Reducing Adverse Impact While Maintaining Validity: Finding the Balance Between Competing Employee Selection Goals

Adverse (or disparate) impact has probably represented one of the most persistent and pervasive problems in employee selection. Innumerable approaches to eliminating its presence have been attempted, but most have been met with limited success. To date, this success has been measured in only slight reductions in adverse impact unless substantial losses in validity are accepted. While a number of reasons for these results have been advanced, this research asserted that part of the problem originated in the narrow perspective with which employee selection is often defined. This narrow perspective has resulted in a singular focus on validity with insufficient attention allocated to multiple criteria. The purpose of the present research was to expand upon an earlier study (Henderson & Ladd, 2001) that introduced a methodology (constrained estimation) that incorporated multiple objectives into the decision-making process associated with employee selection. Specifically, the goals of the methodology included reducing adverse impact while maintaining validity. In order to test the efficacy of this methodology, constrained estimation was applied to both Monte Carlo data as well as archival data obtained from an assessment project conducted from 1992 to 1993. It was also compared to two commonly used predictor weighting methodologies – Ordinary Least Squares regression and Unit Weighting. Results suggested that constrained estimation was moderately successful in reducing, but not eliminating, adverse impact while maintaining validity. Implications, limitations, and suggestions for future research are discussed

Influence of Histidine Residues, pH and Charge Interactions on Membrane-Spanning Peptides

Designed transmembrane peptides were employed for investigations of histidine residues within the hydrophobic environment of the lipid bilayer by means of oriented solid-state deuterium NMR spectroscopy. Using the model peptide GWALP23 sequence (GGALW(LA)6LWLAGA) as a host framework, the effects of single and double histidine mutations were explored. Replacement of leucine residue 12 to polar neutral histidine had little influence on the peptide average orientation, however under strongly acidic pH conditions in DOPC bilayers, the histidine becomes positively charged (pKa 2.5) and the GWALP23-H12 peptide exits the membrane and adopts a surface-bound orientation. Conversely, mutation of leucine 14 to neutral histidine altered tilt direction and magnitude of the peptide by a similar extent that that previously observed for neutral lysine at position 14. In DOPC bilayers, when histidine 14 becomes positively charged (pKa 4.1), the peptide remains in a well-defined transmembrane orientation with an increased tilt value compared to the neutral form. In DLPC bilayers, no pH dependent behavior was observed for either GWALP23-H12 or GWALP23-H14. Mutation of alanine at position 13 to histidine caused no change in peptide orientation in DOPC bilayers under neutral pH conditions. When the pH is lowered to 2, the spectra contain multiple weak resonances, indicative of multi-state behavior for the charged GWALP23-H13 peptide. A leucine to histidine mutation at position 16, located directly below Trp19, causes a large change in the azimuthal rotation of the peptide of \u3e100°. When the pH is lowered, histidine 16 becomes positively charged (pKa 3.5) and the tilt of the peptide increases. A peptide containing a pair of histidine residues at positions 12 and 13 displays behavior consistent with peptide oligmerization. The extent of this aggregation behavior appears to vary with pH, lipid composition, and macroscopic sample orientation. In DLPC bilayers, the presence of two histidine residues at positions 12 and 14 results in a decreased tilt value and a greater extent in helix unwinding. In DOPC bilayers, the GWALP23-H12,14 peptide orientation can not be explicitly identified. Additionally, unlike the single histidine peptides, the GWALP23-H12,14 does not display any pH-dependent behavior over a pH range of 2-7. Introducing a pair of histidine residues to positions 12 and 16 in DLPC bilayers results causes a change in helix tilt and rotation to allow both histidine residues access to the membrane interface. In DOPC bilayers, the GWALP23-H12,16 peptide adopts a surface-bound orientation which does not change with pH

The morphological, physiological, and genetic underpinnings of intraspecific salinity tolerance in Sorghum bicolor

