litorina Sea and mire. During the Ancylus Lake transgression at about 10.8-10.2 cal. ka BP a spit started to form north of the basin and a lagoon evolved behind it. Following the Ancylus Lake regression river activity and formation of palaeosoil and fen peat took place. Due to the Litorina Sea transgression, that was initially slower but accelerated around 7.8-7.6 cal ka

Dioxins in the Venice lagoon: Present situation, projects and recovering hypotheses.

PubMed

Raccanelli, S; Bonamin, V

2000-01-01

Venice is famous around the world for its uniqueness and architectural splendours, arts and the history of the "Serenissima Repubblica", as it was known in the past, but few are aware that Venice economy is strongly dependent on the industrial activities based mainly on the adjacent Porto Marghera area. For many years, the lagoon that physically separates the city from the dry land has avoided association between the concern connected with the pollution derived from these industrial activities and the public perception of Venice. Since 1995, dioxins have appeared as a lagoon contaminant, and their presence, at such a level requiring immediate "in depth" studies and interventions, has been fully realized for decades.

speed-ne: Software to simulate and estimate genetic effective population size (Ne ) from linkage disequilibrium observed in single samples.

PubMed

Hamilton, Matthew B; Tartakovsky, Maria; Battocletti, Amy

2018-05-01

The genetic effective population size, N e , can be estimated from the average gametic disequilibrium (r2^) between pairs of loci, but such estimates require evaluation of assumptions and currently have few methods to estimate confidence intervals. speed-ne is a suite of matlab computer code functions to estimate Ne^ from r2^ with a graphical user interface and a rich set of outputs that aid in understanding data patterns and comparing multiple estimators. speed-ne includes functions to either generate or input simulated genotype data to facilitate comparative studies of Ne^ estimators under various population genetic scenarios. speed-ne was validated with data simulated under both time-forward and time-backward coalescent models of genetic drift. Three classes of estimators were compared with simulated data to examine several general questions: what are the impacts of microsatellite null alleles on Ne^, how should missing data be treated, and does disequilibrium contributed by reduced recombination among some loci in a sample impact Ne^. Estimators differed greatly in precision in the scenarios examined, and a widely employed Ne^ estimator exhibited the largest variances among replicate data sets. speed-ne implements several jackknife approaches to estimate confidence intervals, and simulated data showed that jackknifing over loci and jackknifing over individuals provided ~95% confidence interval coverage for some estimators and should be useful for empirical studies. speed-ne provides an open-source extensible tool for estimation of Ne^ from empirical genotype data and to conduct simulations of both microsatellite and single nucleotide polymorphism (SNP) data types to develop expectations and to compare Ne^ estimators. © 2018 John Wiley & Sons Ltd.

75 FR 53299 - Issuance of NPDES General Permits for Wastewater Lagoon Systems Located in Indian Country in...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-31

... ENVIRONMENTAL PROTECTION AGENCY [FRL-9195-3] Issuance of NPDES General Permits for Wastewater... Elimination System (NPDES) general permits for wastewater lagoon systems that are located in Indian country in... general permit for wastewater lagoon systems that are located in Indian country in the State of Colorado...

Improved water quality and reduction of odorous compounds in anaerobic lagoon columns receiving pre-treated pig wastewater

USDA-ARS?s Scientific Manuscript database

Large volumes of wastewater from confined pig production are stored in anaerobic lagoons. Control methods are needed to reduce air pollution by foul odors released from these lagoons. In a pilot-scale experiment, we evaluated the effect of pig wastewater pre-treatment on reducing the concentration o...

Zoonotic Cutaneous Leishmaniasis Prevalence Among Farmers in Central Tunisia, 2014.

PubMed

Bellali, Hedia; Chemak, Fraj; Nouiri, Issam; Ben Mansour, Dorra; Ghrab, Jamila; Chahed, Mohamed Kouni

2017-01-01

Zoonotic cutaneous leishmaniasis (ZCL) is endemic in central Tunisia and is more prevalent in rural agricultural areas. The aim of this work was to determine ZCL prevalence among farmers and to test their availability to take ownership of the problem and participate actively to fight and address the disease. A sample of farmers from Sidi Bouzid, central Tunisia, was selected randomly. Farmers were interviewed using a standardized questionnaire about ZCL lesion occurrence, its date of onset among family members, and the farmers' availability to contribute to fighting this disease. ZCL occurred in at least one of the family members of 38.5% interviewed farmers. The disease was endemic with recurrent epidemics every 4 or 5 years. ZCL among farmers was associated with irrigation management. With regard to ZCL preventive measures, the majority of farmers agreed and expressed willingness to collaborate (93.1%), to follow health care facilities instructions (73.1%), and to join the nongovernmental organization (NGO) (56.9%). However, they did not agree to reduce irrigation activities mainly at night, to live far from their irrigated fields, or to sleep out of their houses at night. ZCL is more prevalent in farmers engaged in irrigation activities. Farmers are not agreeable to reducing their activity to avoid exposure to the sand fly bites. Thus, population involvement and commitment is required to implement effective control measures to fight and address ZCL.

[The limnology of Tunisia: physicochemical study].

PubMed

Boumaiza, M

1984-01-01

Several chemical and physical parameters are measured in forty seven stations, distributed on the most part of the hydrographic systems of Tunisia. Some parameters: temperature of the water (T), salinity (S, electric conductivity (CE), chloride (Cl-), total hardness (DT) and turbidity (TUR) show great variations in the Northern hydrographic systems. In these systems, the parameters (S, CE, Cl-, DT) are generally elevated in the tributaries of the south bank of the Medjerda, the North-East streams, Melah and Tine Streams which flow in the Ichkeul lake. The waters in these septentrional systems are sometimes very turbid. The waters of the meridional hydrological system are very clear. The resurgence thermal waters are characterized by the small amplitude of variations of the studied parameters. The waters are alkaline, generally very mineralized they are well oxygenized in the no-polluted stations.

Assessment of hydrologic and water quality data collected in Abbotts Lagoon watershed, Point Reyes National Seashore, California, during water years 1999 and 2000

USGS Publications Warehouse

Kratzer, Charles R.; Saleh, Dina K.; Zamora, Celia

2006-01-01

Abbotts Lagoon is part of Point Reyes National Seashore, located about 40 miles northwest of San Francisco and about 20 miles south of Bodega Bay. Water-quality samples were collected quarterly during water year 1999 at a site in each of three connected lagoons that make up Abbotts Lagoon and at a site in its most significant tributary. The quarterly samples were analyzed for major ions, nutrients, and chlorophyll-a. A bed-sediment sample was collected in each lagoon during August 1999 and was analyzed for organic carbon, iron, and total phosphorus. Seven tributaries were sampled during a February 1999 storm and four during an April 1999 storm. These samples were analyzed only for nutrients. One storm sample collected in April 1999 from a tributary downstream of the I Ranch dairy was analyzed for a suite of 47 compounds indicative of wastewater. Continuous water-level recorders were installed in the most significant tributary and the two largest lagoons for portions of the study. A water budget analysis for an April 2000 storm indicated that the main tributary accounted for 85 percent of surface inflows to Abbotts Lagoon. The portion of the surface inflow from the main tributary was lower in the February 1999 storms and is a function of upstream storage and vegetative growth in the tributary basins. Another water budget analysis for a period of no surface inflow (June and July 2000) indicated that the net ground-water contribution was an outflow (seepage) from Abbotts Lagoon of about 0.3 ft3/s. Salinity increased and nutrient concentrations decreased from upstream to downstream in the chain of lagoons. The lower lagoon, nearest the ocean, had less organic carbon and total phosphorus in the bed sediment than the upper lagoons. The two tributaries originating in the I Ranch dairy had the highest concentrations of nutrients in storm runoff, and the highest loading rates and yields of ammonia and phosphorus. These tributaries account for only 10.3 percent of the area

Distribution of Keratinophilic Fungi in Soil Across Tunisia: A Descriptive Study and Review of the Literature.

