3,883 research outputs found
Resource Use Efficiency in Part-time Food Crop Production: The Stochastic Frontier Approach
In this paper, stochastic frontier production model was used to analyze the resource use efficiency of part-time food crop farmers in Idah, North Central Nigeria. The result shows that farm size, labour and planting materials are significant determinants of farm output in part-time food crop farming.
Analysis of inefficiency factors reveal the significant inefficiency variables to include; level of education, household size and farming experience. The result also shows that over 72% of part-time farmers were above average in resource use efficiency; maximum efficiency is 0.98, while minimum efficiency is 0.36 with mean efficiency of 0.65. The study also revealed that rising age and household size contribute to resource use inefficiency in part-time food crop farming, while level of education and years of farming experience increased resource use efficiency among the sample farmers. Implications are that policies that would encourage relatively younger and educated persons and provide them easy access to improved
seeds and fertilizers will go a long way in enhancing resource use efficiency in part-time food crop farming
Three-loop HTL gluon thermodynamics at intermediate coupling
We calculate the thermodynamic functions of pure-glue QCD to three-loop order
using the hard-thermal-loop perturbation theory (HTLpt) reorganization of
finite temperature quantum field theory. We show that at three-loop order
hard-thermal-loop perturbation theory is compatible with lattice results for
the pressure, energy density, and entropy down to temperatures .
Our results suggest that HTLpt provides a systematic framework that can used to
calculate static and dynamic quantities for temperatures relevant at LHC.Comment: 24 pages, 13 figs. 2nd version: improved discussion and fixing typos.
Published in JHE
Forensic odontological observations in the victims of DANA air crash
Introduction: Forensic odontology or forensic dentistry is that aspect of forensic science that uses the application of dental science for the identification of unknown human remains and bite marks. Deaths resulting from mass disasters such as plane crash or fire incidence have always been given mass burial in Nigeria. This was obviously due to the fact that Forensic Pathologists whose roles involve disaster victim identification were not available at that time. However, in the DANA air crash in Lagos in 2012, the Forensic pathologist and dental teams were invited for the first time to identify the victims. The objectives of this paper are to identify the extent of victimsâ identification using Forensic odontology alone and its  combination with DNA analysis. It also presents the pattern of fractures seen in the mandible and maxilla of the victims. Methods: the bodies were dissected using following the standard protocol dissection. Prior to this all the victims had Dental Radiological Examination. The oral cavities were exposed after which the Odontology team was invited for photographing first, followed by dental charting. Fractures of the mandible, maxilla including the anatomical regions were all recorded and photographed. Dental prosthesis, restorations, crowns and bridge and other findings were also noted, recorded and compared with ante mortem records where available. Results: a total of152 bodies were recovered from the crash site while 148 victims were eventually identified through a combination of DNA analysis and forensic odontology.This represented 97.4%.Forensic odontology was the primary identifier in 10%. There were no fingerprinting information in this country at present therefore, it could not be used. A total of 89 (60%) were males while females accounted for 59(40%).This gives a ratio of 1.5:1.Most of the victims were in the age group 30-49years; this represented 52% of the victims while the least involved age groups were victims above 60 years of age which accounted for only 4.7%. Mandibular fractures were seen in 29 victims, maxilla in 15, combined  mandibullo/maxillary in 15 victims, while 89 victims had nojaw fracture.The most common area of fracture in the mandible was the body which accounted for 36.4%, closely followed byparasymphysealregion31.9 %,symphyseal22.7% and the angle 9.0%. The most common fracture in the maxillae was palatal split fracture which accounted for 52%, this was followed by pterygoid24%,alveolar 8% and multiple locations 16%. Conclusion: a combination of DNA analysis and forensic odontology was able to identify a total of 148 victims out of 152 representing 97.4%. Forensic odontology was the primary identifier in only 10%. In the latter, poor and lack of dental records were responsible for this very low figure. The most common area of fracture in the mandible was th ebody which accounted for 36.4%, while that of the maxillae was palatal fracture whichaccounted for 52%. Padding of the back of the seats in the aircraft should be canvassed for to provide Cushing effect for passengers
