Some recent trends in infant mortality in the province of Marrakech, Morocco: a demographic transition in process

2 studies designed to appraise fecundity and mortality were carried out in Morocco in 1983 and 1984, on samples of 3,000 and 5,000 women respectively, in the city and in the province of Marrakech. Infant mortality was studied using the biometric method of J. Bourgeois-Pichat. The 1st results presented in this article highlight the absence of excess exogenous mortality among women under 30 years of age living in a provincial urban environment and among women from the city of Marrakech whose husbands were employed in service activities. 1st, this points to a link between the level of exogenous mortality and the standard of living of the population. In the city, exogenous mortality varies according to the occupation of the head of the family, an important factor in estimating its economic level. In the province one can assume that the standard of living of women from urban areas is higher than in the country. Moreover, small urban centers benefit from a larger infrastructure with easier access to medical care. 2nd, mortality has declined among young women. This result is certainly closely linked to the improvement of living conditions in Morocco over the last 2 decades. It is therefore reasonable to consider that a demographic transition is taking place, one which impacts on the level and structure of infant mortality.     

Socioeconomic, demographic and environmental determinants of infant mortality in Nepal

The Nepal Fertility and Family Planning Survey of 1986 demonstrated that demographic variables, previous birth interval and survival of preceding child, still predominated as determinants of infant mortality, particularly in rural areas of Nepal. However, in urban Nepal, where the level of socioeconomic development is higher, an environmental variable, along with previous birth interval and survival of preceding child emerges as important in determining infant mortality. Separate policy measures for child survival prospects in rural and urban Nepal are suggested.     

Status competition,inequality, and fertility: implications for the demographic transition

The role that social status plays in small-scale societies suggests that status may be important for understanding the evolution of human fertility decisions, and for understanding how such decisions play out in modern contexts. This paper explores whether modelling competition for status—in the sense of relative rank within a society—can help shed light on fertility decline and the demographic transition. We develop a model of how levels of inequality and status competition affect optimal investment by parents in the embodied capital (health, strength, and skills) and social status of offspring, focusing on feedbacks between individual decisions and socio-ecological conditions. We find that conditions similar to those in demographic transition societies yield increased investment in both embodied capital and social status, generating substantial decreases in fertility, particularly under conditions of high inequality and intense status competition. We suggest that a complete explanation for both fertility variation in small-scale societies and modern fertility decline will take into account the effects of status competition and inequality.     

Recent trends in infant mortality rates and proportions of low-birth-weight live births in Canada

OBJECTIVE: To identify spatial patterns of changes in infant mortality rates and proportions of low-birth-weight live births observed in 1994. SETTING: Canada. SUBJECTS: Live births and infant deaths in Canada between 1987 and 1994. Data for Newfoundland were unavailable for 1987 through 1990. OUTCOME MEASURES: Annual infant mortality rates (crude and after excluding live newborns weighing less than 500 g); proportion of live births by low-birth-weight category (500-2499 g). RESULTS: Nova Scotia, New Brunswick, Quebec and Manitoba had lower crude and adjusted infant mortality rates in 1994 than in 1993. Newfoundland, Saskatchewan, Alberta and British Columbia had higher rates in 1994 than in 1993. The crude rate in Ontario was lower, and the adjusted rate higher, in 1994 than in 1993. A downward trend in the proportion of low-birth-weight live births was observed in Quebec (chi(2) for trend = 29.2, p < 0.01). Conversely, an upward trend was observed in Ontario (chi(2) for trend = 241.3, p < 0.01). However, the increase may have been due to data errors, especially in 1993 and 1994, involving truncation of ounces in 2 digits to 1 digit (e.g., 5 pounds 10 ounces became 5 pounds 1 ounce). CONCLUSIONS: Although the marginal increases in infant mortality observed in several provinces could be the result of random variation, future trends should be closely monitored. The proportion of low-birth-weight live births in Canada (excluding Ontario) appears to be stable, with Quebec showing significant reductions. The errors in data for Ontario need to be corrected before trends can be estimated for that province and for Canada as a whole.     

A Bayesian estimation approach for the mortality in a stage-structured demographic model

Journal of Mathematical Biology - Control interventions in sustainable pest management schemes are set according to the phenology and the population abundance of the pests. This information can be...     

