Purification of Acetylcholine-Receptor Enriched Membranes by Use of Affinity Partitioning

Membrane fragments rich in acetylcholine receptor from the electric organ of Torpedo caLifornica were purified by a combination of classical methods and affinity partitioning, a method analogous to affinity chromatography. Affinity partitioning is based upon the phase partition method where two water-rich liquid phases are formed upon the addition of sufficient quantities of water soluble polymers such as poly(ethylene oxide) and dextran. A phase system in which less than 2°/o of acetylcholinesterase, adenosine triphosphatase and a-toxin binding activities di,s,tribute ilnto the poly(ethylene oxide) rich phase was chosen. By adding cholinergic derivatives of poly(ethylene oxide), selective changes in the distribution of membrane fragments rich in acetylcholine receptor into the poly(ethylene oxide) rich were achieved. Sodium dodecyl sulfate polyacrylamide gel electrophoresis as well as assay of cobra a-toxin binding, acetylcholinesterase and adenosinetriphosphatase activities indicate that substantial purification of membrane- bound acetylcholine receptor was achieved

Ecophysiological traits of grasses: resolving the effects of photosynthetic pathway and phylogeny

C4 photosynthesis is an important example of convergent evolution in plants, having arisen in eudicots, monocots and diatoms. Comparisons between such diverse groups are confounded by phylogenetic and ecological differences, so that only broad generalisations can be made about the role of C4 photosynthesis in
determining ecophysiological traits. However, 60% of C4 species occur in the grasses (Poaceae) and molecular phylogenetic techniques confirm that there are between 8 and 17 independent origins of C4 photosynthesis in the Poaceae. In a screening experiment, we compared leaf physiology and growth traits across several major
independent C3 & C4 groups within the Poaceae, asking 1) which traits differ consistently between photosynthetic
types and 2) which traits differ consistently between clades within each photosynthetic type

Financial Anxiety in Low- and Moderate-Income Households: Findings From the Household Financial Survey

Despite significant gains in the U.S. economy following the Great Recession, finances remain a common source of stress for many American households. In 2016, 52% of U.S. workers reported that their financial position made them stressed, and research reveals that stress and anxiety associated with finances are particularly common among low-income Americans. In this brief, we explore the topic of financial anxiety, particularly its relationship to demographic and financial characteristics, measures of hardship, and financial behaviors. We find that financial anxiety is strongly linked to the overall levels of debt and assets held by low-income households, as well as their ability to access resources in an emergency, but is not closely linked with income measures. Households incapable of saving due to their expenses and those experiencing material hardships also have higher levels of financial anxiety. Policymakers and program designers could help address this issue in several ways. For example, they might work to expand access to programs intended to provide financial slack to low-income households; assistance in building emergency savings and access to low-cost credit products would improve slack in these households while improving protection against income and expense volatility and its associated stresses

Do pollinators contribute to nutritional health?

Despite suggestions that animal pollinators are crucial for human nutritional health, no studies have actually tested this claim. Here, we combined data on crop pollination requirements, food nutrient densities, and actual human diets to predict the effects of pollinator losses on the risk of nutrient deficiency. In four developing countries and across five nutrients, we found that 0 to 56% of populations would become newly at risk if pollinators were removed. Increases in risk were most pronounced for vitamin A in populations with moderate levels of total nutrient intake. Overall, the effects of pollinator decline varied widely among populations and nutrients. We conclude that the importance of pollinators to human nutrition depends critically on the composition of local diets, and cannot be reliably predicted from global commodity analyses. We identify conditions under which severe health effects of pollinator loss are most likely to occur

The State of State EITCs: An Overview and Their Implications for Low- and Moderate-Income Households

The success of the federal Earned Income Tax Credit (EITC) has prompted numerous states to develop and administer their own EITC programs. This brief presents the results of analyses that used data from a large sample of low- and moderate-income households to learn more about the relationship between state and federal EITCs as well as about their relationships, respective and combined, with financial behaviors and the experience of financial and material hardship. Given that many EITC beneficiaries face substantial risk of experiencing income volatility and financial shocks, insights gained from this brief can assist policymakers in understanding the importance of expanded EITCs and promoting emergency saving at tax time

Low temperature solvent-free allylic oxidation of cyclohexene using graphitic oxide catalysts

