Climate change impacts on food security in Sub-Saharan Africa: Insights from comprehensive climate change scenarios

Climate change impacts vary significantly, depending on the scenario and the Global Circulation Model (GCM) chosen. This is particularly true for Sub-Saharan Africa. This paper uses a comprehensive climate change scenario (CCC) based on ensembles of 17 GCMs selected based on their relative performance regarding past predictions of temperature and precipitation at the level of 2o x 2o grid cells, generated by a recently developed entropy-based downscaling model. Based on past performance, the effects of temperature and precipitation across the 17 GCMs are incorporated into a global hydrological model that is linked with IFPRI's IMPACT water and food projections model to assess the effects of climate change on food outcomes for the region. For Sub-Saharan Africa, the paper finds that the CCC scenario predicts consistently higher temperatures and mixed precipitation changes for the 2050 period. Compared to historic climate scenarios, climate change will lead to changes in yield and area growth, higher food prices and therefore lower affordability of food, reduced calorie availability, and growing childhood malnutrition in Sub-Saharan Africa.Climate change, hydrology, crop yield, food security,

Characteristics of the O(1S) to O(1D) 557.7 nm green emission observed in an argon plasma jet

An extensive study on the green auroral emission characterization is presented based on a single dielectric barrier discharge geometry argon plasma jet driven by a kHz sine voltage. The plasma was generated by using 99.999% pure argon and the observed 557.7 nm green line resulted from the excited O(1S) state. An optical emission spectroscopy method using line ratios of argon was used to obtain the electron density and electron temperature under different conditions in the downstream region. The characteristics of discharge and green emission with variations in interelectrode distance, applied voltage (power) and flow rate are discussed. The spatially diffuse distribution of O(1S), owing to its long lifetime, is shown by the short exposure imaging. Two discharge regimes are presented, accompanied by two distinct branches of the green emission intensity, with a clear conclusion that the 557.7 nm emission is favored in the low electron temperature environment. In this work, the intense and diffuse green plume only forms when the downstream electron density is approximately lower than 1 × 1014 cm−3 and the electron temperature is lower than 1.1 eV. By charging the two electrodes in two opposite ways, it is shown that the green emission from oxygen is favored in the case where the electric field and the electron drift are not continuous

Characteristics of the O(1S) to O(1D) 557.7 nm green emission observed in an argon plasma jet

An extensive study on the green auroral emission characterization is presented based on a single dielectric barrier discharge geometry argon plasma jet driven by a kHz sine voltage. The plasma was generated by using 99.999% pure argon and the observed 557.7 nm green line resulted from the excited O(1S) state. An optical emission spectroscopy method using line ratios of argon was used to obtain the electron density and electron temperature under different conditions in the downstream region. The characteristics of discharge and green emission with variations in interelectrode distance, applied voltage (power) and flow rate are discussed. The spatially diffuse distribution of O(1S), owing to its long lifetime, is shown by the short exposure imaging. Two discharge regimes are presented, accompanied by two distinct branches of the green emission intensity, with a clear conclusion that the 557.7 nm emission is favored in the low electron temperature environment. In this work, the intense and diffuse green plume only forms when the downstream electron density is approximately lower than 1 × 1014 cm−3 and the electron temperature is lower than 1.1 eV. By charging the two electrodes in two opposite ways, it is shown that the green emission from oxygen is favored in the case where the electric field and the electron drift are not continuous

Biomechanical Analysis of the Fixation System for T-Shaped Acetabular Fracture

This study aims to evaluate the biomechanical mechanism of fixation systems in the most frequent T-shaped acetabular fracture using finite element method. The treatment of acetabular fractures was based on extensive clinical experience. Three commonly accepted rigid fixation methods (double column reconstruction plates (P × 2), anterior column plate combined with posterior column screws (P + PS), and anterior column plate combined with quadrilateral area screws (P + QS)) were chosen for evaluation. On the basis of the finite element model, the biomechanics of these fixation systems were assessed through effective stiffness levels, stress distributions, force transfers, and displacements along the fracture lines. All three fixation systems can be used to obtain effective functional outcomes. The third fixation system (P + QS) was the optimal method for T-shaped acetabular fracture. This fixation system may reduce many of the risks and limitations associated with other fixation systems

