scholarly journals The Abundance and Biting Patterns of Culex quinquefasciatus Say (Culicidae) in the Coastal Region of Nigeria

ISRN Zoology ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Emmanuel C. Uttah ◽  
Gloria N. Wokem ◽  
Christiana Okonofua
Keyword(s):  
Culex Quinquefasciatus ◽  
Rainy Season ◽  
Coastal Region ◽  
Dry Season ◽  
Human Landing Catch ◽  
Light Traps ◽  
Transmission Potential ◽  
Human Landing ◽  
The Mean

This study was aimed at determining the abundance and biting patterns of Culex quinquefasciatus in the coastal region of Nigeria. Collections were done by human landing catch and by CDC miniature light traps from September 2005 to August 2006. A total of 3798 C. quinquefasciatus females were collected. The highest number of females was caught in the month of August and it represented nearly a quarter (24.0%) of the total females collected. In all, 38.8% of females dissected were parous. The abundance of C. quinquefasciatus followed the pattern of rainfall with the population starting to expand at the onset of the rains. The highest increase was found after the temperature had peaked. The mean of biting was 3.2 times more in the rainy season than in the dry season, whereas the transmission potential was higher in the dry season. C. quinquefasciatus is presently regarded as a biting nuisance having no significant epidemiological importance yet. Efforts at its control should be intensified before it is too late.

scholarly journals Filariasis Control in Coastal Nigeria: Predictive Significance of Baseline Entomological Indices of Anopheles gambiae s.l. (Diptera: Culicidae)

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Emmanuel C. Uttah ◽  
Dominic Ibe ◽  
Gloria N. Wokem
Keyword(s):  
Anopheles Gambiae ◽  
Rainy Season ◽  
Light Trap ◽  
Control Programme ◽  
Dry Season ◽  
Human Landing Catch ◽  
Transmission Potential ◽  
Biting Rate ◽  
Human Landing ◽  
Anopheles Gambiae S.L

This work aimed at collecting filariasis transmission data of Anopheles gambiae to be used in predicting future trends in filariasis transmission and control programme outcomes. Collection of the mosquitoes was made by human landing catch and light trap methods. In all, 5,813 females were caught from September 2005 to August 2006. Mosquito population started to expand at the onset of the rains. The highest density was found after peak temperature. The A. gambiae s.l. biting peaked around midnight; 39.7% were parous and 0.3% were infective. The highest percentage of parous females caught was near midnight, ranging between 42.0% and 47.5% from 22.00 to 03.00 hours. Biting rate in the rainy season was 2.6 times higher than it in the dry season. Transmission potential was 3.6 times higher during the rains than during the dry season. The percentage infectivity was relatively high (13.2%) in June, corresponding to 8.8 infective bites per person per month. All infective A. gambiae, were caught between 22.00 and 03.00 hours. The average load of L3 larvae per infective A. gambiae was 1.4 L3/mosquito. The monthly transmission potential calculated for each month indicated that transmission was ongoing for most of the months of the year, especially in the rainy season.

scholarly journals New Records of Anopheles benarrochi B (Diptera: Culicidae) in Malaria Hotspots in the Amazon Regions of Ecuador and Peru

2021 ◽  
Author(s):  
Diego Morales Viteri ◽  
Manuela Herrera-Varela ◽  
Maribel Albuja ◽  
Cristina Quiroga ◽  
Gloria Diaz ◽  
...  
Keyword(s):  
Vector Control ◽  
Malaria Transmission ◽  
New Records ◽  
Final Analysis ◽  
Human Landing Catch ◽  
Light Traps ◽  
Control Units ◽  
Pcr Rflp ◽  
Human Landing ◽  
First Time

