Heavy Metals Concentration In Soils And Bioaccumulation In Earthworm (Lumbricus Terrestris) At Lemna Solid Wastes Dumpsite, Calabar, Cross River State

This study investigated the concentrations of heavy metals and their bioaccumulation in earthworm in Lemna solid wastes dumpsite in Calabar, Cross River State, Nigeria. Three composite samples of the depth of 30 cm each were collected from Lemna dumpsites and control from the University of Calabar Botanical garden, making a total of four composite soil samples, while samples of earthworms were collected at each sampling point. The samples were analysed for Pb, Cd, Zn and Cu. The result showed that the levels of heavy metals were all higher in dumpsite and significantly different from the control. The respective means of metal concentrations from both Lemna and control were Pb(323.99mg/kg , 89.88mg/kg),  Cd(1.12 mg/kg, 0.072 mg/kg), Zn(281 mg/kg, 7.60 mg/kg) and Cu(21.58 mg/kg, 4.89 mg/kg). Pb, Cd, Zn and Cu were also higher in earthworm of dumpsite than earthworm of the control soil. Correlation between Cadmium and Zinc concentration in soil and Cadmium and Zinc concentration in earthworm displayed strong and positive relationship while weak and negative correlation was observed between Cu and Pb concentrations in soil and Cu and Pb concentrations in earthworm. Bioaccumulation of the heavy metals by earthworm was in the order of Zn (0.382) > Cd (0.170) > Pb (0.076) > Cu (0.020). The dumpsite soil was found to be contaminated with Cd, Pb and Zn as their concentrations were high above maximum permissible limits except Cu.  For safe consumption of crops from Lemna dumpsite soil, remediation of heavy metals in the soil in advocated.   &nbsp

Properties of soils of different lithology in the humid tropics of southeastern nigeria

This study evaluated the properties of soils developed on diverse parent materials in Ogoja Local Government Area. Five profile pits on five different parent materials were dug, morphologically delineated and described. The five parent materials were basement complex (BC), mudstone (MS), sandstone (SS), shalestone (SH) and limestone (LS). Morphologically, the soils were deep with varying color, structure, texture and consistency. The results of chemical analyses revealed that the soils have acid pH with means of 5.4, 5.4, 5.4, 5.3 and 5.4 in BC, MS, SS, SH and LS. Organic carbon was low (<15g/kg) across the parent materials while total N was slightly higher in MS, SS and LS with means of 0.04 g kg-1, 0.10 g kg-1, 0.04 g kg-1, 0.10 g kg-1  and 0.20 g kg-1  in BC, MS, SS, SH and LS accordingly. Available P was low (<8mg/kg) across the parent materials with slightly higher value recorded in SH than in other parent materials. Calcium and sodium were the dominant and the least bases respectively with mean values of 3.2 cmol/kg, 3.93 cmol/kg, 3.65 cmol/kg, 3.3 cmol/kg and 3.95 cmol/kg and 0.25 cmol/kg, 0.10 cmol/kg, 0.08 cmol/kg, 0.08 cmol/kg, 0.08 cmol/kg in BC, MS, SS, SH and LS respectively. Exchangeable bases were higher in MS than other soils. Both Al3+ and H+ contributed at the same level to acidity of the soils. Correlation analysis showed that sand correlated negatively and significantly with clay (-0.81), OC (-0.41), TN (-0.42), and Al+++ (-0.78) and positively and significantly with pH (0.72), Ca2+ (0.7), Mg2+ (0.64), K+ (0.56), ECEC (0.71) and BS (0.70).  Correlation between pH and exchangeable bases, available P (0.83), ECEC (0.9) and base saturation (0.83) was significant and positive.  However, most properties had negative and non-significant correlation with each other

Cube law, condition factor and weight-length relationships: history, meta-analysis and recommendations

This study presents a historical review, a meta-analysis, and recommendations for users about weight–length relationships, condition factors and relative weight equations. The historical review traces the developments of the respective concepts. The meta-analysis explores 3929 weight–length relationships of the type W = aLb for 1773 species of fishes. It shows that 82% of the variance in a plot of log a over b can be explained by allometric versus isometric growth patterns and by different body shapes of the respective species. Across species median b = 3.03 is significantly larger than 3.0, thus indicating a tendency towards slightly positive-allometric growth (increase in relative body thickness or plumpness) in most fishes. The expected range of 2.5 < b < 3.5 is confirmed. Mean estimates of b outside this range are often based on only one or two weight–length relationships per species. However, true cases of strong allometric growth do exist and three examples are given. Within species, a plot of log a vs b can be used to detect outliers in weight–length relationships. An equation to calculate mean condition factors from weight–length relationships is given as Kmean = 100aLb−3. Relative weight Wrm = 100W/(amLbm) can be used for comparing the condition of individuals across populations, where am is the geometric mean of a and bm is the mean of b across all available weight–length relationships for a given species. Twelve recommendations for proper use and presentation of weight–length relationships, condition factors and relative weight are given