PubMed

Anane, Sonia; Al-Yasiri, Mohammed Hashim Yasir; Normand, Anne-Cécile; Ranque, Stéphane

2015-08-01

Data on the frequency and distribution of keratinophilic fungi in soil of Tunisia are scanty. The present survey aimed to describe the distribution of keratinophilic fungi in soils collected in Tunisia. Keratinophilic fungi were isolated using Vanbreuseghem's hair-baiting technique from 354 soil samples collected in 15 governorates of Tunisia and identified according to their morphology with further DNA and MALDI-TOF analysis when necessary. Keratinophilic fungi were isolated from 46.3 % of the samples from 14 governorates. Chrysosporium keratinophilum was the predominant species (30.5 %) followed by Microsporum gypseum (27.4 %). Other isolated species included C. tropicum (14.0 %), C. indicum (11.0 %), Chaetomium sp. (4.9 %), Arthroderma curreyi, Arthroderma cuniculi (3.7 % each), C. merdarium (3.1 %), Anixiopsis stercoraria, C. parvum, Paecilomyces lilacinus, Auxarthron zuffianum (2.4 % each), Fusarium oxysporum, Aphanoascus verrucosus, Gymnascella dankaliensis (1.2 % each) and 12 other species (0.6 % each). Two to five distinct fungal species were associated with 11.5 % of the positive samples. Keratinophilic fungi were more frequently isolated in rural (54.8 %) than in urban (41.1 %) areas (p = 0.012). The highest (100 %) positive culture rate was noted in soil collected in stables. Keratinophilic fungi are frequent throughout Tunisian territory, particularly in soils with a high organic matter content that should be regarded as humans and animals mycoses reservoir.

Sources and fate of sediment organic matter in Asia's largest brackish water lagoon and nearby mangrove ecosystem

NASA Astrophysics Data System (ADS)

Mukherjee, R.; Muduli, P. R.; Barik, S.; Kumar, S.

2017-12-01

Coastal lagoons and mangrove ecosystems regularly undergo natural (tidal) and anthropogenic (riverine inputs) forcings. After effects of these forcings cause coastal environments to sustain high biological production leading to high suspended organic matter (OM) and hence fast sedimentation and accumulation of OM in sediments.The different sources of OM and its burial in tropical lacustrine and mangrove systems have been rarely studied in detail with a few reports from Indian estuaries. The present study attempts to understand the sources and fate organic matter at two Ramsar sites, viz. Chilika Lake (Asia's largest brackish water lagoon) and nearby Bhitarkanika mangroves, located in the east coast of India. We measured nitrogen and carbon content (% N and % C) and isotopic composition (δ13Corg and δ15N) of OM at different depths in eight and three sediment cores collected from the Chilika lagoon and Bhitarkanika mangroves, respectively. Overall, the mean δ13Corg and % C in the lagoon were ‒21.10 ± 0.79 ‰ and 0.84 ± 0.47 %, respectively; whereas the same for mangrove cores were ‒24.56 ± 0.80 ‰ and 1.04 ± 0.26 %, respectively. Similarly, average δ15N and % N in the lagoon cores were 4.15 ± 0.63 ‰ and 0.11 ± 0.05 %, respectively; for mangrove cores the values were 4.28 ± 0.50 ‰ and 0.07 ± 0.01 %, respectively. Preliminary analysis of the isotopic composition (δ13Corg and δ15N) and elemental ratios indicates that organic carbon in the sediment at Bhitarkanika mangrove was of terrigenous, marine and in situ origin, whereas cores of Chilika lagoon showed predominantly marine signature. No relationship between δ13Corg of suspended and sediment in the Chilika lagoon indicates these two organic pools to be not directly coupled. End member mixing model in the mangrove ecosystem indicate on an average 50 % terrestrial contribution to the OM pool.

Dynamics of pollution-indicator and heterotrophic bacteria in sewage treatment lagoons.

PubMed Central

Legendre, P; Baleux, B; Troussellier, M

1984-01-01

The spatio-temporal dynamics of pollution-indicator bacteria and aerobic heterotrophic bacteria were studied in the sewage treatment lagoons of an urban wastewater center after 26 months of biweekly sampling at eight stations in these lagoons. Robust statistical methods of time-series analysis were used to study successional steps (through chronological clustering) and rhythmic behavior through time (through contingency periodogram). The aerobic heterotrophic bacterial community showed two types of temporal evolution: in the first four stations, it seems mainly controlled by the nutrient support capacity of the sewage input, whereas in the remaining part of the lagoon, it seems likely that the pollution-indicator bacteria are gradually replaced by other bacterial types that are better adapted to this environment. On the other hand, the pollution-indicator bacteria showed an annual cycle which increased in amplitude at distances further from the wastewater source. The main events in this cycle were produced simultaneously at all stations, indicating control of these bacterial populations by climatic factors, which act through physical and chemical factors, and also through other biological components of this ecosystem (phytoplankton and zooplankton). Finally, we use results from this study to suggest a modified design for a future study program. Images PMID:6497372

A GIS Approach for Reconstructing the Litorina Sea Lagoon in Tolkuse-Rannametsa Area, Eastern Gulf of Riga.

NASA Astrophysics Data System (ADS)

Habicht, Hando-Laur; Rosentau, Alar; Jõeleht, Argo; Hang, Tiit; Kohv, Marko

2015-04-01

The eastern coast of the Gulf of Riga in the NE Baltic Sea is characterized by slow post-glacial isostatic uplift (about 1mm/yr) and slowly undulating low topography. Therefore even small increases in sea-level can easily lead to the flooding of considerable areas. The complex deglaciation history of the Baltic Sea area left, at times, south western Estonia submerged, while at other times, it emerged as terrestrial land. Different transgressive and regressive development stages of the Baltic Sea did not only shape the landscape, but also influenced the locations of the Stone Age settlements which were closely bound to the coastal areas which also include estuaries and lagoonal systems. The coastal region of the Gulf of Riga is abundant in Meso- and Neolithic settlement sites. The present study combines LiDAR, ground-penetrating radar (GPR) and geological data to reconstruct development of the Litorina Sea lagoon in Tolkuse-Rannametsa area and to create prognostic palaeogeographic maps in order to search for Meso- and Neolithic coastal settlement sites. Over 47 km of GPR profiling was done; sediments were described and dated in 37 cores two riverbank outcrops. Diatoms were analysed in the master core. A semi-automatic method for the removal of modern anthropogenic features from LiDAR derived digital elevation model (DEM) was developed, tested and used. In modelling process the impact of sedimentary processes subsequent to the time being modelled was taken into account by employing a backstripping methodology. The differential glacio-isostatic uplift within the study area was taken into account by using interpolated water-level surfaces. Palaeogeographic reconstructions shed new light into region's post-glacial coastal evolution and enabled us to suggest the possible locations of the Stone Age settlements with some of the proposed areas buried under up to 3 m thick peat layer. The results of the current study provide new chronological and shore displacement data

Selected Bibliography of Educational Materials: Algeria, Libya, Morocco, Tunisia. Vol. 1 No. 3 1967.

