Investigations of radiation-induced and spontaneous chromosomal inversion formation and characteristics

2014 Fall.To view the abstract, please see the full text of the document

Using radon to understand parafluvial flows and the changing locations of groundwater inflows in the Avon River, southeast Australia

This work is distributed under the Creative Commons Attribution 3.0 License (CC BY 3.0)Abstract. Understanding the location and magnitude of groundwater inflows to rivers is important for the protection of riverine ecosystems and the management of connected groundwater and surface water systems. This study utilizes 222Rn activities and Cl concentrations in the Avon River, southeast Australia, to determine the distribution of groundwater inflows and to understand the importance of parafluvial flow on the 222Rn budget. The distribution of 222Rn activities and Cl concentrations implies that the Avon River contains alternating gaining and losing reaches. The location of groundwater inflows changed as a result of major floods in 2011–2013 that caused significant movement of the floodplain sediments. The floodplain of the Avon River comprises unconsolidated coarse-grained sediments with numerous point bars and sediment banks through which significant parafluvial flow is likely. The 222Rn activities in the Avon River, which are locally up to 3690 Bq m−3, result from a combination of groundwater inflows and the input of water from the parafluvial zone that has high 222Rn activities due to 222Rn emanation from the alluvial sediments. If the high 222Rn activities were ascribed solely to groundwater inflows, the calculated net groundwater inflows would exceed the measured increase in streamflow along the river by up to 490 % at low streamflows. Uncertainties in the 222Rn activities of groundwater, the gas transfer coefficient, and the degree of hyporheic exchange cannot explain a discrepancy of this magnitude. The proposed model of parafluvial flow envisages that water enters the alluvial sediments in reaches where the river is losing and subsequently re-enters the river in the gaining reaches with flow paths of tens to hundreds of metres. Parafluvial flow is likely to be important in rivers with coarse-grained alluvial sediments on their floodplains and failure to quantify the input of 222Rn from parafluvial flow will result in overestimating groundwater inflows to rivers

An Investigation into the relationship between the gender binary and occupational discrimination using the implicit relational assessment procedure

The social construction of gender-as-binary plays an important role within many contemporary theories of gender inequality. However, to date, the field of psychology has struggled with the operationalization and assessment of binarist ideologies. The current article proposes a technical framework for the analysis of the gender binary and assesses the suitability of the Implicit Relational Assessment Procedure (IRAP) as a measure of binarist gender beliefs. Forty-seven undergraduate students (26 female; M-age = 23.84) completed two IRAPs assessing the coordination of certain traits exclusively with women and others exclusively with men. Effects found on the IRAP were in the expected direction (i.e., relating men but not women with certain traits and women but not men with other traits). In addition, the traits ascribed to men within the IRAP were evaluated as more hirable by a large majority of participants (83%) on an explicit preference task. The results therefore support the arguments that, first, gender traits do seem to be framed oppositionally in language and, second, this binary may underpin existing gender hierarchies in certain contexts

The hypoxic tissue microenvironment as a driver of mucosal inflammatory resolution

On the backdrop of all acute inflammatory processes lies the activation of the resolution response. Recent years have witnessed an emerging interest in defining molecular factors that influence the resolution of inflammation. A keystone feature of the mucosal inflammatory microenvironment is hypoxia. The gastrointestinal tract, particularly the colon, exists in a state of physiological hypoxia and during active inflammation, this hypoxic state is enhanced as a result of infiltrating leukocyte oxygen consumption and the activation of oxygen consuming enzymes. Most evidence suggests that mucosal hypoxia promotes the active resolution of inflammation through a variety of mechanisms, including extracellular acidification, purine biosynthesis/salvage, the generation of specialized pro-resolving lipid mediators (ie. resolvins) and altered chemokine/cytokine expression. It is now appreciated that infiltrating innate immune cells (neutrophils, eosinophils, macrophages) have an important role in molding the tissue microenvironment to program an active resolution response. Structural or functional dysregulation of this inflammatory microenvironment can result in the loss of tissue homeostasis and ultimately progression toward chronicity. In this review, we will discuss how inflammatory hypoxia drives mucosal inflammatory resolution and its impact on other microenvironmental factors that influence resolution

College Algebra (Fort Valley State University)

