RESUMEN
Recurring food crises endanger the livelihoods of millions of households in developing countries around the globe. Owing to the importance of this issue, we explore recent changes in food security between the years 2004 and 2010 in a rural district in Northeastern South Africa. Our study window spans the time of the 2008 global food crises and allows the investigation of its impacts on rural South African populations. Grounded in the sustainable livelihood framework, we examine differences in food security trajectories among vulnerable sub populations. A unique panel data set of 8,147 households, provided by the Agincourt Health and Demographic Surveillance System (Agincourt HDSS), allows us to employ a longitudinal multilevel modeling approach to estimate adjusted growth curves for the differential change in food security across time. We observe an overall improvement in food security that leveled off after 2008, most likely resulting from the global food crisis. In addition, we discover significant differences in food security trajectories for various sub populations. For example, female-headed households and those living in areas with better access to natural resources differentially improved their food security situation, compared to male-headed households and those households with lower levels of natural resource access. However, former Mozambican refugees witnessed a decline in food security. Therefore, poverty alleviation programs for the Agincourt region should work to improve the food security of vulnerable households, such as former Mozambican refugees.
RESUMEN
The etiology of multiple sclerosis (MS) has not been fully elucidated, however evidence supports an autoimmune disease model notable for the infiltration of pro-inflammatory immune cells into sites of active demyelination and axonal injury. Previous findings demonstrate that neutralization of Nogo, a protein originally identified as a myelin-associated inhibitor (MAI) of axon regeneration, ameliorates experimental autoimmune encephalomyelitis (EAE), a commonly used animal model of MS. More efficient axonal regeneration was suggested as a mechanism underlying the improved EAE outcome. However, neutralization of Nogo also led to an anti-inflammatory shift of T cell cytokines during EAE suggesting that another therapeutic mechanism may involve regulation of immune cell responses. Here we report that human immune cells from healthy individuals and MS patients express Nogo receptor1 (NgR1) indicating that they may be subject to regulation by MAIs. B cells, T cells and monocytes express NgR1 in a regulated fashion upon activation. While direct stimulation of human immune cells with an inhibitory fragment of Nogo does not impact their in vitro proliferation or cytokine production, the immune cells display reduced adhesion and enhanced motility in response to myelin, effects that are in part attenuated by antagonizing NgR1 signaling. We conclude that NgR1 alters the motility of immune cells exposed to myelin and may thus impact their behaviour within the CNS, particularly under conditions when immune cell activation is heightened.