ERIC Educational Resources Information Center

Azzouz, Azzedine; And Others

This annotated compilation of 108 educational publications in Arabic, French, and English includes texts and data on elementary and secondary school curricula in the Maghreb countries (Tunisia, Morroco, Algeria, and Libya). Categories in this bibliography include--(1) Philosophy and Theory of Education, (2) Administration of the Educational…

Selected Bibliography of Educational Materials: Algeria, Libya, Morocco, Tunisia. Volume 8, Number 1, 1974.

ERIC Educational Resources Information Center

Azzouz, Azzedine; And Others

This annotated bibliography contains 100 English-language annotations of newspapers and government publications covering educational topics of interest to North Africans. The majority of the items cited were published in 1974. Citations are categorized by country: Algeria, Libya, Morocco, and Tunisia. Within these major categories are subtopics…

Multivariate analysis of morphological diversity among closely related Daucus species and subspecies in Tunisia

USDA-ARS?s Scientific Manuscript database

The genus Daucus includes about 20-25 species worldwide. Northern Africa represents a major center of diversity of Daucus, with Tunisia thought to contain 11 species and seven subspecies. We assessed morphological diversity from a Daucus germplasm collection of 103 accessions at the National Gene Ba...

Eutrophication increases methane emission to the atmosphere in tropical lagoons: insights from two Ivory Coast sites

NASA Astrophysics Data System (ADS)

José-mathieu Koné, Yéfanlan; Vieira Borges, Alberto

2017-04-01

Eutrophication increases methane emission to the atmosphere in tropical lagoons: insights from two Ivory Coast sites. Y J M Koné (1) & A.V. Borges (2) (1) Centre de recherches océanologiques (CRO) d'Abidjan, (Ivory Coast) (2) University of Liège, Chemical Oceanography Unit, Liège, Belgium (Belgium) Eutrophication is a worldwide environmental problem and a definitive solution is far from being achieved, despite the large number of studies documenting its causes. In small aquatic ecosystems, excessive growth of macrophytes is a well known undesirable consequence of eutrophication. When these plants die and sink to the bottom the decomposing biomass depletes oxygen content in the water column thus leading to anoxia promoting methane (CH4) production. Here, we reported the CH4 data obtained during six campaigns covering the annual cycle in two small lagoons of Ivory Coast (Ono, Kodjoboué) that are contrasted in the degree of eutrophication and the corresponding coverage of macrophytes (e.g. Echinochloa pyramidalis, Eichhornia crassipes, Hydrilla verticillata). Our data showed a high spatio-temporal variability of CH4 within the lagoons and between the two systems, with CH4 concentrations in surface waters ranging between 80 to 74,604 nmol L-1. The highest CH4 concentration values were observed in the eutrophic Ono lagoon that is covered by 80% of macrophytes, suggesting that lagoons dominated by macrophytes are significant sources of CH4 toward the atmosphere.

Investigation of residence time and groundwater flux in Venice Lagoon: comparing radium isotope and hydrodynamic models.

PubMed

Rapaglia, John; Ferrarin, Christian; Zaggia, Luca; Moore, Willard S; Umgiesser, Georg; Garcia-Solsona, Ester; Garcia-Orellana, Jordi; Masqué, Pere

2010-07-01

The four naturally-occurring isotopes of radium were coupled with a previously evaluated hydrodynamic model to determine the apparent age of surface waters and to quantify submarine groundwater discharge (SGD) into the Venice Lagoon, Italy. Mean apparent age of water in the Venice Lagoon was calculated using the ratio of 224Ra to 228Ra determined from 30 monitoring stations and a mean pore water end member. Average apparent age was calculated to be 6.0 d using Ra ratios. This calculated age was very similar to average residence time calculated for the same period using a hydrodynamic model (5.8 d). A mass balance of Ra was accomplished by quantifying each of the sources and sinks of Ra in the lagoon, with the unknown variable being attributed to SGD. Total SGD were calculated to be 4.1 +/- 1.5, 3.8 +/- 0.7, 3.0 +/- 1.3, and 3.5 +/- 1.0 x 10(10) L d(-1) for (223,224,226, 228)Ra, respectively, which are an order of magnitude larger than total mean fluvial discharge into the Venice Lagoon (3.1 x 10(9) L d(-1)). The SGD as a source of nutrients in the Venice Lagoon is also discussed and, though significant to the nutrient budget, is likely to be less important as the dominant control on SGD is recirculated seawater rather than freshwater. 2009 Elsevier Ltd. All rights reserved.

[H1N1 influenza vaccines in Tunisia: efficiency and safety].

PubMed

Chaabane, Amel; Aouam, Karim; Ben Fredj, Nadia; Toumi, Adnen; Braham, Dorra; A Boughattas, Naceur; Chakroun, Mohamed

2011-01-01

We carried out this study in order to evaluate the effectiveness and the safety of the two H1N1 vaccines available in Tunisia: Focetria(®) and Panenza(®). It's a prospective epidemiological study including 601 vaccinated subjects. The vaccine effectiveness was based on the occurrence of flu clinical symptoms after vaccination. The safety was based on the occurrence of unexpected events after vaccines administration. The vaccines imputability was established according to Begaud et al. method. The number of subjects vaccinated by Focetria(®) is more important than Panenza(®). The efficiency of vaccines would be 93.6%. Neither the medical statue nor the type of the vaccine used influence the occurrence of a flu episode after vaccination. We recorded 406 adverse effects (32.4%) with a high score of imputability (I3). Focetria(®) adverse effects were more frequent than Panenza(®) ones (p = 0.009). Almost all adverse events disappeared within few days. The two vaccines used in Tunisia remain enough efficient to face the influenza (H1N1) pandemia and are well tolerated independently of the demographic and pathological statue of the vaccinated person as well as nature of the vaccine used. © 2011 Société Française de Pharmacologie et de Thérapeutique.