Modern Technological Options Rectification Separation Of Hydricarbon-oxygenate Blends

The aim of this study is to explore the technological options distillation broad hydrocarbon fractions of different origin in the search for energy-saving environmental conservation technologies in the production of the hydrocarbon fraction of the material and raw materials of various origins including the recycling and reprocessing of heavy oil residues as liquid hydrocarbons are formed during coking of petroleum residues. n the results of analytical studies focused on dry method and technology of petroleum distillates hydrocarbon-oxygenate blends in different origins seem to evidence-based possibility of intensifying mass transfer processes by replacing the traditional stripping agent in the hydrocarbon vapors in a distillation column which allows to save heat and energy costs

Hydraulic Properties of Soils of Akani Esuk Orok in Calabar, Cross River State, Nigeria

The study highlights the hydraulic properties of Akani Esuk Orok in Calabar, Cross River State, Nigeria. Twenty soil samples were collected from Akani Esuk in Calabar on a grid measuring 6 m X 6 m at a distance of 2 m apart to determine the hydraulic conductivity and to assess its influence on bulk density, particle density, total porosity and texture. The mean value of hydraulic conductivity was 14. 91cmhr-1, bulk density1.3 g cm-3, particle density 2.5 g cm-3, total porosity 47.6 %, sand content 80.1 %, silt content 8.4 % and clay content 11.5 %. The texture of the experimental plot was loamy sand. The mean values of pH were 5.4; effective cation exchange capacity (ECEC) was 63.9 cmol kg-1.These values, which are rated medium for the soils are probably responsible for the luxuriant growth of several crops cultivated in the area. The mean base saturation of the soils was 58.3 %. The potassium level of the study area was low, a mean value of 0.11 2 mg kg-1. Though the soils were strongly acidic in reaction and the fertility status was considered low, medium and high taking consideration values of organic carbon, total nitrogen, ECEC and base saturation. Hence, the fertility should be maintained by planting Calopogonium municoides, Centrosema pubescens and adoption of appropriate cultural practices

Morphological and Physicochemical Properties of Basaltic Soils on a Toposequence in Ikom, South Eastern Nigeria

Three profile pits were sunk along a toposequence of basaltic soils in Ikom, Cross River State to determine their morphological and physicochemical properties. The profile pits were morphologically described and thirteen (13) soil samples were collected from different horizons of the profiles for physicochemical analysis. Morphologically, the soils were deep and well drained with no concretions. The colour of the surface soils varied between dark reddish gray (5YR4/2) and dark brown (7.5YR 3/2) to dark reddish brown (5YR 3/4), while that of the subsurface varied between red (2.5YR 4/6) to reddish brown (2.5YR 4/4). The soils had sub-angular blocky structure of different grades and classes with predominantly clayey texture in the Ap horizons and very gravelly clayey texture in the Crtg horizons. The chemical analysis revealed that exchangeable Ca2+ was the most dominant cation amongst the exchangeable bases. The soils were low in total nitrogen, organic carbon, available phosphorus and very high in base saturation. The study showed that the soils are moderately fertile and as such, a lot has to be done to improve their fertility status through the application of organic and inorganic fertilizers with good management practices such as mulching with crop residue after harvest, sowing of crops at low density per hectare, conservative tillage, strip cropping, crop rotation and shifting cultivation to ensure sustainable productivity

Survey of type 6 group variants of hepatitis C virus in Southeast Asia by using a core-based genotyping assay

Previous surveys of the prevalences of genotypes of hepatitis C virus (HCV) in different populations have often used genotyping assays based upon analysis of amplified sequences from the 5' noncoding region (5'NCR), such as restriction fragment length polymorphism (RFLP) or hybridization with type- specific probes (e.g., InnoLipa). Although highly conserved, this region contains several type-specific nucleotide polymorphisms that allow major genotypes 1 to 6 to be reliably identified. Recently, however, novel HCV variants found in Vietnam and Thailand that are distantly related to the type 6a genotype (type 6 group) by phylogenetic analysis of coding regions of the genome often have sequences in the 5'NCR that are similar or identical to those of type 1 and could therefore not be identified by any assay of sequences in this region. We developed a new genotyping assay based upon RFLP of sequences amplified from the more variable core region to investigate their distribution elsewhere in southeast (SE) Asia. Among 108 samples from blood donors in seven areas that were identified as type 1 by RFLP in the 5'NCR, type 6 group variants were found in Thailand (7 from 28 samples originally identified as type 1) and Burma (Myanmar) (1 of 3) but were not found in Hong Kong (n = 43), Macau (n = 8), Taiwan (n = 6), Singapore (n = 2), or Malaysia (n = 18). Although this small survey suggests a relatively limited distribution for type 6 group variants in SE Asia, larger studies will be required to explore their distribution in other geographical regions and the extent to which their presence would limit the practical usefulness of 5'NCR-based genotyping assays for clinical or epidemiological purposes.link_to_subscribed_fulltex