Experimental and field studies on the viability of eggs, and the infectivity of third-stage larvae of the human hookworm Necator americanus recovered from the creek waters of the Niger Delta, Nigeria, and their epidemiological significance

Parasitology ◽  
1988 ◽  
Vol 96 (1) ◽  
pp. 111-117 ◽  
Author(s):  
J. K. Udonsi
Keyword(s):  
Fresh Water ◽  
Brackish Water ◽  
Niger Delta ◽  
Field Studies ◽  
Host Population ◽  
Water Contact ◽  
Necator Americanus ◽  
Brackish Waters ◽  
Significant Difference ◽  
Laboratory Cultures

SUMMARYIn a combined field and laboratory study, the eggs and 3rd-stage infective larvae of the human hookworm Necator americanus were recovered from the creek waters of the Niger Delta, Nigeria. They were tested for viability and infectivity. Eggs recovered from fresh water creeks showed a viability or hatching index of between 17·5 and 23·7%. Eggs recovered from brackish water showed a viability index of 18·8–21·4% in ‘normal’ cultures, and a maximum index of 6·3% when cultured in brackish water. The differences in the viability indices of these eggs were not significant (P > 0·05). Infective 3rd-stage larvae were recovered from both fresh creek water (205–258 L3/litre of water), and brackish water (45 L3/litre of water). Larvae hatched from brackish water eggs that were cultured in the brackish water were 20% infective by 3 days, but lost all infective potential by 7 days posthatching. Larvae from fresh water eggs, cultured in fresh water and ‘normal’ laboratory cultures reached 50% infectivity in 3–5 days, losing potential infectivity in 11–15 days posthatching. The infectivity patterns of larvae recovered directly from fresh and brackish waters did not differ significantly (P > 0·05) from the infectivity patterns of larvae recovered from laboratory cultures of eggs from all the experimental sources. Although larvae recovered directly from fresh and brackish waters survived in these respective media under laboratory conditions, there was a significant difference (P < 0·05) in their survival patterns. The survival and infectivity rates of field larvae were considerably reduced over time relative to control larvae. These results indicate that both contaminated fresh and brackish water creeks and their banks may form additional hookworm infection foci in areas where various water contact activities are carried out by the human host population.

scholarly journals Response of Water-Salt Migration to Brackish Water Irrigation with Different Irrigation Intervals and Sequences

Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2089 ◽  
Author(s):  
Zhu ◽  
Yang ◽  
Sun ◽  
Zhang
Keyword(s):  
Fresh Water ◽  
Brackish Water ◽  
Irrigation Treatment ◽  
Water Infiltration ◽  
Laboratory Simulation ◽  
Irrigation Interval ◽  
Significant Difference ◽  
Soil Desalination ◽  
The Mean ◽  
Irrigation Treatments

Establishing methods for scientific and rational use of brackish water resources is the key to farmland irrigation in the Yellow River Delta region of China. In this study, we conducted laboratory simulation experiments with soil columns and monitored the changes in water infiltration and salt distribution under eight irrigation treatments, including four intervals (0, 30, 60, and 90 min between irrigations) and two sequences (brackish-brackish-fresh water and brackish-fresh-brackish water). The results showed that the duration of water infiltration into the soil was higher under intermittent irrigation than continuous irrigation, with the highest value recorded at the 90-min irrigation interval. There was no significant difference in the mean soil water content between the brackish-brackish-fresh water (28.01–29.71%) and brackish-fresh-brackish water (28.85–29.98%) irrigation treatments. However, the mean soil desalination rate of the brackish-brackish-fresh irrigation treatment (42.51–46.83%) was higher than that of the brackish-fresh-brackish irrigation treatment (39.48–46.47%), and a much higher soil desalination rate was observed at the 90-min irrigation interval, compared with the other intervals. In conclusion, brackish-brackish-fresh water irrigation at longer time intervals (e.g., 90 min between irrigations) is conducive to reduce soil salt content in the surface soil in the study region.

