The Effect of Education on the Timing of Marriage and First Conception in Pakistan.

It is often argued that a rapid rise in educational attainment of women, an increase in the age at marriage and an increase in the age at first birth are key features of demographic transition in any country. Education is the prime catalyst in this process because increases in educational attainment are likely to significantly affect both age at marriage and the duration to first conception-in particular increasing both the age at marriage and the time to first child. This paper uses individual level unit record data from Pakistan to examine the effect of education on the age at marriage and on the duration between marriage and first conception. We estimate a structural model, which accounts for the interaction between the three main variables of interest. Our estimation results show that women who have more education delay marriage but increased educational attainment does not have a significant effect on the duration to first conception. Women who marry late have a child faster. Education of the husband significantly affects the time to conception.EDUCATION ; MARRIAGE ; FERTILITY

Merging KK-means with hierarchical clustering for identifying general-shaped groups

Clustering partitions a dataset such that observations placed together in a group are similar but different from those in other groups. Hierarchical and $K$-means clustering are two approaches but have different strengths and weaknesses. For instance, hierarchical clustering identifies groups in a tree-like structure but suffers from computational complexity in large datasets while $K$-means clustering is efficient but designed to identify homogeneous spherically-shaped clusters. We present a hybrid non-parametric clustering approach that amalgamates the two methods to identify general-shaped clusters and that can be applied to larger datasets. Specifically, we first partition the dataset into spherical groups using $K$-means. We next merge these groups using hierarchical methods with a data-driven distance measure as a stopping criterion. Our proposal has the potential to reveal groups with general shapes and structure in a dataset. We demonstrate good performance on several simulated and real datasets.Comment: 16 pages, 1 table, 9 figures; accepted for publication in Sta

Some aspects of changes in Kenya's import structure.

Changes in the structure of imports in a developing country are closely associated with the level and progress of industrialisation. Industrialisation in these economies at the initial stage tends to be restricted by the available level of skill and organisational ability, to the simpler processes which are typical of non-durable consumer goods .At this stage obviously imports of intermediate and capital goods increase, but it is also evident from the empirical studies that the imports of consumer goods increase, even those which are now manufactured domestically, but to the expansion of the size of the market . Income elasticises of demand for consumer goods at the initial stage of industrialisation appear to be high in these economies. With the progress of industrialisation new skills and organisational abilities emerge, while the expanding markets allow new industries - in course of time intermediate and capital goods producing industries. These would naturally lead to changes in the composition of imports

Magnetic properties of doped GdI2

Motivated by the recent experimental studies on layered ferromagnetic metallic system GdI2 and its doped variant GdI2Hx we develop a model to understand their ground state magnetic phase diagram. Based on first principle electronic structure calculations we write down a phenomenological model and solve it under certain approximations to obtain the ground state energy. In the process we work out the phase diagram of the correlated double exchange model on a triangular lattice for the specific band structure at hand.Comment: 13 pages, 5 figures, corrected typo

Glucose and fructose metabolism in a posphoglucoisomeraseless mutant of Saccharomyces cerevisiae

A mutant of Saccharomyces cerevisiae deficient in phosphoglucoisomerase (EC 5.3.1.9) is described. It does not grow on glucose or sucrose but does grow on galactose or maltose. Addition of glucose to cultures growing on fructose, mannose, or acetate arrests further growth without altering viability; removal of glucose permits resumption of growth. Glucose causes accumulation of nearly 30 µmoles of glucose-6-phosphate per g (wet weight) of cells and suppresses synthesis of ribonucleic acid. Inhibition of growth by glucose does not appear to be due to a loss of adenosine triphosphate or inorganic orthophosphate. The mutant, however, utilizes glucose-6-phosphate produced intracellularly. Release of carbon dioxide from specifically labeled glucose suggests a C-l preferential cleavage. The kinetics of glucose-6-phosphate accumulation during glucose utilization in the mutant is not consistent with the notion that the utilization of glucose is controlled by glucose-6-phosphate

A glucokinase from Saccharomyces cerevisiae

An ATP:D-glucose 6-phosphotransferase (EC 2.7.1.2) or glucokinase from Saccharomyces cerevisiae is described. The enzyme has been purified about 100-fold from the crude extracts of a hexokinaseless mutant derived from a haploid strain of S. cerevisiae. The Km values for glucose and ATP are 28 and 50 µm, respectively. The maximal velocity of this enzyme toward fructose is 0.4% of that of glucose. The enzyme showed a marked heterogeneity when sedimented in a sucrose density gradient, its molecular weight ranging from 144,000 to a value in excess of 200,000. Yeast glucokinase shares a number of properties with yeast hexokinase (EC 2.7.1.1) in the semiconstitutive nature of its synthesis with glucose, its broad pH optima, and inhibition with ADP and N-acetylglucosamine. Its mode of reaction with glucose and ATP, as indicated by initial velocity patterns, appears to be random