Production of Acquired Immunodeficiency Syndrome-Associated Retrovirus in Human and Nonhuman Cells Transfected with an Infectious Molecular Clone

We constructed an infectious molecular clone of acquired immunodeficiency syndrome-associated retrovirus. Upon transfection, this clone directed the production of infectious virus particles in a wide variety of cells in addition to human T4 cells. The progeny, infectious virions, were synthesized in mouse, mink, monkey, and several human non-T cell lines, indicating the absence of any intracellular obstacle to viral RNA or protein production or assembly. During the course of these studies, a human colon carcinoma cell line, exquisitely sensitive to DNA transfection, was identified

Black Girls Speak STEM: Counterstories of Informal and Formal Learning Experiences

This study presents the interpretations and perceptions of Black girls who participated in I AM STEM – a community-based informal science, technology, engineering, and mathematics (STEM) program. Using narrative inquiry, participants generated detailed accounts of their informal and formal STEM learning experiences. Critical race methodology informed this research to portray the dynamic and complex experiences of girls of color, whose stories have historically been silenced and misrepresented. The data sources for this qualitative study included individual interviews, student reflection journals, samples of student work, and researcher memos, which were triangulated to produce six robust counterstories. Excerpts of the counterstories are presented in this article. The major findings of this research revealed that I AM STEM ignited an interest in STEM learning through field trips and direct engagement in scientific phenomena that allowed the girls to become agentic in continuing their engagement in STEM activities throughout the year. This call to awaken the voices of Black girls to speak casts light on their experiences and challenges as STEM learners ⎯ from their perspectives. The findings confirm that when credence and counterspaces are given to Black girls, they are poised to reveal their luster toward STEM learning. This study provided a space for Black girls to reflect on their STEM learning experiences, formulate new understandings, and make connections between the informal and formal learning environments within the context of their everyday lives, thus offering a more holistic approach to STEM learning that occurs across settings and over a lifetime

Land management impacts on water quality following fire in a major water supply catchment

Salvage harvesting and land clearance to re-establish radiata plantations in the lower catchment followed the January 2003 bushfires in the Cotter River water supply catchment. We report impacts of post-fire catchment disturbance on water quality and pre

What factors influence rapid post-fire site re-occupancy? A case study of the endangered Eastern Bristlebird in eastern Australia

We quantified the post-fire recovery of the endangered Eastern Bristlebird (Dasyornis brachypterus) at Booderee National Park, south-eastern Australia. Occurrence was recorded on 110 sites a year before, and for 3 years after a major unplanned fire in 2003. Although the Eastern Bristlebird is thought to be sensitive to wildfire, data indicated that the species either persisted continuously on burned sites or returned to previously occupied sites within 2 years. Post-fire site occupancy was associated with several factors: (1) pre-fire site occupancy; (2) vegetation type; (3) spatial heterogeneity in fire and the amount of unburned vegetation surrounding a site; and (4) site-level vegetation structure (e.g. diversity of understorey and midstorey plants). The most likely mechanism underpinning rapid re-occupancy was movement by resident birds to unburned parts elsewhere within their territories. The addition of intensive feral predator baiting within the present study suggests that predation may have a more important effect on populations after unplanned fires than formerly recognised. Our results have significant implications for fire management in areas where the Eastern Bristlebird occurs. Care should be taken with back-burning during unplanned fires and the spatial and temporal arrangement of prescribed fires to ensure unburned vegetation remains as refugia to facilitate bird persistence

Contrasting mammal responses to vegetation type and fire

The response of terrestrial mammals and arboreal marsupials to past burning history as well as a year prior to, and then for 4 years after, a major wildfire in 2003 at Booderee National Park, Jervis Bay Territory was quantified. The present study encompassed extensive repeated surveys at a set of 109 replicated sites stratified by vegetation type and fire history. It was found that most species exhibited significant differences in presence and abundance between major vegetation types. Detections of long-nosed bandicoot (Perameles nasuta) increased significantly in all vegetation types surveyed, in both burnt and unburnt areas. Temporal patterns in captures of three species of small mammals (bush rat (Rattus fuscipes), swamp rat (Rattus lutreolus) and brown antechinus (Antechinus stuartii)) showed a trend for lower numbers of captures on burnt sites compared with unburnt sites. Three species of arboreal marsupials, common ringtail possum (Pseudocheirus peregrinus), greater glider (Petauroides volans) and common brushtail possum (Trichosurus vulpecula), were moderately common and all showed marked differences in abundance between vegetation types. Whereas P. peregrinus and P. volans exhibited a temporal decline between 2003 and 2006, T. vulpecula exhibited a general increase from 2003 levels. However, arboreal marsupial responses did not appear to be directly fire related