Preventive and Remedial Measures to House Termite Infestations in Two Ikwerre Communities of Rivers State, Port Harcourt, Nigeria

From forests to human dwellings, infestations of woods by termites are on the increase. Despite the increasing occurrences of termite infestations in human dwellings in the Niger Delta region, there is still insufficient information about the preventive and remedial measures towards house termites by house-owners (HOs) in the region. Through a survey of Omuoko [n = (50%) = 82] and Omuihechi [n = (50%) = 57] communities in the Ikwerre area of Port Harcourt, this study analyzed a 139-house owner samples using standard methods. Data obtained show that 64.7% of HOs use preventive measures which include chemicals (43.2%), chemicals and non-wood materials (20.9%), and non-wood materials (0.6%). A sub-total of 73 HOs representing 52.5% of the total respondents use remedial measures with chemicals (34.2%) being dominant, followed by Chemicals and replacement (27.4%), Replacement (17.8%), Scraping (12.3%), Chemical and scrapping (6.8%), and cement (1.4%). This study indicates that old, wooden, and thatched houses are highly susceptible to termites’ infestations, thus deserving periodic preventive and remedial treatments through expert consultations and/or do-it-yourself methods

Modeling the Grade Point Average (GPA) System in Nigerian Universities

We proposed a mathematical model that captures students’ academic progress via the GPA evaluation system. Our purpose is to understand the effect of failing a course (carryovers), low grade point and probation on the overall academic progress (CGPA) of students. The model is analyzed for the existence and stability of the student progress free equilibrium (SPFE) state. Stability analysis revealed that the model is locally asymptotically stable under certain conditions on the model parameters. A quantitative analysis using numerical experiments with the Maple software was also carried out. From the result of this work, there is a direct relationship between high grade point and high GPA and low grade point and low GPA. Students with high CGPA on a consistent manner tend to graduate in the fourth year while students with low grade and failing courses graduate in the fifth or sixth year. The GPA system goes hand in hand with the semester and course credit system, hence the need for students to understand the functionalities of the impact of the credit system on his overall academic progress. Keywords: Mathematical Model, Course credit system, Semester system, Grade Point Average (GPA) system, Student Academic Progres

Effect of Thermal Treatment on Chemical, Biological and Mechanical Properties of African Whitewood (Triplochiton scleroxylon K. SCHUM)

The thermal modification of wood is a potential alternative method for improving wood properties. This paper evaluates the effect of thermal treatment on the chemical, biological and mechanical properties of African Whitewood (Triplochiton scleroxylon K. Schum) by subjecting the wood to three temperature (200, 170, 140 ℃) at three different time (3, 6, 12 h). Fourier Transformed infrared (FT-IR) spectrometer was used to ascertain the effect of heat treatment on the chemical constituent of the wood while mechanical properties were determined by Modulus of Elasticity (MOE) and Modulus of Rupture (MOR). Durability of heat-treated wood against subterranean termites using field test was also investigated.  FTIR results provided information on the chemical constituents after heat treatment revealing the cellulose and hemicelluloses of Triplochiton scleroxylon wood samples. The decreasing intensity of hydroxyl groups stretching at 3341 cm-1 indicated that heat-treated samples have lost some of their hydroxyl groups. The results showed that the MOR of heated-treated wood at 200 ℃ was significantly higher than the untreated samples. There was also a 26% increase in the MOE of the 170 ℃ heat-treated wood relative to untreated samples. Wood samples thermally treated at 170 ℃ and 200 ℃ as well as untreated wood samples were strongly degraded in term of weight loss (WL) by termite though the degree of degradation varied based on temperature and time in which the wood was modified. However, heat-treated wood at 140 ℃ gave the lowest WL of 20.41% compared to other treated and untreated wood samples. Therefore, strength properties and termites’ resistance of African whitewood also known as Obeche wood in Nigeria could be improved when thermally modified at 170 ℃ and 140 ℃ respectively

Impact of Irrigation on Midsummer Surface Fluxes and Temperature under Dry Synoptic Conditions: A Regional Atmospheric Model Study of the U.S. High Plains