Abstract The increase in malaria transmission in the Amazon region motivated vector control units of the Ministry of Health of Ecuador and Peru to investigate Anopheles (Diptera: Culicidae) species present in transmission hotspots. Mosquitoes were collected using prokopack aspirators and CDC light traps (Ecuador) and human landing catch in Peru. In Ecuador, 84 Anopheles were captured from Pastaza, Morona Santiago, and Orellana provinces and identified morphologically [An. (An.) apicimacula Dyar and Knab, An. (Nys.) near benarrochi, An. (Nys.) near oswaldoi, An. (Nys.) near strodei, An. (An.) nimbus (Theobald, 1902), and An. (Nyssorhynchus) sp.]. In Peru, 1,150 Anopheles were collected in Andoas District. A subsample of 166 specimens was stored under silica and identified as An. near oswaldoi, An. darlingi, and An. (An.) mattogrossensis Lutz and Neiva. COI barcode region sequences were obtained for 137 adults (107 from Peru, 30 from Ecuador) identified by ITS2 PCR-RFLP as An. benarrochi Gabaldon, Cova Garcia, and Lopez and retained in the final analysis. Haplotypes from the present study plus An. benarrochi B GenBank sequences grouped separately from Brazilian An. benarrochi GenBank sequences by 44 mutation steps, indicating that the present study specimens were An. benarrochi B. Our findings confirm the presence of An. benarrochi B in Ecuador and reported here for the first time from the Amazonian provinces of Orellana and Morona Santiago. Furthermore, we confirm that the species collected in Andoas District in the Datem del Maranon Province, Peru, is An. benarrochi B, and we observed that it is highly anthropophilic. Overall, the known distribution of An. benarrochi B has been extended and includes southern Colombia, much of Peru and eastern Ecuador.

Stable Isotopes Analysis of Precipitation in Subtropical Plateau of Yunnan

2014 ◽  
Vol 1010-1012 ◽  
pp. 1059-1063
Author(s):  
Wei Guan ◽  
Tao Fan ◽  
Xiu Qin Zhu
Keyword(s):  
Stable Isotopes ◽  
Rainy Season ◽  
Mean Value ◽  
Dry Season ◽  
Precipitation Line ◽  
Stable Isotopic ◽  
Different Seasons ◽  
Geographical Position ◽  
The Mean ◽  
The Relationship

To elucidate the relationship between stable isotopes of precipitation (SIP) and the extreme drought in Kunming area, based on the stable isotopes data of the GNIP in Kunming site from 1986 to 2003, the precipitation line equation is brought forward and the seasonal change rule of stable isotopes are discussed. The stable isotopic compositions of precipitation exhibit great diversities in different seasons during to influences of multiple factors, such as monsoon, rainfall amount moisture source and others. The δ18O values in rainwater exhibit significant seasonal variations, the average of-10.12‰ in rainy season, the dry season is-4.5‰, having lower values in the rainy season and higher one in the dry season. The amount effect of precipitation is very distinct, that concealed the temperature effect. Got the special geographical position,dvalues present unique characteristics, the average ofdvalues is 10.78‰ in rainy season, and is 4.86‰ in dry season, the mean value is generally lower than most parts of the world.

Nocturnal Mosquitoes of Pará State in the Brazilian Amazon: Species Composition, Habitat Segregation, and Seasonal Variation

2020 ◽  
Vol 57 (6) ◽  
pp. 1913-1919
Author(s):  
Walter Santos de Araújo ◽  
Thallyta Maria Vieira ◽  
Guilherme Antunes de Souza ◽  
Isaque Clementino Bezerra ◽  
Paulo Henrique Costa Corgosinho ◽  
...  
Keyword(s):  
Culex Quinquefasciatus ◽  
Disease Transmission ◽  
Rainy Season ◽  
Mosquito Species ◽  
Species Abundance ◽  
Abundant Species ◽  
Dry Season ◽  
Habitat Segregation ◽  
Vector Species ◽  
High Degree

