Sustainability Assessment of Banana (Musa spp.) Yield Gap Reduction through Value Chain Development Interventions in Smallholder Farming Systems in Manicaland, Zimbabwe

This study evaluated the effectiveness of donor supported agricultural value chain development projects in sustainably narrowing yield gaps for banana smallholder farmer producers in Manicaland, Zimbabwe. The study used a mixed methods research design that relied on farmers records for the quantitative analysis and focus group discussion and in-depth interviews for key experts for the qualitative aspects. A mix of regression analysis, t-tests, Pearsons’s correlation and analysis of variance statistical methods were used for the quantitative analysis while thematic response analysis was used for the qualitative engagements. The findings showed that by the end of the activity, the project had successfully narrowed the banana yield gaps to 18.66 tons per hectare working with a potential yield base of 40 tons. However, 5 years after the project closure the yield gap had fallen to 24.7 tons indicating a lack of sustainability of yield gap reduction. However, the yield gap slump does not override the fact that farmers on average were still able to sell approximately 5 tons per every 6 months after 5 years from the project closure which is beyond any poverty threshold. This suggests genuine upward economic mobility. Additionally, in analyzing what factors had the greatest influence on yield gap reduction, the access to fertilizer ranked highest where genetics, irrigation and improved agronomy followed in that respective order. The study further showed that farmers who receive value chain development support whilst at an already commercialized state tend to maintain productivity thresholds higher in comparison to those who are at a pre commercial state. This is evidenced by the fact that the pre commercial farmers had a yield reduction of 30.83 percent after 5 years of the project closure whereas the former realized a productivity growth of 7.84%. In conclusion, whilst the intervention was successful in transitioning farmers out of poverty, more investment should be made towards transitioning smallholder farmers to integrated soil fertility management practices and improvement of agronomic efficiency through stronger on field collaboration between research institutions, the government and development institutions.

Estimating soil moisture content using laboratory spectral data

Monitoring soil moisture is important for agriculture and forestry and plays an essential role in land surface processes as well as providing feedback among the earth’s surface ecosystems. Large-scale regional soil moisture spatial data can be obtained with a reliable and operational approach using remote sensing. In this paper, we provide an operational framework for retrieving soil moisture using laboratory spectral data. The inverted Gaussian function was used to fit soil spectral data, and its feature parameters, including absorption depth (AD) and absorption area (AA), were selected as variables for a soil moisture estimate model. There was a significant correlative relationship between soil moisture and AD, as well as AA near 1400 and 1900 nm. A one-variable linear regression model was established to estimate soil moisture. The model was evaluated using the determination coefficients (R2), root mean square error and average precision.Four models were established and evaluated in this study. The determination coefficients of the four models ranged from 0.794 to 0.845. The average accuracy for soil moisture estimates ranged from 90 to 92%. The results prove that it is feasible to estimate soil moisture using remote sensing technology.

Cloning of vacuolar H^+ -ATPase subunit c genes from Japanese iris, and functional characterization in yeast

Five different isoforms （IrlVHA-c1-c5） of V-ATPase subunit c （VHA-c） were cloned from a Japanese iris （Iris lactea Pall. var. chinensis Fisch. Koidz） cDNA library using degenerate primers PCR and the 5＇-RACE technique. The sequence analysis showed the open reading frame （ORF） of the IrlVHA-c1 c5 to be 495 bp, corresponding to a protein of 164 amino acids. Among the five isoforms, IrlVHA-c1 and IrlVHA-c2 are completely homologous. The IrlVHA-c protein is localized at the vacuolar membrane as indicated by a green fluorescent protein （GFP） marker. Its over-expression in yeast could enhance yeast tolerance to NaCl stress. These results show that there are at least five genes encoding different isoforms of IrlVHA-c in Japanese iris and IrlVHA-c is important for the function of V-ATPase.

