Productivity and Resource Use Efficiency in Tomato and Watermelon Farms: Evidence from Ghana

This study examines productivity and resource use efficiency in tomato and watermelon farms in the Dangme East District of Ghana. Cross-sectional data of 200 farmers (100 tomato farmers and 100 watermelon farmers) were obtained from a field survey using structured questionnaires. The empirical results of this study show that, the value of output of watermelon is higher than that of tomato. The difference could be attributed to differences in output prices as well as labour and material input costs incurred in the production of each of these crops. Since prices of inputs are more or less stable over the season, output price difference could be said to be the main cause of this difference. For instance, it costs GH ¢704.59 to produce a hectare of tomato whereas the average cost of producing a hectare of watermelon is GH¢509.03. Conversely, a hectare of tomato yields GH¢480.37 whereas a hectare of watermelon yields GH¢1738.68. Analysis of the factors affecting the value of output of tomato and watermelon shows that, land, labour and experience exert significant influence on the value of output of tomato; whereas land, non-agricultural activity and training significantly influence the level of output of watermelon in the study area. Marginal value products computed for land and labour for each crop were found to be higher than the market prices of  these factors indicating that land and labour are inefficiently used in both tomato and watermelon production though labour did not significantly influence watermelon production. Also, neither did the amount of fertilizer used in tomato production nor the amount of capital used in watermelon production exert significant influence on their value of outputs; these inputs were found to be underutilized in each case. These results have implications for Agricultural policy in Ghana. Key Words: Productivity, Resource Use Efficiency, Tomato, Watermelon, Farms, Ghan

Earliest Archaeological Evidence of Persistent Hominin Carnivory

The emergence of lithic technology by ∼2.6 million years ago (Ma) is often interpreted as a correlate of increasingly recurrent hominin acquisition and consumption of animal remains. Associated faunal evidence, however, is poorly preserved prior to ∼1.8 Ma, limiting our understanding of early archaeological (Oldowan) hominin carnivory. Here, we detail three large well-preserved zooarchaeological assemblages from Kanjera South, Kenya. The assemblages date to ∼2.0 Ma, pre-dating all previously published archaeofaunas of appreciable size. At Kanjera, there is clear evidence that Oldowan hominins acquired and processed numerous, relatively complete, small ungulate carcasses. Moreover, they had at least occasional access to the fleshed remains of larger, wildebeest-sized animals. The overall record of hominin activities is consistent through the stratified sequence – spanning hundreds to thousands of years – and provides the earliest archaeological evidence of sustained hominin involvement with fleshed animal remains (i.e., persistent carnivory), a foraging adaptation central to many models of hominin evolution

Earliest archaeological evidence of persistent hominin carnivory

The emergence of lithic technology by ~2.6 million years ago (Ma) is often interpreted as a correlate of increasingly recurrent hominin acquisition and consumption of animal remains. Associated faunal evidence, however, is poorly preserved prior to ~1.8 Ma, limiting our understanding of early archaeological (Oldowan) hominin carnivory. Here, we detail three large well-preserved zooarchaeological assemblages from Kanjera South, Kenya. The assemblages date to ~2.0 Ma, pre-dating all previously published archaeofaunas of appreciable size. At Kanjera, there is clear evidence that Oldowan hominins acquired and processed numerous, relatively complete, small ungulate carcasses. Moreover, they had at least occasional access to the fleshed remains of larger, wildebeest-sized animals. The overall record of hominin activities is consistent through the stratified sequence ??? spanning hundreds to thousands of years ??? and provides the earliest archaeological evidence of sustained hominin involvement with fleshed animal remains (i.e., persistent carnivory), a foraging adaptation central to many models of hominin evolution.This research was supported by funding from the National Science Foundation, Leakey Foundation, Wenner-Gren Foundation, National Geographic Society, The Leverhulme Trust, University of California, Baylor University, and the City University of New York. Additional logistical support was provided by the Smithsonian Institution???s Human Origins Program and the Peter Buck Fund for Human Origins Research, the British Institute in Eastern Africa, and the National Museums of Kenya. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

A structural investigation of novel thiophene-functionalized BEDT-TTF donors for application as organic field-effect transistors

