Matriliny as daughter-biased investment

From an evolutionary perspective, matriliny presents a puzzle because men in matrilineal societies transmit wealth to their sisters' sons, to whom they are only half as related as to their own sons. It has been argued that such systems would only maximise fitness under unrealistically high levels of paternity uncertainty. In this paper, we propose that matriliny can arise from daughter-biased investment by parents and/or grandparents. We show that daughter-biased investment is adaptive if the marginal benefit of wealth to sons (compared to daughters) does not outweigh the risk of nonpaternity in sons' offspring. We argue that such conditions will be rare where resource-holding polygyny is prevalent but could otherwise be widespread under even moderate levels of paternity uncertainty. The daughter-biased investment model explains two well-known characteristics of matrilineal descent: (a) matriliny's association with high levels of paternity uncertainty and (b) matriliny's ecological correlates, including its association with horticulture, its rarity in pastoralist and agro-pastoralist societies, and the tendency for matriliny to be replaced by sonbiased inheritance during economic development. We present data on wealth, sex, and reproductive success (RS) in two African societies, the matrilineal Chewa in Malawi and patrilineal Gabbra in Kenya, which support the daughter-biased investment theory. © 2003 Elsevier Science Inc. All rights reserved

Stabilizing stainless steel components for cryogenic service

Warpage and creep in stainless steel valve components are decreased by a procedure in which components are machined to a semifinish and then cold soaked in a bath of cryogenic liquid. After the treatment they are returned to ambient temperature and machine finished to the final drawing dimensions

High-pressure seals for rotary shafts

High pressure seals for rotating shafts are machined from a polyimide resin. It is more durable and cheaper than the older seals of plastic coated metal and works at temperatures between - 400 degrees and plus 900 degrees f

Phylogenetic analysis of the evolution of lactose digestion in adults

In most of the world's population the ability to digest lactose declines sharply after infancy, High lactose digestion capacity in adults is common only in populations of European and circum-Mediterranean origin and is thought to be an evolutionary adaptation to millennia of drinking milk from domestic livestock, Milk can also be consumed in a processed form, such as cheese or soured milk, which has a reduced lactose content, Two other selective pressures for drinking fresh milk with a high lactose content have been proposed: promotion of calcium uptake in high-latitude populations prone to vitamin-D deficiency and maintainance of water and electrolytes in the body in highly arid environments, These three hypotheses are all supported by the geographic distribution of high lactose digestion capacity in adults. However, the relationships between environmental variables and adult lactose digestion capacity are highly confounded by the shared ancestry of many populations whose lactose digestion capacity has been tested, The three hypotheses for the evolution of high adult lactose digestion capacity are tested here using a comparative method of analysis that takes the problem of phylogenetic confounding into account, This analysis supports the hypothesis that high adult lactose digestion capacity is an adaptation to dairying but does not support the hypotheses that lactose digestion capacity is additionally selected for either at high latitudes or in highly arid environments. Furthermore, methods using maximum likelihood are used to show that the evolution of milking preceded the evolution of high lactose digestion

The business-social policy nexus: Corporate power and corporate inputs into social policy

It is increasingly impossible to understand and explain the shape and delivery of contemporary social policy unless we consider the role of business. Several factors have been at work here. First, many of the changes in social policy introduced since the 1970s have been in response either to business demands or more general concerns about national competitiveness and the needs of business. Second, globalisation has increased corporate power within states, leading to transformations in social and fiscal policies. Third, business has been incorporated into the management of many areas of the welfare state by governments keen to control expenditure and introduce private sector values into services. Fourth, welfare services, from hospitals to schools, have been increasingly opened up to private markets. Despite all this, the issues of business influence and involvement in social policy has been neglected in the literature. This article seeks to place corporate power and influence centre-stage by outlining and critically reflecting on the place of business within contemporary welfare states, with a particular focus on the UK. Business, it argues, is increasingly important to welfare outcomes and needs to be taken into account more fully within the social policy literature

From bridewealth to dowry? A Bayesian estimation of ancestral states of marriage transfers in Indo-European groups

Significant amounts of wealth have been exchanged as part of marriage settlements throughout history. Although various models have been proposed for interpreting these practices, their development over time has not been investigated systematically. In this paper we use a Bayesian MCMC phylogenetic comparative approach to reconstruct the evolution of two forms of wealth transfers at marriage, dowry and bridewealth, for 51 Indo-European cultural groups. Results indicate that dowry is more likely to have been the ancestral practice, and that a minimum of four changes to bridewealth is necessary to explain the observed distribution of the two states across the cultural groups

Slicing of silicon into sheet material. Silicon sheet growth development for the large area silicon sheet task of the low cost silicon solar array project

Fabrication of a prototype large capacity multiple blade slurry saw is considered. Design of the bladehead which will tension up to 1000 blades, and cut a 45 cm long silicon ingot as large as 12 cm in diameter is given. The large blade tensioning force of 270,000 kg is applied through two bolts acting on a pair of scissor toggles, significantly reducing operator set-up time. Tests with an upside-down cutting technique resulted in 100% wafering yields and the highest wafer accuracy yet experienced with MS slicing. Variations in oil and abrasives resulted only in degraded slicing results. A technique of continuous abrasive slurry separation to remove silicon debris is described

A Note on Inflation Persistence

Macroeconomists have for some time been aware that the New Keynesian Phillips curve, though highly popular in the literature, cannot explain the persistence observed in actual inflation. We argue that two of the more prominent alternative formulations, the Fuhrer and Moore (1995) relative contracting model and the Blanchard and Katz (1999) reservation wage conjecture, are highly problematic. Fuhrer and Moore (1995)'s formulation generates inflation persistence, but this is a consequence of their assuming that workers care about the past real wages of other workers. Making the more reasonable assumption that workers care about the current real wages of other workers, one obtains the standard formulation with no inflation persistence. The Blanchard and Katz conjecture turns out to imply that inflation depends negatively on itself lagged, i.e. the opposite of the empirical regularity.

Coordination, Fair Treatment and Inflation Persistence

Most wage-contracting models with rational expectations fail to replicate the persistence in inflation observed in the data. We argue that coordination problems and multiple equilibria are the keys to explaining inflation persistence. We develop a wage-contracting model in which workers are concerned about being treated fairly. This model generates a continuum of equilibria (consistent with a range for the rate of unemployment), where workers want to match the wage set by other workers. If workers' expectations are based on the past behavior of wage growth, these beliefs will be self-fulfilling and thus rational. Based on quarterly U.S. data over the period 1955-2000, we find evidence that inflation is more persistent between unemployment rates of 4.7 and 6.5 percent, than outside these bounds, as predicted by our model.