The geothermal gradient map of Central Tunisia: Comparison with structural, gravimetric and petroleum data

NASA Astrophysics Data System (ADS)

Dhia, Hamed Ben

1987-10-01

Five hundred and fifty temperature values, initially measured as either bottom-hole temperatures (BHT) or drill-stem tests (DST), from 98 selected petroleum exploration wells form the basis of a geothermal gradient map of central Tunisia. A "global-statistical" method was employed to correct the BHT measurements, using the DST as references. The geothermal gradient ranges from 23° to 49°C/km. Comparison of the geothermal gradient with structural, gravimetric and petroleum data indicates that: (1) the general trend of the geothermal gradient curves reflects the main structural directions of the region, (2) zones of low and high geothermal gradient are correlated with zones of negative and positive Bouguer anomalies and (3) the five most important oil fields of central Tunisia are located near the geothermal gradient curve of 40° C/km. Such associations could have practical importance in petroleum exploration, but their significance must first be established through further investigation and additional data.

The NeXus data format.

PubMed

Könnecke, Mark; Akeroyd, Frederick A; Bernstein, Herbert J; Brewster, Aaron S; Campbell, Stuart I; Clausen, Björn; Cottrell, Stephen; Hoffmann, Jens Uwe; Jemian, Pete R; Männicke, David; Osborn, Raymond; Peterson, Peter F; Richter, Tobias; Suzuki, Jiro; Watts, Benjamin; Wintersberger, Eugen; Wuttke, Joachim

2015-02-01

NeXus is an effort by an international group of scientists to define a common data exchange and archival format for neutron, X-ray and muon experiments. NeXus is built on top of the scientific data format HDF5 and adds domain-specific rules for organizing data within HDF5 files, in addition to a dictionary of well defined domain-specific field names. The NeXus data format has two purposes. First, it defines a format that can serve as a container for all relevant data associated with a beamline. This is a very important use case. Second, it defines standards in the form of application definitions for the exchange of data between applications. NeXus provides structures for raw experimental data as well as for processed data.

The NeXus data format

DOE Office of Scientific and Technical Information (OSTI.GOV)

Könnecke, Mark; Akeroyd, Frederick A.; Bernstein, Herbert J.

2015-01-30

NeXus is an effort by an international group of scientists to define a common data exchange and archival format for neutron, X-ray and muon experiments. NeXus is built on top of the scientific data format HDF5 and adds domain-specific rules for organizing data within HDF5 files, in addition to a dictionary of well defined domain-specific field names. The NeXus data format has two purposes. First, it defines a format that can serve as a container for all relevant data associated with a beamline. This is a very important use case. Second, it defines standards in the form of application definitionsmore » for the exchange of data between applications. NeXus provides structures for raw experimental data as well as for processed data.« less

Impact of the Tunisian Revolution on homicide and suicide rates in Tunisia.

PubMed

Ben Khelil, Mehdi; Gharbaoui, Meriem; Farhani, Fethia; Zaafrane, Malek; Harzallah, Hana; Allouche, Mohamed; Zhioua, Mongi; Hamdoun, Moncef

2016-12-01

To analyze the impact of the Tunisian Revolution on suicide and homicide patterns in Tunisia. It is a retrospective, cross-sectional study, including all the cases of homicides and suicides that occurred during an 8-year period (2007-2014) in Northern Tunisia. We compared data before and after the revolution. After the revolution, the number of suicides rose 1.7 times, with a prevalence rising from 1.8 to 3.12 suicides per 100,000 persons per year. Homicides rose 1.3 times after the revolution. For both manner of death, victims were mostly males, aged between 20 and 39 years, living in urban areas. Hanging and self-immolation rose, respectively, 1.8 and 3 times after 2011. We observed suicide cases most frequently occurred in public places and in front of public administration after 2011. Homicide victims' profile and circumstances showed a single variation which is an increase in number of cases happening in rural areas. Our results proved a short-term impact of the transition period on homicides and suicides. Urgent preventive measures are needed especially to decrease the suicide rates.

‘This Is Real Misery’: Experiences of Women Denied Legal Abortion in Tunisia

PubMed Central

Hajri, Selma; Raifman, Sarah; Gerdts, Caitlin; Baum, Sarah; Foster, Diana Greene

2015-01-01

Barriers to accessing legal abortion services in Tunisia are increasing, despite a liberal abortion law, and women are often denied wanted legal abortion services. In this paper, we seek to explore the reasons for abortion denial and whether these reasons had a legal or medical basis. We also identify barriers women faced in accessing abortion and make recommendations for improved access to quality abortion care. We recruited women immediately after they had been turned away from legal abortion services at two facilities in Tunis, Tunisia. Thirteen women consented to participate in qualitative interviews two months after they were turned away from the facility. Women were denied abortion care on the day they were recruited due to three main reasons: gestational age, health conditions, and logistical barriers. Nine women ultimately terminated their pregnancies at another facility, and four women carried to term. None of the women attempted illegal abortion services or self-induction. Further research is needed in order to assess abortion denial from the perspective of providers and medical staff. PMID:26684189

Infestation of the spur-thighed tortoise (Testudo graeca) by Hyalomma aegyptium in Tunisia.

PubMed

Gharbi, Mohamed; Rjeibi, Mohamed Ridha; Rouatbi, Mariem; Mabrouk, Moez; Mhadhbi, Moez; Amairia, Safa; Amdouni, Yosra; Boussaadoun, Mohamed Anis

2015-04-01

We examined 210 spur-thighed tortoises (Testudo graeca) for the presence of ticks in Tunisia during May 2014. A total number of 602 adult ticks were collected and identified leading to the estimation of parasitological indicators. All the ticks belonged to a single species: Hyalomma aegyptium. The mean infestation prevalence was 66.2%, mean overall infestation intensity and abundance were 4.33 and 2.86 ticks/tortoise respectively. Our survey showed that tortoises were significantly more infested by male ticks than females (p<0.001). The ticks were mainly present in the posterior limbs compared to other body regions (p<0.05). There was no significance variation of length and weight of tortoises according to sex (p<0.05). There was a significant correlation between the tortoises' size (length and weight) and tick infestation. This study showed high tick burdens of spur-thighed tortoises in Tunisia; further investigations are needed to determine exactly the role of this tick species in the transmission of different zoonotic pathogens. Copyright © 2015 Elsevier GmbH. All rights reserved.

Characterization and evolution of the sediments of a Mediterranean coastal lagoon located next to a former mining area.

PubMed

García, Gregorio; Muñoz-Vera, Ana

2015-11-15

Coastal lagoons are ecosystems that are relatively enclosed water bodies under the influence of both the terrestrial and the marine environment, being vulnerable to human impacts. Human activities, such as mining extraction, are significant anthropogenic coastal stressors that can negatively affect ecosystems and communities. In light of the above, the objective of this research is to examine the influence of metal mining activities on the composition of sediments of a Mediterranean coastal lagoon, named Mar Menor. This paper presents a comprehensive characterization for grain size, mineralogy, geochemistry and organic matter of sediments of this coastal lagoon, investigating their variation along space and time. Sedimentation dynamics are ruling clearly the grain size predominant in each area of the Mar Menor coastal lagoon, determining the existence of entrainment, transport and sedimentation areas. For minerals, elements and organic matter, sedimentation dynamics are also determining their distribution. Copyright © 2015 Elsevier Ltd. All rights reserved.