Abstract Mosquitoes (Diptera: Culicidae) are one of the most important disease vector species in the world. Many species have a high degree of anthropophilia and are often found in human habitations. In the present study, we have inventoried the nocturnal mosquito assemblage in intra-, peri-, and extradomicile environments in four municipalities in Pará, Brazil. At each municipality, a residence was selected and the mosquitoes were sampled using the protected human attraction capture and Shannon trap methods in April (rainy season) and August 2018 (dry season). We have collected a total of 696 mosquito specimens belonging to 8 genera and 17 species. The most abundant species were Mansonia (Mansonoides) titillans (Walker) (366/696, 52.6%), Anopheles (Nyssorhynchus) albitarsis Lynch-Arribálzaga (97/696, 13.9%), and Culex (Culex) quinquefasciatus Say (93/696, 13.4%). Mosquito richness, abundance, and composition did not differ between intra-, peri-, and extradomicile environments suggesting limited habitat segregation among the different species. However, mosquito species richness and mosquito species abundance were significantly higher during the rainy season than during the dry season, suggesting increased mosquito activity during the rainy season. We detected several important vector species of human diseases including Aedes (Stegomyia) aegypti (Linnaeus), Anopheles (Nyssorhynchus) darlingi Root, Haemagogus (Conopostegus) leucocelaenus (Dyar and Shannon), Coquillettidia (Coquillettidia) venezuelensis (Theobald), and Culex (Culex) quinquefasciatus which are the main transmitters of dengue, malaria, yellow fever, mayaro, and oropouche fever, respectively. As inventories of disease-carrying mosquitoes in the region are very scarce, mainly in residential environments, our results suggest high potential for mosquito-borne disease transmission in Pará State.

Seasonal movements of giraffes in Niger

1999 ◽  
Vol 15 (3) ◽  
pp. 341-353 ◽  
Author(s):  
Yvonnick Le Pendu ◽  
Isabelle Ciofolo
Keyword(s):  
Rural Communities ◽  
Rainy Season ◽  
Dry Season ◽  
Home Ranges ◽  
Spatial Behaviour ◽  
Long Distance ◽  
Mean Size ◽  
The Mean ◽  
Niger River ◽  
Hydrographic Network

The last population of giraffes in west Africa lives in Niger in an unprotected Sahelian region inhabited by farmers and herders. The spatial behaviour of each individual of the population (n = 63) was studied by direct observation during 15 mo. Two-thirds of the population were resident in the tiger bush in the rainy season and in the nearby area of Harikanassou, a sandy agricultural region, in the dry season. Rainy season and dry season home ranges were mutually exclusive and individual home ranges were overlapping when considering one season (rainy season: 84%; dry season: 67%). The mean size of the seasonal home ranges of these resident giraffes during the dry season (90.7 km2) was twice the mean size during the rainy season (46.6 km2). A third of the population moved 80 to 200 km in three directions, and two giraffes from an isolated group from Mali moved 300 km along the Niger River. Long distance movements of such length have never been reported before, and several explanations are proposed: previous distribution, social transmission, hydrographic network and food availability, poaching events. The giraffes in Niger do not avoid rural communities; indeed, they live in densely populated regions. Furthermore, their movements, synchronized with human activities in these regions, are representative of life conditions in the Sahel.

scholarly journals Caatinga Albedo Preserved and Replaced by Pasture in Northeast Brazil

Atmosphere ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1622
Author(s):  
Alcindo Mariano Souza ◽  
Cláudio Moisés Santos e Silva ◽  
Bergson Guedes Bezerra
Keyword(s):  
Rainy Season ◽  
Early Morning ◽  
Dry Season ◽  
Pasture Management ◽  
Seasonally Dry ◽  
Temperature And Precipitation ◽  
Local Standard ◽  
The Mean ◽  
Dry And Rainy Seasons