Characterization of increased cuticular wax mutant and analysis of genes involved in wax biosynthesis in Dianthus spiculifolius

Cuticular wax formation on the surface of plant leaves is associated with drought-stress tolerance.The identification of wax biosynthesis-related genes will contribute to the genetic improvement of drought resistance in plants.In this study,we characterize a novel Dianthus spiculifolius mutant with increased cuticular wax.The mutant exhibited stronger drought resistance as indicated by less leaf wilting and death,higher leaf relative water content and water retention capacity,and slower water loss and chlorophyll extraction than did the wild type during drought treatment.In the mutant leaves,2730 upregulated and 2151 downregulated differentially expressed genes(DEGs)were identified by transcriptome sequencing.A wax biosynthesis pathway of the identified DEGs was significantly enriched.Finally,three key genes(DsCER1,DsMAH1,and DsWSD1)involved in wax biosynthesis were identified and verified by qPCR.These results suggest that differential expression of DEGs involved in wax biosynthesis may be associated with the increase in cuticular wax in the mutant.Taken together,our results help elucidate wax formation patterns in D.spiculifolius.Furthermore,the DEGs involved in wax biosynthesis identified here may be valuable genetic resources for improving plant stress tolerance through increased accumulation of cuticular wax.

Coupled-channel optical calculation for positron-lithium scattering

Positron scattering with atomic lithium is investigated by using a coupled-channel optical method.The ionization continuum and positronium formation channels are taken into account via a complex equivalent-local optical potential.The positronium formation cross sections and the ionization cross sections,as well as the total scattering cross sections,are reported at energies above 3 eV and compared with available experimental and theoretical data.

QTL Analysis for Traits Associated with Feeding Value of Straw in Rice (Oryza sativa L.)

Genetic improvement of the digestibility of rice straw for increasing the utilization of the whole rice plant as feedstuffs is an important way to solve the feedstuffs shortage in southeastern China. To elucidate the genetic basis of the traits affecting the digestibility of rice straw, a rice population of 111 recombinant inbred lines （RILs） derived from a cross of Nekken 2xGaya was used to map the quantitative traits loci （QTLs） for in vitro dry matter digestion （IVDMD）, the percentages of nonstructural carbohydrate （NSC） and acid detergent fiber （exclusive of residual ash, ADFom） in 2005 and 2006. IVDMD was positively correlated with NSC, and negatively correlated with ADFom. A total of 16 QTLs were detected in the two years, and the amounts of variation explained by individual QTLs ranged from 6.9% to 15.5%. Some QTLs for IVDMD and ADFom on chromosome 2 were detected in the two years. On chromosome 2, the interval RM475-RM3515 contained QTLs for IVDMD in the two years and for NSC in 2006 only, while the interval RM3874-RM5305 influenced ADFom in the two years and NSC in 2005 only. At those loci, Gaya contributed favorable alleles to IVDMD and NSC, while Nekken 2 contributed positive alleles to ADFom.

POSITIVE SOLUTIONS TO THE p-LAPLACIAN WITH SINGULAR WEIGHTS

By the Mountain Pass Theorem, we study existence and multiplicity of posi- tive solutions of p-laplacian equation of the form - △pu =λf （x, u）, the nonlinearity f （x, u） grows as u^δ at infinity with a singular coefficient, where a ∈ （p - 1,p＊ - 1）. To manage the asymptotic behavior of its positive solutions with respect to λ, we establish a new Liouville-type theorem for the p-Laplacian operator.

