Pre-Exposure to 50 Hz Magnetic Fields Modifies Menadione-Induced Genotoxic Effects in Human SH-SY5Y Neuroblastoma Cells

BACKGROUND: Extremely low frequency (ELF) magnetic fields (MF) are generated by power lines and various electric appliances. They have been classified as possibly carcinogenic by the International Agency for Research on Cancer, but a mechanistic explanation for carcinogenic effects is lacking. A previous study in our laboratory showed that pre-exposure to ELF MF altered cancer-relevant cellular responses (cell cycle arrest, apoptosis) to menadione-induced DNA damage, but it did not include endpoints measuring actual genetic damage. In the present study, we examined whether pre-exposure to ELF MF affects chemically induced DNA damage level, DNA repair rate, or micronucleus frequency in human SH-SY5Y neuroblastoma cells. METHODOLOGY/PRINCIPAL FINDINGS: Exposure to 50 Hz MF was conducted at 100 µT for 24 hours, followed by chemical exposure for 3 hours. The chemicals used for inducing DNA damage and subsequent micronucleus formation were menadione and methyl methanesulphonate (MMS). Pre-treatment with MF enhanced menadione-induced DNA damage, DNA repair rate, and micronucleus formation in human SH-SY5Y neuroblastoma cells. Although the results with MMS indicated similar effects, the differences were not statistically significant. No effects were observed after MF exposure alone. CONCLUSIONS: The results confirm our previous findings showing that pre-exposure to MFs as low as 100 µT alters cellular responses to menadione, and show that increased genotoxicity results from such interaction. The present findings also indicate that complementary data at several chronological points may be critical for understanding the MF effects on DNA damage, repair, and post-repair integrity of the genome

Social Safety Nets for Food and Nutritional Security in India

This paper brings together existing literature on the Mahatma Gandhi National Rural Employment Guarantee Act (MGNRGEA) and the Public Distribution System (PDS) in India, offering a narrative review of the evidence on impacts on food security, health and nutrition of beneficiaries. Both programs operate on a large scale and have the capacity to impact the factors leading to undernutrition. It is evident that despite the deficiencies in implementation, both the MGNREGA and the PDS are inclusive and reach the poor and the marginalized who are likely to also experience greater undernutrition and poor health. Data challenges have however prevented researchers from conducting studies that assess the ultimate impact of these two large-scale programs on health and nutrition. The evidence that exists suggests largely positive impacts indicating a clear potential to make these programs more nutrition sensitive not just by incorporating elements that would explicitly address nutritional concerns but also by directing specific attention to innovations that strengthen critical complementarities and synergies that exist between the two programs

A unifying model for reconstructing radiosensitivity from micronucleus formation, apoptosis and abnormal morphology

At present micronucleus data cannot predict cellular radiosensitivity. The inclusion of data from apoptosis and abnormal morphology has not entirely resolved this problem. Here, we assess the probability of cell death arising from events other than micronucleation, apoptosis and abnormal morphology (i.e. lesions not detected by these damage assays) Poe, for its ability to reflect intrinsic cellular radiosensitivity. Analysis of data from 17 cell lines used in two separate studies, spanning a wide range of radiosensitivity (0.09≤SF2≤0.70), confirmed our previous observation that cell death due to undetected lesions depends on the irradiation dose and is cell type-specific. We further demonstrate that Poe accounts for inter-cell line differences in translating irradiation damage into cell death. Data from any two of micronucleus formation, apoptosis and abnormal cell morphology, fitted to the Poe model, adequately predict clonogenic survival, and measurement of additional damage endpoints is not required. The Poe model may benefit patient selection in situations where colony formation of primary tumour cultures fails to arrive at estimates of radiosensitivity.Articl

Testing the Performance of Fresh Tomato Markets Following Import Trade Liberalization in Ghana:

A chronic issue of policy concern in Ghana is the implication of trade liberalization for the performance of agricultural markets. Much public opinion in Ghana blames the perennially volatile, highly dispersed and uncompetitive prices of tomato on the importation of cheap tomato products into Ghana. There is however insufficient empirical evidence to confirm this opinion. To the best of our knowledge, no empirical research on the performance of tomato markets in the post-liberalization period in Ghana has ever been conducted. This paper therefore seeks to provide evidence on the performance of Ghana’s tomato markets following trade liberalization. Such evidence is useful in assessing the implication of liberalization for the performance of Ghana’s food commodity markets. We used the threshold autoregressive model to analyse wholesale prices of fresh tomato gathered from four major markets in Ghana. The findings reveal that price transmission and adjustments parameters, key indicators of market performance, declined following the actual liberalization of Ghana’s agricultural markets. It appears that the underlying factors responsible for the performance of the tomato markets deteriorated over the period of the study. This may be evidence of liberalization being partly responsible for the marketing problem of tomato in Ghana.Key Words/Descriptors: Trade Liberalization, Price Transmission, MarketIntegration, Tomato, Commodities Market