The life cycle of flowering plants alternates between two heteromorphic generations: a diploid sporophytic generation and a haploid gametophytic generation. During the development of the plant reproductive lineages – the germlines – typically, single sporophytic (somatic) cells in the flower become committed to undergo meiosis. The resulting spores subsequently develop into highly polarized and...

Malaria parasite transmission requires differentiation of male and female gametocytes into gametes within a mosquito following a blood meal. A mosquito-derived molecule, xanthurenic acid (XA), can trigger gametogenesis, but the signalling events controlling this process in the human malaria parasite Plasmodium falciparum remain unknown. A role for cGMP was revealed by our observation that zapri...

In this article, an evolutionary perspective is applied to individual differences. Among the issues discussed are (a) the seminal contributions of Francis Galton and the subsequent ideological reaction, (b) the distal proximal continuum for understanding levels of explanation in social behavior, (c) consistent patterns of group differences in behavior (age, sex, social class,and race), (d) the ...

The life cycle of flowering plants alternates between two heteromorphic generations: a diploid sporophytic generation and a haploid gametophytic generation. During the development of the plant reproductive lineages - the germlines - typically, single sporophytic (somatic) cells in the flower become committed to undergo meiosis. The resulting spores subsequently develop into highly polarized and...

Faithful chromosome segregation in meiosis is essential for ploidy stability over sexual life cycles. In plants, defective chromosome segregation caused by gene mutations or other factors leads to the formation of unbalanced or unreduced gametes creating aneuploid or polyploid progeny, respectively. Accurate segregation requires the coordinated execution of conserved processes occurring through...

Spermatogenesis is a fundamental biological process that ensures the transition of a gene from one ganeration to another via male gametes. This process relies on a rare population of testicular cells called spermatogonial stem cells (SSCs), which self-renew throughout adult male life and differentiate into mature gametes. Despite the longstanding study of SSCs, their biological properties remai...

escalating development of tourism and petroleum industries in small islands such as lavan-iranrequires sound solid waste management. in the present investigation, three scenarios which consist of thecombination of landfill, recycling, incineration and composting and their environmental impacts have beenevaluated for 7514 kg/day of waste generation in lavan island. for this purpose, life cycle a...

in this study a pseudo comprehensive carbon footprint model for fossil fuel power plants is presented. parameters which their effects are considered in this study include: plant type, fuel type, fuel transmission type, internal consumption of the plant, degradation, site ambient condition, transmission and distribution losses. investigating internal consumption, degradation and site ambient con...

kambeiz talebi, the author of the article discusses the urgent needfor topmanagers to change their style in small entrepreneurial firms during a business life cycle. although most leadership theories assume that it is an easy task, but the case studies and practical experience suggest the opposite - managers find it hard to move from an innovative style when the company is young to taskoriente...