According to the selfish operon hypothesis, the clustering of genes and their subsequent organization into operons is beneficial for the constituent genes because it enables the horizontal gene transfer of weakly selected, functionally coupled genes. The majority of these are expected to be non-essential genes. From our analysis of the Escherichia coli genome, we conclude that the selfish opero...

A rhythmic tremor at about 10 c./sec. is a wellknown feature of muscular contraction in healthy adults. In some subjects the amplitude of the tremor is such that it is discernible by the naked eye, while in others sensitive methods of recording are required for its detection. While studying this phenomenon Marshall and Walsh (1956) noticed that the tremor in six normal children was slower than ...

A central undertaking in synthetic biology (SB) is the quest for the 'minimal genome'. However, 'minimal sets' of essential genes are strongly context-dependent and, in all prokaryotic genomes sequenced to date, not a single protein-coding gene is entirely conserved. Furthermore, a lack of consensus in the field as to what attributes make a gene truly essential adds another aspect of variation....

The concept of robustness in biology has gained much attention recently, but a mechanistic understanding of how genetic networks regulate phenotypic variation has remained elusive. One approach to understand the genetic architecture of variability has been to analyze dispensable gene deletions in model organisms; however, the most important genes cannot be deleted. Here, we have utilized two sy...

A strategy based on a vector host-dependent for autonomous replication, pSA3182, was utilized both for the rapid screening for Staphylococcus aureus genes essential for cell viability and for the introduction of specific polarity-neutral deletions in nonessential genes. The results obtained support the use of pSA3182 for both purposes.

ii Abbreviations iv Manuscripts vi Populärvetenskaplig sammanfattning på svenska vi

The concept proposed by WHO of an essential drugs list that should comprise drugs corresponding to the health needs of the majority of the people has been embraced by countries, which have adapted it to their needs. In this study, the essential antibacterial drug lists of 16 countries chosen from the six WHO regions are reviewed. Most of these countries include 73% of WHO-recommended essential ...

This final recommendation statement applies to children and adolescents (teens) from birth to age 18 who do not have signs or symptoms of high blood pressure or of an underlying health problem that could cause high blood pressure. The Task Force reviewed recent research studies on screening for high blood pressure in children and teens. The final recommendation statement summarizes what the Tas...