Knowledge, Attitude and Practice of Malawian Farmers on Pre- and Post-Harvest Crop Management to Mitigate Aflatoxin Contamination in Groundnut, Maize and Sorghum—Implication for Behavioral Change

A knowledge, attitude and practice (KAP) study was conducted in three districts of Malawi to test whether the training had resulted in increased knowledge and adoption of recommended pre- and post-harvest crop management practices, and their contribution to reducing aflatoxin contamination in groundnut, maize and sorghum. The study was conducted with 900 farmers at the baseline and 624 farmers at the end-line, while 726 and 696 harvested crop samples were collected for aflatoxin testing at the baseline and end-line, respectively. Results show that the knowledge and practice of pre- and post-harvest crop management for mitigating aflatoxin were inadequate among the farmers at the baseline but somewhat improved after the training as shown at the end-line. As a result, despite unfavorable weather, the mean aflatoxin contamination level in their grain samples decreased from 83.6 to 55.8 ppb (p < 0.001). However, it was also noted that increased knowledge did not significantly change farmers’ attitude toward not consuming grade-outs because of economic incentive incompatibility, leaving potential for improving the practices further. This existing gap in the adoption of aflatoxin mitigation practices calls for approaches that take into account farmers needs and incentives to attain sustainable behavioral change

Do Commercialization and Mechanization of a “Women’s Crop” Disempower Women Farmers? Evidence from Zambia and Malawi

It is widely believed that commercialization and mechanization of food crops lead to disempowering women as men take over control from women. We argue that women are not necessarily discontent in the face of the agrarian transformation. By collecting sex-disaggregated panel data and applying a ‘women’s crop tool’, we analyze and rethink the implication of agricultural commercialization for intra-household gender relation among smallholder farmers through research on groundnut producers in southern Africa, where groundnut is largely regarded as a ‘women’s crop’. In addition to examining the effect of commercialization in Zambia and Malawi, small-scale post-harvest mechanization was provided experimentally to selected farmers in Zambia. The panel regression results show that commercialization did not lead to disempowering women in either country, which is consistent with the qualitative discussions with farmers held before the baseline surveys. Furthermore, by combining PSM and DID methods, it was found that machine shelling did not disempower women farmers either. The finding provides insights into how gender relation among smallholders is affected at the initial stage of commercialization and mechanization of ‘women’s crops’

A Novel Technology for Complex Rheological Measurements

As the UK nuclear industry embarks on a second phase of nuclear power generation, the industry is faced with numerous sludge and slurry challenges associated with the decommissioning and clean-up of historical nuclear sites. The remediation of Sellafield, the largest nuclear site in the UK, is anticipated to cost GBP 53bn over the next 100 years. Substantial cost is associated with the clean-up, transfer and safe storage of legacy particulate wastes encountered in ponds, silos, highly active storage tanks and many more large tanks on site. To develop suitable design strategies for the mobilization and transfer of sludge, the rheology of the sludge should be accurately determined. The current work demonstrates the use of a Quartz Crystal Microbalance to measure sludge rheology, specifically the shear yield stress. The device is simple to operate with no mechanical parts, small and portable enabling deployment into limited access areas, and eliminates the need for operator sampling and laboratory measurement. The measurement principle relates to the resonance frequency and motional resistance of a piezo-electric sensor as the sensor is submerged in the desired test material. The air-to-sample frequency and resistance shifts are shown to correlate with the shear yield stress of the suspension as measured by conventional vane viscometry. As the particle network stiffens (increased yield stress), the sensor motional resistance and its resonant frequency become more positive These characteristic responses and their correlation to the shear yield stress have been confirmed for a range of particle suspensions

Quartz crystal microbalance as a device to measure the yield stress of colloidal suspensions

The application of quartz crystal microbalance (QCM) as a device to measure the rheology of colloidal suspensions has been studied. Using a commercial dip-probe QCM, the yield stress of magnesium hydroxide suspensions has been correlated to the resonance properties of a 5 MHz AT-cut quartz sensor. A stable resonance baseline was first established in air before submerging the sensor into the colloidal suspension. The response of the sensor resistance was shown to correlate to changes in the suspension yield stress, while the frequency response was found to result from more complex contact mechanics and suspension viscoelasticity contributions. Since the QCM is a relatively simple technique with no mechanically moving parts, this approach offers the potential for rapid in situ rheology assessment

Select pyrimidinones inhibit the propagation of the malarial parasite, Plasmodium falciparum

