Farmer Field Schools in Expanding Cultivation to Newly Reclaimed Land in Ismailia in Egypt

The use of irrigation systems is expanding in Egypt to facilitate cultivation on sandy areas that were previously desert. Many of the farmers starting on the new areas are undergraduates and others with no background in farming. Much support is required when they start farming. In addition, farmers moving to the new lands from the Nile Delta meet completely new challenges because the poor and infertile sandy soils require different management from the clay soils at the Delta. Ismailia Agricultural Research Station (IARS) of the Agricultural Research Center of Egypt focuses on research on how to cultivate the newly reclaimed sandy soils. The Ministry for Foreign Affairs of Finland has supported the research and advisory work of IARS for the last fifteen years through the Egypt - Finland Agricultural Research Project (EFARP). This has been implemented as a twinning project between the Agricultural Research Center of Egypt and the equivalent organisation in Finland: MTT Agrifood Research Finland. In this paper we describe the Farmer Field School (FFS) approach applied to forage and animal production on smallholder farms from 2000-2004

Synergistic effect of co-exposure to carbon black and Fe2O3 nanoparticles on oxidative stress in cultured lung epithelial cells

BACKGROUND: There is a need to better understand synergism in the biological effects of particles composed of multiple substances. The objective of this study was to determine if the oxidative stress in cultured cells caused by co-exposure to carbon black and Fe(2)O(3 )nanoparticles was significantly greater than the additive effects of exposure to either type of particles alone; and to determine a possible cause for such synergistic effect if one was found. Cultured A549 human lung epithelial cells were exposed to (1) carbon black nanoparticles alone, (2) Fe(2)O(3 )nanoparticles alone, and (3) both types of particles simultaneously. Protein oxidation, lipid peroxidation, and cellular uptake of Fe in these cells were measured after 25 hours of exposure. The reduction of solubilized Fe(3+ )by the carbon black nanoparticles was measured separately in a cell-free assay, by incubating the carbon black and the Fe(2)O(3 )nanoparticles in 0.75 M sulfuric acid at 40°C and measuring the amount of reduced Fe(3+ )at different time points up to 24 hours. RESULTS: Cells exposed to carbon black particles alone did not show protein oxidation, nor did the cells exposed to Fe(2)O(3 )particles alone, relative to the control. However, cells co-exposed to both carbon black and Fe(2)O(3 )particles showed up to a two-fold increase in protein oxidation relative to the control. In addition, co-exposure induced significant lipid peroxidation, although exposure to either particle type alone did not. No significant difference in cellular iron uptake was found between single exposure and co-exposure, when the Fe(2)O(3 )dosing concentration was the same in each case. In the cell-free assay, significant reduction of Fe(3+ )ions by carbon black nanoparticle was found within 2 hour, and it progressed up to 24 hours. At 24 hours, the carbon black nanoparticles showed a reductive capacity of 0.009 g/g, defined as the mass ratio of reduced Fe(3+ )to carbon black. CONCLUSION: Co-exposure to carbon black and Fe(2)O(3 )particles causes a synergistic oxidative effect that is significantly greater than the additive effects of exposures to either particle type alone. The intracellular redox reaction between carbon black and Fe(3+ )is likely responsible for the synergistic oxidative effect. Therefore elemental carbon particles and fibres should be considered as potential reducing agents rather than inert materials in toxicology studies. Acidified cell organelles such as the lysosomes probably play a critical role in the solubilization of Fe(2)O(3). Further research is necessary to better understand the mechanisms

Grid impedance estimation for islanding detection and adaptive control of converters

The grid impedance is time varying due to the changing structure of the power system configuration and it can have a considerable influence on the control and stability of grid connected converters. This paper presents an online grid impedance estimation method using the output switching current ripple of a SVPWM based grid connected converter. The proposed impedance estimation method is derived from the discretised system model using two consecutive samples within the switching period. The estimated impedance is used for islanding detection and online current controller parameter adaptation. Theoretical analysis and MATLAB simulation results are presented to verify the proposed method. The effectiveness of the grid impedance estimator is validated using experimental results

