distribution and abundance of plants has been correlated with a variety of complex environmental gradients. environmental factors affect plants growth and need to be understood by ecosystem managers. this study was carried out to examine the relationships between site factors and different vascular and non-vascular plants in north of iran. for this purpose, vegetation and soil sampling was perf...

The heritability of human longevity was investigated in a sample of 218 pairs of monozygotic (MZ) and 382 pairs of like-sex dizygotic (DZ) Danish twin pairs born 1870-1880. Twin similarity for age at death was significant for MZ twins but nonsignificant for DZ twins. The heritability (h2) of life span estimated from the best-fitting biometrical model was statistically significant but moderate i...

Evaluation of the interaction between a new and the existing underground structures is one of the important problems in urban tunneling. In this work, using FLAC3D, four numerical models of single- and twin-tube tunnels in urban areas are developed, where the horizontal distance between the single- and twin-tube tunnels are varied. The aim is to analyze the effects of the horizontal dista...

Sudden ice shedding from conductor bundles was modeled numerically and experimentally by improving the approaches proposed formerly for a single cable. The experimental study was carried out on a small-scale laboratory model of one span of a twin bundle. A numerical model of the experimental set-up was developed using the commercial finite element software ADINA. This model was validated by sim...

BACKGROUND Previous research has reported that greater intelligence in early life is associated with longer lifespan. Whether this relationship is mediated by genetic factors or environmental factors, some of which could be modified by an individual, is unclear. OBJECTIVE We examined the association between intelligence test scores, obtained during the 1940s, and age at death in a group of 49...

environmental components in the variability of anthropometric measurements were studied in 54 twin pairs. Thirty pairs of monozygotic (MZ) and 24 pairs of dizygotie (DZ) twins were investigated to estimate the role of genetic, environmental arid hereditary factors determininganthropometriemeasurementseomprising body weight, standing height, sitting height, knee height, arm span, chest cireumfer...

This paper reviews the recent literature on genes and longevity. The influence of genes on human life span has been confirmed in studies of life span correlation between related individuals based on family and twin data. Results from major twin studies indicate that approximately 25% of the variation in life span is genetically determined. Taking advantage of recent developments in molecular bi...

The longitudinal rank-order stability of cognitive ability increases dramatically over the life span. Theoretical perspectives differ in their emphasis on genetic mechanisms in explaining the longitudinal stability of cognition and how stability changes with development. However, the patterns of stability of genetic and environmental influences on cognition over the life span remain poorly unde...

In this work, a statistical analysis on greenhouse simulations to estimate the efficiency of natural ventilation in a commercial twin-span greenhouse is presented. A numerical simulation approach was adopted using the theory of threedimensional computational fluid dynamics (CFD). With this approach, threedimensional patterns for temperature and airspeed inside the greenhouse were generated, usi...

We investigated sex differences in genetic and environmental effects on cognitive abilities among older adult twins. We drew participants from the Swedish Twin Registry; our sample included 647 twin pairs. Our cognitive measures included Synonyms, Block Design, Digit Span, Thurstone's Picture Memory, Symbol Digit, and general cognitive ability tests. Higher age was related to lower performance ...