Biophysical Properties of Selected Areas of Delta State and Their Suitability Assessment for Coconut, Raphia and Oil Palms Cultivation

This study was conducted to provide information on the biophysical properties and Soil Suitability Assessment (SSA) of seven (Abbi, Agbor, Asaba, Bomadi, Ughelli, Sapele and Warri) locations in Delta state, Nigeria. Composite top and subsurface soil samples were obtained from 0-45 cm and 45-90 cm depths, air dried, sieved through a 2 mm sieve and analyzed for physical and chemical properties using standard laboratory methods. Mean values of the physical and chemical properties of the seven locations were compared and marched with the guidelines provided by FAO framework for rainfed agricultural crops and manual for land suitability evaluation of agricultural crops. The suitability class (aggregate suitability) was determined by most limiting characteristics of that parameter. Results indicated that three (3) out of the seven locations of Delta state are not suitable (N) for the cultivation of Oil palm with limitation being the sandy texture of sub soils. The locations are all however suitable for the cultivation of Coconut and Raphia palms. On aggregate basis, the locations are classified as N (not suitable) for the cultivation of the palms with limitation being the fertility status of the soils but can be corrected. Fertility measures to improve the soils of these locations in Delta state for the cultivation of these economic palms have been suggested. Keywords: Biophysical properties, Coconut Palm, Oil Palm, Raphia palm, Soil Suitability Assessment (SSA).

Tumor-induced senescent T cells with suppressor function: A potential form of tumor immune evasion

Senescent and suppressor T cells are reported to be increased in select patients with cancer and are poor prognostic indicators. Based on the association of these T cells and poor outcomes, we hypothesized that tumors induce senescence in T cells, which negatively effects antitumor immunity. In this report, we show that human T cells from healthy donors incubated with tumor for only 6 h at a low tumor to T-cell ratio undergo a senescence-like phenotype, characterized by the loss of CD27 and CD28 expression and telomere shortening. Tumor-induced senescence of T cells is induced by soluble factors and triggers increases in expression of senescence-associated molecules such as p53, p21, and p16. Importantly, these T cells are not only phenotypically altered, but also functionally altered as they can suppress the proliferation of responder T cells. This suppression requires cell-to-cell contact and is mediated by senescent CD4+ and CD8+ subpopulations, which are distinct from classically described natural T regulatory cells. Our observations support the novel concept that tumor can induce senescent T cells with suppressor function and may effect both the diagnosis and treatment of cancer. ©2008 American Association for Cancer Research.Fil: Montes, Carolina Lucia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Chapoval, Andrei I.. University of Maryland; Estados UnidosFil: Nelson, Jonas. University of Maryland; Estados UnidosFil: Orhue, Vbenosa. University of Maryland; Estados UnidosFil: Zhang, Xiaoyu. University of Maryland; Estados UnidosFil: Schulze, Dan H.. University of Maryland; Estados UnidosFil: Strome, Scott E.. University of Maryland; Estados UnidosFil: Gastman, Brian R.. University of Maryland; Estados Unido

influence of some Soil Properties on the Uptake of Lead and Chromium by Telfaria accidentasis

ABSTRAC

Potassium Status of Soils under Three Different Parent Materials of the Oil palm (Elaeis guineensis Jacq)

Potassium quantity/intensity relations were studied in soils of three different parent materials of the oil palm to determine their potassium status and management. This was done by equilibrating 2.5g of the soil samples in 25 ml of 0.01M CaCl2 at room temperature containing known concentrations of K. Potassium saturation was computed over ECEC. The quantity factor (Q) was determined as the difference in concentration between added K and soil solution K after equilibrating. The Q factor was plotted against the intensity factor. Results showed that the soils were generally acidic while organic matter and total nitrogen decreased with increasing soil depths in all the locations. Potassium activity ratio, its activity, its activity coefficient, ionic strength, free energy of replacement and potassium saturation differed due to the influence of the three different parent materials. In soils under alluvium, ECEC was significantly correlated with potassium activity (r = 0.941*), potassium activity coefficient (r = 0.925*), PBCK (r = 0.953*). In soils under basement complex rocks, ECEC had a significant correlation with potassium activity (r = 0.975**) and calcium activity (r = 0.996**). In soils under shale mixed with sandstone and clay, potassium saturation had a significant correlation with calcium activity coefficient while exchangeable acidity had a significant correlation with potassium activity coefficient. There were high values of potassium activity ratio but low values of ionic strength, free energy of replacement and labile K in all the locations. Conclusion: It follows that adequate maintenance of the ECEC status of soils under alluvium and Basement Complex Rocks through deliberate maintenance of cover cropping and frequent K fertilization could suffice in maintaining the soils K and Ca potential in contrast with soils under Shale Mixed with Sandstone and Clay that requires the application of K fertilizers blended with a little bit of lime. Keywords: Potassium status, potassium activity ratio, ionic strength, potential buffering capacity and labile K. DOI: 10.7176/CMR/14-2-01 Publication date:May 31st 202