Decreases in land quality and quantity threaten the efficient production of agriculturally and economically pivotal crops. Such reductions in arable lands are a consequence of population growth and urbanization, and often result in the introduction of various abiotic stresses. The most common abiotic stressors include water limitation (drought), water logging (over watering), poor water quality (salinity), and extreme temperatures (cold, frost, heat). Each of these stressors negatively impact plant growth, development, and yield. Soil salinity, specifically, is a considerable constraint affecting lands used in agriculture. Salts in the soil rise both naturally and through anthropogenic factors making the abundance a threat. Salt toxicity affects plants in two phases, the first of which is osmotic stress. Similar to drought stress, salinity imposed osmotic stress is when soil water potential is lower than the osmotic potential of the plant, therefore limiting water and nutrient extraction. Following osmotic stress, plants accumulate salt ions (e.g. Na+, Cl-, SO42-, NO3-) that can increase to toxic concentrations and disrupt normal metabolic processes. Such toxicity results in reduction of important traits such as root biomass, live aboveground biomass, height, and grain yield. The goals of my dissertation work involved dissecting the various morphological, physiological, and genetic underpinnings of salinity tolerance in Sorghum bicolor. Since research to date demonstrates a significant amount of underlying genetic variation, I designed various projects to investigate the genetic controls associated with phenotypic responses to salinity stress among a diverse group of Sorghum genotypes. In my first research chapter, I screened 21 sorghum accessions and interpreted tolerance as the ability to maintain biomass, similar to plants in control conditions, in response to a long-term treatment of 75 mM NaCl. Findings from this research chapter, when combined with published phylogenetic relationships, suggest that the greater salinity tolerance observed in some accessions of Sorghum bicolor, specifically in the landrace durra, are a byproduct of drought tolerance acquired during domestication. To further expand on these findings, I selected two accessions that showed significant variation in tolerance and used qPCR to investigate expression variation of genes associated with salt detoxification. During the secondary phase of salinity stress (referred to as ion toxicity) Na+ and Cl- ions enter the plant and disrupt normal metabolic processes. If the ions are not effectively managed, the primary evident effect is increased leaf senescence. Tolerant genotypes, however, are able to overcome ion toxicity if they can 1) continue production of new growth and 2) efficiently and effectively exclude, extrude, sequester, and transport ions. Results from this chapter indicate that the tolerant accession experienced an earlier onset of osmotic adjustment, promoting the efficient uptake and transport of water. Additionally, the sensitive accession experienced an earlier onset of ionic stress, suggesting poor exclusion at the root level. These findings suggest that the tolerant genotype has better control over osmotic adjustment and ion transport systems, therefore requiring fewer resources to be diverted for the stress response, providing more available energy that can be utilized for new growth and development. Finally, to further investigate the variation in genetic response to salt exposure, I evaluated the salinity tolerance that existed within a recombinant inbred line (RIL) population produced from a cross between Sorghum bicolor and Sorghum propinquum, two species that differ in response to salt exposure. In this study, I used a high-density genetic map to identify genetic markers correlated with salinity tolerance. I identified 146 candidate genes within the18 QTL intervals. QTL containing candidate genes that aid in the alleviation of osmotic stress (i.e. water acquisition, osmotic adjustment) were significantly associated with live aboveground biomass, and QTL containing candidate genes that aid in ionic detoxification (i.e. sensing, signaling, transporting) were significantly associated with an increase in dead aboveground biomass. Given the QTL and their associated phenotypes observed in the study, I suspect that the increased tolerance observed in S. bicolor is a result of early osmotic adjustment followed by effective sensing and signaling during the ionic phase of salinity response. In summary my dissertation work suggests that salinity stress in sorghum triggers a complex network of tightly regulated response elements, where the accumulation of ions, if properly transported and sequestered, aid in osmotic adjustment and ionic alleviation. Further, given Sorghum bicolor’s domestication history, it appears that increased salinity tolerance arose as a byproduct of the drought tolerance acquired during domestication, therefore aiding in an early osmotic adjustment and subsequent water acquisition

Pathogenesis of Lung Vasculitis

Vasculitides that affect the lung represent a diverse group of diseases with various systemic clinical manifestations, and include microscopic polyangiitis (MPA), granulomatosis with polyangiitis (GPA, formerly Wegener granulomatosis), Churg-Strauss syndrome (CSS), and anti-glomerular basement membrane (anti-GBM) disease (Goodpasture syndrome). The etiologies of these diseases remain largely unknown. Although the pathogenic mechanisms of each differ, these diseases overlap by the presence of anti-neutrophil cytoplasmic autoantibodies in the vast majority of patients with MPA and GPA, and a substantial minority of patients with CSS and anti-GBM disease. This article reviews the current understanding of the pathogenesis of these four disease entities

