Combining R&D and Follow-on Production in a Single Contract

During the past three years there has been a concentrated effort by the Government to shift from Cost-Plus-Fixed Fee Contracts to Incentive Contracts. The basic purpose of this shift is to put more of the burden of financial risk on the contractor and to reward contractors who successful ly perform on their contracts with higher profits. Another trend is developingof combining R & D, Production and Logistics Support into a single contract based upon Air Force Secretary Charles Total Package Concept \u27. Since the purpose of these changes is to shift more risks from the Government to the Contractor, the tendency is often to select the type of contract whereby the contractor assumes the maximum risk. This of course is the Fixed Price Contract. However, due to the nature of the circumstances surrounding the procurement, the Fixed Price Contract may not be the most appropriate nor in the best interests of the Government. The purpose of this Article is to describe a type of Contract for use when it is desired to combine R & D and Production in a single contract. In designing this contract, it is a goal to reduce or eliminate problems which have caused concern to the Government and still not go to the extreme and require the contractor to assume more risk than sound business judgment would dictate

Sperm wars and the evolution of male fertility

Females frequently mate with several males, whose sperm then compete to fertilize available ova. Sperm competition represents a potent selective force that is expected to shape male expenditure on the ejaculate. Here, we review empirical data that illustrate the evolutionary consequences of sperm competition. Sperm competition favors the evolution of increased testes size and sperm production. In some species, males appear capable of adjusting the number of sperm ejaculated, depending on the perceived levels of sperm competition. Selection is also expected to act on sperm form and function, although the evidence for this remains equivocal. Comparative studies suggest that sperm length and swimming speed may increase in response to selection from sperm competition. However, the mechanisms driving this pattern remain unclear. Evidence that sperm length influences sperm swimming speed is mixed and fertilization trials performed across a broad range of species demonstrate inconsistent relationships between sperm form and function. This ambiguity may in part reflect the important role that seminal fluid proteins (sfps) play in affecting sperm function. There is good evidence that sfps are subject to selection from sperm competition, and recent work is pointing to an ability of males to adjust their seminal fluid chemistry in response to sperm competition from rival males. We argue that future research must consider sperm and seminal fluid components of the ejaculate as a functional unity. Research at the genomic level will identify the genes that ultimately control male fertility.</jats:p

Revision of the cerrado hemicryptophytic Chamaesyce of Boissier\u27s Pleiadeniae (Euphorbiaceae)

The species of Chamaesyce classified by Boissier as the Pleiadeniae\u27 are revised in light of presently available collections. Six species are accepted and new combinations are proposed for C. nana, C. setosa, C. tamanduana, and C. viscoides. Although these herbaceous perennials of cerrado vegetation of Brazil, northern Argentina, and adjacent countries are distinctive ecologically and geographically, cladistic analysis does not support their recognition as a monophyletic group

Evolution of Sexual Dimorphism and Male Dimorphism in the Expression of Beetle Horns: Phylogenetic Evidence for Modularity, Evolutionary Lability, and Constraint

Beetle horns are enlarged outgrowths of the head or thorax that are used as weapons in contests over access to mates. Horn development is typically confined to males (sexual dimorphism) and often only to the largest males (male dimorphism). Both types of dimorphism result from endocrine threshold mechanisms that coordinate cell proliferation near the end of the larval period. Here, we map the presence/absence of each type of dimorphism onto a recent phylogeny for the genus Onthophagits (Coleoptera: Scarabaeidae) to explore how horn development has changed over time. Our results provide empirical support for several recent predictions regarding the evolutionary lability of developmental thresholds, including uncoupled evolution of alternative phenotypes and repeated fixation of phenotypes. We also report striking evidence of a possible developmental constraint. We show that male dimorphism and sexual dimorphism map together on the phylogeny; whenever small males have horns, females also have horns (and vice versa). We raise the possibility that correlated evolution of these two phenomena results from a shared element in their endocrine regulatory mechanisms rather than a history of common selection pressures. These results illustrate the type of insight that can be gained only from the integration of developmental and evolutionary perspectives

AMPR/SSMI data comparisons

The AMPR was flown during CAPE and STORMFEST, during which some good data were gathered. Significant instrument noise problems were encountered in both deployments which appear to be temperature related. These are being fixed before the TOGA COARE deployment. New calibration loads have also been manufactured for the TOGA COARE configuration. Eric Smith at FSU had been analyzing the AMPR data and has written a journal article to be submitted early this summer. The emphasis of his work is on the interpretation of low resolution microwave data from space, based upon what we have learned from the high-resolution AMPR signatures

The Vascular Flora of the Potomac River Watershed of King George County, Virginia

The results of two floristic studies of King George County, Virginia, are combined into an annotated checklist. Field work was initiated in 1983-84 with a study of Caledon Natural Area, a 2,500-acre tract with 3.5 miles of frontage on the Potomac River. Collecting resumed in 1991 and 1992 to include other portions of the county drained by the Potomac River. The study area contains a wide variety of habitats including dry upland woods, mesic ravines, low elevation river flats, beaches, swamps, marshes, and creeks; creeks and marshes include both brackish and freshwater environments. The Potomac River watershed of King George County harbors a diverse assemblage of plants; the checklist includes documentation for 918 species of vascular plants classified in 466 genera and 130 families. This total includes 418 species that at the time of collection were the first records of occurrence in King George County

Wood Anatomy of \u3ci\u3eAmanoa\u3c/i\u3e (Euphorbiaceae)

Wood anatomy of 29 specimens of seven species of Amanoa from tropical Africa, South America, and the Caribbean is described. The wood is diffuse-porous with most vessels in short radical multiples. Vessel elements are notably long, have simple perforation plates and small, alternative intervessel pits; tyloses are present in heartwood. Libriform wood fibres bear thick walls. Axial parenchyma distribution is diffuse and diffuse-in-aggregates. Chambered crystalliferous axial parenchyma is common. Rays are heterocellular, narrow, and very tall. The species examined, all from moist lowland forests, have similar wood structure. Wood of Amanoa resembles that of other primitive Euphorbiaceae

Threshold Evolution in Exotic Populations of a Polyphenic Beetle

Polyphenic development is thought to play an important role in the evolution of phenotypic diversity and morphological novelties, yet the evolution of polyphenisms has rarely been documented in natural populations. Here we compare the morphologies of male dung beetles (Onthophagus taurus; Coleoptera: Scarabaeidae) from populations introduced to Australia and the eastern United States. Males in this species express two alternative morphologies in response to larval feeding conditions. Males encountering favourable conditions grow larger than a threshold body size and develop a pair of horns on their heads, whereas males that encounter poor conditions do not reach this threshold size and remain hornless. Australian and US populations did not differ in overall body size ranges, but exhibited significant differences in the location of the critical body size threshold that separates alternative male morphs. Australian males remained hornless at much larger body sizes than males in US populations, resulting in substantial and significant differences in the average body size-horn length allometry between exotic populations, as well as significant differences in morph ratios. The phenotypic divergence observed between field populations was maintained in laboratory populations after two generations under identical environmental conditions, suggesting a genetic basis to allometric divergence in these populations. Divergence between exotic O. taurus populations was of a magnitude and kind typically observed between species. We use our results to examine potential causes of allometric divergence in onthophagine beetles, and discuss the evolutionary potential of threshold traits and polyphenic development in the origin of morphological and behavioural diversity