This Grants Collection for College Algebra was created under a Round Two ALG Textbook Transformation Grant. Affordable Learning Georgia Grants Collections are intended to provide faculty with the frameworks to quickly implement or revise the same materials as a Textbook Transformation Grants team, along with the aims and lessons learned from project teams during the implementation process. Documents are in .pdf format, with a separate .docx (Word) version available for download. Each collection contains the following materials: Linked Syllabus Initial Proposal Final Reporthttps://oer.galileo.usg.edu/mathematics-collections/1000/thumbnail.jp

Abortive Apoptosis and Its Profound Effects on Radiation, Chemical, and Oncogene-Induced Carcinogenesis

Traditionally apoptosis and the apoptotic machinery have been deemed as anticarcinogenic because of their presumed roles in eliminating damaged or unwanted cells. However, recent work from our laboratory and others have shown that the established paradigm is deeply flawed. The fundamental flaw is the assumption that apoptosis, once initiated, is irreversible and invariably leads to cell death. However, there is increasing evidence that cells can survive activation of the apoptotic cascade. This new revelation about abortive apoptotic cells can dramatically change our assessment of the biological roles of apoptosis. In this brief review, we will cover some of the original studies that report the "undead" apoptotic cells and how they lead to unexpected new roles for apoptotic factors in space radiation and other stress induced genetic instability and carcinogenesis. We will also review exciting new discoveries on the association among abortive apoptosis, spontaneous DNA double strand breaks, DNA damage response, and stemness of cancer cells

Estimating retention potential of headwater catchment using Tritium time series

Headwater catchments provide substantial streamflow to rivers even during long periods of drought. Documenting the mean transit times (MTT) of stream water in headwater catchments and therefore the retention capacities of these catchments is crucial for water management. This study uses time series of H-3 activities in combination with major ion concentrations, stable isotope ratios and radon activities (Rn-222) in the Lyrebird Creek catchment in Victoria, Australia to provide a unique insight into the mean transit time distributions and flow systems of this small temperate headwater catchment. At all streamflows, the stream has H-3 activities (< 2.4 TU) that are significantly below those of rainfall (similar to 3.2 TU), implying that most of the water in the stream is derived from stores with long transit times. If the water in the catchment can be represented by a single store with a continuum of ages, mean transit times of the stream water range from similar to 6 up to 40 years, which indicates the large retention potential for this catchment. Alternatively, variations of H-3 activities, stable isotopes and major ions can be explained by mixing between of young recent recharge and older water stored in the catchment. While surface runoff is negligible, the variation in stable isotope ratios, major ion concentrations and radon activities during most of the year is minimal (+/- 12%) and only occurs during major storm events. This suggests that different subsurface water stores are activated during the storm events and that these cease to provide water to the stream within a few days or weeks after storm events. The stores comprise micro and macropore flow in the soils and saprolite as well as the boundary between the saprolite and the fractured bed rock. Hydrograph separations from three major storm events using Tritium, electrical conductivity and selected major ions as well a delta O-18 suggest a minimum of 50% baseflow at most flow conditions.We demonstrate that headwater catchments can have a significant storage capacity and that the relationship between long-water stores and fast storm event subsurface flow is complex. The study also illustrates that using H-3 to determine mean transit times is probably only valid for baseflow conditions where the catchment can be represented as a single store.The results of this study reinforce the need to protect headwater catchments from contamination and extreme land use changes

Environmentally-friendly surface treatments

The presentation will focus upon both existing and novel developmental processes for the replacement of the hexavalent chromium containing 40/50V Bengough-Stuart anodise (CAA), with particular emphasis on their resultant performance in structurally bonded systems. Two systems of particular interest are based upon a phosphoric acid based electrolytic deoxidiser (EPAD) studied in combination with a standard sulphuric acid anodise and an alternating current-direct current phosphoric-sulphuric (ACDCPSAA) anodise in a benign electrolyte. It has been shown that the EPAD provides an open porous structure in order to enhance adhesion to the modified sulphuric acid anodised (SAA) surface. Additionally, a post anodising (PAD) treatment has been used to further aid structural adhesion in combination with the aforementioned processes. As a control, the standard 40/50V Bengough-Stuart chromic acid anodising (CAA) has been used as a baseline performance indicator in adhesion tests. Adhesion levels have been established using single lap shear and modified wedge test configurations. Overall, excellent initial joint strengths and durability have been found with both EPAD and ACDCPSAA, suggesting that these environmentally benign treatments may be used as possible drop-in replacements for the currently used CAA process