Determining the Impact of Increased Physical Activity on Improving Sleep Quality in Young Adults

Determining the Impact of Increased Physical Activity on Improving Sleep Quality in Young Adults Disturbed sleep, defined as any alteration to normal sleep patterns, has been linked to poor cardiovascular health and an increase in cardiovascular disease (CVD) risk. These negative sleep patterns are highly prevalent with 35% to 41% of individuals in the United States reported some form of disturbed sleep. Although high amounts of physical activity (PA) are often associated with high sleep quality, little is known about PA’s effectiveness to improve different aspects of sleep (e.g. duration vs quality) and the mechanisms to which it can improve sleep quality. Purpose: The study sought to determine the ability of increased PA to improve sleep efficiency in healthy young adults. Methods: Nineteen young adults (25±4 yrs) were recruited for this study. Subjects wore an accelerometer (Actigraph GT3x-BT) for a total of three weeks to record daily physical activity (step count; low, moderate, and vigorous physical activity) and sleep variables (efficiency, wake after sleep onset, number of nightly awakenings, time per awakening, and total sleep time). Subjects maintained normal physical activity levels for the first week (BL), then increased their step count by an average of 5,000 steps/day across the next two weeks (W1 and W2). Heart rate variability (HRV) and venous blood draws were collected weekly to assess sympathetic activity and inflammation, respectively. Results: The physical activity intervention resulted in significant increases (p \u3c 0.001) in step-count for both W1 (13163 ± 3184) and W2 (12168 ± 3619) when compared to BL (8648 ± 2615 steps/day). No significant differences from BL were observed when examining sleep efficiency (BL: 83.8 ± 6.4; W1: 85.5 ± 4.0; W2: 84.2 ± 6.1 %), sympathetic-vagal balance, and inflammatory marker concentrations in W1 and W2. A significant correlation was revealed when assessing the change in sleep efficiency from BL to W1 (r = 0.81, p \u3c 0.001) and BL to W2 (r = 0.52, p = 0.02) when compared to initial sleep efficiency values. Conclusion: This study revealed that although young healthy individuals appear to lack improvements in sleep efficiency with an increase in physical activity, those who reported the lowest sleep quality had the greatest improvements in sleep efficiency following an increase in physical activity. Therefore, the findings of the study suggest that although increasing physical activity can improve sleep quality, a potential “ceiling effect” may occur, as when sleep quality is adequate, augmenting physical activity no longer has a substantial effect.https://scholarscompass.vcu.edu/gradposters/1058/thumbnail.jp

Tracking The Field: Volume 5 - Analyzing Trends In Environmental Grantmaking

This report builds on the Environmental Grantmakers Association's (EGA) grant research from 2007 to 2013, deepening our understanding of trends and gaps in environmental philanthropy.Analyzing grant data from the supply side of funding within the environment movement, the Tracking the Field report provides an avenue for EGA members to see where their grantmaking fits into the larger environmental movement and how they can optimize their grant dollars to be more strategic and effective.Tracking the Field: Volume 5 analyzes 66,340 grants, totaling more than $6.8 billion between 2007 and 2013. With six grant years of data, we are able to see the impact of outside influences on environmental philanthropy in addition to shifts within the field

Hydrator Therapies for Chronic Bronchitis. Lessons from Cystic Fibrosis

Patients with the chronic bronchitis form of chronic obstructive pulmonary disease and cystic fibrosis share similar clinical features, including mucus obstruction of airways and the development of chronic/recurrent airways infections that often manifest as disease exacerbations. There is growing evidence that these diseases may have parallels in disease pathogenesis as well, including cystic fibrosis transmembrane conductance regulator dysfunction, mucus dehydration, and defective mucociliary clearance. As progress is made in the development of therapies that target the basic defects that lead to cystic fibrosis lung disease, it is possible that similar approaches could also benefit patients with chronic bronchitis. A deeper understanding of how tobacco smoke and other triggers of chronic bronchitis actually lead to disease, and exploration of the concept that therapies that restore cystic fibrosis transmembrane conductance regulator function, mucus hydration, and/or mucociliary clearance may benefit patients with chronic bronchitis, hold the prospect of significant progress in treating this prevalent disease