Quality Evaluation of Feed Resources at the Newly Reclaimed Area in Egypt

The objective of this study was to examine the productivity of Egyptian clover (Trifolium alexandrinum L.) interseeded with ryegrass (Lolium multiflorum) and alfalfa (Medicaga sativa L.). These species were planted in newly reclaimed land in Ismailia, Egypt under two fertilization systems; organic (OF) or chemical (CF) during winter season of (1994-1995) using a split plot design. Feeding quality of forages was evaluated by conducting digestibility trials with rams and feeding trials with growing lambs where forage was offered ad. libitum with 1% of LBW concentrate. Productivity data indicated that organic fertilization yielded significantly more DM. Chemical analysis showed that DM content with (CF) was higher than with (OF) and it was found that alfalfa had higher CP content than that of E. Clover mixture. Digestibility of nutrients was higher with (CF) than with (OF) and it was found that CP was more digested in alfalfa than the Egyptian clover mixture. TDN values for both forages were determined by proximate analysis. Group of lambs fed chemically fertilized alfalfa attained significantly better weight gain which was attributed to high forage DM intake

Beyond Implications and Applications: the Story of ‘Safety by Design’

Using long-term anthropological observations at the Center for Biological and Environmental Nanotechnology in Houston, Texas, the article demonstrates in detail the creation of new objects, new venues and new modes of veridiction which have reoriented the disciplines of materials chemistry and nanotoxicology. Beginning with the confusion surrounding the meaning of ‘implications’ and ‘applications’ the article explores the creation of new venues (CBEN and its offshoot the International Council on Nanotechnology); it then demonstrates how the demands for a responsible, safe or ethical science were translated into new research and experiment in and through these venues. Finally it shows how ‘safety by design’ emerged as a way to go beyond implications and applications, even as it introduced a whole new array of controversies concerning its viability, validity and legitimacy

Readiness for self-directed learning among King Abdulaziz University medical students

Background: To determine readiness for self-directed learning (SDL) among medical students enrolled at King Abdulaziz University (KAU) in Jeddah, Saudi Arabia, as well as identify demographic characteristics that might affect or control such readiness.Methods: Medical students at all levels of training were asked to participate in a study in the form of a self-response questionnaire via emailed link (Gugliemino’s Self-Directed Learner Readiness Scale [SDLRS]). This instrument was designed to measure the complex attitudes, skills and characteristics that comprise an individual’s current level of readiness to manage his or her own learning. Data were analysed using SPSS, and mean, median and total scores were calculated and compared.Results: Of more than 1900 medical students at the KAU Faculty of Medicine, 192 students responded to the self-response questionnaire (see appendix). Results suggested that readiness for SDL is below average for more than 99% of medical studentsConclusions: Our study showed that further evaluation of our students' readiness for SDL is required, as well as exploration and implementation of tools for improving skill and knowledge development, to enable students to develop a lifelong learning attitude

Expert consensus on an in vitro approach to assess pulmonary fibrogenic potential of aerosolized nanomaterials

The increasing use of multi-walled carbon nanotubes (MWCNTs) in consumer products and their potential to induce adverse lung effects following inhalation has lead to much interest in better understanding the hazard associated with these nanomaterials (NMs). While the current regulatory requirement for substances of concern, such as MWCNTs, in many jurisdictions is a 90-day rodent inhalation test, the monetary, ethical, and scientific concerns associated with this test led an international expert group to convene in Washington, DC, USA, to discuss alternative approaches to evaluate the inhalation toxicity of MWCNTs. Pulmonary fibrosis was identified as a key adverse outcome linked to MWCNT exposure, and recommendations were made on the design of an in vitro assay that is predictive of the fibrotic potential of MWCNTs. While fibrosis takes weeks or months to develop in vivo, an in vitro test system may more rapidly predict fibrogenic potential by monitoring pro-fibrotic mediators (e.g., cytokines and growth factors). Therefore, the workshop discussions focused on the necessary specifications related to the development and evaluation of such an in vitro system. Recommendations were made for designing a system using lung-relevant cells co-cultured at the air–liquid interface to assess the pro-fibrogenic potential of aerosolized MWCNTs, while considering human-relevant dosimetry and NM life cycle transformations. The workshop discussions provided the fundamental design components of an air–liquid interface in vitro test system that will be subsequently expanded to the development of an alternative testing strategy to predict pulmonary toxicity and to generate data that will enable effective risk assessment of NMs