Three new unsymmetrical thiophene-functionalized bisIJethylenedithio)tetrathiafulvalene (BEDT-TTF) donors (1–3) have been synthesized, characterised and examined as semiconducting materials for organic field-effect transistor (OFET) devices. The X-ray crystal structures of (1) and (2) reveal both neutral donors pack as dimers with lateral S⋯S contacts. For (1) the molecules are co-facially stacked in a head-to-tail manner with some degree of latitudinal slippage. A device prepared from a crystalline thin film of (1) deposited on unmodified silicon wafer substrate displays a mobility of 5.9 × 10−3 cm2 V−1 s−1 with an on/off ratio of 11. The shorter CH2 linker in (2) results in poorer orbital overlap, likely due to significant longitudinal and latitudinal slippage between molecules in the crystal lattice. As a consequence, no field-effect response was observed for the device fabricated from (2)

Solution and Solid-State Characterization of Zn(II) Complexes Containing A New Tridentate N\u3csub\u3e2\u3c/sub\u3es Ligand

A new N2S ligand bis(pyridyl)(2-mercapto-1-methylimidazolyl)methane (2, Py2MeImS) has been synthesized and characterized. Treatment of this ligand with bromide and triflate salts of Zn(II) results in the complexes (Py2MeImS)ZnBr2 (3) and [(Py2MeImS)2Zn](OTf)2 (4), respectively. The solid-state structure of (Py2MeImS)ZnBr2 shows bidentate N,N-coordination of Py2MeImS to the zinc ion, with the sulfur atom of the 2-mercaptoimidazole moiety uncoordinated. Two conformers of 3 rapidly interconvert in solution at room temperature, and variable temperature NMR studies and DFT calculations were used to help assign the likely identity of these conformers. In contrast, the crystal structure of [(Py2MeImS)2Zn] (OTf)2 exhibits a zinc ion with a distorted octahedral geometry where the two sulfur atoms of the two ligands are coordinated to the zinc center in a cis-configuration. Even though the cis-isomer (4-cis) is calculated to be lower in energy than the trans-isomer (4-trans), the low temperature 1H NMR spectrum of 4 reveals a single symmetric species that is inconsistent with the cis-isomer observed in the solid-state structure. DFT calculations propose alternative higher energy structures, including a trans-configuration of the coordinated S-atoms of the two Py2MeImS ligands, as well as structures in which the 2-mercaptoimidazole groups are no longer coordinated to the zinc(II) center. These studies provide valuable insight into the potential binding modes of this new ligand and its behavior in solution

Mps1 directs the assembly of Cdc20 inhibitory complexes during interphase and mitosis to control M phase timing and spindle checkpoint signaling

Cdc20 and Mad2 or Bub1 don’t come together in Mps1-null cells, resulting in a dramatic acceleration of anaphase onset (see also related papers by Hewitt et al. and Santaguida et al. in this issue)

An ab initio and AIM investigation into the hydration of 2-thioxanthine

<p>Abstract</p> <p>Background</p> <p>Hydration is a universal phenomenon in nature. The interactions between biomolecules and water of hydration play a pivotal role in molecular biology. 2-Thioxanthine (2TX), a thio-modified nucleic acid base, is of significant interest as a DNA inhibitor yet its interactions with hydration water have not been investigated either computationally or experimentally. Here in, we reported an <it>ab initio </it>study of the hydration of 2TX, revealing water can form seven hydrated complexes.</p> <p>Results</p> <p>Hydrogen-bond (H-bond) interactions in 1:1 complexes of 2TX with water are studied at the MP2/6-311G(d, p) and B3LYP/6-311G(d, p) levels. Seven 2TX^...H₂O hydrogen bonded complexes have been theoretically identified and reported for the first time. The proton affinities (PAs) of the O, S, and N atoms and deprotonantion enthalpies (DPEs) of different N-H bonds in 2TX are calculated, factors surrounding why the seven complexes have different hydrogen bond energies are discussed. The theoretical infrared and NMR spectra of hydrated 2TX complexes are reported to probe the characteristics of the proposed H-bonds. An improper blue-shifting H-bond with a shortened C-H bond was found in one case. NBO and AIM analysis were carried out to explain the formation of improper blue-shifting H-bonds, and the H-bonding characteristics are discussed.</p> <p>Conclusion</p> <p>2TX can interact with water by five different H-bonding regimes, N-H^...O, O-H^...N, O-H^...O, O-H^...S and C-H^...O, all of which are medium strength hydrogen bonds. The most stable H-bond complex has a closed structure with two hydrogen bonds (N(7)-H^...O and O-H^...O), whereas the least stable one has an open structure with one H-bond. The interaction energies of the studied complexes are correlated to the PA and DPE involved in H-bond formation. After formation of H-bonds, the calculated IR and NMR spectra of the 2TX-water complexes change greatly, which serves to identify the hydration of 2TX.</p