The impact of irrigation on the surface energy budget in the U.S. high plains is investigated. Four 15-day simulations were conducted: one using a 1997 satellite-derived estimate of farmland acreage under irrigation in Nebraska (control run), two using the Olson Global Ecosystem (OGE) vegetation dataset (OGE wet run and OGE dry run), and the fourth with the Kuchler vegetation dataset (natural vegetation run) as lower boundary conditions in the Colorado State University Regional Atmospheric Modeling System (RAMS). In the control and OGE wet simulations, the topsoil in the irrigated locations, up to a depth of 0.2 m, was saturated at 0000 UTC each day for the duration of the experiment (1–15 July 1997). In the other two runs, the soil was allowed to dry out, except when replenished naturally by rainfall. Identical observed atmospheric conditions were used along the lateral boundary in all four cases. The area-averaged model-derived quantities for the grid centered over Nebraska indicate significant differences in the surface energy fluxes between the control (irrigated) and the ‘‘dry’’ simulations. For example, a 36% increase in the surface latent heat flux and a 2.68C elevation in dewpoint temperature between the control run and the OGE dry run is shown. Surface sensible heat flux of the control run was 15% less and the near-ground temperature was 1.28C less compared to the OGE dry run. The differences between the control run and the natural vegetation run were similar but amplified compared to the control run–OGE dry run comparisons. Results of statistical analyses of long-term(1921–2000) surface temperature data from two sites representing locations of extensive irrigated and nonirrigated land uses appear to support model results presented herein of an irrigationrelated cooling in surface temperature. Growing season monthly mean and monthly mean maximum temperature data for the irrigated site indicate a steady decreasing trend in contrast to an increasing trend at the nonirrigated site

Impact of Irrigation on Midsummer Surface Fluxes and Temperature under Dry Synoptic Conditions: A Regional Atmospheric Model Study of the U.S. High Plains

The impact of irrigation on the surface energy budget in the U.S. high plains is investigated. Four 15-day simulations were conducted: one using a 1997 satellite-derived estimate of farmland acreage under irrigation in Nebraska (control run), two using the Olson Global Ecosystem (OGE) vegetation dataset (OGE wet run and OGE dry run), and the fourth with the Kuchler vegetation dataset (natural vegetation run) as lower boundary conditions in the Colorado State University Regional Atmospheric Modeling System (RAMS). In the control and OGE wet simulations, the topsoil in the irrigated locations, up to a depth of 0.2 m, was saturated at 0000 UTC each day for the duration of the experiment (1–15 July 1997). In the other two runs, the soil was allowed to dry out, except when replenished naturally by rainfall. Identical observed atmospheric conditions were used along the lateral boundary in all four cases. The area-averaged model-derived quantities for the grid centered over Nebraska indicate significant differences in the surface energy fluxes between the control (irrigated) and the ‘‘dry’’ simulations. For example, a 36% increase in the surface latent heat flux and a 2.68C elevation in dewpoint temperature between the control run and the OGE dry run is shown. Surface sensible heat flux of the control run was 15% less and the near-ground temperature was 1.28C less compared to the OGE dry run. The differences between the control run and the natural vegetation run were similar but amplified compared to the control run–OGE dry run comparisons. Results of statistical analyses of long-term(1921–2000) surface temperature data from two sites representing locations of extensive irrigated and nonirrigated land uses appear to support model results presented herein of an irrigationrelated cooling in surface temperature. Growing season monthly mean and monthly mean maximum temperature data for the irrigated site indicate a steady decreasing trend in contrast to an increasing trend at the nonirrigated site

Evaluation of Antioxidant Activity of Tetracarpidium conophorum (Müll. Arg) Hutch & Dalziel Leaves

This study evaluated the antioxidant activity as well as bioflavonoid content of the methanol and ethanol-water extracts of the fresh and dried leaves of Tetracarpidium conophorum. Antioxidant activity was determined by spectrophotometric methods using DPPH free radical, nitric oxide radical inhibition and ferric reducing antioxidant power assays. In addition, total phenolics, flavonoids and proanthocyanidin content were also determined. The ethanol: water extract of the dried leaves had the highest antioxidant activity with a 50% inhibition of DPPH at a concentration of 0.017 mg/mL compared to the standards, Vitamin C and Vitamin E with inhibition of 0.019 and 0.011 mg/mL, respectively. This extract also showed nitric oxide radical inhibition activity comparable to that of rutin, 54.45% and 55.03% for extract and rutin, respectively, at 0.1 mg/mL. Ferric reducing power was also comparable to that of ascorbic acid (281 and 287 μM Fe (11)/g, resp.) at a concentration of 1 mg/mL. The methanol extract of both the dried and the fresh leaves had higher phenolic, flavonoids and proanthocyanidin content than the ethanol : water extract. The study reveals that T. conophorum can be an interesting source of antioxidants with their potential use in different fields namely food, cosmetics and pharmaceuticals