Accreditation at the US EPA-NEIC. National Enforcement Investigations Center

The US Environmental Protection Agency-National Enforcement Investigations Center (NEIC) of Denver, Colorado is the specialty technical arm of the Office of Enforcement and Compliance Assurance (OECA) within the US EPA. NEIC is a center for technical support nationwide to state, local, tribal, and federal environmental enforcement and compliance assurance programs. NEIC is a source of expertise for technical analysis, compliance monitoring, engineering evaluations, forensic laboratory activities, information management, computer forensics, and witness testimony. Effective 1 February 2001, NEIC was granted accreditation for overall environmental measurement activities that include field sampling, field measurements and monitoring, and laboratory measurements. NEIC became the first and only environmental forensic center in the United States to be granted this type of accreditation. The accreditation criteria incorporates nationally and internationally accepted forensic and quality management standards. Awarded by the National Forensic Science Technology Center (NFSTC), the NEIC Accreditation Standard was developed for conducting environmental measurements while adhering to forensic requirements in specific areas. The NEIC Accreditation Standard is based on ISO/IEC Guide 25 and ANSI/ASQC E4-1994, and it references specific aspects of the American Society of Crime Laboratory Directors/Laboratory Accreditation Board (ASCLD/LAB) Manual.

Assembly of thick filaments and myofibrils occurs in the absence of the myosin head

We investigated the importance of the myosin head in thick filament formation and myofibrillogenesis by generating transgenic Drosophila lines expressing either an embryonic or an adult isoform of the myosin rod in their indirect flight muscles. The headless myosin molecules retain the regulatory light-chain binding site, the alpha-helical rod and the C-terminal tailpiece. Both isoforms of headless myosin co-assemble with endogenous full-length myosin in wild-type muscle cells. However, rod polypeptides interfere with muscle function and cause a flightless phenotype. Electron microscopy demonstrates that this results from an antimorphic effect upon myofibril assembly. Thick filaments assemble when the myosin rod is expressed in mutant indirect flight muscles where no full-length myosin heavy chain is produced. These filaments show the characteristic hollow cross-section observed in wild type. The headless thick filaments can assemble with thin filaments into hexagonally packed arrays resembling normal myofibrils. However, thick filament length as well as sarcomere length and myofibril shape are abnormal. Therefore, thick filament assembly and many aspects of myofibrillogenesis are independent of the myosin head and these processes are regulated by the myosin rod and tailpiece. However, interaction of the myosin head with other myofibrillar components is necessary for defining filament length and myofibril dimensions.