A range of graphitic oxides have been utilised as metal free carbocatalysts for the low temperature oxidation of cyclohexene. The activity of the catalysts was correlated with the amount of surface oxygen on the graphitic oxide. In the case of cyclohexene oxidation, major selectivity is observed to allylic oxidation products. This is in contrast to the epoxide being the major product in linear alkene oxidation. This selectivity was maintained over long reaction times and at a conversion of above 50 %. Only small amounts of epoxide were observed, which eventually decreases at higher conversion due to hydrolysis to cyclohexane diol. The similarity between the non-catalysed and the catalysed product distribution suggests that these catalysts act as a solid initiator, and the role of the graphitic oxide is to decrease the lengthy induction period observed in the blank non-catalysed reaction

The Burden of Student Debt: Findings From a Survey of Low- and Moderate-Income Households

Completing a college degree continues to offer a pathway for enjoying greater earnings. Yet tuition has risen sharply and state higher-education funding has declined in recent years, shifting the burden of paying for college to students and their families. As a result, most students (70%) depend on loans to help pay for college and student debt is now greater than credit card debt in the United States. Student debt is increasingly difficult to manage, as debt-to-income ratios, loan default rates, and delinquency rates are on the rise. This brief utilizes data from the 2014 Refund to Savings study to examine the experiences of low- and moderate-income (LMI) tax filers with student debt. The findings show that over half (51%) of the sample (N = 8,772) had student debt. Borrowers owed $35,482, on average, and were more likely than nonborrowers to experience financial difficulties, such as overdrawing bank accounts, and hardships, such as skipping a housing payment. Compared with borrowers from other racial/ethnic groups, Black borrowers were more likely to experience difficulty repaying their student loans. Policies should aim to decrease the proportion of college costs that is financed by student loans, provide additional support to students from LMI households, and address racial disparities in education

Bounding the graviton mass with binary pulsar observations

By comparing the observed orbital decay of the binary pulsars PSRB1913+16 and PSRB1534+12 to that predicted by general relativity due to gravitational-wave emission, we are able to bound the mass of the graviton to be less than $7.6\times10^{-20} \text{eV}/c^2$ at 90% confidence. This is the first such bound to be derived from dynamic gravitational fields. It is approximately two orders of magnitude weaker than the static-field bound from solar system observations, and will improve with further observations.Comment: 9 pages, 1 figure. Presented at Fourth Edoardo Amaldi Conference on Gravitational Waves, Perth, 200

Racial Disparities in Student Debt: Evidence From the Refund to Savings Initiative

This brief provides evidence that low- and moderate-income (LMI) Black households accumulate significantly more debt in pursuit of a higher education than do LMI White students, even after using rigorous methods to account for race- and debt-related confounders. Using data from the Refund to Savings experiment, the authors find that LMI Black households accrued $7,721 more in student loan debt than their White counterparts did. This finding is crucial in light of the financial vulnerability of this population both before and after college. That vulnerability potentially contributes to diminished returns and exacerbates racial disparities in educational outcomes and wealth accumulation. The brief discusses policy remedies that can continue to enhance access to college for low-income minorities while ensuring equitable outcomes during and after college

Purification of Acetylcholine-Receptor Enriched Membranes by Use of Affinity Partitioning

Membrane fragments rich in acetylcholine receptor from the electric organ of Torpedo caLifornica were purified by a combination of classical methods and affinity partitioning, a method analogous to affinity chromatography. Affinity partitioning is based upon the phase partition method where two water-rich liquid phases are formed upon the addition of sufficient quantities of water soluble polymers such as poly(ethylene oxide) and dextran. A phase system in which less than 2°/o of acetylcholinesterase, adenosine triphosphatase and a-toxin binding activities di,s,tribute ilnto the poly(ethylene oxide) rich phase was chosen. By adding cholinergic derivatives of poly(ethylene oxide), selective changes in the distribution of membrane fragments rich in acetylcholine receptor into the poly(ethylene oxide) rich were achieved. Sodium dodecyl sulfate polyacrylamide gel electrophoresis as well as assay of cobra a-toxin binding, acetylcholinesterase and adenosinetriphosphatase activities indicate that substantial purification of membrane- bound acetylcholine receptor was achieved