Differential Responses of NHX1 and SOS1 Gene Expressions to Salinity in two Miscanthus sinensis Anderss.Accessions with Different Salt Tolerance

The lignocellulosic crop Miscanthus spp.has been identified as a good candidate for biomass production.The responses of Miscanthus sinensis Anderss.to salinity were studied to satisfy the needs for high yields in marginal areas and to avoid competition with food production.The results indicated that the relative advantages of the tolerant accession over the sensitive one under saline conditions were associated with restricted Na^(+)accumulation in shoots.Seedlings of two accessions(salt-tolerant‘JM0119’and salt-sensitive‘JM0099’)were subjected to 0(control),100,200,and 300 mM NaCl stress to better understand the salt-induced biochemical responses of genes involved in Na^(+)accumulation in M.sinensis.The adaptation responses of genes encoding for Na^(+)/H^(+)antiporters,NHX1 and SOS1 to NaCl stress were examined in JM0119 and JM0099.The cDNA sequences of genes examined were highly conserved among the relatives of M.sinensis based on the sequencing on approximate 600 bp-long cDNA fragments obtained from degenerate PCR.These salt-induced variations of gene expression investigated by quantitative real-time PCR provided evidences for insights of the molecular mechanisms of salt tolerance in M.sinensis.The expression of NHX1 was up-regulated by salt stress in JM0119 shoot and root tissues.However,it was hardly affected in JM0099 shoot tissue except for a significant increase at the 100 mM salt treatment,and it was salt-suppressed in the JM0099 root tissue.In the root tissue,the expression of SOS1 was induced by the high salt treatment in JM0119 but repressed by all salt treatments in JM0099.Thus,the remarkably higher expression of NHX1 and SOS1 were associated with the resistance to Na^(+)toxicity by regulation of the Na^(+)influx,efflux,and sequestration under different salt conditions.

Ethanol extracts of Hizikia fusiforme induce apoptosis in human prostate cancer PC3 cells via modulating a ROS-dependent pathway

Objective:To investigate whether ethanol extracts of Hizikia fusiforme could induce apoptosis in human prostate cancer PC3 cells.Methods:Cell viability was evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide.Apoptosis and mitochondrial membrane potential(MMP)were measured using flow cytometry in PC3 cells.DNA damage was assessed by nuclear staining and DNA fragmentation assay.Expressions of apoptosis-associated proteins were determined by Western blotting assays.Activities of caspase-3,-8,and-9 were determined by colorimetric assay.Moreover,intracellular reactive oxygen species(ROS)generation was detected using a flow cytometer and fluorescence microscope.Results:Treatment of PC3 cells with ethanol extracts of Hizikia fusiforme inhibited proliferation,which was associated with induction of apoptosis,and accompanied by increased expression of Fas,Fas-ligand(Fas L),Bax and t Bid,and decreased expression of Bcl-2.In addition,ethanol extracts of Hizikia fusiforme reduced c-Flip expression and activated caspase-8,-9 and-3,resulting in an increase in poly(ADP-ribose)polymerase(PARP)cleavage.However,in the presence of a pan-caspase inhibitor,ethanol extracts of Hizikia fusiforme-mediated growth inhibition and apoptosis were significantly attenuated.Ethanol extracts of Hizikia fusiforme also destroyed the integrity of mitochondria due to the loss of MMP,leading to cytosolic release of cytochrome c.Moreover,the levels of ROS were markedly increased by treatment with ethanol extracts of Hizikia fusiforme,which was significantly suppressed by the ROS scavenger N-acetyl-L-cysteine.Further investigation of whether ethanol extracts of Hizikia fusiforme-induced apoptosis was related to the generation of ROS was conducted and the results showed that N-acetyl-L-cysteine fully blocked ethanol extracts of Hizikia fusiforme-induced apoptotic events including loss of MMP,activation of caspase-3,the cytosolic release of cytochrome c and cytotoxicity.Conclusions:Ethanol extracts of Hizikia fusiforme have chemopreventive potential via induction of ROS-dependent apoptosis.Therefore,ethanol extracts of Hizikia fusiforme may be useful for developing effective and selective natural sources to inhibit cancer cell proliferation.

