Factors Affecting the Unit Cost of Weapon Systems

This research identifies variables and specifies equations that can be used to estimate the unit production cost of a weapon system. It is concerned with both explanation and prediction. Three major variables identified are cumulative quantity, production rate, and change in regime. Cumulative quantity is used in learning curve theory. Production rate is found in the U-shaped short and long-run cost curves of economic theory. This study uses the term regime to refer to any major change in the production environment of a weapon system. This research attempts to integrate the use of these three variables. A change in regime may be due to a change in acquisition strategy, configuration, or manufacturing method. It is recommended that a categorical variable be used to capture the effect of a change in regime. Several specific equations are proposed and discussed. In general, they entail a shift, shift and rotation, or shift and two rotations of the cost quantity rate surface due to a change in regime. Many accepted methods of integrating learning and rate do not produce U-shaped rate curves; this study suggests one that does. Principles and equations discussed are applied in modeling the cost history of three missile systems

Intense molecular emission from the Lagoon nebula, M8

The discovery is reported of the second strongest source of mm and submm wavelength CO line emission, towards M8, the Lagoon Nebula in Sagittarius. The ~31 M⊙ molecular core has dimensions ~0.2 x 0.3pc and is centred on the O7V star Herschel 36 (H36), near the Hourglass Nebula in the core of M8. Emission from the CO line wings extends to the north and south of the Hourglass, although a lack of near-IR H2 emission indicates that outflow activity is much less prominent than in many active star-formation regions, and suggests that the CO line wings may trace the expanding edge of a cavity around H36. The molecular line data are compared with new near-IR narrow-band, continuum-subtracted images in He I, H2, and H,+ (Brγ) lines and archival HST emission-line images in Hα, [O III], and [S II]. The optical and near-IR data are found to be broadly consistent with previous photo-ionisation models of the Hourglass, which is excited by H 36. However, there are variations in the He I/Brγ line ratio which are difficult to explain

Effects on Freshwater Organisms of Magnetic Fields Associated with Hydrokinetic Turbines

Underwater cables will be used to transmit electricity between turbines in an array (interturbine cables), between the array and a submerged step-up transformer (if part of the design), and from the transformer or array to shore. All types of electrical transmitting cables (as well as the generator itself) will emit EMF into the surrounding water. The electric current will induce magnetic fields in the immediate vicinity, which may affect the behavior or viability of animals. Because direct electrical field emissions can be prevented by shielding and armoring, we focused our studies on the magnetic fields that are unavoidably induced by electric current moving through a generator or transmission cable. These initial experiments were carried out to evaluate whether a static magnetic field, such as would be produced by a direct current (DC) transmitting cable, would affect the behavior of common freshwater fish and invertebrates

Enhanced mtDNA repair and cellular survival following oxidative stress by targeting the hOGG repair enzyme to mitochondria.

Oxidative damage to mtDNA has been implicated as a causative factor in many disease processes and in aging. We have recently discovered that different cell types vary in their capacity to repair this damage, and this variability correlates with their ability to withstand oxidative stress. To explore strategies to enhance repair of oxidative lesions in mtDNA, we have constructed a vector containing a mitochondrial transport sequence upstream of the sequence for human 8-oxoguanine glycosylase. This enzyme is the glycosylase/AP lyase that participates in repair of purine lesions, such as 8-oxoguanine. Western blot analysis confirmed this recombinant protein was targeted to mitochondria. Enzyme activity assays showed that mitochondrial extracts from cells transfected with the construct had increased enzyme activity compared to cells transfected with vector only, while nuclear enzyme activity was not changed. Repair assays showed that there was enhanced repair of oxidative lesions in mtDNA. Additional studies revealed that this augmented repair led to enhanced cellular viability as determined by reduction of tetrazolium compound to formazan, Trypan blue dye exclusion, and clonogenic assays. Therefore, targeting of DNA repair enzymes to mitochondria may be a viable approach for the protection of cells against some of the deleterious effects of oxidative stress