Advanced Evolution Of Massive Stars .4. Secondary Nucleosynthesis During Helium Burning

NSF GP-32051, GP-23282Astronom

Fisheries Management in the Regional and International Contexts: Columbia River Basin

7 pages. Contains references

Lunar excursion module RCS engine vacuum chamber contamination study

Plume deposits of reaction control system in lunar excursion model engine vacuum chamber and contamination of test bed

Contestable adulthood: variability and disparity in markers for negotiating the transition to adulthood

Recent research has identified a discreet set of subjective markers that are seen as characterizing the transition to adulthood. The current study challenges this coherence by examining the disparity and variability in young people’s selection of such criteria. Four sentence-completion cues corresponding to four differentcontexts in which adult status might be contested were given to 156 British 16- to 17-year-olds. Their qualitative responses were analyzed to explore patterns whilst capturing some of their richness and diversity. An astonishing amount of variability emerged, both within and between cued contexts.The implications of this variability for how the transition to adulthood is experienced are explored. The argument is made that markers of the transition to adulthood are not merely reflective of the bio–psycho–social development of young people. Rather, adulthood here is seen as an essentially contested concept,located within the discursive interactional environment in which young people participate

Rapid neutron capture in supernova explosions

Rapid neutron capture in supernova explosion

The natural resources of Bolinas Lagoon: their status and future

This publication is an integral part of the Department's high-priority inventory and assessment of coastal marshland and tideflat resources. It is intended as a guide for citizens, planners, administrators, and all others interested in the use and development of coastal lands and waters. Although the resources and problems of Bolinas Lagoon have probably been the subject of more biological and physical investigations than any small estuarine area of the California coast, many of the pertinent reports and information are not readily available to the public. Consequently, it is one purpose of this report to summarize the lagoon's history, ecological attractions, educational values and the problems facing its continued existence. At the same time, it should provide concerned citizens with a knowledge of the sources of additional and more specific information. Publication of this report is consistent with the obligation of the Department of Fish and Game to do everything in its power to protect and maintain the State's fish and wildlife resources. Therefore, its purpose transcends local issues on pollution and development, and the Department is, in fact, submitting a report to the people on the status and future of part of its inheritance and the dowry of coming generations. The report is the third of a scheduled series. It follows similar releases on Upper Newport Bay (Orange County) and Goleta Slough (Santa Barbara county) in March and June of 1970. Documentation of the resources of other critical areas is in progress. There will be future reports of this nature on Elkhorn Slough, Morro Bay, Tomales Bay, Humboldt Bay, and highly threatened marshlands in southern California. (137 pp.

Pyrophosphate: a key inhibitor of mineralisation

Inorganic pyrophosphate has long been known as a by-product of many intracellular biosynthetic reactions, and was first identified as a key endogenous inhibitor of biomineralisation in the 1960s. The major source of pyrophosphate appears to be extracellular ATP, which is released from cells in a controlled manner. Once released, ATP can be rapidly hydrolysed by ecto-nucleotide pyrophosphatase/phosphodiesterases to produce pyrophosphate. The main action of pyrophosphate is to directly inhibit hydroxyapatite formation thereby acting as a physiological 'water-softener'. Evidence suggests pyrophosphate may also act as a signalling molecule to influence gene expression and regulate its own production and breakdown. This review will summarise our current understanding of pyrophosphate metabolism and how it regulates bone mineralisation and prevents harmful soft tissue calcification

Experiential Learning Curricular Development Model for Stimulating Student Interest in Green Collar Careers

Green jobs are in high demand, yet there is lack of a trained workforce for the green industries. Early exposure to green careers can stimulate future employment interest among students. The purpose of this study was to evaluate the effectiveness of an experiential learning unit of instruction designed to expose students to and develop knowledge about the green collar workforce. The study used a mixed method research design. A purposive sample of 101 (n=101) secondary students in career development type classes were given a pre-test, treatment, and post-test that involved both quantitative and qualitative responses. The findings revealed that the developed curriculum did increase student awareness of, and knowledge about the green collar workforce. Educators interested in career guidance and work force preparation may adopt the curriculum examined, or choose to develop their own based off the same experiential learning theory principles used in the development of the green collar workforce curriculum

Massive Stars in the Range 13−25M⊙\rm 13-25 M_\odot: Evolution and Nucleosynthesis. II. the Solar Metallicity Models

We present the evolutionary properties of a set of massive stellar models (namely 13, 15, 20 and 25 $\rm M_\odot$) from the main sequence phase up to the onset of the iron core collapse. All these models have initial solar chemical composition, i.e. Y=0.285 and Z=0.02. A 179 isotope network, extending from neutron up to $\rm ^{68}Zn$ and fully coupled to the evolutionary code has been adopted from the Carbon burning onward. Our results are compared, whenever possible, to similar computations available in literature.Comment: 42 pages, 18 figures, 26 tables, accepted for publicatin in ApJ

Mediterranean House Geckos Exploit Novel Resources in a Recipient Lizard Assemblage

A species’ ecological niche represents the environmental conditions needed for an individual to replace itself and is comprised of multiple resource axes (Pianka 2000 Evol. Ecol.). One mechanism of establishment of non-native species is via exploitation of novel resources in recipient ecosystems through their unique functional traits (Schalk et al. 2018 Biol. Invas.). Mediterranean House Geckos (Hemidactylus turcicus) are an exotic species introduced in urban areas across Texas, yet little is known about their resource use relative to native lizards. We hypothesized that H. turcicus would exhibit low overlap in resource use in their habitat, dietary, and isotopic niches compared to native lizard species (Green Anole [Anolis carolinensis], Little Brown Skink [Scincella lateralis], Five-lined Skink [Plestiodon fasciatus])