Heavy metals accumulation in leaves and tubers of cassava (Manihot esculenta Crantz) grown in crude oil contaminated soil at Ikot Ada Udo, Nigeria

Pot experiment was set up to assess the levels of heavy metals accumulation in leaves and tubers of cassava (Manihot esculenta Crantz) grown in crude oil contaminated soil in the Niger Delta Region of Nigeria. Three cassava cultivars were used for the study viz: NR-8082, TMS-30572 and a Local variety (LV). The crops were planted in pots and nurtured to maturity. They were then assessed for the concentrations of the following heavy metals: Pb, Cd, Cr, Ni, Zn and Fe in both the leaves and tubers using standard laboratory procedures. Data analysis was carried out using the Analysis of Variance (ANOVA) and significantly different means were separated using the Duncan Multiple Range Test (DMRT). The analysis revealed that TMS accumulated the highest quantities of these metals, followed by NR and lastly, the local variety (V), this being a function of biomass production. Transfer Factors also proved the order of accumulation of this heavy metal as: TMS > NR > LV. Generally, the order of prevalence of heavy metal in both the leaves and the tubers was: Fe > Zn > Ni > Pb > Cd > Cr. This study revealed that crude oil pollution is increasingly raising the levels of heavy metals in the soils of Niger Delta and these metals are being taken up by plants including cassava, which is the most important staple food crop of the area. Consequently, crops farmers are advised against cultivating at crude oil contaminated sites for the risk of accumulation of heavy metals in plant tissues.Keywords: Cassava, Heavy Metal, Crude Oil, Contamination Soil, Accumulatio

Effects of organic supplement on growth, leaf chlorophyll and nitrogen index of cassava (Manihot esculenta Crantz) cultivated in crude-oil- contaminated soil in Nigeria

A field study was conducted in the 2015-2016 cropping season to investigate the effect of soil amendment on the growth, leaf chlorophyll and nitrogen index of cassava (Manihot esculenta Crantz) cultivated in crude oil contaminated soil located at Ikot Ada Udo, Ikot Abasi Local Government Area LGA) of Akwa Ibom State, Nigeria. The soil samples were amended with organic supplement (palm bunch ash, PBA and dried poultry litter, DPL) singly and in combination using three different cassava cultivars (TMS 30572, NR 8082 and Local variety) where the growth parameters, chlorophyll content and nitrogen index were monitored at eight (8) weeks intervals for twenty-four (24) weeks. The mean results obtained showed that plant height, leaf area and stem girth increased with increase in the number of weeks with PBA+DPL and DPL amended soil showing significant increase in plants height as compared to the PBA amended soil and the control soil. The same trend was observed with other growth parameters. For the plant varieties, growth in TMS 30572 was significantly higher than others except for the 8th week where the local variety was highest with NR 8082 being the least in all growth parameters. After 16 weeks of sprouting, plots treated with PBA had higher number of Nodes and Leaf Nitrogen Index while plots treated with DPL had higher Chlorophyll A and B contents. This study recommended that varieties TMS 30572 and the Local (Nsak Idaha) should be planted on a crude-oil-polluted site and the soil should be amended with organic nutrients to improve the crop growth performance.Keywords: Soil Amendment, Leaf Chlorophyll, Nitrogen Index, Manihot Esculenta Crantz and Contaminated Soi

Predation risk: a potential mechanism for effects of a wind energy facility on Greater Prairie-Chicken survival

Recent expansion of the wind energy industry has raised concerns about the potential effects of wind energy facilities on prairie grouse. For example, efforts have been made to evaluate indirect effects on prairie grouse survival, but it is also critical to investigate the underlying mechanisms to direct conservation strategies. The objective of this study was to investigate the indirect effects of a wind energy facility on the survival of female Greater Prairie-Chickens (Tympanuchus cupido pinnatus) and on the occupancy of avian and mammalian predators. Between March and July of 2013 and 2014, we investigated spatial variation in predation risk by sampling occupancy of mammalian and avian predators within 10 km of a wind energy facility constructed in 2005 in Brown County, Nebraska, USA. During the same period, we assessed spatial variation in daily survival of radio-marked females within the same area.We found little evidence that probability of site occupancy (Ψ) of avian predators was lower near the wind energy facility (within 2 km: Ψ = 0.70, 95% CI = 0.22–0.95; beyond 2 km: Ψ = 0.93, 95% CI = 0.02–1.00), suggesting that avian predators did not display local-scale avoidance behavior around wind turbines. Mammalian predators were documented at all of our sample locations, but the capture index for all mammals was lower at sample sites near the wind turbines (P = 0.004). Occupancy of coyotes (Canis latrans), the likely main mammalian predator of adult prairie-chickens in the area, did not vary significantly throughout our study site (within 0.5 km of wind energy facility: Ψ = 0.65, 95% CI = 0.07–0.98; beyond 0.5 km: Ψ = 0.96, 95% CI = 0.04–1.00), although trends were in the direction expected if coyotes were avoiding the wind energy facility. Distance to wind turbine had no effect on daily survival (SD) of female prairie-chickens (SD = 0.9948, SE = 0.0015). The potential for predators to avoid wind energy facilities, and thus affect predation risk, underscores the complexity of planning to address potential impacts of wind energy as variation in predation risk may have consequences for the population viability of a wide range of species at risk from wind energy development

