Son preference in Bangladesh: an emerging barrier to fertility regulation

This study investigates the effect of son preference on contraceptive use and desire for additional children using national level survey data from Bangladesh for the years 1969 and 1979. National probability samples of ever married women between the ages of 10 and 50 were selected and stratified by urban-rural residence. Specifically, the study focuses on contraceptive use and desire for additional children and separates the effect of sex preference from that of high parity on fertility control. Son preference has a negative effect on contraceptive use and a positive effect on the desire for additional children regardless of socioeconomic and demographic characteristics. This advese effect of son preference on fertility regulation seemed to have persisted over the years. Relevent socioeconomic conditions in Bangladesh are described. In 1979, the effect of sex composition on contraceptive use or desire for additional children varied by parity. The negative effect of fewer living sons on contraceptive use and its positive effect on desire for additional children was higher in parities between 2 and 4 than in other parities. The effect of sex composition was stronger on desire for additional children than on contraceptive usage. In 1969, however, there was no consistent positive relationship between sex composition and contraceptive use. The relationship between sex composition and desire for more children was positive. Among women of parities 2 to 4, an excess of daughters continued to have a major positive effect on desire for additional children, and a negative effect on contraceptive use, after controlling for other sociodemographic variables. For parities 1 and 5 or above, the effect was either weak or inconsistent.     

A test of the child replacement hypothesis: nineteenth century Massachusetts

Child mortality experiences may affect subsequent fertility of couples by exerting a physiological effect, influencing length of birth, interval, or a replacement effect, in which couples continue to procreate in an attempt to reach a desired number of surviving offspring. Where biological constraints are potentially important, however, it may be difficult to distinguish between purely physiological and purely behavioral components of the process regulating production. Natural spacing of births and onset of sterility may be affected by health and diet and prior childbearing and breastfeeding practices. Biological pressures can, in turn, be infuenced behaviorally both by social custom and individual choice. Studies of 126 families in 19th century Massachusetts show that reduction in infant mortality is not a prerequisite for onset of family limitation. Results for the study population did not exhibit a relationship between parity progression ratios and the experience of child mortality, consisten with the child replacement hypothesis. 1 factor involved may be the parent's expectations of more than the desired number of children because of imperfect contraceptive technology at the time. Preference for the sex of children also may weaken overall replacement effect, since the death of a child of "undesired" sex will not be replaced. The cohort age-specific fertility patterns indicate that a reduction in overall fertility level in the communities studied was parity-dependent and directed at stopping childbearing at some given range of family size. At any rate, parents are not passive participants in a natural regime of births and deaths. While child replacement may be present in some societies, it is relatively inefficient and perhaps infrequent.     

Son preference and fertility in China

This paper examines the effect of son preference on the hazards of having a second and a third birth. With data from the Two-per-thousand National Sample Survey on Fertility and Contraception conducted in 1988 by the State Family Planning Commission of China, the hazard of having a second birth among 62+ thousand married women who have had a first birth, and the hazard of having a third birth among 43+ thousand married women who have had two births was examined. These two hazards (i.e. the hazard of moving from the first to the second birth, and the hazard of moving from the second to the third birth) were analysed by estimating Cox proportional hazard models. The major covariate in the first analysis is whether or not the first-born was a daughter. In the second analysis the main covariate is whether both of the first two children were girls. In both models seven covariates known to have independent effects on the transition to a second (or third) birth are controlled for, namely, whether the woman is a Han, whether she is a farmer, her age at the birth of the first (or second) child, whether she had her first (or second) birth prior to the initiation in 1979 of the one-child policy, and three dummy variables reflecting her level of education. The results show the important influence of son preference on the hazard of having another birth.     

A critical look at the embodied cognition hypothesis and a new proposal for grounding conceptual content.

Many studies have demonstrated that the sensory and motor systems are activated during conceptual processing. Such results have been interpreted as indicating that concepts, and important aspects of cognition more broadly, are embodied. That conclusion does not follow from the empirical evidence. The reason why is that the empirical evidence can equally be accommodated by a 'disembodied' view of conceptual representation that makes explicit assumptions about spreading activation between the conceptual and sensory and motor systems. At the same time, the strong form of the embodied cognition hypothesis is at variance with currently available neuropsychological evidence. We suggest a middle ground between the embodied and disembodied cognition hypotheses--grounding by interaction. This hypothesis combines the view that concepts are, at some level, 'abstract' and 'symbolic', with the idea that sensory and motor information may 'instantiate' online conceptual processing.     

Son preference and the sex ratio at birth in China: A provincial level analysis

Abstract

Data from a Samoan menstruation study suggest that lactation, even intensive on‐demand lactation, does not inhibit menstruation or conception. This paper explores the applied and theoretical implications of continuing to accept lactation as a universally effective fertility control mechanism. Such thinking can have disastrous implications for family planning programs, and it keeps us from challenging long‐held assumptions about lactation's role in population growth in early populations.     