New Glucopyranosylglyceryl-N-Octenyl Adipate and Bioactivity of Retro and Condensed Chalcones from Toussaintia Orientalis
1-(3-ÎČ-D-Glucopyranosylglycer-2-yl)-6-N-(oct-2-enyl)-adipate, [orientalin, 1] was isolated as a new metabolite from the polar leaf extracts of Toussaintia orientalis Verdc (Annonaceae), together with the glycoflavonoids afzelin and quercitrin, and the indolidinoids toussaintines A-C. The reversed chalcones 2-hydroxy-3,4,6-trimethoxychalcone (2) and 2-hydroxy-3,4,6- trimethoxydihydrochalcone (3), the condensed chalcone (+)-6a,12a-dihydro-6-phenyl-7-styryl- 6H,7H-[1]benzopyrano[4,3-][l]benzopyran (4), and mixtures of known triterpenoids and steroids were isolated from the less polar extracts of the root and stem bark of the same plant. The structures were established upon detailed analysis of spectroscopic data and other physical parameters. The chalcones exhibited antimicrobial, anti-inflammatory, antiproliferative and cytotoxic activity at varying efficacy levels, the reversed chalcone 2 demonstrating antiinflammatory potency against COX-2 enzyme that was superior to the standard drug Indomethacin. These results have further indicated the versatility of Annonaceae species in accumulating structurally varied natural products, some of them having unprecedented structures.Keywords: Toussaintia orientalis; Annonaceae; orientalin, 1-(3-b-D-glucopyranosylglycer-2-yl)-6-N-(oct-2-enyl)-adipate; condensed and retrochalcones; anti-inflammatory
Chiral perturbation theory in a magnetic background - finite-temperature effects
We consider chiral perturbation theory for SU(2) at finite temperature in
a constant magnetic background . We compute the thermal mass of the pions
and the pion decay constant to leading order in chiral perturbation theory in
the presence of the magnetic field. The magnetic field gives rise to a
splitting between and as well as between
and . We also calculate the free energy and the
quark condensate to next-to-leading order in chiral perturbation theory. Both
the pion decay constants and the quark condensate are decreasing slower as a
function of temperature as compared to the case with vanishing magnetic field.
The latter result suggests that the critical temperature for the chiral
transition is larger in the presence of a constant magnetic field. The increase
of as a function of is in agreement with most model calculations but
in disagreement with recent lattice calculations.Comment: 24 pages and 9 fig
Mathematical Evaluation of Community Level Impact of Combining Bed Nets and Indoor Residual Spraying upon Malaria Transmission in Areas where the main Vectors are Anopheles Arabiensis Mosquitoes.
Indoor residual insecticide spraying (IRS) and long-lasting insecticide treated nets (LLINs) are commonly used together even though evidence that such combinations confer greater protection against malaria than either method alone is inconsistent. A deterministic model of mosquito life cycle processes was adapted to allow parameterization with results from experimental hut trials of various combinations of untreated nets or LLINs (Olyset, PermaNet 2.0, Icon Life nets) with IRS (pirimiphos methyl, lambda cyhalothrin, DDT), in a setting where vector populations are dominated by Anopheles arabiensis, so that community level impact upon malaria transmission at high coverage could be predicted. Intact untreated nets alone provide equivalent personal protection to all three LLINs. Relative to IRS plus untreated nets, community level protection is slightly higher when Olyset or PermaNet 2.0 nets are added onto IRS with pirimiphos methyl or lambda cyhalothrin but not DDT, and when Icon Life nets supplement any of the IRS insecticides. Adding IRS onto any net modestly enhances communal protection when pirimiphos methyl is sprayed, while spraying lambda cyhalothrin enhances protection for untreated nets but not LLINs. Addition of DDT reduces communal protection when added to LLINs. Where transmission is mediated primarily by An. arabiensis, adding IRS to high LLIN coverage provides only modest incremental benefit (e.g. when an organophosphate like pirimiphos methyl is used), but can be redundant (e.g. when a pyrethroid like lambda cyhalothin is used) or even regressive (e.g. when DDT is used for the IRS). Relative to IRS plus untreated nets, supplementing IRS with LLINs will only modestly improve community protection. Beyond the physical protection that intact nets provide, additional protection against transmission by An. arabiensis conferred by insecticides will be remarkably small, regardless of whether they are delivered as LLINs or IRS. The insecticidal action of LLINs and IRS probably already approaches their absolute limit of potential impact upon this persistent vector so personal protection of nets should be enhanced by improving the physical integrity and durability. Combining LLINs and non-pyrethroid IRS in residual transmission systems may nevertheless be justified as a means to manage insecticide resistance and prevent potential rebound of not only An. arabiensis, but also more potent, vulnerable and historically important species such as Anopheles gambiae and Anopheles funestus