Magnetic field diagnostics and spatio-temporal variability of the solar transition region

Magnetic field diagnostics of the transition region from the chromosphere to the corona faces us with the problem that one has to apply extreme UV spectro-polarimetry. While for coronal diagnostic techniques already exist through infrared coronagraphy above the limb and radio observations on the disk, for the transition region one has to investigate extreme UV observations. However, so far the success of such observations has been limited, but there are various projects to get spectro-polarimetric data in the extreme UV in the near future. Therefore it is timely to study the polarimetric signals we can expect for such observations through realistic forward modeling. We employ a 3D MHD forward model of the solar corona and synthesize the Stokes I and Stokes V profiles of C IV 1548 A. A signal well above 0.001 in Stokes V can be expected, even when integrating for several minutes in order to reach the required signal-to-noise ratio, despite the fact that the intensity in the model is rapidly changing (just as in observations). Often this variability of the intensity is used as an argument against transition region magnetic diagnostics which requires exposure times of minutes. However, the magnetic field is evolving much slower than the intensity, and thus when integrating in time the degree of (circular) polarization remains rather constant. Our study shows the feasibility to measure the transition region magnetic field, if a polarimetric accuracy on the order of 0.001 can be reached, which we can expect from planned instrumentation.Comment: Accepted for publication in Solar Physics (4.Mar.2013), 19 pages, 9 figure

Particle physics models of inflation

Inflation models are compared with observation on the assumption that the curvature perturbation is generated from the vacuum fluctuation of the inflaton field. The focus is on single-field models with canonical kinetic terms, classified as small- medium- and large-field according to the variation of the inflaton field while cosmological scales leave the horizon. Small-field models are constructed according to the usual paradigm for beyond Standard Model physicsComment: Based on a talk given at the 22nd IAP Colloquium, ``Inflation +25'', Paris, June 2006 Curve omitted from final Figur

Magnetic Field Amplification in Galaxy Clusters and its Simulation

We review the present theoretical and numerical understanding of magnetic field amplification in cosmic large-scale structure, on length scales of galaxy clusters and beyond. Structure formation drives compression and turbulence, which amplify tiny magnetic seed fields to the microGauss values that are observed in the intracluster medium. This process is intimately connected to the properties of turbulence and the microphysics of the intra-cluster medium. Additional roles are played by merger induced shocks that sweep through the intra-cluster medium and motions induced by sloshing cool cores. The accurate simulation of magnetic field amplification in clusters still poses a serious challenge for simulations of cosmological structure formation. We review the current literature on cosmological simulations that include magnetic fields and outline theoretical as well as numerical challenges.Comment: 60 pages, 19 Figure

Inhibitors of retrograde trafficking active against ricin and Shiga toxins also protect cells from several viruses, Chlamydiales and Leishmania

Medical countermeasures to treat biothreat agent infections require broad-spectrum therapeutics that do not induce agent resistance. A cell-based high-throughput screen (HTS) against ricin toxin combined with hit optimization allowed selection of a family of compounds that meet these requirements. The hit compound Retro-2 and its derivatives have been demonstrated to be safe in vivo in mice even at high doses. Moreover, Retro-2 is an inhibitor of retrograde transport that affects syntaxin-5- dependent toxins and pathogens. As a consequence, it has a broad-spectrum activity that has been demonstrated both in vitro and in vivo against ricin, Shiga toxin-producing O104:H4 enterohemorrhagic E. coli and Leishmania sp. and in vitro against Ebola, Marburg and poxviruses and Chlamydiales. An effect is anticipated on other toxins or pathogens that use retrograde trafficking and syntaxin-5. Since Retro-2 targets cell components of the host and not directly the pathogen, no selection of resistant pathogens is expected. These lead compounds need now to be developed as drugs for human use