Benthic foraminifera as bio-indicators of trace element pollution in the heavily contaminated Santa Gilla lagoon (Cagliari, Italy).

PubMed

Frontalini, Fabrizio; Buosi, Carla; Da Pelo, Stefania; Coccioni, Rodolfo; Cherchi, Antonietta; Bucci, Carla

2009-06-01

In order to assess the response of benthic foraminifera to trace element pollution, a study of benthic foraminiferal assemblages was carried out into sediment samples collected from the Santa Gilla lagoon (Sardinia, Italy). The lagoon has been contaminated by industrial waste, mainly trace elements, as well as by agricultural and domestic effluent. The analysis of surficial sediment shows enrichment in trace elements, including Cr, Cu, Hg, Ni, Pb and Zn. Biotic and abiotic data, analyzed with multivariate techniques of statistical analysis, reveal a distinct separation of both the highly polluted and less polluted sampling sites. The innermost part of the lagoon, comprising the industrial complex at Macchiareddu, is exposed to a high load of trace elements which are probably enhanced by their accumulation in the finer sediment fraction. This area reveals lower diversity and higher percentages of abnormalities when compared to the outermost part of the lagoon.

Influence of environmental variation on the bacterioplankton community and its loss to viral lysis in the Curonian Lagoon

NASA Astrophysics Data System (ADS)

Šulčius, Sigitas; Reunamo, Anna; Paškauskas, Ričardas; Leskinen, Piia

2018-05-01

Coastal lagoons are continuously exposed to strong environmental gradients that determine the distribution and trophic interactions of microbial communities. Therefore, in this study we assessed whether and how environmental changes influence the bacterial community and its vulnerability to viral infection and lysis along the major environmental gradient in the Curonian Lagoon. We found significant differences in bacterial community profiles, their richness and evenness between the riverine, freshwater southern part and the Baltic Sea water intrusion-influenced northern part of the lagoon, suggesting strong environmental control of the structure of bacterial communities. Viruses were found to be play an important role in bacterial mortality in the Curonian Lagoon, being responsible for the removal of 20-50% of the bacterial standing stock. We observed differences in virioplankton decay rates and virus burst sizes between the northern and southern parts of the lagoon. However, no relationships were found between viral activity and bacterial communities within the lagoon ecosystem. The frequency of infected cells and virus-mediated bacterial mortality (VMBM) remained constant among the sampling sites irrespective of differences in bacteria community assemblages and environmental conditions. The results indicate that factors determining changes in bacterial diversity are different from the factors limiting their vulnerability to viral infection and lysis. This study also suggests that under changing environmental conditions, virus-bacteria interactions are more stable than the interacting viral and bacterial communities themselves. These findings are important for understanding the functioning of the coastal ecosystems under the rapidly changing local (spatial and temporal) and global (e.g. eutrophication, climate change) conditions.

A spatially resolved model of seasonal variations in phytoplankton and clam ( Tapes philippinarum) biomass in Barbamarco Lagoon, Italy

NASA Astrophysics Data System (ADS)

Spillman, C. M.; Hamilton, D. P.; Hipsey, M. R.; Imberger, J.

2008-08-01

Barbamarco Lagoon (area = 7 km 2) is in the Po River Delta, adjoining the Northern Adriatic Sea, and supports a commercially valuable clam ( Tapes philippinarum) fishery. This study investigated interactions of the lagoon with adjacent coastal waters and inland riverine inputs by modelling both the lagoon and the Northern Adriatic Sea, using a coupled three-dimensional (3D) hydrodynamic-ecological model (ELCOM-CAEDYM) adapted to include the clam population. The clam model accounted for carbon (C), nitrogen (N) and phosphorus (P) biomass in the benthos through parameterisations for filtration, excretion, egestion, respiration, mortality, and harvesting. Multiple clam size classes were included in a new population dynamics sub-model. Output from the coupled model was validated against hydrodynamic and water quality data from intensive field sampling and routine monitoring. Time scales of tidal flushing, primary production and clam grazing were investigated with the model to demonstrate that food supply to clam populations is dominated by phytoplankton inputs from the Northern Adriatic Sea. Effects of clam cultivation on nutrient concentrations and phytoplankton biomass in Barbamarco Lagoon were primarily localised, with strong tidal flushing minimising impacts of clam filtration on lagoon-wide nutrient concentrations at current clam stocking levels. Clam populations were found to alter the cycling of nutrients in the system, causing the lagoon to become a net sink for particulate organic matter and to export dissolved organic matter to the adjacent sea via tidal flushing. Ecosystem health and sensitivity of nutrient cycles to clam cultivation are important considerations for the long term sustainable management and potential expansion of the fishery.

Selected Bibliography of Educational Materials: Algeria, Libya, Morocco, Tunisia. Volume 4, Number 1, 1970.

ERIC Educational Resources Information Center

Azzouz, Azzedine, Comp.; And Others

A 100-item bibliography with abstracts of books, newspaper articles, and periodical articles in English and French published predominantly in 1969 offers information on various aspects of education in Algeria, Libya, Morocco, and Tunisia. Emphasis is placed on sections dealing with educational organization in primary, secondary, vocational, and…

The MiniBooNE detector

NASA Astrophysics Data System (ADS)

Aguilar-Arevalo, A. A.; Anderson, C. E.; Bartoszek, L. M.; Bazarko, A. O.; Brice, S. J.; Brown, B. C.; Bugel, L.; Cao, J.; Coney, L.; Conrad, J. M.; Cox, D. C.; Curioni, A.; Djurcic, Z.; Finley, D. A.; Fleming, B. T.; Ford, R.; Garcia, F. G.; Garvey, G. T.; Green, C.; Green, J. A.; Hart, T. L.; Hawker, E.; Imlay, R.; Johnson, R. A.; Karagiorgi, G.; Kasper, P.; Katori, T.; Kobilarcik, T.; Kourbanis, I.; Koutsoliotas, S.; Laird, E. M.; Linden, S. K.; Link, J. M.; Liu, Y.; Liu, Y.; Louis, W. C.; Mahn, K. B. M.; Marsh, W.; Martin, P. S.; McGregor, G.; Metcalf, W.; Meyer, H.-O.; Meyers, P. D.; Mills, F.; Mills, G. B.; Monroe, J.; Moore, C. D.; Nelson, R. H.; Nguyen, V. T.; Nienaber, P.; Nowak, J. A.; Ouedraogo, S.; Patterson, R. B.; Perevalov, D.; Polly, C. C.; Prebys, E.; Raaf, J. L.; Ray, H.; Roe, B. P.; Russell, A. D.; Sandberg, V.; Sands, W.; Schirato, R.; Schofield, G.; Schmitz, D.; Shaevitz, M. H.; Shoemaker, F. C.; Smith, D.; Soderberg, M.; Sorel, M.; Spentzouris, P.; Stancu, I.; Stefanski, R. J.; Sung, M.; Tanaka, H. A.; Tayloe, R.; Tzanov, M.; Van de Water, R.; Wascko, M. O.; White, D. H.; Wilking, M. J.; Yang, H. J.; Zeller, G. P.; Zimmerman, E. D.; MiniBooNE Collaboration

2009-02-01

The MiniBooNE neutrino detector was designed and built to look for ν→ν oscillations in the (sin 2θ,Δm) parameter space region where the LSND experiment reported a signal. The MiniBooNE experiment used a beam energy and baseline that were an order of magnitude larger than those of LSND so that the backgrounds and systematic errors would be completely different. This paper provides a detailed description of the design, function, and performance of the MiniBooNE detector.

