Nicholas C. Field

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Microbial ecologists and systematists are challenged to discover the early ecological changes that drive the splitting of one bacterial population into two ecologically distinct populations. We have aimed to identify newly divergent lineages ("ecotypes") bearing the dynamic properties attributed to species, with the rationale that discovering their(More)
Most amyotrophic lateral sclerosis (ALS) cases occur sporadically. Some environmental triggers have been implicated, including beta-methylamino-L-alanine (BMAA), a cyanobacteria produced neurotoxin. This study aimed to identify environmental risk factors common to three sporadic ALS patients who lived in Annapolis, Maryland, USA and developed the disease(More)
Sporadic amyotrophic lateral sclerosis (sALS) is a fatal neurodegenerative disease with no known cause. There are many clues to suggest an environmental trigger for the disease, including reports of conjugal couples and co-localized employees that developed sALS. On the island of Guam,a very high incidence of sALS occurred among the Chamorro natives back in(More)
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative syndrome which has no known cause, except for a small proportion of cases which are genetically inherited. The development of ALS likely involves both genetic and environmental risk factors. Environmental risk factors implicated in ALS have included heavy metals, trauma, pesticides, electrical(More)
BACKGROUND Recent data provide support for the concept that potentially modifiable exposures are responsible for sporadic amyotrophic lateral sclerosis (ALS). OBJECTIVE To evaluate environmental and occupational exposures as risk factors for sporadic ALS. METHODS We performed a case-control study of ALS among residents of New England, USA. The analysis(More)
An 84-year-old gentleman presented with onset of gross hematuria in September 2010. Follow-up investigations revealed T1 superficially invasive, poorly differentiated, papillary urothelial carcinoma. He subsequently had GreenLight laser for BPH and bladder neck contracture on two occasions. He developed a right hydrocele 16 months after initial presentation(More)
"The objective in this study has been to produce...a comprehensive inventory and analysis of the transfer of Canada's population between the rural and urban sectors and of the pattern of population exchange between the various levels of the urban hierarchy. The hierarchical exchanges have been investigated both for Canada's rural-urban system in the(More)
INTRODUCTION An environmental trigger of sporadic amyotrophic lateral sclerosis (ALS) is supported by geographic disparities in ALS incidence and development of the disease in conjugal couples. This study aims to investigate the incidence of ALS in the Northern New England states of New Hampshire (NH), Vermont (VT), and Maine (ME). METHODS We reviewed(More)
"This paper describes a system of versatile software packages that has been developed by the author for population analysis on IBM-compatible microcomputers using PC or MS DOS. The series includes programs for the production of life tables, the analysis of spatial patterns and temporal trends in mortality, population projections, stationary-state(More)