Utilizing pHluorin-Tagged Receptors to Monitor Subcellular Localization and Trafficking

Understanding membrane protein trafficking, assembly, and expression requires an approach that differentiates between those residing in intracellular organelles and those localized on the plasma membrane. Traditional fluorescence-based measurements lack the capability to distinguish membrane proteins residing in different organelles. Cutting edge methodologies transcend traditional methods by coupling pH-sensitive fluorophores with total internal reflection fluorescence microscopy (TIRFM). TIRF illumination excites the sample up to approximately 150 nm from the glass-sample interface, thus decreasing background, increasing the signal to noise ratio, and enhancing resolution. The excitation volume in TIRFM encompasses the plasma membrane and nearby organelles such as the peripheral ER. Superecliptic pHluorin (SEP) is a pH sensitive version of GFP. Genetically encoding SEP into the extracellular domain of a membrane protein of interest positions the fluorophore on the luminal side of the ER and in the extracellular region of the cell. SEP is fluorescent when the pH is greater than 6, but remains in an off state at lower pH values. Therefore, receptors tagged with SEP fluoresce when residing in the endoplasmic reticulum (ER) or upon insertion in the plasma membrane (PM) but not when confined to a trafficking vesicle or other organelles such as the Golgi. The extracellular pH can be adjusted to dictate the fluorescence of receptors on the plasma membrane. The difference in fluorescence between TIRF images at neutral and acidic extracellular pH for the same cell corresponds to a relative number of receptors on the plasma membrane. This allows a simultaneous measurement of intracellular and plasma membrane resident receptors. Single vesicle insertion events can also be measured when the extracellular pH is neutral, corresponding to a low pH trafficking vesicle fusing with the plasma membrane and transitioning into a fluorescent state. This versatile technique can be exploited to study localization, expression, and trafficking of membrane proteins

Touch decisions: For heritage objects

Conservators have a complex relationship with touching things. As the conservation profession looks to the future, conservators need to be, and be seen to be, co-creators of considered access rather than gatekeepers to collections. The benefits of touch can be physical and tangible, but touch can also inform our emotions, support empathy, or provide a connection. Touch can be used to understand how something moves or to learn how to manipulate things. This paper reviews conservation’s engagement with touch, attempting to extract a more nuanced understanding of the values that can be achieved through touching defined by context. By examining issues surrounding who conservation is for, the nature of touch and how conservators discuss it, this paper invites the profession to be more systematic about enabling touch experiences whilst managing these effectively with our conservation responsibilities

Analysis of World War One Diaries using Natural Language Processing

World War I was a significant event in Australian history and as such it has been extensively researched. The analysis of relevant primary sources has included the close reading of war diaries. Close reading involves reading the diaries to understand what the soldiers went through. With the advancement of computational techniques, we now have the ability to analyse large volumes of text, and this concept is known as distant reading. This project focuses on 557 Australian World War I diaries collected and transcribed by the State Library of New South Wales, and aims to use distant reading methods to determine what the soldiers wrote about and how they felt over the course of the war. In order to perform our analysis over time, we first needed to extract dates from the diaries. This was done using regular expressions. However, some problems were found in the extracted dates, including missing data such as the month or year, dates which were written incorrectly, and dates that were actually within the text referring to events that happened rather than the date the diaries were written. Hence, an optimisation program was formed to fix these problems and give more accurate information about when the diaries were written. We then considered several types of analysis to understand what the soldiers wrote about, including word frequencies, tf-idf (term frequency - inverse document frequency), and topic modelling. It was found that whilst all three of these techniques gave results that would be expected when considering World War I diaries, they also showed different aspects of the war. In particular, through considering the tf-idf results for 1916 we see many words regarding places and battles in the Middle East. However, when considering topic modelling for this time period we see more words regarding Europe. Sentiment analysis, more specifically dictionary-based methods, was then used to understand the emotions of the soldiers over time. Using our dictionaries, each month was given an overall sentiment score from -1 (very negative) to +1 (very positive). It was found that the average sentiment of the diaries ranged between 0 and 0.2. We were also able to compare this to our topic modelling results to determine which topics corresponded to peaks and dips in our sentiment.Thesis (MPhil) -- University of Adelaide, School of Mathematical Sciences, 202