Does Quality Time Produce Quality Children? Evidence on the Intergenerational Transmission of Human Capital Using Parental Deaths

This paper uses variation created by parental deaths in the amount of time children spend with each parent to examine whether the parent-child correlation in schooling outcomes stems from a causal relationship. Using a large sample of Israeli children who lost one parent during childhood, we find a series of striking patterns which show that the relationship is largely causal. Relative to children who did not lose a parent, the education of the deceased parent is less important in determining child outcomes, while the education of the surviving parent becomes a stronger factor. Moreover, within the group of families that lost a parent, this pattern intensifies when a child loses a parent earlier in life – the education of the deceased parent becomes even less important, while the effect of the surviving parent's schooling intensifies. These results provide strong evidence that there is a causal connection between parent and child schooling, which is dependent on the child's interaction time with each parent. These findings help us understand why educated parents typically spend more time with their children – they are more effective in producing human capital in their children.intergenerational mobility, education

Intracellular Regulatory Networks are close to Monotone Systems

Several meso-scale biological intracellular regulatory networks that have specified directionality of interactions have been recently assembled from experimental literature. Directed networks where links are characterized as positive or negative can be converted to systems of differential equations and analyzed as dynamical systems. Such analyses have shown that networks containing only sign-consistent loops, such as positive feed-forward and feedback loops function as monotone systems that display well-ordered behavior. Perturbations to monotone systems have unambiguous global effects and a predictability characteristic that confers advantages for robustness and adaptability. We find that three intracellular regulatory networks: bacterial and yeast transcriptional networks and a mammalian signaling network contain far more sign-consistent feedback and feed-forward loops than expected for shuffled networks. Inconsistent loops with negative links can be more easily removed from real regulatory networks as compared to shuffled networks. This topological feature in real networks emerges from the presence of hubs that are enriched for either negative or positive links, and is not due to a preference for double negative links in paths. These observations indicate that intracellular regulatory networks may be close to monotone systems and that this network topology contributes to the dynamic stability

THE MYSTERY OF MONOGAMY

This paper examines why developed countries are monogamous while rich men throughout history have tended to practice polygyny (multiple wives). Wealth inequality naturally produces multiple wives for rich men in a standard model of the marriage market. This paper argues that the sources of inequality, not just the level of inequality, determine the equilibrium degree of monogamy or polygamy. In particular, when inequality is determined more by disparities in human capital versus non-labor income (such as land, capital, corruption), the outcome is more monogamous. This explains why developed countries, where human capital is the main source of income and inequality, are monogamous while less-developed economies tend to be polygynous. The results are driven by the larger inequality in the value of women in the marriage market in modern economies. When the value of human capital increases, rich men increasingly value quality women who can help them raise quality children more efficiently. As a result, high quality women are valued much more than low quality women, which makes polygyny less affordable for rich men. In this manner, we show that male inequality generates polygyny, but female inequality reduces it. Using data from Cote d'Ivoire, we provide evidence for all the main implications of the model. In particular, we control for a man's total income and show that polygyny increases with non-labor income but decreases with labor income and education. These patterns are strong even within social groups where norms regarding polygyny are likely to be constant.Marriage, Monogamy, Polygyny, Human Capital, Inequality, J12, J24, O10, O40, Labor and Human Capital,

Crowdsourcing complex workflows under budget constraints

We consider the problem of task allocation in crowdsourcing systems with multiple complex workflows, each of which consists of a set of interdependent micro-tasks. We propose Budgeteer, an algorithm to solve this problem under a budget constraint. In particular, our algorithm first calculates an efficient way to allocate budget to each workflow. It then determines the number of inter-dependent micro-tasks and the price to pay for each task within each workflow, given the corresponding budget constraints. We empirically evaluate it on a well-known crowdsourcing-based text correction workflow using Amazon Mechanical Turk, and show that Budgeteer can achieve similar levels of accuracy to current benchmarks, but is on average 45% cheaper