Hosting the plant cells in vitro: recent trends in bioreactors

Biotechnological production of high-value metabolites and therapeutic proteins by plant in vitro systems has been considered as an attractive alternative of classical technologies. Numerous proof-of-concept studies have illustrated the feasibility of scaling up plant in vitro system-based processes while keeping their biosynthetic potential. Moreover, several commercial processes have been established so far. Though the progress on the field is still limited, in the recent years several bioreactor configurations has been developed (e.g., so-called single-use bioreactors) and successfully adapted for growing plant cells in vitro. This review highlights recent progress and limitations in the bioreactors for plant cells and outlines future perspectives for wider industrialization of plant in vitro systems as “green cell factories” for sustainable production of value-added molecules.     

Historical and recent changes in the Spanish forests: A socio-economic process

The evolution of Spanish landscapes through history is mainly a story of deforestation. Through time, exploitation of natural resources increased to cope with the requirements of more and more complex civilizations. In this work, a review of how the Spanish forests were influenced by human activities and their changes is provided. Forests were cleared for mining, charcoal, shipbuilding and caulking. The most fertile lands were converted into cultivation and more productive cultivars were introduced. Mobile livestock, in particular sheep, became widespread, and with it the burning of wooded land to produce pastures. Woods were privatized through a series of disentailments. All these factors have occurred during the history of Spain, linked to profound changes in the landscape and vegetation. Not until the beginning of the 20th century were real efforts devoted to invert the trend to deforestation inherited from the negative woodland management of previous centuries.     

A branching process, its application in biology: influence of demographic parameters on the social structure in mammal groups

Branching processes are widely used in biology. This theoretical tool is used in cell dynamics, epidemics and population dynamics. In population dynamics, branching processes are mainly used to access extinction probabilities of populations, groups or families, with the Galton-Watson branching process. Many mammal species live in socially-structured groups, and the smallest units of these groups are lineages (or families) of kin-related individuals. In many primate species, these lineages are matrilines, as females remain in their natal groups most of the time, whereas males generally disperse. Lineage parameters, such as numbers of matrilines, size of each matriline and average degree of relatedness, could strongly influence the genetic composition of groups. Evidence indicates that division along matrilines could induce substantial differentiation among fission groups. Here, we develop a novel mathematical model based on the branching process theory describing demographic dynamics of groups. The main result of this model is an explicit analytical expression of the joint distribution of numbers of lineages and sizes of socially-structured groups. We investigated the influence of parameters such as natality and mortality on the outcome of the process, including extinction probability. Finally, we discuss this theoretical result with respect to biological significance.     

Social and demographic effects of anthropogenic mortality: a test of the compensatory mortality hypothesis in the red wolf

Whether anthropogenic mortality is additive or compensatory to natural mortality in animal populations has long been a question of theoretical and practical importance. Theoretically, under density-dependent conditions populations compensate for anthropogenic mortality through decreases in natural mortality and/or increases in productivity, but recent studies of large carnivores suggest that anthropogenic mortality can be fully additive to natural mortality and thereby constrain annual survival and population growth rate. Nevertheless, mechanisms underlying either compensatory or additive effects continue to be poorly understood. Using long-term data on a reintroduced population of the red wolf, we tested for evidence of additive vs. compensatory effects of anthropogenic mortality on annual survival and population growth rates, and the preservation and reproductive success of breeding pairs. We found that anthropogenic mortality had a strong additive effect on annual survival and population growth rate at low population density, though there was evidence for compensation in population growth at high density. When involving the death of a breeder, anthropogenic mortality was also additive to natural rates of breeding pair dissolution, resulting in a net decrease in the annual preservation of existing breeding pairs. However, though the disbanding of a pack following death of a breeder resulted in fewer recruits per litter relative to stable packs, there was no relationship between natural rates of pair dissolution and population growth rate at either high or low density. Thus we propose that short-term additive effects of anthropogenic mortality on population growth in the red wolf population at low density were primarily a result of direct mortality of adults rather than indirect socially-mediated effects resulting in reduced recruitment. Finally, we also demonstrate that per capita recruitment and the proportion of adults that became reproductive declined steeply with increasing population density, suggesting that there is potential for density-dependent compensation of anthropogenically-mediated population regulation.     

Recent trends in neonatal mortality: the Canadian experience.

In Canada between 1958 and 1977 the neonatal mortality dropped by more than 50%. the decline was most prominent from 1963 and was almost entirely due to an improvement in neonatal birthweight-specific mortality, which suggests an improvement in perinatal medical care. The timing and pattern of the decline are similar to those reported for the United States. There was a transient increase in the incidence of low and very low birthweight in both countries in the late 1960s. The cause of this increase remains unexplained.     

