Multiregional periodic matrix for modeling the population dynamics of sardine (Sardina pilchardus) along the moroccan atlantic coast: management elements for fisheries.

In this paper, we present a deterministic time discrete mathematical model based on multiregional periodic matrices to describe the dynamics of Sardina pilchardus in the Central Atlantic area of the Moroccan coast. This model deals with two stages (immature and mature) and three spatial zones where sardines are supposed to migrate from one zone to another. The population dynamics is described by an autonomous recurrence equation N(t + 1) = A.N(t), where A is a positive matrix whose entries are estimated using data collected during biannual acoustic surveys carried out from 2001 to 2003 onboard the Norwegian research vessel "Dr Fridtjof Nansen". The dominant eigenvalue lambda of A that gives the long-term growth rate of fish population is smaller than one. This agrees with the stock decrease observed in the data collected. We show that lambda is highly sensitive to the recruitment rate and much less sensitive to the reproduction rate. These results can clearly be used to define an efficient scenario in order to fight for instance against a stock decrease.

Health indicators and human development in the Arab region.

BACKGROUND: The present paper deals with the relationship between health indicators and human development in the Arab region. Beyond descriptive analysis showing geographic similarities and disparities inter countries, the main purpose is to point out health deficiencies and to propose pragmatic strategies susceptible to improve health conditions and consequently enhance human development in the Arab world. METHODS: Data analysis using Principal Components Analysis is used to compare the achievements of the Arab countries in terms of direct and indirect health indicators. The variables (indicators) are seen to be well represented on the circle of correlation, allowing for interesting interpretation and analysis. The 19 countries are projected on the first and second plane respectively. RESULTS: The results given by the present analysis give a good panorama of the Arab countries with their geographic similarities and disparities. The high correlation between health indicators and human development is well illustrated and consequently, countries are classified by groups having similar human development. The analysis shows clearly how health deficits are impeding human development in the majority of Arab countries and allows us to formulate suggestions to improve health conditions and enhance human development in the Arab World. DISCUSSION: The discussion is based on the link between different direct and indirect health indicators and the relationship between these indicators and human development index. Without including the GDP indicator, our analysis has shown that the 19 Arab countries may be classified, independently of their geographic proximity, in three different groups according to their global human development level (Low, Medium and High). Consequently, while identifying health deficiencies in each group, the focus was made on the countries presenting a high potential of improvement in health indicators. In particular, maternal mortality and infant mortality which are really challenging health authorities of the first and third group were critically discussed. CONCLUSION: The Arab countries have made substantial economic and social progress during the last decades by improving life expectancy and reducing maternal and infant mortality. However, considering its natural wealth and human resources, the Arab region has accomplished less than expected in terms of human development. Huge social inequalities and health inequities exist inter and intra Arab countries. In most Arab countries, a large percentage of populations, especially in rural areas, are deprived of access to health facilities. Consequently, many women still die during pregnancy and labour, yielding unacceptable levels of maternal and infant mortality. However, the problem is seen to be more complex, going beyond geography and technical accessibility to health care, it compasses, among others, levels of literacy, low social and economic status of women, qualification of health staff, general behaviour and interactions between patients and medical personnel (including corruption).