The influence of salinity on Scirpus americanus tidal marshes in the St. Lawrence River estuary, Québec

1985 ◽  
Vol 63 (5) ◽  
pp. 920-927 ◽  
Author(s):  
J. Deschênes ◽  
J.-B. Sérodes
Keyword(s):  
Fresh Water ◽  
Lower Limit ◽  
Brackish Water ◽  
Saline Water ◽  
River Estuary ◽  
Considerable Effect ◽  
Tidal Marshes ◽  
Brackish Waters ◽  
Scirpus Americanus ◽  
St Lawrence River

The amount of sodium in the aboveground part of the stalks of Scirpus americanus taken at the peak of biomass is a good indicator of the amount of salinity in the waters flooding the tidal marshes of an estuary. In fresh water, the Na concentrations remain below 10 000 and then increase sharply up to 20 000 – 30 000 mg/kg in brackish waters. Even though this plant can grow under brackish conditions, salinity has a considerable effect on the percentage of submersion it can withstand. Consequently, in the presence of saline water, the lower limit of the vegetation regresses towards the shore. In the case of fresh water, Scirpus americanus occupies the lower part of marshes up to an average of 75% of submersion, while in brackish water it extends to about 35% and then disappears when waters are more saline.

scholarly journals Lignin-Containing Coatings for Packaging Materials—Pilot Trials

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1595
Author(s):  
Asif Javed ◽  
Peter Rättö ◽  
Lars Järnström ◽  
Henrik Ullsten
Keyword(s):  
High Speed ◽  
Water Solubility ◽  
Transmission Rate ◽  
Kraft Lignin ◽  
Packaging Materials ◽  
Water Contact ◽  
Pilot Trials ◽  
Significant Difference ◽  
Ph Level ◽  
Ammonium Zirconium Carbonate

One severe weakness of most biopolymers, in terms of their use as packaging materials, is their relatively high solubility in water. The addition of kraft lignin to starch coating formulations has been shown to reduce the water solubility of starch in dry coatings. However, lignin may also migrate into aqueous solutions. For this paper, kraft lignin isolated using the LignoBoost process was used in order to examine the effect of pH level on the solubility of lignin with and without ammonium zirconium carbonate (AZC). Machine-glazed (MG) paper was coated in a pilot coating machine, with the moving substrate at high speed, and laboratory-coated samples were used as a reference when measuring defects (number of pinholes). Kraft lignin became soluble in water at lower pH levels when starch was added to the solution, due to the interactions between starch and lignin. This made it possible to lower the pH of the coating solutions, resulting in increased water stability of the dry samples; that is, the migration of lignin to the model liquids decreased when the pH of the coating solutions was reduced. No significant difference was observed in the water vapor transmission rate (WVTR) between high and low pH for the pilot-coated samples. The addition of AZC to the formulation reduced the migration of lignin from the coatings to the model liquids and led to an increase in the water contact angle, but also increased the number of pinholes in the pilot-coated samples.

scholarly journals Content of inorganic solutes in lettuce grown with brackish water in different hydroponic systems

2017 ◽  
Vol 21 (3) ◽  
pp. 150-155 ◽  
Author(s):  
Alide M. W. Cova ◽  
Fabio T. O. de Freitas ◽  
Paula C. Viana ◽  
Maria R. S. Rafael ◽  
André D. de Azevedo Neto ◽  
...  
Keyword(s):  
Fresh Water ◽  
Nutrient Solution ◽  
Brackish Water ◽  
Dry Matter ◽  
Dry Matter Production ◽  
Matter Production ◽  
Water Plant ◽  
Hydroponic Systems ◽  
Inorganic Solutes

ABSTRACT The objective of this study was to evaluate the growth and accumulation of ions in lettuce grown in different hydroponic systems and recirculation frequencies. The experimental design was randomized blocks with 8 treatments and 4 replicates. The evaluated hydroponic systems were Nutrient Flow Technique (NFT) and an adapted Deep Flow Technique (DFT), the latter with recirculation frequencies of 0.25, 2 and 4 h. Both systems used fresh water and brackish water. Plant growth, accumulation of inorganic solutes (Na+, K+, Cl- and NO3-) and the correlation between dry matter production and Na+/K+ and Cl-/NO3- were evaluated. The salinity of the water used to prepare the nutrient solution caused decrease in growth and K+ and NO3- levels, and increased contents of Na+ and Cl- in the plants. When using fresh water the highest dry matter production was obtained in the NFT system. In case of brackish water the adapted DFT system increased the production, in relation to NFT system (at same recirculation frequency: 0.25 h). It was found that the choice of the type of hydroponic system and recirculation interval for the cultivation of lettuce depends on the quality of the water used to prepare the nutrient solution.