Experimental Implementation of Remote State Preparation by Nuclear Magnetic Resonance

We have experimentally implemented remote state preparation (RSP) of a qubit from a hydrogen to a carbon nucleus in molecules of carbon-13 labeled chloroform $^{13}$CHCl$_{3}$ over interatomic distances using liquid-state nuclear magnetic resonance (NMR) technique. Full RSP of a special ensemble of qubits, i.e., a qubit chosen from equatorial and polar great circles on a Bloch sphere with Pati's scheme, was achieved with one cbit communication. Such a RSP scheme can be generalized to prepare a large number of qubit states and may be used in other quantum information processing and quantum computing.Comment: 10 pages,5 PS figure

Experimental realization of a highly structured search algorithm

The highly structured search algorithm proposed by Hogg[Phys.Rev.Lett. 80,2473(1998)] is implemented experimentally for the 1-SAT problem in a single search step by using nuclear magnetic resonance technique with two-qubit sample. It is the first demonstration of the Hogg's algorithm, and can be readily extended to solving 1-SAT problem for more qubits in one step if the appropriate samples possessing more qubits are experimentally feasible.Comment: RevTex, 11 pages + 3 pages of figure

Preparation of pseudo-pure states by line-selective pulses in Nuclear Magnetic Resonance

A new method of preparing the pseudo-pure state of a spin system for quantum computation in liquid nuclear magnetic resonance (NMR) was put forward and demonstrated experimentally. Applying appropriately connected line-selective pulses simultaneously and a field gradient pulse techniques we acquired straightforwardly all pseudo-pure states for two qubits in a single experiment much efficiently. The signal intensity with the pseudo-pure state prepared in this way is the same as that of temporal averaging. Our method is suitable for the system with arbitrary numbers of qubits. As an example of application, a highly structured search algorithm----Hogg's algorithm was also performed on the pseudo-pure state $\mid 00>$ prepared by our method.Comment: RevTEX,10 pages,5 PS figure

A Cryptic Polyene Biosynthetic Gene Cluster in Streptomyces calvus Is Expressed upon Complementation with a Functional bldA Gene

SummaryStreptomyces calvus is best known as the producer of the fluorinated natural product nucleocidin. This strain of Streptomycetes is also unusual for displaying a “bald” phenotype that is deficient in the formation of aerial mycelium and spores. Genome sequencing of this organism revealed a point mutation in the bldA gene that is predicted to encode a misfolded Leu-tRNAUUA molecule. Complementation of S. calvus with a correct copy of bldA restored sporulation and additionally promoted production of a polyeneoic acid amide, 4-Z-annimycin, and a minor amount of the isomer, 4-E-annimycin. Bioassays reveal that these compounds inhibit morphological differentiation in other Actinobacteria. The annimycin gene cluster encoding a type 1 polyketide synthase was identified and verified through disruption studies. This study underscores the importance of the bldA gene in regulating the expression of cryptic biosynthetic genes

A STUDY ON ANTICANCER ACTIVITY OF CAULIS SPATHOLOBI EXTRACT ON HUMAN OSTEOSARCOMA SAOS-2 CELLS

The objective of the present study was to investigate the anticancer activity of Chinese medicine Caulis Spatholobi extract on multicentric osteosarcoma cells. Ultraviolet spectrophotometry was used to determine the total flavonoid content in each sample; vanillin sulphuric acid assay was used to determine the condensed tannin content in each sample; and the varying degrees of inhibitory activities of ethanol, ethyl acetate and n-butanol extracts of Caulis Spatholobi on human osteosarcoma Saos-2 cells were studied. The results showed that the inhibitory activity of ethyl acetate extract was the highest among the four extracts. The condensed tannin contents of 1.2 mg/mL Caulis Spatholobi water extract, ethanol extract, ethyl acetate extract and petroleum ether extract were 26.23%, 48.36%, 70.18% and 40.51% respectively; and condensed tannin content of 1.5 mg/mL Caulis Spatholobi water extract, ethanol extract, ethyl acetate extract and petroleum ether extract were 4.15%, 5.81%, 8.76% and 7.30% respectively