SPG20 Protein Spartin Associates with Cardiolipin via Its Plant-Related Senescence Domain and Regulates Mitochondrial Ca2+ Homeostasis

Hereditary spastic paraplegias (HSPs) are a group of neurological disorders characterized clinically by spasticity of lower limbs and pathologically by degeneration of the corticospinal tract. Troyer syndrome is an autosomal recessive HSP caused by a frameshift mutation in the spartin (SPG20) gene. Previously, we established that this mutation results in a lack of expression of the truncated mutant spartin protein. Spartin is involved in many cellular processes and associates with several intracellular organelles, including mitochondria. Spartin contains a conserved plant-related senescence domain at its C-terminus. However, neither the function of this domain nor the roles of spartin in mitochondrial physiology are currently known. In this study, we determined that the plant-related senescence domain of spartin interacts with cardiolipin but not with two other major mitochondrial phospholipids, phosphatidylcholine and phosphatidylethanolamine. We also found that knockdown of spartin by small interfering RNA in a human neuroblastoma cell line resulted in depolarization of the mitochondrial membrane. In addition, depletion of spartin resulted in a significant decrease in both mitochondrial calcium uptake and mitochondrial membrane potential in cells treated with thapsigargin. Our results suggest that impairment of mitochondrial calcium uptake might contribute to the neurodegeneration of long corticospinal axons and the pathophysiology of Troyer syndrome

Historical Missionary Activity, Schooling, and the Reversal of Fortunes: Evidence from Nigeria

This paper shows that historical missionary activity has had a persistent effect on schooling outcomes, and contributed to a reversal of fortunes wherein historically richer ethnic groups are poorer today. Combining contemporary individual-level data with a newly constructed dataset on mission stations in Nigeria, we find that individuals whose ancestors were exposed to greater missionary activity have higher levels of schooling. This effect is robust to omitted heterogeneity, ethnicity fixed effects, and reverse causation. We find inter-generational factors and the persistence of early advantages in educational infrastructure to be key channels through which the effect has persisted. Consistent with theory, the effect of missions on current schooling is larger for population subgroups that have historically suffered disadvantages in access to education

Private Wage Returns To Schooling In Nigeria: 1996-1999

In the last two decades, primary and secondary school enrollment rates have declined in Nigeria while enrollment rates in post-secondary school have increased. This paper estimates from the General Household Survey for Nigeria the private returns to schooling associated with levels of educational attainment for wage and self-employed workers. The estimates for both men and women are small at primary and secondary levels, 2 to 4 percent, but are substantial at post-secondary education level, 10-15 percent. These schooling return estimates may account for the recent trends in enrollments. Thus, increasing public investment to encourage increased attendance in basic education is not justifiable on grounds of private efficiency, unless investments to increase school quality have higher private returns. With high private returns to postsecondary schooling, students at this level should pay tuition, to recoup more of the public costs of schooling, which may be redistributed to poor families through scholarships. Key words: Schooling Investment; Private Wage Returns; Efficiency; Equity; Nigeria JEL Classifications: O15, I12, J24 1

Socioeconomic factors affecting insecticide use in cowpea production in Kano State

Insecticide is an indispensable input in cowpea production and farmers do not, in most cases, use the recommended dilution and application rates to mix insecticide and these reduce potency of such insecticide. It is against this milieu that this study was carried out to determine the socioeconomic factors affecting insecticide use in cowpea production, using Kano state as the study area. Cross sectional data were collected from two of the three zones in the study area and two blocks in each zone. A total of 100 respondents were interviewed through a simple random. sampling procedure. Data collected were analysed using descriptive statistics and OLS regression estimates. The study found out among others that the average age of cowpea farmers sampled was 44 years, all males, married with an average of 12 persons per household. The average farm size cultivated was 3.54 ha under an intercrop anangement with insecticide use at an average of three times per growing season. The socioeconomic factors affecting insecticide use was determined to be price of insecticide ( DC o.os), cowpea output ( oc o.os), farming experience ( DC o. 10), and formal edU;cation level ( DC 0.10); thus indicating the importance of these variables to cowpea production in the study area. The study recommended among others a price reduction policy to allow easy access of farmers to this input

Deficit of Resolution Receptor Magnifies Inflammatory Leukocyte directed Cardiorenal and Endothelial Dysfunction with Signs of Cardiomyopathy of Obesity

Chronic unresolved inflammation is the primary determinant of cardiovascular disease. Precise mechanisms that define the genesis of unresolved inflammation in heart failure with preserved ejection fraction (HFpEF) are of interest due to the obesity epidemic. To examine the obesity phenotype and its direct/indirect consequences, multiple approaches were employed using the lipoxin receptor (abbreviated as ALX) dysfunction mouse model. Indirect calorimetry analyses revealed that the deletion of ALX dysregulated energy metabolism driving toward age‐related obesity. Heart function data suggest that obesity‐prone ALX deficient mice had impaired myocardium strain. Comprehensive measurement of chemokines, extracellular matrix, and arrhythmogenic arrays confirmed the dysregulation of multiple ion channels gene expression with amplified inflammatory chemokines and cytokines response at the age of 4 months compared with WT counterparts. Quantitative analyses of leukocytes demonstrated an increase of proinflammatory Ly6ChiCCR2+ macrophages in the spleen and heart at a steady‐state resulting in an inflamed splenocardiac axis. Signs of subtle inflammation were marked with cardiorenal, endothelial defects with decreased CD31 and eNOS and an increased iNOS and COX2 expression. Thus, ALX receptor deficiency serves as an experimental model that defines multiple cellular and molecular mechanisms in HFpEF that could be a target for the development of HFpEF therapy in cardiovascular medicine