Mechanism of Ivermectin Facilitation of Human P2X4 Receptor Channels

Ivermectin (IVM), a widely used antiparasitic agent in human and veterinary medicine, was recently shown to augment macroscopic currents through rat P2X4 receptor channels (Khakh, B.S., W.R. Proctor, T.V. Dunwiddie, C. Labarca, and H.A. Lester. 1999. J. Neurosci. 19:7289–7299.). In the present study, the effects of IVM on the human P2X4 (hP2X4) receptor channel stably transfected in HEK293 cells were investigated by recording membrane currents using the patch clamp technique. In whole-cell recordings, IVM (≤10 μM) applied from outside the cell (but not from inside) increased the maximum current activated by ATP, and slowed the rate of current deactivation. These two phenomena likely result from the binding of IVM to separate sites. A higher affinity site (EC50 0.25 μM) increased the maximal current activated by saturating concentrations of ATP without significantly changing the rate of current deactivation or the EC50 and Hill slope of the ATP concentration-response relationship. A lower affinity site (EC50 2 μM) slowed the rate of current deactivation, and increased the apparent affinity for ATP. In cell-attached patch recordings, P2X4 receptor channels exhibited complex kinetics, with multiple components in both the open and shut distributions. IVM (0.3 μM) increased the number of openings per burst, without significantly changing the mean open or mean shut time within a burst. At higher concentrations (1.5 μM) of IVM, two additional open time components of long duration were observed that gave rise to long-lasting bursts of channel activity. Together, the results suggest that the binding of IVM to the higher affinity site increases current amplitude by reducing channel desensitization, whereas the binding of IVM to the lower affinity site slows the deactivation of the current predominantly by stabilizing the open conformation of the channel

Strategies to Develop Food Crop Commodity to Improve the Prosperity of Rural Farmers in Gr0bogan District

The policy strategy to develop the agricultural sector in Indonesia is important to be arranged as agriculture has various problems and needs a comprehensive policy. Many districts in Central Java are dominated by agriculture sector where agricultural becomes the basis for the economy. The agricultural sector therefore provides significant contribution towards economic structure and commodities' production. In terms of commodity, corn is the second biggest agricultural commodity after paddy in Grobogan district in Central Java, reflected by a huge demand of corn in the market. The strategy to develop corn farming in Grobogan district therefore needs to be dealt with various criteria and alternatives. This study will consider several aspects which have an important role in agricultural sector as strategies to develop food crop particularly corn commodity to improve the farmers' prosperity in Grobogan

Lower Limits on Aperture Size for an ExoEarth-Detecting Coronagraphic Mission

The yield of Earth-like planets will likely be a primary science metric for future space-based missions that will drive telescope aperture size. Maximizing the exoEarth candidate yield is therefore critical to minimizing the required aperture. Here we describe a method for exoEarth candidate yield maximization that simultaneously optimizes, for the first time, the targets chosen for observation, the number of visits to each target, the delay time between visits, and the exposure time of every observation. This code calculates both the detection time and multi-wavelength spectral characterization time required for planets. We also refine the astrophysical assumptions used as inputs to these calculations, relying on published estimates of planetary occurrence rates as well as theoretical and observational constraints on terrestrial planet sizes and classical habitable zones. Given these astrophysical assumptions, optimistic telescope and instrument assumptions, and our new completeness code that produces the highest yields to date, we suggest lower limits on the aperture size required to detect and characterize a statistically-motivated sample of exoEarths.Comment: Accepted for publication in ApJ; 38 pages, 16 Figures, 3 Table

Zonisamide for migraine prophylaxis in refractory patients

Zonisamide, a new antiepileptic drug, has been approved in the US as adjunctive therapy for the treatment of partial seizures in adults.1,2 Chemically a sulfonamide analogue, zonisamide is thought to have several mechanisms of action, including a rate-dependent blockade of voltage-gated sodium channels and reduction of ion flow through T-type calcium channels.3-5 It is also a weak carbonic anhydrase inhibitor. Zonisamide has a favorable pharmacokinetic profile that includes high oral bioavailability and a long half life (63 hours), permitting a once- or twice-daily dosing regimen.6 There are only a limited number of current migraine preventive medications that have proven efficacy. Their use is often limited because of adverse events (AEs) in a significant number of patients.7 Because of its pharmacologic properties, zonisamide is potentially an effective drug for migraine prevention, and preliminary data suggest that it may be effective for this indication.8-10 The long half life of the drug makes it a good candidate for migraine patients who have poor compliance to preventive therapy that involves multiple daily dosing. The aim of this study was to evaluate the efficacy and tolerability of zonisamide for migraine prophylaxis in refractory patients attending a tertiary headache center