Thermodynamics of SU(N) Yang-Mills theories in 2+1 dimensions II - The deconfined phase
We present a non-perturbative study of the equation of state in the
deconfined phase of Yang-Mills theories in D=2+1 dimensions. We introduce a
holographic model, based on the improved holographic QCD model, from which we
derive a non-trivial relation between the order of the deconfinement phase
transition and the behavior of the trace of the energy-momentum tensor as a
function of the temperature T. We compare the theoretical predictions of this
holographic model with a new set of high-precision numerical results from
lattice simulations of SU(N) theories with N=2, 3, 4, 5 and 6 colors. The
latter reveal that, similarly to the D=3+1 case, the bulk equilibrium
thermodynamic quantities (pressure, trace of the energy-momentum tensor, energy
density and entropy density) exhibit nearly perfect proportionality to the
number of gluons, and can be successfully compared with the holographic
predictions in a broad range of temperatures. Finally, we also show that, again
similarly to the D=3+1 case, the trace of the energy-momentum tensor appears to
be proportional to T^2 in a wide temperature range, starting from approximately
1.2 T_c, where T_c denotes the critical deconfinement temperature.Comment: 2+36 pages, 10 figures; v2: comments added, curves showing the
holographic predictions included in the plots of the pressure and energy and
entropy densities, typos corrected: version published in JHE
Thermodynamics of deformed AdS model with a positive/negative quadratic correction in graviton-dilaton system
By solving the Einstein equations of the graviton coupling with a real scalar
dilaton field, we establish a general framework to self-consistently solve the
geometric background with black-hole for any given phenomenological holographic
models. In this framwork, we solve the black-hole background, the corresponding
dilaon field and the dilaton potential for the deformed AdS model with a
positive/negative quadratic correction. We systematically investigate the
thermodynamical properties of the deformed AdS model with a positive and
negative quadratic correction, respectively, and compare with lattice QCD on
the results of the equation of state, the heavy quark potential, the Polyakov
loop and the spatial Wilson loop. We find that the bulk thermodynamical
properties are not sensitive to the sign of the quadratic correction, and the
results of both deformed holographic QCD models agree well with lattice QCD
result for pure SU(3) gauge theory. However, the results from loop operators
favor a positive quadratic correction, which agree well with lattice QCD
result. Especially, the result from the Polyakov loop excludes the model with a
negative quadratic correction in the warp factor of .Comment: 26 figures,36 pages,V.3: an appendix,more equations and references
added,figures corrected,published versio
Magnetic Coupling in the Quiet Solar Atmosphere
Three kinds of magnetic couplings in the quiet solar atmosphere are
highlighted and discussed, all fundamentally connected to the Lorentz force.
First the coupling of the convecting and overshooting fluid in the surface
layers of the Sun with the magnetic field. Here, the plasma motion provides the
dominant force, which shapes the magnetic field and drives the surface dynamo.
Progress in the understanding of the horizontal magnetic field is summarized
and discussed. Second, the coupling between acoustic waves and the magnetic
field, in particular the phenomenon of wave conversion and wave refraction. It
is described how measurements of wave travel times in the atmosphere can
provide information about the topography of the wave conversion zone, i.e., the
surface of equal Alfv\'en and sound speed. In quiet regions, this surface
separates a highly dynamic magnetic field with fast moving magnetosonic waves
and shocks around and above it from the more slowly evolving field of high-beta
plasma below it. Third, the magnetic field also couples to the radiation field,
which leads to radiative flux channeling and increased anisotropy in the
radiation field. It is shown how faculae can be understood in terms of this
effect. The article starts with an introduction to the magnetic field of the
quiet Sun in the light of new results from the Hinode space observatory and
with a brief survey of measurements of the turbulent magnetic field with the
help of the Hanle effect.Comment: To appear in "Magnetic Coupling between the Interior and the
Atmosphere of the Sun", eds. S.S. Hasan and R.J. Rutten, Astrophysics and
Space Science Proceedings, Springer-Verlag, Heidelberg, Berlin, 200
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