Germination response of Treculia africana (Dacne) seeds in relation to moisture content, storage method and its duration

Edible seeds of forest tree crop may be unavailable in sufficient quantity for tree planting projects and so there is need for storage. The germination response of Treculia africana seeds to storage method, duration and moisture content was investigated. Three storage methods were used namely; open basket, jute bag and air-right bottle. Moisture content over time under the storage regimes was investigated for five weeks while the storage aspect was monitored for 20 weeks. The experimental layout was completely Randomized design with threetreatments and three replications. Data was analysed using one way ANOVA at 5% level of significance. Fresh seeds had 100% germination. After first week of storage, this valued decreased to 73.3% and 83.3%, and drastically reduced to 3.3% and 13.3% for seeds stored in the open basket and jute bag respectively. The air-tight bottle maintained values of between 93.3-100% throughout the investigation period. There was statistical difference between storage method and duration. The moisture content of freshly extracted seeds was 36.95% and air-tight bottle maintained steady values were between 35.95 – 35.98%; the values for the open basket and jute bag dropped to 18.97 and 20.13% respectively within five weeks and the critical moisture content of < 24.16% was attained in three weeks after which there was no further germination. It is recommended that fresh seeds of T. africana be sown and where long term storage is needed, the air-tight bottle should be used, but resource poor farmers may employ the jute bag to store the seeds for only two weeks if seeds are meant for sowing. Further research is needed in getting appropriate storage devices for large scale storage of seeds for this important crop

Rooting potential of mature stem cuttings of some forest tree species for vegetative propagation

The growing of trees could be hindered by seed dormancy problems or unavailability of sufficient quantities of seeds, hence vegetative propagation using simple propagules like stem cuttings is a valued option especially for resource poor farmers. The rooting potential of mature stem cuttings of Gambeya albida, Irvingia gabonensis, Annona muricata, Garcinia kola and Triplochiton scleroxylon was investigated in a humid tent propagator without enhancement by artificial hormones. Propagation indicative parameters were estimated using percentages. G. kola had the highest root-ability indices with cutting survival rate of 85%, callus formation (75%), leaf loss (35%), days to axial bud sprout (55 days), days to leaf loss (23 days) and number of new leaves produced (9) at termination of study. T.scleroxylon had no survivals; an axial bud sprouted at 51 days but withered off by the third day. Other species were between these two extremes. Root-ability potential categorization for the species on the basis of this investigation was: easy to root for: G.kola and A.muricata, moderately easy to root for I.gabonensis and G.albida,unable to root for T.scleroxylon.The use of artificial hormone, juvenile stem cutting and somatic embryogenesis trials has been suggested especially for the moderately easy and unable to root categories

Investigation of the effect of seed coat treatment and open storage time on the germination and survival of Gambeya Albida g. Don seedlings.

Indigenous forest fruit trees like Gambeya albida play vital roles in the dietary diversity of the Nigerian people. The ever increasing rate of deforestation means their gradual disappearance, hence the need to examine appropriate seed sowing options for people interested in the crop. The study investigated the germination of Gambeya albida under different seed coat and open storage regimes in the nursery. The seed coat treatments were: decoated (CD), filed at circumference (FC) and untreated (CC). The seed moisture content was carried also out every three days ending in 22 days, while the investigation of seed germination was for 3 (three) months. Experimental layout for the germination study was randomized complete block design (RCBD), data was analysed using percentages, one-way ANOVA and means separation by Duncan Multiple Range test at 50% level of significance. The seed moisture content percentage study showed that fresh seeds of Gambeya albida had 43.21MC% which decline steadily with open storage time to 18.30% (critical moisture content) in 22 days. Time of storage affected the germination. The days of germination were between 11 –19 days for seed coat treatment regimes, was lowest for the (CD) and highest for (CC). The percentage germination was 5% (CD), 14.38% (FC) and 45% for (CC). Survival of emerged embryos that became seedlings was 12.5% (CD) 54.5% (FC) and 70.8% (CC). Seedcoat had significant protective role to play in the germination, early growth and survival of Gambeya albida seedlings. It is recommended that the seeds should be sown without seed coat removal in order to have good germination rate and survival.Keywords: Gambeya albida, germination, moisture content, seed coat, survival

Ecological effects of channelization on a tropical marine ecosystem: Impact on intertidal fish communities in the Cross River, Nigeria

The impact of bulk density silt/clay sedimentation from dredging in the Cross River Estuary (S. E. Nigeria) on fish was assessed through the use of community structural analysis and ecological procedures emphasizing reproduction and feeding characteristics. The distinction among the channel, creeklet and pool fish communities decreased as the percentage of silt/clay substrate increased. The abundance of benthic invertivore and herbivore fish groups declined significantly, as the percentage of silt increased for the channel fish dwellers. This is because the simple and lithophilous reproduction category requires clean and coarse substrates for spawning. All species affected by increased silt sedimentation within a guild were significantly  similar in trends of abundance. The ecological implication of these findings is the similar response of fish species of similar ecological niches to excessive turbidity

Outbreak of Middle East Respiratory Syndrome at Tertiary Care Hospital, Jeddah, Saudi Arabia, 2014