Trace Metal Contamination of Sediments in Naviundu River Basin, Luano and Ruashi Rivers and Luwowoshi Spring in Lubumbashi City, Democratic Republic of Congo

As （Arsenic）, Ba （Barium）, Cr （Chromium）, Cu （Copper）, Fe （Iron）, Mne （Manganese）, Pb （Lead） and Zn （Zinc） concentrations were investigated in sediments collected from fifteen sampling locations in Naviundu river basin, Luano and Ruashi rivers and Luwowoshi spring in Lubumbashi city from February to April 2016. Chemical analyses of the samples were carried out using a portable X-ray fluorescence spectrometer. Mean pH values ranged from 4.2 to 5.8. The sediment highest mean levels of As （40 mg·kg^-1·dw） and Cu （3,723 mg·kg^-1 ·dw） were noted in Chemaf （Chemicals of Africa） hydrometallurgical plant effluent, those of Pb （51.5mg·kg^-1·dw） and Zn （335mg·kg^-1·dw） were recorded in Kabecha river and those of Ba （657.5mg·kg^-1·dw）, Cr （75 mg·kg^-1·dw）, Mn （591 mg·kg^-1·dw） and Fe （88,450mg·kg^-1·dw） were respectively found in Naviundu river at Cimenkat （Katanga＇s Cement factory） exit, Naviundu river under bridge on De Plaines avenue, Mukulu river and Foire channel. Mean As, Cu and Zn levels of sediments exceeded the corresponding SQGs （Sediment Quality Guidelines）, PELs （Probable Effect Levels） in some of the studied rivers. They could have adverse effects on aquatic organisms in those rivers and on the health of people who depend on the rivers for water supply, irrigation and/or recreation.

STABILITY OF TIME-PERIODIC TRAVELING FRONTS IN BISTABLE REACTION-ADVECTION-DIFFUSION EQUATIONS

This paper is concerned with the global exponential stability of time periodic traveling fronts of reaction-advection-diffusion equations with time periodic bistable nonlinearity in infinite cylinders. It is well known that such traveling fronts exist and are asymptotically stable. In this paper, we further show that such fronts are globally exponentially stable. The main difficulty is to construct appropriate supersolutions and subsolutions.

Elastic and inelastic positron-helium scattering

Elastic and inelastic positron-helium scatterings have been investigated with the coupled-channel optical method （CCO）. Ionization continuum and positronium formation channels are included via a complex equivalent-local optical potential. Calculations are reported of cross sections of elastic scattering, total excitation and n=2, 3, and 4 excitations of ground-state helium for incident energies from 30 eV to 400 eV. The present calculation shows that the ionization and Ps-formation channels significantly affect the cross sections of elastic and inelastic positron-helium scatterings.

SOLUTIONS TO NONLINEAR ELLIPTIC EQUATIONS WITH A GRADIENT

In this article, we consider existence and nonexistence of solutions to problem {-△pu＋g（x,u）｜↓△｜^p=f in -Ω,u=0 on Ω with 1〈p〈∞ where f is a positive measurable function which is bounded away from 0 in Ω, and the domain Ω is a smooth bounded open set in R^N（N≥2）. Especially, under the condition that g（x, s） = 1/｜s｜^α （α〉0） is singular at s = 0, we obtain that α 〈 p is necessary and sufficient for the existence of solutions in W0^1,p（Ω） to problem （0.1） when f is sufficiently regular.

Modulation of Void Motion Behavior in a Magnetized Dusty Plasma

Based on fluid equations, we show a time-dependent self-consistent nonlinear model for void formation in magnetized dusty plasmas. The cylindrical configuration is applied to better illustrate the effects of the static magnetic field, considering the azimuthal motion of the dusts. Tile nonlinear evolution of the dust void and the rotation of the dust particles are then investigated numerically. The results show that, similar to the unmagnetized one-dimensional model, the radial ion dragplays a crucial role in the evolution of the void. Moreover, the dust rotation is driven by the azimuthal ion drag force exerting on the dust. As the azimuthal component of ion velocity increases linearly with the strength of the magnetic field, tile azimuthal component of dust velocity increases synchronously. Moreover, the angular velocity gradients of the dust rotation show a sheared dust flow around the void.