The caatinga is considered South America’s largest seasonally dry tropical forest (SDTF) and one of the most vulnerable endemic biomes in relation to climate change. The surface albedo in caatinga is relevant to understanding the role of this biome in the climate of the Northeast region of Brazil. Thus, a comparative analysis was conducted between the albedos of preserved and anthropized caatinga (pasture). Data were collected using CNR4-type net radiometers during the dry and rainy seasons. The mean albedo values were higher in the Pasture both in the dry and rainy season, with values of 0.181 and 0.177, respectively. In the caatinga, the mean albedo values were 0.137 in the dry season and 0.146 in the rainy season. The hourly average values for albedo, taken between 6:30 a.m. and 4 p.m., with intervals of 30 min, were also higher in the pasture. For convenience, this study uses local standard time (LST), which is 3 h behind from coordinated universal time (UTC). The greatest dispersions in the frequencies of the mean hourly albedo values occurred in the early morning and late afternoon. Some of the consequences of this study is the confirmation that there is an increase in albedo in caatinga replaced by pasture and this causes a reduction in the net radiation and also the finding that a region where there is adequate pasture management also enables albedo management and from solar radiation. And that further studies can indicate the impacts on temperature and precipitation, especially in warmer periods during the dry season.

RADIAL GROWTH DYNAMICS OF TABEBUIA UMBELLATA (BIGNONIACEAE), A FLOOD-TOLERANT TREE FROM THE ATLANTIC FOREST SWAMPS IN BRAZIL

IAWA Journal ◽  
2004 ◽  
Vol 25 (2) ◽  
pp. 175-183 ◽  
Author(s):  
Cátia Henriques Callado ◽  
Sebastião José da Silva Neto ◽  
Fábio Rubio Scarano ◽  
Cecília Gonçalves Costa
Keyword(s):  
Atlantic Forest ◽  
Rainy Season ◽  
Radial Growth ◽  
Growth Dynamics ◽  
Dry Season ◽  
Annual Growth ◽  
Mature Leaves ◽  
Tolerant Species ◽  
The Mean

We studied the annual radial growth of Tabebuia umbellata (Sond.) Sandwith (Bignoniaceae) and its relationship to rainfall, temperature, photoperiod, flooding and phenology. This species showed cyclic annual growth. Growth was the greatest during the rainy season and flooding. Growth was associated with the presence of mature leaves on the trees. No increase in girth was observed during the dry season or during defoliation or flowering. The mean rate of radial growth was c. 6 mm/year. This flood-tolerant species maintained and increased radial growth during flooding.

scholarly journals Export of materials along a tidal river channel that links a coastal lagoon to the adjacent sea

2012 ◽  
Vol 60 (3) ◽  
pp. 311-322 ◽  
Author(s):  
Javier Aldeco Ramírez ◽  
Martha Signoret Poillon ◽  
María Adela Monreal Gómez ◽  
David Alberto Salas de León
Keyword(s):  
Chlorophyll A ◽  
Coastal Lagoon ◽  
Rainy Season ◽  
Dry Season ◽  
Tidal River ◽  
Tidal Channel ◽  
Effective Mechanism ◽  
Maximum Current ◽  
Tidal Velocity ◽  
The Mean

Intratidal variability and flux of salt, chlorophyll-a and suspended materials were evaluated in a shallow tropical tidal channel linking a coastal lagoon to the western Gulf of Mexico. Velocity, temperature and conductivity were used to calculate the fluxes. Data were recorded during three tidal velocity cycles (tvc) under extreme river discharge conditions. Chlorophyll-a and suspended materials were determined below the surface. In both seasons (dry and rainy), the flow was ebb-dominated and with longer duration than when in flood. Maximum current velocities were 0.30 m s-1 in May (dry season) and 0.60 m s-1 in September (rainy season). In the dry season the mean chlorophyll-a export was of 7.56 Kg over tvc while the import was of 3.32 Kg. In the rainy season mean export (47.3 Kg) was 6 times greater than the import (7.93 Kg over tvc). Phytoplankton was dominated by organisms of marine origin. The mean of exported, suspended materials in the rainy season (111.3 Kg) was 4.6 times greater (859 Kg) than that in the dry season (184.7 Kg over tvc). Tidal velocity asymmetry is an effective mechanism of exportation, introducing relatively warm and saltier water into the river through the tidal channel.