Assessing the Completeness of Reporting in Preclinical Oncolytic Virus Therapy Studies

Irreproducibility of preclinical findings could be a significant barrier to the “bench-to-bedside” development of oncolytic viruses (OVs). A contributing factor is the incomplete and non-transparent reporting of study methodology and design. Using the NIH Principles and Guidelines for Reporting Preclinical Research, a core set of seven recommendations, we evaluated the completeness of reporting of preclinical OV studies. We also developed an evidence map identifying the current trends in OV research. A systematic search of MEDLINE and Embase identified all relevant articles published over an 18 month period. We screened 1,554 articles, and 236 met our a priori-defined inclusion criteria. Adenovirus (43%) was the most commonly used viral platform. Frequently investigated cancers included colorectal (14%), skin (12%), and breast (11%). Xenograft implantation (61%) in mice (96%) was the most common animal model. The use of preclinical reporting guidelines was listed in 0.4% of articles. Biological and technical replicates were completely reported in 1% of studies, statistics in 49%, randomization in 1%, blinding in 2%, sample size estimation in 0%, and inclusion/exclusion criteria in 0%. Overall, completeness of reporting in the preclinical OV therapy literature is poor. This may hinder efforts to interpret, replicate, and ultimately translate promising preclinical OV findings

The effect of titanium dioxide nanoparticles on pulmonary surfactant function and ultrastructure

<p>Abstract</p> <p>Background</p> <p>Pulmonary surfactant reduces surface tension and is present at the air-liquid interface in the alveoli where inhaled nanoparticles preferentially deposit. We investigated the effect of titanium dioxide (TiO₂) nanosized particles (NSP) and microsized particles (MSP) on biophysical surfactant function after direct particle contact and after surface area cycling <it>in vitro</it>. In addition, TiO₂effects on surfactant ultrastructure were visualized.</p> <p>Methods</p> <p>A natural porcine surfactant preparation was incubated with increasing concentrations (50-500 μg/ml) of TiO₂NSP or MSP, respectively. Biophysical surfactant function was measured in a pulsating bubble surfactometer before and after surface area cycling. Furthermore, surfactant ultrastructure was evaluated with a transmission electron microscope.</p> <p>Results</p> <p>TiO₂NSP, but not MSP, induced a surfactant dysfunction. For TiO₂NSP, adsorption surface tension (γ_ads) increased in a dose-dependent manner from 28.2 ± 2.3 mN/m to 33.2 ± 2.3 mN/m (p < 0.01), and surface tension at minimum bubble size (γ_min) slightly increased from 4.8 ± 0.5 mN/m up to 8.4 ± 1.3 mN/m (p < 0.01) at high TiO₂NSP concentrations. Presence of NSP during surface area cycling caused large and significant increases in both γ_ads(63.6 ± 0.4 mN/m) and γ_min(21.1 ± 0.4 mN/m). Interestingly, TiO₂NSP induced aberrations in the surfactant ultrastructure. Lamellar body like structures were deformed and decreased in size. In addition, unilamellar vesicles were formed. Particle aggregates were found between single lamellae.</p> <p>Conclusion</p> <p>TiO₂nanosized particles can alter the structure and function of pulmonary surfactant. Particle size and surface area respectively play a critical role for the biophysical surfactant response in the lung.</p