Positron Impact Transitions of Atomic Sodium

We present a new investigation of elastic and inelastic positron-sodium scattering by using the coupled-channel optical method(CCO)at an incident energy region of 2–100 eV.The ionization continuum and positronium formation channels have been included via a complex equivalent-local optical potential.The present calculations are compared with available theoretical data and our investigation indicates that the inclusion of ionization and Ps-formation channels in the present calculations has a significant effect on the cross sections of elastic and inelastic positron-sodium scattering at lower energies.

Positronium Formation in Positron-Lithium Scattering

The positronium formation process in positron scattering with atomic lithium is investigated using the coupled-channel optical method.The cross sections of positronium formation into the n=1 and n=2 levels from 2 to 60 eV are reported.The present results show reasonable agreement with the available experimental measurements and theoretical calculations.

BOUNDARY BLOW-UP RATE OF THE LARGE SOLUTION FOR AN ELLIPTIC COOPERATIVE SYSTEM

In this article we consider positive large solution of cooperative systems of the form -△u1=λ1u1 + a1u1u2^q1 -b1(x)u1^p1+1,-△u2=λ2u2 + a2u1^q2u2 -b2(x)u2^p2+1 in a bounded smooth domainΩ■ R^N(λi ∈ R, ai, bi>0, 0 < qi < pj, i, j ∈{1, 2}, i ≠ j), Based on the construction of certain sup and sub-solution, we show existence, uniqueness and blow-up rate of the large solution.

Influence of Excitation Pulse Width on the Second-Order Correlation Functions of the Exciton-Biexciton Emissions

We investigate theoretically the population dynamics and the second-order correlation functions of photon emissions from the biexciton-exciton system of a single quantum dot with excitation from pulses to continuous wave. The dynamic equations of the correlation functions are deduced by applying quantum regression theorem to optical Bloch equations. The influences of excitation pulse width on the correlation function have been discussed in detail.

Study on the Tolerance Mechanism of Alkaline Soil-Tolerant Wild Plants

The soil in many agricultural areas, including large parts of China, is becoming increasingly alkaline as a result of exploitation of soil resources. The soil becomes alkaline as a result of hydrolysis of two carbonates (NaH-

Light-Induced Mid-Infrared Emission of Liquid Carbon Tetrachloride and Benzene

Light-induced infrared emission spectroscopy (LIRES) is a novel technique that permits to receive high-quality spectra in the mid-infrared region. Low-intensity visible light connected to a highly sensitive FTIR spectrometer is more advantageous for studying any samples, including biological samples without any damage. This technique permits obtaining unique information on the molecule structure via vibrational excitation fundamental frequencies, overtones, and combination modes. It also enables a direct observation of vibrational radiation transitions in vibrationally excited molecules as well as the channels of vibration energy redistribution, which is not allowed with any other method. In this work, the LIRES is being tested as a technique for studying of vibrationally-excited molecules of carbon tetrachloride and benzene in the liquid phase. On the other hand, using transparent liquids, we had tried to understand some of the physical phenomena that can drive emission in mid-IR. The characteristics of the infrared emission of both liquid species produced by different wavelength radiation from various types of light systems (100 - watt Xe-lamp and Nd:YAG laser;lambda = 1064 nm (8 mW) and lambda = 532 nm (4 mW)) are presented. We demonstrated that the IR-signal, as well as spectral properties of carbon tetrachloride and benzene, was dependent on the wavelength and power of excitation beam. Results obtained with different light sources show that the visible light produces a nonlinear IR-emission signal in transparent liquids. We believe that the visible light is the source of the nonlinear response and is producing the vibration excitation as well as photostimulated transformations of the molecules possessing the high activity for the nonlinear response.