scholarly journals Assessment of Air Pollution in Gboko, Benue State, Nigeria

2020 ◽  
Vol 3 (4) ◽  
pp. p38
Author(s):  
Bernard Tarza Tyubee ◽  
Grace Hembadoon Yiyeh ◽  
Monday Akpegi Onah
Keyword(s):  
Air Pollution ◽  
Rainy Season ◽  
Air Pollutants ◽  
Dry Season ◽  
Land Use Land Cover ◽  
The Mean ◽  
Spatio Temporal ◽  
Town Center ◽  
The Town ◽  
Mean Concentration

The study assessed the spatio-temporal and seasonal variation in the concentration of CO, NO2­, SO2 and PM10 in Gboko, Benue State, Nigeria. Data on the air pollutants were collected at four points between 8:00am-10:00am and 3:00pm-5:00pm daily, from 16th January to 24th February (dry season) and 5th June to 14th July (rainy season) in 2017 using Gasman hand-held gas monitors. Data were analysed using mean, coefficient of variation (CV) and Analysis of Variance (ANOVA). The result showed highest and lowest mean concentrations of CO of 21.86ppm (rainy season) and 17.00ppm (dry season) in the town center (Point 2, GBKC) and 2.46ppm (rainy season) and 2.45ppm (dry season) in the suburb (Point 1, YRA). The mean concentrations of CO, NO2 and SO2 were higher in rainy season, and the mean concentration of PM10 was higher in dry season, with the mean concentrations of NO2, SO2 and PM10 higher than the national acceptable levels in both seasons. The spatial variation in concentration of the air pollutants was significant with respect to land use/land cover types than seasons. There should be regular monitoring of air quality as the population and human activities increase in the town.

scholarly journals Multi-Drug Resistant and Plasmid-Mediated Quinolone-Resistant Salmonella enterica isolated from Shellfish in Iko Creek, Nigeria

2019 ◽  
pp. 1-8
Author(s):  
Udoekong, Nsikan S. ◽  
Akan, Otobong D. ◽  
James, Iniobong I. ◽  
Agbo, Bassey E. ◽  
Umoh, Anthony
Keyword(s):  
Salmonella Enterica ◽  
Rainy Season ◽  
Dry Season ◽  
Multi Drug Resistance ◽  
Rrna Gene ◽  
Drug Resistant ◽  
The Mean ◽  
One Year ◽  
Phenotypic Methods ◽  
Susceptibility Profiles

Aim: This study investigated the occurrence of multi-drug resistant (MDR) and Plasmid-Mediated Quinolone Resistant (PMQR) genes in Salmonella enterica isolated from shellfish in Iko Creek, Nigeria. Study Design: This is an experimental research that studied Salmonella enterica isolated from shellfish to determine its association with MDR and PMQR using standard microbiological and molecular methods. Place and Duration of Study: The study was carried within Iko Creek, South-South Nigeria for a period of one year (March-July and August to February 2017). Methodology: A total of 160 shellfish samples (80 clams and 80 oysters) were analyzed for the presence of Salmonella enterica using standard bacteriological methods. In all, 22(52.4%) were positive for clams while 20(47.6%) for oysters. The bacterium was identified using phenotypic methods. The antibiotics used for the antibiotic susceptibility profiles were amoxicillin, quinolones, aminoglycosides, macrolide and sulfonamide. Confirmation of the isolates was done by DNA sequencing of 16S rRNA gene; results obtained were then compared with that in the gene bank. The isolate was identified as Salmonella enterica. Results: The mean heterotrophic bacterial counts (THBC) in clams ranged from 5.25 x 106 to 3.71 x 107 (Cfu/g) in the dry season and 3.05 x 106 to 2.33 x106 (Cfu/g) in the rainy season. The mean THB counts in oyster was 3.27 x 108 to 1.59 x 108(Cfu/g) in the dry season and 2.54 x 107 to 4.39 x 106 (Cfu/g) in the rainy season. Salmonella enterica showed resistance to all the antibiotics tested except gentamicin. Seventy-one (71) percent of the isolates in this study expressed the qnrB genes. Conclusion: The presence of qnr B genes and multi-drug resistance (MDR) in the isolate’s gene according to this study is an indicator of treatment failure with antibiotics.

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