Assessing Fitness for Military Enlistment, Physical, Medical, and Mental Health Standards

The document of record as published may be found at https://doi.org/10.17226/11511Assessing Fitness for Military Enlistment examines the current physical, medical, and mental health standards for military enlistment in light of (1) trends in the physical condition of the youth population; (2) medical advances for treating certain conditions, as well as knowledge of the typical course of chronic conditions as young people reach adulthood; (3) the role of basic training in physical conditioning; (4) the physical demands and working conditions of various jobs in today's military services; and (5) the measures that are used by the Services to characterize an individual's physical condition. The focus is on the enlistment of 18- to 24-year-olds and their first term of service

Shielding of Sleeping Beauty DNA Transposon-delivered Transgene Cassettes by Heterologous Insulators in Early Embryonal Cells

The Sleeping Beauty (SB) transposon system represents an important alternative to viral integrating vector systems but may, as its viral counterparts, be subject to transcriptional silencing. To investigate shielding of SB-delivered transgene cassettes against transcriptional repression, we establish silencing assays in which SB vector–containing F9 murine teratocarcinoma cell clones are identified by strategies that include or exclude selection for transgene expression. Among clones carrying one or more SB transposon vectors, more than one-third are immediately silenced, and most of the remaining clones move toward silencing during prolonged passage. In line with the lack of an intrinsic ability of SB to resist silencing, we show that the stable transfection rate of SB vectors in F9 cells is significantly improved by flanking the transgene with heterologous 5′-HS4 chicken β-globin (cHS4) insulators. In approaches based on drug selection and subsequent flow-cytometric detection of transgene expression, clones containing cHS4-insulated vectors are to a much higher degree protected against transcriptional silencing, resulting in long-term expression of the fluorescent marker. Our findings demonstrate that SB vectors, prone for transcriptional silencing by positional effects in F9 cells, are protected by insulators. We believe that insulated SB-derived vectors will become useful tools in transposon-based transgenesis and therapeutic gene transfer