Estimating mortality in skeletal populations: influence of the growth rate on the interpretation of levels and trends during the transition to agriculture

Traditional paleodemographic methods of estimating mortality have been based on unrealistic assumptions about the prevalence of closed and stationary populations. When a living closed population was growing, the mean age at death of its skeletal survivors will be shifted below its true life expectancy. For declining populations, the mean age at death will be higher than true underlying life expectancy at birth. The faster the rate of growth, the larger and more curvilinear is the displacement. Mortality estimates can only be extracted from skeletal populations via an independent estimate of the growth rate. Fertility levels, however, can be estimated directly. The empirical importance of growth rate-dependent mortality estimates is demonstrated by reinterpreting mean-age-at-death data from several populations before and after the agricultural revolution; with detailed consideration given to the Old World populations of Acsadi and Nemeskeri and a New World population from central Illinois.     

A population biological approach to the collective dynamics of countries undergoing demographic transition

Birth rates have been declining in higher-income countries since the middle of the 19th century. A growing number of other countries have entered this demographic transition to lower fertility, as socioeconomic development continues. Analyses of this demographic transition vary widely, but most analyze individual populations in isolation from others, and most come from fields outside the biological sciences. Here, we develop a population biological model of population dynamics in higher-income countries. Individual countries evolve through density-regulated growth, where gradual evolution toward higher population densities boosts productivity (and hence socioeconomic growth) through economics of agglomeration and scale, in turn reducing birth rates. The exchange of technology and capital between countries can further boost productivity gains in any given country, thus contributing to its demographic transition. As a result, countries can down-regulate one another's population growth through mutual improvements in productivity. The model is fitted to time series data on population size, GDP per capita, and birth rates for the United States, the United Kingdom, and France. The metapopulation dynamics are also characterized across a range of parameter values close to the fitted values. This work may help advance population biological approaches to understanding the implications of the fertility demographic transition for modern human populations. This is relevant to developing long-term predictions of the earth's total population size, which must be based upon a model that incorporates underlying mechanisms.     

Dynamics of the genetic demographic structure of the Kursk province population: migration processes

Marriage records from parish books of the second half of the 19th century and marriage records of 1967-1970 and 1993-1995 obtained from registry offices were used to analyze the dynamics of genetically significant parameters of migration and marriage structure with respect to spouses' birthplaces in populations of different hierarchical levels in the Kursk oblast. It was found that, among the persons contracting marriage (both males and females), the proportions of those who were born in the same population and those who were born in any population of the Kursk oblast decreased by about one third and one fifth, respectively, for the 130-year period. In rural and small urban populations, the coefficients of marriage migration in the 19th century were an order of magnitude lower than in the 20th century. The immigration to urban populations was maximum in the late 1960s (m = 0.745 in small towns and m = 0.680 in Kursk), and that to rural populations, in the 1990s (m = 0.344). In both urban and rural populations, the mean distance between the spouses' birthplaces has increased by several times for the period studied. The endogamy level has decreased approximately twofold: from 0.797 to 0.380 in Kursk, from 0.897 to 0.419 in small towns, and from 0.958 to 0.440 in rural districts. The marriage assortativeness with respect to birthplace was maximum in the late 19th century (K = 0.393-0.491) and minimum in the 1960s (K = 0.155-0.246). The increase in genetic diversity of the urban population of the Kursk oblast due to migration has been slowing down since the late 20th century, whereas the outbreeding level is still increasing in rural populations.     

Polar lipids in cosmetics: recent trends in extraction,separation, analysis and main applications

Demand for active, natural, safe and biomimetic (similar to human molecules) plantderived cosmetic ingredients is always greater because consumers are increasingly suspicious of the potential toxicity of current ingredients. In this context, interest has increased for polar lipids like ceramides, sphingolipids or glycolipids that share structural properties with the skin lipids. In the same manner, processes to obtain such lipids should be driven by the principles of green chemistry and sustainable development. The identified needs are biodegradability, biocompatibility, efficiency, quality and profitability. In this research for new and novel natural or ‘green’ compounds, the development of bioactive lipids thanks to ecofriendly processes has obviously intensified, especially for cosmetic and agro-food industries. This paper reviews extraction methods for polar lipids (glycolipids and phospholipids), especially ecoprocesses (supercritical fluid extraction, microwaves, sonication, enzyme extraction…), and promising chromatographic methods like countercurrent chromatography, supercritical fluid chromatography or high performance chromatography coupled to mass spectrometry Interests of polar lipids for cosmetic industries are exemplified to show their broad applications mostly relying on their amphiphilic properties allowing them to play functional roles (liposome or micelle structures for example) or physiological roles (skin barrier function or anti-ageing effect).