A second look at the second messenger hypothesis

Several hundred hormones, neurotransmitters, growth factors and other "first messengers" bind to specific cell membrane receptors and induce a myriad of effects: short term, transport, metabolic, mitotic and regulation of thousands of specific genes. Yet, less than a dozen "second messengers" have been clearly established to date. Even allowing for the discovery of a large number of additional second messengers, there remains a paradox in terms of information-transfer within the cell: how can so many specific signals produce so many effects through so few relatively nonspecific intermediates? We consider several possible solutions to this paradox, including the hypothesis that signal specificity is encoded in part in the primary structure of the receptor.     

Native-DIGE: a new look at the mitochondrial membrane proteome

Respiratory chain proteins play a pivotal role in mitochondrial metabolism and thereby in the aging process. Differential display of the mitochondrial proteome reveals the abundance changes occurring in proteins as response to complex events such as senescence and aging. However, there is an absolute need to implement a detection technique that could potentially encompass the hydrophobic and very basic membrane proteins, along with the soluble ones. It is also important to assess protein-protein interactions, besides changes in abundance. Native-difference gel electrophoresis (DIGE) is an approach that facilitates sensitive quantitative assessment of changes in membrane and soluble proteins. It stretches the boundaries of detecting abundance changes to protein-protein interactions for interpretation of a proteome in a more "meaningful" way. Here we evaluate the benefits of blue-native fluorescence DIGE as a method in differential quantitative proteomics with a focus on critical issues for application and experimental design.     

Physician assisted suicide: a new look at the arguments

In this paper, I examine the argumens agains physician assisted suicide (PAS). Many of these arguments are consequentialist. Consequentialist arguments rely on empirical claims about the future and thus their strength depends on how likely it is that the predictions will be realized. I discuss these predictions against the backdrop of Oregon's Death with Dignity Act and the practice of PAS in the Netherlands. I then turn to a specific consequentialist argument against PAS - Susan M. Wolfs feminist critique of the practice. Finally, I examine the two most prominent deontological arguments against PAS. Ultimately, I conclude that no anti-PAS argument has merit. Although I do not provide positive arguments for PAS, if none of the arguments against it are strong, we have no reason not to legalize it.     

Effect of child survival on contraceptive use in Bangladesh.

A study in Bangladesh showed that couples who lost a child often stopped practising contraception in order to have another child. Logistic regression analysis revealed that contraceptive continuation was related to maternal age, parity, husband's education and the sex of the last child.     

Breast feeding,nutritional state,and child survival in rural Bangladesh

The effect of breast feeding on nutritional state, morbidity, and child survival was examined prospectively in a community in rural Bangladesh. Every month for six months health workers inquired about breast feeding and illness and measured arm circumference in an average of 4612 children aged 12-36 months. Data from children who died within one month of a visit were compared with those from children who survived. Roughly one third of the deaths in the age range 18-36 months were attributable to absence of breast feeding. Within this age range protection conferred by breast feeding was independent of age but was evident only in severely malnourished children.In communities with a high prevalence of malnutrition breast feeding may substantially enhance child survival up to 3 years of age.     

Fireflies at one hundred plus: a new look at flash control

The mysterious process by which fireflies can control theirflashing has inspired over a century of careful observationbut has remained elusive. Many studies have implicated oxygenas the controlling element in the photochemical reaction, andthe discovery of nitric oxide synthetase (NOS) in the lanternhas suggested that nitric oxide (NO) may control oxygen accessto the light-emitting photocytes, thereby triggering the flash.However, there are several drawbacks to oxygen as a controllingagent, and in view of the prominence of peroxisomes in lanternmorphology and biochemistry, we suggest that it is hydrogenperoxide that triggers the flash, and we present a model bywhich this may take place.     

Myxosporea: a new look at long-known parasites of fish

With the identification of Myxosporea as agents of swimbladder inflammation (SBI) in carp, and proliferative kidney disease (PKD) in salmonids, this group of over 1000 protistan species has been receiving renewed attention. Almost all species are parasites offish, and some can cause serious losses in commercial fish farms. Yet adequate control measures cannot be planned without clarification of basic features of the parasites' life cycles and modes of transmission. In this article, Jiri Lom reviews progress in understanding these biological puzzles.     

Cephalosporanic acids: a new look at reactions at the C-3' position

Nucleophilic displacement of the acetoxy group of cephalosporanic acids by thiols in aqueous solution at neutral pH provides 3-thiomethyl-substituted compounds with a broad spectrum of antibiotic activity. The aqueous displacement reaction is often destructive of much of the cephalosporanic acid, and products generally require extensive purification. Displacements at a lower pH are complicated by unwanted lactone formation. However, reactions conducted under acid conditions in a variety of anhydrous organic solvents give 3-thiomethyl-substituted compounds in very high yield and quality; no lactone formation is observed. The kinetics of the reaction support an SN1 mechanism. Protonation of the departing acetoxy group appears therefore critical; the more basic solvents, e.g. dimethylsulphoxide and N,N-dimethylformamide, significantly retard the rate of reaction.