Rheumatic heart disease in a developing country: Incidence and trend (Monastir; Tunisia: 2000-2013).

PubMed

Sriha Belguith, Asma; Koubaa Abdelkafi, Afifa; El Mhamdi, Sana; Ben Fredj, Manel; Abroug, Hela; Ben Salah, Arwa; Bouanene, Inès; Hassine, Fahima; Amara, Amal; Bhiri, Sana; Derbel, Abdelkarim; Gamra, Habib; Maatouk, Faouzi; Soltani, Mohamed Soussi

2017-02-01

The penicillin therapy of β hemolytic streptococcal pharyngitis has aided in the decrease of rheumatic heart disease (RHD) in developing countries. Tunisia is an endemic area, however, and incidence of RHD is weakly documented. We aimed at establishing the standardized incidence rate (SIR) of RHD in Monastir governorate and at determining RHD prevalence among hospitalized patients in two cardiology departments. From the regional register of Monastir Hospital morbidity, we have selected newly diagnosed patients with RHD, residents of Monastir, and hospitalized to the 2 cardiology departments between 2000 and 2013 (2001 not included). We studied 676 newly admitted patients. We estimate 1060 to be the number of new annual RHD cases in Tunisia. The SIR per 10 5 person-years was 10.97, being 9.3 in men and 19.1 in women, respectively. We have notified a negative trend of crude incidence rate/10 5 Inhabitants (Inh) (CIR) (r=-0.23, p<10 -3 ), and a strong positive correlation between age and CIR/10 5 Inh (r=0.989, p<10 -4 ). RHD lethality was 1%. We have registered 728 hospitalizations for RHD, representing 2.5% of all cardiology hospitalizations [95% CI: 2.3-2.7%], with a prevalence for 13.3% for women aged 15-29years. The median hospital stay was 9days (IQR: 5-15). Our results confirm the RHD incidence decrease, consistent with epidemiological transition in Tunisia. We have also emphasized on the close trend of RHD with age and the predominance of RHD among women especially at the procreation age. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Political Culture and Risk Analysis: An Outline of Somalia, Tunisia, and Libya

DTIC Science & Technology

2016-11-21

analysis, risk assessment, national maturity, independence move- ments, extremists, national violence , Africa, Somalia, Somaliland, Puntland, Tunisia...changed in terms of actors, but not in any appreciable reduction of violence . In the north, any episodes of conflict were negligible in scale and...duration, never approaching that of the south. The continuous violence in the south, in fact, is unprecedented in Somali history.21 Despite any

Water Hyacinths for Upgrading Sewage Lagoons to Meet Advanced Wastewater Treatment Standards, Part 1

NASA Technical Reports Server (NTRS)

Wolverton, B. C.; Mcdonald, R. C.

1975-01-01

Water hyacinths, Eichhornia crassipes Mart. Solms, have demonstrated the ability to function as an efficient and inexpensive final filtration system in a secondary domestic sewage lagoon during a three month test period. These plants reduced the suspended solids, biochemical oxygen demanding substances, and other chemical parameters to levels below the standards set by the state pollution control agency. The water hyacinth-covered secondary lagoon utilized in this experiment had a surface area of 0.28 hectare (0.70 acre) with a total capacity of 6.8 million liters (1.5 million gallons), receiving an inflow of 522,100 liters (115,000 gallons) per day from a 1.1 hectare (3.8 acre) aerated primary sewage lagoon. These conditions allowed a retention time of 14 to 21 days depending on the water hyacinth evapotranspiration rates. The desired purity of final sewage effluent can be controlled by the water hyacinth surface area, harvest rate, and the retention time.

ANALYSIS OF SWINE LAGOONS AND GROUND WATER FOR ENVIRONMENTAL ESTROGENS

EPA Science Inventory

A method was developed for analysis of low levels of natural (estradiol, estrone, estriol) and synthetic (ethynylestradiol) estrogens in ground water and swine waste lagoon effluent. The method includes solid phase extraction of the estrogens, preparation of pentafluorobenzyl der...

Quantifying groundwater exchange rates in a beach barrier lagoon using a radioisotopic tracer and geophysical methods: Younger Lagoon, Santa Cruz, CA

NASA Astrophysics Data System (ADS)

Richardson, C. M.; Swarzenski, P. W.; Johnson, C.

2013-12-01

Coastal lagoons are highly productive systems with a strong dependence on the physico-chemical regime of their surrounding environment. Groundwater interactions with the nearshore environment can drive ecosystem stability and productivity. Lagoons with restricted surface connectivity interact with coastal waters via subsurface flow paths that follow natural hydraulic gradients, producing a dynamic freshwater-saltwater mixing zone with submarine groundwater discharge (SGD) regions that are tidally influenced. Recent studies demonstrate the importance of SGD in maintaining nearshore ecology through a number of processes, including enhanced chemical loadings, focused biogeochemical transformations, and complex water mixing scenarios (Slomp and Van Cappellen, 2004 and Taniguchi et al., 2002). Groundwater discharge to the coastal ocean is often slow, diffuse and site-specific. Traditional methods used to evaluate SGD fluxes operate at varying scales and typically result in over or underestimates of SGD. Novel monitoring and evaluation methods are required in order to better understand how coastal aquifer systems influence multi-scalar water and nutrient budgets. Recently developed methods to determine fluid exchange rates include the use of select U- and Th-series radionuclides, multi-channel resistivity imaging, as well as the integration of temperature data and 1-D analytical modeling. Groundwater fluxes were examined in a coastal lagoon system to characterize the physics of subsurface fluid transport evidenced by visible seepage faces at low tide. Fluid exchange rates were quantified to determine the spatial and temporal variability of groundwater movement using thermal time series, water level data, and a coupled radiotracer-geophysical method. Our investigation of subsurface characteristics and groundwater fluxes using both traditional and newly-developed methods indicated that seasonal water inputs and tidal controls on water table elevation significantly

Changes of Sand Fly Populations and Leishmania infantum Infection Rates in an Irrigated Village Located in Arid Central Tunisia

PubMed Central

Barhoumi, Walid; Fares, Wasfi; Cherni, Saifedine; Derbali, Mohamed; Dachraoui, Khalil; Chelbi, Ifhem; Ramalho-Ortigao, Marcelo; Beier, John C.; Zhioua, Elyes