Gastrotricha from Italian brackish water environments with the description of a new species of Chaetonotus

1999 ◽  
Vol 79 (4) ◽  
pp. 585-592 ◽  
Author(s):  
P. Tongiorgi ◽  
E. Fregni ◽  
M. Balsamo
Keyword(s):  
New Species ◽  
Brackish Water ◽  
Systematic Sampling ◽  
Coastal Lakes ◽  
Brackish Waters ◽  
Freshwater Habitats ◽  
Sampling Programme ◽  
First Time ◽  
River Po ◽  
A New Species

During 1996–1997 a systematic sampling programme was carried out in brackish coastal lakes and lagoons and in the delta of the River Po. In six of the nine collecting locations, 12 species of Gastrotricha were identified. One species, Chaetonotus ichthydioides, is new to science; another three species, the chaetonotidans Heterolepidoderma foliatum and the macrodasyidans Dendrodasys ponticus and Turbanella cf. pontica, and one macrodasyidan genus, Paradasys (P. subterraneus), were found in Italy for the first time. The unusual morphology of some of the species identified shows that Gastrotricha colonized brackish waters from both marine and freshwater habitats.

scholarly journals Prevalence of Urinary Schistosomiasis among Almajiri Children in Silame, Sokoto State, North-western Nigeria

2021 ◽  
Vol 6 (1) ◽  
pp. 99-104
Author(s):  
S. M. Gamde ◽  
◽  
P. J. Tongvwam ◽  
K. Hauwa ◽  
A. M. Ganau ◽  
...  
Keyword(s):  
Demographic Data ◽  
Age Groups ◽  
Water Contact ◽  
Cross Sectional ◽  
Urinary Schistosomiasis ◽  
Public And Private ◽  
Significant Difference ◽  
Socio Demographic Factors ◽  
Age Range ◽  
North Western

Urinary schistosomiasis is a severe threat to global health with uncountable morbidities in Africa including Nigeria where control interventions focused on children in public and private schools neglecting Almajiri children. This undermined control interventions as those infected contaminate the environments with infective stages of the parasite. The objective of the study was to identify the prevalence of urinary schistosomiasis amongst Almajiri children in Silame, Sokoto State, North-western Nigeria. This was a cross-sectional descriptive study, socio-demographic data was collected in April 2020 on 206 consented Almajiri children in Silame and their urine samples were examined using the sedimentation method. The study showed a prevalence of 35.4% among the Almajiri children in Silame, Sokoto State, North-western Nigeria. The highest prevalence was found among children within the age range 16-20 years (63.6%) while the lowest prevalence was among those in the age range 6-10 years (24.4%). There was a statistically significant difference in the occurrence of urinary schistosomiasis between the age groups (χ 2 = 11.637a , df =3, p=0.002). Urinary schistosomiasis was prevalent among Almajiri children in the study area and parasite infection was associated with the participant's socio-demographic factors such as age, level of education, and water contact activities. Hence, the National Schistosomiasis Control Programs should incorporate the Almajiri children in the control interventions Keywords: Schistosoma hematobium infection; Makarantarallo;Almajiri;Silame

scholarly journals Impact of Irrigation with Saline Water on the Production of Tomato (Solanum lycopersicum) under Soilless and Traditional Techniques

2020 ◽  
pp. 1-14
Author(s):  
Alaa Ibrahim ◽  
Jamal Elfaki
Keyword(s):  
Solanum Lycopersicum ◽  
Brackish Water ◽  
Saline Water ◽  
Greenhouse Experiment ◽  
Biometric Data ◽  
Soilless Media ◽  
Saline Water Irrigation ◽  
Significant Difference ◽  
Salinity Levels

A greenhouse experiment was carried out to evaluate the response of tomato (Solanum lycopersicum) to saline water irrigation under soilless and traditional techniques. A special fertigation technique with two different salinity levels (1 dS m-1 and 4 dS m-1) of water was used under different soilless media, namely, perlite, gravel, and pozzolana as inert media, in addition to traditional techniques. Results showed that among the three soilless substrates, perlite medium produced the highest total yields with larger fruit sizes. Furthermore, the perlite medium enabled significant savings in water, compared to gravel (-15%) and pozzolana (-20%). Moreover, the results corroborated the existing knowledge on the tolerance of tomato to brackish water irrigation, since there was no significant difference in yield of plants grown in the soil irrigated with water with salinity levels of 1.1   dSm-1 and 4-5  dS m-1. Plant biometric data revealed a better and quicker development of plants grown in the soilless media compared to those grown in the soil, even in the case of freshwater irrigation.