During March–May 2014, a Middle East respiratory syndrome (MERS) outbreak occurred in Jeddah, Saudi Arabia, that included many persons who worked or received medical treatment at King Fahd General Hospital. We investigated 78 persons who had laboratory-confirmed MERS during March 2–May 10 and documented contact at this hospital. The 78 persons with MERS comprised 53 patients, 16 healthcare workers, and 9 visitors. Among the 53 patients, the most probable sites of acquisition were the emergency department (22 patients), inpatient areas (17), dialysis unit (11), and outpatient areas (3). Infection control deficiencies included limited separation of suspected MERS patients, patient crowding, and inconsistent use of infection control precautions; aggressive improvements in these deficiencies preceded a decline in cases. MERS coronavirus transmission probably was multifocal, occurring in multiple hospital settings. Continued vigilance and strict application of infection control precautions are necessary to prevent future MERS outbreaks

Environmental and material controls on desiccation cracking in engineered clay embankments

PhD ThesisDesiccation cracking is a natural phenomenon commonly associated with drying of expansive soils. The role of cracks in surface permeability increase and overall deterioration of infrastructure slopes makes it a key factor in climate-related slope instability processes. Despite this significance, the controls on soil cracking in engineered slopes still represent a poorly understood area. In this study, soil cracking behaviour in clay embankments exposed to cyclic wetting and drying was investigated to improve understanding of this phenomenon for application in geotechnical practice. A complimentary field and laboratory study was undertaken, approaches commonly conducted in isolation in the literature. The field program involved direct investigation of natural crack development in a heavily instrumented, clay embankment (BIONICS, Newcastle University). Crack morphology parameters were quantified under engineering, meteorological and near surface soil hydrological conditions to understand how temporal change influences these. Laboratory experimentation was carried out on materials representative of typical embankment fills and construction methods in the UK in a bespoke climate control system. Time series photographs of the crack networks were analysed using image processing technique to compare their intensities across the experimental conditions. Syntheses of field and laboratory results show the influence of factors related to the embankment geometry (i.e. slope aspect, layer thickness), material properties (i.e. soil density and plasticity) and environmental condition (i.e. wetting and drying cycles) on the cracking behaviour in engineered clay slopes. The sensitivity of cracking intensity under given climate conditions critically relates to the rate of moisture loss and the material strength. Overall, this research presents how newly gained understanding of cracking can potentially impact upon improved construction techniques of engineered clay embankments and the susceptibility of historic embankments constructed to lower densities to climatic changes, including how drying/wetting cycles can exacerbate crack development.Akwa Ibom State University, TETFUN

Seismic Refraction Profiling For Groundwater in a Basement Terrain: The Case of Akamkpa, Southeast Nigeria.

Weathering induces secondary porosity on (otherwise) crystalline basement rocks; forming a wide range of regolith. Groundwater accumulates at the base of this regolith and the thicker the regolith, the higher the possibility of locating groundwater occurrence. Nine (9) seismic refraction profiles were survey using the hammer-plate striking system in various parts of Akamkpa with the intent of locating aquifers. The interpretation of the time – distance graph reveal a typical two layer model. The top layer, with mean seismic velocity of 931m/s with thickness between 3.39m and 19.23m from the surface is within the range of velocities for loose and porous material whereas, the lower layer with mean seismic velocity of 2284m/s compares well with those of fissured to fresh (transitional) basement rocks. This shows that the weathered overburden material of the basement complex is thick enough (3.39 – 18.23m) to support shallow to medium depth borehole development in the area. Keywords: Basement, Porosity, Regolith, Seismic Velocity, Weathering

Effect of crude oil extracts on early stages of African catfish Heterobranchus longifilis (val.) reared under controlled condition

Eggs and larvae of Heterobranchus longifilis were exposed to extracts of different concentrations of Nigerian Bonny light crude oil and Exxon Mobil Oso off-shore condensate during a comparative toxicity experiment carried out in the Institute of Oceanography Fish Farm, University of Calabar, Nigeria. Petroleum hydrocarbon was extracted from the two oils in separate 30litre glass aquaria and the eggs and young larvae were contaminated by exposing them to three concentrations of both oils, viz: 101, 103, 102ppm for approximately 10 days. Young eggs seemed to be more sensitive from 5 to 30 hours after fertilization. Extract from 104 ppm of Bonny Light Crude and Oso condensate caused 40% and 30% mortality respectively, after 100h. Embryos contaminated with Bonny Light crude extract did not recover on transfer to clean water. Delayed development was observed in the two-highest concentrations. Heterobranchus longifilis larvae were found to have a “mean critical time” of 4.2 days in the highest concentration of Oso condensate extract when larval integument was damaged. It is concluded that Bonny light crude could be a more dangerous pollutant to juvenile fish than the Oso condensate.KEYWORDS: Heterobranchus longifilis, crude Oil extracts, Mortality, Bonny Light Crude, Exxon MobilOso Condensate

Impact Of Crude Oil On Recruitment Of Epibenthic Organisms In Cross River Estuary, South East Nigeria

Effects of crude oil on recruitment of epibenthic organisms in Cross River estuary were studied in February and March, 2007 on wooden Panels (15×15×1.5cm). The panels were immersed in Nigerian light crude oil and later suspended in the estuary for six weeks. Rhizoclonium hieroglyphicum showed slight resistance to the effect of the crudeoil while species like Balanus balanoide, Crassostrea gazar, Bugula neritina, Serbellaria intoshi, Catenella opuntia and Caloglossa leprieurii showed slight inhibition. Statistically, there was however no significant difference in the recruitment level of the organisms on both the control panels and oil-polluted panels, (p>0.05). This may probably have been as a result of weathering process or bacterial degradation of the crude oil which rapidly diluted the hydrocarbon, thereby reducing its toxicity. The result reveals that widespread oil spill during the reproductive season would reduce larval settlement and impede subsequent recruitment. The ecological implications of these findings arediscussed