2016-01-01

The current spread of zoonotic visceral leishmaniasis (ZVL) throughout arid areas of Central Tunisia is a major public health concern. The main objective of this study is to investigate whether the development of irrigation in arid bio-geographical areas in Central Tunisia have led to the establishment of a stable cycle involving sand flies of the subgenus Larroussius and Leishmania infantum, and subsequently to the emergence of ZVL. Sand flies were collected from the village of Saddaguia, a highly irrigated zone located within an arid bio-geographical area of Central Tunisia by using modified Centers for Diseases Control (CDC) light traps. Morphological keys were used to identify sand flies. Collected sand flies were pooled with up to 30 specimens per pool according to date and tested by nested Polymerase Chain Reaction (PCR) DNA sequencing from positive pools was used to identify Leishmania spp. A total of 4915 sand flies (2422 females and 2493 males) were collected from Saddaguia in September and in October 2014. Morphological identification confirmed sand flies of the subgenus Larroussius to be predominant. PCR analysis followed by DNA sequencing indicated that 15 pools were infected with L. infantum yielding an overall infection rate of 0.6%. The majority of the infected pools were of sand fly species belonging to subgenus Larroussius. Intense irrigation applied to the arid bio-geographical areas in Central Tunisia is at the origin of the development of an environment capable of sustaining important populations of sand flies of the subgenus Larroussius. This has led to the establishment of stable transmission cycles of L. infantum and subsequently to the emergence of ZVL. PMID:26999176

Changes of Sand Fly Populations and Leishmania infantum Infection Rates in an Irrigated Village Located in Arid Central Tunisia.

PubMed

Barhoumi, Walid; Fares, Wasfi; Cherni, Saifedine; Derbali, Mohamed; Dachraoui, Khalil; Chelbi, Ifhem; Ramalho-Ortigao, Marcelo; Beier, John C; Zhioua, Elyes

2016-03-16

The current spread of zoonotic visceral leishmaniasis (ZVL) throughout arid areas of Central Tunisia is a major public health concern. The main objective of this study is to investigate whether the development of irrigation in arid bio-geographical areas in Central Tunisia have led to the establishment of a stable cycle involving sand flies of the subgenus Larroussius and Leishmania infantum, and subsequently to the emergence of ZVL. Sand flies were collected from the village of Saddaguia, a highly irrigated zone located within an arid bio-geographical area of Central Tunisia by using modified Centers for Diseases Control (CDC) light traps. Morphological keys were used to identify sand flies. Collected sand flies were pooled with up to 30 specimens per pool according to date and tested by nested Polymerase Chain Reaction (PCR) DNA sequencing from positive pools was used to identify Leishmania spp. A total of 4915 sand flies (2422 females and 2493 males) were collected from Saddaguia in September and in October 2014. Morphological identification confirmed sand flies of the subgenus Larroussius to be predominant. PCR analysis followed by DNA sequencing indicated that 15 pools were infected with L. infantum yielding an overall infection rate of 0.6%. The majority of the infected pools were of sand fly species belonging to subgenus Larroussius. Intense irrigation applied to the arid bio-geographical areas in Central Tunisia is at the origin of the development of an environment capable of sustaining important populations of sand flies of the subgenus Larroussius. This has led to the establishment of stable transmission cycles of L. infantum and subsequently to the emergence of ZVL.

The NeXus data format

DOE PAGES

Könnecke, Mark; Akeroyd, Frederick A.; Bernstein, Herbert J.; ...

2015-01-30

NeXus is an effort by an international group of scientists to define a common data exchange and archival format for neutron, X-ray and muon experiments. NeXus is built on top of the scientific data format HDF5 and adds domain-specific rules for organizing data within HDF5 files, in addition to a dictionary of well defined domain-specific field names. The NeXus data format has two purposes. First, it defines a format that can serve as a container for all relevant data associated with a beamline. This is a very important use case. Second, it defines standards in the form of application definitionsmore » for the exchange of data between applications. As a result, NeXus provides structures for raw experimental data as well as for processed data.« less

SUPERFUND TREATABILITY CLEARINGHOUSE: FINAL REPORT: DEVELOPMENT OF OPTIMUM TREATMENT SYSTEM FOR WASTEWATER LAGOONS PHASE II - SOLVENT EXTRACTION LABORATORY TESTING

EPA Science Inventory

The U.S. Army surveyed innovative treatment techniques for restoration of hazardous waste lagoons and selected solvent extraction as cost-effective restoration for further study. This treatability study focuses on treatment of organic (explosive) contaminated lagoon sediments w...

[Contribution of Leishmania identification using polymerase chain reaction--restriction fragment length polymerase for epidemiological studies of cutaneous leishmaniasis in Tunisia].

PubMed

Bousslimi, N; Ben Abda, I; Ben Mously, R; Siala, E; Harrat, Z; Zallagua, N; Bouratbine, A; Aoun, K

2014-02-01

Three forms of cutaneous leishmaniasis (CL) are endemic in Tunisia. The identification of the causative species is useful to complete epidemiological data and to manage the cases. The aim of this study is to assess PCR-RFLP technique in the identification of Leishmania species responsible of CL in Tunisia and to compare the results of this technique to those of isoenzyme analysis. Sixty-one CL lesions were sampled. Dermal samples were tested by culture on NNN medium and analyzed by PCR-RFLP assay targeting the ITS1 region of ribosomal DNA. Species identification was performed by both iso-enzymatic typing for positive cultures and analysis of restriction profiles after enzymatic digestion by HaeIII of the obtained amplicons. Thirty-eight (62%) samples were positive by culture. The iso-enzymatic typing of 32 isolates identified 3 L. infantum, 23 L. major MON-25 and 6 L. tropica MON-8. Sixty samples were positive by PCR. The PCR-RFLP digestion profiles of the 56 PCR products identified 12 L. infantum, 38 L. major and 6 L. tropica. The results of both techniques were concordant in the 32 strains identified by both techniques. Species identification correlated with the geographical distribution of CL forms endemic in Tunisia. Results of PCR-RFLP revealed highly concordant with those of isoenzyme electrophoresis. Thanks to its simplicity, rapidity and ability to be performed directly on biological samples, this technique appears as an interesting alternative for the identification of Leishmania strains responsible of CL in Tunisia. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Is there any change in the prevalence of intestinal and urinary parasitosis among "non-permanent resident" students in Tunisia ?

PubMed

Trabelsi, Sonia; Bouchakoua, Myiram; Aouinet, Amira; Sellami, Amira; Khaled, Samira

2012-07-01

Intestinal parasitosis are cosmopolitan affections, often related to the fecal peril. However urinary bilharziosis is a disease eliminated in Tunisia. As part of monitoring the emergence and re-emergence of intestinal parasitosis and urinary bilharziasis, foreign students benefit from parasitological systematic monitoring stool and urine during their enrollment to the University. To study the prevalence of various intestinal parasitosis and urinary bilharziasis among non permanent resident students in Tunisia. A retrospective survey was carried at the Laboratory of Parasitology- Mycology of Charles Nicolle Hospital of Tunis during the inscription period of 6 university years 2005-2010. 328 students profited from a parasitological examination of stool and urine. 144 students (43.9%) harbored intestinal parasites. More than one parasite was detected in 69 students (47.9%). Intestinal protozoa were the majority of identified parasites (96.9%). 9.7% of identified parasites were pathogenic. Three cases (0.91%) of urinary bilharziasis were diagnosed. The prevalence of intestinal and urinary parasitism among the "non-permanent residents" students in Tunisia has not changed. This justifies a systematic parasitologic monitoring for students coming from areas of high endemicity of parasitosis in order to avoid the introduction of these.