scholarly journals Nutrient and inorganic solute (Na+ and Cl-) content in green onion plants under hydroponic cultivation using brackish water

2020 ◽  
Vol 44 ◽  
Author(s):  
Carlos Donato da Silva Souza ◽  
Geronimo Ferreira da Silva ◽  
Sirleide Maria de Menezes ◽  
José Edson Florentino de Morais ◽  
José Amilton Santos Júnior ◽  
...  
Keyword(s):  
Nutrient Solution ◽  
Brackish Water ◽  
Hydroponic System ◽  
Brackish Waters ◽  
Randomized Design ◽  
Hydroponic Cultivation ◽  
Salinity Levels ◽  
Completely Randomized Design ◽  
Harmful Effects ◽  
Different Levels

ABSTRACT Cultivation using brackish waters can result in nutritional and metabolic imbalances in several plant species, consequently reducing the production of dry matter (DM) and accumulation of toxic ions (Na+ and/or Cl-) in plants. We evaluated the DM production, and nutrient and inorganic solute (Na+ and Cl-) content in green onion plants (cv. Todo Ano Evergreen - Nebuka) under different levels of nutrient solution salinity in combination with circulation frequencies of this solution. Two experiments were conducted in a hydroponic system, using a completely randomized design, in a 6 × 2 factorial scheme, with five replicates: six levels of nutrient solution salinity (1.5, 3.0, 4.5, 6.0, 7.5, and 9.0 dS m-1) and two solution circulation frequencies (twice and thrice a day). In Experiment I, the evapotranspired depth was replaced using brackish water that was used to prepare each of the salinity levels (used exclusively), whereas in Experiment II, brackish water was used only to prepare each of the salinity levels and public water was used (electrical conductivity [ECw] = 0.12 dS m-1) for replacement in all treatments. The increase in the nutrient solution salinity reduced the production of DM and accumulation of nutrients; the reductions were more pronounced when brackish waters were used exclusively (Experiment I). However, the circulation of solutions thrice a day resulted in the harmful effects of the salinity effect. Replacing the evapotranspirated blade with water supply (Experiment II) mitigated the deleterious effects of salinity. Moreover, three circulations of the nutrient solution daily resulted in lower accumulation of inorganic Na+ and Cl- solutes and increased accumulation of nutrients N, P, K+, Ca2+, Mg2+, and S in the culture.

scholarly journals Anaplasma marginale Superinfection Attributable to Pathogen Strains with Distinct Genomic Backgrounds

2014 ◽  
Vol 82 (12) ◽  
pp. 5286-5292 ◽  
Author(s):  
Eduardo Vallejo Esquerra ◽  
David R. Herndon ◽  
Francisco Alpirez Mendoza ◽  
Juan Mosqueda ◽  
Guy H. Palmer
Keyword(s):  
High Throughput Sequencing ◽  
Anaplasma Marginale ◽  
Host Population ◽  
Content Type ◽  
Tropical Regions ◽  
Disease Epidemiology ◽  
Infectious Disease Epidemiology ◽  
Perfect Sequence ◽  
Significant Difference ◽  
High Prevalence

ABSTRACTStrain superinfection occurs when a second pathogen strain infects a host already infected with a primary strain. The selective pressures that drive strain divergence, which underlies superinfection, and allow penetration of a new strain into a host population are critical knowledge gaps relevant to shifts in infectious disease epidemiology. In regions of endemicity with a high prevalence of infection, broad population immunity develops againstAnaplasma marginale, a highly antigenically variant rickettsial pathogen, and creates strong selective pressure for emergence of and superinfection with strains that differ in their Msp2 variant repertoires. The strains may emerge either bymsp2locus duplication and allelic divergence on an existing genomic background or by introduction of a strain with a differentmsp2allelic repertoire on a distinct genomic background. To answer this question, we developed a multilocus typing assay based on high-throughput sequencing of non-msp2target loci to distinguish among strains with different genomic backgrounds. The technical error level was statistically defined based on the percentage of perfect sequence matches of clones of each target locus and validated using experimental single strains and strain pairs. Testing ofA. marginale-positive samples from tropical regions whereA. marginaleinfection is endemic identified individual infections that contained unique alleles for all five targeted loci. The data revealed a highly significant difference in the number of strains per animal in the tropical regions compared to infections in temperate regions and strongly supported the hypothesis that transmission of genomically distinctA. marginalestrains predominates in high-prevalence areas of endemicity.

Sign in / Sign up

Export Citation Format

Share Document