Plasmodium falciparum, the Apicomplexan parasite that is responsible for the most lethal forms of human malaria, is exposed to radically different environments and stress factors during its complex lifecycle. In any organism, Hsp70 chaperones are typically associated with tolerance to stress. We therefore reasoned that inhibition of P. falciparum Hsp70 chaperones would adversely affect parasite homeostasis. To test this hypothesis, we measured whether pyrimidinone-amides, a new class of Hsp70 modulators, could inhibit the replication of the pathogenic P. falciparum stages in human red blood cells. Nine compounds with IC50 values from 30 nM to 1.6 μM were identified. Each compound also altered the ATPase activity of purified P. falciparum Hsp70 in single-turnover assays, although higher concentrations of agents were required than was necessary to inhibit P. falciparum replication. Varying effects of these compounds on Hsp70s from other organisms were also observed. Together, our data indicate that pyrimidinone-amides constitute a novel class of anti-malarial agents. © 2009 Elsevier Ltd. All rights reserved

Isoscalar giant monopole strength in 58^{58}Ni, 90^{90}Zr, 120^{120}Sn and 208^{208}Pb

Inelastic $\alpha$-particle scattering at energies of a few hundred MeV and very-forward scattering angles including $0^\circ$ has been established as a tool for the study of the isoscalar giant monopole (IS0) strength distributions in nuclei. An independent investigation of the IS0 strength in nuclei across a wide mass range was performed using the $0^\circ$ facility at iThemba Laboratory for Accelerator Based Sciences (iThemba LABS), South Africa, to understand differences observed between IS0 strength distributions in previous experiments performed at the Texas A\&M University (TAMU) Cyclotron Institute, USA and the Research Center for Nuclear Physics (RCNP), Japan. The isoscalar giant monopole resonance (ISGMR) was excited in $^{58}$Ni, $^{90}$Zr, $^{120}$Sn and $^{208}$Pb using $\alpha$-particle inelastic scattering with $196$ MeV $\alpha$ beam and scattering angles $\theta_{\text{Lab}} = 0^\circ$ and $4^\circ$. The K$600$ magnetic spectrometer at iThemba LABS was used to detect and momentum analyze the inelastically scattered $\alpha$ particles. The IS0 strength distributions in the nuclei studied were deduced with the difference-of-spectra (DoS) technique including a correction factor for the $4^\circ$ data based on the decomposition of $L > 0$ cross sections in previous experiments. IS0 strength distributions for $^{58}$Ni, $^{90}$Zr, $^{120}$Sn and $^{208}$Pb are extracted in the excitation-energy region $E_{\rm x} = 9 - 25$ MeV.Using correction factors extracted from the RCNP experiments, there is a fair agreement with their published IS0 results. Good agreement for IS0 strength in $^{58}$Ni is also obtained with correction factors deduced from the TAMU results, while marked differences are found for $^{90}$Zr and $^{208}$Pb.Comment: 12 pages, 10 figures, regular article submitted to PR

Fine structure of the isoscalar giant monopole resonance in 58^{58}Ni, 90^{90}Zr, 120^{120}Sn and 208^{208}Pb

Over the past two decades high energy-resolution inelastic proton scattering studies were used to gain an understanding of the origin of fine structure observed in the isoscalar giant quadrupole resonance (ISGQR) and the isovector giant dipole resonance (IVGDR). Recently, the isoscalar giant monopole resonance (ISGMR) in $^{58}$Ni, $^{90}$Zr, $^{120}$Sn and $^{208}$Pb was studied at the iThemba Laboratory for Accelerator Based Sciences (iThemba LABS) by means of inelastic $\alpha$-particle scattering at very forward scattering angles (including $0\circ$). The good energy resolution of the measurement revealed significant fine structure of the ISGMR.~To extract scales by means of wavelet analysis characterizing the observed fine structure of the ISGMR in order to investigate the role of different mechanisms contributing to its decay width. Characteristic energy scales are extracted from the fine structure using continuous wavelet transforms. The experimental energy scales are compared to different theoretical approaches performed in the framework of quasiparticle random phase approximation (QRPA) and beyond-QRPA including complex configurations using both non-relativistic and relativistic density functional theory. All models highlight the role of Landau fragmentation for the damping of the ISGMR especially in the medium-mass region. Models which include the coupling between one particle-one hole (1p-1h) and two particle-two hole (2p-2h) configurations modify the strength distributions and wavelet scales indicating the importance of the spreading width. The effect becomes more pronounced with increasing mass number. Wavelet scales remain a sensitive measure of the interplay between Landau fragmentation and the spreading width in the description of the fine structure of giant resonances.Comment: 13 pages,7 figures, regular articl