First detection of co-circulation of West Nile and Usutu viruses in equids in the south-west of Tunisia.

PubMed

Ben Hassine, T; De Massis, F; Calistri, P; Savini, G; BelHaj Mohamed, B; Ranen, A; Di Gennaro, A; Sghaier, S; Hammami, S

2014-10-01

In the last fifteen years, West Nile Virus (WNV) has dramatically expanded its geographic range and is now considered the most widespread arbovirus in the world. In Tunisia, West Nile Fever (WNF) outbreaks were reported in humans in 1997, 2003 and 2012. Usutu Virus (USUV), which is a 'new' emerging Flavivirus antigenically close to WNV, has never been reported in Tunisia. A serological investigation in 284 equids was conducted in 2012 in the southern west region of the country to assess the presence and prevalence of the WNV and USUV infection. Of the 284 samples tested by competitive enzyme-linked immunoassay, 129 were positive. Of these, 120 (42.3%) had WNV-specific neutralizing antibodies. The prevalence was significantly higher in areas closer to the oasis compared with that of the surrounding arid areas. Antibody titres against USUV were also reported in 10 equids. This was the first evidence of USUV circulation in Tunisia. Data recorded by this study indicate that WNV and USUV have circulated/are circulating in the region and that there is an urgent need to adapt the current surveillance programmes to this new scenario. © 2014 Blackwell Verlag GmbH.

Natural infection of Algerian hedgehog, Atelerix algirus (Lereboullet 1842) with Leishmania parasites in Tunisia.

PubMed

Chemkhi, Jomaa; Souguir, Hejer; Ali, Insaf Bel Hadj; Driss, Mehdi; Guizani, Ikram; Guerbouj, Souheila

2015-10-01

In Tunisia, Leishmania parasites are responsible of visceral leishmaniasis, caused by Leishmania infantum species while three cutaneous disease forms are documented: chronic cutaneous leishmaniasis due to Leishmania killicki, sporadic cutaneous form (SCL) caused by L. infantum and the predominant zoonotic cutaneous leishmanaisis (ZCL) due to Leishmania major. ZCL reservoirs are rodents of the Psammomys and Meriones genera, while for SCL the dog is supposed to be a reservoir. Ctenodactylus gundii is involved in the transmission of L. killicki. However, other mammals could constitute potential reservoir hosts in Tunisia and other North African countries. In order to explore the role of hedgehogs as potential reservoirs of leishmaniasis, specimens (N=6) were captured during July-November period in 2011-2013 in an SCL endemic area in El Kef region, North-Western Tunisia. Using morphological characteristics, all specimens were described and measured. Biopsies from liver, heart, kidney and spleen of each animal were used to extract genomic DNA, which was further used in PCR assays to assess the presence of Leishmania parasites. Different PCRs targeting kinetoplast minicircles, ITS1, mini-exon genes and a repetitive Leishmania- specific sequence, were applied. To further identify Leishmania species involved, RFLP analysis of amplified fragments was performed with appropriate restriction enzymes. Using morphological characters, animals were identified as North African hedgehogs, also called Algerian hedgehogs, that belong to the Erinaceidae family, genus Atelerix Pomel 1848, and species algirus (Lereboullet, 1842). PCR results showed in total that all specimens were Leishmania infected, with different organs incriminated, mainly liver and spleen. Results were confirmed by direct sequencing of amplified fragments. Species identification showed that all specimens were infected with L. major, three of which were additionally co-infected with L. infantum. The present study

ANALYSIS OF SWINE LAGOONS AND GROUND WATER FOR ENVIRONMENTAL ESTROGENS

EPA Science Inventory

A method was developed for analysis of low levels of natural (estradiol, estrone, estriol) and synthetic (ethinyl estradiol) estrogens in ground water and swine waste lagoon effluent. The method includes solid phase extraction of the estrogens, preparation of pentafluorobenzyl de...

NPDES Permit for Lame Deer Lagoon Wastewater Treatment Facility in Montana

EPA Pesticide Factsheets

Final permit authorizes the Northern Cheyenne Utilities Commission to discharge from its Lame Deer Lagoon wastewater treatment facility located in Rosebud County, Montana to Lame Deer Creek, a tributary to Rosebud Creek.

Situation Reports--Ceylon, Costa Rica, Ghana, Haiti, Morocco, Sudan, Tunisia, and U.S.A.

ERIC Educational Resources Information Center

International Planned Parenthood Federation, London (England).

Data relating to population and family planning in eight countries are presented in these situation reports. Countries included are Ceylon, Costa Rica, Ghana, Haiti, Morocco, Sudan, Tunisia, and the United States of America. Information is provided under two topics, general background and family planning situation, where appropriate and if it is…

Selected Bibliography of Educational Materials: Algeria, Libya, Morocco, Tunisia. Volume 3, Number 4, 1969.

ERIC Educational Resources Information Center

Azzouz, Azzedine; And Others

A 100-item bibliography with abstracts of books, newspaper articles, and periodical articles in English and French dating from 1953 offers information on various aspects of education in Algeria, Libya, Morocco, and Tunisia. Emphasis is placed on sections dealing with educational organization in primary, secondary, vocational and higher education;…

Selected Bibliography of Educational Materials: Algeria, Libya, Morocco, Tunisia. Volume 6, Number 2, 1972.

ERIC Educational Resources Information Center

Azzouz, Azzedine; And Others

Annotations of articles, written in English, provide the content for an annotated bibliography of educational materials written in French useful to those with an interest in North Africa. Sections on Algeria, Libya, Morocco, and Tunisia cover topics such as the philosophy and theory of education, educational organization, adult education, teacher…

Selected Bibliography of Educational Materials: Algeria, Libya, Morocco, Tunisia. Vol. 4 No. 3, 1970.

ERIC Educational Resources Information Center

Azzouz, Azzedine, Comp.; And Others

This report, part of a series of educational bibliographies from the Maghreb countries (Algeria, Morocco, and Tunisia) and Libya, consists of excerpts from periodicals published in those countries. Each entry is marked to indicate the particular country. The articles are organized under 13 major subjects that include: the structure of educational…

First report of Fusarium redolens causing Fusarium yellowing and wilt of chickpea in Tunisia

USDA-ARS?s Scientific Manuscript database

Chickpea plants showing wilt symptoms in Tunisia have been attributed solely to race 0 of Fusarium oxysporum f. sp. ciceris (Foc) in the past. However, chickpea cultivars known to be resistant to race 0 of Foc recently also showed the wilting symptoms. To ascertain the race or species identities re...

Detection of Rickettsia in Rhipicephalus sanguineus Ticks and Ctenocephalides felis Fleas from Southeastern Tunisia by Reverse Line Blot Assay

PubMed Central