Suburbanization of Office Space: A Case Study of Houston, Texas.

Since the 1950s, the service sector of the U.S. economy has experienced remarkable growth. Significantly, new jobs in business and professional services and in similar information-processing occupations required new workplaces. Consequently, thousands of office complexes were built in American cities. Displaying a clean break with the past trend, the majority of the new office complexes were constructed in suburban locations, outside the CBDs of most major cities. The purpose of this research is to investigate the relationships between office complexes and urban labor markets/urban spatial structure. The scope of the empirical work is confined to office suburbanization in Houston, Texas PMSA (Harris County) and covers the period from 1970 to 1990. The research utilizes census-tract level socioeconomic data from the U.S. Census of Population and Housing (1970, 1980, and 1990) and data on individual office buildings from Black\u27s Office Guide to examine, by means of statistical modeling, the relationships between the location of the intrametropolitan workforce and the location of office space. Three sets of spatial regression models are formulated in this research: (A) the amount of office space as a function of workforce characteristics; (B) the length of commute as a function of workforce characteristics; and (C) the change in housing values as a function of changes in office stock. Results of statistical modeling indicate that in Houston, during the period from 1970 to 1990, suburbanizing office complexes targeted the residential areas of white-collar office workers. As a result of this trend, residential areas with high concentrations of white-collar office workers are found to be characterized now with shorter commutes to work. Finally, positive effects of office space on housing values, particularly in the 1980s, were detected. Results of the study suggest that suburbanization of office complexes leads to polarization of urban space and creates dangerous imbalances in the urban spatial structure. Examples of such imbalances include job-housing mismatch and difficulties associated with access to suburban jobs for low-income workers. Therefore, successful urban planning and urban social policies must necessarily be geographically-informed

Structural elucidation of a novel mechanism for the bacteriophage-based inhibition of the RNA degradosome.

In all domains of life, the catalysed degradation of RNA facilitates rapid adaptation to changing environmental conditions, while destruction of foreign RNA is an important mechanism to prevent host infection. We have identified a virus-encoded protein termed gp37/Dip, which directly binds and inhibits the RNA degradation machinery of its bacterial host. Encoded by giant phage фKZ, this protein associates with two RNA binding sites of the RNase E component of the Pseudomonas aeruginosa RNA degradosome, occluding them from substrates and resulting in effective inhibition of RNA degradation and processing. The 2.2 Å crystal structure reveals that this novel homo-dimeric protein has no identifiable structural homologues. Our biochemical data indicate that acidic patches on the convex outer surface bind RNase E. Through the activity of Dip, фKZ has evolved a unique mechanism to down regulate a key metabolic process of its host to allow accumulation of viral RNA in infected cells.Fonds Wetenschappelijk Onderzoek (Grant ID: G.0599.11); Agentschap voor Innovatie door Wetenschap en Technologie (Grant ID: SBO 100042); Fonds Wetenschappelijk Onderzoek (Scholarship); Wellcome Trust (Scholarship); Onderzoeksraad, KU Leuven (Grant ID: GOA Bacteriophage Biosystems); Onderzoeksraad, KU Leuven (Grant ID: CREA/09/017)This is the final version of the article. It first appeared from eLife via http://dx.doi.org/10.7554/eLife.1641

Things Are Getting Hairy: Enterobacteria Bacteriophage vB_PcaM_CBB

Enterobacteria phage vB_PcaM_CBB is a jumbo phage belonging to the family Myoviridae. It possesses highly atypical whisker-like structures along the length of its contractile tail. It has a broad host range with the capability of infecting species of the genera Erwinia, Pectobacterium, and Cronobacter. With a genome of 355,922 bp, excluding a predicted terminal repeat of 22,456 bp, phage CBB is the third largest phage sequenced to date. Its genome was predicted to encode 554 ORFs with 33 tRNAs. Based on prediction and proteome analysis of the virions, 29% of its predicted ORFs could be functionally assigned. Protein comparison shows that CBB shares between 3338% of its proteins with Cronobacter phage GAP32, coliphages PBECO4 and 121Q as well as Klebsiella phage vB_KleM_Rak2. This work presents a detailed and comparative analysis of vB_PcaM_CBB of a highly atypical jumbo myoviridae phage, contributing to a better understanding of phage diversity and biology.Funding was provided by Cork Institute of Technology as a PhD fellowship to CB

The use of genomic signature distance between bacteriophages and their hosts displays evolutionary relationships and phage growth cycle determination

<p>Abstract</p> <p>Background</p> <p>Bacteriophage classification is mainly based on morphological traits and genome characteristics combined with host information and in some cases on phage growth lifestyle. A lack of molecular tools can impede more precise studies on phylogenetic relationships or even a taxonomic classification. The use of methods to analyze genome sequences without the requirement for homology has allowed advances in classification.</p> <p>Results</p> <p>Here, we proposed to use genome sequence signature to characterize bacteriophages and to compare them to their host genome signature in order to obtain host-phage relationships and information on their lifestyle. We analyze the host-phage relationships in the four most representative groups of Caudoviridae, the dsDNA group of phages. We demonstrate that the use of phage genomic signature and its comparison with that of the host allows a grouping of phages and is also able to predict the host-phage relationships (lytic <it>vs</it>. temperate).</p> <p>Conclusions</p> <p>We can thus condense, in relatively simple figures, this phage information dispersed over many publications.</p

A bacteriophage-related chimeric marine virus infecting abalone

Extent: 12p.Marine viruses shape microbial communities with the most genetic diversity in the sea by multiple genetic exchanges and infect multiple marine organisms. Here we provide proof from experimental infection that abalone shriveling syndrome-associated virus (AbSV) can cause abalone shriveling syndrome. This malady produces histological necrosis and abnormally modified macromolecules (hemocyanin and ferritin). The AbSV genome is a 34.952-kilobase circular double-stranded DNA, containing putative genes with similarity to bacteriophages, eukaryotic viruses, bacteria and endosymbionts. Of the 28 predicted open reading frames (ORFs), eight ORF-encoded proteins have identifiable functional homologues. The 4 ORF products correspond to a predicted terminase large subunit and an endonuclease in bacteriophage, and both an integrase and an exonuclease from bacteria. The other four proteins are homologous to an endosymbiont-derived helicase, primase, single-stranded binding (SSB) protein, and thymidylate kinase, individually. Additionally, AbSV exhibits a common gene arrangement similar to the majority of bacteriophages. Unique to AbSV, the viral genome also contains genes associated with bacterial outer membrane proteins and may lack the structural protein-encoding ORFs. Genomic characterization of AbSV indicates that it may represent a transitional form of microbial evolution from viruses to bacteria.Jun Zhuang, Guiqin Cai, Qiying Lin, Zujian Wu and Lianhui Xi

Forecasting the Explosive Removal of Offshore Structures

This report summary describes the objective of the research is to examine how offshore structures producing and processing hydrocarbons are removed from the Gulf of Mexico. Using this research, they developed a model to forecast the removal of offshore structures